summaryrefslogtreecommitdiff
path: root/net/sctp/sm_statefuns.c
blob: cc544a97c4afd796c289783c469295e7618f397e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
// SPDX-License-Identifier: GPL-2.0-or-later
/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2002 Intel Corp.
 * Copyright (c) 2002      Nokia Corp.
 *
 * This is part of the SCTP Linux Kernel Implementation.
 *
 * These are the state functions for the state machine.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Mathew Kotowsky       <kotowsky@sctp.org>
 *    Sridhar Samudrala     <samudrala@us.ibm.com>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Hui Huang 	    <hui.huang@nokia.com>
 *    Dajiang Zhang 	    <dajiang.zhang@nokia.com>
 *    Daisy Chang	    <daisyc@us.ibm.com>
 *    Ardelle Fan	    <ardelle.fan@intel.com>
 *    Ryan Layer	    <rmlayer@us.ibm.com>
 *    Kevin Gao		    <kevin.gao@intel.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/inet_ecn.h>
#include <linux/skbuff.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <net/sctp/structs.h>

#define CREATE_TRACE_POINTS
#include <trace/events/sctp.h>

static struct sctp_packet *sctp_abort_pkt_new(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk,
					const void *payload, size_t paylen);
static int sctp_eat_data(const struct sctp_association *asoc,
			 struct sctp_chunk *chunk,
			 struct sctp_cmd_seq *commands);
static struct sctp_packet *sctp_ootb_pkt_new(
					struct net *net,
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk);
static void sctp_send_stale_cookie_err(struct net *net,
				       const struct sctp_endpoint *ep,
				       const struct sctp_association *asoc,
				       const struct sctp_chunk *chunk,
				       struct sctp_cmd_seq *commands,
				       struct sctp_chunk *err_chunk);
static enum sctp_disposition sctp_sf_do_5_2_6_stale(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);
static enum sctp_disposition sctp_sf_shut_8_4_5(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);
static enum sctp_disposition sctp_sf_tabort_8_4_8(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);
static enum sctp_disposition sctp_sf_new_encap_port(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);
static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);

static enum sctp_disposition sctp_stop_t1_and_abort(
					struct net *net,
					struct sctp_cmd_seq *commands,
					__be16 error, int sk_err,
					const struct sctp_association *asoc,
					struct sctp_transport *transport);

static enum sctp_disposition sctp_sf_abort_violation(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					void *arg,
					struct sctp_cmd_seq *commands,
					const __u8 *payload,
					const size_t paylen);

static enum sctp_disposition sctp_sf_violation_chunklen(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);

static enum sctp_disposition sctp_sf_violation_paramlen(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg, void *ext,
					struct sctp_cmd_seq *commands);

static enum sctp_disposition sctp_sf_violation_ctsn(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);

static enum sctp_disposition sctp_sf_violation_chunk(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);

static enum sctp_ierror sctp_sf_authenticate(
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk);

static enum sctp_disposition __sctp_sf_do_9_1_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands);

static enum sctp_disposition
__sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
			   const struct sctp_association *asoc,
			   const union sctp_subtype type, void *arg,
			   struct sctp_cmd_seq *commands);

/* Small helper function that checks if the chunk length
 * is of the appropriate length.  The 'required_length' argument
 * is set to be the size of a specific chunk we are testing.
 * Return Values:  true  = Valid length
 * 		   false = Invalid length
 *
 */
static inline bool sctp_chunk_length_valid(struct sctp_chunk *chunk,
					   __u16 required_length)
{
	__u16 chunk_length = ntohs(chunk->chunk_hdr->length);

	/* Previously already marked? */
	if (unlikely(chunk->pdiscard))
		return false;
	if (unlikely(chunk_length < required_length))
		return false;

	return true;
}

/* Check for format error in an ABORT chunk */
static inline bool sctp_err_chunk_valid(struct sctp_chunk *chunk)
{
	struct sctp_errhdr *err;

	sctp_walk_errors(err, chunk->chunk_hdr);

	return (void *)err == (void *)chunk->chunk_end;
}

/**********************************************************
 * These are the state functions for handling chunk events.
 **********************************************************/

/*
 * Process the final SHUTDOWN COMPLETE.
 *
 * Section: 4 (C) (diagram), 9.2
 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
 * should stop the T2-shutdown timer and remove all knowledge of the
 * association (and thus the association enters the CLOSED state).
 *
 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
 * C) Rules for packet carrying SHUTDOWN COMPLETE:
 * ...
 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
 *   if the Verification Tag field of the packet matches its own tag and
 *   the T bit is not set
 *   OR
 *   it is set to its peer's tag and the T bit is set in the Chunk
 *   Flags.
 *   Otherwise, the receiver MUST silently discard the packet
 *   and take no further action.  An endpoint MUST ignore the
 *   SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_4_C(struct net *net,
				     const struct sctp_endpoint *ep,
				     const struct sctp_association *asoc,
				     const union sctp_subtype type,
				     void *arg, struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_ulpevent *ev;

	if (!sctp_vtag_verify_either(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* RFC 2960 6.10 Bundling
	 *
	 * An endpoint MUST NOT bundle INIT, INIT ACK or
	 * SHUTDOWN COMPLETE with any other chunks.
	 */
	if (!chunk->singleton)
		return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);

	/* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* RFC 2960 10.2 SCTP-to-ULP
	 *
	 * H) SHUTDOWN COMPLETE notification
	 *
	 * When SCTP completes the shutdown procedures (section 9.2) this
	 * notification is passed to the upper layer.
	 */
	ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
					     0, 0, 0, NULL, GFP_ATOMIC);
	if (ev)
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(ev));

	/* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
	 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
	 * not the chunk should be discarded. If the endpoint is in
	 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
	 * T2-shutdown timer and remove all knowledge of the
	 * association (and thus the association enters the CLOSED
	 * state).
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_CLOSED));

	SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);

	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());

	return SCTP_DISPOSITION_DELETE_TCB;
}

/*
 * Respond to a normal INIT chunk.
 * We are the side that is being asked for an association.
 *
 * Section: 5.1 Normal Establishment of an Association, B
 * B) "Z" shall respond immediately with an INIT ACK chunk.  The
 *    destination IP address of the INIT ACK MUST be set to the source
 *    IP address of the INIT to which this INIT ACK is responding.  In
 *    the response, besides filling in other parameters, "Z" must set the
 *    Verification Tag field to Tag_A, and also provide its own
 *    Verification Tag (Tag_Z) in the Initiate Tag field.
 *
 * Verification Tag: Must be 0.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg, *repl, *err_chunk;
	struct sctp_unrecognized_param *unk_param;
	struct sctp_association *new_asoc;
	struct sctp_packet *packet;
	int len;

	/* 6.10 Bundling
	 * An endpoint MUST NOT bundle INIT, INIT ACK or
	 * SHUTDOWN COMPLETE with any other chunks.
	 *
	 * IG Section 2.11.2
	 * Furthermore, we require that the receiver of an INIT chunk MUST
	 * enforce these rules by silently discarding an arriving packet
	 * with an INIT chunk that is bundled with other chunks.
	 */
	if (!chunk->singleton)
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the INIT chunk has a valid length.
	 * Normally, this would cause an ABORT with a Protocol Violation
	 * error, but since we don't have an association, we'll
	 * just discard the packet.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* If the packet is an OOTB packet which is temporarily on the
	 * control endpoint, respond with an ABORT.
	 */
	if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
		SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
	}

	/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
	 * Tag.
	 */
	if (chunk->sctp_hdr->vtag != 0)
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);

	/* If the INIT is coming toward a closing socket, we'll send back
	 * and ABORT.  Essentially, this catches the race of INIT being
	 * backloged to the socket at the same time as the user issues close().
	 * Since the socket and all its associations are going away, we
	 * can treat this OOTB
	 */
	if (sctp_sstate(ep->base.sk, CLOSING))
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);

	/* Verify the INIT chunk before processing it. */
	err_chunk = NULL;
	if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
			      (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
			      &err_chunk)) {
		/* This chunk contains fatal error. It is to be discarded.
		 * Send an ABORT, with causes if there is any.
		 */
		if (err_chunk) {
			packet = sctp_abort_pkt_new(net, ep, asoc, arg,
					(__u8 *)(err_chunk->chunk_hdr) +
					sizeof(struct sctp_chunkhdr),
					ntohs(err_chunk->chunk_hdr->length) -
					sizeof(struct sctp_chunkhdr));

			sctp_chunk_free(err_chunk);

			if (packet) {
				sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
						SCTP_PACKET(packet));
				SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
				return SCTP_DISPOSITION_CONSUME;
			} else {
				return SCTP_DISPOSITION_NOMEM;
			}
		} else {
			return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
						    commands);
		}
	}

	/* Grab the INIT header.  */
	chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;

	/* Tag the variable length parameters.  */
	chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));

	new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
	if (!new_asoc)
		goto nomem;

	/* Update socket peer label if first association. */
	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
		sctp_association_free(new_asoc);
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
					     sctp_scope(sctp_source(chunk)),
					     GFP_ATOMIC) < 0)
		goto nomem_init;

	/* The call, sctp_process_init(), can fail on memory allocation.  */
	if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
			       (struct sctp_init_chunk *)chunk->chunk_hdr,
			       GFP_ATOMIC))
		goto nomem_init;

	/* B) "Z" shall respond immediately with an INIT ACK chunk.  */

	/* If there are errors need to be reported for unknown parameters,
	 * make sure to reserve enough room in the INIT ACK for them.
	 */
	len = 0;
	if (err_chunk)
		len = ntohs(err_chunk->chunk_hdr->length) -
		      sizeof(struct sctp_chunkhdr);

	repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
	if (!repl)
		goto nomem_init;

	/* If there are errors need to be reported for unknown parameters,
	 * include them in the outgoing INIT ACK as "Unrecognized parameter"
	 * parameter.
	 */
	if (err_chunk) {
		/* Get the "Unrecognized parameter" parameter(s) out of the
		 * ERROR chunk generated by sctp_verify_init(). Since the
		 * error cause code for "unknown parameter" and the
		 * "Unrecognized parameter" type is the same, we can
		 * construct the parameters in INIT ACK by copying the
		 * ERROR causes over.
		 */
		unk_param = (struct sctp_unrecognized_param *)
			    ((__u8 *)(err_chunk->chunk_hdr) +
			    sizeof(struct sctp_chunkhdr));
		/* Replace the cause code with the "Unrecognized parameter"
		 * parameter type.
		 */
		sctp_addto_chunk(repl, len, unk_param);
		sctp_chunk_free(err_chunk);
	}

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));

	/*
	 * Note:  After sending out INIT ACK with the State Cookie parameter,
	 * "Z" MUST NOT allocate any resources, nor keep any states for the
	 * new association.  Otherwise, "Z" will be vulnerable to resource
	 * attacks.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());

	return SCTP_DISPOSITION_DELETE_TCB;

nomem_init:
	sctp_association_free(new_asoc);
nomem:
	if (err_chunk)
		sctp_chunk_free(err_chunk);
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Respond to a normal INIT ACK chunk.
 * We are the side that is initiating the association.
 *
 * Section: 5.1 Normal Establishment of an Association, C
 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
 *    timer and leave COOKIE-WAIT state. "A" shall then send the State
 *    Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
 *    the T1-cookie timer, and enter the COOKIE-ECHOED state.
 *
 *    Note: The COOKIE ECHO chunk can be bundled with any pending outbound
 *    DATA chunks, but it MUST be the first chunk in the packet and
 *    until the COOKIE ACK is returned the sender MUST NOT send any
 *    other packets to the peer.
 *
 * Verification Tag: 3.3.3
 *   If the value of the Initiate Tag in a received INIT ACK chunk is
 *   found to be 0, the receiver MUST treat it as an error and close the
 *   association by transmitting an ABORT.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_1C_ack(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  const union sctp_subtype type,
					  void *arg,
					  struct sctp_cmd_seq *commands)
{
	struct sctp_init_chunk *initchunk;
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *err_chunk;
	struct sctp_packet *packet;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* 6.10 Bundling
	 * An endpoint MUST NOT bundle INIT, INIT ACK or
	 * SHUTDOWN COMPLETE with any other chunks.
	 */
	if (!chunk->singleton)
		return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);

	/* Make sure that the INIT-ACK chunk has a valid length */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_initack_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);
	/* Grab the INIT header.  */
	chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;

	/* Verify the INIT chunk before processing it. */
	err_chunk = NULL;
	if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
			      (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
			      &err_chunk)) {

		enum sctp_error error = SCTP_ERROR_NO_RESOURCE;

		/* This chunk contains fatal error. It is to be discarded.
		 * Send an ABORT, with causes.  If there are no causes,
		 * then there wasn't enough memory.  Just terminate
		 * the association.
		 */
		if (err_chunk) {
			packet = sctp_abort_pkt_new(net, ep, asoc, arg,
					(__u8 *)(err_chunk->chunk_hdr) +
					sizeof(struct sctp_chunkhdr),
					ntohs(err_chunk->chunk_hdr->length) -
					sizeof(struct sctp_chunkhdr));

			sctp_chunk_free(err_chunk);

			if (packet) {
				sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
						SCTP_PACKET(packet));
				SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
				error = SCTP_ERROR_INV_PARAM;
			}
		}

		/* SCTP-AUTH, Section 6.3:
		 *    It should be noted that if the receiver wants to tear
		 *    down an association in an authenticated way only, the
		 *    handling of malformed packets should not result in
		 *    tearing down the association.
		 *
		 * This means that if we only want to abort associations
		 * in an authenticated way (i.e AUTH+ABORT), then we
		 * can't destroy this association just because the packet
		 * was malformed.
		 */
		if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
			return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
						asoc, chunk->transport);
	}

	/* Tag the variable length parameters.  Note that we never
	 * convert the parameters in an INIT chunk.
	 */
	chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));

	initchunk = (struct sctp_init_chunk *)chunk->chunk_hdr;

	sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
			SCTP_PEER_INIT(initchunk));

	/* Reset init error count upon receipt of INIT-ACK.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());

	/* 5.1 C) "A" shall stop the T1-init timer and leave
	 * COOKIE-WAIT state.  "A" shall then ... start the T1-cookie
	 * timer, and enter the COOKIE-ECHOED state.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));

	/* SCTP-AUTH: generate the association shared keys so that
	 * we can potentially sign the COOKIE-ECHO.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());

	/* 5.1 C) "A" shall then send the State Cookie received in the
	 * INIT ACK chunk in a COOKIE ECHO chunk, ...
	 */
	/* If there is any errors to report, send the ERROR chunk generated
	 * for unknown parameters as well.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
			SCTP_CHUNK(err_chunk));

	return SCTP_DISPOSITION_CONSUME;
}

static bool sctp_auth_chunk_verify(struct net *net, struct sctp_chunk *chunk,
				   const struct sctp_association *asoc)
{
	struct sctp_chunk auth;

	if (!chunk->auth_chunk)
		return true;

	/* SCTP-AUTH:  auth_chunk pointer is only set when the cookie-echo
	 * is supposed to be authenticated and we have to do delayed
	 * authentication.  We've just recreated the association using
	 * the information in the cookie and now it's much easier to
	 * do the authentication.
	 */

	/* Make sure that we and the peer are AUTH capable */
	if (!net->sctp.auth_enable || !asoc->peer.auth_capable)
		return false;

	/* set-up our fake chunk so that we can process it */
	auth.skb = chunk->auth_chunk;
	auth.asoc = chunk->asoc;
	auth.sctp_hdr = chunk->sctp_hdr;
	auth.chunk_hdr = (struct sctp_chunkhdr *)
				skb_push(chunk->auth_chunk,
					 sizeof(struct sctp_chunkhdr));
	skb_pull(chunk->auth_chunk, sizeof(struct sctp_chunkhdr));
	auth.transport = chunk->transport;

	return sctp_sf_authenticate(asoc, &auth) == SCTP_IERROR_NO_ERROR;
}

/*
 * Respond to a normal COOKIE ECHO chunk.
 * We are the side that is being asked for an association.
 *
 * Section: 5.1 Normal Establishment of an Association, D
 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
 *    with a COOKIE ACK chunk after building a TCB and moving to
 *    the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
 *    any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
 *    chunk MUST be the first chunk in the packet.
 *
 *   IMPLEMENTATION NOTE: An implementation may choose to send the
 *   Communication Up notification to the SCTP user upon reception
 *   of a valid COOKIE ECHO chunk.
 *
 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
 * D) Rules for packet carrying a COOKIE ECHO
 *
 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
 *   Initial Tag received in the INIT ACK.
 *
 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
					 const struct sctp_endpoint *ep,
					 const struct sctp_association *asoc,
					 const union sctp_subtype type,
					 void *arg,
					 struct sctp_cmd_seq *commands)
{
	struct sctp_ulpevent *ev, *ai_ev = NULL, *auth_ev = NULL;
	struct sctp_association *new_asoc;
	struct sctp_init_chunk *peer_init;
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *err_chk_p;
	struct sctp_chunk *repl;
	struct sock *sk;
	int error = 0;

	if (asoc && !sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* If the packet is an OOTB packet which is temporarily on the
	 * control endpoint, respond with an ABORT.
	 */
	if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
		SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
	}

	/* Make sure that the COOKIE_ECHO chunk has a valid length.
	 * In this case, we check that we have enough for at least a
	 * chunk header.  More detailed verification is done
	 * in sctp_unpack_cookie().
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* If the endpoint is not listening or if the number of associations
	 * on the TCP-style socket exceed the max backlog, respond with an
	 * ABORT.
	 */
	sk = ep->base.sk;
	if (!sctp_sstate(sk, LISTENING) ||
	    (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);

	/* "Decode" the chunk.  We have no optional parameters so we
	 * are in good shape.
	 */
	chunk->subh.cookie_hdr =
		(struct sctp_signed_cookie *)chunk->skb->data;
	if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
					 sizeof(struct sctp_chunkhdr)))
		goto nomem;

	/* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
	 * "Z" will reply with a COOKIE ACK chunk after building a TCB
	 * and moving to the ESTABLISHED state.
	 */
	new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
				      &err_chk_p);

	/* FIXME:
	 * If the re-build failed, what is the proper error path
	 * from here?
	 *
	 * [We should abort the association. --piggy]
	 */
	if (!new_asoc) {
		/* FIXME: Several errors are possible.  A bad cookie should
		 * be silently discarded, but think about logging it too.
		 */
		switch (error) {
		case -SCTP_IERROR_NOMEM:
			goto nomem;

		case -SCTP_IERROR_STALE_COOKIE:
			sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
						   err_chk_p);
			return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

		case -SCTP_IERROR_BAD_SIG:
		default:
			return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
		}
	}

	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
		sctp_association_free(new_asoc);
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	/* Delay state machine commands until later.
	 *
	 * Re-build the bind address for the association is done in
	 * the sctp_unpack_cookie() already.
	 */
	/* This is a brand-new association, so these are not yet side
	 * effects--it is safe to run them here.
	 */
	peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];

	if (!sctp_process_init(new_asoc, chunk,
			       &chunk->subh.cookie_hdr->c.peer_addr,
			       peer_init, GFP_ATOMIC))
		goto nomem_init;

	/* SCTP-AUTH:  Now that we've populate required fields in
	 * sctp_process_init, set up the association shared keys as
	 * necessary so that we can potentially authenticate the ACK
	 */
	error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
	if (error)
		goto nomem_init;

	if (!sctp_auth_chunk_verify(net, chunk, new_asoc)) {
		sctp_association_free(new_asoc);
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	repl = sctp_make_cookie_ack(new_asoc, chunk);
	if (!repl)
		goto nomem_init;

	/* RFC 2960 5.1 Normal Establishment of an Association
	 *
	 * D) IMPLEMENTATION NOTE: An implementation may choose to
	 * send the Communication Up notification to the SCTP user
	 * upon reception of a valid COOKIE ECHO chunk.
	 */
	ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
					     new_asoc->c.sinit_num_ostreams,
					     new_asoc->c.sinit_max_instreams,
					     NULL, GFP_ATOMIC);
	if (!ev)
		goto nomem_ev;

	/* Sockets API Draft Section 5.3.1.6
	 * When a peer sends a Adaptation Layer Indication parameter , SCTP
	 * delivers this notification to inform the application that of the
	 * peers requested adaptation layer.
	 */
	if (new_asoc->peer.adaptation_ind) {
		ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
							    GFP_ATOMIC);
		if (!ai_ev)
			goto nomem_aiev;
	}

	if (!new_asoc->peer.auth_capable) {
		auth_ev = sctp_ulpevent_make_authkey(new_asoc, 0,
						     SCTP_AUTH_NO_AUTH,
						     GFP_ATOMIC);
		if (!auth_ev)
			goto nomem_authev;
	}

	/* Add all the state machine commands now since we've created
	 * everything.  This way we don't introduce memory corruptions
	 * during side-effect processing and correctly count established
	 * associations.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_ESTABLISHED));
	SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
	SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());

	if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));

	/* This will send the COOKIE ACK */
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));

	/* Queue the ASSOC_CHANGE event */
	sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));

	/* Send up the Adaptation Layer Indication event */
	if (ai_ev)
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(ai_ev));

	if (auth_ev)
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(auth_ev));

	return SCTP_DISPOSITION_CONSUME;

nomem_authev:
	sctp_ulpevent_free(ai_ev);
nomem_aiev:
	sctp_ulpevent_free(ev);
nomem_ev:
	sctp_chunk_free(repl);
nomem_init:
	sctp_association_free(new_asoc);
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Respond to a normal COOKIE ACK chunk.
 * We are the side that is asking for an association.
 *
 * RFC 2960 5.1 Normal Establishment of an Association
 *
 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
 *    COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
 *    timer. It may also notify its ULP about the successful
 *    establishment of the association with a Communication Up
 *    notification (see Section 10).
 *
 * Verification Tag:
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net,
					 const struct sctp_endpoint *ep,
					 const struct sctp_association *asoc,
					 const union sctp_subtype type,
					 void *arg,
					 struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_ulpevent *ev;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Verify that the chunk length for the COOKIE-ACK is OK.
	 * If we don't do this, any bundled chunks may be junked.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* Reset init error count upon receipt of COOKIE-ACK,
	 * to avoid problems with the management of this
	 * counter in stale cookie situations when a transition back
	 * from the COOKIE-ECHOED state to the COOKIE-WAIT
	 * state is performed.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());

	/* Set peer label for connection. */
	security_inet_conn_established(ep->base.sk, chunk->skb);

	/* RFC 2960 5.1 Normal Establishment of an Association
	 *
	 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
	 * from the COOKIE-ECHOED state to the ESTABLISHED state,
	 * stopping the T1-cookie timer.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_ESTABLISHED));
	SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
	SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
	if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));

	/* It may also notify its ULP about the successful
	 * establishment of the association with a Communication Up
	 * notification (see Section 10).
	 */
	ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
					     0, asoc->c.sinit_num_ostreams,
					     asoc->c.sinit_max_instreams,
					     NULL, GFP_ATOMIC);

	if (!ev)
		goto nomem;

	sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));

	/* Sockets API Draft Section 5.3.1.6
	 * When a peer sends a Adaptation Layer Indication parameter , SCTP
	 * delivers this notification to inform the application that of the
	 * peers requested adaptation layer.
	 */
	if (asoc->peer.adaptation_ind) {
		ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
		if (!ev)
			goto nomem;

		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(ev));
	}

	if (!asoc->peer.auth_capable) {
		ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH,
						GFP_ATOMIC);
		if (!ev)
			goto nomem;
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(ev));
	}

	return SCTP_DISPOSITION_CONSUME;
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/* Generate and sendout a heartbeat packet.  */
static enum sctp_disposition sctp_sf_heartbeat(
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_transport *transport = (struct sctp_transport *) arg;
	struct sctp_chunk *reply;

	/* Send a heartbeat to our peer.  */
	reply = sctp_make_heartbeat(asoc, transport, 0);
	if (!reply)
		return SCTP_DISPOSITION_NOMEM;

	/* Set rto_pending indicating that an RTT measurement
	 * is started with this heartbeat chunk.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
			SCTP_TRANSPORT(transport));

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
	return SCTP_DISPOSITION_CONSUME;
}

/* Generate a HEARTBEAT packet on the given transport.  */
enum sctp_disposition sctp_sf_sendbeat_8_3(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_transport *transport = (struct sctp_transport *) arg;

	if (asoc->overall_error_count >= asoc->max_retrans) {
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_ERROR));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_DISPOSITION_DELETE_TCB;
	}

	/* Section 3.3.5.
	 * The Sender-specific Heartbeat Info field should normally include
	 * information about the sender's current time when this HEARTBEAT
	 * chunk is sent and the destination transport address to which this
	 * HEARTBEAT is sent (see Section 8.3).
	 */

	if (transport->param_flags & SPP_HB_ENABLE) {
		if (SCTP_DISPOSITION_NOMEM ==
				sctp_sf_heartbeat(ep, asoc, type, arg,
						  commands))
			return SCTP_DISPOSITION_NOMEM;

		/* Set transport error counter and association error counter
		 * when sending heartbeat.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
				SCTP_TRANSPORT(transport));
	}
	sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
			SCTP_TRANSPORT(transport));
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
			SCTP_TRANSPORT(transport));

	return SCTP_DISPOSITION_CONSUME;
}

/* resend asoc strreset_chunk.  */
enum sctp_disposition sctp_sf_send_reconf(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  const union sctp_subtype type,
					  void *arg,
					  struct sctp_cmd_seq *commands)
{
	struct sctp_transport *transport = arg;

	if (asoc->overall_error_count >= asoc->max_retrans) {
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_ERROR));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_DISPOSITION_DELETE_TCB;
	}

	sctp_chunk_hold(asoc->strreset_chunk);
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
			SCTP_CHUNK(asoc->strreset_chunk));
	sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));

	return SCTP_DISPOSITION_CONSUME;
}

/* send hb chunk with padding for PLPMUTD.  */
enum sctp_disposition sctp_sf_send_probe(struct net *net,
					 const struct sctp_endpoint *ep,
					 const struct sctp_association *asoc,
					 const union sctp_subtype type,
					 void *arg,
					 struct sctp_cmd_seq *commands)
{
	struct sctp_transport *transport = (struct sctp_transport *)arg;
	struct sctp_chunk *reply;

	if (!sctp_transport_pl_enabled(transport))
		return SCTP_DISPOSITION_CONSUME;

	sctp_transport_pl_send(transport);
	reply = sctp_make_heartbeat(asoc, transport, transport->pl.probe_size);
	if (!reply)
		return SCTP_DISPOSITION_NOMEM;
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
	sctp_add_cmd_sf(commands, SCTP_CMD_PROBE_TIMER_UPDATE,
			SCTP_TRANSPORT(transport));

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Process an heartbeat request.
 *
 * Section: 8.3 Path Heartbeat
 * The receiver of the HEARTBEAT should immediately respond with a
 * HEARTBEAT ACK that contains the Heartbeat Information field copied
 * from the received HEARTBEAT chunk.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 * When receiving an SCTP packet, the endpoint MUST ensure that the
 * value in the Verification Tag field of the received SCTP packet
 * matches its own Tag. If the received Verification Tag value does not
 * match the receiver's own tag value, the receiver shall silently
 * discard the packet and shall not process it any further except for
 * those cases listed in Section 8.5.1 below.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_beat_8_3(struct net *net,
				       const struct sctp_endpoint *ep,
				       const struct sctp_association *asoc,
				       const union sctp_subtype type,
				       void *arg, struct sctp_cmd_seq *commands)
{
	struct sctp_paramhdr *param_hdr;
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *reply;
	size_t paylen = 0;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the HEARTBEAT chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk,
				     sizeof(struct sctp_heartbeat_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* 8.3 The receiver of the HEARTBEAT should immediately
	 * respond with a HEARTBEAT ACK that contains the Heartbeat
	 * Information field copied from the received HEARTBEAT chunk.
	 */
	chunk->subh.hb_hdr = (struct sctp_heartbeathdr *)chunk->skb->data;
	param_hdr = (struct sctp_paramhdr *)chunk->subh.hb_hdr;
	paylen = ntohs(chunk->chunk_hdr->length) - sizeof(struct sctp_chunkhdr);

	if (ntohs(param_hdr->length) > paylen)
		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
						  param_hdr, commands);

	if (!pskb_pull(chunk->skb, paylen))
		goto nomem;

	reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
	if (!reply)
		goto nomem;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Process the returning HEARTBEAT ACK.
 *
 * Section: 8.3 Path Heartbeat
 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
 * should clear the error counter of the destination transport
 * address to which the HEARTBEAT was sent, and mark the destination
 * transport address as active if it is not so marked. The endpoint may
 * optionally report to the upper layer when an inactive destination
 * address is marked as active due to the reception of the latest
 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
 * clear the association overall error count as well (as defined
 * in section 8.1).
 *
 * The receiver of the HEARTBEAT ACK should also perform an RTT
 * measurement for that destination transport address using the time
 * value carried in the HEARTBEAT ACK chunk.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_backbeat_8_3(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_sender_hb_info *hbinfo;
	struct sctp_chunk *chunk = arg;
	struct sctp_transport *link;
	unsigned long max_interval;
	union sctp_addr from_addr;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the HEARTBEAT-ACK chunk has a valid length.  */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr) +
					    sizeof(*hbinfo)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
	/* Make sure that the length of the parameter is what we expect */
	if (ntohs(hbinfo->param_hdr.length) != sizeof(*hbinfo))
		return SCTP_DISPOSITION_DISCARD;

	from_addr = hbinfo->daddr;
	link = sctp_assoc_lookup_paddr(asoc, &from_addr);

	/* This should never happen, but lets log it if so.  */
	if (unlikely(!link)) {
		if (from_addr.sa.sa_family == AF_INET6) {
			net_warn_ratelimited("%s association %p could not find address %pI6\n",
					     __func__,
					     asoc,
					     &from_addr.v6.sin6_addr);
		} else {
			net_warn_ratelimited("%s association %p could not find address %pI4\n",
					     __func__,
					     asoc,
					     &from_addr.v4.sin_addr.s_addr);
		}
		return SCTP_DISPOSITION_DISCARD;
	}

	/* Validate the 64-bit random nonce. */
	if (hbinfo->hb_nonce != link->hb_nonce)
		return SCTP_DISPOSITION_DISCARD;

	if (hbinfo->probe_size) {
		if (hbinfo->probe_size != link->pl.probe_size ||
		    !sctp_transport_pl_enabled(link))
			return SCTP_DISPOSITION_DISCARD;

		if (sctp_transport_pl_recv(link))
			return SCTP_DISPOSITION_CONSUME;

		return sctp_sf_send_probe(net, ep, asoc, type, link, commands);
	}

	max_interval = link->hbinterval + link->rto;

	/* Check if the timestamp looks valid.  */
	if (time_after(hbinfo->sent_at, jiffies) ||
	    time_after(jiffies, hbinfo->sent_at + max_interval)) {
		pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
			 "for transport:%p\n", __func__, link);

		return SCTP_DISPOSITION_DISCARD;
	}

	/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
	 * the HEARTBEAT should clear the error counter of the
	 * destination transport address to which the HEARTBEAT was
	 * sent and mark the destination transport address as active if
	 * it is not so marked.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));

	return SCTP_DISPOSITION_CONSUME;
}

/* Helper function to send out an abort for the restart
 * condition.
 */
static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
				      struct sctp_chunk *init,
				      struct sctp_cmd_seq *commands)
{
	struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
	union sctp_addr_param *addrparm;
	struct sctp_errhdr *errhdr;
	char buffer[sizeof(*errhdr) + sizeof(*addrparm)];
	struct sctp_endpoint *ep;
	struct sctp_packet *pkt;
	int len;

	/* Build the error on the stack.   We are way to malloc crazy
	 * throughout the code today.
	 */
	errhdr = (struct sctp_errhdr *)buffer;
	addrparm = (union sctp_addr_param *)errhdr->variable;

	/* Copy into a parm format. */
	len = af->to_addr_param(ssa, addrparm);
	len += sizeof(*errhdr);

	errhdr->cause = SCTP_ERROR_RESTART;
	errhdr->length = htons(len);

	/* Assign to the control socket. */
	ep = sctp_sk(net->sctp.ctl_sock)->ep;

	/* Association is NULL since this may be a restart attack and we
	 * want to send back the attacker's vtag.
	 */
	pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);

	if (!pkt)
		goto out;
	sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));

	SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);

	/* Discard the rest of the inbound packet. */
	sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());

out:
	/* Even if there is no memory, treat as a failure so
	 * the packet will get dropped.
	 */
	return 0;
}

static bool list_has_sctp_addr(const struct list_head *list,
			       union sctp_addr *ipaddr)
{
	struct sctp_transport *addr;

	list_for_each_entry(addr, list, transports) {
		if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
			return true;
	}

	return false;
}
/* A restart is occurring, check to make sure no new addresses
 * are being added as we may be under a takeover attack.
 */
static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
				       const struct sctp_association *asoc,
				       struct sctp_chunk *init,
				       struct sctp_cmd_seq *commands)
{
	struct net *net = new_asoc->base.net;
	struct sctp_transport *new_addr;
	int ret = 1;

	/* Implementor's Guide - Section 5.2.2
	 * ...
	 * Before responding the endpoint MUST check to see if the
	 * unexpected INIT adds new addresses to the association. If new
	 * addresses are added to the association, the endpoint MUST respond
	 * with an ABORT..
	 */

	/* Search through all current addresses and make sure
	 * we aren't adding any new ones.
	 */
	list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
			    transports) {
		if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
					&new_addr->ipaddr)) {
			sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
						   commands);
			ret = 0;
			break;
		}
	}

	/* Return success if all addresses were found. */
	return ret;
}

/* Populate the verification/tie tags based on overlapping INIT
 * scenario.
 *
 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
 */
static void sctp_tietags_populate(struct sctp_association *new_asoc,
				  const struct sctp_association *asoc)
{
	switch (asoc->state) {

	/* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */

	case SCTP_STATE_COOKIE_WAIT:
		new_asoc->c.my_vtag     = asoc->c.my_vtag;
		new_asoc->c.my_ttag     = asoc->c.my_vtag;
		new_asoc->c.peer_ttag   = 0;
		break;

	case SCTP_STATE_COOKIE_ECHOED:
		new_asoc->c.my_vtag     = asoc->c.my_vtag;
		new_asoc->c.my_ttag     = asoc->c.my_vtag;
		new_asoc->c.peer_ttag   = asoc->c.peer_vtag;
		break;

	/* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
	 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
	 */
	default:
		new_asoc->c.my_ttag   = asoc->c.my_vtag;
		new_asoc->c.peer_ttag = asoc->c.peer_vtag;
		break;
	}

	/* Other parameters for the endpoint SHOULD be copied from the
	 * existing parameters of the association (e.g. number of
	 * outbound streams) into the INIT ACK and cookie.
	 */
	new_asoc->rwnd                  = asoc->rwnd;
	new_asoc->c.sinit_num_ostreams  = asoc->c.sinit_num_ostreams;
	new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
	new_asoc->c.initial_tsn         = asoc->c.initial_tsn;
}

/*
 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
 * handling action.
 *
 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
 *
 * Returns value representing action to be taken.   These action values
 * correspond to Action/Description values in RFC 2960, Table 2.
 */
static char sctp_tietags_compare(struct sctp_association *new_asoc,
				 const struct sctp_association *asoc)
{
	/* In this case, the peer may have restarted.  */
	if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
	    (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
	    (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
	    (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
		return 'A';

	/* Collision case B. */
	if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
	    ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
	     (0 == asoc->c.peer_vtag))) {
		return 'B';
	}

	/* Collision case D. */
	if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
	    (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
		return 'D';

	/* Collision case C. */
	if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
	    (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
	    (0 == new_asoc->c.my_ttag) &&
	    (0 == new_asoc->c.peer_ttag))
		return 'C';

	/* No match to any of the special cases; discard this packet. */
	return 'E';
}

/* Common helper routine for both duplicate and simultaneous INIT
 * chunk handling.
 */
static enum sctp_disposition sctp_sf_do_unexpected_init(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg, *repl, *err_chunk;
	struct sctp_unrecognized_param *unk_param;
	struct sctp_association *new_asoc;
	enum sctp_disposition retval;
	struct sctp_packet *packet;
	int len;

	/* 6.10 Bundling
	 * An endpoint MUST NOT bundle INIT, INIT ACK or
	 * SHUTDOWN COMPLETE with any other chunks.
	 *
	 * IG Section 2.11.2
	 * Furthermore, we require that the receiver of an INIT chunk MUST
	 * enforce these rules by silently discarding an arriving packet
	 * with an INIT chunk that is bundled with other chunks.
	 */
	if (!chunk->singleton)
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the INIT chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
	 * Tag.
	 */
	if (chunk->sctp_hdr->vtag != 0)
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);

	if (SCTP_INPUT_CB(chunk->skb)->encap_port != chunk->transport->encap_port)
		return sctp_sf_new_encap_port(net, ep, asoc, type, arg, commands);

	/* Grab the INIT header.  */
	chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;

	/* Tag the variable length parameters.  */
	chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));

	/* Verify the INIT chunk before processing it. */
	err_chunk = NULL;
	if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
			      (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
			      &err_chunk)) {
		/* This chunk contains fatal error. It is to be discarded.
		 * Send an ABORT, with causes if there is any.
		 */
		if (err_chunk) {
			packet = sctp_abort_pkt_new(net, ep, asoc, arg,
					(__u8 *)(err_chunk->chunk_hdr) +
					sizeof(struct sctp_chunkhdr),
					ntohs(err_chunk->chunk_hdr->length) -
					sizeof(struct sctp_chunkhdr));

			if (packet) {
				sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
						SCTP_PACKET(packet));
				SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
				retval = SCTP_DISPOSITION_CONSUME;
			} else {
				retval = SCTP_DISPOSITION_NOMEM;
			}
			goto cleanup;
		} else {
			return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
						    commands);
		}
	}

	/*
	 * Other parameters for the endpoint SHOULD be copied from the
	 * existing parameters of the association (e.g. number of
	 * outbound streams) into the INIT ACK and cookie.
	 * FIXME:  We are copying parameters from the endpoint not the
	 * association.
	 */
	new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
	if (!new_asoc)
		goto nomem;

	/* Update socket peer label if first association. */
	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
		sctp_association_free(new_asoc);
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
				sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
		goto nomem;

	/* In the outbound INIT ACK the endpoint MUST copy its current
	 * Verification Tag and Peers Verification tag into a reserved
	 * place (local tie-tag and per tie-tag) within the state cookie.
	 */
	if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
			       (struct sctp_init_chunk *)chunk->chunk_hdr,
			       GFP_ATOMIC))
		goto nomem;

	/* Make sure no new addresses are being added during the
	 * restart.   Do not do this check for COOKIE-WAIT state,
	 * since there are no peer addresses to check against.
	 * Upon return an ABORT will have been sent if needed.
	 */
	if (!sctp_state(asoc, COOKIE_WAIT)) {
		if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
						 commands)) {
			retval = SCTP_DISPOSITION_CONSUME;
			goto nomem_retval;
		}
	}

	sctp_tietags_populate(new_asoc, asoc);

	/* B) "Z" shall respond immediately with an INIT ACK chunk.  */

	/* If there are errors need to be reported for unknown parameters,
	 * make sure to reserve enough room in the INIT ACK for them.
	 */
	len = 0;
	if (err_chunk) {
		len = ntohs(err_chunk->chunk_hdr->length) -
		      sizeof(struct sctp_chunkhdr);
	}

	repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
	if (!repl)
		goto nomem;

	/* If there are errors need to be reported for unknown parameters,
	 * include them in the outgoing INIT ACK as "Unrecognized parameter"
	 * parameter.
	 */
	if (err_chunk) {
		/* Get the "Unrecognized parameter" parameter(s) out of the
		 * ERROR chunk generated by sctp_verify_init(). Since the
		 * error cause code for "unknown parameter" and the
		 * "Unrecognized parameter" type is the same, we can
		 * construct the parameters in INIT ACK by copying the
		 * ERROR causes over.
		 */
		unk_param = (struct sctp_unrecognized_param *)
			    ((__u8 *)(err_chunk->chunk_hdr) +
			    sizeof(struct sctp_chunkhdr));
		/* Replace the cause code with the "Unrecognized parameter"
		 * parameter type.
		 */
		sctp_addto_chunk(repl, len, unk_param);
	}

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));

	/*
	 * Note: After sending out INIT ACK with the State Cookie parameter,
	 * "Z" MUST NOT allocate any resources for this new association.
	 * Otherwise, "Z" will be vulnerable to resource attacks.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
	retval = SCTP_DISPOSITION_CONSUME;

	return retval;

nomem:
	retval = SCTP_DISPOSITION_NOMEM;
nomem_retval:
	if (new_asoc)
		sctp_association_free(new_asoc);
cleanup:
	if (err_chunk)
		sctp_chunk_free(err_chunk);
	return retval;
}

/*
 * Handle simultaneous INIT.
 * This means we started an INIT and then we got an INIT request from
 * our peer.
 *
 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
 * This usually indicates an initialization collision, i.e., each
 * endpoint is attempting, at about the same time, to establish an
 * association with the other endpoint.
 *
 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
 * endpoint MUST respond with an INIT ACK using the same parameters it
 * sent in its original INIT chunk (including its Verification Tag,
 * unchanged). These original parameters are combined with those from the
 * newly received INIT chunk. The endpoint shall also generate a State
 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
 * INIT to calculate the State Cookie.
 *
 * After that, the endpoint MUST NOT change its state, the T1-init
 * timer shall be left running and the corresponding TCB MUST NOT be
 * destroyed. The normal procedures for handling State Cookies when
 * a TCB exists will resolve the duplicate INITs to a single association.
 *
 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
 * its Tie-Tags with the Tag information of itself and its peer (see
 * section 5.2.2 for a description of the Tie-Tags).
 *
 * Verification Tag: Not explicit, but an INIT can not have a valid
 * verification tag, so we skip the check.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_2_1_siminit(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* Call helper to do the real work for both simultaneous and
	 * duplicate INIT chunk handling.
	 */
	return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
}

/*
 * Handle duplicated INIT messages.  These are usually delayed
 * restransmissions.
 *
 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
 * COOKIE-ECHOED and COOKIE-WAIT
 *
 * Unless otherwise stated, upon reception of an unexpected INIT for
 * this association, the endpoint shall generate an INIT ACK with a
 * State Cookie.  In the outbound INIT ACK the endpoint MUST copy its
 * current Verification Tag and peer's Verification Tag into a reserved
 * place within the state cookie.  We shall refer to these locations as
 * the Peer's-Tie-Tag and the Local-Tie-Tag.  The outbound SCTP packet
 * containing this INIT ACK MUST carry a Verification Tag value equal to
 * the Initiation Tag found in the unexpected INIT.  And the INIT ACK
 * MUST contain a new Initiation Tag (randomly generated see Section
 * 5.3.1).  Other parameters for the endpoint SHOULD be copied from the
 * existing parameters of the association (e.g. number of outbound
 * streams) into the INIT ACK and cookie.
 *
 * After sending out the INIT ACK, the endpoint shall take no further
 * actions, i.e., the existing association, including its current state,
 * and the corresponding TCB MUST NOT be changed.
 *
 * Note: Only when a TCB exists and the association is not in a COOKIE-
 * WAIT state are the Tie-Tags populated.  For a normal association INIT
 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
 * set to 0 (indicating that no previous TCB existed).  The INIT ACK and
 * State Cookie are populated as specified in section 5.2.1.
 *
 * Verification Tag: Not specified, but an INIT has no way of knowing
 * what the verification tag could be, so we ignore it.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_2_2_dupinit(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* Call helper to do the real work for both simultaneous and
	 * duplicate INIT chunk handling.
	 */
	return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
}


/*
 * Unexpected INIT-ACK handler.
 *
 * Section 5.2.3
 * If an INIT ACK received by an endpoint in any state other than the
 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
 * An unexpected INIT ACK usually indicates the processing of an old or
 * duplicated INIT chunk.
*/
enum sctp_disposition sctp_sf_do_5_2_3_initack(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* Per the above section, we'll discard the chunk if we have an
	 * endpoint.  If this is an OOTB INIT-ACK, treat it as such.
	 */
	if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
		return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
	else
		return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
}

static int sctp_sf_do_assoc_update(struct sctp_association *asoc,
				   struct sctp_association *new,
				   struct sctp_cmd_seq *cmds)
{
	struct net *net = asoc->base.net;
	struct sctp_chunk *abort;

	if (!sctp_assoc_update(asoc, new))
		return 0;

	abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
	if (abort) {
		sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
		sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
	}
	sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
	sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
			SCTP_PERR(SCTP_ERROR_RSRC_LOW));
	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);

	return -ENOMEM;
}

/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
 *
 * Section 5.2.4
 *  A)  In this case, the peer may have restarted.
 */
static enum sctp_disposition sctp_sf_do_dupcook_a(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk,
					struct sctp_cmd_seq *commands,
					struct sctp_association *new_asoc)
{
	struct sctp_init_chunk *peer_init;
	enum sctp_disposition disposition;
	struct sctp_ulpevent *ev;
	struct sctp_chunk *repl;
	struct sctp_chunk *err;

	/* new_asoc is a brand-new association, so these are not yet
	 * side effects--it is safe to run them here.
	 */
	peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];

	if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
			       GFP_ATOMIC))
		goto nomem;

	if (sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC))
		goto nomem;

	if (!sctp_auth_chunk_verify(net, chunk, new_asoc))
		return SCTP_DISPOSITION_DISCARD;

	/* Make sure no new addresses are being added during the
	 * restart.  Though this is a pretty complicated attack
	 * since you'd have to get inside the cookie.
	 */
	if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands))
		return SCTP_DISPOSITION_CONSUME;

	/* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
	 * the peer has restarted (Action A), it MUST NOT setup a new
	 * association but instead resend the SHUTDOWN ACK and send an ERROR
	 * chunk with a "Cookie Received while Shutting Down" error cause to
	 * its peer.
	*/
	if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
		disposition = __sctp_sf_do_9_2_reshutack(net, ep, asoc,
							 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
							 chunk, commands);
		if (SCTP_DISPOSITION_NOMEM == disposition)
			goto nomem;

		err = sctp_make_op_error(asoc, chunk,
					 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
					 NULL, 0, 0);
		if (err)
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(err));

		return SCTP_DISPOSITION_CONSUME;
	}

	/* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
	 * data. Consider the optional choice of resending of this data.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
	sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());

	/* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
	 * and ASCONF-ACK cache.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
	sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());

	/* Update the content of current association. */
	if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands))
		goto nomem;

	repl = sctp_make_cookie_ack(asoc, chunk);
	if (!repl)
		goto nomem;

	/* Report association restart to upper layer. */
	ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
					     asoc->c.sinit_num_ostreams,
					     asoc->c.sinit_max_instreams,
					     NULL, GFP_ATOMIC);
	if (!ev)
		goto nomem_ev;

	sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
	if ((sctp_state(asoc, SHUTDOWN_PENDING) ||
	     sctp_state(asoc, SHUTDOWN_SENT)) &&
	    (sctp_sstate(asoc->base.sk, CLOSING) ||
	     sock_flag(asoc->base.sk, SOCK_DEAD))) {
		/* If the socket has been closed by user, don't
		 * transition to ESTABLISHED. Instead trigger SHUTDOWN
		 * bundled with COOKIE_ACK.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
		return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
						     SCTP_ST_CHUNK(0), repl,
						     commands);
	} else {
		sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
				SCTP_STATE(SCTP_STATE_ESTABLISHED));
		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
	}
	return SCTP_DISPOSITION_CONSUME;

nomem_ev:
	sctp_chunk_free(repl);
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
 *
 * Section 5.2.4
 *   B) In this case, both sides may be attempting to start an association
 *      at about the same time but the peer endpoint started its INIT
 *      after responding to the local endpoint's INIT
 */
/* This case represents an initialization collision.  */
static enum sctp_disposition sctp_sf_do_dupcook_b(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk,
					struct sctp_cmd_seq *commands,
					struct sctp_association *new_asoc)
{
	struct sctp_init_chunk *peer_init;
	struct sctp_chunk *repl;

	/* new_asoc is a brand-new association, so these are not yet
	 * side effects--it is safe to run them here.
	 */
	peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
	if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
			       GFP_ATOMIC))
		goto nomem;

	if (sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC))
		goto nomem;

	if (!sctp_auth_chunk_verify(net, chunk, new_asoc))
		return SCTP_DISPOSITION_DISCARD;

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_ESTABLISHED));
	if (asoc->state < SCTP_STATE_ESTABLISHED)
		SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());

	/* Update the content of current association.  */
	if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands))
		goto nomem;

	repl = sctp_make_cookie_ack(asoc, chunk);
	if (!repl)
		goto nomem;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));

	/* RFC 2960 5.1 Normal Establishment of an Association
	 *
	 * D) IMPLEMENTATION NOTE: An implementation may choose to
	 * send the Communication Up notification to the SCTP user
	 * upon reception of a valid COOKIE ECHO chunk.
	 *
	 * Sadly, this needs to be implemented as a side-effect, because
	 * we are not guaranteed to have set the association id of the real
	 * association and so these notifications need to be delayed until
	 * the association id is allocated.
	 */

	sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));

	/* Sockets API Draft Section 5.3.1.6
	 * When a peer sends a Adaptation Layer Indication parameter , SCTP
	 * delivers this notification to inform the application that of the
	 * peers requested adaptation layer.
	 *
	 * This also needs to be done as a side effect for the same reason as
	 * above.
	 */
	if (asoc->peer.adaptation_ind)
		sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());

	if (!asoc->peer.auth_capable)
		sctp_add_cmd_sf(commands, SCTP_CMD_PEER_NO_AUTH, SCTP_NULL());

	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
 *
 * Section 5.2.4
 *  C) In this case, the local endpoint's cookie has arrived late.
 *     Before it arrived, the local endpoint sent an INIT and received an
 *     INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
 *     but a new tag of its own.
 */
/* This case represents an initialization collision.  */
static enum sctp_disposition sctp_sf_do_dupcook_c(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk,
					struct sctp_cmd_seq *commands,
					struct sctp_association *new_asoc)
{
	/* The cookie should be silently discarded.
	 * The endpoint SHOULD NOT change states and should leave
	 * any timers running.
	 */
	return SCTP_DISPOSITION_DISCARD;
}

/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
 *
 * Section 5.2.4
 *
 * D) When both local and remote tags match the endpoint should always
 *    enter the ESTABLISHED state, if it has not already done so.
 */
/* This case represents an initialization collision.  */
static enum sctp_disposition sctp_sf_do_dupcook_d(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk,
					struct sctp_cmd_seq *commands,
					struct sctp_association *new_asoc)
{
	struct sctp_ulpevent *ev = NULL, *ai_ev = NULL, *auth_ev = NULL;
	struct sctp_chunk *repl;

	/* Clarification from Implementor's Guide:
	 * D) When both local and remote tags match the endpoint should
	 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
	 * It should stop any cookie timer that may be running and send
	 * a COOKIE ACK.
	 */

	if (!sctp_auth_chunk_verify(net, chunk, asoc))
		return SCTP_DISPOSITION_DISCARD;

	/* Don't accidentally move back into established state. */
	if (asoc->state < SCTP_STATE_ESTABLISHED) {
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
		sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
				SCTP_STATE(SCTP_STATE_ESTABLISHED));
		SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
		sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
				SCTP_NULL());

		/* RFC 2960 5.1 Normal Establishment of an Association
		 *
		 * D) IMPLEMENTATION NOTE: An implementation may choose
		 * to send the Communication Up notification to the
		 * SCTP user upon reception of a valid COOKIE
		 * ECHO chunk.
		 */
		ev = sctp_ulpevent_make_assoc_change(asoc, 0,
					     SCTP_COMM_UP, 0,
					     asoc->c.sinit_num_ostreams,
					     asoc->c.sinit_max_instreams,
					     NULL, GFP_ATOMIC);
		if (!ev)
			goto nomem;

		/* Sockets API Draft Section 5.3.1.6
		 * When a peer sends a Adaptation Layer Indication parameter,
		 * SCTP delivers this notification to inform the application
		 * that of the peers requested adaptation layer.
		 */
		if (asoc->peer.adaptation_ind) {
			ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
								 GFP_ATOMIC);
			if (!ai_ev)
				goto nomem;

		}

		if (!asoc->peer.auth_capable) {
			auth_ev = sctp_ulpevent_make_authkey(asoc, 0,
							     SCTP_AUTH_NO_AUTH,
							     GFP_ATOMIC);
			if (!auth_ev)
				goto nomem;
		}
	}

	repl = sctp_make_cookie_ack(asoc, chunk);
	if (!repl)
		goto nomem;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));

	if (ev)
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(ev));
	if (ai_ev)
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
					SCTP_ULPEVENT(ai_ev));
	if (auth_ev)
		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(auth_ev));

	return SCTP_DISPOSITION_CONSUME;

nomem:
	if (auth_ev)
		sctp_ulpevent_free(auth_ev);
	if (ai_ev)
		sctp_ulpevent_free(ai_ev);
	if (ev)
		sctp_ulpevent_free(ev);
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Handle a duplicate COOKIE-ECHO.  This usually means a cookie-carrying
 * chunk was retransmitted and then delayed in the network.
 *
 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
 *
 * Verification Tag: None.  Do cookie validation.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_association *new_asoc;
	struct sctp_chunk *chunk = arg;
	enum sctp_disposition retval;
	struct sctp_chunk *err_chk_p;
	int error = 0;
	char action;

	/* Make sure that the chunk has a valid length from the protocol
	 * perspective.  In this case check to make sure we have at least
	 * enough for the chunk header.  Cookie length verification is
	 * done later.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) {
		if (!sctp_vtag_verify(chunk, asoc))
			asoc = NULL;
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, commands);
	}

	/* "Decode" the chunk.  We have no optional parameters so we
	 * are in good shape.
	 */
	chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
	if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
					sizeof(struct sctp_chunkhdr)))
		goto nomem;

	/* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
	 * of a duplicate COOKIE ECHO match the Verification Tags of the
	 * current association, consider the State Cookie valid even if
	 * the lifespan is exceeded.
	 */
	new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
				      &err_chk_p);

	/* FIXME:
	 * If the re-build failed, what is the proper error path
	 * from here?
	 *
	 * [We should abort the association. --piggy]
	 */
	if (!new_asoc) {
		/* FIXME: Several errors are possible.  A bad cookie should
		 * be silently discarded, but think about logging it too.
		 */
		switch (error) {
		case -SCTP_IERROR_NOMEM:
			goto nomem;

		case -SCTP_IERROR_STALE_COOKIE:
			sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
						   err_chk_p);
			return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
		case -SCTP_IERROR_BAD_SIG:
		default:
			return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
		}
	}

	/* Update socket peer label if first association. */
	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
		sctp_association_free(new_asoc);
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	/* Set temp so that it won't be added into hashtable */
	new_asoc->temp = 1;

	/* Compare the tie_tag in cookie with the verification tag of
	 * current association.
	 */
	action = sctp_tietags_compare(new_asoc, asoc);

	switch (action) {
	case 'A': /* Association restart. */
		retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
					      new_asoc);
		break;

	case 'B': /* Collision case B. */
		retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
					      new_asoc);
		break;

	case 'C': /* Collision case C. */
		retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
					      new_asoc);
		break;

	case 'D': /* Collision case D. */
		retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
					      new_asoc);
		break;

	default: /* Discard packet for all others. */
		retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
		break;
	}

	/* Delete the temporary new association. */
	sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());

	/* Restore association pointer to provide SCTP command interpreter
	 * with a valid context in case it needs to manipulate
	 * the queues */
	sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
			 SCTP_ASOC((struct sctp_association *)asoc));

	return retval;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Process an ABORT.  (SHUTDOWN-PENDING state)
 *
 * See sctp_sf_do_9_1_abort().
 */
enum sctp_disposition sctp_sf_shutdown_pending_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!sctp_vtag_verify_either(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ABORT chunk has a valid length.
	 * Since this is an ABORT chunk, we have to discard it
	 * because of the following text:
	 * RFC 2960, Section 3.3.7
	 *    If an endpoint receives an ABORT with a format error or for an
	 *    association that doesn't exist, it MUST silently discard it.
	 * Because the length is "invalid", we can't really discard just
	 * as we do not know its true length.  So, to be safe, discard the
	 * packet.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* ADD-IP: Special case for ABORT chunks
	 * F4)  One special consideration is that ABORT Chunks arriving
	 * destined to the IP address being deleted MUST be
	 * ignored (see Section 5.3.1 for further details).
	 */
	if (SCTP_ADDR_DEL ==
		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (!sctp_err_chunk_valid(chunk))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
}

/*
 * Process an ABORT.  (SHUTDOWN-SENT state)
 *
 * See sctp_sf_do_9_1_abort().
 */
enum sctp_disposition sctp_sf_shutdown_sent_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!sctp_vtag_verify_either(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ABORT chunk has a valid length.
	 * Since this is an ABORT chunk, we have to discard it
	 * because of the following text:
	 * RFC 2960, Section 3.3.7
	 *    If an endpoint receives an ABORT with a format error or for an
	 *    association that doesn't exist, it MUST silently discard it.
	 * Because the length is "invalid", we can't really discard just
	 * as we do not know its true length.  So, to be safe, discard the
	 * packet.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* ADD-IP: Special case for ABORT chunks
	 * F4)  One special consideration is that ABORT Chunks arriving
	 * destined to the IP address being deleted MUST be
	 * ignored (see Section 5.3.1 for further details).
	 */
	if (SCTP_ADDR_DEL ==
		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (!sctp_err_chunk_valid(chunk))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Stop the T2-shutdown timer. */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	/* Stop the T5-shutdown guard timer.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));

	return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
}

/*
 * Process an ABORT.  (SHUTDOWN-ACK-SENT state)
 *
 * See sctp_sf_do_9_1_abort().
 */
enum sctp_disposition sctp_sf_shutdown_ack_sent_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* The same T2 timer, so we should be able to use
	 * common function with the SHUTDOWN-SENT state.
	 */
	return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
}

/*
 * Handle an Error received in COOKIE_ECHOED state.
 *
 * Only handle the error type of stale COOKIE Error, the other errors will
 * be ignored.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_cookie_echoed_err(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_errhdr *err;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ERROR chunk has a valid length.
	 * The parameter walking depends on this as well.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* Process the error here */
	/* FUTURE FIXME:  When PR-SCTP related and other optional
	 * parms are emitted, this will have to change to handle multiple
	 * errors.
	 */
	sctp_walk_errors(err, chunk->chunk_hdr) {
		if (SCTP_ERROR_STALE_COOKIE == err->cause)
			return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
							arg, commands);
	}

	/* It is possible to have malformed error causes, and that
	 * will cause us to end the walk early.  However, since
	 * we are discarding the packet, there should be no adverse
	 * affects.
	 */
	return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
}

/*
 * Handle a Stale COOKIE Error
 *
 * Section: 5.2.6 Handle Stale COOKIE Error
 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
 * one of the following three alternatives.
 * ...
 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
 *    Preservative parameter requesting an extension to the lifetime of
 *    the State Cookie. When calculating the time extension, an
 *    implementation SHOULD use the RTT information measured based on the
 *    previous COOKIE ECHO / ERROR exchange, and should add no more
 *    than 1 second beyond the measured RTT, due to long State Cookie
 *    lifetimes making the endpoint more subject to a replay attack.
 *
 * Verification Tag:  Not explicit, but safe to ignore.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
static enum sctp_disposition sctp_sf_do_5_2_6_stale(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	int attempts = asoc->init_err_counter + 1;
	struct sctp_chunk *chunk = arg, *reply;
	struct sctp_cookie_preserve_param bht;
	struct sctp_bind_addr *bp;
	struct sctp_errhdr *err;
	u32 stale;

	if (attempts > asoc->max_init_attempts) {
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
				SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
		return SCTP_DISPOSITION_DELETE_TCB;
	}

	err = (struct sctp_errhdr *)(chunk->skb->data);

	/* When calculating the time extension, an implementation
	 * SHOULD use the RTT information measured based on the
	 * previous COOKIE ECHO / ERROR exchange, and should add no
	 * more than 1 second beyond the measured RTT, due to long
	 * State Cookie lifetimes making the endpoint more subject to
	 * a replay attack.
	 * Measure of Staleness's unit is usec. (1/1000000 sec)
	 * Suggested Cookie Life-span Increment's unit is msec.
	 * (1/1000 sec)
	 * In general, if you use the suggested cookie life, the value
	 * found in the field of measure of staleness should be doubled
	 * to give ample time to retransmit the new cookie and thus
	 * yield a higher probability of success on the reattempt.
	 */
	stale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err)));
	stale = (stale * 2) / 1000;

	bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
	bht.param_hdr.length = htons(sizeof(bht));
	bht.lifespan_increment = htonl(stale);

	/* Build that new INIT chunk.  */
	bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
	reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
	if (!reply)
		goto nomem;

	sctp_addto_chunk(reply, sizeof(bht), &bht);

	/* Clear peer's init_tag cached in assoc as we are sending a new INIT */
	sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());

	/* Stop pending T3-rtx and heartbeat timers */
	sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());

	/* Delete non-primary peer ip addresses since we are transitioning
	 * back to the COOKIE-WAIT state
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());

	/* If we've sent any data bundled with COOKIE-ECHO we will need to
	 * resend
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
			SCTP_TRANSPORT(asoc->peer.primary_path));

	/* Cast away the const modifier, as we want to just
	 * rerun it through as a sideffect.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());

	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));

	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Process an ABORT.
 *
 * Section: 9.1
 * After checking the Verification Tag, the receiving endpoint shall
 * remove the association from its record, and shall report the
 * termination to its upper layer.
 *
 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
 * B) Rules for packet carrying ABORT:
 *
 *  - The endpoint shall always fill in the Verification Tag field of the
 *    outbound packet with the destination endpoint's tag value if it
 *    is known.
 *
 *  - If the ABORT is sent in response to an OOTB packet, the endpoint
 *    MUST follow the procedure described in Section 8.4.
 *
 *  - The receiver MUST accept the packet if the Verification Tag
 *    matches either its own tag, OR the tag of its peer. Otherwise, the
 *    receiver MUST silently discard the packet and take no further
 *    action.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_9_1_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!sctp_vtag_verify_either(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ABORT chunk has a valid length.
	 * Since this is an ABORT chunk, we have to discard it
	 * because of the following text:
	 * RFC 2960, Section 3.3.7
	 *    If an endpoint receives an ABORT with a format error or for an
	 *    association that doesn't exist, it MUST silently discard it.
	 * Because the length is "invalid", we can't really discard just
	 * as we do not know its true length.  So, to be safe, discard the
	 * packet.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* ADD-IP: Special case for ABORT chunks
	 * F4)  One special consideration is that ABORT Chunks arriving
	 * destined to the IP address being deleted MUST be
	 * ignored (see Section 5.3.1 for further details).
	 */
	if (SCTP_ADDR_DEL ==
		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (!sctp_err_chunk_valid(chunk))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
}

static enum sctp_disposition __sctp_sf_do_9_1_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	__be16 error = SCTP_ERROR_NO_ERROR;
	struct sctp_chunk *chunk = arg;
	unsigned int len;

	/* See if we have an error cause code in the chunk.  */
	len = ntohs(chunk->chunk_hdr->length);
	if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
		error = ((struct sctp_errhdr *)chunk->skb->data)->cause;

	sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
	/* ASSOC_FAILED will DELETE_TCB. */
	sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);

	return SCTP_DISPOSITION_ABORT;
}

/*
 * Process an ABORT.  (COOKIE-WAIT state)
 *
 * See sctp_sf_do_9_1_abort() above.
 */
enum sctp_disposition sctp_sf_cookie_wait_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	__be16 error = SCTP_ERROR_NO_ERROR;
	struct sctp_chunk *chunk = arg;
	unsigned int len;

	if (!sctp_vtag_verify_either(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ABORT chunk has a valid length.
	 * Since this is an ABORT chunk, we have to discard it
	 * because of the following text:
	 * RFC 2960, Section 3.3.7
	 *    If an endpoint receives an ABORT with a format error or for an
	 *    association that doesn't exist, it MUST silently discard it.
	 * Because the length is "invalid", we can't really discard just
	 * as we do not know its true length.  So, to be safe, discard the
	 * packet.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* See if we have an error cause code in the chunk.  */
	len = ntohs(chunk->chunk_hdr->length);
	if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
		error = ((struct sctp_errhdr *)chunk->skb->data)->cause;

	return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
				      chunk->transport);
}

/*
 * Process an incoming ICMP as an ABORT.  (COOKIE-WAIT state)
 */
enum sctp_disposition sctp_sf_cookie_wait_icmp_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
				      ENOPROTOOPT, asoc,
				      (struct sctp_transport *)arg);
}

/*
 * Process an ABORT.  (COOKIE-ECHOED state)
 */
enum sctp_disposition sctp_sf_cookie_echoed_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* There is a single T1 timer, so we should be able to use
	 * common function with the COOKIE-WAIT state.
	 */
	return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
}

/*
 * Stop T1 timer and abort association with "INIT failed".
 *
 * This is common code called by several sctp_sf_*_abort() functions above.
 */
static enum sctp_disposition sctp_stop_t1_and_abort(
					struct net *net,
					struct sctp_cmd_seq *commands,
					__be16 error, int sk_err,
					const struct sctp_association *asoc,
					struct sctp_transport *transport)
{
	pr_debug("%s: ABORT received (INIT)\n", __func__);

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_CLOSED));
	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
	sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
	/* CMD_INIT_FAILED will DELETE_TCB. */
	sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
			SCTP_PERR(error));

	return SCTP_DISPOSITION_ABORT;
}

/*
 * sctp_sf_do_9_2_shut
 *
 * Section: 9.2
 * Upon the reception of the SHUTDOWN, the peer endpoint shall
 *  - enter the SHUTDOWN-RECEIVED state,
 *
 *  - stop accepting new data from its SCTP user
 *
 *  - verify, by checking the Cumulative TSN Ack field of the chunk,
 *    that all its outstanding DATA chunks have been received by the
 *    SHUTDOWN sender.
 *
 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
 * send a SHUTDOWN in response to a ULP request. And should discard
 * subsequent SHUTDOWN chunks.
 *
 * If there are still outstanding DATA chunks left, the SHUTDOWN
 * receiver shall continue to follow normal data transmission
 * procedures defined in Section 6 until all outstanding DATA chunks
 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
 * new data from its SCTP user.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_9_2_shutdown(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	enum sctp_disposition disposition;
	struct sctp_chunk *chunk = arg;
	struct sctp_shutdownhdr *sdh;
	struct sctp_ulpevent *ev;
	__u32 ctsn;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the SHUTDOWN chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* Convert the elaborate header.  */
	sdh = (struct sctp_shutdownhdr *)chunk->skb->data;
	skb_pull(chunk->skb, sizeof(*sdh));
	chunk->subh.shutdown_hdr = sdh;
	ctsn = ntohl(sdh->cum_tsn_ack);

	if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
		pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
			 asoc->ctsn_ack_point);

		return SCTP_DISPOSITION_DISCARD;
	}

	/* If Cumulative TSN Ack beyond the max tsn currently
	 * send, terminating the association and respond to the
	 * sender with an ABORT.
	 */
	if (!TSN_lt(ctsn, asoc->next_tsn))
		return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);

	/* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
	 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
	 * inform the application that it should cease sending data.
	 */
	ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
	if (!ev) {
		disposition = SCTP_DISPOSITION_NOMEM;
		goto out;
	}
	sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));

	/* Upon the reception of the SHUTDOWN, the peer endpoint shall
	 *  - enter the SHUTDOWN-RECEIVED state,
	 *  - stop accepting new data from its SCTP user
	 *
	 * [This is implicit in the new state.]
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
	disposition = SCTP_DISPOSITION_CONSUME;

	if (sctp_outq_is_empty(&asoc->outqueue)) {
		disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
							  arg, commands);
	}

	if (SCTP_DISPOSITION_NOMEM == disposition)
		goto out;

	/*  - verify, by checking the Cumulative TSN Ack field of the
	 *    chunk, that all its outstanding DATA chunks have been
	 *    received by the SHUTDOWN sender.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
			SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));

out:
	return disposition;
}

/*
 * sctp_sf_do_9_2_shut_ctsn
 *
 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
 * it MUST NOT send a SHUTDOWN in response to a ULP request.
 * The Cumulative TSN Ack of the received SHUTDOWN chunk
 * MUST be processed.
 */
enum sctp_disposition sctp_sf_do_9_2_shut_ctsn(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_shutdownhdr *sdh;
	__u32 ctsn;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the SHUTDOWN chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	sdh = (struct sctp_shutdownhdr *)chunk->skb->data;
	ctsn = ntohl(sdh->cum_tsn_ack);

	if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
		pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
			 asoc->ctsn_ack_point);

		return SCTP_DISPOSITION_DISCARD;
	}

	/* If Cumulative TSN Ack beyond the max tsn currently
	 * send, terminating the association and respond to the
	 * sender with an ABORT.
	 */
	if (!TSN_lt(ctsn, asoc->next_tsn))
		return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);

	/* verify, by checking the Cumulative TSN Ack field of the
	 * chunk, that all its outstanding DATA chunks have been
	 * received by the SHUTDOWN sender.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
			SCTP_BE32(sdh->cum_tsn_ack));

	return SCTP_DISPOSITION_CONSUME;
}

/* RFC 2960 9.2
 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
 * transport addresses (either in the IP addresses or in the INIT chunk)
 * that belong to this association, it should discard the INIT chunk and
 * retransmit the SHUTDOWN ACK chunk.
 */
static enum sctp_disposition
__sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
			   const struct sctp_association *asoc,
			   const union sctp_subtype type, void *arg,
			   struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *reply;

	/* Make sure that the chunk has a valid length */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* Since we are not going to really process this INIT, there
	 * is no point in verifying chunk boundaries.  Just generate
	 * the SHUTDOWN ACK.
	 */
	reply = sctp_make_shutdown_ack(asoc, chunk);
	if (NULL == reply)
		goto nomem;

	/* Set the transport for the SHUTDOWN ACK chunk and the timeout for
	 * the T2-SHUTDOWN timer.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));

	/* and restart the T2-shutdown timer. */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));

	return SCTP_DISPOSITION_CONSUME;
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

enum sctp_disposition
sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
			 const struct sctp_association *asoc,
			 const union sctp_subtype type, void *arg,
			 struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!chunk->singleton)
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (chunk->sctp_hdr->vtag != 0)
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);

	return __sctp_sf_do_9_2_reshutack(net, ep, asoc, type, arg, commands);
}

/*
 * sctp_sf_do_ecn_cwr
 *
 * Section:  Appendix A: Explicit Congestion Notification
 *
 * CWR:
 *
 * RFC 2481 details a specific bit for a sender to send in the header of
 * its next outbound TCP segment to indicate to its peer that it has
 * reduced its congestion window.  This is termed the CWR bit.  For
 * SCTP the same indication is made by including the CWR chunk.
 * This chunk contains one data element, i.e. the TSN number that
 * was sent in the ECNE chunk.  This element represents the lowest
 * TSN number in the datagram that was originally marked with the
 * CE bit.
 *
 * Verification Tag: 8.5 Verification Tag [Normal verification]
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_ecn_cwr(struct net *net,
					 const struct sctp_endpoint *ep,
					 const struct sctp_association *asoc,
					 const union sctp_subtype type,
					 void *arg,
					 struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_cwrhdr *cwr;
	u32 lowest_tsn;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	cwr = (struct sctp_cwrhdr *)chunk->skb->data;
	skb_pull(chunk->skb, sizeof(*cwr));

	lowest_tsn = ntohl(cwr->lowest_tsn);

	/* Does this CWR ack the last sent congestion notification? */
	if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
		/* Stop sending ECNE. */
		sctp_add_cmd_sf(commands,
				SCTP_CMD_ECN_CWR,
				SCTP_U32(lowest_tsn));
	}
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * sctp_sf_do_ecne
 *
 * Section:  Appendix A: Explicit Congestion Notification
 *
 * ECN-Echo
 *
 * RFC 2481 details a specific bit for a receiver to send back in its
 * TCP acknowledgements to notify the sender of the Congestion
 * Experienced (CE) bit having arrived from the network.  For SCTP this
 * same indication is made by including the ECNE chunk.  This chunk
 * contains one data element, i.e. the lowest TSN associated with the IP
 * datagram marked with the CE bit.....
 *
 * Verification Tag: 8.5 Verification Tag [Normal verification]
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_ecne(struct net *net,
				      const struct sctp_endpoint *ep,
				      const struct sctp_association *asoc,
				      const union sctp_subtype type,
				      void *arg, struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_ecnehdr *ecne;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	ecne = (struct sctp_ecnehdr *)chunk->skb->data;
	skb_pull(chunk->skb, sizeof(*ecne));

	/* If this is a newer ECNE than the last CWR packet we sent out */
	sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
			SCTP_U32(ntohl(ecne->lowest_tsn)));

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Section: 6.2  Acknowledgement on Reception of DATA Chunks
 *
 * The SCTP endpoint MUST always acknowledge the reception of each valid
 * DATA chunk.
 *
 * The guidelines on delayed acknowledgement algorithm specified in
 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
 * acknowledgement SHOULD be generated for at least every second packet
 * (not every second DATA chunk) received, and SHOULD be generated within
 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
 * situations it may be beneficial for an SCTP transmitter to be more
 * conservative than the algorithms detailed in this document allow.
 * However, an SCTP transmitter MUST NOT be more aggressive than the
 * following algorithms allow.
 *
 * A SCTP receiver MUST NOT generate more than one SACK for every
 * incoming packet, other than to update the offered window as the
 * receiving application consumes new data.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_eat_data_6_2(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	union sctp_arg force = SCTP_NOFORCE();
	struct sctp_chunk *chunk = arg;
	int error;

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	error = sctp_eat_data(asoc, chunk, commands);
	switch (error) {
	case SCTP_IERROR_NO_ERROR:
		break;
	case SCTP_IERROR_HIGH_TSN:
	case SCTP_IERROR_BAD_STREAM:
		SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
		goto discard_noforce;
	case SCTP_IERROR_DUP_TSN:
	case SCTP_IERROR_IGNORE_TSN:
		SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
		goto discard_force;
	case SCTP_IERROR_NO_DATA:
		return SCTP_DISPOSITION_ABORT;
	case SCTP_IERROR_PROTO_VIOLATION:
		return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
					       (u8 *)chunk->subh.data_hdr,
					       sctp_datahdr_len(&asoc->stream));
	default:
		BUG();
	}

	if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
		force = SCTP_FORCE();

	if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
	}

	/* If this is the last chunk in a packet, we need to count it
	 * toward sack generation.  Note that we need to SACK every
	 * OTHER packet containing data chunks, EVEN IF WE DISCARD
	 * THEM.  We elect to NOT generate SACK's if the chunk fails
	 * the verification tag test.
	 *
	 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
	 *
	 * The SCTP endpoint MUST always acknowledge the reception of
	 * each valid DATA chunk.
	 *
	 * The guidelines on delayed acknowledgement algorithm
	 * specified in  Section 4.2 of [RFC2581] SHOULD be followed.
	 * Specifically, an acknowledgement SHOULD be generated for at
	 * least every second packet (not every second DATA chunk)
	 * received, and SHOULD be generated within 200 ms of the
	 * arrival of any unacknowledged DATA chunk.  In some
	 * situations it may be beneficial for an SCTP transmitter to
	 * be more conservative than the algorithms detailed in this
	 * document allow. However, an SCTP transmitter MUST NOT be
	 * more aggressive than the following algorithms allow.
	 */
	if (chunk->end_of_packet)
		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);

	return SCTP_DISPOSITION_CONSUME;

discard_force:
	/* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
	 *
	 * When a packet arrives with duplicate DATA chunk(s) and with
	 * no new DATA chunk(s), the endpoint MUST immediately send a
	 * SACK with no delay.  If a packet arrives with duplicate
	 * DATA chunk(s) bundled with new DATA chunks, the endpoint
	 * MAY immediately send a SACK.  Normally receipt of duplicate
	 * DATA chunks will occur when the original SACK chunk was lost
	 * and the peer's RTO has expired.  The duplicate TSN number(s)
	 * SHOULD be reported in the SACK as duplicate.
	 */
	/* In our case, we split the MAY SACK advice up whether or not
	 * the last chunk is a duplicate.'
	 */
	if (chunk->end_of_packet)
		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
	return SCTP_DISPOSITION_DISCARD;

discard_noforce:
	if (chunk->end_of_packet)
		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);

	return SCTP_DISPOSITION_DISCARD;
}

/*
 * sctp_sf_eat_data_fast_4_4
 *
 * Section: 4 (4)
 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
 *    DATA chunks without delay.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_eat_data_fast_4_4(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	int error;

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	error = sctp_eat_data(asoc, chunk, commands);
	switch (error) {
	case SCTP_IERROR_NO_ERROR:
	case SCTP_IERROR_HIGH_TSN:
	case SCTP_IERROR_DUP_TSN:
	case SCTP_IERROR_IGNORE_TSN:
	case SCTP_IERROR_BAD_STREAM:
		break;
	case SCTP_IERROR_NO_DATA:
		return SCTP_DISPOSITION_ABORT;
	case SCTP_IERROR_PROTO_VIOLATION:
		return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
					       (u8 *)chunk->subh.data_hdr,
					       sctp_datahdr_len(&asoc->stream));
	default:
		BUG();
	}

	/* Go a head and force a SACK, since we are shutting down. */

	/* Implementor's Guide.
	 *
	 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
	 * respond to each received packet containing one or more DATA chunk(s)
	 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
	 */
	if (chunk->end_of_packet) {
		/* We must delay the chunk creation since the cumulative
		 * TSN has not been updated yet.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
		sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
	}

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Section: 6.2  Processing a Received SACK
 * D) Any time a SACK arrives, the endpoint performs the following:
 *
 *     i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
 *     then drop the SACK.   Since Cumulative TSN Ack is monotonically
 *     increasing, a SACK whose Cumulative TSN Ack is less than the
 *     Cumulative TSN Ack Point indicates an out-of-order SACK.
 *
 *     ii) Set rwnd equal to the newly received a_rwnd minus the number
 *     of bytes still outstanding after processing the Cumulative TSN Ack
 *     and the Gap Ack Blocks.
 *
 *     iii) If the SACK is missing a TSN that was previously
 *     acknowledged via a Gap Ack Block (e.g., the data receiver
 *     reneged on the data), then mark the corresponding DATA chunk
 *     as available for retransmit:  Mark it as missing for fast
 *     retransmit as described in Section 7.2.4 and if no retransmit
 *     timer is running for the destination address to which the DATA
 *     chunk was originally transmitted, then T3-rtx is started for
 *     that destination address.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_sackhdr *sackh;
	__u32 ctsn;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the SACK chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_sack_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* Pull the SACK chunk from the data buffer */
	sackh = sctp_sm_pull_sack(chunk);
	/* Was this a bogus SACK? */
	if (!sackh)
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	chunk->subh.sack_hdr = sackh;
	ctsn = ntohl(sackh->cum_tsn_ack);

	/* If Cumulative TSN Ack beyond the max tsn currently
	 * send, terminating the association and respond to the
	 * sender with an ABORT.
	 */
	if (TSN_lte(asoc->next_tsn, ctsn))
		return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);

	trace_sctp_probe(ep, asoc, chunk);

	/* i) If Cumulative TSN Ack is less than the Cumulative TSN
	 *     Ack Point, then drop the SACK.  Since Cumulative TSN
	 *     Ack is monotonically increasing, a SACK whose
	 *     Cumulative TSN Ack is less than the Cumulative TSN Ack
	 *     Point indicates an out-of-order SACK.
	 */
	if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
		pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
			 asoc->ctsn_ack_point);

		return SCTP_DISPOSITION_DISCARD;
	}

	/* Return this SACK for further processing.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));

	/* Note: We do the rest of the work on the PROCESS_SACK
	 * sideeffect.
	 */
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Generate an ABORT in response to a packet.
 *
 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
 *
 * 8) The receiver should respond to the sender of the OOTB packet with
 *    an ABORT.  When sending the ABORT, the receiver of the OOTB packet
 *    MUST fill in the Verification Tag field of the outbound packet
 *    with the value found in the Verification Tag field of the OOTB
 *    packet and set the T-bit in the Chunk Flags to indicate that the
 *    Verification Tag is reflected.  After sending this ABORT, the
 *    receiver of the OOTB packet shall discard the OOTB packet and take
 *    no further action.
 *
 * Verification Tag:
 *
 * The return value is the disposition of the chunk.
*/
static enum sctp_disposition sctp_sf_tabort_8_4_8(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_packet *packet = NULL;
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *abort;

	packet = sctp_ootb_pkt_new(net, asoc, chunk);
	if (!packet)
		return SCTP_DISPOSITION_NOMEM;

	/* Make an ABORT. The T bit will be set if the asoc
	 * is NULL.
	 */
	abort = sctp_make_abort(asoc, chunk, 0);
	if (!abort) {
		sctp_ootb_pkt_free(packet);
		return SCTP_DISPOSITION_NOMEM;
	}

	/* Reflect vtag if T-Bit is set */
	if (sctp_test_T_bit(abort))
		packet->vtag = ntohl(chunk->sctp_hdr->vtag);

	/* Set the skb to the belonging sock for accounting.  */
	abort->skb->sk = ep->base.sk;

	sctp_packet_append_chunk(packet, abort);

	sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(packet));

	SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);

	sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	return SCTP_DISPOSITION_CONSUME;
}

/* Handling of SCTP Packets Containing an INIT Chunk Matching an
 * Existing Associations when the UDP encap port is incorrect.
 *
 * From Section 4 at draft-tuexen-tsvwg-sctp-udp-encaps-cons-03.
 */
static enum sctp_disposition sctp_sf_new_encap_port(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_packet *packet = NULL;
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *abort;

	packet = sctp_ootb_pkt_new(net, asoc, chunk);
	if (!packet)
		return SCTP_DISPOSITION_NOMEM;

	abort = sctp_make_new_encap_port(asoc, chunk);
	if (!abort) {
		sctp_ootb_pkt_free(packet);
		return SCTP_DISPOSITION_NOMEM;
	}

	abort->skb->sk = ep->base.sk;

	sctp_packet_append_chunk(packet, abort);

	sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
			SCTP_PACKET(packet));

	SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);

	sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Received an ERROR chunk from peer.  Generate SCTP_REMOTE_ERROR
 * event as ULP notification for each cause included in the chunk.
 *
 * API 5.3.1.3 - SCTP_REMOTE_ERROR
 *
 * The return value is the disposition of the chunk.
*/
enum sctp_disposition sctp_sf_operr_notify(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_errhdr *err;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ERROR chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);
	sctp_walk_errors(err, chunk->chunk_hdr);
	if ((void *)err != (void *)chunk->chunk_end)
		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
						  (void *)err, commands);

	sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
			SCTP_CHUNK(chunk));

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Process an inbound SHUTDOWN ACK.
 *
 * From Section 9.2:
 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
 * peer, and remove all record of the association.
 *
 * The return value is the disposition.
 */
enum sctp_disposition sctp_sf_do_9_2_final(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *reply;
	struct sctp_ulpevent *ev;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);
	/* 10.2 H) SHUTDOWN COMPLETE notification
	 *
	 * When SCTP completes the shutdown procedures (section 9.2) this
	 * notification is passed to the upper layer.
	 */
	ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
					     0, 0, 0, NULL, GFP_ATOMIC);
	if (!ev)
		goto nomem;

	/* ...send a SHUTDOWN COMPLETE chunk to its peer, */
	reply = sctp_make_shutdown_complete(asoc, chunk);
	if (!reply)
		goto nomem_chunk;

	/* Do all the commands now (after allocation), so that we
	 * have consistent state if memory allocation fails
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));

	/* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
	 * stop the T2-shutdown timer,
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_CLOSED));
	SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));

	/* ...and remove all record of the association. */
	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
	return SCTP_DISPOSITION_DELETE_TCB;

nomem_chunk:
	sctp_ulpevent_free(ev);
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
 *
 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
 *    respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
 *    When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
 *    packet must fill in the Verification Tag field of the outbound
 *    packet with the Verification Tag received in the SHUTDOWN ACK and
 *    set the T-bit in the Chunk Flags to indicate that the Verification
 *    Tag is reflected.
 *
 * 8) The receiver should respond to the sender of the OOTB packet with
 *    an ABORT.  When sending the ABORT, the receiver of the OOTB packet
 *    MUST fill in the Verification Tag field of the outbound packet
 *    with the value found in the Verification Tag field of the OOTB
 *    packet and set the T-bit in the Chunk Flags to indicate that the
 *    Verification Tag is reflected.  After sending this ABORT, the
 *    receiver of the OOTB packet shall discard the OOTB packet and take
 *    no further action.
 */
enum sctp_disposition sctp_sf_ootb(struct net *net,
				   const struct sctp_endpoint *ep,
				   const struct sctp_association *asoc,
				   const union sctp_subtype type,
				   void *arg, struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sk_buff *skb = chunk->skb;
	struct sctp_chunkhdr *ch;
	struct sctp_errhdr *err;
	int ootb_cookie_ack = 0;
	int ootb_shut_ack = 0;
	__u8 *ch_end;

	SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);

	if (asoc && !sctp_vtag_verify(chunk, asoc))
		asoc = NULL;

	ch = (struct sctp_chunkhdr *)chunk->chunk_hdr;
	do {
		/* Report violation if the chunk is less then minimal */
		if (ntohs(ch->length) < sizeof(*ch))
			return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

		/* Report violation if chunk len overflows */
		ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
		if (ch_end > skb_tail_pointer(skb))
			return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

		/* Now that we know we at least have a chunk header,
		 * do things that are type appropriate.
		 */
		if (SCTP_CID_SHUTDOWN_ACK == ch->type)
			ootb_shut_ack = 1;

		/* RFC 2960, Section 3.3.7
		 *   Moreover, under any circumstances, an endpoint that
		 *   receives an ABORT  MUST NOT respond to that ABORT by
		 *   sending an ABORT of its own.
		 */
		if (SCTP_CID_ABORT == ch->type)
			return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

		/* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
		 * or a COOKIE ACK the SCTP Packet should be silently
		 * discarded.
		 */

		if (SCTP_CID_COOKIE_ACK == ch->type)
			ootb_cookie_ack = 1;

		if (SCTP_CID_ERROR == ch->type) {
			sctp_walk_errors(err, ch) {
				if (SCTP_ERROR_STALE_COOKIE == err->cause) {
					ootb_cookie_ack = 1;
					break;
				}
			}
		}

		ch = (struct sctp_chunkhdr *)ch_end;
	} while (ch_end < skb_tail_pointer(skb));

	if (ootb_shut_ack)
		return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
	else if (ootb_cookie_ack)
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	else
		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
}

/*
 * Handle an "Out of the blue" SHUTDOWN ACK.
 *
 * Section: 8.4 5, sctpimpguide 2.41.
 *
 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
 *    respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
 *    When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
 *    packet must fill in the Verification Tag field of the outbound
 *    packet with the Verification Tag received in the SHUTDOWN ACK and
 *    set the T-bit in the Chunk Flags to indicate that the Verification
 *    Tag is reflected.
 *
 * Inputs
 * (endpoint, asoc, type, arg, commands)
 *
 * Outputs
 * (enum sctp_disposition)
 *
 * The return value is the disposition of the chunk.
 */
static enum sctp_disposition sctp_sf_shut_8_4_5(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_packet *packet = NULL;
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *shut;

	packet = sctp_ootb_pkt_new(net, asoc, chunk);
	if (!packet)
		return SCTP_DISPOSITION_NOMEM;

	/* Make an SHUTDOWN_COMPLETE.
	 * The T bit will be set if the asoc is NULL.
	 */
	shut = sctp_make_shutdown_complete(asoc, chunk);
	if (!shut) {
		sctp_ootb_pkt_free(packet);
		return SCTP_DISPOSITION_NOMEM;
	}

	/* Reflect vtag if T-Bit is set */
	if (sctp_test_T_bit(shut))
		packet->vtag = ntohl(chunk->sctp_hdr->vtag);

	/* Set the skb to the belonging sock for accounting.  */
	shut->skb->sk = ep->base.sk;

	sctp_packet_append_chunk(packet, shut);

	sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
			SCTP_PACKET(packet));

	SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);

	/* We need to discard the rest of the packet to prevent
	 * potential boomming attacks from additional bundled chunks.
	 * This is documented in SCTP Threats ID.
	 */
	return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
}

/*
 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
 *
 * Verification Tag:  8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
 *   If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
 *   procedures in section 8.4 SHOULD be followed, in other words it
 *   should be treated as an Out Of The Blue packet.
 *   [This means that we do NOT check the Verification Tag on these
 *   chunks. --piggy ]
 *
 */
enum sctp_disposition sctp_sf_do_8_5_1_E_sa(struct net *net,
					    const struct sctp_endpoint *ep,
					    const struct sctp_association *asoc,
					    const union sctp_subtype type,
					    void *arg,
					    struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!sctp_vtag_verify(chunk, asoc))
		asoc = NULL;

	/* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* Although we do have an association in this case, it corresponds
	 * to a restarted association. So the packet is treated as an OOTB
	 * packet and the state function that handles OOTB SHUTDOWN_ACK is
	 * called with a NULL association.
	 */
	SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);

	return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
}

/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.  */
enum sctp_disposition sctp_sf_do_asconf(struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_paramhdr *err_param = NULL;
	struct sctp_chunk *asconf_ack = NULL;
	struct sctp_chunk *chunk = arg;
	struct sctp_addiphdr *hdr;
	__u32 serial;

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	/* Make sure that the ASCONF ADDIP chunk has a valid length.  */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_addip_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* ADD-IP: Section 4.1.1
	 * This chunk MUST be sent in an authenticated way by using
	 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
	 * is received unauthenticated it MUST be silently discarded as
	 * described in [I-D.ietf-tsvwg-sctp-auth].
	 */
	if (!asoc->peer.asconf_capable ||
	    (!net->sctp.addip_noauth && !chunk->auth))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	hdr = (struct sctp_addiphdr *)chunk->skb->data;
	serial = ntohl(hdr->serial);

	/* Verify the ASCONF chunk before processing it. */
	if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
						  (void *)err_param, commands);

	/* ADDIP 5.2 E1) Compare the value of the serial number to the value
	 * the endpoint stored in a new association variable
	 * 'Peer-Serial-Number'.
	 */
	if (serial == asoc->peer.addip_serial + 1) {
		/* If this is the first instance of ASCONF in the packet,
		 * we can clean our old ASCONF-ACKs.
		 */
		if (!chunk->has_asconf)
			sctp_assoc_clean_asconf_ack_cache(asoc);

		/* ADDIP 5.2 E4) When the Sequence Number matches the next one
		 * expected, process the ASCONF as described below and after
		 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
		 * the response packet and cache a copy of it (in the event it
		 * later needs to be retransmitted).
		 *
		 * Essentially, do V1-V5.
		 */
		asconf_ack = sctp_process_asconf((struct sctp_association *)
						 asoc, chunk);
		if (!asconf_ack)
			return SCTP_DISPOSITION_NOMEM;
	} else if (serial < asoc->peer.addip_serial + 1) {
		/* ADDIP 5.2 E2)
		 * If the value found in the Sequence Number is less than the
		 * ('Peer- Sequence-Number' + 1), simply skip to the next
		 * ASCONF, and include in the outbound response packet
		 * any previously cached ASCONF-ACK response that was
		 * sent and saved that matches the Sequence Number of the
		 * ASCONF.  Note: It is possible that no cached ASCONF-ACK
		 * Chunk exists.  This will occur when an older ASCONF
		 * arrives out of order.  In such a case, the receiver
		 * should skip the ASCONF Chunk and not include ASCONF-ACK
		 * Chunk for that chunk.
		 */
		asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
		if (!asconf_ack)
			return SCTP_DISPOSITION_DISCARD;

		/* Reset the transport so that we select the correct one
		 * this time around.  This is to make sure that we don't
		 * accidentally use a stale transport that's been removed.
		 */
		asconf_ack->transport = NULL;
	} else {
		/* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
		 * it must be either a stale packet or from an attacker.
		 */
		return SCTP_DISPOSITION_DISCARD;
	}

	/* ADDIP 5.2 E6)  The destination address of the SCTP packet
	 * containing the ASCONF-ACK Chunks MUST be the source address of
	 * the SCTP packet that held the ASCONF Chunks.
	 *
	 * To do this properly, we'll set the destination address of the chunk
	 * and at the transmit time, will try look up the transport to use.
	 * Since ASCONFs may be bundled, the correct transport may not be
	 * created until we process the entire packet, thus this workaround.
	 */
	asconf_ack->dest = chunk->source;
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
	if (asoc->new_transport) {
		sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
		((struct sctp_association *)asoc)->new_transport = NULL;
	}

	return SCTP_DISPOSITION_CONSUME;
}

static enum sctp_disposition sctp_send_next_asconf(
					struct net *net,
					const struct sctp_endpoint *ep,
					struct sctp_association *asoc,
					const union sctp_subtype type,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *asconf;
	struct list_head *entry;

	if (list_empty(&asoc->addip_chunk_list))
		return SCTP_DISPOSITION_CONSUME;

	entry = asoc->addip_chunk_list.next;
	asconf = list_entry(entry, struct sctp_chunk, list);

	list_del_init(entry);
	sctp_chunk_hold(asconf);
	asoc->addip_last_asconf = asconf;

	return sctp_sf_do_prm_asconf(net, ep, asoc, type, asconf, commands);
}

/*
 * ADDIP Section 4.3 General rules for address manipulation
 * When building TLV parameters for the ASCONF Chunk that will add or
 * delete IP addresses the D0 to D13 rules should be applied:
 */
enum sctp_disposition sctp_sf_do_asconf_ack(struct net *net,
					    const struct sctp_endpoint *ep,
					    const struct sctp_association *asoc,
					    const union sctp_subtype type,
					    void *arg,
					    struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
	struct sctp_paramhdr *err_param = NULL;
	struct sctp_chunk *asconf_ack = arg;
	struct sctp_addiphdr *addip_hdr;
	__u32 sent_serial, rcvd_serial;
	struct sctp_chunk *abort;

	if (!sctp_vtag_verify(asconf_ack, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	/* Make sure that the ADDIP chunk has a valid length.  */
	if (!sctp_chunk_length_valid(asconf_ack,
				     sizeof(struct sctp_addip_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	/* ADD-IP, Section 4.1.2:
	 * This chunk MUST be sent in an authenticated way by using
	 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
	 * is received unauthenticated it MUST be silently discarded as
	 * described in [I-D.ietf-tsvwg-sctp-auth].
	 */
	if (!asoc->peer.asconf_capable ||
	    (!net->sctp.addip_noauth && !asconf_ack->auth))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	addip_hdr = (struct sctp_addiphdr *)asconf_ack->skb->data;
	rcvd_serial = ntohl(addip_hdr->serial);

	/* Verify the ASCONF-ACK chunk before processing it. */
	if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
			   (void *)err_param, commands);

	if (last_asconf) {
		addip_hdr = (struct sctp_addiphdr *)last_asconf->subh.addip_hdr;
		sent_serial = ntohl(addip_hdr->serial);
	} else {
		sent_serial = asoc->addip_serial - 1;
	}

	/* D0) If an endpoint receives an ASCONF-ACK that is greater than or
	 * equal to the next serial number to be used but no ASCONF chunk is
	 * outstanding the endpoint MUST ABORT the association. Note that a
	 * sequence number is greater than if it is no more than 2^^31-1
	 * larger than the current sequence number (using serial arithmetic).
	 */
	if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
	    !(asoc->addip_last_asconf)) {
		abort = sctp_make_abort(asoc, asconf_ack,
					sizeof(struct sctp_errhdr));
		if (abort) {
			sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(abort));
		}
		/* We are going to ABORT, so we might as well stop
		 * processing the rest of the chunks in the packet.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
		sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ECONNABORTED));
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_DISPOSITION_ABORT;
	}

	if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));

		if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
					     asconf_ack))
			return sctp_send_next_asconf(net, ep,
					(struct sctp_association *)asoc,
							type, commands);

		abort = sctp_make_abort(asoc, asconf_ack,
					sizeof(struct sctp_errhdr));
		if (abort) {
			sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(abort));
		}
		/* We are going to ABORT, so we might as well stop
		 * processing the rest of the chunks in the packet.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ECONNABORTED));
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_DISPOSITION_ABORT;
	}

	return SCTP_DISPOSITION_DISCARD;
}

/* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */
enum sctp_disposition sctp_sf_do_reconf(struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_paramhdr *err_param = NULL;
	struct sctp_chunk *chunk = arg;
	struct sctp_reconf_chunk *hdr;
	union sctp_params param;

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	/* Make sure that the RECONF chunk has a valid length.  */
	if (!sctp_chunk_length_valid(chunk, sizeof(*hdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	if (!sctp_verify_reconf(asoc, chunk, &err_param))
		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
						  (void *)err_param, commands);

	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
	sctp_walk_params(param, hdr, params) {
		struct sctp_chunk *reply = NULL;
		struct sctp_ulpevent *ev = NULL;

		if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST)
			reply = sctp_process_strreset_outreq(
				(struct sctp_association *)asoc, param, &ev);
		else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST)
			reply = sctp_process_strreset_inreq(
				(struct sctp_association *)asoc, param, &ev);
		else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST)
			reply = sctp_process_strreset_tsnreq(
				(struct sctp_association *)asoc, param, &ev);
		else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS)
			reply = sctp_process_strreset_addstrm_out(
				(struct sctp_association *)asoc, param, &ev);
		else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS)
			reply = sctp_process_strreset_addstrm_in(
				(struct sctp_association *)asoc, param, &ev);
		else if (param.p->type == SCTP_PARAM_RESET_RESPONSE)
			reply = sctp_process_strreset_resp(
				(struct sctp_association *)asoc, param, &ev);

		if (ev)
			sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
					SCTP_ULPEVENT(ev));

		if (reply)
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(reply));
	}

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
 *
 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
 * its cumulative TSN point to the value carried in the FORWARD TSN
 * chunk, and then MUST further advance its cumulative TSN point locally
 * if possible.
 * After the above processing, the data receiver MUST stop reporting any
 * missing TSNs earlier than or equal to the new cumulative TSN point.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  const union sctp_subtype type,
					  void *arg,
					  struct sctp_cmd_seq *commands)
{
	struct sctp_fwdtsn_hdr *fwdtsn_hdr;
	struct sctp_chunk *chunk = arg;
	__u16 len;
	__u32 tsn;

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	if (!asoc->peer.prsctp_capable)
		return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);

	/* Make sure that the FORWARD_TSN chunk has valid length.  */
	if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
	chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
	len = ntohs(chunk->chunk_hdr->length);
	len -= sizeof(struct sctp_chunkhdr);
	skb_pull(chunk->skb, len);

	tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
	pr_debug("%s: TSN 0x%x\n", __func__, tsn);

	/* The TSN is too high--silently discard the chunk and count on it
	 * getting retransmitted later.
	 */
	if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
		goto discard_noforce;

	if (!asoc->stream.si->validate_ftsn(chunk))
		goto discard_noforce;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
	if (len > sctp_ftsnhdr_len(&asoc->stream))
		sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
				SCTP_CHUNK(chunk));

	/* Count this as receiving DATA. */
	if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
	}

	/* FIXME: For now send a SACK, but DATA processing may
	 * send another.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());

	return SCTP_DISPOSITION_CONSUME;

discard_noforce:
	return SCTP_DISPOSITION_DISCARD;
}

enum sctp_disposition sctp_sf_eat_fwd_tsn_fast(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_fwdtsn_hdr *fwdtsn_hdr;
	struct sctp_chunk *chunk = arg;
	__u16 len;
	__u32 tsn;

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	if (!asoc->peer.prsctp_capable)
		return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);

	/* Make sure that the FORWARD_TSN chunk has a valid length.  */
	if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
	chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
	len = ntohs(chunk->chunk_hdr->length);
	len -= sizeof(struct sctp_chunkhdr);
	skb_pull(chunk->skb, len);

	tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
	pr_debug("%s: TSN 0x%x\n", __func__, tsn);

	/* The TSN is too high--silently discard the chunk and count on it
	 * getting retransmitted later.
	 */
	if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
		goto gen_shutdown;

	if (!asoc->stream.si->validate_ftsn(chunk))
		goto gen_shutdown;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
	if (len > sctp_ftsnhdr_len(&asoc->stream))
		sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
				SCTP_CHUNK(chunk));

	/* Go a head and force a SACK, since we are shutting down. */
gen_shutdown:
	/* Implementor's Guide.
	 *
	 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
	 * respond to each received packet containing one or more DATA chunk(s)
	 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * SCTP-AUTH Section 6.3 Receiving authenticated chunks
 *
 *    The receiver MUST use the HMAC algorithm indicated in the HMAC
 *    Identifier field.  If this algorithm was not specified by the
 *    receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
 *    during association setup, the AUTH chunk and all chunks after it MUST
 *    be discarded and an ERROR chunk SHOULD be sent with the error cause
 *    defined in Section 4.1.
 *
 *    If an endpoint with no shared key receives a Shared Key Identifier
 *    other than 0, it MUST silently discard all authenticated chunks.  If
 *    the endpoint has at least one endpoint pair shared key for the peer,
 *    it MUST use the key specified by the Shared Key Identifier if a
 *    key has been configured for that Shared Key Identifier.  If no
 *    endpoint pair shared key has been configured for that Shared Key
 *    Identifier, all authenticated chunks MUST be silently discarded.
 *
 * Verification Tag:  8.5 Verification Tag [Normal verification]
 *
 * The return value is the disposition of the chunk.
 */
static enum sctp_ierror sctp_sf_authenticate(
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk)
{
	struct sctp_shared_key *sh_key = NULL;
	struct sctp_authhdr *auth_hdr;
	__u8 *save_digest, *digest;
	struct sctp_hmac *hmac;
	unsigned int sig_len;
	__u16 key_id;

	/* Pull in the auth header, so we can do some more verification */
	auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
	chunk->subh.auth_hdr = auth_hdr;
	skb_pull(chunk->skb, sizeof(*auth_hdr));

	/* Make sure that we support the HMAC algorithm from the auth
	 * chunk.
	 */
	if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
		return SCTP_IERROR_AUTH_BAD_HMAC;

	/* Make sure that the provided shared key identifier has been
	 * configured
	 */
	key_id = ntohs(auth_hdr->shkey_id);
	if (key_id != asoc->active_key_id) {
		sh_key = sctp_auth_get_shkey(asoc, key_id);
		if (!sh_key)
			return SCTP_IERROR_AUTH_BAD_KEYID;
	}

	/* Make sure that the length of the signature matches what
	 * we expect.
	 */
	sig_len = ntohs(chunk->chunk_hdr->length) -
		  sizeof(struct sctp_auth_chunk);
	hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
	if (sig_len != hmac->hmac_len)
		return SCTP_IERROR_PROTO_VIOLATION;

	/* Now that we've done validation checks, we can compute and
	 * verify the hmac.  The steps involved are:
	 *  1. Save the digest from the chunk.
	 *  2. Zero out the digest in the chunk.
	 *  3. Compute the new digest
	 *  4. Compare saved and new digests.
	 */
	digest = auth_hdr->hmac;
	skb_pull(chunk->skb, sig_len);

	save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
	if (!save_digest)
		goto nomem;

	memset(digest, 0, sig_len);

	sctp_auth_calculate_hmac(asoc, chunk->skb,
				 (struct sctp_auth_chunk *)chunk->chunk_hdr,
				 sh_key, GFP_ATOMIC);

	/* Discard the packet if the digests do not match */
	if (memcmp(save_digest, digest, sig_len)) {
		kfree(save_digest);
		return SCTP_IERROR_BAD_SIG;
	}

	kfree(save_digest);
	chunk->auth = 1;

	return SCTP_IERROR_NO_ERROR;
nomem:
	return SCTP_IERROR_NOMEM;
}

enum sctp_disposition sctp_sf_eat_auth(struct net *net,
				       const struct sctp_endpoint *ep,
				       const struct sctp_association *asoc,
				       const union sctp_subtype type,
				       void *arg, struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_authhdr *auth_hdr;
	struct sctp_chunk *err_chunk;
	enum sctp_ierror error;

	/* Make sure that the peer has AUTH capable */
	if (!asoc->peer.auth_capable)
		return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);

	if (!sctp_vtag_verify(chunk, asoc)) {
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
				SCTP_NULL());
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	}

	/* Make sure that the AUTH chunk has valid length.  */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
	error = sctp_sf_authenticate(asoc, chunk);
	switch (error) {
	case SCTP_IERROR_AUTH_BAD_HMAC:
		/* Generate the ERROR chunk and discard the rest
		 * of the packet
		 */
		err_chunk = sctp_make_op_error(asoc, chunk,
					       SCTP_ERROR_UNSUP_HMAC,
					       &auth_hdr->hmac_id,
					       sizeof(__u16), 0);
		if (err_chunk) {
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(err_chunk));
		}
		fallthrough;
	case SCTP_IERROR_AUTH_BAD_KEYID:
	case SCTP_IERROR_BAD_SIG:
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	case SCTP_IERROR_PROTO_VIOLATION:
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	case SCTP_IERROR_NOMEM:
		return SCTP_DISPOSITION_NOMEM;

	default:			/* Prevent gcc warnings */
		break;
	}

	if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
		struct sctp_ulpevent *ev;

		ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
				    SCTP_AUTH_NEW_KEY, GFP_ATOMIC);

		if (!ev)
			return -ENOMEM;

		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
				SCTP_ULPEVENT(ev));
	}

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Process an unknown chunk.
 *
 * Section: 3.2. Also, 2.1 in the implementor's guide.
 *
 * Chunk Types are encoded such that the highest-order two bits specify
 * the action that must be taken if the processing endpoint does not
 * recognize the Chunk Type.
 *
 * 00 - Stop processing this SCTP packet and discard it, do not process
 *      any further chunks within it.
 *
 * 01 - Stop processing this SCTP packet and discard it, do not process
 *      any further chunks within it, and report the unrecognized
 *      chunk in an 'Unrecognized Chunk Type'.
 *
 * 10 - Skip this chunk and continue processing.
 *
 * 11 - Skip this chunk and continue processing, but report in an ERROR
 *      Chunk using the 'Unrecognized Chunk Type' cause of error.
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_unk_chunk(struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *unk_chunk = arg;
	struct sctp_chunk *err_chunk;
	struct sctp_chunkhdr *hdr;

	pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);

	if (!sctp_vtag_verify(unk_chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the chunk has a valid length.
	 * Since we don't know the chunk type, we use a general
	 * chunkhdr structure to make a comparison.
	 */
	if (!sctp_chunk_length_valid(unk_chunk, sizeof(*hdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	switch (type.chunk & SCTP_CID_ACTION_MASK) {
	case SCTP_CID_ACTION_DISCARD:
		/* Discard the packet.  */
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
	case SCTP_CID_ACTION_DISCARD_ERR:
		/* Generate an ERROR chunk as response. */
		hdr = unk_chunk->chunk_hdr;
		err_chunk = sctp_make_op_error(asoc, unk_chunk,
					       SCTP_ERROR_UNKNOWN_CHUNK, hdr,
					       SCTP_PAD4(ntohs(hdr->length)),
					       0);
		if (err_chunk) {
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(err_chunk));
		}

		/* Discard the packet.  */
		sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
		return SCTP_DISPOSITION_CONSUME;
	case SCTP_CID_ACTION_SKIP:
		/* Skip the chunk.  */
		return SCTP_DISPOSITION_DISCARD;
	case SCTP_CID_ACTION_SKIP_ERR:
		/* Generate an ERROR chunk as response. */
		hdr = unk_chunk->chunk_hdr;
		err_chunk = sctp_make_op_error(asoc, unk_chunk,
					       SCTP_ERROR_UNKNOWN_CHUNK, hdr,
					       SCTP_PAD4(ntohs(hdr->length)),
					       0);
		if (err_chunk) {
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(err_chunk));
		}
		/* Skip the chunk.  */
		return SCTP_DISPOSITION_CONSUME;
	default:
		break;
	}

	return SCTP_DISPOSITION_DISCARD;
}

/*
 * Discard the chunk.
 *
 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
 * [Too numerous to mention...]
 * Verification Tag: No verification needed.
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_discard_chunk(struct net *net,
					    const struct sctp_endpoint *ep,
					    const struct sctp_association *asoc,
					    const union sctp_subtype type,
					    void *arg,
					    struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (asoc && !sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the chunk has a valid length.
	 * Since we don't know the chunk type, we use a general
	 * chunkhdr structure to make a comparison.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);

	return SCTP_DISPOSITION_DISCARD;
}

/*
 * Discard the whole packet.
 *
 * Section: 8.4 2)
 *
 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
 *    silently discard the OOTB packet and take no further action.
 *
 * Verification Tag: No verification necessary
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_pdiscard(struct net *net,
				       const struct sctp_endpoint *ep,
				       const struct sctp_association *asoc,
				       const union sctp_subtype type,
				       void *arg, struct sctp_cmd_seq *commands)
{
	SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
	sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());

	return SCTP_DISPOSITION_CONSUME;
}


/*
 * The other end is violating protocol.
 *
 * Section: Not specified
 * Verification Tag: Not specified
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (asoc, reply_msg, msg_up, timers, counters)
 *
 * We simply tag the chunk as a violation.  The state machine will log
 * the violation and continue.
 */
enum sctp_disposition sctp_sf_violation(struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!sctp_vtag_verify(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the chunk has a valid length. */
	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
						  commands);

	return SCTP_DISPOSITION_VIOLATION;
}

/*
 * Common function to handle a protocol violation.
 */
static enum sctp_disposition sctp_sf_abort_violation(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					void *arg,
					struct sctp_cmd_seq *commands,
					const __u8 *payload,
					const size_t paylen)
{
	struct sctp_packet *packet = NULL;
	struct sctp_chunk *chunk =  arg;
	struct sctp_chunk *abort = NULL;

	/* SCTP-AUTH, Section 6.3:
	 *    It should be noted that if the receiver wants to tear
	 *    down an association in an authenticated way only, the
	 *    handling of malformed packets should not result in
	 *    tearing down the association.
	 *
	 * This means that if we only want to abort associations
	 * in an authenticated way (i.e AUTH+ABORT), then we
	 * can't destroy this association just because the packet
	 * was malformed.
	 */
	if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
		goto discard;

	/* Make the abort chunk. */
	abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
	if (!abort)
		goto nomem;

	if (asoc) {
		/* Treat INIT-ACK as a special case during COOKIE-WAIT. */
		if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
		    !asoc->peer.i.init_tag) {
			struct sctp_initack_chunk *initack;

			initack = (struct sctp_initack_chunk *)chunk->chunk_hdr;
			if (!sctp_chunk_length_valid(chunk, sizeof(*initack)))
				abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
			else {
				unsigned int inittag;

				inittag = ntohl(initack->init_hdr.init_tag);
				sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
						SCTP_U32(inittag));
			}
		}

		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
		SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);

		if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
			sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
			sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
					SCTP_ERROR(ECONNREFUSED));
			sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
					SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
		} else {
			sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
					SCTP_ERROR(ECONNABORTED));
			sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
					SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
			SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		}
	} else {
		packet = sctp_ootb_pkt_new(net, asoc, chunk);

		if (!packet)
			goto nomem_pkt;

		if (sctp_test_T_bit(abort))
			packet->vtag = ntohl(chunk->sctp_hdr->vtag);

		abort->skb->sk = ep->base.sk;

		sctp_packet_append_chunk(packet, abort);

		sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
			SCTP_PACKET(packet));

		SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
	}

	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);

discard:
	sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
	return SCTP_DISPOSITION_ABORT;

nomem_pkt:
	sctp_chunk_free(abort);
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Handle a protocol violation when the chunk length is invalid.
 * "Invalid" length is identified as smaller than the minimal length a
 * given chunk can be.  For example, a SACK chunk has invalid length
 * if its length is set to be smaller than the size of struct sctp_sack_chunk.
 *
 * We inform the other end by sending an ABORT with a Protocol Violation
 * error code.
 *
 * Section: Not specified
 * Verification Tag:  Nothing to do
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * Outputs
 * (reply_msg, msg_up, counters)
 *
 * Generate an  ABORT chunk and terminate the association.
 */
static enum sctp_disposition sctp_sf_violation_chunklen(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	static const char err_str[] = "The following chunk had invalid length:";

	return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
				       sizeof(err_str));
}

/*
 * Handle a protocol violation when the parameter length is invalid.
 * If the length is smaller than the minimum length of a given parameter,
 * or accumulated length in multi parameters exceeds the end of the chunk,
 * the length is considered as invalid.
 */
static enum sctp_disposition sctp_sf_violation_paramlen(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg, void *ext,
					struct sctp_cmd_seq *commands)
{
	struct sctp_paramhdr *param = ext;
	struct sctp_chunk *abort = NULL;
	struct sctp_chunk *chunk = arg;

	if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
		goto discard;

	/* Make the abort chunk. */
	abort = sctp_make_violation_paramlen(asoc, chunk, param);
	if (!abort)
		goto nomem;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
	SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);

	sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
			SCTP_ERROR(ECONNABORTED));
	sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
			SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);

discard:
	sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
	return SCTP_DISPOSITION_ABORT;
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/* Handle a protocol violation when the peer trying to advance the
 * cumulative tsn ack to a point beyond the max tsn currently sent.
 *
 * We inform the other end by sending an ABORT with a Protocol Violation
 * error code.
 */
static enum sctp_disposition sctp_sf_violation_ctsn(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";

	return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
				       sizeof(err_str));
}

/* Handle protocol violation of an invalid chunk bundling.  For example,
 * when we have an association and we receive bundled INIT-ACK, or
 * SHUTDOWN-COMPLETE, our peer is clearly violating the "MUST NOT bundle"
 * statement from the specs.  Additionally, there might be an attacker
 * on the path and we may not want to continue this communication.
 */
static enum sctp_disposition sctp_sf_violation_chunk(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	static const char err_str[] = "The following chunk violates protocol:";

	return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
				       sizeof(err_str));
}
/***************************************************************************
 * These are the state functions for handling primitive (Section 10) events.
 ***************************************************************************/
/*
 * sctp_sf_do_prm_asoc
 *
 * Section: 10.1 ULP-to-SCTP
 * B) Associate
 *
 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
 * outbound stream count)
 * -> association id [,destination transport addr list] [,outbound stream
 * count]
 *
 * This primitive allows the upper layer to initiate an association to a
 * specific peer endpoint.
 *
 * The peer endpoint shall be specified by one of the transport addresses
 * which defines the endpoint (see Section 1.4).  If the local SCTP
 * instance has not been initialized, the ASSOCIATE is considered an
 * error.
 * [This is not relevant for the kernel implementation since we do all
 * initialization at boot time.  It we hadn't initialized we wouldn't
 * get anywhere near this code.]
 *
 * An association id, which is a local handle to the SCTP association,
 * will be returned on successful establishment of the association. If
 * SCTP is not able to open an SCTP association with the peer endpoint,
 * an error is returned.
 * [In the kernel implementation, the struct sctp_association needs to
 * be created BEFORE causing this primitive to run.]
 *
 * Other association parameters may be returned, including the
 * complete destination transport addresses of the peer as well as the
 * outbound stream count of the local endpoint. One of the transport
 * address from the returned destination addresses will be selected by
 * the local endpoint as default primary path for sending SCTP packets
 * to this peer.  The returned "destination transport addr list" can
 * be used by the ULP to change the default primary path or to force
 * sending a packet to a specific transport address.  [All of this
 * stuff happens when the INIT ACK arrives.  This is a NON-BLOCKING
 * function.]
 *
 * Mandatory attributes:
 *
 * o local SCTP instance name - obtained from the INITIALIZE operation.
 *   [This is the argument asoc.]
 * o destination transport addr - specified as one of the transport
 * addresses of the peer endpoint with which the association is to be
 * established.
 *  [This is asoc->peer.active_path.]
 * o outbound stream count - the number of outbound streams the ULP
 * would like to open towards this peer endpoint.
 * [BUG: This is not currently implemented.]
 * Optional attributes:
 *
 * None.
 *
 * The return value is a disposition.
 */
enum sctp_disposition sctp_sf_do_prm_asoc(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  const union sctp_subtype type,
					  void *arg,
					  struct sctp_cmd_seq *commands)
{
	struct sctp_association *my_asoc;
	struct sctp_chunk *repl;

	/* The comment below says that we enter COOKIE-WAIT AFTER
	 * sending the INIT, but that doesn't actually work in our
	 * implementation...
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_COOKIE_WAIT));

	/* RFC 2960 5.1 Normal Establishment of an Association
	 *
	 * A) "A" first sends an INIT chunk to "Z".  In the INIT, "A"
	 * must provide its Verification Tag (Tag_A) in the Initiate
	 * Tag field.  Tag_A SHOULD be a random number in the range of
	 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
	 */

	repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
	if (!repl)
		goto nomem;

	/* Choose transport for INIT. */
	sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
			SCTP_CHUNK(repl));

	/* Cast away the const modifier, as we want to just
	 * rerun it through as a sideffect.
	 */
	my_asoc = (struct sctp_association *)asoc;
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));

	/* After sending the INIT, "A" starts the T1-init timer and
	 * enters the COOKIE-WAIT state.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Process the SEND primitive.
 *
 * Section: 10.1 ULP-to-SCTP
 * E) Send
 *
 * Format: SEND(association id, buffer address, byte count [,context]
 *         [,stream id] [,life time] [,destination transport address]
 *         [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
 * -> result
 *
 * This is the main method to send user data via SCTP.
 *
 * Mandatory attributes:
 *
 *  o association id - local handle to the SCTP association
 *
 *  o buffer address - the location where the user message to be
 *    transmitted is stored;
 *
 *  o byte count - The size of the user data in number of bytes;
 *
 * Optional attributes:
 *
 *  o context - an optional 32 bit integer that will be carried in the
 *    sending failure notification to the ULP if the transportation of
 *    this User Message fails.
 *
 *  o stream id - to indicate which stream to send the data on. If not
 *    specified, stream 0 will be used.
 *
 *  o life time - specifies the life time of the user data. The user data
 *    will not be sent by SCTP after the life time expires. This
 *    parameter can be used to avoid efforts to transmit stale
 *    user messages. SCTP notifies the ULP if the data cannot be
 *    initiated to transport (i.e. sent to the destination via SCTP's
 *    send primitive) within the life time variable. However, the
 *    user data will be transmitted if SCTP has attempted to transmit a
 *    chunk before the life time expired.
 *
 *  o destination transport address - specified as one of the destination
 *    transport addresses of the peer endpoint to which this packet
 *    should be sent. Whenever possible, SCTP should use this destination
 *    transport address for sending the packets, instead of the current
 *    primary path.
 *
 *  o unorder flag - this flag, if present, indicates that the user
 *    would like the data delivered in an unordered fashion to the peer
 *    (i.e., the U flag is set to 1 on all DATA chunks carrying this
 *    message).
 *
 *  o no-bundle flag - instructs SCTP not to bundle this user data with
 *    other outbound DATA chunks. SCTP MAY still bundle even when
 *    this flag is present, when faced with network congestion.
 *
 *  o payload protocol-id - A 32 bit unsigned integer that is to be
 *    passed to the peer indicating the type of payload protocol data
 *    being transmitted. This value is passed as opaque data by SCTP.
 *
 * The return value is the disposition.
 */
enum sctp_disposition sctp_sf_do_prm_send(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  const union sctp_subtype type,
					  void *arg,
					  struct sctp_cmd_seq *commands)
{
	struct sctp_datamsg *msg = arg;

	sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Process the SHUTDOWN primitive.
 *
 * Section: 10.1:
 * C) Shutdown
 *
 * Format: SHUTDOWN(association id)
 * -> result
 *
 * Gracefully closes an association. Any locally queued user data
 * will be delivered to the peer. The association will be terminated only
 * after the peer acknowledges all the SCTP packets sent.  A success code
 * will be returned on successful termination of the association. If
 * attempting to terminate the association results in a failure, an error
 * code shall be returned.
 *
 * Mandatory attributes:
 *
 *  o association id - local handle to the SCTP association
 *
 * Optional attributes:
 *
 * None.
 *
 * The return value is the disposition.
 */
enum sctp_disposition sctp_sf_do_9_2_prm_shutdown(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	enum sctp_disposition disposition;

	/* From 9.2 Shutdown of an Association
	 * Upon receipt of the SHUTDOWN primitive from its upper
	 * layer, the endpoint enters SHUTDOWN-PENDING state and
	 * remains there until all outstanding data has been
	 * acknowledged by its peer. The endpoint accepts no new data
	 * from its upper layer, but retransmits data to the far end
	 * if necessary to fill gaps.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));

	disposition = SCTP_DISPOSITION_CONSUME;
	if (sctp_outq_is_empty(&asoc->outqueue)) {
		disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
							    arg, commands);
	}

	return disposition;
}

/*
 * Process the ABORT primitive.
 *
 * Section: 10.1:
 * C) Abort
 *
 * Format: Abort(association id [, cause code])
 * -> result
 *
 * Ungracefully closes an association. Any locally queued user data
 * will be discarded and an ABORT chunk is sent to the peer.  A success code
 * will be returned on successful abortion of the association. If
 * attempting to abort the association results in a failure, an error
 * code shall be returned.
 *
 * Mandatory attributes:
 *
 *  o association id - local handle to the SCTP association
 *
 * Optional attributes:
 *
 *  o cause code - reason of the abort to be passed to the peer
 *
 * None.
 *
 * The return value is the disposition.
 */
enum sctp_disposition sctp_sf_do_9_1_prm_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* From 9.1 Abort of an Association
	 * Upon receipt of the ABORT primitive from its upper
	 * layer, the endpoint enters CLOSED state and
	 * discard all outstanding data has been
	 * acknowledged by its peer. The endpoint accepts no new data
	 * from its upper layer, but retransmits data to the far end
	 * if necessary to fill gaps.
	 */
	struct sctp_chunk *abort = arg;

	if (abort)
		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));

	/* Even if we can't send the ABORT due to low memory delete the
	 * TCB.  This is a departure from our typical NOMEM handling.
	 */

	sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
			SCTP_ERROR(ECONNABORTED));
	/* Delete the established association. */
	sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
			SCTP_PERR(SCTP_ERROR_USER_ABORT));

	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);

	return SCTP_DISPOSITION_ABORT;
}

/* We tried an illegal operation on an association which is closed.  */
enum sctp_disposition sctp_sf_error_closed(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
	return SCTP_DISPOSITION_CONSUME;
}

/* We tried an illegal operation on an association which is shutting
 * down.
 */
enum sctp_disposition sctp_sf_error_shutdown(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
			SCTP_ERROR(-ESHUTDOWN));
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * sctp_cookie_wait_prm_shutdown
 *
 * Section: 4 Note: 2
 * Verification Tag:
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explicitly address this issue, but is the route through the
 * state table when someone issues a shutdown while in COOKIE_WAIT state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_cookie_wait_prm_shutdown(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_CLOSED));

	SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);

	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());

	return SCTP_DISPOSITION_DELETE_TCB;
}

/*
 * sctp_cookie_echoed_prm_shutdown
 *
 * Section: 4 Note: 2
 * Verification Tag:
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explicitly address this issue, but is the route through the
 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_cookie_echoed_prm_shutdown(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* There is a single T1 timer, so we should be able to use
	 * common function with the COOKIE-WAIT state.
	 */
	return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
}

/*
 * sctp_sf_cookie_wait_prm_abort
 *
 * Section: 4 Note: 2
 * Verification Tag:
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explicitly address this issue, but is the route through the
 * state table when someone issues an abort while in COOKIE_WAIT state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_cookie_wait_prm_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *abort = arg;

	/* Stop T1-init timer */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));

	if (abort)
		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));

	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_CLOSED));

	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);

	/* Even if we can't send the ABORT due to low memory delete the
	 * TCB.  This is a departure from our typical NOMEM handling.
	 */

	sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
			SCTP_ERROR(ECONNREFUSED));
	/* Delete the established association. */
	sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
			SCTP_PERR(SCTP_ERROR_USER_ABORT));

	return SCTP_DISPOSITION_ABORT;
}

/*
 * sctp_sf_cookie_echoed_prm_abort
 *
 * Section: 4 Note: 3
 * Verification Tag:
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explcitly address this issue, but is the route through the
 * state table when someone issues an abort while in COOKIE_ECHOED state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_cookie_echoed_prm_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* There is a single T1 timer, so we should be able to use
	 * common function with the COOKIE-WAIT state.
	 */
	return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
}

/*
 * sctp_sf_shutdown_pending_prm_abort
 *
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explicitly address this issue, but is the route through the
 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_shutdown_pending_prm_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* Stop the T5-shutdown guard timer.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));

	return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
}

/*
 * sctp_sf_shutdown_sent_prm_abort
 *
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explicitly address this issue, but is the route through the
 * state table when someone issues an abort while in SHUTDOWN-SENT state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_shutdown_sent_prm_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* Stop the T2-shutdown timer.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	/* Stop the T5-shutdown guard timer.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));

	return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
}

/*
 * sctp_sf_cookie_echoed_prm_abort
 *
 * Inputs
 * (endpoint, asoc)
 *
 * The RFC does not explcitly address this issue, but is the route through the
 * state table when someone issues an abort while in COOKIE_ECHOED state.
 *
 * Outputs
 * (timers)
 */
enum sctp_disposition sctp_sf_shutdown_ack_sent_prm_abort(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	/* The same T2 timer, so we should be able to use
	 * common function with the SHUTDOWN-SENT state.
	 */
	return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
}

/*
 * Process the REQUESTHEARTBEAT primitive
 *
 * 10.1 ULP-to-SCTP
 * J) Request Heartbeat
 *
 * Format: REQUESTHEARTBEAT(association id, destination transport address)
 *
 * -> result
 *
 * Instructs the local endpoint to perform a HeartBeat on the specified
 * destination transport address of the given association. The returned
 * result should indicate whether the transmission of the HEARTBEAT
 * chunk to the destination address is successful.
 *
 * Mandatory attributes:
 *
 * o association id - local handle to the SCTP association
 *
 * o destination transport address - the transport address of the
 *   association on which a heartbeat should be issued.
 */
enum sctp_disposition sctp_sf_do_prm_requestheartbeat(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
				      (struct sctp_transport *)arg, commands))
		return SCTP_DISPOSITION_NOMEM;

	/*
	 * RFC 2960 (bis), section 8.3
	 *
	 *    D) Request an on-demand HEARTBEAT on a specific destination
	 *    transport address of a given association.
	 *
	 *    The endpoint should increment the respective error  counter of
	 *    the destination transport address each time a HEARTBEAT is sent
	 *    to that address and not acknowledged within one RTO.
	 *
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
			SCTP_TRANSPORT(arg));
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * ADDIP Section 4.1 ASCONF Chunk Procedures
 * When an endpoint has an ASCONF signaled change to be sent to the
 * remote endpoint it should do A1 to A9
 */
enum sctp_disposition sctp_sf_do_prm_asconf(struct net *net,
					    const struct sctp_endpoint *ep,
					    const struct sctp_association *asoc,
					    const union sctp_subtype type,
					    void *arg,
					    struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
	return SCTP_DISPOSITION_CONSUME;
}

/* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
enum sctp_disposition sctp_sf_do_prm_reconf(struct net *net,
					    const struct sctp_endpoint *ep,
					    const struct sctp_association *asoc,
					    const union sctp_subtype type,
					    void *arg,
					    struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Ignore the primitive event
 *
 * The return value is the disposition of the primitive.
 */
enum sctp_disposition sctp_sf_ignore_primitive(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	pr_debug("%s: primitive type:%d is ignored\n", __func__,
		 type.primitive);

	return SCTP_DISPOSITION_DISCARD;
}

/***************************************************************************
 * These are the state functions for the OTHER events.
 ***************************************************************************/

/*
 * When the SCTP stack has no more user data to send or retransmit, this
 * notification is given to the user. Also, at the time when a user app
 * subscribes to this event, if there is no data to be sent or
 * retransmit, the stack will immediately send up this notification.
 */
enum sctp_disposition sctp_sf_do_no_pending_tsn(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_ulpevent *event;

	event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
	if (!event)
		return SCTP_DISPOSITION_NOMEM;

	sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Start the shutdown negotiation.
 *
 * From Section 9.2:
 * Once all its outstanding data has been acknowledged, the endpoint
 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
 * TSN Ack field the last sequential TSN it has received from the peer.
 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
 * with the updated last sequential TSN received from its peer.
 *
 * The return value is the disposition.
 */
enum sctp_disposition sctp_sf_do_9_2_start_shutdown(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *reply;

	/* Once all its outstanding data has been acknowledged, the
	 * endpoint shall send a SHUTDOWN chunk to its peer including
	 * in the Cumulative TSN Ack field the last sequential TSN it
	 * has received from the peer.
	 */
	reply = sctp_make_shutdown(asoc, arg);
	if (!reply)
		goto nomem;

	/* Set the transport for the SHUTDOWN chunk and the timeout for the
	 * T2-shutdown timer.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));

	/* It shall then start the T2-shutdown timer */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	/* RFC 4960 Section 9.2
	 * The sender of the SHUTDOWN MAY also start an overall guard timer
	 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));

	if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));

	/* and enter the SHUTDOWN-SENT state.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));

	/* sctp-implguide 2.10 Issues with Heartbeating and failover
	 *
	 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
	 * or SHUTDOWN-ACK.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));

	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Generate a SHUTDOWN ACK now that everything is SACK'd.
 *
 * From Section 9.2:
 *
 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
 * endpoint must re-send the SHUTDOWN ACK.
 *
 * The return value is the disposition.
 */
enum sctp_disposition sctp_sf_do_9_2_shutdown_ack(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = arg;
	struct sctp_chunk *reply;

	/* There are 2 ways of getting here:
	 *    1) called in response to a SHUTDOWN chunk
	 *    2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
	 *
	 * For the case (2), the arg parameter is set to NULL.  We need
	 * to check that we have a chunk before accessing it's fields.
	 */
	if (chunk) {
		if (!sctp_vtag_verify(chunk, asoc))
			return sctp_sf_pdiscard(net, ep, asoc, type, arg,
						commands);

		/* Make sure that the SHUTDOWN chunk has a valid length. */
		if (!sctp_chunk_length_valid(
				chunk, sizeof(struct sctp_shutdown_chunk)))
			return sctp_sf_violation_chunklen(net, ep, asoc, type,
							  arg, commands);
	}

	/* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
	 * shall send a SHUTDOWN ACK ...
	 */
	reply = sctp_make_shutdown_ack(asoc, chunk);
	if (!reply)
		goto nomem;

	/* Set the transport for the SHUTDOWN ACK chunk and the timeout for
	 * the T2-shutdown timer.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));

	/* and start/restart a T2-shutdown timer of its own, */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));

	if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
				SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));

	/* Enter the SHUTDOWN-ACK-SENT state.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));

	/* sctp-implguide 2.10 Issues with Heartbeating and failover
	 *
	 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
	 * or SHUTDOWN-ACK.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));

	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * Ignore the event defined as other
 *
 * The return value is the disposition of the event.
 */
enum sctp_disposition sctp_sf_ignore_other(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	pr_debug("%s: the event other type:%d is ignored\n",
		 __func__, type.other);

	return SCTP_DISPOSITION_DISCARD;
}

/************************************************************
 * These are the state functions for handling timeout events.
 ************************************************************/

/*
 * RTX Timeout
 *
 * Section: 6.3.3 Handle T3-rtx Expiration
 *
 * Whenever the retransmission timer T3-rtx expires for a destination
 * address, do the following:
 * [See below]
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_do_6_3_3_rtx(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	struct sctp_transport *transport = arg;

	SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);

	if (asoc->overall_error_count >= asoc->max_retrans) {
		if (asoc->peer.zero_window_announced &&
		    asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
			/*
			 * We are here likely because the receiver had its rwnd
			 * closed for a while and we have not been able to
			 * transmit the locally queued data within the maximum
			 * retransmission attempts limit.  Start the T5
			 * shutdown guard timer to give the receiver one last
			 * chance and some additional time to recover before
			 * aborting.
			 */
			sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
		} else {
			sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
					SCTP_ERROR(ETIMEDOUT));
			/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
			sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
					SCTP_PERR(SCTP_ERROR_NO_ERROR));
			SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
			SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
			return SCTP_DISPOSITION_DELETE_TCB;
		}
	}

	/* E1) For the destination address for which the timer
	 * expires, adjust its ssthresh with rules defined in Section
	 * 7.2.3 and set the cwnd <- MTU.
	 */

	/* E2) For the destination address for which the timer
	 * expires, set RTO <- RTO * 2 ("back off the timer").  The
	 * maximum value discussed in rule C7 above (RTO.max) may be
	 * used to provide an upper bound to this doubling operation.
	 */

	/* E3) Determine how many of the earliest (i.e., lowest TSN)
	 * outstanding DATA chunks for the address for which the
	 * T3-rtx has expired will fit into a single packet, subject
	 * to the MTU constraint for the path corresponding to the
	 * destination transport address to which the retransmission
	 * is being sent (this may be different from the address for
	 * which the timer expires [see Section 6.4]).  Call this
	 * value K. Bundle and retransmit those K DATA chunks in a
	 * single packet to the destination endpoint.
	 *
	 * Note: Any DATA chunks that were sent to the address for
	 * which the T3-rtx timer expired but did not fit in one MTU
	 * (rule E3 above), should be marked for retransmission and
	 * sent as soon as cwnd allows (normally when a SACK arrives).
	 */

	/* Do some failure management (Section 8.2). */
	sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));

	/* NB: Rules E4 and F1 are implicit in R1.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * Generate delayed SACK on timeout
 *
 * Section: 6.2  Acknowledgement on Reception of DATA Chunks
 *
 * The guidelines on delayed acknowledgement algorithm specified in
 * Section 4.2 of [RFC2581] SHOULD be followed.  Specifically, an
 * acknowledgement SHOULD be generated for at least every second packet
 * (not every second DATA chunk) received, and SHOULD be generated
 * within 200 ms of the arrival of any unacknowledged DATA chunk.  In
 * some situations it may be beneficial for an SCTP transmitter to be
 * more conservative than the algorithms detailed in this document
 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
 * the following algorithms allow.
 */
enum sctp_disposition sctp_sf_do_6_2_sack(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  const union sctp_subtype type,
					  void *arg,
					  struct sctp_cmd_seq *commands)
{
	SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
	return SCTP_DISPOSITION_CONSUME;
}

/*
 * sctp_sf_t1_init_timer_expire
 *
 * Section: 4 Note: 2
 * Verification Tag:
 * Inputs
 * (endpoint, asoc)
 *
 *  RFC 2960 Section 4 Notes
 *  2) If the T1-init timer expires, the endpoint MUST retransmit INIT
 *     and re-start the T1-init timer without changing state.  This MUST
 *     be repeated up to 'Max.Init.Retransmits' times.  After that, the
 *     endpoint MUST abort the initialization process and report the
 *     error to SCTP user.
 *
 * Outputs
 * (timers, events)
 *
 */
enum sctp_disposition sctp_sf_t1_init_timer_expire(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	int attempts = asoc->init_err_counter + 1;
	struct sctp_chunk *repl = NULL;
	struct sctp_bind_addr *bp;

	pr_debug("%s: timer T1 expired (INIT)\n", __func__);

	SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);

	if (attempts <= asoc->max_init_attempts) {
		bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
		repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
		if (!repl)
			return SCTP_DISPOSITION_NOMEM;

		/* Choose transport for INIT. */
		sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
				SCTP_CHUNK(repl));

		/* Issue a sideeffect to do the needed accounting. */
		sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));

		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
	} else {
		pr_debug("%s: giving up on INIT, attempts:%d "
			 "max_init_attempts:%d\n", __func__, attempts,
			 asoc->max_init_attempts);

		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_ERROR));
		return SCTP_DISPOSITION_DELETE_TCB;
	}

	return SCTP_DISPOSITION_CONSUME;
}

/*
 * sctp_sf_t1_cookie_timer_expire
 *
 * Section: 4 Note: 2
 * Verification Tag:
 * Inputs
 * (endpoint, asoc)
 *
 *  RFC 2960 Section 4 Notes
 *  3) If the T1-cookie timer expires, the endpoint MUST retransmit
 *     COOKIE ECHO and re-start the T1-cookie timer without changing
 *     state.  This MUST be repeated up to 'Max.Init.Retransmits' times.
 *     After that, the endpoint MUST abort the initialization process and
 *     report the error to SCTP user.
 *
 * Outputs
 * (timers, events)
 *
 */
enum sctp_disposition sctp_sf_t1_cookie_timer_expire(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	int attempts = asoc->init_err_counter + 1;
	struct sctp_chunk *repl = NULL;

	pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);

	SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);

	if (attempts <= asoc->max_init_attempts) {
		repl = sctp_make_cookie_echo(asoc, NULL);
		if (!repl)
			return SCTP_DISPOSITION_NOMEM;

		sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
				SCTP_CHUNK(repl));
		/* Issue a sideeffect to do the needed accounting. */
		sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));

		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
	} else {
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_ERROR));
		return SCTP_DISPOSITION_DELETE_TCB;
	}

	return SCTP_DISPOSITION_CONSUME;
}

/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
 * with the updated last sequential TSN received from its peer.
 *
 * An endpoint should limit the number of retransmission of the
 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
 * If this threshold is exceeded the endpoint should destroy the TCB and
 * MUST report the peer endpoint unreachable to the upper layer (and
 * thus the association enters the CLOSED state).  The reception of any
 * packet from its peer (i.e. as the peer sends all of its queued DATA
 * chunks) should clear the endpoint's retransmission count and restart
 * the T2-Shutdown timer,  giving its peer ample opportunity to transmit
 * all of its queued DATA chunks that have not yet been sent.
 */
enum sctp_disposition sctp_sf_t2_timer_expire(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *reply = NULL;

	pr_debug("%s: timer T2 expired\n", __func__);

	SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);

	((struct sctp_association *)asoc)->shutdown_retries++;

	if (asoc->overall_error_count >= asoc->max_retrans) {
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		/* Note:  CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_ERROR));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_DISPOSITION_DELETE_TCB;
	}

	switch (asoc->state) {
	case SCTP_STATE_SHUTDOWN_SENT:
		reply = sctp_make_shutdown(asoc, NULL);
		break;

	case SCTP_STATE_SHUTDOWN_ACK_SENT:
		reply = sctp_make_shutdown_ack(asoc, NULL);
		break;

	default:
		BUG();
		break;
	}

	if (!reply)
		goto nomem;

	/* Do some failure management (Section 8.2).
	 * If we remove the transport an SHUTDOWN was last sent to, don't
	 * do failure management.
	 */
	if (asoc->shutdown_last_sent_to)
		sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
				SCTP_TRANSPORT(asoc->shutdown_last_sent_to));

	/* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
	 * the T2-shutdown timer.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));

	/* Restart the T2-shutdown timer.  */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
	return SCTP_DISPOSITION_CONSUME;

nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/*
 * ADDIP Section 4.1 ASCONF Chunk Procedures
 * If the T4 RTO timer expires the endpoint should do B1 to B5
 */
enum sctp_disposition sctp_sf_t4_timer_expire(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *chunk = asoc->addip_last_asconf;
	struct sctp_transport *transport = chunk->transport;

	SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);

	/* ADDIP 4.1 B1) Increment the error counters and perform path failure
	 * detection on the appropriate destination address as defined in
	 * RFC2960 [5] section 8.1 and 8.2.
	 */
	if (transport)
		sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
				SCTP_TRANSPORT(transport));

	/* Reconfig T4 timer and transport. */
	sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));

	/* ADDIP 4.1 B2) Increment the association error counters and perform
	 * endpoint failure detection on the association as defined in
	 * RFC2960 [5] section 8.1 and 8.2.
	 * association error counter is incremented in SCTP_CMD_STRIKE.
	 */
	if (asoc->overall_error_count >= asoc->max_retrans) {
		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
				SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ETIMEDOUT));
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_ERROR));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_DISPOSITION_ABORT;
	}

	/* ADDIP 4.1 B3) Back-off the destination address RTO value to which
	 * the ASCONF chunk was sent by doubling the RTO timer value.
	 * This is done in SCTP_CMD_STRIKE.
	 */

	/* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
	 * choose an alternate destination address (please refer to RFC2960
	 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
	 * chunk, it MUST be the same (including its serial number) as the last
	 * ASCONF sent.
	 */
	sctp_chunk_hold(asoc->addip_last_asconf);
	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
			SCTP_CHUNK(asoc->addip_last_asconf));

	/* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
	 * destination is selected, then the RTO used will be that of the new
	 * destination address.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
			SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));

	return SCTP_DISPOSITION_CONSUME;
}

/* sctpimpguide-05 Section 2.12.2
 * The sender of the SHUTDOWN MAY also start an overall guard timer
 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
 * At the expiration of this timer the sender SHOULD abort the association
 * by sending an ABORT chunk.
 */
enum sctp_disposition sctp_sf_t5_timer_expire(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	struct sctp_chunk *reply = NULL;

	pr_debug("%s: timer T5 expired\n", __func__);

	SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);

	reply = sctp_make_abort(asoc, NULL, 0);
	if (!reply)
		goto nomem;

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
	sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
			SCTP_ERROR(ETIMEDOUT));
	sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
			SCTP_PERR(SCTP_ERROR_NO_ERROR));

	SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
	SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);

	return SCTP_DISPOSITION_DELETE_TCB;
nomem:
	return SCTP_DISPOSITION_NOMEM;
}

/* Handle expiration of AUTOCLOSE timer.  When the autoclose timer expires,
 * the association is automatically closed by starting the shutdown process.
 * The work that needs to be done is same as when SHUTDOWN is initiated by
 * the user.  So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
 */
enum sctp_disposition sctp_sf_autoclose_timer_expire(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const union sctp_subtype type,
					void *arg,
					struct sctp_cmd_seq *commands)
{
	enum sctp_disposition disposition;

	SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);

	/* From 9.2 Shutdown of an Association
	 * Upon receipt of the SHUTDOWN primitive from its upper
	 * layer, the endpoint enters SHUTDOWN-PENDING state and
	 * remains there until all outstanding data has been
	 * acknowledged by its peer. The endpoint accepts no new data
	 * from its upper layer, but retransmits data to the far end
	 * if necessary to fill gaps.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
			SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));

	disposition = SCTP_DISPOSITION_CONSUME;
	if (sctp_outq_is_empty(&asoc->outqueue)) {
		disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
							    NULL, commands);
	}

	return disposition;
}

/*****************************************************************************
 * These are sa state functions which could apply to all types of events.
 ****************************************************************************/

/*
 * This table entry is not implemented.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_not_impl(struct net *net,
				       const struct sctp_endpoint *ep,
				       const struct sctp_association *asoc,
				       const union sctp_subtype type,
				       void *arg, struct sctp_cmd_seq *commands)
{
	return SCTP_DISPOSITION_NOT_IMPL;
}

/*
 * This table entry represents a bug.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_bug(struct net *net,
				  const struct sctp_endpoint *ep,
				  const struct sctp_association *asoc,
				  const union sctp_subtype type,
				  void *arg, struct sctp_cmd_seq *commands)
{
	return SCTP_DISPOSITION_BUG;
}

/*
 * This table entry represents the firing of a timer in the wrong state.
 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
 * when the association is in the wrong state.   This event should
 * be ignored, so as to prevent any rearming of the timer.
 *
 * Inputs
 * (endpoint, asoc, chunk)
 *
 * The return value is the disposition of the chunk.
 */
enum sctp_disposition sctp_sf_timer_ignore(struct net *net,
					   const struct sctp_endpoint *ep,
					   const struct sctp_association *asoc,
					   const union sctp_subtype type,
					   void *arg,
					   struct sctp_cmd_seq *commands)
{
	pr_debug("%s: timer %d ignored\n", __func__, type.chunk);

	return SCTP_DISPOSITION_CONSUME;
}

/********************************************************************
 * 2nd Level Abstractions
 ********************************************************************/

/* Pull the SACK chunk based on the SACK header. */
static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
{
	struct sctp_sackhdr *sack;
	__u16 num_dup_tsns;
	unsigned int len;
	__u16 num_blocks;

	/* Protect ourselves from reading too far into
	 * the skb from a bogus sender.
	 */
	sack = (struct sctp_sackhdr *) chunk->skb->data;

	num_blocks = ntohs(sack->num_gap_ack_blocks);
	num_dup_tsns = ntohs(sack->num_dup_tsns);
	len = sizeof(struct sctp_sackhdr);
	len += (num_blocks + num_dup_tsns) * sizeof(__u32);
	if (len > chunk->skb->len)
		return NULL;

	skb_pull(chunk->skb, len);

	return sack;
}

/* Create an ABORT packet to be sent as a response, with the specified
 * error causes.
 */
static struct sctp_packet *sctp_abort_pkt_new(
					struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk,
					const void *payload, size_t paylen)
{
	struct sctp_packet *packet;
	struct sctp_chunk *abort;

	packet = sctp_ootb_pkt_new(net, asoc, chunk);

	if (packet) {
		/* Make an ABORT.
		 * The T bit will be set if the asoc is NULL.
		 */
		abort = sctp_make_abort(asoc, chunk, paylen);
		if (!abort) {
			sctp_ootb_pkt_free(packet);
			return NULL;
		}

		/* Reflect vtag if T-Bit is set */
		if (sctp_test_T_bit(abort))
			packet->vtag = ntohl(chunk->sctp_hdr->vtag);

		/* Add specified error causes, i.e., payload, to the
		 * end of the chunk.
		 */
		sctp_addto_chunk(abort, paylen, payload);

		/* Set the skb to the belonging sock for accounting.  */
		abort->skb->sk = ep->base.sk;

		sctp_packet_append_chunk(packet, abort);

	}

	return packet;
}

/* Allocate a packet for responding in the OOTB conditions.  */
static struct sctp_packet *sctp_ootb_pkt_new(
					struct net *net,
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
{
	struct sctp_transport *transport;
	struct sctp_packet *packet;
	__u16 sport, dport;
	__u32 vtag;

	/* Get the source and destination port from the inbound packet.  */
	sport = ntohs(chunk->sctp_hdr->dest);
	dport = ntohs(chunk->sctp_hdr->source);

	/* The V-tag is going to be the same as the inbound packet if no
	 * association exists, otherwise, use the peer's vtag.
	 */
	if (asoc) {
		/* Special case the INIT-ACK as there is no peer's vtag
		 * yet.
		 */
		switch (chunk->chunk_hdr->type) {
		case SCTP_CID_INIT:
		case SCTP_CID_INIT_ACK:
		{
			struct sctp_initack_chunk *initack;

			initack = (struct sctp_initack_chunk *)chunk->chunk_hdr;
			vtag = ntohl(initack->init_hdr.init_tag);
			break;
		}
		default:
			vtag = asoc->peer.i.init_tag;
			break;
		}
	} else {
		/* Special case the INIT and stale COOKIE_ECHO as there is no
		 * vtag yet.
		 */
		switch (chunk->chunk_hdr->type) {
		case SCTP_CID_INIT:
		{
			struct sctp_init_chunk *init;

			init = (struct sctp_init_chunk *)chunk->chunk_hdr;
			vtag = ntohl(init->init_hdr.init_tag);
			break;
		}
		default:
			vtag = ntohl(chunk->sctp_hdr->vtag);
			break;
		}
	}

	/* Make a transport for the bucket, Eliza... */
	transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
	if (!transport)
		goto nomem;

	transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;

	/* Cache a route for the transport with the chunk's destination as
	 * the source address.
	 */
	sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
			     sctp_sk(net->sctp.ctl_sock));

	packet = &transport->packet;
	sctp_packet_init(packet, transport, sport, dport);
	sctp_packet_config(packet, vtag, 0);

	return packet;

nomem:
	return NULL;
}

/* Free the packet allocated earlier for responding in the OOTB condition.  */
void sctp_ootb_pkt_free(struct sctp_packet *packet)
{
	sctp_transport_free(packet->transport);
}

/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found  */
static void sctp_send_stale_cookie_err(struct net *net,
				       const struct sctp_endpoint *ep,
				       const struct sctp_association *asoc,
				       const struct sctp_chunk *chunk,
				       struct sctp_cmd_seq *commands,
				       struct sctp_chunk *err_chunk)
{
	struct sctp_packet *packet;

	if (err_chunk) {
		packet = sctp_ootb_pkt_new(net, asoc, chunk);
		if (packet) {
			struct sctp_signed_cookie *cookie;

			/* Override the OOTB vtag from the cookie. */
			cookie = chunk->subh.cookie_hdr;
			packet->vtag = cookie->c.peer_vtag;

			/* Set the skb to the belonging sock for accounting. */
			err_chunk->skb->sk = ep->base.sk;
			sctp_packet_append_chunk(packet, err_chunk);
			sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
					SCTP_PACKET(packet));
			SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
		} else
			sctp_chunk_free (err_chunk);
	}
}


/* Process a data chunk */
static int sctp_eat_data(const struct sctp_association *asoc,
			 struct sctp_chunk *chunk,
			 struct sctp_cmd_seq *commands)
{
	struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
	struct sock *sk = asoc->base.sk;
	struct net *net = sock_net(sk);
	struct sctp_datahdr *data_hdr;
	struct sctp_chunk *err;
	enum sctp_verb deliver;
	size_t datalen;
	__u32 tsn;
	int tmp;

	data_hdr = (struct sctp_datahdr *)chunk->skb->data;
	chunk->subh.data_hdr = data_hdr;
	skb_pull(chunk->skb, sctp_datahdr_len(&asoc->stream));

	tsn = ntohl(data_hdr->tsn);
	pr_debug("%s: TSN 0x%x\n", __func__, tsn);

	/* ASSERT:  Now skb->data is really the user data.  */

	/* Process ECN based congestion.
	 *
	 * Since the chunk structure is reused for all chunks within
	 * a packet, we use ecn_ce_done to track if we've already
	 * done CE processing for this packet.
	 *
	 * We need to do ECN processing even if we plan to discard the
	 * chunk later.
	 */

	if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) {
		struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af;
		chunk->ecn_ce_done = 1;

		if (af->is_ce(sctp_gso_headskb(chunk->skb))) {
			/* Do real work as side effect. */
			sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
					SCTP_U32(tsn));
		}
	}

	tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
	if (tmp < 0) {
		/* The TSN is too high--silently discard the chunk and
		 * count on it getting retransmitted later.
		 */
		if (chunk->asoc)
			chunk->asoc->stats.outofseqtsns++;
		return SCTP_IERROR_HIGH_TSN;
	} else if (tmp > 0) {
		/* This is a duplicate.  Record it.  */
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
		return SCTP_IERROR_DUP_TSN;
	}

	/* This is a new TSN.  */

	/* Discard if there is no room in the receive window.
	 * Actually, allow a little bit of overflow (up to a MTU).
	 */
	datalen = ntohs(chunk->chunk_hdr->length);
	datalen -= sctp_datachk_len(&asoc->stream);

	deliver = SCTP_CMD_CHUNK_ULP;

	/* Think about partial delivery. */
	if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {

		/* Even if we don't accept this chunk there is
		 * memory pressure.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
	}

	/* Spill over rwnd a little bit.  Note: While allowed, this spill over
	 * seems a bit troublesome in that frag_point varies based on
	 * PMTU.  In cases, such as loopback, this might be a rather
	 * large spill over.
	 */
	if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
	    (datalen > asoc->rwnd + asoc->frag_point))) {

		/* If this is the next TSN, consider reneging to make
		 * room.   Note: Playing nice with a confused sender.  A
		 * malicious sender can still eat up all our buffer
		 * space and in the future we may want to detect and
		 * do more drastic reneging.
		 */
		if (sctp_tsnmap_has_gap(map) &&
		    (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
			pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
			deliver = SCTP_CMD_RENEGE;
		} else {
			pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
				 __func__, tsn, datalen, asoc->rwnd);

			return SCTP_IERROR_IGNORE_TSN;
		}
	}

	/*
	 * Also try to renege to limit our memory usage in the event that
	 * we are under memory pressure
	 * If we can't renege, don't worry about it, the sk_rmem_schedule
	 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
	 * memory usage too much
	 */
	if (sk_under_memory_pressure(sk)) {
		if (sctp_tsnmap_has_gap(map) &&
		    (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
			pr_debug("%s: under pressure, reneging for tsn:%u\n",
				 __func__, tsn);
			deliver = SCTP_CMD_RENEGE;
		} else {
			sk_mem_reclaim(sk);
		}
	}

	/*
	 * Section 3.3.10.9 No User Data (9)
	 *
	 * Cause of error
	 * ---------------
	 * No User Data:  This error cause is returned to the originator of a
	 * DATA chunk if a received DATA chunk has no user data.
	 */
	if (unlikely(0 == datalen)) {
		err = sctp_make_abort_no_data(asoc, chunk, tsn);
		if (err) {
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(err));
		}
		/* We are going to ABORT, so we might as well stop
		 * processing the rest of the chunks in the packet.
		 */
		sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
				SCTP_ERROR(ECONNABORTED));
		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
				SCTP_PERR(SCTP_ERROR_NO_DATA));
		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
		return SCTP_IERROR_NO_DATA;
	}

	chunk->data_accepted = 1;

	/* Note: Some chunks may get overcounted (if we drop) or overcounted
	 * if we renege and the chunk arrives again.
	 */
	if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
		SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
		if (chunk->asoc)
			chunk->asoc->stats.iuodchunks++;
	} else {
		SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
		if (chunk->asoc)
			chunk->asoc->stats.iodchunks++;
	}

	/* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
	 *
	 * If an endpoint receive a DATA chunk with an invalid stream
	 * identifier, it shall acknowledge the reception of the DATA chunk
	 * following the normal procedure, immediately send an ERROR chunk
	 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
	 * and discard the DATA chunk.
	 */
	if (ntohs(data_hdr->stream) >= asoc->stream.incnt) {
		/* Mark tsn as received even though we drop it */
		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));

		err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
					 &data_hdr->stream,
					 sizeof(data_hdr->stream),
					 sizeof(u16));
		if (err)
			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
					SCTP_CHUNK(err));
		return SCTP_IERROR_BAD_STREAM;
	}

	/* Check to see if the SSN is possible for this TSN.
	 * The biggest gap we can record is 4K wide.  Since SSNs wrap
	 * at an unsigned short, there is no way that an SSN can
	 * wrap and for a valid TSN.  We can simply check if the current
	 * SSN is smaller then the next expected one.  If it is, it wrapped
	 * and is invalid.
	 */
	if (!asoc->stream.si->validate_data(chunk))
		return SCTP_IERROR_PROTO_VIOLATION;

	/* Send the data up to the user.  Note:  Schedule  the
	 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
	 * chunk needs the updated rwnd.
	 */
	sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));

	return SCTP_IERROR_NO_ERROR;
}