summaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/sfc/tc_conntrack.c
blob: 8e06bfbcbea17cc5c3984d37a41725e61c895433 (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
// SPDX-License-Identifier: GPL-2.0-only
/****************************************************************************
 * Driver for Solarflare network controllers and boards
 * Copyright 2023, Advanced Micro Devices, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */

#include "tc_conntrack.h"
#include "tc.h"
#include "mae.h"

static int efx_tc_flow_block(enum tc_setup_type type, void *type_data,
			     void *cb_priv);

static const struct rhashtable_params efx_tc_ct_zone_ht_params = {
	.key_len	= offsetof(struct efx_tc_ct_zone, linkage),
	.key_offset	= 0,
	.head_offset	= offsetof(struct efx_tc_ct_zone, linkage),
};

static const struct rhashtable_params efx_tc_ct_ht_params = {
	.key_len	= offsetof(struct efx_tc_ct_entry, linkage),
	.key_offset	= 0,
	.head_offset	= offsetof(struct efx_tc_ct_entry, linkage),
};

static void efx_tc_ct_zone_free(void *ptr, void *arg)
{
	struct efx_tc_ct_zone *zone = ptr;
	struct efx_nic *efx = zone->efx;

	netif_err(efx, drv, efx->net_dev,
		  "tc ct_zone %u still present at teardown, removing\n",
		  zone->zone);

	nf_flow_table_offload_del_cb(zone->nf_ft, efx_tc_flow_block, zone);
	kfree(zone);
}

static void efx_tc_ct_free(void *ptr, void *arg)
{
	struct efx_tc_ct_entry *conn = ptr;
	struct efx_nic *efx = arg;

	netif_err(efx, drv, efx->net_dev,
		  "tc ct_entry %lx still present at teardown\n",
		  conn->cookie);

	/* We can release the counter, but we can't remove the CT itself
	 * from hardware because the table meta is already gone.
	 */
	efx_tc_flower_release_counter(efx, conn->cnt);
	kfree(conn);
}

int efx_tc_init_conntrack(struct efx_nic *efx)
{
	int rc;

	rc = rhashtable_init(&efx->tc->ct_zone_ht, &efx_tc_ct_zone_ht_params);
	if (rc < 0)
		goto fail_ct_zone_ht;
	rc = rhashtable_init(&efx->tc->ct_ht, &efx_tc_ct_ht_params);
	if (rc < 0)
		goto fail_ct_ht;
	return 0;
fail_ct_ht:
	rhashtable_destroy(&efx->tc->ct_zone_ht);
fail_ct_zone_ht:
	return rc;
}

/* Only call this in init failure teardown.
 * Normal exit should fini instead as there may be entries in the table.
 */
void efx_tc_destroy_conntrack(struct efx_nic *efx)
{
	rhashtable_destroy(&efx->tc->ct_ht);
	rhashtable_destroy(&efx->tc->ct_zone_ht);
}

void efx_tc_fini_conntrack(struct efx_nic *efx)
{
	rhashtable_free_and_destroy(&efx->tc->ct_zone_ht, efx_tc_ct_zone_free, NULL);
	rhashtable_free_and_destroy(&efx->tc->ct_ht, efx_tc_ct_free, efx);
}

#define EFX_NF_TCP_FLAG(flg)	cpu_to_be16(be32_to_cpu(TCP_FLAG_##flg) >> 16)

static int efx_tc_ct_parse_match(struct efx_nic *efx, struct flow_rule *fr,
				 struct efx_tc_ct_entry *conn)
{
	struct flow_dissector *dissector = fr->match.dissector;
	unsigned char ipv = 0;
	bool tcp = false;

	if (flow_rule_match_key(fr, FLOW_DISSECTOR_KEY_CONTROL)) {
		struct flow_match_control fm;

		flow_rule_match_control(fr, &fm);
		if (IS_ALL_ONES(fm.mask->addr_type))
			switch (fm.key->addr_type) {
			case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
				ipv = 4;
				break;
			case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
				ipv = 6;
				break;
			default:
				break;
			}
	}

	if (!ipv) {
		netif_dbg(efx, drv, efx->net_dev,
			  "Conntrack missing ipv specification\n");
		return -EOPNOTSUPP;
	}

	if (dissector->used_keys &
	    ~(BIT_ULL(FLOW_DISSECTOR_KEY_CONTROL) |
	      BIT_ULL(FLOW_DISSECTOR_KEY_BASIC) |
	      BIT_ULL(FLOW_DISSECTOR_KEY_IPV4_ADDRS) |
	      BIT_ULL(FLOW_DISSECTOR_KEY_IPV6_ADDRS) |
	      BIT_ULL(FLOW_DISSECTOR_KEY_PORTS) |
	      BIT_ULL(FLOW_DISSECTOR_KEY_TCP) |
	      BIT_ULL(FLOW_DISSECTOR_KEY_META))) {
		netif_dbg(efx, drv, efx->net_dev,
			  "Unsupported conntrack keys %#llx\n",
			  dissector->used_keys);
		return -EOPNOTSUPP;
	}

	if (flow_rule_match_key(fr, FLOW_DISSECTOR_KEY_BASIC)) {
		struct flow_match_basic fm;

		flow_rule_match_basic(fr, &fm);
		if (!IS_ALL_ONES(fm.mask->n_proto)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack eth_proto is not exact-match; mask %04x\n",
				   ntohs(fm.mask->n_proto));
			return -EOPNOTSUPP;
		}
		conn->eth_proto = fm.key->n_proto;
		if (conn->eth_proto != (ipv == 4 ? htons(ETH_P_IP)
						 : htons(ETH_P_IPV6))) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack eth_proto is not IPv%u, is %04x\n",
				   ipv, ntohs(conn->eth_proto));
			return -EOPNOTSUPP;
		}
		if (!IS_ALL_ONES(fm.mask->ip_proto)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ip_proto is not exact-match; mask %02x\n",
				   fm.mask->ip_proto);
			return -EOPNOTSUPP;
		}
		conn->ip_proto = fm.key->ip_proto;
		switch (conn->ip_proto) {
		case IPPROTO_TCP:
			tcp = true;
			break;
		case IPPROTO_UDP:
			break;
		default:
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ip_proto not TCP or UDP, is %02x\n",
				   conn->ip_proto);
			return -EOPNOTSUPP;
		}
	} else {
		netif_dbg(efx, drv, efx->net_dev,
			  "Conntrack missing eth_proto, ip_proto\n");
		return -EOPNOTSUPP;
	}

	if (ipv == 4 && flow_rule_match_key(fr, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
		struct flow_match_ipv4_addrs fm;

		flow_rule_match_ipv4_addrs(fr, &fm);
		if (!IS_ALL_ONES(fm.mask->src)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ipv4.src is not exact-match; mask %08x\n",
				   ntohl(fm.mask->src));
			return -EOPNOTSUPP;
		}
		conn->src_ip = fm.key->src;
		if (!IS_ALL_ONES(fm.mask->dst)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ipv4.dst is not exact-match; mask %08x\n",
				   ntohl(fm.mask->dst));
			return -EOPNOTSUPP;
		}
		conn->dst_ip = fm.key->dst;
	} else if (ipv == 6 && flow_rule_match_key(fr, FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
		struct flow_match_ipv6_addrs fm;

		flow_rule_match_ipv6_addrs(fr, &fm);
		if (!efx_ipv6_addr_all_ones(&fm.mask->src)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ipv6.src is not exact-match; mask %pI6\n",
				   &fm.mask->src);
			return -EOPNOTSUPP;
		}
		conn->src_ip6 = fm.key->src;
		if (!efx_ipv6_addr_all_ones(&fm.mask->dst)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ipv6.dst is not exact-match; mask %pI6\n",
				   &fm.mask->dst);
			return -EOPNOTSUPP;
		}
		conn->dst_ip6 = fm.key->dst;
	} else {
		netif_dbg(efx, drv, efx->net_dev,
			  "Conntrack missing IPv%u addrs\n", ipv);
		return -EOPNOTSUPP;
	}

	if (flow_rule_match_key(fr, FLOW_DISSECTOR_KEY_PORTS)) {
		struct flow_match_ports fm;

		flow_rule_match_ports(fr, &fm);
		if (!IS_ALL_ONES(fm.mask->src)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ports.src is not exact-match; mask %04x\n",
				   ntohs(fm.mask->src));
			return -EOPNOTSUPP;
		}
		conn->l4_sport = fm.key->src;
		if (!IS_ALL_ONES(fm.mask->dst)) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack ports.dst is not exact-match; mask %04x\n",
				   ntohs(fm.mask->dst));
			return -EOPNOTSUPP;
		}
		conn->l4_dport = fm.key->dst;
	} else {
		netif_dbg(efx, drv, efx->net_dev, "Conntrack missing L4 ports\n");
		return -EOPNOTSUPP;
	}

	if (flow_rule_match_key(fr, FLOW_DISSECTOR_KEY_TCP)) {
		__be16 tcp_interesting_flags;
		struct flow_match_tcp fm;

		if (!tcp) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Conntrack matching on TCP keys but ipproto is not tcp\n");
			return -EOPNOTSUPP;
		}
		flow_rule_match_tcp(fr, &fm);
		tcp_interesting_flags = EFX_NF_TCP_FLAG(SYN) |
					EFX_NF_TCP_FLAG(RST) |
					EFX_NF_TCP_FLAG(FIN);
		/* If any of the tcp_interesting_flags is set, we always
		 * inhibit CT lookup in LHS (so SW can update CT table).
		 */
		if (fm.key->flags & tcp_interesting_flags) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Unsupported conntrack tcp.flags %04x/%04x\n",
				   ntohs(fm.key->flags), ntohs(fm.mask->flags));
			return -EOPNOTSUPP;
		}
		/* Other TCP flags cannot be filtered at CT */
		if (fm.mask->flags & ~tcp_interesting_flags) {
			netif_dbg(efx, drv, efx->net_dev,
				  "Unsupported conntrack tcp.flags %04x/%04x\n",
				   ntohs(fm.key->flags), ntohs(fm.mask->flags));
			return -EOPNOTSUPP;
		}
	}

	return 0;
}

static int efx_tc_ct_replace(struct efx_tc_ct_zone *ct_zone,
			     struct flow_cls_offload *tc)
{
	struct flow_rule *fr = flow_cls_offload_flow_rule(tc);
	struct efx_tc_ct_entry *conn, *old;
	struct efx_nic *efx = ct_zone->efx;
	const struct flow_action_entry *fa;
	struct efx_tc_counter *cnt;
	int rc, i;

	if (WARN_ON(!efx->tc))
		return -ENETDOWN;
	if (WARN_ON(!efx->tc->up))
		return -ENETDOWN;

	conn = kzalloc(sizeof(*conn), GFP_USER);
	if (!conn)
		return -ENOMEM;
	conn->cookie = tc->cookie;
	old = rhashtable_lookup_get_insert_fast(&efx->tc->ct_ht,
						&conn->linkage,
						efx_tc_ct_ht_params);
	if (old) {
		netif_dbg(efx, drv, efx->net_dev,
			  "Already offloaded conntrack (cookie %lx)\n", tc->cookie);
		rc = -EEXIST;
		goto release;
	}

	/* Parse match */
	conn->zone = ct_zone;
	rc = efx_tc_ct_parse_match(efx, fr, conn);
	if (rc)
		goto release;

	/* Parse actions */
	flow_action_for_each(i, fa, &fr->action) {
		switch (fa->id) {
		case FLOW_ACTION_CT_METADATA:
			conn->mark = fa->ct_metadata.mark;
			if (memchr_inv(fa->ct_metadata.labels, 0, sizeof(fa->ct_metadata.labels))) {
				netif_dbg(efx, drv, efx->net_dev,
					  "Setting CT label not supported\n");
				rc = -EOPNOTSUPP;
				goto release;
			}
			break;
		default:
			netif_dbg(efx, drv, efx->net_dev,
				  "Unhandled action %u for conntrack\n", fa->id);
			rc = -EOPNOTSUPP;
			goto release;
		}
	}

	/* fill in defaults for unmangled values */
	conn->nat_ip = conn->dnat ? conn->dst_ip : conn->src_ip;
	conn->l4_natport = conn->dnat ? conn->l4_dport : conn->l4_sport;

	cnt = efx_tc_flower_allocate_counter(efx, EFX_TC_COUNTER_TYPE_CT);
	if (IS_ERR(cnt)) {
		rc = PTR_ERR(cnt);
		goto release;
	}
	conn->cnt = cnt;

	rc = efx_mae_insert_ct(efx, conn);
	if (rc) {
		netif_dbg(efx, drv, efx->net_dev,
			  "Failed to insert conntrack, %d\n", rc);
		goto release;
	}
	mutex_lock(&ct_zone->mutex);
	list_add_tail(&conn->list, &ct_zone->cts);
	mutex_unlock(&ct_zone->mutex);
	return 0;
release:
	if (conn->cnt)
		efx_tc_flower_release_counter(efx, conn->cnt);
	if (!old)
		rhashtable_remove_fast(&efx->tc->ct_ht, &conn->linkage,
				       efx_tc_ct_ht_params);
	kfree(conn);
	return rc;
}

/* Caller must follow with efx_tc_ct_remove_finish() after RCU grace period! */
static void efx_tc_ct_remove(struct efx_nic *efx, struct efx_tc_ct_entry *conn)
{
	int rc;

	/* Remove it from HW */
	rc = efx_mae_remove_ct(efx, conn);
	/* Delete it from SW */
	rhashtable_remove_fast(&efx->tc->ct_ht, &conn->linkage,
			       efx_tc_ct_ht_params);
	if (rc) {
		netif_err(efx, drv, efx->net_dev,
			  "Failed to remove conntrack %lx from hw, rc %d\n",
			  conn->cookie, rc);
	} else {
		netif_dbg(efx, drv, efx->net_dev, "Removed conntrack %lx\n",
			  conn->cookie);
	}
}

static void efx_tc_ct_remove_finish(struct efx_nic *efx, struct efx_tc_ct_entry *conn)
{
	/* Remove related CT counter.  This is delayed after the conn object we
	 * are working with has been successfully removed.  This protects the
	 * counter from being used-after-free inside efx_tc_ct_stats.
	 */
	efx_tc_flower_release_counter(efx, conn->cnt);
	kfree(conn);
}

static int efx_tc_ct_destroy(struct efx_tc_ct_zone *ct_zone,
			     struct flow_cls_offload *tc)
{
	struct efx_nic *efx = ct_zone->efx;
	struct efx_tc_ct_entry *conn;

	conn = rhashtable_lookup_fast(&efx->tc->ct_ht, &tc->cookie,
				      efx_tc_ct_ht_params);
	if (!conn) {
		netif_warn(efx, drv, efx->net_dev,
			   "Conntrack %lx not found to remove\n", tc->cookie);
		return -ENOENT;
	}

	mutex_lock(&ct_zone->mutex);
	list_del(&conn->list);
	efx_tc_ct_remove(efx, conn);
	mutex_unlock(&ct_zone->mutex);
	synchronize_rcu();
	efx_tc_ct_remove_finish(efx, conn);
	return 0;
}

static int efx_tc_ct_stats(struct efx_tc_ct_zone *ct_zone,
			   struct flow_cls_offload *tc)
{
	struct efx_nic *efx = ct_zone->efx;
	struct efx_tc_ct_entry *conn;
	struct efx_tc_counter *cnt;

	rcu_read_lock();
	conn = rhashtable_lookup_fast(&efx->tc->ct_ht, &tc->cookie,
				      efx_tc_ct_ht_params);
	if (!conn) {
		netif_warn(efx, drv, efx->net_dev,
			   "Conntrack %lx not found for stats\n", tc->cookie);
		rcu_read_unlock();
		return -ENOENT;
	}

	cnt = conn->cnt;
	spin_lock_bh(&cnt->lock);
	/* Report only last use */
	flow_stats_update(&tc->stats, 0, 0, 0, cnt->touched,
			  FLOW_ACTION_HW_STATS_DELAYED);
	spin_unlock_bh(&cnt->lock);
	rcu_read_unlock();

	return 0;
}

static int efx_tc_flow_block(enum tc_setup_type type, void *type_data,
			     void *cb_priv)
{
	struct flow_cls_offload *tcb = type_data;
	struct efx_tc_ct_zone *ct_zone = cb_priv;

	if (type != TC_SETUP_CLSFLOWER)
		return -EOPNOTSUPP;

	switch (tcb->command) {
	case FLOW_CLS_REPLACE:
		return efx_tc_ct_replace(ct_zone, tcb);
	case FLOW_CLS_DESTROY:
		return efx_tc_ct_destroy(ct_zone, tcb);
	case FLOW_CLS_STATS:
		return efx_tc_ct_stats(ct_zone, tcb);
	default:
		break;
	}

	return -EOPNOTSUPP;
}

struct efx_tc_ct_zone *efx_tc_ct_register_zone(struct efx_nic *efx, u16 zone,
					       struct nf_flowtable *ct_ft)
{
	struct efx_tc_ct_zone *ct_zone, *old;
	int rc;

	ct_zone = kzalloc(sizeof(*ct_zone), GFP_USER);
	if (!ct_zone)
		return ERR_PTR(-ENOMEM);
	ct_zone->zone = zone;
	old = rhashtable_lookup_get_insert_fast(&efx->tc->ct_zone_ht,
						&ct_zone->linkage,
						efx_tc_ct_zone_ht_params);
	if (old) {
		/* don't need our new entry */
		kfree(ct_zone);
		if (!refcount_inc_not_zero(&old->ref))
			return ERR_PTR(-EAGAIN);
		/* existing entry found */
		WARN_ON_ONCE(old->nf_ft != ct_ft);
		netif_dbg(efx, drv, efx->net_dev,
			  "Found existing ct_zone for %u\n", zone);
		return old;
	}
	ct_zone->nf_ft = ct_ft;
	ct_zone->efx = efx;
	INIT_LIST_HEAD(&ct_zone->cts);
	mutex_init(&ct_zone->mutex);
	rc = nf_flow_table_offload_add_cb(ct_ft, efx_tc_flow_block, ct_zone);
	netif_dbg(efx, drv, efx->net_dev, "Adding new ct_zone for %u, rc %d\n",
		  zone, rc);
	if (rc < 0)
		goto fail;
	refcount_set(&ct_zone->ref, 1);
	return ct_zone;
fail:
	rhashtable_remove_fast(&efx->tc->ct_zone_ht, &ct_zone->linkage,
			       efx_tc_ct_zone_ht_params);
	kfree(ct_zone);
	return ERR_PTR(rc);
}

void efx_tc_ct_unregister_zone(struct efx_nic *efx,
			       struct efx_tc_ct_zone *ct_zone)
{
	struct efx_tc_ct_entry *conn, *next;

	if (!refcount_dec_and_test(&ct_zone->ref))
		return; /* still in use */
	nf_flow_table_offload_del_cb(ct_zone->nf_ft, efx_tc_flow_block, ct_zone);
	rhashtable_remove_fast(&efx->tc->ct_zone_ht, &ct_zone->linkage,
			       efx_tc_ct_zone_ht_params);
	mutex_lock(&ct_zone->mutex);
	list_for_each_entry(conn, &ct_zone->cts, list)
		efx_tc_ct_remove(efx, conn);
	synchronize_rcu();
	/* need to use _safe because efx_tc_ct_remove_finish() frees conn */
	list_for_each_entry_safe(conn, next, &ct_zone->cts, list)
		efx_tc_ct_remove_finish(efx, conn);
	mutex_unlock(&ct_zone->mutex);
	mutex_destroy(&ct_zone->mutex);
	netif_dbg(efx, drv, efx->net_dev, "Removed ct_zone for %u\n",
		  ct_zone->zone);
	kfree(ct_zone);
}