netfilter: ipset: Fix cidr handling for hash:*net* types

Commit "Simplify cidr handling for hash:*net* types" broke the cidr
handling for the hash:*net* types when the sets were used by the SET
target: entries with invalid cidr values were added to the sets.
Reported by Jonathan Johnson.

Testsuite entry is added to verify the fix.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

1 files changed, 26 insertions, 18 deletions

diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index 8dd82db05ed0..2f1985e71f6c 100644
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -149,17 +149,21 @@ hbucket_elem_add(struct hbucket *n, u8 ahash_max, size_t dsize)
 #endif
 
 /* cidr + 1 is stored in net_prefixes to support /0 */
-#define SCIDR(cidr, i)		(__CIDR(cidr, i) + 1)
+#define NCIDR_PUT(cidr)		((cidr) + 1)
+#define NCIDR_GET(cidr)		((cidr) - 1)
 
 #ifdef IP_SET_HASH_WITH_NETS_PACKED
 /* When cidr is packed with nomatch, cidr - 1 is stored in the data entry */
-#define GCIDR(cidr, i)		(__CIDR(cidr, i) + 1)
-#define NCIDR(cidr)		(cidr)
+#define DCIDR_PUT(cidr)		((cidr) - 1)
+#define DCIDR_GET(cidr, i)	(__CIDR(cidr, i) + 1)
 #else
-#define GCIDR(cidr, i)		(__CIDR(cidr, i))
-#define NCIDR(cidr)		(cidr - 1)
+#define DCIDR_PUT(cidr)		(cidr)
+#define DCIDR_GET(cidr, i)	__CIDR(cidr, i)
 #endif
 
+#define INIT_CIDR(cidr, host_mask)	\
+	DCIDR_PUT(((cidr) ? NCIDR_GET(cidr) : host_mask))
+
 #define SET_HOST_MASK(family)	(family == AF_INET ? 32 : 128)
 
 #ifdef IP_SET_HASH_WITH_NET0
@@ -303,7 +307,8 @@ struct htype {
 
 #ifdef IP_SET_HASH_WITH_NETS
 /* Network cidr size book keeping when the hash stores different
- * sized networks */
+ * sized networks. cidr == real cidr + 1 to support /0.
+ */
 static void
 mtype_add_cidr(struct htype *h, u8 cidr, u8 nets_length, u8 n)
 {
@@ -498,8 +503,10 @@ mtype_expire(struct ip_set *set, struct htype *h, u8 nets_length, size_t dsize)
 				pr_debug("expired %u/%u\n", i, j);
 #ifdef IP_SET_HASH_WITH_NETS
 				for (k = 0; k < IPSET_NET_COUNT; k++)
-					mtype_del_cidr(h, SCIDR(data->cidr, k),
-						       nets_length, k);
+					mtype_del_cidr(h,
+						NCIDR_PUT(DCIDR_GET(data->cidr,
+								    k)),
+						nets_length, k);
 #endif
 				ip_set_ext_destroy(set, data);
 				if (j != n->pos - 1)
@@ -692,9 +699,9 @@ reuse_slot:
 		data = ahash_data(n, j, set->dsize);
 #ifdef IP_SET_HASH_WITH_NETS
 		for (i = 0; i < IPSET_NET_COUNT; i++) {
-			mtype_del_cidr(h, SCIDR(data->cidr, i),
+			mtype_del_cidr(h, NCIDR_PUT(DCIDR_GET(data->cidr, i)),
 				       NLEN(set->family), i);
-			mtype_add_cidr(h, SCIDR(d->cidr, i),
+			mtype_add_cidr(h, NCIDR_PUT(DCIDR_GET(d->cidr, i)),
 				       NLEN(set->family), i);
 		}
 #endif
@@ -711,8 +718,8 @@ reuse_slot:
 		data = ahash_data(n, n->pos++, set->dsize);
 #ifdef IP_SET_HASH_WITH_NETS
 		for (i = 0; i < IPSET_NET_COUNT; i++)
-			mtype_add_cidr(h, SCIDR(d->cidr, i), NLEN(set->family),
-				       i);
+			mtype_add_cidr(h, NCIDR_PUT(DCIDR_GET(d->cidr, i)),
+				       NLEN(set->family), i);
 #endif
 		h->elements++;
 	}
@@ -772,8 +779,8 @@ mtype_del(struct ip_set *set, void *value, const struct ip_set_ext *ext,
 		h->elements--;
 #ifdef IP_SET_HASH_WITH_NETS
 		for (j = 0; j < IPSET_NET_COUNT; j++)
-			mtype_del_cidr(h, SCIDR(d->cidr, j), NLEN(set->family),
-				       j);
+			mtype_del_cidr(h, NCIDR_PUT(DCIDR_GET(d->cidr, j)),
+				       NLEN(set->family), j);
 #endif
 		ip_set_ext_destroy(set, data);
 		if (n->pos + AHASH_INIT_SIZE < n->size) {
@@ -836,12 +843,13 @@ mtype_test_cidrs(struct ip_set *set, struct mtype_elem *d,
 	for (; j < nets_length && h->nets[j].cidr[0] && !multi; j++) {
 #if IPSET_NET_COUNT == 2
 		mtype_data_reset_elem(d, &orig);
-		mtype_data_netmask(d, NCIDR(h->nets[j].cidr[0]), false);
+		mtype_data_netmask(d, NCIDR_GET(h->nets[j].cidr[0]), false);
 		for (k = 0; k < nets_length && h->nets[k].cidr[1] && !multi;
 		     k++) {
-			mtype_data_netmask(d, NCIDR(h->nets[k].cidr[1]), true);
+			mtype_data_netmask(d, NCIDR_GET(h->nets[k].cidr[1]),
+					   true);
 #else
-		mtype_data_netmask(d, NCIDR(h->nets[j].cidr[0]));
+		mtype_data_netmask(d, NCIDR_GET(h->nets[j].cidr[0]));
 #endif
 		key = HKEY(d, h->initval, t->htable_bits);
 		n = hbucket(t, key);
@@ -889,7 +897,7 @@ mtype_test(struct ip_set *set, void *value, const struct ip_set_ext *ext,
 	/* If we test an IP address and not a network address,
 	 * try all possible network sizes */
 	for (i = 0; i < IPSET_NET_COUNT; i++)
-		if (GCIDR(d->cidr, i) != SET_HOST_MASK(set->family))
+		if (DCIDR_GET(d->cidr, i) != SET_HOST_MASK(set->family))
 			break;
 	if (i == IPSET_NET_COUNT) {
 		ret = mtype_test_cidrs(set, d, ext, mext, flags);