Support to match elements marked with "nomatch" in hash:*net* sets

Exceptions can now be matched and we can branch according to the
possible cases:

a. match in the set if the element is not flagged as "nomatch"
b. match in the set if the element is flagged with "nomatch"
c. no match

i.e.

iptables ... -m set --match-set ... -j ...
iptables ... -m set --match-set ... --nomatch-entries -j ...
...

11 files changed, 135 insertions, 21 deletions

diff --git a/include/libipset/linux_ip_set.h b/include/libipset/linux_ip_set.h
index 008da06..d3267a4 100644
--- a/include/libipset/linux_ip_set.h
+++ b/include/libipset/linux_ip_set.h
@@ -190,6 +190,7 @@ enum ip_set_dim {
 	 * If changed, new revision of iptables match/target is required.
 	 */
 	IPSET_DIM_MAX = 6,
+	IPSET_BIT_RETURN_NOMATCH = 7,
 };
 
 /* Option flags for kernel operations */
@@ -198,6 +199,7 @@ enum ip_set_kopt {
 	IPSET_DIM_ONE_SRC = (1 << IPSET_DIM_ONE),
 	IPSET_DIM_TWO_SRC = (1 << IPSET_DIM_TWO),
 	IPSET_DIM_THREE_SRC = (1 << IPSET_DIM_THREE),
+	IPSET_RETURN_NOMATCH = (1 << IPSET_BIT_RETURN_NOMATCH),
 };
 
 #endif /* __IP_SET_H */
diff --git a/kernel/include/linux/netfilter/ipset/ip_set.h b/kernel/include/linux/netfilter/ipset/ip_set.h
index e6bfe3b..81d9213 100644
--- a/kernel/include/linux/netfilter/ipset/ip_set.h
+++ b/kernel/include/linux/netfilter/ipset/ip_set.h
@@ -190,6 +190,7 @@ enum ip_set_dim {
 	 * If changed, new revision of iptables match/target is required.
 	 */
 	IPSET_DIM_MAX = 6,
+	IPSET_BIT_RETURN_NOMATCH = 7,
 };
 
 /* Option flags for kernel operations */
@@ -198,6 +199,7 @@ enum ip_set_kopt {
 	IPSET_DIM_ONE_SRC = (1 << IPSET_DIM_ONE),
 	IPSET_DIM_TWO_SRC = (1 << IPSET_DIM_TWO),
 	IPSET_DIM_THREE_SRC = (1 << IPSET_DIM_THREE),
+	IPSET_RETURN_NOMATCH = (1 << IPSET_BIT_RETURN_NOMATCH),
 };
 
 #ifdef __KERNEL__
@@ -229,6 +231,8 @@ enum ip_set_feature {
 	IPSET_TYPE_NAME = (1 << IPSET_TYPE_NAME_FLAG),
 	IPSET_TYPE_IFACE_FLAG = 5,
 	IPSET_TYPE_IFACE = (1 << IPSET_TYPE_IFACE_FLAG),
+	IPSET_TYPE_NOMATCH_FLAG = 6,
+	IPSET_TYPE_NOMATCH = (1 << IPSET_TYPE_NOMATCH_FLAG),
 	/* Strictly speaking not a feature, but a flag for dumping:
 	 * this settype must be dumped last */
 	IPSET_DUMP_LAST_FLAG = 7,
diff --git a/kernel/net/netfilter/ipset/ip_set_core.c b/kernel/net/netfilter/ipset/ip_set_core.c
index 57dc1bd..535e635 100644
--- a/kernel/net/netfilter/ipset/ip_set_core.c
+++ b/kernel/net/netfilter/ipset/ip_set_core.c
@@ -378,6 +378,12 @@ ip_set_test(ip_set_id_t index, const struct sk_buff *skb,
 		set->variant->kadt(set, skb, par, IPSET_ADD, opt);
 		write_unlock_bh(&set->lock);
 		ret = 1;
+	} else {
+		/* --return-nomatch: invert matched element */
+		if ((opt->flags & IPSET_RETURN_NOMATCH) &&
+		    (set->type->features & IPSET_TYPE_NOMATCH) &&
+		    (ret > 0 || ret == -ENOTEMPTY))
+			ret = -ret;
 	}
 
 	/* Convert error codes to nomatch */
diff --git a/kernel/net/netfilter/ipset/ip_set_hash_ipportnet.c b/kernel/net/netfilter/ipset/ip_set_hash_ipportnet.c
index 8ee9168..cb71f9a 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_ipportnet.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_ipportnet.c
@@ -104,10 +104,10 @@ hash_ipportnet4_data_flags(struct hash_ipportnet4_elem *dst, u32 flags)
 	dst->nomatch = !!(flags & IPSET_FLAG_NOMATCH);
 }
 
-static inline bool
+static inline int
 hash_ipportnet4_data_match(const struct hash_ipportnet4_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -411,10 +411,10 @@ hash_ipportnet6_data_flags(struct hash_ipportnet6_elem *dst, u32 flags)
 	dst->nomatch = !!(flags & IPSET_FLAG_NOMATCH);
 }
 
-static inline bool
+static inline int
 hash_ipportnet6_data_match(const struct hash_ipportnet6_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -697,7 +697,8 @@ hash_ipportnet_create(struct ip_set *set, struct nlattr *tb[], u32 flags)
 static struct ip_set_type hash_ipportnet_type __read_mostly = {
 	.name		= "hash:ip,port,net",
 	.protocol	= IPSET_PROTOCOL,
-	.features	= IPSET_TYPE_IP | IPSET_TYPE_PORT | IPSET_TYPE_IP2,
+	.features	= IPSET_TYPE_IP | IPSET_TYPE_PORT | IPSET_TYPE_IP2 |
+			  IPSET_TYPE_NOMATCH,
 	.dimension	= IPSET_DIM_THREE,
 	.family		= NFPROTO_UNSPEC,
 	.revision_min	= REVISION_MIN,
diff --git a/kernel/net/netfilter/ipset/ip_set_hash_net.c b/kernel/net/netfilter/ipset/ip_set_hash_net.c
index 014ff72..29e94b9 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_net.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_net.c
@@ -90,10 +90,10 @@ hash_net4_data_flags(struct hash_net4_elem *dst, u32 flags)
 	dst->nomatch = flags & IPSET_FLAG_NOMATCH;
 }
 
-static inline bool
+static inline int
 hash_net4_data_match(const struct hash_net4_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -311,10 +311,10 @@ hash_net6_data_flags(struct hash_net6_elem *dst, u32 flags)
 	dst->nomatch = flags & IPSET_FLAG_NOMATCH;
 }
 
-static inline bool
+static inline int
 hash_net6_data_match(const struct hash_net6_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -536,7 +536,7 @@ hash_net_create(struct ip_set *set, struct nlattr *tb[], u32 flags)
 static struct ip_set_type hash_net_type __read_mostly = {
 	.name		= "hash:net",
 	.protocol	= IPSET_PROTOCOL,
-	.features	= IPSET_TYPE_IP,
+	.features	= IPSET_TYPE_IP | IPSET_TYPE_NOMATCH,
 	.dimension	= IPSET_DIM_ONE,
 	.family		= NFPROTO_UNSPEC,
 	.revision_min	= REVISION_MIN,
diff --git a/kernel/net/netfilter/ipset/ip_set_hash_netiface.c b/kernel/net/netfilter/ipset/ip_set_hash_netiface.c
index a5c8491..b9a6338 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_netiface.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_netiface.c
@@ -201,10 +201,10 @@ hash_netiface4_data_flags(struct hash_netiface4_elem *dst, u32 flags)
 	dst->nomatch = flags & IPSET_FLAG_NOMATCH;
 }
 
-static inline bool
+static inline int
 hash_netiface4_data_match(const struct hash_netiface4_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -497,10 +497,10 @@ hash_netiface6_data_flags(struct hash_netiface6_elem *dst, u32 flags)
 	dst->nomatch = flags & IPSET_FLAG_NOMATCH;
 }
 
-static inline bool
+static inline int
 hash_netiface6_data_match(const struct hash_netiface6_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -774,7 +774,8 @@ hash_netiface_create(struct ip_set *set, struct nlattr *tb[], u32 flags)
 static struct ip_set_type hash_netiface_type __read_mostly = {
 	.name		= "hash:net,iface",
 	.protocol	= IPSET_PROTOCOL,
-	.features	= IPSET_TYPE_IP | IPSET_TYPE_IFACE,
+	.features	= IPSET_TYPE_IP | IPSET_TYPE_IFACE |
+			  IPSET_TYPE_NOMATCH,
 	.dimension	= IPSET_DIM_TWO,
 	.family		= NFPROTO_UNSPEC,
 	.revision_min	= REVISION_MIN,
diff --git a/kernel/net/netfilter/ipset/ip_set_hash_netport.c b/kernel/net/netfilter/ipset/ip_set_hash_netport.c
index 7ca357a..7ef700d 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_netport.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_netport.c
@@ -104,10 +104,10 @@ hash_netport4_data_flags(struct hash_netport4_elem *dst, u32 flags)
 	dst->nomatch = !!(flags & IPSET_FLAG_NOMATCH);
 }
 
-static inline bool
+static inline int
 hash_netport4_data_match(const struct hash_netport4_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -375,10 +375,10 @@ hash_netport6_data_flags(struct hash_netport6_elem *dst, u32 flags)
 	dst->nomatch = !!(flags & IPSET_FLAG_NOMATCH);
 }
 
-static inline bool
+static inline int
 hash_netport6_data_match(const struct hash_netport6_elem *elem)
 {
-	return !elem->nomatch;
+	return elem->nomatch ? -ENOTEMPTY : 1;
 }
 
 static inline void
@@ -650,7 +650,7 @@ hash_netport_create(struct ip_set *set, struct nlattr *tb[], u32 flags)
 static struct ip_set_type hash_netport_type __read_mostly = {
 	.name		= "hash:net,port",
 	.protocol	= IPSET_PROTOCOL,
-	.features	= IPSET_TYPE_IP | IPSET_TYPE_PORT,
+	.features	= IPSET_TYPE_IP | IPSET_TYPE_PORT | IPSET_TYPE_NOMATCH,
 	.dimension	= IPSET_DIM_TWO,
 	.family		= NFPROTO_UNSPEC,
 	.revision_min	= REVISION_MIN,
diff --git a/kernel/net/netfilter/xt_set.c b/kernel/net/netfilter/xt_set.c
index c6f7db7..865a9e5 100644
--- a/kernel/net/netfilter/xt_set.c
+++ b/kernel/net/netfilter/xt_set.c
@@ -356,6 +356,27 @@ static struct xt_match set_matches[] __read_mostly = {
 		.destroy	= set_match_v1_destroy,
 		.me		= THIS_MODULE
 	},
+	/* --return-nomatch flag support */
+	{
+		.name		= "set",
+		.family		= NFPROTO_IPV4,
+		.revision	= 2,
+		.match		= set_match_v1,
+		.matchsize	= sizeof(struct xt_set_info_match_v1),
+		.checkentry	= set_match_v1_checkentry,
+		.destroy	= set_match_v1_destroy,
+		.me		= THIS_MODULE
+	},
+	{
+		.name		= "set",
+		.family		= NFPROTO_IPV6,
+		.revision	= 2,
+		.match		= set_match_v1,
+		.matchsize	= sizeof(struct xt_set_info_match_v1),
+		.checkentry	= set_match_v1_checkentry,
+		.destroy	= set_match_v1_destroy,
+		.me		= THIS_MODULE
+	},
 };
 
 static struct xt_target set_targets[] __read_mostly = {
@@ -389,6 +410,7 @@ static struct xt_target set_targets[] __read_mostly = {
 		.destroy	= set_target_v1_destroy,
 		.me		= THIS_MODULE
 	},
+	/* --timeout and --exist flags support */
 	{
 		.name		= "SET",
 		.revision	= 2,
diff --git a/tests/iptables.sh b/tests/iptables.sh
index 9b1c90c..63b0b92 100755
--- a/tests/iptables.sh
+++ b/tests/iptables.sh
@@ -59,6 +59,35 @@ start)
 		      -j LOG --log-prefix "in set list: "
 	$cmd -A OUTPUT -d $NET -j DROP
 	cat /dev/null > .foo.err
+	cat /dev/null > /var/log/kern.log
+	;;
+start_flags)
+	../src/ipset n test hash:net $family 2>/dev/null
+	../src/ipset a test 10.0.0.0/16 2>/dev/null
+	../src/ipset a test 10.0.0.0/24 nomatch 2>/dev/null
+	../src/ipset a test 10.0.0.1 2>/dev/null
+	$cmd -A INPUT ! -s 10.0.0.0/16 -j ACCEPT
+	$cmd -A INPUT -m set --match-set test src \
+		      -j LOG --log-prefix "in set test: "
+	$cmd -A INPUT -m set --match-set test src --return-nomatch \
+		      -j LOG --log-prefix "in set test-nomatch: "
+	$cmd -A INPUT -s 10.0.0.0/16 -j DROP
+	cat /dev/null > .foo.err
+	cat /dev/null > /var/log/kern.log
+	;;
+start_flags_reversed)
+	../src/ipset n test hash:net $family 2>/dev/null
+	../src/ipset a test 10.0.0.0/16 2>/dev/null
+	../src/ipset a test 10.0.0.0/24 nomatch 2>/dev/null
+	../src/ipset a test 10.0.0.1 2>/dev/null
+	$cmd -A INPUT ! -s 10.0.0.0/16 -j ACCEPT
+	$cmd -A INPUT -m set --match-set test src --return-nomatch \
+		      -j LOG --log-prefix "in set test-nomatch: "
+	$cmd -A INPUT -m set --match-set test src \
+		      -j LOG --log-prefix "in set test: "
+	$cmd -A INPUT -s 10.0.0.0/16 -j DROP
+	cat /dev/null > .foo.err
+	cat /dev/null > /var/log/kern.log
 	;;
 del)
 	$cmd -F INPUT
diff --git a/tests/match_flags.t b/tests/match_flags.t
new file mode 100644
index 0000000..8cede10
--- /dev/null
+++ b/tests/match_flags.t
@@ -0,0 +1,49 @@
+# Create sets and inet rules which call set match
+0 ./iptables.sh inet start_flags
+# Send probe packet from 10.0.0.0,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.0.0 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched with --return-nomatch
+0 ./check_klog.sh 10.0.0.0 tcp 1025 test-nomatch
+# Send probe packet from 10.0.0.1,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.0.1 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched
+0 ./check_klog.sh 10.0.0.1 tcp 1025 test
+# Send probe packet from 10.0.0.2,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.2 -is 10.0.0.2 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched with --return-nomatch
+0 ./check_klog.sh 10.0.0.2 tcp 1025 test-nomatch
+# Send probe packet from 10.0.0.255,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.0.255 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched with --return-nomatch
+0 ./check_klog.sh 10.0.0.255 tcp 1025 test-nomatch
+# Send probe packet from 10.0.1.0,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.1.0 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched
+0 ./check_klog.sh 10.0.1.0 tcp 1025 test
+# Destroy sets and rules
+0 ./iptables.sh inet stop
+# Create sets and inet rules which call set match, reversed rule order
+0 ./iptables.sh inet start_flags_reversed
+# Send probe packet from 10.0.0.0,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.0.0 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched with --return-nomatch
+0 ./check_klog.sh 10.0.0.0 tcp 1025 test-nomatch
+# Send probe packet from 10.0.0.1,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.0.1 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched
+0 ./check_klog.sh 10.0.0.1 tcp 1025 test
+# Send probe packet from 10.0.0.2,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.2 -is 10.0.0.2 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched with --return-nomatch
+0 ./check_klog.sh 10.0.0.2 tcp 1025 test-nomatch
+# Send probe packet from 10.0.0.255,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.0.255 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched with --return-nomatch
+0 ./check_klog.sh 10.0.0.255 tcp 1025 test-nomatch
+# Send probe packet from 10.0.1.0,tcp:1025
+0 sendip -p ipv4 -id 127.0.0.1 -is 10.0.1.0 -p tcp -td 80 -ts 1025 127.0.0.1
+# Check that test set matched
+0 ./check_klog.sh 10.0.1.0 tcp 1025 test
+# Destroy sets and rules
+0 ./iptables.sh inet stop
+# eof
diff --git a/tests/runtest.sh b/tests/runtest.sh
index ff5c492..ad2ac42 100755
--- a/tests/runtest.sh
+++ b/tests/runtest.sh
@@ -22,7 +22,7 @@ add_tests() {
 	# inet|inet6 network
 	if [ $1 = "inet" ]; then
 		cmd=iptables-save
-		add=match_target
+		add="match_target match_flags"
 	else
 		cmd=ip6tables-save
 		add=match_target6