[SECMARK]: Add secmark support to conntrack

Add a secmark field to IP and NF conntracks, so that security markings
on packets can be copied to their associated connections, and also
copied back to packets as required.  This is similar to the network
mark field currently used with conntrack, although it is intended for
enforcement of security policy rather than network policy.
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter_ipv4/ip_conntrack.h

@@ -121,6 +121,10 @@ struct ip_conntrack
 	u_int32_t mark;
 #endif
 
+#ifdef CONFIG_IP_NF_CONNTRACK_SECMARK
+	u_int32_t secmark;
+#endif
+
 	/* Traversed often, so hopefully in different cacheline to top */
 	/* These are my tuples; original and reply */
 	struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];

include/net/netfilter/nf_conntrack.h

@@ -114,6 +114,10 @@ struct nf_conn
 	u_int32_t mark;
 #endif
 
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+	u_int32_t secmark;
+#endif
+
 	/* Storage reserved for other modules: */
 	union nf_conntrack_proto proto;
 

include/net/netfilter/nf_conntrack_compat.h

@@ -20,6 +20,19 @@ static inline u_int32_t *nf_ct_get_mark(const struct sk_buff *skb,
 }
 #endif /* CONFIG_IP_NF_CONNTRACK_MARK */
 
+#ifdef CONFIG_IP_NF_CONNTRACK_SECMARK
+static inline u_int32_t *nf_ct_get_secmark(const struct sk_buff *skb,
+					   u_int32_t *ctinfo)
+{
+	struct ip_conntrack *ct = ip_conntrack_get(skb, ctinfo);
+
+	if (ct)
+		return &ct->secmark;
+	else
+		return NULL;
+}
+#endif /* CONFIG_IP_NF_CONNTRACK_SECMARK */
+
 #ifdef CONFIG_IP_NF_CT_ACCT
 static inline struct ip_conntrack_counter *
 nf_ct_get_counters(const struct sk_buff *skb)
@@ -70,6 +83,19 @@ static inline u_int32_t *nf_ct_get_mark(const struct sk_buff *skb,
 }
 #endif /* CONFIG_NF_CONNTRACK_MARK */
 
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+static inline u_int32_t *nf_ct_get_secmark(const struct sk_buff *skb,
+					   u_int32_t *ctinfo)
+{
+	struct nf_conn *ct = nf_ct_get(skb, ctinfo);
+
+	if (ct)
+		return &ct->secmark;
+	else
+		return NULL;
+}
+#endif /* CONFIG_NF_CONNTRACK_MARK */
+
 #ifdef CONFIG_NF_CT_ACCT
 static inline struct ip_conntrack_counter *
 nf_ct_get_counters(const struct sk_buff *skb)

net/ipv4/netfilter/Kconfig

@@ -55,6 +55,18 @@ config IP_NF_CONNTRACK_MARK
 	  of packets, but this mark value is kept in the conntrack session
 	  instead of the individual packets.
 	
+config IP_NF_CONNTRACK_SECMARK
+	bool  'Connection tracking security mark support'
+	depends on IP_NF_CONNTRACK && NETWORK_SECMARK
+	help
+	  This option enables security markings to be applied to
+	  connections.  Typically they are copied to connections from
+	  packets using the CONNSECMARK target and copied back from
+	  connections to packets with the same target, with the packets
+	  being originally labeled via SECMARK.
+
+	  If unsure, say 'N'.
+
 config IP_NF_CONNTRACK_EVENTS
 	bool "Connection tracking events (EXPERIMENTAL)"
 	depends on EXPERIMENTAL && IP_NF_CONNTRACK

net/ipv4/netfilter/ip_conntrack_core.c

@@ -723,6 +723,9 @@ init_conntrack(struct ip_conntrack_tuple *tuple,
     defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
 		/* this is ugly, but there is no other place where to put it */
 		conntrack->nat.masq_index = exp->master->nat.masq_index;
+#endif
+#ifdef CONFIG_IP_NF_CONNTRACK_SECMARK
+		conntrack->secmark = exp->master->secmark;
 #endif
 		nf_conntrack_get(&conntrack->master->ct_general);
 		CONNTRACK_STAT_INC(expect_new);

net/ipv4/netfilter/ip_conntrack_standalone.c

@@ -189,6 +189,11 @@ static int ct_seq_show(struct seq_file *s, void *v)
 		return -ENOSPC;
 #endif
 
+#ifdef CONFIG_IP_NF_CONNTRACK_SECMARK
+	if (seq_printf(s, "secmark=%u ", conntrack->secmark))
+		return -ENOSPC;
+#endif
+
 	if (seq_printf(s, "use=%u\n", atomic_read(&conntrack->ct_general.use)))
 		return -ENOSPC;
 

net/netfilter/Kconfig

@@ -60,6 +60,18 @@ config NF_CONNTRACK_MARK
 	  of packets, but this mark value is kept in the conntrack session
 	  instead of the individual packets.
 
+config NF_CONNTRACK_SECMARK
+	bool  'Connection tracking security mark support'
+	depends on NF_CONNTRACK && NETWORK_SECMARK
+	help
+	  This option enables security markings to be applied to
+	  connections.  Typically they are copied to connections from
+	  packets using the CONNSECMARK target and copied back from
+	  connections to packets with the same target, with the packets
+	  being originally labeled via SECMARK.
+
+	  If unsure, say 'N'.
+
 config NF_CONNTRACK_EVENTS
 	bool "Connection tracking events (EXPERIMENTAL)"
 	depends on EXPERIMENTAL && NF_CONNTRACK

net/netfilter/nf_conntrack_core.c

@@ -989,6 +989,9 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
 		conntrack->master = exp->master;
 #ifdef CONFIG_NF_CONNTRACK_MARK
 		conntrack->mark = exp->master->mark;
+#endif
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+		conntrack->secmark = exp->master->secmark;
 #endif
 		nf_conntrack_get(&conntrack->master->ct_general);
 		NF_CT_STAT_INC(expect_new);

net/netfilter/nf_conntrack_standalone.c

@@ -213,6 +213,11 @@ static int ct_seq_show(struct seq_file *s, void *v)
 		return -ENOSPC;
 #endif
 
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+	if (seq_printf(s, "secmark=%u ", conntrack->secmark))
+		return -ENOSPC;
+#endif
+
 	if (seq_printf(s, "use=%u\n", atomic_read(&conntrack->ct_general.use)))
 		return -ENOSPC;