[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>

3 files changed, 20 insertions, 0 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index ff4b118f14a9..e1d7f5fbc526 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/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
diff --git a/net/ipv4/netfilter/ip_conntrack_core.c b/net/ipv4/netfilter/ip_conntrack_core.c
index 4fe9e69378df..7e4cf9a4d15f 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -724,6 +724,9 @@ init_conntrack(struct ip_conntrack_tuple *tuple,
                 /* 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);
         } else {
diff --git a/net/ipv4/netfilter/ip_conntrack_standalone.c b/net/ipv4/netfilter/ip_conntrack_standalone.c
index 6cb9b989d14c..88445aac3f28 100644
--- a/net/ipv4/netfilter/ip_conntrack_standalone.c
+++ b/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;