netfilter: ipset: Add skbinfo extension kernel support in the ipset core.

Skbinfo extension provides mapping of metainformation with lookup in the ipset tables.
This patch defines the flags, the constants, the functions and the structures
for the data type independent support of the extension.
Note the firewall mark stores in the kernel structures as two 32bit values,
but transfered through netlink as one 64bit value.

Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h
index 96afc29..b97aac5 100644
--- a/include/linux/netfilter/ipset/ip_set.h
+++ b/include/linux/netfilter/ipset/ip_set.h
@@ -57,6 +57,8 @@
 	IPSET_EXT_COUNTER = (1 << IPSET_EXT_BIT_COUNTER),
 	IPSET_EXT_BIT_COMMENT = 2,
 	IPSET_EXT_COMMENT = (1 << IPSET_EXT_BIT_COMMENT),
+	IPSET_EXT_BIT_SKBINFO = 3,
+	IPSET_EXT_SKBINFO = (1 << IPSET_EXT_BIT_SKBINFO),
 	/* Mark set with an extension which needs to call destroy */
 	IPSET_EXT_BIT_DESTROY = 7,
 	IPSET_EXT_DESTROY = (1 << IPSET_EXT_BIT_DESTROY),
@@ -65,12 +67,14 @@
 #define SET_WITH_TIMEOUT(s)	((s)->extensions & IPSET_EXT_TIMEOUT)
 #define SET_WITH_COUNTER(s)	((s)->extensions & IPSET_EXT_COUNTER)
 #define SET_WITH_COMMENT(s)	((s)->extensions & IPSET_EXT_COMMENT)
+#define SET_WITH_SKBINFO(s)	((s)->extensions & IPSET_EXT_SKBINFO)
 #define SET_WITH_FORCEADD(s)	((s)->flags & IPSET_CREATE_FLAG_FORCEADD)
 
 /* Extension id, in size order */
 enum ip_set_ext_id {
 	IPSET_EXT_ID_COUNTER = 0,
 	IPSET_EXT_ID_TIMEOUT,
+	IPSET_EXT_ID_SKBINFO,
 	IPSET_EXT_ID_COMMENT,
 	IPSET_EXT_ID_MAX,
 };
@@ -92,6 +96,10 @@
 	u64 packets;
 	u64 bytes;
 	u32 timeout;
+	u32 skbmark;
+	u32 skbmarkmask;
+	u32 skbprio;
+	u16 skbqueue;
 	char *comment;
 };
 
@@ -104,6 +112,13 @@
 	char *str;
 };
 
+struct ip_set_skbinfo {
+	u32 skbmark;
+	u32 skbmarkmask;
+	u32 skbprio;
+	u16 skbqueue;
+};
+
 struct ip_set;
 
 #define ext_timeout(e, s)	\
@@ -112,7 +127,8 @@
 (struct ip_set_counter *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_COUNTER])
 #define ext_comment(e, s)	\
 (struct ip_set_comment *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_COMMENT])
-
+#define ext_skbinfo(e, s)	\
+(struct ip_set_skbinfo *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_SKBINFO])
 
 typedef int (*ipset_adtfn)(struct ip_set *set, void *value,
 			   const struct ip_set_ext *ext,
@@ -256,6 +272,8 @@
 		cadt_flags |= IPSET_FLAG_WITH_COUNTERS;
 	if (SET_WITH_COMMENT(set))
 		cadt_flags |= IPSET_FLAG_WITH_COMMENT;
+	if (SET_WITH_SKBINFO(set))
+		cadt_flags |= IPSET_FLAG_WITH_SKBINFO;
 	if (SET_WITH_FORCEADD(set))
 		cadt_flags |= IPSET_FLAG_WITH_FORCEADD;
 
@@ -304,6 +322,39 @@
 	}
 }
 
+static inline void
+ip_set_get_skbinfo(struct ip_set_skbinfo *skbinfo,
+		      const struct ip_set_ext *ext,
+		      struct ip_set_ext *mext, u32 flags)
+{
+		mext->skbmark = skbinfo->skbmark;
+		mext->skbmarkmask = skbinfo->skbmarkmask;
+		mext->skbprio = skbinfo->skbprio;
+		mext->skbqueue = skbinfo->skbqueue;
+}
+static inline bool
+ip_set_put_skbinfo(struct sk_buff *skb, struct ip_set_skbinfo *skbinfo)
+{
+	return nla_put_net64(skb, IPSET_ATTR_SKBMARK,
+			     cpu_to_be64((u64)skbinfo->skbmark << 32 |
+					 skbinfo->skbmarkmask)) ||
+	       nla_put_net32(skb, IPSET_ATTR_SKBPRIO,
+			     cpu_to_be32(skbinfo->skbprio)) ||
+	       nla_put_net16(skb, IPSET_ATTR_SKBQUEUE,
+			     cpu_to_be16(skbinfo->skbqueue));
+
+}
+
+static inline void
+ip_set_init_skbinfo(struct ip_set_skbinfo *skbinfo,
+		    const struct ip_set_ext *ext)
+{
+	skbinfo->skbmark = ext->skbmark;
+	skbinfo->skbmarkmask = ext->skbmarkmask;
+	skbinfo->skbprio = ext->skbprio;
+	skbinfo->skbqueue = ext->skbqueue;
+}
+
 static inline bool
 ip_set_put_counter(struct sk_buff *skb, struct ip_set_counter *counter)
 {
@@ -497,6 +548,9 @@
 	if (SET_WITH_COMMENT(set) &&
 	    ip_set_put_comment(skb, ext_comment(e, set)))
 		return -EMSGSIZE;
+	if (SET_WITH_SKBINFO(set) &&
+	    ip_set_put_skbinfo(skb, ext_skbinfo(e, set)))
+		return -EMSGSIZE;
 	return 0;
 }