[NETFILTER]: {ip,ip6}t_LOG: print MARK value in log output

Dump the mark value in log messages similar to nfnetlink_log. This
is useful for debugging complex setups where marks are used for
routing or traffic classification.
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/ipv4/netfilter/ipt_LOG.c

@@ -338,12 +338,16 @@ static void dump_packet(const struct nf_loginfo *info,
 	if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
 		read_lock_bh(&skb->sk->sk_callback_lock);
 		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
-			printk("UID=%u GID=%u",
+			printk("UID=%u GID=%u ",
 				skb->sk->sk_socket->file->f_uid,
 				skb->sk->sk_socket->file->f_gid);
 		read_unlock_bh(&skb->sk->sk_callback_lock);
 	}
 
+	/* Max length: 16 "MARK=0xFFFFFFFF " */
+	if (!iphoff && skb->mark)
+		printk("MARK=0x%x ", skb->mark);
+
 	/* Proto    Max log string length */
 	/* IP:      40+46+6+11+127 = 230 */
 	/* TCP:     10+max(25,20+30+13+9+32+11+127) = 252 */

net/ipv6/netfilter/ip6t_LOG.c

@@ -363,11 +363,15 @@ static void dump_packet(const struct nf_loginfo *info,
 	if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) {
 		read_lock_bh(&skb->sk->sk_callback_lock);
 		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
-			printk("UID=%u GID=%u",
+			printk("UID=%u GID=%u ",
 				skb->sk->sk_socket->file->f_uid,
 				skb->sk->sk_socket->file->f_gid);
 		read_unlock_bh(&skb->sk->sk_callback_lock);
 	}
+
+	/* Max length: 16 "MARK=0xFFFFFFFF " */
+	if (!recurse && skb->mark)
+		printk("MARK=0x%x ", skb->mark);
 }
 
 static struct nf_loginfo default_loginfo = {