netfilter: nfqueue: enable to get skb->priority

This info could be useful to improve traffic analysis.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/uapi/linux/netfilter/nfnetlink_queue.h

@@ -61,6 +61,7 @@ enum nfqnl_attr_type {
 	NFQA_SECCTX,			/* security context string */
 	NFQA_VLAN,			/* nested attribute: packet vlan info */
 	NFQA_L2HDR,			/* full L2 header */
+	NFQA_PRIORITY,			/* skb->priority */
 
 	__NFQA_MAX
 };

net/netfilter/nfnetlink_queue.c

@@ -402,6 +402,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
 #endif
 		+ nla_total_size(sizeof(u_int32_t))	/* mark */
+		+ nla_total_size(sizeof(u_int32_t))	/* priority */
 		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
 		+ nla_total_size(sizeof(u_int32_t))	/* skbinfo */
 		+ nla_total_size(sizeof(u_int32_t));	/* cap_len */
@@ -559,6 +560,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	    nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
 		goto nla_put_failure;
 
+	if (entskb->priority &&
+	    nla_put_be32(skb, NFQA_PRIORITY, htonl(entskb->priority)))
+		goto nla_put_failure;
+
 	if (indev && entskb->dev &&
 	    skb_mac_header_was_set(entskb) &&
 	    skb_mac_header_len(entskb) != 0) {