netfilter: nfnetlink_log: send complete hardware header

This patch adds some fields to NFLOG to be able to send the complete
hardware header with all necessary informations.
It sends to userspace:
 * the type of hardware link
 * the lenght of hardware header
 * the hardware header
Signed-off-by: Eric Leblond <eric@inl.fr>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter/nfnetlink_log.h

@@ -48,6 +48,9 @@ enum nfulnl_attr_type {
 	NFULA_SEQ,			/* instance-local sequence number */
 	NFULA_SEQ_GLOBAL,		/* global sequence number */
 	NFULA_GID,			/* group id of socket */
+	NFULA_HWTYPE,			/* hardware type */
+	NFULA_HWHEADER,			/* hardware header */
+	NFULA_HWLEN,			/* hardware header length */
 
 	__NFULA_MAX
 };

net/netfilter/nfnetlink_log.c

@@ -453,6 +453,14 @@ __build_packet_message(struct nfulnl_instance *inst,
 		}
 	}
 
+	if (indev && skb_mac_header_was_set(skb)) {
+		NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
+		NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
+			     htons(skb->dev->hard_header_len));
+		NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
+			skb_mac_header(skb));
+	}
+
 	if (skb->tstamp.tv64) {
 		struct nfulnl_msg_packet_timestamp ts;
 		struct timeval tv = ktime_to_timeval(skb->tstamp);