commit 682f048bd49449f4ab978664a7f69a44a74e3caa
author Alexander Drozdov <al.drozdov@gmail.com> Mon Mar 23 09:11:13 2015 +0300
committer David S. Miller <davem@davemloft.net> Mon Mar 23 22:01:28 2015 -0400
tree 4b623e8ddd2e4f874947e3c9f128591661dd10e8
parent 68c2e5de360411674d9821ee2b46f5d8ee965161

af_packet: pass checksum validation status to the user

Introduce TP_STATUS_CSUM_VALID tp_status flag to tell the
af_packet user that at least the transport header checksum
has been already validated.

For now, the flag may be set for incoming packets only.

Signed-off-by: Alexander Drozdov <al.drozdov@gmail.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet/af_packet.c

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 9d854c5..5102c3c 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1924,6 +1924,10 @@
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL)
 		status |= TP_STATUS_CSUMNOTREADY;
+	else if (skb->pkt_type != PACKET_OUTGOING &&
+		 (skb->ip_summed == CHECKSUM_COMPLETE ||
+		  skb_csum_unnecessary(skb)))
+		status |= TP_STATUS_CSUM_VALID;
 
 	if (snaplen > res)
 		snaplen = res;
@@ -3031,6 +3035,11 @@
 		aux.tp_status = TP_STATUS_USER;
 		if (skb->ip_summed == CHECKSUM_PARTIAL)
 			aux.tp_status |= TP_STATUS_CSUMNOTREADY;
+		else if (skb->pkt_type != PACKET_OUTGOING &&
+			 (skb->ip_summed == CHECKSUM_COMPLETE ||
+			  skb_csum_unnecessary(skb)))
+			aux.tp_status |= TP_STATUS_CSUM_VALID;
+
 		aux.tp_len = origlen;
 		aux.tp_snaplen = skb->len;
 		aux.tp_mac = 0;