From: Ben Pfaff <blp@nicira.com>
Date: Tue, 11 Nov 2008 21:57:07 +0000 (-0800)
Subject: When a packet arrives via bridging, clone it if it is shared.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cdbc9a4a817238ae484066d43eb6a0a322e31866;p=openvswitch

When a packet arrives via bridging, clone it if it is shared.

Otherwise we will mangle the packet for anyone who came before us
(e.g. tcpdump via AF_PACKET).
---

diff --git a/datapath/datapath.c b/datapath/datapath.c
index d27a9bc1..e9d51a8d 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -455,6 +455,14 @@ static int dp_maint_func(void *data)
 static void
 do_port_input(struct net_bridge_port *p, struct sk_buff *skb) 
 {
+	/* Make our own copy of the packet.  Otherwise we will mangle the
+	 * packet for anyone who came before us (e.g. tcpdump via AF_PACKET).
+	 * (No one comes after us, since we tell handle_bridge() that we took
+	 * the packet.) */
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
 #ifdef SUPPORT_SNAT
 	/* Check if this packet needs early SNAT processing. */
 	if (snat_pre_route(skb)) {