[PATCH 11/17] net: drop packet from tap device if all NICs are down

From: Anthony Liguori <aliguori@us.ibm.com>
To: kvm@vger.kernel.org
Cc: Glauber Costa <glommer@gmail.com>,
	Mark McLoughlin <markmc@redhat.com>, Avi Kivity <avi@redhat.com>,
	Anthony Liguori <aliguori@us.ibm.com>
Subject: [PATCH 11/17] net: drop packet from tap device if all NICs are down
Date: Sun, 17 May 2009 10:43:13 -0500	[thread overview]
Message-ID: <1242574999-20887-13-git-send-email-aliguori@us.ibm.com> (raw)
In-Reply-To: <1242574999-20887-1-git-send-email-aliguori@us.ibm.com>

From: Mark McLoughlin <markmc@redhat.com>

If you do e.g. "set_link virtio.0 down" and there are packets
pending on the tap interface, we currently buffer a packet
and constantly try and send it until the link is up again.

We actually just want to drop the packet if the NIC is down.
Upstream qemu already does this, we just differ because we
buffer packets from the tap interface.

[aliguori: rebased this patch on stable]

Reported-by: Yan Vugenfirer <yvugenfi@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/net.c b/net.c
index d8fb759..ef3a965 100644
--- a/net.c
+++ b/net.c
@@ -414,8 +414,10 @@ int qemu_send_packet(VLANClientState *vc1, const uint8_t *buf, int size)
     hex_dump(stdout, buf, size);
 #endif
     for(vc = vlan->first_client; vc != NULL; vc = vc->next) {
-        if (vc != vc1 && !vc->link_down) {
-            if (!vc->fd_can_read || vc->fd_can_read(vc->opaque)) {
+        if (vc != vc1) {
+            if (vc->link_down) {
+                ret = 0;
+            } else  if (!vc->fd_can_read || vc->fd_can_read(vc->opaque)) {
                 vc->fd_read(vc->opaque, buf, size);
                 ret = 0;
             }
-- 
1.6.0.6

