net: Fix send queue ordering

Ensure that packets enqueued for delayed delivery are dequeued in FIFO
order. At least one simplistic guest TCP/IP stack became unhappy due to
sporadically reordered packet streams.

At this chance, switch the send queue implementation to TAILQ.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/net.h b/net.h
index 3ac9e8c968..bab02f5de9 100644
--- a/net.h
+++ b/net.h
@@ -1,6 +1,7 @@
 #ifndef QEMU_NET_H
 #define QEMU_NET_H
 
+#include "sys-queue.h"
 #include "qemu-common.h"
 
 /* VLANs support */
@@ -35,7 +36,7 @@ typedef struct VLANPacket VLANPacket;
 typedef void (NetPacketSent) (VLANClientState *, ssize_t);
 
 struct VLANPacket {
-    struct VLANPacket *next;
+    TAILQ_ENTRY(VLANPacket) entry;
     VLANClientState *sender;
     int size;
     NetPacketSent *sent_cb;
@@ -47,7 +48,7 @@ struct VLANState {
     VLANClientState *first_client;
     struct VLANState *next;
     unsigned int nb_guest_devs, nb_host_devs;
-    VLANPacket *send_queue;
+    TAILQ_HEAD(send_queue, VLANPacket) send_queue;
     int delivering;
 };