--- ../orig/net/queue.c	2012-12-03 11:37:05.000000000 -0800
+++ ./net/queue.c	2013-01-16 21:37:20.109732443 -0800
@@ -50,6 +50,8 @@ struct NetPacket {
 
 struct NetQueue {
     void *opaque;
+    uint32_t nq_maxlen;
+    uint32_t nq_count;
 
     QTAILQ_HEAD(packets, NetPacket) packets;
 
@@ -63,6 +65,8 @@ NetQueue *qemu_new_net_queue(void *opaqu
     queue = g_malloc0(sizeof(NetQueue));
 
     queue->opaque = opaque;
+    queue->nq_maxlen = 10000; /* arbitrary limit */
+    queue->nq_count = 0;
 
     QTAILQ_INIT(&queue->packets);
 
@@ -92,6 +96,8 @@ static void qemu_net_queue_append(NetQue
 {
     NetPacket *packet;
 
+    if (!sent_cb || queue->nq_count >= queue->nq_maxlen)
+	return;
     packet = g_malloc(sizeof(NetPacket) + size);
     packet->sender = sender;
     packet->flags = flags;
@@ -99,6 +105,7 @@ static void qemu_net_queue_append(NetQue
     packet->sent_cb = sent_cb;
     memcpy(packet->data, buf, size);
 
+    queue->nq_count++;
     QTAILQ_INSERT_TAIL(&queue->packets, packet, entry);
 }
 
@@ -113,6 +120,8 @@ static void qemu_net_queue_append_iov(Ne
     size_t max_len = 0;
     int i;
 
+    if (!sent_cb || queue->nq_count >= queue->nq_maxlen)
+	return;
     for (i = 0; i < iovcnt; i++) {
         max_len += iov[i].iov_len;
     }
@@ -130,6 +139,7 @@ static void qemu_net_queue_append_iov(Ne
         packet->size += len;
     }
 
+    queue->nq_count++;
     QTAILQ_INSERT_TAIL(&queue->packets, packet, entry);
 }
 
@@ -220,6 +230,7 @@ void qemu_net_queue_purge(NetQueue *queu
     QTAILQ_FOREACH_SAFE(packet, &queue->packets, entry, next) {
         if (packet->sender == from) {
             QTAILQ_REMOVE(&queue->packets, packet, entry);
+            queue->nq_count--;
             g_free(packet);
         }
     }
@@ -233,6 +244,7 @@ bool qemu_net_queue_flush(NetQueue *queu
 
         packet = QTAILQ_FIRST(&queue->packets);
         QTAILQ_REMOVE(&queue->packets, packet, entry);
+        queue->nq_count--;
 
         ret = qemu_net_queue_deliver(queue,
                                      packet->sender,
@@ -240,6 +252,7 @@ bool qemu_net_queue_flush(NetQueue *queu
                                      packet->data,
                                      packet->size);
         if (ret == 0) {
+            queue->nq_count++;
             QTAILQ_INSERT_HEAD(&queue->packets, packet, entry);
             return false;
         }