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authorStefan Hajnoczi <stefanha@linux.vnet.ibm.com>2012-08-24 13:37:29 +0100
committerStefan Hajnoczi <stefanha@gmail.com>2012-09-14 08:40:32 +0100
commit190563f9a90c9df8ad32fc7f3e4b166deda949a6 (patch)
treeca63d94cd6b874adb7cf79b4070fab496a6f7c0b /hw/usb/dev-network.c
parentf237ddbb89142c6948a2257c459e49dee7500a7c (diff)
net: fix usbnet_receive() packet drops
The USB network interface has a single buffer which the guest reads from. This patch prevents multiple calls to usbnet_receive() from clobbering the input buffer. Instead we queue packets until buffer space becomes available again. This is inspired by virtio-net and e1000 rxbuf handling. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Diffstat (limited to 'hw/usb/dev-network.c')
-rw-r--r--hw/usb/dev-network.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c
index 0b5cb71f98..e4a43599b5 100644
--- a/hw/usb/dev-network.c
+++ b/hw/usb/dev-network.c
@@ -1001,6 +1001,13 @@ static int rndis_keepalive_response(USBNetState *s,
return 0;
}
+/* Prepare to receive the next packet */
+static void usb_net_reset_in_buf(USBNetState *s)
+{
+ s->in_ptr = s->in_len = 0;
+ qemu_flush_queued_packets(&s->nic->nc);
+}
+
static int rndis_parse(USBNetState *s, uint8_t *data, int length)
{
uint32_t msg_type;
@@ -1025,7 +1032,8 @@ static int rndis_parse(USBNetState *s, uint8_t *data, int length)
case RNDIS_RESET_MSG:
rndis_clear_responsequeue(s);
- s->out_ptr = s->in_ptr = s->in_len = 0;
+ s->out_ptr = 0;
+ usb_net_reset_in_buf(s);
return rndis_reset_response(s, (rndis_reset_msg_type *) data);
case RNDIS_KEEPALIVE_MSG:
@@ -1135,7 +1143,7 @@ static int usb_net_handle_datain(USBNetState *s, USBPacket *p)
int ret = USB_RET_NAK;
if (s->in_ptr > s->in_len) {
- s->in_ptr = s->in_len = 0;
+ usb_net_reset_in_buf(s);
ret = USB_RET_NAK;
return ret;
}
@@ -1152,7 +1160,7 @@ static int usb_net_handle_datain(USBNetState *s, USBPacket *p)
if (s->in_ptr >= s->in_len &&
(is_rndis(s) || (s->in_len & (64 - 1)) || !ret)) {
/* no short packet necessary */
- s->in_ptr = s->in_len = 0;
+ usb_net_reset_in_buf(s);
}
#ifdef TRAFFIC_DEBUG
@@ -1263,6 +1271,11 @@ static ssize_t usbnet_receive(NetClientState *nc, const uint8_t *buf, size_t siz
return -1;
}
+ /* Only accept packet if input buffer is empty */
+ if (s->in_len > 0) {
+ return 0;
+ }
+
if (is_rndis(s)) {
struct rndis_packet_msg_type *msg;