From 14294fa1c903ab239bce3d2839e9e1883141b4f1 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 24 Aug 2012 13:37:29 +0100 Subject: [PATCH] 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 (cherry picked from commit 190563f9a90c9df8ad32fc7f3e4b166deda949a6) Signed-off-by: Michael Roth --- hw/usb/dev-network.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c index 0b5cb71..e4a4359 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; -- 1.8.0.2