Commit 190563f9 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Stefan Hajnoczi
Browse files

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: default avatarStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
parent f237ddbb

hw/usb/dev-network.c

+16 −3
Original line number Diff line number Diff line
@@ -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;