static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)
{
VirtIONet *n = opaque;
struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
size_t hdr_len, offset, i;
if (!do_virtio_net_can_receive(n, size))
return;
/* hdr_len refers to the header we supply to the guest */
hdr_len = n->mergeable_rx_bufs ?
sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
offset = i = 0;
while (offset < size) {
VirtQueueElement elem;
int len, total;
struct iovec sg[VIRTQUEUE_MAX_SIZE];
len = total = 0;
if ((i != 0 && !n->mergeable_rx_bufs) ||
virtqueue_pop(n->rx_vq, &elem) == 0) {
if (i == 0)
return;
fprintf(stderr, "virtio-net truncating packet\n");
exit(1);
}
if (elem.in_num < 1) {
fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
exit(1);
}
if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {
fprintf(stderr, "virtio-net header not in first element\n");
exit(1);
}
memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
if (i == 0) {
if (n->mergeable_rx_bufs)
mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
offset += receive_header(n, sg, elem.in_num,
buf + offset, size - offset, hdr_len);
total += hdr_len;
}
/* copy in packet. ugh */
len = iov_fill(sg, elem.in_num,
buf + offset, size - offset);
total += len;
/* signal other side */
virtqueue_fill(n->rx_vq, &elem, total, i++);
offset += len;
}
if (mhdr)
mhdr->num_buffers = i;
virtqueue_flush(n->rx_vq, i);
virtio_notify(&n->vdev, n->rx_vq);
}
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len)
{
virtqueue_fill(vq, elem, len, 0);
virtqueue_flush(vq, 1);
}
