static void virtio_net_receive(void *opaque, const uint8_t *buf, size_t 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; if (!receive_filter(n, buf, 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); }