Commit 4b0bf10e authored by Arseniy Krasnov's avatar Arseniy Krasnov Committed by Paolo Abeni
Browse files

vsock/virtio: non-linear skb handling for tap 



For tap device new skb is created and data from the current skb is
copied to it. This adds copying data from non-linear skb to new
the skb.

Signed-off-by: default avatarArseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 64c99d2d

net/vmw_vsock/virtio_transport_common.c

+28 −3
Original line number Diff line number Diff line
@@ -106,6 +106,27 @@ virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info, 
	return NULL;

}



static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,

						void *dst,

						size_t len)

{

	struct iov_iter iov_iter = { 0 };

	struct kvec kvec;

	size_t to_copy;



	kvec.iov_base = dst;

	kvec.iov_len = len;



	iov_iter.iter_type = ITER_KVEC;

	iov_iter.kvec = &kvec;

	iov_iter.nr_segs = 1;



	to_copy = min_t(size_t, len, skb->len);



	skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,

			       &iov_iter, to_copy);

}



/* Packet capture */

static struct sk_buff *virtio_transport_build_skb(void *opaque)

{
@@ -114,7 +135,6 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) 
	struct af_vsockmon_hdr *hdr;

	struct sk_buff *skb;

	size_t payload_len;

	void *payload_buf;



	/* A packet could be split to fit the RX buffer, so we can retrieve

	 * the payload length from the header and the buffer pointer taking
@@ -122,7 +142,6 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) 
	 */

	pkt_hdr = virtio_vsock_hdr(pkt);

	payload_len = pkt->len;

	payload_buf = pkt->data;



	skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len,

			GFP_ATOMIC);
@@ -165,7 +184,13 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) 
	skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr));



	if (payload_len) {

		skb_put_data(skb, payload_buf, payload_len);

		if (skb_is_nonlinear(pkt)) {

			void *data = skb_put(skb, payload_len);



			virtio_transport_copy_nonlinear_skb(pkt, data, payload_len);

		} else {

			skb_put_data(skb, pkt->data, payload_len);

		}

	}



	return skb;