Commit 58d19b19 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

packet: vnet_hdr support for tpacket_rcv 



Support socket option PACKET_VNET_HDR together with PACKET_RX_RING.
When enabled, a struct virtio_net_hdr will precede the data in the
packet ring slots.

Verified with test program at
github.com/wdebruij/kerneltools/blob/master/tests/psock_rxring_vnet.c

  pkt: 1454269209.798420 len=5066
  vnet: gso_type=tcpv4 gso_size=1448 hlen=66 ecn=off
  csum: start=34 off=16
  eth: proto=0x800
  ip: src=<masked> dst=<masked> proto=6 len=5052

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 16cc1400

net/packet/af_packet.c

+15 −4
Original line number Diff line number Diff line
@@ -2207,6 +2207,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 
		netoff = TPACKET_ALIGN(po->tp_hdrlen +

				       (maclen < 16 ? 16 : maclen)) +

				       po->tp_reserve;

		if (po->has_vnet_hdr)

			netoff += sizeof(struct virtio_net_hdr);

		macoff = netoff - maclen;

	}

	if (po->tp_version <= TPACKET_V2) {
@@ -2243,7 +2245,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 
	h.raw = packet_current_rx_frame(po, skb,

					TP_STATUS_KERNEL, (macoff+snaplen));

	if (!h.raw)

		goto ring_is_full;

		goto drop_n_account;

	if (po->tp_version <= TPACKET_V2) {

		packet_increment_rx_head(po, &po->rx_ring);

	/*
@@ -2262,6 +2264,14 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 
	}

	spin_unlock(&sk->sk_receive_queue.lock);



	if (po->has_vnet_hdr) {

		if (__packet_rcv_vnet(skb, h.raw + macoff -

					   sizeof(struct virtio_net_hdr))) {

			spin_lock(&sk->sk_receive_queue.lock);

			goto drop_n_account;

		}

	}



	skb_copy_bits(skb, 0, h.raw + macoff, snaplen);



	if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
@@ -2357,7 +2367,7 @@ drop: 
	kfree_skb(skb);

	return 0;



ring_is_full:

drop_n_account:

	po->stats.stats1.tp_drops++;

	spin_unlock(&sk->sk_receive_queue.lock);
@@ -3587,7 +3597,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv 
		}

		if (optlen < len)

			return -EINVAL;

		if (pkt_sk(sk)->has_vnet_hdr)

		if (pkt_sk(sk)->has_vnet_hdr &&

		    optname == PACKET_TX_RING)

			return -EINVAL;

		if (copy_from_user(&req_u.req, optval, len))

			return -EFAULT;

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