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Commit 1d036d25 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

packet: tpacket_snd gso and checksum offload 



Support socket option PACKET_VNET_HDR together with PACKET_TX_RING.

When enabled, a struct virtio_net_hdr is expected to precede the data
in the ring. The vnet option must be set before the ring is created.

The implementation reuses the existing skb_copy_bits code that is used
when dev->hard_header_len is non-zero. Move this ll_header check to
before the skb alloc and combine it with a test for vnet_hdr->hdr_len.
Allocate and copy the max of the two.

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

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8d39b4a6

net/packet/af_packet.c

+37 −16
Original line number Diff line number Diff line
@@ -2495,7 +2495,7 @@ static int packet_snd_vnet_gso(struct sk_buff *skb, 


static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,

		void *frame, struct net_device *dev, void *data, int tp_len,

		__be16 proto, unsigned char *addr, int hlen)

		__be16 proto, unsigned char *addr, int hlen, int copylen)

{

	union tpacket_uhdr ph;

	int to_write, offset, len, nr_frags, len_max;
@@ -2522,20 +2522,17 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, 
				NULL, tp_len);

		if (unlikely(err < 0))

			return -EINVAL;

	} else if (dev->hard_header_len) {

		if (ll_header_truncated(dev, tp_len))

			return -EINVAL;



	} else if (copylen) {

		skb_push(skb, dev->hard_header_len);

		err = skb_store_bits(skb, 0, data,

				dev->hard_header_len);

		skb_put(skb, copylen - dev->hard_header_len);

		err = skb_store_bits(skb, 0, data, copylen);

		if (unlikely(err))

			return err;

		if (!skb->protocol)

			tpacket_set_protocol(dev, skb);



		data += dev->hard_header_len;

		to_write -= dev->hard_header_len;

		data += copylen;

		to_write -= copylen;

	}



	offset = offset_in_page(data);
@@ -2631,6 +2628,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
{

	struct sk_buff *skb;

	struct net_device *dev;

	struct virtio_net_hdr *vnet_hdr = NULL;

	__be16 proto;

	int err, reserve = 0;

	void *ph;
@@ -2641,7 +2639,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
	void *data;

	int len_sum = 0;

	int status = TP_STATUS_AVAILABLE;

	int hlen, tlen;

	int hlen, tlen, copylen = 0;



	mutex_lock(&po->pg_vec_lock);
@@ -2674,7 +2672,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
	size_max = po->tx_ring.frame_size

		- (po->tp_hdrlen - sizeof(struct sockaddr_ll));



	if (size_max > dev->mtu + reserve + VLAN_HLEN)

	if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)

		size_max = dev->mtu + reserve + VLAN_HLEN;



	do {
@@ -2694,8 +2692,28 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
		status = TP_STATUS_SEND_REQUEST;

		hlen = LL_RESERVED_SPACE(dev);

		tlen = dev->needed_tailroom;

		if (po->has_vnet_hdr) {

			vnet_hdr = data;

			data += sizeof(*vnet_hdr);

			tp_len -= sizeof(*vnet_hdr);

			if (tp_len < 0 ||

			    __packet_snd_vnet_parse(vnet_hdr, tp_len)) {

				tp_len = -EINVAL;

				goto tpacket_error;

			}

			copylen = __virtio16_to_cpu(vio_le(),

						    vnet_hdr->hdr_len);

		}

		if (dev->hard_header_len) {

			if (ll_header_truncated(dev, tp_len)) {

				tp_len = -EINVAL;

				goto tpacket_error;

			}

			copylen = max_t(int, copylen, dev->hard_header_len);

		}

		skb = sock_alloc_send_skb(&po->sk,

				hlen + tlen + sizeof(struct sockaddr_ll),

				hlen + tlen + sizeof(struct sockaddr_ll) +

				(copylen - dev->hard_header_len),

				!need_wait, &err);



		if (unlikely(skb == NULL)) {
@@ -2705,9 +2723,10 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
			goto out_status;

		}

		tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,

					  addr, hlen);

					  addr, hlen, copylen);

		if (likely(tp_len >= 0) &&

		    tp_len > dev->mtu + reserve &&

		    !po->has_vnet_hdr &&

		    !packet_extra_vlan_len_allowed(dev, skb))

			tp_len = -EMSGSIZE;
@@ -2726,6 +2745,11 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) 
			}

		}



		if (po->has_vnet_hdr && packet_snd_vnet_gso(skb, vnet_hdr)) {

			tp_len = -EINVAL;

			goto tpacket_error;

		}



		packet_pick_tx_queue(dev, skb);



		skb->destructor = tpacket_destruct_skb;
@@ -3616,9 +3640,6 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv 
		}

		if (optlen < len)

			return -EINVAL;

		if (pkt_sk(sk)->has_vnet_hdr &&

		    optname == PACKET_TX_RING)

			return -EINVAL;

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

			return -EFAULT;

		return packet_set_ring(sk, &req_u, 0,