From 1d036d25e5609ba73fee6a88db01c306b140d512 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Wed, 3 Feb 2016 18:02:17 -0500 Subject: [PATCH 1/1] 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: Willem de Bruijn Signed-off-by: David S. Miller --- net/packet/af_packet.c | 53 +++++++++++++++++++++++++++++------------- 1 file changed, 37 insertions(+), 16 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 89377bf283c8..b7e7851ddc5d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -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 @@ tpacket_error: } } + 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, -- 2.20.1