From bfd5f4a3d605e0f6054df0b59fe0907ff7e696d3 Mon Sep 17 00:00:00 2001 From: Sridhar Samudrala Date: Thu, 4 Feb 2010 20:24:10 -0800 Subject: [PATCH] packet: Add GSO/csum offload support. This patch adds GSO/checksum offload to af_packet sockets using virtio_net_hdr. Based on Rusty's patch to add this support to tun. It allows GSO/checksum offload to be enabled when using raw socket backend with virtio_net. Adds PACKET_VNET_HDR socket option to prepend virtio_net_hdr in the receive path and process/skip virtio_net_hdr in the send path. This option is only allowed with SOCK_RAW sockets attached to ethernet type devices. v2 updates ---------- Michael's Comments - Perform length check in packet_snd() when GSO is off even when vnet_hdr is present. - Check for SKB_GSO_FCOE type and return -EINVAL - don't allow tx/rx ring when vnet_hdr is enabled. Herbert's Comments - Removed ethernet specific code. - protocol value is assumed to be passed in by the caller. Signed-off-by: Sridhar Samudrala Signed-off-by: David S. Miller --- include/linux/if_packet.h | 1 + net/packet/af_packet.c | 187 +++++++++++++++++++++++++++++++++++--- 2 files changed, 177 insertions(+), 11 deletions(-) diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h index 4021d47cc437..aa57a5f993fc 100644 --- a/include/linux/if_packet.h +++ b/include/linux/if_packet.h @@ -46,6 +46,7 @@ struct sockaddr_ll { #define PACKET_RESERVE 12 #define PACKET_TX_RING 13 #define PACKET_LOSS 14 +#define PACKET_VNET_HDR 15 struct tpacket_stats { unsigned int tp_packets; diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 53633c5fdb1d..178e2937bbaa 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -80,6 +80,7 @@ #include #include #include +#include #ifdef CONFIG_INET #include @@ -193,7 +194,8 @@ struct packet_sock { struct mutex pg_vec_lock; unsigned int running:1, /* prot_hook is attached*/ auxdata:1, - origdev:1; + origdev:1, + has_vnet_hdr:1; int ifindex; /* bound device */ __be16 num; struct packet_mclist *mclist; @@ -1056,6 +1058,30 @@ out: } #endif +static inline struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, + size_t reserve, size_t len, + size_t linear, int noblock, + int *err) +{ + struct sk_buff *skb; + + /* Under a page? Don't bother with paged skb. */ + if (prepad + len < PAGE_SIZE || !linear) + linear = len; + + skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, + err); + if (!skb) + return NULL; + + skb_reserve(skb, reserve); + skb_put(skb, linear); + skb->data_len = len - linear; + skb->len += len - linear; + + return skb; +} + static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) { @@ -1066,14 +1092,17 @@ static int packet_snd(struct socket *sock, __be16 proto; unsigned char *addr; int ifindex, err, reserve = 0; + struct virtio_net_hdr vnet_hdr = { 0 }; + int offset = 0; + int vnet_hdr_len; + struct packet_sock *po = pkt_sk(sk); + unsigned short gso_type = 0; /* * Get and verify the address. */ if (saddr == NULL) { - struct packet_sock *po = pkt_sk(sk); - ifindex = po->ifindex; proto = po->num; addr = NULL; @@ -1100,25 +1129,74 @@ static int packet_snd(struct socket *sock, if (!(dev->flags & IFF_UP)) goto out_unlock; + if (po->has_vnet_hdr) { + vnet_hdr_len = sizeof(vnet_hdr); + + err = -EINVAL; + if (len < vnet_hdr_len) + goto out_unlock; + + len -= vnet_hdr_len; + + err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov, + vnet_hdr_len); + if (err < 0) + goto out_unlock; + + if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > + vnet_hdr.hdr_len)) + vnet_hdr.hdr_len = vnet_hdr.csum_start + + vnet_hdr.csum_offset + 2; + + err = -EINVAL; + if (vnet_hdr.hdr_len > len) + goto out_unlock; + + if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { + switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { + case VIRTIO_NET_HDR_GSO_TCPV4: + gso_type = SKB_GSO_TCPV4; + break; + case VIRTIO_NET_HDR_GSO_TCPV6: + gso_type = SKB_GSO_TCPV6; + break; + case VIRTIO_NET_HDR_GSO_UDP: + gso_type = SKB_GSO_UDP; + break; + default: + goto out_unlock; + } + + if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) + gso_type |= SKB_GSO_TCP_ECN; + + if (vnet_hdr.gso_size == 0) + goto out_unlock; + + } + } + err = -EMSGSIZE; - if (len > dev->mtu+reserve) + if (!gso_type && (len > dev->mtu+reserve)) goto out_unlock; - skb = sock_alloc_send_skb(sk, len + LL_ALLOCATED_SPACE(dev), - msg->msg_flags & MSG_DONTWAIT, &err); + err = -ENOBUFS; + skb = packet_alloc_skb(sk, LL_ALLOCATED_SPACE(dev), + LL_RESERVED_SPACE(dev), len, vnet_hdr.hdr_len, + msg->msg_flags & MSG_DONTWAIT, &err); if (skb == NULL) goto out_unlock; - skb_reserve(skb, LL_RESERVED_SPACE(dev)); - skb_reset_network_header(skb); + skb_set_network_header(skb, reserve); err = -EINVAL; if (sock->type == SOCK_DGRAM && - dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len) < 0) + (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0) goto out_free; /* Returns -EFAULT on error */ - err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); + err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len); if (err) goto out_free; @@ -1127,6 +1205,25 @@ static int packet_snd(struct socket *sock, skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; + if (po->has_vnet_hdr) { + if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + if (!skb_partial_csum_set(skb, vnet_hdr.csum_start, + vnet_hdr.csum_offset)) { + err = -EINVAL; + goto out_free; + } + } + + skb_shinfo(skb)->gso_size = vnet_hdr.gso_size; + skb_shinfo(skb)->gso_type = gso_type; + + /* Header must be checked, and gso_segs computed. */ + skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; + skb_shinfo(skb)->gso_segs = 0; + + len += vnet_hdr_len; + } + /* * Now send it */ @@ -1420,6 +1517,7 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, struct sk_buff *skb; int copied, err; struct sockaddr_ll *sll; + int vnet_hdr_len = 0; err = -EINVAL; if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT)) @@ -1451,6 +1549,48 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, if (skb == NULL) goto out; + if (pkt_sk(sk)->has_vnet_hdr) { + struct virtio_net_hdr vnet_hdr = { 0 }; + + err = -EINVAL; + vnet_hdr_len = sizeof(vnet_hdr); + if ((len -= vnet_hdr_len) < 0) + goto out_free; + + if (skb_is_gso(skb)) { + struct skb_shared_info *sinfo = skb_shinfo(skb); + + /* This is a hint as to how much should be linear. */ + vnet_hdr.hdr_len = skb_headlen(skb); + vnet_hdr.gso_size = sinfo->gso_size; + if (sinfo->gso_type & SKB_GSO_TCPV4) + vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; + else if (sinfo->gso_type & SKB_GSO_TCPV6) + vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; + else if (sinfo->gso_type & SKB_GSO_UDP) + vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; + else if (sinfo->gso_type & SKB_GSO_FCOE) + goto out_free; + else + BUG(); + if (sinfo->gso_type & SKB_GSO_TCP_ECN) + vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; + } else + vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; + vnet_hdr.csum_start = skb->csum_start - + skb_headroom(skb); + vnet_hdr.csum_offset = skb->csum_offset; + } /* else everything is zero */ + + err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr, + vnet_hdr_len); + if (err < 0) + goto out_free; + } + /* * If the address length field is there to be filled in, we fill * it in now. @@ -1502,7 +1642,7 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, * Free or return the buffer as appropriate. Again this * hides all the races and re-entrancy issues from us. */ - err = (flags&MSG_TRUNC) ? skb->len : copied; + err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); out_free: skb_free_datagram(sk, skb); @@ -1740,6 +1880,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv if (optlen < sizeof(req)) return -EINVAL; + if (pkt_sk(sk)->has_vnet_hdr) + return -EINVAL; if (copy_from_user(&req, optval, sizeof(req))) return -EFAULT; return packet_set_ring(sk, &req, 0, optname == PACKET_TX_RING); @@ -1826,6 +1968,22 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv po->origdev = !!val; return 0; } + case PACKET_VNET_HDR: + { + int val; + + if (sock->type != SOCK_RAW) + return -EINVAL; + if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) + return -EBUSY; + if (optlen < sizeof(val)) + return -EINVAL; + if (copy_from_user(&val, optval, sizeof(val))) + return -EFAULT; + + po->has_vnet_hdr = !!val; + return 0; + } default: return -ENOPROTOOPT; } @@ -1874,6 +2032,13 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, len = sizeof(int); val = po->origdev; + data = &val; + break; + case PACKET_VNET_HDR: + if (len > sizeof(int)) + len = sizeof(int); + val = po->has_vnet_hdr; + data = &val; break; #ifdef CONFIG_PACKET_MMAP -- 2.30.2