From 16cc1400456a4d5d6df9f5e7f1b2c7cb8c50404b Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Wed, 3 Feb 2016 18:02:14 -0500 Subject: [PATCH] packet: move vnet_hdr code to helper functions packet_snd and packet_rcv support virtio net headers for GSO. Move this logic into helper functions to be able to reuse it in tpacket_snd and tpacket_rcv. This is a straighforward code move with one exception. Instead of creating and passing a separate gso_type variable, reuse vnet_hdr.gso_type after conversion from virtio to kernel gso type. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/packet/af_packet.c | 261 +++++++++++++++++++++++------------------ 1 file changed, 148 insertions(+), 113 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 992396aa635c..bd3de7b4fb79 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1960,6 +1960,64 @@ static unsigned int run_filter(struct sk_buff *skb, return res; } +static int __packet_rcv_vnet(const struct sk_buff *skb, + struct virtio_net_hdr *vnet_hdr) +{ + *vnet_hdr = (const struct virtio_net_hdr) { 0 }; + + 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 = + __cpu_to_virtio16(vio_le(), skb_headlen(skb)); + vnet_hdr->gso_size = + __cpu_to_virtio16(vio_le(), 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) + return -EINVAL; + 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 = __cpu_to_virtio16(vio_le(), + skb_checksum_start_offset(skb)); + vnet_hdr->csum_offset = __cpu_to_virtio16(vio_le(), + skb->csum_offset); + } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { + vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID; + } /* else everything is zero */ + + return 0; +} + +static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, + size_t *len) +{ + struct virtio_net_hdr vnet_hdr; + + if (*len < sizeof(vnet_hdr)) + return -EINVAL; + *len -= sizeof(vnet_hdr); + + if (__packet_rcv_vnet(skb, &vnet_hdr)) + return -EINVAL; + + return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr)); +} + /* * This function makes lazy skb cloning in hope that most of packets * are discarded by BPF. @@ -2347,6 +2405,84 @@ static void tpacket_set_protocol(const struct net_device *dev, } } +static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) +{ + unsigned short gso_type = 0; + + if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + + __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > + __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) + vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), + __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + + __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); + + if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) + return -EINVAL; + + 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: + return -EINVAL; + } + + if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) + gso_type |= SKB_GSO_TCP_ECN; + + if (vnet_hdr->gso_size == 0) + return -EINVAL; + } + + vnet_hdr->gso_type = gso_type; /* changes type, temporary storage */ + return 0; +} + +static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, + struct virtio_net_hdr *vnet_hdr) +{ + int n; + + if (*len < sizeof(*vnet_hdr)) + return -EINVAL; + *len -= sizeof(*vnet_hdr); + + n = copy_from_iter(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter); + if (n != sizeof(*vnet_hdr)) + return -EFAULT; + + return __packet_snd_vnet_parse(vnet_hdr, *len); +} + +static int packet_snd_vnet_gso(struct sk_buff *skb, + struct virtio_net_hdr *vnet_hdr) +{ + if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start); + u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset); + + if (!skb_partial_csum_set(skb, s, o)) + return -EINVAL; + } + + skb_shinfo(skb)->gso_size = + __virtio16_to_cpu(vio_le(), vnet_hdr->gso_size); + skb_shinfo(skb)->gso_type = vnet_hdr->gso_type; + + /* Header must be checked, and gso_segs computed. */ + skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; + skb_shinfo(skb)->gso_segs = 0; + return 0; +} + static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, void *frame, struct net_device *dev, int size_max, __be16 proto, unsigned char *addr, int hlen) @@ -2643,12 +2779,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) struct sockcm_cookie sockc; 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; int hlen, tlen; int extra_len = 0; - ssize_t n; /* * Get and verify the address. @@ -2686,53 +2819,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) if (sock->type == SOCK_RAW) reserve = dev->hard_header_len; 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 = -EFAULT; - n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter); - if (n != vnet_hdr_len) - goto out_unlock; - - if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && - (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + - __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 > - __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len))) - vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(), - __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) + - __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2); - - err = -EINVAL; - if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len) + err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); + if (err) 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; - - } } if (unlikely(sock_flag(sk, SOCK_NOFCS))) { @@ -2744,7 +2833,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) } err = -EMSGSIZE; - if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) + if (!vnet_hdr.gso_type && + (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) goto out_unlock; err = -ENOBUFS; @@ -2775,7 +2865,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); - if (!gso_type && (len > dev->mtu + reserve + extra_len) && + if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && !packet_extra_vlan_len_allowed(dev, skb)) { err = -EMSGSIZE; goto out_free; @@ -2789,24 +2879,10 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) packet_pick_tx_queue(dev, skb); if (po->has_vnet_hdr) { - if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { - u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start); - u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset); - if (!skb_partial_csum_set(skb, s, o)) { - err = -EINVAL; - goto out_free; - } - } - - skb_shinfo(skb)->gso_size = - __virtio16_to_cpu(vio_le(), 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; + err = packet_snd_vnet_gso(skb, &vnet_hdr); + if (err) + goto out_free; + len += sizeof(vnet_hdr); } skb_probe_transport_header(skb, reserve); @@ -3177,51 +3253,10 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, packet_rcv_has_room(pkt_sk(sk), NULL); 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) - goto out_free; - - len -= vnet_hdr_len; - - 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 = - __cpu_to_virtio16(vio_le(), skb_headlen(skb)); - vnet_hdr.gso_size = - __cpu_to_virtio16(vio_le(), 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 = __cpu_to_virtio16(vio_le(), - skb_checksum_start_offset(skb)); - vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(), - skb->csum_offset); - } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { - vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID; - } /* else everything is zero */ - - err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len); - if (err < 0) + err = packet_rcv_vnet(msg, skb, &len); + if (err) goto out_free; + vnet_hdr_len = sizeof(struct virtio_net_hdr); } /* You lose any data beyond the buffer you gave. If it worries -- 2.20.1