LXR linux/net/ipv6/tcpv6

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *      IPV6 GSO/GRO offload support
   4 *      Linux INET6 implementation
   5 *
   6 *      TCPv6 GSO/GRO support
   7 */
   8#include <linux/indirect_call_wrapper.h>
   9#include <linux/skbuff.h>
  10#include <net/protocol.h>
  11#include <net/tcp.h>
  12#include <net/ip6_checksum.h>
  13#include "ip6_offload.h"
  14
  15INDIRECT_CALLABLE_SCOPE
  16struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
  17{
  18        /* Don't bother verifying checksum if we're going to flush anyway. */
  19        if (!NAPI_GRO_CB(skb)->flush &&
  20            skb_gro_checksum_validate(skb, IPPROTO_TCP,
  21                                      ip6_gro_compute_pseudo)) {
  22                NAPI_GRO_CB(skb)->flush = 1;
  23                return NULL;
  24        }
  25
  26        return tcp_gro_receive(head, skb);
  27}
  28
  29INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
  30{
  31        const struct ipv6hdr *iph = ipv6_hdr(skb);
  32        struct tcphdr *th = tcp_hdr(skb);
  33
  34        th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
  35                                  &iph->daddr, 0);
  36        skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
  37
  38        return tcp_gro_complete(skb);
  39}
  40
  41static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
  42                                        netdev_features_t features)
  43{
  44        struct tcphdr *th;
  45
  46        if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
  47                return ERR_PTR(-EINVAL);
  48
  49        if (!pskb_may_pull(skb, sizeof(*th)))
  50                return ERR_PTR(-EINVAL);
  51
  52        if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
  53                const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
  54                struct tcphdr *th = tcp_hdr(skb);
  55
  56                /* Set up pseudo header, usually expect stack to have done
  57                 * this.
  58                 */
  59
  60                th->check = 0;
  61                skb->ip_summed = CHECKSUM_PARTIAL;
  62                __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
  63        }
  64
  65        return tcp_gso_segment(skb, features);
  66}
  67static const struct net_offload tcpv6_offload = {
  68        .callbacks = {
  69                .gso_segment    =       tcp6_gso_segment,
  70                .gro_receive    =       tcp6_gro_receive,
  71                .gro_complete   =       tcp6_gro_complete,
  72        },
  73};
  74
  75int __init tcpv6_offload_init(void)
  76{
  77        return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
  78}
  79