net/ipv6/tcpv6_offload.c

   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
  15 INDIRECT_CALLABLE_SCOPE
  16 struct 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
  29 INDIRECT_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
  41 static 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 }
  67 static 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
  75 int __init tcpv6_offload_init(void)
  76 {
  77         return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
  78 }