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/gro.h>
  11 #include <net/protocol.h>
  12 #include <net/tcp.h>
  13 #include <net/ip6_checksum.h>
  14 #include "ip6_offload.h"
  15
  16 INDIRECT_CALLABLE_SCOPE
  17 struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
  18 {
  19         /* Don't bother verifying checksum if we're going to flush anyway. */
  20         if (!NAPI_GRO_CB(skb)->flush &&
  21             skb_gro_checksum_validate(skb, IPPROTO_TCP,
  22                                       ip6_gro_compute_pseudo)) {
  23                 NAPI_GRO_CB(skb)->flush = 1;
  24                 return NULL;
  25         }
  26
  27         return tcp_gro_receive(head, skb);
  28 }
  29
  30 INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
  31 {
  32         const struct ipv6hdr *iph = ipv6_hdr(skb);
  33         struct tcphdr *th = tcp_hdr(skb);
  34
  35         th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
  36                                   &iph->daddr, 0);
  37         skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
  38
  39         tcp_gro_complete(skb);
  40         return 0;
  41 }
  42
  43 static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
  44                                         netdev_features_t features)
  45 {
  46         struct tcphdr *th;
  47
  48         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
  49                 return ERR_PTR(-EINVAL);
  50
  51         if (!pskb_may_pull(skb, sizeof(*th)))
  52                 return ERR_PTR(-EINVAL);
  53
  54         if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
  55                 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
  56                 struct tcphdr *th = tcp_hdr(skb);
  57
  58                 /* Set up pseudo header, usually expect stack to have done
  59                  * this.
  60                  */
  61
  62                 th->check = 0;
  63                 skb->ip_summed = CHECKSUM_PARTIAL;
  64                 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
  65         }
  66
  67         return tcp_gso_segment(skb, features);
  68 }
  69 static const struct net_offload tcpv6_offload = {
  70         .callbacks = {
  71                 .gso_segment    =       tcp6_gso_segment,
  72                 .gro_receive    =       tcp6_gro_receive,
  73                 .gro_complete   =       tcp6_gro_complete,
  74         },
  75 };
  76
  77 int __init tcpv6_offload_init(void)
  78 {
  79         return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
  80 }