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
16INDIRECT_CALLABLE_SCOPE
17struct 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
30INDIRECT_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(len: skb->len - thoff, saddr: &iph->saddr,
36 daddr: &iph->daddr, base: 0);
37 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
38
39 tcp_gro_complete(skb);
40 return 0;
41}
42
43static 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(error: -EINVAL);
50
51 if (!pskb_may_pull(skb, len: sizeof(*th)))
52 return ERR_PTR(error: -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, saddr: &ipv6h->saddr, daddr: &ipv6h->daddr);
65 }
66
67 return tcp_gso_segment(skb, features);
68}
69static 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
77int __init tcpv6_offload_init(void)
78{
79 return inet6_add_offload(prot: &tcpv6_offload, IPPROTO_TCP);
80}
81

source code of linux/net/ipv6/tcpv6_offload.c