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
tcp6_gro_receive(struct list_head * head,struct sk_buff * skb)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
tcp6_gro_complete(struct sk_buff * skb,int thoff)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
tcp6_gso_segment(struct sk_buff * skb,netdev_features_t features)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
tcpv6_offload_init(void)77 int __init tcpv6_offload_init(void)
78 {
79 return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
80 }
81