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 }
79
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