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(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
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(-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
70int __init tcpv6_offload_init(void)
71{
72	net_hotdata.tcpv6_offload = (struct net_offload) {
73		.callbacks = {
74			.gso_segment	=	tcp6_gso_segment,
75			.gro_receive	=	tcp6_gro_receive,
76			.gro_complete	=	tcp6_gro_complete,
77		},
78	};
79	return inet6_add_offload(&net_hotdata.tcpv6_offload, IPPROTO_TCP);
80}
81