aboutsummaryrefslogtreecommitdiff
path: root/net/ipv6/tcpv6_offload.c
blob: 575e2743e331fc0bdd5189c2fe9d10cc1a92f14b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	IPV6 GSO/GRO offload support
 *	Linux INET6 implementation
 *
 *      TCPv6 GSO/GRO support
 */
#include <linux/indirect_call_wrapper.h>
#include <linux/skbuff.h>
#include <net/gro.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <net/ip6_checksum.h>
#include "ip6_offload.h"

INDIRECT_CALLABLE_SCOPE
struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
{
	/* Don't bother verifying checksum if we're going to flush anyway. */
	if (!NAPI_GRO_CB(skb)->flush &&
	    skb_gro_checksum_validate(skb, IPPROTO_TCP,
				      ip6_gro_compute_pseudo)) {
		NAPI_GRO_CB(skb)->flush = 1;
		return NULL;
	}

	return tcp_gro_receive(head, skb);
}

INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
{
	const struct ipv6hdr *iph = ipv6_hdr(skb);
	struct tcphdr *th = tcp_hdr(skb);

	if (unlikely(NAPI_GRO_CB(skb)->is_flist)) {
		skb_shinfo(skb)->gso_type |= SKB_GSO_FRAGLIST | SKB_GSO_TCPV6;
		skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;

		__skb_incr_checksum_unnecessary(skb);

		return 0;
	}

	th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
				  &iph->daddr, 0);
	skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;

	tcp_gro_complete(skb);
	return 0;
}

static void __tcpv6_gso_segment_csum(struct sk_buff *seg,
				     __be16 *oldport, __be16 newport)
{
	struct tcphdr *th;

	if (*oldport == newport)
		return;

	th = tcp_hdr(seg);
	inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false);
	*oldport = newport;
}

static struct sk_buff *__tcpv6_gso_segment_list_csum(struct sk_buff *segs)
{
	const struct tcphdr *th;
	const struct ipv6hdr *iph;
	struct sk_buff *seg;
	struct tcphdr *th2;
	struct ipv6hdr *iph2;

	seg = segs;
	th = tcp_hdr(seg);
	iph = ipv6_hdr(seg);
	th2 = tcp_hdr(seg->next);
	iph2 = ipv6_hdr(seg->next);

	if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) &&
	    ipv6_addr_equal(&iph->saddr, &iph2->saddr) &&
	    ipv6_addr_equal(&iph->daddr, &iph2->daddr))
		return segs;

	while ((seg = seg->next)) {
		th2 = tcp_hdr(seg);
		iph2 = ipv6_hdr(seg);

		iph2->saddr = iph->saddr;
		iph2->daddr = iph->daddr;
		__tcpv6_gso_segment_csum(seg, &th2->source, th->source);
		__tcpv6_gso_segment_csum(seg, &th2->dest, th->dest);
	}

	return segs;
}

static struct sk_buff *__tcp6_gso_segment_list(struct sk_buff *skb,
					      netdev_features_t features)
{
	skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
	if (IS_ERR(skb))
		return skb;

	return __tcpv6_gso_segment_list_csum(skb);
}

static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
					netdev_features_t features)
{
	struct tcphdr *th;

	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
		return ERR_PTR(-EINVAL);

	if (!pskb_may_pull(skb, sizeof(*th)))
		return ERR_PTR(-EINVAL);

	if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)
		return __tcp6_gso_segment_list(skb, features);

	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
		const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
		struct tcphdr *th = tcp_hdr(skb);

		/* Set up pseudo header, usually expect stack to have done
		 * this.
		 */

		th->check = 0;
		skb->ip_summed = CHECKSUM_PARTIAL;
		__tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
	}

	return tcp_gso_segment(skb, features);
}

int __init tcpv6_offload_init(void)
{
	net_hotdata.tcpv6_offload = (struct net_offload) {
		.callbacks = {
			.gso_segment	=	tcp6_gso_segment,
			.gro_receive	=	tcp6_gro_receive,
			.gro_complete	=	tcp6_gro_complete,
		},
	};
	return inet6_add_offload(&net_hotdata.tcpv6_offload, IPPROTO_TCP);
}