aboutsummaryrefslogtreecommitdiffstats
path: root/net/sctp/offload.c
blob: edfcf16e704c4e02a93a13e2bdd507e91658ba0f (plain) (blame)
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
/*
 * sctp_offload - GRO/GSO Offloading for SCTP
 *
 * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/socket.h>
#include <linux/sctp.h>
#include <linux/proc_fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/kfifo.h>
#include <linux/time.h>
#include <net/net_namespace.h>

#include <linux/skbuff.h>
#include <net/sctp/sctp.h>
#include <net/sctp/checksum.h>
#include <net/protocol.h>

static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
{
	skb->ip_summed = CHECKSUM_NONE;
	skb->csum_not_inet = 0;
	gso_reset_checksum(skb, ~0);
	return sctp_compute_cksum(skb, skb_transport_offset(skb));
}

static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
					netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct sctphdr *sh;

	if (!skb_is_gso_sctp(skb))
		goto out;

	sh = sctp_hdr(skb);
	if (!pskb_may_pull(skb, sizeof(*sh)))
		goto out;

	__skb_pull(skb, sizeof(*sh));

	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
		/* Packet is from an untrusted source, reset gso_segs. */
		struct skb_shared_info *pinfo = skb_shinfo(skb);
		struct sk_buff *frag_iter;

		pinfo->gso_segs = 0;
		if (skb->len != skb->data_len) {
			/* Means we have chunks in here too */
			pinfo->gso_segs++;
		}

		skb_walk_frags(skb, frag_iter)
			pinfo->gso_segs++;

		segs = NULL;
		goto out;
	}

	segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG);
	if (IS_ERR(segs))
		goto out;

	/* All that is left is update SCTP CRC if necessary */
	if (!(features & NETIF_F_SCTP_CRC)) {
		for (skb = segs; skb; skb = skb->next) {
			if (skb->ip_summed == CHECKSUM_PARTIAL) {
				sh = sctp_hdr(skb);
				sh->checksum = sctp_gso_make_checksum(skb);
			}
		}
	}

out:
	return segs;
}

static const struct net_offload sctp_offload = {
	.callbacks = {
		.gso_segment = sctp_gso_segment,
	},
};

static const struct net_offload sctp6_offload = {
	.callbacks = {
		.gso_segment = sctp_gso_segment,
	},
};

static const struct skb_checksum_ops crc32c_csum_ops = {
	.update  = sctp_csum_update,
	.combine = sctp_csum_combine,
};

int __init sctp_offload_init(void)
{
	int ret;

	ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
	if (ret)
		goto out;

	ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
	if (ret)
		goto ipv4;

	crc32c_csum_stub = &crc32c_csum_ops;
	return ret;

ipv4:
	inet_del_offload(&sctp_offload, IPPROTO_SCTP);
out:
	return ret;
}