[linux-2.6-block.git] / net / ipv6 / ipcomp6.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
 *
 * Copyright (C)2003 USAGI/WIDE Project
 *
 * Author	Mitsuru KANDA  <mk@linux-ipv6.org>
 */
/*
 * [Memo]
 *
 * Outbound:
 *  The compression of IP datagram MUST be done before AH/ESP processing,
 *  fragmentation, and the addition of Hop-by-Hop/Routing header.
 *
 * Inbound:
 *  The decompression of IP datagram MUST be done after the reassembly,
 *  AH/ESP processing.
 */

#define pr_fmt(fmt) "IPv6: " fmt

#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipcomp.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/pfkeyv2.h>
#include <linux/random.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
#include <net/ip6_route.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>

static int ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
				u8 type, u8 code, int offset, __be32 info)
{
	struct net *net = dev_net(skb->dev);
	__be32 spi;
	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
	struct ip_comp_hdr *ipcomph =
		(struct ip_comp_hdr *)(skb->data + offset);
	struct xfrm_state *x;

	if (type != ICMPV6_PKT_TOOBIG &&
	    type != NDISC_REDIRECT)
		return 0;

	spi = htonl(ntohs(ipcomph->cpi));
	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
			      spi, IPPROTO_COMP, AF_INET6);
	if (!x)
		return 0;

	if (type == NDISC_REDIRECT)
		ip6_redirect(skb, net, skb->dev->ifindex, 0,
			     sock_net_uid(net, NULL));
	else
		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
	xfrm_state_put(x);

	return 0;
}

static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
{
	struct net *net = xs_net(x);
	struct xfrm_state *t = NULL;

	t = xfrm_state_alloc(net);
	if (!t)
		goto out;

	t->id.proto = IPPROTO_IPV6;
	t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
	if (!t->id.spi)
		goto error;

	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	t->props.family = AF_INET6;
	t->props.mode = x->props.mode;
	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
	memcpy(&t->mark, &x->mark, sizeof(t->mark));

	if (xfrm_init_state(t))
		goto error;

	atomic_set(&t->tunnel_users, 1);

out:
	return t;

error:
	t->km.state = XFRM_STATE_DEAD;
	xfrm_state_put(t);
	t = NULL;
	goto out;
}

static int ipcomp6_tunnel_attach(struct xfrm_state *x)
{
	struct net *net = xs_net(x);
	int err = 0;
	struct xfrm_state *t = NULL;
	__be32 spi;
	u32 mark = x->mark.m & x->mark.v;

	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
	if (spi)
		t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
					      spi, IPPROTO_IPV6, AF_INET6);
	if (!t) {
		t = ipcomp6_tunnel_create(x);
		if (!t) {
			err = -EINVAL;
			goto out;
		}
		xfrm_state_insert(t);
		xfrm_state_hold(t);
	}
	x->tunnel = t;
	atomic_inc(&t->tunnel_users);

out:
	return err;
}

static int ipcomp6_init_state(struct xfrm_state *x)
{
	int err = -EINVAL;

	x->props.header_len = 0;
	switch (x->props.mode) {
	case XFRM_MODE_TRANSPORT:
		break;
	case XFRM_MODE_TUNNEL:
		x->props.header_len += sizeof(struct ipv6hdr);
		break;
	default:
		goto out;
	}

	err = ipcomp_init_state(x);
	if (err)
		goto out;

	if (x->props.mode == XFRM_MODE_TUNNEL) {
		err = ipcomp6_tunnel_attach(x);
		if (err)
			goto out;
	}

	err = 0;
out:
	return err;
}

static int ipcomp6_rcv_cb(struct sk_buff *skb, int err)
{
	return 0;
}

static const struct xfrm_type ipcomp6_type = {
	.description	= "IPCOMP6",
	.owner		= THIS_MODULE,
	.proto		= IPPROTO_COMP,
	.init_state	= ipcomp6_init_state,
	.destructor	= ipcomp_destroy,
	.input		= ipcomp_input,
	.output		= ipcomp_output,
	.hdr_offset	= xfrm6_find_1stfragopt,
};

static struct xfrm6_protocol ipcomp6_protocol = {
	.handler	= xfrm6_rcv,
	.cb_handler	= ipcomp6_rcv_cb,
	.err_handler	= ipcomp6_err,
	.priority	= 0,
};

static int __init ipcomp6_init(void)
{
	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
		pr_info("%s: can't add xfrm type\n", __func__);
		return -EAGAIN;
	}
	if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
		pr_info("%s: can't add protocol\n", __func__);
		xfrm_unregister_type(&ipcomp6_type, AF_INET6);
		return -EAGAIN;
	}
	return 0;
}

static void __exit ipcomp6_fini(void)
{
	if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0)
		pr_info("%s: can't remove protocol\n", __func__);
	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
}

module_init(ipcomp6_init);
module_exit(ipcomp6_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");

MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);
Commit	Line	Data
1ccea77e	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
	4	*
	5	* Copyright (C)2003 USAGI/WIDE Project
	6	*
	7	* Author Mitsuru KANDA <mk@linux-ipv6.org>
1da177e4	8	*/
1ab1457c	9	/*
1da177e4 LT	10	* [Memo]
	11	*
	12	* Outbound:
1ab1457c YH	13	* The compression of IP datagram MUST be done before AH/ESP processing,
1ab1457c YH	14	* fragmentation, and the addition of Hop-by-Hop/Routing header.
1da177e4 LT	15	*
1da177e4 LT	16	* Inbound:
1ab1457c	17	* The decompression of IP datagram MUST be done after the reassembly,
1da177e4 LT	18	* AH/ESP processing.
1da177e4 LT	19	*/
f3213831 JP	20
	21	#define pr_fmt(fmt) "IPv6: " fmt
	22
1da177e4 LT	23	#include <linux/module.h>
	24	#include <net/ip.h>
	25	#include <net/xfrm.h>
	26	#include <net/ipcomp.h>
1da177e4	27	#include <linux/crypto.h>
4999f362	28	#include <linux/err.h>
1da177e4 LT	29	#include <linux/pfkeyv2.h>
	30	#include <linux/random.h>
	31	#include <linux/percpu.h>
	32	#include <linux/smp.h>
	33	#include <linux/list.h>
	34	#include <linux/vmalloc.h>
	35	#include <linux/rtnetlink.h>
81aded24	36	#include <net/ip6_route.h>
1da177e4 LT	37	#include <net/icmp.h>
1da177e4 LT	38	#include <net/ipv6.h>
14c85021	39	#include <net/protocol.h>
1da177e4 LT	40	#include <linux/ipv6.h>
1da177e4 LT	41	#include <linux/icmpv6.h>
4a3e2f71	42	#include <linux/mutex.h>
1da177e4	43
59b84351	44	static int ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
d5fdd6ba	45	u8 type, u8 code, int offset, __be32 info)
1da177e4	46	{
d74340d3	47	struct net *net = dev_net(skb->dev);
a94cfd19	48	__be32 spi;
b71d1d42	49	const struct ipv6hdr iph = (const struct ipv6hdr )skb->data;
87bdc48d HX	50	struct ip_comp_hdr *ipcomph =
87bdc48d HX	51	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	52	struct xfrm_state *x;
1da177e4 LT	53
b3b2b9e1	54	if (type != ICMPV6_PKT_TOOBIG &&
ec18d9a2	55	type != NDISC_REDIRECT)
59b84351	56	return 0;
1da177e4	57
4195f814	58	spi = htonl(ntohs(ipcomph->cpi));
b71d1d42 ED	59	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
b71d1d42 ED	60	spi, IPPROTO_COMP, AF_INET6);
1da177e4	61	if (!x)
59b84351	62	return 0;
1da177e4	63
ec18d9a2	64	if (type == NDISC_REDIRECT)
e2d118a1 LC	65	ip6_redirect(skb, net, skb->dev->ifindex, 0,
e2d118a1 LC	66	sock_net_uid(net, NULL));
ec18d9a2	67	else
e2d118a1	68	ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
1da177e4	69	xfrm_state_put(x);
59b84351 SK	70
59b84351 SK	71	return 0;
1da177e4 LT	72	}
	73
	74	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	75	{
d74340d3	76	struct net *net = xs_net(x);
1da177e4 LT	77	struct xfrm_state *t = NULL;
1da177e4 LT	78
d74340d3	79	t = xfrm_state_alloc(net);
1da177e4 LT	80	if (!t)
	81	goto out;
	82
	83	t->id.proto = IPPROTO_IPV6;
d74340d3	84	t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
6abaaaae HX	85	if (!t->id.spi)
	86	goto error;
	87
1da177e4 LT	88	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	89	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	90	t->props.family = AF_INET6;
e40b3286	91	t->props.mode = x->props.mode;
1da177e4	92	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
bd55775c	93	memcpy(&t->mark, &x->mark, sizeof(t->mark));
1da177e4	94
72cb6962	95	if (xfrm_init_state(t))
1da177e4 LT	96	goto error;
1da177e4 LT	97
1da177e4 LT	98	atomic_set(&t->tunnel_users, 1);
	99
	100	out:
	101	return t;
	102
	103	error:
6abaaaae	104	t->km.state = XFRM_STATE_DEAD;
1da177e4	105	xfrm_state_put(t);
6abaaaae	106	t = NULL;
1da177e4 LT	107	goto out;
	108	}
	109
	110	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	111	{
d74340d3	112	struct net *net = xs_net(x);
1da177e4 LT	113	int err = 0;
1da177e4 LT	114	struct xfrm_state *t = NULL;
a94cfd19	115	__be32 spi;
bd55775c	116	u32 mark = x->mark.m & x->mark.v;
1da177e4	117
d74340d3	118	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
1da177e4	119	if (spi)
bd55775c	120	t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
1da177e4 LT	121	spi, IPPROTO_IPV6, AF_INET6);
	122	if (!t) {
	123	t = ipcomp6_tunnel_create(x);
	124	if (!t) {
	125	err = -EINVAL;
	126	goto out;
	127	}
	128	xfrm_state_insert(t);
	129	xfrm_state_hold(t);
	130	}
	131	x->tunnel = t;
	132	atomic_inc(&t->tunnel_users);
	133
	134	out:
	135	return err;
	136	}
	137
72cb6962	138	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4	139	{
2c3abab7	140	int err = -EINVAL;
1da177e4	141
1da177e4	142	x->props.header_len = 0;
ca68145f	143	switch (x->props.mode) {
ca68145f HX	144	case XFRM_MODE_TRANSPORT:
	145	break;
	146	case XFRM_MODE_TUNNEL:
1da177e4	147	x->props.header_len += sizeof(struct ipv6hdr);
e40b3286	148	break;
ca68145f	149	default:
e40b3286	150	goto out;
ca68145f	151	}
1ab1457c	152
6fccab67 HX	153	err = ipcomp_init_state(x);
6fccab67 HX	154	if (err)
e40b3286 HX	155	goto out;
e40b3286 HX	156
7e49e6de	157	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	158	err = ipcomp6_tunnel_attach(x);
1da177e4 LT	159	if (err)
10e7454e	160	goto out;
1da177e4 LT	161	}
1da177e4 LT	162
1da177e4 LT	163	err = 0;
	164	out:
	165	return err;
1da177e4 LT	166	}
1da177e4 LT	167
59b84351 SK	168	static int ipcomp6_rcv_cb(struct sk_buff *skb, int err)
	169	{
	170	return 0;
	171	}
	172
cc24beca	173	static const struct xfrm_type ipcomp6_type = {
1da177e4 LT	174	.description = "IPCOMP6",
	175	.owner = THIS_MODULE,
	176	.proto = IPPROTO_COMP,
	177	.init_state = ipcomp6_init_state,
6fccab67 HX	178	.destructor = ipcomp_destroy,
	179	.input = ipcomp_input,
	180	.output = ipcomp_output,
aee5adb4	181	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	182	};
1da177e4 LT	183
cc24beca	184	static struct xfrm6_protocol ipcomp6_protocol = {
1da177e4	185	.handler = xfrm6_rcv,
59b84351	186	.cb_handler = ipcomp6_rcv_cb,
1da177e4	187	.err_handler = ipcomp6_err,
59b84351	188	.priority = 0,
1da177e4 LT	189	};
	190
	191	static int __init ipcomp6_init(void)
	192	{
	193	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
f3213831	194	pr_info("%s: can't add xfrm type\n", __func__);
1da177e4 LT	195	return -EAGAIN;
1da177e4 LT	196	}
59b84351	197	if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
f3213831	198	pr_info("%s: can't add protocol\n", __func__);
1da177e4 LT	199	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	200	return -EAGAIN;
	201	}
	202	return 0;
	203	}
	204
	205	static void __exit ipcomp6_fini(void)
	206	{
59b84351	207	if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0)
f3213831	208	pr_info("%s: can't remove protocol\n", __func__);
4f518e80	209	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
1da177e4 LT	210	}
	211
	212	module_init(ipcomp6_init);
	213	module_exit(ipcomp6_fini);
	214	MODULE_LICENSE("GPL");
	215	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	216	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	217
d3d6dd3a	218	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);