[deliverable/linux.git] / net / ipv6 / ipcomp6.c

/*
 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
 *
 * Copyright (C)2003 USAGI/WIDE Project
 *
 * Author	Mitsuru KANDA  <mk@linux-ipv6.org>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
/*
 * [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/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>

static void 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_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
		return;

	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;

	pr_debug("pmtu discovery on SA IPCOMP/%08x/%pI6\n",
		 spi, &iph->daddr);
	xfrm_state_put(x);
}

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 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 const struct inet6_protocol ipcomp6_protocol =
{
	.handler	= xfrm6_rcv,
	.err_handler	= ipcomp6_err,
	.flags		= INET6_PROTO_NOPOLICY,
};

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 (inet6_add_protocol(&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 (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
		pr_info("%s: can't remove protocol\n", __func__);
	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
		pr_info("%s: can't remove xfrm type\n", __func__);
}

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
1da177e4 LT	1	/*
	2	* IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
	3	*
	4	* Copyright (C)2003 USAGI/WIDE Project
	5	*
	6	* Author Mitsuru KANDA <mk@linux-ipv6.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
1ab1457c	12	*
1da177e4 LT	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
1ab1457c	17	*
1da177e4 LT	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
1ab1457c	22	/*
1da177e4 LT	23	* [Memo]
	24	*
	25	* Outbound:
1ab1457c YH	26	* The compression of IP datagram MUST be done before AH/ESP processing,
1ab1457c YH	27	* fragmentation, and the addition of Hop-by-Hop/Routing header.
1da177e4 LT	28	*
1da177e4 LT	29	* Inbound:
1ab1457c	30	* The decompression of IP datagram MUST be done after the reassembly,
1da177e4 LT	31	* AH/ESP processing.
1da177e4 LT	32	*/
f3213831 JP	33
	34	#define pr_fmt(fmt) "IPv6: " fmt
	35
1da177e4 LT	36	#include <linux/module.h>
	37	#include <net/ip.h>
	38	#include <net/xfrm.h>
	39	#include <net/ipcomp.h>
1da177e4	40	#include <linux/crypto.h>
4999f362	41	#include <linux/err.h>
1da177e4 LT	42	#include <linux/pfkeyv2.h>
	43	#include <linux/random.h>
	44	#include <linux/percpu.h>
	45	#include <linux/smp.h>
	46	#include <linux/list.h>
	47	#include <linux/vmalloc.h>
	48	#include <linux/rtnetlink.h>
	49	#include <net/icmp.h>
	50	#include <net/ipv6.h>
14c85021	51	#include <net/protocol.h>
1da177e4 LT	52	#include <linux/ipv6.h>
1da177e4 LT	53	#include <linux/icmpv6.h>
4a3e2f71	54	#include <linux/mutex.h>
1da177e4	55
1da177e4	56	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
d5fdd6ba	57	u8 type, u8 code, int offset, __be32 info)
1da177e4	58	{
d74340d3	59	struct net *net = dev_net(skb->dev);
a94cfd19	60	__be32 spi;
b71d1d42	61	const struct ipv6hdr iph = (const struct ipv6hdr )skb->data;
87bdc48d HX	62	struct ip_comp_hdr *ipcomph =
87bdc48d HX	63	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	64	struct xfrm_state *x;
	65
	66	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	67	return;
	68
4195f814	69	spi = htonl(ntohs(ipcomph->cpi));
b71d1d42 ED	70	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
b71d1d42 ED	71	spi, IPPROTO_COMP, AF_INET6);
1da177e4 LT	72	if (!x)
	73	return;
	74
91df42be JP	75	pr_debug("pmtu discovery on SA IPCOMP/%08x/%pI6\n",
91df42be JP	76	spi, &iph->daddr);
1da177e4 LT	77	xfrm_state_put(x);
	78	}
	79
	80	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	81	{
d74340d3	82	struct net *net = xs_net(x);
1da177e4 LT	83	struct xfrm_state *t = NULL;
1da177e4 LT	84
d74340d3	85	t = xfrm_state_alloc(net);
1da177e4 LT	86	if (!t)
	87	goto out;
	88
	89	t->id.proto = IPPROTO_IPV6;
d74340d3	90	t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
6abaaaae HX	91	if (!t->id.spi)
	92	goto error;
	93
1da177e4 LT	94	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	95	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	96	t->props.family = AF_INET6;
e40b3286	97	t->props.mode = x->props.mode;
1da177e4	98	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
bd55775c	99	memcpy(&t->mark, &x->mark, sizeof(t->mark));
1da177e4	100
72cb6962	101	if (xfrm_init_state(t))
1da177e4 LT	102	goto error;
1da177e4 LT	103
1da177e4 LT	104	atomic_set(&t->tunnel_users, 1);
	105
	106	out:
	107	return t;
	108
	109	error:
6abaaaae	110	t->km.state = XFRM_STATE_DEAD;
1da177e4	111	xfrm_state_put(t);
6abaaaae	112	t = NULL;
1da177e4 LT	113	goto out;
	114	}
	115
	116	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	117	{
d74340d3	118	struct net *net = xs_net(x);
1da177e4 LT	119	int err = 0;
1da177e4 LT	120	struct xfrm_state *t = NULL;
a94cfd19	121	__be32 spi;
bd55775c	122	u32 mark = x->mark.m & x->mark.v;
1da177e4	123
d74340d3	124	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
1da177e4	125	if (spi)
bd55775c	126	t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
1da177e4 LT	127	spi, IPPROTO_IPV6, AF_INET6);
	128	if (!t) {
	129	t = ipcomp6_tunnel_create(x);
	130	if (!t) {
	131	err = -EINVAL;
	132	goto out;
	133	}
	134	xfrm_state_insert(t);
	135	xfrm_state_hold(t);
	136	}
	137	x->tunnel = t;
	138	atomic_inc(&t->tunnel_users);
	139
	140	out:
	141	return err;
	142	}
	143
72cb6962	144	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4	145	{
2c3abab7	146	int err = -EINVAL;
1da177e4	147
1da177e4	148	x->props.header_len = 0;
ca68145f	149	switch (x->props.mode) {
ca68145f HX	150	case XFRM_MODE_TRANSPORT:
	151	break;
	152	case XFRM_MODE_TUNNEL:
1da177e4	153	x->props.header_len += sizeof(struct ipv6hdr);
e40b3286	154	break;
ca68145f	155	default:
e40b3286	156	goto out;
ca68145f	157	}
1ab1457c	158
6fccab67 HX	159	err = ipcomp_init_state(x);
6fccab67 HX	160	if (err)
e40b3286 HX	161	goto out;
e40b3286 HX	162
7e49e6de	163	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	164	err = ipcomp6_tunnel_attach(x);
1da177e4 LT	165	if (err)
10e7454e	166	goto out;
1da177e4 LT	167	}
1da177e4 LT	168
1da177e4 LT	169	err = 0;
	170	out:
	171	return err;
1da177e4 LT	172	}
1da177e4 LT	173
533cb5b0	174	static const struct xfrm_type ipcomp6_type =
1da177e4 LT	175	{
	176	.description = "IPCOMP6",
	177	.owner = THIS_MODULE,
	178	.proto = IPPROTO_COMP,
	179	.init_state = ipcomp6_init_state,
6fccab67 HX	180	.destructor = ipcomp_destroy,
	181	.input = ipcomp_input,
	182	.output = ipcomp_output,
aee5adb4	183	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	184	};
1da177e4 LT	185
41135cc8	186	static const struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	187	{
	188	.handler = xfrm6_rcv,
	189	.err_handler = ipcomp6_err,
	190	.flags = INET6_PROTO_NOPOLICY,
	191	};
	192
	193	static int __init ipcomp6_init(void)
	194	{
	195	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
f3213831	196	pr_info("%s: can't add xfrm type\n", __func__);
1da177e4 LT	197	return -EAGAIN;
	198	}
	199	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
f3213831	200	pr_info("%s: can't add protocol\n", __func__);
1da177e4 LT	201	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	202	return -EAGAIN;
	203	}
	204	return 0;
	205	}
	206
	207	static void __exit ipcomp6_fini(void)
	208	{
1ab1457c	209	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
f3213831	210	pr_info("%s: can't remove protocol\n", __func__);
1da177e4	211	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
f3213831	212	pr_info("%s: can't remove xfrm type\n", __func__);
1da177e4 LT	213	}
	214
	215	module_init(ipcomp6_init);
	216	module_exit(ipcomp6_fini);
	217	MODULE_LICENSE("GPL");
	218	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	219	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	220
d3d6dd3a	221	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);