[linux-block.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.
 */
#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,
				int type, int code, int offset, __be32 info)
{
	__be32 spi;
	struct ipv6hdr *iph = (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((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	if (!x)
		return;

	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
			spi, NIP6(iph->daddr));
	xfrm_state_put(x);
}

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

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

	t->id.proto = IPPROTO_IPV6;
	t->id.spi = xfrm6_tunnel_alloc_spi((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));

	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)
{
	int err = 0;
	struct xfrm_state *t = NULL;
	__be32 spi;

	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	if (spi)
		t = xfrm_state_lookup((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;
	struct ipcomp_data *ipcd;
	struct xfrm_algo_desc *calg_desc;

	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 error_tunnel;
	}

	err = 0;
out:
	return err;
error_tunnel:
	ipcomp_destroy(x);

	goto out;
}

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 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) {
		printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
		return -EAGAIN;
	}
	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
		printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
		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)
		printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
		printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
}

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	*/
1da177e4 LT	33	#include <linux/module.h>
	34	#include <net/ip.h>
	35	#include <net/xfrm.h>
	36	#include <net/ipcomp.h>
1da177e4	37	#include <linux/crypto.h>
4999f362	38	#include <linux/err.h>
1da177e4 LT	39	#include <linux/pfkeyv2.h>
	40	#include <linux/random.h>
	41	#include <linux/percpu.h>
	42	#include <linux/smp.h>
	43	#include <linux/list.h>
	44	#include <linux/vmalloc.h>
	45	#include <linux/rtnetlink.h>
	46	#include <net/icmp.h>
	47	#include <net/ipv6.h>
14c85021	48	#include <net/protocol.h>
1da177e4 LT	49	#include <linux/ipv6.h>
1da177e4 LT	50	#include <linux/icmpv6.h>
4a3e2f71	51	#include <linux/mutex.h>
1da177e4	52
1da177e4	53	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
1ab1457c	54	int type, int code, int offset, __be32 info)
1da177e4	55	{
a94cfd19	56	__be32 spi;
1da177e4	57	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
87bdc48d HX	58	struct ip_comp_hdr *ipcomph =
87bdc48d HX	59	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	60	struct xfrm_state *x;
	61
	62	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	63	return;
	64
4195f814	65	spi = htonl(ntohs(ipcomph->cpi));
1da177e4 LT	66	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	67	if (!x)
	68	return;
	69
46b86a2d	70	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	71	spi, NIP6(iph->daddr));
	72	xfrm_state_put(x);
	73	}
	74
	75	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	76	{
	77	struct xfrm_state *t = NULL;
	78
	79	t = xfrm_state_alloc();
	80	if (!t)
	81	goto out;
	82
	83	t->id.proto = IPPROTO_IPV6;
	84	t->id.spi = xfrm6_tunnel_alloc_spi((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 LT	92	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	93
72cb6962	94	if (xfrm_init_state(t))
1da177e4 LT	95	goto error;
1da177e4 LT	96
1da177e4 LT	97	atomic_set(&t->tunnel_users, 1);
	98
	99	out:
	100	return t;
	101
	102	error:
6abaaaae	103	t->km.state = XFRM_STATE_DEAD;
1da177e4	104	xfrm_state_put(t);
6abaaaae	105	t = NULL;
1da177e4 LT	106	goto out;
	107	}
	108
	109	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	110	{
	111	int err = 0;
	112	struct xfrm_state *t = NULL;
a94cfd19	113	__be32 spi;
1da177e4 LT	114
	115	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	116	if (spi)
	117	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	118	spi, IPPROTO_IPV6, AF_INET6);
	119	if (!t) {
	120	t = ipcomp6_tunnel_create(x);
	121	if (!t) {
	122	err = -EINVAL;
	123	goto out;
	124	}
	125	xfrm_state_insert(t);
	126	xfrm_state_hold(t);
	127	}
	128	x->tunnel = t;
	129	atomic_inc(&t->tunnel_users);
	130
	131	out:
	132	return err;
	133	}
	134
72cb6962	135	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	136	{
	137	int err;
	138	struct ipcomp_data *ipcd;
	139	struct xfrm_algo_desc *calg_desc;
	140
1da177e4	141	x->props.header_len = 0;
ca68145f	142	switch (x->props.mode) {
ca68145f HX	143	case XFRM_MODE_TRANSPORT:
	144	break;
	145	case XFRM_MODE_TUNNEL:
1da177e4	146	x->props.header_len += sizeof(struct ipv6hdr);
e40b3286	147	break;
ca68145f	148	default:
e40b3286	149	goto out;
ca68145f	150	}
1ab1457c	151
6fccab67 HX	152	err = ipcomp_init_state(x);
6fccab67 HX	153	if (err)
e40b3286 HX	154	goto out;
e40b3286 HX	155
7e49e6de	156	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	157	err = ipcomp6_tunnel_attach(x);
	158	if (err)
	159	goto error_tunnel;
	160	}
	161
1da177e4 LT	162	err = 0;
	163	out:
	164	return err;
	165	error_tunnel:
6fccab67	166	ipcomp_destroy(x);
1da177e4 LT	167
	168	goto out;
	169	}
	170
533cb5b0	171	static const struct xfrm_type ipcomp6_type =
1da177e4 LT	172	{
	173	.description = "IPCOMP6",
	174	.owner = THIS_MODULE,
	175	.proto = IPPROTO_COMP,
	176	.init_state = ipcomp6_init_state,
6fccab67 HX	177	.destructor = ipcomp_destroy,
	178	.input = ipcomp_input,
	179	.output = ipcomp_output,
aee5adb4	180	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	181	};
1da177e4 LT	182
1ab1457c	183	static struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	184	{
	185	.handler = xfrm6_rcv,
	186	.err_handler = ipcomp6_err,
	187	.flags = INET6_PROTO_NOPOLICY,
	188	};
	189
	190	static int __init ipcomp6_init(void)
	191	{
	192	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	193	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	194	return -EAGAIN;
	195	}
	196	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	197	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	198	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	199	return -EAGAIN;
	200	}
	201	return 0;
	202	}
	203
	204	static void __exit ipcomp6_fini(void)
	205	{
1ab1457c	206	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
1da177e4 LT	207	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	208	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	209	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	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);