[mirror_ubuntu-bionic-kernel.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,
				u8 type, u8 code, int offset, __be32 info)
{
	struct net *net = dev_net(skb->dev);
	__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(net, (xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	if (!x)
		return;

	printk(KERN_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));

	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;

	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
	if (spi)
		t = xfrm_state_lookup(net, (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) {
		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,
d5fdd6ba	54	u8 type, u8 code, int offset, __be32 info)
1da177e4	55	{
d74340d3	56	struct net *net = dev_net(skb->dev);
a94cfd19	57	__be32 spi;
1da177e4	58	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
87bdc48d HX	59	struct ip_comp_hdr *ipcomph =
87bdc48d HX	60	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	61	struct xfrm_state *x;
	62
	63	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	64	return;
	65
4195f814	66	spi = htonl(ntohs(ipcomph->cpi));
d74340d3	67	x = xfrm_state_lookup(net, (xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
1da177e4 LT	68	if (!x)
	69	return;
	70
5b095d98	71	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI6\n",
0c6ce78a	72	spi, &iph->daddr);
1da177e4 LT	73	xfrm_state_put(x);
	74	}
	75
	76	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	77	{
d74340d3	78	struct net *net = xs_net(x);
1da177e4 LT	79	struct xfrm_state *t = NULL;
1da177e4 LT	80
d74340d3	81	t = xfrm_state_alloc(net);
1da177e4 LT	82	if (!t)
	83	goto out;
	84
	85	t->id.proto = IPPROTO_IPV6;
d74340d3	86	t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
6abaaaae HX	87	if (!t->id.spi)
	88	goto error;
	89
1da177e4 LT	90	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	91	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	92	t->props.family = AF_INET6;
e40b3286	93	t->props.mode = x->props.mode;
1da177e4 LT	94	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	95
72cb6962	96	if (xfrm_init_state(t))
1da177e4 LT	97	goto error;
1da177e4 LT	98
1da177e4 LT	99	atomic_set(&t->tunnel_users, 1);
	100
	101	out:
	102	return t;
	103
	104	error:
6abaaaae	105	t->km.state = XFRM_STATE_DEAD;
1da177e4	106	xfrm_state_put(t);
6abaaaae	107	t = NULL;
1da177e4 LT	108	goto out;
	109	}
	110
	111	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	112	{
d74340d3	113	struct net *net = xs_net(x);
1da177e4 LT	114	int err = 0;
1da177e4 LT	115	struct xfrm_state *t = NULL;
a94cfd19	116	__be32 spi;
1da177e4	117
d74340d3	118	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
1da177e4	119	if (spi)
d74340d3	120	t = xfrm_state_lookup(net, (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
533cb5b0	168	static const struct xfrm_type ipcomp6_type =
1da177e4 LT	169	{
	170	.description = "IPCOMP6",
	171	.owner = THIS_MODULE,
	172	.proto = IPPROTO_COMP,
	173	.init_state = ipcomp6_init_state,
6fccab67 HX	174	.destructor = ipcomp_destroy,
	175	.input = ipcomp_input,
	176	.output = ipcomp_output,
aee5adb4	177	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	178	};
1da177e4 LT	179
41135cc8	180	static const struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	181	{
	182	.handler = xfrm6_rcv,
	183	.err_handler = ipcomp6_err,
	184	.flags = INET6_PROTO_NOPOLICY,
	185	};
	186
	187	static int __init ipcomp6_init(void)
	188	{
	189	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	190	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	191	return -EAGAIN;
	192	}
	193	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	194	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	195	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	196	return -EAGAIN;
	197	}
	198	return 0;
	199	}
	200
	201	static void __exit ipcomp6_fini(void)
	202	{
1ab1457c	203	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
1da177e4 LT	204	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	205	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	206	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	207	}
	208
	209	module_init(ipcomp6_init);
	210	module_exit(ipcomp6_fini);
	211	MODULE_LICENSE("GPL");
	212	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	213	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	214
d3d6dd3a	215	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);