[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, see <http://www.gnu.org/licenses/>.
 */
/*
 * [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__);
	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	18	* You should have received a copy of the GNU General Public License
a99421d9	19	* along with this program; if not, see <http://www.gnu.org/licenses/>.
1da177e4	20	*/
1ab1457c	21	/*
1da177e4 LT	22	* [Memo]
	23	*
	24	* Outbound:
1ab1457c YH	25	* The compression of IP datagram MUST be done before AH/ESP processing,
1ab1457c YH	26	* fragmentation, and the addition of Hop-by-Hop/Routing header.
1da177e4 LT	27	*
1da177e4 LT	28	* Inbound:
1ab1457c	29	* The decompression of IP datagram MUST be done after the reassembly,
1da177e4 LT	30	* AH/ESP processing.
1da177e4 LT	31	*/
f3213831 JP	32
	33	#define pr_fmt(fmt) "IPv6: " fmt
	34
1da177e4 LT	35	#include <linux/module.h>
	36	#include <net/ip.h>
	37	#include <net/xfrm.h>
	38	#include <net/ipcomp.h>
1da177e4	39	#include <linux/crypto.h>
4999f362	40	#include <linux/err.h>
1da177e4 LT	41	#include <linux/pfkeyv2.h>
	42	#include <linux/random.h>
	43	#include <linux/percpu.h>
	44	#include <linux/smp.h>
	45	#include <linux/list.h>
	46	#include <linux/vmalloc.h>
	47	#include <linux/rtnetlink.h>
81aded24	48	#include <net/ip6_route.h>
1da177e4 LT	49	#include <net/icmp.h>
1da177e4 LT	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
59b84351	56	static int 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;
1da177e4 LT	65
b3b2b9e1	66	if (type != ICMPV6_PKT_TOOBIG &&
ec18d9a2	67	type != NDISC_REDIRECT)
59b84351	68	return 0;
1da177e4	69
4195f814	70	spi = htonl(ntohs(ipcomph->cpi));
b71d1d42 ED	71	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
b71d1d42 ED	72	spi, IPPROTO_COMP, AF_INET6);
1da177e4	73	if (!x)
59b84351	74	return 0;
1da177e4	75
ec18d9a2	76	if (type == NDISC_REDIRECT)
e2d118a1 LC	77	ip6_redirect(skb, net, skb->dev->ifindex, 0,
e2d118a1 LC	78	sock_net_uid(net, NULL));
ec18d9a2	79	else
e2d118a1	80	ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
1da177e4	81	xfrm_state_put(x);
59b84351 SK	82
59b84351 SK	83	return 0;
1da177e4 LT	84	}
	85
	86	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	87	{
d74340d3	88	struct net *net = xs_net(x);
1da177e4 LT	89	struct xfrm_state *t = NULL;
1da177e4 LT	90
d74340d3	91	t = xfrm_state_alloc(net);
1da177e4 LT	92	if (!t)
	93	goto out;
	94
	95	t->id.proto = IPPROTO_IPV6;
d74340d3	96	t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
6abaaaae HX	97	if (!t->id.spi)
	98	goto error;
	99
1da177e4 LT	100	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	101	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	102	t->props.family = AF_INET6;
e40b3286	103	t->props.mode = x->props.mode;
1da177e4	104	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
bd55775c	105	memcpy(&t->mark, &x->mark, sizeof(t->mark));
1da177e4	106
72cb6962	107	if (xfrm_init_state(t))
1da177e4 LT	108	goto error;
1da177e4 LT	109
1da177e4 LT	110	atomic_set(&t->tunnel_users, 1);
	111
	112	out:
	113	return t;
	114
	115	error:
6abaaaae	116	t->km.state = XFRM_STATE_DEAD;
1da177e4	117	xfrm_state_put(t);
6abaaaae	118	t = NULL;
1da177e4 LT	119	goto out;
	120	}
	121
	122	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	123	{
d74340d3	124	struct net *net = xs_net(x);
1da177e4 LT	125	int err = 0;
1da177e4 LT	126	struct xfrm_state *t = NULL;
a94cfd19	127	__be32 spi;
bd55775c	128	u32 mark = x->mark.m & x->mark.v;
1da177e4	129
d74340d3	130	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
1da177e4	131	if (spi)
bd55775c	132	t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
1da177e4 LT	133	spi, IPPROTO_IPV6, AF_INET6);
	134	if (!t) {
	135	t = ipcomp6_tunnel_create(x);
	136	if (!t) {
	137	err = -EINVAL;
	138	goto out;
	139	}
	140	xfrm_state_insert(t);
	141	xfrm_state_hold(t);
	142	}
	143	x->tunnel = t;
	144	atomic_inc(&t->tunnel_users);
	145
	146	out:
	147	return err;
	148	}
	149
72cb6962	150	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4	151	{
2c3abab7	152	int err = -EINVAL;
1da177e4	153
1da177e4	154	x->props.header_len = 0;
ca68145f	155	switch (x->props.mode) {
ca68145f HX	156	case XFRM_MODE_TRANSPORT:
	157	break;
	158	case XFRM_MODE_TUNNEL:
1da177e4	159	x->props.header_len += sizeof(struct ipv6hdr);
e40b3286	160	break;
ca68145f	161	default:
e40b3286	162	goto out;
ca68145f	163	}
1ab1457c	164
6fccab67 HX	165	err = ipcomp_init_state(x);
6fccab67 HX	166	if (err)
e40b3286 HX	167	goto out;
e40b3286 HX	168
7e49e6de	169	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	170	err = ipcomp6_tunnel_attach(x);
1da177e4 LT	171	if (err)
10e7454e	172	goto out;
1da177e4 LT	173	}
1da177e4 LT	174
1da177e4 LT	175	err = 0;
	176	out:
	177	return err;
1da177e4 LT	178	}
1da177e4 LT	179
59b84351 SK	180	static int ipcomp6_rcv_cb(struct sk_buff *skb, int err)
	181	{
	182	return 0;
	183	}
	184
cc24beca	185	static const struct xfrm_type ipcomp6_type = {
1da177e4 LT	186	.description = "IPCOMP6",
	187	.owner = THIS_MODULE,
	188	.proto = IPPROTO_COMP,
	189	.init_state = ipcomp6_init_state,
6fccab67 HX	190	.destructor = ipcomp_destroy,
	191	.input = ipcomp_input,
	192	.output = ipcomp_output,
aee5adb4	193	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	194	};
1da177e4 LT	195
cc24beca	196	static struct xfrm6_protocol ipcomp6_protocol = {
1da177e4	197	.handler = xfrm6_rcv,
59b84351	198	.cb_handler = ipcomp6_rcv_cb,
1da177e4	199	.err_handler = ipcomp6_err,
59b84351	200	.priority = 0,
1da177e4 LT	201	};
	202
	203	static int __init ipcomp6_init(void)
	204	{
	205	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
f3213831	206	pr_info("%s: can't add xfrm type\n", __func__);
1da177e4 LT	207	return -EAGAIN;
1da177e4 LT	208	}
59b84351	209	if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
f3213831	210	pr_info("%s: can't add protocol\n", __func__);
1da177e4 LT	211	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	212	return -EAGAIN;
	213	}
	214	return 0;
	215	}
	216
	217	static void __exit ipcomp6_fini(void)
	218	{
59b84351	219	if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0)
f3213831	220	pr_info("%s: can't remove protocol\n", __func__);
1da177e4	221	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
f3213831	222	pr_info("%s: can't remove xfrm type\n", __func__);
1da177e4 LT	223	}
	224
	225	module_init(ipcomp6_init);
	226	module_exit(ipcomp6_fini);
	227	MODULE_LICENSE("GPL");
	228	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	229	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	230
d3d6dd3a	231	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);