[mirror_ubuntu-bionic-kernel.git] / net / ipv6 / tunnel6.c

/*
 * Copyright (C)2003,2004 USAGI/WIDE Project
 *
 * 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/>.
 *
 * Authors	Mitsuru KANDA  <mk@linux-ipv6.org>
 *		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
 */

#define pr_fmt(fmt) "IPv6: " fmt

#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/xfrm.h>

static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
static DEFINE_MUTEX(tunnel6_mutex);

int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
{
	struct xfrm6_tunnel __rcu **pprev;
	struct xfrm6_tunnel *t;
	int ret = -EEXIST;
	int priority = handler->priority;

	mutex_lock(&tunnel6_mutex);

	for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
	     (t = rcu_dereference_protected(*pprev,
			lockdep_is_held(&tunnel6_mutex))) != NULL;
	     pprev = &t->next) {
		if (t->priority > priority)
			break;
		if (t->priority == priority)
			goto err;
	}

	handler->next = *pprev;
	rcu_assign_pointer(*pprev, handler);

	ret = 0;

err:
	mutex_unlock(&tunnel6_mutex);

	return ret;
}
EXPORT_SYMBOL(xfrm6_tunnel_register);

int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
{
	struct xfrm6_tunnel __rcu **pprev;
	struct xfrm6_tunnel *t;
	int ret = -ENOENT;

	mutex_lock(&tunnel6_mutex);

	for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
	     (t = rcu_dereference_protected(*pprev,
			lockdep_is_held(&tunnel6_mutex))) != NULL;
	     pprev = &t->next) {
		if (t == handler) {
			*pprev = handler->next;
			ret = 0;
			break;
		}
	}

	mutex_unlock(&tunnel6_mutex);

	synchronize_net();

	return ret;
}
EXPORT_SYMBOL(xfrm6_tunnel_deregister);

#define for_each_tunnel_rcu(head, handler)		\
	for (handler = rcu_dereference(head);		\
	     handler != NULL;				\
	     handler = rcu_dereference(handler->next))	\

static int tunnel6_rcv(struct sk_buff *skb)
{
	struct xfrm6_tunnel *handler;

	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
		goto drop;

	for_each_tunnel_rcu(tunnel6_handlers, handler)
		if (!handler->handler(skb))
			return 0;

	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);

drop:
	kfree_skb(skb);
	return 0;
}

static int tunnel46_rcv(struct sk_buff *skb)
{
	struct xfrm6_tunnel *handler;

	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
		goto drop;

	for_each_tunnel_rcu(tunnel46_handlers, handler)
		if (!handler->handler(skb))
			return 0;

	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);

drop:
	kfree_skb(skb);
	return 0;
}

static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			u8 type, u8 code, int offset, __be32 info)
{
	struct xfrm6_tunnel *handler;

	for_each_tunnel_rcu(tunnel6_handlers, handler)
		if (!handler->err_handler(skb, opt, type, code, offset, info))
			break;
}

static void tunnel46_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			 u8 type, u8 code, int offset, __be32 info)
{
	struct xfrm6_tunnel *handler;

	for_each_tunnel_rcu(tunnel46_handlers, handler)
		if (!handler->err_handler(skb, opt, type, code, offset, info))
			break;
}

static const struct inet6_protocol tunnel6_protocol = {
	.handler	= tunnel6_rcv,
	.err_handler	= tunnel6_err,
	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};

static const struct inet6_protocol tunnel46_protocol = {
	.handler	= tunnel46_rcv,
	.err_handler	= tunnel46_err,
	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};

static int __init tunnel6_init(void)
{
	if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
		pr_err("%s: can't add protocol\n", __func__);
		return -EAGAIN;
	}
	if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
		pr_err("%s: can't add protocol\n", __func__);
		inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
		return -EAGAIN;
	}
	return 0;
}

static void __exit tunnel6_fini(void)
{
	if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
		pr_err("%s: can't remove protocol\n", __func__);
	if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
		pr_err("%s: can't remove protocol\n", __func__);
}

module_init(tunnel6_init);
module_exit(tunnel6_fini);
MODULE_LICENSE("GPL");
Commit	Line	Data
d2acc347 HX	1	/*
	2	* Copyright (C)2003,2004 USAGI/WIDE Project
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
a99421d9	15	* along with this program; if not, see <http://www.gnu.org/licenses/>.
d2acc347 HX	16	*
d2acc347 HX	17	* Authors Mitsuru KANDA <mk@linux-ipv6.org>
67ba4152	18	* YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
d2acc347 HX	19	*/
d2acc347 HX	20
f3213831 JP	21	#define pr_fmt(fmt) "IPv6: " fmt
f3213831 JP	22
50fba2aa	23	#include <linux/icmpv6.h>
d2acc347 HX	24	#include <linux/init.h>
	25	#include <linux/module.h>
	26	#include <linux/mutex.h>
	27	#include <linux/netdevice.h>
	28	#include <linux/skbuff.h>
5a0e3ad6	29	#include <linux/slab.h>
50fba2aa	30	#include <net/ipv6.h>
d2acc347 HX	31	#include <net/protocol.h>
	32	#include <net/xfrm.h>
	33
6f0bcf15 ED	34	static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
6f0bcf15 ED	35	static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
d2acc347 HX	36	static DEFINE_MUTEX(tunnel6_mutex);
d2acc347 HX	37
73d605d1	38	int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
d2acc347	39	{
6f0bcf15 ED	40	struct xfrm6_tunnel __rcu **pprev;
6f0bcf15 ED	41	struct xfrm6_tunnel *t;
d2acc347 HX	42	int ret = -EEXIST;
	43	int priority = handler->priority;
	44
	45	mutex_lock(&tunnel6_mutex);
	46
73d605d1	47	for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
6f0bcf15 ED	48	(t = rcu_dereference_protected(*pprev,
	49	lockdep_is_held(&tunnel6_mutex))) != NULL;
	50	pprev = &t->next) {
	51	if (t->priority > priority)
d2acc347	52	break;
6f0bcf15	53	if (t->priority == priority)
d2acc347 HX	54	goto err;
	55	}
	56
	57	handler->next = *pprev;
49d61e23	58	rcu_assign_pointer(*pprev, handler);
d2acc347 HX	59
	60	ret = 0;
	61
	62	err:
	63	mutex_unlock(&tunnel6_mutex);
	64
	65	return ret;
	66	}
d2acc347 HX	67	EXPORT_SYMBOL(xfrm6_tunnel_register);
d2acc347 HX	68
73d605d1	69	int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
d2acc347	70	{
6f0bcf15 ED	71	struct xfrm6_tunnel __rcu **pprev;
6f0bcf15 ED	72	struct xfrm6_tunnel *t;
d2acc347 HX	73	int ret = -ENOENT;
	74
	75	mutex_lock(&tunnel6_mutex);
	76
73d605d1	77	for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
6f0bcf15 ED	78	(t = rcu_dereference_protected(*pprev,
	79	lockdep_is_held(&tunnel6_mutex))) != NULL;
	80	pprev = &t->next) {
	81	if (t == handler) {
d2acc347 HX	82	*pprev = handler->next;
	83	ret = 0;
	84	break;
	85	}
	86	}
	87
	88	mutex_unlock(&tunnel6_mutex);
	89
	90	synchronize_net();
	91
	92	return ret;
	93	}
d2acc347 HX	94	EXPORT_SYMBOL(xfrm6_tunnel_deregister);
d2acc347 HX	95
875168a9 ED	96	#define for_each_tunnel_rcu(head, handler) \
	97	for (handler = rcu_dereference(head); \
	98	handler != NULL; \
	99	handler = rcu_dereference(handler->next)) \
	100
e5bbef20	101	static int tunnel6_rcv(struct sk_buff *skb)
d2acc347	102	{
d2acc347 HX	103	struct xfrm6_tunnel *handler;
d2acc347 HX	104
50fba2aa HX	105	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	106	goto drop;
	107
875168a9	108	for_each_tunnel_rcu(tunnel6_handlers, handler)
d2acc347 HX	109	if (!handler->handler(skb))
	110	return 0;
	111
3ffe533c	112	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
50fba2aa HX	113
50fba2aa HX	114	drop:
d2acc347 HX	115	kfree_skb(skb);
	116	return 0;
	117	}
	118
e5bbef20	119	static int tunnel46_rcv(struct sk_buff *skb)
73d605d1	120	{
73d605d1 KM	121	struct xfrm6_tunnel *handler;
73d605d1 KM	122
82836372	123	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
73d605d1 KM	124	goto drop;
73d605d1 KM	125
875168a9	126	for_each_tunnel_rcu(tunnel46_handlers, handler)
73d605d1 KM	127	if (!handler->handler(skb))
	128	return 0;
	129
3ffe533c	130	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
73d605d1 KM	131
	132	drop:
	133	kfree_skb(skb);
	134	return 0;
	135	}
	136
d2acc347	137	static void tunnel6_err(struct sk_buff skb, struct inet6_skb_parm opt,
d5fdd6ba	138	u8 type, u8 code, int offset, __be32 info)
d2acc347 HX	139	{
	140	struct xfrm6_tunnel *handler;
	141
875168a9	142	for_each_tunnel_rcu(tunnel6_handlers, handler)
d2acc347 HX	143	if (!handler->err_handler(skb, opt, type, code, offset, info))
	144	break;
	145	}
	146
ebac62fe MK	147	static void tunnel46_err(struct sk_buff skb, struct inet6_skb_parm opt,
	148	u8 type, u8 code, int offset, __be32 info)
	149	{
	150	struct xfrm6_tunnel *handler;
	151
	152	for_each_tunnel_rcu(tunnel46_handlers, handler)
	153	if (!handler->err_handler(skb, opt, type, code, offset, info))
	154	break;
	155	}
	156
41135cc8	157	static const struct inet6_protocol tunnel6_protocol = {
d2acc347 HX	158	.handler = tunnel6_rcv,
	159	.err_handler = tunnel6_err,
	160	.flags = INET6_PROTO_NOPOLICY\|INET6_PROTO_FINAL,
	161	};
	162
41135cc8	163	static const struct inet6_protocol tunnel46_protocol = {
73d605d1	164	.handler = tunnel46_rcv,
ebac62fe	165	.err_handler = tunnel46_err,
73d605d1 KM	166	.flags = INET6_PROTO_NOPOLICY\|INET6_PROTO_FINAL,
	167	};
	168
d2acc347 HX	169	static int __init tunnel6_init(void)
	170	{
	171	if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
f3213831	172	pr_err("%s: can't add protocol\n", __func__);
d2acc347 HX	173	return -EAGAIN;
d2acc347 HX	174	}
73d605d1	175	if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
f3213831	176	pr_err("%s: can't add protocol\n", __func__);
73d605d1 KM	177	inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
	178	return -EAGAIN;
	179	}
d2acc347 HX	180	return 0;
	181	}
	182
	183	static void __exit tunnel6_fini(void)
	184	{
73d605d1	185	if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
f3213831	186	pr_err("%s: can't remove protocol\n", __func__);
d2acc347	187	if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
f3213831	188	pr_err("%s: can't remove protocol\n", __func__);
d2acc347 HX	189	}
	190
	191	module_init(tunnel6_init);
	192	module_exit(tunnel6_fini);
	193	MODULE_LICENSE("GPL");