[linux.git] / net / ipv6 / tunnel6.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C)2003,2004 USAGI/WIDE Project
 *
 * Authors	Mitsuru KANDA  <[email protected]>
 *		YOSHIFUJI Hideaki <[email protected]>
 */

#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 struct xfrm6_tunnel __rcu *tunnelmpls6_handlers __read_mostly;
static DEFINE_MUTEX(tunnel6_mutex);

static inline int xfrm6_tunnel_mpls_supported(void)
{
	return IS_ENABLED(CONFIG_MPLS);
}

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);

	switch (family) {
	case AF_INET6:
		pprev = &tunnel6_handlers;
		break;
	case AF_INET:
		pprev = &tunnel46_handlers;
		break;
	case AF_MPLS:
		pprev = &tunnelmpls6_handlers;
		break;
	default:
		goto err;
	}

	for (; (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);

	switch (family) {
	case AF_INET6:
		pprev = &tunnel6_handlers;
		break;
	case AF_INET:
		pprev = &tunnel46_handlers;
		break;
	case AF_MPLS:
		pprev = &tunnelmpls6_handlers;
		break;
	default:
		goto err;
	}

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

err:
	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 tunnelmpls6_rcv(struct sk_buff *skb)
{
	struct xfrm6_tunnel *handler;

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

	for_each_tunnel_rcu(tunnelmpls6_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 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;
}

#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
static int tunnel6_rcv_cb(struct sk_buff *skb, u8 proto, int err)
{
	struct xfrm6_tunnel __rcu *head;
	struct xfrm6_tunnel *handler;
	int ret;

	head = (proto == IPPROTO_IPV6) ? tunnel6_handlers : tunnel46_handlers;

	for_each_tunnel_rcu(head, handler) {
		if (handler->cb_handler) {
			ret = handler->cb_handler(skb, err);
			if (ret <= 0)
				return ret;
		}
	}

	return 0;
}

static const struct xfrm_input_afinfo tunnel6_input_afinfo = {
	.family		=	AF_INET6,
	.is_ipip	=	true,
	.callback	=	tunnel6_rcv_cb,
};
#endif

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 int 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))
			return 0;

	return -ENOENT;
}

static int 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))
			return 0;

	return -ENOENT;
}

static int tunnelmpls6_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(tunnelmpls6_handlers, handler)
		if (!handler->err_handler(skb, opt, type, code, offset, info))
			return 0;

	return -ENOENT;
}

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 const struct inet6_protocol tunnelmpls6_protocol = {
	.handler	= tunnelmpls6_rcv,
	.err_handler	= tunnelmpls6_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;
	}
	if (xfrm6_tunnel_mpls_supported() &&
	    inet6_add_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS)) {
		pr_err("%s: can't add protocol\n", __func__);
		inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
		inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP);
		return -EAGAIN;
	}
#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
	if (xfrm_input_register_afinfo(&tunnel6_input_afinfo)) {
		pr_err("%s: can't add input afinfo\n", __func__);
		inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
		inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP);
		if (xfrm6_tunnel_mpls_supported())
			inet6_del_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS);
		return -EAGAIN;
	}
#endif
	return 0;
}

static void __exit tunnel6_fini(void)
{
#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
	if (xfrm_input_unregister_afinfo(&tunnel6_input_afinfo))
		pr_err("%s: can't remove input afinfo\n", __func__);
#endif
	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__);
	if (xfrm6_tunnel_mpls_supported() &&
	    inet6_del_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS))
		pr_err("%s: can't remove protocol\n", __func__);
}

module_init(tunnel6_init);
module_exit(tunnel6_fini);
MODULE_LICENSE("GPL");
Commit	Line	Data
1ccea77e	1	// SPDX-License-Identifier: GPL-2.0-or-later
d2acc347 HX	2	/*
	3	* Copyright (C)2003,2004 USAGI/WIDE Project
	4	*
d2acc347	5	* Authors Mitsuru KANDA <[email protected]>
67ba4152	6	* YOSHIFUJI Hideaki <[email protected]>
d2acc347 HX	7	*/
d2acc347 HX	8
f3213831 JP	9	#define pr_fmt(fmt) "IPv6: " fmt
f3213831 JP	10
50fba2aa	11	#include <linux/icmpv6.h>
d2acc347 HX	12	#include <linux/init.h>
	13	#include <linux/module.h>
	14	#include <linux/mutex.h>
	15	#include <linux/netdevice.h>
	16	#include <linux/skbuff.h>
5a0e3ad6	17	#include <linux/slab.h>
50fba2aa	18	#include <net/ipv6.h>
d2acc347 HX	19	#include <net/protocol.h>
	20	#include <net/xfrm.h>
	21
6f0bcf15 ED	22	static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
6f0bcf15 ED	23	static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
f234efac	24	static struct xfrm6_tunnel __rcu *tunnelmpls6_handlers __read_mostly;
d2acc347 HX	25	static DEFINE_MUTEX(tunnel6_mutex);
d2acc347 HX	26
f234efac VF	27	static inline int xfrm6_tunnel_mpls_supported(void)
	28	{
	29	return IS_ENABLED(CONFIG_MPLS);
	30	}
	31
73d605d1	32	int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
d2acc347	33	{
6f0bcf15 ED	34	struct xfrm6_tunnel __rcu **pprev;
6f0bcf15 ED	35	struct xfrm6_tunnel *t;
d2acc347 HX	36	int ret = -EEXIST;
	37	int priority = handler->priority;
	38
	39	mutex_lock(&tunnel6_mutex);
	40
f234efac VF	41	switch (family) {
	42	case AF_INET6:
	43	pprev = &tunnel6_handlers;
	44	break;
	45	case AF_INET:
	46	pprev = &tunnel46_handlers;
	47	break;
	48	case AF_MPLS:
	49	pprev = &tunnelmpls6_handlers;
	50	break;
	51	default:
	52	goto err;
	53	}
	54
	55	for (; (t = rcu_dereference_protected(*pprev,
6f0bcf15 ED	56	lockdep_is_held(&tunnel6_mutex))) != NULL;
	57	pprev = &t->next) {
	58	if (t->priority > priority)
d2acc347	59	break;
6f0bcf15	60	if (t->priority == priority)
d2acc347 HX	61	goto err;
	62	}
	63
	64	handler->next = *pprev;
49d61e23	65	rcu_assign_pointer(*pprev, handler);
d2acc347 HX	66
	67	ret = 0;
	68
	69	err:
	70	mutex_unlock(&tunnel6_mutex);
	71
	72	return ret;
	73	}
d2acc347 HX	74	EXPORT_SYMBOL(xfrm6_tunnel_register);
d2acc347 HX	75
73d605d1	76	int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
d2acc347	77	{
6f0bcf15 ED	78	struct xfrm6_tunnel __rcu **pprev;
6f0bcf15 ED	79	struct xfrm6_tunnel *t;
d2acc347 HX	80	int ret = -ENOENT;
	81
	82	mutex_lock(&tunnel6_mutex);
	83
f234efac VF	84	switch (family) {
	85	case AF_INET6:
	86	pprev = &tunnel6_handlers;
	87	break;
	88	case AF_INET:
	89	pprev = &tunnel46_handlers;
	90	break;
	91	case AF_MPLS:
	92	pprev = &tunnelmpls6_handlers;
	93	break;
	94	default:
	95	goto err;
	96	}
	97
	98	for (; (t = rcu_dereference_protected(*pprev,
6f0bcf15 ED	99	lockdep_is_held(&tunnel6_mutex))) != NULL;
	100	pprev = &t->next) {
	101	if (t == handler) {
d2acc347 HX	102	*pprev = handler->next;
	103	ret = 0;
	104	break;
	105	}
	106	}
	107
f234efac	108	err:
d2acc347 HX	109	mutex_unlock(&tunnel6_mutex);
	110
	111	synchronize_net();
	112
	113	return ret;
	114	}
d2acc347 HX	115	EXPORT_SYMBOL(xfrm6_tunnel_deregister);
d2acc347 HX	116
875168a9 ED	117	#define for_each_tunnel_rcu(head, handler) \
	118	for (handler = rcu_dereference(head); \
	119	handler != NULL; \
	120	handler = rcu_dereference(handler->next)) \
	121
f234efac VF	122	static int tunnelmpls6_rcv(struct sk_buff *skb)
	123	{
	124	struct xfrm6_tunnel *handler;
	125
	126	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	127	goto drop;
	128
	129	for_each_tunnel_rcu(tunnelmpls6_handlers, handler)
	130	if (!handler->handler(skb))
	131	return 0;
	132
	133	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
	134
	135	drop:
	136	kfree_skb(skb);
	137	return 0;
	138	}
	139
e5bbef20	140	static int tunnel6_rcv(struct sk_buff *skb)
d2acc347	141	{
d2acc347 HX	142	struct xfrm6_tunnel *handler;
d2acc347 HX	143
50fba2aa HX	144	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	145	goto drop;
	146
875168a9	147	for_each_tunnel_rcu(tunnel6_handlers, handler)
d2acc347 HX	148	if (!handler->handler(skb))
	149	return 0;
	150
3ffe533c	151	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
50fba2aa HX	152
50fba2aa HX	153	drop:
d2acc347 HX	154	kfree_skb(skb);
	155	return 0;
	156	}
	157
86afc703 XL	158	#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
	159	static int tunnel6_rcv_cb(struct sk_buff *skb, u8 proto, int err)
	160	{
	161	struct xfrm6_tunnel __rcu *head;
	162	struct xfrm6_tunnel *handler;
	163	int ret;
	164
	165	head = (proto == IPPROTO_IPV6) ? tunnel6_handlers : tunnel46_handlers;
	166
	167	for_each_tunnel_rcu(head, handler) {
	168	if (handler->cb_handler) {
	169	ret = handler->cb_handler(skb, err);
	170	if (ret <= 0)
	171	return ret;
	172	}
	173	}
	174
	175	return 0;
	176	}
	177
	178	static const struct xfrm_input_afinfo tunnel6_input_afinfo = {
	179	.family = AF_INET6,
	180	.is_ipip = true,
	181	.callback = tunnel6_rcv_cb,
	182	};
	183	#endif
	184
e5bbef20	185	static int tunnel46_rcv(struct sk_buff *skb)
73d605d1	186	{
73d605d1 KM	187	struct xfrm6_tunnel *handler;
73d605d1 KM	188
82836372	189	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
73d605d1 KM	190	goto drop;
73d605d1 KM	191
875168a9	192	for_each_tunnel_rcu(tunnel46_handlers, handler)
73d605d1 KM	193	if (!handler->handler(skb))
	194	return 0;
	195
3ffe533c	196	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
73d605d1 KM	197
	198	drop:
	199	kfree_skb(skb);
	200	return 0;
	201	}
	202
32bbd879	203	static int tunnel6_err(struct sk_buff skb, struct inet6_skb_parm opt,
d5fdd6ba	204	u8 type, u8 code, int offset, __be32 info)
d2acc347 HX	205	{
	206	struct xfrm6_tunnel *handler;
	207
875168a9	208	for_each_tunnel_rcu(tunnel6_handlers, handler)
d2acc347	209	if (!handler->err_handler(skb, opt, type, code, offset, info))
32bbd879 SB	210	return 0;
	211
	212	return -ENOENT;
d2acc347 HX	213	}
d2acc347 HX	214
32bbd879	215	static int tunnel46_err(struct sk_buff skb, struct inet6_skb_parm opt,
ebac62fe MK	216	u8 type, u8 code, int offset, __be32 info)
	217	{
	218	struct xfrm6_tunnel *handler;
	219
	220	for_each_tunnel_rcu(tunnel46_handlers, handler)
	221	if (!handler->err_handler(skb, opt, type, code, offset, info))
32bbd879 SB	222	return 0;
	223
	224	return -ENOENT;
ebac62fe MK	225	}
ebac62fe MK	226
f234efac VF	227	static int tunnelmpls6_err(struct sk_buff skb, struct inet6_skb_parm opt,
	228	u8 type, u8 code, int offset, __be32 info)
	229	{
	230	struct xfrm6_tunnel *handler;
	231
	232	for_each_tunnel_rcu(tunnelmpls6_handlers, handler)
	233	if (!handler->err_handler(skb, opt, type, code, offset, info))
	234	return 0;
	235
	236	return -ENOENT;
	237	}
	238
41135cc8	239	static const struct inet6_protocol tunnel6_protocol = {
d2acc347 HX	240	.handler = tunnel6_rcv,
	241	.err_handler = tunnel6_err,
	242	.flags = INET6_PROTO_NOPOLICY\|INET6_PROTO_FINAL,
	243	};
	244
41135cc8	245	static const struct inet6_protocol tunnel46_protocol = {
73d605d1	246	.handler = tunnel46_rcv,
ebac62fe	247	.err_handler = tunnel46_err,
73d605d1 KM	248	.flags = INET6_PROTO_NOPOLICY\|INET6_PROTO_FINAL,
	249	};
	250
f234efac VF	251	static const struct inet6_protocol tunnelmpls6_protocol = {
	252	.handler = tunnelmpls6_rcv,
	253	.err_handler = tunnelmpls6_err,
	254	.flags = INET6_PROTO_NOPOLICY\|INET6_PROTO_FINAL,
	255	};
	256
d2acc347 HX	257	static int __init tunnel6_init(void)
	258	{
	259	if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
f3213831	260	pr_err("%s: can't add protocol\n", __func__);
d2acc347 HX	261	return -EAGAIN;
d2acc347 HX	262	}
73d605d1	263	if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
f3213831	264	pr_err("%s: can't add protocol\n", __func__);
73d605d1 KM	265	inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
	266	return -EAGAIN;
	267	}
f234efac VF	268	if (xfrm6_tunnel_mpls_supported() &&
	269	inet6_add_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS)) {
	270	pr_err("%s: can't add protocol\n", __func__);
	271	inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
	272	inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP);
	273	return -EAGAIN;
	274	}
86afc703 XL	275	#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
	276	if (xfrm_input_register_afinfo(&tunnel6_input_afinfo)) {
	277	pr_err("%s: can't add input afinfo\n", __func__);
	278	inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
	279	inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP);
	280	if (xfrm6_tunnel_mpls_supported())
	281	inet6_del_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS);
	282	return -EAGAIN;
	283	}
	284	#endif
d2acc347 HX	285	return 0;
	286	}
	287
	288	static void __exit tunnel6_fini(void)
	289	{
86afc703 XL	290	#if IS_ENABLED(CONFIG_INET6_XFRM_TUNNEL)
	291	if (xfrm_input_unregister_afinfo(&tunnel6_input_afinfo))
	292	pr_err("%s: can't remove input afinfo\n", __func__);
	293	#endif
73d605d1	294	if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
f3213831	295	pr_err("%s: can't remove protocol\n", __func__);
d2acc347	296	if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
f3213831	297	pr_err("%s: can't remove protocol\n", __func__);
f234efac VF	298	if (xfrm6_tunnel_mpls_supported() &&
	299	inet6_del_protocol(&tunnelmpls6_protocol, IPPROTO_MPLS))
	300	pr_err("%s: can't remove protocol\n", __func__);
d2acc347 HX	301	}
	302
	303	module_init(tunnel6_init);
	304	module_exit(tunnel6_fini);
	305	MODULE_LICENSE("GPL");