[deliverable/linux.git] / net / ipv6 / xfrm6_protocol.c

/* xfrm6_protocol.c - Generic xfrm protocol multiplexer for ipv6.
 *
 * Copyright (C) 2013 secunet Security Networks AG
 *
 * Author:
 * Steffen Klassert <steffen.klassert@secunet.com>
 *
 * Based on:
 * net/ipv4/xfrm4_protocol.c
 *
 *	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.
 */

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

static struct xfrm6_protocol __rcu *esp6_handlers __read_mostly;
static struct xfrm6_protocol __rcu *ah6_handlers __read_mostly;
static struct xfrm6_protocol __rcu *ipcomp6_handlers __read_mostly;
static DEFINE_MUTEX(xfrm6_protocol_mutex);

static inline struct xfrm6_protocol __rcu **proto_handlers(u8 protocol)
{
	switch (protocol) {
	case IPPROTO_ESP:
		return &esp6_handlers;
	case IPPROTO_AH:
		return &ah6_handlers;
	case IPPROTO_COMP:
		return &ipcomp6_handlers;
	}

	return NULL;
}

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

int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
{
	int ret;
	struct xfrm6_protocol *handler;

	for_each_protocol_rcu(*proto_handlers(protocol), handler)
		if ((ret = handler->cb_handler(skb, err)) <= 0)
			return ret;

	return 0;
}
EXPORT_SYMBOL(xfrm6_rcv_cb);

static int xfrm6_esp_rcv(struct sk_buff *skb)
{
	int ret;
	struct xfrm6_protocol *handler;

	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;

	for_each_protocol_rcu(esp6_handlers, handler)
		if ((ret = handler->handler(skb)) != -EINVAL)
			return ret;

	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);

	kfree_skb(skb);
	return 0;
}

static void xfrm6_esp_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			  u8 type, u8 code, int offset, __be32 info)
{
	struct xfrm6_protocol *handler;

	for_each_protocol_rcu(esp6_handlers, handler)
		if (!handler->err_handler(skb, opt, type, code, offset, info))
			break;
}

static int xfrm6_ah_rcv(struct sk_buff *skb)
{
	int ret;
	struct xfrm6_protocol *handler;

	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;

	for_each_protocol_rcu(ah6_handlers, handler)
		if ((ret = handler->handler(skb)) != -EINVAL)
			return ret;

	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);

	kfree_skb(skb);
	return 0;
}

static void xfrm6_ah_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			 u8 type, u8 code, int offset, __be32 info)
{
	struct xfrm6_protocol *handler;

	for_each_protocol_rcu(ah6_handlers, handler)
		if (!handler->err_handler(skb, opt, type, code, offset, info))
			break;
}

static int xfrm6_ipcomp_rcv(struct sk_buff *skb)
{
	int ret;
	struct xfrm6_protocol *handler;

	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;

	for_each_protocol_rcu(ipcomp6_handlers, handler)
		if ((ret = handler->handler(skb)) != -EINVAL)
			return ret;

	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);

	kfree_skb(skb);
	return 0;
}

static void xfrm6_ipcomp_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			     u8 type, u8 code, int offset, __be32 info)
{
	struct xfrm6_protocol *handler;

	for_each_protocol_rcu(ipcomp6_handlers, handler)
		if (!handler->err_handler(skb, opt, type, code, offset, info))
			break;
}

static const struct inet6_protocol esp6_protocol = {
	.handler	=	xfrm6_esp_rcv,
	.err_handler	=	xfrm6_esp_err,
	.flags		=	INET6_PROTO_NOPOLICY,
};

static const struct inet6_protocol ah6_protocol = {
	.handler	=	xfrm6_ah_rcv,
	.err_handler	=	xfrm6_ah_err,
	.flags		=	INET6_PROTO_NOPOLICY,
};

static const struct inet6_protocol ipcomp6_protocol = {
	.handler	=	xfrm6_ipcomp_rcv,
	.err_handler	=	xfrm6_ipcomp_err,
	.flags		=	INET6_PROTO_NOPOLICY,
};

static struct xfrm_input_afinfo xfrm6_input_afinfo = {
	.family		=	AF_INET6,
	.owner		=	THIS_MODULE,
	.callback	=	xfrm6_rcv_cb,
};

static inline const struct inet6_protocol *netproto(unsigned char protocol)
{
	switch (protocol) {
	case IPPROTO_ESP:
		return &esp6_protocol;
	case IPPROTO_AH:
		return &ah6_protocol;
	case IPPROTO_COMP:
		return &ipcomp6_protocol;
	}

	return NULL;
}

int xfrm6_protocol_register(struct xfrm6_protocol *handler,
			    unsigned char protocol)
{
	struct xfrm6_protocol __rcu **pprev;
	struct xfrm6_protocol *t;
	bool add_netproto = false;

	int ret = -EEXIST;
	int priority = handler->priority;

	mutex_lock(&xfrm6_protocol_mutex);

	if (!rcu_dereference_protected(*proto_handlers(protocol),
				       lockdep_is_held(&xfrm6_protocol_mutex)))
		add_netproto = true;

	for (pprev = proto_handlers(protocol);
	     (t = rcu_dereference_protected(*pprev,
			lockdep_is_held(&xfrm6_protocol_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(&xfrm6_protocol_mutex);

	if (add_netproto) {
		if (inet6_add_protocol(netproto(protocol), protocol)) {
			pr_err("%s: can't add protocol\n", __func__);
			ret = -EAGAIN;
		}
	}

	return ret;
}
EXPORT_SYMBOL(xfrm6_protocol_register);

int xfrm6_protocol_deregister(struct xfrm6_protocol *handler,
			      unsigned char protocol)
{
	struct xfrm6_protocol __rcu **pprev;
	struct xfrm6_protocol *t;
	int ret = -ENOENT;

	mutex_lock(&xfrm6_protocol_mutex);

	for (pprev = proto_handlers(protocol);
	     (t = rcu_dereference_protected(*pprev,
			lockdep_is_held(&xfrm6_protocol_mutex))) != NULL;
	     pprev = &t->next) {
		if (t == handler) {
			*pprev = handler->next;
			ret = 0;
			break;
		}
	}

	if (!rcu_dereference_protected(*proto_handlers(protocol),
				       lockdep_is_held(&xfrm6_protocol_mutex))) {
		if (inet6_del_protocol(netproto(protocol), protocol) < 0) {
			pr_err("%s: can't remove protocol\n", __func__);
			ret = -EAGAIN;
		}
	}

	mutex_unlock(&xfrm6_protocol_mutex);

	synchronize_net();

	return ret;
}
EXPORT_SYMBOL(xfrm6_protocol_deregister);

int __init xfrm6_protocol_init(void)
{
	return xfrm_input_register_afinfo(&xfrm6_input_afinfo);
}

void xfrm6_protocol_fini(void)
{
	xfrm_input_unregister_afinfo(&xfrm6_input_afinfo);
}
Commit	Line	Data
7e14ea15 SK	1	/* xfrm6_protocol.c - Generic xfrm protocol multiplexer for ipv6.
	2	*
	3	* Copyright (C) 2013 secunet Security Networks AG
	4	*
	5	* Author:
	6	* Steffen Klassert <steffen.klassert@secunet.com>
	7	*
	8	* Based on:
	9	* net/ipv4/xfrm4_protocol.c
	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the License, or (at your option) any later version.
	15	*/
	16
	17	#include <linux/init.h>
	18	#include <linux/mutex.h>
	19	#include <linux/skbuff.h>
	20	#include <linux/icmpv6.h>
	21	#include <net/ipv6.h>
	22	#include <net/protocol.h>
	23	#include <net/xfrm.h>
	24
	25	static struct xfrm6_protocol __rcu *esp6_handlers __read_mostly;
	26	static struct xfrm6_protocol __rcu *ah6_handlers __read_mostly;
	27	static struct xfrm6_protocol __rcu *ipcomp6_handlers __read_mostly;
	28	static DEFINE_MUTEX(xfrm6_protocol_mutex);
	29
	30	static inline struct xfrm6_protocol __rcu **proto_handlers(u8 protocol)
	31	{
	32	switch (protocol) {
	33	case IPPROTO_ESP:
	34	return &esp6_handlers;
	35	case IPPROTO_AH:
	36	return &ah6_handlers;
	37	case IPPROTO_COMP:
	38	return &ipcomp6_handlers;
	39	}
	40
	41	return NULL;
	42	}
	43
	44	#define for_each_protocol_rcu(head, handler) \
	45	for (handler = rcu_dereference(head); \
	46	handler != NULL; \
	47	handler = rcu_dereference(handler->next)) \
	48
	49	int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
	50	{
	51	int ret;
	52	struct xfrm6_protocol *handler;
	53
	54	for_each_protocol_rcu(*proto_handlers(protocol), handler)
	55	if ((ret = handler->cb_handler(skb, err)) <= 0)
	56	return ret;
	57
	58	return 0;
	59	}
	60	EXPORT_SYMBOL(xfrm6_rcv_cb);
	61
	62	static int xfrm6_esp_rcv(struct sk_buff *skb)
	63	{
	64	int ret;
65	struct xfrm6_protocol *handler;
66
67	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
68
69	for_each_protocol_rcu(esp6_handlers, handler)
70	if ((ret = handler->handler(skb)) != -EINVAL)
71	return ret;
72
73	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
74
75	kfree_skb(skb);
76	return 0;
77	}
78
79	static void xfrm6_esp_err(struct sk_buff skb, struct inet6_skb_parm opt,
80	u8 type, u8 code, int offset, __be32 info)
81	{
82	struct xfrm6_protocol *handler;
83
84	for_each_protocol_rcu(esp6_handlers, handler)
85	if (!handler->err_handler(skb, opt, type, code, offset, info))
86	break;
87	}
88
89	static int xfrm6_ah_rcv(struct sk_buff *skb)
90	{
91	int ret;
92	struct xfrm6_protocol *handler;
93
94	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
95
96	for_each_protocol_rcu(ah6_handlers, handler)
97	if ((ret = handler->handler(skb)) != -EINVAL)
98	return ret;
99
100	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
101
102	kfree_skb(skb);
103	return 0;
104	}
105
106	static void xfrm6_ah_err(struct sk_buff skb, struct inet6_skb_parm opt,
107	u8 type, u8 code, int offset, __be32 info)
108	{
109	struct xfrm6_protocol *handler;
110
111	for_each_protocol_rcu(ah6_handlers, handler)
112	if (!handler->err_handler(skb, opt, type, code, offset, info))
113	break;
114	}
115
116	static int xfrm6_ipcomp_rcv(struct sk_buff *skb)
117	{
118	int ret;
119	struct xfrm6_protocol *handler;
120
121	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
122
123	for_each_protocol_rcu(ipcomp6_handlers, handler)
124	if ((ret = handler->handler(skb)) != -EINVAL)
125	return ret;
126
127	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
128
129	kfree_skb(skb);
130	return 0;
131	}
132
133	static void xfrm6_ipcomp_err(struct sk_buff skb, struct inet6_skb_parm opt,
134	u8 type, u8 code, int offset, __be32 info)
135	{
136	struct xfrm6_protocol *handler;
137
138	for_each_protocol_rcu(ipcomp6_handlers, handler)
139	if (!handler->err_handler(skb, opt, type, code, offset, info))
140	break;
141	}
142
143	static const struct inet6_protocol esp6_protocol = {
144	.handler = xfrm6_esp_rcv,
145	.err_handler = xfrm6_esp_err,
146	.flags = INET6_PROTO_NOPOLICY,
147	};
148
149	static const struct inet6_protocol ah6_protocol = {
150	.handler = xfrm6_ah_rcv,
151	.err_handler = xfrm6_ah_err,
152	.flags = INET6_PROTO_NOPOLICY,
153	};
154
155	static const struct inet6_protocol ipcomp6_protocol = {
156	.handler = xfrm6_ipcomp_rcv,
157	.err_handler = xfrm6_ipcomp_err,
158	.flags = INET6_PROTO_NOPOLICY,
159	};
160
161	static struct xfrm_input_afinfo xfrm6_input_afinfo = {
162	.family = AF_INET6,
163	.owner = THIS_MODULE,
164	.callback = xfrm6_rcv_cb,
165	};
166
167	static inline const struct inet6_protocol *netproto(unsigned char protocol)
168	{
169	switch (protocol) {
170	case IPPROTO_ESP:
171	return &esp6_protocol;
172	case IPPROTO_AH:
173	return &ah6_protocol;
174	case IPPROTO_COMP:
175	return &ipcomp6_protocol;
176	}
177
178	return NULL;
179	}
180
181	int xfrm6_protocol_register(struct xfrm6_protocol *handler,
182	unsigned char protocol)
183	{
184	struct xfrm6_protocol __rcu **pprev;
185	struct xfrm6_protocol *t;
186	bool add_netproto = false;
187
188	int ret = -EEXIST;
189	int priority = handler->priority;
190
191	mutex_lock(&xfrm6_protocol_mutex);
192
193	if (!rcu_dereference_protected(*proto_handlers(protocol),
194	lockdep_is_held(&xfrm6_protocol_mutex)))
195	add_netproto = true;
196
197	for (pprev = proto_handlers(protocol);
198	(t = rcu_dereference_protected(*pprev,
199	lockdep_is_held(&xfrm6_protocol_mutex))) != NULL;
200	pprev = &t->next) {
201	if (t->priority < priority)
202	break;
203	if (t->priority == priority)
204	goto err;
205	}
206
207	handler->next = *pprev;
208	rcu_assign_pointer(*pprev, handler);
209
210	ret = 0;
211
212	err:
213	mutex_unlock(&xfrm6_protocol_mutex);
214
215	if (add_netproto) {
216	if (inet6_add_protocol(netproto(protocol), protocol)) {
217	pr_err("%s: can't add protocol\n", __func__);
218	ret = -EAGAIN;
219	}
220	}
221
222	return ret;
223	}
224	EXPORT_SYMBOL(xfrm6_protocol_register);
225
226	int xfrm6_protocol_deregister(struct xfrm6_protocol *handler,
227	unsigned char protocol)
228	{
229	struct xfrm6_protocol __rcu **pprev;
230	struct xfrm6_protocol *t;
231	int ret = -ENOENT;
232
233	mutex_lock(&xfrm6_protocol_mutex);
234
235	for (pprev = proto_handlers(protocol);
236	(t = rcu_dereference_protected(*pprev,
237	lockdep_is_held(&xfrm6_protocol_mutex))) != NULL;
238	pprev = &t->next) {
239	if (t == handler) {
240	*pprev = handler->next;
241	ret = 0;
242	break;
243	}
244	}
245
246	if (!rcu_dereference_protected(*proto_handlers(protocol),
247	lockdep_is_held(&xfrm6_protocol_mutex))) {
248	if (inet6_del_protocol(netproto(protocol), protocol) < 0) {
249	pr_err("%s: can't remove protocol\n", __func__);
250	ret = -EAGAIN;
251	}
252	}
253
254	mutex_unlock(&xfrm6_protocol_mutex);
255
256	synchronize_net();
257
258	return ret;
259	}
260	EXPORT_SYMBOL(xfrm6_protocol_deregister);
261
262	int __init xfrm6_protocol_init(void)
263	{
264	return xfrm_input_register_afinfo(&xfrm6_input_afinfo);
265	}
266
267	void xfrm6_protocol_fini(void)
268	{
269	xfrm_input_unregister_afinfo(&xfrm6_input_afinfo);
270	}