[mirror_ubuntu-jammy-kernel.git] / net / core / lwtunnel.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lwtunnel	Infrastructure for light weight tunnels like mpls
 *
 * Authors:	Roopa Prabhu, <roopa@cumulusnetworks.com>
 */

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/lwtunnel.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/err.h>

#include <net/lwtunnel.h>
#include <net/rtnetlink.h>
#include <net/ip6_fib.h>
#include <net/rtnh.h>

#ifdef CONFIG_MODULES

static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
{
	/* Only lwt encaps implemented without using an interface for
	 * the encap need to return a string here.
	 */
	switch (encap_type) {
	case LWTUNNEL_ENCAP_MPLS:
		return "MPLS";
	case LWTUNNEL_ENCAP_ILA:
		return "ILA";
	case LWTUNNEL_ENCAP_SEG6:
		return "SEG6";
	case LWTUNNEL_ENCAP_BPF:
		return "BPF";
	case LWTUNNEL_ENCAP_SEG6_LOCAL:
		return "SEG6LOCAL";
	case LWTUNNEL_ENCAP_RPL:
		return "RPL";
	case LWTUNNEL_ENCAP_IP6:
	case LWTUNNEL_ENCAP_IP:
	case LWTUNNEL_ENCAP_NONE:
	case __LWTUNNEL_ENCAP_MAX:
		/* should not have got here */
		WARN_ON(1);
		break;
	}
	return NULL;
}

#endif /* CONFIG_MODULES */

struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
{
	struct lwtunnel_state *lws;

	lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);

	return lws;
}
EXPORT_SYMBOL_GPL(lwtunnel_state_alloc);

static const struct lwtunnel_encap_ops __rcu *
		lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;

int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
			   unsigned int num)
{
	if (num > LWTUNNEL_ENCAP_MAX)
		return -ERANGE;

	return !cmpxchg((const struct lwtunnel_encap_ops **)
			&lwtun_encaps[num],
			NULL, ops) ? 0 : -1;
}
EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops);

int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
			   unsigned int encap_type)
{
	int ret;

	if (encap_type == LWTUNNEL_ENCAP_NONE ||
	    encap_type > LWTUNNEL_ENCAP_MAX)
		return -ERANGE;

	ret = (cmpxchg((const struct lwtunnel_encap_ops **)
		       &lwtun_encaps[encap_type],
		       ops, NULL) == ops) ? 0 : -1;

	synchronize_net();

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops);

int lwtunnel_build_state(struct net *net, u16 encap_type,
			 struct nlattr *encap, unsigned int family,
			 const void *cfg, struct lwtunnel_state **lws,
			 struct netlink_ext_ack *extack)
{
	const struct lwtunnel_encap_ops *ops;
	bool found = false;
	int ret = -EINVAL;

	if (encap_type == LWTUNNEL_ENCAP_NONE ||
	    encap_type > LWTUNNEL_ENCAP_MAX) {
		NL_SET_ERR_MSG_ATTR(extack, encap,
				    "Unknown LWT encapsulation type");
		return ret;
	}

	ret = -EOPNOTSUPP;
	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[encap_type]);
	if (likely(ops && ops->build_state && try_module_get(ops->owner)))
		found = true;
	rcu_read_unlock();

	if (found) {
		ret = ops->build_state(net, encap, family, cfg, lws, extack);
		if (ret)
			module_put(ops->owner);
	} else {
		/* don't rely on -EOPNOTSUPP to detect match as build_state
		 * handlers could return it
		 */
		NL_SET_ERR_MSG_ATTR(extack, encap,
				    "LWT encapsulation type not supported");
	}

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_build_state);

int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
{
	const struct lwtunnel_encap_ops *ops;
	int ret = -EINVAL;

	if (encap_type == LWTUNNEL_ENCAP_NONE ||
	    encap_type > LWTUNNEL_ENCAP_MAX) {
		NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type");
		return ret;
	}

	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[encap_type]);
	rcu_read_unlock();
#ifdef CONFIG_MODULES
	if (!ops) {
		const char *encap_type_str = lwtunnel_encap_str(encap_type);

		if (encap_type_str) {
			__rtnl_unlock();
			request_module("rtnl-lwt-%s", encap_type_str);
			rtnl_lock();

			rcu_read_lock();
			ops = rcu_dereference(lwtun_encaps[encap_type]);
			rcu_read_unlock();
		}
	}
#endif
	ret = ops ? 0 : -EOPNOTSUPP;
	if (ret < 0)
		NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported");

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type);

int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
				   struct netlink_ext_ack *extack)
{
	struct rtnexthop *rtnh = (struct rtnexthop *)attr;
	struct nlattr *nla_entype;
	struct nlattr *attrs;
	u16 encap_type;
	int attrlen;

	while (rtnh_ok(rtnh, remaining)) {
		attrlen = rtnh_attrlen(rtnh);
		if (attrlen > 0) {
			attrs = rtnh_attrs(rtnh);
			nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);

			if (nla_entype) {
				encap_type = nla_get_u16(nla_entype);

				if (lwtunnel_valid_encap_type(encap_type,
							      extack) != 0)
					return -EOPNOTSUPP;
			}
		}
		rtnh = rtnh_next(rtnh, &remaining);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr);

void lwtstate_free(struct lwtunnel_state *lws)
{
	const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];

	if (ops->destroy_state) {
		ops->destroy_state(lws);
		kfree_rcu(lws, rcu);
	} else {
		kfree(lws);
	}
	module_put(ops->owner);
}
EXPORT_SYMBOL_GPL(lwtstate_free);

int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
			int encap_attr, int encap_type_attr)
{
	const struct lwtunnel_encap_ops *ops;
	struct nlattr *nest;
	int ret;

	if (!lwtstate)
		return 0;

	if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
	    lwtstate->type > LWTUNNEL_ENCAP_MAX)
		return 0;

	nest = nla_nest_start_noflag(skb, encap_attr);
	if (!nest)
		return -EMSGSIZE;

	ret = -EOPNOTSUPP;
	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	if (likely(ops && ops->fill_encap))
		ret = ops->fill_encap(skb, lwtstate);
	rcu_read_unlock();

	if (ret)
		goto nla_put_failure;
	nla_nest_end(skb, nest);
	ret = nla_put_u16(skb, encap_type_attr, lwtstate->type);
	if (ret)
		goto nla_put_failure;

	return 0;

nla_put_failure:
	nla_nest_cancel(skb, nest);

	return (ret == -EOPNOTSUPP ? 0 : ret);
}
EXPORT_SYMBOL_GPL(lwtunnel_fill_encap);

int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
{
	const struct lwtunnel_encap_ops *ops;
	int ret = 0;

	if (!lwtstate)
		return 0;

	if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
	    lwtstate->type > LWTUNNEL_ENCAP_MAX)
		return 0;

	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	if (likely(ops && ops->get_encap_size))
		ret = nla_total_size(ops->get_encap_size(lwtstate));
	rcu_read_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size);

int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
{
	const struct lwtunnel_encap_ops *ops;
	int ret = 0;

	if (!a && !b)
		return 0;

	if (!a || !b)
		return 1;

	if (a->type != b->type)
		return 1;

	if (a->type == LWTUNNEL_ENCAP_NONE ||
	    a->type > LWTUNNEL_ENCAP_MAX)
		return 0;

	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[a->type]);
	if (likely(ops && ops->cmp_encap))
		ret = ops->cmp_encap(a, b);
	rcu_read_unlock();

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap);

int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	const struct lwtunnel_encap_ops *ops;
	struct lwtunnel_state *lwtstate;
	int ret = -EINVAL;

	if (!dst)
		goto drop;
	lwtstate = dst->lwtstate;

	if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
	    lwtstate->type > LWTUNNEL_ENCAP_MAX)
		return 0;

	ret = -EOPNOTSUPP;
	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	if (likely(ops && ops->output))
		ret = ops->output(net, sk, skb);
	rcu_read_unlock();

	if (ret == -EOPNOTSUPP)
		goto drop;

	return ret;

drop:
	kfree_skb(skb);

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_output);

int lwtunnel_xmit(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	const struct lwtunnel_encap_ops *ops;
	struct lwtunnel_state *lwtstate;
	int ret = -EINVAL;

	if (!dst)
		goto drop;

	lwtstate = dst->lwtstate;

	if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
	    lwtstate->type > LWTUNNEL_ENCAP_MAX)
		return 0;

	ret = -EOPNOTSUPP;
	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	if (likely(ops && ops->xmit))
		ret = ops->xmit(skb);
	rcu_read_unlock();

	if (ret == -EOPNOTSUPP)
		goto drop;

	return ret;

drop:
	kfree_skb(skb);

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_xmit);

int lwtunnel_input(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	const struct lwtunnel_encap_ops *ops;
	struct lwtunnel_state *lwtstate;
	int ret = -EINVAL;

	if (!dst)
		goto drop;
	lwtstate = dst->lwtstate;

	if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
	    lwtstate->type > LWTUNNEL_ENCAP_MAX)
		return 0;

	ret = -EOPNOTSUPP;
	rcu_read_lock();
	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	if (likely(ops && ops->input))
		ret = ops->input(skb);
	rcu_read_unlock();

	if (ret == -EOPNOTSUPP)
		goto drop;

	return ret;

drop:
	kfree_skb(skb);

	return ret;
}
EXPORT_SYMBOL_GPL(lwtunnel_input);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
499a2425 RP	2	/*
	3	* lwtunnel Infrastructure for light weight tunnels like mpls
	4	*
	5	* Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
499a2425 RP	6	*/
	7
	8	#include <linux/capability.h>
	9	#include <linux/module.h>
	10	#include <linux/types.h>
	11	#include <linux/kernel.h>
	12	#include <linux/slab.h>
	13	#include <linux/uaccess.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/netdevice.h>
	16	#include <linux/lwtunnel.h>
	17	#include <linux/in.h>
	18	#include <linux/init.h>
	19	#include <linux/err.h>
	20
	21	#include <net/lwtunnel.h>
	22	#include <net/rtnetlink.h>
ffce4196	23	#include <net/ip6_fib.h>
3c618c1d	24	#include <net/rtnh.h>
499a2425	25
745041e2 RS	26	#ifdef CONFIG_MODULES
	27
	28	static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
	29	{
	30	/* Only lwt encaps implemented without using an interface for
	31	* the encap need to return a string here.
	32	*/
	33	switch (encap_type) {
	34	case LWTUNNEL_ENCAP_MPLS:
	35	return "MPLS";
	36	case LWTUNNEL_ENCAP_ILA:
	37	return "ILA";
6c8702c6 DL	38	case LWTUNNEL_ENCAP_SEG6:
6c8702c6 DL	39	return "SEG6";
3a0af8fd TG	40	case LWTUNNEL_ENCAP_BPF:
3a0af8fd TG	41	return "BPF";
d1df6fd8 DL	42	case LWTUNNEL_ENCAP_SEG6_LOCAL:
d1df6fd8 DL	43	return "SEG6LOCAL";
a7a29f9c AA	44	case LWTUNNEL_ENCAP_RPL:
a7a29f9c AA	45	return "RPL";
745041e2 RS	46	case LWTUNNEL_ENCAP_IP6:
	47	case LWTUNNEL_ENCAP_IP:
	48	case LWTUNNEL_ENCAP_NONE:
	49	case __LWTUNNEL_ENCAP_MAX:
	50	/* should not have got here */
	51	WARN_ON(1);
	52	break;
	53	}
	54	return NULL;
	55	}
	56
	57	#endif /* CONFIG_MODULES */
	58
499a2425 RP	59	struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
	60	{
	61	struct lwtunnel_state *lws;
	62
	63	lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
	64
	65	return lws;
	66	}
08bd10ff	67	EXPORT_SYMBOL_GPL(lwtunnel_state_alloc);
499a2425	68
92a99bf3	69	static const struct lwtunnel_encap_ops __rcu *
499a2425 RP	70	lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
	71
	72	int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
	73	unsigned int num)
	74	{
	75	if (num > LWTUNNEL_ENCAP_MAX)
	76	return -ERANGE;
	77
	78	return !cmpxchg((const struct lwtunnel_encap_ops **)
	79	&lwtun_encaps[num],
	80	NULL, ops) ? 0 : -1;
	81	}
08bd10ff	82	EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops);
499a2425 RP	83
	84	int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
	85	unsigned int encap_type)
	86	{
	87	int ret;
	88
	89	if (encap_type == LWTUNNEL_ENCAP_NONE \|\|
	90	encap_type > LWTUNNEL_ENCAP_MAX)
	91	return -ERANGE;
	92
	93	ret = (cmpxchg((const struct lwtunnel_encap_ops **)
	94	&lwtun_encaps[encap_type],
	95	ops, NULL) == ops) ? 0 : -1;
	96
	97	synchronize_net();
	98
	99	return ret;
	100	}
08bd10ff	101	EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops);
499a2425	102
faee6769	103	int lwtunnel_build_state(struct net *net, u16 encap_type,
127eb7cd	104	struct nlattr *encap, unsigned int family,
9ae28727 DA	105	const void cfg, struct lwtunnel_state *lws,
9ae28727 DA	106	struct netlink_ext_ack *extack)
499a2425 RP	107	{
499a2425 RP	108	const struct lwtunnel_encap_ops *ops;
9ae28727	109	bool found = false;
499a2425 RP	110	int ret = -EINVAL;
	111
	112	if (encap_type == LWTUNNEL_ENCAP_NONE \|\|
9ae28727 DA	113	encap_type > LWTUNNEL_ENCAP_MAX) {
	114	NL_SET_ERR_MSG_ATTR(extack, encap,
	115	"Unknown LWT encapsulation type");
499a2425	116	return ret;
9ae28727	117	}
499a2425 RP	118
	119	ret = -EOPNOTSUPP;
	120	rcu_read_lock();
	121	ops = rcu_dereference(lwtun_encaps[encap_type]);
3d25eabb	122	if (likely(ops && ops->build_state && try_module_get(ops->owner)))
9ae28727	123	found = true;
3d25eabb	124	rcu_read_unlock();
	125
	126	if (found) {
faee6769	127	ret = ops->build_state(net, encap, family, cfg, lws, extack);
85c81401 RS	128	if (ret)
85c81401 RS	129	module_put(ops->owner);
3d25eabb	130	} else {
	131	/* don't rely on -EOPNOTSUPP to detect match as build_state
	132	* handlers could return it
	133	*/
9ae28727 DA	134	NL_SET_ERR_MSG_ATTR(extack, encap,
	135	"LWT encapsulation type not supported");
	136	}
	137
9ed59592 DA	138	return ret;
9ed59592 DA	139	}
08bd10ff	140	EXPORT_SYMBOL_GPL(lwtunnel_build_state);
9ed59592	141
c255bd68	142	int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
9ed59592 DA	143	{
	144	const struct lwtunnel_encap_ops *ops;
	145	int ret = -EINVAL;
	146
	147	if (encap_type == LWTUNNEL_ENCAP_NONE \|\|
c255bd68 DA	148	encap_type > LWTUNNEL_ENCAP_MAX) {
c255bd68 DA	149	NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type");
9ed59592	150	return ret;
c255bd68	151	}
9ed59592 DA	152
	153	rcu_read_lock();
	154	ops = rcu_dereference(lwtun_encaps[encap_type]);
	155	rcu_read_unlock();
745041e2 RS	156	#ifdef CONFIG_MODULES
	157	if (!ops) {
	158	const char *encap_type_str = lwtunnel_encap_str(encap_type);
	159
	160	if (encap_type_str) {
9ed59592	161	__rtnl_unlock();
745041e2	162	request_module("rtnl-lwt-%s", encap_type_str);
9ed59592 DA	163	rtnl_lock();
9ed59592 DA	164
745041e2 RS	165	rcu_read_lock();
745041e2 RS	166	ops = rcu_dereference(lwtun_encaps[encap_type]);
9ed59592	167	rcu_read_unlock();
745041e2 RS	168	}
	169	}
	170	#endif
c255bd68 DA	171	ret = ops ? 0 : -EOPNOTSUPP;
	172	if (ret < 0)
	173	NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported");
	174
	175	return ret;
9ed59592	176	}
08bd10ff	177	EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type);
499a2425	178
c255bd68 DA	179	int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
c255bd68 DA	180	struct netlink_ext_ack *extack)
9ed59592 DA	181	{
	182	struct rtnexthop rtnh = (struct rtnexthop )attr;
	183	struct nlattr *nla_entype;
	184	struct nlattr *attrs;
9ed59592 DA	185	u16 encap_type;
	186	int attrlen;
	187
	188	while (rtnh_ok(rtnh, remaining)) {
	189	attrlen = rtnh_attrlen(rtnh);
	190	if (attrlen > 0) {
	191	attrs = rtnh_attrs(rtnh);
9ed59592 DA	192	nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
	193
	194	if (nla_entype) {
	195	encap_type = nla_get_u16(nla_entype);
	196
c255bd68 DA	197	if (lwtunnel_valid_encap_type(encap_type,
c255bd68 DA	198	extack) != 0)
9ed59592 DA	199	return -EOPNOTSUPP;
	200	}
	201	}
	202	rtnh = rtnh_next(rtnh, &remaining);
	203	}
	204
	205	return 0;
499a2425	206	}
08bd10ff	207	EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr);
499a2425	208
1104d9ba TH	209	void lwtstate_free(struct lwtunnel_state *lws)
	210	{
	211	const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
	212
	213	if (ops->destroy_state) {
	214	ops->destroy_state(lws);
	215	kfree_rcu(lws, rcu);
	216	} else {
	217	kfree(lws);
	218	}
85c81401	219	module_put(ops->owner);
1104d9ba	220	}
08bd10ff	221	EXPORT_SYMBOL_GPL(lwtstate_free);
1104d9ba	222
ffa8ce54 DA	223	int lwtunnel_fill_encap(struct sk_buff skb, struct lwtunnel_state lwtstate,
ffa8ce54 DA	224	int encap_attr, int encap_type_attr)
499a2425 RP	225	{
	226	const struct lwtunnel_encap_ops *ops;
	227	struct nlattr *nest;
39f37095	228	int ret;
499a2425 RP	229
	230	if (!lwtstate)
	231	return 0;
	232
	233	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	234	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	235	return 0;
	236
ae0be8de	237	nest = nla_nest_start_noflag(skb, encap_attr);
a50fe0ff	238	if (!nest)
39f37095 DC	239	return -EMSGSIZE;
	240
	241	ret = -EOPNOTSUPP;
499a2425 RP	242	rcu_read_lock();
	243	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	244	if (likely(ops && ops->fill_encap))
	245	ret = ops->fill_encap(skb, lwtstate);
	246	rcu_read_unlock();
	247
	248	if (ret)
	249	goto nla_put_failure;
	250	nla_nest_end(skb, nest);
ffa8ce54	251	ret = nla_put_u16(skb, encap_type_attr, lwtstate->type);
499a2425 RP	252	if (ret)
	253	goto nla_put_failure;
	254
	255	return 0;
	256
	257	nla_put_failure:
	258	nla_nest_cancel(skb, nest);
	259
	260	return (ret == -EOPNOTSUPP ? 0 : ret);
	261	}
08bd10ff	262	EXPORT_SYMBOL_GPL(lwtunnel_fill_encap);
499a2425 RP	263
	264	int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
	265	{
	266	const struct lwtunnel_encap_ops *ops;
	267	int ret = 0;
	268
	269	if (!lwtstate)
	270	return 0;
	271
	272	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	273	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	274	return 0;
	275
	276	rcu_read_lock();
	277	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	278	if (likely(ops && ops->get_encap_size))
	279	ret = nla_total_size(ops->get_encap_size(lwtstate));
	280	rcu_read_unlock();
	281
	282	return ret;
	283	}
08bd10ff	284	EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size);
499a2425 RP	285
	286	int lwtunnel_cmp_encap(struct lwtunnel_state a, struct lwtunnel_state b)
	287	{
	288	const struct lwtunnel_encap_ops *ops;
	289	int ret = 0;
	290
	291	if (!a && !b)
	292	return 0;
	293
	294	if (!a \|\| !b)
	295	return 1;
	296
	297	if (a->type != b->type)
	298	return 1;
	299
	300	if (a->type == LWTUNNEL_ENCAP_NONE \|\|
	301	a->type > LWTUNNEL_ENCAP_MAX)
	302	return 0;
	303
	304	rcu_read_lock();
	305	ops = rcu_dereference(lwtun_encaps[a->type]);
	306	if (likely(ops && ops->cmp_encap))
	307	ret = ops->cmp_encap(a, b);
	308	rcu_read_unlock();
	309
	310	return ret;
	311	}
08bd10ff	312	EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap);
ffce4196	313
ede2059d	314	int lwtunnel_output(struct net net, struct sock sk, struct sk_buff *skb)
ffce4196	315	{
61adedf3	316	struct dst_entry *dst = skb_dst(skb);
ffce4196	317	const struct lwtunnel_encap_ops *ops;
61adedf3	318	struct lwtunnel_state *lwtstate;
ffce4196 RP	319	int ret = -EINVAL;
ffce4196 RP	320
61adedf3	321	if (!dst)
ffce4196	322	goto drop;
61adedf3	323	lwtstate = dst->lwtstate;
ffce4196 RP	324
	325	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	326	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	327	return 0;
	328
	329	ret = -EOPNOTSUPP;
	330	rcu_read_lock();
	331	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	332	if (likely(ops && ops->output))
ede2059d	333	ret = ops->output(net, sk, skb);
ffce4196 RP	334	rcu_read_unlock();
	335
	336	if (ret == -EOPNOTSUPP)
	337	goto drop;
	338
	339	return ret;
	340
	341	drop:
e11f40b9	342	kfree_skb(skb);
ffce4196 RP	343
	344	return ret;
	345	}
08bd10ff	346	EXPORT_SYMBOL_GPL(lwtunnel_output);
25368623	347
14972cbd RP	348	int lwtunnel_xmit(struct sk_buff *skb)
	349	{
	350	struct dst_entry *dst = skb_dst(skb);
	351	const struct lwtunnel_encap_ops *ops;
	352	struct lwtunnel_state *lwtstate;
	353	int ret = -EINVAL;
	354
	355	if (!dst)
	356	goto drop;
	357
	358	lwtstate = dst->lwtstate;
	359
	360	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	361	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	362	return 0;
	363
	364	ret = -EOPNOTSUPP;
	365	rcu_read_lock();
	366	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	367	if (likely(ops && ops->xmit))
	368	ret = ops->xmit(skb);
	369	rcu_read_unlock();
	370
	371	if (ret == -EOPNOTSUPP)
	372	goto drop;
	373
	374	return ret;
	375
	376	drop:
	377	kfree_skb(skb);
	378
	379	return ret;
	380	}
08bd10ff	381	EXPORT_SYMBOL_GPL(lwtunnel_xmit);
14972cbd	382
61adedf3	383	int lwtunnel_input(struct sk_buff *skb)
25368623	384	{
61adedf3	385	struct dst_entry *dst = skb_dst(skb);
25368623	386	const struct lwtunnel_encap_ops *ops;
61adedf3	387	struct lwtunnel_state *lwtstate;
25368623 TH	388	int ret = -EINVAL;
25368623 TH	389
61adedf3	390	if (!dst)
25368623	391	goto drop;
61adedf3	392	lwtstate = dst->lwtstate;
25368623 TH	393
	394	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	395	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	396	return 0;
	397
	398	ret = -EOPNOTSUPP;
	399	rcu_read_lock();
	400	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	401	if (likely(ops && ops->input))
	402	ret = ops->input(skb);
	403	rcu_read_unlock();
	404
	405	if (ret == -EOPNOTSUPP)
	406	goto drop;
	407
	408	return ret;
	409
	410	drop:
	411	kfree_skb(skb);
	412
	413	return ret;
	414	}
08bd10ff	415	EXPORT_SYMBOL_GPL(lwtunnel_input);