[linux-block.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>

DEFINE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_enabled);

#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_IOAM6:
		return "IOAM6";
	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) {
				if (nla_len(nla_entype) < sizeof(u16)) {
					NL_SET_ERR_MSG(extack, "Invalid RTA_ENCAP_TYPE");
					return -EINVAL;
				}
				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
7a3f5b0d RS	26	DEFINE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
	27	EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_enabled);
	28
745041e2 RS	29	#ifdef CONFIG_MODULES
	30
	31	static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
	32	{
	33	/* Only lwt encaps implemented without using an interface for
	34	* the encap need to return a string here.
	35	*/
	36	switch (encap_type) {
	37	case LWTUNNEL_ENCAP_MPLS:
	38	return "MPLS";
	39	case LWTUNNEL_ENCAP_ILA:
	40	return "ILA";
6c8702c6 DL	41	case LWTUNNEL_ENCAP_SEG6:
6c8702c6 DL	42	return "SEG6";
3a0af8fd TG	43	case LWTUNNEL_ENCAP_BPF:
3a0af8fd TG	44	return "BPF";
d1df6fd8 DL	45	case LWTUNNEL_ENCAP_SEG6_LOCAL:
d1df6fd8 DL	46	return "SEG6LOCAL";
a7a29f9c AA	47	case LWTUNNEL_ENCAP_RPL:
a7a29f9c AA	48	return "RPL";
3edede08 JI	49	case LWTUNNEL_ENCAP_IOAM6:
3edede08 JI	50	return "IOAM6";
745041e2 RS	51	case LWTUNNEL_ENCAP_IP6:
	52	case LWTUNNEL_ENCAP_IP:
	53	case LWTUNNEL_ENCAP_NONE:
	54	case __LWTUNNEL_ENCAP_MAX:
	55	/* should not have got here */
	56	WARN_ON(1);
	57	break;
	58	}
	59	return NULL;
	60	}
	61
	62	#endif /* CONFIG_MODULES */
	63
499a2425 RP	64	struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
	65	{
	66	struct lwtunnel_state *lws;
	67
	68	lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
	69
	70	return lws;
	71	}
08bd10ff	72	EXPORT_SYMBOL_GPL(lwtunnel_state_alloc);
499a2425	73
92a99bf3	74	static const struct lwtunnel_encap_ops __rcu *
499a2425 RP	75	lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
	76
	77	int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
	78	unsigned int num)
	79	{
	80	if (num > LWTUNNEL_ENCAP_MAX)
	81	return -ERANGE;
	82
	83	return !cmpxchg((const struct lwtunnel_encap_ops **)
	84	&lwtun_encaps[num],
	85	NULL, ops) ? 0 : -1;
	86	}
08bd10ff	87	EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops);
499a2425 RP	88
	89	int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
	90	unsigned int encap_type)
	91	{
	92	int ret;
	93
	94	if (encap_type == LWTUNNEL_ENCAP_NONE \|\|
	95	encap_type > LWTUNNEL_ENCAP_MAX)
	96	return -ERANGE;
	97
	98	ret = (cmpxchg((const struct lwtunnel_encap_ops **)
	99	&lwtun_encaps[encap_type],
	100	ops, NULL) == ops) ? 0 : -1;
	101
	102	synchronize_net();
	103
	104	return ret;
	105	}
08bd10ff	106	EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops);
499a2425	107
faee6769	108	int lwtunnel_build_state(struct net *net, u16 encap_type,
127eb7cd	109	struct nlattr *encap, unsigned int family,
9ae28727 DA	110	const void cfg, struct lwtunnel_state *lws,
9ae28727 DA	111	struct netlink_ext_ack *extack)
499a2425 RP	112	{
499a2425 RP	113	const struct lwtunnel_encap_ops *ops;
9ae28727	114	bool found = false;
499a2425 RP	115	int ret = -EINVAL;
	116
	117	if (encap_type == LWTUNNEL_ENCAP_NONE \|\|
9ae28727 DA	118	encap_type > LWTUNNEL_ENCAP_MAX) {
	119	NL_SET_ERR_MSG_ATTR(extack, encap,
	120	"Unknown LWT encapsulation type");
499a2425	121	return ret;
9ae28727	122	}
499a2425 RP	123
	124	ret = -EOPNOTSUPP;
	125	rcu_read_lock();
	126	ops = rcu_dereference(lwtun_encaps[encap_type]);
3d25eabb	127	if (likely(ops && ops->build_state && try_module_get(ops->owner)))
9ae28727	128	found = true;
3d25eabb	129	rcu_read_unlock();
	130
	131	if (found) {
faee6769	132	ret = ops->build_state(net, encap, family, cfg, lws, extack);
85c81401 RS	133	if (ret)
85c81401 RS	134	module_put(ops->owner);
3d25eabb	135	} else {
	136	/* don't rely on -EOPNOTSUPP to detect match as build_state
	137	* handlers could return it
	138	*/
9ae28727 DA	139	NL_SET_ERR_MSG_ATTR(extack, encap,
	140	"LWT encapsulation type not supported");
	141	}
	142
9ed59592 DA	143	return ret;
9ed59592 DA	144	}
08bd10ff	145	EXPORT_SYMBOL_GPL(lwtunnel_build_state);
9ed59592	146
c255bd68	147	int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
9ed59592 DA	148	{
	149	const struct lwtunnel_encap_ops *ops;
	150	int ret = -EINVAL;
	151
	152	if (encap_type == LWTUNNEL_ENCAP_NONE \|\|
c255bd68 DA	153	encap_type > LWTUNNEL_ENCAP_MAX) {
c255bd68 DA	154	NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type");
9ed59592	155	return ret;
c255bd68	156	}
9ed59592 DA	157
	158	rcu_read_lock();
	159	ops = rcu_dereference(lwtun_encaps[encap_type]);
	160	rcu_read_unlock();
745041e2 RS	161	#ifdef CONFIG_MODULES
	162	if (!ops) {
	163	const char *encap_type_str = lwtunnel_encap_str(encap_type);
	164
	165	if (encap_type_str) {
9ed59592	166	__rtnl_unlock();
745041e2	167	request_module("rtnl-lwt-%s", encap_type_str);
9ed59592 DA	168	rtnl_lock();
9ed59592 DA	169
745041e2 RS	170	rcu_read_lock();
745041e2 RS	171	ops = rcu_dereference(lwtun_encaps[encap_type]);
9ed59592	172	rcu_read_unlock();
745041e2 RS	173	}
	174	}
	175	#endif
c255bd68 DA	176	ret = ops ? 0 : -EOPNOTSUPP;
	177	if (ret < 0)
	178	NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported");
	179
	180	return ret;
9ed59592	181	}
08bd10ff	182	EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type);
499a2425	183
c255bd68 DA	184	int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
c255bd68 DA	185	struct netlink_ext_ack *extack)
9ed59592 DA	186	{
	187	struct rtnexthop rtnh = (struct rtnexthop )attr;
	188	struct nlattr *nla_entype;
	189	struct nlattr *attrs;
9ed59592 DA	190	u16 encap_type;
	191	int attrlen;
	192
	193	while (rtnh_ok(rtnh, remaining)) {
	194	attrlen = rtnh_attrlen(rtnh);
	195	if (attrlen > 0) {
	196	attrs = rtnh_attrs(rtnh);
9ed59592 DA	197	nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
	198
	199	if (nla_entype) {
8bda81a4 DA	200	if (nla_len(nla_entype) < sizeof(u16)) {
	201	NL_SET_ERR_MSG(extack, "Invalid RTA_ENCAP_TYPE");
	202	return -EINVAL;
	203	}
9ed59592 DA	204	encap_type = nla_get_u16(nla_entype);
9ed59592 DA	205
c255bd68 DA	206	if (lwtunnel_valid_encap_type(encap_type,
c255bd68 DA	207	extack) != 0)
9ed59592 DA	208	return -EOPNOTSUPP;
	209	}
	210	}
	211	rtnh = rtnh_next(rtnh, &remaining);
	212	}
	213
	214	return 0;
499a2425	215	}
08bd10ff	216	EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr);
499a2425	217
1104d9ba TH	218	void lwtstate_free(struct lwtunnel_state *lws)
	219	{
	220	const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
	221
	222	if (ops->destroy_state) {
	223	ops->destroy_state(lws);
	224	kfree_rcu(lws, rcu);
	225	} else {
	226	kfree(lws);
	227	}
85c81401	228	module_put(ops->owner);
1104d9ba	229	}
08bd10ff	230	EXPORT_SYMBOL_GPL(lwtstate_free);
1104d9ba	231
ffa8ce54 DA	232	int lwtunnel_fill_encap(struct sk_buff skb, struct lwtunnel_state lwtstate,
ffa8ce54 DA	233	int encap_attr, int encap_type_attr)
499a2425 RP	234	{
	235	const struct lwtunnel_encap_ops *ops;
	236	struct nlattr *nest;
39f37095	237	int ret;
499a2425 RP	238
	239	if (!lwtstate)
	240	return 0;
	241
	242	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	243	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	244	return 0;
	245
ae0be8de	246	nest = nla_nest_start_noflag(skb, encap_attr);
a50fe0ff	247	if (!nest)
39f37095 DC	248	return -EMSGSIZE;
	249
	250	ret = -EOPNOTSUPP;
499a2425 RP	251	rcu_read_lock();
	252	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	253	if (likely(ops && ops->fill_encap))
	254	ret = ops->fill_encap(skb, lwtstate);
	255	rcu_read_unlock();
	256
	257	if (ret)
	258	goto nla_put_failure;
	259	nla_nest_end(skb, nest);
ffa8ce54	260	ret = nla_put_u16(skb, encap_type_attr, lwtstate->type);
499a2425 RP	261	if (ret)
	262	goto nla_put_failure;
	263
	264	return 0;
	265
	266	nla_put_failure:
	267	nla_nest_cancel(skb, nest);
	268
	269	return (ret == -EOPNOTSUPP ? 0 : ret);
	270	}
08bd10ff	271	EXPORT_SYMBOL_GPL(lwtunnel_fill_encap);
499a2425 RP	272
	273	int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
	274	{
	275	const struct lwtunnel_encap_ops *ops;
	276	int ret = 0;
	277
	278	if (!lwtstate)
	279	return 0;
	280
	281	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	282	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	283	return 0;
	284
	285	rcu_read_lock();
	286	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	287	if (likely(ops && ops->get_encap_size))
	288	ret = nla_total_size(ops->get_encap_size(lwtstate));
	289	rcu_read_unlock();
	290
	291	return ret;
	292	}
08bd10ff	293	EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size);
499a2425 RP	294
	295	int lwtunnel_cmp_encap(struct lwtunnel_state a, struct lwtunnel_state b)
	296	{
	297	const struct lwtunnel_encap_ops *ops;
	298	int ret = 0;
	299
	300	if (!a && !b)
	301	return 0;
	302
	303	if (!a \|\| !b)
	304	return 1;
	305
	306	if (a->type != b->type)
	307	return 1;
	308
	309	if (a->type == LWTUNNEL_ENCAP_NONE \|\|
	310	a->type > LWTUNNEL_ENCAP_MAX)
	311	return 0;
	312
	313	rcu_read_lock();
	314	ops = rcu_dereference(lwtun_encaps[a->type]);
	315	if (likely(ops && ops->cmp_encap))
	316	ret = ops->cmp_encap(a, b);
	317	rcu_read_unlock();
	318
	319	return ret;
	320	}
08bd10ff	321	EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap);
ffce4196	322
ede2059d	323	int lwtunnel_output(struct net net, struct sock sk, struct sk_buff *skb)
ffce4196	324	{
61adedf3	325	struct dst_entry *dst = skb_dst(skb);
ffce4196	326	const struct lwtunnel_encap_ops *ops;
61adedf3	327	struct lwtunnel_state *lwtstate;
ffce4196 RP	328	int ret = -EINVAL;
ffce4196 RP	329
61adedf3	330	if (!dst)
ffce4196	331	goto drop;
61adedf3	332	lwtstate = dst->lwtstate;
ffce4196 RP	333
	334	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	335	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	336	return 0;
	337
	338	ret = -EOPNOTSUPP;
	339	rcu_read_lock();
	340	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	341	if (likely(ops && ops->output))
ede2059d	342	ret = ops->output(net, sk, skb);
ffce4196 RP	343	rcu_read_unlock();
	344
	345	if (ret == -EOPNOTSUPP)
	346	goto drop;
	347
	348	return ret;
	349
	350	drop:
e11f40b9	351	kfree_skb(skb);
ffce4196 RP	352
	353	return ret;
	354	}
08bd10ff	355	EXPORT_SYMBOL_GPL(lwtunnel_output);
25368623	356
14972cbd RP	357	int lwtunnel_xmit(struct sk_buff *skb)
	358	{
	359	struct dst_entry *dst = skb_dst(skb);
	360	const struct lwtunnel_encap_ops *ops;
	361	struct lwtunnel_state *lwtstate;
	362	int ret = -EINVAL;
	363
	364	if (!dst)
	365	goto drop;
	366
	367	lwtstate = dst->lwtstate;
	368
	369	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	370	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	371	return 0;
	372
	373	ret = -EOPNOTSUPP;
	374	rcu_read_lock();
	375	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	376	if (likely(ops && ops->xmit))
	377	ret = ops->xmit(skb);
	378	rcu_read_unlock();
	379
	380	if (ret == -EOPNOTSUPP)
	381	goto drop;
	382
	383	return ret;
	384
	385	drop:
	386	kfree_skb(skb);
	387
	388	return ret;
	389	}
08bd10ff	390	EXPORT_SYMBOL_GPL(lwtunnel_xmit);
14972cbd	391
61adedf3	392	int lwtunnel_input(struct sk_buff *skb)
25368623	393	{
61adedf3	394	struct dst_entry *dst = skb_dst(skb);
25368623	395	const struct lwtunnel_encap_ops *ops;
61adedf3	396	struct lwtunnel_state *lwtstate;
25368623 TH	397	int ret = -EINVAL;
25368623 TH	398
61adedf3	399	if (!dst)
25368623	400	goto drop;
61adedf3	401	lwtstate = dst->lwtstate;
25368623 TH	402
	403	if (lwtstate->type == LWTUNNEL_ENCAP_NONE \|\|
	404	lwtstate->type > LWTUNNEL_ENCAP_MAX)
	405	return 0;
	406
	407	ret = -EOPNOTSUPP;
	408	rcu_read_lock();
	409	ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
	410	if (likely(ops && ops->input))
	411	ret = ops->input(skb);
	412	rcu_read_unlock();
	413
	414	if (ret == -EOPNOTSUPP)
	415	goto drop;
	416
	417	return ret;
	418
	419	drop:
	420	kfree_skb(skb);
	421
	422	return ret;
	423	}
08bd10ff	424	EXPORT_SYMBOL_GPL(lwtunnel_input);