[linux-2.6-block.git] / net / l2tp / l2tp_core.h

/* SPDX-License-Identifier: GPL-2.0-only */
/* L2TP internal definitions.
 *
 * Copyright (c) 2008,2009 Katalix Systems Ltd
 */
#include <linux/refcount.h>

#ifndef _L2TP_CORE_H_
#define _L2TP_CORE_H_

#include <net/dst.h>
#include <net/sock.h>

#ifdef CONFIG_XFRM
#include <net/xfrm.h>
#endif

/* Just some random numbers */
#define L2TP_TUNNEL_MAGIC	0x42114DDA
#define L2TP_SESSION_MAGIC	0x0C04EB7D

/* Per tunnel, session hash table size */
#define L2TP_HASH_BITS	4
#define L2TP_HASH_SIZE	(1 << L2TP_HASH_BITS)

/* System-wide, session hash table size */
#define L2TP_HASH_BITS_2	8
#define L2TP_HASH_SIZE_2	(1 << L2TP_HASH_BITS_2)

struct sk_buff;

struct l2tp_stats {
	atomic_long_t		tx_packets;
	atomic_long_t		tx_bytes;
	atomic_long_t		tx_errors;
	atomic_long_t		rx_packets;
	atomic_long_t		rx_bytes;
	atomic_long_t		rx_seq_discards;
	atomic_long_t		rx_oos_packets;
	atomic_long_t		rx_errors;
	atomic_long_t		rx_cookie_discards;
};

struct l2tp_tunnel;

/* Describes a session. Contains information to determine incoming
 * packets and transmit outgoing ones.
 */
struct l2tp_session_cfg {
	enum l2tp_pwtype	pw_type;
	unsigned int		recv_seq:1;	/* expect receive packets with sequence numbers? */
	unsigned int		send_seq:1;	/* send packets with sequence numbers? */
	unsigned int		lns_mode:1;	/* behave as LNS?
						 * LAC enables sequence numbers under LNS control.
						 */
	int			debug;		/* bitmask of debug message categories */
	u16			l2specific_type; /* Layer 2 specific type */
	u8			cookie[8];	/* optional cookie */
	int			cookie_len;	/* 0, 4 or 8 bytes */
	u8			peer_cookie[8];	/* peer's cookie */
	int			peer_cookie_len; /* 0, 4 or 8 bytes */
	int			reorder_timeout; /* configured reorder timeout (in jiffies) */
	char			*ifname;
};

struct l2tp_session {
	int			magic;		/* should be L2TP_SESSION_MAGIC */
	long			dead;

	struct l2tp_tunnel	*tunnel;	/* back pointer to tunnel context */
	u32			session_id;
	u32			peer_session_id;
	u8			cookie[8];
	int			cookie_len;
	u8			peer_cookie[8];
	int			peer_cookie_len;
	u16			l2specific_type;
	u16			hdr_len;
	u32			nr;		/* session NR state (receive) */
	u32			ns;		/* session NR state (send) */
	struct sk_buff_head	reorder_q;	/* receive reorder queue */
	u32			nr_max;		/* max NR. Depends on tunnel */
	u32			nr_window_size;	/* NR window size */
	u32			nr_oos;		/* NR of last OOS packet */
	int			nr_oos_count;	/* for OOS recovery */
	int			nr_oos_count_max;
	struct hlist_node	hlist;		/* hash list node */
	refcount_t		ref_count;

	char			name[32];	/* for logging */
	char			ifname[IFNAMSIZ];
	unsigned int		recv_seq:1;	/* expect receive packets with sequence numbers? */
	unsigned int		send_seq:1;	/* send packets with sequence numbers? */
	unsigned int		lns_mode:1;	/* behave as LNS?
						 * LAC enables sequence numbers under LNS control.
						 */
	int			debug;		/* bitmask of debug message categories */
	int			reorder_timeout; /* configured reorder timeout (in jiffies) */
	int			reorder_skip;	/* set if skip to next nr */
	enum l2tp_pwtype	pwtype;
	struct l2tp_stats	stats;
	struct hlist_node	global_hlist;	/* global hash list node */

	int (*build_header)(struct l2tp_session *session, void *buf);
	void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
	void (*session_close)(struct l2tp_session *session);
	void (*show)(struct seq_file *m, void *priv);
	u8			priv[];		/* private data */
};

/* Describes the tunnel. It contains info to track all the associated
 * sessions so incoming packets can be sorted out
 */
struct l2tp_tunnel_cfg {
	int			debug;		/* bitmask of debug message categories */
	enum l2tp_encap_type	encap;

	/* Used only for kernel-created sockets */
	struct in_addr		local_ip;
	struct in_addr		peer_ip;
#if IS_ENABLED(CONFIG_IPV6)
	struct in6_addr		*local_ip6;
	struct in6_addr		*peer_ip6;
#endif
	u16			local_udp_port;
	u16			peer_udp_port;
	unsigned int		use_udp_checksums:1,
				udp6_zero_tx_checksums:1,
				udp6_zero_rx_checksums:1;
};

struct l2tp_tunnel {
	int			magic;		/* Should be L2TP_TUNNEL_MAGIC */

	unsigned long		dead;

	struct rcu_head rcu;
	rwlock_t		hlist_lock;	/* protect session_hlist */
	bool			acpt_newsess;	/* indicates whether this tunnel accepts
						 * new sessions. Protected by hlist_lock.
						 */
	struct hlist_head	session_hlist[L2TP_HASH_SIZE];
						/* hashed list of sessions, hashed by id */
	u32			tunnel_id;
	u32			peer_tunnel_id;
	int			version;	/* 2=>L2TPv2, 3=>L2TPv3 */

	char			name[20];	/* for logging */
	int			debug;		/* bitmask of debug message categories */
	enum l2tp_encap_type	encap;
	struct l2tp_stats	stats;

	struct list_head	list;		/* list node on per-namespace list of tunnels */
	struct net		*l2tp_net;	/* the net we belong to */

	refcount_t		ref_count;
	void (*old_sk_destruct)(struct sock *);
	struct sock		*sock;		/* parent socket */
	int			fd;		/* parent fd, if tunnel socket was created
						 * by userspace
						 */

	struct work_struct	del_work;
};

struct l2tp_nl_cmd_ops {
	int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
			      u32 session_id, u32 peer_session_id,
			      struct l2tp_session_cfg *cfg);
	int (*session_delete)(struct l2tp_session *session);
};

static inline void *l2tp_session_priv(struct l2tp_session *session)
{
	return &session->priv[0];
}

struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel,
					     u32 session_id);

void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);

struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id);
struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
						const char *ifname);

int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
		       u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
		       struct l2tp_tunnel **tunnelp);
int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
			 struct l2tp_tunnel_cfg *cfg);

void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
struct l2tp_session *l2tp_session_create(int priv_size,
					 struct l2tp_tunnel *tunnel,
					 u32 session_id, u32 peer_session_id,
					 struct l2tp_session_cfg *cfg);
int l2tp_session_register(struct l2tp_session *session,
			  struct l2tp_tunnel *tunnel);

void __l2tp_session_unhash(struct l2tp_session *session);
int l2tp_session_delete(struct l2tp_session *session);
void l2tp_session_free(struct l2tp_session *session);
void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
		      unsigned char *ptr, unsigned char *optr, u16 hdrflags,
		      int length);
int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
void l2tp_session_set_header_len(struct l2tp_session *session, int version);

int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
		  int hdr_len);

int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
			 const struct l2tp_nl_cmd_ops *ops);
void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);

static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
{
	refcount_inc(&tunnel->ref_count);
}

static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
{
	if (refcount_dec_and_test(&tunnel->ref_count))
		l2tp_tunnel_free(tunnel);
}

/* Session reference counts. Incremented when code obtains a reference
 * to a session.
 */
static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
{
	refcount_inc(&session->ref_count);
}

static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
{
	if (refcount_dec_and_test(&session->ref_count))
		l2tp_session_free(session);
}

static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
{
	switch (session->l2specific_type) {
	case L2TP_L2SPECTYPE_DEFAULT:
		return 4;
	case L2TP_L2SPECTYPE_NONE:
	default:
		return 0;
	}
}

static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
{
	struct dst_entry *dst;
	u32 mtu;

	dst = sk_dst_get(tunnel->sock);
	if (!dst)
		return 0;

	mtu = dst_mtu(dst);
	dst_release(dst);

	return mtu;
}

#ifdef CONFIG_XFRM
static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
{
	struct sock *sk = tunnel->sock;

	return sk && (rcu_access_pointer(sk->sk_policy[0]) ||
		      rcu_access_pointer(sk->sk_policy[1]));
}
#else
static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
{
	return false;
}
#endif

static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
					       unsigned char **ptr, unsigned char **optr)
{
	int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);

	if (opt_len > 0) {
		int off = *ptr - *optr;

		if (!pskb_may_pull(skb, off + opt_len))
			return -1;

		if (skb->data != *optr) {
			*optr = skb->data;
			*ptr = skb->data + off;
		}
	}

	return 0;
}

#define l2tp_printk(ptr, type, func, fmt, ...)				\
do {									\
	if (((ptr)->debug) & (type))					\
		func(fmt, ##__VA_ARGS__);				\
} while (0)

#define l2tp_warn(ptr, type, fmt, ...)					\
	l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
#define l2tp_info(ptr, type, fmt, ...)					\
	l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
#define l2tp_dbg(ptr, type, fmt, ...)					\
	l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)

#define MODULE_ALIAS_L2TP_PWTYPE(type) \
	MODULE_ALIAS("net-l2tp-type-" __stringify(type))

#endif /* _L2TP_CORE_H_ */
Commit	Line	Data
d2912cb1	1	/* SPDX-License-Identifier: GPL-2.0-only */
20dcb110	2	/* L2TP internal definitions.
fd558d18 JC	3	*
fd558d18 JC	4	* Copyright (c) 2008,2009 Katalix Systems Ltd
fd558d18	5	*/
fbea9e07	6	#include <linux/refcount.h>
fd558d18 JC	7
	8	#ifndef _L2TP_CORE_H_
	9	#define _L2TP_CORE_H_
	10
1f5cd2a0 GN	11	#include <net/dst.h>
	12	#include <net/sock.h>
	13
d6a61ec9 GN	14	#ifdef CONFIG_XFRM
	15	#include <net/xfrm.h>
	16	#endif
	17
fd558d18 JC	18	/* Just some random numbers */
	19	#define L2TP_TUNNEL_MAGIC 0x42114DDA
	20	#define L2TP_SESSION_MAGIC 0x0C04EB7D
	21
f7faffa3	22	/* Per tunnel, session hash table size */
fd558d18 JC	23	#define L2TP_HASH_BITS 4
	24	#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
	25
f7faffa3 JC	26	/* System-wide, session hash table size */
	27	#define L2TP_HASH_BITS_2 8
	28	#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
	29
fd558d18 JC	30	struct sk_buff;
	31
	32	struct l2tp_stats {
7b7c0719 TP	33	atomic_long_t tx_packets;
	34	atomic_long_t tx_bytes;
	35	atomic_long_t tx_errors;
	36	atomic_long_t rx_packets;
	37	atomic_long_t rx_bytes;
	38	atomic_long_t rx_seq_discards;
	39	atomic_long_t rx_oos_packets;
	40	atomic_long_t rx_errors;
	41	atomic_long_t rx_cookie_discards;
fd558d18 JC	42	};
	43
	44	struct l2tp_tunnel;
	45
	46	/* Describes a session. Contains information to determine incoming
	47	* packets and transmit outgoing ones.
	48	*/
	49	struct l2tp_session_cfg {
f7faffa3	50	enum l2tp_pwtype pw_type;
20dcb110 TP	51	unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */
	52	unsigned int send_seq:1; /* send packets with sequence numbers? */
	53	unsigned int lns_mode:1; /* behave as LNS?
	54	* LAC enables sequence numbers under LNS control.
	55	*/
	56	int debug; /* bitmask of debug message categories */
f7faffa3 JC	57	u16 l2specific_type; /* Layer 2 specific type */
	58	u8 cookie[8]; /* optional cookie */
	59	int cookie_len; /* 0, 4 or 8 bytes */
	60	u8 peer_cookie[8]; /* peer's cookie */
	61	int peer_cookie_len; /* 0, 4 or 8 bytes */
20dcb110	62	int reorder_timeout; /* configured reorder timeout (in jiffies) */
309795f4	63	char *ifname;
fd558d18 JC	64	};
	65
	66	struct l2tp_session {
20dcb110	67	int magic; /* should be L2TP_SESSION_MAGIC */
b228a940	68	long dead;
fd558d18	69
20dcb110	70	struct l2tp_tunnel tunnel; / back pointer to tunnel context */
fd558d18 JC	71	u32 session_id;
fd558d18 JC	72	u32 peer_session_id;
f7faffa3 JC	73	u8 cookie[8];
	74	int cookie_len;
	75	u8 peer_cookie[8];
	76	int peer_cookie_len;
f7faffa3 JC	77	u16 l2specific_type;
	78	u16 hdr_len;
	79	u32 nr; /* session NR state (receive) */
	80	u32 ns; /* session NR state (send) */
fd558d18	81	struct sk_buff_head reorder_q; /* receive reorder queue */
8a1631d5 JC	82	u32 nr_max; /* max NR. Depends on tunnel */
8a1631d5 JC	83	u32 nr_window_size; /* NR window size */
a0dbd822	84	u32 nr_oos; /* NR of last OOS packet */
20dcb110	85	int nr_oos_count; /* for OOS recovery */
a0dbd822	86	int nr_oos_count_max;
20dcb110	87	struct hlist_node hlist; /* hash list node */
f00c854c	88	refcount_t ref_count;
fd558d18 JC	89
fd558d18 JC	90	char name[32]; /* for logging */
309795f4	91	char ifname[IFNAMSIZ];
20dcb110 TP	92	unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */
	93	unsigned int send_seq:1; /* send packets with sequence numbers? */
	94	unsigned int lns_mode:1; /* behave as LNS?
	95	* LAC enables sequence numbers under LNS control.
	96	*/
	97	int debug; /* bitmask of debug message categories */
	98	int reorder_timeout; /* configured reorder timeout (in jiffies) */
38d40b3f	99	int reorder_skip; /* set if skip to next nr */
f7faffa3	100	enum l2tp_pwtype pwtype;
fd558d18	101	struct l2tp_stats stats;
20dcb110	102	struct hlist_node global_hlist; /* global hash list node */
fd558d18	103
f7faffa3	104	int (build_header)(struct l2tp_session session, void *buf);
fd558d18 JC	105	void (recv_skb)(struct l2tp_session session, struct sk_buff *skb, int data_len);
fd558d18 JC	106	void (session_close)(struct l2tp_session session);
0ad66140	107	void (show)(struct seq_file m, void *priv);
20dcb110	108	u8 priv[]; /* private data */
fd558d18 JC	109	};
	110
	111	/* Describes the tunnel. It contains info to track all the associated
	112	* sessions so incoming packets can be sorted out
	113	*/
	114	struct l2tp_tunnel_cfg {
20dcb110	115	int debug; /* bitmask of debug message categories */
0d76751f	116	enum l2tp_encap_type encap;
789a4a2c JC	117
	118	/* Used only for kernel-created sockets */
	119	struct in_addr local_ip;
	120	struct in_addr peer_ip;
f9bac8df CE	121	#if IS_ENABLED(CONFIG_IPV6)
	122	struct in6_addr *local_ip6;
	123	struct in6_addr *peer_ip6;
	124	#endif
789a4a2c JC	125	u16 local_udp_port;
789a4a2c JC	126	u16 peer_udp_port;
6b649fea TH	127	unsigned int use_udp_checksums:1,
	128	udp6_zero_tx_checksums:1,
	129	udp6_zero_rx_checksums:1;
fd558d18 JC	130	};
	131
	132	struct l2tp_tunnel {
	133	int magic; /* Should be L2TP_TUNNEL_MAGIC */
62b982ee SD	134
	135	unsigned long dead;
	136
99469c32	137	struct rcu_head rcu;
fd558d18	138	rwlock_t hlist_lock; /* protect session_hlist */
20dcb110 TP	139	bool acpt_newsess; /* indicates whether this tunnel accepts
20dcb110 TP	140	* new sessions. Protected by hlist_lock.
f3c66d4e	141	*/
fd558d18	142	struct hlist_head session_hlist[L2TP_HASH_SIZE];
20dcb110	143	/* hashed list of sessions, hashed by id */
fd558d18 JC	144	u32 tunnel_id;
	145	u32 peer_tunnel_id;
	146	int version; /* 2=>L2TPv2, 3=>L2TPv3 */
	147
	148	char name[20]; /* for logging */
20dcb110	149	int debug; /* bitmask of debug message categories */
0d76751f	150	enum l2tp_encap_type encap;
fd558d18 JC	151	struct l2tp_stats stats;
fd558d18 JC	152
20dcb110	153	struct list_head list; /* list node on per-namespace list of tunnels */
fd558d18 JC	154	struct net l2tp_net; / the net we belong to */
fd558d18 JC	155
fbea9e07	156	refcount_t ref_count;
fd558d18	157	void (old_sk_destruct)(struct sock );
20dcb110 TP	158	struct sock sock; / parent socket */
	159	int fd; /* parent fd, if tunnel socket was created
	160	* by userspace
	161	*/
fd558d18	162
f8ccac0e	163	struct work_struct del_work;
fd558d18 JC	164	};
fd558d18 JC	165
309795f4	166	struct l2tp_nl_cmd_ops {
f026bc29 GN	167	int (session_create)(struct net net, struct l2tp_tunnel *tunnel,
	168	u32 session_id, u32 peer_session_id,
	169	struct l2tp_session_cfg *cfg);
309795f4 JC	170	int (session_delete)(struct l2tp_session session);
	171	};
	172
fd558d18 JC	173	static inline void l2tp_session_priv(struct l2tp_session session)
	174	{
	175	return &session->priv[0];
	176	}
	177
54652eb1	178	struct l2tp_tunnel l2tp_tunnel_get(const struct net net, u32 tunnel_id);
5846c131	179	struct l2tp_tunnel l2tp_tunnel_get_nth(const struct net net, int nth);
01e28b92 GN	180	struct l2tp_session l2tp_tunnel_get_session(struct l2tp_tunnel tunnel,
01e28b92 GN	181	u32 session_id);
5846c131	182
d00fa9ad	183	void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
54652eb1	184
01e28b92	185	struct l2tp_session l2tp_session_get(const struct net net, u32 session_id);
a4346210	186	struct l2tp_session l2tp_session_get_nth(struct l2tp_tunnel tunnel, int nth);
9aaef50c	187	struct l2tp_session l2tp_session_get_by_ifname(const struct net net,
a4346210	188	const char *ifname);
c1b1203d JP	189
	190	int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
	191	u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
	192	struct l2tp_tunnel **tunnelp);
6b9f3423 GN	193	int l2tp_tunnel_register(struct l2tp_tunnel tunnel, struct net net,
	194	struct l2tp_tunnel_cfg *cfg);
	195
62b982ee	196	void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
c1b1203d JP	197	struct l2tp_session *l2tp_session_create(int priv_size,
	198	struct l2tp_tunnel *tunnel,
	199	u32 session_id, u32 peer_session_id,
	200	struct l2tp_session_cfg *cfg);
3953ae7b GN	201	int l2tp_session_register(struct l2tp_session *session,
	202	struct l2tp_tunnel *tunnel);
	203
c1b1203d JP	204	void __l2tp_session_unhash(struct l2tp_session *session);
	205	int l2tp_session_delete(struct l2tp_session *session);
	206	void l2tp_session_free(struct l2tp_session *session);
	207	void l2tp_recv_common(struct l2tp_session session, struct sk_buff skb,
	208	unsigned char ptr, unsigned char optr, u16 hdrflags,
2b139e6b	209	int length);
c1b1203d	210	int l2tp_udp_encap_recv(struct sock sk, struct sk_buff skb);
bb5016ea	211	void l2tp_session_set_header_len(struct l2tp_session *session, int version);
c1b1203d JP	212
	213	int l2tp_xmit_skb(struct l2tp_session session, struct sk_buff skb,
	214	int hdr_len);
	215
	216	int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
	217	const struct l2tp_nl_cmd_ops *ops);
	218	void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
72fb96e7	219	int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
309795f4	220
54652eb1 GN	221	static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
	222	{
	223	refcount_inc(&tunnel->ref_count);
	224	}
	225
	226	static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
	227	{
	228	if (refcount_dec_and_test(&tunnel->ref_count))
d00fa9ad	229	l2tp_tunnel_free(tunnel);
54652eb1 GN	230	}
54652eb1 GN	231
fd558d18 JC	232	/* Session reference counts. Incremented when code obtains a reference
	233	* to a session.
	234	*/
9ff672ba	235	static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
fd558d18	236	{
f00c854c	237	refcount_inc(&session->ref_count);
fd558d18 JC	238	}
fd558d18 JC	239
9ff672ba	240	static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
fd558d18	241	{
f00c854c	242	if (refcount_dec_and_test(&session->ref_count))
fd558d18 JC	243	l2tp_session_free(session);
	244	}
	245
62e7b6a5 LB	246	static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
	247	{
	248	switch (session->l2specific_type) {
	249	case L2TP_L2SPECTYPE_DEFAULT:
	250	return 4;
	251	case L2TP_L2SPECTYPE_NONE:
	252	default:
	253	return 0;
	254	}
	255	}
	256
1f5cd2a0 GN	257	static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
	258	{
	259	struct dst_entry *dst;
	260	u32 mtu;
	261
	262	dst = sk_dst_get(tunnel->sock);
	263	if (!dst)
	264	return 0;
	265
	266	mtu = dst_mtu(dst);
	267	dst_release(dst);
	268
	269	return mtu;
	270	}
	271
d6a61ec9 GN	272	#ifdef CONFIG_XFRM
	273	static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
	274	{
	275	struct sock *sk = tunnel->sock;
	276
	277	return sk && (rcu_access_pointer(sk->sk_policy[0]) \|\|
	278	rcu_access_pointer(sk->sk_policy[1]));
	279	}
	280	#else
	281	static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
	282	{
	283	return false;
	284	}
	285	#endif
	286
4522a70d JW	287	static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session session, struct sk_buff skb,
	288	unsigned char ptr, unsigned char optr)
	289	{
	290	int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
	291
	292	if (opt_len > 0) {
	293	int off = ptr - optr;
	294
	295	if (!pskb_may_pull(skb, off + opt_len))
	296	return -1;
	297
	298	if (skb->data != *optr) {
	299	*optr = skb->data;
	300	*ptr = skb->data + off;
	301	}
	302	}
	303
	304	return 0;
	305	}
	306
a4ca44fa JP	307	#define l2tp_printk(ptr, type, func, fmt, ...) \
	308	do { \
	309	if (((ptr)->debug) & (type)) \
	310	func(fmt, ##__VA_ARGS__); \
	311	} while (0)
	312
	313	#define l2tp_warn(ptr, type, fmt, ...) \
	314	l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
	315	#define l2tp_info(ptr, type, fmt, ...) \
	316	l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
	317	#define l2tp_dbg(ptr, type, fmt, ...) \
	318	l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
	319
f1f39f91	320	#define MODULE_ALIAS_L2TP_PWTYPE(type) \
	321	MODULE_ALIAS("net-l2tp-type-" __stringify(type))
	322
fd558d18	323	#endif /* _L2TP_CORE_H_ */