[linux.git] / net / l2tp / l2tp_core.h

/*
 * L2TP internal definitions.
 *
 * Copyright (c) 2008,2009 Katalix Systems Ltd
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef _L2TP_CORE_H_
#define _L2TP_CORE_H_

/* 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)

/* Debug message categories for the DEBUG socket option */
enum {
	L2TP_MSG_DEBUG		= (1 << 0),	/* verbose debug (if
						 * compiled in) */
	L2TP_MSG_CONTROL	= (1 << 1),	/* userspace - kernel
						 * interface */
	L2TP_MSG_SEQ		= (1 << 2),	/* sequence numbers */
	L2TP_MSG_DATA		= (1 << 3),	/* data packets */
};

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		data_seq:2;	/* data sequencing level
						 * 0 => none, 1 => IP only,
						 * 2 => all
						 */
	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
						 * control of LNS. */
	int			debug;		/* bitmask of debug message
						 * categories */
	u16			vlan_id;	/* VLAN pseudowire only */
	u16			offset;		/* offset to payload */
	u16			l2specific_len;	/* Layer 2 specific length */
	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) */
	int			mtu;
	int			mru;
	char			*ifname;
};

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

	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			offset;		/* offset from end of L2TP header
						   to beginning of data */
	u16			l2specific_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 */
	atomic_t		ref_count;

	char			name[32];	/* for logging */
	char			ifname[IFNAMSIZ];
	unsigned int		data_seq:2;	/* data sequencing level
						 * 0 => none, 1 => IP only,
						 * 2 => all
						 */
	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
						 * control of LNS. */
	int			debug;		/* bitmask of debug message
						 * categories */
	int			reorder_timeout; /* configured reorder timeout
						  * (in jiffies) */
	int			reorder_skip;	/* set if skip to next nr */
	int			mtu;
	int			mru;
	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 (*ref)(struct l2tp_session *session);
	void (*deref)(struct l2tp_session *session);
#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
	void (*show)(struct seq_file *m, void *priv);
#endif
	uint8_t			priv[0];	/* 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;
};

struct l2tp_tunnel {
	int			magic;		/* Should be L2TP_TUNNEL_MAGIC */
	struct rcu_head rcu;
	rwlock_t		hlist_lock;	/* protect session_hlist */
	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;		/* Keep a list of all tunnels */
	struct net		*l2tp_net;	/* the net we belong to */

	atomic_t		ref_count;
#ifdef CONFIG_DEBUG_FS
	void (*show)(struct seq_file *m, void *arg);
#endif
	int (*recv_payload_hook)(struct sk_buff *skb);
	void (*old_sk_destruct)(struct sock *);
	struct sock		*sock;		/* Parent socket */
	int			fd;		/* Parent fd, if tunnel socket
						 * was created by userspace */
#if IS_ENABLED(CONFIG_IPV6)
	bool			v4mapped;
#endif

	struct work_struct	del_work;

	uint8_t			priv[0];	/* private data */
};

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

static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
{
	return &tunnel->priv[0];
}

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

static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
{
	struct l2tp_tunnel *tunnel;

	if (sk == NULL)
		return NULL;

	sock_hold(sk);
	tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
	if (tunnel == NULL) {
		sock_put(sk);
		goto out;
	}

	BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);

out:
	return tunnel;
}

struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel);
void l2tp_tunnel_sock_put(struct sock *sk);
struct l2tp_session *l2tp_session_find(struct net *net,
				       struct l2tp_tunnel *tunnel,
				       u32 session_id);
struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);

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);
void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
int 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);
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 (*payload_hook)(struct sk_buff *skb));
int l2tp_session_queue_purge(struct l2tp_session *session);
int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);

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);

/* Session reference counts. Incremented when code obtains a reference
 * to a session.
 */
static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
{
	atomic_inc(&session->ref_count);
}

static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
{
	if (atomic_dec_and_test(&session->ref_count))
		l2tp_session_free(session);
}

#ifdef L2TP_REFCNT_DEBUG
#define l2tp_session_inc_refcount(_s)					\
do {									\
	pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n",	\
		 __func__, __LINE__, (_s)->name,			\
		 atomic_read(&_s->ref_count));				\
	l2tp_session_inc_refcount_1(_s);				\
} while (0)
#define l2tp_session_dec_refcount(_s)					\
do {									\
	pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n",	\
		 __func__, __LINE__, (_s)->name,			\
		 atomic_read(&_s->ref_count));				\
	l2tp_session_dec_refcount_1(_s);				\
} while (0)
#else
#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
#endif

#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__)

#endif /* _L2TP_CORE_H_ */
Commit	Line	Data
fd558d18 JC	1	/*
	2	* L2TP internal definitions.
	3	*
	4	* Copyright (c) 2008,2009 Katalix Systems Ltd
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#ifndef _L2TP_CORE_H_
	12	#define _L2TP_CORE_H_
	13
	14	/* Just some random numbers */
	15	#define L2TP_TUNNEL_MAGIC 0x42114DDA
	16	#define L2TP_SESSION_MAGIC 0x0C04EB7D
	17
f7faffa3	18	/* Per tunnel, session hash table size */
fd558d18 JC	19	#define L2TP_HASH_BITS 4
	20	#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
	21
f7faffa3 JC	22	/* System-wide, session hash table size */
	23	#define L2TP_HASH_BITS_2 8
	24	#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
	25
fd558d18 JC	26	/* Debug message categories for the DEBUG socket option */
	27	enum {
	28	L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if
	29	* compiled in) */
	30	L2TP_MSG_CONTROL = (1 << 1), /* userspace - kernel
	31	* interface */
	32	L2TP_MSG_SEQ = (1 << 2), /* sequence numbers */
	33	L2TP_MSG_DATA = (1 << 3), /* data packets */
	34	};
	35
	36	struct sk_buff;
	37
	38	struct l2tp_stats {
7b7c0719 TP	39	atomic_long_t tx_packets;
	40	atomic_long_t tx_bytes;
	41	atomic_long_t tx_errors;
	42	atomic_long_t rx_packets;
	43	atomic_long_t rx_bytes;
	44	atomic_long_t rx_seq_discards;
	45	atomic_long_t rx_oos_packets;
	46	atomic_long_t rx_errors;
	47	atomic_long_t rx_cookie_discards;
fd558d18 JC	48	};
	49
	50	struct l2tp_tunnel;
	51
	52	/* Describes a session. Contains information to determine incoming
	53	* packets and transmit outgoing ones.
	54	*/
	55	struct l2tp_session_cfg {
f7faffa3	56	enum l2tp_pwtype pw_type;
95c96174	57	unsigned int data_seq:2; /* data sequencing level
fd558d18 JC	58	* 0 => none, 1 => IP only,
	59	* 2 => all
	60	*/
95c96174	61	unsigned int recv_seq:1; /* expect receive packets with
fd558d18	62	* sequence numbers? */
95c96174	63	unsigned int send_seq:1; /* send packets with sequence
fd558d18	64	* numbers? */
95c96174	65	unsigned int lns_mode:1; /* behave as LNS? LAC enables
fd558d18 JC	66	* sequence numbers under
	67	* control of LNS. */
	68	int debug; /* bitmask of debug message
	69	* categories */
309795f4	70	u16 vlan_id; /* VLAN pseudowire only */
f7faffa3 JC	71	u16 offset; /* offset to payload */
	72	u16 l2specific_len; /* Layer 2 specific length */
	73	u16 l2specific_type; /* Layer 2 specific type */
	74	u8 cookie[8]; /* optional cookie */
	75	int cookie_len; /* 0, 4 or 8 bytes */
	76	u8 peer_cookie[8]; /* peer's cookie */
	77	int peer_cookie_len; /* 0, 4 or 8 bytes */
fd558d18 JC	78	int reorder_timeout; /* configured reorder timeout
	79	* (in jiffies) */
	80	int mtu;
	81	int mru;
309795f4	82	char *ifname;
fd558d18 JC	83	};
	84
	85	struct l2tp_session {
	86	int magic; /* should be
	87	* L2TP_SESSION_MAGIC */
	88
	89	struct l2tp_tunnel tunnel; / back pointer to tunnel
	90	* context */
	91	u32 session_id;
	92	u32 peer_session_id;
f7faffa3 JC	93	u8 cookie[8];
	94	int cookie_len;
	95	u8 peer_cookie[8];
	96	int peer_cookie_len;
	97	u16 offset; /* offset from end of L2TP header
	98	to beginning of data */
	99	u16 l2specific_len;
	100	u16 l2specific_type;
	101	u16 hdr_len;
	102	u32 nr; /* session NR state (receive) */
	103	u32 ns; /* session NR state (send) */
fd558d18	104	struct sk_buff_head reorder_q; /* receive reorder queue */
8a1631d5 JC	105	u32 nr_max; /* max NR. Depends on tunnel */
8a1631d5 JC	106	u32 nr_window_size; /* NR window size */
a0dbd822 JC	107	u32 nr_oos; /* NR of last OOS packet */
	108	int nr_oos_count; /* For OOS recovery */
	109	int nr_oos_count_max;
fd558d18 JC	110	struct hlist_node hlist; /* Hash list node */
	111	atomic_t ref_count;
	112
	113	char name[32]; /* for logging */
309795f4	114	char ifname[IFNAMSIZ];
95c96174	115	unsigned int data_seq:2; /* data sequencing level
fd558d18 JC	116	* 0 => none, 1 => IP only,
	117	* 2 => all
	118	*/
95c96174	119	unsigned int recv_seq:1; /* expect receive packets with
fd558d18	120	* sequence numbers? */
95c96174	121	unsigned int send_seq:1; /* send packets with sequence
fd558d18	122	* numbers? */
95c96174	123	unsigned int lns_mode:1; /* behave as LNS? LAC enables
fd558d18 JC	124	* sequence numbers under
	125	* control of LNS. */
	126	int debug; /* bitmask of debug message
	127	* categories */
	128	int reorder_timeout; /* configured reorder timeout
	129	* (in jiffies) */
38d40b3f	130	int reorder_skip; /* set if skip to next nr */
fd558d18 JC	131	int mtu;
fd558d18 JC	132	int mru;
f7faffa3	133	enum l2tp_pwtype pwtype;
fd558d18	134	struct l2tp_stats stats;
f7faffa3	135	struct hlist_node global_hlist; /* Global hash list node */
fd558d18	136
f7faffa3	137	int (build_header)(struct l2tp_session session, void *buf);
fd558d18 JC	138	void (recv_skb)(struct l2tp_session session, struct sk_buff *skb, int data_len);
	139	void (session_close)(struct l2tp_session session);
	140	void (ref)(struct l2tp_session session);
	141	void (deref)(struct l2tp_session session);
f66ef2d0	142	#if defined(CONFIG_L2TP_DEBUGFS) \|\| defined(CONFIG_L2TP_DEBUGFS_MODULE)
0ad66140 JC	143	void (show)(struct seq_file m, void *priv);
0ad66140 JC	144	#endif
fd558d18 JC	145	uint8_t priv[0]; /* private data */
	146	};
	147
	148	/* Describes the tunnel. It contains info to track all the associated
	149	* sessions so incoming packets can be sorted out
	150	*/
	151	struct l2tp_tunnel_cfg {
	152	int debug; /* bitmask of debug message
	153	* categories */
0d76751f	154	enum l2tp_encap_type encap;
789a4a2c JC	155
	156	/* Used only for kernel-created sockets */
	157	struct in_addr local_ip;
	158	struct in_addr peer_ip;
f9bac8df CE	159	#if IS_ENABLED(CONFIG_IPV6)
	160	struct in6_addr *local_ip6;
	161	struct in6_addr *peer_ip6;
	162	#endif
789a4a2c JC	163	u16 local_udp_port;
789a4a2c JC	164	u16 peer_udp_port;
7bddd0db	165	unsigned int use_udp_checksums:1;
fd558d18 JC	166	};
	167
	168	struct l2tp_tunnel {
	169	int magic; /* Should be L2TP_TUNNEL_MAGIC */
99469c32	170	struct rcu_head rcu;
fd558d18 JC	171	rwlock_t hlist_lock; /* protect session_hlist */
	172	struct hlist_head session_hlist[L2TP_HASH_SIZE];
	173	/* hashed list of sessions,
	174	* hashed by id */
	175	u32 tunnel_id;
	176	u32 peer_tunnel_id;
	177	int version; /* 2=>L2TPv2, 3=>L2TPv3 */
	178
	179	char name[20]; /* for logging */
	180	int debug; /* bitmask of debug message
	181	* categories */
0d76751f	182	enum l2tp_encap_type encap;
fd558d18 JC	183	struct l2tp_stats stats;
	184
	185	struct list_head list; /* Keep a list of all tunnels */
	186	struct net l2tp_net; / the net we belong to */
	187
	188	atomic_t ref_count;
0ad66140 JC	189	#ifdef CONFIG_DEBUG_FS
	190	void (show)(struct seq_file m, void *arg);
	191	#endif
fd558d18 JC	192	int (recv_payload_hook)(struct sk_buff skb);
	193	void (old_sk_destruct)(struct sock );
	194	struct sock sock; / Parent socket */
80d84ef3 TP	195	int fd; /* Parent fd, if tunnel socket
80d84ef3 TP	196	* was created by userspace */
e18503f4 FC	197	#if IS_ENABLED(CONFIG_IPV6)
	198	bool v4mapped;
	199	#endif
fd558d18	200
f8ccac0e TP	201	struct work_struct del_work;
f8ccac0e TP	202
fd558d18 JC	203	uint8_t priv[0]; /* private data */
	204	};
	205
309795f4 JC	206	struct l2tp_nl_cmd_ops {
	207	int (session_create)(struct net net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
	208	int (session_delete)(struct l2tp_session session);
	209	};
	210
fd558d18 JC	211	static inline void l2tp_tunnel_priv(struct l2tp_tunnel tunnel)
	212	{
	213	return &tunnel->priv[0];
	214	}
	215
	216	static inline void l2tp_session_priv(struct l2tp_session session)
	217	{
	218	return &session->priv[0];
	219	}
	220
	221	static inline struct l2tp_tunnel l2tp_sock_to_tunnel(struct sock sk)
	222	{
	223	struct l2tp_tunnel *tunnel;
	224
	225	if (sk == NULL)
	226	return NULL;
	227
	228	sock_hold(sk);
	229	tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
	230	if (tunnel == NULL) {
	231	sock_put(sk);
	232	goto out;
	233	}
	234
	235	BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
	236
	237	out:
	238	return tunnel;
	239	}
	240
c1b1203d JP	241	struct sock l2tp_tunnel_sock_lookup(struct l2tp_tunnel tunnel);
	242	void l2tp_tunnel_sock_put(struct sock *sk);
	243	struct l2tp_session l2tp_session_find(struct net net,
	244	struct l2tp_tunnel *tunnel,
	245	u32 session_id);
	246	struct l2tp_session l2tp_session_find_nth(struct l2tp_tunnel tunnel, int nth);
	247	struct l2tp_session l2tp_session_find_by_ifname(struct net net, char *ifname);
	248	struct l2tp_tunnel l2tp_tunnel_find(struct net net, u32 tunnel_id);
	249	struct l2tp_tunnel l2tp_tunnel_find_nth(struct net net, int nth);
	250
	251	int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
	252	u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
	253	struct l2tp_tunnel **tunnelp);
	254	void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
	255	int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
	256	struct l2tp_session *l2tp_session_create(int priv_size,
	257	struct l2tp_tunnel *tunnel,
	258	u32 session_id, u32 peer_session_id,
	259	struct l2tp_session_cfg *cfg);
	260	void __l2tp_session_unhash(struct l2tp_session *session);
	261	int l2tp_session_delete(struct l2tp_session *session);
	262	void l2tp_session_free(struct l2tp_session *session);
	263	void l2tp_recv_common(struct l2tp_session session, struct sk_buff skb,
	264	unsigned char ptr, unsigned char optr, u16 hdrflags,
	265	int length, int (payload_hook)(struct sk_buff skb));
	266	int l2tp_session_queue_purge(struct l2tp_session *session);
	267	int l2tp_udp_encap_recv(struct sock sk, struct sk_buff skb);
	268
	269	int l2tp_xmit_skb(struct l2tp_session session, struct sk_buff skb,
	270	int hdr_len);
	271
	272	int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
	273	const struct l2tp_nl_cmd_ops *ops);
	274	void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
309795f4	275
fd558d18 JC	276	/* Session reference counts. Incremented when code obtains a reference
	277	* to a session.
	278	*/
	279	static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
	280	{
	281	atomic_inc(&session->ref_count);
	282	}
	283
	284	static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
	285	{
	286	if (atomic_dec_and_test(&session->ref_count))
	287	l2tp_session_free(session);
	288	}
	289
	290	#ifdef L2TP_REFCNT_DEBUG
a4ca44fa JP	291	#define l2tp_session_inc_refcount(_s) \
	292	do { \
	293	pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
	294	__func__, __LINE__, (_s)->name, \
	295	atomic_read(&_s->ref_count)); \
	296	l2tp_session_inc_refcount_1(_s); \
	297	} while (0)
	298	#define l2tp_session_dec_refcount(_s) \
	299	do { \
	300	pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
	301	__func__, __LINE__, (_s)->name, \
	302	atomic_read(&_s->ref_count)); \
	303	l2tp_session_dec_refcount_1(_s); \
	304	} while (0)
fd558d18 JC	305	#else
	306	#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
	307	#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
	308	#endif
	309
a4ca44fa JP	310	#define l2tp_printk(ptr, type, func, fmt, ...) \
	311	do { \
	312	if (((ptr)->debug) & (type)) \
	313	func(fmt, ##__VA_ARGS__); \
	314	} while (0)
	315
	316	#define l2tp_warn(ptr, type, fmt, ...) \
	317	l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
	318	#define l2tp_info(ptr, type, fmt, ...) \
	319	l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
	320	#define l2tp_dbg(ptr, type, fmt, ...) \
	321	l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
	322
fd558d18	323	#endif /* _L2TP_CORE_H_ */