[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
						 * control of LNS. */
	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
						 * 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 */
	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);
	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,
				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;		/* Keep a list of all 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 */
fd558d18 JC	2	/*
	3	* L2TP internal definitions.
	4	*
	5	* Copyright (c) 2008,2009 Katalix Systems Ltd
fd558d18	6	*/
fbea9e07	7	#include <linux/refcount.h>
fd558d18 JC	8
	9	#ifndef _L2TP_CORE_H_
	10	#define _L2TP_CORE_H_
	11
1f5cd2a0 GN	12	#include <net/dst.h>
	13	#include <net/sock.h>
	14
d6a61ec9 GN	15	#ifdef CONFIG_XFRM
	16	#include <net/xfrm.h>
	17	#endif
	18
fd558d18 JC	19	/* Just some random numbers */
	20	#define L2TP_TUNNEL_MAGIC 0x42114DDA
	21	#define L2TP_SESSION_MAGIC 0x0C04EB7D
	22
f7faffa3	23	/* Per tunnel, session hash table size */
fd558d18 JC	24	#define L2TP_HASH_BITS 4
	25	#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
	26
f7faffa3 JC	27	/* System-wide, session hash table size */
	28	#define L2TP_HASH_BITS_2 8
	29	#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
	30
fd558d18 JC	31	struct sk_buff;
	32
	33	struct l2tp_stats {
7b7c0719 TP	34	atomic_long_t tx_packets;
	35	atomic_long_t tx_bytes;
	36	atomic_long_t tx_errors;
	37	atomic_long_t rx_packets;
	38	atomic_long_t rx_bytes;
	39	atomic_long_t rx_seq_discards;
	40	atomic_long_t rx_oos_packets;
	41	atomic_long_t rx_errors;
	42	atomic_long_t rx_cookie_discards;
fd558d18 JC	43	};
	44
	45	struct l2tp_tunnel;
	46
	47	/* Describes a session. Contains information to determine incoming
	48	* packets and transmit outgoing ones.
	49	*/
	50	struct l2tp_session_cfg {
f7faffa3	51	enum l2tp_pwtype pw_type;
95c96174	52	unsigned int recv_seq:1; /* expect receive packets with
fd558d18	53	* sequence numbers? */
95c96174	54	unsigned int send_seq:1; /* send packets with sequence
fd558d18	55	* numbers? */
95c96174	56	unsigned int lns_mode:1; /* behave as LNS? LAC enables
fd558d18 JC	57	* sequence numbers under
	58	* control of LNS. */
	59	int debug; /* bitmask of debug message
	60	* categories */
f7faffa3 JC	61	u16 l2specific_type; /* Layer 2 specific type */
	62	u8 cookie[8]; /* optional cookie */
	63	int cookie_len; /* 0, 4 or 8 bytes */
	64	u8 peer_cookie[8]; /* peer's cookie */
	65	int peer_cookie_len; /* 0, 4 or 8 bytes */
fd558d18 JC	66	int reorder_timeout; /* configured reorder timeout
fd558d18 JC	67	* (in jiffies) */
309795f4	68	char *ifname;
fd558d18 JC	69	};
	70
	71	struct l2tp_session {
	72	int magic; /* should be
	73	* L2TP_SESSION_MAGIC */
b228a940	74	long dead;
fd558d18 JC	75
	76	struct l2tp_tunnel tunnel; / back pointer to tunnel
	77	* context */
	78	u32 session_id;
	79	u32 peer_session_id;
f7faffa3 JC	80	u8 cookie[8];
	81	int cookie_len;
	82	u8 peer_cookie[8];
	83	int peer_cookie_len;
f7faffa3 JC	84	u16 l2specific_type;
	85	u16 hdr_len;
	86	u32 nr; /* session NR state (receive) */
	87	u32 ns; /* session NR state (send) */
fd558d18	88	struct sk_buff_head reorder_q; /* receive reorder queue */
8a1631d5 JC	89	u32 nr_max; /* max NR. Depends on tunnel */
8a1631d5 JC	90	u32 nr_window_size; /* NR window size */
a0dbd822 JC	91	u32 nr_oos; /* NR of last OOS packet */
	92	int nr_oos_count; /* For OOS recovery */
	93	int nr_oos_count_max;
fd558d18	94	struct hlist_node hlist; /* Hash list node */
f00c854c	95	refcount_t ref_count;
fd558d18 JC	96
fd558d18 JC	97	char name[32]; /* for logging */
309795f4	98	char ifname[IFNAMSIZ];
95c96174	99	unsigned int recv_seq:1; /* expect receive packets with
fd558d18	100	* sequence numbers? */
95c96174	101	unsigned int send_seq:1; /* send packets with sequence
fd558d18	102	* numbers? */
95c96174	103	unsigned int lns_mode:1; /* behave as LNS? LAC enables
fd558d18 JC	104	* sequence numbers under
	105	* control of LNS. */
	106	int debug; /* bitmask of debug message
	107	* categories */
	108	int reorder_timeout; /* configured reorder timeout
	109	* (in jiffies) */
38d40b3f	110	int reorder_skip; /* set if skip to next nr */
f7faffa3	111	enum l2tp_pwtype pwtype;
fd558d18	112	struct l2tp_stats stats;
f7faffa3	113	struct hlist_node global_hlist; /* Global hash list node */
fd558d18	114
f7faffa3	115	int (build_header)(struct l2tp_session session, void *buf);
fd558d18 JC	116	void (recv_skb)(struct l2tp_session session, struct sk_buff *skb, int data_len);
fd558d18 JC	117	void (session_close)(struct l2tp_session session);
0ad66140	118	void (show)(struct seq_file m, void *priv);
fd558d18 JC	119	uint8_t priv[0]; /* private data */
	120	};
	121
	122	/* Describes the tunnel. It contains info to track all the associated
	123	* sessions so incoming packets can be sorted out
	124	*/
	125	struct l2tp_tunnel_cfg {
	126	int debug; /* bitmask of debug message
	127	* categories */
0d76751f	128	enum l2tp_encap_type encap;
789a4a2c JC	129
	130	/* Used only for kernel-created sockets */
	131	struct in_addr local_ip;
	132	struct in_addr peer_ip;
f9bac8df CE	133	#if IS_ENABLED(CONFIG_IPV6)
	134	struct in6_addr *local_ip6;
	135	struct in6_addr *peer_ip6;
	136	#endif
789a4a2c JC	137	u16 local_udp_port;
789a4a2c JC	138	u16 peer_udp_port;
6b649fea TH	139	unsigned int use_udp_checksums:1,
	140	udp6_zero_tx_checksums:1,
	141	udp6_zero_rx_checksums:1;
fd558d18 JC	142	};
	143
	144	struct l2tp_tunnel {
	145	int magic; /* Should be L2TP_TUNNEL_MAGIC */
62b982ee SD	146
	147	unsigned long dead;
	148
99469c32	149	struct rcu_head rcu;
fd558d18	150	rwlock_t hlist_lock; /* protect session_hlist */
f3c66d4e GN	151	bool acpt_newsess; /* Indicates whether this
	152	* tunnel accepts new sessions.
	153	* Protected by hlist_lock.
	154	*/
fd558d18 JC	155	struct hlist_head session_hlist[L2TP_HASH_SIZE];
	156	/* hashed list of sessions,
	157	* hashed by id */
	158	u32 tunnel_id;
	159	u32 peer_tunnel_id;
	160	int version; /* 2=>L2TPv2, 3=>L2TPv3 */
	161
	162	char name[20]; /* for logging */
	163	int debug; /* bitmask of debug message
	164	* categories */
0d76751f	165	enum l2tp_encap_type encap;
fd558d18 JC	166	struct l2tp_stats stats;
	167
	168	struct list_head list; /* Keep a list of all tunnels */
	169	struct net l2tp_net; / the net we belong to */
	170
fbea9e07	171	refcount_t ref_count;
fd558d18 JC	172	void (old_sk_destruct)(struct sock );
fd558d18 JC	173	struct sock sock; / Parent socket */
80d84ef3 TP	174	int fd; /* Parent fd, if tunnel socket
80d84ef3 TP	175	* was created by userspace */
fd558d18	176
f8ccac0e	177	struct work_struct del_work;
fd558d18 JC	178	};
fd558d18 JC	179
309795f4	180	struct l2tp_nl_cmd_ops {
f026bc29 GN	181	int (session_create)(struct net net, struct l2tp_tunnel *tunnel,
	182	u32 session_id, u32 peer_session_id,
	183	struct l2tp_session_cfg *cfg);
309795f4 JC	184	int (session_delete)(struct l2tp_session session);
	185	};
	186
fd558d18 JC	187	static inline void l2tp_session_priv(struct l2tp_session session)
	188	{
	189	return &session->priv[0];
	190	}
	191
54652eb1	192	struct l2tp_tunnel l2tp_tunnel_get(const struct net net, u32 tunnel_id);
5846c131	193	struct l2tp_tunnel l2tp_tunnel_get_nth(const struct net net, int nth);
01e28b92 GN	194	struct l2tp_session l2tp_tunnel_get_session(struct l2tp_tunnel tunnel,
01e28b92 GN	195	u32 session_id);
5846c131	196
d00fa9ad	197	void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
54652eb1	198
01e28b92	199	struct l2tp_session l2tp_session_get(const struct net net, u32 session_id);
a4346210	200	struct l2tp_session l2tp_session_get_nth(struct l2tp_tunnel tunnel, int nth);
9aaef50c	201	struct l2tp_session l2tp_session_get_by_ifname(const struct net net,
a4346210	202	const char *ifname);
c1b1203d JP	203
	204	int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
	205	u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
	206	struct l2tp_tunnel **tunnelp);
6b9f3423 GN	207	int l2tp_tunnel_register(struct l2tp_tunnel tunnel, struct net net,
	208	struct l2tp_tunnel_cfg *cfg);
	209
62b982ee	210	void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
c1b1203d JP	211	struct l2tp_session *l2tp_session_create(int priv_size,
	212	struct l2tp_tunnel *tunnel,
	213	u32 session_id, u32 peer_session_id,
	214	struct l2tp_session_cfg *cfg);
3953ae7b GN	215	int l2tp_session_register(struct l2tp_session *session,
	216	struct l2tp_tunnel *tunnel);
	217
c1b1203d JP	218	void __l2tp_session_unhash(struct l2tp_session *session);
	219	int l2tp_session_delete(struct l2tp_session *session);
	220	void l2tp_session_free(struct l2tp_session *session);
	221	void l2tp_recv_common(struct l2tp_session session, struct sk_buff skb,
	222	unsigned char ptr, unsigned char optr, u16 hdrflags,
2b139e6b	223	int length);
c1b1203d	224	int l2tp_udp_encap_recv(struct sock sk, struct sk_buff skb);
bb5016ea	225	void l2tp_session_set_header_len(struct l2tp_session *session, int version);
c1b1203d JP	226
	227	int l2tp_xmit_skb(struct l2tp_session session, struct sk_buff skb,
	228	int hdr_len);
	229
	230	int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
	231	const struct l2tp_nl_cmd_ops *ops);
	232	void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
72fb96e7	233	int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
309795f4	234
54652eb1 GN	235	static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
	236	{
	237	refcount_inc(&tunnel->ref_count);
	238	}
	239
	240	static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
	241	{
	242	if (refcount_dec_and_test(&tunnel->ref_count))
d00fa9ad	243	l2tp_tunnel_free(tunnel);
54652eb1 GN	244	}
54652eb1 GN	245
fd558d18 JC	246	/* Session reference counts. Incremented when code obtains a reference
	247	* to a session.
	248	*/
9ff672ba	249	static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
fd558d18	250	{
f00c854c	251	refcount_inc(&session->ref_count);
fd558d18 JC	252	}
fd558d18 JC	253
9ff672ba	254	static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
fd558d18	255	{
f00c854c	256	if (refcount_dec_and_test(&session->ref_count))
fd558d18 JC	257	l2tp_session_free(session);
	258	}
	259
62e7b6a5 LB	260	static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
	261	{
	262	switch (session->l2specific_type) {
	263	case L2TP_L2SPECTYPE_DEFAULT:
	264	return 4;
	265	case L2TP_L2SPECTYPE_NONE:
	266	default:
	267	return 0;
	268	}
	269	}
	270
1f5cd2a0 GN	271	static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
	272	{
	273	struct dst_entry *dst;
	274	u32 mtu;
	275
	276	dst = sk_dst_get(tunnel->sock);
	277	if (!dst)
	278	return 0;
	279
	280	mtu = dst_mtu(dst);
	281	dst_release(dst);
	282
	283	return mtu;
	284	}
	285
d6a61ec9 GN	286	#ifdef CONFIG_XFRM
	287	static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
	288	{
	289	struct sock *sk = tunnel->sock;
	290
	291	return sk && (rcu_access_pointer(sk->sk_policy[0]) \|\|
	292	rcu_access_pointer(sk->sk_policy[1]));
	293	}
	294	#else
	295	static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
	296	{
	297	return false;
	298	}
	299	#endif
	300
4522a70d JW	301	static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session session, struct sk_buff skb,
	302	unsigned char ptr, unsigned char optr)
	303	{
	304	int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
	305
	306	if (opt_len > 0) {
	307	int off = ptr - optr;
	308
	309	if (!pskb_may_pull(skb, off + opt_len))
	310	return -1;
	311
	312	if (skb->data != *optr) {
	313	*optr = skb->data;
	314	*ptr = skb->data + off;
	315	}
	316	}
	317
	318	return 0;
	319	}
	320
a4ca44fa JP	321	#define l2tp_printk(ptr, type, func, fmt, ...) \
	322	do { \
	323	if (((ptr)->debug) & (type)) \
	324	func(fmt, ##__VA_ARGS__); \
	325	} while (0)
	326
	327	#define l2tp_warn(ptr, type, fmt, ...) \
	328	l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
	329	#define l2tp_info(ptr, type, fmt, ...) \
	330	l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
	331	#define l2tp_dbg(ptr, type, fmt, ...) \
	332	l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
	333
f1f39f91	334	#define MODULE_ALIAS_L2TP_PWTYPE(type) \
	335	MODULE_ALIAS("net-l2tp-type-" __stringify(type))
	336
fd558d18	337	#endif /* _L2TP_CORE_H_ */