2 * L2TP internal definitions.
4 * Copyright (c) 2008,2009 Katalix Systems Ltd
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.
10 #include <linux/refcount.h>
15 /* Just some random numbers */
16 #define L2TP_TUNNEL_MAGIC 0x42114DDA
17 #define L2TP_SESSION_MAGIC 0x0C04EB7D
19 /* Per tunnel, session hash table size */
20 #define L2TP_HASH_BITS 4
21 #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
23 /* System-wide, session hash table size */
24 #define L2TP_HASH_BITS_2 8
25 #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
30 atomic_long_t tx_packets
;
31 atomic_long_t tx_bytes
;
32 atomic_long_t tx_errors
;
33 atomic_long_t rx_packets
;
34 atomic_long_t rx_bytes
;
35 atomic_long_t rx_seq_discards
;
36 atomic_long_t rx_oos_packets
;
37 atomic_long_t rx_errors
;
38 atomic_long_t rx_cookie_discards
;
43 /* Describes a session. Contains information to determine incoming
44 * packets and transmit outgoing ones.
46 struct l2tp_session_cfg
{
47 enum l2tp_pwtype pw_type
;
48 unsigned int data_seq
:2; /* data sequencing level
49 * 0 => none, 1 => IP only,
52 unsigned int recv_seq
:1; /* expect receive packets with
53 * sequence numbers? */
54 unsigned int send_seq
:1; /* send packets with sequence
56 unsigned int lns_mode
:1; /* behave as LNS? LAC enables
57 * sequence numbers under
59 int debug
; /* bitmask of debug message
61 u16 vlan_id
; /* VLAN pseudowire only */
62 u16 offset
; /* offset to payload */
63 u16 l2specific_len
; /* Layer 2 specific length */
64 u16 l2specific_type
; /* Layer 2 specific type */
65 u8 cookie
[8]; /* optional cookie */
66 int cookie_len
; /* 0, 4 or 8 bytes */
67 u8 peer_cookie
[8]; /* peer's cookie */
68 int peer_cookie_len
; /* 0, 4 or 8 bytes */
69 int reorder_timeout
; /* configured reorder timeout
77 int magic
; /* should be
78 * L2TP_SESSION_MAGIC */
80 struct l2tp_tunnel
*tunnel
; /* back pointer to tunnel
88 u16 offset
; /* offset from end of L2TP header
89 to beginning of data */
93 u32 nr
; /* session NR state (receive) */
94 u32 ns
; /* session NR state (send) */
95 struct sk_buff_head reorder_q
; /* receive reorder queue */
96 u32 nr_max
; /* max NR. Depends on tunnel */
97 u32 nr_window_size
; /* NR window size */
98 u32 nr_oos
; /* NR of last OOS packet */
99 int nr_oos_count
; /* For OOS recovery */
100 int nr_oos_count_max
;
101 struct hlist_node hlist
; /* Hash list node */
102 refcount_t ref_count
;
104 char name
[32]; /* for logging */
105 char ifname
[IFNAMSIZ
];
106 unsigned int data_seq
:2; /* data sequencing level
107 * 0 => none, 1 => IP only,
110 unsigned int recv_seq
:1; /* expect receive packets with
111 * sequence numbers? */
112 unsigned int send_seq
:1; /* send packets with sequence
114 unsigned int lns_mode
:1; /* behave as LNS? LAC enables
115 * sequence numbers under
117 int debug
; /* bitmask of debug message
119 int reorder_timeout
; /* configured reorder timeout
121 int reorder_skip
; /* set if skip to next nr */
124 enum l2tp_pwtype pwtype
;
125 struct l2tp_stats stats
;
126 struct hlist_node global_hlist
; /* Global hash list node */
128 int (*build_header
)(struct l2tp_session
*session
, void *buf
);
129 void (*recv_skb
)(struct l2tp_session
*session
, struct sk_buff
*skb
, int data_len
);
130 void (*session_close
)(struct l2tp_session
*session
);
131 void (*ref
)(struct l2tp_session
*session
);
132 void (*deref
)(struct l2tp_session
*session
);
133 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
134 void (*show
)(struct seq_file
*m
, void *priv
);
136 uint8_t priv
[0]; /* private data */
139 /* Describes the tunnel. It contains info to track all the associated
140 * sessions so incoming packets can be sorted out
142 struct l2tp_tunnel_cfg
{
143 int debug
; /* bitmask of debug message
145 enum l2tp_encap_type encap
;
147 /* Used only for kernel-created sockets */
148 struct in_addr local_ip
;
149 struct in_addr peer_ip
;
150 #if IS_ENABLED(CONFIG_IPV6)
151 struct in6_addr
*local_ip6
;
152 struct in6_addr
*peer_ip6
;
156 unsigned int use_udp_checksums
:1,
157 udp6_zero_tx_checksums
:1,
158 udp6_zero_rx_checksums
:1;
162 int magic
; /* Should be L2TP_TUNNEL_MAGIC */
164 rwlock_t hlist_lock
; /* protect session_hlist */
165 bool acpt_newsess
; /* Indicates whether this
166 * tunnel accepts new sessions.
167 * Protected by hlist_lock.
169 struct hlist_head session_hlist
[L2TP_HASH_SIZE
];
170 /* hashed list of sessions,
174 int version
; /* 2=>L2TPv2, 3=>L2TPv3 */
176 char name
[20]; /* for logging */
177 int debug
; /* bitmask of debug message
179 enum l2tp_encap_type encap
;
180 struct l2tp_stats stats
;
182 struct list_head list
; /* Keep a list of all tunnels */
183 struct net
*l2tp_net
; /* the net we belong to */
185 refcount_t ref_count
;
186 #ifdef CONFIG_DEBUG_FS
187 void (*show
)(struct seq_file
*m
, void *arg
);
189 int (*recv_payload_hook
)(struct sk_buff
*skb
);
190 void (*old_sk_destruct
)(struct sock
*);
191 struct sock
*sock
; /* Parent socket */
192 int fd
; /* Parent fd, if tunnel socket
193 * was created by userspace */
194 #if IS_ENABLED(CONFIG_IPV6)
198 struct work_struct del_work
;
200 uint8_t priv
[0]; /* private data */
203 struct l2tp_nl_cmd_ops
{
204 int (*session_create
)(struct net
*net
, u32 tunnel_id
, u32 session_id
, u32 peer_session_id
, struct l2tp_session_cfg
*cfg
);
205 int (*session_delete
)(struct l2tp_session
*session
);
208 static inline void *l2tp_tunnel_priv(struct l2tp_tunnel
*tunnel
)
210 return &tunnel
->priv
[0];
213 static inline void *l2tp_session_priv(struct l2tp_session
*session
)
215 return &session
->priv
[0];
218 static inline struct l2tp_tunnel
*l2tp_sock_to_tunnel(struct sock
*sk
)
220 struct l2tp_tunnel
*tunnel
;
226 tunnel
= (struct l2tp_tunnel
*)(sk
->sk_user_data
);
227 if (tunnel
== NULL
) {
232 BUG_ON(tunnel
->magic
!= L2TP_TUNNEL_MAGIC
);
238 struct l2tp_tunnel
*l2tp_tunnel_get(const struct net
*net
, u32 tunnel_id
);
240 struct l2tp_session
*l2tp_session_get(const struct net
*net
,
241 struct l2tp_tunnel
*tunnel
,
242 u32 session_id
, bool do_ref
);
243 struct l2tp_session
*l2tp_session_get_nth(struct l2tp_tunnel
*tunnel
, int nth
,
245 struct l2tp_session
*l2tp_session_get_by_ifname(const struct net
*net
,
248 struct l2tp_tunnel
*l2tp_tunnel_find(const struct net
*net
, u32 tunnel_id
);
249 struct l2tp_tunnel
*l2tp_tunnel_find_nth(const struct net
*net
, int nth
);
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 void l2tp_session_set_header_len(struct l2tp_session
*session
, int version
);
270 int l2tp_xmit_skb(struct l2tp_session
*session
, struct sk_buff
*skb
,
273 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type
,
274 const struct l2tp_nl_cmd_ops
*ops
);
275 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type
);
276 int l2tp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
);
278 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel
*tunnel
)
280 refcount_inc(&tunnel
->ref_count
);
283 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel
*tunnel
)
285 if (refcount_dec_and_test(&tunnel
->ref_count
))
286 kfree_rcu(tunnel
, rcu
);
289 /* Session reference counts. Incremented when code obtains a reference
292 static inline void l2tp_session_inc_refcount_1(struct l2tp_session
*session
)
294 refcount_inc(&session
->ref_count
);
297 static inline void l2tp_session_dec_refcount_1(struct l2tp_session
*session
)
299 if (refcount_dec_and_test(&session
->ref_count
))
300 l2tp_session_free(session
);
303 #ifdef L2TP_REFCNT_DEBUG
304 #define l2tp_session_inc_refcount(_s) \
306 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
307 __func__, __LINE__, (_s)->name, \
308 refcount_read(&_s->ref_count)); \
309 l2tp_session_inc_refcount_1(_s); \
311 #define l2tp_session_dec_refcount(_s) \
313 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
314 __func__, __LINE__, (_s)->name, \
315 refcount_read(&_s->ref_count)); \
316 l2tp_session_dec_refcount_1(_s); \
319 #define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
320 #define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
323 #define l2tp_printk(ptr, type, func, fmt, ...) \
325 if (((ptr)->debug) & (type)) \
326 func(fmt, ##__VA_ARGS__); \
329 #define l2tp_warn(ptr, type, fmt, ...) \
330 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
331 #define l2tp_info(ptr, type, fmt, ...) \
332 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
333 #define l2tp_dbg(ptr, type, fmt, ...) \
334 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
336 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
337 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
339 #endif /* _L2TP_CORE_H_ */