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.
14 /* Just some random numbers */
15 #define L2TP_TUNNEL_MAGIC 0x42114DDA
16 #define L2TP_SESSION_MAGIC 0x0C04EB7D
18 /* Per tunnel, session hash table size */
19 #define L2TP_HASH_BITS 4
20 #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
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)
29 atomic_long_t tx_packets;
30 atomic_long_t tx_bytes;
31 atomic_long_t tx_errors;
32 atomic_long_t rx_packets;
33 atomic_long_t rx_bytes;
34 atomic_long_t rx_seq_discards;
35 atomic_long_t rx_oos_packets;
36 atomic_long_t rx_errors;
37 atomic_long_t rx_cookie_discards;
42 /* Describes a session. Contains information to determine incoming
43 * packets and transmit outgoing ones.
45 struct l2tp_session_cfg {
46 enum l2tp_pwtype pw_type;
47 unsigned int data_seq:2; /* data sequencing level
48 * 0 => none, 1 => IP only,
51 unsigned int recv_seq:1; /* expect receive packets with
52 * sequence numbers? */
53 unsigned int send_seq:1; /* send packets with sequence
55 unsigned int lns_mode:1; /* behave as LNS? LAC enables
56 * sequence numbers under
58 int debug; /* bitmask of debug message
60 u16 vlan_id; /* VLAN pseudowire only */
61 u16 l2specific_len; /* Layer 2 specific length */
62 u16 l2specific_type; /* Layer 2 specific type */
63 u8 cookie[8]; /* optional cookie */
64 int cookie_len; /* 0, 4 or 8 bytes */
65 u8 peer_cookie[8]; /* peer's cookie */
66 int peer_cookie_len; /* 0, 4 or 8 bytes */
67 int reorder_timeout; /* configured reorder timeout
75 int magic; /* should be
76 * L2TP_SESSION_MAGIC */
79 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
90 u32 nr; /* session NR state (receive) */
91 u32 ns; /* session NR state (send) */
92 struct sk_buff_head reorder_q; /* receive reorder queue */
93 u32 nr_max; /* max NR. Depends on tunnel */
94 u32 nr_window_size; /* NR window size */
95 u32 nr_oos; /* NR of last OOS packet */
96 int nr_oos_count; /* For OOS recovery */
98 struct hlist_node hlist; /* Hash list node */
101 char name[32]; /* for logging */
102 char ifname[IFNAMSIZ];
103 unsigned int data_seq:2; /* data sequencing level
104 * 0 => none, 1 => IP only,
107 unsigned int recv_seq:1; /* expect receive packets with
108 * sequence numbers? */
109 unsigned int send_seq:1; /* send packets with sequence
111 unsigned int lns_mode:1; /* behave as LNS? LAC enables
112 * sequence numbers under
114 int debug; /* bitmask of debug message
116 int reorder_timeout; /* configured reorder timeout
118 int reorder_skip; /* set if skip to next nr */
121 enum l2tp_pwtype pwtype;
122 struct l2tp_stats stats;
123 struct hlist_node global_hlist; /* Global hash list node */
125 int (*build_header)(struct l2tp_session *session, void *buf);
126 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
127 void (*session_close)(struct l2tp_session *session);
128 void (*ref)(struct l2tp_session *session);
129 void (*deref)(struct l2tp_session *session);
130 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
131 void (*show)(struct seq_file *m, void *priv);
133 uint8_t priv[0]; /* private data */
136 /* Describes the tunnel. It contains info to track all the associated
137 * sessions so incoming packets can be sorted out
139 struct l2tp_tunnel_cfg {
140 int debug; /* bitmask of debug message
142 enum l2tp_encap_type encap;
144 /* Used only for kernel-created sockets */
145 struct in_addr local_ip;
146 struct in_addr peer_ip;
147 #if IS_ENABLED(CONFIG_IPV6)
148 struct in6_addr *local_ip6;
149 struct in6_addr *peer_ip6;
153 unsigned int use_udp_checksums:1,
154 udp6_zero_tx_checksums:1,
155 udp6_zero_rx_checksums:1;
159 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 */
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 */
195 struct work_struct del_work;
197 uint8_t priv[0]; /* private data */
200 struct l2tp_nl_cmd_ops {
201 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
202 u32 session_id, u32 peer_session_id,
203 struct l2tp_session_cfg *cfg);
204 int (*session_delete)(struct l2tp_session *session);
207 static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
209 return &tunnel->priv[0];
212 static inline void *l2tp_session_priv(struct l2tp_session *session)
214 return &session->priv[0];
217 static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
219 struct l2tp_tunnel *tunnel;
225 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
226 if (tunnel == NULL) {
231 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
237 struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
239 struct l2tp_session *l2tp_session_get(const struct net *net,
240 struct l2tp_tunnel *tunnel,
241 u32 session_id, bool do_ref);
242 struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
244 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
247 struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id);
248 struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth);
250 int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
251 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
252 struct l2tp_tunnel **tunnelp);
253 void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
254 void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
255 struct l2tp_session *l2tp_session_create(int priv_size,
256 struct l2tp_tunnel *tunnel,
257 u32 session_id, u32 peer_session_id,
258 struct l2tp_session_cfg *cfg);
259 int l2tp_session_register(struct l2tp_session *session,
260 struct l2tp_tunnel *tunnel);
262 void __l2tp_session_unhash(struct l2tp_session *session);
263 int l2tp_session_delete(struct l2tp_session *session);
264 void l2tp_session_free(struct l2tp_session *session);
265 void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
266 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
267 int length, int (*payload_hook)(struct sk_buff *skb));
268 int l2tp_session_queue_purge(struct l2tp_session *session);
269 int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
270 void l2tp_session_set_header_len(struct l2tp_session *session, int version);
272 int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
275 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
276 const struct l2tp_nl_cmd_ops *ops);
277 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
278 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
280 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
282 atomic_inc(&tunnel->ref_count);
285 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
287 if (atomic_dec_and_test(&tunnel->ref_count))
288 kfree_rcu(tunnel, rcu);
291 /* Session reference counts. Incremented when code obtains a reference
294 static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
296 atomic_inc(&session->ref_count);
299 static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
301 if (atomic_dec_and_test(&session->ref_count))
302 l2tp_session_free(session);
305 #ifdef L2TP_REFCNT_DEBUG
306 #define l2tp_session_inc_refcount(_s) \
308 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
309 __func__, __LINE__, (_s)->name, \
310 atomic_read(&_s->ref_count)); \
311 l2tp_session_inc_refcount_1(_s); \
313 #define l2tp_session_dec_refcount(_s) \
315 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
316 __func__, __LINE__, (_s)->name, \
317 atomic_read(&_s->ref_count)); \
318 l2tp_session_dec_refcount_1(_s); \
321 #define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
322 #define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
325 static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
327 switch (session->l2specific_type) {
328 case L2TP_L2SPECTYPE_DEFAULT:
330 case L2TP_L2SPECTYPE_NONE:
336 static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
337 unsigned char **ptr, unsigned char **optr)
339 int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
342 int off = *ptr - *optr;
344 if (!pskb_may_pull(skb, off + opt_len))
347 if (skb->data != *optr) {
349 *ptr = skb->data + off;
356 #define l2tp_printk(ptr, type, func, fmt, ...) \
358 if (((ptr)->debug) & (type)) \
359 func(fmt, ##__VA_ARGS__); \
362 #define l2tp_warn(ptr, type, fmt, ...) \
363 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
364 #define l2tp_info(ptr, type, fmt, ...) \
365 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
366 #define l2tp_dbg(ptr, type, fmt, ...) \
367 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
369 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
370 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
372 #endif /* _L2TP_CORE_H_ */