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 */
81 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
89 u16 offset; /* offset from end of L2TP header
90 to beginning of data */
94 u32 nr; /* session NR state (receive) */
95 u32 ns; /* session NR state (send) */
96 struct sk_buff_head reorder_q; /* receive reorder queue */
97 u32 nr_max; /* max NR. Depends on tunnel */
98 u32 nr_window_size; /* NR window size */
99 u32 nr_oos; /* NR of last OOS packet */
100 int nr_oos_count; /* For OOS recovery */
101 int nr_oos_count_max;
102 struct hlist_node hlist; /* Hash list node */
103 refcount_t ref_count;
105 char name[32]; /* for logging */
106 char ifname[IFNAMSIZ];
107 unsigned int data_seq:2; /* data sequencing level
108 * 0 => none, 1 => IP only,
111 unsigned int recv_seq:1; /* expect receive packets with
112 * sequence numbers? */
113 unsigned int send_seq:1; /* send packets with sequence
115 unsigned int lns_mode:1; /* behave as LNS? LAC enables
116 * sequence numbers under
118 int debug; /* bitmask of debug message
120 int reorder_timeout; /* configured reorder timeout
122 int reorder_skip; /* set if skip to next nr */
125 enum l2tp_pwtype pwtype;
126 struct l2tp_stats stats;
127 struct hlist_node global_hlist; /* Global hash list node */
129 int (*build_header)(struct l2tp_session *session, void *buf);
130 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
131 void (*session_close)(struct l2tp_session *session);
132 void (*ref)(struct l2tp_session *session);
133 void (*deref)(struct l2tp_session *session);
134 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
135 void (*show)(struct seq_file *m, void *priv);
137 uint8_t priv[0]; /* private data */
140 /* Describes the tunnel. It contains info to track all the associated
141 * sessions so incoming packets can be sorted out
143 struct l2tp_tunnel_cfg {
144 int debug; /* bitmask of debug message
146 enum l2tp_encap_type encap;
148 /* Used only for kernel-created sockets */
149 struct in_addr local_ip;
150 struct in_addr peer_ip;
151 #if IS_ENABLED(CONFIG_IPV6)
152 struct in6_addr *local_ip6;
153 struct in6_addr *peer_ip6;
157 unsigned int use_udp_checksums:1,
158 udp6_zero_tx_checksums:1,
159 udp6_zero_rx_checksums:1;
163 int magic; /* Should be L2TP_TUNNEL_MAGIC */
168 rwlock_t hlist_lock; /* protect session_hlist */
169 bool acpt_newsess; /* Indicates whether this
170 * tunnel accepts new sessions.
171 * Protected by hlist_lock.
173 struct hlist_head session_hlist[L2TP_HASH_SIZE];
174 /* hashed list of sessions,
178 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
180 char name[20]; /* for logging */
181 int debug; /* bitmask of debug message
183 enum l2tp_encap_type encap;
184 struct l2tp_stats stats;
186 struct list_head list; /* Keep a list of all tunnels */
187 struct net *l2tp_net; /* the net we belong to */
189 refcount_t ref_count;
190 #ifdef CONFIG_DEBUG_FS
191 void (*show)(struct seq_file *m, void *arg);
193 int (*recv_payload_hook)(struct sk_buff *skb);
194 void (*old_sk_destruct)(struct sock *);
195 struct sock *sock; /* Parent socket */
196 int fd; /* Parent fd, if tunnel socket
197 * was created by userspace */
198 #if IS_ENABLED(CONFIG_IPV6)
202 struct work_struct del_work;
204 uint8_t priv[0]; /* private data */
207 struct l2tp_nl_cmd_ops {
208 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
209 u32 session_id, u32 peer_session_id,
210 struct l2tp_session_cfg *cfg);
211 int (*session_delete)(struct l2tp_session *session);
214 static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
216 return &tunnel->priv[0];
219 static inline void *l2tp_session_priv(struct l2tp_session *session)
221 return &session->priv[0];
224 static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
226 struct l2tp_tunnel *tunnel;
232 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
233 if (tunnel == NULL) {
238 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
244 struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
246 struct l2tp_session *l2tp_session_get(const struct net *net,
247 struct l2tp_tunnel *tunnel,
248 u32 session_id, bool do_ref);
249 struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
251 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
254 struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id);
255 struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth);
257 int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
258 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
259 struct l2tp_tunnel **tunnelp);
260 void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
261 void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
262 struct l2tp_session *l2tp_session_create(int priv_size,
263 struct l2tp_tunnel *tunnel,
264 u32 session_id, u32 peer_session_id,
265 struct l2tp_session_cfg *cfg);
266 void __l2tp_session_unhash(struct l2tp_session *session);
267 int l2tp_session_delete(struct l2tp_session *session);
268 void l2tp_session_free(struct l2tp_session *session);
269 void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
270 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
271 int length, int (*payload_hook)(struct sk_buff *skb));
272 int l2tp_session_queue_purge(struct l2tp_session *session);
273 int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
274 void l2tp_session_set_header_len(struct l2tp_session *session, int version);
276 int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
279 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
280 const struct l2tp_nl_cmd_ops *ops);
281 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
282 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
284 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
286 refcount_inc(&tunnel->ref_count);
289 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
291 if (refcount_dec_and_test(&tunnel->ref_count))
292 kfree_rcu(tunnel, rcu);
295 /* Session reference counts. Incremented when code obtains a reference
298 static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
300 refcount_inc(&session->ref_count);
303 static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
305 if (refcount_dec_and_test(&session->ref_count))
306 l2tp_session_free(session);
309 #ifdef L2TP_REFCNT_DEBUG
310 #define l2tp_session_inc_refcount(_s) \
312 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
313 __func__, __LINE__, (_s)->name, \
314 refcount_read(&_s->ref_count)); \
315 l2tp_session_inc_refcount_1(_s); \
317 #define l2tp_session_dec_refcount(_s) \
319 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
320 __func__, __LINE__, (_s)->name, \
321 refcount_read(&_s->ref_count)); \
322 l2tp_session_dec_refcount_1(_s); \
325 #define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
326 #define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
329 #define l2tp_printk(ptr, type, func, fmt, ...) \
331 if (((ptr)->debug) & (type)) \
332 func(fmt, ##__VA_ARGS__); \
335 #define l2tp_warn(ptr, type, fmt, ...) \
336 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
337 #define l2tp_info(ptr, type, fmt, ...) \
338 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
339 #define l2tp_dbg(ptr, type, fmt, ...) \
340 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
342 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
343 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
345 #endif /* _L2TP_CORE_H_ */