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 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
89 u32 nr; /* session NR state (receive) */
90 u32 ns; /* session NR state (send) */
91 struct sk_buff_head reorder_q; /* receive reorder queue */
92 u32 nr_max; /* max NR. Depends on tunnel */
93 u32 nr_window_size; /* NR window size */
94 u32 nr_oos; /* NR of last OOS packet */
95 int nr_oos_count; /* For OOS recovery */
97 struct hlist_node hlist; /* Hash list node */
100 char name[32]; /* for logging */
101 char ifname[IFNAMSIZ];
102 unsigned int data_seq:2; /* data sequencing level
103 * 0 => none, 1 => IP only,
106 unsigned int recv_seq:1; /* expect receive packets with
107 * sequence numbers? */
108 unsigned int send_seq:1; /* send packets with sequence
110 unsigned int lns_mode:1; /* behave as LNS? LAC enables
111 * sequence numbers under
113 int debug; /* bitmask of debug message
115 int reorder_timeout; /* configured reorder timeout
117 int reorder_skip; /* set if skip to next nr */
120 enum l2tp_pwtype pwtype;
121 struct l2tp_stats stats;
122 struct hlist_node global_hlist; /* Global hash list node */
124 int (*build_header)(struct l2tp_session *session, void *buf);
125 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
126 void (*session_close)(struct l2tp_session *session);
127 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
128 void (*show)(struct seq_file *m, void *priv);
130 uint8_t priv[0]; /* private data */
133 /* Describes the tunnel. It contains info to track all the associated
134 * sessions so incoming packets can be sorted out
136 struct l2tp_tunnel_cfg {
137 int debug; /* bitmask of debug message
139 enum l2tp_encap_type encap;
141 /* Used only for kernel-created sockets */
142 struct in_addr local_ip;
143 struct in_addr peer_ip;
144 #if IS_ENABLED(CONFIG_IPV6)
145 struct in6_addr *local_ip6;
146 struct in6_addr *peer_ip6;
150 unsigned int use_udp_checksums:1,
151 udp6_zero_tx_checksums:1,
152 udp6_zero_rx_checksums:1;
156 int magic; /* Should be L2TP_TUNNEL_MAGIC */
161 rwlock_t hlist_lock; /* protect session_hlist */
162 bool acpt_newsess; /* Indicates whether this
163 * tunnel accepts new sessions.
164 * Protected by hlist_lock.
166 struct hlist_head session_hlist[L2TP_HASH_SIZE];
167 /* hashed list of sessions,
171 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
173 char name[20]; /* for logging */
174 int debug; /* bitmask of debug message
176 enum l2tp_encap_type encap;
177 struct l2tp_stats stats;
179 struct list_head list; /* Keep a list of all tunnels */
180 struct net *l2tp_net; /* the net we belong to */
182 refcount_t ref_count;
183 #ifdef CONFIG_DEBUG_FS
184 void (*show)(struct seq_file *m, void *arg);
186 int (*recv_payload_hook)(struct sk_buff *skb);
187 void (*old_sk_destruct)(struct sock *);
188 struct sock *sock; /* Parent socket */
189 int fd; /* Parent fd, if tunnel socket
190 * was created by userspace */
192 struct work_struct del_work;
194 uint8_t priv[0]; /* private data */
197 struct l2tp_nl_cmd_ops {
198 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
199 u32 session_id, u32 peer_session_id,
200 struct l2tp_session_cfg *cfg);
201 int (*session_delete)(struct l2tp_session *session);
204 static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
206 return &tunnel->priv[0];
209 static inline void *l2tp_session_priv(struct l2tp_session *session)
211 return &session->priv[0];
214 struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
215 void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
217 struct l2tp_session *l2tp_session_get(const struct net *net,
218 struct l2tp_tunnel *tunnel,
220 struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
221 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
223 struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth);
225 int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
226 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
227 struct l2tp_tunnel **tunnelp);
228 int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
229 struct l2tp_tunnel_cfg *cfg);
231 void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
232 void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
233 struct l2tp_session *l2tp_session_create(int priv_size,
234 struct l2tp_tunnel *tunnel,
235 u32 session_id, u32 peer_session_id,
236 struct l2tp_session_cfg *cfg);
237 int l2tp_session_register(struct l2tp_session *session,
238 struct l2tp_tunnel *tunnel);
240 void __l2tp_session_unhash(struct l2tp_session *session);
241 int l2tp_session_delete(struct l2tp_session *session);
242 void l2tp_session_free(struct l2tp_session *session);
243 void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
244 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
245 int length, int (*payload_hook)(struct sk_buff *skb));
246 int l2tp_session_queue_purge(struct l2tp_session *session);
247 int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
248 void l2tp_session_set_header_len(struct l2tp_session *session, int version);
250 int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
253 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
254 const struct l2tp_nl_cmd_ops *ops);
255 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
256 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
258 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
260 refcount_inc(&tunnel->ref_count);
263 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
265 if (refcount_dec_and_test(&tunnel->ref_count))
266 l2tp_tunnel_free(tunnel);
269 /* Session reference counts. Incremented when code obtains a reference
272 static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
274 refcount_inc(&session->ref_count);
277 static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
279 if (refcount_dec_and_test(&session->ref_count))
280 l2tp_session_free(session);
283 static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
285 switch (session->l2specific_type) {
286 case L2TP_L2SPECTYPE_DEFAULT:
288 case L2TP_L2SPECTYPE_NONE:
294 #define l2tp_printk(ptr, type, func, fmt, ...) \
296 if (((ptr)->debug) & (type)) \
297 func(fmt, ##__VA_ARGS__); \
300 #define l2tp_warn(ptr, type, fmt, ...) \
301 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
302 #define l2tp_info(ptr, type, fmt, ...) \
303 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
304 #define l2tp_dbg(ptr, type, fmt, ...) \
305 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
307 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
308 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
310 #endif /* _L2TP_CORE_H_ */