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)
26 /* Debug message categories for the DEBUG socket option */
28 L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if
30 L2TP_MSG_CONTROL = (1 << 1), /* userspace - kernel
32 L2TP_MSG_SEQ = (1 << 2), /* sequence numbers */
33 L2TP_MSG_DATA = (1 << 3), /* data packets */
47 u64 rx_cookie_discards;
52 /* Describes a session. Contains information to determine incoming
53 * packets and transmit outgoing ones.
55 struct l2tp_session_cfg {
56 enum l2tp_pwtype pw_type;
57 unsigned data_seq:2; /* data sequencing level
58 * 0 => none, 1 => IP only,
61 unsigned recv_seq:1; /* expect receive packets with
62 * sequence numbers? */
63 unsigned send_seq:1; /* send packets with sequence
65 unsigned lns_mode:1; /* behave as LNS? LAC enables
66 * sequence numbers under
68 int debug; /* bitmask of debug message
70 u16 vlan_id; /* VLAN pseudowire only */
71 u16 offset; /* offset to payload */
72 u16 l2specific_len; /* Layer 2 specific length */
73 u16 l2specific_type; /* Layer 2 specific type */
74 u8 cookie[8]; /* optional cookie */
75 int cookie_len; /* 0, 4 or 8 bytes */
76 u8 peer_cookie[8]; /* peer's cookie */
77 int peer_cookie_len; /* 0, 4 or 8 bytes */
78 int reorder_timeout; /* configured reorder timeout
86 int magic; /* should be
87 * L2TP_SESSION_MAGIC */
89 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
97 u16 offset; /* offset from end of L2TP header
98 to beginning of data */
102 u32 nr; /* session NR state (receive) */
103 u32 ns; /* session NR state (send) */
104 struct sk_buff_head reorder_q; /* receive reorder queue */
105 struct hlist_node hlist; /* Hash list node */
108 char name[32]; /* for logging */
109 char ifname[IFNAMSIZ];
110 unsigned data_seq:2; /* data sequencing level
111 * 0 => none, 1 => IP only,
114 unsigned recv_seq:1; /* expect receive packets with
115 * sequence numbers? */
116 unsigned send_seq:1; /* send packets with sequence
118 unsigned lns_mode:1; /* behave as LNS? LAC enables
119 * sequence numbers under
121 int debug; /* bitmask of debug message
123 int reorder_timeout; /* configured reorder timeout
127 enum l2tp_pwtype pwtype;
128 struct l2tp_stats stats;
129 struct hlist_node global_hlist; /* Global hash list node */
131 int (*build_header)(struct l2tp_session *session, void *buf);
132 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
133 void (*session_close)(struct l2tp_session *session);
134 void (*ref)(struct l2tp_session *session);
135 void (*deref)(struct l2tp_session *session);
136 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
137 void (*show)(struct seq_file *m, void *priv);
139 uint8_t priv[0]; /* private data */
142 /* Describes the tunnel. It contains info to track all the associated
143 * sessions so incoming packets can be sorted out
145 struct l2tp_tunnel_cfg {
146 int debug; /* bitmask of debug message
148 enum l2tp_encap_type encap;
150 /* Used only for kernel-created sockets */
151 struct in_addr local_ip;
152 struct in_addr peer_ip;
155 unsigned int use_udp_checksums:1;
159 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 */
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 */
191 uint8_t priv[0]; /* private data */
194 struct l2tp_nl_cmd_ops {
195 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
196 u32 session_id, u32 peer_session_id,
197 struct l2tp_session_cfg *cfg);
198 int (*session_delete)(struct l2tp_session *session);
201 static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
203 return &tunnel->priv[0];
206 static inline void *l2tp_session_priv(struct l2tp_session *session)
208 return &session->priv[0];
211 static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
213 struct l2tp_tunnel *tunnel;
219 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
220 if (tunnel == NULL) {
225 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
231 struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
232 void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
234 struct l2tp_session *l2tp_session_get(const struct net *net,
235 struct l2tp_tunnel *tunnel,
236 u32 session_id, bool do_ref);
237 extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
238 struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
240 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
243 extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
244 extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
246 extern 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);
247 extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
248 extern 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);
249 int l2tp_session_register(struct l2tp_session *session,
250 struct l2tp_tunnel *tunnel);
251 extern int l2tp_session_delete(struct l2tp_session *session);
252 extern void l2tp_session_free(struct l2tp_session *session);
253 extern void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, unsigned char *ptr, unsigned char *optr, u16 hdrflags, int length, int (*payload_hook)(struct sk_buff *skb));
254 extern int l2tp_session_queue_purge(struct l2tp_session *session);
255 extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
257 extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
259 extern int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
260 extern void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
261 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
263 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
265 atomic_inc(&tunnel->ref_count);
268 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
270 if (atomic_dec_and_test(&tunnel->ref_count))
271 l2tp_tunnel_free(tunnel);
274 /* Session reference counts. Incremented when code obtains a reference
277 static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
279 atomic_inc(&session->ref_count);
282 static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
284 if (atomic_dec_and_test(&session->ref_count))
285 l2tp_session_free(session);
288 #ifdef L2TP_REFCNT_DEBUG
289 #define l2tp_session_inc_refcount(_s) do { \
290 printk(KERN_DEBUG "l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \
291 l2tp_session_inc_refcount_1(_s); \
293 #define l2tp_session_dec_refcount(_s) do { \
294 printk(KERN_DEBUG "l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \
295 l2tp_session_dec_refcount_1(_s); \
298 #define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
299 #define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
302 #endif /* _L2TP_CORE_H_ */