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James Chapmanfd558d12010-04-02 06:18:33 +00001/*
2 * L2TP internal definitions.
3 *
4 * Copyright (c) 2008,2009 Katalix Systems Ltd
5 *
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.
9 */
10
11#ifndef _L2TP_CORE_H_
12#define _L2TP_CORE_H_
13
14/* Just some random numbers */
15#define L2TP_TUNNEL_MAGIC 0x42114DDA
16#define L2TP_SESSION_MAGIC 0x0C04EB7D
17
James Chapmanf7faffa2010-04-02 06:18:49 +000018/* Per tunnel, session hash table size */
James Chapmanfd558d12010-04-02 06:18:33 +000019#define L2TP_HASH_BITS 4
20#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
21
James Chapmanf7faffa2010-04-02 06:18:49 +000022/* System-wide, session hash table size */
23#define L2TP_HASH_BITS_2 8
24#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
25
James Chapmanfd558d12010-04-02 06:18:33 +000026/* Debug message categories for the DEBUG socket option */
27enum {
28 L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if
29 * compiled in) */
30 L2TP_MSG_CONTROL = (1 << 1), /* userspace - kernel
31 * interface */
32 L2TP_MSG_SEQ = (1 << 2), /* sequence numbers */
33 L2TP_MSG_DATA = (1 << 3), /* data packets */
34};
35
36struct sk_buff;
37
38struct l2tp_stats {
39 u64 tx_packets;
40 u64 tx_bytes;
41 u64 tx_errors;
42 u64 rx_packets;
43 u64 rx_bytes;
44 u64 rx_seq_discards;
45 u64 rx_oos_packets;
46 u64 rx_errors;
James Chapmanf7faffa2010-04-02 06:18:49 +000047 u64 rx_cookie_discards;
James Chapmanfd558d12010-04-02 06:18:33 +000048};
49
50struct l2tp_tunnel;
51
52/* Describes a session. Contains information to determine incoming
53 * packets and transmit outgoing ones.
54 */
55struct l2tp_session_cfg {
James Chapmanf7faffa2010-04-02 06:18:49 +000056 enum l2tp_pwtype pw_type;
James Chapmanfd558d12010-04-02 06:18:33 +000057 unsigned data_seq:2; /* data sequencing level
58 * 0 => none, 1 => IP only,
59 * 2 => all
60 */
61 unsigned recv_seq:1; /* expect receive packets with
62 * sequence numbers? */
63 unsigned send_seq:1; /* send packets with sequence
64 * numbers? */
65 unsigned lns_mode:1; /* behave as LNS? LAC enables
66 * sequence numbers under
67 * control of LNS. */
68 int debug; /* bitmask of debug message
69 * categories */
James Chapman309795f2010-04-02 06:19:10 +000070 u16 vlan_id; /* VLAN pseudowire only */
James Chapmanf7faffa2010-04-02 06:18:49 +000071 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 */
James Chapmanfd558d12010-04-02 06:18:33 +000078 int reorder_timeout; /* configured reorder timeout
79 * (in jiffies) */
80 int mtu;
81 int mru;
James Chapman309795f2010-04-02 06:19:10 +000082 char *ifname;
James Chapmanfd558d12010-04-02 06:18:33 +000083};
84
85struct l2tp_session {
86 int magic; /* should be
87 * L2TP_SESSION_MAGIC */
88
89 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
90 * context */
91 u32 session_id;
92 u32 peer_session_id;
James Chapmanf7faffa2010-04-02 06:18:49 +000093 u8 cookie[8];
94 int cookie_len;
95 u8 peer_cookie[8];
96 int peer_cookie_len;
97 u16 offset; /* offset from end of L2TP header
98 to beginning of data */
99 u16 l2specific_len;
100 u16 l2specific_type;
101 u16 hdr_len;
102 u32 nr; /* session NR state (receive) */
103 u32 ns; /* session NR state (send) */
James Chapmanfd558d12010-04-02 06:18:33 +0000104 struct sk_buff_head reorder_q; /* receive reorder queue */
105 struct hlist_node hlist; /* Hash list node */
106 atomic_t ref_count;
107
108 char name[32]; /* for logging */
James Chapman309795f2010-04-02 06:19:10 +0000109 char ifname[IFNAMSIZ];
James Chapmanfd558d12010-04-02 06:18:33 +0000110 unsigned data_seq:2; /* data sequencing level
111 * 0 => none, 1 => IP only,
112 * 2 => all
113 */
114 unsigned recv_seq:1; /* expect receive packets with
115 * sequence numbers? */
116 unsigned send_seq:1; /* send packets with sequence
117 * numbers? */
118 unsigned lns_mode:1; /* behave as LNS? LAC enables
119 * sequence numbers under
120 * control of LNS. */
121 int debug; /* bitmask of debug message
122 * categories */
123 int reorder_timeout; /* configured reorder timeout
124 * (in jiffies) */
125 int mtu;
126 int mru;
James Chapmanf7faffa2010-04-02 06:18:49 +0000127 enum l2tp_pwtype pwtype;
James Chapmanfd558d12010-04-02 06:18:33 +0000128 struct l2tp_stats stats;
James Chapmanf7faffa2010-04-02 06:18:49 +0000129 struct hlist_node global_hlist; /* Global hash list node */
James Chapmanfd558d12010-04-02 06:18:33 +0000130
James Chapmanf7faffa2010-04-02 06:18:49 +0000131 int (*build_header)(struct l2tp_session *session, void *buf);
James Chapmanfd558d12010-04-02 06:18:33 +0000132 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
137 uint8_t priv[0]; /* private data */
138};
139
140/* Describes the tunnel. It contains info to track all the associated
141 * sessions so incoming packets can be sorted out
142 */
143struct l2tp_tunnel_cfg {
144 int debug; /* bitmask of debug message
145 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000146 enum l2tp_encap_type encap;
James Chapmanfd558d12010-04-02 06:18:33 +0000147};
148
149struct l2tp_tunnel {
150 int magic; /* Should be L2TP_TUNNEL_MAGIC */
151 rwlock_t hlist_lock; /* protect session_hlist */
152 struct hlist_head session_hlist[L2TP_HASH_SIZE];
153 /* hashed list of sessions,
154 * hashed by id */
155 u32 tunnel_id;
156 u32 peer_tunnel_id;
157 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
158
159 char name[20]; /* for logging */
160 int debug; /* bitmask of debug message
161 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000162 enum l2tp_encap_type encap;
James Chapmanfd558d12010-04-02 06:18:33 +0000163 struct l2tp_stats stats;
164
165 struct list_head list; /* Keep a list of all tunnels */
166 struct net *l2tp_net; /* the net we belong to */
167
168 atomic_t ref_count;
169
170 int (*recv_payload_hook)(struct sk_buff *skb);
171 void (*old_sk_destruct)(struct sock *);
172 struct sock *sock; /* Parent socket */
173 int fd;
174
175 uint8_t priv[0]; /* private data */
176};
177
James Chapman309795f2010-04-02 06:19:10 +0000178struct l2tp_nl_cmd_ops {
179 int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
180 int (*session_delete)(struct l2tp_session *session);
181};
182
James Chapmanfd558d12010-04-02 06:18:33 +0000183static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
184{
185 return &tunnel->priv[0];
186}
187
188static inline void *l2tp_session_priv(struct l2tp_session *session)
189{
190 return &session->priv[0];
191}
192
193static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
194{
195 struct l2tp_tunnel *tunnel;
196
197 if (sk == NULL)
198 return NULL;
199
200 sock_hold(sk);
201 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
202 if (tunnel == NULL) {
203 sock_put(sk);
204 goto out;
205 }
206
207 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
208
209out:
210 return tunnel;
211}
212
James Chapmanf7faffa2010-04-02 06:18:49 +0000213extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
James Chapmanfd558d12010-04-02 06:18:33 +0000214extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
James Chapman309795f2010-04-02 06:19:10 +0000215extern struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
James Chapmanfd558d12010-04-02 06:18:33 +0000216extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
217extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
218
219extern 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);
James Chapman309795f2010-04-02 06:19:10 +0000220extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
James Chapmanfd558d12010-04-02 06:18:33 +0000221extern 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);
James Chapman309795f2010-04-02 06:19:10 +0000222extern int l2tp_session_delete(struct l2tp_session *session);
James Chapmanfd558d12010-04-02 06:18:33 +0000223extern void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
224extern void l2tp_session_free(struct l2tp_session *session);
James Chapmanf7faffa2010-04-02 06:18:49 +0000225extern 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));
James Chapmanfd558d12010-04-02 06:18:33 +0000226extern int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, int (*payload_hook)(struct sk_buff *skb));
227extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
228
James Chapmanfd558d12010-04-02 06:18:33 +0000229extern int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t data_len);
230extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
231extern void l2tp_tunnel_destruct(struct sock *sk);
232extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
James Chapmanf7faffa2010-04-02 06:18:49 +0000233extern void l2tp_session_set_header_len(struct l2tp_session *session, int version);
James Chapmanfd558d12010-04-02 06:18:33 +0000234
James Chapman309795f2010-04-02 06:19:10 +0000235extern int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
236extern void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
237
James Chapmanfd558d12010-04-02 06:18:33 +0000238/* Tunnel reference counts. Incremented per session that is added to
239 * the tunnel.
240 */
241static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel)
242{
243 atomic_inc(&tunnel->ref_count);
244}
245
246static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel)
247{
248 if (atomic_dec_and_test(&tunnel->ref_count))
249 l2tp_tunnel_free(tunnel);
250}
251#ifdef L2TP_REFCNT_DEBUG
252#define l2tp_tunnel_inc_refcount(_t) do { \
253 printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \
254 l2tp_tunnel_inc_refcount_1(_t); \
255 } while (0)
256#define l2tp_tunnel_dec_refcount(_t) do { \
257 printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \
258 l2tp_tunnel_dec_refcount_1(_t); \
259 } while (0)
260#else
261#define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t)
262#define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t)
263#endif
264
265/* Session reference counts. Incremented when code obtains a reference
266 * to a session.
267 */
268static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
269{
270 atomic_inc(&session->ref_count);
271}
272
273static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
274{
275 if (atomic_dec_and_test(&session->ref_count))
276 l2tp_session_free(session);
277}
278
279#ifdef L2TP_REFCNT_DEBUG
280#define l2tp_session_inc_refcount(_s) do { \
281 printk(KERN_DEBUG "l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \
282 l2tp_session_inc_refcount_1(_s); \
283 } while (0)
284#define l2tp_session_dec_refcount(_s) do { \
285 printk(KERN_DEBUG "l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \
286 l2tp_session_dec_refcount_1(_s); \
287 } while (0)
288#else
289#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
290#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
291#endif
292
293#endif /* _L2TP_CORE_H_ */