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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 {
Tom Parkin7b7c0712013-03-19 06:11:22 +000039 atomic_long_t tx_packets;
40 atomic_long_t tx_bytes;
41 atomic_long_t tx_errors;
42 atomic_long_t rx_packets;
43 atomic_long_t rx_bytes;
44 atomic_long_t rx_seq_discards;
45 atomic_long_t rx_oos_packets;
46 atomic_long_t rx_errors;
47 atomic_long_t 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;
Eric Dumazet95c96172012-04-15 05:58:06 +000057 unsigned int data_seq:2; /* data sequencing level
James Chapmanfd558d12010-04-02 06:18:33 +000058 * 0 => none, 1 => IP only,
59 * 2 => all
60 */
Eric Dumazet95c96172012-04-15 05:58:06 +000061 unsigned int recv_seq:1; /* expect receive packets with
James Chapmanfd558d12010-04-02 06:18:33 +000062 * sequence numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +000063 unsigned int send_seq:1; /* send packets with sequence
James Chapmanfd558d12010-04-02 06:18:33 +000064 * numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +000065 unsigned int lns_mode:1; /* behave as LNS? LAC enables
James Chapmanfd558d12010-04-02 06:18:33 +000066 * 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];
Eric Dumazet95c96172012-04-15 05:58:06 +0000110 unsigned int data_seq:2; /* data sequencing level
James Chapmanfd558d12010-04-02 06:18:33 +0000111 * 0 => none, 1 => IP only,
112 * 2 => all
113 */
Eric Dumazet95c96172012-04-15 05:58:06 +0000114 unsigned int recv_seq:1; /* expect receive packets with
James Chapmanfd558d12010-04-02 06:18:33 +0000115 * sequence numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +0000116 unsigned int send_seq:1; /* send packets with sequence
James Chapmanfd558d12010-04-02 06:18:33 +0000117 * numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +0000118 unsigned int lns_mode:1; /* behave as LNS? LAC enables
James Chapmanfd558d12010-04-02 06:18:33 +0000119 * 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) */
James Chapman38d40b32012-05-09 23:43:08 +0000125 int reorder_skip; /* set if skip to next nr */
James Chapmanfd558d12010-04-02 06:18:33 +0000126 int mtu;
127 int mru;
James Chapmanf7faffa2010-04-02 06:18:49 +0000128 enum l2tp_pwtype pwtype;
James Chapmanfd558d12010-04-02 06:18:33 +0000129 struct l2tp_stats stats;
James Chapmanf7faffa2010-04-02 06:18:49 +0000130 struct hlist_node global_hlist; /* Global hash list node */
James Chapmanfd558d12010-04-02 06:18:33 +0000131
James Chapmanf7faffa2010-04-02 06:18:49 +0000132 int (*build_header)(struct l2tp_session *session, void *buf);
James Chapmanfd558d12010-04-02 06:18:33 +0000133 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
134 void (*session_close)(struct l2tp_session *session);
135 void (*ref)(struct l2tp_session *session);
136 void (*deref)(struct l2tp_session *session);
David S. Millerf66ef2d2010-04-03 15:01:37 -0700137#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
James Chapman0ad66142010-04-02 06:19:33 +0000138 void (*show)(struct seq_file *m, void *priv);
139#endif
James Chapmanfd558d12010-04-02 06:18:33 +0000140 uint8_t priv[0]; /* private data */
141};
142
143/* Describes the tunnel. It contains info to track all the associated
144 * sessions so incoming packets can be sorted out
145 */
146struct l2tp_tunnel_cfg {
147 int debug; /* bitmask of debug message
148 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000149 enum l2tp_encap_type encap;
James Chapman789a4a22010-04-02 06:19:40 +0000150
151 /* Used only for kernel-created sockets */
152 struct in_addr local_ip;
153 struct in_addr peer_ip;
Chris Elstonf9bac8d2012-04-29 21:48:52 +0000154#if IS_ENABLED(CONFIG_IPV6)
155 struct in6_addr *local_ip6;
156 struct in6_addr *peer_ip6;
157#endif
James Chapman789a4a22010-04-02 06:19:40 +0000158 u16 local_udp_port;
159 u16 peer_udp_port;
Eric Dumazet7bddd0d2010-04-04 01:02:46 -0700160 unsigned int use_udp_checksums:1;
James Chapmanfd558d12010-04-02 06:18:33 +0000161};
162
163struct l2tp_tunnel {
164 int magic; /* Should be L2TP_TUNNEL_MAGIC */
xeb@mail.ru99469c32012-08-24 01:07:38 +0000165 struct rcu_head rcu;
James Chapmanfd558d12010-04-02 06:18:33 +0000166 rwlock_t hlist_lock; /* protect session_hlist */
167 struct hlist_head session_hlist[L2TP_HASH_SIZE];
168 /* hashed list of sessions,
169 * hashed by id */
170 u32 tunnel_id;
171 u32 peer_tunnel_id;
172 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
173
174 char name[20]; /* for logging */
175 int debug; /* bitmask of debug message
176 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000177 enum l2tp_encap_type encap;
James Chapmanfd558d12010-04-02 06:18:33 +0000178 struct l2tp_stats stats;
179
180 struct list_head list; /* Keep a list of all tunnels */
181 struct net *l2tp_net; /* the net we belong to */
182
183 atomic_t ref_count;
James Chapman0ad66142010-04-02 06:19:33 +0000184#ifdef CONFIG_DEBUG_FS
185 void (*show)(struct seq_file *m, void *arg);
186#endif
James Chapmanfd558d12010-04-02 06:18:33 +0000187 int (*recv_payload_hook)(struct sk_buff *skb);
188 void (*old_sk_destruct)(struct sock *);
189 struct sock *sock; /* Parent socket */
Tom Parkin80d84ef2013-01-22 05:13:48 +0000190 int fd; /* Parent fd, if tunnel socket
191 * was created by userspace */
James Chapmanfd558d12010-04-02 06:18:33 +0000192
Tom Parkinf8ccac02013-01-31 23:43:00 +0000193 struct work_struct del_work;
194
James Chapmanfd558d12010-04-02 06:18:33 +0000195 uint8_t priv[0]; /* private data */
196};
197
James Chapman309795f2010-04-02 06:19:10 +0000198struct l2tp_nl_cmd_ops {
199 int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
200 int (*session_delete)(struct l2tp_session *session);
201};
202
James Chapmanfd558d12010-04-02 06:18:33 +0000203static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
204{
205 return &tunnel->priv[0];
206}
207
208static inline void *l2tp_session_priv(struct l2tp_session *session)
209{
210 return &session->priv[0];
211}
212
213static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
214{
215 struct l2tp_tunnel *tunnel;
216
217 if (sk == NULL)
218 return NULL;
219
220 sock_hold(sk);
221 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
222 if (tunnel == NULL) {
223 sock_put(sk);
224 goto out;
225 }
226
227 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
228
229out:
230 return tunnel;
231}
232
Tom Parkin80d84ef2013-01-22 05:13:48 +0000233extern struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel);
234extern void l2tp_tunnel_sock_put(struct sock *sk);
James Chapmanf7faffa2010-04-02 06:18:49 +0000235extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
James Chapmanfd558d12010-04-02 06:18:33 +0000236extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
James Chapman309795f2010-04-02 06:19:10 +0000237extern struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
James Chapmanfd558d12010-04-02 06:18:33 +0000238extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
239extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
240
241extern 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);
Tom Parkine34f4c72013-03-19 06:11:14 +0000242extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
James Chapman309795f2010-04-02 06:19:10 +0000243extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
James Chapmanfd558d12010-04-02 06:18:33 +0000244extern 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);
Tom Parkinf6e16b22013-03-19 06:11:23 +0000245extern void __l2tp_session_unhash(struct l2tp_session *session);
James Chapman309795f2010-04-02 06:19:10 +0000246extern int l2tp_session_delete(struct l2tp_session *session);
James Chapmanfd558d12010-04-02 06:18:33 +0000247extern void l2tp_session_free(struct l2tp_session *session);
James Chapmanf7faffa2010-04-02 06:18:49 +0000248extern 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));
Tom Parkin48f72f92013-03-19 06:11:19 +0000249extern int l2tp_session_queue_purge(struct l2tp_session *session);
James Chapmanfd558d12010-04-02 06:18:33 +0000250extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
251
James Chapmanfd558d12010-04-02 06:18:33 +0000252extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
James Chapmanfd558d12010-04-02 06:18:33 +0000253
James Chapman309795f2010-04-02 06:19:10 +0000254extern int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
255extern void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
256
James Chapmanfd558d12010-04-02 06:18:33 +0000257/* Session reference counts. Incremented when code obtains a reference
258 * to a session.
259 */
260static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
261{
262 atomic_inc(&session->ref_count);
263}
264
265static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
266{
267 if (atomic_dec_and_test(&session->ref_count))
268 l2tp_session_free(session);
269}
270
271#ifdef L2TP_REFCNT_DEBUG
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000272#define l2tp_session_inc_refcount(_s) \
273do { \
274 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
275 __func__, __LINE__, (_s)->name, \
276 atomic_read(&_s->ref_count)); \
277 l2tp_session_inc_refcount_1(_s); \
278} while (0)
279#define l2tp_session_dec_refcount(_s) \
280do { \
281 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
282 __func__, __LINE__, (_s)->name, \
283 atomic_read(&_s->ref_count)); \
284 l2tp_session_dec_refcount_1(_s); \
285} while (0)
James Chapmanfd558d12010-04-02 06:18:33 +0000286#else
287#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
288#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
289#endif
290
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000291#define l2tp_printk(ptr, type, func, fmt, ...) \
292do { \
293 if (((ptr)->debug) & (type)) \
294 func(fmt, ##__VA_ARGS__); \
295} while (0)
296
297#define l2tp_warn(ptr, type, fmt, ...) \
298 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
299#define l2tp_info(ptr, type, fmt, ...) \
300 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
301#define l2tp_dbg(ptr, type, fmt, ...) \
302 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
303
James Chapmanfd558d12010-04-02 06:18:33 +0000304#endif /* _L2TP_CORE_H_ */