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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 */
James Chapman8a1631d2013-07-02 20:28:59 +0100105 u32 nr_max; /* max NR. Depends on tunnel */
106 u32 nr_window_size; /* NR window size */
James Chapmana0dbd822013-07-02 20:29:00 +0100107 u32 nr_oos; /* NR of last OOS packet */
108 int nr_oos_count; /* For OOS recovery */
109 int nr_oos_count_max;
James Chapmanfd558d12010-04-02 06:18:33 +0000110 struct hlist_node hlist; /* Hash list node */
111 atomic_t ref_count;
112
113 char name[32]; /* for logging */
James Chapman309795f2010-04-02 06:19:10 +0000114 char ifname[IFNAMSIZ];
Eric Dumazet95c96172012-04-15 05:58:06 +0000115 unsigned int data_seq:2; /* data sequencing level
James Chapmanfd558d12010-04-02 06:18:33 +0000116 * 0 => none, 1 => IP only,
117 * 2 => all
118 */
Eric Dumazet95c96172012-04-15 05:58:06 +0000119 unsigned int recv_seq:1; /* expect receive packets with
James Chapmanfd558d12010-04-02 06:18:33 +0000120 * sequence numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +0000121 unsigned int send_seq:1; /* send packets with sequence
James Chapmanfd558d12010-04-02 06:18:33 +0000122 * numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +0000123 unsigned int lns_mode:1; /* behave as LNS? LAC enables
James Chapmanfd558d12010-04-02 06:18:33 +0000124 * sequence numbers under
125 * control of LNS. */
126 int debug; /* bitmask of debug message
127 * categories */
128 int reorder_timeout; /* configured reorder timeout
129 * (in jiffies) */
James Chapman38d40b32012-05-09 23:43:08 +0000130 int reorder_skip; /* set if skip to next nr */
James Chapmanfd558d12010-04-02 06:18:33 +0000131 int mtu;
132 int mru;
James Chapmanf7faffa2010-04-02 06:18:49 +0000133 enum l2tp_pwtype pwtype;
James Chapmanfd558d12010-04-02 06:18:33 +0000134 struct l2tp_stats stats;
James Chapmanf7faffa2010-04-02 06:18:49 +0000135 struct hlist_node global_hlist; /* Global hash list node */
James Chapmanfd558d12010-04-02 06:18:33 +0000136
James Chapmanf7faffa2010-04-02 06:18:49 +0000137 int (*build_header)(struct l2tp_session *session, void *buf);
James Chapmanfd558d12010-04-02 06:18:33 +0000138 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
139 void (*session_close)(struct l2tp_session *session);
140 void (*ref)(struct l2tp_session *session);
141 void (*deref)(struct l2tp_session *session);
Javier Martinez Canillas9dd79942016-09-09 08:43:17 -0400142#if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
James Chapman0ad66142010-04-02 06:19:33 +0000143 void (*show)(struct seq_file *m, void *priv);
144#endif
James Chapmanfd558d12010-04-02 06:18:33 +0000145 uint8_t priv[0]; /* private data */
146};
147
148/* Describes the tunnel. It contains info to track all the associated
149 * sessions so incoming packets can be sorted out
150 */
151struct l2tp_tunnel_cfg {
152 int debug; /* bitmask of debug message
153 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000154 enum l2tp_encap_type encap;
James Chapman789a4a22010-04-02 06:19:40 +0000155
156 /* Used only for kernel-created sockets */
157 struct in_addr local_ip;
158 struct in_addr peer_ip;
Chris Elstonf9bac8d2012-04-29 21:48:52 +0000159#if IS_ENABLED(CONFIG_IPV6)
160 struct in6_addr *local_ip6;
161 struct in6_addr *peer_ip6;
162#endif
James Chapman789a4a22010-04-02 06:19:40 +0000163 u16 local_udp_port;
164 u16 peer_udp_port;
Tom Herbert6b649fea2014-05-23 08:47:40 -0700165 unsigned int use_udp_checksums:1,
166 udp6_zero_tx_checksums:1,
167 udp6_zero_rx_checksums:1;
James Chapmanfd558d12010-04-02 06:18:33 +0000168};
169
170struct l2tp_tunnel {
171 int magic; /* Should be L2TP_TUNNEL_MAGIC */
xeb@mail.ru99469c32012-08-24 01:07:38 +0000172 struct rcu_head rcu;
James Chapmanfd558d12010-04-02 06:18:33 +0000173 rwlock_t hlist_lock; /* protect session_hlist */
174 struct hlist_head session_hlist[L2TP_HASH_SIZE];
175 /* hashed list of sessions,
176 * hashed by id */
177 u32 tunnel_id;
178 u32 peer_tunnel_id;
179 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
180
181 char name[20]; /* for logging */
182 int debug; /* bitmask of debug message
183 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000184 enum l2tp_encap_type encap;
James Chapmanfd558d12010-04-02 06:18:33 +0000185 struct l2tp_stats stats;
186
187 struct list_head list; /* Keep a list of all tunnels */
188 struct net *l2tp_net; /* the net we belong to */
189
190 atomic_t ref_count;
James Chapman0ad66142010-04-02 06:19:33 +0000191#ifdef CONFIG_DEBUG_FS
192 void (*show)(struct seq_file *m, void *arg);
193#endif
James Chapmanfd558d12010-04-02 06:18:33 +0000194 int (*recv_payload_hook)(struct sk_buff *skb);
195 void (*old_sk_destruct)(struct sock *);
196 struct sock *sock; /* Parent socket */
Tom Parkin80d84ef2013-01-22 05:13:48 +0000197 int fd; /* Parent fd, if tunnel socket
198 * was created by userspace */
François Cachereule18503f2013-10-02 10:16:02 +0200199#if IS_ENABLED(CONFIG_IPV6)
200 bool v4mapped;
201#endif
James Chapmanfd558d12010-04-02 06:18:33 +0000202
Tom Parkinf8ccac02013-01-31 23:43:00 +0000203 struct work_struct del_work;
204
James Chapmanfd558d12010-04-02 06:18:33 +0000205 uint8_t priv[0]; /* private data */
206};
207
James Chapman309795f2010-04-02 06:19:10 +0000208struct l2tp_nl_cmd_ops {
209 int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
210 int (*session_delete)(struct l2tp_session *session);
211};
212
James Chapmanfd558d12010-04-02 06:18:33 +0000213static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
214{
215 return &tunnel->priv[0];
216}
217
218static inline void *l2tp_session_priv(struct l2tp_session *session)
219{
220 return &session->priv[0];
221}
222
223static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
224{
225 struct l2tp_tunnel *tunnel;
226
227 if (sk == NULL)
228 return NULL;
229
230 sock_hold(sk);
231 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
232 if (tunnel == NULL) {
233 sock_put(sk);
234 goto out;
235 }
236
237 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
238
239out:
240 return tunnel;
241}
242
Joe Perchesc1b12032013-10-18 13:48:25 -0700243struct l2tp_session *l2tp_session_find(struct net *net,
244 struct l2tp_tunnel *tunnel,
245 u32 session_id);
246struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
247struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
248struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
249struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
James Chapmanfd558d12010-04-02 06:18:33 +0000250
Joe Perchesc1b12032013-10-18 13:48:25 -0700251int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
252 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
253 struct l2tp_tunnel **tunnelp);
254void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
255int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
256struct l2tp_session *l2tp_session_create(int priv_size,
257 struct l2tp_tunnel *tunnel,
258 u32 session_id, u32 peer_session_id,
259 struct l2tp_session_cfg *cfg);
260void __l2tp_session_unhash(struct l2tp_session *session);
261int l2tp_session_delete(struct l2tp_session *session);
262void l2tp_session_free(struct l2tp_session *session);
263void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
264 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
265 int length, int (*payload_hook)(struct sk_buff *skb));
266int l2tp_session_queue_purge(struct l2tp_session *session);
267int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
Guillaume Naultbb5016e2014-03-06 11:14:30 +0100268void l2tp_session_set_header_len(struct l2tp_session *session, int version);
James Chapmanfd558d12010-04-02 06:18:33 +0000269
Joe Perchesc1b12032013-10-18 13:48:25 -0700270int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
271 int hdr_len);
James Chapmanfd558d12010-04-02 06:18:33 +0000272
Joe Perchesc1b12032013-10-18 13:48:25 -0700273int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
274 const struct l2tp_nl_cmd_ops *ops);
275void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
James Chapman309795f2010-04-02 06:19:10 +0000276
James Chapmanfd558d12010-04-02 06:18:33 +0000277/* Session reference counts. Incremented when code obtains a reference
278 * to a session.
279 */
280static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
281{
282 atomic_inc(&session->ref_count);
283}
284
285static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
286{
287 if (atomic_dec_and_test(&session->ref_count))
288 l2tp_session_free(session);
289}
290
291#ifdef L2TP_REFCNT_DEBUG
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000292#define l2tp_session_inc_refcount(_s) \
293do { \
294 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
295 __func__, __LINE__, (_s)->name, \
296 atomic_read(&_s->ref_count)); \
297 l2tp_session_inc_refcount_1(_s); \
298} while (0)
299#define l2tp_session_dec_refcount(_s) \
300do { \
301 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
302 __func__, __LINE__, (_s)->name, \
303 atomic_read(&_s->ref_count)); \
304 l2tp_session_dec_refcount_1(_s); \
305} while (0)
James Chapmanfd558d12010-04-02 06:18:33 +0000306#else
307#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
308#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
309#endif
310
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000311#define l2tp_printk(ptr, type, func, fmt, ...) \
312do { \
313 if (((ptr)->debug) & (type)) \
314 func(fmt, ##__VA_ARGS__); \
315} while (0)
316
317#define l2tp_warn(ptr, type, fmt, ...) \
318 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
319#define l2tp_info(ptr, type, fmt, ...) \
320 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
321#define l2tp_dbg(ptr, type, fmt, ...) \
322 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
323
stephen hemmingerf1f39f92015-09-23 21:33:34 -0700324#define MODULE_ALIAS_L2TP_PWTYPE(type) \
325 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
326
James Chapmanfd558d12010-04-02 06:18:33 +0000327#endif /* _L2TP_CORE_H_ */