blob: 7cc49715606ec2864ca09c5b4f98fe682f406ab6 [file] [log] [blame]
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 l2specific_len; /* Layer 2 specific length */
72 u16 l2specific_type; /* Layer 2 specific type */
73 u8 cookie[8]; /* optional cookie */
74 int cookie_len; /* 0, 4 or 8 bytes */
75 u8 peer_cookie[8]; /* peer's cookie */
76 int peer_cookie_len; /* 0, 4 or 8 bytes */
James Chapmanfd558d12010-04-02 06:18:33 +000077 int reorder_timeout; /* configured reorder timeout
78 * (in jiffies) */
79 int mtu;
80 int mru;
James Chapman309795f2010-04-02 06:19:10 +000081 char *ifname;
James Chapmanfd558d12010-04-02 06:18:33 +000082};
83
84struct l2tp_session {
85 int magic; /* should be
86 * L2TP_SESSION_MAGIC */
87
88 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
89 * context */
90 u32 session_id;
91 u32 peer_session_id;
James Chapmanf7faffa2010-04-02 06:18:49 +000092 u8 cookie[8];
93 int cookie_len;
94 u8 peer_cookie[8];
95 int peer_cookie_len;
James Chapmanf7faffa2010-04-02 06:18:49 +000096 u16 l2specific_len;
97 u16 l2specific_type;
98 u16 hdr_len;
99 u32 nr; /* session NR state (receive) */
100 u32 ns; /* session NR state (send) */
James Chapmanfd558d12010-04-02 06:18:33 +0000101 struct sk_buff_head reorder_q; /* receive reorder queue */
James Chapman8a1631d2013-07-02 20:28:59 +0100102 u32 nr_max; /* max NR. Depends on tunnel */
103 u32 nr_window_size; /* NR window size */
James Chapmana0dbd822013-07-02 20:29:00 +0100104 u32 nr_oos; /* NR of last OOS packet */
105 int nr_oos_count; /* For OOS recovery */
106 int nr_oos_count_max;
James Chapmanfd558d12010-04-02 06:18:33 +0000107 struct hlist_node hlist; /* Hash list node */
108 atomic_t ref_count;
109
110 char name[32]; /* for logging */
James Chapman309795f2010-04-02 06:19:10 +0000111 char ifname[IFNAMSIZ];
Eric Dumazet95c96172012-04-15 05:58:06 +0000112 unsigned int data_seq:2; /* data sequencing level
James Chapmanfd558d12010-04-02 06:18:33 +0000113 * 0 => none, 1 => IP only,
114 * 2 => all
115 */
Eric Dumazet95c96172012-04-15 05:58:06 +0000116 unsigned int recv_seq:1; /* expect receive packets with
James Chapmanfd558d12010-04-02 06:18:33 +0000117 * sequence numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +0000118 unsigned int send_seq:1; /* send packets with sequence
James Chapmanfd558d12010-04-02 06:18:33 +0000119 * numbers? */
Eric Dumazet95c96172012-04-15 05:58:06 +0000120 unsigned int lns_mode:1; /* behave as LNS? LAC enables
James Chapmanfd558d12010-04-02 06:18:33 +0000121 * sequence numbers under
122 * control of LNS. */
123 int debug; /* bitmask of debug message
124 * categories */
125 int reorder_timeout; /* configured reorder timeout
126 * (in jiffies) */
James Chapman38d40b32012-05-09 23:43:08 +0000127 int reorder_skip; /* set if skip to next nr */
James Chapmanfd558d12010-04-02 06:18:33 +0000128 int mtu;
129 int mru;
James Chapmanf7faffa2010-04-02 06:18:49 +0000130 enum l2tp_pwtype pwtype;
James Chapmanfd558d12010-04-02 06:18:33 +0000131 struct l2tp_stats stats;
James Chapmanf7faffa2010-04-02 06:18:49 +0000132 struct hlist_node global_hlist; /* Global hash list node */
James Chapmanfd558d12010-04-02 06:18:33 +0000133
James Chapmanf7faffa2010-04-02 06:18:49 +0000134 int (*build_header)(struct l2tp_session *session, void *buf);
James Chapmanfd558d12010-04-02 06:18:33 +0000135 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
136 void (*session_close)(struct l2tp_session *session);
137 void (*ref)(struct l2tp_session *session);
138 void (*deref)(struct l2tp_session *session);
Javier Martinez Canillas9dd79942016-09-09 08:43:17 -0400139#if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
James Chapman0ad66142010-04-02 06:19:33 +0000140 void (*show)(struct seq_file *m, void *priv);
141#endif
James Chapmanfd558d12010-04-02 06:18:33 +0000142 uint8_t priv[0]; /* private data */
143};
144
145/* Describes the tunnel. It contains info to track all the associated
146 * sessions so incoming packets can be sorted out
147 */
148struct l2tp_tunnel_cfg {
149 int debug; /* bitmask of debug message
150 * categories */
James Chapman0d767512010-04-02 06:19:00 +0000151 enum l2tp_encap_type encap;
James Chapman789a4a22010-04-02 06:19:40 +0000152
153 /* Used only for kernel-created sockets */
154 struct in_addr local_ip;
155 struct in_addr peer_ip;
Chris Elstonf9bac8d2012-04-29 21:48:52 +0000156#if IS_ENABLED(CONFIG_IPV6)
157 struct in6_addr *local_ip6;
158 struct in6_addr *peer_ip6;
159#endif
James Chapman789a4a22010-04-02 06:19:40 +0000160 u16 local_udp_port;
161 u16 peer_udp_port;
Tom Herbert6b649fea2014-05-23 08:47:40 -0700162 unsigned int use_udp_checksums:1,
163 udp6_zero_tx_checksums:1,
164 udp6_zero_rx_checksums:1;
James Chapmanfd558d12010-04-02 06:18:33 +0000165};
166
167struct l2tp_tunnel {
168 int magic; /* Should be L2TP_TUNNEL_MAGIC */
Sabrina Dubrocab4a9b122017-09-26 16:16:43 +0200169
170 unsigned long dead;
171
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
Guillaume Nault6539c4f2017-03-31 13:02:25 +0200243struct l2tp_session *l2tp_session_get(struct net *net,
244 struct l2tp_tunnel *tunnel,
245 u32 session_id, bool do_ref);
Joe Perchesc1b12032013-10-18 13:48:25 -0700246struct l2tp_session *l2tp_session_find(struct net *net,
247 struct l2tp_tunnel *tunnel,
248 u32 session_id);
Guillaume Naultb7902602017-04-03 12:03:13 +0200249struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
250 bool do_ref);
Guillaume Nault08cb8e52017-03-31 13:02:30 +0200251struct l2tp_session *l2tp_session_get_by_ifname(struct net *net, char *ifname,
252 bool do_ref);
Joe Perchesc1b12032013-10-18 13:48:25 -0700253struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
254struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
James Chapmanfd558d12010-04-02 06:18:33 +0000255
Joe Perchesc1b12032013-10-18 13:48:25 -0700256int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
257 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
258 struct l2tp_tunnel **tunnelp);
259void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
Sabrina Dubrocab4a9b122017-09-26 16:16:43 +0200260void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
Joe Perchesc1b12032013-10-18 13:48:25 -0700261struct l2tp_session *l2tp_session_create(int priv_size,
262 struct l2tp_tunnel *tunnel,
263 u32 session_id, u32 peer_session_id,
264 struct l2tp_session_cfg *cfg);
265void __l2tp_session_unhash(struct l2tp_session *session);
266int l2tp_session_delete(struct l2tp_session *session);
267void l2tp_session_free(struct l2tp_session *session);
268void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
269 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
270 int length, int (*payload_hook)(struct sk_buff *skb));
271int l2tp_session_queue_purge(struct l2tp_session *session);
272int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
Guillaume Naultbb5016e2014-03-06 11:14:30 +0100273void l2tp_session_set_header_len(struct l2tp_session *session, int version);
James Chapmanfd558d12010-04-02 06:18:33 +0000274
Joe Perchesc1b12032013-10-18 13:48:25 -0700275int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
276 int hdr_len);
James Chapmanfd558d12010-04-02 06:18:33 +0000277
Joe Perchesc1b12032013-10-18 13:48:25 -0700278int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
279 const struct l2tp_nl_cmd_ops *ops);
280void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
Eric Dumazet5b1bb4c2017-02-09 16:15:52 -0800281int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
James Chapman309795f2010-04-02 06:19:10 +0000282
James Chapmanfd558d12010-04-02 06:18:33 +0000283/* Session reference counts. Incremented when code obtains a reference
284 * to a session.
285 */
286static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
287{
288 atomic_inc(&session->ref_count);
289}
290
291static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
292{
293 if (atomic_dec_and_test(&session->ref_count))
294 l2tp_session_free(session);
295}
296
297#ifdef L2TP_REFCNT_DEBUG
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000298#define l2tp_session_inc_refcount(_s) \
299do { \
300 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
301 __func__, __LINE__, (_s)->name, \
302 atomic_read(&_s->ref_count)); \
303 l2tp_session_inc_refcount_1(_s); \
304} while (0)
305#define l2tp_session_dec_refcount(_s) \
306do { \
307 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
308 __func__, __LINE__, (_s)->name, \
309 atomic_read(&_s->ref_count)); \
310 l2tp_session_dec_refcount_1(_s); \
311} while (0)
James Chapmanfd558d12010-04-02 06:18:33 +0000312#else
313#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
314#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
315#endif
316
Lorenzo Bianconi592bde82018-01-16 23:01:55 +0100317static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
318{
319 switch (session->l2specific_type) {
320 case L2TP_L2SPECTYPE_DEFAULT:
321 return 4;
322 case L2TP_L2SPECTYPE_NONE:
323 default:
324 return 0;
325 }
326}
327
Jacob Wen63f7ee62019-01-30 14:55:14 +0800328static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
329 unsigned char **ptr, unsigned char **optr)
330{
331 int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
332
333 if (opt_len > 0) {
334 int off = *ptr - *optr;
335
336 if (!pskb_may_pull(skb, off + opt_len))
337 return -1;
338
339 if (skb->data != *optr) {
340 *optr = skb->data;
341 *ptr = skb->data + off;
342 }
343 }
344
345 return 0;
346}
347
Joe Perchesa4ca44f2012-05-16 09:55:56 +0000348#define l2tp_printk(ptr, type, func, fmt, ...) \
349do { \
350 if (((ptr)->debug) & (type)) \
351 func(fmt, ##__VA_ARGS__); \
352} while (0)
353
354#define l2tp_warn(ptr, type, fmt, ...) \
355 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
356#define l2tp_info(ptr, type, fmt, ...) \
357 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
358#define l2tp_dbg(ptr, type, fmt, ...) \
359 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
360
stephen hemmingerf1f39f92015-09-23 21:33:34 -0700361#define MODULE_ALIAS_L2TP_PWTYPE(type) \
362 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
363
James Chapmanfd558d12010-04-02 06:18:33 +0000364#endif /* _L2TP_CORE_H_ */