Merge branch 'hns3-next'
[linux-2.6-block.git] / net / l2tp / l2tp_core.h
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1/*
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 */
fbea9e07 10#include <linux/refcount.h>
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11
12#ifndef _L2TP_CORE_H_
13#define _L2TP_CORE_H_
14
15/* Just some random numbers */
16#define L2TP_TUNNEL_MAGIC 0x42114DDA
17#define L2TP_SESSION_MAGIC 0x0C04EB7D
18
f7faffa3 19/* Per tunnel, session hash table size */
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20#define L2TP_HASH_BITS 4
21#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
22
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23/* System-wide, session hash table size */
24#define L2TP_HASH_BITS_2 8
25#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
26
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27struct sk_buff;
28
29struct l2tp_stats {
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30 atomic_long_t tx_packets;
31 atomic_long_t tx_bytes;
32 atomic_long_t tx_errors;
33 atomic_long_t rx_packets;
34 atomic_long_t rx_bytes;
35 atomic_long_t rx_seq_discards;
36 atomic_long_t rx_oos_packets;
37 atomic_long_t rx_errors;
38 atomic_long_t rx_cookie_discards;
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39};
40
41struct l2tp_tunnel;
42
43/* Describes a session. Contains information to determine incoming
44 * packets and transmit outgoing ones.
45 */
46struct l2tp_session_cfg {
f7faffa3 47 enum l2tp_pwtype pw_type;
95c96174 48 unsigned int recv_seq:1; /* expect receive packets with
fd558d18 49 * sequence numbers? */
95c96174 50 unsigned int send_seq:1; /* send packets with sequence
fd558d18 51 * numbers? */
95c96174 52 unsigned int lns_mode:1; /* behave as LNS? LAC enables
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53 * sequence numbers under
54 * control of LNS. */
55 int debug; /* bitmask of debug message
56 * categories */
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57 u16 l2specific_type; /* Layer 2 specific type */
58 u8 cookie[8]; /* optional cookie */
59 int cookie_len; /* 0, 4 or 8 bytes */
60 u8 peer_cookie[8]; /* peer's cookie */
61 int peer_cookie_len; /* 0, 4 or 8 bytes */
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62 int reorder_timeout; /* configured reorder timeout
63 * (in jiffies) */
64 int mtu;
309795f4 65 char *ifname;
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66};
67
68struct l2tp_session {
69 int magic; /* should be
70 * L2TP_SESSION_MAGIC */
b228a940 71 long dead;
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72
73 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
74 * context */
75 u32 session_id;
76 u32 peer_session_id;
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77 u8 cookie[8];
78 int cookie_len;
79 u8 peer_cookie[8];
80 int peer_cookie_len;
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81 u16 l2specific_type;
82 u16 hdr_len;
83 u32 nr; /* session NR state (receive) */
84 u32 ns; /* session NR state (send) */
fd558d18 85 struct sk_buff_head reorder_q; /* receive reorder queue */
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86 u32 nr_max; /* max NR. Depends on tunnel */
87 u32 nr_window_size; /* NR window size */
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88 u32 nr_oos; /* NR of last OOS packet */
89 int nr_oos_count; /* For OOS recovery */
90 int nr_oos_count_max;
fd558d18 91 struct hlist_node hlist; /* Hash list node */
f00c854c 92 refcount_t ref_count;
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93
94 char name[32]; /* for logging */
309795f4 95 char ifname[IFNAMSIZ];
95c96174 96 unsigned int recv_seq:1; /* expect receive packets with
fd558d18 97 * sequence numbers? */
95c96174 98 unsigned int send_seq:1; /* send packets with sequence
fd558d18 99 * numbers? */
95c96174 100 unsigned int lns_mode:1; /* behave as LNS? LAC enables
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101 * sequence numbers under
102 * control of LNS. */
103 int debug; /* bitmask of debug message
104 * categories */
105 int reorder_timeout; /* configured reorder timeout
106 * (in jiffies) */
38d40b3f 107 int reorder_skip; /* set if skip to next nr */
fd558d18 108 int mtu;
f7faffa3 109 enum l2tp_pwtype pwtype;
fd558d18 110 struct l2tp_stats stats;
f7faffa3 111 struct hlist_node global_hlist; /* Global hash list node */
fd558d18 112
f7faffa3 113 int (*build_header)(struct l2tp_session *session, void *buf);
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114 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
115 void (*session_close)(struct l2tp_session *session);
9dd79945 116#if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
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117 void (*show)(struct seq_file *m, void *priv);
118#endif
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119 uint8_t priv[0]; /* private data */
120};
121
122/* Describes the tunnel. It contains info to track all the associated
123 * sessions so incoming packets can be sorted out
124 */
125struct l2tp_tunnel_cfg {
126 int debug; /* bitmask of debug message
127 * categories */
0d76751f 128 enum l2tp_encap_type encap;
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129
130 /* Used only for kernel-created sockets */
131 struct in_addr local_ip;
132 struct in_addr peer_ip;
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133#if IS_ENABLED(CONFIG_IPV6)
134 struct in6_addr *local_ip6;
135 struct in6_addr *peer_ip6;
136#endif
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137 u16 local_udp_port;
138 u16 peer_udp_port;
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139 unsigned int use_udp_checksums:1,
140 udp6_zero_tx_checksums:1,
141 udp6_zero_rx_checksums:1;
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142};
143
144struct l2tp_tunnel {
145 int magic; /* Should be L2TP_TUNNEL_MAGIC */
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146
147 unsigned long dead;
148
99469c32 149 struct rcu_head rcu;
fd558d18 150 rwlock_t hlist_lock; /* protect session_hlist */
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151 bool acpt_newsess; /* Indicates whether this
152 * tunnel accepts new sessions.
153 * Protected by hlist_lock.
154 */
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155 struct hlist_head session_hlist[L2TP_HASH_SIZE];
156 /* hashed list of sessions,
157 * hashed by id */
158 u32 tunnel_id;
159 u32 peer_tunnel_id;
160 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
161
162 char name[20]; /* for logging */
163 int debug; /* bitmask of debug message
164 * categories */
0d76751f 165 enum l2tp_encap_type encap;
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166 struct l2tp_stats stats;
167
168 struct list_head list; /* Keep a list of all tunnels */
169 struct net *l2tp_net; /* the net we belong to */
170
fbea9e07 171 refcount_t ref_count;
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172 void (*old_sk_destruct)(struct sock *);
173 struct sock *sock; /* Parent socket */
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174 int fd; /* Parent fd, if tunnel socket
175 * was created by userspace */
fd558d18 176
f8ccac0e 177 struct work_struct del_work;
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178};
179
309795f4 180struct l2tp_nl_cmd_ops {
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181 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
182 u32 session_id, u32 peer_session_id,
183 struct l2tp_session_cfg *cfg);
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184 int (*session_delete)(struct l2tp_session *session);
185};
186
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187static inline void *l2tp_session_priv(struct l2tp_session *session)
188{
189 return &session->priv[0];
190}
191
54652eb1 192struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
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193struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
194
d00fa9ad 195void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
54652eb1 196
9aaef50c 197struct l2tp_session *l2tp_session_get(const struct net *net,
61b9a047 198 struct l2tp_tunnel *tunnel,
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199 u32 session_id);
200struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
9aaef50c 201struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
a4346210 202 const char *ifname);
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203
204int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
205 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
206 struct l2tp_tunnel **tunnelp);
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207int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
208 struct l2tp_tunnel_cfg *cfg);
209
62b982ee 210void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
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211struct l2tp_session *l2tp_session_create(int priv_size,
212 struct l2tp_tunnel *tunnel,
213 u32 session_id, u32 peer_session_id,
214 struct l2tp_session_cfg *cfg);
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215int l2tp_session_register(struct l2tp_session *session,
216 struct l2tp_tunnel *tunnel);
217
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218void __l2tp_session_unhash(struct l2tp_session *session);
219int l2tp_session_delete(struct l2tp_session *session);
220void l2tp_session_free(struct l2tp_session *session);
221void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
222 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
2b139e6b 223 int length);
c1b1203d 224int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
bb5016ea 225void l2tp_session_set_header_len(struct l2tp_session *session, int version);
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226
227int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
228 int hdr_len);
229
230int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
231 const struct l2tp_nl_cmd_ops *ops);
232void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
72fb96e7 233int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
309795f4 234
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235static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
236{
237 refcount_inc(&tunnel->ref_count);
238}
239
240static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
241{
242 if (refcount_dec_and_test(&tunnel->ref_count))
d00fa9ad 243 l2tp_tunnel_free(tunnel);
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244}
245
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246/* Session reference counts. Incremented when code obtains a reference
247 * to a session.
248 */
9ff672ba 249static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
fd558d18 250{
f00c854c 251 refcount_inc(&session->ref_count);
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252}
253
9ff672ba 254static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
fd558d18 255{
f00c854c 256 if (refcount_dec_and_test(&session->ref_count))
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257 l2tp_session_free(session);
258}
259
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260static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
261{
262 switch (session->l2specific_type) {
263 case L2TP_L2SPECTYPE_DEFAULT:
264 return 4;
265 case L2TP_L2SPECTYPE_NONE:
266 default:
267 return 0;
268 }
269}
270
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271#define l2tp_printk(ptr, type, func, fmt, ...) \
272do { \
273 if (((ptr)->debug) & (type)) \
274 func(fmt, ##__VA_ARGS__); \
275} while (0)
276
277#define l2tp_warn(ptr, type, fmt, ...) \
278 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
279#define l2tp_info(ptr, type, fmt, ...) \
280 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
281#define l2tp_dbg(ptr, type, fmt, ...) \
282 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
283
f1f39f91 284#define MODULE_ALIAS_L2TP_PWTYPE(type) \
285 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
286
fd558d18 287#endif /* _L2TP_CORE_H_ */