Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[GitHub/mt8127/android_kernel_alcatel_ttab.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 */
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
f7faffa3 18/* Per tunnel, session hash table size */
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19#define L2TP_HASH_BITS 4
20#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
21
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22/* 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
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26/* 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;
f7faffa3 47 u64 rx_cookie_discards;
5de7aee5 48 struct u64_stats_sync syncp;
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49};
50
51struct l2tp_tunnel;
52
53/* Describes a session. Contains information to determine incoming
54 * packets and transmit outgoing ones.
55 */
56struct l2tp_session_cfg {
f7faffa3 57 enum l2tp_pwtype pw_type;
95c96174 58 unsigned int data_seq:2; /* data sequencing level
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59 * 0 => none, 1 => IP only,
60 * 2 => all
61 */
95c96174 62 unsigned int recv_seq:1; /* expect receive packets with
fd558d18 63 * sequence numbers? */
95c96174 64 unsigned int send_seq:1; /* send packets with sequence
fd558d18 65 * numbers? */
95c96174 66 unsigned int lns_mode:1; /* behave as LNS? LAC enables
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67 * sequence numbers under
68 * control of LNS. */
69 int debug; /* bitmask of debug message
70 * categories */
309795f4 71 u16 vlan_id; /* VLAN pseudowire only */
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72 u16 offset; /* offset to payload */
73 u16 l2specific_len; /* Layer 2 specific length */
74 u16 l2specific_type; /* Layer 2 specific type */
75 u8 cookie[8]; /* optional cookie */
76 int cookie_len; /* 0, 4 or 8 bytes */
77 u8 peer_cookie[8]; /* peer's cookie */
78 int peer_cookie_len; /* 0, 4 or 8 bytes */
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79 int reorder_timeout; /* configured reorder timeout
80 * (in jiffies) */
81 int mtu;
82 int mru;
309795f4 83 char *ifname;
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84};
85
86struct l2tp_session {
87 int magic; /* should be
88 * L2TP_SESSION_MAGIC */
89
90 struct l2tp_tunnel *tunnel; /* back pointer to tunnel
91 * context */
92 u32 session_id;
93 u32 peer_session_id;
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94 u8 cookie[8];
95 int cookie_len;
96 u8 peer_cookie[8];
97 int peer_cookie_len;
98 u16 offset; /* offset from end of L2TP header
99 to beginning of data */
100 u16 l2specific_len;
101 u16 l2specific_type;
102 u16 hdr_len;
103 u32 nr; /* session NR state (receive) */
104 u32 ns; /* session NR state (send) */
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105 struct sk_buff_head reorder_q; /* receive reorder queue */
106 struct hlist_node hlist; /* Hash list node */
107 atomic_t ref_count;
108
109 char name[32]; /* for logging */
309795f4 110 char ifname[IFNAMSIZ];
95c96174 111 unsigned int data_seq:2; /* data sequencing level
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112 * 0 => none, 1 => IP only,
113 * 2 => all
114 */
95c96174 115 unsigned int recv_seq:1; /* expect receive packets with
fd558d18 116 * sequence numbers? */
95c96174 117 unsigned int send_seq:1; /* send packets with sequence
fd558d18 118 * numbers? */
95c96174 119 unsigned int lns_mode:1; /* behave as LNS? LAC enables
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120 * sequence numbers under
121 * control of LNS. */
122 int debug; /* bitmask of debug message
123 * categories */
124 int reorder_timeout; /* configured reorder timeout
125 * (in jiffies) */
38d40b3f 126 int reorder_skip; /* set if skip to next nr */
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127 int mtu;
128 int mru;
f7faffa3 129 enum l2tp_pwtype pwtype;
fd558d18 130 struct l2tp_stats stats;
f7faffa3 131 struct hlist_node global_hlist; /* Global hash list node */
fd558d18 132
f7faffa3 133 int (*build_header)(struct l2tp_session *session, void *buf);
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134 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
135 void (*session_close)(struct l2tp_session *session);
136 void (*ref)(struct l2tp_session *session);
137 void (*deref)(struct l2tp_session *session);
f66ef2d0 138#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
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139 void (*show)(struct seq_file *m, void *priv);
140#endif
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141 uint8_t priv[0]; /* private data */
142};
143
144/* Describes the tunnel. It contains info to track all the associated
145 * sessions so incoming packets can be sorted out
146 */
147struct l2tp_tunnel_cfg {
148 int debug; /* bitmask of debug message
149 * categories */
0d76751f 150 enum l2tp_encap_type encap;
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151
152 /* Used only for kernel-created sockets */
153 struct in_addr local_ip;
154 struct in_addr peer_ip;
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155#if IS_ENABLED(CONFIG_IPV6)
156 struct in6_addr *local_ip6;
157 struct in6_addr *peer_ip6;
158#endif
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159 u16 local_udp_port;
160 u16 peer_udp_port;
7bddd0db 161 unsigned int use_udp_checksums:1;
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162};
163
164struct l2tp_tunnel {
165 int magic; /* Should be L2TP_TUNNEL_MAGIC */
166 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 */
0d76751f 177 enum l2tp_encap_type encap;
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178 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;
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184#ifdef CONFIG_DEBUG_FS
185 void (*show)(struct seq_file *m, void *arg);
186#endif
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187 int (*recv_payload_hook)(struct sk_buff *skb);
188 void (*old_sk_destruct)(struct sock *);
189 struct sock *sock; /* Parent socket */
190 int fd;
191
192 uint8_t priv[0]; /* private data */
193};
194
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195struct l2tp_nl_cmd_ops {
196 int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
197 int (*session_delete)(struct l2tp_session *session);
198};
199
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200static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
201{
202 return &tunnel->priv[0];
203}
204
205static inline void *l2tp_session_priv(struct l2tp_session *session)
206{
207 return &session->priv[0];
208}
209
210static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
211{
212 struct l2tp_tunnel *tunnel;
213
214 if (sk == NULL)
215 return NULL;
216
217 sock_hold(sk);
218 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
219 if (tunnel == NULL) {
220 sock_put(sk);
221 goto out;
222 }
223
224 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
225
226out:
227 return tunnel;
228}
229
f7faffa3 230extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
fd558d18 231extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
309795f4 232extern struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
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233extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
234extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
235
236extern 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);
309795f4 237extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
fd558d18 238extern 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);
309795f4 239extern int l2tp_session_delete(struct l2tp_session *session);
fd558d18 240extern void l2tp_session_free(struct l2tp_session *session);
f7faffa3 241extern 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));
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242extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
243
fd558d18 244extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
fd558d18 245
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246extern int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
247extern void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
248
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249/* Session reference counts. Incremented when code obtains a reference
250 * to a session.
251 */
252static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
253{
254 atomic_inc(&session->ref_count);
255}
256
257static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
258{
259 if (atomic_dec_and_test(&session->ref_count))
260 l2tp_session_free(session);
261}
262
263#ifdef L2TP_REFCNT_DEBUG
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264#define l2tp_session_inc_refcount(_s) \
265do { \
266 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
267 __func__, __LINE__, (_s)->name, \
268 atomic_read(&_s->ref_count)); \
269 l2tp_session_inc_refcount_1(_s); \
270} while (0)
271#define l2tp_session_dec_refcount(_s) \
272do { \
273 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
274 __func__, __LINE__, (_s)->name, \
275 atomic_read(&_s->ref_count)); \
276 l2tp_session_dec_refcount_1(_s); \
277} while (0)
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278#else
279#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
280#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
281#endif
282
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283#define l2tp_printk(ptr, type, func, fmt, ...) \
284do { \
285 if (((ptr)->debug) & (type)) \
286 func(fmt, ##__VA_ARGS__); \
287} while (0)
288
289#define l2tp_warn(ptr, type, fmt, ...) \
290 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
291#define l2tp_info(ptr, type, fmt, ...) \
292 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
293#define l2tp_dbg(ptr, type, fmt, ...) \
294 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
295
fd558d18 296#endif /* _L2TP_CORE_H_ */