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11#ifndef _L2TP_CORE_H_
12#define _L2TP_CORE_H_
13
14
15#define L2TP_TUNNEL_MAGIC 0x42114DDA
16#define L2TP_SESSION_MAGIC 0x0C04EB7D
17
18
19#define L2TP_HASH_BITS 4
20#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
21
22
23#define L2TP_HASH_BITS_2 8
24#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
25
26
27enum {
28 L2TP_MSG_DEBUG = (1 << 0),
29
30 L2TP_MSG_CONTROL = (1 << 1),
31
32 L2TP_MSG_SEQ = (1 << 2),
33 L2TP_MSG_DATA = (1 << 3),
34};
35
36struct sk_buff;
37
38struct l2tp_stats {
39 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;
48};
49
50struct l2tp_tunnel;
51
52
53
54
55struct l2tp_session_cfg {
56 enum l2tp_pwtype pw_type;
57 unsigned int data_seq:2;
58
59
60
61 unsigned int recv_seq:1;
62
63 unsigned int send_seq:1;
64
65 unsigned int lns_mode:1;
66
67
68 int debug;
69
70 u16 vlan_id;
71 u16 offset;
72 u16 l2specific_len;
73 u16 l2specific_type;
74 u8 cookie[8];
75 int cookie_len;
76 u8 peer_cookie[8];
77 int peer_cookie_len;
78 int reorder_timeout;
79
80 int mtu;
81 int mru;
82 char *ifname;
83};
84
85struct l2tp_session {
86 int magic;
87
88
89 struct l2tp_tunnel *tunnel;
90
91 u32 session_id;
92 u32 peer_session_id;
93 u8 cookie[8];
94 int cookie_len;
95 u8 peer_cookie[8];
96 int peer_cookie_len;
97 u16 offset;
98
99 u16 l2specific_len;
100 u16 l2specific_type;
101 u16 hdr_len;
102 u32 nr;
103 u32 ns;
104 struct sk_buff_head reorder_q;
105 u32 nr_max;
106 u32 nr_window_size;
107 u32 nr_oos;
108 int nr_oos_count;
109 int nr_oos_count_max;
110 struct hlist_node hlist;
111 atomic_t ref_count;
112
113 char name[32];
114 char ifname[IFNAMSIZ];
115 unsigned int data_seq:2;
116
117
118
119 unsigned int recv_seq:1;
120
121 unsigned int send_seq:1;
122
123 unsigned int lns_mode:1;
124
125
126 int debug;
127
128 int reorder_timeout;
129
130 int reorder_skip;
131 int mtu;
132 int mru;
133 enum l2tp_pwtype pwtype;
134 struct l2tp_stats stats;
135 struct hlist_node global_hlist;
136
137 int (*build_header)(struct l2tp_session *session, void *buf);
138 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);
142#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
143 void (*show)(struct seq_file *m, void *priv);
144#endif
145 uint8_t priv[0];
146};
147
148
149
150
151struct l2tp_tunnel_cfg {
152 int debug;
153
154 enum l2tp_encap_type encap;
155
156
157 struct in_addr local_ip;
158 struct in_addr peer_ip;
159#if IS_ENABLED(CONFIG_IPV6)
160 struct in6_addr *local_ip6;
161 struct in6_addr *peer_ip6;
162#endif
163 u16 local_udp_port;
164 u16 peer_udp_port;
165 unsigned int use_udp_checksums:1;
166};
167
168struct l2tp_tunnel {
169 int magic;
170 struct rcu_head rcu;
171 rwlock_t hlist_lock;
172 struct hlist_head session_hlist[L2TP_HASH_SIZE];
173
174
175 u32 tunnel_id;
176 u32 peer_tunnel_id;
177 int version;
178
179 char name[20];
180 int debug;
181
182 enum l2tp_encap_type encap;
183 struct l2tp_stats stats;
184
185 struct list_head list;
186 struct net *l2tp_net;
187
188 atomic_t ref_count;
189#ifdef CONFIG_DEBUG_FS
190 void (*show)(struct seq_file *m, void *arg);
191#endif
192 int (*recv_payload_hook)(struct sk_buff *skb);
193 void (*old_sk_destruct)(struct sock *);
194 struct sock *sock;
195 int fd;
196
197#if IS_ENABLED(CONFIG_IPV6)
198 bool v4mapped;
199#endif
200
201 struct work_struct del_work;
202
203 uint8_t priv[0];
204};
205
206struct l2tp_nl_cmd_ops {
207 int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
208 int (*session_delete)(struct l2tp_session *session);
209};
210
211static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
212{
213 return &tunnel->priv[0];
214}
215
216static inline void *l2tp_session_priv(struct l2tp_session *session)
217{
218 return &session->priv[0];
219}
220
221static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
222{
223 struct l2tp_tunnel *tunnel;
224
225 if (sk == NULL)
226 return NULL;
227
228 sock_hold(sk);
229 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
230 if (tunnel == NULL) {
231 sock_put(sk);
232 goto out;
233 }
234
235 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
236
237out:
238 return tunnel;
239}
240
241extern struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel);
242extern void l2tp_tunnel_sock_put(struct sock *sk);
243extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
244extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
245extern struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
246extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
247extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
248
249extern 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);
250extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
251extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
252extern 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);
253extern void __l2tp_session_unhash(struct l2tp_session *session);
254extern int l2tp_session_delete(struct l2tp_session *session);
255extern void l2tp_session_free(struct l2tp_session *session);
256extern 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));
257extern int l2tp_session_queue_purge(struct l2tp_session *session);
258extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
259
260extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
261
262extern int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
263extern void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
264
265
266
267
268static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
269{
270 atomic_inc(&session->ref_count);
271}
272
273static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
274{
275 if (atomic_dec_and_test(&session->ref_count))
276 l2tp_session_free(session);
277}
278
279#ifdef L2TP_REFCNT_DEBUG
280#define l2tp_session_inc_refcount(_s) \
281do { \
282 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
283 __func__, __LINE__, (_s)->name, \
284 atomic_read(&_s->ref_count)); \
285 l2tp_session_inc_refcount_1(_s); \
286} while (0)
287#define l2tp_session_dec_refcount(_s) \
288do { \
289 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
290 __func__, __LINE__, (_s)->name, \
291 atomic_read(&_s->ref_count)); \
292 l2tp_session_dec_refcount_1(_s); \
293} while (0)
294#else
295#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
296#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
297#endif
298
299#define l2tp_printk(ptr, type, func, fmt, ...) \
300do { \
301 if (((ptr)->debug) & (type)) \
302 func(fmt, ##__VA_ARGS__); \
303} while (0)
304
305#define l2tp_warn(ptr, type, fmt, ...) \
306 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
307#define l2tp_info(ptr, type, fmt, ...) \
308 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
309#define l2tp_dbg(ptr, type, fmt, ...) \
310 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
311
312#endif
313