2 * L2TP internal definitions.
4 * Copyright (c) 2008,2009 Katalix Systems Ltd
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.
10 #include <linux/refcount.h>
22 /* Just some random numbers */
23 #define L2TP_TUNNEL_MAGIC 0x42114DDA
24 #define L2TP_SESSION_MAGIC 0x0C04EB7D
26 /* Per tunnel, session hash table size */
27 #define L2TP_HASH_BITS 4
28 #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
30 /* System-wide, session hash table size */
31 #define L2TP_HASH_BITS_2 8
32 #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
37 atomic_long_t tx_packets
;
38 atomic_long_t tx_bytes
;
39 atomic_long_t tx_errors
;
40 atomic_long_t rx_packets
;
41 atomic_long_t rx_bytes
;
42 atomic_long_t rx_seq_discards
;
43 atomic_long_t rx_oos_packets
;
44 atomic_long_t rx_errors
;
45 atomic_long_t rx_cookie_discards
;
50 /* Describes a session. Contains information to determine incoming
51 * packets and transmit outgoing ones.
53 struct l2tp_session_cfg
{
54 enum l2tp_pwtype pw_type
;
55 unsigned int recv_seq
:1; /* expect receive packets with
56 * sequence numbers? */
57 unsigned int send_seq
:1; /* send packets with sequence
59 unsigned int lns_mode
:1; /* behave as LNS? LAC enables
60 * sequence numbers under
62 int debug
; /* bitmask of debug message
64 u16 l2specific_type
; /* Layer 2 specific type */
65 u8 cookie
[8]; /* optional cookie */
66 int cookie_len
; /* 0, 4 or 8 bytes */
67 u8 peer_cookie
[8]; /* peer's cookie */
68 int peer_cookie_len
; /* 0, 4 or 8 bytes */
69 int reorder_timeout
; /* configured reorder timeout
75 int magic
; /* should be
76 * L2TP_SESSION_MAGIC */
79 struct l2tp_tunnel
*tunnel
; /* back pointer to tunnel
89 u32 nr
; /* session NR state (receive) */
90 u32 ns
; /* session NR state (send) */
91 struct sk_buff_head reorder_q
; /* receive reorder queue */
92 u32 nr_max
; /* max NR. Depends on tunnel */
93 u32 nr_window_size
; /* NR window size */
94 u32 nr_oos
; /* NR of last OOS packet */
95 int nr_oos_count
; /* For OOS recovery */
97 struct hlist_node hlist
; /* Hash list node */
100 char name
[32]; /* for logging */
101 char ifname
[IFNAMSIZ
];
102 unsigned int recv_seq
:1; /* expect receive packets with
103 * sequence numbers? */
104 unsigned int send_seq
:1; /* send packets with sequence
106 unsigned int lns_mode
:1; /* behave as LNS? LAC enables
107 * sequence numbers under
109 int debug
; /* bitmask of debug message
111 int reorder_timeout
; /* configured reorder timeout
113 int reorder_skip
; /* set if skip to next nr */
114 enum l2tp_pwtype pwtype
;
115 struct l2tp_stats stats
;
116 struct hlist_node global_hlist
; /* Global hash list node */
118 int (*build_header
)(struct l2tp_session
*session
, void *buf
);
119 void (*recv_skb
)(struct l2tp_session
*session
, struct sk_buff
*skb
, int data_len
);
120 void (*session_close
)(struct l2tp_session
*session
);
121 void (*show
)(struct seq_file
*m
, void *priv
);
122 uint8_t priv
[0]; /* private data */
125 /* Describes the tunnel. It contains info to track all the associated
126 * sessions so incoming packets can be sorted out
128 struct l2tp_tunnel_cfg
{
129 int debug
; /* bitmask of debug message
131 enum l2tp_encap_type encap
;
133 /* Used only for kernel-created sockets */
134 struct in_addr local_ip
;
135 struct in_addr peer_ip
;
136 #if IS_ENABLED(CONFIG_IPV6)
137 struct in6_addr
*local_ip6
;
138 struct in6_addr
*peer_ip6
;
142 unsigned int use_udp_checksums
:1,
143 udp6_zero_tx_checksums
:1,
144 udp6_zero_rx_checksums
:1;
148 int magic
; /* Should be L2TP_TUNNEL_MAGIC */
153 rwlock_t hlist_lock
; /* protect session_hlist */
154 bool acpt_newsess
; /* Indicates whether this
155 * tunnel accepts new sessions.
156 * Protected by hlist_lock.
158 struct hlist_head session_hlist
[L2TP_HASH_SIZE
];
159 /* hashed list of sessions,
163 int version
; /* 2=>L2TPv2, 3=>L2TPv3 */
165 char name
[20]; /* for logging */
166 int debug
; /* bitmask of debug message
168 enum l2tp_encap_type encap
;
169 struct l2tp_stats stats
;
171 struct list_head list
; /* Keep a list of all tunnels */
172 struct net
*l2tp_net
; /* the net we belong to */
174 refcount_t ref_count
;
175 void (*old_sk_destruct
)(struct sock
*);
176 struct sock
*sock
; /* Parent socket */
177 int fd
; /* Parent fd, if tunnel socket
178 * was created by userspace */
180 struct work_struct del_work
;
183 struct l2tp_nl_cmd_ops
{
184 int (*session_create
)(struct net
*net
, struct l2tp_tunnel
*tunnel
,
185 u32 session_id
, u32 peer_session_id
,
186 struct l2tp_session_cfg
*cfg
);
187 int (*session_delete
)(struct l2tp_session
*session
);
190 static inline void *l2tp_session_priv(struct l2tp_session
*session
)
192 return &session
->priv
[0];
195 struct l2tp_tunnel
*l2tp_tunnel_get(const struct net
*net
, u32 tunnel_id
);
196 struct l2tp_tunnel
*l2tp_tunnel_get_nth(const struct net
*net
, int nth
);
197 struct l2tp_session
*l2tp_tunnel_get_session(struct l2tp_tunnel
*tunnel
,
200 void l2tp_tunnel_free(struct l2tp_tunnel
*tunnel
);
202 struct l2tp_session
*l2tp_session_get(const struct net
*net
, u32 session_id
);
203 struct l2tp_session
*l2tp_session_get_nth(struct l2tp_tunnel
*tunnel
, int nth
);
204 struct l2tp_session
*l2tp_session_get_by_ifname(const struct net
*net
,
207 int l2tp_tunnel_create(struct net
*net
, int fd
, int version
, u32 tunnel_id
,
208 u32 peer_tunnel_id
, struct l2tp_tunnel_cfg
*cfg
,
209 struct l2tp_tunnel
**tunnelp
);
210 int l2tp_tunnel_register(struct l2tp_tunnel
*tunnel
, struct net
*net
,
211 struct l2tp_tunnel_cfg
*cfg
);
213 void l2tp_tunnel_delete(struct l2tp_tunnel
*tunnel
);
214 struct l2tp_session
*l2tp_session_create(int priv_size
,
215 struct l2tp_tunnel
*tunnel
,
216 u32 session_id
, u32 peer_session_id
,
217 struct l2tp_session_cfg
*cfg
);
218 int l2tp_session_register(struct l2tp_session
*session
,
219 struct l2tp_tunnel
*tunnel
);
221 void __l2tp_session_unhash(struct l2tp_session
*session
);
222 int l2tp_session_delete(struct l2tp_session
*session
);
223 void l2tp_session_free(struct l2tp_session
*session
);
224 void l2tp_recv_common(struct l2tp_session
*session
, struct sk_buff
*skb
,
225 unsigned char *ptr
, unsigned char *optr
, u16 hdrflags
,
227 int l2tp_udp_encap_recv(struct sock
*sk
, struct sk_buff
*skb
);
228 void l2tp_session_set_header_len(struct l2tp_session
*session
, int version
);
230 int l2tp_xmit_skb(struct l2tp_session
*session
, struct sk_buff
*skb
,
233 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type
,
234 const struct l2tp_nl_cmd_ops
*ops
);
235 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type
);
236 int l2tp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
);
238 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel
*tunnel
)
240 refcount_inc(&tunnel
->ref_count
);
243 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel
*tunnel
)
245 if (refcount_dec_and_test(&tunnel
->ref_count
))
246 l2tp_tunnel_free(tunnel
);
249 /* Session reference counts. Incremented when code obtains a reference
252 static inline void l2tp_session_inc_refcount(struct l2tp_session
*session
)
254 refcount_inc(&session
->ref_count
);
257 static inline void l2tp_session_dec_refcount(struct l2tp_session
*session
)
259 if (refcount_dec_and_test(&session
->ref_count
))
260 l2tp_session_free(session
);
263 static inline int l2tp_get_l2specific_len(struct l2tp_session
*session
)
265 switch (session
->l2specific_type
) {
266 case L2TP_L2SPECTYPE_DEFAULT
:
268 case L2TP_L2SPECTYPE_NONE
:
274 static inline u32
l2tp_tunnel_dst_mtu(const struct l2tp_tunnel
*tunnel
)
276 struct dst_entry
*dst
;
279 dst
= sk_dst_get(tunnel
->sock
);
290 static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel
*tunnel
)
292 struct sock
*sk
= tunnel
->sock
;
294 return sk
&& (rcu_access_pointer(sk
->sk_policy
[0]) ||
295 rcu_access_pointer(sk
->sk_policy
[1]));
298 static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel
*tunnel
)
304 #define l2tp_printk(ptr, type, func, fmt, ...) \
306 if (((ptr)->debug) & (type)) \
307 func(fmt, ##__VA_ARGS__); \
310 #define l2tp_warn(ptr, type, fmt, ...) \
311 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
312 #define l2tp_info(ptr, type, fmt, ...) \
313 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
314 #define l2tp_dbg(ptr, type, fmt, ...) \
315 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
317 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
318 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
320 #endif /* _L2TP_CORE_H_ */