1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* L2TP internal definitions.
4 * Copyright (c) 2008,2009 Katalix Systems Ltd
6 #include <linux/refcount.h>
18 /* Just some random numbers */
19 #define L2TP_TUNNEL_MAGIC 0x42114DDA
20 #define L2TP_SESSION_MAGIC 0x0C04EB7D
22 /* Per tunnel, session hash table size */
23 #define L2TP_HASH_BITS 4
24 #define L2TP_HASH_SIZE BIT(L2TP_HASH_BITS)
26 /* System-wide, session hash table size */
27 #define L2TP_HASH_BITS_2 8
28 #define L2TP_HASH_SIZE_2 BIT(L2TP_HASH_BITS_2)
33 atomic_long_t tx_packets;
34 atomic_long_t tx_bytes;
35 atomic_long_t tx_errors;
36 atomic_long_t rx_packets;
37 atomic_long_t rx_bytes;
38 atomic_long_t rx_seq_discards;
39 atomic_long_t rx_oos_packets;
40 atomic_long_t rx_errors;
41 atomic_long_t rx_cookie_discards;
46 /* Describes a session. Contains information to determine incoming
47 * packets and transmit outgoing ones.
49 struct l2tp_session_cfg {
50 enum l2tp_pwtype pw_type;
51 unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */
52 unsigned int send_seq:1; /* send packets with sequence numbers? */
53 unsigned int lns_mode:1; /* behave as LNS?
54 * LAC enables sequence numbers under LNS control.
56 int debug; /* bitmask of debug message categories */
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 */
62 int reorder_timeout; /* configured reorder timeout (in jiffies) */
67 int magic; /* should be L2TP_SESSION_MAGIC */
70 struct l2tp_tunnel *tunnel; /* back pointer to tunnel context */
79 u32 nr; /* session NR state (receive) */
80 u32 ns; /* session NR state (send) */
81 struct sk_buff_head reorder_q; /* receive reorder queue */
82 u32 nr_max; /* max NR. Depends on tunnel */
83 u32 nr_window_size; /* NR window size */
84 u32 nr_oos; /* NR of last OOS packet */
85 int nr_oos_count; /* for OOS recovery */
87 struct hlist_node hlist; /* hash list node */
90 char name[32]; /* for logging */
91 char ifname[IFNAMSIZ];
92 unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */
93 unsigned int send_seq:1; /* send packets with sequence numbers? */
94 unsigned int lns_mode:1; /* behave as LNS?
95 * LAC enables sequence numbers under LNS control.
97 int debug; /* bitmask of debug message categories */
98 int reorder_timeout; /* configured reorder timeout (in jiffies) */
99 int reorder_skip; /* set if skip to next nr */
100 enum l2tp_pwtype pwtype;
101 struct l2tp_stats stats;
102 struct hlist_node global_hlist; /* global hash list node */
104 int (*build_header)(struct l2tp_session *session, void *buf);
105 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
106 void (*session_close)(struct l2tp_session *session);
107 void (*show)(struct seq_file *m, void *priv);
108 u8 priv[]; /* private data */
111 /* Describes the tunnel. It contains info to track all the associated
112 * sessions so incoming packets can be sorted out
114 struct l2tp_tunnel_cfg {
115 int debug; /* bitmask of debug message categories */
116 enum l2tp_encap_type encap;
118 /* Used only for kernel-created sockets */
119 struct in_addr local_ip;
120 struct in_addr peer_ip;
121 #if IS_ENABLED(CONFIG_IPV6)
122 struct in6_addr *local_ip6;
123 struct in6_addr *peer_ip6;
127 unsigned int use_udp_checksums:1,
128 udp6_zero_tx_checksums:1,
129 udp6_zero_rx_checksums:1;
133 int magic; /* Should be L2TP_TUNNEL_MAGIC */
138 rwlock_t hlist_lock; /* protect session_hlist */
139 bool acpt_newsess; /* indicates whether this tunnel accepts
140 * new sessions. Protected by hlist_lock.
142 struct hlist_head session_hlist[L2TP_HASH_SIZE];
143 /* hashed list of sessions, hashed by id */
146 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
148 char name[20]; /* for logging */
149 int debug; /* bitmask of debug message categories */
150 enum l2tp_encap_type encap;
151 struct l2tp_stats stats;
153 struct list_head list; /* list node on per-namespace list of tunnels */
154 struct net *l2tp_net; /* the net we belong to */
156 refcount_t ref_count;
157 void (*old_sk_destruct)(struct sock *sk);
158 struct sock *sock; /* parent socket */
159 int fd; /* parent fd, if tunnel socket was created
163 struct work_struct del_work;
166 struct l2tp_nl_cmd_ops {
167 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
168 u32 session_id, u32 peer_session_id,
169 struct l2tp_session_cfg *cfg);
170 int (*session_delete)(struct l2tp_session *session);
173 static inline void *l2tp_session_priv(struct l2tp_session *session)
175 return &session->priv[0];
178 struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
179 struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
180 struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel,
183 void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
185 struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id);
186 struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
187 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
190 int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
191 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
192 struct l2tp_tunnel **tunnelp);
193 int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
194 struct l2tp_tunnel_cfg *cfg);
196 void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
197 struct l2tp_session *l2tp_session_create(int priv_size,
198 struct l2tp_tunnel *tunnel,
199 u32 session_id, u32 peer_session_id,
200 struct l2tp_session_cfg *cfg);
201 int l2tp_session_register(struct l2tp_session *session,
202 struct l2tp_tunnel *tunnel);
204 void __l2tp_session_unhash(struct l2tp_session *session);
205 int l2tp_session_delete(struct l2tp_session *session);
206 void l2tp_session_free(struct l2tp_session *session);
207 void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
208 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
210 int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
211 void l2tp_session_set_header_len(struct l2tp_session *session, int version);
213 int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb,
216 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type,
217 const struct l2tp_nl_cmd_ops *ops);
218 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
219 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
221 static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
223 refcount_inc(&tunnel->ref_count);
226 static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
228 if (refcount_dec_and_test(&tunnel->ref_count))
229 l2tp_tunnel_free(tunnel);
232 /* Session reference counts. Incremented when code obtains a reference
235 static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
237 refcount_inc(&session->ref_count);
240 static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
242 if (refcount_dec_and_test(&session->ref_count))
243 l2tp_session_free(session);
246 static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
248 switch (session->l2specific_type) {
249 case L2TP_L2SPECTYPE_DEFAULT:
251 case L2TP_L2SPECTYPE_NONE:
257 static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
259 struct dst_entry *dst;
262 dst = sk_dst_get(tunnel->sock);
273 static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
275 struct sock *sk = tunnel->sock;
277 return sk && (rcu_access_pointer(sk->sk_policy[0]) ||
278 rcu_access_pointer(sk->sk_policy[1]));
281 static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
287 static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
288 unsigned char **ptr, unsigned char **optr)
290 int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
293 int off = *ptr - *optr;
295 if (!pskb_may_pull(skb, off + opt_len))
298 if (skb->data != *optr) {
300 *ptr = skb->data + off;
307 #define l2tp_printk(ptr, type, func, fmt, ...) \
309 if (((ptr)->debug) & (type)) \
310 func(fmt, ##__VA_ARGS__); \
313 #define l2tp_warn(ptr, type, fmt, ...) \
314 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
315 #define l2tp_info(ptr, type, fmt, ...) \
316 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
317 #define l2tp_dbg(ptr, type, fmt, ...) \
318 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
320 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
321 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
323 #endif /* _L2TP_CORE_H_ */