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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
18/* Per tunnel, session hash table size */
19#define L2TP_HASH_BITS 4
20#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
21
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
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;
47 u64 rx_cookie_discards;
48 struct u64_stats_sync syncp;
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 {
57 enum l2tp_pwtype pw_type;
58 unsigned int data_seq:2; /* data sequencing level
59 * 0 => none, 1 => IP only,
60 * 2 => all
61 */
62 unsigned int recv_seq:1; /* expect receive packets with
63 * sequence numbers? */
64 unsigned int send_seq:1; /* send packets with sequence
65 * numbers? */
66 unsigned int lns_mode:1; /* behave as LNS? LAC enables
67 * sequence numbers under
68 * control of LNS. */
69 int debug; /* bitmask of debug message
70 * categories */
71 u16 vlan_id; /* VLAN pseudowire only */
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 */
79 int reorder_timeout; /* configured reorder timeout
80 * (in jiffies) */
81 int mtu;
82 int mru;
83 char *ifname;
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;
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) */
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 */
110 char ifname[IFNAMSIZ];
111 unsigned int data_seq:2; /* data sequencing level
112 * 0 => none, 1 => IP only,
113 * 2 => all
114 */
115 unsigned int recv_seq:1; /* expect receive packets with
116 * sequence numbers? */
117 unsigned int send_seq:1; /* send packets with sequence
118 * numbers? */
119 unsigned int lns_mode:1; /* behave as LNS? LAC enables
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) */
126 int reorder_skip; /* set if skip to next nr */
127 int mtu;
128 int mru;
129 enum l2tp_pwtype pwtype;
130 struct l2tp_stats stats;
131 struct hlist_node global_hlist; /* Global hash list node */
132
133 int (*build_header)(struct l2tp_session *session, void *buf);
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);
138#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
139 void (*show)(struct seq_file *m, void *priv);
140#endif
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 */
150 enum l2tp_encap_type encap;
151
152 /* Used only for kernel-created sockets */
153 struct in_addr local_ip;
154 struct in_addr peer_ip;
155#if IS_ENABLED(CONFIG_IPV6)
156 struct in6_addr *local_ip6;
157 struct in6_addr *peer_ip6;
158#endif
159 u16 local_udp_port;
160 u16 peer_udp_port;
161 unsigned int use_udp_checksums:1;
162};
163
164struct l2tp_tunnel {
165 int magic; /* Should be L2TP_TUNNEL_MAGIC */
166 struct rcu_head rcu;
167 rwlock_t hlist_lock; /* protect session_hlist */
168 struct hlist_head session_hlist[L2TP_HASH_SIZE];
169 /* hashed list of sessions,
170 * hashed by id */
171 u32 tunnel_id;
172 u32 peer_tunnel_id;
173 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
174
175 char name[20]; /* for logging */
176 int debug; /* bitmask of debug message
177 * categories */
178 enum l2tp_encap_type encap;
179 struct l2tp_stats stats;
180
181 struct list_head list; /* Keep a list of all tunnels */
182 struct net *l2tp_net; /* the net we belong to */
183
184 atomic_t ref_count;
185#ifdef CONFIG_DEBUG_FS
186 void (*show)(struct seq_file *m, void *arg);
187#endif
188 int (*recv_payload_hook)(struct sk_buff *skb);
189 void (*old_sk_destruct)(struct sock *);
190 struct sock *sock; /* Parent socket */
191 int fd;
192
193 uint8_t priv[0]; /* private data */
194};
195
196struct l2tp_nl_cmd_ops {
197 int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
198 int (*session_delete)(struct l2tp_session *session);
199};
200
201static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel)
202{
203 return &tunnel->priv[0];
204}
205
206static inline void *l2tp_session_priv(struct l2tp_session *session)
207{
208 return &session->priv[0];
209}
210
211static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
212{
213 struct l2tp_tunnel *tunnel;
214
215 if (sk == NULL)
216 return NULL;
217
218 sock_hold(sk);
219 tunnel = (struct l2tp_tunnel *)(sk->sk_user_data);
220 if (tunnel == NULL) {
221 sock_put(sk);
222 goto out;
223 }
224
225 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
226
227out:
228 return tunnel;
229}
230
231extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
232extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
233extern struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname);
234extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
235extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
236
237extern 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);
238extern int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
239extern 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);
240extern int l2tp_session_delete(struct l2tp_session *session);
241extern void l2tp_session_free(struct l2tp_session *session);
242extern 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));
243extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
244
245extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
246
247extern int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
248extern void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
249
250/* Session reference counts. Incremented when code obtains a reference
251 * to a session.
252 */
253static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session)
254{
255 atomic_inc(&session->ref_count);
256}
257
258static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session)
259{
260 if (atomic_dec_and_test(&session->ref_count))
261 l2tp_session_free(session);
262}
263
264#ifdef L2TP_REFCNT_DEBUG
265#define l2tp_session_inc_refcount(_s) \
266do { \
267 pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \
268 __func__, __LINE__, (_s)->name, \
269 atomic_read(&_s->ref_count)); \
270 l2tp_session_inc_refcount_1(_s); \
271} while (0)
272#define l2tp_session_dec_refcount(_s) \
273do { \
274 pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \
275 __func__, __LINE__, (_s)->name, \
276 atomic_read(&_s->ref_count)); \
277 l2tp_session_dec_refcount_1(_s); \
278} while (0)
279#else
280#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s)
281#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s)
282#endif
283
284#define l2tp_printk(ptr, type, func, fmt, ...) \
285do { \
286 if (((ptr)->debug) & (type)) \
287 func(fmt, ##__VA_ARGS__); \
288} while (0)
289
290#define l2tp_warn(ptr, type, fmt, ...) \
291 l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
292#define l2tp_info(ptr, type, fmt, ...) \
293 l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
294#define l2tp_dbg(ptr, type, fmt, ...) \
295 l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
296
297#endif /* _L2TP_CORE_H_ */
1/* SPDX-License-Identifier: GPL-2.0-only */
2/* L2TP internal definitions.
3 *
4 * Copyright (c) 2008,2009 Katalix Systems Ltd
5 */
6#include <linux/refcount.h>
7
8#ifndef _L2TP_CORE_H_
9#define _L2TP_CORE_H_
10
11#include <net/dst.h>
12#include <net/sock.h>
13
14#ifdef CONFIG_XFRM
15#include <net/xfrm.h>
16#endif
17
18/* Random numbers used for internal consistency checks of tunnel and session structures */
19#define L2TP_TUNNEL_MAGIC 0x42114DDA
20#define L2TP_SESSION_MAGIC 0x0C04EB7D
21
22/* Per tunnel session hash table size */
23#define L2TP_HASH_BITS 4
24#define L2TP_HASH_SIZE BIT(L2TP_HASH_BITS)
25
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)
29
30struct sk_buff;
31
32struct l2tp_stats {
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;
42 atomic_long_t rx_invalid;
43};
44
45struct l2tp_tunnel;
46
47/* L2TP session configuration */
48struct l2tp_session_cfg {
49 enum l2tp_pwtype pw_type;
50 unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */
51 unsigned int send_seq:1; /* send packets with sequence numbers? */
52 unsigned int lns_mode:1; /* behave as LNS?
53 * LAC enables sequence numbers under LNS control.
54 */
55 u16 l2specific_type; /* Layer 2 specific type */
56 u8 cookie[8]; /* optional cookie */
57 int cookie_len; /* 0, 4 or 8 bytes */
58 u8 peer_cookie[8]; /* peer's cookie */
59 int peer_cookie_len; /* 0, 4 or 8 bytes */
60 int reorder_timeout; /* configured reorder timeout (in jiffies) */
61 char *ifname;
62};
63
64/* Represents a session (pseudowire) instance.
65 * Tracks runtime state including cookies, dataplane packet sequencing, and IO statistics.
66 * Is linked into a per-tunnel session hashlist; and in the case of an L2TPv3 session into
67 * an additional per-net ("global") hashlist.
68 */
69#define L2TP_SESSION_NAME_MAX 32
70struct l2tp_session {
71 int magic; /* should be L2TP_SESSION_MAGIC */
72 long dead;
73
74 struct l2tp_tunnel *tunnel; /* back pointer to tunnel context */
75 u32 session_id;
76 u32 peer_session_id;
77 u8 cookie[8];
78 int cookie_len;
79 u8 peer_cookie[8];
80 int peer_cookie_len;
81 u16 l2specific_type;
82 u16 hdr_len;
83 u32 nr; /* session NR state (receive) */
84 u32 ns; /* session NR state (send) */
85 struct sk_buff_head reorder_q; /* receive reorder queue */
86 u32 nr_max; /* max NR. Depends on tunnel */
87 u32 nr_window_size; /* NR window size */
88 u32 nr_oos; /* NR of last OOS packet */
89 int nr_oos_count; /* for OOS recovery */
90 int nr_oos_count_max;
91 struct hlist_node hlist; /* hash list node */
92 refcount_t ref_count;
93
94 char name[L2TP_SESSION_NAME_MAX]; /* for logging */
95 char ifname[IFNAMSIZ];
96 unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */
97 unsigned int send_seq:1; /* send packets with sequence numbers? */
98 unsigned int lns_mode:1; /* behave as LNS?
99 * LAC enables sequence numbers under LNS control.
100 */
101 int reorder_timeout; /* configured reorder timeout (in jiffies) */
102 int reorder_skip; /* set if skip to next nr */
103 enum l2tp_pwtype pwtype;
104 struct l2tp_stats stats;
105 struct hlist_node global_hlist; /* global hash list node */
106
107 /* Session receive handler for data packets.
108 * Each pseudowire implementation should implement this callback in order to
109 * handle incoming packets. Packets are passed to the pseudowire handler after
110 * reordering, if data sequence numbers are enabled for the session.
111 */
112 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
113
114 /* Session close handler.
115 * Each pseudowire implementation may implement this callback in order to carry
116 * out pseudowire-specific shutdown actions.
117 * The callback is called by core after unhashing the session and purging its
118 * reorder queue.
119 */
120 void (*session_close)(struct l2tp_session *session);
121
122 /* Session show handler.
123 * Pseudowire-specific implementation of debugfs session rendering.
124 * The callback is called by l2tp_debugfs.c after rendering core session
125 * information.
126 */
127 void (*show)(struct seq_file *m, void *priv);
128
129 u8 priv[]; /* private data */
130};
131
132/* L2TP tunnel configuration */
133struct l2tp_tunnel_cfg {
134 enum l2tp_encap_type encap;
135
136 /* Used only for kernel-created sockets */
137 struct in_addr local_ip;
138 struct in_addr peer_ip;
139#if IS_ENABLED(CONFIG_IPV6)
140 struct in6_addr *local_ip6;
141 struct in6_addr *peer_ip6;
142#endif
143 u16 local_udp_port;
144 u16 peer_udp_port;
145 unsigned int use_udp_checksums:1,
146 udp6_zero_tx_checksums:1,
147 udp6_zero_rx_checksums:1;
148};
149
150/* Represents a tunnel instance.
151 * Tracks runtime state including IO statistics.
152 * Holds the tunnel socket (either passed from userspace or directly created by the kernel).
153 * Maintains a hashlist of sessions belonging to the tunnel instance.
154 * Is linked into a per-net list of tunnels.
155 */
156#define L2TP_TUNNEL_NAME_MAX 20
157struct l2tp_tunnel {
158 int magic; /* Should be L2TP_TUNNEL_MAGIC */
159
160 unsigned long dead;
161
162 struct rcu_head rcu;
163 spinlock_t hlist_lock; /* write-protection for session_hlist */
164 bool acpt_newsess; /* indicates whether this tunnel accepts
165 * new sessions. Protected by hlist_lock.
166 */
167 struct hlist_head session_hlist[L2TP_HASH_SIZE];
168 /* hashed list of sessions, hashed by id */
169 u32 tunnel_id;
170 u32 peer_tunnel_id;
171 int version; /* 2=>L2TPv2, 3=>L2TPv3 */
172
173 char name[L2TP_TUNNEL_NAME_MAX]; /* for logging */
174 enum l2tp_encap_type encap;
175 struct l2tp_stats stats;
176
177 struct list_head list; /* list node on per-namespace list of tunnels */
178 struct net *l2tp_net; /* the net we belong to */
179
180 refcount_t ref_count;
181 void (*old_sk_destruct)(struct sock *sk);
182 struct sock *sock; /* parent socket */
183 int fd; /* parent fd, if tunnel socket was created
184 * by userspace
185 */
186
187 struct work_struct del_work;
188};
189
190/* Pseudowire ops callbacks for use with the l2tp genetlink interface */
191struct l2tp_nl_cmd_ops {
192 /* The pseudowire session create callback is responsible for creating a session
193 * instance for a specific pseudowire type.
194 * It must call l2tp_session_create and l2tp_session_register to register the
195 * session instance, as well as carry out any pseudowire-specific initialisation.
196 * It must return >= 0 on success, or an appropriate negative errno value on failure.
197 */
198 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
199 u32 session_id, u32 peer_session_id,
200 struct l2tp_session_cfg *cfg);
201
202 /* The pseudowire session delete callback is responsible for initiating the deletion
203 * of a session instance.
204 * It must call l2tp_session_delete, as well as carry out any pseudowire-specific
205 * teardown actions.
206 */
207 void (*session_delete)(struct l2tp_session *session);
208};
209
210static inline void *l2tp_session_priv(struct l2tp_session *session)
211{
212 return &session->priv[0];
213}
214
215/* Tunnel and session refcounts */
216void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel);
217void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel);
218void l2tp_session_inc_refcount(struct l2tp_session *session);
219void l2tp_session_dec_refcount(struct l2tp_session *session);
220
221/* Tunnel and session lookup.
222 * These functions take a reference on the instances they return, so
223 * the caller must ensure that the reference is dropped appropriately.
224 */
225struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
226struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
227struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel,
228 u32 session_id);
229
230struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id);
231struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
232struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
233 const char *ifname);
234
235/* Tunnel and session lifetime management.
236 * Creation of a new instance is a two-step process: create, then register.
237 * Destruction is triggered using the *_delete functions, and completes asynchronously.
238 */
239int l2tp_tunnel_create(int fd, int version, u32 tunnel_id,
240 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
241 struct l2tp_tunnel **tunnelp);
242int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
243 struct l2tp_tunnel_cfg *cfg);
244void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
245
246struct l2tp_session *l2tp_session_create(int priv_size,
247 struct l2tp_tunnel *tunnel,
248 u32 session_id, u32 peer_session_id,
249 struct l2tp_session_cfg *cfg);
250int l2tp_session_register(struct l2tp_session *session,
251 struct l2tp_tunnel *tunnel);
252void l2tp_session_delete(struct l2tp_session *session);
253
254/* Receive path helpers. If data sequencing is enabled for the session these
255 * functions handle queuing and reordering prior to passing packets to the
256 * pseudowire code to be passed to userspace.
257 */
258void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
259 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
260 int length);
261int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
262
263/* Transmit path helpers for sending packets over the tunnel socket. */
264void l2tp_session_set_header_len(struct l2tp_session *session, int version);
265int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb);
266
267/* Pseudowire management.
268 * Pseudowires should register with l2tp core on module init, and unregister
269 * on module exit.
270 */
271int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
272void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
273
274/* IOCTL helper for IP encap modules. */
275int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
276
277/* Extract the tunnel structure from a socket's sk_user_data pointer,
278 * validating the tunnel magic feather.
279 */
280struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk);
281
282static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
283{
284 switch (session->l2specific_type) {
285 case L2TP_L2SPECTYPE_DEFAULT:
286 return 4;
287 case L2TP_L2SPECTYPE_NONE:
288 default:
289 return 0;
290 }
291}
292
293static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
294{
295 struct dst_entry *dst;
296 u32 mtu;
297
298 dst = sk_dst_get(tunnel->sock);
299 if (!dst)
300 return 0;
301
302 mtu = dst_mtu(dst);
303 dst_release(dst);
304
305 return mtu;
306}
307
308#ifdef CONFIG_XFRM
309static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
310{
311 struct sock *sk = tunnel->sock;
312
313 return sk && (rcu_access_pointer(sk->sk_policy[0]) ||
314 rcu_access_pointer(sk->sk_policy[1]));
315}
316#else
317static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
318{
319 return false;
320}
321#endif
322
323static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
324 unsigned char **ptr, unsigned char **optr)
325{
326 int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
327
328 if (opt_len > 0) {
329 int off = *ptr - *optr;
330
331 if (!pskb_may_pull(skb, off + opt_len))
332 return -1;
333
334 if (skb->data != *optr) {
335 *optr = skb->data;
336 *ptr = skb->data + off;
337 }
338 }
339
340 return 0;
341}
342
343#define MODULE_ALIAS_L2TP_PWTYPE(type) \
344 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
345
346#endif /* _L2TP_CORE_H_ */