5695c9433fbdaefcb91291ccfa3891f58b508433
[strongswan.git] / src / libcharon / sa / ike_sa_manager.h
1 /*
2 * Copyright (C) 2008-2021 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * HSR Hochschule fuer Technik Rapperswil
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 */
17
18 /**
19 * @defgroup ike_sa_manager ike_sa_manager
20 * @{ @ingroup sa
21 */
22
23 #ifndef IKE_SA_MANAGER_H_
24 #define IKE_SA_MANAGER_H_
25
26 typedef struct ike_sa_manager_t ike_sa_manager_t;
27
28 #include <library.h>
29 #include <sa/ike_sa.h>
30 #include <encoding/message.h>
31 #include <config/peer_cfg.h>
32
33 /**
34 * Callback called to generate an IKE SPI.
35 *
36 * This may be called from multiple threads concurrently.
37 *
38 * @param data data supplied during registration of the callback
39 * @return allocated SPI, 0 on failure
40 */
41 typedef uint64_t (*spi_cb_t)(void *data);
42
43 /**
44 * Manages and synchronizes access to all IKE_SAs.
45 *
46 * To synchronize access to thread-unsave IKE_SAs, they are checked out for
47 * use and checked in afterwards. A checked out SA is exclusively accessible
48 * by the owning thread.
49 */
50 struct ike_sa_manager_t {
51
52 /**
53 * Create a new IKE_SA.
54 *
55 * @param version IKE version of this SA
56 * @param initiator TRUE for initiator, FALSE otherwise
57 * @returns created IKE_SA (not registered/checked out)
58 */
59 ike_sa_t *(*create_new)(ike_sa_manager_t* this, ike_version_t version,
60 bool initiator);
61
62 /**
63 * Checkout an existing IKE_SA.
64 *
65 * @param ike_sa_id the SA identifier, will be updated
66 * @returns
67 * - checked out IKE_SA if found
68 * - NULL, if specified IKE_SA is not found.
69 */
70 ike_sa_t* (*checkout) (ike_sa_manager_t* this, ike_sa_id_t *sa_id);
71
72 /**
73 * Checkout an IKE_SA by a message.
74 *
75 * In some situations, it is necessary that the manager knows the
76 * message to use for the checkout. This has the following reasons:
77 *
78 * 1. If the targeted IKE_SA is already processing a message, we do not
79 * check it out if the message ID is the same.
80 * 2. If it is an IKE_SA_INIT request, we have to check if it is a
81 * retransmission. If so, we have to drop the message, we would
82 * create another unneeded IKE_SA for each retransmitted packet.
83 *
84 * A call to checkout_by_message() returns a (maybe new created) IKE_SA.
85 * If processing the message does not make sense (for the reasons above),
86 * NULL is returned.
87 *
88 * @param ike_sa_id the SA identifier, will be updated
89 * @returns
90 * - checked out/created IKE_SA
91 * - NULL to not process message further
92 */
93 ike_sa_t* (*checkout_by_message) (ike_sa_manager_t* this, message_t *message);
94
95 /**
96 * Checkout an IKE_SA for initiation by a peer_config.
97 *
98 * To initiate, a CHILD_SA may be established within an existing IKE_SA.
99 * This call checks for an existing IKE_SA by comparing the configuration.
100 * If the CHILD_SA can be created in an existing IKE_SA, the matching SA
101 * is returned.
102 * If no IKE_SA is found, a new one is created and registered in the
103 * manager. This is also the case when the found IKE_SA is in an unusable
104 * state (e.g. DELETING).
105 *
106 * @note The peer_config is always set on the returned IKE_SA.
107 *
108 * @param peer_cfg configuration used to find an existing IKE_SA
109 * @return checked out/created IKE_SA
110 */
111 ike_sa_t *(*checkout_by_config)(ike_sa_manager_t* this, peer_cfg_t *peer_cfg);
112
113 /**
114 * Reset initiator SPI.
115 *
116 * Allocate a new initiator SPI for the given IKE_SA in state IKE_CONNECTING
117 * and update internal data.
118 *
119 * @param ike_sa IKE_SA to update
120 * @return TRUE if SPI successfully changed
121 */
122 bool (*new_initiator_spi)(ike_sa_manager_t* this, ike_sa_t *ike_sa);
123
124 /**
125 * Check for duplicates of the given IKE_SA.
126 *
127 * Measures are taken according to the uniqueness policy of the IKE_SA.
128 * The return value indicates whether duplicates have been found and if
129 * further measures should be taken (e.g. cancelling an IKE_AUTH exchange).
130 * check_uniqueness() must be called before the IKE_SA is complete,
131 * deadlocks occur otherwise.
132 *
133 * @param ike_sa ike_sa to check
134 * @param force_replace replace existing SAs, regardless of unique policy
135 * @return TRUE, if the given IKE_SA has duplicates and
136 * should be deleted
137 */
138 bool (*check_uniqueness)(ike_sa_manager_t *this, ike_sa_t *ike_sa,
139 bool force_replace);
140
141 /**
142 * Check if we already have a connected IKE_SA between two identities.
143 *
144 * @param me own identity
145 * @param other remote identity
146 * @param family address family to include in uniqueness check
147 * @return TRUE if we have a connected IKE_SA
148 */
149 bool (*has_contact)(ike_sa_manager_t *this, identification_t *me,
150 identification_t *other, int family);
151
152 /**
153 * Check out an IKE_SA a unique ID.
154 *
155 * Every IKE_SA is uniquely identified by a numerical ID. This checkout
156 * function uses the unique ID of the IKE_SA to check it out.
157 *
158 * @param id unique ID of the object
159 * @return
160 * - checked out IKE_SA, if found
161 * - NULL, if not found
162 */
163 ike_sa_t* (*checkout_by_id) (ike_sa_manager_t* this, uint32_t id);
164
165 /**
166 * Check out an IKE_SA by the policy/connection name.
167 *
168 * Check out the IKE_SA by the configuration name, either from the IKE- or
169 * one of its CHILD_SAs.
170 *
171 * @param name name of the connection/policy
172 * @param child TRUE to use policy name, FALSE to use conn name
173 * @return
174 * - checked out IKE_SA, if found
175 * - NULL, if not found
176 */
177 ike_sa_t* (*checkout_by_name) (ike_sa_manager_t* this, char *name,
178 bool child);
179
180 /**
181 * Create an enumerator over all stored IKE_SAs.
182 *
183 * While enumerating an IKE_SA, it is temporarily checked out and
184 * automatically checked in after the current enumeration step.
185 *
186 * @param wait TRUE to wait for checked out SAs, FALSE to skip
187 * @return enumerator over all IKE_SAs.
188 */
189 enumerator_t *(*create_enumerator) (ike_sa_manager_t* this, bool wait);
190
191 /**
192 * Create an enumerator over ike_sa_id_t*, matching peer identities.
193 *
194 * The remote peer is identified by its XAuth or EAP identity, if available.
195 *
196 * @param me local peer identity to match
197 * @param other remote peer identity to match
198 * @param family address family to match, 0 for any
199 * @return enumerator over ike_sa_id_t*
200 */
201 enumerator_t* (*create_id_enumerator)(ike_sa_manager_t *this,
202 identification_t *me, identification_t *other,
203 int family);
204
205 /**
206 * Checkin the SA after usage.
207 *
208 * If the IKE_SA is not registered in the manager, a new entry is created.
209 *
210 * @param ike_sa_id the SA identifier, will be updated
211 * @param ike_sa checked out SA
212 */
213 void (*checkin) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
214
215 /**
216 * Destroy a checked out SA.
217 *
218 * The IKE SA is destroyed without notification of the remote peer.
219 * Use this only if the other peer doesn't respond or behaves not
220 * as predicted.
221 * Checking in and destruction is an atomic operation (for the IKE_SA),
222 * so this can be called if the SA is in a "unclean" state, without the
223 * risk that another thread can get the SA.
224 *
225 * @param ike_sa SA to delete
226 */
227 void (*checkin_and_destroy) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
228
229 /**
230 * Get the number of IKE_SAs currently registered.
231 *
232 * @return number of registered IKE_SAs
233 */
234 u_int (*get_count)(ike_sa_manager_t *this);
235
236 /**
237 * Get the number of IKE_SAs which are in the connecting state.
238 *
239 * To prevent the server from resource exhaustion, cookies and other
240 * mechanisms are used. The number of half open IKE_SAs is a good
241 * indicator to see if a peer is flooding the server.
242 * If a host is supplied, only the number of half open IKE_SAs with this IP
243 * are counted.
244 *
245 * @param ip NULL for all, IP for half open IKE_SAs with IP
246 * @param responder_only TRUE to return only the number of responding SAs
247 * @return number of half open IKE_SAs
248 */
249 u_int (*get_half_open_count)(ike_sa_manager_t *this, host_t *ip,
250 bool responder_only);
251
252 /**
253 * Set the callback to generate IKE SPIs
254 *
255 * @param callback callback to register
256 * @param data data provided to callback
257 */
258 void (*set_spi_cb)(ike_sa_manager_t *this, spi_cb_t callback,
259 void *data);
260
261 /**
262 * Delete all existing IKE_SAs and destroy them immediately.
263 *
264 * Threads will be driven out, so all SAs can be deleted cleanly.
265 * To a flush(), an immediate call to destroy() is mandatory; no other
266 * method may be used.
267 */
268 void (*flush)(ike_sa_manager_t *this);
269
270 /**
271 * Destroys the manager with all associated SAs.
272 *
273 * A call to flush() is required before calling destroy.
274 */
275 void (*destroy) (ike_sa_manager_t *this);
276 };
277
278 /**
279 * Create the IKE_SA manager.
280 *
281 * @returns ike_sa_manager_t object, NULL if initialization fails
282 */
283 ike_sa_manager_t *ike_sa_manager_create(void);
284
285 #endif /** IKE_SA_MANAGER_H_ @}*/