d10901ec53ca920e69517fad2aba6765bc027b25
[strongswan.git] / src / charon / sa / ike_sa_manager.h
1 /*
2 * Copyright (C) 2008 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * 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 * $Id$
18 */
19
20 /**
21 * @defgroup ike_sa_manager ike_sa_manager
22 * @{ @ingroup sa
23 */
24
25 #ifndef IKE_SA_MANAGER_H_
26 #define IKE_SA_MANAGER_H_
27
28 typedef struct ike_sa_manager_t ike_sa_manager_t;
29
30 #include <library.h>
31 #include <sa/ike_sa.h>
32 #include <encoding/message.h>
33 #include <config/peer_cfg.h>
34
35 /**
36 * Manages and synchronizes access to all IKE_SAs.
37 *
38 * To synchronize access to thread-unsave IKE_SAs, they are checked out for
39 * use and checked in afterwards. A checked out SA is exclusively accessible
40 * by the owning thread.
41 */
42 struct ike_sa_manager_t {
43
44 /**
45 * Checkout an existing IKE_SA.
46 *
47 * @param ike_sa_id the SA identifier, will be updated
48 * @returns
49 * - checked out IKE_SA if found
50 * - NULL, if specified IKE_SA is not found.
51 */
52 ike_sa_t* (*checkout) (ike_sa_manager_t* this, ike_sa_id_t *sa_id);
53
54 /**
55 * Create and check out a new IKE_SA.
56 *
57 * @param initiator TRUE for initiator, FALSE otherwise
58 * @returns created and checked out IKE_SA
59 */
60 ike_sa_t* (*checkout_new) (ike_sa_manager_t* this, bool initiator);
61
62 /**
63 * Checkout an IKE_SA by a message.
64 *
65 * In some situations, it is necessary that the manager knows the
66 * message to use for the checkout. This has the following reasons:
67 *
68 * 1. If the targeted IKE_SA is already processing a message, we do not
69 * check it out if the message ID is the same.
70 * 2. If it is an IKE_SA_INIT request, we have to check if it is a
71 * retransmission. If so, we have to drop the message, we would
72 * create another unneeded IKE_SA for each retransmitted packet.
73 *
74 * A call to checkout_by_message() returns a (maybe new created) IKE_SA.
75 * If processing the message does not make sense (for the reasons above),
76 * NULL is returned.
77 *
78 * @param ike_sa_id the SA identifier, will be updated
79 * @returns
80 * - checked out/created IKE_SA
81 * - NULL to not process message further
82 */
83 ike_sa_t* (*checkout_by_message) (ike_sa_manager_t* this, message_t *message);
84
85 /**
86 * Checkout an IKE_SA for initiation by a peer_config.
87 *
88 * To initiate, a CHILD_SA may be established within an existing IKE_SA.
89 * This call checks for an existing IKE_SA by comparing the configuration.
90 * If the CHILD_SA can be created in an existing IKE_SA, the matching SA
91 * is returned.
92 * If no IKE_SA is found, a new one is created. This is also the case when
93 * the found IKE_SA is in the DELETING state.
94 *
95 * @param peer_cfg configuration used to find an existing IKE_SA
96 * @return checked out/created IKE_SA
97 */
98 ike_sa_t* (*checkout_by_config) (ike_sa_manager_t* this,
99 peer_cfg_t *peer_cfg);
100
101 /**
102 * Check for duplicates of the given IKE_SA.
103 *
104 * Measures are taken according to the uniqueness policy of the IKE_SA.
105 * The return value indicates whether duplicates have been found and if
106 * further measures should be taken (e.g. cancelling an IKE_AUTH exchange).
107 * check_uniqueness() must be called before the IKE_SA is complete,
108 * deadlocks occur otherwise.
109 *
110 * @param ike_sa ike_sa to check
111 * @return TRUE, if the given IKE_SA has duplicates and
112 * should be deleted
113 */
114 bool (*check_uniqueness)(ike_sa_manager_t *this, ike_sa_t *ike_sa);
115
116 /**
117 * Check out an IKE_SA a unique ID.
118 *
119 * Every IKE_SA and every CHILD_SA is uniquely identified by an ID.
120 * These checkout function uses, depending
121 * on the child parameter, the unique ID of the IKE_SA or the reqid
122 * of one of a IKE_SAs CHILD_SA.
123 *
124 * @param id unique ID of the object
125 * @param child TRUE to use CHILD, FALSE to use IKE_SA
126 * @return
127 * - checked out IKE_SA, if found
128 * - NULL, if not found
129 */
130 ike_sa_t* (*checkout_by_id) (ike_sa_manager_t* this, u_int32_t id,
131 bool child);
132
133 /**
134 * Check out an IKE_SA by the policy/connection name.
135 *
136 * Check out the IKE_SA by the configuration name, either from the IKE- or
137 * one of its CHILD_SAs.
138 *
139 * @param name name of the connection/policy
140 * @param child TRUE to use policy name, FALSE to use conn name
141 * @return
142 * - checked out IKE_SA, if found
143 * - NULL, if not found
144 */
145 ike_sa_t* (*checkout_by_name) (ike_sa_manager_t* this, char *name,
146 bool child);
147
148 /**
149 * Create an enumerator over all stored IKE_SAs.
150 *
151 * While enumerating an IKE_SA, it is temporarily checked out and
152 * automatically checked in after the current enumeration step.
153 *
154 * @return enumerator over all IKE_SAs.
155 */
156 enumerator_t *(*create_enumerator) (ike_sa_manager_t* this);
157
158 /**
159 * Checkin the SA after usage.
160 *
161 * If the IKE_SA is not registered in the manager, a new entry is created.
162 *
163 * @param ike_sa_id the SA identifier, will be updated
164 * @param ike_sa checked out SA
165 */
166 void (*checkin) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
167
168 /**
169 * Destroy a checked out SA.
170 *
171 * The IKE SA is destroyed without notification of the remote peer.
172 * Use this only if the other peer doesn't respond or behaves not
173 * as predicted.
174 * Checking in and destruction is an atomic operation (for the IKE_SA),
175 * so this can be called if the SA is in a "unclean" state, without the
176 * risk that another thread can get the SA.
177 *
178 * @param ike_sa SA to delete
179 */
180 void (*checkin_and_destroy) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
181
182 /**
183 * Get the number of IKE_SAs which are in the connecting state.
184 *
185 * To prevent the server from resource exhaustion, cookies and other
186 * mechanisms are used. The number of half open IKE_SAs is a good
187 * indicator to see if a peer is flooding the server.
188 * If a host is supplied, only the number of half open IKE_SAs initiated
189 * from this IP are counted.
190 * Only SAs for which we are the responder are counted.
191 *
192 * @param ip NULL for all, IP for half open IKE_SAs with IP
193 * @return number of half open IKE_SAs
194 */
195 int (*get_half_open_count) (ike_sa_manager_t *this, host_t *ip);
196
197 /**
198 * Delete all existing IKE_SAs and destroy them immediately.
199 *
200 * Threads will be driven out, so all SAs can be deleted cleanly.
201 */
202 void (*flush)(ike_sa_manager_t *this);
203
204 /**
205 * Destroys the manager with all associated SAs.
206 *
207 * A call to flush() is required before calling destroy.
208 */
209 void (*destroy) (ike_sa_manager_t *this);
210 };
211
212 /**
213 * Create the IKE_SA manager.
214 *
215 * @returns ike_sa_manager_t object, NULL if initialization fails
216 */
217 ike_sa_manager_t *ike_sa_manager_create(void);
218
219 #endif /*IKE_SA_MANAGER_H_ @} */