Remove policies in kernel interfaces based on their priority.
[strongswan.git] / src / libhydra / kernel / kernel_interface.h
1 /*
2 * Copyright (C) 2006-2011 Tobias Brunner
3 * Copyright (C) 2006 Daniel Roethlisberger
4 * Copyright (C) 2005-2006 Martin Willi
5 * Copyright (C) 2005 Jan Hutter
6 * Hochschule fuer Technik Rapperswil
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 * for more details.
17 */
18
19 /**
20 * @defgroup kernel_interface kernel_interface
21 * @{ @ingroup hkernel
22 */
23
24 #ifndef KERNEL_INTERFACE_H_
25 #define KERNEL_INTERFACE_H_
26
27 typedef struct kernel_interface_t kernel_interface_t;
28
29 #include <utils/host.h>
30 #include <crypto/prf_plus.h>
31
32 #include <kernel/kernel_listener.h>
33 #include <kernel/kernel_ipsec.h>
34 #include <kernel/kernel_net.h>
35
36 /**
37 * Constructor function for ipsec kernel interface
38 */
39 typedef kernel_ipsec_t* (*kernel_ipsec_constructor_t)(void);
40
41 /**
42 * Constructor function for network kernel interface
43 */
44 typedef kernel_net_t* (*kernel_net_constructor_t)(void);
45
46 /**
47 * Manager and wrapper for different kernel interfaces.
48 *
49 * The kernel interface handles the communication with the kernel
50 * for SA and policy management and interface and IP address management.
51 */
52 struct kernel_interface_t {
53
54 /**
55 * Get a SPI from the kernel.
56 *
57 * @param src source address of SA
58 * @param dst destination address of SA
59 * @param protocol protocol for SA (ESP/AH)
60 * @param reqid unique ID for this SA
61 * @param spi allocated spi
62 * @return SUCCESS if operation completed
63 */
64 status_t (*get_spi)(kernel_interface_t *this, host_t *src, host_t *dst,
65 u_int8_t protocol, u_int32_t reqid, u_int32_t *spi);
66
67 /**
68 * Get a Compression Parameter Index (CPI) from the kernel.
69 *
70 * @param src source address of SA
71 * @param dst destination address of SA
72 * @param reqid unique ID for the corresponding SA
73 * @param cpi allocated cpi
74 * @return SUCCESS if operation completed
75 */
76 status_t (*get_cpi)(kernel_interface_t *this, host_t *src, host_t *dst,
77 u_int32_t reqid, u_int16_t *cpi);
78
79 /**
80 * Add an SA to the SAD.
81 *
82 * add_sa() may update an already allocated
83 * SPI (via get_spi). In this case, the replace
84 * flag must be set.
85 * This function does install a single SA for a
86 * single protocol in one direction.
87 *
88 * @param src source address for this SA
89 * @param dst destination address for this SA
90 * @param spi SPI allocated by us or remote peer
91 * @param protocol protocol for this SA (ESP/AH)
92 * @param reqid unique ID for this SA
93 * @param mark optional mark for this SA
94 * @param tfc Traffic Flow Confidentiality padding for this SA
95 * @param lifetime lifetime_cfg_t for this SA
96 * @param enc_alg Algorithm to use for encryption (ESP only)
97 * @param enc_key key to use for encryption
98 * @param int_alg Algorithm to use for integrity protection
99 * @param int_key key to use for integrity protection
100 * @param mode mode of the SA (tunnel, transport)
101 * @param ipcomp IPComp transform to use
102 * @param cpi CPI for IPComp
103 * @param encap enable UDP encapsulation for NAT traversal
104 * @param esn TRUE to use Extended Sequence Numbers
105 * @param inbound TRUE if this is an inbound SA
106 * @param src_ts traffic selector with BEET source address
107 * @param dst_ts traffic selector with BEET destination address
108 * @return SUCCESS if operation completed
109 */
110 status_t (*add_sa) (kernel_interface_t *this,
111 host_t *src, host_t *dst, u_int32_t spi,
112 u_int8_t protocol, u_int32_t reqid, mark_t mark,
113 u_int32_t tfc, lifetime_cfg_t *lifetime,
114 u_int16_t enc_alg, chunk_t enc_key,
115 u_int16_t int_alg, chunk_t int_key,
116 ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi,
117 bool encap, bool esn, bool inbound,
118 traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
119
120 /**
121 * Update the hosts on an installed SA.
122 *
123 * We cannot directly update the destination address as the kernel
124 * requires the spi, the protocol AND the destination address (and family)
125 * to identify SAs. Therefore if the destination address changed we
126 * create a new SA and delete the old one.
127 *
128 * @param spi SPI of the SA
129 * @param protocol protocol for this SA (ESP/AH)
130 * @param cpi CPI for IPComp, 0 if no IPComp is used
131 * @param src current source address
132 * @param dst current destination address
133 * @param new_src new source address
134 * @param new_dst new destination address
135 * @param encap current use of UDP encapsulation
136 * @param new_encap new use of UDP encapsulation
137 * @param mark optional mark for this SA
138 * @return SUCCESS if operation completed, NOT_SUPPORTED if
139 * the kernel interface can't update the SA
140 */
141 status_t (*update_sa)(kernel_interface_t *this,
142 u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
143 host_t *src, host_t *dst,
144 host_t *new_src, host_t *new_dst,
145 bool encap, bool new_encap, mark_t mark);
146
147 /**
148 * Query the number of bytes processed by an SA from the SAD.
149 *
150 * @param src source address for this SA
151 * @param dst destination address for this SA
152 * @param spi SPI allocated by us or remote peer
153 * @param protocol protocol for this SA (ESP/AH)
154 * @param mark optional mark for this SA
155 * @param[out] bytes the number of bytes processed by SA
156 * @return SUCCESS if operation completed
157 */
158 status_t (*query_sa) (kernel_interface_t *this, host_t *src, host_t *dst,
159 u_int32_t spi, u_int8_t protocol, mark_t mark,
160 u_int64_t *bytes);
161
162 /**
163 * Delete a previously installed SA from the SAD.
164 *
165 * @param src source address for this SA
166 * @param dst destination address for this SA
167 * @param spi SPI allocated by us or remote peer
168 * @param protocol protocol for this SA (ESP/AH)
169 * @param cpi CPI for IPComp or 0
170 * @param mark optional mark for this SA
171 * @return SUCCESS if operation completed
172 */
173 status_t (*del_sa) (kernel_interface_t *this, host_t *src, host_t *dst,
174 u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
175 mark_t mark);
176
177 /**
178 * Add a policy to the SPD.
179 *
180 * A policy is always associated to an SA. Traffic which matches a
181 * policy is handled by the SA with the same reqid.
182 *
183 * @param src source address of SA
184 * @param dst dest address of SA
185 * @param src_ts traffic selector to match traffic source
186 * @param dst_ts traffic selector to match traffic dest
187 * @param direction direction of traffic, POLICY_(IN|OUT|FWD)
188 * @param type type of policy, POLICY_(IPSEC|PASS|DROP)
189 * @param sa details about the SA(s) tied to this policy
190 * @param mark mark for this policy
191 * @param priority priority of this policy
192 * @return SUCCESS if operation completed
193 */
194 status_t (*add_policy) (kernel_interface_t *this,
195 host_t *src, host_t *dst,
196 traffic_selector_t *src_ts,
197 traffic_selector_t *dst_ts,
198 policy_dir_t direction, policy_type_t type,
199 ipsec_sa_cfg_t *sa, mark_t mark,
200 policy_priority_t priority);
201
202 /**
203 * Query the use time of a policy.
204 *
205 * The use time of a policy is the time the policy was used
206 * for the last time.
207 *
208 * @param src_ts traffic selector to match traffic source
209 * @param dst_ts traffic selector to match traffic dest
210 * @param direction direction of traffic, POLICY_(IN|OUT|FWD)
211 * @param mark optional mark
212 * @param[out] use_time the time of this SA's last use
213 * @return SUCCESS if operation completed
214 */
215 status_t (*query_policy) (kernel_interface_t *this,
216 traffic_selector_t *src_ts,
217 traffic_selector_t *dst_ts,
218 policy_dir_t direction, mark_t mark,
219 u_int32_t *use_time);
220
221 /**
222 * Remove a policy from the SPD.
223 *
224 * The kernel interface implements reference counting for policies.
225 * If the same policy is installed multiple times (in the case of rekeying),
226 * the reference counter is increased. del_policy() decreases the ref counter
227 * and removes the policy only when no more references are available.
228 *
229 * @param src_ts traffic selector to match traffic source
230 * @param dst_ts traffic selector to match traffic dest
231 * @param direction direction of traffic, POLICY_(IN|OUT|FWD)
232 * @param reqid unique ID of the associated SA
233 * @param mark optional mark
234 * @param priority priority of the policy
235 * @return SUCCESS if operation completed
236 */
237 status_t (*del_policy) (kernel_interface_t *this,
238 traffic_selector_t *src_ts,
239 traffic_selector_t *dst_ts,
240 policy_dir_t direction, u_int32_t reqid,
241 mark_t mark, policy_priority_t priority);
242
243 /**
244 * Get our outgoing source address for a destination.
245 *
246 * Does a route lookup to get the source address used to reach dest.
247 * The returned host is allocated and must be destroyed.
248 * An optional src address can be used to check if a route is available
249 * for given source to dest.
250 *
251 * @param dest target destination address
252 * @param src source address to check, or NULL
253 * @return outgoing source address, NULL if unreachable
254 */
255 host_t* (*get_source_addr)(kernel_interface_t *this,
256 host_t *dest, host_t *src);
257
258 /**
259 * Get the next hop for a destination.
260 *
261 * Does a route lookup to get the next hop used to reach dest.
262 * The returned host is allocated and must be destroyed.
263 *
264 * @param dest target destination address
265 * @return next hop address, NULL if unreachable
266 */
267 host_t* (*get_nexthop)(kernel_interface_t *this, host_t *dest);
268
269 /**
270 * Get the interface name of a local address.
271 *
272 * @param host address to get interface name from
273 * @return allocated interface name, or NULL if not found
274 */
275 char* (*get_interface) (kernel_interface_t *this, host_t *host);
276
277 /**
278 * Creates an enumerator over all local addresses.
279 *
280 * This function blocks an internal cached address list until the
281 * enumerator gets destroyed.
282 * The hosts are read-only, do not modify of free.
283 *
284 * @param include_down_ifaces TRUE to enumerate addresses from down interfaces
285 * @param include_virtual_ips TRUE to enumerate virtual ip addresses
286 * @return enumerator over host_t's
287 */
288 enumerator_t *(*create_address_enumerator) (kernel_interface_t *this,
289 bool include_down_ifaces, bool include_virtual_ips);
290
291 /**
292 * Add a virtual IP to an interface.
293 *
294 * Virtual IPs are attached to an interface. If an IP is added multiple
295 * times, the IP is refcounted and not removed until del_ip() was called
296 * as many times as add_ip().
297 * The virtual IP is attached to the interface where the iface_ip is found.
298 *
299 * @param virtual_ip virtual ip address to assign
300 * @param iface_ip IP of an interface to attach virtual IP
301 * @return SUCCESS if operation completed
302 */
303 status_t (*add_ip) (kernel_interface_t *this, host_t *virtual_ip,
304 host_t *iface_ip);
305
306 /**
307 * Remove a virtual IP from an interface.
308 *
309 * The kernel interface uses refcounting, see add_ip().
310 *
311 * @param virtual_ip virtual ip address to assign
312 * @return SUCCESS if operation completed
313 */
314 status_t (*del_ip) (kernel_interface_t *this, host_t *virtual_ip);
315
316 /**
317 * Add a route.
318 *
319 * @param dst_net destination net
320 * @param prefixlen destination net prefix length
321 * @param gateway gateway for this route
322 * @param src_ip sourc ip of the route
323 * @param if_name name of the interface the route is bound to
324 * @return SUCCESS if operation completed
325 * ALREADY_DONE if the route already exists
326 */
327 status_t (*add_route) (kernel_interface_t *this, chunk_t dst_net,
328 u_int8_t prefixlen, host_t *gateway, host_t *src_ip,
329 char *if_name);
330
331 /**
332 * Delete a route.
333 *
334 * @param dst_net destination net
335 * @param prefixlen destination net prefix length
336 * @param gateway gateway for this route
337 * @param src_ip sourc ip of the route
338 * @param if_name name of the interface the route is bound to
339 * @return SUCCESS if operation completed
340 */
341 status_t (*del_route) (kernel_interface_t *this, chunk_t dst_net,
342 u_int8_t prefixlen, host_t *gateway, host_t *src_ip,
343 char *if_name);
344
345 /**
346 * Set up a bypass policy for a given socket.
347 *
348 * @param fd socket file descriptor to setup policy for
349 * @param family protocol family of the socket
350 * @return TRUE of policy set up successfully
351 */
352 bool (*bypass_socket)(kernel_interface_t *this, int fd, int family);
353
354 /**
355 * manager methods
356 */
357
358 /**
359 * Tries to find an ip address of a local interface that is included in the
360 * supplied traffic selector.
361 *
362 * @param ts traffic selector
363 * @param ip returned ip (has to be destroyed)
364 * @return SUCCESS if address found
365 */
366 status_t (*get_address_by_ts)(kernel_interface_t *this,
367 traffic_selector_t *ts, host_t **ip);
368
369 /**
370 * Register an ipsec kernel interface constructor on the manager.
371 *
372 * @param create constructor to register
373 */
374 void (*add_ipsec_interface)(kernel_interface_t *this,
375 kernel_ipsec_constructor_t create);
376
377 /**
378 * Unregister an ipsec kernel interface constructor.
379 *
380 * @param create constructor to unregister
381 */
382 void (*remove_ipsec_interface)(kernel_interface_t *this,
383 kernel_ipsec_constructor_t create);
384
385 /**
386 * Register a network kernel interface constructor on the manager.
387 *
388 * @param create constructor to register
389 */
390 void (*add_net_interface)(kernel_interface_t *this,
391 kernel_net_constructor_t create);
392
393 /**
394 * Unregister a network kernel interface constructor.
395 *
396 * @param create constructor to unregister
397 */
398 void (*remove_net_interface)(kernel_interface_t *this,
399 kernel_net_constructor_t create);
400
401 /**
402 * Add a listener to the kernel interface.
403 *
404 * @param listener listener to add
405 */
406 void (*add_listener)(kernel_interface_t *this,
407 kernel_listener_t *listener);
408
409 /**
410 * Remove a listener from the kernel interface.
411 *
412 * @param listener listener to remove
413 */
414 void (*remove_listener)(kernel_interface_t *this,
415 kernel_listener_t *listener);
416
417 /**
418 * Raise an acquire event.
419 *
420 * @param reqid reqid of the policy to acquire
421 * @param src_ts source traffic selector
422 * @param dst_ts destination traffic selector
423 */
424 void (*acquire)(kernel_interface_t *this, u_int32_t reqid,
425 traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
426
427 /**
428 * Raise an expire event.
429 *
430 * @param reqid reqid of the expired SA
431 * @param protocol protocol of the expired SA
432 * @param spi spi of the expired SA
433 * @param hard TRUE if it is a hard expire, FALSE otherwise
434 */
435 void (*expire)(kernel_interface_t *this, u_int32_t reqid,
436 u_int8_t protocol, u_int32_t spi, bool hard);
437
438 /**
439 * Raise a mapping event.
440 *
441 * @param reqid reqid of the SA
442 * @param spi spi of the SA
443 * @param remote new remote host
444 */
445 void (*mapping)(kernel_interface_t *this, u_int32_t reqid, u_int32_t spi,
446 host_t *remote);
447
448 /**
449 * Raise a migrate event.
450 *
451 * @param reqid reqid of the policy
452 * @param src_ts source traffic selector
453 * @param dst_ts destination traffic selector
454 * @param direction direction of the policy (in|out)
455 * @param local local host address to be used in the IKE_SA
456 * @param remote remote host address to be used in the IKE_SA
457 */
458 void (*migrate)(kernel_interface_t *this, u_int32_t reqid,
459 traffic_selector_t *src_ts, traffic_selector_t *dst_ts,
460 policy_dir_t direction, host_t *local, host_t *remote);
461
462 /**
463 * Raise a roam event.
464 *
465 * @param address TRUE if address list, FALSE if routing changed
466 */
467 void (*roam)(kernel_interface_t *this, bool address);
468
469 /**
470 * Destroys a kernel_interface_manager_t object.
471 */
472 void (*destroy) (kernel_interface_t *this);
473 };
474
475 /**
476 * Creates an object of type kernel_interface_t.
477 */
478 kernel_interface_t *kernel_interface_create(void);
479
480 #endif /** KERNEL_INTERFACE_H_ @}*/