8fa5fb0063e06551041564c429371b888da24214
[strongswan.git] / src / charon / kernel / kernel_ipsec.h
1 /*
2 * Copyright (C) 2006-2008 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 * $Id$
19 */
20
21 /**
22 * @defgroup kernel_ipsec kernel_ipsec
23 * @{ @ingroup kernel
24 */
25
26 #ifndef KERNEL_IPSEC_H_
27 #define KERNEL_IPSEC_H_
28
29 typedef enum ipsec_mode_t ipsec_mode_t;
30 typedef enum policy_dir_t policy_dir_t;
31 typedef struct kernel_ipsec_t kernel_ipsec_t;
32
33 #include <utils/host.h>
34 #include <crypto/prf_plus.h>
35 #include <encoding/payloads/proposal_substructure.h>
36
37 /**
38 * Mode of an CHILD_SA.
39 *
40 * These are equal to those defined in XFRM, so don't change.
41 */
42 enum ipsec_mode_t {
43 /** transport mode, no inner address */
44 MODE_TRANSPORT = 0,
45 /** tunnel mode, inner and outer addresses */
46 MODE_TUNNEL = 1,
47 /** BEET mode, tunnel mode but fixed, bound inner addresses */
48 MODE_BEET = 4,
49 };
50
51 /**
52 * enum names for ipsec_mode_t.
53 */
54 extern enum_name_t *ipsec_mode_names;
55
56 /**
57 * Direction of a policy. These are equal to those
58 * defined in xfrm.h, but we want to stay implementation
59 * neutral here.
60 */
61 enum policy_dir_t {
62 /** Policy for inbound traffic */
63 POLICY_IN = 0,
64 /** Policy for outbound traffic */
65 POLICY_OUT = 1,
66 /** Policy for forwarded traffic */
67 POLICY_FWD = 2,
68 };
69
70 /**
71 * enum names for policy_dir_t.
72 */
73 extern enum_name_t *policy_dir_names;
74
75 /**
76 * Interface to the ipsec subsystem of the kernel.
77 *
78 * The kernel ipsec interface handles the communication with the kernel
79 * for SA and policy management. It allows setup of these, and provides
80 * further the handling of kernel events.
81 * Policy information are cached in the interface. This is necessary to do
82 * reference counting. The Linux kernel does not allow the same policy
83 * installed twice, but we need this as CHILD_SA exist multiple times
84 * when rekeying. Thats why we do reference counting of policies.
85 */
86 struct kernel_ipsec_t {
87
88 /**
89 * Get a SPI from the kernel.
90 *
91 * @warning get_spi() implicitly creates an SA with
92 * the allocated SPI, therefore the replace flag
93 * in add_sa() must be set when installing this SA.
94 *
95 * @param src source address of SA
96 * @param dst destination address of SA
97 * @param protocol protocol for SA (ESP/AH)
98 * @param reqid unique ID for this SA
99 * @param spi allocated spi
100 * @return SUCCESS if operation completed
101 */
102 status_t (*get_spi)(kernel_ipsec_t *this, host_t *src, host_t *dst,
103 protocol_id_t protocol, u_int32_t reqid, u_int32_t *spi);
104
105 /**
106 * Get a Compression Parameter Index (CPI) from the kernel.
107 *
108 * @param src source address of SA
109 * @param dst destination address of SA
110 * @param reqid unique ID for the corresponding SA
111 * @param cpi allocated cpi
112 * @return SUCCESS if operation completed
113 */
114 status_t (*get_cpi)(kernel_ipsec_t *this, host_t *src, host_t *dst,
115 u_int32_t reqid, u_int16_t *cpi);
116
117 /**
118 * Add an SA to the SAD.
119 *
120 * add_sa() may update an already allocated
121 * SPI (via get_spi). In this case, the replace
122 * flag must be set.
123 * This function does install a single SA for a
124 * single protocol in one direction. The kernel-interface
125 * gets the keys itself from the PRF, as we don't know
126 * his algorithms and key sizes.
127 *
128 * @param src source address for this SA
129 * @param dst destination address for this SA
130 * @param spi SPI allocated by us or remote peer
131 * @param protocol protocol for this SA (ESP/AH)
132 * @param reqid unique ID for this SA
133 * @param expire_soft lifetime in seconds before rekeying
134 * @param expire_hard lifetime in seconds before delete
135 * @param enc_alg Algorithm to use for encryption (ESP only)
136 * @param enc_size key length of encryption algorithm, if dynamic
137 * @param int_alg Algorithm to use for integrity protection
138 * @param int_size key length of integrity algorithm, if dynamic
139 * @param prf_plus PRF to derive keys from
140 * @param mode mode of the SA (tunnel, transport)
141 * @param ipcomp IPComp transform to use
142 * @param encap enable UDP encapsulation for NAT traversal
143 * @param replace Should an already installed SA be updated?
144 * @return SUCCESS if operation completed
145 */
146 status_t (*add_sa) (kernel_ipsec_t *this,
147 host_t *src, host_t *dst, u_int32_t spi,
148 protocol_id_t protocol, u_int32_t reqid,
149 u_int64_t expire_soft, u_int64_t expire_hard,
150 u_int16_t enc_alg, u_int16_t enc_size,
151 u_int16_t int_alg, u_int16_t int_size,
152 prf_plus_t *prf_plus, ipsec_mode_t mode,
153 u_int16_t ipcomp, bool encap,
154 bool update);
155
156 /**
157 * Update the hosts on an installed SA.
158 *
159 * We cannot directly update the destination address as the kernel
160 * requires the spi, the protocol AND the destination address (and family)
161 * to identify SAs. Therefore if the destination address changed we
162 * create a new SA and delete the old one.
163 *
164 * @param spi SPI of the SA
165 * @param protocol protocol for this SA (ESP/AH)
166 * @param src current source address
167 * @param dst current destination address
168 * @param new_src new source address
169 * @param new_dst new destination address
170 * @param encap use UDP encapsulation
171 * @return SUCCESS if operation completed
172 */
173 status_t (*update_sa)(kernel_ipsec_t *this,
174 u_int32_t spi, protocol_id_t protocol,
175 host_t *src, host_t *dst,
176 host_t *new_src, host_t *new_dst, bool encap);
177
178 /**
179 * Delete a previusly installed SA from the SAD.
180 *
181 * @param dst destination address for this SA
182 * @param spi SPI allocated by us or remote peer
183 * @param protocol protocol for this SA (ESP/AH)
184 * @return SUCCESS if operation completed
185 */
186 status_t (*del_sa) (kernel_ipsec_t *this, host_t *dst, u_int32_t spi,
187 protocol_id_t protocol);
188
189 /**
190 * Add a policy to the SPD.
191 *
192 * A policy is always associated to an SA. Traffic which matches a
193 * policy is handled by the SA with the same reqid.
194 *
195 * @param src source address of SA
196 * @param dst dest address of SA
197 * @param src_ts traffic selector to match traffic source
198 * @param dst_ts traffic selector to match traffic dest
199 * @param direction direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
200 * @param protocol protocol to use to protect traffic (AH/ESP)
201 * @param reqid unique ID of an SA to use to enforce policy
202 * @param high_prio if TRUE, uses a higher priority than any with FALSE
203 * @param mode mode of SA (tunnel, transport)
204 * @param ipcomp the IPComp transform used
205 * @return SUCCESS if operation completed
206 */
207 status_t (*add_policy) (kernel_ipsec_t *this,
208 host_t *src, host_t *dst,
209 traffic_selector_t *src_ts,
210 traffic_selector_t *dst_ts,
211 policy_dir_t direction, protocol_id_t protocol,
212 u_int32_t reqid, bool high_prio, ipsec_mode_t mode,
213 u_int16_t ipcomp);
214
215 /**
216 * Query the use time of a policy.
217 *
218 * The use time of a policy is the time the policy was used
219 * for the last time.
220 *
221 * @param src_ts traffic selector to match traffic source
222 * @param dst_ts traffic selector to match traffic dest
223 * @param direction direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
224 * @param[out] use_time the time of this SA's last use
225 * @return SUCCESS if operation completed
226 */
227 status_t (*query_policy) (kernel_ipsec_t *this,
228 traffic_selector_t *src_ts,
229 traffic_selector_t *dst_ts,
230 policy_dir_t direction, u_int32_t *use_time);
231
232 /**
233 * Remove a policy from the SPD.
234 *
235 * The kernel interface implements reference counting for policies.
236 * If the same policy is installed multiple times (in the case of rekeying),
237 * the reference counter is increased. del_policy() decreases the ref counter
238 * and removes the policy only when no more references are available.
239 *
240 * @param src_ts traffic selector to match traffic source
241 * @param dst_ts traffic selector to match traffic dest
242 * @param direction direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
243 * @return SUCCESS if operation completed
244 */
245 status_t (*del_policy) (kernel_ipsec_t *this,
246 traffic_selector_t *src_ts,
247 traffic_selector_t *dst_ts,
248 policy_dir_t direction);
249
250 /**
251 * Destroy the implementation.
252 */
253 void (*destroy) (kernel_ipsec_t *this);
254 };
255
256 #endif /* KERNEL_IPSEC_H_ @} */