src/charon/kernel/kernel_interface.h

   1 /**
   2  * @file kernel_interface.h
   3  *
   4  * @brief Interface of kernel_interface_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
  10  * Copyright (C) 2005-2006 Martin Willi
  11  * Copyright (C) 2005 Jan Hutter
  12  * Hochschule fuer Technik Rapperswil
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License as published by the
  16  * Free Software Foundation; either version 2 of the License, or (at your
  17  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  18  *
  19  * This program is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  21  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  22  * for more details.
  23  */
  24
  25 #ifndef KERNEL_INTERFACE_H_
  26 #define KERNEL_INTERFACE_H_
  27
  28 typedef struct natt_conf_t natt_conf_t;
  29 typedef enum policy_dir_t policy_dir_t;
  30 typedef struct kernel_interface_t kernel_interface_t;
  31
  32 #include <utils/host.h>
  33 #include <crypto/prf_plus.h>
  34 #include <encoding/payloads/proposal_substructure.h>
  35
  36 /**
  37  * Configuration for NAT-T
  38  */
  39 struct natt_conf_t {
  40         /** source port to use for UDP-encapsulated packets */
  41         u_int16_t sport;
  42         /** dest port to use for UDP-encapsulated packets */
  43         u_int16_t dport;
  44 };
  45
  46 /**
  47  * Direction of a policy. These are equal to those
  48  * defined in xfrm.h, but we want to stay implementation
  49  * neutral here.
  50  */
  51 enum policy_dir_t {
  52         /** Policy for inbound traffic */
  53         POLICY_IN = 0,
  54         /** Policy for outbound traffic */
  55         POLICY_OUT = 1,
  56         /** Policy for forwarded traffic */
  57         POLICY_FWD = 2,
  58 };
  59
  60 /**
  61  * @brief Interface to the kernel.
  62  *
  63  * The kernel interface handles the communication with the kernel
  64  * for SA and policy management. It allows setup of these, and provides
  65  * further the handling of kernel events.
  66  * Policy information are cached in the interface. This is necessary to do
  67  * reference counting. The Linux kernel does not allow the same policy
  68  * installed twice, but we need this as CHILD_SA exist multiple times
  69  * when rekeying. Thats why we do reference counting of policies.
  70  *
  71  * @b Constructors:
  72  *  - kernel_interface_create()
  73  *
  74  * @ingroup threads
  75  */
  76 struct kernel_interface_t {
  77
  78         /**
  79          * @brief Get a SPI from the kernel.
  80          *
  81          * @warning get_spi() implicitely creates an SA with
  82          * the allocated SPI, therefore the replace flag
  83          * in add_sa() must be set when installing this SA.
  84          *
  85          * @param this          calling object
  86          * @param src           source address of SA
  87          * @param dst           destination address of SA
  88          * @param protocol      protocol for SA (ESP/AH)
  89          * @param reqid         unique ID for this SA
  90          * @param[out] spi      allocated spi
  91          * @return
  92          *                                      - SUCCESS
  93          *                                      - FAILED if kernel comm failed
  94          */
  95         status_t (*get_spi)(kernel_interface_t *this, host_t *src, host_t *dst,
  96                                                 protocol_id_t protocol, u_int32_t reqid, u_int32_t *spi);
  97
  98         /**
  99          * @brief Add an SA to the SAD.
 100          *
 101          * add_sa() may update an already allocated
 102          * SPI (via get_spi). In this case, the replace
 103          * flag must be set.
 104          * This function does install a single SA for a
 105          * single protocol in one direction. The kernel-interface
 106          * gets the keys itself from the PRF, as we don't know
 107          * his algorithms and key sizes.
 108          *
 109          * @param this                  calling object
 110          * @param src                   source address for this SA
 111          * @param dst                   destination address for this SA
 112          * @param spi                   SPI allocated by us or remote peer
 113          * @param protocol              protocol for this SA (ESP/AH)
 114          * @param reqid                 unique ID for this SA
 115          * @param expire_soft   lifetime in seconds before rekeying
 116          * @param expire_hard   lieftime in seconds before delete
 117          * @param enc_alg               Algorithm to use for encryption (ESP only)
 118          * @param int_alg               Algorithm to use for integrity protection
 119          * @param prf_plus              PRF to derive keys from
 120          * @param natt                  NAT-T Configuration, or NULL of no NAT-T used
 121          * @param mode                  mode of the SA (tunnel, transport)
 122          * @param replace               Should an already installed SA be updated?
 123          * @return
 124          *                                              - SUCCESS
 125          *                                              - FAILED if kernel comm failed
 126          */
 127         status_t (*add_sa) (kernel_interface_t *this,
 128                                                 host_t *src, host_t *dst, u_int32_t spi,
 129                                                 protocol_id_t protocol, u_int32_t reqid,
 130                                                 u_int64_t expire_soft, u_int64_t expire_hard,
 131                                                 algorithm_t *enc_alg, algorithm_t *int_alg,
 132                                                 prf_plus_t *prf_plus, natt_conf_t *natt,
 133                                                 mode_t mode, bool update);
 134
 135         /**
 136          * @brief Update the hosts on an installed SA.
 137          *
 138          * We cannot directly update the destination address as the kernel
 139          * requires the spi, the protocol AND the destination address (and family)
 140          * to identify SAs. Therefore if the destination address changed we
 141          * create a new SA and delete the old one.
 142          *
 143          * @param this                  calling object
 144          * @param dst                   destination address for this SA
 145          * @param spi                   SPI of the SA
 146          * @param protocol              protocol for this SA (ESP/AH)
 147          * @param new_src               new source address for this SA
 148          * @param new_dst               new destination address for this SA
 149          * @param src_changes   changes in src
 150          * @param dst_changes   changes in dst
 151          * @return
 152          *                                              - SUCCESS
 153          *                                              - FAILED if kernel comm failed
 154          */
 155         status_t (*update_sa)(kernel_interface_t *this, host_t *dst, u_int32_t spi,
 156                                                   protocol_id_t protocol,
 157                                                   host_t *new_src, host_t *new_dst,
 158                                                   host_diff_t src_changes, host_diff_t dst_changes);
 159
 160         /**
 161          * @brief Query the use time of an SA.
 162          *
 163          * The use time of an SA is not the time of the last usage, but
 164          * the time of the first usage of the SA.
 165          *
 166          * @param this                  calling object
 167          * @param dst                   destination address for this SA
 168          * @param spi                   SPI allocated by us or remote peer
 169          * @param protocol              protocol for this SA (ESP/AH)
 170          * @param[out] use_time the time of this SA's last use
 171          * @return
 172          *                                              - SUCCESS
 173          *                                              - FAILED if kernel comm failed
 174          */
 175         status_t (*query_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi,
 176                                                   protocol_id_t protocol, u_int32_t *use_time);
 177
 178         /**
 179          * @brief Delete a previusly installed SA from the SAD.
 180          *
 181          * @param this                  calling object
 182          * @param dst                   destination address for this SA
 183          * @param spi                   SPI allocated by us or remote peer
 184          * @param protocol              protocol for this SA (ESP/AH)
 185          * @return
 186          *                                              - SUCCESS
 187          *                                              - FAILED if kernel comm failed
 188          */
 189         status_t (*del_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi,
 190                                                 protocol_id_t protocol);
 191
 192         /**
 193          * @brief Add a policy to the SPD.
 194          *
 195          * A policy is always associated to an SA. Traffic which matches a
 196          * policy is handled by the SA with the same reqid.
 197          * If the update flag is set, the policy is updated with the new
 198          * src/dst addresses.
 199          * If the update flag is not set, but a such policy is already in the
 200          * kernel, the reference count to this policy is increased.
 201          *
 202          * @param this                  calling object
 203          * @param src                   source address of SA
 204          * @param dst                   dest address of SA
 205          * @param src_ts                traffic selector to match traffic source
 206          * @param dst_ts                traffic selector to match traffic dest
 207          * @param direction             direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
 208          * @param protocol              protocol to use to protect traffic (AH/ESP)
 209          * @param reqid                 uniqe ID of an SA to use to enforce policy
 210          * @param high_prio             if TRUE, uses a higher priority than any with FALSE
 211          * @param mode                  mode of SA (tunnel, transport)
 212          * @param update                update an existing policy, if TRUE
 213          * @return
 214          *                                              - SUCCESS
 215          *                                              - FAILED if kernel comm failed
 216          */
 217         status_t (*add_policy) (kernel_interface_t *this,
 218                                                         host_t *src, host_t *dst,
 219                                                         traffic_selector_t *src_ts,
 220                                                         traffic_selector_t *dst_ts,
 221                                                         policy_dir_t direction, protocol_id_t protocol,
 222                                                         u_int32_t reqid, bool high_prio,
 223                                                         mode_t mode, bool update);
 224
 225         /**
 226          * @brief Query the use time of a policy.
 227          *
 228          * The use time of a policy is the time the policy was used
 229          * for the last time.
 230          *
 231          * @param this                  calling object
 232          * @param src_ts                traffic selector to match traffic source
 233          * @param dst_ts                traffic selector to match traffic dest
 234          * @param direction             direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
 235          * @param[out] use_time the time of this SA's last use
 236          * @return
 237          *                                              - SUCCESS
 238          *                                              - FAILED if kernel comm failed
 239          */
 240         status_t (*query_policy) (kernel_interface_t *this,
 241                                                           traffic_selector_t *src_ts,
 242                                                           traffic_selector_t *dst_ts,
 243                                                           policy_dir_t direction, u_int32_t *use_time);
 244
 245         /**
 246          * @brief Remove a policy from the SPD.
 247          *
 248          * The kernel interface implements reference counting for policies.
 249          * If the same policy is installed multiple times (in the case of rekeying),
 250          * the reference counter is increased. del_policy() decreases the ref counter
 251          * and removes the policy only when no more references are available.
 252          *
 253          * @param this                  calling object
 254          * @param src_ts                traffic selector to match traffic source
 255          * @param dst_ts                traffic selector to match traffic dest
 256          * @param direction             direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
 257          * @return
 258          *                                              - SUCCESS
 259          *                                              - FAILED if kernel comm failed
 260          */
 261         status_t (*del_policy) (kernel_interface_t *this,
 262                                                         traffic_selector_t *src_ts,
 263                                                         traffic_selector_t *dst_ts,
 264                                                         policy_dir_t direction);
 265
 266         /**
 267          * @brief Get the interface name of a local address.
 268          *
 269          * @param this                  calling object
 270          * @param host                  address to get interface name from
 271          * @return                              allocated interface name, or NULL if not found
 272          */
 273         char* (*get_interface) (kernel_interface_t *this, host_t *host);
 274
 275         /**
 276          * @brief Creates a list of all local addresses.
 277          *
 278          * @param this                  calling object
 279          * @return                              allocated list with host_t objects
 280          */
 281         linked_list_t *(*create_address_list) (kernel_interface_t *this);
 282
 283         /**
 284          * @brief Add a virtual IP to an interface.
 285          *
 286          * Virtual IPs are attached to an interface. If an IP is added multiple
 287          * times, the IP is refcounted and not removed until del_ip() was called
 288          * as many times as add_ip().
 289          * The virtual IP is attached to the interface where the iface_ip is found.
 290          *
 291          * @param this                  calling object
 292          * @param virtual_ip    virtual ip address to assign
 293          * @param iface_ip              IP of an interface to attach virtual IP
 294          * @return
 295          *                                              - SUCCESS
 296          *                                              - FAILED if kernel comm failed
 297          */
 298         status_t (*add_ip) (kernel_interface_t *this, host_t *virtual_ip,
 299                                                 host_t *iface_ip);
 300
 301         /**
 302          * @brief Remove a virtual IP from an interface.
 303          *
 304          * The kernel interface uses refcounting, see add_ip().
 305          *
 306          * @param this                  calling object
 307          * @param virtual_ip    virtual ip address to assign
 308          * @param iface_ip              IP of an interface to remove virtual IP from
 309          * @return
 310          *                                              - SUCCESS
 311          *                                              - FAILED if kernel comm failed
 312          */
 313         status_t (*del_ip) (kernel_interface_t *this, host_t *virtual_ip,
 314                                                 host_t *iface_ip);
 315
 316         /**
 317          * @brief Destroys a kernel_interface object.
 318          *
 319          * @param kernel_interface_t    calling object
 320          */
 321         void (*destroy) (kernel_interface_t *kernel_interface);
 322 };
 323
 324 /**
 325  * @brief Creates an object of type kernel_interface_t.
 326  *
 327  * @ingroup threads
 328  */
 329 kernel_interface_t *kernel_interface_create(void);
 330
 331 #endif /*KERNEL_INTERFACE_H_*/