src/libhydra/kernel/kernel_ipsec.h

   1 /*
   2  * Copyright (C) 2006-2012 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_ipsec kernel_ipsec
  21  * @{ @ingroup hkernel
  22  */
  23
  24 #ifndef KERNEL_IPSEC_H_
  25 #define KERNEL_IPSEC_H_
  26
  27 typedef struct kernel_ipsec_t kernel_ipsec_t;
  28
  29 #include <networking/host.h>
  30 #include <ipsec/ipsec_types.h>
  31 #include <selectors/traffic_selector.h>
  32 #include <plugins/plugin.h>
  33 #include <kernel/kernel_interface.h>
  34
  35 /**
  36  * Interface to the ipsec subsystem of the kernel.
  37  *
  38  * The kernel ipsec interface handles the communication with the kernel
  39  * for SA and policy management. It allows setup of these, and provides
  40  * further the handling of kernel events.
  41  * Policy information are cached in the interface. This is necessary to do
  42  * reference counting. The Linux kernel does not allow the same policy
  43  * installed twice, but we need this as CHILD_SA exist multiple times
  44  * when rekeying. Thats why we do reference counting of policies.
  45  */
  46 struct kernel_ipsec_t {
  47
  48         /**
  49          * Get the feature set supported by this kernel backend.
  50          *
  51          * @return                              ORed feature-set of backend
  52          */
  53         kernel_feature_t (*get_features)(kernel_ipsec_t *this);
  54
  55         /**
  56          * Get a SPI from the kernel.
  57          *
  58          * @param src           source address of SA
  59          * @param dst           destination address of SA
  60          * @param protocol      protocol for SA (ESP/AH)
  61          * @param reqid         unique ID for this SA
  62          * @param spi           allocated spi
  63          * @return                              SUCCESS if operation completed
  64          */
  65         status_t (*get_spi)(kernel_ipsec_t *this, host_t *src, host_t *dst,
  66                                                 u_int8_t protocol, u_int32_t reqid, u_int32_t *spi);
  67
  68         /**
  69          * Get a Compression Parameter Index (CPI) from the kernel.
  70          *
  71          * @param src           source address of SA
  72          * @param dst           destination address of SA
  73          * @param reqid         unique ID for the corresponding SA
  74          * @param cpi           allocated cpi
  75          * @return                              SUCCESS if operation completed
  76          */
  77         status_t (*get_cpi)(kernel_ipsec_t *this, host_t *src, host_t *dst,
  78                                                 u_int32_t reqid, u_int16_t *cpi);
  79
  80         /**
  81          * Add an SA to the SAD.
  82          *
  83          * add_sa() may update an already allocated
  84          * SPI (via get_spi). In this case, the replace
  85          * flag must be set.
  86          * This function does install a single SA for a
  87          * single protocol in one direction.
  88          *
  89          * @param src                   source address for this SA
  90          * @param dst                   destination address for this SA
  91          * @param spi                   SPI allocated by us or remote peer
  92          * @param protocol              protocol for this SA (ESP/AH)
  93          * @param reqid                 unique ID for this SA
  94          * @param mark                  mark for this SA
  95          * @param tfc                   Traffic Flow Confidentiality padding for this SA
  96          * @param lifetime              lifetime_cfg_t for this SA
  97          * @param enc_alg               Algorithm to use for encryption (ESP only)
  98          * @param enc_key               key to use for encryption
  99          * @param int_alg               Algorithm to use for integrity protection
 100          * @param int_key               key to use for integrity protection
 101          * @param mode                  mode of the SA (tunnel, transport)
 102          * @param ipcomp                IPComp transform to use
 103          * @param cpi                   CPI for IPComp
 104          * @param encap                 enable UDP encapsulation for NAT traversal
 105          * @param esn                   TRUE to use Extended Sequence Numbers
 106          * @param inbound               TRUE if this is an inbound SA
 107          * @param src_ts                traffic selector with BEET source address
 108          * @param dst_ts                traffic selector with BEET destination address
 109          * @return                              SUCCESS if operation completed
 110          */
 111         status_t (*add_sa) (kernel_ipsec_t *this,
 112                                                 host_t *src, host_t *dst, u_int32_t spi,
 113                                                 u_int8_t protocol, u_int32_t reqid,
 114                                                 mark_t mark, u_int32_t tfc, lifetime_cfg_t *lifetime,
 115                                                 u_int16_t enc_alg, chunk_t enc_key,
 116                                                 u_int16_t int_alg, chunk_t int_key,
 117                                                 ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi,
 118                                                 bool encap, bool esn, bool inbound,
 119                                                 traffic_selector_t *src_ts, traffic_selector_t *dst_ts);
 120
 121         /**
 122          * Update the hosts on an installed SA.
 123          *
 124          * We cannot directly update the destination address as the kernel
 125          * requires the spi, the protocol AND the destination address (and family)
 126          * to identify SAs. Therefore if the destination address changed we
 127          * create a new SA and delete the old one.
 128          *
 129          * @param spi                   SPI of the SA
 130          * @param protocol              protocol for this SA (ESP/AH)
 131          * @param cpi                   CPI for IPComp, 0 if no IPComp is used
 132          * @param src                   current source address
 133          * @param dst                   current destination address
 134          * @param new_src               new source address
 135          * @param new_dst               new destination address
 136          * @param encap                 current use of UDP encapsulation
 137          * @param new_encap             new use of UDP encapsulation
 138          * @param mark                  optional mark for this SA
 139          * @return                              SUCCESS if operation completed, NOT_SUPPORTED if
 140          *                                        the kernel interface can't update the SA
 141          */
 142         status_t (*update_sa)(kernel_ipsec_t *this,
 143                                                   u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
 144                                                   host_t *src, host_t *dst,
 145                                                   host_t *new_src, host_t *new_dst,
 146                                                   bool encap, bool new_encap, mark_t mark);
 147
 148         /**
 149          * Query the number of bytes processed by an SA from the SAD.
 150          *
 151          * @param src                   source address for this SA
 152          * @param dst                   destination address for this SA
 153          * @param spi                   SPI allocated by us or remote peer
 154          * @param protocol              protocol for this SA (ESP/AH)
 155          * @param mark                  optional mark for this SA
 156          * @param[out] bytes    the number of bytes processed by SA
 157          * @param[out] packets  number of packets processed by SA
 158          * @return                              SUCCESS if operation completed
 159          */
 160         status_t (*query_sa) (kernel_ipsec_t *this, host_t *src, host_t *dst,
 161                                                   u_int32_t spi, u_int8_t protocol, mark_t mark,
 162                                                   u_int64_t *bytes, u_int64_t *packets);
 163
 164         /**
 165          * Delete a previusly installed SA from the SAD.
 166          *
 167          * @param src                   source address for this SA
 168          * @param dst                   destination address for this SA
 169          * @param spi                   SPI allocated by us or remote peer
 170          * @param protocol              protocol for this SA (ESP/AH)
 171          * @param cpi                   CPI for IPComp or 0
 172          * @param mark                  optional mark for this SA
 173          * @return                              SUCCESS if operation completed
 174          */
 175         status_t (*del_sa) (kernel_ipsec_t *this, host_t *src, host_t *dst,
 176                                                 u_int32_t spi, u_int8_t protocol, u_int16_t cpi,
 177                                                 mark_t mark);
 178
 179         /**
 180          * Flush all SAs from the SAD.
 181          *
 182          * @return                              SUCCESS if operation completed
 183          */
 184         status_t (*flush_sas) (kernel_ipsec_t *this);
 185
 186         /**
 187          * Add a policy to the SPD.
 188          *
 189          * A policy is always associated to an SA. Traffic which matches a
 190          * policy is handled by the SA with the same reqid.
 191          *
 192          * @param src                   source address of SA
 193          * @param dst                   dest address of SA
 194          * @param src_ts                traffic selector to match traffic source
 195          * @param dst_ts                traffic selector to match traffic dest
 196          * @param direction             direction of traffic, POLICY_(IN|OUT|FWD)
 197          * @param type                  type of policy, POLICY_(IPSEC|PASS|DROP)
 198          * @param sa                    details about the SA(s) tied to this policy
 199          * @param mark                  mark for this policy
 200          * @param priority              priority of this policy
 201          * @return                              SUCCESS if operation completed
 202          */
 203         status_t (*add_policy) (kernel_ipsec_t *this,
 204                                                         host_t *src, host_t *dst,
 205                                                         traffic_selector_t *src_ts,
 206                                                         traffic_selector_t *dst_ts,
 207                                                         policy_dir_t direction, policy_type_t type,
 208                                                         ipsec_sa_cfg_t *sa, mark_t mark,
 209                                                         policy_priority_t priority);
 210
 211         /**
 212          * Query the use time of a policy.
 213          *
 214          * The use time of a policy is the time the policy was used for the last
 215          * time. It is not the system time, but a monotonic timestamp as returned
 216          * by time_monotonic.
 217          *
 218          * @param src_ts                traffic selector to match traffic source
 219          * @param dst_ts                traffic selector to match traffic dest
 220          * @param direction             direction of traffic, POLICY_(IN|OUT|FWD)
 221          * @param mark                  optional mark
 222          * @param[out] use_time the monotonic timestamp of this SA's last use
 223          * @return                              SUCCESS if operation completed
 224          */
 225         status_t (*query_policy) (kernel_ipsec_t *this,
 226                                                           traffic_selector_t *src_ts,
 227                                                           traffic_selector_t *dst_ts,
 228                                                           policy_dir_t direction, mark_t mark,
 229                                                           u_int32_t *use_time);
 230
 231         /**
 232          * Remove a policy from the SPD.
 233          *
 234          * The kernel interface implements reference counting for policies.
 235          * If the same policy is installed multiple times (in the case of rekeying),
 236          * the reference counter is increased. del_policy() decreases the ref counter
 237          * and removes the policy only when no more references are available.
 238          *
 239          * @param src_ts                traffic selector to match traffic source
 240          * @param dst_ts                traffic selector to match traffic dest
 241          * @param direction             direction of traffic, POLICY_(IN|OUT|FWD)
 242          * @param reqid                 unique ID of the associated SA
 243          * @param mark                  optional mark
 244          * @param priority              priority of the policy
 245          * @return                              SUCCESS if operation completed
 246          */
 247         status_t (*del_policy) (kernel_ipsec_t *this,
 248                                                         traffic_selector_t *src_ts,
 249                                                         traffic_selector_t *dst_ts,
 250                                                         policy_dir_t direction, u_int32_t reqid,
 251                                                         mark_t mark, policy_priority_t priority);
 252
 253         /**
 254          * Flush all policies from the SPD.
 255          *
 256          * @return                              SUCCESS if operation completed
 257          */
 258         status_t (*flush_policies) (kernel_ipsec_t *this);
 259
 260         /**
 261          * Install a bypass policy for the given socket.
 262          *
 263          * @param fd                    socket file descriptor to setup policy for
 264          * @param family                protocol family of the socket
 265          * @return                              TRUE of policy set up successfully
 266          */
 267         bool (*bypass_socket)(kernel_ipsec_t *this, int fd, int family);
 268
 269         /**
 270          * Enable decapsulation of ESP-in-UDP packets for the given port/socket.
 271          *
 272          * @param fd                    socket file descriptor
 273          * @param family                protocol family of the socket
 274          * @param port                  the UDP port
 275          * @return                              TRUE if UDP decapsulation was enabled successfully
 276          */
 277         bool (*enable_udp_decap)(kernel_ipsec_t *this, int fd, int family,
 278                                                          u_int16_t port);
 279
 280         /**
 281          * Destroy the implementation.
 282          */
 283         void (*destroy) (kernel_ipsec_t *this);
 284 };
 285
 286 /**
 287  * Helper function to (un-)register IPsec kernel interfaces from plugin features.
 288  *
 289  * This function is a plugin_feature_callback_t and can be used with the
 290  * PLUGIN_CALLBACK macro to register an IPsec kernel interface constructor.
 291  *
 292  * @param plugin                plugin registering the kernel interface
 293  * @param feature               associated plugin feature
 294  * @param reg                   TRUE to register, FALSE to unregister
 295  * @param data                  data passed to callback, an kernel_ipsec_constructor_t
 296  */
 297 bool kernel_ipsec_register(plugin_t *plugin, plugin_feature_t *feature,
 298                                                    bool reg, void *data);
 299
 300 #endif /** KERNEL_IPSEC_H_ @}*/