/** * @file kernel_interface.h * * @brief Interface of kernel_interface_t. * */ /* * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger * Copyright (C) 2005-2006 Martin Willi * Copyright (C) 2005 Jan Hutter * Hochschule fuer Technik Rapperswil * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. See . * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. */ #ifndef KERNEL_INTERFACE_H_ #define KERNEL_INTERFACE_H_ typedef enum policy_dir_t policy_dir_t; typedef struct kernel_interface_t kernel_interface_t; #include #include #include /** * Direction of a policy. These are equal to those * defined in xfrm.h, but we want to stay implementation * neutral here. * * @ingroup kernel */ enum policy_dir_t { /** Policy for inbound traffic */ POLICY_IN = 0, /** Policy for outbound traffic */ POLICY_OUT = 1, /** Policy for forwarded traffic */ POLICY_FWD = 2, }; /** * @brief Interface to the kernel. * * The kernel interface handles the communication with the kernel * for SA and policy management. It allows setup of these, and provides * further the handling of kernel events. * Policy information are cached in the interface. This is necessary to do * reference counting. The Linux kernel does not allow the same policy * installed twice, but we need this as CHILD_SA exist multiple times * when rekeying. Thats why we do reference counting of policies. * * @b Constructors: * - kernel_interface_create() * * @ingroup kernel */ struct kernel_interface_t { /** * @brief Get a SPI from the kernel. * * @warning get_spi() implicitely creates an SA with * the allocated SPI, therefore the replace flag * in add_sa() must be set when installing this SA. * * @param this calling object * @param src source address of SA * @param dst destination address of SA * @param protocol protocol for SA (ESP/AH) * @param reqid unique ID for this SA * @param[out] spi allocated spi * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*get_spi)(kernel_interface_t *this, host_t *src, host_t *dst, protocol_id_t protocol, u_int32_t reqid, u_int32_t *spi); /** * @brief Add an SA to the SAD. * * add_sa() may update an already allocated * SPI (via get_spi). In this case, the replace * flag must be set. * This function does install a single SA for a * single protocol in one direction. The kernel-interface * gets the keys itself from the PRF, as we don't know * his algorithms and key sizes. * * @param this calling object * @param src source address for this SA * @param dst destination address for this SA * @param spi SPI allocated by us or remote peer * @param protocol protocol for this SA (ESP/AH) * @param reqid unique ID for this SA * @param expire_soft lifetime in seconds before rekeying * @param expire_hard lieftime in seconds before delete * @param enc_alg Algorithm to use for encryption (ESP only) * @param int_alg Algorithm to use for integrity protection * @param prf_plus PRF to derive keys from * @param mode mode of the SA (tunnel, transport) * @param encap enable UDP encapsulation for NAT traversal * @param replace Should an already installed SA be updated? * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*add_sa) (kernel_interface_t *this, host_t *src, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int32_t reqid, u_int64_t expire_soft, u_int64_t expire_hard, algorithm_t *enc_alg, algorithm_t *int_alg, prf_plus_t *prf_plus, mode_t mode, bool encap, bool update); /** * @brief Update the hosts on an installed SA. * * We cannot directly update the destination address as the kernel * requires the spi, the protocol AND the destination address (and family) * to identify SAs. Therefore if the destination address changed we * create a new SA and delete the old one. * * @param this calling object * @param spi SPI of the SA * @param protocol protocol for this SA (ESP/AH) * @param src current source address * @param dst current destination address * @param new_src new source address * @param new_dst new destination address * @param encap use UDP encapsulation * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*update_sa)(kernel_interface_t *this, u_int32_t spi, protocol_id_t protocol, host_t *src, host_t *dst, host_t *new_src, host_t *new_dst, bool encap); /** * @brief Query the use time of an SA. * * The use time of an SA is not the time of the last usage, but * the time of the first usage of the SA. * * @param this calling object * @param dst destination address for this SA * @param spi SPI allocated by us or remote peer * @param protocol protocol for this SA (ESP/AH) * @param[out] use_time the time of this SA's last use * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*query_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int32_t *use_time); /** * @brief Delete a previusly installed SA from the SAD. * * @param this calling object * @param dst destination address for this SA * @param spi SPI allocated by us or remote peer * @param protocol protocol for this SA (ESP/AH) * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*del_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi, protocol_id_t protocol); /** * @brief Add a policy to the SPD. * * A policy is always associated to an SA. Traffic which matches a * policy is handled by the SA with the same reqid. * * @param this calling object * @param src source address of SA * @param dst dest address of SA * @param src_ts traffic selector to match traffic source * @param dst_ts traffic selector to match traffic dest * @param direction direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD * @param protocol protocol to use to protect traffic (AH/ESP) * @param reqid uniqe ID of an SA to use to enforce policy * @param high_prio if TRUE, uses a higher priority than any with FALSE * @param mode mode of SA (tunnel, transport) * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*add_policy) (kernel_interface_t *this, host_t *src, host_t *dst, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, protocol_id_t protocol, u_int32_t reqid, bool high_prio, mode_t mode); /** * @brief Query the use time of a policy. * * The use time of a policy is the time the policy was used * for the last time. * * @param this calling object * @param src_ts traffic selector to match traffic source * @param dst_ts traffic selector to match traffic dest * @param direction direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD * @param[out] use_time the time of this SA's last use * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*query_policy) (kernel_interface_t *this, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, u_int32_t *use_time); /** * @brief Remove a policy from the SPD. * * The kernel interface implements reference counting for policies. * If the same policy is installed multiple times (in the case of rekeying), * the reference counter is increased. del_policy() decreases the ref counter * and removes the policy only when no more references are available. * * @param this calling object * @param src_ts traffic selector to match traffic source * @param dst_ts traffic selector to match traffic dest * @param direction direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*del_policy) (kernel_interface_t *this, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction); /** * @brief Get our outgoing source address for a destination. * * Does a route lookup to get the source address used to reach dest. * The returned host is allocated and must be destroyed. * * @param this calling object * @param dest target destination address * @return outgoing source address, NULL if unreachable */ host_t* (*get_source_addr)(kernel_interface_t *this, host_t *dest); /** * @brief Get the interface name of a local address. * * @param this calling object * @param host address to get interface name from * @return allocated interface name, or NULL if not found */ char* (*get_interface) (kernel_interface_t *this, host_t *host); /** * @brief Creates an iterator over all local addresses. * * This function blocks an internal cached address list until the * iterator gets destroyed. * These hosts are read-only, do not modify or free. * * @param this calling object * @return iterator over host_t's */ iterator_t *(*create_address_iterator) (kernel_interface_t *this); /** * @brief Add a virtual IP to an interface. * * Virtual IPs are attached to an interface. If an IP is added multiple * times, the IP is refcounted and not removed until del_ip() was called * as many times as add_ip(). * The virtual IP is attached to the interface where the iface_ip is found. * * @param this calling object * @param virtual_ip virtual ip address to assign * @param iface_ip IP of an interface to attach virtual IP * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*add_ip) (kernel_interface_t *this, host_t *virtual_ip, host_t *iface_ip); /** * @brief Remove a virtual IP from an interface. * * The kernel interface uses refcounting, see add_ip(). * * @param this calling object * @param virtual_ip virtual ip address to assign * @return * - SUCCESS * - FAILED if kernel comm failed */ status_t (*del_ip) (kernel_interface_t *this, host_t *virtual_ip); /** * @brief Destroys a kernel_interface object. * * @param kernel_interface_t calling object */ void (*destroy) (kernel_interface_t *kernel_interface); }; /** * @brief Creates an object of type kernel_interface_t. * * @ingroup kernel */ kernel_interface_t *kernel_interface_create(void); #endif /*KERNEL_INTERFACE_H_*/