root/trunk/src/charon/kernel/kernel_interface.h

/*
 * Copyright (C) 2006-2008 Tobias Brunner
 * Copyright (C) 2006 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 <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * 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.
 *
 * $Id$
 */

/**
 * @defgroup kernel_interface kernel_interface
 * @{ @ingroup kernel
 */

#ifndef KERNEL_INTERFACE_H_
#define KERNEL_INTERFACE_H_

typedef struct kernel_interface_t kernel_interface_t;

#include <utils/host.h>
#include <crypto/prf_plus.h>
#include <encoding/payloads/proposal_substructure.h>

#include <kernel/kernel_ipsec.h>
#include <kernel/kernel_net.h>

/**
 * Constructor function for ipsec kernel interface
 */
typedef kernel_ipsec_t* (*kernel_ipsec_constructor_t)(void);

/**
 * Constructor function for network kernel interface
 */
typedef kernel_net_t* (*kernel_net_constructor_t)(void);

/**
 * Manager and wrapper for different kernel interfaces.
 * 
 * The kernel interface handles the communication with the kernel
 * for SA and policy management and interface and IP address management.
 */
struct kernel_interface_t {

    /**
     * Get a SPI from the kernel.
     *
     * @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 spi       allocated spi
     * @return              SUCCESS if operation completed
     */
    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);
    
    /**
     * Get a Compression Parameter Index (CPI) from the kernel.
     * 
     * @param src       source address of SA
     * @param dst       destination address of SA
     * @param reqid     unique ID for the corresponding SA
     * @param cpi       allocated cpi
     * @return              SUCCESS if operation completed
     */
    status_t (*get_cpi)(kernel_interface_t *this, host_t *src, host_t *dst, 
                        u_int32_t reqid, u_int16_t *cpi);
    
    /**
     * 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 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   lifetime in seconds before delete
     * @param enc_alg       Algorithm to use for encryption (ESP only)
     * @param enc_key       key to use for encryption
     * @param int_alg       Algorithm to use for integrity protection
     * @param int_key       key to use for integrity protection
     * @param mode          mode of the SA (tunnel, transport)
     * @param ipcomp        IPComp transform to use
     * @param cpi           CPI for IPComp
     * @param encap         enable UDP encapsulation for NAT traversal
     * @param inbound       TRUE if this is an inbound SA
     * @return              SUCCESS if operation completed
     */
    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,
                        u_int16_t enc_alg, chunk_t enc_key,
                        u_int16_t int_alg, chunk_t int_key,
                        ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi,
                        bool encap, bool inbound);
    
    /**
     * 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 spi           SPI of the SA
     * @param protocol      protocol for this SA (ESP/AH)
     * @param cpi           CPI for IPComp, 0 if no IPComp is used
     * @param src           current source address
     * @param dst           current destination address
     * @param new_src       new source address
     * @param new_dst       new destination address
     * @param encap         current use of UDP encapsulation
     * @param new_encap     new use of UDP encapsulation
     * @return              SUCCESS if operation completed, NOT_SUPPORTED if
     *                      the kernel interface can't update the SA
     */
    status_t (*update_sa)(kernel_interface_t *this,
                          u_int32_t spi, protocol_id_t protocol, u_int16_t cpi,
                          host_t *src, host_t *dst, 
                          host_t *new_src, host_t *new_dst,
                          bool encap, bool new_encap);
    
    /**
     * Delete a previously installed SA from the SAD.
     * 
     * @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 cpi           CPI for IPComp or 0
     * @return              SUCCESS if operation completed
     */
    status_t (*del_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi,
                        protocol_id_t protocol, u_int16_t cpi);
    
    /**
     * 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 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 spi           SPI of SA
     * @param protocol      protocol to use to protect traffic (AH/ESP)
     * @param reqid         unique ID of an SA to use to enforce policy
     * @param mode          mode of SA (tunnel, transport)
     * @param ipcomp        the IPComp transform used
     * @param cpi           CPI for IPComp
     * @param routed        TRUE, if this policy is routed in the kernel
     * @return              SUCCESS if operation completed
     */
    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, u_int32_t spi,
                            protocol_id_t protocol, u_int32_t reqid,
                            ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi,
                            bool routed);
    
    /**
     * 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 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 if operation completed
     */
    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);
    
    /**
     * 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 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 unrouted      TRUE, if this policy is unrouted from the kernel
     * @return              SUCCESS if operation completed
     */
    status_t (*del_policy) (kernel_interface_t *this,
                            traffic_selector_t *src_ts, 
                            traffic_selector_t *dst_ts,
                            policy_dir_t direction,
                            bool unrouted);
    
    /**
     * 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.
     * An optional src address can be used to check if a route is available
     * for given source to dest.
     *
     * @param dest          target destination address
     * @param src           source address to check, or NULL
     * @return              outgoing source address, NULL if unreachable
     */
    host_t* (*get_source_addr)(kernel_interface_t *this,
                               host_t *dest, host_t *src);
    
    /**
     * Get the next hop for a destination.
     *
     * Does a route lookup to get the next hop used to reach dest.
     * The returned host is allocated and must be destroyed.
     *
     * @param dest          target destination address
     * @return              next hop address, NULL if unreachable
     */
    host_t* (*get_nexthop)(kernel_interface_t *this, host_t *dest);
    
    /**
     * Get the interface name of a local address.
     *
     * @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);
    
    /**
     * Creates an enumerator over all local addresses.
     * 
     * This function blocks an internal cached address list until the
     * enumerator gets destroyed.
     * The hosts are read-only, do not modify of free.
     * 
     * @param include_down_ifaces   TRUE to enumerate addresses from down interfaces
     * @param include_virtual_ips   TRUE to enumerate virtual ip addresses
     * @return                      enumerator over host_t's
     */
    enumerator_t *(*create_address_enumerator) (kernel_interface_t *this,
                        bool include_down_ifaces, bool include_virtual_ips);
    
    /**
     * 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 virtual_ip    virtual ip address to assign
     * @param iface_ip      IP of an interface to attach virtual IP
     * @return              SUCCESS if operation completed
     */
    status_t (*add_ip) (kernel_interface_t *this, host_t *virtual_ip,
                        host_t *iface_ip);
    
    /**
     * Remove a virtual IP from an interface.
     *
     * The kernel interface uses refcounting, see add_ip().
     *
     * @param virtual_ip    virtual ip address to assign
     * @return              SUCCESS if operation completed
     */
    status_t (*del_ip) (kernel_interface_t *this, host_t *virtual_ip);
    
    /**
     * Add a route.
     * 
     * @param dst_net       destination net
     * @param prefixlen     destination net prefix length
     * @param gateway       gateway for this route
     * @param src_ip        sourc ip of the route
     * @param if_name       name of the interface the route is bound to
     * @return              SUCCESS if operation completed
     *                      ALREADY_DONE if the route already exists
     */
    status_t (*add_route) (kernel_interface_t *this, chunk_t dst_net, u_int8_t prefixlen,
                                host_t *gateway, host_t *src_ip, char *if_name);
    
    /**
     * Delete a route.
     * 
     * @param dst_net       destination net
     * @param prefixlen     destination net prefix length
     * @param gateway       gateway for this route
     * @param src_ip        sourc ip of the route
     * @param if_name       name of the interface the route is bound to
     * @return              SUCCESS if operation completed
     */
    status_t (*del_route) (kernel_interface_t *this, chunk_t dst_net, u_int8_t prefixlen,
                                host_t *gateway, host_t *src_ip, char *if_name);
    
    /**
     * manager methods
     */
    
    /**
     * Tries to find an ip address of a local interface that is included in the
     * supplied traffic selector.
     * 
     * @param ts            traffic selector
     * @param ip            returned ip (has to be destroyed)
     * @return              SUCCESS if address found
     */
    status_t (*get_address_by_ts) (kernel_interface_t *this,
                                        traffic_selector_t *ts, host_t **ip);
    
    /**
     * Register an ipsec kernel interface constructor on the manager.
     *
     * @param create            constructor to register
     */
    void (*add_ipsec_interface)(kernel_interface_t *this, kernel_ipsec_constructor_t create);
    
    /**
     * Unregister an ipsec kernel interface constructor.
     *
     * @param create            constructor to unregister
     */
    void (*remove_ipsec_interface)(kernel_interface_t *this, kernel_ipsec_constructor_t create);
    
    /**
     * Register a network kernel interface constructor on the manager.
     *
     * @param create            constructor to register
     */
    void (*add_net_interface)(kernel_interface_t *this, kernel_net_constructor_t create);
    
    /**
     * Unregister a network kernel interface constructor.
     *
     * @param create            constructor to unregister
     */
    void (*remove_net_interface)(kernel_interface_t *this, kernel_net_constructor_t create);
    
    /**
     * Create the kernel interfaces classes.
     */
    void (*create_interfaces)(kernel_interface_t *this);
    
    /**
     * Destroys a kernel_interface_manager_t object.
     */
    void (*destroy) (kernel_interface_t *this);
};

/**
 * Creates an object of type kernel_interface_t.
 */
kernel_interface_t *kernel_interface_create(void);

#endif /* KERNEL_INTERFACE_H_ @} */