root/trunk/src/charon/bus/bus.h

/*
 * Copyright (C) 2006 Martin Willi
 * 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 bus bus
 * @{ @ingroup charon
 */

#ifndef BUS_H_
#define BUS_H_

typedef enum debug_t debug_t;
typedef enum level_t level_t;
typedef struct listener_t listener_t;
typedef struct bus_t bus_t;

#include <stdarg.h>

#include <sa/ike_sa.h>
#include <sa/child_sa.h>
#include <processing/jobs/job.h>

/**
 * Debug message group.
 */
enum debug_t {
    /** daemon main loop */
    DBG_DMN,
    /** IKE_SA_MANAGER */
    DBG_MGR,
    /** IKE_SA */
    DBG_IKE,
    /** CHILD_SA */
    DBG_CHD,
    /** job processing */
    DBG_JOB,
    /** configuration backends */
    DBG_CFG,
    /** kernel interface */
    DBG_KNL,
    /** networking/sockets */
    DBG_NET,
    /** message encoding/decoding */
    DBG_ENC,
    /** libstrongswan via logging hook */
    DBG_LIB,
    /** number of groups */
    DBG_MAX,
    /** pseudo group with all groups */
    DBG_ANY = DBG_MAX,
};

/**
 * short names of debug message group.
 */
extern enum_name_t *debug_names;

/**
 * short names of debug message group, lower case.
 */
extern enum_name_t *debug_lower_names;

/**
 * Debug levels used to control output verbosity.
 */
enum level_t {
    /** absolutely silent */
    LEVEL_SILENT =  -1,
    /** most important auditing logs */
    LEVEL_AUDIT =    0,
    /** control flow */
    LEVEL_CTRL =     1,
    /** diagnose problems */
    LEVEL_DIAG =     2,
    /** raw binary blobs */
    LEVEL_RAW =      3,
    /** including sensitive data (private keys) */
    LEVEL_PRIVATE =  4,
};

#ifndef DEBUG_LEVEL
# define DEBUG_LEVEL 4
#endif /* DEBUG_LEVEL */

#if DEBUG_LEVEL >= 0
#define DBG0(group, format, ...) charon->bus->log(charon->bus, group, 0, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL >= 0 */
#if DEBUG_LEVEL >= 1
#define DBG1(group, format, ...) charon->bus->log(charon->bus, group, 1, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL >= 1 */
#if DEBUG_LEVEL >= 2
#define DBG2(group, format, ...) charon->bus->log(charon->bus, group, 2, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL >= 2 */
#if DEBUG_LEVEL >= 3
#define DBG3(group, format, ...) charon->bus->log(charon->bus, group, 3, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL >= 3 */
#if DEBUG_LEVEL >= 4
#define DBG4(group, format, ...) charon->bus->log(charon->bus, group, 4, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL >= 4 */

#ifndef DBG0
# define DBG0(...) {}
#endif /* DBG0 */
#ifndef DBG1
# define DBG1(...) {}
#endif /* DBG1 */
#ifndef DBG2
# define DBG2(...) {}
#endif /* DBG2 */
#ifndef DBG3
# define DBG3(...) {}
#endif /* DBG3 */
#ifndef DBG4
# define DBG4(...) {}
#endif /* DBG4 */


/**
 * Listener interface, listens to events if registered to the bus.
 */
struct listener_t {
    
    /**
     * Log a debugging message.
     *
     * The implementing signal function returns TRUE to stay registered
     * to the bus, or FALSE to unregister itself.
     * Calling bus_t.log() inside of a registered listener is possible,
     * but the bus does not invoke listeners recursively.
     *
     * @param singal    kind of the signal (up, down, rekeyed, ...)
     * @param level     verbosity level of the signal
     * @param thread    ID of the thread raised this signal
     * @param ike_sa    IKE_SA associated to the event
     * @param format    printf() style format string
     * @param args      vprintf() style va_list argument list
     " @return          TRUE to stay registered, FALSE to unregister
     */
    bool (*log) (listener_t *this, debug_t group, level_t level, int thread,
                 ike_sa_t *ike_sa, char* format, va_list args);
    
    /**
     * Handle state changes in an IKE_SA.
     *
     * @param ike_sa    IKE_SA which changes its state
     * @param state     new IKE_SA state this IKE_SA changes to
     * @return          TRUE to stay registered, FALSE to unregister
     */
    bool (*ike_state_change)(listener_t *this, ike_sa_t *ike_sa,
                             ike_sa_state_t state);
    
    /**
     * Handle state changes in a CHILD_SA.
     *
     * @param ike_sa    IKE_SA containing the affected CHILD_SA
     * @param child_sa  CHILD_SA which changes its state
     * @param state     new CHILD_SA state this CHILD_SA changes to
     * @return          TRUE to stay registered, FALSE to unregister
     */
    bool (*child_state_change)(listener_t *this, ike_sa_t *ike_sa,
                               child_sa_t *child_sa, child_sa_state_t state);
    
    /**
     * Hook called for received/sent messages of an IKE_SA.
     *
     * @param ike_sa    IKE_SA sending/receving a message
     * @param message   message object
     * @param incoming  TRUE for incoming messages, FALSE for outgoing
     * @return          TRUE to stay registered, FALSE to unregister
     */
    bool (*message)(listener_t *this, ike_sa_t *ike_sa, message_t *message,
                    bool incoming);
    
    /**
     * Hook called with IKE_SA key material.
     *
     * @param ike_sa    IKE_SA this keymat belongs to
     * @param dh        diffie hellman shared secret
     * @param nonce_i   initiators nonce
     * @param nonce_r   responders nonce
     * @param rekey     IKE_SA we are rekeying, if any
     * @return          TRUE to stay registered, FALSE to unregister
     */
    bool (*ike_keys)(listener_t *this, ike_sa_t *ike_sa, diffie_hellman_t *dh,
                     chunk_t nonce_i, chunk_t nonce_r, ike_sa_t *rekey);
    
    /**
     * Hook called with CHILD_SA key material.
     *
     * @param ike_sa    IKE_SA the child sa belongs to
     * @param child_sa  CHILD_SA this keymat is used for
     * @param dh        diffie hellman shared secret
     * @param nonce_i   initiators nonce
     * @param nonce_r   responders nonce
     * @return          TRUE to stay registered, FALSE to unregister
     */
    bool (*child_keys)(listener_t *this, ike_sa_t *ike_sa, child_sa_t *child_sa,
                       diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r);
};

/**
 * The bus receives events and sends them to all registered listeners.
 *
 * Any events sent to are delivered to all registered listeners. Threads
 * may wait actively to events using the blocking listen() call.
 */
struct bus_t {
    
    /**
     * Register a listener to the bus.
     *
     * A registered listener receives all events which are sent to the bus.
     * The listener is passive; the thread which emitted the event
     * processes the listener routine.
     *
     * @param listener  listener to register.
     */
    void (*add_listener) (bus_t *this, listener_t *listener);
    
    /**
     * Unregister a listener from the bus.
     *
     * @param listener  listener to unregister.
     */
    void (*remove_listener) (bus_t *this, listener_t *listener);
    
    /**
     * Register a listener and block the calling thread.
     *
     * This call registers a listener and blocks the calling thread until
     * its listeners function returns FALSE. This allows to wait for certain
     * events. The associated job is executed after the listener has been
     * registered: This allows to listen on events we initiate with the job,
     * without missing any events to job may fire.
     *
     * @param listener  listener to register
     * @param job       job to execute asynchronously when registered, or NULL
     */
    void (*listen)(bus_t *this, listener_t *listener, job_t *job);
    
    /**
     * Set the IKE_SA the calling thread is using.
     *
     * To associate an received log message to an IKE_SA without passing it as
     * parameter each time, the thread registers the currenlty used IKE_SA
     * during check-out. Before check-in, the thread unregisters the IKE_SA. 
     * This IKE_SA is stored per-thread, so each thread has its own IKE_SA
     * registered.
     * 
     * @param ike_sa    ike_sa to register, or NULL to unregister
     */
    void (*set_sa) (bus_t *this, ike_sa_t *ike_sa);
    
    /**
     * Send a log message to the bus.
     *
     * The signal specifies the type of the event occured. The format string
     * specifies an additional informational or error message with a
     * printf() like variable argument list.
     * Use the DBG() macros.
     *
     * @param group     debugging group
     * @param level     verbosity level of the signal
     * @param format    printf() style format string
     * @param ...       printf() style argument list
     */
    void (*log)(bus_t *this, debug_t group, level_t level, char* format, ...);
    
    /**
     * Send a log message to the bus using va_list arguments.
     *
     * Same as bus_t.signal(), but uses va_list argument list.
     *
     * @param group     kind of the signal (up, down, rekeyed, ...)
     * @param level     verbosity level of the signal
     * @param format    printf() style format string
     * @param args      va_list arguments
     */
    void (*vlog)(bus_t *this, debug_t group, level_t level,
                 char* format, va_list args);
    /**
     * Send a IKE_SA state change event to the bus.
     *
     * @param ike_sa    IKE_SA which changes its state
     * @param state     new state IKE_SA changes to
     */
    void (*ike_state_change)(bus_t *this, ike_sa_t *ike_sa,
                             ike_sa_state_t state);
    /**
     * Send a CHILD_SA state change event to the bus.
     *
     * @param child_sa  CHILD_SA which changes its state
     * @param state     new state CHILD_SA changes to
     */
    void (*child_state_change)(bus_t *this, child_sa_t *child_sa,
                               child_sa_state_t state);
    /**
     * Message send/receive hook.
     *
     * @param message   message to send/receive
     * @param incoming  TRUE for incoming messages, FALSE for outgoing
     */
    void (*message)(bus_t *this, message_t *message, bool incoming);
    
    /**
     * IKE_SA keymat hook.
     *
     * @param ike_sa    IKE_SA this keymat belongs to
     * @param dh        diffie hellman shared secret
     * @param nonce_i   initiators nonce
     * @param nonce_r   responders nonce
     * @param rekey     IKE_SA we are rekeying, if any
     */
    void (*ike_keys)(bus_t *this, ike_sa_t *ike_sa, diffie_hellman_t *dh,
                     chunk_t nonce_i, chunk_t nonce_r, ike_sa_t *rekey);
    /**
     * CHILD_SA keymat hook.
     *
     * @param child_sa  CHILD_SA this keymat is used for
     * @param dh        diffie hellman shared secret
     * @param nonce_i   initiators nonce
     * @param nonce_r   responders nonce
     */
    void (*child_keys)(bus_t *this, child_sa_t *child_sa, diffie_hellman_t *dh,
                       chunk_t nonce_i, chunk_t nonce_r);
    /**
     * Destroy the event bus.
     */
    void (*destroy) (bus_t *this);
};

/**
 * Create the event bus which forwards events to its listeners.
 *
 * @return      event bus instance
 */
bus_t *bus_create();

#endif /* BUS_H_ @} */