src/charon/bus/bus.h

   1 /*
   2  * Copyright (C) 2006 Martin Willi
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  *
  15  * $Id$
  16  */
  17
  18 /**
  19  * @defgroup bus bus
  20  * @{ @ingroup charon
  21  */
  22
  23 #ifndef BUS_H_
  24 #define BUS_H_
  25
  26 typedef enum signal_t signal_t;
  27 typedef enum level_t level_t;
  28 typedef struct bus_listener_t bus_listener_t;
  29 typedef struct bus_t bus_t;
  30
  31 #include <stdarg.h>
  32
  33 #include <sa/ike_sa.h>
  34 #include <sa/child_sa.h>
  35 #include <processing/jobs/job.h>
  36
  37
  38 /**
  39  * signals emitted by the daemon.
  40  *
  41  * Signaling is for different purporses. First, it allows debugging via
  42  * "debugging signal messages", sencondly, it allows to follow certain
  43  * mechanisms currently going on in the daemon. As we are multithreaded,
  44  * and multiple transactions are involved, it's not possible to follow
  45  * one connection setup without further infrastructure. These infrastructure
  46  * is provided by the bus and the signals the daemon emits to the bus.
  47  *
  48  * There are different scenarios to follow these signals, but all have
  49  * the same scheme. First, a START signal is emitted to indicate the daemon
  50  * has started to do something. After a start signal, a SUCCESS or a FAILED
  51  * signal of the same type follows. This allows to track the operation. Any
  52  * Debug signal betwee a START and a SUCCESS/FAILED belongs to that operation
  53  * if the IKE_SA is the same. The thread may change, as multiple threads
  54  * may be involved in a complex scenario.
  55  */
  56 enum signal_t {
  57         /** pseudo signal, representing any other signal */
  58         SIG_ANY,
  59
  60         /** debugging message from daemon main loop */
  61         DBG_DMN,
  62         /** debugging message from IKE_SA_MANAGER */
  63         DBG_MGR,
  64         /** debugging message from an IKE_SA */
  65         DBG_IKE,
  66         /** debugging message from a CHILD_SA */
  67         DBG_CHD,
  68         /** debugging message from job processing */
  69         DBG_JOB,
  70         /** debugging message from configuration backends */
  71         DBG_CFG,
  72         /** debugging message from kernel interface */
  73         DBG_KNL,
  74         /** debugging message from networking */
  75         DBG_NET,
  76         /** debugging message from message encoding/decoding */
  77         DBG_ENC,
  78         /** debugging message from libstrongswan via logging hook */
  79         DBG_LIB,
  80
  81         /** number of debug signals */
  82         DBG_MAX,
  83
  84         /** signals for IKE_SA establishment */
  85         IKE_UP_START,
  86         IKE_UP_SUCCESS,
  87         IKE_UP_FAILED,
  88
  89         /** signals for IKE_SA delete */
  90         IKE_DOWN_START,
  91         IKE_DOWN_SUCCESS,
  92         IKE_DOWN_FAILED,
  93
  94         /** signals for IKE_SA rekeying */
  95         IKE_REKEY_START,
  96         IKE_REKEY_SUCCESS,
  97         IKE_REKEY_FAILED,
  98
  99         /** signals for CHILD_SA establishment */
 100         CHILD_UP_START,
 101         CHILD_UP_SUCCESS,
 102         CHILD_UP_FAILED,
 103
 104         /** signals for CHILD_SA delete */
 105         CHILD_DOWN_START,
 106         CHILD_DOWN_SUCCESS,
 107         CHILD_DOWN_FAILED,
 108
 109         /** signals for CHILD_SA rekeying */
 110         CHILD_REKEY_START,
 111         CHILD_REKEY_SUCCESS,
 112         CHILD_REKEY_FAILED,
 113
 114         /** signals for CHILD_SA routing */
 115         CHILD_ROUTE_START,
 116         CHILD_ROUTE_SUCCESS,
 117         CHILD_ROUTE_FAILED,
 118
 119         /** signals for CHILD_SA routing */
 120         CHILD_UNROUTE_START,
 121         CHILD_UNROUTE_SUCCESS,
 122         CHILD_UNROUTE_FAILED,
 123
 124         SIG_MAX
 125 };
 126
 127 /**
 128  * short names of signals using 3 chars
 129  */
 130 extern enum_name_t *signal_names;
 131
 132 /**
 133  * Signal levels used to control output verbosity.
 134  */
 135 enum level_t {
 136         /** numerical levels from 0 to 4 */
 137         LEVEL_0 = 0,
 138         LEVEL_1 = 1,
 139         LEVEL_2 = 2,
 140         LEVEL_3 = 3,
 141         LEVEL_4 = 4,
 142         /** absolutely silent, no signal is emitted with this level */
 143         LEVEL_SILENT = -1,
 144         /** alias for numberical levels */
 145         LEVEL_AUDIT = LEVEL_0,
 146         LEVEL_CTRL = LEVEL_1,
 147         LEVEL_CTRLMORE = LEVEL_2,
 148         LEVEL_RAW = LEVEL_3,
 149         LEVEL_PRIVATE = LEVEL_4,
 150 };
 151
 152 #ifndef DEBUG_LEVEL
 153 # define DEBUG_LEVEL 4
 154 #endif /* DEBUG_LEVEL */
 155
 156 #if DEBUG_LEVEL >= 1
 157 /**
 158  * Log a debug message via the signal bus.
 159  *
 160  * @param signal        signal_t signal description
 161  * @param format        printf() style format string
 162  * @param ...           printf() style agument list
 163  */
 164 # define DBG1(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_1, format, ##__VA_ARGS__)
 165 #endif /* DEBUG_LEVEL */
 166 #if DEBUG_LEVEL >= 2
 167 #define DBG2(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_2, format, ##__VA_ARGS__)
 168 #endif /* DEBUG_LEVEL */
 169 #if DEBUG_LEVEL >= 3
 170 #define DBG3(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_3, format, ##__VA_ARGS__)
 171 #endif /* DEBUG_LEVEL */
 172 #if DEBUG_LEVEL >= 4
 173 #define DBG4(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_4, format, ##__VA_ARGS__)
 174 #endif /* DEBUG_LEVEL */
 175
 176 #ifndef DBG1
 177 # define DBG1(...) {}
 178 #endif /* DBG1 */
 179 #ifndef DBG2
 180 # define DBG2(...) {}
 181 #endif /* DBG2 */
 182 #ifndef DBG3
 183 # define DBG3(...) {}
 184 #endif /* DBG3 */
 185 #ifndef DBG4
 186 # define DBG4(...) {}
 187 #endif /* DBG4 */
 188
 189 /**
 190  * Raise a signal for an occured event.
 191  *
 192  * @param sig           signal_t signal description
 193  * @param format        printf() style format string
 194  * @param ...           printf() style agument list
 195  */
 196 #define SIG(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_0, format, ##__VA_ARGS__)
 197
 198 /**
 199  * Get the type of a signal.
 200  *
 201  * A signal may be a debugging signal with a specific context. They have
 202  * a level specific for their context > 0. All audit signals use the
 203  * type 0. This allows filtering of singals by their type.
 204  *
 205  * @param signal        signal to get the type from
 206  * @return                      type of the signal, between 0..(DBG_MAX-1)
 207  */
 208 #define SIG_TYPE(sig) (sig > DBG_MAX ? SIG_ANY : sig)
 209
 210
 211 /**
 212  * Interface for registering at the signal bus.
 213  *
 214  * To receive signals from the bus, the client implementing the
 215  * bus_listener_t interface registers itself at the signal bus.
 216  */
 217 struct bus_listener_t {
 218
 219         /**
 220          * Send a signal to a bus listener.
 221          *
 222          * A numerical identification for the thread is included, as the
 223          * associated IKE_SA, if any. Signal specifies the type of
 224          * the event occured. The format string specifies
 225          * an additional informational or error message with a printf() like
 226          * variable argument list. This is in the va_list form, as forwarding
 227          * a "..." parameters to functions is not (cleanly) possible.
 228          * The implementing signal function returns TRUE to stay registered
 229          * to the bus, or FALSE to unregister itself.
 230          * You should not call bus_t.signal() inside of a registered listener,
 231          * as it WILL call itself recursively. If you do so, make shure to
 232          * avoid infinite recursion. Watch your stack!
 233          *
 234          * @param singal        kind of the signal (up, down, rekeyed, ...)
 235          * @param level         verbosity level of the signal
 236          * @param thread        ID of the thread raised this signal
 237          * @param ike_sa        IKE_SA associated to the event
 238          * @param format        printf() style format string
 239          * @param args          vprintf() style va_list argument list
 240          " @return                      TRUE to stay registered, FALSE to unregister
 241          */
 242         bool (*signal) (bus_listener_t *this, signal_t signal, level_t level,
 243                                         int thread, ike_sa_t *ike_sa, char* format, va_list args);
 244 };
 245
 246 /**
 247  * Signal bus which sends signals to registered listeners.
 248  *
 249  * The signal bus is not much more than a multiplexer. A listener interested
 250  * in receiving event signals registers at the bus. Any signals sent to
 251  * are delivered to all registered listeners.
 252  * To deliver signals to threads, the blocking listen() call may be used
 253  * to wait for a signal.
 254  */
 255 struct bus_t {
 256
 257         /**
 258          * Register a listener to the bus.
 259          *
 260          * A registered listener receives all signals which are sent to the bus.
 261          * The listener is passive; the thread which emitted the signal
 262          * processes the listener routine.
 263          *
 264          * @param listener      listener to register.
 265          */
 266         void (*add_listener) (bus_t *this, bus_listener_t *listener);
 267
 268         /**
 269          * Unregister a listener from the bus.
 270          *
 271          * @param listener      listener to unregister.
 272          */
 273         void (*remove_listener) (bus_t *this, bus_listener_t *listener);
 274
 275         /**
 276          * Register a listener and block the calling thread.
 277          *
 278          * This call registers a listener and blocks the calling thread until
 279          * its listeners function returns FALSE. This allows to wait for certain
 280          * events. The associated job is executed after the listener has been
 281          * registered, this allows to listen on events we initiate with the job
 282          * without missing any signals.
 283          *
 284          * @param listener      listener to register
 285          * @param job           job to execute asynchronously when registered, or NULL
 286          */
 287         void (*listen)(bus_t *this, bus_listener_t *listener, job_t *job);
 288
 289         /**
 290          * Set the IKE_SA the calling thread is using.
 291          *
 292          * To associate an received signal to an IKE_SA without passing it as
 293          * parameter each time, the thread registers it's used IKE_SA each
 294          * time it checked it out. Before checking it in, the thread unregisters
 295          * the IKE_SA (by passing NULL). This IKE_SA is stored per-thread, so each
 296          * thread has one IKE_SA registered (or not).
 297          *
 298          * @param ike_sa        ike_sa to register, or NULL to unregister
 299          */
 300         void (*set_sa) (bus_t *this, ike_sa_t *ike_sa);
 301
 302         /**
 303          * Send a signal to the bus.
 304          *
 305          * The signal specifies the type of the event occured. The format string
 306          * specifies an additional informational or error message with a
 307          * printf() like variable argument list.
 308          * Some useful macros are available to shorten this call.
 309          * @see SIG(), DBG1()
 310          *
 311          * @param singal        kind of the signal (up, down, rekeyed, ...)
 312          * @param level         verbosity level of the signal
 313          * @param format        printf() style format string
 314          * @param ...           printf() style argument list
 315          */
 316         void (*signal) (bus_t *this, signal_t signal, level_t level, char* format, ...);
 317
 318         /**
 319          * Send a signal to the bus using va_list arguments.
 320          *
 321          * Same as bus_t.signal(), but uses va_list argument list.
 322          *
 323          * @todo Improve performace of vsignal implementation. This method is
 324          * called extensively and therefore shouldn't allocate heap memory or
 325          * do other expensive tasks!
 326          *
 327          * @param singal        kind of the signal (up, down, rekeyed, ...)
 328          * @param level         verbosity level of the signal
 329          * @param format        printf() style format string
 330          * @param args          va_list arguments
 331          */
 332         void (*vsignal) (bus_t *this, signal_t signal, level_t level, char* format, va_list args);
 333
 334         /**
 335          * Destroy the signal bus.
 336          */
 337         void (*destroy) (bus_t *this);
 338 };
 339
 340 /**
 341  * Create the signal bus which multiplexes signals to its listeners.
 342  *
 343  * @return              signal bus instance
 344  */
 345 bus_t *bus_create();
 346
 347 #endif /* BUS_H_ @} */