src/charon/bus/bus.h

   1 /**
   2  * @file bus.h
   3  *
   4  * @brief Interface of bus_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2006 Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  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
  36
  37 /**
  38  * @brief signals emitted by the daemon.
  39  *
  40  * Signaling is for different purporses. First, it allows debugging via
  41  * "debugging signal messages", sencondly, it allows to follow certain
  42  * mechanisms currently going on in the daemon. As we are multithreaded,
  43  * and multiple transactions are involved, it's not possible to follow
  44  * one connection setup without further infrastructure. These infrastructure
  45  * is provided by the bus and the signals the daemon emits to the bus.
  46  *
  47  * There are different scenarios to follow these signals, but all have
  48  * the same scheme. First, a START signal is emitted to indicate the daemon
  49  * has started to do something. After a start signal, a SUCCESS or a FAILED
  50  * signal of the same type follows. This allows to track the operation. Any
  51  * Debug signal betwee a START and a SUCCESS/FAILED belongs to that operation
  52  * if the IKE_SA is the same. The thread may change, as multiple threads
  53  * may be involved in a complex scenario.
  54  *
  55  * @ingroup bus
  56  */
  57 enum signal_t {
  58         /** pseudo signal, representing any other signal */
  59         SIG_ANY,
  60
  61         /** debugging message from daemon main loop */
  62         DBG_DMN,
  63         /** debugging message from IKE_SA_MANAGER */
  64         DBG_MGR,
  65         /** debugging message from an IKE_SA */
  66         DBG_IKE,
  67         /** debugging message from a CHILD_SA */
  68         DBG_CHD,
  69         /** debugging message from job processing */
  70         DBG_JOB,
  71         /** debugging message from configuration backends */
  72         DBG_CFG,
  73         /** debugging message from kernel interface */
  74         DBG_KNL,
  75         /** debugging message from networking */
  76         DBG_NET,
  77         /** debugging message from message encoding/decoding */
  78         DBG_ENC,
  79         /** debugging message from libstrongswan via logging hook */
  80         DBG_LIB,
  81
  82         /** number of debug signals */
  83         DBG_MAX,
  84
  85         /** signals for IKE_SA establishment */
  86         IKE_UP_START,
  87         IKE_UP_SUCCESS,
  88         IKE_UP_FAILED,
  89
  90         /** signals for IKE_SA delete */
  91         IKE_DOWN_START,
  92         IKE_DOWN_SUCCESS,
  93         IKE_DOWN_FAILED,
  94
  95         /** signals for IKE_SA rekeying */
  96         IKE_REKEY_START,
  97         IKE_REKEY_SUCCESS,
  98         IKE_REKEY_FAILED,
  99
 100         /** signals for CHILD_SA establishment */
 101         CHILD_UP_START,
 102         CHILD_UP_SUCCESS,
 103         CHILD_UP_FAILED,
 104
 105         /** signals for CHILD_SA delete */
 106         CHILD_DOWN_START,
 107         CHILD_DOWN_SUCCESS,
 108         CHILD_DOWN_FAILED,
 109
 110         /** signals for CHILD_SA rekeying */
 111         CHILD_REKEY_START,
 112         CHILD_REKEY_SUCCESS,
 113         CHILD_REKEY_FAILED,
 114
 115         /** signals for CHILD_SA routing */
 116         CHILD_ROUTE_START,
 117         CHILD_ROUTE_SUCCESS,
 118         CHILD_ROUTE_FAILED,
 119
 120         /** signals for CHILD_SA routing */
 121         CHILD_UNROUTE_START,
 122         CHILD_UNROUTE_SUCCESS,
 123         CHILD_UNROUTE_FAILED,
 124
 125         SIG_MAX
 126 };
 127
 128 /**
 129  * short names of signals using 3 chars
 130  */
 131 extern enum_name_t *signal_names;
 132
 133 /**
 134  * Signal levels used to control output verbosity.
 135  */
 136 enum level_t {
 137         /** numerical levels from 0 to 4 */
 138         LEVEL_0 = 0,
 139         LEVEL_1 = 1,
 140         LEVEL_2 = 2,
 141         LEVEL_3 = 3,
 142         LEVEL_4 = 4,
 143         /** absolutely silent, no signal is emitted with this level */
 144         LEVEL_SILENT = -1,
 145         /** alias for numberical levels */
 146         LEVEL_AUDIT = LEVEL_0,
 147         LEVEL_CTRL = LEVEL_1,
 148         LEVEL_CTRLMORE = LEVEL_2,
 149         LEVEL_RAW = LEVEL_3,
 150         LEVEL_PRIVATE = LEVEL_4,
 151 };
 152
 153 #ifndef DEBUG_LEVEL
 154 # define DEBUG_LEVEL 4
 155 #endif /* DEBUG_LEVEL */
 156
 157 #if DEBUG_LEVEL >= 1
 158 /**
 159  * @brief Log a debug message via the signal bus.
 160  *
 161  * @param signal        signal_t signal description
 162  * @param format        printf() style format string
 163  * @param ...           printf() style agument list
 164  */
 165 # define DBG1(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_1, format, ##__VA_ARGS__)
 166 #endif /* DEBUG_LEVEL */
 167 #if DEBUG_LEVEL >= 2
 168 #define DBG2(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_2, format, ##__VA_ARGS__)
 169 #endif /* DEBUG_LEVEL */
 170 #if DEBUG_LEVEL >= 3
 171 #define DBG3(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_3, format, ##__VA_ARGS__)
 172 #endif /* DEBUG_LEVEL */
 173 #if DEBUG_LEVEL >= 4
 174 #define DBG4(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_4, format, ##__VA_ARGS__)
 175 #endif /* DEBUG_LEVEL */
 176
 177 #ifndef DBG1
 178 # define DBG1(...) {}
 179 #endif /* DBG1 */
 180 #ifndef DBG2
 181 # define DBG2(...) {}
 182 #endif /* DBG2 */
 183 #ifndef DBG3
 184 # define DBG3(...) {}
 185 #endif /* DBG3 */
 186 #ifndef DBG4
 187 # define DBG4(...) {}
 188 #endif /* DBG4 */
 189
 190 /**
 191  * @brief Raise a signal for an occured event.
 192  *
 193  * @param sig           signal_t signal description
 194  * @param format        printf() style format string
 195  * @param ...           printf() style agument list
 196  */
 197 #define SIG(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_0, format, ##__VA_ARGS__)
 198
 199 /**
 200  * @brief Get the type of a signal.
 201  *
 202  * A signal may be a debugging signal with a specific context. They have
 203  * a level specific for their context > 0. All audit signals use the
 204  * type 0. This allows filtering of singals by their type.
 205  *
 206  * @param signal        signal to get the type from
 207  * @return                      type of the signal, between 0..(DBG_MAX-1)
 208  */
 209 #define SIG_TYPE(sig) (sig > DBG_MAX ? SIG_ANY : sig)
 210
 211
 212 /**
 213  * @brief Interface for registering at the signal bus.
 214  *
 215  * To receive signals from the bus, the client implementing the
 216  * bus_listener_t interface registers itself at the signal bus.
 217  *
 218  * @ingroup bus
 219  */
 220 struct bus_listener_t {
 221
 222         /**
 223          * @brief Send a signal to a bus listener.
 224          *
 225          * A numerical identification for the thread is included, as the
 226          * associated IKE_SA, if any. Signal specifies the type of
 227          * the event occured. The format string specifies
 228          * an additional informational or error message with a printf() like
 229          * variable argument list. This is in the va_list form, as forwarding
 230          * a "..." parameters to functions is not (cleanly) possible.
 231          * The implementing signal function returns TRUE to stay registered
 232          * to the bus, or FALSE to unregister itself.
 233          *
 234          * @param this          listener
 235          * @param singal        kind of the signal (up, down, rekeyed, ...)
 236          * @param level         verbosity level of the signal
 237          * @param thread        ID of the thread raised this signal
 238          * @param ike_sa        IKE_SA associated to the event
 239          * @param format        printf() style format string
 240          * @param args          vprintf() style va_list argument list
 241          " @return                      TRUE to stay registered, FALSE to unregister
 242          */
 243         bool (*signal) (bus_listener_t *this, signal_t signal, level_t level,
 244                                         int thread, ike_sa_t *ike_sa, char* format, va_list args);
 245 };
 246
 247 /**
 248  * @brief Signal bus which sends signals to registered listeners.
 249  *
 250  * The signal bus is not much more than a multiplexer. A listener interested
 251  * in receiving event signals registers at the bus. Any signals sent to
 252  * are delivered to all registered listeners.
 253  * To deliver signals to threads, the blocking listen() call may be used
 254  * to wait for a signal. However, passive listeners should be preferred,
 255  * as listening actively requires some synchronization overhead as data
 256  * must be passed from the raising thread to the listening thread.
 257  *
 258  * @ingroup bus
 259  */
 260 struct bus_t {
 261
 262         /**
 263          * @brief Register a listener to the bus.
 264          *
 265          * A registered listener receives all signals which are sent to the bus.
 266          * The listener is passive; the thread which emitted the signal
 267          * processes the listener routine.
 268          *
 269          * @param this          bus
 270          * @param listener      listener to register.
 271          */
 272         void (*add_listener) (bus_t *this, bus_listener_t *listener);
 273
 274         /**
 275          * @brief Unregister a listener from the bus.
 276          *
 277          * @param this          bus
 278          * @param listener      listener to unregister.
 279          */
 280         void (*remove_listener) (bus_t *this, bus_listener_t *listener);
 281
 282         /**
 283          * @brief Listen actively on the bus.
 284          *
 285          * As we are fully multithreaded, we must provide a mechanism
 286          * for active threads to listen to the bus. With the listen() method,
 287          * a thread waits until a signal occurs, and then processes it.
 288          * To prevent the listen() calling thread to miss signals emitted while
 289          * it processes a signal, registration is required. This is done through
 290          * the set_listen_state() method, see below.
 291          *
 292          * The listen() function is (has) a thread cancellation point, so you might
 293          * want to register cleanup handlers.
 294          *
 295          * @param this          bus
 296          * @param level         verbosity level of the signal
 297          * @param thread        receives thread number emitted the signal
 298          * @param ike_sa        receives the IKE_SA involved in the signal, or NULL
 299          * @param format        receives the format string supplied with the signal
 300          * @param va_list       receives the variable argument list for format
 301          * @return                      the emitted signal type
 302          */
 303         signal_t (*listen) (bus_t *this, level_t* level, int *thread,
 304                                                 ike_sa_t **ike_sa, char** format, va_list* args);
 305
 306         /**
 307          * @brief Set the listening state of the calling thread.
 308          *
 309          * To prevent message loss for active listeners using listen(), threads
 310          * must register themself to the bus before starting to listen(). When
 311          * a signal occurs, the emitter waits until all threads with listen_state
 312          * TRUE are waiting in the listen() method to process the signal.
 313          * It is important that a thread with liste_state TRUE calls listen()
 314          * periodically, or sets it's listening state to FALSE; otherwise
 315          * all signal emitting threads get blocked on the bus.
 316          *
 317          * @param this          bus
 318          * @param active        TRUE to set to listening
 319          */
 320         void (*set_listen_state) (bus_t *this, bool active);
 321
 322         /**
 323          * @brief Set the IKE_SA the calling thread is using.
 324          *
 325          * To associate an received signal to an IKE_SA without passing it as
 326          * parameter each time, the thread registers it's used IKE_SA each
 327          * time it checked it out. Before checking it in, the thread unregisters
 328          * the IKE_SA (by passing NULL). This IKE_SA is stored per-thread, so each
 329          * thread has one IKE_SA registered (or not).
 330          *
 331          * @param this          bus
 332          * @param ike_sa        ike_sa to register, or NULL to unregister
 333          */
 334         void (*set_sa) (bus_t *this, ike_sa_t *ike_sa);
 335
 336         /**
 337          * @brief Send a signal to the bus.
 338          *
 339          * The signal specifies the type of the event occured. The format string
 340          * specifies an additional informational or error message with a
 341          * printf() like variable argument list.
 342          * Some useful macros are available to shorten this call.
 343          * @see SIG(), DBG1()
 344          *
 345          * @param this          bus
 346          * @param singal        kind of the signal (up, down, rekeyed, ...)
 347          * @param level         verbosity level of the signal
 348          * @param format        printf() style format string
 349          * @param ...           printf() style argument list
 350          */
 351         void (*signal) (bus_t *this, signal_t signal, level_t level, char* format, ...);
 352
 353         /**
 354          * @brief Send a signal to the bus using va_list arguments.
 355          *
 356          * Same as bus_t.signal(), but uses va_list argument list.
 357          *
 358          * @param this          bus
 359          * @param singal        kind of the signal (up, down, rekeyed, ...)
 360          * @param level         verbosity level of the signal
 361          * @param format        printf() style format string
 362          * @param args          va_list arguments
 363          */
 364         void (*vsignal) (bus_t *this, signal_t signal, level_t level, char* format, va_list args);
 365
 366         /**
 367          * @brief Destroy the signal bus.
 368          *
 369          * @param this          bus to destroy
 370          */
 371         void (*destroy) (bus_t *this);
 372 };
 373
 374 /**
 375  * @brief Create the signal bus which multiplexes signals to its listeners.
 376  *
 377  * @return              signal bus instance
 378  *
 379  * @ingroup bus
 380  */
 381 bus_t *bus_create();
 382
 383 #endif /* BUS_H_ */