src/charon/bus/bus.c

   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 #include "bus.h"
  19
  20 #include <pthread.h>
  21
  22 #include <daemon.h>
  23 #include <utils/mutex.h>
  24
  25 ENUM(signal_names, SIG_ANY, SIG_MAX,
  26         /** should not get printed */
  27         "SIG_ANY",
  28         /** debugging message types */
  29         "DMN",
  30         "MGR",
  31         "IKE",
  32         "CHD",
  33         "JOB",
  34         "CFG",
  35         "KNL",
  36         "NET",
  37         "ENC",
  38         "LIB",
  39         /** should not get printed */
  40         "SIG_DBG_MAX",
  41         /** all level0 signals are AUDIT signals */
  42         "AUD", "AUD", "AUD",
  43         "AUD", "AUD", "AUD",
  44         "AUD", "AUD", "AUD",
  45         "AUD", "AUD", "AUD",
  46         "AUD", "AUD", "AUD",
  47         "AUD", "AUD", "AUD",
  48         "AUD", "AUD", "AUD",
  49         "AUD", "AUD", "AUD",
  50         /** should not get printed */
  51         "SIG_MAX",
  52 );
  53
  54 typedef struct private_bus_t private_bus_t;
  55
  56 /**
  57  * Private data of a bus_t object.
  58  */
  59 struct private_bus_t {
  60         /**
  61          * Public part of a bus_t object.
  62          */
  63         bus_t public;
  64
  65         /**
  66          * List of registered listeners as entry_t's
  67          */
  68         linked_list_t *listeners;
  69
  70         /**
  71          * mutex to synchronize active listeners, recursively
  72          */
  73         mutex_t *mutex;
  74
  75         /**
  76          * Thread local storage for a unique, simple thread ID
  77          */
  78         pthread_key_t thread_id;
  79
  80         /**
  81          * Thread local storage the threads IKE_SA
  82          */
  83         pthread_key_t thread_sa;
  84 };
  85
  86 typedef struct entry_t entry_t;
  87
  88 /**
  89  * a listener entry, either active or passive
  90  */
  91 struct entry_t {
  92
  93         /**
  94          * registered listener interface
  95          */
  96         bus_listener_t *listener;
  97
  98         /**
  99          * is this a active listen() call with a blocking thread
 100          */
 101         bool blocker;
 102
 103         /**
 104          * condvar where active listeners wait
 105          */
 106         condvar_t *condvar;
 107 };
 108
 109 /**
 110  * create a listener entry
 111  */
 112 static entry_t *entry_create(bus_listener_t *listener, bool blocker)
 113 {
 114         entry_t *this = malloc_thing(entry_t);
 115
 116         this->listener = listener;
 117         this->blocker = blocker;
 118         this->condvar = condvar_create(CONDVAR_DEFAULT);
 119
 120         return this;
 121 }
 122
 123 /**
 124  * destroy an entry_t
 125  */
 126 static void entry_destroy(entry_t *entry)
 127 {
 128         entry->condvar->destroy(entry->condvar);
 129         free(entry);
 130 }
 131
 132 /**
 133  * Get a unique thread number for a calling thread. Since
 134  * pthread_self returns large and ugly numbers, use this function
 135  * for logging; these numbers are incremental starting at 1
 136  */
 137 static int get_thread_number(private_bus_t *this)
 138 {
 139         static long current_num = 0;
 140         long stored_num;
 141
 142         stored_num = (long)pthread_getspecific(this->thread_id);
 143         if (stored_num == 0)
 144         {       /* first call of current thread */
 145                 pthread_setspecific(this->thread_id, (void*)++current_num);
 146                 return current_num;
 147         }
 148         else
 149         {
 150                 return stored_num;
 151         }
 152 }
 153
 154 /**
 155  * Implementation of bus_t.add_listener.
 156  */
 157 static void add_listener(private_bus_t *this, bus_listener_t *listener)
 158 {
 159         this->mutex->lock(this->mutex);
 160         this->listeners->insert_last(this->listeners, entry_create(listener, FALSE));
 161         this->mutex->unlock(this->mutex);
 162 }
 163
 164 /**
 165  * Implementation of bus_t.remove_listener.
 166  */
 167 static void remove_listener(private_bus_t *this, bus_listener_t *listener)
 168 {
 169         iterator_t *iterator;
 170         entry_t *entry;
 171
 172         this->mutex->lock(this->mutex);
 173         iterator = this->listeners->create_iterator(this->listeners, TRUE);
 174         while (iterator->iterate(iterator, (void**)&entry))
 175         {
 176                 if (entry->listener == listener)
 177                 {
 178                         iterator->remove(iterator);
 179                         entry_destroy(entry);
 180                         break;
 181                 }
 182         }
 183         iterator->destroy(iterator);
 184         this->mutex->unlock(this->mutex);
 185 }
 186
 187 typedef struct cleanup_data_t cleanup_data_t;
 188
 189 /**
 190  * data to remove a listener using pthread_cleanup handler
 191  */
 192 struct cleanup_data_t {
 193         /** bus instance */
 194         private_bus_t *this;
 195         /** listener entry */
 196         entry_t *entry;
 197 };
 198
 199 /**
 200  * pthread_cleanup handler to remove a listener
 201  */
 202 static void listener_cleanup(cleanup_data_t *data)
 203 {
 204         iterator_t *iterator;
 205         entry_t *entry;
 206
 207         iterator = data->this->listeners->create_iterator(data->this->listeners, TRUE);
 208         while (iterator->iterate(iterator, (void**)&entry))
 209         {
 210                 if (entry == data->entry)
 211                 {
 212                         iterator->remove(iterator);
 213                         entry_destroy(entry);
 214                         break;
 215                 }
 216         }
 217         iterator->destroy(iterator);
 218 }
 219
 220 /**
 221  * Implementation of bus_t.listen.
 222  */
 223 static void listen_(private_bus_t *this, bus_listener_t *listener, job_t *job)
 224 {
 225         int old;
 226         cleanup_data_t data;
 227
 228         data.this = this;
 229         data.entry = entry_create(listener, TRUE);
 230
 231         this->mutex->lock(this->mutex);
 232         this->listeners->insert_last(this->listeners, data.entry);
 233         charon->processor->queue_job(charon->processor, job);
 234         pthread_cleanup_push((void*)this->mutex->unlock, this->mutex);
 235         pthread_cleanup_push((void*)listener_cleanup, &data);
 236         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &old);
 237         while (data.entry->blocker)
 238         {
 239                 data.entry->condvar->wait(data.entry->condvar, this->mutex);
 240         }
 241         pthread_setcancelstate(old, NULL);
 242         pthread_cleanup_pop(FALSE);
 243         /* unlock mutex */
 244         pthread_cleanup_pop(TRUE);
 245         entry_destroy(data.entry);
 246 }
 247
 248 /**
 249  * Implementation of bus_t.set_sa.
 250  */
 251 static void set_sa(private_bus_t *this, ike_sa_t *ike_sa)
 252 {
 253         pthread_setspecific(this->thread_sa, ike_sa);
 254 }
 255
 256 /**
 257  * data associated to a signal, passed to callback
 258  */
 259 typedef struct {
 260         /** associated IKE_SA */
 261         ike_sa_t *ike_sa;
 262         /** invoking thread */
 263         long thread;
 264         /** signal type */
 265         signal_t signal;
 266         /** signal level */
 267         level_t level;
 268         /** format string */
 269         char *format;
 270         /** argument list */
 271         va_list args;
 272 } signal_data_t;
 273
 274 /**
 275  * listener invocation as a list remove callback
 276  */
 277 static bool signal_cb(entry_t *entry, signal_data_t *data)
 278 {
 279         if (!entry->listener->signal(entry->listener, data->signal, data->level,
 280                                                 data->thread, data->ike_sa, data->format, data->args))
 281         {
 282                 if (entry->blocker)
 283                 {
 284                         entry->blocker = FALSE;
 285                         entry->condvar->signal(entry->condvar);
 286                 }
 287                 else
 288                 {
 289                         entry_destroy(entry);
 290                 }
 291                 return TRUE;
 292         }
 293         return FALSE;
 294 }
 295
 296 /**
 297  * Implementation of bus_t.vsignal.
 298  */
 299 static void vsignal(private_bus_t *this, signal_t signal, level_t level,
 300                                         char* format, va_list args)
 301 {
 302         signal_data_t data;
 303
 304         data.ike_sa = pthread_getspecific(this->thread_sa);
 305         data.thread = get_thread_number(this);
 306         data.signal = signal;
 307         data.level = level;
 308         data.format = format;
 309         va_copy(data.args, args);
 310
 311         this->mutex->lock(this->mutex);
 312         /* we use the remove() method to invoke all listeners with small overhead */
 313         this->listeners->remove(this->listeners, &data, (void*)signal_cb);
 314         this->mutex->unlock(this->mutex);
 315
 316         va_end(data.args);
 317 }
 318
 319 /**
 320  * Implementation of bus_t.signal.
 321  */
 322 static void signal_(private_bus_t *this, signal_t signal, level_t level,
 323                                         char* format, ...)
 324 {
 325         va_list args;
 326
 327         va_start(args, format);
 328         vsignal(this, signal, level, format, args);
 329         va_end(args);
 330 }
 331
 332 /**
 333  * Implementation of bus_t.destroy.
 334  */
 335 static void destroy(private_bus_t *this)
 336 {
 337         this->mutex->destroy(this->mutex);
 338         this->listeners->destroy_function(this->listeners, (void*)entry_destroy);
 339         free(this);
 340 }
 341
 342 /*
 343  * Described in header.
 344  */
 345 bus_t *bus_create()
 346 {
 347         private_bus_t *this = malloc_thing(private_bus_t);
 348
 349         this->public.add_listener = (void(*)(bus_t*,bus_listener_t*))add_listener;
 350         this->public.remove_listener = (void(*)(bus_t*,bus_listener_t*))remove_listener;
 351         this->public.listen = (void(*)(bus_t*, bus_listener_t *listener, job_t *job))listen_;
 352         this->public.set_sa = (void(*)(bus_t*,ike_sa_t*))set_sa;
 353         this->public.signal = (void(*)(bus_t*,signal_t,level_t,char*,...))signal_;
 354         this->public.vsignal = (void(*)(bus_t*,signal_t,level_t,char*,va_list))vsignal;
 355         this->public.destroy = (void(*)(bus_t*)) destroy;
 356
 357         this->listeners = linked_list_create();
 358         this->mutex = mutex_create(MUTEX_DEFAULT);
 359         pthread_key_create(&this->thread_id, NULL);
 360         pthread_key_create(&this->thread_sa, NULL);
 361
 362         return &this->public;
 363 }
 364