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          * are we currently calling this listener
 105          */
 106         bool calling;
 107
 108         /**
 109          * condvar where active listeners wait
 110          */
 111         condvar_t *condvar;
 112 };
 113
 114 /**
 115  * create a listener entry
 116  */
 117 static entry_t *entry_create(bus_listener_t *listener, bool blocker)
 118 {
 119         entry_t *this = malloc_thing(entry_t);
 120
 121         this->listener = listener;
 122         this->blocker = blocker;
 123         this->calling = FALSE;
 124         this->condvar = condvar_create(CONDVAR_DEFAULT);
 125
 126         return this;
 127 }
 128
 129 /**
 130  * destroy an entry_t
 131  */
 132 static void entry_destroy(entry_t *entry)
 133 {
 134         entry->condvar->destroy(entry->condvar);
 135         free(entry);
 136 }
 137
 138 /**
 139  * Get a unique thread number for a calling thread. Since
 140  * pthread_self returns large and ugly numbers, use this function
 141  * for logging; these numbers are incremental starting at 1
 142  */
 143 static int get_thread_number(private_bus_t *this)
 144 {
 145         static long current_num = 0;
 146         long stored_num;
 147
 148         stored_num = (long)pthread_getspecific(this->thread_id);
 149         if (stored_num == 0)
 150         {       /* first call of current thread */
 151                 pthread_setspecific(this->thread_id, (void*)++current_num);
 152                 return current_num;
 153         }
 154         else
 155         {
 156                 return stored_num;
 157         }
 158 }
 159
 160 /**
 161  * Implementation of bus_t.add_listener.
 162  */
 163 static void add_listener(private_bus_t *this, bus_listener_t *listener)
 164 {
 165         this->mutex->lock(this->mutex);
 166         this->listeners->insert_last(this->listeners, entry_create(listener, FALSE));
 167         this->mutex->unlock(this->mutex);
 168 }
 169
 170 /**
 171  * Implementation of bus_t.remove_listener.
 172  */
 173 static void remove_listener(private_bus_t *this, bus_listener_t *listener)
 174 {
 175         iterator_t *iterator;
 176         entry_t *entry;
 177
 178         this->mutex->lock(this->mutex);
 179         iterator = this->listeners->create_iterator(this->listeners, TRUE);
 180         while (iterator->iterate(iterator, (void**)&entry))
 181         {
 182                 if (entry->listener == listener)
 183                 {
 184                         iterator->remove(iterator);
 185                         entry_destroy(entry);
 186                         break;
 187                 }
 188         }
 189         iterator->destroy(iterator);
 190         this->mutex->unlock(this->mutex);
 191 }
 192
 193 typedef struct cleanup_data_t cleanup_data_t;
 194
 195 /**
 196  * data to remove a listener using pthread_cleanup handler
 197  */
 198 struct cleanup_data_t {
 199         /** bus instance */
 200         private_bus_t *this;
 201         /** listener entry */
 202         entry_t *entry;
 203 };
 204
 205 /**
 206  * pthread_cleanup handler to remove a listener
 207  */
 208 static void listener_cleanup(cleanup_data_t *data)
 209 {
 210         iterator_t *iterator;
 211         entry_t *entry;
 212
 213         iterator = data->this->listeners->create_iterator(data->this->listeners, TRUE);
 214         while (iterator->iterate(iterator, (void**)&entry))
 215         {
 216                 if (entry == data->entry)
 217                 {
 218                         iterator->remove(iterator);
 219                         entry_destroy(entry);
 220                         break;
 221                 }
 222         }
 223         iterator->destroy(iterator);
 224 }
 225
 226 /**
 227  * Implementation of bus_t.listen.
 228  */
 229 static void listen_(private_bus_t *this, bus_listener_t *listener, job_t *job)
 230 {
 231         int old;
 232         cleanup_data_t data;
 233
 234         data.this = this;
 235         data.entry = entry_create(listener, TRUE);
 236
 237         this->mutex->lock(this->mutex);
 238         this->listeners->insert_last(this->listeners, data.entry);
 239         charon->processor->queue_job(charon->processor, job);
 240         pthread_cleanup_push((void*)this->mutex->unlock, this->mutex);
 241         pthread_cleanup_push((void*)listener_cleanup, &data);
 242         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &old);
 243         while (data.entry->blocker)
 244         {
 245                 data.entry->condvar->wait(data.entry->condvar, this->mutex);
 246         }
 247         pthread_setcancelstate(old, NULL);
 248         pthread_cleanup_pop(FALSE);
 249         /* unlock mutex */
 250         pthread_cleanup_pop(TRUE);
 251         entry_destroy(data.entry);
 252 }
 253
 254 /**
 255  * Implementation of bus_t.set_sa.
 256  */
 257 static void set_sa(private_bus_t *this, ike_sa_t *ike_sa)
 258 {
 259         pthread_setspecific(this->thread_sa, ike_sa);
 260 }
 261
 262 /**
 263  * data associated to a signal, passed to callback
 264  */
 265 typedef struct {
 266         /** associated IKE_SA */
 267         ike_sa_t *ike_sa;
 268         /** invoking thread */
 269         long thread;
 270         /** signal type */
 271         signal_t signal;
 272         /** signal level */
 273         level_t level;
 274         /** signal specific user data */
 275         void *user;
 276         /** format string */
 277         char *format;
 278         /** argument list */
 279         va_list args;
 280 } signal_data_t;
 281
 282 /**
 283  * listener invocation as a list remove callback
 284  */
 285 static bool signal_cb(entry_t *entry, signal_data_t *data)
 286 {
 287         if (entry->calling)
 288         {       /* avoid recursive calls */
 289                 return FALSE;
 290         }
 291         entry->calling = TRUE;
 292         if (!entry->listener->signal(entry->listener, data->signal, data->level,
 293                         data->thread, data->ike_sa, data->user, data->format, data->args))
 294         {
 295                 if (entry->blocker)
 296                 {
 297                         entry->blocker = FALSE;
 298                         entry->condvar->signal(entry->condvar);
 299                 }
 300                 else
 301                 {
 302                         entry_destroy(entry);
 303                 }
 304                 entry->calling = FALSE;
 305                 return TRUE;
 306         }
 307         entry->calling = FALSE;
 308         return FALSE;
 309 }
 310
 311 /**
 312  * Implementation of bus_t.vsignal.
 313  */
 314 static void vsignal(private_bus_t *this, signal_t signal, level_t level,
 315                                         void *user, char* format, va_list args)
 316 {
 317         signal_data_t data;
 318
 319         data.ike_sa = pthread_getspecific(this->thread_sa);
 320         data.thread = get_thread_number(this);
 321         data.signal = signal;
 322         data.level = level;
 323         data.user = user;
 324         data.format = format;
 325         va_copy(data.args, args);
 326
 327         this->mutex->lock(this->mutex);
 328         /* we use the remove() method to invoke all listeners with small overhead */
 329         this->listeners->remove(this->listeners, &data, (void*)signal_cb);
 330         this->mutex->unlock(this->mutex);
 331
 332         va_end(data.args);
 333 }
 334
 335 /**
 336  * Implementation of bus_t.signal.
 337  */
 338 static void signal_(private_bus_t *this, signal_t signal, level_t level,
 339                                         void* data, char* format, ...)
 340 {
 341         va_list args;
 342
 343         va_start(args, format);
 344         vsignal(this, signal, level, data, format, args);
 345         va_end(args);
 346 }
 347
 348 /**
 349  * Implementation of bus_t.destroy.
 350  */
 351 static void destroy(private_bus_t *this)
 352 {
 353         this->mutex->destroy(this->mutex);
 354         this->listeners->destroy_function(this->listeners, (void*)entry_destroy);
 355         free(this);
 356 }
 357
 358 /*
 359  * Described in header.
 360  */
 361 bus_t *bus_create()
 362 {
 363         private_bus_t *this = malloc_thing(private_bus_t);
 364
 365         this->public.add_listener = (void(*)(bus_t*,bus_listener_t*))add_listener;
 366         this->public.remove_listener = (void(*)(bus_t*,bus_listener_t*))remove_listener;
 367         this->public.listen = (void(*)(bus_t*, bus_listener_t *listener, job_t *job))listen_;
 368         this->public.set_sa = (void(*)(bus_t*,ike_sa_t*))set_sa;
 369         this->public.signal = (void(*)(bus_t*,signal_t,level_t,void*,char*,...))signal_;
 370         this->public.vsignal = (void(*)(bus_t*,signal_t,level_t,void*,char*,va_list))vsignal;
 371         this->public.destroy = (void(*)(bus_t*)) destroy;
 372
 373         this->listeners = linked_list_create();
 374         this->mutex = mutex_create(MUTEX_RECURSIVE);
 375         pthread_key_create(&this->thread_id, NULL);
 376         pthread_key_create(&this->thread_sa, NULL);
 377
 378         return &this->public;
 379 }
 380