apps/app_alarmreceiver.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C)  2004 - 2005 Steve Rodgers
   5  *
   6  * Steve Rodgers <hwstar@rodgers.sdcoxmail.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  * \brief Central Station Alarm receiver for Ademco Contact ID
  21  * \author Steve Rodgers <hwstar@rodgers.sdcoxmail.com>
  22  *
  23  * *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING ***
  24  *
  25  * Use at your own risk. Please consult the GNU GPL license document included with Asterisk.         *
  26  *
  27  * *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING ***
  28  *
  29  * \ingroup applications
  30  */
  31
  32 #include "asterisk.h"
  33
  34 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  35
  36 #include <math.h>
  37 #include <sys/wait.h>
  38 #include <sys/time.h>
  39
  40 #include "asterisk/lock.h"
  41 #include "asterisk/file.h"
  42 #include "asterisk/channel.h"
  43 #include "asterisk/pbx.h"
  44 #include "asterisk/module.h"
  45 #include "asterisk/translate.h"
  46 #include "asterisk/ulaw.h"
  47 #include "asterisk/app.h"
  48 #include "asterisk/dsp.h"
  49 #include "asterisk/config.h"
  50 #include "asterisk/localtime.h"
  51 #include "asterisk/callerid.h"
  52 #include "asterisk/astdb.h"
  53 #include "asterisk/utils.h"
  54
  55 #define ALMRCV_CONFIG "alarmreceiver.conf"
  56 #define ADEMCO_CONTACT_ID "ADEMCO_CONTACT_ID"
  57
  58 struct event_node{
  59         char data[17];
  60         struct event_node *next;
  61 };
  62
  63 typedef struct event_node event_node_t;
  64
  65 static char *app = "AlarmReceiver";
  66
  67 static char *synopsis = "Provide support for receiving alarm reports from a burglar or fire alarm panel";
  68 static char *descrip =
  69 "  AlarmReceiver(): Only 1 signalling format is supported at this time: Ademco\n"
  70 "Contact ID. This application should be called whenever there is an alarm\n"
  71 "panel calling in to dump its events. The application will handshake with the\n"
  72 "alarm panel, and receive events, validate them, handshake them, and store them\n"
  73 "until the panel hangs up. Once the panel hangs up, the application will run the\n"
  74 "system command specified by the eventcmd setting in alarmreceiver.conf and pipe\n"
  75 "the events to the standard input of the application. The configuration file also\n"
  76 "contains settings for DTMF timing, and for the loudness of the acknowledgement\n"
  77 "tones.\n";
  78
  79 /* Config Variables */
  80 static int fdtimeout = 2000;
  81 static int sdtimeout = 200;
  82 static int toneloudness = 4096;
  83 static int log_individual_events = 0;
  84 static char event_spool_dir[128] = {'\0'};
  85 static char event_app[128] = {'\0'};
  86 static char db_family[128] = {'\0'};
  87 static char time_stamp_format[128] = {"%a %b %d, %Y @ %H:%M:%S %Z"};
  88
  89 /* Misc variables */
  90 static char event_file[14] = "/event-XXXXXX";
  91
  92 /*
  93 * Attempt to access a database variable and increment it,
  94 * provided that the user defined db-family in alarmreceiver.conf
  95 * The alarmreceiver app will write statistics to a few variables
  96 * in this family if it is defined. If the new key doesn't exist in the
  97 * family, then create it and set its value to 1.
  98 */
  99 static void database_increment( char *key )
 100 {
 101         int res = 0;
 102         unsigned v;
 103         char value[16];
 104
 105
 106         if (ast_strlen_zero(db_family))
 107                 return; /* If not defined, don't do anything */
 108
 109         res = ast_db_get(db_family, key, value, sizeof(value) - 1);
 110
 111         if (res) {
 112                 ast_verb(4, "AlarmReceiver: Creating database entry %s and setting to 1\n", key);
 113                 /* Guess we have to create it */
 114                 res = ast_db_put(db_family, key, "1");
 115                 return;
 116         }
 117
 118         sscanf(value, "%u", &v);
 119         v++;
 120
 121         ast_verb(4, "AlarmReceiver: New value for %s: %u\n", key, v);
 122
 123         snprintf(value, sizeof(value), "%u", v);
 124
 125         res = ast_db_put(db_family, key, value);
 126
 127         if (res)
 128                 ast_verb(4, "AlarmReceiver: database_increment write error\n");
 129
 130         return;
 131 }
 132
 133
 134 /*
 135 * Build a MuLaw data block for a single frequency tone
 136 */
 137 static void make_tone_burst(unsigned char *data, float freq, float loudness, int len, int *x)
 138 {
 139         int     i;
 140         float   val;
 141
 142         for (i = 0; i < len; i++) {
 143                 val = loudness * sin((freq * 2.0 * M_PI * (*x)++)/8000.0);
 144                 data[i] = AST_LIN2MU((int)val);
 145         }
 146
 147         /* wrap back around from 8000 */
 148
 149         if (*x >= 8000)
 150                 *x = 0;
 151         return;
 152 }
 153
 154 /*
 155 * Send a single tone burst for a specifed duration and frequency.
 156 * Returns 0 if successful
 157 */
 158 static int send_tone_burst(struct ast_channel *chan, float freq, int duration, int tldn)
 159 {
 160         int res = 0;
 161         int i = 0;
 162         int x = 0;
 163         struct ast_frame *f, wf;
 164
 165         struct {
 166                 unsigned char offset[AST_FRIENDLY_OFFSET];
 167                 unsigned char buf[640];
 168         } tone_block;
 169
 170         for (;;) {
 171
 172                 if (ast_waitfor(chan, -1) < 0) {
 173                         res = -1;
 174                         break;
 175                 }
 176
 177                 f = ast_read(chan);
 178                 if (!f) {
 179                         res = -1;
 180                         break;
 181                 }
 182
 183                 if (f->frametype == AST_FRAME_VOICE) {
 184                         wf.frametype = AST_FRAME_VOICE;
 185                         wf.subclass = AST_FORMAT_ULAW;
 186                         wf.offset = AST_FRIENDLY_OFFSET;
 187                         wf.mallocd = 0;
 188                         wf.data = tone_block.buf;
 189                         wf.datalen = f->datalen;
 190                         wf.samples = wf.datalen;
 191
 192                         make_tone_burst(tone_block.buf, freq, (float) tldn, wf.datalen, &x);
 193
 194                         i += wf.datalen / 8;
 195                         if (i > duration) {
 196                                 ast_frfree(f);
 197                                 break;
 198                         }
 199                         if (ast_write(chan, &wf)) {
 200                                 ast_verb(4, "AlarmReceiver: Failed to write frame on %s\n", chan->name);
 201                                 ast_log(LOG_WARNING, "AlarmReceiver Failed to write frame on %s\n",chan->name);
 202                                 res = -1;
 203                                 ast_frfree(f);
 204                                 break;
 205                         }
 206                 }
 207
 208                 ast_frfree(f);
 209         }
 210         return res;
 211 }
 212
 213 /*
 214 * Receive a string of DTMF digits where the length of the digit string is known in advance. Do not give preferential
 215 * treatment to any digit value, and allow separate time out values to be specified for the first digit and all subsequent
 216 * digits.
 217 *
 218 * Returns 0 if all digits successfully received.
 219 * Returns 1 if a digit time out occurred
 220 * Returns -1 if the caller hung up or there was a channel error.
 221 *
 222 */
 223 static int receive_dtmf_digits(struct ast_channel *chan, char *digit_string, int length, int fdto, int sdto)
 224 {
 225         int res = 0;
 226         int i = 0;
 227         int r;
 228         struct ast_frame *f;
 229         struct timeval lastdigittime;
 230
 231         lastdigittime = ast_tvnow();
 232         for (;;) {
 233                 /* if outa time, leave */
 234                 if (ast_tvdiff_ms(ast_tvnow(), lastdigittime) > ((i > 0) ? sdto : fdto)) {
 235                         ast_verb(4, "AlarmReceiver: DTMF Digit Timeout on %s\n", chan->name);
 236                         ast_debug(1,"AlarmReceiver: DTMF timeout on chan %s\n",chan->name);
 237                         res = 1;
 238                         break;
 239                 }
 240
 241                 if ((r = ast_waitfor(chan, -1) < 0)) {
 242                         ast_debug(1, "Waitfor returned %d\n", r);
 243                         continue;
 244                 }
 245
 246                 f = ast_read(chan);
 247
 248                 if (f == NULL) {
 249                         res = -1;
 250                         break;
 251                 }
 252
 253                 /* If they hung up, leave */
 254                 if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_HANGUP)) {
 255                         if (f->seqno) {
 256                                 chan->hangupcause = f->seqno;
 257                         }
 258                         ast_frfree(f);
 259                         res = -1;
 260                         break;
 261                 }
 262
 263                 /* if not DTMF, just do it again */
 264                 if (f->frametype != AST_FRAME_DTMF) {
 265                         ast_frfree(f);
 266                         continue;
 267                 }
 268
 269                 digit_string[i++] = f->subclass;  /* save digit */
 270
 271                 ast_frfree(f);
 272
 273                 /* If we have all the digits we expect, leave */
 274                 if(i >= length)
 275                         break;
 276
 277                 lastdigittime = ast_tvnow();
 278         }
 279
 280         digit_string[i] = '\0'; /* Nul terminate the end of the digit string */
 281         return res;
 282 }
 283
 284 /*
 285 * Write the metadata to the log file
 286 */
 287 static int write_metadata( FILE *logfile, char *signalling_type, struct ast_channel *chan)
 288 {
 289         int res = 0;
 290         struct timeval t;
 291         struct ast_tm now;
 292         char *cl,*cn;
 293         char workstring[80];
 294         char timestamp[80];
 295
 296         /* Extract the caller ID location */
 297         if (chan->cid.cid_num)
 298                 ast_copy_string(workstring, chan->cid.cid_num, sizeof(workstring));
 299         workstring[sizeof(workstring) - 1] = '\0';
 300
 301         ast_callerid_parse(workstring, &cn, &cl);
 302         if (cl)
 303                 ast_shrink_phone_number(cl);
 304
 305         /* Get the current time */
 306         t = ast_tvnow();
 307         ast_localtime(&t, &now, NULL);
 308
 309         /* Format the time */
 310         ast_strftime(timestamp, sizeof(timestamp), time_stamp_format, &now);
 311
 312         res = fprintf(logfile, "\n\n[metadata]\n\n");
 313
 314         if (res >= 0)
 315                 res = fprintf(logfile, "PROTOCOL=%s\n", signalling_type);
 316
 317         if (res >= 0)
 318                 res = fprintf(logfile, "CALLINGFROM=%s\n", (!cl) ? "<unknown>" : cl);
 319
 320         if (res >- 0)
 321                 res = fprintf(logfile, "CALLERNAME=%s\n", (!cn) ? "<unknown>" : cn);
 322
 323         if (res >= 0)
 324                 res = fprintf(logfile, "TIMESTAMP=%s\n\n", timestamp);
 325
 326         if (res >= 0)
 327                 res = fprintf(logfile, "[events]\n\n");
 328
 329         if (res < 0) {
 330                 ast_verb(3, "AlarmReceiver: can't write metadata\n");
 331                 ast_debug(1,"AlarmReceiver: can't write metadata\n");
 332         } else
 333                 res = 0;
 334
 335         return res;
 336 }
 337
 338 /*
 339 * Write a single event to the log file
 340 */
 341 static int write_event( FILE *logfile,  event_node_t *event)
 342 {
 343         int res = 0;
 344
 345         if (fprintf(logfile, "%s\n", event->data) < 0)
 346                 res = -1;
 347
 348         return res;
 349 }
 350
 351 /*
 352 * If we are configured to log events, do so here.
 353 *
 354 */
 355 static int log_events(struct ast_channel *chan,  char *signalling_type, event_node_t *event)
 356 {
 357
 358         int res = 0;
 359         char workstring[sizeof(event_spool_dir)+sizeof(event_file)] = "";
 360         int fd;
 361         FILE *logfile;
 362         event_node_t *elp = event;
 363
 364         if (!ast_strlen_zero(event_spool_dir)) {
 365
 366                 /* Make a template */
 367                 ast_copy_string(workstring, event_spool_dir, sizeof(workstring));
 368                 strncat(workstring, event_file, sizeof(workstring) - strlen(workstring) - 1);
 369
 370                 /* Make the temporary file */
 371                 fd = mkstemp(workstring);
 372
 373                 if (fd == -1) {
 374                         ast_verb(3, "AlarmReceiver: can't make temporary file\n");
 375                         ast_debug(1,"AlarmReceiver: can't make temporary file\n");
 376                         res = -1;
 377                 }
 378
 379                 if (!res) {
 380                         logfile = fdopen(fd, "w");
 381                         if (logfile) {
 382                                 /* Write the file */
 383                                 res = write_metadata(logfile, signalling_type, chan);
 384                                 if (!res)
 385                                         while ((!res) && (elp != NULL)) {
 386                                                 res = write_event(logfile, elp);
 387                                                 elp = elp->next;
 388                                         }
 389                                 if (!res) {
 390                                         if (fflush(logfile) == EOF)
 391                                                 res = -1;
 392                                         if (!res) {
 393                                                 if (fclose(logfile) == EOF)
 394                                                         res = -1;
 395                                         }
 396                                 }
 397                         } else
 398                                 res = -1;
 399                 }
 400         }
 401
 402         return res;
 403 }
 404
 405 /*
 406 * This function implements the logic to receive the Ademco contact ID  format.
 407 *
 408 * The function will return 0 when the caller hangs up, else a -1 if there was a problem.
 409 */
 410 static int receive_ademco_contact_id( struct ast_channel *chan, void *data, int fdto, int sdto, int tldn, event_node_t **ehead)
 411 {
 412         int i, j;
 413         int res = 0;
 414         int checksum;
 415         char event[17];
 416         event_node_t *enew, *elp;
 417         int got_some_digits = 0;
 418         int events_received = 0;
 419         int ack_retries = 0;
 420
 421         static char digit_map[15] = "0123456789*#ABC";
 422         static unsigned char digit_weights[15] = {10,1,2,3,4,5,6,7,8,9,11,12,13,14,15};
 423
 424         database_increment("calls-received");
 425
 426         /* Wait for first event */
 427         ast_verb(4, "AlarmReceiver: Waiting for first event from panel\n");
 428
 429         while (res >= 0) {
 430                 if (got_some_digits == 0) {
 431                         /* Send ACK tone sequence */
 432                         ast_verb(4, "AlarmReceiver: Sending 1400Hz 100ms burst (ACK)\n");
 433                         res = send_tone_burst(chan, 1400.0, 100, tldn);
 434                         if (!res)
 435                                 res = ast_safe_sleep(chan, 100);
 436                         if (!res) {
 437                                 ast_verb(4, "AlarmReceiver: Sending 2300Hz 100ms burst (ACK)\n");
 438                                 res = send_tone_burst(chan, 2300.0, 100, tldn);
 439                         }
 440                 }
 441                 if ( res >= 0)
 442                         res = receive_dtmf_digits(chan, event, sizeof(event) - 1, fdto, sdto);
 443                 if (res < 0) {
 444                         if (events_received == 0) {
 445                                 /* Hangup with no events received should be logged in the DB */
 446                                 database_increment("no-events-received");
 447                         } else {
 448                                 if (ack_retries) {
 449                                         ast_verb(4, "AlarmReceiver: ACK retries during this call: %d\n", ack_retries);
 450                                         database_increment("ack-retries");
 451                                 }
 452                         }
 453                         ast_verb(4, "AlarmReceiver: App exiting...\n");
 454                         res = -1;
 455                         break;
 456                 }
 457
 458                 if (res != 0) {
 459                         /* Didn't get all of the digits */
 460                         ast_verb(2, "AlarmReceiver: Incomplete string: %s, trying again...\n", event);
 461
 462                         if (!got_some_digits) {
 463                                 got_some_digits = (!ast_strlen_zero(event)) ? 1 : 0;
 464                                 ack_retries++;
 465                         }
 466                         continue;
 467                 }
 468
 469                 got_some_digits = 1;
 470
 471                 ast_verb(2, "AlarmReceiver: Received Event %s\n", event);
 472                 ast_debug(1, "AlarmReceiver: Received event: %s\n", event);
 473
 474                 /* Calculate checksum */
 475
 476                 for (j = 0, checksum = 0; j < 16; j++) {
 477                         for (i = 0; i < sizeof(digit_map); i++) {
 478                                 if (digit_map[i] == event[j])
 479                                         break;
 480                         }
 481
 482                         if (i == 16)
 483                                 break;
 484
 485                         checksum += digit_weights[i];
 486                 }
 487                 if (i == 16) {
 488                         ast_verb(2, "AlarmReceiver: Bad DTMF character %c, trying again\n", event[j]);
 489                         continue; /* Bad character */
 490                 }
 491
 492                 /* Checksum is mod(15) of the total */
 493
 494                 checksum = checksum % 15;
 495
 496                 if (checksum) {
 497                         database_increment("checksum-errors");
 498                         ast_verb(2, "AlarmReceiver: Nonzero checksum\n");
 499                         ast_debug(1, "AlarmReceiver: Nonzero checksum\n");
 500                         continue;
 501                 }
 502
 503                 /* Check the message type for correctness */
 504
 505                 if (strncmp(event + 4, "18", 2)) {
 506                         if (strncmp(event + 4, "98", 2)) {
 507                                 database_increment("format-errors");
 508                                 ast_verb(2, "AlarmReceiver: Wrong message type\n");
 509                                 ast_debug(1, "AlarmReceiver: Wrong message type\n");
 510                         continue;
 511                         }
 512                 }
 513
 514                 events_received++;
 515
 516                 /* Queue the Event */
 517                 if (!(enew = ast_calloc(1, sizeof(*enew)))) {
 518                         res = -1;
 519                         break;
 520                 }
 521
 522                 enew->next = NULL;
 523                 ast_copy_string(enew->data, event, sizeof(enew->data));
 524
 525                 /*
 526                 * Insert event onto end of list
 527                 */
 528                 if (*ehead == NULL)
 529                         *ehead = enew;
 530                 else {
 531                         for(elp = *ehead; elp->next != NULL; elp = elp->next)
 532                         ;
 533                         elp->next = enew;
 534                 }
 535
 536                 if (res > 0)
 537                         res = 0;
 538
 539                 /* Let the user have the option of logging the single event before sending the kissoff tone */
 540                 if ((res == 0) && (log_individual_events))
 541                         res = log_events(chan, ADEMCO_CONTACT_ID, enew);
 542                 /* Wait 200 msec before sending kissoff */
 543                 if (res == 0)
 544                         res = ast_safe_sleep(chan, 200);
 545
 546                 /* Send the kissoff tone */
 547                 if (res == 0)
 548                         res = send_tone_burst(chan, 1400.0, 900, tldn);
 549         }
 550
 551         return res;
 552 }
 553
 554 /*
 555 * This is the main function called by Asterisk Core whenever the App is invoked in the extension logic.
 556 * This function will always return 0.
 557 */
 558 static int alarmreceiver_exec(struct ast_channel *chan, void *data)
 559 {
 560         int res = 0;
 561         event_node_t *elp, *efree;
 562         char signalling_type[64] = "";
 563         event_node_t *event_head = NULL;
 564
 565         /* Set write and read formats to ULAW */
 566         ast_verb(4, "AlarmReceiver: Setting read and write formats to ULAW\n");
 567
 568         if (ast_set_write_format(chan,AST_FORMAT_ULAW)) {
 569                 ast_log(LOG_WARNING, "AlarmReceiver: Unable to set write format to Mu-law on %s\n",chan->name);
 570                 return -1;
 571         }
 572
 573         if (ast_set_read_format(chan,AST_FORMAT_ULAW)) {
 574                 ast_log(LOG_WARNING, "AlarmReceiver: Unable to set read format to Mu-law on %s\n",chan->name);
 575                 return -1;
 576         }
 577
 578         /* Set default values for this invocation of the application */
 579         ast_copy_string(signalling_type, ADEMCO_CONTACT_ID, sizeof(signalling_type));
 580
 581         /* Answer the channel if it is not already */
 582         ast_verb(4, "AlarmReceiver: Answering channel\n");
 583         if (chan->_state != AST_STATE_UP) {
 584                 if ((res = ast_answer(chan)))
 585                         return -1;
 586         }
 587
 588         /* Wait for the connection to settle post-answer */
 589         ast_verb(4, "AlarmReceiver: Waiting for connection to stabilize\n");
 590         res = ast_safe_sleep(chan, 1250);
 591
 592         /* Attempt to receive the events */
 593         if (!res) {
 594                 /* Determine the protocol to receive in advance */
 595                 /* Note: Ademco contact is the only one supported at this time */
 596                 /* Others may be added later */
 597                 if(!strcmp(signalling_type, ADEMCO_CONTACT_ID))
 598                         receive_ademco_contact_id(chan, data, fdtimeout, sdtimeout, toneloudness, &event_head);
 599                 else
 600                         res = -1;
 601         }
 602
 603         /* Events queued by receiver, write them all out here if so configured */
 604         if ((!res) && (log_individual_events == 0))
 605                 res = log_events(chan, signalling_type, event_head);
 606
 607         /*
 608         * Do we exec a command line at the end?
 609         */
 610         if ((!res) && (!ast_strlen_zero(event_app)) && (event_head)) {
 611                 ast_debug(1,"Alarmreceiver: executing: %s\n", event_app);
 612                 ast_safe_system(event_app);
 613         }
 614
 615         /*
 616         * Free up the data allocated in our linked list
 617         */
 618         for (elp = event_head; (elp != NULL);) {
 619                 efree = elp;
 620                 elp = elp->next;
 621                 ast_free(efree);
 622         }
 623
 624         return 0;
 625 }
 626
 627 /*
 628 * Load the configuration from the configuration file
 629 */
 630 static int load_config(void)
 631 {
 632         struct ast_config *cfg;
 633         const char *p;
 634         struct ast_flags config_flags = { 0 };
 635
 636         /* Read in the config file */
 637         cfg = ast_config_load(ALMRCV_CONFIG, config_flags);
 638
 639         if (!cfg) {
 640                 ast_verb(4, "AlarmReceiver: No config file\n");
 641                 return 0;
 642         } else {
 643                 p = ast_variable_retrieve(cfg, "general", "eventcmd");
 644                 if (p) {
 645                         ast_copy_string(event_app, p, sizeof(event_app));
 646                         event_app[sizeof(event_app) - 1] = '\0';
 647                 }
 648                 p = ast_variable_retrieve(cfg, "general", "loudness");
 649                 if (p) {
 650                         toneloudness = atoi(p);
 651                         if(toneloudness < 100)
 652                                 toneloudness = 100;
 653                         if(toneloudness > 8192)
 654                                 toneloudness = 8192;
 655                 }
 656                 p = ast_variable_retrieve(cfg, "general", "fdtimeout");
 657                 if (p) {
 658                         fdtimeout = atoi(p);
 659                         if(fdtimeout < 1000)
 660                                 fdtimeout = 1000;
 661                         if(fdtimeout > 10000)
 662                                 fdtimeout = 10000;
 663                 }
 664
 665                 p = ast_variable_retrieve(cfg, "general", "sdtimeout");
 666                 if (p) {
 667                         sdtimeout = atoi(p);
 668                         if(sdtimeout < 110)
 669                                 sdtimeout = 110;
 670                         if(sdtimeout > 4000)
 671                                 sdtimeout = 4000;
 672                 }
 673
 674                 p = ast_variable_retrieve(cfg, "general", "logindividualevents");
 675                 if (p)
 676                         log_individual_events = ast_true(p);
 677
 678                 p = ast_variable_retrieve(cfg, "general", "eventspooldir");
 679                 if (p) {
 680                         ast_copy_string(event_spool_dir, p, sizeof(event_spool_dir));
 681                         event_spool_dir[sizeof(event_spool_dir) - 1] = '\0';
 682                 }
 683
 684                 p = ast_variable_retrieve(cfg, "general", "timestampformat");
 685                 if (p) {
 686                         ast_copy_string(time_stamp_format, p, sizeof(time_stamp_format));
 687                         time_stamp_format[sizeof(time_stamp_format) - 1] = '\0';
 688                 }
 689
 690                 p = ast_variable_retrieve(cfg, "general", "db-family");
 691                 if (p) {
 692                         ast_copy_string(db_family, p, sizeof(db_family));
 693                         db_family[sizeof(db_family) - 1] = '\0';
 694                 }
 695                 ast_config_destroy(cfg);
 696         }
 697         return 1;
 698 }
 699
 700 /*
 701 * These functions are required to implement an Asterisk App.
 702 */
 703 static int unload_module(void)
 704 {
 705         return ast_unregister_application(app);
 706 }
 707
 708 static int load_module(void)
 709 {
 710         if (load_config()) {
 711                 if (ast_register_application(app, alarmreceiver_exec, synopsis, descrip))
 712                         return AST_MODULE_LOAD_FAILURE;
 713                 return AST_MODULE_LOAD_SUCCESS;
 714         } else
 715                 return AST_MODULE_LOAD_DECLINE;
 716 }
 717
 718 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Alarm Receiver for Asterisk");