main/enum.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * Funding provided by nic.at
   9  *
  10  * See http://www.asterisk.org for more information about
  11  * the Asterisk project. Please do not directly contact
  12  * any of the maintainers of this project for assistance;
  13  * the project provides a web site, mailing lists and IRC
  14  * channels for your use.
  15  *
  16  * This program is free software, distributed under the terms of
  17  * the GNU General Public License Version 2. See the LICENSE file
  18  * at the top of the source tree.
  19  */
  20
  21 /*! \file
  22  *
  23  * \brief ENUM Support for Asterisk
  24  *
  25  * \author Mark Spencer <markster@digium.com>
  26  *
  27  * \arg Funding provided by nic.at
  28  *
  29  * \par Enum standards
  30  *
  31  * - NAPTR records: http://ietf.nri.reston.va.us/rfc/rfc2915.txt
  32  * - DNS SRV records: http://www.ietf.org/rfc/rfc2782.txt
  33  * - ENUM http://www.ietf.org/rfc/rfc3761.txt
  34  * - ENUM for H.323: http://www.ietf.org/rfc/rfc3762.txt
  35  * - ENUM SIP: http://www.ietf.org/rfc/rfc3764.txt
  36  * - IANA ENUM Services: http://www.iana.org/assignments/enum-services
  37  *
  38  * \par Possible improvement
  39  * \todo Implement a caching mechanism for multile enum lookups
  40  * - See http://bugs.digium.com/view.php?id=6739
  41  */
  42
  43 #include "asterisk.h"
  44
  45 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  46
  47 #include <sys/types.h>
  48 #include <sys/socket.h>
  49 #include <netinet/in.h>
  50 #include <arpa/nameser.h>
  51 #if __APPLE_CC__ >= 1495
  52 #include <arpa/nameser_compat.h>
  53 #endif
  54 #include <resolv.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <ctype.h>
  58 #include <regex.h>
  59 #include <unistd.h>
  60 #include <errno.h>
  61
  62 #include "asterisk/logger.h"
  63 #include "asterisk/options.h"
  64 #include "asterisk/enum.h"
  65 #include "asterisk/dns.h"
  66 #include "asterisk/channel.h"
  67 #include "asterisk/config.h"
  68 #include "asterisk/utils.h"
  69
  70 #ifdef __APPLE__
  71 #undef T_NAPTR
  72 #define T_NAPTR 35
  73 #endif
  74
  75 #ifdef __APPLE__
  76 #undef T_TXT
  77 #define T_TXT 16
  78 #endif
  79
  80 #define TOPLEV "e164.arpa."     /*!< The IETF Enum standard root, managed by the ITU */
  81
  82 /* Linked list from config file */
  83 static struct enum_search {
  84         char toplev[512];
  85         struct enum_search *next;
  86 } *toplevs;
  87
  88 static int enumver;
  89
  90 AST_MUTEX_DEFINE_STATIC(enumlock);
  91
  92 struct naptr {
  93         unsigned short order;
  94         unsigned short pref;
  95 } __attribute__ ((__packed__));
  96
  97 /*! \brief Parse NAPTR record information elements */
  98 static unsigned int parse_ie(char *data, unsigned int maxdatalen, unsigned char *src, unsigned int srclen)
  99 {
 100         unsigned int len, olen;
 101
 102         len = olen = (unsigned int) src[0];
 103         src++;
 104         srclen--;
 105
 106         if (len > srclen) {
 107                 ast_log(LOG_WARNING, "ENUM parsing failed: Wanted %d characters, got %d\n", len, srclen);
 108                 return -1;
 109         }
 110
 111         if (len > maxdatalen)
 112                 len = maxdatalen;
 113         memcpy(data, src, len);
 114
 115         return olen + 1;
 116 }
 117
 118 /*! \brief Parse DNS NAPTR record used in ENUM ---*/
 119 static int parse_naptr(char *dst, int dstsize, char *tech, int techsize, unsigned char *answer, int len, char *naptrinput)
 120 {
 121         char tech_return[80];
 122         unsigned char *oanswer = answer;
 123         char flags[512] = "";
 124         char services[512] = "";
 125         char *p;
 126         char regexp[512] = "";
 127         char repl[512] = "";
 128         char temp[512] = "";
 129         char delim;
 130         char *delim2;
 131         char *pattern, *subst, *d;
 132         int res;
 133         int regexp_len, size, backref;
 134         int d_len = sizeof(temp) - 1;
 135         regex_t preg;
 136         regmatch_t pmatch[9];
 137
 138         tech_return[0] = '\0';
 139
 140         dst[0] = '\0';
 141
 142         if (len < sizeof(struct naptr)) {
 143                 ast_log(LOG_WARNING, "NAPTR record length too short\n");
 144                 return -1;
 145         }
 146         answer += sizeof(struct naptr);
 147         len -= sizeof(struct naptr);
 148         if ((res = parse_ie(flags, sizeof(flags) - 1, answer, len)) < 0) {
 149                 ast_log(LOG_WARNING, "Failed to get flags from NAPTR record\n");
 150                 return -1;
 151         } else {
 152                 answer += res;
 153                 len -= res;
 154         }
 155         if ((res = parse_ie(services, sizeof(services) - 1, answer, len)) < 0) {
 156                 ast_log(LOG_WARNING, "Failed to get services from NAPTR record\n");
 157                 return -1;
 158         } else {
 159                 answer += res;
 160                 len -= res;
 161         }
 162         if ((res = parse_ie(regexp, sizeof(regexp) - 1, answer, len)) < 0) {
 163                 ast_log(LOG_WARNING, "Failed to get regexp from NAPTR record\n");
 164                 return -1;
 165         } else {
 166                 answer += res;
 167                 len -= res;
 168         }
 169
 170         if ((res = dn_expand(oanswer, answer + len, answer, repl, sizeof(repl) - 1)) < 0) {
 171                 ast_log(LOG_WARNING, "Failed to expand hostname\n");
 172                 return -1;
 173         }
 174
 175         if (option_debug > 2)   /* Advanced NAPTR debugging */
 176                 ast_log(LOG_DEBUG, "NAPTR input='%s', flags='%s', services='%s', regexp='%s', repl='%s'\n",
 177                         naptrinput, flags, services, regexp, repl);
 178
 179         if (tolower(flags[0]) != 'u') {
 180                 ast_log(LOG_WARNING, "NAPTR Flag must be 'U' or 'u'.\n");
 181                 return -1;
 182         }
 183
 184         p = strstr(services, "e2u+");
 185         if (p == NULL)
 186                 p = strstr(services, "E2U+");
 187         if (p){
 188                 p = p + 4;
 189                 if (strchr(p, ':')){
 190                         p = strchr(p, ':') + 1;
 191                 }
 192                 ast_copy_string(tech_return, p, sizeof(tech_return));
 193         } else {
 194
 195                 p = strstr(services, "+e2u");
 196                 if (p == NULL)
 197                         p = strstr(services, "+E2U");
 198                 if (p) {
 199                         *p = 0;
 200                         p = strchr(services, ':');
 201                         if (p)
 202                                 *p = 0;
 203                         ast_copy_string(tech_return, services, sizeof(tech_return));
 204                 }
 205         }
 206
 207         /* DEDBUGGING STUB
 208         ast_copy_string(regexp, "!^\\+43(.*)$!\\1@bla.fasel!", sizeof(regexp) - 1);
 209         */
 210
 211         regexp_len = strlen(regexp);
 212         if (regexp_len < 7) {
 213                 ast_log(LOG_WARNING, "Regex too short to be meaningful.\n");
 214                 return -1;
 215         }
 216
 217
 218         delim = regexp[0];
 219         delim2 = strchr(regexp + 1, delim);
 220         if ((delim2 == NULL) || (regexp[regexp_len-1] != delim)) {
 221                 ast_log(LOG_WARNING, "Regex delimiter error (on \"%s\").\n",regexp);
 222                 return -1;
 223         }
 224
 225         pattern = regexp + 1;
 226         *delim2 = 0;
 227         subst   = delim2 + 1;
 228         regexp[regexp_len-1] = 0;
 229
 230 /*
 231  * now do the regex wizardry.
 232  */
 233
 234         if (regcomp(&preg, pattern, REG_EXTENDED | REG_NEWLINE)) {
 235                 ast_log(LOG_WARNING, "NAPTR Regex compilation error (regex = \"%s\").\n",regexp);
 236                 return -1;
 237         }
 238
 239         if (preg.re_nsub > 9) {
 240                 ast_log(LOG_WARNING, "NAPTR Regex compilation error: too many subs.\n");
 241                 regfree(&preg);
 242                 return -1;
 243         }
 244
 245         if (regexec(&preg, naptrinput, 9, pmatch, 0)) {
 246                 ast_log(LOG_WARNING, "NAPTR Regex match failed.\n");
 247                 regfree(&preg);
 248                 return -1;
 249         }
 250         regfree(&preg);
 251
 252         d = temp;
 253         d_len--;
 254         while (*subst && (d_len > 0)) {
 255                 if ((subst[0] == '\\') && isdigit(subst[1]) && (pmatch[subst[1]-'0'].rm_so != -1)) {
 256                         backref = subst[1]-'0';
 257                         size = pmatch[backref].rm_eo - pmatch[backref].rm_so;
 258                         if (size > d_len) {
 259                                 ast_log(LOG_WARNING, "Not enough space during NAPTR regex substitution.\n");
 260                                 return -1;
 261                                 }
 262                         memcpy(d, naptrinput + pmatch[backref].rm_so, size);
 263                         d += size;
 264                         d_len -= size;
 265                         subst += 2;
 266                 } else if (isprint(*subst)) {
 267                         *d++ = *subst++;
 268                         d_len--;
 269                 } else {
 270                         ast_log(LOG_WARNING, "Error during regex substitution.\n");
 271                         return -1;
 272                 }
 273         }
 274         *d = 0;
 275         ast_copy_string(dst, temp, dstsize);
 276         dst[dstsize - 1] = '\0';
 277
 278         if (*tech != '\0'){ /* check if it is requested NAPTR */
 279                 if (!strncasecmp(tech, "ALL", techsize)){
 280                         return 1; /* return or count any RR */
 281                 }
 282                 if (!strncasecmp(tech_return, tech, sizeof(tech_return)<techsize?sizeof(tech_return):techsize)){
 283                         ast_copy_string(tech, tech_return, techsize);
 284                         return 1; /* we got out RR */
 285                 } else { /* go to the next RR in the DNS answer */
 286                         return 0;
 287                 }
 288         }
 289
 290         /* tech was not specified, return first parsed RR */
 291         ast_copy_string(tech, tech_return, techsize);
 292
 293         return 1;
 294 }
 295
 296 /* do not return requested value, just count RRs and return thei number in dst */
 297 #define ENUMLOOKUP_OPTIONS_COUNT       1
 298
 299 struct enum_naptr_rr {
 300         struct naptr naptr; /* order and preference of RR */
 301         char *result; /* result of naptr parsing,e.g.: tel:+5553 */
 302         char *tech; /* Technology (from URL scheme) */
 303         int sort_pos; /* sort position */
 304 };
 305
 306 struct enum_context {
 307         char *dst;      /* Destination part of URL from ENUM */
 308         int dstlen;     /* Length */
 309         char *tech;     /* Technology (from URL scheme) */
 310         int techlen;    /* Length */
 311         char *txt;      /* TXT record in TXT lookup */
 312         int txtlen;     /* Length */
 313         char *naptrinput;       /* The number to lookup */
 314         int position; /* used as counter for RRs or specifies position of required RR */
 315         int options; /* options , see ENUMLOOKUP_OPTIONS_* defined above */
 316         struct enum_naptr_rr *naptr_rrs; /* array of parsed NAPTR RRs */
 317         int naptr_rrs_count; /* Size of array naptr_rrs */
 318 };
 319
 320 /*! \brief Callback for TXT record lookup */
 321 static int txt_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
 322 {
 323         struct enum_context *c = (struct enum_context *)context;
 324
 325         if (answer == NULL) {
 326                 c->txt = NULL;
 327                 c->txtlen = 0;
 328                 return 0;
 329         }
 330
 331         /* skip over first byte, as for some reason it's a vertical tab character */
 332         answer += 1;
 333         len -= 1;
 334
 335         /* answer is not null-terminated, but should be */
 336         /* this is safe to do, as answer has extra bytes on the end we can
 337          * safely overwrite with a null */
 338         answer[len] = '\0';
 339         /* now increment len so that len includes the null, so that we can
 340          * compare apples to apples */
 341         len +=1;
 342
 343         /* finally, copy the answer into c->txt */
 344         ast_copy_string(c->txt, (const char *) answer, len < c->txtlen ? len : (c->txtlen));
 345
 346         /* just to be safe, let's make sure c->txt is null terminated */
 347         c->txt[(c->txtlen)-1] = '\0';
 348
 349         return 1;
 350 }
 351
 352 /*! \brief Callback from ENUM lookup function */
 353 static int enum_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
 354 {
 355         struct enum_context *c = context;
 356         void *p = NULL;
 357         int res;
 358
 359         res = parse_naptr(c->dst, c->dstlen, c->tech, c->techlen, answer, len, c->naptrinput);
 360
 361         if (res < 0) {
 362                 ast_log(LOG_WARNING, "Failed to parse naptr :(\n");
 363                 return -1;
 364         } else if (res > 0 && !ast_strlen_zero(c->dst)){ /* ok, we got needed NAPTR */
 365                 if (c->options & ENUMLOOKUP_OPTIONS_COUNT){ /* counting RRs */
 366                         c->position++;
 367                         snprintf(c->dst, c->dstlen, "%d", c->position);
 368                 } else  {
 369                         if ((p = ast_realloc(c->naptr_rrs, sizeof(*c->naptr_rrs) * (c->naptr_rrs_count + 1)))) {
 370                                 c->naptr_rrs = p;
 371                                 memcpy(&c->naptr_rrs[c->naptr_rrs_count].naptr, answer, sizeof(c->naptr_rrs->naptr));
 372                                 c->naptr_rrs[c->naptr_rrs_count].result = strdup(c->dst);
 373                                 c->naptr_rrs[c->naptr_rrs_count].tech = strdup(c->tech);
 374                                 c->naptr_rrs[c->naptr_rrs_count].sort_pos = c->naptr_rrs_count;
 375                                 c->naptr_rrs_count++;
 376                         }
 377                         c->dst[0] = 0;
 378                 }
 379                 return 0;
 380         }
 381
 382         if (c->options & ENUMLOOKUP_OPTIONS_COUNT)      { /* counting RRs */
 383                 snprintf(c->dst, c->dstlen, "%d", c->position);
 384         }
 385
 386         return 0;
 387 }
 388
 389 /*! \brief ENUM lookup */
 390 int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int dstlen, char *tech, int techlen, char* suffix, char* options, unsigned int record)
 391 {
 392         struct enum_context context;
 393         char tmp[259 + 512];
 394         char naptrinput[512];
 395         int pos = strlen(number) - 1;
 396         int newpos = 0;
 397         int ret = -1;
 398         struct enum_search *s = NULL;
 399         int version = -1;
 400         /* for ISN rewrite */
 401         char *p1 = NULL;
 402         char *p2 = NULL;
 403         int k = 0;
 404         int i = 0;
 405         int z = 0;
 406
 407         ast_copy_string(naptrinput, number[0] == 'n' ? number+1 : number, sizeof(naptrinput));
 408
 409         context.naptrinput = naptrinput;        /* The number */
 410         context.dst = dst;                      /* Return string */
 411         context.dstlen = dstlen;
 412         context.tech = tech;
 413         context.techlen = techlen;
 414         context.options = 0;
 415         context.position = record;
 416         context.naptr_rrs = NULL;
 417         context.naptr_rrs_count = 0;
 418
 419         if (options != NULL) {
 420                 if (*options == 'c') {
 421                         context.options = ENUMLOOKUP_OPTIONS_COUNT;
 422                         context.position = 0;
 423                 }
 424         }
 425
 426         ast_log(LOG_DEBUG, "ast_get_enum(): n='%s', tech='%s', suffix='%s', options='%d', record='%d'\n",
 427                         number, tech, suffix, context.options, context.position);
 428
 429         if (pos > 128)
 430                 pos = 128;
 431
 432         /* ISN rewrite */
 433         p1 = strchr(number, '*');
 434
 435         if (number[0] == 'n') { /* do not perform ISN rewrite ('n' is testing flag) */
 436                 p1 = NULL;
 437                 k = 1; /* strip 'n' from number */
 438         }
 439
 440         if (p1 != NULL) {
 441                 p2 = p1+1;
 442                 while (p1 > number){
 443                         p1--;
 444                         tmp[newpos++] = *p1;
 445                         tmp[newpos++] = '.';
 446                 }
 447                 if (*p2) {
 448                         while(*p2 && newpos < 128){
 449                                 tmp[newpos++] = *p2;
 450                                 p2++;
 451                         }
 452                         tmp[newpos++] = '.';
 453                 }
 454
 455         } else {
 456                 while (pos >= k) {
 457                         if (isdigit(number[pos])) {
 458                                 tmp[newpos++] = number[pos];
 459                                 tmp[newpos++] = '.';
 460                         }
 461                         pos--;
 462                 }
 463         }
 464
 465         if (chan && ast_autoservice_start(chan) < 0)
 466                 return -1;
 467
 468         if(suffix) {
 469                 ast_copy_string(tmp + newpos, suffix, sizeof(tmp) - newpos);
 470                 ret = ast_search_dns(&context, tmp, C_IN, T_NAPTR, enum_callback);
 471                 ast_log(LOG_DEBUG, "ast_get_enum: ast_search_dns(%s) returned %d\n", tmp, ret);
 472         } else {
 473                 ret = -1;               /* this is actually dead code since the demise of app_enum.c */
 474                 for (;;) {
 475                         ast_mutex_lock(&enumlock);
 476                         if (version != enumver) {
 477                                 /* Ooh, a reload... */
 478                                 s = toplevs;
 479                                 version = enumver;
 480                         } else {
 481                                 s = s->next;
 482                         }
 483                         ast_mutex_unlock(&enumlock);
 484
 485                         if (!s)
 486                                 break;
 487
 488                         ast_copy_string(tmp + newpos, s->toplev, sizeof(tmp) - newpos);
 489                         ret = ast_search_dns(&context, tmp, C_IN, T_NAPTR, enum_callback);
 490                         ast_log(LOG_DEBUG, "ast_get_enum: ast_search_dns(%s) returned %d\n", tmp, ret);
 491                         if (ret > 0)
 492                                 break;
 493                 }
 494         }
 495
 496         if (ret < 0) {
 497                 ast_log(LOG_DEBUG, "No such number found: %s (%s)\n", tmp, strerror(errno));
 498                 strcpy(dst, "0");
 499                 ret = 0;
 500         }
 501
 502         if (context.naptr_rrs_count >= context.position && ! (context.options & ENUMLOOKUP_OPTIONS_COUNT)) {
 503                 /* sort array by NAPTR order/preference */
 504                 for (k = 0; k < context.naptr_rrs_count; k++) {
 505                         for (i = 0; i < context.naptr_rrs_count; i++) {
 506                                 /* use order first and then preference to compare */
 507                                 if ((ntohs(context.naptr_rrs[k].naptr.order) < ntohs(context.naptr_rrs[i].naptr.order)
 508                                                 && context.naptr_rrs[k].sort_pos > context.naptr_rrs[i].sort_pos)
 509                                         || (ntohs(context.naptr_rrs[k].naptr.order) > ntohs(context.naptr_rrs[i].naptr.order)
 510                                                 && context.naptr_rrs[k].sort_pos < context.naptr_rrs[i].sort_pos)){
 511                                         z = context.naptr_rrs[k].sort_pos;
 512                                         context.naptr_rrs[k].sort_pos = context.naptr_rrs[i].sort_pos;
 513                                         context.naptr_rrs[i].sort_pos = z;
 514                                         continue;
 515                                 }
 516                                 if (ntohs(context.naptr_rrs[k].naptr.order) == ntohs(context.naptr_rrs[i].naptr.order)) {
 517                                         if ((ntohs(context.naptr_rrs[k].naptr.pref) < ntohs(context.naptr_rrs[i].naptr.pref)
 518                                                         && context.naptr_rrs[k].sort_pos > context.naptr_rrs[i].sort_pos)
 519                                                 || (ntohs(context.naptr_rrs[k].naptr.pref) > ntohs(context.naptr_rrs[i].naptr.pref)
 520                                                         && context.naptr_rrs[k].sort_pos < context.naptr_rrs[i].sort_pos)){
 521                                                 z = context.naptr_rrs[k].sort_pos;
 522                                                 context.naptr_rrs[k].sort_pos = context.naptr_rrs[i].sort_pos;
 523                                                 context.naptr_rrs[i].sort_pos = z;
 524                                         }
 525                                 }
 526                         }
 527                 }
 528                 for (k = 0; k < context.naptr_rrs_count; k++) {
 529                         if (context.naptr_rrs[k].sort_pos == context.position-1) {
 530                                 ast_copy_string(context.dst, context.naptr_rrs[k].result, dstlen);
 531                                 ast_copy_string(context.tech, context.naptr_rrs[k].tech, techlen);
 532                                 break;
 533                         }
 534                 }
 535         } else if (!(context.options & ENUMLOOKUP_OPTIONS_COUNT)) {
 536                 context.dst[0] = 0;
 537         }
 538         if (chan)
 539                 ret |= ast_autoservice_stop(chan);
 540
 541         for (k = 0; k < context.naptr_rrs_count; k++) {
 542                 free(context.naptr_rrs[k].result);
 543                 free(context.naptr_rrs[k].tech);
 544         }
 545
 546         free(context.naptr_rrs);
 547
 548         return ret;
 549 }
 550
 551 /*! \brief Get TXT record from DNS.
 552         Really has nothing to do with enum, but anyway...
 553  */
 554 int ast_get_txt(struct ast_channel *chan, const char *number, char *dst, int dstlen, char *tech, int techlen, char *txt, int txtlen)
 555 {
 556         struct enum_context context;
 557         char tmp[259 + 512];
 558         char naptrinput[512] = "+";
 559         int pos = strlen(number) - 1;
 560         int newpos = 0;
 561         int ret = -1;
 562         struct enum_search *s = NULL;
 563         int version = -1;
 564
 565         strncat(naptrinput, number, sizeof(naptrinput) - 2);
 566
 567         context.naptrinput = naptrinput;
 568         context.dst = dst;
 569         context.dstlen = dstlen;
 570         context.tech = tech;
 571         context.techlen = techlen;
 572         context.txt = txt;
 573         context.txtlen = txtlen;
 574
 575         if (pos > 128)
 576                 pos = 128;
 577         while (pos >= 0) {
 578                 tmp[newpos++] = number[pos--];
 579                 tmp[newpos++] = '.';
 580         }
 581
 582         if (chan && ast_autoservice_start(chan) < 0)
 583                 return -1;
 584
 585         for (;;) {
 586                 ast_mutex_lock(&enumlock);
 587                 if (version != enumver) {
 588                         /* Ooh, a reload... */
 589                         s = toplevs;
 590                         version = enumver;
 591                 } else {
 592                         s = s->next;
 593                 }
 594                 if (s) {
 595                         ast_copy_string(tmp + newpos, s->toplev, sizeof(tmp) - newpos);
 596                 }
 597                 ast_mutex_unlock(&enumlock);
 598                 if (!s)
 599                         break;
 600
 601                 ret = ast_search_dns(&context, tmp, C_IN, T_TXT, txt_callback);
 602                 if (ret > 0)
 603                         break;
 604         }
 605         if (ret < 0) {
 606                 if (option_debug > 1)
 607                         ast_log(LOG_DEBUG, "No such number found in ENUM: %s (%s)\n", tmp, strerror(errno));
 608                 ret = 0;
 609         }
 610         if (chan)
 611                 ret |= ast_autoservice_stop(chan);
 612         return ret;
 613 }
 614
 615 /*! \brief Add enum tree to linked list */
 616 static struct enum_search *enum_newtoplev(char *s)
 617 {
 618         struct enum_search *tmp;
 619
 620         if ((tmp = ast_calloc(1, sizeof(*tmp)))) {
 621                 ast_copy_string(tmp->toplev, s, sizeof(tmp->toplev));
 622         }
 623         return tmp;
 624 }
 625
 626 /*! \brief Initialize the ENUM support subsystem */
 627 int ast_enum_init(void)
 628 {
 629         struct ast_config *cfg;
 630         struct enum_search *s, *sl;
 631         struct ast_variable *v;
 632
 633         /* Destroy existing list */
 634         ast_mutex_lock(&enumlock);
 635         s = toplevs;
 636         while(s) {
 637                 sl = s;
 638                 s = s->next;
 639                 free(sl);
 640         }
 641         toplevs = NULL;
 642         cfg = ast_config_load("enum.conf");
 643         if (cfg) {
 644                 sl = NULL;
 645                 v = ast_variable_browse(cfg, "general");
 646                 while(v) {
 647                         if (!strcasecmp(v->name, "search")) {
 648                                 s = enum_newtoplev(v->value);
 649                                 if (s) {
 650                                         if (sl)
 651                                                 sl->next = s;
 652                                         else
 653                                                 toplevs = s;
 654                                         sl = s;
 655                                 }
 656                         }
 657                         v = v->next;
 658                 }
 659                 ast_config_destroy(cfg);
 660         } else {
 661                 toplevs = enum_newtoplev(TOPLEV);
 662         }
 663         enumver++;
 664         ast_mutex_unlock(&enumlock);
 665         return 0;
 666 }
 667
 668 int ast_enum_reload(void)
 669 {
 670         return ast_enum_init();
 671 }