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 <sys/types.h>
  44 #include <sys/socket.h>
  45 #include <netinet/in.h>
  46 #include <arpa/nameser.h>
  47 #if __APPLE_CC__ >= 1495
  48 #include <arpa/nameser_compat.h>
  49 #endif
  50 #include <resolv.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <ctype.h>
  54 #include <regex.h>
  55 #include <unistd.h>
  56 #include <errno.h>
  57
  58 #include "asterisk.h"
  59
  60 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  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 = 0;
  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 int parse_ie(char *data, int maxdatalen, char *src, int srclen)
  99 {
 100         int len, olen;
 101
 102         len = olen = (int)src[0];
 103         src++;
 104         srclen--;
 105         if (len > srclen || len < 0 ) {
 106                 ast_log(LOG_WARNING, "ENUM parsing failed: Wanted %d characters, got %d\n", len, srclen);
 107                 return -1;
 108         }
 109         if (len > maxdatalen)
 110                 len = maxdatalen;
 111         memcpy(data, src, len);
 112         return olen + 1;
 113 }
 114
 115 /*! \brief Parse DNS NAPTR record used in ENUM ---*/
 116 static int parse_naptr(char *dst, int dstsize, char *tech, int techsize, char *answer, int len, char *naptrinput)
 117 {
 118
 119         char tech_return[80];
 120         char *oanswer = answer;
 121         char flags[512] = "";
 122         char services[512] = "";
 123         char *p;
 124         char regexp[512] = "";
 125         char repl[512] = "";
 126         char temp[512] = "";
 127         char delim;
 128         char *delim2;
 129         char *pattern, *subst, *d;
 130         int res;
 131         int regexp_len, size, backref;
 132         int d_len = sizeof(temp) - 1;
 133         regex_t preg;
 134         regmatch_t pmatch[9];
 135
 136         tech_return[0] = '\0';
 137
 138         dst[0] = '\0';
 139
 140         if (len < sizeof(struct naptr)) {
 141                 ast_log(LOG_WARNING, "NAPTR record length too short\n");
 142                 return -1;
 143         }
 144         answer += sizeof(struct naptr);
 145         len -= sizeof(struct naptr);
 146         if ((res = parse_ie(flags, sizeof(flags) - 1, answer, len)) < 0) {
 147                 ast_log(LOG_WARNING, "Failed to get flags from NAPTR record\n");
 148                 return -1;
 149         } else {
 150                 answer += res;
 151                 len -= res;
 152         }
 153         if ((res = parse_ie(services, sizeof(services) - 1, answer, len)) < 0) {
 154                 ast_log(LOG_WARNING, "Failed to get services from NAPTR record\n");
 155                 return -1;
 156         } else {
 157                 answer += res;
 158                 len -= res;
 159         }
 160         if ((res = parse_ie(regexp, sizeof(regexp) - 1, answer, len)) < 0) {
 161                 ast_log(LOG_WARNING, "Failed to get regexp from NAPTR record\n");
 162                 return -1;
 163         } else {
 164                 answer += res;
 165                 len -= res;
 166         }
 167
 168         if ((res = dn_expand((unsigned char *)oanswer, (unsigned char *)answer + len, (unsigned char *)answer, repl, sizeof(repl) - 1)) < 0) {
 169                 ast_log(LOG_WARNING, "Failed to expand hostname\n");
 170                 return -1;
 171         }
 172
 173         if (option_debug > 2)   /* Advanced NAPTR debugging */
 174                 ast_log(LOG_DEBUG, "NAPTR input='%s', flags='%s', services='%s', regexp='%s', repl='%s'\n",
 175                         naptrinput, flags, services, regexp, repl);
 176
 177         if (tolower(flags[0]) != 'u') {
 178                 ast_log(LOG_WARNING, "NAPTR Flag must be 'U' or 'u'.\n");
 179                 return -1;
 180         }
 181
 182         p = strstr(services, "e2u+");
 183         if (p == NULL)
 184                 p = strstr(services, "E2U+");
 185         if (p){
 186                 p = p + 4;
 187                 if (strchr(p, ':')){
 188                         p = strchr(p, ':') + 1;
 189                 }
 190                 ast_copy_string(tech_return, p, sizeof(tech_return));
 191         } else {
 192
 193                 p = strstr(services, "+e2u");
 194                 if (p == NULL)
 195                         p = strstr(services, "+E2U");
 196                 if (p) {
 197                         *p = 0;
 198                         p = strchr(services, ':');
 199                         if (p)
 200                                 *p = 0;
 201                         ast_copy_string(tech_return, services, sizeof(tech_return));
 202                 }
 203         }
 204
 205         /* DEDBUGGING STUB
 206         ast_copy_string(regexp, "!^\\+43(.*)$!\\1@bla.fasel!", sizeof(regexp) - 1);
 207         */
 208
 209         regexp_len = strlen(regexp);
 210         if (regexp_len < 7) {
 211                 ast_log(LOG_WARNING, "Regex too short to be meaningful.\n");
 212                 return -1;
 213         }
 214
 215
 216         delim = regexp[0];
 217         delim2 = strchr(regexp + 1, delim);
 218         if ((delim2 == NULL) || (regexp[regexp_len-1] != delim)) {
 219                 ast_log(LOG_WARNING, "Regex delimiter error (on \"%s\").\n",regexp);
 220                 return -1;
 221         }
 222
 223         pattern = regexp + 1;
 224         *delim2 = 0;
 225         subst   = delim2 + 1;
 226         regexp[regexp_len-1] = 0;
 227
 228 #if 0
 229         printf("Pattern: %s\n", pattern);
 230         printf("Subst: %s\n", subst);
 231        printf("Input: %s\n", naptrinput);
 232 #endif
 233
 234 /*
 235  * now do the regex wizardry.
 236  */
 237
 238         if (regcomp(&preg, pattern, REG_EXTENDED | REG_NEWLINE)) {
 239                 ast_log(LOG_WARNING, "NAPTR Regex compilation error (regex = \"%s\").\n",regexp);
 240                 return -1;
 241         }
 242
 243         if (preg.re_nsub > 9) {
 244                 ast_log(LOG_WARNING, "NAPTR Regex compilation error: too many subs.\n");
 245                 regfree(&preg);
 246                 return -1;
 247         }
 248
 249         if (regexec(&preg, naptrinput, 9, pmatch, 0)) {
 250                 ast_log(LOG_WARNING, "NAPTR Regex match failed.\n");
 251                 regfree(&preg);
 252                 return -1;
 253         }
 254         regfree(&preg);
 255
 256         d = temp;
 257         d_len--;
 258         while (*subst && (d_len > 0)) {
 259                 if ((subst[0] == '\\') && isdigit(subst[1]) && (pmatch[subst[1]-'0'].rm_so != -1)) {
 260                         backref = subst[1]-'0';
 261                         size = pmatch[backref].rm_eo - pmatch[backref].rm_so;
 262                         if (size > d_len) {
 263                                 ast_log(LOG_WARNING, "Not enough space during NAPTR regex substitution.\n");
 264                                 return -1;
 265                                 }
 266                         memcpy(d, naptrinput + pmatch[backref].rm_so, size);
 267                         d += size;
 268                         d_len -= size;
 269                         subst += 2;
 270                 } else if (isprint(*subst)) {
 271                         *d++ = *subst++;
 272                         d_len--;
 273                 } else {
 274                         ast_log(LOG_WARNING, "Error during regex substitution.\n");
 275                         return -1;
 276                 }
 277         }
 278         *d = 0;
 279         ast_copy_string(dst, temp, dstsize);
 280         dst[dstsize - 1] = '\0';
 281
 282         if (*tech != '\0'){ /* check if it is requested NAPTR */
 283                 if (!strncasecmp(tech, "ALL", techsize)){
 284                         return 1; /* return or count any RR */
 285                 }
 286                 if (!strncasecmp(tech_return, tech, sizeof(tech_return)<techsize?sizeof(tech_return):techsize)){
 287                         ast_copy_string(tech, tech_return, techsize);
 288                         return 1; /* we got out RR */
 289                 } else { /* go to the next RR in the DNS answer */
 290                         return 0;
 291                 }
 292         }
 293
 294         /* tech was not specified, return first parsed RR */
 295         ast_copy_string(tech, tech_return, techsize);
 296
 297         return 1;
 298 }
 299
 300 /* do not return requested value, just count RRs and return thei number in dst */
 301 #define ENUMLOOKUP_OPTIONS_COUNT       1
 302
 303 struct enum_naptr_rr {
 304         struct naptr naptr; /* order and preference of RR */
 305         char *result; /* result of naptr parsing,e.g.: tel:+5553 */
 306         char *tech; /* Technology (from URL scheme) */
 307         int sort_pos; /* sort position */
 308 };
 309
 310 struct enum_context {
 311         char *dst;      /* Destination part of URL from ENUM */
 312         int dstlen;     /* Length */
 313         char *tech;     /* Technology (from URL scheme) */
 314         int techlen;    /* Length */
 315         char *txt;      /* TXT record in TXT lookup */
 316         int txtlen;     /* Length */
 317         char *naptrinput;       /* The number to lookup */
 318         int position; /* used as counter for RRs or specifies position of required RR */
 319         int options; /* options , see ENUMLOOKUP_OPTIONS_* defined above */
 320         struct enum_naptr_rr *naptr_rrs; /* array of parsed NAPTR RRs */
 321         int naptr_rrs_count; /* Size of array naptr_rrs */
 322 };
 323
 324 /*! \brief Callback for TXT record lookup */
 325 static int txt_callback(void *context, char *answer, int len, char *fullanswer)
 326 {
 327         struct enum_context *c = (struct enum_context *)context;
 328 #if 0
 329         printf("ENUMTXT Called\n");
 330 #endif
 331
 332         if (answer == NULL) {
 333                 c->txt = NULL;
 334                 c->txtlen = 0;
 335                 return 0;
 336         }
 337
 338         /* skip over first byte, as for some reason it's a vertical tab character */
 339         answer += 1;
 340         len -= 1;
 341
 342         /* answer is not null-terminated, but should be */
 343        /* this is safe to do, as answer has extra bytes on the end we can
 344            safely overwrite with a null */
 345         answer[len] = '\0';
 346         /* now increment len so that len includes the null, so that we can
 347            compare apples to apples */
 348         len +=1;
 349
 350         /* finally, copy the answer into c->txt */
 351         ast_copy_string(c->txt, answer, len < c->txtlen ? len : (c->txtlen));
 352
 353         /* just to be safe, let's make sure c->txt is null terminated */
 354         c->txt[(c->txtlen)-1] = '\0';
 355
 356         return 1;
 357 }
 358
 359 /*! \brief Callback from ENUM lookup function */
 360 static int enum_callback(void *context, char *answer, int len, char *fullanswer)
 361 {
 362        struct enum_context *c = context;
 363        void *p = NULL;
 364        int res;
 365
 366        res = parse_naptr(c->dst, c->dstlen, c->tech, c->techlen, answer, len, c->naptrinput);
 367
 368        if (res < 0) {
 369                 ast_log(LOG_WARNING, "Failed to parse naptr :(\n");
 370                 return -1;
 371        } else if (res > 0 && !ast_strlen_zero(c->dst)){ /* ok, we got needed NAPTR */
 372                if (c->options & ENUMLOOKUP_OPTIONS_COUNT){ /* counting RRs */
 373                        c->position++;
 374                        snprintf(c->dst, c->dstlen, "%d", c->position);
 375                } else  {
 376                        if ((p = ast_realloc(c->naptr_rrs, sizeof(*c->naptr_rrs) * (c->naptr_rrs_count + 1)))) {
 377                                c->naptr_rrs = p;
 378                                memcpy(&c->naptr_rrs[c->naptr_rrs_count].naptr, answer, sizeof(c->naptr_rrs->naptr));
 379                                /* printf("order=%d, pref=%d\n", ntohs(c->naptr_rrs[c->naptr_rrs_count].naptr.order), ntohs(c->naptr_rrs[c->naptr_rrs_count].naptr.pref)); */
 380                                c->naptr_rrs[c->naptr_rrs_count].result = strdup(c->dst);
 381                                c->naptr_rrs[c->naptr_rrs_count].tech = strdup(c->tech);
 382                                c->naptr_rrs[c->naptr_rrs_count].sort_pos = c->naptr_rrs_count;
 383                                c->naptr_rrs_count++;
 384                        }
 385                        c->dst[0] = 0;
 386                }
 387                return 0;
 388         }
 389
 390        if (c->options & ENUMLOOKUP_OPTIONS_COUNT)       { /* counting RRs */
 391                snprintf(c->dst, c->dstlen, "%d", c->position);
 392        }
 393
 394         return 0;
 395 }
 396
 397 /*! \brief ENUM lookup */
 398 int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int dstlen, char *tech, int techlen, char* suffix, char* options)
 399 {
 400         struct enum_context context;
 401         char tmp[259 + 512];
 402         char naptrinput[512];
 403         int pos = strlen(number) - 1;
 404         int newpos = 0;
 405         int ret = -1;
 406         struct enum_search *s = NULL;
 407         int version = -1;
 408         /* for ISN rewrite */
 409         char *p1 = NULL;
 410         char *p2 = NULL;
 411         int k = 0;
 412         int i = 0;
 413         int z = 0;
 414
 415         ast_copy_string(naptrinput, number[0] == 'n' ? number+1 : number, sizeof(naptrinput));
 416
 417         context.naptrinput = naptrinput;        /* The number */
 418         context.dst = dst;                      /* Return string */
 419         context.dstlen = dstlen;
 420         context.tech = tech;
 421         context.techlen = techlen;
 422         context.options = 0;
 423         context.position = 1;
 424         context.naptr_rrs = NULL;
 425         context.naptr_rrs_count = 0;
 426
 427         if (options != NULL) {
 428                 if (*options == 'c') {
 429                         context.options = ENUMLOOKUP_OPTIONS_COUNT;
 430                         context.position = 0;
 431                 } else {
 432                         context.position = atoi(options);
 433                         if (context.position < 1)
 434                                 context.position = 1;
 435                 }
 436         }
 437
 438         if (pos > 128)
 439                 pos = 128;
 440
 441         /* ISN rewrite */
 442         p1 = strchr(number, '*');
 443
 444         if (number[0] == 'n') { /* do not perform ISN rewrite ('n' is testing flag) */
 445                 p1 = NULL;
 446                 k = 1; /* strip 'n' from number */
 447         }
 448
 449         if (p1 != NULL) {
 450                 p2 = p1+1;
 451                 while (p1 > number){
 452                         p1--;
 453                         tmp[newpos++] = *p1;
 454                         tmp[newpos++] = '.';
 455                 }
 456                 if (*p2) {
 457                         while(*p2 && newpos < 128){
 458                                 tmp[newpos++] = *p2;
 459                                 p2++;
 460                         }
 461                         tmp[newpos++] = '.';
 462                 }
 463
 464         } else {
 465                 while (pos >= k) {
 466                         if (isdigit(number[pos])) {
 467                                 tmp[newpos++] = number[pos];
 468                                 tmp[newpos++] = '.';
 469                         }
 470                         pos--;
 471                 }
 472         }
 473
 474         if (chan && ast_autoservice_start(chan) < 0)
 475                 return -1;
 476
 477         for (;;) {
 478                 ast_mutex_lock(&enumlock);
 479                 if (version != enumver) {
 480                         /* Ooh, a reload... */
 481                         s = toplevs;
 482                         version = enumver;
 483                 } else {
 484                         s = s->next;
 485                 }
 486                 ast_copy_string(tmp + newpos, suffix ? suffix : s->toplev, sizeof(tmp) - newpos);
 487                 ast_mutex_unlock(&enumlock);
 488                 if (!s)
 489                         break;
 490                 ret = ast_search_dns(&context, tmp, C_IN, T_NAPTR, enum_callback);
 491                 if (ret > 0)
 492                         break;
 493                 if (suffix != NULL)
 494                        break;
 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 }