enum.c

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/*
 * $Id: enum.c 4518 2008-07-28 15:39:28Z henningw $
 *
 * Enum and E164 related functions
 *
 * Copyright (C) 2002-2008 Juha Heinanen
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <stdlib.h>

#include "enum.h"
#include "../../parser/parse_uri.h"
#include "../../parser/parse_from.h"
#include "../../ut.h"
#include "../../resolve.h"
#include "../../mem/mem.h"
#include "../../dset.h"
#include "../../qvalue.h"
#include "enum_mod.h"
#include "../../regexp.h"
#include "../../pvar.h"

/*
 * Input: E.164 number w/o leading +
 *
 * Output: number of digits in the country code
 *       0 on invalid number
 *
 * convention:
 *   3 digits is the default length of a country code.
 *   country codes 1 and 7 are a single digit.
 *   the following country codes are two digits: 20, 27, 30-34, 36, 39,
 *     40, 41, 43-49, 51-58, 60-66, 81, 82, 84, 86, 90-95, 98.
 */
static int cclen(const char *number)
{
   char d1,d2;

   if (!number || (strlen(number) < 3))
      return(0);

   d1 = number[0];
   d2 = number[1];
   
   if (!isdigit((int)d2)) 
      return(0);

   switch(d1) {
      case '1':
      case '7':
         return(1);
      case '2':
         if ((d2 == '0') || (d1 == '7'))
            return(2);
         break;
      case '3':
         if ((d2 >= '0') && (d1 <= '4'))
            return(2);
         if ((d2 == '6') || (d1 == '9'))
            return(2);
         break;
      case '4':
         if (d2 != '2')
            return(2);
         break;
      case '5':
         if ((d2 >= '1') && (d1 <= '8'))
            return(2);
         break;
      case '6':
         if (d1 <= '6')
            return(2);
         break;
      case '8':
         if ((d2 == '1') || (d1 == '2') || (d1 == '4') || (d1 == '6')) 
            return(2);
         break;
      case '9':
         if (d1 <= '5')
            return(2);
         if (d2 == '8')
            return(2);
         break;
      default:
         return(0);
   }

   return(3);
}



/* return the length of the string until c, if not found returns n */
static inline int findchr(char* p, int c, unsigned int size)
{
   int len=0;

   for(;len<size;p++){
      if (*p==(unsigned char)c) {
         return len;
      }
      len++;   
   }
   return len;
}


/* Parse NAPTR regexp field of the form !pattern!replacement! and return its
 * components in pattern and replacement parameters.  Regexp field starts at
 * address first and is len characters long.
 */
static inline int parse_naptr_regexp(char* first, int len, str* pattern,
                              str* replacement)
{
   char *second, *third;

   if (len > 0) {
      if (*first == '!') {
         second = (char *)memchr((void *)(first + 1), '!', len - 1);
         if (second) {
            len = len - (second - first + 1);
            if (len > 0) {
               third = memchr(second + 1, '!', len);
               if (third) {
                  pattern->len = second - first - 1;
                  pattern->s = first + 1;
                  replacement->len = third - second - 1;
                  replacement->s = second + 1;
                  return 1;
               } else {
                  LM_ERR("Third ! missing from regexp\n");
                  return -1;
               }
            } else {
               LM_ERR("Third ! missing from regexp\n");
               return -2;
            }
         } else {
            LM_ERR("Second ! missing from regexp\n");
            return -3;
         }
      } else {
         LM_ERR("First ! missing from regexp\n");
         return -4;
      }
   } else {
      LM_ERR("Regexp missing\n");
      return -5;
   }
}
/* Checks if NAPTR record has flag u and its services field
 * e2u+[service:]sip or
 * e2u+service[+service[+service[+...]]]
 */
static inline int sip_match( struct naptr_rdata* naptr, str* service)
{
  if (service->len == 0) {
    return (naptr->flags_len == 1) &&
      ((naptr->flags[0] == 'u') || (naptr->flags[0] == 'U')) &&
      (naptr->services_len == 7) &&
      ((strncasecmp(naptr->services, "e2u+sip", 7) == 0) ||
       (strncasecmp(naptr->services, "sip+e2u", 7) == 0));
  } else if (service->s[0] != '+') {
    return (naptr->flags_len == 1) &&
      ((naptr->flags[0] == 'u') || (naptr->flags[0] == 'U')) &&
      (naptr->services_len == service->len + 8) &&
      (strncasecmp(naptr->services, "e2u+", 4) == 0) &&
      (strncasecmp(naptr->services + 4, service->s, service->len) == 0) &&
      (strncasecmp(naptr->services + 4 + service->len, ":sip", 4) == 0);
  } else { /* handle compound NAPTRs and multiple services */
    str bakservice, baknaptr; /* we bakup the str */
    int naptrlen, len;        /* length of the extracted service */

    /* RFC 3761, NAPTR service field must start with E2U+ */
    if (strncasecmp(naptr->services, "e2u+", 4) != 0) {
      return 0;
    }
    baknaptr.s   = naptr->services + 4; /* leading 'e2u+' */
    baknaptr.len = naptr->services_len - 4;
    for (;;) { /* iterate over services in NAPTR */
      bakservice.s   = service->s + 1; /* leading '+' */
      bakservice.len = service->len - 1;
      naptrlen = findchr(baknaptr.s,'+',baknaptr.len);

      for (;;) { /* iterate over services in enum_query */
        len = findchr(bakservice.s,'+',bakservice.len);
        if ((naptrlen == len ) && !strncasecmp(baknaptr.s, bakservice.s, len)){
          return 1;
        }
        if ( (bakservice.len -= len+1) > 0) {
          bakservice.s += len+1;
          continue;
        }
        break;
      }
      if ( (baknaptr.len -= naptrlen+1) > 0) {
        baknaptr.s += naptrlen+1;
        continue;
      }
      break;
    }
    /* no matching service found */
    return 0;
  }
}


/*
 * Checks if argument is an e164 number starting with +
 */
static inline int is_e164(str* _user)
{
   int i;
   char c;
   
   if ((_user->len > 2) && (_user->len < 17) && ((_user->s)[0] == '+')) {
      for (i = 1; i < _user->len; i++) {
         c = (_user->s)[i];
         if ((c < '0') || (c > '9')) return -1;
      }
      return 1;
   } else {
       return -1;
   }
}
            

/*
 * Call is_from_user_enum_2 with module parameter suffix and default service.
 */
int is_from_user_enum_0(struct sip_msg* _msg, char* _str1, char* _str2)
{
   return is_from_user_enum_2(_msg, (char *)(&suffix), (char *)(&service));
}

/*
 * Call is_from_user_enum_2 with given suffix and default service.
 */
int is_from_user_enum_1(struct sip_msg* _msg, char* _suffix, char* _str2)
{
   return is_from_user_enum_2(_msg, _suffix, (char *)(&service));
}

/*
 * Check if from user is a valid enum based user, and check to make sure
 * that the src_ip == an srv record that maps to the enum from user.
 */
int is_from_user_enum_2(struct sip_msg* _msg, char* _suffix, char* _service)
{
   struct ip_addr addr;
   struct hostent* he;
   unsigned short zp;
   unsigned short proto;
   char *user_s;
   int user_len, i, j;
   char name[MAX_DOMAIN_SIZE];
   char uri[MAX_URI_SIZE];
   struct sip_uri *furi;
   struct sip_uri luri;
   struct rdata* head;

   str* suffix;
   str* service;

   struct rdata* l;
   struct naptr_rdata* naptr;

   str pattern, replacement, result;
   char string[17];

   if (parse_from_header(_msg) < 0) {
       LM_ERR("Failed to parse From header\n");
       return -1;
   }
   
   if(_msg->from==NULL || get_from(_msg)==NULL) {
       LM_DBG("No From header\n");
       return -1;
   }

   if ((furi = parse_from_uri(_msg)) == NULL) {
       LM_ERR("Failed to parse From URI\n");
       return -1;
   }

   suffix = (str*)_suffix;
   service = (str*)_service;

   if (is_e164(&(furi->user)) == -1) {
       LM_ERR("From URI user is not an E164 number\n");
       return -1;
   }

   /* assert: the from user is a valid formatted e164 string */

   user_s = furi->user.s;
   user_len = furi->user.len;

   j = 0;
   for (i = user_len - 1; i > 0; i--) {
      name[j] = user_s[i];
      name[j + 1] = '.';
      j = j + 2;
   }

   memcpy(name + j, suffix->s, suffix->len + 1);

   head = get_record(name, T_NAPTR);

   if (head == 0) {
      LM_DBG("No NAPTR record found for %s.\n", name);
      return -3;
   }

   /* we have the naptr records, loop and find an srv record with */
   /* same ip address as source ip address, if we do then true is returned */

   for (l = head; l; l = l->next) {

      if (l->type != T_NAPTR) continue; /*should never happen*/
      naptr = (struct naptr_rdata*)l->rdata;
      if (naptr == 0) {
         LM_ERR("Null rdata in DNS response\n");
         free_rdata_list(head);
         return -4;
      }

      LM_DBG("ENUM query on %s: order %u, pref %u, flen %u, flags "
             "'%.*s', slen %u, services '%.*s', rlen %u, "
             "regexp '%.*s'\n",
             name, naptr->order, naptr->pref,
          naptr->flags_len, (int)(naptr->flags_len), ZSW(naptr->flags), naptr->services_len,
          (int)(naptr->services_len), ZSW(naptr->services), naptr->regexp_len,
          (int)(naptr->regexp_len), ZSW(naptr->regexp));

      if (sip_match(naptr, service) != 0) {
         if (parse_naptr_regexp(&(naptr->regexp[0]), naptr->regexp_len,
                &pattern, &replacement) < 0) {
            free_rdata_list(head); /*clean up*/
            LM_ERR("Parsing of NAPTR regexp failed\n");
            return -5;
         }
#ifdef LATER
         if ((pattern.len == 4) && (strncmp(pattern.s, "^.*$", 4) == 0)) {
            LM_DBG("Resulted in replacement: '%.*s'\n",
                   replacement.len, ZSW(replacement.s));          
            retval = set_uri(_msg, replacement.s, replacement.len);
            free_rdata_list(head); /*clean up*/
            return retval;
         }
#endif
         result.s = &(uri[0]);
         result.len = MAX_URI_SIZE;
         /* Avoid making copies of pattern and replacement */
         pattern.s[pattern.len] = (char)0;
         replacement.s[replacement.len] = (char)0;
         /* We have already checked the size of
            _msg->parsed_uri.user.s */ 
         memcpy(&(string[0]), user_s, user_len);
         string[user_len] = (char)0;
         if (reg_replace(pattern.s, replacement.s, &(string[0]),
               &result) < 0) {
            pattern.s[pattern.len] = '!';
            replacement.s[replacement.len] = '!';
            LM_ERR("Regexp replace failed\n");
            free_rdata_list(head); /*clean up*/
            return -6;
         }
         LM_DBG("Resulted in replacement: '%.*s'\n",
             result.len, ZSW(result.s));

         if(parse_uri(result.s, result.len, &luri) < 0)
         {
            LM_ERR("Parsing of URI <%.*s> failed\n",
                   result.len, result.s);
            free_rdata_list(head); /*clean up*/
            return -7;
         }

         pattern.s[pattern.len] = '!';
         replacement.s[replacement.len] = '!';

         zp = 0;
         proto = PROTO_NONE;
         he = sip_resolvehost(&luri.host, &zp, &proto,
            (luri.type==SIPS_URI_T)?1:0 , 0);

         hostent2ip_addr(&addr, he, 0);

         if(ip_addr_cmp(&addr, &_msg->rcv.src_ip))
         {
            free_rdata_list(head);
            return(1);
         }
      }
   }
   free_rdata_list(head); /*clean up*/
   LM_DBG("FAIL\n");

    /* must not have found the record */
    return(-8);
}



/* 
 * Add parameter to URI.
 */
int add_uri_param(str *uri, str *param, str *new_uri)
{
   struct sip_uri puri;
   char *at;

   if (parse_uri(uri->s, uri->len, &puri) < 0) {
      return 0;
   }

   /* if current uri has no headers, pad param to the end of uri */
   if (puri.headers.len == 0) {
      memcpy(uri->s + uri->len, param->s, param->len);
      uri->len = uri->len + param->len;
      new_uri->len = 0;
      return 1;
   }

   /* otherwise take the long path and create new_uri */
   at = new_uri->s;
   switch (puri.type) {
   case SIP_URI_T:
       memcpy(at, "sip:", 4);
       at = at + 4;
       break;
   case SIPS_URI_T:
       memcpy(at, "sips:", 5);
       at = at + 5;
       break;
   case TEL_URI_T:
       memcpy(at, "tel:", 4);
       at = at + 4;
       break;
   case TELS_URI_T:
       memcpy(at, "tels:", 5);
       at = at + 5;
       break;
   default:
       LM_ERR("Unknown URI scheme <%d>\n", puri.type);
       return 0;
   }
   if (puri.user.len) {
      memcpy(at, puri.user.s, puri.user.len);
      at = at + puri.user.len;
      if (puri.passwd.len) {
         *at = ':';
         at = at + 1;
         memcpy(at, puri.passwd.s, puri.passwd.len);
         at = at + puri.passwd.len;
      };
      *at = '@';
      at = at + 1;
   }
   memcpy(at, puri.host.s, puri.host.len);
   at = at + puri.host.len;
   if (puri.port.len) {
      *at = ':';
      at = at + 1;
      memcpy(at, puri.port.s, puri.port.len);
      at = at + puri.port.len;
   }
   if (puri.params.len) {
      *at = ';';
      at = at + 1;
      memcpy(at, puri.params.s, puri.params.len);
      at = at + puri.params.len;
   }
   memcpy(at, param->s, param->len);
   at = at + param->len;
   *at = '?';
   at = at + 1;
   memcpy(at, puri.headers.s, puri.headers.len);
   at = at + puri.headers.len;
   new_uri->len = at - new_uri->s;
   return 1;
}

/*
 * Tests if one result record is "greater" that the other.  Non-NAPTR records
 * greater that NAPTR record.  An invalid NAPTR record is greater than a 
 * valid one.  Valid NAPTR records are compared based on their
 * (order,preference).
 */
static inline int naptr_greater(struct rdata* a, struct rdata* b)
{
   struct naptr_rdata *na, *nb;

   if (a->type != T_NAPTR) return 1;
   if (b->type != T_NAPTR) return 0;

   na = (struct naptr_rdata*)a->rdata;
   if (na == 0) return 1;

   nb = (struct naptr_rdata*)b->rdata;
   if (nb == 0) return 0;
   
   return (((na->order) << 16) + na->pref) >
      (((nb->order) << 16) + nb->pref);
}
   
   
/*
 * Bubble sorts result record list according to naptr (order,preference).
 */
static inline void naptr_sort(struct rdata** head)
{
   struct rdata *p, *q, *r, *s, *temp, *start;

        /* r precedes p and s points to the node up to which comparisons
         are to be made */ 

   s = NULL;
   start = *head;
   while ( s != start -> next ) { 
      r = p = start ; 
      q = p -> next ;
      while ( p != s ) { 
         if ( naptr_greater(p, q) ) { 
            if ( p == start ) { 
               temp = q -> next ; 
               q -> next = p ; 
               p -> next = temp ;
               start = q ; 
               r = q ; 
            } else {
               temp = q -> next ; 
               q -> next = p ; 
               p -> next = temp ;
               r -> next = q ; 
               r = q ; 
            } 
         } else {
            r = p ; 
            p = p -> next ; 
         } 
         q = p -> next ; 
         if ( q == s ) s = p ; 
      }
   }
   *head = start;
}  
   

/*
 * Makes enum query on name.  On success, rewrites user part and 
 * replaces Request-URI.
 */
int do_query(struct sip_msg* _msg, char *user, char *name, str *service) {

    char uri[MAX_URI_SIZE];
    char new_uri[MAX_URI_SIZE];
    unsigned int priority, curr_prio, first;
    qvalue_t q;
    struct rdata* head;
    struct rdata* l;
    struct naptr_rdata* naptr;
    str pattern, replacement, result, new_result;

    head = get_record(name, T_NAPTR);
    
    if (head == 0) {
   LM_DBG("No NAPTR record found for %s.\n", name);
   return -1;
    }
    
    naptr_sort(&head);

    q = MAX_Q - 10;
    curr_prio = 0;
    first = 1;

    for (l = head; l; l = l->next) {

   if (l->type != T_NAPTR) continue; /*should never happen*/
   naptr = (struct naptr_rdata*)l->rdata;
   if (naptr == 0) {
       LM_ERR("Null rdata in DNS response\n");
       continue;
   }

   LM_DBG("ENUM query on %s: order %u, pref %u, flen %u, flags '%.*s', "
          "slen %u, services '%.*s', rlen %u, regexp '%.*s'\n",
          name, naptr->order, naptr->pref,
       naptr->flags_len, (int)(naptr->flags_len), ZSW(naptr->flags),
       naptr->services_len,
       (int)(naptr->services_len), ZSW(naptr->services), naptr->regexp_len,
       (int)(naptr->regexp_len), ZSW(naptr->regexp));
   
   if (sip_match(naptr, service) == 0) continue;
   
   if (parse_naptr_regexp(&(naptr->regexp[0]), naptr->regexp_len,
                &pattern, &replacement) < 0) {
       LM_ERR("Parsing of NAPTR regexp failed\n");
       continue;
   }
   result.s = &(uri[0]);
   result.len = MAX_URI_SIZE;
   /* Avoid making copies of pattern and replacement */
   pattern.s[pattern.len] = (char)0;
   replacement.s[replacement.len] = (char)0;
   if (reg_replace(pattern.s, replacement.s, user, &result) < 0) {
       pattern.s[pattern.len] = '!';
       replacement.s[replacement.len] = '!';
       LM_ERR("Regexp replace failed\n");
       continue;
   }
   LM_DBG("Resulted in replacement: '%.*s'\n", result.len, ZSW(result.s));
   pattern.s[pattern.len] = '!';
   replacement.s[replacement.len] = '!';
   
   if (param.len > 0) {
       if (result.len + param.len > MAX_URI_SIZE - 1) {
      LM_ERR("URI is too long\n");
      continue;
       }
       new_result.s = &(new_uri[0]);
       new_result.len = MAX_URI_SIZE;
       if (add_uri_param(&result, &param, &new_result) == 0) {
      LM_ERR("Parsing of URI <%.*s> failed\n",
             result.len, result.s);
      continue;
       }
       if (new_result.len > 0) {
      result = new_result;
       }
   }
   
   if (first) {
       if (rewrite_uri(_msg, &result) == -1) {
      goto done;
       }
       set_ruri_q(q);
       first = 0;
       curr_prio = ((naptr->order) << 16) + naptr->pref;
   } else {
       priority = ((naptr->order) << 16) + naptr->pref;
       if (priority > curr_prio) {
      q = q - 10;
      curr_prio = priority;
       }
       if (append_branch(_msg, &result, 0, 0, q, 0, 0) == -1) {
      goto done;
       }
   }
    }

done:
    free_rdata_list(head);
    return first ? -1 : 1;
}

   
/*
 * Call enum_query_2 with module parameter suffix and default service.
 */
int enum_query_0(struct sip_msg* _msg, char* _str1, char* _str2)
{
   return enum_query_2(_msg, (char *)(&suffix), (char *)(&service));
}


/*
 * Call enum_query_2 with given suffix and default service.
 */
int enum_query_1(struct sip_msg* _msg, char* _suffix, char* _str2)
{
   return enum_query_2(_msg, _suffix, (char *)(&service));
}


/*
 * See documentation in README file.
 */
int enum_query_2(struct sip_msg* _msg, char* _suffix, char* _service)
{
   char *user_s;
   int user_len, i, j;
   char name[MAX_DOMAIN_SIZE];
   char string[17];

   str *suffix, *service;

   suffix = (str*)_suffix;
   service = (str*)_service;

   if (parse_sip_msg_uri(_msg) < 0) {
      LM_ERR("Parsing of R-URI failed\n");
      return -1;
   }

   if (is_e164(&(_msg->parsed_uri.user)) == -1) {
      LM_ERR("R-URI user is not an E164 number\n");
      return -1;
   }

   user_s = _msg->parsed_uri.user.s;
   user_len = _msg->parsed_uri.user.len;

   memcpy(&(string[0]), user_s, user_len);
   string[user_len] = (char)0;

   j = 0;
   for (i = user_len - 1; i > 0; i--) {
      name[j] = user_s[i];
      name[j + 1] = '.';
      j = j + 2;
   }

   memcpy(name + j, suffix->s, suffix->len + 1);

   return do_query(_msg, string, name, service);
}


/*********** INFRASTRUCTURE ENUM ***************/

/*
 * Call enum_query_2 with default suffix and service.
 */
int i_enum_query_0(struct sip_msg* _msg, char* _suffix, char* _service)
{
   return i_enum_query_2(_msg, (char *)(&i_suffix), (char *)(&service));
}

/*
 * Call enum_query_2 with given suffix and default service.
 */
int i_enum_query_1(struct sip_msg* _msg, char* _suffix, char* _service)
{
   return i_enum_query_2(_msg, _suffix, (char *)(&service));
}


int i_enum_query_2(struct sip_msg* _msg, char* _suffix, char* _service)
{
   char *user_s;
   int user_len, i, j;
   char name[MAX_DOMAIN_SIZE];
   char apex[MAX_COMPONENT_SIZE + 1];
   char separator[MAX_COMPONENT_SIZE + 1];
   int sdl = 0;    /* subdomain location: infrastructure enum offset */
   int cc_len;
   struct rdata* head;

   char string[17];

   str *suffix, *service;

   suffix = (str*)_suffix;
   service = (str*)_service;

   if (parse_sip_msg_uri(_msg) < 0) {
      LM_ERR("Parsing of R-URI failed\n");
      return -1;
   }

   if (is_e164(&(_msg->parsed_uri.user)) == -1) {
      LM_ERR("R-URI user is not an E164 number\n");
      return -1;
   }

   user_s = _msg->parsed_uri.user.s;
   user_len = _msg->parsed_uri.user.len;

   /* make sure we don't run out of space in strings */
   if (( 2*user_len + MAX_COMPONENT_SIZE + MAX_COMPONENT_SIZE + 4) > MAX_DOMAIN_SIZE) {
      LM_ERR("Strings too long\n");
      return -1;
   }
   if ( i_branchlabel.len > MAX_COMPONENT_SIZE ) {
      LM_ERR("i_branchlabel too long\n");
      return -1;
   }
   if ( suffix->len > MAX_COMPONENT_SIZE ) {
      LM_ERR("Suffix too long\n");
      return -1;
   }


   memcpy(&(string[0]), user_s, user_len);
   string[user_len] = (char)0;

   /* Set up parameters as for user-enum */
   memcpy(apex,  suffix->s , suffix->len);
   apex[suffix->len] = (char)0;
   sdl = 0;    /* where to insert i-enum separator */
   separator[0] = 0; /* don't insert anything */

   cc_len = cclen(string + 1);

   if (!strncasecmp(i_bl_alg.s,"ebl",i_bl_alg.len)) {
      sdl = cc_len; /* default */

      j = 0;
      memcpy(name, i_branchlabel.s, i_branchlabel.len);
      j += i_branchlabel.len;
      name[j++] = '.';

      for (i = cc_len ; i > 0; i--) {
         name[j++] = user_s[i];
         name[j++] = '.';
      }
      memcpy(name + j, suffix->s, suffix->len + 1);

      LM_DBG("Looking for EBL record for %s.\n", name); 
      head = get_record(name, T_EBL);
      if (head == 0) {
         LM_DBG("No EBL found for %s. Defaulting to user ENUM.\n",name);
      } else {
            struct ebl_rdata* ebl;
         ebl = (struct ebl_rdata *) head->rdata;

         LM_DBG("EBL record for %s is %d / %.*s / %.*s.\n",
                name, ebl->position, (int)ebl->separator_len,
                ebl->separator,(int)ebl->apex_len, ebl->apex);

         if ((ebl->apex_len > MAX_COMPONENT_SIZE) || (ebl->separator_len > MAX_COMPONENT_SIZE)) {
            LM_ERR("EBL strings too long\n"); 
            return -1;
         }

         if (ebl->position > 15)  {
            LM_ERR("EBL position too large (%d)\n",
                   ebl->position); 
            return -1;
         }

         sdl = ebl->position;

         memcpy(separator, ebl->separator, ebl->separator_len);
         separator[ebl->separator_len] = 0;

         memcpy(apex, ebl->apex, ebl->apex_len);
         apex[ebl->apex_len] = 0;
         free_rdata_list(head);
      }
   } else if (!strncasecmp(i_bl_alg.s,"txt",i_bl_alg.len)) {
      sdl = cc_len; /* default */
      memcpy(separator, i_branchlabel.s, i_branchlabel.len);
      separator[i_branchlabel.len] = 0;
      /* no change to apex */

      j = 0;
      memcpy(name, i_branchlabel.s, i_branchlabel.len);
      j += i_branchlabel.len;
      name[j++] = '.';

      for (i = cc_len ; i > 0; i--) {
         name[j++] = user_s[i];
         name[j++] = '.';
      }
      memcpy(name + j, suffix->s, suffix->len + 1);

      head = get_record(name, T_TXT);
      if (head == 0) {
         LM_DBG("TXT found for %s. Defaulting to %d\n",
                name, cc_len);
      } else {
         sdl = atoi(((struct txt_rdata*)head->rdata)->txt);
         LM_DBG("TXT record for %s is %d.\n", name, sdl);

         if ((sdl < 0) || (sdl > 10)) {
            LM_ERR("Sdl %d out of bounds. Set back to cc_len.\n", sdl);
            sdl = cc_len;
         }
         free_rdata_list(head);
      }
   } else { /* defaults to CC */
      sdl = cc_len;
      memcpy(separator, i_branchlabel.s, i_branchlabel.len);
      separator[i_branchlabel.len] = 0;
      /* no change to apex */
   }

   j = 0;
   sdl++; /* to avoid comparing i to (sdl+1) */
   for (i = user_len - 1; i > 0; i--) {
      name[j] = user_s[i];
      name[j + 1] = '.';
      j = j + 2;
      if (separator[0] && (i == sdl)) { /* insert the I-ENUM separator here? */
         strcpy(name + j, separator);  /* we've checked string sizes. */
         j += strlen(separator);
         name[j++] = '.';
      }
   }

   memcpy(name + j, apex, strlen(apex)+1);

   return do_query(_msg, string, name, service);
}



/******************* FQUERY *******************/


/*
 * Call enum_pv_query_3 with pv arg, module parameter suffix,
 * and default service.
 */
int enum_pv_query_1(struct sip_msg* _msg, char* _sp)
{
    return enum_pv_query_3(_msg, _sp, (char *)(&suffix), (char *)(&service));
}

/*
 * Call enum_pv_query_3 with pv and suffix args and default service.
 */
int enum_pv_query_2(struct sip_msg* _msg, char* _sp, char* _suffix)
{
    return enum_pv_query_3(_msg, _sp, _suffix, (char *)(&service));
}

/*
 * See documentation in README file.
 */

int enum_pv_query_3(struct sip_msg* _msg, char* _sp, char* _suffix,
          char* _service)
{
   char *user_s;
   int user_len, i, j, first;
   char name[MAX_DOMAIN_SIZE];
   char uri[MAX_URI_SIZE];
   char new_uri[MAX_URI_SIZE];
   unsigned int priority, curr_prio;
   qvalue_t q;
   char tostring[17];
   struct rdata* head;
   struct rdata* l;
   struct naptr_rdata* naptr;
   str pattern, replacement, result, new_result;
   str *suffix, *service;
   char string[17];
   pv_spec_t *sp;
   pv_value_t pv_val;

   sp = (pv_spec_t *)_sp;
   suffix = (str*)_suffix;
   service = (str*)_service;

   /*
    *  Get R-URI user to tostring
    */
   if (parse_sip_msg_uri(_msg) < 0) {
      LM_ERR("R-URI parsing failed\n");
      return -1;
   }

   if (is_e164(&(_msg->parsed_uri.user)) == -1) {
      LM_ERR("R-URI user is not an E164 number\n");
      return -1;
   }

   user_s = _msg->parsed_uri.user.s;
   user_len = _msg->parsed_uri.user.len;

   memcpy(&(tostring[0]), user_s, user_len);
   tostring[user_len] = (char)0;

   /*
    * Get E.164 number from pseudo variable
         */
   if (sp && (pv_get_spec_value(_msg, sp, &pv_val) == 0)) {
       if (pv_val.flags & PV_VAL_STR) {
      if (pv_val.rs.len == 0 || pv_val.rs.s == NULL) {
          LM_DBG("Missing E.164 number\n");
          return -1;
      }
       } else {
      LM_DBG("Pseudo variable value is not string\n");
      return -1;
   }
   } else {
       LM_DBG("Cannot get pseudo variable value\n");
       return -1;
   }
   if (is_e164(&(pv_val.rs)) == -1) {
       LM_ERR("pseudo variable does not contain an E164 number\n");
       return -1;
   }

   user_s = pv_val.rs.s;
   user_len = pv_val.rs.len;

   memcpy(&(string[0]), user_s, user_len);
   string[user_len] = (char)0;

   j = 0;
   for (i = user_len - 1; i > 0; i--) {
      name[j] = user_s[i];
      name[j + 1] = '.';
      j = j + 2;
   }

   memcpy(name + j, suffix->s, suffix->len + 1);

   head = get_record(name, T_NAPTR);

   if (head == 0) {
      LM_DBG("No NAPTR record found for %s.\n", name);
      return -1;
   }

   naptr_sort(&head);

   q = MAX_Q - 10;
   curr_prio = 0;
   first = 1;

   for (l = head; l; l = l->next) {

      if (l->type != T_NAPTR) continue; /*should never happen*/
      naptr = (struct naptr_rdata*)l->rdata;
      if (naptr == 0) {
         LM_ERR("Null rdata in DNS response\n");
         continue;
      }

      LM_DBG("ENUM query on %s: order %u, pref %u, flen %u, flags "
             "'%.*s', slen %u, services '%.*s', rlen %u, "
             "regexp '%.*s'\n",
             name, naptr->order, naptr->pref,
          naptr->flags_len, (int)(naptr->flags_len), ZSW(naptr->flags),
          naptr->services_len,
          (int)(naptr->services_len), ZSW(naptr->services), naptr->regexp_len,
          (int)(naptr->regexp_len), ZSW(naptr->regexp));

      if (sip_match(naptr, service) == 0) continue;

      if (parse_naptr_regexp(&(naptr->regexp[0]), naptr->regexp_len,
                   &pattern, &replacement) < 0) {
         LM_ERR("Parsing of NAPTR regexp failed\n");
         continue;
      }
      result.s = &(uri[0]);
      result.len = MAX_URI_SIZE;
      /* Avoid making copies of pattern and replacement */
      pattern.s[pattern.len] = (char)0;
      replacement.s[replacement.len] = (char)0;
      if (reg_replace(pattern.s, replacement.s, &(tostring[0]),
            &result) < 0) {
         pattern.s[pattern.len] = '!';
         replacement.s[replacement.len] = '!';
         LM_ERR("Regexp replace failed\n");
         continue;
      }
      LM_DBG("Resulted in replacement: '%.*s'\n",
             result.len, ZSW(result.s));
      pattern.s[pattern.len] = '!';
      replacement.s[replacement.len] = '!';
      
      if (param.len > 0) {
         if (result.len + param.len > MAX_URI_SIZE - 1) {
            LM_ERR("URI is too long\n");
            continue;
         }
         new_result.s = &(new_uri[0]);
         new_result.len = MAX_URI_SIZE;
         if (add_uri_param(&result, &param, &new_result) == 0) {
            LM_ERR("Parsing of URI <%.*s> failed\n",
                   result.len, result.s);
            continue;
         }
         if (new_result.len > 0) {
            result = new_result;
         }
      }

      if (first) {
         if (rewrite_uri(_msg, &result) == -1) {
            goto done;
         }
         set_ruri_q(q);
         first = 0;
         curr_prio = ((naptr->order) << 16) + naptr->pref;
      } else {
         priority = ((naptr->order) << 16) + naptr->pref;
         if (priority > curr_prio) {
            q = q - 10;
            curr_prio = priority;
         }
         if (append_branch(_msg, &result, 0, 0, q, 0, 0) == -1) {
            goto done;
         }
      }
   }

done:
   free_rdata_list(head);
   return first ? -1 : 1;
}