res_config_ldap.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005, Oxymium sarl
 * Manuel Guesdon <[email protected]> - LDAP RealTime Driver Author/Adaptor
 *
 * Copyright (C) 2007, Digium, Inc.
 * Russell Bryant <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 *
 */

/*! \file
 *
 * \brief LDAP plugin for portable configuration engine (ARA)
 *
 * \author Mark Spencer <[email protected]>
 * \author Manuel Guesdon
 * \author Carl-Einar Thorner <[email protected]>
 * \author Russell Bryant <[email protected]>
 *
 * OpenLDAP http://www.openldap.org
 */

/*! \li \ref res_config_ldap.c uses the configuration file \ref res_ldap.conf
 * \addtogroup configuration_file Configuration Files
 */

/*!
 * \page res_ldap.conf res_ldap.conf
 * \verbinclude res_ldap.conf.sample
 */

/*** MODULEINFO
   <depend>ldap</depend>
   <support_level>extended</support_level>
 ***/

#include "asterisk.h"

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <ldap.h>

#include "asterisk/channel.h"
#include "asterisk/logger.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"
#include "asterisk/options.h"
#include "asterisk/cli.h"
#include "asterisk/utils.h"
#include "asterisk/strings.h"
#include "asterisk/pbx.h"
#include "asterisk/linkedlists.h"

#define RES_CONFIG_LDAP_CONF "res_ldap.conf"
#define RES_CONFIG_LDAP_DEFAULT_BASEDN "asterisk"

AST_MUTEX_DEFINE_STATIC(ldap_lock);

static LDAP *ldapConn;
static char url[512];
static char user[512];
static char pass[512];
static char base_distinguished_name[512];
static int version;
static time_t connect_time;

static int parse_config(void);
static int ldap_reconnect(void);
static char *realtime_ldap_status(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);

struct category_and_metric {
   const char *name;
   int metric;
   const char *variable_name;
   const char *variable_value;
   int var_metric; /*!< For organizing variables (particularly includes and switch statements) within a context */
};

/*! \brief Table configuration
 */
struct ldap_table_config {
   char *table_name;     /*!< table name */
   char *additional_filter;     /*!< additional filter   */
   struct ast_variable *attributes;  /*!< attribute names conversion */
   struct ast_variable *delimiters;  /*!< the current delimiter is semicolon, so we are not using this variable */
   AST_LIST_ENTRY(ldap_table_config) entry;
   /* TODO: Make proxies work */
};

/*! \brief Should be locked before using it
 */
static AST_LIST_HEAD_NOLOCK_STATIC(table_configs, ldap_table_config);
static struct ldap_table_config *base_table_config;
static struct ldap_table_config *static_table_config;

static struct ast_cli_entry ldap_cli[] = {
   AST_CLI_DEFINE(realtime_ldap_status, "Shows connection information for the LDAP RealTime driver"),
};

/*! \brief Create a new table_config
 */
static struct ldap_table_config *table_config_new(const char *table_name)
{
   struct ldap_table_config *p;

   if (!(p = ast_calloc(1, sizeof(*p))))
      return NULL;

   if (table_name) {
      if (!(p->table_name = ast_strdup(table_name))) {
         ast_free(p);
         return NULL;
      }
   }

   return p;
}

/*! \brief Find a table_config
 *
 * Should be locked before using it
 *
 *  \note This function assumes ldap_lock to be locked.
 */
static struct ldap_table_config *table_config_for_table_name(const char *table_name)
{
   struct ldap_table_config *c = NULL;

   AST_LIST_TRAVERSE(&table_configs, c, entry) {
      if (!strcmp(c->table_name, table_name))
         break;
   }

   return c;
}

/*! \brief Find variable by name
 */
static struct ast_variable *variable_named(struct ast_variable *var, const char *name)
{
   for (; var; var = var->next) {
      if (!strcasecmp(name, var->name))
         break;
   }

   return var;
}

/*! \brief Count  semicolons in string
 * \param somestr - pointer to a string
 *
 * \return number of occurances of the delimiter(semicolon)
 */
static int semicolon_count_str(const char *somestr)
{
   int count = 0;

   for (; *somestr; somestr++) {
      if (*somestr == ';')
         count++;
   }

   return count;
}

/* \brief Count semicolons in variables
 *
 * takes a linked list of \a ast_variable variables, finds the one with the name variable_value
 * and returns the number of semicolons in the value for that \a ast_variable
 */
static int semicolon_count_var(struct ast_variable *var)
{
   struct ast_variable *var_value = variable_named(var, "variable_value");

   if (!var_value) {
      return 0;
   }

   ast_debug(2, "semicolon_count_var: %s\n", var_value->value);

   return semicolon_count_str(var_value->value);
}

/*! \brief add attribute to table config
 *
 * Should be locked before using it
 */
static void ldap_table_config_add_attribute(struct ldap_table_config *table_config,
   const char *attribute_name, const char *attribute_value)
{
   struct ast_variable *var;

   if (ast_strlen_zero(attribute_name) || ast_strlen_zero(attribute_value)) {
      return;
   }

   if (!(var = ast_variable_new(attribute_name, attribute_value, table_config->table_name))) {
      return;
   }

   if (table_config->attributes) {
      var->next = table_config->attributes;
   }
   table_config->attributes = var;
}

/*! \brief Free table_config
 *
 * \note assumes ldap_lock to be locked
 */
static void table_configs_free(void)
{
   struct ldap_table_config *c;

   while ((c = AST_LIST_REMOVE_HEAD(&table_configs, entry))) {
      if (c->table_name) {
         ast_free(c->table_name);
      }
      if (c->additional_filter) {
         ast_free(c->additional_filter);
      }
      if (c->attributes) {
         ast_variables_destroy(c->attributes);
      }
      ast_free(c);
   }

   base_table_config = NULL;
   static_table_config = NULL;
}

/*! \brief Convert variable name to ldap attribute name
 *
 * \note Should be locked before using it
 */
static const char *convert_attribute_name_to_ldap(struct ldap_table_config *table_config,
   const char *attribute_name)
{
   int i = 0;
   struct ldap_table_config *configs[] = { table_config, base_table_config };

   for (i = 0; i < ARRAY_LEN(configs); i++) {
      struct ast_variable *attribute;

      if (!configs[i]) {
         continue;
      }

      attribute = configs[i]->attributes;
      for (; attribute; attribute = attribute->next) {
         if (!strcasecmp(attribute_name, attribute->name)) {
            return attribute->value;
         }
      }
   }

   return attribute_name;
}

/*! \brief Convert ldap attribute name to variable name
 *
 * \note Should be locked before using it
 */
static const char *convert_attribute_name_from_ldap(struct ldap_table_config *table_config,
                      const char *attribute_name)
{
   int i = 0;
   struct ldap_table_config *configs[] = { table_config, base_table_config };

   for (i = 0; i < ARRAY_LEN(configs); i++) {
      struct ast_variable *attribute;

      if (!configs[i]) {
         continue;
      }

      attribute = configs[i]->attributes;
      for (; attribute; attribute = attribute->next) {
         if (strcasecmp(attribute_name, attribute->value) == 0) {
            return attribute->name;
         }
      }
   }

   return attribute_name;
}

/*! \brief Get variables from ldap entry attributes
 * \note Should be locked before using it
 * \return a linked list of ast_variable variables.
 */
static struct ast_variable *realtime_ldap_entry_to_var(struct ldap_table_config *table_config,
   LDAPMessage *ldap_entry)
{
   BerElement *ber = NULL;
   struct ast_variable *var = NULL;
   struct ast_variable *prev = NULL;
#if 0
   int is_delimited = 0;
   int i = 0;
#endif
   char *ldap_attribute_name;
   struct berval *value;
   int pos = 0;

   ldap_attribute_name = ldap_first_attribute(ldapConn, ldap_entry, &ber);

   while (ldap_attribute_name) {
      struct berval **values = NULL;
      const char *attribute_name = convert_attribute_name_from_ldap(table_config, ldap_attribute_name);
      int is_realmed_password_attribute = strcasecmp(attribute_name, "md5secret") == 0;

      values = ldap_get_values_len(ldapConn, ldap_entry, ldap_attribute_name); /* these are freed at the end */
      if (values) {
         struct berval **v;
         char *valptr;

         for (v = values; *v; v++) {
            value = *v;
            valptr = value->bv_val;
            ast_debug(2, "attribute_name: %s LDAP value: %s\n", attribute_name, valptr);
            if (is_realmed_password_attribute) {
               if (!strncasecmp(valptr, "{md5}", 5)) {
                  valptr += 5;
               }
               ast_debug(2, "md5: %s\n", valptr);
            }
            if (valptr) {
#if 0
               /* ok, so looping through all delimited values except the last one (not, last character is not delimited...) */
               if (is_delimited) {
                  i = 0;
                  pos = 0;
                  while (!ast_strlen_zero(valptr + i)) {
                     if (valptr[i] == ';') {
                        valptr[i] = '\0';
                        if (prev) {
                           prev->next = ast_variable_new(attribute_name, &valptr[pos], table_config->table_name);
                           if (prev->next) {
                              prev = prev->next;
                           }
                        } else {
                           prev = var = ast_variable_new(attribute_name, &valptr[pos], table_config->table_name);
                        }
                        pos = i + 1;
                     }
                     i++;
                  }
               }
#endif
               /* for the last delimited value or if the value is not delimited: */
               if (prev) {
                  prev->next = ast_variable_new(attribute_name, &valptr[pos], table_config->table_name);
                  if (prev->next) {
                     prev = prev->next;
                  }
               } else {
                  prev = var = ast_variable_new(attribute_name, &valptr[pos], table_config->table_name);
               }
            }
         }
         ldap_value_free_len(values);
      }
      ldap_memfree(ldap_attribute_name);
      ldap_attribute_name = ldap_next_attribute(ldapConn, ldap_entry, ber);
   }
   ber_free(ber, 0);

   return var;
}

/*! \brief Get variables from ldap entry attributes - Should be locked before using it
 *
 * The results are freed outside this function so is the \a vars array.
 *
 * \return \a vars - an array of ast_variable variables terminated with a null.
 */
static struct ast_variable **realtime_ldap_result_to_vars(struct ldap_table_config *table_config,
   LDAPMessage *ldap_result_msg, unsigned int *entries_count_ptr)
{
   struct ast_variable **vars;
   int i = 0;
   int tot_count = 0;
   int entry_index = 0;
   LDAPMessage *ldap_entry = NULL;
   BerElement *ber = NULL;
   struct ast_variable *var = NULL;
   struct ast_variable *prev = NULL;
   int is_delimited = 0;
   char *delim_value = NULL;
   int delim_tot_count = 0;
   int delim_count = 0;

   /* \breif First find the total count
    */
   ldap_entry = ldap_first_entry(ldapConn, ldap_result_msg);

   for (tot_count = 0; ldap_entry; tot_count++) {
      struct ast_variable *tmp = realtime_ldap_entry_to_var(table_config, ldap_entry);
      tot_count += semicolon_count_var(tmp);
      ldap_entry = ldap_next_entry(ldapConn, ldap_entry);
      ast_variables_destroy(tmp);
   }

   if (entries_count_ptr) {
      *entries_count_ptr = tot_count;
   }

   /*! \note Now that we have the total count we allocate space and create the variables
    * Remember that each element in vars is a linked list that points to realtime variable.
    * If the we are dealing with a static realtime variable we create a new element in the \a vars array for each delimited
    * value in \a variable_value; otherwise, we keep \a vars static and increase the length of the linked list of variables in the array element.
    * This memory must be freed outside of this function.
    */
   vars = ast_calloc(tot_count + 1, sizeof(struct ast_variable *));

   ldap_entry = ldap_first_entry(ldapConn, ldap_result_msg);

   i = 0;

   /* \brief For each static realtime variable we may create several entries in the \a vars array if it's delimited
    */
   for (entry_index = 0; ldap_entry; ) {
      int pos = 0;
      delim_value = NULL;
      delim_tot_count = 0;
      delim_count = 0;

      do { /* while delim_count */

         /* Starting new static var */
         char *ldap_attribute_name = ldap_first_attribute(ldapConn, ldap_entry, &ber);
         struct berval *value;
         while (ldap_attribute_name) {
            const char *attribute_name = convert_attribute_name_from_ldap(table_config, ldap_attribute_name);
            int is_realmed_password_attribute = strcasecmp(attribute_name, "md5secret") == 0;
            struct berval **values = NULL;

            values = ldap_get_values_len(ldapConn, ldap_entry, ldap_attribute_name);
            if (values) {
               struct berval **v;
               char *valptr;

               for (v = values; *v; v++) {
                  value = *v;
                  valptr = value->bv_val;
                  if (is_realmed_password_attribute) {
                     if (strncasecmp(valptr, "{md5}", 5) == 0) {
                        valptr += 5;
                     }
                     ast_debug(2, "md5: %s\n", valptr);
                  }
                  if (valptr) {
                     if (delim_value == NULL && !is_realmed_password_attribute
                        && (static_table_config != table_config || strcmp(attribute_name, "variable_value") == 0)) {

                        delim_value = ast_strdup(valptr);

                        if ((delim_tot_count = semicolon_count_str(delim_value)) > 0) {
                           ast_debug(4, "is delimited %d times: %s\n", delim_tot_count, delim_value);
                           is_delimited = 1;
                        }
                     }

                     if (is_delimited != 0 && !is_realmed_password_attribute
                        && (static_table_config != table_config || strcmp(attribute_name, "variable_value") == 0) ) {
                        /* for non-Static RealTime, first */

                        for (i = pos; !ast_strlen_zero(valptr + i); i++) {
                           ast_debug(4, "DELIM pos: %d i: %d\n", pos, i);
                           if (delim_value[i] == ';') {
                              delim_value[i] = '\0';

                              ast_debug(2, "DELIM - attribute_name: %s value: %s pos: %d\n", attribute_name, &delim_value[pos], pos);

                              if (prev) {
                                 prev->next = ast_variable_new(attribute_name, &delim_value[pos], table_config->table_name);
                                 if (prev->next) {
                                    prev = prev->next;
                                 }
                              } else {
                                 prev = var = ast_variable_new(attribute_name, &delim_value[pos], table_config->table_name);
                              }
                              pos = i + 1;

                              if (static_table_config == table_config) {
                                 break;
                              }
                           }
                        }
                        if (ast_strlen_zero(valptr + i)) {
                           ast_debug(4, "DELIM pos: %d i: %d delim_count: %d\n", pos, i, delim_count);
                           /* Last delimited value */
                           ast_debug(4, "DELIM - attribute_name: %s value: %s pos: %d\n", attribute_name, &delim_value[pos], pos);
                           if (prev) {
                              prev->next = ast_variable_new(attribute_name, &delim_value[pos], table_config->table_name);
                              if (prev->next) {
                                 prev = prev->next;
                              }
                           } else {
                              prev = var = ast_variable_new(attribute_name, &delim_value[pos], table_config->table_name);
                           }
                           /* Remembering to free memory */
                           is_delimited = 0;
                           pos = 0;
                        }
                        ast_free(delim_value);
                        delim_value = NULL;

                        ast_debug(4, "DELIM pos: %d i: %d\n", pos, i);
                     } else {
                        /* not delimited */
                        if (delim_value) {
                           ast_free(delim_value);
                           delim_value = NULL;
                        }
                        ast_debug(2, "attribute_name: %s value: %s\n", attribute_name, valptr);

                        if (prev) {
                           prev->next = ast_variable_new(attribute_name, valptr, table_config->table_name);
                           if (prev->next) {
                              prev = prev->next;
                           }
                        } else {
                           prev = var = ast_variable_new(attribute_name, valptr, table_config->table_name);
                        }
                     }
                  }
               } /*!< for (v = values; *v; v++) */
               ldap_value_free_len(values);
            }/*!< if (values) */
            ldap_memfree(ldap_attribute_name);
            ldap_attribute_name = ldap_next_attribute(ldapConn, ldap_entry, ber);
         } /*!< while (ldap_attribute_name) */
         ber_free(ber, 0);
         if (static_table_config == table_config) {
            if (DEBUG_ATLEAST(3)) {
               const struct ast_variable *tmpdebug = variable_named(var, "variable_name");
               const struct ast_variable *tmpdebug2 = variable_named(var, "variable_value");
               if (tmpdebug && tmpdebug2) {
                  ast_log(LOG_DEBUG, "Added to vars - %s = %s\n", tmpdebug->value, tmpdebug2->value);
               }
            }
            vars[entry_index++] = var;
            prev = NULL;
         }

         delim_count++;
      } while (delim_count <= delim_tot_count && static_table_config == table_config);

      if (static_table_config != table_config) {
         ast_debug(3, "Added to vars - non static\n");

         vars[entry_index++] = var;
         prev = NULL;
      }
      ldap_entry = ldap_next_entry(ldapConn, ldap_entry);
   } /*!< end for loop over ldap_entry */

   return vars;
}


/*! \brief Check if we have a connection error
 */
static int is_ldap_connect_error(int err)
{
   return (err == LDAP_SERVER_DOWN || err == LDAP_TIMEOUT || err == LDAP_CONNECT_ERROR);
}

/*! \brief Get LDAP entry by dn and return attributes as variables
 *
 * Should be locked before using it
 *
 * This is used for setting the default values of an object
 * i.e., with accountBaseDN
*/
static struct ast_variable *ldap_loadentry(struct ldap_table_config *table_config,
                  const char *dn)
{
   if (!table_config) {
      ast_log(LOG_ERROR, "No table config\n");
      return NULL;
   } else {
      struct ast_variable **vars = NULL;
      struct ast_variable *var = NULL;
      int result = -1;
      LDAPMessage *ldap_result_msg = NULL;
      int tries = 0;

      ast_debug(2, "ldap_loadentry dn=%s\n", dn);

      do {
         result = ldap_search_ext_s(ldapConn, dn, LDAP_SCOPE_BASE,
                  "(objectclass=*)", NULL, 0, NULL, NULL, NULL, LDAP_NO_LIMIT, &ldap_result_msg);
         if (result != LDAP_SUCCESS && is_ldap_connect_error(result)) {
            ast_log(LOG_WARNING, "Failed to query directory. Try %d/3\n", tries + 1);
            tries++;
            if (tries < 3) {
               usleep(500000L * tries);
               if (ldapConn) {
                  ldap_unbind_ext_s(ldapConn, NULL, NULL);
                  ldapConn = NULL;
               }
               if (!ldap_reconnect()) {
                  break;
               }
            }
         }
      } while (result != LDAP_SUCCESS && tries < 3 && is_ldap_connect_error(result));

      if (result != LDAP_SUCCESS) {
         ast_log(LOG_WARNING, "Failed to query directory. Error: %s.\n", ldap_err2string(result));
         ast_debug(2, "dn=%s\n", dn);
         ast_mutex_unlock(&ldap_lock);
         return NULL;
      } else {
         int num_entry = 0;
         unsigned int *entries_count_ptr = NULL; /*!< not using this */

         if ((num_entry = ldap_count_entries(ldapConn, ldap_result_msg)) > 0) {
            ast_debug(3, "num_entry: %d\n", num_entry);

            vars = realtime_ldap_result_to_vars(table_config, ldap_result_msg, entries_count_ptr);
            if (num_entry > 1) {
               ast_log(LOG_NOTICE, "More than one entry for dn=%s. Take only 1st one\n", dn);
            }
         } else {
            ast_debug(2, "Could not find any entry dn=%s.\n", dn);
         }
      }
      ldap_msgfree(ldap_result_msg);

      /* Chopping \a vars down to one variable */
      if (vars != NULL) {
         struct ast_variable **p = vars;

         /* Only take the first one. */
         var = *vars;

         /* Destroy the rest. */
         while (*++p) {
            ast_variables_destroy(*p);
         }
         ast_free(vars);
      }

      return var;
   }
}

/*! \note caller should free returned pointer
 */
static char *substituted(struct ast_channel *channel, const char *string)
{
#define MAXRESULT 2048
   char *ret_string = NULL;

   if (!ast_strlen_zero(string)) {
      ret_string = ast_calloc(1, MAXRESULT);
      pbx_substitute_variables_helper(channel, string, ret_string, MAXRESULT - 1);
   }
   ast_debug(2, "substituted: string: '%s' => '%s' \n", string, ret_string);
   return ret_string;
}

/*! \note caller should free returned pointer
 */
static char *cleaned_basedn(struct ast_channel *channel, const char *basedn)
{
   char *cbasedn = NULL;
   if (basedn) {
      char *p = NULL;
      cbasedn = substituted(channel, basedn);
      if (*cbasedn == '"') {
         cbasedn++;
         if (!ast_strlen_zero(cbasedn)) {
            int len = strlen(cbasedn);
            if (cbasedn[len - 1] == '"')
               cbasedn[len - 1] = '\0';

         }
      }
      p = cbasedn;
      while (*p) {
         if (*p == '|')
            *p = ',';
         p++;
      }
   }
   ast_debug(2, "basedn: '%s' => '%s' \n", basedn, cbasedn);
   return cbasedn;
}

/*! \brief Replace <search> by <by> in string.
 * \note No check is done on string allocated size !
 */
static int replace_string_in_string(char *string, const char *search, const char *by)
{
   int search_len = strlen(search);
   int by_len = strlen(by);
   int replaced = 0;
   char *p = strstr(string, search);

   if (p) {
      replaced = 1;
      while (p) {
         if (by_len == search_len) {
            memcpy(p, by, by_len);
         } else {
            memmove(p + by_len, p + search_len, strlen(p + search_len) + 1);
            memcpy(p, by, by_len);
         }
         p = strstr(p + by_len, search);
      }
   }
   return replaced;
}

/*! \brief Append a name=value filter string. The filter string can grow.
 */
static void append_var_and_value_to_filter(struct ast_str **filter,
   struct ldap_table_config *table_config,
   const char *name, const char *value)
{
   char *new_name = NULL;
   char *new_value = NULL;
   char *like_pos = strstr(name, " LIKE");

   ast_debug(2, "name='%s' value='%s'\n", name, value);

   if (like_pos) {
      int len = like_pos - name;

      name = new_name = ast_strdupa(name);
      new_name[len] = '\0';
      value = new_value = ast_strdupa(value);
      replace_string_in_string(new_value, "\\_", "_");
      replace_string_in_string(new_value, "%", "*");
   }

   name = convert_attribute_name_to_ldap(table_config, name);

   ast_str_append(filter, 0, "(%s=%s)", name, value);
}

/*!
 * \internal
 * \brief Create an LDAP filter using search fields
 *
 * \param config the \c ldap_table_config for this search
 * \param fields the \c ast_variable criteria to include
 *
 * \returns an \c ast_str pointer on success, NULL otherwise.
 */
static struct ast_str *create_lookup_filter(struct ldap_table_config *config, const struct ast_variable *fields)
{
   struct ast_str *filter;
   const struct ast_variable *field;

   filter = ast_str_create(80);
   if (!filter) {
      return NULL;
   }

   /*
    * Create the filter with the table additional filter and the
    * parameter/value pairs we were given
    */
   ast_str_append(&filter, 0, "(&");
   if (config && config->additional_filter) {
      ast_str_append(&filter, 0, "%s", config->additional_filter);
   }
   if (config != base_table_config
      && base_table_config
      && base_table_config->additional_filter) {
      ast_str_append(&filter, 0, "%s", base_table_config->additional_filter);
   }
   /* Append the lookup fields */
   for (field = fields; field; field = field->next) {
      append_var_and_value_to_filter(&filter, config, field->name, field->value);
   }
   ast_str_append(&filter, 0, ")");

   return filter;
}

/*! \brief LDAP base function
 * \return a null terminated array of ast_variable (one per entry) or NULL if no entry is found or if an error occured
 * caller should free the returned array and ast_variables
 * \param entries_count_ptr is a pointer to found entries count (can be NULL)
 * \param basedn is the base DN
 * \param table_name is the table_name (used dor attribute convertion and additional filter)
 * \param fields contains list of pairs name/value
*/
static struct ast_variable **realtime_ldap_base_ap(unsigned int *entries_count_ptr,
   const char *basedn, const char *table_name, const struct ast_variable *fields)
{
   struct ast_variable **vars = NULL;
   const struct ast_variable *field = fields;
   struct ldap_table_config *table_config = NULL;
   char *clean_basedn = cleaned_basedn(NULL, basedn);
   struct ast_str *filter = NULL;
   int tries = 0;
   int result = 0;
   LDAPMessage *ldap_result_msg = NULL;

   if (!table_name) {
      ast_log(LOG_ERROR, "No table_name specified.\n");
      ast_free(clean_basedn);
      return NULL;
   }

   if (!field) {
      ast_log(LOG_ERROR, "Realtime retrieval requires at least 1 parameter"
         " and 1 value to search on.\n");
      ast_free(clean_basedn);
      return NULL;
   }

   ast_mutex_lock(&ldap_lock);

   /* We now have our complete statement; Lets connect to the server and execute it.  */
   if (!ldap_reconnect()) {
      ast_mutex_unlock(&ldap_lock);
      ast_free(clean_basedn);
      return NULL;
   }

   table_config = table_config_for_table_name(table_name);
   if (!table_config) {
      ast_log(LOG_WARNING, "No table named '%s'.\n", table_name);
      ast_mutex_unlock(&ldap_lock);
      ast_free(clean_basedn);
      return NULL;
   }

   filter = create_lookup_filter(table_config, fields);
   if (!filter) {
      ast_mutex_unlock(&ldap_lock);
      ast_free(clean_basedn);
      return NULL;
   }

   do {
      /* freeing ldap_result further down */
      result = ldap_search_ext_s(ldapConn, clean_basedn,
              LDAP_SCOPE_SUBTREE, ast_str_buffer(filter), NULL, 0, NULL, NULL, NULL, LDAP_NO_LIMIT,
              &ldap_result_msg);
      if (result != LDAP_SUCCESS && is_ldap_connect_error(result)) {
         ast_debug(1, "Failed to query directory. Try %d/10\n", tries + 1);
         if (++tries < 10) {
            usleep(1);
            if (ldapConn) {
               ldap_unbind_ext_s(ldapConn, NULL, NULL);
               ldapConn = NULL;
            }
            if (!ldap_reconnect()) {
               break;
            }
         }
      }
   } while (result != LDAP_SUCCESS && tries < 10 && is_ldap_connect_error(result));

   if (result != LDAP_SUCCESS) {
      ast_log(LOG_WARNING, "Failed to query directory. Error: %s.\n", ldap_err2string(result));
      ast_log(LOG_WARNING, "Query: %s\n", ast_str_buffer(filter));
   } else {
      /* this is where we create the variables from the search result
       * freeing this \a vars outside this function */
      if (ldap_count_entries(ldapConn, ldap_result_msg) > 0) {
         /* is this a static var or some other? they are handled different for delimited values */
         vars = realtime_ldap_result_to_vars(table_config, ldap_result_msg, entries_count_ptr);
      } else {
         ast_debug(1, "Could not find any entry matching %s in base dn %s.\n", ast_str_buffer(filter), clean_basedn);
      }

      ldap_msgfree(ldap_result_msg);

      /*! \TODO get the default variables from the accountBaseDN, not implemented with delimited values
       */
      if (vars) {
         struct ast_variable **p = vars;
         while (*p) {
            struct ast_variable *append_var = NULL;
            struct ast_variable *tmp = *p;
            while (tmp) {
               if (strcasecmp(tmp->name, "accountBaseDN") == 0) {
                  /* Get the variable to compare with for the defaults */
                  struct ast_variable *base_var = ldap_loadentry(table_config, tmp->value);

                  while (base_var) {
                     struct ast_variable *next = base_var->next;
                     struct ast_variable *test_var = *p;
                     int base_var_found = 0;

                     /* run throught the default values and fill it inn if it is missing */
                     while (test_var) {
                        if (strcasecmp(test_var->name, base_var->name) == 0) {
                           base_var_found = 1;
                           break;
                        } else {
                           test_var = test_var->next;
                        }
                     }
                     if (base_var_found) {
                        base_var->next = NULL;
                        ast_variables_destroy(base_var);
                        base_var = next;
                     } else {
                        /*!
                         * \todo XXX The interactions with base_var and append_var may
                         * cause a memory leak of base_var nodes.  Also the append_var
                         * list and base_var list may get cross linked.
                         */
                        if (append_var) {
                           base_var->next = append_var;
                        } else {
                           base_var->next = NULL;
                        }
                        append_var = base_var;
                        base_var = next;
                     }
                  }
               }
               if (!tmp->next && append_var) {
                  tmp->next = append_var;
                  tmp = NULL;
               } else {
                  tmp = tmp->next;
               }
            }
            p++;
         }
      }
   }

   ast_free(filter);
   ast_free(clean_basedn);

   ast_mutex_unlock(&ldap_lock);

   return vars;
}

static struct ast_variable *realtime_arguments_to_fields(va_list ap)
{
   struct ast_variable *fields = NULL;
   const char *newparam, *newval;

   while ((newparam = va_arg(ap, const char *))) {
      struct ast_variable *field;

      newval = va_arg(ap, const char *);
      if (!(field = ast_variable_new(newparam, newval, ""))) {
         ast_variables_destroy(fields);
         return NULL;
      }

      field->next = fields;
      fields = field;
   }

   return fields;
}

/*! \brief same as realtime_ldap_base_ap but take variable arguments count list
 */
static struct ast_variable **realtime_ldap_base(unsigned int *entries_count_ptr,
   const char *basedn, const char *table_name, ...)
{
   RAII_VAR(struct ast_variable *, fields, NULL, ast_variables_destroy);
   struct ast_variable **vars = NULL;
   va_list ap;

   va_start(ap, table_name);
   fields = realtime_arguments_to_fields(ap);
   va_end(ap);

   vars = realtime_ldap_base_ap(entries_count_ptr, basedn, table_name, fields);

   return vars;
}

/*! \brief See Asterisk doc
 *
 * For Realtime Dynamic(i.e., switch, queues, and directory)
 */
static struct ast_variable *realtime_ldap(const char *basedn,
                 const char *table_name, const struct ast_variable *fields)
{
   struct ast_variable **vars = realtime_ldap_base_ap(NULL, basedn, table_name, fields);
   struct ast_variable *var = NULL;

   if (vars) {
      struct ast_variable *last_var = NULL;
      struct ast_variable **p = vars;

      /* Chain the vars array of lists into one list to return. */
      while (*p) {
         if (last_var) {
            while (last_var->next) {
               last_var = last_var->next;
            }
            last_var->next = *p;
         } else {
            var = *p;
            last_var = var;
         }
         p++;
      }
      ast_free(vars);
   }
   return var;
}

/*! \brief See Asterisk doc
 *
 * this function will be called for the switch statement if no match is found with the realtime_ldap function(i.e. it is a failover);
 * however, the ast_load_realtime wil match on wildcharacters also depending on what the mode is set to
 * this is an area of asterisk that could do with a lot of modification
 * I think this function returns Realtime dynamic objects
 */
static struct ast_config *realtime_multi_ldap(const char *basedn,
      const char *table_name, const struct ast_variable *fields)
{
   char *op;
   const char *initfield = NULL;
   struct ast_variable **vars =
      realtime_ldap_base_ap(NULL, basedn, table_name, fields);
   struct ast_config *cfg = NULL;

   if (!fields) {
       ast_log(LOG_WARNING, "realtime retrieval requires at least 1 parameter and 1 value to search on.\n");
       return NULL;
   }
   initfield = ast_strdupa(fields->name);
   if ((op = strchr(initfield, ' '))) {
      *op = '\0';
   }

   if (vars) {
      cfg = ast_config_new();
      if (!cfg) {
         ast_log(LOG_ERROR, "Unable to create a config!\n");
      } else {
         struct ast_variable **p = vars;

         while (*p) {
            struct ast_category *cat = ast_category_new_anonymous();
            if (!cat) {
               break;
            } else {
               struct ast_variable *var = *p;
               while (var) {
                  struct ast_variable *next = var->next;
                  if (initfield && !strcmp(initfield, var->name)) {
                     ast_category_rename(cat, var->value);
                  }
                  var->next = NULL;
                  ast_variable_append(cat, var);
                  var = next;
               }
            }
            ast_category_append(cfg, cat);
            p++;
         }
      }
      ast_free(vars);
   }
   return cfg;

}

/*! \brief Sorting alogrithm for qsort to find the order of the variables \a a and \a b
 * \param a pointer to category_and_metric struct
 * \param b pointer to category_and_metric struct
 *
 * \retval -1 for if b is greater
 * \retval 0 zero for equal
 * \retval 1 if a is greater
 */
static int compare_categories(const void *a, const void *b)
{
   const struct category_and_metric *as = a;
   const struct category_and_metric *bs = b;

   if (as->metric < bs->metric) {
      return -1;
   } else if (as->metric > bs->metric) {
      return 1;
   } else if (as->metric == bs->metric && strcmp(as->name, bs->name) != 0) {
      return strcmp(as->name, bs->name);
   }
   /* if the metric and the category name is the same, we check the variable metric */
   if (as->var_metric < bs->var_metric) {
      return -1;
   } else if (as->var_metric > bs->var_metric) {
      return 1;
   }

   return 0;
}

/*! \brief See Asterisk Realtime Documentation
 *
 * This is for Static Realtime
 *
 * load the configuration stuff for the .conf files
 * called on a reload
 */
static struct ast_config *config_ldap(const char *basedn, const char *table_name,
   const char *file, struct ast_config *cfg, struct ast_flags config_flags, const char *sugg_incl, const char *who_asked)
{
   unsigned int vars_count = 0;
   struct ast_variable **vars;
   int i = 0;
   struct ast_variable *new_v = NULL;
   struct ast_category *cur_cat = NULL;
   const char *last_category = NULL;
   int last_category_metric = 0;
   struct category_and_metric *categories;
   struct ast_variable **p;

   if (ast_strlen_zero(file) || !strcasecmp(file, RES_CONFIG_LDAP_CONF)) {
      ast_log(LOG_ERROR, "Missing configuration file: %s. Can't configure myself.\n", RES_CONFIG_LDAP_CONF);
      return NULL;
   }

   vars = realtime_ldap_base(&vars_count, basedn, table_name, "filename", file, "commented", "FALSE", NULL);

   if (!vars) {
      ast_log(LOG_WARNING, "Could not find config '%s' in directory.\n", file);
      return NULL;
   }

   /*! \note Since the items come back in random order, they need to be sorted
    * first, and since the data could easily exceed stack size, this is
    * allocated from the heap.
    */
   if (!(categories = ast_calloc(vars_count, sizeof(*categories)))) {
      return NULL;
   }

   for (vars_count = 0, p = vars; *p; p++) {
      struct ast_variable *category = variable_named(*p, "category");
      struct ast_variable *cat_metric = variable_named(*p, "cat_metric");
      struct ast_variable *var_name = variable_named(*p, "variable_name");
      struct ast_variable *var_val = variable_named(*p, "variable_value");
      struct ast_variable *var_metric = variable_named(*p, "var_metric");
      struct ast_variable *dn = variable_named(*p, "dn");

      if (!category) {
         ast_log(LOG_ERROR, "No category name in entry '%s'  for file '%s'.\n",
               (dn ? dn->value : "?"), file);
      } else if (!cat_metric) {
         ast_log(LOG_ERROR, "No category metric in entry '%s'(category: %s) for file '%s'.\n",
               (dn ? dn->value : "?"), category->value, file);
      } else if (!var_metric) {
         ast_log(LOG_ERROR, "No variable metric in entry '%s'(category: %s) for file '%s'.\n",
               (dn ? dn->value : "?"), category->value, file);
      } else if (!var_name) {
         ast_log(LOG_ERROR, "No variable name in entry '%s' (category: %s metric: %s) for file '%s'.\n",
               (dn ? dn->value : "?"), category->value,
               cat_metric->value, file);
      } else if (!var_val) {
         ast_log(LOG_ERROR, "No variable value in entry '%s' (category: %s metric: %s variable: %s) for file '%s'.\n",
               (dn ? dn->value : "?"), category->value,
               cat_metric->value, var_name->value, file);
      } else {
         categories[vars_count].name = category->value;
         categories[vars_count].metric = atoi(cat_metric->value);
         categories[vars_count].variable_name = var_name->value;
         categories[vars_count].variable_value = var_val->value;
         categories[vars_count].var_metric = atoi(var_metric->value);
         vars_count++;
      }

      ast_debug(3, "category: %s\n", category->value);
      ast_debug(3, "var_name: %s\n", var_name->value);
      ast_debug(3, "var_val: %s\n", var_val->value);
      ast_debug(3, "cat_metric: %s\n", cat_metric->value);

   }

   qsort(categories, vars_count, sizeof(*categories), compare_categories);

   for (i = 0; i < vars_count; i++) {
      if (!strcmp(categories[i].variable_name, "#include")) {
         struct ast_flags flags = { 0 };
         if (!ast_config_internal_load(categories[i].variable_value, cfg, flags, "", who_asked)) {
            break;
         }
         continue;
      }

      if (!last_category || strcmp(last_category, categories[i].name) ||
         last_category_metric != categories[i].metric) {

         cur_cat = ast_category_new_dynamic(categories[i].name);
         if (!cur_cat) {
            break;
         }
         last_category = categories[i].name;
         last_category_metric = categories[i].metric;
         ast_category_append(cfg, cur_cat);
      }

      if (!(new_v = ast_variable_new(categories[i].variable_name, categories[i].variable_value, table_name))) {
         break;
      }

      ast_variable_append(cur_cat, new_v);
   }

   ast_free(vars);
   ast_free(categories);

   return cfg;
}

/*!
 * \internal
 * \brief Create an LDAP modification structure (LDAPMod)
 *
 * \param attribute the name of the LDAP attribute to modify
 * \param new_value the new value of the LDAP attribute
 *
 * \returns an LDAPMod * if successful, NULL otherwise.
 */
static LDAPMod *ldap_mod_create(const char *attribute, const char *new_value)
{
   LDAPMod *mod;
   char *type;

   mod = ldap_memcalloc(1, sizeof(LDAPMod));
   type = ldap_strdup(attribute);

   if (!(mod && type)) {
      ast_log(LOG_ERROR, "Memory allocation failure creating LDAP modification\n");
      ldap_memfree(type);
      ldap_memfree(mod);
      return NULL;
   }

   mod->mod_type = type;

   if (strlen(new_value)) {
      char **values, *value;
      values = ldap_memcalloc(2, sizeof(char *));
      value = ldap_strdup(new_value);

      if (!(values && value)) {
         ast_log(LOG_ERROR, "Memory allocation failure creating LDAP modification\n");
         ldap_memfree(value);
         ldap_memfree(values);
         ldap_memfree(type);
         ldap_memfree(mod);
         return NULL;
      }

      mod->mod_op = LDAP_MOD_REPLACE;
      mod->mod_values = values;
      mod->mod_values[0] = value;
   } else {
      mod->mod_op = LDAP_MOD_DELETE;
   }

   return mod;
}

/*!
 * \internal
 * \brief Append a value to an existing LDAP modification structure
 *
 * \param src the LDAPMod to update
 * \param new_value the new value to append to the LDAPMod
 *
 * \returns the \c src original passed in if successful, NULL otherwise.
 */
static LDAPMod *ldap_mod_append(LDAPMod *src, const char *new_value)
{
   char *new_buffer;

   if (src->mod_op != LDAP_MOD_REPLACE) {
      return src;
   }

   new_buffer = ldap_memrealloc(
         src->mod_values[0],
         strlen(src->mod_values[0]) + strlen(new_value) + sizeof(";"));

   if (!new_buffer) {
      ast_log(LOG_ERROR, "Memory allocation failure creating LDAP modification\n");
      return NULL;
   }

   strcat(new_buffer, ";");
   strcat(new_buffer, new_value);

   src->mod_values[0] = new_buffer;

   return src;
}

/*!
 * \internal
 * \brief Duplicates an LDAP modification structure
 *
 * \param src the LDAPMod to duplicate
 *
 * \returns a deep copy of \c src if successful, NULL otherwise.
 */
static LDAPMod *ldap_mod_duplicate(const LDAPMod *src)
{
   LDAPMod *mod;
   char *type, **values = NULL;

   mod = ldap_memcalloc(1, sizeof(LDAPMod));
   type = ldap_strdup(src->mod_type);

   if (!(mod && type)) {
      ast_log(LOG_ERROR, "Memory allocation failure creating LDAP modification\n");
      ldap_memfree(type);
      ldap_memfree(mod);
      return NULL;
   }

   if (src->mod_op == LDAP_MOD_REPLACE) {
      char *value;

      values = ldap_memcalloc(2, sizeof(char *));
      value = ldap_strdup(src->mod_values[0]);

      if (!(values && value)) {
         ast_log(LOG_ERROR, "Memory allocation failure creating LDAP modification\n");
         ldap_memfree(value);
         ldap_memfree(values);
         ldap_memfree(type);
         ldap_memfree(mod);
         return NULL;
      }

      values[0] = value;
   }

   mod->mod_op = src->mod_op;
   mod->mod_type = type;
   mod->mod_values = values;
   return mod;
}

/*!
 * \internal
 * \brief Search for an existing LDAP modification structure
 *
 * \param modifications a NULL terminated array of LDAP modification structures
 * \param lookup the attribute name to search for
 *
 * \returns an LDAPMod * if successful, NULL otherwise.
 */
static LDAPMod *ldap_mod_find(LDAPMod **modifications, const char *lookup)
{
   size_t i;
   for (i = 0; modifications[i]; i++) {
      if (modifications[i]->mod_op == LDAP_MOD_REPLACE &&
         !strcasecmp(modifications[i]->mod_type, lookup)) {
         return modifications[i];
      }
   }
   return NULL;
}

/*!
 * \internal
 * \brief Determine if an LDAP entry has the specified attribute
 *
 * \param entry the LDAP entry to examine
 * \param lookup the attribute name to search for
 *
 * \returns 1 if the attribute was found, 0 otherwise.
 */
static int ldap_entry_has_attribute(LDAPMessage *entry, const char *lookup)
{
   BerElement *ber = NULL;
   char *attribute;

   attribute = ldap_first_attribute(ldapConn, entry, &ber);
   while (attribute) {
      if (!strcasecmp(attribute, lookup)) {
         ldap_memfree(attribute);
         ber_free(ber, 0);
         return 1;
      }
      ldap_memfree(attribute);
      attribute = ldap_next_attribute(ldapConn, entry, ber);
   }
   ber_free(ber, 0);
   return 0;
}

/*!
 * \internal
 * \brief Remove LDAP_MOD_DELETE modifications that will not succeed
 *
 * \details
 * A LDAP_MOD_DELETE operation will fail if the LDAP entry does not already have
 * the corresponding attribute. Because we may be updating multiple LDAP entries
 * in a single call to update_ldap(), we may need our own copy of the
 * modifications array for each one.
 *
 * \note
 * This function dynamically allocates memory. If it returns a non-NULL pointer,
 * it is up to the caller to free it with ldap_mods_free()
 *
 * \returns an LDAPMod * if modifications needed to be removed, NULL otherwise.
 */
static LDAPMod **massage_mods_for_entry(LDAPMessage *entry, LDAPMod **mods)
{
   size_t k, i, remove_count;
   LDAPMod **copies;

   for (i = remove_count = 0; mods[i]; i++) {
      if (mods[i]->mod_op == LDAP_MOD_DELETE
         && !ldap_entry_has_attribute(entry, mods[i]->mod_type)) {
         remove_count++;
      }
   }

   if (!remove_count) {
      return NULL;
   }

   copies = ldap_memcalloc(i - remove_count + 1, sizeof(LDAPMod *));
   if (!copies) {
      ast_log(LOG_ERROR, "Memory allocation failure massaging LDAP modification\n");
      return NULL;
   }

   for (i = k = 0; mods[i]; i++) {
      if (mods[i]->mod_op != LDAP_MOD_DELETE
         || ldap_entry_has_attribute(entry, mods[i]->mod_type)) {
         copies[k] = ldap_mod_duplicate(mods[i]);
         if (!copies[k]) {
            ast_log(LOG_ERROR, "Memory allocation failure massaging LDAP modification\n");
            ldap_mods_free(copies, 1);
            return NULL;
         }
         k++;
      } else {
         ast_debug(3, "Skipping %s deletion because it doesn't exist\n",
               mods[i]->mod_type);
      }
   }

   return copies;
}

/*!
 * \internal
 * \brief Count the number of variables in an ast_variables list
 *
 * \param vars the list of variables to count
 *
 * \returns the number of variables in the specified list
 */
static size_t variables_count(const struct ast_variable *vars)
{
   const struct ast_variable *var;
   size_t count = 0;
   for (var = vars; var; var = var->next) {
      count++;
   }
   return count;
}

static int update2_ldap(const char *basedn, const char *table_name, const struct ast_variable *lookup_fields, const struct ast_variable *update_fields)
{
   const struct ast_variable *field;
   struct ldap_table_config *table_config = NULL;
   char *clean_basedn = NULL;
   struct ast_str *filter = NULL;
   int search_result = 0;
   int res = -1;
   int tries = 0;
   size_t update_count, update_index, entry_count;

   LDAPMessage *ldap_entry = NULL;
   LDAPMod **modifications;
   LDAPMessage *ldap_result_msg = NULL;

   if (!table_name) {
      ast_log(LOG_ERROR, "No table_name specified.\n");
      return res;
   }

   update_count = variables_count(update_fields);
   if (!update_count) {
      ast_log(LOG_WARNING, "Need at least one parameter to modify.\n");
      return res;
   }

   ast_mutex_lock(&ldap_lock);

   /* We now have our complete statement; Lets connect to the server and execute it.  */
   if (!ldap_reconnect()) {
      ast_mutex_unlock(&ldap_lock);
      return res;
   }

   table_config = table_config_for_table_name(table_name);
   if (!table_config) {
      ast_log(LOG_ERROR, "No table named '%s'.\n", table_name);
      ast_mutex_unlock(&ldap_lock);
      return res;
   }

   clean_basedn = cleaned_basedn(NULL, basedn);

   filter = create_lookup_filter(table_config, lookup_fields);
   if (!filter) {
      ast_mutex_unlock(&ldap_lock);
      ast_free(clean_basedn);
      return res;
   }

   /*
    * Find LDAP records that match our lookup filter. If there are none, then
    * we don't go through the hassle of building our modifications list.
    */

   do {
      search_result = ldap_search_ext_s(
            ldapConn,
            clean_basedn,
            LDAP_SCOPE_SUBTREE,
            ast_str_buffer(filter),
            NULL, 0, NULL, NULL, NULL,
            LDAP_NO_LIMIT,
            &ldap_result_msg);
      if (search_result != LDAP_SUCCESS && is_ldap_connect_error(search_result)) {
         ast_log(LOG_WARNING, "Failed to query directory. Try %d/3\n", tries + 1);
         tries++;
         if (tries < 3) {
            usleep(500000L * tries);
            if (ldapConn) {
               ldap_unbind_ext_s(ldapConn, NULL, NULL);
               ldapConn = NULL;
            }
            if (!ldap_reconnect()) {
               break;
            }
         }
      }
   } while (search_result != LDAP_SUCCESS && tries < 3 && is_ldap_connect_error(search_result));

   if (search_result != LDAP_SUCCESS) {
      ast_log(LOG_WARNING, "Failed to query directory. Error: %s.\n", ldap_err2string(search_result));
      ast_log(LOG_WARNING, "Query: %s\n", ast_str_buffer(filter));
      goto early_bailout;
   }

   entry_count = ldap_count_entries(ldapConn, ldap_result_msg);
   if (!entry_count) {
      /* Nothing found, nothing to update */
      res = 0;
      goto early_bailout;
   }

   /* We need to NULL terminate, so we allocate one more than we need */
   modifications = ldap_memcalloc(update_count + 1, sizeof(LDAPMod *));
   if (!modifications) {
      ast_log(LOG_ERROR, "Memory allocation failure\n");
      goto early_bailout;
   }

   /*
    * Create the modification array with the parameter/value pairs we were given,
    * if there are several parameters with the same name, we collect them into
    * one parameter/value pair and delimit them with a semicolon
    */
   for (field = update_fields, update_index = 0; field; field = field->next) {
      LDAPMod *mod;

      const char *ldap_attribute_name = convert_attribute_name_to_ldap(
            table_config,
            field->name);

      /* See if we already have it */
      mod = ldap_mod_find(modifications, ldap_attribute_name);
      if (mod) {
         mod = ldap_mod_append(mod, field->value);
         if (!mod) {
            goto late_bailout;
         }
      } else {
         mod = ldap_mod_create(ldap_attribute_name, field->value);
         if (!mod) {
            goto late_bailout;
         }
         modifications[update_index++] = mod;
      }
   }

   /* Ready to update */
   ast_debug(3, "Modifying %zu matched entries\n", entry_count);
   if (DEBUG_ATLEAST(3)) {
      size_t i;
      for (i = 0; modifications[i]; i++) {
         if (modifications[i]->mod_op != LDAP_MOD_DELETE) {
            ast_log(LOG_DEBUG, "%s => %s\n", modifications[i]->mod_type,
               modifications[i]->mod_values[0]);
         } else {
            ast_log(LOG_DEBUG, "deleting %s\n", modifications[i]->mod_type);
         }
      }
   }

   for (ldap_entry = ldap_first_entry(ldapConn, ldap_result_msg);
      ldap_entry;
      ldap_entry = ldap_next_entry(ldapConn, ldap_entry)) {
      int error;
      LDAPMod **massaged, **working;

      char *dn = ldap_get_dn(ldapConn, ldap_entry);
      if (!dn) {
         ast_log(LOG_ERROR, "Memory allocation failure\n");
         goto late_bailout;
      }

      working = modifications;

      massaged = massage_mods_for_entry(ldap_entry, modifications);
      if (massaged) {
         /* Did we massage everything out of the list? */
         if (!massaged[0]) {
            ast_debug(3, "Nothing left to modify - skipping\n");
            ldap_mods_free(massaged, 1);
            ldap_memfree(dn);
            continue;
         }
         working = massaged;
      }

      if ((error = ldap_modify_ext_s(ldapConn, dn, working, NULL, NULL)) != LDAP_SUCCESS)  {
         ast_log(LOG_ERROR, "Couldn't modify dn:%s because %s", dn, ldap_err2string(error));
      }

      if (massaged) {
         ldap_mods_free(massaged, 1);
      }

      ldap_memfree(dn);
   }

   res = entry_count;

late_bailout:
   ldap_mods_free(modifications, 1);

early_bailout:
   ldap_msgfree(ldap_result_msg);
   ast_free(filter);
   ast_free(clean_basedn);
   ast_mutex_unlock(&ldap_lock);

   return res;
}

static int update_ldap(const char *basedn, const char *table_name, const char *attribute, const char *lookup, const struct ast_variable *fields)
{
   int res;
   struct ast_variable *lookup_fields = ast_variable_new(attribute, lookup, "");
   res = update2_ldap(basedn, table_name, lookup_fields, fields);
   ast_variables_destroy(lookup_fields);
   return res;
}

static struct ast_config_engine ldap_engine = {
   .name = "ldap",
   .load_func = config_ldap,
   .realtime_func = realtime_ldap,
   .realtime_multi_func = realtime_multi_ldap,
   .update_func = update_ldap,
   .update2_func = update2_ldap,
};

/*!
 * \brief Load the module
 *
 * Module loading including tests for configuration or dependencies.
 * This function can return AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_DECLINE,
 * or AST_MODULE_LOAD_SUCCESS. If a dependency or environment variable fails
 * tests return AST_MODULE_LOAD_FAILURE. If the module can not load the
 * configuration file or other non-critical problem return
 * AST_MODULE_LOAD_DECLINE. On success return AST_MODULE_LOAD_SUCCESS.
 *
 * \todo Don't error or warn on a default install. If the config is
 * default we should not attempt to connect to a server. -lathama
 */
static int load_module(void)
{
   if (parse_config() < 0) {
      ast_log(LOG_ERROR, "Cannot load LDAP RealTime driver.\n");
      return 0;
   }

   ast_mutex_lock(&ldap_lock);

   if (!ldap_reconnect())  {
      ast_log(LOG_WARNING, "Couldn't establish connection to LDAP directory. Check debug.\n");
   }

   ast_config_engine_register(&ldap_engine);
   ast_verb(1, "LDAP RealTime driver loaded.\n");
   ast_cli_register_multiple(ldap_cli, ARRAY_LEN(ldap_cli));

   ast_mutex_unlock(&ldap_lock);

   return 0;
}

/*! \brief Unload Module
 *
 */
static int unload_module(void)
{
   /* Aquire control before doing anything to the module itself. */
   ast_mutex_lock(&ldap_lock);

   table_configs_free();

   if (ldapConn) {
      ldap_unbind_ext_s(ldapConn, NULL, NULL);
      ldapConn = NULL;
   }
   ast_cli_unregister_multiple(ldap_cli, ARRAY_LEN(ldap_cli));
   ast_config_engine_deregister(&ldap_engine);
   ast_verb(1, "LDAP RealTime driver unloaded.\n");

   /* Unlock so something else can destroy the lock. */
   ast_mutex_unlock(&ldap_lock);

   return 0;
}

/*! \breif Relod Module
 */
static int reload(void)
{
   /* Aquire control before doing anything to the module itself. */
   ast_mutex_lock(&ldap_lock);

   if (ldapConn) {
      ldap_unbind_ext_s(ldapConn, NULL, NULL);
      ldapConn = NULL;
   }

   if (parse_config() < 0) {
      ast_log(LOG_NOTICE, "Cannot reload LDAP RealTime driver.\n");
      ast_mutex_unlock(&ldap_lock);
      return 0;
   }

   if (!ldap_reconnect())  {
      ast_log(LOG_WARNING, "Couldn't establish connection to your directory server. Check debug.\n");
   }

   ast_verb(2, "LDAP RealTime driver reloaded.\n");

   /* Done reloading. Release lock so others can now use driver. */
   ast_mutex_unlock(&ldap_lock);

   return 0;
}

static int config_can_be_inherited(const char *key)
{
   int i;
   static const char * const config[] = {
      "basedn", "host", "pass", "port", "protocol", "url", "user", "version", NULL
   };

   for (i = 0; config[i]; i++) {
      if (!strcasecmp(key, config[i])) {
         return 0;
      }
   }
   return 1;
}

/*! \brief parse the configuration file
 */
static int parse_config(void)
{
   struct ast_config *config;
   struct ast_flags config_flags = {0};
   const char *s, *host;
   int port;
   char *category_name = NULL;

   /* Make sure that global variables are reset */
   url[0] = '\0';
   user[0] = '\0';
   pass[0] = '\0';
   base_distinguished_name[0] = '\0';
   version = 3;

   config = ast_config_load(RES_CONFIG_LDAP_CONF, config_flags);
   if (config == CONFIG_STATUS_FILEMISSING || config == CONFIG_STATUS_FILEINVALID) {
      ast_log(LOG_ERROR, "Cannot load configuration file: %s\n", RES_CONFIG_LDAP_CONF);
      return -1;
   }

   if (!(s = ast_variable_retrieve(config, "_general", "user"))) {
      ast_log(LOG_NOTICE, "No directory user found, anonymous binding as default.\n");
      user[0] = '\0';
   } else {
      ast_copy_string(user, s, sizeof(user));
   }

   if (!ast_strlen_zero(user)) {
      if (!(s = ast_variable_retrieve(config, "_general", "pass"))) {
         ast_log(LOG_WARNING, "No directory password found, using 'asterisk' as default.\n");
         ast_copy_string(pass, "asterisk", sizeof(pass));
      } else {
         ast_copy_string(pass, s, sizeof(pass));
      }
   }

   /* URL is preferred, use host and port if not found */
   if ((s = ast_variable_retrieve(config, "_general", "url"))) {
      ast_copy_string(url, s, sizeof(url));
   } else if ((host = ast_variable_retrieve(config, "_general", "host"))) {
      if (!(s = ast_variable_retrieve(config, "_general", "port")) || sscanf(s, "%5d", &port) != 1 || port > 65535) {
         ast_log(LOG_NOTICE, "No directory port found, using 389 as default.\n");
         port = 389;
      }

      snprintf(url, sizeof(url), "ldap://%s:%d", host, port);
   } else {
      ast_log(LOG_ERROR, "No directory URL or host found.\n");
      ast_config_destroy(config);
      return -1;
   }

   if (!(s = ast_variable_retrieve(config, "_general", "basedn"))) {
      ast_log(LOG_ERROR, "No LDAP base dn found, using '%s' as default.\n", RES_CONFIG_LDAP_DEFAULT_BASEDN);
      ast_copy_string(base_distinguished_name, RES_CONFIG_LDAP_DEFAULT_BASEDN, sizeof(base_distinguished_name));
   } else
      ast_copy_string(base_distinguished_name, s, sizeof(base_distinguished_name));

   if (!(s = ast_variable_retrieve(config, "_general", "version")) && !(s = ast_variable_retrieve(config, "_general", "protocol"))) {
      ast_log(LOG_NOTICE, "No explicit LDAP version found, using 3 as default.\n");
   } else if (sscanf(s, "%30d", &version) != 1 || version < 1 || version > 6) {
      ast_log(LOG_WARNING, "Invalid LDAP version '%s', using 3 as default.\n", s);
      version = 3;
   }

   table_configs_free();

   while ((category_name = ast_category_browse(config, category_name))) {
      int is_general = (strcasecmp(category_name, "_general") == 0);
      int is_config = (strcasecmp(category_name, "config") == 0); /*!< using the [config] context for Static RealTime */
      struct ast_variable *var = ast_variable_browse(config, category_name);

      if (var) {
         struct ldap_table_config *table_config =
            table_config_for_table_name(category_name);
         if (!table_config) {
            table_config = table_config_new(category_name);
            AST_LIST_INSERT_HEAD(&table_configs, table_config, entry);
            if (is_general)
               base_table_config = table_config;
            if (is_config)
               static_table_config = table_config;
         }
         for (; var; var = var->next) {
            if (!strcasecmp(var->name, "additionalFilter")) {
               table_config->additional_filter = ast_strdup(var->value);
            } else {
               if (!is_general || config_can_be_inherited(var->name)) {
                  ldap_table_config_add_attribute(table_config, var->name, var->value);
               }
            }
         }
      }
   }

   ast_config_destroy(config);

   return 1;
}

/*! \note ldap_lock should have been locked before calling this function. */
static int ldap_reconnect(void)
{
   int bind_result = 0;
   struct berval cred;

   if (ldapConn) {
      ast_debug(2, "Everything seems fine.\n");
      return 1;
   }

   if (ast_strlen_zero(url)) {
      ast_log(LOG_ERROR, "Not enough parameters to connect to ldap directory\n");
      return 0;
   }

   if (LDAP_SUCCESS != ldap_initialize(&ldapConn, url)) {
      ast_log(LOG_ERROR, "Failed to init ldap connection to '%s'. Check debug for more info.\n", url);
      return 0;
   }

   if (LDAP_OPT_SUCCESS != ldap_set_option(ldapConn, LDAP_OPT_PROTOCOL_VERSION, &version)) {
      ast_log(LOG_WARNING, "Unable to set LDAP protocol version to %d, falling back to default.\n", version);
   }

   if (!ast_strlen_zero(user)) {
      ast_debug(2, "bind to '%s' as user '%s'\n", url, user);
      cred.bv_val = (char *) pass;
      cred.bv_len = strlen(pass);
      bind_result = ldap_sasl_bind_s(ldapConn, user, LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL);
   } else {
      ast_debug(2, "bind %s anonymously\n", url);
      cred.bv_val = NULL;
      cred.bv_len = 0;
      bind_result = ldap_sasl_bind_s(ldapConn, NULL, LDAP_SASL_SIMPLE, &cred, NULL, NULL, NULL);
   }
   if (bind_result == LDAP_SUCCESS) {
      ast_debug(2, "Successfully connected to directory.\n");
      connect_time = time(NULL);
      return 1;
   } else {
      ast_log(LOG_WARNING, "bind failed: %s\n", ldap_err2string(bind_result));
      ldap_unbind_ext_s(ldapConn, NULL, NULL);
      ldapConn = NULL;
      return 0;
   }
}

/*! \brief Realtime Status
 *
 */
static char *realtime_ldap_status(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct ast_str *buf;
   int ctimesec = time(NULL) - connect_time;

   switch (cmd) {
   case CLI_INIT:
      e->command = "realtime show ldap status";
      e->usage =
         "Usage: realtime show ldap status\n"
         "         Shows connection information for the LDAP RealTime driver\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (!ldapConn)
      return CLI_FAILURE;

   buf = ast_str_create(512);
   if (!ast_strlen_zero(url)) {
      ast_str_append(&buf, 0, "Connected to '%s', baseDN %s", url, base_distinguished_name);
   }

   if (!ast_strlen_zero(user)) {
      ast_str_append(&buf, 0, " with username %s", user);
   }

   ast_str_append(&buf, 0, " for ");
   ast_cli_print_timestr_fromseconds(a->fd, ctimesec, ast_str_buffer(buf));
   ast_free(buf);

   return CLI_SUCCESS;
}

/*! \brief Module Information
 *
 */
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "LDAP realtime interface",
   .support_level = AST_MODULE_SUPPORT_EXTENDED,
   .load = load_module,
   .unload = unload_module,
   .reload = reload,
   .load_pri = AST_MODPRI_REALTIME_DRIVER,
   .requires = "extconfig",
);