res_config_ldap.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005, Oxymium sarl
 * Manuel Guesdon <mguesdon@oxymium.net> - LDAP RealTime Driver Author/Adaptor
 *
 * Copyright (C) 2007, Digium, Inc.
 * Russell Bryant <russell@digium.com>
 *
 * 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 <markster@digium.com>
 * \author Manuel Guesdon
 * \author Carl-Einar Thorner <cthorner@voicerd.com>
 * \author Russell Bryant <russell@digium.com>
 *
 * 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;
 
    /*! \brief 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;
}
 
/*!
 * \internal
 * \brief Escape a value for safe inclusion in an LDAP filter per RFC 4515.
 *
 * Characters that have special meaning in LDAP filters are escaped
 * to their \\HH hex representation: * ( ) \\ and NUL.
 *
 * \param value The raw value to escape
 * \param escaped Output buffer (caller-allocated ast_str)
 */
static void ldap_filter_escape_value(const char *value, struct ast_str **escaped)
{
    ast_str_reset(*escaped);
    for (; *value; value++) {
        switch (*value) {
        case '*':
            ast_str_append(escaped, 0, "\\2a");
            break;
        case '(':
            ast_str_append(escaped, 0, "\\28");
            break;
        case ')':
            ast_str_append(escaped, 0, "\\29");
            break;
        case '\\':
            ast_str_append(escaped, 0, "\\5c");
            break;
        default:
            ast_str_append(escaped, 0, "%c", *value);
            break;
        }
    }
}
 
/*! \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;
    const char *like_pos = strstr(name, " LIKE");
    struct ast_str *escaped_value;
 
    ast_debug(2, "name='%s' value='%s'\n", name, value);
 
    escaped_value = ast_str_create(256);
    if (!escaped_value) {
        return;
    }
 
    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);
        /* Note: The LIKE path preserves original wildcard behavior.
         * A more comprehensive escaping of the LIKE path is left
         * to the maintainers familiar with the query semantics.
         */
        ast_str_append(filter, 0, "(%s=%s)", name, value);
    } else {
        name = convert_attribute_name_to_ldap(table_config, name);
        ldap_filter_escape_value(value, &escaped_value);
        ast_str_append(filter, 0, "(%s=%s)", name,
            ast_str_buffer(escaped_value));
    }
 
    ast_free(escaped_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;
    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;
}
 
/*! \brief Reload 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",
);