/* ldap.c

   Routines for reading the configuration from LDAP */

/*
 * Copyright (c) 2003-2006 Ntelos, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This LDAP module was written by Brian Masney <masneyb@ntelos.net>. Its
 * development was sponsored by Ntelos, Inc. (www.ntelos.com).
 */

#include "dhcpd.h"
#include <signal.h>
#include <errno.h>

#if defined(LDAP_CONFIGURATION)

#if defined(LDAP_CASA_AUTH)
#include "ldap_casa.h"
#endif

static LDAP * ld = NULL;
static char *ldap_server = NULL, 
            *ldap_username = NULL, 
            *ldap_password = NULL,
            *ldap_base_dn = NULL,
            *ldap_dhcp_server_cn = NULL,
            *ldap_debug_file = NULL;
static int ldap_port = LDAP_PORT,
           ldap_method = LDAP_METHOD_DYNAMIC,
           ldap_referrals = -1,
           ldap_debug_fd = -1;
#if defined (LDAP_USE_SSL)
static int ldap_use_ssl = -1,        /* try TLS if possible */
           ldap_tls_reqcert = -1,
           ldap_tls_crlcheck = -1;
static char *ldap_tls_ca_file = NULL,
            *ldap_tls_ca_dir = NULL,
            *ldap_tls_cert = NULL,
            *ldap_tls_key = NULL,
            *ldap_tls_ciphers = NULL,
            *ldap_tls_randfile = NULL;
#endif
static struct ldap_config_stack *ldap_stack = NULL;

typedef struct ldap_dn_node {
    struct ldap_dn_node *next;
    size_t refs;
    char *dn;
} ldap_dn_node;

static ldap_dn_node *ldap_service_dn_head = NULL;
static ldap_dn_node *ldap_service_dn_tail = NULL;


static char *
x_strncat(char *dst, const char *src, size_t dst_size)
{
  size_t len = strlen(dst);
  return strncat(dst, src, dst_size > len ? dst_size - len - 1: 0);
}

static void
ldap_parse_class (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) == NULL ||
      tempbv[0] == NULL)
    {
      if (tempbv != NULL)
        ldap_value_free_len (tempbv);

      return;
    }

  x_strncat (cfile->inbuf, "class \"", LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, "\" {\n", LDAP_BUFFER_SIZE);

  item->close_brace = 1;
  ldap_value_free_len (tempbv);
}


static void
ldap_parse_subclass (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv, **classdata;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) == NULL ||
      tempbv[0] == NULL)
    {
      if (tempbv != NULL)
        ldap_value_free_len (tempbv);

      return;
    }

  if ((classdata = ldap_get_values_len (ld, item->ldent, 
                                  "dhcpClassData")) == NULL || 
      classdata[0] == NULL)
    {
      if (classdata != NULL)
        ldap_value_free_len (classdata);
      ldap_value_free_len (tempbv);

      return;
    }

  x_strncat (cfile->inbuf, "subclass ", LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, classdata[0]->bv_val, LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, " ", LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, " {\n", LDAP_BUFFER_SIZE);

  item->close_brace = 1;
  ldap_value_free_len (tempbv);
  ldap_value_free_len (classdata);
}


static void
ldap_parse_host (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv, **hwaddr;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) == NULL ||
      tempbv[0] == NULL)
    {
      if (tempbv != NULL)
        ldap_value_free_len (tempbv);

      return;
    }

  hwaddr = ldap_get_values_len (ld, item->ldent, "dhcpHWAddress");

  x_strncat (cfile->inbuf, "host ", LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);

  if (hwaddr != NULL && hwaddr[0] != NULL)
    {
      x_strncat (cfile->inbuf, " {\nhardware ", LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, hwaddr[0]->bv_val, LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (hwaddr);
    }

  item->close_brace = 1;
  ldap_value_free_len (tempbv);
}


static void
ldap_parse_shared_network (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) == NULL ||
      tempbv[0] == NULL)
    {
      if (tempbv != NULL)
        ldap_value_free_len (tempbv);

      return;
    }

  x_strncat (cfile->inbuf, "shared-network \"", LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, "\" {\n", LDAP_BUFFER_SIZE);

  item->close_brace = 1;
  ldap_value_free_len (tempbv);
}


static void
parse_netmask (int netmask, char *netmaskbuf)
{
  unsigned long nm;
  int i;

  nm = 0;
  for (i=1; i <= netmask; i++)
    {
      nm |= 1 << (32 - i);
    }

  sprintf (netmaskbuf, "%d.%d.%d.%d", (int) (nm >> 24) & 0xff, 
                                      (int) (nm >> 16) & 0xff, 
                                      (int) (nm >> 8) & 0xff, 
                                      (int) nm & 0xff);
}


static void
ldap_parse_subnet (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv, **netmaskstr;
  char netmaskbuf[sizeof("255.255.255.255")];
  int i;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) == NULL ||
      tempbv[0] == NULL)
    {
      if (tempbv != NULL)
        ldap_value_free_len (tempbv);

      return;
    }

  if ((netmaskstr = ldap_get_values_len (ld, item->ldent, 
                                     "dhcpNetmask")) == NULL || 
      netmaskstr[0] == NULL)
    {
      if (netmaskstr != NULL)
        ldap_value_free_len (netmaskstr);
      ldap_value_free_len (tempbv);

      return;
    }

  x_strncat (cfile->inbuf, "subnet ", LDAP_BUFFER_SIZE);
  x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);

  x_strncat (cfile->inbuf, " netmask ", LDAP_BUFFER_SIZE);
  parse_netmask (strtol (netmaskstr[0]->bv_val, NULL, 10), netmaskbuf);
  x_strncat (cfile->inbuf, netmaskbuf, LDAP_BUFFER_SIZE);

  x_strncat (cfile->inbuf, " {\n", LDAP_BUFFER_SIZE);

  ldap_value_free_len (tempbv);
  ldap_value_free_len (netmaskstr);

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpRange")) != NULL)
    {
      for (i=0; tempbv[i] != NULL; i++)
        {
          x_strncat (cfile->inbuf, "range", LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, " ", LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, tempbv[i]->bv_val, LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
        }
    }

  item->close_brace = 1;
}


static void
ldap_parse_pool (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv;
  int i;

  x_strncat (cfile->inbuf, "pool {\n", LDAP_BUFFER_SIZE);

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpRange")) != NULL)
    {
      x_strncat (cfile->inbuf, "range", LDAP_BUFFER_SIZE);
      for (i=0; tempbv[i] != NULL; i++)
        {
          x_strncat (cfile->inbuf, " ", LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, tempbv[i]->bv_val, LDAP_BUFFER_SIZE);
        }
      x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (tempbv);
    }

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpPermitList")) != NULL)
    {
      for (i=0; tempbv[i] != NULL; i++)
        {
          x_strncat (cfile->inbuf, tempbv[i]->bv_val, LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
        }
      ldap_value_free_len (tempbv);
    }

  item->close_brace = 1;
}


static void
ldap_parse_group (struct ldap_config_stack *item, struct parse *cfile)
{
  x_strncat (cfile->inbuf, "group {\n", LDAP_BUFFER_SIZE);
  item->close_brace = 1;
}


static void
ldap_parse_key (struct ldap_config_stack *item, struct parse *cfile)
{
  struct berval **tempbv;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) != NULL)
    {
      x_strncat (cfile->inbuf, "key ", LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, " {\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (tempbv);
    }

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpKeyAlgorithm")) != NULL)
    {
      x_strncat (cfile->inbuf, "algorithm ", LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (tempbv);
    }

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpKeySecret")) != NULL)
    {
      x_strncat (cfile->inbuf, "secret ", LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (tempbv);
    }

  item->close_brace = 1;
}


static void
ldap_parse_zone (struct ldap_config_stack *item, struct parse *cfile)
{
  char *cnFindStart, *cnFindEnd;
  struct berval **tempbv;
  char *keyCn;
  size_t len;

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "cn")) != NULL)
    {
      x_strncat (cfile->inbuf, "zone ", LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, " {\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (tempbv);
    }

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpDnsZoneServer")) != NULL)
    {
      x_strncat (cfile->inbuf, "primary ", LDAP_BUFFER_SIZE);
      x_strncat (cfile->inbuf, tempbv[0]->bv_val, LDAP_BUFFER_SIZE);

      x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);
      ldap_value_free_len (tempbv);
    }

  if ((tempbv = ldap_get_values_len (ld, item->ldent, "dhcpKeyDN")) != NULL)
    {
      cnFindStart = strchr(tempbv[0]->bv_val,'=');
      if (cnFindStart != NULL)
        cnFindEnd = strchr(++cnFindStart,',');
      else
        cnFindEnd = NULL;

      if (cnFindEnd != NULL && cnFindEnd > cnFindStart)
        {
          len = cnFindEnd - cnFindStart;
          keyCn = dmalloc (len + 1, MDL);
        }
      else
        {
          len = 0;
          keyCn = NULL;
        }

      if (keyCn != NULL)
        {
          strncpy (keyCn, cnFindStart, len);
          keyCn[len] = '\0';

          x_strncat (cfile->inbuf, "key ", LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, keyCn, LDAP_BUFFER_SIZE);
          x_strncat (cfile->inbuf, ";\n", LDAP_BUFFER_SIZE);

          dfree (keyCn, MDL);
        }

      ldap_value_free_len (tempbv);
     }

  item->close_brace = 1;
}


static void
add_to_config_stack (LDAPMessage * res, LDAPMessage * ent)
{
  struct ldap_config_stack *ns;

  ns = dmalloc (sizeof (*ns), MDL);
  ns->res = res;
  ns->ldent = ent;
  ns->close_brace = 0;
  ns->processed = 0;
  ns->next = ldap_stack;
  ldap_stack = ns;
}


static void
ldap_stop()
{
  struct sigaction old, new;

  if (ld == NULL)
    return;

  /*
   ** ldap_unbind after a LDAP_SERVER_DOWN result
   ** causes a SIGPIPE and dhcpd gets terminated,
   ** since it doesn't handle it...
   */

  new.sa_flags   = 0;
  new.sa_handler = SIG_IGN;
  sigemptyset (&new.sa_mask);
  sigaction (SIGPIPE, &new, &old);

  ldap_unbind_ext_s (ld, NULL, NULL);
  ld = NULL;

  sigaction (SIGPIPE, &old, &new);
}


static char *
_do_lookup_dhcp_string_option (struct option_state *options, int option_name)
{
  struct option_cache *oc;
  struct data_string db;
  char *ret;

  memset (&db, 0, sizeof (db));
  oc = lookup_option (&server_universe, options, option_name);
  if (oc &&
      evaluate_option_cache (&db, (struct packet*) NULL,
                             (struct lease *) NULL,
                             (struct client_state *) NULL, options,
                             (struct option_state *) NULL,
                             &global_scope, oc, MDL) &&
      db.data != NULL && *db.data != '\0')

    {
      ret = dmalloc (db.len + 1, MDL);
      if (ret == NULL)
        log_fatal ("no memory for ldap option %d value", option_name);

      memcpy (ret, db.data, db.len);
      ret[db.len] = 0;
      data_string_forget (&db, MDL);
    }
  else
    ret = NULL;

  return (ret);
}


static int
_do_lookup_dhcp_int_option (struct option_state *options, int option_name)
{
  struct option_cache *oc;
  struct data_string db;
  int ret;

  memset (&db, 0, sizeof (db));
  oc = lookup_option (&server_universe, options, option_name);
  if (oc &&
      evaluate_option_cache (&db, (struct packet*) NULL,
                             (struct lease *) NULL,
                             (struct client_state *) NULL, options,
                             (struct option_state *) NULL,
                             &global_scope, oc, MDL) &&
      db.data != NULL && *db.data != '\0')
    {
      ret = strtol ((const char *) db.data, NULL, 10);
      data_string_forget (&db, MDL);
    }
  else
    ret = 0;

  return (ret);
}


static int
_do_lookup_dhcp_enum_option (struct option_state *options, int option_name)
{
  struct option_cache *oc;
  struct data_string db;
  int ret = -1;

  memset (&db, 0, sizeof (db));
  oc = lookup_option (&server_universe, options, option_name);
  if (oc &&
      evaluate_option_cache (&db, (struct packet*) NULL,
                             (struct lease *) NULL,
                             (struct client_state *) NULL, options,
                             (struct option_state *) NULL,
                             &global_scope, oc, MDL) &&
      db.data != NULL && *db.data != '\0')
    {
      if (db.len == 1) 
        ret = db.data [0];
      else
        log_fatal ("invalid option name %d", option_name);

      data_string_forget (&db, MDL);
    }
  else
    ret = 0;

  return (ret);
}

int
ldap_rebind_cb (LDAP *ld, LDAP_CONST char *url, ber_tag_t request, ber_int_t msgid, void *parms)
{
  int ret;
  LDAPURLDesc *ldapurl = NULL;
  char *who = NULL;
  struct berval creds;

  log_info("LDAP rebind to '%s'", url);
  if ((ret = ldap_url_parse(url, &ldapurl)) != LDAP_SUCCESS)
    {
      log_error ("Error: Can not parse ldap rebind url '%s': %s",
                 url, ldap_err2string(ret));
      return ret;
    }


#if defined (LDAP_USE_SSL)
  if (strcasecmp(ldapurl->lud_scheme, "ldaps") == 0)
    {
      int opt = LDAP_OPT_X_TLS_HARD;
      if ((ret = ldap_set_option (ld, LDAP_OPT_X_TLS, &opt)) != LDAP_SUCCESS)
        {
          log_error ("Error: Cannot init LDAPS session to %s:%d: %s",
                    ldapurl->lud_host, ldapurl->lud_port, ldap_err2string (ret));
          return ret;
        }
      else
        {
          log_info ("LDAPS session successfully enabled to %s", ldap_server);
        }
    }
  else
  if (strcasecmp(ldapurl->lud_scheme, "ldap") == 0 &&
      ldap_use_ssl != LDAP_SSL_OFF)
    {
      if ((ret = ldap_start_tls_s (ld, NULL, NULL)) != LDAP_SUCCESS)
        {
          log_error ("Error: Cannot start TLS session to %s:%d: %s",
                     ldapurl->lud_host, ldapurl->lud_port, ldap_err2string (ret));
          return ret;
        }
      else
        {
          log_info ("TLS session successfully started to %s:%d",
                    ldapurl->lud_host, ldapurl->lud_port);
        }
    }
#endif


  if (ldap_username != NULL || *ldap_username != '\0')
    {
      who = ldap_username;
      creds.bv_val = strdup(ldap_password);
      creds.bv_len = strlen(ldap_password);
    }

  if ((ret = ldap_sasl_bind_s (ld, who, LDAP_SASL_SIMPLE, &creds,
                               NULL, NULL, NULL)) != LDAP_SUCCESS)
    {
      log_error ("Error: Cannot login into ldap server %s:%d: %s",
                 ldapurl->lud_host, ldapurl->lud_port, ldap_err2string (ret));
    }
  return ret;
}

static void
ldap_start (void)
{
  struct option_state *options;
  int ret, version;
  char *uri = NULL;
  struct berval creds;

  if (ld != NULL)
    return;

  if (ldap_server == NULL)
    {
      options = NULL;
      option_state_allocate (&options, MDL);

      execute_statements_in_scope ((struct binding_value **) NULL,
                 (struct packet *) NULL, (struct lease *) NULL,
                 (struct client_state *) NULL, (struct option_state *) NULL,
                 options, &global_scope, root_group, (struct group *) NULL);

      ldap_server = _do_lookup_dhcp_string_option (options, SV_LDAP_SERVER);
      ldap_dhcp_server_cn = _do_lookup_dhcp_string_option (options,
                                                      SV_LDAP_DHCP_SERVER_CN);
      ldap_port = _do_lookup_dhcp_int_option (options, SV_LDAP_PORT);
      ldap_base_dn = _do_lookup_dhcp_string_option (options, SV_LDAP_BASE_DN);
      ldap_method = _do_lookup_dhcp_enum_option (options, SV_LDAP_METHOD);
      ldap_debug_file = _do_lookup_dhcp_string_option (options,
                                                       SV_LDAP_DEBUG_FILE);
      ldap_referrals = _do_lookup_dhcp_enum_option (options, SV_LDAP_REFERRALS);

#if defined (LDAP_USE_SSL)
      ldap_use_ssl = _do_lookup_dhcp_enum_option (options, SV_LDAP_SSL);
      if( ldap_use_ssl != LDAP_SSL_OFF)
        {
          ldap_tls_reqcert = _do_lookup_dhcp_enum_option (options, SV_LDAP_TLS_REQCERT);
          ldap_tls_ca_file = _do_lookup_dhcp_string_option (options, SV_LDAP_TLS_CA_FILE);
          ldap_tls_ca_dir = _do_lookup_dhcp_string_option (options, SV_LDAP_TLS_CA_DIR);
          ldap_tls_cert = _do_lookup_dhcp_string_option (options, SV_LDAP_TLS_CERT);
          ldap_tls_key = _do_lookup_dhcp_string_option (options, SV_LDAP_TLS_KEY);
          ldap_tls_crlcheck = _do_lookup_dhcp_enum_option (options, SV_LDAP_TLS_CRLCHECK);
          ldap_tls_ciphers = _do_lookup_dhcp_string_option (options, SV_LDAP_TLS_CIPHERS);
          ldap_tls_randfile = _do_lookup_dhcp_string_option (options, SV_LDAP_TLS_RANDFILE);
        }
#endif

#if defined (LDAP_CASA_AUTH)
      if (!load_uname_pwd_from_miCASA(&ldap_username,&ldap_password))
        {
#if defined (DEBUG_LDAP)
          log_info ("Authentication credential taken from file");
#endif
#endif

      ldap_username = _do_lookup_dhcp_string_option (options, SV_LDAP_USERNAME);
      ldap_password = _do_lookup_dhcp_string_option (options, SV_LDAP_PASSWORD);

#if defined (LDAP_CASA_AUTH)
      }
#endif

      option_state_dereference (&options, MDL);
    }

  if (ldap_server == NULL || ldap_base_dn == NULL)
    {
      log_info ("Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file");
      ldap_method = LDAP_METHOD_STATIC;
      return;
    }

  if (ldap_debug_file != NULL && ldap_debug_fd == -1)
    {
      if ((ldap_debug_fd = open (ldap_debug_file, O_CREAT | O_TRUNC | O_WRONLY,
                                 S_IRUSR | S_IWUSR)) < 0)
        log_error ("Error opening debug LDAP log file %s: %s", ldap_debug_file,
                   strerror (errno));
    }

#if defined (DEBUG_LDAP)
  log_info ("Connecting to LDAP server %s:%d", ldap_server, ldap_port);
#endif

#if defined (LDAP_USE_SSL)
  if (ldap_use_ssl == -1)
    {
      /*
      ** There was no "ldap-ssl" option in dhcpd.conf (also not "off").
      ** Let's try, if we can use an anonymous TLS session without to
      ** verify the server certificate -- if not continue without TLS.
      */
      int opt = LDAP_OPT_X_TLS_ALLOW;
      if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_REQUIRE_CERT,
                                  &opt)) != LDAP_SUCCESS)
        {
          log_error ("Warning: Cannot set LDAP TLS require cert option to 'allow': %s",
                     ldap_err2string (ret));
        }
    }

  if (ldap_use_ssl != LDAP_SSL_OFF)
    {
      if (ldap_tls_reqcert != -1)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_REQUIRE_CERT,
                                      &ldap_tls_reqcert)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS require cert option: %s",
                         ldap_err2string (ret));
            }
        }

      if( ldap_tls_ca_file != NULL)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_CACERTFILE,
                                      ldap_tls_ca_file)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS CA certificate file %s: %s",
                         ldap_tls_ca_file, ldap_err2string (ret));
            }
        }
      if( ldap_tls_ca_dir != NULL)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_CACERTDIR,
                                      ldap_tls_ca_dir)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS CA certificate dir %s: %s",
                         ldap_tls_ca_dir, ldap_err2string (ret));
            }
        }
      if( ldap_tls_cert != NULL)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_CERTFILE,
                                      ldap_tls_cert)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS client certificate file %s: %s",
                         ldap_tls_cert, ldap_err2string (ret));
            }
        }
      if( ldap_tls_key != NULL)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_KEYFILE,
                                      ldap_tls_key)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS certificate key file %s: %s",
                         ldap_tls_key, ldap_err2string (ret));
            }
        }
      if( ldap_tls_crlcheck != -1)
        {
          int opt = ldap_tls_crlcheck;
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_CRLCHECK,
                                      &opt)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS crl check option: %s",
                         ldap_err2string (ret));
            }
        }
      if( ldap_tls_ciphers != NULL)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_CIPHER_SUITE,
                                      ldap_tls_ciphers)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS cipher suite %s: %s",
                         ldap_tls_ciphers, ldap_err2string (ret));
            }
        }
      if( ldap_tls_randfile != NULL)
        {
          if ((ret = ldap_set_option (NULL, LDAP_OPT_X_TLS_RANDOM_FILE,
                                      ldap_tls_randfile)) != LDAP_SUCCESS)
            {
              log_error ("Cannot set LDAP TLS random file %s: %s",
                         ldap_tls_randfile, ldap_err2string (ret));
            }
        }
    }
#endif

  /* enough for 'ldap://+ + hostname + ':' + port number */
  uri = malloc(strlen(ldap_server) + 16);
  if (uri == NULL)
    {
      log_error ("Cannot build ldap init URI %s:%d", ldap_server, ldap_port);
      return;
    }

  sprintf(uri, "ldap://%s:%d", ldap_server, ldap_port);
  ldap_initialize(&ld, uri);

  if (ld == NULL)
    {
      log_error ("Cannot init ldap session to %s:%d", ldap_server, ldap_port);
      return;
    }

  free(uri);

  version = LDAP_VERSION3;
  if ((ret = ldap_set_option (ld, LDAP_OPT_PROTOCOL_VERSION, &version)) != LDAP_OPT_SUCCESS)
    {
      log_error ("Cannot set LDAP version to %d: %s", version,
                 ldap_err2string (ret));
    }

  if (ldap_referrals != -1)
    {
      if ((ret = ldap_set_option (ld, LDAP_OPT_REFERRALS, ldap_referrals ?
                                  LDAP_OPT_ON : LDAP_OPT_OFF)) != LDAP_OPT_SUCCESS)
        {
          log_error ("Cannot %s LDAP referrals option: %s",
                     (ldap_referrals ? "enable" : "disable"),
                     ldap_err2string (ret));
        }
    }

  if ((ret = ldap_set_rebind_proc(ld, ldap_rebind_cb, NULL)) != LDAP_SUCCESS)
    {
      log_error ("Warning: Cannot set ldap rebind procedure: %s",
                 ldap_err2string (ret));
    }

#if defined (LDAP_USE_SSL)
  if (ldap_use_ssl == LDAP_SSL_LDAPS ||
     (ldap_use_ssl == LDAP_SSL_ON && ldap_port == LDAPS_PORT))
    {
      int opt = LDAP_OPT_X_TLS_HARD;
      if ((ret = ldap_set_option (ld, LDAP_OPT_X_TLS, &opt)) != LDAP_SUCCESS)
        {
          log_error ("Error: Cannot init LDAPS session to %s:%d: %s",
                    ldap_server, ldap_port, ldap_err2string (ret));
          ldap_stop();
          return;
        }
      else
        {
          log_info ("LDAPS session successfully enabled to %s:%d",
                    ldap_server, ldap_port);
        }
    }
  else if (ldap_use_ssl != LDAP_SSL_OFF)
    {
      if ((ret = ldap_start_tls_s (ld, NULL, NULL)) != LDAP_SUCCESS)
        {
          log_error ("Error: Cannot start TLS session to %s:%d: %s",
                     ldap_server, ldap_port, ldap_err2string (ret));
          ldap_stop();
          return;
        }
      else
        {
          log_info ("TLS session successfully started to %s:%d",
                    ldap_server, ldap_port);
        }
    }
#endif

  if (ldap_username != NULL && *ldap_username != '\0')
    {
      creds.bv_val = strdup(ldap_password);
      creds.bv_len = strlen(ldap_password);

      if ((ret = ldap_sasl_bind_s (ld, ldap_username, LDAP_SASL_SIMPLE,
                                   &creds, NULL, NULL, NULL)) != LDAP_SUCCESS)
        {
          log_error ("Error: Cannot login into ldap server %s:%d: %s",
                     ldap_server, ldap_port, ldap_err2string (ret));
          ldap_stop();
          return;
        }
    }

#if defined (DEBUG_LDAP)
  log_info ("Successfully logged into LDAP server %s", ldap_server);
#endif
}


static void
parse_external_dns (LDAPMessage * ent)
{
  char *search[] = {"dhcpOptionsDN", "dhcpSharedNetworkDN", "dhcpSubnetDN",
                    "dhcpGroupDN", "dhcpHostDN", "dhcpClassesDN",
                    "dhcpPoolDN", NULL};
  LDAPMessage * newres, * newent;
  struct berval **tempbv;
  int i, j, ret;
#if defined (DEBUG_LDAP)
  char *dn;

  dn = ldap_get_dn (ld, ent);
  if (dn != NULL)
    {
      log_info ("Parsing external DNs for '%s'", dn);
      ldap_memfree (dn);
    }
#endif

  if (ld == NULL)
    ldap_start ();
  if (ld == NULL)
    return;

  for (i=0; search[i] != NULL; i++)
    {
      if ((tempbv = ldap_get_values_len (ld, ent, search[i])) == NULL)
        continue;

      for (j=0; tempbv[j] != NULL; j++)
        {
          if (*tempbv[j]->bv_val == '\0')
            continue;

          if ((ret = ldap_search_ext_s(ld, tempbv[j]->bv_val, LDAP_SCOPE_BASE,
                                       "objectClass=*", NULL, 0, NULL,
                                       NULL, NULL, 0, &newres)) != LDAP_SUCCESS)
            {
              ldap_value_free_len (tempbv);
              ldap_stop();
              return;
            }
    
#if defined (DEBUG_LDAP)
          log_info ("Adding contents of subtree '%s' to config stack from '%s' reference", tempbv[j], search[i]);
#endif
          for (newent = ldap_first_entry (ld, newres);
               newent != NULL;
               newent = ldap_next_entry (ld, newent))
            {
#if defined (DEBUG_LDAP)
              dn = ldap_get_dn (ld, newent);
              if (dn != NULL)
                {
                  log_info ("Adding LDAP result set starting with '%s' to config stack", dn);
                  ldap_memfree (dn);
                }
#endif

              add_to_config_stack (newres, newent);
              /* don't free newres here */
            }
        }

      ldap_value_free_len (tempbv);
    }
}


static void
free_stack_entry (struct ldap_config_stack *item)
{
  struct ldap_config_stack *look_ahead_pointer = item;
  int may_free_msg = 1;

  while (look_ahead_pointer->next != NULL)
    {
      look_ahead_pointer = look_ahead_pointer->next;
      if (look_ahead_pointer->res == item->res)
        {
          may_free_msg = 0;
          break;
        }
    }

  if (may_free_msg) 
    ldap_msgfree (item->res);

  dfree (item, MDL);
}


static void
next_ldap_entry (struct parse *cfile)
{
  struct ldap_config_stack *temp_stack;

  if (ldap_stack != NULL && ldap_stack->close_brace)
    {
      x_strncat (cfile->inbuf, "}\n", LDAP_BUFFER_SIZE);
      ldap_stack->close_brace = 0;
    }

  while (ldap_stack != NULL && 
         (ldap_stack->ldent == NULL ||
          (ldap_stack->ldent = ldap_next_entry (ld, ldap_stack->ldent)) == NULL))
    {
      if (ldap_stack->close_brace)
        {
          x_strncat (cfile->inbuf, "}\n", LDAP_BUFFER_SIZE);
          ldap_stack->close_brace = 0;
        }

      temp_stack = ldap_stack;
      ldap_stack = ldap_stack->next;
      free_stack_entry (temp_stack);
    }

  if (ldap_stack != NULL && ldap_stack->close_brace)
    {
      x_strncat (cfile->inbuf, "}\n", LDAP_BUFFER_SIZE);
      ldap_stack->close_brace = 0;
    }
}


static char
check_statement_end (const char *statement)
{
  char *ptr;

  if (statement == NULL || *statement == '\0')
    return ('\0');

  /*
  ** check if it ends with "}", e.g.:
  **   "zone my.domain. { ... }"
  ** optionally followed by spaces
  */
  ptr = strrchr (statement, '}');
  if (ptr != NULL)
    {
      /* skip following white-spaces */
      for (++ptr; isspace ((int)*ptr); ptr++);

      /* check if we reached the end */
      if (*ptr == '\0')
        return ('}'); /* yes, block end */
      else
        return (*ptr);
    }

  /*
  ** this should not happen, but...
  ** check if it ends with ";", e.g.:
  **   "authoritative;"
  ** optionally followed by spaces
  */
  ptr = strrchr (statement, ';');
  if (ptr != NULL)
    {
      /* skip following white-spaces */
      for (++ptr; isspace ((int)*ptr); ptr++);

      /* check if we reached the end */
      if (*ptr == '\0')
        return (';'); /* ends with a ; */
      else
        return (*ptr);
    }

  return ('\0');
}


static isc_result_t
ldap_parse_entry_options (LDAPMessage *ent, char *buffer, size_t size,
                          int *lease_limit)
{
  struct berval **tempbv;
  int i;

  if (ent == NULL || buffer == NULL || size == 0)
    return (ISC_R_FAILURE);

  if ((tempbv = ldap_get_values_len (ld, ent, "dhcpStatements")) != NULL)
    {
      for (i=0; tempbv[i] != NULL; i++)
        {
          if (lease_limit != NULL &&
              strncasecmp ("lease limit ", tempbv[i]->bv_val, 12) == 0)
            {
              *lease_limit = (int) strtol ((tempbv[i]->bv_val) + 12, NULL, 10);
              continue;
            }

          x_strncat (buffer, tempbv[i]->bv_val, size);

          switch((int) check_statement_end (tempbv[i]->bv_val))
            {
              case '}':
              case ';':
                x_strncat (buffer, "\n", size);
                break;
              default:
                x_strncat (buffer, ";\n", size);
                break;
            }
        }
      ldap_value_free_len (tempbv);
    }

  if ((tempbv = ldap_get_values_len (ld, ent, "dhcpOption")) != NULL)
    {
      for (i=0; tempbv[i] != NULL; i++)
        {
          x_strncat (buffer, "option ", size);
          x_strncat (buffer, tempbv[i]->bv_val, size);
          switch ((int) check_statement_end (tempbv[i]->bv_val))
            {
              case ';':
                x_strncat (buffer, "\n", size);
                break;
              default:
                x_strncat (buffer, ";\n", size);
                break;
            }
        }
      ldap_value_free_len (tempbv);
    }

  return (ISC_R_SUCCESS);
}


static void
ldap_generate_config_string (struct parse *cfile)
{
  struct berval **objectClass;
  char *dn;
  struct ldap_config_stack *entry;
  LDAPMessage * ent, * res;
  int i, ignore, found;
  int ret;

  if (ld == NULL)
    ldap_start ();
  if (ld == NULL)
    return;

  entry = ldap_stack;
  if ((objectClass = ldap_get_values_len (ld, entry->ldent, 
                                      "objectClass")) == NULL)
    return;
    
  ignore = 0;
  found = 1;
  for (i=0; objectClass[i] != NULL; i++)
    {
      if (strcasecmp (objectClass[i]->bv_val, "dhcpSharedNetwork") == 0)
        ldap_parse_shared_network (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpClass") == 0)
        ldap_parse_class (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpSubnet") == 0)
        ldap_parse_subnet (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpPool") == 0)
        ldap_parse_pool (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpGroup") == 0)
        ldap_parse_group (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpTSigKey") == 0)
        ldap_parse_key (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpDnsZone") == 0)
        ldap_parse_zone (entry, cfile);
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpHost") == 0)
        {
          if (ldap_method == LDAP_METHOD_STATIC)
            ldap_parse_host (entry, cfile);
          else
            {
              ignore = 1;
              break;
            }
        }
      else if (strcasecmp (objectClass[i]->bv_val, "dhcpSubClass") == 0)
        {
          if (ldap_method == LDAP_METHOD_STATIC)
            ldap_parse_subclass (entry, cfile);
          else
            {
              ignore = 1;
              break;
            }
        }
      else
        found = 0;

      if (found && cfile->inbuf[0] == '\0')
        {
          ignore = 1;
          break;
        }
    }

  ldap_value_free_len (objectClass);

  if (ignore)
    {
      next_ldap_entry (cfile);
      return;
    }

  ldap_parse_entry_options(entry->ldent, cfile->inbuf,
                           LDAP_BUFFER_SIZE-1, NULL);

  dn = ldap_get_dn (ld, entry->ldent);

#if defined(DEBUG_LDAP)
  if (dn != NULL)
    log_info ("Found LDAP entry '%s'", dn);
#endif

  if (dn == NULL ||
      (ret = ldap_search_ext_s (ld, dn, LDAP_SCOPE_ONELEVEL,
                                "objectClass=*", NULL, 0, NULL, NULL,
                                NULL, 0, &res)) != LDAP_SUCCESS)
    {
      if (dn)
        ldap_memfree (dn);

      ldap_stop();
      return;
    }

  ldap_memfree (dn);

  if ((ent = ldap_first_entry (ld, res)) != NULL)
    {
      add_to_config_stack (res, ent);
      parse_external_dns (entry->ldent);
    }
  else
    {
      ldap_msgfree (res);
      parse_external_dns (entry->ldent);
      next_ldap_entry (cfile);
    }
}


static void
ldap_close_debug_fd()
{
  if (ldap_debug_fd != -1)
    {
      close (ldap_debug_fd);
      ldap_debug_fd = -1;
    }
}


static void
ldap_write_debug (const void *buff, size_t size)
{
  if (ldap_debug_fd != -1)
    {
      if (write (ldap_debug_fd, buff, size) < 0)
        {
          log_error ("Error writing to LDAP debug file %s: %s."
                     " Disabling log file.", ldap_debug_file,
                     strerror (errno));
          ldap_close_debug_fd();
        }
    }
}

static int
ldap_read_function (struct parse *cfile)
{
  cfile->inbuf[0] = '\0';
  cfile->buflen = 0;
 
  while (ldap_stack != NULL && *cfile->inbuf == '\0')
    ldap_generate_config_string (cfile);

  if (ldap_stack == NULL && *cfile->inbuf == '\0')
    return (EOF);

  cfile->bufix = 1;
  cfile->buflen = strlen (cfile->inbuf) - 1;
  if (cfile->buflen > 0)
    ldap_write_debug (cfile->inbuf, cfile->buflen);

#if defined (DEBUG_LDAP)
  log_info ("Sending config line '%s'", cfile->inbuf);
#endif

  return (cfile->inbuf[0]);
}


static char *
ldap_get_host_name (LDAPMessage * ent)
{
  struct berval **name;
  char *ret;

  ret = NULL;
  if ((name = ldap_get_values_len (ld, ent, "cn")) == NULL || name[0] == NULL)
    {
      if (name != NULL)
        ldap_value_free_len (name);

#if defined (DEBUG_LDAP)
      ret = ldap_get_dn (ld, ent);
      if (ret != NULL)
        {
          log_info ("Cannot get cn attribute for LDAP entry %s", ret);
          ldap_memfree(ret);
        }
#endif
      return (NULL);
    }

  ret = dmalloc (strlen (name[0]->bv_val) + 1, MDL);
  strcpy (ret, name[0]->bv_val);
  ldap_value_free_len (name);

  return (ret);
}


static int
getfqhostname(char *fqhost, size_t size)
{
#if defined(MAXHOSTNAMELEN)
  char   hname[MAXHOSTNAMELEN];
#else
  char   hname[65];
#endif
  struct hostent *hp;

  if(NULL == fqhost || 1 >= size)
    return -1;

  memset(hname, 0, sizeof(hname));
  if( gethostname(hname, sizeof(hname)-1))
    return -1;

  if(NULL == (hp = gethostbyname(hname)))
    return -1;

  strncpy(fqhost, hp->h_name, size-1);
  fqhost[size-1] = '\0';
  return 0;
}


isc_result_t
ldap_read_config (void)
{
  LDAPMessage * ldres, * hostres, * ent, * hostent;
  char hfilter[1024], sfilter[1024], fqdn[257];
  char *buffer, *hostdn;
  ldap_dn_node *curr = NULL;
  struct parse *cfile;
  struct utsname unme;
  isc_result_t res;
  size_t length;
  int ret, cnt;
  struct berval **tempbv = NULL;

  if (ld == NULL)
    ldap_start ();
  if (ld == NULL)
    return (ldap_server == NULL ? ISC_R_SUCCESS : ISC_R_FAILURE);
 
  buffer = dmalloc (LDAP_BUFFER_SIZE+1, MDL);
  if (buffer == NULL)
    return (ISC_R_FAILURE);

  cfile = (struct parse *) NULL;
  res = new_parse (&cfile, -1, buffer, LDAP_BUFFER_SIZE, "LDAP", 0);
  if (res != ISC_R_SUCCESS)
    return (res);
 
  uname (&unme);
  if (ldap_dhcp_server_cn != NULL)
    {
     snprintf (hfilter, sizeof (hfilter),
                "(&(objectClass=dhcpServer)(cn=%s))", ldap_dhcp_server_cn);
    }
  else
  {
  if(0 == getfqhostname(fqdn, sizeof(fqdn)))
    {
      snprintf (hfilter, sizeof (hfilter),
                "(&(objectClass=dhcpServer)(|(cn=%s)(cn=%s)))", 
                unme.nodename, fqdn);
    }
  else
    {
      snprintf (hfilter, sizeof (hfilter),
                "(&(objectClass=dhcpServer)(cn=%s))", unme.nodename);
    }

  }
  hostres = NULL;
  if ((ret = ldap_search_ext_s (ld, ldap_base_dn, LDAP_SCOPE_SUBTREE,
                                hfilter, NULL, 0, NULL, NULL, NULL, 0,
                                &hostres)) != LDAP_SUCCESS)
    {
      log_error ("Cannot find host LDAP entry %s %s",
		 ((ldap_dhcp_server_cn == NULL)?(unme.nodename):(ldap_dhcp_server_cn)), hfilter);
      if(NULL != hostres)
        ldap_msgfree (hostres);
      ldap_stop();
      return (ISC_R_FAILURE);
    }

  if ((hostent = ldap_first_entry (ld, hostres)) == NULL)
    {
      log_error ("Error: Cannot find LDAP entry matching %s", hfilter);
      ldap_msgfree (hostres);
      ldap_stop();
      return (ISC_R_FAILURE);
    }

  hostdn = ldap_get_dn (ld, hostent);
#if defined(DEBUG_LDAP)
  if (hostdn != NULL)
    log_info ("Found dhcpServer LDAP entry '%s'", hostdn);
#endif

  if (hostdn == NULL ||
      (tempbv = ldap_get_values_len (ld, hostent, "dhcpServiceDN")) == NULL ||
      tempbv[0] == NULL)
    {
      log_error ("Error: Cannot find LDAP entry matching %s", hfilter);

      if (tempbv != NULL)
        ldap_value_free_len (tempbv);

      if (hostdn)
        ldap_memfree (hostdn);
      ldap_msgfree (hostres);
      ldap_stop();
      return (ISC_R_FAILURE);
    }

#if defined(DEBUG_LDAP)
  log_info ("LDAP: Parsing dhcpServer options '%s' ...", hostdn);
#endif

  cfile->inbuf[0] = '\0';
  ldap_parse_entry_options(hostent, cfile->inbuf, LDAP_BUFFER_SIZE, NULL);
  cfile->buflen = strlen (cfile->inbuf);
  if(cfile->buflen > 0)
    {
      ldap_write_debug (cfile->inbuf, cfile->buflen);

      res = conf_file_subparse (cfile, root_group, ROOT_GROUP);
      if (res != ISC_R_SUCCESS)
        {
          log_error ("LDAP: cannot parse dhcpServer entry '%s'", hostdn);
          ldap_memfree (hostdn);
          ldap_stop();
          return res;
        }
      cfile->inbuf[0] = '\0';
    }
  ldap_msgfree (hostres);

  /*
  ** attach ldap (tree) read function now
  */
  cfile->bufix = cfile->buflen = 0;
  cfile->read_function = ldap_read_function;

  res = ISC_R_SUCCESS;
  for (cnt=0; tempbv[cnt] != NULL; cnt++)
    {
      snprintf(sfilter, sizeof(sfilter), "(&(objectClass=dhcpService)"
                        "(|(dhcpPrimaryDN=%s)(dhcpSecondaryDN=%s)))",
                        hostdn, hostdn);
      ldres = NULL;
      if ((ret = ldap_search_ext_s (ld, tempbv[cnt]->bv_val, LDAP_SCOPE_BASE,
                                    sfilter, NULL, 0, NULL, NULL, NULL,
                                    0, &ldres)) != LDAP_SUCCESS)
        {
          log_error ("Error searching for dhcpServiceDN '%s': %s. Please update the LDAP entry '%s'",
                     tempbv[cnt]->bv_val, ldap_err2string (ret), hostdn);
          if(NULL != ldres)
            ldap_msgfree(ldres);
          res = ISC_R_FAILURE;
          break;
        }

      if ((ent = ldap_first_entry (ld, ldres)) == NULL)
        {
          log_error ("Error: Cannot find dhcpService DN '%s' with primary or secondary server reference. Please update the LDAP server entry '%s'",
                     tempbv[cnt]->bv_val, hostdn);

          ldap_msgfree(ldres);
          res = ISC_R_FAILURE;
          break;
        }

      /*
      ** FIXME: how to free the remembered dn's on exit?
      **        This should be OK if dmalloc registers the
      **        memory it allocated and frees it on exit..
      */

      curr = dmalloc (sizeof (*curr), MDL);
      if (curr != NULL)
        {
          length = strlen (tempbv[cnt]->bv_val);
          curr->dn = dmalloc (length + 1, MDL);
          if (curr->dn == NULL)
            {
              dfree (curr, MDL);
              curr = NULL;
            }
          else
            strcpy (curr->dn, tempbv[cnt]->bv_val);
        }

      if (curr != NULL)
        {
          curr->refs++;

          /* append to service-dn list */
          if (ldap_service_dn_tail != NULL)
            ldap_service_dn_tail->next = curr;
          else
            ldap_service_dn_head = curr;

          ldap_service_dn_tail = curr;
        }
      else
        log_fatal ("no memory to remember ldap service dn");

#if defined (DEBUG_LDAP)
      log_info ("LDAP: Parsing dhcpService DN '%s' ...", tempbv[cnt]);
#endif
      add_to_config_stack (ldres, ent);
      res = conf_file_subparse (cfile, root_group, ROOT_GROUP);
      if (res != ISC_R_SUCCESS)
        {
          log_error ("LDAP: cannot parse dhcpService entry '%s'", tempbv[cnt]->bv_val);
          break;
        }
    }

  end_parse (&cfile);
  ldap_close_debug_fd();

  ldap_memfree (hostdn);
  ldap_value_free_len (tempbv);

  if (res != ISC_R_SUCCESS)
    {
      struct ldap_config_stack *temp_stack;

      while ((curr = ldap_service_dn_head) != NULL)
        {
          ldap_service_dn_head = curr->next;
          dfree (curr->dn, MDL);
          dfree (curr, MDL);
        }

      ldap_service_dn_tail = NULL;

      while ((temp_stack = ldap_stack) != NULL)
        {
          ldap_stack = temp_stack->next;
          free_stack_entry (temp_stack);
        }

      ldap_stop();
    }

  /* Unbind from ldap immediately after reading config in static mode. */
  if (ldap_method == LDAP_METHOD_STATIC)
    ldap_stop();

  return (res);
}


/* This function will parse the dhcpOption and dhcpStatements field in the LDAP
   entry if it exists. Right now, type will be either HOST_DECL or CLASS_DECL.
   If we are parsing a HOST_DECL, this always returns 0. If we are parsing a 
   CLASS_DECL, this will return what the current lease limit is in LDAP. If
   there is no lease limit specified, we return 0 */

static int
ldap_parse_options (LDAPMessage * ent, struct group *group,
                         int type, struct host_decl *host,
                         struct class **class)
{
  int declaration, lease_limit;
  char option_buffer[8192];
  enum dhcp_token token;
  struct parse *cfile;
  isc_result_t res;
  const char *val;

  lease_limit = 0;
  *option_buffer = '\0';
 
 /* This block of code will try to find the parent of the host, and
    if it is a group object, fetch the options and apply to the host. */
  if (type == HOST_DECL) 
    {
      char *hostdn, *basedn, *temp1, *temp2, filter[1024];
      LDAPMessage *groupdn, *entry;
      int ret;

      hostdn = ldap_get_dn (ld, ent);
      if( hostdn != NULL)
        {
          basedn = NULL;

          temp1 = strchr (hostdn, '=');
          if (temp1 != NULL)
            temp1 = strchr (++temp1, '=');
          if (temp1 != NULL)
            temp2 = strchr (++temp1, ',');
          else
            temp2 = NULL;

          if (temp2 != NULL)
            {
              snprintf (filter, sizeof(filter),
                        "(&(cn=%.*s)(objectClass=dhcpGroup))",
                        (int)(temp2 - temp1), temp1);

              basedn = strchr (temp1, ',');
              if (basedn != NULL)
                ++basedn;
            }

          if (basedn != NULL && *basedn != '\0')
            {
              ret = ldap_search_ext_s (ld, basedn, LDAP_SCOPE_SUBTREE, filter,
                                       NULL, 0, NULL, NULL, NULL, 0, &groupdn);
              if (ret == LDAP_SUCCESS)
                {
                  if ((entry = ldap_first_entry (ld, groupdn)) != NULL)
                    {
                      res = ldap_parse_entry_options (entry, option_buffer,
                                                      sizeof(option_buffer) - 1,
                                                      &lease_limit);
                      if (res != ISC_R_SUCCESS)
                        {
                          /* reset option buffer discarding any results */
                          *option_buffer = '\0';
                          lease_limit = 0;
                        }
                    }
                  ldap_msgfree( groupdn);
                }
            }
          ldap_memfree( hostdn);
        }
    }

  res = ldap_parse_entry_options (ent, option_buffer, sizeof(option_buffer) - 1,
                                  &lease_limit);
  if (res != ISC_R_SUCCESS)
    return (lease_limit);

  option_buffer[sizeof(option_buffer) - 1] = '\0';
  if (*option_buffer == '\0')
    return (lease_limit);

  cfile = (struct parse *) NULL;
  res = new_parse (&cfile, -1, option_buffer, strlen (option_buffer), 
                   type == HOST_DECL ? "LDAP-HOST" : "LDAP-SUBCLASS", 0);
  if (res != ISC_R_SUCCESS)
    return (lease_limit);

#if defined (DEBUG_LDAP)
  log_info ("Sending the following options: '%s'", option_buffer);
#endif

  declaration = 0;
  do
    {
      token = peek_token (&val, NULL, cfile);
      if (token == END_OF_FILE)
        break;
       declaration = parse_statement (cfile, group, type, host, declaration);
    } while (1);

  end_parse (&cfile);

  return (lease_limit);
}



int
find_haddr_in_ldap (struct host_decl **hp, int htype, unsigned hlen,
                    const unsigned char *haddr, const char *file, int line)
{
  char buf[128], *type_str;
  LDAPMessage * res, *ent;
  struct host_decl * host;
  isc_result_t status;
  ldap_dn_node *curr;
  int ret;

  if (ldap_method == LDAP_METHOD_STATIC)
    return (0);

  if (ld == NULL)
    ldap_start ();
  if (ld == NULL)
    return (0);

  switch (htype)
    {
      case HTYPE_ETHER:
        type_str = "ethernet";
        break;
      case HTYPE_IEEE802:
        type_str = "token-ring";
        break;
      case HTYPE_FDDI:
        type_str = "fddi";
        break;
      default:
        log_info ("Ignoring unknown type %d", htype);
        return (0);
    }

  /*
  ** FIXME: It is not guaranteed, that the dhcpHWAddress attribute
  **        contains _exactly_ "type addr" with one space between!
  */
  snprintf (buf, sizeof (buf),
            "(&(objectClass=dhcpHost)(dhcpHWAddress=%s %s))",
           type_str, print_hw_addr (htype, hlen, haddr));

  res = ent = NULL;
  for (curr = ldap_service_dn_head;
       curr != NULL && *curr->dn != '\0';
       curr = curr->next)
    {
#if defined (DEBUG_LDAP)
      log_info ("Searching for %s in LDAP tree %s", buf, curr->dn);
#endif
      ret = ldap_search_ext_s (ld, curr->dn, LDAP_SCOPE_SUBTREE, buf, NULL, 0,
                               NULL, NULL, NULL, 0, &res);

      if(ret == LDAP_SERVER_DOWN)
        {
          log_info ("LDAP server was down, trying to reconnect...");

          ldap_stop();
          ldap_start();
          if(ld == NULL)
            {
              log_info ("LDAP reconnect failed - try again later...");
              return (0);
            }

          ret = ldap_search_ext_s (ld, curr->dn, LDAP_SCOPE_SUBTREE, buf, NULL,
                                   0, NULL, NULL, NULL, 0, &res);
        }

      if (ret == LDAP_SUCCESS)
        {
          if( (ent = ldap_first_entry (ld, res)) != NULL)
            break; /* search OK and have entry */

#if defined (DEBUG_LDAP)
          log_info ("No host entry for %s in LDAP tree %s",
                    buf, curr->dn);
#endif
          if(res)
            {
              ldap_msgfree (res);
              res = NULL;
            }
        }
      else
        {
          if(res)
            {
              ldap_msgfree (res);
              res = NULL;
            }

          if (ret != LDAP_NO_SUCH_OBJECT && ret != LDAP_SUCCESS)
            {
              log_error ("Cannot search for %s in LDAP tree %s: %s", buf, 
                         curr->dn, ldap_err2string (ret));
              ldap_stop();
              return (0);
            }
#if defined (DEBUG_LDAP)
          else
            {
              log_info ("ldap_search_ext_s returned %s when searching for %s in %s",
                        ldap_err2string (ret), buf, curr->dn);
            }
#endif
        }
    }

  if (res && ent)
    {
#if defined (DEBUG_LDAP)
      char *dn = ldap_get_dn (ld, ent);
      if (dn != NULL)
        {
          log_info ("Found dhcpHWAddress LDAP entry %s", dn);
          ldap_memfree(dn);
        }
#endif

      host = (struct host_decl *)0;
      status = host_allocate (&host, MDL);
      if (status != ISC_R_SUCCESS)
        {
          log_fatal ("can't allocate host decl struct: %s", 
                     isc_result_totext (status)); 
          ldap_msgfree (res);
          return (0);
        }

      host->name = ldap_get_host_name (ent);
      if (host->name == NULL)
        {
          host_dereference (&host, MDL);
          ldap_msgfree (res);
          return (0);
        }

      if (!clone_group (&host->group, root_group, MDL))
        {
          log_fatal ("can't clone group for host %s", host->name);
          host_dereference (&host, MDL);
          ldap_msgfree (res);
          return (0);
        }

      ldap_parse_options (ent, host->group, HOST_DECL, host, NULL);

      *hp = host;
      ldap_msgfree (res);
      return (1);
    }


  if(res) ldap_msgfree (res);
  return (0);
}


int
find_subclass_in_ldap (struct class *class, struct class **newclass, 
                       struct data_string *data)
{
  LDAPMessage * res, * ent;
  int ret, lease_limit;
  isc_result_t status;
  ldap_dn_node *curr;
  char buf[1024];

  if (ldap_method == LDAP_METHOD_STATIC)
    return (0);

  if (ld == NULL)
    ldap_start ();
  if (ld == NULL)
    return (0);

  snprintf (buf, sizeof (buf),
            "(&(objectClass=dhcpSubClass)(cn=%s)(dhcpClassData=%s))",
            print_hex_1 (data->len, data->data, 60),
            print_hex_2 (strlen (class->name), (u_int8_t *) class->name, 60));
#if defined (DEBUG_LDAP)
  log_info ("Searching LDAP for %s", buf);
#endif

  res = ent = NULL;
  for (curr = ldap_service_dn_head;
       curr != NULL && *curr->dn != '\0';
       curr = curr->next)
    {
#if defined (DEBUG_LDAP)
      log_info ("Searching for %s in LDAP tree %s", buf, curr->dn);
#endif
      ret = ldap_search_ext_s (ld, curr->dn, LDAP_SCOPE_SUBTREE, buf, NULL, 0,
                               NULL, NULL, NULL, 0, &res);

      if(ret == LDAP_SERVER_DOWN)
        {
          log_info ("LDAP server was down, trying to reconnect...");

          ldap_stop();
          ldap_start();

          if(ld == NULL)
            {
              log_info ("LDAP reconnect failed - try again later...");
              return (0);
            }

          ret = ldap_search_ext_s (ld, curr->dn, LDAP_SCOPE_SUBTREE, buf,
                                   NULL, 0, NULL, NULL, NULL, 0, &res);
        }

      if (ret == LDAP_SUCCESS)
        {
          if( (ent = ldap_first_entry (ld, res)) != NULL)
            break; /* search OK and have entry */

#if defined (DEBUG_LDAP)
          log_info ("No subclass entry for %s in LDAP tree %s",
                    buf, curr->dn);
#endif
          if(res)
            {
              ldap_msgfree (res);
              res = NULL;
            }
        }
      else
        {
          if(res)
            {
              ldap_msgfree (res);
              res = NULL;
            }

          if (ret != LDAP_NO_SUCH_OBJECT && ret != LDAP_SUCCESS)
            {
              log_error ("Cannot search for %s in LDAP tree %s: %s", buf, 
                         curr->dn, ldap_err2string (ret));
              ldap_stop();
              return (0);
            }
#if defined (DEBUG_LDAP)
          else
            {
              log_info ("ldap_search_ext_s returned %s when searching for %s in %s",
                        ldap_err2string (ret), buf, curr->dn);
            }
#endif
        }
    }

  if (res && ent)
    {
#if defined (DEBUG_LDAP)
      char *dn = ldap_get_dn (ld, ent);
      if (dn != NULL)
        {
          log_info ("Found subclass LDAP entry %s", dn);
          ldap_memfree(dn);
        }
#endif

      status = class_allocate (newclass, MDL);
      if (status != ISC_R_SUCCESS)
        {
          log_error ("Cannot allocate memory for a new class");
          ldap_msgfree (res);
          return (0);
        }

      group_reference (&(*newclass)->group, class->group, MDL);
      class_reference (&(*newclass)->superclass, class, MDL);
      lease_limit = ldap_parse_options (ent, (*newclass)->group, 
                                        CLASS_DECL, NULL, newclass);
      if (lease_limit == 0)
        (*newclass)->lease_limit = class->lease_limit; 
      else
        class->lease_limit = lease_limit;

      if ((*newclass)->lease_limit) 
        {
          (*newclass)->billed_leases = 
              dmalloc ((*newclass)->lease_limit * sizeof (struct lease *), MDL);
          if (!(*newclass)->billed_leases) 
            {
              log_error ("no memory for billing");
              class_dereference (newclass, MDL);
              ldap_msgfree (res);
              return (0);
            }
          memset ((*newclass)->billed_leases, 0, 
                ((*newclass)->lease_limit * sizeof (*newclass)->billed_leases));
        }

      data_string_copy (&(*newclass)->hash_string, data, MDL);

      ldap_msgfree (res);
      return (1);
    }

  if(res) ldap_msgfree (res);
  return (0);
}

#endif
