path: root/source3/libsmb/dsgetdcname.c

/*
   Unix SMB/CIFS implementation.

   DsGetDcname

   Copyright (C) Gerald Carter 2006
   Copyright (C) Guenther Deschner 2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"

#define DSGETDCNAME_FMT	"DSGETDCNAME/DOMAIN/%s"
/* 15 minutes */
#define DSGETDCNAME_CACHE_TTL	60*15

struct ip_service_name {
	struct in_addr ip;
	unsigned port;
	const char *hostname;
};

/****************************************************************
****************************************************************/

void debug_dsdcinfo_flags(int lvl, uint32_t flags)
{
	DEBUG(lvl,("debug_dsdcinfo_flags: 0x%08x\n\t", flags));

	if (flags & DS_FORCE_REDISCOVERY)
		DEBUGADD(lvl,("DS_FORCE_REDISCOVERY "));
	if (flags & 0x000000002)
		DEBUGADD(lvl,("0x00000002 "));
	if (flags & 0x000000004)
		DEBUGADD(lvl,("0x00000004 "));
	if (flags & 0x000000008)
		DEBUGADD(lvl,("0x00000008 "));
	if (flags & DS_DIRECTORY_SERVICE_REQUIRED)
		DEBUGADD(lvl,("DS_DIRECTORY_SERVICE_REQUIRED "));
	if (flags & DS_DIRECTORY_SERVICE_PREFERRED)
		DEBUGADD(lvl,("DS_DIRECTORY_SERVICE_PREFERRED "));
	if (flags & DS_GC_SERVER_REQUIRED)
		DEBUGADD(lvl,("DS_GC_SERVER_REQUIRED "));
	if (flags & DS_PDC_REQUIRED)
		DEBUGADD(lvl,("DS_PDC_REQUIRED "));
	if (flags & DS_BACKGROUND_ONLY)
		DEBUGADD(lvl,("DS_BACKGROUND_ONLY "));
	if (flags & DS_IP_REQUIRED)
		DEBUGADD(lvl,("DS_IP_REQUIRED "));
	if (flags & DS_KDC_REQUIRED)
		DEBUGADD(lvl,("DS_KDC_REQUIRED "));
	if (flags & DS_TIMESERV_REQUIRED)
		DEBUGADD(lvl,("DS_TIMESERV_REQUIRED "));
	if (flags & DS_WRITABLE_REQUIRED)
		DEBUGADD(lvl,("DS_WRITABLE_REQUIRED "));
	if (flags & DS_GOOD_TIMESERV_PREFERRED)
		DEBUGADD(lvl,("DS_GOOD_TIMESERV_PREFERRED "));
	if (flags & DS_AVOID_SELF)
		DEBUGADD(lvl,("DS_AVOID_SELF "));
	if (flags & DS_ONLY_LDAP_NEEDED)
		DEBUGADD(lvl,("DS_ONLY_LDAP_NEEDED "));
	if (flags & 0x00010000)
		DEBUGADD(lvl,("0x00010000 "));
	if (flags & 0x00020000)
		DEBUGADD(lvl,("0x00020000 "));
	if (flags & 0x00040000)
		DEBUGADD(lvl,("0x00040000 "));
	if (flags & 0x00080000)
		DEBUGADD(lvl,("0x00080000 "));
	if (flags & DS_IS_FLAT_NAME)
		DEBUGADD(lvl,("DS_IS_FLAT_NAME "));
	if (flags & DS_IS_DNS_NAME)
		DEBUGADD(lvl,("DS_IS_DNS_NAME "));
	if (flags & 0x00040000)
		DEBUGADD(lvl,("0x00040000 "));
	if (flags & 0x00080000)
		DEBUGADD(lvl,("0x00080000 "));
	if (flags & 0x00100000)
		DEBUGADD(lvl,("0x00100000 "));
	if (flags & 0x00200000)
		DEBUGADD(lvl,("0x00200000 "));
	if (flags & 0x00400000)
		DEBUGADD(lvl,("0x00400000 "));
	if (flags & 0x00800000)
		DEBUGADD(lvl,("0x00800000 "));
	if (flags & 0x01000000)
		DEBUGADD(lvl,("0x01000000 "));
	if (flags & 0x02000000)
		DEBUGADD(lvl,("0x02000000 "));
	if (flags & 0x04000000)
		DEBUGADD(lvl,("0x04000000 "));
	if (flags & 0x08000000)
		DEBUGADD(lvl,("0x08000000 "));
	if (flags & 0x10000000)
		DEBUGADD(lvl,("0x10000000 "));
	if (flags & 0x20000000)
		DEBUGADD(lvl,("0x20000000 "));
	if (flags & DS_RETURN_DNS_NAME)
		DEBUGADD(lvl,("DS_RETURN_DNS_NAME "));
	if (flags & DS_RETURN_FLAT_NAME)
		DEBUGADD(lvl,("DS_RETURN_FLAT_NAME "));
	if (flags)
		DEBUGADD(lvl,("\n"));
}

/*********************************************************************
 ********************************************************************/

static int pack_dsdcinfo(struct DS_DOMAIN_CONTROLLER_INFO *info,
			 unsigned char **buf)
{
	unsigned char *buffer = NULL;
	int len = 0;
	int buflen = 0;
	UUID_FLAT guid_flat;

	DEBUG(10,("pack_dsdcinfo: Packing dsdcinfo\n"));

	ZERO_STRUCT(guid_flat);

	if (info->domain_guid) {
		const struct GUID *guid = info->domain_guid;
		smb_uuid_pack(*guid, &guid_flat);
	}

 again:
	len = 0;

	if (buflen > 0) {
		DEBUG(10,("pack_dsdcinfo: Packing domain %s (%s)\n",
			  info->domain_name, info->domain_controller_name));
	}

	len += tdb_pack(buffer+len, buflen-len, "ffdBffdff",
			info->domain_controller_name,
			info->domain_controller_address,
			info->domain_controller_address_type,
			UUID_FLAT_SIZE, guid_flat.info,
			info->domain_name,
			info->dns_forest_name,
			info->flags,
			info->dc_site_name,
			info->client_site_name);

	if (buflen < len) {
		SAFE_FREE(buffer);
		if ((buffer = SMB_MALLOC_ARRAY(unsigned char, len)) == NULL ) {
			DEBUG(0,("pack_dsdcinfo: failed to alloc buffer!\n"));
			buflen = -1;
			goto done;
		}
		buflen = len;
		goto again;
	}

	*buf = buffer;

 done:
	return buflen;
}

/*********************************************************************
 ********************************************************************/

static NTSTATUS unpack_dsdcinfo(TALLOC_CTX *mem_ctx,
				unsigned char *buf,
				int buflen,
				struct DS_DOMAIN_CONTROLLER_INFO **info_ret)
{
	int len = 0;
	struct DS_DOMAIN_CONTROLLER_INFO *info = NULL;
	uint32_t guid_len = 0;
	unsigned char *guid_buf = NULL;
	UUID_FLAT guid_flat;

	/* forgive me 6 times */
	fstring domain_controller_name;
	fstring domain_controller_address;
	fstring domain_name;
	fstring dns_forest_name;
	fstring dc_site_name;
	fstring client_site_name;

	info = TALLOC_ZERO_P(mem_ctx, struct DS_DOMAIN_CONTROLLER_INFO);
	NT_STATUS_HAVE_NO_MEMORY(info);

	len += tdb_unpack(buf+len, buflen-len, "ffdBffdff",
			  &domain_controller_name,
			  &domain_controller_address,
			  &info->domain_controller_address_type,
			  &guid_len, &guid_buf,
			  &domain_name,
			  &dns_forest_name,
			  &info->flags,
			  &dc_site_name,
			  &client_site_name);
	if (len == -1) {
		DEBUG(5,("unpack_dsdcinfo: Failed to unpack domain\n"));
		goto failed;
	}

	info->domain_controller_name =
		talloc_strdup(mem_ctx, domain_controller_name);
	info->domain_controller_address =
		talloc_strdup(mem_ctx, domain_controller_address);
	info->domain_name =
		talloc_strdup(mem_ctx, domain_name);
	info->dns_forest_name =
		talloc_strdup(mem_ctx, dns_forest_name);
	info->dc_site_name =
		talloc_strdup(mem_ctx, dc_site_name);
	info->client_site_name =
		talloc_strdup(mem_ctx, client_site_name);

	if (!info->domain_controller_name ||
	    !info->domain_controller_address ||
	    !info->domain_name ||
	    !info->dns_forest_name ||
	    !info->dc_site_name ||
	    !info->client_site_name) {
		goto failed;
	}

	if (guid_len > 0) {
		struct GUID guid;

		if (guid_len != UUID_FLAT_SIZE) {
			goto failed;
		}

		memcpy(&guid_flat.info, guid_buf, guid_len);
		smb_uuid_unpack(guid_flat, &guid);

		info->domain_guid = talloc_memdup(mem_ctx, &guid, sizeof(guid));
		if (!info->domain_guid) {
			goto failed;
		}
		SAFE_FREE(guid_buf);
	}

	DEBUG(10,("unpack_dcscinfo: Unpacked domain %s (%s)\n",
		  info->domain_name, info->domain_controller_name));

	*info_ret = info;

	return NT_STATUS_OK;

 failed:
 	TALLOC_FREE(info);
	SAFE_FREE(guid_buf);
	return NT_STATUS_NO_MEMORY;
}

/****************************************************************
****************************************************************/

static char *DsGetDcName_cache_key(TALLOC_CTX *mem_ctx, const char *domain)
{
	if (!mem_ctx || !domain) {
		return NULL;
	}

	return talloc_asprintf(mem_ctx, DSGETDCNAME_FMT,
			       strupper_static(domain));
}

/****************************************************************
****************************************************************/

static NTSTATUS DsGetDcName_cache_delete(TALLOC_CTX *mem_ctx,
					const char *domain_name)
{
	char *key;

	if (!gencache_init()) {
		return NT_STATUS_INTERNAL_DB_ERROR;
	}

	key = DsGetDcName_cache_key(mem_ctx, domain_name);
	if (!key) {
		return NT_STATUS_NO_MEMORY;
	}

	if (!gencache_del(key)) {
		return NT_STATUS_UNSUCCESSFUL;
	}

	return NT_STATUS_OK;
}

/****************************************************************
****************************************************************/

static NTSTATUS DsGetDcName_cache_store(TALLOC_CTX *mem_ctx,
					const char *domain_name,
					struct DS_DOMAIN_CONTROLLER_INFO *info)
{
	time_t expire_time;
	char *key;
	BOOL ret = False;
	DATA_BLOB blob;
	unsigned char *buf = NULL;
	int len = 0;

	if (!gencache_init()) {
		return NT_STATUS_INTERNAL_DB_ERROR;
	}

	key = DsGetDcName_cache_key(mem_ctx, domain_name);
	if (!key) {
		return NT_STATUS_NO_MEMORY;
	}

	expire_time = time(NULL) + DSGETDCNAME_CACHE_TTL;

	len = pack_dsdcinfo(info, &buf);
	if (len == -1) {
		return NT_STATUS_UNSUCCESSFUL;
	}

	blob = data_blob(buf, len);
	SAFE_FREE(buf);

	if (gencache_lock_entry(key) != 0) {
		data_blob_free(&blob);
		return NT_STATUS_LOCK_NOT_GRANTED;
	}

	ret = gencache_set_data_blob(key, &blob, expire_time);
	data_blob_free(&blob);

	gencache_unlock_entry(key);

	return ret ? NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

/****************************************************************
****************************************************************/

static NTSTATUS DsGetDcName_cache_refresh(TALLOC_CTX *mem_ctx,
					  const char *domain_name,
					  struct GUID *domain_guid,
					  uint32_t flags,
					  const char *site_name,
					  struct DS_DOMAIN_CONTROLLER_INFO *info)
{
	struct cldap_netlogon_reply r;

	/* check if matching entry is older then 15 minutes, if yes, send
	 * CLDAP/MAILSLOT ping again and store the cached data */

	ZERO_STRUCT(r);

	if (ads_cldap_netlogon(info->domain_controller_name,
			       info->domain_name, &r)) {

		DsGetDcName_cache_delete(mem_ctx, domain_name);

		return DsGetDcName_cache_store(mem_ctx,
					       info->domain_name,
					       info);
	}

	return NT_STATUS_INVALID_NETWORK_RESPONSE;
}

/****************************************************************
****************************************************************/

#define RETURN_ON_FALSE(x) if (!x) return False;

static BOOL check_cldap_reply_required_flags(uint32_t ret_flags,
					     uint32_t req_flags)
{
	if (req_flags & DS_PDC_REQUIRED)
		RETURN_ON_FALSE(ret_flags & ADS_PDC);

	if (req_flags & DS_GC_SERVER_REQUIRED)
		RETURN_ON_FALSE(ret_flags & ADS_GC);

	if (req_flags & DS_ONLY_LDAP_NEEDED)
		RETURN_ON_FALSE(ret_flags & ADS_LDAP);

	if ((req_flags & DS_DIRECTORY_SERVICE_REQUIRED) ||
	    (req_flags & DS_DIRECTORY_SERVICE_PREFERRED))
		RETURN_ON_FALSE(ret_flags & ADS_DS);

	if (req_flags & DS_KDC_REQUIRED)
		RETURN_ON_FALSE(ret_flags & ADS_KDC);

	if (req_flags & DS_TIMESERV_REQUIRED)
		RETURN_ON_FALSE(ret_flags & ADS_TIMESERV);

	if (req_flags & DS_WRITABLE_REQUIRED)
		RETURN_ON_FALSE(ret_flags & ADS_WRITABLE);

	return True;
}

/****************************************************************
****************************************************************/

static NTSTATUS DsGetDcName_cache_fetch(TALLOC_CTX *mem_ctx,
					const char *domain_name,
					struct GUID *domain_guid,
					uint32_t flags,
					const char *site_name,
					struct DS_DOMAIN_CONTROLLER_INFO **info,
					BOOL *expired)
{
	char *key;
	DATA_BLOB blob;
	NTSTATUS status;

	if (!gencache_init()) {
		return NT_STATUS_INTERNAL_DB_ERROR;
	}

	key = DsGetDcName_cache_key(mem_ctx, domain_name);
	if (!key) {
		return NT_STATUS_NO_MEMORY;
	}

	if (!gencache_get_data_blob(key, &blob, expired)) {
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}

	status = unpack_dsdcinfo(mem_ctx, blob.data, blob.length, info);
	if (!NT_STATUS_IS_OK(status)) {
		data_blob_free(&blob);
		return status;
	}

	data_blob_free(&blob);

	/* check flags */
	if (!check_cldap_reply_required_flags((*info)->flags, flags)) {
		DEBUG(10,("invalid flags\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if ((flags & DS_IP_REQUIRED) &&
	    !((*info)->domain_controller_address_type != ADS_INET_ADDRESS)) {
	    	return NT_STATUS_INVALID_PARAMETER_MIX;
	}

	return NT_STATUS_OK;
}

/****************************************************************
****************************************************************/

static NTSTATUS DsGetDcName_cached(TALLOC_CTX *mem_ctx,
				   const char *domain_name,
				   struct GUID *domain_guid,
				   uint32_t flags,
				   const char *site_name,
				   struct DS_DOMAIN_CONTROLLER_INFO **info)
{
	NTSTATUS status;
	BOOL expired = False;

	status = DsGetDcName_cache_fetch(mem_ctx, domain_name, domain_guid,
					 flags, site_name, info, &expired);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(10,("DsGetDcName_cached: cache fetch failed with: %s\n",
			nt_errstr(status)));
		return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
	}

	if (flags & DS_BACKGROUND_ONLY) {
		return status;
	}

	if (expired) {
		status = DsGetDcName_cache_refresh(mem_ctx, domain_name,
						   domain_guid, flags,
						   site_name, *info);
		if (!NT_STATUS_IS_OK(status)) {
			return status;
		}
	}

	return status;
}

/****************************************************************
****************************************************************/

static BOOL check_allowed_required_flags(uint32_t flags)
{
	uint32_t return_type = flags & (DS_RETURN_FLAT_NAME|DS_RETURN_DNS_NAME);
	uint32_t offered_type = flags & (DS_IS_FLAT_NAME|DS_IS_DNS_NAME);
	uint32_t query_type = flags & (DS_BACKGROUND_ONLY|DS_FORCE_REDISCOVERY);

	/* FIXME: check for DSGETDC_VALID_FLAGS and check for excluse bits
	 * (DS_PDC_REQUIRED, DS_KDC_REQUIRED, DS_GC_SERVER_REQUIRED) */

	debug_dsdcinfo_flags(10, flags);

	if (return_type == (DS_RETURN_FLAT_NAME|DS_RETURN_DNS_NAME)) {
		return False;
	}

	if (offered_type == (DS_IS_DNS_NAME|DS_IS_FLAT_NAME)) {
		return False;
	}

	if (query_type == (DS_BACKGROUND_ONLY|DS_FORCE_REDISCOVERY)) {
		return False;
	}

#if 0
	if ((flags & DS_RETURN_DNS_NAME) && (!(flags & DS_IP_REQUIRED))) {
		printf("gd: here5 \n");
		return False;
	}
#endif
	return True;
}

/****************************************************************
****************************************************************/

static NTSTATUS discover_dc_netbios(TALLOC_CTX *mem_ctx,
				    const char *domain_name,
				    uint32_t flags,
				    struct ip_service_name **returned_dclist,
				    int *return_count)
{
	if (lp_disable_netbios()) {
		return NT_STATUS_NOT_SUPPORTED;
	}

	/* FIXME: code here */

	return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
}

/****************************************************************
****************************************************************/

static NTSTATUS discover_dc_dns(TALLOC_CTX *mem_ctx,
				const char *domain_name,
				struct GUID *domain_guid,
				uint32_t flags,
				const char *site_name,
				struct ip_service_name **returned_dclist,
				int *return_count)
{
	int i, j;
	NTSTATUS status;
	struct dns_rr_srv *dcs = NULL;
	int numdcs = 0;
	int numaddrs = 0;

	if ((!(flags & DS_DIRECTORY_SERVICE_REQUIRED)) &&
	    (!(flags & DS_KDC_REQUIRED)) &&
	    (!(flags & DS_GC_SERVER_REQUIRED)) &&
	    (!(flags & DS_PDC_REQUIRED))) {
	    	DEBUG(1,("discover_dc_dns: invalid flags\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (flags & DS_PDC_REQUIRED) {
		status = ads_dns_query_pdc(mem_ctx, domain_name,
					   &dcs, &numdcs);
	} else if (flags & DS_GC_SERVER_REQUIRED) {
		status = ads_dns_query_gcs(mem_ctx, domain_name, site_name,
					   &dcs, &numdcs);
	} else if (flags & DS_KDC_REQUIRED) {
		status = ads_dns_query_kdcs(mem_ctx, domain_name, site_name,
					    &dcs, &numdcs);
	} else if (flags & DS_DIRECTORY_SERVICE_REQUIRED) {
		status = ads_dns_query_dcs(mem_ctx, domain_name, site_name,
					   &dcs, &numdcs);
	} else if (domain_guid) {
		status = ads_dns_query_dcs_guid(mem_ctx, domain_name,
						domain_guid, &dcs, &numdcs);
	} else {
		/* FIXME: ? */
	    	DEBUG(1,("discover_dc_dns: not enough input\n"));
		status = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
	}

	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	if (numdcs == 0) {
		return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
	}

	for (i=0;i<numdcs;i++) {
		numaddrs += MAX(dcs[i].num_ips,1);
	}

	if ((*returned_dclist = TALLOC_ZERO_ARRAY(mem_ctx,
						  struct ip_service_name,
						  numaddrs)) == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	/* now unroll the list of IP addresses */

	*return_count = 0;
	i = 0;
	j = 0;
	while (i < numdcs && (*return_count<numaddrs)) {

		struct ip_service_name *r = &(*returned_dclist)[*return_count];

		r->port = dcs[i].port;
		r->hostname = dcs[i].hostname;

		if (!(flags & DS_IP_REQUIRED)) {
			(*return_count)++;
			continue;
		}

		/* If we don't have an IP list for a name, lookup it up */

		if (!dcs[i].ips) {
			r->ip = *interpret_addr2(dcs[i].hostname);
			i++;
			j = 0;
		} else {
			/* use the IP addresses from the SRV sresponse */

			if (j >= dcs[i].num_ips) {
				i++;
				j = 0;
				continue;
			}

			r->ip = dcs[i].ips[j];
			j++;
		}

		/* make sure it is a valid IP.  I considered checking the
		 * negative connection cache, but this is the wrong place for
		 * it.  Maybe only as a hac.  After think about it, if all of
		 * the IP addresses retuend from DNS are dead, what hope does a
		 * netbios name lookup have?  The standard reason for falling
		 * back to netbios lookups is that our DNS server doesn't know
		 * anything about the DC's   -- jerry */

		if (!is_zero_ip(r->ip)) {
			(*return_count)++;
			continue;
		}
	}

	return (*return_count > 0) ? NT_STATUS_OK :
				     NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
}

/****************************************************************
****************************************************************/

static NTSTATUS make_domain_controller_info(TALLOC_CTX *mem_ctx,
					    const char *domain_controller_name,
					    const char *domain_controller_address,
					    uint32_t domain_controller_address_type,
					    const struct GUID *domain_guid,
					    const char *domain_name,
					    const char *dns_forest_name,
					    uint32_t flags,
					    const char *dc_site_name,
					    const char *client_site_name,
					    struct DS_DOMAIN_CONTROLLER_INFO **info_out)
{
	struct DS_DOMAIN_CONTROLLER_INFO *info;

	info = TALLOC_ZERO_P(mem_ctx, struct DS_DOMAIN_CONTROLLER_INFO);
	NT_STATUS_HAVE_NO_MEMORY(info);

	if (domain_controller_name) {
		info->domain_controller_name = talloc_strdup(mem_ctx,
			domain_controller_name);
		NT_STATUS_HAVE_NO_MEMORY(info->domain_controller_name);
	}

	if (domain_controller_address) {
		info->domain_controller_address = talloc_strdup(mem_ctx,
			domain_controller_address);
		NT_STATUS_HAVE_NO_MEMORY(info->domain_controller_address);
	}

	info->domain_controller_address_type = domain_controller_address_type;

	if (domain_guid) {
		info->domain_guid = talloc_memdup(mem_ctx, domain_guid,
						  sizeof(*domain_guid));
		NT_STATUS_HAVE_NO_MEMORY(info->domain_guid);
	}

	if (domain_name) {
		info->domain_name = talloc_strdup(mem_ctx, domain_name);
		NT_STATUS_HAVE_NO_MEMORY(info->domain_name);
	}

	if (dns_forest_name) {
		info->dns_forest_name = talloc_strdup(mem_ctx,
						      dns_forest_name);
		NT_STATUS_HAVE_NO_MEMORY(info->dns_forest_name);
	}

	info->flags = flags;

	if (dc_site_name) {
		info->dc_site_name = talloc_strdup(mem_ctx, dc_site_name);
		NT_STATUS_HAVE_NO_MEMORY(info->dc_site_name);
	}

	if (client_site_name) {
		info->client_site_name = talloc_strdup(mem_ctx,
						       client_site_name);
		NT_STATUS_HAVE_NO_MEMORY(info->client_site_name);
	}

	*info_out = info;

	return NT_STATUS_OK;
}

/****************************************************************
****************************************************************/

static NTSTATUS process_dc_dns(TALLOC_CTX *mem_ctx,
			       const char *domain_name,
			       uint32_t flags,
			       struct ip_service_name **dclist,
			       int num_dcs,
			       struct DS_DOMAIN_CONTROLLER_INFO **info)
{
	int i = 0;
	BOOL valid_dc = False;
	struct cldap_netlogon_reply r;
	const char *dc_hostname, *dc_domain_name;
	const char *dc_address;
	uint32_t dc_address_type;
	uint32_t dc_flags;
	struct GUID dc_guid;

	for (i=0; i<num_dcs; i++) {

		ZERO_STRUCT(r);

		if ((ads_cldap_netlogon(dclist[i]->hostname,
					domain_name, &r)) &&
		    (check_cldap_reply_required_flags(r.flags, flags))) {
			valid_dc = True;
		    	break;
		}

		continue;
	}

	if (!valid_dc) {
		return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
	}

	dc_flags = r.flags;

	if (flags & DS_RETURN_FLAT_NAME) {
		if (!strlen(r.netbios_hostname) || !strlen(r.netbios_domain)) {
			return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
		}
		dc_hostname = r.netbios_hostname;
		dc_domain_name = r.netbios_domain;
	} else if (flags & DS_RETURN_DNS_NAME) {
		if (!strlen(r.hostname) || !strlen(r.domain)) {
			return NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
		}
		dc_hostname = r.hostname;
		dc_domain_name = r.domain;
		dc_flags |= ADS_DNS_DOMAIN | ADS_DNS_CONTROLLER;
	} else {
		/* FIXME */
		dc_hostname = r.hostname;
		dc_domain_name = r.domain;
		dc_flags |= ADS_DNS_DOMAIN | ADS_DNS_CONTROLLER;
	}

	if (flags & DS_IP_REQUIRED) {
		dc_address = talloc_asprintf(mem_ctx, "\\\\%s",
					     inet_ntoa(dclist[i]->ip));
		dc_address_type = ADS_INET_ADDRESS;
	} else {
		dc_address = talloc_asprintf(mem_ctx, "\\\\%s",
					     r.netbios_hostname);
		dc_address_type = ADS_NETBIOS_ADDRESS;
	}
	NT_STATUS_HAVE_NO_MEMORY(dc_address);
	dc_guid = smb_uuid_unpack_static(r.guid);

	if (r.forest) {
		dc_flags |= ADS_DNS_FOREST;
	}

	return make_domain_controller_info(mem_ctx,
					   dc_hostname,
					   dc_address,
					   dc_address_type,
					   &dc_guid,
					   dc_domain_name,
					   r.forest,
					   dc_flags,
					   r.server_site_name,
					   r.client_site_name,
					   info);

}

/****************************************************************
****************************************************************/

static NTSTATUS process_dc_netbios(TALLOC_CTX *mem_ctx,
				   const char *domain_name,
				   uint32_t flags,
				   struct ip_service_name **dclist,
				   int num_dcs,
				   struct DS_DOMAIN_CONTROLLER_INFO **info)
{
	/* FIXME: code here */

	return NT_STATUS_NOT_SUPPORTED;
}

/****************************************************************
****************************************************************/

static NTSTATUS DsGetDcName_rediscover(TALLOC_CTX *mem_ctx,
				       const char *domain_name,
				       struct GUID *domain_guid,
				       uint32_t flags,
				       const char *site_name,
				       struct DS_DOMAIN_CONTROLLER_INFO **info)
{
	NTSTATUS status = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
	struct ip_service_name *dclist;
	int num_dcs;

	DEBUG(10,("DsGetDcName_rediscover\n"));

	if (flags & DS_IS_FLAT_NAME) {

		status = discover_dc_netbios(mem_ctx, domain_name, flags,
					     &dclist, &num_dcs);
		NT_STATUS_NOT_OK_RETURN(status);

		return process_dc_netbios(mem_ctx, domain_name, flags,
					  &dclist, num_dcs, info);
	}

	if (flags & DS_IS_DNS_NAME) {

		status = discover_dc_dns(mem_ctx, domain_name, domain_guid,
					 flags, site_name, &dclist, &num_dcs);
		NT_STATUS_NOT_OK_RETURN(status);

		return process_dc_dns(mem_ctx, domain_name, flags,
				      &dclist, num_dcs, info);
	}

	status = discover_dc_dns(mem_ctx, domain_name, domain_guid, flags,
				 site_name, &dclist, &num_dcs);

	if (NT_STATUS_IS_OK(status) && num_dcs != 0) {

		status = process_dc_dns(mem_ctx, domain_name, flags, &dclist,
					num_dcs, info);
		if (NT_STATUS_IS_OK(status)) {
			return status;
		}
	}

	status = discover_dc_netbios(mem_ctx, domain_name, flags, &dclist,
				     &num_dcs);
	NT_STATUS_NOT_OK_RETURN(status);

	return process_dc_netbios(mem_ctx, domain_name, flags, &dclist,
				  num_dcs, info);
}

/********************************************************************
 DsGetDcName.

 This will be the only public function here.
********************************************************************/

NTSTATUS DsGetDcName(TALLOC_CTX *mem_ctx,
		     const char *computer_name,
		     const char *domain_name,
		     struct GUID *domain_guid,
		     const char *site_name,
		     uint32_t flags,
		     struct DS_DOMAIN_CONTROLLER_INFO **info)
{
	NTSTATUS status = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
	struct DS_DOMAIN_CONTROLLER_INFO *myinfo = NULL;

	DEBUG(10,("DsGetDcName: computer_name: %s, domain_name: %s, "
		  "domain_guid: %s, site_name: %s, flags: 0x%08x\n",
		  computer_name, domain_name,
		  domain_guid ? GUID_string(mem_ctx, domain_guid) : "(null)",
		  site_name, flags));

	*info = NULL;

	if (!check_allowed_required_flags(flags)) {
		DEBUG(0,("invalid flags specified\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (flags & DS_FORCE_REDISCOVERY) {
		goto rediscover;
	}

	status = DsGetDcName_cached(mem_ctx, domain_name, domain_guid,
				    flags, site_name, &myinfo);
	if (NT_STATUS_IS_OK(status)) {
		*info = myinfo;
		return status;
	}

	if (flags & DS_BACKGROUND_ONLY) {
		return status;
	}

 rediscover:
	status = DsGetDcName_rediscover(mem_ctx, domain_name,
					domain_guid, flags, site_name,
					&myinfo);

 	if (NT_STATUS_IS_OK(status)) {
		DsGetDcName_cache_store(mem_ctx, domain_name, myinfo);
		*info = myinfo;
	}

	return status;
}