samba-mirror/source3/groupdb/mapping.c

/* 
 *  Unix SMB/CIFS implementation.
 *  RPC Pipe client / server routines
 *  Copyright (C) Andrew Tridgell              1992-2000,
 *  Copyright (C) Jean Fran<EFBFBD>ois Micouleau      1998-2001.
 *  
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "includes.h"

static TDB_CONTEXT *tdb; /* used for driver files */

#define DATABASE_VERSION_V1 1 /* native byte format. */
#define DATABASE_VERSION_V2 2 /* le format. */

#define GROUP_PREFIX "UNIXGROUP/"

/* Alias memberships are stored reverse, as memberships. The performance
 * critical operation is to determine the aliases a SID is member of, not
 * listing alias members. So we store a list of alias SIDs a SID is member of
 * hanging of the member as key.
 */
#define MEMBEROF_PREFIX "MEMBEROF/"

/****************************************************************************
initialise first time the mapping list - called from init_group_mapping()
****************************************************************************/
static BOOL default_group_mapping(void)
{
	DOM_SID sid_admins;
	DOM_SID sid_users;
	DOM_SID sid_guests;
	fstring str_admins;
	fstring str_users;
	fstring str_guests;

	/* Add the Wellknown groups */

	add_initial_entry(-1, "S-1-5-32-544", SID_NAME_WKN_GRP, "Administrators", "");
	add_initial_entry(-1, "S-1-5-32-545", SID_NAME_WKN_GRP, "Users", "");
	add_initial_entry(-1, "S-1-5-32-546", SID_NAME_WKN_GRP, "Guests", "");
	add_initial_entry(-1, "S-1-5-32-547", SID_NAME_WKN_GRP, "Power Users", "");
	add_initial_entry(-1, "S-1-5-32-548", SID_NAME_WKN_GRP, "Account Operators", "");
	add_initial_entry(-1, "S-1-5-32-549", SID_NAME_WKN_GRP, "System Operators", "");
	add_initial_entry(-1, "S-1-5-32-550", SID_NAME_WKN_GRP, "Print Operators", "");
	add_initial_entry(-1, "S-1-5-32-551", SID_NAME_WKN_GRP, "Backup Operators", "");
	add_initial_entry(-1, "S-1-5-32-552", SID_NAME_WKN_GRP, "Replicators", "");

	/* Add the defaults domain groups */

	sid_copy(&sid_admins, get_global_sam_sid());
	sid_append_rid(&sid_admins, DOMAIN_GROUP_RID_ADMINS);
	sid_to_string(str_admins, &sid_admins);
	add_initial_entry(-1, str_admins, SID_NAME_DOM_GRP, "Domain Admins", "");

	sid_copy(&sid_users,  get_global_sam_sid());
	sid_append_rid(&sid_users,  DOMAIN_GROUP_RID_USERS);
	sid_to_string(str_users, &sid_users);
	add_initial_entry(-1, str_users,  SID_NAME_DOM_GRP, "Domain Users",  "");

	sid_copy(&sid_guests, get_global_sam_sid());
	sid_append_rid(&sid_guests, DOMAIN_GROUP_RID_GUESTS);
	sid_to_string(str_guests, &sid_guests);
	add_initial_entry(-1, str_guests, SID_NAME_DOM_GRP, "Domain Guests", "");

	return True;
}

/****************************************************************************
 Open the group mapping tdb.
****************************************************************************/

static BOOL init_group_mapping(void)
{
	const char *vstring = "INFO/version";
	int32 vers_id;
	
	if (tdb)
		return True;
	tdb = tdb_open_log(lock_path("group_mapping.tdb"), 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
	if (!tdb) {
		DEBUG(0,("Failed to open group mapping database\n"));
		return False;
	}

	/* handle a Samba upgrade */
	tdb_lock_bystring(tdb, vstring, 0);

	/* Cope with byte-reversed older versions of the db. */
	vers_id = tdb_fetch_int32(tdb, vstring);
	if ((vers_id == DATABASE_VERSION_V1) || (IREV(vers_id) == DATABASE_VERSION_V1)) {
		/* Written on a bigendian machine with old fetch_int code. Save as le. */
		tdb_store_int32(tdb, vstring, DATABASE_VERSION_V2);
		vers_id = DATABASE_VERSION_V2;
	}

	if (vers_id != DATABASE_VERSION_V2) {
		tdb_traverse(tdb, tdb_traverse_delete_fn, NULL);
		tdb_store_int32(tdb, vstring, DATABASE_VERSION_V2);
	}

	tdb_unlock_bystring(tdb, vstring);

	/* write a list of default groups */
	if(!default_group_mapping())
		return False;

	return True;
}

/****************************************************************************
****************************************************************************/
static BOOL add_mapping_entry(GROUP_MAP *map, int flag)
{
	TDB_DATA kbuf, dbuf;
	pstring key, buf;
	fstring string_sid="";
	int len;

	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return(False);
	}
	
	sid_to_string(string_sid, &map->sid);

	len = tdb_pack(buf, sizeof(buf), "ddff",
			map->gid, map->sid_name_use, map->nt_name, map->comment);

	if (len > sizeof(buf))
		return False;

	slprintf(key, sizeof(key), "%s%s", GROUP_PREFIX, string_sid);

	kbuf.dsize = strlen(key)+1;
	kbuf.dptr = key;
	dbuf.dsize = len;
	dbuf.dptr = buf;
	if (tdb_store(tdb, kbuf, dbuf, flag) != 0) return False;

	return True;
}

/****************************************************************************
initialise first time the mapping list
****************************************************************************/
NTSTATUS add_initial_entry(gid_t gid, const char *sid, enum SID_NAME_USE sid_name_use, const char *nt_name, const char *comment)
{
	GROUP_MAP map;

	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return NT_STATUS_UNSUCCESSFUL;
	}
	
	map.gid=gid;
	if (!string_to_sid(&map.sid, sid)) {
		DEBUG(0, ("string_to_sid failed: %s", sid));
		return NT_STATUS_UNSUCCESSFUL;
	}
	
	map.sid_name_use=sid_name_use;
	fstrcpy(map.nt_name, nt_name);
	fstrcpy(map.comment, comment);

	return pdb_add_group_mapping_entry(&map);
}

/****************************************************************************
 Map a unix group to a newly created mapping
****************************************************************************/
NTSTATUS map_unix_group(const struct group *grp, GROUP_MAP *pmap)
{
	NTSTATUS status;
	GROUP_MAP map;
	const char *grpname, *dom, *name;
	uint32 rid;

	if (pdb_getgrgid(&map, grp->gr_gid)) {
		return NT_STATUS_GROUP_EXISTS;
	}

	map.gid = grp->gr_gid;
	grpname = grp->gr_name;

	if (lookup_name(tmp_talloc_ctx(), grpname, LOOKUP_NAME_ISOLATED,
			&dom, &name, NULL, NULL)) {

		const char *tmp = talloc_asprintf(
			tmp_talloc_ctx(), "Unix Group %s", grp->gr_name);

		DEBUG(5, ("%s exists as %s\\%s, retrying as \"%s\"\n",
			  grpname, dom, name, tmp));
		grpname = tmp;
	}

	if (lookup_name(tmp_talloc_ctx(), grpname, LOOKUP_NAME_ISOLATED,
			NULL, NULL, NULL, NULL)) {
		DEBUG(3, ("\"%s\" exists, can't map it\n", grp->gr_name));
		return NT_STATUS_GROUP_EXISTS;
	}

	fstrcpy(map.nt_name, grpname);

	if (pdb_rid_algorithm()) {
		rid = pdb_gid_to_group_rid( grp->gr_gid );
	} else {
		if (!pdb_new_rid(&rid)) {
			DEBUG(3, ("Could not get a new RID for %s\n",
				  grp->gr_name));
			return NT_STATUS_ACCESS_DENIED;
		}
	}

	sid_compose(&map.sid, get_global_sam_sid(), rid);
	map.sid_name_use = SID_NAME_DOM_GRP;
	fstrcpy(map.comment, talloc_asprintf(tmp_talloc_ctx(), "Unix Group %s",
					     grp->gr_name));

	status = pdb_add_group_mapping_entry(&map);
	if (NT_STATUS_IS_OK(status)) {
		*pmap = map;
	}
	return status;
}

/****************************************************************************
 Return the sid and the type of the unix group.
****************************************************************************/

static BOOL get_group_map_from_sid(DOM_SID sid, GROUP_MAP *map)
{
	TDB_DATA kbuf, dbuf;
	pstring key;
	fstring string_sid;
	int ret = 0;
	
	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return(False);
	}

	/* the key is the SID, retrieving is direct */

	sid_to_string(string_sid, &sid);
	slprintf(key, sizeof(key), "%s%s", GROUP_PREFIX, string_sid);

	kbuf.dptr = key;
	kbuf.dsize = strlen(key)+1;
		
	dbuf = tdb_fetch(tdb, kbuf);
	if (!dbuf.dptr)
		return False;

	ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
				&map->gid, &map->sid_name_use, &map->nt_name, &map->comment);

	SAFE_FREE(dbuf.dptr);
	
	if ( ret == -1 ) {
		DEBUG(3,("get_group_map_from_sid: tdb_unpack failure\n"));
		return False;
	}

	sid_copy(&map->sid, &sid);
	
	return True;
}

/****************************************************************************
 Return the sid and the type of the unix group.
****************************************************************************/

static BOOL get_group_map_from_gid(gid_t gid, GROUP_MAP *map)
{
	TDB_DATA kbuf, dbuf, newkey;
	fstring string_sid;
	int ret;

	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return(False);
	}

	/* we need to enumerate the TDB to find the GID */

	for (kbuf = tdb_firstkey(tdb); 
	     kbuf.dptr; 
	     newkey = tdb_nextkey(tdb, kbuf), safe_free(kbuf.dptr), kbuf=newkey) {

		if (strncmp(kbuf.dptr, GROUP_PREFIX, strlen(GROUP_PREFIX)) != 0) continue;
		
		dbuf = tdb_fetch(tdb, kbuf);
		if (!dbuf.dptr)
			continue;

		fstrcpy(string_sid, kbuf.dptr+strlen(GROUP_PREFIX));

		string_to_sid(&map->sid, string_sid);
		
		ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
				 &map->gid, &map->sid_name_use, &map->nt_name, &map->comment);

		SAFE_FREE(dbuf.dptr);

		if ( ret == -1 ) {
			DEBUG(3,("get_group_map_from_gid: tdb_unpack failure\n"));
			return False;
		}
	
		if (gid==map->gid) {
			SAFE_FREE(kbuf.dptr);
			return True;
		}
	}

	return False;
}

/****************************************************************************
 Return the sid and the type of the unix group.
****************************************************************************/

static BOOL get_group_map_from_ntname(const char *name, GROUP_MAP *map)
{
	TDB_DATA kbuf, dbuf, newkey;
	fstring string_sid;
	int ret;

	if(!init_group_mapping()) {
		DEBUG(0,("get_group_map_from_ntname:failed to initialize group mapping\n"));
		return(False);
	}

	/* we need to enumerate the TDB to find the name */

	for (kbuf = tdb_firstkey(tdb); 
	     kbuf.dptr; 
	     newkey = tdb_nextkey(tdb, kbuf), safe_free(kbuf.dptr), kbuf=newkey) {

		if (strncmp(kbuf.dptr, GROUP_PREFIX, strlen(GROUP_PREFIX)) != 0) continue;
		
		dbuf = tdb_fetch(tdb, kbuf);
		if (!dbuf.dptr)
			continue;

		fstrcpy(string_sid, kbuf.dptr+strlen(GROUP_PREFIX));

		string_to_sid(&map->sid, string_sid);
		
		ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
				 &map->gid, &map->sid_name_use, &map->nt_name, &map->comment);

		SAFE_FREE(dbuf.dptr);
		
		if ( ret == -1 ) {
			DEBUG(3,("get_group_map_from_ntname: tdb_unpack failure\n"));
			return False;
		}

		if (StrCaseCmp(name, map->nt_name)==0) {
			SAFE_FREE(kbuf.dptr);
			return True;
		}
	}

	return False;
}

/****************************************************************************
 Remove a group mapping entry.
****************************************************************************/

static BOOL group_map_remove(const DOM_SID *sid)
{
	TDB_DATA kbuf, dbuf;
	pstring key;
	fstring string_sid;
	
	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return(False);
	}

	/* the key is the SID, retrieving is direct */

	sid_to_string(string_sid, sid);
	slprintf(key, sizeof(key), "%s%s", GROUP_PREFIX, string_sid);

	kbuf.dptr = key;
	kbuf.dsize = strlen(key)+1;
		
	dbuf = tdb_fetch(tdb, kbuf);
	if (!dbuf.dptr)
		return False;
	
	SAFE_FREE(dbuf.dptr);

	if(tdb_delete(tdb, kbuf) != TDB_SUCCESS)
		return False;

	return True;
}

/****************************************************************************
 Enumerate the group mapping.
****************************************************************************/

static BOOL enum_group_mapping(enum SID_NAME_USE sid_name_use, GROUP_MAP **pp_rmap,
			size_t *p_num_entries, BOOL unix_only)
{
	TDB_DATA kbuf, dbuf, newkey;
	fstring string_sid;
	GROUP_MAP map;
	GROUP_MAP *mapt;
	int ret;
	size_t entries=0;

	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return(False);
	}

	*p_num_entries=0;
	*pp_rmap=NULL;

	for (kbuf = tdb_firstkey(tdb); 
	     kbuf.dptr; 
	     newkey = tdb_nextkey(tdb, kbuf), safe_free(kbuf.dptr), kbuf=newkey) {

		if (strncmp(kbuf.dptr, GROUP_PREFIX, strlen(GROUP_PREFIX)) != 0)
			continue;

		dbuf = tdb_fetch(tdb, kbuf);
		if (!dbuf.dptr)
			continue;

		fstrcpy(string_sid, kbuf.dptr+strlen(GROUP_PREFIX));
				
		ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
				 &map.gid, &map.sid_name_use, &map.nt_name, &map.comment);

		SAFE_FREE(dbuf.dptr);

		if ( ret == -1 ) {
			DEBUG(3,("enum_group_mapping: tdb_unpack failure\n"));
			continue;
		}
	
		/* list only the type or everything if UNKNOWN */
		if (sid_name_use!=SID_NAME_UNKNOWN  && sid_name_use!=map.sid_name_use) {
			DEBUG(11,("enum_group_mapping: group %s is not of the requested type\n", map.nt_name));
			continue;
		}

		if (unix_only==ENUM_ONLY_MAPPED && map.gid==-1) {
			DEBUG(11,("enum_group_mapping: group %s is non mapped\n", map.nt_name));
			continue;
		}

		string_to_sid(&map.sid, string_sid);
		
		DEBUG(11,("enum_group_mapping: returning group %s of "
			  "type %s\n", map.nt_name,
			  sid_type_lookup(map.sid_name_use)));

		mapt= SMB_REALLOC_ARRAY((*pp_rmap), GROUP_MAP, entries+1);
		if (!mapt) {
			DEBUG(0,("enum_group_mapping: Unable to enlarge group map!\n"));
			SAFE_FREE(*pp_rmap);
			return False;
		}
		else
			(*pp_rmap) = mapt;

		mapt[entries].gid = map.gid;
		sid_copy( &mapt[entries].sid, &map.sid);
		mapt[entries].sid_name_use = map.sid_name_use;
		fstrcpy(mapt[entries].nt_name, map.nt_name);
		fstrcpy(mapt[entries].comment, map.comment);

		entries++;

	}

	*p_num_entries=entries;

	return True;
}

/* This operation happens on session setup, so it should better be fast. We
 * store a list of aliases a SID is member of hanging off MEMBEROF/SID. */

static NTSTATUS one_alias_membership(const DOM_SID *member,
				     DOM_SID **sids, size_t *num)
{
	fstring key, string_sid;
	TDB_DATA kbuf, dbuf;
	const char *p;

	if (!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	sid_to_string(string_sid, member);
	slprintf(key, sizeof(key), "%s%s", MEMBEROF_PREFIX, string_sid);

	kbuf.dsize = strlen(key)+1;
	kbuf.dptr = key;

	dbuf = tdb_fetch(tdb, kbuf);

	if (dbuf.dptr == NULL) {
		return NT_STATUS_OK;
	}

	p = dbuf.dptr;

	while (next_token(&p, string_sid, " ", sizeof(string_sid))) {

		DOM_SID alias;

		if (!string_to_sid(&alias, string_sid))
			continue;

		add_sid_to_array_unique(NULL, &alias, sids, num);

		if (sids == NULL)
			return NT_STATUS_NO_MEMORY;
	}

	SAFE_FREE(dbuf.dptr);
	return NT_STATUS_OK;
}

static NTSTATUS alias_memberships(const DOM_SID *members, size_t num_members,
				  DOM_SID **sids, size_t *num)
{
	size_t i;

	*num = 0;
	*sids = NULL;

	for (i=0; i<num_members; i++) {
		NTSTATUS status = one_alias_membership(&members[i], sids, num);
		if (!NT_STATUS_IS_OK(status))
			return status;
	}
	return NT_STATUS_OK;
}

static BOOL is_aliasmem(const DOM_SID *alias, const DOM_SID *member)
{
	DOM_SID *sids;
	size_t i, num;

	/* This feels the wrong way round, but the on-disk data structure
	 * dictates it this way. */
	if (!NT_STATUS_IS_OK(alias_memberships(member, 1, &sids, &num)))
		return False;

	for (i=0; i<num; i++) {
		if (sid_compare(alias, &sids[i]) == 0) {
			SAFE_FREE(sids);
			return True;
		}
	}
	SAFE_FREE(sids);
	return False;
}

static NTSTATUS add_aliasmem(const DOM_SID *alias, const DOM_SID *member)
{
	GROUP_MAP map;
	TDB_DATA kbuf, dbuf;
	pstring key;
	fstring string_sid;
	char *new_memberstring;
	int result;

	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (!get_group_map_from_sid(*alias, &map))
		return NT_STATUS_NO_SUCH_ALIAS;

	if ( (map.sid_name_use != SID_NAME_ALIAS) &&
	     (map.sid_name_use != SID_NAME_WKN_GRP) )
		return NT_STATUS_NO_SUCH_ALIAS;

	if (is_aliasmem(alias, member))
		return NT_STATUS_MEMBER_IN_ALIAS;

	sid_to_string(string_sid, member);
	slprintf(key, sizeof(key), "%s%s", MEMBEROF_PREFIX, string_sid);

	kbuf.dsize = strlen(key)+1;
	kbuf.dptr = key;

	dbuf = tdb_fetch(tdb, kbuf);

	sid_to_string(string_sid, alias);

	if (dbuf.dptr != NULL) {
		asprintf(&new_memberstring, "%s %s", (char *)(dbuf.dptr),
			 string_sid);
	} else {
		new_memberstring = SMB_STRDUP(string_sid);
	}

	if (new_memberstring == NULL)
		return NT_STATUS_NO_MEMORY;

	SAFE_FREE(dbuf.dptr);
	dbuf.dsize = strlen(new_memberstring)+1;
	dbuf.dptr = new_memberstring;

	result = tdb_store(tdb, kbuf, dbuf, 0);

	SAFE_FREE(new_memberstring);

	return (result == 0 ? NT_STATUS_OK : NT_STATUS_ACCESS_DENIED);
}

struct aliasmem_closure {
	const DOM_SID *alias;
	DOM_SID **sids;
	size_t *num;
};

static int collect_aliasmem(TDB_CONTEXT *tdb_ctx, TDB_DATA key, TDB_DATA data,
			    void *state)
{
	struct aliasmem_closure *closure = (struct aliasmem_closure *)state;
	const char *p;
	fstring alias_string;

	if (strncmp(key.dptr, MEMBEROF_PREFIX,
		    strlen(MEMBEROF_PREFIX)) != 0)
		return 0;

	p = data.dptr;

	while (next_token(&p, alias_string, " ", sizeof(alias_string))) {

		DOM_SID alias, member;
		const char *member_string;
		

		if (!string_to_sid(&alias, alias_string))
			continue;

		if (sid_compare(closure->alias, &alias) != 0)
			continue;

		/* Ok, we found the alias we're looking for in the membership
		 * list currently scanned. The key represents the alias
		 * member. Add that. */

		member_string = strchr(key.dptr, '/');

		/* Above we tested for MEMBEROF_PREFIX which includes the
		 * slash. */

		SMB_ASSERT(member_string != NULL);
		member_string += 1;

		if (!string_to_sid(&member, member_string))
			continue;
		
		add_sid_to_array(NULL, &member, closure->sids, closure->num);
	}

	return 0;
}

static NTSTATUS enum_aliasmem(const DOM_SID *alias, DOM_SID **sids, size_t *num)
{
	GROUP_MAP map;
	struct aliasmem_closure closure;

	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (!get_group_map_from_sid(*alias, &map))
		return NT_STATUS_NO_SUCH_ALIAS;

	if ( (map.sid_name_use != SID_NAME_ALIAS) &&
	     (map.sid_name_use != SID_NAME_WKN_GRP) )
		return NT_STATUS_NO_SUCH_ALIAS;

	*sids = NULL;
	*num = 0;

	closure.alias = alias;
	closure.sids = sids;
	closure.num = num;

	tdb_traverse(tdb, collect_aliasmem, &closure);
	return NT_STATUS_OK;
}

static NTSTATUS del_aliasmem(const DOM_SID *alias, const DOM_SID *member)
{
	NTSTATUS result;
	DOM_SID *sids;
	size_t i, num;
	BOOL found = False;
	char *member_string;
	TDB_DATA kbuf, dbuf;
	pstring key;
	fstring sid_string;

	result = alias_memberships(member, 1, &sids, &num);

	if (!NT_STATUS_IS_OK(result))
		return result;

	for (i=0; i<num; i++) {
		if (sid_compare(&sids[i], alias) == 0) {
			found = True;
			break;
		}
	}

	if (!found) {
		SAFE_FREE(sids);
		return NT_STATUS_MEMBER_NOT_IN_ALIAS;
	}

	if (i < num)
		sids[i] = sids[num-1];

	num -= 1;

	sid_to_string(sid_string, member);
	slprintf(key, sizeof(key), "%s%s", MEMBEROF_PREFIX, sid_string);

	kbuf.dsize = strlen(key)+1;
	kbuf.dptr = key;

	if (num == 0)
		return tdb_delete(tdb, kbuf) == 0 ?
			NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;

	member_string = SMB_STRDUP("");

	if (member_string == NULL) {
		SAFE_FREE(sids);
		return NT_STATUS_NO_MEMORY;
	}

	for (i=0; i<num; i++) {
		char *s = member_string;

		sid_to_string(sid_string, &sids[i]);
		asprintf(&member_string, "%s %s", s, sid_string);

		SAFE_FREE(s);
		if (member_string == NULL) {
			SAFE_FREE(sids);
			return NT_STATUS_NO_MEMORY;
		}
	}

	dbuf.dsize = strlen(member_string)+1;
	dbuf.dptr = member_string;

	result = tdb_store(tdb, kbuf, dbuf, 0) == 0 ?
		NT_STATUS_OK : NT_STATUS_ACCESS_DENIED;

	SAFE_FREE(sids);
	SAFE_FREE(member_string);

	return result;
}

/*
 *
 * High level functions
 * better to use them than the lower ones.
 *
 * we are checking if the group is in the mapping file
 * and if the group is an existing unix group
 *
 */

/* get a domain group from it's SID */

BOOL get_domain_group_from_sid(DOM_SID sid, GROUP_MAP *map)
{
	struct group *grp;
	BOOL ret;
	
	if(!init_group_mapping()) {
		DEBUG(0,("failed to initialize group mapping\n"));
		return(False);
	}

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

	/* if the group is NOT in the database, it CAN NOT be a domain group */
	
	become_root();
	ret = pdb_getgrsid(map, sid);
	unbecome_root();
	
	if ( !ret ) 
		return False;

	DEBUG(10, ("get_domain_group_from_sid: SID found in the TDB\n"));

	/* if it's not a domain group, continue */
	if (map->sid_name_use!=SID_NAME_DOM_GRP) {
		return False;
	}

	DEBUG(10, ("get_domain_group_from_sid: SID is a domain group\n"));
 	
	if (map->gid==-1) {
		return False;
	}

	DEBUG(10, ("get_domain_group_from_sid: SID is mapped to gid:%lu\n",(unsigned long)map->gid));
	
	grp = getgrgid(map->gid);
	if ( !grp ) {
		DEBUG(10, ("get_domain_group_from_sid: gid DOESN'T exist in UNIX security\n"));
		return False;
	}

	DEBUG(10, ("get_domain_group_from_sid: gid exists in UNIX security\n"));

	return True;
}

/****************************************************************************
 Create a UNIX group on demand.
****************************************************************************/

int smb_create_group(const char *unix_group, gid_t *new_gid)
{
	pstring add_script;
	int 	ret = -1;
	int 	fd = 0;
	
	*new_gid = 0;

	/* defer to scripts */
	
	if ( *lp_addgroup_script() ) {
		pstrcpy(add_script, lp_addgroup_script());
		pstring_sub(add_script, "%g", unix_group);
		ret = smbrun(add_script, (new_gid!=NULL) ? &fd : NULL);
		DEBUG(ret ? 0 : 3,("smb_create_group: Running the command `%s' gave %d\n",add_script,ret));
		if (ret != 0)
			return ret;
			
		if (fd != 0) {
			fstring output;

			*new_gid = 0;
			if (read(fd, output, sizeof(output)) > 0) {
				*new_gid = (gid_t)strtoul(output, NULL, 10);
			}
			
			close(fd);
		}

	}

	if (*new_gid == 0) {
		struct group *grp = getgrnam(unix_group);

		if (grp != NULL)
			*new_gid = grp->gr_gid;
	}
			
	return ret;	
}

/****************************************************************************
 Delete a UNIX group on demand.
****************************************************************************/

int smb_delete_group(const char *unix_group)
{
	pstring del_script;
	int ret;

	/* defer to scripts */
	
	if ( *lp_delgroup_script() ) {
		pstrcpy(del_script, lp_delgroup_script());
		pstring_sub(del_script, "%g", unix_group);
		ret = smbrun(del_script,NULL);
		DEBUG(ret ? 0 : 3,("smb_delete_group: Running the command `%s' gave %d\n",del_script,ret));
		return ret;
	}
		
	return -1;
}

/****************************************************************************
 Set a user's primary UNIX group.
****************************************************************************/
int smb_set_primary_group(const char *unix_group, const char* unix_user)
{
	pstring add_script;
	int ret;

	/* defer to scripts */
	
	if ( *lp_setprimarygroup_script() ) {
		pstrcpy(add_script, lp_setprimarygroup_script());
		all_string_sub(add_script, "%g", unix_group, sizeof(add_script));
		all_string_sub(add_script, "%u", unix_user, sizeof(add_script));
		ret = smbrun(add_script,NULL);
		flush_pwnam_cache();
		DEBUG(ret ? 0 : 3,("smb_set_primary_group: "
			 "Running the command `%s' gave %d\n",add_script,ret));
		return ret;
	}

	return -1;
}

/****************************************************************************
 Add a user to a UNIX group.
****************************************************************************/

int smb_add_user_group(const char *unix_group, const char *unix_user)
{
	pstring add_script;
	int ret;

	/* defer to scripts */
	
	if ( *lp_addusertogroup_script() ) {
		pstrcpy(add_script, lp_addusertogroup_script());
		pstring_sub(add_script, "%g", unix_group);
		pstring_sub(add_script, "%u", unix_user);
		ret = smbrun(add_script,NULL);
		DEBUG(ret ? 0 : 3,("smb_add_user_group: Running the command `%s' gave %d\n",add_script,ret));
		return ret;
	}
	
	return -1;
}

/****************************************************************************
 Delete a user from a UNIX group
****************************************************************************/

int smb_delete_user_group(const char *unix_group, const char *unix_user)
{
	pstring del_script;
	int ret;

	/* defer to scripts */
	
	if ( *lp_deluserfromgroup_script() ) {
		pstrcpy(del_script, lp_deluserfromgroup_script());
		pstring_sub(del_script, "%g", unix_group);
		pstring_sub(del_script, "%u", unix_user);
		ret = smbrun(del_script,NULL);
		DEBUG(ret ? 0 : 3,("smb_delete_user_group: Running the command `%s' gave %d\n",del_script,ret));
		return ret;
	}
	
	return -1;
}


NTSTATUS pdb_default_getgrsid(struct pdb_methods *methods, GROUP_MAP *map,
				 DOM_SID sid)
{
	return get_group_map_from_sid(sid, map) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_getgrgid(struct pdb_methods *methods, GROUP_MAP *map,
				 gid_t gid)
{
	return get_group_map_from_gid(gid, map) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_getgrnam(struct pdb_methods *methods, GROUP_MAP *map,
				 const char *name)
{
	return get_group_map_from_ntname(name, map) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_add_group_mapping_entry(struct pdb_methods *methods,
						GROUP_MAP *map)
{
	return add_mapping_entry(map, TDB_INSERT) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_update_group_mapping_entry(struct pdb_methods *methods,
						   GROUP_MAP *map)
{
	return add_mapping_entry(map, TDB_REPLACE) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_delete_group_mapping_entry(struct pdb_methods *methods,
						   DOM_SID sid)
{
	return group_map_remove(&sid) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_enum_group_mapping(struct pdb_methods *methods,
					   enum SID_NAME_USE sid_name_use,
					   GROUP_MAP **pp_rmap, size_t *p_num_entries,
					   BOOL unix_only)
{
	return enum_group_mapping(sid_name_use, pp_rmap, p_num_entries, unix_only) ?
		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_default_find_alias(struct pdb_methods *methods,
				const char *name, DOM_SID *sid)
{
	GROUP_MAP map;

	if (!pdb_getgrnam(&map, name))
		return NT_STATUS_NO_SUCH_ALIAS;

	if ((map.sid_name_use != SID_NAME_WKN_GRP) &&
	    (map.sid_name_use != SID_NAME_ALIAS))
		return NT_STATUS_OBJECT_TYPE_MISMATCH;

	sid_copy(sid, &map.sid);
	return NT_STATUS_OK;
}

NTSTATUS pdb_default_create_alias(struct pdb_methods *methods,
				  const char *name, uint32 *rid)
{
	DOM_SID sid;
	enum SID_NAME_USE type;
	uint32 new_rid;
	gid_t gid;
	BOOL exists;
	GROUP_MAP map;
	TALLOC_CTX *mem_ctx;
	NTSTATUS status;

	DEBUG(10, ("Trying to create alias %s\n", name));

	mem_ctx = talloc_new(NULL);
	if (mem_ctx == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	exists = lookup_name(mem_ctx, name, LOOKUP_NAME_ISOLATED,
			     NULL, NULL, &sid, &type);
	talloc_free(mem_ctx);

	if (exists) {
		return NT_STATUS_ALIAS_EXISTS;
	}

	if (!winbind_allocate_gid(&gid)) {
		DEBUG(3, ("Could not get a gid out of winbind\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (!pdb_new_rid(&new_rid)) {
		DEBUG(0, ("Could not allocate a RID -- wasted a gid :-(\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	DEBUG(10, ("Creating alias %s with gid %d and rid %d\n",
		   name, gid, new_rid));

	sid_copy(&sid, get_global_sam_sid());
	sid_append_rid(&sid, new_rid);

	map.gid = gid;
	sid_copy(&map.sid, &sid);
	map.sid_name_use = SID_NAME_ALIAS;
	fstrcpy(map.nt_name, name);
	fstrcpy(map.comment, "");

	status = pdb_add_group_mapping_entry(&map);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Could not add group mapping entry for alias %s "
			  "(%s)\n", name, nt_errstr(status)));
		return status;
	}

	*rid = new_rid;

	return NT_STATUS_OK;
}

NTSTATUS pdb_default_delete_alias(struct pdb_methods *methods,
				  const DOM_SID *sid)
{
	return pdb_delete_group_mapping_entry(*sid);
}

NTSTATUS pdb_default_get_aliasinfo(struct pdb_methods *methods,
				   const DOM_SID *sid,
				   struct acct_info *info)
{
	GROUP_MAP map;

	if (!pdb_getgrsid(&map, *sid))
		return NT_STATUS_NO_SUCH_ALIAS;

	if ((map.sid_name_use != SID_NAME_ALIAS) &&
	    (map.sid_name_use != SID_NAME_WKN_GRP)) {
		DEBUG(2, ("%s is a %s, expected an alias\n",
			  sid_string_static(sid),
			  sid_type_lookup(map.sid_name_use)));
		return NT_STATUS_NO_SUCH_ALIAS;
	}

	fstrcpy(info->acct_name, map.nt_name);
	fstrcpy(info->acct_desc, map.comment);
	sid_peek_rid(&map.sid, &info->rid);
	return NT_STATUS_OK;
}

NTSTATUS pdb_default_set_aliasinfo(struct pdb_methods *methods,
				   const DOM_SID *sid,
				   struct acct_info *info)
{
	GROUP_MAP map;

	if (!pdb_getgrsid(&map, *sid))
		return NT_STATUS_NO_SUCH_ALIAS;

	fstrcpy(map.comment, info->acct_desc);

	return pdb_update_group_mapping_entry(&map);
}

NTSTATUS pdb_default_add_aliasmem(struct pdb_methods *methods,
				  const DOM_SID *alias, const DOM_SID *member)
{
	return add_aliasmem(alias, member);
}

NTSTATUS pdb_default_del_aliasmem(struct pdb_methods *methods,
				  const DOM_SID *alias, const DOM_SID *member)
{
	return del_aliasmem(alias, member);
}

NTSTATUS pdb_default_enum_aliasmem(struct pdb_methods *methods,
				   const DOM_SID *alias, DOM_SID **pp_members,
				   size_t *p_num_members)
{
	return enum_aliasmem(alias, pp_members, p_num_members);
}

NTSTATUS pdb_default_alias_memberships(struct pdb_methods *methods,
				       TALLOC_CTX *mem_ctx,
				       const DOM_SID *domain_sid,
				       const DOM_SID *members,
				       size_t num_members,
				       uint32 **pp_alias_rids,
				       size_t *p_num_alias_rids)
{
	DOM_SID *alias_sids;
	size_t i, num_alias_sids;
	NTSTATUS result;

	alias_sids = NULL;
	num_alias_sids = 0;

	result = alias_memberships(members, num_members,
				   &alias_sids, &num_alias_sids);

	if (!NT_STATUS_IS_OK(result))
		return result;

	*pp_alias_rids = TALLOC_ARRAY(mem_ctx, uint32, num_alias_sids);
	if (*pp_alias_rids == NULL)
		return NT_STATUS_NO_MEMORY;

	*p_num_alias_rids = 0;

	for (i=0; i<num_alias_sids; i++) {
		if (!sid_peek_check_rid(domain_sid, &alias_sids[i],
					&(*pp_alias_rids)[*p_num_alias_rids]))
			continue;
		*p_num_alias_rids += 1;
	}

	SAFE_FREE(alias_sids);

	return NT_STATUS_OK;
}

/**********************************************************************
 no ops for passdb backends that don't implement group mapping
 *********************************************************************/

NTSTATUS pdb_nop_getgrsid(struct pdb_methods *methods, GROUP_MAP *map,
				 DOM_SID sid)
{
	return NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_nop_getgrgid(struct pdb_methods *methods, GROUP_MAP *map,
				 gid_t gid)
{
	return NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_nop_getgrnam(struct pdb_methods *methods, GROUP_MAP *map,
				 const char *name)
{
	return NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_nop_add_group_mapping_entry(struct pdb_methods *methods,
						GROUP_MAP *map)
{
	return NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_nop_update_group_mapping_entry(struct pdb_methods *methods,
						   GROUP_MAP *map)
{
	return NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_nop_delete_group_mapping_entry(struct pdb_methods *methods,
						   DOM_SID sid)
{
	return NT_STATUS_UNSUCCESSFUL;
}

NTSTATUS pdb_nop_enum_group_mapping(struct pdb_methods *methods,
					   enum SID_NAME_USE sid_name_use,
					   GROUP_MAP **rmap, size_t *num_entries,
					   BOOL unix_only)
{
	return NT_STATUS_UNSUCCESSFUL;
}

/****************************************************************************
 These need to be redirected through pdb_interface.c
****************************************************************************/
BOOL pdb_get_dom_grp_info(const DOM_SID *sid, struct acct_info *info)
{
	GROUP_MAP map;
	BOOL res;

	become_root();
	res = get_domain_group_from_sid(*sid, &map);
	unbecome_root();

	if (!res)
		return False;

	fstrcpy(info->acct_name, map.nt_name);
	fstrcpy(info->acct_desc, map.comment);
	sid_peek_rid(sid, &info->rid);
	return True;
}

BOOL pdb_set_dom_grp_info(const DOM_SID *sid, const struct acct_info *info)
{
	GROUP_MAP map;

	if (!get_domain_group_from_sid(*sid, &map))
		return False;

	fstrcpy(map.nt_name, info->acct_name);
	fstrcpy(map.comment, info->acct_desc);

	return NT_STATUS_IS_OK(pdb_update_group_mapping_entry(&map));
}