idmap_tdb.c

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/* 
   Unix SMB/CIFS implementation.

   idmap TDB backend

   Copyright (C) Tim Potter 2000
   Copyright (C) Jim McDonough <[e-mail]> 2003
   Copyright (C) Simo Sorce 2003
   
   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"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_IDMAP

/* High water mark keys */
#define HWM_GROUP  "GROUP HWM"
#define HWM_USER   "USER HWM"

/* idmap version determines auto-conversion */
#define IDMAP_VERSION 2

/* Globals */
static TDB_CONTEXT *idmap_tdb;

static struct idmap_state {

	/* User and group id pool */

	uid_t uid_low, uid_high;               /* Range of uids to allocate */
	gid_t gid_low, gid_high;               /* Range of gids to allocate */
} idmap_state;

/**********************************************************************
 allocate a new RID; We don't care if is a user or group
**********************************************************************/

static NTSTATUS db_allocate_rid(uint32 *rid, int rid_type)
{
	uint32 lowrid, highrid;
	uint32 tmp_rid;

	/* can't handle group rids right now.  This is such a mess.... */

	if ( rid_type == GROUP_RID_TYPE )
		return NT_STATUS_UNSUCCESSFUL;
	
	/* cannot fail since idmap is only called winbindd */
	
	get_free_rid_range( &lowrid, &highrid );
	
	tmp_rid = lowrid;
	
	if ( !tdb_change_uint32_atomic(idmap_tdb, "RID_COUNTER", &tmp_rid, RID_MULTIPLIER) ) {
		DEBUG(3,("db_allocate_rid: Failed to locate next rid record in idmap db\n"));
		return NT_STATUS_UNSUCCESSFUL;
	}
	
	if ( tmp_rid > highrid ) {
		DEBUG(0, ("db_allocate_rid: no RIDs available!\n"));
		return NT_STATUS_UNSUCCESSFUL;
	}
	
	*rid = tmp_rid;

	return NT_STATUS_OK;
}

/**********************************************************************
 Allocate either a user or group id from the pool 
**********************************************************************/
 
static NTSTATUS db_allocate_id(unid_t *id, int id_type)
{
	BOOL ret;
	int hwm;

	if (!id)
		return NT_STATUS_INVALID_PARAMETER;

	/* Get current high water mark */
	switch (id_type & ID_TYPEMASK) {
		case ID_USERID:

			if ((hwm = tdb_fetch_int32(idmap_tdb, HWM_USER)) == -1) {
				return NT_STATUS_INTERNAL_DB_ERROR;
			}

			/* check it is in the range */
			if (hwm > idmap_state.uid_high) {
				DEBUG(0, ("idmap Fatal Error: UID range full!! (max: %lu)\n", 
					  (unsigned long)idmap_state.uid_high));
				return NT_STATUS_UNSUCCESSFUL;
			}

			/* fetch a new id and increment it */
			ret = tdb_change_uint32_atomic(idmap_tdb, HWM_USER, (unsigned int *)&hwm, 1);
			if (!ret) {
				DEBUG(0, ("idmap_tdb: Fatal error while fetching a new id\n!"));
				return NT_STATUS_UNSUCCESSFUL;
			}

			/* recheck it is in the range */
			if (hwm > idmap_state.uid_high) {
				DEBUG(0, ("idmap Fatal Error: UID range full!! (max: %lu)\n", 
					  (unsigned long)idmap_state.uid_high));
				return NT_STATUS_UNSUCCESSFUL;
			}
			
			(*id).uid = hwm;
			DEBUG(10,("db_allocate_id: ID_USERID (*id).uid = %d\n", (unsigned int)hwm));

			break;
		case ID_GROUPID:
			if ((hwm = tdb_fetch_int32(idmap_tdb, HWM_GROUP)) == -1) {
				return NT_STATUS_INTERNAL_DB_ERROR;
			}

			/* check it is in the range */
			if (hwm > idmap_state.gid_high) {
				DEBUG(0, ("idmap Fatal Error: GID range full!! (max: %lu)\n", 
					  (unsigned long)idmap_state.gid_high));
				return NT_STATUS_UNSUCCESSFUL;
			}

			/* fetch a new id and increment it */
			ret = tdb_change_uint32_atomic(idmap_tdb, HWM_GROUP, (unsigned int *)&hwm, 1);

			if (!ret) {
				DEBUG(0, ("idmap_tdb: Fatal error while fetching a new id\n!"));
				return NT_STATUS_UNSUCCESSFUL;
			}

			/* recheck it is in the range */
			if (hwm > idmap_state.gid_high) {
				DEBUG(0, ("idmap Fatal Error: GID range full!! (max: %lu)\n", 
					  (unsigned long)idmap_state.gid_high));
				return NT_STATUS_UNSUCCESSFUL;
			}
			
			(*id).gid = hwm;
			DEBUG(10,("db_allocate_id: ID_GROUPID (*id).gid = %d\n", (unsigned int)hwm));
			
			break;
		default:
			return NT_STATUS_INVALID_PARAMETER;
	}

	return NT_STATUS_OK;
}

/* Get a sid from an id */
static NTSTATUS internal_get_sid_from_id(DOM_SID *sid, unid_t id, int id_type)
{
	TDB_DATA key, data;
	fstring keystr;
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;

	if (!sid)
		return NT_STATUS_INVALID_PARAMETER;

	switch (id_type & ID_TYPEMASK) {
		case ID_USERID:
			slprintf(keystr, sizeof(keystr), "UID %lu", (unsigned long)id.uid);
			break;
		case ID_GROUPID:
			slprintf(keystr, sizeof(keystr), "GID %lu", (unsigned long)id.gid);
			break;
		default:
			return NT_STATUS_UNSUCCESSFUL;
	}

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

	DEBUG(10,("internal_get_sid_from_id: fetching record %s\n", keystr ));

	data = tdb_fetch(idmap_tdb, key);

	if (data.dptr) {
		if (string_to_sid(sid, data.dptr)) {
			DEBUG(10,("internal_get_sid_from_id: fetching record %s -> %s\n", keystr, data.dptr ));
			ret = NT_STATUS_OK;
		}
		SAFE_FREE(data.dptr);
	}

	return ret;
}

/* Error codes for get_id_from_sid */
enum getidfromsiderr { GET_ID_FROM_SID_OK = 0, GET_ID_FROM_SID_NOTFOUND, GET_ID_FROM_SID_WRONG_TYPE, GET_ID_FROM_SID_ERR };

static enum getidfromsiderr internal_get_id_from_sid(unid_t *id, int *id_type, const DOM_SID *sid) 
{
	enum getidfromsiderr ret = GET_ID_FROM_SID_ERR;
	fstring keystr;
	TDB_DATA key, data;
	int type = *id_type & ID_TYPEMASK;

	/* Check if sid is present in database */
	sid_to_string(keystr, sid);

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

	DEBUG(10,("internal_get_id_from_sid: fetching record %s of type 0x%x\n", keystr, type ));

	data = tdb_fetch(idmap_tdb, key);
	if (!data.dptr) {
		DEBUG(10,("internal_get_id_from_sid: record %s not found\n", keystr ));
		return GET_ID_FROM_SID_NOTFOUND;
	} else {
		DEBUG(10,("internal_get_id_from_sid: record %s -> %s\n", keystr, data.dptr ));
	}

	if (type == ID_EMPTY || type == ID_USERID) {
		fstring scanstr;
		/* Parse and return existing uid */
		fstrcpy(scanstr, "UID %d");
		
		if (sscanf(data.dptr, scanstr, &((*id).uid)) == 1) {
			/* uid ok? */
			if (type == ID_EMPTY) {
				*id_type = ID_USERID;
			}
			DEBUG(10,("internal_get_id_from_sid: %s fetching record %s -> %s \n",
						(type == ID_EMPTY) ? "ID_EMPTY" : "ID_USERID",
						keystr, data.dptr ));
			ret = GET_ID_FROM_SID_OK;
		} else {
			ret = GET_ID_FROM_SID_WRONG_TYPE;
		}
	}
	
	if ((ret != GET_ID_FROM_SID_OK) && (type == ID_EMPTY || type == ID_GROUPID)) {
		fstring scanstr;
		/* Parse and return existing gid */
		fstrcpy(scanstr, "GID %d");
		
		if (sscanf(data.dptr, scanstr, &((*id).gid)) == 1) {
			/* gid ok? */
			if (type == ID_EMPTY) {
				*id_type = ID_GROUPID;
			}
			DEBUG(10,("internal_get_id_from_sid: %s fetching record %s -> %s \n",
						(type == ID_EMPTY) ? "ID_EMPTY" : "ID_GROUPID",
						keystr, data.dptr ));
			ret = GET_ID_FROM_SID_OK;
		} else {
			ret = GET_ID_FROM_SID_WRONG_TYPE;
		}
	}
	
	SAFE_FREE(data.dptr);

	return ret;
}

/* Get a sid from an id */
static NTSTATUS db_get_sid_from_id(DOM_SID *sid, unid_t id, int id_type_in)
{
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
	enum getidfromsiderr iderr;
	int id_type = id_type_in & ID_TYPEMASK;
	unid_t id_tmp = id;
	int id_type_tmp = id_type;

	DEBUG(10,("db_get_sid_from_id: id_type_in = 0x%x\n", id_type_in));

	ret = internal_get_sid_from_id(sid, id, id_type);
	if (!NT_STATUS_IS_OK(ret)) {
		return ret;
	}
	
	iderr = internal_get_id_from_sid(&id_tmp, &id_type_tmp, sid);
	if (iderr != GET_ID_FROM_SID_OK) {
		return NT_STATUS_UNSUCCESSFUL;
	}
	if (id_type_tmp != id_type) {
		return NT_STATUS_UNSUCCESSFUL;
	} else if (id_type == ID_USERID) { 
		if (id_tmp.uid != id.uid) {
			return NT_STATUS_UNSUCCESSFUL;
		}
	} else if (id_type == ID_GROUPID) {
		if (id_tmp.gid != id.gid) {
			return NT_STATUS_UNSUCCESSFUL;
		}
	} else {
		return NT_STATUS_UNSUCCESSFUL;
	}
	return ret;
}
/* Get an id from a sid */
static NTSTATUS db_get_id_from_sid(unid_t *id, int *id_type, const DOM_SID *sid)
{
	NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
	enum getidfromsiderr iderr;

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

	if (!sid || !id || !id_type)
		return NT_STATUS_INVALID_PARAMETER;

	iderr = internal_get_id_from_sid(id, id_type, sid);
	if (iderr == GET_ID_FROM_SID_OK) {
		DOM_SID sid_tmp;
		ret = internal_get_sid_from_id(&sid_tmp, *id, *id_type);
		if (NT_STATUS_IS_OK(ret)) {
			if (!sid_equal(&sid_tmp, sid)) {
				return NT_STATUS_UNSUCCESSFUL;
			}
		}
	} else if (iderr == GET_ID_FROM_SID_WRONG_TYPE) {
		/* We found a record but not the type we wanted.
		 * This is an error, not an opportunity to overwrite...
		 * JRA.
		 */
		return NT_STATUS_UNSUCCESSFUL;
	}

	if (!(*id_type & ID_QUERY_ONLY) && (iderr != GET_ID_FROM_SID_OK) &&
		   (((*id_type & ID_TYPEMASK) == ID_USERID)
		    || (*id_type & ID_TYPEMASK) == ID_GROUPID)) {