/* $OpenLDAP$ */
/*
 * Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
 * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
 */
/* backend.c - routines for dealing with back-end databases */


#include "portable.h"

#include <stdio.h>

#include <ac/string.h>
#include <ac/socket.h>

#include <sys/stat.h>

#include "slap.h"
#include "lutil.h"

#ifdef SLAPD_DNSSRV
#include "back-dnssrv/external.h"
#endif
#ifdef SLAPD_LDAP
#include "back-ldap/external.h"
#endif
#ifdef SLAPD_LDBM
#include "back-ldbm/external.h"
#endif
#ifdef SLAPD_PASSWD
#include "back-passwd/external.h"
#endif
#ifdef SLAPD_PERL
#include "back-perl/external.h"
#endif
#ifdef SLAPD_SHELL
#include "back-shell/external.h"
#endif
#ifdef SLAPD_TCL
#include "back-tcl/external.h"
#endif
#ifdef SLAPD_SQL
#include "back-sql/external.h"
#endif
#ifdef SLAPD_PRIVATE
#include "private/external.h"
#endif

static BackendInfo binfo[] = {
#if defined(SLAPD_DNSSRV) && !defined(SLAPD_DNSSRV_DYNAMIC)
	{"dnssrv",	dnssrv_back_initialize},
#endif
#if defined(SLAPD_LDAP) && !defined(SLAPD_LDAP_DYNAMIC)
	{"ldap",	ldap_back_initialize},
#endif
#if defined(SLAPD_LDBM) && !defined(SLAPD_LDBM_DYNAMIC)
	{"ldbm",	ldbm_back_initialize},
#endif
#if defined(SLAPD_PASSWD) && !defined(SLAPD_PASSWD_DYNAMIC)
	{"passwd",	passwd_back_initialize},
#endif
#if defined(SLAPD_PERL) && !defined(SLAPD_PERL_DYNAMIC)
	{"perl",	perl_back_initialize},
#endif
#if defined(SLAPD_SHELL) && !defined(SLAPD_SHELL_DYNAMIC)
	{"shell",	shell_back_initialize},
#endif
#if defined(SLAPD_TCL) && !defined(SLAPD_TCL_DYNAMIC)
	{"tcl",		tcl_back_initialize},
#endif
#if defined(SLAPD_SQL) && !defined(SLAPD_SQL_DYNAMIC)
	{"sql",		sql_back_initialize},
#endif
	/* for any private backend */
#if defined(SLAPD_PRIVATE) && !defined(SLAPD_PRIVATE_DYNAMIC)
	{"private",	private_back_initialize},
#endif
	{NULL}
};

int			nBackendInfo = 0;
BackendInfo	*backendInfo = NULL;

int			nBackendDB = 0; 
BackendDB	*backendDB = NULL;

int backend_init(void)
{
	int rc = -1;

	if((nBackendInfo != 0) || (backendInfo != NULL)) {
		/* already initialized */
		Debug( LDAP_DEBUG_ANY,
			"backend_init: already initialized.\n", 0, 0, 0 );
		return -1;
	}

	for( ;
		binfo[nBackendInfo].bi_type != NULL;
		nBackendInfo++ )
	{
		rc = binfo[nBackendInfo].bi_init( &binfo[nBackendInfo] );

		if(rc != 0) {
			Debug( LDAP_DEBUG_ANY,
				"backend_init: initialized for type \"%s\"\n",
					binfo[nBackendInfo].bi_type, 0, 0 );

			/* destroy those we've already inited */
			for( nBackendInfo--;
				nBackendInfo >= 0 ;
				nBackendInfo-- )
			{ 
				if ( binfo[nBackendInfo].bi_destroy ) {
					binfo[nBackendInfo].bi_destroy(
						&binfo[nBackendInfo] );
				}
			}
			return rc;
		}
	}

	if ( nBackendInfo > 0) {
		backendInfo = binfo;
		return 0;
	}

#ifdef SLAPD_MODULES	
	return 0;
#else
	Debug( LDAP_DEBUG_ANY,
		"backend_init: failed\n",
		0, 0, 0 );

	return rc;
#endif /* SLAPD_MODULES */
}

int backend_add(BackendInfo *aBackendInfo)
{
   int rc = 0;

   if ((rc = aBackendInfo->bi_init(aBackendInfo)) != 0) {
      Debug( LDAP_DEBUG_ANY,
	     "backend_add: initialization for type \"%s\" failed\n",
	     aBackendInfo->bi_type, 0, 0 );
      return rc;
   }

   /* now add the backend type to the Backend Info List */
   {
      BackendInfo *newBackendInfo = 0;

      /* if backendInfo == binfo no deallocation of old backendInfo */
      if (backendInfo == binfo) {
	 newBackendInfo = ch_calloc(nBackendInfo + 1, sizeof(BackendInfo));
	 AC_MEMCPY(newBackendInfo, backendInfo, sizeof(BackendInfo) * 
		nBackendInfo);
      } else {
	 newBackendInfo = ch_realloc(backendInfo, sizeof(BackendInfo) * 
				     (nBackendInfo + 1));
      }
      AC_MEMCPY(&newBackendInfo[nBackendInfo], aBackendInfo, 
	     sizeof(BackendInfo));
      backendInfo = newBackendInfo;
      nBackendInfo++;

      return 0;
   }	    
}

int backend_startup(Backend *be)
{
	int i;
	int rc = 0;

	if( ! ( nBackendDB > 0 ) ) {
		/* no databases */
		Debug( LDAP_DEBUG_ANY,
			"backend_startup: %d databases to startup.\n",
			nBackendDB, 0, 0 );
		return 1;
	}

	if(be != NULL) {
		/* startup a specific backend database */
		Debug( LDAP_DEBUG_TRACE,
			"backend_startup: starting database\n",
			0, 0, 0 );

		if ( be->bd_info->bi_open ) {
			rc = be->bd_info->bi_open( be->bd_info );
		}

		if(rc != 0) {
			Debug( LDAP_DEBUG_ANY,
				"backend_startup: bi_open failed!\n",
				0, 0, 0 );
			return rc;
		}

		if ( be->bd_info->bi_db_open ) {
			rc = be->bd_info->bi_db_open( be );
		}

		if(rc != 0) {
			Debug( LDAP_DEBUG_ANY,
				"backend_startup: bi_db_open failed!\n",
				0, 0, 0 );
			return rc;
		}

		return rc;
	}

	/* open each backend type */
	for( i = 0; i < nBackendInfo; i++ ) {
		if( backendInfo[i].bi_nDB == 0) {
			/* no database of this type, don't open */
			continue;
		}

		if( backendInfo[i].bi_open ) {
			rc = backendInfo[i].bi_open(
				&backendInfo[i] );
		}

		if(rc != 0) {
			Debug( LDAP_DEBUG_ANY,
				"backend_startup: bi_open %d failed!\n",
				i, 0, 0 );
			return rc;
		}
	}

	/* open each backend database */
	for( i = 0; i < nBackendDB; i++ ) {
		/* append global access controls */
		acl_append( &backendDB[i].be_acl, global_acl );

		if ( backendDB[i].bd_info->bi_db_open ) {
			rc = backendDB[i].bd_info->bi_db_open(
				&backendDB[i] );
		}

		if(rc != 0) {
			Debug( LDAP_DEBUG_ANY,
				"backend_startup: bi_db_open %d failed!\n",
				i, 0, 0 );
			return rc;
		}
	}

	return rc;
}

int backend_num( Backend *be )
{
	int i;

	if( be == NULL ) return -1;

	for( i = 0; i < nBackendDB; i++ ) {
		if( be == &backendDB[i] ) return i;
	}
	return -1;
}

int backend_shutdown( Backend *be )
{
	int i;
	int rc = 0;

	if( be != NULL ) {
		/* shutdown a specific backend database */

		if ( be->bd_info->bi_nDB == 0 ) {
			/* no database of this type, we never opened it */
			return 0;
		}

		if ( be->bd_info->bi_db_close ) {
			be->bd_info->bi_db_close( be );
		}

		if( be->bd_info->bi_close ) {
			be->bd_info->bi_close( be->bd_info );
		}

		return 0;
	}

	/* close each backend database */
	for( i = 0; i < nBackendDB; i++ ) {
		if ( backendDB[i].bd_info->bi_db_close ) {
			backendDB[i].bd_info->bi_db_close(
				&backendDB[i] );
		}

		if(rc != 0) {
			Debug( LDAP_DEBUG_ANY,
				"backend_close: bi_close %s failed!\n",
				backendDB[i].be_type, 0, 0 );
		}
	}

	/* close each backend type */
	for( i = 0; i < nBackendInfo; i++ ) {
		if( backendInfo[i].bi_nDB == 0 ) {
			/* no database of this type */
			continue;
		}

		if( backendInfo[i].bi_close ) {
			backendInfo[i].bi_close(
				&backendInfo[i] );
		}
	}

	return 0;
}

int backend_destroy(void)
{
	int i;

	/* destroy each backend database */
	for( i = 0; i < nBackendDB; i++ ) {
		if ( backendDB[i].bd_info->bi_db_destroy ) {
			backendDB[i].bd_info->bi_db_destroy(
				&backendDB[i] );
		}
	}

	/* destroy each backend type */
	for( i = 0; i < nBackendInfo; i++ ) {
		if( backendInfo[i].bi_destroy ) {
			backendInfo[i].bi_destroy(
				&backendInfo[i] );
		}
	}

#ifdef SLAPD_MODULES
	if (backendInfo != binfo) {
	   free(backendInfo);
	}
#endif /* SLAPD_MODULES */

	nBackendInfo = 0;
	backendInfo = NULL;

	return 0;
}

BackendInfo* backend_info(const char *type)
{
	int i;

	/* search for the backend type */
	for( i = 0; i < nBackendInfo; i++ ) {
		if( strcasecmp(backendInfo[i].bi_type, type) == 0 ) {
			return &backendInfo[i];
		}
	}

	return NULL;
}


BackendDB *
backend_db_init(
    const char	*type
)
{
	Backend	*be;
	BackendInfo *bi = backend_info(type);
	int	rc = 0;

	if( bi == NULL ) {
		fprintf( stderr, "Unrecognized database type (%s)\n", type );
		return NULL;
	}

	backendDB = (BackendDB *) ch_realloc(
			(char *) backendDB,
		    (nBackendDB + 1) * sizeof(Backend) );

	memset( &backendDB[nbackends], '\0', sizeof(Backend) );

	be = &backends[nbackends++];

	be->bd_info = bi;
	be->be_sizelimit = defsize;
	be->be_timelimit = deftime;
	be->be_dfltaccess = global_default_access;

	be->be_restrictops = global_restrictops;
	be->be_requires = global_requires;

 	/* assign a default depth limit for alias deref */
	be->be_max_deref_depth = SLAPD_DEFAULT_MAXDEREFDEPTH; 

	if(bi->bi_db_init) {
		rc = bi->bi_db_init( be );
	}

	if(rc != 0) {
		fprintf( stderr, "database init failed (%s)\n", type );
		nbackends--;
		return NULL;
	}

	bi->bi_nDB++;
	return( be );
}

void
be_db_close( void )
{
	int	i;

	for ( i = 0; i < nbackends; i++ ) {
		if ( backends[i].bd_info->bi_db_close ) {
			(*backends[i].bd_info->bi_db_close)( &backends[i] );
		}
	}
}

Backend *
select_backend( const char * dn )
{
	int	i, j, len, dnlen;

	dnlen = strlen( dn );
	for ( i = 0; i < nbackends; i++ ) {
		for ( j = 0; backends[i].be_nsuffix != NULL &&
		    backends[i].be_nsuffix[j] != NULL; j++ )
		{
			len = strlen( backends[i].be_nsuffix[j] );

			if ( len > dnlen ) {
				continue;
			}

			if ( strcmp( backends[i].be_nsuffix[j],
			    dn + (dnlen - len) ) == 0 ) {
				return( &backends[i] );
			}
		}
	}

	return( NULL );
}

int
be_issuffix(
    Backend	*be,
    const char	*suffix
)
{
	int	i;

	for ( i = 0; be->be_nsuffix != NULL && be->be_nsuffix[i] != NULL; i++ ) {
		if ( strcmp( be->be_nsuffix[i], suffix ) == 0 ) {
			return( 1 );
		}
	}

	return( 0 );
}

int
be_isroot( Backend *be, const char *ndn )
{
	int rc;

	if ( ndn == NULL || *ndn == '\0' ) {
		return( 0 );
	}

	if ( be->be_root_ndn == NULL || *be->be_root_ndn == '\0' ) {
		return( 0 );
	}

	rc = strcmp( be->be_root_ndn, ndn ) ? 0 : 1;

	return(rc);
}

char *
be_root_dn( Backend *be )
{
	if ( be->be_root_dn == NULL ) {
		return( "" );
	}

	return be->be_root_dn;
}

int
be_isroot_pw( Backend *be, const char *ndn, struct berval *cred )
{
	int result;

	if ( ! be_isroot( be, ndn ) ) {
		return 0;
	}

	if( be->be_root_pw.bv_len == 0 ) {
		return 0;
	}

#ifdef SLAPD_CRYPT
	ldap_pvt_thread_mutex_lock( &crypt_mutex );
#endif

	result = lutil_passwd( &be->be_root_pw, cred, NULL );

#ifdef SLAPD_CRYPT
	ldap_pvt_thread_mutex_unlock( &crypt_mutex );
#endif

	return result == 0;
}

int
be_entry_release_rw( Backend *be, Entry *e, int rw )
{
	if ( be->be_release ) {
		/* free and release entry from backend */
		return be->be_release( be, e, rw );
	} else {
		/* free entry */
		entry_free( e );
		return 0;
	}
}

int
backend_unbind(
	Connection   *conn,
	Operation    *op
)
{
	int	i;

	for ( i = 0; i < nbackends; i++ ) {
		if ( backends[i].be_unbind ) {
			(*backends[i].be_unbind)( &backends[i], conn, op );
		}
	}

	return 0;
}

int
backend_connection_init(
	Connection   *conn
)
{
	int	i;

	for ( i = 0; i < nbackends; i++ ) {
		if ( backends[i].be_connection_init ) {
			(*backends[i].be_connection_init)( &backends[i], conn);
		}
	}

	return 0;
}

int
backend_connection_destroy(
	Connection   *conn
)
{
	int	i;

	for ( i = 0; i < nbackends; i++ ) {
		if ( backends[i].be_connection_destroy ) {
			(*backends[i].be_connection_destroy)( &backends[i], conn);
		}
	}

	return 0;
}

static int
backend_check_controls(
	Backend *be,
	Connection *conn,
	Operation *op,
	const char **text )
{
	LDAPControl **ctrls;
	ctrls = op->o_ctrls;
	if( ctrls == NULL ) {
		return LDAP_SUCCESS;
	}

	for( ; *ctrls != NULL ; ctrls++ ) {
		if( (*ctrls)->ldctl_iscritical &&
			!charray_inlist( be->be_controls, (*ctrls)->ldctl_oid ) )
		{
			*text = "control unavailable in NamingContext";
			return LDAP_UNAVAILABLE_CRITICAL_EXTENSION;
		}
	}

	return LDAP_SUCCESS;
}

int
backend_check_restrictions(
	Backend *be,
	Connection *conn,
	Operation *op,
	const char *extoid,
	const char **text )
{
	int rc;
	slap_mask_t restrictops;
	slap_mask_t requires;
	slap_mask_t opflag;
	slap_ssf_set_t *ssf;
	int updateop = 0;

	if( be ) {
		rc = backend_check_controls( be, conn, op, text );

		if( rc != LDAP_SUCCESS ) {
			return rc;
		}

		restrictops = be->be_restrictops;
		requires = be->be_requires;
		ssf = &be->be_ssf_set;

	} else {
		restrictops = global_restrictops;
		requires = global_requires;
		ssf = &global_ssf_set;
	}

	switch( op->o_tag ) {
	case LDAP_REQ_ADD:
		opflag = SLAP_RESTRICT_OP_ADD;
		updateop++;
		break;
	case LDAP_REQ_BIND:
		opflag = SLAP_RESTRICT_OP_BIND;
		break;
	case LDAP_REQ_COMPARE:
		opflag = SLAP_RESTRICT_OP_COMPARE;
		break;
	case LDAP_REQ_DELETE:
		updateop++;
		opflag = SLAP_RESTRICT_OP_DELETE;
		break;
	case LDAP_REQ_EXTENDED:
		opflag = SLAP_RESTRICT_OP_EXTENDED;
		break;
	case LDAP_REQ_MODIFY:
		updateop++;
		opflag = SLAP_RESTRICT_OP_MODIFY;
		break;
	case LDAP_REQ_RENAME:
		updateop++;
		opflag = SLAP_RESTRICT_OP_RENAME;
		break;
	case LDAP_REQ_SEARCH:
		opflag = SLAP_RESTRICT_OP_SEARCH;
		break;
	case LDAP_REQ_UNBIND:
		opflag = 0;
		break;
	default:
		*text = "restrict operations internal error";
		return LDAP_OTHER;
	}

	if (( extoid == NULL || strcmp( extoid, LDAP_EXOP_START_TLS ) ) ) {
		/* these checks don't apply to StartTLS */

		if( op->o_tag == LDAP_REQ_EXTENDED ) {
			/* threat other extended operations as update ops */
			updateop++;
		}

		if( op->o_ssf < ssf->sss_ssf ) {
			*text = "confidentiality required";
			return LDAP_CONFIDENTIALITY_REQUIRED;
		}
		if( op->o_transport_ssf < ssf->sss_transport ) {
			*text = "transport confidentiality required";
			return LDAP_CONFIDENTIALITY_REQUIRED;
		}
		if( op->o_tls_ssf < ssf->sss_tls ) {
			*text = "TLS confidentiality required";
			return LDAP_CONFIDENTIALITY_REQUIRED;
		}
		if( op->o_sasl_ssf < ssf->sss_sasl ) {
			*text = "SASL confidentiality required";
			return LDAP_CONFIDENTIALITY_REQUIRED;
		}

		if( updateop ) {
			if( op->o_ssf < ssf->sss_update_ssf ) {
				*text = "update confidentiality required";
				return LDAP_CONFIDENTIALITY_REQUIRED;
			}
			if( op->o_transport_ssf < ssf->sss_update_transport ) {
				*text = "transport update confidentiality required";
				return LDAP_CONFIDENTIALITY_REQUIRED;
			}
			if( op->o_tls_ssf < ssf->sss_update_tls ) {
				*text = "TLS update confidentiality required";
				return LDAP_CONFIDENTIALITY_REQUIRED;
			}
			if( op->o_sasl_ssf < ssf->sss_update_sasl ) {
				*text = "SASL update confidentiality required";
				return LDAP_CONFIDENTIALITY_REQUIRED;
			}
		}
	}

	if (( extoid == NULL || strcmp( extoid, LDAP_EXOP_START_TLS ) )
		|| op->o_tag == LDAP_REQ_BIND )
	{
		/* these checks don't apply to StartTLS or Bind */

		if( requires & SLAP_REQUIRE_STRONG ) {
			/* should check mechanism */
			if( op->o_authmech == NULL ||
				op->o_dn == NULL || *op->o_dn == '\0' )
			{
				*text = "strong authentication required";
				return LDAP_STRONG_AUTH_REQUIRED;
			}
		}

		if( requires & SLAP_REQUIRE_SASL ) {
			if( op->o_authmech == NULL ||
				op->o_dn == NULL || *op->o_dn == '\0' )
			{
				*text = "SASL authentication required";
				return LDAP_STRONG_AUTH_REQUIRED;
			}
		}
			
		if( requires & SLAP_REQUIRE_AUTHC ) {
			if( op->o_dn == NULL || *op->o_dn == '\0' ) {
				*text = "authentication required";
				return LDAP_UNWILLING_TO_PERFORM;
			}
		}

		if( requires & SLAP_REQUIRE_BIND ) {
			int version;
			ldap_pvt_thread_mutex_lock( &conn->c_mutex );
			version = conn->c_protocol;
			ldap_pvt_thread_mutex_unlock( &conn->c_mutex );

			if( !version ) {
				/* no bind has occurred */
				*text = "BIND required";
				return LDAP_OPERATIONS_ERROR;
			}
		}

		if( requires & SLAP_REQUIRE_LDAP_V3 ) {
			if( op->o_protocol < LDAP_VERSION3 ) {
				/* no bind has occurred */
				*text = "operation restricted to LDAPv3 clients";
				return LDAP_OPERATIONS_ERROR;
			}
		}
	}

	if( restrictops & opflag ) {
		if( restrictops == SLAP_RESTRICT_OP_READS ) {
			*text = "read operations restricted";
		} else {
			*text = "operation restricted";
		}
		return LDAP_UNWILLING_TO_PERFORM;
 	}

	return LDAP_SUCCESS;
}

int backend_check_referrals(
	Backend *be,
	Connection *conn,
	Operation *op,
	const char *dn,
	const char *ndn )
{
	int rc = LDAP_SUCCESS;

	if( be->be_chk_referrals ) {
		const char *text;

		rc = be->be_chk_referrals( be,
			conn, op, dn, ndn, &text );

		if( rc != LDAP_SUCCESS && rc != LDAP_REFERRAL ) {
			send_ldap_result( conn, op, rc,
				NULL, text, NULL, NULL );
		}
	}

	return rc;
}

int 
backend_group(
	Backend	*be,
	Entry	*target,
	const char	*gr_ndn,
	const char	*op_ndn,
	ObjectClass *group_oc,
	AttributeDescription *group_at
)
{
	if( strcmp( target->e_ndn, gr_ndn ) != 0 ) {
		/* we won't attempt to send it to a different backend */
		
		be = select_backend(gr_ndn);

		if (be == NULL) {
			return LDAP_NO_SUCH_OBJECT;
		}
	} 

	if( be->be_group ) {
		return be->be_group( be, target, gr_ndn, op_ndn,
			group_oc, group_at );
	}

	return LDAP_UNWILLING_TO_PERFORM;
}

int 
backend_attribute(
	Backend	*be,
	Connection *conn,
	Operation *op,
	Entry	*target,
	const char	*e_ndn,
	AttributeDescription *entry_at,
	struct berval ***vals
)
{
	if( target == NULL || strcmp( target->e_ndn, e_ndn ) != 0 ) {
		/* we won't attempt to send it to a different backend */
		
		be = select_backend(e_ndn);

		if (be == NULL) {
			return LDAP_NO_SUCH_OBJECT;
		}
	} 

	if( be->be_attribute ) {
		return be->be_attribute( be, conn, op, target, e_ndn,
			entry_at, vals );
	}

	return LDAP_UNWILLING_TO_PERFORM;
}

Attribute *backend_operational(
	Backend *be,
	Entry *e )
{
	Attribute *a = NULL;

#ifdef SLAPD_SCHEMA_DN
	a = ch_malloc( sizeof( Attribute ) );
	a->a_desc = ad_dup( slap_schema.si_ad_subschemaSubentry );

	/* Should be backend specific */
	a->a_vals = ch_malloc( 2 * sizeof( struct berval * ) );
	a->a_vals[0] = ber_bvstrdup( SLAPD_SCHEMA_DN );
	a->a_vals[1] = NULL;

	a->a_next = NULL;
#endif

	return a;
}