Disable databases & overlays (experimental)

Do not use. backend/overlay code needs to be fixed accordingly.
In particular, code which currently frees configuration in _db_close()
must be changed to free only in _db_destroy().

After restructuring, it must be possible to call _db_close()/_db_open()
multiple times in succession without requiring _db_config() in between.

servers/slapd/backend.c

@@ -264,6 +264,9 @@ int backend_startup(Backend *be)
 	}
 
 	if(be != NULL) {
+		/* silent noop if disabled */
+		if ( SLAP_DBDISABLED( be ))
+			return 0;
 		if ( be->bd_info->bi_open ) {
 			rc = be->bd_info->bi_open( be->bd_info );
 			if ( rc != 0 ) {
@@ -315,6 +318,8 @@ int backend_startup(Backend *be)
 	i = -1;
 	LDAP_STAILQ_FOREACH(be, &backendDB, be_next) {
 		i++;
+		if ( SLAP_DBDISABLED( be ))
+			continue;
 		if ( be->be_suffix == NULL ) {
 			Debug( LDAP_DEBUG_ANY,
 				"backend_startup: warning, database %d (%s) "
@@ -372,6 +377,8 @@ int backend_shutdown( Backend *be )
 
 	/* close each backend database */
 	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( SLAP_DBDISABLED( be ))
+			continue;
 		if ( be->bd_info->bi_db_close ) {
 			be->bd_info->bi_db_close( be, NULL );
 		}
@@ -666,7 +673,7 @@ select_backend(
 	Backend		*be;
 
 	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
-		if ( be->be_nsuffix == NULL || SLAP_DBHIDDEN( be )) {
+		if ( be->be_nsuffix == NULL || SLAP_DBHIDDEN( be ) || SLAP_DBDISABLED( be )) {
 			continue;
 		}
 

servers/slapd/backover.c

@@ -150,6 +150,8 @@ over_db_open(
 	}
 
 	for (; on && rc == 0; on=on->on_next) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		db.bd_info = &on->on_bi;
 		if ( db.bd_info->bi_db_open ) {
 			rc = db.bd_info->bi_db_open( &db, cr );
@@ -171,6 +173,8 @@ over_db_close(
 	int rc = 0;
 
 	for (; on && rc == 0; on=on->on_next) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		be->bd_info = &on->on_bi;
 		if ( be->bd_info->bi_db_close ) {
 			rc = be->bd_info->bi_db_close( be, cr );
@@ -203,6 +207,8 @@ over_db_destroy(
 	}
 
 	for (; on && rc == 0; on=on->on_next) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		be->bd_info = &on->on_bi;
 		if ( be->bd_info->bi_db_destroy ) {
 			rc = be->bd_info->bi_db_destroy( be, cr );
@@ -232,6 +238,8 @@ over_back_response ( Operation *op, SlapReply *rs )
 	db.be_flags |= SLAP_DBFLAG_OVERLAY;
 	op->o_bd = &db;
 	for (; on; on=on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		if ( on->on_response ) {
 			db.bd_info = (BackendInfo *)on;
 			rc = on->on_response( op, rs );
@@ -277,6 +285,8 @@ over_access_allowed(
 	on = oi->oi_list;
 
 	for ( ; on; on = on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		if ( on->on_bi.bi_access_allowed ) {
 			/* NOTE: do not copy the structure until required */
 		 	if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
@@ -338,6 +348,8 @@ overlay_entry_get_ov(
 	int rc = SLAP_CB_CONTINUE;
 
 	for ( ; on; on = on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		if ( on->on_bi.bi_entry_get_rw ) {
 			/* NOTE: do not copy the structure until required */
 		 	if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
@@ -409,6 +421,8 @@ overlay_entry_release_ov(
 	int rc = SLAP_CB_CONTINUE;
 
 	for ( ; on; on = on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		if ( on->on_bi.bi_entry_release_rw ) {
 			/* NOTE: do not copy the structure until required */
 		 	if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
@@ -487,6 +501,8 @@ over_acl_group(
 	on = oi->oi_list;
 
 	for ( ; on; on = on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		if ( on->on_bi.bi_acl_group ) {
 			/* NOTE: do not copy the structure until required */
 		 	if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
@@ -556,6 +572,8 @@ over_acl_attribute(
 	on = oi->oi_list;
 
 	for ( ; on; on = on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		if ( on->on_bi.bi_acl_attribute ) {
 			/* NOTE: do not copy the structure until required */
 		 	if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
@@ -655,6 +673,8 @@ int overlay_op_walk(
 	int rc = SLAP_CB_CONTINUE;
 
 	for (; on; on=on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		func = &on->on_bi.bi_op_bind;
 		if ( func[which] ) {
 			op->o_bd->bd_info = (BackendInfo *)on;
@@ -849,6 +869,8 @@ over_connection_func(
 	}
 
 	for ( ; on; on = on->on_next ) {
+		if ( on->on_bi.bi_flags & SLAPO_BFLAG_DISABLED )
+			continue;
 		func = &on->on_bi.bi_connection_init;
 		if ( func[ which ] ) {
 			bd->bd_info = (BackendInfo *)on;

servers/slapd/bconfig.c

@@ -197,6 +197,7 @@ enum {
 	CFG_SYNC_SUBENTRY,
 	CFG_LTHREADS,
 	CFG_IX_HASH64,
+	CFG_DISABLED,
 
 	CFG_LAST
 };
@@ -364,6 +365,9 @@ static ConfigTable config_back_cf_table[] = {
 	{ "defaultSearchBase", "dn", 2, 2, 0, ARG_PRE_BI|ARG_PRE_DB|ARG_DN|ARG_QUOTE|ARG_MAGIC,
 		&config_search_base, "( OLcfgGlAt:14 NAME 'olcDefaultSearchBase' "
 			"SYNTAX OMsDN SINGLE-VALUE )", NULL, NULL },
+	{ "disabled", "on|off", 2, 2, 0, ARG_DB|ARG_ON_OFF|ARG_MAGIC|CFG_DISABLED,
+		&config_generic, "( OLcfgDbAt:0.21 NAME 'olcDisabled' "
+			"SYNTAX OMsBoolean SINGLE-VALUE )", NULL, NULL },
 	{ "disallows", "features", 2, 0, 8, ARG_PRE_DB|ARG_MAGIC,
 		&config_disallows, "( OLcfgGlAt:15 NAME 'olcDisallows' "
 			"EQUALITY caseIgnoreMatch "
@@ -865,7 +869,7 @@ static ConfigOCs cf_ocs[] = {
 		"DESC 'OpenLDAP Database-specific options' "
 		"SUP olcConfig STRUCTURAL "
 		"MUST olcDatabase "
-		"MAY ( olcHidden $ olcSuffix $ olcSubordinate $ olcAccess $ "
+		"MAY ( olcDisabled $ olcHidden $ olcSuffix $ olcSubordinate $ olcAccess $ "
 		 "olcAddContentAcl $ olcLastMod $ olcLimits $ "
 		 "olcMaxDerefDepth $ olcPlugin $ olcReadOnly $ olcReplica $ "
 		 "olcReplicaArgsFile $ olcReplicaPidFile $ olcReplicationInterval $ "
@@ -878,7 +882,8 @@ static ConfigOCs cf_ocs[] = {
 		"NAME 'olcOverlayConfig' "
 		"DESC 'OpenLDAP Overlay-specific options' "
 		"SUP olcConfig STRUCTURAL "
-		"MUST olcOverlay )", Cft_Overlay, NULL, cfAddOverlay },
+		"MUST olcOverlay "
+		"MAY olcDisabled )", Cft_Overlay, NULL, cfAddOverlay },
 	{ "( OLcfgGlOc:6 "
 		"NAME 'olcIncludeFile' "
 		"DESC 'OpenLDAP configuration include file' "
@@ -1043,6 +1048,23 @@ config_generic(ConfigArgs *c) {
 		case CFG_DEPTH:
 			c->value_int = c->be->be_max_deref_depth;
 			break;
+		case CFG_DISABLED:
+			if ( c->bi ) {
+				/* overlay */
+				if ( c->bi->bi_flags & SLAPO_BFLAG_DISABLED ) {
+					c->value_int = 1;
+				} else {
+					rc = 1;
+				}
+			} else {
+				/* database */
+				if ( SLAP_DBDISABLED( c->be )) {
+					c->value_int = 1;
+				} else {
+					rc = 1;
+				}
+			}
+			break;
 		case CFG_HIDDEN:
 			if ( SLAP_DBHIDDEN( c->be )) {
 				c->value_int = 1;
@@ -1385,6 +1407,21 @@ config_generic(ConfigArgs *c) {
 			c->be->be_flags &= ~SLAP_DBFLAG_HIDDEN;
 			break;
 
+		case CFG_DISABLED:
+			if ( c->bi ) {
+				c->bi->bi_flags &= ~SLAP_DBFLAG_DISABLED;
+				if ( c->bi->bi_db_open ) {
+					BackendInfo *bi_orig = c->be->bd_info;
+					c->be->bd_info = c->bi;
+					rc = c->bi->bi_db_open( c->be, &c->reply );
+					c->be->bd_info = bi_orig;
+				}
+			} else {
+				c->be->be_flags &= ~SLAP_DBFLAG_DISABLED;
+				rc = backend_startup_one( c->be, &c->reply );
+			}
+			break;
+
 		case CFG_IX_HASH64:
 			slap_hash64( 0 );
 			break;
@@ -2129,6 +2166,29 @@ sortval_reject:
 				SLAP_DBFLAGS(c->be) &= ~SLAP_DBFLAG_MONITORING;
 			break;
 
+		case CFG_DISABLED:
+			if ( c->bi ) {
+				if (c->value_int) {
+					if ( c->bi->bi_db_close ) {
+						BackendInfo *bi_orig = c->be->bd_info;
+						c->be->bd_info = c->bi;
+						c->bi->bi_db_close( c->be, &c->reply );
+						c->be->bd_info = bi_orig;
+					}
+					c->bi->bi_flags |= SLAPO_BFLAG_DISABLED;
+				} else {
+					c->bi->bi_flags &= ~SLAPO_BFLAG_DISABLED;
+				}
+			} else {
+				if (c->value_int) {
+					backend_shutdown( c->be );
+					SLAP_DBFLAGS(c->be) |= SLAP_DBFLAG_DISABLED;
+				} else {
+					SLAP_DBFLAGS(c->be) &= ~SLAP_DBFLAG_DISABLED;
+				}
+			}
+			break;
+
 		case CFG_HIDDEN:
 			if (c->value_int)
 				SLAP_DBFLAGS(c->be) |= SLAP_DBFLAG_HIDDEN;

servers/slapd/slap.h

@@ -1854,11 +1854,13 @@ struct BackendDB {
 #define SLAP_DBFLAG_ACL_ADD		0x20000U /* check attr ACLs on adds */
 #define SLAP_DBFLAG_SYNC_SUBENTRY	0x40000U /* use subentry for context */
 #define SLAP_DBFLAG_MULTI_SHADOW	0x80000U /* uses mirrorMode/multi-master */
+#define SLAP_DBFLAG_DISABLED	0x100000U
 	slap_mask_t	be_flags;
 #define SLAP_DBFLAGS(be)			((be)->be_flags)
 #define SLAP_NOLASTMOD(be)			(SLAP_DBFLAGS(be) & SLAP_DBFLAG_NOLASTMOD)
 #define SLAP_LASTMOD(be)			(!SLAP_NOLASTMOD(be))
 #define SLAP_DBHIDDEN(be)			(SLAP_DBFLAGS(be) & SLAP_DBFLAG_HIDDEN)
+#define SLAP_DBDISABLED(be)			(SLAP_DBFLAGS(be) & SLAP_DBFLAG_DISABLED)
 #define SLAP_DB_ONE_SUFFIX(be)		(SLAP_DBFLAGS(be) & SLAP_DBFLAG_ONE_SUFFIX)
 #define SLAP_ISOVERLAY(be)			(SLAP_DBFLAGS(be) & SLAP_DBFLAG_OVERLAY)
 #define SLAP_ISGLOBALOVERLAY(be)		(SLAP_DBFLAGS(be) & SLAP_DBFLAG_GLOBAL_OVERLAY)
@@ -2318,6 +2320,7 @@ struct BackendInfo {
 #define	SLAPO_BFLAG_SINGLE		0x01000000U
 #define	SLAPO_BFLAG_DBONLY		0x02000000U
 #define	SLAPO_BFLAG_GLOBONLY		0x04000000U
+#define	SLAPO_BFLAG_DISABLED		0x08000000U
 #define	SLAPO_BFLAG_MASK		0xFF000000U
 
 #define SLAP_BFLAGS(be)		((be)->bd_info->bi_flags)
@@ -2336,6 +2339,7 @@ struct BackendInfo {
 #define SLAPO_SINGLE(be)	(SLAP_BFLAGS(be) & SLAPO_BFLAG_SINGLE)
 #define SLAPO_DBONLY(be)	(SLAP_BFLAGS(be) & SLAPO_BFLAG_DBONLY)
 #define SLAPO_GLOBONLY(be)	(SLAP_BFLAGS(be) & SLAPO_BFLAG_GLOBONLY)
+#define SLAPO_DISABLED(be)	(SLAP_BFLAGS(be) & SLAPO_BFLAG_DISABLED)
 
 	char	**bi_controls;		/* supported controls */
 	char	bi_ctrls[SLAP_MAX_CIDS + 1];