Backglue hastily modified as an overlay

servers/slapd/overlays/glue.c

+/* glue.c - backend glue overlay */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2001-2004 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+/*
+ * Functions to glue a bunch of other backends into a single tree.
+ * All of the glued backends must share a common suffix. E.g., you
+ * can glue o=foo and ou=bar,o=foo but you can't glue o=foo and o=bar.
+ *
+ * The purpose of these functions is to allow you to split a single database
+ * into pieces (for load balancing purposes, whatever) but still be able
+ * to treat it as a single database after it's been split. As such, each
+ * of the glued backends should have identical rootdn.
+ *  -- Howard Chu
+ */
+
+#include "portable.h"
+
+#ifdef SLAPD_OVER_GLUE
+
+#include <stdio.h>
+
+#include <ac/string.h>
+#include <ac/socket.h>
+
+#define SLAPD_TOOLS
+#include "slap.h"
+
+typedef struct gluenode {
+	BackendDB *gn_be;
+	int	gn_bx;
+	struct berval gn_pdn;
+	int gn_async;
+} gluenode;
+
+typedef struct glueinfo {
+	int gi_nodes;
+	struct berval gi_pdn;
+	gluenode gi_n[1];
+} glueinfo;
+
+static slap_overinst	glue;
+
+static int glueMode;
+static BackendDB *glueBack;
+
+static slap_response glue_op_response;
+
+/* Just like select_backend, but only for our backends */
+static BackendDB *
+glue_back_select (
+	BackendDB *be,
+	struct berval *dn
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+	int i;
+
+	for (i = 0; i<gi->gi_nodes; i++) {
+		assert( gi->gi_n[i].gn_be->be_nsuffix );
+
+		if (dnIsSuffix(dn, &gi->gi_n[i].gn_be->be_nsuffix[0])) {
+			return gi->gi_n[i].gn_be;
+		}
+	}
+	be->bd_info = on->on_info->oi_orig;
+	return be;
+}
+
+
+typedef struct glue_state {
+	int err;
+	int slimit;
+	int matchlen;
+	char *matched;
+	int nrefs;
+	BerVarray refs;
+} glue_state;
+
+static int
+glue_op_response ( Operation *op, SlapReply *rs )
+{
+	glue_state *gs = op->o_callback->sc_private;
+
+	switch(rs->sr_type) {
+	case REP_SEARCH:
+		if ( gs->slimit != SLAP_NO_LIMIT
+				&& rs->sr_nentries >= gs->slimit )
+		{
+			rs->sr_err = gs->err = LDAP_SIZELIMIT_EXCEEDED;
+			return -1;
+		}
+		/* fallthru */
+	case REP_SEARCHREF:
+		return SLAP_CB_CONTINUE;
+
+	default:
+		if (rs->sr_err == LDAP_SUCCESS ||
+			rs->sr_err == LDAP_SIZELIMIT_EXCEEDED ||
+			rs->sr_err == LDAP_TIMELIMIT_EXCEEDED ||
+			rs->sr_err == LDAP_ADMINLIMIT_EXCEEDED ||
+			rs->sr_err == LDAP_NO_SUCH_OBJECT ||
+			gs->err != LDAP_SUCCESS)
+			gs->err = rs->sr_err;
+		if (gs->err == LDAP_SUCCESS && gs->matched) {
+			ch_free (gs->matched);
+			gs->matched = NULL;
+			gs->matchlen = 0;
+		}
+		if (gs->err != LDAP_SUCCESS && rs->sr_matched) {
+			int len;
+			len = strlen (rs->sr_matched);
+			if (len > gs->matchlen) {
+				if (gs->matched)
+					ch_free (gs->matched);
+				gs->matched = ch_strdup (rs->sr_matched);
+				gs->matchlen = len;
+			}
+		}
+		if (rs->sr_ref) {
+			int i, j, k;
+			BerVarray new;
+
+			for (i=0; rs->sr_ref[i].bv_val; i++);
+
+			j = gs->nrefs;
+			if (!j) {
+				new = ch_malloc ((i+1)*sizeof(struct berval));
+			} else {
+				new = ch_realloc(gs->refs,
+					(j+i+1)*sizeof(struct berval));
+			}
+			for (k=0; k<i; j++,k++) {
+				ber_dupbv( &new[j], &rs->sr_ref[k] );
+			}
+			new[j].bv_val = NULL;
+			gs->nrefs = j;
+			gs->refs = new;
+		}
+	}
+	return 0;
+}
+
+static int
+glue_op_search ( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+	BackendDB *b0 = op->o_bd;
+	BackendDB *b1 = NULL, *btmp;
+	BackendInfo *bi0 = op->o_bd->bd_info;
+	int i;
+	long stoptime = 0;
+	glue_state gs = {0, 0, 0, NULL, 0, NULL};
+	slap_callback cb = { NULL, glue_op_response, NULL, NULL };
+	int scope0, slimit0, tlimit0;
+	struct berval dn, ndn, *pdn;
+
+	cb.sc_private = &gs;
+
+	cb.sc_next = op->o_callback;
+
+	stoptime = slap_get_time () + op->ors_tlimit;
+
+	op->o_bd = glue_back_select (b0, &op->o_req_ndn);
+	b0->bd_info = on->on_info->oi_orig;
+
+	switch (op->ors_scope) {
+	case LDAP_SCOPE_BASE:
+		return SLAP_CB_CONTINUE;
+
+	case LDAP_SCOPE_ONELEVEL:
+	case LDAP_SCOPE_SUBTREE:
+#ifdef LDAP_SCOPE_SUBORDINATE
+	case LDAP_SCOPE_SUBORDINATE: /* FIXME */
+#endif
+
+		if ( op->o_sync ) {
+			if (op->o_bd && op->o_bd->be_search) {
+				rs->sr_err = op->o_bd->be_search( op, rs );
+			} else {
+				send_ldap_error(op, rs, LDAP_UNWILLING_TO_PERFORM,
+						"No search target found");
+			}
+			return rs->sr_err;
+		}
+
+		op->o_callback = &cb;
+		rs->sr_err = gs.err = LDAP_UNWILLING_TO_PERFORM;
+		scope0 = op->ors_scope;
+		slimit0 = gs.slimit = op->ors_slimit;
+		tlimit0 = op->ors_tlimit;
+		dn = op->o_req_dn;
+		ndn = op->o_req_ndn;
+		b1 = op->o_bd;
+
+		/*
+		 * Execute in reverse order, most general first 
+		 */
+		for (i = gi->gi_nodes; i >= 0; i--) {
+			if ( i == gi->gi_nodes ) {
+				btmp = b0;
+				pdn = &gi->gi_pdn;
+			} else {
+				btmp = gi->gi_n[i].gn_be;
+				pdn = &gi->gi_n[i].gn_pdn;
+			}
+			if (!btmp || !btmp->be_search)
+				continue;
+			if (!dnIsSuffix(&btmp->be_nsuffix[0], &b1->be_nsuffix[0]))
+				continue;
+			if (tlimit0 != SLAP_NO_LIMIT) {
+				op->ors_tlimit = stoptime - slap_get_time ();
+				if (op->ors_tlimit <= 0) {
+					rs->sr_err = gs.err = LDAP_TIMELIMIT_EXCEEDED;
+					break;
+				}
+			}
+			if (slimit0 != SLAP_NO_LIMIT) {
+				op->ors_slimit = slimit0 - rs->sr_nentries;
+				if (op->ors_slimit < 0) {
+					rs->sr_err = gs.err = LDAP_SIZELIMIT_EXCEEDED;
+					break;
+				}
+			}
+			rs->sr_err = 0;
+			/*
+			 * check for abandon 
+			 */
+			if (op->o_abandon) {
+				goto end_of_loop;
+			}
+			op->o_bd = btmp;
+
+			assert( op->o_bd->be_suffix );
+			assert( op->o_bd->be_nsuffix );
+			
+			if (scope0 == LDAP_SCOPE_ONELEVEL && 
+				dn_match(pdn, &ndn))
+			{
+				op->ors_scope = LDAP_SCOPE_BASE;
+				op->o_req_dn = op->o_bd->be_suffix[0];
+				op->o_req_ndn = op->o_bd->be_nsuffix[0];
+				rs->sr_err = op->o_bd->be_search(op, rs);
+
+			} else if (scope0 == LDAP_SCOPE_SUBTREE &&
+				dn_match(&op->o_bd->be_nsuffix[0], &ndn))
+			{
+				rs->sr_err = op->o_bd->be_search( op, rs );
+
+			} else if (scope0 == LDAP_SCOPE_SUBTREE &&
+				dnIsSuffix(&op->o_bd->be_nsuffix[0], &ndn))
+			{
+				op->o_req_dn = op->o_bd->be_suffix[0];
+				op->o_req_ndn = op->o_bd->be_nsuffix[0];
+				rs->sr_err = op->o_bd->be_search( op, rs );
+				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+					gs.err = LDAP_SUCCESS;
+				}
+
+			} else if (dnIsSuffix(&ndn, &op->o_bd->be_nsuffix[0])) {
+				rs->sr_err = op->o_bd->be_search( op, rs );
+			}
+
+			switch ( gs.err ) {
+
+			/*
+			 * Add errors that should result in dropping
+			 * the search
+			 */
+			case LDAP_SIZELIMIT_EXCEEDED:
+			case LDAP_TIMELIMIT_EXCEEDED:
+			case LDAP_ADMINLIMIT_EXCEEDED:
+			case LDAP_NO_SUCH_OBJECT:
+				goto end_of_loop;
+			
+			default:
+				break;
+			}
+		}
+end_of_loop:;
+		op->ors_scope = scope0;
+		op->ors_slimit = slimit0;
+		op->ors_tlimit = tlimit0;
+		op->o_req_dn = dn;
+		op->o_req_ndn = ndn;
+
+		break;
+	}
+	if ( !op->o_abandon ) {
+		op->o_callback = cb.sc_next;
+		rs->sr_err = gs.err;
+		rs->sr_matched = gs.matched;
+		rs->sr_ref = gs.refs;
+
+		send_ldap_result( op, rs );
+	}
+
+	op->o_bd = b0;
+	op->o_bd->bd_info = bi0;
+	if (gs.matched)
+		free (gs.matched);
+	if (gs.refs)
+		ber_bvarray_free(gs.refs);
+	return rs->sr_err;
+}
+
+static BackendDB toolDB;
+
+static int
+glue_tool_entry_open (
+	BackendDB *b0,
+	int mode
+)
+{
+	slap_overinfo	*oi = (slap_overinfo *)b0->bd_info;
+
+	/* We don't know which backend to talk to yet, so just
+	 * remember the mode and move on...
+	 */
+
+	glueMode = mode;
+	glueBack = NULL;
+	toolDB = *b0;
+	toolDB.bd_info = oi->oi_orig;
+
+	return 0;
+}
+
+static int
+glue_tool_entry_close (
+	BackendDB *b0
+)
+{
+	int rc = 0;
+
+	if (glueBack) {
+		if (!glueBack->be_entry_close)
+			return 0;
+		rc = glueBack->be_entry_close (glueBack);
+	}
+	return rc;
+}
+
+static slap_overinst *
+glue_tool_inst(
+	BackendInfo *bi
+)
+{
+	slap_overinfo	*oi = (slap_overinfo *)bi;
+	slap_overinst	*on;
+
+	for ( on = oi->oi_list; on; on=on->on_next ) {
+		if ( !strcmp( on->on_bi.bi_type, glue.on_bi.bi_type ))
+			return on;
+	}
+	return NULL;
+}
+
+/* This function will only be called in tool mode */
+static int
+glue_open (
+	BackendInfo *bi
+)
+{
+	slap_overinst *on = glue_tool_inst( bi );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i, rc = 0;
+
+	/* If we were invoked in tool mode, open all the underlying backends */
+	if (slapMode & SLAP_TOOL_MODE) {
+		for ( i=0; i<gi->gi_nodes; i++ ) {
+			gi->gi_n[i].gn_be = backendDB + gi->gi_n[i].gn_bx;
+			rc = backend_startup( gi->gi_n[i].gn_be );
+			if ( rc ) break;
+		}
+	} /* other case is impossible */
+	return rc;
+}
+
+/* This function will only be called in tool mode */
+static int
+glue_close (
+	BackendInfo *bi
+)
+{
+	slap_overinst *on = glue_tool_inst( bi );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i, rc = 0;
+
+	if (slapMode & SLAP_TOOL_MODE) {
+		for ( i=0; i<gi->gi_nodes; i++ ) {
+			rc = backend_shutdown( gi->gi_n[i].gn_be );
+			if ( rc ) break;
+		}
+	}
+	return rc;
+}
+
+static ID
+glue_tool_entry_first (
+	BackendDB *b0
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i;
+
+	/* If we're starting from scratch, start at the most general */
+	if (!glueBack) {
+		if ( toolDB.be_entry_open && toolDB.be_entry_first ) {
+			glueBack = &toolDB;
+		} else {
+			for (i = gi->gi_nodes-1; i >= 0; i--) {
+				if (gi->gi_n[i].gn_be->be_entry_open &&
+					gi->gi_n[i].gn_be->be_entry_first) {
+						glueBack = gi->gi_n[i].gn_be;
+					break;
+				}
+			}
+		}
+	}
+	if (!glueBack || !glueBack->be_entry_open || !glueBack->be_entry_first ||
+		glueBack->be_entry_open (glueBack, glueMode) != 0)
+		return NOID;
+
+	return glueBack->be_entry_first (glueBack);
+}
+
+static ID
+glue_tool_entry_next (
+	BackendDB *b0
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i;
+	ID rc;
+
+	if (!glueBack || !glueBack->be_entry_next)
+		return NOID;
+
+	rc = glueBack->be_entry_next (glueBack);
+
+	/* If we ran out of entries in one database, move on to the next */
+	while (rc == NOID) {
+		if ( glueBack && glueBack->be_entry_close )
+			glueBack->be_entry_close (glueBack);
+		for (i=0; i<gi->gi_nodes; i++) {
+			if (gi->gi_n[i].gn_be == glueBack)
+				break;
+		}
+		if (i == 0) {
+			glueBack = NULL;
+			break;
+		} else {
+			glueBack = gi->gi_n[i-1].gn_be;
+			rc = glue_tool_entry_first (b0);
+		}
+	}
+	return rc;
+}
+
+static Entry *
+glue_tool_entry_get (
+	BackendDB *b0,
+	ID id
+)
+{
+	if (!glueBack || !glueBack->be_entry_get)
+		return NULL;
+
+	return glueBack->be_entry_get (glueBack, id);
+}
+
+static ID
+glue_tool_entry_put (
+	BackendDB *b0,
+	Entry *e,
+	struct berval *text
+)
+{
+	BackendDB *be, b2;
+	int rc;
+
+	b2 = *b0;
+	b2.bd_info = (BackendInfo *)glue_tool_inst( b0->bd_info );
+	be = glue_back_select (&b2, &e->e_nname);
+	if ( be == &b2 ) be = &toolDB;
+
+	if (!be->be_entry_put)
+		return NOID;
+
+	if (!glueBack) {
+		rc = be->be_entry_open (be, glueMode);
+		if (rc != 0)
+			return NOID;
+	} else if (be != glueBack) {
+		/* If this entry belongs in a different branch than the
+		 * previous one, close the current database and open the
+		 * new one.
+		 */
+		glueBack->be_entry_close (glueBack);
+		rc = be->be_entry_open (be, glueMode);
+		if (rc != 0)
+			return NOID;
+	}
+	glueBack = be;
+	return be->be_entry_put (be, e, text);
+}
+
+static int
+glue_tool_entry_reindex (
+	BackendDB *b0,
+	ID id
+)
+{
+	if (!glueBack || !glueBack->be_entry_reindex)
+		return -1;
+
+	return glueBack->be_entry_reindex (glueBack, id);
+}
+
+static int
+glue_tool_sync (
+	BackendDB *b0
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i;
+
+	/* just sync everyone */
+	for (i = 0; i<gi->gi_nodes; i++)
+		if (gi->gi_n[i].gn_be->be_sync)
+			gi->gi_n[i].gn_be->be_sync (gi->gi_n[i].gn_be);
+	return 0;
+}
+
+static int
+glue_db_init(
+	BackendDB *be
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	slap_overinfo	*oi = on->on_info;
+	glueinfo *gi;
+
+	gi = ch_calloc( 1, sizeof(glueinfo));
+	on->on_bi.bi_private = gi;
+	dnParent( be->be_nsuffix, &gi->gi_pdn );
+
+	/* Currently the overlay framework doesn't handle these entry points
+	 * but we need them....
+	 */
+	oi->oi_bi.bi_open = glue_open;
+	oi->oi_bi.bi_close = glue_close;
+
+	oi->oi_bi.bi_tool_entry_open = glue_tool_entry_open;
+	oi->oi_bi.bi_tool_entry_close = glue_tool_entry_close;
+	oi->oi_bi.bi_tool_entry_first = glue_tool_entry_first;
+	oi->oi_bi.bi_tool_entry_next = glue_tool_entry_next;
+	oi->oi_bi.bi_tool_entry_get = glue_tool_entry_get;
+	oi->oi_bi.bi_tool_entry_put = glue_tool_entry_put;
+	oi->oi_bi.bi_tool_entry_reindex = glue_tool_entry_reindex;
+	oi->oi_bi.bi_tool_sync = glue_tool_sync;
+
+	/*FIXME : need to add support */
+	oi->oi_bi.bi_tool_dn2id_get = 0;
+	oi->oi_bi.bi_tool_id2entry_get = 0;
+	oi->oi_bi.bi_tool_entry_modify = 0;
+
+	return 0;
+}
+
+static int
+glue_db_destroy (
+	BackendDB *be
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+
+	free (gi);
+	return SLAP_CB_CONTINUE;
+}
+
+static int
+glue_db_open (
+	BackendDB *be
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+	int i;
+
+	for ( i=0; i<gi->gi_nodes; i++ ) {
+		gi->gi_n[i].gn_be = backendDB + gi->gi_n[i].gn_bx;
+	}
+	return 0;
+}
+
+static int
+glue_db_config(