/* expandUrl.c : overlay to expand uri attributes */
/* Copyright 2005 INRIA Sophia Antipolis */
/* All rights reserved. */
/* Authors : Sebastien Georget <mailto:sebastien@georget.name */
/*
 * 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>.
*/

/* ACKNOWLEDGEMENTS:
 * This work is based on the 'collect.c - Demonstration of overlay code'
 * part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * This work was initially developed by the Howard Chu for inclusion
 * in OpenLDAP Software.
 */

/* SYNTAX
 * In slapd.conf :
 *   moduleload expandUrl
 *   overlay expandUrl
 *   expandUrl dn attr1 attr2
 *
 * The 3 parameters are :
 *  - dn : the overlay will only operate on this dn
 *  - attr1 : the overlay will look for URIs in this attribute
 *            only the dn part of the uri is used
 *  - attr2 : if target URIs contain this attribute the
 *            values are merged in dn
 */

/* EXAMPLE
 * ***
 * # test.ldif
 * dn: cn=test,ou=Group,dc=test
 * memberURL: ldap:///cn=test,ou=Group,o=org1,dc=test
 * memberURL: ldap:///cn=test,ou=Group,o=org2,dc=test
 * 
 * dn: cn=test,ou=Group,o=org1,dc=test
 * memberUid: bob
 * 
 * dn: cn=test,ou=Group,o=org2,dc=test
 * memberUid: alice
 * ***
 * 
 * ldapsearch -x -b "ou=Group,dc=test" will return
 * dn: cn=test,ou=Group,dc=test
 * memberURL: ldap:///cn=test,ou=Group,o=org1,dc=test
 * memberURL: ldap:///cn=test,ou=Group,o=org2,dc=test
 * memberUid: bob
 * memberUid: alice 
*/

/* CHANGELOG
	v 0.2 : if no entry is found, check if filters contain the
            expanded attribute and redo the search on expanded entry
            if necessary
	v 0.1 : correctly expand attributes if the entry is found
*/

#include "portable.h"

// #ifdef SLAPD_OVER_EXPANDURL

#include <stdio.h>

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

#include "slap.h"


typedef struct expandUrl_info {
	struct expandUrl_info *eui_next;
	struct berval eui_dn;
	AttributeDescription *eui_aduri;
	AttributeDescription *eui_adattr;
	int expanded;
} expandUrl_info;


int expand_entry (Operation * op, expandUrl_info * eui, Entry * e) {
	BerVarray vals = NULL;
	int rc, n;
	int cache = op->o_do_not_cache;
	op->o_do_not_cache = 1;


	Debug(LDAP_DEBUG_CONFIG, "expandUrl: expanding %s\n", \
		e->e_name.bv_val, 0, 0);

	rc = backend_attribute( op, NULL, &eui->eui_dn, eui->eui_aduri, &vals, ACL_READ );

	if (vals)
	{
		for (n = 0; !BER_BVISNULL( &(vals)[n] ); n++ ) {
			BerVarray target_vals = NULL;
			int target_rc;
			struct berval target_bv, target_dn;

			LDAPURLDesc *ludp;
			if ( ldap_url_parse( vals[n].bv_val, &ludp ) != LDAP_URL_SUCCESS )
			{
				Debug(LDAP_DEBUG_CONFIG, "expandUrl: invalid uri (%s)\n", vals[n].bv_val, 0, 0);
				continue;
			}
			ber_str2bv( ludp->lud_dn, 0, 0, &target_bv );
			if ( dnNormalize( 0, NULL, NULL, &target_bv, &target_dn, NULL ) ) {
				Debug(LDAP_DEBUG_CONFIG, "expandUrl: couldn't normalize uri \n", 0, 0, 0);
				continue;
			}

			Debug(LDAP_DEBUG_CONFIG, "expandUrl: search %s in %s\n", \
					eui->eui_adattr->ad_cname.bv_val, target_dn.bv_val, 0);
			target_rc = backend_attribute( op, NULL, &target_dn, eui->eui_adattr, &target_vals, ACL_READ );
			if (target_rc != LDAP_SUCCESS) continue;

			/* If there are any values, merge them into the
			 * current entry
			 */
			if ( target_vals ) {
				attr_merge( e, eui->eui_adattr, target_vals, NULL );
				ber_bvarray_free_x( vals, op->o_tmpmemctx );
			}
		}
	}
	op->o_do_not_cache = cache;
}

static int
expandUrl_response( Operation *op, SlapReply *rs )
{
	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
	expandUrl_info *eui = on->on_bi.bi_private;

	/* If we've been configured and the current response is
	 * a search entry
	 */
	if ( eui && rs->sr_type == REP_SEARCH ) {
		Entry *new = NULL;

		op->o_bd->bd_info = (BackendInfo *)on->on_info;

		for (; eui; eui=eui->eui_next ) {
			/* have we been called already ? */
			if (eui->expanded) {
				eui->expanded = 0;
				return SLAP_CB_CONTINUE;
			}

			/* If this entry match the configured one */
			if ( strcmp(rs->sr_entry->e_nname.bv_val, eui->eui_dn.bv_val) ) continue;

			/* Extract the values of the uri attribute from
			 * the configured entry
			 */
			new = entry_dup( rs->sr_entry );
			expand_entry (op, eui, new);
		}

		if ( new ) {
			rs->sr_entry = new;
			rs->sr_flags |= REP_ENTRY_MUSTBEFREED;
		}
	}
	/* is this the result of a search ? */
	/* and does it contains our attribute ? */
	if ( eui && op->o_tag == LDAP_REQ_SEARCH && \
		rs->sr_type == REP_RESULT && \
		strstr(op->ors_filterstr.bv_val, eui->eui_adattr->ad_cname.bv_val) != NULL) {

		/* have we been called already ? */
		if (eui->expanded) return SLAP_CB_CONTINUE;

		Debug(LDAP_DEBUG_CONFIG, "expandUrl: filters contain %s\n", eui->eui_adattr->ad_cname.bv_val, 0, 0);
		Entry * new = NULL;
		op->o_bd = select_backend( &(eui->eui_dn), 0, 0 );
		int rc = be_entry_get_rw(op, &(eui->eui_dn), NULL, NULL, 0, &new);
		new = entry_dup( new );
		expand_entry (op, eui, new);

		int err = test_filter( op, new, op->ors_filter );
		if( err == LDAP_COMPARE_TRUE ) {
			rs->sr_entry = new;
	                rs->sr_flags |= REP_ENTRY_MUSTBEFREED;
			eui->expanded = 1;
	                send_search_entry(op, rs);
		}
	}
	/* Default is to just fall through to the normal processing */
	return SLAP_CB_CONTINUE;
}

static int expandUrl_config(
    BackendDB	*be,
    const char	*fname,
    int		lineno,
    int		argc,
    char	**argv
)
{
	slap_overinst *on = (slap_overinst *) be->bd_info;
	AttributeDescription *ad_uri = NULL, *ad_attr = NULL;

	/* The config syntax is "expandUrl <dn> <attribute-description>"
	 * and only one directive may be speeuified per overlay instance.
	 */

	if ( strcasecmp( argv[0], "expandUrl" ) == 0 ) {
		expandUrl_info *eui;
		struct berval bv, dn;
		const char *text;
		if ( argc != 4 ) {
			Debug( LDAP_DEBUG_ANY,
		"%s: line %d: argument missing in \"expandUrl <dn> <expandable-attribute> <expanded-attribute\" line.\n",
			fname, lineno, 0 );
		    	return( 1 );
		}
		ber_str2bv( argv[1], 0, 0, &bv );
		if ( dnNormalize( 0, NULL, NULL, &bv, &dn, NULL ) ) {
			Debug( LDAP_DEBUG_ANY,
		"%s: line %d: invalid DN in \"expandUrl\" line: %s.\n",
			fname, lineno, text );
			return( 1 );
		}
		if ( slap_str2ad( argv[2], &ad_uri, &text ) ) {
			Debug( LDAP_DEBUG_ANY,
		"%s: line %d: attribute description unknown in \"expandUrl\" line: %s.\n",
			fname, lineno, text );
			return( 1 );
		}
		if ( slap_str2ad( argv[3], &ad_attr, &text ) ) {
			Debug( LDAP_DEBUG_ANY,
		"%s: line %d: attribute description unknown in \"expandUrl\" line: %s.\n",
			fname, lineno, text );
			return( 1 );
		}

		/* The on->on_bi.bi_private pointer can be used for
		 * anything this instance of the overlay needs.
		 */
		eui = ch_malloc( sizeof( expandUrl_info ));
		eui->eui_aduri = ad_uri;
		eui->eui_adattr = ad_attr;
		eui->eui_dn = dn;
		eui->expanded = 0;
		eui->eui_next = on->on_bi.bi_private;
		on->on_bi.bi_private = eui;
		return 0;
	}
	return SLAP_CONF_UNKNOWN;
}

static slap_overinst expandUrl;

int expandUrl_init() {
	expandUrl.on_bi.bi_type = "expandUrl";
	expandUrl.on_bi.bi_db_config = expandUrl_config;
	expandUrl.on_response = expandUrl_response;

	return overlay_register( &expandUrl );
}

// #if SLAPD_OVER_EXPANDURL == SLAPD_MOD_DYNAMIC
int init_module(int argc, char *argv[]) {
	return expandUrl_init();
}
// #endif

// #endif /* SLAPD_OVER_EXPANDURL */