/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 1999-2004 The OpenLDAP Foundation.
 * Portions Copyright 2001-2003 Pierangelo Masarati.
 * Portions Copyright 1999-2003 Howard Chu.
 * 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>.
 */
/* ACKNOWLEDGEMENTS:
 * This work was initially developed by the Howard Chu for inclusion
 * in OpenLDAP Software and subsequently enhanced by Pierangelo
 * Masarati.
 */

#include "portable.h"

#include <stdio.h>

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

#include "slap.h"
#include "../back-ldap/back-ldap.h"
#include "back-meta.h"
#undef ldap_debug	/* silence a warning in ldap-int.h */
#include "ldap_log.h"
#include "../../../libraries/libldap/ldap-int.h"

static int
meta_send_entry(
		Operation 	*op,
		SlapReply	*rs,
		struct metaconn	*lc,
		int 		i,
		LDAPMessage 	*e
);

int
meta_back_search( Operation *op, SlapReply *rs )
{
	struct metainfo	*li = ( struct metainfo * )op->o_bd->be_private;
	struct metaconn *lc;
	struct metasingleconn *lsc;
	struct timeval	tv = { 0, 0 };
	LDAPMessage	*res = NULL, *e;
	int	rc = 0, *msgid, sres = LDAP_SUCCESS;
	char *err = NULL;
	struct berval match = BER_BVNULL, mmatch = BER_BVNULL;
	BerVarray v2refs = NULL;
		
	int i, last = 0, candidates = 0, initial_candidates = 0,
			candidate_match = 0;
	dncookie dc;

	int	is_scope = 0,
		is_filter = 0;

	/*
	 * controls are set in ldap_back_dobind()
	 * 
	 * FIXME: in case of values return filter, we might want
	 * to map attrs and maybe rewrite value
	 */
	lc = meta_back_getconn( op, rs, META_OP_ALLOW_MULTIPLE, 
			&op->o_req_ndn, NULL );
	if ( !lc ) {
 		send_ldap_result( op, rs );
		return -1;
	}

	if ( !meta_back_dobind( lc, op ) ) {
		rs->sr_err = LDAP_OTHER;
 		send_ldap_result( op, rs );
		return -1;
	}

	/*
	 * Array of message id of each target
	 */
	msgid = ch_calloc( sizeof( int ), li->ntargets );
	if ( msgid == NULL ) {
		rs->sr_err = LDAP_OTHER;
 		send_ldap_result( op, rs );
		return -1;
	}
	
	dc.conn = op->o_conn;
	dc.rs = rs;

	/*
	 * Inits searches
	 */
	for ( i = 0, lsc = lc->conns; !META_LAST(lsc); ++i, ++lsc ) {
		struct berval	realbase = op->o_req_dn;
		int		realscope = op->ors_scope;
		ber_len_t	suffixlen = 0;
		struct berval	mbase = BER_BVNULL; 
		struct berval	mfilter = BER_BVNULL;
		char		**mapped_attrs = NULL;

		if ( lsc->candidate != META_CANDIDATE ) {
			msgid[ i ] = -1;
			continue;
		}

		/* should we check return values? */
		if ( op->ors_deref != -1 ) {
			ldap_set_option( lsc->ld, LDAP_OPT_DEREF,
					( void * )&op->ors_deref);
		}
		if ( op->ors_tlimit != SLAP_NO_LIMIT ) {
			ldap_set_option( lsc->ld, LDAP_OPT_TIMELIMIT,
					( void * )&op->ors_tlimit);
		}
		if ( op->ors_slimit != SLAP_NO_LIMIT ) {
			ldap_set_option( lsc->ld, LDAP_OPT_SIZELIMIT,
					( void * )&op->ors_slimit);
		}

		dc.rwmap = &li->targets[ i ]->rwmap;

		/*
		 * modifies the base according to the scope, if required
		 */
		suffixlen = li->targets[ i ]->suffix.bv_len;
		if ( suffixlen > op->o_req_ndn.bv_len ) {
			switch ( op->ors_scope ) {
			case LDAP_SCOPE_SUBTREE:
				/*
				 * make the target suffix the new base
				 * FIXME: this is very forgiving, because
				 * illegal bases may be turned into 
				 * the suffix of the target.
				 */
				if ( dnIsSuffix( &li->targets[ i ]->suffix,
						&op->o_req_ndn ) ) {
					realbase = li->targets[ i ]->suffix;
					is_scope++;

				} else {
					/*
					 * this target is no longer candidate
					 */
					msgid[ i ] = -1;
					goto new_candidate;
				}
				break;

			case LDAP_SCOPE_ONELEVEL:
			{
				struct berval	rdn = li->targets[ i ]->suffix;
				rdn.bv_len -= op->o_req_ndn.bv_len + STRLENOF( "," );
				if ( dnIsOneLevelRDN( &rdn )
						&& dnIsSuffix( &li->targets[ i ]->suffix, &op->o_req_ndn ) )
				{
					/*
					 * if there is exactly one level,
					 * make the target suffix the new
					 * base, and make scope "base"
					 */
					realbase = li->targets[ i ]->suffix;
					realscope = LDAP_SCOPE_BASE;
					is_scope++;
					break;
				} /* else continue with the next case */
			}

			case LDAP_SCOPE_BASE:
				/*
				 * this target is no longer candidate
				 */
				msgid[ i ] = -1;
				goto new_candidate;
			}

		} else {
			is_scope++;
		}

		/*
		 * Rewrite the search base, if required
		 */
		dc.ctx = "searchBase";
		switch ( ldap_back_dn_massage( &dc, &realbase, &mbase ) ) {
		default:
			break;

		case REWRITE_REGEXEC_UNWILLING:
			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
			rs->sr_text = "Operation not allowed";
			send_ldap_result( op, rs );
			rc = -1;
			goto finish;

		case REWRITE_REGEXEC_ERR:
#if 0
			rs->sr_err = LDAP_OTHER;
			rs->sr_text = "Rewrite error";
			send_ldap_result( op, rs );
			rc = -1;
			goto finish;
#endif 

			/*
			 * this target is no longer candidate
			 */
			msgid[ i ] = -1;
			goto new_candidate;
		}

		/*
		 * Maps filter
		 */
		rc = ldap_back_filter_map_rewrite( &dc,
				op->ors_filter,
				&mfilter, BACKLDAP_MAP );
		switch ( rc ) {
		case LDAP_SUCCESS:
			is_filter++;
			break;

		case LDAP_COMPARE_FALSE:
			rc = 0;

		default:
			/*
			 * this target is no longer candidate
			 */
			msgid[ i ] = -1;
			goto new_candidate;
		}

		/*
		 * Maps required attributes
		 */
		rc = ldap_back_map_attrs( &li->targets[ i ]->rwmap.rwm_at,
				op->ors_attrs, BACKLDAP_MAP,
				&mapped_attrs );
		if ( rc != LDAP_SUCCESS ) {
			/*
			 * this target is no longer candidate
			 */
			msgid[ i ] = -1;
			goto new_candidate;
		}

		/*
		 * Starts the search
		 */
		msgid[ i ] = ldap_search( lsc->ld, mbase.bv_val, realscope,
				mfilter.bv_val, mapped_attrs,
				op->ors_attrsonly ); 
		if ( mapped_attrs ) {
			free( mapped_attrs );
			mapped_attrs = NULL;
		}
		if ( mfilter.bv_val != op->ors_filterstr.bv_val ) {
			free( mfilter.bv_val );
			mfilter.bv_val = NULL;
		}
		if ( mbase.bv_val != realbase.bv_val ) {
			free( mbase.bv_val );
			mbase.bv_val = NULL;
		}

		if ( msgid[ i ] == -1 ) {
			continue;
		}

		++candidates;

new_candidate:;
	}

	initial_candidates = candidates;

	/* We pull apart the ber result, stuff it into a slapd entry, and
	 * let send_search_entry stuff it back into ber format. Slow & ugly,
	 * but this is necessary for version matching, and for ACL processing.
	 */


	/*
	 * In case there are no candidates, no cycle takes place...
	 *
	 * FIXME: we might use a queue, to balance the load 
	 * among the candidates
	 */
	for ( rc = 0; candidates > 0; ) {
		int ab, gotit = 0;

		/* check for abandon */
		ab = op->o_abandon;

		for ( i = 0, lsc = lc->conns; !META_LAST(lsc); lsc++, i++ ) {
			if ( msgid[ i ] == -1 ) {
				continue;
			}
			
			if ( ab ) {
				ldap_abandon( lsc->ld, msgid[ i ] );
				rc = 0;
				break;
			}

			if ( op->ors_slimit > 0
					&& rs->sr_nentries == op->ors_slimit ) {
				rs->sr_err = LDAP_SIZELIMIT_EXCEEDED;
				rs->sr_v2ref = v2refs;
				send_ldap_result( op, rs );
				goto finish;
			}

			/*
			 * FIXME: handle time limit as well?
			 * Note that target servers are likely 
			 * to handle it, so at some time we'll
			 * get a LDAP_TIMELIMIT_EXCEEDED from
			 * one of them ...
			 */
			rc = ldap_result( lsc->ld, msgid[ i ],
					0, &tv, &res );

			if ( rc == 0 ) {
				/* timeout exceeded */

				/* FIXME: res should not need to be freed */
				assert( res == NULL );

				continue;

			} else if ( rc == -1 ) {
				/* something REALLY bad happened! */
				( void )meta_clear_unused_candidates( li,
						lc, -1, 0 );
				rs->sr_err = LDAP_OTHER;
				rs->sr_v2ref = v2refs;
				send_ldap_result( op, rs );
				
				/* anything else needs be done? */

				/* FIXME: res should not need to be freed */
				assert( res == NULL );

				goto finish;

			} else if ( rc == LDAP_RES_SEARCH_ENTRY ) {
				e = ldap_first_entry( lsc->ld, res );
				meta_send_entry( op, rs, lc, i, e );

				ldap_msgfree( res );
				res = NULL;

				/*
				 * If scope is BASE, we need to jump out
				 * as soon as one entry is found; if
				 * the target pool is properly crafted,
				 * this should correspond to the sole
				 * entry that has the base DN
				 */
				if ( op->ors_scope == LDAP_SCOPE_BASE
						&& rs->sr_nentries > 0 ) {
					candidates = 0;
					sres = LDAP_SUCCESS;
					break;
				}

				gotit = 1;

			} else if ( rc == LDAP_RES_SEARCH_REFERENCE ) {
				char		**references = NULL;
				int		cnt;

				rc = ldap_parse_reference( lsc->ld, res,
						&references, &rs->sr_ctrls, 1 );
				res = NULL;

				if ( rc != LDAP_SUCCESS ) {
					continue;
				}

				if ( references == NULL ) {
					continue;
				}

#ifdef ENABLE_REWRITE
				dc.ctx = "referralDN";
#else /* ! ENABLE_REWRITE */
				dc.tofrom = 0;
				dc.normalized = 0;
#endif /* ! ENABLE_REWRITE */
				for ( cnt = 0; references[ cnt ]; cnt++ )
					;

				rs->sr_ref = ch_calloc( sizeof( struct berval ), cnt + 1 );

				for ( cnt = 0; references[ cnt ]; cnt++ ) {
					ber_str2bv( references[ cnt ], 0, 1, &rs->sr_ref[ cnt ] );
				}
				BER_BVZERO( &rs->sr_ref[ cnt ] );

				( void )ldap_back_referral_result_rewrite( &dc, rs->sr_ref );

				if ( rs->sr_ref != NULL && !BER_BVISNULL( &rs->sr_ref[ 0 ] ) ) {
					/* ignore return value by now */
					( void )send_search_reference( op, rs );

					ber_bvarray_free( rs->sr_ref );
					rs->sr_ref = NULL;
				}

				/* cleanup */
				if ( references ) {
					ldap_value_free( references );
				}

				if ( rs->sr_ctrls ) {
					ldap_controls_free( rs->sr_ctrls );
					rs->sr_ctrls = NULL;
				}

			} else {
				rs->sr_err = ldap_result2error( lsc->ld,
						res, 1 );
				res = NULL;

				sres = slap_map_api2result( rs );
				if ( err != NULL ) {
					free( err );
				}
				ldap_get_option( lsc->ld,
						LDAP_OPT_ERROR_STRING, &err );
				if ( match.bv_val != NULL ) {
					free( match.bv_val );
				}
				ldap_get_option( lsc->ld,
						LDAP_OPT_MATCHED_DN, &match.bv_val );

				Debug( LDAP_DEBUG_ANY,
					"=>meta_back_search [%d] "
					"match=\"%s\" err=\"%s\"\n",
     					i, match.bv_val, err );	
				candidate_match++;
				last = i;
				rc = 0;

				/*
				 * When no candidates are left,
				 * the outer cycle finishes
				 */
				msgid[ i ] = -1;
				--candidates;
			}
		}

		if ( ab ) {
			goto finish;
		}

		if ( gotit == 0 ) {
			tv.tv_sec = 0;
                        tv.tv_usec = 100000;
                        ldap_pvt_thread_yield();
		} else {
			tv.tv_sec = 0;
			tv.tv_usec = 0;
		}
	}

	if ( rc == -1 ) {
		/*
		 * FIXME: need a strategy to handle errors
		 */
		rc = meta_back_op_result( lc, op, rs );
		goto finish;
	}

	/*
	 * Rewrite the matched portion of the search base, if required
	 * 
	 * FIXME: only the last one gets caught!
	 */
	if ( candidate_match == initial_candidates
			&& match.bv_val != NULL && *match.bv_val ) {
		dc.ctx = "matchedDN";
		dc.rwmap = &li->targets[ last ]->rwmap;

		if ( ldap_back_dn_massage( &dc, &match, &mmatch ) ) {
			mmatch.bv_val = NULL;
		}
	}

	/*
	 * In case we returned at least one entry, we return LDAP_SUCCESS
	 * otherwise, the latter error code we got
	 *
	 * FIXME: we should handle error codes and return the more 
	 * important/reasonable
	 */
	if ( is_scope == 0 ) {
		sres = LDAP_NO_SUCH_OBJECT;
	}

	if ( sres == LDAP_SUCCESS && v2refs ) {
		sres = LDAP_REFERRAL;
	}
	rs->sr_err = sres;
	rs->sr_matched = mmatch.bv_val;
	rs->sr_v2ref = v2refs;
	send_ldap_result( op, rs );
	rs->sr_matched = NULL;
	rs->sr_v2ref = NULL;


finish:;
	if ( match.bv_val ) {
		if ( mmatch.bv_val != match.bv_val ) {
			free( mmatch.bv_val );
		}
		free( match.bv_val );
	}
	
	if ( err ) {
		free( err );
	}
	
	if ( msgid ) {
		ch_free( msgid );
	}

	return rc;
}

static int
meta_send_entry(
		Operation 	*op,
		SlapReply	*rs,
		struct metaconn *lc,
		int 		target,
		LDAPMessage 	*e
)
{
	struct metainfo 	*li = ( struct metainfo * )op->o_bd->be_private;
	struct berval		a, mapped;
	Entry 			ent = {0};
	BerElement 		ber = *e->lm_ber;
	Attribute 		*attr, **attrp;
	struct berval 		*bv, bdn;
	const char 		*text;
	dncookie		dc;

	if ( ber_scanf( &ber, "{m{", &bdn ) == LBER_ERROR ) {
		return LDAP_DECODING_ERROR;
	}

	/*
	 * Rewrite the dn of the result, if needed
	 */
	dc.rwmap = &li->targets[ target ]->rwmap;
	dc.conn = op->o_conn;
	dc.rs = rs;
	dc.ctx = "searchResult";

	rs->sr_err = ldap_back_dn_massage( &dc, &bdn, &ent.e_name );
	if ( rs->sr_err != LDAP_SUCCESS) {
		return rs->sr_err;
	}

	/*
	 * Note: this may fail if the target host(s) schema differs
	 * from the one known to the meta, and a DN with unknown
	 * attributes is returned.
	 * 
	 * FIXME: should we log anything, or delegate to dnNormalize?
	 */
	if ( dnNormalize( 0, NULL, NULL, &ent.e_name, &ent.e_nname,
		op->o_tmpmemctx ) != LDAP_SUCCESS )
	{
		return LDAP_INVALID_DN_SYNTAX;
	}

	/*
	 * cache dn
	 */
	if ( li->cache.ttl != META_DNCACHE_DISABLED ) {
		( void )meta_dncache_update_entry( &li->cache,
				&ent.e_nname, target );
	}

	attrp = &ent.e_attrs;

	dc.ctx = "searchAttrDN";
	while ( ber_scanf( &ber, "{m", &a ) != LBER_ERROR ) {
		int		last = 0;

		ldap_back_map( &li->targets[ target ]->rwmap.rwm_at, 
				&a, &mapped, BACKLDAP_REMAP );
		if ( mapped.bv_val == NULL || mapped.bv_val[0] == '\0' ) {
			continue;
		}
		attr = ( Attribute * )ch_malloc( sizeof( Attribute ) );
		if ( attr == NULL ) {
			continue;
		}
		attr->a_flags = 0;
		attr->a_next = 0;
		attr->a_desc = NULL;
		if ( slap_bv2ad( &mapped, &attr->a_desc, &text )
				!= LDAP_SUCCESS) {
			if ( slap_bv2undef_ad( &mapped, &attr->a_desc, &text ) 
					!= LDAP_SUCCESS) {
				Debug( LDAP_DEBUG_ANY,
						"slap_bv2undef_ad(%s): "
						"%s\n%s", mapped.bv_val, text, "" );
				ch_free( attr );
				continue;
			}
		}

		/* no subschemaSubentry */
		if ( attr->a_desc == slap_schema.si_ad_subschemaSubentry ) {

			/* 
			 * We eat target's subschemaSubentry because
			 * a search for this value is likely not
			 * to resolve to the appropriate backend;
			 * later, the local subschemaSubentry is
			 * added.
			 */
			( void )ber_scanf( &ber, "x" /* [W] */ );

			ch_free(attr);
			continue;
		}

		if ( ber_scanf( &ber, "[W]", &attr->a_vals ) == LBER_ERROR 
				|| attr->a_vals == NULL ) {
			attr->a_vals = &slap_dummy_bv;

		} else if ( attr->a_desc == slap_schema.si_ad_objectClass
				|| attr->a_desc == slap_schema.si_ad_structuralObjectClass ) {

			for ( last = 0; attr->a_vals[ last ].bv_val; ++last );

			for ( bv = attr->a_vals; bv->bv_val; bv++ ) {
				ldap_back_map( &li->targets[ target ]->rwmap.rwm_oc,
						bv, &mapped, BACKLDAP_REMAP );
				if ( mapped.bv_val == NULL || mapped.bv_val[0] == '\0') {
					free( bv->bv_val );
					bv->bv_val = NULL;
					if ( --last < 0 ) {
						break;
					}
					*bv = attr->a_vals[ last ];
					attr->a_vals[ last ].bv_val = NULL;
					bv--;

				} else if ( mapped.bv_val != bv->bv_val ) {
					free( bv->bv_val );
					ber_dupbv( bv, &mapped );
				}
			}
		/*
		 * It is necessary to try to rewrite attributes with
		 * dn syntax because they might be used in ACLs as
		 * members of groups; since ACLs are applied to the
		 * rewritten stuff, no dn-based subecj clause could
		 * be used at the ldap backend side (see
		 * http://www.OpenLDAP.org/faq/data/cache/452.html)
		 * The problem can be overcome by moving the dn-based
		 * ACLs to the target directory server, and letting
		 * everything pass thru the ldap backend.
		 */
		} else if ( attr->a_desc->ad_type->sat_syntax ==
				slap_schema.si_syn_distinguishedName ) {
			ldap_dnattr_result_rewrite( &dc, attr->a_vals );

		} else if ( attr->a_desc == slap_schema.si_ad_ref ) {
			ldap_back_referral_result_rewrite( &dc, attr->a_vals );
		}

		if ( last && attr->a_desc->ad_type->sat_equality &&
			attr->a_desc->ad_type->sat_equality->smr_normalize ) {
			int i;

			attr->a_nvals = ch_malloc((last + 1)*sizeof(struct berval));
			for ( i = 0; i<last; i++ ) {
				attr->a_desc->ad_type->sat_equality->smr_normalize(
					SLAP_MR_VALUE_OF_ATTRIBUTE_SYNTAX,
					attr->a_desc->ad_type->sat_syntax,
					attr->a_desc->ad_type->sat_equality,
					&attr->a_vals[i], &attr->a_nvals[i],
					NULL );
			}
			attr->a_nvals[i].bv_val = NULL;
			attr->a_nvals[i].bv_len = 0;
		} else {
			attr->a_nvals = attr->a_vals;
		}

		*attrp = attr;
		attrp = &attr->a_next;
	}
	rs->sr_entry = &ent;
	rs->sr_attrs = op->ors_attrs;
	rs->sr_flags = 0;
	send_search_entry( op, rs );
	rs->sr_entry = NULL;
	rs->sr_attrs = NULL;
	while ( ent.e_attrs ) {
		attr = ent.e_attrs;
		ent.e_attrs = attr->a_next;
		if ( attr->a_vals != &slap_dummy_bv ) {
			ber_bvarray_free( attr->a_vals );
		}
		free( attr );
	}
	
	if ( ent.e_dn && ent.e_dn != bdn.bv_val ) {
		free( ent.e_dn );
	}
	if ( ent.e_ndn ) {
		free( ent.e_ndn );
	}

	return LDAP_SUCCESS;
}