/*	$NetBSD: search.c,v 1.2 2021/08/14 16:15:02 christos Exp $	*/

/* OpenLDAP WiredTiger backend */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 2002-2021 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>.
 */
/* ACKNOWLEDGEMENTS:
 * This work was developed by HAMANO Tsukasa <hamano@osstech.co.jp>
 * based on back-bdb for inclusion in OpenLDAP Software.
 * WiredTiger is a product of MongoDB Inc.
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: search.c,v 1.2 2021/08/14 16:15:02 christos Exp $");

#include "portable.h"

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

#include "back-wt.h"
#include "idl.h"

static int search_aliases(
	Operation *op,
	SlapReply *rs,
	Entry *e,
	WT_SESSION *session,
	ID *ids,
	ID *scopes,
	ID *stack )
{
	/* TODO: search_aliases does not implement yet. */
	WT_IDL_ZERO( ids );
	return 0;
}

static int base_candidate(
	BackendDB *be,
	Entry *e,
	ID *ids )
{
	Debug(LDAP_DEBUG_ARGS,
		  LDAP_XSTRING(base_candidate)
		  ": base: \"%s\" (0x%08lx)\n",
		  e->e_nname.bv_val, (long) e->e_id );

	ids[0] = 1;
	ids[1] = e->e_id;
	return 0;
}

/* Look for "objectClass Present" in this filter.
 * Also count depth of filter tree while we're at it.
 */
static int oc_filter(
	Filter *f,
	int cur,
	int *max )
{
	int rc = 0;

	assert( f != NULL );

	if( cur > *max ) *max = cur;

	switch( f->f_choice ) {
	case LDAP_FILTER_PRESENT:
		if (f->f_desc == slap_schema.si_ad_objectClass) {
			rc = 1;
		}
		break;

	case LDAP_FILTER_AND:
	case LDAP_FILTER_OR:
		cur++;
		for ( f=f->f_and; f; f=f->f_next ) {
			(void) oc_filter(f, cur, max);
		}
		break;

	default:
		break;
	}
	return rc;
}

static void search_stack_free( void *key, void *data )
{
	ber_memfree_x(data, NULL);
}

static void *search_stack( Operation *op )
{
	struct wt_info *wi = (struct wt_info *) op->o_bd->be_private;
	void *ret = NULL;

	if ( op->o_threadctx ) {
		ldap_pvt_thread_pool_getkey( op->o_threadctx, (void *)search_stack,
									 &ret, NULL );
	} else {
		ret = wi->wi_search_stack;
	}

	if ( !ret ) {
		ret = ch_malloc( wi->wi_search_stack_depth * WT_IDL_UM_SIZE
						 * sizeof( ID ) );
		if ( op->o_threadctx ) {
			ldap_pvt_thread_pool_setkey( op->o_threadctx, (void *)search_stack,
										 ret, search_stack_free, NULL, NULL );
		} else {
			wi->wi_search_stack = ret;
		}
	}
	return ret;
}

static int search_candidates(
	Operation *op,
	SlapReply *rs,
	Entry *e,
	wt_ctx *wc,
	ID  *ids,
	ID  *scopes )
{
    struct wt_info *wi = (struct wt_info *) op->o_bd->be_private;
	int rc, depth = 1;
	Filter f, rf, xf, nf;
	ID *stack;
	AttributeAssertion aa_ref = ATTRIBUTEASSERTION_INIT;
	Filter sf;
	AttributeAssertion aa_subentry = ATTRIBUTEASSERTION_INIT;

	Debug(LDAP_DEBUG_TRACE,
		  LDAP_XSTRING(wt_search_candidates)
		  ": base=\"%s\" (0x%08lx) scope=%d\n",
		  e->e_nname.bv_val, (long) e->e_id, op->oq_search.rs_scope );

	xf.f_or = op->oq_search.rs_filter;
	xf.f_choice = LDAP_FILTER_OR;
	xf.f_next = NULL;

	/* If the user's filter uses objectClass=*,
     * these clauses are redundant.
     */
	if (!oc_filter(op->oq_search.rs_filter, 1, &depth)
		&& !get_subentries_visibility(op)) {
		if( !get_manageDSAit(op) && !get_domainScope(op) ) {
			/* match referral objects */
			struct berval bv_ref = BER_BVC( "referral" );
			rf.f_choice = LDAP_FILTER_EQUALITY;
			rf.f_ava = &aa_ref;
			rf.f_av_desc = slap_schema.si_ad_objectClass;
			rf.f_av_value = bv_ref;
			rf.f_next = xf.f_or;
			xf.f_or = &rf;
			depth++;
		}
	}

	f.f_next = NULL;
	f.f_choice = LDAP_FILTER_AND;
	f.f_and = &nf;
	/* Dummy; we compute scope separately now */
	nf.f_choice = SLAPD_FILTER_COMPUTED;
	nf.f_result = LDAP_SUCCESS;
	nf.f_next = ( xf.f_or == op->oq_search.rs_filter )
		? op->oq_search.rs_filter : &xf ;
	/* Filter depth increased again, adding dummy clause */
	depth++;

	if( get_subentries_visibility( op ) ) {
		struct berval bv_subentry = BER_BVC( "subentry" );
		sf.f_choice = LDAP_FILTER_EQUALITY;
		sf.f_ava = &aa_subentry;
		sf.f_av_desc = slap_schema.si_ad_objectClass;
		sf.f_av_value = bv_subentry;
		sf.f_next = nf.f_next;
		nf.f_next = &sf;
	}

	/* Allocate IDL stack, plus 1 more for former tmp */
	if ( depth+1 > wi->wi_search_stack_depth ) {
		stack = ch_malloc( (depth + 1) * WT_IDL_UM_SIZE * sizeof( ID ) );
	} else {
		stack = search_stack( op );
	}

    if( op->ors_deref & LDAP_DEREF_SEARCHING ) {
		rc = search_aliases( op, rs, e, wc->session, ids, scopes, stack );
		if ( WT_IDL_IS_ZERO( ids ) && rc == LDAP_SUCCESS )
			rc = wt_dn2idl( op, wc->session, &e->e_nname, e, ids, stack );
	} else {
		rc = wt_dn2idl(op, wc->session, &e->e_nname, e, ids, stack );
	}

	if ( rc == LDAP_SUCCESS ) {
		rc = wt_filter_candidates( op, wc, &f, ids,
								   stack, stack+WT_IDL_UM_SIZE );
	}

	if ( depth+1 > wi->wi_search_stack_depth ) {
		ch_free( stack );
	}

    if( rc ) {
		Debug(LDAP_DEBUG_TRACE,
			  LDAP_XSTRING(wt_search_candidates)
			  ": failed (rc=%d)\n",
			  rc );

	} else {
		Debug(LDAP_DEBUG_TRACE,
			  LDAP_XSTRING(wt_search_candidates)
			  ": id=%ld first=%ld last=%ld\n",
			  (long) ids[0],
			  (long) WT_IDL_FIRST(ids),
			  (long) WT_IDL_LAST(ids));
	}
	return 0;
}

static int
parse_paged_cookie( Operation *op, SlapReply *rs )
{
	int     rc = LDAP_SUCCESS;
	PagedResultsState *ps = op->o_pagedresults_state;

	/* this function must be invoked only if the pagedResults
     * control has been detected, parsed and partially checked
     * by the frontend */
	assert( get_pagedresults( op ) > SLAP_CONTROL_IGNORED );

	/* cookie decoding/checks deferred to backend... */
	if ( ps->ps_cookieval.bv_len ) {
		PagedResultsCookie reqcookie;
		if( ps->ps_cookieval.bv_len != sizeof( reqcookie ) ) {
			/* bad cookie */
			rs->sr_text = "paged results cookie is invalid";
			rc = LDAP_PROTOCOL_ERROR;
			goto done;
		}

		AC_MEMCPY( &reqcookie, ps->ps_cookieval.bv_val, sizeof( reqcookie ));

		if ( reqcookie > ps->ps_cookie ) {
			/* bad cookie */
			rs->sr_text = "paged results cookie is invalid";
			rc = LDAP_PROTOCOL_ERROR;
			goto done;

		} else if ( reqcookie < ps->ps_cookie ) {
			rs->sr_text = "paged results cookie is invalid or old";
			rc = LDAP_UNWILLING_TO_PERFORM;
			goto done;
		}

	} else {
		/* we're going to use ps_cookie */
		op->o_conn->c_pagedresults_state.ps_cookie = 0;
	}

done:;

	return rc;
}

static void
send_paged_response(
	Operation   *op,
	SlapReply   *rs,
	ID      *lastid,
	int     tentries )
{
	LDAPControl *ctrls[2];
	BerElementBuffer berbuf;
	BerElement  *ber = (BerElement *)&berbuf;
	PagedResultsCookie respcookie;
	struct berval cookie;

	Debug(LDAP_DEBUG_ARGS,
		  LDAP_XSTRING(send_paged_response)
		  ": lastid=0x%08lx nentries=%d\n",
		  lastid ? *lastid : 0, rs->sr_nentries );

	ctrls[1] = NULL;

	ber_init2( ber, NULL, LBER_USE_DER );

	if ( lastid ) {
		respcookie = ( PagedResultsCookie )(*lastid);
		cookie.bv_len = sizeof( respcookie );
		cookie.bv_val = (char *)&respcookie;

	} else {
		respcookie = ( PagedResultsCookie )0;
		BER_BVSTR( &cookie, "" );
	}

	op->o_conn->c_pagedresults_state.ps_cookie = respcookie;
	op->o_conn->c_pagedresults_state.ps_count =
		((PagedResultsState *)op->o_pagedresults_state)->ps_count +
		rs->sr_nentries;

	/* return size of 0 -- no estimate */
	ber_printf( ber, "{iO}", 0, &cookie );

	ctrls[0] = op->o_tmpalloc( sizeof(LDAPControl), op->o_tmpmemctx );
	if ( ber_flatten2( ber, &ctrls[0]->ldctl_value, 0 ) == -1 ) {
		goto done;
	}

	ctrls[0]->ldctl_oid = LDAP_CONTROL_PAGEDRESULTS;
	ctrls[0]->ldctl_iscritical = 0;

	slap_add_ctrls( op, rs, ctrls );
	rs->sr_err = LDAP_SUCCESS;
	send_ldap_result( op, rs );

done:
	(void) ber_free_buf( ber );
}

int
wt_search( Operation *op, SlapReply *rs )
{
    struct wt_info *wi = (struct wt_info *) op->o_bd->be_private;
	ID id, cursor;
	ID lastid = NOID;
	AttributeName *attrs;
	OpExtra *oex;
	int manageDSAit;
	wt_ctx *wc;
	int rc;
	Entry *e = NULL;
	Entry *base = NULL;
	slap_mask_t mask;
	time_t stoptime;

	ID candidates[WT_IDL_UM_SIZE];
	ID iscopes[WT_IDL_DB_SIZE];
	ID scopes[WT_IDL_DB_SIZE];
	int tentries = 0;
	unsigned nentries = 0;

	Debug( LDAP_DEBUG_ARGS, "==> " LDAP_XSTRING(wt_search) ": %s\n",
		   op->o_req_dn.bv_val );
    attrs = op->oq_search.rs_attrs;

	manageDSAit = get_manageDSAit( op );

	wc = wt_ctx_get(op, wi);
	if( !wc ){
        Debug( LDAP_DEBUG_ANY,
			   LDAP_XSTRING(wt_search)
			   ": wt_ctx_get failed: %d\n",
			   rc );
		send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
        return rc;
	}

	/* get entry */
	rc = wt_dn2entry(op->o_bd, wc, &op->o_req_ndn, &e);
	switch( rc ) {
	case 0:
		break;
	case WT_NOTFOUND:
		Debug( LDAP_DEBUG_ARGS,
			   "<== " LDAP_XSTRING(wt_search)
			   ": no such object %s\n",
			   op->o_req_dn.bv_val );
		rs->sr_err = LDAP_REFERRAL;
		rs->sr_flags = REP_MATCHED_MUSTBEFREED | REP_REF_MUSTBEFREED;
		send_ldap_result( op, rs );
		goto done;
	default:
		/* TODO: error handling */
		Debug( LDAP_DEBUG_ANY,
			   LDAP_XSTRING(wt_delete)
			   ": error at wt_dn2entry() rc=%d\n",
			   rc );
		send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
		goto done;
	}

	if ( op->ors_deref & LDAP_DEREF_FINDING ) {
		/* not implement yet */
	}

	if ( e == NULL ) {
		// TODO
	}

	/* NOTE: __NEW__ "search" access is required
     * on searchBase object */
	if ( ! access_allowed_mask( op, e, slap_schema.si_ad_entry,
								NULL, ACL_SEARCH, NULL, &mask ) )
	{
		if ( !ACL_GRANT( mask, ACL_DISCLOSE ) ) {
			rs->sr_err = LDAP_NO_SUCH_OBJECT;
		} else {
			rs->sr_err = LDAP_INSUFFICIENT_ACCESS;
		}

		send_ldap_result( op, rs );
		goto done;
	}

	if ( !manageDSAit && is_entry_referral( e ) ) {
		/* entry is a referral */
		/* TODO: */
	}

	if ( get_assert( op ) &&
		 ( test_filter( op, e, get_assertion( op )) != LDAP_COMPARE_TRUE ))
	{
		rs->sr_err = LDAP_ASSERTION_FAILED;
		send_ldap_result( op, rs );
		goto done;
	}

	/* compute it anyway; root does not use it */
	stoptime = op->o_time + op->ors_tlimit;

	base = e;

	e = NULL;

	/* select candidates */
	if ( op->oq_search.rs_scope == LDAP_SCOPE_BASE ) {
		rs->sr_err = base_candidate( op->o_bd, base, candidates );
	}else{
		WT_IDL_ZERO( candidates );
		WT_IDL_ZERO( scopes );
		rc = search_candidates( op, rs, base,
								wc, candidates, scopes );
		switch(rc){
		case 0:
		case WT_NOTFOUND:
			break;
		default:
			Debug( LDAP_DEBUG_ANY,
				   LDAP_XSTRING(wt_search) ": error search_candidates\n" );
			send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
			goto done;
		}
	}

	/* start cursor at beginning of candidates.
     */
	cursor = 0;

	if ( candidates[0] == 0 ) {
		Debug( LDAP_DEBUG_TRACE,
			   LDAP_XSTRING(wt_search) ": no candidates\n" );
		goto nochange;
	}

	if ( op->ors_limit &&
		 op->ors_limit->lms_s_unchecked != -1 &&
		 WT_IDL_N(candidates) > (unsigned) op->ors_limit->lms_s_unchecked )
	{
		rs->sr_err = LDAP_ADMINLIMIT_EXCEEDED;
		send_ldap_result( op, rs );
		rs->sr_err = LDAP_SUCCESS;
		goto done;
	}

	if ( op->ors_limit == NULL  /* isroot == TRUE */ ||
		 !op->ors_limit->lms_s_pr_hide )
	{
		tentries = WT_IDL_N(candidates);
	}

	if ( get_pagedresults( op ) > SLAP_CONTROL_IGNORED ) {
		/* TODO: pageresult */
		PagedResultsState *ps = op->o_pagedresults_state;
		/* deferred cookie parsing */
		rs->sr_err = parse_paged_cookie( op, rs );
		if ( rs->sr_err != LDAP_SUCCESS ) {
			send_ldap_result( op, rs );
			goto done;
		}

		cursor = (ID) ps->ps_cookie;
		if ( cursor && ps->ps_size == 0 ) {
			rs->sr_err = LDAP_SUCCESS;
			rs->sr_text = "search abandoned by pagedResult size=0";
			send_ldap_result( op, rs );
			goto done;
		}
		id = wt_idl_first( candidates, &cursor );
		if ( id == NOID ) {
			Debug( LDAP_DEBUG_TRACE,
				   LDAP_XSTRING(wt_search)
				   ": no paged results candidates\n" );
			send_paged_response( op, rs, &lastid, 0 );

			rs->sr_err = LDAP_OTHER;
			goto done;
		}
		nentries = ps->ps_count;
		if ( id == (ID)ps->ps_cookie )
			id = wt_idl_next( candidates, &cursor );
		goto loop_begin;
	}

	for ( id = wt_idl_first( candidates, &cursor );
		  id != NOID ; id = wt_idl_next( candidates, &cursor ) )
	{
		int scopeok;

loop_begin:

		/* check for abandon */
		if ( op->o_abandon ) {
			rs->sr_err = SLAPD_ABANDON;
			send_ldap_result( op, rs );
			goto done;
		}

		/* mostly needed by internal searches,
         * e.g. related to syncrepl, for whom
         * abandon does not get set... */
		if ( slapd_shutdown ) {
			rs->sr_err = LDAP_UNAVAILABLE;
			send_ldap_disconnect( op, rs );
			goto done;
		}

		/* check time limit */
		if ( op->ors_tlimit != SLAP_NO_LIMIT
			 && slap_get_time() > stoptime )
		{
			rs->sr_err = LDAP_TIMELIMIT_EXCEEDED;
			rs->sr_ref = rs->sr_v2ref;
			send_ldap_result( op, rs );
			rs->sr_err = LDAP_SUCCESS;
			goto done;
		}

		nentries++;

	fetch_entry_retry:

		rc = wt_id2entry(op->o_bd, wc->session, id, &e);
		/* TODO: error handling */
		if ( e == NULL ) {
			/* TODO: */
			goto loop_continue;
		}
		if ( is_entry_subentry( e ) ) {
            if( op->oq_search.rs_scope != LDAP_SCOPE_BASE ) {
				if(!get_subentries_visibility( op )) {
					/* only subentries are visible */
					goto loop_continue;
				}

			} else if ( get_subentries( op ) &&
						!get_subentries_visibility( op ))
			{
				/* only subentries are visible */
				goto loop_continue;
			}

		} else if ( get_subentries_visibility( op )) {
			/* only subentries are visible */
			goto loop_continue;
		}

		scopeok = 0;
		switch( op->ors_scope ) {
		case LDAP_SCOPE_BASE:
			/* This is always true, yes? */
			if ( id == base->e_id ) scopeok = 1;
			break;
		case LDAP_SCOPE_ONELEVEL:
			scopeok = 1;
			break;
		case LDAP_SCOPE_SUBTREE:
			scopeok = 1;
			break;
		}

		/* aliases were already dereferenced in candidate list */
		if ( op->ors_deref & LDAP_DEREF_SEARCHING ) {
			/* but if the search base is an alias, and we didn't
			 * deref it when finding, return it.
			 */
			if ( is_entry_alias(e) &&
				 ((op->ors_deref & LDAP_DEREF_FINDING) ||
				  !bvmatch(&e->e_nname, &op->o_req_ndn)))
			{
				goto loop_continue;
			}
			/* TODO: alias handling */
		}

		/* Not in scope, ignore it */
		if ( !scopeok )
		{
			Debug( LDAP_DEBUG_TRACE,
				   LDAP_XSTRING(wt_search)
				   ": %ld scope not okay\n",
				   (long) id );
			goto loop_continue;
		}

		/*
         * if it's a referral, add it to the list of referrals. only do
         * this for non-base searches, and don't check the filter
         * explicitly here since it's only a candidate anyway.
         */
		if ( !manageDSAit && op->oq_search.rs_scope != LDAP_SCOPE_BASE
			 && is_entry_referral( e ) )
		{
			/* TODO: referral */
		}

		if ( !manageDSAit && is_entry_glue( e )) {
			goto loop_continue;
		}

		/* if it matches the filter and scope, send it */
		rs->sr_err = test_filter( op, e, op->oq_search.rs_filter );
		if ( rs->sr_err == LDAP_COMPARE_TRUE ) {
			/* check size limit */
			if ( get_pagedresults(op) > SLAP_CONTROL_IGNORED ) {
				/* TODO: */
			}

			if (e) {
				/* safe default */
				rs->sr_attrs = op->oq_search.rs_attrs;
				rs->sr_operational_attrs = NULL;
				rs->sr_ctrls = NULL;
				rs->sr_entry = e;
				RS_ASSERT( e->e_private != NULL );
				rs->sr_flags = REP_ENTRY_MUSTRELEASE;
				rs->sr_err = LDAP_SUCCESS;
				rs->sr_err = send_search_entry( op, rs );
				rs->sr_attrs = NULL;
				rs->sr_entry = NULL;
				e = NULL;
			}
			switch ( rs->sr_err ) {
			case LDAP_SUCCESS:  /* entry sent ok */
				break;
			default:
				/* TODO: error handling */
				break;
			}
		} else {
			Debug( LDAP_DEBUG_TRACE,
				   LDAP_XSTRING(wt_search)
				   ": %ld does not match filter\n",
				   (long) id );
		}

	loop_continue:
		if( e ) {
			wt_entry_return( e );
			e = NULL;
		}
	}

nochange:
    rs->sr_ctrls = NULL;
	rs->sr_ref = rs->sr_v2ref;
	rs->sr_err = (rs->sr_v2ref == NULL) ? LDAP_SUCCESS : LDAP_REFERRAL;
	rs->sr_rspoid = NULL;
	if ( get_pagedresults(op) > SLAP_CONTROL_IGNORED ) {
		/* not implement yet */
		/* send_paged_response( op, rs, NULL, 0 ); */
	} else {
		send_ldap_result( op, rs );
	}

	rs->sr_err = LDAP_SUCCESS;

done:

	if( base ) {
		wt_entry_return( base );
	}

	if( e ) {
		wt_entry_return( e );
	}

    return rs->sr_err;
}

/*
 * Local variables:
 * indent-tabs-mode: t
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 */