conn.c

来自「ldap服务器源码」· C语言 代码 · 共 1,810 行 · 第 1/3 页

				ber_dupbv( &msc->msc_bound_ndn, &op->o_conn->c_dn );
			}

			assert( !BER_BVISNULL( &msc->msc_bound_ndn ) );

		} else {
			ber_dupbv( &msc->msc_bound_ndn, (struct berval *)&slap_empty_bv );
		}
	}

	assert( !BER_BVISNULL( &msc->msc_bound_ndn ) );

error_return:;
	if ( dolock ) {
		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
	}
	META_BACK_CONN_CREATING_CLEAR( msc );
	if ( rs->sr_err == LDAP_SUCCESS ) {
		/*
		 * Sets a cookie for the rewrite session
		 */
		( void )rewrite_session_init( mt->mt_rwmap.rwm_rw, op->o_conn );
		META_BACK_CONN_INITED_SET( msc );
	}
	if ( dolock ) {
		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
	}

	if ( rs->sr_err != LDAP_SUCCESS ) {
		rs->sr_err = slap_map_api2result( rs );
		if ( sendok & LDAP_BACK_SENDERR ) {
			send_ldap_result( op, rs );
		}
	}

	return rs->sr_err;
}

/*
 * meta_back_retry
 * 
 * Retries one connection
 */
int
meta_back_retry(
	Operation		*op,
	SlapReply		*rs,
	metaconn_t		**mcp,
	int			candidate,
	ldap_back_send_t	sendok )
{
	metainfo_t		*mi = ( metainfo_t * )op->o_bd->be_private;
	metatarget_t		*mt = mi->mi_targets[ candidate ];
	metaconn_t		*mc = *mcp;
	metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
	int			rc = LDAP_UNAVAILABLE,
				binding,
				quarantine = 1;

	ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );

	assert( !META_BACK_CONN_CREATING( msc ) );
	binding = LDAP_BACK_CONN_BINDING( msc );
	LDAP_BACK_CONN_BINDING_CLEAR( msc );

	assert( mc->mc_refcnt > 0 );
	if ( mc->mc_refcnt == 1 ) {
		if ( StatslogTest( LDAP_DEBUG_ANY ) ) {
			char	buf[ SLAP_TEXT_BUFLEN ];

			/* this lock is required; however,
			 * it's invoked only when logging is on */
			ldap_pvt_thread_mutex_lock( &mt->mt_uri_mutex );
			snprintf( buf, sizeof( buf ),
				"retrying URI=\"%s\" DN=\"%s\"",
				mt->mt_uri,
				BER_BVISNULL( &msc->msc_bound_ndn ) ?
					"" : msc->msc_bound_ndn.bv_val );
			ldap_pvt_thread_mutex_unlock( &mt->mt_uri_mutex );

			Debug( LDAP_DEBUG_ANY,
				"%s meta_back_retry[%d]: %s.\n",
				op->o_log_prefix, candidate, buf );
		}

		meta_clear_one_candidate( op, mc, candidate );
		LDAP_BACK_CONN_ISBOUND_CLEAR( msc );

		( void )rewrite_session_delete( mt->mt_rwmap.rwm_rw, op->o_conn );

		/* mc here must be the regular mc, reset and ready for init */
		rc = meta_back_init_one_conn( op, rs, mc, candidate,
			LDAP_BACK_CONN_ISPRIV( mc ), sendok, 0 );

		/* restore the "binding" flag, in case */
		if ( binding ) {
			LDAP_BACK_CONN_BINDING_SET( msc );
		}

		if ( rc == LDAP_SUCCESS ) {
			quarantine = 0;
			rc = meta_back_single_dobind( op, rs, mcp, candidate,
				sendok, mt->mt_nretries, 0 );

			Debug( LDAP_DEBUG_ANY,
				"%s meta_back_retry[%d]: "
				"meta_back_single_dobind=%d\n",
				op->o_log_prefix, candidate, rc );
			if ( rc == LDAP_SUCCESS ) {
				if ( !BER_BVISNULL( &msc->msc_bound_ndn ) &&
					!BER_BVISEMPTY( &msc->msc_bound_ndn ) )
				{
					LDAP_BACK_CONN_ISBOUND_SET( msc );

				} else {
					LDAP_BACK_CONN_ISANON_SET( msc );
				}

				/* when bound, dispose of the "binding" flag */
				if ( binding ) {
					LDAP_BACK_CONN_BINDING_CLEAR( msc );
				}
			}
        	}

		/* don't send twice */
		sendok &= ~LDAP_BACK_SENDERR;
	}

	if ( rc != LDAP_SUCCESS ) {
		SlapReply		*candidates = meta_back_candidates_get( op );

		candidates[ candidate ].sr_err = rc;

		if ( *mcp != NULL ) {
			if ( mc->mc_refcnt == 1 ) {
				if ( binding ) {
					LDAP_BACK_CONN_BINDING_CLEAR( msc );
				}
				(void)meta_clear_one_candidate( op, mc, candidate );
			}

			LDAP_BACK_CONN_TAINTED_SET( mc );
			/* only release if mandatory; otherwise
			 * let the caller do what's best before
			 * releasing */
			if ( META_BACK_ONERR_STOP( mi ) ) {
				meta_back_release_conn_lock( mi, mc, 0 );
				*mcp = NULL;

			} else {
#if META_BACK_PRINT_CONNTREE > 0
				meta_back_print_conntree( mi, ">>> meta_back_retry" );
#endif /* META_BACK_PRINT_CONNTREE */

				/* FIXME: could be done better, reworking meta_back_release_conn_lock() */
				if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
					if ( mc->mc_q.tqe_prev != NULL ) {
						assert( LDAP_BACK_CONN_CACHED( mc ) );
						assert( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num > 0 );
						LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
							mc, mc_q );
						mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num--;
						LDAP_TAILQ_ENTRY_INIT( mc, mc_q );

					} else {
						assert( !LDAP_BACK_CONN_CACHED( mc ) );
					}

				} else {
					/* FIXME: check if in tree, for consistency? */
					(void)avl_delete( &mi->mi_conninfo.lai_tree,
						( caddr_t )mc, meta_back_conndnmc_cmp );
				}
				LDAP_BACK_CONN_CACHED_CLEAR( mc );

#if META_BACK_PRINT_CONNTREE > 0
				meta_back_print_conntree( mi, "<<< meta_back_retry" );
#endif /* META_BACK_PRINT_CONNTREE */
			}
		}

		if ( sendok & LDAP_BACK_SENDERR ) {
			rs->sr_err = rc;
			rs->sr_text = "Unable to retry";
			send_ldap_result( op, rs );
		}
	}

	if ( quarantine && META_BACK_TGT_QUARANTINE( mt ) ) {
		meta_back_quarantine( op, rs, candidate );
	}

	ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );

	return rc == LDAP_SUCCESS ? 1 : 0;
}

/*
 * callback for unique candidate selection
 */
static int
meta_back_conn_cb( Operation *op, SlapReply *rs )
{
	assert( op->o_tag == LDAP_REQ_SEARCH );

	switch ( rs->sr_type ) {
	case REP_SEARCH:
		((long *)op->o_callback->sc_private)[0] = (long)op->o_private;
		break;

	case REP_SEARCHREF:
	case REP_RESULT:
		break;

	default:
		return rs->sr_err;
	}

	return 0;
}


static int
meta_back_get_candidate(
	Operation	*op,
	SlapReply	*rs,
	struct berval	*ndn )
{
	metainfo_t	*mi = ( metainfo_t * )op->o_bd->be_private;
	long		candidate;

	/*
	 * tries to get a unique candidate
	 * (takes care of default target)
	 */
	candidate = meta_back_select_unique_candidate( mi, ndn );

	/*
	 * if any is found, inits the connection
	 */
	if ( candidate == META_TARGET_NONE ) {
		rs->sr_err = LDAP_NO_SUCH_OBJECT;
		rs->sr_text = "No suitable candidate target found";

	} else if ( candidate == META_TARGET_MULTIPLE ) {
		Filter		f = { 0 };
		Operation	op2 = *op;
		SlapReply	rs2 = { 0 };
		slap_callback	cb2 = { 0 };
		int		rc;

		/* try to get a unique match for the request ndn
		 * among the multiple candidates available */
		op2.o_tag = LDAP_REQ_SEARCH;
		op2.o_req_dn = *ndn;
		op2.o_req_ndn = *ndn;
		op2.ors_scope = LDAP_SCOPE_BASE;
		op2.ors_deref = LDAP_DEREF_NEVER;
		op2.ors_attrs = slap_anlist_no_attrs;
		op2.ors_attrsonly = 0;
		op2.ors_limit = NULL;
		op2.ors_slimit = 1;
		op2.ors_tlimit = SLAP_NO_LIMIT;

		f.f_choice = LDAP_FILTER_PRESENT;
		f.f_desc = slap_schema.si_ad_objectClass;
		op2.ors_filter = &f;
		BER_BVSTR( &op2.ors_filterstr, "(objectClass=*)" );

		op2.o_callback = &cb2;
		cb2.sc_response = meta_back_conn_cb;
		cb2.sc_private = (void *)&candidate;

		rc = op->o_bd->be_search( &op2, &rs2 );

		switch ( rs2.sr_err ) {
		case LDAP_SUCCESS:
		default:
			rs->sr_err = rs2.sr_err;
			break;

		case LDAP_SIZELIMIT_EXCEEDED:
			/* if multiple candidates can serve the operation,
			 * and a default target is defined, and it is
			 * a candidate, try using it (FIXME: YMMV) */
			if ( mi->mi_defaulttarget != META_DEFAULT_TARGET_NONE
				&& meta_back_is_candidate( mi->mi_targets[ mi->mi_defaulttarget ],
						ndn, op->o_tag == LDAP_REQ_SEARCH ? op->ors_scope : LDAP_SCOPE_BASE ) )
			{
				candidate = mi->mi_defaulttarget;
				rs->sr_err = LDAP_SUCCESS;
				rs->sr_text = NULL;

			} else {
				rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
				rs->sr_text = "Unable to select unique candidate target";
			}
			break;
		}

	} else {
		rs->sr_err = LDAP_SUCCESS;
	}

	return candidate;
}

static void	*meta_back_candidates_dummy;

static void
meta_back_candidates_keyfree(
	void		*key,
	void		*data )
{
	metacandidates_t	*mc = (metacandidates_t *)data;

	ber_memfree_x( mc->mc_candidates, NULL );
	ber_memfree_x( data, NULL );
}

SlapReply *
meta_back_candidates_get( Operation *op )
{
	metainfo_t		*mi = ( metainfo_t * )op->o_bd->be_private;
	metacandidates_t	*mc;

	if ( op->o_threadctx ) {
		void		*data = NULL;

		ldap_pvt_thread_pool_getkey( op->o_threadctx,
				&meta_back_candidates_dummy, &data, NULL );
		mc = (metacandidates_t *)data;

	} else {
		mc = mi->mi_candidates;
	}

	if ( mc == NULL ) {
		mc = ch_calloc( sizeof( metacandidates_t ), 1 );
		mc->mc_ntargets = mi->mi_ntargets;
		mc->mc_candidates = ch_calloc( sizeof( SlapReply ), mc->mc_ntargets );
		if ( op->o_threadctx ) {
			void		*data = NULL;

			data = (void *)mc;
			ldap_pvt_thread_pool_setkey( op->o_threadctx,
					&meta_back_candidates_dummy, data,
					meta_back_candidates_keyfree );

		} else {
			mi->mi_candidates = mc;
		}

	} else if ( mc->mc_ntargets < mi->mi_ntargets ) {
		/* NOTE: in the future, may want to allow back-config
		 * to add/remove targets from back-meta... */
		mc->mc_candidates = ch_realloc( mc->mc_candidates,
				sizeof( SlapReply ) * mi->mi_ntargets );
		memset( &mc->mc_candidates[ mc->mc_ntargets ], 0,
			sizeof( SlapReply ) * ( mi->mi_ntargets - mc->mc_ntargets ) );
		mc->mc_ntargets = mi->mi_ntargets;
	}

	return mc->mc_candidates;
}

/*
 * meta_back_getconn
 * 
 * Prepares the connection structure
 * 
 * RATIONALE:
 *
 * - determine what DN is being requested:
 *
 *	op	requires candidate	checks
 *
 *	add	unique			parent of o_req_ndn
 *	bind	unique^*[/all]		o_req_ndn [no check]
 *	compare	unique^+		o_req_ndn
 *	delete	unique			o_req_ndn
 *	modify	unique			o_req_ndn
 *	search	any			o_req_ndn
 *	modrdn	unique[, unique]	o_req_ndn[, orr_nnewSup]
 *
 * - for ops that require the candidate to be unique, in case of multiple
 *   occurrences an internal search with sizeLimit=1 is performed
 *   if a unique candidate can actually be determined.  If none is found,
 *   the operation aborts; if multiple are found, the default target
 *   is used if defined and candidate; otherwise the operation aborts.
 *
 * *^note: actually, the bind operation is handled much like a search;
 *   i.e. the bind is broadcast to all candidate targets.
 *
 * +^note: actually, the compare operation is handled much like a search;
 *   i.e. the compare is broadcast to all candidate targets, while checking
 *   that exactly none (noSuchObject) or one (TRUE/FALSE/UNDEFINED) is
 *   returned.
 */
metaconn_t *
meta_back_getconn(
       	Operation 		*op,
	SlapReply		*rs,
	int 			*candidate,
	ldap_back_send_t	sendok )
{
	metainfo_t	*mi = ( metainfo_t * )op->o_bd->be_private;
	metaconn_t	*mc = NULL,
			mc_curr = { 0 };
	int		cached = META_TARGET_NONE,
			i = META_TARGET_NONE,
			err = LDAP_SUCCESS,
			new_conn = 0,
			ncandidates = 0;


	meta_op_type	op_type = META_OP_REQUIRE_SINGLE;
	enum		{
		META_DNTYPE_ENTRY,
		META_DNTYPE_PARENT,
		META_DNTYPE_NEWPARENT
	}		dn_type = META_DNTYPE_ENTRY;
	struct berval	ndn = op->o_req_ndn,
			pndn;

	SlapReply	*candidates = meta_back_candidates_get( op );

	/* Internal searches are privileged and shared. So is root. */
	if ( ( !BER_BVISEMPTY( &op->o_ndn ) && META_BACK_PROXYAUTHZ_ALWAYS( mi ) )
		|| ( BER_BVISEMPTY( &op->o_ndn ) && META_BACK_PROXYAUTHZ_ANON( mi ) )
		|| op->o_do_not_cache || be_isroot( op ) )
	{
		LDAP_BACK_CONN_ISPRIV_SET( &mc_curr );
		mc_curr.mc_local_ndn = op->o_bd->be_rootndn;
		LDAP_BACK_PCONN_ROOTDN_SET( &mc_curr, op );

	} else if ( BER_BVISEMPTY( &op->o_ndn ) && META_BACK_PROXYAUTHZ_NOANON( mi ) )
	{
		LDAP_BACK_CONN_ISANON_SET( &mc_curr );
		BER_BVSTR( &mc_curr.mc_local_ndn, "" );
		LDAP_BACK_PCONN_ANON_SET( &mc_curr, op );

	} else {
		mc_curr.mc_local_ndn = op->o_ndn;

		/* Explicit binds must not be shared */
		if ( !BER_BVISEMPTY( &op->o_ndn )
			|| op->o_tag == LDAP_REQ_BIND
			|| SLAP_IS_AUTHZ_BACKEND( op ) )
		{
			mc_curr.mc_conn = op->o_conn;
	
		} else {
			LDAP_BACK_CONN_ISANON_SET( &mc_curr );
			LDAP_BACK_PCONN_ANON_SET( &mc_curr, op );
		}
	}

	/* Explicit Bind requests always get their own conn */
	if ( sendok & LDAP_BACK_BINDING ) {
		mc_curr.mc_conn = op->o_conn;

	} else {
		/* Searches for a metaconn in the avl tree */
retry_lock:;
		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
		if ( LDAP_BACK_PCONN_ISPRIV( &mc_curr ) ) {
			/* lookup a conn that's not binding */
			LDAP_TAILQ_FOREACH( mc,
				&mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( &mc_curr ) ].mic_priv,
				mc_q )
			{
				if ( !LDAP_BACK_CONN_BINDING( mc ) && mc->mc_refcnt == 0 ) {
					break;
				}
			}

			if ( mc != NULL ) {
				if ( mc != LDAP_TAILQ_LAST( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
					metaconn_t, mc_q ) )
				{
					LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
						mc, mc_q );
					LDAP_TAILQ_ENTRY_INIT( mc, mc_q );
					LDAP_TAILQ_INSERT_TAIL( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
						mc, mc_q );
				}

			} else if ( !LDAP_BACK_USE_TEMPORARIES( mi )
				&& mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( &mc_curr ) ].mic_num == mi->mi_conn_priv_max )
			{
				mc = LDAP_TAILQ_FIRST( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( &mc_curr ) ].mic_priv );
			}
			

		} else {
			mc = (metaconn_t *)avl_find( mi->mi_conninfo.lai_tree, 
				(caddr_t)&mc_curr, meta_back_conndn_cmp );
		}

		if ( mc ) {
			/* catch taint errors */
			assert( !LDAP_BACK_CONN_TAINTED( mc ) );

			/* Don't reuse connections while they're still binding
			 * NOTE: only makes sense for binds */
			if ( LDAP_BACK_CONN_BINDING( mc ) ) {
				if ( !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
					ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );

					ldap_pvt_thread_yield();
					goto retry_lock;
				}

				/* release conn, and create a temporary */
				mc = NULL;

			} else {
				if ( ( mi->mi_conn_ttl != 0 && op->o_time > mc->mc_create_time + mi->mi_conn_ttl )
					|| ( mi->mi_idle_timeout != 0 && op->o_time > mc->mc_time + mi->mi_idle_timeout ) )
				{
#if META_BACK_PRINT_CONNTREE > 0
					meta_back_print_conntree( mi,
						">>> meta_back_getconn(expired)" );
#endif /* META_BACK_PRINT_CONNTREE */

					/* don't let anyone else use this expired connection */
					if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
						if ( mc->mc_q.tqe_prev != NULL ) {
							assert( LDAP_BACK_CONN_CACHED( mc ) );
							assert( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num > 0 );
							LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
								mc, mc_q );
							mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num--;
							LDAP_TAILQ_ENTRY_INIT( mc, mc_q );

						} else {
							assert( !LDAP_BACK_CONN_CACHED( mc ) );
						}

					} else {
						(void)avl_delete( &mi->mi_conninfo.lai_tree,
							(caddr_t)mc, meta_back_conndnmc_cmp );
					}

#if META_BACK_PRINT_CONNTREE > 0
					meta_back_print_conntree( mi,
						"<<< meta_back_getconn(expired)" );
#endif /* META_BACK_PRINT_CONNTREE */
					LDAP_BACK_CONN_TAINTED_SET( mc );
					LDAP_BACK_CONN_CACHED_CLEAR( mc );

					Debug( LDAP_DEBUG_TRACE, "%s meta_back_getconn: mc=%p conn=%ld expired (tainted).\n",
						op->o_log_prefix, (void *)mc, LDAP_BACK_PCONN_ID( mc ) );
				}

				mc->mc_refcnt++;
			}
		}
		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
	}

	switch ( op->o_tag ) {
	case LDAP_REQ_ADD:
		/* if we go to selection, the entry must not exist,
		 * and we must be able to resolve the parent */
		dn_type = META_DNTYPE_PARENT;
		dnParent( &ndn, &pndn );
		break;

	case LDAP_REQ_MODRDN:
		/* if nnewSuperior is not NULL, it must resolve
		 * to the same candidate as the req_ndn */
		if ( op->orr_nnewSup ) {
			dn_type = META_DNTYPE_NEWPARENT;
		}
		break;

	case LDAP_REQ_BIND:
		/* if bound as rootdn, the backend must bind to all targets
		 * with the administrative identity */
		if ( op->orb_method == LDAP_AUTH_SIMPLE && be_isroot_pw( op ) ) {
			op_type = META_OP_REQUIRE_ALL;
		}
		break;

	case LDAP_REQ_COMPARE:
	case LDAP_REQ_DELETE:
	case LDAP_REQ_MODIFY:
		/* just a unique candidate */
		break;

	case LDAP_REQ_SEARCH:
		/* allow multiple candidates for the searchBase */
		op_type = META_OP_ALLOW_MULTIPLE;
		break;

	default:
		/* right now, just break (exop?) */
		break;
	}

	/*