conn.c

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

	 * require all connections ...
	 */
	if ( op_type == META_OP_REQUIRE_ALL ) {

		/* Looks like we didn't get a bind. Open a new session... */
		if ( mc == NULL ) {
			assert( new_conn == 0 );
			mc = metaconn_alloc( op );
			mc->mc_conn = mc_curr.mc_conn;
			ber_dupbv( &mc->mc_local_ndn, &mc_curr.mc_local_ndn );
			new_conn = 1;
			if ( sendok & LDAP_BACK_BINDING ) {
				LDAP_BACK_CONN_BINDING_SET( mc );
			}
			if ( LDAP_BACK_CONN_ISPRIV( &mc_curr ) ) {
				LDAP_BACK_CONN_ISPRIV_SET( mc );

			} else if ( LDAP_BACK_CONN_ISANON( &mc_curr ) ) {
				LDAP_BACK_CONN_ISANON_SET( mc );
			}

		} else if ( 0 ) {
			/* TODO: if any of the connections is binding,
			 * release mc and create a new one */
		}

		for ( i = 0; i < mi->mi_ntargets; i++ ) {
			/*
			 * The target is activated; if needed, it is
			 * also init'd
			 */
			candidates[ i ].sr_err = meta_back_init_one_conn( op,
				rs, mc, i, LDAP_BACK_CONN_ISPRIV( &mc_curr ),
				LDAP_BACK_DONTSEND, !new_conn );
			if ( candidates[ i ].sr_err == LDAP_SUCCESS ) {
				META_CANDIDATE_SET( &candidates[ i ] );
				ncandidates++;
	
			} else {
				
				/*
				 * FIXME: in case one target cannot
				 * be init'd, should the other ones
				 * be tried?
				 */
				META_CANDIDATE_RESET( &candidates[ i ] );
				err = candidates[ i ].sr_err;
				continue;
			}
		}

		if ( ncandidates == 0 ) {
			if ( new_conn ) {
				mc->mc_refcnt = 0;
				meta_back_conn_free( mc );

			} else {
				meta_back_release_conn( mi, mc );
			}

			rs->sr_err = LDAP_NO_SUCH_OBJECT;
			rs->sr_text = "Unable to select valid candidates";

			if ( sendok & LDAP_BACK_SENDERR ) {
				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
					rs->sr_matched = op->o_bd->be_suffix[ 0 ].bv_val;
				}
				send_ldap_result( op, rs );
				rs->sr_matched = NULL;
			}

			return NULL;
		}

		goto done;
	}
	
	/*
	 * looks in cache, if any
	 */
	if ( mi->mi_cache.ttl != META_DNCACHE_DISABLED ) {
		cached = i = meta_dncache_get_target( &mi->mi_cache, &op->o_req_ndn );
	}

	if ( op_type == META_OP_REQUIRE_SINGLE ) {
		metatarget_t		*mt = NULL;
		metasingleconn_t	*msc = NULL;

		int			j;

		for ( j = 0; j < mi->mi_ntargets; j++ ) {
			META_CANDIDATE_RESET( &candidates[ j ] );
		}

		/*
		 * tries to get a unique candidate
		 * (takes care of default target)
		 */
		if ( i == META_TARGET_NONE ) {
			i = meta_back_get_candidate( op, rs, &ndn );

			if ( rs->sr_err == LDAP_NO_SUCH_OBJECT && dn_type == META_DNTYPE_PARENT ) {
				i = meta_back_get_candidate( op, rs, &pndn );
			}
	
			if ( i < 0 || rs->sr_err != LDAP_SUCCESS ) {
				if ( mc != NULL ) {
					meta_back_release_conn( mi, mc );
				}

				if ( sendok & LDAP_BACK_SENDERR ) {
					if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
						rs->sr_matched = op->o_bd->be_suffix[ 0 ].bv_val;
					}
					send_ldap_result( op, rs );
					rs->sr_matched = NULL;
				}
			
				return NULL;
			}
		}

		if ( dn_type == META_DNTYPE_NEWPARENT && meta_back_get_candidate( op, rs, op->orr_nnewSup ) != i )
		{
			if ( mc != NULL ) {
				meta_back_release_conn( mi, mc );
			}

			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
			rs->sr_text = "Cross-target rename not supported";
			if ( sendok & LDAP_BACK_SENDERR ) {
				send_ldap_result( op, rs );
			}

			return NULL;
		}

		Debug( LDAP_DEBUG_TRACE,
	"==>meta_back_getconn: got target=%d for ndn=\"%s\" from cache\n",
				i, op->o_req_ndn.bv_val, 0 );

		if ( mc == NULL ) {
			/* Retries searching for a metaconn in the avl tree
			 * the reason is that the connection might have been
			 * created by meta_back_get_candidate() */
			if ( !( sendok & LDAP_BACK_BINDING ) ) {
retry_lock2:;
				ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
				mc = (metaconn_t *)avl_find( mi->mi_conninfo.lai_tree, 
					(caddr_t)&mc_curr, meta_back_conndn_cmp );
				if ( mc != NULL ) {
					/* catch taint errors */
					assert( !LDAP_BACK_CONN_TAINTED( mc ) );

					/* Don't reuse connections while they're still binding */
					if ( META_BACK_CONN_CREATING( &mc->mc_conns[ i ] )
						|| LDAP_BACK_CONN_BINDING( &mc->mc_conns[ i ] ) )
					{
						if ( !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
							ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
							ldap_pvt_thread_yield();
							goto retry_lock2;
						}

						mc = NULL;

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

			/* Looks like we didn't get a bind. Open a new session... */
			if ( mc == NULL ) {
				assert( new_conn == 0 );
				mc = metaconn_alloc( op );
				mc->mc_conn = mc_curr.mc_conn;
				ber_dupbv( &mc->mc_local_ndn, &mc_curr.mc_local_ndn );
				new_conn = 1;
				if ( sendok & LDAP_BACK_BINDING ) {
					LDAP_BACK_CONN_BINDING_SET( mc );
				}
				if ( LDAP_BACK_CONN_ISPRIV( &mc_curr ) ) {
					LDAP_BACK_CONN_ISPRIV_SET( mc );

				} else if ( LDAP_BACK_CONN_ISANON( &mc_curr ) ) {
					LDAP_BACK_CONN_ISANON_SET( mc );
				}
			}
		}

		/*
		 * Clear all other candidates
		 */
		( void )meta_clear_unused_candidates( op, i );

		mt = mi->mi_targets[ i ];
		msc = &mc->mc_conns[ i ];

		/*
		 * The target is activated; if needed, it is
		 * also init'd. In case of error, meta_back_init_one_conn
		 * sends the appropriate result.
		 */
		err = meta_back_init_one_conn( op, rs, mc, i,
			LDAP_BACK_CONN_ISPRIV( &mc_curr ), sendok, !new_conn );
		if ( err != LDAP_SUCCESS ) {
			/*
			 * FIXME: in case one target cannot
			 * be init'd, should the other ones
			 * be tried?
			 */
			META_CANDIDATE_RESET( &candidates[ i ] );
 			if ( new_conn ) {
				mc->mc_refcnt = 0;
				meta_back_conn_free( mc );

			} else {
				meta_back_release_conn( mi, mc );
			}
			return NULL;
		}

		candidates[ i ].sr_err = LDAP_SUCCESS;
		META_CANDIDATE_SET( &candidates[ i ] );
		ncandidates++;

		if ( candidate ) {
			*candidate = i;
		}

	/*
	 * if no unique candidate ...
	 */
	} else {

		/* Looks like we didn't get a bind. Open a new session... */
		if ( mc == NULL ) {
			assert( new_conn == 0 );
			mc = metaconn_alloc( op );
			mc->mc_conn = mc_curr.mc_conn;
			ber_dupbv( &mc->mc_local_ndn, &mc_curr.mc_local_ndn );
			new_conn = 1;
			if ( LDAP_BACK_CONN_ISPRIV( &mc_curr ) ) {
				LDAP_BACK_CONN_ISPRIV_SET( mc );

			} else if ( LDAP_BACK_CONN_ISANON( &mc_curr ) ) {
				LDAP_BACK_CONN_ISANON_SET( mc );
			}
		}

		for ( i = 0; i < mi->mi_ntargets; i++ ) {
			metatarget_t		*mt = mi->mi_targets[ i ];

			META_CANDIDATE_RESET( &candidates[ i ] );

			if ( i == cached 
				|| meta_back_is_candidate( mt, &op->o_req_ndn,
					LDAP_SCOPE_SUBTREE ) )
			{

				/*
				 * The target is activated; if needed, it is
				 * also init'd
				 */
				int lerr = meta_back_init_one_conn( op, rs, mc, i,
					LDAP_BACK_CONN_ISPRIV( &mc_curr ),
					LDAP_BACK_DONTSEND, !new_conn );
				candidates[ i ].sr_err = lerr;
				if ( lerr == LDAP_SUCCESS ) {
					META_CANDIDATE_SET( &candidates[ i ] );
					ncandidates++;

					Debug( LDAP_DEBUG_TRACE, "%s: meta_back_getconn[%d]\n",
						op->o_log_prefix, i, 0 );

				} else if ( lerr == LDAP_UNAVAILABLE && !META_BACK_ONERR_STOP( mi ) ) {
					META_CANDIDATE_SET( &candidates[ i ] );

					Debug( LDAP_DEBUG_TRACE, "%s: meta_back_getconn[%d] %s\n",
						op->o_log_prefix, i,
						mt->mt_isquarantined != LDAP_BACK_FQ_NO ? "quarantined" : "unavailable" );

				} else {
				
					/*
					 * FIXME: in case one target cannot
					 * be init'd, should the other ones
					 * be tried?
					 */
					if ( new_conn ) {
						( void )meta_clear_one_candidate( op, mc, i );
					}
					/* leave the target candidate, but record the error for later use */
					err = lerr;

					if ( lerr == LDAP_UNAVAILABLE && mt->mt_isquarantined != LDAP_BACK_FQ_NO ) {
						Debug( LDAP_DEBUG_TRACE, "%s: meta_back_getconn[%d] quarantined err=%d\n",
							op->o_log_prefix, i, lerr );

					} else {
						Debug( LDAP_DEBUG_ANY, "%s: meta_back_getconn[%d] failed err=%d\n",
							op->o_log_prefix, i, lerr );
					}

					if ( META_BACK_ONERR_STOP( mi ) ) {
						if ( sendok & LDAP_BACK_SENDERR ) {
							send_ldap_result( op, rs );
						}
						if ( new_conn ) {
							mc->mc_refcnt = 0;
							meta_back_conn_free( mc );

						} else {
							meta_back_release_conn( mi, mc );
						}

						return NULL;
					}

					continue;
				}

			} else {
				if ( new_conn ) {
					( void )meta_clear_one_candidate( op, mc, i );
				}
			}
		}

		if ( ncandidates == 0 ) {
			if ( new_conn ) {
				mc->mc_refcnt = 0;
				meta_back_conn_free( mc );

			} else {
				meta_back_release_conn( mi, mc );
			}

			if ( rs->sr_err == LDAP_SUCCESS ) {
				rs->sr_err = LDAP_NO_SUCH_OBJECT;
				rs->sr_text = "Unable to select valid candidates";
			}

			if ( sendok & LDAP_BACK_SENDERR ) {
				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
					rs->sr_matched = op->o_bd->be_suffix[ 0 ].bv_val;
				}
				send_ldap_result( op, rs );
				rs->sr_matched = NULL;
			}

			return NULL;
		}
	}

done:;
	/* clear out meta_back_init_one_conn non-fatal errors */
	rs->sr_err = LDAP_SUCCESS;
	rs->sr_text = NULL;

	/* touch the timestamp */
	if ( mi->mi_idle_timeout != 0 ) {
		mc->mc_time = op->o_time;
	}

	if ( new_conn ) {
		if ( mi->mi_conn_ttl ) {
			mc->mc_create_time = op->o_time;
		}

		/*
		 * Inserts the newly created metaconn in the avl tree
		 */
		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
#if META_BACK_PRINT_CONNTREE > 0
		meta_back_print_conntree( mi, ">>> meta_back_getconn" );
#endif /* META_BACK_PRINT_CONNTREE */

		if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
			if ( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num < mi->mi_conn_priv_max ) {
				LDAP_TAILQ_INSERT_TAIL( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv, mc, mc_q );
				mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num++;
				LDAP_BACK_CONN_CACHED_SET( mc );

			} else {
				LDAP_BACK_CONN_TAINTED_SET( mc );
			}
			rs->sr_err = 0;

		} else {
			err = avl_insert( &mi->mi_conninfo.lai_tree, ( caddr_t )mc,
			       	meta_back_conndn_cmp, meta_back_conndn_dup );
			LDAP_BACK_CONN_CACHED_SET( mc );
		}

#if META_BACK_PRINT_CONNTREE > 0
		meta_back_print_conntree( mi, ">>> meta_back_getconn" );
#endif /* META_BACK_PRINT_CONNTREE */
		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );

		if ( !LDAP_BACK_PCONN_ISPRIV( mc ) ) {
			/*
			 * Err could be -1 in case a duplicate metaconn is inserted
			 */
			switch ( err ) {
			case 0:
				break;

			case -1:
				LDAP_BACK_CONN_CACHED_CLEAR( mc );
				/* duplicate: free and try to get the newly created one */
				if ( !( sendok & LDAP_BACK_BINDING ) && !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
					mc->mc_refcnt = 0;	
					meta_back_conn_free( mc );
	
					new_conn = 0;
					goto retry_lock;
				}

				LDAP_BACK_CONN_TAINTED_SET( mc );
				break;

			default:
				LDAP_BACK_CONN_CACHED_CLEAR( mc );
				Debug( LDAP_DEBUG_ANY,
					"%s meta_back_getconn: candidates=%d conn=%ld insert failed\n",
					op->o_log_prefix, ncandidates,
					LDAP_BACK_PCONN_ID( mc ) );
	
				mc->mc_refcnt = 0;	
				meta_back_conn_free( mc );

				rs->sr_err = LDAP_OTHER;
				rs->sr_text = "Proxy bind collision";
				if ( sendok & LDAP_BACK_SENDERR ) {
					send_ldap_result( op, rs );
				}
				return NULL;
			}
		}

		Debug( LDAP_DEBUG_TRACE,
			"%s meta_back_getconn: candidates=%d conn=%ld inserted\n",
			op->o_log_prefix, ncandidates,
			LDAP_BACK_PCONN_ID( mc ) );

	} else {
		Debug( LDAP_DEBUG_TRACE,
			"%s meta_back_getconn: candidates=%d conn=%ld fetched\n",
			op->o_log_prefix, ncandidates,
			LDAP_BACK_PCONN_ID( mc ) );
	}

	return mc;
}

void
meta_back_release_conn_lock(
       	metainfo_t		*mi,
	metaconn_t		*mc,
	int			dolock )
{
	assert( mc != NULL );

	if ( dolock ) {
		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
	}
	assert( mc->mc_refcnt > 0 );
	mc->mc_refcnt--;
	/* NOTE: the connection is removed if either it is tainted
	 * or if it is shared and no one else is using it.  This needs
	 * to occur because for intrinsic reasons cached connections
	 * that are not privileged would live forever and pollute
	 * the connection space (and eat up resources).  Maybe this
	 * should be configurable... */
	if ( LDAP_BACK_CONN_TAINTED( mc ) ) {
#if META_BACK_PRINT_CONNTREE > 0
		meta_back_print_conntree( mi, ">>> meta_back_release_conn" );
#endif /* META_BACK_PRINT_CONNTREE */

		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 {
			metaconn_t	*tmpmc;

			tmpmc = avl_delete( &mi->mi_conninfo.lai_tree,
				( caddr_t )mc, meta_back_conndnmc_cmp );

			/* Overparanoid, but useful... */
			assert( tmpmc == NULL || tmpmc == mc );
		}

		LDAP_BACK_CONN_CACHED_CLEAR( mc );

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

		if ( mc->mc_refcnt == 0 ) {
			meta_back_conn_free( mc );
			mc = NULL;
		}
	}

	if ( mc != NULL && LDAP_BACK_CONN_BINDING( mc ) ) {
		LDAP_BACK_CONN_BINDING_CLEAR( mc );
	}

	if ( dolock ) {
		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
	}
}

void
meta_back_quarantine(
	Operation	*op,
	SlapReply	*rs,
	int		candidate )
{
	metainfo_t		*mi = (metainfo_t *)op->o_bd->be_private;
	metatarget_t		*mt = mi->mi_targets[ candidate ];

	slap_retry_info_t	*ri = &mt->mt_quarantine;

	ldap_pvt_thread_mutex_lock( &mt->mt_quarantine_mutex );

	if ( rs->sr_err == LDAP_UNAVAILABLE ) {
		time_t	new_last = slap_get_time();

		switch ( mt->mt_isquarantined ) {
		case LDAP_BACK_FQ_NO:
			if ( ri->ri_last == new_last ) {
				goto done;
			}

			Debug( LDAP_DEBUG_ANY,
				"%s meta_back_quarantine[%d]: enter.\n",
				op->o_log_prefix, candidate, 0 );

			ri->ri_idx = 0;
			ri->ri_count = 0;
			break;

		case LDAP_BACK_FQ_RETRYING:
			if ( StatslogTest( LDAP_DEBUG_ANY ) ) {
				char	buf[ SLAP_TEXT_BUFLEN ];

				snprintf( buf, sizeof( buf ),
					"meta_back_quarantine[%d]: block #%d try #%d failed",
					candidate, ri->ri_idx, ri->ri_count );
				Debug( LDAP_DEBUG_ANY, "%s %s.\n",
					op->o_log_prefix, buf, 0 );
			}

			++ri->ri_count;
			if ( ri->ri_num[ ri->ri_idx ] != SLAP_RETRYNUM_FOREVER
				&& ri->ri_count == ri->ri_num[ ri->ri_idx ] )
			{
				ri->ri_count = 0;
				++ri->ri_idx;
			}
			break;

		default:
			break;
		}

		mt->mt_isquarantined = LDAP_BACK_FQ_YES;
		ri->ri_last = new_last;

	} else if ( mt->mt_isquarantined == LDAP_BACK_FQ_RETRYING ) {
		Debug( LDAP_DEBUG_ANY,
			"%s meta_back_quarantine[%d]: exit.\n",
			op->o_log_prefix, candidate, 0 );

		if ( mi->mi_quarantine_f ) {
			(void)mi->mi_quarantine_f( mi, candidate,
				mi->mi_quarantine_p );
		}

		ri->ri_count = 0;
		ri->ri_idx = 0;
		mt->mt_isquarantined = LDAP_BACK_FQ_NO;
	}

done:;
	ldap_pvt_thread_mutex_unlock( &mt->mt_quarantine_mutex );
}