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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:35:32 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:35:32 +0000
commit5ea77a75dd2d2158401331879f3c8f47940a732c (patch)
treed89dc06e9f4850a900f161e25f84e922c4f86cc8 /servers/lloadd/backend.c
parentInitial commit. (diff)
downloadopenldap-5ea77a75dd2d2158401331879f3c8f47940a732c.tar.xz
openldap-5ea77a75dd2d2158401331879f3c8f47940a732c.zip
Adding upstream version 2.5.13+dfsg.upstream/2.5.13+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'servers/lloadd/backend.c')
-rw-r--r--servers/lloadd/backend.c736
1 files changed, 736 insertions, 0 deletions
diff --git a/servers/lloadd/backend.c b/servers/lloadd/backend.c
new file mode 100644
index 0000000..ab0e932
--- /dev/null
+++ b/servers/lloadd/backend.c
@@ -0,0 +1,736 @@
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1998-2022 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>.
+ */
+
+#include "portable.h"
+
+#include <ac/socket.h>
+#include <ac/errno.h>
+#include <ac/string.h>
+#include <ac/time.h>
+#include <ac/unistd.h>
+
+#include <event2/event.h>
+#include <event2/dns.h>
+
+#include "lutil.h"
+#include "lload.h"
+
+static void
+upstream_connect_cb( evutil_socket_t s, short what, void *arg )
+{
+ LloadPendingConnection *conn = arg;
+ LloadBackend *b = conn->backend;
+ int error = 0, rc = -1;
+ epoch_t epoch;
+
+ checked_lock( &b->b_mutex );
+ Debug( LDAP_DEBUG_CONNS, "upstream_connect_cb: "
+ "fd=%d connection callback for backend uri='%s'\n",
+ s, b->b_uri.bv_val );
+
+ if ( s != conn->fd ) {
+ /* backend_reset has been here first */
+ goto preempted;
+ }
+
+ epoch = epoch_join();
+
+ if ( what == EV_WRITE ) {
+ socklen_t optlen = sizeof(error);
+
+ if ( getsockopt( conn->fd, SOL_SOCKET, SO_ERROR, (void *)&error,
+ &optlen ) < 0 ) {
+ goto done;
+ }
+ if ( error == EINTR || error == EINPROGRESS || error == EWOULDBLOCK ) {
+ checked_unlock( &b->b_mutex );
+ epoch_leave( epoch );
+ return;
+ } else if ( error ) {
+ goto done;
+ } else if ( upstream_init( s, conn->backend ) == NULL ) {
+ goto done;
+ }
+ rc = LDAP_SUCCESS;
+ }
+
+done:
+ epoch_leave( epoch );
+
+ LDAP_LIST_REMOVE( conn, next );
+ if ( rc ) {
+ evutil_closesocket( conn->fd );
+ b->b_opening--;
+ b->b_failed++;
+ if ( what & EV_TIMEOUT ) {
+ Debug( LDAP_DEBUG_ANY, "upstream_connect_cb: "
+ "fd=%d connection timed out\n",
+ s );
+ } else {
+ char ebuf[128];
+ Debug( LDAP_DEBUG_ANY, "upstream_connect_cb: "
+ "fd=%d connection set up failed%s%s\n",
+ s, error ? ": " : "",
+ error ? sock_errstr( error, ebuf, sizeof(ebuf) ) : "" );
+ }
+ backend_retry( b );
+ }
+preempted:
+ checked_unlock( &b->b_mutex );
+
+ event_free( conn->event );
+ ch_free( conn );
+}
+
+static void
+upstream_name_cb( int result, struct evutil_addrinfo *res, void *arg )
+{
+ LloadBackend *b = arg;
+ ber_socket_t s = AC_SOCKET_INVALID;
+ epoch_t epoch;
+ int rc;
+
+ if ( result == EVUTIL_EAI_CANCEL ) {
+ Debug( LDAP_DEBUG_ANY, "upstream_name_cb: "
+ "cancelled\n" );
+ return;
+ }
+
+ checked_lock( &b->b_mutex );
+ /* We were already running when backend_reset tried to cancel us, but were
+ * already stuck waiting for the mutex, nothing to do and b_opening has
+ * been decremented as well */
+ if ( b->b_dns_req == NULL ) {
+ checked_unlock( &b->b_mutex );
+ return;
+ }
+ b->b_dns_req = NULL;
+
+ epoch = epoch_join();
+ if ( result || !res ) {
+ Debug( LDAP_DEBUG_ANY, "upstream_name_cb: "
+ "name resolution failed for backend '%s': %s\n",
+ b->b_uri.bv_val, evutil_gai_strerror( result ) );
+ goto fail;
+ }
+
+ /* TODO: if we get failures, try the other addrinfos */
+ if ( (s = socket( res->ai_family, SOCK_STREAM, 0 )) ==
+ AC_SOCKET_INVALID ) {
+ goto fail;
+ }
+
+ if ( ber_pvt_socket_set_nonblock( s, 1 ) ) {
+ goto fail;
+ }
+
+#if defined(SO_KEEPALIVE) || defined(TCP_NODELAY)
+ if ( b->b_proto == LDAP_PROTO_TCP ) {
+ int dummy = 1;
+#ifdef SO_KEEPALIVE
+ if ( setsockopt( s, SOL_SOCKET, SO_KEEPALIVE, (char *)&dummy,
+ sizeof(dummy) ) == AC_SOCKET_ERROR ) {
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "setsockopt(%d, SO_KEEPALIVE) failed (ignored).\n",
+ s );
+ }
+ if ( bindconf.sb_keepalive.sk_idle > 0 ) {
+#ifdef TCP_KEEPIDLE
+ if ( setsockopt( s, IPPROTO_TCP, TCP_KEEPIDLE,
+ (void *)&bindconf.sb_keepalive.sk_idle,
+ sizeof(bindconf.sb_keepalive.sk_idle) ) ==
+ AC_SOCKET_ERROR ) {
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "setsockopt(%d, TCP_KEEPIDLE) failed (ignored).\n",
+ s );
+ }
+#else
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "sockopt TCP_KEEPIDLE not supported on this system.\n" );
+#endif /* TCP_KEEPIDLE */
+ }
+ if ( bindconf.sb_keepalive.sk_probes > 0 ) {
+#ifdef TCP_KEEPCNT
+ if ( setsockopt( s, IPPROTO_TCP, TCP_KEEPCNT,
+ (void *)&bindconf.sb_keepalive.sk_probes,
+ sizeof(bindconf.sb_keepalive.sk_probes) ) ==
+ AC_SOCKET_ERROR ) {
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "setsockopt(%d, TCP_KEEPCNT) failed (ignored).\n",
+ s );
+ }
+#else
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "sockopt TCP_KEEPCNT not supported on this system.\n" );
+#endif /* TCP_KEEPCNT */
+ }
+ if ( bindconf.sb_keepalive.sk_interval > 0 ) {
+#ifdef TCP_KEEPINTVL
+ if ( setsockopt( s, IPPROTO_TCP, TCP_KEEPINTVL,
+ (void *)&bindconf.sb_keepalive.sk_interval,
+ sizeof(bindconf.sb_keepalive.sk_interval) ) ==
+ AC_SOCKET_ERROR ) {
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "setsockopt(%d, TCP_KEEPINTVL) failed (ignored).\n",
+ s );
+ }
+#else
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "sockopt TCP_KEEPINTVL not supported on this system.\n" );
+#endif /* TCP_KEEPINTVL */
+ }
+#endif /* SO_KEEPALIVE */
+ if ( bindconf.sb_tcp_user_timeout > 0 ) {
+#ifdef TCP_USER_TIMEOUT
+ if ( setsockopt( s, IPPROTO_TCP, TCP_USER_TIMEOUT,
+ (void *)&bindconf.sb_tcp_user_timeout,
+ sizeof(bindconf.sb_tcp_user_timeout) ) ==
+ AC_SOCKET_ERROR ) {
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "setsockopt(%d, TCP_USER_TIMEOUT) failed (ignored).\n",
+ s );
+ }
+#else
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "sockopt TCP_USER_TIMEOUT not supported on this "
+ "system.\n" );
+#endif /* TCP_USER_TIMEOUT */
+ }
+#ifdef TCP_NODELAY
+ if ( setsockopt( s, IPPROTO_TCP, TCP_NODELAY, (char *)&dummy,
+ sizeof(dummy) ) == AC_SOCKET_ERROR ) {
+ Debug( LDAP_DEBUG_TRACE, "upstream_name_cb: "
+ "setsockopt(%d, TCP_NODELAY) failed (ignored).\n",
+ s );
+ }
+#endif /* TCP_NODELAY */
+ }
+#endif /* SO_KEEPALIVE || TCP_NODELAY */
+
+ if ( res->ai_family == PF_INET ) {
+ struct sockaddr_in *ai = (struct sockaddr_in *)res->ai_addr;
+ ai->sin_port = htons( b->b_port );
+ rc = connect( s, (struct sockaddr *)ai, res->ai_addrlen );
+ } else {
+ struct sockaddr_in6 *ai = (struct sockaddr_in6 *)res->ai_addr;
+ ai->sin6_port = htons( b->b_port );
+ rc = connect( s, (struct sockaddr *)ai, res->ai_addrlen );
+ }
+ /* Asynchronous connect */
+ if ( rc ) {
+ LloadPendingConnection *conn;
+
+ if ( errno != EINPROGRESS && errno != EWOULDBLOCK ) {
+ Debug( LDAP_DEBUG_ANY, "upstream_name_cb: "
+ "failed to connect to server '%s'\n",
+ b->b_uri.bv_val );
+ evutil_closesocket( s );
+ goto fail;
+ }
+
+ conn = ch_calloc( 1, sizeof(LloadPendingConnection) );
+ LDAP_LIST_ENTRY_INIT( conn, next );
+ conn->backend = b;
+ conn->fd = s;
+
+ conn->event = event_new( lload_get_base( s ), s, EV_WRITE|EV_PERSIST,
+ upstream_connect_cb, conn );
+ if ( !conn->event ) {
+ Debug( LDAP_DEBUG_ANY, "upstream_name_cb: "
+ "failed to acquire an event to finish upstream "
+ "connection setup.\n" );
+ ch_free( conn );
+ evutil_closesocket( s );
+ goto fail;
+ }
+
+ event_add( conn->event, lload_timeout_net );
+ LDAP_LIST_INSERT_HEAD( &b->b_connecting, conn, next );
+ Debug( LDAP_DEBUG_CONNS, "upstream_name_cb: "
+ "connection to backend uri=%s in progress\n",
+ b->b_uri.bv_val );
+ } else if ( upstream_init( s, b ) == NULL ) {
+ goto fail;
+ }
+
+ checked_unlock( &b->b_mutex );
+ evutil_freeaddrinfo( res );
+ epoch_leave( epoch );
+ return;
+
+fail:
+ if ( s != AC_SOCKET_INVALID ) {
+ evutil_closesocket( s );
+ }
+ b->b_opening--;
+ b->b_failed++;
+ backend_retry( b );
+ checked_unlock( &b->b_mutex );
+ if ( res ) {
+ evutil_freeaddrinfo( res );
+ }
+ epoch_leave( epoch );
+}
+
+LloadConnection *
+backend_select( LloadOperation *op, int *res )
+{
+ LloadBackend *b, *first, *next;
+
+ checked_lock( &backend_mutex );
+ first = b = current_backend;
+ checked_unlock( &backend_mutex );
+
+ *res = LDAP_UNAVAILABLE;
+
+ if ( !first ) {
+ return NULL;
+ }
+
+ /* TODO: Two runs, one with trylock, then one actually locked if we don't
+ * find anything? */
+ do {
+ lload_c_head *head;
+ LloadConnection *c;
+
+ checked_lock( &b->b_mutex );
+ next = LDAP_CIRCLEQ_LOOP_NEXT( &backend, b, b_next );
+
+ if ( b->b_max_pending && b->b_n_ops_executing >= b->b_max_pending ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_select: "
+ "backend %s too busy\n",
+ b->b_uri.bv_val );
+ checked_unlock( &b->b_mutex );
+ b = next;
+ *res = LDAP_BUSY;
+ continue;
+ }
+
+ if ( op->o_tag == LDAP_REQ_BIND
+#ifdef LDAP_API_FEATURE_VERIFY_CREDENTIALS
+ && !(lload_features & LLOAD_FEATURE_VC)
+#endif /* LDAP_API_FEATURE_VERIFY_CREDENTIALS */
+ ) {
+ head = &b->b_bindconns;
+ } else {
+ head = &b->b_conns;
+ }
+ if ( !LDAP_CIRCLEQ_EMPTY( head ) ) {
+ *res = LDAP_BUSY;
+ }
+
+ LDAP_CIRCLEQ_FOREACH ( c, head, c_next ) {
+ checked_lock( &c->c_io_mutex );
+ CONNECTION_LOCK(c);
+ if ( c->c_state == LLOAD_C_READY && !c->c_pendingber &&
+ ( b->b_max_conn_pending == 0 ||
+ c->c_n_ops_executing < b->b_max_conn_pending ) ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_select: "
+ "selected connection connid=%lu for client "
+ "connid=%lu msgid=%d\n",
+ c->c_connid, op->o_client_connid, op->o_client_msgid );
+
+ /* c_state is DYING if we're about to be unlinked */
+ assert( IS_ALIVE( c, c_live ) );
+
+ /*
+ * Round-robin step:
+ * Rotate the queue to put this connection at the end, same for
+ * the backend.
+ */
+ LDAP_CIRCLEQ_MAKE_TAIL( head, c, c_next );
+
+ checked_lock( &backend_mutex );
+ current_backend = next;
+ checked_unlock( &backend_mutex );
+
+ b->b_n_ops_executing++;
+ if ( op->o_tag == LDAP_REQ_BIND ) {
+ b->b_counters[LLOAD_STATS_OPS_BIND].lc_ops_received++;
+ } else {
+ b->b_counters[LLOAD_STATS_OPS_OTHER].lc_ops_received++;
+ }
+ c->c_n_ops_executing++;
+ c->c_counters.lc_ops_received++;
+
+ checked_unlock( &b->b_mutex );
+ *res = LDAP_SUCCESS;
+ CONNECTION_ASSERT_LOCKED(c);
+ assert_locked( &c->c_io_mutex );
+ return c;
+ }
+ CONNECTION_UNLOCK(c);
+ checked_unlock( &c->c_io_mutex );
+ }
+ checked_unlock( &b->b_mutex );
+
+ b = next;
+ } while ( b != first );
+
+ return NULL;
+}
+
+/*
+ * Will schedule a connection attempt if there is a need for it. Need exclusive
+ * access to backend, its b_mutex is not touched here, though.
+ */
+void
+backend_retry( LloadBackend *b )
+{
+ int requested;
+
+ if ( slapd_shutdown ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_retry: "
+ "shutting down\n" );
+ return;
+ }
+ assert_locked( &b->b_mutex );
+
+ requested = b->b_numconns;
+#ifdef LDAP_API_FEATURE_VERIFY_CREDENTIALS
+ if ( !(lload_features & LLOAD_FEATURE_VC) )
+#endif /* LDAP_API_FEATURE_VERIFY_CREDENTIALS */
+ {
+ requested += b->b_numbindconns;
+ }
+
+ if ( b->b_active + b->b_bindavail + b->b_opening >= requested ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_retry: "
+ "no more connections needed for this backend\n" );
+ assert_locked( &b->b_mutex );
+ return;
+ }
+
+ if ( b->b_opening > 0 ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_retry: "
+ "retry in progress already\n" );
+ assert( b->b_opening == 1 );
+ assert_locked( &b->b_mutex );
+ return;
+ }
+
+ /* We incremented b_opening when we activated the event, so it can't be
+ * pending */
+ assert( !event_pending( b->b_retry_event, EV_TIMEOUT, NULL ) );
+ b->b_opening++;
+
+ if ( b->b_failed > 0 ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_retry: "
+ "scheduling a retry in %d ms\n",
+ b->b_retry_timeout );
+ event_add( b->b_retry_event, &b->b_retry_tv );
+ assert_locked( &b->b_mutex );
+ return;
+ }
+
+ Debug( LDAP_DEBUG_CONNS, "backend_retry: "
+ "scheduling re-connection straight away\n" );
+
+ if ( ldap_pvt_thread_pool_submit2(
+ &connection_pool, backend_connect_task, b, &b->b_cookie ) ) {
+ Debug( LDAP_DEBUG_ANY, "backend_retry: "
+ "failed to submit retry task, scheduling a retry instead\n" );
+ /* The current implementation of ldap_pvt_thread_pool_submit2 can fail
+ * and still set (an invalid) cookie */
+ b->b_cookie = NULL;
+ b->b_failed++;
+ event_add( b->b_retry_event, &b->b_retry_tv );
+ }
+ assert_locked( &b->b_mutex );
+}
+
+void
+backend_connect( evutil_socket_t s, short what, void *arg )
+{
+ struct evutil_addrinfo hints = {};
+ LloadBackend *b = arg;
+ struct evdns_getaddrinfo_request *request, *placeholder;
+ char *hostname;
+ epoch_t epoch;
+
+ checked_lock( &b->b_mutex );
+ assert( b->b_dns_req == NULL );
+
+ if ( b->b_cookie ) {
+ b->b_cookie = NULL;
+ }
+
+ if ( slapd_shutdown ) {
+ Debug( LDAP_DEBUG_CONNS, "backend_connect: "
+ "doing nothing, shutdown in progress\n" );
+ b->b_opening--;
+ checked_unlock( &b->b_mutex );
+ return;
+ }
+
+ epoch = epoch_join();
+
+ Debug( LDAP_DEBUG_CONNS, "backend_connect: "
+ "%sattempting connection to %s\n",
+ (what & EV_TIMEOUT) ? "retry timeout finished, " : "",
+ b->b_host );
+
+#ifdef LDAP_PF_LOCAL
+ if ( b->b_proto == LDAP_PROTO_IPC ) {
+ struct sockaddr_un addr;
+ ber_socket_t s = socket( PF_LOCAL, SOCK_STREAM, 0 );
+ int rc;
+
+ if ( s == AC_SOCKET_INVALID ) {
+ goto fail;
+ }
+
+ rc = ber_pvt_socket_set_nonblock( s, 1 );
+ if ( rc ) {
+ evutil_closesocket( s );
+ goto fail;
+ }
+
+ if ( strlen( b->b_host ) > ( sizeof(addr.sun_path) - 1 ) ) {
+ evutil_closesocket( s );
+ goto fail;
+ }
+ memset( &addr, '\0', sizeof(addr) );
+ addr.sun_family = AF_LOCAL;
+ strcpy( addr.sun_path, b->b_host );
+
+ rc = connect(
+ s, (struct sockaddr *)&addr, sizeof(struct sockaddr_un) );
+ /* Asynchronous connect */
+ if ( rc ) {
+ LloadPendingConnection *conn;
+
+ if ( errno != EINPROGRESS && errno != EWOULDBLOCK ) {
+ evutil_closesocket( s );
+ goto fail;
+ }
+
+ conn = ch_calloc( 1, sizeof(LloadPendingConnection) );
+ LDAP_LIST_ENTRY_INIT( conn, next );
+ conn->backend = b;
+ conn->fd = s;
+
+ conn->event = event_new( lload_get_base( s ), s,
+ EV_WRITE|EV_PERSIST, upstream_connect_cb, conn );
+ if ( !conn->event ) {
+ Debug( LDAP_DEBUG_ANY, "backend_connect: "
+ "failed to acquire an event to finish upstream "
+ "connection setup.\n" );
+ ch_free( conn );
+ evutil_closesocket( s );
+ goto fail;
+ }
+
+ event_add( conn->event, lload_timeout_net );
+ LDAP_LIST_INSERT_HEAD( &b->b_connecting, conn, next );
+ Debug( LDAP_DEBUG_CONNS, "backend_connect: "
+ "connection to backend uri=%s in progress\n",
+ b->b_uri.bv_val );
+ } else if ( upstream_init( s, b ) == NULL ) {
+ goto fail;
+ }
+
+ checked_unlock( &b->b_mutex );
+ epoch_leave( epoch );
+ return;
+ }
+#endif /* LDAP_PF_LOCAL */
+
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_flags = EVUTIL_AI_CANONNAME;
+ hints.ai_socktype = SOCK_STREAM;
+ hints.ai_protocol = IPPROTO_TCP;
+
+ hostname = b->b_host;
+
+ /*
+ * Picking any value on the stack. This is unique to our thread without
+ * having to call ldap_pvt_thread_self.
+ * We might have to revert to using ldap_pvt_thread_self eventually since
+ * this betrays where exactly our stack lies - potentially weakening some
+ * protections like ASLR.
+ */
+ placeholder = (struct evdns_getaddrinfo_request *)&request;
+ b->b_dns_req = placeholder;
+ checked_unlock( &b->b_mutex );
+
+ request = evdns_getaddrinfo(
+ dnsbase, hostname, NULL, &hints, upstream_name_cb, b );
+
+ checked_lock( &b->b_mutex );
+ assert( request || b->b_dns_req != placeholder );
+
+ /* Record the request, unless upstream_name_cb or another thread
+ * cleared it. Another thread is usually backend_reset or backend_connect
+ * if upstream_name_cb finished and scheduled another one */
+ if ( b->b_dns_req == placeholder ) {
+ b->b_dns_req = request;
+ }
+ checked_unlock( &b->b_mutex );
+ epoch_leave( epoch );
+ return;
+
+fail:
+ b->b_opening--;
+ b->b_failed++;
+ backend_retry( b );
+ checked_unlock( &b->b_mutex );
+ epoch_leave( epoch );
+}
+
+void *
+backend_connect_task( void *ctx, void *arg )
+{
+ backend_connect( -1, 0, arg );
+ return NULL;
+}
+
+/*
+ * Needs exclusive access to the backend and no other thread is allowed to call
+ * backend_retry while we're handling this.
+ *
+ * If gentle == 0, a full pause must be in effect, else we risk deadlocking on
+ * event_free().
+ */
+void
+backend_reset( LloadBackend *b, int gentle )
+{
+ assert_locked( &b->b_mutex );
+ if ( b->b_cookie ) {
+ if ( ldap_pvt_thread_pool_retract( b->b_cookie ) ) {
+ b->b_cookie = NULL;
+ b->b_opening--;
+ } else {
+ /*
+ * The task might not be cancelable because it just started
+ * executing.
+ *
+ * Shutdown should be the only time when the thread pool is
+ * in that state. Keep the cookie in to keep an eye on whether
+ * it's finished yet.
+ */
+ assert( slapd_shutdown );
+ }
+ }
+ /* Not safe to hold our mutex and call event_del/free if the event's
+ * callback is running, relinquish the mutex while we do so. */
+ if ( b->b_retry_event &&
+ event_pending( b->b_retry_event, EV_TIMEOUT, NULL ) ) {
+ assert( b->b_failed );
+ checked_unlock( &b->b_mutex );
+ event_del( b->b_retry_event );
+ checked_lock( &b->b_mutex );
+ b->b_opening--;
+ }
+ if ( b->b_dns_req ) {
+ evdns_getaddrinfo_cancel( b->b_dns_req );
+ b->b_dns_req = NULL;
+ b->b_opening--;
+ }
+ while ( !LDAP_LIST_EMPTY( &b->b_connecting ) ) {
+ LloadPendingConnection *pending = LDAP_LIST_FIRST( &b->b_connecting );
+
+ Debug( LDAP_DEBUG_CONNS, "backend_reset: "
+ "destroying socket pending connect() fd=%d\n",
+ pending->fd );
+
+ event_active( pending->event, EV_WRITE, 0 );
+ evutil_closesocket( pending->fd );
+ pending->fd = -1;
+ LDAP_LIST_REMOVE( pending, next );
+
+ if ( !gentle ) {
+ /* None of the event bases are running, we're safe to free the
+ * event right now and potentially free the backend itself */
+ event_free( pending->event );
+ ch_free( pending );
+ }
+ /* else, just let the event dispose of the resources on its own later */
+ b->b_opening--;
+ }
+ connections_walk(
+ &b->b_mutex, &b->b_preparing, lload_connection_close, &gentle );
+ assert( LDAP_CIRCLEQ_EMPTY( &b->b_preparing ) );
+ assert( b->b_opening == ( b->b_cookie ? 1 : 0 ) );
+ b->b_failed = 0;
+
+ connections_walk_last( &b->b_mutex, &b->b_bindconns, b->b_last_bindconn,
+ lload_connection_close, &gentle );
+ assert( gentle || b->b_bindavail == 0 );
+
+ connections_walk_last( &b->b_mutex, &b->b_conns, b->b_last_conn,
+ lload_connection_close, &gentle );
+ assert( gentle || b->b_active == 0 );
+ assert_locked( &b->b_mutex );
+}
+
+void
+lload_backend_destroy( LloadBackend *b )
+{
+ LloadBackend *next = LDAP_CIRCLEQ_LOOP_NEXT( &backend, b, b_next );
+
+ Debug( LDAP_DEBUG_CONNS, "lload_backend_destroy: "
+ "destroying backend uri='%s', numconns=%d, numbindconns=%d\n",
+ b->b_uri.bv_val, b->b_numconns, b->b_numbindconns );
+
+ checked_lock( &b->b_mutex );
+ b->b_numconns = b->b_numbindconns = 0;
+ backend_reset( b, 0 );
+
+ LDAP_CIRCLEQ_REMOVE( &backend, b, b_next );
+ if ( b == next ) {
+ current_backend = NULL;
+ } else {
+ current_backend = next;
+ }
+
+#ifdef BALANCER_MODULE
+ if ( b->b_monitor ) {
+ BackendDB *be;
+ struct berval monitordn = BER_BVC("cn=monitor");
+ int rc;
+
+ be = select_backend( &monitordn, 0 );
+
+ /* FIXME: implement proper subsys shutdown in back-monitor or make
+ * backend just an entry, not a subsys */
+ rc = b->b_monitor->mss_destroy( be, b->b_monitor );
+ assert( rc == LDAP_SUCCESS );
+ }
+#endif /* BALANCER_MODULE */
+ checked_unlock( &b->b_mutex );
+ ldap_pvt_thread_mutex_destroy( &b->b_mutex );
+
+ if ( b->b_retry_event ) {
+ event_del( b->b_retry_event );
+ event_free( b->b_retry_event );
+ b->b_retry_event = NULL;
+ }
+
+ ch_free( b->b_host );
+ ch_free( b->b_uri.bv_val );
+ ch_free( b->b_name.bv_val );
+ ch_free( b );
+}
+
+void
+lload_backends_destroy( void )
+{
+ while ( !LDAP_CIRCLEQ_EMPTY( &backend ) ) {
+ LloadBackend *b = LDAP_CIRCLEQ_FIRST( &backend );
+
+ lload_backend_destroy( b );
+ }
+}