From e2b04c434ed55768bf5a336957cddf27653c2a49 Mon Sep 17 00:00:00 2001
From: Nadezhda Ivanova <nivanova@symas.com>
Date: Mon, 28 Oct 2024 15:48:33 +0200
Subject: [PATCH] ITS#9186 Add a counter to cn=Listener to track total number
 of established connections since startup

---
 servers/slapd/back-monitor/back-monitor.h |  1 +
 servers/slapd/back-monitor/init.c         |  7 ++++
 servers/slapd/back-monitor/listener.c     | 46 +++++++++++++++++++++++
 servers/slapd/connection.c                |  4 ++
 servers/slapd/daemon.c                    |  1 +
 servers/slapd/slap.h                      |  1 +
 6 files changed, 60 insertions(+)

diff --git a/servers/slapd/back-monitor/back-monitor.h b/servers/slapd/back-monitor/back-monitor.h
index 30851afbb3..e6441f27db 100644
--- a/servers/slapd/back-monitor/back-monitor.h
+++ b/servers/slapd/back-monitor/back-monitor.h
@@ -140,6 +140,7 @@ typedef struct monitor_info_t {
 	AttributeDescription	*mi_ad_monitorConnectionOpsAsync;
 	AttributeDescription	*mi_ad_monitorLogLevel;
 	AttributeDescription	*mi_ad_monitorDebugLevel;
+	AttributeDescription	*mi_ad_monitorTotalListenerConnections;
 
 	/*
 	 * Generic description attribute
diff --git a/servers/slapd/back-monitor/init.c b/servers/slapd/back-monitor/init.c
index 4749946a1d..48e3e630d9 100644
--- a/servers/slapd/back-monitor/init.c
+++ b/servers/slapd/back-monitor/init.c
@@ -1954,6 +1954,13 @@ monitor_back_initialize(
 			"SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 "
 			"USAGE dSAOperation )", SLAP_AT_FINAL|SLAP_AT_HIDE,
 			offsetof(monitor_info_t, mi_ad_monitorDebugLevel) },
+		{ "( 1.3.6.1.4.1.4203.666.1.55.34 "
+			"NAME 'monitorTotalListenerConnections' "
+			"DESC 'monitor total number established of connections per listener since startup' "
+			"SUP monitorCounter "
+			"NO-USER-MODIFICATION "
+			"USAGE dSAOperation )", SLAP_AT_FINAL|SLAP_AT_HIDE,
+			offsetof(monitor_info_t, mi_ad_monitorTotalListenerConnections) },
 		{ NULL, 0, -1 }
 	};
 
diff --git a/servers/slapd/back-monitor/listener.c b/servers/slapd/back-monitor/listener.c
index 63ab3b9061..22ce6b95fa 100644
--- a/servers/slapd/back-monitor/listener.c
+++ b/servers/slapd/back-monitor/listener.c
@@ -27,6 +27,46 @@
 #include "slap.h"
 #include "back-monitor.h"
 
+static int
+monitor_subsys_listener_update(
+	Operation		*op,
+	SlapReply		*rs,
+	Entry           *e )
+{
+	monitor_info_t	*mi = ( monitor_info_t * )op->o_bd->be_private;
+	int i;
+	Listener	**l;
+
+	assert( mi != NULL );
+	assert( e != NULL );
+
+	if ( ( l = slapd_get_listeners() ) == NULL ) {
+		if ( slapMode & SLAP_TOOL_MODE ) {
+			return 0;
+		}
+
+		Debug( LDAP_DEBUG_ANY,
+			"monitor_subsys_listener_update: "
+			"unable to get listeners\n" );
+		return( -1 );
+	}
+
+	for ( i = 0; l[ i ]; i++ ) {
+		char 		buf[ BACKMONITOR_BUFSIZE ];
+		struct berval	sl_bv;
+		struct berval		rdn;
+		dnRdn( &e->e_nname, &rdn );
+		sl_bv.bv_len = snprintf( buf, sizeof( buf ),
+								 "cn=listener %d", i );
+		sl_bv.bv_val = buf;
+		if ( dn_match( &rdn, &sl_bv ) ) {
+			Attribute *a = attr_find( e->e_attrs, mi->mi_ad_monitorTotalListenerConnections );
+			assert( a != NULL );
+			UI2BV( &a->a_vals[ 0 ], l[ i ]->sl_n_conns_opened );
+		}
+	}
+}
+
 int
 monitor_subsys_listener_init(
 	BackendDB		*be,
@@ -52,6 +92,8 @@ monitor_subsys_listener_init(
 		return( -1 );
 	}
 
+	ms->mss_update = monitor_subsys_listener_update;
+
 	mi = ( monitor_info_t * )be->be_private;
 
 	if ( monitor_cache_get( mi, &ms->mss_ndn, &e_listener ) ) {
@@ -87,6 +129,10 @@ monitor_subsys_listener_init(
 		attr_merge_normalize_one( e, slap_schema.si_ad_labeledURI,
 				&l[ i ]->sl_url, NULL );
 
+		ber_str2bv( "0", STRLENOF( "0" ), 0, &bv );
+		attr_merge_normalize_one( e, mi->mi_ad_monitorTotalListenerConnections,
+				&bv, NULL );
+
 #ifdef HAVE_TLS
 		if ( l[ i ]->sl_is_tls ) {
 			struct berval bv;
diff --git a/servers/slapd/connection.c b/servers/slapd/connection.c
index 717934b55e..2766b94193 100644
--- a/servers/slapd/connection.c
+++ b/servers/slapd/connection.c
@@ -537,6 +537,10 @@ Connection * connection_init(
 	slapd_add_internal( s, 1 );
 
 	backend_connection_init(c);
+
+	if ( c->c_listener )
+		ldap_pvt_mp_add_ulong(c->c_listener->sl_n_conns_opened, 1);
+
 	ldap_pvt_thread_mutex_unlock( &c->c_mutex );
 
 	if ( !(flags & CONN_IS_UDP ))
diff --git a/servers/slapd/daemon.c b/servers/slapd/daemon.c
index 2b6d26c7ac..c08e560fcd 100644
--- a/servers/slapd/daemon.c
+++ b/servers/slapd/daemon.c
@@ -1561,6 +1561,7 @@ slap_open_listener(
 	l.sl_tcp_rmem = 0;
 	l.sl_tcp_wmem = 0;
 #endif /* LDAP_TCP_BUFFER */
+	ldap_pvt_mp_init( l.sl_n_conns_opened );
 
 	port = (unsigned short) lud->lud_port;
 
diff --git a/servers/slapd/slap.h b/servers/slapd/slap.h
index d234ac5477..d0d6d69395 100644
--- a/servers/slapd/slap.h
+++ b/servers/slapd/slap.h
@@ -3046,6 +3046,7 @@ struct Listener {
 	int	sl_tcp_rmem;	/* custom TCP read buffer size */
 	int	sl_tcp_wmem;	/* custom TCP write buffer size */
 #endif
+	ldap_pvt_mp_t sl_n_conns_opened; /* total number of connections opened since startup */
 };
 
 /*
-- 
2.47.2