From 61a84f69538e4d19091aef8618e0ad5992958c4e Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 7 Jun 2026 02:24:30 +0500
Subject: [PATCH] engine: cache negative master server DNS failures longer,
 remove dead UDP master server addresses

---
 engine/common/masterlist.c | 29 ++++++++++-------------------
 engine/common/net_ws.c     |  4 ++--
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/engine/common/masterlist.c b/engine/common/masterlist.c
index e5ca9811..512e5f28 100644
--- a/engine/common/masterlist.c
+++ b/engine/common/masterlist.c
@@ -50,8 +50,9 @@ static struct masterlist_s
 
 static CVAR_DEFINE_AUTO( sv_verbose_heartbeats, "0", 0, "print every heartbeat to console" );
 
-#define HEARTBEAT_SECONDS      ((sv_nat.value > 0.0f) ? 60.0f : 300.0f) // 1 or 5 minutes
-#define RESOLVE_EXPIRE_SECONDS (60.0f) // 1 minute to expire
+#define HEARTBEAT_SECONDS               ((sv_nat.value > 0.0f) ? 60.0f : 300.0f) // 1 or 5 minutes
+#define RESOLVE_EXPIRE_SECONDS          (60.0f)  // positive cache: 1 minute
+#define NEGATIVE_RESOLVE_EXPIRE_SECONDS (300.0f) // negative cache: 5 minutes
 
 static size_t NET_BuildMasterServerScanRequest( char *buf, size_t size, uint32_t key, qboolean nat, const char *filter, connprotocol_t proto )
 {
@@ -96,11 +97,10 @@ NET_GetMasterHostByName
 */
 static net_gai_state_t NET_GetMasterHostByName( master_t *m )
 {
-	if( host.realtime > m->resolve_time )
-		m->adr.type = 0;
+	if( host.realtime < m->resolve_time )
+		return m->adr.type ? NET_EAI_OK : NET_EAI_NONAME;
 
-	if( m->adr.type )
-		return NET_EAI_OK;
+	m->adr.type = 0;
 
 	net_gai_state_t res = NET_StringToAdrNB( m->address, &m->adr, m->v6only );
 
@@ -110,10 +110,13 @@ static net_gai_state_t NET_GetMasterHostByName( master_t *m )
 		return res;
 	}
 
-	m->adr.type = 0;
 	if( res == NET_EAI_NONAME )
+	{
 		Con_Reportf( "Can't resolve adr: %s\n", m->address );
+		m->resolve_time = host.realtime + NEGATIVE_RESOLVE_EXPIRE_SECONDS;
+	}
 
+	m->adr.type = 0;
 	return res;
 }
 
@@ -765,17 +768,6 @@ void NET_InitMasters( void )
 
 	Cvar_RegisterVariable( &sv_verbose_heartbeats );
 
-	{ // IPv4-only
-		NET_AddMaster( "mentality.rip:27010" );
-		NET_AddMaster( "ms2.mentality.rip:27010" );
-		NET_AddMaster( "ms3.mentality.rip:27010" );
-	}
-
-	{ // IPv6-only
-		NET_AddMaster( "aaaa.mentality.rip:27010" )->v6only = true;
-		NET_AddMaster( "aaaa.ms2.mentality.rip:27010" )->v6only = true;
-	}
-
 #if 0
 	NET_AddMasterStatic( "http://meltdown.lan/test" );
 #endif
@@ -785,6 +777,5 @@ void NET_InitMasters( void )
 	// FIXME: https raw.githubcontent source
 	// FIXME: cloudflare'd sources both HTTP and HTTPS
 
-
 	NET_LoadMasters();
 }
diff --git a/engine/common/net_ws.c b/engine/common/net_ws.c
index aa7b5bf2..27a2022a 100644
--- a/engine/common/net_ws.c
+++ b/engine/common/net_ws.c
@@ -1777,8 +1777,8 @@ static void NET_DetermineLocalAddress( void )
 	struct sockaddr_storage	address;
 	WSAsize_t		namelen;
 
-	memset( &net_local, 0, sizeof( netadr_t ));
-	memset( &net6_local, 0, sizeof( netadr_t ));
+	memset( &net_local, 0, sizeof( net_local ));
+	memset( &net6_local, 0, sizeof( net6_local ));
 
 	if( !net.allow_ip && !net.allow_ip6 )
 	{