[client] Filter DNS fallback upstreams matching our server IP to prevent loops (#6183)

This commit is contained in:
Viktor Liu
2026-06-09 19:26:03 +09:00
committed by GitHub
parent 367d37050b
commit d56859dc5d

View File

@@ -777,13 +777,24 @@ func (s *DefaultServer) applyHostConfig() {
// context is released rather than leaked until GC.
func (s *DefaultServer) registerFallback() {
originalNameservers := s.hostManager.getOriginalNameservers()
if len(originalNameservers) == 0 {
serverIP := s.service.RuntimeIP()
var servers []netip.AddrPort
for _, ns := range originalNameservers {
if ns == serverIP {
log.Debugf("skipping original nameserver %s as it is the same as the server IP %s", ns, serverIP)
continue
}
servers = append(servers, netip.AddrPortFrom(ns, DefaultPort))
}
if len(servers) == 0 {
log.Debugf("no fallback upstreams to register; clearing PriorityFallback handler")
s.clearFallback()
return
}
log.Infof("registering original nameservers %v as upstream handlers with priority %d", originalNameservers, PriorityFallback)
log.Infof("registering original nameservers %v as upstream handlers with priority %d", servers, PriorityFallback)
handler, err := newUpstreamResolver(
s.ctx,
@@ -797,11 +808,6 @@ func (s *DefaultServer) registerFallback() {
return
}
handler.selectedRoutes = s.selectedRoutes
var servers []netip.AddrPort
for _, ns := range originalNameservers {
servers = append(servers, netip.AddrPortFrom(ns, DefaultPort))
}
handler.addRace(servers)
prev := s.fallbackHandler