Use discover_ptr_endpoints for PTR resolver

internal/clientinfo/client_info.go

@@ -3,9 +3,7 @@ package clientinfo
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/netip"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -185,24 +183,9 @@ func (t *Table) init() {
 	// PTR lookup.
 	if t.discoverPTR() {
 		t.ptr = &ptrDiscover{resolver: ctrld.NewPrivateResolver()}
-		if len(t.svcCfg.DiscoverPtrEndpoints) > 0 {
-			nss := make([]string, 0, len(t.svcCfg.DiscoverPtrEndpoints))
-			for _, ns := range t.svcCfg.DiscoverPtrEndpoints {
-				host, port := ns, "53"
-				if h, p, err := net.SplitHostPort(ns); err == nil {
-					host, port = h, p
-				}
-				// Only use valid ip:port pair.
-				if _, portErr := strconv.Atoi(port); portErr == nil && port != "0" && net.ParseIP(host) != nil {
-					nss = append(nss, net.JoinHostPort(host, port))
-				} else {
-					ctrld.ProxyLogger.Load().Warn().Msgf("ignoring invalid nameserver for ptr discover: %q", ns)
-				}
-			}
-			if len(nss) > 0 {
-				t.ptr.resolver = ctrld.NewResolverWithNameserver(nss)
-				ctrld.ProxyLogger.Load().Debug().Msgf("using nameservers %v for ptr discovery", nss)
-			}
+		if r := t.svcCfg.PtrResolver(); r != nil {
+			ctrld.ProxyLogger.Load().Debug().Msgf("using nameservers %v for PTR discover", t.svcCfg.DiscoverPtrEndpoints)
+			t.ptr.resolver = r
 		}
 		ctrld.ProxyLogger.Load().Debug().Msg("start ptr discovery")
 		if err := t.ptr.refresh(); err != nil {