fix(nat): panic on nil endpoint

gold/link/listen.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"io"
 	"net"
+	"reflect"
 	"runtime"
 	"strconv"
 	"sync"
@@ -173,7 +174,7 @@ func (m *Me) dispatch(packet *head.Packet, addr p2p.EndPoint, index int, finish
 		packet.Put()
 		return
 	}
-	if p.endpoint == nil || !p.endpoint.Euqal(addr) {
+	if reflect.ValueOf(p.endpoint).IsZero() || !p.endpoint.Euqal(addr) {
 		if m.ep.Network() == "tcp" && !addr.Euqal(p.endpoint) {
 			logrus.Infoln("[listen] @", index, "set endpoint of peer", p.peerip, "to", addr.String())
 			p.endpoint = addr

gold/link/nat.go

@@ -2,6 +2,7 @@ package link
 
 import (
 	"encoding/json"
+	"reflect"
 	"sync/atomic"
 	"time"
 	"unsafe"
@@ -69,7 +70,7 @@ func (l *Link) onNotify(packet []byte) {
 		if err == nil {
 			p, ok := l.me.IsInPeer(peer)
 			if ok {
-				if !p.endpoint.Euqal(addr) {
+				if reflect.ValueOf(p.endpoint).IsZero() || !p.endpoint.Euqal(addr) {
 					p.endpoint = addr
 					logrus.Infoln("[nat] notify set ep of peer", peer, "to", ep)
 				}
@@ -109,7 +110,7 @@ func (l *Link) onQuery(packet []byte) {
 		lnk, ok := l.me.IsInPeer(p)
 		eps := ""
 		if l.me.ep.Network() == "udp" { // udp has real p2p
-			if lnk.endpoint == nil {
+			if reflect.ValueOf(lnk.endpoint).IsZero() {
 				continue
 			}
 			eps = lnk.endpoint.String()
@@ -120,7 +121,7 @@ func (l *Link) onQuery(packet []byte) {
 		if eps == "" {
 			continue
 		}
-		if ok && lnk.endpoint != nil {
+		if ok && !reflect.ValueOf(lnk.endpoint).IsZero() {
 			notify[p] = [2]string{
 				lnk.endpoint.Network(),
 				eps,

gold/link/send.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"math/rand"
+	"reflect"
 
 	"github.com/klauspost/compress/zstd"
 	"github.com/sirupsen/logrus"
@@ -123,7 +124,7 @@ func (l *Link) write(p *head.Packet, teatype uint8, additional uint16, datasz ui
 // write 向 peer 发一个包
 func (l *Link) writeonce(p *head.Packet, teatype uint8, additional uint16, datasz uint32, offset uint16, istransfer, hasmore bool, seq uint32) (int, error) {
 	peerep := l.endpoint
-	if peerep == nil {
+	if reflect.ValueOf(peerep).IsZero() {
 		return 0, errors.New("nil endpoint of " + p.Dst.String())
 	}