print raw in discv5 and resend the cached encoded challenge raw

p2p/discover/v5_udp.go

@@ -30,6 +30,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/mclock"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p/discover/v5wire"
@@ -763,7 +764,7 @@ func (t *UDPv5) send(toID enode.ID, toAddr netip.AddrPort, packet v5wire.Packet,
 		t.log.Warn(">> "+packet.Name(), t.logcontext...)
 		return nonce, err
 	}
-
+	t.logcontext = append(t.logcontext, "rawpacket", hexutil.Encode(enc))
 	_, err = t.conn.WriteToUDPAddrPort(enc, toAddr)
 	t.log.Trace(">> "+packet.Name(), t.logcontext...)
 	return nonce, err
@@ -808,6 +809,7 @@ func (t *UDPv5) dispatchReadPacket(from netip.AddrPort, content []byte) bool {
 // handlePacket decodes and processes an incoming packet from the network.
 func (t *UDPv5) handlePacket(rawpacket []byte, fromAddr netip.AddrPort) error {
 	addr := fromAddr.String()
+	t.log.Trace("<< "+addr, "rawPacket", hexutil.Encode(rawpacket))
 	fromID, fromNode, packet, err := t.codec.Decode(rawpacket, addr)
 	if err != nil {
 		if t.unhandled != nil && v5wire.IsInvalidHeader(err) {

p2p/discover/v5wire/encoding.go

@@ -189,6 +189,9 @@ func (c *Codec) Encode(id enode.ID, addr string, packet Packet, challenge *Whoar
 	)
 	switch {
 	case packet.Kind() == WhoareyouPacket:
+		if sentWhoareyou := c.sc.getHandshake(id, addr); sentWhoareyou != nil {
+			return sentWhoareyou.encoded, sentWhoareyou.Nonce, nil
+		}
 		head, err = c.encodeWhoareyou(id, packet.(*Whoareyou))
 	case challenge != nil:
 		// We have an unanswered challenge, send handshake.
@@ -215,10 +218,17 @@ func (c *Codec) Encode(id enode.ID, addr string, packet Packet, challenge *Whoar
 	// Encode header data.
 	c.writeHeaders(&head)
 
+	var enc []byte
 	// Store sent WHOAREYOU challenges.
 	if challenge, ok := packet.(*Whoareyou); ok {
 		challenge.ChallengeData = bytesCopy(&c.buf)
+		enc, err = c.EncodeRaw(id, head, msgData)
+		if err != nil {
+			return nil, Nonce{}, err
+		}
+		challenge.encoded = enc
 		c.sc.storeSentHandshake(id, addr, challenge)
+		return enc, head.Nonce, err
 	} else if msgData == nil {
 		headerData := c.buf.Bytes()
 		msgData, err = c.encryptMessage(session, packet, &head, headerData)
@@ -226,8 +236,7 @@ func (c *Codec) Encode(id enode.ID, addr string, packet Packet, challenge *Whoar
 			return nil, Nonce{}, err
 		}
 	}
-
+	enc, err = c.EncodeRaw(id, head, msgData)
-	enc, err := c.EncodeRaw(id, head, msgData)
 	return enc, head.Nonce, err
 }
 

p2p/discover/v5wire/msg.go

@@ -73,6 +73,7 @@ type (
 		Node *enode.Node
 
 		sent    mclock.AbsTime // for handshake GC.
+		encoded []byte         // Encoded packet raw data for sending out
 	}
 
 	// PING is sent during liveness checks.