From 84b709de447bbd9f4acf6d51f91d158055000546 Mon Sep 17 00:00:00 2001
From: tsosunchia <59512455+tsosunchia@users.noreply.github.com>
Date: Wed, 29 May 2024 22:39:12 +0800
Subject: [PATCH] =?UTF-8?q?udptrace=20pktsize=E9=97=AE=E9=A2=98=E4=BF=AE?=
 =?UTF-8?q?=E6=AD=A3=E4=B8=94=E9=BB=98=E8=AE=A4=E5=8F=91=E5=8C=85=E9=97=B4?=
 =?UTF-8?q?=E9=9A=94=E8=B0=83=E5=B0=8F?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 cmd/cmd.go   |  4 +--
 trace/udp.go | 72 +++++++++++++++++++++++++++++-----------------------
 2 files changed, 42 insertions(+), 34 deletions(-)

diff --git a/cmd/cmd.go b/cmd/cmd.go
index 41aff3d..32ec6be 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -61,8 +61,8 @@ func Excute() {
 	srcAddr := parser.String("s", "source", &argparse.Options{Help: "Use source src_addr for outgoing packets"})
 	srcDev := parser.String("D", "dev", &argparse.Options{Help: "Use the following Network Devices as the source address in outgoing packets"})
 	//router := parser.Flag("R", "route", &argparse.Options{Help: "Show Routing Table [Provided By BGP.Tools]"})
-	packetInterval := parser.Int("z", "send-time", &argparse.Options{Default: 100, Help: "Set how many [milliseconds] between sending each packet.. Useful when some routers use rate-limit for ICMP messages"})
-	ttlInterval := parser.Int("i", "ttl-time", &argparse.Options{Default: 500, Help: "Set how many [milliseconds] between sending packets groups by TTL. Useful when some routers use rate-limit for ICMP messages"})
+	packetInterval := parser.Int("z", "send-time", &argparse.Options{Default: 50, Help: "Set how many [milliseconds] between sending each packet.. Useful when some routers use rate-limit for ICMP messages"})
+	ttlInterval := parser.Int("i", "ttl-time", &argparse.Options{Default: 50, Help: "Set how many [milliseconds] between sending packets groups by TTL. Useful when some routers use rate-limit for ICMP messages"})
 	timeout := parser.Int("", "timeout", &argparse.Options{Default: 1000, Help: "The number of [milliseconds] to keep probe sockets open before giving up on the connection."})
 	packetSize := parser.Int("", "psize", &argparse.Options{Default: 52, Help: "Set the packet size (payload size)"})
 	str := parser.StringPositional(&argparse.Options{Help: "IP Address or domain name"})
diff --git a/trace/udp.go b/trace/udp.go
index eaf09d3..e3d2dcf 100644
--- a/trace/udp.go
+++ b/trace/udp.go
@@ -2,6 +2,7 @@ package trace
 
 import (
 	"log"
+	"math/rand"
 	"net"
 	"sync"
 	"time"
@@ -169,46 +170,53 @@ func (t *UDPTracer) send(ttl int) error {
 	srcIP, srcPort, udpConn := t.getUDPConn(0)
 	defer udpConn.Close()
 
-	var payload []byte
-	if t.Quic {
-		payload = GenerateQuicPayloadWithRandomIds()
-	} else {
-		ipHeader := &layers.IPv4{
-			SrcIP:    srcIP,
-			DstIP:    t.DestIP,
-			Protocol: layers.IPProtocolUDP,
-			TTL:      uint8(ttl),
-		}
-
-		udpHeader := &layers.UDP{
-			SrcPort: layers.UDPPort(srcPort),
-			DstPort: layers.UDPPort(t.DestPort),
-		}
-		_ = udpHeader.SetNetworkLayerForChecksum(ipHeader)
-		buf := gopacket.NewSerializeBuffer()
-		opts := gopacket.SerializeOptions{
-			ComputeChecksums: true,
-			FixLengths:       true,
-		}
-
-		desiredPayloadSize := t.Config.PktSize
-		payload := make([]byte, desiredPayloadSize)
-		copy(buf.Bytes(), payload)
-
-		if err := gopacket.SerializeLayers(buf, opts, udpHeader); err != nil {
-			return err
-		}
-
-		payload = buf.Bytes()
+	//var payload []byte
+	//if t.Quic {
+	//	payload = GenerateQuicPayloadWithRandomIds()
+	//} else {
+	ipHeader := &layers.IPv4{
+		SrcIP:    srcIP,
+		DstIP:    t.DestIP,
+		Protocol: layers.IPProtocolUDP,
+		TTL:      uint8(ttl),
 	}
 
+	udpHeader := &layers.UDP{
+		SrcPort: layers.UDPPort(srcPort),
+		DstPort: layers.UDPPort(t.DestPort),
+	}
+	_ = udpHeader.SetNetworkLayerForChecksum(ipHeader)
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{
+		ComputeChecksums: true,
+		FixLengths:       true,
+	}
+
+	desiredPayloadSize := t.Config.PktSize
+	payload := make([]byte, desiredPayloadSize)
+	// 设置随机种子
+	rand.Seed(time.Now().UnixNano())
+
+	// 填充随机数
+	for i := range payload {
+		payload[i] = byte(rand.Intn(256))
+	}
+	//copy(buf.Bytes(), payload)
+
+	if err := gopacket.SerializeLayers(buf, opts, udpHeader, gopacket.Payload(payload)); err != nil {
+		return err
+	}
+
+	//payload = buf.Bytes()
+	//}
+
 	err = ipv4.NewPacketConn(udpConn).SetTTL(ttl)
 	if err != nil {
 		return err
 	}
 
 	start := time.Now()
-	if _, err := udpConn.WriteTo(payload, &net.UDPAddr{IP: t.DestIP, Port: t.DestPort}); err != nil {
+	if _, err := udpConn.WriteTo(buf.Bytes(), &net.UDPAddr{IP: t.DestIP, Port: t.DestPort}); err != nil {
 		return err
 	}