From d1e87c8a777d69288900221137582b989df5168c Mon Sep 17 00:00:00 2001
From: tsosunchia <59512455+tsosunchia@users.noreply.github.com>
Date: Wed, 29 May 2024 23:25:20 +0800
Subject: [PATCH] =?UTF-8?q?tcp=E5=BA=94=E7=94=A8pktsize?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 trace/tcp_ipv4.go | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/trace/tcp_ipv4.go b/trace/tcp_ipv4.go
index e173a7d..5482230 100644
--- a/trace/tcp_ipv4.go
+++ b/trace/tcp_ipv4.go
@@ -217,6 +217,7 @@ func (t *TCPTracer) send(ttl int) error {
 		DstIP:    t.DestIP,
 		Protocol: layers.IPProtocolTCP,
 		TTL:      uint8(ttl),
+		Flags:    layers.IPv4DontFragment,
 	}
 	// 使用Uint16兼容32位系统，防止在rand的时候因使用int32而溢出
 	sequenceNumber := uint32(r.Intn(math.MaxUint16))
@@ -237,9 +238,16 @@ func (t *TCPTracer) send(ttl int) error {
 
 	desiredPayloadSize := t.Config.PktSize
 	payload := make([]byte, desiredPayloadSize)
-	copy(buf.Bytes(), payload)
+	// 设置随机种子
+	rand.Seed(time.Now().UnixNano())
 
-	if err := gopacket.SerializeLayers(buf, opts, tcpHeader); err != nil {
+	// 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, tcpHeader, gopacket.Payload(payload)); err != nil {
 		return err
 	}