python - 用 scapy 写入 pcap

Question

过滤掉所有 NBNS 流量后，我正在尝试写入 pcap 文件。这给了我一个语法错误。

from scapy.all import *

Capture = raw_input("Enter file path of pcap file: " )
pcap = rdpcap(Capture)

ports=137

filtered = (pkt for pkt in Capture if
    (UDP in pkt and 
    (pkt[UDP].sport in str(ports)))

wrpcap("filtered.pcap",filtered)

我发现语法错误的答案只是 ...str(ports)))) 末尾缺少一个括号但现在我有一个不同的错误。

  File "receiver2.py", line 18, in <module>
    wrpcap("filtered.pcap",filtered)
  File "/usr/lib/python2.7/dist-packages/scapy/utils.py", 
    line 470, in wrpcap
  PcapWriter(filename, *args, **kargs).write(pkt)
  File "/usr/lib/python2.7/dist-packages/scapy/utils.py", line 652, in write
    for p in pkt:
  File "receiver2.py", line 13, in <genexpr>
    (UDP in pkt and 
  TypeError: 'in <string>' requires string as left operand, not Packet_metaclass

Answer 1

我正在尝试您的脚本，但无法按照编写的方式进行。我对它进行了一些更改，我认为它可以满足您的需求。希望这可以帮助。

from scapy.all import *

capture = raw_input("Enter file path of pcap file: " )
pcap = rdpcap(capture)

ports=137

def write(pkt):
    wrpcap('filtered.pcap', pkt, append=True)  #appends packet to output file

for pkt in pcap:
    if pkt.haslayer(UDP) and pkt.getlayer(UDP).sport == ports:  #checks for UDP layer and sport 137
        write(pkt)  #sends the packet to be written if it meets criteria
    else:
        pass