python如何实时获取tcpdump输出

 # -*- coding: utf-8 -*- # !/usr/bin/env python # sudo tcpdump -tt -l -nn -c 5 -i enp4s0 udp port 514 or 51414 import subprocess cmd = ['sudo', 'tcpdump', '-tt', '-l', '-nn', '-c', '5', '-i', 'enp4s0', 'udp', 'port', '514', 'or', '51414'] proc = subprocess.Popen(cmd, stdout=subprocess.PIPE) while True: line = proc.stdout.readline() line = line.strip() if not line: print('tcpdump finished...') break print(line)

 wenyuanblog@localhost:/home/test/script# python tcpdump_udp.py tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on enp4s0, link-type EN10MB (Ethernet), capture size 262144 bytes 1499774951.124178 IP 192.168.10.210.41974 > 192.168.10.251.514: UDP, length 139 1499774953.125664 IP 192.168.10.210.54995 > 192.168.10.251.51414: UDP, length 139 1499774956.128498 IP 192.168.10.210.56748 > 192.168.10.251.514: UDP, length 139 1499774958.129918 IP 192.168.10.210.53883 > 192.168.10.251.51414: UDP, length 139 1499774961.132921 IP 192.168.10.210.58803 > 192.168.10.251.<b style="color:transparent">来源gao@!dai!ma.com搞$$代^@码!网</b>514: UDP, length 139 5 packets captured 6 packets received by filter 0 packets dropped by kernel tcpdump finished...

 # -*- coding: utf-8 -*- # !/usr/bin/env python # sudo tcpdump -tt -l -nn -c 50 -i enp4s0 udp port 514 or 51414 import subprocess import signal import time import os import re import json class CmdServer: def __init__(self, cmd, timeout=120): ''' :param cmd: 执行命令（列表形式） :param timeout: 任务超时时间（seconds，进程运行超过该时间，kill该进程） :param taskname: 任务名称（根据该任务名称记录命令输出信息） ''' self.cmd = cmd self.timeout = timeout self.base_path = reduce(lambda x, y: os.path.dirname(x), range(1), os.path.abspath(__file__)) self.output_path = os.path.join(self.base_path, 'data.json') self.udp_flow_list = [] self.begin_time = int(time.time()) # 执行tcpdump任务 def run(self): if os.path.exists(self.output_path): with open(self.output_path, 'r') as f: self.udp_flow_list = json.load(f) proc = subprocess.Popen(self.cmd, stdout=subprocess.PIPE) stdout = '' while proc.poll() == None: current_time = int(time.time()) if current_time - self.begin_time >= self.timeout: print('tcpdump timeout...') proc.send_signal(signal.SIGINT) stdout = proc.stdout.read() if proc.poll() is not None and not stdout: print('tcpdump finished...') stdout = proc.stdout.read() stdout_list = stdout.split('\n') if stdout_list: self._merge_data(stdout_list) self._save_data() # 数据合并（新增/更新） def _merge_data(self, stdout_list): for line in stdout_list: line = line.strip() if not line: continue timestamp = int(float(line.split('IP')[0].strip())) * 1000 # 源 src_ip_port_list = re.findall(r'IP(.+?)>', line) if not src_ip_port_list: continue src_ip_port_str = src_ip_port_list[0].strip() src_ip = '.'.join(src_ip_port_str.split('.')[0:4]) # 目的 dst_ip_port_list = re.findall(r'>(.+?):', line) if not dst_ip_port_list: continue dst_ip_port_str = dst_ip_port_list[0].strip() dst_port = dst_ip_port_str.split('.')[-1] # 新增/更新latest_timestamp src_item = filter(lambda x: src_ip == x['src_ip'], self.udp_flow_list) if src_item: src_item[0]['dst_port'] = dst_port src_item[0]['latest_timestamp'] = timestamp else: self.udp_flow_list.append(dict( src_ip=src_ip, dst_port=dst_port, latest_timestamp=timestamp )) # 保存数据 def _save_data(self): # 写入文件 with open(self.output_path, 'w') as f: json.dump(self.udp_flow_list, f, encoding="utf-8", ensure_ascii=False) if __name__ == '__main__': cmd = ['sudo', 'tcpdump', '-tt', '-l', '-nn', '-c', '5', '-i', 'enp4s0', 'udp', 'port', '514', 'or', '51414'] cmd_server = CmdServer(cmd, 10) cmd_server.run()