Question

我遇到的情况是，当我使用子进程python模块时，“tcprewrite”的代码无法一直执行，除非我删除代码行并再次重写然后运行程序。然后运行一次，然后在剩下的时间内开始失败。我从来没有“tshark”命令的问题。此外，当我从python解释器运行此命令时，它总是像魅力一样工作。只有当我从Python模块运行它时，才遇到这个问题。

command4 = 'tcprewrite --dstipmap=' + natted_clients_ip + ':' + clients_ip + ' 
--portmap=' + s2c_dport_to_be_changed + ':' + c2s_sport + ' --infile=s2c-' + 
rx_stage_pcap + ' --outfile=trw-s2c-' + rx_stage_pcap
p4 = subprocess.Popen(command4,shell=True,bufsize=-1,stdout=subprocess.PIPE)
p4.terminate()

command41 = 'tshark -r trw-s2c-' + rx_stage_pcap
p41 = subprocess.Popen(command41,shell=True,bufsize=-1,stdout=subprocess.PIPE)
p41_stdout = p41.communicate()[0]
print('\n\ttrw-s2c-'+rx_stage_pcap+'\n' )
print(p41_stdout.decode('utf-8'))
p41.terminate()

这是一个输出当它只运行一次时，子进程模块成功运行“tcprewrite”命令，我们能够看到新pcap文件的内容（由tcprewrite命令创建）使用“tshark -r”命令。

（以下是传递的变量的值，这是command4的样子，rx_stage_pcap =“test2.pcap”，natted_clients_ip =“10.73.65.90”，clients_ip =“172.20.100.143”，s2c_dport_to_be_changed =“ 50122“，c2s_sport =”53264“）

>>>
>>> command4 = 'tcprewrite --dstipmap=' + natted_clients_ip + ':' + clients_ip + ' --portmap=' + s2c_dport_to_be_changed + ':' + c2s_sport + ' --infile=s2c-' + rx_stage_pcap + ' --outfile=trw-s2c-' + rx_stage_pcap
>>> command4
'tcprewrite --dstipmap=10.73.65.90:172.20.100.143 --portmap=50122:53264 --infile=s2c-test2.pcap --outfile=trw-s2c-test2.pcap'
>>>

S2C-test2.pcap

1   0.000000 213.211.198.62  10.73.65.90  TCP 66 80  50122 [SYN, ACK] Seq=0 Ack=1 Win=29200 Len=0 MSS=1460 SACK_PERM=1 WS=128
2   0.131879 213.211.198.62  10.73.65.90  TCP 54 80  50122 [ACK] Seq=1 Ack=561 Win=30336 Len=0
3   0.154104 213.211.198.62  10.73.65.90  TCP 1514 [TCP segment of a reassembled PDU]
4   0.154226 213.211.198.62  10.73.65.90  TCP 1514 [TCP segment of a reassembled PDU]
5   0.154346 213.211.198.62  10.73.65.90  TCP 63 [TCP Previous segment not captured] [TCP segment of a reassembled PDU]
6   0.154355 213.211.198.62  10.73.65.90  TCP 1514 [TCP Out-Of-Order] 80  50122 [ACK] Seq=2921 Ack=561 Win=30336 Len=1460

TRW-S2C-test2.pcap

1   0.000000 213.211.198.62  172.20.100.143 TCP 66 80  53264 [SYN, ACK] Seq=0 Ack=1 Win=29200 Len=0 MSS=1460 SACK_PERM=1 WS=128
2   0.131879 213.211.198.62  172.20.100.143 TCP 54 80  53264 [ACK] Seq=1 Ack=561 Win=30336 Len=0
3   0.154104 213.211.198.62  172.20.100.143 TCP 1514 [TCP segment of a reassembled PDU]
4   0.154226 213.211.198.62  172.20.100.143 TCP 1514 [TCP segment of a reassembled PDU]
5   0.154346 213.211.198.62  172.20.100.143 TCP 63 [TCP Previous segment not captured] [TCP segment of a reassembled PDU]
6   0.154355 213.211.198.62  172.20.100.143 TCP 1514 [TCP Out-Of-Order] 80  53264 [ACK] Seq=2921 Ack=561 Win=30336 Len=1460

但是当我再次为同一个pcap文件重新运行程序时，它会失败，如下所示：

S2C-test2.pcap

1   0.000000 213.211.198.62  10.73.65.90  TCP 66 80  50122 [SYN, ACK] Seq=0 Ack=1 Win=29200 Len=0 MSS=1460 SACK_PERM=1 WS=128
2   0.131879 213.211.198.62  10.73.65.90  TCP 54 80  50122 [ACK] Seq=1 Ack=561 Win=30336 Len=0
3   0.154104 213.211.198.62  10.73.65.90  TCP 1514 [TCP segment of a reassembled PDU]
4   0.154226 213.211.198.62  10.73.65.90  TCP 1514 [TCP segment of a reassembled PDU]
5   0.154346 213.211.198.62  10.73.65.90  TCP 63 [TCP Previous segment not captured] [TCP segment of a reassembled PDU]
6   0.154355 213.211.198.62  10.73.65.90  TCP 1514 [TCP Out-Of-Order] 80  50122 [ACK] Seq=2921 Ack=561 Win=30336 Len=1460

tshark: The file "trw-s2c-test2.pcap" doesn't exist.

trw-s2c-test2.pcap

有人可以帮我解决在子进程上传递tcprewrite命令时如何始终获得一致的结果。

使用os.system调用或shlex来解析命令并传递给子进程时，我遇到了类似的问题：

cm4 = shlex.split("tcprewrite --dstipmap=%s:%s --portmap=%s:%s --infile=s2c-%s --outfile=trw-s2c-%s" %(natted_clients_ip,clients_ip,s2c_dport_to_be_changed,c2s_sport,rx_stage_pcap,rx_stage_pcap))
    c4= subprocess.Popen(cm4)
    c4.terminate()

    command41 = 'tshark -r trw-s2c-' + rx_stage_pcap
    p41 = subprocess.Popen(command41,shell=True,bufsize=-1,stdout=subprocess.PIPE)
    p41_stdout = p41.communicate()[0]
    print('\n\ttrw-s2c-'+rx_stage_pcap+'\n' )
    print(p41_stdout.decode('utf-8'))
    p41.terminate()

使用子进程命令运行的tcprewrite命令只运行一次，但其他时间无法运行

0 个答案: