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Python how to send a gtp packet using scapy. I tried converting the existing hex stream of gtp message but not able to create it properly


Python how to send a gtp packet using scapy. I tried converting the existing hex stream of gtp message but not able to create it properly. some links are there but not ans is on it. scapy not parsing GTP layers


Solution

  • Quick example just tried, first hex stream is as below

    000c29dad1de000c29e3c64d08004500007c00004000401167bbc0a828b3c0a828b2086808680068bf6432ff00580000000128db0000450000540000400040015ea5ca0b289ec0a828b20800bee70000287b0411204bf43d0d0008090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f3031323334353637
    

    enter scapy interactive mode and assign the above hex stream to a variable,

    a = '000c29dad1de000c29e3c64d08004500007c00004000401167bbc0a828b3c0a828b2086808680068bf6432ff00580000000128db0000450000540000400040015ea5ca0b289ec0a828b20800bee70000287b0411204bf43d0d0008090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f3031323334353637'
    b = a.decode('hex')
    B = Ether(b)
    B.show()
    ###[ Ethernet ]###
      dst= 00:0c:29:da:d1:de
      src= 00:0c:29:e3:c6:4d
      type= 0x800
    ###[ IP ]###
         version= 4L
         ihl= 5L
         tos= 0x0
         len= 124
         id= 0
         flags= DF
         frag= 0L
         ttl= 64
         proto= udp
         chksum= 0x67bb
         src= 192.168.40.179
         dst= 192.168.40.178
         \options\
    ###[ UDP ]###
            sport= 2152
            dport= 2152
            len= 104
            chksum= 0xbf64
    ###[ Raw ]###
               load= '2\xff\x00X\x00\x00\x00\x01(\xdb\x00\x00E\x00\x00T\x00\x00@\x00@\x01^\xa5\xca\x0b(\x9e\xc0\xa8(\xb2\x08\x00\xbe\xe7\x00\x00({\x04\x11 K\xf4=\r\x00\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./01234567'
    

    here scapy does not dissect and show GPRS, but we can still send out, i.e. windows nc

    send(B, iface='Intel(R) Dual Band Wireless-N 7260')
    

    so the packet sent out with the interface, showing by wireshark is as enter image description here