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#22 SIP over TCP

trunk
pending-accepted
Aex Aey
None
5
2019-04-24
2015-11-19
James Rose
No

Does pcapsipdump capture TCP SIP traffic? It seems it isn't. Please advise (and thanks!)

Discussion

  • Abdelaziz Boucherka

    Hi James,

    pcapsipdump do not support yet SIP over TCP.
    Bellow the condition in the capture main loop.

    header_ip=(iphdr )((char)pkt_data+offset_to_ip);
    if (header_ip->protocol==17){//UPPROTO_UDP=17

    regards,
    A.B

     
  • Josh Nankin

    Josh Nankin - 2016-09-07

    +1 for this! Would be great to be able to use SIP TCP

     
  • Aex Aey

    Aex Aey - 2016-12-05

    Very basic tcp support, i.e. some dirty hack that omits syn/syn+ack and only work if SIP messages always start a new segment and every segment is smaller than MSS - should be very easy to impletemt - 5-10 lines of code, maybe.

    Proper tcp support with segment reassembly, reordering handling, etc. is a bit more daunting.

     

    Last edit: Aex Aey 2016-12-05
  • jungle boogie

    jungle boogie - 2016-12-06

    I'm happy to perform any testing with the code to ensure it works correctly.

     
  • Aex Aey

    Aex Aey - 2017-06-26
    • status: open --> pending-accepted
    • assigned_to: Aex Aey
     
  • Aex Aey

    Aex Aey - 2017-06-26

    For really crude TCP support, check out [r128]. Known problems:
    1. SYN, empty ACK, FIN, RST and keepalive packets are omitted;
    2. when SIP (+SDP) are long enough to be split into multiple segments, only first segment is recorded;
    3. if ip/port allocation lines of SDP happen to be beyong first TCP segment, RTP defined in that SDP is omitted.

     

    Related

    Commit: [r128]

  • Daniel Greenwald

    We are finding that in case #2 large tcp packets (eg INVITE w/ SDP + AUTH) are not included in the capture file at all. Both segments are dropped.

     
  • Daniel Greenwald

    Actually we are able to see the first segment by turning off TCP reassembly:
    For the benefit of others:
    right click on Transmission Contol Protocol>Protocol Prefences> turn off Allow Subdissectors to Reassemble

     
  • Daniel Greenwald

    TCP support appears to be broken in r143 and forward. Only the first INVITE packet is captured. It works in r142. Thanks!

     
  • Aex Aey

    Aex Aey - 2019-04-24

    Should be fixed in [r146], thanks for reporting!

     

    Related

    Commit: [r146]

    • Daniel Greenwald

      Indeed, it works. Thanks for the speedy fix!

       

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