packet.transport.tcp (3) - Linux Manuals

packet.transport.tcp: TCP module


packet.transport.tcp - TCP module


Decode TCP layer.


class Flags(baseobj.BaseObj)

Flags object

Methods defined here:

__init__(self, data)
Constructor which takes a short integer as input

class TCP(baseobj.BaseObj)

TCP object

    from packet.transport.tcp import TCP

    x = TCP(pktt)

Object definition:

    src_port    = int, # Source port
    dst_port    = int, # Destination port
    seq_number  = int, # Sequence number
    ack_number  = int, # Acknowledgment number
    hl          = int, # Data offset or header length (32bit words)
    header_size = int, # Data offset or header length in bytes
    flags_raw   = int, # Raw flags
    flags = Flags(     # Individual flags:
        FIN = int,     #   No more data from sender
        SYN = int,     #   Synchronize sequence numbers
        RST = int,     #   Synchronize sequence numbers
        PSH = int,     #   Push function. Asks to push the buffered
                       #     data to the receiving application
        ACK = int,     #   Acknowledgment field is significant
        URG = int,     #   Urgent pointer field is significant
        ECE = int,     #   ECN-Echo has a dual role:
                       #     SYN=1, the TCP peer is ECN capable.
                       #     SYN=0, packet with Congestion Experienced
                       #     flag in IP header set is received during
                       #     normal transmission
        CWR = int,     #   Congestion Window Reduced
        NS  = int,     #   ECN-nonce concealment protection
    window_size = int, # Window size
    checksum    = int, # Checksum
    urgent_ptr  = int, # Urgent pointer
    seq         = int, # Relative sequence number
    options = string,  # Raw data of TCP options if available
    data = string,     # Raw data of payload if unable to decode

Methods defined here:

__init__(self, pktt)

Initialize object's private data.

Packet trace object (packet.pktt.Pktt) so this layer has access to the parent layers.
__str__(self) String representation of object The representation depends on the verbose level set by debug_repr(). If set to 0 the generic object representation is returned. If set to 1 the representation of the object is condensed: 'TCP 708 -> 2049, seq: 3294175829, ack: 3395739041, ACK,FIN' If set to 2 the representation of the object also includes the length of payload and a little bit more verbose: 'src port 708 -> dst port 2049, seq: 3294175829, ack: 3395739041, len: 0, flags: ACK,FIN'


No known bugs.


Jorge Mora (mora [at]