packet.transport.tcp man page

packet.transport.tcp — TCP module

Description

Decode TCP layer.

RFC  793 TRANSMISSION CONTROL PROTOCOL RFC 2018 TCP Selective Acknowledgment Options RFC 7323 TCP Extensions for High Performance

Classes

class Flags(packet.utils.OptionFlags)

TCP Option flags


Methods defined here:
---------------------

__str__ = str_flags(self)
Display the flag names which are set, e.g., in the above example
the output will be "bit1,bit3" (bit1=1, bit3=1)
Use "__str__ = OptionFlags.str_flags" to have it as the default
string representation

class Option(baseobj.BaseObj)

Option object


Methods defined here:
---------------------

__init__(self, unpack)
Constructor which takes an unpack object as input

class Stream(baseobj.BaseObj)

TCP stream buffer object


Methods defined here:
---------------------

__init__(self, seqno)

add_fragment(self, data, seq)
Add fragment data to stream buffer

missing_fragment(self, seq)
Check if given sequence number is within a missing fragment

class TCP(baseobj.BaseObj)

TCP object

Usage:
    from packet.transport.tcp import TCP

    x = TCP(pktt)

Object definition:

TCP(
    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 = Flags(     # TCP flags:
        rawflags = int,#   Raw 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 = list,    # List of TCP options
    data = string,     # Raw data of payload if unable to decode
)


Methods defined here:
---------------------

__init__(self, pktt)
Constructor

Initialize object's private data.

        pktt:
    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: FIN,ACK'

See Also

baseobj(3), packet.application.dns(3), packet.application.krb5(3), packet.application.rpc(3), packet.unpack(3), packet.utils(3)

Bugs

No known bugs.

Author

Jorge Mora (mora@netapp.com)

Referenced By

packet.internet.ipv4(3), packet.internet.ipv6(3).

14 February 2017 NFStest 2.1.5 tcp 1.5