1TCP(3)                              tcp 1.7                             TCP(3)
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NAME

6       packet.transport.tcp - TCP module
7

DESCRIPTION

9       Decode TCP layer.
10
11       RFC   793 TRANSMISSION CONTROL PROTOCOL RFC 2018 TCP Selective Acknowl‐
12       edgment Options RFC 7323 TCP Extensions for High Performance
13

CLASSES

15   class Flags(packet.utils.OptionFlags)
16       TCP Option flags
17
18
19       Methods defined here:
20       ---------------------
21
22       __str__ = str_flags(self)
23
24   class Option(baseobj.BaseObj)
25       Option object
26
27
28       Methods defined here:
29       ---------------------
30
31       __init__(self, unpack)
32       Constructor which takes an unpack object as input
33
34   class Stream(baseobj.BaseObj)
35       TCP stream buffer object
36
37
38       Methods defined here:
39       ---------------------
40
41       __init__(self, seqno)
42       Constructor
43
44       Initialize object's private data according to the arguments given.
45       Arguments can be given as positional, named arguments or a
46       combination of both.
47
48       add_fragment(self, data, seq)
49       Add fragment data to stream buffer
50
51       missing_fragment(self, seq)
52       Check if given sequence number is within a missing fragment
53
54   class TCP(baseobj.BaseObj)
55       TCP object
56
57       Usage:
58           from packet.transport.tcp import TCP
59
60           x = TCP(pktt)
61
62       Object definition:
63
64       TCP(
65           src_port    = int, # Source port
66           dst_port    = int, # Destination port
67           seq_number  = int, # Sequence number
68           ack_number  = int, # Acknowledgment number
69           hl          = int, # Data offset or header length (32bit words)
70           header_size = int, # Data offset or header length in bytes
71           flags = Flags(     # TCP flags:
72               rawflags = int,#   Raw flags
73               FIN = int,     #   No more data from sender
74               SYN = int,     #   Synchronize sequence numbers
75               RST = int,     #   Synchronize sequence numbers
76               PSH = int,     #   Push function. Asks to push the buffered
77                              #     data to the receiving application
78               ACK = int,     #   Acknowledgment field is significant
79               URG = int,     #   Urgent pointer field is significant
80               ECE = int,     #   ECN-Echo has a dual role:
81                              #     SYN=1, the TCP peer is ECN capable.
82                              #     SYN=0, packet with Congestion Experienced
83                              #     flag in IP header set is received during
84                              #     normal transmission
85               CWR = int,     #   Congestion Window Reduced
86               NS  = int,     #   ECN-nonce concealment protection
87           ),
88           window_size = int, # Window size
89           checksum    = int, # Checksum
90           urgent_ptr  = int, # Urgent pointer
91           seq         = int, # Relative sequence number
92           options = list,    # List of TCP options
93           psize = int,       # Payload data size
94           data = string,     # Raw data of payload if unable to decode
95       )
96
97
98       Methods defined here:
99       ---------------------
100
101       __init__(self, pktt)
102       Constructor
103
104       Initialize object's private data.
105
106
107              pktt:  Packet trace object (packet.pktt.Pktt) so this layer has
108                     access to the parent layers.
109
110       __str__(self)
111       String representation of object
112
113       The representation depends on the verbose level set by debug_repr().
114       If set to 0 the generic object representation is returned.
115       If set to 1 the representation of the object is condensed:
116           'TCP 708 -> 2049, seq: 0xc4592255, ack: 0xca66dda1, ACK,FIN'
117
118       If set to 2 the representation of the object also includes the
119       length of payload and a little bit more verbose:
120           'src port 708 -> dst port 2049, seq: 0xc4592255, ack: 0xca66dda1, len: 0, flags: FIN,ACK'
121

SEE ALSO

123       baseobj(3),   packet.application.dns(3),    packet.application.krb5(3),
124       packet.application.rpc(3),  packet.transport.mpa(3),  packet.unpack(3),
125       packet.utils(3)
126
127

BUGS

129       No known bugs.
130

AUTHOR

132       Jorge Mora (mora@netapp.com)
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136NFStest 3.2                      21 March 2023                          TCP(3)