CheckTCPHeader

CheckTCPHeader Element Documentation

NAME

CheckTCPHeader — Click element; checks TCP header on TCP/IP packets

SYNOPSIS

CheckTCPHeader([KEYWORDS])

Ports: 1 input, 1-2 outputs
Processing: agnostic, but output 1 is push

DESCRIPTION

Expects TCP/IP packets as input. Checks that the TCP header length and checksum fields are valid. Pushes invalid packets out on output 1, unless output 1 was unused; if so, drops invalid packets.

Prints a message to the console the first time it encounters an incorrect packet (but see VERBOSE below).

Keyword arguments are:

• VERBOSE — Boolean. If it is true, then a message will be printed for every erroneous packet, rather than just the first. False by default.
• DETAILS — Boolean. If it is true, then CheckTCPHeader will maintain detailed counts of how many packets were dropped for each possible reason, accessible through the drop_details handler. False by default.

ELEMENT HANDLERS

• drops (read-only) — Returns the number of incorrect packets CheckTCPHeader has seen.
• drop_details (read-only) — Returns a text file showing how many erroneous packets CheckTCPHeader has seen, subdivided by error. Only available if the DETAILS keyword argument was true.

SEE ALSO

CheckIPHeader, CheckUDPHeader, CheckICMPHeader, MarkIPHeader

Generated by click-elem2man from ../elements/tcpudp/checktcpheader.hh:7 on 2017/10/17.