This is automatically generated documentation. Edit after the "COMMENTS" heading; changes to the main body will be lost.

CheckGREHeader Element Documentation

NAME

CheckGREHeader -- Click element; checks GRE header

SYNOPSIS

CheckGREHeader([keywords OFFSET, CHECKSUM, KEY, SEQUENCE, VERBOSE, DETAILS])

Ports: 1 input, 1-2 outputs
Processing: agnostic
Package: iias

DESCRIPTION

Input packets should have GRE headers starting OFFSET bytes in. Default OFFSET is zero. Checks that the packet's length is reasonable, and that the GRE version, checksum, key, and sequence fields are valid. CheckGREHeader emits valid packets on output 0. Invalid packets are pushed out on output 1, unless output 1 was unused; if so, drops invalid packets. CheckGREHeader prints a message to the console the first time it encounters an incorrect GRE packet (but see VERBOSE below). Keyword arguments are:

CHECKSUM
Boolean. If true, then check each header's checksum for presence and validity. Default is false.
KEY
Unsigned. If not 0, check each header's key field for presence and validity (equal to this value). Default is false.
SEQUENCE
Boolean. If true, then check each header's sequence number for presence and validity. Default is false.
OFFSET
Unsigned integer. Byte position at which the IP header begins. Default is 0.
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 CheckGREHeader 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 CheckGREHeader has seen.
drop_details (read-only)
Returns a text file showing how many erroneous packets CheckGREHeader has seen, subdivided by error. Only available if the DETAILS keyword argument was true.

SEE ALSO

GREEncap, StripGREHeader

Generated by 'click-elem2man' from 'gre/checkgreheader.hh:27' on 17/Jan/2012.

COMMENTS

 
elements/checkgreheader.txt · Last modified: 2012/01/17 10:23 (external edit)
 
Recent changes RSS feed Driven by DokuWiki