This is automatically generated documentation. Edit after the "COMMENTS" heading; changes to the main body will be lost.
CheckIPHeader -- Click element; checks IP header
CheckIPHeader([OFFSET, keywords OFFSET, INTERFACES, BADSRC,
GOODDST, CHECKSUM, VERBOSE, DETAILS])
Ports: 1 input, 1-2 outputs
Processing: agnostic, but output 1 is push
Package: ip (core)
Input packets should have IP headers starting OFFSET bytes in. Default OFFSET is zero. Checks that the packet's length is reasonable, and that the IP version, header length, length, and checksum fields are valid. Checks that the IP source address is a legal unicast address, or that the packet is destined for one of this machine's addresses (see below). Shortens packets to the IP length, if the IP length is shorter than the nominal packet length (due to Ethernet padding, for example). Also sets the destination IP address annotation to the actual destination IP address. CheckIPHeader emits valid packets on output 0. Invalid packets are pushed out on output 1, unless output 1 was unused; if so, drops invalid packets. CheckIPHeader checks packets' source addresses for validity if one or more of the INTERFACES, BADSRC, and GOODDST keyword arguments are supplied (RFC1812 5.3.7). CheckIPHeader prints a message to the console the first time it encounters an incorrect IP packet (but see VERBOSE below). Keyword arguments are:
drop_detailshandler. False by default.
CheckIPHeader supports an old configuration syntax: CheckIPHeader([BADSRC2, OFFSET, keywords]) The BADSRC2 argument behaves like the BADSRC keyword, except that if you use this syntax, 0.0.0.0 and 255.255.255.255 considered bad addresses in addition to those explicitly in the list. This syntax is deprecated and should not be used in new configurations.
Generated by 'click-elem2man' from '../elements/ip/checkipheader.hh' on 24/May/2007.