#
# Copyright Redpill Linpro AS (c) 2015.
#
# (vmodtool requires this format.)
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$Module rfc6052 3 RFC6052 VMOD

DESCRIPTION
===========

This VMOD provides a set of helper functions for dealing with RFC6052
IPv4-embedded IPv6 address in VCL.

It is particularly useful when operating the Varnish Cache in an SIIT-DC
environment.

$Event init
$Function IP extract(PRIV_VCL, IP)

Extracts an IPv4-embedded IPv6 address from IP and returns it. If IP doesn't
contain an IPv4-embedded IPv6 address, returns NULL.

$Function BOOL is_v4embedded(PRIV_VCL, IP)

Checks whether or not IP contains an IPv4-embedded IPv6 address.

$Function VOID prefix(PRIV_VCL, STRING)

Configures the RFC6052 prefix in use. The default is 64:ff9b::/96.  Note: Only
/96 currently supported. Do *not* include the prefix length in STRING.

$Function VOID replace(PRIV_VCL, IP)

Extracts and IPv4-embedded IPv6 address from IP, and uses it to overwrite IP.
If IP doesn't contain an IPv4-embedded IPv6 address, IP is left untouched.

BUGS AND LIMITATIONS
====================

Currently, only /96 prefixes are supported.

Doing rfc6052.replace(client.ip) in vcl_recv doesn't make varnishncsa(1) to
show the embedded IPv4 address. This is (probably) a limitation in Varnish
Cache).

Send any bug reports to the GitHub repo linked to under MORE INFORMATION.

MORE INFORMATION
================

https://github.com/toreanderson/libvmod-rfc6052

https://tools.ietf.org/html/draft-ietf-v6ops-siit-dc