/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
/* proxy_add_forward module
*
* This module adds a 'X-Forwarded-For' header to outgoing
* proxy requests like Squid does.
*
* You can then get the client ip back on the "proxied host" by
* setting r->connection->remote_ip from this header.
*
* Ask Bjoern Hansen <ask@netcetera.dk>, October 1998
* Changes:
*
* April 12 2000: Changed the license to the ASF 1.1 license.
*
* April 12 2000: Made it so that we append our IP to an existing
* "X-Forwarded-For" line instead of clobbering an
* existing one. - <ahosey@systhug.com>
*
* June 8 1999: Added instructions on how to compile it into the
* frontend apache
*
* April 12 1999: Changed the sample code so it doesn't confuse the
* C compiler, ydkhr! Thanks to Mike Whitaker for
* noticing.
*
* March 1 1999: Added sample code on how to use the header with
* mod_perl
*
To use the module you have to compile it into the frontend part of
your server, I usually copy the module to apache-1.3/src/modules/extra/
and use APACI like:
./configure --prefix=/usr/local/apache \
--activate-module=src/modules/extra/mod_proxy_add_forward.c \
--enable-module=proxy_add_forward [... more apaci options ...]
You should also be able to compile and use this module as a
dynamically loaded module (DSO).
TMTOWTDI, but I usually make the 'backend' part of the system
something like the following:
in startup.pl:
sub My::ProxyRemoteAddr ($) {
my $r = shift;
# we'll only look at the X-Forwarded-For header if the requests
# comes from our proxy at localhost
return OK unless ($r->connection->remote_ip eq "127.0.0.1");
if (my ($ip) = $r->header_in('X-Forwarded-For') =~ /([^,\s]+)$/) {
$r->connection->remote_ip($ip);
}
return OK;
}
And in httpd.conf:
PerlPostReadRequestHandler My::ProxyRemoteAddr
*/
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
module MODULE_VAR_EXPORT proxy_add_forward_module;
static int add_forward_header(request_rec *r)
{
const char *oldvalue;
if (r->proxyreq) {
/* If there is an existing header, append our IP to that. */
if (oldvalue = ap_table_get(r->headers_in, "X-Forwarded-For")) {
ap_table_set(r->headers_in, "X-Forwarded-For",
ap_pstrcat(r->pool, oldvalue, ", ",
r->connection->remote_ip, NULL));
}
else {
ap_table_set(r->headers_in, "X-Forwarded-For",
r->connection->remote_ip);
}
return OK;
}
return DECLINED;
}
module MODULE_VAR_EXPORT proxy_add_forward_module = {
STANDARD_MODULE_STUFF,
NULL, /* initializer */
NULL, /* dir config creater */
NULL, /* dir merger --- default is to override */
NULL, /* server config */
NULL, /* merge server configs */
NULL, /* command table */
NULL, /* handlers */
NULL, /* filename translation */
NULL, /* check_user_id */
NULL, /* check auth */
NULL, /* check access */
NULL, /* type_checker */
add_forward_header, /* fixups */
NULL, /* logger */
NULL, /* header parser */
NULL, /* child_init */
NULL, /* child_exit */
NULL /* post read-request */
};