Line # Revision Author
1 20 ahitrov@rambler.ru /* ====================================================================
2 * The Apache Software License, Version 1.1
3 *
4 * Copyright (c) 2000 The Apache Software Foundation. All rights
5 * reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 *
19 * 3. The end-user documentation included with the redistribution,
20 * if any, must include the following acknowledgment:
21 * "This product includes software developed by the
22 * Apache Software Foundation (http://www.apache.org/)."
23 * Alternately, this acknowledgment may appear in the software itself,
24 * if and wherever such third-party acknowledgments normally appear.
25 *
26 * 4. The names "Apache" and "Apache Software Foundation" must
27 * not be used to endorse or promote products derived from this
28 * software without prior written permission. For written
29 * permission, please contact apache@apache.org.
30 *
31 * 5. Products derived from this software may not be called "Apache",
32 * nor may "Apache" appear in their name, without prior written
33 * permission of the Apache Software Foundation.
34 *
35 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
36 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 * SUCH DAMAGE.
47 * ====================================================================
48 *
49 * This software consists of voluntary contributions made by many
50 * individuals on behalf of the Apache Software Foundation. For more
51 * information on the Apache Software Foundation, please see
52 * <http://www.apache.org/>.
53 *
54 * Portions of this software are based upon public domain software
55 * originally written at the National Center for Supercomputing Applications,
56 * University of Illinois, Urbana-Champaign.
57 */
58
59 /* proxy_add_forward module
60 *
61 * This module adds a 'X-Forwarded-For' header to outgoing
62 * proxy requests like Squid does.
63 *
64 * You can then get the client ip back on the "proxied host" by
65 * setting r->connection->remote_ip from this header.
66 *
67 * Ask Bjoern Hansen <ask@netcetera.dk>, October 1998
68
69 * Changes:
70 *
71 * April 12 2000: Changed the license to the ASF 1.1 license.
72 *
73 * April 12 2000: Made it so that we append our IP to an existing
74 * "X-Forwarded-For" line instead of clobbering an
75 * existing one. - <ahosey@systhug.com>
76 *
77 * June 8 1999: Added instructions on how to compile it into the
78 * frontend apache
79 *
80 * April 12 1999: Changed the sample code so it doesn't confuse the
81 * C compiler, ydkhr! Thanks to Mike Whitaker for
82 * noticing.
83 *
84 * March 1 1999: Added sample code on how to use the header with
85 * mod_perl
86 *
87
88 To use the module you have to compile it into the frontend part of
89 your server, I usually copy the module to apache-1.3/src/modules/extra/
90 and use APACI like:
91
92 ./configure --prefix=/usr/local/apache \
93 --activate-module=src/modules/extra/mod_proxy_add_forward.c \
94 --enable-module=proxy_add_forward [... more apaci options ...]
95
96 You should also be able to compile and use this module as a
97 dynamically loaded module (DSO).
98
99 TMTOWTDI, but I usually make the 'backend' part of the system
100 something like the following:
101
102 in startup.pl:
103
104 sub My::ProxyRemoteAddr ($) {
105 my $r = shift;
106
107 # we'll only look at the X-Forwarded-For header if the requests
108 # comes from our proxy at localhost
109 return OK unless ($r->connection->remote_ip eq "127.0.0.1");
110
111 if (my ($ip) = $r->header_in('X-Forwarded-For') =~ /([^,\s]+)$/) {
112 $r->connection->remote_ip($ip);
113 }
114
115 return OK;
116 }
117
118 And in httpd.conf:
119
120 PerlPostReadRequestHandler My::ProxyRemoteAddr
121
122 */
123
124
125 #include "httpd.h"
126 #include "http_config.h"
127 #include "http_core.h"
128
129 module MODULE_VAR_EXPORT proxy_add_forward_module;
130
131 static int add_forward_header(request_rec *r)
132 {
133 const char *oldvalue;
134
135 if (r->proxyreq) {
136 /* If there is an existing header, append our IP to that. */
137 if (oldvalue = ap_table_get(r->headers_in, "X-Forwarded-For")) {
138 ap_table_set(r->headers_in, "X-Forwarded-For",
139 ap_pstrcat(r->pool, oldvalue, ", ",
140 r->connection->remote_ip, NULL));
141 }
142 else {
143 ap_table_set(r->headers_in, "X-Forwarded-For",
144 r->connection->remote_ip);
145 }
146 return OK;
147 }
148 return DECLINED;
149 }
150
151 module MODULE_VAR_EXPORT proxy_add_forward_module = {
152 STANDARD_MODULE_STUFF,
153 NULL, /* initializer */
154 NULL, /* dir config creater */
155 NULL, /* dir merger --- default is to override */
156 NULL, /* server config */
157 NULL, /* merge server configs */
158 NULL, /* command table */
159 NULL, /* handlers */
160 NULL, /* filename translation */
161 NULL, /* check_user_id */
162 NULL, /* check auth */
163 NULL, /* check access */
164 NULL, /* type_checker */
165 add_forward_header, /* fixups */
166 NULL, /* logger */
167 NULL, /* header parser */
168 NULL, /* child_init */
169 NULL, /* child_exit */
170 NULL /* post read-request */
171 };
172
173