mod_proxy/2739: Forward the client IP address to back-end server when proxying request

[Johan van Reijendam <jv...@systems.dhl.com>]

>Number:         2739
>Category:       mod_proxy
>Synopsis:       Forward the client IP address to back-end server when proxying request
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          change-request
>Submitter-Id:   apache
>Arrival-Date:   Wed Jul 29 12:20:00 PDT 1998
>Last-Modified:
>Originator:     jvanreij@systems.dhl.com
>Organization:
apache
>Release:        1.3.0
>Environment:
Change was tested on HPUX-10.20 and Solaris 2.[5-6] using
Apache-1.3b2, 1.3.0
>Description:
We currently use Apache to reverse proxy an increasing number of internal
web sites. When requests are proxied however there is little or no info
available to the back-end server to perform statistical analysis regarding what
users are hitting what pages.
In order to remedy this a change was made to the mod_proxy.c module to make it
possible to forward the IP address of the connecting browser/client.
This information is placed in an additional HTTP header sent to the back-end
host.

Please let me know if this is an acceptable submission.
Regards
>How-To-Repeat:

>Fix:
diff -C3 output :
--------8<-------
*** mod_proxy-old.c     Wed Jul 29 12:01:02 1998
--- mod_proxy.c Wed Jul 29 12:04:34 1998
***************
*** 195,200 ****
--- 195,207 ----
                                   r->uri + len, NULL);
             r->handler = "proxy-server";
             r->proxyreq = 1;
+ 
+            /* Add client IP to headers */
+ 
+            if ( conf->forward_client_ip ) {
+                table_set( r->headers_out, "Client_IP", r->connection->remote_ip );
+            }
+ 
             return OK;
        }
      }
***************
*** 577,582 ****
--- 584,600 ----
  }
  
  static const char *
+      forward_client_ip(cmd_parms *parms, void *dummy, int flag)
+ {
+     proxy_server_conf *psf =
+     get_module_config(parms->server->module_config, &proxy_module);
+ 
+     psf->forward_client_ip = flag;
+     return NULL;
+ }
+ 
+ 
+ static const char *
       set_proxy_req(cmd_parms *parms, void *dummy, int flag)
  {
      proxy_server_conf *psf =
***************
*** 783,788 ****
--- 801,808 ----
       "The number of characters in subdirectory names"},
      {"NoCache", set_cache_exclude, NULL, RSRC_CONF, ITERATE,
       "A list of names, hosts or domains for which caching is *not* provided"},
+     {"ForwardClientIP", forward_client_ip, NULL, RSRC_CONF, FLAG,
+      "on if the client ip address should be forwarded"},
      {NULL}
  };
  
---------8<--------
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