Apache HTTP Server Version 2.5

Apache > HTTP Server > Documentation > Version 2.5 > Modules

# Apache Module mod_proxy_fdpass

Description: | fdpass external process support module for `mod_proxy`
Status: | Extension
Module Identifier: | proxy_fdpass_module
Source File: | mod_proxy_fdpass.c
Compatibility: | Available for unix in version 2.3 and later

### Summary

This module requires the service of `mod_proxy`. It provides support for the passing the socket of the client to another process.

`mod_proxy_fdpass` uses the ability of AF_UNIX domain sockets to pass an open file descriptor to allow another process to finish handling a request.

The module has a `proxy_fdpass_flusher` provider interface, which allows another module to optionally send the response headers, or even the start of the response body. The default `flush` provider disables keep-alive, and sends the response headers, letting the external process just send a response body.

In order to use another provider, you have to set the `flusher` parameter in the `ProxyPass` directive.

At this time the only data passed to the external process is the client socket. To receive a client socket, call recvfrom with an allocated `struct cmsghdr`. Future versions of this module may include more data after the client socket, but this is not implemented at this time.

### Directives

This module provides no directives.

### Bugfix checklist

- httpd changelog
- Known issues
- Report a bug

### See also

- `mod_proxy`