doc: Described the headers added by htparser.

[ashd.git] / doc / htparser.doc

htparser(1)
===========

NAME
----
htparser - Root HTTP server for use with *ashd*(7)

SYNOPSIS
--------
*htparser* [*-hSf*] [*-u* 'USER'] [*-r* 'ROOT'] [*-p* 'PIDFILE'] 'PORTSPEC'... `--` 'ROOT' ['ARGS'...]

DESCRIPTION
-----------

The *htparser* program is the root HTTP server of *ashd*(7). It
listens to specified TCP ports, speaks HTTP with connecting clients,
and passes requests on to the root handler program.

When *htparser* starts, it will first begin listening to all ports
specified by 'PORTSPEC'. Once all ports have been bound successfully,
it will fork off and start the root handler specified by 'ROOT',
searching the *PATH* environment variable if necessary, and passing it
all the 'ARGS' as command-line arguments. Only after that will
*htparser* do any daemonizing or chrooting as specified by options.

The root handler must be a persistent program as specified in
*ashd*(7). If the handler program exits, *htparser* will exit too.

PORT SPECIFICATION
------------------

'PORTSPEC' is given in the form
'HANDLER'[*:*'PAR'[*=*'VAL'][(*,*'PAR'[*=*'VAL'])...]]. The
'PAR'='VAL' pairs are used for specifying key-value arguments to the
'HANDLER'. An example of a valid 'PORTSPEC' is `plain:port=8080`.

Currently, the available 'HANDLERs' are *plain* and *ssl*, for
handling plain TCP connections and SSL/TLS-protected connections,
respectively. For details regarding the arguments that each handler
accept, simply run *htparser* with 'HANDLER':*help*. For example, the
command "`htparser ssl:help`" will display help for the *ssl* handler to
standard output and then exit.

The port specifications must be followed by the `--` argument to
distinguish them from the root handler specification.

OPTIONS
-------

*-h*::

	Print a brief usage message on standard output and exit.

*-S*::

	Log messages to *syslog*(3) instead of standard error.

*-f*::

	Daemonize after all specified ports have been successfully
	bound and the root handler has been started.

*-u*::

	Change UID to 'USER' once all specified ports have been
	successfully bound and the root handler has been
	started. 'USER' must be specified symbolically (i.e. not as a
	numeric UID).

*-r*::

	Change root directory to 'ROOT' once all specified ports have
	been successfully bound and the root handler has been started.

*-p*::

	After having daemonized, write the PID of the new process to
	'PIDFILE'.

X-ASH HEADERS
-------------

*htparser* strips away all headers from incoming requests that begin
 with the `X-Ash-` prefix, and adds the following headers to requests:

*X-Ash-Address*::

	The IP address that the client connected from. May be an IPv6
	address.

*X-Ash-Port*::

	The client-side port number of the TCP connection.

*X-Ash-Server-Address*::

	The IP address of the server where the connection was
	accepted. May be an IPv6 address.

*X-Ash-Server-Port*::

	The server-side port number of the TCP connection.

*X-Ash-Protocol*::

	Either *http* or *https*, depending on whether the request was
	received by the *plain* or the *ssl* handler.

AUTHOR
------
Fredrik Tolf <fredrik@dolda2000.com>

SEE ALSO
--------
*ashd*(7)