NetBSD/libexec/httpd/bozohttpd.8

.\"	$NetBSD: bozohttpd.8,v 1.16 2009/11/22 18:40:26 mbalmer Exp $
.\"
.\"	$eterna: bozohttpd.8,v 1.91 2009/05/23 00:55:22 mrg Exp $
.\"
.\" Copyright (c) 1997-2009 Matthew R. Green
.\" 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.
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 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 AUTHOR 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,
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd May 22, 2009
.Dt HTTPD 8
.Os
.Sh NAME
.Nm httpd
.Nd hyper text transfer protocol version 1.1 daemon
.Sh SYNOPSIS
.Nm
.Op Fl befHnrsuVX
.Op Fl C Ar suffix cgihandler
.Op Fl c Ar cgibin
.Op Fl I Ar port
.Op Fl i Ar address
.Op Fl M Ar suffix type encoding encoding11
.Op Fl p Ar pubdir
.Op Fl S Ar server_software
.Op Fl t Ar chrootdir
.Op Fl v Ar virtualroot
.Op Fl x Ar index
.Op Fl Z Ar cert privkey
.Ar slashdir
.Op Ar myname
.Sh DESCRIPTION
The
.Nm
program reads a
.Em HTTP
request from the standard input, and sends a reply to the standard output.
Besides ~user translation and virtual hosting support (see below), all file
requests are from
.Ar slashdir
directory.
The server uses
.Ar myname
as its name, which defaults to the local hostname, obtained from
.Xr gethostname 3
(but see the
.Fl v
option for virtual hosting.)
.Nm
is designed to be small, simple and relatively featureless,
hopefully increasing its security.
.Ss OPTIONS
The following options are available:
.Bl -tag -width xxxcgibin
.It Fl b
This option enables daemon mode, where
.Nm
detaches from the current terminal, running in the background and
servicing HTTP requests.
.It Fl C Ar suffix cgihandler
This option adds a new CGI handler program for a particular file type.
The
.Ar suffix
should be any normal file suffix, and the
.Ar cgihandler
should be a full path to an interpreter.
This option is the only way to enable CGI programs that exist
outside of the cgibin directory to be executed.
Multiple
.Fl C
options may be passed.
.It Fl c Ar cgibin
This option enables the CGI/1.1 interface.
The
.Ar cgibin
directory is expected to contain the CGI programs to be used.
.Nm
looks for URL's in the form of
.Em /cgi-bin/\*[Lt]scriptname\*[Gt]
where
.Aq scriptname
is a valid CGI program in the
.Ar cgibin
directory.
In other words, all CGI URL's must begin with
.Em \%/cgi-bin/ .
Note that the CGI/1.1 interface is not available with
.Em ~user
translation.
.It Fl e
This option causes
.Nm
to not clear the environment when used with either the
.Fl t
or
.Fl U
options.
.It Fl f
This option stops the
.Fl b
flag from
.Nm
detaching from the tty and going into the background.
.It Fl H
This option causes directory index mode to hide files and directories
that start with a period, except for
.Pa .. .
Also see
.Fl X .
.It Fl I Ar port
This option is only valid with the
.Fl b
option.
It causes
.Ar port
to use used as the port to bind daemon mode.
The default is the
.Dq http
port.
.It Fl i Ar address
This option is only valid with the
.Fl b
option.
It causes
.Ar address
to use used as the address to bind daemon mode.
If otherwise unspecified, the address used to bind is derived from the
.Ar myname ,
which defaults to the name returned by
.Xr gethostname 3 .
Only the last
.Fl i
option is used.
.It Fl M Ar suffix type encoding encoding11
This option adds a new entry to the table that converts file suffixes to
content type and encoding.
This option takes four additional arguments containing
the file prefix, its
.Dq Content-Type ,
.Dq Content-Encoding ,
and
.Dq Content-Encoding
for HTTP/1.1 connections, respectively.
If any of these are a single dash
.Pq Dq - ,
the empty string is used instead.
Multiple
.Fl M
options may be passed.
.It Fl n
This option stops
.Nm
from doing IP address to name resolution of hosts for setting the
.Ev REMOTE_HOST
variable before running a CGI program.
This option has no effect without the
.Fl c
option.
.It Fl p Ar pubdir
This option changes the default user directory for
.Em /~user/
translations from
.Dq public_html
to
.Ar pubdir .
.It Fl r
This option forces pages besides the
.Dq index.html
(see the
.Fl X
option) page to require that the Referrer: header be present and
refer to this web server, otherwise a redirect to the
.Dq index.html
page will be returned instead.
.It Fl S Ar server_software
This option sets the internal server version to
.Ar server_software .
.It Fl s
This option forces logging to be set to stderr always.
.It Fl t Ar chrootdir
When this option is used,
.Nm
will chroot to the specified directory
before answering requests.
Every other path should be specified relative
to the new root, if this option is used.
Note that the current environment
is normally replaced with an empty environment with this option, unless the
.Fl e
option is also used.
.It Fl U Ar username
This option causes
.Nm
to switch to the user and the groups of
.Ar username
after initialization.
This option, like
.Fl t
above, causes
.Nm
to clear the environment unless the
.Fl e
option is given.
.It Fl u
This option enables the transformation of Uniform Resource Locators of
the form
.Em /~user/
into the directory
.Pa ~user/public_html
(but see the
.Fl p
option above).
.It Fl V
This option sets the default virtual host directory to
.Ar slashdir .
If no directory exists in
.Ar virtualroot
for the request, then
.Ar slashdir
will be used.
The default behaviour is to return 404 (Not Found.)
.It Fl v Ar virtualroot
This option enables virtual hosting support.
Directories in
.Ar virtualroot
will be searched for a matching virtual host name, when parsing
the HTML request.
If a matching name is found, it will be used
as both the server's real name,
.Op Ar myname ,
and as the
.Ar slashdir .
See the
.Sx EXAMPLES
section for an example of using this option.
.It Fl X
This option enables directory indexing.
A directory index will be generated only when the default file (i.e.
.Pa index.html
normally) is not present.
.It Fl x Ar index
This option changes the default file read for directories from
.Dq index.html
to
.Ar index .
.It Fl Z Ar certificate_path privatekey_path
This option sets the path to the server certificate file and the private key file
in pem format.
It also causes
.Nm
to start SSL mode.
.El
.Pp
Note that in
.Nm
versions 20031005 and prior that supported the
.Fl C
and
.Fl M
options, they took a single space-separated argument that was parsed.
since version 20040828, they take multiple options (2 in the case of
.Fl C
and 4 in the case of
.Fl M . )
.Ss INETD CONFIGURATION
As
.Nm
uses
.Xr inetd 8
by default to process incoming TCP connections for HTTP requests
(but see the
.Fl b
option),
.Nm
has little internal networking knowledge.
(Indeed, you can run it on the command line with little change of functionality.)
A typical
.Xr inetd.conf 5
entry would be:
.Bd -literal
http stream tcp  nowait:600 _httpd /usr/libexec/httpd httpd /var/www
http stream tcp6 nowait:600 _httpd /usr/libexec/httpd httpd /var/www
.Ed
.Pp
This would serve web pages from
.Pa /var/www
on both IPv4 and IPv6 ports.
The
.Em :600
changes the
requests per minute to 600, up from the
.Xr inetd 8
default of 40.
.Pp
Using the
.Nx
.Xr inetd 8 ,
you can provide multiple IP-address based HTTP servers by having multiple
listening ports with different configurations.
.Ss NOTES
This server supports the
.Em HTTP/0.9 ,
.Em HTTP/1.0 ,
and
.Em HTTP/1.1
standards.
Support for these protocols is very minimal and many optional features are
not supported.
.Pp
.Nm
can be compiled without CGI support (NO_CGIBIN_SUPPORT), user
transformations (NO_USER_SUPPORT), directory index support (NO_DIRINDEX_SUPPORT),
daemon mode support (NO_DAEMON_MODE), and dynamic MIME content
(NO_DYNAMIC_CONTENT), and SSL support (NO_SSL_SUPPORT) by defining the listed
macros when building
.Nm .
.Ss HTTP BASIC AUTHORISATION
.Nm
has support for HTTP Basic Authorisation.
If a file named
.Pa .htpasswd
exists in the directory of the current request,
.Nm
will restrict access to documents in that directory
using the RFC 2617 HTTP
.Dq Basic
authentication scheme.
.Pp
Note:
This does not recursively protect any sub-directories.
.Pp
The
.Pa .htpasswd
file contains lines delimited with a colon containing
usernames and passwords hashed with
.Xr crypt 3 ,
for example:
.Bd -literal
heather:$1$pZWI4tH/$DzDPl63i6VvVRv2lJNV7k1
jeremy:A.xewbx2DpQ8I
.Ed
.Pp
On
.Nx ,
the
.Xr pwhash 1
utility may be used to generate hashed passwords.
.Pp
While
.Nm
distributed with
.Nx
has support for HTTP Basic Authorisation enabled by default,
in the portable distribution it is excluded.
Compile
.Nm
with
.Dq -DDO_HTPASSWD
on the compiler command line to enable this support.
It may require linking with the crypt library, using
.Dq -lcrypt .
.Ss SSL SUPPORT
.Nm
has support for SSLv2, SSLv3, and TLSv1 protocols that is included by
default.
It requires linking with the crypto and ssl library, using
.Dq -lcrypto -lssl .
To disable SSL SUPPORT compile
.Nm
with
.Dq -DNO_SSL_SUPPORT
on the compiler command line.
.Sh FILES
.Nm
looks for a couple of special files in directories that allow certain features
to be provided on a per-directory basis.
In addition to the
.Pa .htpasswd
used by HTTP basic authorisation,
if a
.Pa .bzdirect
file is found (contents are irrelevant)
.Nm
will allow direct access even with the
.Fl r
option.
If a
.Pa .bzredirect
symbolic link is found,
.Nm
will perform a smart redirect to the target of this symlink.
The target is assumed to live on the same server.
If a
.Pa .bzabsredirect
symbolic link is found,
.Nm
will redirect to the absolute url pointed to by this symlink.
This is useful to redirect to different servers.
.Sh EXAMPLES
To configure set of virtual hosts, one would use an
.Xr inetd.conf 5
entry like:
.Bd -literal
http stream tcp  nowait:600 _httpd /usr/libexec/httpd httpd -v /var/vroot /var/www
.Ed
.Pp
and inside
.Pa /var/vroot
create a directory (or a symlink to a directory) with the same name as
the virtual host, for each virtual host.
Lookups for these names are done in a case-insensitive manner.
.Pp
To use
.Nm
with PHP, one must use the
.Fl C
option to specify a CGI handler for a particular file type.
Typically this, this will be like:
.Bd -literal
httpd -C .php /usr/pkg/bin/php /var/www
.Ed
.Sh SEE ALSO
.Xr inetd.conf 5 ,
.Xr inetd 8
.Sh HISTORY
The
.Nm
program is actually called
.Dq bozohttpd .
It was first written in perl, based on another perl http server
called
.Dq tinyhttpd .
It was then rewritten from scratch in perl, and then once again in C.
From
.Dq bozohttpd
version 20060517, it has been integrated into
.Nx .
The focus has always been simplicity and security, with minimal features
and regular code audits.
This manual documents
.Nm
version 20090522.
.Sh AUTHORS
.Nm
was written by Matthew R. Green
.Aq mrg@eterna.com.au .
.Pp
The large list of contributors includes:
.Bl -dash
.It
Arnaud Lacombe
.Aq alc@netbsd.org
provided some clean up for memory leaks
.It
Christoph Badura
.Aq bad@bsd.de
provided Range: header support
.It
Julian Coleman
.Aq jdc@coris.org.uk
provided an IPv6 bugfix
.It
Chuck Cranor
.Aq chuck@research.att.com
provided cgi-bin support fixes, and more
.It
DEGROOTE Arnaud
.Aq degroote@netbsd.org
provided a fix for daemon mode
.It
Andrew Doran
.Aq ad@netbsd.org
provided directory indexing support
.It
Per Ekman
.Aq pek@pdc.kth.se
provided a fix for a minor (non-security) buffer overflow condition
.It
Jun-ichiro itojun Hagino, KAME
.Aq itojun@iijlab.net
provided initial IPv6 support
.It
Martin Husemann
.Aq martin@netbsd.org
provided .bzabsredirect support
.It
Arto Huusko
.Aq arto.huusko@pp2.inet.fi
provided fixes cgi-bin
.It
Roland Illig
.Aq roland.illig@gmx.de
provided some off-by-one fixes
.It
Zak Johnson
.Aq zakj@nox.cx
provided cgi-bin enhancements
.It
Nicolas Jombart
.Aq ecu@ipv42.net
provided fixes for HTTP basic authorisation support
.It
Thomas Klausner
.Aq wiz@danbala.ifoer.tuwien.ac.at
provided many fixes and enhancements for the man page
.It
Johnny Lam
.Aq jlam@netbsd.org
provided man page fixes
.It
Luke Mewburn
.Aq lukem@netbsd.org
provided many various fixes, including cgi-bin fixes and enhancements,
HTTP basic authorisation support and much code clean up
.It
Jeremy C. Reed
.Aq reed@netbsd.org
provided several clean up fixes, and man page updates
.It
Scott Reynolds
.Aq scottr@netbsd.org
provided various fixes
.It
Tyler Retzlaff
.Aq rtr@eterna.com.au
provided SSL support, cgi-bin fixes and much other random other stuff
.It
Steve Rumble
.Aq rumble@ephemeral.org
provided the
.Fl V
option.
.It
Joerg Sonnenberger
.Aq joerg@netbsd.org
implemented If-Modified-Since support
.It
ISIHARA Takanori
.Aq ishit@oak.dti.ne.jp
provided a man page fix
.It
Holger Weiss
.Aq holger@CIS.FU-Berlin.DE
provided http authorisation fixes
.It
.Aq xs@kittenz.org
provided chroot and change-to-user support, and other various fixes
.It
Coyote Point provided various CGI fixes
.El
.Pp
There are probably others I have forgotten (let me know if you care)
.Pp
Please send all updates to
.Nm
to
.Aq mrg@eterna.com.au
for inclusion in future releaases.
.Sh BUGS
.Nm
does not handled HTTP/1.1 chunked input from the client yet.