HTTPD(8)

HTTPD(8) | NetBSD System Manager's Manual | HTTPD(8)

# NAME

httpd — hyper text transfer protocol version 1.1 daemon

# SYNOPSIS

httpd | [-CIMPSZciptvx] [-C suffix cgihandler] [-I port] [-M suffix type encoding encoding11] [-P pidfile] [-S server_software] [-Z cert privkey] [-c cgibin] [-i address] [-p pubdir] [-t chrootdir] [-v virtualroot] [-x index] slashdir [myname]

# DESCRIPTION

The httpd program reads a 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 slashdir directory. The server uses myname as its name, which defaults to the local hostname, obtained from gethostname(3) (but see the -v option for virtual hosting.) httpd writes logs to syslog(3) using the ftp facility (but see the -s option for testing.) httpd is designed to be small, simple and relatively featureless, hopefully increasing its security.

## OPTIONS

The following options are available:

-b
  Enables daemon mode, where httpd detaches from the current terminal, running in the background and servicing HTTP requests.
-C suffix cgihandler
  Adds a new CGI handler program for a particular file type. The suffix should be any normal file suffix, and the 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 -C options may be passed.
-c cgibin
  Enables the CGI/1.1 interface. The cgibin directory is expected to contain the CGI programs to be used. httpd looks for URL's in the form of /cgi-bin/<scriptname> where <scriptname> is a valid CGI program in the cgibin directory. In other words, all CGI URL's must begin with /cgi-bin/. Note that the CGI/1.1 interface is not available with ~user translation.
-e
  Causes httpd to not clear the environment when used with either the -t or -U options.
-f
  Stops the -b flag from httpd detaching from the tty and going into the background.
-H
  Causes directory index mode to hide files and directories that start with a period, except for ... Also see -X.
-I port
  Causes httpd to use port instead of the default “http” port. When used with the -b option, it changes the bound port. Otherwise it forces redirections to use this port instead of the value obtained via getsockname(2).
-i address
  Causes address to use used as the address to bind daemon mode. If otherwise unspecified, the address used to bind is derived from the myname, which defaults to the name returned by gethostname(3). Only the last -i option is used. This option is only valid with the -b option.
-M suffix type encoding encoding11
  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 “Content-Type”, “Content-Encoding”, and “Content-Encoding” for HTTP/1.1 connections, respectively. If any of these are a single dash (“-”), the empty string is used instead. Multiple -M options may be passed.
-n
  Stops httpd from doing IP address to name resolution of hosts for setting the REMOTE_HOST variable before running a CGI program. This option has no effect without the -c option.
-P pidfile
  Causes httpd to create a pid file in pidfile when run in daemon mode with the -b option.
-p pubdir
  Changes the default user directory for /~user/ translations from “public_html” to pubdir.
-r
  Forces pages besides the “index.html” (see the -X option) page to require that the Referrer: header be present and refer to this web server, otherwise a redirect to the “index.html” page will be returned instead.
-S server_software
  Sets the internal server version to server_software.
-s
  Forces logging to be set to stderr always.
-t chrootdir
  Makes httpd 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 -e option is also used.
-U username
  Causes httpd to switch to the user and the groups of username after initialization. This option, like -t above, causes httpd to clear the environment unless the -e option is given.
-u
  Enables the transformation of Uniform Resource Locators of the form /~user/ into the directory ~user/public_html (but see the -p option above).
-V
  Sets the default virtual host directory to slashdir. If no directory exists in virtualroot for the request, then slashdir will be used. The default behaviour is to return 404 (Not Found.)
-v virtualroot
  Enables virtual hosting support. Directories in 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, [myname], and as the slashdir. See the EXAMPLES section for an example of using this option.
-X
  Enables directory indexing. A directory index will be generated only when the default file (i.e. index.html normally) is not present.
-x index
  Changes the default file read for directories from “index.html” to index.
-Z certificate_path privatekey_path
  Sets the path to the server certificate file and the private key file in pem format. It also causes httpd to start SSL mode.

Note that in httpd versions 20031005 and prior that supported the -C and -M options, they took a single space-separated argument that was parsed. since version 20040828, they take multiple options (2 in the case of -C and 4 in the case of -M.)

## INETD CONFIGURATION

As httpd uses inetd(8) by default to process incoming TCP connections for HTTP requests (but see the -b option), httpd has little internal networking knowledge. (Indeed, you can run it on the command line with little change of functionality.) A typical inetd.conf(5) entry would be:

    http stream tcp  nowait:600 _httpd /usr/libexec/httpd httpd /var/www
    http stream tcp6 nowait:600 _httpd /usr/libexec/httpd httpd /var/www

This would serve web pages from /var/www on both IPv4 and IPv6 ports. The :600 changes the requests per minute to 600, up from the inetd(8) default of 40.

Using the NetBSD inetd(8), you can provide multiple IP-address based HTTP servers by having multiple listening ports with different configurations.

## NOTES

This server supports the HTTP/0.9, HTTP/1.0, and HTTP/1.1 standards. Support for these protocols is very minimal and many optional features are not supported.

httpd 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 httpd.

## HTTP BASIC AUTHORISATION

httpd has support for HTTP Basic Authorisation. If a file named .htpasswd exists in the directory of the current request, httpd will restrict access to documents in that directory using the RFC 2617 HTTP “Basic” authentication scheme.

Note: This does not recursively protect any sub-directories.

The .htpasswd file contains lines delimited with a colon containing usernames and passwords hashed with crypt(3), for example:

    heather:$1$pZWI4tH/$DzDPl63i6VvVRv2lJNV7k1
    jeremy:A.xewbx2DpQ8I

On NetBSD, the pwhash(1) utility may be used to generate hashed passwords.

While httpd distributed with NetBSD has support for HTTP Basic Authorisation enabled by default, in the portable distribution it is excluded. Compile httpd with “-DDO_HTPASSWD” on the compiler command line to enable this support. It may require linking with the crypt library, using “-lcrypt”.

## SSL SUPPORT

httpd has support for SSLv2, SSLv3, and TLSv1 protocols that is included by default. It requires linking with the crypto and ssl library, using “-lcrypto -lssl”. To disable SSL SUPPORT compile httpd with “-DNO_SSL_SUPPORT” on the compiler command line.

# FILES

httpd 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 .htpasswd used by HTTP basic authorisation, if a .bzdirect file is found (contents are irrelevant) httpd will allow direct access even with the -r option. If a .bzredirect symbolic link is found, httpd will perform a smart redirect to the target of this symlink. The target is assumed to live on the same server. If a .bzabsredirect symbolic link is found, httpd will redirect to the absolute url pointed to by this symlink. This is useful to redirect to different servers.

# EXAMPLES

To configure set of virtual hosts, one would use an inetd.conf(5) entry like:

    http stream tcp  nowait:600 _httpd /usr/libexec/httpd httpd -v /var/vroot /var/www

and inside /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.

To use httpd with PHP, one must use the -C option to specify a CGI handler for a particular file type. Typically this will be like:

    httpd -C .php /usr/pkg/bin/php /var/www

# SEE ALSO

inetd.conf(5), inetd(8)

# HISTORY

The httpd program is actually called “bozohttpd”. It was first written in perl, based on another perl http server called “tinyhttpd”. It was then rewritten from scratch in perl, and then once again in C. From “bozohttpd” version 20060517, it has been integrated into NetBSD. The focus has always been simplicity and security, with minimal features and regular code audits. This manual documents httpd version 20100920.

# AUTHORS

httpd was written by Matthew R. Green <mrg@eterna.com.au>.

The large list of contributors includes:

- Arnaud Lacombe <alc@netbsd.org> provided some clean up for memory leaks
- Christoph Badura <bad@bsd.de> provided Range: header support
- Sean Boudreau <seanb@NetBSD.org> provided a security fix for virtual hosting
- Julian Coleman <jdc@coris.org.uk> provided an IPv6 bugfix
- Chuck Cranor <chuck@research.att.com> provided cgi-bin support fixes, and more
- DEGROOTE Arnaud <degroote@netbsd.org> provided a fix for daemon mode
- Andrew Doran <ad@netbsd.org> provided directory indexing support
- Per Ekman <pek@pdc.kth.se> provided a fix for a minor (non-security) buffer overflow condition
- Alistair G. Crooks <agc@netbsd.org> cleaned up many internal interfaces, made bozohttpd linkable as a library and provided the lua binding.
- Jun-ichiro itojun Hagino, KAME <itojun@iijlab.net> provided initial IPv6 support
- Martin Husemann <martin@netbsd.org> provided .bzabsredirect support
- Arto Huusko <arto.huusko@pp2.inet.fi> provided fixes cgi-bin
- Roland Illig <roland.illig@gmx.de> provided some off-by-one fixes
- Zak Johnson <zakj@nox.cx> provided cgi-bin enhancements
- Nicolas Jombart <ecu@ipv42.net> provided fixes for HTTP basic authorisation support
- Thomas Klausner <wiz@danbala.ifoer.tuwien.ac.at> provided many fixes and enhancements for the man page
- Johnny Lam <jlam@netbsd.org> provided man page fixes
- Luke Mewburn <lukem@netbsd.org> provided many various fixes, including cgi-bin fixes and enhancements, HTTP basic authorisation support and much code clean up
- Jeremy C. Reed <reed@netbsd.org> provided several clean up fixes, and man page updates
- Scott Reynolds <scottr@netbsd.org> provided various fixes
- Tyler Retzlaff <rtr@eterna.com.au> provided SSL support, cgi-bin fixes and much other random other stuff
- rudolf <netbsd@eq.cz> provided minor compile fixes and a CGI content map fix
- Steve Rumble <rumble@ephemeral.org> provided the -V option.
- Joerg Sonnenberger <joerg@netbsd.org> implemented If-Modified-Since support
- ISIHARA Takanori <ishit@oak.dti.ne.jp> provided a man page fix
- Holger Weiss <holger@CIS.FU-Berlin.DE> provided http authorisation fixes
- <xs@kittenz.org> provided chroot and change-to-user support, and other various fixes
- Coyote Point provided various CGI fixes
- Julio Merino added pidfile support and provided some man page fixes

There are probably others I have forgotten (let me know if you care)

Please send all updates to httpd to <mrg@eterna.com.au> for inclusion in future releaases.

# BUGS

httpd does not handle HTTP/1.1 chunked input from the client yet.

November 17, 2011 | NetBSD 5.99