.\"	$OpenBSD: httpd.conf.5,v 1.68 2015/07/19 05:17:27 reyk Exp $
.\"
.\" Copyright (c) 2014, 2015 Reyk Floeter <reyk@openbsd.org>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
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.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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.Dd $Mdocdate: July 19 2015 $
.Dt HTTPD.CONF 5
.Os
.Sh NAME
.Nm httpd.conf
.Nd HTTP daemon configuration file
.Sh DESCRIPTION
.Nm
is the configuration file for the HTTP daemon,
.Xr httpd 8 .
.Sh SECTIONS
.Nm
is divided into four main sections:
.Bl -tag -width xxxx
.It Sy Macros
User-defined variables may be defined and used later, simplifying the
configuration file.
.It Sy Global Configuration
Global settings for
.Xr httpd 8 .
.It Sy Servers
Listening HTTP web servers.
.It Sy Types
Media types and extensions.
.El
.Pp
Within the sections,
a host
.Ar address
can be specified by IPv4 address, IPv6 address, interface name,
interface group, or DNS hostname.
If the address is an interface name,
.Xr httpd 8
will look up the first IPv4 address and any other IPv4 and IPv6
addresses of the specified network interface.
If
.Sq *
is given as an address,
it will be used as an alias for
.Ar 0.0.0.0
to listen on all IPv4 addresses.
Likewise,
.Sq ::
can be used to listen on all IPv6 addresses.
A
.Ar port
can be specified by number or name.
The port name to number mappings are found in the file
.Pa /etc/services ;
see
.Xr services 5
for details.
.Pp
The current line can be extended over multiple lines using a backslash
.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
Care should be taken when commenting out multi-line text:
the comment is effective until the end of the entire block.
.Pp
Argument names not beginning with a letter, digit, or underscore
must be quoted.
.Pp
Additional configuration files can be included with the
.Ic include
keyword, for example:
.Bd -literal -offset indent
include "/etc/httpd.conf.local"
.Ed
.Sh MACROS
Macros can be defined that will later be expanded in context.
Macro names must start with a letter, digit, or underscore,
and may contain any of those characters.
Macro names may not be reserved words (for example,
.Ic directory ,
.Ic log ,
or
.Ic root ) .
Macros are not expanded inside quotes.
.Pp
For example:
.Bd -literal -offset indent
ext_ip="10.0.0.1"
server "default" {
	listen on $ext_ip port 80
}
.Ed
.Sh GLOBAL CONFIGURATION
Here are the settings that can be set globally:
.Bl -tag -width Ds
.It Ic chroot Ar directory
Set the
.Xr chroot 2
directory.
If not specified, it defaults to
.Pa /var/www ,
the home directory of the www user.
.It Ic default type Ar type/subtype
Set the default media type that is used if the media type for a
specified extension is not found in the configured types or for files
without a file extension;
see the
.Sx TYPES
section below.
If not specified, the default type is set to
.Ar application/octet-stream .
.It Ic logdir Ar directory
Specifies the full path of the directory in which log files will be written.
If not specified, it defaults to
.Pa /logs
within the
.Xr chroot 2
directory.
.It Ic prefork Ar number
Run the specified number of server processes.
This increases the performance and prevents delays when connecting
to a server.
.Xr httpd 8
runs 3 server processes by default.
.El
.Sh SERVERS
The configured web servers.
.Pp
Each
.Ic server
section starts with a declaration of the server
.Ar name :
.Bl -tag -width Ds
.It Ic server Ar name Brq ...
Match the server name using shell globbing rules.
This can be an explicit name,
.Ar www.example.com ,
or a name including wildcards,
.Ar *.example.com .
.It Ic server match Ar name Brq ...
Match the server name using pattern matching,
see
.Xr patterns 7 .
.El
.Pp
Followed by a block of options that is enclosed in curly brackets:
.Bl -tag -width Ds
.It Ic alias Ar name
Specify an additional alias
.Ar name
for this server.
.It Ic alias match Ar name
Like the
.Ic alias
option,
but
.Ic match
the
.Ar name
using pattern matching instead of shell globbing rules,
see
.Xr patterns 7 .
.It Oo Ic no Oc Ic authenticate Oo Ar realm Oc Ic with Pa htpasswd
Authenticate a remote user for
.Ar realm
by checking the credentials against the user authentication file
.Pa htpasswd .
The file name is relative to the
.Ic chroot
and must be readable by the www user.
Use the
.Ic no authenticate
directive to disable authentication in a location.
.It Ic block drop
Drop the connection without sending an error page.
.It Ic block Op Ic return Ar code Op Ar uri
Close the connection and send an error page.
If the optional return code is not specified,
.Xr httpd 8
denies access with a
.Sq 403 Forbidden
response.
The optional
.Ar uri
argument can be used with return codes in the 3xx range to send a
.Sq Location:
header for redirection to a specified URI.
.Pp
The
.Ar uri
may contain predefined macros that will be expanded at runtime:
.Pp
.Bl -tag -width $DOCUMENT_URI -offset indent -compact
.It Ic $DOCUMENT_URI
The request path.
.It Ic $QUERY_STRING
The optional query string of the request.
.It Ic $REMOTE_ADDR
The IP address of the connected client.
.It Ic $REMOTE_PORT
The TCP source port of the connected client.
.It Ic $REMOTE_USER
The remote user for HTTP authentication.
.It Ic $REQUEST_URI
The request path and optional query string.
.It Ic $SERVER_ADDR
The configured IP address of the server.
.It Ic $SERVER_PORT
The configured TCP server port of the server.
.It Ic $SERVER_NAME
The name of the server.
.It Pf % Ar n
The capture index
.Ar n
of a string that was captured by the enclosing
.Ic location match
option.
.El
.It Ic connection Ar option
Set the specified options and limits for HTTP connections.
Valid options are:
.Bl -tag -width Ds
.It Ic max request body Ar number
Set the maximum body size in bytes that the client can send to the server.
The default value is 1048576 bytes (1M).
.It Ic max requests Ar number
Set the maximum number of requests per persistent HTTP connection.
Persistent connections are negotiated using the Keep-Alive header in
HTTP/1.0 and enabled by default in HTTP/1.1.
The default maximum number of requests per connection is 100.
.It Ic timeout Ar seconds
Specify the inactivity timeout in seconds for accepted sessions.
The default timeout is 600 seconds (10 minutes).
The maximum is 2147483647 seconds (68 years).
.El
.It Ic default type Ar type/subtype
Set the default media type for the specified location,
overwriting the global setting.
.It Ic directory Ar option
Set the specified options when serving or accessing directories.
Valid options are:
.Bl -tag -width Ds
.It Oo Ic no Oc Ic auto index
If no index file is found, automatically generate a directory listing.
This is disabled by default.
.It Ic index Ar string
Set the directory index file.
If not specified, it defaults to
.Pa index.html .
.It Ic no index
Disable the directory index.
.Xr httpd 8
will neither display nor generate a directory index.
.El
.It Oo Ic no Oc Ic fastcgi Op Ic socket Ar socket
Enable FastCGI instead of serving files.
The
.Ar socket
is a local path name within the
.Xr chroot 2
root directory of
.Xr httpd 8
and defaults to
.Pa /run/slowcgi.sock .
.It Ic hsts Oo Ar option Oc
Enable HTTP Strict Transport Security.
Valid options are:
.Bl -tag -width Ds
.It Ic max-age Ar seconds
Set the maximum time in seconds a receiving user agent should regard
this host as an HSTS host.
The default is one year.
.It Ic preload
Confirm and authenticate that the site is permitted to be included in
a browser's preload list.
.It Ic subdomains
Signal to the receiving user agent that this host and all sub domains
of the host's domain should be considered HSTS hosts.
.El
.It Ic listen on Ar address Oo Ic tls Oc Ic port Ar number
Set the listen address and port.
This statement can be specified multiple times.
.It Ic location Ar path Brq ...
Specify server configuration rules for a specific location.
The
.Ar path
argument will be matched against the request path with shell globbing rules.
A location section may include most of the server configuration rules
except
.Ic connection ,
.Ic listen on ,
.Ic location
and
.Ic tcp .
.It Ic location match Ar path Brq ...
Like the
.Ic location
option,
but
.Ic match
the
.Ar path
using pattern matching instead of shell globbing rules,
see
.Xr patterns 7 .
The pattern may contain captures that can be used in the
.Ar uri
of an enclosed
.Ic block return
option.
.It Oo Ic no Oc Ic log Op Ar option
Set the specified logging options.
Logging is enabled by default using the standard
.Ic access
and
.Ic error
log files,
but can be changed per server or location.
Use the
.Ic no log
directive to disable logging of any requests.
Valid options are:
.Bl -tag -width Ds
.It Ic access Ar name
Set the
.Ar name
of the access log file relative to the log directory.
If not specified, it defaults to
.Pa access.log .
.It Ic error Ar name
Set the
.Ar name
of the error log file relative to the log directory.
If not specified, it defaults to
.Pa error.log .
.It Ic style Ar style
Set the logging style.
The
.Ar style
can be
.Cm common ,
.Cm combined
or
.Cm connection .
The styles
.Cm common
and
.Cm combined
write a log entry after each request similar to the standard Apache
and nginx access log formats.
The style
.Cm connection
writes a summarized log entry after each connection,
that can have multiple requests,
similar to the format that is used by
.Xr relayd 8 .
If not specified, the default is
.Cm common .
.It Oo Ic no Oc Ic syslog
Enable or disable logging to
.Xr syslog 3
instead of the log files.
.El
.It Ic pass
Disable any previous
.Ic block
in a location.
.It Ic root Ar option
Configure the document root and options for the request path.
Valid options are:
.Bl -tag -width Ds
.It Ar directory
Set the document root of the server.
The
.Ar directory
is a pathname within the
.Xr chroot 2
root directory of
.Nm httpd .
If not specified, it defaults to
.Pa /htdocs .
.It Ic strip Ar number
Strip
.Ar number
path components from the beginning of the request path before looking
up the stripped-down path at the document root.
.El
.It Ic tcp Ar option
Enable or disable the specified TCP/IP options; see
.Xr tcp 4
and
.Xr ip 4
for more information about the options.
Valid options are:
.Bl -tag -width Ds
.It Ic backlog Ar number
Set the maximum length the queue of pending connections may grow to.
The backlog option is 10 by default and is limited by the
.Va kern.somaxconn
.Xr sysctl 8
variable.
.It Ic ip minttl Ar number
This option for the underlying IP connection may be used to discard packets
with a TTL lower than the specified value.
This can be used to implement the
Generalized TTL Security Mechanism (GTSM)
according to RFC 5082.
.It Ic ip ttl Ar number
Change the default time-to-live value in the IP headers.
.It Oo Ic no Oc Ic nodelay
Enable the TCP NODELAY option for this connection.
This is recommended to avoid delays in the data stream.
.It Oo Ic no Oc Ic sack
Use selective acknowledgements for this connection.
.It Ic socket buffer Ar number
Set the socket-level buffer size for input and output for this
connection.
This will affect the TCP window size.
.El
.It Ic tls Ar option
Set the TLS configuration for the server.
These options are only used if TLS has been enabled via the listen directive.
Valid options are:
.Bl -tag -width Ds
.It Ic certificate Ar file
Specify the certificate to use for this server.
The
.Ar file
should contain a PEM encoded certificate.
The default is
.Pa /etc/ssl/server.crt .
.It Ic ciphers Ar string
Specify the TLS cipher string.
If not specified, the default value
.Qq HIGH:!aNULL
will be used (strong crypto cipher suites without anonymous DH).
See the CIPHERS section of
.Xr openssl 1
for information about SSL/TLS cipher suites and preference lists.
.It Ic dhe Ar params
Specify the DHE parameters to use for DHE cipher suites.
Valid parameter values are none, legacy and auto.
For legacy a fixed key length of 1024 bits is used, whereas for auto the key
length is determined automatically.
The default is none, which disables DHE cipher suites.
.It Ic ecdhe Ar curve
Specify the ECDHE curve to use for ECDHE cipher suites.
Valid parameter values are none, auto and the short name of any known curve.
The default is auto.
.It Ic key Ar file
Specify the private key to use for this server.
The
.Ar file
should contain a PEM encoded private key and reside outside of the
.Xr chroot 2
root directory of
.Nm httpd .
The default is
.Pa /etc/ssl/private/server.key .
.It Ic protocols Ar string
Specify the TLS protocols to enable for this server.
If not specified, the value
.Qq default
will be used (secure protocols; TLSv1.2-only).
Refer to the
.Xr tls_config_parse_protocols 3
function for other valid protocol string values.
.El
.El
.Sh TYPES
Configure the supported media types.
.Xr httpd 8
will set the
.Ar Content-Type
of the response header based on the file extension listed in the
.Ic types
section.
If not specified,
.Xr httpd 8
will use built-in media types for
.Ar text/css ,
.Ar text/html ,
.Ar text/plain ,
.Ar image/gif ,
.Ar image/png ,
.Ar image/jpeg ,
and
.Ar application/javascript .
.Pp
The
.Ic types
section must include one or more lines of the following syntax:
.Bl -tag -width Ds
.It Ar type/subtype Ar name Op Ar name ...
Set the media
.Ar type
and
.Ar subtype
to the specified extension
.Ar name .
One or more names can be specified per line.
Each line may end with an optional semicolon.
.It Ic include Ar file
Include types definitions from an external file, for example
.Pa /usr/share/misc/mime.types .
.El
.Sh EXAMPLES
The following example will start one server that is pre-forked two
times and is listening on all local IP addresses.
It additionally defines some media types overriding the defaults.
.Bd -literal -offset indent
prefork 2

server "default" {
	listen on * port 80
}

types {
	text/css		css
	text/html		html htm
	text/txt		txt
	image/gif		gif
	image/jpeg		jpeg jpg
	image/png		png
	application/javascript	js
	application/xml		xml
}
.Ed
.Pp
The server can also be configured to only listen on the primary IP
address of the network interface that is a member of the
.Qq egress
group.
.Bd -literal -offset indent
server "default" {
	listen on egress port 80
}
.Ed
.Pp
Multiple servers can be configured to support hosting of different domains.
If the same address is repeated multiple times in the
.Ic listen on
statement,
the server will be matched based on the requested host name.
.Bd -literal -offset indent
server "www.example.com" {
	alias "example.com"
	listen on * port 80
	listen on * tls port 443
	root "/htdocs/www.example.com"
}

server "www.a.example.com" {
	listen on 203.0.113.1 port 80
	root "/htdocs/www.a.example.com"
}

server "www.b.example.com" {
	listen on 203.0.113.1 port 80
	root "/htdocs/www.b.example.com"
}

server "intranet.example.com" {
	listen on 10.0.0.1 port 80
	root "/htdocs/intranet.example.com"
}
.Ed
.Pp
Simple redirections can be configured with the
.Ic block
directive:
.Bd -literal -offset indent
server "example.com" {
	listen on 10.0.0.1 port 80
	block return 301 "http://www.example.com/"
}

server "www.example.com" {
	listen on 10.0.0.1 port 80
}
.Ed
.Sh SEE ALSO
.Xr htpasswd 1 ,
.Xr patterns 7 ,
.Xr httpd 8 ,
.Xr slowcgi 8
.Sh AUTHORS
.An -nosplit
The
.Xr httpd 8
program was written by
.An Reyk Floeter Aq Mt reyk@openbsd.org .