.\" $OpenBSD: hostapd.conf.5,v 1.5 2005/06/17 20:17:01 jmc Exp $
.\"
.\" Copyright (c) 2004, 2005 Reyk Floeter <reyk@vantronix.net>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd April 13, 2004
.Dt HOSTAPD.CONF 5
.Os
.Sh NAME
.Nm hostapd.conf
.Nd configuration file for the Host Access Point daemon
.Sh DESCRIPTION
.Nm
is the configuration file for the
.Xr hostapd 8
daemon.
.Sh SECTIONS
The
.Nm
file is divided into two main sections.
.Bl -tag -width xxxx
.It Sy Macros
User-defined variables may be defined and used later, simplifying the
configuration file.
.It Sy Tables
Tables provide a mechanism to handle a large number of link layer
addresses easily, with increased performance and flexibility.
.It Sy Global Configuration
Global runtime settings for
.Xr hostapd 8 .
.It Sy Event rules
Event rules provide a powerful mechanism to trigger certain actions
when receiving specified IEEE 802.11 frames.
.El
.Pp
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
.Sh MACROS
Much like
.Xr cpp 1
or
.Xr m4 1 ,
macros can be defined that will later be expanded in context.
Macro names must start with a letter, and may contain letters, digits
and underscores.
Macro names may not be reserved words (for example,
.Ic set ,
.Ic interface ,
or
.Ic hostap ) .
Macros are not expanded inside quotes.
.Pp
For example:
.Bd -literal -offset indent
wlan="ath0"
set iapp interface $wlan
.Ed
.Sh TABLES
Tables are named structures which can hold a collection of link layer
addresses, masked address ranges, and link layer to IP address
assignments.
Lookups against tables in
.Xr hostapd 8
are relatively fast, making a single rule with tables much more
efficient, in terms of processor usage and memory consumption, than a
large number of rules which differ only in link layer addresses.
.Pp
Tables are used for
.Xr hostapd 8
.Ic event rules
to match specified IEEE 802.11 link layer addresses and address ranges
and the capability to assign link layer to IP addresses is a
requirement for advanced IAPP functionality.
.Pp
For example:
.Bd -literal -offset indent
cisco="00:40:06:ff:ff:ff / ff:ff:ff:00:00:00"

table <black> { $cisco, 00:0d:60:ff:f1:2a }
table <myess> const {
	00:00:24:c3:40:18 -> 10.195.64.24,
	00:00:24:c3:40:19 -> 10.195.64.25,
	00:00:24:c3:40:1a -> 10.195.64.26
}
.Ed
.Sh GLOBAL CONFIGURATION
The following configuration settings are understood:
.Bl -tag -width xxxx
.It Ic set hostap interface Ar interface
Specify the wireless interface running in Host AP mode.
This option could be omitted to use
.Xr hostapd 8
to log received IAPP messages.
.It Ic set iapp interface Ar interface
Specify the mandatory Inter-Access-Point (IAPP) interface.
.It Ic set iapp mode Ar mode
Specify the IAPP mode, if not using the default one.
IAPP could be used in multicast (default) or in broadcast mode.
The used multicast group is 224.0.1.178.
.Pp
Possible options:
.Bd -unfilled -offset indent
.Ic set iapp mode multicast
.Ic set iapp mode broadcast
.Ed
.El
.Sh EVENT RULES
Event rules provide a powerful way to trigger a certain action when
receiving specified IEEE 802.11 frames on the
.Ic hostap interface .
The rules are handled in sequential order, from first to last.
.Pp
In difference to packet filter rules like in
.Xr pf.conf 5 ,
the
.Xr hostapd 8
event rules are handled without a state,
each rule is processed indepedently from the others and from
any previous actions.
.Pp
All hostapd event rules are single line statements beginning with
the mandatory
.Ic hostap handle
keywords and optional rule options, frame matching,
a specified action and a limit:
.Bd -literal -offset indent
hostap handle [<option>] [<frame>] [<action>] [<limit>]
.Ed
.Pp
The optional parts are defined below:
.Bl -tag -width xxxx
.It Aq Ic option
The rule
.Ic option
will modify the behaviour of handling the statement.
There are two possible options,
.Ic quick
and
.Ic skip .
If either the keyword
.Ic quick
or the keyword
.Ic skip
is specified, no further event rules will be handled for this frame
after processing this rule successfully.
The keyword
.Ic skip
additionally skips any further IAPP processing of the frame,
which is normally done after handling the event rules.
.It Xo
.Ic frame
.Bq Aq Ar type
.Bq Aq Ar subtype
.Bq Aq Ar dir
.Bq Aq Ar from
.Bq Aq Ar to
.Bq Aq Ar bssid
.Xc
The
.Ic frame
description specifies a mechanism to match IEEE 802.11 frames.
.It Ic with Aq Ar action
An optional
.Ar action
is triggered if a received IEEE 802.11 frame matches the frame
description.
The following choices are available as an
.Ar action :
.Bd -literal
frame <type> <subtype> [<dir>] <from> <to> <bssid>
.Ed
.Bd -unfilled -offset indent
.Ic type :
type data
type management
.Ed
.Bd -unfilled -offset indent
.Ic subtype :
subtype beacon
subtype deauth [<reason>]
subtype assoc request
subtype assoc resp
subtype atim
subtype auth
subtype probe request
subtype probe resp
subtype reassoc request
subtype reassoc response
.Ed
.Bd -unfilled -offset indent
.Ic reason :
reason assoc leave
reason assoc not authed
reason assoc toomany
reason auth expire
reason auth leave
reason ie invalid
reason mic failure
reason not authed
reason not assoced
reason rsn required
reason rsn inconsistent
reason unspecified
.Ed
.Bd -unfilled -offset indent
.Ic dir :
dir no ds
dir to ds
dir from ds
dir ds to ds
.Ed
.Bd -unfilled -offset indent
.Ic from/to/bssid :
( from | to | bssid ) lladdr
( from | to | bssid ) &refaddr
.Ed
.Bd -unfilled
iapp radiotap
log [verbose]
node ( add | delete ) <lladdr>
resend
.Ed
.It Xo
.Ic limit
.Aq Ar number
.Pq Ar sec \*(Ba usec
.Xc
It is possible to
.Ic limit
handling of specific rules.
In some cases it is absolutely necessary to use limited matching
to protect
.Xr hostapd 8
against excessive flooding with IEEE 802.11 frames.
For example, beacon frames will be normally received every 100 ms.
.Pp
.El
.Sh GRAMMAR
Syntax for
.Nm
in BNF:
.Bd -literal
grammar		= [ varset ] | [ tabledef ] | option | [ event ]

varset		= varname "=" varvalue

tabledef	= "table" table tableopts

table		= "<" tablename ">"

tableopts	= "const" | "{" [ "\n" ] "}" |
		  "{" [ "\\n" ] tableaddrlist [ "\\n" ] "}"

tableaddrlist	= lladdr [ "->" ipv4-dotted-quad | "&" lladdr-mask |
		  "/" number ] [ "," ] [ tableaddrlist ]

option		= "set" ( "hostap" "interface" name |
		  "iapp" "interface" name [ "passive" ] |
		  [ "iapp" "mode" ( "multicast" | "broadcast" ] )

event		= "hostap" "handle" [ eventopt ] [ frmmatch ] [ action ]
		  [ limit ]

eventopt	= "skip" | "quick"

action		= "with" ( "log" [ "verbose" ] | "frame" frmaction |
		  "iapp" "type" "radiotap" |
		  "node" ( "add" | "delete" ) frmactionaddr )

frmmatch	= [ frmmatchtype ] [ "dir" ( "any" | [ "!" ] frmdir ) ]
		  [ ( "from" | "to" | "bssid" ) frmmatchaddr ]

frmmatchtype	= "type" ( "any" | [ "!" ] ( "data" | "management"
		  [ frmmatchmgmt ] ) )

frmmatchmgmt	= "subtype" ( "any" | [ "!" ] frmsubtype )

frmmatchaddr	= "any" | [ "!" ] table | [ "!" ] lladdr

frmaction	= frmactiontype [ "dir" frmdir ]
		  ( "from" , "to" , "bssid" ) frmactionaddr

frmactiontype	= "type" ( "data" | "management" "subtype" frmsubtype )

frmactionaddr	= lladdr | refaddr

limit		= "limit" number ( "sec" | "usec" )

frmsubtype	= ( "probe-request" | "probe-resp" |
		  "beacon" ) [ frmelems ] | "atim" | "auth" | "deauth" |
		  "assoc-request" | "assoc-resp" | "reassoc-request" |
		  "reassoc-response"

frmelems	= "nwid" [ "!" ] name [ frmelems ]

frmdir		= ( "no" | "to" | "from" | "ds" "to" ) "ds"

refaddr		= "&" ( "from" | "to" | "bssid" )
.Ed
.Sh FILES
.Bl -tag -width "/etc/hostapd.conf" -compact
.It Pa /etc/hostapd.conf
Default location of the configuration file.
.El
.Sh SEE ALSO
.Xr hostapd 8
.Sh AUTHORS
The
.Xr hostapd 8
program was written by
.An Reyk Floeter Aq reyk@openbsd.org .