444 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			TeX
		
	
	
	
	
	
			
		
		
	
	
			444 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			TeX
		
	
	
	
	
	
The WiFi settings are configured in the file \texttt{/etc/config/wireless}
 | 
						|
(currently supported on Broadcom, Atheros and mac80211). When booting the router for the first time
 | 
						|
it should detect your card and create a sample configuration file. By default '\texttt{option network  lan}' is
 | 
						|
commented. This prevents unsecured sharing of the network over the wireless interface.
 | 
						|
 | 
						|
Each wireless driver has its own configuration script in \texttt{/lib/wifi/driver\_name.sh} which handles
 | 
						|
driver specific options and configurations. This script is also calling driver specific binaries like wlc for
 | 
						|
Broadcom, or hostapd and wpa\_supplicant for atheros.
 | 
						|
 | 
						|
The reason for using such architecture, is that it abstracts the driver configuration. 
 | 
						|
 | 
						|
\paragraph{Generic Broadcom wireless config:}
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device      "wl0"
 | 
						|
    option type         "broadcom"
 | 
						|
    option channel      "5"
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device       "wl0"
 | 
						|
#   option network  lan
 | 
						|
    option mode         "ap"
 | 
						|
    option ssid         "OpenWrt"
 | 
						|
    option hidden       "0"
 | 
						|
    option encryption   "none"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\paragraph{Generic Atheros wireless config:}
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device      "wifi0"
 | 
						|
    option type         "atheros"
 | 
						|
    option channel      "5"
 | 
						|
    option agmode  	"11g"
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device       "wifi0"
 | 
						|
#   option network  lan
 | 
						|
    option mode         "ap"
 | 
						|
    option ssid         "OpenWrt"
 | 
						|
    option hidden       "0"
 | 
						|
    option encryption   "none"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\paragraph{Generic mac80211 wireless config:}
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device      "wifi0"
 | 
						|
    option type         "mac80211"
 | 
						|
    option channel      "5"
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device       "wlan0"
 | 
						|
#   option network  lan
 | 
						|
    option mode         "ap"
 | 
						|
    option ssid         "OpenWrt"
 | 
						|
    option hidden       "0"
 | 
						|
    option encryption   "none"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\paragraph{Generic multi-radio Atheros wireless config:}
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device  wifi0
 | 
						|
    option type     atheros
 | 
						|
    option channel  1
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device   wifi0
 | 
						|
#   option network  lan
 | 
						|
    option mode     ap
 | 
						|
    option ssid     OpenWrt_private
 | 
						|
    option hidden   0
 | 
						|
    option encryption none
 | 
						|
 | 
						|
config wifi-device  wifi1
 | 
						|
    option type     atheros
 | 
						|
    option channel  11
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device   wifi1
 | 
						|
#   option network  lan
 | 
						|
    option mode     ap
 | 
						|
    option ssid     OpenWrt_public
 | 
						|
    option hidden   1
 | 
						|
    option encryption none
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
There are two types of config sections in this file. The '\texttt{wifi-device}' refers to
 | 
						|
the physical wifi interface and '\texttt{wifi-iface}' configures a virtual interface on top
 | 
						|
of that (if supported by the driver).
 | 
						|
 | 
						|
A full outline of the wireless configuration file with description of each field:
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device     wifi device name
 | 
						|
    option type     broadcom, atheros, mac80211
 | 
						|
    option country  us, uk, fr, de, etc.
 | 
						|
    option channel  1-14
 | 
						|
    option maxassoc 1-128 (broadcom only)
 | 
						|
    option distance 1-n
 | 
						|
    option agmode     11b, 11g, 11a, 11bg (atheros only)
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option network  the interface you want wifi to bridge with 
 | 
						|
    option device   wifi0, wifi1, wifi2, wifiN
 | 
						|
    option mode     ap, sta, adhoc, monitor, or wds
 | 
						|
    option ssid     ssid name
 | 
						|
    option bssid    bssid address
 | 
						|
    option encryption none, wep, psk, psk2, wpa, wpa2 
 | 
						|
    option key      encryption key
 | 
						|
    option key1     key 1
 | 
						|
    option key2     key 2
 | 
						|
    option key3     key 3
 | 
						|
    option key4     key 4
 | 
						|
    option server   ip address
 | 
						|
    option port     port
 | 
						|
    option hidden   0,1
 | 
						|
    option isolate  0,1
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\paragraph{Options for the \texttt{wifi-device}:}
 | 
						|
 | 
						|
\begin{itemize}
 | 
						|
    \item \texttt{type} \\
 | 
						|
        The driver to use for this interface.
 | 
						|
	
 | 
						|
    \item \texttt{country} \\
 | 
						|
        The country code used to determine the regulatory settings.
 | 
						|
 | 
						|
    \item \texttt{channel} \\
 | 
						|
        The wifi channel (e.g. 1-14, depending on your country setting).
 | 
						|
 | 
						|
    \item \texttt{maxassoc} \\
 | 
						|
        Optional: Maximum number of associated clients. This feature is supported only on the broadcom chipset.
 | 
						|
 | 
						|
    \item \texttt{distance} \\
 | 
						|
	Optional: Distance between the ap and the furthest client in meters. This feature is supported only on the atheros chipset.
 | 
						|
 | 
						|
	\item \texttt{mode} \\
 | 
						|
		The frequency band (\texttt{b}, \texttt{g}, \texttt{bg}, \texttt{a}). This feature is only supported on the atheros chipset.
 | 
						|
 | 
						|
    \item \texttt{diversity} \\
 | 
						|
	Optional: Enable diversity for the Wi-Fi device. This feature is supported only on the atheros chipset.
 | 
						|
 | 
						|
    \item \texttt{rxanteanna} \\
 | 
						|
	Optional: Antenna identifier (0, 1 or 2) for reception. This feature is supported only on the atheros chipset.
 | 
						|
 | 
						|
    \item \texttt{txanteanna} \\
 | 
						|
	Optional: Antenna identifier (0, 1 or 2) for emission. This feature is supported only on the atheros chipset.
 | 
						|
 | 
						|
\end{itemize}
 | 
						|
 | 
						|
\paragraph{Options for the \texttt{wifi-iface}:}
 | 
						|
 | 
						|
\begin{itemize}
 | 
						|
    \item \texttt{network} \\
 | 
						|
        Selects the interface section from \texttt{/etc/config/network} to be
 | 
						|
        used with this interface
 | 
						|
 | 
						|
    \item \texttt{device} \\
 | 
						|
	Set the wifi device name.
 | 
						|
 | 
						|
    \item \texttt{mode} \\
 | 
						|
        Operating mode:
 | 
						|
 | 
						|
        \begin{itemize}
 | 
						|
            \item \texttt{ap} \\
 | 
						|
                Access point mode
 | 
						|
 | 
						|
            \item \texttt{sta} \\
 | 
						|
                Client mode
 | 
						|
 | 
						|
            \item \texttt{adhoc} \\
 | 
						|
                Ad-Hoc mode
 | 
						|
 | 
						|
            \item \texttt{monitor} \\
 | 
						|
                Monitor mode
 | 
						|
 | 
						|
            \item \texttt{wds} \\
 | 
						|
                WDS point-to-point link
 | 
						|
 | 
						|
        \end{itemize}
 | 
						|
 | 
						|
    \item \texttt{ssid}
 | 
						|
	Set the SSID to be used on the wifi device.
 | 
						|
 | 
						|
    \item \texttt{bssid}
 | 
						|
	Set the BSSID address to be used for wds to set the mac address of the other wds unit.
 | 
						|
 | 
						|
    \item \texttt{encryption} \\
 | 
						|
        Encryption setting. Accepts the following values:
 | 
						|
 | 
						|
        \begin{itemize}
 | 
						|
	    \item \texttt{none}
 | 
						|
	    \item \texttt{wep}
 | 
						|
            \item \texttt{psk}, \texttt{psk2} \\
 | 
						|
                WPA(2) Pre-shared Key
 | 
						|
 | 
						|
            \item \texttt{wpa}, \texttt{wpa2} \\
 | 
						|
                WPA(2) RADIUS
 | 
						|
        \end{itemize}
 | 
						|
 | 
						|
    \item \texttt{key, key1, key2, key3, key4} (wep, wpa and psk) \\
 | 
						|
        WEP key, WPA key (PSK mode) or the RADIUS shared secret (WPA RADIUS mode)
 | 
						|
 | 
						|
    \item \texttt{server} (wpa) \\
 | 
						|
        The RADIUS server ip address
 | 
						|
 | 
						|
    \item \texttt{port} (wpa) \\
 | 
						|
        The RADIUS server port (defaults to 1812)
 | 
						|
 | 
						|
    \item \texttt{hidden} \\
 | 
						|
        0 broadcasts the ssid; 1 disables broadcasting of the ssid
 | 
						|
 | 
						|
    \item \texttt{isolate} \\
 | 
						|
        Optional: Isolation is a mode usually set on hotspots that limits the clients to communicate only with the AP and not with other wireless clients.
 | 
						|
        0 disables ap isolation (default); 1 enables ap isolation.
 | 
						|
 | 
						|
\end{itemize}
 | 
						|
 | 
						|
\paragraph{Wireless Distribution System}
 | 
						|
 | 
						|
WDS is a non-standard mode which will be working between two Broadcom devices for instance
 | 
						|
but not between a Broadcom and Atheros device.
 | 
						|
 | 
						|
\subparagraph{Unencrypted WDS connections}
 | 
						|
 | 
						|
This configuration example shows you how to setup unencrypted WDS connections.
 | 
						|
We assume that the peer configured as below as the BSSID ca:fe:ba:be:00:01
 | 
						|
and the remote WDS endpoint ca:fe:ba:be:00:02 (option bssid field).
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device      "wl0"
 | 
						|
    option type		"broadcom"
 | 
						|
    option channel      "5"
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device       "wl0"
 | 
						|
    option network  	lan
 | 
						|
    option mode         "ap"
 | 
						|
    option ssid         "OpenWrt"
 | 
						|
    option hidden       "0"
 | 
						|
    option encryption   "none"
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device       "wl0"
 | 
						|
    option network      lan
 | 
						|
    option mode         wds
 | 
						|
    option ssid         "OpenWrt WDS"
 | 
						|
    option bssid        "ca:fe:ba:be:00:02"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\subparagraph{Encrypted WDS connections}
 | 
						|
 | 
						|
It is also possible to encrypt WDS connections. \texttt{psk}, \texttt{psk2} and
 | 
						|
\texttt{psk+psk2} modes are supported. Configuration below is an example
 | 
						|
configuration using Pre-Shared-Keys with AES algorithm.
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-device  wl0
 | 
						|
    option type     broadcom
 | 
						|
    option channel  5
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device   "wl0"
 | 
						|
    option network  lan
 | 
						|
    option mode     ap
 | 
						|
    option ssid     "OpenWrt"
 | 
						|
    option encryption  psk2
 | 
						|
    option key      "<key for clients>"
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
    option device   "wl0"
 | 
						|
    option network  lan
 | 
						|
    option mode     wds
 | 
						|
    option bssid    ca:fe:ba:be:00:02
 | 
						|
    option ssid     "OpenWrt WDS"
 | 
						|
    option encryption	psk2
 | 
						|
    option key      "<psk for WDS>"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\paragraph{802.1x configurations}
 | 
						|
 | 
						|
OpenWrt supports both 802.1x client and Access Point
 | 
						|
configurations. 802.1x client is only working with
 | 
						|
Atheros or mac80211 drivers. Configuration only
 | 
						|
supports EAP types TLS, TTLS or PEAP.
 | 
						|
 | 
						|
\subparagraph{EAP-TLS}
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-iface
 | 
						|
    option device         "ath0"
 | 
						|
    option network        lan
 | 
						|
    option ssid           OpenWrt
 | 
						|
    option eap_type       tls
 | 
						|
    option ca_cert        "/etc/config/certs/ca.crt"
 | 
						|
    option priv_key       "/etc/config/certs/priv.crt"
 | 
						|
    option priv_key_pwd   "PKCS#12 passphrase"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\subparagraph{EAP-PEAP}
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
config wifi-iface
 | 
						|
    option device         "ath0"
 | 
						|
    option network        lan
 | 
						|
    option ssid           OpenWrt
 | 
						|
    option eap_type       peap
 | 
						|
    option ca_cert        "/etc/config/certs/ca.crt"
 | 
						|
    option auth           MSCHAPV2
 | 
						|
    option identity       username
 | 
						|
    option password       password
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\paragraph{Limitations:}
 | 
						|
 | 
						|
There are certain limitations when combining modes.
 | 
						|
Only the following mode combinations are supported:
 | 
						|
 | 
						|
\begin{itemize}
 | 
						|
    \item \textbf{Broadcom}: \\
 | 
						|
        \begin{itemize}
 | 
						|
            \item 1x \texttt{sta}, 0-3x \texttt{ap}
 | 
						|
            \item 1-4x \texttt{ap}
 | 
						|
            \item 1x \texttt{adhoc}
 | 
						|
            \item 1x \texttt{monitor}
 | 
						|
        \end{itemize}
 | 
						|
 | 
						|
        WDS links can only be used in pure AP mode and cannot use WEP (except when sharing the
 | 
						|
        settings with the master interface, which is done automatically).
 | 
						|
 | 
						|
    \item \textbf{Atheros}: \\
 | 
						|
        \begin{itemize}
 | 
						|
            \item 1x \texttt{sta}, 0-Nx \texttt{ap}
 | 
						|
            \item 1-Nx \texttt{ap}
 | 
						|
            \item 1x \texttt{adhoc}
 | 
						|
        \end{itemize}
 | 
						|
 | 
						|
	N is the maximum number of VAPs that the module allows, it defaults to 4, but can be
 | 
						|
	changed by loading the module with the maxvaps=N parameter.
 | 
						|
\end{itemize}
 | 
						|
 | 
						|
\paragraph{Adding a new driver configuration}
 | 
						|
 | 
						|
Since we currently only support thread different wireless drivers : Broadcom, Atheros and mac80211,
 | 
						|
you might be interested in adding support for another driver like Ralink RT2x00, 
 | 
						|
Texas Instruments ACX100/111.
 | 
						|
 | 
						|
The driver specific script should be placed in \texttt{/lib/wifi/<driver>.sh} and has to
 | 
						|
include several functions providing :
 | 
						|
 | 
						|
\begin{itemize}
 | 
						|
	\item detection of the driver presence
 | 
						|
	\item enabling/disabling the wifi interface(s)
 | 
						|
	\item configuration reading and setting
 | 
						|
	\item third-party programs calling (nas, supplicant)
 | 
						|
\end{itemize}
 | 
						|
 | 
						|
Each driver script should append the driver to a global DRIVERS variable :
 | 
						|
 | 
						|
\begin{Verbatim}
 | 
						|
append DRIVERS "driver name"
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\subparagraph{\texttt{scan\_<driver>}}
 | 
						|
 | 
						|
This function will parse the \texttt{/etc/config/wireless} and make sure there
 | 
						|
are no configuration incompatibilities, like enabling hidden SSIDS with ad-hoc mode
 | 
						|
for instance. This can be more complex if your driver supports a lof of configuration
 | 
						|
options. It does not change the state of the interface.
 | 
						|
 | 
						|
Example:
 | 
						|
\begin{Verbatim}
 | 
						|
scan_dummy() {
 | 
						|
	local device="$1"
 | 
						|
 | 
						|
	config_get vifs "$device" vifs
 | 
						|
	for vif in $vifs; do
 | 
						|
		# check config consistency for wifi-iface sections
 | 
						|
	done
 | 
						|
	# check mode combination
 | 
						|
}
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\subparagraph{\texttt{enable\_<driver>}}
 | 
						|
 | 
						|
This function will bring up the wifi device and optionally create application specific
 | 
						|
configuration files, e.g. for the WPA authenticator or supplicant.
 | 
						|
 | 
						|
Example:
 | 
						|
\begin{Verbatim}
 | 
						|
enable_dummy() {
 | 
						|
	local device="$1"
 | 
						|
 | 
						|
	config_get vifs "$device" vifs
 | 
						|
	for vif in $vifs; do
 | 
						|
		# bring up virtual interface belonging to
 | 
						|
		# the wifi-device "$device"
 | 
						|
	done
 | 
						|
}
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\subparagraph{\texttt{disable\_<driver>}}
 | 
						|
 | 
						|
This function will bring down the wifi device and all its virtual interfaces (if supported).
 | 
						|
 | 
						|
Example:
 | 
						|
\begin{Verbatim}
 | 
						|
disable_dummy() {
 | 
						|
	local device="$1"
 | 
						|
 | 
						|
	# bring down virtual interfaces belonging to
 | 
						|
	# "$device" regardless of whether they are
 | 
						|
	# configured or not. Don't rely on the vifs
 | 
						|
	# variable at this point
 | 
						|
}
 | 
						|
\end{Verbatim}
 | 
						|
 | 
						|
\subparagraph{\texttt{detect\_<driver>}}
 | 
						|
 | 
						|
This function looks for interfaces that are usable with the driver. Template config sections
 | 
						|
for new devices should be written to stdout. Must check for already existing config sections
 | 
						|
belonging to the interfaces before creating new templates.
 | 
						|
 | 
						|
Example:
 | 
						|
\begin{Verbatim}
 | 
						|
detect_dummy() {
 | 
						|
	[ wifi-device = "$(config_get dummydev type)" ] && return 0
 | 
						|
	cat <<EOF
 | 
						|
config wifi-device dummydev
 | 
						|
	option type dummy
 | 
						|
	# REMOVE THIS LINE TO ENABLE WIFI:
 | 
						|
	option disabled 1
 | 
						|
 | 
						|
config wifi-iface
 | 
						|
	option device dummydev
 | 
						|
	option mode ap
 | 
						|
	option ssid OpenWrt
 | 
						|
EOF
 | 
						|
}
 | 
						|
\end{Verbatim}
 |