The WiFi settings are configured in the file \texttt{/etc/config/wireless}
(currently supported on Broadcom and Atheros). When booting the router for the first time
-it should detect your card and create a sample configuration that looks like this:
+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.
-\paragraph{Sample Broadcom wireless config:}
+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"
config wifi-iface
option device "wl0"
+# option network lan
option mode "ap"
option ssid "OpenWrt"
option hidden "0"
option encryption "none"
\end{Verbatim}
-\paragraph{Sample Atheros wireless config:}
+\paragraph{Generic Atheros wireless config:}
\begin{Verbatim}
config wifi-device "wifi0"
option type "atheros"
option channel "5"
- option mode "11g"
+ 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 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
+ 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, 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{mode} \\
- The frequency band (\texttt{b}, \texttt{g}, \texttt{bg}, \texttt{a})
-
\item \texttt{country} \\
The country code used to determine the regulatory settings.
The wifi channel (e.g. 1-14, depending on your country setting).
\item \texttt{maxassoc} \\
- Maximum number of associated clients
+ 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.
+
\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:
\end{itemize}
- \item \texttt{network} \\
- Selects the interface section from \texttt{/etc/config/network} to be
- used with this interface
+ \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} (wpa and psk) \\
- Either the WPA key (PSK mode) or the RADIUS shared secret (WPA RADIUS mode)
+ \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 address
+ The RADIUS server ip address
\item \texttt{port} (wpa) \\
The RADIUS server port
+ \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{Limitations:}
+There are certain limitations when combining modes.
Only the following mode combinations are supported:
\begin{itemize}
\item 1x \texttt{adhoc}
\end{itemize}
- WDS links can only be used in pure AP mode and can't use WEP (except when sharing the
+ 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}: \\
\item 1-4x \texttt{ap}
\item 1x \texttt{adhoc}
\end{itemize}
+\end{itemize}
+\paragraph{Adding a new driver configuration}
+
+Since we currently only support two different wireless drivers : Broadcom and Atheros,
+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}