X-Git-Url: https://git.rohieb.name/openwrt.git/blobdiff_plain/8fb079219b9d59341d27e18aefcb306693b7b66c..572de1e5c43668941bcb22f62a56725b8dfbd35b:/docs/wireless.tex diff --git a/docs/wireless.tex b/docs/wireless.tex index 6b3ffbac7..7e9623972 100644 --- a/docs/wireless.tex +++ b/docs/wireless.tex @@ -1,8 +1,15 @@ 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" @@ -11,41 +18,97 @@ 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. @@ -53,13 +116,27 @@ of that (if supported by the driver). 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: @@ -78,35 +155,47 @@ of that (if supported by the driver). \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} @@ -117,7 +206,7 @@ Only the following mode combinations are supported: \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}: \\ @@ -126,7 +215,104 @@ Only the following mode combinations are supported: \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/.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\_}} + +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\_}} + +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\_}} + +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\_}} + +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 <