libs/sys: implement luci.sys.wifi.channels()

[project/luci.git] / libs / sys / luasrc / sys.lua

diff --git a/libs/sys/luasrc/sys.lua b/libs/sys/luasrc/sys.lua
index 1ecd5d2..3412b32 100644 (file)
--- a/libs/sys/luasrc/sys.lua
+++ b/libs/sys/luasrc/sys.lua
@@ -681,6 +681,36 @@ function wifi.iwscan(iface)
        return iface and (iws[iface] or {}) or iws
 end
 
+--- Get available channels from given wireless iface.
+-- @param iface        Wireless interface (optional)
+-- @return             Table of available channels
+function wifi.channels(iface)
+       local cmd = "iwlist " .. ( iface or "" ) .. " freq 2>/dev/null"
+       local cns = { }
+
+       local fd = io.popen(cmd)
+       if fd then
+               local ln, c, f
+               repeat
+                       ln = fd:read("*l") or ""
+                       c, f = ln:match("Channel (%d+) : (%d+%.%d+) GHz")
+                       if c and f then
+                               cns[tonumber(c)] = tonumber(f)
+                       end
+               until not ( #ln > 0 )
+               fd:close()
+       end
+
+       if #cns == 0 then
+               cms = {
+                       2.412, 2.417, 2.422, 2.427, 2.432, 2.437,
+                       2.442, 2.447, 2.452, 2.457, 2.462
+               }
+       end
+
+       return cns
+end
+
 
 --- LuCI system utilities / init related functions.
 -- @class      module