feature: added a wifi scan endpoint to the /api (#379)

* wscan can output results as json

* added a page for displaying scan results as json

* updated file permissions with +x

* added endpoint for wifi scan

* Revert "updated file permissions with +x"

This reverts commit 6f0a038334fbacc3f585f0a86fb7d9986a47b7d2.

* Revert "added a page for displaying scan results as json"

This reverts commit 4806ad01b6b717e2e02f248309a0257bb390af23.

* Revert "wscan can output results as json"

This reverts commit 75454e7e790a0457a0846182b0a8a44205772368.

* removed hardcoded device name

* exposed freqlist through the api

files/www/cgi-bin/api

@@ -41,6 +41,7 @@ require("aredn.http")
 local aredn_info = require("aredn.info")
 require("nixio")
 local json = require("luci.jsonc")
+require("iwinfo")
 
 -- Function extensions
 os.capture = capture
@@ -125,6 +126,17 @@ function getFreeMemory()
 	return info
 end
 
+function getScanList()
+	local device = aredn_info.getMeshRadioDevice()
+	local scanlist = iwinfo["nl80211"].scanlist(device)
+	return scanlist
+end
+
+function getFreqList()
+	local device = aredn_info.getMeshRadioDevice()
+	local freqlist = iwinfo["nl80211"].freqlist(device)
+	return freqlist
+end
 
 -- ==== MAIN =====
 ctx = uci.cursor()
@@ -175,6 +187,8 @@ for page, comps in pairs(qsset) do
 				info['pages'][page][comp]=aredn_info.getOLSRInfo()
 			elseif comp=="location" then
 				info['pages'][page][comp]=getLocationInfo()
+			elseif comp=="freqlist" then
+				info['pages'][page][comp]=getFreqList()
 			end
 		end
 	elseif page=="mesh" then
@@ -201,7 +215,14 @@ for page, comps in pairs(qsset) do
 				info['pages'][page][comp]=getServicesByService()
 			end
 		end
-	end
+	elseif page=="scan" then
+		for i,comp in pairs(comps:split(',')) do
+				if comp=="scanlist" then
+					info['pages'][page][comp]=getScanList()
+				end
+		end
+end
+
 end
 
 -- Output the HTTP header for JSON