Merge pull request #1819 from Ansuel/ddns-performance

luci-app-ddns: improve performance

6 files changed, 230 insertions, 96 deletions

diff --git a/applications/luci-app-ddns/Makefile b/applications/luci-app-ddns/Makefile
index bd6ddeb1b..886b266b0 100644
--- a/applications/luci-app-ddns/Makefile
+++ b/applications/luci-app-ddns/Makefile
@@ -16,7 +16,7 @@ PKG_VERSION:=2.4.9
 
 # Release == build
 # increase on changes of translation files
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 
 PKG_LICENSE:=Apache-2.0
 PKG_MAINTAINER:=Christian Schoenebeck <christian.schoenebeck@gmail.com>
diff --git a/applications/luci-app-ddns/luasrc/controller/ddns.lua b/applications/luci-app-ddns/luasrc/controller/ddns.lua
index 5f4a5118c..bfd7a2a41 100755
--- a/applications/luci-app-ddns/luasrc/controller/ddns.lua
+++ b/applications/luci-app-ddns/luasrc/controller/ddns.lua
@@ -21,7 +21,6 @@ luci_helper = "/usr/lib/ddns/dynamic_dns_lucihelper.sh"
 
 local srv_name    = "ddns-scripts"
 local srv_ver_min = "2.7.7"			-- minimum version of service required
-local srv_ver_cmd = luci_helper .. [[ -V | awk {'print $2'}]]
 local app_name    = "luci-app-ddns"
 local app_title   = "Dynamic DNS"
 local app_version = "2.4.9-1"
@@ -29,7 +28,6 @@ local app_version = "2.4.9-1"
 function index()
 	local nxfs	= require "nixio.fs"		-- global definitions not available
 	local sys	= require "luci.sys"		-- in function index()
-	local ddns	= require "luci.tools.ddns"	-- ddns multiused functions
 	local muci	= require "luci.model.uci"
 
 	-- no config create an empty one
@@ -81,26 +79,41 @@ end
 
 -- Standardized application/service functions
 function app_title_main()
-	return	[[<a href="javascript:alert(']]
-			.. I18N.translate("Version Information")
-			.. [[\n\n]] .. app_name
-			.. [[\n\t]] .. I18N.translate("Version") .. [[:\t]] .. app_version
-			.. [[\n\n]] .. srv_name .. [[ ]] .. I18N.translate("required") .. [[:]]
-			.. [[\n\t]] .. I18N.translate("Version") .. [[:\t]]
-				.. srv_ver_min .. [[ ]] .. I18N.translate("or higher")
-			.. [[\n\n]] .. srv_name .. [[ ]] .. I18N.translate("installed") .. [[:]]
-			.. [[\n\t]] .. I18N.translate("Version") .. [[:\t]]
-				.. (service_version() or I18N.translate("NOT installed"))
-			.. [[\n\n]]
-	 	.. [[')">]]
-		.. I18N.translate(app_title)
-		.. [[</a>]]
+	tmp = {}
+	tmp[#tmp+1] = 	[[<a href="javascript:alert(']]
+	tmp[#tmp+1] = 		 I18N.translate("Version Information")
+	tmp[#tmp+1] = 		 [[\n\n]] .. app_name
+	tmp[#tmp+1] = 		 [[\n\t]] .. I18N.translate("Version") .. [[:\t]] .. app_version
+	tmp[#tmp+1] = 		 [[\n\n]] .. srv_name .. [[ ]] .. I18N.translate("required") .. [[:]]
+	tmp[#tmp+1] = 		 [[\n\t]] .. I18N.translate("Version") .. [[:\t]]
+	tmp[#tmp+1] = 			 srv_ver_min .. [[ ]] .. I18N.translate("or higher")
+	tmp[#tmp+1] = 		 [[\n\n]] .. srv_name .. [[ ]] .. I18N.translate("installed") .. [[:]]
+	tmp[#tmp+1] = 		 [[\n\t]] .. I18N.translate("Version") .. [[:\t]]
+	tmp[#tmp+1] = 			 (service_version() or I18N.translate("NOT installed"))
+	tmp[#tmp+1] = 		 [[\n\n]]
+	tmp[#tmp+1] = 	 [[')">]]
+	tmp[#tmp+1] = 	 I18N.translate(app_title)
+	tmp[#tmp+1] = 	 [[</a>]]
+		
+	return table.concat(tmp)
 end
 function service_version()
-	local ver = nil
 
+	local nxfs	= require "nixio.fs"
+
+	local ver = nil
+	local ver_helper
+	
+	if nxfs.access("/bin/opkg") then
+		ver_helper = "/bin/opkg info " .. srv_name .. " | grep 'Version'"
+	else
+		ver_helper = luci_helper .. " -V"
+	end
+	
+	local srv_ver_cmd = ver_helper .. " | awk {'print $2'} "
+	
 	ver = UTIL.exec(srv_ver_cmd)
-	if #ver > 0 then return ver end
+	if ver and #ver > 0 then return ver end
 
 	IPKG.list_installed(srv_name, function(n, v, d)
 			if v and (#v > 0) then ver = v end
@@ -108,6 +121,7 @@ function service_version()
 	)
 	return	ver
 end
+
 function service_ok()
 	return	IPKG.compare_versions((service_version() or "0"), ">=", srv_ver_min)
 end
diff --git a/applications/luci-app-ddns/luasrc/model/cbi/ddns/detail.lua b/applications/luci-app-ddns/luasrc/model/cbi/ddns/detail.lua
index 977dbe34b..10d39c718 100644
--- a/applications/luci-app-ddns/luasrc/model/cbi/ddns/detail.lua
+++ b/applications/luci-app-ddns/luasrc/model/cbi/ddns/detail.lua
@@ -292,6 +292,10 @@ function luh.parse(self, section, novld)
 end
 
 -- use_ipv6 -- ################################################################
+
+--We call it globally as it's called 11 times even outside specific function, saves 11 os.execute slow command!
+local has_ipv6 = DDNS.env_info("has_ipv6") 
+
 usev6 = ns:taboption("basic", ListValue, "use_ipv6",
 	translate("IP address version"),
 	translate("Defines which IP address 'IPv4/IPv6' is send to the DDNS provider") )
@@ -300,16 +304,16 @@ usev6.default = "0"
 usev6:value("0", translate("IPv4-Address") )
 function usev6.cfgvalue(self, section)
 	local value = AbstractValue.cfgvalue(self, section) or "0"
-	if DDNS.has_ipv6 or (value == "1" and not DDNS.has_ipv6) then
+	if has_ipv6 or (value == "1" and not has_ipv6) then
 		self:value("1", translate("IPv6-Address") )
 	end
-	if value == "1" and not DDNS.has_ipv6 then
+	if value == "1" and not has_ipv6 then
 		self.description = err_ipv6_basic
 	end
 	return value
 end
 function usev6.validate(self, value)
-	if (value == "1" and DDNS.has_ipv6) or value == "0" then
+	if (value == "1" and has_ipv6) or value == "0" then
 		return value
 	end
 	return nil, err_tab_basic(self) .. err_ipv6_plain
@@ -360,7 +364,7 @@ svc6 = ns:taboption("basic", ListValue, "ipv6_service_name",
 	translate("DDNS Service provider") .. " [IPv6]" )
 svc6.default	= "-"
 svc6:depends("use_ipv6", "1")	-- only show on IPv6
-if not DDNS.has_ipv6 then
+if not has_ipv6 then
 	svc6.description = err_ipv6_basic
 end
 function svc6.cfgvalue(self, section)
@@ -374,7 +378,7 @@ function svc6.cfgvalue(self, section)
 end
 function svc6.validate(self, value)
 	if usev6:formvalue(section) == "1" then	-- do only on IPv6
-		if DDNS.has_ipv6 then return value end
+		if has_ipv6 then return value end
 		return nil, err_tab_basic(self) .. err_ipv6_plain
 	else
 		return ""	-- suppress validate error
@@ -586,13 +590,17 @@ end
 svc6:value("-", translate("-- custom --") )
 
 -- IPv4/IPv6 - use_https -- ###################################################
-if DDNS.has_ssl or ( ( m:get(section, "use_https") or "0" ) == "1" ) then
+
+--We call it globally as it's called 4 times outside specific function.
+local has_ssl = DDNS.env_info("has_ssl")
+
+if has_ssl or ( ( m:get(section, "use_https") or "0" ) == "1" ) then
 	https = ns:taboption("basic", Flag, "use_https",
 		translate("Use HTTP Secure") )
 	https.orientation = "horizontal"
 	function https.cfgvalue(self, section)
 		local value = AbstractValue.cfgvalue(self, section)
-		if not DDNS.has_ssl and value == "1" then
+		if not has_ssl and value == "1" then
 			self.description = bold_on .. font_red ..
 				translate("HTTPS not supported") .. font_off .. "<br />" ..
 				translate("please disable") .. " !" .. bold_off
@@ -602,7 +610,7 @@ if DDNS.has_ssl or ( ( m:get(section, "use_https") or "0" ) == "1" ) then
 		return value
 	end
 	function https.validate(self, value)
-		if (value == "1" and DDNS.has_ssl ) or value == "0" then return value end
+		if (value == "1" and has_ssl ) or value == "0" then return value end
 		return nil, err_tab_basic(self) .. translate("HTTPS not supported") .. " !"
 	end
 	function https.write(self, section, value)
@@ -616,7 +624,7 @@ if DDNS.has_ssl or ( ( m:get(section, "use_https") or "0" ) == "1" ) then
 end
 
 -- IPv4/IPv6 - cacert -- ######################################################
-if DDNS.has_ssl then
+if has_ssl then
 	cert = ns:taboption("basic", Value, "cacert",
 		translate("Path to CA-Certificate"),
 		translate("directory or path/file") .. "<br />" ..
@@ -706,7 +714,7 @@ src6:value("network", translate("Network"))
 src6:value("web", translate("URL"))
 src6:value("interface", translate("Interface"))
 src6:value("script", translate("Script"))
-if not DDNS.has_ipv6 then
+if not has_ipv6 then
 	src6.description = err_ipv6_other
 end
 function src6.cfgvalue(self, section)
@@ -715,7 +723,7 @@ end
 function src6.validate(self, value)
 	if usev6:formvalue(section) ~= "1" then
 		return ""	-- ignore on IPv4 selected
-	elseif not DDNS.has_ipv6 then
+	elseif not has_ipv6 then
 		return nil, err_tab_adv(self) .. err_ipv6_plain
 	elseif not _verify_ip_source() then
 		return nil, err_tab_adv(self) ..
@@ -794,7 +802,7 @@ ipn6 = ns:taboption("advanced", ListValue, "ipv6_network",
 ipn6:depends("ipv6_source", "network")
 ipn6.default = "wan6"
 WADM.cbi_add_networks(ipn6)
-if DDNS.has_ipv6 then
+if has_ipv6 then
 	ipn6.description = translate("Defines the network to read systems IPv6-Address from")
 else
 	ipn6.description = err_ipv6_other
@@ -808,7 +816,7 @@ function ipn6.validate(self, value)
 		-- ignore if IPv4 selected OR
 		-- ignore everything except "network"
 		return ""
-	elseif DDNS.has_ipv6 then
+	elseif has_ipv6 then
 		return value
 	else
 		return nil, err_tab_adv(self) .. err_ipv6_plain
@@ -881,7 +889,7 @@ iurl6 = ns:taboption("advanced", Value, "ipv6_url",
 	translate("URL to detect") .. " [IPv6]" )
 iurl6:depends("ipv6_source", "web")
 iurl6.default = "http://checkipv6.dyndns.com"
-if DDNS.has_ipv6 then
+if has_ipv6 then
 	iurl6.description = translate("Defines the Web page to read systems IPv6-Address from")
 else
 	iurl6.description = err_ipv6_other
@@ -895,7 +903,7 @@ function iurl6.validate(self, value)
 		-- ignore if IPv4 selected OR
 		-- ignore everything except "web"
 		return ""
-	elseif not DDNS.has_ipv6 then
+	elseif not has_ipv6 then
 		return nil, err_tab_adv(self) .. err_ipv6_plain
 	elseif not value or #value == 0 then
 		return nil, err_tab_adv(self) .. translate("missing / required")
@@ -1051,7 +1059,7 @@ eif6:depends("ipv6_source", "web")
 eif6:depends("ipv6_source", "script")
 eif6.default = "wan6"
 WADM.cbi_add_networks(eif6)
-if not DDNS.has_ipv6 then
+if not has_ipv6 then
 	eif6.description = err_ipv6_other
 else
 	eif6.description = translate("Network on which the ddns-updater scripts will be started")
@@ -1065,7 +1073,7 @@ function eif6.validate(self, value)
 	 or fsrc6 == "network"
 	 or fsrc6 == "interface" then
 		return ""	-- ignore IPv4, network, interface
-	elseif not DDNS.has_ipv6 then
+	elseif not has_ipv6 then
 		return nil, err_tab_adv(self) .. err_ipv6_plain
 	else
 		return value
@@ -1084,10 +1092,13 @@ function eif6.write(self, section, value)
 end
 function eif6.parse(self, section, novld)
 	DDNS.value_parse(self, section, novld)
-end
+end 
 
 -- IPv4/IPv6 - bind_network -- ################################################
-if DDNS.has_bindnet or ( ( m:get(section, "bind_network") or "" ) ~= "" ) then
+
+local has_bindnet = DDNS.env_info("has_bindnet")
+
+if has_bindnet or ( ( m:get(section, "bind_network") or "" ) ~= "" ) then
 	bnet = ns:taboption("advanced", ListValue, "bind_network",
 		translate("Bind Network") )
 	bnet:depends("ipv4_source", "web")
@@ -1097,7 +1108,7 @@ if DDNS.has_bindnet or ( ( m:get(section, "bind_network") or "" ) ~= "" ) then
 	WADM.cbi_add_networks(bnet)
 	function bnet.cfgvalue(self, section)
 		local value = AbstractValue.cfgvalue(self, section)
-		if not DDNS.has_bindnet and value ~= "" then
+		if not has_bindnet and value ~= "" then
 			self.description = bold_on .. font_red ..
 				translate("Binding to a specific network not supported") .. font_off .. "<br />" ..
 				translate("please set to 'default'") .. " !" .. bold_off
@@ -1108,7 +1119,7 @@ if DDNS.has_bindnet or ( ( m:get(section, "bind_network") or "" ) ~= "" ) then
 		return value
 	end
 	function bnet.validate(self, value)
-		if ( (value ~= "") and DDNS.has_bindnet ) or (value == "") then return value end
+		if ( (value ~= "") and has_bindnet ) or (value == "") then return value end
 		return nil, err_tab_adv(self) .. translate("Binding to a specific network not supported") .. " !"
 	end
 	function bnet.parse(self, section, novld)
@@ -1119,13 +1130,16 @@ end
 -- IPv4 + IPv6 - force_ipversion -- ###########################################
 -- optional to force wget/curl and host to use only selected IP version
 -- command parameter "-4" or "-6"
-if DDNS.has_forceip or ( ( m:get(section, "force_ipversion") or "0" ) ~= "0" ) then
+
+local has_forceip = DDNS.env_info("has_forceip")
+
+if has_forceip or ( ( m:get(section, "force_ipversion") or "0" ) ~= "0" ) then
 	fipv = ns:taboption("advanced", Flag, "force_ipversion",
 		translate("Force IP Version") )
 	fipv.orientation = "horizontal"
 	function fipv.cfgvalue(self, section)
 		local value = AbstractValue.cfgvalue(self, section)
-		if not DDNS.has_forceip and value ~= "0" then
+		if not has_forceip and value ~= "0" then
 			self.description = bold_on .. font_red ..
 				translate("Force IP Version not supported") .. font_off .. "<br />" ..
 				translate("please disable") .. " !" .. bold_off
@@ -1135,14 +1149,17 @@ if DDNS.has_forceip or ( ( m:get(section, "force_ipversion") or "0" ) ~= "0" ) t
 		return value
 	end
 	function fipv.validate(self, value)
-		if (value == "1" and DDNS.has_forceip) or value == "0" then return value end
+		if (value == "1" and has_forceip) or value == "0" then return value end
 		return nil, err_tab_adv(self) .. translate("Force IP Version not supported")
 	end
 end
 
 -- IPv4 + IPv6 - dns_server -- ################################################
 -- optional DNS Server to use resolving my IP
-if DDNS.has_dnsserver or ( ( m:get(section, "dns_server") or "" ) ~= "" ) then
+
+local has_dnsserver = DDNS.env_info("has_dnsserver")
+
+if has_dnsserver or ( ( m:get(section, "dns_server") or "" ) ~= "" ) then
 	dns = ns:taboption("advanced", Value, "dns_server",
 		translate("DNS-Server"),
 		translate("OPTIONAL: Use non-default DNS-Server to detect 'Registered IP'.") .. "<br />" ..
@@ -1152,7 +1169,7 @@ if DDNS.has_dnsserver or ( ( m:get(section, "dns_server") or "" ) ~= "" ) then
 		-- if .datatype is set, then it is checked before calling this function
 		if not value or (#value == 0) then
 			return ""	-- ignore on empty
-		elseif not DDNS.has_dnsserver then
+		elseif not has_dnsserver then
 			return nil, err_tab_adv(self) .. translate("Specifying a DNS-Server is not supported")
 		elseif not DTYP.host(value) then
 			return nil, err_tab_adv(self) .. translate("use hostname, FQDN, IPv4- or IPv6-Address")
@@ -1179,13 +1196,16 @@ if DDNS.has_dnsserver or ( ( m:get(section, "dns_server") or "" ) ~= "" ) then
 end
 
 -- IPv4 + IPv6 - force_dnstcp -- ##############################################
-if DDNS.has_bindhost or ( ( m:get(section, "force_dnstcp") or "0" ) ~= "0" ) then
+
+local has_bindhost = DDNS.env_info("has_bindhost")
+
+if has_bindhost or ( ( m:get(section, "force_dnstcp") or "0" ) ~= "0" ) then
 	tcp = ns:taboption("advanced", Flag, "force_dnstcp",
 		translate("Force TCP on DNS") )
 	tcp.orientation = "horizontal"
 	function tcp.cfgvalue(self, section)
 		local value = AbstractValue.cfgvalue(self, section)
-		if not DDNS.has_bindhost and value ~= "0" then
+		if not has_bindhost and value ~= "0" then
 			self.description = bold_on .. font_red ..
 				translate("DNS requests via TCP not supported") .. font_off .. "<br />" ..
 				translate("please disable") .. " !" .. bold_off
@@ -1195,7 +1215,7 @@ if DDNS.has_bindhost or ( ( m:get(section, "force_dnstcp") or "0" ) ~= "0" ) the
 		return value
 	end
 	function tcp.validate(self, value)
-		if (value == "1" and DDNS.has_bindhost ) or value == "0" then
+		if (value == "1" and has_bindhost ) or value == "0" then
 			return value
 		end
 		return nil, err_tab_adv(self) .. translate("DNS requests via TCP not supported")
@@ -1204,13 +1224,16 @@ end
 
 -- IPv4 + IPv6 - proxy -- #####################################################
 -- optional Proxy to use for http/https requests  [user:password@]proxyhost[:port]
-if DDNS.has_proxy or ( ( m:get(section, "proxy") or "" ) ~= "" ) then
+
+local has_proxy = DDNS.env_info("has_proxy")
+
+if has_proxy or ( ( m:get(section, "proxy") or "" ) ~= "" ) then
 	pxy = ns:taboption("advanced", Value, "proxy",
 		translate("PROXY-Server") )
 	pxy.placeholder="user:password@myproxy.lan:8080"
 	function pxy.cfgvalue(self, section)
 		local value = AbstractValue.cfgvalue(self, section)
-		if not DDNS.has_proxy and value ~= "" then
+		if not has_proxy and value ~= "" then
 			self.description = bold_on .. font_red ..
 				translate("PROXY-Server not supported") .. font_off .. "<br />" ..
 				translate("please remove entry") .. "!" .. bold_off
@@ -1226,7 +1249,7 @@ if DDNS.has_proxy or ( ( m:get(section, "proxy") or "" ) ~= "" ) then
 		-- if .datatype is set, then it is checked before calling this function
 		if not value or (#value == 0) then
 			return ""	-- ignore on empty
-		elseif DDNS.has_proxy then
+		elseif has_proxy then
 			local ipv6  = usev6:formvalue(section) or "0"
 			local force = fipv:formvalue(section) or "0"
 			local command = CTRL.luci_helper .. [[ -]]
diff --git a/applications/luci-app-ddns/luasrc/model/cbi/ddns/hints.lua b/applications/luci-app-ddns/luasrc/model/cbi/ddns/hints.lua
index df39a3a7e..419201548 100644
--- a/applications/luci-app-ddns/luasrc/model/cbi/ddns/hints.lua
+++ b/applications/luci-app-ddns/luasrc/model/cbi/ddns/hints.lua
@@ -48,7 +48,7 @@ if not SYS.init.enabled("ddns") then
 end
 
 -- No IPv6 support
-if not DDNS.has_ipv6 then
+if not DDNS.env_info("has_ipv6") then
 	local v6 = s:option(DummyValue, "_no_ipv6")
 	v6.titleref = 'http://www.openwrt.org" target="_blank'
 	v6.rawhtml  = true
@@ -60,7 +60,7 @@ if not DDNS.has_ipv6 then
 end
 
 -- No HTTPS support
-if not DDNS.has_ssl then
+if not DDNS.env_info("has_ssl") then
 	local sl = s:option(DummyValue, "_no_https")
 	sl.titleref = DISP.build_url("admin", "system", "packages")
 	sl.rawhtml  = true
@@ -74,7 +74,7 @@ if not DDNS.has_ssl then
 end
 
 -- No bind_network
-if not DDNS.has_bindnet then
+if not DDNS.env_info("has_bindnet") then
 	local bn = s:option(DummyValue, "_no_bind_network")
 	bn.titleref = DISP.build_url("admin", "system", "packages")
 	bn.rawhtml  = true
@@ -90,7 +90,7 @@ if not DDNS.has_bindnet then
 end
 
 -- currently only cURL possibly without proxy support
-if not DDNS.has_proxy then
+if not DDNS.env_info("has_proxy") then
 	local px = s:option(DummyValue, "_no_proxy")
 	px.titleref = DISP.build_url("admin", "system", "packages")
 	px.rawhtml  = true
@@ -104,7 +104,7 @@ if not DDNS.has_proxy then
 end
 
 -- "Force IP Version not supported"
-if not DDNS.has_forceip then
+if not DDNS.env_info("has_forceip") then
 	local fi = s:option(DummyValue, "_no_force_ip")
 	fi.titleref = DISP.build_url("admin", "system", "packages")
 	fi.rawhtml  = true
@@ -112,11 +112,11 @@ if not DDNS.has_forceip then
 		translate("Force IP Version not supported") .. bold_off
 	local value = translate("BusyBox's nslookup and Wget do not support to specify " ..
 				"the IP version to use for communication with DDNS Provider!")
-	if not (DDNS.has_wgetssl or DDNS.has_curl or DDNS.has_fetch) then
+	if not (DDNS.env_info("has_wgetssl") or DDNS.env_info("has_curl") or DDNS.env_info("has_fetch")) then
 		value = value .. "<br />- " ..
 			translate("You should install 'wget' or 'curl' or 'uclient-fetch' package.")
 	end
-	if not DDNS.has_bindhost then
+	if not DDNS.env_info("has_bindhost") then
 		value = value .. "<br />- " ..
 			translate("You should install 'bind-host' or 'knot-host' or 'drill' package for DNS requests.")
 	end
@@ -124,7 +124,7 @@ if not DDNS.has_forceip then
 end
 
 -- "DNS requests via TCP not supported"
-if not DDNS.has_bindhost then
+if not DDNS.env_info("has_bindhost") then
 	local dt = s:option(DummyValue, "_no_dnstcp")
 	dt.titleref = DISP.build_url("admin", "system", "packages")
 	dt.rawhtml  = true
@@ -137,7 +137,7 @@ if not DDNS.has_bindhost then
 end
 
 -- nslookup compiled with musl produce problems when using
-if not DDNS.has_dnsserver then
+if not DDNS.env_info("has_dnsserver") then
 	local ds = s:option(DummyValue, "_no_dnsserver")
 	ds.titleref = DISP.build_url("admin", "system", "packages")
 	ds.rawhtml  = true
@@ -151,7 +151,7 @@ if not DDNS.has_dnsserver then
 end
 
 -- certificates installed
-if DDNS.has_ssl and not DDNS.has_cacerts then
+if DDNS.env_info("has_ssl") and not DDNS.env_info("has_cacerts") then
 	local ca = s:option(DummyValue, "_no_certs")
 	ca.titleref = DISP.build_url("admin", "system", "packages")
 	ca.rawhtml  = true
diff --git a/applications/luci-app-ddns/luasrc/model/cbi/ddns/overview.lua b/applications/luci-app-ddns/luasrc/model/cbi/ddns/overview.lua
index 114f831c1..11f73800e 100644
--- a/applications/luci-app-ddns/luasrc/model/cbi/ddns/overview.lua
+++ b/applications/luci-app-ddns/luasrc/model/cbi/ddns/overview.lua
@@ -1,21 +1,20 @@
 -- Copyright 2014-2018 Christian Schoenebeck <christian dot schoenebeck at gmail dot com>
 -- Licensed to the public under the Apache License 2.0.
 
-local NXFS = require "nixio.fs"
 local DISP = require "luci.dispatcher"
 local HTTP = require "luci.http"
 local SYS  = require "luci.sys"
 local CTRL = require "luci.controller.ddns"	-- this application's controller
 local DDNS = require "luci.tools.ddns"		-- ddns multiused functions
 
-local show_hints = not (DDNS.has_ipv6		-- IPv6 support
-		    and DDNS.has_ssl		-- HTTPS support
-		    and DDNS.has_proxy		-- Proxy support
-		    and DDNS.has_bindhost	-- DNS TCP support
-		    and DDNS.has_forceip	-- Force IP version
-		    and DDNS.has_dnsserver	-- DNS server support
-		    and DDNS.has_bindnet	-- Bind to network/interface
-		    and DDNS.has_cacerts	-- certificates installed at /etc/ssl/certs
+local show_hints = not (DDNS.env_info("has_ipv6")		-- IPv6 support
+				   and  DDNS.env_info("has_ssl")		-- HTTPS support
+				   and  DDNS.env_info("has_proxy")		-- Proxy support
+				   and  DDNS.env_info("has_bindhost")	-- DNS TCP support
+				   and  DDNS.env_info("has_forceip")	-- Force IP version
+				   and  DDNS.env_info("has_dnsserver")	-- DNS server support
+				   and  DDNS.env_info("has_bindnet")	-- Bind to network/interface
+				   and  DDNS.env_info("has_cacerts")	-- certificates installed at /etc/ssl/certs
 		)
 local not_enabled = not SYS.init.enabled("ddns")
 local need_update = not CTRL.service_ok()
diff --git a/applications/luci-app-ddns/luasrc/tools/ddns.lua b/applications/luci-app-ddns/luasrc/tools/ddns.lua
index 690b9b30c..57913a51f 100755
--- a/applications/luci-app-ddns/luasrc/tools/ddns.lua
+++ b/applications/luci-app-ddns/luasrc/tools/ddns.lua
@@ -5,36 +5,134 @@ module("luci.tools.ddns", package.seeall)
 
 local NX   = require "nixio"
 local NXFS = require "nixio.fs"
-local OPKG = require "luci.model.ipkg"
 local UCI  = require "luci.model.uci"
 local SYS  = require "luci.sys"
-local UTIL = require "luci.util"
 
-local function _check_certs()
-	local _, v = NXFS.glob("/etc/ssl/certs/*.crt")
-	if ( v == 0 ) then _, v = NXFS.glob("/etc/ssl/certs/*.pem") end
-	return (v > 0)
-end
+function env_info(type)
+
+	if ( type == "has_ssl" ) or ( type == "has_proxy" ) or ( type == "has_forceip" ) 
+	    or ( type == "has_bindnet" ) or ( type == "has_fetch" ) 
+		or ( type == "has_wgetssl" ) or ( type == "has_curl" ) 
+		or ( type == "has_curlssl" ) or ( type == "has_curlpxy" ) 
+		or ( type == "has_fetchssl" ) or ( type == "has_bbwget" ) then 
+		
+		local function has_wgetssl() 
+			return (SYS.call( [[which wget-ssl >/dev/null 2>&1]] ) == 0)	-- and true or nil
+		end
+		
+		local function has_curlssl() 
+			return (SYS.call( [[$(which curl) -V 2>&1 | grep "Protocols:" | grep -qF "https"]] ) ~= 0)
+		end
+		
+		local function has_fetch()
+			return (SYS.call( [[which uclient-fetch >/dev/null 2>&1]] ) == 0)
+		end
+		
+		local function has_fetchssl()
+			return NXFS.access("/lib/libustream-ssl.so")
+		end
+		
+		local function has_curl()
+			return (SYS.call( [[which curl >/dev/null 2>&1]] ) == 0)
+		end
+		
+		local function has_curlpxy()
+			return (SYS.call( [[grep -i "all_proxy" /usr/lib/libcurl.so* >/dev/null 2>&1]] ) == 0)
+		end
+		
+		local function has_bbwget()
+			return (SYS.call( [[$(which wget) -V 2>&1 | grep -iqF "busybox"]] ) == 0)
+		end
+		
+		if type == "has_wgetssl" then
+			return has_wgetssl()
+		
+		elseif type == "has_curl" then
+			return has_curl()
+			
+		elseif type == "has_curlssl" then
+			return has_curlssl()
+			
+		elseif type == "has_curlpxy" then
+			return has_curlpxy()
+			
+		elseif type == "has_fetch" then
+			return has_fetch()
+			
+		elseif type == "has_fetchssl" then
+			return has_fetchssl()
+			
+		elseif type == "has_bbwget" then
+			return has_bbwget()
+		
+		elseif type == "has_ssl" then
+			if has_wgetssl() then return true end
+			if has_curlssl() then return true end
+			if (has_fetch() and has_fetchssl()) then return true end
+			return false
+			
+		elseif type == "has_proxy" then
+			if has_wgetssl() then return true end
+			if has_curlpxy() then return true end
+			if has_fetch() then return true end
+			if has_bbwget() then return true end
+			return false
+			
+		elseif type == "has_forceip" then
+			if has_wgetssl() then return true end
+			if has_curl() then return true end
+			if has_fetch() then return true end -- only really needed for transfer
+			return false
+			
+		elseif type == "has_bindnet" then
+			if has_curl() then return true end
+			if has_wgetssl() then return true end
+			return false
+		end
+	
+	elseif ( type == "has_dnsserver" ) or ( type == "has_bindhost" ) or ( type == "has_hostip" ) or ( type == "has_nslookup" ) then
+		local function has_bindhost() 
+			if (SYS.call( [[which host >/dev/null 2>&1]] ) == 0) then return true end
+			if (SYS.call( [[which host >/dev/null 2>&1]] ) == 0) then return true end
+			if (SYS.call( [[which khost >/dev/null 2>&1]] ) == 0) then return true end
+			if (SYS.call( [[which drill >/dev/null 2>&1]] ) == 0) then return true end
+			return false
+		end
+		
+		local function has_hostip()
+			return (SYS.call( [[which hostip >/dev/null 2>&1]] ) == 0)
+		end
+		
+		local function has_nslookup()
+			return (SYS.call( [[$(which nslookup) localhost 2>&1 | grep -qF "(null)"]] ) ~= 0)
+		end
+		
+		if type == "has_bindhost" then
+			return has_bindhost()
+		elseif type == "has_hostip" then
+			return has_hostip()
+		elseif type == "has_nslookup" then
+			return has_nslookup()
+		elseif tyep == "has_dnsserver" then
+			if has_bindhost() then return true end
+			if has_hostip() then return true end
+			if has_nslookup() then return true end
+			return false
+		end
+		
+	elseif type == "has_ipv6" then
+		return (NXFS.access("/proc/net/ipv6_route") and NXFS.access("/usr/sbin/ip6tables"))
+		
+	elseif type == "has_cacerts" then
+		--old _check_certs() local function 
+		local _, v = NXFS.glob("/etc/ssl/certs/*.crt")
+		if ( v == 0 ) then _, v = NXFS.glob("/etc/ssl/certs/*.pem") end
+		return (v > 0)
+	else
+		return
+	end
 
-has_wgetssl	= (SYS.call( [[which wget-ssl >/dev/null 2>&1]] ) == 0)	-- and true or nil
-has_curl	= (SYS.call( [[which curl >/dev/null 2>&1]] ) == 0)
-has_curlssl	= (SYS.call( [[$(which curl) -V 2>&1 | grep "Protocols:" | grep -qF "https"]] ) ~= 0)
-has_curlpxy	= (SYS.call( [[grep -i "all_proxy" /usr/lib/libcurl.so* >/dev/null 2>&1]] ) == 0)
-has_fetch	= (SYS.call( [[which uclient-fetch >/dev/null 2>&1]] ) == 0)
-has_fetchssl	= NXFS.access("/lib/libustream-ssl.so")
-has_bbwget	= (SYS.call( [[$(which wget) -V 2>&1 | grep -iqF "busybox"]] ) == 0)
-has_bindhost	= (SYS.call( [[which host >/dev/null 2>&1]] ) == 0)
-		or (SYS.call( [[which khost >/dev/null 2>&1]] ) == 0)
-		or (SYS.call( [[which drill >/dev/null 2>&1]] ) == 0)
-has_hostip	= (SYS.call( [[which hostip >/dev/null 2>&1]] ) == 0)
-has_nslookup	= (SYS.call( [[$(which nslookup) localhost 2>&1 | grep -qF "(null)"]] ) ~= 0)
-has_ipv6	= (NXFS.access("/proc/net/ipv6_route") and NXFS.access("/usr/sbin/ip6tables"))
-has_ssl		= (has_wgetssl or has_curlssl or (has_fetch and has_fetchssl))
-has_proxy	= (has_wgetssl or has_curlpxy or has_fetch or has_bbwget)
-has_forceip	= (has_wgetssl or has_curl or has_fetch) -- only really needed for transfer
-has_dnsserver	= (has_bindhost or has_hostip or has_nslookup)
-has_bindnet	= (has_wgetssl or has_curl)
-has_cacerts	= _check_certs()
+end
 
 -- function to calculate seconds from given interval and unit
 function calc_seconds(interval, unit)