luci-base: move some generic classes into a separate luci-base-libs package

The new package luci-base-libs provides the modules that not strictly relate
to the web-interface of luci. By separating these libs they can be used by
other packages without having to install the web-components.
This change was inspired by providing a shell-only interface for 4MB-flash
devices, by keeping as much code common with a full install.

Signed-off-by: Sven Roederer <freifunk@it-solutions.geroedel.de>

6 files changed, 2356 insertions, 0 deletions

diff --git a/libs/luci-lib-base/luasrc/debug.lua b/libs/luci-lib-base/luasrc/debug.lua
new file mode 100644
index 0000000000..8ff1bb6981
--- /dev/null
+++ b/libs/luci-lib-base/luasrc/debug.lua
@@ -0,0 +1,37 @@
+local debug = require "debug"
+local io = require "io"
+local collectgarbage, floor = collectgarbage, math.floor
+
+module "luci.debug"
+__file__ = debug.getinfo(1, 'S').source:sub(2)
+
+-- Enables the memory tracer with given flags and returns a function to disable the tracer again
+function trap_memtrace(flags, dest)
+	flags = flags or "clr"
+	local tracefile = io.open(dest or "/tmp/memtrace", "w")
+	local peak = 0
+
+	local function trap(what, line)
+		local info = debug.getinfo(2, "Sn")
+		local size = floor(collectgarbage("count"))
+		if size > peak then
+			peak = size
+		end
+		if tracefile then
+			tracefile:write(
+				"[", what, "] ", info.source, ":", (line or "?"), "\t",
+				(info.namewhat or ""), "\t",
+				(info.name or ""), "\t",
+				size, " (", peak, ")\n"
+			)
+		end
+	end
+
+	debug.sethook(trap, flags)
+
+	return function()
+		debug.sethook()
+		tracefile:close()
+	end
+end
+
diff --git a/libs/luci-lib-base/luasrc/http.lua b/libs/luci-lib-base/luasrc/http.lua
new file mode 100644
index 0000000000..20b55f2854
--- /dev/null
+++ b/libs/luci-lib-base/luasrc/http.lua
@@ -0,0 +1,554 @@
+-- Copyright 2008 Steven Barth <steven@midlink.org>
+-- Copyright 2010-2018 Jo-Philipp Wich <jo@mein.io>
+-- Licensed to the public under the Apache License 2.0.
+
+local util  = require "luci.util"
+local coroutine = require "coroutine"
+local table = require "table"
+local lhttp = require "lucihttp"
+local nixio = require "nixio"
+local ltn12 = require "luci.ltn12"
+
+local table, ipairs, pairs, type, tostring, tonumber, error =
+	table, ipairs, pairs, type, tostring, tonumber, error
+
+module "luci.http"
+
+HTTP_MAX_CONTENT      = 1024*100		-- 100 kB maximum content size
+
+context = util.threadlocal()
+
+Request = util.class()
+function Request.__init__(self, env, sourcein, sinkerr)
+	self.input = sourcein
+	self.error = sinkerr
+
+
+	-- File handler nil by default to let .content() work
+	self.filehandler = nil
+
+	-- HTTP-Message table
+	self.message = {
+		env = env,
+		headers = {},
+		params = urldecode_params(env.QUERY_STRING or ""),
+	}
+
+	self.parsed_input = false
+end
+
+function Request.formvalue(self, name, noparse)
+	if not noparse and not self.parsed_input then
+		self:_parse_input()
+	end
+
+	if name then
+		return self.message.params[name]
+	else
+		return self.message.params
+	end
+end
+
+function Request.formvaluetable(self, prefix)
+	local vals = {}
+	prefix = prefix and prefix .. "." or "."
+
+	if not self.parsed_input then
+		self:_parse_input()
+	end
+
+	local void = self.message.params[nil]
+	for k, v in pairs(self.message.params) do
+		if k:find(prefix, 1, true) == 1 then
+			vals[k:sub(#prefix + 1)] = tostring(v)
+		end
+	end
+
+	return vals
+end
+
+function Request.content(self)
+	if not self.parsed_input then
+		self:_parse_input()
+	end
+
+	return self.message.content, self.message.content_length
+end
+
+function Request.getcookie(self, name)
+	return lhttp.header_attribute("cookie; " .. (self:getenv("HTTP_COOKIE") or ""), name)
+end
+
+function Request.getenv(self, name)
+	if name then
+		return self.message.env[name]
+	else
+		return self.message.env
+	end
+end
+
+function Request.setfilehandler(self, callback)
+	self.filehandler = callback
+
+	if not self.parsed_input then
+		return
+	end
+
+	-- If input has already been parsed then uploads are stored as unlinked
+	-- temporary files pointed to by open file handles in the parameter
+	-- value table. Loop all params, and invoke the file callback for any
+	-- param with an open file handle.
+	local name, value
+	for name, value in pairs(self.message.params) do
+		if type(value) == "table" then
+			while value.fd do
+				local data = value.fd:read(1024)
+				local eof = (not data or data == "")
+
+				callback(value, data, eof)
+
+				if eof then
+					value.fd:close()
+					value.fd = nil
+				end
+			end
+		end
+	end
+end
+
+function Request._parse_input(self)
+	parse_message_body(
+		 self.input,
+		 self.message,
+		 self.filehandler
+	)
+	self.parsed_input = true
+end
+
+function close()
+	if not context.eoh then
+		context.eoh = true
+		coroutine.yield(3)
+	end
+
+	if not context.closed then
+		context.closed = true
+		coroutine.yield(5)
+	end
+end
+
+function content()
+	return context.request:content()
+end
+
+function formvalue(name, noparse)
+	return context.request:formvalue(name, noparse)
+end
+
+function formvaluetable(prefix)
+	return context.request:formvaluetable(prefix)
+end
+
+function getcookie(name)
+	return context.request:getcookie(name)
+end
+
+-- or the environment table itself.
+function getenv(name)
+	return context.request:getenv(name)
+end
+
+function setfilehandler(callback)
+	return context.request:setfilehandler(callback)
+end
+
+function header(key, value)
+	if not context.headers then
+		context.headers = {}
+	end
+	context.headers[key:lower()] = value
+	coroutine.yield(2, key, value)
+end
+
+function prepare_content(mime)
+	if not context.headers or not context.headers["content-type"] then
+		if mime == "application/xhtml+xml" then
+			if not getenv("HTTP_ACCEPT") or
+			  not getenv("HTTP_ACCEPT"):find("application/xhtml+xml", nil, true) then
+				mime = "text/html; charset=UTF-8"
+			end
+			header("Vary", "Accept")
+		end
+		header("Content-Type", mime)
+	end
+end
+
+function source()
+	return context.request.input
+end
+
+function status(code, message)
+	code = code or 200
+	message = message or "OK"
+	context.status = code
+	coroutine.yield(1, code, message)
+end
+
+-- This function is as a valid LTN12 sink.
+-- If the content chunk is nil this function will automatically invoke close.
+function write(content, src_err)
+	if not content then
+		if src_err then
+			error(src_err)
+		else
+			close()
+		end
+		return true
+	elseif #content == 0 then
+		return true
+	else
+		if not context.eoh then
+			if not context.status then
+				status()
+			end
+			if not context.headers or not context.headers["content-type"] then
+				header("Content-Type", "text/html; charset=utf-8")
+			end
+			if not context.headers["cache-control"] then
+				header("Cache-Control", "no-cache")
+				header("Expires", "0")
+			end
+			if not context.headers["x-frame-options"] then
+				header("X-Frame-Options", "SAMEORIGIN")
+			end
+			if not context.headers["x-xss-protection"] then
+				header("X-XSS-Protection", "1; mode=block")
+			end
+			if not context.headers["x-content-type-options"] then
+				header("X-Content-Type-Options", "nosniff")
+			end
+
+			context.eoh = true
+			coroutine.yield(3)
+		end
+		coroutine.yield(4, content)
+		return true
+	end
+end
+
+function splice(fd, size)
+	coroutine.yield(6, fd, size)
+end
+
+function redirect(url)
+	if url == "" then url = "/" end
+	status(302, "Found")
+	header("Location", url)
+	close()
+end
+
+function build_querystring(q)
+	local s, n, k, v = {}, 1, nil, nil
+
+	for k, v in pairs(q) do
+		s[n+0] = (n == 1) and "?" or "&"
+		s[n+1] = util.urlencode(k)
+		s[n+2] = "="
+		s[n+3] = util.urlencode(v)
+		n = n + 4
+	end
+
+	return table.concat(s, "")
+end
+
+urldecode = util.urldecode
+
+urlencode = util.urlencode
+
+function write_json(x)
+	util.serialize_json(x, write)
+end
+
+-- from given url or string. Returns a table with urldecoded values.
+-- Simple parameters are stored as string values associated with the parameter
+-- name within the table. Parameters with multiple values are stored as array
+-- containing the corresponding values.
+function urldecode_params(url, tbl)
+	local parser, name
+	local params = tbl or { }
+
+	parser = lhttp.urlencoded_parser(function (what, buffer, length)
+		if what == parser.TUPLE then
+			name, value = nil, nil
+		elseif what == parser.NAME then
+			name = lhttp.urldecode(buffer)
+		elseif what == parser.VALUE and name then
+			params[name] = lhttp.urldecode(buffer) or ""
+		end
+
+		return true
+	end)
+
+	if parser then
+		parser:parse((url or ""):match("[^?]*$"))
+		parser:parse(nil)
+	end
+
+	return params
+end
+
+-- separated by "&". Tables are encoded as parameters with multiple values by
+-- repeating the parameter name with each value.
+function urlencode_params(tbl)
+	local k, v
+	local n, enc = 1, {}
+	for k, v in pairs(tbl) do
+		if type(v) == "table" then
+			local i, v2
+			for i, v2 in ipairs(v) do
+				if enc[1] then
+					enc[n] = "&"
+					n = n + 1
+				end
+
+				enc[n+0] = lhttp.urlencode(k)
+				enc[n+1] = "="
+				enc[n+2] = lhttp.urlencode(v2)
+				n = n + 3
+			end
+		else
+			if enc[1] then
+				enc[n] = "&"
+				n = n + 1
+			end
+
+			enc[n+0] = lhttp.urlencode(k)
+			enc[n+1] = "="
+			enc[n+2] = lhttp.urlencode(v)
+			n = n + 3
+		end
+	end
+
+	return table.concat(enc, "")
+end
+
+-- Content-Type. Stores all extracted data associated with its parameter name
+-- in the params table within the given message object. Multiple parameter
+-- values are stored as tables, ordinary ones as strings.
+-- If an optional file callback function is given then it is fed with the
+-- file contents chunk by chunk and only the extracted file name is stored
+-- within the params table. The callback function will be called subsequently
+-- with three arguments:
+--  o Table containing decoded (name, file) and raw (headers) mime header data
+--  o String value containing a chunk of the file data
+--  o Boolean which indicates whether the current chunk is the last one (eof)
+function mimedecode_message_body(src, msg, file_cb)
+	local parser, header, field
+	local len, maxlen = 0, tonumber(msg.env.CONTENT_LENGTH or nil)
+
+	parser, err = lhttp.multipart_parser(msg.env.CONTENT_TYPE, function (what, buffer, length)
+		if what == parser.PART_INIT then
+			field = { }
+
+		elseif what == parser.HEADER_NAME then
+			header = buffer:lower()
+
+		elseif what == parser.HEADER_VALUE and header then
+			if header:lower() == "content-disposition" and
+			   lhttp.header_attribute(buffer, nil) == "form-data"
+			then
+				field.name = lhttp.header_attribute(buffer, "name")
+				field.file = lhttp.header_attribute(buffer, "filename")
+				field[1] = field.file
+			end
+
+			if field.headers then
+				field.headers[header] = buffer
+			else
+				field.headers = { [header] = buffer }
+			end
+
+		elseif what == parser.PART_BEGIN then
+			return not field.file
+
+		elseif what == parser.PART_DATA and field.name and length > 0 then
+			if field.file then
+				if file_cb then
+					file_cb(field, buffer, false)
+					msg.params[field.name] = msg.params[field.name] or field
+				else
+					if not field.fd then
+						field.fd = nixio.mkstemp(field.name)
+					end
+
+					if field.fd then
+						field.fd:write(buffer)
+						msg.params[field.name] = msg.params[field.name] or field
+					end
+				end
+			else
+				field.value = buffer
+			end
+
+		elseif what == parser.PART_END and field.name then
+			if field.file and msg.params[field.name] then
+				if file_cb then
+					file_cb(field, "", true)
+				elseif field.fd then
+					field.fd:seek(0, "set")
+				end
+			else
+				local val = msg.params[field.name]
+
+				if type(val) == "table" then
+					val[#val+1] = field.value or ""
+				elseif val ~= nil then
+					msg.params[field.name] = { val, field.value or "" }
+				else
+					msg.params[field.name] = field.value or ""
+				end
+			end
+
+			field = nil
+
+		elseif what == parser.ERROR then
+			err = buffer
+		end
+
+		return true
+	end, HTTP_MAX_CONTENT)
+
+	return ltn12.pump.all(src, function (chunk)
+		len = len + (chunk and #chunk or 0)
+
+		if maxlen and len > maxlen + 2 then
+			return nil, "Message body size exceeds Content-Length"
+		end
+
+		if not parser or not parser:parse(chunk) then
+			return nil, err
+		end
+
+		return true
+	end)
+end
+
+-- Content-Type. Stores all extracted data associated with its parameter name
+-- in the params table within the given message object. Multiple parameter
+-- values are stored as tables, ordinary ones as strings.
+function urldecode_message_body(src, msg)
+	local err, name, value, parser
+	local len, maxlen = 0, tonumber(msg.env.CONTENT_LENGTH or nil)
+
+	parser = lhttp.urlencoded_parser(function (what, buffer, length)
+		if what == parser.TUPLE then
+			name, value = nil, nil
+		elseif what == parser.NAME then
+			name = lhttp.urldecode(buffer, lhttp.DECODE_PLUS)
+		elseif what == parser.VALUE and name then
+			local val = msg.params[name]
+
+			if type(val) == "table" then
+				val[#val+1] = lhttp.urldecode(buffer, lhttp.DECODE_PLUS) or ""
+			elseif val ~= nil then
+				msg.params[name] = { val, lhttp.urldecode(buffer, lhttp.DECODE_PLUS) or "" }
+			else
+				msg.params[name] = lhttp.urldecode(buffer, lhttp.DECODE_PLUS) or ""
+			end
+		elseif what == parser.ERROR then
+			err = buffer
+		end
+
+		return true
+	end, HTTP_MAX_CONTENT)
+
+	return ltn12.pump.all(src, function (chunk)
+		len = len + (chunk and #chunk or 0)
+
+		if maxlen and len > maxlen + 2 then
+			return nil, "Message body size exceeds Content-Length"
+		elseif len > HTTP_MAX_CONTENT then
+			return nil, "Message body size exceeds maximum allowed length"
+		end
+
+		if not parser or not parser:parse(chunk) then
+			return nil, err
+		end
+
+		return true
+	end)
+end
+
+-- This function will examine the Content-Type within the given message object
+-- to select the appropriate content decoder.
+-- Currently the application/x-www-urlencoded and application/form-data
+-- mime types are supported. If the encountered content encoding can't be
+-- handled then the whole message body will be stored unaltered as "content"
+-- property within the given message object.
+function parse_message_body(src, msg, filecb)
+	if msg.env.CONTENT_LENGTH or msg.env.REQUEST_METHOD == "POST" then
+		local ctype = lhttp.header_attribute(msg.env.CONTENT_TYPE, nil)
+
+		-- Is it multipart/mime ?
+		if ctype == "multipart/form-data" then
+			return mimedecode_message_body(src, msg, filecb)
+
+		-- Is it application/x-www-form-urlencoded ?
+		elseif ctype == "application/x-www-form-urlencoded" then
+			return urldecode_message_body(src, msg)
+
+		end
+
+		-- Unhandled encoding
+		-- If a file callback is given then feed it chunk by chunk, else
+		-- store whole buffer in message.content
+		local sink
+
+		-- If we have a file callback then feed it
+		if type(filecb) == "function" then
+			local meta = {
+				name = "raw",
+				encoding = msg.env.CONTENT_TYPE
+			}
+			sink = function( chunk )
+				if chunk then
+					return filecb(meta, chunk, false)
+				else
+					return filecb(meta, nil, true)
+				end
+			end
+		-- ... else append to .content
+		else
+			msg.content = ""
+			msg.content_length = 0
+
+			sink = function( chunk )
+				if chunk then
+					if ( msg.content_length + #chunk ) <= HTTP_MAX_CONTENT then
+						msg.content        = msg.content        .. chunk
+						msg.content_length = msg.content_length + #chunk
+						return true
+					else
+						return nil, "POST data exceeds maximum allowed length"
+					end
+				end
+				return true
+			end
+		end
+
+		-- Pump data...
+		while true do
+			local ok, err = ltn12.pump.step( src, sink )
+
+			if not ok and err then
+				return nil, err
+			elseif not ok then -- eof
+				return true
+			end
+		end
+
+		return true
+	end
+
+	return false
+end
diff --git a/libs/luci-lib-base/luasrc/http.luadoc b/libs/luci-lib-base/luasrc/http.luadoc
new file mode 100644
index 0000000000..8f6f380d8b
--- /dev/null
+++ b/libs/luci-lib-base/luasrc/http.luadoc
@@ -0,0 +1,260 @@
+---[[
+LuCI Web Framework high-level HTTP functions.
+]]
+module "luci.http"
+
+---[[
+Close the HTTP-Connection.
+
+@class			function
+@name			close
+]]
+
+---[[
+Return the request content if the request was of unknown type.
+
+@class			function
+@name			content
+@return			HTTP request body
+@return			HTTP request body length
+]]
+
+---[[
+Get a certain HTTP input value or a table of all input values.
+
+@class			function
+@name			formvalue
+@param name		Name of the GET or POST variable to fetch
+@param noparse	Don't parse POST data before getting the value
+@return			HTTP input value or table of all input value
+]]
+
+---[[
+Get a table of all HTTP input values with a certain prefix.
+
+@class			function
+@name			formvaluetable
+@param prefix	Prefix
+@return			Table of all HTTP input values with given prefix
+]]
+
+---[[
+Get the value of a certain HTTP-Cookie.
+
+@class			function
+@name			getcookie
+@param name		Cookie Name
+@return			String containing cookie data
+]]
+
+---[[
+Get the value of a certain HTTP environment variable
+or the environment table itself.
+
+@class			function
+@name			getenv
+@param name		Environment variable
+@return			HTTP environment value or environment table
+]]
+
+---[[
+Set a handler function for incoming user file uploads.
+
+@class			function
+@name			setfilehandler
+@param callback	Handler function
+]]
+
+---[[
+Send a HTTP-Header.
+
+@class			function
+@name			header
+@param key		Header key
+@param value	Header value
+]]
+
+---[[
+Set the mime type of following content data.
+
+@class			function
+@name			prepare_content
+@param mime		Mimetype of following content
+]]
+
+---[[
+Get the RAW HTTP input source
+
+@class			function
+@name			source
+@return			HTTP LTN12 source
+]]
+
+---[[
+Set the HTTP status code and status message.
+
+@class			function
+@name			status
+@param code		Status code
+@param message	Status message
+]]
+
+---[[
+Send a chunk of content data to the client.
+
+This function is as a valid LTN12 sink.
+If the content chunk is nil this function will automatically invoke close.
+
+@class			function
+@name			write
+@param content	Content chunk
+@param src_err	Error object from source (optional)
+@see close
+]]
+
+---[[
+Splice data from a filedescriptor to the client.
+
+@class			function
+@name			splice
+@param fp		File descriptor
+@param size		Bytes to splice (optional)
+]]
+
+---[[
+Redirects the client to a new URL and closes the connection.
+
+@class			function
+@name			redirect
+@param url		Target URL
+]]
+
+---[[
+Create a querystring out of a table of key - value pairs.
+
+@class			function
+@name			build_querystring
+@param table	Query string source table
+@return			Encoded HTTP query string
+]]
+
+---[[
+Return the URL-decoded equivalent of a string.
+
+@class			function
+@name			urldecode
+@param str		URL-encoded string
+@param no_plus	Don't decode + to " "
+@return			URL-decoded string
+@see			urlencode
+]]
+
+---[[
+Return the URL-encoded equivalent of a string.
+
+@class			function
+@name			urlencode
+@param str		Source string
+@return			URL-encoded string
+@see			urldecode
+]]
+
+---[[
+Send the given data as JSON encoded string.
+
+@class			function
+@name			write_json
+@param data		Data to send
+]]
+
+---[[
+Extract and split urlencoded data pairs, separated bei either "&" or ";"
+from given url or string. Returns a table with urldecoded values.
+
+Simple parameters are stored as string values associated with the parameter
+name within the table. Parameters with multiple values are stored as array
+containing the corresponding values.
+
+@class			function
+@name			urldecode_params
+@param url		The url or string which contains x-www-urlencoded form data
+@param tbl		Use the given table for storing values (optional)
+@return			Table containing the urldecoded parameters
+@see			urlencode_params
+]]
+
+---[[
+Encode each key-value-pair in given table to x-www-urlencoded format,
+separated by "&".
+
+Tables are encoded as parameters with multiple values by repeating the
+parameter name with each value.
+
+@class			function
+@name			urlencode_params
+@param tbl		Table with the values
+@return			String containing encoded values
+@see			urldecode_params
+]]
+
+---[[
+Decode a mime encoded http message body with multipart/form-data Content-Type.
+
+Stores all extracted data associated with its parameter name
+in the params table within the given message object. Multiple parameter
+values are stored as tables, ordinary ones as strings.
+
+If an optional file callback function is given then it is fed with the
+file contents chunk by chunk and only the extracted file name is stored
+within the params table. The callback function will be called subsequently
+with three arguments:
+ o Table containing decoded (name, file) and raw (headers) mime header data
+ o String value containing a chunk of the file data
+ o Boolean which indicates whether the current chunk is the last one (eof)
+
+@class			function
+@name			mimedecode_message_body
+@param src		Ltn12 source function
+@param msg		HTTP message object
+@param filecb	File callback function (optional)
+@return			Value indicating successful operation (not nil means "ok")
+@return			String containing the error if unsuccessful
+@see			parse_message_header
+]]
+
+---[[
+Decode an urlencoded http message body with application/x-www-urlencoded
+Content-Type.
+
+Stores all extracted data associated with its parameter name in the params
+table within the given message object. Multiple parameter values are stored
+as tables, ordinary ones as strings.
+
+@class			function
+@name			urldecode_message_body
+@param src		Ltn12 source function
+@param msg		HTTP message object
+@return			Value indicating successful operation (not nil means "ok")
+@return			String containing the error if unsuccessful
+@see			parse_message_header
+]]
+
+---[[
+Try to extract and decode a http message body from the given ltn12 source.
+This function will examine the Content-Type within the given message object
+to select the appropriate content decoder.
+
+Currently the application/x-www-urlencoded and application/form-data
+mime types are supported. If the encountered content encoding can't be
+handled then the whole message body will be stored unaltered as "content"
+property within the given message object.
+
+@class			function
+@name			parse_message_body
+@param src		Ltn12 source function
+@param msg		HTTP message object
+@param filecb	File data callback (optional, see mimedecode_message_body())
+@return			Value indicating successful operation (not nil means "ok")
+@return			String containing the error if unsuccessful
+@see			parse_message_header
+]]
diff --git a/libs/luci-lib-base/luasrc/ltn12.lua b/libs/luci-lib-base/luasrc/ltn12.lua
new file mode 100644
index 0000000000..3a7268ccae
--- /dev/null
+++ b/libs/luci-lib-base/luasrc/ltn12.lua
@@ -0,0 +1,316 @@
+--[[
+LuaSocket 2.0.2 license
+Copyright � 2004-2007 Diego Nehab
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+]]--
+--[[
+	Changes made by LuCI project:
+		* Renamed to luci.ltn12 to avoid collisions with luasocket
+		* Added inline documentation
+]]--
+-----------------------------------------------------------------------------
+-- LTN12 - Filters, sources, sinks and pumps.
+-- LuaSocket toolkit.
+-- Author: Diego Nehab
+-- RCS ID: $Id$
+-----------------------------------------------------------------------------
+
+-----------------------------------------------------------------------------
+-- Declare module
+-----------------------------------------------------------------------------
+local string = require("string")
+local table = require("table")
+local base = _G
+
+-- See http://lua-users.org/wiki/FiltersSourcesAndSinks for design concepts 
+module("luci.ltn12")
+
+filter = {}
+source = {}
+sink = {}
+pump = {}
+
+-- 2048 seems to be better in windows...
+BLOCKSIZE = 2048
+_VERSION = "LTN12 1.0.1"
+
+-----------------------------------------------------------------------------
+-- Filter stuff
+-----------------------------------------------------------------------------
+
+
+-- by passing it each chunk and updating a context between calls. 
+function filter.cycle(low, ctx, extra)
+    base.assert(low)
+    return function(chunk)
+        local ret
+        ret, ctx = low(ctx, chunk, extra)
+        return ret
+    end
+end
+
+-- (thanks to Wim Couwenberg)
+function filter.chain(...)
+    local n = table.getn(arg)
+    local top, index = 1, 1
+    local retry = ""
+    return function(chunk)
+        retry = chunk and retry
+        while true do
+            if index == top then
+                chunk = arg[index](chunk)
+                if chunk == "" or top == n then return chunk
+                elseif chunk then index = index + 1
+                else
+                    top = top+1
+                    index = top
+                end
+            else
+                chunk = arg[index](chunk or "")
+                if chunk == "" then
+                    index = index - 1
+                    chunk = retry
+                elseif chunk then
+                    if index == n then return chunk
+                    else index = index + 1 end
+                else base.error("filter returned inappropriate nil") end
+            end
+        end
+    end
+end
+
+-----------------------------------------------------------------------------
+-- Source stuff
+-----------------------------------------------------------------------------
+
+
+-- create an empty source
+local function empty()
+    return nil
+end
+
+function source.empty()
+    return empty
+end
+
+function source.error(err)
+    return function()
+        return nil, err
+    end
+end
+
+function source.file(handle, io_err)
+    if handle then
+        return function()
+            local chunk = handle:read(BLOCKSIZE)
+            if chunk and chunk:len() == 0 then chunk = nil end
+            if not chunk then handle:close() end
+            return chunk
+        end
+    else return source.error(io_err or "unable to open file") end
+end
+
+function source.simplify(src)
+    base.assert(src)
+    return function()
+        local chunk, err_or_new = src()
+        src = err_or_new or src
+        if not chunk then return nil, err_or_new
+        else return chunk end
+    end
+end
+
+function source.string(s)
+    if s then
+        local i = 1
+        return function()
+            local chunk = string.sub(s, i, i+BLOCKSIZE-1)
+            i = i + BLOCKSIZE
+            if chunk ~= "" then return chunk
+            else return nil end
+        end
+    else return source.empty() end
+end
+
+function source.rewind(src)
+    base.assert(src)
+    local t = {}
+    return function(chunk)
+        if not chunk then
+            chunk = table.remove(t)
+            if not chunk then return src()
+            else return chunk end
+        else
+            t[#t+1] = chunk
+        end
+    end
+end
+
+function source.chain(src, f)
+    base.assert(src and f)
+    local last_in, last_out = "", ""
+    local state = "feeding"
+    local err
+    return function()
+        if not last_out then
+            base.error('source is empty!', 2)
+        end
+        while true do
+            if state == "feeding" then
+                last_in, err = src()
+                if err then return nil, err end
+                last_out = f(last_in)
+                if not last_out then
+                    if last_in then
+                        base.error('filter returned inappropriate nil')
+                    else
+                        return nil
+                    end
+                elseif last_out ~= "" then
+                    state = "eating"
+                    if last_in then last_in = "" end
+                    return last_out
+                end
+            else
+                last_out = f(last_in)
+                if last_out == "" then
+                    if last_in == "" then
+                        state = "feeding"
+                    else
+                        base.error('filter returned ""')
+                    end
+                elseif not last_out then
+                    if last_in then
+                        base.error('filter returned inappropriate nil')
+                    else
+                        return nil
+                    end
+                else
+                    return last_out
+                end
+            end
+        end
+    end
+end
+
+-- Sources will be used one after the other, as if they were concatenated
+-- (thanks to Wim Couwenberg)
+function source.cat(...)
+    local src = table.remove(arg, 1)
+    return function()
+        while src do
+            local chunk, err = src()
+            if chunk then return chunk end
+            if err then return nil, err end
+            src = table.remove(arg, 1)
+        end
+    end
+end
+
+-----------------------------------------------------------------------------
+-- Sink stuff
+-----------------------------------------------------------------------------
+
+
+function sink.table(t)
+    t = t or {}
+    local f = function(chunk, err)
+        if chunk then t[#t+1] = chunk end
+        return 1
+    end
+    return f, t
+end
+
+function sink.simplify(snk)
+    base.assert(snk)
+    return function(chunk, err)
+        local ret, err_or_new = snk(chunk, err)
+        if not ret then return nil, err_or_new end
+        snk = err_or_new or snk
+        return 1
+    end
+end
+
+function sink.file(handle, io_err)
+    if handle then
+        return function(chunk, err)
+            if not chunk then
+                handle:close()
+                return 1
+            else return handle:write(chunk) end
+        end
+    else return sink.error(io_err or "unable to open file") end
+end
+
+-- creates a sink that discards data
+local function null()
+    return 1
+end
+
+function sink.null()
+    return null
+end
+
+function sink.error(err)
+    return function()
+        return nil, err
+    end
+end
+
+function sink.chain(f, snk)
+    base.assert(f and snk)
+    return function(chunk, err)
+        if chunk ~= "" then
+            local filtered = f(chunk)
+            local done = chunk and ""
+            while true do
+                local ret, snkerr = snk(filtered, err)
+                if not ret then return nil, snkerr end
+                if filtered == done then return 1 end
+                filtered = f(done)
+            end
+        else return 1 end
+    end
+end
+
+-----------------------------------------------------------------------------
+-- Pump stuff
+-----------------------------------------------------------------------------
+
+
+function pump.step(src, snk)
+    local chunk, src_err = src()
+    local ret, snk_err = snk(chunk, src_err)
+    if chunk and ret then return 1
+    else return nil, src_err or snk_err end
+end
+
+function pump.all(src, snk, step)
+    base.assert(src and snk)
+    step = step or pump.step
+    while true do
+        local ret, err = step(src, snk)
+        if not ret then
+            if err then return nil, err
+            else return 1 end
+        end
+    end
+end
+
diff --git a/libs/luci-lib-base/luasrc/util.lua b/libs/luci-lib-base/luasrc/util.lua
new file mode 100644
index 0000000000..a30e8b72f3
--- /dev/null
+++ b/libs/luci-lib-base/luasrc/util.lua
@@ -0,0 +1,776 @@
+-- Copyright 2008 Steven Barth <steven@midlink.org>
+-- Licensed to the public under the Apache License 2.0.
+
+local io = require "io"
+local math = require "math"
+local table = require "table"
+local debug = require "debug"
+local ldebug = require "luci.debug"
+local string = require "string"
+local coroutine = require "coroutine"
+local tparser = require "luci.template.parser"
+local json = require "luci.jsonc"
+local lhttp = require "lucihttp"
+
+local _ubus = require "ubus"
+local _ubus_connection = nil
+
+local getmetatable, setmetatable = getmetatable, setmetatable
+local rawget, rawset, unpack, select = rawget, rawset, unpack, select
+local tostring, type, assert, error = tostring, type, assert, error
+local ipairs, pairs, next, loadstring = ipairs, pairs, next, loadstring
+local require, pcall, xpcall = require, pcall, xpcall
+local collectgarbage, get_memory_limit = collectgarbage, get_memory_limit
+
+module "luci.util"
+
+--
+-- Pythonic string formatting extension
+--
+getmetatable("").__mod = function(a, b)
+	local ok, res
+
+	if not b then
+		return a
+	elseif type(b) == "table" then
+		local k, _
+		for k, _ in pairs(b) do if type(b[k]) == "userdata" then b[k] = tostring(b[k]) end end
+
+		ok, res = pcall(a.format, a, unpack(b))
+		if not ok then
+			error(res, 2)
+		end
+		return res
+	else
+		if type(b) == "userdata" then b = tostring(b) end
+
+		ok, res = pcall(a.format, a, b)
+		if not ok then
+			error(res, 2)
+		end
+		return res
+	end
+end
+
+
+--
+-- Class helper routines
+--
+
+-- Instantiates a class
+local function _instantiate(class, ...)
+	local inst = setmetatable({}, {__index = class})
+
+	if inst.__init__ then
+		inst:__init__(...)
+	end
+
+	return inst
+end
+
+-- The class object can be instantiated by calling itself.
+-- Any class functions or shared parameters can be attached to this object.
+-- Attaching a table to the class object makes this table shared between
+-- all instances of this class. For object parameters use the __init__ function.
+-- Classes can inherit member functions and values from a base class.
+-- Class can be instantiated by calling them. All parameters will be passed
+-- to the __init__ function of this class - if such a function exists.
+-- The __init__ function must be used to set any object parameters that are not shared
+-- with other objects of this class. Any return values will be ignored.
+function class(base)
+	return setmetatable({}, {
+		__call  = _instantiate,
+		__index = base
+	})
+end
+
+function instanceof(object, class)
+	local meta = getmetatable(object)
+	while meta and meta.__index do
+		if meta.__index == class then
+			return true
+		end
+		meta = getmetatable(meta.__index)
+	end
+	return false
+end
+
+
+--
+-- Scope manipulation routines
+--
+
+coxpt = setmetatable({}, { __mode = "kv" })
+
+local tl_meta = {
+	__mode = "k",
+
+	__index = function(self, key)
+		local t = rawget(self, coxpt[coroutine.running()]
+		 or coroutine.running() or 0)
+		return t and t[key]
+	end,
+
+	__newindex = function(self, key, value)
+		local c = coxpt[coroutine.running()] or coroutine.running() or 0
+		local r = rawget(self, c)
+		if not r then
+			rawset(self, c, { [key] = value })
+		else
+			r[key] = value
+		end
+	end
+}
+
+-- the current active coroutine. A thread local store is private a table object
+-- whose values can't be accessed from outside of the running coroutine.
+function threadlocal(tbl)
+	return setmetatable(tbl or {}, tl_meta)
+end
+
+
+--
+-- Debugging routines
+--
+
+function perror(obj)
+	return io.stderr:write(tostring(obj) .. "\n")
+end
+
+function dumptable(t, maxdepth, i, seen)
+	i = i or 0
+	seen = seen or setmetatable({}, {__mode="k"})
+
+	for k,v in pairs(t) do
+		perror(string.rep("\t", i) .. tostring(k) .. "\t" .. tostring(v))
+		if type(v) == "table" and (not maxdepth or i < maxdepth) then
+			if not seen[v] then
+				seen[v] = true
+				dumptable(v, maxdepth, i+1, seen)
+			else
+				perror(string.rep("\t", i) .. "*** RECURSION ***")
+			end
+		end
+	end
+end
+
+
+--
+-- String and data manipulation routines
+--
+
+function pcdata(value)
+	return value and tparser.pcdata(tostring(value))
+end
+
+function urlencode(value)
+	if value ~= nil then
+		local str = tostring(value)
+		return lhttp.urlencode(str, lhttp.ENCODE_IF_NEEDED + lhttp.ENCODE_FULL)
+			or str
+	end
+	return nil
+end
+
+function urldecode(value, decode_plus)
+	if value ~= nil then
+		local flag = decode_plus and lhttp.DECODE_PLUS or 0
+		local str = tostring(value)
+		return lhttp.urldecode(str, lhttp.DECODE_IF_NEEDED + flag)
+			or str
+	end
+	return nil
+end
+
+function striptags(value)
+	return value and tparser.striptags(tostring(value))
+end
+
+function shellquote(value)
+	return string.format("'%s'", string.gsub(value or "", "'", "'\\''"))
+end
+
+-- for bash, ash and similar shells single-quoted strings are taken
+-- literally except for single quotes (which terminate the string)
+-- (and the exception noted below for dash (-) at the start of a
+-- command line parameter).
+function shellsqescape(value)
+   local res
+   res, _ = string.gsub(value, "'", "'\\''")
+   return res
+end
+
+-- bash, ash and other similar shells interpret a dash (-) at the start
+-- of a command-line parameters as an option indicator regardless of
+-- whether it is inside a single-quoted string.  It must be backlash
+-- escaped to resolve this.  This requires in some funky special-case
+-- handling.  It may actually be a property of the getopt function
+-- rather than the shell proper.
+function shellstartsqescape(value)
+   res, _ = string.gsub(value, "^%-", "\\-")
+   return shellsqescape(res)
+end
+
+-- containing the resulting substrings. The optional max parameter specifies
+-- the number of bytes to process, regardless of the actual length of the given
+-- string. The optional last parameter, regex, specifies whether the separator
+-- sequence is interpreted as regular expression.
+--					pattern as regular expression (optional, default is false)
+function split(str, pat, max, regex)
+	pat = pat or "\n"
+	max = max or #str
+
+	local t = {}
+	local c = 1
+
+	if #str == 0 then
+		return {""}
+	end
+
+	if #pat == 0 then
+		return nil
+	end
+
+	if max == 0 then
+		return str
+	end
+
+	repeat
+		local s, e = str:find(pat, c, not regex)
+		max = max - 1
+		if s and max < 0 then
+			t[#t+1] = str:sub(c)
+		else
+			t[#t+1] = str:sub(c, s and s - 1)
+		end
+		c = e and e + 1 or #str + 1
+	until not s or max < 0
+
+	return t
+end
+
+function trim(str)
+	return (str:gsub("^%s*(.-)%s*$", "%1"))
+end
+
+function cmatch(str, pat)
+	local count = 0
+	for _ in str:gmatch(pat) do count = count + 1 end
+	return count
+end
+
+-- one token per invocation, the tokens are separated by whitespace. If the
+-- input value is a table, it is transformed into a string first. A nil value
+-- will result in a valid iterator which aborts with the first invocation.
+function imatch(v)
+	if type(v) == "table" then
+		local k = nil
+		return function()
+			k = next(v, k)
+			return v[k]
+		end
+
+	elseif type(v) == "number" or type(v) == "boolean" then
+		local x = true
+		return function()
+			if x then
+				x = false
+				return tostring(v)
+			end
+		end
+
+	elseif type(v) == "userdata" or type(v) == "string" then
+		return tostring(v):gmatch("%S+")
+	end
+
+	return function() end
+end
+
+-- value or 0 if the unit is unknown. Upper- or lower case is irrelevant.
+-- Recognized units are:
+--	o "y"	- one year   (60*60*24*366)
+--  o "m"	- one month  (60*60*24*31)
+--  o "w"	- one week   (60*60*24*7)
+--  o "d"	- one day    (60*60*24)
+--  o "h"	- one hour	 (60*60)
+--  o "min"	- one minute (60)
+--  o "kb"  - one kilobyte (1024)
+--  o "mb"	- one megabyte (1024*1024)
+--  o "gb"	- one gigabyte (1024*1024*1024)
+--  o "kib" - one si kilobyte (1000)
+--  o "mib"	- one si megabyte (1000*1000)
+--  o "gib"	- one si gigabyte (1000*1000*1000)
+function parse_units(ustr)
+
+	local val = 0
+
+	-- unit map
+	local map = {
+		-- date stuff
+		y   = 60 * 60 * 24 * 366,
+		m   = 60 * 60 * 24 * 31,
+		w   = 60 * 60 * 24 * 7,
+		d   = 60 * 60 * 24,
+		h   = 60 * 60,
+		min = 60,
+
+		-- storage sizes
+		kb  = 1024,
+		mb  = 1024 * 1024,
+		gb  = 1024 * 1024 * 1024,
+
+		-- storage sizes (si)
+		kib = 1000,
+		mib = 1000 * 1000,
+		gib = 1000 * 1000 * 1000
+	}
+
+	-- parse input string
+	for spec in ustr:lower():gmatch("[0-9%.]+[a-zA-Z]*") do
+
+		local num = spec:gsub("[^0-9%.]+$","")
+		local spn = spec:gsub("^[0-9%.]+", "")
+
+		if map[spn] or map[spn:sub(1,1)] then
+			val = val + num * ( map[spn] or map[spn:sub(1,1)] )
+		else
+			val = val + num
+		end
+	end
+
+
+	return val
+end
+
+-- also register functions above in the central string class for convenience
+string.pcdata      = pcdata
+string.striptags   = striptags
+string.split       = split
+string.trim        = trim
+string.cmatch      = cmatch
+string.parse_units = parse_units
+
+
+function append(src, ...)
+	for i, a in ipairs({...}) do
+		if type(a) == "table" then
+			for j, v in ipairs(a) do
+				src[#src+1] = v
+			end
+		else
+			src[#src+1] = a
+		end
+	end
+	return src
+end
+
+function combine(...)
+	return append({}, ...)
+end
+
+function contains(table, value)
+	for k, v in pairs(table) do
+		if value == v then
+			return k
+		end
+	end
+	return false
+end
+
+-- Both table are - in fact - merged together.
+function update(t, updates)
+	for k, v in pairs(updates) do
+		t[k] = v
+	end
+end
+
+function keys(t)
+	local keys = { }
+	if t then
+		for k, _ in kspairs(t) do
+			keys[#keys+1] = k
+		end
+	end
+	return keys
+end
+
+function clone(object, deep)
+	local copy = {}
+
+	for k, v in pairs(object) do
+		if deep and type(v) == "table" then
+			v = clone(v, deep)
+		end
+		copy[k] = v
+	end
+
+	return setmetatable(copy, getmetatable(object))
+end
+
+
+-- Serialize the contents of a table value.
+function _serialize_table(t, seen)
+	assert(not seen[t], "Recursion detected.")
+	seen[t] = true
+
+	local data  = ""
+	local idata = ""
+	local ilen  = 0
+
+	for k, v in pairs(t) do
+		if type(k) ~= "number" or k < 1 or math.floor(k) ~= k or ( k - #t ) > 3 then
+			k = serialize_data(k, seen)
+			v = serialize_data(v, seen)
+			data = data .. ( #data > 0 and ", " or "" ) ..
+				'[' .. k .. '] = ' .. v
+		elseif k > ilen then
+			ilen = k
+		end
+	end
+
+	for i = 1, ilen do
+		local v = serialize_data(t[i], seen)
+		idata = idata .. ( #idata > 0 and ", " or "" ) .. v
+	end
+
+	return idata .. ( #data > 0 and #idata > 0 and ", " or "" ) .. data
+end
+
+-- with loadstring().
+function serialize_data(val, seen)
+	seen = seen or setmetatable({}, {__mode="k"})
+
+	if val == nil then
+		return "nil"
+	elseif type(val) == "number" then
+		return val
+	elseif type(val) == "string" then
+		return "%q" % val
+	elseif type(val) == "boolean" then
+		return val and "true" or "false"
+	elseif type(val) == "function" then
+		return "loadstring(%q)" % get_bytecode(val)
+	elseif type(val) == "table" then
+		return "{ " .. _serialize_table(val, seen) .. " }"
+	else
+		return '"[unhandled data type:' .. type(val) .. ']"'
+	end
+end
+
+function restore_data(str)
+	return loadstring("return " .. str)()
+end
+
+
+--
+-- Byte code manipulation routines
+--
+
+-- will be stripped before it is returned.
+function get_bytecode(val)
+	local code
+
+	if type(val) == "function" then
+		code = string.dump(val)
+	else
+		code = string.dump( loadstring( "return " .. serialize_data(val) ) )
+	end
+
+	return code -- and strip_bytecode(code)
+end
+
+-- numbers and debugging numbers will be discarded. Original version by
+-- Peter Cawley (http://lua-users.org/lists/lua-l/2008-02/msg01158.html)
+function strip_bytecode(code)
+	local version, format, endian, int, size, ins, num, lnum = code:byte(5, 12)
+	local subint
+	if endian == 1 then
+		subint = function(code, i, l)
+			local val = 0
+			for n = l, 1, -1 do
+				val = val * 256 + code:byte(i + n - 1)
+			end
+			return val, i + l
+		end
+	else
+		subint = function(code, i, l)
+			local val = 0
+			for n = 1, l, 1 do
+				val = val * 256 + code:byte(i + n - 1)
+			end
+			return val, i + l
+		end
+	end
+
+	local function strip_function(code)
+		local count, offset = subint(code, 1, size)
+		local stripped = { string.rep("\0", size) }
+		local dirty = offset + count
+		offset = offset + count + int * 2 + 4
+		offset = offset + int + subint(code, offset, int) * ins
+		count, offset = subint(code, offset, int)
+		for n = 1, count do
+			local t
+			t, offset = subint(code, offset, 1)
+			if t == 1 then
+				offset = offset + 1
+			elseif t == 4 then
+				offset = offset + size + subint(code, offset, size)
+			elseif t == 3 then
+				offset = offset + num
+			elseif t == 254 or t == 9 then
+				offset = offset + lnum
+			end
+		end
+		count, offset = subint(code, offset, int)
+		stripped[#stripped+1] = code:sub(dirty, offset - 1)
+		for n = 1, count do
+			local proto, off = strip_function(code:sub(offset, -1))
+			stripped[#stripped+1] = proto
+			offset = offset + off - 1
+		end
+		offset = offset + subint(code, offset, int) * int + int
+		count, offset = subint(code, offset, int)
+		for n = 1, count do
+			offset = offset + subint(code, offset, size) + size + int * 2
+		end
+		count, offset = subint(code, offset, int)
+		for n = 1, count do
+			offset = offset + subint(code, offset, size) + size
+		end
+		stripped[#stripped+1] = string.rep("\0", int * 3)
+		return table.concat(stripped), offset
+	end
+
+	return code:sub(1,12) .. strip_function(code:sub(13,-1))
+end
+
+
+--
+-- Sorting iterator functions
+--
+
+function _sortiter( t, f )
+	local keys = { }
+
+	local k, v
+	for k, v in pairs(t) do
+		keys[#keys+1] = k
+	end
+
+	local _pos = 0
+
+	table.sort( keys, f )
+
+	return function()
+		_pos = _pos + 1
+		if _pos <= #keys then
+			return keys[_pos], t[keys[_pos]], _pos
+		end
+	end
+end
+
+-- the provided callback function.
+function spairs(t,f)
+	return _sortiter( t, f )
+end
+
+-- The table pairs are sorted by key.
+function kspairs(t)
+	return _sortiter( t )
+end
+
+-- The table pairs are sorted by value.
+function vspairs(t)
+	return _sortiter( t, function (a,b) return t[a] < t[b] end )
+end
+
+
+--
+-- System utility functions
+--
+
+function bigendian()
+	return string.byte(string.dump(function() end), 7) == 0
+end
+
+function exec(command)
+	local pp   = io.popen(command)
+	local data = pp:read("*a")
+	pp:close()
+
+	return data
+end
+
+function execi(command)
+	local pp = io.popen(command)
+
+	return pp and function()
+		local line = pp:read()
+
+		if not line then
+			pp:close()
+		end
+
+		return line
+	end
+end
+
+-- Deprecated
+function execl(command)
+	local pp   = io.popen(command)
+	local line = ""
+	local data = {}
+
+	while true do
+		line = pp:read()
+		if (line == nil) then break end
+		data[#data+1] = line
+	end
+	pp:close()
+
+	return data
+end
+
+
+local ubus_codes = {
+	"INVALID_COMMAND",
+	"INVALID_ARGUMENT",
+	"METHOD_NOT_FOUND",
+	"NOT_FOUND",
+	"NO_DATA",
+	"PERMISSION_DENIED",
+	"TIMEOUT",
+	"NOT_SUPPORTED",
+	"UNKNOWN_ERROR",
+	"CONNECTION_FAILED"
+}
+
+local function ubus_return(...)
+	if select('#', ...) == 2 then
+		local rv, err = select(1, ...), select(2, ...)
+		if rv == nil and type(err) == "number" then
+			return nil, err, ubus_codes[err]
+		end
+	end
+
+	return ...
+end
+
+function ubus(object, method, data)
+	if not _ubus_connection then
+		_ubus_connection = _ubus.connect()
+		assert(_ubus_connection, "Unable to establish ubus connection")
+	end
+
+	if object and method then
+		if type(data) ~= "table" then
+			data = { }
+		end
+		return ubus_return(_ubus_connection:call(object, method, data))
+	elseif object then
+		return _ubus_connection:signatures(object)
+	else
+		return _ubus_connection:objects()
+	end
+end
+
+function serialize_json(x, cb)
+	local js = json.stringify(x)
+	if type(cb) == "function" then
+		cb(js)
+	else
+		return js
+	end
+end
+
+
+function libpath()
+	return require "nixio.fs".dirname(ldebug.__file__)
+end
+
+function checklib(fullpathexe, wantedlib)
+	local fs = require "nixio.fs"
+	local haveldd = fs.access('/usr/bin/ldd')
+	local haveexe = fs.access(fullpathexe)
+	if not haveldd or not haveexe then
+		return false
+	end
+	local libs = exec(string.format("/usr/bin/ldd %s", shellquote(fullpathexe)))
+	if not libs then
+		return false
+	end
+	for k, v in ipairs(split(libs)) do
+		if v:find(wantedlib) then
+			return true
+		end
+	end
+	return false
+end
+
+-------------------------------------------------------------------------------
+-- Coroutine safe xpcall and pcall versions
+--
+-- Encapsulates the protected calls with a coroutine based loop, so errors can
+-- be dealed without the usual Lua 5.x pcall/xpcall issues with coroutines
+-- yielding inside the call to pcall or xpcall.
+--
+-- Authors: Roberto Ierusalimschy and Andre Carregal
+-- Contributors: Thomas Harning Jr., Ignacio Burgueño, Fabio Mascarenhas
+--
+-- Copyright 2005 - Kepler Project
+--
+-- $Id: coxpcall.lua,v 1.13 2008/05/19 19:20:02 mascarenhas Exp $
+-------------------------------------------------------------------------------
+
+-------------------------------------------------------------------------------
+-- Implements xpcall with coroutines
+-------------------------------------------------------------------------------
+local coromap = setmetatable({}, { __mode = "k" })
+
+local function handleReturnValue(err, co, status, ...)
+	if not status then
+		return false, err(debug.traceback(co, (...)), ...)
+	end
+	if coroutine.status(co) == 'suspended' then
+		return performResume(err, co, coroutine.yield(...))
+	else
+		return true, ...
+	end
+end
+
+function performResume(err, co, ...)
+	return handleReturnValue(err, co, coroutine.resume(co, ...))
+end
+
+local function id(trace, ...)
+	return trace
+end
+
+function coxpcall(f, err, ...)
+	local current = coroutine.running()
+	if not current then
+		if err == id then
+			return pcall(f, ...)
+		else
+			if select("#", ...) > 0 then
+				local oldf, params = f, { ... }
+				f = function() return oldf(unpack(params)) end
+			end
+			return xpcall(f, err)
+		end
+	else
+		local res, co = pcall(coroutine.create, f)
+		if not res then
+			local newf = function(...) return f(...) end
+			co = coroutine.create(newf)
+		end
+		coromap[co] = current
+		coxpt[co] = coxpt[current] or current or 0
+		return performResume(err, co, ...)
+	end
+end
+
+function copcall(f, ...)
+	return coxpcall(f, id, ...)
+end
diff --git a/libs/luci-lib-base/luasrc/util.luadoc b/libs/luci-lib-base/luasrc/util.luadoc
new file mode 100644
index 0000000000..4ec68dd1ef
--- /dev/null
+++ b/libs/luci-lib-base/luasrc/util.luadoc
@@ -0,0 +1,413 @@
+---[[
+LuCI utility functions.
+]]
+module "luci.util"
+
+---[[
+Create a Class object (Python-style object model).
+
+The class object can be instantiated by calling itself.
+Any class functions or shared parameters can be attached to this object.
+Attaching a table to the class object makes this table shared between
+all instances of this class. For object parameters use the __init__ function.
+Classes can inherit member functions and values from a base class.
+Class can be instantiated by calling them. All parameters will be passed
+to the __init__ function of this class - if such a function exists.
+The __init__ function must be used to set any object parameters that are not shared
+with other objects of this class. Any return values will be ignored.
+
+@class				function
+@name				class
+@param base			The base class to inherit from (optional)
+@return				A class object
+@see				instanceof
+@see				clone
+]]
+
+---[[
+Test whether the given object is an instance of the given class.
+
+@class				function
+@name				instanceof
+@param object		Object instance
+@param class		Class object to test against
+@return				Boolean indicating whether the object is an instance
+@see				class
+@see				clone
+]]
+
+---[[
+Create a new or get an already existing thread local store associated with
+the current active coroutine.
+
+A thread local store is private a table object
+whose values can't be accessed from outside of the running coroutine.
+
+@class				function
+@name				threadlocal
+@return				Table value representing the corresponding thread local store
+]]
+
+---[[
+Write given object to stderr.
+
+@class				function
+@name				perror
+@param obj			Value to write to stderr
+@return				Boolean indicating whether the write operation was successful
+]]
+
+---[[
+Recursively dumps a table to stdout, useful for testing and debugging.
+
+@class				function
+@name				dumptable
+@param t			Table value to dump
+@param maxdepth		Maximum depth
+@return				Always nil
+]]
+
+---[[
+Create valid XML PCDATA from given string.
+
+@class				function
+@name				pcdata
+@param value		String value containing the data to escape
+@return				String value containing the escaped data
+]]
+
+---[[
+Decode an URL-encoded string - optionally decoding the "+" sign to space.
+
+@class				function
+@name				urldecode
+@param str			Input string in x-www-urlencoded format
+@param decode_plus	Decode "+" signs to spaces if true (optional)
+@return				The decoded string
+@see				urlencode
+]]
+
+---[[
+URL-encode given string.
+
+@class				function
+@name				urlencode
+@param str			String to encode
+@return				String containing the encoded data
+@see				urldecode
+]]
+
+---[[
+Strip HTML tags from given string.
+
+@class				function
+@name				striptags
+@param value		String containing the HTML text
+@return				String with HTML tags stripped of
+]]
+
+---[[
+Safely quote value for use in shell commands.
+
+@class				function
+@name				shellquote
+@param value		String containing the value to quote
+@return 			Single-quote enclosed string with embedded quotes escaped
+]]
+
+---[[
+Splits given string on a defined separator sequence and return a table
+containing the resulting substrings.
+
+The optional max parameter specifies the number of bytes to process,
+regardless of the actual length of the given string. The optional last
+parameter, regex, specifies whether the separator sequence is
+nterpreted as regular expression.
+
+@class				function
+@name				split
+@param str			String value containing the data to split up
+@param pat			String with separator pattern (optional, defaults to "\n")
+@param max			Maximum times to split (optional)
+@param regex		Boolean indicating whether to interpret the separator
+--					pattern as regular expression (optional, default is false)
+@return				Table containing the resulting substrings
+]]
+
+---[[
+Remove leading and trailing whitespace from given string value.
+
+@class				function
+@name				trim
+@param str			String value containing whitespace padded data
+@return				String value with leading and trailing space removed
+]]
+
+---[[
+Count the occurrences of given substring in given string.
+
+@class				function
+@name				cmatch
+@param str			String to search in
+@param pattern		String containing pattern to find
+@return				Number of found occurrences
+]]
+
+---[[
+Return a matching iterator for the given value.
+
+The iterator will return one token per invocation, the tokens are separated by
+whitespace. If the input value is a table, it is transformed into a string first.
+A nil value will result in a valid iterator which aborts with the first invocation.
+
+@class				function
+@name				imatch
+@param val			The value to scan (table, string or nil)
+@return				Iterator which returns one token per call
+]]
+
+---[[
+Parse certain units from the given string and return the canonical integer
+value or 0 if the unit is unknown.
+
+Upper- or lower case is irrelevant.
+Recognized units are:
+
+--	o "y"	- one year   (60*60*24*366)
+ o "m"	- one month  (60*60*24*31)
+ o "w"	- one week   (60*60*24*7)
+ o "d"	- one day    (60*60*24)
+ o "h"	- one hour	 (60*60)
+ o "min"	- one minute (60)
+ o "kb"  - one kilobyte (1024)
+ o "mb"	- one megabyte (1024*1024)
+ o "gb"	- one gigabyte (1024*1024*1024)
+ o "kib" - one si kilobyte (1000)
+ o "mib"	- one si megabyte (1000*1000)
+ o "gib"	- one si gigabyte (1000*1000*1000)
+
+@class				function
+@name				parse_units
+@param ustr			String containing a numerical value with trailing unit
+@return				Number containing the canonical value
+]]
+
+---[[
+Appends numerically indexed tables or single objects to a given table.
+
+@class				function
+@name				append
+@param src			Target table
+@param ...			Objects to insert
+@return				Target table
+]]
+
+---[[
+Combines two or more numerically indexed tables and single objects into one table.
+
+@class				function
+@name				combine
+@param tbl1			Table value to combine
+@param tbl2			Table value to combine
+@param ...			More tables to combine
+@return				Table value containing all values of given tables
+]]
+
+---[[
+Checks whether the given table contains the given value.
+
+@class				function
+@name				contains
+@param table		Table value
+@param value		Value to search within the given table
+@return				Number indicating the first index at which the given value occurs
+--					within table or false.
+]]
+
+---[[
+Update values in given table with the values from the second given table.
+
+Both table are - in fact - merged together.
+
+@class				function
+@name				update
+@param t			Table which should be updated
+@param updates		Table containing the values to update
+@return				Always nil
+]]
+
+---[[
+Retrieve all keys of given associative table.
+
+@class				function
+@name				keys
+@param t			Table to extract keys from
+@return				Sorted table containing the keys
+]]
+
+---[[
+Clones the given object and return it's copy.
+
+@class				function
+@name				clone
+@param object		Table value to clone
+@param deep			Boolean indicating whether to do recursive cloning
+@return				Cloned table value
+]]
+
+---[[
+Recursively serialize given data to lua code, suitable for restoring
+with loadstring().
+
+@class				function
+@name				serialize_data
+@param val			Value containing the data to serialize
+@return				String value containing the serialized code
+@see				restore_data
+@see				get_bytecode
+]]
+
+---[[
+Restore data previously serialized with serialize_data().
+
+@class				function
+@name				restore_data
+@param str			String containing the data to restore
+@return				Value containing the restored data structure
+@see				serialize_data
+@see				get_bytecode
+]]
+
+---[[
+Return the current runtime bytecode of the given data. The byte code
+will be stripped before it is returned.
+
+@class				function
+@name				get_bytecode
+@param val			Value to return as bytecode
+@return				String value containing the bytecode of the given data
+]]
+
+---[[
+Strips unnecessary lua bytecode from given string.
+
+Information like line numbers and debugging numbers will be discarded.
+Original version by Peter Cawley (http://lua-users.org/lists/lua-l/2008-02/msg01158.html)
+
+@class				function
+@name				strip_bytecode
+@param code			String value containing the original lua byte code
+@return				String value containing the stripped lua byte code
+]]
+
+---[[
+Return a key, value iterator which returns the values sorted according to
+the provided callback function.
+
+@class				function
+@name				spairs
+@param t			The table to iterate
+@param f 			A callback function to decide the order of elements
+@return				Function value containing the corresponding iterator
+]]
+
+---[[
+Return a key, value iterator for the given table.
+
+The table pairs are sorted by key.
+
+@class				function
+@name				kspairs
+@param t			The table to iterate
+@return				Function value containing the corresponding iterator
+]]
+
+---[[
+Return a key, value iterator for the given table.
+
+The table pairs are sorted by value.
+
+@class				function
+@name				vspairs
+@param t			The table to iterate
+@return				Function value containing the corresponding iterator
+]]
+
+---[[
+Test whether the current system is operating in big endian mode.
+
+@class				function
+@name				bigendian
+@return				Boolean value indicating whether system is big endian
+]]
+
+---[[
+Execute given commandline and gather stdout.
+
+@class				function
+@name				exec
+@param command		String containing command to execute
+@return				String containing the command's stdout
+]]
+
+---[[
+Return a line-buffered iterator over the output of given command.
+
+@class				function
+@name				execi
+@param command		String containing the command to execute
+@return				Iterator
+]]
+
+---[[
+Issue an ubus call.
+
+@class				function
+@name				ubus
+@param object		String containing the ubus object to call
+@param method		String containing the ubus method to call
+@param values		Table containing the values to pass
+@return				Table containin the ubus result
+]]
+
+---[[
+Convert data structure to JSON
+
+@class				function
+@name				serialize_json
+@param data			The data to serialize
+@param writer		A function to write a chunk of JSON data (optional)
+@return				String containing the JSON if called without write callback
+]]
+
+---[[
+Returns the absolute path to LuCI base directory.
+
+@class				function
+@name				libpath
+@return				String containing the directory path
+]]
+
+---[[
+This is a coroutine-safe drop-in replacement for Lua's "xpcall"-function
+
+@class				function
+@name				coxpcall
+@param f			Lua function to be called protected
+@param err			Custom error handler
+@param ...			Parameters passed to the function
+@return				A boolean whether the function call succeeded and the return
+--					values of either the function or the error handler
+]]
+
+---[[
+This is a coroutine-safe drop-in replacement for Lua's "pcall"-function
+
+@class				function
+@name				copcall
+@param f			Lua function to be called protected
+@param ...			Parameters passed to the function
+@return				A boolean whether the function call succeeded and the returns
+--					values of the function or the error object
+]]
+