Add a plugin for Network UPS Tools

plugins/nut.lua

@@ -0,0 +1,83 @@
+--
+-- nut.lua: Network UPS Tools service detection plugin
+--
+-- Copyright (c) 2017, Přemysl Janouch <p.janouch@gmail.com>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+ponymap.check_api_version (1)
+
+local NUT = {}
+NUT.__index = NUT
+
+function NUT.new (unit)
+	unit:write ("LIST UPS\n")
+	return setmetatable ({ unit = unit, buf = "", in_list = false }, NUT)
+end
+
+-- Bare words and quoted strings with escape sequences, separated by spaces;
+-- unfortunately Lua patterns are too weak to use them for this trivial task
+function NUT.parse (line)
+	local result, state, field, c = {}, 0, ""
+	for c in (line .. " "):gmatch (".") do
+		if state == 0 then
+			if c == "\"" then state = 2
+			elseif c ~= " "  then field = c state = 1 end
+		elseif state == 1 then
+			if c == " " then table.insert (result, field) field = "" state = 0
+			elseif c == "\"" then state = 2
+			else field = field .. c end
+		elseif state == 2 then
+			if c == "\\" then state = 3
+			elseif c == "\"" then state = 1
+			else field = field .. c end
+		elseif state == 3 then field = field .. c state = 2 end
+	end
+	return result
+end
+
+function NUT:process (line)
+	if not self.in_list then
+		if line:match ("^BEGIN LIST UPS$") then
+			self.unit:add_info ("no authentication required")
+			self.unit:set_success (true)
+			self.in_list = true
+			return true
+		elseif line:match ("^ERR ACCESS-DENIED") then
+			self.unit:set_success (true)
+		end
+	else
+		local fields = self.parse (line)
+		if #fields == 3 and fields[1] == "UPS" then
+			self.unit:add_info ("UPS: " .. fields[2] .. " - " .. fields[3])
+			return true
+		end
+	end
+end
+
+function NUT:on_data (data)
+	self.buf = self.buf .. data
+	repeat
+		local line, rest = self.buf:match ("([^\n]*)\n(.*)")
+		if not line then return end
+		self.buf = rest
+	until not self:process (line)
+	self.unit:stop ()
+end
+
+ponymap.register_service {
+	name = "NUT",
+	flags = 0,
+	new_scan = NUT.new
+}