Adding in_port_range function to nselib/stdnse.lua

nselib/stdnse.lua

@@ -877,3 +877,76 @@ do end -- no function here, see nse_main.lua
 --@name require
 --@class function
 do end -- no function here, see nse_main.lua
+
+
+
+---Checks if the port is in the port range
+-- For example, calling:
+-- <code>in_port_range({number=31337,protocol="udp"},"T:15,50-75,U:31334-31339")</code>
+-- would result in a true value
+--@param port a port structure containing keys port number(number) and protocol(string)
+--@param port_range a port range string in Nmap standard format (ex. "T:80,1-30,U:31337,21-25")
+--@returns boolean indicating whether the port is in the port range
+function in_port_range(port,port_range)
+	assert(port and type(port.number)=="number" and type(port.protocol)=="string" and 
+			(port.protocol=="udp" or port.protocol=="tcp"),"Port structure missing or invalid: port={ number=<port_number>, protocol=<port_protocol> }")
+	assert((type(port_range)=="string" or type(port_range)=="number") and port_range~="","Incorrect port range specification.")
+	
+	-- Proto - true for TCP, false for UDP
+	local proto
+	if(port.protocol=="tcp") then proto = true else proto = false end
+	
+	--TCP flag for iteration - true for TCP, false for UDP, if not specified we presume TCP
+	local tcp_flag = true
+	
+	-- in case the port_range is a single number 
+	if type(port_range)=="number" then
+		if proto and port_range==port.number then return true
+		else return false
+		end
+	end
+	
+	--clean the string a bit
+	port_range=port_range:gsub("%s+","")
+	
+	-- single_pr - single port range
+	for i, single_pr in ipairs(strsplit(",",port_range)) do
+		if single_pr:match("T:") then
+			tcp_flag = true
+			single_pr = single_pr:gsub("T:","")
+		else 
+			if single_pr:match("U:") then 
+				tcp_flag = false 
+				single_pr = single_pr:gsub("U:","")
+			end
+		end
+		
+		-- compare ports only when the port's protocol is the same as
+		-- the current single port range
+		if tcp_flag == proto then
+			local pone = single_pr:match("^(%d+)$")
+			if pone then
+				pone = tonumber(pone)
+				assert(pone>-1 and pone<65536, "Port range number out of range (0-65535).")
+				
+				if pone == port.number then 
+					return true 
+				end
+			else
+				local pstart, pend = single_pr:match("^(%d+)%-(%d+)$")
+				pstart, pend = tonumber(pstart), tonumber(pend)
+				assert(pstart,"Incorrect port range specification.")
+				assert(pstart<=pend,"Incorrect port range specification, the starting port should have a smaller value than the ending port.")
+				assert(pstart>-1 and pstart<65536 and pend>-1 and pend<65536, "Port range number out of range (0-65535).")
+				
+				if port.number >=pstart and port.number <= pend then
+					return true
+				end
+			end
+		end
+	end
+	-- if no match is found then the port doesn't belong to the port_range
+	return false
+end
+
+