Adding my Datafiles NSElib for parsing the nmap-* data files for scripts and also update rpcinfo.nse to use this library. Includes CHANGELOG and docs/scripting.xml updates

CHANGELOG

@@ -8,6 +8,12 @@ o Reformat Nmap COPYING file (e.g. remove C comment markers, reduce
   when presented by the Windows executable (NSIS) installer.  Thanks
   to Jah for the patch (which was modified slightly by Fyodor).
 
+o Added NSE Datafiles library which reads and parses Nmap's nmap-*
+  data files for scripts.  The functions (parse_protocols(),
+  parse_rpc() and parse_services()) return tables with numbers
+  (e.g. port numbers) indexing names (e.g. service names).  The
+  rpcinfo.nse script was also updated to use this library. [Kris]
+
 o Changed the NSE function nmap.set_port_state() so that it checks to
   see if the requested port is already in the requested state.  This
   prevents "Duplicate port" messages during the script scan and the

docs/scripting.xml

@@ -1399,6 +1399,68 @@ if(s) code_to_be_done_on_match end
 	      </listitem>
 	    </varlistentry>
 	</variablelist>
+	</sect2>
+	<sect2 id="nse-lib-datafiles">
+	<title>Data File Parsing Functions</title>
+	<para>
+	The <literal>datafiles</literal> module provides functions for reading and parsing
+	Nmap's data files (e.g. <filename>nmap-protocol</filename>, <filename>nmap-rpc</filename>,
+	etc.).  These functions' return values are setup for use with exception handling via
+	<literal>nmap.new_try()</literal>.
+	</para>
+
+	<variablelist>
+	    <varlistentry>
+	      <term><option>bool, table = datafiles.parse_protocols()</option>
+		  <indexterm><primary>parse_protocols</primary></indexterm></term>
+	      <listitem>
+		  <para>
+			This function reads and parses Nmap's <filename>nmap-protocols</filename>
+			file.  <literal>bool</literal> is a boolen value indicating success.
+			If <literal>bool</literal> is true, then the second returned
+			value is a table with protocol numbers indexing the protocol
+			names.  If <literal>bool</literal> is false, an error message
+			is returned as the second value instead of the table.
+		  </para>
+	      </listitem>
+	    </varlistentry>
+
+	    <varlistentry>
+	      <term><option>bool, table = datafiles.parse_rpc()</option>
+		  <indexterm><primary>parse_rpc</primary></indexterm></term>
+	      <listitem>
+		  <para>
+			This function reads and parses Nmap's <filename>nmap-rpc</filename>
+			file.  <literal>bool</literal> is a boolen value indicating success.
+			If <literal>bool</literal> is true, then the second returned
+			value is a table with RPC numbers indexing the RPC names.  If
+			<literal>bool</literal> is false, an error message is returned
+			as the second value instead of the table.
+		  </para>
+	      </listitem>
+	    </varlistentry>
+
+	    <varlistentry>
+	      <term><option>bool, table = datafiles.parse_services([protocol])</option>
+		  <indexterm><primary>parse_services</primary></indexterm></term>
+	      <listitem>
+		  <para>
+			This function reads and parses Nmap's <filename>nmap-services</filename>
+			file.  <literal>bool</literal> is a boolen value indicating success.
+			If <literal>bool</literal> is true, then the second returned
+			value is a table containing two other tables:
+			<literal>tcp{}</literal> and <literal>udp{}</literal>.
+			<literal>tcp{}</literal> contains services indexed by TCP port
+			numbers.  <literal>udp{}</literal> is the same, but for UDP.
+			You can pass "tcp" or "udp" as an argument to
+			<literal>parse_services()</literal> to only get the corresponding
+			table.  If <literal>bool</literal> is false, an error message is
+			returned as the second value instead of the table.
+		  </para>
+	      </listitem>
+	    </varlistentry>
+	</variablelist>
+
 	</sect2>
 	<sect2 id="nse-lib-stdnse">
 	<title>Various Utility Functions</title>

nselib/datafiles.lua

@@ -0,0 +1,128 @@
+-- Kris Katterjohn 03/2008
+
+module(..., package.seeall)
+
+require 'stdnse'
+
+-- These tables are filled by the following fill* functions
+local protocols_table = {}
+local rpc_table = {}
+local services_table = {tcp={}, udp={}}
+
+-- Fills protocols or rpc table with values read from the nmap-* files
+local filltable = function(filename, table)
+	if #table ~= 0 then
+		return true
+	end
+
+	local path = nmap.fetchfile(filename)
+
+	if path == nil then
+		return false
+	end
+
+	local file = io.open(path, "r")
+
+	-- Loops through file line-by-line
+	while true do
+		local l = file:read()
+
+		if not l then
+			break
+		end
+
+		l = l:gsub("%s*#.*", "")
+
+		if l:len() ~= 0 then
+			local m = l:gsub("^([%a%d_-]+)%s+(%d+).*", "%2=%1")
+
+			if m:match("=") then
+				local t = stdnse.strsplit("=", m)
+				table[tonumber(t[1])] = t[2]
+			end
+		end
+	end
+
+	file:close()
+
+	return true
+end
+
+-- Fills services_table{} with values read from nmap-services
+local fillservices = function()
+	if #services_table["tcp"] ~= 0 or
+	   #services_table["udp"] ~= 0 then
+		return true
+	end
+
+	local path = nmap.fetchfile("nmap-services")
+
+	if path == nil then
+		return false
+	end
+
+	local file = io.open(path, "r")
+
+	-- Loops through nmap-services line-by-line
+	while true do
+		local l = file:read()
+
+		if not l then
+			break
+		end
+
+		l = l:gsub("%s*#.*", "")
+
+		if l:len() ~= 0 then
+			local m = l:gsub("^([%a%d_-]+)%s+([%a%d/]+).*", "%2=%1")
+
+			if m:match("=") and m:match("/") then
+				local t = stdnse.strsplit("=", m)
+				local s = stdnse.strsplit("/", t[1])
+
+				if s[2] ~= "tcp" and s[2] ~= "udp" then
+					services_table = {tcp={}, udp={}}
+					return false
+				end
+
+				services_table[s[2]][tonumber(s[1])] = t[2]
+			end
+		end
+	end
+
+	file:close()
+
+	return true
+end
+
+parse_protocols = function()
+	if not filltable("nmap-protocols", protocols_table) then
+		return false, "Error parsing nmap-protocols"
+	end
+
+	return true, protocols_table
+end
+
+parse_rpc = function()
+	if not filltable("nmap-rpc", rpc_table) then
+		return false, "Error parsing nmap-rpc"
+	end
+
+	return true, rpc_table
+end
+
+parse_services = function(protocol)
+	if protocol and protocol ~= "tcp" and protocol ~= "udp" then
+		return false, "Bad protocol for nmap-services: use tcp or udp"
+	end
+
+	if not fillservices() then
+		return false, "Error parsing nmap-services"
+	end
+
+	if protocol then
+		return true, services_table[protocol]
+	end
+	return true, services_table
+end
+

scripts/rpcinfo.nse

@@ -7,44 +7,7 @@ categories = {"safe","discovery"}
 
 require "shortport"
 require "packet"
-require "stdnse"
-
-local rpc_numbers = {}
-
--- Fills rpc_numbers with values read from RPC file - Kris Katterjohn
-local fillrpc = function()
-	local path = nmap.fetchfile("nmap-rpc")
-
-	if path == nil then
-		return false, "Can't read from RPC file!"
-	end
-
-	local file = io.open(path, "r")
-
-	-- Loops through RPC file line-by-line
-	while true do
-		local l = file:read()
-
-		if not l then
-			break
-		end
-
-		l = l:gsub("%s*#.*", "")
-
-		if l:len() ~= 0 then
-			local m = l:gsub("^([%a%d_]+)%s+(%d+).*", "%2=%1")
-
-			if m:match("=") then
-				local t = stdnse.strsplit("=", m)
-				rpc_numbers[tonumber(t[1])] = t[2]
-			end
-		end
-	end
-
-	file:close()
-
-	return true
-end
+require "datafiles"
 
 portrule = shortport.port_or_service(111, "rpcbind")
 
@@ -53,10 +16,11 @@ action = function(host, port)
   local transaction_id = "nmap"
   local socket = nmap.new_socket()
   local result = " \n"
+  local rpc_numbers
 
   catch = function() socket:close() end
   try = nmap.new_try( catch )
-  try( fillrpc() )
+  rpc_numbers = try(datafiles.parse_rpc())
 
   local request = string.char(0x80,0,0,40) -- fragment header
   request = request .. transaction_id -- transaction id