Move comma-separated list code to outlib

nselib/outlib.lua

@@ -17,6 +17,7 @@ local yield = coroutine.yield
 
 local table = require "table"
 local sort = table.sort
+local concat = table.concat
 
 local setmetatable = setmetatable
 local ipairs = ipairs
@@ -46,4 +47,32 @@ function sorted_by_key(t)
   return out
 end
 
+local commasep = {
+  __tostring = function (t)
+    return concat(t, ", ")
+  end
+}
+
+--- Comma-separated list output
+--
+-- This adds a <code>__tostring</code> metamethod to a list (integer-indexed
+-- table) so that it will be formatted as a comma-separated list when converted
+-- to a string.
+-- @param t The table to format
+-- @param sep (Optional) list separator character, default: ", "
+function list_sep(t, sep)
+  -- Reuse closures and metatables as much as possible
+  local oldmt = getmetatable(t)
+  local newmt = sep and {
+    __tostring = function(tt)
+      return concat(tt, sep)
+  end} or commasep
+  -- Avoid clobbering old metatable or our static commasep table
+  if oldmt and oldmt ~= commasep then
+    oldmt.__tostring = newmt.__tostring
+  else
+    setmetatable(t, newmt)
+  end
+end
+
 return _ENV

scripts/afp-serverinfo.nse

@@ -1,5 +1,6 @@
 local afp = require "afp"
 local nmap = require "nmap"
+local outlib = require "outlib"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
 local table = require "table"
@@ -88,12 +89,6 @@ categories = {"default", "discovery", "safe"}
 
 portrule = shortport.port_or_service(548, "afp")
 
-local commasep = {
-  __tostring = function (t)
-    return table.concat(t, ", ")
-  end
-}
-
 action = function(host, port)
 
   local socket = nmap.new_socket()
@@ -148,11 +143,11 @@ action = function(host, port)
 
   -- list the supported AFP versions
   result["AFP Versions"] = response.afp_versions
-  setmetatable(result["AFP Versions"], commasep)
+  outlib.list_sep(result["AFP Versions"])
 
   -- list the supported UAMs (User Authentication Modules)
   result["UAMs"] = response.uams
-  setmetatable(result["UAMs"], commasep)
+  outlib.list_sep(result["UAMs"])
 
   -- server signature, not sure of the format here so just showing a hex string
   if response.flags.ServerSignature then

scripts/broadcast-dhcp-discover.nse

@@ -3,7 +3,9 @@ local dhcp = require "dhcp"
 local ipOps = require "ipOps"
 local math = require "math"
 local nmap = require "nmap"
+local outlib = require "outlib"
 local packet = require "packet"
+local rand = require "rand"
 local stdnse = require "stdnse"
 local string = require "string"
 local table = require "table"
@@ -141,12 +143,6 @@ local function dhcp_listener(sock, timeout, xid, result)
   condvar "signal"
 end
 
-local commasep = {
-  __tostring = function (t)
-    return table.concat(t, ", ")
-  end
-}
-
 local function fail (err) return stdnse.format_output(false, err) end
 
 action = function()
@@ -230,7 +226,7 @@ action = function()
     result_table["IP Offered"] = r.yiaddr_str
     for _, v in ipairs(r.options) do
       if(type(v.value) == 'table') then
-        setmetatable(v.value, commasep)
+        outlib.list_sep(v.value)
       end
       result_table[ v.name ] = v.value
     end

scripts/dhcp-discover.nse

@@ -1,6 +1,7 @@
 local dhcp = require "dhcp"
 local rand = require "rand"
 local nmap = require "nmap"
+local outlib = require "outlib"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
 local string = require "string"
@@ -103,12 +104,6 @@ function portrule(host, port)
   return shortport.portnumber(67, "udp")(host, port)
 end
 
-local commasep = {
-  __tostring = function (t)
-    return table.concat(t, ", ")
-  end
-}
-
 action = function(host, port)
   local dhcptype = (stdnse.get_script_args(SCRIPT_NAME .. ".dhcptype") or "DHCPINFORM"):upper()
   local dhcptypeid = dhcp.request_types[dhcptype]
@@ -185,7 +180,7 @@ action = function(host, port)
     end
     for _, v in ipairs(result.options) do
       if type(v.value) == 'table' then
-        setmetatable(v.value, commasep)
+        outlib.list_sep(v.value)
       end
       result_table[ v.name ] = v.value
     end

scripts/ipv6-node-info.nse

@@ -1,6 +1,7 @@
 local dns = require "dns"
 local ipOps = require "ipOps"
 local nmap = require "nmap"
+local outlib = require "outlib"
 local packet = require "packet"
 local stdnse = require "stdnse"
 local string = require "string"
@@ -152,12 +153,6 @@ local function stringify_noop(flags, data)
   return "replied"
 end
 
-local commasep = {
-  __tostring = function (t)
-    return table.concat(t, ", ")
-  end
-}
-
 -- RFC 4620, section 6.3.
 local function stringify_nodename(flags, data)
   local status, names
@@ -170,7 +165,7 @@ local function stringify_nodename(flags, data)
     names[#names+1] = "(parsing error)"
   end
 
-  setmetatable(names, commasep)
+  outlib.list_sep(names)
   return names
 end
 
@@ -195,7 +190,7 @@ local function stringify_nodeaddresses(flags, data)
     addrs[#addrs+1] = "(more omitted for space reasons)"
   end
 
-  setmetatable(addrs, commasep)
+  outlib.list_sep(addrs)
   return addrs
 end
 
@@ -217,7 +212,7 @@ local function stringify_nodeipv4addresses(flags, data)
   -- Check for DNS names.
   status, names = try_decode_nodenames(data .. "\0\0")
   if status then
-    setmetatable(names, commasep)
+    outlib.list_sep(names)
     return names
   end
 
@@ -237,7 +232,7 @@ local function stringify_nodeipv4addresses(flags, data)
     addrs[#addrs+1] = "(more omitted for space reasons)"
   end
 
-  setmetatable(addrs, commasep)
+  outlib.list_sep(addrs)
   return addrs
 end
 

scripts/reverse-index.nse

@@ -1,5 +1,6 @@
 local ipOps = require "ipOps"
 local nmap = require "nmap"
+local outlib = require "outlib"
 local stdnse = require "stdnse"
 local table = require "table"
 local tableaux = require "tableaux"
@@ -85,12 +86,6 @@ hostaction = function(host)
   end
 end
 
-local commasep = {
-  __tostring = function (t)
-    return table.concat(t, ", ")
-  end
-}
-
 postaction = function()
   local db = nmap.registry[SCRIPT_NAME]
   if ( db == nil ) then
@@ -108,7 +103,7 @@ postaction = function()
       local result_entries = ports[port]
       ipOps.ip_sort(result_entries)
       if mode == 'horizontal' then
-        setmetatable(result_entries, commasep)
+        outlib.list_sep(result_entries)
       end
       results[("%s/%s"):format(port, proto)] = result_entries
     end