Add xml output to resolveall, improve warnings

scripts/resolveall.nse

@@ -26,6 +26,16 @@ record) returned for each host name.
 -- |     74.125.39.105
 -- |     74.125.39.104
 -- |_  Successfully added 6 new targets
+-- @xmloutput
+-- <elem key="newtargets">4</elem>
+-- <table key="hosts">
+--   <table key="google.com">
+--     <elem>74.125.39.106</elem>
+--     <elem>74.125.39.147</elem>
+--     <elem>74.125.39.99</elem>
+--     <elem>74.125.39.103</elem>
+--   </table>
+-- </table>
 
 author = "Kris Katterjohn"
 
@@ -36,7 +46,7 @@ categories = {"safe", "discovery"}
 
 prerule = function()
   if not stdnse.get_script_args("resolveall.hosts") then
-    stdnse.debug3("Skipping '%s' %s, 'resolveall.hosts' argument is missing.", SCRIPT_NAME, SCRIPT_TYPE)
+    stdnse.verbose1("Skipping '%s', missing required argument 'resolveall.hosts'.", SCRIPT_NAME)
     return false
   end
   return true
@@ -50,7 +60,7 @@ local addtargets = function(list)
     if st then
       sum = sum + 1
     else
-      stdnse.debug1("Couldn't add target " .. t .. ": " .. err)
+      stdnse.debug1("Couldn't add target %s: %s", t, err)
     end
   end
 
@@ -64,25 +74,29 @@ action = function()
     hosts = {hosts}
   end
 
-  local sum, output = 0, {}
+  local sum = 0
+  local output = {}
+  local xmloutput = {}
   for _, host in ipairs(hosts) do
     local status, list = nmap.resolve(host, nmap.address_family())
     if status and #list > 0 then
       if target.ALLOW_NEW_TARGETS then
         sum = sum + addtargets(list)
       end
-      table.insert(output,
-      string.format("Host '%s' resolves to:", host))
+      xmloutput[host] = list
+      table.insert(output, string.format("Host '%s' resolves to:", host))
       table.insert(output, list)
     end
   end
 
+  xmloutput = {
+    hosts = xmloutput,
+    newtargets = sum or 0,
+  }
   if sum > 0 then
-    table.insert(output,
-    string.format("Successfully added %d new targets",
-    tostring(sum)))
+    table.insert(output, string.format("Successfully added %d new targets", sum))
   else
     table.insert(output, "Use the 'newtargets' script-arg to add the results as targets")
   end
-  return stdnse.format_output(true, output)
+  return xmloutput, stdnse.format_output(true, output)
 end