o The NSE Comm library now defaults to trying to read as many bytes as are

available rather than lines if neither the "bytes" nor "lines" options are
  given.  Thanks to Brandon for reporting a problem which he noticed in the
  dns-test-open-recursion script. [Kris]

CHANGELOG

@@ -65,6 +65,11 @@ o Nmap's Nsock-utilizing subsystems (DNS, NSE, version detection) have been
 
 o Added --ip-options support for the connect() scan (-sT). [Kris]
 
+o The NSE Comm library now defaults to trying to read as many bytes as are
+  available rather than lines if neither the "bytes" nor "lines" options are
+  given.  Thanks to Brandon for reporting a problem which he noticed in the
+  dns-test-open-recursion script. [Kris]
+
 o Changed the order preference of timing ping propes. [Michael]
 
 o Enabled nmap to switch between multiple types of timing pings during port

docs/scripting.xml

@@ -1651,8 +1651,9 @@ if(s) code_to_be_done_on_match end
 	The relevant indexes for this table are <literal>bytes</literal>, <literal>lines</literal>,
 	<literal>proto</literal> and <literal>timeout</literal>.  <literal>bytes</literal>
 	is used to provide the minimum number of bytes required for a read.  <literal>lines</literal>
-	does the same, but for the minimum number of lines.  <literal>proto</literal> is used
+	does the same, but for the minimum number of lines.  If neither are provided, these
-	to set the protocol to communicate with, defaulting to "tcp" if not provided.
+	functions attempt to read as many bytes as are available.  <literal>proto</literal>
+	is used to set the protocol to communicate with, defaulting to "tcp" if not provided.
 	<literal>timeout</literal> is used to set the socket timeout (see the socket function
 	<literal>set_timeout()</literal> for details).
 	</para>

nselib/comm.lua

@@ -27,10 +27,10 @@ module(..., package.seeall)
 --   proto: Specifies the protocol to be used with the connect() call
 --   timeout: Sets the socket's timeout with nmap.set_timeout()
 --
--- If neither lines nor bytes are specified, the calls read as many lines
+-- If neither lines nor bytes are specified, the calls attempt to read as many
--- as possible.  If only bytes if specified, then it only tries to read that
+-- bytes as possible.  If only bytes is specified, then it only tries to read
--- many bytes.  Likewise, it only lines if specified, then it only tries to
+-- that many bytes.  Likewise, it only lines if specified, then it only tries
--- read that many lines.  If they're both specified, the lines value is used.
+-- to read that many lines.  If they're both specified, the lines value is used.
 --
 ------
 
@@ -71,39 +71,24 @@ local setup_connect = function(host, port, opts)
 		return status, err
 	end
 
+	-- If nothing is given, specify bytes=1 so NSE reads everything
+	if not opts.lines and not opts.bytes then
+		opts.bytes = 1
+	end
+
 	return true, sock
 end
 
 local read = function(sock, opts)
-	local line, response, status
+	local response, status
 
 	if opts.lines then
 		status, response = sock:receive_lines(opts.lines)
 		return status, response
-	elseif opts.bytes then
-		status, response = sock:receive_bytes(opts.bytes)
-		return status, response
 	end
 
-	response = ""
+	status, response = sock:receive_bytes(opts.bytes)
-
+	return status, response
-	while true do
-		status, line = sock:receive_lines(1)
-
-		if not status then
-			break
-		end
-
-		response = response .. line
-	end
-
-	-- Either we reached the end of the stream, or we got all we could
-	-- within the socket timeout
-	if line == "EOF" or (line == "TIMEOUT" and response ~= "") then
-		return true, response
-	end
-
-	return false, line
 end
 
 get_banner = function(host, port, opts)

scripts/HTTP_open_proxy.nse

@@ -47,7 +47,7 @@ action = function(host, port)
 
 -- Ask proxy to open www.google.com
 	local req = "GET http://www.google.com HTTP/1.0\r\nHost: www.google.com\r\n\r\n"
-	local status, result = comm.exchange(host, port, req, {proto=port.protocol, timeout=10000})
+	local status, result = comm.exchange(host, port, req, {lines=1,proto=port.protocol, timeout=10000})
 	
 	if not status then
 		return

scripts/HTTPtrace.nse

@@ -79,7 +79,7 @@ portrule = shortport.port_or_service({80, 8080}, "http")
 action = function(host, port)
 	local cmd = "TRACE / HTTP/1.0\r\n\r\n"
 
-	local status, response = comm.exchange(host, port, cmd, {timeout=5000})
+	local status, response = comm.exchange(host, port, cmd, {lines=1,timeout=5000})
 
 	if not status then
 		return

scripts/PPTPversion.nse

@@ -53,7 +53,7 @@ action = function(host, port)
 	payload = payload .. "\000\000\000\000" -- padding for vendor name
 
 	local try = nmap.new_try()
-	local response = try(comm.exchange(host, port, payload, {bytes=1, timeout=5000}))
+	local response = try(comm.exchange(host, port, payload, {timeout=5000}))
 
 	local result
 		

scripts/iax2Detect.nse

@@ -20,7 +20,7 @@ action = function(host, port)
 	poke = poke .. string.char(0x00, 0x00, 0x00, 0x00)  
 	poke = poke .. string.char(0x00, 0x00, 0x06, 0x1e)
 
-	local status, recv = comm.exchange(host, port, poke, {bytes=1,proto=port.protocol,timeout=10000})
+	local status, recv = comm.exchange(host, port, poke, {proto=port.protocol,timeout=10000})
 
 	if not status then
 		return

scripts/nbstat.nse

@@ -65,7 +65,7 @@ action = function(host)
 		"\065\065\065\065\065\000\000\033" ..
 		"\000\001"
 
-	local status, result = comm.exchange(host, 137, data, {bytes=1, proto="udp", timeout=5000})
+	local status, result = comm.exchange(host, 137, data, {proto="udp", timeout=5000})
 
 	if (not status) then
 		return