Index: nselib/packet.lua
===================================================================
--- nselib/packet.lua	(revision 6672)
+++ nselib/packet.lua	(working copy)
@@ -55,6 +55,12 @@
 	local sum = 0
 	local c
 	local x = b
+	
+	-- fill with 00, this should be done by the code below,
+	-- but it's not. maybe we should fix this someday
+    if x:len() % 2 == 1 then
+    	x = x .. hextobin("00")
+    end
 
 	while x:len() > 1 do
 		c = x:sub(1,2)
@@ -116,6 +122,10 @@
 		if not o:tcp_parse(force_continue) then
 			io.write("Error while parsing TCP packet\n")
 		end
+	elseif o.ip_p == IPPROTO_UDP then
+		if not o:udp_parse(force_continue) then
+			io.write("Error while parsing UDP packet\n")
+		end
 	elseif o.ip_p == IPPROTO_ICMP then
 		if not o:icmp_parse(force_continue) then
 			io.write("Error while parsing ICMP packet\n")
@@ -207,14 +217,31 @@
 	self.ip_v		= bit.rshift(bit.band(self:u8(self.ip_offset + 0), 0xF0), 4)
 	self.ip_hl		=            bit.band(self:u8(self.ip_offset + 0), 0x0F)		-- header_length or data_offset
 end
+-- set tos
+function Packet:ip_set_tos(tos)
+	self:set_u8(self.ip_offset + 1, tos)
+end
 -- set packet length field
 function Packet:ip_set_len(len)
 	self:set_u16(self.ip_offset + 2, len)
 end
+-- set id
+function Packet:ip_set_id(id)
+	self:set_u16(self.ip_offset + 4, id)
+end
+-- set fragment offset + ip flags rf|df|mf
+function Packet:ip_set_off(off)
+	self:set_u16(self.ip_offset + 6, off)
+end
 -- set ttl
 function Packet:ip_set_ttl(ttl)
 	self:set_u8(self.ip_offset + 8, ttl)
 end
+-- set protocol
+function Packet:ip_set_p(protocol)
+	self:set_u8(self.ip_offset + 9, protocol)
+	self.ip_p		= self:u8(self.ip_offset + 9)	
+end
 -- set checksum
 function Packet:ip_set_checksum(checksum)
 	self:set_u16(self.ip_offset + 10, checksum)
@@ -296,6 +323,8 @@
 function Packet:tostring()
 	if self.tcp then
 		return self:tcp_tostring()
+	elseif self.udp then
+		return self:udp_tostring()
 	elseif self.icmp then
 		return self:icmp_tostring()
 	elseif self.ip then
@@ -501,7 +530,62 @@
 end
 
 ----------------------------------------------------------------------------------------------------------------
+-- PARSE UDP HEADER FROM PACKET
+function Packet:udp_parse(force_continue)
+	self.udp = true
+	self.udp_offset		= self.ip_data_offset
+	if string.len(self.buf) < self.udp_offset + 4 then
+		return false
+	end
+	self.udp_sport		= self:u16(self.udp_offset + 0)
+	self.udp_dport		= self:u16(self.udp_offset + 2)
+	if string.len(self.buf) < self.udp_offset + 8 then
+		if force_continue then
+			return true
+		else
+			return false
+		end
+	end
+	self.udp_length		= self:u16(self.udp_offset + 4)
+	self.udp_sum		= self:u16(self.udp_offset + 6)
+	return true
+end
 
+-- return short information about tcp packet
+function Packet:udp_tostring()
+	return string.format(
+		"UDP %s:%i -> %s:%i",
+		self.ip_src, self.udp_sport,
+		self.ip_dst, self.udp_dport
+		)
+end
+
+function Packet:udp_set_sport(port)
+	self:set_u16(self.udp_offset + 0, port)
+end
+function Packet:udp_set_dport(port)
+	self:set_u16(self.udp_offset + 2, port)
+end
+function Packet:udp_set_length(len)
+	self:set_u16(self.udp_offset + 4, len)
+end
+function Packet:udp_set_checksum(sum)
+	self:set_u16(self.udp_offset + 6, sum)
+end
+-- count and save tcp checksum field
+function Packet:udp_count_checksum()
+	self:udp_set_checksum(0)
+	local length	= self.buf:len() - self.udp_offset
+	local b = self.ip_bin_src ..
+		self.ip_bin_dst ..
+		string.char(0) ..
+		string.char(self.ip_p) .. -- proto
+		set_u16("..", 0, length) ..
+		self.buf:sub(self.udp_offset+1)
+	self:udp_set_checksum(in_cksum(b))
+end
+----------------------------------------------------------------------------------------------------------------
+
 -- UTILS
 -- get binary string  as hex string
 function bintohex(str)