1 files changed, 42 insertions, 0 deletions
diff --git a/tester/rt/tftpy/TftpPacketFactory.py b/tester/rt/tftpy/TftpPacketFactory.py
new file mode 100644
index 0000000..928fe07
--- /dev/null
+++ b/tester/rt/tftpy/TftpPacketFactory.py
@@ -0,0 +1,42 @@
+"""This module implements the TftpPacketFactory class, which can take a binary
+buffer, and return the appropriate TftpPacket object to represent it, via the
+parse() method."""
+
+from __future__ import absolute_import, division, print_function, unicode_literals
+from .TftpShared import *
+from .TftpPacketTypes import *
+
+class TftpPacketFactory(object):
+    """This class generates TftpPacket objects. It is responsible for parsing
+    raw buffers off of the wire and returning objects representing them, via
+    the parse() method."""
+    def __init__(self):
+        self.classes = {
+            1: TftpPacketRRQ,
+            2: TftpPacketWRQ,
+            3: TftpPacketDAT,
+            4: TftpPacketACK,
+            5: TftpPacketERR,
+            6: TftpPacketOACK
+            }
+
+    def parse(self, buffer):
+        """This method is used to parse an existing datagram into its
+        corresponding TftpPacket object. The buffer is the raw bytes off of
+        the network."""
+        log.debug("parsing a %d byte packet" % len(buffer))
+        (opcode,) = struct.unpack("!H", buffer[:2])
+        log.debug("opcode is %d" % opcode)
+        packet = self.__create(opcode)
+        packet.buffer = buffer
+        return packet.decode()
+
+    def __create(self, opcode):
+        """This method returns the appropriate class object corresponding to
+        the passed opcode."""
+        tftpassert(opcode in self.classes,
+                   "Unsupported opcode: %d" % opcode)
+
+        packet = self.classes[opcode]()
+
+        return packet