| Rich Lane | 629393f | 2013-01-10 15:37:33 -0800 | [diff] [blame] | 1 | """ |
| 2 | OpenFlow instruction list class |
| 3 | """ |
| 4 | |
| 5 | import action as action |
| 6 | import instruction as instruction |
| 7 | from action_list import action_list |
| 8 | from base_list import ofp_base_list |
| 9 | from cstruct import ofp_header |
| 10 | import unittest |
| 11 | |
| 12 | # Instruction list |
| 13 | |
| 14 | instruction_object_map = { |
| 15 | action.OFPIT_GOTO_TABLE : instruction.instruction_goto_table, |
| 16 | action.OFPIT_WRITE_METADATA : instruction.instruction_write_metadata, |
| 17 | action.OFPIT_WRITE_ACTIONS : instruction.instruction_write_actions, |
| 18 | action.OFPIT_APPLY_ACTIONS : instruction.instruction_apply_actions, |
| 19 | action.OFPIT_CLEAR_ACTIONS : instruction.instruction_clear_actions, |
| 20 | } |
| 21 | |
| 22 | class instruction_list(ofp_base_list): |
| 23 | """ |
| 24 | Maintain a list of instructions |
| 25 | |
| 26 | Data members: |
| 27 | @arg instructions An array of instructions such as write_actions |
| 28 | |
| 29 | Methods: |
| 30 | @arg pack: Pack the structure into a string |
| 31 | @arg unpack: Unpack a string to objects, with proper typing |
| 32 | @arg add: Add an action to the list; you can directly access |
| 33 | the action member, but add will validate that the added object |
| 34 | is an action. |
| 35 | |
| 36 | """ |
| 37 | |
| 38 | def __init__(self): |
| 39 | ofp_base_list.__init__(self) |
| 40 | self.instructions = self.items |
| 41 | self.name = "instruction" |
| 42 | self.class_list = instruction.instruction_class_list |
| 43 | |
| 44 | def unpack(self, binary_string, bytes=None): |
| 45 | """ |
| 46 | Unpack a list of instructions |
| 47 | |
| 48 | Unpack instructions from a binary string, creating an array |
| 49 | of objects of the appropriate type |
| 50 | |
| 51 | @param binary_string The string to be unpacked |
| 52 | |
| 53 | @param bytes The total length of the instruction list in bytes. |
| 54 | Ignored if decode is True. If bytes is None and decode is false, the |
| 55 | list is assumed to extend through the entire string. |
| 56 | |
| 57 | @return The remainder of binary_string that was not parsed |
| 58 | |
| 59 | """ |
| 60 | if bytes == None: |
| 61 | bytes = len(binary_string) |
| 62 | bytes_done = 0 |
| 63 | count = 0 |
| 64 | cur_string = binary_string |
| 65 | while bytes_done < bytes: |
| 66 | hdr = instruction.ofp_instruction() |
| 67 | hdr.unpack(cur_string) |
| 68 | if hdr.len < action.OFP_ACTION_HEADER_BYTES: |
| 69 | print "ERROR: Action too short" |
| 70 | break |
| 71 | if not hdr.type in instruction_object_map.keys(): |
| 72 | print "WARNING: Skipping unknown action ", hdr.type, hdr.len |
| 73 | else: |
| 74 | self.instructions.append(instruction_object_map[hdr.type]()) |
| 75 | self.instructions[count].unpack(cur_string) |
| 76 | count += 1 |
| 77 | cur_string = cur_string[hdr.len:] |
| 78 | bytes_done += hdr.len |
| 79 | return cur_string |
| 80 | |
| 81 | class Instruction_List_Test(unittest.TestCase): |
| 82 | def runTest(self): |
| 83 | # instructions header is 8 bytes |
| 84 | l = instruction_list() |
| 85 | act = action.action_output() |
| 86 | act.port = 7 |
| 87 | inst = instruction.instruction_apply_actions() |
| 88 | self.assertTrue(inst.actions.add(act)) |
| 89 | self.assertTrue(l.add(inst)) |
| 90 | pkt = l.pack() |
| 91 | # 24 == 8 (list header) + (apply header) 8 + (output action) 8 |
| 92 | self.assertEqual(len(pkt),24) |
| 93 | |
| 94 | l = instruction_list() |
| 95 | self.assertTrue(l.add(instruction.instruction_goto_table())) |
| 96 | |