def test_05(self): """Test manipulation with VLAN tags""" def check_tags(*tags): self.assertEqual(self.eth.tag_cnt, len(tags)) self.assertEqual(self.eth.get_header_size(), 14 + 4 * len(tags)) self.assertEqual(self.eth.get_ether_type(), 0x0800) for i, tag in enumerate(tags): self.assertEqual( self.eth.get_tag(i).get_buffer_as_string(), tag) # Add S-tag (outer tag, closest to the Ethernet header) self.eth.push_tag(EthernetTag(0x88a85001)) check_tags('\x88\xa8\x50\x01', '\x81\x00\xac\xf3') # Set C-tag (inner tag, closest to the payload) to default self.eth.set_tag(1, EthernetTag()) check_tags('\x88\xa8\x50\x01', '\x81\x00\x00\x00') # Insert a deprecated 802.1QinQ header between S-tag and C-tag self.eth.push_tag(EthernetTag(0x910054d2), index=1) check_tags('\x88\xa8\x50\x01', '\x91\x00\x54\xd2', '\x81\x00\x00\x00') # Test negative indices tags = {} for i in range(-3, 3): tags[i] = self.eth.get_tag(i).get_buffer_as_string() self.assertEqual(tags[-1], tags[2]) self.assertEqual(tags[-2], tags[1]) self.assertEqual(tags[-3], tags[0]) # Accessing non-existent tags raises IndexError self.assertRaises(IndexError, self.eth.get_tag, 3) self.assertRaises(IndexError, self.eth.get_tag, -4) self.assertRaises(IndexError, self.eth.set_tag, 3, EthernetTag()) self.assertRaises(IndexError, self.eth.set_tag, -4, EthernetTag()) # Test Ethernet constructor data = self.eth.get_buffer_as_string() eth_copy = Ethernet(data) self.assertEqual(eth_copy.tag_cnt, 3) self.assertEqual(eth_copy.get_header_size(), 26) self.assertEqual(eth_copy.get_ether_type(), 0x0800) # Remove the deprecated 802.1QinQ header and check resulting frame eth_copy.pop_tag(1) self.assertEqual(eth_copy.tag_cnt, 2) self.assertEqual(eth_copy.get_packet(), self.frame[:12] + tags[0] + tags[2] + self.frame[-2:])
def setUp(self): # Ethernet frame with a 802.1Q tag (TPID=0x8100, PCP=5, DEI=0, VID=3315) # and ethertype 0x0800 (IPv4) self.frame = '\x54\xab\xa3\xb9\x38\x3d\xe2\xef\x8d\xc7\xa8\x5e\x81\x00\xac\xf3\x08\x00' self.eth = Ethernet(self.frame)