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)
