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[dhcp_relay] Cover chained requests without Option 82 #26324

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[dhcp_relay] Cover chained requests without Option 82 #26324

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53 changes: 42 additions & 11 deletions ansible/roles/test/files/ptftests/py3/dhcp_relay_test.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -174,6 +174,9 @@
self.portchannels_ip_list = self.test_params.get('portchannels_ip_list', None)
self.agent_relay_mode = self.test_params.get('agent_relay_mode', None)
self.max_hop_count = self.test_params.get('max_hop_count', None)
self.client_giaddr = self.test_params.get('client_giaddr', self.switch_loopback_ip)
self.include_client_option82 = self.test_params.get('include_client_option82', True)
self.expected_forward = self.test_params.get('expected_forward', None)
self.client_vrf = self.test_params.get('client_vrf', None)
self.dhcpv4_disable_flag = self.test_params.get('dhcpv4_disable_flag', None)
if self.relay_agent == "sonic-relay-agent":
Expand Down Expand Up @@ -300,11 +303,12 @@
discover_packet[scapy.IP].src = self.client_ip
discover_packet[scapy.IP].dst = self.switch_loopback_ip
discover_packet[scapy.BOOTP].hops = self.max_hop_count if self.max_hop_count == self.MAX_HOP_COUNT else 1
discover_packet[scapy.BOOTP].giaddr = self.switch_loopback_ip
discover_packet[scapy.DHCP].options.insert(
discover_packet[scapy.DHCP].options.index("end"),
(82, relay_option82)
)
discover_packet[scapy.BOOTP].giaddr = self.client_giaddr
if self.include_client_option82:
discover_packet[scapy.DHCP].options.insert(
discover_packet[scapy.DHCP].options.index("end"),
(82, relay_option82)
)

return discover_packet

Expand Down Expand Up @@ -337,8 +341,10 @@
else:
source_ip = self.portchannels_ip_list[0]

if ((self.link_selection and self.source_interface) or
self.server_vrf or self.dual_tor or self.agent_relay_mode):
if self.agent_relay_mode and self.client_giaddr:
giaddr = self.client_giaddr
elif ((self.link_selection and self.source_interface) or
self.server_vrf or self.dual_tor):
giaddr = self.switch_loopback_ip
elif self.server_id_override or not self.dual_tor:
giaddr = self.relay_iface_ip
Expand All @@ -349,7 +355,10 @@
dport=self.DHCP_SERVER_PORT, len=308)

# Relay-side behavior based on agent_mode
if self.agent_relay_mode == "discard":
if not self.include_client_option82:
dhcp_options = [('message-type', 'discover'), ('end')]

elif self.agent_relay_mode == "discard":
dhcp_options = [('message-type', 'discover'), (82, self.option82), ('end')]

elif self.agent_relay_mode == "replace":
Expand Down Expand Up @@ -1201,13 +1210,35 @@

def check_relayed_pkts_on_server_side(self, mask, pkt, packet_type):
logger.info("Expect receiving {} packets from port [{}]".format(packet_type, self.server_port_indices))
log_dhcp_packet_info(pkt)

Check failure

Code scanning / CodeQL

Potentially uninitialized local variable Error test

Local variable 'expected_forward' may be used before it is initialized.
num_expected_packets = self.num_dhcp_servers
if self.agent_relay_mode == "discard" or self.dhcpv4_disable_flag or self.max_hop_count == self.MAX_HOP_COUNT:
# Expected result: No packet sent
if self.expected_forward is None:
expected_forward = not (
self.agent_relay_mode == "discard"
or self.dhcpv4_disable_flag
or self.max_hop_count == self.MAX_HOP_COUNT
)
else:
expected_forward = self.expected_forward
if expected_forward:
packet_mask = mask
else:
num_expected_packets = 0
unexpected_packet = (
scapy.Ether(src=self.uplink_mac)
/ scapy.IP()
/ scapy.UDP(sport=self.DHCP_SERVER_PORT, dport=self.DHCP_SERVER_PORT)
)
packet_mask = Mask(unexpected_packet)
packet_mask.set_do_not_care_scapy(scapy.Ether, "dst")
for field in ("version", "ihl", "tos", "len", "id", "flags",
"frag", "ttl", "chksum", "src", "dst", "options"):
packet_mask.set_do_not_care_scapy(scapy.IP, field)
packet_mask.set_do_not_care_scapy(scapy.UDP, "chksum")
packet_mask.set_do_not_care_scapy(scapy.UDP, "len")
packet_mask.set_ignore_extra_bytes()
captured_count = testutils.count_matched_packets_all_ports(
self, mask, self.server_port_indices)
self, packet_mask, self.server_port_indices)
self.assertTrue(captured_count == num_expected_packets,
"Failed: %s packet counts are not equal %d != %d"
% (packet_type, captured_count, num_expected_packets))
Expand Down
62 changes: 62 additions & 0 deletions tests/dhcp_relay/test_dhcpv4_relay.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -79,6 +79,7 @@ def _restore_interface_ip_entries(duthost, saved_entries):
CLIENT_VRF_NAME = "Vrf01" # Global macro for Client VRF
MAX_HOP_COUNT = 16
CONFIG_HOP_COUNT = 2
DOWNSTREAM_RELAY_IP = '192.0.2.1' # TEST-NET-1; synthetic downstream relay

logger = logging.getLogger(__name__)

Expand Down Expand Up @@ -439,6 +440,67 @@ def test_dhcp_relay_agent_mode(
sonic_dhcp_relay_config(duthost, dut_dhcp_relay_data)


def test_dhcp_relay_chained_request_without_option82(
ptfhost,
dut_dhcp_relay_data,
validate_dut_routes_exist,
testing_config,
setup_standby_ports_on_rand_unselected_tor,
rand_unselected_dut,
toggle_all_simulator_ports_to_rand_selected_tor_m, # noqa: F811
relay_agent # noqa: F811
):
"""Verify native relay forwards a chained request without adding Option 82."""
testing_mode, duthost = testing_config

try:
for dhcp_relay in dut_dhcp_relay_data:
vlan = str(dhcp_relay['downlink_vlan_iface']['name'])
dhcp_servers = ",".join(dhcp_relay['downlink_vlan_iface']['dhcp_server_addrs'])
duthost.shell(f'config dhcpv4_relay del {vlan}')
duthost.shell(f'config dhcpv4_relay add --dhcpv4-servers {dhcp_servers}'
f' --agent-relay-mode discard {vlan}')

ptf_runner(
ptfhost,
"ptftests",
"dhcp_relay_test.DHCPTest",
platform_dir="ptftests",
params={
"hostname": duthost.hostname,
"client_port_index": dhcp_relay['client_iface']['port_idx'],
"other_client_port": repr(dhcp_relay['other_client_ports']),
"client_iface_alias": str(dhcp_relay['client_iface']['alias']),
"leaf_port_indices": repr(dhcp_relay['uplink_port_indices']),
"num_dhcp_servers": len(dhcp_relay['downlink_vlan_iface']['dhcp_server_addrs']),
"server_ip": dhcp_relay['downlink_vlan_iface']['dhcp_server_addrs'],
"relay_iface_ip": str(dhcp_relay['downlink_vlan_iface']['addr']),
"relay_iface_mac": str(dhcp_relay['downlink_vlan_iface']['mac']),
"relay_iface_netmask": str(dhcp_relay['downlink_vlan_iface']['mask']),
"dest_mac_address": BROADCAST_MAC,
"client_udp_src_port": DEFAULT_DHCP_CLIENT_PORT,
"switch_loopback_ip": dhcp_relay['switch_loopback_ip'],
"uplink_mac": str(dhcp_relay['uplink_mac']),
"testing_mode": testing_mode,
"kvm_support": True,
"relay_agent": relay_agent,
"agent_relay_mode": "discard",
"client_giaddr": DOWNSTREAM_RELAY_IP,
"include_client_option82": False,
"expected_forward": True,
"downlink_vlan_iface_name": str(dhcp_relay['downlink_vlan_iface']['name']),
},
log_file="/tmp/test_dhcp_relay_chained_no_option82.log",
is_python3=True
)
except LogAnalyzerError as err:
logger.error("Unable to find expected log in syslog")
raise err
finally:
sonic_dhcp_relay_unconfig(duthost, dut_dhcp_relay_data)
sonic_dhcp_relay_config(duthost, dut_dhcp_relay_data)


@pytest.mark.parametrize("testcase", ["vrf_selection", "source_intf", "server_id_override"])
def test_dhcp_relay_with_non_default_vrf(
ptfhost,
Expand Down
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