[202412] Fix test_configurable_drop_counters.py for v6 topos

tests/common/plugins/conditional_mark/tests_mark_conditions.yaml

@@ -799,13 +799,6 @@ drop_packets:
     conditions:
       - "topo_type in ['m0', 'mx']"
 
-drop_packets/test_configurable_drop_counters.py::test_neighbor_link_down:
-  xfail:
-    reason: "xfail for IPv6-only topologies, issue with python max size"
-    conditions:
-      - "https://github.com/sonic-net/sonic-mgmt/issues/19920 and '-v6-' in topo_name"
-
-
 drop_packets/test_drop_counters.py:
   xfail:
     reason: "xfail for scale topology, PTF is not stable at the scale testbed"

tests/common/plugins/conditional_mark/tests_mark_conditions_drop_packets.yaml

@@ -5,13 +5,14 @@
 #Hence, it is not dropped by default in Cisco-8000. For dropping link local address, it should be done through security/DATA ACL
 drop_packets/test_configurable_drop_counters.py::test_dip_link_local:
   skip:
-    reason: "MGFX topos doesn't support drop packets / Cisco 8000 platform and some mlx platforms does not drop DIP link local packets / KVM do not support drop reason in testcase."
+    reason: "MGFX topos doesn't support drop packets / Cisco 8000 platform and some mlx platforms does not drop DIP link local packets / KVM do not support drop reason in testcase / IPv6 DIP_LINK_LOCAL drop reason not supported on broadcom."
     conditions_logical_operator: or
     conditions:
       - "'Mellanox' in hwsku"
       - asic_type=='cisco-8000'
       - "topo_type in ['m0', 'mx']"
       - "asic_type in ['vs']"
+      - "asic_type in ['broadcom'] and '-v6-' in topo_name"
 
 drop_packets/test_configurable_drop_counters.py::test_neighbor_link_down:
   skip:
@@ -23,13 +24,14 @@ drop_packets/test_configurable_drop_counters.py::test_neighbor_link_down:
 
 drop_packets/test_configurable_drop_counters.py::test_sip_link_local:
   skip:
-    reason: "MGFX topos doesn't support drop packets / Cisco 8000 platform and some MLX platforms does not drop SIP link local packets / KVM do not support drop reason in testcase."
+    reason: "MGFX topos doesn't support drop packets / Cisco 8000 platform and some MLX platforms does not drop SIP link local packets / KVM do not support drop reason in testcase / IPv6 DIP_LINK_LOCAL drop reason not supported on broadcom."
     conditions_logical_operator: or
     conditions:
       - asic_type=="cisco-8000"
       - "'Mellanox' in hwsku"
       - "topo_type in ['m0', 'mx']"
       - "asic_type in ['vs']"
+      - "asic_type in ['broadcom'] and '-v6-' in topo_name"
 
 #######################################
 #####     test_drop_counters.py   #####

tests/drop_packets/test_configurable_drop_counters.py

@@ -18,11 +18,13 @@
 
 import pytest
 import ptf.testutils as testutils
-from netaddr import IPNetwork, EUI
+import ipaddress
+from netaddr import EUI
 
 from . import configurable_drop_counters as cdc
 from tests.common.helpers.assertions import pytest_assert
 from tests.common.utilities import wait_until
+from tests.common.utilities import is_ipv6_only_topology
 from tests.common.platform.device_utils import fanout_switch_port_lookup
 from tests.common.dualtor.mux_simulator_control import toggle_all_simulator_ports_to_rand_selected_tor_m    # noqa F401
 from tests.common.fixtures.ptfhost_utils import copy_arp_responder_py       # noqa F401
@@ -42,7 +44,9 @@
 VLAN_BASE_MAC_PATTERN = "72060001{:04}"
 
 MOCK_DEST_IP = "2.2.2.2"
-LINK_LOCAL_IP = "169.254.0.1"
+MOCK_DEST_IP_V6 = "2001:db8::2"
+LINK_LOCAL_IP = "169.254.0.1"  # 169.254.0.0/16
+LINK_LOCAL_IP_V6 = "fe81::1"  # fe80::/10
 
 
 # For dualtor
@@ -131,7 +135,10 @@ def verifyFdbArp(duthost, dst_ip, dst_mac, dst_intf):
     Check if the ARP and FDB entry is present
     """
     logging.info("Verify if the ARP and FDB entry is present for {}".format(dst_ip))
-    result = duthost.command("show arp {}".format(dst_ip))
+    if is_ipv4_address(dst_ip):
+        result = duthost.command("show arp {}".format(dst_ip))
+    else:
+        result = duthost.command("show ndp {}".format(dst_ip))
     pytest_assert("Total number of entries 1" in result['stdout'],
                   "ARP entry for {} missing in ASIC".format(dst_ip))
     result = duthost.shell("ip neigh show {}".format(dst_ip))
@@ -170,7 +177,10 @@ def test_neighbor_link_down(testbed_params, setup_counters, duthosts, rand_one_d
                              if port != mock_server["server_dst_port"]])
     logging.info("Selected port %s to send traffic", rx_port)
 
-    src_ip = MOCK_DEST_IP
+    if is_ipv6_only_topology(tbinfo):
+        src_ip = MOCK_DEST_IP_V6
+    else:
+        src_ip = MOCK_DEST_IP
     pkt = generate_dropped_packet(rx_port, src_ip, mock_server["server_dst_addr"])
 
     try:
@@ -198,7 +208,7 @@ def test_neighbor_link_down(testbed_params, setup_counters, duthosts, rand_one_d
 
 
 @pytest.mark.parametrize("drop_reason", ["DIP_LINK_LOCAL"])
-def test_dip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_hostname,
+def test_dip_link_local(testbed_params, setup_counters, duthosts, tbinfo, rand_one_dut_hostname,
                         toggle_all_simulator_ports_to_rand_selected_tor_m,                      # noqa F811
                         setup_standby_ports_on_rand_unselected_tor,                             # noqa F811
                         send_dropped_traffic, drop_reason, add_default_route_to_dut, generate_dropped_packet):
@@ -214,8 +224,13 @@ def test_dip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_h
     rx_port = random.choice(list(testbed_params["physical_port_map"].keys()))
     logging.info("Selected port %s to send traffic", rx_port)
 
-    src_ip = "10.10.10.10"
-    pkt = generate_dropped_packet(rx_port, src_ip, LINK_LOCAL_IP)
+    if is_ipv6_only_topology(tbinfo):
+        src_ip = "2001:db8::10:10"
+        dst_ip = LINK_LOCAL_IP_V6
+    else:
+        src_ip = "10.10.10.10"
+        dst_ip = LINK_LOCAL_IP
+    pkt = generate_dropped_packet(rx_port, src_ip, dst_ip)
 
     try:
         send_dropped_traffic(counter_type, pkt, rx_port)
@@ -225,7 +240,7 @@ def test_dip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_h
 
 
 @pytest.mark.parametrize("drop_reason", ["SIP_LINK_LOCAL"])
-def test_sip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_hostname,
+def test_sip_link_local(testbed_params, setup_counters, duthosts, tbinfo, rand_one_dut_hostname,
                         toggle_all_simulator_ports_to_rand_selected_tor_m,                      # noqa F811
                         setup_standby_ports_on_rand_unselected_tor,                             # noqa F811
                         send_dropped_traffic, drop_reason, add_default_route_to_dut, generate_dropped_packet):
@@ -241,8 +256,13 @@ def test_sip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_h
     rx_port = random.choice(list(testbed_params["physical_port_map"].keys()))
     logging.info("Selected port %s to send traffic", rx_port)
 
-    dst_ip = "10.10.10.10"
-    pkt = generate_dropped_packet(rx_port, LINK_LOCAL_IP, dst_ip)
+    if is_ipv6_only_topology(tbinfo):
+        src_ip = LINK_LOCAL_IP_V6
+        dst_ip = "2001:db8::10:10"
+    else:
+        src_ip = LINK_LOCAL_IP
+        dst_ip = "10.10.10.10"
+    pkt = generate_dropped_packet(rx_port, src_ip, dst_ip)
 
     try:
         send_dropped_traffic(counter_type, pkt, rx_port)
@@ -486,24 +506,34 @@ def mock_server(fanouthosts, testbed_params, arp_responder, ptfadapter, duthosts
 
 
 @pytest.fixture
-def generate_dropped_packet(duthosts, rand_one_dut_hostname, testbed_params, vlan_mac):
+def generate_dropped_packet(duthosts, tbinfo, rand_one_dut_hostname, testbed_params, vlan_mac):
 
     def _get_simple_ip_packet(rx_port, src_ip, dst_ip):
         dst_mac = vlan_mac if rx_port in testbed_params["vlan_ports"] \
             else duthost.get_dut_iface_mac(testbed_params["physical_port_map"][rx_port])
         src_mac = "DE:AD:BE:EF:12:34"
         # send tagged packet for t0-backend whose vlan mode is tagged
         enable_vlan = rx_port in testbed_params["vlan_ports"] and testbed_params["vlan_interface"]["type"] == "tagged"
-        packet_params = dict(
-            eth_src=src_mac,
-            eth_dst=dst_mac,
-            ip_src=src_ip,
-            ip_dst=dst_ip
-        )
+        if is_ipv6_only_topology(tbinfo):
+            packet_params = dict(
+                eth_src=src_mac,
+                eth_dst=dst_mac,
+                ipv6_src=src_ip,
+                ipv6_dst=dst_ip
+            )
+            pkt_func = testutils.simple_ipv6ip_packet
+        else:
+            packet_params = dict(
+                eth_src=src_mac,
+                eth_dst=dst_mac,
+                ip_src=src_ip,
+                ip_dst=dst_ip
+            )
+            pkt_func = testutils.simple_ip_packet
         if enable_vlan:
             packet_params["dl_vlan_enable"] = enable_vlan
             packet_params["vlan_vid"] = int(testbed_params["vlan_interface"]["attachto"].lstrip("Vlan"))
-        pkt = testutils.simple_ip_packet(**packet_params)
+        pkt = pkt_func(**packet_params)
 
         logging.info("Generated simple IP packet (SMAC=%s, DMAC=%s, SIP=%s, DIP=%s)",
                      src_mac, dst_mac, src_ip, dst_ip)
@@ -522,13 +552,15 @@ def _generate_vlan_servers(vlan_network, vlan_ports):
     # - MACs are generated sequentially as offsets from VLAN_BASE_MAC_PATTERN
     # - IP addresses are randomly selected from the given VLAN network
     # - "Hosts" (IP/MAC pairs) are distributed evenly amongst the ports in the VLAN
-    addr_list = list(IPNetwork(vlan_network))
+    network = ipaddress.ip_network(vlan_network, strict=False)
+    # Limit range size to avoid len error in random.sample with large IPv6 networks in Python < 3.9
+    max_range = min(network.num_addresses - 1, VLAN_HOSTS * 1000)
+    offsets = random.sample(range(1, max_range + 1), VLAN_HOSTS)
+
     for counter, i in enumerate(range(2, VLAN_HOSTS + 2)):
         mac = VLAN_BASE_MAC_PATTERN.format(counter)
         port = vlan_ports[i % len(vlan_ports)]
-        addr = random.choice(addr_list)
-        # Ensure that we won't get a duplicate ip address
-        addr_list.remove(addr)
+        addr = network.network_address + offsets[counter]
 
         vlan_host_map[port][str(addr)] = mac