Add IPv4 mtu tests

- test_ipv4_oversized_mtu
- test_ipv4_fragmentation

Signed-off-by: Serhiy Boiko <serhiy.boiko@plvision.eu>

DentOS_Framework/DentOsTestbed/src/dent_os_testbed/test/test_suite/functional/ipv4/conftest.py

@@ -1,6 +1,7 @@
 import pytest_asyncio
 
 from dent_os_testbed.lib.ip.ip_route import IpRoute
+from dent_os_testbed.lib.ip.ip_link import IpLink
 from dent_os_testbed.lib.os.sysctl import Sysctl
 
 from dent_os_testbed.utils.test_utils.tgen_utils import (
@@ -80,3 +81,35 @@ async def remove_default_gateway(testbed):
         {"dev": route["dev"], "type": "default", "via": route["gateway"]}
         for route in def_route
     ]}])
+
+
+@pytest_asyncio.fixture()
+async def change_port_mtu(testbed):
+    tgen_dev, dent_devices = await tgen_utils_get_dent_devices_with_tgen(testbed, [], 4)
+    if not tgen_dev or not dent_devices:
+        print("The testbed does not have enough dent with tgen connections")
+        return
+    dent = dent_devices[0].host_name
+    ports = tgen_dev.links_dict[dent][1]
+    mtu = 1000
+
+    # Get current mtu to restore it later
+    out = await IpLink.show(input_data=[{dent: [
+        {"cmd_options": "-j"}
+    ]}], parse_output=True)
+    assert out[0][dent]["rc"] == 0, "Failed to get ports"
+
+    def_mtu_map = [link for link in out[0][dent]["parsed_output"] if link["ifname"] in ports]
+
+    # Configure new mtu
+    out = await IpLink.set(input_data=[{dent: [
+        {"device": port, "mtu": mtu} for port in ports
+    ]}])
+    assert out[0][dent]["rc"] == 0, "Failed to set port mtu"
+
+    yield  # Run the test
+
+    # Restore old mtu
+    out = await IpLink.set(input_data=[{dent: [
+        {"device": link["ifname"], "mtu": link["mtu"]} for link in def_mtu_map
+    ]}])

DentOS_Framework/DentOsTestbed/src/dent_os_testbed/test/test_suite/functional/ipv4/test_ipv4_mtu.py

@@ -0,0 +1,211 @@
+import asyncio
+import pytest
+
+from dent_os_testbed.lib.ip.ip_link import IpLink
+from dent_os_testbed.lib.ip.ip_address import IpAddress
+from dent_os_testbed.lib.ethtool.ethtool import Ethtool
+
+from dent_os_testbed.utils.test_utils.tgen_utils import (
+    tgen_utils_get_dent_devices_with_tgen,
+    tgen_utils_traffic_generator_connect,
+    tgen_utils_dev_groups_from_config,
+    tgen_utils_get_traffic_stats,
+    tgen_utils_setup_streams,
+    tgen_utils_start_traffic,
+    tgen_utils_stop_traffic,
+    tgen_utils_get_loss,
+)
+
+pytestmark = [
+    pytest.mark.suite_functional_ipv4,
+    pytest.mark.usefixtures("cleanup_ip_addrs", "cleanup_tgen", "enable_ipv4_forwarding"),
+    pytest.mark.asyncio,
+]
+
+
+async def get_port_stats(dent, ports):
+    stats = {}
+    for port in ports:
+        out = await Ethtool.show(input_data=[{dent: [
+            {"devname": port, "options": "-S"}
+        ]}], parse_output=True)
+        assert out[0][dent]["rc"] == 0
+        stats[port] = out[0][dent]["parsed_output"]
+    return stats
+
+
+@pytest.mark.usefixtures("change_port_mtu")
+async def test_ipv4_oversized_mtu(testbed):
+    """
+    Test Name: test_ipv4_oversized_mtu
+    Test Suite: suite_functional_ipv4
+    Test Overview: Test IPv4 oversized mtu counters
+    Test Procedure:
+    1. Init interfaces
+    2. Configure ports up
+    3. Configure IP addrs
+    4. Configure interfaces MTU to 1000
+    5. Generate traffic with packet size 1200 and verify there's no reception due to MTU
+    6. Verify oversized counter been incremented in port statistics
+    """
+    # 1. Init interfaces
+    tgen_dev, dent_devices = await tgen_utils_get_dent_devices_with_tgen(testbed, [], 4)
+    if not tgen_dev or not dent_devices:
+        print("The testbed does not have enough dent with tgen connections")
+        return
+    dent = dent_devices[0].host_name
+    tg_ports = tgen_dev.links_dict[dent][0]
+    ports = tgen_dev.links_dict[dent][1]
+    traffic_duration = 10
+    delayed_stats_update_time = 10
+    address_map = (
+        # swp port, tg port,    swp ip,    tg ip,     plen
+        (ports[0], tg_ports[0], "1.1.1.1", "1.1.1.2", 24),
+        (ports[1], tg_ports[1], "2.2.2.1", "2.2.2.2", 24),
+        (ports[2], tg_ports[2], "3.3.3.1", "3.3.3.2", 24),
+        (ports[3], tg_ports[3], "4.4.4.1", "4.4.4.2", 24),
+    )
+    tg_to_swp_map = {
+        tg: swp for swp, tg, *_ in address_map
+    }
+
+    # 2. Configure ports up
+    out = await IpLink.set(input_data=[{dent: [
+        {"device": port, "operstate": "up"}
+        for port, *_ in address_map
+    ]}])
+    assert out[0][dent]["rc"] == 0, "Failed to set port state UP"
+
+    # 3. Configure IP addrs
+    out = await IpAddress.add(input_data=[{dent: [
+        {"dev": port, "prefix": f"{ip}/{plen}"}
+        for port, _, ip, _, plen in address_map
+    ]}])
+    assert out[0][dent]["rc"] == 0, "Failed to add IP addr to port"
+
+    dev_groups = tgen_utils_dev_groups_from_config(
+        {"ixp": port, "ip": ip, "gw": gw, "plen": plen}
+        for _, port, gw, ip, plen in address_map
+    )
+    await tgen_utils_traffic_generator_connect(tgen_dev, tg_ports, ports, dev_groups)
+
+    streams = {
+        f"{tg1} <-> {tg2}": {
+            "type": "ipv4",
+            "ip_source": dev_groups[tg1][0]["name"],
+            "ip_destination": dev_groups[tg2][0]["name"],
+            "protocol": "ip",
+            "rate": "1000",  # pps
+            "frameSize": 1200,
+        } for tg1, tg2 in zip(tg_ports, reversed(tg_ports))
+    }
+
+    await tgen_utils_setup_streams(tgen_dev, None, streams)
+
+    # 4. Port mtu should be configured in the change_port_mtu fixture
+
+    # 5. Generate traffic with packet size 1200
+    old_stats = await get_port_stats(dent, (port for port, *_ in address_map))
+
+    await tgen_utils_start_traffic(tgen_dev)
+    await asyncio.sleep(traffic_duration)
+    await tgen_utils_stop_traffic(tgen_dev)
+
+    await asyncio.sleep(delayed_stats_update_time)  # wait for delayed stats to update
+    new_stats = await get_port_stats(dent, (port for port, *_ in address_map))
+
+    stats = await tgen_utils_get_traffic_stats(tgen_dev, "Flow Statistics")
+    for row in stats.Rows:
+        # Verify there's no reception due to MTU
+        loss = tgen_utils_get_loss(row)
+        assert loss == 100, f"Expected loss: 100%, actual: {loss}%"
+
+        # 6. Verify oversized counter been incremented in port statistics
+        port = tg_to_swp_map[row["Tx Port"]]
+        oversized = int(new_stats[port]["oversize"]) - int(old_stats[port]["oversize"])
+        assert oversized == int(row["Tx Frames"])
+
+
+@pytest.mark.xfail(reason="Device does not support fragmentation")
+async def test_ipv4_fragmentation(testbed):
+    """
+    Test Name: test_ipv4_fragmentation
+    Test Suite: suite_functional_ipv4
+    Test Overview: Test IPv4 fragmentation
+    Test Procedure:
+    1. Init interfaces
+    2. Configure ports up
+    3. Configure IP addrs
+    4. Generate Non-fragment/fragment traffic and verify reception
+    """
+    # 1. Init interfaces
+    tgen_dev, dent_devices = await tgen_utils_get_dent_devices_with_tgen(testbed, [], 4)
+    if not tgen_dev or not dent_devices:
+        print("The testbed does not have enough dent with tgen connections")
+        return
+    dent = dent_devices[0].host_name
+    tg_ports = tgen_dev.links_dict[dent][0]
+    ports = tgen_dev.links_dict[dent][1]
+    traffic_duration = 10
+    fragmented = 1522
+    non_fragmented = 1420
+    address_map = (
+        # swp port, tg port,    swp ip,    tg ip,     plen
+        (ports[0], tg_ports[0], "1.1.1.1", "1.1.1.2", 24),
+        (ports[1], tg_ports[1], "2.2.2.1", "2.2.2.2", 24),
+        (ports[2], tg_ports[2], "3.3.3.1", "3.3.3.2", 24),
+        (ports[3], tg_ports[3], "4.4.4.1", "4.4.4.2", 24),
+    )
+
+    # 2. Configure ports up
+    out = await IpLink.set(input_data=[{dent: [
+        {"device": port, "operstate": "up"}
+        for port, *_ in address_map
+    ]}])
+    assert out[0][dent]["rc"] == 0, "Failed to set port state UP"
+
+    # 3. Configure IP addrs
+    out = await IpAddress.add(input_data=[{dent: [
+        {"dev": port, "prefix": f"{ip}/{plen}"}
+        for port, _, ip, _, plen in address_map
+    ]}])
+    assert out[0][dent]["rc"] == 0, "Failed to add IP addr to port"
+
+    dev_groups = tgen_utils_dev_groups_from_config(
+        {"ixp": port, "ip": ip, "gw": gw, "plen": plen}
+        for _, port, gw, ip, plen in address_map
+    )
+    await tgen_utils_traffic_generator_connect(tgen_dev, tg_ports, ports, dev_groups)
+
+    streams = {
+        f"{tg1} <-> {tg2} | frame size {size}": {
+            "type": "ipv4",
+            "ip_source": dev_groups[tg1][0]["name"],
+            "ip_destination": dev_groups[tg2][0]["name"],
+            "protocol": "ip",
+            "rate": "1000",  # pps
+            "frameSize": size,
+            "bi_directional": True,
+        } for tg1, tg2, size in ((tg_ports[0], tg_ports[1], non_fragmented),
+                                 (tg_ports[2], tg_ports[3], fragmented))
+    }
+
+    # 4. Generate Non-fragment/fragment traffic and verify reception
+    await tgen_utils_setup_streams(tgen_dev, None, streams)
+
+    await tgen_utils_start_traffic(tgen_dev)
+    await asyncio.sleep(traffic_duration)
+    await tgen_utils_stop_traffic(tgen_dev)
+
+    # Verify packet discarded/fwd
+    stats = await tgen_utils_get_traffic_stats(tgen_dev, "Flow Statistics")
+    for row in stats.Rows:
+        loss = tgen_utils_get_loss(row)
+
+        if str(non_fragmented) in row["Traffic Item"]:
+            assert loss == 0, f"Expected loss: 0%, actual: {loss}%"
+            assert row["Tx Frames"] == row["Rx Frames"], \
+                f"Expected Tx Frames {row['Tx Frames']} to equal Rx Frames {row['Rx Frames']}"
+        else:  # fragmented traffic
+            assert int(row["Rx Frames"]) == int(row["Tx Frames"]) * 2, \
+                f"Expected Rx Frames {row['Rx Frames']} to equal 2 * Tx Frames {2 * int(row['Tx Frames'])}"