tests: Implement test suit with common setups, based on BCC

Check the documentation for more details:
https://phabricator.vyos.net/T4180

Signed-off-by: Volodymyr Huti <[email protected]>

tests/topotests/bgp_qppb_flow/__init__.py

@@ -0,0 +1,201 @@
+#!/usr/bin/env python
+#
+# SPDX-License-Identifier: ISC
+# Copyright (c) 2023 VyOS Inc.
+# Volodymyr Huti <[email protected]>
+#
+
+import os
+import sys
+import json
+import pytest
+
+from lib.topolog import logger
+from lib.common_config import (
+    start_router_daemons,
+    kill_router_daemons,
+)
+
+from bcc import BPF, DEBUG_PREPROCESSOR, DEBUG_SOURCE, DEBUG_BPF, DEBUG_BTF
+from pyroute2.netns import pushns, popns
+from pyroute2 import IPRoute
+from ctypes import Structure, c_int, c_uint, c_ubyte
+from enum import Enum
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+sys.path.append(os.path.join(CWD, "../lib/"))
+
+# os.environ["PYTHONBREAKPOINT"] = "pudb.set_trace"
+DEV_DEBUG = False
+
+
+class BgpPolicy(Enum):
+    NONE = c_int(0)
+    Dst = c_int(1)
+    Src = c_int(2)
+
+
+class XdpMode(str, Enum):
+    META = "MARK_META"
+    SKB = "MARK_SKB"
+
+
+class KeyV4(Structure):
+    _fields_ = [("prefixlen", c_uint), ("data", c_ubyte * 4)]
+
+
+def router_attach_xdp(rnode, iface):
+    """
+    - swap netns to rnode,
+    - attach `xdp_qppb` to `iface`
+    - switch back to root ns
+    """
+    ns = "/proc/%d/ns/net" % rnode.net.pid
+    qppb_fn = rnode.bpf.funcs[b"xdp_qppb"]
+
+    pushns(ns)
+    logger.debug("Attach XDP handler '{}'\nNetNS --> {})".format(iface, ns))
+    rnode.bpf.attach_xdp(iface, qppb_fn, BPF.XDP_FLAGS_DRV_MODE)
+    popns()
+
+
+def router_remove_xdp(rnode, iface):
+    pushns("/proc/%d/ns/net" % rnode.net.pid)
+    logger.debug("Removing XDP handler for {}:{}".format(rnode.name, iface))
+    rnode.bpf.remove_xdp(iface)
+    popns()
+
+
+def load_qppb_plugin(tgen, rnode, mode=XdpMode.SKB, debug_on=DEV_DEBUG):
+    """
+    Initialize rnode XDP hooks and BPF mapping handlers
+      - compile xdp handlers from `xdp_qppb.c` in specified `mode`
+      - load `xdp_qppb` and `xdp_tc_mark` hooks
+      - restart router with QPPB plugin
+
+    Parameters
+    ----------
+    * `tgen`: topogen object
+    * `rnode`: router object
+    * `mode`: xdp processing mode required
+    * `debug_on`: enable debug logs for bpf compilation / xdp handlers
+
+    Usage
+    ---------
+    load_qppb_plugin(tgen, r1, mode=XdpMode.META)
+    Returns -> None (XXX)
+    """
+    debug_flags = DEBUG_BPF | DEBUG_PREPROCESSOR | DEBUG_SOURCE | DEBUG_BTF
+    debug = debug_flags if debug_on else 0
+    src_file = CWD + "/bgp_xdp_qppb.c"
+    bpf_flags = [
+        '-DMODE_STR="{}"'.format(mode),
+        "-D{}".format(mode.value),
+        "-DRESPECT_TOS",
+        "-w",
+    ]
+    if debug_on:
+        bpf_flags.append("-DLOG_QPPB")
+        bpf_flags.append("-DLOG_TC")
+
+    try:
+        logger.info("Preparing the XDP src: " + src_file)
+        b = BPF(src_file=src_file.encode(), cflags=bpf_flags, debug=debug)
+
+        logger.info("Loading XDP hooks -- xdp_qppb, xdp_tc_mark")
+        b.load_func(b"xdp_qppb", BPF.XDP)
+        b.load_func(b"xdp_tc_mark", BPF.SCHED_CLS)
+        rnode.bpf = b
+    except Exception as e:
+        pytest.skip("Failed to configure XDP environment -- \n" + str(e))
+
+    qppb_module = "-M vyos_qppb"
+    logger.info(
+        "Restart {}, XDP hooks loading...\nPlugin :: {}".format(rnode.name, qppb_module)
+    )
+    kill_router_daemons(tgen, rnode.name, ["bgpd"])
+    start_router_daemons(tgen, rnode.name, ["bgpd"], {"bgpd": qppb_module})
+
+
+def tc_bpf_filter(rnode, ifid):
+    "Attach tc bpf filter, depends on pyroute2 package"
+    tc_fn = rnode.bpf.funcs[b"xdp_tc_mark"]
+    rnode_ns = "/proc/{}/ns/net".format(rnode.net.pid)
+
+    logger.debug("Attach TC-BPF handler '{}'\nNetNS --> {})".format(ifid, rnode_ns))
+    # ip.tc("add", "clsact", ifid, "1:")
+    pushns(rnode_ns)
+    ip = IPRoute()
+    ip.tc(
+        "add-filter",
+        "bpf",
+        ifid,
+        20,  # XXX:
+        fd=tc_fn.fd,
+        name=tc_fn.name,
+        parent=0x10000,
+        classid=0x10030,  # XXX: should be default? default is taken from htb
+        direct_action=True,
+    )
+    popns()
+
+
+def assert_bw(out, bw_target, tolerance, time=10):
+    "Assert that connection matches BW in Mbits +- %tolerance"
+    _min = bw_target * (1 - tolerance)
+    _max = bw_target * (1 + tolerance)
+    half_samples = time / 2
+    data = json.loads(out)
+    bws = []
+
+    for sample in data["intervals"]:
+        bits = int(sample["sum"]["bits_per_second"])
+        mbits = bits / 1024 / 1024
+        bw = mbits / 8
+        logger.debug("BW sample [{} <= {} <= {}]".format(_min, bw, _max))
+        if _min <= bw <= _max:
+            bws.append(bw)
+
+    _len = len(bws)
+    assert (
+        _len >= half_samples
+    ), "Only {} samples are within targeted BW [{}:{}%]".format(
+        _len, bw_target, tolerance * 100
+    )
+
+
+def bpf_print_trace(b):
+    "XXX: Call this from debugger, to avoid blocking / IO collissions"
+    logger.info("=" * 40)
+    logger.debug("Dump bpf log buffer:\n")
+    line = b.trace_readline(nonblocking=True)
+    while line:
+        logger.debug(line)
+        line = b.trace_readline(nonblocking=True)
+
+
+def tc(rnode, cmd):
+    logger.debug("TC cmd: " + cmd)
+    return rnode.cmd_raises("tc " + cmd)
+
+
+def tc_check(host, cmds):
+    tcoutputs = [tc(host, cmd) for cmd in cmds]
+    for output in tcoutputs:
+        if output != "":
+            logger.debug("TC: " + output)
+
+
+def tc_log_stats(host, iface):
+    if not DEV_DEBUG:
+        return
+    tc_flags = "-g -s -d -p -col"
+    tc_check(
+        host,
+        [
+            tc_flags + " filter ls dev " + iface,
+            tc_flags + " class ls dev " + iface,
+            tc_flags + " qdisc ls ",
+        ],
+    )

tests/topotests/bgp_qppb_flow/bgp_ipv4_nh.ref

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+BGP routing table entry for 10.61.0.1/32, version XX
+Paths: (1 available, best #1, table default)
+  Advertised to non peer-group peers:
+  10.0.0.2
+  10 60
+    10.0.0.2 from 10.0.0.2 (1.0.2.17)
+      Origin incomplete, valid, external, best (First path received)
+      Community: 60:1
+      QOS: Precedence af11 (10)
+      Last update: XXXX

tests/topotests/bgp_qppb_flow/bgp_xdp_qppb.c

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+../../../bgpd/bgp_xdp_qppb.c