xref: /linux/tools/testing/selftests/bpf/test_bpftool.py (revision f9bff0e31881d03badf191d3b0005839391f5f2b) 
1# SPDX-License-Identifier: GPL-2.0
2# Copyright (c) 2020 SUSE LLC.
3
4import collections
5import functools
6import json
7import os
8import socket
9import subprocess
10import unittest
11
12
13# Add the source tree of bpftool and /usr/local/sbin to PATH
14cur_dir = os.path.dirname(os.path.realpath(__file__))
15bpftool_dir = os.path.abspath(os.path.join(cur_dir, "..", "..", "..", "..",
16                                           "tools", "bpf", "bpftool"))
17os.environ["PATH"] = bpftool_dir + ":/usr/local/sbin:" + os.environ["PATH"]
18
19
20class IfaceNotFoundError(Exception):
21    pass
22
23
24class UnprivilegedUserError(Exception):
25    pass
26
27
28def _bpftool(args, json=True):
29    _args = ["bpftool"]
30    if json:
31        _args.append("-j")
32    _args.extend(args)
33
34    return subprocess.check_output(_args)
35
36
37def bpftool(args):
38    return _bpftool(args, json=False).decode("utf-8")
39
40
41def bpftool_json(args):
42    res = _bpftool(args)
43    return json.loads(res)
44
45
46def get_default_iface():
47    for iface in socket.if_nameindex():
48        if iface[1] != "lo":
49            return iface[1]
50    raise IfaceNotFoundError("Could not find any network interface to probe")
51
52
53def default_iface(f):
54    @functools.wraps(f)
55    def wrapper(*args, **kwargs):
56        iface = get_default_iface()
57        return f(*args, iface, **kwargs)
58    return wrapper
59
60DMESG_EMITTING_HELPERS = [
61        "bpf_probe_write_user",
62        "bpf_trace_printk",
63        "bpf_trace_vprintk",
64    ]
65
66class TestBpftool(unittest.TestCase):
67    @classmethod
68    def setUpClass(cls):
69        if os.getuid() != 0:
70            raise UnprivilegedUserError(
71                "This test suite needs root privileges")
72
73    @default_iface
74    def test_feature_dev_json(self, iface):
75        unexpected_helpers = DMESG_EMITTING_HELPERS
76        expected_keys = [
77            "syscall_config",
78            "program_types",
79            "map_types",
80            "helpers",
81            "misc",
82        ]
83
84        res = bpftool_json(["feature", "probe", "dev", iface])
85        # Check if the result has all expected keys.
86        self.assertCountEqual(res.keys(), expected_keys)
87        # Check if unexpected helpers are not included in helpers probes
88        # result.
89        for helpers in res["helpers"].values():
90            for unexpected_helper in unexpected_helpers:
91                self.assertNotIn(unexpected_helper, helpers)
92
93    def test_feature_kernel(self):
94        test_cases = [
95            bpftool_json(["feature", "probe", "kernel"]),
96            bpftool_json(["feature", "probe"]),
97            bpftool_json(["feature"]),
98        ]
99        unexpected_helpers = DMESG_EMITTING_HELPERS
100        expected_keys = [
101            "syscall_config",
102            "system_config",
103            "program_types",
104            "map_types",
105            "helpers",
106            "misc",
107        ]
108
109        for tc in test_cases:
110            # Check if the result has all expected keys.
111            self.assertCountEqual(tc.keys(), expected_keys)
112            # Check if unexpected helpers are not included in helpers probes
113            # result.
114            for helpers in tc["helpers"].values():
115                for unexpected_helper in unexpected_helpers:
116                    self.assertNotIn(unexpected_helper, helpers)
117
118    def test_feature_kernel_full(self):
119        test_cases = [
120            bpftool_json(["feature", "probe", "kernel", "full"]),
121            bpftool_json(["feature", "probe", "full"]),
122        ]
123        expected_helpers = DMESG_EMITTING_HELPERS
124
125        for tc in test_cases:
126            # Check if expected helpers are included at least once in any
127            # helpers list for any program type. Unfortunately we cannot assume
128            # that they will be included in all program types or a specific
129            # subset of programs. It depends on the kernel version and
130            # configuration.
131            found_helpers = False
132
133            for helpers in tc["helpers"].values():
134                if all(expected_helper in helpers
135                       for expected_helper in expected_helpers):
136                    found_helpers = True
137                    break
138
139            self.assertTrue(found_helpers)
140
141    def test_feature_kernel_full_vs_not_full(self):
142        full_res = bpftool_json(["feature", "probe", "full"])
143        not_full_res = bpftool_json(["feature", "probe"])
144        not_full_set = set()
145        full_set = set()
146
147        for helpers in full_res["helpers"].values():
148            for helper in helpers:
149                full_set.add(helper)
150
151        for helpers in not_full_res["helpers"].values():
152            for helper in helpers:
153                not_full_set.add(helper)
154
155        self.assertCountEqual(full_set - not_full_set,
156                              set(DMESG_EMITTING_HELPERS))
157        self.assertCountEqual(not_full_set - full_set, set())
158
159    def test_feature_macros(self):
160        expected_patterns = [
161            r"/\*\*\* System call availability \*\*\*/",
162            r"#define HAVE_BPF_SYSCALL",
163            r"/\*\*\* eBPF program types \*\*\*/",
164            r"#define HAVE.*PROG_TYPE",
165            r"/\*\*\* eBPF map types \*\*\*/",
166            r"#define HAVE.*MAP_TYPE",
167            r"/\*\*\* eBPF helper functions \*\*\*/",
168            r"#define HAVE.*HELPER",
169            r"/\*\*\* eBPF misc features \*\*\*/",
170        ]
171
172        res = bpftool(["feature", "probe", "macros"])
173        for pattern in expected_patterns:
174            self.assertRegex(res, pattern)
175