Remove all calls of print_end_then_start_section function and for loops out from the do_probe function. Instead, provide separate functions for each section (like i.e. section_helpers) which are called in do_probe. This change is motivated by better readability.

Signed-off-by: Michal Rostecki mrostecki@opensuse.org --- tools/bpf/bpftool/feature.c | 219 +++++++++++++++++++++--------------- 1 file changed, 126 insertions(+), 93 deletions(-)

diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c index 941873d778d8..345e4a2b4f53 100644 --- a/tools/bpf/bpftool/feature.c +++ b/tools/bpf/bpftool/feature.c @@ -112,18 +112,12 @@ print_start_section(const char *json_title, const char *plain_title, } }

-static void -print_end_then_start_section(const char *json_title, const char *plain_title, - const char *define_comment, - const char *define_prefix) +static void print_end_section(void) { if (json_output) jsonw_end_object(json_wtr); else printf("\n"); - - print_start_section(json_title, plain_title, define_comment, - define_prefix); }

/* Probing functions */ @@ -584,13 +578,130 @@ probe_large_insn_limit(const char *define_prefix, __u32 ifindex) res, define_prefix); }

+static void +section_system_config(enum probe_component target, const char *define_prefix) +{ + switch (target) { + case COMPONENT_KERNEL: + case COMPONENT_UNSPEC: + if (define_prefix) + break; + + print_start_section("system_config", + "Scanning system configuration...", + NULL, /* define_comment never used here */ + NULL); /* define_prefix always NULL here */ + if (check_procfs()) { + probe_unprivileged_disabled(); + probe_jit_enable(); + probe_jit_harden(); + probe_jit_kallsyms(); + probe_jit_limit(); + } else { + p_info("/* procfs not mounted, skipping related probes */"); + } + probe_kernel_image_config(); + print_end_section(); + break; + default: + break; + } +} + +static bool section_syscall_config(const char *define_prefix) +{ + bool res; + + print_start_section("syscall_config", + "Scanning system call availability...", + "/*** System call availability ***/", + define_prefix); + res = probe_bpf_syscall(define_prefix); + print_end_section(); + + return res; +} + +static void +section_program_types(bool *supported_types, const char *define_prefix, + __u32 ifindex) +{ + unsigned int i; + + print_start_section("program_types", + "Scanning eBPF program types...", + "/*** eBPF program types ***/", + define_prefix); + + for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++) + probe_prog_type(i, supported_types, define_prefix, ifindex); + + print_end_section(); +} + +static void section_map_types(const char *define_prefix, __u32 ifindex) +{ + unsigned int i; + + print_start_section("map_types", + "Scanning eBPF map types...", + "/*** eBPF map types ***/", + define_prefix); + + for (i = BPF_MAP_TYPE_UNSPEC + 1; i < map_type_name_size; i++) + probe_map_type(i, define_prefix, ifindex); + + print_end_section(); +} + +static void +section_helpers(bool *supported_types, const char *define_prefix, __u32 ifindex) +{ + unsigned int i; + + print_start_section("helpers", + "Scanning eBPF helper functions...", + "/*** eBPF helper functions ***/", + define_prefix); + + if (define_prefix) + printf("/*\n" + " * Use %sHAVE_PROG_TYPE_HELPER(prog_type_name, helper_name)\n" + " * to determine if <helper_name> is available for <prog_type_name>,\n" + " * e.g.\n" + " * #if %sHAVE_PROG_TYPE_HELPER(xdp, bpf_redirect)\n" + " * // do stuff with this helper\n" + " * #elif\n" + " * // use a workaround\n" + " * #endif\n" + " */\n" + "#define %sHAVE_PROG_TYPE_HELPER(prog_type, helper) \\n" + " %sBPF__PROG_TYPE_ ## prog_type ## __HELPER_ ## helper\n", + define_prefix, define_prefix, define_prefix, + define_prefix); + for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++) + probe_helpers_for_progtype(i, supported_types[i], + define_prefix, ifindex); + + print_end_section(); +} + +static void section_misc(const char *define_prefix, __u32 ifindex) +{ + print_start_section("misc", + "Scanning miscellaneous eBPF features...", + "/*** eBPF misc features ***/", + define_prefix); + probe_large_insn_limit(define_prefix, ifindex); + print_end_section(); +} + static int do_probe(int argc, char **argv) { enum probe_component target = COMPONENT_UNSPEC; const char *define_prefix = NULL; bool supported_types[128] = {}; __u32 ifindex = 0; - unsigned int i; char *ifname;

/* Detection assumes user has sufficient privileges (CAP_SYS_ADMIN). @@ -658,97 +769,19 @@ static int do_probe(int argc, char **argv) jsonw_start_object(json_wtr); }

- switch (target) { - case COMPONENT_KERNEL: - case COMPONENT_UNSPEC: - if (define_prefix) - break; - - print_start_section("system_config", - "Scanning system configuration...", - NULL, /* define_comment never used here */ - NULL); /* define_prefix always NULL here */ - if (check_procfs()) { - probe_unprivileged_disabled(); - probe_jit_enable(); - probe_jit_harden(); - probe_jit_kallsyms(); - probe_jit_limit(); - } else { - p_info("/* procfs not mounted, skipping related probes */"); - } - probe_kernel_image_config(); - if (json_output) - jsonw_end_object(json_wtr); - else - printf("\n"); - break; - default: - break; - } - - print_start_section("syscall_config", - "Scanning system call availability...", - "/*** System call availability ***/", - define_prefix); - - if (!probe_bpf_syscall(define_prefix)) + section_system_config(target, define_prefix); + if (!section_syscall_config(define_prefix)) /* bpf() syscall unavailable, don't probe other BPF features */ goto exit_close_json; - - print_end_then_start_section("program_types", - "Scanning eBPF program types...", - "/*** eBPF program types ***/", - define_prefix); - - for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++) - probe_prog_type(i, supported_types, define_prefix, ifindex); - - print_end_then_start_section("map_types", - "Scanning eBPF map types...", - "/*** eBPF map types ***/", - define_prefix); - - for (i = BPF_MAP_TYPE_UNSPEC + 1; i < map_type_name_size; i++) - probe_map_type(i, define_prefix, ifindex); - - print_end_then_start_section("helpers", - "Scanning eBPF helper functions...", - "/*** eBPF helper functions ***/", - define_prefix); - - if (define_prefix) - printf("/*\n" - " * Use %sHAVE_PROG_TYPE_HELPER(prog_type_name, helper_name)\n" - " * to determine if <helper_name> is available for <prog_type_name>,\n" - " * e.g.\n" - " * #if %sHAVE_PROG_TYPE_HELPER(xdp, bpf_redirect)\n" - " * // do stuff with this helper\n" - " * #elif\n" - " * // use a workaround\n" - " * #endif\n" - " */\n" - "#define %sHAVE_PROG_TYPE_HELPER(prog_type, helper) \\n" - " %sBPF__PROG_TYPE_ ## prog_type ## __HELPER_ ## helper\n", - define_prefix, define_prefix, define_prefix, - define_prefix); - for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++) - probe_helpers_for_progtype(i, supported_types[i], - define_prefix, ifindex); - - print_end_then_start_section("misc", - "Scanning miscellaneous eBPF features...", - "/*** eBPF misc features ***/", - define_prefix); - probe_large_insn_limit(define_prefix, ifindex); + section_program_types(supported_types, define_prefix, ifindex); + section_map_types(define_prefix, ifindex); + section_helpers(supported_types, define_prefix, ifindex); + section_misc(define_prefix, ifindex);

exit_close_json: - if (json_output) { - /* End current "section" of probes */ - jsonw_end_object(json_wtr); + if (json_output) /* End root object */ jsonw_end_object(json_wtr); - }

return 0; }

Update documentation of "bpftool feature" command with information about new arguments: "full".

Signed-off-by: Michal Rostecki mrostecki@opensuse.org --- .../bpftool/Documentation/bpftool-feature.rst | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/tools/bpf/bpftool/Documentation/bpftool-feature.rst b/tools/bpf/bpftool/Documentation/bpftool-feature.rst index 4d08f35034a2..b04156cfd7a3 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-feature.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-feature.rst @@ -19,19 +19,24 @@ SYNOPSIS FEATURE COMMANDS ================

-| **bpftool** **feature probe** [*COMPONENT*] [**macros** [**prefix** *PREFIX*]] +| **bpftool** **feature probe** [*COMPONENT*] [**full**] [**macros** [**prefix** *PREFIX*]] | **bpftool** **feature help** | | *COMPONENT* := { **kernel** | **dev** *NAME* }

DESCRIPTION =========== - **bpftool feature probe** [**kernel**] [**macros** [**prefix** *PREFIX*]] + **bpftool feature probe** [**kernel**] [**full**] [**macros** [**prefix** *PREFIX*]] Probe the running kernel and dump a number of eBPF-related parameters, such as availability of the **bpf()** system call, JIT status, eBPF program types availability, eBPF helper functions availability, and more.

+ By default, bpftool **does not run probes** for + **bpf_probe_write_user**\ () and **bpf_trace_printk**() + helpers which print warnings to kernel logs. To enable them + and run all probes, the **full** keyword should be used. + If the **macros** keyword (but not the **-j** option) is passed, a subset of the output is dumped as a list of **#define** macros that are ready to be included in a C @@ -44,16 +49,12 @@ DESCRIPTION Keyword **kernel** can be omitted. If no probe target is specified, probing the kernel is the default behaviour.

- Note that when probed, some eBPF helpers (e.g. - **bpf_trace_printk**\ () or **bpf_probe_write_user**\ ()) may - print warnings to kernel logs. - - **bpftool feature probe dev** *NAME* [**macros** [**prefix** *PREFIX*]] + **bpftool feature probe dev** *NAME* [**full**] [**macros** [**prefix** *PREFIX*]] Probe network device for supported eBPF features and dump results to the console.

- The two keywords **macros** and **prefix** have the same - role as when probing the kernel. + The keywords **full**, **macros** and **prefix** have the + same role as when probing the kernel.

**bpftool feature help** Print short help message.

Add Python module with tests for "bpftool feature" command, which mainly checks whether the "full" option is working properly.

Signed-off-by: Michal Rostecki mrostecki@opensuse.org --- tools/testing/selftests/.gitignore | 5 +- tools/testing/selftests/bpf/Makefile | 3 +- tools/testing/selftests/bpf/test_bpftool.py | 178 ++++++++++++++++++++ tools/testing/selftests/bpf/test_bpftool.sh | 5 + 4 files changed, 189 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/bpf/test_bpftool.py create mode 100755 tools/testing/selftests/bpf/test_bpftool.sh

diff --git a/tools/testing/selftests/.gitignore b/tools/testing/selftests/.gitignore index 61df01cdf0b2..304fdf1a21dc 100644 --- a/tools/testing/selftests/.gitignore +++ b/tools/testing/selftests/.gitignore @@ -3,4 +3,7 @@ gpiogpio-hammer gpioinclude/ gpiolsgpio tpm2/SpaceTest.log -tpm2/*.pyc + +# Python bytecode and cache +__pycache__/ +*.py[cod] diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 50c63c21e6fd..2d7f5df33f04 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -62,7 +62,8 @@ TEST_PROGS := test_kmod.sh \ test_tc_tunnel.sh \ test_tc_edt.sh \ test_xdping.sh \ - test_bpftool_build.sh + test_bpftool_build.sh \ + test_bpftool.sh

TEST_PROGS_EXTENDED := with_addr.sh \ with_tunnels.sh \ diff --git a/tools/testing/selftests/bpf/test_bpftool.py b/tools/testing/selftests/bpf/test_bpftool.py new file mode 100644 index 000000000000..4fed2dc25c0a --- /dev/null +++ b/tools/testing/selftests/bpf/test_bpftool.py @@ -0,0 +1,178 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2020 SUSE LLC. + +import collections +import functools +import json +import os +import socket +import subprocess +import unittest + + +# Add the source tree of bpftool and /usr/local/sbin to PATH +cur_dir = os.path.dirname(os.path.realpath(__file__)) +bpftool_dir = os.path.abspath(os.path.join(cur_dir, "..", "..", "..", "..", + "tools", "bpf", "bpftool")) +os.environ["PATH"] = bpftool_dir + ":/usr/local/sbin:" + os.environ["PATH"] + + +class IfaceNotFoundError(Exception): + pass + + +class UnprivilegedUserError(Exception): + pass + + +def _bpftool(args, json=True): + _args = ["bpftool"] + if json: + _args.append("-j") + _args.extend(args) + + return subprocess.check_output(_args) + + +def bpftool(args): + return _bpftool(args, json=False).decode("utf-8") + + +def bpftool_json(args): + res = _bpftool(args) + return json.loads(res) + + +def get_default_iface(): + for iface in socket.if_nameindex(): + if iface[1] != "lo": + return iface[1] + raise IfaceNotFoundError("Could not find any network interface to probe") + + +def default_iface(f): + @functools.wraps(f) + def wrapper(*args, **kwargs): + iface = get_default_iface() + return f(*args, iface, **kwargs) + return wrapper + + +class TestBpftool(unittest.TestCase): + @classmethod + def setUpClass(cls): + if os.getuid() != 0: + raise UnprivilegedUserError( + "This test suite needs root privileges") + + @default_iface + def test_feature_dev_json(self, iface): + unexpected_helpers = [ + "bpf_probe_write_user", + "bpf_trace_printk", + ] + expected_keys = [ + "syscall_config", + "program_types", + "map_types", + "helpers", + "misc", + ] + + res = bpftool_json(["feature", "probe", "dev", iface]) + # Check if the result has all expected keys. + self.assertCountEqual(res.keys(), expected_keys) + # Check if unexpected helpers are not included in helpers probes + # result. + for helpers in res["helpers"].values(): + for unexpected_helper in unexpected_helpers: + self.assertNotIn(unexpected_helper, helpers) + + def test_feature_kernel(self): + test_cases = [ + bpftool_json(["feature", "probe", "kernel"]), + bpftool_json(["feature", "probe"]), + bpftool_json(["feature"]), + ] + unexpected_helpers = [ + "bpf_probe_write_user", + "bpf_trace_printk", + ] + expected_keys = [ + "syscall_config", + "system_config", + "program_types", + "map_types", + "helpers", + "misc", + ] + + for tc in test_cases: + # Check if the result has all expected keys. + self.assertCountEqual(tc.keys(), expected_keys) + # Check if unexpected helpers are not included in helpers probes + # result. + for helpers in tc["helpers"].values(): + for unexpected_helper in unexpected_helpers: + self.assertNotIn(unexpected_helper, helpers) + + def test_feature_kernel_full(self): + test_cases = [ + bpftool_json(["feature", "probe", "kernel", "full"]), + bpftool_json(["feature", "probe", "full"]), + ] + expected_helpers = [ + "bpf_probe_write_user", + "bpf_trace_printk", + ] + + for tc in test_cases: + # Check if expected helpers are included at least once in any + # helpers list for any program type. Unfortunately we cannot assume + # that they will be included in all program types or a specific + # subset of programs. It depends on the kernel version and + # configuration. + found_helpers = False + + for helpers in tc["helpers"].values(): + if all(expected_helper in helpers + for expected_helper in expected_helpers): + found_helpers = True + break + + self.assertTrue(found_helpers) + + def test_feature_kernel_full_vs_not_full(self): + full_res = bpftool_json(["feature", "probe", "full"]) + not_full_res = bpftool_json(["feature", "probe"]) + not_full_set = set() + full_set = set() + + for helpers in full_res["helpers"].values(): + for helper in helpers: + full_set.add(helper) + + for helpers in not_full_res["helpers"].values(): + for helper in helpers: + not_full_set.add(helper) + + self.assertCountEqual(full_set - not_full_set, + {"bpf_probe_write_user", "bpf_trace_printk"}) + self.assertCountEqual(not_full_set - full_set, set()) + + def test_feature_macros(self): + expected_patterns = [ + r"/*** System call availability ***/", + r"#define HAVE_BPF_SYSCALL", + r"/*** eBPF program types ***/", + r"#define HAVE.*PROG_TYPE", + r"/*** eBPF map types ***/", + r"#define HAVE.*MAP_TYPE", + r"/*** eBPF helper functions ***/", + r"#define HAVE.*HELPER", + r"/*** eBPF misc features ***/", + ] + + res = bpftool(["feature", "probe", "macros"]) + for pattern in expected_patterns: + self.assertRegex(res, pattern) diff --git a/tools/testing/selftests/bpf/test_bpftool.sh b/tools/testing/selftests/bpf/test_bpftool.sh new file mode 100755 index 000000000000..66690778e36d --- /dev/null +++ b/tools/testing/selftests/bpf/test_bpftool.sh @@ -0,0 +1,5 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2020 SUSE LLC. + +python3 -m unittest -v test_bpftool.TestBpftool