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| author | Martin KaFai Lau <martin.lau@kernel.org> | 2024-07-31 10:00:20 -0700 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2024-07-31 10:00:30 -0700 |
| commit | b7ea631b9a79a85eee335fc5fab84108005d4f60 (patch) | |
| tree | 577caa5c25393d49c731bb97a39727748cef637f /tools/testing/selftests/bpf/prog_tests | |
| parent | 92cc2456e9775dc4333fb4aa430763ae4ac2f2d9 (diff) | |
| parent | 84cdbff4a93501b7199f0d2f1150961ee95c8582 (diff) | |
Merge branch 'selftests/bpf: convert test_dev_cgroup to test_progs'
Alexis Lothoré (eBPF Foundation) says:
====================
Hello,
this small series aims to integrate test_dev_cgroup in test_progs so it
could be run automatically in CI. The new version brings a few differences
with the current one:
- test now uses directly syscalls instead of wrapping commandline tools
into system() calls
- test_progs manipulates /dev/null (eg: redirecting test logs into it), so
disabling access to it in the bpf program confuses the tests. To fix this,
the first commit modifies the bpf program to allow access to char devices
1:3 (/dev/null), and disable access to char devices 1:5 (/dev/zero)
- once test is converted, add a small subtest to also check for device type
interpretation (char or block)
- paths used in mknod tests are now in /dev instead of /tmp: due to the CI
runner organisation and mountpoints manipulations, trying to create nodes
in /tmp leads to errors unrelated to the test (ie, mknod calls refused by
kernel, not the bpf program). I don't understand exactly the root cause
at the deepest point (all I see in CI is an -ENXIO error on mknod when trying to
create the node in tmp, and I can not make sense out of it neither
replicate it locally), so I would gladly take inputs from anyone more
educated than me about this.
The new test_progs part has been tested in a local qemu environment as well
as in upstream CI:
./test_progs -a cgroup_dev
47/1 cgroup_dev/allow-mknod:OK
47/2 cgroup_dev/allow-read:OK
47/3 cgroup_dev/allow-write:OK
47/4 cgroup_dev/deny-mknod:OK
47/5 cgroup_dev/deny-read:OK
47/6 cgroup_dev/deny-write:OK
47/7 cgroup_dev/deny-mknod-wrong-type:OK
47 cgroup_dev:OK
Summary: 1/7 PASSED, 0 SKIPPED, 0 FAILED
---
Changes in v4:
- Fix mixup between ret and errno by testing both
- Properly apply ack tag from Stanislas
- Link to v3: https://lore.kernel.org/r/20240730-convert_dev_cgroup-v3-0-93e573b74357@bootlin.com
Changes in v3:
- delete mknod file only if it has been created
- use bpf_program__attach_cgroup() instead of bpf_prog_attach
- reorganize subtests order
- collect review/ack tags from Alan and Stanislas
- Link to v2: https://lore.kernel.org/r/20240729-convert_dev_cgroup-v2-0-4c1fc0520545@bootlin.com
Changes in v2:
- directly pass expected ret code to subtests instead of boolean pass/not
pass
- fix faulty fd check in subtest expected to fail on open
- fix wrong subtest name
- pass test buffer and corresponding size to read/write subtests
- use correct series prefix
- Link to v1: https://lore.kernel.org/r/20240725-convert_dev_cgroup-v1-0-2c8cbd487c44@bootlin.com
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/cgroup_dev.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c b/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c new file mode 100644 index 000000000000..5ab7547e38c0 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_dev.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <sys/stat.h> +#include <sys/sysmacros.h> +#include <errno.h> +#include "test_progs.h" +#include "cgroup_helpers.h" +#include "dev_cgroup.skel.h" + +#define TEST_CGROUP "/test-bpf-based-device-cgroup/" +#define TEST_BUFFER_SIZE 64 + +static void test_mknod(const char *path, mode_t mode, int dev_major, + int dev_minor, int expected_ret, int expected_errno) +{ + int ret; + + unlink(path); + ret = mknod(path, mode, makedev(dev_major, dev_minor)); + ASSERT_EQ(ret, expected_ret, "mknod"); + if (expected_ret) + ASSERT_EQ(errno, expected_errno, "mknod errno"); + else + unlink(path); +} + +static void test_read(const char *path, char *buf, int buf_size, + int expected_ret, int expected_errno) +{ + int ret, fd; + + fd = open(path, O_RDONLY); + + /* A bare open on unauthorized device should fail */ + if (expected_ret < 0) { + ASSERT_EQ(fd, expected_ret, "open ret for read"); + ASSERT_EQ(errno, expected_errno, "open errno for read"); + if (fd >= 0) + close(fd); + return; + } + + if (!ASSERT_OK_FD(fd, "open ret for read")) + return; + + ret = read(fd, buf, buf_size); + ASSERT_EQ(ret, expected_ret, "read"); + + close(fd); +} + +static void test_write(const char *path, char *buf, int buf_size, + int expected_ret, int expected_errno) +{ + int ret, fd; + + fd = open(path, O_WRONLY); + + /* A bare open on unauthorized device should fail */ + if (expected_ret < 0) { + ASSERT_EQ(fd, expected_ret, "open ret for write"); + ASSERT_EQ(errno, expected_errno, "open errno for write"); + if (fd >= 0) + close(fd); + return; + } + + if (!ASSERT_OK_FD(fd, "open ret for write")) + return; + + ret = write(fd, buf, buf_size); + ASSERT_EQ(ret, expected_ret, "write"); + + close(fd); +} + +void test_cgroup_dev(void) +{ + char buf[TEST_BUFFER_SIZE] = "some random test data"; + struct dev_cgroup *skel; + int cgroup_fd; + + cgroup_fd = cgroup_setup_and_join(TEST_CGROUP); + if (!ASSERT_OK_FD(cgroup_fd, "cgroup switch")) + return; + + skel = dev_cgroup__open_and_load(); + if (!ASSERT_OK_PTR(skel, "load program")) + goto cleanup_cgroup; + + skel->links.bpf_prog1 = + bpf_program__attach_cgroup(skel->progs.bpf_prog1, cgroup_fd); + if (!ASSERT_OK_PTR(skel->links.bpf_prog1, "attach_program")) + goto cleanup_progs; + + if (test__start_subtest("allow-mknod")) + test_mknod("/dev/test_dev_cgroup_null", S_IFCHR, 1, 3, 0, 0); + + if (test__start_subtest("allow-read")) + test_read("/dev/urandom", buf, TEST_BUFFER_SIZE, + TEST_BUFFER_SIZE, 0); + + if (test__start_subtest("allow-write")) + test_write("/dev/null", buf, TEST_BUFFER_SIZE, + TEST_BUFFER_SIZE, 0); + + if (test__start_subtest("deny-mknod")) + test_mknod("/dev/test_dev_cgroup_zero", S_IFCHR, 1, 5, -1, + EPERM); + + if (test__start_subtest("deny-read")) + test_read("/dev/random", buf, TEST_BUFFER_SIZE, -1, EPERM); + + if (test__start_subtest("deny-write")) + test_write("/dev/zero", buf, TEST_BUFFER_SIZE, -1, EPERM); + + if (test__start_subtest("deny-mknod-wrong-type")) + test_mknod("/dev/test_dev_cgroup_block", S_IFBLK, 1, 3, -1, + EPERM); + +cleanup_progs: + dev_cgroup__destroy(skel); +cleanup_cgroup: + cleanup_cgroup_environment(); +} |