Commit d83d8230 authored by Alexis Lothoré (eBPF Foundation)'s avatar Alexis Lothoré (eBPF Foundation) Committed by Martin KaFai Lau
Browse files

selftests/bpf: convert test_dev_cgroup to test_progs 



test_dev_cgroup is defined as a standalone test program, and so is not
executed in CI.

Convert it to test_progs framework so it is tested automatically in CI, and
remove the old test. In order to be able to run it in test_progs, /dev/null
must remain usable, so change the new test to test operations on devices
1:3 as valid, and operations on devices 1:5 (/dev/zero) as invalid.

Reviewed-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Signed-off-by: default avatarAlexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
Link: https://lore.kernel.org/r/20240731-convert_dev_cgroup-v4-2-849425d90de6@bootlin.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent ba6a9018

tools/testing/selftests/bpf/.gitignore

+0 −1
Original line number Diff line number Diff line
@@ -9,7 +9,6 @@ test_lpm_map 
test_tag

FEATURE-DUMP.libbpf

fixdep

test_dev_cgroup

/test_progs

/test_progs-no_alu32

/test_progs-bpf_gcc

tools/testing/selftests/bpf/Makefile

+0 −2
Original line number Diff line number Diff line
@@ -67,7 +67,6 @@ endif 


# Order correspond to 'make run_tests' order

TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \

	test_dev_cgroup \

	test_sock test_sockmap get_cgroup_id_user \

	test_cgroup_storage \

	test_tcpnotify_user test_sysctl \
@@ -292,7 +291,6 @@ JSON_WRITER := $(OUTPUT)/json_writer.o 
CAP_HELPERS	:= $(OUTPUT)/cap_helpers.o

NETWORK_HELPERS := $(OUTPUT)/network_helpers.o



$(OUTPUT)/test_dev_cgroup: $(CGROUP_HELPERS) $(TESTING_HELPERS)

$(OUTPUT)/test_skb_cgroup_id_user: $(CGROUP_HELPERS) $(TESTING_HELPERS)

$(OUTPUT)/test_sock: $(CGROUP_HELPERS) $(TESTING_HELPERS)

$(OUTPUT)/test_sockmap: $(CGROUP_HELPERS) $(TESTING_HELPERS)

tools/testing/selftests/bpf/prog_tests/cgroup_dev.c

0 → 100644
+121 −0
Original line number Diff line number Diff line 
// 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);



cleanup_progs:

	dev_cgroup__destroy(skel);

cleanup_cgroup:

	cleanup_cgroup_environment();

}

tools/testing/selftests/bpf/test_dev_cgroup.c

deleted100644 → 0
+0 −85
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright (c) 2017 Facebook

 */



#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <assert.h>

#include <sys/time.h>



#include <linux/bpf.h>

#include <bpf/bpf.h>

#include <bpf/libbpf.h>



#include "cgroup_helpers.h"

#include "testing_helpers.h"



#define DEV_CGROUP_PROG "./dev_cgroup.bpf.o"



#define TEST_CGROUP "/test-bpf-based-device-cgroup/"



int main(int argc, char **argv)

{

	struct bpf_object *obj;

	int error = EXIT_FAILURE;

	int prog_fd, cgroup_fd;

	__u32 prog_cnt;



	/* Use libbpf 1.0 API mode */

	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);



	if (bpf_prog_test_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE,

			  &obj, &prog_fd)) {

		printf("Failed to load DEV_CGROUP program\n");

		goto out;

	}



	cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);

	if (cgroup_fd < 0) {

		printf("Failed to create test cgroup\n");

		goto out;

	}



	/* Attach bpf program */

	if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_DEVICE, 0)) {

		printf("Failed to attach DEV_CGROUP program");

		goto err;

	}



	if (bpf_prog_query(cgroup_fd, BPF_CGROUP_DEVICE, 0, NULL, NULL,

			   &prog_cnt)) {

		printf("Failed to query attached programs");

		goto err;

	}



	/* All operations with /dev/null and /dev/urandom are allowed,

	 * everything else is forbidden.

	 */

	assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0);

	assert(system("mknod /tmp/test_dev_cgroup_zero c 1 5"));

	assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0);



	/* /dev/null is whitelisted */

	assert(system("rm -f /tmp/test_dev_cgroup_null") == 0);

	assert(system("mknod /tmp/test_dev_cgroup_null c 1 3") == 0);

	assert(system("rm -f /tmp/test_dev_cgroup_null") == 0);



	assert(system("dd if=/dev/urandom of=/dev/null count=64") == 0);



	/* src is allowed, target is forbidden */

	assert(system("dd if=/dev/urandom of=/dev/full count=64"));



	/* src is forbidden, target is allowed */

	assert(system("dd if=/dev/random of=/dev/null count=64"));



	error = 0;

	printf("test_dev_cgroup:PASS\n");



err:

	cleanup_cgroup_environment();



out:

	return error;

}