126 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include <sys/stat.h>4#include <sys/sysmacros.h>5#include <errno.h>6#include "test_progs.h"7#include "cgroup_helpers.h"8#include "dev_cgroup.skel.h"9 10#define TEST_CGROUP "/test-bpf-based-device-cgroup/"11#define TEST_BUFFER_SIZE 6412 13static void test_mknod(const char *path, mode_t mode, int dev_major,14 int dev_minor, int expected_ret, int expected_errno)15{16 int ret;17 18 unlink(path);19 ret = mknod(path, mode, makedev(dev_major, dev_minor));20 ASSERT_EQ(ret, expected_ret, "mknod");21 if (expected_ret)22 ASSERT_EQ(errno, expected_errno, "mknod errno");23 else24 unlink(path);25}26 27static void test_read(const char *path, char *buf, int buf_size,28 int expected_ret, int expected_errno)29{30 int ret, fd;31 32 fd = open(path, O_RDONLY);33 34 /* A bare open on unauthorized device should fail */35 if (expected_ret < 0) {36 ASSERT_EQ(fd, expected_ret, "open ret for read");37 ASSERT_EQ(errno, expected_errno, "open errno for read");38 if (fd >= 0)39 close(fd);40 return;41 }42 43 if (!ASSERT_OK_FD(fd, "open ret for read"))44 return;45 46 ret = read(fd, buf, buf_size);47 ASSERT_EQ(ret, expected_ret, "read");48 49 close(fd);50}51 52static void test_write(const char *path, char *buf, int buf_size,53 int expected_ret, int expected_errno)54{55 int ret, fd;56 57 fd = open(path, O_WRONLY);58 59 /* A bare open on unauthorized device should fail */60 if (expected_ret < 0) {61 ASSERT_EQ(fd, expected_ret, "open ret for write");62 ASSERT_EQ(errno, expected_errno, "open errno for write");63 if (fd >= 0)64 close(fd);65 return;66 }67 68 if (!ASSERT_OK_FD(fd, "open ret for write"))69 return;70 71 ret = write(fd, buf, buf_size);72 ASSERT_EQ(ret, expected_ret, "write");73 74 close(fd);75}76 77void test_cgroup_dev(void)78{79 char buf[TEST_BUFFER_SIZE] = "some random test data";80 struct dev_cgroup *skel;81 int cgroup_fd;82 83 cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);84 if (!ASSERT_OK_FD(cgroup_fd, "cgroup switch"))85 return;86 87 skel = dev_cgroup__open_and_load();88 if (!ASSERT_OK_PTR(skel, "load program"))89 goto cleanup_cgroup;90 91 skel->links.bpf_prog1 =92 bpf_program__attach_cgroup(skel->progs.bpf_prog1, cgroup_fd);93 if (!ASSERT_OK_PTR(skel->links.bpf_prog1, "attach_program"))94 goto cleanup_progs;95 96 if (test__start_subtest("allow-mknod"))97 test_mknod("/dev/test_dev_cgroup_null", S_IFCHR, 1, 3, 0, 0);98 99 if (test__start_subtest("allow-read"))100 test_read("/dev/urandom", buf, TEST_BUFFER_SIZE,101 TEST_BUFFER_SIZE, 0);102 103 if (test__start_subtest("allow-write"))104 test_write("/dev/null", buf, TEST_BUFFER_SIZE,105 TEST_BUFFER_SIZE, 0);106 107 if (test__start_subtest("deny-mknod"))108 test_mknod("/dev/test_dev_cgroup_zero", S_IFCHR, 1, 5, -1,109 EPERM);110 111 if (test__start_subtest("deny-read"))112 test_read("/dev/random", buf, TEST_BUFFER_SIZE, -1, EPERM);113 114 if (test__start_subtest("deny-write"))115 test_write("/dev/zero", buf, TEST_BUFFER_SIZE, -1, EPERM);116 117 if (test__start_subtest("deny-mknod-wrong-type"))118 test_mknod("/dev/test_dev_cgroup_block", S_IFBLK, 1, 3, -1,119 EPERM);120 121cleanup_progs:122 dev_cgroup__destroy(skel);123cleanup_cgroup:124 cleanup_cgroup_environment();125}126