1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2017 Facebook 3 */ 4 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <string.h> 8 #include <errno.h> 9 #include <assert.h> 10 #include <sys/time.h> 11 12 #include <linux/bpf.h> 13 #include <bpf/bpf.h> 14 #include <bpf/libbpf.h> 15 16 #include "cgroup_helpers.h" 17 #include "testing_helpers.h" 18 #include "bpf_rlimit.h" 19 20 #define DEV_CGROUP_PROG "./dev_cgroup.o" 21 22 #define TEST_CGROUP "/test-bpf-based-device-cgroup/" 23 24 int main(int argc, char **argv) 25 { 26 struct bpf_object *obj; 27 int error = EXIT_FAILURE; 28 int prog_fd, cgroup_fd; 29 __u32 prog_cnt; 30 31 if (bpf_prog_test_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE, 32 &obj, &prog_fd)) { 33 printf("Failed to load DEV_CGROUP program\n"); 34 goto out; 35 } 36 37 cgroup_fd = cgroup_setup_and_join(TEST_CGROUP); 38 if (cgroup_fd < 0) { 39 printf("Failed to create test cgroup\n"); 40 goto out; 41 } 42 43 /* Attach bpf program */ 44 if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_DEVICE, 0)) { 45 printf("Failed to attach DEV_CGROUP program"); 46 goto err; 47 } 48 49 if (bpf_prog_query(cgroup_fd, BPF_CGROUP_DEVICE, 0, NULL, NULL, 50 &prog_cnt)) { 51 printf("Failed to query attached programs"); 52 goto err; 53 } 54 55 /* All operations with /dev/zero and and /dev/urandom are allowed, 56 * everything else is forbidden. 57 */ 58 assert(system("rm -f /tmp/test_dev_cgroup_null") == 0); 59 assert(system("mknod /tmp/test_dev_cgroup_null c 1 3")); 60 assert(system("rm -f /tmp/test_dev_cgroup_null") == 0); 61 62 /* /dev/zero is whitelisted */ 63 assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0); 64 assert(system("mknod /tmp/test_dev_cgroup_zero c 1 5") == 0); 65 assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0); 66 67 assert(system("dd if=/dev/urandom of=/dev/zero count=64") == 0); 68 69 /* src is allowed, target is forbidden */ 70 assert(system("dd if=/dev/urandom of=/dev/full count=64")); 71 72 /* src is forbidden, target is allowed */ 73 assert(system("dd if=/dev/random of=/dev/zero count=64")); 74 75 error = 0; 76 printf("test_dev_cgroup:PASS\n"); 77 78 err: 79 cleanup_cgroup_environment(); 80 81 out: 82 return error; 83 } 84