tests/subsystem_test.c

   1 /*
   2 * Copyright (c) 2019 Apple Inc. All rights reserved.
   3 *
   4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5 *
   6 * This file contains Original Code and/or Modifications of Original Code
   7 * as defined in and that are subject to the Apple Public Source License
   8 * Version 2.0 (the 'License'). You may not use this file except in
   9 * compliance with the License. The rights granted to you under the License
  10 * may not be used to create, or enable the creation or redistribution of,
  11 * unlawful or unlicensed copies of an Apple operating system, or to
  12 * circumvent, violate, or enable the circumvention or violation of, any
  13 * terms of an Apple operating system software license agreement.
  14 *
  15 * Please obtain a copy of the License at
  16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17 *
  18 * The Original Code and all software distributed under the License are
  19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23 * Please see the License for the specific language governing rights and
  24 * limitations under the License.
  25 *
  26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27 */
  28
  29 #include <fcntl.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <spawn.h>
  33 #include <spawn_private.h>
  34 #include <sys/wait.h>
  35 #include <unistd.h>
  36 #include "subsystem_test.h"
  37
  38 #include <darwintest.h>
  39 #include <darwintest_utils.h>
  40
  41 #define RANDOM_STRING_LEN 33
  42
  43 #define HELPER_PATH "./subsystem_test_helper"
  44
  45 /* Create the given file.  Doesn't create directories. */
  46 static bool
  47 _create_file(char * const filepath)
  48 {
  49     bool success = false;
  50     int fd = open(filepath, O_CREAT | O_EXCL, 0666);
  51
  52     if (fd >= 0) {
  53         close(fd);
  54         success = true;
  55     }
  56
  57     return success;
  58 }
  59
  60 /* Fills the given buffer with a random alphanumeric string. */
  61 static void
  62 _generate_random_string(char * buf, size_t buf_len)
  63 {
  64
  65     static char _alphanumeric[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
  66     size_t cur_byte = 0;
  67
  68     if (buf_len == 0) {
  69         return;
  70     }
  71
  72     for (cur_byte = 0; ((buf_len - cur_byte) > 1); cur_byte++) {
  73         buf[cur_byte] = _alphanumeric[rand() % (sizeof(_alphanumeric) - 1)];
  74     }
  75
  76     buf[cur_byte] = 0;
  77
  78     return;
  79 }
  80
  81 /* Compares the contents of the given file with the buffer. */
  82 static int
  83 _check_file_contents(char * const filepath, char * const buf, size_t buf_len)
  84 {
  85     int result = 1;
  86     int fd = -1;
  87     char file_buf[buf_len];
  88
  89     fd = open(filepath, O_RDONLY);
  90
  91     if (fd >= 0) {
  92         read(fd, file_buf, buf_len);
  93         close(fd);
  94
  95         result = memcmp(buf, file_buf, buf_len);
  96     }
  97
  98     return result;
  99 }
 100
 101 /* Spawn with the given args and attributes, and waits for the child. */
 102 static int
 103 _spawn_and_wait(char ** args, posix_spawnattr_t *attr)
 104 {
 105     int pid;
 106     int status;
 107
 108     if (posix_spawn(&pid, args[0], NULL, attr, args, NULL)) {
 109         return -1;
 110     }
 111     if (waitpid(pid, &status, 0) < 0) {
 112         return -1;
 113     }
 114
 115     if (WIFEXITED(status) && (WEXITSTATUS(status) == 0)) {
 116         return 0;
 117     }
 118
 119     return -1;
 120 }
 121
 122 T_GLOBAL_META(T_META_RUN_CONCURRENTLY(true));
 123
 124 T_DECL(subsystem,
 125     "Test the subsystem-related functions",
 126     T_META_CHECK_LEAKS(false))
 127 {
 128     int result = 0;
 129     int pid = 0;
 130     posix_spawnattr_t attr = NULL;
 131
 132     char file_name[RANDOM_STRING_LEN];
 133     char overflow_file_name[PATH_MAX - RANDOM_STRING_LEN];
 134     char subsystem_name[RANDOM_STRING_LEN];
 135
 136     char file_path[PATH_MAX];
 137     char subsystem_path[PATH_MAX];
 138     char subsystem_tmp_path[PATH_MAX];
 139     char subsystem_file_path[PATH_MAX];
 140     char overflow_file_path[PATH_MAX];
 141     char overflow_subsystem_file_path[PATH_MAX];
 142
 143     char * args[] = { HELPER_PATH, HELPER_BEHAVIOR_NOT_SET, overflow_file_path, "", NULL};
 144
 145     /* Seed rand() from /dev/random, and generate our random file names. */
 146     sranddev();
 147     _generate_random_string(file_name, sizeof(file_name));
 148     _generate_random_string(overflow_file_name, sizeof(overflow_file_name));
 149     _generate_random_string(subsystem_name, sizeof(subsystem_name));
 150
 151     /* Generate pathnames. */
 152     sprintf(file_path, "/tmp/%s", file_name);
 153     sprintf(overflow_file_path, "/tmp/%s", overflow_file_name);
 154     sprintf(subsystem_path, "/tmp/%s", subsystem_name);
 155     sprintf(subsystem_tmp_path, "%s/tmp", subsystem_path);
 156     sprintf(subsystem_file_path, "%s/%s", subsystem_path, file_path);
 157
 158     /*
 159      * Initial setup for the test; we'll need our subsystem
 160      * directory and a /tmp/ for it.
 161      */
 162     T_QUIET; T_ASSERT_POSIX_SUCCESS(mkdir(subsystem_path, 0777), "Create subsystem directory");
 163     T_QUIET; T_ASSERT_POSIX_SUCCESS(mkdir(subsystem_tmp_path, 0777), "Create subsystem /tmp/ directory");
 164     T_QUIET; T_ASSERT_POSIX_SUCCESS(posix_spawnattr_init(&attr), "posix_spawnattr_init");
 165
 166     /* open and stat with no subsystem. */
 167     args[1] = HELPER_BEHAVIOR_OPEN_AND_WRITE;
 168     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), -1, "open_with_subsystem with no subsystem");
 169
 170     args[1] = HELPER_BEHAVIOR_STAT_NONE;
 171     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "stat_with_subsystem with no subsystem");
 172
 173     T_QUIET; T_ASSERT_POSIX_SUCCESS(posix_spawnattr_set_subsystem_root_path_np(&attr, subsystem_path), "Set subsystem root path");
 174
 175     /*
 176      * Test behavior when there is no main file and the subsystem
 177      * file path is longer than PATH_MAX.
 178      */
 179     args[1] = HELPER_BEHAVIOR_OPEN_OVERFLOW;
 180
 181     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "open_with_subsystem with overflow");
 182
 183     args[1] = HELPER_BEHAVIOR_STAT_OVERFLOW;
 184
 185     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "stat_with_subsystem with overflow");
 186
 187     /* O_CREAT is strictly disallowed; test this. */
 188     args[1] = HELPER_BEHAVIOR_OPEN_O_CREAT;
 189     args[2] = file_path;
 190
 191     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "open_with_subsystem with O_CREAT");
 192
 193     /*
 194      * Test valid use of open_with_subsystem and
 195      * stat_with_subsystem.  We've got 4 cases to
 196      * test: neither file exists, the subsystem
 197      * file exists, both files exist, and the
 198      * main fail exists.
 199      */
 200     /* Neither file exists. */
 201     args[1] = HELPER_BEHAVIOR_OPEN_AND_WRITE;
 202
 203     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), -1, "open_with_subsystem with no file");
 204
 205     args[1] = HELPER_BEHAVIOR_STAT_NONE;
 206
 207     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "stat_with_subsystem with no file");
 208
 209     /* Subsystem file exists. */
 210     T_QUIET; T_ASSERT_TRUE(_create_file(subsystem_file_path), "Create subsystem file");
 211
 212     args[1] = HELPER_BEHAVIOR_OPEN_AND_WRITE;
 213     args[3] = "with subsystem file";
 214
 215     result = _spawn_and_wait(args, &attr);
 216
 217     if (!result) {
 218         result = _check_file_contents(subsystem_file_path, args[3], strlen(args[3]));
 219     }
 220
 221     T_ASSERT_EQ_INT(result, 0, "open_with_subsystem with subsystem file");
 222
 223     args[1] = HELPER_BEHAVIOR_STAT_NOT_MAIN;
 224
 225     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "stat_with_subsystem with subsystem file");
 226
 227     /* Both files exist. */
 228     T_QUIET; T_ASSERT_TRUE(_create_file(file_path), "Create main file");
 229
 230     args[1] = HELPER_BEHAVIOR_OPEN_AND_WRITE;
 231     args[3] = "with both files";
 232
 233     result = _spawn_and_wait(args, &attr);
 234
 235     if (!result) {
 236         result = _check_file_contents(file_path, args[3], strlen(args[3]));
 237     }
 238
 239     T_ASSERT_EQ_INT(result, 0, "open_with_subsystem with both files");
 240
 241     args[1] = HELPER_BEHAVIOR_STAT_MAIN;
 242
 243     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "stat_with_subsystem with both files");
 244
 245     /* Main file exists. */
 246     T_QUIET; T_EXPECT_POSIX_SUCCESS(unlink(subsystem_file_path), "Delete subsystem file");
 247
 248     args[1] = HELPER_BEHAVIOR_OPEN_AND_WRITE;
 249     args[3] = "with main file";
 250
 251     result = _spawn_and_wait(args, &attr);
 252
 253     if (!result) {
 254         result = _check_file_contents(file_path, args[3], strlen(args[3]));
 255     }
 256
 257     T_ASSERT_EQ_INT(result, 0, "open_with_subsystem with main file");
 258
 259     args[1] = HELPER_BEHAVIOR_STAT_MAIN;
 260
 261     T_ASSERT_EQ_INT(_spawn_and_wait(args, &attr), 0, "stat_with_subsystem with main file");
 262
 263     /* We're done; clean everything up. */
 264     T_QUIET; T_EXPECT_POSIX_SUCCESS(unlink(file_path), "Delete main file");
 265     T_QUIET; T_EXPECT_POSIX_SUCCESS(rmdir(subsystem_tmp_path), "Remove subsystem /tmp/ directory");
 266     T_QUIET; T_EXPECT_POSIX_SUCCESS(rmdir(subsystem_path), "Remove subsystem directory");
 267     T_QUIET; T_ASSERT_POSIX_SUCCESS(posix_spawnattr_destroy(&attr), "posix_spawnattr_destroy");
 268 }