| 1 | /* |
| 2 | * spawn_persona.c |
| 3 | * Use new POSIX spawn attributes to create a new process in a persona |
| 4 | * |
| 5 | * Jeremy C. Andrus <jeremy_andrus@apple.com> |
| 6 | * |
| 7 | */ |
| 8 | #include <ctype.h> |
| 9 | #include <err.h> |
| 10 | #include <errno.h> |
| 11 | #include <inttypes.h> |
| 12 | #include <libgen.h> |
| 13 | #include <pthread.h> |
| 14 | #include <signal.h> |
| 15 | #include <stdio.h> |
| 16 | #include <stdlib.h> |
| 17 | #include <string.h> |
| 18 | #include <unistd.h> |
| 19 | #include <mach/mach.h> |
| 20 | #include <mach/task.h> |
| 21 | #include <mach/vm_param.h> |
| 22 | #include <sys/queue.h> |
| 23 | #include <sys/sysctl.h> |
| 24 | #include <sys/types.h> |
| 25 | |
| 26 | #include "persona_test.h" |
| 27 | |
| 28 | /* internal */ |
| 29 | #include <libproc.h> |
| 30 | #include <spawn_private.h> |
| 31 | #include <sys/persona.h> |
| 32 | #include <sys/proc_info.h> |
| 33 | #include <sys/spawn_internal.h> |
| 34 | |
| 35 | #define PERSONA_TEST_NAME "Persona Spawn" |
| 36 | #define PERSONA_TEST_VMAJOR 0 |
| 37 | #define PERSONA_TEST_VMINOR 1 |
| 38 | |
| 39 | static struct test_config { |
| 40 | int verbose; |
| 41 | int wait_for_children; |
| 42 | } g; |
| 43 | |
| 44 | |
| 45 | /* = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = |
| 46 | * |
| 47 | * Child Management |
| 48 | * |
| 49 | * = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = |
| 50 | */ |
| 51 | struct child { |
| 52 | TAILQ_ENTRY(child) sibling; |
| 53 | int pid; |
| 54 | }; |
| 55 | |
| 56 | static pthread_mutex_t g_child_mtx; |
| 57 | static TAILQ_HEAD(, child) g_children = TAILQ_HEAD_INITIALIZER(g_children); |
| 58 | static int g_nchildren = 0; |
| 59 | |
| 60 | static pid_t spawn_child(int argc, char **argv, struct persona_args *pa) |
| 61 | { |
| 62 | int ret; |
| 63 | uint32_t persona_flags = 0; |
| 64 | posix_spawnattr_t attr; |
| 65 | struct child *child = NULL; |
| 66 | extern char **environ; |
| 67 | |
| 68 | (void)argc; |
| 69 | |
| 70 | if (!pa) { |
| 71 | err_print("Invalid persona args!"); |
| 72 | return -ERR_SYSTEM; |
| 73 | } |
| 74 | |
| 75 | if (!pa->flags & PA_HAS_ID) { |
| 76 | err_print("No persona ID specified!"); |
| 77 | return -ERR_SYSTEM; |
| 78 | } |
| 79 | |
| 80 | if (g.verbose) { |
| 81 | dump_persona_args("Spawning new child with args: ", pa); |
| 82 | infov("\t prog: \"%s\"", argv[0]); |
| 83 | for (int i = 1; i < argc; i++) { |
| 84 | infov("\t arg[%d]: %s", i, argv[i]); |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | child = (struct child *)calloc(1, sizeof(*child)); |
| 89 | if (!child) { |
| 90 | err_print("No memory left :-("); |
| 91 | return -ERR_SYSTEM; |
| 92 | } |
| 93 | |
| 94 | ret = posix_spawnattr_init(&attr); |
| 95 | if (ret != 0) { |
| 96 | err_print("posix_spawnattr_init"); |
| 97 | ret = -ERR_SPAWN_ATTR; |
| 98 | goto out_err; |
| 99 | } |
| 100 | |
| 101 | if (pa->flags & PA_SHOULD_VERIFY) |
| 102 | persona_flags |= POSIX_SPAWN_PERSONA_FLAGS_VERIFY; |
| 103 | |
| 104 | if (pa->flags & PA_OVERRIDE) |
| 105 | persona_flags |= POSIX_SPAWN_PERSONA_FLAGS_OVERRIDE; |
| 106 | |
| 107 | ret = posix_spawnattr_set_persona_np(&attr, pa->kinfo.persona_id, persona_flags); |
| 108 | if (ret != 0) { |
| 109 | err_print("posix_spawnattr_set_persona_np failed!"); |
| 110 | ret = -ERR_SPAWN_ATTR; |
| 111 | goto out_err; |
| 112 | } |
| 113 | |
| 114 | if (pa->flags & PA_HAS_UID) { |
| 115 | ret = posix_spawnattr_set_persona_uid_np(&attr, pa->override_uid); |
| 116 | if (ret != 0) { |
| 117 | err_print("posix_spawnattr_set_persona_uid_np failed!"); |
| 118 | ret = -ERR_SPAWN_ATTR; |
| 119 | goto out_err; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | if (pa->flags & PA_HAS_GID) { |
| 124 | ret = posix_spawnattr_set_persona_gid_np(&attr, pa->kinfo.persona_gid); |
| 125 | if (ret != 0) { |
| 126 | err_print("posix_spawnattr_set_persona_gid_np failed!"); |
| 127 | ret = -ERR_SPAWN_ATTR; |
| 128 | goto out_err; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | ret = posix_spawn(&child->pid, argv[0], NULL, &attr, argv, environ); |
| 133 | if (ret != 0) { |
| 134 | err_print("posix_spawn (ret=%d)", ret); |
| 135 | ret = -ERR_SPAWN; |
| 136 | goto out_err; |
| 137 | } |
| 138 | |
| 139 | infov("\tspawned child PID: %d", child->pid); |
| 140 | |
| 141 | /* link the processes onto the global children list */ |
| 142 | pthread_mutex_lock(&g_child_mtx); |
| 143 | TAILQ_INSERT_TAIL(&g_children, child, sibling); |
| 144 | ++g_nchildren; |
| 145 | pthread_mutex_unlock(&g_child_mtx); |
| 146 | |
| 147 | posix_spawnattr_destroy(&attr); |
| 148 | return child->pid; |
| 149 | |
| 150 | out_err: |
| 151 | posix_spawnattr_destroy(&attr); |
| 152 | free(child); |
| 153 | return (pid_t)ret; |
| 154 | } |
| 155 | |
| 156 | |
| 157 | static int child_should_exit = 0; |
| 158 | |
| 159 | static void child_sighandler(int sig) |
| 160 | { |
| 161 | (void)sig; |
| 162 | dbg("PID: %d received sig %d", getpid(), sig); |
| 163 | child_should_exit = 1; |
| 164 | } |
| 165 | |
| 166 | static int child_main_loop(int argc, char **argv) |
| 167 | { |
| 168 | char ch; |
| 169 | sigset_t sigset; |
| 170 | int err = 0; |
| 171 | uid_t persona_id = 0; |
| 172 | struct kpersona_info kinfo; |
| 173 | int rval = 0; |
| 174 | |
| 175 | while ((ch = getopt(argc, argv, "vhER")) != -1) { |
| 176 | switch (ch) { |
| 177 | case 'v': |
| 178 | g.verbose = 1; |
| 179 | break; |
| 180 | case 'E': |
| 181 | child_should_exit = 1; |
| 182 | break; |
| 183 | case 'R': |
| 184 | rval = 1; |
| 185 | break; |
| 186 | case 'h': |
| 187 | case '?': |
| 188 | case ':': |
| 189 | default: |
| 190 | err("Invalid child process invocation."); |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | sigemptyset(&sigset); |
| 195 | sigaddset(&sigset, SIGINT); |
| 196 | sigaddset(&sigset, SIGHUP); |
| 197 | sigaddset(&sigset, SIGTERM); |
| 198 | sigaddset(&sigset, SIGABRT); |
| 199 | sigaddset(&sigset, SIGCHLD); |
| 200 | sigprocmask(SIG_UNBLOCK, &sigset, NULL); |
| 201 | |
| 202 | signal(SIGINT, child_sighandler); |
| 203 | signal(SIGHUP, child_sighandler); |
| 204 | signal(SIGTERM, child_sighandler); |
| 205 | signal(SIGABRT, child_sighandler); |
| 206 | signal(SIGCHLD, child_sighandler); |
| 207 | |
| 208 | err = kpersona_get(&persona_id); |
| 209 | |
| 210 | info("Child: PID:%d", getpid()); |
| 211 | info("Child: UID:%d, GID:%d", getuid(), getgid()); |
| 212 | info("Child: login:%s", getlogin()); |
| 213 | info("Child: Persona: %d (err:%d)", persona_id, err); |
| 214 | |
| 215 | kinfo.persona_info_version = PERSONA_INFO_V1; |
| 216 | err = kpersona_info(persona_id, &kinfo); |
| 217 | if (err == 0) |
| 218 | dump_kpersona("Child: kpersona_info", &kinfo); |
| 219 | else |
| 220 | info("Child: ERROR grabbing kpersona_info: %d", errno); |
| 221 | |
| 222 | if (child_should_exit) |
| 223 | return rval; |
| 224 | |
| 225 | infov("Child Sleeping!"); |
| 226 | while (!child_should_exit) |
| 227 | sleep(1); |
| 228 | |
| 229 | infov("Child exiting!"); |
| 230 | return rval; |
| 231 | } |
| 232 | |
| 233 | |
| 234 | /* = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = |
| 235 | * |
| 236 | * Main Entry Point |
| 237 | * |
| 238 | * = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = |
| 239 | */ |
| 240 | static void main_sighandler(int sig) |
| 241 | { |
| 242 | dbg("PID: %d received sig %d", getpid(), sig); |
| 243 | if (sig == SIGCHLD) { |
| 244 | --g_nchildren; |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | static void usage_main(const char *progname, int verbose) |
| 249 | { |
| 250 | const char *nm = basename((char *)progname); |
| 251 | |
| 252 | printf("%s v%d.%d\n", PERSONA_TEST_NAME, PERSONA_TEST_VMAJOR, PERSONA_TEST_VMINOR); |
| 253 | printf("usage: %s [-I id] [-V] [-u uid] [-g gid] [-vw] progname [args...]\n", nm); |
| 254 | printf(" Spawn a new process into a new or existing persona.\n"); |
| 255 | if (!verbose) |
| 256 | exit(1); |
| 257 | |
| 258 | printf("\t%-10s\tID of the persona\n", "-I id"); |
| 259 | printf("\t%-10s\tVerify persona parameters against existing persona (given by -I)\n", "-V"); |
| 260 | printf("\t%-10s\tOverride/verify the user ID of the new process\n", "-u uid"); |
| 261 | printf("\t%-10s\tOverride/verify the group ID of the new process\n", "-g gid"); |
| 262 | printf("\t%-10s\tBe verbose\n", "-v"); |
| 263 | printf("\t%-10s\tDo not wait for the child process\n", "-w"); |
| 264 | printf("\n"); |
| 265 | |
| 266 | exit(1); |
| 267 | } |
| 268 | |
| 269 | int main(int argc, char **argv) |
| 270 | { |
| 271 | char ch; |
| 272 | int ret; |
| 273 | |
| 274 | pthread_mutex_init(&g_child_mtx, NULL); |
| 275 | |
| 276 | /* |
| 277 | * Defaults |
| 278 | */ |
| 279 | g.verbose = 0; |
| 280 | g.wait_for_children = 1; |
| 281 | |
| 282 | if (argc > 1 && strcmp(argv[1], "child") == 0) { |
| 283 | optind = 2; |
| 284 | ret = child_main_loop(argc, argv); |
| 285 | if (ret != 1) |
| 286 | exit(0); |
| 287 | |
| 288 | /* |
| 289 | * If we get here, then the child wants us to continue running |
| 290 | * to potentially spawn yet another child process. This is |
| 291 | * helpful when testing inherited personas and verifying |
| 292 | * persona restrictions. |
| 293 | */ |
| 294 | } |
| 295 | |
| 296 | if (geteuid() != 0) |
| 297 | err("%s must be run as root", argv[0] ? basename(argv[0]) : PERSONA_TEST_NAME); |
| 298 | |
| 299 | struct persona_args pa; |
| 300 | memset(&pa, 0, sizeof(pa)); |
| 301 | |
| 302 | pa.flags = PA_NONE; |
| 303 | pa.kinfo.persona_id = getuid(); |
| 304 | |
| 305 | /* |
| 306 | * Argument parse for default overrides: |
| 307 | */ |
| 308 | while ((ch = getopt(argc, argv, "Vg:I:u:vwh")) != -1) { |
| 309 | switch (ch) { |
| 310 | case 'V': |
| 311 | pa.flags |= PA_SHOULD_VERIFY; |
| 312 | break; |
| 313 | case 'g': |
| 314 | pa.kinfo.persona_gid = atoi(optarg); |
| 315 | if (pa.kinfo.persona_gid <= 500) |
| 316 | err("Invalid GID: %d", pa.kinfo.persona_gid); |
| 317 | pa.flags |= PA_HAS_GID; |
| 318 | pa.flags |= PA_OVERRIDE; |
| 319 | break; |
| 320 | case 'I': |
| 321 | pa.kinfo.persona_id = atoi(optarg); |
| 322 | if (pa.kinfo.persona_id == 0) |
| 323 | err("Invalid Persona ID: %s", optarg); |
| 324 | pa.flags |= PA_HAS_ID; |
| 325 | break; |
| 326 | case 'u': |
| 327 | pa.override_uid = atoi(optarg); |
| 328 | if (pa.override_uid <= 500) |
| 329 | err("Invalid UID: %d", pa.override_uid); |
| 330 | pa.flags |= PA_HAS_UID; |
| 331 | pa.flags |= PA_OVERRIDE; |
| 332 | break; |
| 333 | case 'v': |
| 334 | g.verbose = 1; |
| 335 | break; |
| 336 | case 'w': |
| 337 | g.wait_for_children = 0; |
| 338 | break; |
| 339 | case 'h': |
| 340 | case '?': |
| 341 | usage_main(argv[0], 1); |
| 342 | case ':': |
| 343 | default: |
| 344 | printf("Invalid option: '%c'\n", ch); |
| 345 | usage_main(argv[0], 0); |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | if (pa.flags & PA_SHOULD_VERIFY) |
| 350 | pa.flags = ~PA_OVERRIDE; |
| 351 | |
| 352 | if (optind >= argc) { |
| 353 | printf("No program given!\n"); |
| 354 | usage_main(argv[0], 0); |
| 355 | } |
| 356 | |
| 357 | argc -= optind; |
| 358 | for (int i = 0; i < argc; i++) { |
| 359 | argv[i] = argv[i + optind]; |
| 360 | } |
| 361 | |
| 362 | argv[argc] = NULL; |
| 363 | |
| 364 | ret = spawn_child(argc, argv, &pa); |
| 365 | if (ret < 0) |
| 366 | return ret; |
| 367 | |
| 368 | pid_t child_pid = (pid_t)ret; |
| 369 | int status = 0; |
| 370 | sigset_t sigset; |
| 371 | sigemptyset(&sigset); |
| 372 | sigaddset(&sigset, SIGCHLD); |
| 373 | sigprocmask(SIG_UNBLOCK, &sigset, NULL); |
| 374 | signal(SIGCHLD, main_sighandler); |
| 375 | |
| 376 | if (g.wait_for_children) { |
| 377 | infov("Waiting for child..."); |
| 378 | waitpid(child_pid, &status, 0); |
| 379 | if (WIFEXITED(status)) { |
| 380 | status = WEXITSTATUS(status); |
| 381 | if (status != 0) |
| 382 | errc(ERR_CHILD_FAIL, |
| 383 | "Child exited with status: %d", status); |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | info("Done."); |
| 388 | return 0; |
| 389 | } |