1 /*- 2 * Copyright (c) 2014 Baptiste Daroussin <bapt@FreeBSD.org> 3 * Copyright (c) 2014 Vsevolod Stakhov <vsevolod@FreeBSD.org> 4 * Copyright (c) 2025 Aaron LI <aly@aaronly.me> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #include <sys/procctl.h> 31 #include <sys/resource.h> 32 #include <sys/time.h> 33 #include <sys/wait.h> 34 35 #include <err.h> 36 #include <errno.h> 37 #include <getopt.h> 38 #include <signal.h> 39 #include <stdarg.h> 40 #include <stdbool.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #define EXIT_TIMEOUT 124 47 #define EXIT_INVALID 125 48 #define EXIT_CMD_ERROR 126 49 #define EXIT_CMD_NOENT 127 50 51 static volatile sig_atomic_t sig_chld = 0; 52 static volatile sig_atomic_t sig_alrm = 0; 53 static volatile sig_atomic_t sig_term = 0; /* signal to terminate children */ 54 static volatile sig_atomic_t sig_other = 0; /* signal to propagate */ 55 static int killsig = SIGTERM; /* signal to kill children */ 56 static const char *command = NULL; 57 static bool verbose = false; 58 59 static void __dead2 60 usage(void) 61 { 62 fprintf(stderr, 63 "Usage: %s [-f | --foreground] [-k time | --kill-after time]" 64 " [-p | --preserve-status] [-s signal | --signal signal] " 65 " [-v | --verbose] <duration> <command> [arg ...]\n", 66 getprogname()); 67 exit(EXIT_FAILURE); 68 } 69 70 static void 71 logv(const char *fmt, ...) 72 { 73 va_list ap; 74 75 if (!verbose) 76 return; 77 78 va_start(ap, fmt); 79 vwarnx(fmt, ap); 80 va_end(ap); 81 } 82 83 static double 84 parse_duration(const char *duration) 85 { 86 double ret; 87 char *suffix; 88 89 ret = strtod(duration, &suffix); 90 if (suffix == duration) 91 errx(EXIT_INVALID, "duration is not a number"); 92 93 if (*suffix == '\0') 94 return (ret); 95 96 if (suffix[1] != '\0') 97 errx(EXIT_INVALID, "duration unit suffix too long"); 98 99 switch (*suffix) { 100 case 's': 101 break; 102 case 'm': 103 ret *= 60; 104 break; 105 case 'h': 106 ret *= 60 * 60; 107 break; 108 case 'd': 109 ret *= 60 * 60 * 24; 110 break; 111 default: 112 errx(EXIT_INVALID, "duration unit suffix invalid"); 113 } 114 115 if (ret < 0 || ret >= 100000000UL) 116 errx(EXIT_INVALID, "duration out of range"); 117 118 return (ret); 119 } 120 121 static int 122 parse_signal(const char *str) 123 { 124 int sig, i; 125 const char *errstr; 126 127 sig = strtonum(str, 1, sys_nsig - 1, &errstr); 128 if (errstr == NULL) 129 return (sig); 130 131 if (strncasecmp(str, "SIG", 3) == 0) 132 str += 3; 133 for (i = 1; i < sys_nsig; i++) { 134 if (strcasecmp(str, sys_signame[i]) == 0) 135 return (i); 136 } 137 138 errx(EXIT_INVALID, "invalid signal"); 139 } 140 141 static void 142 sig_handler(int signo) 143 { 144 if (signo == killsig) { 145 sig_term = signo; 146 return; 147 } 148 149 switch (signo) { 150 case SIGCHLD: 151 sig_chld = 1; 152 break; 153 case SIGALRM: 154 sig_alrm = 1; 155 break; 156 case SIGHUP: 157 case SIGINT: 158 case SIGQUIT: 159 case SIGILL: 160 case SIGTRAP: 161 case SIGABRT: 162 case SIGEMT: 163 case SIGFPE: 164 case SIGBUS: 165 case SIGSEGV: 166 case SIGSYS: 167 case SIGPIPE: 168 case SIGTERM: 169 case SIGXCPU: 170 case SIGXFSZ: 171 case SIGVTALRM: 172 case SIGPROF: 173 case SIGUSR1: 174 case SIGUSR2: 175 /* 176 * Signals with default action to terminate the process. 177 * See the sigaction(2) man page. 178 */ 179 sig_term = signo; 180 break; 181 default: 182 sig_other = signo; 183 break; 184 } 185 } 186 187 static void 188 send_sig(pid_t pid, int signo, bool foreground) 189 { 190 struct procctl_reaper_kill rk; 191 192 logv("sending signal %s(%d) to command '%s'", 193 sys_signame[signo], signo, command); 194 if (foreground) { 195 if (kill(pid, signo) == -1) 196 warnx("kill(%d, %s)", (int)pid, sys_signame[signo]); 197 } else { 198 memset(&rk, 0, sizeof(rk)); 199 rk.rk_sig = signo; 200 if (procctl(P_PID, getpid(), PROC_REAP_KILL, &rk) == -1) 201 warnx("procctl(PROC_REAP_KILL)"); 202 else if (rk.rk_fpid > 0) 203 warnx("failed to signal some processes: first pid=%d", 204 (int)rk.rk_fpid); 205 logv("signaled %u processes", rk.rk_killed); 206 } 207 208 /* 209 * If the child process was stopped by a signal, POSIX.1-2024 210 * requires to send a SIGCONT signal. However, the standard also 211 * allows to send a SIGCONT regardless of the stop state, as we 212 * are doing here. 213 */ 214 if (signo != SIGKILL && signo != SIGSTOP && signo != SIGCONT) { 215 logv("sending signal %s(%d) to command '%s'", 216 sys_signame[SIGCONT], SIGCONT, command); 217 if (foreground) { 218 kill(pid, SIGCONT); 219 } else { 220 memset(&rk, 0, sizeof(rk)); 221 rk.rk_sig = SIGCONT; 222 procctl(P_PID, getpid(), PROC_REAP_KILL, &rk); 223 } 224 } 225 } 226 227 static void 228 set_interval(double iv) 229 { 230 struct itimerval tim; 231 232 memset(&tim, 0, sizeof(tim)); 233 if (iv > 0) { 234 tim.it_value.tv_sec = (time_t)iv; 235 iv -= (double)(time_t)iv; 236 tim.it_value.tv_usec = (suseconds_t)(iv * 1000000UL); 237 } 238 239 if (setitimer(ITIMER_REAL, &tim, NULL) == -1) 240 err(EXIT_FAILURE, "setitimer()"); 241 } 242 243 /* 244 * In order to avoid any possible ambiguity that a shell may not set '$?' to 245 * '128+signal_number', POSIX.1-2024 requires that timeout mimic the wait 246 * status of the child process by terminating itself with the same signal, 247 * while disabling core generation. 248 */ 249 static void __dead2 250 kill_self(int signo) 251 { 252 sigset_t mask; 253 struct rlimit rl; 254 255 /* Reset the signal disposition and make sure it's unblocked. */ 256 signal(signo, SIG_DFL); 257 sigfillset(&mask); 258 sigdelset(&mask, signo); 259 sigprocmask(SIG_SETMASK, &mask, NULL); 260 261 /* Disable core generation. */ 262 memset(&rl, 0, sizeof(rl)); 263 setrlimit(RLIMIT_CORE, &rl); 264 265 logv("killing self with signal %s(%d)", sys_signame[signo], signo); 266 kill(getpid(), signo); 267 err(128 + signo, "signal %s(%d) failed to kill self", 268 sys_signame[signo], signo); 269 } 270 271 int 272 main(int argc, char **argv) 273 { 274 int ch, status, sig; 275 int pstat = 0; 276 pid_t pid, cpid; 277 double first_kill; 278 double second_kill = 0; 279 bool foreground = false; 280 bool preserve = false; 281 bool timedout = false; 282 bool do_second_kill = false; 283 bool child_done = false; 284 sigset_t zeromask, allmask, oldmask; 285 struct sigaction sa; 286 struct procctl_reaper_status info; 287 288 const char optstr[] = "+fhk:ps:v"; 289 const struct option longopts[] = { 290 { "foreground", no_argument, NULL, 'f' }, 291 { "help", no_argument, NULL, 'h' }, 292 { "kill-after", required_argument, NULL, 'k' }, 293 { "preserve-status", no_argument, NULL, 'p' }, 294 { "signal", required_argument, NULL, 's' }, 295 { "verbose", no_argument, NULL, 'v' }, 296 { NULL, 0, NULL, 0 }, 297 }; 298 299 while ((ch = getopt_long(argc, argv, optstr, longopts, NULL)) != -1) { 300 switch (ch) { 301 case 'f': 302 foreground = true; 303 break; 304 case 'k': 305 do_second_kill = true; 306 second_kill = parse_duration(optarg); 307 break; 308 case 'p': 309 preserve = true; 310 break; 311 case 's': 312 killsig = parse_signal(optarg); 313 break; 314 case 'v': 315 verbose = true; 316 break; 317 case 0: 318 break; 319 default: 320 usage(); 321 } 322 } 323 324 argc -= optind; 325 argv += optind; 326 if (argc < 2) 327 usage(); 328 329 first_kill = parse_duration(argv[0]); 330 argc--; 331 argv++; 332 command = argv[0]; 333 334 if (!foreground) { 335 /* Acquire a reaper */ 336 if (procctl(P_PID, getpid(), PROC_REAP_ACQUIRE, NULL) == -1) 337 err(EXIT_FAILURE, "procctl(PROC_REAP_ACQUIRE)"); 338 } 339 340 /* Block all signals to avoid racing against the child. */ 341 sigfillset(&allmask); 342 if (sigprocmask(SIG_BLOCK, &allmask, &oldmask) == -1) 343 err(EXIT_FAILURE, "sigprocmask()"); 344 345 pid = fork(); 346 if (pid == -1) { 347 err(EXIT_FAILURE, "fork()"); 348 } else if (pid == 0) { 349 /* 350 * child process 351 * 352 * POSIX.1-2024 requires that the child process inherit the 353 * same signal dispositions as the timeout(1) utility 354 * inherited, except for the signal to be sent upon timeout. 355 */ 356 signal(killsig, SIG_DFL); 357 if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1) 358 err(EXIT_FAILURE, "sigprocmask(oldmask)"); 359 360 execvp(argv[0], argv); 361 warn("exec(%s)", argv[0]); 362 _exit(errno == ENOENT ? EXIT_CMD_NOENT : EXIT_CMD_ERROR); 363 } 364 365 /* parent continues here */ 366 367 /* Catch all signals in order to propagate them. */ 368 memset(&sa, 0, sizeof(sa)); 369 sigfillset(&sa.sa_mask); 370 sa.sa_handler = sig_handler; 371 sa.sa_flags = SA_RESTART; 372 for (sig = 1; sig < sys_nsig; sig++) { 373 if (sig == SIGKILL || sig == SIGSTOP || sig == SIGCONT || 374 sig == SIGTTIN || sig == SIGTTOU) 375 continue; 376 if (sigaction(sig, &sa, NULL) == -1) 377 err(EXIT_FAILURE, "sigaction(%d)", sig); 378 } 379 380 /* Don't stop if background child needs TTY */ 381 signal(SIGTTIN, SIG_IGN); 382 signal(SIGTTOU, SIG_IGN); 383 384 set_interval(first_kill); 385 sigemptyset(&zeromask); 386 387 for (;;) { 388 sigsuspend(&zeromask); 389 390 if (sig_chld) { 391 sig_chld = 0; 392 393 while ((cpid = waitpid(-1, &status, WNOHANG)) != 0) { 394 if (cpid < 0) { 395 if (errno != EINTR) 396 break; 397 } else if (cpid == pid) { 398 pstat = status; 399 child_done = true; 400 logv("child terminated: pid=%d, " 401 "exit=%d, signal=%d", 402 (int)pid, WEXITSTATUS(status), 403 WTERMSIG(status)); 404 } else { 405 /* 406 * Collect grandchildren zombies. 407 * Only effective if we're a reaper. 408 */ 409 logv("collected zombie: pid=%d, " 410 "exit=%d, signal=%d", 411 (int)cpid, WEXITSTATUS(status), 412 WTERMSIG(status)); 413 } 414 } 415 if (child_done) { 416 if (foreground) { 417 break; 418 } else { 419 procctl(P_PID, getpid(), 420 PROC_REAP_STATUS, &info); 421 if (info.rs_children == 0) 422 break; 423 } 424 } 425 } else if (sig_alrm || sig_term) { 426 if (sig_alrm) { 427 sig = killsig; 428 sig_alrm = 0; 429 timedout = true; 430 logv("time limit reached or received SIGALRM"); 431 } else { 432 sig = sig_term; 433 sig_term = 0; 434 logv("received terminating signal %s(%d)", 435 sys_signame[sig], sig); 436 } 437 438 send_sig(pid, sig, foreground); 439 440 if (do_second_kill) { 441 set_interval(second_kill); 442 do_second_kill = false; 443 killsig = SIGKILL; 444 } 445 446 } else if (sig_other) { 447 /* Propagate any other signals. */ 448 sig = sig_other; 449 sig_other = 0; 450 logv("received signal %s(%d)", sys_signame[sig], sig); 451 452 send_sig(pid, sig, foreground); 453 } 454 } 455 456 if (!foreground) 457 procctl(P_PID, getpid(), PROC_REAP_RELEASE, NULL); 458 459 if (timedout && !preserve) { 460 pstat = EXIT_TIMEOUT; 461 } else { 462 if (WIFSIGNALED(pstat)) 463 kill_self(WTERMSIG(pstat)); 464 /* NOTREACHED */ 465 466 if (WIFEXITED(pstat)) 467 pstat = WEXITSTATUS(pstat); 468 } 469 470 return (pstat); 471 } 472