1 /* $OpenBSD: client.c,v 1.119 2017/01/23 10:09:43 nicm Exp $ */ 2 3 /* 4 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER 15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/file.h> 21 #include <sys/socket.h> 22 #include <sys/stat.h> 23 #include <sys/un.h> 24 #include <sys/wait.h> 25 26 #include <errno.h> 27 #include <event.h> 28 #include <fcntl.h> 29 #include <imsg.h> 30 #include <signal.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <unistd.h> 34 35 #include "tmux.h" 36 37 static struct tmuxproc *client_proc; 38 static struct tmuxpeer *client_peer; 39 static int client_flags; 40 static struct event client_stdin; 41 static enum { 42 CLIENT_EXIT_NONE, 43 CLIENT_EXIT_DETACHED, 44 CLIENT_EXIT_DETACHED_HUP, 45 CLIENT_EXIT_LOST_TTY, 46 CLIENT_EXIT_TERMINATED, 47 CLIENT_EXIT_LOST_SERVER, 48 CLIENT_EXIT_EXITED, 49 CLIENT_EXIT_SERVER_EXITED, 50 } client_exitreason = CLIENT_EXIT_NONE; 51 static int client_exitval; 52 static enum msgtype client_exittype; 53 static const char *client_exitsession; 54 static const char *client_execshell; 55 static const char *client_execcmd; 56 static int client_attached; 57 58 static __dead void client_exec(const char *,const char *); 59 static int client_get_lock(char *); 60 static int client_connect(struct event_base *, const char *, int); 61 static void client_send_identify(const char *, const char *); 62 static void client_stdin_callback(int, short, void *); 63 static void client_write(int, const char *, size_t); 64 static void client_signal(int); 65 static void client_dispatch(struct imsg *, void *); 66 static void client_dispatch_attached(struct imsg *); 67 static void client_dispatch_wait(struct imsg *, const char *); 68 static const char *client_exit_message(void); 69 70 /* 71 * Get server create lock. If already held then server start is happening in 72 * another client, so block until the lock is released and return -2 to 73 * retry. Return -1 on failure to continue and start the server anyway. 74 */ 75 static int 76 client_get_lock(char *lockfile) 77 { 78 int lockfd; 79 80 log_debug("lock file is %s", lockfile); 81 82 if ((lockfd = open(lockfile, O_WRONLY|O_CREAT, 0600)) == -1) { 83 log_debug("open failed: %s", strerror(errno)); 84 return (-1); 85 } 86 87 if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) { 88 log_debug("flock failed: %s", strerror(errno)); 89 if (errno != EAGAIN) 90 return (lockfd); 91 while (flock(lockfd, LOCK_EX) == -1 && errno == EINTR) 92 /* nothing */; 93 close(lockfd); 94 return (-2); 95 } 96 log_debug("flock succeeded"); 97 98 return (lockfd); 99 } 100 101 /* Connect client to server. */ 102 static int 103 client_connect(struct event_base *base, const char *path, int start_server) 104 { 105 struct sockaddr_un sa; 106 size_t size; 107 int fd, lockfd = -1, locked = 0; 108 char *lockfile = NULL; 109 110 memset(&sa, 0, sizeof sa); 111 sa.sun_family = AF_UNIX; 112 size = strlcpy(sa.sun_path, path, sizeof sa.sun_path); 113 if (size >= sizeof sa.sun_path) { 114 errno = ENAMETOOLONG; 115 return (-1); 116 } 117 log_debug("socket is %s", path); 118 119 retry: 120 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 121 return (-1); 122 123 log_debug("trying connect"); 124 if (connect(fd, (struct sockaddr *)&sa, sizeof sa) == -1) { 125 log_debug("connect failed: %s", strerror(errno)); 126 if (errno != ECONNREFUSED && errno != ENOENT) 127 goto failed; 128 if (!start_server) 129 goto failed; 130 close(fd); 131 132 if (!locked) { 133 xasprintf(&lockfile, "%s.lock", path); 134 if ((lockfd = client_get_lock(lockfile)) < 0) { 135 log_debug("didn't get lock (%d)", lockfd); 136 137 free(lockfile); 138 lockfile = NULL; 139 140 if (lockfd == -2) 141 goto retry; 142 } 143 log_debug("got lock (%d)", lockfd); 144 145 /* 146 * Always retry at least once, even if we got the lock, 147 * because another client could have taken the lock, 148 * started the server and released the lock between our 149 * connect() and flock(). 150 */ 151 locked = 1; 152 goto retry; 153 } 154 155 if (lockfd >= 0 && unlink(path) != 0 && errno != ENOENT) { 156 free(lockfile); 157 close(lockfd); 158 return (-1); 159 } 160 fd = server_start(base, lockfd, lockfile); 161 } 162 163 if (locked && lockfd >= 0) { 164 free(lockfile); 165 close(lockfd); 166 } 167 setblocking(fd, 0); 168 return (fd); 169 170 failed: 171 if (locked) { 172 free(lockfile); 173 close(lockfd); 174 } 175 close(fd); 176 return (-1); 177 } 178 179 /* Get exit string from reason number. */ 180 const char * 181 client_exit_message(void) 182 { 183 static char msg[256]; 184 185 switch (client_exitreason) { 186 case CLIENT_EXIT_NONE: 187 break; 188 case CLIENT_EXIT_DETACHED: 189 if (client_exitsession != NULL) { 190 xsnprintf(msg, sizeof msg, "detached " 191 "(from session %s)", client_exitsession); 192 return (msg); 193 } 194 return ("detached"); 195 case CLIENT_EXIT_DETACHED_HUP: 196 if (client_exitsession != NULL) { 197 xsnprintf(msg, sizeof msg, "detached and SIGHUP " 198 "(from session %s)", client_exitsession); 199 return (msg); 200 } 201 return ("detached and SIGHUP"); 202 case CLIENT_EXIT_LOST_TTY: 203 return ("lost tty"); 204 case CLIENT_EXIT_TERMINATED: 205 return ("terminated"); 206 case CLIENT_EXIT_LOST_SERVER: 207 return ("lost server"); 208 case CLIENT_EXIT_EXITED: 209 return ("exited"); 210 case CLIENT_EXIT_SERVER_EXITED: 211 return ("server exited"); 212 } 213 return ("unknown reason"); 214 } 215 216 /* Client main loop. */ 217 int 218 client_main(struct event_base *base, int argc, char **argv, int flags, 219 const char *shellcmd) 220 { 221 struct cmd *cmd; 222 struct cmd_list *cmdlist; 223 struct msg_command_data *data; 224 int cmdflags, fd, i; 225 const char *ttynam, *cwd; 226 pid_t ppid; 227 enum msgtype msg; 228 char *cause, path[PATH_MAX]; 229 struct termios tio, saved_tio; 230 size_t size; 231 232 /* Ignore SIGCHLD now or daemon() in the server will leave a zombie. */ 233 signal(SIGCHLD, SIG_IGN); 234 235 /* Save the flags. */ 236 client_flags = flags; 237 238 /* Set up the initial command. */ 239 cmdflags = 0; 240 if (shellcmd != NULL) { 241 msg = MSG_SHELL; 242 cmdflags = CMD_STARTSERVER; 243 } else if (argc == 0) { 244 msg = MSG_COMMAND; 245 cmdflags = CMD_STARTSERVER; 246 } else { 247 msg = MSG_COMMAND; 248 249 /* 250 * It sucks parsing the command string twice (in client and 251 * later in server) but it is necessary to get the start server 252 * flag. 253 */ 254 cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause); 255 if (cmdlist == NULL) { 256 fprintf(stderr, "%s\n", cause); 257 return (1); 258 } 259 cmdflags &= ~CMD_STARTSERVER; 260 TAILQ_FOREACH(cmd, &cmdlist->list, qentry) { 261 if (cmd->entry->flags & CMD_STARTSERVER) 262 cmdflags |= CMD_STARTSERVER; 263 } 264 cmd_list_free(cmdlist); 265 } 266 267 /* Create client process structure (starts logging). */ 268 client_proc = proc_start("client", base, 0, client_signal); 269 270 /* Initialize the client socket and start the server. */ 271 fd = client_connect(base, socket_path, cmdflags & CMD_STARTSERVER); 272 if (fd == -1) { 273 if (errno == ECONNREFUSED) { 274 fprintf(stderr, "no server running on %s\n", 275 socket_path); 276 } else { 277 fprintf(stderr, "error connecting to %s (%s)\n", 278 socket_path, strerror(errno)); 279 } 280 return (1); 281 } 282 client_peer = proc_add_peer(client_proc, fd, client_dispatch, 283 (void *)shellcmd); 284 285 /* Save these before pledge(). */ 286 if ((cwd = getcwd(path, sizeof path)) == NULL) { 287 if ((cwd = find_home()) == NULL) 288 cwd = "/"; 289 } 290 if ((ttynam = ttyname(STDIN_FILENO)) == NULL) 291 ttynam = ""; 292 293 /* 294 * Drop privileges for client. "proc exec" is needed for -c and for 295 * locking (which uses system(3)). 296 * 297 * "tty" is needed to restore termios(4) and also for some reason -CC 298 * does not work properly without it (input is not recognised). 299 * 300 * "sendfd" is dropped later in client_dispatch_wait(). 301 */ 302 if (pledge("stdio unix sendfd proc exec tty", NULL) != 0) 303 fatal("pledge failed"); 304 305 /* Free stuff that is not used in the client. */ 306 if (ptm_fd != -1) 307 close(ptm_fd); 308 options_free(global_options); 309 options_free(global_s_options); 310 options_free(global_w_options); 311 environ_free(global_environ); 312 313 /* Create stdin handler. */ 314 setblocking(STDIN_FILENO, 0); 315 event_set(&client_stdin, STDIN_FILENO, EV_READ|EV_PERSIST, 316 client_stdin_callback, NULL); 317 if (client_flags & CLIENT_CONTROLCONTROL) { 318 if (tcgetattr(STDIN_FILENO, &saved_tio) != 0) { 319 fprintf(stderr, "tcgetattr failed: %s\n", 320 strerror(errno)); 321 return (1); 322 } 323 cfmakeraw(&tio); 324 tio.c_iflag = ICRNL|IXANY; 325 tio.c_oflag = OPOST|ONLCR; 326 tio.c_lflag = NOKERNINFO; 327 tio.c_cflag = CREAD|CS8|HUPCL; 328 tio.c_cc[VMIN] = 1; 329 tio.c_cc[VTIME] = 0; 330 cfsetispeed(&tio, cfgetispeed(&saved_tio)); 331 cfsetospeed(&tio, cfgetospeed(&saved_tio)); 332 tcsetattr(STDIN_FILENO, TCSANOW, &tio); 333 } 334 335 /* Send identify messages. */ 336 client_send_identify(ttynam, cwd); 337 338 /* Send first command. */ 339 if (msg == MSG_COMMAND) { 340 /* How big is the command? */ 341 size = 0; 342 for (i = 0; i < argc; i++) 343 size += strlen(argv[i]) + 1; 344 data = xmalloc((sizeof *data) + size); 345 346 /* Prepare command for server. */ 347 data->argc = argc; 348 if (cmd_pack_argv(argc, argv, (char *)(data + 1), size) != 0) { 349 fprintf(stderr, "command too long\n"); 350 free(data); 351 return (1); 352 } 353 size += sizeof *data; 354 355 /* Send the command. */ 356 if (proc_send(client_peer, msg, -1, data, size) != 0) { 357 fprintf(stderr, "failed to send command\n"); 358 free(data); 359 return (1); 360 } 361 free(data); 362 } else if (msg == MSG_SHELL) 363 proc_send(client_peer, msg, -1, NULL, 0); 364 365 /* Start main loop. */ 366 proc_loop(client_proc, NULL); 367 368 /* Run command if user requested exec, instead of exiting. */ 369 if (client_exittype == MSG_EXEC) { 370 if (client_flags & CLIENT_CONTROLCONTROL) 371 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 372 clear_signals(0); 373 client_exec(client_execshell, client_execcmd); 374 } 375 376 /* Print the exit message, if any, and exit. */ 377 if (client_attached) { 378 if (client_exitreason != CLIENT_EXIT_NONE) 379 printf("[%s]\n", client_exit_message()); 380 381 ppid = getppid(); 382 if (client_exittype == MSG_DETACHKILL && ppid > 1) 383 kill(ppid, SIGHUP); 384 } else if (client_flags & CLIENT_CONTROLCONTROL) { 385 if (client_exitreason != CLIENT_EXIT_NONE) 386 printf("%%exit %s\n", client_exit_message()); 387 else 388 printf("%%exit\n"); 389 printf("\033\\"); 390 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 391 } else if (client_exitreason != CLIENT_EXIT_NONE) 392 fprintf(stderr, "%s\n", client_exit_message()); 393 setblocking(STDIN_FILENO, 1); 394 return (client_exitval); 395 } 396 397 /* Send identify messages to server. */ 398 static void 399 client_send_identify(const char *ttynam, const char *cwd) 400 { 401 const char *s; 402 char **ss; 403 size_t sslen; 404 int fd, flags = client_flags; 405 pid_t pid; 406 407 proc_send(client_peer, MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags); 408 409 if ((s = getenv("TERM")) == NULL) 410 s = ""; 411 proc_send(client_peer, MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1); 412 413 proc_send(client_peer, MSG_IDENTIFY_TTYNAME, -1, ttynam, 414 strlen(ttynam) + 1); 415 proc_send(client_peer, MSG_IDENTIFY_CWD, -1, cwd, strlen(cwd) + 1); 416 417 if ((fd = dup(STDIN_FILENO)) == -1) 418 fatal("dup failed"); 419 proc_send(client_peer, MSG_IDENTIFY_STDIN, fd, NULL, 0); 420 421 pid = getpid(); 422 proc_send(client_peer, MSG_IDENTIFY_CLIENTPID, -1, &pid, sizeof pid); 423 424 for (ss = environ; *ss != NULL; ss++) { 425 sslen = strlen(*ss) + 1; 426 if (sslen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) 427 continue; 428 proc_send(client_peer, MSG_IDENTIFY_ENVIRON, -1, *ss, sslen); 429 } 430 431 proc_send(client_peer, MSG_IDENTIFY_DONE, -1, NULL, 0); 432 } 433 434 /* Callback for client stdin read events. */ 435 static void 436 client_stdin_callback(__unused int fd, __unused short events, 437 __unused void *arg) 438 { 439 struct msg_stdin_data data; 440 441 data.size = read(STDIN_FILENO, data.data, sizeof data.data); 442 if (data.size < 0 && (errno == EINTR || errno == EAGAIN)) 443 return; 444 445 proc_send(client_peer, MSG_STDIN, -1, &data, sizeof data); 446 if (data.size <= 0) 447 event_del(&client_stdin); 448 } 449 450 /* Force write to file descriptor. */ 451 static void 452 client_write(int fd, const char *data, size_t size) 453 { 454 ssize_t used; 455 456 while (size != 0) { 457 used = write(fd, data, size); 458 if (used == -1) { 459 if (errno == EINTR || errno == EAGAIN) 460 continue; 461 break; 462 } 463 data += used; 464 size -= used; 465 } 466 } 467 468 /* Run command in shell; used for -c. */ 469 static __dead void 470 client_exec(const char *shell, const char *shellcmd) 471 { 472 const char *name, *ptr; 473 char *argv0; 474 475 log_debug("shell %s, command %s", shell, shellcmd); 476 477 ptr = strrchr(shell, '/'); 478 if (ptr != NULL && *(ptr + 1) != '\0') 479 name = ptr + 1; 480 else 481 name = shell; 482 if (client_flags & CLIENT_LOGIN) 483 xasprintf(&argv0, "-%s", name); 484 else 485 xasprintf(&argv0, "%s", name); 486 setenv("SHELL", shell, 1); 487 488 setblocking(STDIN_FILENO, 1); 489 setblocking(STDOUT_FILENO, 1); 490 setblocking(STDERR_FILENO, 1); 491 closefrom(STDERR_FILENO + 1); 492 493 execl(shell, argv0, "-c", shellcmd, (char *) NULL); 494 fatal("execl failed"); 495 } 496 497 /* Callback to handle signals in the client. */ 498 static void 499 client_signal(int sig) 500 { 501 struct sigaction sigact; 502 int status; 503 504 if (sig == SIGCHLD) 505 waitpid(WAIT_ANY, &status, WNOHANG); 506 else if (!client_attached) { 507 if (sig == SIGTERM) 508 proc_exit(client_proc); 509 } else { 510 switch (sig) { 511 case SIGHUP: 512 client_exitreason = CLIENT_EXIT_LOST_TTY; 513 client_exitval = 1; 514 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 515 break; 516 case SIGTERM: 517 client_exitreason = CLIENT_EXIT_TERMINATED; 518 client_exitval = 1; 519 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 520 break; 521 case SIGWINCH: 522 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 523 break; 524 case SIGCONT: 525 memset(&sigact, 0, sizeof sigact); 526 sigemptyset(&sigact.sa_mask); 527 sigact.sa_flags = SA_RESTART; 528 sigact.sa_handler = SIG_IGN; 529 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 530 fatal("sigaction failed"); 531 proc_send(client_peer, MSG_WAKEUP, -1, NULL, 0); 532 break; 533 } 534 } 535 } 536 537 /* Callback for client read events. */ 538 static void 539 client_dispatch(struct imsg *imsg, void *arg) 540 { 541 if (imsg == NULL) { 542 client_exitreason = CLIENT_EXIT_LOST_SERVER; 543 client_exitval = 1; 544 proc_exit(client_proc); 545 return; 546 } 547 548 if (client_attached) 549 client_dispatch_attached(imsg); 550 else 551 client_dispatch_wait(imsg, arg); 552 } 553 554 /* Dispatch imsgs when in wait state (before MSG_READY). */ 555 static void 556 client_dispatch_wait(struct imsg *imsg, const char *shellcmd) 557 { 558 char *data; 559 ssize_t datalen; 560 struct msg_stdout_data stdoutdata; 561 struct msg_stderr_data stderrdata; 562 int retval; 563 static int pledge_applied; 564 565 /* 566 * "sendfd" is no longer required once all of the identify messages 567 * have been sent. We know the server won't send us anything until that 568 * point (because we don't ask it to), so we can drop "sendfd" once we 569 * get the first message from the server. 570 */ 571 if (!pledge_applied) { 572 if (pledge("stdio unix proc exec tty", NULL) != 0) 573 fatal("pledge failed"); 574 pledge_applied = 1; 575 }; 576 577 data = imsg->data; 578 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 579 580 switch (imsg->hdr.type) { 581 case MSG_EXIT: 582 case MSG_SHUTDOWN: 583 if (datalen != sizeof retval && datalen != 0) 584 fatalx("bad MSG_EXIT size"); 585 if (datalen == sizeof retval) { 586 memcpy(&retval, data, sizeof retval); 587 client_exitval = retval; 588 } 589 proc_exit(client_proc); 590 break; 591 case MSG_READY: 592 if (datalen != 0) 593 fatalx("bad MSG_READY size"); 594 595 event_del(&client_stdin); 596 client_attached = 1; 597 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 598 break; 599 case MSG_STDIN: 600 if (datalen != 0) 601 fatalx("bad MSG_STDIN size"); 602 603 event_add(&client_stdin, NULL); 604 break; 605 case MSG_STDOUT: 606 if (datalen != sizeof stdoutdata) 607 fatalx("bad MSG_STDOUT size"); 608 memcpy(&stdoutdata, data, sizeof stdoutdata); 609 610 client_write(STDOUT_FILENO, stdoutdata.data, 611 stdoutdata.size); 612 break; 613 case MSG_STDERR: 614 if (datalen != sizeof stderrdata) 615 fatalx("bad MSG_STDERR size"); 616 memcpy(&stderrdata, data, sizeof stderrdata); 617 618 client_write(STDERR_FILENO, stderrdata.data, 619 stderrdata.size); 620 break; 621 case MSG_VERSION: 622 if (datalen != 0) 623 fatalx("bad MSG_VERSION size"); 624 625 fprintf(stderr, "protocol version mismatch " 626 "(client %d, server %u)\n", PROTOCOL_VERSION, 627 imsg->hdr.peerid & 0xff); 628 client_exitval = 1; 629 proc_exit(client_proc); 630 break; 631 case MSG_SHELL: 632 if (datalen == 0 || data[datalen - 1] != '\0') 633 fatalx("bad MSG_SHELL string"); 634 635 clear_signals(0); 636 client_exec(data, shellcmd); 637 /* NOTREACHED */ 638 case MSG_DETACH: 639 case MSG_DETACHKILL: 640 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 641 break; 642 case MSG_EXITED: 643 proc_exit(client_proc); 644 break; 645 } 646 } 647 648 /* Dispatch imsgs in attached state (after MSG_READY). */ 649 static void 650 client_dispatch_attached(struct imsg *imsg) 651 { 652 struct sigaction sigact; 653 char *data; 654 ssize_t datalen; 655 656 data = imsg->data; 657 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 658 659 switch (imsg->hdr.type) { 660 case MSG_DETACH: 661 case MSG_DETACHKILL: 662 if (datalen == 0 || data[datalen - 1] != '\0') 663 fatalx("bad MSG_DETACH string"); 664 665 client_exitsession = xstrdup(data); 666 client_exittype = imsg->hdr.type; 667 if (imsg->hdr.type == MSG_DETACHKILL) 668 client_exitreason = CLIENT_EXIT_DETACHED_HUP; 669 else 670 client_exitreason = CLIENT_EXIT_DETACHED; 671 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 672 break; 673 case MSG_EXEC: 674 if (datalen == 0 || data[datalen - 1] != '\0' || 675 strlen(data) + 1 == (size_t)datalen) 676 fatalx("bad MSG_EXEC string"); 677 client_execcmd = xstrdup(data); 678 client_execshell = xstrdup(data + strlen(data) + 1); 679 680 client_exittype = imsg->hdr.type; 681 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 682 break; 683 case MSG_EXIT: 684 if (datalen != 0 && datalen != sizeof (int)) 685 fatalx("bad MSG_EXIT size"); 686 687 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 688 client_exitreason = CLIENT_EXIT_EXITED; 689 break; 690 case MSG_EXITED: 691 if (datalen != 0) 692 fatalx("bad MSG_EXITED size"); 693 694 proc_exit(client_proc); 695 break; 696 case MSG_SHUTDOWN: 697 if (datalen != 0) 698 fatalx("bad MSG_SHUTDOWN size"); 699 700 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 701 client_exitreason = CLIENT_EXIT_SERVER_EXITED; 702 client_exitval = 1; 703 break; 704 case MSG_SUSPEND: 705 if (datalen != 0) 706 fatalx("bad MSG_SUSPEND size"); 707 708 memset(&sigact, 0, sizeof sigact); 709 sigemptyset(&sigact.sa_mask); 710 sigact.sa_flags = SA_RESTART; 711 sigact.sa_handler = SIG_DFL; 712 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 713 fatal("sigaction failed"); 714 kill(getpid(), SIGTSTP); 715 break; 716 case MSG_LOCK: 717 if (datalen == 0 || data[datalen - 1] != '\0') 718 fatalx("bad MSG_LOCK string"); 719 720 system(data); 721 proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0); 722 break; 723 } 724 } 725