1 /* $OpenBSD: client.c,v 1.126 2018/01/01 11:19:08 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 *); 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(client_proc, 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 { 220 struct cmd *cmd; 221 struct cmd_list *cmdlist; 222 struct msg_command_data *data; 223 int cmdflags, fd, i; 224 const char *ttynam, *cwd; 225 pid_t ppid; 226 enum msgtype msg; 227 char *cause, path[PATH_MAX]; 228 struct termios tio, saved_tio; 229 size_t size; 230 231 /* Ignore SIGCHLD now or daemon() in the server will leave a zombie. */ 232 signal(SIGCHLD, SIG_IGN); 233 234 /* Save the flags. */ 235 client_flags = flags; 236 237 /* Set up the initial command. */ 238 cmdflags = 0; 239 if (shell_command != NULL) { 240 msg = MSG_SHELL; 241 cmdflags = CMD_STARTSERVER; 242 } else if (argc == 0) { 243 msg = MSG_COMMAND; 244 cmdflags = CMD_STARTSERVER; 245 } else { 246 msg = MSG_COMMAND; 247 248 /* 249 * It sucks parsing the command string twice (in client and 250 * later in server) but it is necessary to get the start server 251 * flag. 252 */ 253 cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause); 254 if (cmdlist != NULL) { 255 TAILQ_FOREACH(cmd, &cmdlist->list, qentry) { 256 if (cmd->entry->flags & CMD_STARTSERVER) 257 cmdflags |= CMD_STARTSERVER; 258 } 259 cmd_list_free(cmdlist); 260 } 261 } 262 263 /* Create client process structure (starts logging). */ 264 client_proc = proc_start("client"); 265 proc_set_signals(client_proc, client_signal); 266 267 /* Initialize the client socket and start the server. */ 268 fd = client_connect(base, socket_path, cmdflags & CMD_STARTSERVER); 269 if (fd == -1) { 270 if (errno == ECONNREFUSED) { 271 fprintf(stderr, "no server running on %s\n", 272 socket_path); 273 } else { 274 fprintf(stderr, "error connecting to %s (%s)\n", 275 socket_path, strerror(errno)); 276 } 277 return (1); 278 } 279 client_peer = proc_add_peer(client_proc, fd, client_dispatch, NULL); 280 281 /* Save these before pledge(). */ 282 if ((cwd = getenv("PWD")) == NULL && 283 (cwd = getcwd(path, sizeof path)) == NULL && 284 (cwd = find_home()) == NULL) 285 cwd = "/"; 286 if ((ttynam = ttyname(STDIN_FILENO)) == NULL) 287 ttynam = ""; 288 289 /* 290 * Drop privileges for client. "proc exec" is needed for -c and for 291 * locking (which uses system(3)). 292 * 293 * "tty" is needed to restore termios(4) and also for some reason -CC 294 * does not work properly without it (input is not recognised). 295 * 296 * "sendfd" is dropped later in client_dispatch_wait(). 297 */ 298 if (pledge("stdio unix sendfd proc exec tty", NULL) != 0) 299 fatal("pledge failed"); 300 301 /* Free stuff that is not used in the client. */ 302 if (ptm_fd != -1) 303 close(ptm_fd); 304 options_free(global_options); 305 options_free(global_s_options); 306 options_free(global_w_options); 307 environ_free(global_environ); 308 309 /* Create stdin handler. */ 310 setblocking(STDIN_FILENO, 0); 311 event_set(&client_stdin, STDIN_FILENO, EV_READ|EV_PERSIST, 312 client_stdin_callback, NULL); 313 if (client_flags & CLIENT_CONTROLCONTROL) { 314 if (tcgetattr(STDIN_FILENO, &saved_tio) != 0) { 315 fprintf(stderr, "tcgetattr failed: %s\n", 316 strerror(errno)); 317 return (1); 318 } 319 cfmakeraw(&tio); 320 tio.c_iflag = ICRNL|IXANY; 321 tio.c_oflag = OPOST|ONLCR; 322 tio.c_lflag = NOKERNINFO; 323 tio.c_cflag = CREAD|CS8|HUPCL; 324 tio.c_cc[VMIN] = 1; 325 tio.c_cc[VTIME] = 0; 326 cfsetispeed(&tio, cfgetispeed(&saved_tio)); 327 cfsetospeed(&tio, cfgetospeed(&saved_tio)); 328 tcsetattr(STDIN_FILENO, TCSANOW, &tio); 329 } 330 331 /* Send identify messages. */ 332 client_send_identify(ttynam, cwd); 333 334 /* Send first command. */ 335 if (msg == MSG_COMMAND) { 336 /* How big is the command? */ 337 size = 0; 338 for (i = 0; i < argc; i++) 339 size += strlen(argv[i]) + 1; 340 if (size > MAX_IMSGSIZE - (sizeof *data)) { 341 fprintf(stderr, "command too long\n"); 342 return (1); 343 } 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 client_exec(client_execshell, client_execcmd); 373 } 374 375 /* Print the exit message, if any, and exit. */ 376 if (client_attached) { 377 if (client_exitreason != CLIENT_EXIT_NONE) 378 printf("[%s]\n", client_exit_message()); 379 380 ppid = getppid(); 381 if (client_exittype == MSG_DETACHKILL && ppid > 1) 382 kill(ppid, SIGHUP); 383 } else if (client_flags & CLIENT_CONTROLCONTROL) { 384 if (client_exitreason != CLIENT_EXIT_NONE) 385 printf("%%exit %s\n", client_exit_message()); 386 else 387 printf("%%exit\n"); 388 printf("\033\\"); 389 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 390 } else if (client_exitreason != CLIENT_EXIT_NONE) 391 fprintf(stderr, "%s\n", client_exit_message()); 392 setblocking(STDIN_FILENO, 1); 393 return (client_exitval); 394 } 395 396 /* Send identify messages to server. */ 397 static void 398 client_send_identify(const char *ttynam, const char *cwd) 399 { 400 const char *s; 401 char **ss; 402 size_t sslen; 403 int fd, flags = client_flags; 404 pid_t pid; 405 406 proc_send(client_peer, MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags); 407 408 if ((s = getenv("TERM")) == NULL) 409 s = ""; 410 proc_send(client_peer, MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1); 411 412 proc_send(client_peer, MSG_IDENTIFY_TTYNAME, -1, ttynam, 413 strlen(ttynam) + 1); 414 proc_send(client_peer, MSG_IDENTIFY_CWD, -1, cwd, strlen(cwd) + 1); 415 416 if ((fd = dup(STDIN_FILENO)) == -1) 417 fatal("dup failed"); 418 proc_send(client_peer, MSG_IDENTIFY_STDIN, fd, NULL, 0); 419 420 pid = getpid(); 421 proc_send(client_peer, MSG_IDENTIFY_CLIENTPID, -1, &pid, sizeof pid); 422 423 for (ss = environ; *ss != NULL; ss++) { 424 sslen = strlen(*ss) + 1; 425 if (sslen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) 426 continue; 427 proc_send(client_peer, MSG_IDENTIFY_ENVIRON, -1, *ss, sslen); 428 } 429 430 proc_send(client_peer, MSG_IDENTIFY_DONE, -1, NULL, 0); 431 } 432 433 /* Callback for client stdin read events. */ 434 static void 435 client_stdin_callback(__unused int fd, __unused short events, 436 __unused void *arg) 437 { 438 struct msg_stdin_data data; 439 440 data.size = read(STDIN_FILENO, data.data, sizeof data.data); 441 if (data.size < 0 && (errno == EINTR || errno == EAGAIN)) 442 return; 443 444 proc_send(client_peer, MSG_STDIN, -1, &data, sizeof data); 445 if (data.size <= 0) 446 event_del(&client_stdin); 447 } 448 449 /* Force write to file descriptor. */ 450 static void 451 client_write(int fd, const char *data, size_t size) 452 { 453 ssize_t used; 454 455 log_debug("%s: %.*s", __func__, (int)size, data); 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 proc_clear_signals(client_proc, 1); 489 490 setblocking(STDIN_FILENO, 1); 491 setblocking(STDOUT_FILENO, 1); 492 setblocking(STDERR_FILENO, 1); 493 closefrom(STDERR_FILENO + 1); 494 495 execl(shell, argv0, "-c", shellcmd, (char *) NULL); 496 fatal("execl failed"); 497 } 498 499 /* Callback to handle signals in the client. */ 500 static void 501 client_signal(int sig) 502 { 503 struct sigaction sigact; 504 int status; 505 506 if (sig == SIGCHLD) 507 waitpid(WAIT_ANY, &status, WNOHANG); 508 else if (!client_attached) { 509 if (sig == SIGTERM) 510 proc_exit(client_proc); 511 } else { 512 switch (sig) { 513 case SIGHUP: 514 client_exitreason = CLIENT_EXIT_LOST_TTY; 515 client_exitval = 1; 516 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 517 break; 518 case SIGTERM: 519 client_exitreason = CLIENT_EXIT_TERMINATED; 520 client_exitval = 1; 521 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 522 break; 523 case SIGWINCH: 524 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 525 break; 526 case SIGCONT: 527 memset(&sigact, 0, sizeof sigact); 528 sigemptyset(&sigact.sa_mask); 529 sigact.sa_flags = SA_RESTART; 530 sigact.sa_handler = SIG_IGN; 531 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 532 fatal("sigaction failed"); 533 proc_send(client_peer, MSG_WAKEUP, -1, NULL, 0); 534 break; 535 } 536 } 537 } 538 539 /* Callback for client read events. */ 540 static void 541 client_dispatch(struct imsg *imsg, __unused void *arg) 542 { 543 if (imsg == NULL) { 544 client_exitreason = CLIENT_EXIT_LOST_SERVER; 545 client_exitval = 1; 546 proc_exit(client_proc); 547 return; 548 } 549 550 if (client_attached) 551 client_dispatch_attached(imsg); 552 else 553 client_dispatch_wait(imsg); 554 } 555 556 /* Dispatch imsgs when in wait state (before MSG_READY). */ 557 static void 558 client_dispatch_wait(struct imsg *imsg) 559 { 560 char *data; 561 ssize_t datalen; 562 struct msg_stdout_data stdoutdata; 563 struct msg_stderr_data stderrdata; 564 int retval; 565 static int pledge_applied; 566 567 /* 568 * "sendfd" is no longer required once all of the identify messages 569 * have been sent. We know the server won't send us anything until that 570 * point (because we don't ask it to), so we can drop "sendfd" once we 571 * get the first message from the server. 572 */ 573 if (!pledge_applied) { 574 if (pledge("stdio unix proc exec tty", NULL) != 0) 575 fatal("pledge failed"); 576 pledge_applied = 1; 577 }; 578 579 data = imsg->data; 580 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 581 582 switch (imsg->hdr.type) { 583 case MSG_EXIT: 584 case MSG_SHUTDOWN: 585 if (datalen != sizeof retval && datalen != 0) 586 fatalx("bad MSG_EXIT size"); 587 if (datalen == sizeof retval) { 588 memcpy(&retval, data, sizeof retval); 589 client_exitval = retval; 590 } 591 proc_exit(client_proc); 592 break; 593 case MSG_READY: 594 if (datalen != 0) 595 fatalx("bad MSG_READY size"); 596 597 event_del(&client_stdin); 598 client_attached = 1; 599 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 600 break; 601 case MSG_STDIN: 602 if (datalen != 0) 603 fatalx("bad MSG_STDIN size"); 604 605 event_add(&client_stdin, NULL); 606 break; 607 case MSG_STDOUT: 608 if (datalen != sizeof stdoutdata) 609 fatalx("bad MSG_STDOUT size"); 610 memcpy(&stdoutdata, data, sizeof stdoutdata); 611 612 client_write(STDOUT_FILENO, stdoutdata.data, 613 stdoutdata.size); 614 break; 615 case MSG_STDERR: 616 if (datalen != sizeof stderrdata) 617 fatalx("bad MSG_STDERR size"); 618 memcpy(&stderrdata, data, sizeof stderrdata); 619 620 client_write(STDERR_FILENO, stderrdata.data, 621 stderrdata.size); 622 break; 623 case MSG_VERSION: 624 if (datalen != 0) 625 fatalx("bad MSG_VERSION size"); 626 627 fprintf(stderr, "protocol version mismatch " 628 "(client %d, server %u)\n", PROTOCOL_VERSION, 629 imsg->hdr.peerid & 0xff); 630 client_exitval = 1; 631 proc_exit(client_proc); 632 break; 633 case MSG_SHELL: 634 if (datalen == 0 || data[datalen - 1] != '\0') 635 fatalx("bad MSG_SHELL string"); 636 637 client_exec(data, shell_command); 638 /* NOTREACHED */ 639 case MSG_DETACH: 640 case MSG_DETACHKILL: 641 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 642 break; 643 case MSG_EXITED: 644 proc_exit(client_proc); 645 break; 646 } 647 } 648 649 /* Dispatch imsgs in attached state (after MSG_READY). */ 650 static void 651 client_dispatch_attached(struct imsg *imsg) 652 { 653 struct sigaction sigact; 654 char *data; 655 ssize_t datalen; 656 657 data = imsg->data; 658 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 659 660 switch (imsg->hdr.type) { 661 case MSG_DETACH: 662 case MSG_DETACHKILL: 663 if (datalen == 0 || data[datalen - 1] != '\0') 664 fatalx("bad MSG_DETACH string"); 665 666 client_exitsession = xstrdup(data); 667 client_exittype = imsg->hdr.type; 668 if (imsg->hdr.type == MSG_DETACHKILL) 669 client_exitreason = CLIENT_EXIT_DETACHED_HUP; 670 else 671 client_exitreason = CLIENT_EXIT_DETACHED; 672 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 673 break; 674 case MSG_EXEC: 675 if (datalen == 0 || data[datalen - 1] != '\0' || 676 strlen(data) + 1 == (size_t)datalen) 677 fatalx("bad MSG_EXEC string"); 678 client_execcmd = xstrdup(data); 679 client_execshell = xstrdup(data + strlen(data) + 1); 680 681 client_exittype = imsg->hdr.type; 682 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 683 break; 684 case MSG_EXIT: 685 if (datalen != 0 && datalen != sizeof (int)) 686 fatalx("bad MSG_EXIT size"); 687 688 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 689 client_exitreason = CLIENT_EXIT_EXITED; 690 break; 691 case MSG_EXITED: 692 if (datalen != 0) 693 fatalx("bad MSG_EXITED size"); 694 695 proc_exit(client_proc); 696 break; 697 case MSG_SHUTDOWN: 698 if (datalen != 0) 699 fatalx("bad MSG_SHUTDOWN size"); 700 701 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 702 client_exitreason = CLIENT_EXIT_SERVER_EXITED; 703 client_exitval = 1; 704 break; 705 case MSG_SUSPEND: 706 if (datalen != 0) 707 fatalx("bad MSG_SUSPEND size"); 708 709 memset(&sigact, 0, sizeof sigact); 710 sigemptyset(&sigact.sa_mask); 711 sigact.sa_flags = SA_RESTART; 712 sigact.sa_handler = SIG_DFL; 713 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 714 fatal("sigaction failed"); 715 kill(getpid(), SIGTSTP); 716 break; 717 case MSG_LOCK: 718 if (datalen == 0 || data[datalen - 1] != '\0') 719 fatalx("bad MSG_LOCK string"); 720 721 system(data); 722 proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0); 723 break; 724 } 725 } 726