1 /* $OpenBSD: client.c,v 1.115 2017/01/13 10:12:12 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 options_free(global_options); 307 options_free(global_s_options); 308 options_free(global_w_options); 309 environ_free(global_environ); 310 311 /* Create stdin handler. */ 312 setblocking(STDIN_FILENO, 0); 313 event_set(&client_stdin, STDIN_FILENO, EV_READ|EV_PERSIST, 314 client_stdin_callback, NULL); 315 if (client_flags & CLIENT_CONTROLCONTROL) { 316 if (tcgetattr(STDIN_FILENO, &saved_tio) != 0) 317 fatal("tcgetattr failed"); 318 cfmakeraw(&tio); 319 tio.c_iflag = ICRNL|IXANY; 320 tio.c_oflag = OPOST|ONLCR; 321 tio.c_lflag = NOKERNINFO; 322 tio.c_cflag = CREAD|CS8|HUPCL; 323 tio.c_cc[VMIN] = 1; 324 tio.c_cc[VTIME] = 0; 325 cfsetispeed(&tio, cfgetispeed(&saved_tio)); 326 cfsetospeed(&tio, cfgetospeed(&saved_tio)); 327 tcsetattr(STDIN_FILENO, TCSANOW, &tio); 328 } 329 330 /* Send identify messages. */ 331 client_send_identify(ttynam, cwd); 332 333 /* Send first command. */ 334 if (msg == MSG_COMMAND) { 335 /* How big is the command? */ 336 size = 0; 337 for (i = 0; i < argc; i++) 338 size += strlen(argv[i]) + 1; 339 data = xmalloc((sizeof *data) + size); 340 341 /* Prepare command for server. */ 342 data->argc = argc; 343 if (cmd_pack_argv(argc, argv, (char *)(data + 1), size) != 0) { 344 fprintf(stderr, "command too long\n"); 345 free(data); 346 return (1); 347 } 348 size += sizeof *data; 349 350 /* Send the command. */ 351 if (proc_send(client_peer, msg, -1, data, size) != 0) { 352 fprintf(stderr, "failed to send command\n"); 353 free(data); 354 return (1); 355 } 356 free(data); 357 } else if (msg == MSG_SHELL) 358 proc_send(client_peer, msg, -1, NULL, 0); 359 360 /* Start main loop. */ 361 proc_loop(client_proc, NULL); 362 363 /* Run command if user requested exec, instead of exiting. */ 364 if (client_exittype == MSG_EXEC) { 365 if (client_flags & CLIENT_CONTROLCONTROL) 366 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 367 clear_signals(0); 368 client_exec(client_execshell, client_execcmd); 369 } 370 371 /* Print the exit message, if any, and exit. */ 372 if (client_attached) { 373 if (client_exitreason != CLIENT_EXIT_NONE) 374 printf("[%s]\n", client_exit_message()); 375 376 ppid = getppid(); 377 if (client_exittype == MSG_DETACHKILL && ppid > 1) 378 kill(ppid, SIGHUP); 379 } else if (client_flags & CLIENT_CONTROLCONTROL) { 380 if (client_exitreason != CLIENT_EXIT_NONE) 381 printf("%%exit %s\n", client_exit_message()); 382 else 383 printf("%%exit\n"); 384 printf("\033\\"); 385 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 386 } else if (client_exitreason != CLIENT_EXIT_NONE) 387 fprintf(stderr, "%s\n", client_exit_message()); 388 setblocking(STDIN_FILENO, 1); 389 return (client_exitval); 390 } 391 392 /* Send identify messages to server. */ 393 static void 394 client_send_identify(const char *ttynam, const char *cwd) 395 { 396 const char *s; 397 char **ss; 398 size_t sslen; 399 int fd, flags = client_flags; 400 pid_t pid; 401 402 proc_send(client_peer, MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags); 403 404 if ((s = getenv("TERM")) == NULL) 405 s = ""; 406 proc_send(client_peer, MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1); 407 408 proc_send(client_peer, MSG_IDENTIFY_TTYNAME, -1, ttynam, 409 strlen(ttynam) + 1); 410 proc_send(client_peer, MSG_IDENTIFY_CWD, -1, cwd, strlen(cwd) + 1); 411 412 if ((fd = dup(STDIN_FILENO)) == -1) 413 fatal("dup failed"); 414 proc_send(client_peer, MSG_IDENTIFY_STDIN, fd, NULL, 0); 415 416 pid = getpid(); 417 proc_send(client_peer, MSG_IDENTIFY_CLIENTPID, -1, &pid, sizeof pid); 418 419 for (ss = environ; *ss != NULL; ss++) { 420 sslen = strlen(*ss) + 1; 421 if (sslen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) 422 continue; 423 proc_send(client_peer, MSG_IDENTIFY_ENVIRON, -1, *ss, sslen); 424 } 425 426 proc_send(client_peer, MSG_IDENTIFY_DONE, -1, NULL, 0); 427 } 428 429 /* Callback for client stdin read events. */ 430 static void 431 client_stdin_callback(__unused int fd, __unused short events, 432 __unused void *arg) 433 { 434 struct msg_stdin_data data; 435 436 data.size = read(STDIN_FILENO, data.data, sizeof data.data); 437 if (data.size < 0 && (errno == EINTR || errno == EAGAIN)) 438 return; 439 440 proc_send(client_peer, MSG_STDIN, -1, &data, sizeof data); 441 if (data.size <= 0) 442 event_del(&client_stdin); 443 } 444 445 /* Force write to file descriptor. */ 446 static void 447 client_write(int fd, const char *data, size_t size) 448 { 449 ssize_t used; 450 451 while (size != 0) { 452 used = write(fd, data, size); 453 if (used == -1) { 454 if (errno == EINTR || errno == EAGAIN) 455 continue; 456 break; 457 } 458 data += used; 459 size -= used; 460 } 461 } 462 463 /* Run command in shell; used for -c. */ 464 static __dead void 465 client_exec(const char *shell, const char *shellcmd) 466 { 467 const char *name, *ptr; 468 char *argv0; 469 470 log_debug("shell %s, command %s", shell, shellcmd); 471 472 ptr = strrchr(shell, '/'); 473 if (ptr != NULL && *(ptr + 1) != '\0') 474 name = ptr + 1; 475 else 476 name = shell; 477 if (client_flags & CLIENT_LOGIN) 478 xasprintf(&argv0, "-%s", name); 479 else 480 xasprintf(&argv0, "%s", name); 481 setenv("SHELL", shell, 1); 482 483 setblocking(STDIN_FILENO, 1); 484 setblocking(STDOUT_FILENO, 1); 485 setblocking(STDERR_FILENO, 1); 486 closefrom(STDERR_FILENO + 1); 487 488 execl(shell, argv0, "-c", shellcmd, (char *) NULL); 489 fatal("execl failed"); 490 } 491 492 /* Callback to handle signals in the client. */ 493 static void 494 client_signal(int sig) 495 { 496 struct sigaction sigact; 497 int status; 498 499 if (sig == SIGCHLD) 500 waitpid(WAIT_ANY, &status, WNOHANG); 501 else if (!client_attached) { 502 if (sig == SIGTERM) 503 proc_exit(client_proc); 504 } else { 505 switch (sig) { 506 case SIGHUP: 507 client_exitreason = CLIENT_EXIT_LOST_TTY; 508 client_exitval = 1; 509 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 510 break; 511 case SIGTERM: 512 client_exitreason = CLIENT_EXIT_TERMINATED; 513 client_exitval = 1; 514 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 515 break; 516 case SIGWINCH: 517 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 518 break; 519 case SIGCONT: 520 memset(&sigact, 0, sizeof sigact); 521 sigemptyset(&sigact.sa_mask); 522 sigact.sa_flags = SA_RESTART; 523 sigact.sa_handler = SIG_IGN; 524 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 525 fatal("sigaction failed"); 526 proc_send(client_peer, MSG_WAKEUP, -1, NULL, 0); 527 break; 528 } 529 } 530 } 531 532 /* Callback for client read events. */ 533 static void 534 client_dispatch(struct imsg *imsg, void *arg) 535 { 536 if (imsg == NULL) { 537 client_exitreason = CLIENT_EXIT_LOST_SERVER; 538 client_exitval = 1; 539 proc_exit(client_proc); 540 return; 541 } 542 543 if (client_attached) 544 client_dispatch_attached(imsg); 545 else 546 client_dispatch_wait(imsg, arg); 547 } 548 549 /* Dispatch imsgs when in wait state (before MSG_READY). */ 550 static void 551 client_dispatch_wait(struct imsg *imsg, const char *shellcmd) 552 { 553 char *data; 554 ssize_t datalen; 555 struct msg_stdout_data stdoutdata; 556 struct msg_stderr_data stderrdata; 557 int retval; 558 static int pledge_applied; 559 560 /* 561 * "sendfd" is no longer required once all of the identify messages 562 * have been sent. We know the server won't send us anything until that 563 * point (because we don't ask it to), so we can drop "sendfd" once we 564 * get the first message from the server. 565 */ 566 if (!pledge_applied) { 567 if (pledge("stdio unix proc exec tty", NULL) != 0) 568 fatal("pledge failed"); 569 pledge_applied = 1; 570 }; 571 572 data = imsg->data; 573 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 574 575 switch (imsg->hdr.type) { 576 case MSG_EXIT: 577 case MSG_SHUTDOWN: 578 if (datalen != sizeof retval && datalen != 0) 579 fatalx("bad MSG_EXIT size"); 580 if (datalen == sizeof retval) { 581 memcpy(&retval, data, sizeof retval); 582 client_exitval = retval; 583 } 584 proc_exit(client_proc); 585 break; 586 case MSG_READY: 587 if (datalen != 0) 588 fatalx("bad MSG_READY size"); 589 590 event_del(&client_stdin); 591 client_attached = 1; 592 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 593 break; 594 case MSG_STDIN: 595 if (datalen != 0) 596 fatalx("bad MSG_STDIN size"); 597 598 event_add(&client_stdin, NULL); 599 break; 600 case MSG_STDOUT: 601 if (datalen != sizeof stdoutdata) 602 fatalx("bad MSG_STDOUT size"); 603 memcpy(&stdoutdata, data, sizeof stdoutdata); 604 605 client_write(STDOUT_FILENO, stdoutdata.data, 606 stdoutdata.size); 607 break; 608 case MSG_STDERR: 609 if (datalen != sizeof stderrdata) 610 fatalx("bad MSG_STDERR size"); 611 memcpy(&stderrdata, data, sizeof stderrdata); 612 613 client_write(STDERR_FILENO, stderrdata.data, 614 stderrdata.size); 615 break; 616 case MSG_VERSION: 617 if (datalen != 0) 618 fatalx("bad MSG_VERSION size"); 619 620 fprintf(stderr, "protocol version mismatch " 621 "(client %d, server %u)\n", PROTOCOL_VERSION, 622 imsg->hdr.peerid & 0xff); 623 client_exitval = 1; 624 proc_exit(client_proc); 625 break; 626 case MSG_SHELL: 627 if (datalen == 0 || data[datalen - 1] != '\0') 628 fatalx("bad MSG_SHELL string"); 629 630 clear_signals(0); 631 client_exec(data, shellcmd); 632 /* NOTREACHED */ 633 case MSG_DETACH: 634 case MSG_DETACHKILL: 635 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 636 break; 637 case MSG_EXITED: 638 proc_exit(client_proc); 639 break; 640 } 641 } 642 643 /* Dispatch imsgs in attached state (after MSG_READY). */ 644 static void 645 client_dispatch_attached(struct imsg *imsg) 646 { 647 struct sigaction sigact; 648 char *data; 649 ssize_t datalen; 650 651 data = imsg->data; 652 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 653 654 switch (imsg->hdr.type) { 655 case MSG_DETACH: 656 case MSG_DETACHKILL: 657 if (datalen == 0 || data[datalen - 1] != '\0') 658 fatalx("bad MSG_DETACH string"); 659 660 client_exitsession = xstrdup(data); 661 client_exittype = imsg->hdr.type; 662 if (imsg->hdr.type == MSG_DETACHKILL) 663 client_exitreason = CLIENT_EXIT_DETACHED_HUP; 664 else 665 client_exitreason = CLIENT_EXIT_DETACHED; 666 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 667 break; 668 case MSG_EXEC: 669 if (datalen == 0 || data[datalen - 1] != '\0' || 670 strlen(data) + 1 == (size_t)datalen) 671 fatalx("bad MSG_EXEC string"); 672 client_execcmd = xstrdup(data); 673 client_execshell = xstrdup(data + strlen(data) + 1); 674 675 client_exittype = imsg->hdr.type; 676 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 677 break; 678 case MSG_EXIT: 679 if (datalen != 0 && datalen != sizeof (int)) 680 fatalx("bad MSG_EXIT size"); 681 682 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 683 client_exitreason = CLIENT_EXIT_EXITED; 684 break; 685 case MSG_EXITED: 686 if (datalen != 0) 687 fatalx("bad MSG_EXITED size"); 688 689 proc_exit(client_proc); 690 break; 691 case MSG_SHUTDOWN: 692 if (datalen != 0) 693 fatalx("bad MSG_SHUTDOWN size"); 694 695 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 696 client_exitreason = CLIENT_EXIT_SERVER_EXITED; 697 client_exitval = 1; 698 break; 699 case MSG_SUSPEND: 700 if (datalen != 0) 701 fatalx("bad MSG_SUSPEND size"); 702 703 memset(&sigact, 0, sizeof sigact); 704 sigemptyset(&sigact.sa_mask); 705 sigact.sa_flags = SA_RESTART; 706 sigact.sa_handler = SIG_DFL; 707 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 708 fatal("sigaction failed"); 709 kill(getpid(), SIGTSTP); 710 break; 711 case MSG_LOCK: 712 if (datalen == 0 || data[datalen - 1] != '\0') 713 fatalx("bad MSG_LOCK string"); 714 715 system(data); 716 proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0); 717 break; 718 } 719 } 720