1 /* $OpenBSD: client.c,v 1.159 2023/01/06 07:09:27 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/socket.h> 21 #include <sys/uio.h> 22 #include <sys/un.h> 23 #include <sys/wait.h> 24 25 #include <errno.h> 26 #include <event.h> 27 #include <fcntl.h> 28 #include <imsg.h> 29 #include <signal.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <unistd.h> 33 34 #include "tmux.h" 35 36 static struct tmuxproc *client_proc; 37 static struct tmuxpeer *client_peer; 38 static uint64_t client_flags; 39 static int client_suspended; 40 static enum { 41 CLIENT_EXIT_NONE, 42 CLIENT_EXIT_DETACHED, 43 CLIENT_EXIT_DETACHED_HUP, 44 CLIENT_EXIT_LOST_TTY, 45 CLIENT_EXIT_TERMINATED, 46 CLIENT_EXIT_LOST_SERVER, 47 CLIENT_EXIT_EXITED, 48 CLIENT_EXIT_SERVER_EXITED, 49 CLIENT_EXIT_MESSAGE_PROVIDED 50 } client_exitreason = CLIENT_EXIT_NONE; 51 static int client_exitflag; 52 static int client_exitval; 53 static enum msgtype client_exittype; 54 static const char *client_exitsession; 55 static char *client_exitmessage; 56 static const char *client_execshell; 57 static const char *client_execcmd; 58 static int client_attached; 59 static struct client_files client_files = RB_INITIALIZER(&client_files); 60 61 static __dead void client_exec(const char *,const char *); 62 static int client_get_lock(char *); 63 static int client_connect(struct event_base *, const char *, 64 uint64_t); 65 static void client_send_identify(const char *, const char *, 66 char **, u_int, const char *, int); 67 static void client_signal(int); 68 static void client_dispatch(struct imsg *, void *); 69 static void client_dispatch_attached(struct imsg *); 70 static void client_dispatch_wait(struct imsg *); 71 static const char *client_exit_message(void); 72 73 /* 74 * Get server create lock. If already held then server start is happening in 75 * another client, so block until the lock is released and return -2 to 76 * retry. Return -1 on failure to continue and start the server anyway. 77 */ 78 static int 79 client_get_lock(char *lockfile) 80 { 81 int lockfd; 82 83 log_debug("lock file is %s", lockfile); 84 85 if ((lockfd = open(lockfile, O_WRONLY|O_CREAT, 0600)) == -1) { 86 log_debug("open failed: %s", strerror(errno)); 87 return (-1); 88 } 89 90 if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) { 91 log_debug("flock failed: %s", strerror(errno)); 92 if (errno != EAGAIN) 93 return (lockfd); 94 while (flock(lockfd, LOCK_EX) == -1 && errno == EINTR) 95 /* nothing */; 96 close(lockfd); 97 return (-2); 98 } 99 log_debug("flock succeeded"); 100 101 return (lockfd); 102 } 103 104 /* Connect client to server. */ 105 static int 106 client_connect(struct event_base *base, const char *path, uint64_t flags) 107 { 108 struct sockaddr_un sa; 109 size_t size; 110 int fd, lockfd = -1, locked = 0; 111 char *lockfile = NULL; 112 113 memset(&sa, 0, sizeof sa); 114 sa.sun_family = AF_UNIX; 115 size = strlcpy(sa.sun_path, path, sizeof sa.sun_path); 116 if (size >= sizeof sa.sun_path) { 117 errno = ENAMETOOLONG; 118 return (-1); 119 } 120 log_debug("socket is %s", path); 121 122 retry: 123 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 124 return (-1); 125 126 log_debug("trying connect"); 127 if (connect(fd, (struct sockaddr *)&sa, sizeof sa) == -1) { 128 log_debug("connect failed: %s", strerror(errno)); 129 if (errno != ECONNREFUSED && errno != ENOENT) 130 goto failed; 131 if (flags & CLIENT_NOSTARTSERVER) 132 goto failed; 133 if (~flags & CLIENT_STARTSERVER) 134 goto failed; 135 close(fd); 136 137 if (!locked) { 138 xasprintf(&lockfile, "%s.lock", path); 139 if ((lockfd = client_get_lock(lockfile)) < 0) { 140 log_debug("didn't get lock (%d)", lockfd); 141 142 free(lockfile); 143 lockfile = NULL; 144 145 if (lockfd == -2) 146 goto retry; 147 } 148 log_debug("got lock (%d)", lockfd); 149 150 /* 151 * Always retry at least once, even if we got the lock, 152 * because another client could have taken the lock, 153 * started the server and released the lock between our 154 * connect() and flock(). 155 */ 156 locked = 1; 157 goto retry; 158 } 159 160 if (lockfd >= 0 && unlink(path) != 0 && errno != ENOENT) { 161 free(lockfile); 162 close(lockfd); 163 return (-1); 164 } 165 fd = server_start(client_proc, flags, base, lockfd, lockfile); 166 } 167 168 if (locked && lockfd >= 0) { 169 free(lockfile); 170 close(lockfd); 171 } 172 setblocking(fd, 0); 173 return (fd); 174 175 failed: 176 if (locked) { 177 free(lockfile); 178 close(lockfd); 179 } 180 close(fd); 181 return (-1); 182 } 183 184 /* Get exit string from reason number. */ 185 const char * 186 client_exit_message(void) 187 { 188 static char msg[256]; 189 190 switch (client_exitreason) { 191 case CLIENT_EXIT_NONE: 192 break; 193 case CLIENT_EXIT_DETACHED: 194 if (client_exitsession != NULL) { 195 xsnprintf(msg, sizeof msg, "detached " 196 "(from session %s)", client_exitsession); 197 return (msg); 198 } 199 return ("detached"); 200 case CLIENT_EXIT_DETACHED_HUP: 201 if (client_exitsession != NULL) { 202 xsnprintf(msg, sizeof msg, "detached and SIGHUP " 203 "(from session %s)", client_exitsession); 204 return (msg); 205 } 206 return ("detached and SIGHUP"); 207 case CLIENT_EXIT_LOST_TTY: 208 return ("lost tty"); 209 case CLIENT_EXIT_TERMINATED: 210 return ("terminated"); 211 case CLIENT_EXIT_LOST_SERVER: 212 return ("server exited unexpectedly"); 213 case CLIENT_EXIT_EXITED: 214 return ("exited"); 215 case CLIENT_EXIT_SERVER_EXITED: 216 return ("server exited"); 217 case CLIENT_EXIT_MESSAGE_PROVIDED: 218 return (client_exitmessage); 219 } 220 return ("unknown reason"); 221 } 222 223 /* Exit if all streams flushed. */ 224 static void 225 client_exit(void) 226 { 227 if (!file_write_left(&client_files)) 228 proc_exit(client_proc); 229 } 230 231 /* Client main loop. */ 232 int 233 client_main(struct event_base *base, int argc, char **argv, uint64_t flags, 234 int feat) 235 { 236 struct cmd_parse_result *pr; 237 struct msg_command *data; 238 int fd, i; 239 const char *ttynam, *termname, *cwd; 240 pid_t ppid; 241 enum msgtype msg; 242 struct termios tio, saved_tio; 243 size_t size, linesize = 0; 244 ssize_t linelen; 245 char *line = NULL, **caps = NULL, *cause; 246 u_int ncaps = 0; 247 struct args_value *values; 248 249 /* Ignore SIGCHLD now or daemon() in the server will leave a zombie. */ 250 signal(SIGCHLD, SIG_IGN); 251 252 /* Set up the initial command. */ 253 if (shell_command != NULL) { 254 msg = MSG_SHELL; 255 flags |= CLIENT_STARTSERVER; 256 } else if (argc == 0) { 257 msg = MSG_COMMAND; 258 flags |= CLIENT_STARTSERVER; 259 } else { 260 msg = MSG_COMMAND; 261 262 /* 263 * It's annoying parsing the command string twice (in client 264 * and later in server) but it is necessary to get the start 265 * server flag. 266 */ 267 values = args_from_vector(argc, argv); 268 pr = cmd_parse_from_arguments(values, argc, NULL); 269 if (pr->status == CMD_PARSE_SUCCESS) { 270 if (cmd_list_any_have(pr->cmdlist, CMD_STARTSERVER)) 271 flags |= CLIENT_STARTSERVER; 272 cmd_list_free(pr->cmdlist); 273 } else 274 free(pr->error); 275 args_free_values(values, argc); 276 free(values); 277 } 278 279 /* Create client process structure (starts logging). */ 280 client_proc = proc_start("client"); 281 proc_set_signals(client_proc, client_signal); 282 283 /* Save the flags. */ 284 client_flags = flags; 285 log_debug("flags are %#llx", (unsigned long long)client_flags); 286 287 /* Initialize the client socket and start the server. */ 288 fd = client_connect(base, socket_path, client_flags); 289 if (fd == -1) { 290 if (errno == ECONNREFUSED) { 291 fprintf(stderr, "no server running on %s\n", 292 socket_path); 293 } else { 294 fprintf(stderr, "error connecting to %s (%s)\n", 295 socket_path, strerror(errno)); 296 } 297 return (1); 298 } 299 client_peer = proc_add_peer(client_proc, fd, client_dispatch, NULL); 300 301 /* Save these before pledge(). */ 302 if ((cwd = find_cwd()) == NULL && (cwd = find_home()) == NULL) 303 cwd = "/"; 304 if ((ttynam = ttyname(STDIN_FILENO)) == NULL) 305 ttynam = ""; 306 if ((termname = getenv("TERM")) == NULL) 307 termname = ""; 308 309 /* 310 * Drop privileges for client. "proc exec" is needed for -c and for 311 * locking (which uses system(3)). 312 * 313 * "tty" is needed to restore termios(4) and also for some reason -CC 314 * does not work properly without it (input is not recognised). 315 * 316 * "sendfd" is dropped later in client_dispatch_wait(). 317 */ 318 if (pledge( 319 "stdio rpath wpath cpath unix sendfd proc exec tty", 320 NULL) != 0) 321 fatal("pledge failed"); 322 323 /* Load terminfo entry if any. */ 324 if (isatty(STDIN_FILENO) && 325 *termname != '\0' && 326 tty_term_read_list(termname, STDIN_FILENO, &caps, &ncaps, 327 &cause) != 0) { 328 fprintf(stderr, "%s\n", cause); 329 free(cause); 330 return (1); 331 } 332 333 /* Free stuff that is not used in the client. */ 334 if (ptm_fd != -1) 335 close(ptm_fd); 336 options_free(global_options); 337 options_free(global_s_options); 338 options_free(global_w_options); 339 environ_free(global_environ); 340 341 /* Set up control mode. */ 342 if (client_flags & CLIENT_CONTROLCONTROL) { 343 if (tcgetattr(STDIN_FILENO, &saved_tio) != 0) { 344 fprintf(stderr, "tcgetattr failed: %s\n", 345 strerror(errno)); 346 return (1); 347 } 348 cfmakeraw(&tio); 349 tio.c_iflag = ICRNL|IXANY; 350 tio.c_oflag = OPOST|ONLCR; 351 tio.c_lflag = NOKERNINFO; 352 tio.c_cflag = CREAD|CS8|HUPCL; 353 tio.c_cc[VMIN] = 1; 354 tio.c_cc[VTIME] = 0; 355 cfsetispeed(&tio, cfgetispeed(&saved_tio)); 356 cfsetospeed(&tio, cfgetospeed(&saved_tio)); 357 tcsetattr(STDIN_FILENO, TCSANOW, &tio); 358 } 359 360 /* Send identify messages. */ 361 client_send_identify(ttynam, termname, caps, ncaps, cwd, feat); 362 tty_term_free_list(caps, ncaps); 363 proc_flush_peer(client_peer); 364 365 /* Send first command. */ 366 if (msg == MSG_COMMAND) { 367 /* How big is the command? */ 368 size = 0; 369 for (i = 0; i < argc; i++) 370 size += strlen(argv[i]) + 1; 371 if (size > MAX_IMSGSIZE - (sizeof *data)) { 372 fprintf(stderr, "command too long\n"); 373 return (1); 374 } 375 data = xmalloc((sizeof *data) + size); 376 377 /* Prepare command for server. */ 378 data->argc = argc; 379 if (cmd_pack_argv(argc, argv, (char *)(data + 1), size) != 0) { 380 fprintf(stderr, "command too long\n"); 381 free(data); 382 return (1); 383 } 384 size += sizeof *data; 385 386 /* Send the command. */ 387 if (proc_send(client_peer, msg, -1, data, size) != 0) { 388 fprintf(stderr, "failed to send command\n"); 389 free(data); 390 return (1); 391 } 392 free(data); 393 } else if (msg == MSG_SHELL) 394 proc_send(client_peer, msg, -1, NULL, 0); 395 396 /* Start main loop. */ 397 proc_loop(client_proc, NULL); 398 399 /* Run command if user requested exec, instead of exiting. */ 400 if (client_exittype == MSG_EXEC) { 401 if (client_flags & CLIENT_CONTROLCONTROL) 402 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 403 client_exec(client_execshell, client_execcmd); 404 } 405 406 /* Restore streams to blocking. */ 407 setblocking(STDIN_FILENO, 1); 408 setblocking(STDOUT_FILENO, 1); 409 setblocking(STDERR_FILENO, 1); 410 411 /* Print the exit message, if any, and exit. */ 412 if (client_attached) { 413 if (client_exitreason != CLIENT_EXIT_NONE) 414 printf("[%s]\n", client_exit_message()); 415 416 ppid = getppid(); 417 if (client_exittype == MSG_DETACHKILL && ppid > 1) 418 kill(ppid, SIGHUP); 419 } else if (client_flags & CLIENT_CONTROL) { 420 if (client_exitreason != CLIENT_EXIT_NONE) 421 printf("%%exit %s\n", client_exit_message()); 422 else 423 printf("%%exit\n"); 424 fflush(stdout); 425 if (client_flags & CLIENT_CONTROL_WAITEXIT) { 426 setvbuf(stdin, NULL, _IOLBF, 0); 427 for (;;) { 428 linelen = getline(&line, &linesize, stdin); 429 if (linelen <= 1) 430 break; 431 } 432 free(line); 433 } 434 if (client_flags & CLIENT_CONTROLCONTROL) { 435 printf("\033\\"); 436 fflush(stdout); 437 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio); 438 } 439 } else if (client_exitreason != CLIENT_EXIT_NONE) 440 fprintf(stderr, "%s\n", client_exit_message()); 441 return (client_exitval); 442 } 443 444 /* Send identify messages to server. */ 445 static void 446 client_send_identify(const char *ttynam, const char *termname, char **caps, 447 u_int ncaps, const char *cwd, int feat) 448 { 449 char **ss; 450 size_t sslen; 451 int fd, flags = client_flags; 452 pid_t pid; 453 u_int i; 454 455 proc_send(client_peer, MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags); 456 proc_send(client_peer, MSG_IDENTIFY_LONGFLAGS, -1, &client_flags, 457 sizeof client_flags); 458 459 proc_send(client_peer, MSG_IDENTIFY_TERM, -1, termname, 460 strlen(termname) + 1); 461 proc_send(client_peer, MSG_IDENTIFY_FEATURES, -1, &feat, sizeof feat); 462 463 proc_send(client_peer, MSG_IDENTIFY_TTYNAME, -1, ttynam, 464 strlen(ttynam) + 1); 465 proc_send(client_peer, MSG_IDENTIFY_CWD, -1, cwd, strlen(cwd) + 1); 466 467 for (i = 0; i < ncaps; i++) { 468 proc_send(client_peer, MSG_IDENTIFY_TERMINFO, -1, 469 caps[i], strlen(caps[i]) + 1); 470 } 471 472 if ((fd = dup(STDIN_FILENO)) == -1) 473 fatal("dup failed"); 474 proc_send(client_peer, MSG_IDENTIFY_STDIN, fd, NULL, 0); 475 if ((fd = dup(STDOUT_FILENO)) == -1) 476 fatal("dup failed"); 477 proc_send(client_peer, MSG_IDENTIFY_STDOUT, fd, NULL, 0); 478 479 pid = getpid(); 480 proc_send(client_peer, MSG_IDENTIFY_CLIENTPID, -1, &pid, sizeof pid); 481 482 for (ss = environ; *ss != NULL; ss++) { 483 sslen = strlen(*ss) + 1; 484 if (sslen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) 485 continue; 486 proc_send(client_peer, MSG_IDENTIFY_ENVIRON, -1, *ss, sslen); 487 } 488 489 proc_send(client_peer, MSG_IDENTIFY_DONE, -1, NULL, 0); 490 } 491 492 /* Run command in shell; used for -c. */ 493 static __dead void 494 client_exec(const char *shell, const char *shellcmd) 495 { 496 const char *name, *ptr; 497 char *argv0; 498 499 log_debug("shell %s, command %s", shell, shellcmd); 500 501 ptr = strrchr(shell, '/'); 502 if (ptr != NULL && *(ptr + 1) != '\0') 503 name = ptr + 1; 504 else 505 name = shell; 506 if (client_flags & CLIENT_LOGIN) 507 xasprintf(&argv0, "-%s", name); 508 else 509 xasprintf(&argv0, "%s", name); 510 setenv("SHELL", shell, 1); 511 512 proc_clear_signals(client_proc, 1); 513 514 setblocking(STDIN_FILENO, 1); 515 setblocking(STDOUT_FILENO, 1); 516 setblocking(STDERR_FILENO, 1); 517 closefrom(STDERR_FILENO + 1); 518 519 execl(shell, argv0, "-c", shellcmd, (char *) NULL); 520 fatal("execl failed"); 521 } 522 523 /* Callback to handle signals in the client. */ 524 static void 525 client_signal(int sig) 526 { 527 struct sigaction sigact; 528 int status; 529 530 log_debug("%s: %s", __func__, strsignal(sig)); 531 if (sig == SIGCHLD) 532 waitpid(WAIT_ANY, &status, WNOHANG); 533 else if (!client_attached) { 534 if (sig == SIGTERM || sig == SIGHUP) 535 proc_exit(client_proc); 536 } else { 537 switch (sig) { 538 case SIGHUP: 539 client_exitreason = CLIENT_EXIT_LOST_TTY; 540 client_exitval = 1; 541 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 542 break; 543 case SIGTERM: 544 if (!client_suspended) 545 client_exitreason = CLIENT_EXIT_TERMINATED; 546 client_exitval = 1; 547 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 548 break; 549 case SIGWINCH: 550 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 551 break; 552 case SIGCONT: 553 memset(&sigact, 0, sizeof sigact); 554 sigemptyset(&sigact.sa_mask); 555 sigact.sa_flags = SA_RESTART; 556 sigact.sa_handler = SIG_IGN; 557 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 558 fatal("sigaction failed"); 559 proc_send(client_peer, MSG_WAKEUP, -1, NULL, 0); 560 client_suspended = 0; 561 break; 562 } 563 } 564 } 565 566 /* Callback for file write error or close. */ 567 static void 568 client_file_check_cb(__unused struct client *c, __unused const char *path, 569 __unused int error, __unused int closed, __unused struct evbuffer *buffer, 570 __unused void *data) 571 { 572 if (client_exitflag) 573 client_exit(); 574 } 575 576 /* Callback for client read events. */ 577 static void 578 client_dispatch(struct imsg *imsg, __unused void *arg) 579 { 580 if (imsg == NULL) { 581 if (!client_exitflag) { 582 client_exitreason = CLIENT_EXIT_LOST_SERVER; 583 client_exitval = 1; 584 } 585 proc_exit(client_proc); 586 return; 587 } 588 589 if (client_attached) 590 client_dispatch_attached(imsg); 591 else 592 client_dispatch_wait(imsg); 593 } 594 595 /* Process an exit message. */ 596 static void 597 client_dispatch_exit_message(char *data, size_t datalen) 598 { 599 int retval; 600 601 if (datalen < sizeof retval && datalen != 0) 602 fatalx("bad MSG_EXIT size"); 603 604 if (datalen >= sizeof retval) { 605 memcpy(&retval, data, sizeof retval); 606 client_exitval = retval; 607 } 608 609 if (datalen > sizeof retval) { 610 datalen -= sizeof retval; 611 data += sizeof retval; 612 613 client_exitmessage = xmalloc(datalen); 614 memcpy(client_exitmessage, data, datalen); 615 client_exitmessage[datalen - 1] = '\0'; 616 617 client_exitreason = CLIENT_EXIT_MESSAGE_PROVIDED; 618 } 619 } 620 621 /* Dispatch imsgs when in wait state (before MSG_READY). */ 622 static void 623 client_dispatch_wait(struct imsg *imsg) 624 { 625 char *data; 626 ssize_t datalen; 627 static int pledge_applied; 628 629 /* 630 * "sendfd" is no longer required once all of the identify messages 631 * have been sent. We know the server won't send us anything until that 632 * point (because we don't ask it to), so we can drop "sendfd" once we 633 * get the first message from the server. 634 */ 635 if (!pledge_applied) { 636 if (pledge( 637 "stdio rpath wpath cpath unix proc exec tty", 638 NULL) != 0) 639 fatal("pledge failed"); 640 pledge_applied = 1; 641 } 642 643 data = imsg->data; 644 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 645 646 switch (imsg->hdr.type) { 647 case MSG_EXIT: 648 case MSG_SHUTDOWN: 649 client_dispatch_exit_message(data, datalen); 650 client_exitflag = 1; 651 client_exit(); 652 break; 653 case MSG_READY: 654 if (datalen != 0) 655 fatalx("bad MSG_READY size"); 656 657 client_attached = 1; 658 proc_send(client_peer, MSG_RESIZE, -1, NULL, 0); 659 break; 660 case MSG_VERSION: 661 if (datalen != 0) 662 fatalx("bad MSG_VERSION size"); 663 664 fprintf(stderr, "protocol version mismatch " 665 "(client %d, server %u)\n", PROTOCOL_VERSION, 666 imsg->hdr.peerid & 0xff); 667 client_exitval = 1; 668 proc_exit(client_proc); 669 break; 670 case MSG_FLAGS: 671 if (datalen != sizeof client_flags) 672 fatalx("bad MSG_FLAGS string"); 673 674 memcpy(&client_flags, data, sizeof client_flags); 675 log_debug("new flags are %#llx", 676 (unsigned long long)client_flags); 677 break; 678 case MSG_SHELL: 679 if (datalen == 0 || data[datalen - 1] != '\0') 680 fatalx("bad MSG_SHELL string"); 681 682 client_exec(data, shell_command); 683 /* NOTREACHED */ 684 case MSG_DETACH: 685 case MSG_DETACHKILL: 686 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 687 break; 688 case MSG_EXITED: 689 proc_exit(client_proc); 690 break; 691 case MSG_READ_OPEN: 692 file_read_open(&client_files, client_peer, imsg, 1, 693 !(client_flags & CLIENT_CONTROL), client_file_check_cb, 694 NULL); 695 break; 696 case MSG_READ_CANCEL: 697 file_read_cancel(&client_files, imsg); 698 break; 699 case MSG_WRITE_OPEN: 700 file_write_open(&client_files, client_peer, imsg, 1, 701 !(client_flags & CLIENT_CONTROL), client_file_check_cb, 702 NULL); 703 break; 704 case MSG_WRITE: 705 file_write_data(&client_files, imsg); 706 break; 707 case MSG_WRITE_CLOSE: 708 file_write_close(&client_files, imsg); 709 break; 710 case MSG_OLDSTDERR: 711 case MSG_OLDSTDIN: 712 case MSG_OLDSTDOUT: 713 fprintf(stderr, "server version is too old for client\n"); 714 proc_exit(client_proc); 715 break; 716 } 717 } 718 719 /* Dispatch imsgs in attached state (after MSG_READY). */ 720 static void 721 client_dispatch_attached(struct imsg *imsg) 722 { 723 struct sigaction sigact; 724 char *data; 725 ssize_t datalen; 726 727 data = imsg->data; 728 datalen = imsg->hdr.len - IMSG_HEADER_SIZE; 729 730 switch (imsg->hdr.type) { 731 case MSG_FLAGS: 732 if (datalen != sizeof client_flags) 733 fatalx("bad MSG_FLAGS string"); 734 735 memcpy(&client_flags, data, sizeof client_flags); 736 log_debug("new flags are %#llx", 737 (unsigned long long)client_flags); 738 break; 739 case MSG_DETACH: 740 case MSG_DETACHKILL: 741 if (datalen == 0 || data[datalen - 1] != '\0') 742 fatalx("bad MSG_DETACH string"); 743 744 client_exitsession = xstrdup(data); 745 client_exittype = imsg->hdr.type; 746 if (imsg->hdr.type == MSG_DETACHKILL) 747 client_exitreason = CLIENT_EXIT_DETACHED_HUP; 748 else 749 client_exitreason = CLIENT_EXIT_DETACHED; 750 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 751 break; 752 case MSG_EXEC: 753 if (datalen == 0 || data[datalen - 1] != '\0' || 754 strlen(data) + 1 == (size_t)datalen) 755 fatalx("bad MSG_EXEC string"); 756 client_execcmd = xstrdup(data); 757 client_execshell = xstrdup(data + strlen(data) + 1); 758 759 client_exittype = imsg->hdr.type; 760 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 761 break; 762 case MSG_EXIT: 763 client_dispatch_exit_message(data, datalen); 764 if (client_exitreason == CLIENT_EXIT_NONE) 765 client_exitreason = CLIENT_EXIT_EXITED; 766 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 767 break; 768 case MSG_EXITED: 769 if (datalen != 0) 770 fatalx("bad MSG_EXITED size"); 771 772 proc_exit(client_proc); 773 break; 774 case MSG_SHUTDOWN: 775 if (datalen != 0) 776 fatalx("bad MSG_SHUTDOWN size"); 777 778 proc_send(client_peer, MSG_EXITING, -1, NULL, 0); 779 client_exitreason = CLIENT_EXIT_SERVER_EXITED; 780 client_exitval = 1; 781 break; 782 case MSG_SUSPEND: 783 if (datalen != 0) 784 fatalx("bad MSG_SUSPEND size"); 785 786 memset(&sigact, 0, sizeof sigact); 787 sigemptyset(&sigact.sa_mask); 788 sigact.sa_flags = SA_RESTART; 789 sigact.sa_handler = SIG_DFL; 790 if (sigaction(SIGTSTP, &sigact, NULL) != 0) 791 fatal("sigaction failed"); 792 client_suspended = 1; 793 kill(getpid(), SIGTSTP); 794 break; 795 case MSG_LOCK: 796 if (datalen == 0 || data[datalen - 1] != '\0') 797 fatalx("bad MSG_LOCK string"); 798 799 system(data); 800 proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0); 801 break; 802 } 803 } 804