1 /* $OpenBSD: clientloop.c,v 1.272 2015/02/25 19:54:02 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo (at) cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo (at) cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * The main loop for the interactive session (client side). 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * 15 * Copyright (c) 1999 Theo de Raadt. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * 38 * SSH2 support added by Markus Friedl. 39 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 51 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 52 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 53 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 54 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 55 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 56 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 57 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 58 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 59 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 #include "includes.h" 63 64 #include <sys/param.h> /* MIN MAX */ 65 #include <sys/types.h> 66 #include <sys/ioctl.h> 67 #ifdef HAVE_SYS_STAT_H 68 # include <sys/stat.h> 69 #endif 70 #ifdef HAVE_SYS_TIME_H 71 # include <sys/time.h> 72 #endif 73 #include <sys/socket.h> 74 75 #include <ctype.h> 76 #include <errno.h> 77 #ifdef HAVE_PATHS_H 78 #include <paths.h> 79 #endif 80 #include <signal.h> 81 #include <stdarg.h> 82 #include <stdio.h> 83 #include <stdlib.h> 84 #include <string.h> 85 #include <termios.h> 86 #include <pwd.h> 87 #include <unistd.h> 88 #include <limits.h> 89 90 #include "openbsd-compat/sys-queue.h" 91 #include "xmalloc.h" 92 #include "ssh.h" 93 #include "ssh1.h" 94 #include "ssh2.h" 95 #include "packet.h" 96 #include "buffer.h" 97 #include "compat.h" 98 #include "channels.h" 99 #include "dispatch.h" 100 #include "key.h" 101 #include "cipher.h" 102 #include "kex.h" 103 #include "log.h" 104 #include "misc.h" 105 #include "readconf.h" 106 #include "clientloop.h" 107 #include "sshconnect.h" 108 #include "authfd.h" 109 #include "atomicio.h" 110 #include "sshpty.h" 111 #include "match.h" 112 #include "msg.h" 113 #include "roaming.h" 114 #include "ssherr.h" 115 #include "hostfile.h" 116 117 /* import options */ 118 extern Options options; 119 120 /* Flag indicating that stdin should be redirected from /dev/null. */ 121 extern int stdin_null_flag; 122 123 /* Flag indicating that no shell has been requested */ 124 extern int no_shell_flag; 125 126 /* Control socket */ 127 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 128 129 /* 130 * Name of the host we are connecting to. This is the name given on the 131 * command line, or the HostName specified for the user-supplied name in a 132 * configuration file. 133 */ 134 extern char *host; 135 136 /* 137 * Flag to indicate that we have received a window change signal which has 138 * not yet been processed. This will cause a message indicating the new 139 * window size to be sent to the server a little later. This is volatile 140 * because this is updated in a signal handler. 141 */ 142 static volatile sig_atomic_t received_window_change_signal = 0; 143 static volatile sig_atomic_t received_signal = 0; 144 145 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 146 static int in_non_blocking_mode = 0; 147 148 /* Time when backgrounded control master using ControlPersist should exit */ 149 static time_t control_persist_exit_time = 0; 150 151 /* Common data for the client loop code. */ 152 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 153 static int escape_char1; /* Escape character. (proto1 only) */ 154 static int escape_pending1; /* Last character was an escape (proto1 only) */ 155 static int last_was_cr; /* Last character was a newline. */ 156 static int exit_status; /* Used to store the command exit status. */ 157 static int stdin_eof; /* EOF has been encountered on stderr. */ 158 static Buffer stdin_buffer; /* Buffer for stdin data. */ 159 static Buffer stdout_buffer; /* Buffer for stdout data. */ 160 static Buffer stderr_buffer; /* Buffer for stderr data. */ 161 static u_int buffer_high; /* Soft max buffer size. */ 162 static int connection_in; /* Connection to server (input). */ 163 static int connection_out; /* Connection to server (output). */ 164 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 165 static int session_closed; /* In SSH2: login session closed. */ 166 static int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 167 168 static void client_init_dispatch(void); 169 int session_ident = -1; 170 171 int session_resumed = 0; 172 173 /* Track escape per proto2 channel */ 174 struct escape_filter_ctx { 175 int escape_pending; 176 int escape_char; 177 }; 178 179 /* Context for channel confirmation replies */ 180 struct channel_reply_ctx { 181 const char *request_type; 182 int id; 183 enum confirm_action action; 184 }; 185 186 /* Global request success/failure callbacks */ 187 struct global_confirm { 188 TAILQ_ENTRY(global_confirm) entry; 189 global_confirm_cb *cb; 190 void *ctx; 191 int ref_count; 192 }; 193 TAILQ_HEAD(global_confirms, global_confirm); 194 static struct global_confirms global_confirms = 195 TAILQ_HEAD_INITIALIZER(global_confirms); 196 197 void ssh_process_session2_setup(int, int, int, Buffer *); 198 199 /* Restores stdin to blocking mode. */ 200 201 static void 202 leave_non_blocking(void) 203 { 204 if (in_non_blocking_mode) { 205 unset_nonblock(fileno(stdin)); 206 in_non_blocking_mode = 0; 207 } 208 } 209 210 /* Puts stdin terminal in non-blocking mode. */ 211 212 static void 213 enter_non_blocking(void) 214 { 215 in_non_blocking_mode = 1; 216 set_nonblock(fileno(stdin)); 217 } 218 219 /* 220 * Signal handler for the window change signal (SIGWINCH). This just sets a 221 * flag indicating that the window has changed. 222 */ 223 /*ARGSUSED */ 224 static void 225 window_change_handler(int sig) 226 { 227 received_window_change_signal = 1; 228 signal(SIGWINCH, window_change_handler); 229 } 230 231 /* 232 * Signal handler for signals that cause the program to terminate. These 233 * signals must be trapped to restore terminal modes. 234 */ 235 /*ARGSUSED */ 236 static void 237 signal_handler(int sig) 238 { 239 received_signal = sig; 240 quit_pending = 1; 241 } 242 243 /* 244 * Returns current time in seconds from Jan 1, 1970 with the maximum 245 * available resolution. 246 */ 247 248 static double 249 get_current_time(void) 250 { 251 struct timeval tv; 252 gettimeofday(&tv, NULL); 253 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 254 } 255 256 /* 257 * Sets control_persist_exit_time to the absolute time when the 258 * backgrounded control master should exit due to expiry of the 259 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded 260 * control master process, or if there is no ControlPersist timeout. 261 */ 262 static void 263 set_control_persist_exit_time(void) 264 { 265 if (muxserver_sock == -1 || !options.control_persist 266 || options.control_persist_timeout == 0) { 267 /* not using a ControlPersist timeout */ 268 control_persist_exit_time = 0; 269 } else if (channel_still_open()) { 270 /* some client connections are still open */ 271 if (control_persist_exit_time > 0) 272 debug2("%s: cancel scheduled exit", __func__); 273 control_persist_exit_time = 0; 274 } else if (control_persist_exit_time <= 0) { 275 /* a client connection has recently closed */ 276 control_persist_exit_time = monotime() + 277 (time_t)options.control_persist_timeout; 278 debug2("%s: schedule exit in %d seconds", __func__, 279 options.control_persist_timeout); 280 } 281 /* else we are already counting down to the timeout */ 282 } 283 284 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" 285 static int 286 client_x11_display_valid(const char *display) 287 { 288 size_t i, dlen; 289 290 dlen = strlen(display); 291 for (i = 0; i < dlen; i++) { 292 if (!isalnum((u_char)display[i]) && 293 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 294 debug("Invalid character '%c' in DISPLAY", display[i]); 295 return 0; 296 } 297 } 298 return 1; 299 } 300 301 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 302 void 303 client_x11_get_proto(const char *display, const char *xauth_path, 304 u_int trusted, u_int timeout, char **_proto, char **_data) 305 { 306 char cmd[1024]; 307 char line[512]; 308 char xdisplay[512]; 309 static char proto[512], data[512]; 310 FILE *f; 311 int got_data = 0, generated = 0, do_unlink = 0, i; 312 char *xauthdir, *xauthfile; 313 struct stat st; 314 u_int now; 315 316 xauthdir = xauthfile = NULL; 317 *_proto = proto; 318 *_data = data; 319 proto[0] = data[0] = '\0'; 320 321 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 322 debug("No xauth program."); 323 } else if (!client_x11_display_valid(display)) { 324 logit("DISPLAY '%s' invalid, falling back to fake xauth data", 325 display); 326 } else { 327 if (display == NULL) { 328 debug("x11_get_proto: DISPLAY not set"); 329 return; 330 } 331 /* 332 * Handle FamilyLocal case where $DISPLAY does 333 * not match an authorization entry. For this we 334 * just try "xauth list unix:displaynum.screennum". 335 * XXX: "localhost" match to determine FamilyLocal 336 * is not perfect. 337 */ 338 if (strncmp(display, "localhost:", 10) == 0) { 339 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 340 display + 10); 341 display = xdisplay; 342 } 343 if (trusted == 0) { 344 xauthdir = xmalloc(PATH_MAX); 345 xauthfile = xmalloc(PATH_MAX); 346 mktemp_proto(xauthdir, PATH_MAX); 347 if (mkdtemp(xauthdir) != NULL) { 348 do_unlink = 1; 349 snprintf(xauthfile, PATH_MAX, "%s/xauthfile", 350 xauthdir); 351 snprintf(cmd, sizeof(cmd), 352 "%s -f %s generate %s " SSH_X11_PROTO 353 " untrusted timeout %u 2>" _PATH_DEVNULL, 354 xauth_path, xauthfile, display, timeout); 355 debug2("x11_get_proto: %s", cmd); 356 if (system(cmd) == 0) 357 generated = 1; 358 if (x11_refuse_time == 0) { 359 now = monotime() + 1; 360 if (UINT_MAX - timeout < now) 361 x11_refuse_time = UINT_MAX; 362 else 363 x11_refuse_time = now + timeout; 364 } 365 } 366 } 367 368 /* 369 * When in untrusted mode, we read the cookie only if it was 370 * successfully generated as an untrusted one in the step 371 * above. 372 */ 373 if (trusted || generated) { 374 snprintf(cmd, sizeof(cmd), 375 "%s %s%s list %s 2>" _PATH_DEVNULL, 376 xauth_path, 377 generated ? "-f " : "" , 378 generated ? xauthfile : "", 379 display); 380 debug2("x11_get_proto: %s", cmd); 381 f = popen(cmd, "r"); 382 if (f && fgets(line, sizeof(line), f) && 383 sscanf(line, "%*s %511s %511s", proto, data) == 2) 384 got_data = 1; 385 if (f) 386 pclose(f); 387 } else 388 error("Warning: untrusted X11 forwarding setup failed: " 389 "xauth key data not generated"); 390 } 391 392 if (do_unlink) { 393 unlink(xauthfile); 394 rmdir(xauthdir); 395 } 396 free(xauthdir); 397 free(xauthfile); 398 399 /* 400 * If we didn't get authentication data, just make up some 401 * data. The forwarding code will check the validity of the 402 * response anyway, and substitute this data. The X11 403 * server, however, will ignore this fake data and use 404 * whatever authentication mechanisms it was using otherwise 405 * for the local connection. 406 */ 407 if (!got_data) { 408 u_int32_t rnd = 0; 409 410 logit("Warning: No xauth data; " 411 "using fake authentication data for X11 forwarding."); 412 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 413 for (i = 0; i < 16; i++) { 414 if (i % 4 == 0) 415 rnd = arc4random(); 416 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 417 rnd & 0xff); 418 rnd >>= 8; 419 } 420 } 421 } 422 423 /* 424 * This is called when the interactive is entered. This checks if there is 425 * an EOF coming on stdin. We must check this explicitly, as select() does 426 * not appear to wake up when redirecting from /dev/null. 427 */ 428 429 static void 430 client_check_initial_eof_on_stdin(void) 431 { 432 int len; 433 char buf[1]; 434 435 /* 436 * If standard input is to be "redirected from /dev/null", we simply 437 * mark that we have seen an EOF and send an EOF message to the 438 * server. Otherwise, we try to read a single character; it appears 439 * that for some files, such /dev/null, select() never wakes up for 440 * read for this descriptor, which means that we never get EOF. This 441 * way we will get the EOF if stdin comes from /dev/null or similar. 442 */ 443 if (stdin_null_flag) { 444 /* Fake EOF on stdin. */ 445 debug("Sending eof."); 446 stdin_eof = 1; 447 packet_start(SSH_CMSG_EOF); 448 packet_send(); 449 } else { 450 enter_non_blocking(); 451 452 /* Check for immediate EOF on stdin. */ 453 len = read(fileno(stdin), buf, 1); 454 if (len == 0) { 455 /* 456 * EOF. Record that we have seen it and send 457 * EOF to server. 458 */ 459 debug("Sending eof."); 460 stdin_eof = 1; 461 packet_start(SSH_CMSG_EOF); 462 packet_send(); 463 } else if (len > 0) { 464 /* 465 * Got data. We must store the data in the buffer, 466 * and also process it as an escape character if 467 * appropriate. 468 */ 469 if ((u_char) buf[0] == escape_char1) 470 escape_pending1 = 1; 471 else 472 buffer_append(&stdin_buffer, buf, 1); 473 } 474 leave_non_blocking(); 475 } 476 } 477 478 479 /* 480 * Make packets from buffered stdin data, and buffer them for sending to the 481 * connection. 482 */ 483 484 static void 485 client_make_packets_from_stdin_data(void) 486 { 487 u_int len; 488 489 /* Send buffered stdin data to the server. */ 490 while (buffer_len(&stdin_buffer) > 0 && 491 packet_not_very_much_data_to_write()) { 492 len = buffer_len(&stdin_buffer); 493 /* Keep the packets at reasonable size. */ 494 if (len > packet_get_maxsize()) 495 len = packet_get_maxsize(); 496 packet_start(SSH_CMSG_STDIN_DATA); 497 packet_put_string(buffer_ptr(&stdin_buffer), len); 498 packet_send(); 499 buffer_consume(&stdin_buffer, len); 500 /* If we have a pending EOF, send it now. */ 501 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 502 packet_start(SSH_CMSG_EOF); 503 packet_send(); 504 } 505 } 506 } 507 508 /* 509 * Checks if the client window has changed, and sends a packet about it to 510 * the server if so. The actual change is detected elsewhere (by a software 511 * interrupt on Unix); this just checks the flag and sends a message if 512 * appropriate. 513 */ 514 515 static void 516 client_check_window_change(void) 517 { 518 struct winsize ws; 519 520 if (! received_window_change_signal) 521 return; 522 /** XXX race */ 523 received_window_change_signal = 0; 524 525 debug2("client_check_window_change: changed"); 526 527 if (compat20) { 528 channel_send_window_changes(); 529 } else { 530 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 531 return; 532 packet_start(SSH_CMSG_WINDOW_SIZE); 533 packet_put_int((u_int)ws.ws_row); 534 packet_put_int((u_int)ws.ws_col); 535 packet_put_int((u_int)ws.ws_xpixel); 536 packet_put_int((u_int)ws.ws_ypixel); 537 packet_send(); 538 } 539 } 540 541 static int 542 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 543 { 544 struct global_confirm *gc; 545 546 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 547 return 0; 548 if (gc->cb != NULL) 549 gc->cb(type, seq, gc->ctx); 550 if (--gc->ref_count <= 0) { 551 TAILQ_REMOVE(&global_confirms, gc, entry); 552 explicit_bzero(gc, sizeof(*gc)); 553 free(gc); 554 } 555 556 packet_set_alive_timeouts(0); 557 return 0; 558 } 559 560 static void 561 server_alive_check(void) 562 { 563 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 564 logit("Timeout, server %s not responding.", host); 565 cleanup_exit(255); 566 } 567 packet_start(SSH2_MSG_GLOBAL_REQUEST); 568 packet_put_cstring("keepalive (at) openssh.com"); 569 packet_put_char(1); /* boolean: want reply */ 570 packet_send(); 571 /* Insert an empty placeholder to maintain ordering */ 572 client_register_global_confirm(NULL, NULL); 573 } 574 575 /* 576 * Waits until the client can do something (some data becomes available on 577 * one of the file descriptors). 578 */ 579 static void 580 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 581 int *maxfdp, u_int *nallocp, int rekeying) 582 { 583 struct timeval tv, *tvp; 584 int timeout_secs; 585 time_t minwait_secs = 0, server_alive_time = 0, now = monotime(); 586 int ret; 587 588 /* Add any selections by the channel mechanism. */ 589 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 590 &minwait_secs, rekeying); 591 592 if (!compat20) { 593 /* Read from the connection, unless our buffers are full. */ 594 if (buffer_len(&stdout_buffer) < buffer_high && 595 buffer_len(&stderr_buffer) < buffer_high && 596 channel_not_very_much_buffered_data()) 597 FD_SET(connection_in, *readsetp); 598 /* 599 * Read from stdin, unless we have seen EOF or have very much 600 * buffered data to send to the server. 601 */ 602 if (!stdin_eof && packet_not_very_much_data_to_write()) 603 FD_SET(fileno(stdin), *readsetp); 604 605 /* Select stdout/stderr if have data in buffer. */ 606 if (buffer_len(&stdout_buffer) > 0) 607 FD_SET(fileno(stdout), *writesetp); 608 if (buffer_len(&stderr_buffer) > 0) 609 FD_SET(fileno(stderr), *writesetp); 610 } else { 611 /* channel_prepare_select could have closed the last channel */ 612 if (session_closed && !channel_still_open() && 613 !packet_have_data_to_write()) { 614 /* clear mask since we did not call select() */ 615 memset(*readsetp, 0, *nallocp); 616 memset(*writesetp, 0, *nallocp); 617 return; 618 } else { 619 FD_SET(connection_in, *readsetp); 620 } 621 } 622 623 /* Select server connection if have data to write to the server. */ 624 if (packet_have_data_to_write()) 625 FD_SET(connection_out, *writesetp); 626 627 /* 628 * Wait for something to happen. This will suspend the process until 629 * some selected descriptor can be read, written, or has some other 630 * event pending, or a timeout expires. 631 */ 632 633 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 634 if (options.server_alive_interval > 0 && compat20) { 635 timeout_secs = options.server_alive_interval; 636 server_alive_time = now + options.server_alive_interval; 637 } 638 if (options.rekey_interval > 0 && compat20 && !rekeying) 639 timeout_secs = MIN(timeout_secs, packet_get_rekey_timeout()); 640 set_control_persist_exit_time(); 641 if (control_persist_exit_time > 0) { 642 timeout_secs = MIN(timeout_secs, 643 control_persist_exit_time - now); 644 if (timeout_secs < 0) 645 timeout_secs = 0; 646 } 647 if (minwait_secs != 0) 648 timeout_secs = MIN(timeout_secs, (int)minwait_secs); 649 if (timeout_secs == INT_MAX) 650 tvp = NULL; 651 else { 652 tv.tv_sec = timeout_secs; 653 tv.tv_usec = 0; 654 tvp = &tv; 655 } 656 657 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 658 if (ret < 0) { 659 char buf[100]; 660 661 /* 662 * We have to clear the select masks, because we return. 663 * We have to return, because the mainloop checks for the flags 664 * set by the signal handlers. 665 */ 666 memset(*readsetp, 0, *nallocp); 667 memset(*writesetp, 0, *nallocp); 668 669 if (errno == EINTR) 670 return; 671 /* Note: we might still have data in the buffers. */ 672 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 673 buffer_append(&stderr_buffer, buf, strlen(buf)); 674 quit_pending = 1; 675 } else if (ret == 0) { 676 /* 677 * Timeout. Could have been either keepalive or rekeying. 678 * Keepalive we check here, rekeying is checked in clientloop. 679 */ 680 if (server_alive_time != 0 && server_alive_time <= monotime()) 681 server_alive_check(); 682 } 683 684 } 685 686 static void 687 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 688 { 689 /* Flush stdout and stderr buffers. */ 690 if (buffer_len(bout) > 0) 691 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 692 buffer_len(bout)); 693 if (buffer_len(berr) > 0) 694 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 695 buffer_len(berr)); 696 697 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 698 699 /* 700 * Free (and clear) the buffer to reduce the amount of data that gets 701 * written to swap. 702 */ 703 buffer_free(bin); 704 buffer_free(bout); 705 buffer_free(berr); 706 707 /* Send the suspend signal to the program itself. */ 708 kill(getpid(), SIGTSTP); 709 710 /* Reset window sizes in case they have changed */ 711 received_window_change_signal = 1; 712 713 /* OK, we have been continued by the user. Reinitialize buffers. */ 714 buffer_init(bin); 715 buffer_init(bout); 716 buffer_init(berr); 717 718 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 719 } 720 721 static void 722 client_process_net_input(fd_set *readset) 723 { 724 int len, cont = 0; 725 char buf[SSH_IOBUFSZ]; 726 727 /* 728 * Read input from the server, and add any such data to the buffer of 729 * the packet subsystem. 730 */ 731 if (FD_ISSET(connection_in, readset)) { 732 /* Read as much as possible. */ 733 len = roaming_read(connection_in, buf, sizeof(buf), &cont); 734 if (len == 0 && cont == 0) { 735 /* 736 * Received EOF. The remote host has closed the 737 * connection. 738 */ 739 snprintf(buf, sizeof buf, 740 "Connection to %.300s closed by remote host.\r\n", 741 host); 742 buffer_append(&stderr_buffer, buf, strlen(buf)); 743 quit_pending = 1; 744 return; 745 } 746 /* 747 * There is a kernel bug on Solaris that causes select to 748 * sometimes wake up even though there is no data available. 749 */ 750 if (len < 0 && 751 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 752 len = 0; 753 754 if (len < 0) { 755 /* 756 * An error has encountered. Perhaps there is a 757 * network problem. 758 */ 759 snprintf(buf, sizeof buf, 760 "Read from remote host %.300s: %.100s\r\n", 761 host, strerror(errno)); 762 buffer_append(&stderr_buffer, buf, strlen(buf)); 763 quit_pending = 1; 764 return; 765 } 766 packet_process_incoming(buf, len); 767 } 768 } 769 770 static void 771 client_status_confirm(int type, Channel *c, void *ctx) 772 { 773 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 774 char errmsg[256]; 775 int tochan; 776 777 /* 778 * If a TTY was explicitly requested, then a failure to allocate 779 * one is fatal. 780 */ 781 if (cr->action == CONFIRM_TTY && 782 (options.request_tty == REQUEST_TTY_FORCE || 783 options.request_tty == REQUEST_TTY_YES)) 784 cr->action = CONFIRM_CLOSE; 785 786 /* XXX supress on mux _client_ quietmode */ 787 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 788 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 789 790 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 791 debug2("%s request accepted on channel %d", 792 cr->request_type, c->self); 793 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 794 if (tochan) { 795 snprintf(errmsg, sizeof(errmsg), 796 "%s request failed\r\n", cr->request_type); 797 } else { 798 snprintf(errmsg, sizeof(errmsg), 799 "%s request failed on channel %d", 800 cr->request_type, c->self); 801 } 802 /* If error occurred on primary session channel, then exit */ 803 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 804 fatal("%s", errmsg); 805 /* 806 * If error occurred on mux client, append to 807 * their stderr. 808 */ 809 if (tochan) { 810 buffer_append(&c->extended, errmsg, 811 strlen(errmsg)); 812 } else 813 error("%s", errmsg); 814 if (cr->action == CONFIRM_TTY) { 815 /* 816 * If a TTY allocation error occurred, then arrange 817 * for the correct TTY to leave raw mode. 818 */ 819 if (c->self == session_ident) 820 leave_raw_mode(0); 821 else 822 mux_tty_alloc_failed(c); 823 } else if (cr->action == CONFIRM_CLOSE) { 824 chan_read_failed(c); 825 chan_write_failed(c); 826 } 827 } 828 free(cr); 829 } 830 831 static void 832 client_abandon_status_confirm(Channel *c, void *ctx) 833 { 834 free(ctx); 835 } 836 837 void 838 client_expect_confirm(int id, const char *request, 839 enum confirm_action action) 840 { 841 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 842 843 cr->request_type = request; 844 cr->action = action; 845 846 channel_register_status_confirm(id, client_status_confirm, 847 client_abandon_status_confirm, cr); 848 } 849 850 void 851 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 852 { 853 struct global_confirm *gc, *last_gc; 854 855 /* Coalesce identical callbacks */ 856 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 857 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 858 if (++last_gc->ref_count >= INT_MAX) 859 fatal("%s: last_gc->ref_count = %d", 860 __func__, last_gc->ref_count); 861 return; 862 } 863 864 gc = xcalloc(1, sizeof(*gc)); 865 gc->cb = cb; 866 gc->ctx = ctx; 867 gc->ref_count = 1; 868 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 869 } 870 871 static void 872 process_cmdline(void) 873 { 874 void (*handler)(int); 875 char *s, *cmd; 876 int ok, delete = 0, local = 0, remote = 0, dynamic = 0; 877 struct Forward fwd; 878 879 memset(&fwd, 0, sizeof(fwd)); 880 881 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 882 handler = signal(SIGINT, SIG_IGN); 883 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 884 if (s == NULL) 885 goto out; 886 while (isspace((u_char)*s)) 887 s++; 888 if (*s == '-') 889 s++; /* Skip cmdline '-', if any */ 890 if (*s == '\0') 891 goto out; 892 893 if (*s == 'h' || *s == 'H' || *s == '?') { 894 logit("Commands:"); 895 logit(" -L[bind_address:]port:host:hostport " 896 "Request local forward"); 897 logit(" -R[bind_address:]port:host:hostport " 898 "Request remote forward"); 899 logit(" -D[bind_address:]port " 900 "Request dynamic forward"); 901 logit(" -KL[bind_address:]port " 902 "Cancel local forward"); 903 logit(" -KR[bind_address:]port " 904 "Cancel remote forward"); 905 logit(" -KD[bind_address:]port " 906 "Cancel dynamic forward"); 907 if (!options.permit_local_command) 908 goto out; 909 logit(" !args " 910 "Execute local command"); 911 goto out; 912 } 913 914 if (*s == '!' && options.permit_local_command) { 915 s++; 916 ssh_local_cmd(s); 917 goto out; 918 } 919 920 if (*s == 'K') { 921 delete = 1; 922 s++; 923 } 924 if (*s == 'L') 925 local = 1; 926 else if (*s == 'R') 927 remote = 1; 928 else if (*s == 'D') 929 dynamic = 1; 930 else { 931 logit("Invalid command."); 932 goto out; 933 } 934 935 if (delete && !compat20) { 936 logit("Not supported for SSH protocol version 1."); 937 goto out; 938 } 939 940 while (isspace((u_char)*++s)) 941 ; 942 943 /* XXX update list of forwards in options */ 944 if (delete) { 945 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ 946 if (!parse_forward(&fwd, s, 1, 0)) { 947 logit("Bad forwarding close specification."); 948 goto out; 949 } 950 if (remote) 951 ok = channel_request_rforward_cancel(&fwd) == 0; 952 else if (dynamic) 953 ok = channel_cancel_lport_listener(&fwd, 954 0, &options.fwd_opts) > 0; 955 else 956 ok = channel_cancel_lport_listener(&fwd, 957 CHANNEL_CANCEL_PORT_STATIC, 958 &options.fwd_opts) > 0; 959 if (!ok) { 960 logit("Unkown port forwarding."); 961 goto out; 962 } 963 logit("Canceled forwarding."); 964 } else { 965 if (!parse_forward(&fwd, s, dynamic, remote)) { 966 logit("Bad forwarding specification."); 967 goto out; 968 } 969 if (local || dynamic) { 970 if (!channel_setup_local_fwd_listener(&fwd, 971 &options.fwd_opts)) { 972 logit("Port forwarding failed."); 973 goto out; 974 } 975 } else { 976 if (channel_request_remote_forwarding(&fwd) < 0) { 977 logit("Port forwarding failed."); 978 goto out; 979 } 980 } 981 logit("Forwarding port."); 982 } 983 984 out: 985 signal(SIGINT, handler); 986 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 987 free(cmd); 988 free(fwd.listen_host); 989 free(fwd.listen_path); 990 free(fwd.connect_host); 991 free(fwd.connect_path); 992 } 993 994 /* reasons to suppress output of an escape command in help output */ 995 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 996 #define SUPPRESS_PROTO1 1 /* don't show in protocol 1 sessions */ 997 #define SUPPRESS_MUXCLIENT 2 /* don't show in mux client sessions */ 998 #define SUPPRESS_MUXMASTER 4 /* don't show in mux master sessions */ 999 #define SUPPRESS_SYSLOG 8 /* don't show when logging to syslog */ 1000 struct escape_help_text { 1001 const char *cmd; 1002 const char *text; 1003 unsigned int flags; 1004 }; 1005 static struct escape_help_text esc_txt[] = { 1006 {".", "terminate session", SUPPRESS_MUXMASTER}, 1007 {".", "terminate connection (and any multiplexed sessions)", 1008 SUPPRESS_MUXCLIENT}, 1009 {"B", "send a BREAK to the remote system", SUPPRESS_PROTO1}, 1010 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 1011 {"R", "request rekey", SUPPRESS_PROTO1}, 1012 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 1013 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 1014 {"#", "list forwarded connections", SUPPRESS_NEVER}, 1015 {"&", "background ssh (when waiting for connections to terminate)", 1016 SUPPRESS_MUXCLIENT}, 1017 {"?", "this message", SUPPRESS_NEVER}, 1018 }; 1019 1020 static void 1021 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client, 1022 int using_stderr) 1023 { 1024 unsigned int i, suppress_flags; 1025 char string[1024]; 1026 1027 snprintf(string, sizeof string, "%c?\r\n" 1028 "Supported escape sequences:\r\n", escape_char); 1029 buffer_append(b, string, strlen(string)); 1030 1031 suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) | 1032 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 1033 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 1034 (using_stderr ? 0 : SUPPRESS_SYSLOG); 1035 1036 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 1037 if (esc_txt[i].flags & suppress_flags) 1038 continue; 1039 snprintf(string, sizeof string, " %c%-3s - %s\r\n", 1040 escape_char, esc_txt[i].cmd, esc_txt[i].text); 1041 buffer_append(b, string, strlen(string)); 1042 } 1043 1044 snprintf(string, sizeof string, 1045 " %c%c - send the escape character by typing it twice\r\n" 1046 "(Note that escapes are only recognized immediately after " 1047 "newline.)\r\n", escape_char, escape_char); 1048 buffer_append(b, string, strlen(string)); 1049 } 1050 1051 /* 1052 * Process the characters one by one, call with c==NULL for proto1 case. 1053 */ 1054 static int 1055 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 1056 char *buf, int len) 1057 { 1058 char string[1024]; 1059 pid_t pid; 1060 int bytes = 0; 1061 u_int i; 1062 u_char ch; 1063 char *s; 1064 int *escape_pendingp, escape_char; 1065 struct escape_filter_ctx *efc; 1066 1067 if (c == NULL) { 1068 escape_pendingp = &escape_pending1; 1069 escape_char = escape_char1; 1070 } else { 1071 if (c->filter_ctx == NULL) 1072 return 0; 1073 efc = (struct escape_filter_ctx *)c->filter_ctx; 1074 escape_pendingp = &efc->escape_pending; 1075 escape_char = efc->escape_char; 1076 } 1077 1078 if (len <= 0) 1079 return (0); 1080 1081 for (i = 0; i < (u_int)len; i++) { 1082 /* Get one character at a time. */ 1083 ch = buf[i]; 1084 1085 if (*escape_pendingp) { 1086 /* We have previously seen an escape character. */ 1087 /* Clear the flag now. */ 1088 *escape_pendingp = 0; 1089 1090 /* Process the escaped character. */ 1091 switch (ch) { 1092 case '.': 1093 /* Terminate the connection. */ 1094 snprintf(string, sizeof string, "%c.\r\n", 1095 escape_char); 1096 buffer_append(berr, string, strlen(string)); 1097 1098 if (c && c->ctl_chan != -1) { 1099 chan_read_failed(c); 1100 chan_write_failed(c); 1101 if (c->detach_user) 1102 c->detach_user(c->self, NULL); 1103 c->type = SSH_CHANNEL_ABANDONED; 1104 buffer_clear(&c->input); 1105 chan_ibuf_empty(c); 1106 return 0; 1107 } else 1108 quit_pending = 1; 1109 return -1; 1110 1111 case 'Z' - 64: 1112 /* XXX support this for mux clients */ 1113 if (c && c->ctl_chan != -1) { 1114 char b[16]; 1115 noescape: 1116 if (ch == 'Z' - 64) 1117 snprintf(b, sizeof b, "^Z"); 1118 else 1119 snprintf(b, sizeof b, "%c", ch); 1120 snprintf(string, sizeof string, 1121 "%c%s escape not available to " 1122 "multiplexed sessions\r\n", 1123 escape_char, b); 1124 buffer_append(berr, string, 1125 strlen(string)); 1126 continue; 1127 } 1128 /* Suspend the program. Inform the user */ 1129 snprintf(string, sizeof string, 1130 "%c^Z [suspend ssh]\r\n", escape_char); 1131 buffer_append(berr, string, strlen(string)); 1132 1133 /* Restore terminal modes and suspend. */ 1134 client_suspend_self(bin, bout, berr); 1135 1136 /* We have been continued. */ 1137 continue; 1138 1139 case 'B': 1140 if (compat20) { 1141 snprintf(string, sizeof string, 1142 "%cB\r\n", escape_char); 1143 buffer_append(berr, string, 1144 strlen(string)); 1145 channel_request_start(c->self, 1146 "break", 0); 1147 packet_put_int(1000); 1148 packet_send(); 1149 } 1150 continue; 1151 1152 case 'R': 1153 if (compat20) { 1154 if (datafellows & SSH_BUG_NOREKEY) 1155 logit("Server does not " 1156 "support re-keying"); 1157 else 1158 need_rekeying = 1; 1159 } 1160 continue; 1161 1162 case 'V': 1163 /* FALLTHROUGH */ 1164 case 'v': 1165 if (c && c->ctl_chan != -1) 1166 goto noescape; 1167 if (!log_is_on_stderr()) { 1168 snprintf(string, sizeof string, 1169 "%c%c [Logging to syslog]\r\n", 1170 escape_char, ch); 1171 buffer_append(berr, string, 1172 strlen(string)); 1173 continue; 1174 } 1175 if (ch == 'V' && options.log_level > 1176 SYSLOG_LEVEL_QUIET) 1177 log_change_level(--options.log_level); 1178 if (ch == 'v' && options.log_level < 1179 SYSLOG_LEVEL_DEBUG3) 1180 log_change_level(++options.log_level); 1181 snprintf(string, sizeof string, 1182 "%c%c [LogLevel %s]\r\n", escape_char, ch, 1183 log_level_name(options.log_level)); 1184 buffer_append(berr, string, strlen(string)); 1185 continue; 1186 1187 case '&': 1188 if (c && c->ctl_chan != -1) 1189 goto noescape; 1190 /* 1191 * Detach the program (continue to serve 1192 * connections, but put in background and no 1193 * more new connections). 1194 */ 1195 /* Restore tty modes. */ 1196 leave_raw_mode( 1197 options.request_tty == REQUEST_TTY_FORCE); 1198 1199 /* Stop listening for new connections. */ 1200 channel_stop_listening(); 1201 1202 snprintf(string, sizeof string, 1203 "%c& [backgrounded]\n", escape_char); 1204 buffer_append(berr, string, strlen(string)); 1205 1206 /* Fork into background. */ 1207 pid = fork(); 1208 if (pid < 0) { 1209 error("fork: %.100s", strerror(errno)); 1210 continue; 1211 } 1212 if (pid != 0) { /* This is the parent. */ 1213 /* The parent just exits. */ 1214 exit(0); 1215 } 1216 /* The child continues serving connections. */ 1217 if (compat20) { 1218 buffer_append(bin, "\004", 1); 1219 /* fake EOF on stdin */ 1220 return -1; 1221 } else if (!stdin_eof) { 1222 /* 1223 * Sending SSH_CMSG_EOF alone does not 1224 * always appear to be enough. So we 1225 * try to send an EOF character first. 1226 */ 1227 packet_start(SSH_CMSG_STDIN_DATA); 1228 packet_put_string("\004", 1); 1229 packet_send(); 1230 /* Close stdin. */ 1231 stdin_eof = 1; 1232 if (buffer_len(bin) == 0) { 1233 packet_start(SSH_CMSG_EOF); 1234 packet_send(); 1235 } 1236 } 1237 continue; 1238 1239 case '?': 1240 print_escape_help(berr, escape_char, compat20, 1241 (c && c->ctl_chan != -1), 1242 log_is_on_stderr()); 1243 continue; 1244 1245 case '#': 1246 snprintf(string, sizeof string, "%c#\r\n", 1247 escape_char); 1248 buffer_append(berr, string, strlen(string)); 1249 s = channel_open_message(); 1250 buffer_append(berr, s, strlen(s)); 1251 free(s); 1252 continue; 1253 1254 case 'C': 1255 if (c && c->ctl_chan != -1) 1256 goto noescape; 1257 process_cmdline(); 1258 continue; 1259 1260 default: 1261 if (ch != escape_char) { 1262 buffer_put_char(bin, escape_char); 1263 bytes++; 1264 } 1265 /* Escaped characters fall through here */ 1266 break; 1267 } 1268 } else { 1269 /* 1270 * The previous character was not an escape char. 1271 * Check if this is an escape. 1272 */ 1273 if (last_was_cr && ch == escape_char) { 1274 /* 1275 * It is. Set the flag and continue to 1276 * next character. 1277 */ 1278 *escape_pendingp = 1; 1279 continue; 1280 } 1281 } 1282 1283 /* 1284 * Normal character. Record whether it was a newline, 1285 * and append it to the buffer. 1286 */ 1287 last_was_cr = (ch == '\r' || ch == '\n'); 1288 buffer_put_char(bin, ch); 1289 bytes++; 1290 } 1291 return bytes; 1292 } 1293 1294 static void 1295 client_process_input(fd_set *readset) 1296 { 1297 int len; 1298 char buf[SSH_IOBUFSZ]; 1299 1300 /* Read input from stdin. */ 1301 if (FD_ISSET(fileno(stdin), readset)) { 1302 /* Read as much as possible. */ 1303 len = read(fileno(stdin), buf, sizeof(buf)); 1304 if (len < 0 && 1305 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1306 return; /* we'll try again later */ 1307 if (len <= 0) { 1308 /* 1309 * Received EOF or error. They are treated 1310 * similarly, except that an error message is printed 1311 * if it was an error condition. 1312 */ 1313 if (len < 0) { 1314 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1315 strerror(errno)); 1316 buffer_append(&stderr_buffer, buf, strlen(buf)); 1317 } 1318 /* Mark that we have seen EOF. */ 1319 stdin_eof = 1; 1320 /* 1321 * Send an EOF message to the server unless there is 1322 * data in the buffer. If there is data in the 1323 * buffer, no message will be sent now. Code 1324 * elsewhere will send the EOF when the buffer 1325 * becomes empty if stdin_eof is set. 1326 */ 1327 if (buffer_len(&stdin_buffer) == 0) { 1328 packet_start(SSH_CMSG_EOF); 1329 packet_send(); 1330 } 1331 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1332 /* 1333 * Normal successful read, and no escape character. 1334 * Just append the data to buffer. 1335 */ 1336 buffer_append(&stdin_buffer, buf, len); 1337 } else { 1338 /* 1339 * Normal, successful read. But we have an escape 1340 * character and have to process the characters one 1341 * by one. 1342 */ 1343 if (process_escapes(NULL, &stdin_buffer, 1344 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1345 return; 1346 } 1347 } 1348 } 1349 1350 static void 1351 client_process_output(fd_set *writeset) 1352 { 1353 int len; 1354 char buf[100]; 1355 1356 /* Write buffered output to stdout. */ 1357 if (FD_ISSET(fileno(stdout), writeset)) { 1358 /* Write as much data as possible. */ 1359 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1360 buffer_len(&stdout_buffer)); 1361 if (len <= 0) { 1362 if (errno == EINTR || errno == EAGAIN || 1363 errno == EWOULDBLOCK) 1364 len = 0; 1365 else { 1366 /* 1367 * An error or EOF was encountered. Put an 1368 * error message to stderr buffer. 1369 */ 1370 snprintf(buf, sizeof buf, 1371 "write stdout: %.50s\r\n", strerror(errno)); 1372 buffer_append(&stderr_buffer, buf, strlen(buf)); 1373 quit_pending = 1; 1374 return; 1375 } 1376 } 1377 /* Consume printed data from the buffer. */ 1378 buffer_consume(&stdout_buffer, len); 1379 } 1380 /* Write buffered output to stderr. */ 1381 if (FD_ISSET(fileno(stderr), writeset)) { 1382 /* Write as much data as possible. */ 1383 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1384 buffer_len(&stderr_buffer)); 1385 if (len <= 0) { 1386 if (errno == EINTR || errno == EAGAIN || 1387 errno == EWOULDBLOCK) 1388 len = 0; 1389 else { 1390 /* 1391 * EOF or error, but can't even print 1392 * error message. 1393 */ 1394 quit_pending = 1; 1395 return; 1396 } 1397 } 1398 /* Consume printed characters from the buffer. */ 1399 buffer_consume(&stderr_buffer, len); 1400 } 1401 } 1402 1403 /* 1404 * Get packets from the connection input buffer, and process them as long as 1405 * there are packets available. 1406 * 1407 * Any unknown packets received during the actual 1408 * session cause the session to terminate. This is 1409 * intended to make debugging easier since no 1410 * confirmations are sent. Any compatible protocol 1411 * extensions must be negotiated during the 1412 * preparatory phase. 1413 */ 1414 1415 static void 1416 client_process_buffered_input_packets(void) 1417 { 1418 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, active_state); 1419 } 1420 1421 /* scan buf[] for '~' before sending data to the peer */ 1422 1423 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1424 void * 1425 client_new_escape_filter_ctx(int escape_char) 1426 { 1427 struct escape_filter_ctx *ret; 1428 1429 ret = xcalloc(1, sizeof(*ret)); 1430 ret->escape_pending = 0; 1431 ret->escape_char = escape_char; 1432 return (void *)ret; 1433 } 1434 1435 /* Free the escape filter context on channel free */ 1436 void 1437 client_filter_cleanup(int cid, void *ctx) 1438 { 1439 free(ctx); 1440 } 1441 1442 int 1443 client_simple_escape_filter(Channel *c, char *buf, int len) 1444 { 1445 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1446 return 0; 1447 1448 return process_escapes(c, &c->input, &c->output, &c->extended, 1449 buf, len); 1450 } 1451 1452 static void 1453 client_channel_closed(int id, void *arg) 1454 { 1455 channel_cancel_cleanup(id); 1456 session_closed = 1; 1457 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1458 } 1459 1460 /* 1461 * Implements the interactive session with the server. This is called after 1462 * the user has been authenticated, and a command has been started on the 1463 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1464 * used as an escape character for terminating or suspending the session. 1465 */ 1466 1467 int 1468 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1469 { 1470 fd_set *readset = NULL, *writeset = NULL; 1471 double start_time, total_time; 1472 int r, max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1473 u_int64_t ibytes, obytes; 1474 u_int nalloc = 0; 1475 char buf[100]; 1476 1477 debug("Entering interactive session."); 1478 1479 start_time = get_current_time(); 1480 1481 /* Initialize variables. */ 1482 escape_pending1 = 0; 1483 last_was_cr = 1; 1484 exit_status = -1; 1485 stdin_eof = 0; 1486 buffer_high = 64 * 1024; 1487 connection_in = packet_get_connection_in(); 1488 connection_out = packet_get_connection_out(); 1489 max_fd = MAX(connection_in, connection_out); 1490 1491 if (!compat20) { 1492 /* enable nonblocking unless tty */ 1493 if (!isatty(fileno(stdin))) 1494 set_nonblock(fileno(stdin)); 1495 if (!isatty(fileno(stdout))) 1496 set_nonblock(fileno(stdout)); 1497 if (!isatty(fileno(stderr))) 1498 set_nonblock(fileno(stderr)); 1499 max_fd = MAX(max_fd, fileno(stdin)); 1500 max_fd = MAX(max_fd, fileno(stdout)); 1501 max_fd = MAX(max_fd, fileno(stderr)); 1502 } 1503 quit_pending = 0; 1504 escape_char1 = escape_char_arg; 1505 1506 /* Initialize buffers. */ 1507 buffer_init(&stdin_buffer); 1508 buffer_init(&stdout_buffer); 1509 buffer_init(&stderr_buffer); 1510 1511 client_init_dispatch(); 1512 1513 /* 1514 * Set signal handlers, (e.g. to restore non-blocking mode) 1515 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1516 */ 1517 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1518 signal(SIGHUP, signal_handler); 1519 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1520 signal(SIGINT, signal_handler); 1521 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1522 signal(SIGQUIT, signal_handler); 1523 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1524 signal(SIGTERM, signal_handler); 1525 signal(SIGWINCH, window_change_handler); 1526 1527 if (have_pty) 1528 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1529 1530 if (compat20) { 1531 session_ident = ssh2_chan_id; 1532 if (session_ident != -1) { 1533 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1534 channel_register_filter(session_ident, 1535 client_simple_escape_filter, NULL, 1536 client_filter_cleanup, 1537 client_new_escape_filter_ctx( 1538 escape_char_arg)); 1539 } 1540 channel_register_cleanup(session_ident, 1541 client_channel_closed, 0); 1542 } 1543 } else { 1544 /* Check if we should immediately send eof on stdin. */ 1545 client_check_initial_eof_on_stdin(); 1546 } 1547 1548 /* Main loop of the client for the interactive session mode. */ 1549 while (!quit_pending) { 1550 1551 /* Process buffered packets sent by the server. */ 1552 client_process_buffered_input_packets(); 1553 1554 if (compat20 && session_closed && !channel_still_open()) 1555 break; 1556 1557 rekeying = (active_state->kex != NULL && !active_state->kex->done); 1558 1559 if (rekeying) { 1560 debug("rekeying in progress"); 1561 } else { 1562 /* 1563 * Make packets of buffered stdin data, and buffer 1564 * them for sending to the server. 1565 */ 1566 if (!compat20) 1567 client_make_packets_from_stdin_data(); 1568 1569 /* 1570 * Make packets from buffered channel data, and 1571 * enqueue them for sending to the server. 1572 */ 1573 if (packet_not_very_much_data_to_write()) 1574 channel_output_poll(); 1575 1576 /* 1577 * Check if the window size has changed, and buffer a 1578 * message about it to the server if so. 1579 */ 1580 client_check_window_change(); 1581 1582 if (quit_pending) 1583 break; 1584 } 1585 /* 1586 * Wait until we have something to do (something becomes 1587 * available on one of the descriptors). 1588 */ 1589 max_fd2 = max_fd; 1590 client_wait_until_can_do_something(&readset, &writeset, 1591 &max_fd2, &nalloc, rekeying); 1592 1593 if (quit_pending) 1594 break; 1595 1596 /* Do channel operations unless rekeying in progress. */ 1597 if (!rekeying) { 1598 channel_after_select(readset, writeset); 1599 if (need_rekeying || packet_need_rekeying()) { 1600 debug("need rekeying"); 1601 active_state->kex->done = 0; 1602 if ((r = kex_send_kexinit(active_state)) != 0) 1603 fatal("%s: kex_send_kexinit: %s", 1604 __func__, ssh_err(r)); 1605 need_rekeying = 0; 1606 } 1607 } 1608 1609 /* Buffer input from the connection. */ 1610 client_process_net_input(readset); 1611 1612 if (quit_pending) 1613 break; 1614 1615 if (!compat20) { 1616 /* Buffer data from stdin */ 1617 client_process_input(readset); 1618 /* 1619 * Process output to stdout and stderr. Output to 1620 * the connection is processed elsewhere (above). 1621 */ 1622 client_process_output(writeset); 1623 } 1624 1625 if (session_resumed) { 1626 connection_in = packet_get_connection_in(); 1627 connection_out = packet_get_connection_out(); 1628 max_fd = MAX(max_fd, connection_out); 1629 max_fd = MAX(max_fd, connection_in); 1630 session_resumed = 0; 1631 } 1632 1633 /* 1634 * Send as much buffered packet data as possible to the 1635 * sender. 1636 */ 1637 if (FD_ISSET(connection_out, writeset)) 1638 packet_write_poll(); 1639 1640 /* 1641 * If we are a backgrounded control master, and the 1642 * timeout has expired without any active client 1643 * connections, then quit. 1644 */ 1645 if (control_persist_exit_time > 0) { 1646 if (monotime() >= control_persist_exit_time) { 1647 debug("ControlPersist timeout expired"); 1648 break; 1649 } 1650 } 1651 } 1652 free(readset); 1653 free(writeset); 1654 1655 /* Terminate the session. */ 1656 1657 /* Stop watching for window change. */ 1658 signal(SIGWINCH, SIG_DFL); 1659 1660 if (compat20) { 1661 packet_start(SSH2_MSG_DISCONNECT); 1662 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1663 packet_put_cstring("disconnected by user"); 1664 packet_put_cstring(""); /* language tag */ 1665 packet_send(); 1666 packet_write_wait(); 1667 } 1668 1669 channel_free_all(); 1670 1671 if (have_pty) 1672 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1673 1674 /* restore blocking io */ 1675 if (!isatty(fileno(stdin))) 1676 unset_nonblock(fileno(stdin)); 1677 if (!isatty(fileno(stdout))) 1678 unset_nonblock(fileno(stdout)); 1679 if (!isatty(fileno(stderr))) 1680 unset_nonblock(fileno(stderr)); 1681 1682 /* 1683 * If there was no shell or command requested, there will be no remote 1684 * exit status to be returned. In that case, clear error code if the 1685 * connection was deliberately terminated at this end. 1686 */ 1687 if (no_shell_flag && received_signal == SIGTERM) { 1688 received_signal = 0; 1689 exit_status = 0; 1690 } 1691 1692 if (received_signal) 1693 fatal("Killed by signal %d.", (int) received_signal); 1694 1695 /* 1696 * In interactive mode (with pseudo tty) display a message indicating 1697 * that the connection has been closed. 1698 */ 1699 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1700 snprintf(buf, sizeof buf, 1701 "Connection to %.64s closed.\r\n", host); 1702 buffer_append(&stderr_buffer, buf, strlen(buf)); 1703 } 1704 1705 /* Output any buffered data for stdout. */ 1706 if (buffer_len(&stdout_buffer) > 0) { 1707 len = atomicio(vwrite, fileno(stdout), 1708 buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer)); 1709 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer)) 1710 error("Write failed flushing stdout buffer."); 1711 else 1712 buffer_consume(&stdout_buffer, len); 1713 } 1714 1715 /* Output any buffered data for stderr. */ 1716 if (buffer_len(&stderr_buffer) > 0) { 1717 len = atomicio(vwrite, fileno(stderr), 1718 buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer)); 1719 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer)) 1720 error("Write failed flushing stderr buffer."); 1721 else 1722 buffer_consume(&stderr_buffer, len); 1723 } 1724 1725 /* Clear and free any buffers. */ 1726 memset(buf, 0, sizeof(buf)); 1727 buffer_free(&stdin_buffer); 1728 buffer_free(&stdout_buffer); 1729 buffer_free(&stderr_buffer); 1730 1731 /* Report bytes transferred, and transfer rates. */ 1732 total_time = get_current_time() - start_time; 1733 packet_get_bytes(&ibytes, &obytes); 1734 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1735 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1736 if (total_time > 0) 1737 verbose("Bytes per second: sent %.1f, received %.1f", 1738 obytes / total_time, ibytes / total_time); 1739 /* Return the exit status of the program. */ 1740 debug("Exit status %d", exit_status); 1741 return exit_status; 1742 } 1743 1744 /*********/ 1745 1746 static int 1747 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1748 { 1749 u_int data_len; 1750 char *data = packet_get_string(&data_len); 1751 packet_check_eom(); 1752 buffer_append(&stdout_buffer, data, data_len); 1753 explicit_bzero(data, data_len); 1754 free(data); 1755 return 0; 1756 } 1757 static int 1758 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1759 { 1760 u_int data_len; 1761 char *data = packet_get_string(&data_len); 1762 packet_check_eom(); 1763 buffer_append(&stderr_buffer, data, data_len); 1764 explicit_bzero(data, data_len); 1765 free(data); 1766 return 0; 1767 } 1768 static int 1769 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1770 { 1771 exit_status = packet_get_int(); 1772 packet_check_eom(); 1773 /* Acknowledge the exit. */ 1774 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1775 packet_send(); 1776 /* 1777 * Must wait for packet to be sent since we are 1778 * exiting the loop. 1779 */ 1780 packet_write_wait(); 1781 /* Flag that we want to exit. */ 1782 quit_pending = 1; 1783 return 0; 1784 } 1785 1786 static int 1787 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1788 { 1789 Channel *c = NULL; 1790 int r, remote_id, sock; 1791 1792 /* Read the remote channel number from the message. */ 1793 remote_id = packet_get_int(); 1794 packet_check_eom(); 1795 1796 /* 1797 * Get a connection to the local authentication agent (this may again 1798 * get forwarded). 1799 */ 1800 if ((r = ssh_get_authentication_socket(&sock)) != 0 && 1801 r != SSH_ERR_AGENT_NOT_PRESENT) 1802 debug("%s: ssh_get_authentication_socket: %s", 1803 __func__, ssh_err(r)); 1804 1805 1806 /* 1807 * If we could not connect the agent, send an error message back to 1808 * the server. This should never happen unless the agent dies, 1809 * because authentication forwarding is only enabled if we have an 1810 * agent. 1811 */ 1812 if (sock >= 0) { 1813 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1814 -1, 0, 0, 0, "authentication agent connection", 1); 1815 c->remote_id = remote_id; 1816 c->force_drain = 1; 1817 } 1818 if (c == NULL) { 1819 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1820 packet_put_int(remote_id); 1821 } else { 1822 /* Send a confirmation to the remote host. */ 1823 debug("Forwarding authentication connection."); 1824 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1825 packet_put_int(remote_id); 1826 packet_put_int(c->self); 1827 } 1828 packet_send(); 1829 return 0; 1830 } 1831 1832 static Channel * 1833 client_request_forwarded_tcpip(const char *request_type, int rchan) 1834 { 1835 Channel *c = NULL; 1836 char *listen_address, *originator_address; 1837 u_short listen_port, originator_port; 1838 1839 /* Get rest of the packet */ 1840 listen_address = packet_get_string(NULL); 1841 listen_port = packet_get_int(); 1842 originator_address = packet_get_string(NULL); 1843 originator_port = packet_get_int(); 1844 packet_check_eom(); 1845 1846 debug("%s: listen %s port %d, originator %s port %d", __func__, 1847 listen_address, listen_port, originator_address, originator_port); 1848 1849 c = channel_connect_by_listen_address(listen_address, listen_port, 1850 "forwarded-tcpip", originator_address); 1851 1852 free(originator_address); 1853 free(listen_address); 1854 return c; 1855 } 1856 1857 static Channel * 1858 client_request_forwarded_streamlocal(const char *request_type, int rchan) 1859 { 1860 Channel *c = NULL; 1861 char *listen_path; 1862 1863 /* Get the remote path. */ 1864 listen_path = packet_get_string(NULL); 1865 /* XXX: Skip reserved field for now. */ 1866 if (packet_get_string_ptr(NULL) == NULL) 1867 fatal("%s: packet_get_string_ptr failed", __func__); 1868 packet_check_eom(); 1869 1870 debug("%s: %s", __func__, listen_path); 1871 1872 c = channel_connect_by_listen_path(listen_path, 1873 "forwarded-streamlocal (at) openssh.com", "forwarded-streamlocal"); 1874 free(listen_path); 1875 return c; 1876 } 1877 1878 static Channel * 1879 client_request_x11(const char *request_type, int rchan) 1880 { 1881 Channel *c = NULL; 1882 char *originator; 1883 u_short originator_port; 1884 int sock; 1885 1886 if (!options.forward_x11) { 1887 error("Warning: ssh server tried X11 forwarding."); 1888 error("Warning: this is probably a break-in attempt by a " 1889 "malicious server."); 1890 return NULL; 1891 } 1892 if (x11_refuse_time != 0 && monotime() >= x11_refuse_time) { 1893 verbose("Rejected X11 connection after ForwardX11Timeout " 1894 "expired"); 1895 return NULL; 1896 } 1897 originator = packet_get_string(NULL); 1898 if (datafellows & SSH_BUG_X11FWD) { 1899 debug2("buggy server: x11 request w/o originator_port"); 1900 originator_port = 0; 1901 } else { 1902 originator_port = packet_get_int(); 1903 } 1904 packet_check_eom(); 1905 /* XXX check permission */ 1906 debug("client_request_x11: request from %s %d", originator, 1907 originator_port); 1908 free(originator); 1909 sock = x11_connect_display(); 1910 if (sock < 0) 1911 return NULL; 1912 c = channel_new("x11", 1913 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1914 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1915 c->force_drain = 1; 1916 return c; 1917 } 1918 1919 static Channel * 1920 client_request_agent(const char *request_type, int rchan) 1921 { 1922 Channel *c = NULL; 1923 int r, sock; 1924 1925 if (!options.forward_agent) { 1926 error("Warning: ssh server tried agent forwarding."); 1927 error("Warning: this is probably a break-in attempt by a " 1928 "malicious server."); 1929 return NULL; 1930 } 1931 if ((r = ssh_get_authentication_socket(&sock)) != 0) { 1932 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1933 debug("%s: ssh_get_authentication_socket: %s", 1934 __func__, ssh_err(r)); 1935 return NULL; 1936 } 1937 c = channel_new("authentication agent connection", 1938 SSH_CHANNEL_OPEN, sock, sock, -1, 1939 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1940 "authentication agent connection", 1); 1941 c->force_drain = 1; 1942 return c; 1943 } 1944 1945 int 1946 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1947 { 1948 Channel *c; 1949 int fd; 1950 1951 if (tun_mode == SSH_TUNMODE_NO) 1952 return 0; 1953 1954 if (!compat20) { 1955 error("Tunnel forwarding is not supported for protocol 1"); 1956 return -1; 1957 } 1958 1959 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1960 1961 /* Open local tunnel device */ 1962 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1963 error("Tunnel device open failed."); 1964 return -1; 1965 } 1966 1967 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1968 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1969 c->datagram = 1; 1970 1971 #if defined(SSH_TUN_FILTER) 1972 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1973 channel_register_filter(c->self, sys_tun_infilter, 1974 sys_tun_outfilter, NULL, NULL); 1975 #endif 1976 1977 packet_start(SSH2_MSG_CHANNEL_OPEN); 1978 packet_put_cstring("tun (at) openssh.com"); 1979 packet_put_int(c->self); 1980 packet_put_int(c->local_window_max); 1981 packet_put_int(c->local_maxpacket); 1982 packet_put_int(tun_mode); 1983 packet_put_int(remote_tun); 1984 packet_send(); 1985 1986 return 0; 1987 } 1988 1989 /* XXXX move to generic input handler */ 1990 static int 1991 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1992 { 1993 Channel *c = NULL; 1994 char *ctype; 1995 int rchan; 1996 u_int rmaxpack, rwindow, len; 1997 1998 ctype = packet_get_string(&len); 1999 rchan = packet_get_int(); 2000 rwindow = packet_get_int(); 2001 rmaxpack = packet_get_int(); 2002 2003 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 2004 ctype, rchan, rwindow, rmaxpack); 2005 2006 if (strcmp(ctype, "forwarded-tcpip") == 0) { 2007 c = client_request_forwarded_tcpip(ctype, rchan); 2008 } else if (strcmp(ctype, "forwarded-streamlocal (at) openssh.com") == 0) { 2009 c = client_request_forwarded_streamlocal(ctype, rchan); 2010 } else if (strcmp(ctype, "x11") == 0) { 2011 c = client_request_x11(ctype, rchan); 2012 } else if (strcmp(ctype, "auth-agent (at) openssh.com") == 0) { 2013 c = client_request_agent(ctype, rchan); 2014 } 2015 /* XXX duplicate : */ 2016 if (c != NULL) { 2017 debug("confirm %s", ctype); 2018 c->remote_id = rchan; 2019 c->remote_window = rwindow; 2020 c->remote_maxpacket = rmaxpack; 2021 if (c->type != SSH_CHANNEL_CONNECTING) { 2022 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 2023 packet_put_int(c->remote_id); 2024 packet_put_int(c->self); 2025 packet_put_int(c->local_window); 2026 packet_put_int(c->local_maxpacket); 2027 packet_send(); 2028 } 2029 } else { 2030 debug("failure %s", ctype); 2031 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 2032 packet_put_int(rchan); 2033 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 2034 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 2035 packet_put_cstring("open failed"); 2036 packet_put_cstring(""); 2037 } 2038 packet_send(); 2039 } 2040 free(ctype); 2041 return 0; 2042 } 2043 2044 static int 2045 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 2046 { 2047 Channel *c = NULL; 2048 int exitval, id, reply, success = 0; 2049 char *rtype; 2050 2051 id = packet_get_int(); 2052 rtype = packet_get_string(NULL); 2053 reply = packet_get_char(); 2054 2055 debug("client_input_channel_req: channel %d rtype %s reply %d", 2056 id, rtype, reply); 2057 2058 if (id == -1) { 2059 error("client_input_channel_req: request for channel -1"); 2060 } else if ((c = channel_lookup(id)) == NULL) { 2061 error("client_input_channel_req: channel %d: " 2062 "unknown channel", id); 2063 } else if (strcmp(rtype, "eow (at) openssh.com") == 0) { 2064 packet_check_eom(); 2065 chan_rcvd_eow(c); 2066 } else if (strcmp(rtype, "exit-status") == 0) { 2067 exitval = packet_get_int(); 2068 if (c->ctl_chan != -1) { 2069 mux_exit_message(c, exitval); 2070 success = 1; 2071 } else if (id == session_ident) { 2072 /* Record exit value of local session */ 2073 success = 1; 2074 exit_status = exitval; 2075 } else { 2076 /* Probably for a mux channel that has already closed */ 2077 debug("%s: no sink for exit-status on channel %d", 2078 __func__, id); 2079 } 2080 packet_check_eom(); 2081 } 2082 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { 2083 packet_start(success ? 2084 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 2085 packet_put_int(c->remote_id); 2086 packet_send(); 2087 } 2088 free(rtype); 2089 return 0; 2090 } 2091 2092 struct hostkeys_update_ctx { 2093 /* The hostname and (optionally) IP address string for the server */ 2094 char *host_str, *ip_str; 2095 2096 /* 2097 * Keys received from the server and a flag for each indicating 2098 * whether they already exist in known_hosts. 2099 * keys_seen is filled in by hostkeys_find() and later (for new 2100 * keys) by client_global_hostkeys_private_confirm(). 2101 */ 2102 struct sshkey **keys; 2103 int *keys_seen; 2104 size_t nkeys; 2105 2106 size_t nnew; 2107 2108 /* 2109 * Keys that are in known_hosts, but were not present in the update 2110 * from the server (i.e. scheduled to be deleted). 2111 * Filled in by hostkeys_find(). 2112 */ 2113 struct sshkey **old_keys; 2114 size_t nold; 2115 }; 2116 2117 static void 2118 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx) 2119 { 2120 size_t i; 2121 2122 if (ctx == NULL) 2123 return; 2124 for (i = 0; i < ctx->nkeys; i++) 2125 sshkey_free(ctx->keys[i]); 2126 free(ctx->keys); 2127 free(ctx->keys_seen); 2128 for (i = 0; i < ctx->nold; i++) 2129 sshkey_free(ctx->old_keys[i]); 2130 free(ctx->old_keys); 2131 free(ctx->host_str); 2132 free(ctx->ip_str); 2133 free(ctx); 2134 } 2135 2136 static int 2137 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx) 2138 { 2139 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2140 size_t i; 2141 struct sshkey **tmp; 2142 2143 if (l->status != HKF_STATUS_MATCHED || l->key == NULL || 2144 l->key->type == KEY_RSA1) 2145 return 0; 2146 2147 /* Mark off keys we've already seen for this host */ 2148 for (i = 0; i < ctx->nkeys; i++) { 2149 if (sshkey_equal(l->key, ctx->keys[i])) { 2150 debug3("%s: found %s key at %s:%ld", __func__, 2151 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum); 2152 ctx->keys_seen[i] = 1; 2153 return 0; 2154 } 2155 } 2156 /* This line contained a key that not offered by the server */ 2157 debug3("%s: deprecated %s key at %s:%ld", __func__, 2158 sshkey_ssh_name(l->key), l->path, l->linenum); 2159 if ((tmp = reallocarray(ctx->old_keys, ctx->nold + 1, 2160 sizeof(*ctx->old_keys))) == NULL) 2161 fatal("%s: reallocarray failed nold = %zu", 2162 __func__, ctx->nold); 2163 ctx->old_keys = tmp; 2164 ctx->old_keys[ctx->nold++] = l->key; 2165 l->key = NULL; 2166 2167 return 0; 2168 } 2169 2170 static void 2171 update_known_hosts(struct hostkeys_update_ctx *ctx) 2172 { 2173 int r, was_raw = 0; 2174 int loglevel = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK ? 2175 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE; 2176 char *fp, *response; 2177 size_t i; 2178 2179 for (i = 0; i < ctx->nkeys; i++) { 2180 if (ctx->keys_seen[i] != 2) 2181 continue; 2182 if ((fp = sshkey_fingerprint(ctx->keys[i], 2183 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2184 fatal("%s: sshkey_fingerprint failed", __func__); 2185 do_log2(loglevel, "Learned new hostkey: %s %s", 2186 sshkey_type(ctx->keys[i]), fp); 2187 free(fp); 2188 } 2189 for (i = 0; i < ctx->nold; i++) { 2190 if ((fp = sshkey_fingerprint(ctx->old_keys[i], 2191 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2192 fatal("%s: sshkey_fingerprint failed", __func__); 2193 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s", 2194 sshkey_type(ctx->old_keys[i]), fp); 2195 free(fp); 2196 } 2197 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 2198 if (get_saved_tio() != NULL) { 2199 leave_raw_mode(1); 2200 was_raw = 1; 2201 } 2202 response = NULL; 2203 for (i = 0; !quit_pending && i < 3; i++) { 2204 free(response); 2205 response = read_passphrase("Accept updated hostkeys? " 2206 "(yes/no): ", RP_ECHO); 2207 if (strcasecmp(response, "yes") == 0) 2208 break; 2209 else if (quit_pending || response == NULL || 2210 strcasecmp(response, "no") == 0) { 2211 options.update_hostkeys = 0; 2212 break; 2213 } else { 2214 do_log2(loglevel, "Please enter " 2215 "\"yes\" or \"no\""); 2216 } 2217 } 2218 if (quit_pending || i >= 3 || response == NULL) 2219 options.update_hostkeys = 0; 2220 free(response); 2221 if (was_raw) 2222 enter_raw_mode(1); 2223 } 2224 2225 /* 2226 * Now that all the keys are verified, we can go ahead and replace 2227 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't 2228 * cancel the operation). 2229 */ 2230 if (options.update_hostkeys != 0 && 2231 (r = hostfile_replace_entries(options.user_hostfiles[0], 2232 ctx->host_str, ctx->ip_str, ctx->keys, ctx->nkeys, 2233 options.hash_known_hosts, 0, 2234 options.fingerprint_hash)) != 0) 2235 error("%s: hostfile_replace_entries failed: %s", 2236 __func__, ssh_err(r)); 2237 } 2238 2239 static void 2240 client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx) 2241 { 2242 struct ssh *ssh = active_state; /* XXX */ 2243 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2244 size_t i, ndone; 2245 struct sshbuf *signdata; 2246 int r; 2247 const u_char *sig; 2248 size_t siglen; 2249 2250 if (ctx->nnew == 0) 2251 fatal("%s: ctx->nnew == 0", __func__); /* sanity */ 2252 if (type != SSH2_MSG_REQUEST_SUCCESS) { 2253 error("Server failed to confirm ownership of " 2254 "private host keys"); 2255 hostkeys_update_ctx_free(ctx); 2256 return; 2257 } 2258 if ((signdata = sshbuf_new()) == NULL) 2259 fatal("%s: sshbuf_new failed", __func__); 2260 /* Don't want to accidentally accept an unbound signature */ 2261 if (ssh->kex->session_id_len == 0) 2262 fatal("%s: ssh->kex->session_id_len == 0", __func__); 2263 /* 2264 * Expect a signature for each of the ctx->nnew private keys we 2265 * haven't seen before. They will be in the same order as the 2266 * ctx->keys where the corresponding ctx->keys_seen[i] == 0. 2267 */ 2268 for (ndone = i = 0; i < ctx->nkeys; i++) { 2269 if (ctx->keys_seen[i]) 2270 continue; 2271 /* Prepare data to be signed: session ID, unique string, key */ 2272 sshbuf_reset(signdata); 2273 if ( (r = sshbuf_put_cstring(signdata, 2274 "hostkeys-prove-00 (at) openssh.com")) != 0 || 2275 (r = sshbuf_put_string(signdata, ssh->kex->session_id, 2276 ssh->kex->session_id_len)) != 0 || 2277 (r = sshkey_puts(ctx->keys[i], signdata)) != 0) 2278 fatal("%s: failed to prepare signature: %s", 2279 __func__, ssh_err(r)); 2280 /* Extract and verify signature */ 2281 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) { 2282 error("%s: couldn't parse message: %s", 2283 __func__, ssh_err(r)); 2284 goto out; 2285 } 2286 if ((r = sshkey_verify(ctx->keys[i], sig, siglen, 2287 sshbuf_ptr(signdata), sshbuf_len(signdata), 0)) != 0) { 2288 error("%s: server gave bad signature for %s key %zu", 2289 __func__, sshkey_type(ctx->keys[i]), i); 2290 goto out; 2291 } 2292 /* Key is good. Mark it as 'seen' */ 2293 ctx->keys_seen[i] = 2; 2294 ndone++; 2295 } 2296 if (ndone != ctx->nnew) 2297 fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__, 2298 ndone, ctx->nnew); /* Shouldn't happen */ 2299 ssh_packet_check_eom(ssh); 2300 2301 /* Make the edits to known_hosts */ 2302 update_known_hosts(ctx); 2303 out: 2304 hostkeys_update_ctx_free(ctx); 2305 } 2306 2307 /* 2308 * Handle hostkeys-00 (at) openssh.com global request to inform the client of all 2309 * the server's hostkeys. The keys are checked against the user's 2310 * HostkeyAlgorithms preference before they are accepted. 2311 */ 2312 static int 2313 client_input_hostkeys(void) 2314 { 2315 struct ssh *ssh = active_state; /* XXX */ 2316 const u_char *blob = NULL; 2317 size_t i, len = 0; 2318 struct sshbuf *buf = NULL; 2319 struct sshkey *key = NULL, **tmp; 2320 int r; 2321 char *fp; 2322 static int hostkeys_seen = 0; /* XXX use struct ssh */ 2323 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */ 2324 struct hostkeys_update_ctx *ctx = NULL; 2325 2326 if (hostkeys_seen) 2327 fatal("%s: server already sent hostkeys", __func__); 2328 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK && 2329 options.batch_mode) 2330 return 1; /* won't ask in batchmode, so don't even try */ 2331 if (!options.update_hostkeys || options.num_user_hostfiles <= 0) 2332 return 1; 2333 2334 ctx = xcalloc(1, sizeof(*ctx)); 2335 while (ssh_packet_remaining(ssh) > 0) { 2336 sshkey_free(key); 2337 key = NULL; 2338 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) { 2339 error("%s: couldn't parse message: %s", 2340 __func__, ssh_err(r)); 2341 goto out; 2342 } 2343 if ((r = sshkey_from_blob(blob, len, &key)) != 0) { 2344 error("%s: parse key: %s", __func__, ssh_err(r)); 2345 goto out; 2346 } 2347 fp = sshkey_fingerprint(key, options.fingerprint_hash, 2348 SSH_FP_DEFAULT); 2349 debug3("%s: received %s key %s", __func__, 2350 sshkey_type(key), fp); 2351 free(fp); 2352 /* Check that the key is accepted in HostkeyAlgorithms */ 2353 if (options.hostkeyalgorithms != NULL && 2354 match_pattern_list(sshkey_ssh_name(key), 2355 options.hostkeyalgorithms, 2356 strlen(options.hostkeyalgorithms), 0) != 1) { 2357 debug3("%s: %s key not permitted by HostkeyAlgorithms", 2358 __func__, sshkey_ssh_name(key)); 2359 continue; 2360 } 2361 /* Skip certs */ 2362 if (sshkey_is_cert(key)) { 2363 debug3("%s: %s key is a certificate; skipping", 2364 __func__, sshkey_ssh_name(key)); 2365 continue; 2366 } 2367 /* Ensure keys are unique */ 2368 for (i = 0; i < ctx->nkeys; i++) { 2369 if (sshkey_equal(key, ctx->keys[i])) { 2370 error("%s: received duplicated %s host key", 2371 __func__, sshkey_ssh_name(key)); 2372 goto out; 2373 } 2374 } 2375 /* Key is good, record it */ 2376 if ((tmp = reallocarray(ctx->keys, ctx->nkeys + 1, 2377 sizeof(*ctx->keys))) == NULL) 2378 fatal("%s: reallocarray failed nkeys = %zu", 2379 __func__, ctx->nkeys); 2380 ctx->keys = tmp; 2381 ctx->keys[ctx->nkeys++] = key; 2382 key = NULL; 2383 } 2384 2385 if (ctx->nkeys == 0) { 2386 debug("%s: server sent no hostkeys", __func__); 2387 goto out; 2388 } 2389 2390 if ((ctx->keys_seen = calloc(ctx->nkeys, 2391 sizeof(*ctx->keys_seen))) == NULL) 2392 fatal("%s: calloc failed", __func__); 2393 2394 get_hostfile_hostname_ipaddr(host, 2395 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL, 2396 options.port, &ctx->host_str, 2397 options.check_host_ip ? &ctx->ip_str : NULL); 2398 2399 /* Find which keys we already know about. */ 2400 if ((r = hostkeys_foreach(options.user_hostfiles[0], hostkeys_find, 2401 ctx, ctx->host_str, ctx->ip_str, 2402 HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) { 2403 error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r)); 2404 goto out; 2405 } 2406 2407 /* Figure out if we have any new keys to add */ 2408 ctx->nnew = 0; 2409 for (i = 0; i < ctx->nkeys; i++) { 2410 if (!ctx->keys_seen[i]) 2411 ctx->nnew++; 2412 } 2413 2414 debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove", 2415 __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold); 2416 2417 if (ctx->nnew == 0 && ctx->nold != 0) { 2418 /* We have some keys to remove. Just do it. */ 2419 update_known_hosts(ctx); 2420 } else if (ctx->nnew != 0) { 2421 /* 2422 * We have received hitherto-unseen keys from the server. 2423 * Ask the server to confirm ownership of the private halves. 2424 */ 2425 debug3("%s: asking server to prove ownership for %zu keys", 2426 __func__, ctx->nnew); 2427 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2428 (r = sshpkt_put_cstring(ssh, 2429 "hostkeys-prove-00 (at) openssh.com")) != 0 || 2430 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */ 2431 fatal("%s: cannot prepare packet: %s", 2432 __func__, ssh_err(r)); 2433 if ((buf = sshbuf_new()) == NULL) 2434 fatal("%s: sshbuf_new", __func__); 2435 for (i = 0; i < ctx->nkeys; i++) { 2436 if (ctx->keys_seen[i]) 2437 continue; 2438 sshbuf_reset(buf); 2439 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0) 2440 fatal("%s: sshkey_putb: %s", 2441 __func__, ssh_err(r)); 2442 if ((r = sshpkt_put_stringb(ssh, buf)) != 0) 2443 fatal("%s: sshpkt_put_string: %s", 2444 __func__, ssh_err(r)); 2445 } 2446 if ((r = sshpkt_send(ssh)) != 0) 2447 fatal("%s: sshpkt_send: %s", __func__, ssh_err(r)); 2448 client_register_global_confirm( 2449 client_global_hostkeys_private_confirm, ctx); 2450 ctx = NULL; /* will be freed in callback */ 2451 } 2452 2453 /* Success */ 2454 out: 2455 hostkeys_update_ctx_free(ctx); 2456 sshkey_free(key); 2457 sshbuf_free(buf); 2458 /* 2459 * NB. Return success for all cases. The server doesn't need to know 2460 * what the client does with its hosts file. 2461 */ 2462 return 1; 2463 } 2464 2465 static int 2466 client_input_global_request(int type, u_int32_t seq, void *ctxt) 2467 { 2468 char *rtype; 2469 int want_reply; 2470 int success = 0; 2471 2472 rtype = packet_get_cstring(NULL); 2473 want_reply = packet_get_char(); 2474 debug("client_input_global_request: rtype %s want_reply %d", 2475 rtype, want_reply); 2476 if (strcmp(rtype, "hostkeys-00 (at) openssh.com") == 0) 2477 success = client_input_hostkeys(); 2478 if (want_reply) { 2479 packet_start(success ? 2480 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 2481 packet_send(); 2482 packet_write_wait(); 2483 } 2484 free(rtype); 2485 return 0; 2486 } 2487 2488 void 2489 client_session2_setup(int id, int want_tty, int want_subsystem, 2490 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 2491 { 2492 int len; 2493 Channel *c = NULL; 2494 2495 debug2("%s: id %d", __func__, id); 2496 2497 if ((c = channel_lookup(id)) == NULL) 2498 fatal("client_session2_setup: channel %d: unknown channel", id); 2499 2500 packet_set_interactive(want_tty, 2501 options.ip_qos_interactive, options.ip_qos_bulk); 2502 2503 if (want_tty) { 2504 struct winsize ws; 2505 2506 /* Store window size in the packet. */ 2507 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 2508 memset(&ws, 0, sizeof(ws)); 2509 2510 channel_request_start(id, "pty-req", 1); 2511 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); 2512 packet_put_cstring(term != NULL ? term : ""); 2513 packet_put_int((u_int)ws.ws_col); 2514 packet_put_int((u_int)ws.ws_row); 2515 packet_put_int((u_int)ws.ws_xpixel); 2516 packet_put_int((u_int)ws.ws_ypixel); 2517 if (tiop == NULL) 2518 tiop = get_saved_tio(); 2519 tty_make_modes(-1, tiop); 2520 packet_send(); 2521 /* XXX wait for reply */ 2522 c->client_tty = 1; 2523 } 2524 2525 /* Transfer any environment variables from client to server */ 2526 if (options.num_send_env != 0 && env != NULL) { 2527 int i, j, matched; 2528 char *name, *val; 2529 2530 debug("Sending environment."); 2531 for (i = 0; env[i] != NULL; i++) { 2532 /* Split */ 2533 name = xstrdup(env[i]); 2534 if ((val = strchr(name, '=')) == NULL) { 2535 free(name); 2536 continue; 2537 } 2538 *val++ = '\0'; 2539 2540 matched = 0; 2541 for (j = 0; j < options.num_send_env; j++) { 2542 if (match_pattern(name, options.send_env[j])) { 2543 matched = 1; 2544 break; 2545 } 2546 } 2547 if (!matched) { 2548 debug3("Ignored env %s", name); 2549 free(name); 2550 continue; 2551 } 2552 2553 debug("Sending env %s = %s", name, val); 2554 channel_request_start(id, "env", 0); 2555 packet_put_cstring(name); 2556 packet_put_cstring(val); 2557 packet_send(); 2558 free(name); 2559 } 2560 } 2561 2562 len = buffer_len(cmd); 2563 if (len > 0) { 2564 if (len > 900) 2565 len = 900; 2566 if (want_subsystem) { 2567 debug("Sending subsystem: %.*s", 2568 len, (u_char*)buffer_ptr(cmd)); 2569 channel_request_start(id, "subsystem", 1); 2570 client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); 2571 } else { 2572 debug("Sending command: %.*s", 2573 len, (u_char*)buffer_ptr(cmd)); 2574 channel_request_start(id, "exec", 1); 2575 client_expect_confirm(id, "exec", CONFIRM_CLOSE); 2576 } 2577 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 2578 packet_send(); 2579 } else { 2580 channel_request_start(id, "shell", 1); 2581 client_expect_confirm(id, "shell", CONFIRM_CLOSE); 2582 packet_send(); 2583 } 2584 } 2585 2586 static void 2587 client_init_dispatch_20(void) 2588 { 2589 dispatch_init(&dispatch_protocol_error); 2590 2591 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2592 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2593 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2594 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2595 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2596 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2597 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2598 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2599 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2600 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2601 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2602 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2603 2604 /* rekeying */ 2605 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2606 2607 /* global request reply messages */ 2608 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2609 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2610 } 2611 2612 static void 2613 client_init_dispatch_13(void) 2614 { 2615 dispatch_init(NULL); 2616 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2617 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2618 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2619 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2620 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2621 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2622 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2623 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2624 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2625 2626 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2627 &client_input_agent_open : &deny_input_open); 2628 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2629 &x11_input_open : &deny_input_open); 2630 } 2631 2632 static void 2633 client_init_dispatch_15(void) 2634 { 2635 client_init_dispatch_13(); 2636 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2637 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2638 } 2639 2640 static void 2641 client_init_dispatch(void) 2642 { 2643 if (compat20) 2644 client_init_dispatch_20(); 2645 else if (compat13) 2646 client_init_dispatch_13(); 2647 else 2648 client_init_dispatch_15(); 2649 } 2650 2651 void 2652 client_stop_mux(void) 2653 { 2654 if (options.control_path != NULL && muxserver_sock != -1) 2655 unlink(options.control_path); 2656 /* 2657 * If we are in persist mode, or don't have a shell, signal that we 2658 * should close when all active channels are closed. 2659 */ 2660 if (options.control_persist || no_shell_flag) { 2661 session_closed = 1; 2662 setproctitle("[stopped mux]"); 2663 } 2664 } 2665 2666 /* client specific fatal cleanup */ 2667 void 2668 cleanup_exit(int i) 2669 { 2670 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2671 leave_non_blocking(); 2672 if (options.control_path != NULL && muxserver_sock != -1) 2673 unlink(options.control_path); 2674 ssh_kill_proxy_command(); 2675 _exit(i); 2676 } 2677