1 /* $OpenBSD: clientloop.c,v 1.291 2017/03/10 05:01:13 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/types.h> 65 #include <sys/ioctl.h> 66 #ifdef HAVE_SYS_STAT_H 67 # include <sys/stat.h> 68 #endif 69 #ifdef HAVE_SYS_TIME_H 70 # include <sys/time.h> 71 #endif 72 #include <sys/socket.h> 73 74 #include <ctype.h> 75 #include <errno.h> 76 #ifdef HAVE_PATHS_H 77 #include <paths.h> 78 #endif 79 #include <signal.h> 80 #include <stdarg.h> 81 #include <stdio.h> 82 #include <stdlib.h> 83 #include <string.h> 84 #include <termios.h> 85 #include <pwd.h> 86 #include <unistd.h> 87 #include <limits.h> 88 89 #include "openbsd-compat/sys-queue.h" 90 #include "xmalloc.h" 91 #include "ssh.h" 92 #include "ssh1.h" 93 #include "ssh2.h" 94 #include "packet.h" 95 #include "buffer.h" 96 #include "compat.h" 97 #include "channels.h" 98 #include "dispatch.h" 99 #include "key.h" 100 #include "cipher.h" 101 #include "kex.h" 102 #include "myproposal.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 "ssherr.h" 114 #include "hostfile.h" 115 116 /* import options */ 117 extern Options options; 118 119 /* Flag indicating that stdin should be redirected from /dev/null. */ 120 extern int stdin_null_flag; 121 122 /* Flag indicating that no shell has been requested */ 123 extern int no_shell_flag; 124 125 /* Flag indicating that ssh should daemonise after authentication is complete */ 126 extern int fork_after_authentication_flag; 127 128 /* Control socket */ 129 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 130 131 /* 132 * Name of the host we are connecting to. This is the name given on the 133 * command line, or the HostName specified for the user-supplied name in a 134 * configuration file. 135 */ 136 extern char *host; 137 138 /* 139 * Flag to indicate that we have received a window change signal which has 140 * not yet been processed. This will cause a message indicating the new 141 * window size to be sent to the server a little later. This is volatile 142 * because this is updated in a signal handler. 143 */ 144 static volatile sig_atomic_t received_window_change_signal = 0; 145 static volatile sig_atomic_t received_signal = 0; 146 147 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 148 static int in_non_blocking_mode = 0; 149 150 /* Time when backgrounded control master using ControlPersist should exit */ 151 static time_t control_persist_exit_time = 0; 152 153 /* Common data for the client loop code. */ 154 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 155 static int escape_char1; /* Escape character. (proto1 only) */ 156 static int escape_pending1; /* Last character was an escape (proto1 only) */ 157 static int last_was_cr; /* Last character was a newline. */ 158 static int exit_status; /* Used to store the command exit status. */ 159 static int stdin_eof; /* EOF has been encountered on stderr. */ 160 static Buffer stdin_buffer; /* Buffer for stdin data. */ 161 static Buffer stdout_buffer; /* Buffer for stdout data. */ 162 static Buffer stderr_buffer; /* Buffer for stderr data. */ 163 static u_int buffer_high; /* Soft max buffer size. */ 164 static int connection_in; /* Connection to server (input). */ 165 static int connection_out; /* Connection to server (output). */ 166 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 167 static int session_closed; /* In SSH2: login session closed. */ 168 static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 169 170 static void client_init_dispatch(void); 171 int session_ident = -1; 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 if (display == NULL) 291 return 0; 292 293 dlen = strlen(display); 294 for (i = 0; i < dlen; i++) { 295 if (!isalnum((u_char)display[i]) && 296 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 297 debug("Invalid character '%c' in DISPLAY", display[i]); 298 return 0; 299 } 300 } 301 return 1; 302 } 303 304 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 305 #define X11_TIMEOUT_SLACK 60 306 int 307 client_x11_get_proto(const char *display, const char *xauth_path, 308 u_int trusted, u_int timeout, char **_proto, char **_data) 309 { 310 char cmd[1024], line[512], xdisplay[512]; 311 char xauthfile[PATH_MAX], xauthdir[PATH_MAX]; 312 static char proto[512], data[512]; 313 FILE *f; 314 int got_data = 0, generated = 0, do_unlink = 0, r; 315 struct stat st; 316 u_int now, x11_timeout_real; 317 318 *_proto = proto; 319 *_data = data; 320 proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; 321 322 if (!client_x11_display_valid(display)) { 323 if (display != NULL) 324 logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", 325 display); 326 return -1; 327 } 328 if (xauth_path != NULL && stat(xauth_path, &st) == -1) { 329 debug("No xauth program."); 330 xauth_path = NULL; 331 } 332 333 if (xauth_path != NULL) { 334 /* 335 * Handle FamilyLocal case where $DISPLAY does 336 * not match an authorization entry. For this we 337 * just try "xauth list unix:displaynum.screennum". 338 * XXX: "localhost" match to determine FamilyLocal 339 * is not perfect. 340 */ 341 if (strncmp(display, "localhost:", 10) == 0) { 342 if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 343 display + 10)) < 0 || 344 (size_t)r >= sizeof(xdisplay)) { 345 error("%s: display name too long", __func__); 346 return -1; 347 } 348 display = xdisplay; 349 } 350 if (trusted == 0) { 351 /* 352 * Generate an untrusted X11 auth cookie. 353 * 354 * The authentication cookie should briefly outlive 355 * ssh's willingness to forward X11 connections to 356 * avoid nasty fail-open behaviour in the X server. 357 */ 358 mktemp_proto(xauthdir, sizeof(xauthdir)); 359 if (mkdtemp(xauthdir) == NULL) { 360 error("%s: mkdtemp: %s", 361 __func__, strerror(errno)); 362 return -1; 363 } 364 do_unlink = 1; 365 if ((r = snprintf(xauthfile, sizeof(xauthfile), 366 "%s/xauthfile", xauthdir)) < 0 || 367 (size_t)r >= sizeof(xauthfile)) { 368 error("%s: xauthfile path too long", __func__); 369 unlink(xauthfile); 370 rmdir(xauthdir); 371 return -1; 372 } 373 374 if (timeout >= UINT_MAX - X11_TIMEOUT_SLACK) 375 x11_timeout_real = UINT_MAX; 376 else 377 x11_timeout_real = timeout + X11_TIMEOUT_SLACK; 378 if ((r = snprintf(cmd, sizeof(cmd), 379 "%s -f %s generate %s " SSH_X11_PROTO 380 " untrusted timeout %u 2>" _PATH_DEVNULL, 381 xauth_path, xauthfile, display, 382 x11_timeout_real)) < 0 || 383 (size_t)r >= sizeof(cmd)) 384 fatal("%s: cmd too long", __func__); 385 debug2("%s: %s", __func__, cmd); 386 if (x11_refuse_time == 0) { 387 now = monotime() + 1; 388 if (UINT_MAX - timeout < now) 389 x11_refuse_time = UINT_MAX; 390 else 391 x11_refuse_time = now + timeout; 392 channel_set_x11_refuse_time(x11_refuse_time); 393 } 394 if (system(cmd) == 0) 395 generated = 1; 396 } 397 398 /* 399 * When in untrusted mode, we read the cookie only if it was 400 * successfully generated as an untrusted one in the step 401 * above. 402 */ 403 if (trusted || generated) { 404 snprintf(cmd, sizeof(cmd), 405 "%s %s%s list %s 2>" _PATH_DEVNULL, 406 xauth_path, 407 generated ? "-f " : "" , 408 generated ? xauthfile : "", 409 display); 410 debug2("x11_get_proto: %s", cmd); 411 f = popen(cmd, "r"); 412 if (f && fgets(line, sizeof(line), f) && 413 sscanf(line, "%*s %511s %511s", proto, data) == 2) 414 got_data = 1; 415 if (f) 416 pclose(f); 417 } 418 } 419 420 if (do_unlink) { 421 unlink(xauthfile); 422 rmdir(xauthdir); 423 } 424 425 /* Don't fall back to fake X11 data for untrusted forwarding */ 426 if (!trusted && !got_data) { 427 error("Warning: untrusted X11 forwarding setup failed: " 428 "xauth key data not generated"); 429 return -1; 430 } 431 432 /* 433 * If we didn't get authentication data, just make up some 434 * data. The forwarding code will check the validity of the 435 * response anyway, and substitute this data. The X11 436 * server, however, will ignore this fake data and use 437 * whatever authentication mechanisms it was using otherwise 438 * for the local connection. 439 */ 440 if (!got_data) { 441 u_int8_t rnd[16]; 442 u_int i; 443 444 logit("Warning: No xauth data; " 445 "using fake authentication data for X11 forwarding."); 446 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 447 arc4random_buf(rnd, sizeof(rnd)); 448 for (i = 0; i < sizeof(rnd); i++) { 449 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 450 rnd[i]); 451 } 452 } 453 454 return 0; 455 } 456 457 /* 458 * This is called when the interactive is entered. This checks if there is 459 * an EOF coming on stdin. We must check this explicitly, as select() does 460 * not appear to wake up when redirecting from /dev/null. 461 */ 462 463 static void 464 client_check_initial_eof_on_stdin(void) 465 { 466 int len; 467 char buf[1]; 468 469 /* 470 * If standard input is to be "redirected from /dev/null", we simply 471 * mark that we have seen an EOF and send an EOF message to the 472 * server. Otherwise, we try to read a single character; it appears 473 * that for some files, such /dev/null, select() never wakes up for 474 * read for this descriptor, which means that we never get EOF. This 475 * way we will get the EOF if stdin comes from /dev/null or similar. 476 */ 477 if (stdin_null_flag) { 478 /* Fake EOF on stdin. */ 479 debug("Sending eof."); 480 stdin_eof = 1; 481 packet_start(SSH_CMSG_EOF); 482 packet_send(); 483 } else { 484 enter_non_blocking(); 485 486 /* Check for immediate EOF on stdin. */ 487 len = read(fileno(stdin), buf, 1); 488 if (len == 0) { 489 /* 490 * EOF. Record that we have seen it and send 491 * EOF to server. 492 */ 493 debug("Sending eof."); 494 stdin_eof = 1; 495 packet_start(SSH_CMSG_EOF); 496 packet_send(); 497 } else if (len > 0) { 498 /* 499 * Got data. We must store the data in the buffer, 500 * and also process it as an escape character if 501 * appropriate. 502 */ 503 if ((u_char) buf[0] == escape_char1) 504 escape_pending1 = 1; 505 else 506 buffer_append(&stdin_buffer, buf, 1); 507 } 508 leave_non_blocking(); 509 } 510 } 511 512 513 /* 514 * Make packets from buffered stdin data, and buffer them for sending to the 515 * connection. 516 */ 517 518 static void 519 client_make_packets_from_stdin_data(void) 520 { 521 u_int len; 522 523 /* Send buffered stdin data to the server. */ 524 while (buffer_len(&stdin_buffer) > 0 && 525 packet_not_very_much_data_to_write()) { 526 len = buffer_len(&stdin_buffer); 527 /* Keep the packets at reasonable size. */ 528 if (len > packet_get_maxsize()) 529 len = packet_get_maxsize(); 530 packet_start(SSH_CMSG_STDIN_DATA); 531 packet_put_string(buffer_ptr(&stdin_buffer), len); 532 packet_send(); 533 buffer_consume(&stdin_buffer, len); 534 /* If we have a pending EOF, send it now. */ 535 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 536 packet_start(SSH_CMSG_EOF); 537 packet_send(); 538 } 539 } 540 } 541 542 /* 543 * Checks if the client window has changed, and sends a packet about it to 544 * the server if so. The actual change is detected elsewhere (by a software 545 * interrupt on Unix); this just checks the flag and sends a message if 546 * appropriate. 547 */ 548 549 static void 550 client_check_window_change(void) 551 { 552 struct winsize ws; 553 554 if (! received_window_change_signal) 555 return; 556 /** XXX race */ 557 received_window_change_signal = 0; 558 559 debug2("client_check_window_change: changed"); 560 561 if (compat20) { 562 channel_send_window_changes(); 563 } else { 564 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 565 return; 566 packet_start(SSH_CMSG_WINDOW_SIZE); 567 packet_put_int((u_int)ws.ws_row); 568 packet_put_int((u_int)ws.ws_col); 569 packet_put_int((u_int)ws.ws_xpixel); 570 packet_put_int((u_int)ws.ws_ypixel); 571 packet_send(); 572 } 573 } 574 575 static int 576 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 577 { 578 struct global_confirm *gc; 579 580 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 581 return 0; 582 if (gc->cb != NULL) 583 gc->cb(type, seq, gc->ctx); 584 if (--gc->ref_count <= 0) { 585 TAILQ_REMOVE(&global_confirms, gc, entry); 586 explicit_bzero(gc, sizeof(*gc)); 587 free(gc); 588 } 589 590 packet_set_alive_timeouts(0); 591 return 0; 592 } 593 594 static void 595 server_alive_check(void) 596 { 597 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 598 logit("Timeout, server %s not responding.", host); 599 cleanup_exit(255); 600 } 601 packet_start(SSH2_MSG_GLOBAL_REQUEST); 602 packet_put_cstring("keepalive (at) openssh.com"); 603 packet_put_char(1); /* boolean: want reply */ 604 packet_send(); 605 /* Insert an empty placeholder to maintain ordering */ 606 client_register_global_confirm(NULL, NULL); 607 } 608 609 /* 610 * Waits until the client can do something (some data becomes available on 611 * one of the file descriptors). 612 */ 613 static void 614 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 615 int *maxfdp, u_int *nallocp, int rekeying) 616 { 617 struct timeval tv, *tvp; 618 int timeout_secs; 619 time_t minwait_secs = 0, server_alive_time = 0, now = monotime(); 620 int ret; 621 622 /* Add any selections by the channel mechanism. */ 623 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 624 &minwait_secs, rekeying); 625 626 if (!compat20) { 627 /* Read from the connection, unless our buffers are full. */ 628 if (buffer_len(&stdout_buffer) < buffer_high && 629 buffer_len(&stderr_buffer) < buffer_high && 630 channel_not_very_much_buffered_data()) 631 FD_SET(connection_in, *readsetp); 632 /* 633 * Read from stdin, unless we have seen EOF or have very much 634 * buffered data to send to the server. 635 */ 636 if (!stdin_eof && packet_not_very_much_data_to_write()) 637 FD_SET(fileno(stdin), *readsetp); 638 639 /* Select stdout/stderr if have data in buffer. */ 640 if (buffer_len(&stdout_buffer) > 0) 641 FD_SET(fileno(stdout), *writesetp); 642 if (buffer_len(&stderr_buffer) > 0) 643 FD_SET(fileno(stderr), *writesetp); 644 } else { 645 /* channel_prepare_select could have closed the last channel */ 646 if (session_closed && !channel_still_open() && 647 !packet_have_data_to_write()) { 648 /* clear mask since we did not call select() */ 649 memset(*readsetp, 0, *nallocp); 650 memset(*writesetp, 0, *nallocp); 651 return; 652 } else { 653 FD_SET(connection_in, *readsetp); 654 } 655 } 656 657 /* Select server connection if have data to write to the server. */ 658 if (packet_have_data_to_write()) 659 FD_SET(connection_out, *writesetp); 660 661 /* 662 * Wait for something to happen. This will suspend the process until 663 * some selected descriptor can be read, written, or has some other 664 * event pending, or a timeout expires. 665 */ 666 667 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 668 if (options.server_alive_interval > 0 && compat20) { 669 timeout_secs = options.server_alive_interval; 670 server_alive_time = now + options.server_alive_interval; 671 } 672 if (options.rekey_interval > 0 && compat20 && !rekeying) 673 timeout_secs = MINIMUM(timeout_secs, packet_get_rekey_timeout()); 674 set_control_persist_exit_time(); 675 if (control_persist_exit_time > 0) { 676 timeout_secs = MINIMUM(timeout_secs, 677 control_persist_exit_time - now); 678 if (timeout_secs < 0) 679 timeout_secs = 0; 680 } 681 if (minwait_secs != 0) 682 timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs); 683 if (timeout_secs == INT_MAX) 684 tvp = NULL; 685 else { 686 tv.tv_sec = timeout_secs; 687 tv.tv_usec = 0; 688 tvp = &tv; 689 } 690 691 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 692 if (ret < 0) { 693 char buf[100]; 694 695 /* 696 * We have to clear the select masks, because we return. 697 * We have to return, because the mainloop checks for the flags 698 * set by the signal handlers. 699 */ 700 memset(*readsetp, 0, *nallocp); 701 memset(*writesetp, 0, *nallocp); 702 703 if (errno == EINTR) 704 return; 705 /* Note: we might still have data in the buffers. */ 706 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 707 buffer_append(&stderr_buffer, buf, strlen(buf)); 708 quit_pending = 1; 709 } else if (ret == 0) { 710 /* 711 * Timeout. Could have been either keepalive or rekeying. 712 * Keepalive we check here, rekeying is checked in clientloop. 713 */ 714 if (server_alive_time != 0 && server_alive_time <= monotime()) 715 server_alive_check(); 716 } 717 718 } 719 720 static void 721 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 722 { 723 /* Flush stdout and stderr buffers. */ 724 if (buffer_len(bout) > 0) 725 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 726 buffer_len(bout)); 727 if (buffer_len(berr) > 0) 728 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 729 buffer_len(berr)); 730 731 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 732 733 /* 734 * Free (and clear) the buffer to reduce the amount of data that gets 735 * written to swap. 736 */ 737 buffer_free(bin); 738 buffer_free(bout); 739 buffer_free(berr); 740 741 /* Send the suspend signal to the program itself. */ 742 kill(getpid(), SIGTSTP); 743 744 /* Reset window sizes in case they have changed */ 745 received_window_change_signal = 1; 746 747 /* OK, we have been continued by the user. Reinitialize buffers. */ 748 buffer_init(bin); 749 buffer_init(bout); 750 buffer_init(berr); 751 752 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 753 } 754 755 static void 756 client_process_net_input(fd_set *readset) 757 { 758 int len; 759 char buf[SSH_IOBUFSZ]; 760 761 /* 762 * Read input from the server, and add any such data to the buffer of 763 * the packet subsystem. 764 */ 765 if (FD_ISSET(connection_in, readset)) { 766 /* Read as much as possible. */ 767 len = read(connection_in, buf, sizeof(buf)); 768 if (len == 0) { 769 /* 770 * Received EOF. The remote host has closed the 771 * connection. 772 */ 773 snprintf(buf, sizeof buf, 774 "Connection to %.300s closed by remote host.\r\n", 775 host); 776 buffer_append(&stderr_buffer, buf, strlen(buf)); 777 quit_pending = 1; 778 return; 779 } 780 /* 781 * There is a kernel bug on Solaris that causes select to 782 * sometimes wake up even though there is no data available. 783 */ 784 if (len < 0 && 785 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 786 len = 0; 787 788 if (len < 0) { 789 /* 790 * An error has encountered. Perhaps there is a 791 * network problem. 792 */ 793 snprintf(buf, sizeof buf, 794 "Read from remote host %.300s: %.100s\r\n", 795 host, strerror(errno)); 796 buffer_append(&stderr_buffer, buf, strlen(buf)); 797 quit_pending = 1; 798 return; 799 } 800 packet_process_incoming(buf, len); 801 } 802 } 803 804 static void 805 client_status_confirm(int type, Channel *c, void *ctx) 806 { 807 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 808 char errmsg[256]; 809 int tochan; 810 811 /* 812 * If a TTY was explicitly requested, then a failure to allocate 813 * one is fatal. 814 */ 815 if (cr->action == CONFIRM_TTY && 816 (options.request_tty == REQUEST_TTY_FORCE || 817 options.request_tty == REQUEST_TTY_YES)) 818 cr->action = CONFIRM_CLOSE; 819 820 /* XXX supress on mux _client_ quietmode */ 821 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 822 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 823 824 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 825 debug2("%s request accepted on channel %d", 826 cr->request_type, c->self); 827 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 828 if (tochan) { 829 snprintf(errmsg, sizeof(errmsg), 830 "%s request failed\r\n", cr->request_type); 831 } else { 832 snprintf(errmsg, sizeof(errmsg), 833 "%s request failed on channel %d", 834 cr->request_type, c->self); 835 } 836 /* If error occurred on primary session channel, then exit */ 837 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 838 fatal("%s", errmsg); 839 /* 840 * If error occurred on mux client, append to 841 * their stderr. 842 */ 843 if (tochan) { 844 buffer_append(&c->extended, errmsg, 845 strlen(errmsg)); 846 } else 847 error("%s", errmsg); 848 if (cr->action == CONFIRM_TTY) { 849 /* 850 * If a TTY allocation error occurred, then arrange 851 * for the correct TTY to leave raw mode. 852 */ 853 if (c->self == session_ident) 854 leave_raw_mode(0); 855 else 856 mux_tty_alloc_failed(c); 857 } else if (cr->action == CONFIRM_CLOSE) { 858 chan_read_failed(c); 859 chan_write_failed(c); 860 } 861 } 862 free(cr); 863 } 864 865 static void 866 client_abandon_status_confirm(Channel *c, void *ctx) 867 { 868 free(ctx); 869 } 870 871 void 872 client_expect_confirm(int id, const char *request, 873 enum confirm_action action) 874 { 875 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 876 877 cr->request_type = request; 878 cr->action = action; 879 880 channel_register_status_confirm(id, client_status_confirm, 881 client_abandon_status_confirm, cr); 882 } 883 884 void 885 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 886 { 887 struct global_confirm *gc, *last_gc; 888 889 /* Coalesce identical callbacks */ 890 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 891 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 892 if (++last_gc->ref_count >= INT_MAX) 893 fatal("%s: last_gc->ref_count = %d", 894 __func__, last_gc->ref_count); 895 return; 896 } 897 898 gc = xcalloc(1, sizeof(*gc)); 899 gc->cb = cb; 900 gc->ctx = ctx; 901 gc->ref_count = 1; 902 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 903 } 904 905 static void 906 process_cmdline(void) 907 { 908 void (*handler)(int); 909 char *s, *cmd; 910 int ok, delete = 0, local = 0, remote = 0, dynamic = 0; 911 struct Forward fwd; 912 913 memset(&fwd, 0, sizeof(fwd)); 914 915 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 916 handler = signal(SIGINT, SIG_IGN); 917 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 918 if (s == NULL) 919 goto out; 920 while (isspace((u_char)*s)) 921 s++; 922 if (*s == '-') 923 s++; /* Skip cmdline '-', if any */ 924 if (*s == '\0') 925 goto out; 926 927 if (*s == 'h' || *s == 'H' || *s == '?') { 928 logit("Commands:"); 929 logit(" -L[bind_address:]port:host:hostport " 930 "Request local forward"); 931 logit(" -R[bind_address:]port:host:hostport " 932 "Request remote forward"); 933 logit(" -D[bind_address:]port " 934 "Request dynamic forward"); 935 logit(" -KL[bind_address:]port " 936 "Cancel local forward"); 937 logit(" -KR[bind_address:]port " 938 "Cancel remote forward"); 939 logit(" -KD[bind_address:]port " 940 "Cancel dynamic forward"); 941 if (!options.permit_local_command) 942 goto out; 943 logit(" !args " 944 "Execute local command"); 945 goto out; 946 } 947 948 if (*s == '!' && options.permit_local_command) { 949 s++; 950 ssh_local_cmd(s); 951 goto out; 952 } 953 954 if (*s == 'K') { 955 delete = 1; 956 s++; 957 } 958 if (*s == 'L') 959 local = 1; 960 else if (*s == 'R') 961 remote = 1; 962 else if (*s == 'D') 963 dynamic = 1; 964 else { 965 logit("Invalid command."); 966 goto out; 967 } 968 969 if (delete && !compat20) { 970 logit("Not supported for SSH protocol version 1."); 971 goto out; 972 } 973 974 while (isspace((u_char)*++s)) 975 ; 976 977 /* XXX update list of forwards in options */ 978 if (delete) { 979 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ 980 if (!parse_forward(&fwd, s, 1, 0)) { 981 logit("Bad forwarding close specification."); 982 goto out; 983 } 984 if (remote) 985 ok = channel_request_rforward_cancel(&fwd) == 0; 986 else if (dynamic) 987 ok = channel_cancel_lport_listener(&fwd, 988 0, &options.fwd_opts) > 0; 989 else 990 ok = channel_cancel_lport_listener(&fwd, 991 CHANNEL_CANCEL_PORT_STATIC, 992 &options.fwd_opts) > 0; 993 if (!ok) { 994 logit("Unknown port forwarding."); 995 goto out; 996 } 997 logit("Canceled forwarding."); 998 } else { 999 if (!parse_forward(&fwd, s, dynamic, remote)) { 1000 logit("Bad forwarding specification."); 1001 goto out; 1002 } 1003 if (local || dynamic) { 1004 if (!channel_setup_local_fwd_listener(&fwd, 1005 &options.fwd_opts)) { 1006 logit("Port forwarding failed."); 1007 goto out; 1008 } 1009 } else { 1010 if (channel_request_remote_forwarding(&fwd) < 0) { 1011 logit("Port forwarding failed."); 1012 goto out; 1013 } 1014 } 1015 logit("Forwarding port."); 1016 } 1017 1018 out: 1019 signal(SIGINT, handler); 1020 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1021 free(cmd); 1022 free(fwd.listen_host); 1023 free(fwd.listen_path); 1024 free(fwd.connect_host); 1025 free(fwd.connect_path); 1026 } 1027 1028 /* reasons to suppress output of an escape command in help output */ 1029 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 1030 #define SUPPRESS_PROTO1 1 /* don't show in protocol 1 sessions */ 1031 #define SUPPRESS_MUXCLIENT 2 /* don't show in mux client sessions */ 1032 #define SUPPRESS_MUXMASTER 4 /* don't show in mux master sessions */ 1033 #define SUPPRESS_SYSLOG 8 /* don't show when logging to syslog */ 1034 struct escape_help_text { 1035 const char *cmd; 1036 const char *text; 1037 unsigned int flags; 1038 }; 1039 static struct escape_help_text esc_txt[] = { 1040 {".", "terminate session", SUPPRESS_MUXMASTER}, 1041 {".", "terminate connection (and any multiplexed sessions)", 1042 SUPPRESS_MUXCLIENT}, 1043 {"B", "send a BREAK to the remote system", SUPPRESS_PROTO1}, 1044 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 1045 {"R", "request rekey", SUPPRESS_PROTO1}, 1046 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 1047 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 1048 {"#", "list forwarded connections", SUPPRESS_NEVER}, 1049 {"&", "background ssh (when waiting for connections to terminate)", 1050 SUPPRESS_MUXCLIENT}, 1051 {"?", "this message", SUPPRESS_NEVER}, 1052 }; 1053 1054 static void 1055 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client, 1056 int using_stderr) 1057 { 1058 unsigned int i, suppress_flags; 1059 char string[1024]; 1060 1061 snprintf(string, sizeof string, "%c?\r\n" 1062 "Supported escape sequences:\r\n", escape_char); 1063 buffer_append(b, string, strlen(string)); 1064 1065 suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) | 1066 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 1067 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 1068 (using_stderr ? 0 : SUPPRESS_SYSLOG); 1069 1070 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 1071 if (esc_txt[i].flags & suppress_flags) 1072 continue; 1073 snprintf(string, sizeof string, " %c%-3s - %s\r\n", 1074 escape_char, esc_txt[i].cmd, esc_txt[i].text); 1075 buffer_append(b, string, strlen(string)); 1076 } 1077 1078 snprintf(string, sizeof string, 1079 " %c%c - send the escape character by typing it twice\r\n" 1080 "(Note that escapes are only recognized immediately after " 1081 "newline.)\r\n", escape_char, escape_char); 1082 buffer_append(b, string, strlen(string)); 1083 } 1084 1085 /* 1086 * Process the characters one by one, call with c==NULL for proto1 case. 1087 */ 1088 static int 1089 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 1090 char *buf, int len) 1091 { 1092 char string[1024]; 1093 pid_t pid; 1094 int bytes = 0; 1095 u_int i; 1096 u_char ch; 1097 char *s; 1098 int *escape_pendingp, escape_char; 1099 struct escape_filter_ctx *efc; 1100 1101 if (c == NULL) { 1102 escape_pendingp = &escape_pending1; 1103 escape_char = escape_char1; 1104 } else { 1105 if (c->filter_ctx == NULL) 1106 return 0; 1107 efc = (struct escape_filter_ctx *)c->filter_ctx; 1108 escape_pendingp = &efc->escape_pending; 1109 escape_char = efc->escape_char; 1110 } 1111 1112 if (len <= 0) 1113 return (0); 1114 1115 for (i = 0; i < (u_int)len; i++) { 1116 /* Get one character at a time. */ 1117 ch = buf[i]; 1118 1119 if (*escape_pendingp) { 1120 /* We have previously seen an escape character. */ 1121 /* Clear the flag now. */ 1122 *escape_pendingp = 0; 1123 1124 /* Process the escaped character. */ 1125 switch (ch) { 1126 case '.': 1127 /* Terminate the connection. */ 1128 snprintf(string, sizeof string, "%c.\r\n", 1129 escape_char); 1130 buffer_append(berr, string, strlen(string)); 1131 1132 if (c && c->ctl_chan != -1) { 1133 chan_read_failed(c); 1134 chan_write_failed(c); 1135 if (c->detach_user) 1136 c->detach_user(c->self, NULL); 1137 c->type = SSH_CHANNEL_ABANDONED; 1138 buffer_clear(&c->input); 1139 chan_ibuf_empty(c); 1140 return 0; 1141 } else 1142 quit_pending = 1; 1143 return -1; 1144 1145 case 'Z' - 64: 1146 /* XXX support this for mux clients */ 1147 if (c && c->ctl_chan != -1) { 1148 char b[16]; 1149 noescape: 1150 if (ch == 'Z' - 64) 1151 snprintf(b, sizeof b, "^Z"); 1152 else 1153 snprintf(b, sizeof b, "%c", ch); 1154 snprintf(string, sizeof string, 1155 "%c%s escape not available to " 1156 "multiplexed sessions\r\n", 1157 escape_char, b); 1158 buffer_append(berr, string, 1159 strlen(string)); 1160 continue; 1161 } 1162 /* Suspend the program. Inform the user */ 1163 snprintf(string, sizeof string, 1164 "%c^Z [suspend ssh]\r\n", escape_char); 1165 buffer_append(berr, string, strlen(string)); 1166 1167 /* Restore terminal modes and suspend. */ 1168 client_suspend_self(bin, bout, berr); 1169 1170 /* We have been continued. */ 1171 continue; 1172 1173 case 'B': 1174 if (compat20) { 1175 snprintf(string, sizeof string, 1176 "%cB\r\n", escape_char); 1177 buffer_append(berr, string, 1178 strlen(string)); 1179 channel_request_start(c->self, 1180 "break", 0); 1181 packet_put_int(1000); 1182 packet_send(); 1183 } 1184 continue; 1185 1186 case 'R': 1187 if (compat20) { 1188 if (datafellows & SSH_BUG_NOREKEY) 1189 logit("Server does not " 1190 "support re-keying"); 1191 else 1192 need_rekeying = 1; 1193 } 1194 continue; 1195 1196 case 'V': 1197 /* FALLTHROUGH */ 1198 case 'v': 1199 if (c && c->ctl_chan != -1) 1200 goto noescape; 1201 if (!log_is_on_stderr()) { 1202 snprintf(string, sizeof string, 1203 "%c%c [Logging to syslog]\r\n", 1204 escape_char, ch); 1205 buffer_append(berr, string, 1206 strlen(string)); 1207 continue; 1208 } 1209 if (ch == 'V' && options.log_level > 1210 SYSLOG_LEVEL_QUIET) 1211 log_change_level(--options.log_level); 1212 if (ch == 'v' && options.log_level < 1213 SYSLOG_LEVEL_DEBUG3) 1214 log_change_level(++options.log_level); 1215 snprintf(string, sizeof string, 1216 "%c%c [LogLevel %s]\r\n", escape_char, ch, 1217 log_level_name(options.log_level)); 1218 buffer_append(berr, string, strlen(string)); 1219 continue; 1220 1221 case '&': 1222 if (c && c->ctl_chan != -1) 1223 goto noescape; 1224 /* 1225 * Detach the program (continue to serve 1226 * connections, but put in background and no 1227 * more new connections). 1228 */ 1229 /* Restore tty modes. */ 1230 leave_raw_mode( 1231 options.request_tty == REQUEST_TTY_FORCE); 1232 1233 /* Stop listening for new connections. */ 1234 channel_stop_listening(); 1235 1236 snprintf(string, sizeof string, 1237 "%c& [backgrounded]\n", escape_char); 1238 buffer_append(berr, string, strlen(string)); 1239 1240 /* Fork into background. */ 1241 pid = fork(); 1242 if (pid < 0) { 1243 error("fork: %.100s", strerror(errno)); 1244 continue; 1245 } 1246 if (pid != 0) { /* This is the parent. */ 1247 /* The parent just exits. */ 1248 exit(0); 1249 } 1250 /* The child continues serving connections. */ 1251 if (compat20) { 1252 buffer_append(bin, "\004", 1); 1253 /* fake EOF on stdin */ 1254 return -1; 1255 } else if (!stdin_eof) { 1256 /* 1257 * Sending SSH_CMSG_EOF alone does not 1258 * always appear to be enough. So we 1259 * try to send an EOF character first. 1260 */ 1261 packet_start(SSH_CMSG_STDIN_DATA); 1262 packet_put_string("\004", 1); 1263 packet_send(); 1264 /* Close stdin. */ 1265 stdin_eof = 1; 1266 if (buffer_len(bin) == 0) { 1267 packet_start(SSH_CMSG_EOF); 1268 packet_send(); 1269 } 1270 } 1271 continue; 1272 1273 case '?': 1274 print_escape_help(berr, escape_char, compat20, 1275 (c && c->ctl_chan != -1), 1276 log_is_on_stderr()); 1277 continue; 1278 1279 case '#': 1280 snprintf(string, sizeof string, "%c#\r\n", 1281 escape_char); 1282 buffer_append(berr, string, strlen(string)); 1283 s = channel_open_message(); 1284 buffer_append(berr, s, strlen(s)); 1285 free(s); 1286 continue; 1287 1288 case 'C': 1289 if (c && c->ctl_chan != -1) 1290 goto noescape; 1291 process_cmdline(); 1292 continue; 1293 1294 default: 1295 if (ch != escape_char) { 1296 buffer_put_char(bin, escape_char); 1297 bytes++; 1298 } 1299 /* Escaped characters fall through here */ 1300 break; 1301 } 1302 } else { 1303 /* 1304 * The previous character was not an escape char. 1305 * Check if this is an escape. 1306 */ 1307 if (last_was_cr && ch == escape_char) { 1308 /* 1309 * It is. Set the flag and continue to 1310 * next character. 1311 */ 1312 *escape_pendingp = 1; 1313 continue; 1314 } 1315 } 1316 1317 /* 1318 * Normal character. Record whether it was a newline, 1319 * and append it to the buffer. 1320 */ 1321 last_was_cr = (ch == '\r' || ch == '\n'); 1322 buffer_put_char(bin, ch); 1323 bytes++; 1324 } 1325 return bytes; 1326 } 1327 1328 static void 1329 client_process_input(fd_set *readset) 1330 { 1331 int len; 1332 char buf[SSH_IOBUFSZ]; 1333 1334 /* Read input from stdin. */ 1335 if (FD_ISSET(fileno(stdin), readset)) { 1336 /* Read as much as possible. */ 1337 len = read(fileno(stdin), buf, sizeof(buf)); 1338 if (len < 0 && 1339 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1340 return; /* we'll try again later */ 1341 if (len <= 0) { 1342 /* 1343 * Received EOF or error. They are treated 1344 * similarly, except that an error message is printed 1345 * if it was an error condition. 1346 */ 1347 if (len < 0) { 1348 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1349 strerror(errno)); 1350 buffer_append(&stderr_buffer, buf, strlen(buf)); 1351 } 1352 /* Mark that we have seen EOF. */ 1353 stdin_eof = 1; 1354 /* 1355 * Send an EOF message to the server unless there is 1356 * data in the buffer. If there is data in the 1357 * buffer, no message will be sent now. Code 1358 * elsewhere will send the EOF when the buffer 1359 * becomes empty if stdin_eof is set. 1360 */ 1361 if (buffer_len(&stdin_buffer) == 0) { 1362 packet_start(SSH_CMSG_EOF); 1363 packet_send(); 1364 } 1365 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1366 /* 1367 * Normal successful read, and no escape character. 1368 * Just append the data to buffer. 1369 */ 1370 buffer_append(&stdin_buffer, buf, len); 1371 } else { 1372 /* 1373 * Normal, successful read. But we have an escape 1374 * character and have to process the characters one 1375 * by one. 1376 */ 1377 if (process_escapes(NULL, &stdin_buffer, 1378 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1379 return; 1380 } 1381 } 1382 } 1383 1384 static void 1385 client_process_output(fd_set *writeset) 1386 { 1387 int len; 1388 char buf[100]; 1389 1390 /* Write buffered output to stdout. */ 1391 if (FD_ISSET(fileno(stdout), writeset)) { 1392 /* Write as much data as possible. */ 1393 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1394 buffer_len(&stdout_buffer)); 1395 if (len <= 0) { 1396 if (errno == EINTR || errno == EAGAIN || 1397 errno == EWOULDBLOCK) 1398 len = 0; 1399 else { 1400 /* 1401 * An error or EOF was encountered. Put an 1402 * error message to stderr buffer. 1403 */ 1404 snprintf(buf, sizeof buf, 1405 "write stdout: %.50s\r\n", strerror(errno)); 1406 buffer_append(&stderr_buffer, buf, strlen(buf)); 1407 quit_pending = 1; 1408 return; 1409 } 1410 } 1411 /* Consume printed data from the buffer. */ 1412 buffer_consume(&stdout_buffer, len); 1413 } 1414 /* Write buffered output to stderr. */ 1415 if (FD_ISSET(fileno(stderr), writeset)) { 1416 /* Write as much data as possible. */ 1417 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1418 buffer_len(&stderr_buffer)); 1419 if (len <= 0) { 1420 if (errno == EINTR || errno == EAGAIN || 1421 errno == EWOULDBLOCK) 1422 len = 0; 1423 else { 1424 /* 1425 * EOF or error, but can't even print 1426 * error message. 1427 */ 1428 quit_pending = 1; 1429 return; 1430 } 1431 } 1432 /* Consume printed characters from the buffer. */ 1433 buffer_consume(&stderr_buffer, len); 1434 } 1435 } 1436 1437 /* 1438 * Get packets from the connection input buffer, and process them as long as 1439 * there are packets available. 1440 * 1441 * Any unknown packets received during the actual 1442 * session cause the session to terminate. This is 1443 * intended to make debugging easier since no 1444 * confirmations are sent. Any compatible protocol 1445 * extensions must be negotiated during the 1446 * preparatory phase. 1447 */ 1448 1449 static void 1450 client_process_buffered_input_packets(void) 1451 { 1452 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, active_state); 1453 } 1454 1455 /* scan buf[] for '~' before sending data to the peer */ 1456 1457 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1458 void * 1459 client_new_escape_filter_ctx(int escape_char) 1460 { 1461 struct escape_filter_ctx *ret; 1462 1463 ret = xcalloc(1, sizeof(*ret)); 1464 ret->escape_pending = 0; 1465 ret->escape_char = escape_char; 1466 return (void *)ret; 1467 } 1468 1469 /* Free the escape filter context on channel free */ 1470 void 1471 client_filter_cleanup(int cid, void *ctx) 1472 { 1473 free(ctx); 1474 } 1475 1476 int 1477 client_simple_escape_filter(Channel *c, char *buf, int len) 1478 { 1479 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1480 return 0; 1481 1482 return process_escapes(c, &c->input, &c->output, &c->extended, 1483 buf, len); 1484 } 1485 1486 static void 1487 client_channel_closed(int id, void *arg) 1488 { 1489 channel_cancel_cleanup(id); 1490 session_closed = 1; 1491 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1492 } 1493 1494 /* 1495 * Implements the interactive session with the server. This is called after 1496 * the user has been authenticated, and a command has been started on the 1497 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1498 * used as an escape character for terminating or suspending the session. 1499 */ 1500 1501 int 1502 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1503 { 1504 fd_set *readset = NULL, *writeset = NULL; 1505 double start_time, total_time; 1506 int r, max_fd = 0, max_fd2 = 0, len; 1507 u_int64_t ibytes, obytes; 1508 u_int nalloc = 0; 1509 char buf[100]; 1510 1511 debug("Entering interactive session."); 1512 1513 if (options.control_master && 1514 !option_clear_or_none(options.control_path)) { 1515 debug("pledge: id"); 1516 if (pledge("stdio rpath wpath cpath unix inet dns recvfd proc exec id tty", 1517 NULL) == -1) 1518 fatal("%s pledge(): %s", __func__, strerror(errno)); 1519 1520 } else if (options.forward_x11 || options.permit_local_command) { 1521 debug("pledge: exec"); 1522 if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty", 1523 NULL) == -1) 1524 fatal("%s pledge(): %s", __func__, strerror(errno)); 1525 1526 } else if (options.update_hostkeys) { 1527 debug("pledge: filesystem full"); 1528 if (pledge("stdio rpath wpath cpath unix inet dns proc tty", 1529 NULL) == -1) 1530 fatal("%s pledge(): %s", __func__, strerror(errno)); 1531 1532 } else if (!option_clear_or_none(options.proxy_command) || 1533 fork_after_authentication_flag) { 1534 debug("pledge: proc"); 1535 if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1) 1536 fatal("%s pledge(): %s", __func__, strerror(errno)); 1537 1538 } else { 1539 debug("pledge: network"); 1540 if (pledge("stdio unix inet dns tty", NULL) == -1) 1541 fatal("%s pledge(): %s", __func__, strerror(errno)); 1542 } 1543 1544 start_time = get_current_time(); 1545 1546 /* Initialize variables. */ 1547 escape_pending1 = 0; 1548 last_was_cr = 1; 1549 exit_status = -1; 1550 stdin_eof = 0; 1551 buffer_high = 64 * 1024; 1552 connection_in = packet_get_connection_in(); 1553 connection_out = packet_get_connection_out(); 1554 max_fd = MAXIMUM(connection_in, connection_out); 1555 1556 if (!compat20) { 1557 /* enable nonblocking unless tty */ 1558 if (!isatty(fileno(stdin))) 1559 set_nonblock(fileno(stdin)); 1560 if (!isatty(fileno(stdout))) 1561 set_nonblock(fileno(stdout)); 1562 if (!isatty(fileno(stderr))) 1563 set_nonblock(fileno(stderr)); 1564 max_fd = MAXIMUM(max_fd, fileno(stdin)); 1565 max_fd = MAXIMUM(max_fd, fileno(stdout)); 1566 max_fd = MAXIMUM(max_fd, fileno(stderr)); 1567 } 1568 quit_pending = 0; 1569 escape_char1 = escape_char_arg; 1570 1571 /* Initialize buffers. */ 1572 buffer_init(&stdin_buffer); 1573 buffer_init(&stdout_buffer); 1574 buffer_init(&stderr_buffer); 1575 1576 client_init_dispatch(); 1577 1578 /* 1579 * Set signal handlers, (e.g. to restore non-blocking mode) 1580 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1581 */ 1582 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1583 signal(SIGHUP, signal_handler); 1584 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1585 signal(SIGINT, signal_handler); 1586 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1587 signal(SIGQUIT, signal_handler); 1588 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1589 signal(SIGTERM, signal_handler); 1590 signal(SIGWINCH, window_change_handler); 1591 1592 if (have_pty) 1593 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1594 1595 if (compat20) { 1596 session_ident = ssh2_chan_id; 1597 if (session_ident != -1) { 1598 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1599 channel_register_filter(session_ident, 1600 client_simple_escape_filter, NULL, 1601 client_filter_cleanup, 1602 client_new_escape_filter_ctx( 1603 escape_char_arg)); 1604 } 1605 channel_register_cleanup(session_ident, 1606 client_channel_closed, 0); 1607 } 1608 } else { 1609 /* Check if we should immediately send eof on stdin. */ 1610 client_check_initial_eof_on_stdin(); 1611 } 1612 1613 /* Main loop of the client for the interactive session mode. */ 1614 while (!quit_pending) { 1615 1616 /* Process buffered packets sent by the server. */ 1617 client_process_buffered_input_packets(); 1618 1619 if (compat20 && session_closed && !channel_still_open()) 1620 break; 1621 1622 if (ssh_packet_is_rekeying(active_state)) { 1623 debug("rekeying in progress"); 1624 } else if (need_rekeying) { 1625 /* manual rekey request */ 1626 debug("need rekeying"); 1627 if ((r = kex_start_rekex(active_state)) != 0) 1628 fatal("%s: kex_start_rekex: %s", __func__, 1629 ssh_err(r)); 1630 need_rekeying = 0; 1631 } else { 1632 /* 1633 * Make packets of buffered stdin data, and buffer 1634 * them for sending to the server. 1635 */ 1636 if (!compat20) 1637 client_make_packets_from_stdin_data(); 1638 1639 /* 1640 * Make packets from buffered channel data, and 1641 * enqueue them for sending to the server. 1642 */ 1643 if (packet_not_very_much_data_to_write()) 1644 channel_output_poll(); 1645 1646 /* 1647 * Check if the window size has changed, and buffer a 1648 * message about it to the server if so. 1649 */ 1650 client_check_window_change(); 1651 1652 if (quit_pending) 1653 break; 1654 } 1655 /* 1656 * Wait until we have something to do (something becomes 1657 * available on one of the descriptors). 1658 */ 1659 max_fd2 = max_fd; 1660 client_wait_until_can_do_something(&readset, &writeset, 1661 &max_fd2, &nalloc, ssh_packet_is_rekeying(active_state)); 1662 1663 if (quit_pending) 1664 break; 1665 1666 /* Do channel operations unless rekeying in progress. */ 1667 if (!ssh_packet_is_rekeying(active_state)) 1668 channel_after_select(readset, writeset); 1669 1670 /* Buffer input from the connection. */ 1671 client_process_net_input(readset); 1672 1673 if (quit_pending) 1674 break; 1675 1676 if (!compat20) { 1677 /* Buffer data from stdin */ 1678 client_process_input(readset); 1679 /* 1680 * Process output to stdout and stderr. Output to 1681 * the connection is processed elsewhere (above). 1682 */ 1683 client_process_output(writeset); 1684 } 1685 1686 /* 1687 * Send as much buffered packet data as possible to the 1688 * sender. 1689 */ 1690 if (FD_ISSET(connection_out, writeset)) 1691 packet_write_poll(); 1692 1693 /* 1694 * If we are a backgrounded control master, and the 1695 * timeout has expired without any active client 1696 * connections, then quit. 1697 */ 1698 if (control_persist_exit_time > 0) { 1699 if (monotime() >= control_persist_exit_time) { 1700 debug("ControlPersist timeout expired"); 1701 break; 1702 } 1703 } 1704 } 1705 free(readset); 1706 free(writeset); 1707 1708 /* Terminate the session. */ 1709 1710 /* Stop watching for window change. */ 1711 signal(SIGWINCH, SIG_DFL); 1712 1713 if (compat20) { 1714 packet_start(SSH2_MSG_DISCONNECT); 1715 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1716 packet_put_cstring("disconnected by user"); 1717 packet_put_cstring(""); /* language tag */ 1718 packet_send(); 1719 packet_write_wait(); 1720 } 1721 1722 channel_free_all(); 1723 1724 if (have_pty) 1725 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1726 1727 /* restore blocking io */ 1728 if (!isatty(fileno(stdin))) 1729 unset_nonblock(fileno(stdin)); 1730 if (!isatty(fileno(stdout))) 1731 unset_nonblock(fileno(stdout)); 1732 if (!isatty(fileno(stderr))) 1733 unset_nonblock(fileno(stderr)); 1734 1735 /* 1736 * If there was no shell or command requested, there will be no remote 1737 * exit status to be returned. In that case, clear error code if the 1738 * connection was deliberately terminated at this end. 1739 */ 1740 if (no_shell_flag && received_signal == SIGTERM) { 1741 received_signal = 0; 1742 exit_status = 0; 1743 } 1744 1745 if (received_signal) 1746 fatal("Killed by signal %d.", (int) received_signal); 1747 1748 /* 1749 * In interactive mode (with pseudo tty) display a message indicating 1750 * that the connection has been closed. 1751 */ 1752 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1753 snprintf(buf, sizeof buf, 1754 "Connection to %.64s closed.\r\n", host); 1755 buffer_append(&stderr_buffer, buf, strlen(buf)); 1756 } 1757 1758 /* Output any buffered data for stdout. */ 1759 if (buffer_len(&stdout_buffer) > 0) { 1760 len = atomicio(vwrite, fileno(stdout), 1761 buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer)); 1762 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer)) 1763 error("Write failed flushing stdout buffer."); 1764 else 1765 buffer_consume(&stdout_buffer, len); 1766 } 1767 1768 /* Output any buffered data for stderr. */ 1769 if (buffer_len(&stderr_buffer) > 0) { 1770 len = atomicio(vwrite, fileno(stderr), 1771 buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer)); 1772 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer)) 1773 error("Write failed flushing stderr buffer."); 1774 else 1775 buffer_consume(&stderr_buffer, len); 1776 } 1777 1778 /* Clear and free any buffers. */ 1779 explicit_bzero(buf, sizeof(buf)); 1780 buffer_free(&stdin_buffer); 1781 buffer_free(&stdout_buffer); 1782 buffer_free(&stderr_buffer); 1783 1784 /* Report bytes transferred, and transfer rates. */ 1785 total_time = get_current_time() - start_time; 1786 packet_get_bytes(&ibytes, &obytes); 1787 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1788 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1789 if (total_time > 0) 1790 verbose("Bytes per second: sent %.1f, received %.1f", 1791 obytes / total_time, ibytes / total_time); 1792 /* Return the exit status of the program. */ 1793 debug("Exit status %d", exit_status); 1794 return exit_status; 1795 } 1796 1797 /*********/ 1798 1799 static int 1800 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1801 { 1802 u_int data_len; 1803 char *data = packet_get_string(&data_len); 1804 packet_check_eom(); 1805 buffer_append(&stdout_buffer, data, data_len); 1806 explicit_bzero(data, data_len); 1807 free(data); 1808 return 0; 1809 } 1810 static int 1811 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1812 { 1813 u_int data_len; 1814 char *data = packet_get_string(&data_len); 1815 packet_check_eom(); 1816 buffer_append(&stderr_buffer, data, data_len); 1817 explicit_bzero(data, data_len); 1818 free(data); 1819 return 0; 1820 } 1821 static int 1822 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1823 { 1824 exit_status = packet_get_int(); 1825 packet_check_eom(); 1826 /* Acknowledge the exit. */ 1827 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1828 packet_send(); 1829 /* 1830 * Must wait for packet to be sent since we are 1831 * exiting the loop. 1832 */ 1833 packet_write_wait(); 1834 /* Flag that we want to exit. */ 1835 quit_pending = 1; 1836 return 0; 1837 } 1838 1839 static int 1840 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1841 { 1842 Channel *c = NULL; 1843 int r, remote_id, sock; 1844 1845 /* Read the remote channel number from the message. */ 1846 remote_id = packet_get_int(); 1847 packet_check_eom(); 1848 1849 /* 1850 * Get a connection to the local authentication agent (this may again 1851 * get forwarded). 1852 */ 1853 if ((r = ssh_get_authentication_socket(&sock)) != 0 && 1854 r != SSH_ERR_AGENT_NOT_PRESENT) 1855 debug("%s: ssh_get_authentication_socket: %s", 1856 __func__, ssh_err(r)); 1857 1858 1859 /* 1860 * If we could not connect the agent, send an error message back to 1861 * the server. This should never happen unless the agent dies, 1862 * because authentication forwarding is only enabled if we have an 1863 * agent. 1864 */ 1865 if (sock >= 0) { 1866 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1867 -1, 0, 0, 0, "authentication agent connection", 1); 1868 c->remote_id = remote_id; 1869 c->force_drain = 1; 1870 } 1871 if (c == NULL) { 1872 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1873 packet_put_int(remote_id); 1874 } else { 1875 /* Send a confirmation to the remote host. */ 1876 debug("Forwarding authentication connection."); 1877 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1878 packet_put_int(remote_id); 1879 packet_put_int(c->self); 1880 } 1881 packet_send(); 1882 return 0; 1883 } 1884 1885 static Channel * 1886 client_request_forwarded_tcpip(const char *request_type, int rchan, 1887 u_int rwindow, u_int rmaxpack) 1888 { 1889 Channel *c = NULL; 1890 struct sshbuf *b = NULL; 1891 char *listen_address, *originator_address; 1892 u_short listen_port, originator_port; 1893 int r; 1894 1895 /* Get rest of the packet */ 1896 listen_address = packet_get_string(NULL); 1897 listen_port = packet_get_int(); 1898 originator_address = packet_get_string(NULL); 1899 originator_port = packet_get_int(); 1900 packet_check_eom(); 1901 1902 debug("%s: listen %s port %d, originator %s port %d", __func__, 1903 listen_address, listen_port, originator_address, originator_port); 1904 1905 c = channel_connect_by_listen_address(listen_address, listen_port, 1906 "forwarded-tcpip", originator_address); 1907 1908 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1909 if ((b = sshbuf_new()) == NULL) { 1910 error("%s: alloc reply", __func__); 1911 goto out; 1912 } 1913 /* reconstruct and send to muxclient */ 1914 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */ 1915 (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1916 (r = sshbuf_put_cstring(b, request_type)) != 0 || 1917 (r = sshbuf_put_u32(b, rchan)) != 0 || 1918 (r = sshbuf_put_u32(b, rwindow)) != 0 || 1919 (r = sshbuf_put_u32(b, rmaxpack)) != 0 || 1920 (r = sshbuf_put_cstring(b, listen_address)) != 0 || 1921 (r = sshbuf_put_u32(b, listen_port)) != 0 || 1922 (r = sshbuf_put_cstring(b, originator_address)) != 0 || 1923 (r = sshbuf_put_u32(b, originator_port)) != 0 || 1924 (r = sshbuf_put_stringb(&c->output, b)) != 0) { 1925 error("%s: compose for muxclient %s", __func__, 1926 ssh_err(r)); 1927 goto out; 1928 } 1929 } 1930 1931 out: 1932 sshbuf_free(b); 1933 free(originator_address); 1934 free(listen_address); 1935 return c; 1936 } 1937 1938 static Channel * 1939 client_request_forwarded_streamlocal(const char *request_type, int rchan) 1940 { 1941 Channel *c = NULL; 1942 char *listen_path; 1943 1944 /* Get the remote path. */ 1945 listen_path = packet_get_string(NULL); 1946 /* XXX: Skip reserved field for now. */ 1947 if (packet_get_string_ptr(NULL) == NULL) 1948 fatal("%s: packet_get_string_ptr failed", __func__); 1949 packet_check_eom(); 1950 1951 debug("%s: %s", __func__, listen_path); 1952 1953 c = channel_connect_by_listen_path(listen_path, 1954 "forwarded-streamlocal (at) openssh.com", "forwarded-streamlocal"); 1955 free(listen_path); 1956 return c; 1957 } 1958 1959 static Channel * 1960 client_request_x11(const char *request_type, int rchan) 1961 { 1962 Channel *c = NULL; 1963 char *originator; 1964 u_short originator_port; 1965 int sock; 1966 1967 if (!options.forward_x11) { 1968 error("Warning: ssh server tried X11 forwarding."); 1969 error("Warning: this is probably a break-in attempt by a " 1970 "malicious server."); 1971 return NULL; 1972 } 1973 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) { 1974 verbose("Rejected X11 connection after ForwardX11Timeout " 1975 "expired"); 1976 return NULL; 1977 } 1978 originator = packet_get_string(NULL); 1979 if (datafellows & SSH_BUG_X11FWD) { 1980 debug2("buggy server: x11 request w/o originator_port"); 1981 originator_port = 0; 1982 } else { 1983 originator_port = packet_get_int(); 1984 } 1985 packet_check_eom(); 1986 /* XXX check permission */ 1987 debug("client_request_x11: request from %s %d", originator, 1988 originator_port); 1989 free(originator); 1990 sock = x11_connect_display(); 1991 if (sock < 0) 1992 return NULL; 1993 c = channel_new("x11", 1994 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1995 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1996 c->force_drain = 1; 1997 return c; 1998 } 1999 2000 static Channel * 2001 client_request_agent(const char *request_type, int rchan) 2002 { 2003 Channel *c = NULL; 2004 int r, sock; 2005 2006 if (!options.forward_agent) { 2007 error("Warning: ssh server tried agent forwarding."); 2008 error("Warning: this is probably a break-in attempt by a " 2009 "malicious server."); 2010 return NULL; 2011 } 2012 if ((r = ssh_get_authentication_socket(&sock)) != 0) { 2013 if (r != SSH_ERR_AGENT_NOT_PRESENT) 2014 debug("%s: ssh_get_authentication_socket: %s", 2015 __func__, ssh_err(r)); 2016 return NULL; 2017 } 2018 c = channel_new("authentication agent connection", 2019 SSH_CHANNEL_OPEN, sock, sock, -1, 2020 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 2021 "authentication agent connection", 1); 2022 c->force_drain = 1; 2023 return c; 2024 } 2025 2026 int 2027 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 2028 { 2029 Channel *c; 2030 int fd; 2031 2032 if (tun_mode == SSH_TUNMODE_NO) 2033 return 0; 2034 2035 if (!compat20) { 2036 error("Tunnel forwarding is not supported for protocol 1"); 2037 return -1; 2038 } 2039 2040 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 2041 2042 /* Open local tunnel device */ 2043 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 2044 error("Tunnel device open failed."); 2045 return -1; 2046 } 2047 2048 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 2049 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 2050 c->datagram = 1; 2051 2052 #if defined(SSH_TUN_FILTER) 2053 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 2054 channel_register_filter(c->self, sys_tun_infilter, 2055 sys_tun_outfilter, NULL, NULL); 2056 #endif 2057 2058 packet_start(SSH2_MSG_CHANNEL_OPEN); 2059 packet_put_cstring("tun (at) openssh.com"); 2060 packet_put_int(c->self); 2061 packet_put_int(c->local_window_max); 2062 packet_put_int(c->local_maxpacket); 2063 packet_put_int(tun_mode); 2064 packet_put_int(remote_tun); 2065 packet_send(); 2066 2067 return 0; 2068 } 2069 2070 /* XXXX move to generic input handler */ 2071 static int 2072 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 2073 { 2074 Channel *c = NULL; 2075 char *ctype; 2076 int rchan; 2077 u_int rmaxpack, rwindow, len; 2078 2079 ctype = packet_get_string(&len); 2080 rchan = packet_get_int(); 2081 rwindow = packet_get_int(); 2082 rmaxpack = packet_get_int(); 2083 2084 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 2085 ctype, rchan, rwindow, rmaxpack); 2086 2087 if (strcmp(ctype, "forwarded-tcpip") == 0) { 2088 c = client_request_forwarded_tcpip(ctype, rchan, rwindow, 2089 rmaxpack); 2090 } else if (strcmp(ctype, "forwarded-streamlocal (at) openssh.com") == 0) { 2091 c = client_request_forwarded_streamlocal(ctype, rchan); 2092 } else if (strcmp(ctype, "x11") == 0) { 2093 c = client_request_x11(ctype, rchan); 2094 } else if (strcmp(ctype, "auth-agent (at) openssh.com") == 0) { 2095 c = client_request_agent(ctype, rchan); 2096 } 2097 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 2098 debug3("proxied to downstream: %s", ctype); 2099 } else if (c != NULL) { 2100 debug("confirm %s", ctype); 2101 c->remote_id = rchan; 2102 c->remote_window = rwindow; 2103 c->remote_maxpacket = rmaxpack; 2104 if (c->type != SSH_CHANNEL_CONNECTING) { 2105 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 2106 packet_put_int(c->remote_id); 2107 packet_put_int(c->self); 2108 packet_put_int(c->local_window); 2109 packet_put_int(c->local_maxpacket); 2110 packet_send(); 2111 } 2112 } else { 2113 debug("failure %s", ctype); 2114 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 2115 packet_put_int(rchan); 2116 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 2117 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 2118 packet_put_cstring("open failed"); 2119 packet_put_cstring(""); 2120 } 2121 packet_send(); 2122 } 2123 free(ctype); 2124 return 0; 2125 } 2126 2127 static int 2128 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 2129 { 2130 Channel *c = NULL; 2131 int exitval, id, reply, success = 0; 2132 char *rtype; 2133 2134 id = packet_get_int(); 2135 c = channel_lookup(id); 2136 if (channel_proxy_upstream(c, type, seq, ctxt)) 2137 return 0; 2138 rtype = packet_get_string(NULL); 2139 reply = packet_get_char(); 2140 2141 debug("client_input_channel_req: channel %d rtype %s reply %d", 2142 id, rtype, reply); 2143 2144 if (id == -1) { 2145 error("client_input_channel_req: request for channel -1"); 2146 } else if (c == NULL) { 2147 error("client_input_channel_req: channel %d: " 2148 "unknown channel", id); 2149 } else if (strcmp(rtype, "eow (at) openssh.com") == 0) { 2150 packet_check_eom(); 2151 chan_rcvd_eow(c); 2152 } else if (strcmp(rtype, "exit-status") == 0) { 2153 exitval = packet_get_int(); 2154 if (c->ctl_chan != -1) { 2155 mux_exit_message(c, exitval); 2156 success = 1; 2157 } else if (id == session_ident) { 2158 /* Record exit value of local session */ 2159 success = 1; 2160 exit_status = exitval; 2161 } else { 2162 /* Probably for a mux channel that has already closed */ 2163 debug("%s: no sink for exit-status on channel %d", 2164 __func__, id); 2165 } 2166 packet_check_eom(); 2167 } 2168 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { 2169 packet_start(success ? 2170 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 2171 packet_put_int(c->remote_id); 2172 packet_send(); 2173 } 2174 free(rtype); 2175 return 0; 2176 } 2177 2178 struct hostkeys_update_ctx { 2179 /* The hostname and (optionally) IP address string for the server */ 2180 char *host_str, *ip_str; 2181 2182 /* 2183 * Keys received from the server and a flag for each indicating 2184 * whether they already exist in known_hosts. 2185 * keys_seen is filled in by hostkeys_find() and later (for new 2186 * keys) by client_global_hostkeys_private_confirm(). 2187 */ 2188 struct sshkey **keys; 2189 int *keys_seen; 2190 size_t nkeys; 2191 2192 size_t nnew; 2193 2194 /* 2195 * Keys that are in known_hosts, but were not present in the update 2196 * from the server (i.e. scheduled to be deleted). 2197 * Filled in by hostkeys_find(). 2198 */ 2199 struct sshkey **old_keys; 2200 size_t nold; 2201 }; 2202 2203 static void 2204 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx) 2205 { 2206 size_t i; 2207 2208 if (ctx == NULL) 2209 return; 2210 for (i = 0; i < ctx->nkeys; i++) 2211 sshkey_free(ctx->keys[i]); 2212 free(ctx->keys); 2213 free(ctx->keys_seen); 2214 for (i = 0; i < ctx->nold; i++) 2215 sshkey_free(ctx->old_keys[i]); 2216 free(ctx->old_keys); 2217 free(ctx->host_str); 2218 free(ctx->ip_str); 2219 free(ctx); 2220 } 2221 2222 static int 2223 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx) 2224 { 2225 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2226 size_t i; 2227 struct sshkey **tmp; 2228 2229 if (l->status != HKF_STATUS_MATCHED || l->key == NULL || 2230 l->key->type == KEY_RSA1) 2231 return 0; 2232 2233 /* Mark off keys we've already seen for this host */ 2234 for (i = 0; i < ctx->nkeys; i++) { 2235 if (sshkey_equal(l->key, ctx->keys[i])) { 2236 debug3("%s: found %s key at %s:%ld", __func__, 2237 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum); 2238 ctx->keys_seen[i] = 1; 2239 return 0; 2240 } 2241 } 2242 /* This line contained a key that not offered by the server */ 2243 debug3("%s: deprecated %s key at %s:%ld", __func__, 2244 sshkey_ssh_name(l->key), l->path, l->linenum); 2245 if ((tmp = reallocarray(ctx->old_keys, ctx->nold + 1, 2246 sizeof(*ctx->old_keys))) == NULL) 2247 fatal("%s: reallocarray failed nold = %zu", 2248 __func__, ctx->nold); 2249 ctx->old_keys = tmp; 2250 ctx->old_keys[ctx->nold++] = l->key; 2251 l->key = NULL; 2252 2253 return 0; 2254 } 2255 2256 static void 2257 update_known_hosts(struct hostkeys_update_ctx *ctx) 2258 { 2259 int r, was_raw = 0; 2260 int loglevel = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK ? 2261 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE; 2262 char *fp, *response; 2263 size_t i; 2264 2265 for (i = 0; i < ctx->nkeys; i++) { 2266 if (ctx->keys_seen[i] != 2) 2267 continue; 2268 if ((fp = sshkey_fingerprint(ctx->keys[i], 2269 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2270 fatal("%s: sshkey_fingerprint failed", __func__); 2271 do_log2(loglevel, "Learned new hostkey: %s %s", 2272 sshkey_type(ctx->keys[i]), fp); 2273 free(fp); 2274 } 2275 for (i = 0; i < ctx->nold; i++) { 2276 if ((fp = sshkey_fingerprint(ctx->old_keys[i], 2277 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2278 fatal("%s: sshkey_fingerprint failed", __func__); 2279 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s", 2280 sshkey_type(ctx->old_keys[i]), fp); 2281 free(fp); 2282 } 2283 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 2284 if (get_saved_tio() != NULL) { 2285 leave_raw_mode(1); 2286 was_raw = 1; 2287 } 2288 response = NULL; 2289 for (i = 0; !quit_pending && i < 3; i++) { 2290 free(response); 2291 response = read_passphrase("Accept updated hostkeys? " 2292 "(yes/no): ", RP_ECHO); 2293 if (strcasecmp(response, "yes") == 0) 2294 break; 2295 else if (quit_pending || response == NULL || 2296 strcasecmp(response, "no") == 0) { 2297 options.update_hostkeys = 0; 2298 break; 2299 } else { 2300 do_log2(loglevel, "Please enter " 2301 "\"yes\" or \"no\""); 2302 } 2303 } 2304 if (quit_pending || i >= 3 || response == NULL) 2305 options.update_hostkeys = 0; 2306 free(response); 2307 if (was_raw) 2308 enter_raw_mode(1); 2309 } 2310 2311 /* 2312 * Now that all the keys are verified, we can go ahead and replace 2313 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't 2314 * cancel the operation). 2315 */ 2316 if (options.update_hostkeys != 0 && 2317 (r = hostfile_replace_entries(options.user_hostfiles[0], 2318 ctx->host_str, ctx->ip_str, ctx->keys, ctx->nkeys, 2319 options.hash_known_hosts, 0, 2320 options.fingerprint_hash)) != 0) 2321 error("%s: hostfile_replace_entries failed: %s", 2322 __func__, ssh_err(r)); 2323 } 2324 2325 static void 2326 client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx) 2327 { 2328 struct ssh *ssh = active_state; /* XXX */ 2329 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2330 size_t i, ndone; 2331 struct sshbuf *signdata; 2332 int r; 2333 const u_char *sig; 2334 size_t siglen; 2335 2336 if (ctx->nnew == 0) 2337 fatal("%s: ctx->nnew == 0", __func__); /* sanity */ 2338 if (type != SSH2_MSG_REQUEST_SUCCESS) { 2339 error("Server failed to confirm ownership of " 2340 "private host keys"); 2341 hostkeys_update_ctx_free(ctx); 2342 return; 2343 } 2344 if ((signdata = sshbuf_new()) == NULL) 2345 fatal("%s: sshbuf_new failed", __func__); 2346 /* Don't want to accidentally accept an unbound signature */ 2347 if (ssh->kex->session_id_len == 0) 2348 fatal("%s: ssh->kex->session_id_len == 0", __func__); 2349 /* 2350 * Expect a signature for each of the ctx->nnew private keys we 2351 * haven't seen before. They will be in the same order as the 2352 * ctx->keys where the corresponding ctx->keys_seen[i] == 0. 2353 */ 2354 for (ndone = i = 0; i < ctx->nkeys; i++) { 2355 if (ctx->keys_seen[i]) 2356 continue; 2357 /* Prepare data to be signed: session ID, unique string, key */ 2358 sshbuf_reset(signdata); 2359 if ( (r = sshbuf_put_cstring(signdata, 2360 "hostkeys-prove-00 (at) openssh.com")) != 0 || 2361 (r = sshbuf_put_string(signdata, ssh->kex->session_id, 2362 ssh->kex->session_id_len)) != 0 || 2363 (r = sshkey_puts(ctx->keys[i], signdata)) != 0) 2364 fatal("%s: failed to prepare signature: %s", 2365 __func__, ssh_err(r)); 2366 /* Extract and verify signature */ 2367 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) { 2368 error("%s: couldn't parse message: %s", 2369 __func__, ssh_err(r)); 2370 goto out; 2371 } 2372 if ((r = sshkey_verify(ctx->keys[i], sig, siglen, 2373 sshbuf_ptr(signdata), sshbuf_len(signdata), 0)) != 0) { 2374 error("%s: server gave bad signature for %s key %zu", 2375 __func__, sshkey_type(ctx->keys[i]), i); 2376 goto out; 2377 } 2378 /* Key is good. Mark it as 'seen' */ 2379 ctx->keys_seen[i] = 2; 2380 ndone++; 2381 } 2382 if (ndone != ctx->nnew) 2383 fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__, 2384 ndone, ctx->nnew); /* Shouldn't happen */ 2385 ssh_packet_check_eom(ssh); 2386 2387 /* Make the edits to known_hosts */ 2388 update_known_hosts(ctx); 2389 out: 2390 hostkeys_update_ctx_free(ctx); 2391 } 2392 2393 /* 2394 * Returns non-zero if the key is accepted by HostkeyAlgorithms. 2395 * Made slightly less trivial by the multiple RSA signature algorithm names. 2396 */ 2397 static int 2398 key_accepted_by_hostkeyalgs(const struct sshkey *key) 2399 { 2400 const char *ktype = sshkey_ssh_name(key); 2401 const char *hostkeyalgs = options.hostkeyalgorithms != NULL ? 2402 options.hostkeyalgorithms : KEX_DEFAULT_PK_ALG; 2403 2404 if (key == NULL || key->type == KEY_UNSPEC) 2405 return 0; 2406 if (key->type == KEY_RSA && 2407 (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 || 2408 match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1)) 2409 return 1; 2410 return match_pattern_list(ktype, hostkeyalgs, 0) == 1; 2411 } 2412 2413 /* 2414 * Handle hostkeys-00 (at) openssh.com global request to inform the client of all 2415 * the server's hostkeys. The keys are checked against the user's 2416 * HostkeyAlgorithms preference before they are accepted. 2417 */ 2418 static int 2419 client_input_hostkeys(void) 2420 { 2421 struct ssh *ssh = active_state; /* XXX */ 2422 const u_char *blob = NULL; 2423 size_t i, len = 0; 2424 struct sshbuf *buf = NULL; 2425 struct sshkey *key = NULL, **tmp; 2426 int r; 2427 char *fp; 2428 static int hostkeys_seen = 0; /* XXX use struct ssh */ 2429 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */ 2430 struct hostkeys_update_ctx *ctx = NULL; 2431 2432 if (hostkeys_seen) 2433 fatal("%s: server already sent hostkeys", __func__); 2434 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK && 2435 options.batch_mode) 2436 return 1; /* won't ask in batchmode, so don't even try */ 2437 if (!options.update_hostkeys || options.num_user_hostfiles <= 0) 2438 return 1; 2439 2440 ctx = xcalloc(1, sizeof(*ctx)); 2441 while (ssh_packet_remaining(ssh) > 0) { 2442 sshkey_free(key); 2443 key = NULL; 2444 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) { 2445 error("%s: couldn't parse message: %s", 2446 __func__, ssh_err(r)); 2447 goto out; 2448 } 2449 if ((r = sshkey_from_blob(blob, len, &key)) != 0) { 2450 error("%s: parse key: %s", __func__, ssh_err(r)); 2451 goto out; 2452 } 2453 fp = sshkey_fingerprint(key, options.fingerprint_hash, 2454 SSH_FP_DEFAULT); 2455 debug3("%s: received %s key %s", __func__, 2456 sshkey_type(key), fp); 2457 free(fp); 2458 2459 if (!key_accepted_by_hostkeyalgs(key)) { 2460 debug3("%s: %s key not permitted by HostkeyAlgorithms", 2461 __func__, sshkey_ssh_name(key)); 2462 continue; 2463 } 2464 /* Skip certs */ 2465 if (sshkey_is_cert(key)) { 2466 debug3("%s: %s key is a certificate; skipping", 2467 __func__, sshkey_ssh_name(key)); 2468 continue; 2469 } 2470 /* Ensure keys are unique */ 2471 for (i = 0; i < ctx->nkeys; i++) { 2472 if (sshkey_equal(key, ctx->keys[i])) { 2473 error("%s: received duplicated %s host key", 2474 __func__, sshkey_ssh_name(key)); 2475 goto out; 2476 } 2477 } 2478 /* Key is good, record it */ 2479 if ((tmp = reallocarray(ctx->keys, ctx->nkeys + 1, 2480 sizeof(*ctx->keys))) == NULL) 2481 fatal("%s: reallocarray failed nkeys = %zu", 2482 __func__, ctx->nkeys); 2483 ctx->keys = tmp; 2484 ctx->keys[ctx->nkeys++] = key; 2485 key = NULL; 2486 } 2487 2488 if (ctx->nkeys == 0) { 2489 debug("%s: server sent no hostkeys", __func__); 2490 goto out; 2491 } 2492 2493 if ((ctx->keys_seen = calloc(ctx->nkeys, 2494 sizeof(*ctx->keys_seen))) == NULL) 2495 fatal("%s: calloc failed", __func__); 2496 2497 get_hostfile_hostname_ipaddr(host, 2498 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL, 2499 options.port, &ctx->host_str, 2500 options.check_host_ip ? &ctx->ip_str : NULL); 2501 2502 /* Find which keys we already know about. */ 2503 if ((r = hostkeys_foreach(options.user_hostfiles[0], hostkeys_find, 2504 ctx, ctx->host_str, ctx->ip_str, 2505 HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) { 2506 error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r)); 2507 goto out; 2508 } 2509 2510 /* Figure out if we have any new keys to add */ 2511 ctx->nnew = 0; 2512 for (i = 0; i < ctx->nkeys; i++) { 2513 if (!ctx->keys_seen[i]) 2514 ctx->nnew++; 2515 } 2516 2517 debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove", 2518 __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold); 2519 2520 if (ctx->nnew == 0 && ctx->nold != 0) { 2521 /* We have some keys to remove. Just do it. */ 2522 update_known_hosts(ctx); 2523 } else if (ctx->nnew != 0) { 2524 /* 2525 * We have received hitherto-unseen keys from the server. 2526 * Ask the server to confirm ownership of the private halves. 2527 */ 2528 debug3("%s: asking server to prove ownership for %zu keys", 2529 __func__, ctx->nnew); 2530 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2531 (r = sshpkt_put_cstring(ssh, 2532 "hostkeys-prove-00 (at) openssh.com")) != 0 || 2533 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */ 2534 fatal("%s: cannot prepare packet: %s", 2535 __func__, ssh_err(r)); 2536 if ((buf = sshbuf_new()) == NULL) 2537 fatal("%s: sshbuf_new", __func__); 2538 for (i = 0; i < ctx->nkeys; i++) { 2539 if (ctx->keys_seen[i]) 2540 continue; 2541 sshbuf_reset(buf); 2542 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0) 2543 fatal("%s: sshkey_putb: %s", 2544 __func__, ssh_err(r)); 2545 if ((r = sshpkt_put_stringb(ssh, buf)) != 0) 2546 fatal("%s: sshpkt_put_string: %s", 2547 __func__, ssh_err(r)); 2548 } 2549 if ((r = sshpkt_send(ssh)) != 0) 2550 fatal("%s: sshpkt_send: %s", __func__, ssh_err(r)); 2551 client_register_global_confirm( 2552 client_global_hostkeys_private_confirm, ctx); 2553 ctx = NULL; /* will be freed in callback */ 2554 } 2555 2556 /* Success */ 2557 out: 2558 hostkeys_update_ctx_free(ctx); 2559 sshkey_free(key); 2560 sshbuf_free(buf); 2561 /* 2562 * NB. Return success for all cases. The server doesn't need to know 2563 * what the client does with its hosts file. 2564 */ 2565 return 1; 2566 } 2567 2568 static int 2569 client_input_global_request(int type, u_int32_t seq, void *ctxt) 2570 { 2571 char *rtype; 2572 int want_reply; 2573 int success = 0; 2574 2575 rtype = packet_get_cstring(NULL); 2576 want_reply = packet_get_char(); 2577 debug("client_input_global_request: rtype %s want_reply %d", 2578 rtype, want_reply); 2579 if (strcmp(rtype, "hostkeys-00 (at) openssh.com") == 0) 2580 success = client_input_hostkeys(); 2581 if (want_reply) { 2582 packet_start(success ? 2583 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 2584 packet_send(); 2585 packet_write_wait(); 2586 } 2587 free(rtype); 2588 return 0; 2589 } 2590 2591 void 2592 client_session2_setup(int id, int want_tty, int want_subsystem, 2593 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 2594 { 2595 int len; 2596 Channel *c = NULL; 2597 2598 debug2("%s: id %d", __func__, id); 2599 2600 if ((c = channel_lookup(id)) == NULL) 2601 fatal("client_session2_setup: channel %d: unknown channel", id); 2602 2603 packet_set_interactive(want_tty, 2604 options.ip_qos_interactive, options.ip_qos_bulk); 2605 2606 if (want_tty) { 2607 struct winsize ws; 2608 2609 /* Store window size in the packet. */ 2610 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 2611 memset(&ws, 0, sizeof(ws)); 2612 2613 channel_request_start(id, "pty-req", 1); 2614 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); 2615 packet_put_cstring(term != NULL ? term : ""); 2616 packet_put_int((u_int)ws.ws_col); 2617 packet_put_int((u_int)ws.ws_row); 2618 packet_put_int((u_int)ws.ws_xpixel); 2619 packet_put_int((u_int)ws.ws_ypixel); 2620 if (tiop == NULL) 2621 tiop = get_saved_tio(); 2622 tty_make_modes(-1, tiop); 2623 packet_send(); 2624 /* XXX wait for reply */ 2625 c->client_tty = 1; 2626 } 2627 2628 /* Transfer any environment variables from client to server */ 2629 if (options.num_send_env != 0 && env != NULL) { 2630 int i, j, matched; 2631 char *name, *val; 2632 2633 debug("Sending environment."); 2634 for (i = 0; env[i] != NULL; i++) { 2635 /* Split */ 2636 name = xstrdup(env[i]); 2637 if ((val = strchr(name, '=')) == NULL) { 2638 free(name); 2639 continue; 2640 } 2641 *val++ = '\0'; 2642 2643 matched = 0; 2644 for (j = 0; j < options.num_send_env; j++) { 2645 if (match_pattern(name, options.send_env[j])) { 2646 matched = 1; 2647 break; 2648 } 2649 } 2650 if (!matched) { 2651 debug3("Ignored env %s", name); 2652 free(name); 2653 continue; 2654 } 2655 2656 debug("Sending env %s = %s", name, val); 2657 channel_request_start(id, "env", 0); 2658 packet_put_cstring(name); 2659 packet_put_cstring(val); 2660 packet_send(); 2661 free(name); 2662 } 2663 } 2664 2665 len = buffer_len(cmd); 2666 if (len > 0) { 2667 if (len > 900) 2668 len = 900; 2669 if (want_subsystem) { 2670 debug("Sending subsystem: %.*s", 2671 len, (u_char*)buffer_ptr(cmd)); 2672 channel_request_start(id, "subsystem", 1); 2673 client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); 2674 } else { 2675 debug("Sending command: %.*s", 2676 len, (u_char*)buffer_ptr(cmd)); 2677 channel_request_start(id, "exec", 1); 2678 client_expect_confirm(id, "exec", CONFIRM_CLOSE); 2679 } 2680 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 2681 packet_send(); 2682 } else { 2683 channel_request_start(id, "shell", 1); 2684 client_expect_confirm(id, "shell", CONFIRM_CLOSE); 2685 packet_send(); 2686 } 2687 } 2688 2689 static void 2690 client_init_dispatch_20(void) 2691 { 2692 dispatch_init(&dispatch_protocol_error); 2693 2694 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2695 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2696 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2697 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2698 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2699 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2700 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2701 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2702 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2703 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2704 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2705 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2706 2707 /* rekeying */ 2708 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2709 2710 /* global request reply messages */ 2711 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2712 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2713 } 2714 2715 static void 2716 client_init_dispatch_13(void) 2717 { 2718 dispatch_init(NULL); 2719 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2720 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2721 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2722 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2723 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2724 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2725 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2726 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2727 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2728 2729 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2730 &client_input_agent_open : &deny_input_open); 2731 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2732 &x11_input_open : &deny_input_open); 2733 } 2734 2735 static void 2736 client_init_dispatch_15(void) 2737 { 2738 client_init_dispatch_13(); 2739 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2740 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2741 } 2742 2743 static void 2744 client_init_dispatch(void) 2745 { 2746 if (compat20) 2747 client_init_dispatch_20(); 2748 else if (compat13) 2749 client_init_dispatch_13(); 2750 else 2751 client_init_dispatch_15(); 2752 } 2753 2754 void 2755 client_stop_mux(void) 2756 { 2757 if (options.control_path != NULL && muxserver_sock != -1) 2758 unlink(options.control_path); 2759 /* 2760 * If we are in persist mode, or don't have a shell, signal that we 2761 * should close when all active channels are closed. 2762 */ 2763 if (options.control_persist || no_shell_flag) { 2764 session_closed = 1; 2765 setproctitle("[stopped mux]"); 2766 } 2767 } 2768 2769 /* client specific fatal cleanup */ 2770 void 2771 cleanup_exit(int i) 2772 { 2773 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2774 leave_non_blocking(); 2775 if (options.control_path != NULL && muxserver_sock != -1) 2776 unlink(options.control_path); 2777 ssh_kill_proxy_command(); 2778 _exit(i); 2779 } 2780
