clientloop.c revision 294693
1/* $OpenBSD: clientloop.c,v 1.258 2014/02/02 03:44:31 djm Exp $ */ 2/* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@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#include <sys/param.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 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 "log.h" 103#include "readconf.h" 104#include "clientloop.h" 105#include "sshconnect.h" 106#include "authfd.h" 107#include "atomicio.h" 108#include "sshpty.h" 109#include "misc.h" 110#include "match.h" 111#include "msg.h" 112#include "roaming.h" 113 114/* import options */ 115extern Options options; 116 117/* Flag indicating that stdin should be redirected from /dev/null. */ 118extern int stdin_null_flag; 119 120/* Flag indicating that no shell has been requested */ 121extern int no_shell_flag; 122 123/* Control socket */ 124extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 125 126/* 127 * Name of the host we are connecting to. This is the name given on the 128 * command line, or the HostName specified for the user-supplied name in a 129 * configuration file. 130 */ 131extern char *host; 132 133/* 134 * Flag to indicate that we have received a window change signal which has 135 * not yet been processed. This will cause a message indicating the new 136 * window size to be sent to the server a little later. This is volatile 137 * because this is updated in a signal handler. 138 */ 139static volatile sig_atomic_t received_window_change_signal = 0; 140static volatile sig_atomic_t received_signal = 0; 141 142/* Flag indicating whether the user's terminal is in non-blocking mode. */ 143static int in_non_blocking_mode = 0; 144 145/* Time when backgrounded control master using ControlPersist should exit */ 146static time_t control_persist_exit_time = 0; 147 148/* Common data for the client loop code. */ 149volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 150static int escape_char1; /* Escape character. (proto1 only) */ 151static int escape_pending1; /* Last character was an escape (proto1 only) */ 152static int last_was_cr; /* Last character was a newline. */ 153static int exit_status; /* Used to store the command exit status. */ 154static int stdin_eof; /* EOF has been encountered on stderr. */ 155static Buffer stdin_buffer; /* Buffer for stdin data. */ 156static Buffer stdout_buffer; /* Buffer for stdout data. */ 157static Buffer stderr_buffer; /* Buffer for stderr data. */ 158static u_int buffer_high; /* Soft max buffer size. */ 159static int connection_in; /* Connection to server (input). */ 160static int connection_out; /* Connection to server (output). */ 161static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 162static int session_closed; /* In SSH2: login session closed. */ 163static int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 164 165static void client_init_dispatch(void); 166int session_ident = -1; 167 168int session_resumed = 0; 169 170/* Track escape per proto2 channel */ 171struct escape_filter_ctx { 172 int escape_pending; 173 int escape_char; 174}; 175 176/* Context for channel confirmation replies */ 177struct channel_reply_ctx { 178 const char *request_type; 179 int id; 180 enum confirm_action action; 181}; 182 183/* Global request success/failure callbacks */ 184struct global_confirm { 185 TAILQ_ENTRY(global_confirm) entry; 186 global_confirm_cb *cb; 187 void *ctx; 188 int ref_count; 189}; 190TAILQ_HEAD(global_confirms, global_confirm); 191static struct global_confirms global_confirms = 192 TAILQ_HEAD_INITIALIZER(global_confirms); 193 194/*XXX*/ 195extern Kex *xxx_kex; 196 197void ssh_process_session2_setup(int, int, int, Buffer *); 198 199/* Restores stdin to blocking mode. */ 200 201static void 202leave_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 212static void 213enter_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 */ 224static void 225window_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 */ 236static void 237signal_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 248static double 249get_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 */ 262static void 263set_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 ":/.-_" 285static int 286client_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" 302void 303client_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(MAXPATHLEN); 345 xauthfile = xmalloc(MAXPATHLEN); 346 mktemp_proto(xauthdir, MAXPATHLEN); 347 if (mkdtemp(xauthdir) != NULL) { 348 do_unlink = 1; 349 snprintf(xauthfile, MAXPATHLEN, "%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 429static void 430client_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 484static void 485client_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 515static void 516client_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 541static void 542client_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; 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} 558 559static void 560server_alive_check(void) 561{ 562 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 563 logit("Timeout, server %s not responding.", host); 564 cleanup_exit(255); 565 } 566 packet_start(SSH2_MSG_GLOBAL_REQUEST); 567 packet_put_cstring("keepalive@openssh.com"); 568 packet_put_char(1); /* boolean: want reply */ 569 packet_send(); 570 /* Insert an empty placeholder to maintain ordering */ 571 client_register_global_confirm(NULL, NULL); 572} 573 574/* 575 * Waits until the client can do something (some data becomes available on 576 * one of the file descriptors). 577 */ 578static void 579client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 580 int *maxfdp, u_int *nallocp, int rekeying) 581{ 582 struct timeval tv, *tvp; 583 int timeout_secs; 584 time_t minwait_secs = 0, server_alive_time = 0, now = monotime(); 585 int ret; 586 587 /* Add any selections by the channel mechanism. */ 588 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 589 &minwait_secs, rekeying); 590 591 if (!compat20) { 592 /* Read from the connection, unless our buffers are full. */ 593 if (buffer_len(&stdout_buffer) < buffer_high && 594 buffer_len(&stderr_buffer) < buffer_high && 595 channel_not_very_much_buffered_data()) 596 FD_SET(connection_in, *readsetp); 597 /* 598 * Read from stdin, unless we have seen EOF or have very much 599 * buffered data to send to the server. 600 */ 601 if (!stdin_eof && packet_not_very_much_data_to_write()) 602 FD_SET(fileno(stdin), *readsetp); 603 604 /* Select stdout/stderr if have data in buffer. */ 605 if (buffer_len(&stdout_buffer) > 0) 606 FD_SET(fileno(stdout), *writesetp); 607 if (buffer_len(&stderr_buffer) > 0) 608 FD_SET(fileno(stderr), *writesetp); 609 } else { 610 /* channel_prepare_select could have closed the last channel */ 611 if (session_closed && !channel_still_open() && 612 !packet_have_data_to_write()) { 613 /* clear mask since we did not call select() */ 614 memset(*readsetp, 0, *nallocp); 615 memset(*writesetp, 0, *nallocp); 616 return; 617 } else { 618 FD_SET(connection_in, *readsetp); 619 } 620 } 621 622 /* Select server connection if have data to write to the server. */ 623 if (packet_have_data_to_write()) 624 FD_SET(connection_out, *writesetp); 625 626 /* 627 * Wait for something to happen. This will suspend the process until 628 * some selected descriptor can be read, written, or has some other 629 * event pending, or a timeout expires. 630 */ 631 632 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 633 if (options.server_alive_interval > 0 && compat20) { 634 timeout_secs = options.server_alive_interval; 635 server_alive_time = now + options.server_alive_interval; 636 } 637 if (options.rekey_interval > 0 && compat20 && !rekeying) 638 timeout_secs = MIN(timeout_secs, packet_get_rekey_timeout()); 639 set_control_persist_exit_time(); 640 if (control_persist_exit_time > 0) { 641 timeout_secs = MIN(timeout_secs, 642 control_persist_exit_time - now); 643 if (timeout_secs < 0) 644 timeout_secs = 0; 645 } 646 if (minwait_secs != 0) 647 timeout_secs = MIN(timeout_secs, (int)minwait_secs); 648 if (timeout_secs == INT_MAX) 649 tvp = NULL; 650 else { 651 tv.tv_sec = timeout_secs; 652 tv.tv_usec = 0; 653 tvp = &tv; 654 } 655 656 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 657 if (ret < 0) { 658 char buf[100]; 659 660 /* 661 * We have to clear the select masks, because we return. 662 * We have to return, because the mainloop checks for the flags 663 * set by the signal handlers. 664 */ 665 memset(*readsetp, 0, *nallocp); 666 memset(*writesetp, 0, *nallocp); 667 668 if (errno == EINTR) 669 return; 670 /* Note: we might still have data in the buffers. */ 671 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 672 buffer_append(&stderr_buffer, buf, strlen(buf)); 673 quit_pending = 1; 674 } else if (ret == 0) { 675 /* 676 * Timeout. Could have been either keepalive or rekeying. 677 * Keepalive we check here, rekeying is checked in clientloop. 678 */ 679 if (server_alive_time != 0 && server_alive_time <= monotime()) 680 server_alive_check(); 681 } 682 683} 684 685static void 686client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 687{ 688 /* Flush stdout and stderr buffers. */ 689 if (buffer_len(bout) > 0) 690 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 691 buffer_len(bout)); 692 if (buffer_len(berr) > 0) 693 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 694 buffer_len(berr)); 695 696 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 697 698 /* 699 * Free (and clear) the buffer to reduce the amount of data that gets 700 * written to swap. 701 */ 702 buffer_free(bin); 703 buffer_free(bout); 704 buffer_free(berr); 705 706 /* Send the suspend signal to the program itself. */ 707 kill(getpid(), SIGTSTP); 708 709 /* Reset window sizes in case they have changed */ 710 received_window_change_signal = 1; 711 712 /* OK, we have been continued by the user. Reinitialize buffers. */ 713 buffer_init(bin); 714 buffer_init(bout); 715 buffer_init(berr); 716 717 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 718} 719 720static void 721client_process_net_input(fd_set *readset) 722{ 723 int len, cont = 0; 724 char buf[SSH_IOBUFSZ]; 725 726 /* 727 * Read input from the server, and add any such data to the buffer of 728 * the packet subsystem. 729 */ 730 if (FD_ISSET(connection_in, readset)) { 731 /* Read as much as possible. */ 732 len = roaming_read(connection_in, buf, sizeof(buf), &cont); 733 if (len == 0 && cont == 0) { 734 /* 735 * Received EOF. The remote host has closed the 736 * connection. 737 */ 738 snprintf(buf, sizeof buf, 739 "Connection to %.300s closed by remote host.\r\n", 740 host); 741 buffer_append(&stderr_buffer, buf, strlen(buf)); 742 quit_pending = 1; 743 return; 744 } 745 /* 746 * There is a kernel bug on Solaris that causes select to 747 * sometimes wake up even though there is no data available. 748 */ 749 if (len < 0 && 750 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 751 len = 0; 752 753 if (len < 0) { 754 /* 755 * An error has encountered. Perhaps there is a 756 * network problem. 757 */ 758 snprintf(buf, sizeof buf, 759 "Read from remote host %.300s: %.100s\r\n", 760 host, strerror(errno)); 761 buffer_append(&stderr_buffer, buf, strlen(buf)); 762 quit_pending = 1; 763 return; 764 } 765 packet_process_incoming(buf, len); 766 } 767} 768 769static void 770client_status_confirm(int type, Channel *c, void *ctx) 771{ 772 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 773 char errmsg[256]; 774 int tochan; 775 776 /* 777 * If a TTY was explicitly requested, then a failure to allocate 778 * one is fatal. 779 */ 780 if (cr->action == CONFIRM_TTY && 781 (options.request_tty == REQUEST_TTY_FORCE || 782 options.request_tty == REQUEST_TTY_YES)) 783 cr->action = CONFIRM_CLOSE; 784 785 /* XXX supress on mux _client_ quietmode */ 786 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 787 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 788 789 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 790 debug2("%s request accepted on channel %d", 791 cr->request_type, c->self); 792 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 793 if (tochan) { 794 snprintf(errmsg, sizeof(errmsg), 795 "%s request failed\r\n", cr->request_type); 796 } else { 797 snprintf(errmsg, sizeof(errmsg), 798 "%s request failed on channel %d", 799 cr->request_type, c->self); 800 } 801 /* If error occurred on primary session channel, then exit */ 802 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 803 fatal("%s", errmsg); 804 /* 805 * If error occurred on mux client, append to 806 * their stderr. 807 */ 808 if (tochan) { 809 buffer_append(&c->extended, errmsg, 810 strlen(errmsg)); 811 } else 812 error("%s", errmsg); 813 if (cr->action == CONFIRM_TTY) { 814 /* 815 * If a TTY allocation error occurred, then arrange 816 * for the correct TTY to leave raw mode. 817 */ 818 if (c->self == session_ident) 819 leave_raw_mode(0); 820 else 821 mux_tty_alloc_failed(c); 822 } else if (cr->action == CONFIRM_CLOSE) { 823 chan_read_failed(c); 824 chan_write_failed(c); 825 } 826 } 827 free(cr); 828} 829 830static void 831client_abandon_status_confirm(Channel *c, void *ctx) 832{ 833 free(ctx); 834} 835 836void 837client_expect_confirm(int id, const char *request, 838 enum confirm_action action) 839{ 840 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 841 842 cr->request_type = request; 843 cr->action = action; 844 845 channel_register_status_confirm(id, client_status_confirm, 846 client_abandon_status_confirm, cr); 847} 848 849void 850client_register_global_confirm(global_confirm_cb *cb, void *ctx) 851{ 852 struct global_confirm *gc, *last_gc; 853 854 /* Coalesce identical callbacks */ 855 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 856 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 857 if (++last_gc->ref_count >= INT_MAX) 858 fatal("%s: last_gc->ref_count = %d", 859 __func__, last_gc->ref_count); 860 return; 861 } 862 863 gc = xcalloc(1, sizeof(*gc)); 864 gc->cb = cb; 865 gc->ctx = ctx; 866 gc->ref_count = 1; 867 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 868} 869 870static void 871process_cmdline(void) 872{ 873 void (*handler)(int); 874 char *s, *cmd, *cancel_host; 875 int delete = 0, local = 0, remote = 0, dynamic = 0; 876 int cancel_port, ok; 877 Forward fwd; 878 879 memset(&fwd, 0, sizeof(fwd)); 880 fwd.listen_host = fwd.connect_host = NULL; 881 882 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 883 handler = signal(SIGINT, SIG_IGN); 884 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 885 if (s == NULL) 886 goto out; 887 while (isspace((u_char)*s)) 888 s++; 889 if (*s == '-') 890 s++; /* Skip cmdline '-', if any */ 891 if (*s == '\0') 892 goto out; 893 894 if (*s == 'h' || *s == 'H' || *s == '?') { 895 logit("Commands:"); 896 logit(" -L[bind_address:]port:host:hostport " 897 "Request local forward"); 898 logit(" -R[bind_address:]port:host:hostport " 899 "Request remote forward"); 900 logit(" -D[bind_address:]port " 901 "Request dynamic forward"); 902 logit(" -KL[bind_address:]port " 903 "Cancel local forward"); 904 logit(" -KR[bind_address:]port " 905 "Cancel remote forward"); 906 logit(" -KD[bind_address:]port " 907 "Cancel dynamic forward"); 908 if (!options.permit_local_command) 909 goto out; 910 logit(" !args " 911 "Execute local command"); 912 goto out; 913 } 914 915 if (*s == '!' && options.permit_local_command) { 916 s++; 917 ssh_local_cmd(s); 918 goto out; 919 } 920 921 if (*s == 'K') { 922 delete = 1; 923 s++; 924 } 925 if (*s == 'L') 926 local = 1; 927 else if (*s == 'R') 928 remote = 1; 929 else if (*s == 'D') 930 dynamic = 1; 931 else { 932 logit("Invalid command."); 933 goto out; 934 } 935 936 if (delete && !compat20) { 937 logit("Not supported for SSH protocol version 1."); 938 goto out; 939 } 940 941 while (isspace((u_char)*++s)) 942 ; 943 944 /* XXX update list of forwards in options */ 945 if (delete) { 946 cancel_port = 0; 947 cancel_host = hpdelim(&s); /* may be NULL */ 948 if (s != NULL) { 949 cancel_port = a2port(s); 950 cancel_host = cleanhostname(cancel_host); 951 } else { 952 cancel_port = a2port(cancel_host); 953 cancel_host = NULL; 954 } 955 if (cancel_port <= 0) { 956 logit("Bad forwarding close port"); 957 goto out; 958 } 959 if (remote) 960 ok = channel_request_rforward_cancel(cancel_host, 961 cancel_port) == 0; 962 else if (dynamic) 963 ok = channel_cancel_lport_listener(cancel_host, 964 cancel_port, 0, options.gateway_ports) > 0; 965 else 966 ok = channel_cancel_lport_listener(cancel_host, 967 cancel_port, CHANNEL_CANCEL_PORT_STATIC, 968 options.gateway_ports) > 0; 969 if (!ok) { 970 logit("Unkown port forwarding."); 971 goto out; 972 } 973 logit("Canceled forwarding."); 974 } else { 975 if (!parse_forward(&fwd, s, dynamic, remote)) { 976 logit("Bad forwarding specification."); 977 goto out; 978 } 979 if (local || dynamic) { 980 if (!channel_setup_local_fwd_listener(fwd.listen_host, 981 fwd.listen_port, fwd.connect_host, 982 fwd.connect_port, options.gateway_ports)) { 983 logit("Port forwarding failed."); 984 goto out; 985 } 986 } else { 987 if (channel_request_remote_forwarding(fwd.listen_host, 988 fwd.listen_port, fwd.connect_host, 989 fwd.connect_port) < 0) { 990 logit("Port forwarding failed."); 991 goto out; 992 } 993 } 994 logit("Forwarding port."); 995 } 996 997out: 998 signal(SIGINT, handler); 999 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1000 free(cmd); 1001 free(fwd.listen_host); 1002 free(fwd.connect_host); 1003} 1004 1005/* reasons to suppress output of an escape command in help output */ 1006#define SUPPRESS_NEVER 0 /* never suppress, always show */ 1007#define SUPPRESS_PROTO1 1 /* don't show in protocol 1 sessions */ 1008#define SUPPRESS_MUXCLIENT 2 /* don't show in mux client sessions */ 1009#define SUPPRESS_MUXMASTER 4 /* don't show in mux master sessions */ 1010#define SUPPRESS_SYSLOG 8 /* don't show when logging to syslog */ 1011struct escape_help_text { 1012 const char *cmd; 1013 const char *text; 1014 unsigned int flags; 1015}; 1016static struct escape_help_text esc_txt[] = { 1017 {".", "terminate session", SUPPRESS_MUXMASTER}, 1018 {".", "terminate connection (and any multiplexed sessions)", 1019 SUPPRESS_MUXCLIENT}, 1020 {"B", "send a BREAK to the remote system", SUPPRESS_PROTO1}, 1021 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 1022 {"R", "request rekey", SUPPRESS_PROTO1}, 1023 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 1024 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 1025 {"#", "list forwarded connections", SUPPRESS_NEVER}, 1026 {"&", "background ssh (when waiting for connections to terminate)", 1027 SUPPRESS_MUXCLIENT}, 1028 {"?", "this message", SUPPRESS_NEVER}, 1029}; 1030 1031static void 1032print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client, 1033 int using_stderr) 1034{ 1035 unsigned int i, suppress_flags; 1036 char string[1024]; 1037 1038 snprintf(string, sizeof string, "%c?\r\n" 1039 "Supported escape sequences:\r\n", escape_char); 1040 buffer_append(b, string, strlen(string)); 1041 1042 suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) | 1043 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 1044 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 1045 (using_stderr ? 0 : SUPPRESS_SYSLOG); 1046 1047 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 1048 if (esc_txt[i].flags & suppress_flags) 1049 continue; 1050 snprintf(string, sizeof string, " %c%-3s - %s\r\n", 1051 escape_char, esc_txt[i].cmd, esc_txt[i].text); 1052 buffer_append(b, string, strlen(string)); 1053 } 1054 1055 snprintf(string, sizeof string, 1056 " %c%c - send the escape character by typing it twice\r\n" 1057 "(Note that escapes are only recognized immediately after " 1058 "newline.)\r\n", escape_char, escape_char); 1059 buffer_append(b, string, strlen(string)); 1060} 1061 1062/* 1063 * Process the characters one by one, call with c==NULL for proto1 case. 1064 */ 1065static int 1066process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 1067 char *buf, int len) 1068{ 1069 char string[1024]; 1070 pid_t pid; 1071 int bytes = 0; 1072 u_int i; 1073 u_char ch; 1074 char *s; 1075 int *escape_pendingp, escape_char; 1076 struct escape_filter_ctx *efc; 1077 1078 if (c == NULL) { 1079 escape_pendingp = &escape_pending1; 1080 escape_char = escape_char1; 1081 } else { 1082 if (c->filter_ctx == NULL) 1083 return 0; 1084 efc = (struct escape_filter_ctx *)c->filter_ctx; 1085 escape_pendingp = &efc->escape_pending; 1086 escape_char = efc->escape_char; 1087 } 1088 1089 if (len <= 0) 1090 return (0); 1091 1092 for (i = 0; i < (u_int)len; i++) { 1093 /* Get one character at a time. */ 1094 ch = buf[i]; 1095 1096 if (*escape_pendingp) { 1097 /* We have previously seen an escape character. */ 1098 /* Clear the flag now. */ 1099 *escape_pendingp = 0; 1100 1101 /* Process the escaped character. */ 1102 switch (ch) { 1103 case '.': 1104 /* Terminate the connection. */ 1105 snprintf(string, sizeof string, "%c.\r\n", 1106 escape_char); 1107 buffer_append(berr, string, strlen(string)); 1108 1109 if (c && c->ctl_chan != -1) { 1110 chan_read_failed(c); 1111 chan_write_failed(c); 1112 if (c->detach_user) 1113 c->detach_user(c->self, NULL); 1114 c->type = SSH_CHANNEL_ABANDONED; 1115 buffer_clear(&c->input); 1116 chan_ibuf_empty(c); 1117 return 0; 1118 } else 1119 quit_pending = 1; 1120 return -1; 1121 1122 case 'Z' - 64: 1123 /* XXX support this for mux clients */ 1124 if (c && c->ctl_chan != -1) { 1125 char b[16]; 1126 noescape: 1127 if (ch == 'Z' - 64) 1128 snprintf(b, sizeof b, "^Z"); 1129 else 1130 snprintf(b, sizeof b, "%c", ch); 1131 snprintf(string, sizeof string, 1132 "%c%s escape not available to " 1133 "multiplexed sessions\r\n", 1134 escape_char, b); 1135 buffer_append(berr, string, 1136 strlen(string)); 1137 continue; 1138 } 1139 /* Suspend the program. Inform the user */ 1140 snprintf(string, sizeof string, 1141 "%c^Z [suspend ssh]\r\n", escape_char); 1142 buffer_append(berr, string, strlen(string)); 1143 1144 /* Restore terminal modes and suspend. */ 1145 client_suspend_self(bin, bout, berr); 1146 1147 /* We have been continued. */ 1148 continue; 1149 1150 case 'B': 1151 if (compat20) { 1152 snprintf(string, sizeof string, 1153 "%cB\r\n", escape_char); 1154 buffer_append(berr, string, 1155 strlen(string)); 1156 channel_request_start(c->self, 1157 "break", 0); 1158 packet_put_int(1000); 1159 packet_send(); 1160 } 1161 continue; 1162 1163 case 'R': 1164 if (compat20) { 1165 if (datafellows & SSH_BUG_NOREKEY) 1166 logit("Server does not " 1167 "support re-keying"); 1168 else 1169 need_rekeying = 1; 1170 } 1171 continue; 1172 1173 case 'V': 1174 /* FALLTHROUGH */ 1175 case 'v': 1176 if (c && c->ctl_chan != -1) 1177 goto noescape; 1178 if (!log_is_on_stderr()) { 1179 snprintf(string, sizeof string, 1180 "%c%c [Logging to syslog]\r\n", 1181 escape_char, ch); 1182 buffer_append(berr, string, 1183 strlen(string)); 1184 continue; 1185 } 1186 if (ch == 'V' && options.log_level > 1187 SYSLOG_LEVEL_QUIET) 1188 log_change_level(--options.log_level); 1189 if (ch == 'v' && options.log_level < 1190 SYSLOG_LEVEL_DEBUG3) 1191 log_change_level(++options.log_level); 1192 snprintf(string, sizeof string, 1193 "%c%c [LogLevel %s]\r\n", escape_char, ch, 1194 log_level_name(options.log_level)); 1195 buffer_append(berr, string, strlen(string)); 1196 continue; 1197 1198 case '&': 1199 if (c && c->ctl_chan != -1) 1200 goto noescape; 1201 /* 1202 * Detach the program (continue to serve 1203 * connections, but put in background and no 1204 * more new connections). 1205 */ 1206 /* Restore tty modes. */ 1207 leave_raw_mode( 1208 options.request_tty == REQUEST_TTY_FORCE); 1209 1210 /* Stop listening for new connections. */ 1211 channel_stop_listening(); 1212 1213 snprintf(string, sizeof string, 1214 "%c& [backgrounded]\n", escape_char); 1215 buffer_append(berr, string, strlen(string)); 1216 1217 /* Fork into background. */ 1218 pid = fork(); 1219 if (pid < 0) { 1220 error("fork: %.100s", strerror(errno)); 1221 continue; 1222 } 1223 if (pid != 0) { /* This is the parent. */ 1224 /* The parent just exits. */ 1225 exit(0); 1226 } 1227 /* The child continues serving connections. */ 1228 if (compat20) { 1229 buffer_append(bin, "\004", 1); 1230 /* fake EOF on stdin */ 1231 return -1; 1232 } else if (!stdin_eof) { 1233 /* 1234 * Sending SSH_CMSG_EOF alone does not 1235 * always appear to be enough. So we 1236 * try to send an EOF character first. 1237 */ 1238 packet_start(SSH_CMSG_STDIN_DATA); 1239 packet_put_string("\004", 1); 1240 packet_send(); 1241 /* Close stdin. */ 1242 stdin_eof = 1; 1243 if (buffer_len(bin) == 0) { 1244 packet_start(SSH_CMSG_EOF); 1245 packet_send(); 1246 } 1247 } 1248 continue; 1249 1250 case '?': 1251 print_escape_help(berr, escape_char, compat20, 1252 (c && c->ctl_chan != -1), 1253 log_is_on_stderr()); 1254 continue; 1255 1256 case '#': 1257 snprintf(string, sizeof string, "%c#\r\n", 1258 escape_char); 1259 buffer_append(berr, string, strlen(string)); 1260 s = channel_open_message(); 1261 buffer_append(berr, s, strlen(s)); 1262 free(s); 1263 continue; 1264 1265 case 'C': 1266 if (c && c->ctl_chan != -1) 1267 goto noescape; 1268 process_cmdline(); 1269 continue; 1270 1271 default: 1272 if (ch != escape_char) { 1273 buffer_put_char(bin, escape_char); 1274 bytes++; 1275 } 1276 /* Escaped characters fall through here */ 1277 break; 1278 } 1279 } else { 1280 /* 1281 * The previous character was not an escape char. 1282 * Check if this is an escape. 1283 */ 1284 if (last_was_cr && ch == escape_char) { 1285 /* 1286 * It is. Set the flag and continue to 1287 * next character. 1288 */ 1289 *escape_pendingp = 1; 1290 continue; 1291 } 1292 } 1293 1294 /* 1295 * Normal character. Record whether it was a newline, 1296 * and append it to the buffer. 1297 */ 1298 last_was_cr = (ch == '\r' || ch == '\n'); 1299 buffer_put_char(bin, ch); 1300 bytes++; 1301 } 1302 return bytes; 1303} 1304 1305static void 1306client_process_input(fd_set *readset) 1307{ 1308 int len; 1309 char buf[SSH_IOBUFSZ]; 1310 1311 /* Read input from stdin. */ 1312 if (FD_ISSET(fileno(stdin), readset)) { 1313 /* Read as much as possible. */ 1314 len = read(fileno(stdin), buf, sizeof(buf)); 1315 if (len < 0 && 1316 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1317 return; /* we'll try again later */ 1318 if (len <= 0) { 1319 /* 1320 * Received EOF or error. They are treated 1321 * similarly, except that an error message is printed 1322 * if it was an error condition. 1323 */ 1324 if (len < 0) { 1325 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1326 strerror(errno)); 1327 buffer_append(&stderr_buffer, buf, strlen(buf)); 1328 } 1329 /* Mark that we have seen EOF. */ 1330 stdin_eof = 1; 1331 /* 1332 * Send an EOF message to the server unless there is 1333 * data in the buffer. If there is data in the 1334 * buffer, no message will be sent now. Code 1335 * elsewhere will send the EOF when the buffer 1336 * becomes empty if stdin_eof is set. 1337 */ 1338 if (buffer_len(&stdin_buffer) == 0) { 1339 packet_start(SSH_CMSG_EOF); 1340 packet_send(); 1341 } 1342 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1343 /* 1344 * Normal successful read, and no escape character. 1345 * Just append the data to buffer. 1346 */ 1347 buffer_append(&stdin_buffer, buf, len); 1348 } else { 1349 /* 1350 * Normal, successful read. But we have an escape 1351 * character and have to process the characters one 1352 * by one. 1353 */ 1354 if (process_escapes(NULL, &stdin_buffer, 1355 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1356 return; 1357 } 1358 } 1359} 1360 1361static void 1362client_process_output(fd_set *writeset) 1363{ 1364 int len; 1365 char buf[100]; 1366 1367 /* Write buffered output to stdout. */ 1368 if (FD_ISSET(fileno(stdout), writeset)) { 1369 /* Write as much data as possible. */ 1370 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1371 buffer_len(&stdout_buffer)); 1372 if (len <= 0) { 1373 if (errno == EINTR || errno == EAGAIN || 1374 errno == EWOULDBLOCK) 1375 len = 0; 1376 else { 1377 /* 1378 * An error or EOF was encountered. Put an 1379 * error message to stderr buffer. 1380 */ 1381 snprintf(buf, sizeof buf, 1382 "write stdout: %.50s\r\n", strerror(errno)); 1383 buffer_append(&stderr_buffer, buf, strlen(buf)); 1384 quit_pending = 1; 1385 return; 1386 } 1387 } 1388 /* Consume printed data from the buffer. */ 1389 buffer_consume(&stdout_buffer, len); 1390 } 1391 /* Write buffered output to stderr. */ 1392 if (FD_ISSET(fileno(stderr), writeset)) { 1393 /* Write as much data as possible. */ 1394 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1395 buffer_len(&stderr_buffer)); 1396 if (len <= 0) { 1397 if (errno == EINTR || errno == EAGAIN || 1398 errno == EWOULDBLOCK) 1399 len = 0; 1400 else { 1401 /* 1402 * EOF or error, but can't even print 1403 * error message. 1404 */ 1405 quit_pending = 1; 1406 return; 1407 } 1408 } 1409 /* Consume printed characters from the buffer. */ 1410 buffer_consume(&stderr_buffer, len); 1411 } 1412} 1413 1414/* 1415 * Get packets from the connection input buffer, and process them as long as 1416 * there are packets available. 1417 * 1418 * Any unknown packets received during the actual 1419 * session cause the session to terminate. This is 1420 * intended to make debugging easier since no 1421 * confirmations are sent. Any compatible protocol 1422 * extensions must be negotiated during the 1423 * preparatory phase. 1424 */ 1425 1426static void 1427client_process_buffered_input_packets(void) 1428{ 1429 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1430 compat20 ? xxx_kex : NULL); 1431} 1432 1433/* scan buf[] for '~' before sending data to the peer */ 1434 1435/* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1436void * 1437client_new_escape_filter_ctx(int escape_char) 1438{ 1439 struct escape_filter_ctx *ret; 1440 1441 ret = xcalloc(1, sizeof(*ret)); 1442 ret->escape_pending = 0; 1443 ret->escape_char = escape_char; 1444 return (void *)ret; 1445} 1446 1447/* Free the escape filter context on channel free */ 1448void 1449client_filter_cleanup(int cid, void *ctx) 1450{ 1451 free(ctx); 1452} 1453 1454int 1455client_simple_escape_filter(Channel *c, char *buf, int len) 1456{ 1457 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1458 return 0; 1459 1460 return process_escapes(c, &c->input, &c->output, &c->extended, 1461 buf, len); 1462} 1463 1464static void 1465client_channel_closed(int id, void *arg) 1466{ 1467 channel_cancel_cleanup(id); 1468 session_closed = 1; 1469 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1470} 1471 1472/* 1473 * Implements the interactive session with the server. This is called after 1474 * the user has been authenticated, and a command has been started on the 1475 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1476 * used as an escape character for terminating or suspending the session. 1477 */ 1478 1479int 1480client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1481{ 1482 fd_set *readset = NULL, *writeset = NULL; 1483 double start_time, total_time; 1484 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1485 u_int64_t ibytes, obytes; 1486 u_int nalloc = 0; 1487 char buf[100]; 1488 1489 debug("Entering interactive session."); 1490 1491 start_time = get_current_time(); 1492 1493 /* Initialize variables. */ 1494 escape_pending1 = 0; 1495 last_was_cr = 1; 1496 exit_status = -1; 1497 stdin_eof = 0; 1498 buffer_high = 64 * 1024; 1499 connection_in = packet_get_connection_in(); 1500 connection_out = packet_get_connection_out(); 1501 max_fd = MAX(connection_in, connection_out); 1502 1503 if (!compat20) { 1504 /* enable nonblocking unless tty */ 1505 if (!isatty(fileno(stdin))) 1506 set_nonblock(fileno(stdin)); 1507 if (!isatty(fileno(stdout))) 1508 set_nonblock(fileno(stdout)); 1509 if (!isatty(fileno(stderr))) 1510 set_nonblock(fileno(stderr)); 1511 max_fd = MAX(max_fd, fileno(stdin)); 1512 max_fd = MAX(max_fd, fileno(stdout)); 1513 max_fd = MAX(max_fd, fileno(stderr)); 1514 } 1515 quit_pending = 0; 1516 escape_char1 = escape_char_arg; 1517 1518 /* Initialize buffers. */ 1519 buffer_init(&stdin_buffer); 1520 buffer_init(&stdout_buffer); 1521 buffer_init(&stderr_buffer); 1522 1523 client_init_dispatch(); 1524 1525 /* 1526 * Set signal handlers, (e.g. to restore non-blocking mode) 1527 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1528 */ 1529 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1530 signal(SIGHUP, signal_handler); 1531 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1532 signal(SIGINT, signal_handler); 1533 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1534 signal(SIGQUIT, signal_handler); 1535 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1536 signal(SIGTERM, signal_handler); 1537 signal(SIGWINCH, window_change_handler); 1538 1539 if (have_pty) 1540 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1541 1542 if (compat20) { 1543 session_ident = ssh2_chan_id; 1544 if (session_ident != -1) { 1545 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1546 channel_register_filter(session_ident, 1547 client_simple_escape_filter, NULL, 1548 client_filter_cleanup, 1549 client_new_escape_filter_ctx( 1550 escape_char_arg)); 1551 } 1552 channel_register_cleanup(session_ident, 1553 client_channel_closed, 0); 1554 } 1555 } else { 1556 /* Check if we should immediately send eof on stdin. */ 1557 client_check_initial_eof_on_stdin(); 1558 } 1559 1560 /* Main loop of the client for the interactive session mode. */ 1561 while (!quit_pending) { 1562 1563 /* Process buffered packets sent by the server. */ 1564 client_process_buffered_input_packets(); 1565 1566 if (compat20 && session_closed && !channel_still_open()) 1567 break; 1568 1569 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1570 1571 if (rekeying) { 1572 debug("rekeying in progress"); 1573 } else { 1574 /* 1575 * Make packets of buffered stdin data, and buffer 1576 * them for sending to the server. 1577 */ 1578 if (!compat20) 1579 client_make_packets_from_stdin_data(); 1580 1581 /* 1582 * Make packets from buffered channel data, and 1583 * enqueue them for sending to the server. 1584 */ 1585 if (packet_not_very_much_data_to_write()) 1586 channel_output_poll(); 1587 1588 /* 1589 * Check if the window size has changed, and buffer a 1590 * message about it to the server if so. 1591 */ 1592 client_check_window_change(); 1593 1594 if (quit_pending) 1595 break; 1596 } 1597 /* 1598 * Wait until we have something to do (something becomes 1599 * available on one of the descriptors). 1600 */ 1601 max_fd2 = max_fd; 1602 client_wait_until_can_do_something(&readset, &writeset, 1603 &max_fd2, &nalloc, rekeying); 1604 1605 if (quit_pending) 1606 break; 1607 1608 /* Do channel operations unless rekeying in progress. */ 1609 if (!rekeying) { 1610 channel_after_select(readset, writeset); 1611 if (need_rekeying || packet_need_rekeying()) { 1612 debug("need rekeying"); 1613 xxx_kex->done = 0; 1614 kex_send_kexinit(xxx_kex); 1615 need_rekeying = 0; 1616 } 1617 } 1618 1619 /* Buffer input from the connection. */ 1620 client_process_net_input(readset); 1621 1622 if (quit_pending) 1623 break; 1624 1625 if (!compat20) { 1626 /* Buffer data from stdin */ 1627 client_process_input(readset); 1628 /* 1629 * Process output to stdout and stderr. Output to 1630 * the connection is processed elsewhere (above). 1631 */ 1632 client_process_output(writeset); 1633 } 1634 1635 if (session_resumed) { 1636 connection_in = packet_get_connection_in(); 1637 connection_out = packet_get_connection_out(); 1638 max_fd = MAX(max_fd, connection_out); 1639 max_fd = MAX(max_fd, connection_in); 1640 session_resumed = 0; 1641 } 1642 1643 /* 1644 * Send as much buffered packet data as possible to the 1645 * sender. 1646 */ 1647 if (FD_ISSET(connection_out, writeset)) 1648 packet_write_poll(); 1649 1650 /* 1651 * If we are a backgrounded control master, and the 1652 * timeout has expired without any active client 1653 * connections, then quit. 1654 */ 1655 if (control_persist_exit_time > 0) { 1656 if (monotime() >= control_persist_exit_time) { 1657 debug("ControlPersist timeout expired"); 1658 break; 1659 } 1660 } 1661 } 1662 free(readset); 1663 free(writeset); 1664 1665 /* Terminate the session. */ 1666 1667 /* Stop watching for window change. */ 1668 signal(SIGWINCH, SIG_DFL); 1669 1670 if (compat20) { 1671 packet_start(SSH2_MSG_DISCONNECT); 1672 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1673 packet_put_cstring("disconnected by user"); 1674 packet_put_cstring(""); /* language tag */ 1675 packet_send(); 1676 packet_write_wait(); 1677 } 1678 1679 channel_free_all(); 1680 1681 if (have_pty) 1682 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1683 1684 /* restore blocking io */ 1685 if (!isatty(fileno(stdin))) 1686 unset_nonblock(fileno(stdin)); 1687 if (!isatty(fileno(stdout))) 1688 unset_nonblock(fileno(stdout)); 1689 if (!isatty(fileno(stderr))) 1690 unset_nonblock(fileno(stderr)); 1691 1692 /* 1693 * If there was no shell or command requested, there will be no remote 1694 * exit status to be returned. In that case, clear error code if the 1695 * connection was deliberately terminated at this end. 1696 */ 1697 if (no_shell_flag && received_signal == SIGTERM) { 1698 received_signal = 0; 1699 exit_status = 0; 1700 } 1701 1702 if (received_signal) 1703 fatal("Killed by signal %d.", (int) received_signal); 1704 1705 /* 1706 * In interactive mode (with pseudo tty) display a message indicating 1707 * that the connection has been closed. 1708 */ 1709 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1710 snprintf(buf, sizeof buf, 1711 "Connection to %.64s closed.\r\n", host); 1712 buffer_append(&stderr_buffer, buf, strlen(buf)); 1713 } 1714 1715 /* Output any buffered data for stdout. */ 1716 if (buffer_len(&stdout_buffer) > 0) { 1717 len = atomicio(vwrite, fileno(stdout), 1718 buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer)); 1719 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer)) 1720 error("Write failed flushing stdout buffer."); 1721 else 1722 buffer_consume(&stdout_buffer, len); 1723 } 1724 1725 /* Output any buffered data for stderr. */ 1726 if (buffer_len(&stderr_buffer) > 0) { 1727 len = atomicio(vwrite, fileno(stderr), 1728 buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer)); 1729 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer)) 1730 error("Write failed flushing stderr buffer."); 1731 else 1732 buffer_consume(&stderr_buffer, len); 1733 } 1734 1735 /* Clear and free any buffers. */ 1736 memset(buf, 0, sizeof(buf)); 1737 buffer_free(&stdin_buffer); 1738 buffer_free(&stdout_buffer); 1739 buffer_free(&stderr_buffer); 1740 1741 /* Report bytes transferred, and transfer rates. */ 1742 total_time = get_current_time() - start_time; 1743 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1744 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1745 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1746 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1747 if (total_time > 0) 1748 verbose("Bytes per second: sent %.1f, received %.1f", 1749 obytes / total_time, ibytes / total_time); 1750 /* Return the exit status of the program. */ 1751 debug("Exit status %d", exit_status); 1752 return exit_status; 1753} 1754 1755/*********/ 1756 1757static void 1758client_input_stdout_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(&stdout_buffer, data, data_len); 1764 explicit_bzero(data, data_len); 1765 free(data); 1766} 1767static void 1768client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1769{ 1770 u_int data_len; 1771 char *data = packet_get_string(&data_len); 1772 packet_check_eom(); 1773 buffer_append(&stderr_buffer, data, data_len); 1774 explicit_bzero(data, data_len); 1775 free(data); 1776} 1777static void 1778client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1779{ 1780 exit_status = packet_get_int(); 1781 packet_check_eom(); 1782 /* Acknowledge the exit. */ 1783 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1784 packet_send(); 1785 /* 1786 * Must wait for packet to be sent since we are 1787 * exiting the loop. 1788 */ 1789 packet_write_wait(); 1790 /* Flag that we want to exit. */ 1791 quit_pending = 1; 1792} 1793static void 1794client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1795{ 1796 Channel *c = NULL; 1797 int remote_id, sock; 1798 1799 /* Read the remote channel number from the message. */ 1800 remote_id = packet_get_int(); 1801 packet_check_eom(); 1802 1803 /* 1804 * Get a connection to the local authentication agent (this may again 1805 * get forwarded). 1806 */ 1807 sock = ssh_get_authentication_socket(); 1808 1809 /* 1810 * If we could not connect the agent, send an error message back to 1811 * the server. This should never happen unless the agent dies, 1812 * because authentication forwarding is only enabled if we have an 1813 * agent. 1814 */ 1815 if (sock >= 0) { 1816 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1817 -1, 0, 0, 0, "authentication agent connection", 1); 1818 c->remote_id = remote_id; 1819 c->force_drain = 1; 1820 } 1821 if (c == NULL) { 1822 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1823 packet_put_int(remote_id); 1824 } else { 1825 /* Send a confirmation to the remote host. */ 1826 debug("Forwarding authentication connection."); 1827 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1828 packet_put_int(remote_id); 1829 packet_put_int(c->self); 1830 } 1831 packet_send(); 1832} 1833 1834static Channel * 1835client_request_forwarded_tcpip(const char *request_type, int rchan) 1836{ 1837 Channel *c = NULL; 1838 char *listen_address, *originator_address; 1839 u_short listen_port, originator_port; 1840 1841 /* Get rest of the packet */ 1842 listen_address = packet_get_string(NULL); 1843 listen_port = packet_get_int(); 1844 originator_address = packet_get_string(NULL); 1845 originator_port = packet_get_int(); 1846 packet_check_eom(); 1847 1848 debug("client_request_forwarded_tcpip: listen %s port %d, " 1849 "originator %s port %d", listen_address, listen_port, 1850 originator_address, originator_port); 1851 1852 c = channel_connect_by_listen_address(listen_port, 1853 "forwarded-tcpip", originator_address); 1854 1855 free(originator_address); 1856 free(listen_address); 1857 return c; 1858} 1859 1860static Channel * 1861client_request_x11(const char *request_type, int rchan) 1862{ 1863 Channel *c = NULL; 1864 char *originator; 1865 u_short originator_port; 1866 int sock; 1867 1868 if (!options.forward_x11) { 1869 error("Warning: ssh server tried X11 forwarding."); 1870 error("Warning: this is probably a break-in attempt by a " 1871 "malicious server."); 1872 return NULL; 1873 } 1874 if (x11_refuse_time != 0 && monotime() >= x11_refuse_time) { 1875 verbose("Rejected X11 connection after ForwardX11Timeout " 1876 "expired"); 1877 return NULL; 1878 } 1879 originator = packet_get_string(NULL); 1880 if (datafellows & SSH_BUG_X11FWD) { 1881 debug2("buggy server: x11 request w/o originator_port"); 1882 originator_port = 0; 1883 } else { 1884 originator_port = packet_get_int(); 1885 } 1886 packet_check_eom(); 1887 /* XXX check permission */ 1888 debug("client_request_x11: request from %s %d", originator, 1889 originator_port); 1890 free(originator); 1891 sock = x11_connect_display(); 1892 if (sock < 0) 1893 return NULL; 1894 c = channel_new("x11", 1895 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1896 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1897 c->force_drain = 1; 1898 return c; 1899} 1900 1901static Channel * 1902client_request_agent(const char *request_type, int rchan) 1903{ 1904 Channel *c = NULL; 1905 int sock; 1906 1907 if (!options.forward_agent) { 1908 error("Warning: ssh server tried agent forwarding."); 1909 error("Warning: this is probably a break-in attempt by a " 1910 "malicious server."); 1911 return NULL; 1912 } 1913 sock = ssh_get_authentication_socket(); 1914 if (sock < 0) 1915 return NULL; 1916 c = channel_new("authentication agent connection", 1917 SSH_CHANNEL_OPEN, sock, sock, -1, 1918 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1919 "authentication agent connection", 1); 1920 c->force_drain = 1; 1921 return c; 1922} 1923 1924int 1925client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1926{ 1927 Channel *c; 1928 int fd; 1929 1930 if (tun_mode == SSH_TUNMODE_NO) 1931 return 0; 1932 1933 if (!compat20) { 1934 error("Tunnel forwarding is not supported for protocol 1"); 1935 return -1; 1936 } 1937 1938 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1939 1940 /* Open local tunnel device */ 1941 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1942 error("Tunnel device open failed."); 1943 return -1; 1944 } 1945 1946 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1947 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1948 c->datagram = 1; 1949 1950#if defined(SSH_TUN_FILTER) 1951 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1952 channel_register_filter(c->self, sys_tun_infilter, 1953 sys_tun_outfilter, NULL, NULL); 1954#endif 1955 1956 packet_start(SSH2_MSG_CHANNEL_OPEN); 1957 packet_put_cstring("tun@openssh.com"); 1958 packet_put_int(c->self); 1959 packet_put_int(c->local_window_max); 1960 packet_put_int(c->local_maxpacket); 1961 packet_put_int(tun_mode); 1962 packet_put_int(remote_tun); 1963 packet_send(); 1964 1965 return 0; 1966} 1967 1968/* XXXX move to generic input handler */ 1969static void 1970client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1971{ 1972 Channel *c = NULL; 1973 char *ctype; 1974 int rchan; 1975 u_int rmaxpack, rwindow, len; 1976 1977 ctype = packet_get_string(&len); 1978 rchan = packet_get_int(); 1979 rwindow = packet_get_int(); 1980 rmaxpack = packet_get_int(); 1981 1982 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1983 ctype, rchan, rwindow, rmaxpack); 1984 1985 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1986 c = client_request_forwarded_tcpip(ctype, rchan); 1987 } else if (strcmp(ctype, "x11") == 0) { 1988 c = client_request_x11(ctype, rchan); 1989 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1990 c = client_request_agent(ctype, rchan); 1991 } 1992/* XXX duplicate : */ 1993 if (c != NULL) { 1994 debug("confirm %s", ctype); 1995 c->remote_id = rchan; 1996 c->remote_window = rwindow; 1997 c->remote_maxpacket = rmaxpack; 1998 if (c->type != SSH_CHANNEL_CONNECTING) { 1999 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 2000 packet_put_int(c->remote_id); 2001 packet_put_int(c->self); 2002 packet_put_int(c->local_window); 2003 packet_put_int(c->local_maxpacket); 2004 packet_send(); 2005 } 2006 } else { 2007 debug("failure %s", ctype); 2008 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 2009 packet_put_int(rchan); 2010 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 2011 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 2012 packet_put_cstring("open failed"); 2013 packet_put_cstring(""); 2014 } 2015 packet_send(); 2016 } 2017 free(ctype); 2018} 2019static void 2020client_input_channel_req(int type, u_int32_t seq, void *ctxt) 2021{ 2022 Channel *c = NULL; 2023 int exitval, id, reply, success = 0; 2024 char *rtype; 2025 2026 id = packet_get_int(); 2027 rtype = packet_get_string(NULL); 2028 reply = packet_get_char(); 2029 2030 debug("client_input_channel_req: channel %d rtype %s reply %d", 2031 id, rtype, reply); 2032 2033 if (id == -1) { 2034 error("client_input_channel_req: request for channel -1"); 2035 } else if ((c = channel_lookup(id)) == NULL) { 2036 error("client_input_channel_req: channel %d: " 2037 "unknown channel", id); 2038 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 2039 packet_check_eom(); 2040 chan_rcvd_eow(c); 2041 } else if (strcmp(rtype, "exit-status") == 0) { 2042 exitval = packet_get_int(); 2043 if (c->ctl_chan != -1) { 2044 mux_exit_message(c, exitval); 2045 success = 1; 2046 } else if (id == session_ident) { 2047 /* Record exit value of local session */ 2048 success = 1; 2049 exit_status = exitval; 2050 } else { 2051 /* Probably for a mux channel that has already closed */ 2052 debug("%s: no sink for exit-status on channel %d", 2053 __func__, id); 2054 } 2055 packet_check_eom(); 2056 } 2057 if (reply && c != NULL) { 2058 packet_start(success ? 2059 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 2060 packet_put_int(c->remote_id); 2061 packet_send(); 2062 } 2063 free(rtype); 2064} 2065static void 2066client_input_global_request(int type, u_int32_t seq, void *ctxt) 2067{ 2068 char *rtype; 2069 int want_reply; 2070 int success = 0; 2071 2072 rtype = packet_get_string(NULL); 2073 want_reply = packet_get_char(); 2074 debug("client_input_global_request: rtype %s want_reply %d", 2075 rtype, want_reply); 2076 if (want_reply) { 2077 packet_start(success ? 2078 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 2079 packet_send(); 2080 packet_write_wait(); 2081 } 2082 free(rtype); 2083} 2084 2085void 2086client_session2_setup(int id, int want_tty, int want_subsystem, 2087 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 2088{ 2089 int len; 2090 Channel *c = NULL; 2091 2092 debug2("%s: id %d", __func__, id); 2093 2094 if ((c = channel_lookup(id)) == NULL) 2095 fatal("client_session2_setup: channel %d: unknown channel", id); 2096 2097 packet_set_interactive(want_tty, 2098 options.ip_qos_interactive, options.ip_qos_bulk); 2099 2100 if (want_tty) { 2101 struct winsize ws; 2102 2103 /* Store window size in the packet. */ 2104 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 2105 memset(&ws, 0, sizeof(ws)); 2106 2107 channel_request_start(id, "pty-req", 1); 2108 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); 2109 packet_put_cstring(term != NULL ? term : ""); 2110 packet_put_int((u_int)ws.ws_col); 2111 packet_put_int((u_int)ws.ws_row); 2112 packet_put_int((u_int)ws.ws_xpixel); 2113 packet_put_int((u_int)ws.ws_ypixel); 2114 if (tiop == NULL) 2115 tiop = get_saved_tio(); 2116 tty_make_modes(-1, tiop); 2117 packet_send(); 2118 /* XXX wait for reply */ 2119 c->client_tty = 1; 2120 } 2121 2122 /* Transfer any environment variables from client to server */ 2123 if (options.num_send_env != 0 && env != NULL) { 2124 int i, j, matched; 2125 char *name, *val; 2126 2127 debug("Sending environment."); 2128 for (i = 0; env[i] != NULL; i++) { 2129 /* Split */ 2130 name = xstrdup(env[i]); 2131 if ((val = strchr(name, '=')) == NULL) { 2132 free(name); 2133 continue; 2134 } 2135 *val++ = '\0'; 2136 2137 matched = 0; 2138 for (j = 0; j < options.num_send_env; j++) { 2139 if (match_pattern(name, options.send_env[j])) { 2140 matched = 1; 2141 break; 2142 } 2143 } 2144 if (!matched) { 2145 debug3("Ignored env %s", name); 2146 free(name); 2147 continue; 2148 } 2149 2150 debug("Sending env %s = %s", name, val); 2151 channel_request_start(id, "env", 0); 2152 packet_put_cstring(name); 2153 packet_put_cstring(val); 2154 packet_send(); 2155 free(name); 2156 } 2157 } 2158 2159 len = buffer_len(cmd); 2160 if (len > 0) { 2161 if (len > 900) 2162 len = 900; 2163 if (want_subsystem) { 2164 debug("Sending subsystem: %.*s", 2165 len, (u_char*)buffer_ptr(cmd)); 2166 channel_request_start(id, "subsystem", 1); 2167 client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); 2168 } else { 2169 debug("Sending command: %.*s", 2170 len, (u_char*)buffer_ptr(cmd)); 2171 channel_request_start(id, "exec", 1); 2172 client_expect_confirm(id, "exec", CONFIRM_CLOSE); 2173 } 2174 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 2175 packet_send(); 2176 } else { 2177 channel_request_start(id, "shell", 1); 2178 client_expect_confirm(id, "shell", CONFIRM_CLOSE); 2179 packet_send(); 2180 } 2181} 2182 2183static void 2184client_init_dispatch_20(void) 2185{ 2186 dispatch_init(&dispatch_protocol_error); 2187 2188 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2189 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2190 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2191 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2192 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2193 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2194 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2195 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2196 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2197 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2198 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2199 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2200 2201 /* rekeying */ 2202 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2203 2204 /* global request reply messages */ 2205 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2206 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2207} 2208 2209static void 2210client_init_dispatch_13(void) 2211{ 2212 dispatch_init(NULL); 2213 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2214 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2215 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2216 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2217 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2218 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2219 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2220 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2221 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2222 2223 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2224 &client_input_agent_open : &deny_input_open); 2225 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2226 &x11_input_open : &deny_input_open); 2227} 2228 2229static void 2230client_init_dispatch_15(void) 2231{ 2232 client_init_dispatch_13(); 2233 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2234 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2235} 2236 2237static void 2238client_init_dispatch(void) 2239{ 2240 if (compat20) 2241 client_init_dispatch_20(); 2242 else if (compat13) 2243 client_init_dispatch_13(); 2244 else 2245 client_init_dispatch_15(); 2246} 2247 2248void 2249client_stop_mux(void) 2250{ 2251 if (options.control_path != NULL && muxserver_sock != -1) 2252 unlink(options.control_path); 2253 /* 2254 * If we are in persist mode, or don't have a shell, signal that we 2255 * should close when all active channels are closed. 2256 */ 2257 if (options.control_persist || no_shell_flag) { 2258 session_closed = 1; 2259 setproctitle("[stopped mux]"); 2260 } 2261} 2262 2263/* client specific fatal cleanup */ 2264void 2265cleanup_exit(int i) 2266{ 2267 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2268 leave_non_blocking(); 2269 if (options.control_path != NULL && muxserver_sock != -1) 2270 unlink(options.control_path); 2271 ssh_kill_proxy_command(); 2272 _exit(i); 2273} 2274