1 /* $OpenBSD: clientloop.c,v 1.261 2014/07/15 15:54:14 millert 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 63 #include <sys/types.h> 64 #include <sys/ioctl.h> 65 #include <sys/stat.h> 66 #include <sys/socket.h> 67 #include <sys/time.h> 68 #include <sys/param.h> 69 #include <sys/queue.h> 70 71 #include <ctype.h> 72 #include <errno.h> 73 #include <paths.h> 74 #include <signal.h> 75 #include <stdio.h> 76 #include <stdlib.h> 77 #include <string.h> 78 #include <termios.h> 79 #include <pwd.h> 80 #include <unistd.h> 81 82 #include "xmalloc.h" 83 #include "ssh.h" 84 #include "ssh1.h" 85 #include "ssh2.h" 86 #include "packet.h" 87 #include "buffer.h" 88 #include "compat.h" 89 #include "channels.h" 90 #include "dispatch.h" 91 #include "key.h" 92 #include "cipher.h" 93 #include "kex.h" 94 #include "log.h" 95 #include "misc.h" 96 #include "readconf.h" 97 #include "clientloop.h" 98 #include "sshconnect.h" 99 #include "authfd.h" 100 #include "atomicio.h" 101 #include "sshpty.h" 102 #include "match.h" 103 #include "msg.h" 104 #include "roaming.h" 105 106 /* import options */ 107 extern Options options; 108 109 /* Flag indicating that stdin should be redirected from /dev/null. */ 110 extern int stdin_null_flag; 111 112 /* Flag indicating that no shell has been requested */ 113 extern int no_shell_flag; 114 115 /* Control socket */ 116 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 117 118 /* 119 * Name of the host we are connecting to. This is the name given on the 120 * command line, or the HostName specified for the user-supplied name in a 121 * configuration file. 122 */ 123 extern char *host; 124 125 /* 126 * Flag to indicate that we have received a window change signal which has 127 * not yet been processed. This will cause a message indicating the new 128 * window size to be sent to the server a little later. This is volatile 129 * because this is updated in a signal handler. 130 */ 131 static volatile sig_atomic_t received_window_change_signal = 0; 132 static volatile sig_atomic_t received_signal = 0; 133 134 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 135 static int in_non_blocking_mode = 0; 136 137 /* Time when backgrounded control master using ControlPersist should exit */ 138 static time_t control_persist_exit_time = 0; 139 140 /* Common data for the client loop code. */ 141 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 142 static int escape_char1; /* Escape character. (proto1 only) */ 143 static int escape_pending1; /* Last character was an escape (proto1 only) */ 144 static int last_was_cr; /* Last character was a newline. */ 145 static int exit_status; /* Used to store the command exit status. */ 146 static int stdin_eof; /* EOF has been encountered on stderr. */ 147 static Buffer stdin_buffer; /* Buffer for stdin data. */ 148 static Buffer stdout_buffer; /* Buffer for stdout data. */ 149 static Buffer stderr_buffer; /* Buffer for stderr data. */ 150 static u_int buffer_high; /* Soft max buffer size. */ 151 static int connection_in; /* Connection to server (input). */ 152 static int connection_out; /* Connection to server (output). */ 153 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 154 static int session_closed; /* In SSH2: login session closed. */ 155 static int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 156 157 static void client_init_dispatch(void); 158 int session_ident = -1; 159 160 int session_resumed = 0; 161 162 /* Track escape per proto2 channel */ 163 struct escape_filter_ctx { 164 int escape_pending; 165 int escape_char; 166 }; 167 168 /* Context for channel confirmation replies */ 169 struct channel_reply_ctx { 170 const char *request_type; 171 int id; 172 enum confirm_action action; 173 }; 174 175 /* Global request success/failure callbacks */ 176 struct global_confirm { 177 TAILQ_ENTRY(global_confirm) entry; 178 global_confirm_cb *cb; 179 void *ctx; 180 int ref_count; 181 }; 182 TAILQ_HEAD(global_confirms, global_confirm); 183 static struct global_confirms global_confirms = 184 TAILQ_HEAD_INITIALIZER(global_confirms); 185 186 /*XXX*/ 187 extern Kex *xxx_kex; 188 189 void ssh_process_session2_setup(int, int, int, Buffer *); 190 191 /* Restores stdin to blocking mode. */ 192 193 static void 194 leave_non_blocking(void) 195 { 196 if (in_non_blocking_mode) { 197 unset_nonblock(fileno(stdin)); 198 in_non_blocking_mode = 0; 199 } 200 } 201 202 /* Puts stdin terminal in non-blocking mode. */ 203 204 static void 205 enter_non_blocking(void) 206 { 207 in_non_blocking_mode = 1; 208 set_nonblock(fileno(stdin)); 209 } 210 211 /* 212 * Signal handler for the window change signal (SIGWINCH). This just sets a 213 * flag indicating that the window has changed. 214 */ 215 /*ARGSUSED */ 216 static void 217 window_change_handler(int sig) 218 { 219 received_window_change_signal = 1; 220 signal(SIGWINCH, window_change_handler); 221 } 222 223 /* 224 * Signal handler for signals that cause the program to terminate. These 225 * signals must be trapped to restore terminal modes. 226 */ 227 /*ARGSUSED */ 228 static void 229 signal_handler(int sig) 230 { 231 received_signal = sig; 232 quit_pending = 1; 233 } 234 235 /* 236 * Returns current time in seconds from Jan 1, 1970 with the maximum 237 * available resolution. 238 */ 239 240 static double 241 get_current_time(void) 242 { 243 struct timeval tv; 244 gettimeofday(&tv, NULL); 245 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 246 } 247 248 /* 249 * Sets control_persist_exit_time to the absolute time when the 250 * backgrounded control master should exit due to expiry of the 251 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded 252 * control master process, or if there is no ControlPersist timeout. 253 */ 254 static void 255 set_control_persist_exit_time(void) 256 { 257 if (muxserver_sock == -1 || !options.control_persist 258 || options.control_persist_timeout == 0) { 259 /* not using a ControlPersist timeout */ 260 control_persist_exit_time = 0; 261 } else if (channel_still_open()) { 262 /* some client connections are still open */ 263 if (control_persist_exit_time > 0) 264 debug2("%s: cancel scheduled exit", __func__); 265 control_persist_exit_time = 0; 266 } else if (control_persist_exit_time <= 0) { 267 /* a client connection has recently closed */ 268 control_persist_exit_time = monotime() + 269 (time_t)options.control_persist_timeout; 270 debug2("%s: schedule exit in %d seconds", __func__, 271 options.control_persist_timeout); 272 } 273 /* else we are already counting down to the timeout */ 274 } 275 276 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" 277 static int 278 client_x11_display_valid(const char *display) 279 { 280 size_t i, dlen; 281 282 dlen = strlen(display); 283 for (i = 0; i < dlen; i++) { 284 if (!isalnum((u_char)display[i]) && 285 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 286 debug("Invalid character '%c' in DISPLAY", display[i]); 287 return 0; 288 } 289 } 290 return 1; 291 } 292 293 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 294 void 295 client_x11_get_proto(const char *display, const char *xauth_path, 296 u_int trusted, u_int timeout, char **_proto, char **_data) 297 { 298 char cmd[1024]; 299 char line[512]; 300 char xdisplay[512]; 301 static char proto[512], data[512]; 302 FILE *f; 303 int got_data = 0, generated = 0, do_unlink = 0, i; 304 char *xauthdir, *xauthfile; 305 struct stat st; 306 u_int now; 307 308 xauthdir = xauthfile = NULL; 309 *_proto = proto; 310 *_data = data; 311 proto[0] = data[0] = '\0'; 312 313 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 314 debug("No xauth program."); 315 } else if (!client_x11_display_valid(display)) { 316 logit("DISPLAY '%s' invalid, falling back to fake xauth data", 317 display); 318 } else { 319 if (display == NULL) { 320 debug("x11_get_proto: DISPLAY not set"); 321 return; 322 } 323 /* 324 * Handle FamilyLocal case where $DISPLAY does 325 * not match an authorization entry. For this we 326 * just try "xauth list unix:displaynum.screennum". 327 * XXX: "localhost" match to determine FamilyLocal 328 * is not perfect. 329 */ 330 if (strncmp(display, "localhost:", 10) == 0) { 331 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 332 display + 10); 333 display = xdisplay; 334 } 335 if (trusted == 0) { 336 xauthdir = xmalloc(MAXPATHLEN); 337 xauthfile = xmalloc(MAXPATHLEN); 338 mktemp_proto(xauthdir, MAXPATHLEN); 339 if (mkdtemp(xauthdir) != NULL) { 340 do_unlink = 1; 341 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", 342 xauthdir); 343 snprintf(cmd, sizeof(cmd), 344 "%s -f %s generate %s " SSH_X11_PROTO 345 " untrusted timeout %u 2>" _PATH_DEVNULL, 346 xauth_path, xauthfile, display, timeout); 347 debug2("x11_get_proto: %s", cmd); 348 if (system(cmd) == 0) 349 generated = 1; 350 if (x11_refuse_time == 0) { 351 now = monotime() + 1; 352 if (UINT_MAX - timeout < now) 353 x11_refuse_time = UINT_MAX; 354 else 355 x11_refuse_time = now + timeout; 356 } 357 } 358 } 359 360 /* 361 * When in untrusted mode, we read the cookie only if it was 362 * successfully generated as an untrusted one in the step 363 * above. 364 */ 365 if (trusted || generated) { 366 snprintf(cmd, sizeof(cmd), 367 "%s %s%s list %s 2>" _PATH_DEVNULL, 368 xauth_path, 369 generated ? "-f " : "" , 370 generated ? xauthfile : "", 371 display); 372 debug2("x11_get_proto: %s", cmd); 373 f = popen(cmd, "r"); 374 if (f && fgets(line, sizeof(line), f) && 375 sscanf(line, "%*s %511s %511s", proto, data) == 2) 376 got_data = 1; 377 if (f) 378 pclose(f); 379 } else 380 error("Warning: untrusted X11 forwarding setup failed: " 381 "xauth key data not generated"); 382 } 383 384 if (do_unlink) { 385 unlink(xauthfile); 386 rmdir(xauthdir); 387 } 388 free(xauthdir); 389 free(xauthfile); 390 391 /* 392 * If we didn't get authentication data, just make up some 393 * data. The forwarding code will check the validity of the 394 * response anyway, and substitute this data. The X11 395 * server, however, will ignore this fake data and use 396 * whatever authentication mechanisms it was using otherwise 397 * for the local connection. 398 */ 399 if (!got_data) { 400 u_int32_t rnd = 0; 401 402 logit("Warning: No xauth data; " 403 "using fake authentication data for X11 forwarding."); 404 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 405 for (i = 0; i < 16; i++) { 406 if (i % 4 == 0) 407 rnd = arc4random(); 408 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 409 rnd & 0xff); 410 rnd >>= 8; 411 } 412 } 413 } 414 415 /* 416 * This is called when the interactive is entered. This checks if there is 417 * an EOF coming on stdin. We must check this explicitly, as select() does 418 * not appear to wake up when redirecting from /dev/null. 419 */ 420 421 static void 422 client_check_initial_eof_on_stdin(void) 423 { 424 int len; 425 char buf[1]; 426 427 /* 428 * If standard input is to be "redirected from /dev/null", we simply 429 * mark that we have seen an EOF and send an EOF message to the 430 * server. Otherwise, we try to read a single character; it appears 431 * that for some files, such /dev/null, select() never wakes up for 432 * read for this descriptor, which means that we never get EOF. This 433 * way we will get the EOF if stdin comes from /dev/null or similar. 434 */ 435 if (stdin_null_flag) { 436 /* Fake EOF on stdin. */ 437 debug("Sending eof."); 438 stdin_eof = 1; 439 packet_start(SSH_CMSG_EOF); 440 packet_send(); 441 } else { 442 enter_non_blocking(); 443 444 /* Check for immediate EOF on stdin. */ 445 len = read(fileno(stdin), buf, 1); 446 if (len == 0) { 447 /* 448 * EOF. Record that we have seen it and send 449 * EOF to server. 450 */ 451 debug("Sending eof."); 452 stdin_eof = 1; 453 packet_start(SSH_CMSG_EOF); 454 packet_send(); 455 } else if (len > 0) { 456 /* 457 * Got data. We must store the data in the buffer, 458 * and also process it as an escape character if 459 * appropriate. 460 */ 461 if ((u_char) buf[0] == escape_char1) 462 escape_pending1 = 1; 463 else 464 buffer_append(&stdin_buffer, buf, 1); 465 } 466 leave_non_blocking(); 467 } 468 } 469 470 471 /* 472 * Make packets from buffered stdin data, and buffer them for sending to the 473 * connection. 474 */ 475 476 static void 477 client_make_packets_from_stdin_data(void) 478 { 479 u_int len; 480 481 /* Send buffered stdin data to the server. */ 482 while (buffer_len(&stdin_buffer) > 0 && 483 packet_not_very_much_data_to_write()) { 484 len = buffer_len(&stdin_buffer); 485 /* Keep the packets at reasonable size. */ 486 if (len > packet_get_maxsize()) 487 len = packet_get_maxsize(); 488 packet_start(SSH_CMSG_STDIN_DATA); 489 packet_put_string(buffer_ptr(&stdin_buffer), len); 490 packet_send(); 491 buffer_consume(&stdin_buffer, len); 492 /* If we have a pending EOF, send it now. */ 493 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 494 packet_start(SSH_CMSG_EOF); 495 packet_send(); 496 } 497 } 498 } 499 500 /* 501 * Checks if the client window has changed, and sends a packet about it to 502 * the server if so. The actual change is detected elsewhere (by a software 503 * interrupt on Unix); this just checks the flag and sends a message if 504 * appropriate. 505 */ 506 507 static void 508 client_check_window_change(void) 509 { 510 struct winsize ws; 511 512 if (! received_window_change_signal) 513 return; 514 /** XXX race */ 515 received_window_change_signal = 0; 516 517 debug2("client_check_window_change: changed"); 518 519 if (compat20) { 520 channel_send_window_changes(); 521 } else { 522 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 523 return; 524 packet_start(SSH_CMSG_WINDOW_SIZE); 525 packet_put_int((u_int)ws.ws_row); 526 packet_put_int((u_int)ws.ws_col); 527 packet_put_int((u_int)ws.ws_xpixel); 528 packet_put_int((u_int)ws.ws_ypixel); 529 packet_send(); 530 } 531 } 532 533 static void 534 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 535 { 536 struct global_confirm *gc; 537 538 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 539 return; 540 if (gc->cb != NULL) 541 gc->cb(type, seq, gc->ctx); 542 if (--gc->ref_count <= 0) { 543 TAILQ_REMOVE(&global_confirms, gc, entry); 544 explicit_bzero(gc, sizeof(*gc)); 545 free(gc); 546 } 547 548 packet_set_alive_timeouts(0); 549 } 550 551 static void 552 server_alive_check(void) 553 { 554 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 555 logit("Timeout, server %s not responding.", host); 556 cleanup_exit(255); 557 } 558 packet_start(SSH2_MSG_GLOBAL_REQUEST); 559 packet_put_cstring("keepalive@openssh.com"); 560 packet_put_char(1); /* boolean: want reply */ 561 packet_send(); 562 /* Insert an empty placeholder to maintain ordering */ 563 client_register_global_confirm(NULL, NULL); 564 } 565 566 /* 567 * Waits until the client can do something (some data becomes available on 568 * one of the file descriptors). 569 */ 570 static void 571 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 572 int *maxfdp, u_int *nallocp, int rekeying) 573 { 574 struct timeval tv, *tvp; 575 int timeout_secs; 576 time_t minwait_secs = 0, server_alive_time = 0, now = monotime(); 577 int ret; 578 579 /* Add any selections by the channel mechanism. */ 580 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 581 &minwait_secs, rekeying); 582 583 if (!compat20) { 584 /* Read from the connection, unless our buffers are full. */ 585 if (buffer_len(&stdout_buffer) < buffer_high && 586 buffer_len(&stderr_buffer) < buffer_high && 587 channel_not_very_much_buffered_data()) 588 FD_SET(connection_in, *readsetp); 589 /* 590 * Read from stdin, unless we have seen EOF or have very much 591 * buffered data to send to the server. 592 */ 593 if (!stdin_eof && packet_not_very_much_data_to_write()) 594 FD_SET(fileno(stdin), *readsetp); 595 596 /* Select stdout/stderr if have data in buffer. */ 597 if (buffer_len(&stdout_buffer) > 0) 598 FD_SET(fileno(stdout), *writesetp); 599 if (buffer_len(&stderr_buffer) > 0) 600 FD_SET(fileno(stderr), *writesetp); 601 } else { 602 /* channel_prepare_select could have closed the last channel */ 603 if (session_closed && !channel_still_open() && 604 !packet_have_data_to_write()) { 605 /* clear mask since we did not call select() */ 606 memset(*readsetp, 0, *nallocp); 607 memset(*writesetp, 0, *nallocp); 608 return; 609 } else { 610 FD_SET(connection_in, *readsetp); 611 } 612 } 613 614 /* Select server connection if have data to write to the server. */ 615 if (packet_have_data_to_write()) 616 FD_SET(connection_out, *writesetp); 617 618 /* 619 * Wait for something to happen. This will suspend the process until 620 * some selected descriptor can be read, written, or has some other 621 * event pending, or a timeout expires. 622 */ 623 624 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 625 if (options.server_alive_interval > 0 && compat20) { 626 timeout_secs = options.server_alive_interval; 627 server_alive_time = now + options.server_alive_interval; 628 } 629 if (options.rekey_interval > 0 && compat20 && !rekeying) 630 timeout_secs = MIN(timeout_secs, packet_get_rekey_timeout()); 631 set_control_persist_exit_time(); 632 if (control_persist_exit_time > 0) { 633 timeout_secs = MIN(timeout_secs, 634 control_persist_exit_time - now); 635 if (timeout_secs < 0) 636 timeout_secs = 0; 637 } 638 if (minwait_secs != 0) 639 timeout_secs = MIN(timeout_secs, (int)minwait_secs); 640 if (timeout_secs == INT_MAX) 641 tvp = NULL; 642 else { 643 tv.tv_sec = timeout_secs; 644 tv.tv_usec = 0; 645 tvp = &tv; 646 } 647 648 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 649 if (ret < 0) { 650 char buf[100]; 651 652 /* 653 * We have to clear the select masks, because we return. 654 * We have to return, because the mainloop checks for the flags 655 * set by the signal handlers. 656 */ 657 memset(*readsetp, 0, *nallocp); 658 memset(*writesetp, 0, *nallocp); 659 660 if (errno == EINTR) 661 return; 662 /* Note: we might still have data in the buffers. */ 663 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 664 buffer_append(&stderr_buffer, buf, strlen(buf)); 665 quit_pending = 1; 666 } else if (ret == 0) { 667 /* 668 * Timeout. Could have been either keepalive or rekeying. 669 * Keepalive we check here, rekeying is checked in clientloop. 670 */ 671 if (server_alive_time != 0 && server_alive_time <= monotime()) 672 server_alive_check(); 673 } 674 675 } 676 677 static void 678 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 679 { 680 /* Flush stdout and stderr buffers. */ 681 if (buffer_len(bout) > 0) 682 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 683 buffer_len(bout)); 684 if (buffer_len(berr) > 0) 685 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 686 buffer_len(berr)); 687 688 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 689 690 /* 691 * Free (and clear) the buffer to reduce the amount of data that gets 692 * written to swap. 693 */ 694 buffer_free(bin); 695 buffer_free(bout); 696 buffer_free(berr); 697 698 /* Send the suspend signal to the program itself. */ 699 kill(getpid(), SIGTSTP); 700 701 /* Reset window sizes in case they have changed */ 702 received_window_change_signal = 1; 703 704 /* OK, we have been continued by the user. Reinitialize buffers. */ 705 buffer_init(bin); 706 buffer_init(bout); 707 buffer_init(berr); 708 709 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 710 } 711 712 static void 713 client_process_net_input(fd_set *readset) 714 { 715 int len, cont = 0; 716 char buf[8192]; 717 718 /* 719 * Read input from the server, and add any such data to the buffer of 720 * the packet subsystem. 721 */ 722 if (FD_ISSET(connection_in, readset)) { 723 /* Read as much as possible. */ 724 len = roaming_read(connection_in, buf, sizeof(buf), &cont); 725 if (len == 0 && cont == 0) { 726 /* 727 * Received EOF. The remote host has closed the 728 * connection. 729 */ 730 snprintf(buf, sizeof buf, 731 "Connection to %.300s closed by remote host.\r\n", 732 host); 733 buffer_append(&stderr_buffer, buf, strlen(buf)); 734 quit_pending = 1; 735 return; 736 } 737 /* 738 * There is a kernel bug on Solaris that causes select to 739 * sometimes wake up even though there is no data available. 740 */ 741 if (len < 0 && (errno == EAGAIN || errno == EINTR)) 742 len = 0; 743 744 if (len < 0) { 745 /* 746 * An error has encountered. Perhaps there is a 747 * network problem. 748 */ 749 snprintf(buf, sizeof buf, 750 "Read from remote host %.300s: %.100s\r\n", 751 host, strerror(errno)); 752 buffer_append(&stderr_buffer, buf, strlen(buf)); 753 quit_pending = 1; 754 return; 755 } 756 packet_process_incoming(buf, len); 757 } 758 } 759 760 static void 761 client_status_confirm(int type, Channel *c, void *ctx) 762 { 763 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 764 char errmsg[256]; 765 int tochan; 766 767 /* 768 * If a TTY was explicitly requested, then a failure to allocate 769 * one is fatal. 770 */ 771 if (cr->action == CONFIRM_TTY && 772 (options.request_tty == REQUEST_TTY_FORCE || 773 options.request_tty == REQUEST_TTY_YES)) 774 cr->action = CONFIRM_CLOSE; 775 776 /* XXX supress on mux _client_ quietmode */ 777 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 778 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 779 780 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 781 debug2("%s request accepted on channel %d", 782 cr->request_type, c->self); 783 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 784 if (tochan) { 785 snprintf(errmsg, sizeof(errmsg), 786 "%s request failed\r\n", cr->request_type); 787 } else { 788 snprintf(errmsg, sizeof(errmsg), 789 "%s request failed on channel %d", 790 cr->request_type, c->self); 791 } 792 /* If error occurred on primary session channel, then exit */ 793 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 794 fatal("%s", errmsg); 795 /* 796 * If error occurred on mux client, append to 797 * their stderr. 798 */ 799 if (tochan) { 800 buffer_append(&c->extended, errmsg, 801 strlen(errmsg)); 802 } else 803 error("%s", errmsg); 804 if (cr->action == CONFIRM_TTY) { 805 /* 806 * If a TTY allocation error occurred, then arrange 807 * for the correct TTY to leave raw mode. 808 */ 809 if (c->self == session_ident) 810 leave_raw_mode(0); 811 else 812 mux_tty_alloc_failed(c); 813 } else if (cr->action == CONFIRM_CLOSE) { 814 chan_read_failed(c); 815 chan_write_failed(c); 816 } 817 } 818 free(cr); 819 } 820 821 static void 822 client_abandon_status_confirm(Channel *c, void *ctx) 823 { 824 free(ctx); 825 } 826 827 void 828 client_expect_confirm(int id, const char *request, 829 enum confirm_action action) 830 { 831 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 832 833 cr->request_type = request; 834 cr->action = action; 835 836 channel_register_status_confirm(id, client_status_confirm, 837 client_abandon_status_confirm, cr); 838 } 839 840 void 841 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 842 { 843 struct global_confirm *gc, *last_gc; 844 845 /* Coalesce identical callbacks */ 846 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 847 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 848 if (++last_gc->ref_count >= INT_MAX) 849 fatal("%s: last_gc->ref_count = %d", 850 __func__, last_gc->ref_count); 851 return; 852 } 853 854 gc = xcalloc(1, sizeof(*gc)); 855 gc->cb = cb; 856 gc->ctx = ctx; 857 gc->ref_count = 1; 858 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 859 } 860 861 static void 862 process_cmdline(void) 863 { 864 void (*handler)(int); 865 char *s, *cmd; 866 int ok, delete = 0, local = 0, remote = 0, dynamic = 0; 867 struct Forward fwd; 868 869 memset(&fwd, 0, sizeof(fwd)); 870 871 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 872 handler = signal(SIGINT, SIG_IGN); 873 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 874 if (s == NULL) 875 goto out; 876 while (isspace((u_char)*s)) 877 s++; 878 if (*s == '-') 879 s++; /* Skip cmdline '-', if any */ 880 if (*s == '\0') 881 goto out; 882 883 if (*s == 'h' || *s == 'H' || *s == '?') { 884 logit("Commands:"); 885 logit(" -L[bind_address:]port:host:hostport " 886 "Request local forward"); 887 logit(" -R[bind_address:]port:host:hostport " 888 "Request remote forward"); 889 logit(" -D[bind_address:]port " 890 "Request dynamic forward"); 891 logit(" -KL[bind_address:]port " 892 "Cancel local forward"); 893 logit(" -KR[bind_address:]port " 894 "Cancel remote forward"); 895 logit(" -KD[bind_address:]port " 896 "Cancel dynamic forward"); 897 if (!options.permit_local_command) 898 goto out; 899 logit(" !args " 900 "Execute local command"); 901 goto out; 902 } 903 904 if (*s == '!' && options.permit_local_command) { 905 s++; 906 ssh_local_cmd(s); 907 goto out; 908 } 909 910 if (*s == 'K') { 911 delete = 1; 912 s++; 913 } 914 if (*s == 'L') 915 local = 1; 916 else if (*s == 'R') 917 remote = 1; 918 else if (*s == 'D') 919 dynamic = 1; 920 else { 921 logit("Invalid command."); 922 goto out; 923 } 924 925 if (delete && !compat20) { 926 logit("Not supported for SSH protocol version 1."); 927 goto out; 928 } 929 930 while (isspace((u_char)*++s)) 931 ; 932 933 /* XXX update list of forwards in options */ 934 if (delete) { 935 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ 936 if (!parse_forward(&fwd, s, 1, 0)) { 937 logit("Bad forwarding close specification."); 938 goto out; 939 } 940 if (remote) 941 ok = channel_request_rforward_cancel(&fwd) == 0; 942 else if (dynamic) 943 ok = channel_cancel_lport_listener(&fwd, 944 0, &options.fwd_opts) > 0; 945 else 946 ok = channel_cancel_lport_listener(&fwd, 947 CHANNEL_CANCEL_PORT_STATIC, 948 &options.fwd_opts) > 0; 949 if (!ok) { 950 logit("Unkown port forwarding."); 951 goto out; 952 } 953 logit("Canceled forwarding."); 954 } else { 955 if (!parse_forward(&fwd, s, dynamic, remote)) { 956 logit("Bad forwarding specification."); 957 goto out; 958 } 959 if (local || dynamic) { 960 if (!channel_setup_local_fwd_listener(&fwd, 961 &options.fwd_opts)) { 962 logit("Port forwarding failed."); 963 goto out; 964 } 965 } else { 966 if (channel_request_remote_forwarding(&fwd) < 0) { 967 logit("Port forwarding failed."); 968 goto out; 969 } 970 } 971 logit("Forwarding port."); 972 } 973 974 out: 975 signal(SIGINT, handler); 976 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 977 free(cmd); 978 free(fwd.listen_host); 979 free(fwd.listen_path); 980 free(fwd.connect_host); 981 free(fwd.connect_path); 982 } 983 984 /* reasons to suppress output of an escape command in help output */ 985 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 986 #define SUPPRESS_PROTO1 1 /* don't show in protocol 1 sessions */ 987 #define SUPPRESS_MUXCLIENT 2 /* don't show in mux client sessions */ 988 #define SUPPRESS_MUXMASTER 4 /* don't show in mux master sessions */ 989 #define SUPPRESS_SYSLOG 8 /* don't show when logging to syslog */ 990 struct escape_help_text { 991 const char *cmd; 992 const char *text; 993 unsigned int flags; 994 }; 995 static struct escape_help_text esc_txt[] = { 996 {".", "terminate session", SUPPRESS_MUXMASTER}, 997 {".", "terminate connection (and any multiplexed sessions)", 998 SUPPRESS_MUXCLIENT}, 999 {"B", "send a BREAK to the remote system", SUPPRESS_PROTO1}, 1000 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 1001 {"R", "request rekey", SUPPRESS_PROTO1}, 1002 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 1003 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 1004 {"#", "list forwarded connections", SUPPRESS_NEVER}, 1005 {"&", "background ssh (when waiting for connections to terminate)", 1006 SUPPRESS_MUXCLIENT}, 1007 {"?", "this message", SUPPRESS_NEVER}, 1008 }; 1009 1010 static void 1011 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client, 1012 int using_stderr) 1013 { 1014 unsigned int i, suppress_flags; 1015 char string[1024]; 1016 1017 snprintf(string, sizeof string, "%c?\r\n" 1018 "Supported escape sequences:\r\n", escape_char); 1019 buffer_append(b, string, strlen(string)); 1020 1021 suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) | 1022 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 1023 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 1024 (using_stderr ? 0 : SUPPRESS_SYSLOG); 1025 1026 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 1027 if (esc_txt[i].flags & suppress_flags) 1028 continue; 1029 snprintf(string, sizeof string, " %c%-3s - %s\r\n", 1030 escape_char, esc_txt[i].cmd, esc_txt[i].text); 1031 buffer_append(b, string, strlen(string)); 1032 } 1033 1034 snprintf(string, sizeof string, 1035 " %c%c - send the escape character by typing it twice\r\n" 1036 "(Note that escapes are only recognized immediately after " 1037 "newline.)\r\n", escape_char, escape_char); 1038 buffer_append(b, string, strlen(string)); 1039 } 1040 1041 /* 1042 * Process the characters one by one, call with c==NULL for proto1 case. 1043 */ 1044 static int 1045 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 1046 char *buf, int len) 1047 { 1048 char string[1024]; 1049 pid_t pid; 1050 int bytes = 0; 1051 u_int i; 1052 u_char ch; 1053 char *s; 1054 int *escape_pendingp, escape_char; 1055 struct escape_filter_ctx *efc; 1056 1057 if (c == NULL) { 1058 escape_pendingp = &escape_pending1; 1059 escape_char = escape_char1; 1060 } else { 1061 if (c->filter_ctx == NULL) 1062 return 0; 1063 efc = (struct escape_filter_ctx *)c->filter_ctx; 1064 escape_pendingp = &efc->escape_pending; 1065 escape_char = efc->escape_char; 1066 } 1067 1068 if (len <= 0) 1069 return (0); 1070 1071 for (i = 0; i < (u_int)len; i++) { 1072 /* Get one character at a time. */ 1073 ch = buf[i]; 1074 1075 if (*escape_pendingp) { 1076 /* We have previously seen an escape character. */ 1077 /* Clear the flag now. */ 1078 *escape_pendingp = 0; 1079 1080 /* Process the escaped character. */ 1081 switch (ch) { 1082 case '.': 1083 /* Terminate the connection. */ 1084 snprintf(string, sizeof string, "%c.\r\n", 1085 escape_char); 1086 buffer_append(berr, string, strlen(string)); 1087 1088 if (c && c->ctl_chan != -1) { 1089 chan_read_failed(c); 1090 chan_write_failed(c); 1091 if (c->detach_user) 1092 c->detach_user(c->self, NULL); 1093 c->type = SSH_CHANNEL_ABANDONED; 1094 buffer_clear(&c->input); 1095 chan_ibuf_empty(c); 1096 return 0; 1097 } else 1098 quit_pending = 1; 1099 return -1; 1100 1101 case 'Z' - 64: 1102 /* XXX support this for mux clients */ 1103 if (c && c->ctl_chan != -1) { 1104 char b[16]; 1105 noescape: 1106 if (ch == 'Z' - 64) 1107 snprintf(b, sizeof b, "^Z"); 1108 else 1109 snprintf(b, sizeof b, "%c", ch); 1110 snprintf(string, sizeof string, 1111 "%c%s escape not available to " 1112 "multiplexed sessions\r\n", 1113 escape_char, b); 1114 buffer_append(berr, string, 1115 strlen(string)); 1116 continue; 1117 } 1118 /* Suspend the program. Inform the user */ 1119 snprintf(string, sizeof string, 1120 "%c^Z [suspend ssh]\r\n", escape_char); 1121 buffer_append(berr, string, strlen(string)); 1122 1123 /* Restore terminal modes and suspend. */ 1124 client_suspend_self(bin, bout, berr); 1125 1126 /* We have been continued. */ 1127 continue; 1128 1129 case 'B': 1130 if (compat20) { 1131 snprintf(string, sizeof string, 1132 "%cB\r\n", escape_char); 1133 buffer_append(berr, string, 1134 strlen(string)); 1135 channel_request_start(c->self, 1136 "break", 0); 1137 packet_put_int(1000); 1138 packet_send(); 1139 } 1140 continue; 1141 1142 case 'R': 1143 if (compat20) { 1144 if (datafellows & SSH_BUG_NOREKEY) 1145 logit("Server does not " 1146 "support re-keying"); 1147 else 1148 need_rekeying = 1; 1149 } 1150 continue; 1151 1152 case 'V': 1153 /* FALLTHROUGH */ 1154 case 'v': 1155 if (c && c->ctl_chan != -1) 1156 goto noescape; 1157 if (!log_is_on_stderr()) { 1158 snprintf(string, sizeof string, 1159 "%c%c [Logging to syslog]\r\n", 1160 escape_char, ch); 1161 buffer_append(berr, string, 1162 strlen(string)); 1163 continue; 1164 } 1165 if (ch == 'V' && options.log_level > 1166 SYSLOG_LEVEL_QUIET) 1167 log_change_level(--options.log_level); 1168 if (ch == 'v' && options.log_level < 1169 SYSLOG_LEVEL_DEBUG3) 1170 log_change_level(++options.log_level); 1171 snprintf(string, sizeof string, 1172 "%c%c [LogLevel %s]\r\n", escape_char, ch, 1173 log_level_name(options.log_level)); 1174 buffer_append(berr, string, strlen(string)); 1175 continue; 1176 1177 case '&': 1178 if (c && c->ctl_chan != -1) 1179 goto noescape; 1180 /* 1181 * Detach the program (continue to serve 1182 * connections, but put in background and no 1183 * more new connections). 1184 */ 1185 /* Restore tty modes. */ 1186 leave_raw_mode( 1187 options.request_tty == REQUEST_TTY_FORCE); 1188 1189 /* Stop listening for new connections. */ 1190 channel_stop_listening(); 1191 1192 snprintf(string, sizeof string, 1193 "%c& [backgrounded]\n", escape_char); 1194 buffer_append(berr, string, strlen(string)); 1195 1196 /* Fork into background. */ 1197 pid = fork(); 1198 if (pid < 0) { 1199 error("fork: %.100s", strerror(errno)); 1200 continue; 1201 } 1202 if (pid != 0) { /* This is the parent. */ 1203 /* The parent just exits. */ 1204 exit(0); 1205 } 1206 /* The child continues serving connections. */ 1207 if (compat20) { 1208 buffer_append(bin, "\004", 1); 1209 /* fake EOF on stdin */ 1210 return -1; 1211 } else if (!stdin_eof) { 1212 /* 1213 * Sending SSH_CMSG_EOF alone does not 1214 * always appear to be enough. So we 1215 * try to send an EOF character first. 1216 */ 1217 packet_start(SSH_CMSG_STDIN_DATA); 1218 packet_put_string("\004", 1); 1219 packet_send(); 1220 /* Close stdin. */ 1221 stdin_eof = 1; 1222 if (buffer_len(bin) == 0) { 1223 packet_start(SSH_CMSG_EOF); 1224 packet_send(); 1225 } 1226 } 1227 continue; 1228 1229 case '?': 1230 print_escape_help(berr, escape_char, compat20, 1231 (c && c->ctl_chan != -1), 1232 log_is_on_stderr()); 1233 continue; 1234 1235 case '#': 1236 snprintf(string, sizeof string, "%c#\r\n", 1237 escape_char); 1238 buffer_append(berr, string, strlen(string)); 1239 s = channel_open_message(); 1240 buffer_append(berr, s, strlen(s)); 1241 free(s); 1242 continue; 1243 1244 case 'C': 1245 if (c && c->ctl_chan != -1) 1246 goto noescape; 1247 process_cmdline(); 1248 continue; 1249 1250 default: 1251 if (ch != escape_char) { 1252 buffer_put_char(bin, escape_char); 1253 bytes++; 1254 } 1255 /* Escaped characters fall through here */ 1256 break; 1257 } 1258 } else { 1259 /* 1260 * The previous character was not an escape char. 1261 * Check if this is an escape. 1262 */ 1263 if (last_was_cr && ch == escape_char) { 1264 /* 1265 * It is. Set the flag and continue to 1266 * next character. 1267 */ 1268 *escape_pendingp = 1; 1269 continue; 1270 } 1271 } 1272 1273 /* 1274 * Normal character. Record whether it was a newline, 1275 * and append it to the buffer. 1276 */ 1277 last_was_cr = (ch == '\r' || ch == '\n'); 1278 buffer_put_char(bin, ch); 1279 bytes++; 1280 } 1281 return bytes; 1282 } 1283 1284 static void 1285 client_process_input(fd_set *readset) 1286 { 1287 int len; 1288 char buf[8192]; 1289 1290 /* Read input from stdin. */ 1291 if (FD_ISSET(fileno(stdin), readset)) { 1292 /* Read as much as possible. */ 1293 len = read(fileno(stdin), buf, sizeof(buf)); 1294 if (len < 0 && (errno == EAGAIN || errno == EINTR)) 1295 return; /* we'll try again later */ 1296 if (len <= 0) { 1297 /* 1298 * Received EOF or error. They are treated 1299 * similarly, except that an error message is printed 1300 * if it was an error condition. 1301 */ 1302 if (len < 0) { 1303 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1304 strerror(errno)); 1305 buffer_append(&stderr_buffer, buf, strlen(buf)); 1306 } 1307 /* Mark that we have seen EOF. */ 1308 stdin_eof = 1; 1309 /* 1310 * Send an EOF message to the server unless there is 1311 * data in the buffer. If there is data in the 1312 * buffer, no message will be sent now. Code 1313 * elsewhere will send the EOF when the buffer 1314 * becomes empty if stdin_eof is set. 1315 */ 1316 if (buffer_len(&stdin_buffer) == 0) { 1317 packet_start(SSH_CMSG_EOF); 1318 packet_send(); 1319 } 1320 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1321 /* 1322 * Normal successful read, and no escape character. 1323 * Just append the data to buffer. 1324 */ 1325 buffer_append(&stdin_buffer, buf, len); 1326 } else { 1327 /* 1328 * Normal, successful read. But we have an escape 1329 * character and have to process the characters one 1330 * by one. 1331 */ 1332 if (process_escapes(NULL, &stdin_buffer, 1333 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1334 return; 1335 } 1336 } 1337 } 1338 1339 static void 1340 client_process_output(fd_set *writeset) 1341 { 1342 int len; 1343 char buf[100]; 1344 1345 /* Write buffered output to stdout. */ 1346 if (FD_ISSET(fileno(stdout), writeset)) { 1347 /* Write as much data as possible. */ 1348 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1349 buffer_len(&stdout_buffer)); 1350 if (len <= 0) { 1351 if (errno == EINTR || errno == EAGAIN) 1352 len = 0; 1353 else { 1354 /* 1355 * An error or EOF was encountered. Put an 1356 * error message to stderr buffer. 1357 */ 1358 snprintf(buf, sizeof buf, 1359 "write stdout: %.50s\r\n", strerror(errno)); 1360 buffer_append(&stderr_buffer, buf, strlen(buf)); 1361 quit_pending = 1; 1362 return; 1363 } 1364 } 1365 /* Consume printed data from the buffer. */ 1366 buffer_consume(&stdout_buffer, len); 1367 } 1368 /* Write buffered output to stderr. */ 1369 if (FD_ISSET(fileno(stderr), writeset)) { 1370 /* Write as much data as possible. */ 1371 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1372 buffer_len(&stderr_buffer)); 1373 if (len <= 0) { 1374 if (errno == EINTR || errno == EAGAIN) 1375 len = 0; 1376 else { 1377 /* 1378 * EOF or error, but can't even print 1379 * error message. 1380 */ 1381 quit_pending = 1; 1382 return; 1383 } 1384 } 1385 /* Consume printed characters from the buffer. */ 1386 buffer_consume(&stderr_buffer, len); 1387 } 1388 } 1389 1390 /* 1391 * Get packets from the connection input buffer, and process them as long as 1392 * there are packets available. 1393 * 1394 * Any unknown packets received during the actual 1395 * session cause the session to terminate. This is 1396 * intended to make debugging easier since no 1397 * confirmations are sent. Any compatible protocol 1398 * extensions must be negotiated during the 1399 * preparatory phase. 1400 */ 1401 1402 static void 1403 client_process_buffered_input_packets(void) 1404 { 1405 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1406 compat20 ? xxx_kex : NULL); 1407 } 1408 1409 /* scan buf[] for '~' before sending data to the peer */ 1410 1411 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1412 void * 1413 client_new_escape_filter_ctx(int escape_char) 1414 { 1415 struct escape_filter_ctx *ret; 1416 1417 ret = xcalloc(1, sizeof(*ret)); 1418 ret->escape_pending = 0; 1419 ret->escape_char = escape_char; 1420 return (void *)ret; 1421 } 1422 1423 /* Free the escape filter context on channel free */ 1424 void 1425 client_filter_cleanup(int cid, void *ctx) 1426 { 1427 free(ctx); 1428 } 1429 1430 int 1431 client_simple_escape_filter(Channel *c, char *buf, int len) 1432 { 1433 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1434 return 0; 1435 1436 return process_escapes(c, &c->input, &c->output, &c->extended, 1437 buf, len); 1438 } 1439 1440 static void 1441 client_channel_closed(int id, void *arg) 1442 { 1443 channel_cancel_cleanup(id); 1444 session_closed = 1; 1445 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1446 } 1447 1448 /* 1449 * Implements the interactive session with the server. This is called after 1450 * the user has been authenticated, and a command has been started on the 1451 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1452 * used as an escape character for terminating or suspending the session. 1453 */ 1454 1455 int 1456 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1457 { 1458 fd_set *readset = NULL, *writeset = NULL; 1459 double start_time, total_time; 1460 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1461 u_int64_t ibytes, obytes; 1462 u_int nalloc = 0; 1463 char buf[100]; 1464 1465 debug("Entering interactive session."); 1466 1467 start_time = get_current_time(); 1468 1469 /* Initialize variables. */ 1470 escape_pending1 = 0; 1471 last_was_cr = 1; 1472 exit_status = -1; 1473 stdin_eof = 0; 1474 buffer_high = 64 * 1024; 1475 connection_in = packet_get_connection_in(); 1476 connection_out = packet_get_connection_out(); 1477 max_fd = MAX(connection_in, connection_out); 1478 1479 if (!compat20) { 1480 /* enable nonblocking unless tty */ 1481 if (!isatty(fileno(stdin))) 1482 set_nonblock(fileno(stdin)); 1483 if (!isatty(fileno(stdout))) 1484 set_nonblock(fileno(stdout)); 1485 if (!isatty(fileno(stderr))) 1486 set_nonblock(fileno(stderr)); 1487 max_fd = MAX(max_fd, fileno(stdin)); 1488 max_fd = MAX(max_fd, fileno(stdout)); 1489 max_fd = MAX(max_fd, fileno(stderr)); 1490 } 1491 quit_pending = 0; 1492 escape_char1 = escape_char_arg; 1493 1494 /* Initialize buffers. */ 1495 buffer_init(&stdin_buffer); 1496 buffer_init(&stdout_buffer); 1497 buffer_init(&stderr_buffer); 1498 1499 client_init_dispatch(); 1500 1501 /* 1502 * Set signal handlers, (e.g. to restore non-blocking mode) 1503 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1504 */ 1505 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1506 signal(SIGHUP, signal_handler); 1507 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1508 signal(SIGINT, signal_handler); 1509 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1510 signal(SIGQUIT, signal_handler); 1511 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1512 signal(SIGTERM, signal_handler); 1513 signal(SIGWINCH, window_change_handler); 1514 1515 if (have_pty) 1516 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1517 1518 if (compat20) { 1519 session_ident = ssh2_chan_id; 1520 if (session_ident != -1) { 1521 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1522 channel_register_filter(session_ident, 1523 client_simple_escape_filter, NULL, 1524 client_filter_cleanup, 1525 client_new_escape_filter_ctx( 1526 escape_char_arg)); 1527 } 1528 channel_register_cleanup(session_ident, 1529 client_channel_closed, 0); 1530 } 1531 } else { 1532 /* Check if we should immediately send eof on stdin. */ 1533 client_check_initial_eof_on_stdin(); 1534 } 1535 1536 /* Main loop of the client for the interactive session mode. */ 1537 while (!quit_pending) { 1538 1539 /* Process buffered packets sent by the server. */ 1540 client_process_buffered_input_packets(); 1541 1542 if (compat20 && session_closed && !channel_still_open()) 1543 break; 1544 1545 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1546 1547 if (rekeying) { 1548 debug("rekeying in progress"); 1549 } else { 1550 /* 1551 * Make packets of buffered stdin data, and buffer 1552 * them for sending to the server. 1553 */ 1554 if (!compat20) 1555 client_make_packets_from_stdin_data(); 1556 1557 /* 1558 * Make packets from buffered channel data, and 1559 * enqueue them for sending to the server. 1560 */ 1561 if (packet_not_very_much_data_to_write()) 1562 channel_output_poll(); 1563 1564 /* 1565 * Check if the window size has changed, and buffer a 1566 * message about it to the server if so. 1567 */ 1568 client_check_window_change(); 1569 1570 if (quit_pending) 1571 break; 1572 } 1573 /* 1574 * Wait until we have something to do (something becomes 1575 * available on one of the descriptors). 1576 */ 1577 max_fd2 = max_fd; 1578 client_wait_until_can_do_something(&readset, &writeset, 1579 &max_fd2, &nalloc, rekeying); 1580 1581 if (quit_pending) 1582 break; 1583 1584 /* Do channel operations unless rekeying in progress. */ 1585 if (!rekeying) { 1586 channel_after_select(readset, writeset); 1587 if (need_rekeying || packet_need_rekeying()) { 1588 debug("need rekeying"); 1589 xxx_kex->done = 0; 1590 kex_send_kexinit(xxx_kex); 1591 need_rekeying = 0; 1592 } 1593 } 1594 1595 /* Buffer input from the connection. */ 1596 client_process_net_input(readset); 1597 1598 if (quit_pending) 1599 break; 1600 1601 if (!compat20) { 1602 /* Buffer data from stdin */ 1603 client_process_input(readset); 1604 /* 1605 * Process output to stdout and stderr. Output to 1606 * the connection is processed elsewhere (above). 1607 */ 1608 client_process_output(writeset); 1609 } 1610 1611 if (session_resumed) { 1612 connection_in = packet_get_connection_in(); 1613 connection_out = packet_get_connection_out(); 1614 max_fd = MAX(max_fd, connection_out); 1615 max_fd = MAX(max_fd, connection_in); 1616 session_resumed = 0; 1617 } 1618 1619 /* 1620 * Send as much buffered packet data as possible to the 1621 * sender. 1622 */ 1623 if (FD_ISSET(connection_out, writeset)) 1624 packet_write_poll(); 1625 1626 /* 1627 * If we are a backgrounded control master, and the 1628 * timeout has expired without any active client 1629 * connections, then quit. 1630 */ 1631 if (control_persist_exit_time > 0) { 1632 if (monotime() >= control_persist_exit_time) { 1633 debug("ControlPersist timeout expired"); 1634 break; 1635 } 1636 } 1637 } 1638 free(readset); 1639 free(writeset); 1640 1641 /* Terminate the session. */ 1642 1643 /* Stop watching for window change. */ 1644 signal(SIGWINCH, SIG_DFL); 1645 1646 if (compat20) { 1647 packet_start(SSH2_MSG_DISCONNECT); 1648 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1649 packet_put_cstring("disconnected by user"); 1650 packet_put_cstring(""); /* language tag */ 1651 packet_send(); 1652 packet_write_wait(); 1653 } 1654 1655 channel_free_all(); 1656 1657 if (have_pty) 1658 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1659 1660 /* restore blocking io */ 1661 if (!isatty(fileno(stdin))) 1662 unset_nonblock(fileno(stdin)); 1663 if (!isatty(fileno(stdout))) 1664 unset_nonblock(fileno(stdout)); 1665 if (!isatty(fileno(stderr))) 1666 unset_nonblock(fileno(stderr)); 1667 1668 /* 1669 * If there was no shell or command requested, there will be no remote 1670 * exit status to be returned. In that case, clear error code if the 1671 * connection was deliberately terminated at this end. 1672 */ 1673 if (no_shell_flag && received_signal == SIGTERM) { 1674 received_signal = 0; 1675 exit_status = 0; 1676 } 1677 1678 if (received_signal) 1679 fatal("Killed by signal %d.", (int) received_signal); 1680 1681 /* 1682 * In interactive mode (with pseudo tty) display a message indicating 1683 * that the connection has been closed. 1684 */ 1685 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1686 snprintf(buf, sizeof buf, 1687 "Connection to %.64s closed.\r\n", host); 1688 buffer_append(&stderr_buffer, buf, strlen(buf)); 1689 } 1690 1691 /* Output any buffered data for stdout. */ 1692 if (buffer_len(&stdout_buffer) > 0) { 1693 len = atomicio(vwrite, fileno(stdout), 1694 buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer)); 1695 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer)) 1696 error("Write failed flushing stdout buffer."); 1697 else 1698 buffer_consume(&stdout_buffer, len); 1699 } 1700 1701 /* Output any buffered data for stderr. */ 1702 if (buffer_len(&stderr_buffer) > 0) { 1703 len = atomicio(vwrite, fileno(stderr), 1704 buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer)); 1705 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer)) 1706 error("Write failed flushing stderr buffer."); 1707 else 1708 buffer_consume(&stderr_buffer, len); 1709 } 1710 1711 /* Clear and free any buffers. */ 1712 memset(buf, 0, sizeof(buf)); 1713 buffer_free(&stdin_buffer); 1714 buffer_free(&stdout_buffer); 1715 buffer_free(&stderr_buffer); 1716 1717 /* Report bytes transferred, and transfer rates. */ 1718 total_time = get_current_time() - start_time; 1719 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1720 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1721 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1722 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1723 if (total_time > 0) 1724 verbose("Bytes per second: sent %.1f, received %.1f", 1725 obytes / total_time, ibytes / total_time); 1726 /* Return the exit status of the program. */ 1727 debug("Exit status %d", exit_status); 1728 return exit_status; 1729 } 1730 1731 /*********/ 1732 1733 static void 1734 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1735 { 1736 u_int data_len; 1737 char *data = packet_get_string(&data_len); 1738 packet_check_eom(); 1739 buffer_append(&stdout_buffer, data, data_len); 1740 explicit_bzero(data, data_len); 1741 free(data); 1742 } 1743 static void 1744 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1745 { 1746 u_int data_len; 1747 char *data = packet_get_string(&data_len); 1748 packet_check_eom(); 1749 buffer_append(&stderr_buffer, data, data_len); 1750 explicit_bzero(data, data_len); 1751 free(data); 1752 } 1753 static void 1754 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1755 { 1756 exit_status = packet_get_int(); 1757 packet_check_eom(); 1758 /* Acknowledge the exit. */ 1759 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1760 packet_send(); 1761 /* 1762 * Must wait for packet to be sent since we are 1763 * exiting the loop. 1764 */ 1765 packet_write_wait(); 1766 /* Flag that we want to exit. */ 1767 quit_pending = 1; 1768 } 1769 static void 1770 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1771 { 1772 Channel *c = NULL; 1773 int remote_id, sock; 1774 1775 /* Read the remote channel number from the message. */ 1776 remote_id = packet_get_int(); 1777 packet_check_eom(); 1778 1779 /* 1780 * Get a connection to the local authentication agent (this may again 1781 * get forwarded). 1782 */ 1783 sock = ssh_get_authentication_socket(); 1784 1785 /* 1786 * If we could not connect the agent, send an error message back to 1787 * the server. This should never happen unless the agent dies, 1788 * because authentication forwarding is only enabled if we have an 1789 * agent. 1790 */ 1791 if (sock >= 0) { 1792 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1793 -1, 0, 0, 0, "authentication agent connection", 1); 1794 c->remote_id = remote_id; 1795 c->force_drain = 1; 1796 } 1797 if (c == NULL) { 1798 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1799 packet_put_int(remote_id); 1800 } else { 1801 /* Send a confirmation to the remote host. */ 1802 debug("Forwarding authentication connection."); 1803 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1804 packet_put_int(remote_id); 1805 packet_put_int(c->self); 1806 } 1807 packet_send(); 1808 } 1809 1810 static Channel * 1811 client_request_forwarded_tcpip(const char *request_type, int rchan) 1812 { 1813 Channel *c = NULL; 1814 char *listen_address, *originator_address; 1815 u_short listen_port, originator_port; 1816 1817 /* Get rest of the packet */ 1818 listen_address = packet_get_string(NULL); 1819 listen_port = packet_get_int(); 1820 originator_address = packet_get_string(NULL); 1821 originator_port = packet_get_int(); 1822 packet_check_eom(); 1823 1824 debug("%s: listen %s port %d, originator %s port %d", __func__, 1825 listen_address, listen_port, originator_address, originator_port); 1826 1827 c = channel_connect_by_listen_address(listen_address, listen_port, 1828 "forwarded-tcpip", originator_address); 1829 1830 free(originator_address); 1831 free(listen_address); 1832 return c; 1833 } 1834 1835 static Channel * 1836 client_request_forwarded_streamlocal(const char *request_type, int rchan) 1837 { 1838 Channel *c = NULL; 1839 char *listen_path; 1840 1841 /* Get the remote path. */ 1842 listen_path = packet_get_string(NULL); 1843 /* XXX: Skip reserved field for now. */ 1844 if (packet_get_string_ptr(NULL) == NULL) 1845 fatal("%s: packet_get_string_ptr failed", __func__); 1846 packet_check_eom(); 1847 1848 debug("%s: %s", __func__, listen_path); 1849 1850 c = channel_connect_by_listen_path(listen_path, 1851 "forwarded-streamlocal@openssh.com", "forwarded-streamlocal"); 1852 free(listen_path); 1853 return c; 1854 } 1855 1856 static Channel * 1857 client_request_x11(const char *request_type, int rchan) 1858 { 1859 Channel *c = NULL; 1860 char *originator; 1861 u_short originator_port; 1862 int sock; 1863 1864 if (!options.forward_x11) { 1865 error("Warning: ssh server tried X11 forwarding."); 1866 error("Warning: this is probably a break-in attempt by a " 1867 "malicious server."); 1868 return NULL; 1869 } 1870 if (x11_refuse_time != 0 && monotime() >= x11_refuse_time) { 1871 verbose("Rejected X11 connection after ForwardX11Timeout " 1872 "expired"); 1873 return NULL; 1874 } 1875 originator = packet_get_string(NULL); 1876 if (datafellows & SSH_BUG_X11FWD) { 1877 debug2("buggy server: x11 request w/o originator_port"); 1878 originator_port = 0; 1879 } else { 1880 originator_port = packet_get_int(); 1881 } 1882 packet_check_eom(); 1883 /* XXX check permission */ 1884 debug("client_request_x11: request from %s %d", originator, 1885 originator_port); 1886 free(originator); 1887 sock = x11_connect_display(); 1888 if (sock < 0) 1889 return NULL; 1890 c = channel_new("x11", 1891 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1892 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1893 c->force_drain = 1; 1894 return c; 1895 } 1896 1897 static Channel * 1898 client_request_agent(const char *request_type, int rchan) 1899 { 1900 Channel *c = NULL; 1901 int sock; 1902 1903 if (!options.forward_agent) { 1904 error("Warning: ssh server tried agent forwarding."); 1905 error("Warning: this is probably a break-in attempt by a " 1906 "malicious server."); 1907 return NULL; 1908 } 1909 sock = ssh_get_authentication_socket(); 1910 if (sock < 0) 1911 return NULL; 1912 c = channel_new("authentication agent connection", 1913 SSH_CHANNEL_OPEN, sock, sock, -1, 1914 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1915 "authentication agent connection", 1); 1916 c->force_drain = 1; 1917 return c; 1918 } 1919 1920 int 1921 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1922 { 1923 Channel *c; 1924 int fd; 1925 1926 if (tun_mode == SSH_TUNMODE_NO) 1927 return 0; 1928 1929 if (!compat20) { 1930 error("Tunnel forwarding is not supported for protocol 1"); 1931 return -1; 1932 } 1933 1934 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1935 1936 /* Open local tunnel device */ 1937 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1938 error("Tunnel device open failed."); 1939 return -1; 1940 } 1941 1942 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1943 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1944 c->datagram = 1; 1945 1946 packet_start(SSH2_MSG_CHANNEL_OPEN); 1947 packet_put_cstring("tun@openssh.com"); 1948 packet_put_int(c->self); 1949 packet_put_int(c->local_window_max); 1950 packet_put_int(c->local_maxpacket); 1951 packet_put_int(tun_mode); 1952 packet_put_int(remote_tun); 1953 packet_send(); 1954 1955 return 0; 1956 } 1957 1958 /* XXXX move to generic input handler */ 1959 static void 1960 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1961 { 1962 Channel *c = NULL; 1963 char *ctype; 1964 int rchan; 1965 u_int rmaxpack, rwindow, len; 1966 1967 ctype = packet_get_string(&len); 1968 rchan = packet_get_int(); 1969 rwindow = packet_get_int(); 1970 rmaxpack = packet_get_int(); 1971 1972 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1973 ctype, rchan, rwindow, rmaxpack); 1974 1975 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1976 c = client_request_forwarded_tcpip(ctype, rchan); 1977 } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) { 1978 c = client_request_forwarded_streamlocal(ctype, rchan); 1979 } else if (strcmp(ctype, "x11") == 0) { 1980 c = client_request_x11(ctype, rchan); 1981 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1982 c = client_request_agent(ctype, rchan); 1983 } 1984 /* XXX duplicate : */ 1985 if (c != NULL) { 1986 debug("confirm %s", ctype); 1987 c->remote_id = rchan; 1988 c->remote_window = rwindow; 1989 c->remote_maxpacket = rmaxpack; 1990 if (c->type != SSH_CHANNEL_CONNECTING) { 1991 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 1992 packet_put_int(c->remote_id); 1993 packet_put_int(c->self); 1994 packet_put_int(c->local_window); 1995 packet_put_int(c->local_maxpacket); 1996 packet_send(); 1997 } 1998 } else { 1999 debug("failure %s", ctype); 2000 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 2001 packet_put_int(rchan); 2002 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 2003 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 2004 packet_put_cstring("open failed"); 2005 packet_put_cstring(""); 2006 } 2007 packet_send(); 2008 } 2009 free(ctype); 2010 } 2011 static void 2012 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 2013 { 2014 Channel *c = NULL; 2015 int exitval, id, reply, success = 0; 2016 char *rtype; 2017 2018 id = packet_get_int(); 2019 rtype = packet_get_string(NULL); 2020 reply = packet_get_char(); 2021 2022 debug("client_input_channel_req: channel %d rtype %s reply %d", 2023 id, rtype, reply); 2024 2025 if (id == -1) { 2026 error("client_input_channel_req: request for channel -1"); 2027 } else if ((c = channel_lookup(id)) == NULL) { 2028 error("client_input_channel_req: channel %d: " 2029 "unknown channel", id); 2030 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 2031 packet_check_eom(); 2032 chan_rcvd_eow(c); 2033 } else if (strcmp(rtype, "exit-status") == 0) { 2034 exitval = packet_get_int(); 2035 if (c->ctl_chan != -1) { 2036 mux_exit_message(c, exitval); 2037 success = 1; 2038 } else if (id == session_ident) { 2039 /* Record exit value of local session */ 2040 success = 1; 2041 exit_status = exitval; 2042 } else { 2043 /* Probably for a mux channel that has already closed */ 2044 debug("%s: no sink for exit-status on channel %d", 2045 __func__, id); 2046 } 2047 packet_check_eom(); 2048 } 2049 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { 2050 packet_start(success ? 2051 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 2052 packet_put_int(c->remote_id); 2053 packet_send(); 2054 } 2055 free(rtype); 2056 } 2057 static void 2058 client_input_global_request(int type, u_int32_t seq, void *ctxt) 2059 { 2060 char *rtype; 2061 int want_reply; 2062 int success = 0; 2063 2064 rtype = packet_get_string(NULL); 2065 want_reply = packet_get_char(); 2066 debug("client_input_global_request: rtype %s want_reply %d", 2067 rtype, want_reply); 2068 if (want_reply) { 2069 packet_start(success ? 2070 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 2071 packet_send(); 2072 packet_write_wait(); 2073 } 2074 free(rtype); 2075 } 2076 2077 void 2078 client_session2_setup(int id, int want_tty, int want_subsystem, 2079 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 2080 { 2081 int len; 2082 Channel *c = NULL; 2083 2084 debug2("%s: id %d", __func__, id); 2085 2086 if ((c = channel_lookup(id)) == NULL) 2087 fatal("client_session2_setup: channel %d: unknown channel", id); 2088 2089 packet_set_interactive(want_tty, 2090 options.ip_qos_interactive, options.ip_qos_bulk); 2091 2092 if (want_tty) { 2093 struct winsize ws; 2094 2095 /* Store window size in the packet. */ 2096 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 2097 memset(&ws, 0, sizeof(ws)); 2098 2099 channel_request_start(id, "pty-req", 1); 2100 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); 2101 packet_put_cstring(term != NULL ? term : ""); 2102 packet_put_int((u_int)ws.ws_col); 2103 packet_put_int((u_int)ws.ws_row); 2104 packet_put_int((u_int)ws.ws_xpixel); 2105 packet_put_int((u_int)ws.ws_ypixel); 2106 if (tiop == NULL) 2107 tiop = get_saved_tio(); 2108 tty_make_modes(-1, tiop); 2109 packet_send(); 2110 /* XXX wait for reply */ 2111 c->client_tty = 1; 2112 } 2113 2114 /* Transfer any environment variables from client to server */ 2115 if (options.num_send_env != 0 && env != NULL) { 2116 int i, j, matched; 2117 char *name, *val; 2118 2119 debug("Sending environment."); 2120 for (i = 0; env[i] != NULL; i++) { 2121 /* Split */ 2122 name = xstrdup(env[i]); 2123 if ((val = strchr(name, '=')) == NULL) { 2124 free(name); 2125 continue; 2126 } 2127 *val++ = '\0'; 2128 2129 matched = 0; 2130 for (j = 0; j < options.num_send_env; j++) { 2131 if (match_pattern(name, options.send_env[j])) { 2132 matched = 1; 2133 break; 2134 } 2135 } 2136 if (!matched) { 2137 debug3("Ignored env %s", name); 2138 free(name); 2139 continue; 2140 } 2141 2142 debug("Sending env %s = %s", name, val); 2143 channel_request_start(id, "env", 0); 2144 packet_put_cstring(name); 2145 packet_put_cstring(val); 2146 packet_send(); 2147 free(name); 2148 } 2149 } 2150 2151 len = buffer_len(cmd); 2152 if (len > 0) { 2153 if (len > 900) 2154 len = 900; 2155 if (want_subsystem) { 2156 debug("Sending subsystem: %.*s", 2157 len, (u_char*)buffer_ptr(cmd)); 2158 channel_request_start(id, "subsystem", 1); 2159 client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); 2160 } else { 2161 debug("Sending command: %.*s", 2162 len, (u_char*)buffer_ptr(cmd)); 2163 channel_request_start(id, "exec", 1); 2164 client_expect_confirm(id, "exec", CONFIRM_CLOSE); 2165 } 2166 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 2167 packet_send(); 2168 } else { 2169 channel_request_start(id, "shell", 1); 2170 client_expect_confirm(id, "shell", CONFIRM_CLOSE); 2171 packet_send(); 2172 } 2173 } 2174 2175 static void 2176 client_init_dispatch_20(void) 2177 { 2178 dispatch_init(&dispatch_protocol_error); 2179 2180 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2181 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2182 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2183 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2184 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2185 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2186 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2187 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2188 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2189 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2190 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2191 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2192 2193 /* rekeying */ 2194 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2195 2196 /* global request reply messages */ 2197 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2198 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2199 } 2200 2201 static void 2202 client_init_dispatch_13(void) 2203 { 2204 dispatch_init(NULL); 2205 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2206 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2207 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2208 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2209 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2210 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2211 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2212 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2213 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2214 2215 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2216 &client_input_agent_open : &deny_input_open); 2217 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2218 &x11_input_open : &deny_input_open); 2219 } 2220 2221 static void 2222 client_init_dispatch_15(void) 2223 { 2224 client_init_dispatch_13(); 2225 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2226 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2227 } 2228 2229 static void 2230 client_init_dispatch(void) 2231 { 2232 if (compat20) 2233 client_init_dispatch_20(); 2234 else if (compat13) 2235 client_init_dispatch_13(); 2236 else 2237 client_init_dispatch_15(); 2238 } 2239 2240 void 2241 client_stop_mux(void) 2242 { 2243 if (options.control_path != NULL && muxserver_sock != -1) 2244 unlink(options.control_path); 2245 /* 2246 * If we are in persist mode, or don't have a shell, signal that we 2247 * should close when all active channels are closed. 2248 */ 2249 if (options.control_persist || no_shell_flag) { 2250 session_closed = 1; 2251 setproctitle("[stopped mux]"); 2252 } 2253 } 2254 2255 /* client specific fatal cleanup */ 2256 void 2257 cleanup_exit(int i) 2258 { 2259 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2260 leave_non_blocking(); 2261 if (options.control_path != NULL && muxserver_sock != -1) 2262 unlink(options.control_path); 2263 ssh_kill_proxy_command(); 2264 _exit(i); 2265 } 2266