1 /* $OpenBSD: clientloop.c,v 1.248 2013/01/02 00:32:07 djm Exp $ */ 2 /* $FreeBSD$ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * The main loop for the interactive session (client side). 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 * 15 * 16 * Copyright (c) 1999 Theo de Raadt. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 * 38 * 39 * SSH2 support added by Markus Friedl. 40 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 51 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 52 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 53 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 54 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 55 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 56 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 57 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 58 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 59 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 60 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 61 */ 62 63 #include "includes.h" 64 65 #include <sys/types.h> 66 #include <sys/ioctl.h> 67 #include <sys/param.h> 68 #ifdef HAVE_SYS_STAT_H 69 # include <sys/stat.h> 70 #endif 71 #ifdef HAVE_SYS_TIME_H 72 # include <sys/time.h> 73 #endif 74 #include <sys/socket.h> 75 76 #include <ctype.h> 77 #include <errno.h> 78 #ifdef HAVE_PATHS_H 79 #include <paths.h> 80 #endif 81 #include <signal.h> 82 #include <stdarg.h> 83 #include <stdio.h> 84 #include <stdlib.h> 85 #include <string.h> 86 #include <termios.h> 87 #include <pwd.h> 88 #include <unistd.h> 89 90 #include "openbsd-compat/sys-queue.h" 91 #include "xmalloc.h" 92 #include "ssh.h" 93 #include "ssh1.h" 94 #include "ssh2.h" 95 #include "packet.h" 96 #include "buffer.h" 97 #include "compat.h" 98 #include "channels.h" 99 #include "dispatch.h" 100 #include "key.h" 101 #include "cipher.h" 102 #include "kex.h" 103 #include "log.h" 104 #include "readconf.h" 105 #include "clientloop.h" 106 #include "sshconnect.h" 107 #include "authfd.h" 108 #include "atomicio.h" 109 #include "sshpty.h" 110 #include "misc.h" 111 #include "match.h" 112 #include "msg.h" 113 #include "roaming.h" 114 115 /* import options */ 116 extern Options options; 117 118 /* Flag indicating that stdin should be redirected from /dev/null. */ 119 extern int stdin_null_flag; 120 121 /* Flag indicating that no shell has been requested */ 122 extern int no_shell_flag; 123 124 /* Control socket */ 125 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 126 127 /* 128 * Name of the host we are connecting to. This is the name given on the 129 * command line, or the HostName specified for the user-supplied name in a 130 * configuration file. 131 */ 132 extern char *host; 133 134 /* 135 * Flag to indicate that we have received a window change signal which has 136 * not yet been processed. This will cause a message indicating the new 137 * window size to be sent to the server a little later. This is volatile 138 * because this is updated in a signal handler. 139 */ 140 static volatile sig_atomic_t received_window_change_signal = 0; 141 static volatile sig_atomic_t received_signal = 0; 142 143 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 144 static int in_non_blocking_mode = 0; 145 146 /* Time when backgrounded control master using ControlPersist should exit */ 147 static time_t control_persist_exit_time = 0; 148 149 /* Common data for the client loop code. */ 150 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 151 static int escape_char1; /* Escape character. (proto1 only) */ 152 static int escape_pending1; /* Last character was an escape (proto1 only) */ 153 static int last_was_cr; /* Last character was a newline. */ 154 static int exit_status; /* Used to store the command exit status. */ 155 static int stdin_eof; /* EOF has been encountered on stderr. */ 156 static Buffer stdin_buffer; /* Buffer for stdin data. */ 157 static Buffer stdout_buffer; /* Buffer for stdout data. */ 158 static Buffer stderr_buffer; /* Buffer for stderr data. */ 159 static u_int buffer_high; /* Soft max buffer size. */ 160 static int connection_in; /* Connection to server (input). */ 161 static int connection_out; /* Connection to server (output). */ 162 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 163 static int session_closed; /* In SSH2: login session closed. */ 164 static int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 165 166 static void client_init_dispatch(void); 167 int session_ident = -1; 168 169 int session_resumed = 0; 170 171 /* Track escape per proto2 channel */ 172 struct escape_filter_ctx { 173 int escape_pending; 174 int escape_char; 175 }; 176 177 /* Context for channel confirmation replies */ 178 struct channel_reply_ctx { 179 const char *request_type; 180 int id; 181 enum confirm_action action; 182 }; 183 184 /* Global request success/failure callbacks */ 185 struct global_confirm { 186 TAILQ_ENTRY(global_confirm) entry; 187 global_confirm_cb *cb; 188 void *ctx; 189 int ref_count; 190 }; 191 TAILQ_HEAD(global_confirms, global_confirm); 192 static struct global_confirms global_confirms = 193 TAILQ_HEAD_INITIALIZER(global_confirms); 194 195 /*XXX*/ 196 extern Kex *xxx_kex; 197 198 void ssh_process_session2_setup(int, int, int, Buffer *); 199 200 /* Restores stdin to blocking mode. */ 201 202 static void 203 leave_non_blocking(void) 204 { 205 if (in_non_blocking_mode) { 206 unset_nonblock(fileno(stdin)); 207 in_non_blocking_mode = 0; 208 } 209 } 210 211 /* Puts stdin terminal in non-blocking mode. */ 212 213 static void 214 enter_non_blocking(void) 215 { 216 in_non_blocking_mode = 1; 217 set_nonblock(fileno(stdin)); 218 } 219 220 /* 221 * Signal handler for the window change signal (SIGWINCH). This just sets a 222 * flag indicating that the window has changed. 223 */ 224 /*ARGSUSED */ 225 static void 226 window_change_handler(int sig) 227 { 228 received_window_change_signal = 1; 229 signal(SIGWINCH, window_change_handler); 230 } 231 232 /* 233 * Signal handler for signals that cause the program to terminate. These 234 * signals must be trapped to restore terminal modes. 235 */ 236 /*ARGSUSED */ 237 static void 238 signal_handler(int sig) 239 { 240 received_signal = sig; 241 quit_pending = 1; 242 } 243 244 /* 245 * Returns current time in seconds from Jan 1, 1970 with the maximum 246 * available resolution. 247 */ 248 249 static double 250 get_current_time(void) 251 { 252 struct timeval tv; 253 gettimeofday(&tv, NULL); 254 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 255 } 256 257 /* 258 * Sets control_persist_exit_time to the absolute time when the 259 * backgrounded control master should exit due to expiry of the 260 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded 261 * control master process, or if there is no ControlPersist timeout. 262 */ 263 static void 264 set_control_persist_exit_time(void) 265 { 266 if (muxserver_sock == -1 || !options.control_persist 267 || options.control_persist_timeout == 0) { 268 /* not using a ControlPersist timeout */ 269 control_persist_exit_time = 0; 270 } else if (channel_still_open()) { 271 /* some client connections are still open */ 272 if (control_persist_exit_time > 0) 273 debug2("%s: cancel scheduled exit", __func__); 274 control_persist_exit_time = 0; 275 } else if (control_persist_exit_time <= 0) { 276 /* a client connection has recently closed */ 277 control_persist_exit_time = time(NULL) + 278 (time_t)options.control_persist_timeout; 279 debug2("%s: schedule exit in %d seconds", __func__, 280 options.control_persist_timeout); 281 } 282 /* else we are already counting down to the timeout */ 283 } 284 285 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" 286 static int 287 client_x11_display_valid(const char *display) 288 { 289 size_t i, dlen; 290 291 dlen = strlen(display); 292 for (i = 0; i < dlen; i++) { 293 if (!isalnum(display[i]) && 294 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 295 debug("Invalid character '%c' in DISPLAY", display[i]); 296 return 0; 297 } 298 } 299 return 1; 300 } 301 302 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 303 void 304 client_x11_get_proto(const char *display, const char *xauth_path, 305 u_int trusted, u_int timeout, char **_proto, char **_data) 306 { 307 char cmd[1024]; 308 char line[512]; 309 char xdisplay[512]; 310 static char proto[512], data[512]; 311 FILE *f; 312 int got_data = 0, generated = 0, do_unlink = 0, i; 313 char *xauthdir, *xauthfile; 314 struct stat st; 315 u_int now; 316 317 xauthdir = xauthfile = NULL; 318 *_proto = proto; 319 *_data = data; 320 proto[0] = data[0] = '\0'; 321 322 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 323 debug("No xauth program."); 324 } else if (!client_x11_display_valid(display)) { 325 logit("DISPLAY '%s' invalid, falling back to fake xauth data", 326 display); 327 } else { 328 if (display == NULL) { 329 debug("x11_get_proto: DISPLAY not set"); 330 return; 331 } 332 /* 333 * Handle FamilyLocal case where $DISPLAY does 334 * not match an authorization entry. For this we 335 * just try "xauth list unix:displaynum.screennum". 336 * XXX: "localhost" match to determine FamilyLocal 337 * is not perfect. 338 */ 339 if (strncmp(display, "localhost:", 10) == 0) { 340 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 341 display + 10); 342 display = xdisplay; 343 } 344 if (trusted == 0) { 345 xauthdir = xmalloc(MAXPATHLEN); 346 xauthfile = xmalloc(MAXPATHLEN); 347 mktemp_proto(xauthdir, MAXPATHLEN); 348 if (mkdtemp(xauthdir) != NULL) { 349 do_unlink = 1; 350 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", 351 xauthdir); 352 snprintf(cmd, sizeof(cmd), 353 "%s -f %s generate %s " SSH_X11_PROTO 354 " untrusted timeout %u 2>" _PATH_DEVNULL, 355 xauth_path, xauthfile, display, timeout); 356 debug2("x11_get_proto: %s", cmd); 357 if (system(cmd) == 0) 358 generated = 1; 359 if (x11_refuse_time == 0) { 360 now = time(NULL) + 1; 361 if (UINT_MAX - timeout < now) 362 x11_refuse_time = UINT_MAX; 363 else 364 x11_refuse_time = now + timeout; 365 } 366 } 367 } 368 369 /* 370 * When in untrusted mode, we read the cookie only if it was 371 * successfully generated as an untrusted one in the step 372 * above. 373 */ 374 if (trusted || generated) { 375 snprintf(cmd, sizeof(cmd), 376 "%s %s%s list %s 2>" _PATH_DEVNULL, 377 xauth_path, 378 generated ? "-f " : "" , 379 generated ? xauthfile : "", 380 display); 381 debug2("x11_get_proto: %s", cmd); 382 f = popen(cmd, "r"); 383 if (f && fgets(line, sizeof(line), f) && 384 sscanf(line, "%*s %511s %511s", proto, data) == 2) 385 got_data = 1; 386 if (f) 387 pclose(f); 388 } else 389 error("Warning: untrusted X11 forwarding setup failed: " 390 "xauth key data not generated"); 391 } 392 393 if (do_unlink) { 394 unlink(xauthfile); 395 rmdir(xauthdir); 396 } 397 if (xauthdir) 398 xfree(xauthdir); 399 if (xauthfile) 400 xfree(xauthfile); 401 402 /* 403 * If we didn't get authentication data, just make up some 404 * data. The forwarding code will check the validity of the 405 * response anyway, and substitute this data. The X11 406 * server, however, will ignore this fake data and use 407 * whatever authentication mechanisms it was using otherwise 408 * for the local connection. 409 */ 410 if (!got_data) { 411 u_int32_t rnd = 0; 412 413 logit("Warning: No xauth data; " 414 "using fake authentication data for X11 forwarding."); 415 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 416 for (i = 0; i < 16; i++) { 417 if (i % 4 == 0) 418 rnd = arc4random(); 419 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 420 rnd & 0xff); 421 rnd >>= 8; 422 } 423 } 424 } 425 426 /* 427 * This is called when the interactive is entered. This checks if there is 428 * an EOF coming on stdin. We must check this explicitly, as select() does 429 * not appear to wake up when redirecting from /dev/null. 430 */ 431 432 static void 433 client_check_initial_eof_on_stdin(void) 434 { 435 int len; 436 char buf[1]; 437 438 /* 439 * If standard input is to be "redirected from /dev/null", we simply 440 * mark that we have seen an EOF and send an EOF message to the 441 * server. Otherwise, we try to read a single character; it appears 442 * that for some files, such /dev/null, select() never wakes up for 443 * read for this descriptor, which means that we never get EOF. This 444 * way we will get the EOF if stdin comes from /dev/null or similar. 445 */ 446 if (stdin_null_flag) { 447 /* Fake EOF on stdin. */ 448 debug("Sending eof."); 449 stdin_eof = 1; 450 packet_start(SSH_CMSG_EOF); 451 packet_send(); 452 } else { 453 enter_non_blocking(); 454 455 /* Check for immediate EOF on stdin. */ 456 len = read(fileno(stdin), buf, 1); 457 if (len == 0) { 458 /* 459 * EOF. Record that we have seen it and send 460 * EOF to server. 461 */ 462 debug("Sending eof."); 463 stdin_eof = 1; 464 packet_start(SSH_CMSG_EOF); 465 packet_send(); 466 } else if (len > 0) { 467 /* 468 * Got data. We must store the data in the buffer, 469 * and also process it as an escape character if 470 * appropriate. 471 */ 472 if ((u_char) buf[0] == escape_char1) 473 escape_pending1 = 1; 474 else 475 buffer_append(&stdin_buffer, buf, 1); 476 } 477 leave_non_blocking(); 478 } 479 } 480 481 482 /* 483 * Make packets from buffered stdin data, and buffer them for sending to the 484 * connection. 485 */ 486 487 static void 488 client_make_packets_from_stdin_data(void) 489 { 490 u_int len; 491 492 /* Send buffered stdin data to the server. */ 493 while (buffer_len(&stdin_buffer) > 0 && 494 packet_not_very_much_data_to_write()) { 495 len = buffer_len(&stdin_buffer); 496 /* Keep the packets at reasonable size. */ 497 if (len > packet_get_maxsize()) 498 len = packet_get_maxsize(); 499 packet_start(SSH_CMSG_STDIN_DATA); 500 packet_put_string(buffer_ptr(&stdin_buffer), len); 501 packet_send(); 502 buffer_consume(&stdin_buffer, len); 503 /* If we have a pending EOF, send it now. */ 504 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 505 packet_start(SSH_CMSG_EOF); 506 packet_send(); 507 } 508 } 509 } 510 511 /* 512 * Checks if the client window has changed, and sends a packet about it to 513 * the server if so. The actual change is detected elsewhere (by a software 514 * interrupt on Unix); this just checks the flag and sends a message if 515 * appropriate. 516 */ 517 518 static void 519 client_check_window_change(void) 520 { 521 struct winsize ws; 522 523 if (! received_window_change_signal) 524 return; 525 /** XXX race */ 526 received_window_change_signal = 0; 527 528 debug2("client_check_window_change: changed"); 529 530 if (compat20) { 531 channel_send_window_changes(); 532 } else { 533 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 534 return; 535 packet_start(SSH_CMSG_WINDOW_SIZE); 536 packet_put_int((u_int)ws.ws_row); 537 packet_put_int((u_int)ws.ws_col); 538 packet_put_int((u_int)ws.ws_xpixel); 539 packet_put_int((u_int)ws.ws_ypixel); 540 packet_send(); 541 } 542 } 543 544 static void 545 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 546 { 547 struct global_confirm *gc; 548 549 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 550 return; 551 if (gc->cb != NULL) 552 gc->cb(type, seq, gc->ctx); 553 if (--gc->ref_count <= 0) { 554 TAILQ_REMOVE(&global_confirms, gc, entry); 555 bzero(gc, sizeof(*gc)); 556 xfree(gc); 557 } 558 559 packet_set_alive_timeouts(0); 560 } 561 562 static void 563 server_alive_check(void) 564 { 565 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 566 logit("Timeout, server %s not responding.", host); 567 cleanup_exit(255); 568 } 569 packet_start(SSH2_MSG_GLOBAL_REQUEST); 570 packet_put_cstring("keepalive@openssh.com"); 571 packet_put_char(1); /* boolean: want reply */ 572 packet_send(); 573 /* Insert an empty placeholder to maintain ordering */ 574 client_register_global_confirm(NULL, NULL); 575 } 576 577 /* 578 * Waits until the client can do something (some data becomes available on 579 * one of the file descriptors). 580 */ 581 static void 582 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 583 int *maxfdp, u_int *nallocp, int rekeying) 584 { 585 struct timeval tv, *tvp; 586 int timeout_secs; 587 time_t minwait_secs = 0; 588 int ret; 589 590 /* Add any selections by the channel mechanism. */ 591 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 592 &minwait_secs, rekeying); 593 594 if (!compat20) { 595 /* Read from the connection, unless our buffers are full. */ 596 if (buffer_len(&stdout_buffer) < buffer_high && 597 buffer_len(&stderr_buffer) < buffer_high && 598 channel_not_very_much_buffered_data()) 599 FD_SET(connection_in, *readsetp); 600 /* 601 * Read from stdin, unless we have seen EOF or have very much 602 * buffered data to send to the server. 603 */ 604 if (!stdin_eof && packet_not_very_much_data_to_write()) 605 FD_SET(fileno(stdin), *readsetp); 606 607 /* Select stdout/stderr if have data in buffer. */ 608 if (buffer_len(&stdout_buffer) > 0) 609 FD_SET(fileno(stdout), *writesetp); 610 if (buffer_len(&stderr_buffer) > 0) 611 FD_SET(fileno(stderr), *writesetp); 612 } else { 613 /* channel_prepare_select could have closed the last channel */ 614 if (session_closed && !channel_still_open() && 615 !packet_have_data_to_write()) { 616 /* clear mask since we did not call select() */ 617 memset(*readsetp, 0, *nallocp); 618 memset(*writesetp, 0, *nallocp); 619 return; 620 } else { 621 FD_SET(connection_in, *readsetp); 622 } 623 } 624 625 /* Select server connection if have data to write to the server. */ 626 if (packet_have_data_to_write()) 627 FD_SET(connection_out, *writesetp); 628 629 /* 630 * Wait for something to happen. This will suspend the process until 631 * some selected descriptor can be read, written, or has some other 632 * event pending, or a timeout expires. 633 */ 634 635 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 636 if (options.server_alive_interval > 0 && compat20) 637 timeout_secs = options.server_alive_interval; 638 set_control_persist_exit_time(); 639 if (control_persist_exit_time > 0) { 640 timeout_secs = MIN(timeout_secs, 641 control_persist_exit_time - time(NULL)); 642 if (timeout_secs < 0) 643 timeout_secs = 0; 644 } 645 if (minwait_secs != 0) 646 timeout_secs = MIN(timeout_secs, (int)minwait_secs); 647 if (timeout_secs == INT_MAX) 648 tvp = NULL; 649 else { 650 tv.tv_sec = timeout_secs; 651 tv.tv_usec = 0; 652 tvp = &tv; 653 } 654 655 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 656 if (ret < 0) { 657 char buf[100]; 658 659 /* 660 * We have to clear the select masks, because we return. 661 * We have to return, because the mainloop checks for the flags 662 * set by the signal handlers. 663 */ 664 memset(*readsetp, 0, *nallocp); 665 memset(*writesetp, 0, *nallocp); 666 667 if (errno == EINTR) 668 return; 669 /* Note: we might still have data in the buffers. */ 670 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 671 buffer_append(&stderr_buffer, buf, strlen(buf)); 672 quit_pending = 1; 673 } else if (ret == 0) 674 server_alive_check(); 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[SSH_IOBUFSZ]; 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 && 742 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 743 len = 0; 744 745 if (len < 0) { 746 /* 747 * An error has encountered. Perhaps there is a 748 * network problem. 749 */ 750 snprintf(buf, sizeof buf, 751 "Read from remote host %.300s: %.100s\r\n", 752 host, strerror(errno)); 753 buffer_append(&stderr_buffer, buf, strlen(buf)); 754 quit_pending = 1; 755 return; 756 } 757 packet_process_incoming(buf, len); 758 } 759 } 760 761 static void 762 client_status_confirm(int type, Channel *c, void *ctx) 763 { 764 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 765 char errmsg[256]; 766 int tochan; 767 768 /* 769 * If a TTY was explicitly requested, then a failure to allocate 770 * one is fatal. 771 */ 772 if (cr->action == CONFIRM_TTY && 773 (options.request_tty == REQUEST_TTY_FORCE || 774 options.request_tty == REQUEST_TTY_YES)) 775 cr->action = CONFIRM_CLOSE; 776 777 /* XXX supress on mux _client_ quietmode */ 778 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 779 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 780 781 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 782 debug2("%s request accepted on channel %d", 783 cr->request_type, c->self); 784 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 785 if (tochan) { 786 snprintf(errmsg, sizeof(errmsg), 787 "%s request failed\r\n", cr->request_type); 788 } else { 789 snprintf(errmsg, sizeof(errmsg), 790 "%s request failed on channel %d", 791 cr->request_type, c->self); 792 } 793 /* If error occurred on primary session channel, then exit */ 794 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 795 fatal("%s", errmsg); 796 /* 797 * If error occurred on mux client, append to 798 * their stderr. 799 */ 800 if (tochan) { 801 buffer_append(&c->extended, errmsg, 802 strlen(errmsg)); 803 } else 804 error("%s", errmsg); 805 if (cr->action == CONFIRM_TTY) { 806 /* 807 * If a TTY allocation error occurred, then arrange 808 * for the correct TTY to leave raw mode. 809 */ 810 if (c->self == session_ident) 811 leave_raw_mode(0); 812 else 813 mux_tty_alloc_failed(c); 814 } else if (cr->action == CONFIRM_CLOSE) { 815 chan_read_failed(c); 816 chan_write_failed(c); 817 } 818 } 819 xfree(cr); 820 } 821 822 static void 823 client_abandon_status_confirm(Channel *c, void *ctx) 824 { 825 xfree(ctx); 826 } 827 828 void 829 client_expect_confirm(int id, const char *request, 830 enum confirm_action action) 831 { 832 struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); 833 834 cr->request_type = request; 835 cr->action = action; 836 837 channel_register_status_confirm(id, client_status_confirm, 838 client_abandon_status_confirm, cr); 839 } 840 841 void 842 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 843 { 844 struct global_confirm *gc, *last_gc; 845 846 /* Coalesce identical callbacks */ 847 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 848 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 849 if (++last_gc->ref_count >= INT_MAX) 850 fatal("%s: last_gc->ref_count = %d", 851 __func__, last_gc->ref_count); 852 return; 853 } 854 855 gc = xmalloc(sizeof(*gc)); 856 gc->cb = cb; 857 gc->ctx = ctx; 858 gc->ref_count = 1; 859 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 860 } 861 862 static void 863 process_cmdline(void) 864 { 865 void (*handler)(int); 866 char *s, *cmd, *cancel_host; 867 int delete = 0, local = 0, remote = 0, dynamic = 0; 868 int cancel_port, ok; 869 Forward fwd; 870 871 bzero(&fwd, sizeof(fwd)); 872 fwd.listen_host = fwd.connect_host = NULL; 873 874 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 875 handler = signal(SIGINT, SIG_IGN); 876 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 877 if (s == NULL) 878 goto out; 879 while (isspace(*s)) 880 s++; 881 if (*s == '-') 882 s++; /* Skip cmdline '-', if any */ 883 if (*s == '\0') 884 goto out; 885 886 if (*s == 'h' || *s == 'H' || *s == '?') { 887 logit("Commands:"); 888 logit(" -L[bind_address:]port:host:hostport " 889 "Request local forward"); 890 logit(" -R[bind_address:]port:host:hostport " 891 "Request remote forward"); 892 logit(" -D[bind_address:]port " 893 "Request dynamic forward"); 894 logit(" -KL[bind_address:]port " 895 "Cancel local forward"); 896 logit(" -KR[bind_address:]port " 897 "Cancel remote forward"); 898 logit(" -KD[bind_address:]port " 899 "Cancel dynamic forward"); 900 if (!options.permit_local_command) 901 goto out; 902 logit(" !args " 903 "Execute local command"); 904 goto out; 905 } 906 907 if (*s == '!' && options.permit_local_command) { 908 s++; 909 ssh_local_cmd(s); 910 goto out; 911 } 912 913 if (*s == 'K') { 914 delete = 1; 915 s++; 916 } 917 if (*s == 'L') 918 local = 1; 919 else if (*s == 'R') 920 remote = 1; 921 else if (*s == 'D') 922 dynamic = 1; 923 else { 924 logit("Invalid command."); 925 goto out; 926 } 927 928 if (delete && !compat20) { 929 logit("Not supported for SSH protocol version 1."); 930 goto out; 931 } 932 933 while (isspace(*++s)) 934 ; 935 936 /* XXX update list of forwards in options */ 937 if (delete) { 938 cancel_port = 0; 939 cancel_host = hpdelim(&s); /* may be NULL */ 940 if (s != NULL) { 941 cancel_port = a2port(s); 942 cancel_host = cleanhostname(cancel_host); 943 } else { 944 cancel_port = a2port(cancel_host); 945 cancel_host = NULL; 946 } 947 if (cancel_port <= 0) { 948 logit("Bad forwarding close port"); 949 goto out; 950 } 951 if (remote) 952 ok = channel_request_rforward_cancel(cancel_host, 953 cancel_port) == 0; 954 else if (dynamic) 955 ok = channel_cancel_lport_listener(cancel_host, 956 cancel_port, 0, options.gateway_ports) > 0; 957 else 958 ok = channel_cancel_lport_listener(cancel_host, 959 cancel_port, CHANNEL_CANCEL_PORT_STATIC, 960 options.gateway_ports) > 0; 961 if (!ok) { 962 logit("Unkown port forwarding."); 963 goto out; 964 } 965 logit("Canceled forwarding."); 966 } else { 967 if (!parse_forward(&fwd, s, dynamic, remote)) { 968 logit("Bad forwarding specification."); 969 goto out; 970 } 971 if (local || dynamic) { 972 if (!channel_setup_local_fwd_listener(fwd.listen_host, 973 fwd.listen_port, fwd.connect_host, 974 fwd.connect_port, options.gateway_ports)) { 975 logit("Port forwarding failed."); 976 goto out; 977 } 978 } else { 979 if (channel_request_remote_forwarding(fwd.listen_host, 980 fwd.listen_port, fwd.connect_host, 981 fwd.connect_port) < 0) { 982 logit("Port forwarding failed."); 983 goto out; 984 } 985 } 986 logit("Forwarding port."); 987 } 988 989 out: 990 signal(SIGINT, handler); 991 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 992 if (cmd) 993 xfree(cmd); 994 if (fwd.listen_host != NULL) 995 xfree(fwd.listen_host); 996 if (fwd.connect_host != NULL) 997 xfree(fwd.connect_host); 998 } 999 1000 /* reasons to suppress output of an escape command in help output */ 1001 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 1002 #define SUPPRESS_PROTO1 1 /* don't show in protocol 1 sessions */ 1003 #define SUPPRESS_MUXCLIENT 2 /* don't show in mux client sessions */ 1004 #define SUPPRESS_MUXMASTER 4 /* don't show in mux master sessions */ 1005 #define SUPPRESS_SYSLOG 8 /* don't show when logging to syslog */ 1006 struct escape_help_text { 1007 const char *cmd; 1008 const char *text; 1009 unsigned int flags; 1010 }; 1011 static struct escape_help_text esc_txt[] = { 1012 {".", "terminate session", SUPPRESS_MUXMASTER}, 1013 {".", "terminate connection (and any multiplexed sessions)", 1014 SUPPRESS_MUXCLIENT}, 1015 {"B", "send a BREAK to the remote system", SUPPRESS_PROTO1}, 1016 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 1017 {"R", "request rekey", SUPPRESS_PROTO1}, 1018 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 1019 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 1020 {"#", "list forwarded connections", SUPPRESS_NEVER}, 1021 {"&", "background ssh (when waiting for connections to terminate)", 1022 SUPPRESS_MUXCLIENT}, 1023 {"?", "this message", SUPPRESS_NEVER}, 1024 }; 1025 1026 static void 1027 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client, 1028 int using_stderr) 1029 { 1030 unsigned int i, suppress_flags; 1031 char string[1024]; 1032 1033 snprintf(string, sizeof string, "%c?\r\n" 1034 "Supported escape sequences:\r\n", escape_char); 1035 buffer_append(b, string, strlen(string)); 1036 1037 suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) | 1038 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 1039 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 1040 (using_stderr ? 0 : SUPPRESS_SYSLOG); 1041 1042 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 1043 if (esc_txt[i].flags & suppress_flags) 1044 continue; 1045 snprintf(string, sizeof string, " %c%-3s - %s\r\n", 1046 escape_char, esc_txt[i].cmd, esc_txt[i].text); 1047 buffer_append(b, string, strlen(string)); 1048 } 1049 1050 snprintf(string, sizeof string, 1051 " %c%c - send the escape character by typing it twice\r\n" 1052 "(Note that escapes are only recognized immediately after " 1053 "newline.)\r\n", escape_char, escape_char); 1054 buffer_append(b, string, strlen(string)); 1055 } 1056 1057 /* 1058 * Process the characters one by one, call with c==NULL for proto1 case. 1059 */ 1060 static int 1061 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 1062 char *buf, int len) 1063 { 1064 char string[1024]; 1065 pid_t pid; 1066 int bytes = 0; 1067 u_int i; 1068 u_char ch; 1069 char *s; 1070 int *escape_pendingp, escape_char; 1071 struct escape_filter_ctx *efc; 1072 1073 if (c == NULL) { 1074 escape_pendingp = &escape_pending1; 1075 escape_char = escape_char1; 1076 } else { 1077 if (c->filter_ctx == NULL) 1078 return 0; 1079 efc = (struct escape_filter_ctx *)c->filter_ctx; 1080 escape_pendingp = &efc->escape_pending; 1081 escape_char = efc->escape_char; 1082 } 1083 1084 if (len <= 0) 1085 return (0); 1086 1087 for (i = 0; i < (u_int)len; i++) { 1088 /* Get one character at a time. */ 1089 ch = buf[i]; 1090 1091 if (*escape_pendingp) { 1092 /* We have previously seen an escape character. */ 1093 /* Clear the flag now. */ 1094 *escape_pendingp = 0; 1095 1096 /* Process the escaped character. */ 1097 switch (ch) { 1098 case '.': 1099 /* Terminate the connection. */ 1100 snprintf(string, sizeof string, "%c.\r\n", 1101 escape_char); 1102 buffer_append(berr, string, strlen(string)); 1103 1104 if (c && c->ctl_chan != -1) { 1105 chan_read_failed(c); 1106 chan_write_failed(c); 1107 mux_master_session_cleanup_cb(c->self, 1108 NULL); 1109 return 0; 1110 } else 1111 quit_pending = 1; 1112 return -1; 1113 1114 case 'Z' - 64: 1115 /* XXX support this for mux clients */ 1116 if (c && c->ctl_chan != -1) { 1117 char b[16]; 1118 noescape: 1119 if (ch == 'Z' - 64) 1120 snprintf(b, sizeof b, "^Z"); 1121 else 1122 snprintf(b, sizeof b, "%c", ch); 1123 snprintf(string, sizeof string, 1124 "%c%s escape not available to " 1125 "multiplexed sessions\r\n", 1126 escape_char, b); 1127 buffer_append(berr, string, 1128 strlen(string)); 1129 continue; 1130 } 1131 /* Suspend the program. Inform the user */ 1132 snprintf(string, sizeof string, 1133 "%c^Z [suspend ssh]\r\n", escape_char); 1134 buffer_append(berr, string, strlen(string)); 1135 1136 /* Restore terminal modes and suspend. */ 1137 client_suspend_self(bin, bout, berr); 1138 1139 /* We have been continued. */ 1140 continue; 1141 1142 case 'B': 1143 if (compat20) { 1144 snprintf(string, sizeof string, 1145 "%cB\r\n", escape_char); 1146 buffer_append(berr, string, 1147 strlen(string)); 1148 channel_request_start(session_ident, 1149 "break", 0); 1150 packet_put_int(1000); 1151 packet_send(); 1152 } 1153 continue; 1154 1155 case 'R': 1156 if (compat20) { 1157 if (datafellows & SSH_BUG_NOREKEY) 1158 logit("Server does not " 1159 "support re-keying"); 1160 else 1161 need_rekeying = 1; 1162 } 1163 continue; 1164 1165 case 'V': 1166 /* FALLTHROUGH */ 1167 case 'v': 1168 if (c && c->ctl_chan != -1) 1169 goto noescape; 1170 if (!log_is_on_stderr()) { 1171 snprintf(string, sizeof string, 1172 "%c%c [Logging to syslog]\r\n", 1173 escape_char, ch); 1174 buffer_append(berr, string, 1175 strlen(string)); 1176 continue; 1177 } 1178 if (ch == 'V' && options.log_level > 1179 SYSLOG_LEVEL_QUIET) 1180 log_change_level(--options.log_level); 1181 if (ch == 'v' && options.log_level < 1182 SYSLOG_LEVEL_DEBUG3) 1183 log_change_level(++options.log_level); 1184 snprintf(string, sizeof string, 1185 "%c%c [LogLevel %s]\r\n", escape_char, ch, 1186 log_level_name(options.log_level)); 1187 buffer_append(berr, string, strlen(string)); 1188 continue; 1189 1190 case '&': 1191 if (c && c->ctl_chan != -1) 1192 goto noescape; 1193 /* 1194 * Detach the program (continue to serve 1195 * connections, but put in background and no 1196 * more new connections). 1197 */ 1198 /* Restore tty modes. */ 1199 leave_raw_mode( 1200 options.request_tty == REQUEST_TTY_FORCE); 1201 1202 /* Stop listening for new connections. */ 1203 channel_stop_listening(); 1204 1205 snprintf(string, sizeof string, 1206 "%c& [backgrounded]\n", escape_char); 1207 buffer_append(berr, string, strlen(string)); 1208 1209 /* Fork into background. */ 1210 pid = fork(); 1211 if (pid < 0) { 1212 error("fork: %.100s", strerror(errno)); 1213 continue; 1214 } 1215 if (pid != 0) { /* This is the parent. */ 1216 /* The parent just exits. */ 1217 exit(0); 1218 } 1219 /* The child continues serving connections. */ 1220 if (compat20) { 1221 buffer_append(bin, "\004", 1); 1222 /* fake EOF on stdin */ 1223 return -1; 1224 } else if (!stdin_eof) { 1225 /* 1226 * Sending SSH_CMSG_EOF alone does not 1227 * always appear to be enough. So we 1228 * try to send an EOF character first. 1229 */ 1230 packet_start(SSH_CMSG_STDIN_DATA); 1231 packet_put_string("\004", 1); 1232 packet_send(); 1233 /* Close stdin. */ 1234 stdin_eof = 1; 1235 if (buffer_len(bin) == 0) { 1236 packet_start(SSH_CMSG_EOF); 1237 packet_send(); 1238 } 1239 } 1240 continue; 1241 1242 case '?': 1243 print_escape_help(berr, escape_char, compat20, 1244 (c && c->ctl_chan != -1), 1245 log_is_on_stderr()); 1246 continue; 1247 1248 case '#': 1249 snprintf(string, sizeof string, "%c#\r\n", 1250 escape_char); 1251 buffer_append(berr, string, strlen(string)); 1252 s = channel_open_message(); 1253 buffer_append(berr, s, strlen(s)); 1254 xfree(s); 1255 continue; 1256 1257 case 'C': 1258 if (c && c->ctl_chan != -1) 1259 goto noescape; 1260 process_cmdline(); 1261 continue; 1262 1263 default: 1264 if (ch != escape_char) { 1265 buffer_put_char(bin, escape_char); 1266 bytes++; 1267 } 1268 /* Escaped characters fall through here */ 1269 break; 1270 } 1271 } else { 1272 /* 1273 * The previous character was not an escape char. 1274 * Check if this is an escape. 1275 */ 1276 if (last_was_cr && ch == escape_char) { 1277 /* 1278 * It is. Set the flag and continue to 1279 * next character. 1280 */ 1281 *escape_pendingp = 1; 1282 continue; 1283 } 1284 } 1285 1286 /* 1287 * Normal character. Record whether it was a newline, 1288 * and append it to the buffer. 1289 */ 1290 last_was_cr = (ch == '\r' || ch == '\n'); 1291 buffer_put_char(bin, ch); 1292 bytes++; 1293 } 1294 return bytes; 1295 } 1296 1297 static void 1298 client_process_input(fd_set *readset) 1299 { 1300 int len; 1301 char buf[SSH_IOBUFSZ]; 1302 1303 /* Read input from stdin. */ 1304 if (FD_ISSET(fileno(stdin), readset)) { 1305 /* Read as much as possible. */ 1306 len = read(fileno(stdin), buf, sizeof(buf)); 1307 if (len < 0 && 1308 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1309 return; /* we'll try again later */ 1310 if (len <= 0) { 1311 /* 1312 * Received EOF or error. They are treated 1313 * similarly, except that an error message is printed 1314 * if it was an error condition. 1315 */ 1316 if (len < 0) { 1317 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1318 strerror(errno)); 1319 buffer_append(&stderr_buffer, buf, strlen(buf)); 1320 } 1321 /* Mark that we have seen EOF. */ 1322 stdin_eof = 1; 1323 /* 1324 * Send an EOF message to the server unless there is 1325 * data in the buffer. If there is data in the 1326 * buffer, no message will be sent now. Code 1327 * elsewhere will send the EOF when the buffer 1328 * becomes empty if stdin_eof is set. 1329 */ 1330 if (buffer_len(&stdin_buffer) == 0) { 1331 packet_start(SSH_CMSG_EOF); 1332 packet_send(); 1333 } 1334 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1335 /* 1336 * Normal successful read, and no escape character. 1337 * Just append the data to buffer. 1338 */ 1339 buffer_append(&stdin_buffer, buf, len); 1340 } else { 1341 /* 1342 * Normal, successful read. But we have an escape 1343 * character and have to process the characters one 1344 * by one. 1345 */ 1346 if (process_escapes(NULL, &stdin_buffer, 1347 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1348 return; 1349 } 1350 } 1351 } 1352 1353 static void 1354 client_process_output(fd_set *writeset) 1355 { 1356 int len; 1357 char buf[100]; 1358 1359 /* Write buffered output to stdout. */ 1360 if (FD_ISSET(fileno(stdout), writeset)) { 1361 /* Write as much data as possible. */ 1362 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1363 buffer_len(&stdout_buffer)); 1364 if (len <= 0) { 1365 if (errno == EINTR || errno == EAGAIN || 1366 errno == EWOULDBLOCK) 1367 len = 0; 1368 else { 1369 /* 1370 * An error or EOF was encountered. Put an 1371 * error message to stderr buffer. 1372 */ 1373 snprintf(buf, sizeof buf, 1374 "write stdout: %.50s\r\n", strerror(errno)); 1375 buffer_append(&stderr_buffer, buf, strlen(buf)); 1376 quit_pending = 1; 1377 return; 1378 } 1379 } 1380 /* Consume printed data from the buffer. */ 1381 buffer_consume(&stdout_buffer, len); 1382 } 1383 /* Write buffered output to stderr. */ 1384 if (FD_ISSET(fileno(stderr), writeset)) { 1385 /* Write as much data as possible. */ 1386 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1387 buffer_len(&stderr_buffer)); 1388 if (len <= 0) { 1389 if (errno == EINTR || errno == EAGAIN || 1390 errno == EWOULDBLOCK) 1391 len = 0; 1392 else { 1393 /* 1394 * EOF or error, but can't even print 1395 * error message. 1396 */ 1397 quit_pending = 1; 1398 return; 1399 } 1400 } 1401 /* Consume printed characters from the buffer. */ 1402 buffer_consume(&stderr_buffer, len); 1403 } 1404 } 1405 1406 /* 1407 * Get packets from the connection input buffer, and process them as long as 1408 * there are packets available. 1409 * 1410 * Any unknown packets received during the actual 1411 * session cause the session to terminate. This is 1412 * intended to make debugging easier since no 1413 * confirmations are sent. Any compatible protocol 1414 * extensions must be negotiated during the 1415 * preparatory phase. 1416 */ 1417 1418 static void 1419 client_process_buffered_input_packets(void) 1420 { 1421 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1422 compat20 ? xxx_kex : NULL); 1423 } 1424 1425 /* scan buf[] for '~' before sending data to the peer */ 1426 1427 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1428 void * 1429 client_new_escape_filter_ctx(int escape_char) 1430 { 1431 struct escape_filter_ctx *ret; 1432 1433 ret = xmalloc(sizeof(*ret)); 1434 ret->escape_pending = 0; 1435 ret->escape_char = escape_char; 1436 return (void *)ret; 1437 } 1438 1439 /* Free the escape filter context on channel free */ 1440 void 1441 client_filter_cleanup(int cid, void *ctx) 1442 { 1443 xfree(ctx); 1444 } 1445 1446 int 1447 client_simple_escape_filter(Channel *c, char *buf, int len) 1448 { 1449 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1450 return 0; 1451 1452 return process_escapes(c, &c->input, &c->output, &c->extended, 1453 buf, len); 1454 } 1455 1456 static void 1457 client_channel_closed(int id, void *arg) 1458 { 1459 channel_cancel_cleanup(id); 1460 session_closed = 1; 1461 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1462 } 1463 1464 /* 1465 * Implements the interactive session with the server. This is called after 1466 * the user has been authenticated, and a command has been started on the 1467 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1468 * used as an escape character for terminating or suspending the session. 1469 */ 1470 1471 int 1472 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1473 { 1474 fd_set *readset = NULL, *writeset = NULL; 1475 double start_time, total_time; 1476 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1477 u_int64_t ibytes, obytes; 1478 u_int nalloc = 0; 1479 char buf[100]; 1480 1481 debug("Entering interactive session."); 1482 1483 start_time = get_current_time(); 1484 1485 /* Initialize variables. */ 1486 escape_pending1 = 0; 1487 last_was_cr = 1; 1488 exit_status = -1; 1489 stdin_eof = 0; 1490 buffer_high = 64 * 1024; 1491 connection_in = packet_get_connection_in(); 1492 connection_out = packet_get_connection_out(); 1493 max_fd = MAX(connection_in, connection_out); 1494 1495 if (!compat20) { 1496 /* enable nonblocking unless tty */ 1497 if (!isatty(fileno(stdin))) 1498 set_nonblock(fileno(stdin)); 1499 if (!isatty(fileno(stdout))) 1500 set_nonblock(fileno(stdout)); 1501 if (!isatty(fileno(stderr))) 1502 set_nonblock(fileno(stderr)); 1503 max_fd = MAX(max_fd, fileno(stdin)); 1504 max_fd = MAX(max_fd, fileno(stdout)); 1505 max_fd = MAX(max_fd, fileno(stderr)); 1506 } 1507 quit_pending = 0; 1508 escape_char1 = escape_char_arg; 1509 1510 /* Initialize buffers. */ 1511 buffer_init(&stdin_buffer); 1512 buffer_init(&stdout_buffer); 1513 buffer_init(&stderr_buffer); 1514 1515 client_init_dispatch(); 1516 1517 /* 1518 * Set signal handlers, (e.g. to restore non-blocking mode) 1519 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1520 */ 1521 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1522 signal(SIGHUP, signal_handler); 1523 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1524 signal(SIGINT, signal_handler); 1525 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1526 signal(SIGQUIT, signal_handler); 1527 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1528 signal(SIGTERM, signal_handler); 1529 signal(SIGWINCH, window_change_handler); 1530 1531 if (have_pty) 1532 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1533 1534 if (compat20) { 1535 session_ident = ssh2_chan_id; 1536 if (session_ident != -1) { 1537 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1538 channel_register_filter(session_ident, 1539 client_simple_escape_filter, NULL, 1540 client_filter_cleanup, 1541 client_new_escape_filter_ctx( 1542 escape_char_arg)); 1543 } 1544 channel_register_cleanup(session_ident, 1545 client_channel_closed, 0); 1546 } 1547 } else { 1548 /* Check if we should immediately send eof on stdin. */ 1549 client_check_initial_eof_on_stdin(); 1550 } 1551 1552 /* Main loop of the client for the interactive session mode. */ 1553 while (!quit_pending) { 1554 1555 /* Process buffered packets sent by the server. */ 1556 client_process_buffered_input_packets(); 1557 1558 if (compat20 && session_closed && !channel_still_open()) 1559 break; 1560 1561 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1562 1563 if (rekeying) { 1564 debug("rekeying in progress"); 1565 } else { 1566 /* 1567 * Make packets of buffered stdin data, and buffer 1568 * them for sending to the server. 1569 */ 1570 if (!compat20) 1571 client_make_packets_from_stdin_data(); 1572 1573 /* 1574 * Make packets from buffered channel data, and 1575 * enqueue them for sending to the server. 1576 */ 1577 if (packet_not_very_much_data_to_write()) 1578 channel_output_poll(); 1579 1580 /* 1581 * Check if the window size has changed, and buffer a 1582 * message about it to the server if so. 1583 */ 1584 client_check_window_change(); 1585 1586 if (quit_pending) 1587 break; 1588 } 1589 /* 1590 * Wait until we have something to do (something becomes 1591 * available on one of the descriptors). 1592 */ 1593 max_fd2 = max_fd; 1594 client_wait_until_can_do_something(&readset, &writeset, 1595 &max_fd2, &nalloc, rekeying); 1596 1597 if (quit_pending) 1598 break; 1599 1600 /* Do channel operations unless rekeying in progress. */ 1601 if (!rekeying) { 1602 channel_after_select(readset, writeset); 1603 if (need_rekeying || packet_need_rekeying()) { 1604 debug("need rekeying"); 1605 xxx_kex->done = 0; 1606 kex_send_kexinit(xxx_kex); 1607 need_rekeying = 0; 1608 } 1609 } 1610 1611 /* Buffer input from the connection. */ 1612 client_process_net_input(readset); 1613 1614 if (quit_pending) 1615 break; 1616 1617 if (!compat20) { 1618 /* Buffer data from stdin */ 1619 client_process_input(readset); 1620 /* 1621 * Process output to stdout and stderr. Output to 1622 * the connection is processed elsewhere (above). 1623 */ 1624 client_process_output(writeset); 1625 } 1626 1627 if (session_resumed) { 1628 connection_in = packet_get_connection_in(); 1629 connection_out = packet_get_connection_out(); 1630 max_fd = MAX(max_fd, connection_out); 1631 max_fd = MAX(max_fd, connection_in); 1632 session_resumed = 0; 1633 } 1634 1635 /* 1636 * Send as much buffered packet data as possible to the 1637 * sender. 1638 */ 1639 if (FD_ISSET(connection_out, writeset)) 1640 packet_write_poll(); 1641 1642 /* 1643 * If we are a backgrounded control master, and the 1644 * timeout has expired without any active client 1645 * connections, then quit. 1646 */ 1647 if (control_persist_exit_time > 0) { 1648 if (time(NULL) >= control_persist_exit_time) { 1649 debug("ControlPersist timeout expired"); 1650 break; 1651 } 1652 } 1653 } 1654 if (readset) 1655 xfree(readset); 1656 if (writeset) 1657 xfree(writeset); 1658 1659 /* Terminate the session. */ 1660 1661 /* Stop watching for window change. */ 1662 signal(SIGWINCH, SIG_DFL); 1663 1664 if (compat20) { 1665 packet_start(SSH2_MSG_DISCONNECT); 1666 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1667 packet_put_cstring("disconnected by user"); 1668 packet_put_cstring(""); /* language tag */ 1669 packet_send(); 1670 packet_write_wait(); 1671 } 1672 1673 channel_free_all(); 1674 1675 if (have_pty) 1676 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1677 1678 /* restore blocking io */ 1679 if (!isatty(fileno(stdin))) 1680 unset_nonblock(fileno(stdin)); 1681 if (!isatty(fileno(stdout))) 1682 unset_nonblock(fileno(stdout)); 1683 if (!isatty(fileno(stderr))) 1684 unset_nonblock(fileno(stderr)); 1685 1686 /* 1687 * If there was no shell or command requested, there will be no remote 1688 * exit status to be returned. In that case, clear error code if the 1689 * connection was deliberately terminated at this end. 1690 */ 1691 if (no_shell_flag && received_signal == SIGTERM) { 1692 received_signal = 0; 1693 exit_status = 0; 1694 } 1695 1696 if (received_signal) 1697 fatal("Killed by signal %d.", (int) received_signal); 1698 1699 /* 1700 * In interactive mode (with pseudo tty) display a message indicating 1701 * that the connection has been closed. 1702 */ 1703 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1704 snprintf(buf, sizeof buf, 1705 "Connection to %.64s closed.\r\n", host); 1706 buffer_append(&stderr_buffer, buf, strlen(buf)); 1707 } 1708 1709 /* Output any buffered data for stdout. */ 1710 if (buffer_len(&stdout_buffer) > 0) { 1711 len = atomicio(vwrite, fileno(stdout), 1712 buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer)); 1713 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer)) 1714 error("Write failed flushing stdout buffer."); 1715 else 1716 buffer_consume(&stdout_buffer, len); 1717 } 1718 1719 /* Output any buffered data for stderr. */ 1720 if (buffer_len(&stderr_buffer) > 0) { 1721 len = atomicio(vwrite, fileno(stderr), 1722 buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer)); 1723 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer)) 1724 error("Write failed flushing stderr buffer."); 1725 else 1726 buffer_consume(&stderr_buffer, len); 1727 } 1728 1729 /* Clear and free any buffers. */ 1730 memset(buf, 0, sizeof(buf)); 1731 buffer_free(&stdin_buffer); 1732 buffer_free(&stdout_buffer); 1733 buffer_free(&stderr_buffer); 1734 1735 /* Report bytes transferred, and transfer rates. */ 1736 total_time = get_current_time() - start_time; 1737 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1738 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1739 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1740 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1741 if (total_time > 0) 1742 verbose("Bytes per second: sent %.1f, received %.1f", 1743 obytes / total_time, ibytes / total_time); 1744 /* Return the exit status of the program. */ 1745 debug("Exit status %d", exit_status); 1746 return exit_status; 1747 } 1748 1749 /*********/ 1750 1751 static void 1752 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1753 { 1754 u_int data_len; 1755 char *data = packet_get_string(&data_len); 1756 packet_check_eom(); 1757 buffer_append(&stdout_buffer, data, data_len); 1758 memset(data, 0, data_len); 1759 xfree(data); 1760 } 1761 static void 1762 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1763 { 1764 u_int data_len; 1765 char *data = packet_get_string(&data_len); 1766 packet_check_eom(); 1767 buffer_append(&stderr_buffer, data, data_len); 1768 memset(data, 0, data_len); 1769 xfree(data); 1770 } 1771 static void 1772 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1773 { 1774 exit_status = packet_get_int(); 1775 packet_check_eom(); 1776 /* Acknowledge the exit. */ 1777 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1778 packet_send(); 1779 /* 1780 * Must wait for packet to be sent since we are 1781 * exiting the loop. 1782 */ 1783 packet_write_wait(); 1784 /* Flag that we want to exit. */ 1785 quit_pending = 1; 1786 } 1787 static void 1788 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1789 { 1790 Channel *c = NULL; 1791 int remote_id, sock; 1792 1793 /* Read the remote channel number from the message. */ 1794 remote_id = packet_get_int(); 1795 packet_check_eom(); 1796 1797 /* 1798 * Get a connection to the local authentication agent (this may again 1799 * get forwarded). 1800 */ 1801 sock = ssh_get_authentication_socket(); 1802 1803 /* 1804 * If we could not connect the agent, send an error message back to 1805 * the server. This should never happen unless the agent dies, 1806 * because authentication forwarding is only enabled if we have an 1807 * agent. 1808 */ 1809 if (sock >= 0) { 1810 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1811 -1, 0, 0, 0, "authentication agent connection", 1); 1812 c->remote_id = remote_id; 1813 c->force_drain = 1; 1814 } 1815 if (c == NULL) { 1816 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1817 packet_put_int(remote_id); 1818 } else { 1819 /* Send a confirmation to the remote host. */ 1820 debug("Forwarding authentication connection."); 1821 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1822 packet_put_int(remote_id); 1823 packet_put_int(c->self); 1824 } 1825 packet_send(); 1826 } 1827 1828 static Channel * 1829 client_request_forwarded_tcpip(const char *request_type, int rchan) 1830 { 1831 Channel *c = NULL; 1832 char *listen_address, *originator_address; 1833 u_short listen_port, originator_port; 1834 1835 /* Get rest of the packet */ 1836 listen_address = packet_get_string(NULL); 1837 listen_port = packet_get_int(); 1838 originator_address = packet_get_string(NULL); 1839 originator_port = packet_get_int(); 1840 packet_check_eom(); 1841 1842 debug("client_request_forwarded_tcpip: listen %s port %d, " 1843 "originator %s port %d", listen_address, listen_port, 1844 originator_address, originator_port); 1845 1846 c = channel_connect_by_listen_address(listen_port, 1847 "forwarded-tcpip", originator_address); 1848 1849 xfree(originator_address); 1850 xfree(listen_address); 1851 return c; 1852 } 1853 1854 static Channel * 1855 client_request_x11(const char *request_type, int rchan) 1856 { 1857 Channel *c = NULL; 1858 char *originator; 1859 u_short originator_port; 1860 int sock; 1861 1862 if (!options.forward_x11) { 1863 error("Warning: ssh server tried X11 forwarding."); 1864 error("Warning: this is probably a break-in attempt by a " 1865 "malicious server."); 1866 return NULL; 1867 } 1868 if (x11_refuse_time != 0 && time(NULL) >= x11_refuse_time) { 1869 verbose("Rejected X11 connection after ForwardX11Timeout " 1870 "expired"); 1871 return NULL; 1872 } 1873 originator = packet_get_string(NULL); 1874 if (datafellows & SSH_BUG_X11FWD) { 1875 debug2("buggy server: x11 request w/o originator_port"); 1876 originator_port = 0; 1877 } else { 1878 originator_port = packet_get_int(); 1879 } 1880 packet_check_eom(); 1881 /* XXX check permission */ 1882 debug("client_request_x11: request from %s %d", originator, 1883 originator_port); 1884 xfree(originator); 1885 sock = x11_connect_display(); 1886 if (sock < 0) 1887 return NULL; 1888 if (options.hpn_disabled) 1889 c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1890 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 1891 0, "x11", 1); 1892 else 1893 c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1894 options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 1895 0, "x11", 1); 1896 c->force_drain = 1; 1897 return c; 1898 } 1899 1900 static Channel * 1901 client_request_agent(const char *request_type, int rchan) 1902 { 1903 Channel *c = NULL; 1904 int sock; 1905 1906 if (!options.forward_agent) { 1907 error("Warning: ssh server tried agent forwarding."); 1908 error("Warning: this is probably a break-in attempt by a " 1909 "malicious server."); 1910 return NULL; 1911 } 1912 sock = ssh_get_authentication_socket(); 1913 if (sock < 0) 1914 return NULL; 1915 if (options.hpn_disabled) 1916 c = channel_new("authentication agent connection", 1917 SSH_CHANNEL_OPEN, sock, sock, -1, 1918 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, 1919 "authentication agent connection", 1); 1920 else 1921 c = channel_new("authentication agent connection", 1922 SSH_CHANNEL_OPEN, sock, sock, -1, 1923 options.hpn_buffer_size, options.hpn_buffer_size, 0, 1924 "authentication agent connection", 1); 1925 c->force_drain = 1; 1926 return c; 1927 } 1928 1929 int 1930 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1931 { 1932 Channel *c; 1933 int fd; 1934 1935 if (tun_mode == SSH_TUNMODE_NO) 1936 return 0; 1937 1938 if (!compat20) { 1939 error("Tunnel forwarding is not supported for protocol 1"); 1940 return -1; 1941 } 1942 1943 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1944 1945 /* Open local tunnel device */ 1946 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1947 error("Tunnel device open failed."); 1948 return -1; 1949 } 1950 1951 if (options.hpn_disabled) 1952 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1953 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 1954 0, "tun", 1); 1955 else 1956 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1957 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 1958 0, "tun", 1); 1959 c->datagram = 1; 1960 1961 #if defined(SSH_TUN_FILTER) 1962 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1963 channel_register_filter(c->self, sys_tun_infilter, 1964 sys_tun_outfilter, NULL, NULL); 1965 #endif 1966 1967 packet_start(SSH2_MSG_CHANNEL_OPEN); 1968 packet_put_cstring("tun@openssh.com"); 1969 packet_put_int(c->self); 1970 packet_put_int(c->local_window_max); 1971 packet_put_int(c->local_maxpacket); 1972 packet_put_int(tun_mode); 1973 packet_put_int(remote_tun); 1974 packet_send(); 1975 1976 return 0; 1977 } 1978 1979 /* XXXX move to generic input handler */ 1980 static void 1981 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1982 { 1983 Channel *c = NULL; 1984 char *ctype; 1985 int rchan; 1986 u_int rmaxpack, rwindow, len; 1987 1988 ctype = packet_get_string(&len); 1989 rchan = packet_get_int(); 1990 rwindow = packet_get_int(); 1991 rmaxpack = packet_get_int(); 1992 1993 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1994 ctype, rchan, rwindow, rmaxpack); 1995 1996 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1997 c = client_request_forwarded_tcpip(ctype, rchan); 1998 } else if (strcmp(ctype, "x11") == 0) { 1999 c = client_request_x11(ctype, rchan); 2000 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 2001 c = client_request_agent(ctype, rchan); 2002 } 2003 /* XXX duplicate : */ 2004 if (c != NULL) { 2005 debug("confirm %s", ctype); 2006 c->remote_id = rchan; 2007 c->remote_window = rwindow; 2008 c->remote_maxpacket = rmaxpack; 2009 if (c->type != SSH_CHANNEL_CONNECTING) { 2010 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 2011 packet_put_int(c->remote_id); 2012 packet_put_int(c->self); 2013 packet_put_int(c->local_window); 2014 packet_put_int(c->local_maxpacket); 2015 packet_send(); 2016 } 2017 } else { 2018 debug("failure %s", ctype); 2019 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 2020 packet_put_int(rchan); 2021 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 2022 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 2023 packet_put_cstring("open failed"); 2024 packet_put_cstring(""); 2025 } 2026 packet_send(); 2027 } 2028 xfree(ctype); 2029 } 2030 static void 2031 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 2032 { 2033 Channel *c = NULL; 2034 int exitval, id, reply, success = 0; 2035 char *rtype; 2036 2037 id = packet_get_int(); 2038 rtype = packet_get_string(NULL); 2039 reply = packet_get_char(); 2040 2041 debug("client_input_channel_req: channel %d rtype %s reply %d", 2042 id, rtype, reply); 2043 2044 if (id == -1) { 2045 error("client_input_channel_req: request for channel -1"); 2046 } else if ((c = channel_lookup(id)) == NULL) { 2047 error("client_input_channel_req: channel %d: " 2048 "unknown channel", id); 2049 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 2050 packet_check_eom(); 2051 chan_rcvd_eow(c); 2052 } else if (strcmp(rtype, "exit-status") == 0) { 2053 exitval = packet_get_int(); 2054 if (c->ctl_chan != -1) { 2055 mux_exit_message(c, exitval); 2056 success = 1; 2057 } else if (id == session_ident) { 2058 /* Record exit value of local session */ 2059 success = 1; 2060 exit_status = exitval; 2061 } else { 2062 /* Probably for a mux channel that has already closed */ 2063 debug("%s: no sink for exit-status on channel %d", 2064 __func__, id); 2065 } 2066 packet_check_eom(); 2067 } 2068 if (reply && c != NULL) { 2069 packet_start(success ? 2070 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 2071 packet_put_int(c->remote_id); 2072 packet_send(); 2073 } 2074 xfree(rtype); 2075 } 2076 static void 2077 client_input_global_request(int type, u_int32_t seq, void *ctxt) 2078 { 2079 char *rtype; 2080 int want_reply; 2081 int success = 0; 2082 2083 rtype = packet_get_string(NULL); 2084 want_reply = packet_get_char(); 2085 debug("client_input_global_request: rtype %s want_reply %d", 2086 rtype, want_reply); 2087 if (want_reply) { 2088 packet_start(success ? 2089 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 2090 packet_send(); 2091 packet_write_wait(); 2092 } 2093 xfree(rtype); 2094 } 2095 2096 void 2097 client_session2_setup(int id, int want_tty, int want_subsystem, 2098 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 2099 { 2100 int len; 2101 Channel *c = NULL; 2102 2103 debug2("%s: id %d", __func__, id); 2104 2105 if ((c = channel_lookup(id)) == NULL) 2106 fatal("client_session2_setup: channel %d: unknown channel", id); 2107 2108 packet_set_interactive(want_tty, 2109 options.ip_qos_interactive, options.ip_qos_bulk); 2110 2111 if (want_tty) { 2112 struct winsize ws; 2113 2114 /* Store window size in the packet. */ 2115 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 2116 memset(&ws, 0, sizeof(ws)); 2117 2118 channel_request_start(id, "pty-req", 1); 2119 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); 2120 packet_put_cstring(term != NULL ? term : ""); 2121 packet_put_int((u_int)ws.ws_col); 2122 packet_put_int((u_int)ws.ws_row); 2123 packet_put_int((u_int)ws.ws_xpixel); 2124 packet_put_int((u_int)ws.ws_ypixel); 2125 if (tiop == NULL) 2126 tiop = get_saved_tio(); 2127 tty_make_modes(-1, tiop); 2128 packet_send(); 2129 /* XXX wait for reply */ 2130 c->client_tty = 1; 2131 } 2132 2133 /* Transfer any environment variables from client to server */ 2134 if (options.num_send_env != 0 && env != NULL) { 2135 int i, j, matched; 2136 char *name, *val; 2137 2138 debug("Sending environment."); 2139 for (i = 0; env[i] != NULL; i++) { 2140 /* Split */ 2141 name = xstrdup(env[i]); 2142 if ((val = strchr(name, '=')) == NULL) { 2143 xfree(name); 2144 continue; 2145 } 2146 *val++ = '\0'; 2147 2148 matched = 0; 2149 for (j = 0; j < options.num_send_env; j++) { 2150 if (match_pattern(name, options.send_env[j])) { 2151 matched = 1; 2152 break; 2153 } 2154 } 2155 if (!matched) { 2156 debug3("Ignored env %s", name); 2157 xfree(name); 2158 continue; 2159 } 2160 2161 debug("Sending env %s = %s", name, val); 2162 channel_request_start(id, "env", 0); 2163 packet_put_cstring(name); 2164 packet_put_cstring(val); 2165 packet_send(); 2166 xfree(name); 2167 } 2168 } 2169 2170 len = buffer_len(cmd); 2171 if (len > 0) { 2172 if (len > 900) 2173 len = 900; 2174 if (want_subsystem) { 2175 debug("Sending subsystem: %.*s", 2176 len, (u_char*)buffer_ptr(cmd)); 2177 channel_request_start(id, "subsystem", 1); 2178 client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); 2179 } else { 2180 debug("Sending command: %.*s", 2181 len, (u_char*)buffer_ptr(cmd)); 2182 channel_request_start(id, "exec", 1); 2183 client_expect_confirm(id, "exec", CONFIRM_CLOSE); 2184 } 2185 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 2186 packet_send(); 2187 } else { 2188 channel_request_start(id, "shell", 1); 2189 client_expect_confirm(id, "shell", CONFIRM_CLOSE); 2190 packet_send(); 2191 } 2192 } 2193 2194 static void 2195 client_init_dispatch_20(void) 2196 { 2197 dispatch_init(&dispatch_protocol_error); 2198 2199 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2200 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2201 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2202 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2203 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2204 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2205 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2206 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2207 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2208 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2209 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2210 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2211 2212 /* rekeying */ 2213 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2214 2215 /* global request reply messages */ 2216 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2217 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2218 } 2219 2220 static void 2221 client_init_dispatch_13(void) 2222 { 2223 dispatch_init(NULL); 2224 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2225 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2226 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2227 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2228 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2229 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2230 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2231 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2232 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2233 2234 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2235 &client_input_agent_open : &deny_input_open); 2236 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2237 &x11_input_open : &deny_input_open); 2238 } 2239 2240 static void 2241 client_init_dispatch_15(void) 2242 { 2243 client_init_dispatch_13(); 2244 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2245 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2246 } 2247 2248 static void 2249 client_init_dispatch(void) 2250 { 2251 if (compat20) 2252 client_init_dispatch_20(); 2253 else if (compat13) 2254 client_init_dispatch_13(); 2255 else 2256 client_init_dispatch_15(); 2257 } 2258 2259 void 2260 client_stop_mux(void) 2261 { 2262 if (options.control_path != NULL && muxserver_sock != -1) 2263 unlink(options.control_path); 2264 /* 2265 * If we are in persist mode, or don't have a shell, signal that we 2266 * should close when all active channels are closed. 2267 */ 2268 if (options.control_persist || no_shell_flag) { 2269 session_closed = 1; 2270 setproctitle("[stopped mux]"); 2271 } 2272 } 2273 2274 /* client specific fatal cleanup */ 2275 void 2276 cleanup_exit(int i) 2277 { 2278 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2279 leave_non_blocking(); 2280 if (options.control_path != NULL && muxserver_sock != -1) 2281 unlink(options.control_path); 2282 ssh_kill_proxy_command(); 2283 _exit(i); 2284 } 2285