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