1 /* $OpenBSD: clientloop.c,v 1.255 2013/11/08 00:39:15 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 = monotime() + 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 = monotime() + 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 free(xauthdir); 398 free(xauthfile); 399 400 /* 401 * If we didn't get authentication data, just make up some 402 * data. The forwarding code will check the validity of the 403 * response anyway, and substitute this data. The X11 404 * server, however, will ignore this fake data and use 405 * whatever authentication mechanisms it was using otherwise 406 * for the local connection. 407 */ 408 if (!got_data) { 409 u_int32_t rnd = 0; 410 411 logit("Warning: No xauth data; " 412 "using fake authentication data for X11 forwarding."); 413 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 414 for (i = 0; i < 16; i++) { 415 if (i % 4 == 0) 416 rnd = arc4random(); 417 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 418 rnd & 0xff); 419 rnd >>= 8; 420 } 421 } 422 } 423 424 /* 425 * This is called when the interactive is entered. This checks if there is 426 * an EOF coming on stdin. We must check this explicitly, as select() does 427 * not appear to wake up when redirecting from /dev/null. 428 */ 429 430 static void 431 client_check_initial_eof_on_stdin(void) 432 { 433 int len; 434 char buf[1]; 435 436 /* 437 * If standard input is to be "redirected from /dev/null", we simply 438 * mark that we have seen an EOF and send an EOF message to the 439 * server. Otherwise, we try to read a single character; it appears 440 * that for some files, such /dev/null, select() never wakes up for 441 * read for this descriptor, which means that we never get EOF. This 442 * way we will get the EOF if stdin comes from /dev/null or similar. 443 */ 444 if (stdin_null_flag) { 445 /* Fake EOF on stdin. */ 446 debug("Sending eof."); 447 stdin_eof = 1; 448 packet_start(SSH_CMSG_EOF); 449 packet_send(); 450 } else { 451 enter_non_blocking(); 452 453 /* Check for immediate EOF on stdin. */ 454 len = read(fileno(stdin), buf, 1); 455 if (len == 0) { 456 /* 457 * EOF. Record that we have seen it and send 458 * EOF to server. 459 */ 460 debug("Sending eof."); 461 stdin_eof = 1; 462 packet_start(SSH_CMSG_EOF); 463 packet_send(); 464 } else if (len > 0) { 465 /* 466 * Got data. We must store the data in the buffer, 467 * and also process it as an escape character if 468 * appropriate. 469 */ 470 if ((u_char) buf[0] == escape_char1) 471 escape_pending1 = 1; 472 else 473 buffer_append(&stdin_buffer, buf, 1); 474 } 475 leave_non_blocking(); 476 } 477 } 478 479 480 /* 481 * Make packets from buffered stdin data, and buffer them for sending to the 482 * connection. 483 */ 484 485 static void 486 client_make_packets_from_stdin_data(void) 487 { 488 u_int len; 489 490 /* Send buffered stdin data to the server. */ 491 while (buffer_len(&stdin_buffer) > 0 && 492 packet_not_very_much_data_to_write()) { 493 len = buffer_len(&stdin_buffer); 494 /* Keep the packets at reasonable size. */ 495 if (len > packet_get_maxsize()) 496 len = packet_get_maxsize(); 497 packet_start(SSH_CMSG_STDIN_DATA); 498 packet_put_string(buffer_ptr(&stdin_buffer), len); 499 packet_send(); 500 buffer_consume(&stdin_buffer, len); 501 /* If we have a pending EOF, send it now. */ 502 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 503 packet_start(SSH_CMSG_EOF); 504 packet_send(); 505 } 506 } 507 } 508 509 /* 510 * Checks if the client window has changed, and sends a packet about it to 511 * the server if so. The actual change is detected elsewhere (by a software 512 * interrupt on Unix); this just checks the flag and sends a message if 513 * appropriate. 514 */ 515 516 static void 517 client_check_window_change(void) 518 { 519 struct winsize ws; 520 521 if (! received_window_change_signal) 522 return; 523 /** XXX race */ 524 received_window_change_signal = 0; 525 526 debug2("client_check_window_change: changed"); 527 528 if (compat20) { 529 channel_send_window_changes(); 530 } else { 531 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 532 return; 533 packet_start(SSH_CMSG_WINDOW_SIZE); 534 packet_put_int((u_int)ws.ws_row); 535 packet_put_int((u_int)ws.ws_col); 536 packet_put_int((u_int)ws.ws_xpixel); 537 packet_put_int((u_int)ws.ws_ypixel); 538 packet_send(); 539 } 540 } 541 542 static void 543 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 544 { 545 struct global_confirm *gc; 546 547 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 548 return; 549 if (gc->cb != NULL) 550 gc->cb(type, seq, gc->ctx); 551 if (--gc->ref_count <= 0) { 552 TAILQ_REMOVE(&global_confirms, gc, entry); 553 bzero(gc, sizeof(*gc)); 554 free(gc); 555 } 556 557 packet_set_alive_timeouts(0); 558 } 559 560 static void 561 server_alive_check(void) 562 { 563 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 564 logit("Timeout, server %s not responding.", host); 565 cleanup_exit(255); 566 } 567 packet_start(SSH2_MSG_GLOBAL_REQUEST); 568 packet_put_cstring("keepalive@openssh.com"); 569 packet_put_char(1); /* boolean: want reply */ 570 packet_send(); 571 /* Insert an empty placeholder to maintain ordering */ 572 client_register_global_confirm(NULL, NULL); 573 } 574 575 /* 576 * Waits until the client can do something (some data becomes available on 577 * one of the file descriptors). 578 */ 579 static void 580 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 581 int *maxfdp, u_int *nallocp, int rekeying) 582 { 583 struct timeval tv, *tvp; 584 int timeout_secs; 585 time_t minwait_secs = 0, server_alive_time = 0, now = monotime(); 586 int ret; 587 588 /* Add any selections by the channel mechanism. */ 589 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 590 &minwait_secs, rekeying); 591 592 if (!compat20) { 593 /* Read from the connection, unless our buffers are full. */ 594 if (buffer_len(&stdout_buffer) < buffer_high && 595 buffer_len(&stderr_buffer) < buffer_high && 596 channel_not_very_much_buffered_data()) 597 FD_SET(connection_in, *readsetp); 598 /* 599 * Read from stdin, unless we have seen EOF or have very much 600 * buffered data to send to the server. 601 */ 602 if (!stdin_eof && packet_not_very_much_data_to_write()) 603 FD_SET(fileno(stdin), *readsetp); 604 605 /* Select stdout/stderr if have data in buffer. */ 606 if (buffer_len(&stdout_buffer) > 0) 607 FD_SET(fileno(stdout), *writesetp); 608 if (buffer_len(&stderr_buffer) > 0) 609 FD_SET(fileno(stderr), *writesetp); 610 } else { 611 /* channel_prepare_select could have closed the last channel */ 612 if (session_closed && !channel_still_open() && 613 !packet_have_data_to_write()) { 614 /* clear mask since we did not call select() */ 615 memset(*readsetp, 0, *nallocp); 616 memset(*writesetp, 0, *nallocp); 617 return; 618 } else { 619 FD_SET(connection_in, *readsetp); 620 } 621 } 622 623 /* Select server connection if have data to write to the server. */ 624 if (packet_have_data_to_write()) 625 FD_SET(connection_out, *writesetp); 626 627 /* 628 * Wait for something to happen. This will suspend the process until 629 * some selected descriptor can be read, written, or has some other 630 * event pending, or a timeout expires. 631 */ 632 633 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 634 if (options.server_alive_interval > 0 && compat20) { 635 timeout_secs = options.server_alive_interval; 636 server_alive_time = now + options.server_alive_interval; 637 } 638 if (options.rekey_interval > 0 && compat20 && !rekeying) 639 timeout_secs = MIN(timeout_secs, packet_get_rekey_timeout()); 640 set_control_persist_exit_time(); 641 if (control_persist_exit_time > 0) { 642 timeout_secs = MIN(timeout_secs, 643 control_persist_exit_time - now); 644 if (timeout_secs < 0) 645 timeout_secs = 0; 646 } 647 if (minwait_secs != 0) 648 timeout_secs = MIN(timeout_secs, (int)minwait_secs); 649 if (timeout_secs == INT_MAX) 650 tvp = NULL; 651 else { 652 tv.tv_sec = timeout_secs; 653 tv.tv_usec = 0; 654 tvp = &tv; 655 } 656 657 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 658 if (ret < 0) { 659 char buf[100]; 660 661 /* 662 * We have to clear the select masks, because we return. 663 * We have to return, because the mainloop checks for the flags 664 * set by the signal handlers. 665 */ 666 memset(*readsetp, 0, *nallocp); 667 memset(*writesetp, 0, *nallocp); 668 669 if (errno == EINTR) 670 return; 671 /* Note: we might still have data in the buffers. */ 672 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 673 buffer_append(&stderr_buffer, buf, strlen(buf)); 674 quit_pending = 1; 675 } else if (ret == 0) { 676 /* 677 * Timeout. Could have been either keepalive or rekeying. 678 * Keepalive we check here, rekeying is checked in clientloop. 679 */ 680 if (server_alive_time != 0 && server_alive_time <= monotime()) 681 server_alive_check(); 682 } 683 684 } 685 686 static void 687 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 688 { 689 /* Flush stdout and stderr buffers. */ 690 if (buffer_len(bout) > 0) 691 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 692 buffer_len(bout)); 693 if (buffer_len(berr) > 0) 694 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 695 buffer_len(berr)); 696 697 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 698 699 /* 700 * Free (and clear) the buffer to reduce the amount of data that gets 701 * written to swap. 702 */ 703 buffer_free(bin); 704 buffer_free(bout); 705 buffer_free(berr); 706 707 /* Send the suspend signal to the program itself. */ 708 kill(getpid(), SIGTSTP); 709 710 /* Reset window sizes in case they have changed */ 711 received_window_change_signal = 1; 712 713 /* OK, we have been continued by the user. Reinitialize buffers. */ 714 buffer_init(bin); 715 buffer_init(bout); 716 buffer_init(berr); 717 718 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 719 } 720 721 static void 722 client_process_net_input(fd_set *readset) 723 { 724 int len, cont = 0; 725 char buf[SSH_IOBUFSZ]; 726 727 /* 728 * Read input from the server, and add any such data to the buffer of 729 * the packet subsystem. 730 */ 731 if (FD_ISSET(connection_in, readset)) { 732 /* Read as much as possible. */ 733 len = roaming_read(connection_in, buf, sizeof(buf), &cont); 734 if (len == 0 && cont == 0) { 735 /* 736 * Received EOF. The remote host has closed the 737 * connection. 738 */ 739 snprintf(buf, sizeof buf, 740 "Connection to %.300s closed by remote host.\r\n", 741 host); 742 buffer_append(&stderr_buffer, buf, strlen(buf)); 743 quit_pending = 1; 744 return; 745 } 746 /* 747 * There is a kernel bug on Solaris that causes select to 748 * sometimes wake up even though there is no data available. 749 */ 750 if (len < 0 && 751 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 752 len = 0; 753 754 if (len < 0) { 755 /* 756 * An error has encountered. Perhaps there is a 757 * network problem. 758 */ 759 snprintf(buf, sizeof buf, 760 "Read from remote host %.300s: %.100s\r\n", 761 host, strerror(errno)); 762 buffer_append(&stderr_buffer, buf, strlen(buf)); 763 quit_pending = 1; 764 return; 765 } 766 packet_process_incoming(buf, len); 767 } 768 } 769 770 static void 771 client_status_confirm(int type, Channel *c, void *ctx) 772 { 773 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 774 char errmsg[256]; 775 int tochan; 776 777 /* 778 * If a TTY was explicitly requested, then a failure to allocate 779 * one is fatal. 780 */ 781 if (cr->action == CONFIRM_TTY && 782 (options.request_tty == REQUEST_TTY_FORCE || 783 options.request_tty == REQUEST_TTY_YES)) 784 cr->action = CONFIRM_CLOSE; 785 786 /* XXX supress on mux _client_ quietmode */ 787 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 788 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 789 790 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 791 debug2("%s request accepted on channel %d", 792 cr->request_type, c->self); 793 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 794 if (tochan) { 795 snprintf(errmsg, sizeof(errmsg), 796 "%s request failed\r\n", cr->request_type); 797 } else { 798 snprintf(errmsg, sizeof(errmsg), 799 "%s request failed on channel %d", 800 cr->request_type, c->self); 801 } 802 /* If error occurred on primary session channel, then exit */ 803 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 804 fatal("%s", errmsg); 805 /* 806 * If error occurred on mux client, append to 807 * their stderr. 808 */ 809 if (tochan) { 810 buffer_append(&c->extended, errmsg, 811 strlen(errmsg)); 812 } else 813 error("%s", errmsg); 814 if (cr->action == CONFIRM_TTY) { 815 /* 816 * If a TTY allocation error occurred, then arrange 817 * for the correct TTY to leave raw mode. 818 */ 819 if (c->self == session_ident) 820 leave_raw_mode(0); 821 else 822 mux_tty_alloc_failed(c); 823 } else if (cr->action == CONFIRM_CLOSE) { 824 chan_read_failed(c); 825 chan_write_failed(c); 826 } 827 } 828 free(cr); 829 } 830 831 static void 832 client_abandon_status_confirm(Channel *c, void *ctx) 833 { 834 free(ctx); 835 } 836 837 void 838 client_expect_confirm(int id, const char *request, 839 enum confirm_action action) 840 { 841 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 842 843 cr->request_type = request; 844 cr->action = action; 845 846 channel_register_status_confirm(id, client_status_confirm, 847 client_abandon_status_confirm, cr); 848 } 849 850 void 851 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 852 { 853 struct global_confirm *gc, *last_gc; 854 855 /* Coalesce identical callbacks */ 856 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 857 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 858 if (++last_gc->ref_count >= INT_MAX) 859 fatal("%s: last_gc->ref_count = %d", 860 __func__, last_gc->ref_count); 861 return; 862 } 863 864 gc = xcalloc(1, sizeof(*gc)); 865 gc->cb = cb; 866 gc->ctx = ctx; 867 gc->ref_count = 1; 868 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 869 } 870 871 static void 872 process_cmdline(void) 873 { 874 void (*handler)(int); 875 char *s, *cmd, *cancel_host; 876 int delete = 0, local = 0, remote = 0, dynamic = 0; 877 int cancel_port, ok; 878 Forward fwd; 879 880 bzero(&fwd, sizeof(fwd)); 881 fwd.listen_host = fwd.connect_host = NULL; 882 883 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 884 handler = signal(SIGINT, SIG_IGN); 885 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 886 if (s == NULL) 887 goto out; 888 while (isspace(*s)) 889 s++; 890 if (*s == '-') 891 s++; /* Skip cmdline '-', if any */ 892 if (*s == '\0') 893 goto out; 894 895 if (*s == 'h' || *s == 'H' || *s == '?') { 896 logit("Commands:"); 897 logit(" -L[bind_address:]port:host:hostport " 898 "Request local forward"); 899 logit(" -R[bind_address:]port:host:hostport " 900 "Request remote forward"); 901 logit(" -D[bind_address:]port " 902 "Request dynamic forward"); 903 logit(" -KL[bind_address:]port " 904 "Cancel local forward"); 905 logit(" -KR[bind_address:]port " 906 "Cancel remote forward"); 907 logit(" -KD[bind_address:]port " 908 "Cancel dynamic forward"); 909 if (!options.permit_local_command) 910 goto out; 911 logit(" !args " 912 "Execute local command"); 913 goto out; 914 } 915 916 if (*s == '!' && options.permit_local_command) { 917 s++; 918 ssh_local_cmd(s); 919 goto out; 920 } 921 922 if (*s == 'K') { 923 delete = 1; 924 s++; 925 } 926 if (*s == 'L') 927 local = 1; 928 else if (*s == 'R') 929 remote = 1; 930 else if (*s == 'D') 931 dynamic = 1; 932 else { 933 logit("Invalid command."); 934 goto out; 935 } 936 937 if (delete && !compat20) { 938 logit("Not supported for SSH protocol version 1."); 939 goto out; 940 } 941 942 while (isspace(*++s)) 943 ; 944 945 /* XXX update list of forwards in options */ 946 if (delete) { 947 cancel_port = 0; 948 cancel_host = hpdelim(&s); /* may be NULL */ 949 if (s != NULL) { 950 cancel_port = a2port(s); 951 cancel_host = cleanhostname(cancel_host); 952 } else { 953 cancel_port = a2port(cancel_host); 954 cancel_host = NULL; 955 } 956 if (cancel_port <= 0) { 957 logit("Bad forwarding close port"); 958 goto out; 959 } 960 if (remote) 961 ok = channel_request_rforward_cancel(cancel_host, 962 cancel_port) == 0; 963 else if (dynamic) 964 ok = channel_cancel_lport_listener(cancel_host, 965 cancel_port, 0, options.gateway_ports) > 0; 966 else 967 ok = channel_cancel_lport_listener(cancel_host, 968 cancel_port, CHANNEL_CANCEL_PORT_STATIC, 969 options.gateway_ports) > 0; 970 if (!ok) { 971 logit("Unkown port forwarding."); 972 goto out; 973 } 974 logit("Canceled forwarding."); 975 } else { 976 if (!parse_forward(&fwd, s, dynamic, remote)) { 977 logit("Bad forwarding specification."); 978 goto out; 979 } 980 if (local || dynamic) { 981 if (!channel_setup_local_fwd_listener(fwd.listen_host, 982 fwd.listen_port, fwd.connect_host, 983 fwd.connect_port, options.gateway_ports)) { 984 logit("Port forwarding failed."); 985 goto out; 986 } 987 } else { 988 if (channel_request_remote_forwarding(fwd.listen_host, 989 fwd.listen_port, fwd.connect_host, 990 fwd.connect_port) < 0) { 991 logit("Port forwarding failed."); 992 goto out; 993 } 994 } 995 logit("Forwarding port."); 996 } 997 998 out: 999 signal(SIGINT, handler); 1000 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1001 free(cmd); 1002 free(fwd.listen_host); 1003 free(fwd.connect_host); 1004 } 1005 1006 /* reasons to suppress output of an escape command in help output */ 1007 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 1008 #define SUPPRESS_PROTO1 1 /* don't show in protocol 1 sessions */ 1009 #define SUPPRESS_MUXCLIENT 2 /* don't show in mux client sessions */ 1010 #define SUPPRESS_MUXMASTER 4 /* don't show in mux master sessions */ 1011 #define SUPPRESS_SYSLOG 8 /* don't show when logging to syslog */ 1012 struct escape_help_text { 1013 const char *cmd; 1014 const char *text; 1015 unsigned int flags; 1016 }; 1017 static struct escape_help_text esc_txt[] = { 1018 {".", "terminate session", SUPPRESS_MUXMASTER}, 1019 {".", "terminate connection (and any multiplexed sessions)", 1020 SUPPRESS_MUXCLIENT}, 1021 {"B", "send a BREAK to the remote system", SUPPRESS_PROTO1}, 1022 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 1023 {"R", "request rekey", SUPPRESS_PROTO1}, 1024 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 1025 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 1026 {"#", "list forwarded connections", SUPPRESS_NEVER}, 1027 {"&", "background ssh (when waiting for connections to terminate)", 1028 SUPPRESS_MUXCLIENT}, 1029 {"?", "this message", SUPPRESS_NEVER}, 1030 }; 1031 1032 static void 1033 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client, 1034 int using_stderr) 1035 { 1036 unsigned int i, suppress_flags; 1037 char string[1024]; 1038 1039 snprintf(string, sizeof string, "%c?\r\n" 1040 "Supported escape sequences:\r\n", escape_char); 1041 buffer_append(b, string, strlen(string)); 1042 1043 suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) | 1044 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 1045 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 1046 (using_stderr ? 0 : SUPPRESS_SYSLOG); 1047 1048 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 1049 if (esc_txt[i].flags & suppress_flags) 1050 continue; 1051 snprintf(string, sizeof string, " %c%-3s - %s\r\n", 1052 escape_char, esc_txt[i].cmd, esc_txt[i].text); 1053 buffer_append(b, string, strlen(string)); 1054 } 1055 1056 snprintf(string, sizeof string, 1057 " %c%c - send the escape character by typing it twice\r\n" 1058 "(Note that escapes are only recognized immediately after " 1059 "newline.)\r\n", escape_char, escape_char); 1060 buffer_append(b, string, strlen(string)); 1061 } 1062 1063 /* 1064 * Process the characters one by one, call with c==NULL for proto1 case. 1065 */ 1066 static int 1067 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 1068 char *buf, int len) 1069 { 1070 char string[1024]; 1071 pid_t pid; 1072 int bytes = 0; 1073 u_int i; 1074 u_char ch; 1075 char *s; 1076 int *escape_pendingp, escape_char; 1077 struct escape_filter_ctx *efc; 1078 1079 if (c == NULL) { 1080 escape_pendingp = &escape_pending1; 1081 escape_char = escape_char1; 1082 } else { 1083 if (c->filter_ctx == NULL) 1084 return 0; 1085 efc = (struct escape_filter_ctx *)c->filter_ctx; 1086 escape_pendingp = &efc->escape_pending; 1087 escape_char = efc->escape_char; 1088 } 1089 1090 if (len <= 0) 1091 return (0); 1092 1093 for (i = 0; i < (u_int)len; i++) { 1094 /* Get one character at a time. */ 1095 ch = buf[i]; 1096 1097 if (*escape_pendingp) { 1098 /* We have previously seen an escape character. */ 1099 /* Clear the flag now. */ 1100 *escape_pendingp = 0; 1101 1102 /* Process the escaped character. */ 1103 switch (ch) { 1104 case '.': 1105 /* Terminate the connection. */ 1106 snprintf(string, sizeof string, "%c.\r\n", 1107 escape_char); 1108 buffer_append(berr, string, strlen(string)); 1109 1110 if (c && c->ctl_chan != -1) { 1111 chan_read_failed(c); 1112 chan_write_failed(c); 1113 if (c->detach_user) 1114 c->detach_user(c->self, NULL); 1115 c->type = SSH_CHANNEL_ABANDONED; 1116 buffer_clear(&c->input); 1117 chan_ibuf_empty(c); 1118 return 0; 1119 } else 1120 quit_pending = 1; 1121 return -1; 1122 1123 case 'Z' - 64: 1124 /* XXX support this for mux clients */ 1125 if (c && c->ctl_chan != -1) { 1126 char b[16]; 1127 noescape: 1128 if (ch == 'Z' - 64) 1129 snprintf(b, sizeof b, "^Z"); 1130 else 1131 snprintf(b, sizeof b, "%c", ch); 1132 snprintf(string, sizeof string, 1133 "%c%s escape not available to " 1134 "multiplexed sessions\r\n", 1135 escape_char, b); 1136 buffer_append(berr, string, 1137 strlen(string)); 1138 continue; 1139 } 1140 /* Suspend the program. Inform the user */ 1141 snprintf(string, sizeof string, 1142 "%c^Z [suspend ssh]\r\n", escape_char); 1143 buffer_append(berr, string, strlen(string)); 1144 1145 /* Restore terminal modes and suspend. */ 1146 client_suspend_self(bin, bout, berr); 1147 1148 /* We have been continued. */ 1149 continue; 1150 1151 case 'B': 1152 if (compat20) { 1153 snprintf(string, sizeof string, 1154 "%cB\r\n", escape_char); 1155 buffer_append(berr, string, 1156 strlen(string)); 1157 channel_request_start(session_ident, 1158 "break", 0); 1159 packet_put_int(1000); 1160 packet_send(); 1161 } 1162 continue; 1163 1164 case 'R': 1165 if (compat20) { 1166 if (datafellows & SSH_BUG_NOREKEY) 1167 logit("Server does not " 1168 "support re-keying"); 1169 else 1170 need_rekeying = 1; 1171 } 1172 continue; 1173 1174 case 'V': 1175 /* FALLTHROUGH */ 1176 case 'v': 1177 if (c && c->ctl_chan != -1) 1178 goto noescape; 1179 if (!log_is_on_stderr()) { 1180 snprintf(string, sizeof string, 1181 "%c%c [Logging to syslog]\r\n", 1182 escape_char, ch); 1183 buffer_append(berr, string, 1184 strlen(string)); 1185 continue; 1186 } 1187 if (ch == 'V' && options.log_level > 1188 SYSLOG_LEVEL_QUIET) 1189 log_change_level(--options.log_level); 1190 if (ch == 'v' && options.log_level < 1191 SYSLOG_LEVEL_DEBUG3) 1192 log_change_level(++options.log_level); 1193 snprintf(string, sizeof string, 1194 "%c%c [LogLevel %s]\r\n", escape_char, ch, 1195 log_level_name(options.log_level)); 1196 buffer_append(berr, string, strlen(string)); 1197 continue; 1198 1199 case '&': 1200 if (c && c->ctl_chan != -1) 1201 goto noescape; 1202 /* 1203 * Detach the program (continue to serve 1204 * connections, but put in background and no 1205 * more new connections). 1206 */ 1207 /* Restore tty modes. */ 1208 leave_raw_mode( 1209 options.request_tty == REQUEST_TTY_FORCE); 1210 1211 /* Stop listening for new connections. */ 1212 channel_stop_listening(); 1213 1214 snprintf(string, sizeof string, 1215 "%c& [backgrounded]\n", escape_char); 1216 buffer_append(berr, string, strlen(string)); 1217 1218 /* Fork into background. */ 1219 pid = fork(); 1220 if (pid < 0) { 1221 error("fork: %.100s", strerror(errno)); 1222 continue; 1223 } 1224 if (pid != 0) { /* This is the parent. */ 1225 /* The parent just exits. */ 1226 exit(0); 1227 } 1228 /* The child continues serving connections. */ 1229 if (compat20) { 1230 buffer_append(bin, "\004", 1); 1231 /* fake EOF on stdin */ 1232 return -1; 1233 } else if (!stdin_eof) { 1234 /* 1235 * Sending SSH_CMSG_EOF alone does not 1236 * always appear to be enough. So we 1237 * try to send an EOF character first. 1238 */ 1239 packet_start(SSH_CMSG_STDIN_DATA); 1240 packet_put_string("\004", 1); 1241 packet_send(); 1242 /* Close stdin. */ 1243 stdin_eof = 1; 1244 if (buffer_len(bin) == 0) { 1245 packet_start(SSH_CMSG_EOF); 1246 packet_send(); 1247 } 1248 } 1249 continue; 1250 1251 case '?': 1252 print_escape_help(berr, escape_char, compat20, 1253 (c && c->ctl_chan != -1), 1254 log_is_on_stderr()); 1255 continue; 1256 1257 case '#': 1258 snprintf(string, sizeof string, "%c#\r\n", 1259 escape_char); 1260 buffer_append(berr, string, strlen(string)); 1261 s = channel_open_message(); 1262 buffer_append(berr, s, strlen(s)); 1263 free(s); 1264 continue; 1265 1266 case 'C': 1267 if (c && c->ctl_chan != -1) 1268 goto noescape; 1269 process_cmdline(); 1270 continue; 1271 1272 default: 1273 if (ch != escape_char) { 1274 buffer_put_char(bin, escape_char); 1275 bytes++; 1276 } 1277 /* Escaped characters fall through here */ 1278 break; 1279 } 1280 } else { 1281 /* 1282 * The previous character was not an escape char. 1283 * Check if this is an escape. 1284 */ 1285 if (last_was_cr && ch == escape_char) { 1286 /* 1287 * It is. Set the flag and continue to 1288 * next character. 1289 */ 1290 *escape_pendingp = 1; 1291 continue; 1292 } 1293 } 1294 1295 /* 1296 * Normal character. Record whether it was a newline, 1297 * and append it to the buffer. 1298 */ 1299 last_was_cr = (ch == '\r' || ch == '\n'); 1300 buffer_put_char(bin, ch); 1301 bytes++; 1302 } 1303 return bytes; 1304 } 1305 1306 static void 1307 client_process_input(fd_set *readset) 1308 { 1309 int len; 1310 char buf[SSH_IOBUFSZ]; 1311 1312 /* Read input from stdin. */ 1313 if (FD_ISSET(fileno(stdin), readset)) { 1314 /* Read as much as possible. */ 1315 len = read(fileno(stdin), buf, sizeof(buf)); 1316 if (len < 0 && 1317 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1318 return; /* we'll try again later */ 1319 if (len <= 0) { 1320 /* 1321 * Received EOF or error. They are treated 1322 * similarly, except that an error message is printed 1323 * if it was an error condition. 1324 */ 1325 if (len < 0) { 1326 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1327 strerror(errno)); 1328 buffer_append(&stderr_buffer, buf, strlen(buf)); 1329 } 1330 /* Mark that we have seen EOF. */ 1331 stdin_eof = 1; 1332 /* 1333 * Send an EOF message to the server unless there is 1334 * data in the buffer. If there is data in the 1335 * buffer, no message will be sent now. Code 1336 * elsewhere will send the EOF when the buffer 1337 * becomes empty if stdin_eof is set. 1338 */ 1339 if (buffer_len(&stdin_buffer) == 0) { 1340 packet_start(SSH_CMSG_EOF); 1341 packet_send(); 1342 } 1343 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1344 /* 1345 * Normal successful read, and no escape character. 1346 * Just append the data to buffer. 1347 */ 1348 buffer_append(&stdin_buffer, buf, len); 1349 } else { 1350 /* 1351 * Normal, successful read. But we have an escape 1352 * character and have to process the characters one 1353 * by one. 1354 */ 1355 if (process_escapes(NULL, &stdin_buffer, 1356 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1357 return; 1358 } 1359 } 1360 } 1361 1362 static void 1363 client_process_output(fd_set *writeset) 1364 { 1365 int len; 1366 char buf[100]; 1367 1368 /* Write buffered output to stdout. */ 1369 if (FD_ISSET(fileno(stdout), writeset)) { 1370 /* Write as much data as possible. */ 1371 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1372 buffer_len(&stdout_buffer)); 1373 if (len <= 0) { 1374 if (errno == EINTR || errno == EAGAIN || 1375 errno == EWOULDBLOCK) 1376 len = 0; 1377 else { 1378 /* 1379 * An error or EOF was encountered. Put an 1380 * error message to stderr buffer. 1381 */ 1382 snprintf(buf, sizeof buf, 1383 "write stdout: %.50s\r\n", strerror(errno)); 1384 buffer_append(&stderr_buffer, buf, strlen(buf)); 1385 quit_pending = 1; 1386 return; 1387 } 1388 } 1389 /* Consume printed data from the buffer. */ 1390 buffer_consume(&stdout_buffer, len); 1391 } 1392 /* Write buffered output to stderr. */ 1393 if (FD_ISSET(fileno(stderr), writeset)) { 1394 /* Write as much data as possible. */ 1395 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1396 buffer_len(&stderr_buffer)); 1397 if (len <= 0) { 1398 if (errno == EINTR || errno == EAGAIN || 1399 errno == EWOULDBLOCK) 1400 len = 0; 1401 else { 1402 /* 1403 * EOF or error, but can't even print 1404 * error message. 1405 */ 1406 quit_pending = 1; 1407 return; 1408 } 1409 } 1410 /* Consume printed characters from the buffer. */ 1411 buffer_consume(&stderr_buffer, len); 1412 } 1413 } 1414 1415 /* 1416 * Get packets from the connection input buffer, and process them as long as 1417 * there are packets available. 1418 * 1419 * Any unknown packets received during the actual 1420 * session cause the session to terminate. This is 1421 * intended to make debugging easier since no 1422 * confirmations are sent. Any compatible protocol 1423 * extensions must be negotiated during the 1424 * preparatory phase. 1425 */ 1426 1427 static void 1428 client_process_buffered_input_packets(void) 1429 { 1430 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1431 compat20 ? xxx_kex : NULL); 1432 } 1433 1434 /* scan buf[] for '~' before sending data to the peer */ 1435 1436 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1437 void * 1438 client_new_escape_filter_ctx(int escape_char) 1439 { 1440 struct escape_filter_ctx *ret; 1441 1442 ret = xcalloc(1, sizeof(*ret)); 1443 ret->escape_pending = 0; 1444 ret->escape_char = escape_char; 1445 return (void *)ret; 1446 } 1447 1448 /* Free the escape filter context on channel free */ 1449 void 1450 client_filter_cleanup(int cid, void *ctx) 1451 { 1452 free(ctx); 1453 } 1454 1455 int 1456 client_simple_escape_filter(Channel *c, char *buf, int len) 1457 { 1458 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1459 return 0; 1460 1461 return process_escapes(c, &c->input, &c->output, &c->extended, 1462 buf, len); 1463 } 1464 1465 static void 1466 client_channel_closed(int id, void *arg) 1467 { 1468 channel_cancel_cleanup(id); 1469 session_closed = 1; 1470 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1471 } 1472 1473 /* 1474 * Implements the interactive session with the server. This is called after 1475 * the user has been authenticated, and a command has been started on the 1476 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1477 * used as an escape character for terminating or suspending the session. 1478 */ 1479 1480 int 1481 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1482 { 1483 fd_set *readset = NULL, *writeset = NULL; 1484 double start_time, total_time; 1485 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1486 u_int64_t ibytes, obytes; 1487 u_int nalloc = 0; 1488 char buf[100]; 1489 1490 debug("Entering interactive session."); 1491 1492 start_time = get_current_time(); 1493 1494 /* Initialize variables. */ 1495 escape_pending1 = 0; 1496 last_was_cr = 1; 1497 exit_status = -1; 1498 stdin_eof = 0; 1499 buffer_high = 64 * 1024; 1500 connection_in = packet_get_connection_in(); 1501 connection_out = packet_get_connection_out(); 1502 max_fd = MAX(connection_in, connection_out); 1503 1504 if (!compat20) { 1505 /* enable nonblocking unless tty */ 1506 if (!isatty(fileno(stdin))) 1507 set_nonblock(fileno(stdin)); 1508 if (!isatty(fileno(stdout))) 1509 set_nonblock(fileno(stdout)); 1510 if (!isatty(fileno(stderr))) 1511 set_nonblock(fileno(stderr)); 1512 max_fd = MAX(max_fd, fileno(stdin)); 1513 max_fd = MAX(max_fd, fileno(stdout)); 1514 max_fd = MAX(max_fd, fileno(stderr)); 1515 } 1516 quit_pending = 0; 1517 escape_char1 = escape_char_arg; 1518 1519 /* Initialize buffers. */ 1520 buffer_init(&stdin_buffer); 1521 buffer_init(&stdout_buffer); 1522 buffer_init(&stderr_buffer); 1523 1524 client_init_dispatch(); 1525 1526 /* 1527 * Set signal handlers, (e.g. to restore non-blocking mode) 1528 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1529 */ 1530 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1531 signal(SIGHUP, signal_handler); 1532 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1533 signal(SIGINT, signal_handler); 1534 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1535 signal(SIGQUIT, signal_handler); 1536 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1537 signal(SIGTERM, signal_handler); 1538 signal(SIGWINCH, window_change_handler); 1539 1540 if (have_pty) 1541 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1542 1543 if (compat20) { 1544 session_ident = ssh2_chan_id; 1545 if (session_ident != -1) { 1546 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1547 channel_register_filter(session_ident, 1548 client_simple_escape_filter, NULL, 1549 client_filter_cleanup, 1550 client_new_escape_filter_ctx( 1551 escape_char_arg)); 1552 } 1553 channel_register_cleanup(session_ident, 1554 client_channel_closed, 0); 1555 } 1556 } else { 1557 /* Check if we should immediately send eof on stdin. */ 1558 client_check_initial_eof_on_stdin(); 1559 } 1560 1561 /* Main loop of the client for the interactive session mode. */ 1562 while (!quit_pending) { 1563 1564 /* Process buffered packets sent by the server. */ 1565 client_process_buffered_input_packets(); 1566 1567 if (compat20 && session_closed && !channel_still_open()) 1568 break; 1569 1570 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1571 1572 if (rekeying) { 1573 debug("rekeying in progress"); 1574 } else { 1575 /* 1576 * Make packets of buffered stdin data, and buffer 1577 * them for sending to the server. 1578 */ 1579 if (!compat20) 1580 client_make_packets_from_stdin_data(); 1581 1582 /* 1583 * Make packets from buffered channel data, and 1584 * enqueue them for sending to the server. 1585 */ 1586 if (packet_not_very_much_data_to_write()) 1587 channel_output_poll(); 1588 1589 /* 1590 * Check if the window size has changed, and buffer a 1591 * message about it to the server if so. 1592 */ 1593 client_check_window_change(); 1594 1595 if (quit_pending) 1596 break; 1597 } 1598 /* 1599 * Wait until we have something to do (something becomes 1600 * available on one of the descriptors). 1601 */ 1602 max_fd2 = max_fd; 1603 client_wait_until_can_do_something(&readset, &writeset, 1604 &max_fd2, &nalloc, rekeying); 1605 1606 if (quit_pending) 1607 break; 1608 1609 /* Do channel operations unless rekeying in progress. */ 1610 if (!rekeying) { 1611 channel_after_select(readset, writeset); 1612 if (need_rekeying || packet_need_rekeying()) { 1613 debug("need rekeying"); 1614 xxx_kex->done = 0; 1615 kex_send_kexinit(xxx_kex); 1616 need_rekeying = 0; 1617 } 1618 } 1619 1620 /* Buffer input from the connection. */ 1621 client_process_net_input(readset); 1622 1623 if (quit_pending) 1624 break; 1625 1626 if (!compat20) { 1627 /* Buffer data from stdin */ 1628 client_process_input(readset); 1629 /* 1630 * Process output to stdout and stderr. Output to 1631 * the connection is processed elsewhere (above). 1632 */ 1633 client_process_output(writeset); 1634 } 1635 1636 if (session_resumed) { 1637 connection_in = packet_get_connection_in(); 1638 connection_out = packet_get_connection_out(); 1639 max_fd = MAX(max_fd, connection_out); 1640 max_fd = MAX(max_fd, connection_in); 1641 session_resumed = 0; 1642 } 1643 1644 /* 1645 * Send as much buffered packet data as possible to the 1646 * sender. 1647 */ 1648 if (FD_ISSET(connection_out, writeset)) 1649 packet_write_poll(); 1650 1651 /* 1652 * If we are a backgrounded control master, and the 1653 * timeout has expired without any active client 1654 * connections, then quit. 1655 */ 1656 if (control_persist_exit_time > 0) { 1657 if (monotime() >= control_persist_exit_time) { 1658 debug("ControlPersist timeout expired"); 1659 break; 1660 } 1661 } 1662 } 1663 free(readset); 1664 free(writeset); 1665 1666 /* Terminate the session. */ 1667 1668 /* Stop watching for window change. */ 1669 signal(SIGWINCH, SIG_DFL); 1670 1671 if (compat20) { 1672 packet_start(SSH2_MSG_DISCONNECT); 1673 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1674 packet_put_cstring("disconnected by user"); 1675 packet_put_cstring(""); /* language tag */ 1676 packet_send(); 1677 packet_write_wait(); 1678 } 1679 1680 channel_free_all(); 1681 1682 if (have_pty) 1683 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1684 1685 /* restore blocking io */ 1686 if (!isatty(fileno(stdin))) 1687 unset_nonblock(fileno(stdin)); 1688 if (!isatty(fileno(stdout))) 1689 unset_nonblock(fileno(stdout)); 1690 if (!isatty(fileno(stderr))) 1691 unset_nonblock(fileno(stderr)); 1692 1693 /* 1694 * If there was no shell or command requested, there will be no remote 1695 * exit status to be returned. In that case, clear error code if the 1696 * connection was deliberately terminated at this end. 1697 */ 1698 if (no_shell_flag && received_signal == SIGTERM) { 1699 received_signal = 0; 1700 exit_status = 0; 1701 } 1702 1703 if (received_signal) 1704 fatal("Killed by signal %d.", (int) received_signal); 1705 1706 /* 1707 * In interactive mode (with pseudo tty) display a message indicating 1708 * that the connection has been closed. 1709 */ 1710 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1711 snprintf(buf, sizeof buf, 1712 "Connection to %.64s closed.\r\n", host); 1713 buffer_append(&stderr_buffer, buf, strlen(buf)); 1714 } 1715 1716 /* Output any buffered data for stdout. */ 1717 if (buffer_len(&stdout_buffer) > 0) { 1718 len = atomicio(vwrite, fileno(stdout), 1719 buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer)); 1720 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer)) 1721 error("Write failed flushing stdout buffer."); 1722 else 1723 buffer_consume(&stdout_buffer, len); 1724 } 1725 1726 /* Output any buffered data for stderr. */ 1727 if (buffer_len(&stderr_buffer) > 0) { 1728 len = atomicio(vwrite, fileno(stderr), 1729 buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer)); 1730 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer)) 1731 error("Write failed flushing stderr buffer."); 1732 else 1733 buffer_consume(&stderr_buffer, len); 1734 } 1735 1736 /* Clear and free any buffers. */ 1737 memset(buf, 0, sizeof(buf)); 1738 buffer_free(&stdin_buffer); 1739 buffer_free(&stdout_buffer); 1740 buffer_free(&stderr_buffer); 1741 1742 /* Report bytes transferred, and transfer rates. */ 1743 total_time = get_current_time() - start_time; 1744 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1745 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1746 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1747 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1748 if (total_time > 0) 1749 verbose("Bytes per second: sent %.1f, received %.1f", 1750 obytes / total_time, ibytes / total_time); 1751 /* Return the exit status of the program. */ 1752 debug("Exit status %d", exit_status); 1753 return exit_status; 1754 } 1755 1756 /*********/ 1757 1758 static void 1759 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1760 { 1761 u_int data_len; 1762 char *data = packet_get_string(&data_len); 1763 packet_check_eom(); 1764 buffer_append(&stdout_buffer, data, data_len); 1765 memset(data, 0, data_len); 1766 free(data); 1767 } 1768 static void 1769 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1770 { 1771 u_int data_len; 1772 char *data = packet_get_string(&data_len); 1773 packet_check_eom(); 1774 buffer_append(&stderr_buffer, data, data_len); 1775 memset(data, 0, data_len); 1776 free(data); 1777 } 1778 static void 1779 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1780 { 1781 exit_status = packet_get_int(); 1782 packet_check_eom(); 1783 /* Acknowledge the exit. */ 1784 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1785 packet_send(); 1786 /* 1787 * Must wait for packet to be sent since we are 1788 * exiting the loop. 1789 */ 1790 packet_write_wait(); 1791 /* Flag that we want to exit. */ 1792 quit_pending = 1; 1793 } 1794 static void 1795 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1796 { 1797 Channel *c = NULL; 1798 int remote_id, sock; 1799 1800 /* Read the remote channel number from the message. */ 1801 remote_id = packet_get_int(); 1802 packet_check_eom(); 1803 1804 /* 1805 * Get a connection to the local authentication agent (this may again 1806 * get forwarded). 1807 */ 1808 sock = ssh_get_authentication_socket(); 1809 1810 /* 1811 * If we could not connect the agent, send an error message back to 1812 * the server. This should never happen unless the agent dies, 1813 * because authentication forwarding is only enabled if we have an 1814 * agent. 1815 */ 1816 if (sock >= 0) { 1817 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1818 -1, 0, 0, 0, "authentication agent connection", 1); 1819 c->remote_id = remote_id; 1820 c->force_drain = 1; 1821 } 1822 if (c == NULL) { 1823 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1824 packet_put_int(remote_id); 1825 } else { 1826 /* Send a confirmation to the remote host. */ 1827 debug("Forwarding authentication connection."); 1828 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1829 packet_put_int(remote_id); 1830 packet_put_int(c->self); 1831 } 1832 packet_send(); 1833 } 1834 1835 static Channel * 1836 client_request_forwarded_tcpip(const char *request_type, int rchan) 1837 { 1838 Channel *c = NULL; 1839 char *listen_address, *originator_address; 1840 u_short listen_port, originator_port; 1841 1842 /* Get rest of the packet */ 1843 listen_address = packet_get_string(NULL); 1844 listen_port = packet_get_int(); 1845 originator_address = packet_get_string(NULL); 1846 originator_port = packet_get_int(); 1847 packet_check_eom(); 1848 1849 debug("client_request_forwarded_tcpip: listen %s port %d, " 1850 "originator %s port %d", listen_address, listen_port, 1851 originator_address, originator_port); 1852 1853 c = channel_connect_by_listen_address(listen_port, 1854 "forwarded-tcpip", originator_address); 1855 1856 free(originator_address); 1857 free(listen_address); 1858 return c; 1859 } 1860 1861 static Channel * 1862 client_request_x11(const char *request_type, int rchan) 1863 { 1864 Channel *c = NULL; 1865 char *originator; 1866 u_short originator_port; 1867 int sock; 1868 1869 if (!options.forward_x11) { 1870 error("Warning: ssh server tried X11 forwarding."); 1871 error("Warning: this is probably a break-in attempt by a " 1872 "malicious server."); 1873 return NULL; 1874 } 1875 if (x11_refuse_time != 0 && monotime() >= x11_refuse_time) { 1876 verbose("Rejected X11 connection after ForwardX11Timeout " 1877 "expired"); 1878 return NULL; 1879 } 1880 originator = packet_get_string(NULL); 1881 if (datafellows & SSH_BUG_X11FWD) { 1882 debug2("buggy server: x11 request w/o originator_port"); 1883 originator_port = 0; 1884 } else { 1885 originator_port = packet_get_int(); 1886 } 1887 packet_check_eom(); 1888 /* XXX check permission */ 1889 debug("client_request_x11: request from %s %d", originator, 1890 originator_port); 1891 free(originator); 1892 sock = x11_connect_display(); 1893 if (sock < 0) 1894 return NULL; 1895 if (options.hpn_disabled) 1896 c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1897 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 1898 0, "x11", 1); 1899 else 1900 c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1901 options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 1902 0, "x11", 1); 1903 c->force_drain = 1; 1904 return c; 1905 } 1906 1907 static Channel * 1908 client_request_agent(const char *request_type, int rchan) 1909 { 1910 Channel *c = NULL; 1911 int sock; 1912 1913 if (!options.forward_agent) { 1914 error("Warning: ssh server tried agent forwarding."); 1915 error("Warning: this is probably a break-in attempt by a " 1916 "malicious server."); 1917 return NULL; 1918 } 1919 sock = ssh_get_authentication_socket(); 1920 if (sock < 0) 1921 return NULL; 1922 if (options.hpn_disabled) 1923 c = channel_new("authentication agent connection", 1924 SSH_CHANNEL_OPEN, sock, sock, -1, 1925 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, 1926 "authentication agent connection", 1); 1927 else 1928 c = channel_new("authentication agent connection", 1929 SSH_CHANNEL_OPEN, sock, sock, -1, 1930 options.hpn_buffer_size, options.hpn_buffer_size, 0, 1931 "authentication agent connection", 1); 1932 c->force_drain = 1; 1933 return c; 1934 } 1935 1936 int 1937 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1938 { 1939 Channel *c; 1940 int fd; 1941 1942 if (tun_mode == SSH_TUNMODE_NO) 1943 return 0; 1944 1945 if (!compat20) { 1946 error("Tunnel forwarding is not supported for protocol 1"); 1947 return -1; 1948 } 1949 1950 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1951 1952 /* Open local tunnel device */ 1953 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1954 error("Tunnel device open failed."); 1955 return -1; 1956 } 1957 1958 if (options.hpn_disabled) 1959 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1960 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 1961 0, "tun", 1); 1962 else 1963 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1964 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 1965 0, "tun", 1); 1966 c->datagram = 1; 1967 1968 #if defined(SSH_TUN_FILTER) 1969 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1970 channel_register_filter(c->self, sys_tun_infilter, 1971 sys_tun_outfilter, NULL, NULL); 1972 #endif 1973 1974 packet_start(SSH2_MSG_CHANNEL_OPEN); 1975 packet_put_cstring("tun@openssh.com"); 1976 packet_put_int(c->self); 1977 packet_put_int(c->local_window_max); 1978 packet_put_int(c->local_maxpacket); 1979 packet_put_int(tun_mode); 1980 packet_put_int(remote_tun); 1981 packet_send(); 1982 1983 return 0; 1984 } 1985 1986 /* XXXX move to generic input handler */ 1987 static void 1988 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1989 { 1990 Channel *c = NULL; 1991 char *ctype; 1992 int rchan; 1993 u_int rmaxpack, rwindow, len; 1994 1995 ctype = packet_get_string(&len); 1996 rchan = packet_get_int(); 1997 rwindow = packet_get_int(); 1998 rmaxpack = packet_get_int(); 1999 2000 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 2001 ctype, rchan, rwindow, rmaxpack); 2002 2003 if (strcmp(ctype, "forwarded-tcpip") == 0) { 2004 c = client_request_forwarded_tcpip(ctype, rchan); 2005 } else if (strcmp(ctype, "x11") == 0) { 2006 c = client_request_x11(ctype, rchan); 2007 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 2008 c = client_request_agent(ctype, rchan); 2009 } 2010 /* XXX duplicate : */ 2011 if (c != NULL) { 2012 debug("confirm %s", ctype); 2013 c->remote_id = rchan; 2014 c->remote_window = rwindow; 2015 c->remote_maxpacket = rmaxpack; 2016 if (c->type != SSH_CHANNEL_CONNECTING) { 2017 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 2018 packet_put_int(c->remote_id); 2019 packet_put_int(c->self); 2020 packet_put_int(c->local_window); 2021 packet_put_int(c->local_maxpacket); 2022 packet_send(); 2023 } 2024 } else { 2025 debug("failure %s", ctype); 2026 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 2027 packet_put_int(rchan); 2028 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 2029 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 2030 packet_put_cstring("open failed"); 2031 packet_put_cstring(""); 2032 } 2033 packet_send(); 2034 } 2035 free(ctype); 2036 } 2037 static void 2038 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 2039 { 2040 Channel *c = NULL; 2041 int exitval, id, reply, success = 0; 2042 char *rtype; 2043 2044 id = packet_get_int(); 2045 rtype = packet_get_string(NULL); 2046 reply = packet_get_char(); 2047 2048 debug("client_input_channel_req: channel %d rtype %s reply %d", 2049 id, rtype, reply); 2050 2051 if (id == -1) { 2052 error("client_input_channel_req: request for channel -1"); 2053 } else if ((c = channel_lookup(id)) == NULL) { 2054 error("client_input_channel_req: channel %d: " 2055 "unknown channel", id); 2056 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 2057 packet_check_eom(); 2058 chan_rcvd_eow(c); 2059 } else if (strcmp(rtype, "exit-status") == 0) { 2060 exitval = packet_get_int(); 2061 if (c->ctl_chan != -1) { 2062 mux_exit_message(c, exitval); 2063 success = 1; 2064 } else if (id == session_ident) { 2065 /* Record exit value of local session */ 2066 success = 1; 2067 exit_status = exitval; 2068 } else { 2069 /* Probably for a mux channel that has already closed */ 2070 debug("%s: no sink for exit-status on channel %d", 2071 __func__, id); 2072 } 2073 packet_check_eom(); 2074 } 2075 if (reply && c != NULL) { 2076 packet_start(success ? 2077 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 2078 packet_put_int(c->remote_id); 2079 packet_send(); 2080 } 2081 free(rtype); 2082 } 2083 static void 2084 client_input_global_request(int type, u_int32_t seq, void *ctxt) 2085 { 2086 char *rtype; 2087 int want_reply; 2088 int success = 0; 2089 2090 rtype = packet_get_string(NULL); 2091 want_reply = packet_get_char(); 2092 debug("client_input_global_request: rtype %s want_reply %d", 2093 rtype, want_reply); 2094 if (want_reply) { 2095 packet_start(success ? 2096 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 2097 packet_send(); 2098 packet_write_wait(); 2099 } 2100 free(rtype); 2101 } 2102 2103 void 2104 client_session2_setup(int id, int want_tty, int want_subsystem, 2105 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 2106 { 2107 int len; 2108 Channel *c = NULL; 2109 2110 debug2("%s: id %d", __func__, id); 2111 2112 if ((c = channel_lookup(id)) == NULL) 2113 fatal("client_session2_setup: channel %d: unknown channel", id); 2114 2115 packet_set_interactive(want_tty, 2116 options.ip_qos_interactive, options.ip_qos_bulk); 2117 2118 if (want_tty) { 2119 struct winsize ws; 2120 2121 /* Store window size in the packet. */ 2122 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 2123 memset(&ws, 0, sizeof(ws)); 2124 2125 channel_request_start(id, "pty-req", 1); 2126 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); 2127 packet_put_cstring(term != NULL ? term : ""); 2128 packet_put_int((u_int)ws.ws_col); 2129 packet_put_int((u_int)ws.ws_row); 2130 packet_put_int((u_int)ws.ws_xpixel); 2131 packet_put_int((u_int)ws.ws_ypixel); 2132 if (tiop == NULL) 2133 tiop = get_saved_tio(); 2134 tty_make_modes(-1, tiop); 2135 packet_send(); 2136 /* XXX wait for reply */ 2137 c->client_tty = 1; 2138 } 2139 2140 /* Transfer any environment variables from client to server */ 2141 if (options.num_send_env != 0 && env != NULL) { 2142 int i, j, matched; 2143 char *name, *val; 2144 2145 debug("Sending environment."); 2146 for (i = 0; env[i] != NULL; i++) { 2147 /* Split */ 2148 name = xstrdup(env[i]); 2149 if ((val = strchr(name, '=')) == NULL) { 2150 free(name); 2151 continue; 2152 } 2153 *val++ = '\0'; 2154 2155 matched = 0; 2156 for (j = 0; j < options.num_send_env; j++) { 2157 if (match_pattern(name, options.send_env[j])) { 2158 matched = 1; 2159 break; 2160 } 2161 } 2162 if (!matched) { 2163 debug3("Ignored env %s", name); 2164 free(name); 2165 continue; 2166 } 2167 2168 debug("Sending env %s = %s", name, val); 2169 channel_request_start(id, "env", 0); 2170 packet_put_cstring(name); 2171 packet_put_cstring(val); 2172 packet_send(); 2173 free(name); 2174 } 2175 } 2176 2177 len = buffer_len(cmd); 2178 if (len > 0) { 2179 if (len > 900) 2180 len = 900; 2181 if (want_subsystem) { 2182 debug("Sending subsystem: %.*s", 2183 len, (u_char*)buffer_ptr(cmd)); 2184 channel_request_start(id, "subsystem", 1); 2185 client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); 2186 } else { 2187 debug("Sending command: %.*s", 2188 len, (u_char*)buffer_ptr(cmd)); 2189 channel_request_start(id, "exec", 1); 2190 client_expect_confirm(id, "exec", CONFIRM_CLOSE); 2191 } 2192 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 2193 packet_send(); 2194 } else { 2195 channel_request_start(id, "shell", 1); 2196 client_expect_confirm(id, "shell", CONFIRM_CLOSE); 2197 packet_send(); 2198 } 2199 } 2200 2201 static void 2202 client_init_dispatch_20(void) 2203 { 2204 dispatch_init(&dispatch_protocol_error); 2205 2206 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2207 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2208 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2209 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2210 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2211 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2212 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2213 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2214 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2215 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2216 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2217 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2218 2219 /* rekeying */ 2220 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2221 2222 /* global request reply messages */ 2223 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2224 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2225 } 2226 2227 static void 2228 client_init_dispatch_13(void) 2229 { 2230 dispatch_init(NULL); 2231 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2232 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2233 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2234 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2235 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2236 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2237 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2238 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2239 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2240 2241 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2242 &client_input_agent_open : &deny_input_open); 2243 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2244 &x11_input_open : &deny_input_open); 2245 } 2246 2247 static void 2248 client_init_dispatch_15(void) 2249 { 2250 client_init_dispatch_13(); 2251 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2252 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2253 } 2254 2255 static void 2256 client_init_dispatch(void) 2257 { 2258 if (compat20) 2259 client_init_dispatch_20(); 2260 else if (compat13) 2261 client_init_dispatch_13(); 2262 else 2263 client_init_dispatch_15(); 2264 } 2265 2266 void 2267 client_stop_mux(void) 2268 { 2269 if (options.control_path != NULL && muxserver_sock != -1) 2270 unlink(options.control_path); 2271 /* 2272 * If we are in persist mode, or don't have a shell, signal that we 2273 * should close when all active channels are closed. 2274 */ 2275 if (options.control_persist || no_shell_flag) { 2276 session_closed = 1; 2277 setproctitle("[stopped mux]"); 2278 } 2279 } 2280 2281 /* client specific fatal cleanup */ 2282 void 2283 cleanup_exit(int i) 2284 { 2285 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2286 leave_non_blocking(); 2287 if (options.control_path != NULL && muxserver_sock != -1) 2288 unlink(options.control_path); 2289 ssh_kill_proxy_command(); 2290 _exit(i); 2291 } 2292