1 /* $OpenBSD: clientloop.c,v 1.201 2008/07/16 11:51:14 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * The main loop for the interactive session (client side). 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * 15 * Copyright (c) 1999 Theo de Raadt. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * 38 * SSH2 support added by Markus Friedl. 39 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 51 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 52 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 53 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 54 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 55 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 56 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 57 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 58 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 59 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 63 #include <sys/types.h> 64 #include <sys/ioctl.h> 65 #include <sys/stat.h> 66 #include <sys/socket.h> 67 #include <sys/time.h> 68 #include <sys/param.h> 69 #include <sys/queue.h> 70 71 #include <ctype.h> 72 #include <errno.h> 73 #include <paths.h> 74 #include <signal.h> 75 #include <stdio.h> 76 #include <stdlib.h> 77 #include <string.h> 78 #include <termios.h> 79 #include <pwd.h> 80 #include <unistd.h> 81 82 #include "xmalloc.h" 83 #include "ssh.h" 84 #include "ssh1.h" 85 #include "ssh2.h" 86 #include "packet.h" 87 #include "buffer.h" 88 #include "compat.h" 89 #include "channels.h" 90 #include "dispatch.h" 91 #include "key.h" 92 #include "cipher.h" 93 #include "kex.h" 94 #include "log.h" 95 #include "readconf.h" 96 #include "clientloop.h" 97 #include "sshconnect.h" 98 #include "authfd.h" 99 #include "atomicio.h" 100 #include "sshpty.h" 101 #include "misc.h" 102 #include "monitor_fdpass.h" 103 #include "match.h" 104 #include "msg.h" 105 106 /* import options */ 107 extern Options options; 108 109 /* Flag indicating that stdin should be redirected from /dev/null. */ 110 extern int stdin_null_flag; 111 112 /* Flag indicating that no shell has been requested */ 113 extern int no_shell_flag; 114 115 /* Control socket */ 116 extern int muxserver_sock; 117 118 /* 119 * Name of the host we are connecting to. This is the name given on the 120 * command line, or the HostName specified for the user-supplied name in a 121 * configuration file. 122 */ 123 extern char *host; 124 125 /* 126 * Flag to indicate that we have received a window change signal which has 127 * not yet been processed. This will cause a message indicating the new 128 * window size to be sent to the server a little later. This is volatile 129 * because this is updated in a signal handler. 130 */ 131 static volatile sig_atomic_t received_window_change_signal = 0; 132 static volatile sig_atomic_t received_signal = 0; 133 134 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 135 static int in_non_blocking_mode = 0; 136 137 /* Common data for the client loop code. */ 138 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 139 static int escape_char1; /* Escape character. (proto1 only) */ 140 static int escape_pending1; /* Last character was an escape (proto1 only) */ 141 static int last_was_cr; /* Last character was a newline. */ 142 static int exit_status; /* Used to store the command exit status. */ 143 static int stdin_eof; /* EOF has been encountered on stderr. */ 144 static Buffer stdin_buffer; /* Buffer for stdin data. */ 145 static Buffer stdout_buffer; /* Buffer for stdout data. */ 146 static Buffer stderr_buffer; /* Buffer for stderr data. */ 147 static u_int buffer_high;/* Soft max buffer size. */ 148 static int connection_in; /* Connection to server (input). */ 149 static int connection_out; /* Connection to server (output). */ 150 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 151 static int session_closed = 0; /* In SSH2: login session closed. */ 152 153 static void client_init_dispatch(void); 154 int session_ident = -1; 155 156 /* Track escape per proto2 channel */ 157 struct escape_filter_ctx { 158 int escape_pending; 159 int escape_char; 160 }; 161 162 /* Context for channel confirmation replies */ 163 struct channel_reply_ctx { 164 const char *request_type; 165 int id, do_close; 166 }; 167 168 /* Global request success/failure callbacks */ 169 struct global_confirm { 170 TAILQ_ENTRY(global_confirm) entry; 171 global_confirm_cb *cb; 172 void *ctx; 173 int ref_count; 174 }; 175 TAILQ_HEAD(global_confirms, global_confirm); 176 static struct global_confirms global_confirms = 177 TAILQ_HEAD_INITIALIZER(global_confirms); 178 179 /*XXX*/ 180 extern Kex *xxx_kex; 181 182 void ssh_process_session2_setup(int, int, int, Buffer *); 183 184 /* Restores stdin to blocking mode. */ 185 186 static void 187 leave_non_blocking(void) 188 { 189 if (in_non_blocking_mode) { 190 unset_nonblock(fileno(stdin)); 191 in_non_blocking_mode = 0; 192 } 193 } 194 195 /* Puts stdin terminal in non-blocking mode. */ 196 197 static void 198 enter_non_blocking(void) 199 { 200 in_non_blocking_mode = 1; 201 set_nonblock(fileno(stdin)); 202 } 203 204 /* 205 * Signal handler for the window change signal (SIGWINCH). This just sets a 206 * flag indicating that the window has changed. 207 */ 208 /*ARGSUSED */ 209 static void 210 window_change_handler(int sig) 211 { 212 received_window_change_signal = 1; 213 signal(SIGWINCH, window_change_handler); 214 } 215 216 /* 217 * Signal handler for signals that cause the program to terminate. These 218 * signals must be trapped to restore terminal modes. 219 */ 220 /*ARGSUSED */ 221 static void 222 signal_handler(int sig) 223 { 224 received_signal = sig; 225 quit_pending = 1; 226 } 227 228 /* 229 * Returns current time in seconds from Jan 1, 1970 with the maximum 230 * available resolution. 231 */ 232 233 static double 234 get_current_time(void) 235 { 236 struct timeval tv; 237 gettimeofday(&tv, NULL); 238 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 239 } 240 241 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 242 void 243 client_x11_get_proto(const char *display, const char *xauth_path, 244 u_int trusted, char **_proto, char **_data) 245 { 246 char cmd[1024]; 247 char line[512]; 248 char xdisplay[512]; 249 static char proto[512], data[512]; 250 FILE *f; 251 int got_data = 0, generated = 0, do_unlink = 0, i; 252 char *xauthdir, *xauthfile; 253 struct stat st; 254 255 xauthdir = xauthfile = NULL; 256 *_proto = proto; 257 *_data = data; 258 proto[0] = data[0] = '\0'; 259 260 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 261 debug("No xauth program."); 262 } else { 263 if (display == NULL) { 264 debug("x11_get_proto: DISPLAY not set"); 265 return; 266 } 267 /* 268 * Handle FamilyLocal case where $DISPLAY does 269 * not match an authorization entry. For this we 270 * just try "xauth list unix:displaynum.screennum". 271 * XXX: "localhost" match to determine FamilyLocal 272 * is not perfect. 273 */ 274 if (strncmp(display, "localhost:", 10) == 0) { 275 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 276 display + 10); 277 display = xdisplay; 278 } 279 if (trusted == 0) { 280 xauthdir = xmalloc(MAXPATHLEN); 281 xauthfile = xmalloc(MAXPATHLEN); 282 strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); 283 if (mkdtemp(xauthdir) != NULL) { 284 do_unlink = 1; 285 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", 286 xauthdir); 287 snprintf(cmd, sizeof(cmd), 288 "%s -f %s generate %s " SSH_X11_PROTO 289 " untrusted timeout 1200 2>" _PATH_DEVNULL, 290 xauth_path, xauthfile, display); 291 debug2("x11_get_proto: %s", cmd); 292 if (system(cmd) == 0) 293 generated = 1; 294 } 295 } 296 297 /* 298 * When in untrusted mode, we read the cookie only if it was 299 * successfully generated as an untrusted one in the step 300 * above. 301 */ 302 if (trusted || generated) { 303 snprintf(cmd, sizeof(cmd), 304 "%s %s%s list %s 2>" _PATH_DEVNULL, 305 xauth_path, 306 generated ? "-f " : "" , 307 generated ? xauthfile : "", 308 display); 309 debug2("x11_get_proto: %s", cmd); 310 f = popen(cmd, "r"); 311 if (f && fgets(line, sizeof(line), f) && 312 sscanf(line, "%*s %511s %511s", proto, data) == 2) 313 got_data = 1; 314 if (f) 315 pclose(f); 316 } else 317 error("Warning: untrusted X11 forwarding setup failed: " 318 "xauth key data not generated"); 319 } 320 321 if (do_unlink) { 322 unlink(xauthfile); 323 rmdir(xauthdir); 324 } 325 if (xauthdir) 326 xfree(xauthdir); 327 if (xauthfile) 328 xfree(xauthfile); 329 330 /* 331 * If we didn't get authentication data, just make up some 332 * data. The forwarding code will check the validity of the 333 * response anyway, and substitute this data. The X11 334 * server, however, will ignore this fake data and use 335 * whatever authentication mechanisms it was using otherwise 336 * for the local connection. 337 */ 338 if (!got_data) { 339 u_int32_t rnd = 0; 340 341 logit("Warning: No xauth data; " 342 "using fake authentication data for X11 forwarding."); 343 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 344 for (i = 0; i < 16; i++) { 345 if (i % 4 == 0) 346 rnd = arc4random(); 347 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 348 rnd & 0xff); 349 rnd >>= 8; 350 } 351 } 352 } 353 354 /* 355 * This is called when the interactive is entered. This checks if there is 356 * an EOF coming on stdin. We must check this explicitly, as select() does 357 * not appear to wake up when redirecting from /dev/null. 358 */ 359 360 static void 361 client_check_initial_eof_on_stdin(void) 362 { 363 int len; 364 char buf[1]; 365 366 /* 367 * If standard input is to be "redirected from /dev/null", we simply 368 * mark that we have seen an EOF and send an EOF message to the 369 * server. Otherwise, we try to read a single character; it appears 370 * that for some files, such /dev/null, select() never wakes up for 371 * read for this descriptor, which means that we never get EOF. This 372 * way we will get the EOF if stdin comes from /dev/null or similar. 373 */ 374 if (stdin_null_flag) { 375 /* Fake EOF on stdin. */ 376 debug("Sending eof."); 377 stdin_eof = 1; 378 packet_start(SSH_CMSG_EOF); 379 packet_send(); 380 } else { 381 enter_non_blocking(); 382 383 /* Check for immediate EOF on stdin. */ 384 len = read(fileno(stdin), buf, 1); 385 if (len == 0) { 386 /* 387 * EOF. Record that we have seen it and send 388 * EOF to server. 389 */ 390 debug("Sending eof."); 391 stdin_eof = 1; 392 packet_start(SSH_CMSG_EOF); 393 packet_send(); 394 } else if (len > 0) { 395 /* 396 * Got data. We must store the data in the buffer, 397 * and also process it as an escape character if 398 * appropriate. 399 */ 400 if ((u_char) buf[0] == escape_char1) 401 escape_pending1 = 1; 402 else 403 buffer_append(&stdin_buffer, buf, 1); 404 } 405 leave_non_blocking(); 406 } 407 } 408 409 410 /* 411 * Make packets from buffered stdin data, and buffer them for sending to the 412 * connection. 413 */ 414 415 static void 416 client_make_packets_from_stdin_data(void) 417 { 418 u_int len; 419 420 /* Send buffered stdin data to the server. */ 421 while (buffer_len(&stdin_buffer) > 0 && 422 packet_not_very_much_data_to_write()) { 423 len = buffer_len(&stdin_buffer); 424 /* Keep the packets at reasonable size. */ 425 if (len > packet_get_maxsize()) 426 len = packet_get_maxsize(); 427 packet_start(SSH_CMSG_STDIN_DATA); 428 packet_put_string(buffer_ptr(&stdin_buffer), len); 429 packet_send(); 430 buffer_consume(&stdin_buffer, len); 431 /* If we have a pending EOF, send it now. */ 432 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 433 packet_start(SSH_CMSG_EOF); 434 packet_send(); 435 } 436 } 437 } 438 439 /* 440 * Checks if the client window has changed, and sends a packet about it to 441 * the server if so. The actual change is detected elsewhere (by a software 442 * interrupt on Unix); this just checks the flag and sends a message if 443 * appropriate. 444 */ 445 446 static void 447 client_check_window_change(void) 448 { 449 struct winsize ws; 450 451 if (! received_window_change_signal) 452 return; 453 /** XXX race */ 454 received_window_change_signal = 0; 455 456 debug2("client_check_window_change: changed"); 457 458 if (compat20) { 459 channel_send_window_changes(); 460 } else { 461 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 462 return; 463 packet_start(SSH_CMSG_WINDOW_SIZE); 464 packet_put_int((u_int)ws.ws_row); 465 packet_put_int((u_int)ws.ws_col); 466 packet_put_int((u_int)ws.ws_xpixel); 467 packet_put_int((u_int)ws.ws_ypixel); 468 packet_send(); 469 } 470 } 471 472 static void 473 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 474 { 475 struct global_confirm *gc; 476 477 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 478 return; 479 if (gc->cb != NULL) 480 gc->cb(type, seq, gc->ctx); 481 if (--gc->ref_count <= 0) { 482 TAILQ_REMOVE(&global_confirms, gc, entry); 483 bzero(gc, sizeof(*gc)); 484 xfree(gc); 485 } 486 487 keep_alive_timeouts = 0; 488 } 489 490 static void 491 server_alive_check(void) 492 { 493 if (++keep_alive_timeouts > options.server_alive_count_max) { 494 logit("Timeout, server not responding."); 495 cleanup_exit(255); 496 } 497 packet_start(SSH2_MSG_GLOBAL_REQUEST); 498 packet_put_cstring("keepalive@openssh.com"); 499 packet_put_char(1); /* boolean: want reply */ 500 packet_send(); 501 /* Insert an empty placeholder to maintain ordering */ 502 client_register_global_confirm(NULL, NULL); 503 } 504 505 /* 506 * Waits until the client can do something (some data becomes available on 507 * one of the file descriptors). 508 */ 509 static void 510 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 511 int *maxfdp, u_int *nallocp, int rekeying) 512 { 513 struct timeval tv, *tvp; 514 int ret; 515 516 /* Add any selections by the channel mechanism. */ 517 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); 518 519 if (!compat20) { 520 /* Read from the connection, unless our buffers are full. */ 521 if (buffer_len(&stdout_buffer) < buffer_high && 522 buffer_len(&stderr_buffer) < buffer_high && 523 channel_not_very_much_buffered_data()) 524 FD_SET(connection_in, *readsetp); 525 /* 526 * Read from stdin, unless we have seen EOF or have very much 527 * buffered data to send to the server. 528 */ 529 if (!stdin_eof && packet_not_very_much_data_to_write()) 530 FD_SET(fileno(stdin), *readsetp); 531 532 /* Select stdout/stderr if have data in buffer. */ 533 if (buffer_len(&stdout_buffer) > 0) 534 FD_SET(fileno(stdout), *writesetp); 535 if (buffer_len(&stderr_buffer) > 0) 536 FD_SET(fileno(stderr), *writesetp); 537 } else { 538 /* channel_prepare_select could have closed the last channel */ 539 if (session_closed && !channel_still_open() && 540 !packet_have_data_to_write()) { 541 /* clear mask since we did not call select() */ 542 memset(*readsetp, 0, *nallocp); 543 memset(*writesetp, 0, *nallocp); 544 return; 545 } else { 546 FD_SET(connection_in, *readsetp); 547 } 548 } 549 550 /* Select server connection if have data to write to the server. */ 551 if (packet_have_data_to_write()) 552 FD_SET(connection_out, *writesetp); 553 554 if (muxserver_sock != -1) 555 FD_SET(muxserver_sock, *readsetp); 556 557 /* 558 * Wait for something to happen. This will suspend the process until 559 * some selected descriptor can be read, written, or has some other 560 * event pending. 561 */ 562 563 if (options.server_alive_interval == 0 || !compat20) 564 tvp = NULL; 565 else { 566 tv.tv_sec = options.server_alive_interval; 567 tv.tv_usec = 0; 568 tvp = &tv; 569 } 570 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 571 if (ret < 0) { 572 char buf[100]; 573 574 /* 575 * We have to clear the select masks, because we return. 576 * We have to return, because the mainloop checks for the flags 577 * set by the signal handlers. 578 */ 579 memset(*readsetp, 0, *nallocp); 580 memset(*writesetp, 0, *nallocp); 581 582 if (errno == EINTR) 583 return; 584 /* Note: we might still have data in the buffers. */ 585 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 586 buffer_append(&stderr_buffer, buf, strlen(buf)); 587 quit_pending = 1; 588 } else if (ret == 0) 589 server_alive_check(); 590 } 591 592 static void 593 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 594 { 595 /* Flush stdout and stderr buffers. */ 596 if (buffer_len(bout) > 0) 597 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 598 buffer_len(bout)); 599 if (buffer_len(berr) > 0) 600 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 601 buffer_len(berr)); 602 603 leave_raw_mode(); 604 605 /* 606 * Free (and clear) the buffer to reduce the amount of data that gets 607 * written to swap. 608 */ 609 buffer_free(bin); 610 buffer_free(bout); 611 buffer_free(berr); 612 613 /* Send the suspend signal to the program itself. */ 614 kill(getpid(), SIGTSTP); 615 616 /* Reset window sizes in case they have changed */ 617 received_window_change_signal = 1; 618 619 /* OK, we have been continued by the user. Reinitialize buffers. */ 620 buffer_init(bin); 621 buffer_init(bout); 622 buffer_init(berr); 623 624 enter_raw_mode(); 625 } 626 627 static void 628 client_process_net_input(fd_set *readset) 629 { 630 int len; 631 char buf[8192]; 632 633 /* 634 * Read input from the server, and add any such data to the buffer of 635 * the packet subsystem. 636 */ 637 if (FD_ISSET(connection_in, readset)) { 638 /* Read as much as possible. */ 639 len = read(connection_in, buf, sizeof(buf)); 640 if (len == 0) { 641 /* 642 * Received EOF. The remote host has closed the 643 * connection. 644 */ 645 snprintf(buf, sizeof buf, 646 "Connection to %.300s closed by remote host.\r\n", 647 host); 648 buffer_append(&stderr_buffer, buf, strlen(buf)); 649 quit_pending = 1; 650 return; 651 } 652 /* 653 * There is a kernel bug on Solaris that causes select to 654 * sometimes wake up even though there is no data available. 655 */ 656 if (len < 0 && (errno == EAGAIN || errno == EINTR)) 657 len = 0; 658 659 if (len < 0) { 660 /* 661 * An error has encountered. Perhaps there is a 662 * network problem. 663 */ 664 snprintf(buf, sizeof buf, 665 "Read from remote host %.300s: %.100s\r\n", 666 host, strerror(errno)); 667 buffer_append(&stderr_buffer, buf, strlen(buf)); 668 quit_pending = 1; 669 return; 670 } 671 packet_process_incoming(buf, len); 672 } 673 } 674 675 static void 676 client_status_confirm(int type, Channel *c, void *ctx) 677 { 678 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 679 char errmsg[256]; 680 int tochan; 681 682 /* XXX supress on mux _client_ quietmode */ 683 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 684 c->ctl_fd != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 685 686 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 687 debug2("%s request accepted on channel %d", 688 cr->request_type, c->self); 689 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 690 if (tochan) { 691 snprintf(errmsg, sizeof(errmsg), 692 "%s request failed\r\n", cr->request_type); 693 } else { 694 snprintf(errmsg, sizeof(errmsg), 695 "%s request failed on channel %d", 696 cr->request_type, c->self); 697 } 698 /* If error occurred on primary session channel, then exit */ 699 if (cr->do_close && c->self == session_ident) 700 fatal("%s", errmsg); 701 /* If error occurred on mux client, append to their stderr */ 702 if (tochan) 703 buffer_append(&c->extended, errmsg, strlen(errmsg)); 704 else 705 error("%s", errmsg); 706 if (cr->do_close) { 707 chan_read_failed(c); 708 chan_write_failed(c); 709 } 710 } 711 xfree(cr); 712 } 713 714 static void 715 client_abandon_status_confirm(Channel *c, void *ctx) 716 { 717 xfree(ctx); 718 } 719 720 static void 721 client_expect_confirm(int id, const char *request, int do_close) 722 { 723 struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); 724 725 cr->request_type = request; 726 cr->do_close = do_close; 727 728 channel_register_status_confirm(id, client_status_confirm, 729 client_abandon_status_confirm, cr); 730 } 731 732 void 733 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 734 { 735 struct global_confirm *gc, *last_gc; 736 737 /* Coalesce identical callbacks */ 738 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 739 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 740 if (++last_gc->ref_count >= INT_MAX) 741 fatal("%s: last_gc->ref_count = %d", 742 __func__, last_gc->ref_count); 743 return; 744 } 745 746 gc = xmalloc(sizeof(*gc)); 747 gc->cb = cb; 748 gc->ctx = ctx; 749 gc->ref_count = 1; 750 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 751 } 752 753 static void 754 process_cmdline(void) 755 { 756 void (*handler)(int); 757 char *s, *cmd, *cancel_host; 758 int delete = 0; 759 int local = 0; 760 u_short cancel_port; 761 Forward fwd; 762 763 bzero(&fwd, sizeof(fwd)); 764 fwd.listen_host = fwd.connect_host = NULL; 765 766 leave_raw_mode(); 767 handler = signal(SIGINT, SIG_IGN); 768 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 769 if (s == NULL) 770 goto out; 771 while (isspace(*s)) 772 s++; 773 if (*s == '-') 774 s++; /* Skip cmdline '-', if any */ 775 if (*s == '\0') 776 goto out; 777 778 if (*s == 'h' || *s == 'H' || *s == '?') { 779 logit("Commands:"); 780 logit(" -L[bind_address:]port:host:hostport " 781 "Request local forward"); 782 logit(" -R[bind_address:]port:host:hostport " 783 "Request remote forward"); 784 logit(" -KR[bind_address:]port " 785 "Cancel remote forward"); 786 if (!options.permit_local_command) 787 goto out; 788 logit(" !args " 789 "Execute local command"); 790 goto out; 791 } 792 793 if (*s == '!' && options.permit_local_command) { 794 s++; 795 ssh_local_cmd(s); 796 goto out; 797 } 798 799 if (*s == 'K') { 800 delete = 1; 801 s++; 802 } 803 if (*s != 'L' && *s != 'R') { 804 logit("Invalid command."); 805 goto out; 806 } 807 if (*s == 'L') 808 local = 1; 809 if (local && delete) { 810 logit("Not supported."); 811 goto out; 812 } 813 if ((!local || delete) && !compat20) { 814 logit("Not supported for SSH protocol version 1."); 815 goto out; 816 } 817 818 while (isspace(*++s)) 819 ; 820 821 if (delete) { 822 cancel_port = 0; 823 cancel_host = hpdelim(&s); /* may be NULL */ 824 if (s != NULL) { 825 cancel_port = a2port(s); 826 cancel_host = cleanhostname(cancel_host); 827 } else { 828 cancel_port = a2port(cancel_host); 829 cancel_host = NULL; 830 } 831 if (cancel_port == 0) { 832 logit("Bad forwarding close port"); 833 goto out; 834 } 835 channel_request_rforward_cancel(cancel_host, cancel_port); 836 } else { 837 if (!parse_forward(&fwd, s)) { 838 logit("Bad forwarding specification."); 839 goto out; 840 } 841 if (local) { 842 if (channel_setup_local_fwd_listener(fwd.listen_host, 843 fwd.listen_port, fwd.connect_host, 844 fwd.connect_port, options.gateway_ports) < 0) { 845 logit("Port forwarding failed."); 846 goto out; 847 } 848 } else { 849 if (channel_request_remote_forwarding(fwd.listen_host, 850 fwd.listen_port, fwd.connect_host, 851 fwd.connect_port) < 0) { 852 logit("Port forwarding failed."); 853 goto out; 854 } 855 } 856 857 logit("Forwarding port."); 858 } 859 860 out: 861 signal(SIGINT, handler); 862 enter_raw_mode(); 863 if (cmd) 864 xfree(cmd); 865 if (fwd.listen_host != NULL) 866 xfree(fwd.listen_host); 867 if (fwd.connect_host != NULL) 868 xfree(fwd.connect_host); 869 } 870 871 /* 872 * Process the characters one by one, call with c==NULL for proto1 case. 873 */ 874 static int 875 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 876 char *buf, int len) 877 { 878 char string[1024]; 879 pid_t pid; 880 int bytes = 0; 881 u_int i; 882 u_char ch; 883 char *s; 884 int *escape_pendingp, escape_char; 885 struct escape_filter_ctx *efc; 886 887 if (c == NULL) { 888 escape_pendingp = &escape_pending1; 889 escape_char = escape_char1; 890 } else { 891 if (c->filter_ctx == NULL) 892 return 0; 893 efc = (struct escape_filter_ctx *)c->filter_ctx; 894 escape_pendingp = &efc->escape_pending; 895 escape_char = efc->escape_char; 896 } 897 898 if (len <= 0) 899 return (0); 900 901 for (i = 0; i < (u_int)len; i++) { 902 /* Get one character at a time. */ 903 ch = buf[i]; 904 905 if (*escape_pendingp) { 906 /* We have previously seen an escape character. */ 907 /* Clear the flag now. */ 908 *escape_pendingp = 0; 909 910 /* Process the escaped character. */ 911 switch (ch) { 912 case '.': 913 /* Terminate the connection. */ 914 snprintf(string, sizeof string, "%c.\r\n", 915 escape_char); 916 buffer_append(berr, string, strlen(string)); 917 918 if (c && c->ctl_fd != -1) { 919 chan_read_failed(c); 920 chan_write_failed(c); 921 return 0; 922 } else 923 quit_pending = 1; 924 return -1; 925 926 case 'Z' - 64: 927 /* XXX support this for mux clients */ 928 if (c && c->ctl_fd != -1) { 929 noescape: 930 snprintf(string, sizeof string, 931 "%c%c escape not available to " 932 "multiplexed sessions\r\n", 933 escape_char, ch); 934 buffer_append(berr, string, 935 strlen(string)); 936 continue; 937 } 938 /* Suspend the program. Inform the user */ 939 snprintf(string, sizeof string, 940 "%c^Z [suspend ssh]\r\n", escape_char); 941 buffer_append(berr, string, strlen(string)); 942 943 /* Restore terminal modes and suspend. */ 944 client_suspend_self(bin, bout, berr); 945 946 /* We have been continued. */ 947 continue; 948 949 case 'B': 950 if (compat20) { 951 snprintf(string, sizeof string, 952 "%cB\r\n", escape_char); 953 buffer_append(berr, string, 954 strlen(string)); 955 channel_request_start(session_ident, 956 "break", 0); 957 packet_put_int(1000); 958 packet_send(); 959 } 960 continue; 961 962 case 'R': 963 if (compat20) { 964 if (datafellows & SSH_BUG_NOREKEY) 965 logit("Server does not " 966 "support re-keying"); 967 else 968 need_rekeying = 1; 969 } 970 continue; 971 972 case '&': 973 if (c && c->ctl_fd != -1) 974 goto noescape; 975 /* 976 * Detach the program (continue to serve 977 * connections, but put in background and no 978 * more new connections). 979 */ 980 /* Restore tty modes. */ 981 leave_raw_mode(); 982 983 /* Stop listening for new connections. */ 984 channel_stop_listening(); 985 986 snprintf(string, sizeof string, 987 "%c& [backgrounded]\n", escape_char); 988 buffer_append(berr, string, strlen(string)); 989 990 /* Fork into background. */ 991 pid = fork(); 992 if (pid < 0) { 993 error("fork: %.100s", strerror(errno)); 994 continue; 995 } 996 if (pid != 0) { /* This is the parent. */ 997 /* The parent just exits. */ 998 exit(0); 999 } 1000 /* The child continues serving connections. */ 1001 if (compat20) { 1002 buffer_append(bin, "\004", 1); 1003 /* fake EOF on stdin */ 1004 return -1; 1005 } else if (!stdin_eof) { 1006 /* 1007 * Sending SSH_CMSG_EOF alone does not 1008 * always appear to be enough. So we 1009 * try to send an EOF character first. 1010 */ 1011 packet_start(SSH_CMSG_STDIN_DATA); 1012 packet_put_string("\004", 1); 1013 packet_send(); 1014 /* Close stdin. */ 1015 stdin_eof = 1; 1016 if (buffer_len(bin) == 0) { 1017 packet_start(SSH_CMSG_EOF); 1018 packet_send(); 1019 } 1020 } 1021 continue; 1022 1023 case '?': 1024 if (c && c->ctl_fd != -1) { 1025 snprintf(string, sizeof string, 1026 "%c?\r\n\ 1027 Supported escape sequences:\r\n\ 1028 %c. - terminate session\r\n\ 1029 %cB - send a BREAK to the remote system\r\n\ 1030 %cC - open a command line\r\n\ 1031 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1032 %c# - list forwarded connections\r\n\ 1033 %c? - this message\r\n\ 1034 %c%c - send the escape character by typing it twice\r\n\ 1035 (Note that escapes are only recognized immediately after newline.)\r\n", 1036 escape_char, escape_char, 1037 escape_char, escape_char, 1038 escape_char, escape_char, 1039 escape_char, escape_char, 1040 escape_char); 1041 } else { 1042 snprintf(string, sizeof string, 1043 "%c?\r\n\ 1044 Supported escape sequences:\r\n\ 1045 %c. - terminate connection (and any multiplexed sessions)\r\n\ 1046 %cB - send a BREAK to the remote system\r\n\ 1047 %cC - open a command line\r\n\ 1048 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1049 %c^Z - suspend ssh\r\n\ 1050 %c# - list forwarded connections\r\n\ 1051 %c& - background ssh (when waiting for connections to terminate)\r\n\ 1052 %c? - this message\r\n\ 1053 %c%c - send the escape character by typing it twice\r\n\ 1054 (Note that escapes are only recognized immediately after newline.)\r\n", 1055 escape_char, escape_char, 1056 escape_char, escape_char, 1057 escape_char, escape_char, 1058 escape_char, escape_char, 1059 escape_char, escape_char, 1060 escape_char); 1061 } 1062 buffer_append(berr, string, strlen(string)); 1063 continue; 1064 1065 case '#': 1066 snprintf(string, sizeof string, "%c#\r\n", 1067 escape_char); 1068 buffer_append(berr, string, strlen(string)); 1069 s = channel_open_message(); 1070 buffer_append(berr, s, strlen(s)); 1071 xfree(s); 1072 continue; 1073 1074 case 'C': 1075 process_cmdline(); 1076 continue; 1077 1078 default: 1079 if (ch != escape_char) { 1080 buffer_put_char(bin, escape_char); 1081 bytes++; 1082 } 1083 /* Escaped characters fall through here */ 1084 break; 1085 } 1086 } else { 1087 /* 1088 * The previous character was not an escape char. 1089 * Check if this is an escape. 1090 */ 1091 if (last_was_cr && ch == escape_char) { 1092 /* 1093 * It is. Set the flag and continue to 1094 * next character. 1095 */ 1096 *escape_pendingp = 1; 1097 continue; 1098 } 1099 } 1100 1101 /* 1102 * Normal character. Record whether it was a newline, 1103 * and append it to the buffer. 1104 */ 1105 last_was_cr = (ch == '\r' || ch == '\n'); 1106 buffer_put_char(bin, ch); 1107 bytes++; 1108 } 1109 return bytes; 1110 } 1111 1112 static void 1113 client_process_input(fd_set *readset) 1114 { 1115 int len; 1116 char buf[8192]; 1117 1118 /* Read input from stdin. */ 1119 if (FD_ISSET(fileno(stdin), readset)) { 1120 /* Read as much as possible. */ 1121 len = read(fileno(stdin), buf, sizeof(buf)); 1122 if (len < 0 && (errno == EAGAIN || errno == EINTR)) 1123 return; /* we'll try again later */ 1124 if (len <= 0) { 1125 /* 1126 * Received EOF or error. They are treated 1127 * similarly, except that an error message is printed 1128 * if it was an error condition. 1129 */ 1130 if (len < 0) { 1131 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1132 strerror(errno)); 1133 buffer_append(&stderr_buffer, buf, strlen(buf)); 1134 } 1135 /* Mark that we have seen EOF. */ 1136 stdin_eof = 1; 1137 /* 1138 * Send an EOF message to the server unless there is 1139 * data in the buffer. If there is data in the 1140 * buffer, no message will be sent now. Code 1141 * elsewhere will send the EOF when the buffer 1142 * becomes empty if stdin_eof is set. 1143 */ 1144 if (buffer_len(&stdin_buffer) == 0) { 1145 packet_start(SSH_CMSG_EOF); 1146 packet_send(); 1147 } 1148 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1149 /* 1150 * Normal successful read, and no escape character. 1151 * Just append the data to buffer. 1152 */ 1153 buffer_append(&stdin_buffer, buf, len); 1154 } else { 1155 /* 1156 * Normal, successful read. But we have an escape 1157 * character and have to process the characters one 1158 * by one. 1159 */ 1160 if (process_escapes(NULL, &stdin_buffer, 1161 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1162 return; 1163 } 1164 } 1165 } 1166 1167 static void 1168 client_process_output(fd_set *writeset) 1169 { 1170 int len; 1171 char buf[100]; 1172 1173 /* Write buffered output to stdout. */ 1174 if (FD_ISSET(fileno(stdout), writeset)) { 1175 /* Write as much data as possible. */ 1176 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1177 buffer_len(&stdout_buffer)); 1178 if (len <= 0) { 1179 if (errno == EINTR || errno == EAGAIN) 1180 len = 0; 1181 else { 1182 /* 1183 * An error or EOF was encountered. Put an 1184 * error message to stderr buffer. 1185 */ 1186 snprintf(buf, sizeof buf, 1187 "write stdout: %.50s\r\n", strerror(errno)); 1188 buffer_append(&stderr_buffer, buf, strlen(buf)); 1189 quit_pending = 1; 1190 return; 1191 } 1192 } 1193 /* Consume printed data from the buffer. */ 1194 buffer_consume(&stdout_buffer, len); 1195 } 1196 /* Write buffered output to stderr. */ 1197 if (FD_ISSET(fileno(stderr), writeset)) { 1198 /* Write as much data as possible. */ 1199 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1200 buffer_len(&stderr_buffer)); 1201 if (len <= 0) { 1202 if (errno == EINTR || errno == EAGAIN) 1203 len = 0; 1204 else { 1205 /* 1206 * EOF or error, but can't even print 1207 * error message. 1208 */ 1209 quit_pending = 1; 1210 return; 1211 } 1212 } 1213 /* Consume printed characters from the buffer. */ 1214 buffer_consume(&stderr_buffer, len); 1215 } 1216 } 1217 1218 /* 1219 * Get packets from the connection input buffer, and process them as long as 1220 * there are packets available. 1221 * 1222 * Any unknown packets received during the actual 1223 * session cause the session to terminate. This is 1224 * intended to make debugging easier since no 1225 * confirmations are sent. Any compatible protocol 1226 * extensions must be negotiated during the 1227 * preparatory phase. 1228 */ 1229 1230 static void 1231 client_process_buffered_input_packets(void) 1232 { 1233 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1234 compat20 ? xxx_kex : NULL); 1235 } 1236 1237 /* scan buf[] for '~' before sending data to the peer */ 1238 1239 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1240 void * 1241 client_new_escape_filter_ctx(int escape_char) 1242 { 1243 struct escape_filter_ctx *ret; 1244 1245 ret = xmalloc(sizeof(*ret)); 1246 ret->escape_pending = 0; 1247 ret->escape_char = escape_char; 1248 return (void *)ret; 1249 } 1250 1251 /* Free the escape filter context on channel free */ 1252 void 1253 client_filter_cleanup(int cid, void *ctx) 1254 { 1255 xfree(ctx); 1256 } 1257 1258 int 1259 client_simple_escape_filter(Channel *c, char *buf, int len) 1260 { 1261 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1262 return 0; 1263 1264 return process_escapes(c, &c->input, &c->output, &c->extended, 1265 buf, len); 1266 } 1267 1268 static void 1269 client_channel_closed(int id, void *arg) 1270 { 1271 channel_cancel_cleanup(id); 1272 session_closed = 1; 1273 leave_raw_mode(); 1274 } 1275 1276 /* 1277 * Implements the interactive session with the server. This is called after 1278 * the user has been authenticated, and a command has been started on the 1279 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1280 * used as an escape character for terminating or suspending the session. 1281 */ 1282 1283 int 1284 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1285 { 1286 fd_set *readset = NULL, *writeset = NULL; 1287 double start_time, total_time; 1288 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1289 u_int64_t ibytes, obytes; 1290 u_int nalloc = 0; 1291 char buf[100]; 1292 1293 debug("Entering interactive session."); 1294 1295 start_time = get_current_time(); 1296 1297 /* Initialize variables. */ 1298 escape_pending1 = 0; 1299 last_was_cr = 1; 1300 exit_status = -1; 1301 stdin_eof = 0; 1302 buffer_high = 64 * 1024; 1303 connection_in = packet_get_connection_in(); 1304 connection_out = packet_get_connection_out(); 1305 max_fd = MAX(connection_in, connection_out); 1306 if (muxserver_sock != -1) 1307 max_fd = MAX(max_fd, muxserver_sock); 1308 1309 if (!compat20) { 1310 /* enable nonblocking unless tty */ 1311 if (!isatty(fileno(stdin))) 1312 set_nonblock(fileno(stdin)); 1313 if (!isatty(fileno(stdout))) 1314 set_nonblock(fileno(stdout)); 1315 if (!isatty(fileno(stderr))) 1316 set_nonblock(fileno(stderr)); 1317 max_fd = MAX(max_fd, fileno(stdin)); 1318 max_fd = MAX(max_fd, fileno(stdout)); 1319 max_fd = MAX(max_fd, fileno(stderr)); 1320 } 1321 quit_pending = 0; 1322 escape_char1 = escape_char_arg; 1323 1324 /* Initialize buffers. */ 1325 buffer_init(&stdin_buffer); 1326 buffer_init(&stdout_buffer); 1327 buffer_init(&stderr_buffer); 1328 1329 client_init_dispatch(); 1330 1331 /* 1332 * Set signal handlers, (e.g. to restore non-blocking mode) 1333 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1334 */ 1335 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1336 signal(SIGHUP, signal_handler); 1337 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1338 signal(SIGINT, signal_handler); 1339 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1340 signal(SIGQUIT, signal_handler); 1341 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1342 signal(SIGTERM, signal_handler); 1343 signal(SIGWINCH, window_change_handler); 1344 1345 if (have_pty) 1346 enter_raw_mode(); 1347 1348 if (compat20) { 1349 session_ident = ssh2_chan_id; 1350 if (escape_char_arg != SSH_ESCAPECHAR_NONE) 1351 channel_register_filter(session_ident, 1352 client_simple_escape_filter, NULL, 1353 client_filter_cleanup, 1354 client_new_escape_filter_ctx(escape_char_arg)); 1355 if (session_ident != -1) 1356 channel_register_cleanup(session_ident, 1357 client_channel_closed, 0); 1358 } else { 1359 /* Check if we should immediately send eof on stdin. */ 1360 client_check_initial_eof_on_stdin(); 1361 } 1362 1363 /* Main loop of the client for the interactive session mode. */ 1364 while (!quit_pending) { 1365 1366 /* Process buffered packets sent by the server. */ 1367 client_process_buffered_input_packets(); 1368 1369 if (compat20 && session_closed && !channel_still_open()) 1370 break; 1371 1372 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1373 1374 if (rekeying) { 1375 debug("rekeying in progress"); 1376 } else { 1377 /* 1378 * Make packets of buffered stdin data, and buffer 1379 * them for sending to the server. 1380 */ 1381 if (!compat20) 1382 client_make_packets_from_stdin_data(); 1383 1384 /* 1385 * Make packets from buffered channel data, and 1386 * enqueue them for sending to the server. 1387 */ 1388 if (packet_not_very_much_data_to_write()) 1389 channel_output_poll(); 1390 1391 /* 1392 * Check if the window size has changed, and buffer a 1393 * message about it to the server if so. 1394 */ 1395 client_check_window_change(); 1396 1397 if (quit_pending) 1398 break; 1399 } 1400 /* 1401 * Wait until we have something to do (something becomes 1402 * available on one of the descriptors). 1403 */ 1404 max_fd2 = max_fd; 1405 client_wait_until_can_do_something(&readset, &writeset, 1406 &max_fd2, &nalloc, rekeying); 1407 1408 if (quit_pending) 1409 break; 1410 1411 /* Do channel operations unless rekeying in progress. */ 1412 if (!rekeying) { 1413 channel_after_select(readset, writeset); 1414 if (need_rekeying || packet_need_rekeying()) { 1415 debug("need rekeying"); 1416 xxx_kex->done = 0; 1417 kex_send_kexinit(xxx_kex); 1418 need_rekeying = 0; 1419 } 1420 } 1421 1422 /* Buffer input from the connection. */ 1423 client_process_net_input(readset); 1424 1425 /* Accept control connections. */ 1426 if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) { 1427 if (muxserver_accept_control()) 1428 quit_pending = 1; 1429 } 1430 1431 if (quit_pending) 1432 break; 1433 1434 if (!compat20) { 1435 /* Buffer data from stdin */ 1436 client_process_input(readset); 1437 /* 1438 * Process output to stdout and stderr. Output to 1439 * the connection is processed elsewhere (above). 1440 */ 1441 client_process_output(writeset); 1442 } 1443 1444 /* 1445 * Send as much buffered packet data as possible to the 1446 * sender. 1447 */ 1448 if (FD_ISSET(connection_out, writeset)) 1449 packet_write_poll(); 1450 } 1451 if (readset) 1452 xfree(readset); 1453 if (writeset) 1454 xfree(writeset); 1455 1456 /* Terminate the session. */ 1457 1458 /* Stop watching for window change. */ 1459 signal(SIGWINCH, SIG_DFL); 1460 1461 channel_free_all(); 1462 1463 if (have_pty) 1464 leave_raw_mode(); 1465 1466 /* restore blocking io */ 1467 if (!isatty(fileno(stdin))) 1468 unset_nonblock(fileno(stdin)); 1469 if (!isatty(fileno(stdout))) 1470 unset_nonblock(fileno(stdout)); 1471 if (!isatty(fileno(stderr))) 1472 unset_nonblock(fileno(stderr)); 1473 1474 /* 1475 * If there was no shell or command requested, there will be no remote 1476 * exit status to be returned. In that case, clear error code if the 1477 * connection was deliberately terminated at this end. 1478 */ 1479 if (no_shell_flag && received_signal == SIGTERM) { 1480 received_signal = 0; 1481 exit_status = 0; 1482 } 1483 1484 if (received_signal) 1485 fatal("Killed by signal %d.", (int) received_signal); 1486 1487 /* 1488 * In interactive mode (with pseudo tty) display a message indicating 1489 * that the connection has been closed. 1490 */ 1491 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1492 snprintf(buf, sizeof buf, 1493 "Connection to %.64s closed.\r\n", host); 1494 buffer_append(&stderr_buffer, buf, strlen(buf)); 1495 } 1496 1497 /* Output any buffered data for stdout. */ 1498 while (buffer_len(&stdout_buffer) > 0) { 1499 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1500 buffer_len(&stdout_buffer)); 1501 if (len <= 0) { 1502 error("Write failed flushing stdout buffer."); 1503 break; 1504 } 1505 buffer_consume(&stdout_buffer, len); 1506 } 1507 1508 /* Output any buffered data for stderr. */ 1509 while (buffer_len(&stderr_buffer) > 0) { 1510 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1511 buffer_len(&stderr_buffer)); 1512 if (len <= 0) { 1513 error("Write failed flushing stderr buffer."); 1514 break; 1515 } 1516 buffer_consume(&stderr_buffer, len); 1517 } 1518 1519 /* Clear and free any buffers. */ 1520 memset(buf, 0, sizeof(buf)); 1521 buffer_free(&stdin_buffer); 1522 buffer_free(&stdout_buffer); 1523 buffer_free(&stderr_buffer); 1524 1525 /* Report bytes transferred, and transfer rates. */ 1526 total_time = get_current_time() - start_time; 1527 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1528 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1529 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1530 obytes, ibytes, total_time); 1531 if (total_time > 0) 1532 verbose("Bytes per second: sent %.1f, received %.1f", 1533 obytes / total_time, ibytes / total_time); 1534 /* Return the exit status of the program. */ 1535 debug("Exit status %d", exit_status); 1536 return exit_status; 1537 } 1538 1539 /*********/ 1540 1541 static void 1542 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1543 { 1544 u_int data_len; 1545 char *data = packet_get_string(&data_len); 1546 packet_check_eom(); 1547 buffer_append(&stdout_buffer, data, data_len); 1548 memset(data, 0, data_len); 1549 xfree(data); 1550 } 1551 static void 1552 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1553 { 1554 u_int data_len; 1555 char *data = packet_get_string(&data_len); 1556 packet_check_eom(); 1557 buffer_append(&stderr_buffer, data, data_len); 1558 memset(data, 0, data_len); 1559 xfree(data); 1560 } 1561 static void 1562 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1563 { 1564 exit_status = packet_get_int(); 1565 packet_check_eom(); 1566 /* Acknowledge the exit. */ 1567 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1568 packet_send(); 1569 /* 1570 * Must wait for packet to be sent since we are 1571 * exiting the loop. 1572 */ 1573 packet_write_wait(); 1574 /* Flag that we want to exit. */ 1575 quit_pending = 1; 1576 } 1577 static void 1578 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1579 { 1580 Channel *c = NULL; 1581 int remote_id, sock; 1582 1583 /* Read the remote channel number from the message. */ 1584 remote_id = packet_get_int(); 1585 packet_check_eom(); 1586 1587 /* 1588 * Get a connection to the local authentication agent (this may again 1589 * get forwarded). 1590 */ 1591 sock = ssh_get_authentication_socket(); 1592 1593 /* 1594 * If we could not connect the agent, send an error message back to 1595 * the server. This should never happen unless the agent dies, 1596 * because authentication forwarding is only enabled if we have an 1597 * agent. 1598 */ 1599 if (sock >= 0) { 1600 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1601 -1, 0, 0, 0, "authentication agent connection", 1); 1602 c->remote_id = remote_id; 1603 c->force_drain = 1; 1604 } 1605 if (c == NULL) { 1606 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1607 packet_put_int(remote_id); 1608 } else { 1609 /* Send a confirmation to the remote host. */ 1610 debug("Forwarding authentication connection."); 1611 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1612 packet_put_int(remote_id); 1613 packet_put_int(c->self); 1614 } 1615 packet_send(); 1616 } 1617 1618 static Channel * 1619 client_request_forwarded_tcpip(const char *request_type, int rchan) 1620 { 1621 Channel *c = NULL; 1622 char *listen_address, *originator_address; 1623 int listen_port, originator_port; 1624 1625 /* Get rest of the packet */ 1626 listen_address = packet_get_string(NULL); 1627 listen_port = packet_get_int(); 1628 originator_address = packet_get_string(NULL); 1629 originator_port = packet_get_int(); 1630 packet_check_eom(); 1631 1632 debug("client_request_forwarded_tcpip: listen %s port %d, " 1633 "originator %s port %d", listen_address, listen_port, 1634 originator_address, originator_port); 1635 1636 c = channel_connect_by_listen_address(listen_port, 1637 "forwarded-tcpip", originator_address); 1638 1639 xfree(originator_address); 1640 xfree(listen_address); 1641 return c; 1642 } 1643 1644 static Channel * 1645 client_request_x11(const char *request_type, int rchan) 1646 { 1647 Channel *c = NULL; 1648 char *originator; 1649 int originator_port; 1650 int sock; 1651 1652 if (!options.forward_x11) { 1653 error("Warning: ssh server tried X11 forwarding."); 1654 error("Warning: this is probably a break-in attempt by a " 1655 "malicious server."); 1656 return NULL; 1657 } 1658 originator = packet_get_string(NULL); 1659 if (datafellows & SSH_BUG_X11FWD) { 1660 debug2("buggy server: x11 request w/o originator_port"); 1661 originator_port = 0; 1662 } else { 1663 originator_port = packet_get_int(); 1664 } 1665 packet_check_eom(); 1666 /* XXX check permission */ 1667 debug("client_request_x11: request from %s %d", originator, 1668 originator_port); 1669 xfree(originator); 1670 sock = x11_connect_display(); 1671 if (sock < 0) 1672 return NULL; 1673 c = channel_new("x11", 1674 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1675 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1676 c->force_drain = 1; 1677 return c; 1678 } 1679 1680 static Channel * 1681 client_request_agent(const char *request_type, int rchan) 1682 { 1683 Channel *c = NULL; 1684 int sock; 1685 1686 if (!options.forward_agent) { 1687 error("Warning: ssh server tried agent forwarding."); 1688 error("Warning: this is probably a break-in attempt by a " 1689 "malicious server."); 1690 return NULL; 1691 } 1692 sock = ssh_get_authentication_socket(); 1693 if (sock < 0) 1694 return NULL; 1695 c = channel_new("authentication agent connection", 1696 SSH_CHANNEL_OPEN, sock, sock, -1, 1697 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1698 "authentication agent connection", 1); 1699 c->force_drain = 1; 1700 return c; 1701 } 1702 1703 int 1704 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1705 { 1706 Channel *c; 1707 int fd; 1708 1709 if (tun_mode == SSH_TUNMODE_NO) 1710 return 0; 1711 1712 if (!compat20) { 1713 error("Tunnel forwarding is not support for protocol 1"); 1714 return -1; 1715 } 1716 1717 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1718 1719 /* Open local tunnel device */ 1720 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1721 error("Tunnel device open failed."); 1722 return -1; 1723 } 1724 1725 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1726 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1727 c->datagram = 1; 1728 1729 packet_start(SSH2_MSG_CHANNEL_OPEN); 1730 packet_put_cstring("tun@openssh.com"); 1731 packet_put_int(c->self); 1732 packet_put_int(c->local_window_max); 1733 packet_put_int(c->local_maxpacket); 1734 packet_put_int(tun_mode); 1735 packet_put_int(remote_tun); 1736 packet_send(); 1737 1738 return 0; 1739 } 1740 1741 /* XXXX move to generic input handler */ 1742 static void 1743 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1744 { 1745 Channel *c = NULL; 1746 char *ctype; 1747 int rchan; 1748 u_int rmaxpack, rwindow, len; 1749 1750 ctype = packet_get_string(&len); 1751 rchan = packet_get_int(); 1752 rwindow = packet_get_int(); 1753 rmaxpack = packet_get_int(); 1754 1755 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1756 ctype, rchan, rwindow, rmaxpack); 1757 1758 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1759 c = client_request_forwarded_tcpip(ctype, rchan); 1760 } else if (strcmp(ctype, "x11") == 0) { 1761 c = client_request_x11(ctype, rchan); 1762 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1763 c = client_request_agent(ctype, rchan); 1764 } 1765 /* XXX duplicate : */ 1766 if (c != NULL) { 1767 debug("confirm %s", ctype); 1768 c->remote_id = rchan; 1769 c->remote_window = rwindow; 1770 c->remote_maxpacket = rmaxpack; 1771 if (c->type != SSH_CHANNEL_CONNECTING) { 1772 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 1773 packet_put_int(c->remote_id); 1774 packet_put_int(c->self); 1775 packet_put_int(c->local_window); 1776 packet_put_int(c->local_maxpacket); 1777 packet_send(); 1778 } 1779 } else { 1780 debug("failure %s", ctype); 1781 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 1782 packet_put_int(rchan); 1783 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 1784 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 1785 packet_put_cstring("open failed"); 1786 packet_put_cstring(""); 1787 } 1788 packet_send(); 1789 } 1790 xfree(ctype); 1791 } 1792 static void 1793 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 1794 { 1795 Channel *c = NULL; 1796 int exitval, id, reply, success = 0; 1797 char *rtype; 1798 1799 id = packet_get_int(); 1800 rtype = packet_get_string(NULL); 1801 reply = packet_get_char(); 1802 1803 debug("client_input_channel_req: channel %d rtype %s reply %d", 1804 id, rtype, reply); 1805 1806 if (id == -1) { 1807 error("client_input_channel_req: request for channel -1"); 1808 } else if ((c = channel_lookup(id)) == NULL) { 1809 error("client_input_channel_req: channel %d: " 1810 "unknown channel", id); 1811 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1812 packet_check_eom(); 1813 chan_rcvd_eow(c); 1814 } else if (strcmp(rtype, "exit-status") == 0) { 1815 exitval = packet_get_int(); 1816 if (id == session_ident) { 1817 success = 1; 1818 exit_status = exitval; 1819 } else if (c->ctl_fd == -1) { 1820 error("client_input_channel_req: unexpected channel %d", 1821 session_ident); 1822 } else { 1823 atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval)); 1824 success = 1; 1825 } 1826 packet_check_eom(); 1827 } 1828 if (reply) { 1829 packet_start(success ? 1830 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 1831 packet_put_int(id); 1832 packet_send(); 1833 } 1834 xfree(rtype); 1835 } 1836 static void 1837 client_input_global_request(int type, u_int32_t seq, void *ctxt) 1838 { 1839 char *rtype; 1840 int want_reply; 1841 int success = 0; 1842 1843 rtype = packet_get_string(NULL); 1844 want_reply = packet_get_char(); 1845 debug("client_input_global_request: rtype %s want_reply %d", 1846 rtype, want_reply); 1847 if (want_reply) { 1848 packet_start(success ? 1849 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 1850 packet_send(); 1851 packet_write_wait(); 1852 } 1853 xfree(rtype); 1854 } 1855 1856 void 1857 client_session2_setup(int id, int want_tty, int want_subsystem, 1858 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 1859 { 1860 int len; 1861 Channel *c = NULL; 1862 1863 debug2("%s: id %d", __func__, id); 1864 1865 if ((c = channel_lookup(id)) == NULL) 1866 fatal("client_session2_setup: channel %d: unknown channel", id); 1867 1868 if (want_tty) { 1869 struct winsize ws; 1870 1871 /* Store window size in the packet. */ 1872 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 1873 memset(&ws, 0, sizeof(ws)); 1874 1875 channel_request_start(id, "pty-req", 1); 1876 client_expect_confirm(id, "PTY allocation", 0); 1877 packet_put_cstring(term != NULL ? term : ""); 1878 packet_put_int((u_int)ws.ws_col); 1879 packet_put_int((u_int)ws.ws_row); 1880 packet_put_int((u_int)ws.ws_xpixel); 1881 packet_put_int((u_int)ws.ws_ypixel); 1882 if (tiop == NULL) 1883 tiop = get_saved_tio(); 1884 tty_make_modes(-1, tiop); 1885 packet_send(); 1886 /* XXX wait for reply */ 1887 c->client_tty = 1; 1888 } 1889 1890 /* Transfer any environment variables from client to server */ 1891 if (options.num_send_env != 0 && env != NULL) { 1892 int i, j, matched; 1893 char *name, *val; 1894 1895 debug("Sending environment."); 1896 for (i = 0; env[i] != NULL; i++) { 1897 /* Split */ 1898 name = xstrdup(env[i]); 1899 if ((val = strchr(name, '=')) == NULL) { 1900 xfree(name); 1901 continue; 1902 } 1903 *val++ = '\0'; 1904 1905 matched = 0; 1906 for (j = 0; j < options.num_send_env; j++) { 1907 if (match_pattern(name, options.send_env[j])) { 1908 matched = 1; 1909 break; 1910 } 1911 } 1912 if (!matched) { 1913 debug3("Ignored env %s", name); 1914 xfree(name); 1915 continue; 1916 } 1917 1918 debug("Sending env %s = %s", name, val); 1919 channel_request_start(id, "env", 0); 1920 packet_put_cstring(name); 1921 packet_put_cstring(val); 1922 packet_send(); 1923 xfree(name); 1924 } 1925 } 1926 1927 len = buffer_len(cmd); 1928 if (len > 0) { 1929 if (len > 900) 1930 len = 900; 1931 if (want_subsystem) { 1932 debug("Sending subsystem: %.*s", 1933 len, (u_char*)buffer_ptr(cmd)); 1934 channel_request_start(id, "subsystem", 1); 1935 client_expect_confirm(id, "subsystem", 1); 1936 } else { 1937 debug("Sending command: %.*s", 1938 len, (u_char*)buffer_ptr(cmd)); 1939 channel_request_start(id, "exec", 1); 1940 client_expect_confirm(id, "exec", 1); 1941 } 1942 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 1943 packet_send(); 1944 } else { 1945 channel_request_start(id, "shell", 1); 1946 client_expect_confirm(id, "shell", 1); 1947 packet_send(); 1948 } 1949 } 1950 1951 static void 1952 client_init_dispatch_20(void) 1953 { 1954 dispatch_init(&dispatch_protocol_error); 1955 1956 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 1957 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 1958 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 1959 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 1960 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 1961 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 1962 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 1963 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 1964 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 1965 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 1966 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 1967 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 1968 1969 /* rekeying */ 1970 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 1971 1972 /* global request reply messages */ 1973 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 1974 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 1975 } 1976 1977 static void 1978 client_init_dispatch_13(void) 1979 { 1980 dispatch_init(NULL); 1981 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 1982 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 1983 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 1984 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 1985 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 1986 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 1987 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 1988 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 1989 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 1990 1991 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 1992 &client_input_agent_open : &deny_input_open); 1993 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 1994 &x11_input_open : &deny_input_open); 1995 } 1996 1997 static void 1998 client_init_dispatch_15(void) 1999 { 2000 client_init_dispatch_13(); 2001 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2002 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2003 } 2004 2005 static void 2006 client_init_dispatch(void) 2007 { 2008 if (compat20) 2009 client_init_dispatch_20(); 2010 else if (compat13) 2011 client_init_dispatch_13(); 2012 else 2013 client_init_dispatch_15(); 2014 } 2015 2016 /* client specific fatal cleanup */ 2017 void 2018 cleanup_exit(int i) 2019 { 2020 leave_raw_mode(); 2021 leave_non_blocking(); 2022 if (options.control_path != NULL && muxserver_sock != -1) 2023 unlink(options.control_path); 2024 _exit(i); 2025 } 2026