1 /* $OpenBSD: clientloop.c,v 1.199 2008/06/12 21:06:25 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_long stdin_bytes, stdout_bytes, stderr_bytes; 148 static u_int buffer_high;/* Soft max buffer size. */ 149 static int connection_in; /* Connection to server (input). */ 150 static int connection_out; /* Connection to server (output). */ 151 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 152 static int session_closed = 0; /* In SSH2: login session closed. */ 153 154 static void client_init_dispatch(void); 155 int session_ident = -1; 156 157 /* Track escape per proto2 channel */ 158 struct escape_filter_ctx { 159 int escape_pending; 160 int escape_char; 161 }; 162 163 /* Context for channel confirmation replies */ 164 struct channel_reply_ctx { 165 const char *request_type; 166 int id, do_close; 167 }; 168 169 /* Global request success/failure callbacks */ 170 struct global_confirm { 171 TAILQ_ENTRY(global_confirm) entry; 172 global_confirm_cb *cb; 173 void *ctx; 174 int ref_count; 175 }; 176 TAILQ_HEAD(global_confirms, global_confirm); 177 static struct global_confirms global_confirms = 178 TAILQ_HEAD_INITIALIZER(global_confirms); 179 180 /*XXX*/ 181 extern Kex *xxx_kex; 182 183 void ssh_process_session2_setup(int, int, int, Buffer *); 184 185 /* Restores stdin to blocking mode. */ 186 187 static void 188 leave_non_blocking(void) 189 { 190 if (in_non_blocking_mode) { 191 unset_nonblock(fileno(stdin)); 192 in_non_blocking_mode = 0; 193 } 194 } 195 196 /* Puts stdin terminal in non-blocking mode. */ 197 198 static void 199 enter_non_blocking(void) 200 { 201 in_non_blocking_mode = 1; 202 set_nonblock(fileno(stdin)); 203 } 204 205 /* 206 * Signal handler for the window change signal (SIGWINCH). This just sets a 207 * flag indicating that the window has changed. 208 */ 209 /*ARGSUSED */ 210 static void 211 window_change_handler(int sig) 212 { 213 received_window_change_signal = 1; 214 signal(SIGWINCH, window_change_handler); 215 } 216 217 /* 218 * Signal handler for signals that cause the program to terminate. These 219 * signals must be trapped to restore terminal modes. 220 */ 221 /*ARGSUSED */ 222 static void 223 signal_handler(int sig) 224 { 225 received_signal = sig; 226 quit_pending = 1; 227 } 228 229 /* 230 * Returns current time in seconds from Jan 1, 1970 with the maximum 231 * available resolution. 232 */ 233 234 static double 235 get_current_time(void) 236 { 237 struct timeval tv; 238 gettimeofday(&tv, NULL); 239 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 240 } 241 242 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 243 void 244 client_x11_get_proto(const char *display, const char *xauth_path, 245 u_int trusted, char **_proto, char **_data) 246 { 247 char cmd[1024]; 248 char line[512]; 249 char xdisplay[512]; 250 static char proto[512], data[512]; 251 FILE *f; 252 int got_data = 0, generated = 0, do_unlink = 0, i; 253 char *xauthdir, *xauthfile; 254 struct stat st; 255 256 xauthdir = xauthfile = NULL; 257 *_proto = proto; 258 *_data = data; 259 proto[0] = data[0] = '\0'; 260 261 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 262 debug("No xauth program."); 263 } else { 264 if (display == NULL) { 265 debug("x11_get_proto: DISPLAY not set"); 266 return; 267 } 268 /* 269 * Handle FamilyLocal case where $DISPLAY does 270 * not match an authorization entry. For this we 271 * just try "xauth list unix:displaynum.screennum". 272 * XXX: "localhost" match to determine FamilyLocal 273 * is not perfect. 274 */ 275 if (strncmp(display, "localhost:", 10) == 0) { 276 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 277 display + 10); 278 display = xdisplay; 279 } 280 if (trusted == 0) { 281 xauthdir = xmalloc(MAXPATHLEN); 282 xauthfile = xmalloc(MAXPATHLEN); 283 strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); 284 if (mkdtemp(xauthdir) != NULL) { 285 do_unlink = 1; 286 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", 287 xauthdir); 288 snprintf(cmd, sizeof(cmd), 289 "%s -f %s generate %s " SSH_X11_PROTO 290 " untrusted timeout 1200 2>" _PATH_DEVNULL, 291 xauth_path, xauthfile, display); 292 debug2("x11_get_proto: %s", cmd); 293 if (system(cmd) == 0) 294 generated = 1; 295 } 296 } 297 298 /* 299 * When in untrusted mode, we read the cookie only if it was 300 * successfully generated as an untrusted one in the step 301 * above. 302 */ 303 if (trusted || generated) { 304 snprintf(cmd, sizeof(cmd), 305 "%s %s%s list %s 2>" _PATH_DEVNULL, 306 xauth_path, 307 generated ? "-f " : "" , 308 generated ? xauthfile : "", 309 display); 310 debug2("x11_get_proto: %s", cmd); 311 f = popen(cmd, "r"); 312 if (f && fgets(line, sizeof(line), f) && 313 sscanf(line, "%*s %511s %511s", proto, data) == 2) 314 got_data = 1; 315 if (f) 316 pclose(f); 317 } else 318 error("Warning: untrusted X11 forwarding setup failed: " 319 "xauth key data not generated"); 320 } 321 322 if (do_unlink) { 323 unlink(xauthfile); 324 rmdir(xauthdir); 325 } 326 if (xauthdir) 327 xfree(xauthdir); 328 if (xauthfile) 329 xfree(xauthfile); 330 331 /* 332 * If we didn't get authentication data, just make up some 333 * data. The forwarding code will check the validity of the 334 * response anyway, and substitute this data. The X11 335 * server, however, will ignore this fake data and use 336 * whatever authentication mechanisms it was using otherwise 337 * for the local connection. 338 */ 339 if (!got_data) { 340 u_int32_t rnd = 0; 341 342 logit("Warning: No xauth data; " 343 "using fake authentication data for X11 forwarding."); 344 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 345 for (i = 0; i < 16; i++) { 346 if (i % 4 == 0) 347 rnd = arc4random(); 348 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 349 rnd & 0xff); 350 rnd >>= 8; 351 } 352 } 353 } 354 355 /* 356 * This is called when the interactive is entered. This checks if there is 357 * an EOF coming on stdin. We must check this explicitly, as select() does 358 * not appear to wake up when redirecting from /dev/null. 359 */ 360 361 static void 362 client_check_initial_eof_on_stdin(void) 363 { 364 int len; 365 char buf[1]; 366 367 /* 368 * If standard input is to be "redirected from /dev/null", we simply 369 * mark that we have seen an EOF and send an EOF message to the 370 * server. Otherwise, we try to read a single character; it appears 371 * that for some files, such /dev/null, select() never wakes up for 372 * read for this descriptor, which means that we never get EOF. This 373 * way we will get the EOF if stdin comes from /dev/null or similar. 374 */ 375 if (stdin_null_flag) { 376 /* Fake EOF on stdin. */ 377 debug("Sending eof."); 378 stdin_eof = 1; 379 packet_start(SSH_CMSG_EOF); 380 packet_send(); 381 } else { 382 enter_non_blocking(); 383 384 /* Check for immediate EOF on stdin. */ 385 len = read(fileno(stdin), buf, 1); 386 if (len == 0) { 387 /* 388 * EOF. Record that we have seen it and send 389 * EOF to server. 390 */ 391 debug("Sending eof."); 392 stdin_eof = 1; 393 packet_start(SSH_CMSG_EOF); 394 packet_send(); 395 } else if (len > 0) { 396 /* 397 * Got data. We must store the data in the buffer, 398 * and also process it as an escape character if 399 * appropriate. 400 */ 401 if ((u_char) buf[0] == escape_char1) 402 escape_pending1 = 1; 403 else 404 buffer_append(&stdin_buffer, buf, 1); 405 } 406 leave_non_blocking(); 407 } 408 } 409 410 411 /* 412 * Make packets from buffered stdin data, and buffer them for sending to the 413 * connection. 414 */ 415 416 static void 417 client_make_packets_from_stdin_data(void) 418 { 419 u_int len; 420 421 /* Send buffered stdin data to the server. */ 422 while (buffer_len(&stdin_buffer) > 0 && 423 packet_not_very_much_data_to_write()) { 424 len = buffer_len(&stdin_buffer); 425 /* Keep the packets at reasonable size. */ 426 if (len > packet_get_maxsize()) 427 len = packet_get_maxsize(); 428 packet_start(SSH_CMSG_STDIN_DATA); 429 packet_put_string(buffer_ptr(&stdin_buffer), len); 430 packet_send(); 431 buffer_consume(&stdin_buffer, len); 432 stdin_bytes += len; 433 /* If we have a pending EOF, send it now. */ 434 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 435 packet_start(SSH_CMSG_EOF); 436 packet_send(); 437 } 438 } 439 } 440 441 /* 442 * Checks if the client window has changed, and sends a packet about it to 443 * the server if so. The actual change is detected elsewhere (by a software 444 * interrupt on Unix); this just checks the flag and sends a message if 445 * appropriate. 446 */ 447 448 static void 449 client_check_window_change(void) 450 { 451 struct winsize ws; 452 453 if (! received_window_change_signal) 454 return; 455 /** XXX race */ 456 received_window_change_signal = 0; 457 458 debug2("client_check_window_change: changed"); 459 460 if (compat20) { 461 channel_send_window_changes(); 462 } else { 463 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 464 return; 465 packet_start(SSH_CMSG_WINDOW_SIZE); 466 packet_put_int((u_int)ws.ws_row); 467 packet_put_int((u_int)ws.ws_col); 468 packet_put_int((u_int)ws.ws_xpixel); 469 packet_put_int((u_int)ws.ws_ypixel); 470 packet_send(); 471 } 472 } 473 474 static void 475 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 476 { 477 struct global_confirm *gc; 478 479 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 480 return; 481 if (gc->cb != NULL) 482 gc->cb(type, seq, gc->ctx); 483 if (--gc->ref_count <= 0) { 484 TAILQ_REMOVE(&global_confirms, gc, entry); 485 bzero(gc, sizeof(*gc)); 486 xfree(gc); 487 } 488 489 keep_alive_timeouts = 0; 490 } 491 492 static void 493 server_alive_check(void) 494 { 495 if (++keep_alive_timeouts > options.server_alive_count_max) { 496 logit("Timeout, server not responding."); 497 cleanup_exit(255); 498 } 499 packet_start(SSH2_MSG_GLOBAL_REQUEST); 500 packet_put_cstring("keepalive@openssh.com"); 501 packet_put_char(1); /* boolean: want reply */ 502 packet_send(); 503 /* Insert an empty placeholder to maintain ordering */ 504 client_register_global_confirm(NULL, NULL); 505 } 506 507 /* 508 * Waits until the client can do something (some data becomes available on 509 * one of the file descriptors). 510 */ 511 static void 512 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 513 int *maxfdp, u_int *nallocp, int rekeying) 514 { 515 struct timeval tv, *tvp; 516 int ret; 517 518 /* Add any selections by the channel mechanism. */ 519 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); 520 521 if (!compat20) { 522 /* Read from the connection, unless our buffers are full. */ 523 if (buffer_len(&stdout_buffer) < buffer_high && 524 buffer_len(&stderr_buffer) < buffer_high && 525 channel_not_very_much_buffered_data()) 526 FD_SET(connection_in, *readsetp); 527 /* 528 * Read from stdin, unless we have seen EOF or have very much 529 * buffered data to send to the server. 530 */ 531 if (!stdin_eof && packet_not_very_much_data_to_write()) 532 FD_SET(fileno(stdin), *readsetp); 533 534 /* Select stdout/stderr if have data in buffer. */ 535 if (buffer_len(&stdout_buffer) > 0) 536 FD_SET(fileno(stdout), *writesetp); 537 if (buffer_len(&stderr_buffer) > 0) 538 FD_SET(fileno(stderr), *writesetp); 539 } else { 540 /* channel_prepare_select could have closed the last channel */ 541 if (session_closed && !channel_still_open() && 542 !packet_have_data_to_write()) { 543 /* clear mask since we did not call select() */ 544 memset(*readsetp, 0, *nallocp); 545 memset(*writesetp, 0, *nallocp); 546 return; 547 } else { 548 FD_SET(connection_in, *readsetp); 549 } 550 } 551 552 /* Select server connection if have data to write to the server. */ 553 if (packet_have_data_to_write()) 554 FD_SET(connection_out, *writesetp); 555 556 if (muxserver_sock != -1) 557 FD_SET(muxserver_sock, *readsetp); 558 559 /* 560 * Wait for something to happen. This will suspend the process until 561 * some selected descriptor can be read, written, or has some other 562 * event pending. 563 */ 564 565 if (options.server_alive_interval == 0 || !compat20) 566 tvp = NULL; 567 else { 568 tv.tv_sec = options.server_alive_interval; 569 tv.tv_usec = 0; 570 tvp = &tv; 571 } 572 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 573 if (ret < 0) { 574 char buf[100]; 575 576 /* 577 * We have to clear the select masks, because we return. 578 * We have to return, because the mainloop checks for the flags 579 * set by the signal handlers. 580 */ 581 memset(*readsetp, 0, *nallocp); 582 memset(*writesetp, 0, *nallocp); 583 584 if (errno == EINTR) 585 return; 586 /* Note: we might still have data in the buffers. */ 587 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 588 buffer_append(&stderr_buffer, buf, strlen(buf)); 589 quit_pending = 1; 590 } else if (ret == 0) 591 server_alive_check(); 592 } 593 594 static void 595 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 596 { 597 /* Flush stdout and stderr buffers. */ 598 if (buffer_len(bout) > 0) 599 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 600 buffer_len(bout)); 601 if (buffer_len(berr) > 0) 602 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 603 buffer_len(berr)); 604 605 leave_raw_mode(); 606 607 /* 608 * Free (and clear) the buffer to reduce the amount of data that gets 609 * written to swap. 610 */ 611 buffer_free(bin); 612 buffer_free(bout); 613 buffer_free(berr); 614 615 /* Send the suspend signal to the program itself. */ 616 kill(getpid(), SIGTSTP); 617 618 /* Reset window sizes in case they have changed */ 619 received_window_change_signal = 1; 620 621 /* OK, we have been continued by the user. Reinitialize buffers. */ 622 buffer_init(bin); 623 buffer_init(bout); 624 buffer_init(berr); 625 626 enter_raw_mode(); 627 } 628 629 static void 630 client_process_net_input(fd_set *readset) 631 { 632 int len; 633 char buf[8192]; 634 635 /* 636 * Read input from the server, and add any such data to the buffer of 637 * the packet subsystem. 638 */ 639 if (FD_ISSET(connection_in, readset)) { 640 /* Read as much as possible. */ 641 len = read(connection_in, buf, sizeof(buf)); 642 if (len == 0) { 643 /* 644 * Received EOF. The remote host has closed the 645 * connection. 646 */ 647 snprintf(buf, sizeof buf, 648 "Connection to %.300s closed by remote host.\r\n", 649 host); 650 buffer_append(&stderr_buffer, buf, strlen(buf)); 651 quit_pending = 1; 652 return; 653 } 654 /* 655 * There is a kernel bug on Solaris that causes select to 656 * sometimes wake up even though there is no data available. 657 */ 658 if (len < 0 && (errno == EAGAIN || errno == EINTR)) 659 len = 0; 660 661 if (len < 0) { 662 /* 663 * An error has encountered. Perhaps there is a 664 * network problem. 665 */ 666 snprintf(buf, sizeof buf, 667 "Read from remote host %.300s: %.100s\r\n", 668 host, strerror(errno)); 669 buffer_append(&stderr_buffer, buf, strlen(buf)); 670 quit_pending = 1; 671 return; 672 } 673 packet_process_incoming(buf, len); 674 } 675 } 676 677 static void 678 client_status_confirm(int type, Channel *c, void *ctx) 679 { 680 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 681 char errmsg[256]; 682 int tochan; 683 684 /* XXX supress on mux _client_ quietmode */ 685 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 686 c->ctl_fd != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 687 688 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 689 debug2("%s request accepted on channel %d", 690 cr->request_type, c->self); 691 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 692 if (tochan) { 693 snprintf(errmsg, sizeof(errmsg), 694 "%s request failed\r\n", cr->request_type); 695 } else { 696 snprintf(errmsg, sizeof(errmsg), 697 "%s request failed on channel %d", 698 cr->request_type, c->self); 699 } 700 /* If error occurred on primary session channel, then exit */ 701 if (cr->do_close && c->self == session_ident) 702 fatal("%s", errmsg); 703 /* If error occurred on mux client, append to their stderr */ 704 if (tochan) 705 buffer_append(&c->extended, errmsg, strlen(errmsg)); 706 else 707 error("%s", errmsg); 708 if (cr->do_close) { 709 chan_read_failed(c); 710 chan_write_failed(c); 711 } 712 } 713 xfree(cr); 714 } 715 716 static void 717 client_abandon_status_confirm(Channel *c, void *ctx) 718 { 719 xfree(ctx); 720 } 721 722 static void 723 client_expect_confirm(int id, const char *request, int do_close) 724 { 725 struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); 726 727 cr->request_type = request; 728 cr->do_close = do_close; 729 730 channel_register_status_confirm(id, client_status_confirm, 731 client_abandon_status_confirm, cr); 732 } 733 734 void 735 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 736 { 737 struct global_confirm *gc, *first_gc; 738 739 /* Coalesce identical callbacks */ 740 first_gc = TAILQ_LAST(&global_confirms, global_confirms); 741 if (first_gc && first_gc->cb == cb && first_gc->ctx == ctx) { 742 if (++first_gc->ref_count >= INT_MAX) 743 fatal("%s: first_gc->ref_count = %d", 744 __func__, first_gc->ref_count); 745 return; 746 } 747 748 gc = xmalloc(sizeof(*gc)); 749 gc->cb = cb; 750 gc->ctx = ctx; 751 gc->ref_count = 1; 752 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 753 } 754 755 static void 756 process_cmdline(void) 757 { 758 void (*handler)(int); 759 char *s, *cmd, *cancel_host; 760 int delete = 0; 761 int local = 0; 762 u_short cancel_port; 763 Forward fwd; 764 765 bzero(&fwd, sizeof(fwd)); 766 fwd.listen_host = fwd.connect_host = NULL; 767 768 leave_raw_mode(); 769 handler = signal(SIGINT, SIG_IGN); 770 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 771 if (s == NULL) 772 goto out; 773 while (isspace(*s)) 774 s++; 775 if (*s == '-') 776 s++; /* Skip cmdline '-', if any */ 777 if (*s == '\0') 778 goto out; 779 780 if (*s == 'h' || *s == 'H' || *s == '?') { 781 logit("Commands:"); 782 logit(" -L[bind_address:]port:host:hostport " 783 "Request local forward"); 784 logit(" -R[bind_address:]port:host:hostport " 785 "Request remote forward"); 786 logit(" -KR[bind_address:]port " 787 "Cancel remote forward"); 788 if (!options.permit_local_command) 789 goto out; 790 logit(" !args " 791 "Execute local command"); 792 goto out; 793 } 794 795 if (*s == '!' && options.permit_local_command) { 796 s++; 797 ssh_local_cmd(s); 798 goto out; 799 } 800 801 if (*s == 'K') { 802 delete = 1; 803 s++; 804 } 805 if (*s != 'L' && *s != 'R') { 806 logit("Invalid command."); 807 goto out; 808 } 809 if (*s == 'L') 810 local = 1; 811 if (local && delete) { 812 logit("Not supported."); 813 goto out; 814 } 815 if ((!local || delete) && !compat20) { 816 logit("Not supported for SSH protocol version 1."); 817 goto out; 818 } 819 820 while (isspace(*++s)) 821 ; 822 823 if (delete) { 824 cancel_port = 0; 825 cancel_host = hpdelim(&s); /* may be NULL */ 826 if (s != NULL) { 827 cancel_port = a2port(s); 828 cancel_host = cleanhostname(cancel_host); 829 } else { 830 cancel_port = a2port(cancel_host); 831 cancel_host = NULL; 832 } 833 if (cancel_port == 0) { 834 logit("Bad forwarding close port"); 835 goto out; 836 } 837 channel_request_rforward_cancel(cancel_host, cancel_port); 838 } else { 839 if (!parse_forward(&fwd, s)) { 840 logit("Bad forwarding specification."); 841 goto out; 842 } 843 if (local) { 844 if (channel_setup_local_fwd_listener(fwd.listen_host, 845 fwd.listen_port, fwd.connect_host, 846 fwd.connect_port, options.gateway_ports) < 0) { 847 logit("Port forwarding failed."); 848 goto out; 849 } 850 } else { 851 if (channel_request_remote_forwarding(fwd.listen_host, 852 fwd.listen_port, fwd.connect_host, 853 fwd.connect_port) < 0) { 854 logit("Port forwarding failed."); 855 goto out; 856 } 857 } 858 859 logit("Forwarding port."); 860 } 861 862 out: 863 signal(SIGINT, handler); 864 enter_raw_mode(); 865 if (cmd) 866 xfree(cmd); 867 if (fwd.listen_host != NULL) 868 xfree(fwd.listen_host); 869 if (fwd.connect_host != NULL) 870 xfree(fwd.connect_host); 871 } 872 873 /* 874 * Process the characters one by one, call with c==NULL for proto1 case. 875 */ 876 static int 877 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 878 char *buf, int len) 879 { 880 char string[1024]; 881 pid_t pid; 882 int bytes = 0; 883 u_int i; 884 u_char ch; 885 char *s; 886 int *escape_pendingp, escape_char; 887 struct escape_filter_ctx *efc; 888 889 if (c == NULL) { 890 escape_pendingp = &escape_pending1; 891 escape_char = escape_char1; 892 } else { 893 if (c->filter_ctx == NULL) 894 return 0; 895 efc = (struct escape_filter_ctx *)c->filter_ctx; 896 escape_pendingp = &efc->escape_pending; 897 escape_char = efc->escape_char; 898 } 899 900 if (len <= 0) 901 return (0); 902 903 for (i = 0; i < (u_int)len; i++) { 904 /* Get one character at a time. */ 905 ch = buf[i]; 906 907 if (*escape_pendingp) { 908 /* We have previously seen an escape character. */ 909 /* Clear the flag now. */ 910 *escape_pendingp = 0; 911 912 /* Process the escaped character. */ 913 switch (ch) { 914 case '.': 915 /* Terminate the connection. */ 916 snprintf(string, sizeof string, "%c.\r\n", 917 escape_char); 918 buffer_append(berr, string, strlen(string)); 919 920 if (c && c->ctl_fd != -1) { 921 chan_read_failed(c); 922 chan_write_failed(c); 923 return 0; 924 } else 925 quit_pending = 1; 926 return -1; 927 928 case 'Z' - 64: 929 /* XXX support this for mux clients */ 930 if (c && c->ctl_fd != -1) { 931 noescape: 932 snprintf(string, sizeof string, 933 "%c%c escape not available to " 934 "multiplexed sessions\r\n", 935 escape_char, ch); 936 buffer_append(berr, string, 937 strlen(string)); 938 continue; 939 } 940 /* Suspend the program. Inform the user */ 941 snprintf(string, sizeof string, 942 "%c^Z [suspend ssh]\r\n", escape_char); 943 buffer_append(berr, string, strlen(string)); 944 945 /* Restore terminal modes and suspend. */ 946 client_suspend_self(bin, bout, berr); 947 948 /* We have been continued. */ 949 continue; 950 951 case 'B': 952 if (compat20) { 953 snprintf(string, sizeof string, 954 "%cB\r\n", escape_char); 955 buffer_append(berr, string, 956 strlen(string)); 957 channel_request_start(session_ident, 958 "break", 0); 959 packet_put_int(1000); 960 packet_send(); 961 } 962 continue; 963 964 case 'R': 965 if (compat20) { 966 if (datafellows & SSH_BUG_NOREKEY) 967 logit("Server does not " 968 "support re-keying"); 969 else 970 need_rekeying = 1; 971 } 972 continue; 973 974 case '&': 975 if (c && c->ctl_fd != -1) 976 goto noescape; 977 /* 978 * Detach the program (continue to serve 979 * connections, but put in background and no 980 * more new connections). 981 */ 982 /* Restore tty modes. */ 983 leave_raw_mode(); 984 985 /* Stop listening for new connections. */ 986 channel_stop_listening(); 987 988 snprintf(string, sizeof string, 989 "%c& [backgrounded]\n", escape_char); 990 buffer_append(berr, string, strlen(string)); 991 992 /* Fork into background. */ 993 pid = fork(); 994 if (pid < 0) { 995 error("fork: %.100s", strerror(errno)); 996 continue; 997 } 998 if (pid != 0) { /* This is the parent. */ 999 /* The parent just exits. */ 1000 exit(0); 1001 } 1002 /* The child continues serving connections. */ 1003 if (compat20) { 1004 buffer_append(bin, "\004", 1); 1005 /* fake EOF on stdin */ 1006 return -1; 1007 } else if (!stdin_eof) { 1008 /* 1009 * Sending SSH_CMSG_EOF alone does not 1010 * always appear to be enough. So we 1011 * try to send an EOF character first. 1012 */ 1013 packet_start(SSH_CMSG_STDIN_DATA); 1014 packet_put_string("\004", 1); 1015 packet_send(); 1016 /* Close stdin. */ 1017 stdin_eof = 1; 1018 if (buffer_len(bin) == 0) { 1019 packet_start(SSH_CMSG_EOF); 1020 packet_send(); 1021 } 1022 } 1023 continue; 1024 1025 case '?': 1026 if (c && c->ctl_fd != -1) { 1027 snprintf(string, sizeof string, 1028 "%c?\r\n\ 1029 Supported escape sequences:\r\n\ 1030 %c. - terminate session\r\n\ 1031 %cB - send a BREAK to the remote system\r\n\ 1032 %cC - open a command line\r\n\ 1033 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1034 %c# - list forwarded connections\r\n\ 1035 %c? - this message\r\n\ 1036 %c%c - send the escape character by typing it twice\r\n\ 1037 (Note that escapes are only recognized immediately after newline.)\r\n", 1038 escape_char, escape_char, 1039 escape_char, escape_char, 1040 escape_char, escape_char, 1041 escape_char, escape_char, 1042 escape_char); 1043 } else { 1044 snprintf(string, sizeof string, 1045 "%c?\r\n\ 1046 Supported escape sequences:\r\n\ 1047 %c. - terminate connection (and any multiplexed sessions)\r\n\ 1048 %cB - send a BREAK to the remote system\r\n\ 1049 %cC - open a command line\r\n\ 1050 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1051 %c^Z - suspend ssh\r\n\ 1052 %c# - list forwarded connections\r\n\ 1053 %c& - background ssh (when waiting for connections to terminate)\r\n\ 1054 %c? - this message\r\n\ 1055 %c%c - send the escape character by typing it twice\r\n\ 1056 (Note that escapes are only recognized immediately after newline.)\r\n", 1057 escape_char, escape_char, 1058 escape_char, escape_char, 1059 escape_char, escape_char, 1060 escape_char, escape_char, 1061 escape_char, escape_char, 1062 escape_char); 1063 } 1064 buffer_append(berr, string, strlen(string)); 1065 continue; 1066 1067 case '#': 1068 snprintf(string, sizeof string, "%c#\r\n", 1069 escape_char); 1070 buffer_append(berr, string, strlen(string)); 1071 s = channel_open_message(); 1072 buffer_append(berr, s, strlen(s)); 1073 xfree(s); 1074 continue; 1075 1076 case 'C': 1077 process_cmdline(); 1078 continue; 1079 1080 default: 1081 if (ch != escape_char) { 1082 buffer_put_char(bin, escape_char); 1083 bytes++; 1084 } 1085 /* Escaped characters fall through here */ 1086 break; 1087 } 1088 } else { 1089 /* 1090 * The previous character was not an escape char. 1091 * Check if this is an escape. 1092 */ 1093 if (last_was_cr && ch == escape_char) { 1094 /* 1095 * It is. Set the flag and continue to 1096 * next character. 1097 */ 1098 *escape_pendingp = 1; 1099 continue; 1100 } 1101 } 1102 1103 /* 1104 * Normal character. Record whether it was a newline, 1105 * and append it to the buffer. 1106 */ 1107 last_was_cr = (ch == '\r' || ch == '\n'); 1108 buffer_put_char(bin, ch); 1109 bytes++; 1110 } 1111 return bytes; 1112 } 1113 1114 static void 1115 client_process_input(fd_set *readset) 1116 { 1117 int len; 1118 char buf[8192]; 1119 1120 /* Read input from stdin. */ 1121 if (FD_ISSET(fileno(stdin), readset)) { 1122 /* Read as much as possible. */ 1123 len = read(fileno(stdin), buf, sizeof(buf)); 1124 if (len < 0 && (errno == EAGAIN || errno == EINTR)) 1125 return; /* we'll try again later */ 1126 if (len <= 0) { 1127 /* 1128 * Received EOF or error. They are treated 1129 * similarly, except that an error message is printed 1130 * if it was an error condition. 1131 */ 1132 if (len < 0) { 1133 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1134 strerror(errno)); 1135 buffer_append(&stderr_buffer, buf, strlen(buf)); 1136 } 1137 /* Mark that we have seen EOF. */ 1138 stdin_eof = 1; 1139 /* 1140 * Send an EOF message to the server unless there is 1141 * data in the buffer. If there is data in the 1142 * buffer, no message will be sent now. Code 1143 * elsewhere will send the EOF when the buffer 1144 * becomes empty if stdin_eof is set. 1145 */ 1146 if (buffer_len(&stdin_buffer) == 0) { 1147 packet_start(SSH_CMSG_EOF); 1148 packet_send(); 1149 } 1150 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1151 /* 1152 * Normal successful read, and no escape character. 1153 * Just append the data to buffer. 1154 */ 1155 buffer_append(&stdin_buffer, buf, len); 1156 } else { 1157 /* 1158 * Normal, successful read. But we have an escape 1159 * character and have to process the characters one 1160 * by one. 1161 */ 1162 if (process_escapes(NULL, &stdin_buffer, 1163 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1164 return; 1165 } 1166 } 1167 } 1168 1169 static void 1170 client_process_output(fd_set *writeset) 1171 { 1172 int len; 1173 char buf[100]; 1174 1175 /* Write buffered output to stdout. */ 1176 if (FD_ISSET(fileno(stdout), writeset)) { 1177 /* Write as much data as possible. */ 1178 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1179 buffer_len(&stdout_buffer)); 1180 if (len <= 0) { 1181 if (errno == EINTR || errno == EAGAIN) 1182 len = 0; 1183 else { 1184 /* 1185 * An error or EOF was encountered. Put an 1186 * error message to stderr buffer. 1187 */ 1188 snprintf(buf, sizeof buf, 1189 "write stdout: %.50s\r\n", strerror(errno)); 1190 buffer_append(&stderr_buffer, buf, strlen(buf)); 1191 quit_pending = 1; 1192 return; 1193 } 1194 } 1195 /* Consume printed data from the buffer. */ 1196 buffer_consume(&stdout_buffer, len); 1197 stdout_bytes += len; 1198 } 1199 /* Write buffered output to stderr. */ 1200 if (FD_ISSET(fileno(stderr), writeset)) { 1201 /* Write as much data as possible. */ 1202 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1203 buffer_len(&stderr_buffer)); 1204 if (len <= 0) { 1205 if (errno == EINTR || errno == EAGAIN) 1206 len = 0; 1207 else { 1208 /* 1209 * EOF or error, but can't even print 1210 * error message. 1211 */ 1212 quit_pending = 1; 1213 return; 1214 } 1215 } 1216 /* Consume printed characters from the buffer. */ 1217 buffer_consume(&stderr_buffer, len); 1218 stderr_bytes += len; 1219 } 1220 } 1221 1222 /* 1223 * Get packets from the connection input buffer, and process them as long as 1224 * there are packets available. 1225 * 1226 * Any unknown packets received during the actual 1227 * session cause the session to terminate. This is 1228 * intended to make debugging easier since no 1229 * confirmations are sent. Any compatible protocol 1230 * extensions must be negotiated during the 1231 * preparatory phase. 1232 */ 1233 1234 static void 1235 client_process_buffered_input_packets(void) 1236 { 1237 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1238 compat20 ? xxx_kex : NULL); 1239 } 1240 1241 /* scan buf[] for '~' before sending data to the peer */ 1242 1243 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1244 void * 1245 client_new_escape_filter_ctx(int escape_char) 1246 { 1247 struct escape_filter_ctx *ret; 1248 1249 ret = xmalloc(sizeof(*ret)); 1250 ret->escape_pending = 0; 1251 ret->escape_char = escape_char; 1252 return (void *)ret; 1253 } 1254 1255 /* Free the escape filter context on channel free */ 1256 void 1257 client_filter_cleanup(int cid, void *ctx) 1258 { 1259 xfree(ctx); 1260 } 1261 1262 int 1263 client_simple_escape_filter(Channel *c, char *buf, int len) 1264 { 1265 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1266 return 0; 1267 1268 return process_escapes(c, &c->input, &c->output, &c->extended, 1269 buf, len); 1270 } 1271 1272 static void 1273 client_channel_closed(int id, void *arg) 1274 { 1275 channel_cancel_cleanup(id); 1276 session_closed = 1; 1277 leave_raw_mode(); 1278 } 1279 1280 /* 1281 * Implements the interactive session with the server. This is called after 1282 * the user has been authenticated, and a command has been started on the 1283 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1284 * used as an escape character for terminating or suspending the session. 1285 */ 1286 1287 int 1288 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1289 { 1290 fd_set *readset = NULL, *writeset = NULL; 1291 double start_time, total_time; 1292 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1293 u_int nalloc = 0; 1294 char buf[100]; 1295 1296 debug("Entering interactive session."); 1297 1298 start_time = get_current_time(); 1299 1300 /* Initialize variables. */ 1301 escape_pending1 = 0; 1302 last_was_cr = 1; 1303 exit_status = -1; 1304 stdin_eof = 0; 1305 buffer_high = 64 * 1024; 1306 connection_in = packet_get_connection_in(); 1307 connection_out = packet_get_connection_out(); 1308 max_fd = MAX(connection_in, connection_out); 1309 if (muxserver_sock != -1) 1310 max_fd = MAX(max_fd, muxserver_sock); 1311 1312 if (!compat20) { 1313 /* enable nonblocking unless tty */ 1314 if (!isatty(fileno(stdin))) 1315 set_nonblock(fileno(stdin)); 1316 if (!isatty(fileno(stdout))) 1317 set_nonblock(fileno(stdout)); 1318 if (!isatty(fileno(stderr))) 1319 set_nonblock(fileno(stderr)); 1320 max_fd = MAX(max_fd, fileno(stdin)); 1321 max_fd = MAX(max_fd, fileno(stdout)); 1322 max_fd = MAX(max_fd, fileno(stderr)); 1323 } 1324 stdin_bytes = 0; 1325 stdout_bytes = 0; 1326 stderr_bytes = 0; 1327 quit_pending = 0; 1328 escape_char1 = escape_char_arg; 1329 1330 /* Initialize buffers. */ 1331 buffer_init(&stdin_buffer); 1332 buffer_init(&stdout_buffer); 1333 buffer_init(&stderr_buffer); 1334 1335 client_init_dispatch(); 1336 1337 /* 1338 * Set signal handlers, (e.g. to restore non-blocking mode) 1339 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1340 */ 1341 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1342 signal(SIGHUP, signal_handler); 1343 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1344 signal(SIGINT, signal_handler); 1345 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1346 signal(SIGQUIT, signal_handler); 1347 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1348 signal(SIGTERM, signal_handler); 1349 signal(SIGWINCH, window_change_handler); 1350 1351 if (have_pty) 1352 enter_raw_mode(); 1353 1354 if (compat20) { 1355 session_ident = ssh2_chan_id; 1356 if (escape_char_arg != SSH_ESCAPECHAR_NONE) 1357 channel_register_filter(session_ident, 1358 client_simple_escape_filter, NULL, 1359 client_filter_cleanup, 1360 client_new_escape_filter_ctx(escape_char_arg)); 1361 if (session_ident != -1) 1362 channel_register_cleanup(session_ident, 1363 client_channel_closed, 0); 1364 } else { 1365 /* Check if we should immediately send eof on stdin. */ 1366 client_check_initial_eof_on_stdin(); 1367 } 1368 1369 /* Main loop of the client for the interactive session mode. */ 1370 while (!quit_pending) { 1371 1372 /* Process buffered packets sent by the server. */ 1373 client_process_buffered_input_packets(); 1374 1375 if (compat20 && session_closed && !channel_still_open()) 1376 break; 1377 1378 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1379 1380 if (rekeying) { 1381 debug("rekeying in progress"); 1382 } else { 1383 /* 1384 * Make packets of buffered stdin data, and buffer 1385 * them for sending to the server. 1386 */ 1387 if (!compat20) 1388 client_make_packets_from_stdin_data(); 1389 1390 /* 1391 * Make packets from buffered channel data, and 1392 * enqueue them for sending to the server. 1393 */ 1394 if (packet_not_very_much_data_to_write()) 1395 channel_output_poll(); 1396 1397 /* 1398 * Check if the window size has changed, and buffer a 1399 * message about it to the server if so. 1400 */ 1401 client_check_window_change(); 1402 1403 if (quit_pending) 1404 break; 1405 } 1406 /* 1407 * Wait until we have something to do (something becomes 1408 * available on one of the descriptors). 1409 */ 1410 max_fd2 = max_fd; 1411 client_wait_until_can_do_something(&readset, &writeset, 1412 &max_fd2, &nalloc, rekeying); 1413 1414 if (quit_pending) 1415 break; 1416 1417 /* Do channel operations unless rekeying in progress. */ 1418 if (!rekeying) { 1419 channel_after_select(readset, writeset); 1420 if (need_rekeying || packet_need_rekeying()) { 1421 debug("need rekeying"); 1422 xxx_kex->done = 0; 1423 kex_send_kexinit(xxx_kex); 1424 need_rekeying = 0; 1425 } 1426 } 1427 1428 /* Buffer input from the connection. */ 1429 client_process_net_input(readset); 1430 1431 /* Accept control connections. */ 1432 if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) { 1433 if (muxserver_accept_control()) 1434 quit_pending = 1; 1435 } 1436 1437 if (quit_pending) 1438 break; 1439 1440 if (!compat20) { 1441 /* Buffer data from stdin */ 1442 client_process_input(readset); 1443 /* 1444 * Process output to stdout and stderr. Output to 1445 * the connection is processed elsewhere (above). 1446 */ 1447 client_process_output(writeset); 1448 } 1449 1450 /* 1451 * Send as much buffered packet data as possible to the 1452 * sender. 1453 */ 1454 if (FD_ISSET(connection_out, writeset)) 1455 packet_write_poll(); 1456 } 1457 if (readset) 1458 xfree(readset); 1459 if (writeset) 1460 xfree(writeset); 1461 1462 /* Terminate the session. */ 1463 1464 /* Stop watching for window change. */ 1465 signal(SIGWINCH, SIG_DFL); 1466 1467 channel_free_all(); 1468 1469 if (have_pty) 1470 leave_raw_mode(); 1471 1472 /* restore blocking io */ 1473 if (!isatty(fileno(stdin))) 1474 unset_nonblock(fileno(stdin)); 1475 if (!isatty(fileno(stdout))) 1476 unset_nonblock(fileno(stdout)); 1477 if (!isatty(fileno(stderr))) 1478 unset_nonblock(fileno(stderr)); 1479 1480 /* 1481 * If there was no shell or command requested, there will be no remote 1482 * exit status to be returned. In that case, clear error code if the 1483 * connection was deliberately terminated at this end. 1484 */ 1485 if (no_shell_flag && received_signal == SIGTERM) { 1486 received_signal = 0; 1487 exit_status = 0; 1488 } 1489 1490 if (received_signal) 1491 fatal("Killed by signal %d.", (int) received_signal); 1492 1493 /* 1494 * In interactive mode (with pseudo tty) display a message indicating 1495 * that the connection has been closed. 1496 */ 1497 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1498 snprintf(buf, sizeof buf, 1499 "Connection to %.64s closed.\r\n", host); 1500 buffer_append(&stderr_buffer, buf, strlen(buf)); 1501 } 1502 1503 /* Output any buffered data for stdout. */ 1504 while (buffer_len(&stdout_buffer) > 0) { 1505 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1506 buffer_len(&stdout_buffer)); 1507 if (len <= 0) { 1508 error("Write failed flushing stdout buffer."); 1509 break; 1510 } 1511 buffer_consume(&stdout_buffer, len); 1512 stdout_bytes += len; 1513 } 1514 1515 /* Output any buffered data for stderr. */ 1516 while (buffer_len(&stderr_buffer) > 0) { 1517 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1518 buffer_len(&stderr_buffer)); 1519 if (len <= 0) { 1520 error("Write failed flushing stderr buffer."); 1521 break; 1522 } 1523 buffer_consume(&stderr_buffer, len); 1524 stderr_bytes += len; 1525 } 1526 1527 /* Clear and free any buffers. */ 1528 memset(buf, 0, sizeof(buf)); 1529 buffer_free(&stdin_buffer); 1530 buffer_free(&stdout_buffer); 1531 buffer_free(&stderr_buffer); 1532 1533 /* Report bytes transferred, and transfer rates. */ 1534 total_time = get_current_time() - start_time; 1535 debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f " 1536 "seconds", stdin_bytes, stdout_bytes, stderr_bytes, total_time); 1537 if (total_time > 0) 1538 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f", 1539 stdin_bytes / total_time, stdout_bytes / total_time, 1540 stderr_bytes / total_time); 1541 1542 /* Return the exit status of the program. */ 1543 debug("Exit status %d", exit_status); 1544 return exit_status; 1545 } 1546 1547 /*********/ 1548 1549 static void 1550 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1551 { 1552 u_int data_len; 1553 char *data = packet_get_string(&data_len); 1554 packet_check_eom(); 1555 buffer_append(&stdout_buffer, data, data_len); 1556 memset(data, 0, data_len); 1557 xfree(data); 1558 } 1559 static void 1560 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1561 { 1562 u_int data_len; 1563 char *data = packet_get_string(&data_len); 1564 packet_check_eom(); 1565 buffer_append(&stderr_buffer, data, data_len); 1566 memset(data, 0, data_len); 1567 xfree(data); 1568 } 1569 static void 1570 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1571 { 1572 exit_status = packet_get_int(); 1573 packet_check_eom(); 1574 /* Acknowledge the exit. */ 1575 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1576 packet_send(); 1577 /* 1578 * Must wait for packet to be sent since we are 1579 * exiting the loop. 1580 */ 1581 packet_write_wait(); 1582 /* Flag that we want to exit. */ 1583 quit_pending = 1; 1584 } 1585 static void 1586 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1587 { 1588 Channel *c = NULL; 1589 int remote_id, sock; 1590 1591 /* Read the remote channel number from the message. */ 1592 remote_id = packet_get_int(); 1593 packet_check_eom(); 1594 1595 /* 1596 * Get a connection to the local authentication agent (this may again 1597 * get forwarded). 1598 */ 1599 sock = ssh_get_authentication_socket(); 1600 1601 /* 1602 * If we could not connect the agent, send an error message back to 1603 * the server. This should never happen unless the agent dies, 1604 * because authentication forwarding is only enabled if we have an 1605 * agent. 1606 */ 1607 if (sock >= 0) { 1608 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1609 -1, 0, 0, 0, "authentication agent connection", 1); 1610 c->remote_id = remote_id; 1611 c->force_drain = 1; 1612 } 1613 if (c == NULL) { 1614 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1615 packet_put_int(remote_id); 1616 } else { 1617 /* Send a confirmation to the remote host. */ 1618 debug("Forwarding authentication connection."); 1619 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1620 packet_put_int(remote_id); 1621 packet_put_int(c->self); 1622 } 1623 packet_send(); 1624 } 1625 1626 static Channel * 1627 client_request_forwarded_tcpip(const char *request_type, int rchan) 1628 { 1629 Channel *c = NULL; 1630 char *listen_address, *originator_address; 1631 int listen_port, originator_port; 1632 1633 /* Get rest of the packet */ 1634 listen_address = packet_get_string(NULL); 1635 listen_port = packet_get_int(); 1636 originator_address = packet_get_string(NULL); 1637 originator_port = packet_get_int(); 1638 packet_check_eom(); 1639 1640 debug("client_request_forwarded_tcpip: listen %s port %d, " 1641 "originator %s port %d", listen_address, listen_port, 1642 originator_address, originator_port); 1643 1644 c = channel_connect_by_listen_address(listen_port, 1645 "forwarded-tcpip", originator_address); 1646 1647 xfree(originator_address); 1648 xfree(listen_address); 1649 return c; 1650 } 1651 1652 static Channel * 1653 client_request_x11(const char *request_type, int rchan) 1654 { 1655 Channel *c = NULL; 1656 char *originator; 1657 int originator_port; 1658 int sock; 1659 1660 if (!options.forward_x11) { 1661 error("Warning: ssh server tried X11 forwarding."); 1662 error("Warning: this is probably a break-in attempt by a " 1663 "malicious server."); 1664 return NULL; 1665 } 1666 originator = packet_get_string(NULL); 1667 if (datafellows & SSH_BUG_X11FWD) { 1668 debug2("buggy server: x11 request w/o originator_port"); 1669 originator_port = 0; 1670 } else { 1671 originator_port = packet_get_int(); 1672 } 1673 packet_check_eom(); 1674 /* XXX check permission */ 1675 debug("client_request_x11: request from %s %d", originator, 1676 originator_port); 1677 xfree(originator); 1678 sock = x11_connect_display(); 1679 if (sock < 0) 1680 return NULL; 1681 c = channel_new("x11", 1682 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1683 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1684 c->force_drain = 1; 1685 return c; 1686 } 1687 1688 static Channel * 1689 client_request_agent(const char *request_type, int rchan) 1690 { 1691 Channel *c = NULL; 1692 int sock; 1693 1694 if (!options.forward_agent) { 1695 error("Warning: ssh server tried agent forwarding."); 1696 error("Warning: this is probably a break-in attempt by a " 1697 "malicious server."); 1698 return NULL; 1699 } 1700 sock = ssh_get_authentication_socket(); 1701 if (sock < 0) 1702 return NULL; 1703 c = channel_new("authentication agent connection", 1704 SSH_CHANNEL_OPEN, sock, sock, -1, 1705 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1706 "authentication agent connection", 1); 1707 c->force_drain = 1; 1708 return c; 1709 } 1710 1711 int 1712 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1713 { 1714 Channel *c; 1715 int fd; 1716 1717 if (tun_mode == SSH_TUNMODE_NO) 1718 return 0; 1719 1720 if (!compat20) { 1721 error("Tunnel forwarding is not support for protocol 1"); 1722 return -1; 1723 } 1724 1725 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1726 1727 /* Open local tunnel device */ 1728 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1729 error("Tunnel device open failed."); 1730 return -1; 1731 } 1732 1733 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1734 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1735 c->datagram = 1; 1736 1737 packet_start(SSH2_MSG_CHANNEL_OPEN); 1738 packet_put_cstring("tun@openssh.com"); 1739 packet_put_int(c->self); 1740 packet_put_int(c->local_window_max); 1741 packet_put_int(c->local_maxpacket); 1742 packet_put_int(tun_mode); 1743 packet_put_int(remote_tun); 1744 packet_send(); 1745 1746 return 0; 1747 } 1748 1749 /* XXXX move to generic input handler */ 1750 static void 1751 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1752 { 1753 Channel *c = NULL; 1754 char *ctype; 1755 int rchan; 1756 u_int rmaxpack, rwindow, len; 1757 1758 ctype = packet_get_string(&len); 1759 rchan = packet_get_int(); 1760 rwindow = packet_get_int(); 1761 rmaxpack = packet_get_int(); 1762 1763 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1764 ctype, rchan, rwindow, rmaxpack); 1765 1766 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1767 c = client_request_forwarded_tcpip(ctype, rchan); 1768 } else if (strcmp(ctype, "x11") == 0) { 1769 c = client_request_x11(ctype, rchan); 1770 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1771 c = client_request_agent(ctype, rchan); 1772 } 1773 /* XXX duplicate : */ 1774 if (c != NULL) { 1775 debug("confirm %s", ctype); 1776 c->remote_id = rchan; 1777 c->remote_window = rwindow; 1778 c->remote_maxpacket = rmaxpack; 1779 if (c->type != SSH_CHANNEL_CONNECTING) { 1780 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 1781 packet_put_int(c->remote_id); 1782 packet_put_int(c->self); 1783 packet_put_int(c->local_window); 1784 packet_put_int(c->local_maxpacket); 1785 packet_send(); 1786 } 1787 } else { 1788 debug("failure %s", ctype); 1789 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 1790 packet_put_int(rchan); 1791 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 1792 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 1793 packet_put_cstring("open failed"); 1794 packet_put_cstring(""); 1795 } 1796 packet_send(); 1797 } 1798 xfree(ctype); 1799 } 1800 static void 1801 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 1802 { 1803 Channel *c = NULL; 1804 int exitval, id, reply, success = 0; 1805 char *rtype; 1806 1807 id = packet_get_int(); 1808 rtype = packet_get_string(NULL); 1809 reply = packet_get_char(); 1810 1811 debug("client_input_channel_req: channel %d rtype %s reply %d", 1812 id, rtype, reply); 1813 1814 if (id == -1) { 1815 error("client_input_channel_req: request for channel -1"); 1816 } else if ((c = channel_lookup(id)) == NULL) { 1817 error("client_input_channel_req: channel %d: " 1818 "unknown channel", id); 1819 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1820 packet_check_eom(); 1821 chan_rcvd_eow(c); 1822 } else if (strcmp(rtype, "exit-status") == 0) { 1823 exitval = packet_get_int(); 1824 if (id == session_ident) { 1825 success = 1; 1826 exit_status = exitval; 1827 } else if (c->ctl_fd == -1) { 1828 error("client_input_channel_req: unexpected channel %d", 1829 session_ident); 1830 } else { 1831 atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval)); 1832 success = 1; 1833 } 1834 packet_check_eom(); 1835 } 1836 if (reply) { 1837 packet_start(success ? 1838 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 1839 packet_put_int(id); 1840 packet_send(); 1841 } 1842 xfree(rtype); 1843 } 1844 static void 1845 client_input_global_request(int type, u_int32_t seq, void *ctxt) 1846 { 1847 char *rtype; 1848 int want_reply; 1849 int success = 0; 1850 1851 rtype = packet_get_string(NULL); 1852 want_reply = packet_get_char(); 1853 debug("client_input_global_request: rtype %s want_reply %d", 1854 rtype, want_reply); 1855 if (want_reply) { 1856 packet_start(success ? 1857 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 1858 packet_send(); 1859 packet_write_wait(); 1860 } 1861 xfree(rtype); 1862 } 1863 1864 void 1865 client_session2_setup(int id, int want_tty, int want_subsystem, 1866 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 1867 { 1868 int len; 1869 Channel *c = NULL; 1870 1871 debug2("%s: id %d", __func__, id); 1872 1873 if ((c = channel_lookup(id)) == NULL) 1874 fatal("client_session2_setup: channel %d: unknown channel", id); 1875 1876 if (want_tty) { 1877 struct winsize ws; 1878 1879 /* Store window size in the packet. */ 1880 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 1881 memset(&ws, 0, sizeof(ws)); 1882 1883 channel_request_start(id, "pty-req", 1); 1884 client_expect_confirm(id, "PTY allocation", 0); 1885 packet_put_cstring(term != NULL ? term : ""); 1886 packet_put_int((u_int)ws.ws_col); 1887 packet_put_int((u_int)ws.ws_row); 1888 packet_put_int((u_int)ws.ws_xpixel); 1889 packet_put_int((u_int)ws.ws_ypixel); 1890 if (tiop == NULL) 1891 tiop = get_saved_tio(); 1892 tty_make_modes(-1, tiop); 1893 packet_send(); 1894 /* XXX wait for reply */ 1895 c->client_tty = 1; 1896 } 1897 1898 /* Transfer any environment variables from client to server */ 1899 if (options.num_send_env != 0 && env != NULL) { 1900 int i, j, matched; 1901 char *name, *val; 1902 1903 debug("Sending environment."); 1904 for (i = 0; env[i] != NULL; i++) { 1905 /* Split */ 1906 name = xstrdup(env[i]); 1907 if ((val = strchr(name, '=')) == NULL) { 1908 xfree(name); 1909 continue; 1910 } 1911 *val++ = '\0'; 1912 1913 matched = 0; 1914 for (j = 0; j < options.num_send_env; j++) { 1915 if (match_pattern(name, options.send_env[j])) { 1916 matched = 1; 1917 break; 1918 } 1919 } 1920 if (!matched) { 1921 debug3("Ignored env %s", name); 1922 xfree(name); 1923 continue; 1924 } 1925 1926 debug("Sending env %s = %s", name, val); 1927 channel_request_start(id, "env", 0); 1928 packet_put_cstring(name); 1929 packet_put_cstring(val); 1930 packet_send(); 1931 xfree(name); 1932 } 1933 } 1934 1935 len = buffer_len(cmd); 1936 if (len > 0) { 1937 if (len > 900) 1938 len = 900; 1939 if (want_subsystem) { 1940 debug("Sending subsystem: %.*s", 1941 len, (u_char*)buffer_ptr(cmd)); 1942 channel_request_start(id, "subsystem", 1); 1943 client_expect_confirm(id, "subsystem", 1); 1944 } else { 1945 debug("Sending command: %.*s", 1946 len, (u_char*)buffer_ptr(cmd)); 1947 channel_request_start(id, "exec", 1); 1948 client_expect_confirm(id, "exec", 1); 1949 } 1950 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 1951 packet_send(); 1952 } else { 1953 channel_request_start(id, "shell", 1); 1954 client_expect_confirm(id, "shell", 1); 1955 packet_send(); 1956 } 1957 } 1958 1959 static void 1960 client_init_dispatch_20(void) 1961 { 1962 dispatch_init(&dispatch_protocol_error); 1963 1964 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 1965 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 1966 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 1967 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 1968 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 1969 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 1970 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 1971 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 1972 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 1973 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 1974 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 1975 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 1976 1977 /* rekeying */ 1978 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 1979 1980 /* global request reply messages */ 1981 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 1982 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 1983 } 1984 1985 static void 1986 client_init_dispatch_13(void) 1987 { 1988 dispatch_init(NULL); 1989 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 1990 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 1991 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 1992 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 1993 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 1994 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 1995 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 1996 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 1997 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 1998 1999 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2000 &client_input_agent_open : &deny_input_open); 2001 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2002 &x11_input_open : &deny_input_open); 2003 } 2004 2005 static void 2006 client_init_dispatch_15(void) 2007 { 2008 client_init_dispatch_13(); 2009 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2010 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2011 } 2012 2013 static void 2014 client_init_dispatch(void) 2015 { 2016 if (compat20) 2017 client_init_dispatch_20(); 2018 else if (compat13) 2019 client_init_dispatch_13(); 2020 else 2021 client_init_dispatch_15(); 2022 } 2023 2024 /* client specific fatal cleanup */ 2025 void 2026 cleanup_exit(int i) 2027 { 2028 leave_raw_mode(); 2029 leave_non_blocking(); 2030 if (options.control_path != NULL && muxserver_sock != -1) 2031 unlink(options.control_path); 2032 _exit(i); 2033 } 2034