1 /* $OpenBSD: clientloop.c,v 1.219 2010/03/13 21:10:38 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 #include "includes.h" 63 64 #include <sys/types.h> 65 #include <sys/ioctl.h> 66 #include <sys/param.h> 67 #ifdef HAVE_SYS_STAT_H 68 # include <sys/stat.h> 69 #endif 70 #ifdef HAVE_SYS_TIME_H 71 # include <sys/time.h> 72 #endif 73 #include <sys/socket.h> 74 75 #include <ctype.h> 76 #include <errno.h> 77 #ifdef HAVE_PATHS_H 78 #include <paths.h> 79 #endif 80 #include <signal.h> 81 #include <stdarg.h> 82 #include <stdio.h> 83 #include <stdlib.h> 84 #include <string.h> 85 #include <termios.h> 86 #include <pwd.h> 87 #include <unistd.h> 88 89 #include "openbsd-compat/sys-queue.h" 90 #include "xmalloc.h" 91 #include "ssh.h" 92 #include "ssh1.h" 93 #include "ssh2.h" 94 #include "packet.h" 95 #include "buffer.h" 96 #include "compat.h" 97 #include "channels.h" 98 #include "dispatch.h" 99 #include "key.h" 100 #include "cipher.h" 101 #include "kex.h" 102 #include "log.h" 103 #include "readconf.h" 104 #include "clientloop.h" 105 #include "sshconnect.h" 106 #include "authfd.h" 107 #include "atomicio.h" 108 #include "sshpty.h" 109 #include "misc.h" 110 #include "match.h" 111 #include "msg.h" 112 #include "roaming.h" 113 114 /* import options */ 115 extern Options options; 116 117 /* Flag indicating that stdin should be redirected from /dev/null. */ 118 extern int stdin_null_flag; 119 120 /* Flag indicating that no shell has been requested */ 121 extern int no_shell_flag; 122 123 /* Control socket */ 124 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 125 126 /* 127 * Name of the host we are connecting to. This is the name given on the 128 * command line, or the HostName specified for the user-supplied name in a 129 * configuration file. 130 */ 131 extern char *host; 132 133 /* Force TTY allocation */ 134 extern int force_tty_flag; 135 136 /* 137 * Flag to indicate that we have received a window change signal which has 138 * not yet been processed. This will cause a message indicating the new 139 * window size to be sent to the server a little later. This is volatile 140 * because this is updated in a signal handler. 141 */ 142 static volatile sig_atomic_t received_window_change_signal = 0; 143 static volatile sig_atomic_t received_signal = 0; 144 145 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 146 static int in_non_blocking_mode = 0; 147 148 /* Common data for the client loop code. */ 149 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 150 static int escape_char1; /* Escape character. (proto1 only) */ 151 static int escape_pending1; /* Last character was an escape (proto1 only) */ 152 static int last_was_cr; /* Last character was a newline. */ 153 static int exit_status; /* Used to store the command exit status. */ 154 static int stdin_eof; /* EOF has been encountered on stderr. */ 155 static Buffer stdin_buffer; /* Buffer for stdin data. */ 156 static Buffer stdout_buffer; /* Buffer for stdout data. */ 157 static Buffer stderr_buffer; /* Buffer for stderr data. */ 158 static u_int buffer_high;/* Soft max buffer size. */ 159 static int connection_in; /* Connection to server (input). */ 160 static int connection_out; /* Connection to server (output). */ 161 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 162 static int session_closed = 0; /* In SSH2: login session closed. */ 163 164 static void client_init_dispatch(void); 165 int session_ident = -1; 166 167 int session_resumed = 0; 168 169 /* Track escape per proto2 channel */ 170 struct escape_filter_ctx { 171 int escape_pending; 172 int escape_char; 173 }; 174 175 /* Context for channel confirmation replies */ 176 struct channel_reply_ctx { 177 const char *request_type; 178 int id, do_close; 179 }; 180 181 /* Global request success/failure callbacks */ 182 struct global_confirm { 183 TAILQ_ENTRY(global_confirm) entry; 184 global_confirm_cb *cb; 185 void *ctx; 186 int ref_count; 187 }; 188 TAILQ_HEAD(global_confirms, global_confirm); 189 static struct global_confirms global_confirms = 190 TAILQ_HEAD_INITIALIZER(global_confirms); 191 192 /*XXX*/ 193 extern Kex *xxx_kex; 194 195 void ssh_process_session2_setup(int, int, int, Buffer *); 196 197 /* Restores stdin to blocking mode. */ 198 199 static void 200 leave_non_blocking(void) 201 { 202 if (in_non_blocking_mode) { 203 unset_nonblock(fileno(stdin)); 204 in_non_blocking_mode = 0; 205 } 206 } 207 208 /* Puts stdin terminal in non-blocking mode. */ 209 210 static void 211 enter_non_blocking(void) 212 { 213 in_non_blocking_mode = 1; 214 set_nonblock(fileno(stdin)); 215 } 216 217 /* 218 * Signal handler for the window change signal (SIGWINCH). This just sets a 219 * flag indicating that the window has changed. 220 */ 221 /*ARGSUSED */ 222 static void 223 window_change_handler(int sig) 224 { 225 received_window_change_signal = 1; 226 signal(SIGWINCH, window_change_handler); 227 } 228 229 /* 230 * Signal handler for signals that cause the program to terminate. These 231 * signals must be trapped to restore terminal modes. 232 */ 233 /*ARGSUSED */ 234 static void 235 signal_handler(int sig) 236 { 237 received_signal = sig; 238 quit_pending = 1; 239 } 240 241 /* 242 * Returns current time in seconds from Jan 1, 1970 with the maximum 243 * available resolution. 244 */ 245 246 static double 247 get_current_time(void) 248 { 249 struct timeval tv; 250 gettimeofday(&tv, NULL); 251 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 252 } 253 254 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 255 void 256 client_x11_get_proto(const char *display, const char *xauth_path, 257 u_int trusted, char **_proto, char **_data) 258 { 259 char cmd[1024]; 260 char line[512]; 261 char xdisplay[512]; 262 static char proto[512], data[512]; 263 FILE *f; 264 int got_data = 0, generated = 0, do_unlink = 0, i; 265 char *xauthdir, *xauthfile; 266 struct stat st; 267 268 xauthdir = xauthfile = NULL; 269 *_proto = proto; 270 *_data = data; 271 proto[0] = data[0] = '\0'; 272 273 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 274 debug("No xauth program."); 275 } else { 276 if (display == NULL) { 277 debug("x11_get_proto: DISPLAY not set"); 278 return; 279 } 280 /* 281 * Handle FamilyLocal case where $DISPLAY does 282 * not match an authorization entry. For this we 283 * just try "xauth list unix:displaynum.screennum". 284 * XXX: "localhost" match to determine FamilyLocal 285 * is not perfect. 286 */ 287 if (strncmp(display, "localhost:", 10) == 0) { 288 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 289 display + 10); 290 display = xdisplay; 291 } 292 if (trusted == 0) { 293 xauthdir = xmalloc(MAXPATHLEN); 294 xauthfile = xmalloc(MAXPATHLEN); 295 strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); 296 if (mkdtemp(xauthdir) != NULL) { 297 do_unlink = 1; 298 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", 299 xauthdir); 300 snprintf(cmd, sizeof(cmd), 301 "%s -f %s generate %s " SSH_X11_PROTO 302 " untrusted timeout 1200 2>" _PATH_DEVNULL, 303 xauth_path, xauthfile, display); 304 debug2("x11_get_proto: %s", cmd); 305 if (system(cmd) == 0) 306 generated = 1; 307 } 308 } 309 310 /* 311 * When in untrusted mode, we read the cookie only if it was 312 * successfully generated as an untrusted one in the step 313 * above. 314 */ 315 if (trusted || generated) { 316 snprintf(cmd, sizeof(cmd), 317 "%s %s%s list %s 2>" _PATH_DEVNULL, 318 xauth_path, 319 generated ? "-f " : "" , 320 generated ? xauthfile : "", 321 display); 322 debug2("x11_get_proto: %s", cmd); 323 f = popen(cmd, "r"); 324 if (f && fgets(line, sizeof(line), f) && 325 sscanf(line, "%*s %511s %511s", proto, data) == 2) 326 got_data = 1; 327 if (f) 328 pclose(f); 329 } else 330 error("Warning: untrusted X11 forwarding setup failed: " 331 "xauth key data not generated"); 332 } 333 334 if (do_unlink) { 335 unlink(xauthfile); 336 rmdir(xauthdir); 337 } 338 if (xauthdir) 339 xfree(xauthdir); 340 if (xauthfile) 341 xfree(xauthfile); 342 343 /* 344 * If we didn't get authentication data, just make up some 345 * data. The forwarding code will check the validity of the 346 * response anyway, and substitute this data. The X11 347 * server, however, will ignore this fake data and use 348 * whatever authentication mechanisms it was using otherwise 349 * for the local connection. 350 */ 351 if (!got_data) { 352 u_int32_t rnd = 0; 353 354 logit("Warning: No xauth data; " 355 "using fake authentication data for X11 forwarding."); 356 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 357 for (i = 0; i < 16; i++) { 358 if (i % 4 == 0) 359 rnd = arc4random(); 360 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 361 rnd & 0xff); 362 rnd >>= 8; 363 } 364 } 365 } 366 367 /* 368 * This is called when the interactive is entered. This checks if there is 369 * an EOF coming on stdin. We must check this explicitly, as select() does 370 * not appear to wake up when redirecting from /dev/null. 371 */ 372 373 static void 374 client_check_initial_eof_on_stdin(void) 375 { 376 int len; 377 char buf[1]; 378 379 /* 380 * If standard input is to be "redirected from /dev/null", we simply 381 * mark that we have seen an EOF and send an EOF message to the 382 * server. Otherwise, we try to read a single character; it appears 383 * that for some files, such /dev/null, select() never wakes up for 384 * read for this descriptor, which means that we never get EOF. This 385 * way we will get the EOF if stdin comes from /dev/null or similar. 386 */ 387 if (stdin_null_flag) { 388 /* Fake EOF on stdin. */ 389 debug("Sending eof."); 390 stdin_eof = 1; 391 packet_start(SSH_CMSG_EOF); 392 packet_send(); 393 } else { 394 enter_non_blocking(); 395 396 /* Check for immediate EOF on stdin. */ 397 len = read(fileno(stdin), buf, 1); 398 if (len == 0) { 399 /* 400 * EOF. Record that we have seen it and send 401 * EOF to server. 402 */ 403 debug("Sending eof."); 404 stdin_eof = 1; 405 packet_start(SSH_CMSG_EOF); 406 packet_send(); 407 } else if (len > 0) { 408 /* 409 * Got data. We must store the data in the buffer, 410 * and also process it as an escape character if 411 * appropriate. 412 */ 413 if ((u_char) buf[0] == escape_char1) 414 escape_pending1 = 1; 415 else 416 buffer_append(&stdin_buffer, buf, 1); 417 } 418 leave_non_blocking(); 419 } 420 } 421 422 423 /* 424 * Make packets from buffered stdin data, and buffer them for sending to the 425 * connection. 426 */ 427 428 static void 429 client_make_packets_from_stdin_data(void) 430 { 431 u_int len; 432 433 /* Send buffered stdin data to the server. */ 434 while (buffer_len(&stdin_buffer) > 0 && 435 packet_not_very_much_data_to_write()) { 436 len = buffer_len(&stdin_buffer); 437 /* Keep the packets at reasonable size. */ 438 if (len > packet_get_maxsize()) 439 len = packet_get_maxsize(); 440 packet_start(SSH_CMSG_STDIN_DATA); 441 packet_put_string(buffer_ptr(&stdin_buffer), len); 442 packet_send(); 443 buffer_consume(&stdin_buffer, len); 444 /* If we have a pending EOF, send it now. */ 445 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 446 packet_start(SSH_CMSG_EOF); 447 packet_send(); 448 } 449 } 450 } 451 452 /* 453 * Checks if the client window has changed, and sends a packet about it to 454 * the server if so. The actual change is detected elsewhere (by a software 455 * interrupt on Unix); this just checks the flag and sends a message if 456 * appropriate. 457 */ 458 459 static void 460 client_check_window_change(void) 461 { 462 struct winsize ws; 463 464 if (! received_window_change_signal) 465 return; 466 /** XXX race */ 467 received_window_change_signal = 0; 468 469 debug2("client_check_window_change: changed"); 470 471 if (compat20) { 472 channel_send_window_changes(); 473 } else { 474 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 475 return; 476 packet_start(SSH_CMSG_WINDOW_SIZE); 477 packet_put_int((u_int)ws.ws_row); 478 packet_put_int((u_int)ws.ws_col); 479 packet_put_int((u_int)ws.ws_xpixel); 480 packet_put_int((u_int)ws.ws_ypixel); 481 packet_send(); 482 } 483 } 484 485 static void 486 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 487 { 488 struct global_confirm *gc; 489 490 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 491 return; 492 if (gc->cb != NULL) 493 gc->cb(type, seq, gc->ctx); 494 if (--gc->ref_count <= 0) { 495 TAILQ_REMOVE(&global_confirms, gc, entry); 496 bzero(gc, sizeof(*gc)); 497 xfree(gc); 498 } 499 500 packet_set_alive_timeouts(0); 501 } 502 503 static void 504 server_alive_check(void) 505 { 506 if (packet_inc_alive_timeouts() > options.server_alive_count_max) { 507 logit("Timeout, server not responding."); 508 cleanup_exit(255); 509 } 510 packet_start(SSH2_MSG_GLOBAL_REQUEST); 511 packet_put_cstring("keepalive@openssh.com"); 512 packet_put_char(1); /* boolean: want reply */ 513 packet_send(); 514 /* Insert an empty placeholder to maintain ordering */ 515 client_register_global_confirm(NULL, NULL); 516 } 517 518 /* 519 * Waits until the client can do something (some data becomes available on 520 * one of the file descriptors). 521 */ 522 static void 523 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 524 int *maxfdp, u_int *nallocp, int rekeying) 525 { 526 struct timeval tv, *tvp; 527 int ret; 528 529 /* Add any selections by the channel mechanism. */ 530 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); 531 532 if (!compat20) { 533 /* Read from the connection, unless our buffers are full. */ 534 if (buffer_len(&stdout_buffer) < buffer_high && 535 buffer_len(&stderr_buffer) < buffer_high && 536 channel_not_very_much_buffered_data()) 537 FD_SET(connection_in, *readsetp); 538 /* 539 * Read from stdin, unless we have seen EOF or have very much 540 * buffered data to send to the server. 541 */ 542 if (!stdin_eof && packet_not_very_much_data_to_write()) 543 FD_SET(fileno(stdin), *readsetp); 544 545 /* Select stdout/stderr if have data in buffer. */ 546 if (buffer_len(&stdout_buffer) > 0) 547 FD_SET(fileno(stdout), *writesetp); 548 if (buffer_len(&stderr_buffer) > 0) 549 FD_SET(fileno(stderr), *writesetp); 550 } else { 551 /* channel_prepare_select could have closed the last channel */ 552 if (session_closed && !channel_still_open() && 553 !packet_have_data_to_write()) { 554 /* clear mask since we did not call select() */ 555 memset(*readsetp, 0, *nallocp); 556 memset(*writesetp, 0, *nallocp); 557 return; 558 } else { 559 FD_SET(connection_in, *readsetp); 560 } 561 } 562 563 /* Select server connection if have data to write to the server. */ 564 if (packet_have_data_to_write()) 565 FD_SET(connection_out, *writesetp); 566 567 /* 568 * Wait for something to happen. This will suspend the process until 569 * some selected descriptor can be read, written, or has some other 570 * event pending. 571 */ 572 573 if (options.server_alive_interval == 0 || !compat20) 574 tvp = NULL; 575 else { 576 tv.tv_sec = options.server_alive_interval; 577 tv.tv_usec = 0; 578 tvp = &tv; 579 } 580 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 581 if (ret < 0) { 582 char buf[100]; 583 584 /* 585 * We have to clear the select masks, because we return. 586 * We have to return, because the mainloop checks for the flags 587 * set by the signal handlers. 588 */ 589 memset(*readsetp, 0, *nallocp); 590 memset(*writesetp, 0, *nallocp); 591 592 if (errno == EINTR) 593 return; 594 /* Note: we might still have data in the buffers. */ 595 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 596 buffer_append(&stderr_buffer, buf, strlen(buf)); 597 quit_pending = 1; 598 } else if (ret == 0) 599 server_alive_check(); 600 } 601 602 static void 603 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 604 { 605 /* Flush stdout and stderr buffers. */ 606 if (buffer_len(bout) > 0) 607 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 608 buffer_len(bout)); 609 if (buffer_len(berr) > 0) 610 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 611 buffer_len(berr)); 612 613 leave_raw_mode(force_tty_flag); 614 615 /* 616 * Free (and clear) the buffer to reduce the amount of data that gets 617 * written to swap. 618 */ 619 buffer_free(bin); 620 buffer_free(bout); 621 buffer_free(berr); 622 623 /* Send the suspend signal to the program itself. */ 624 kill(getpid(), SIGTSTP); 625 626 /* Reset window sizes in case they have changed */ 627 received_window_change_signal = 1; 628 629 /* OK, we have been continued by the user. Reinitialize buffers. */ 630 buffer_init(bin); 631 buffer_init(bout); 632 buffer_init(berr); 633 634 enter_raw_mode(force_tty_flag); 635 } 636 637 static void 638 client_process_net_input(fd_set *readset) 639 { 640 int len, cont = 0; 641 char buf[SSH_IOBUFSZ]; 642 643 /* 644 * Read input from the server, and add any such data to the buffer of 645 * the packet subsystem. 646 */ 647 if (FD_ISSET(connection_in, readset)) { 648 /* Read as much as possible. */ 649 len = roaming_read(connection_in, buf, sizeof(buf), &cont); 650 if (len == 0 && cont == 0) { 651 /* 652 * Received EOF. The remote host has closed the 653 * connection. 654 */ 655 snprintf(buf, sizeof buf, 656 "Connection to %.300s closed by remote host.\r\n", 657 host); 658 buffer_append(&stderr_buffer, buf, strlen(buf)); 659 quit_pending = 1; 660 return; 661 } 662 /* 663 * There is a kernel bug on Solaris that causes select to 664 * sometimes wake up even though there is no data available. 665 */ 666 if (len < 0 && 667 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 668 len = 0; 669 670 if (len < 0) { 671 /* 672 * An error has encountered. Perhaps there is a 673 * network problem. 674 */ 675 snprintf(buf, sizeof buf, 676 "Read from remote host %.300s: %.100s\r\n", 677 host, strerror(errno)); 678 buffer_append(&stderr_buffer, buf, strlen(buf)); 679 quit_pending = 1; 680 return; 681 } 682 packet_process_incoming(buf, len); 683 } 684 } 685 686 static void 687 client_status_confirm(int type, Channel *c, void *ctx) 688 { 689 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 690 char errmsg[256]; 691 int tochan; 692 693 /* XXX supress on mux _client_ quietmode */ 694 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 695 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 696 697 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 698 debug2("%s request accepted on channel %d", 699 cr->request_type, c->self); 700 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 701 if (tochan) { 702 snprintf(errmsg, sizeof(errmsg), 703 "%s request failed\r\n", cr->request_type); 704 } else { 705 snprintf(errmsg, sizeof(errmsg), 706 "%s request failed on channel %d", 707 cr->request_type, c->self); 708 } 709 /* If error occurred on primary session channel, then exit */ 710 if (cr->do_close && c->self == session_ident) 711 fatal("%s", errmsg); 712 /* If error occurred on mux client, append to their stderr */ 713 if (tochan) 714 buffer_append(&c->extended, errmsg, strlen(errmsg)); 715 else 716 error("%s", errmsg); 717 if (cr->do_close) { 718 chan_read_failed(c); 719 chan_write_failed(c); 720 } 721 } 722 xfree(cr); 723 } 724 725 static void 726 client_abandon_status_confirm(Channel *c, void *ctx) 727 { 728 xfree(ctx); 729 } 730 731 static void 732 client_expect_confirm(int id, const char *request, int do_close) 733 { 734 struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); 735 736 cr->request_type = request; 737 cr->do_close = do_close; 738 739 channel_register_status_confirm(id, client_status_confirm, 740 client_abandon_status_confirm, cr); 741 } 742 743 void 744 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 745 { 746 struct global_confirm *gc, *last_gc; 747 748 /* Coalesce identical callbacks */ 749 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 750 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 751 if (++last_gc->ref_count >= INT_MAX) 752 fatal("%s: last_gc->ref_count = %d", 753 __func__, last_gc->ref_count); 754 return; 755 } 756 757 gc = xmalloc(sizeof(*gc)); 758 gc->cb = cb; 759 gc->ctx = ctx; 760 gc->ref_count = 1; 761 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 762 } 763 764 static void 765 process_cmdline(void) 766 { 767 void (*handler)(int); 768 char *s, *cmd, *cancel_host; 769 int delete = 0; 770 int local = 0, remote = 0, dynamic = 0; 771 int cancel_port; 772 Forward fwd; 773 774 bzero(&fwd, sizeof(fwd)); 775 fwd.listen_host = fwd.connect_host = NULL; 776 777 leave_raw_mode(force_tty_flag); 778 handler = signal(SIGINT, SIG_IGN); 779 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 780 if (s == NULL) 781 goto out; 782 while (isspace(*s)) 783 s++; 784 if (*s == '-') 785 s++; /* Skip cmdline '-', if any */ 786 if (*s == '\0') 787 goto out; 788 789 if (*s == 'h' || *s == 'H' || *s == '?') { 790 logit("Commands:"); 791 logit(" -L[bind_address:]port:host:hostport " 792 "Request local forward"); 793 logit(" -R[bind_address:]port:host:hostport " 794 "Request remote forward"); 795 logit(" -D[bind_address:]port " 796 "Request dynamic forward"); 797 logit(" -KR[bind_address:]port " 798 "Cancel remote forward"); 799 if (!options.permit_local_command) 800 goto out; 801 logit(" !args " 802 "Execute local command"); 803 goto out; 804 } 805 806 if (*s == '!' && options.permit_local_command) { 807 s++; 808 ssh_local_cmd(s); 809 goto out; 810 } 811 812 if (*s == 'K') { 813 delete = 1; 814 s++; 815 } 816 if (*s == 'L') 817 local = 1; 818 else if (*s == 'R') 819 remote = 1; 820 else if (*s == 'D') 821 dynamic = 1; 822 else { 823 logit("Invalid command."); 824 goto out; 825 } 826 827 if ((local || dynamic) && delete) { 828 logit("Not supported."); 829 goto out; 830 } 831 if (remote && delete && !compat20) { 832 logit("Not supported for SSH protocol version 1."); 833 goto out; 834 } 835 836 while (isspace(*++s)) 837 ; 838 839 /* XXX update list of forwards in options */ 840 if (delete) { 841 cancel_port = 0; 842 cancel_host = hpdelim(&s); /* may be NULL */ 843 if (s != NULL) { 844 cancel_port = a2port(s); 845 cancel_host = cleanhostname(cancel_host); 846 } else { 847 cancel_port = a2port(cancel_host); 848 cancel_host = NULL; 849 } 850 if (cancel_port <= 0) { 851 logit("Bad forwarding close port"); 852 goto out; 853 } 854 channel_request_rforward_cancel(cancel_host, cancel_port); 855 } else { 856 if (!parse_forward(&fwd, s, dynamic, remote)) { 857 logit("Bad forwarding specification."); 858 goto out; 859 } 860 if (local || dynamic) { 861 if (channel_setup_local_fwd_listener(fwd.listen_host, 862 fwd.listen_port, fwd.connect_host, 863 fwd.connect_port, options.gateway_ports) < 0) { 864 logit("Port forwarding failed."); 865 goto out; 866 } 867 } else { 868 if (channel_request_remote_forwarding(fwd.listen_host, 869 fwd.listen_port, fwd.connect_host, 870 fwd.connect_port) < 0) { 871 logit("Port forwarding failed."); 872 goto out; 873 } 874 } 875 876 logit("Forwarding port."); 877 } 878 879 out: 880 signal(SIGINT, handler); 881 enter_raw_mode(force_tty_flag); 882 if (cmd) 883 xfree(cmd); 884 if (fwd.listen_host != NULL) 885 xfree(fwd.listen_host); 886 if (fwd.connect_host != NULL) 887 xfree(fwd.connect_host); 888 } 889 890 /* 891 * Process the characters one by one, call with c==NULL for proto1 case. 892 */ 893 static int 894 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 895 char *buf, int len) 896 { 897 char string[1024]; 898 pid_t pid; 899 int bytes = 0; 900 u_int i; 901 u_char ch; 902 char *s; 903 int *escape_pendingp, escape_char; 904 struct escape_filter_ctx *efc; 905 906 if (c == NULL) { 907 escape_pendingp = &escape_pending1; 908 escape_char = escape_char1; 909 } else { 910 if (c->filter_ctx == NULL) 911 return 0; 912 efc = (struct escape_filter_ctx *)c->filter_ctx; 913 escape_pendingp = &efc->escape_pending; 914 escape_char = efc->escape_char; 915 } 916 917 if (len <= 0) 918 return (0); 919 920 for (i = 0; i < (u_int)len; i++) { 921 /* Get one character at a time. */ 922 ch = buf[i]; 923 924 if (*escape_pendingp) { 925 /* We have previously seen an escape character. */ 926 /* Clear the flag now. */ 927 *escape_pendingp = 0; 928 929 /* Process the escaped character. */ 930 switch (ch) { 931 case '.': 932 /* Terminate the connection. */ 933 snprintf(string, sizeof string, "%c.\r\n", 934 escape_char); 935 buffer_append(berr, string, strlen(string)); 936 937 if (c && c->ctl_chan != -1) { 938 chan_read_failed(c); 939 chan_write_failed(c); 940 return 0; 941 } else 942 quit_pending = 1; 943 return -1; 944 945 case 'Z' - 64: 946 /* XXX support this for mux clients */ 947 if (c && c->ctl_chan != -1) { 948 noescape: 949 snprintf(string, sizeof string, 950 "%c%c escape not available to " 951 "multiplexed sessions\r\n", 952 escape_char, ch); 953 buffer_append(berr, string, 954 strlen(string)); 955 continue; 956 } 957 /* Suspend the program. Inform the user */ 958 snprintf(string, sizeof string, 959 "%c^Z [suspend ssh]\r\n", escape_char); 960 buffer_append(berr, string, strlen(string)); 961 962 /* Restore terminal modes and suspend. */ 963 client_suspend_self(bin, bout, berr); 964 965 /* We have been continued. */ 966 continue; 967 968 case 'B': 969 if (compat20) { 970 snprintf(string, sizeof string, 971 "%cB\r\n", escape_char); 972 buffer_append(berr, string, 973 strlen(string)); 974 channel_request_start(session_ident, 975 "break", 0); 976 packet_put_int(1000); 977 packet_send(); 978 } 979 continue; 980 981 case 'R': 982 if (compat20) { 983 if (datafellows & SSH_BUG_NOREKEY) 984 logit("Server does not " 985 "support re-keying"); 986 else 987 need_rekeying = 1; 988 } 989 continue; 990 991 case '&': 992 if (c && c->ctl_chan != -1) 993 goto noescape; 994 /* 995 * Detach the program (continue to serve 996 * connections, but put in background and no 997 * more new connections). 998 */ 999 /* Restore tty modes. */ 1000 leave_raw_mode(force_tty_flag); 1001 1002 /* Stop listening for new connections. */ 1003 channel_stop_listening(); 1004 1005 snprintf(string, sizeof string, 1006 "%c& [backgrounded]\n", escape_char); 1007 buffer_append(berr, string, strlen(string)); 1008 1009 /* Fork into background. */ 1010 pid = fork(); 1011 if (pid < 0) { 1012 error("fork: %.100s", strerror(errno)); 1013 continue; 1014 } 1015 if (pid != 0) { /* This is the parent. */ 1016 /* The parent just exits. */ 1017 exit(0); 1018 } 1019 /* The child continues serving connections. */ 1020 if (compat20) { 1021 buffer_append(bin, "\004", 1); 1022 /* fake EOF on stdin */ 1023 return -1; 1024 } else if (!stdin_eof) { 1025 /* 1026 * Sending SSH_CMSG_EOF alone does not 1027 * always appear to be enough. So we 1028 * try to send an EOF character first. 1029 */ 1030 packet_start(SSH_CMSG_STDIN_DATA); 1031 packet_put_string("\004", 1); 1032 packet_send(); 1033 /* Close stdin. */ 1034 stdin_eof = 1; 1035 if (buffer_len(bin) == 0) { 1036 packet_start(SSH_CMSG_EOF); 1037 packet_send(); 1038 } 1039 } 1040 continue; 1041 1042 case '?': 1043 if (c && c->ctl_chan != -1) { 1044 snprintf(string, sizeof string, 1045 "%c?\r\n\ 1046 Supported escape sequences:\r\n\ 1047 %c. - terminate session\r\n\ 1048 %cB - send a BREAK to the remote system\r\n\ 1049 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1050 %c# - list forwarded connections\r\n\ 1051 %c? - this message\r\n\ 1052 %c%c - send the escape character by typing it twice\r\n\ 1053 (Note that escapes are only recognized immediately after newline.)\r\n", 1054 escape_char, escape_char, 1055 escape_char, escape_char, 1056 escape_char, escape_char, 1057 escape_char, escape_char); 1058 } else { 1059 snprintf(string, sizeof string, 1060 "%c?\r\n\ 1061 Supported escape sequences:\r\n\ 1062 %c. - terminate connection (and any multiplexed sessions)\r\n\ 1063 %cB - send a BREAK to the remote system\r\n\ 1064 %cC - open a command line\r\n\ 1065 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1066 %c^Z - suspend ssh\r\n\ 1067 %c# - list forwarded connections\r\n\ 1068 %c& - background ssh (when waiting for connections to terminate)\r\n\ 1069 %c? - this message\r\n\ 1070 %c%c - send the escape character by typing it twice\r\n\ 1071 (Note that escapes are only recognized immediately after newline.)\r\n", 1072 escape_char, escape_char, 1073 escape_char, escape_char, 1074 escape_char, escape_char, 1075 escape_char, escape_char, 1076 escape_char, escape_char, 1077 escape_char); 1078 } 1079 buffer_append(berr, string, strlen(string)); 1080 continue; 1081 1082 case '#': 1083 snprintf(string, sizeof string, "%c#\r\n", 1084 escape_char); 1085 buffer_append(berr, string, strlen(string)); 1086 s = channel_open_message(); 1087 buffer_append(berr, s, strlen(s)); 1088 xfree(s); 1089 continue; 1090 1091 case 'C': 1092 if (c && c->ctl_chan != -1) 1093 goto noescape; 1094 process_cmdline(); 1095 continue; 1096 1097 default: 1098 if (ch != escape_char) { 1099 buffer_put_char(bin, escape_char); 1100 bytes++; 1101 } 1102 /* Escaped characters fall through here */ 1103 break; 1104 } 1105 } else { 1106 /* 1107 * The previous character was not an escape char. 1108 * Check if this is an escape. 1109 */ 1110 if (last_was_cr && ch == escape_char) { 1111 /* 1112 * It is. Set the flag and continue to 1113 * next character. 1114 */ 1115 *escape_pendingp = 1; 1116 continue; 1117 } 1118 } 1119 1120 /* 1121 * Normal character. Record whether it was a newline, 1122 * and append it to the buffer. 1123 */ 1124 last_was_cr = (ch == '\r' || ch == '\n'); 1125 buffer_put_char(bin, ch); 1126 bytes++; 1127 } 1128 return bytes; 1129 } 1130 1131 static void 1132 client_process_input(fd_set *readset) 1133 { 1134 int len; 1135 char buf[SSH_IOBUFSZ]; 1136 1137 /* Read input from stdin. */ 1138 if (FD_ISSET(fileno(stdin), readset)) { 1139 /* Read as much as possible. */ 1140 len = read(fileno(stdin), buf, sizeof(buf)); 1141 if (len < 0 && 1142 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1143 return; /* we'll try again later */ 1144 if (len <= 0) { 1145 /* 1146 * Received EOF or error. They are treated 1147 * similarly, except that an error message is printed 1148 * if it was an error condition. 1149 */ 1150 if (len < 0) { 1151 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1152 strerror(errno)); 1153 buffer_append(&stderr_buffer, buf, strlen(buf)); 1154 } 1155 /* Mark that we have seen EOF. */ 1156 stdin_eof = 1; 1157 /* 1158 * Send an EOF message to the server unless there is 1159 * data in the buffer. If there is data in the 1160 * buffer, no message will be sent now. Code 1161 * elsewhere will send the EOF when the buffer 1162 * becomes empty if stdin_eof is set. 1163 */ 1164 if (buffer_len(&stdin_buffer) == 0) { 1165 packet_start(SSH_CMSG_EOF); 1166 packet_send(); 1167 } 1168 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1169 /* 1170 * Normal successful read, and no escape character. 1171 * Just append the data to buffer. 1172 */ 1173 buffer_append(&stdin_buffer, buf, len); 1174 } else { 1175 /* 1176 * Normal, successful read. But we have an escape 1177 * character and have to process the characters one 1178 * by one. 1179 */ 1180 if (process_escapes(NULL, &stdin_buffer, 1181 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1182 return; 1183 } 1184 } 1185 } 1186 1187 static void 1188 client_process_output(fd_set *writeset) 1189 { 1190 int len; 1191 char buf[100]; 1192 1193 /* Write buffered output to stdout. */ 1194 if (FD_ISSET(fileno(stdout), writeset)) { 1195 /* Write as much data as possible. */ 1196 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1197 buffer_len(&stdout_buffer)); 1198 if (len <= 0) { 1199 if (errno == EINTR || errno == EAGAIN || 1200 errno == EWOULDBLOCK) 1201 len = 0; 1202 else { 1203 /* 1204 * An error or EOF was encountered. Put an 1205 * error message to stderr buffer. 1206 */ 1207 snprintf(buf, sizeof buf, 1208 "write stdout: %.50s\r\n", strerror(errno)); 1209 buffer_append(&stderr_buffer, buf, strlen(buf)); 1210 quit_pending = 1; 1211 return; 1212 } 1213 } 1214 /* Consume printed data from the buffer. */ 1215 buffer_consume(&stdout_buffer, len); 1216 } 1217 /* Write buffered output to stderr. */ 1218 if (FD_ISSET(fileno(stderr), writeset)) { 1219 /* Write as much data as possible. */ 1220 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1221 buffer_len(&stderr_buffer)); 1222 if (len <= 0) { 1223 if (errno == EINTR || errno == EAGAIN || 1224 errno == EWOULDBLOCK) 1225 len = 0; 1226 else { 1227 /* 1228 * EOF or error, but can't even print 1229 * error message. 1230 */ 1231 quit_pending = 1; 1232 return; 1233 } 1234 } 1235 /* Consume printed characters from the buffer. */ 1236 buffer_consume(&stderr_buffer, len); 1237 } 1238 } 1239 1240 /* 1241 * Get packets from the connection input buffer, and process them as long as 1242 * there are packets available. 1243 * 1244 * Any unknown packets received during the actual 1245 * session cause the session to terminate. This is 1246 * intended to make debugging easier since no 1247 * confirmations are sent. Any compatible protocol 1248 * extensions must be negotiated during the 1249 * preparatory phase. 1250 */ 1251 1252 static void 1253 client_process_buffered_input_packets(void) 1254 { 1255 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1256 compat20 ? xxx_kex : NULL); 1257 } 1258 1259 /* scan buf[] for '~' before sending data to the peer */ 1260 1261 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1262 void * 1263 client_new_escape_filter_ctx(int escape_char) 1264 { 1265 struct escape_filter_ctx *ret; 1266 1267 ret = xmalloc(sizeof(*ret)); 1268 ret->escape_pending = 0; 1269 ret->escape_char = escape_char; 1270 return (void *)ret; 1271 } 1272 1273 /* Free the escape filter context on channel free */ 1274 void 1275 client_filter_cleanup(int cid, void *ctx) 1276 { 1277 xfree(ctx); 1278 } 1279 1280 int 1281 client_simple_escape_filter(Channel *c, char *buf, int len) 1282 { 1283 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1284 return 0; 1285 1286 return process_escapes(c, &c->input, &c->output, &c->extended, 1287 buf, len); 1288 } 1289 1290 static void 1291 client_channel_closed(int id, void *arg) 1292 { 1293 channel_cancel_cleanup(id); 1294 session_closed = 1; 1295 leave_raw_mode(force_tty_flag); 1296 } 1297 1298 /* 1299 * Implements the interactive session with the server. This is called after 1300 * the user has been authenticated, and a command has been started on the 1301 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1302 * used as an escape character for terminating or suspending the session. 1303 */ 1304 1305 int 1306 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1307 { 1308 fd_set *readset = NULL, *writeset = NULL; 1309 double start_time, total_time; 1310 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1311 u_int64_t ibytes, obytes; 1312 u_int nalloc = 0; 1313 char buf[100]; 1314 1315 debug("Entering interactive session."); 1316 1317 start_time = get_current_time(); 1318 1319 /* Initialize variables. */ 1320 escape_pending1 = 0; 1321 last_was_cr = 1; 1322 exit_status = -1; 1323 stdin_eof = 0; 1324 buffer_high = 64 * 1024; 1325 connection_in = packet_get_connection_in(); 1326 connection_out = packet_get_connection_out(); 1327 max_fd = MAX(connection_in, connection_out); 1328 1329 if (!compat20) { 1330 /* enable nonblocking unless tty */ 1331 if (!isatty(fileno(stdin))) 1332 set_nonblock(fileno(stdin)); 1333 if (!isatty(fileno(stdout))) 1334 set_nonblock(fileno(stdout)); 1335 if (!isatty(fileno(stderr))) 1336 set_nonblock(fileno(stderr)); 1337 max_fd = MAX(max_fd, fileno(stdin)); 1338 max_fd = MAX(max_fd, fileno(stdout)); 1339 max_fd = MAX(max_fd, fileno(stderr)); 1340 } 1341 quit_pending = 0; 1342 escape_char1 = escape_char_arg; 1343 1344 /* Initialize buffers. */ 1345 buffer_init(&stdin_buffer); 1346 buffer_init(&stdout_buffer); 1347 buffer_init(&stderr_buffer); 1348 1349 client_init_dispatch(); 1350 1351 /* 1352 * Set signal handlers, (e.g. to restore non-blocking mode) 1353 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1354 */ 1355 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1356 signal(SIGHUP, signal_handler); 1357 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1358 signal(SIGINT, signal_handler); 1359 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1360 signal(SIGQUIT, signal_handler); 1361 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1362 signal(SIGTERM, signal_handler); 1363 signal(SIGWINCH, window_change_handler); 1364 1365 if (have_pty) 1366 enter_raw_mode(force_tty_flag); 1367 1368 if (compat20) { 1369 session_ident = ssh2_chan_id; 1370 if (escape_char_arg != SSH_ESCAPECHAR_NONE) 1371 channel_register_filter(session_ident, 1372 client_simple_escape_filter, NULL, 1373 client_filter_cleanup, 1374 client_new_escape_filter_ctx(escape_char_arg)); 1375 if (session_ident != -1) 1376 channel_register_cleanup(session_ident, 1377 client_channel_closed, 0); 1378 } else { 1379 /* Check if we should immediately send eof on stdin. */ 1380 client_check_initial_eof_on_stdin(); 1381 } 1382 1383 /* Main loop of the client for the interactive session mode. */ 1384 while (!quit_pending) { 1385 1386 /* Process buffered packets sent by the server. */ 1387 client_process_buffered_input_packets(); 1388 1389 if (compat20 && session_closed && !channel_still_open()) 1390 break; 1391 1392 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1393 1394 if (rekeying) { 1395 debug("rekeying in progress"); 1396 } else { 1397 /* 1398 * Make packets of buffered stdin data, and buffer 1399 * them for sending to the server. 1400 */ 1401 if (!compat20) 1402 client_make_packets_from_stdin_data(); 1403 1404 /* 1405 * Make packets from buffered channel data, and 1406 * enqueue them for sending to the server. 1407 */ 1408 if (packet_not_very_much_data_to_write()) 1409 channel_output_poll(); 1410 1411 /* 1412 * Check if the window size has changed, and buffer a 1413 * message about it to the server if so. 1414 */ 1415 client_check_window_change(); 1416 1417 if (quit_pending) 1418 break; 1419 } 1420 /* 1421 * Wait until we have something to do (something becomes 1422 * available on one of the descriptors). 1423 */ 1424 max_fd2 = max_fd; 1425 client_wait_until_can_do_something(&readset, &writeset, 1426 &max_fd2, &nalloc, rekeying); 1427 1428 if (quit_pending) 1429 break; 1430 1431 /* Do channel operations unless rekeying in progress. */ 1432 if (!rekeying) { 1433 channel_after_select(readset, writeset); 1434 if (need_rekeying || packet_need_rekeying()) { 1435 debug("need rekeying"); 1436 xxx_kex->done = 0; 1437 kex_send_kexinit(xxx_kex); 1438 need_rekeying = 0; 1439 } 1440 } 1441 1442 /* Buffer input from the connection. */ 1443 client_process_net_input(readset); 1444 1445 if (quit_pending) 1446 break; 1447 1448 if (!compat20) { 1449 /* Buffer data from stdin */ 1450 client_process_input(readset); 1451 /* 1452 * Process output to stdout and stderr. Output to 1453 * the connection is processed elsewhere (above). 1454 */ 1455 client_process_output(writeset); 1456 } 1457 1458 if (session_resumed) { 1459 connection_in = packet_get_connection_in(); 1460 connection_out = packet_get_connection_out(); 1461 max_fd = MAX(max_fd, connection_out); 1462 max_fd = MAX(max_fd, connection_in); 1463 session_resumed = 0; 1464 } 1465 1466 /* 1467 * Send as much buffered packet data as possible to the 1468 * sender. 1469 */ 1470 if (FD_ISSET(connection_out, writeset)) 1471 packet_write_poll(); 1472 } 1473 if (readset) 1474 xfree(readset); 1475 if (writeset) 1476 xfree(writeset); 1477 1478 /* Terminate the session. */ 1479 1480 /* Stop watching for window change. */ 1481 signal(SIGWINCH, SIG_DFL); 1482 1483 if (compat20) { 1484 packet_start(SSH2_MSG_DISCONNECT); 1485 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION); 1486 packet_put_cstring("disconnected by user"); 1487 packet_put_cstring(""); /* language tag */ 1488 packet_send(); 1489 packet_write_wait(); 1490 } 1491 1492 channel_free_all(); 1493 1494 if (have_pty) 1495 leave_raw_mode(force_tty_flag); 1496 1497 /* restore blocking io */ 1498 if (!isatty(fileno(stdin))) 1499 unset_nonblock(fileno(stdin)); 1500 if (!isatty(fileno(stdout))) 1501 unset_nonblock(fileno(stdout)); 1502 if (!isatty(fileno(stderr))) 1503 unset_nonblock(fileno(stderr)); 1504 1505 /* 1506 * If there was no shell or command requested, there will be no remote 1507 * exit status to be returned. In that case, clear error code if the 1508 * connection was deliberately terminated at this end. 1509 */ 1510 if (no_shell_flag && received_signal == SIGTERM) { 1511 received_signal = 0; 1512 exit_status = 0; 1513 } 1514 1515 if (received_signal) 1516 fatal("Killed by signal %d.", (int) received_signal); 1517 1518 /* 1519 * In interactive mode (with pseudo tty) display a message indicating 1520 * that the connection has been closed. 1521 */ 1522 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1523 snprintf(buf, sizeof buf, 1524 "Connection to %.64s closed.\r\n", host); 1525 buffer_append(&stderr_buffer, buf, strlen(buf)); 1526 } 1527 1528 /* Output any buffered data for stdout. */ 1529 while (buffer_len(&stdout_buffer) > 0) { 1530 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1531 buffer_len(&stdout_buffer)); 1532 if (len <= 0) { 1533 error("Write failed flushing stdout buffer."); 1534 break; 1535 } 1536 buffer_consume(&stdout_buffer, len); 1537 } 1538 1539 /* Output any buffered data for stderr. */ 1540 while (buffer_len(&stderr_buffer) > 0) { 1541 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1542 buffer_len(&stderr_buffer)); 1543 if (len <= 0) { 1544 error("Write failed flushing stderr buffer."); 1545 break; 1546 } 1547 buffer_consume(&stderr_buffer, len); 1548 } 1549 1550 /* Clear and free any buffers. */ 1551 memset(buf, 0, sizeof(buf)); 1552 buffer_free(&stdin_buffer); 1553 buffer_free(&stdout_buffer); 1554 buffer_free(&stderr_buffer); 1555 1556 /* Report bytes transferred, and transfer rates. */ 1557 total_time = get_current_time() - start_time; 1558 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1559 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1560 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1561 obytes, ibytes, total_time); 1562 if (total_time > 0) 1563 verbose("Bytes per second: sent %.1f, received %.1f", 1564 obytes / total_time, ibytes / total_time); 1565 /* Return the exit status of the program. */ 1566 debug("Exit status %d", exit_status); 1567 return exit_status; 1568 } 1569 1570 /*********/ 1571 1572 static void 1573 client_input_stdout_data(int type, u_int32_t seq, void *ctxt) 1574 { 1575 u_int data_len; 1576 char *data = packet_get_string(&data_len); 1577 packet_check_eom(); 1578 buffer_append(&stdout_buffer, data, data_len); 1579 memset(data, 0, data_len); 1580 xfree(data); 1581 } 1582 static void 1583 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1584 { 1585 u_int data_len; 1586 char *data = packet_get_string(&data_len); 1587 packet_check_eom(); 1588 buffer_append(&stderr_buffer, data, data_len); 1589 memset(data, 0, data_len); 1590 xfree(data); 1591 } 1592 static void 1593 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1594 { 1595 exit_status = packet_get_int(); 1596 packet_check_eom(); 1597 /* Acknowledge the exit. */ 1598 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1599 packet_send(); 1600 /* 1601 * Must wait for packet to be sent since we are 1602 * exiting the loop. 1603 */ 1604 packet_write_wait(); 1605 /* Flag that we want to exit. */ 1606 quit_pending = 1; 1607 } 1608 static void 1609 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1610 { 1611 Channel *c = NULL; 1612 int remote_id, sock; 1613 1614 /* Read the remote channel number from the message. */ 1615 remote_id = packet_get_int(); 1616 packet_check_eom(); 1617 1618 /* 1619 * Get a connection to the local authentication agent (this may again 1620 * get forwarded). 1621 */ 1622 sock = ssh_get_authentication_socket(); 1623 1624 /* 1625 * If we could not connect the agent, send an error message back to 1626 * the server. This should never happen unless the agent dies, 1627 * because authentication forwarding is only enabled if we have an 1628 * agent. 1629 */ 1630 if (sock >= 0) { 1631 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1632 -1, 0, 0, 0, "authentication agent connection", 1); 1633 c->remote_id = remote_id; 1634 c->force_drain = 1; 1635 } 1636 if (c == NULL) { 1637 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1638 packet_put_int(remote_id); 1639 } else { 1640 /* Send a confirmation to the remote host. */ 1641 debug("Forwarding authentication connection."); 1642 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1643 packet_put_int(remote_id); 1644 packet_put_int(c->self); 1645 } 1646 packet_send(); 1647 } 1648 1649 static Channel * 1650 client_request_forwarded_tcpip(const char *request_type, int rchan) 1651 { 1652 Channel *c = NULL; 1653 char *listen_address, *originator_address; 1654 u_short listen_port, originator_port; 1655 1656 /* Get rest of the packet */ 1657 listen_address = packet_get_string(NULL); 1658 listen_port = packet_get_int(); 1659 originator_address = packet_get_string(NULL); 1660 originator_port = packet_get_int(); 1661 packet_check_eom(); 1662 1663 debug("client_request_forwarded_tcpip: listen %s port %d, " 1664 "originator %s port %d", listen_address, listen_port, 1665 originator_address, originator_port); 1666 1667 c = channel_connect_by_listen_address(listen_port, 1668 "forwarded-tcpip", originator_address); 1669 1670 xfree(originator_address); 1671 xfree(listen_address); 1672 return c; 1673 } 1674 1675 static Channel * 1676 client_request_x11(const char *request_type, int rchan) 1677 { 1678 Channel *c = NULL; 1679 char *originator; 1680 u_short originator_port; 1681 int sock; 1682 1683 if (!options.forward_x11) { 1684 error("Warning: ssh server tried X11 forwarding."); 1685 error("Warning: this is probably a break-in attempt by a " 1686 "malicious server."); 1687 return NULL; 1688 } 1689 originator = packet_get_string(NULL); 1690 if (datafellows & SSH_BUG_X11FWD) { 1691 debug2("buggy server: x11 request w/o originator_port"); 1692 originator_port = 0; 1693 } else { 1694 originator_port = packet_get_int(); 1695 } 1696 packet_check_eom(); 1697 /* XXX check permission */ 1698 debug("client_request_x11: request from %s %d", originator, 1699 originator_port); 1700 xfree(originator); 1701 sock = x11_connect_display(); 1702 if (sock < 0) 1703 return NULL; 1704 c = channel_new("x11", 1705 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1706 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1707 c->force_drain = 1; 1708 return c; 1709 } 1710 1711 static Channel * 1712 client_request_agent(const char *request_type, int rchan) 1713 { 1714 Channel *c = NULL; 1715 int sock; 1716 1717 if (!options.forward_agent) { 1718 error("Warning: ssh server tried agent forwarding."); 1719 error("Warning: this is probably a break-in attempt by a " 1720 "malicious server."); 1721 return NULL; 1722 } 1723 sock = ssh_get_authentication_socket(); 1724 if (sock < 0) 1725 return NULL; 1726 c = channel_new("authentication agent connection", 1727 SSH_CHANNEL_OPEN, sock, sock, -1, 1728 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1729 "authentication agent connection", 1); 1730 c->force_drain = 1; 1731 return c; 1732 } 1733 1734 int 1735 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1736 { 1737 Channel *c; 1738 int fd; 1739 1740 if (tun_mode == SSH_TUNMODE_NO) 1741 return 0; 1742 1743 if (!compat20) { 1744 error("Tunnel forwarding is not supported for protocol 1"); 1745 return -1; 1746 } 1747 1748 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1749 1750 /* Open local tunnel device */ 1751 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1752 error("Tunnel device open failed."); 1753 return -1; 1754 } 1755 1756 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1757 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1758 c->datagram = 1; 1759 1760 #if defined(SSH_TUN_FILTER) 1761 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1762 channel_register_filter(c->self, sys_tun_infilter, 1763 sys_tun_outfilter, NULL, NULL); 1764 #endif 1765 1766 packet_start(SSH2_MSG_CHANNEL_OPEN); 1767 packet_put_cstring("tun@openssh.com"); 1768 packet_put_int(c->self); 1769 packet_put_int(c->local_window_max); 1770 packet_put_int(c->local_maxpacket); 1771 packet_put_int(tun_mode); 1772 packet_put_int(remote_tun); 1773 packet_send(); 1774 1775 return 0; 1776 } 1777 1778 /* XXXX move to generic input handler */ 1779 static void 1780 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1781 { 1782 Channel *c = NULL; 1783 char *ctype; 1784 int rchan; 1785 u_int rmaxpack, rwindow, len; 1786 1787 ctype = packet_get_string(&len); 1788 rchan = packet_get_int(); 1789 rwindow = packet_get_int(); 1790 rmaxpack = packet_get_int(); 1791 1792 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1793 ctype, rchan, rwindow, rmaxpack); 1794 1795 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1796 c = client_request_forwarded_tcpip(ctype, rchan); 1797 } else if (strcmp(ctype, "x11") == 0) { 1798 c = client_request_x11(ctype, rchan); 1799 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1800 c = client_request_agent(ctype, rchan); 1801 } 1802 /* XXX duplicate : */ 1803 if (c != NULL) { 1804 debug("confirm %s", ctype); 1805 c->remote_id = rchan; 1806 c->remote_window = rwindow; 1807 c->remote_maxpacket = rmaxpack; 1808 if (c->type != SSH_CHANNEL_CONNECTING) { 1809 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 1810 packet_put_int(c->remote_id); 1811 packet_put_int(c->self); 1812 packet_put_int(c->local_window); 1813 packet_put_int(c->local_maxpacket); 1814 packet_send(); 1815 } 1816 } else { 1817 debug("failure %s", ctype); 1818 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 1819 packet_put_int(rchan); 1820 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 1821 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 1822 packet_put_cstring("open failed"); 1823 packet_put_cstring(""); 1824 } 1825 packet_send(); 1826 } 1827 xfree(ctype); 1828 } 1829 static void 1830 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 1831 { 1832 Channel *c = NULL; 1833 int exitval, id, reply, success = 0; 1834 char *rtype; 1835 1836 id = packet_get_int(); 1837 rtype = packet_get_string(NULL); 1838 reply = packet_get_char(); 1839 1840 debug("client_input_channel_req: channel %d rtype %s reply %d", 1841 id, rtype, reply); 1842 1843 if (id == -1) { 1844 error("client_input_channel_req: request for channel -1"); 1845 } else if ((c = channel_lookup(id)) == NULL) { 1846 error("client_input_channel_req: channel %d: " 1847 "unknown channel", id); 1848 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1849 packet_check_eom(); 1850 chan_rcvd_eow(c); 1851 } else if (strcmp(rtype, "exit-status") == 0) { 1852 exitval = packet_get_int(); 1853 if (c->ctl_chan != -1) { 1854 mux_exit_message(c, exitval); 1855 success = 1; 1856 } else if (id == session_ident) { 1857 /* Record exit value of local session */ 1858 success = 1; 1859 exit_status = exitval; 1860 } else { 1861 /* Probably for a mux channel that has already closed */ 1862 debug("%s: no sink for exit-status on channel %d", 1863 __func__, id); 1864 } 1865 packet_check_eom(); 1866 } 1867 if (reply) { 1868 packet_start(success ? 1869 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 1870 packet_put_int(c->remote_id); 1871 packet_send(); 1872 } 1873 xfree(rtype); 1874 } 1875 static void 1876 client_input_global_request(int type, u_int32_t seq, void *ctxt) 1877 { 1878 char *rtype; 1879 int want_reply; 1880 int success = 0; 1881 1882 rtype = packet_get_string(NULL); 1883 want_reply = packet_get_char(); 1884 debug("client_input_global_request: rtype %s want_reply %d", 1885 rtype, want_reply); 1886 if (want_reply) { 1887 packet_start(success ? 1888 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 1889 packet_send(); 1890 packet_write_wait(); 1891 } 1892 xfree(rtype); 1893 } 1894 1895 void 1896 client_session2_setup(int id, int want_tty, int want_subsystem, 1897 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 1898 { 1899 int len; 1900 Channel *c = NULL; 1901 1902 debug2("%s: id %d", __func__, id); 1903 1904 if ((c = channel_lookup(id)) == NULL) 1905 fatal("client_session2_setup: channel %d: unknown channel", id); 1906 1907 if (want_tty) { 1908 struct winsize ws; 1909 1910 /* Store window size in the packet. */ 1911 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 1912 memset(&ws, 0, sizeof(ws)); 1913 1914 channel_request_start(id, "pty-req", 1); 1915 client_expect_confirm(id, "PTY allocation", 0); 1916 packet_put_cstring(term != NULL ? term : ""); 1917 packet_put_int((u_int)ws.ws_col); 1918 packet_put_int((u_int)ws.ws_row); 1919 packet_put_int((u_int)ws.ws_xpixel); 1920 packet_put_int((u_int)ws.ws_ypixel); 1921 if (tiop == NULL) 1922 tiop = get_saved_tio(); 1923 tty_make_modes(-1, tiop); 1924 packet_send(); 1925 /* XXX wait for reply */ 1926 c->client_tty = 1; 1927 } 1928 1929 /* Transfer any environment variables from client to server */ 1930 if (options.num_send_env != 0 && env != NULL) { 1931 int i, j, matched; 1932 char *name, *val; 1933 1934 debug("Sending environment."); 1935 for (i = 0; env[i] != NULL; i++) { 1936 /* Split */ 1937 name = xstrdup(env[i]); 1938 if ((val = strchr(name, '=')) == NULL) { 1939 xfree(name); 1940 continue; 1941 } 1942 *val++ = '\0'; 1943 1944 matched = 0; 1945 for (j = 0; j < options.num_send_env; j++) { 1946 if (match_pattern(name, options.send_env[j])) { 1947 matched = 1; 1948 break; 1949 } 1950 } 1951 if (!matched) { 1952 debug3("Ignored env %s", name); 1953 xfree(name); 1954 continue; 1955 } 1956 1957 debug("Sending env %s = %s", name, val); 1958 channel_request_start(id, "env", 0); 1959 packet_put_cstring(name); 1960 packet_put_cstring(val); 1961 packet_send(); 1962 xfree(name); 1963 } 1964 } 1965 1966 len = buffer_len(cmd); 1967 if (len > 0) { 1968 if (len > 900) 1969 len = 900; 1970 if (want_subsystem) { 1971 debug("Sending subsystem: %.*s", 1972 len, (u_char*)buffer_ptr(cmd)); 1973 channel_request_start(id, "subsystem", 1); 1974 client_expect_confirm(id, "subsystem", 1); 1975 } else { 1976 debug("Sending command: %.*s", 1977 len, (u_char*)buffer_ptr(cmd)); 1978 channel_request_start(id, "exec", 1); 1979 client_expect_confirm(id, "exec", 1); 1980 } 1981 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 1982 packet_send(); 1983 } else { 1984 channel_request_start(id, "shell", 1); 1985 client_expect_confirm(id, "shell", 1); 1986 packet_send(); 1987 } 1988 } 1989 1990 static void 1991 client_init_dispatch_20(void) 1992 { 1993 dispatch_init(&dispatch_protocol_error); 1994 1995 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 1996 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 1997 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 1998 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 1999 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2000 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2001 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2002 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2003 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2004 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2005 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2006 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2007 2008 /* rekeying */ 2009 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 2010 2011 /* global request reply messages */ 2012 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2013 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2014 } 2015 2016 static void 2017 client_init_dispatch_13(void) 2018 { 2019 dispatch_init(NULL); 2020 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2021 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2022 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2023 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2024 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2025 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2026 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2027 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2028 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2029 2030 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2031 &client_input_agent_open : &deny_input_open); 2032 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2033 &x11_input_open : &deny_input_open); 2034 } 2035 2036 static void 2037 client_init_dispatch_15(void) 2038 { 2039 client_init_dispatch_13(); 2040 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2041 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2042 } 2043 2044 static void 2045 client_init_dispatch(void) 2046 { 2047 if (compat20) 2048 client_init_dispatch_20(); 2049 else if (compat13) 2050 client_init_dispatch_13(); 2051 else 2052 client_init_dispatch_15(); 2053 } 2054 2055 /* client specific fatal cleanup */ 2056 void 2057 cleanup_exit(int i) 2058 { 2059 leave_raw_mode(force_tty_flag); 2060 leave_non_blocking(); 2061 if (options.control_path != NULL && muxserver_sock != -1) 2062 unlink(options.control_path); 2063 _exit(i); 2064 } 2065