1 /* $OpenBSD: clientloop.c,v 1.209 2009/02/12 03:00:56 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" 112 113 /* import options */ 114 extern Options options; 115 116 /* Flag indicating that stdin should be redirected from /dev/null. */ 117 extern int stdin_null_flag; 118 119 /* Flag indicating that no shell has been requested */ 120 extern int no_shell_flag; 121 122 /* Control socket */ 123 extern int muxserver_sock; 124 125 /* 126 * Name of the host we are connecting to. This is the name given on the 127 * command line, or the HostName specified for the user-supplied name in a 128 * configuration file. 129 */ 130 extern char *host; 131 132 /* 133 * Flag to indicate that we have received a window change signal which has 134 * not yet been processed. This will cause a message indicating the new 135 * window size to be sent to the server a little later. This is volatile 136 * because this is updated in a signal handler. 137 */ 138 static volatile sig_atomic_t received_window_change_signal = 0; 139 static volatile sig_atomic_t received_signal = 0; 140 141 /* Flag indicating whether the user's terminal is in non-blocking mode. */ 142 static int in_non_blocking_mode = 0; 143 144 /* Common data for the client loop code. */ 145 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 146 static int escape_char1; /* Escape character. (proto1 only) */ 147 static int escape_pending1; /* Last character was an escape (proto1 only) */ 148 static int last_was_cr; /* Last character was a newline. */ 149 static int exit_status; /* Used to store the command exit status. */ 150 static int stdin_eof; /* EOF has been encountered on stderr. */ 151 static Buffer stdin_buffer; /* Buffer for stdin data. */ 152 static Buffer stdout_buffer; /* Buffer for stdout data. */ 153 static Buffer stderr_buffer; /* Buffer for stderr data. */ 154 static u_int buffer_high;/* Soft max buffer size. */ 155 static int connection_in; /* Connection to server (input). */ 156 static int connection_out; /* Connection to server (output). */ 157 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 158 static int session_closed = 0; /* In SSH2: login session closed. */ 159 160 static void client_init_dispatch(void); 161 int session_ident = -1; 162 163 /* Track escape per proto2 channel */ 164 struct escape_filter_ctx { 165 int escape_pending; 166 int escape_char; 167 }; 168 169 /* Context for channel confirmation replies */ 170 struct channel_reply_ctx { 171 const char *request_type; 172 int id, do_close; 173 }; 174 175 /* Global request success/failure callbacks */ 176 struct global_confirm { 177 TAILQ_ENTRY(global_confirm) entry; 178 global_confirm_cb *cb; 179 void *ctx; 180 int ref_count; 181 }; 182 TAILQ_HEAD(global_confirms, global_confirm); 183 static struct global_confirms global_confirms = 184 TAILQ_HEAD_INITIALIZER(global_confirms); 185 186 /*XXX*/ 187 extern Kex *xxx_kex; 188 189 void ssh_process_session2_setup(int, int, int, Buffer *); 190 191 /* Restores stdin to blocking mode. */ 192 193 static void 194 leave_non_blocking(void) 195 { 196 if (in_non_blocking_mode) { 197 unset_nonblock(fileno(stdin)); 198 in_non_blocking_mode = 0; 199 } 200 } 201 202 /* Puts stdin terminal in non-blocking mode. */ 203 204 static void 205 enter_non_blocking(void) 206 { 207 in_non_blocking_mode = 1; 208 set_nonblock(fileno(stdin)); 209 } 210 211 /* 212 * Signal handler for the window change signal (SIGWINCH). This just sets a 213 * flag indicating that the window has changed. 214 */ 215 /*ARGSUSED */ 216 static void 217 window_change_handler(int sig) 218 { 219 received_window_change_signal = 1; 220 signal(SIGWINCH, window_change_handler); 221 } 222 223 /* 224 * Signal handler for signals that cause the program to terminate. These 225 * signals must be trapped to restore terminal modes. 226 */ 227 /*ARGSUSED */ 228 static void 229 signal_handler(int sig) 230 { 231 received_signal = sig; 232 quit_pending = 1; 233 } 234 235 /* 236 * Returns current time in seconds from Jan 1, 1970 with the maximum 237 * available resolution. 238 */ 239 240 static double 241 get_current_time(void) 242 { 243 struct timeval tv; 244 gettimeofday(&tv, NULL); 245 return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; 246 } 247 248 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 249 void 250 client_x11_get_proto(const char *display, const char *xauth_path, 251 u_int trusted, char **_proto, char **_data) 252 { 253 char cmd[1024]; 254 char line[512]; 255 char xdisplay[512]; 256 static char proto[512], data[512]; 257 FILE *f; 258 int got_data = 0, generated = 0, do_unlink = 0, i; 259 char *xauthdir, *xauthfile; 260 struct stat st; 261 262 xauthdir = xauthfile = NULL; 263 *_proto = proto; 264 *_data = data; 265 proto[0] = data[0] = '\0'; 266 267 if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { 268 debug("No xauth program."); 269 } else { 270 if (display == NULL) { 271 debug("x11_get_proto: DISPLAY not set"); 272 return; 273 } 274 /* 275 * Handle FamilyLocal case where $DISPLAY does 276 * not match an authorization entry. For this we 277 * just try "xauth list unix:displaynum.screennum". 278 * XXX: "localhost" match to determine FamilyLocal 279 * is not perfect. 280 */ 281 if (strncmp(display, "localhost:", 10) == 0) { 282 snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 283 display + 10); 284 display = xdisplay; 285 } 286 if (trusted == 0) { 287 xauthdir = xmalloc(MAXPATHLEN); 288 xauthfile = xmalloc(MAXPATHLEN); 289 strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); 290 if (mkdtemp(xauthdir) != NULL) { 291 do_unlink = 1; 292 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", 293 xauthdir); 294 snprintf(cmd, sizeof(cmd), 295 "%s -f %s generate %s " SSH_X11_PROTO 296 " untrusted timeout 1200 2>" _PATH_DEVNULL, 297 xauth_path, xauthfile, display); 298 debug2("x11_get_proto: %s", cmd); 299 if (system(cmd) == 0) 300 generated = 1; 301 } 302 } 303 304 /* 305 * When in untrusted mode, we read the cookie only if it was 306 * successfully generated as an untrusted one in the step 307 * above. 308 */ 309 if (trusted || generated) { 310 snprintf(cmd, sizeof(cmd), 311 "%s %s%s list %s 2>" _PATH_DEVNULL, 312 xauth_path, 313 generated ? "-f " : "" , 314 generated ? xauthfile : "", 315 display); 316 debug2("x11_get_proto: %s", cmd); 317 f = popen(cmd, "r"); 318 if (f && fgets(line, sizeof(line), f) && 319 sscanf(line, "%*s %511s %511s", proto, data) == 2) 320 got_data = 1; 321 if (f) 322 pclose(f); 323 } else 324 error("Warning: untrusted X11 forwarding setup failed: " 325 "xauth key data not generated"); 326 } 327 328 if (do_unlink) { 329 unlink(xauthfile); 330 rmdir(xauthdir); 331 } 332 if (xauthdir) 333 xfree(xauthdir); 334 if (xauthfile) 335 xfree(xauthfile); 336 337 /* 338 * If we didn't get authentication data, just make up some 339 * data. The forwarding code will check the validity of the 340 * response anyway, and substitute this data. The X11 341 * server, however, will ignore this fake data and use 342 * whatever authentication mechanisms it was using otherwise 343 * for the local connection. 344 */ 345 if (!got_data) { 346 u_int32_t rnd = 0; 347 348 logit("Warning: No xauth data; " 349 "using fake authentication data for X11 forwarding."); 350 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 351 for (i = 0; i < 16; i++) { 352 if (i % 4 == 0) 353 rnd = arc4random(); 354 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 355 rnd & 0xff); 356 rnd >>= 8; 357 } 358 } 359 } 360 361 /* 362 * This is called when the interactive is entered. This checks if there is 363 * an EOF coming on stdin. We must check this explicitly, as select() does 364 * not appear to wake up when redirecting from /dev/null. 365 */ 366 367 static void 368 client_check_initial_eof_on_stdin(void) 369 { 370 int len; 371 char buf[1]; 372 373 /* 374 * If standard input is to be "redirected from /dev/null", we simply 375 * mark that we have seen an EOF and send an EOF message to the 376 * server. Otherwise, we try to read a single character; it appears 377 * that for some files, such /dev/null, select() never wakes up for 378 * read for this descriptor, which means that we never get EOF. This 379 * way we will get the EOF if stdin comes from /dev/null or similar. 380 */ 381 if (stdin_null_flag) { 382 /* Fake EOF on stdin. */ 383 debug("Sending eof."); 384 stdin_eof = 1; 385 packet_start(SSH_CMSG_EOF); 386 packet_send(); 387 } else { 388 enter_non_blocking(); 389 390 /* Check for immediate EOF on stdin. */ 391 len = read(fileno(stdin), buf, 1); 392 if (len == 0) { 393 /* 394 * EOF. Record that we have seen it and send 395 * EOF to server. 396 */ 397 debug("Sending eof."); 398 stdin_eof = 1; 399 packet_start(SSH_CMSG_EOF); 400 packet_send(); 401 } else if (len > 0) { 402 /* 403 * Got data. We must store the data in the buffer, 404 * and also process it as an escape character if 405 * appropriate. 406 */ 407 if ((u_char) buf[0] == escape_char1) 408 escape_pending1 = 1; 409 else 410 buffer_append(&stdin_buffer, buf, 1); 411 } 412 leave_non_blocking(); 413 } 414 } 415 416 417 /* 418 * Make packets from buffered stdin data, and buffer them for sending to the 419 * connection. 420 */ 421 422 static void 423 client_make_packets_from_stdin_data(void) 424 { 425 u_int len; 426 427 /* Send buffered stdin data to the server. */ 428 while (buffer_len(&stdin_buffer) > 0 && 429 packet_not_very_much_data_to_write()) { 430 len = buffer_len(&stdin_buffer); 431 /* Keep the packets at reasonable size. */ 432 if (len > packet_get_maxsize()) 433 len = packet_get_maxsize(); 434 packet_start(SSH_CMSG_STDIN_DATA); 435 packet_put_string(buffer_ptr(&stdin_buffer), len); 436 packet_send(); 437 buffer_consume(&stdin_buffer, len); 438 /* If we have a pending EOF, send it now. */ 439 if (stdin_eof && buffer_len(&stdin_buffer) == 0) { 440 packet_start(SSH_CMSG_EOF); 441 packet_send(); 442 } 443 } 444 } 445 446 /* 447 * Checks if the client window has changed, and sends a packet about it to 448 * the server if so. The actual change is detected elsewhere (by a software 449 * interrupt on Unix); this just checks the flag and sends a message if 450 * appropriate. 451 */ 452 453 static void 454 client_check_window_change(void) 455 { 456 struct winsize ws; 457 458 if (! received_window_change_signal) 459 return; 460 /** XXX race */ 461 received_window_change_signal = 0; 462 463 debug2("client_check_window_change: changed"); 464 465 if (compat20) { 466 channel_send_window_changes(); 467 } else { 468 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 469 return; 470 packet_start(SSH_CMSG_WINDOW_SIZE); 471 packet_put_int((u_int)ws.ws_row); 472 packet_put_int((u_int)ws.ws_col); 473 packet_put_int((u_int)ws.ws_xpixel); 474 packet_put_int((u_int)ws.ws_ypixel); 475 packet_send(); 476 } 477 } 478 479 static void 480 client_global_request_reply(int type, u_int32_t seq, void *ctxt) 481 { 482 struct global_confirm *gc; 483 484 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 485 return; 486 if (gc->cb != NULL) 487 gc->cb(type, seq, gc->ctx); 488 if (--gc->ref_count <= 0) { 489 TAILQ_REMOVE(&global_confirms, gc, entry); 490 bzero(gc, sizeof(*gc)); 491 xfree(gc); 492 } 493 494 keep_alive_timeouts = 0; 495 } 496 497 static void 498 server_alive_check(void) 499 { 500 if (++keep_alive_timeouts > options.server_alive_count_max) { 501 logit("Timeout, server not responding."); 502 cleanup_exit(255); 503 } 504 packet_start(SSH2_MSG_GLOBAL_REQUEST); 505 packet_put_cstring("keepalive@openssh.com"); 506 packet_put_char(1); /* boolean: want reply */ 507 packet_send(); 508 /* Insert an empty placeholder to maintain ordering */ 509 client_register_global_confirm(NULL, NULL); 510 } 511 512 /* 513 * Waits until the client can do something (some data becomes available on 514 * one of the file descriptors). 515 */ 516 static void 517 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, 518 int *maxfdp, u_int *nallocp, int rekeying) 519 { 520 struct timeval tv, *tvp; 521 int ret; 522 523 /* Add any selections by the channel mechanism. */ 524 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); 525 526 if (!compat20) { 527 /* Read from the connection, unless our buffers are full. */ 528 if (buffer_len(&stdout_buffer) < buffer_high && 529 buffer_len(&stderr_buffer) < buffer_high && 530 channel_not_very_much_buffered_data()) 531 FD_SET(connection_in, *readsetp); 532 /* 533 * Read from stdin, unless we have seen EOF or have very much 534 * buffered data to send to the server. 535 */ 536 if (!stdin_eof && packet_not_very_much_data_to_write()) 537 FD_SET(fileno(stdin), *readsetp); 538 539 /* Select stdout/stderr if have data in buffer. */ 540 if (buffer_len(&stdout_buffer) > 0) 541 FD_SET(fileno(stdout), *writesetp); 542 if (buffer_len(&stderr_buffer) > 0) 543 FD_SET(fileno(stderr), *writesetp); 544 } else { 545 /* channel_prepare_select could have closed the last channel */ 546 if (session_closed && !channel_still_open() && 547 !packet_have_data_to_write()) { 548 /* clear mask since we did not call select() */ 549 memset(*readsetp, 0, *nallocp); 550 memset(*writesetp, 0, *nallocp); 551 return; 552 } else { 553 FD_SET(connection_in, *readsetp); 554 } 555 } 556 557 /* Select server connection if have data to write to the server. */ 558 if (packet_have_data_to_write()) 559 FD_SET(connection_out, *writesetp); 560 561 if (muxserver_sock != -1) 562 FD_SET(muxserver_sock, *readsetp); 563 564 /* 565 * Wait for something to happen. This will suspend the process until 566 * some selected descriptor can be read, written, or has some other 567 * event pending. 568 */ 569 570 if (options.server_alive_interval == 0 || !compat20) 571 tvp = NULL; 572 else { 573 tv.tv_sec = options.server_alive_interval; 574 tv.tv_usec = 0; 575 tvp = &tv; 576 } 577 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 578 if (ret < 0) { 579 char buf[100]; 580 581 /* 582 * We have to clear the select masks, because we return. 583 * We have to return, because the mainloop checks for the flags 584 * set by the signal handlers. 585 */ 586 memset(*readsetp, 0, *nallocp); 587 memset(*writesetp, 0, *nallocp); 588 589 if (errno == EINTR) 590 return; 591 /* Note: we might still have data in the buffers. */ 592 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno)); 593 buffer_append(&stderr_buffer, buf, strlen(buf)); 594 quit_pending = 1; 595 } else if (ret == 0) 596 server_alive_check(); 597 } 598 599 static void 600 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) 601 { 602 /* Flush stdout and stderr buffers. */ 603 if (buffer_len(bout) > 0) 604 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), 605 buffer_len(bout)); 606 if (buffer_len(berr) > 0) 607 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), 608 buffer_len(berr)); 609 610 leave_raw_mode(); 611 612 /* 613 * Free (and clear) the buffer to reduce the amount of data that gets 614 * written to swap. 615 */ 616 buffer_free(bin); 617 buffer_free(bout); 618 buffer_free(berr); 619 620 /* Send the suspend signal to the program itself. */ 621 kill(getpid(), SIGTSTP); 622 623 /* Reset window sizes in case they have changed */ 624 received_window_change_signal = 1; 625 626 /* OK, we have been continued by the user. Reinitialize buffers. */ 627 buffer_init(bin); 628 buffer_init(bout); 629 buffer_init(berr); 630 631 enter_raw_mode(); 632 } 633 634 static void 635 client_process_net_input(fd_set *readset) 636 { 637 int len; 638 char buf[8192]; 639 640 /* 641 * Read input from the server, and add any such data to the buffer of 642 * the packet subsystem. 643 */ 644 if (FD_ISSET(connection_in, readset)) { 645 /* Read as much as possible. */ 646 len = read(connection_in, buf, sizeof(buf)); 647 if (len == 0) { 648 /* 649 * Received EOF. The remote host has closed the 650 * connection. 651 */ 652 snprintf(buf, sizeof buf, 653 "Connection to %.300s closed by remote host.\r\n", 654 host); 655 buffer_append(&stderr_buffer, buf, strlen(buf)); 656 quit_pending = 1; 657 return; 658 } 659 /* 660 * There is a kernel bug on Solaris that causes select to 661 * sometimes wake up even though there is no data available. 662 */ 663 if (len < 0 && 664 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 665 len = 0; 666 667 if (len < 0) { 668 /* 669 * An error has encountered. Perhaps there is a 670 * network problem. 671 */ 672 snprintf(buf, sizeof buf, 673 "Read from remote host %.300s: %.100s\r\n", 674 host, strerror(errno)); 675 buffer_append(&stderr_buffer, buf, strlen(buf)); 676 quit_pending = 1; 677 return; 678 } 679 packet_process_incoming(buf, len); 680 } 681 } 682 683 static void 684 client_status_confirm(int type, Channel *c, void *ctx) 685 { 686 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 687 char errmsg[256]; 688 int tochan; 689 690 /* XXX supress on mux _client_ quietmode */ 691 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 692 c->ctl_fd != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 693 694 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 695 debug2("%s request accepted on channel %d", 696 cr->request_type, c->self); 697 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 698 if (tochan) { 699 snprintf(errmsg, sizeof(errmsg), 700 "%s request failed\r\n", cr->request_type); 701 } else { 702 snprintf(errmsg, sizeof(errmsg), 703 "%s request failed on channel %d", 704 cr->request_type, c->self); 705 } 706 /* If error occurred on primary session channel, then exit */ 707 if (cr->do_close && c->self == session_ident) 708 fatal("%s", errmsg); 709 /* If error occurred on mux client, append to their stderr */ 710 if (tochan) 711 buffer_append(&c->extended, errmsg, strlen(errmsg)); 712 else 713 error("%s", errmsg); 714 if (cr->do_close) { 715 chan_read_failed(c); 716 chan_write_failed(c); 717 } 718 } 719 xfree(cr); 720 } 721 722 static void 723 client_abandon_status_confirm(Channel *c, void *ctx) 724 { 725 xfree(ctx); 726 } 727 728 static void 729 client_expect_confirm(int id, const char *request, int do_close) 730 { 731 struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); 732 733 cr->request_type = request; 734 cr->do_close = do_close; 735 736 channel_register_status_confirm(id, client_status_confirm, 737 client_abandon_status_confirm, cr); 738 } 739 740 void 741 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 742 { 743 struct global_confirm *gc, *last_gc; 744 745 /* Coalesce identical callbacks */ 746 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 747 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 748 if (++last_gc->ref_count >= INT_MAX) 749 fatal("%s: last_gc->ref_count = %d", 750 __func__, last_gc->ref_count); 751 return; 752 } 753 754 gc = xmalloc(sizeof(*gc)); 755 gc->cb = cb; 756 gc->ctx = ctx; 757 gc->ref_count = 1; 758 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 759 } 760 761 static void 762 process_cmdline(void) 763 { 764 void (*handler)(int); 765 char *s, *cmd, *cancel_host; 766 int delete = 0; 767 int local = 0, remote = 0, dynamic = 0; 768 int cancel_port; 769 Forward fwd; 770 771 bzero(&fwd, sizeof(fwd)); 772 fwd.listen_host = fwd.connect_host = NULL; 773 774 leave_raw_mode(); 775 handler = signal(SIGINT, SIG_IGN); 776 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 777 if (s == NULL) 778 goto out; 779 while (isspace(*s)) 780 s++; 781 if (*s == '-') 782 s++; /* Skip cmdline '-', if any */ 783 if (*s == '\0') 784 goto out; 785 786 if (*s == 'h' || *s == 'H' || *s == '?') { 787 logit("Commands:"); 788 logit(" -L[bind_address:]port:host:hostport " 789 "Request local forward"); 790 logit(" -R[bind_address:]port:host:hostport " 791 "Request remote forward"); 792 logit(" -D[bind_address:]port " 793 "Request dynamic forward"); 794 logit(" -KR[bind_address:]port " 795 "Cancel remote forward"); 796 if (!options.permit_local_command) 797 goto out; 798 logit(" !args " 799 "Execute local command"); 800 goto out; 801 } 802 803 if (*s == '!' && options.permit_local_command) { 804 s++; 805 ssh_local_cmd(s); 806 goto out; 807 } 808 809 if (*s == 'K') { 810 delete = 1; 811 s++; 812 } 813 if (*s == 'L') 814 local = 1; 815 else if (*s == 'R') 816 remote = 1; 817 else if (*s == 'D') 818 dynamic = 1; 819 else { 820 logit("Invalid command."); 821 goto out; 822 } 823 824 if ((local || dynamic) && delete) { 825 logit("Not supported."); 826 goto out; 827 } 828 if (remote && delete && !compat20) { 829 logit("Not supported for SSH protocol version 1."); 830 goto out; 831 } 832 833 while (isspace(*++s)) 834 ; 835 836 if (delete) { 837 cancel_port = 0; 838 cancel_host = hpdelim(&s); /* may be NULL */ 839 if (s != NULL) { 840 cancel_port = a2port(s); 841 cancel_host = cleanhostname(cancel_host); 842 } else { 843 cancel_port = a2port(cancel_host); 844 cancel_host = NULL; 845 } 846 if (cancel_port <= 0) { 847 logit("Bad forwarding close port"); 848 goto out; 849 } 850 channel_request_rforward_cancel(cancel_host, cancel_port); 851 } else { 852 if (!parse_forward(&fwd, s, dynamic, remote)) { 853 logit("Bad forwarding specification."); 854 goto out; 855 } 856 if (local || dynamic) { 857 if (channel_setup_local_fwd_listener(fwd.listen_host, 858 fwd.listen_port, fwd.connect_host, 859 fwd.connect_port, options.gateway_ports) < 0) { 860 logit("Port forwarding failed."); 861 goto out; 862 } 863 } else { 864 if (channel_request_remote_forwarding(fwd.listen_host, 865 fwd.listen_port, fwd.connect_host, 866 fwd.connect_port) < 0) { 867 logit("Port forwarding failed."); 868 goto out; 869 } 870 } 871 872 logit("Forwarding port."); 873 } 874 875 out: 876 signal(SIGINT, handler); 877 enter_raw_mode(); 878 if (cmd) 879 xfree(cmd); 880 if (fwd.listen_host != NULL) 881 xfree(fwd.listen_host); 882 if (fwd.connect_host != NULL) 883 xfree(fwd.connect_host); 884 } 885 886 /* 887 * Process the characters one by one, call with c==NULL for proto1 case. 888 */ 889 static int 890 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr, 891 char *buf, int len) 892 { 893 char string[1024]; 894 pid_t pid; 895 int bytes = 0; 896 u_int i; 897 u_char ch; 898 char *s; 899 int *escape_pendingp, escape_char; 900 struct escape_filter_ctx *efc; 901 902 if (c == NULL) { 903 escape_pendingp = &escape_pending1; 904 escape_char = escape_char1; 905 } else { 906 if (c->filter_ctx == NULL) 907 return 0; 908 efc = (struct escape_filter_ctx *)c->filter_ctx; 909 escape_pendingp = &efc->escape_pending; 910 escape_char = efc->escape_char; 911 } 912 913 if (len <= 0) 914 return (0); 915 916 for (i = 0; i < (u_int)len; i++) { 917 /* Get one character at a time. */ 918 ch = buf[i]; 919 920 if (*escape_pendingp) { 921 /* We have previously seen an escape character. */ 922 /* Clear the flag now. */ 923 *escape_pendingp = 0; 924 925 /* Process the escaped character. */ 926 switch (ch) { 927 case '.': 928 /* Terminate the connection. */ 929 snprintf(string, sizeof string, "%c.\r\n", 930 escape_char); 931 buffer_append(berr, string, strlen(string)); 932 933 if (c && c->ctl_fd != -1) { 934 chan_read_failed(c); 935 chan_write_failed(c); 936 return 0; 937 } else 938 quit_pending = 1; 939 return -1; 940 941 case 'Z' - 64: 942 /* XXX support this for mux clients */ 943 if (c && c->ctl_fd != -1) { 944 noescape: 945 snprintf(string, sizeof string, 946 "%c%c escape not available to " 947 "multiplexed sessions\r\n", 948 escape_char, ch); 949 buffer_append(berr, string, 950 strlen(string)); 951 continue; 952 } 953 /* Suspend the program. Inform the user */ 954 snprintf(string, sizeof string, 955 "%c^Z [suspend ssh]\r\n", escape_char); 956 buffer_append(berr, string, strlen(string)); 957 958 /* Restore terminal modes and suspend. */ 959 client_suspend_self(bin, bout, berr); 960 961 /* We have been continued. */ 962 continue; 963 964 case 'B': 965 if (compat20) { 966 snprintf(string, sizeof string, 967 "%cB\r\n", escape_char); 968 buffer_append(berr, string, 969 strlen(string)); 970 channel_request_start(session_ident, 971 "break", 0); 972 packet_put_int(1000); 973 packet_send(); 974 } 975 continue; 976 977 case 'R': 978 if (compat20) { 979 if (datafellows & SSH_BUG_NOREKEY) 980 logit("Server does not " 981 "support re-keying"); 982 else 983 need_rekeying = 1; 984 } 985 continue; 986 987 case '&': 988 if (c && c->ctl_fd != -1) 989 goto noescape; 990 /* 991 * Detach the program (continue to serve 992 * connections, but put in background and no 993 * more new connections). 994 */ 995 /* Restore tty modes. */ 996 leave_raw_mode(); 997 998 /* Stop listening for new connections. */ 999 channel_stop_listening(); 1000 1001 snprintf(string, sizeof string, 1002 "%c& [backgrounded]\n", escape_char); 1003 buffer_append(berr, string, strlen(string)); 1004 1005 /* Fork into background. */ 1006 pid = fork(); 1007 if (pid < 0) { 1008 error("fork: %.100s", strerror(errno)); 1009 continue; 1010 } 1011 if (pid != 0) { /* This is the parent. */ 1012 /* The parent just exits. */ 1013 exit(0); 1014 } 1015 /* The child continues serving connections. */ 1016 if (compat20) { 1017 buffer_append(bin, "\004", 1); 1018 /* fake EOF on stdin */ 1019 return -1; 1020 } else if (!stdin_eof) { 1021 /* 1022 * Sending SSH_CMSG_EOF alone does not 1023 * always appear to be enough. So we 1024 * try to send an EOF character first. 1025 */ 1026 packet_start(SSH_CMSG_STDIN_DATA); 1027 packet_put_string("\004", 1); 1028 packet_send(); 1029 /* Close stdin. */ 1030 stdin_eof = 1; 1031 if (buffer_len(bin) == 0) { 1032 packet_start(SSH_CMSG_EOF); 1033 packet_send(); 1034 } 1035 } 1036 continue; 1037 1038 case '?': 1039 if (c && c->ctl_fd != -1) { 1040 snprintf(string, sizeof string, 1041 "%c?\r\n\ 1042 Supported escape sequences:\r\n\ 1043 %c. - terminate session\r\n\ 1044 %cB - send a BREAK to the remote system\r\n\ 1045 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1046 %c# - list forwarded connections\r\n\ 1047 %c? - this message\r\n\ 1048 %c%c - send the escape character by typing it twice\r\n\ 1049 (Note that escapes are only recognized immediately after newline.)\r\n", 1050 escape_char, escape_char, 1051 escape_char, escape_char, 1052 escape_char, escape_char, 1053 escape_char, escape_char); 1054 } else { 1055 snprintf(string, sizeof string, 1056 "%c?\r\n\ 1057 Supported escape sequences:\r\n\ 1058 %c. - terminate connection (and any multiplexed sessions)\r\n\ 1059 %cB - send a BREAK to the remote system\r\n\ 1060 %cC - open a command line\r\n\ 1061 %cR - Request rekey (SSH protocol 2 only)\r\n\ 1062 %c^Z - suspend ssh\r\n\ 1063 %c# - list forwarded connections\r\n\ 1064 %c& - background ssh (when waiting for connections to terminate)\r\n\ 1065 %c? - this message\r\n\ 1066 %c%c - send the escape character by typing it twice\r\n\ 1067 (Note that escapes are only recognized immediately after newline.)\r\n", 1068 escape_char, escape_char, 1069 escape_char, escape_char, 1070 escape_char, escape_char, 1071 escape_char, escape_char, 1072 escape_char, escape_char, 1073 escape_char); 1074 } 1075 buffer_append(berr, string, strlen(string)); 1076 continue; 1077 1078 case '#': 1079 snprintf(string, sizeof string, "%c#\r\n", 1080 escape_char); 1081 buffer_append(berr, string, strlen(string)); 1082 s = channel_open_message(); 1083 buffer_append(berr, s, strlen(s)); 1084 xfree(s); 1085 continue; 1086 1087 case 'C': 1088 if (c && c->ctl_fd != -1) 1089 goto noescape; 1090 process_cmdline(); 1091 continue; 1092 1093 default: 1094 if (ch != escape_char) { 1095 buffer_put_char(bin, escape_char); 1096 bytes++; 1097 } 1098 /* Escaped characters fall through here */ 1099 break; 1100 } 1101 } else { 1102 /* 1103 * The previous character was not an escape char. 1104 * Check if this is an escape. 1105 */ 1106 if (last_was_cr && ch == escape_char) { 1107 /* 1108 * It is. Set the flag and continue to 1109 * next character. 1110 */ 1111 *escape_pendingp = 1; 1112 continue; 1113 } 1114 } 1115 1116 /* 1117 * Normal character. Record whether it was a newline, 1118 * and append it to the buffer. 1119 */ 1120 last_was_cr = (ch == '\r' || ch == '\n'); 1121 buffer_put_char(bin, ch); 1122 bytes++; 1123 } 1124 return bytes; 1125 } 1126 1127 static void 1128 client_process_input(fd_set *readset) 1129 { 1130 int len; 1131 char buf[8192]; 1132 1133 /* Read input from stdin. */ 1134 if (FD_ISSET(fileno(stdin), readset)) { 1135 /* Read as much as possible. */ 1136 len = read(fileno(stdin), buf, sizeof(buf)); 1137 if (len < 0 && 1138 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 1139 return; /* we'll try again later */ 1140 if (len <= 0) { 1141 /* 1142 * Received EOF or error. They are treated 1143 * similarly, except that an error message is printed 1144 * if it was an error condition. 1145 */ 1146 if (len < 0) { 1147 snprintf(buf, sizeof buf, "read: %.100s\r\n", 1148 strerror(errno)); 1149 buffer_append(&stderr_buffer, buf, strlen(buf)); 1150 } 1151 /* Mark that we have seen EOF. */ 1152 stdin_eof = 1; 1153 /* 1154 * Send an EOF message to the server unless there is 1155 * data in the buffer. If there is data in the 1156 * buffer, no message will be sent now. Code 1157 * elsewhere will send the EOF when the buffer 1158 * becomes empty if stdin_eof is set. 1159 */ 1160 if (buffer_len(&stdin_buffer) == 0) { 1161 packet_start(SSH_CMSG_EOF); 1162 packet_send(); 1163 } 1164 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) { 1165 /* 1166 * Normal successful read, and no escape character. 1167 * Just append the data to buffer. 1168 */ 1169 buffer_append(&stdin_buffer, buf, len); 1170 } else { 1171 /* 1172 * Normal, successful read. But we have an escape 1173 * character and have to process the characters one 1174 * by one. 1175 */ 1176 if (process_escapes(NULL, &stdin_buffer, 1177 &stdout_buffer, &stderr_buffer, buf, len) == -1) 1178 return; 1179 } 1180 } 1181 } 1182 1183 static void 1184 client_process_output(fd_set *writeset) 1185 { 1186 int len; 1187 char buf[100]; 1188 1189 /* Write buffered output to stdout. */ 1190 if (FD_ISSET(fileno(stdout), writeset)) { 1191 /* Write as much data as possible. */ 1192 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1193 buffer_len(&stdout_buffer)); 1194 if (len <= 0) { 1195 if (errno == EINTR || errno == EAGAIN || 1196 errno == EWOULDBLOCK) 1197 len = 0; 1198 else { 1199 /* 1200 * An error or EOF was encountered. Put an 1201 * error message to stderr buffer. 1202 */ 1203 snprintf(buf, sizeof buf, 1204 "write stdout: %.50s\r\n", strerror(errno)); 1205 buffer_append(&stderr_buffer, buf, strlen(buf)); 1206 quit_pending = 1; 1207 return; 1208 } 1209 } 1210 /* Consume printed data from the buffer. */ 1211 buffer_consume(&stdout_buffer, len); 1212 } 1213 /* Write buffered output to stderr. */ 1214 if (FD_ISSET(fileno(stderr), writeset)) { 1215 /* Write as much data as possible. */ 1216 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1217 buffer_len(&stderr_buffer)); 1218 if (len <= 0) { 1219 if (errno == EINTR || errno == EAGAIN || 1220 errno == EWOULDBLOCK) 1221 len = 0; 1222 else { 1223 /* 1224 * EOF or error, but can't even print 1225 * error message. 1226 */ 1227 quit_pending = 1; 1228 return; 1229 } 1230 } 1231 /* Consume printed characters from the buffer. */ 1232 buffer_consume(&stderr_buffer, len); 1233 } 1234 } 1235 1236 /* 1237 * Get packets from the connection input buffer, and process them as long as 1238 * there are packets available. 1239 * 1240 * Any unknown packets received during the actual 1241 * session cause the session to terminate. This is 1242 * intended to make debugging easier since no 1243 * confirmations are sent. Any compatible protocol 1244 * extensions must be negotiated during the 1245 * preparatory phase. 1246 */ 1247 1248 static void 1249 client_process_buffered_input_packets(void) 1250 { 1251 dispatch_run(DISPATCH_NONBLOCK, &quit_pending, 1252 compat20 ? xxx_kex : NULL); 1253 } 1254 1255 /* scan buf[] for '~' before sending data to the peer */ 1256 1257 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1258 void * 1259 client_new_escape_filter_ctx(int escape_char) 1260 { 1261 struct escape_filter_ctx *ret; 1262 1263 ret = xmalloc(sizeof(*ret)); 1264 ret->escape_pending = 0; 1265 ret->escape_char = escape_char; 1266 return (void *)ret; 1267 } 1268 1269 /* Free the escape filter context on channel free */ 1270 void 1271 client_filter_cleanup(int cid, void *ctx) 1272 { 1273 xfree(ctx); 1274 } 1275 1276 int 1277 client_simple_escape_filter(Channel *c, char *buf, int len) 1278 { 1279 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1280 return 0; 1281 1282 return process_escapes(c, &c->input, &c->output, &c->extended, 1283 buf, len); 1284 } 1285 1286 static void 1287 client_channel_closed(int id, void *arg) 1288 { 1289 channel_cancel_cleanup(id); 1290 session_closed = 1; 1291 leave_raw_mode(); 1292 } 1293 1294 /* 1295 * Implements the interactive session with the server. This is called after 1296 * the user has been authenticated, and a command has been started on the 1297 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1298 * used as an escape character for terminating or suspending the session. 1299 */ 1300 1301 int 1302 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) 1303 { 1304 fd_set *readset = NULL, *writeset = NULL; 1305 double start_time, total_time; 1306 int max_fd = 0, max_fd2 = 0, len, rekeying = 0; 1307 u_int64_t ibytes, obytes; 1308 u_int nalloc = 0; 1309 char buf[100]; 1310 1311 debug("Entering interactive session."); 1312 1313 start_time = get_current_time(); 1314 1315 /* Initialize variables. */ 1316 escape_pending1 = 0; 1317 last_was_cr = 1; 1318 exit_status = -1; 1319 stdin_eof = 0; 1320 buffer_high = 64 * 1024; 1321 connection_in = packet_get_connection_in(); 1322 connection_out = packet_get_connection_out(); 1323 max_fd = MAX(connection_in, connection_out); 1324 if (muxserver_sock != -1) 1325 max_fd = MAX(max_fd, muxserver_sock); 1326 1327 if (!compat20) { 1328 /* enable nonblocking unless tty */ 1329 if (!isatty(fileno(stdin))) 1330 set_nonblock(fileno(stdin)); 1331 if (!isatty(fileno(stdout))) 1332 set_nonblock(fileno(stdout)); 1333 if (!isatty(fileno(stderr))) 1334 set_nonblock(fileno(stderr)); 1335 max_fd = MAX(max_fd, fileno(stdin)); 1336 max_fd = MAX(max_fd, fileno(stdout)); 1337 max_fd = MAX(max_fd, fileno(stderr)); 1338 } 1339 quit_pending = 0; 1340 escape_char1 = escape_char_arg; 1341 1342 /* Initialize buffers. */ 1343 buffer_init(&stdin_buffer); 1344 buffer_init(&stdout_buffer); 1345 buffer_init(&stderr_buffer); 1346 1347 client_init_dispatch(); 1348 1349 /* 1350 * Set signal handlers, (e.g. to restore non-blocking mode) 1351 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1352 */ 1353 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) 1354 signal(SIGHUP, signal_handler); 1355 if (signal(SIGINT, SIG_IGN) != SIG_IGN) 1356 signal(SIGINT, signal_handler); 1357 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1358 signal(SIGQUIT, signal_handler); 1359 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) 1360 signal(SIGTERM, signal_handler); 1361 signal(SIGWINCH, window_change_handler); 1362 1363 if (have_pty) 1364 enter_raw_mode(); 1365 1366 if (compat20) { 1367 session_ident = ssh2_chan_id; 1368 if (escape_char_arg != SSH_ESCAPECHAR_NONE) 1369 channel_register_filter(session_ident, 1370 client_simple_escape_filter, NULL, 1371 client_filter_cleanup, 1372 client_new_escape_filter_ctx(escape_char_arg)); 1373 if (session_ident != -1) 1374 channel_register_cleanup(session_ident, 1375 client_channel_closed, 0); 1376 } else { 1377 /* Check if we should immediately send eof on stdin. */ 1378 client_check_initial_eof_on_stdin(); 1379 } 1380 1381 /* Main loop of the client for the interactive session mode. */ 1382 while (!quit_pending) { 1383 1384 /* Process buffered packets sent by the server. */ 1385 client_process_buffered_input_packets(); 1386 1387 if (compat20 && session_closed && !channel_still_open()) 1388 break; 1389 1390 rekeying = (xxx_kex != NULL && !xxx_kex->done); 1391 1392 if (rekeying) { 1393 debug("rekeying in progress"); 1394 } else { 1395 /* 1396 * Make packets of buffered stdin data, and buffer 1397 * them for sending to the server. 1398 */ 1399 if (!compat20) 1400 client_make_packets_from_stdin_data(); 1401 1402 /* 1403 * Make packets from buffered channel data, and 1404 * enqueue them for sending to the server. 1405 */ 1406 if (packet_not_very_much_data_to_write()) 1407 channel_output_poll(); 1408 1409 /* 1410 * Check if the window size has changed, and buffer a 1411 * message about it to the server if so. 1412 */ 1413 client_check_window_change(); 1414 1415 if (quit_pending) 1416 break; 1417 } 1418 /* 1419 * Wait until we have something to do (something becomes 1420 * available on one of the descriptors). 1421 */ 1422 max_fd2 = max_fd; 1423 client_wait_until_can_do_something(&readset, &writeset, 1424 &max_fd2, &nalloc, rekeying); 1425 1426 if (quit_pending) 1427 break; 1428 1429 /* Do channel operations unless rekeying in progress. */ 1430 if (!rekeying) { 1431 channel_after_select(readset, writeset); 1432 if (need_rekeying || packet_need_rekeying()) { 1433 debug("need rekeying"); 1434 xxx_kex->done = 0; 1435 kex_send_kexinit(xxx_kex); 1436 need_rekeying = 0; 1437 } 1438 } 1439 1440 /* Buffer input from the connection. */ 1441 client_process_net_input(readset); 1442 1443 /* Accept control connections. */ 1444 if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) { 1445 if (muxserver_accept_control()) 1446 quit_pending = 1; 1447 } 1448 1449 if (quit_pending) 1450 break; 1451 1452 if (!compat20) { 1453 /* Buffer data from stdin */ 1454 client_process_input(readset); 1455 /* 1456 * Process output to stdout and stderr. Output to 1457 * the connection is processed elsewhere (above). 1458 */ 1459 client_process_output(writeset); 1460 } 1461 1462 /* 1463 * Send as much buffered packet data as possible to the 1464 * sender. 1465 */ 1466 if (FD_ISSET(connection_out, writeset)) 1467 packet_write_poll(); 1468 } 1469 if (readset) 1470 xfree(readset); 1471 if (writeset) 1472 xfree(writeset); 1473 1474 /* Terminate the session. */ 1475 1476 /* Stop watching for window change. */ 1477 signal(SIGWINCH, SIG_DFL); 1478 1479 channel_free_all(); 1480 1481 if (have_pty) 1482 leave_raw_mode(); 1483 1484 /* restore blocking io */ 1485 if (!isatty(fileno(stdin))) 1486 unset_nonblock(fileno(stdin)); 1487 if (!isatty(fileno(stdout))) 1488 unset_nonblock(fileno(stdout)); 1489 if (!isatty(fileno(stderr))) 1490 unset_nonblock(fileno(stderr)); 1491 1492 /* 1493 * If there was no shell or command requested, there will be no remote 1494 * exit status to be returned. In that case, clear error code if the 1495 * connection was deliberately terminated at this end. 1496 */ 1497 if (no_shell_flag && received_signal == SIGTERM) { 1498 received_signal = 0; 1499 exit_status = 0; 1500 } 1501 1502 if (received_signal) 1503 fatal("Killed by signal %d.", (int) received_signal); 1504 1505 /* 1506 * In interactive mode (with pseudo tty) display a message indicating 1507 * that the connection has been closed. 1508 */ 1509 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1510 snprintf(buf, sizeof buf, 1511 "Connection to %.64s closed.\r\n", host); 1512 buffer_append(&stderr_buffer, buf, strlen(buf)); 1513 } 1514 1515 /* Output any buffered data for stdout. */ 1516 while (buffer_len(&stdout_buffer) > 0) { 1517 len = write(fileno(stdout), buffer_ptr(&stdout_buffer), 1518 buffer_len(&stdout_buffer)); 1519 if (len <= 0) { 1520 error("Write failed flushing stdout buffer."); 1521 break; 1522 } 1523 buffer_consume(&stdout_buffer, len); 1524 } 1525 1526 /* Output any buffered data for stderr. */ 1527 while (buffer_len(&stderr_buffer) > 0) { 1528 len = write(fileno(stderr), buffer_ptr(&stderr_buffer), 1529 buffer_len(&stderr_buffer)); 1530 if (len <= 0) { 1531 error("Write failed flushing stderr buffer."); 1532 break; 1533 } 1534 buffer_consume(&stderr_buffer, len); 1535 } 1536 1537 /* Clear and free any buffers. */ 1538 memset(buf, 0, sizeof(buf)); 1539 buffer_free(&stdin_buffer); 1540 buffer_free(&stdout_buffer); 1541 buffer_free(&stderr_buffer); 1542 1543 /* Report bytes transferred, and transfer rates. */ 1544 total_time = get_current_time() - start_time; 1545 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes); 1546 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes); 1547 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1548 obytes, ibytes, total_time); 1549 if (total_time > 0) 1550 verbose("Bytes per second: sent %.1f, received %.1f", 1551 obytes / total_time, ibytes / total_time); 1552 /* Return the exit status of the program. */ 1553 debug("Exit status %d", exit_status); 1554 return exit_status; 1555 } 1556 1557 /*********/ 1558 1559 static void 1560 client_input_stdout_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(&stdout_buffer, data, data_len); 1566 memset(data, 0, data_len); 1567 xfree(data); 1568 } 1569 static void 1570 client_input_stderr_data(int type, u_int32_t seq, void *ctxt) 1571 { 1572 u_int data_len; 1573 char *data = packet_get_string(&data_len); 1574 packet_check_eom(); 1575 buffer_append(&stderr_buffer, data, data_len); 1576 memset(data, 0, data_len); 1577 xfree(data); 1578 } 1579 static void 1580 client_input_exit_status(int type, u_int32_t seq, void *ctxt) 1581 { 1582 exit_status = packet_get_int(); 1583 packet_check_eom(); 1584 /* Acknowledge the exit. */ 1585 packet_start(SSH_CMSG_EXIT_CONFIRMATION); 1586 packet_send(); 1587 /* 1588 * Must wait for packet to be sent since we are 1589 * exiting the loop. 1590 */ 1591 packet_write_wait(); 1592 /* Flag that we want to exit. */ 1593 quit_pending = 1; 1594 } 1595 static void 1596 client_input_agent_open(int type, u_int32_t seq, void *ctxt) 1597 { 1598 Channel *c = NULL; 1599 int remote_id, sock; 1600 1601 /* Read the remote channel number from the message. */ 1602 remote_id = packet_get_int(); 1603 packet_check_eom(); 1604 1605 /* 1606 * Get a connection to the local authentication agent (this may again 1607 * get forwarded). 1608 */ 1609 sock = ssh_get_authentication_socket(); 1610 1611 /* 1612 * If we could not connect the agent, send an error message back to 1613 * the server. This should never happen unless the agent dies, 1614 * because authentication forwarding is only enabled if we have an 1615 * agent. 1616 */ 1617 if (sock >= 0) { 1618 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, 1619 -1, 0, 0, 0, "authentication agent connection", 1); 1620 c->remote_id = remote_id; 1621 c->force_drain = 1; 1622 } 1623 if (c == NULL) { 1624 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); 1625 packet_put_int(remote_id); 1626 } else { 1627 /* Send a confirmation to the remote host. */ 1628 debug("Forwarding authentication connection."); 1629 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); 1630 packet_put_int(remote_id); 1631 packet_put_int(c->self); 1632 } 1633 packet_send(); 1634 } 1635 1636 static Channel * 1637 client_request_forwarded_tcpip(const char *request_type, int rchan) 1638 { 1639 Channel *c = NULL; 1640 char *listen_address, *originator_address; 1641 u_short listen_port, originator_port; 1642 1643 /* Get rest of the packet */ 1644 listen_address = packet_get_string(NULL); 1645 listen_port = packet_get_int(); 1646 originator_address = packet_get_string(NULL); 1647 originator_port = packet_get_int(); 1648 packet_check_eom(); 1649 1650 debug("client_request_forwarded_tcpip: listen %s port %d, " 1651 "originator %s port %d", listen_address, listen_port, 1652 originator_address, originator_port); 1653 1654 c = channel_connect_by_listen_address(listen_port, 1655 "forwarded-tcpip", originator_address); 1656 1657 xfree(originator_address); 1658 xfree(listen_address); 1659 return c; 1660 } 1661 1662 static Channel * 1663 client_request_x11(const char *request_type, int rchan) 1664 { 1665 Channel *c = NULL; 1666 char *originator; 1667 u_short originator_port; 1668 int sock; 1669 1670 if (!options.forward_x11) { 1671 error("Warning: ssh server tried X11 forwarding."); 1672 error("Warning: this is probably a break-in attempt by a " 1673 "malicious server."); 1674 return NULL; 1675 } 1676 originator = packet_get_string(NULL); 1677 if (datafellows & SSH_BUG_X11FWD) { 1678 debug2("buggy server: x11 request w/o originator_port"); 1679 originator_port = 0; 1680 } else { 1681 originator_port = packet_get_int(); 1682 } 1683 packet_check_eom(); 1684 /* XXX check permission */ 1685 debug("client_request_x11: request from %s %d", originator, 1686 originator_port); 1687 xfree(originator); 1688 sock = x11_connect_display(); 1689 if (sock < 0) 1690 return NULL; 1691 c = channel_new("x11", 1692 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1693 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1694 c->force_drain = 1; 1695 return c; 1696 } 1697 1698 static Channel * 1699 client_request_agent(const char *request_type, int rchan) 1700 { 1701 Channel *c = NULL; 1702 int sock; 1703 1704 if (!options.forward_agent) { 1705 error("Warning: ssh server tried agent forwarding."); 1706 error("Warning: this is probably a break-in attempt by a " 1707 "malicious server."); 1708 return NULL; 1709 } 1710 sock = ssh_get_authentication_socket(); 1711 if (sock < 0) 1712 return NULL; 1713 c = channel_new("authentication agent connection", 1714 SSH_CHANNEL_OPEN, sock, sock, -1, 1715 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1716 "authentication agent connection", 1); 1717 c->force_drain = 1; 1718 return c; 1719 } 1720 1721 int 1722 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) 1723 { 1724 Channel *c; 1725 int fd; 1726 1727 if (tun_mode == SSH_TUNMODE_NO) 1728 return 0; 1729 1730 if (!compat20) { 1731 error("Tunnel forwarding is not supported for protocol 1"); 1732 return -1; 1733 } 1734 1735 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1736 1737 /* Open local tunnel device */ 1738 if ((fd = tun_open(local_tun, tun_mode)) == -1) { 1739 error("Tunnel device open failed."); 1740 return -1; 1741 } 1742 1743 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1744 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1745 c->datagram = 1; 1746 1747 #if defined(SSH_TUN_FILTER) 1748 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1749 channel_register_filter(c->self, sys_tun_infilter, 1750 sys_tun_outfilter, NULL, NULL); 1751 #endif 1752 1753 packet_start(SSH2_MSG_CHANNEL_OPEN); 1754 packet_put_cstring("tun@openssh.com"); 1755 packet_put_int(c->self); 1756 packet_put_int(c->local_window_max); 1757 packet_put_int(c->local_maxpacket); 1758 packet_put_int(tun_mode); 1759 packet_put_int(remote_tun); 1760 packet_send(); 1761 1762 return 0; 1763 } 1764 1765 /* XXXX move to generic input handler */ 1766 static void 1767 client_input_channel_open(int type, u_int32_t seq, void *ctxt) 1768 { 1769 Channel *c = NULL; 1770 char *ctype; 1771 int rchan; 1772 u_int rmaxpack, rwindow, len; 1773 1774 ctype = packet_get_string(&len); 1775 rchan = packet_get_int(); 1776 rwindow = packet_get_int(); 1777 rmaxpack = packet_get_int(); 1778 1779 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1780 ctype, rchan, rwindow, rmaxpack); 1781 1782 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1783 c = client_request_forwarded_tcpip(ctype, rchan); 1784 } else if (strcmp(ctype, "x11") == 0) { 1785 c = client_request_x11(ctype, rchan); 1786 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1787 c = client_request_agent(ctype, rchan); 1788 } 1789 /* XXX duplicate : */ 1790 if (c != NULL) { 1791 debug("confirm %s", ctype); 1792 c->remote_id = rchan; 1793 c->remote_window = rwindow; 1794 c->remote_maxpacket = rmaxpack; 1795 if (c->type != SSH_CHANNEL_CONNECTING) { 1796 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); 1797 packet_put_int(c->remote_id); 1798 packet_put_int(c->self); 1799 packet_put_int(c->local_window); 1800 packet_put_int(c->local_maxpacket); 1801 packet_send(); 1802 } 1803 } else { 1804 debug("failure %s", ctype); 1805 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); 1806 packet_put_int(rchan); 1807 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); 1808 if (!(datafellows & SSH_BUG_OPENFAILURE)) { 1809 packet_put_cstring("open failed"); 1810 packet_put_cstring(""); 1811 } 1812 packet_send(); 1813 } 1814 xfree(ctype); 1815 } 1816 static void 1817 client_input_channel_req(int type, u_int32_t seq, void *ctxt) 1818 { 1819 Channel *c = NULL; 1820 int exitval, id, reply, success = 0; 1821 char *rtype; 1822 1823 id = packet_get_int(); 1824 rtype = packet_get_string(NULL); 1825 reply = packet_get_char(); 1826 1827 debug("client_input_channel_req: channel %d rtype %s reply %d", 1828 id, rtype, reply); 1829 1830 if (id == -1) { 1831 error("client_input_channel_req: request for channel -1"); 1832 } else if ((c = channel_lookup(id)) == NULL) { 1833 error("client_input_channel_req: channel %d: " 1834 "unknown channel", id); 1835 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1836 packet_check_eom(); 1837 chan_rcvd_eow(c); 1838 } else if (strcmp(rtype, "exit-status") == 0) { 1839 exitval = packet_get_int(); 1840 if (id == session_ident) { 1841 success = 1; 1842 exit_status = exitval; 1843 } else if (c->ctl_fd == -1) { 1844 error("client_input_channel_req: unexpected channel %d", 1845 session_ident); 1846 } else { 1847 atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval)); 1848 success = 1; 1849 } 1850 packet_check_eom(); 1851 } 1852 if (reply) { 1853 packet_start(success ? 1854 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); 1855 packet_put_int(c->remote_id); 1856 packet_send(); 1857 } 1858 xfree(rtype); 1859 } 1860 static void 1861 client_input_global_request(int type, u_int32_t seq, void *ctxt) 1862 { 1863 char *rtype; 1864 int want_reply; 1865 int success = 0; 1866 1867 rtype = packet_get_string(NULL); 1868 want_reply = packet_get_char(); 1869 debug("client_input_global_request: rtype %s want_reply %d", 1870 rtype, want_reply); 1871 if (want_reply) { 1872 packet_start(success ? 1873 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); 1874 packet_send(); 1875 packet_write_wait(); 1876 } 1877 xfree(rtype); 1878 } 1879 1880 void 1881 client_session2_setup(int id, int want_tty, int want_subsystem, 1882 const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) 1883 { 1884 int len; 1885 Channel *c = NULL; 1886 1887 debug2("%s: id %d", __func__, id); 1888 1889 if ((c = channel_lookup(id)) == NULL) 1890 fatal("client_session2_setup: channel %d: unknown channel", id); 1891 1892 if (want_tty) { 1893 struct winsize ws; 1894 1895 /* Store window size in the packet. */ 1896 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) 1897 memset(&ws, 0, sizeof(ws)); 1898 1899 channel_request_start(id, "pty-req", 1); 1900 client_expect_confirm(id, "PTY allocation", 0); 1901 packet_put_cstring(term != NULL ? term : ""); 1902 packet_put_int((u_int)ws.ws_col); 1903 packet_put_int((u_int)ws.ws_row); 1904 packet_put_int((u_int)ws.ws_xpixel); 1905 packet_put_int((u_int)ws.ws_ypixel); 1906 if (tiop == NULL) 1907 tiop = get_saved_tio(); 1908 tty_make_modes(-1, tiop); 1909 packet_send(); 1910 /* XXX wait for reply */ 1911 c->client_tty = 1; 1912 } 1913 1914 /* Transfer any environment variables from client to server */ 1915 if (options.num_send_env != 0 && env != NULL) { 1916 int i, j, matched; 1917 char *name, *val; 1918 1919 debug("Sending environment."); 1920 for (i = 0; env[i] != NULL; i++) { 1921 /* Split */ 1922 name = xstrdup(env[i]); 1923 if ((val = strchr(name, '=')) == NULL) { 1924 xfree(name); 1925 continue; 1926 } 1927 *val++ = '\0'; 1928 1929 matched = 0; 1930 for (j = 0; j < options.num_send_env; j++) { 1931 if (match_pattern(name, options.send_env[j])) { 1932 matched = 1; 1933 break; 1934 } 1935 } 1936 if (!matched) { 1937 debug3("Ignored env %s", name); 1938 xfree(name); 1939 continue; 1940 } 1941 1942 debug("Sending env %s = %s", name, val); 1943 channel_request_start(id, "env", 0); 1944 packet_put_cstring(name); 1945 packet_put_cstring(val); 1946 packet_send(); 1947 xfree(name); 1948 } 1949 } 1950 1951 len = buffer_len(cmd); 1952 if (len > 0) { 1953 if (len > 900) 1954 len = 900; 1955 if (want_subsystem) { 1956 debug("Sending subsystem: %.*s", 1957 len, (u_char*)buffer_ptr(cmd)); 1958 channel_request_start(id, "subsystem", 1); 1959 client_expect_confirm(id, "subsystem", 1); 1960 } else { 1961 debug("Sending command: %.*s", 1962 len, (u_char*)buffer_ptr(cmd)); 1963 channel_request_start(id, "exec", 1); 1964 client_expect_confirm(id, "exec", 1); 1965 } 1966 packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); 1967 packet_send(); 1968 } else { 1969 channel_request_start(id, "shell", 1); 1970 client_expect_confirm(id, "shell", 1); 1971 packet_send(); 1972 } 1973 } 1974 1975 static void 1976 client_init_dispatch_20(void) 1977 { 1978 dispatch_init(&dispatch_protocol_error); 1979 1980 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 1981 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); 1982 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 1983 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 1984 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 1985 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 1986 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 1987 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 1988 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 1989 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 1990 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 1991 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 1992 1993 /* rekeying */ 1994 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 1995 1996 /* global request reply messages */ 1997 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 1998 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 1999 } 2000 2001 static void 2002 client_init_dispatch_13(void) 2003 { 2004 dispatch_init(NULL); 2005 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); 2006 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); 2007 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); 2008 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2009 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2010 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); 2011 dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status); 2012 dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data); 2013 dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data); 2014 2015 dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ? 2016 &client_input_agent_open : &deny_input_open); 2017 dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ? 2018 &x11_input_open : &deny_input_open); 2019 } 2020 2021 static void 2022 client_init_dispatch_15(void) 2023 { 2024 client_init_dispatch_13(); 2025 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); 2026 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); 2027 } 2028 2029 static void 2030 client_init_dispatch(void) 2031 { 2032 if (compat20) 2033 client_init_dispatch_20(); 2034 else if (compat13) 2035 client_init_dispatch_13(); 2036 else 2037 client_init_dispatch_15(); 2038 } 2039 2040 /* client specific fatal cleanup */ 2041 void 2042 cleanup_exit(int i) 2043 { 2044 leave_raw_mode(); 2045 leave_non_blocking(); 2046 if (options.control_path != NULL && muxserver_sock != -1) 2047 unlink(options.control_path); 2048 _exit(i); 2049 } 2050