clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.174 2006/08/01 23:22:47 stevesk 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 <stdio.h>
  82 #include <stdlib.h>
  83 #include <string.h>
  84 #include <termios.h>
  85 #include <unistd.h>
  86
  87 #include "ssh.h"
  88 #include "ssh1.h"
  89 #include "ssh2.h"
  90 #include "xmalloc.h"
  91 #include "packet.h"
  92 #include "buffer.h"
  93 #include "compat.h"
  94 #include "channels.h"
  95 #include "dispatch.h"
  96 #include "buffer.h"
  97 #include "bufaux.h"
  98 #include "key.h"
  99 #include "kex.h"
 100 #include "log.h"
 101 #include "readconf.h"
 102 #include "clientloop.h"
 103 #include "sshconnect.h"
 104 #include "authfd.h"
 105 #include "atomicio.h"
 106 #include "sshpty.h"
 107 #include "misc.h"
 108 #include "monitor_fdpass.h"
 109 #include "match.h"
 110 #include "msg.h"
 111
 112 /* import options */
 113 extern Options options;
 114
 115 /* Flag indicating that stdin should be redirected from /dev/null. */
 116 extern int stdin_null_flag;
 117
 118 /* Flag indicating that no shell has been requested */
 119 extern int no_shell_flag;
 120
 121 /* Control socket */
 122 extern int control_fd;
 123
 124 /*
 125  * Name of the host we are connecting to.  This is the name given on the
 126  * command line, or the HostName specified for the user-supplied name in a
 127  * configuration file.
 128  */
 129 extern char *host;
 130
 131 /*
 132  * Flag to indicate that we have received a window change signal which has
 133  * not yet been processed.  This will cause a message indicating the new
 134  * window size to be sent to the server a little later.  This is volatile
 135  * because this is updated in a signal handler.
 136  */
 137 static volatile sig_atomic_t received_window_change_signal = 0;
 138 static volatile sig_atomic_t received_signal = 0;
 139
 140 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 141 static int in_non_blocking_mode = 0;
 142
 143 /* Common data for the client loop code. */
 144 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 145 static int escape_char;         /* Escape character. */
 146 static int escape_pending;      /* Last character was the escape character */
 147 static int last_was_cr;         /* Last character was a newline. */
 148 static int exit_status;         /* Used to store the exit status of the command. */
 149 static int stdin_eof;           /* EOF has been encountered on standard error. */
 150 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 151 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 152 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 153 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 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 static int server_alive_timeouts = 0;
 160
 161 static void client_init_dispatch(void);
 162 int     session_ident = -1;
 163
 164 struct confirm_ctx {
 165         int want_tty;
 166         int want_subsys;
 167         int want_x_fwd;
 168         int want_agent_fwd;
 169         Buffer cmd;
 170         char *term;
 171         struct termios tio;
 172         char **env;
 173 };
 174
 175 /*XXX*/
 176 extern Kex *xxx_kex;
 177
 178 void ssh_process_session2_setup(int, int, int, Buffer *);
 179
 180 /* Restores stdin to blocking mode. */
 181
 182 static void
 183 leave_non_blocking(void)
 184 {
 185         if (in_non_blocking_mode) {
 186                 unset_nonblock(fileno(stdin));
 187                 in_non_blocking_mode = 0;
 188         }
 189 }
 190
 191 /* Puts stdin terminal in non-blocking mode. */
 192
 193 static void
 194 enter_non_blocking(void)
 195 {
 196         in_non_blocking_mode = 1;
 197         set_nonblock(fileno(stdin));
 198 }
 199
 200 /*
 201  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 202  * flag indicating that the window has changed.
 203  */
 204 /*ARGSUSED */
 205 static void
 206 window_change_handler(int sig)
 207 {
 208         received_window_change_signal = 1;
 209         signal(SIGWINCH, window_change_handler);
 210 }
 211
 212 /*
 213  * Signal handler for signals that cause the program to terminate.  These
 214  * signals must be trapped to restore terminal modes.
 215  */
 216 /*ARGSUSED */
 217 static void
 218 signal_handler(int sig)
 219 {
 220         received_signal = sig;
 221         quit_pending = 1;
 222 }
 223
 224 /*
 225  * Returns current time in seconds from Jan 1, 1970 with the maximum
 226  * available resolution.
 227  */
 228
 229 static double
 230 get_current_time(void)
 231 {
 232         struct timeval tv;
 233         gettimeofday(&tv, NULL);
 234         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 235 }
 236
 237 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 238 void
 239 client_x11_get_proto(const char *display, const char *xauth_path,
 240     u_int trusted, char **_proto, char **_data)
 241 {
 242         char cmd[1024];
 243         char line[512];
 244         char xdisplay[512];
 245         static char proto[512], data[512];
 246         FILE *f;
 247         int got_data = 0, generated = 0, do_unlink = 0, i;
 248         char *xauthdir, *xauthfile;
 249         struct stat st;
 250
 251         xauthdir = xauthfile = NULL;
 252         *_proto = proto;
 253         *_data = data;
 254         proto[0] = data[0] = '\0';
 255
 256         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 257                 debug("No xauth program.");
 258         } else {
 259                 if (display == NULL) {
 260                         debug("x11_get_proto: DISPLAY not set");
 261                         return;
 262                 }
 263                 /*
 264                  * Handle FamilyLocal case where $DISPLAY does
 265                  * not match an authorization entry.  For this we
 266                  * just try "xauth list unix:displaynum.screennum".
 267                  * XXX: "localhost" match to determine FamilyLocal
 268                  *      is not perfect.
 269                  */
 270                 if (strncmp(display, "localhost:", 10) == 0) {
 271                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 272                             display + 10);
 273                         display = xdisplay;
 274                 }
 275                 if (trusted == 0) {
 276                         xauthdir = xmalloc(MAXPATHLEN);
 277                         xauthfile = xmalloc(MAXPATHLEN);
 278                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 279                         if (mkdtemp(xauthdir) != NULL) {
 280                                 do_unlink = 1;
 281                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 282                                     xauthdir);
 283                                 snprintf(cmd, sizeof(cmd),
 284                                     "%s -f %s generate %s " SSH_X11_PROTO
 285                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 286                                     xauth_path, xauthfile, display);
 287                                 debug2("x11_get_proto: %s", cmd);
 288                                 if (system(cmd) == 0)
 289                                         generated = 1;
 290                         }
 291                 }
 292                 snprintf(cmd, sizeof(cmd),
 293                     "%s %s%s list %s 2>" _PATH_DEVNULL,
 294                     xauth_path,
 295                     generated ? "-f " : "" ,
 296                     generated ? xauthfile : "",
 297                     display);
 298                 debug2("x11_get_proto: %s", cmd);
 299                 f = popen(cmd, "r");
 300                 if (f && fgets(line, sizeof(line), f) &&
 301                     sscanf(line, "%*s %511s %511s", proto, data) == 2)
 302                         got_data = 1;
 303                 if (f)
 304                         pclose(f);
 305         }
 306
 307         if (do_unlink) {
 308                 unlink(xauthfile);
 309                 rmdir(xauthdir);
 310         }
 311         if (xauthdir)
 312                 xfree(xauthdir);
 313         if (xauthfile)
 314                 xfree(xauthfile);
 315
 316         /*
 317          * If we didn't get authentication data, just make up some
 318          * data.  The forwarding code will check the validity of the
 319          * response anyway, and substitute this data.  The X11
 320          * server, however, will ignore this fake data and use
 321          * whatever authentication mechanisms it was using otherwise
 322          * for the local connection.
 323          */
 324         if (!got_data) {
 325                 u_int32_t rnd = 0;
 326
 327                 logit("Warning: No xauth data; "
 328                     "using fake authentication data for X11 forwarding.");
 329                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 330                 for (i = 0; i < 16; i++) {
 331                         if (i % 4 == 0)
 332                                 rnd = arc4random();
 333                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 334                             rnd & 0xff);
 335                         rnd >>= 8;
 336                 }
 337         }
 338 }
 339
 340 /*
 341  * This is called when the interactive is entered.  This checks if there is
 342  * an EOF coming on stdin.  We must check this explicitly, as select() does
 343  * not appear to wake up when redirecting from /dev/null.
 344  */
 345
 346 static void
 347 client_check_initial_eof_on_stdin(void)
 348 {
 349         int len;
 350         char buf[1];
 351
 352         /*
 353          * If standard input is to be "redirected from /dev/null", we simply
 354          * mark that we have seen an EOF and send an EOF message to the
 355          * server. Otherwise, we try to read a single character; it appears
 356          * that for some files, such /dev/null, select() never wakes up for
 357          * read for this descriptor, which means that we never get EOF.  This
 358          * way we will get the EOF if stdin comes from /dev/null or similar.
 359          */
 360         if (stdin_null_flag) {
 361                 /* Fake EOF on stdin. */
 362                 debug("Sending eof.");
 363                 stdin_eof = 1;
 364                 packet_start(SSH_CMSG_EOF);
 365                 packet_send();
 366         } else {
 367                 enter_non_blocking();
 368
 369                 /* Check for immediate EOF on stdin. */
 370                 len = read(fileno(stdin), buf, 1);
 371                 if (len == 0) {
 372                         /* EOF.  Record that we have seen it and send EOF to server. */
 373                         debug("Sending eof.");
 374                         stdin_eof = 1;
 375                         packet_start(SSH_CMSG_EOF);
 376                         packet_send();
 377                 } else if (len > 0) {
 378                         /*
 379                          * Got data.  We must store the data in the buffer,
 380                          * and also process it as an escape character if
 381                          * appropriate.
 382                          */
 383                         if ((u_char) buf[0] == escape_char)
 384                                 escape_pending = 1;
 385                         else
 386                                 buffer_append(&stdin_buffer, buf, 1);
 387                 }
 388                 leave_non_blocking();
 389         }
 390 }
 391
 392
 393 /*
 394  * Make packets from buffered stdin data, and buffer them for sending to the
 395  * connection.
 396  */
 397
 398 static void
 399 client_make_packets_from_stdin_data(void)
 400 {
 401         u_int len;
 402
 403         /* Send buffered stdin data to the server. */
 404         while (buffer_len(&stdin_buffer) > 0 &&
 405             packet_not_very_much_data_to_write()) {
 406                 len = buffer_len(&stdin_buffer);
 407                 /* Keep the packets at reasonable size. */
 408                 if (len > packet_get_maxsize())
 409                         len = packet_get_maxsize();
 410                 packet_start(SSH_CMSG_STDIN_DATA);
 411                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 412                 packet_send();
 413                 buffer_consume(&stdin_buffer, len);
 414                 stdin_bytes += len;
 415                 /* If we have a pending EOF, send it now. */
 416                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 417                         packet_start(SSH_CMSG_EOF);
 418                         packet_send();
 419                 }
 420         }
 421 }
 422
 423 /*
 424  * Checks if the client window has changed, and sends a packet about it to
 425  * the server if so.  The actual change is detected elsewhere (by a software
 426  * interrupt on Unix); this just checks the flag and sends a message if
 427  * appropriate.
 428  */
 429
 430 static void
 431 client_check_window_change(void)
 432 {
 433         struct winsize ws;
 434
 435         if (! received_window_change_signal)
 436                 return;
 437         /** XXX race */
 438         received_window_change_signal = 0;
 439
 440         debug2("client_check_window_change: changed");
 441
 442         if (compat20) {
 443                 channel_send_window_changes();
 444         } else {
 445                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 446                         return;
 447                 packet_start(SSH_CMSG_WINDOW_SIZE);
 448                 packet_put_int((u_int)ws.ws_row);
 449                 packet_put_int((u_int)ws.ws_col);
 450                 packet_put_int((u_int)ws.ws_xpixel);
 451                 packet_put_int((u_int)ws.ws_ypixel);
 452                 packet_send();
 453         }
 454 }
 455
 456 static void
 457 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 458 {
 459         server_alive_timeouts = 0;
 460         client_global_request_reply_fwd(type, seq, ctxt);
 461 }
 462
 463 static void
 464 server_alive_check(void)
 465 {
 466         if (++server_alive_timeouts > options.server_alive_count_max)
 467                 packet_disconnect("Timeout, server not responding.");
 468         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 469         packet_put_cstring("keepalive@openssh.com");
 470         packet_put_char(1);     /* boolean: want reply */
 471         packet_send();
 472 }
 473
 474 /*
 475  * Waits until the client can do something (some data becomes available on
 476  * one of the file descriptors).
 477  */
 478 static void
 479 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 480     int *maxfdp, u_int *nallocp, int rekeying)
 481 {
 482         struct timeval tv, *tvp;
 483         int ret;
 484
 485         /* Add any selections by the channel mechanism. */
 486         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 487
 488         if (!compat20) {
 489                 /* Read from the connection, unless our buffers are full. */
 490                 if (buffer_len(&stdout_buffer) < buffer_high &&
 491                     buffer_len(&stderr_buffer) < buffer_high &&
 492                     channel_not_very_much_buffered_data())
 493                         FD_SET(connection_in, *readsetp);
 494                 /*
 495                  * Read from stdin, unless we have seen EOF or have very much
 496                  * buffered data to send to the server.
 497                  */
 498                 if (!stdin_eof && packet_not_very_much_data_to_write())
 499                         FD_SET(fileno(stdin), *readsetp);
 500
 501                 /* Select stdout/stderr if have data in buffer. */
 502                 if (buffer_len(&stdout_buffer) > 0)
 503                         FD_SET(fileno(stdout), *writesetp);
 504                 if (buffer_len(&stderr_buffer) > 0)
 505                         FD_SET(fileno(stderr), *writesetp);
 506         } else {
 507                 /* channel_prepare_select could have closed the last channel */
 508                 if (session_closed && !channel_still_open() &&
 509                     !packet_have_data_to_write()) {
 510                         /* clear mask since we did not call select() */
 511                         memset(*readsetp, 0, *nallocp);
 512                         memset(*writesetp, 0, *nallocp);
 513                         return;
 514                 } else {
 515                         FD_SET(connection_in, *readsetp);
 516                 }
 517         }
 518
 519         /* Select server connection if have data to write to the server. */
 520         if (packet_have_data_to_write())
 521                 FD_SET(connection_out, *writesetp);
 522
 523         if (control_fd != -1)
 524                 FD_SET(control_fd, *readsetp);
 525
 526         /*
 527          * Wait for something to happen.  This will suspend the process until
 528          * some selected descriptor can be read, written, or has some other
 529          * event pending.
 530          */
 531
 532         if (options.server_alive_interval == 0 || !compat20)
 533                 tvp = NULL;
 534         else {
 535                 tv.tv_sec = options.server_alive_interval;
 536                 tv.tv_usec = 0;
 537                 tvp = &tv;
 538         }
 539         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 540         if (ret < 0) {
 541                 char buf[100];
 542
 543                 /*
 544                  * We have to clear the select masks, because we return.
 545                  * We have to return, because the mainloop checks for the flags
 546                  * set by the signal handlers.
 547                  */
 548                 memset(*readsetp, 0, *nallocp);
 549                 memset(*writesetp, 0, *nallocp);
 550
 551                 if (errno == EINTR)
 552                         return;
 553                 /* Note: we might still have data in the buffers. */
 554                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 555                 buffer_append(&stderr_buffer, buf, strlen(buf));
 556                 quit_pending = 1;
 557         } else if (ret == 0)
 558                 server_alive_check();
 559 }
 560
 561 static void
 562 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 563 {
 564         /* Flush stdout and stderr buffers. */
 565         if (buffer_len(bout) > 0)
 566                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 567         if (buffer_len(berr) > 0)
 568                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 569
 570         leave_raw_mode();
 571
 572         /*
 573          * Free (and clear) the buffer to reduce the amount of data that gets
 574          * written to swap.
 575          */
 576         buffer_free(bin);
 577         buffer_free(bout);
 578         buffer_free(berr);
 579
 580         /* Send the suspend signal to the program itself. */
 581         kill(getpid(), SIGTSTP);
 582
 583         /* Reset window sizes in case they have changed */
 584         received_window_change_signal = 1;
 585
 586         /* OK, we have been continued by the user. Reinitialize buffers. */
 587         buffer_init(bin);
 588         buffer_init(bout);
 589         buffer_init(berr);
 590
 591         enter_raw_mode();
 592 }
 593
 594 static void
 595 client_process_net_input(fd_set *readset)
 596 {
 597         int len;
 598         char buf[8192];
 599
 600         /*
 601          * Read input from the server, and add any such data to the buffer of
 602          * the packet subsystem.
 603          */
 604         if (FD_ISSET(connection_in, readset)) {
 605                 /* Read as much as possible. */
 606                 len = read(connection_in, buf, sizeof(buf));
 607                 if (len == 0) {
 608                         /* Received EOF.  The remote host has closed the connection. */
 609                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 610                                  host);
 611                         buffer_append(&stderr_buffer, buf, strlen(buf));
 612                         quit_pending = 1;
 613                         return;
 614                 }
 615                 /*
 616                  * There is a kernel bug on Solaris that causes select to
 617                  * sometimes wake up even though there is no data available.
 618                  */
 619                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 620                         len = 0;
 621
 622                 if (len < 0) {
 623                         /* An error has encountered.  Perhaps there is a network problem. */
 624                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 625                                  host, strerror(errno));
 626                         buffer_append(&stderr_buffer, buf, strlen(buf));
 627                         quit_pending = 1;
 628                         return;
 629                 }
 630                 packet_process_incoming(buf, len);
 631         }
 632 }
 633
 634 static void
 635 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 636 {
 637         int id;
 638         Channel *c;
 639
 640         id = packet_get_int();
 641         packet_check_eom();
 642
 643         if ((c = channel_lookup(id)) == NULL) {
 644                 error("%s: no channel for id %d", __func__, id);
 645                 return;
 646         }
 647
 648         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 649                 debug2("Request suceeded on channel %d", id);
 650         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 651                 error("Request failed on channel %d", id);
 652                 channel_free(c);
 653         }
 654 }
 655
 656 static void
 657 client_extra_session2_setup(int id, void *arg)
 658 {
 659         struct confirm_ctx *cctx = arg;
 660         const char *display;
 661         Channel *c;
 662         int i;
 663
 664         if (cctx == NULL)
 665                 fatal("%s: cctx == NULL", __func__);
 666         if ((c = channel_lookup(id)) == NULL)
 667                 fatal("%s: no channel for id %d", __func__, id);
 668
 669         display = getenv("DISPLAY");
 670         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 671                 char *proto, *data;
 672                 /* Get reasonable local authentication information. */
 673                 client_x11_get_proto(display, options.xauth_location,
 674                     options.forward_x11_trusted, &proto, &data);
 675                 /* Request forwarding with authentication spoofing. */
 676                 debug("Requesting X11 forwarding with authentication spoofing.");
 677                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 678                 /* XXX wait for reply */
 679         }
 680
 681         if (cctx->want_agent_fwd && options.forward_agent) {
 682                 debug("Requesting authentication agent forwarding.");
 683                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 684                 packet_send();
 685         }
 686
 687         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 688             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 689             client_subsystem_reply);
 690
 691         c->confirm_ctx = NULL;
 692         buffer_free(&cctx->cmd);
 693         xfree(cctx->term);
 694         if (cctx->env != NULL) {
 695                 for (i = 0; cctx->env[i] != NULL; i++)
 696                         xfree(cctx->env[i]);
 697                 xfree(cctx->env);
 698         }
 699         xfree(cctx);
 700 }
 701
 702 static void
 703 client_process_control(fd_set *readset)
 704 {
 705         Buffer m;
 706         Channel *c;
 707         int client_fd, new_fd[3], ver, allowed;
 708         socklen_t addrlen;
 709         struct sockaddr_storage addr;
 710         struct confirm_ctx *cctx;
 711         char *cmd;
 712         u_int i, len, env_len, command, flags;
 713         uid_t euid;
 714         gid_t egid;
 715
 716         /*
 717          * Accept connection on control socket
 718          */
 719         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 720                 return;
 721
 722         memset(&addr, 0, sizeof(addr));
 723         addrlen = sizeof(addr);
 724         if ((client_fd = accept(control_fd,
 725             (struct sockaddr*)&addr, &addrlen)) == -1) {
 726                 error("%s accept: %s", __func__, strerror(errno));
 727                 return;
 728         }
 729
 730         if (getpeereid(client_fd, &euid, &egid) < 0) {
 731                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 732                 close(client_fd);
 733                 return;
 734         }
 735         if ((euid != 0) && (getuid() != euid)) {
 736                 error("control mode uid mismatch: peer euid %u != uid %u",
 737                     (u_int) euid, (u_int) getuid());
 738                 close(client_fd);
 739                 return;
 740         }
 741
 742         unset_nonblock(client_fd);
 743
 744         /* Read command */
 745         buffer_init(&m);
 746         if (ssh_msg_recv(client_fd, &m) == -1) {
 747                 error("%s: client msg_recv failed", __func__);
 748                 close(client_fd);
 749                 buffer_free(&m);
 750                 return;
 751         }
 752         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 753                 error("%s: wrong client version %d", __func__, ver);
 754                 buffer_free(&m);
 755                 close(client_fd);
 756                 return;
 757         }
 758
 759         allowed = 1;
 760         command = buffer_get_int(&m);
 761         flags = buffer_get_int(&m);
 762
 763         buffer_clear(&m);
 764
 765         switch (command) {
 766         case SSHMUX_COMMAND_OPEN:
 767                 if (options.control_master == SSHCTL_MASTER_ASK ||
 768                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 769                         allowed = ask_permission("Allow shared connection "
 770                             "to %s? ", host);
 771                 /* continue below */
 772                 break;
 773         case SSHMUX_COMMAND_TERMINATE:
 774                 if (options.control_master == SSHCTL_MASTER_ASK ||
 775                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 776                         allowed = ask_permission("Terminate shared connection "
 777                             "to %s? ", host);
 778                 if (allowed)
 779                         quit_pending = 1;
 780                 /* FALLTHROUGH */
 781         case SSHMUX_COMMAND_ALIVE_CHECK:
 782                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 783                 buffer_clear(&m);
 784                 buffer_put_int(&m, allowed);
 785                 buffer_put_int(&m, getpid());
 786                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 787                         error("%s: client msg_send failed", __func__);
 788                         close(client_fd);
 789                         buffer_free(&m);
 790                         return;
 791                 }
 792                 buffer_free(&m);
 793                 close(client_fd);
 794                 return;
 795         default:
 796                 error("Unsupported command %d", command);
 797                 buffer_free(&m);
 798                 close(client_fd);
 799                 return;
 800         }
 801
 802         /* Reply for SSHMUX_COMMAND_OPEN */
 803         buffer_clear(&m);
 804         buffer_put_int(&m, allowed);
 805         buffer_put_int(&m, getpid());
 806         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 807                 error("%s: client msg_send failed", __func__);
 808                 close(client_fd);
 809                 buffer_free(&m);
 810                 return;
 811         }
 812
 813         if (!allowed) {
 814                 error("Refused control connection");
 815                 close(client_fd);
 816                 buffer_free(&m);
 817                 return;
 818         }
 819
 820         buffer_clear(&m);
 821         if (ssh_msg_recv(client_fd, &m) == -1) {
 822                 error("%s: client msg_recv failed", __func__);
 823                 close(client_fd);
 824                 buffer_free(&m);
 825                 return;
 826         }
 827         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 828                 error("%s: wrong client version %d", __func__, ver);
 829                 buffer_free(&m);
 830                 close(client_fd);
 831                 return;
 832         }
 833
 834         cctx = xcalloc(1, sizeof(*cctx));
 835         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 836         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 837         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 838         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 839         cctx->term = buffer_get_string(&m, &len);
 840
 841         cmd = buffer_get_string(&m, &len);
 842         buffer_init(&cctx->cmd);
 843         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 844
 845         env_len = buffer_get_int(&m);
 846         env_len = MIN(env_len, 4096);
 847         debug3("%s: receiving %d env vars", __func__, env_len);
 848         if (env_len != 0) {
 849                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 850                 for (i = 0; i < env_len; i++)
 851                         cctx->env[i] = buffer_get_string(&m, &len);
 852                 cctx->env[i] = NULL;
 853         }
 854
 855         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 856             cctx->want_tty, cctx->want_subsys, cmd);
 857         xfree(cmd);
 858
 859         /* Gather fds from client */
 860         new_fd[0] = mm_receive_fd(client_fd);
 861         new_fd[1] = mm_receive_fd(client_fd);
 862         new_fd[2] = mm_receive_fd(client_fd);
 863
 864         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 865             new_fd[0], new_fd[1], new_fd[2]);
 866
 867         /* Try to pick up ttymodes from client before it goes raw */
 868         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 869                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 870
 871         /* This roundtrip is just for synchronisation of ttymodes */
 872         buffer_clear(&m);
 873         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 874                 error("%s: client msg_send failed", __func__);
 875                 close(client_fd);
 876                 close(new_fd[0]);
 877                 close(new_fd[1]);
 878                 close(new_fd[2]);
 879                 buffer_free(&m);
 880                 xfree(cctx->term);
 881                 if (env_len != 0) {
 882                         for (i = 0; i < env_len; i++)
 883                                 xfree(cctx->env[i]);
 884                         xfree(cctx->env);
 885                 }
 886                 return;
 887         }
 888         buffer_free(&m);
 889
 890         /* enable nonblocking unless tty */
 891         if (!isatty(new_fd[0]))
 892                 set_nonblock(new_fd[0]);
 893         if (!isatty(new_fd[1]))
 894                 set_nonblock(new_fd[1]);
 895         if (!isatty(new_fd[2]))
 896                 set_nonblock(new_fd[2]);
 897
 898         set_nonblock(client_fd);
 899
 900         c = channel_new("session", SSH_CHANNEL_OPENING,
 901             new_fd[0], new_fd[1], new_fd[2],
 902             CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
 903             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 904
 905         /* XXX */
 906         c->ctl_fd = client_fd;
 907
 908         debug3("%s: channel_new: %d", __func__, c->self);
 909
 910         channel_send_open(c->self);
 911         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 912 }
 913
 914 static void
 915 process_cmdline(void)
 916 {
 917         void (*handler)(int);
 918         char *s, *cmd, *cancel_host;
 919         int delete = 0;
 920         int local = 0;
 921         u_short cancel_port;
 922         Forward fwd;
 923
 924         leave_raw_mode();
 925         handler = signal(SIGINT, SIG_IGN);
 926         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 927         if (s == NULL)
 928                 goto out;
 929         while (*s && isspace(*s))
 930                 s++;
 931         if (*s == '-')
 932                 s++;    /* Skip cmdline '-', if any */
 933         if (*s == '\0')
 934                 goto out;
 935
 936         if (*s == 'h' || *s == 'H' || *s == '?') {
 937                 logit("Commands:");
 938                 logit("      -L[bind_address:]port:host:hostport    "
 939                     "Request local forward");
 940                 logit("      -R[bind_address:]port:host:hostport    "
 941                     "Request remote forward");
 942                 logit("      -KR[bind_address:]port                 "
 943                     "Cancel remote forward");
 944                 if (!options.permit_local_command)
 945                         goto out;
 946                 logit("      !args                                  "
 947                     "Execute local command");
 948                 goto out;
 949         }
 950
 951         if (*s == '!' && options.permit_local_command) {
 952                 s++;
 953                 ssh_local_cmd(s);
 954                 goto out;
 955         }
 956
 957         if (*s == 'K') {
 958                 delete = 1;
 959                 s++;
 960         }
 961         if (*s != 'L' && *s != 'R') {
 962                 logit("Invalid command.");
 963                 goto out;
 964         }
 965         if (*s == 'L')
 966                 local = 1;
 967         if (local && delete) {
 968                 logit("Not supported.");
 969                 goto out;
 970         }
 971         if ((!local || delete) && !compat20) {
 972                 logit("Not supported for SSH protocol version 1.");
 973                 goto out;
 974         }
 975
 976         s++;
 977         while (*s && isspace(*s))
 978                 s++;
 979
 980         if (delete) {
 981                 cancel_port = 0;
 982                 cancel_host = hpdelim(&s);      /* may be NULL */
 983                 if (s != NULL) {
 984                         cancel_port = a2port(s);
 985                         cancel_host = cleanhostname(cancel_host);
 986                 } else {
 987                         cancel_port = a2port(cancel_host);
 988                         cancel_host = NULL;
 989                 }
 990                 if (cancel_port == 0) {
 991                         logit("Bad forwarding close port");
 992                         goto out;
 993                 }
 994                 channel_request_rforward_cancel(cancel_host, cancel_port);
 995         } else {
 996                 if (!parse_forward(&fwd, s)) {
 997                         logit("Bad forwarding specification.");
 998                         goto out;
 999                 }
1000                 if (local) {
1001                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1002                             fwd.listen_port, fwd.connect_host,
1003                             fwd.connect_port, options.gateway_ports) < 0) {
1004                                 logit("Port forwarding failed.");
1005                                 goto out;
1006                         }
1007                 } else {
1008                         if (channel_request_remote_forwarding(fwd.listen_host,
1009                             fwd.listen_port, fwd.connect_host,
1010                             fwd.connect_port) < 0) {
1011                                 logit("Port forwarding failed.");
1012                                 goto out;
1013                         }
1014                 }
1015
1016                 logit("Forwarding port.");
1017         }
1018
1019 out:
1020         signal(SIGINT, handler);
1021         enter_raw_mode();
1022         if (cmd)
1023                 xfree(cmd);
1024 }
1025
1026 /* process the characters one by one */
1027 static int
1028 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1029 {
1030         char string[1024];
1031         pid_t pid;
1032         int bytes = 0;
1033         u_int i;
1034         u_char ch;
1035         char *s;
1036
1037         if (len <= 0)
1038                 return (0);
1039
1040         for (i = 0; i < (u_int)len; i++) {
1041                 /* Get one character at a time. */
1042                 ch = buf[i];
1043
1044                 if (escape_pending) {
1045                         /* We have previously seen an escape character. */
1046                         /* Clear the flag now. */
1047                         escape_pending = 0;
1048
1049                         /* Process the escaped character. */
1050                         switch (ch) {
1051                         case '.':
1052                                 /* Terminate the connection. */
1053                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1054                                 buffer_append(berr, string, strlen(string));
1055
1056                                 quit_pending = 1;
1057                                 return -1;
1058
1059                         case 'Z' - 64:
1060                                 /* Suspend the program. */
1061                                 /* Print a message to that effect to the user. */
1062                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1063                                 buffer_append(berr, string, strlen(string));
1064
1065                                 /* Restore terminal modes and suspend. */
1066                                 client_suspend_self(bin, bout, berr);
1067
1068                                 /* We have been continued. */
1069                                 continue;
1070
1071                         case 'B':
1072                                 if (compat20) {
1073                                         snprintf(string, sizeof string,
1074                                             "%cB\r\n", escape_char);
1075                                         buffer_append(berr, string,
1076                                             strlen(string));
1077                                         channel_request_start(session_ident,
1078                                             "break", 0);
1079                                         packet_put_int(1000);
1080                                         packet_send();
1081                                 }
1082                                 continue;
1083
1084                         case 'R':
1085                                 if (compat20) {
1086                                         if (datafellows & SSH_BUG_NOREKEY)
1087                                                 logit("Server does not support re-keying");
1088                                         else
1089                                                 need_rekeying = 1;
1090                                 }
1091                                 continue;
1092
1093                         case '&':
1094                                 /*
1095                                  * Detach the program (continue to serve connections,
1096                                  * but put in background and no more new connections).
1097                                  */
1098                                 /* Restore tty modes. */
1099                                 leave_raw_mode();
1100
1101                                 /* Stop listening for new connections. */
1102                                 channel_stop_listening();
1103
1104                                 snprintf(string, sizeof string,
1105                                     "%c& [backgrounded]\n", escape_char);
1106                                 buffer_append(berr, string, strlen(string));
1107
1108                                 /* Fork into background. */
1109                                 pid = fork();
1110                                 if (pid < 0) {
1111                                         error("fork: %.100s", strerror(errno));
1112                                         continue;
1113                                 }
1114                                 if (pid != 0) { /* This is the parent. */
1115                                         /* The parent just exits. */
1116                                         exit(0);
1117                                 }
1118                                 /* The child continues serving connections. */
1119                                 if (compat20) {
1120                                         buffer_append(bin, "\004", 1);
1121                                         /* fake EOF on stdin */
1122                                         return -1;
1123                                 } else if (!stdin_eof) {
1124                                         /*
1125                                          * Sending SSH_CMSG_EOF alone does not always appear
1126                                          * to be enough.  So we try to send an EOF character
1127                                          * first.
1128                                          */
1129                                         packet_start(SSH_CMSG_STDIN_DATA);
1130                                         packet_put_string("\004", 1);
1131                                         packet_send();
1132                                         /* Close stdin. */
1133                                         stdin_eof = 1;
1134                                         if (buffer_len(bin) == 0) {
1135                                                 packet_start(SSH_CMSG_EOF);
1136                                                 packet_send();
1137                                         }
1138                                 }
1139                                 continue;
1140
1141                         case '?':
1142                                 snprintf(string, sizeof string,
1143 "%c?\r\n\
1144 Supported escape sequences:\r\n\
1145 %c.  - terminate connection\r\n\
1146 %cB  - send a BREAK to the remote system\r\n\
1147 %cC  - open a command line\r\n\
1148 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1149 %c^Z - suspend ssh\r\n\
1150 %c#  - list forwarded connections\r\n\
1151 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1152 %c?  - this message\r\n\
1153 %c%c  - send the escape character by typing it twice\r\n\
1154 (Note that escapes are only recognized immediately after newline.)\r\n",
1155                                     escape_char, escape_char, escape_char, escape_char,
1156                                     escape_char, escape_char, escape_char, escape_char,
1157                                     escape_char, escape_char, escape_char);
1158                                 buffer_append(berr, string, strlen(string));
1159                                 continue;
1160
1161                         case '#':
1162                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1163                                 buffer_append(berr, string, strlen(string));
1164                                 s = channel_open_message();
1165                                 buffer_append(berr, s, strlen(s));
1166                                 xfree(s);
1167                                 continue;
1168
1169                         case 'C':
1170                                 process_cmdline();
1171                                 continue;
1172
1173                         default:
1174                                 if (ch != escape_char) {
1175                                         buffer_put_char(bin, escape_char);
1176                                         bytes++;
1177                                 }
1178                                 /* Escaped characters fall through here */
1179                                 break;
1180                         }
1181                 } else {
1182                         /*
1183                          * The previous character was not an escape char. Check if this
1184                          * is an escape.
1185                          */
1186                         if (last_was_cr && ch == escape_char) {
1187                                 /* It is. Set the flag and continue to next character. */
1188                                 escape_pending = 1;
1189                                 continue;
1190                         }
1191                 }
1192
1193                 /*
1194                  * Normal character.  Record whether it was a newline,
1195                  * and append it to the buffer.
1196                  */
1197                 last_was_cr = (ch == '\r' || ch == '\n');
1198                 buffer_put_char(bin, ch);
1199                 bytes++;
1200         }
1201         return bytes;
1202 }
1203
1204 static void
1205 client_process_input(fd_set *readset)
1206 {
1207         int len;
1208         char buf[8192];
1209
1210         /* Read input from stdin. */
1211         if (FD_ISSET(fileno(stdin), readset)) {
1212                 /* Read as much as possible. */
1213                 len = read(fileno(stdin), buf, sizeof(buf));
1214                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1215                         return;         /* we'll try again later */
1216                 if (len <= 0) {
1217                         /*
1218                          * Received EOF or error.  They are treated
1219                          * similarly, except that an error message is printed
1220                          * if it was an error condition.
1221                          */
1222                         if (len < 0) {
1223                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1224                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1225                         }
1226                         /* Mark that we have seen EOF. */
1227                         stdin_eof = 1;
1228                         /*
1229                          * Send an EOF message to the server unless there is
1230                          * data in the buffer.  If there is data in the
1231                          * buffer, no message will be sent now.  Code
1232                          * elsewhere will send the EOF when the buffer
1233                          * becomes empty if stdin_eof is set.
1234                          */
1235                         if (buffer_len(&stdin_buffer) == 0) {
1236                                 packet_start(SSH_CMSG_EOF);
1237                                 packet_send();
1238                         }
1239                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1240                         /*
1241                          * Normal successful read, and no escape character.
1242                          * Just append the data to buffer.
1243                          */
1244                         buffer_append(&stdin_buffer, buf, len);
1245                 } else {
1246                         /*
1247                          * Normal, successful read.  But we have an escape character
1248                          * and have to process the characters one by one.
1249                          */
1250                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1251                             &stderr_buffer, buf, len) == -1)
1252                                 return;
1253                 }
1254         }
1255 }
1256
1257 static void
1258 client_process_output(fd_set *writeset)
1259 {
1260         int len;
1261         char buf[100];
1262
1263         /* Write buffered output to stdout. */
1264         if (FD_ISSET(fileno(stdout), writeset)) {
1265                 /* Write as much data as possible. */
1266                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1267                     buffer_len(&stdout_buffer));
1268                 if (len <= 0) {
1269                         if (errno == EINTR || errno == EAGAIN)
1270                                 len = 0;
1271                         else {
1272                                 /*
1273                                  * An error or EOF was encountered.  Put an
1274                                  * error message to stderr buffer.
1275                                  */
1276                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1277                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1278                                 quit_pending = 1;
1279                                 return;
1280                         }
1281                 }
1282                 /* Consume printed data from the buffer. */
1283                 buffer_consume(&stdout_buffer, len);
1284                 stdout_bytes += len;
1285         }
1286         /* Write buffered output to stderr. */
1287         if (FD_ISSET(fileno(stderr), writeset)) {
1288                 /* Write as much data as possible. */
1289                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1290                     buffer_len(&stderr_buffer));
1291                 if (len <= 0) {
1292                         if (errno == EINTR || errno == EAGAIN)
1293                                 len = 0;
1294                         else {
1295                                 /* EOF or error, but can't even print error message. */
1296                                 quit_pending = 1;
1297                                 return;
1298                         }
1299                 }
1300                 /* Consume printed characters from the buffer. */
1301                 buffer_consume(&stderr_buffer, len);
1302                 stderr_bytes += len;
1303         }
1304 }
1305
1306 /*
1307  * Get packets from the connection input buffer, and process them as long as
1308  * there are packets available.
1309  *
1310  * Any unknown packets received during the actual
1311  * session cause the session to terminate.  This is
1312  * intended to make debugging easier since no
1313  * confirmations are sent.  Any compatible protocol
1314  * extensions must be negotiated during the
1315  * preparatory phase.
1316  */
1317
1318 static void
1319 client_process_buffered_input_packets(void)
1320 {
1321         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1322 }
1323
1324 /* scan buf[] for '~' before sending data to the peer */
1325
1326 static int
1327 simple_escape_filter(Channel *c, char *buf, int len)
1328 {
1329         /* XXX we assume c->extended is writeable */
1330         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1331 }
1332
1333 static void
1334 client_channel_closed(int id, void *arg)
1335 {
1336         channel_cancel_cleanup(id);
1337         session_closed = 1;
1338         leave_raw_mode();
1339 }
1340
1341 /*
1342  * Implements the interactive session with the server.  This is called after
1343  * the user has been authenticated, and a command has been started on the
1344  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1345  * used as an escape character for terminating or suspending the session.
1346  */
1347
1348 int
1349 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1350 {
1351         fd_set *readset = NULL, *writeset = NULL;
1352         double start_time, total_time;
1353         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1354         u_int nalloc = 0;
1355         char buf[100];
1356
1357         debug("Entering interactive session.");
1358
1359         start_time = get_current_time();
1360
1361         /* Initialize variables. */
1362         escape_pending = 0;
1363         last_was_cr = 1;
1364         exit_status = -1;
1365         stdin_eof = 0;
1366         buffer_high = 64 * 1024;
1367         connection_in = packet_get_connection_in();
1368         connection_out = packet_get_connection_out();
1369         max_fd = MAX(connection_in, connection_out);
1370         if (control_fd != -1)
1371                 max_fd = MAX(max_fd, control_fd);
1372
1373         if (!compat20) {
1374                 /* enable nonblocking unless tty */
1375                 if (!isatty(fileno(stdin)))
1376                         set_nonblock(fileno(stdin));
1377                 if (!isatty(fileno(stdout)))
1378                         set_nonblock(fileno(stdout));
1379                 if (!isatty(fileno(stderr)))
1380                         set_nonblock(fileno(stderr));
1381                 max_fd = MAX(max_fd, fileno(stdin));
1382                 max_fd = MAX(max_fd, fileno(stdout));
1383                 max_fd = MAX(max_fd, fileno(stderr));
1384         }
1385         stdin_bytes = 0;
1386         stdout_bytes = 0;
1387         stderr_bytes = 0;
1388         quit_pending = 0;
1389         escape_char = escape_char_arg;
1390
1391         /* Initialize buffers. */
1392         buffer_init(&stdin_buffer);
1393         buffer_init(&stdout_buffer);
1394         buffer_init(&stderr_buffer);
1395
1396         client_init_dispatch();
1397
1398         /*
1399          * Set signal handlers, (e.g. to restore non-blocking mode)
1400          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1401          */
1402         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1403                 signal(SIGHUP, signal_handler);
1404         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1405                 signal(SIGINT, signal_handler);
1406         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1407                 signal(SIGQUIT, signal_handler);
1408         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1409                 signal(SIGTERM, signal_handler);
1410         signal(SIGWINCH, window_change_handler);
1411
1412         if (have_pty)
1413                 enter_raw_mode();
1414
1415         if (compat20) {
1416                 session_ident = ssh2_chan_id;
1417                 if (escape_char != SSH_ESCAPECHAR_NONE)
1418                         channel_register_filter(session_ident,
1419                             simple_escape_filter, NULL);
1420                 if (session_ident != -1)
1421                         channel_register_cleanup(session_ident,
1422                             client_channel_closed, 0);
1423         } else {
1424                 /* Check if we should immediately send eof on stdin. */
1425                 client_check_initial_eof_on_stdin();
1426         }
1427
1428         /* Main loop of the client for the interactive session mode. */
1429         while (!quit_pending) {
1430
1431                 /* Process buffered packets sent by the server. */
1432                 client_process_buffered_input_packets();
1433
1434                 if (compat20 && session_closed && !channel_still_open())
1435                         break;
1436
1437                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1438
1439                 if (rekeying) {
1440                         debug("rekeying in progress");
1441                 } else {
1442                         /*
1443                          * Make packets of buffered stdin data, and buffer
1444                          * them for sending to the server.
1445                          */
1446                         if (!compat20)
1447                                 client_make_packets_from_stdin_data();
1448
1449                         /*
1450                          * Make packets from buffered channel data, and
1451                          * enqueue them for sending to the server.
1452                          */
1453                         if (packet_not_very_much_data_to_write())
1454                                 channel_output_poll();
1455
1456                         /*
1457                          * Check if the window size has changed, and buffer a
1458                          * message about it to the server if so.
1459                          */
1460                         client_check_window_change();
1461
1462                         if (quit_pending)
1463                                 break;
1464                 }
1465                 /*
1466                  * Wait until we have something to do (something becomes
1467                  * available on one of the descriptors).
1468                  */
1469                 max_fd2 = max_fd;
1470                 client_wait_until_can_do_something(&readset, &writeset,
1471                     &max_fd2, &nalloc, rekeying);
1472
1473                 if (quit_pending)
1474                         break;
1475
1476                 /* Do channel operations unless rekeying in progress. */
1477                 if (!rekeying) {
1478                         channel_after_select(readset, writeset);
1479                         if (need_rekeying || packet_need_rekeying()) {
1480                                 debug("need rekeying");
1481                                 xxx_kex->done = 0;
1482                                 kex_send_kexinit(xxx_kex);
1483                                 need_rekeying = 0;
1484                         }
1485                 }
1486
1487                 /* Buffer input from the connection.  */
1488                 client_process_net_input(readset);
1489
1490                 /* Accept control connections.  */
1491                 client_process_control(readset);
1492
1493                 if (quit_pending)
1494                         break;
1495
1496                 if (!compat20) {
1497                         /* Buffer data from stdin */
1498                         client_process_input(readset);
1499                         /*
1500                          * Process output to stdout and stderr.  Output to
1501                          * the connection is processed elsewhere (above).
1502                          */
1503                         client_process_output(writeset);
1504                 }
1505
1506                 /* Send as much buffered packet data as possible to the sender. */
1507                 if (FD_ISSET(connection_out, writeset))
1508                         packet_write_poll();
1509         }
1510         if (readset)
1511                 xfree(readset);
1512         if (writeset)
1513                 xfree(writeset);
1514
1515         /* Terminate the session. */
1516
1517         /* Stop watching for window change. */
1518         signal(SIGWINCH, SIG_DFL);
1519
1520         channel_free_all();
1521
1522         if (have_pty)
1523                 leave_raw_mode();
1524
1525         /* restore blocking io */
1526         if (!isatty(fileno(stdin)))
1527                 unset_nonblock(fileno(stdin));
1528         if (!isatty(fileno(stdout)))
1529                 unset_nonblock(fileno(stdout));
1530         if (!isatty(fileno(stderr)))
1531                 unset_nonblock(fileno(stderr));
1532
1533         /*
1534          * If there was no shell or command requested, there will be no remote
1535          * exit status to be returned.  In that case, clear error code if the
1536          * connection was deliberately terminated at this end.
1537          */
1538         if (no_shell_flag && received_signal == SIGTERM) {
1539                 received_signal = 0;
1540                 exit_status = 0;
1541         }
1542
1543         if (received_signal)
1544                 fatal("Killed by signal %d.", (int) received_signal);
1545
1546         /*
1547          * In interactive mode (with pseudo tty) display a message indicating
1548          * that the connection has been closed.
1549          */
1550         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1551                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1552                 buffer_append(&stderr_buffer, buf, strlen(buf));
1553         }
1554
1555         /* Output any buffered data for stdout. */
1556         while (buffer_len(&stdout_buffer) > 0) {
1557                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1558                     buffer_len(&stdout_buffer));
1559                 if (len <= 0) {
1560                         error("Write failed flushing stdout buffer.");
1561                         break;
1562                 }
1563                 buffer_consume(&stdout_buffer, len);
1564                 stdout_bytes += len;
1565         }
1566
1567         /* Output any buffered data for stderr. */
1568         while (buffer_len(&stderr_buffer) > 0) {
1569                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1570                     buffer_len(&stderr_buffer));
1571                 if (len <= 0) {
1572                         error("Write failed flushing stderr buffer.");
1573                         break;
1574                 }
1575                 buffer_consume(&stderr_buffer, len);
1576                 stderr_bytes += len;
1577         }
1578
1579         /* Clear and free any buffers. */
1580         memset(buf, 0, sizeof(buf));
1581         buffer_free(&stdin_buffer);
1582         buffer_free(&stdout_buffer);
1583         buffer_free(&stderr_buffer);
1584
1585         /* Report bytes transferred, and transfer rates. */
1586         total_time = get_current_time() - start_time;
1587         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1588             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1589         if (total_time > 0)
1590                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1591                     stdin_bytes / total_time, stdout_bytes / total_time,
1592                     stderr_bytes / total_time);
1593
1594         /* Return the exit status of the program. */
1595         debug("Exit status %d", exit_status);
1596         return exit_status;
1597 }
1598
1599 /*********/
1600
1601 static void
1602 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1603 {
1604         u_int data_len;
1605         char *data = packet_get_string(&data_len);
1606         packet_check_eom();
1607         buffer_append(&stdout_buffer, data, data_len);
1608         memset(data, 0, data_len);
1609         xfree(data);
1610 }
1611 static void
1612 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1613 {
1614         u_int data_len;
1615         char *data = packet_get_string(&data_len);
1616         packet_check_eom();
1617         buffer_append(&stderr_buffer, data, data_len);
1618         memset(data, 0, data_len);
1619         xfree(data);
1620 }
1621 static void
1622 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1623 {
1624         exit_status = packet_get_int();
1625         packet_check_eom();
1626         /* Acknowledge the exit. */
1627         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1628         packet_send();
1629         /*
1630          * Must wait for packet to be sent since we are
1631          * exiting the loop.
1632          */
1633         packet_write_wait();
1634         /* Flag that we want to exit. */
1635         quit_pending = 1;
1636 }
1637 static void
1638 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1639 {
1640         Channel *c = NULL;
1641         int remote_id, sock;
1642
1643         /* Read the remote channel number from the message. */
1644         remote_id = packet_get_int();
1645         packet_check_eom();
1646
1647         /*
1648          * Get a connection to the local authentication agent (this may again
1649          * get forwarded).
1650          */
1651         sock = ssh_get_authentication_socket();
1652
1653         /*
1654          * If we could not connect the agent, send an error message back to
1655          * the server. This should never happen unless the agent dies,
1656          * because authentication forwarding is only enabled if we have an
1657          * agent.
1658          */
1659         if (sock >= 0) {
1660                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1661                     -1, 0, 0, 0, "authentication agent connection", 1);
1662                 c->remote_id = remote_id;
1663                 c->force_drain = 1;
1664         }
1665         if (c == NULL) {
1666                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1667                 packet_put_int(remote_id);
1668         } else {
1669                 /* Send a confirmation to the remote host. */
1670                 debug("Forwarding authentication connection.");
1671                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1672                 packet_put_int(remote_id);
1673                 packet_put_int(c->self);
1674         }
1675         packet_send();
1676 }
1677
1678 static Channel *
1679 client_request_forwarded_tcpip(const char *request_type, int rchan)
1680 {
1681         Channel *c = NULL;
1682         char *listen_address, *originator_address;
1683         int listen_port, originator_port;
1684         int sock;
1685
1686         /* Get rest of the packet */
1687         listen_address = packet_get_string(NULL);
1688         listen_port = packet_get_int();
1689         originator_address = packet_get_string(NULL);
1690         originator_port = packet_get_int();
1691         packet_check_eom();
1692
1693         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1694             listen_address, listen_port, originator_address, originator_port);
1695
1696         sock = channel_connect_by_listen_address(listen_port);
1697         if (sock < 0) {
1698                 xfree(originator_address);
1699                 xfree(listen_address);
1700                 return NULL;
1701         }
1702         c = channel_new("forwarded-tcpip",
1703             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1704             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1705             originator_address, 1);
1706         xfree(originator_address);
1707         xfree(listen_address);
1708         return c;
1709 }
1710
1711 static Channel *
1712 client_request_x11(const char *request_type, int rchan)
1713 {
1714         Channel *c = NULL;
1715         char *originator;
1716         int originator_port;
1717         int sock;
1718
1719         if (!options.forward_x11) {
1720                 error("Warning: ssh server tried X11 forwarding.");
1721                 error("Warning: this is probably a break-in attempt by a malicious server.");
1722                 return NULL;
1723         }
1724         originator = packet_get_string(NULL);
1725         if (datafellows & SSH_BUG_X11FWD) {
1726                 debug2("buggy server: x11 request w/o originator_port");
1727                 originator_port = 0;
1728         } else {
1729                 originator_port = packet_get_int();
1730         }
1731         packet_check_eom();
1732         /* XXX check permission */
1733         debug("client_request_x11: request from %s %d", originator,
1734             originator_port);
1735         xfree(originator);
1736         sock = x11_connect_display();
1737         if (sock < 0)
1738                 return NULL;
1739         c = channel_new("x11",
1740             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1741             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1742         c->force_drain = 1;
1743         return c;
1744 }
1745
1746 static Channel *
1747 client_request_agent(const char *request_type, int rchan)
1748 {
1749         Channel *c = NULL;
1750         int sock;
1751
1752         if (!options.forward_agent) {
1753                 error("Warning: ssh server tried agent forwarding.");
1754                 error("Warning: this is probably a break-in attempt by a malicious server.");
1755                 return NULL;
1756         }
1757         sock =  ssh_get_authentication_socket();
1758         if (sock < 0)
1759                 return NULL;
1760         c = channel_new("authentication agent connection",
1761             SSH_CHANNEL_OPEN, sock, sock, -1,
1762             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1763             "authentication agent connection", 1);
1764         c->force_drain = 1;
1765         return c;
1766 }
1767
1768 /* XXXX move to generic input handler */
1769 static void
1770 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1771 {
1772         Channel *c = NULL;
1773         char *ctype;
1774         int rchan;
1775         u_int rmaxpack, rwindow, len;
1776
1777         ctype = packet_get_string(&len);
1778         rchan = packet_get_int();
1779         rwindow = packet_get_int();
1780         rmaxpack = packet_get_int();
1781
1782         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1783             ctype, rchan, rwindow, rmaxpack);
1784
1785         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1786                 c = client_request_forwarded_tcpip(ctype, rchan);
1787         } else if (strcmp(ctype, "x11") == 0) {
1788                 c = client_request_x11(ctype, rchan);
1789         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1790                 c = client_request_agent(ctype, rchan);
1791         }
1792 /* XXX duplicate : */
1793         if (c != NULL) {
1794                 debug("confirm %s", ctype);
1795                 c->remote_id = rchan;
1796                 c->remote_window = rwindow;
1797                 c->remote_maxpacket = rmaxpack;
1798                 if (c->type != SSH_CHANNEL_CONNECTING) {
1799                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1800                         packet_put_int(c->remote_id);
1801                         packet_put_int(c->self);
1802                         packet_put_int(c->local_window);
1803                         packet_put_int(c->local_maxpacket);
1804                         packet_send();
1805                 }
1806         } else {
1807                 debug("failure %s", ctype);
1808                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1809                 packet_put_int(rchan);
1810                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1811                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1812                         packet_put_cstring("open failed");
1813                         packet_put_cstring("");
1814                 }
1815                 packet_send();
1816         }
1817         xfree(ctype);
1818 }
1819 static void
1820 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1821 {
1822         Channel *c = NULL;
1823         int exitval, id, reply, success = 0;
1824         char *rtype;
1825
1826         id = packet_get_int();
1827         rtype = packet_get_string(NULL);
1828         reply = packet_get_char();
1829
1830         debug("client_input_channel_req: channel %d rtype %s reply %d",
1831             id, rtype, reply);
1832
1833         if (id == -1) {
1834                 error("client_input_channel_req: request for channel -1");
1835         } else if ((c = channel_lookup(id)) == NULL) {
1836                 error("client_input_channel_req: channel %d: unknown channel", id);
1837         } else if (strcmp(rtype, "exit-status") == 0) {
1838                 exitval = packet_get_int();
1839                 if (id == session_ident) {
1840                         success = 1;
1841                         exit_status = exitval;
1842                 } else if (c->ctl_fd == -1) {
1843                         error("client_input_channel_req: unexpected channel %d",
1844                             session_ident);
1845                 } else {
1846                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1847                         success = 1;
1848                 }
1849                 packet_check_eom();
1850         }
1851         if (reply) {
1852                 packet_start(success ?
1853                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1854                 packet_put_int(id);
1855                 packet_send();
1856         }
1857         xfree(rtype);
1858 }
1859 static void
1860 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1861 {
1862         char *rtype;
1863         int want_reply;
1864         int success = 0;
1865
1866         rtype = packet_get_string(NULL);
1867         want_reply = packet_get_char();
1868         debug("client_input_global_request: rtype %s want_reply %d",
1869             rtype, want_reply);
1870         if (want_reply) {
1871                 packet_start(success ?
1872                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1873                 packet_send();
1874                 packet_write_wait();
1875         }
1876         xfree(rtype);
1877 }
1878
1879 void
1880 client_session2_setup(int id, int want_tty, int want_subsystem,
1881     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1882     dispatch_fn *subsys_repl)
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                 struct termios tio;
1895
1896                 /* Store window size in the packet. */
1897                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1898                         memset(&ws, 0, sizeof(ws));
1899
1900                 channel_request_start(id, "pty-req", 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                 tio = get_saved_tio();
1907                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1908                 packet_send();
1909                 /* XXX wait for reply */
1910                 c->client_tty = 1;
1911         }
1912
1913         /* Transfer any environment variables from client to server */
1914         if (options.num_send_env != 0 && env != NULL) {
1915                 int i, j, matched;
1916                 char *name, *val;
1917
1918                 debug("Sending environment.");
1919                 for (i = 0; env[i] != NULL; i++) {
1920                         /* Split */
1921                         name = xstrdup(env[i]);
1922                         if ((val = strchr(name, '=')) == NULL) {
1923                                 xfree(name);
1924                                 continue;
1925                         }
1926                         *val++ = '\0';
1927
1928                         matched = 0;
1929                         for (j = 0; j < options.num_send_env; j++) {
1930                                 if (match_pattern(name, options.send_env[j])) {
1931                                         matched = 1;
1932                                         break;
1933                                 }
1934                         }
1935                         if (!matched) {
1936                                 debug3("Ignored env %s", name);
1937                                 xfree(name);
1938                                 continue;
1939                         }
1940
1941                         debug("Sending env %s = %s", name, val);
1942                         channel_request_start(id, "env", 0);
1943                         packet_put_cstring(name);
1944                         packet_put_cstring(val);
1945                         packet_send();
1946                         xfree(name);
1947                 }
1948         }
1949
1950         len = buffer_len(cmd);
1951         if (len > 0) {
1952                 if (len > 900)
1953                         len = 900;
1954                 if (want_subsystem) {
1955                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
1956                         channel_request_start(id, "subsystem", subsys_repl != NULL);
1957                         if (subsys_repl != NULL) {
1958                                 /* register callback for reply */
1959                                 /* XXX we assume that client_loop has already been called */
1960                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
1961                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
1962                         }
1963                 } else {
1964                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
1965                         channel_request_start(id, "exec", 0);
1966                 }
1967                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
1968                 packet_send();
1969         } else {
1970                 channel_request_start(id, "shell", 0);
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_GLOBAL_REQUEST, &client_input_global_request);
1990
1991         /* rekeying */
1992         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1993
1994         /* global request reply messages */
1995         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1996         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1997 }
1998 static void
1999 client_init_dispatch_13(void)
2000 {
2001         dispatch_init(NULL);
2002         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2003         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2004         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2005         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2006         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2007         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2008         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2009         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2010         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2011
2012         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2013             &client_input_agent_open : &deny_input_open);
2014         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2015             &x11_input_open : &deny_input_open);
2016 }
2017 static void
2018 client_init_dispatch_15(void)
2019 {
2020         client_init_dispatch_13();
2021         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2022         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2023 }
2024 static void
2025 client_init_dispatch(void)
2026 {
2027         if (compat20)
2028                 client_init_dispatch_20();
2029         else if (compat13)
2030                 client_init_dispatch_13();
2031         else
2032                 client_init_dispatch_15();
2033 }
2034
2035 /* client specific fatal cleanup */
2036 void
2037 cleanup_exit(int i)
2038 {
2039         leave_raw_mode();
2040         leave_non_blocking();
2041         if (options.control_path != NULL && control_fd != -1)
2042                 unlink(options.control_path);
2043         _exit(i);
2044 }