openssh/clientloop.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * The main loop for the interactive session (client side).
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  *
  13  *
  14  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  *
  37  * SSH2 support added by Markus Friedl.
  38  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  59  */
  60
  61 #include "includes.h"
  62 RCSID("$OpenBSD: clientloop.c,v 1.100 2002/04/22 21:04:52 markus Exp $");
  63
  64 #include "ssh.h"
  65 #include "ssh1.h"
  66 #include "ssh2.h"
  67 #include "xmalloc.h"
  68 #include "packet.h"
  69 #include "buffer.h"
  70 #include "compat.h"
  71 #include "channels.h"
  72 #include "dispatch.h"
  73 #include "buffer.h"
  74 #include "bufaux.h"
  75 #include "key.h"
  76 #include "kex.h"
  77 #include "log.h"
  78 #include "readconf.h"
  79 #include "clientloop.h"
  80 #include "authfd.h"
  81 #include "atomicio.h"
  82 #include "sshtty.h"
  83 #include "misc.h"
  84 #include "readpass.h"
  85
  86 /* import options */
  87 extern Options options;
  88
  89 /* Flag indicating that stdin should be redirected from /dev/null. */
  90 extern int stdin_null_flag;
  91
  92 /*
  93  * Name of the host we are connecting to.  This is the name given on the
  94  * command line, or the HostName specified for the user-supplied name in a
  95  * configuration file.
  96  */
  97 extern char *host;
  98
  99 /*
 100  * Flag to indicate that we have received a window change signal which has
 101  * not yet been processed.  This will cause a message indicating the new
 102  * window size to be sent to the server a little later.  This is volatile
 103  * because this is updated in a signal handler.
 104  */
 105 static volatile sig_atomic_t received_window_change_signal = 0;
 106 static volatile sig_atomic_t received_signal = 0;
 107
 108 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
 109 static int in_non_blocking_mode = 0;
 110
 111 /* Common data for the client loop code. */
 112 static int quit_pending;        /* Set to non-zero to quit the client loop. */
 113 static int escape_char;         /* Escape character. */
 114 static int escape_pending;      /* Last character was the escape character */
 115 static int last_was_cr;         /* Last character was a newline. */
 116 static int exit_status;         /* Used to store the exit status of the command. */
 117 static int stdin_eof;           /* EOF has been encountered on standard error. */
 118 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 119 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 120 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 121 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 122 static u_int buffer_high;/* Soft max buffer size. */
 123 static int connection_in;       /* Connection to server (input). */
 124 static int connection_out;      /* Connection to server (output). */
 125 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 126 static int session_closed = 0;  /* In SSH2: login session closed. */
 127
 128 static void client_init_dispatch(void);
 129 int     session_ident = -1;
 130
 131 /*XXX*/
 132 extern Kex *xxx_kex;
 133
 134 /* Restores stdin to blocking mode. */
 135
 136 static void
 137 leave_non_blocking(void)
 138 {
 139         if (in_non_blocking_mode) {
 140                 (void) fcntl(fileno(stdin), F_SETFL, 0);
 141                 in_non_blocking_mode = 0;
 142                 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
 143         }
 144 }
 145
 146 /* Puts stdin terminal in non-blocking mode. */
 147
 148 static void
 149 enter_non_blocking(void)
 150 {
 151         in_non_blocking_mode = 1;
 152         (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
 153         fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
 154 }
 155
 156 /*
 157  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 158  * flag indicating that the window has changed.
 159  */
 160
 161 static void
 162 window_change_handler(int sig)
 163 {
 164         received_window_change_signal = 1;
 165         signal(SIGWINCH, window_change_handler);
 166 }
 167
 168 /*
 169  * Signal handler for signals that cause the program to terminate.  These
 170  * signals must be trapped to restore terminal modes.
 171  */
 172
 173 static void
 174 signal_handler(int sig)
 175 {
 176         received_signal = sig;
 177         quit_pending = 1;
 178 }
 179
 180 /*
 181  * Returns current time in seconds from Jan 1, 1970 with the maximum
 182  * available resolution.
 183  */
 184
 185 static double
 186 get_current_time(void)
 187 {
 188         struct timeval tv;
 189         gettimeofday(&tv, NULL);
 190         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 191 }
 192
 193 /*
 194  * This is called when the interactive is entered.  This checks if there is
 195  * an EOF coming on stdin.  We must check this explicitly, as select() does
 196  * not appear to wake up when redirecting from /dev/null.
 197  */
 198
 199 static void
 200 client_check_initial_eof_on_stdin(void)
 201 {
 202         int len;
 203         char buf[1];
 204
 205         /*
 206          * If standard input is to be "redirected from /dev/null", we simply
 207          * mark that we have seen an EOF and send an EOF message to the
 208          * server. Otherwise, we try to read a single character; it appears
 209          * that for some files, such /dev/null, select() never wakes up for
 210          * read for this descriptor, which means that we never get EOF.  This
 211          * way we will get the EOF if stdin comes from /dev/null or similar.
 212          */
 213         if (stdin_null_flag) {
 214                 /* Fake EOF on stdin. */
 215                 debug("Sending eof.");
 216                 stdin_eof = 1;
 217                 packet_start(SSH_CMSG_EOF);
 218                 packet_send();
 219         } else {
 220                 enter_non_blocking();
 221
 222                 /* Check for immediate EOF on stdin. */
 223                 len = read(fileno(stdin), buf, 1);
 224                 if (len == 0) {
 225                         /* EOF.  Record that we have seen it and send EOF to server. */
 226                         debug("Sending eof.");
 227                         stdin_eof = 1;
 228                         packet_start(SSH_CMSG_EOF);
 229                         packet_send();
 230                 } else if (len > 0) {
 231                         /*
 232                          * Got data.  We must store the data in the buffer,
 233                          * and also process it as an escape character if
 234                          * appropriate.
 235                          */
 236                         if ((u_char) buf[0] == escape_char)
 237                                 escape_pending = 1;
 238                         else
 239                                 buffer_append(&stdin_buffer, buf, 1);
 240                 }
 241                 leave_non_blocking();
 242         }
 243 }
 244
 245
 246 /*
 247  * Make packets from buffered stdin data, and buffer them for sending to the
 248  * connection.
 249  */
 250
 251 static void
 252 client_make_packets_from_stdin_data(void)
 253 {
 254         u_int len;
 255
 256         /* Send buffered stdin data to the server. */
 257         while (buffer_len(&stdin_buffer) > 0 &&
 258             packet_not_very_much_data_to_write()) {
 259                 len = buffer_len(&stdin_buffer);
 260                 /* Keep the packets at reasonable size. */
 261                 if (len > packet_get_maxsize())
 262                         len = packet_get_maxsize();
 263                 packet_start(SSH_CMSG_STDIN_DATA);
 264                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 265                 packet_send();
 266                 buffer_consume(&stdin_buffer, len);
 267                 stdin_bytes += len;
 268                 /* If we have a pending EOF, send it now. */
 269                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 270                         packet_start(SSH_CMSG_EOF);
 271                         packet_send();
 272                 }
 273         }
 274 }
 275
 276 /*
 277  * Checks if the client window has changed, and sends a packet about it to
 278  * the server if so.  The actual change is detected elsewhere (by a software
 279  * interrupt on Unix); this just checks the flag and sends a message if
 280  * appropriate.
 281  */
 282
 283 static void
 284 client_check_window_change(void)
 285 {
 286         struct winsize ws;
 287
 288         if (! received_window_change_signal)
 289                 return;
 290         /** XXX race */
 291         received_window_change_signal = 0;
 292
 293         if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 294                 return;
 295
 296         debug2("client_check_window_change: changed");
 297
 298         if (compat20) {
 299                 channel_request_start(session_ident, "window-change", 0);
 300                 packet_put_int(ws.ws_col);
 301                 packet_put_int(ws.ws_row);
 302                 packet_put_int(ws.ws_xpixel);
 303                 packet_put_int(ws.ws_ypixel);
 304                 packet_send();
 305         } else {
 306                 packet_start(SSH_CMSG_WINDOW_SIZE);
 307                 packet_put_int(ws.ws_row);
 308                 packet_put_int(ws.ws_col);
 309                 packet_put_int(ws.ws_xpixel);
 310                 packet_put_int(ws.ws_ypixel);
 311                 packet_send();
 312         }
 313 }
 314
 315 /*
 316  * Waits until the client can do something (some data becomes available on
 317  * one of the file descriptors).
 318  */
 319
 320 static void
 321 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 322     int *maxfdp, int *nallocp, int rekeying)
 323 {
 324         /* Add any selections by the channel mechanism. */
 325         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 326
 327         if (!compat20) {
 328                 /* Read from the connection, unless our buffers are full. */
 329                 if (buffer_len(&stdout_buffer) < buffer_high &&
 330                     buffer_len(&stderr_buffer) < buffer_high &&
 331                     channel_not_very_much_buffered_data())
 332                         FD_SET(connection_in, *readsetp);
 333                 /*
 334                  * Read from stdin, unless we have seen EOF or have very much
 335                  * buffered data to send to the server.
 336                  */
 337                 if (!stdin_eof && packet_not_very_much_data_to_write())
 338                         FD_SET(fileno(stdin), *readsetp);
 339
 340                 /* Select stdout/stderr if have data in buffer. */
 341                 if (buffer_len(&stdout_buffer) > 0)
 342                         FD_SET(fileno(stdout), *writesetp);
 343                 if (buffer_len(&stderr_buffer) > 0)
 344                         FD_SET(fileno(stderr), *writesetp);
 345         } else {
 346                 /* channel_prepare_select could have closed the last channel */
 347                 if (session_closed && !channel_still_open() &&
 348                     !packet_have_data_to_write()) {
 349                         /* clear mask since we did not call select() */
 350                         memset(*readsetp, 0, *nallocp);
 351                         memset(*writesetp, 0, *nallocp);
 352                         return;
 353                 } else {
 354                         FD_SET(connection_in, *readsetp);
 355                 }
 356         }
 357
 358         /* Select server connection if have data to write to the server. */
 359         if (packet_have_data_to_write())
 360                 FD_SET(connection_out, *writesetp);
 361
 362         /*
 363          * Wait for something to happen.  This will suspend the process until
 364          * some selected descriptor can be read, written, or has some other
 365          * event pending. Note: if you want to implement SSH_MSG_IGNORE
 366          * messages to fool traffic analysis, this might be the place to do
 367          * it: just have a random timeout for the select, and send a random
 368          * SSH_MSG_IGNORE packet when the timeout expires.
 369          */
 370
 371         if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 0) {
 372                 char buf[100];
 373
 374                 /*
 375                  * We have to clear the select masks, because we return.
 376                  * We have to return, because the mainloop checks for the flags
 377                  * set by the signal handlers.
 378                  */
 379                 memset(*readsetp, 0, *nallocp);
 380                 memset(*writesetp, 0, *nallocp);
 381
 382                 if (errno == EINTR)
 383                         return;
 384                 /* Note: we might still have data in the buffers. */
 385                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 386                 buffer_append(&stderr_buffer, buf, strlen(buf));
 387                 quit_pending = 1;
 388         }
 389 }
 390
 391 static void
 392 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 393 {
 394         struct winsize oldws, newws;
 395
 396         /* Flush stdout and stderr buffers. */
 397         if (buffer_len(bout) > 0)
 398                 atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 399         if (buffer_len(berr) > 0)
 400                 atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 401
 402         leave_raw_mode();
 403
 404         /*
 405          * Free (and clear) the buffer to reduce the amount of data that gets
 406          * written to swap.
 407          */
 408         buffer_free(bin);
 409         buffer_free(bout);
 410         buffer_free(berr);
 411
 412         /* Save old window size. */
 413         ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
 414
 415         /* Send the suspend signal to the program itself. */
 416         kill(getpid(), SIGTSTP);
 417
 418         /* Check if the window size has changed. */
 419         if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
 420             (oldws.ws_row != newws.ws_row ||
 421             oldws.ws_col != newws.ws_col ||
 422             oldws.ws_xpixel != newws.ws_xpixel ||
 423             oldws.ws_ypixel != newws.ws_ypixel))
 424                 received_window_change_signal = 1;
 425
 426         /* OK, we have been continued by the user. Reinitialize buffers. */
 427         buffer_init(bin);
 428         buffer_init(bout);
 429         buffer_init(berr);
 430
 431         enter_raw_mode();
 432 }
 433
 434 static void
 435 client_process_net_input(fd_set * readset)
 436 {
 437         int len;
 438         char buf[8192];
 439
 440         /*
 441          * Read input from the server, and add any such data to the buffer of
 442          * the packet subsystem.
 443          */
 444         if (FD_ISSET(connection_in, readset)) {
 445                 /* Read as much as possible. */
 446                 len = read(connection_in, buf, sizeof(buf));
 447                 if (len == 0) {
 448                         /* Received EOF.  The remote host has closed the connection. */
 449                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 450                                  host);
 451                         buffer_append(&stderr_buffer, buf, strlen(buf));
 452                         quit_pending = 1;
 453                         return;
 454                 }
 455                 /*
 456                  * There is a kernel bug on Solaris that causes select to
 457                  * sometimes wake up even though there is no data available.
 458                  */
 459                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 460                         len = 0;
 461
 462                 if (len < 0) {
 463                         /* An error has encountered.  Perhaps there is a network problem. */
 464                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 465                                  host, strerror(errno));
 466                         buffer_append(&stderr_buffer, buf, strlen(buf));
 467                         quit_pending = 1;
 468                         return;
 469                 }
 470                 packet_process_incoming(buf, len);
 471         }
 472 }
 473
 474 static void
 475 process_cmdline(void)
 476 {
 477         void (*handler)(int);
 478         char *s, *cmd;
 479         u_short fwd_port, fwd_host_port;
 480         char buf[1024], sfwd_port[6], sfwd_host_port[6];
 481         int local = 0;
 482
 483         leave_raw_mode();
 484         handler = signal(SIGINT, SIG_IGN);
 485         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 486         if (s == NULL)
 487                 goto out;
 488         while (*s && isspace(*s))
 489                 s++;
 490         if (*s == 0)
 491                 goto out;
 492         if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) {
 493                 log("Invalid command.");
 494                 goto out;
 495         }
 496         if (s[1] == 'L')
 497                 local = 1;
 498         if (!local && !compat20) {
 499                 log("Not supported for SSH protocol version 1.");
 500                 goto out;
 501         }
 502         s += 2;
 503         while (*s && isspace(*s))
 504                 s++;
 505
 506         if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
 507             sfwd_port, buf, sfwd_host_port) != 3 &&
 508             sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
 509             sfwd_port, buf, sfwd_host_port) != 3) {
 510                 log("Bad forwarding specification.");
 511                 goto out;
 512         }
 513         if ((fwd_port = a2port(sfwd_port)) == 0 ||
 514             (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 515                 log("Bad forwarding port(s).");
 516                 goto out;
 517         }
 518         if (local) {
 519                 if (channel_setup_local_fwd_listener(fwd_port, buf,
 520                     fwd_host_port, options.gateway_ports) < 0) {
 521                         log("Port forwarding failed.");
 522                         goto out;
 523                 }
 524         } else
 525                 channel_request_remote_forwarding(fwd_port, buf,
 526                     fwd_host_port);
 527         log("Forwarding port.");
 528 out:
 529         signal(SIGINT, handler);
 530         enter_raw_mode();
 531         if (cmd)
 532                 xfree(cmd);
 533 }
 534
 535 /* process the characters one by one */
 536 static int
 537 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
 538 {
 539         char string[1024];
 540         pid_t pid;
 541         int bytes = 0;
 542         u_int i;
 543         u_char ch;
 544         char *s;
 545
 546         for (i = 0; i < len; i++) {
 547                 /* Get one character at a time. */
 548                 ch = buf[i];
 549
 550                 if (escape_pending) {
 551                         /* We have previously seen an escape character. */
 552                         /* Clear the flag now. */
 553                         escape_pending = 0;
 554
 555                         /* Process the escaped character. */
 556                         switch (ch) {
 557                         case '.':
 558                                 /* Terminate the connection. */
 559                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
 560                                 buffer_append(berr, string, strlen(string));
 561
 562                                 quit_pending = 1;
 563                                 return -1;
 564
 565                         case 'Z' - 64:
 566                                 /* Suspend the program. */
 567                                 /* Print a message to that effect to the user. */
 568                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
 569                                 buffer_append(berr, string, strlen(string));
 570
 571                                 /* Restore terminal modes and suspend. */
 572                                 client_suspend_self(bin, bout, berr);
 573
 574                                 /* We have been continued. */
 575                                 continue;
 576
 577                         case 'R':
 578                                 if (compat20) {
 579                                         if (datafellows & SSH_BUG_NOREKEY)
 580                                                 log("Server does not support re-keying");
 581                                         else
 582                                                 need_rekeying = 1;
 583                                 }
 584                                 continue;
 585
 586                         case '&':
 587                                 /*
 588                                  * Detach the program (continue to serve connections,
 589                                  * but put in background and no more new connections).
 590                                  */
 591                                 /* Restore tty modes. */
 592                                 leave_raw_mode();
 593
 594                                 /* Stop listening for new connections. */
 595                                 channel_stop_listening();
 596
 597                                 snprintf(string, sizeof string,
 598                                     "%c& [backgrounded]\n", escape_char);
 599                                 buffer_append(berr, string, strlen(string));
 600
 601                                 /* Fork into background. */
 602                                 pid = fork();
 603                                 if (pid < 0) {
 604                                         error("fork: %.100s", strerror(errno));
 605                                         continue;
 606                                 }
 607                                 if (pid != 0) { /* This is the parent. */
 608                                         /* The parent just exits. */
 609                                         exit(0);
 610                                 }
 611                                 /* The child continues serving connections. */
 612                                 if (compat20) {
 613                                         buffer_append(bin, "\004", 1);
 614                                         /* fake EOF on stdin */
 615                                         return -1;
 616                                 } else if (!stdin_eof) {
 617                                         /*
 618                                          * Sending SSH_CMSG_EOF alone does not always appear
 619                                          * to be enough.  So we try to send an EOF character
 620                                          * first.
 621                                          */
 622                                         packet_start(SSH_CMSG_STDIN_DATA);
 623                                         packet_put_string("\004", 1);
 624                                         packet_send();
 625                                         /* Close stdin. */
 626                                         stdin_eof = 1;
 627                                         if (buffer_len(bin) == 0) {
 628                                                 packet_start(SSH_CMSG_EOF);
 629                                                 packet_send();
 630                                         }
 631                                 }
 632                                 continue;
 633
 634                         case '?':
 635                                 snprintf(string, sizeof string,
 636 "%c?\r\n\
 637 Supported escape sequences:\r\n\
 638 ~.  - terminate connection\r\n\
 639 ~C  - open a command line\r\n\
 640 ~R  - Request rekey (SSH protocol 2 only)\r\n\
 641 ~^Z - suspend ssh\r\n\
 642 ~#  - list forwarded connections\r\n\
 643 ~&  - background ssh (when waiting for connections to terminate)\r\n\
 644 ~?  - this message\r\n\
 645 ~~  - send the escape character by typing it twice\r\n\
 646 (Note that escapes are only recognized immediately after newline.)\r\n",
 647                                          escape_char);
 648                                 buffer_append(berr, string, strlen(string));
 649                                 continue;
 650
 651                         case '#':
 652                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
 653                                 buffer_append(berr, string, strlen(string));
 654                                 s = channel_open_message();
 655                                 buffer_append(berr, s, strlen(s));
 656                                 xfree(s);
 657                                 continue;
 658
 659                         case 'C':
 660                                 process_cmdline();
 661                                 continue;
 662
 663                         default:
 664                                 if (ch != escape_char) {
 665                                         buffer_put_char(bin, escape_char);
 666                                         bytes++;
 667                                 }
 668                                 /* Escaped characters fall through here */
 669                                 break;
 670                         }
 671                 } else {
 672                         /*
 673                          * The previous character was not an escape char. Check if this
 674                          * is an escape.
 675                          */
 676                         if (last_was_cr && ch == escape_char) {
 677                                 /* It is. Set the flag and continue to next character. */
 678                                 escape_pending = 1;
 679                                 continue;
 680                         }
 681                 }
 682
 683                 /*
 684                  * Normal character.  Record whether it was a newline,
 685                  * and append it to the buffer.
 686                  */
 687                 last_was_cr = (ch == '\r' || ch == '\n');
 688                 buffer_put_char(bin, ch);
 689                 bytes++;
 690         }
 691         return bytes;
 692 }
 693
 694 static void
 695 client_process_input(fd_set * readset)
 696 {
 697         int len;
 698         char buf[8192];
 699
 700         /* Read input from stdin. */
 701         if (FD_ISSET(fileno(stdin), readset)) {
 702                 /* Read as much as possible. */
 703                 len = read(fileno(stdin), buf, sizeof(buf));
 704                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 705                         return;         /* we'll try again later */
 706                 if (len <= 0) {
 707                         /*
 708                          * Received EOF or error.  They are treated
 709                          * similarly, except that an error message is printed
 710                          * if it was an error condition.
 711                          */
 712                         if (len < 0) {
 713                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
 714                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 715                         }
 716                         /* Mark that we have seen EOF. */
 717                         stdin_eof = 1;
 718                         /*
 719                          * Send an EOF message to the server unless there is
 720                          * data in the buffer.  If there is data in the
 721                          * buffer, no message will be sent now.  Code
 722                          * elsewhere will send the EOF when the buffer
 723                          * becomes empty if stdin_eof is set.
 724                          */
 725                         if (buffer_len(&stdin_buffer) == 0) {
 726                                 packet_start(SSH_CMSG_EOF);
 727                                 packet_send();
 728                         }
 729                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
 730                         /*
 731                          * Normal successful read, and no escape character.
 732                          * Just append the data to buffer.
 733                          */
 734                         buffer_append(&stdin_buffer, buf, len);
 735                 } else {
 736                         /*
 737                          * Normal, successful read.  But we have an escape character
 738                          * and have to process the characters one by one.
 739                          */
 740                         if (process_escapes(&stdin_buffer, &stdout_buffer,
 741                             &stderr_buffer, buf, len) == -1)
 742                                 return;
 743                 }
 744         }
 745 }
 746
 747 static void
 748 client_process_output(fd_set * writeset)
 749 {
 750         int len;
 751         char buf[100];
 752
 753         /* Write buffered output to stdout. */
 754         if (FD_ISSET(fileno(stdout), writeset)) {
 755                 /* Write as much data as possible. */
 756                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
 757                     buffer_len(&stdout_buffer));
 758                 if (len <= 0) {
 759                         if (errno == EINTR || errno == EAGAIN)
 760                                 len = 0;
 761                         else {
 762                                 /*
 763                                  * An error or EOF was encountered.  Put an
 764                                  * error message to stderr buffer.
 765                                  */
 766                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
 767                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 768                                 quit_pending = 1;
 769                                 return;
 770                         }
 771                 }
 772                 /* Consume printed data from the buffer. */
 773                 buffer_consume(&stdout_buffer, len);
 774                 stdout_bytes += len;
 775         }
 776         /* Write buffered output to stderr. */
 777         if (FD_ISSET(fileno(stderr), writeset)) {
 778                 /* Write as much data as possible. */
 779                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
 780                     buffer_len(&stderr_buffer));
 781                 if (len <= 0) {
 782                         if (errno == EINTR || errno == EAGAIN)
 783                                 len = 0;
 784                         else {
 785                                 /* EOF or error, but can't even print error message. */
 786                                 quit_pending = 1;
 787                                 return;
 788                         }
 789                 }
 790                 /* Consume printed characters from the buffer. */
 791                 buffer_consume(&stderr_buffer, len);
 792                 stderr_bytes += len;
 793         }
 794 }
 795
 796 /*
 797  * Get packets from the connection input buffer, and process them as long as
 798  * there are packets available.
 799  *
 800  * Any unknown packets received during the actual
 801  * session cause the session to terminate.  This is
 802  * intended to make debugging easier since no
 803  * confirmations are sent.  Any compatible protocol
 804  * extensions must be negotiated during the
 805  * preparatory phase.
 806  */
 807
 808 static void
 809 client_process_buffered_input_packets(void)
 810 {
 811         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
 812 }
 813
 814 /* scan buf[] for '~' before sending data to the peer */
 815
 816 static int
 817 simple_escape_filter(Channel *c, char *buf, int len)
 818 {
 819         /* XXX we assume c->extended is writeable */
 820         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
 821 }
 822
 823 static void
 824 client_channel_closed(int id, void *arg)
 825 {
 826         if (id != session_ident)
 827                 error("client_channel_closed: id %d != session_ident %d",
 828                     id, session_ident);
 829         channel_cancel_cleanup(id);
 830         session_closed = 1;
 831         if (in_raw_mode())
 832                 leave_raw_mode();
 833 }
 834
 835 /*
 836  * Implements the interactive session with the server.  This is called after
 837  * the user has been authenticated, and a command has been started on the
 838  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
 839  * used as an escape character for terminating or suspending the session.
 840  */
 841
 842 int
 843 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 844 {
 845         fd_set *readset = NULL, *writeset = NULL;
 846         double start_time, total_time;
 847         int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
 848         char buf[100];
 849
 850         debug("Entering interactive session.");
 851
 852         start_time = get_current_time();
 853
 854         /* Initialize variables. */
 855         escape_pending = 0;
 856         last_was_cr = 1;
 857         exit_status = -1;
 858         stdin_eof = 0;
 859         buffer_high = 64 * 1024;
 860         connection_in = packet_get_connection_in();
 861         connection_out = packet_get_connection_out();
 862         max_fd = MAX(connection_in, connection_out);
 863
 864         if (!compat20) {
 865                 /* enable nonblocking unless tty */
 866                 if (!isatty(fileno(stdin)))
 867                         set_nonblock(fileno(stdin));
 868                 if (!isatty(fileno(stdout)))
 869                         set_nonblock(fileno(stdout));
 870                 if (!isatty(fileno(stderr)))
 871                         set_nonblock(fileno(stderr));
 872                 max_fd = MAX(max_fd, fileno(stdin));
 873                 max_fd = MAX(max_fd, fileno(stdout));
 874                 max_fd = MAX(max_fd, fileno(stderr));
 875         }
 876         stdin_bytes = 0;
 877         stdout_bytes = 0;
 878         stderr_bytes = 0;
 879         quit_pending = 0;
 880         escape_char = escape_char_arg;
 881
 882         /* Initialize buffers. */
 883         buffer_init(&stdin_buffer);
 884         buffer_init(&stdout_buffer);
 885         buffer_init(&stderr_buffer);
 886
 887         client_init_dispatch();
 888
 889         /* Set signal handlers to restore non-blocking mode.  */
 890         signal(SIGINT, signal_handler);
 891         signal(SIGQUIT, signal_handler);
 892         signal(SIGTERM, signal_handler);
 893         if (have_pty)
 894                 signal(SIGWINCH, window_change_handler);
 895
 896         if (have_pty)
 897                 enter_raw_mode();
 898
 899         if (compat20) {
 900                 session_ident = ssh2_chan_id;
 901                 if (escape_char != SSH_ESCAPECHAR_NONE)
 902                         channel_register_filter(session_ident,
 903                             simple_escape_filter);
 904                 if (session_ident != -1)
 905                         channel_register_cleanup(session_ident,
 906                             client_channel_closed);
 907         } else {
 908                 /* Check if we should immediately send eof on stdin. */
 909                 client_check_initial_eof_on_stdin();
 910         }
 911
 912         /* Main loop of the client for the interactive session mode. */
 913         while (!quit_pending) {
 914
 915                 /* Process buffered packets sent by the server. */
 916                 client_process_buffered_input_packets();
 917
 918                 if (compat20 && session_closed && !channel_still_open())
 919                         break;
 920
 921                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 922
 923                 if (rekeying) {
 924                         debug("rekeying in progress");
 925                 } else {
 926                         /*
 927                          * Make packets of buffered stdin data, and buffer
 928                          * them for sending to the server.
 929                          */
 930                         if (!compat20)
 931                                 client_make_packets_from_stdin_data();
 932
 933                         /*
 934                          * Make packets from buffered channel data, and
 935                          * enqueue them for sending to the server.
 936                          */
 937                         if (packet_not_very_much_data_to_write())
 938                                 channel_output_poll();
 939
 940                         /*
 941                          * Check if the window size has changed, and buffer a
 942                          * message about it to the server if so.
 943                          */
 944                         client_check_window_change();
 945
 946                         if (quit_pending)
 947                                 break;
 948                 }
 949                 /*
 950                  * Wait until we have something to do (something becomes
 951                  * available on one of the descriptors).
 952                  */
 953                 max_fd2 = max_fd;
 954                 client_wait_until_can_do_something(&readset, &writeset,
 955                     &max_fd2, &nalloc, rekeying);
 956
 957                 if (quit_pending)
 958                         break;
 959
 960                 /* Do channel operations unless rekeying in progress. */
 961                 if (!rekeying) {
 962                         channel_after_select(readset, writeset);
 963
 964                         if (need_rekeying) {
 965                                 debug("user requests rekeying");
 966                                 xxx_kex->done = 0;
 967                                 kex_send_kexinit(xxx_kex);
 968                                 need_rekeying = 0;
 969                         }
 970                 }
 971
 972                 /* Buffer input from the connection.  */
 973                 client_process_net_input(readset);
 974
 975                 if (quit_pending)
 976                         break;
 977
 978                 if (!compat20) {
 979                         /* Buffer data from stdin */
 980                         client_process_input(readset);
 981                         /*
 982                          * Process output to stdout and stderr.  Output to
 983                          * the connection is processed elsewhere (above).
 984                          */
 985                         client_process_output(writeset);
 986                 }
 987
 988                 /* Send as much buffered packet data as possible to the sender. */
 989                 if (FD_ISSET(connection_out, writeset))
 990                         packet_write_poll();
 991         }
 992         if (readset)
 993                 xfree(readset);
 994         if (writeset)
 995                 xfree(writeset);
 996
 997         /* Terminate the session. */
 998
 999         /* Stop watching for window change. */
1000         if (have_pty)
1001                 signal(SIGWINCH, SIG_DFL);
1002
1003         channel_free_all();
1004
1005         if (have_pty)
1006                 leave_raw_mode();
1007
1008         /* restore blocking io */
1009         if (!isatty(fileno(stdin)))
1010                 unset_nonblock(fileno(stdin));
1011         if (!isatty(fileno(stdout)))
1012                 unset_nonblock(fileno(stdout));
1013         if (!isatty(fileno(stderr)))
1014                 unset_nonblock(fileno(stderr));
1015
1016         if (received_signal) {
1017                 if (in_non_blocking_mode)       /* XXX */
1018                         leave_non_blocking();
1019                 fatal("Killed by signal %d.", (int) received_signal);
1020         }
1021
1022         /*
1023          * In interactive mode (with pseudo tty) display a message indicating
1024          * that the connection has been closed.
1025          */
1026         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1027                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1028                 buffer_append(&stderr_buffer, buf, strlen(buf));
1029         }
1030
1031         /* Output any buffered data for stdout. */
1032         while (buffer_len(&stdout_buffer) > 0) {
1033                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1034                     buffer_len(&stdout_buffer));
1035                 if (len <= 0) {
1036                         error("Write failed flushing stdout buffer.");
1037                         break;
1038                 }
1039                 buffer_consume(&stdout_buffer, len);
1040                 stdout_bytes += len;
1041         }
1042
1043         /* Output any buffered data for stderr. */
1044         while (buffer_len(&stderr_buffer) > 0) {
1045                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1046                     buffer_len(&stderr_buffer));
1047                 if (len <= 0) {
1048                         error("Write failed flushing stderr buffer.");
1049                         break;
1050                 }
1051                 buffer_consume(&stderr_buffer, len);
1052                 stderr_bytes += len;
1053         }
1054
1055         /* Clear and free any buffers. */
1056         memset(buf, 0, sizeof(buf));
1057         buffer_free(&stdin_buffer);
1058         buffer_free(&stdout_buffer);
1059         buffer_free(&stderr_buffer);
1060
1061         /* Report bytes transferred, and transfer rates. */
1062         total_time = get_current_time() - start_time;
1063         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1064             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1065         if (total_time > 0)
1066                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1067                     stdin_bytes / total_time, stdout_bytes / total_time,
1068                     stderr_bytes / total_time);
1069
1070         /* Return the exit status of the program. */
1071         debug("Exit status %d", exit_status);
1072         return exit_status;
1073 }
1074
1075 /*********/
1076
1077 static void
1078 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1079 {
1080         u_int data_len;
1081         char *data = packet_get_string(&data_len);
1082         packet_check_eom();
1083         buffer_append(&stdout_buffer, data, data_len);
1084         memset(data, 0, data_len);
1085         xfree(data);
1086 }
1087 static void
1088 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1089 {
1090         u_int data_len;
1091         char *data = packet_get_string(&data_len);
1092         packet_check_eom();
1093         buffer_append(&stderr_buffer, data, data_len);
1094         memset(data, 0, data_len);
1095         xfree(data);
1096 }
1097 static void
1098 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1099 {
1100         exit_status = packet_get_int();
1101         packet_check_eom();
1102         /* Acknowledge the exit. */
1103         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1104         packet_send();
1105         /*
1106          * Must wait for packet to be sent since we are
1107          * exiting the loop.
1108          */
1109         packet_write_wait();
1110         /* Flag that we want to exit. */
1111         quit_pending = 1;
1112 }
1113
1114 static Channel *
1115 client_request_forwarded_tcpip(const char *request_type, int rchan)
1116 {
1117         Channel* c = NULL;
1118         char *listen_address, *originator_address;
1119         int listen_port, originator_port;
1120         int sock;
1121
1122         /* Get rest of the packet */
1123         listen_address = packet_get_string(NULL);
1124         listen_port = packet_get_int();
1125         originator_address = packet_get_string(NULL);
1126         originator_port = packet_get_int();
1127         packet_check_eom();
1128
1129         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1130             listen_address, listen_port, originator_address, originator_port);
1131
1132         sock = channel_connect_by_listen_address(listen_port);
1133         if (sock < 0) {
1134                 xfree(originator_address);
1135                 xfree(listen_address);
1136                 return NULL;
1137         }
1138         c = channel_new("forwarded-tcpip",
1139             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1140             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1141             xstrdup(originator_address), 1);
1142         xfree(originator_address);
1143         xfree(listen_address);
1144         return c;
1145 }
1146
1147 static Channel*
1148 client_request_x11(const char *request_type, int rchan)
1149 {
1150         Channel *c = NULL;
1151         char *originator;
1152         int originator_port;
1153         int sock;
1154
1155         if (!options.forward_x11) {
1156                 error("Warning: ssh server tried X11 forwarding.");
1157                 error("Warning: this is probably a break in attempt by a malicious server.");
1158                 return NULL;
1159         }
1160         originator = packet_get_string(NULL);
1161         if (datafellows & SSH_BUG_X11FWD) {
1162                 debug2("buggy server: x11 request w/o originator_port");
1163                 originator_port = 0;
1164         } else {
1165                 originator_port = packet_get_int();
1166         }
1167         packet_check_eom();
1168         /* XXX check permission */
1169         debug("client_request_x11: request from %s %d", originator,
1170             originator_port);
1171         xfree(originator);
1172         sock = x11_connect_display();
1173         if (sock < 0)
1174                 return NULL;
1175         c = channel_new("x11",
1176             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1177             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
1178             xstrdup("x11"), 1);
1179         c->force_drain = 1;
1180         return c;
1181 }
1182
1183 static Channel*
1184 client_request_agent(const char *request_type, int rchan)
1185 {
1186         Channel *c = NULL;
1187         int sock;
1188
1189         if (!options.forward_agent) {
1190                 error("Warning: ssh server tried agent forwarding.");
1191                 error("Warning: this is probably a break in attempt by a malicious server.");
1192                 return NULL;
1193         }
1194         sock =  ssh_get_authentication_socket();
1195         if (sock < 0)
1196                 return NULL;
1197         c = channel_new("authentication agent connection",
1198             SSH_CHANNEL_OPEN, sock, sock, -1,
1199             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1200             xstrdup("authentication agent connection"), 1);
1201         c->force_drain = 1;
1202         return c;
1203 }
1204
1205 /* XXXX move to generic input handler */
1206 static void
1207 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1208 {
1209         Channel *c = NULL;
1210         char *ctype;
1211         u_int len;
1212         int rchan;
1213         int rmaxpack;
1214         int rwindow;
1215
1216         ctype = packet_get_string(&len);
1217         rchan = packet_get_int();
1218         rwindow = packet_get_int();
1219         rmaxpack = packet_get_int();
1220
1221         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1222             ctype, rchan, rwindow, rmaxpack);
1223
1224         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1225                 c = client_request_forwarded_tcpip(ctype, rchan);
1226         } else if (strcmp(ctype, "x11") == 0) {
1227                 c = client_request_x11(ctype, rchan);
1228         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1229                 c = client_request_agent(ctype, rchan);
1230         }
1231 /* XXX duplicate : */
1232         if (c != NULL) {
1233                 debug("confirm %s", ctype);
1234                 c->remote_id = rchan;
1235                 c->remote_window = rwindow;
1236                 c->remote_maxpacket = rmaxpack;
1237                 if (c->type != SSH_CHANNEL_CONNECTING) {
1238                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1239                         packet_put_int(c->remote_id);
1240                         packet_put_int(c->self);
1241                         packet_put_int(c->local_window);
1242                         packet_put_int(c->local_maxpacket);
1243                         packet_send();
1244                 }
1245         } else {
1246                 debug("failure %s", ctype);
1247                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1248                 packet_put_int(rchan);
1249                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1250                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1251                         packet_put_cstring("open failed");
1252                         packet_put_cstring("");
1253                 }
1254                 packet_send();
1255         }
1256         xfree(ctype);
1257 }
1258 static void
1259 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1260 {
1261         Channel *c = NULL;
1262         int id, reply, success = 0;
1263         char *rtype;
1264
1265         id = packet_get_int();
1266         rtype = packet_get_string(NULL);
1267         reply = packet_get_char();
1268
1269         debug("client_input_channel_req: channel %d rtype %s reply %d",
1270             id, rtype, reply);
1271
1272         if (session_ident == -1) {
1273                 error("client_input_channel_req: no channel %d", session_ident);
1274         } else if (id != session_ident) {
1275                 error("client_input_channel_req: channel %d: wrong channel: %d",
1276                     session_ident, id);
1277         }
1278         c = channel_lookup(id);
1279         if (c == NULL) {
1280                 error("client_input_channel_req: channel %d: unknown channel", id);
1281         } else if (strcmp(rtype, "exit-status") == 0) {
1282                 success = 1;
1283                 exit_status = packet_get_int();
1284                 packet_check_eom();
1285         }
1286         if (reply) {
1287                 packet_start(success ?
1288                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1289                 packet_put_int(c->remote_id);
1290                 packet_send();
1291         }
1292         xfree(rtype);
1293 }
1294 static void
1295 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1296 {
1297         char *rtype;
1298         int want_reply;
1299         int success = 0;
1300
1301         rtype = packet_get_string(NULL);
1302         want_reply = packet_get_char();
1303         debug("client_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1304         if (want_reply) {
1305                 packet_start(success ?
1306                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1307                 packet_send();
1308                 packet_write_wait();
1309         }
1310         xfree(rtype);
1311 }
1312
1313 static void
1314 client_init_dispatch_20(void)
1315 {
1316         dispatch_init(&dispatch_protocol_error);
1317
1318         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1319         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1320         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1321         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1322         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1323         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1324         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1325         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1326         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1327         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1328
1329         /* rekeying */
1330         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1331
1332         /* global request reply messages */
1333         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1334         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1335 }
1336 static void
1337 client_init_dispatch_13(void)
1338 {
1339         dispatch_init(NULL);
1340         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1341         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1342         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1343         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1344         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1345         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1346         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1347         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1348         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1349
1350         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1351             &auth_input_open_request : &deny_input_open);
1352         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1353             &x11_input_open : &deny_input_open);
1354 }
1355 static void
1356 client_init_dispatch_15(void)
1357 {
1358         client_init_dispatch_13();
1359         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1360         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1361 }
1362 static void
1363 client_init_dispatch(void)
1364 {
1365         if (compat20)
1366                 client_init_dispatch_20();
1367         else if (compat13)
1368                 client_init_dispatch_13();
1369         else
1370                 client_init_dispatch_15();
1371 }