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 1.81 2001/07/17 21:04:57 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
  85 /* import options */
  86 extern Options options;
  87
  88 /* Flag indicating that stdin should be redirected from /dev/null. */
  89 extern int stdin_null_flag;
  90
  91 /*
  92  * Name of the host we are connecting to.  This is the name given on the
  93  * command line, or the HostName specified for the user-supplied name in a
  94  * configuration file.
  95  */
  96 extern char *host;
  97
  98 /*
  99  * Flag to indicate that we have received a window change signal which has
 100  * not yet been processed.  This will cause a message indicating the new
 101  * window size to be sent to the server a little later.  This is volatile
 102  * because this is updated in a signal handler.
 103  */
 104 static volatile int received_window_change_signal = 0;
 105 static volatile int received_signal = 0;
 106
 107 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
 108 static int in_non_blocking_mode = 0;
 109
 110 /* Common data for the client loop code. */
 111 static int quit_pending;        /* Set to non-zero to quit the client loop. */
 112 static int escape_char;         /* Escape character. */
 113 static int escape_pending;      /* Last character was the escape character */
 114 static int last_was_cr;         /* Last character was a newline. */
 115 static int exit_status;         /* Used to store the exit status of the command. */
 116 static int stdin_eof;           /* EOF has been encountered on standard error. */
 117 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 118 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 119 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 120 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 121 static u_int buffer_high;/* Soft max buffer size. */
 122 static int connection_in;       /* Connection to server (input). */
 123 static int connection_out;      /* Connection to server (output). */
 124 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 125 static int session_closed = 0;  /* In SSH2: login session closed. */
 126
 127 static void client_init_dispatch(void);
 128 int     session_ident = -1;
 129
 130 /*XXX*/
 131 extern Kex *xxx_kex;
 132
 133 /* Restores stdin to blocking mode. */
 134
 135 static void
 136 leave_non_blocking(void)
 137 {
 138         if (in_non_blocking_mode) {
 139                 (void) fcntl(fileno(stdin), F_SETFL, 0);
 140                 in_non_blocking_mode = 0;
 141                 fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
 142         }
 143 }
 144
 145 /* Puts stdin terminal in non-blocking mode. */
 146
 147 static void
 148 enter_non_blocking(void)
 149 {
 150         in_non_blocking_mode = 1;
 151         (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
 152         fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
 153 }
 154
 155 /*
 156  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 157  * flag indicating that the window has changed.
 158  */
 159
 160 static void
 161 window_change_handler(int sig)
 162 {
 163         received_window_change_signal = 1;
 164         signal(SIGWINCH, window_change_handler);
 165 }
 166
 167 /*
 168  * Signal handler for signals that cause the program to terminate.  These
 169  * signals must be trapped to restore terminal modes.
 170  */
 171
 172 static void
 173 signal_handler(int sig)
 174 {
 175         received_signal = sig;
 176         quit_pending = 1;
 177 }
 178
 179 /*
 180  * Returns current time in seconds from Jan 1, 1970 with the maximum
 181  * available resolution.
 182  */
 183
 184 static double
 185 get_current_time(void)
 186 {
 187         struct timeval tv;
 188         gettimeofday(&tv, NULL);
 189         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 190 }
 191
 192 /*
 193  * This is called when the interactive is entered.  This checks if there is
 194  * an EOF coming on stdin.  We must check this explicitly, as select() does
 195  * not appear to wake up when redirecting from /dev/null.
 196  */
 197
 198 static void
 199 client_check_initial_eof_on_stdin(void)
 200 {
 201         int len;
 202         char buf[1];
 203
 204         /*
 205          * If standard input is to be "redirected from /dev/null", we simply
 206          * mark that we have seen an EOF and send an EOF message to the
 207          * server. Otherwise, we try to read a single character; it appears
 208          * that for some files, such /dev/null, select() never wakes up for
 209          * read for this descriptor, which means that we never get EOF.  This
 210          * way we will get the EOF if stdin comes from /dev/null or similar.
 211          */
 212         if (stdin_null_flag) {
 213                 /* Fake EOF on stdin. */
 214                 debug("Sending eof.");
 215                 stdin_eof = 1;
 216                 packet_start(SSH_CMSG_EOF);
 217                 packet_send();
 218         } else {
 219                 enter_non_blocking();
 220
 221                 /* Check for immediate EOF on stdin. */
 222                 len = read(fileno(stdin), buf, 1);
 223                 if (len == 0) {
 224                         /* EOF.  Record that we have seen it and send EOF to server. */
 225                         debug("Sending eof.");
 226                         stdin_eof = 1;
 227                         packet_start(SSH_CMSG_EOF);
 228                         packet_send();
 229                 } else if (len > 0) {
 230                         /*
 231                          * Got data.  We must store the data in the buffer,
 232                          * and also process it as an escape character if
 233                          * appropriate.
 234                          */
 235                         if ((u_char) buf[0] == escape_char)
 236                                 escape_pending = 1;
 237                         else
 238                                 buffer_append(&stdin_buffer, buf, 1);
 239                 }
 240                 leave_non_blocking();
 241         }
 242 }
 243
 244
 245 /*
 246  * Make packets from buffered stdin data, and buffer them for sending to the
 247  * connection.
 248  */
 249
 250 static void
 251 client_make_packets_from_stdin_data(void)
 252 {
 253         u_int len;
 254
 255         /* Send buffered stdin data to the server. */
 256         while (buffer_len(&stdin_buffer) > 0 &&
 257                packet_not_very_much_data_to_write()) {
 258                 len = buffer_len(&stdin_buffer);
 259                 /* Keep the packets at reasonable size. */
 260                 if (len > packet_get_maxsize())
 261                         len = packet_get_maxsize();
 262                 packet_start(SSH_CMSG_STDIN_DATA);
 263                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 264                 packet_send();
 265                 buffer_consume(&stdin_buffer, len);
 266                 stdin_bytes += len;
 267                 /* If we have a pending EOF, send it now. */
 268                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 269                         packet_start(SSH_CMSG_EOF);
 270                         packet_send();
 271                 }
 272         }
 273 }
 274
 275 /*
 276  * Checks if the client window has changed, and sends a packet about it to
 277  * the server if so.  The actual change is detected elsewhere (by a software
 278  * interrupt on Unix); this just checks the flag and sends a message if
 279  * appropriate.
 280  */
 281
 282 static void
 283 client_check_window_change(void)
 284 {
 285         struct winsize ws;
 286
 287         if (! received_window_change_signal)
 288                 return;
 289         /** XXX race */
 290         received_window_change_signal = 0;
 291
 292         if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 293                 return;
 294
 295         debug2("client_check_window_change: changed");
 296
 297         if (compat20) {
 298                 channel_request_start(session_ident, "window-change", 0);
 299                 packet_put_int(ws.ws_col);
 300                 packet_put_int(ws.ws_row);
 301                 packet_put_int(ws.ws_xpixel);
 302                 packet_put_int(ws.ws_ypixel);
 303                 packet_send();
 304         } else {
 305                 packet_start(SSH_CMSG_WINDOW_SIZE);
 306                 packet_put_int(ws.ws_row);
 307                 packet_put_int(ws.ws_col);
 308                 packet_put_int(ws.ws_xpixel);
 309                 packet_put_int(ws.ws_ypixel);
 310                 packet_send();
 311         }
 312 }
 313
 314 /*
 315  * Waits until the client can do something (some data becomes available on
 316  * one of the file descriptors).
 317  */
 318
 319 static void
 320 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 321     int *maxfdp, int *nallocp, int rekeying)
 322 {
 323         /* Add any selections by the channel mechanism. */
 324         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 325
 326         if (!compat20) {
 327                 /* Read from the connection, unless our buffers are full. */
 328                 if (buffer_len(&stdout_buffer) < buffer_high &&
 329                     buffer_len(&stderr_buffer) < buffer_high &&
 330                     channel_not_very_much_buffered_data())
 331                         FD_SET(connection_in, *readsetp);
 332                 /*
 333                  * Read from stdin, unless we have seen EOF or have very much
 334                  * buffered data to send to the server.
 335                  */
 336                 if (!stdin_eof && packet_not_very_much_data_to_write())
 337                         FD_SET(fileno(stdin), *readsetp);
 338
 339                 /* Select stdout/stderr if have data in buffer. */
 340                 if (buffer_len(&stdout_buffer) > 0)
 341                         FD_SET(fileno(stdout), *writesetp);
 342                 if (buffer_len(&stderr_buffer) > 0)
 343                         FD_SET(fileno(stderr), *writesetp);
 344         } else {
 345                 /* channel_prepare_select could have closed the last channel */
 346                 if (session_closed && !channel_still_open()) {
 347                         if (!packet_have_data_to_write())
 348                                 return;
 349                 } else {
 350                         FD_SET(connection_in, *readsetp);
 351                 }
 352         }
 353
 354         /* Select server connection if have data to write to the server. */
 355         if (packet_have_data_to_write())
 356                 FD_SET(connection_out, *writesetp);
 357
 358         /*
 359          * Wait for something to happen.  This will suspend the process until
 360          * some selected descriptor can be read, written, or has some other
 361          * event pending. Note: if you want to implement SSH_MSG_IGNORE
 362          * messages to fool traffic analysis, this might be the place to do
 363          * it: just have a random timeout for the select, and send a random
 364          * SSH_MSG_IGNORE packet when the timeout expires.
 365          */
 366
 367         if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 0) {
 368                 char buf[100];
 369
 370                 /*
 371                  * We have to clear the select masks, because we return.
 372                  * We have to return, because the mainloop checks for the flags
 373                  * set by the signal handlers.
 374                  */
 375                 memset(*readsetp, 0, *maxfdp);
 376                 memset(*writesetp, 0, *maxfdp);
 377
 378                 if (errno == EINTR)
 379                         return;
 380                 /* Note: we might still have data in the buffers. */
 381                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 382                 buffer_append(&stderr_buffer, buf, strlen(buf));
 383                 quit_pending = 1;
 384         }
 385 }
 386
 387 static void
 388 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 389 {
 390         struct winsize oldws, newws;
 391
 392         /* Flush stdout and stderr buffers. */
 393         if (buffer_len(bout) > 0)
 394                 atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 395         if (buffer_len(berr) > 0)
 396                 atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 397
 398         leave_raw_mode();
 399
 400         /*
 401          * Free (and clear) the buffer to reduce the amount of data that gets
 402          * written to swap.
 403          */
 404         buffer_free(bin);
 405         buffer_free(bout);
 406         buffer_free(berr);
 407
 408         /* Save old window size. */
 409         ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
 410
 411         /* Send the suspend signal to the program itself. */
 412         kill(getpid(), SIGTSTP);
 413
 414         /* Check if the window size has changed. */
 415         if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
 416             (oldws.ws_row != newws.ws_row ||
 417              oldws.ws_col != newws.ws_col ||
 418              oldws.ws_xpixel != newws.ws_xpixel ||
 419              oldws.ws_ypixel != newws.ws_ypixel))
 420                 received_window_change_signal = 1;
 421
 422         /* OK, we have been continued by the user. Reinitialize buffers. */
 423         buffer_init(bin);
 424         buffer_init(bout);
 425         buffer_init(berr);
 426
 427         enter_raw_mode();
 428 }
 429
 430 static void
 431 client_process_net_input(fd_set * readset)
 432 {
 433         int len;
 434         char buf[8192];
 435
 436         /*
 437          * Read input from the server, and add any such data to the buffer of
 438          * the packet subsystem.
 439          */
 440         if (FD_ISSET(connection_in, readset)) {
 441                 /* Read as much as possible. */
 442                 len = read(connection_in, buf, sizeof(buf));
 443                 if (len == 0) {
 444                         /* Received EOF.  The remote host has closed the connection. */
 445                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 446                                  host);
 447                         buffer_append(&stderr_buffer, buf, strlen(buf));
 448                         quit_pending = 1;
 449                         return;
 450                 }
 451                 /*
 452                  * There is a kernel bug on Solaris that causes select to
 453                  * sometimes wake up even though there is no data available.
 454                  */
 455                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 456                         len = 0;
 457
 458                 if (len < 0) {
 459                         /* An error has encountered.  Perhaps there is a network problem. */
 460                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 461                                  host, strerror(errno));
 462                         buffer_append(&stderr_buffer, buf, strlen(buf));
 463                         quit_pending = 1;
 464                         return;
 465                 }
 466                 packet_process_incoming(buf, len);
 467         }
 468 }
 469
 470 /* process the characters one by one */
 471 static int
 472 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
 473 {
 474         char string[1024];
 475         pid_t pid;
 476         int bytes = 0;
 477         u_int i;
 478         u_char ch;
 479         char *s;
 480
 481         for (i = 0; i < len; i++) {
 482                 /* Get one character at a time. */
 483                 ch = buf[i];
 484
 485                 if (escape_pending) {
 486                         /* We have previously seen an escape character. */
 487                         /* Clear the flag now. */
 488                         escape_pending = 0;
 489
 490                         /* Process the escaped character. */
 491                         switch (ch) {
 492                         case '.':
 493                                 /* Terminate the connection. */
 494                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
 495                                 buffer_append(berr, string, strlen(string));
 496
 497                                 quit_pending = 1;
 498                                 return -1;
 499
 500                         case 'Z' - 64:
 501                                 /* Suspend the program. */
 502                                 /* Print a message to that effect to the user. */
 503                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
 504                                 buffer_append(berr, string, strlen(string));
 505
 506                                 /* Restore terminal modes and suspend. */
 507                                 client_suspend_self(bin, bout, berr);
 508
 509                                 /* We have been continued. */
 510                                 continue;
 511
 512                         case 'R':
 513                                 if (compat20) {
 514                                         if (datafellows & SSH_BUG_NOREKEY)
 515                                                 log("Server does not support re-keying");
 516                                         else
 517                                                 need_rekeying = 1;
 518                                 }
 519                                 continue;
 520
 521                         case '&':
 522                                 /* XXX does not work yet with proto 2 */
 523                                 if (compat20)
 524                                         continue;
 525                                 /*
 526                                  * Detach the program (continue to serve connections,
 527                                  * but put in background and no more new connections).
 528                                  */
 529                                 if (!stdin_eof) {
 530                                         /*
 531                                          * Sending SSH_CMSG_EOF alone does not always appear
 532                                          * to be enough.  So we try to send an EOF character
 533                                          * first.
 534                                          */
 535                                         packet_start(SSH_CMSG_STDIN_DATA);
 536                                         packet_put_string("\004", 1);
 537                                         packet_send();
 538                                         /* Close stdin. */
 539                                         stdin_eof = 1;
 540                                         if (buffer_len(bin) == 0) {
 541                                                 packet_start(SSH_CMSG_EOF);
 542                                                 packet_send();
 543                                         }
 544                                 }
 545                                 /* Restore tty modes. */
 546                                 leave_raw_mode();
 547
 548                                 /* Stop listening for new connections. */
 549                                 channel_close_all();    /* proto1 only XXXX */
 550
 551                                 printf("%c& [backgrounded]\n", escape_char);
 552
 553                                 /* Fork into background. */
 554                                 pid = fork();
 555                                 if (pid < 0) {
 556                                         error("fork: %.100s", strerror(errno));
 557                                         continue;
 558                                 }
 559                                 if (pid != 0) { /* This is the parent. */
 560                                         /* The parent just exits. */
 561                                         exit(0);
 562                                 }
 563                                 /* The child continues serving connections. */
 564                                 continue; /*XXX ? */
 565
 566                         case '?':
 567                                 snprintf(string, sizeof string,
 568 "%c?\r\n\
 569 Supported escape sequences:\r\n\
 570 ~.  - terminate connection\r\n\
 571 ~R  - Request rekey (SSH protocol 2 only)\r\n\
 572 ~^Z - suspend ssh\r\n\
 573 ~#  - list forwarded connections\r\n\
 574 ~&  - background ssh (when waiting for connections to terminate)\r\n\
 575 ~?  - this message\r\n\
 576 ~~  - send the escape character by typing it twice\r\n\
 577 (Note that escapes are only recognized immediately after newline.)\r\n",
 578                                          escape_char);
 579                                 buffer_append(berr, string, strlen(string));
 580                                 continue;
 581
 582                         case '#':
 583                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
 584                                 buffer_append(berr, string, strlen(string));
 585                                 s = channel_open_message();
 586                                 buffer_append(berr, s, strlen(s));
 587                                 xfree(s);
 588                                 continue;
 589
 590                         default:
 591                                 if (ch != escape_char) {
 592                                         buffer_put_char(bin, escape_char);
 593                                         bytes++;
 594                                 }
 595                                 /* Escaped characters fall through here */
 596                                 break;
 597                         }
 598                 } else {
 599                         /*
 600                          * The previous character was not an escape char. Check if this
 601                          * is an escape.
 602                          */
 603                         if (last_was_cr && ch == escape_char) {
 604                                 /* It is. Set the flag and continue to next character. */
 605                                 escape_pending = 1;
 606                                 continue;
 607                         }
 608                 }
 609
 610                 /*
 611                  * Normal character.  Record whether it was a newline,
 612                  * and append it to the buffer.
 613                  */
 614                 last_was_cr = (ch == '\r' || ch == '\n');
 615                 buffer_put_char(bin, ch);
 616                 bytes++;
 617         }
 618         return bytes;
 619 }
 620
 621 static void
 622 client_process_input(fd_set * readset)
 623 {
 624         int len;
 625         char buf[8192];
 626
 627         /* Read input from stdin. */
 628         if (FD_ISSET(fileno(stdin), readset)) {
 629                 /* Read as much as possible. */
 630                 len = read(fileno(stdin), buf, sizeof(buf));
 631                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 632                         return;         /* we'll try again later */
 633                 if (len <= 0) {
 634                         /*
 635                          * Received EOF or error.  They are treated
 636                          * similarly, except that an error message is printed
 637                          * if it was an error condition.
 638                          */
 639                         if (len < 0) {
 640                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
 641                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 642                         }
 643                         /* Mark that we have seen EOF. */
 644                         stdin_eof = 1;
 645                         /*
 646                          * Send an EOF message to the server unless there is
 647                          * data in the buffer.  If there is data in the
 648                          * buffer, no message will be sent now.  Code
 649                          * elsewhere will send the EOF when the buffer
 650                          * becomes empty if stdin_eof is set.
 651                          */
 652                         if (buffer_len(&stdin_buffer) == 0) {
 653                                 packet_start(SSH_CMSG_EOF);
 654                                 packet_send();
 655                         }
 656                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
 657                         /*
 658                          * Normal successful read, and no escape character.
 659                          * Just append the data to buffer.
 660                          */
 661                         buffer_append(&stdin_buffer, buf, len);
 662                 } else {
 663                         /*
 664                          * Normal, successful read.  But we have an escape character
 665                          * and have to process the characters one by one.
 666                          */
 667                         if (process_escapes(&stdin_buffer, &stdout_buffer,
 668                             &stderr_buffer, buf, len) == -1)
 669                                 return;
 670                 }
 671         }
 672 }
 673
 674 static void
 675 client_process_output(fd_set * writeset)
 676 {
 677         int len;
 678         char buf[100];
 679
 680         /* Write buffered output to stdout. */
 681         if (FD_ISSET(fileno(stdout), writeset)) {
 682                 /* Write as much data as possible. */
 683                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
 684                     buffer_len(&stdout_buffer));
 685                 if (len <= 0) {
 686                         if (errno == EINTR || errno == EAGAIN)
 687                                 len = 0;
 688                         else {
 689                                 /*
 690                                  * An error or EOF was encountered.  Put an
 691                                  * error message to stderr buffer.
 692                                  */
 693                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
 694                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 695                                 quit_pending = 1;
 696                                 return;
 697                         }
 698                 }
 699                 /* Consume printed data from the buffer. */
 700                 buffer_consume(&stdout_buffer, len);
 701                 stdout_bytes += len;
 702         }
 703         /* Write buffered output to stderr. */
 704         if (FD_ISSET(fileno(stderr), writeset)) {
 705                 /* Write as much data as possible. */
 706                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
 707                     buffer_len(&stderr_buffer));
 708                 if (len <= 0) {
 709                         if (errno == EINTR || errno == EAGAIN)
 710                                 len = 0;
 711                         else {
 712                                 /* EOF or error, but can't even print error message. */
 713                                 quit_pending = 1;
 714                                 return;
 715                         }
 716                 }
 717                 /* Consume printed characters from the buffer. */
 718                 buffer_consume(&stderr_buffer, len);
 719                 stderr_bytes += len;
 720         }
 721 }
 722
 723 /*
 724  * Get packets from the connection input buffer, and process them as long as
 725  * there are packets available.
 726  *
 727  * Any unknown packets received during the actual
 728  * session cause the session to terminate.  This is
 729  * intended to make debugging easier since no
 730  * confirmations are sent.  Any compatible protocol
 731  * extensions must be negotiated during the
 732  * preparatory phase.
 733  */
 734
 735 static void
 736 client_process_buffered_input_packets(void)
 737 {
 738         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
 739 }
 740
 741 /* scan buf[] for '~' before sending data to the peer */
 742
 743 static int
 744 simple_escape_filter(Channel *c, char *buf, int len)
 745 {
 746         /* XXX we assume c->extended is writeable */
 747         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
 748 }
 749
 750 static void
 751 client_channel_closed(int id, void *arg)
 752 {
 753         if (id != session_ident)
 754                 error("client_channel_closed: id %d != session_ident %d",
 755                     id, session_ident);
 756         session_closed = 1;
 757         if (in_raw_mode())
 758                 leave_raw_mode();
 759 }
 760
 761 /*
 762  * Implements the interactive session with the server.  This is called after
 763  * the user has been authenticated, and a command has been started on the
 764  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
 765  * used as an escape character for terminating or suspending the session.
 766  */
 767
 768 int
 769 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 770 {
 771         fd_set *readset = NULL, *writeset = NULL;
 772         double start_time, total_time;
 773         int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
 774         char buf[100];
 775
 776         debug("Entering interactive session.");
 777
 778         start_time = get_current_time();
 779
 780         /* Initialize variables. */
 781         escape_pending = 0;
 782         last_was_cr = 1;
 783         exit_status = -1;
 784         stdin_eof = 0;
 785         buffer_high = 64 * 1024;
 786         connection_in = packet_get_connection_in();
 787         connection_out = packet_get_connection_out();
 788         max_fd = MAX(connection_in, connection_out);
 789
 790         if (!compat20) {
 791                 /* enable nonblocking unless tty */
 792                 if (!isatty(fileno(stdin)))
 793                         set_nonblock(fileno(stdin));
 794                 if (!isatty(fileno(stdout)))
 795                         set_nonblock(fileno(stdout));
 796                 if (!isatty(fileno(stderr)))
 797                         set_nonblock(fileno(stderr));
 798                 max_fd = MAX(max_fd, fileno(stdin));
 799                 max_fd = MAX(max_fd, fileno(stdout));
 800                 max_fd = MAX(max_fd, fileno(stderr));
 801         }
 802         stdin_bytes = 0;
 803         stdout_bytes = 0;
 804         stderr_bytes = 0;
 805         quit_pending = 0;
 806         escape_char = escape_char_arg;
 807
 808         /* Initialize buffers. */
 809         buffer_init(&stdin_buffer);
 810         buffer_init(&stdout_buffer);
 811         buffer_init(&stderr_buffer);
 812
 813         client_init_dispatch();
 814
 815         /* Set signal handlers to restore non-blocking mode.  */
 816         signal(SIGINT, signal_handler);
 817         signal(SIGQUIT, signal_handler);
 818         signal(SIGTERM, signal_handler);
 819         signal(SIGPIPE, SIG_IGN);
 820         if (have_pty)
 821                 signal(SIGWINCH, window_change_handler);
 822
 823         if (have_pty)
 824                 enter_raw_mode();
 825
 826         if (compat20) {
 827                 session_ident = ssh2_chan_id;
 828                 if (escape_char != SSH_ESCAPECHAR_NONE)
 829                         channel_register_filter(session_ident,
 830                             simple_escape_filter);
 831                 if (session_ident != -1)
 832                         channel_register_cleanup(session_ident,
 833                             client_channel_closed);
 834         } else {
 835                 /* Check if we should immediately send eof on stdin. */
 836                 client_check_initial_eof_on_stdin();
 837         }
 838
 839         /* Main loop of the client for the interactive session mode. */
 840         while (!quit_pending) {
 841
 842                 /* Process buffered packets sent by the server. */
 843                 client_process_buffered_input_packets();
 844
 845                 if (compat20 && session_closed && !channel_still_open())
 846                         break;
 847
 848                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 849
 850                 if (rekeying) {
 851                         debug("rekeying in progress");
 852                 } else {
 853                         /*
 854                          * Make packets of buffered stdin data, and buffer
 855                          * them for sending to the server.
 856                          */
 857                         if (!compat20)
 858                                 client_make_packets_from_stdin_data();
 859
 860                         /*
 861                          * Make packets from buffered channel data, and
 862                          * enqueue them for sending to the server.
 863                          */
 864                         if (packet_not_very_much_data_to_write())
 865                                 channel_output_poll();
 866
 867                         /*
 868                          * Check if the window size has changed, and buffer a
 869                          * message about it to the server if so.
 870                          */
 871                         client_check_window_change();
 872
 873                         if (quit_pending)
 874                                 break;
 875                 }
 876                 /*
 877                  * Wait until we have something to do (something becomes
 878                  * available on one of the descriptors).
 879                  */
 880                 max_fd2 = max_fd;
 881                 client_wait_until_can_do_something(&readset, &writeset,
 882                     &max_fd2, &nalloc, rekeying);
 883
 884                 if (quit_pending)
 885                         break;
 886
 887                 /* Do channel operations unless rekeying in progress. */
 888                 if (!rekeying) {
 889                         channel_after_select(readset, writeset);
 890
 891                         if (need_rekeying) {
 892                                 debug("user requests rekeying");
 893                                 xxx_kex->done = 0;
 894                                 kex_send_kexinit(xxx_kex);
 895                                 need_rekeying = 0;
 896                         }
 897                 }
 898
 899                 /* Buffer input from the connection.  */
 900                 client_process_net_input(readset);
 901
 902                 if (quit_pending)
 903                         break;
 904
 905                 if (!compat20) {
 906                         /* Buffer data from stdin */
 907                         client_process_input(readset);
 908                         /*
 909                          * Process output to stdout and stderr.  Output to
 910                          * the connection is processed elsewhere (above).
 911                          */
 912                         client_process_output(writeset);
 913                 }
 914
 915                 /* Send as much buffered packet data as possible to the sender. */
 916                 if (FD_ISSET(connection_out, writeset))
 917                         packet_write_poll();
 918         }
 919         if (readset)
 920                 xfree(readset);
 921         if (writeset)
 922                 xfree(writeset);
 923
 924         /* Terminate the session. */
 925
 926         /* Stop watching for window change. */
 927         if (have_pty)
 928                 signal(SIGWINCH, SIG_DFL);
 929
 930         channel_free_all();
 931
 932         if (have_pty)
 933                 leave_raw_mode();
 934
 935         /* restore blocking io */
 936         if (!isatty(fileno(stdin)))
 937                 unset_nonblock(fileno(stdin));
 938         if (!isatty(fileno(stdout)))
 939                 unset_nonblock(fileno(stdout));
 940         if (!isatty(fileno(stderr)))
 941                 unset_nonblock(fileno(stderr));
 942
 943         if (received_signal) {
 944                 if (in_non_blocking_mode)       /* XXX */
 945                         leave_non_blocking();
 946                 fatal("Killed by signal %d.", received_signal);
 947         }
 948
 949         /*
 950          * In interactive mode (with pseudo tty) display a message indicating
 951          * that the connection has been closed.
 952          */
 953         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
 954                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
 955                 buffer_append(&stderr_buffer, buf, strlen(buf));
 956         }
 957
 958         /* Output any buffered data for stdout. */
 959         while (buffer_len(&stdout_buffer) > 0) {
 960                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
 961                     buffer_len(&stdout_buffer));
 962                 if (len <= 0) {
 963                         error("Write failed flushing stdout buffer.");
 964                         break;
 965                 }
 966                 buffer_consume(&stdout_buffer, len);
 967                 stdout_bytes += len;
 968         }
 969
 970         /* Output any buffered data for stderr. */
 971         while (buffer_len(&stderr_buffer) > 0) {
 972                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
 973                     buffer_len(&stderr_buffer));
 974                 if (len <= 0) {
 975                         error("Write failed flushing stderr buffer.");
 976                         break;
 977                 }
 978                 buffer_consume(&stderr_buffer, len);
 979                 stderr_bytes += len;
 980         }
 981
 982         /* Clear and free any buffers. */
 983         memset(buf, 0, sizeof(buf));
 984         buffer_free(&stdin_buffer);
 985         buffer_free(&stdout_buffer);
 986         buffer_free(&stderr_buffer);
 987
 988         /* Report bytes transferred, and transfer rates. */
 989         total_time = get_current_time() - start_time;
 990         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
 991               stdin_bytes, stdout_bytes, stderr_bytes, total_time);
 992         if (total_time > 0)
 993                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
 994                       stdin_bytes / total_time, stdout_bytes / total_time,
 995                       stderr_bytes / total_time);
 996
 997         /* Return the exit status of the program. */
 998         debug("Exit status %d", exit_status);
 999         return exit_status;
1000 }
1001
1002 /*********/
1003
1004 static void
1005 client_input_stdout_data(int type, int plen, void *ctxt)
1006 {
1007         u_int data_len;
1008         char *data = packet_get_string(&data_len);
1009         packet_integrity_check(plen, 4 + data_len, type);
1010         buffer_append(&stdout_buffer, data, data_len);
1011         memset(data, 0, data_len);
1012         xfree(data);
1013 }
1014 static void
1015 client_input_stderr_data(int type, int plen, void *ctxt)
1016 {
1017         u_int data_len;
1018         char *data = packet_get_string(&data_len);
1019         packet_integrity_check(plen, 4 + data_len, type);
1020         buffer_append(&stderr_buffer, data, data_len);
1021         memset(data, 0, data_len);
1022         xfree(data);
1023 }
1024 static void
1025 client_input_exit_status(int type, int plen, void *ctxt)
1026 {
1027         packet_integrity_check(plen, 4, type);
1028         exit_status = packet_get_int();
1029         /* Acknowledge the exit. */
1030         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1031         packet_send();
1032         /*
1033          * Must wait for packet to be sent since we are
1034          * exiting the loop.
1035          */
1036         packet_write_wait();
1037         /* Flag that we want to exit. */
1038         quit_pending = 1;
1039 }
1040
1041 static Channel *
1042 client_request_forwarded_tcpip(const char *request_type, int rchan)
1043 {
1044         Channel* c = NULL;
1045         char *listen_address, *originator_address;
1046         int listen_port, originator_port;
1047         int sock;
1048
1049         /* Get rest of the packet */
1050         listen_address = packet_get_string(NULL);
1051         listen_port = packet_get_int();
1052         originator_address = packet_get_string(NULL);
1053         originator_port = packet_get_int();
1054         packet_done();
1055
1056         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1057             listen_address, listen_port, originator_address, originator_port);
1058
1059         sock = channel_connect_by_listen_address(listen_port);
1060         if (sock < 0) {
1061                 xfree(originator_address);
1062                 xfree(listen_address);
1063                 return NULL;
1064         }
1065         c = channel_new("forwarded-tcpip",
1066             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1067             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1068             xstrdup(originator_address), 1);
1069         if (c == NULL) {
1070                 error("client_request_forwarded_tcpip: channel_new failed");
1071                 close(sock);
1072         }
1073         xfree(originator_address);
1074         xfree(listen_address);
1075         return c;
1076 }
1077
1078 static Channel*
1079 client_request_x11(const char *request_type, int rchan)
1080 {
1081         Channel *c = NULL;
1082         char *originator;
1083         int originator_port;
1084         int sock;
1085
1086         if (!options.forward_x11) {
1087                 error("Warning: ssh server tried X11 forwarding.");
1088                 error("Warning: this is probably a break in attempt by a malicious server.");
1089                 return NULL;
1090         }
1091         originator = packet_get_string(NULL);
1092         if (datafellows & SSH_BUG_X11FWD) {
1093                 debug2("buggy server: x11 request w/o originator_port");
1094                 originator_port = 0;
1095         } else {
1096                 originator_port = packet_get_int();
1097         }
1098         packet_done();
1099         /* XXX check permission */
1100         debug("client_request_x11: request from %s %d", originator,
1101             originator_port);
1102         xfree(originator);
1103         sock = x11_connect_display();
1104         if (sock < 0)
1105                 return NULL;
1106         c = channel_new("x11",
1107             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1108             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
1109             xstrdup("x11"), 1);
1110         if (c == NULL) {
1111                 error("client_request_x11: channel_new failed");
1112                 close(sock);
1113         }
1114         return c;
1115 }
1116
1117 static Channel*
1118 client_request_agent(const char *request_type, int rchan)
1119 {
1120         Channel *c = NULL;
1121         int sock;
1122
1123         if (!options.forward_agent) {
1124                 error("Warning: ssh server tried agent forwarding.");
1125                 error("Warning: this is probably a break in attempt by a malicious server.");
1126                 return NULL;
1127         }
1128         sock =  ssh_get_authentication_socket();
1129         if (sock < 0)
1130                 return NULL;
1131         c = channel_new("authentication agent connection",
1132             SSH_CHANNEL_OPEN, sock, sock, -1,
1133             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1134             xstrdup("authentication agent connection"), 1);
1135         if (c == NULL) {
1136                 error("client_request_agent: channel_new failed");
1137                 close(sock);
1138         }
1139         return c;
1140 }
1141
1142 /* XXXX move to generic input handler */
1143 static void
1144 client_input_channel_open(int type, int plen, void *ctxt)
1145 {
1146         Channel *c = NULL;
1147         char *ctype;
1148         u_int len;
1149         int rchan;
1150         int rmaxpack;
1151         int rwindow;
1152
1153         ctype = packet_get_string(&len);
1154         rchan = packet_get_int();
1155         rwindow = packet_get_int();
1156         rmaxpack = packet_get_int();
1157
1158         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1159             ctype, rchan, rwindow, rmaxpack);
1160
1161         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1162                 c = client_request_forwarded_tcpip(ctype, rchan);
1163         } else if (strcmp(ctype, "x11") == 0) {
1164                 c = client_request_x11(ctype, rchan);
1165         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1166                 c = client_request_agent(ctype, rchan);
1167         }
1168 /* XXX duplicate : */
1169         if (c != NULL) {
1170                 debug("confirm %s", ctype);
1171                 c->remote_id = rchan;
1172                 c->remote_window = rwindow;
1173                 c->remote_maxpacket = rmaxpack;
1174                 if (c->type != SSH_CHANNEL_CONNECTING) {
1175                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1176                         packet_put_int(c->remote_id);
1177                         packet_put_int(c->self);
1178                         packet_put_int(c->local_window);
1179                         packet_put_int(c->local_maxpacket);
1180                         packet_send();
1181                 }
1182         } else {
1183                 debug("failure %s", ctype);
1184                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1185                 packet_put_int(rchan);
1186                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1187                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1188                         packet_put_cstring("open failed");
1189                         packet_put_cstring("");
1190                 }
1191                 packet_send();
1192         }
1193         xfree(ctype);
1194 }
1195 static void
1196 client_input_channel_req(int type, int plen, void *ctxt)
1197 {
1198         Channel *c = NULL;
1199         int id, reply, success = 0;
1200         char *rtype;
1201
1202         id = packet_get_int();
1203         rtype = packet_get_string(NULL);
1204         reply = packet_get_char();
1205
1206         debug("client_input_channel_req: channel %d rtype %s reply %d",
1207             id, rtype, reply);
1208
1209         if (session_ident == -1) {
1210                 error("client_input_channel_req: no channel %d", session_ident);
1211         } else if (id != session_ident) {
1212                 error("client_input_channel_req: channel %d: wrong channel: %d",
1213                     session_ident, id);
1214         }
1215         c = channel_lookup(id);
1216         if (c == NULL) {
1217                 error("client_input_channel_req: channel %d: unknown channel", id);
1218         } else if (strcmp(rtype, "exit-status") == 0) {
1219                 success = 1;
1220                 exit_status = packet_get_int();
1221                 packet_done();
1222         }
1223         if (reply) {
1224                 packet_start(success ?
1225                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1226                 packet_put_int(c->remote_id);
1227                 packet_send();
1228         }
1229         xfree(rtype);
1230 }
1231
1232 static void
1233 client_init_dispatch_20(void)
1234 {
1235         dispatch_init(&dispatch_protocol_error);
1236         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1237         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1238         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1239         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1240         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1241         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1242         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1243         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1244         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1245
1246         /* rekeying */
1247         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1248 }
1249 static void
1250 client_init_dispatch_13(void)
1251 {
1252         dispatch_init(NULL);
1253         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1254         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1255         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1256         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1257         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1258         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1259         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1260         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1261         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1262
1263         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1264             &auth_input_open_request : &deny_input_open);
1265         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1266             &x11_input_open : &deny_input_open);
1267 }
1268 static void
1269 client_init_dispatch_15(void)
1270 {
1271         client_init_dispatch_13();
1272         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1273         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1274 }
1275 static void
1276 client_init_dispatch(void)
1277 {
1278         if (compat20)
1279                 client_init_dispatch_20();
1280         else if (compat13)
1281                 client_init_dispatch_13();
1282         else
1283                 client_init_dispatch_15();
1284 }