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 1.120 2004/05/20 10:58:05 dtucker 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 "sshpty.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 /* Flag indicating that no shell has been requested */
  92 extern int no_shell_flag;
  93
  94 /*
  95  * Name of the host we are connecting to.  This is the name given on the
  96  * command line, or the HostName specified for the user-supplied name in a
  97  * configuration file.
  98  */
  99 extern char *host;
 100
 101 /*
 102  * Flag to indicate that we have received a window change signal which has
 103  * not yet been processed.  This will cause a message indicating the new
 104  * window size to be sent to the server a little later.  This is volatile
 105  * because this is updated in a signal handler.
 106  */
 107 static volatile sig_atomic_t received_window_change_signal = 0;
 108 static volatile sig_atomic_t received_signal = 0;
 109
 110 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
 111 static int in_non_blocking_mode = 0;
 112
 113 /* Common data for the client loop code. */
 114 static int quit_pending;        /* Set to non-zero to quit the client loop. */
 115 static int escape_char;         /* Escape character. */
 116 static int escape_pending;      /* Last character was the escape character */
 117 static int last_was_cr;         /* Last character was a newline. */
 118 static int exit_status;         /* Used to store the exit status of the command. */
 119 static int stdin_eof;           /* EOF has been encountered on standard error. */
 120 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 121 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 122 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 123 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 124 static u_int buffer_high;/* Soft max buffer size. */
 125 static int connection_in;       /* Connection to server (input). */
 126 static int connection_out;      /* Connection to server (output). */
 127 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 128 static int session_closed = 0;  /* In SSH2: login session closed. */
 129 static int server_alive_timeouts = 0;
 130
 131 static void client_init_dispatch(void);
 132 int     session_ident = -1;
 133
 134 /*XXX*/
 135 extern Kex *xxx_kex;
 136
 137 /* Restores stdin to blocking mode. */
 138
 139 static void
 140 leave_non_blocking(void)
 141 {
 142         if (in_non_blocking_mode) {
 143                 (void) fcntl(fileno(stdin), F_SETFL, 0);
 144                 in_non_blocking_mode = 0;
 145         }
 146 }
 147
 148 /* Puts stdin terminal in non-blocking mode. */
 149
 150 static void
 151 enter_non_blocking(void)
 152 {
 153         in_non_blocking_mode = 1;
 154         (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
 155 }
 156
 157 /*
 158  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 159  * flag indicating that the window has changed.
 160  */
 161
 162 static void
 163 window_change_handler(int sig)
 164 {
 165         received_window_change_signal = 1;
 166         signal(SIGWINCH, window_change_handler);
 167 }
 168
 169 /*
 170  * Signal handler for signals that cause the program to terminate.  These
 171  * signals must be trapped to restore terminal modes.
 172  */
 173
 174 static void
 175 signal_handler(int sig)
 176 {
 177         received_signal = sig;
 178         quit_pending = 1;
 179 }
 180
 181 /*
 182  * Returns current time in seconds from Jan 1, 1970 with the maximum
 183  * available resolution.
 184  */
 185
 186 static double
 187 get_current_time(void)
 188 {
 189         struct timeval tv;
 190         gettimeofday(&tv, NULL);
 191         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 192 }
 193
 194 /*
 195  * This is called when the interactive is entered.  This checks if there is
 196  * an EOF coming on stdin.  We must check this explicitly, as select() does
 197  * not appear to wake up when redirecting from /dev/null.
 198  */
 199
 200 static void
 201 client_check_initial_eof_on_stdin(void)
 202 {
 203         int len;
 204         char buf[1];
 205
 206         /*
 207          * If standard input is to be "redirected from /dev/null", we simply
 208          * mark that we have seen an EOF and send an EOF message to the
 209          * server. Otherwise, we try to read a single character; it appears
 210          * that for some files, such /dev/null, select() never wakes up for
 211          * read for this descriptor, which means that we never get EOF.  This
 212          * way we will get the EOF if stdin comes from /dev/null or similar.
 213          */
 214         if (stdin_null_flag) {
 215                 /* Fake EOF on stdin. */
 216                 debug("Sending eof.");
 217                 stdin_eof = 1;
 218                 packet_start(SSH_CMSG_EOF);
 219                 packet_send();
 220         } else {
 221                 enter_non_blocking();
 222
 223                 /* Check for immediate EOF on stdin. */
 224                 len = read(fileno(stdin), buf, 1);
 225                 if (len == 0) {
 226                         /* EOF.  Record that we have seen it and send EOF to server. */
 227                         debug("Sending eof.");
 228                         stdin_eof = 1;
 229                         packet_start(SSH_CMSG_EOF);
 230                         packet_send();
 231                 } else if (len > 0) {
 232                         /*
 233                          * Got data.  We must store the data in the buffer,
 234                          * and also process it as an escape character if
 235                          * appropriate.
 236                          */
 237                         if ((u_char) buf[0] == escape_char)
 238                                 escape_pending = 1;
 239                         else
 240                                 buffer_append(&stdin_buffer, buf, 1);
 241                 }
 242                 leave_non_blocking();
 243         }
 244 }
 245
 246
 247 /*
 248  * Make packets from buffered stdin data, and buffer them for sending to the
 249  * connection.
 250  */
 251
 252 static void
 253 client_make_packets_from_stdin_data(void)
 254 {
 255         u_int len;
 256
 257         /* Send buffered stdin data to the server. */
 258         while (buffer_len(&stdin_buffer) > 0 &&
 259             packet_not_very_much_data_to_write()) {
 260                 len = buffer_len(&stdin_buffer);
 261                 /* Keep the packets at reasonable size. */
 262                 if (len > packet_get_maxsize())
 263                         len = packet_get_maxsize();
 264                 packet_start(SSH_CMSG_STDIN_DATA);
 265                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 266                 packet_send();
 267                 buffer_consume(&stdin_buffer, len);
 268                 stdin_bytes += len;
 269                 /* If we have a pending EOF, send it now. */
 270                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 271                         packet_start(SSH_CMSG_EOF);
 272                         packet_send();
 273                 }
 274         }
 275 }
 276
 277 /*
 278  * Checks if the client window has changed, and sends a packet about it to
 279  * the server if so.  The actual change is detected elsewhere (by a software
 280  * interrupt on Unix); this just checks the flag and sends a message if
 281  * appropriate.
 282  */
 283
 284 static void
 285 client_check_window_change(void)
 286 {
 287         struct winsize ws;
 288
 289         if (! received_window_change_signal)
 290                 return;
 291         /** XXX race */
 292         received_window_change_signal = 0;
 293
 294         if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 295                 return;
 296
 297         debug2("client_check_window_change: changed");
 298
 299         if (compat20) {
 300                 channel_request_start(session_ident, "window-change", 0);
 301                 packet_put_int(ws.ws_col);
 302                 packet_put_int(ws.ws_row);
 303                 packet_put_int(ws.ws_xpixel);
 304                 packet_put_int(ws.ws_ypixel);
 305                 packet_send();
 306         } else {
 307                 packet_start(SSH_CMSG_WINDOW_SIZE);
 308                 packet_put_int(ws.ws_row);
 309                 packet_put_int(ws.ws_col);
 310                 packet_put_int(ws.ws_xpixel);
 311                 packet_put_int(ws.ws_ypixel);
 312                 packet_send();
 313         }
 314 }
 315
 316 static void
 317 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 318 {
 319         server_alive_timeouts = 0;
 320         client_global_request_reply_fwd(type, seq, ctxt);
 321 }
 322
 323 static void
 324 server_alive_check(void)
 325 {
 326         if (++server_alive_timeouts > options.server_alive_count_max)
 327                 packet_disconnect("Timeout, server not responding.");
 328         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 329         packet_put_cstring("keepalive@openssh.com");
 330         packet_put_char(1);     /* boolean: want reply */
 331         packet_send();
 332 }
 333
 334 /*
 335  * Waits until the client can do something (some data becomes available on
 336  * one of the file descriptors).
 337  */
 338
 339 static void
 340 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 341     int *maxfdp, int *nallocp, int rekeying)
 342 {
 343         struct timeval tv, *tvp;
 344         int ret;
 345
 346         /* Add any selections by the channel mechanism. */
 347         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 348
 349         if (!compat20) {
 350                 /* Read from the connection, unless our buffers are full. */
 351                 if (buffer_len(&stdout_buffer) < buffer_high &&
 352                     buffer_len(&stderr_buffer) < buffer_high &&
 353                     channel_not_very_much_buffered_data())
 354                         FD_SET(connection_in, *readsetp);
 355                 /*
 356                  * Read from stdin, unless we have seen EOF or have very much
 357                  * buffered data to send to the server.
 358                  */
 359                 if (!stdin_eof && packet_not_very_much_data_to_write())
 360                         FD_SET(fileno(stdin), *readsetp);
 361
 362                 /* Select stdout/stderr if have data in buffer. */
 363                 if (buffer_len(&stdout_buffer) > 0)
 364                         FD_SET(fileno(stdout), *writesetp);
 365                 if (buffer_len(&stderr_buffer) > 0)
 366                         FD_SET(fileno(stderr), *writesetp);
 367         } else {
 368                 /* channel_prepare_select could have closed the last channel */
 369                 if (session_closed && !channel_still_open() &&
 370                     !packet_have_data_to_write()) {
 371                         /* clear mask since we did not call select() */
 372                         memset(*readsetp, 0, *nallocp);
 373                         memset(*writesetp, 0, *nallocp);
 374                         return;
 375                 } else {
 376                         FD_SET(connection_in, *readsetp);
 377                 }
 378         }
 379
 380         /* Select server connection if have data to write to the server. */
 381         if (packet_have_data_to_write())
 382                 FD_SET(connection_out, *writesetp);
 383
 384         /*
 385          * Wait for something to happen.  This will suspend the process until
 386          * some selected descriptor can be read, written, or has some other
 387          * event pending.
 388          */
 389
 390         if (options.server_alive_interval == 0 || !compat20)
 391                 tvp = NULL;
 392         else {
 393                 tv.tv_sec = options.server_alive_interval;
 394                 tv.tv_usec = 0;
 395                 tvp = &tv;
 396         }
 397         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 398         if (ret < 0) {
 399                 char buf[100];
 400
 401                 /*
 402                  * We have to clear the select masks, because we return.
 403                  * We have to return, because the mainloop checks for the flags
 404                  * set by the signal handlers.
 405                  */
 406                 memset(*readsetp, 0, *nallocp);
 407                 memset(*writesetp, 0, *nallocp);
 408
 409                 if (errno == EINTR)
 410                         return;
 411                 /* Note: we might still have data in the buffers. */
 412                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 413                 buffer_append(&stderr_buffer, buf, strlen(buf));
 414                 quit_pending = 1;
 415         } else if (ret == 0)
 416                 server_alive_check();
 417 }
 418
 419 static void
 420 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 421 {
 422         struct winsize oldws, newws;
 423
 424         /* Flush stdout and stderr buffers. */
 425         if (buffer_len(bout) > 0)
 426                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 427         if (buffer_len(berr) > 0)
 428                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 429
 430         leave_raw_mode();
 431
 432         /*
 433          * Free (and clear) the buffer to reduce the amount of data that gets
 434          * written to swap.
 435          */
 436         buffer_free(bin);
 437         buffer_free(bout);
 438         buffer_free(berr);
 439
 440         /* Save old window size. */
 441         ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
 442
 443         /* Send the suspend signal to the program itself. */
 444         kill(getpid(), SIGTSTP);
 445
 446         /* Check if the window size has changed. */
 447         if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
 448             (oldws.ws_row != newws.ws_row ||
 449             oldws.ws_col != newws.ws_col ||
 450             oldws.ws_xpixel != newws.ws_xpixel ||
 451             oldws.ws_ypixel != newws.ws_ypixel))
 452                 received_window_change_signal = 1;
 453
 454         /* OK, we have been continued by the user. Reinitialize buffers. */
 455         buffer_init(bin);
 456         buffer_init(bout);
 457         buffer_init(berr);
 458
 459         enter_raw_mode();
 460 }
 461
 462 static void
 463 client_process_net_input(fd_set * readset)
 464 {
 465         int len;
 466         char buf[8192];
 467
 468         /*
 469          * Read input from the server, and add any such data to the buffer of
 470          * the packet subsystem.
 471          */
 472         if (FD_ISSET(connection_in, readset)) {
 473                 /* Read as much as possible. */
 474                 len = read(connection_in, buf, sizeof(buf));
 475                 if (len == 0) {
 476                         /* Received EOF.  The remote host has closed the connection. */
 477                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 478                                  host);
 479                         buffer_append(&stderr_buffer, buf, strlen(buf));
 480                         quit_pending = 1;
 481                         return;
 482                 }
 483                 /*
 484                  * There is a kernel bug on Solaris that causes select to
 485                  * sometimes wake up even though there is no data available.
 486                  */
 487                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 488                         len = 0;
 489
 490                 if (len < 0) {
 491                         /* An error has encountered.  Perhaps there is a network problem. */
 492                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 493                                  host, strerror(errno));
 494                         buffer_append(&stderr_buffer, buf, strlen(buf));
 495                         quit_pending = 1;
 496                         return;
 497                 }
 498                 packet_process_incoming(buf, len);
 499         }
 500 }
 501
 502 static void
 503 process_cmdline(void)
 504 {
 505         void (*handler)(int);
 506         char *s, *cmd;
 507         u_short fwd_port, fwd_host_port;
 508         char buf[1024], sfwd_port[6], sfwd_host_port[6];
 509         int local = 0;
 510
 511         leave_raw_mode();
 512         handler = signal(SIGINT, SIG_IGN);
 513         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 514         if (s == NULL)
 515                 goto out;
 516         while (*s && isspace(*s))
 517                 s++;
 518         if (*s == '\0')
 519                 goto out;
 520         if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) {
 521                 logit("Invalid command.");
 522                 goto out;
 523         }
 524         if (s[1] == 'L')
 525                 local = 1;
 526         if (!local && !compat20) {
 527                 logit("Not supported for SSH protocol version 1.");
 528                 goto out;
 529         }
 530         s += 2;
 531         while (*s && isspace(*s))
 532                 s++;
 533
 534         if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
 535             sfwd_port, buf, sfwd_host_port) != 3 &&
 536             sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
 537             sfwd_port, buf, sfwd_host_port) != 3) {
 538                 logit("Bad forwarding specification.");
 539                 goto out;
 540         }
 541         if ((fwd_port = a2port(sfwd_port)) == 0 ||
 542             (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 543                 logit("Bad forwarding port(s).");
 544                 goto out;
 545         }
 546         if (local) {
 547                 if (channel_setup_local_fwd_listener(fwd_port, buf,
 548                     fwd_host_port, options.gateway_ports) < 0) {
 549                         logit("Port forwarding failed.");
 550                         goto out;
 551                 }
 552         } else
 553                 channel_request_remote_forwarding(fwd_port, buf,
 554                     fwd_host_port);
 555         logit("Forwarding port.");
 556 out:
 557         signal(SIGINT, handler);
 558         enter_raw_mode();
 559         if (cmd)
 560                 xfree(cmd);
 561 }
 562
 563 /* process the characters one by one */
 564 static int
 565 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
 566 {
 567         char string[1024];
 568         pid_t pid;
 569         int bytes = 0;
 570         u_int i;
 571         u_char ch;
 572         char *s;
 573
 574         for (i = 0; i < len; i++) {
 575                 /* Get one character at a time. */
 576                 ch = buf[i];
 577
 578                 if (escape_pending) {
 579                         /* We have previously seen an escape character. */
 580                         /* Clear the flag now. */
 581                         escape_pending = 0;
 582
 583                         /* Process the escaped character. */
 584                         switch (ch) {
 585                         case '.':
 586                                 /* Terminate the connection. */
 587                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
 588                                 buffer_append(berr, string, strlen(string));
 589
 590                                 quit_pending = 1;
 591                                 return -1;
 592
 593                         case 'Z' - 64:
 594                                 /* Suspend the program. */
 595                                 /* Print a message to that effect to the user. */
 596                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
 597                                 buffer_append(berr, string, strlen(string));
 598
 599                                 /* Restore terminal modes and suspend. */
 600                                 client_suspend_self(bin, bout, berr);
 601
 602                                 /* We have been continued. */
 603                                 continue;
 604
 605                         case 'B':
 606                                 if (compat20) {
 607                                         snprintf(string, sizeof string,
 608                                             "%cB\r\n", escape_char);
 609                                         buffer_append(berr, string,
 610                                             strlen(string));
 611                                         channel_request_start(session_ident,
 612                                             "break", 0);
 613                                         packet_put_int(1000);
 614                                         packet_send();
 615                                 }
 616                                 continue;
 617
 618                         case 'R':
 619                                 if (compat20) {
 620                                         if (datafellows & SSH_BUG_NOREKEY)
 621                                                 logit("Server does not support re-keying");
 622                                         else
 623                                                 need_rekeying = 1;
 624                                 }
 625                                 continue;
 626
 627                         case '&':
 628                                 /*
 629                                  * Detach the program (continue to serve connections,
 630                                  * but put in background and no more new connections).
 631                                  */
 632                                 /* Restore tty modes. */
 633                                 leave_raw_mode();
 634
 635                                 /* Stop listening for new connections. */
 636                                 channel_stop_listening();
 637
 638                                 snprintf(string, sizeof string,
 639                                     "%c& [backgrounded]\n", escape_char);
 640                                 buffer_append(berr, string, strlen(string));
 641
 642                                 /* Fork into background. */
 643                                 pid = fork();
 644                                 if (pid < 0) {
 645                                         error("fork: %.100s", strerror(errno));
 646                                         continue;
 647                                 }
 648                                 if (pid != 0) { /* This is the parent. */
 649                                         /* The parent just exits. */
 650                                         exit(0);
 651                                 }
 652                                 /* The child continues serving connections. */
 653                                 if (compat20) {
 654                                         buffer_append(bin, "\004", 1);
 655                                         /* fake EOF on stdin */
 656                                         return -1;
 657                                 } else if (!stdin_eof) {
 658                                         /*
 659                                          * Sending SSH_CMSG_EOF alone does not always appear
 660                                          * to be enough.  So we try to send an EOF character
 661                                          * first.
 662                                          */
 663                                         packet_start(SSH_CMSG_STDIN_DATA);
 664                                         packet_put_string("\004", 1);
 665                                         packet_send();
 666                                         /* Close stdin. */
 667                                         stdin_eof = 1;
 668                                         if (buffer_len(bin) == 0) {
 669                                                 packet_start(SSH_CMSG_EOF);
 670                                                 packet_send();
 671                                         }
 672                                 }
 673                                 continue;
 674
 675                         case '?':
 676                                 snprintf(string, sizeof string,
 677 "%c?\r\n\
 678 Supported escape sequences:\r\n\
 679 %c.  - terminate connection\r\n\
 680 %cB  - send a BREAK to the remote system\r\n\
 681 %cC  - open a command line\r\n\
 682 %cR  - Request rekey (SSH protocol 2 only)\r\n\
 683 %c^Z - suspend ssh\r\n\
 684 %c#  - list forwarded connections\r\n\
 685 %c&  - background ssh (when waiting for connections to terminate)\r\n\
 686 %c?  - this message\r\n\
 687 %c%c  - send the escape character by typing it twice\r\n\
 688 (Note that escapes are only recognized immediately after newline.)\r\n",
 689                                     escape_char, escape_char, escape_char, escape_char,
 690                                     escape_char, escape_char, escape_char, escape_char,
 691                                     escape_char, escape_char, escape_char);
 692                                 buffer_append(berr, string, strlen(string));
 693                                 continue;
 694
 695                         case '#':
 696                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
 697                                 buffer_append(berr, string, strlen(string));
 698                                 s = channel_open_message();
 699                                 buffer_append(berr, s, strlen(s));
 700                                 xfree(s);
 701                                 continue;
 702
 703                         case 'C':
 704                                 process_cmdline();
 705                                 continue;
 706
 707                         default:
 708                                 if (ch != escape_char) {
 709                                         buffer_put_char(bin, escape_char);
 710                                         bytes++;
 711                                 }
 712                                 /* Escaped characters fall through here */
 713                                 break;
 714                         }
 715                 } else {
 716                         /*
 717                          * The previous character was not an escape char. Check if this
 718                          * is an escape.
 719                          */
 720                         if (last_was_cr && ch == escape_char) {
 721                                 /* It is. Set the flag and continue to next character. */
 722                                 escape_pending = 1;
 723                                 continue;
 724                         }
 725                 }
 726
 727                 /*
 728                  * Normal character.  Record whether it was a newline,
 729                  * and append it to the buffer.
 730                  */
 731                 last_was_cr = (ch == '\r' || ch == '\n');
 732                 buffer_put_char(bin, ch);
 733                 bytes++;
 734         }
 735         return bytes;
 736 }
 737
 738 static void
 739 client_process_input(fd_set * readset)
 740 {
 741         int len;
 742         char buf[8192];
 743
 744         /* Read input from stdin. */
 745         if (FD_ISSET(fileno(stdin), readset)) {
 746                 /* Read as much as possible. */
 747                 len = read(fileno(stdin), buf, sizeof(buf));
 748                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 749                         return;         /* we'll try again later */
 750                 if (len <= 0) {
 751                         /*
 752                          * Received EOF or error.  They are treated
 753                          * similarly, except that an error message is printed
 754                          * if it was an error condition.
 755                          */
 756                         if (len < 0) {
 757                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
 758                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 759                         }
 760                         /* Mark that we have seen EOF. */
 761                         stdin_eof = 1;
 762                         /*
 763                          * Send an EOF message to the server unless there is
 764                          * data in the buffer.  If there is data in the
 765                          * buffer, no message will be sent now.  Code
 766                          * elsewhere will send the EOF when the buffer
 767                          * becomes empty if stdin_eof is set.
 768                          */
 769                         if (buffer_len(&stdin_buffer) == 0) {
 770                                 packet_start(SSH_CMSG_EOF);
 771                                 packet_send();
 772                         }
 773                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
 774                         /*
 775                          * Normal successful read, and no escape character.
 776                          * Just append the data to buffer.
 777                          */
 778                         buffer_append(&stdin_buffer, buf, len);
 779                 } else {
 780                         /*
 781                          * Normal, successful read.  But we have an escape character
 782                          * and have to process the characters one by one.
 783                          */
 784                         if (process_escapes(&stdin_buffer, &stdout_buffer,
 785                             &stderr_buffer, buf, len) == -1)
 786                                 return;
 787                 }
 788         }
 789 }
 790
 791 static void
 792 client_process_output(fd_set * writeset)
 793 {
 794         int len;
 795         char buf[100];
 796
 797         /* Write buffered output to stdout. */
 798         if (FD_ISSET(fileno(stdout), writeset)) {
 799                 /* Write as much data as possible. */
 800                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
 801                     buffer_len(&stdout_buffer));
 802                 if (len <= 0) {
 803                         if (errno == EINTR || errno == EAGAIN)
 804                                 len = 0;
 805                         else {
 806                                 /*
 807                                  * An error or EOF was encountered.  Put an
 808                                  * error message to stderr buffer.
 809                                  */
 810                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
 811                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 812                                 quit_pending = 1;
 813                                 return;
 814                         }
 815                 }
 816                 /* Consume printed data from the buffer. */
 817                 buffer_consume(&stdout_buffer, len);
 818                 stdout_bytes += len;
 819         }
 820         /* Write buffered output to stderr. */
 821         if (FD_ISSET(fileno(stderr), writeset)) {
 822                 /* Write as much data as possible. */
 823                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
 824                     buffer_len(&stderr_buffer));
 825                 if (len <= 0) {
 826                         if (errno == EINTR || errno == EAGAIN)
 827                                 len = 0;
 828                         else {
 829                                 /* EOF or error, but can't even print error message. */
 830                                 quit_pending = 1;
 831                                 return;
 832                         }
 833                 }
 834                 /* Consume printed characters from the buffer. */
 835                 buffer_consume(&stderr_buffer, len);
 836                 stderr_bytes += len;
 837         }
 838 }
 839
 840 /*
 841  * Get packets from the connection input buffer, and process them as long as
 842  * there are packets available.
 843  *
 844  * Any unknown packets received during the actual
 845  * session cause the session to terminate.  This is
 846  * intended to make debugging easier since no
 847  * confirmations are sent.  Any compatible protocol
 848  * extensions must be negotiated during the
 849  * preparatory phase.
 850  */
 851
 852 static void
 853 client_process_buffered_input_packets(void)
 854 {
 855         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
 856 }
 857
 858 /* scan buf[] for '~' before sending data to the peer */
 859
 860 static int
 861 simple_escape_filter(Channel *c, char *buf, int len)
 862 {
 863         /* XXX we assume c->extended is writeable */
 864         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
 865 }
 866
 867 static void
 868 client_channel_closed(int id, void *arg)
 869 {
 870         if (id != session_ident)
 871                 error("client_channel_closed: id %d != session_ident %d",
 872                     id, session_ident);
 873         channel_cancel_cleanup(id);
 874         session_closed = 1;
 875         leave_raw_mode();
 876 }
 877
 878 /*
 879  * Implements the interactive session with the server.  This is called after
 880  * the user has been authenticated, and a command has been started on the
 881  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
 882  * used as an escape character for terminating or suspending the session.
 883  */
 884
 885 int
 886 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 887 {
 888         fd_set *readset = NULL, *writeset = NULL;
 889         double start_time, total_time;
 890         int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
 891         char buf[100];
 892
 893         debug("Entering interactive session.");
 894
 895         start_time = get_current_time();
 896
 897         /* Initialize variables. */
 898         escape_pending = 0;
 899         last_was_cr = 1;
 900         exit_status = -1;
 901         stdin_eof = 0;
 902         buffer_high = 64 * 1024;
 903         connection_in = packet_get_connection_in();
 904         connection_out = packet_get_connection_out();
 905         max_fd = MAX(connection_in, connection_out);
 906
 907         if (!compat20) {
 908                 /* enable nonblocking unless tty */
 909                 if (!isatty(fileno(stdin)))
 910                         set_nonblock(fileno(stdin));
 911                 if (!isatty(fileno(stdout)))
 912                         set_nonblock(fileno(stdout));
 913                 if (!isatty(fileno(stderr)))
 914                         set_nonblock(fileno(stderr));
 915                 max_fd = MAX(max_fd, fileno(stdin));
 916                 max_fd = MAX(max_fd, fileno(stdout));
 917                 max_fd = MAX(max_fd, fileno(stderr));
 918         }
 919         stdin_bytes = 0;
 920         stdout_bytes = 0;
 921         stderr_bytes = 0;
 922         quit_pending = 0;
 923         escape_char = escape_char_arg;
 924
 925         /* Initialize buffers. */
 926         buffer_init(&stdin_buffer);
 927         buffer_init(&stdout_buffer);
 928         buffer_init(&stderr_buffer);
 929
 930         client_init_dispatch();
 931
 932         /*
 933          * Set signal handlers, (e.g. to restore non-blocking mode)
 934          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
 935          */
 936         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
 937                 signal(SIGINT, signal_handler);
 938         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
 939                 signal(SIGQUIT, signal_handler);
 940         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
 941                 signal(SIGTERM, signal_handler);
 942         if (have_pty)
 943                 signal(SIGWINCH, window_change_handler);
 944
 945         if (have_pty)
 946                 enter_raw_mode();
 947
 948         if (compat20) {
 949                 session_ident = ssh2_chan_id;
 950                 if (escape_char != SSH_ESCAPECHAR_NONE)
 951                         channel_register_filter(session_ident,
 952                             simple_escape_filter);
 953                 if (session_ident != -1)
 954                         channel_register_cleanup(session_ident,
 955                             client_channel_closed);
 956         } else {
 957                 /* Check if we should immediately send eof on stdin. */
 958                 client_check_initial_eof_on_stdin();
 959         }
 960
 961         /* Main loop of the client for the interactive session mode. */
 962         while (!quit_pending) {
 963
 964                 /* Process buffered packets sent by the server. */
 965                 client_process_buffered_input_packets();
 966
 967                 if (compat20 && session_closed && !channel_still_open())
 968                         break;
 969
 970                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 971
 972                 if (rekeying) {
 973                         debug("rekeying in progress");
 974                 } else {
 975                         /*
 976                          * Make packets of buffered stdin data, and buffer
 977                          * them for sending to the server.
 978                          */
 979                         if (!compat20)
 980                                 client_make_packets_from_stdin_data();
 981
 982                         /*
 983                          * Make packets from buffered channel data, and
 984                          * enqueue them for sending to the server.
 985                          */
 986                         if (packet_not_very_much_data_to_write())
 987                                 channel_output_poll();
 988
 989                         /*
 990                          * Check if the window size has changed, and buffer a
 991                          * message about it to the server if so.
 992                          */
 993                         client_check_window_change();
 994
 995                         if (quit_pending)
 996                                 break;
 997                 }
 998                 /*
 999                  * Wait until we have something to do (something becomes
1000                  * available on one of the descriptors).
1001                  */
1002                 max_fd2 = max_fd;
1003                 client_wait_until_can_do_something(&readset, &writeset,
1004                     &max_fd2, &nalloc, rekeying);
1005
1006                 if (quit_pending)
1007                         break;
1008
1009                 /* Do channel operations unless rekeying in progress. */
1010                 if (!rekeying) {
1011                         channel_after_select(readset, writeset);
1012                         if (need_rekeying || packet_need_rekeying()) {
1013                                 debug("need rekeying");
1014                                 xxx_kex->done = 0;
1015                                 kex_send_kexinit(xxx_kex);
1016                                 need_rekeying = 0;
1017                         }
1018                 }
1019
1020                 /* Buffer input from the connection.  */
1021                 client_process_net_input(readset);
1022
1023                 if (quit_pending)
1024                         break;
1025
1026                 if (!compat20) {
1027                         /* Buffer data from stdin */
1028                         client_process_input(readset);
1029                         /*
1030                          * Process output to stdout and stderr.  Output to
1031                          * the connection is processed elsewhere (above).
1032                          */
1033                         client_process_output(writeset);
1034                 }
1035
1036                 /* Send as much buffered packet data as possible to the sender. */
1037                 if (FD_ISSET(connection_out, writeset))
1038                         packet_write_poll();
1039         }
1040         if (readset)
1041                 xfree(readset);
1042         if (writeset)
1043                 xfree(writeset);
1044
1045         /* Terminate the session. */
1046
1047         /* Stop watching for window change. */
1048         if (have_pty)
1049                 signal(SIGWINCH, SIG_DFL);
1050
1051         channel_free_all();
1052
1053         if (have_pty)
1054                 leave_raw_mode();
1055
1056         /* restore blocking io */
1057         if (!isatty(fileno(stdin)))
1058                 unset_nonblock(fileno(stdin));
1059         if (!isatty(fileno(stdout)))
1060                 unset_nonblock(fileno(stdout));
1061         if (!isatty(fileno(stderr)))
1062                 unset_nonblock(fileno(stderr));
1063
1064         /*
1065          * If there was no shell or command requested, there will be no remote
1066          * exit status to be returned.  In that case, clear error code if the
1067          * connection was deliberately terminated at this end.
1068          */
1069         if (no_shell_flag && received_signal == SIGTERM) {
1070                 received_signal = 0;
1071                 exit_status = 0;
1072         }
1073
1074         if (received_signal)
1075                 fatal("Killed by signal %d.", (int) received_signal);
1076
1077         /*
1078          * In interactive mode (with pseudo tty) display a message indicating
1079          * that the connection has been closed.
1080          */
1081         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1082                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1083                 buffer_append(&stderr_buffer, buf, strlen(buf));
1084         }
1085
1086         /* Output any buffered data for stdout. */
1087         while (buffer_len(&stdout_buffer) > 0) {
1088                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1089                     buffer_len(&stdout_buffer));
1090                 if (len <= 0) {
1091                         error("Write failed flushing stdout buffer.");
1092                         break;
1093                 }
1094                 buffer_consume(&stdout_buffer, len);
1095                 stdout_bytes += len;
1096         }
1097
1098         /* Output any buffered data for stderr. */
1099         while (buffer_len(&stderr_buffer) > 0) {
1100                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1101                     buffer_len(&stderr_buffer));
1102                 if (len <= 0) {
1103                         error("Write failed flushing stderr buffer.");
1104                         break;
1105                 }
1106                 buffer_consume(&stderr_buffer, len);
1107                 stderr_bytes += len;
1108         }
1109
1110         /* Clear and free any buffers. */
1111         memset(buf, 0, sizeof(buf));
1112         buffer_free(&stdin_buffer);
1113         buffer_free(&stdout_buffer);
1114         buffer_free(&stderr_buffer);
1115
1116         /* Report bytes transferred, and transfer rates. */
1117         total_time = get_current_time() - start_time;
1118         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1119             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1120         if (total_time > 0)
1121                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1122                     stdin_bytes / total_time, stdout_bytes / total_time,
1123                     stderr_bytes / total_time);
1124
1125         /* Return the exit status of the program. */
1126         debug("Exit status %d", exit_status);
1127         return exit_status;
1128 }
1129
1130 /*********/
1131
1132 static void
1133 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1134 {
1135         u_int data_len;
1136         char *data = packet_get_string(&data_len);
1137         packet_check_eom();
1138         buffer_append(&stdout_buffer, data, data_len);
1139         memset(data, 0, data_len);
1140         xfree(data);
1141 }
1142 static void
1143 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1144 {
1145         u_int data_len;
1146         char *data = packet_get_string(&data_len);
1147         packet_check_eom();
1148         buffer_append(&stderr_buffer, data, data_len);
1149         memset(data, 0, data_len);
1150         xfree(data);
1151 }
1152 static void
1153 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1154 {
1155         exit_status = packet_get_int();
1156         packet_check_eom();
1157         /* Acknowledge the exit. */
1158         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1159         packet_send();
1160         /*
1161          * Must wait for packet to be sent since we are
1162          * exiting the loop.
1163          */
1164         packet_write_wait();
1165         /* Flag that we want to exit. */
1166         quit_pending = 1;
1167 }
1168 static void
1169 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1170 {
1171         Channel *c = NULL;
1172         int remote_id, sock;
1173
1174         /* Read the remote channel number from the message. */
1175         remote_id = packet_get_int();
1176         packet_check_eom();
1177
1178         /*
1179          * Get a connection to the local authentication agent (this may again
1180          * get forwarded).
1181          */
1182         sock = ssh_get_authentication_socket();
1183
1184         /*
1185          * If we could not connect the agent, send an error message back to
1186          * the server. This should never happen unless the agent dies,
1187          * because authentication forwarding is only enabled if we have an
1188          * agent.
1189          */
1190         if (sock >= 0) {
1191                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1192                     -1, 0, 0, 0, "authentication agent connection", 1);
1193                 c->remote_id = remote_id;
1194                 c->force_drain = 1;
1195         }
1196         if (c == NULL) {
1197                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1198                 packet_put_int(remote_id);
1199         } else {
1200                 /* Send a confirmation to the remote host. */
1201                 debug("Forwarding authentication connection.");
1202                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1203                 packet_put_int(remote_id);
1204                 packet_put_int(c->self);
1205         }
1206         packet_send();
1207 }
1208
1209 static Channel *
1210 client_request_forwarded_tcpip(const char *request_type, int rchan)
1211 {
1212         Channel *c = NULL;
1213         char *listen_address, *originator_address;
1214         int listen_port, originator_port;
1215         int sock;
1216
1217         /* Get rest of the packet */
1218         listen_address = packet_get_string(NULL);
1219         listen_port = packet_get_int();
1220         originator_address = packet_get_string(NULL);
1221         originator_port = packet_get_int();
1222         packet_check_eom();
1223
1224         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1225             listen_address, listen_port, originator_address, originator_port);
1226
1227         sock = channel_connect_by_listen_address(listen_port);
1228         if (sock < 0) {
1229                 xfree(originator_address);
1230                 xfree(listen_address);
1231                 return NULL;
1232         }
1233         c = channel_new("forwarded-tcpip",
1234             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1235             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1236             originator_address, 1);
1237         xfree(originator_address);
1238         xfree(listen_address);
1239         return c;
1240 }
1241
1242 static Channel *
1243 client_request_x11(const char *request_type, int rchan)
1244 {
1245         Channel *c = NULL;
1246         char *originator;
1247         int originator_port;
1248         int sock;
1249
1250         if (!options.forward_x11) {
1251                 error("Warning: ssh server tried X11 forwarding.");
1252                 error("Warning: this is probably a break in attempt by a malicious server.");
1253                 return NULL;
1254         }
1255         originator = packet_get_string(NULL);
1256         if (datafellows & SSH_BUG_X11FWD) {
1257                 debug2("buggy server: x11 request w/o originator_port");
1258                 originator_port = 0;
1259         } else {
1260                 originator_port = packet_get_int();
1261         }
1262         packet_check_eom();
1263         /* XXX check permission */
1264         debug("client_request_x11: request from %s %d", originator,
1265             originator_port);
1266         xfree(originator);
1267         sock = x11_connect_display();
1268         if (sock < 0)
1269                 return NULL;
1270         c = channel_new("x11",
1271             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1272             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1273         c->force_drain = 1;
1274         return c;
1275 }
1276
1277 static Channel *
1278 client_request_agent(const char *request_type, int rchan)
1279 {
1280         Channel *c = NULL;
1281         int sock;
1282
1283         if (!options.forward_agent) {
1284                 error("Warning: ssh server tried agent forwarding.");
1285                 error("Warning: this is probably a break in attempt by a malicious server.");
1286                 return NULL;
1287         }
1288         sock =  ssh_get_authentication_socket();
1289         if (sock < 0)
1290                 return NULL;
1291         c = channel_new("authentication agent connection",
1292             SSH_CHANNEL_OPEN, sock, sock, -1,
1293             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1294             "authentication agent connection", 1);
1295         c->force_drain = 1;
1296         return c;
1297 }
1298
1299 /* XXXX move to generic input handler */
1300 static void
1301 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1302 {
1303         Channel *c = NULL;
1304         char *ctype;
1305         int rchan;
1306         u_int rmaxpack, rwindow, len;
1307
1308         ctype = packet_get_string(&len);
1309         rchan = packet_get_int();
1310         rwindow = packet_get_int();
1311         rmaxpack = packet_get_int();
1312
1313         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1314             ctype, rchan, rwindow, rmaxpack);
1315
1316         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1317                 c = client_request_forwarded_tcpip(ctype, rchan);
1318         } else if (strcmp(ctype, "x11") == 0) {
1319                 c = client_request_x11(ctype, rchan);
1320         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1321                 c = client_request_agent(ctype, rchan);
1322         }
1323 /* XXX duplicate : */
1324         if (c != NULL) {
1325                 debug("confirm %s", ctype);
1326                 c->remote_id = rchan;
1327                 c->remote_window = rwindow;
1328                 c->remote_maxpacket = rmaxpack;
1329                 if (c->type != SSH_CHANNEL_CONNECTING) {
1330                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1331                         packet_put_int(c->remote_id);
1332                         packet_put_int(c->self);
1333                         packet_put_int(c->local_window);
1334                         packet_put_int(c->local_maxpacket);
1335                         packet_send();
1336                 }
1337         } else {
1338                 debug("failure %s", ctype);
1339                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1340                 packet_put_int(rchan);
1341                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1342                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1343                         packet_put_cstring("open failed");
1344                         packet_put_cstring("");
1345                 }
1346                 packet_send();
1347         }
1348         xfree(ctype);
1349 }
1350 static void
1351 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1352 {
1353         Channel *c = NULL;
1354         int id, reply, success = 0;
1355         char *rtype;
1356
1357         id = packet_get_int();
1358         rtype = packet_get_string(NULL);
1359         reply = packet_get_char();
1360
1361         debug("client_input_channel_req: channel %d rtype %s reply %d",
1362             id, rtype, reply);
1363
1364         if (session_ident == -1) {
1365                 error("client_input_channel_req: no channel %d", session_ident);
1366         } else if (id != session_ident) {
1367                 error("client_input_channel_req: channel %d: wrong channel: %d",
1368                     session_ident, id);
1369         }
1370         c = channel_lookup(id);
1371         if (c == NULL) {
1372                 error("client_input_channel_req: channel %d: unknown channel", id);
1373         } else if (strcmp(rtype, "exit-status") == 0) {
1374                 success = 1;
1375                 exit_status = packet_get_int();
1376                 packet_check_eom();
1377         }
1378         if (reply) {
1379                 packet_start(success ?
1380                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1381                 packet_put_int(c->remote_id);
1382                 packet_send();
1383         }
1384         xfree(rtype);
1385 }
1386 static void
1387 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1388 {
1389         char *rtype;
1390         int want_reply;
1391         int success = 0;
1392
1393         rtype = packet_get_string(NULL);
1394         want_reply = packet_get_char();
1395         debug("client_input_global_request: rtype %s want_reply %d",
1396             rtype, want_reply);
1397         if (want_reply) {
1398                 packet_start(success ?
1399                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1400                 packet_send();
1401                 packet_write_wait();
1402         }
1403         xfree(rtype);
1404 }
1405
1406 static void
1407 client_init_dispatch_20(void)
1408 {
1409         dispatch_init(&dispatch_protocol_error);
1410
1411         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1412         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1413         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1414         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1415         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1416         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1417         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1418         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1419         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1420         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1421
1422         /* rekeying */
1423         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1424
1425         /* global request reply messages */
1426         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1427         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1428 }
1429 static void
1430 client_init_dispatch_13(void)
1431 {
1432         dispatch_init(NULL);
1433         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1434         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1435         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1436         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1437         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1438         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1439         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1440         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1441         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1442
1443         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1444             &client_input_agent_open : &deny_input_open);
1445         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1446             &x11_input_open : &deny_input_open);
1447 }
1448 static void
1449 client_init_dispatch_15(void)
1450 {
1451         client_init_dispatch_13();
1452         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1453         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1454 }
1455 static void
1456 client_init_dispatch(void)
1457 {
1458         if (compat20)
1459                 client_init_dispatch_20();
1460         else if (compat13)
1461                 client_init_dispatch_13();
1462         else
1463                 client_init_dispatch_15();
1464 }
1465
1466 /* client specific fatal cleanup */
1467 void
1468 cleanup_exit(int i)
1469 {
1470         leave_raw_mode();
1471         leave_non_blocking();
1472         _exit(i);
1473 }