openssh/clientloop.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * The main loop for the interactive session (client side).
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  *
  13  *
  14  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  *
  37  * SSH2 support added by Markus Friedl.
  38  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  59  */
  60
  61 #include "includes.h"
  62 RCSID("$OpenBSD: clientloop.c,v 1.117 2003/12/16 15:49:51 markus Exp $");
  63
  64 #include "ssh.h"
  65 #include "ssh1.h"
  66 #include "ssh2.h"
  67 #include "xmalloc.h"
  68 #include "packet.h"
  69 #include "buffer.h"
  70 #include "compat.h"
  71 #include "channels.h"
  72 #include "dispatch.h"
  73 #include "buffer.h"
  74 #include "bufaux.h"
  75 #include "key.h"
  76 #include "kex.h"
  77 #include "log.h"
  78 #include "readconf.h"
  79 #include "clientloop.h"
  80 #include "authfd.h"
  81 #include "atomicio.h"
  82 #include "sshtty.h"
  83 #include "misc.h"
  84 #include "readpass.h"
  85
  86 /* import options */
  87 extern Options options;
  88
  89 /* Flag indicating that stdin should be redirected from /dev/null. */
  90 extern int stdin_null_flag;
  91
  92 /* Flag indicating that no shell has been requested */
  93 extern int no_shell_flag;
  94
  95 /*
  96  * Name of the host we are connecting to.  This is the name given on the
  97  * command line, or the HostName specified for the user-supplied name in a
  98  * configuration file.
  99  */
 100 extern char *host;
 101
 102 /*
 103  * Flag to indicate that we have received a window change signal which has
 104  * not yet been processed.  This will cause a message indicating the new
 105  * window size to be sent to the server a little later.  This is volatile
 106  * because this is updated in a signal handler.
 107  */
 108 static volatile sig_atomic_t received_window_change_signal = 0;
 109 static volatile sig_atomic_t received_signal = 0;
 110
 111 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
 112 static int in_non_blocking_mode = 0;
 113
 114 /* Common data for the client loop code. */
 115 static int quit_pending;        /* Set to non-zero to quit the client loop. */
 116 static int escape_char;         /* Escape character. */
 117 static int escape_pending;      /* Last character was the escape character */
 118 static int last_was_cr;         /* Last character was a newline. */
 119 static int exit_status;         /* Used to store the exit status of the command. */
 120 static int stdin_eof;           /* EOF has been encountered on standard error. */
 121 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 122 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 123 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 124 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 125 static u_int buffer_high;/* Soft max buffer size. */
 126 static int connection_in;       /* Connection to server (input). */
 127 static int connection_out;      /* Connection to server (output). */
 128 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 129 static int session_closed = 0;  /* In SSH2: login session closed. */
 130 static int server_alive_timeouts = 0;
 131
 132 static void client_init_dispatch(void);
 133 int     session_ident = -1;
 134
 135 /*XXX*/
 136 extern Kex *xxx_kex;
 137
 138 /* Restores stdin to blocking mode. */
 139
 140 static void
 141 leave_non_blocking(void)
 142 {
 143         if (in_non_blocking_mode) {
 144                 (void) fcntl(fileno(stdin), F_SETFL, 0);
 145                 in_non_blocking_mode = 0;
 146         }
 147 }
 148
 149 /* Puts stdin terminal in non-blocking mode. */
 150
 151 static void
 152 enter_non_blocking(void)
 153 {
 154         in_non_blocking_mode = 1;
 155         (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
 156 }
 157
 158 /*
 159  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 160  * flag indicating that the window has changed.
 161  */
 162
 163 static void
 164 window_change_handler(int sig)
 165 {
 166         received_window_change_signal = 1;
 167         signal(SIGWINCH, window_change_handler);
 168 }
 169
 170 /*
 171  * Signal handler for signals that cause the program to terminate.  These
 172  * signals must be trapped to restore terminal modes.
 173  */
 174
 175 static void
 176 signal_handler(int sig)
 177 {
 178         received_signal = sig;
 179         quit_pending = 1;
 180 }
 181
 182 /*
 183  * Returns current time in seconds from Jan 1, 1970 with the maximum
 184  * available resolution.
 185  */
 186
 187 static double
 188 get_current_time(void)
 189 {
 190         struct timeval tv;
 191         gettimeofday(&tv, NULL);
 192         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 193 }
 194
 195 /*
 196  * This is called when the interactive is entered.  This checks if there is
 197  * an EOF coming on stdin.  We must check this explicitly, as select() does
 198  * not appear to wake up when redirecting from /dev/null.
 199  */
 200
 201 static void
 202 client_check_initial_eof_on_stdin(void)
 203 {
 204         int len;
 205         char buf[1];
 206
 207         /*
 208          * If standard input is to be "redirected from /dev/null", we simply
 209          * mark that we have seen an EOF and send an EOF message to the
 210          * server. Otherwise, we try to read a single character; it appears
 211          * that for some files, such /dev/null, select() never wakes up for
 212          * read for this descriptor, which means that we never get EOF.  This
 213          * way we will get the EOF if stdin comes from /dev/null or similar.
 214          */
 215         if (stdin_null_flag) {
 216                 /* Fake EOF on stdin. */
 217                 debug("Sending eof.");
 218                 stdin_eof = 1;
 219                 packet_start(SSH_CMSG_EOF);
 220                 packet_send();
 221         } else {
 222                 enter_non_blocking();
 223
 224                 /* Check for immediate EOF on stdin. */
 225                 len = read(fileno(stdin), buf, 1);
 226                 if (len == 0) {
 227                         /* EOF.  Record that we have seen it and send EOF to server. */
 228                         debug("Sending eof.");
 229                         stdin_eof = 1;
 230                         packet_start(SSH_CMSG_EOF);
 231                         packet_send();
 232                 } else if (len > 0) {
 233                         /*
 234                          * Got data.  We must store the data in the buffer,
 235                          * and also process it as an escape character if
 236                          * appropriate.
 237                          */
 238                         if ((u_char) buf[0] == escape_char)
 239                                 escape_pending = 1;
 240                         else
 241                                 buffer_append(&stdin_buffer, buf, 1);
 242                 }
 243                 leave_non_blocking();
 244         }
 245 }
 246
 247
 248 /*
 249  * Make packets from buffered stdin data, and buffer them for sending to the
 250  * connection.
 251  */
 252
 253 static void
 254 client_make_packets_from_stdin_data(void)
 255 {
 256         u_int len;
 257
 258         /* Send buffered stdin data to the server. */
 259         while (buffer_len(&stdin_buffer) > 0 &&
 260             packet_not_very_much_data_to_write()) {
 261                 len = buffer_len(&stdin_buffer);
 262                 /* Keep the packets at reasonable size. */
 263                 if (len > packet_get_maxsize())
 264                         len = packet_get_maxsize();
 265                 packet_start(SSH_CMSG_STDIN_DATA);
 266                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 267                 packet_send();
 268                 buffer_consume(&stdin_buffer, len);
 269                 stdin_bytes += len;
 270                 /* If we have a pending EOF, send it now. */
 271                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 272                         packet_start(SSH_CMSG_EOF);
 273                         packet_send();
 274                 }
 275         }
 276 }
 277
 278 /*
 279  * Checks if the client window has changed, and sends a packet about it to
 280  * the server if so.  The actual change is detected elsewhere (by a software
 281  * interrupt on Unix); this just checks the flag and sends a message if
 282  * appropriate.
 283  */
 284
 285 static void
 286 client_check_window_change(void)
 287 {
 288         struct winsize ws;
 289
 290         if (! received_window_change_signal)
 291                 return;
 292         /** XXX race */
 293         received_window_change_signal = 0;
 294
 295         if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 296                 return;
 297
 298         debug2("client_check_window_change: changed");
 299
 300         if (compat20) {
 301                 channel_request_start(session_ident, "window-change", 0);
 302                 packet_put_int(ws.ws_col);
 303                 packet_put_int(ws.ws_row);
 304                 packet_put_int(ws.ws_xpixel);
 305                 packet_put_int(ws.ws_ypixel);
 306                 packet_send();
 307         } else {
 308                 packet_start(SSH_CMSG_WINDOW_SIZE);
 309                 packet_put_int(ws.ws_row);
 310                 packet_put_int(ws.ws_col);
 311                 packet_put_int(ws.ws_xpixel);
 312                 packet_put_int(ws.ws_ypixel);
 313                 packet_send();
 314         }
 315 }
 316
 317 static void
 318 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 319 {
 320         server_alive_timeouts = 0;
 321         client_global_request_reply_fwd(type, seq, ctxt);
 322 }
 323
 324 static void
 325 server_alive_check(void)
 326 {
 327         if (++server_alive_timeouts > options.server_alive_count_max)
 328                 packet_disconnect("Timeout, server not responding.");
 329         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 330         packet_put_cstring("keepalive@openssh.com");
 331         packet_put_char(1);     /* boolean: want reply */
 332         packet_send();
 333 }
 334
 335 /*
 336  * Waits until the client can do something (some data becomes available on
 337  * one of the file descriptors).
 338  */
 339
 340 static void
 341 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 342     int *maxfdp, int *nallocp, int rekeying)
 343 {
 344         struct timeval tv, *tvp;
 345         int ret;
 346
 347         /* Add any selections by the channel mechanism. */
 348         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 349
 350         if (!compat20) {
 351                 /* Read from the connection, unless our buffers are full. */
 352                 if (buffer_len(&stdout_buffer) < buffer_high &&
 353                     buffer_len(&stderr_buffer) < buffer_high &&
 354                     channel_not_very_much_buffered_data())
 355                         FD_SET(connection_in, *readsetp);
 356                 /*
 357                  * Read from stdin, unless we have seen EOF or have very much
 358                  * buffered data to send to the server.
 359                  */
 360                 if (!stdin_eof && packet_not_very_much_data_to_write())
 361                         FD_SET(fileno(stdin), *readsetp);
 362
 363                 /* Select stdout/stderr if have data in buffer. */
 364                 if (buffer_len(&stdout_buffer) > 0)
 365                         FD_SET(fileno(stdout), *writesetp);
 366                 if (buffer_len(&stderr_buffer) > 0)
 367                         FD_SET(fileno(stderr), *writesetp);
 368         } else {
 369                 /* channel_prepare_select could have closed the last channel */
 370                 if (session_closed && !channel_still_open() &&
 371                     !packet_have_data_to_write()) {
 372                         /* clear mask since we did not call select() */
 373                         memset(*readsetp, 0, *nallocp);
 374                         memset(*writesetp, 0, *nallocp);
 375                         return;
 376                 } else {
 377                         FD_SET(connection_in, *readsetp);
 378                 }
 379         }
 380
 381         /* Select server connection if have data to write to the server. */
 382         if (packet_have_data_to_write())
 383                 FD_SET(connection_out, *writesetp);
 384
 385         /*
 386          * Wait for something to happen.  This will suspend the process until
 387          * some selected descriptor can be read, written, or has some other
 388          * event pending.
 389          */
 390
 391         if (options.server_alive_interval == 0 || !compat20)
 392                 tvp = NULL;
 393         else {
 394                 tv.tv_sec = options.server_alive_interval;
 395                 tv.tv_usec = 0;
 396                 tvp = &tv;
 397         }
 398         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 399         if (ret < 0) {
 400                 char buf[100];
 401
 402                 /*
 403                  * We have to clear the select masks, because we return.
 404                  * We have to return, because the mainloop checks for the flags
 405                  * set by the signal handlers.
 406                  */
 407                 memset(*readsetp, 0, *nallocp);
 408                 memset(*writesetp, 0, *nallocp);
 409
 410                 if (errno == EINTR)
 411                         return;
 412                 /* Note: we might still have data in the buffers. */
 413                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 414                 buffer_append(&stderr_buffer, buf, strlen(buf));
 415                 quit_pending = 1;
 416         } else if (ret == 0)
 417                 server_alive_check();
 418 }
 419
 420 static void
 421 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 422 {
 423         struct winsize oldws, newws;
 424
 425         /* Flush stdout and stderr buffers. */
 426         if (buffer_len(bout) > 0)
 427                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 428         if (buffer_len(berr) > 0)
 429                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 430
 431         leave_raw_mode();
 432
 433         /*
 434          * Free (and clear) the buffer to reduce the amount of data that gets
 435          * written to swap.
 436          */
 437         buffer_free(bin);
 438         buffer_free(bout);
 439         buffer_free(berr);
 440
 441         /* Save old window size. */
 442         ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
 443
 444         /* Send the suspend signal to the program itself. */
 445         kill(getpid(), SIGTSTP);
 446
 447         /* Check if the window size has changed. */
 448         if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
 449             (oldws.ws_row != newws.ws_row ||
 450             oldws.ws_col != newws.ws_col ||
 451             oldws.ws_xpixel != newws.ws_xpixel ||
 452             oldws.ws_ypixel != newws.ws_ypixel))
 453                 received_window_change_signal = 1;
 454
 455         /* OK, we have been continued by the user. Reinitialize buffers. */
 456         buffer_init(bin);
 457         buffer_init(bout);
 458         buffer_init(berr);
 459
 460         enter_raw_mode();
 461 }
 462
 463 static void
 464 client_process_net_input(fd_set * readset)
 465 {
 466         int len;
 467         char buf[8192];
 468
 469         /*
 470          * Read input from the server, and add any such data to the buffer of
 471          * the packet subsystem.
 472          */
 473         if (FD_ISSET(connection_in, readset)) {
 474                 /* Read as much as possible. */
 475                 len = read(connection_in, buf, sizeof(buf));
 476                 if (len == 0) {
 477                         /* Received EOF.  The remote host has closed the connection. */
 478                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 479                                  host);
 480                         buffer_append(&stderr_buffer, buf, strlen(buf));
 481                         quit_pending = 1;
 482                         return;
 483                 }
 484                 /*
 485                  * There is a kernel bug on Solaris that causes select to
 486                  * sometimes wake up even though there is no data available.
 487                  */
 488                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 489                         len = 0;
 490
 491                 if (len < 0) {
 492                         /* An error has encountered.  Perhaps there is a network problem. */
 493                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 494                                  host, strerror(errno));
 495                         buffer_append(&stderr_buffer, buf, strlen(buf));
 496                         quit_pending = 1;
 497                         return;
 498                 }
 499                 packet_process_incoming(buf, len);
 500         }
 501 }
 502
 503 static void
 504 process_cmdline(void)
 505 {
 506         void (*handler)(int);
 507         char *s, *cmd;
 508         u_short fwd_port, fwd_host_port;
 509         char buf[1024], sfwd_port[6], sfwd_host_port[6];
 510         int local = 0;
 511
 512         leave_raw_mode();
 513         handler = signal(SIGINT, SIG_IGN);
 514         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 515         if (s == NULL)
 516                 goto out;
 517         while (*s && isspace(*s))
 518                 s++;
 519         if (*s == 0)
 520                 goto out;
 521         if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) {
 522                 logit("Invalid command.");
 523                 goto out;
 524         }
 525         if (s[1] == 'L')
 526                 local = 1;
 527         if (!local && !compat20) {
 528                 logit("Not supported for SSH protocol version 1.");
 529                 goto out;
 530         }
 531         s += 2;
 532         while (*s && isspace(*s))
 533                 s++;
 534
 535         if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
 536             sfwd_port, buf, sfwd_host_port) != 3 &&
 537             sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
 538             sfwd_port, buf, sfwd_host_port) != 3) {
 539                 logit("Bad forwarding specification.");
 540                 goto out;
 541         }
 542         if ((fwd_port = a2port(sfwd_port)) == 0 ||
 543             (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 544                 logit("Bad forwarding port(s).");
 545                 goto out;
 546         }
 547         if (local) {
 548                 if (channel_setup_local_fwd_listener(fwd_port, buf,
 549                     fwd_host_port, options.gateway_ports) < 0) {
 550                         logit("Port forwarding failed.");
 551                         goto out;
 552                 }
 553         } else
 554                 channel_request_remote_forwarding(fwd_port, buf,
 555                     fwd_host_port);
 556         logit("Forwarding port.");
 557 out:
 558         signal(SIGINT, handler);
 559         enter_raw_mode();
 560         if (cmd)
 561                 xfree(cmd);
 562 }
 563
 564 /* process the characters one by one */
 565 static int
 566 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
 567 {
 568         char string[1024];
 569         pid_t pid;
 570         int bytes = 0;
 571         u_int i;
 572         u_char ch;
 573         char *s;
 574
 575         for (i = 0; i < len; i++) {
 576                 /* Get one character at a time. */
 577                 ch = buf[i];
 578
 579                 if (escape_pending) {
 580                         /* We have previously seen an escape character. */
 581                         /* Clear the flag now. */
 582                         escape_pending = 0;
 583
 584                         /* Process the escaped character. */
 585                         switch (ch) {
 586                         case '.':
 587                                 /* Terminate the connection. */
 588                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
 589                                 buffer_append(berr, string, strlen(string));
 590
 591                                 quit_pending = 1;
 592                                 return -1;
 593
 594                         case 'Z' - 64:
 595                                 /* Suspend the program. */
 596                                 /* Print a message to that effect to the user. */
 597                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
 598                                 buffer_append(berr, string, strlen(string));
 599
 600                                 /* Restore terminal modes and suspend. */
 601                                 client_suspend_self(bin, bout, berr);
 602
 603                                 /* We have been continued. */
 604                                 continue;
 605
 606                         case 'B':
 607                                 if (compat20) {
 608                                         snprintf(string, sizeof string,
 609                                             "%cB\r\n", escape_char);
 610                                         buffer_append(berr, string,
 611                                             strlen(string));
 612                                         channel_request_start(session_ident,
 613                                             "break", 0);
 614                                         packet_put_int(1000);
 615                                         packet_send();
 616                                 }
 617                                 continue;
 618
 619                         case 'R':
 620                                 if (compat20) {
 621                                         if (datafellows & SSH_BUG_NOREKEY)
 622                                                 logit("Server does not support re-keying");
 623                                         else
 624                                                 need_rekeying = 1;
 625                                 }
 626                                 continue;
 627
 628                         case '&':
 629                                 /*
 630                                  * Detach the program (continue to serve connections,
 631                                  * but put in background and no more new connections).
 632                                  */
 633                                 /* Restore tty modes. */
 634                                 leave_raw_mode();
 635
 636                                 /* Stop listening for new connections. */
 637                                 channel_stop_listening();
 638
 639                                 snprintf(string, sizeof string,
 640                                     "%c& [backgrounded]\n", escape_char);
 641                                 buffer_append(berr, string, strlen(string));
 642
 643                                 /* Fork into background. */
 644                                 pid = fork();
 645                                 if (pid < 0) {
 646                                         error("fork: %.100s", strerror(errno));
 647                                         continue;
 648                                 }
 649                                 if (pid != 0) { /* This is the parent. */
 650                                         /* The parent just exits. */
 651                                         exit(0);
 652                                 }
 653                                 /* The child continues serving connections. */
 654                                 if (compat20) {
 655                                         buffer_append(bin, "\004", 1);
 656                                         /* fake EOF on stdin */
 657                                         return -1;
 658                                 } else if (!stdin_eof) {
 659                                         /*
 660                                          * Sending SSH_CMSG_EOF alone does not always appear
 661                                          * to be enough.  So we try to send an EOF character
 662                                          * first.
 663                                          */
 664                                         packet_start(SSH_CMSG_STDIN_DATA);
 665                                         packet_put_string("\004", 1);
 666                                         packet_send();
 667                                         /* Close stdin. */
 668                                         stdin_eof = 1;
 669                                         if (buffer_len(bin) == 0) {
 670                                                 packet_start(SSH_CMSG_EOF);
 671                                                 packet_send();
 672                                         }
 673                                 }
 674                                 continue;
 675
 676                         case '?':
 677                                 snprintf(string, sizeof string,
 678 "%c?\r\n\
 679 Supported escape sequences:\r\n\
 680 %c.  - terminate connection\r\n\
 681 %cB  - send a BREAK to the remote system\r\n\
 682 %cC  - open a command line\r\n\
 683 %cR  - Request rekey (SSH protocol 2 only)\r\n\
 684 %c^Z - suspend ssh\r\n\
 685 %c#  - list forwarded connections\r\n\
 686 %c&  - background ssh (when waiting for connections to terminate)\r\n\
 687 %c?  - this message\r\n\
 688 %c%c  - send the escape character by typing it twice\r\n\
 689 (Note that escapes are only recognized immediately after newline.)\r\n",
 690                                     escape_char, escape_char, escape_char, escape_char,
 691                                     escape_char, escape_char, escape_char, escape_char,
 692                                     escape_char, escape_char, escape_char);
 693                                 buffer_append(berr, string, strlen(string));
 694                                 continue;
 695
 696                         case '#':
 697                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
 698                                 buffer_append(berr, string, strlen(string));
 699                                 s = channel_open_message();
 700                                 buffer_append(berr, s, strlen(s));
 701                                 xfree(s);
 702                                 continue;
 703
 704                         case 'C':
 705                                 process_cmdline();
 706                                 continue;
 707
 708                         default:
 709                                 if (ch != escape_char) {
 710                                         buffer_put_char(bin, escape_char);
 711                                         bytes++;
 712                                 }
 713                                 /* Escaped characters fall through here */
 714                                 break;
 715                         }
 716                 } else {
 717                         /*
 718                          * The previous character was not an escape char. Check if this
 719                          * is an escape.
 720                          */
 721                         if (last_was_cr && ch == escape_char) {
 722                                 /* It is. Set the flag and continue to next character. */
 723                                 escape_pending = 1;
 724                                 continue;
 725                         }
 726                 }
 727
 728                 /*
 729                  * Normal character.  Record whether it was a newline,
 730                  * and append it to the buffer.
 731                  */
 732                 last_was_cr = (ch == '\r' || ch == '\n');
 733                 buffer_put_char(bin, ch);
 734                 bytes++;
 735         }
 736         return bytes;
 737 }
 738
 739 static void
 740 client_process_input(fd_set * readset)
 741 {
 742         int len;
 743         char buf[8192];
 744
 745         /* Read input from stdin. */
 746         if (FD_ISSET(fileno(stdin), readset)) {
 747                 /* Read as much as possible. */
 748                 len = read(fileno(stdin), buf, sizeof(buf));
 749                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 750                         return;         /* we'll try again later */
 751                 if (len <= 0) {
 752                         /*
 753                          * Received EOF or error.  They are treated
 754                          * similarly, except that an error message is printed
 755                          * if it was an error condition.
 756                          */
 757                         if (len < 0) {
 758                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
 759                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 760                         }
 761                         /* Mark that we have seen EOF. */
 762                         stdin_eof = 1;
 763                         /*
 764                          * Send an EOF message to the server unless there is
 765                          * data in the buffer.  If there is data in the
 766                          * buffer, no message will be sent now.  Code
 767                          * elsewhere will send the EOF when the buffer
 768                          * becomes empty if stdin_eof is set.
 769                          */
 770                         if (buffer_len(&stdin_buffer) == 0) {
 771                                 packet_start(SSH_CMSG_EOF);
 772                                 packet_send();
 773                         }
 774                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
 775                         /*
 776                          * Normal successful read, and no escape character.
 777                          * Just append the data to buffer.
 778                          */
 779                         buffer_append(&stdin_buffer, buf, len);
 780                 } else {
 781                         /*
 782                          * Normal, successful read.  But we have an escape character
 783                          * and have to process the characters one by one.
 784                          */
 785                         if (process_escapes(&stdin_buffer, &stdout_buffer,
 786                             &stderr_buffer, buf, len) == -1)
 787                                 return;
 788                 }
 789         }
 790 }
 791
 792 static void
 793 client_process_output(fd_set * writeset)
 794 {
 795         int len;
 796         char buf[100];
 797
 798         /* Write buffered output to stdout. */
 799         if (FD_ISSET(fileno(stdout), writeset)) {
 800                 /* Write as much data as possible. */
 801                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
 802                     buffer_len(&stdout_buffer));
 803                 if (len <= 0) {
 804                         if (errno == EINTR || errno == EAGAIN)
 805                                 len = 0;
 806                         else {
 807                                 /*
 808                                  * An error or EOF was encountered.  Put an
 809                                  * error message to stderr buffer.
 810                                  */
 811                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
 812                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 813                                 quit_pending = 1;
 814                                 return;
 815                         }
 816                 }
 817                 /* Consume printed data from the buffer. */
 818                 buffer_consume(&stdout_buffer, len);
 819                 stdout_bytes += len;
 820         }
 821         /* Write buffered output to stderr. */
 822         if (FD_ISSET(fileno(stderr), writeset)) {
 823                 /* Write as much data as possible. */
 824                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
 825                     buffer_len(&stderr_buffer));
 826                 if (len <= 0) {
 827                         if (errno == EINTR || errno == EAGAIN)
 828                                 len = 0;
 829                         else {
 830                                 /* EOF or error, but can't even print error message. */
 831                                 quit_pending = 1;
 832                                 return;
 833                         }
 834                 }
 835                 /* Consume printed characters from the buffer. */
 836                 buffer_consume(&stderr_buffer, len);
 837                 stderr_bytes += len;
 838         }
 839 }
 840
 841 /*
 842  * Get packets from the connection input buffer, and process them as long as
 843  * there are packets available.
 844  *
 845  * Any unknown packets received during the actual
 846  * session cause the session to terminate.  This is
 847  * intended to make debugging easier since no
 848  * confirmations are sent.  Any compatible protocol
 849  * extensions must be negotiated during the
 850  * preparatory phase.
 851  */
 852
 853 static void
 854 client_process_buffered_input_packets(void)
 855 {
 856         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
 857 }
 858
 859 /* scan buf[] for '~' before sending data to the peer */
 860
 861 static int
 862 simple_escape_filter(Channel *c, char *buf, int len)
 863 {
 864         /* XXX we assume c->extended is writeable */
 865         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
 866 }
 867
 868 static void
 869 client_channel_closed(int id, void *arg)
 870 {
 871         if (id != session_ident)
 872                 error("client_channel_closed: id %d != session_ident %d",
 873                     id, session_ident);
 874         channel_cancel_cleanup(id);
 875         session_closed = 1;
 876         leave_raw_mode();
 877 }
 878
 879 /*
 880  * Implements the interactive session with the server.  This is called after
 881  * the user has been authenticated, and a command has been started on the
 882  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
 883  * used as an escape character for terminating or suspending the session.
 884  */
 885
 886 int
 887 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 888 {
 889         fd_set *readset = NULL, *writeset = NULL;
 890         double start_time, total_time;
 891         int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
 892         char buf[100];
 893
 894         debug("Entering interactive session.");
 895
 896         start_time = get_current_time();
 897
 898         /* Initialize variables. */
 899         escape_pending = 0;
 900         last_was_cr = 1;
 901         exit_status = -1;
 902         stdin_eof = 0;
 903         buffer_high = 64 * 1024;
 904         connection_in = packet_get_connection_in();
 905         connection_out = packet_get_connection_out();
 906         max_fd = MAX(connection_in, connection_out);
 907
 908         if (!compat20) {
 909                 /* enable nonblocking unless tty */
 910                 if (!isatty(fileno(stdin)))
 911                         set_nonblock(fileno(stdin));
 912                 if (!isatty(fileno(stdout)))
 913                         set_nonblock(fileno(stdout));
 914                 if (!isatty(fileno(stderr)))
 915                         set_nonblock(fileno(stderr));
 916                 max_fd = MAX(max_fd, fileno(stdin));
 917                 max_fd = MAX(max_fd, fileno(stdout));
 918                 max_fd = MAX(max_fd, fileno(stderr));
 919         }
 920         stdin_bytes = 0;
 921         stdout_bytes = 0;
 922         stderr_bytes = 0;
 923         quit_pending = 0;
 924         escape_char = escape_char_arg;
 925
 926         /* Initialize buffers. */
 927         buffer_init(&stdin_buffer);
 928         buffer_init(&stdout_buffer);
 929         buffer_init(&stderr_buffer);
 930
 931         client_init_dispatch();
 932
 933         /*
 934          * Set signal handlers, (e.g. to restore non-blocking mode)
 935          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
 936          */
 937         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
 938                 signal(SIGINT, signal_handler);
 939         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
 940                 signal(SIGQUIT, signal_handler);
 941         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
 942                 signal(SIGTERM, signal_handler);
 943         if (have_pty)
 944                 signal(SIGWINCH, window_change_handler);
 945
 946         if (have_pty)
 947                 enter_raw_mode();
 948
 949         if (compat20) {
 950                 session_ident = ssh2_chan_id;
 951                 if (escape_char != SSH_ESCAPECHAR_NONE)
 952                         channel_register_filter(session_ident,
 953                             simple_escape_filter);
 954                 if (session_ident != -1)
 955                         channel_register_cleanup(session_ident,
 956                             client_channel_closed);
 957         } else {
 958                 /* Check if we should immediately send eof on stdin. */
 959                 client_check_initial_eof_on_stdin();
 960         }
 961
 962         /* Main loop of the client for the interactive session mode. */
 963         while (!quit_pending) {
 964
 965                 /* Process buffered packets sent by the server. */
 966                 client_process_buffered_input_packets();
 967
 968                 if (compat20 && session_closed && !channel_still_open())
 969                         break;
 970
 971                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 972
 973                 if (rekeying) {
 974                         debug("rekeying in progress");
 975                 } else {
 976                         /*
 977                          * Make packets of buffered stdin data, and buffer
 978                          * them for sending to the server.
 979                          */
 980                         if (!compat20)
 981                                 client_make_packets_from_stdin_data();
 982
 983                         /*
 984                          * Make packets from buffered channel data, and
 985                          * enqueue them for sending to the server.
 986                          */
 987                         if (packet_not_very_much_data_to_write())
 988                                 channel_output_poll();
 989
 990                         /*
 991                          * Check if the window size has changed, and buffer a
 992                          * message about it to the server if so.
 993                          */
 994                         client_check_window_change();
 995
 996                         if (quit_pending)
 997                                 break;
 998                 }
 999                 /*
1000                  * Wait until we have something to do (something becomes
1001                  * available on one of the descriptors).
1002                  */
1003                 max_fd2 = max_fd;
1004                 client_wait_until_can_do_something(&readset, &writeset,
1005                     &max_fd2, &nalloc, rekeying);
1006
1007                 if (quit_pending)
1008                         break;
1009
1010                 /* Do channel operations unless rekeying in progress. */
1011                 if (!rekeying) {
1012                         channel_after_select(readset, writeset);
1013                         if (need_rekeying || packet_need_rekeying()) {
1014                                 debug("need rekeying");
1015                                 xxx_kex->done = 0;
1016                                 kex_send_kexinit(xxx_kex);
1017                                 need_rekeying = 0;
1018                         }
1019                 }
1020
1021                 /* Buffer input from the connection.  */
1022                 client_process_net_input(readset);
1023
1024                 if (quit_pending)
1025                         break;
1026
1027                 if (!compat20) {
1028                         /* Buffer data from stdin */
1029                         client_process_input(readset);
1030                         /*
1031                          * Process output to stdout and stderr.  Output to
1032                          * the connection is processed elsewhere (above).
1033                          */
1034                         client_process_output(writeset);
1035                 }
1036
1037                 /* Send as much buffered packet data as possible to the sender. */
1038                 if (FD_ISSET(connection_out, writeset))
1039                         packet_write_poll();
1040         }
1041         if (readset)
1042                 xfree(readset);
1043         if (writeset)
1044                 xfree(writeset);
1045
1046         /* Terminate the session. */
1047
1048         /* Stop watching for window change. */
1049         if (have_pty)
1050                 signal(SIGWINCH, SIG_DFL);
1051
1052         channel_free_all();
1053
1054         if (have_pty)
1055                 leave_raw_mode();
1056
1057         /* restore blocking io */
1058         if (!isatty(fileno(stdin)))
1059                 unset_nonblock(fileno(stdin));
1060         if (!isatty(fileno(stdout)))
1061                 unset_nonblock(fileno(stdout));
1062         if (!isatty(fileno(stderr)))
1063                 unset_nonblock(fileno(stderr));
1064
1065         /*
1066          * If there was no shell or command requested, there will be no remote
1067          * exit status to be returned.  In that case, clear error code if the
1068          * connection was deliberately terminated at this end.
1069          */
1070         if (no_shell_flag && received_signal == SIGTERM) {
1071                 received_signal = 0;
1072                 exit_status = 0;
1073         }
1074
1075         if (received_signal)
1076                 fatal("Killed by signal %d.", (int) received_signal);
1077
1078         /*
1079          * In interactive mode (with pseudo tty) display a message indicating
1080          * that the connection has been closed.
1081          */
1082         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1083                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1084                 buffer_append(&stderr_buffer, buf, strlen(buf));
1085         }
1086
1087         /* Output any buffered data for stdout. */
1088         while (buffer_len(&stdout_buffer) > 0) {
1089                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1090                     buffer_len(&stdout_buffer));
1091                 if (len <= 0) {
1092                         error("Write failed flushing stdout buffer.");
1093                         break;
1094                 }
1095                 buffer_consume(&stdout_buffer, len);
1096                 stdout_bytes += len;
1097         }
1098
1099         /* Output any buffered data for stderr. */
1100         while (buffer_len(&stderr_buffer) > 0) {
1101                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1102                     buffer_len(&stderr_buffer));
1103                 if (len <= 0) {
1104                         error("Write failed flushing stderr buffer.");
1105                         break;
1106                 }
1107                 buffer_consume(&stderr_buffer, len);
1108                 stderr_bytes += len;
1109         }
1110
1111         /* Clear and free any buffers. */
1112         memset(buf, 0, sizeof(buf));
1113         buffer_free(&stdin_buffer);
1114         buffer_free(&stdout_buffer);
1115         buffer_free(&stderr_buffer);
1116
1117         /* Report bytes transferred, and transfer rates. */
1118         total_time = get_current_time() - start_time;
1119         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1120             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1121         if (total_time > 0)
1122                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1123                     stdin_bytes / total_time, stdout_bytes / total_time,
1124                     stderr_bytes / total_time);
1125
1126         /* Return the exit status of the program. */
1127         debug("Exit status %d", exit_status);
1128         return exit_status;
1129 }
1130
1131 /*********/
1132
1133 static void
1134 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1135 {
1136         u_int data_len;
1137         char *data = packet_get_string(&data_len);
1138         packet_check_eom();
1139         buffer_append(&stdout_buffer, data, data_len);
1140         memset(data, 0, data_len);
1141         xfree(data);
1142 }
1143 static void
1144 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1145 {
1146         u_int data_len;
1147         char *data = packet_get_string(&data_len);
1148         packet_check_eom();
1149         buffer_append(&stderr_buffer, data, data_len);
1150         memset(data, 0, data_len);
1151         xfree(data);
1152 }
1153 static void
1154 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1155 {
1156         exit_status = packet_get_int();
1157         packet_check_eom();
1158         /* Acknowledge the exit. */
1159         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1160         packet_send();
1161         /*
1162          * Must wait for packet to be sent since we are
1163          * exiting the loop.
1164          */
1165         packet_write_wait();
1166         /* Flag that we want to exit. */
1167         quit_pending = 1;
1168 }
1169 static void
1170 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1171 {
1172         Channel *c = NULL;
1173         int remote_id, sock;
1174
1175         /* Read the remote channel number from the message. */
1176         remote_id = packet_get_int();
1177         packet_check_eom();
1178
1179         /*
1180          * Get a connection to the local authentication agent (this may again
1181          * get forwarded).
1182          */
1183         sock = ssh_get_authentication_socket();
1184
1185         /*
1186          * If we could not connect the agent, send an error message back to
1187          * the server. This should never happen unless the agent dies,
1188          * because authentication forwarding is only enabled if we have an
1189          * agent.
1190          */
1191         if (sock >= 0) {
1192                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1193                     -1, 0, 0, 0, "authentication agent connection", 1);
1194                 c->remote_id = remote_id;
1195                 c->force_drain = 1;
1196         }
1197         if (c == NULL) {
1198                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1199                 packet_put_int(remote_id);
1200         } else {
1201                 /* Send a confirmation to the remote host. */
1202                 debug("Forwarding authentication connection.");
1203                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1204                 packet_put_int(remote_id);
1205                 packet_put_int(c->self);
1206         }
1207         packet_send();
1208 }
1209
1210 static Channel *
1211 client_request_forwarded_tcpip(const char *request_type, int rchan)
1212 {
1213         Channel *c = NULL;
1214         char *listen_address, *originator_address;
1215         int listen_port, originator_port;
1216         int sock;
1217
1218         /* Get rest of the packet */
1219         listen_address = packet_get_string(NULL);
1220         listen_port = packet_get_int();
1221         originator_address = packet_get_string(NULL);
1222         originator_port = packet_get_int();
1223         packet_check_eom();
1224
1225         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1226             listen_address, listen_port, originator_address, originator_port);
1227
1228         sock = channel_connect_by_listen_address(listen_port);
1229         if (sock < 0) {
1230                 xfree(originator_address);
1231                 xfree(listen_address);
1232                 return NULL;
1233         }
1234         c = channel_new("forwarded-tcpip",
1235             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1236             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1237             originator_address, 1);
1238         xfree(originator_address);
1239         xfree(listen_address);
1240         return c;
1241 }
1242
1243 static Channel *
1244 client_request_x11(const char *request_type, int rchan)
1245 {
1246         Channel *c = NULL;
1247         char *originator;
1248         int originator_port;
1249         int sock;
1250
1251         if (!options.forward_x11) {
1252                 error("Warning: ssh server tried X11 forwarding.");
1253                 error("Warning: this is probably a break in attempt by a malicious server.");
1254                 return NULL;
1255         }
1256         originator = packet_get_string(NULL);
1257         if (datafellows & SSH_BUG_X11FWD) {
1258                 debug2("buggy server: x11 request w/o originator_port");
1259                 originator_port = 0;
1260         } else {
1261                 originator_port = packet_get_int();
1262         }
1263         packet_check_eom();
1264         /* XXX check permission */
1265         debug("client_request_x11: request from %s %d", originator,
1266             originator_port);
1267         xfree(originator);
1268         sock = x11_connect_display();
1269         if (sock < 0)
1270                 return NULL;
1271         c = channel_new("x11",
1272             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1273             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1274         c->force_drain = 1;
1275         return c;
1276 }
1277
1278 static Channel *
1279 client_request_agent(const char *request_type, int rchan)
1280 {
1281         Channel *c = NULL;
1282         int sock;
1283
1284         if (!options.forward_agent) {
1285                 error("Warning: ssh server tried agent forwarding.");
1286                 error("Warning: this is probably a break in attempt by a malicious server.");
1287                 return NULL;
1288         }
1289         sock =  ssh_get_authentication_socket();
1290         if (sock < 0)
1291                 return NULL;
1292         c = channel_new("authentication agent connection",
1293             SSH_CHANNEL_OPEN, sock, sock, -1,
1294             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1295             "authentication agent connection", 1);
1296         c->force_drain = 1;
1297         return c;
1298 }
1299
1300 /* XXXX move to generic input handler */
1301 static void
1302 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1303 {
1304         Channel *c = NULL;
1305         char *ctype;
1306         int rchan;
1307         u_int rmaxpack, rwindow, len;
1308
1309         ctype = packet_get_string(&len);
1310         rchan = packet_get_int();
1311         rwindow = packet_get_int();
1312         rmaxpack = packet_get_int();
1313
1314         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1315             ctype, rchan, rwindow, rmaxpack);
1316
1317         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1318                 c = client_request_forwarded_tcpip(ctype, rchan);
1319         } else if (strcmp(ctype, "x11") == 0) {
1320                 c = client_request_x11(ctype, rchan);
1321         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1322                 c = client_request_agent(ctype, rchan);
1323         }
1324 /* XXX duplicate : */
1325         if (c != NULL) {
1326                 debug("confirm %s", ctype);
1327                 c->remote_id = rchan;
1328                 c->remote_window = rwindow;
1329                 c->remote_maxpacket = rmaxpack;
1330                 if (c->type != SSH_CHANNEL_CONNECTING) {
1331                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1332                         packet_put_int(c->remote_id);
1333                         packet_put_int(c->self);
1334                         packet_put_int(c->local_window);
1335                         packet_put_int(c->local_maxpacket);
1336                         packet_send();
1337                 }
1338         } else {
1339                 debug("failure %s", ctype);
1340                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1341                 packet_put_int(rchan);
1342                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1343                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1344                         packet_put_cstring("open failed");
1345                         packet_put_cstring("");
1346                 }
1347                 packet_send();
1348         }
1349         xfree(ctype);
1350 }
1351 static void
1352 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1353 {
1354         Channel *c = NULL;
1355         int id, reply, success = 0;
1356         char *rtype;
1357
1358         id = packet_get_int();
1359         rtype = packet_get_string(NULL);
1360         reply = packet_get_char();
1361
1362         debug("client_input_channel_req: channel %d rtype %s reply %d",
1363             id, rtype, reply);
1364
1365         if (session_ident == -1) {
1366                 error("client_input_channel_req: no channel %d", session_ident);
1367         } else if (id != session_ident) {
1368                 error("client_input_channel_req: channel %d: wrong channel: %d",
1369                     session_ident, id);
1370         }
1371         c = channel_lookup(id);
1372         if (c == NULL) {
1373                 error("client_input_channel_req: channel %d: unknown channel", id);
1374         } else if (strcmp(rtype, "exit-status") == 0) {
1375                 success = 1;
1376                 exit_status = packet_get_int();
1377                 packet_check_eom();
1378         }
1379         if (reply) {
1380                 packet_start(success ?
1381                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1382                 packet_put_int(c->remote_id);
1383                 packet_send();
1384         }
1385         xfree(rtype);
1386 }
1387 static void
1388 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1389 {
1390         char *rtype;
1391         int want_reply;
1392         int success = 0;
1393
1394         rtype = packet_get_string(NULL);
1395         want_reply = packet_get_char();
1396         debug("client_input_global_request: rtype %s want_reply %d",
1397             rtype, want_reply);
1398         if (want_reply) {
1399                 packet_start(success ?
1400                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1401                 packet_send();
1402                 packet_write_wait();
1403         }
1404         xfree(rtype);
1405 }
1406
1407 static void
1408 client_init_dispatch_20(void)
1409 {
1410         dispatch_init(&dispatch_protocol_error);
1411
1412         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1413         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1414         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1415         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1416         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1417         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1418         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1419         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1420         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1421         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1422
1423         /* rekeying */
1424         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1425
1426         /* global request reply messages */
1427         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1428         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1429 }
1430 static void
1431 client_init_dispatch_13(void)
1432 {
1433         dispatch_init(NULL);
1434         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1435         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1436         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1437         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1438         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1439         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1440         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1441         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1442         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1443
1444         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1445             &client_input_agent_open : &deny_input_open);
1446         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1447             &x11_input_open : &deny_input_open);
1448 }
1449 static void
1450 client_init_dispatch_15(void)
1451 {
1452         client_init_dispatch_13();
1453         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1454         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1455 }
1456 static void
1457 client_init_dispatch(void)
1458 {
1459         if (compat20)
1460                 client_init_dispatch_20();
1461         else if (compat13)
1462                 client_init_dispatch_13();
1463         else
1464                 client_init_dispatch_15();
1465 }
1466
1467 /* client specific fatal cleanup */
1468 void
1469 cleanup_exit(int i)
1470 {
1471         leave_raw_mode();
1472         leave_non_blocking();
1473         _exit(i);
1474 }