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 1.122 2004/05/22 06:32:12 djm 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 delete = 0;
 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 == '-')
 520                 s++;    /* Skip cmdline '-', if any */
 521         if (*s == '\0')
 522                 goto out;
 523
 524         if (*s == 'h' || *s == 'H' || *s == '?') {
 525                 logit("Commands:");
 526                 logit("      -Lport:host:hostport    Request local forward");
 527                 logit("      -Rport:host:hostport    Request remote forward");
 528                 logit("      -KRhostport             Cancel remote forward");
 529                 goto out;
 530         }
 531
 532         if (*s == 'K') {
 533                 delete = 1;
 534                 s++;
 535         }
 536         if (*s != 'L' && *s != 'R') {
 537                 logit("Invalid command.");
 538                 goto out;
 539         }
 540         if (*s == 'L')
 541                 local = 1;
 542         if (local && delete) {
 543                 logit("Not supported.");
 544                 goto out;
 545         }
 546         if ((!local || delete) && !compat20) {
 547                 logit("Not supported for SSH protocol version 1.");
 548                 goto out;
 549         }
 550
 551         s++;
 552         while (*s && isspace(*s))
 553                 s++;
 554
 555         if (delete) {
 556                 if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
 557                         logit("Bad forwarding specification.");
 558                         goto out;
 559                 }
 560                 if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
 561                         logit("Bad forwarding port(s).");
 562                         goto out;
 563                 }
 564                 channel_request_rforward_cancel(fwd_host_port);
 565         } else {
 566                 if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
 567                     sfwd_port, buf, sfwd_host_port) != 3 &&
 568                     sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
 569                     sfwd_port, buf, sfwd_host_port) != 3) {
 570                         logit("Bad forwarding specification.");
 571                         goto out;
 572                 }
 573                 if ((fwd_port = a2port(sfwd_port)) == 0 ||
 574                     (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 575                         logit("Bad forwarding port(s).");
 576                         goto out;
 577                 }
 578                 if (local) {
 579                         if (channel_setup_local_fwd_listener(fwd_port, buf,
 580                             fwd_host_port, options.gateway_ports) < 0) {
 581                                 logit("Port forwarding failed.");
 582                                 goto out;
 583                         }
 584                 } else
 585                         channel_request_remote_forwarding(fwd_port, buf,
 586                             fwd_host_port);
 587                 logit("Forwarding port.");
 588         }
 589
 590 out:
 591         signal(SIGINT, handler);
 592         enter_raw_mode();
 593         if (cmd)
 594                 xfree(cmd);
 595 }
 596
 597 /* process the characters one by one */
 598 static int
 599 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
 600 {
 601         char string[1024];
 602         pid_t pid;
 603         int bytes = 0;
 604         u_int i;
 605         u_char ch;
 606         char *s;
 607
 608         for (i = 0; i < len; i++) {
 609                 /* Get one character at a time. */
 610                 ch = buf[i];
 611
 612                 if (escape_pending) {
 613                         /* We have previously seen an escape character. */
 614                         /* Clear the flag now. */
 615                         escape_pending = 0;
 616
 617                         /* Process the escaped character. */
 618                         switch (ch) {
 619                         case '.':
 620                                 /* Terminate the connection. */
 621                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
 622                                 buffer_append(berr, string, strlen(string));
 623
 624                                 quit_pending = 1;
 625                                 return -1;
 626
 627                         case 'Z' - 64:
 628                                 /* Suspend the program. */
 629                                 /* Print a message to that effect to the user. */
 630                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
 631                                 buffer_append(berr, string, strlen(string));
 632
 633                                 /* Restore terminal modes and suspend. */
 634                                 client_suspend_self(bin, bout, berr);
 635
 636                                 /* We have been continued. */
 637                                 continue;
 638
 639                         case 'B':
 640                                 if (compat20) {
 641                                         snprintf(string, sizeof string,
 642                                             "%cB\r\n", escape_char);
 643                                         buffer_append(berr, string,
 644                                             strlen(string));
 645                                         channel_request_start(session_ident,
 646                                             "break", 0);
 647                                         packet_put_int(1000);
 648                                         packet_send();
 649                                 }
 650                                 continue;
 651
 652                         case 'R':
 653                                 if (compat20) {
 654                                         if (datafellows & SSH_BUG_NOREKEY)
 655                                                 logit("Server does not support re-keying");
 656                                         else
 657                                                 need_rekeying = 1;
 658                                 }
 659                                 continue;
 660
 661                         case '&':
 662                                 /*
 663                                  * Detach the program (continue to serve connections,
 664                                  * but put in background and no more new connections).
 665                                  */
 666                                 /* Restore tty modes. */
 667                                 leave_raw_mode();
 668
 669                                 /* Stop listening for new connections. */
 670                                 channel_stop_listening();
 671
 672                                 snprintf(string, sizeof string,
 673                                     "%c& [backgrounded]\n", escape_char);
 674                                 buffer_append(berr, string, strlen(string));
 675
 676                                 /* Fork into background. */
 677                                 pid = fork();
 678                                 if (pid < 0) {
 679                                         error("fork: %.100s", strerror(errno));
 680                                         continue;
 681                                 }
 682                                 if (pid != 0) { /* This is the parent. */
 683                                         /* The parent just exits. */
 684                                         exit(0);
 685                                 }
 686                                 /* The child continues serving connections. */
 687                                 if (compat20) {
 688                                         buffer_append(bin, "\004", 1);
 689                                         /* fake EOF on stdin */
 690                                         return -1;
 691                                 } else if (!stdin_eof) {
 692                                         /*
 693                                          * Sending SSH_CMSG_EOF alone does not always appear
 694                                          * to be enough.  So we try to send an EOF character
 695                                          * first.
 696                                          */
 697                                         packet_start(SSH_CMSG_STDIN_DATA);
 698                                         packet_put_string("\004", 1);
 699                                         packet_send();
 700                                         /* Close stdin. */
 701                                         stdin_eof = 1;
 702                                         if (buffer_len(bin) == 0) {
 703                                                 packet_start(SSH_CMSG_EOF);
 704                                                 packet_send();
 705                                         }
 706                                 }
 707                                 continue;
 708
 709                         case '?':
 710                                 snprintf(string, sizeof string,
 711 "%c?\r\n\
 712 Supported escape sequences:\r\n\
 713 %c.  - terminate connection\r\n\
 714 %cB  - send a BREAK to the remote system\r\n\
 715 %cC  - open a command line\r\n\
 716 %cR  - Request rekey (SSH protocol 2 only)\r\n\
 717 %c^Z - suspend ssh\r\n\
 718 %c#  - list forwarded connections\r\n\
 719 %c&  - background ssh (when waiting for connections to terminate)\r\n\
 720 %c?  - this message\r\n\
 721 %c%c  - send the escape character by typing it twice\r\n\
 722 (Note that escapes are only recognized immediately after newline.)\r\n",
 723                                     escape_char, escape_char, escape_char, escape_char,
 724                                     escape_char, escape_char, escape_char, escape_char,
 725                                     escape_char, escape_char, escape_char);
 726                                 buffer_append(berr, string, strlen(string));
 727                                 continue;
 728
 729                         case '#':
 730                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
 731                                 buffer_append(berr, string, strlen(string));
 732                                 s = channel_open_message();
 733                                 buffer_append(berr, s, strlen(s));
 734                                 xfree(s);
 735                                 continue;
 736
 737                         case 'C':
 738                                 process_cmdline();
 739                                 continue;
 740
 741                         default:
 742                                 if (ch != escape_char) {
 743                                         buffer_put_char(bin, escape_char);
 744                                         bytes++;
 745                                 }
 746                                 /* Escaped characters fall through here */
 747                                 break;
 748                         }
 749                 } else {
 750                         /*
 751                          * The previous character was not an escape char. Check if this
 752                          * is an escape.
 753                          */
 754                         if (last_was_cr && ch == escape_char) {
 755                                 /* It is. Set the flag and continue to next character. */
 756                                 escape_pending = 1;
 757                                 continue;
 758                         }
 759                 }
 760
 761                 /*
 762                  * Normal character.  Record whether it was a newline,
 763                  * and append it to the buffer.
 764                  */
 765                 last_was_cr = (ch == '\r' || ch == '\n');
 766                 buffer_put_char(bin, ch);
 767                 bytes++;
 768         }
 769         return bytes;
 770 }
 771
 772 static void
 773 client_process_input(fd_set * readset)
 774 {
 775         int len;
 776         char buf[8192];
 777
 778         /* Read input from stdin. */
 779         if (FD_ISSET(fileno(stdin), readset)) {
 780                 /* Read as much as possible. */
 781                 len = read(fileno(stdin), buf, sizeof(buf));
 782                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 783                         return;         /* we'll try again later */
 784                 if (len <= 0) {
 785                         /*
 786                          * Received EOF or error.  They are treated
 787                          * similarly, except that an error message is printed
 788                          * if it was an error condition.
 789                          */
 790                         if (len < 0) {
 791                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
 792                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 793                         }
 794                         /* Mark that we have seen EOF. */
 795                         stdin_eof = 1;
 796                         /*
 797                          * Send an EOF message to the server unless there is
 798                          * data in the buffer.  If there is data in the
 799                          * buffer, no message will be sent now.  Code
 800                          * elsewhere will send the EOF when the buffer
 801                          * becomes empty if stdin_eof is set.
 802                          */
 803                         if (buffer_len(&stdin_buffer) == 0) {
 804                                 packet_start(SSH_CMSG_EOF);
 805                                 packet_send();
 806                         }
 807                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
 808                         /*
 809                          * Normal successful read, and no escape character.
 810                          * Just append the data to buffer.
 811                          */
 812                         buffer_append(&stdin_buffer, buf, len);
 813                 } else {
 814                         /*
 815                          * Normal, successful read.  But we have an escape character
 816                          * and have to process the characters one by one.
 817                          */
 818                         if (process_escapes(&stdin_buffer, &stdout_buffer,
 819                             &stderr_buffer, buf, len) == -1)
 820                                 return;
 821                 }
 822         }
 823 }
 824
 825 static void
 826 client_process_output(fd_set * writeset)
 827 {
 828         int len;
 829         char buf[100];
 830
 831         /* Write buffered output to stdout. */
 832         if (FD_ISSET(fileno(stdout), writeset)) {
 833                 /* Write as much data as possible. */
 834                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
 835                     buffer_len(&stdout_buffer));
 836                 if (len <= 0) {
 837                         if (errno == EINTR || errno == EAGAIN)
 838                                 len = 0;
 839                         else {
 840                                 /*
 841                                  * An error or EOF was encountered.  Put an
 842                                  * error message to stderr buffer.
 843                                  */
 844                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
 845                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 846                                 quit_pending = 1;
 847                                 return;
 848                         }
 849                 }
 850                 /* Consume printed data from the buffer. */
 851                 buffer_consume(&stdout_buffer, len);
 852                 stdout_bytes += len;
 853         }
 854         /* Write buffered output to stderr. */
 855         if (FD_ISSET(fileno(stderr), writeset)) {
 856                 /* Write as much data as possible. */
 857                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
 858                     buffer_len(&stderr_buffer));
 859                 if (len <= 0) {
 860                         if (errno == EINTR || errno == EAGAIN)
 861                                 len = 0;
 862                         else {
 863                                 /* EOF or error, but can't even print error message. */
 864                                 quit_pending = 1;
 865                                 return;
 866                         }
 867                 }
 868                 /* Consume printed characters from the buffer. */
 869                 buffer_consume(&stderr_buffer, len);
 870                 stderr_bytes += len;
 871         }
 872 }
 873
 874 /*
 875  * Get packets from the connection input buffer, and process them as long as
 876  * there are packets available.
 877  *
 878  * Any unknown packets received during the actual
 879  * session cause the session to terminate.  This is
 880  * intended to make debugging easier since no
 881  * confirmations are sent.  Any compatible protocol
 882  * extensions must be negotiated during the
 883  * preparatory phase.
 884  */
 885
 886 static void
 887 client_process_buffered_input_packets(void)
 888 {
 889         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
 890 }
 891
 892 /* scan buf[] for '~' before sending data to the peer */
 893
 894 static int
 895 simple_escape_filter(Channel *c, char *buf, int len)
 896 {
 897         /* XXX we assume c->extended is writeable */
 898         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
 899 }
 900
 901 static void
 902 client_channel_closed(int id, void *arg)
 903 {
 904         if (id != session_ident)
 905                 error("client_channel_closed: id %d != session_ident %d",
 906                     id, session_ident);
 907         channel_cancel_cleanup(id);
 908         session_closed = 1;
 909         leave_raw_mode();
 910 }
 911
 912 /*
 913  * Implements the interactive session with the server.  This is called after
 914  * the user has been authenticated, and a command has been started on the
 915  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
 916  * used as an escape character for terminating or suspending the session.
 917  */
 918
 919 int
 920 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 921 {
 922         fd_set *readset = NULL, *writeset = NULL;
 923         double start_time, total_time;
 924         int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
 925         char buf[100];
 926
 927         debug("Entering interactive session.");
 928
 929         start_time = get_current_time();
 930
 931         /* Initialize variables. */
 932         escape_pending = 0;
 933         last_was_cr = 1;
 934         exit_status = -1;
 935         stdin_eof = 0;
 936         buffer_high = 64 * 1024;
 937         connection_in = packet_get_connection_in();
 938         connection_out = packet_get_connection_out();
 939         max_fd = MAX(connection_in, connection_out);
 940
 941         if (!compat20) {
 942                 /* enable nonblocking unless tty */
 943                 if (!isatty(fileno(stdin)))
 944                         set_nonblock(fileno(stdin));
 945                 if (!isatty(fileno(stdout)))
 946                         set_nonblock(fileno(stdout));
 947                 if (!isatty(fileno(stderr)))
 948                         set_nonblock(fileno(stderr));
 949                 max_fd = MAX(max_fd, fileno(stdin));
 950                 max_fd = MAX(max_fd, fileno(stdout));
 951                 max_fd = MAX(max_fd, fileno(stderr));
 952         }
 953         stdin_bytes = 0;
 954         stdout_bytes = 0;
 955         stderr_bytes = 0;
 956         quit_pending = 0;
 957         escape_char = escape_char_arg;
 958
 959         /* Initialize buffers. */
 960         buffer_init(&stdin_buffer);
 961         buffer_init(&stdout_buffer);
 962         buffer_init(&stderr_buffer);
 963
 964         client_init_dispatch();
 965
 966         /*
 967          * Set signal handlers, (e.g. to restore non-blocking mode)
 968          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
 969          */
 970         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
 971                 signal(SIGINT, signal_handler);
 972         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
 973                 signal(SIGQUIT, signal_handler);
 974         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
 975                 signal(SIGTERM, signal_handler);
 976         if (have_pty)
 977                 signal(SIGWINCH, window_change_handler);
 978
 979         if (have_pty)
 980                 enter_raw_mode();
 981
 982         if (compat20) {
 983                 session_ident = ssh2_chan_id;
 984                 if (escape_char != SSH_ESCAPECHAR_NONE)
 985                         channel_register_filter(session_ident,
 986                             simple_escape_filter);
 987                 if (session_ident != -1)
 988                         channel_register_cleanup(session_ident,
 989                             client_channel_closed);
 990         } else {
 991                 /* Check if we should immediately send eof on stdin. */
 992                 client_check_initial_eof_on_stdin();
 993         }
 994
 995         /* Main loop of the client for the interactive session mode. */
 996         while (!quit_pending) {
 997
 998                 /* Process buffered packets sent by the server. */
 999                 client_process_buffered_input_packets();
1000
1001                 if (compat20 && session_closed && !channel_still_open())
1002                         break;
1003
1004                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1005
1006                 if (rekeying) {
1007                         debug("rekeying in progress");
1008                 } else {
1009                         /*
1010                          * Make packets of buffered stdin data, and buffer
1011                          * them for sending to the server.
1012                          */
1013                         if (!compat20)
1014                                 client_make_packets_from_stdin_data();
1015
1016                         /*
1017                          * Make packets from buffered channel data, and
1018                          * enqueue them for sending to the server.
1019                          */
1020                         if (packet_not_very_much_data_to_write())
1021                                 channel_output_poll();
1022
1023                         /*
1024                          * Check if the window size has changed, and buffer a
1025                          * message about it to the server if so.
1026                          */
1027                         client_check_window_change();
1028
1029                         if (quit_pending)
1030                                 break;
1031                 }
1032                 /*
1033                  * Wait until we have something to do (something becomes
1034                  * available on one of the descriptors).
1035                  */
1036                 max_fd2 = max_fd;
1037                 client_wait_until_can_do_something(&readset, &writeset,
1038                     &max_fd2, &nalloc, rekeying);
1039
1040                 if (quit_pending)
1041                         break;
1042
1043                 /* Do channel operations unless rekeying in progress. */
1044                 if (!rekeying) {
1045                         channel_after_select(readset, writeset);
1046                         if (need_rekeying || packet_need_rekeying()) {
1047                                 debug("need rekeying");
1048                                 xxx_kex->done = 0;
1049                                 kex_send_kexinit(xxx_kex);
1050                                 need_rekeying = 0;
1051                         }
1052                 }
1053
1054                 /* Buffer input from the connection.  */
1055                 client_process_net_input(readset);
1056
1057                 if (quit_pending)
1058                         break;
1059
1060                 if (!compat20) {
1061                         /* Buffer data from stdin */
1062                         client_process_input(readset);
1063                         /*
1064                          * Process output to stdout and stderr.  Output to
1065                          * the connection is processed elsewhere (above).
1066                          */
1067                         client_process_output(writeset);
1068                 }
1069
1070                 /* Send as much buffered packet data as possible to the sender. */
1071                 if (FD_ISSET(connection_out, writeset))
1072                         packet_write_poll();
1073         }
1074         if (readset)
1075                 xfree(readset);
1076         if (writeset)
1077                 xfree(writeset);
1078
1079         /* Terminate the session. */
1080
1081         /* Stop watching for window change. */
1082         if (have_pty)
1083                 signal(SIGWINCH, SIG_DFL);
1084
1085         channel_free_all();
1086
1087         if (have_pty)
1088                 leave_raw_mode();
1089
1090         /* restore blocking io */
1091         if (!isatty(fileno(stdin)))
1092                 unset_nonblock(fileno(stdin));
1093         if (!isatty(fileno(stdout)))
1094                 unset_nonblock(fileno(stdout));
1095         if (!isatty(fileno(stderr)))
1096                 unset_nonblock(fileno(stderr));
1097
1098         /*
1099          * If there was no shell or command requested, there will be no remote
1100          * exit status to be returned.  In that case, clear error code if the
1101          * connection was deliberately terminated at this end.
1102          */
1103         if (no_shell_flag && received_signal == SIGTERM) {
1104                 received_signal = 0;
1105                 exit_status = 0;
1106         }
1107
1108         if (received_signal)
1109                 fatal("Killed by signal %d.", (int) received_signal);
1110
1111         /*
1112          * In interactive mode (with pseudo tty) display a message indicating
1113          * that the connection has been closed.
1114          */
1115         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1116                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1117                 buffer_append(&stderr_buffer, buf, strlen(buf));
1118         }
1119
1120         /* Output any buffered data for stdout. */
1121         while (buffer_len(&stdout_buffer) > 0) {
1122                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1123                     buffer_len(&stdout_buffer));
1124                 if (len <= 0) {
1125                         error("Write failed flushing stdout buffer.");
1126                         break;
1127                 }
1128                 buffer_consume(&stdout_buffer, len);
1129                 stdout_bytes += len;
1130         }
1131
1132         /* Output any buffered data for stderr. */
1133         while (buffer_len(&stderr_buffer) > 0) {
1134                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1135                     buffer_len(&stderr_buffer));
1136                 if (len <= 0) {
1137                         error("Write failed flushing stderr buffer.");
1138                         break;
1139                 }
1140                 buffer_consume(&stderr_buffer, len);
1141                 stderr_bytes += len;
1142         }
1143
1144         /* Clear and free any buffers. */
1145         memset(buf, 0, sizeof(buf));
1146         buffer_free(&stdin_buffer);
1147         buffer_free(&stdout_buffer);
1148         buffer_free(&stderr_buffer);
1149
1150         /* Report bytes transferred, and transfer rates. */
1151         total_time = get_current_time() - start_time;
1152         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1153             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1154         if (total_time > 0)
1155                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1156                     stdin_bytes / total_time, stdout_bytes / total_time,
1157                     stderr_bytes / total_time);
1158
1159         /* Return the exit status of the program. */
1160         debug("Exit status %d", exit_status);
1161         return exit_status;
1162 }
1163
1164 /*********/
1165
1166 static void
1167 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1168 {
1169         u_int data_len;
1170         char *data = packet_get_string(&data_len);
1171         packet_check_eom();
1172         buffer_append(&stdout_buffer, data, data_len);
1173         memset(data, 0, data_len);
1174         xfree(data);
1175 }
1176 static void
1177 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1178 {
1179         u_int data_len;
1180         char *data = packet_get_string(&data_len);
1181         packet_check_eom();
1182         buffer_append(&stderr_buffer, data, data_len);
1183         memset(data, 0, data_len);
1184         xfree(data);
1185 }
1186 static void
1187 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1188 {
1189         exit_status = packet_get_int();
1190         packet_check_eom();
1191         /* Acknowledge the exit. */
1192         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1193         packet_send();
1194         /*
1195          * Must wait for packet to be sent since we are
1196          * exiting the loop.
1197          */
1198         packet_write_wait();
1199         /* Flag that we want to exit. */
1200         quit_pending = 1;
1201 }
1202 static void
1203 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1204 {
1205         Channel *c = NULL;
1206         int remote_id, sock;
1207
1208         /* Read the remote channel number from the message. */
1209         remote_id = packet_get_int();
1210         packet_check_eom();
1211
1212         /*
1213          * Get a connection to the local authentication agent (this may again
1214          * get forwarded).
1215          */
1216         sock = ssh_get_authentication_socket();
1217
1218         /*
1219          * If we could not connect the agent, send an error message back to
1220          * the server. This should never happen unless the agent dies,
1221          * because authentication forwarding is only enabled if we have an
1222          * agent.
1223          */
1224         if (sock >= 0) {
1225                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1226                     -1, 0, 0, 0, "authentication agent connection", 1);
1227                 c->remote_id = remote_id;
1228                 c->force_drain = 1;
1229         }
1230         if (c == NULL) {
1231                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1232                 packet_put_int(remote_id);
1233         } else {
1234                 /* Send a confirmation to the remote host. */
1235                 debug("Forwarding authentication connection.");
1236                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1237                 packet_put_int(remote_id);
1238                 packet_put_int(c->self);
1239         }
1240         packet_send();
1241 }
1242
1243 static Channel *
1244 client_request_forwarded_tcpip(const char *request_type, int rchan)
1245 {
1246         Channel *c = NULL;
1247         char *listen_address, *originator_address;
1248         int listen_port, originator_port;
1249         int sock;
1250
1251         /* Get rest of the packet */
1252         listen_address = packet_get_string(NULL);
1253         listen_port = packet_get_int();
1254         originator_address = packet_get_string(NULL);
1255         originator_port = packet_get_int();
1256         packet_check_eom();
1257
1258         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1259             listen_address, listen_port, originator_address, originator_port);
1260
1261         sock = channel_connect_by_listen_address(listen_port);
1262         if (sock < 0) {
1263                 xfree(originator_address);
1264                 xfree(listen_address);
1265                 return NULL;
1266         }
1267         c = channel_new("forwarded-tcpip",
1268             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1269             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1270             originator_address, 1);
1271         xfree(originator_address);
1272         xfree(listen_address);
1273         return c;
1274 }
1275
1276 static Channel *
1277 client_request_x11(const char *request_type, int rchan)
1278 {
1279         Channel *c = NULL;
1280         char *originator;
1281         int originator_port;
1282         int sock;
1283
1284         if (!options.forward_x11) {
1285                 error("Warning: ssh server tried X11 forwarding.");
1286                 error("Warning: this is probably a break in attempt by a malicious server.");
1287                 return NULL;
1288         }
1289         originator = packet_get_string(NULL);
1290         if (datafellows & SSH_BUG_X11FWD) {
1291                 debug2("buggy server: x11 request w/o originator_port");
1292                 originator_port = 0;
1293         } else {
1294                 originator_port = packet_get_int();
1295         }
1296         packet_check_eom();
1297         /* XXX check permission */
1298         debug("client_request_x11: request from %s %d", originator,
1299             originator_port);
1300         xfree(originator);
1301         sock = x11_connect_display();
1302         if (sock < 0)
1303                 return NULL;
1304         c = channel_new("x11",
1305             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1306             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1307         c->force_drain = 1;
1308         return c;
1309 }
1310
1311 static Channel *
1312 client_request_agent(const char *request_type, int rchan)
1313 {
1314         Channel *c = NULL;
1315         int sock;
1316
1317         if (!options.forward_agent) {
1318                 error("Warning: ssh server tried agent forwarding.");
1319                 error("Warning: this is probably a break in attempt by a malicious server.");
1320                 return NULL;
1321         }
1322         sock =  ssh_get_authentication_socket();
1323         if (sock < 0)
1324                 return NULL;
1325         c = channel_new("authentication agent connection",
1326             SSH_CHANNEL_OPEN, sock, sock, -1,
1327             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1328             "authentication agent connection", 1);
1329         c->force_drain = 1;
1330         return c;
1331 }
1332
1333 /* XXXX move to generic input handler */
1334 static void
1335 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1336 {
1337         Channel *c = NULL;
1338         char *ctype;
1339         int rchan;
1340         u_int rmaxpack, rwindow, len;
1341
1342         ctype = packet_get_string(&len);
1343         rchan = packet_get_int();
1344         rwindow = packet_get_int();
1345         rmaxpack = packet_get_int();
1346
1347         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1348             ctype, rchan, rwindow, rmaxpack);
1349
1350         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1351                 c = client_request_forwarded_tcpip(ctype, rchan);
1352         } else if (strcmp(ctype, "x11") == 0) {
1353                 c = client_request_x11(ctype, rchan);
1354         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1355                 c = client_request_agent(ctype, rchan);
1356         }
1357 /* XXX duplicate : */
1358         if (c != NULL) {
1359                 debug("confirm %s", ctype);
1360                 c->remote_id = rchan;
1361                 c->remote_window = rwindow;
1362                 c->remote_maxpacket = rmaxpack;
1363                 if (c->type != SSH_CHANNEL_CONNECTING) {
1364                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1365                         packet_put_int(c->remote_id);
1366                         packet_put_int(c->self);
1367                         packet_put_int(c->local_window);
1368                         packet_put_int(c->local_maxpacket);
1369                         packet_send();
1370                 }
1371         } else {
1372                 debug("failure %s", ctype);
1373                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1374                 packet_put_int(rchan);
1375                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1376                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1377                         packet_put_cstring("open failed");
1378                         packet_put_cstring("");
1379                 }
1380                 packet_send();
1381         }
1382         xfree(ctype);
1383 }
1384 static void
1385 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1386 {
1387         Channel *c = NULL;
1388         int id, reply, success = 0;
1389         char *rtype;
1390
1391         id = packet_get_int();
1392         rtype = packet_get_string(NULL);
1393         reply = packet_get_char();
1394
1395         debug("client_input_channel_req: channel %d rtype %s reply %d",
1396             id, rtype, reply);
1397
1398         if (session_ident == -1) {
1399                 error("client_input_channel_req: no channel %d", session_ident);
1400         } else if (id != session_ident) {
1401                 error("client_input_channel_req: channel %d: wrong channel: %d",
1402                     session_ident, id);
1403         }
1404         c = channel_lookup(id);
1405         if (c == NULL) {
1406                 error("client_input_channel_req: channel %d: unknown channel", id);
1407         } else if (strcmp(rtype, "exit-status") == 0) {
1408                 success = 1;
1409                 exit_status = packet_get_int();
1410                 packet_check_eom();
1411         }
1412         if (reply) {
1413                 packet_start(success ?
1414                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1415                 packet_put_int(c->remote_id);
1416                 packet_send();
1417         }
1418         xfree(rtype);
1419 }
1420 static void
1421 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1422 {
1423         char *rtype;
1424         int want_reply;
1425         int success = 0;
1426
1427         rtype = packet_get_string(NULL);
1428         want_reply = packet_get_char();
1429         debug("client_input_global_request: rtype %s want_reply %d",
1430             rtype, want_reply);
1431         if (want_reply) {
1432                 packet_start(success ?
1433                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1434                 packet_send();
1435                 packet_write_wait();
1436         }
1437         xfree(rtype);
1438 }
1439
1440 static void
1441 client_init_dispatch_20(void)
1442 {
1443         dispatch_init(&dispatch_protocol_error);
1444
1445         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1446         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1447         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1448         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1449         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1450         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1451         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1452         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1453         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1454         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1455
1456         /* rekeying */
1457         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1458
1459         /* global request reply messages */
1460         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1461         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1462 }
1463 static void
1464 client_init_dispatch_13(void)
1465 {
1466         dispatch_init(NULL);
1467         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1468         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1469         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1470         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1471         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1472         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1473         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1474         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1475         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1476
1477         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1478             &client_input_agent_open : &deny_input_open);
1479         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1480             &x11_input_open : &deny_input_open);
1481 }
1482 static void
1483 client_init_dispatch_15(void)
1484 {
1485         client_init_dispatch_13();
1486         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1487         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1488 }
1489 static void
1490 client_init_dispatch(void)
1491 {
1492         if (compat20)
1493                 client_init_dispatch_20();
1494         else if (compat13)
1495                 client_init_dispatch_13();
1496         else
1497                 client_init_dispatch_15();
1498 }
1499
1500 /* client specific fatal cleanup */
1501 void
1502 cleanup_exit(int i)
1503 {
1504         leave_raw_mode();
1505         leave_non_blocking();
1506         _exit(i);
1507 }