crypto/openssh-4/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.175 2006/08/03 03:34:42 deraadt Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * The main loop for the interactive session (client side).
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  *
  15  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  *
  38  * SSH2 support added by Markus Friedl.
  39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #include "includes.h"
  63
  64 #include <sys/types.h>
  65 #include <sys/ioctl.h>
  66 #include <sys/param.h>
  67 #ifdef HAVE_SYS_STAT_H
  68 # include <sys/stat.h>
  69 #endif
  70 #ifdef HAVE_SYS_TIME_H
  71 # include <sys/time.h>
  72 #endif
  73 #include <sys/socket.h>
  74
  75 #include <ctype.h>
  76 #include <errno.h>
  77 #ifdef HAVE_PATHS_H
  78 #include <paths.h>
  79 #endif
  80 #include <signal.h>
  81 #include <stdarg.h>
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <string.h>
  85 #include <termios.h>
  86 #include <pwd.h>
  87 #include <unistd.h>
  88
  89 #include "xmalloc.h"
  90 #include "ssh.h"
  91 #include "ssh1.h"
  92 #include "ssh2.h"
  93 #include "packet.h"
  94 #include "buffer.h"
  95 #include "compat.h"
  96 #include "channels.h"
  97 #include "dispatch.h"
  98 #include "key.h"
  99 #include "cipher.h"
 100 #include "kex.h"
 101 #include "log.h"
 102 #include "readconf.h"
 103 #include "clientloop.h"
 104 #include "sshconnect.h"
 105 #include "authfd.h"
 106 #include "atomicio.h"
 107 #include "sshpty.h"
 108 #include "misc.h"
 109 #include "monitor_fdpass.h"
 110 #include "match.h"
 111 #include "msg.h"
 112
 113 /* import options */
 114 extern Options options;
 115
 116 /* Flag indicating that stdin should be redirected from /dev/null. */
 117 extern int stdin_null_flag;
 118
 119 /* Flag indicating that no shell has been requested */
 120 extern int no_shell_flag;
 121
 122 /* Control socket */
 123 extern int control_fd;
 124
 125 /*
 126  * Name of the host we are connecting to.  This is the name given on the
 127  * command line, or the HostName specified for the user-supplied name in a
 128  * configuration file.
 129  */
 130 extern char *host;
 131
 132 /*
 133  * Flag to indicate that we have received a window change signal which has
 134  * not yet been processed.  This will cause a message indicating the new
 135  * window size to be sent to the server a little later.  This is volatile
 136  * because this is updated in a signal handler.
 137  */
 138 static volatile sig_atomic_t received_window_change_signal = 0;
 139 static volatile sig_atomic_t received_signal = 0;
 140
 141 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 142 static int in_non_blocking_mode = 0;
 143
 144 /* Common data for the client loop code. */
 145 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 146 static int escape_char;         /* Escape character. */
 147 static int escape_pending;      /* Last character was the escape character */
 148 static int last_was_cr;         /* Last character was a newline. */
 149 static int exit_status;         /* Used to store the exit status of the command. */
 150 static int stdin_eof;           /* EOF has been encountered on standard error. */
 151 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 152 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 153 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 154 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 155 static u_int buffer_high;/* Soft max buffer size. */
 156 static int connection_in;       /* Connection to server (input). */
 157 static int connection_out;      /* Connection to server (output). */
 158 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 159 static int session_closed = 0;  /* In SSH2: login session closed. */
 160 static int server_alive_timeouts = 0;
 161
 162 static void client_init_dispatch(void);
 163 int     session_ident = -1;
 164
 165 struct confirm_ctx {
 166         int want_tty;
 167         int want_subsys;
 168         int want_x_fwd;
 169         int want_agent_fwd;
 170         Buffer cmd;
 171         char *term;
 172         struct termios tio;
 173         char **env;
 174 };
 175
 176 /*XXX*/
 177 extern Kex *xxx_kex;
 178
 179 void ssh_process_session2_setup(int, int, int, Buffer *);
 180
 181 /* Restores stdin to blocking mode. */
 182
 183 static void
 184 leave_non_blocking(void)
 185 {
 186         if (in_non_blocking_mode) {
 187                 unset_nonblock(fileno(stdin));
 188                 in_non_blocking_mode = 0;
 189         }
 190 }
 191
 192 /* Puts stdin terminal in non-blocking mode. */
 193
 194 static void
 195 enter_non_blocking(void)
 196 {
 197         in_non_blocking_mode = 1;
 198         set_nonblock(fileno(stdin));
 199 }
 200
 201 /*
 202  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 203  * flag indicating that the window has changed.
 204  */
 205 /*ARGSUSED */
 206 static void
 207 window_change_handler(int sig)
 208 {
 209         received_window_change_signal = 1;
 210         signal(SIGWINCH, window_change_handler);
 211 }
 212
 213 /*
 214  * Signal handler for signals that cause the program to terminate.  These
 215  * signals must be trapped to restore terminal modes.
 216  */
 217 /*ARGSUSED */
 218 static void
 219 signal_handler(int sig)
 220 {
 221         received_signal = sig;
 222         quit_pending = 1;
 223 }
 224
 225 /*
 226  * Returns current time in seconds from Jan 1, 1970 with the maximum
 227  * available resolution.
 228  */
 229
 230 static double
 231 get_current_time(void)
 232 {
 233         struct timeval tv;
 234         gettimeofday(&tv, NULL);
 235         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 236 }
 237
 238 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 239 void
 240 client_x11_get_proto(const char *display, const char *xauth_path,
 241     u_int trusted, char **_proto, char **_data)
 242 {
 243         char cmd[1024];
 244         char line[512];
 245         char xdisplay[512];
 246         static char proto[512], data[512];
 247         FILE *f;
 248         int got_data = 0, generated = 0, do_unlink = 0, i;
 249         char *xauthdir, *xauthfile;
 250         struct stat st;
 251
 252         xauthdir = xauthfile = NULL;
 253         *_proto = proto;
 254         *_data = data;
 255         proto[0] = data[0] = '\0';
 256
 257         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 258                 debug("No xauth program.");
 259         } else {
 260                 if (display == NULL) {
 261                         debug("x11_get_proto: DISPLAY not set");
 262                         return;
 263                 }
 264                 /*
 265                  * Handle FamilyLocal case where $DISPLAY does
 266                  * not match an authorization entry.  For this we
 267                  * just try "xauth list unix:displaynum.screennum".
 268                  * XXX: "localhost" match to determine FamilyLocal
 269                  *      is not perfect.
 270                  */
 271                 if (strncmp(display, "localhost:", 10) == 0) {
 272                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 273                             display + 10);
 274                         display = xdisplay;
 275                 }
 276                 if (trusted == 0) {
 277                         xauthdir = xmalloc(MAXPATHLEN);
 278                         xauthfile = xmalloc(MAXPATHLEN);
 279                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 280                         if (mkdtemp(xauthdir) != NULL) {
 281                                 do_unlink = 1;
 282                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 283                                     xauthdir);
 284                                 snprintf(cmd, sizeof(cmd),
 285                                     "%s -f %s generate %s " SSH_X11_PROTO
 286                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 287                                     xauth_path, xauthfile, display);
 288                                 debug2("x11_get_proto: %s", cmd);
 289                                 if (system(cmd) == 0)
 290                                         generated = 1;
 291                         }
 292                 }
 293                 snprintf(cmd, sizeof(cmd),
 294                     "%s %s%s list %s 2>" _PATH_DEVNULL,
 295                     xauth_path,
 296                     generated ? "-f " : "" ,
 297                     generated ? xauthfile : "",
 298                     display);
 299                 debug2("x11_get_proto: %s", cmd);
 300                 f = popen(cmd, "r");
 301                 if (f && fgets(line, sizeof(line), f) &&
 302                     sscanf(line, "%*s %511s %511s", proto, data) == 2)
 303                         got_data = 1;
 304                 if (f)
 305                         pclose(f);
 306         }
 307
 308         if (do_unlink) {
 309                 unlink(xauthfile);
 310                 rmdir(xauthdir);
 311         }
 312         if (xauthdir)
 313                 xfree(xauthdir);
 314         if (xauthfile)
 315                 xfree(xauthfile);
 316
 317         /*
 318          * If we didn't get authentication data, just make up some
 319          * data.  The forwarding code will check the validity of the
 320          * response anyway, and substitute this data.  The X11
 321          * server, however, will ignore this fake data and use
 322          * whatever authentication mechanisms it was using otherwise
 323          * for the local connection.
 324          */
 325         if (!got_data) {
 326                 u_int32_t rnd = 0;
 327
 328                 logit("Warning: No xauth data; "
 329                     "using fake authentication data for X11 forwarding.");
 330                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 331                 for (i = 0; i < 16; i++) {
 332                         if (i % 4 == 0)
 333                                 rnd = arc4random();
 334                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 335                             rnd & 0xff);
 336                         rnd >>= 8;
 337                 }
 338         }
 339 }
 340
 341 /*
 342  * This is called when the interactive is entered.  This checks if there is
 343  * an EOF coming on stdin.  We must check this explicitly, as select() does
 344  * not appear to wake up when redirecting from /dev/null.
 345  */
 346
 347 static void
 348 client_check_initial_eof_on_stdin(void)
 349 {
 350         int len;
 351         char buf[1];
 352
 353         /*
 354          * If standard input is to be "redirected from /dev/null", we simply
 355          * mark that we have seen an EOF and send an EOF message to the
 356          * server. Otherwise, we try to read a single character; it appears
 357          * that for some files, such /dev/null, select() never wakes up for
 358          * read for this descriptor, which means that we never get EOF.  This
 359          * way we will get the EOF if stdin comes from /dev/null or similar.
 360          */
 361         if (stdin_null_flag) {
 362                 /* Fake EOF on stdin. */
 363                 debug("Sending eof.");
 364                 stdin_eof = 1;
 365                 packet_start(SSH_CMSG_EOF);
 366                 packet_send();
 367         } else {
 368                 enter_non_blocking();
 369
 370                 /* Check for immediate EOF on stdin. */
 371                 len = read(fileno(stdin), buf, 1);
 372                 if (len == 0) {
 373                         /* EOF.  Record that we have seen it and send EOF to server. */
 374                         debug("Sending eof.");
 375                         stdin_eof = 1;
 376                         packet_start(SSH_CMSG_EOF);
 377                         packet_send();
 378                 } else if (len > 0) {
 379                         /*
 380                          * Got data.  We must store the data in the buffer,
 381                          * and also process it as an escape character if
 382                          * appropriate.
 383                          */
 384                         if ((u_char) buf[0] == escape_char)
 385                                 escape_pending = 1;
 386                         else
 387                                 buffer_append(&stdin_buffer, buf, 1);
 388                 }
 389                 leave_non_blocking();
 390         }
 391 }
 392
 393
 394 /*
 395  * Make packets from buffered stdin data, and buffer them for sending to the
 396  * connection.
 397  */
 398
 399 static void
 400 client_make_packets_from_stdin_data(void)
 401 {
 402         u_int len;
 403
 404         /* Send buffered stdin data to the server. */
 405         while (buffer_len(&stdin_buffer) > 0 &&
 406             packet_not_very_much_data_to_write()) {
 407                 len = buffer_len(&stdin_buffer);
 408                 /* Keep the packets at reasonable size. */
 409                 if (len > packet_get_maxsize())
 410                         len = packet_get_maxsize();
 411                 packet_start(SSH_CMSG_STDIN_DATA);
 412                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 413                 packet_send();
 414                 buffer_consume(&stdin_buffer, len);
 415                 stdin_bytes += len;
 416                 /* If we have a pending EOF, send it now. */
 417                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 418                         packet_start(SSH_CMSG_EOF);
 419                         packet_send();
 420                 }
 421         }
 422 }
 423
 424 /*
 425  * Checks if the client window has changed, and sends a packet about it to
 426  * the server if so.  The actual change is detected elsewhere (by a software
 427  * interrupt on Unix); this just checks the flag and sends a message if
 428  * appropriate.
 429  */
 430
 431 static void
 432 client_check_window_change(void)
 433 {
 434         struct winsize ws;
 435
 436         if (! received_window_change_signal)
 437                 return;
 438         /** XXX race */
 439         received_window_change_signal = 0;
 440
 441         debug2("client_check_window_change: changed");
 442
 443         if (compat20) {
 444                 channel_send_window_changes();
 445         } else {
 446                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 447                         return;
 448                 packet_start(SSH_CMSG_WINDOW_SIZE);
 449                 packet_put_int((u_int)ws.ws_row);
 450                 packet_put_int((u_int)ws.ws_col);
 451                 packet_put_int((u_int)ws.ws_xpixel);
 452                 packet_put_int((u_int)ws.ws_ypixel);
 453                 packet_send();
 454         }
 455 }
 456
 457 static void
 458 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 459 {
 460         server_alive_timeouts = 0;
 461         client_global_request_reply_fwd(type, seq, ctxt);
 462 }
 463
 464 static void
 465 server_alive_check(void)
 466 {
 467         if (++server_alive_timeouts > options.server_alive_count_max)
 468                 packet_disconnect("Timeout, server not responding.");
 469         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 470         packet_put_cstring("keepalive@openssh.com");
 471         packet_put_char(1);     /* boolean: want reply */
 472         packet_send();
 473 }
 474
 475 /*
 476  * Waits until the client can do something (some data becomes available on
 477  * one of the file descriptors).
 478  */
 479 static void
 480 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 481     int *maxfdp, u_int *nallocp, int rekeying)
 482 {
 483         struct timeval tv, *tvp;
 484         int ret;
 485
 486         /* Add any selections by the channel mechanism. */
 487         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 488
 489         if (!compat20) {
 490                 /* Read from the connection, unless our buffers are full. */
 491                 if (buffer_len(&stdout_buffer) < buffer_high &&
 492                     buffer_len(&stderr_buffer) < buffer_high &&
 493                     channel_not_very_much_buffered_data())
 494                         FD_SET(connection_in, *readsetp);
 495                 /*
 496                  * Read from stdin, unless we have seen EOF or have very much
 497                  * buffered data to send to the server.
 498                  */
 499                 if (!stdin_eof && packet_not_very_much_data_to_write())
 500                         FD_SET(fileno(stdin), *readsetp);
 501
 502                 /* Select stdout/stderr if have data in buffer. */
 503                 if (buffer_len(&stdout_buffer) > 0)
 504                         FD_SET(fileno(stdout), *writesetp);
 505                 if (buffer_len(&stderr_buffer) > 0)
 506                         FD_SET(fileno(stderr), *writesetp);
 507         } else {
 508                 /* channel_prepare_select could have closed the last channel */
 509                 if (session_closed && !channel_still_open() &&
 510                     !packet_have_data_to_write()) {
 511                         /* clear mask since we did not call select() */
 512                         memset(*readsetp, 0, *nallocp);
 513                         memset(*writesetp, 0, *nallocp);
 514                         return;
 515                 } else {
 516                         FD_SET(connection_in, *readsetp);
 517                 }
 518         }
 519
 520         /* Select server connection if have data to write to the server. */
 521         if (packet_have_data_to_write())
 522                 FD_SET(connection_out, *writesetp);
 523
 524         if (control_fd != -1)
 525                 FD_SET(control_fd, *readsetp);
 526
 527         /*
 528          * Wait for something to happen.  This will suspend the process until
 529          * some selected descriptor can be read, written, or has some other
 530          * event pending.
 531          */
 532
 533         if (options.server_alive_interval == 0 || !compat20)
 534                 tvp = NULL;
 535         else {
 536                 tv.tv_sec = options.server_alive_interval;
 537                 tv.tv_usec = 0;
 538                 tvp = &tv;
 539         }
 540         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 541         if (ret < 0) {
 542                 char buf[100];
 543
 544                 /*
 545                  * We have to clear the select masks, because we return.
 546                  * We have to return, because the mainloop checks for the flags
 547                  * set by the signal handlers.
 548                  */
 549                 memset(*readsetp, 0, *nallocp);
 550                 memset(*writesetp, 0, *nallocp);
 551
 552                 if (errno == EINTR)
 553                         return;
 554                 /* Note: we might still have data in the buffers. */
 555                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 556                 buffer_append(&stderr_buffer, buf, strlen(buf));
 557                 quit_pending = 1;
 558         } else if (ret == 0)
 559                 server_alive_check();
 560 }
 561
 562 static void
 563 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 564 {
 565         /* Flush stdout and stderr buffers. */
 566         if (buffer_len(bout) > 0)
 567                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 568         if (buffer_len(berr) > 0)
 569                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 570
 571         leave_raw_mode();
 572
 573         /*
 574          * Free (and clear) the buffer to reduce the amount of data that gets
 575          * written to swap.
 576          */
 577         buffer_free(bin);
 578         buffer_free(bout);
 579         buffer_free(berr);
 580
 581         /* Send the suspend signal to the program itself. */
 582         kill(getpid(), SIGTSTP);
 583
 584         /* Reset window sizes in case they have changed */
 585         received_window_change_signal = 1;
 586
 587         /* OK, we have been continued by the user. Reinitialize buffers. */
 588         buffer_init(bin);
 589         buffer_init(bout);
 590         buffer_init(berr);
 591
 592         enter_raw_mode();
 593 }
 594
 595 static void
 596 client_process_net_input(fd_set *readset)
 597 {
 598         int len;
 599         char buf[8192];
 600
 601         /*
 602          * Read input from the server, and add any such data to the buffer of
 603          * the packet subsystem.
 604          */
 605         if (FD_ISSET(connection_in, readset)) {
 606                 /* Read as much as possible. */
 607                 len = read(connection_in, buf, sizeof(buf));
 608                 if (len == 0) {
 609                         /* Received EOF.  The remote host has closed the connection. */
 610                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 611                                  host);
 612                         buffer_append(&stderr_buffer, buf, strlen(buf));
 613                         quit_pending = 1;
 614                         return;
 615                 }
 616                 /*
 617                  * There is a kernel bug on Solaris that causes select to
 618                  * sometimes wake up even though there is no data available.
 619                  */
 620                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 621                         len = 0;
 622
 623                 if (len < 0) {
 624                         /* An error has encountered.  Perhaps there is a network problem. */
 625                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 626                                  host, strerror(errno));
 627                         buffer_append(&stderr_buffer, buf, strlen(buf));
 628                         quit_pending = 1;
 629                         return;
 630                 }
 631                 packet_process_incoming(buf, len);
 632         }
 633 }
 634
 635 static void
 636 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 637 {
 638         int id;
 639         Channel *c;
 640
 641         id = packet_get_int();
 642         packet_check_eom();
 643
 644         if ((c = channel_lookup(id)) == NULL) {
 645                 error("%s: no channel for id %d", __func__, id);
 646                 return;
 647         }
 648
 649         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 650                 debug2("Request suceeded on channel %d", id);
 651         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 652                 error("Request failed on channel %d", id);
 653                 channel_free(c);
 654         }
 655 }
 656
 657 static void
 658 client_extra_session2_setup(int id, void *arg)
 659 {
 660         struct confirm_ctx *cctx = arg;
 661         const char *display;
 662         Channel *c;
 663         int i;
 664
 665         if (cctx == NULL)
 666                 fatal("%s: cctx == NULL", __func__);
 667         if ((c = channel_lookup(id)) == NULL)
 668                 fatal("%s: no channel for id %d", __func__, id);
 669
 670         display = getenv("DISPLAY");
 671         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 672                 char *proto, *data;
 673                 /* Get reasonable local authentication information. */
 674                 client_x11_get_proto(display, options.xauth_location,
 675                     options.forward_x11_trusted, &proto, &data);
 676                 /* Request forwarding with authentication spoofing. */
 677                 debug("Requesting X11 forwarding with authentication spoofing.");
 678                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 679                 /* XXX wait for reply */
 680         }
 681
 682         if (cctx->want_agent_fwd && options.forward_agent) {
 683                 debug("Requesting authentication agent forwarding.");
 684                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 685                 packet_send();
 686         }
 687
 688         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 689             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 690             client_subsystem_reply);
 691
 692         c->confirm_ctx = NULL;
 693         buffer_free(&cctx->cmd);
 694         xfree(cctx->term);
 695         if (cctx->env != NULL) {
 696                 for (i = 0; cctx->env[i] != NULL; i++)
 697                         xfree(cctx->env[i]);
 698                 xfree(cctx->env);
 699         }
 700         xfree(cctx);
 701 }
 702
 703 static void
 704 client_process_control(fd_set *readset)
 705 {
 706         Buffer m;
 707         Channel *c;
 708         int client_fd, new_fd[3], ver, allowed;
 709         socklen_t addrlen;
 710         struct sockaddr_storage addr;
 711         struct confirm_ctx *cctx;
 712         char *cmd;
 713         u_int i, len, env_len, command, flags;
 714         uid_t euid;
 715         gid_t egid;
 716
 717         /*
 718          * Accept connection on control socket
 719          */
 720         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 721                 return;
 722
 723         memset(&addr, 0, sizeof(addr));
 724         addrlen = sizeof(addr);
 725         if ((client_fd = accept(control_fd,
 726             (struct sockaddr*)&addr, &addrlen)) == -1) {
 727                 error("%s accept: %s", __func__, strerror(errno));
 728                 return;
 729         }
 730
 731         if (getpeereid(client_fd, &euid, &egid) < 0) {
 732                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 733                 close(client_fd);
 734                 return;
 735         }
 736         if ((euid != 0) && (getuid() != euid)) {
 737                 error("control mode uid mismatch: peer euid %u != uid %u",
 738                     (u_int) euid, (u_int) getuid());
 739                 close(client_fd);
 740                 return;
 741         }
 742
 743         unset_nonblock(client_fd);
 744
 745         /* Read command */
 746         buffer_init(&m);
 747         if (ssh_msg_recv(client_fd, &m) == -1) {
 748                 error("%s: client msg_recv failed", __func__);
 749                 close(client_fd);
 750                 buffer_free(&m);
 751                 return;
 752         }
 753         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 754                 error("%s: wrong client version %d", __func__, ver);
 755                 buffer_free(&m);
 756                 close(client_fd);
 757                 return;
 758         }
 759
 760         allowed = 1;
 761         command = buffer_get_int(&m);
 762         flags = buffer_get_int(&m);
 763
 764         buffer_clear(&m);
 765
 766         switch (command) {
 767         case SSHMUX_COMMAND_OPEN:
 768                 if (options.control_master == SSHCTL_MASTER_ASK ||
 769                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 770                         allowed = ask_permission("Allow shared connection "
 771                             "to %s? ", host);
 772                 /* continue below */
 773                 break;
 774         case SSHMUX_COMMAND_TERMINATE:
 775                 if (options.control_master == SSHCTL_MASTER_ASK ||
 776                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 777                         allowed = ask_permission("Terminate shared connection "
 778                             "to %s? ", host);
 779                 if (allowed)
 780                         quit_pending = 1;
 781                 /* FALLTHROUGH */
 782         case SSHMUX_COMMAND_ALIVE_CHECK:
 783                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 784                 buffer_clear(&m);
 785                 buffer_put_int(&m, allowed);
 786                 buffer_put_int(&m, getpid());
 787                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 788                         error("%s: client msg_send failed", __func__);
 789                         close(client_fd);
 790                         buffer_free(&m);
 791                         return;
 792                 }
 793                 buffer_free(&m);
 794                 close(client_fd);
 795                 return;
 796         default:
 797                 error("Unsupported command %d", command);
 798                 buffer_free(&m);
 799                 close(client_fd);
 800                 return;
 801         }
 802
 803         /* Reply for SSHMUX_COMMAND_OPEN */
 804         buffer_clear(&m);
 805         buffer_put_int(&m, allowed);
 806         buffer_put_int(&m, getpid());
 807         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 808                 error("%s: client msg_send failed", __func__);
 809                 close(client_fd);
 810                 buffer_free(&m);
 811                 return;
 812         }
 813
 814         if (!allowed) {
 815                 error("Refused control connection");
 816                 close(client_fd);
 817                 buffer_free(&m);
 818                 return;
 819         }
 820
 821         buffer_clear(&m);
 822         if (ssh_msg_recv(client_fd, &m) == -1) {
 823                 error("%s: client msg_recv failed", __func__);
 824                 close(client_fd);
 825                 buffer_free(&m);
 826                 return;
 827         }
 828         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 829                 error("%s: wrong client version %d", __func__, ver);
 830                 buffer_free(&m);
 831                 close(client_fd);
 832                 return;
 833         }
 834
 835         cctx = xcalloc(1, sizeof(*cctx));
 836         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 837         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 838         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 839         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 840         cctx->term = buffer_get_string(&m, &len);
 841
 842         cmd = buffer_get_string(&m, &len);
 843         buffer_init(&cctx->cmd);
 844         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 845
 846         env_len = buffer_get_int(&m);
 847         env_len = MIN(env_len, 4096);
 848         debug3("%s: receiving %d env vars", __func__, env_len);
 849         if (env_len != 0) {
 850                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 851                 for (i = 0; i < env_len; i++)
 852                         cctx->env[i] = buffer_get_string(&m, &len);
 853                 cctx->env[i] = NULL;
 854         }
 855
 856         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 857             cctx->want_tty, cctx->want_subsys, cmd);
 858         xfree(cmd);
 859
 860         /* Gather fds from client */
 861         new_fd[0] = mm_receive_fd(client_fd);
 862         new_fd[1] = mm_receive_fd(client_fd);
 863         new_fd[2] = mm_receive_fd(client_fd);
 864
 865         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 866             new_fd[0], new_fd[1], new_fd[2]);
 867
 868         /* Try to pick up ttymodes from client before it goes raw */
 869         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 870                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 871
 872         /* This roundtrip is just for synchronisation of ttymodes */
 873         buffer_clear(&m);
 874         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 875                 error("%s: client msg_send failed", __func__);
 876                 close(client_fd);
 877                 close(new_fd[0]);
 878                 close(new_fd[1]);
 879                 close(new_fd[2]);
 880                 buffer_free(&m);
 881                 xfree(cctx->term);
 882                 if (env_len != 0) {
 883                         for (i = 0; i < env_len; i++)
 884                                 xfree(cctx->env[i]);
 885                         xfree(cctx->env);
 886                 }
 887                 return;
 888         }
 889         buffer_free(&m);
 890
 891         /* enable nonblocking unless tty */
 892         if (!isatty(new_fd[0]))
 893                 set_nonblock(new_fd[0]);
 894         if (!isatty(new_fd[1]))
 895                 set_nonblock(new_fd[1]);
 896         if (!isatty(new_fd[2]))
 897                 set_nonblock(new_fd[2]);
 898
 899         set_nonblock(client_fd);
 900
 901         c = channel_new("session", SSH_CHANNEL_OPENING,
 902             new_fd[0], new_fd[1], new_fd[2],
 903             CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
 904             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 905
 906         /* XXX */
 907         c->ctl_fd = client_fd;
 908
 909         debug3("%s: channel_new: %d", __func__, c->self);
 910
 911         channel_send_open(c->self);
 912         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 913 }
 914
 915 static void
 916 process_cmdline(void)
 917 {
 918         void (*handler)(int);
 919         char *s, *cmd, *cancel_host;
 920         int delete = 0;
 921         int local = 0;
 922         u_short cancel_port;
 923         Forward fwd;
 924
 925         leave_raw_mode();
 926         handler = signal(SIGINT, SIG_IGN);
 927         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 928         if (s == NULL)
 929                 goto out;
 930         while (*s && isspace(*s))
 931                 s++;
 932         if (*s == '-')
 933                 s++;    /* Skip cmdline '-', if any */
 934         if (*s == '\0')
 935                 goto out;
 936
 937         if (*s == 'h' || *s == 'H' || *s == '?') {
 938                 logit("Commands:");
 939                 logit("      -L[bind_address:]port:host:hostport    "
 940                     "Request local forward");
 941                 logit("      -R[bind_address:]port:host:hostport    "
 942                     "Request remote forward");
 943                 logit("      -KR[bind_address:]port                 "
 944                     "Cancel remote forward");
 945                 if (!options.permit_local_command)
 946                         goto out;
 947                 logit("      !args                                  "
 948                     "Execute local command");
 949                 goto out;
 950         }
 951
 952         if (*s == '!' && options.permit_local_command) {
 953                 s++;
 954                 ssh_local_cmd(s);
 955                 goto out;
 956         }
 957
 958         if (*s == 'K') {
 959                 delete = 1;
 960                 s++;
 961         }
 962         if (*s != 'L' && *s != 'R') {
 963                 logit("Invalid command.");
 964                 goto out;
 965         }
 966         if (*s == 'L')
 967                 local = 1;
 968         if (local && delete) {
 969                 logit("Not supported.");
 970                 goto out;
 971         }
 972         if ((!local || delete) && !compat20) {
 973                 logit("Not supported for SSH protocol version 1.");
 974                 goto out;
 975         }
 976
 977         s++;
 978         while (*s && isspace(*s))
 979                 s++;
 980
 981         if (delete) {
 982                 cancel_port = 0;
 983                 cancel_host = hpdelim(&s);      /* may be NULL */
 984                 if (s != NULL) {
 985                         cancel_port = a2port(s);
 986                         cancel_host = cleanhostname(cancel_host);
 987                 } else {
 988                         cancel_port = a2port(cancel_host);
 989                         cancel_host = NULL;
 990                 }
 991                 if (cancel_port == 0) {
 992                         logit("Bad forwarding close port");
 993                         goto out;
 994                 }
 995                 channel_request_rforward_cancel(cancel_host, cancel_port);
 996         } else {
 997                 if (!parse_forward(&fwd, s)) {
 998                         logit("Bad forwarding specification.");
 999                         goto out;
1000                 }
1001                 if (local) {
1002                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1003                             fwd.listen_port, fwd.connect_host,
1004                             fwd.connect_port, options.gateway_ports) < 0) {
1005                                 logit("Port forwarding failed.");
1006                                 goto out;
1007                         }
1008                 } else {
1009                         if (channel_request_remote_forwarding(fwd.listen_host,
1010                             fwd.listen_port, fwd.connect_host,
1011                             fwd.connect_port) < 0) {
1012                                 logit("Port forwarding failed.");
1013                                 goto out;
1014                         }
1015                 }
1016
1017                 logit("Forwarding port.");
1018         }
1019
1020 out:
1021         signal(SIGINT, handler);
1022         enter_raw_mode();
1023         if (cmd)
1024                 xfree(cmd);
1025 }
1026
1027 /* process the characters one by one */
1028 static int
1029 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1030 {
1031         char string[1024];
1032         pid_t pid;
1033         int bytes = 0;
1034         u_int i;
1035         u_char ch;
1036         char *s;
1037
1038         if (len <= 0)
1039                 return (0);
1040
1041         for (i = 0; i < (u_int)len; i++) {
1042                 /* Get one character at a time. */
1043                 ch = buf[i];
1044
1045                 if (escape_pending) {
1046                         /* We have previously seen an escape character. */
1047                         /* Clear the flag now. */
1048                         escape_pending = 0;
1049
1050                         /* Process the escaped character. */
1051                         switch (ch) {
1052                         case '.':
1053                                 /* Terminate the connection. */
1054                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1055                                 buffer_append(berr, string, strlen(string));
1056
1057                                 quit_pending = 1;
1058                                 return -1;
1059
1060                         case 'Z' - 64:
1061                                 /* Suspend the program. */
1062                                 /* Print a message to that effect to the user. */
1063                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1064                                 buffer_append(berr, string, strlen(string));
1065
1066                                 /* Restore terminal modes and suspend. */
1067                                 client_suspend_self(bin, bout, berr);
1068
1069                                 /* We have been continued. */
1070                                 continue;
1071
1072                         case 'B':
1073                                 if (compat20) {
1074                                         snprintf(string, sizeof string,
1075                                             "%cB\r\n", escape_char);
1076                                         buffer_append(berr, string,
1077                                             strlen(string));
1078                                         channel_request_start(session_ident,
1079                                             "break", 0);
1080                                         packet_put_int(1000);
1081                                         packet_send();
1082                                 }
1083                                 continue;
1084
1085                         case 'R':
1086                                 if (compat20) {
1087                                         if (datafellows & SSH_BUG_NOREKEY)
1088                                                 logit("Server does not support re-keying");
1089                                         else
1090                                                 need_rekeying = 1;
1091                                 }
1092                                 continue;
1093
1094                         case '&':
1095                                 /*
1096                                  * Detach the program (continue to serve connections,
1097                                  * but put in background and no more new connections).
1098                                  */
1099                                 /* Restore tty modes. */
1100                                 leave_raw_mode();
1101
1102                                 /* Stop listening for new connections. */
1103                                 channel_stop_listening();
1104
1105                                 snprintf(string, sizeof string,
1106                                     "%c& [backgrounded]\n", escape_char);
1107                                 buffer_append(berr, string, strlen(string));
1108
1109                                 /* Fork into background. */
1110                                 pid = fork();
1111                                 if (pid < 0) {
1112                                         error("fork: %.100s", strerror(errno));
1113                                         continue;
1114                                 }
1115                                 if (pid != 0) { /* This is the parent. */
1116                                         /* The parent just exits. */
1117                                         exit(0);
1118                                 }
1119                                 /* The child continues serving connections. */
1120                                 if (compat20) {
1121                                         buffer_append(bin, "\004", 1);
1122                                         /* fake EOF on stdin */
1123                                         return -1;
1124                                 } else if (!stdin_eof) {
1125                                         /*
1126                                          * Sending SSH_CMSG_EOF alone does not always appear
1127                                          * to be enough.  So we try to send an EOF character
1128                                          * first.
1129                                          */
1130                                         packet_start(SSH_CMSG_STDIN_DATA);
1131                                         packet_put_string("\004", 1);
1132                                         packet_send();
1133                                         /* Close stdin. */
1134                                         stdin_eof = 1;
1135                                         if (buffer_len(bin) == 0) {
1136                                                 packet_start(SSH_CMSG_EOF);
1137                                                 packet_send();
1138                                         }
1139                                 }
1140                                 continue;
1141
1142                         case '?':
1143                                 snprintf(string, sizeof string,
1144 "%c?\r\n\
1145 Supported escape sequences:\r\n\
1146 %c.  - terminate connection\r\n\
1147 %cB  - send a BREAK to the remote system\r\n\
1148 %cC  - open a command line\r\n\
1149 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1150 %c^Z - suspend ssh\r\n\
1151 %c#  - list forwarded connections\r\n\
1152 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1153 %c?  - this message\r\n\
1154 %c%c  - send the escape character by typing it twice\r\n\
1155 (Note that escapes are only recognized immediately after newline.)\r\n",
1156                                     escape_char, escape_char, escape_char, escape_char,
1157                                     escape_char, escape_char, escape_char, escape_char,
1158                                     escape_char, escape_char, escape_char);
1159                                 buffer_append(berr, string, strlen(string));
1160                                 continue;
1161
1162                         case '#':
1163                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1164                                 buffer_append(berr, string, strlen(string));
1165                                 s = channel_open_message();
1166                                 buffer_append(berr, s, strlen(s));
1167                                 xfree(s);
1168                                 continue;
1169
1170                         case 'C':
1171                                 process_cmdline();
1172                                 continue;
1173
1174                         default:
1175                                 if (ch != escape_char) {
1176                                         buffer_put_char(bin, escape_char);
1177                                         bytes++;
1178                                 }
1179                                 /* Escaped characters fall through here */
1180                                 break;
1181                         }
1182                 } else {
1183                         /*
1184                          * The previous character was not an escape char. Check if this
1185                          * is an escape.
1186                          */
1187                         if (last_was_cr && ch == escape_char) {
1188                                 /* It is. Set the flag and continue to next character. */
1189                                 escape_pending = 1;
1190                                 continue;
1191                         }
1192                 }
1193
1194                 /*
1195                  * Normal character.  Record whether it was a newline,
1196                  * and append it to the buffer.
1197                  */
1198                 last_was_cr = (ch == '\r' || ch == '\n');
1199                 buffer_put_char(bin, ch);
1200                 bytes++;
1201         }
1202         return bytes;
1203 }
1204
1205 static void
1206 client_process_input(fd_set *readset)
1207 {
1208         int len;
1209         char buf[8192];
1210
1211         /* Read input from stdin. */
1212         if (FD_ISSET(fileno(stdin), readset)) {
1213                 /* Read as much as possible. */
1214                 len = read(fileno(stdin), buf, sizeof(buf));
1215                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1216                         return;         /* we'll try again later */
1217                 if (len <= 0) {
1218                         /*
1219                          * Received EOF or error.  They are treated
1220                          * similarly, except that an error message is printed
1221                          * if it was an error condition.
1222                          */
1223                         if (len < 0) {
1224                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1225                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1226                         }
1227                         /* Mark that we have seen EOF. */
1228                         stdin_eof = 1;
1229                         /*
1230                          * Send an EOF message to the server unless there is
1231                          * data in the buffer.  If there is data in the
1232                          * buffer, no message will be sent now.  Code
1233                          * elsewhere will send the EOF when the buffer
1234                          * becomes empty if stdin_eof is set.
1235                          */
1236                         if (buffer_len(&stdin_buffer) == 0) {
1237                                 packet_start(SSH_CMSG_EOF);
1238                                 packet_send();
1239                         }
1240                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1241                         /*
1242                          * Normal successful read, and no escape character.
1243                          * Just append the data to buffer.
1244                          */
1245                         buffer_append(&stdin_buffer, buf, len);
1246                 } else {
1247                         /*
1248                          * Normal, successful read.  But we have an escape character
1249                          * and have to process the characters one by one.
1250                          */
1251                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1252                             &stderr_buffer, buf, len) == -1)
1253                                 return;
1254                 }
1255         }
1256 }
1257
1258 static void
1259 client_process_output(fd_set *writeset)
1260 {
1261         int len;
1262         char buf[100];
1263
1264         /* Write buffered output to stdout. */
1265         if (FD_ISSET(fileno(stdout), writeset)) {
1266                 /* Write as much data as possible. */
1267                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1268                     buffer_len(&stdout_buffer));
1269                 if (len <= 0) {
1270                         if (errno == EINTR || errno == EAGAIN)
1271                                 len = 0;
1272                         else {
1273                                 /*
1274                                  * An error or EOF was encountered.  Put an
1275                                  * error message to stderr buffer.
1276                                  */
1277                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1278                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1279                                 quit_pending = 1;
1280                                 return;
1281                         }
1282                 }
1283                 /* Consume printed data from the buffer. */
1284                 buffer_consume(&stdout_buffer, len);
1285                 stdout_bytes += len;
1286         }
1287         /* Write buffered output to stderr. */
1288         if (FD_ISSET(fileno(stderr), writeset)) {
1289                 /* Write as much data as possible. */
1290                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1291                     buffer_len(&stderr_buffer));
1292                 if (len <= 0) {
1293                         if (errno == EINTR || errno == EAGAIN)
1294                                 len = 0;
1295                         else {
1296                                 /* EOF or error, but can't even print error message. */
1297                                 quit_pending = 1;
1298                                 return;
1299                         }
1300                 }
1301                 /* Consume printed characters from the buffer. */
1302                 buffer_consume(&stderr_buffer, len);
1303                 stderr_bytes += len;
1304         }
1305 }
1306
1307 /*
1308  * Get packets from the connection input buffer, and process them as long as
1309  * there are packets available.
1310  *
1311  * Any unknown packets received during the actual
1312  * session cause the session to terminate.  This is
1313  * intended to make debugging easier since no
1314  * confirmations are sent.  Any compatible protocol
1315  * extensions must be negotiated during the
1316  * preparatory phase.
1317  */
1318
1319 static void
1320 client_process_buffered_input_packets(void)
1321 {
1322         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1323 }
1324
1325 /* scan buf[] for '~' before sending data to the peer */
1326
1327 static int
1328 simple_escape_filter(Channel *c, char *buf, int len)
1329 {
1330         /* XXX we assume c->extended is writeable */
1331         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1332 }
1333
1334 static void
1335 client_channel_closed(int id, void *arg)
1336 {
1337         channel_cancel_cleanup(id);
1338         session_closed = 1;
1339         leave_raw_mode();
1340 }
1341
1342 /*
1343  * Implements the interactive session with the server.  This is called after
1344  * the user has been authenticated, and a command has been started on the
1345  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1346  * used as an escape character for terminating or suspending the session.
1347  */
1348
1349 int
1350 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1351 {
1352         fd_set *readset = NULL, *writeset = NULL;
1353         double start_time, total_time;
1354         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1355         u_int nalloc = 0;
1356         char buf[100];
1357
1358         debug("Entering interactive session.");
1359
1360         start_time = get_current_time();
1361
1362         /* Initialize variables. */
1363         escape_pending = 0;
1364         last_was_cr = 1;
1365         exit_status = -1;
1366         stdin_eof = 0;
1367         buffer_high = 64 * 1024;
1368         connection_in = packet_get_connection_in();
1369         connection_out = packet_get_connection_out();
1370         max_fd = MAX(connection_in, connection_out);
1371         if (control_fd != -1)
1372                 max_fd = MAX(max_fd, control_fd);
1373
1374         if (!compat20) {
1375                 /* enable nonblocking unless tty */
1376                 if (!isatty(fileno(stdin)))
1377                         set_nonblock(fileno(stdin));
1378                 if (!isatty(fileno(stdout)))
1379                         set_nonblock(fileno(stdout));
1380                 if (!isatty(fileno(stderr)))
1381                         set_nonblock(fileno(stderr));
1382                 max_fd = MAX(max_fd, fileno(stdin));
1383                 max_fd = MAX(max_fd, fileno(stdout));
1384                 max_fd = MAX(max_fd, fileno(stderr));
1385         }
1386         stdin_bytes = 0;
1387         stdout_bytes = 0;
1388         stderr_bytes = 0;
1389         quit_pending = 0;
1390         escape_char = escape_char_arg;
1391
1392         /* Initialize buffers. */
1393         buffer_init(&stdin_buffer);
1394         buffer_init(&stdout_buffer);
1395         buffer_init(&stderr_buffer);
1396
1397         client_init_dispatch();
1398
1399         /*
1400          * Set signal handlers, (e.g. to restore non-blocking mode)
1401          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1402          */
1403         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1404                 signal(SIGHUP, signal_handler);
1405         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1406                 signal(SIGINT, signal_handler);
1407         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1408                 signal(SIGQUIT, signal_handler);
1409         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1410                 signal(SIGTERM, signal_handler);
1411         signal(SIGWINCH, window_change_handler);
1412
1413         if (have_pty)
1414                 enter_raw_mode();
1415
1416         if (compat20) {
1417                 session_ident = ssh2_chan_id;
1418                 if (escape_char != SSH_ESCAPECHAR_NONE)
1419                         channel_register_filter(session_ident,
1420                             simple_escape_filter, NULL);
1421                 if (session_ident != -1)
1422                         channel_register_cleanup(session_ident,
1423                             client_channel_closed, 0);
1424         } else {
1425                 /* Check if we should immediately send eof on stdin. */
1426                 client_check_initial_eof_on_stdin();
1427         }
1428
1429         /* Main loop of the client for the interactive session mode. */
1430         while (!quit_pending) {
1431
1432                 /* Process buffered packets sent by the server. */
1433                 client_process_buffered_input_packets();
1434
1435                 if (compat20 && session_closed && !channel_still_open())
1436                         break;
1437
1438                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1439
1440                 if (rekeying) {
1441                         debug("rekeying in progress");
1442                 } else {
1443                         /*
1444                          * Make packets of buffered stdin data, and buffer
1445                          * them for sending to the server.
1446                          */
1447                         if (!compat20)
1448                                 client_make_packets_from_stdin_data();
1449
1450                         /*
1451                          * Make packets from buffered channel data, and
1452                          * enqueue them for sending to the server.
1453                          */
1454                         if (packet_not_very_much_data_to_write())
1455                                 channel_output_poll();
1456
1457                         /*
1458                          * Check if the window size has changed, and buffer a
1459                          * message about it to the server if so.
1460                          */
1461                         client_check_window_change();
1462
1463                         if (quit_pending)
1464                                 break;
1465                 }
1466                 /*
1467                  * Wait until we have something to do (something becomes
1468                  * available on one of the descriptors).
1469                  */
1470                 max_fd2 = max_fd;
1471                 client_wait_until_can_do_something(&readset, &writeset,
1472                     &max_fd2, &nalloc, rekeying);
1473
1474                 if (quit_pending)
1475                         break;
1476
1477                 /* Do channel operations unless rekeying in progress. */
1478                 if (!rekeying) {
1479                         channel_after_select(readset, writeset);
1480                         if (need_rekeying || packet_need_rekeying()) {
1481                                 debug("need rekeying");
1482                                 xxx_kex->done = 0;
1483                                 kex_send_kexinit(xxx_kex);
1484                                 need_rekeying = 0;
1485                         }
1486                 }
1487
1488                 /* Buffer input from the connection.  */
1489                 client_process_net_input(readset);
1490
1491                 /* Accept control connections.  */
1492                 client_process_control(readset);
1493
1494                 if (quit_pending)
1495                         break;
1496
1497                 if (!compat20) {
1498                         /* Buffer data from stdin */
1499                         client_process_input(readset);
1500                         /*
1501                          * Process output to stdout and stderr.  Output to
1502                          * the connection is processed elsewhere (above).
1503                          */
1504                         client_process_output(writeset);
1505                 }
1506
1507                 /* Send as much buffered packet data as possible to the sender. */
1508                 if (FD_ISSET(connection_out, writeset))
1509                         packet_write_poll();
1510         }
1511         if (readset)
1512                 xfree(readset);
1513         if (writeset)
1514                 xfree(writeset);
1515
1516         /* Terminate the session. */
1517
1518         /* Stop watching for window change. */
1519         signal(SIGWINCH, SIG_DFL);
1520
1521         channel_free_all();
1522
1523         if (have_pty)
1524                 leave_raw_mode();
1525
1526         /* restore blocking io */
1527         if (!isatty(fileno(stdin)))
1528                 unset_nonblock(fileno(stdin));
1529         if (!isatty(fileno(stdout)))
1530                 unset_nonblock(fileno(stdout));
1531         if (!isatty(fileno(stderr)))
1532                 unset_nonblock(fileno(stderr));
1533
1534         /*
1535          * If there was no shell or command requested, there will be no remote
1536          * exit status to be returned.  In that case, clear error code if the
1537          * connection was deliberately terminated at this end.
1538          */
1539         if (no_shell_flag && received_signal == SIGTERM) {
1540                 received_signal = 0;
1541                 exit_status = 0;
1542         }
1543
1544         if (received_signal)
1545                 fatal("Killed by signal %d.", (int) received_signal);
1546
1547         /*
1548          * In interactive mode (with pseudo tty) display a message indicating
1549          * that the connection has been closed.
1550          */
1551         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1552                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1553                 buffer_append(&stderr_buffer, buf, strlen(buf));
1554         }
1555
1556         /* Output any buffered data for stdout. */
1557         while (buffer_len(&stdout_buffer) > 0) {
1558                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1559                     buffer_len(&stdout_buffer));
1560                 if (len <= 0) {
1561                         error("Write failed flushing stdout buffer.");
1562                         break;
1563                 }
1564                 buffer_consume(&stdout_buffer, len);
1565                 stdout_bytes += len;
1566         }
1567
1568         /* Output any buffered data for stderr. */
1569         while (buffer_len(&stderr_buffer) > 0) {
1570                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1571                     buffer_len(&stderr_buffer));
1572                 if (len <= 0) {
1573                         error("Write failed flushing stderr buffer.");
1574                         break;
1575                 }
1576                 buffer_consume(&stderr_buffer, len);
1577                 stderr_bytes += len;
1578         }
1579
1580         /* Clear and free any buffers. */
1581         memset(buf, 0, sizeof(buf));
1582         buffer_free(&stdin_buffer);
1583         buffer_free(&stdout_buffer);
1584         buffer_free(&stderr_buffer);
1585
1586         /* Report bytes transferred, and transfer rates. */
1587         total_time = get_current_time() - start_time;
1588         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1589             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1590         if (total_time > 0)
1591                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1592                     stdin_bytes / total_time, stdout_bytes / total_time,
1593                     stderr_bytes / total_time);
1594
1595         /* Return the exit status of the program. */
1596         debug("Exit status %d", exit_status);
1597         return exit_status;
1598 }
1599
1600 /*********/
1601
1602 static void
1603 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1604 {
1605         u_int data_len;
1606         char *data = packet_get_string(&data_len);
1607         packet_check_eom();
1608         buffer_append(&stdout_buffer, data, data_len);
1609         memset(data, 0, data_len);
1610         xfree(data);
1611 }
1612 static void
1613 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1614 {
1615         u_int data_len;
1616         char *data = packet_get_string(&data_len);
1617         packet_check_eom();
1618         buffer_append(&stderr_buffer, data, data_len);
1619         memset(data, 0, data_len);
1620         xfree(data);
1621 }
1622 static void
1623 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1624 {
1625         exit_status = packet_get_int();
1626         packet_check_eom();
1627         /* Acknowledge the exit. */
1628         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1629         packet_send();
1630         /*
1631          * Must wait for packet to be sent since we are
1632          * exiting the loop.
1633          */
1634         packet_write_wait();
1635         /* Flag that we want to exit. */
1636         quit_pending = 1;
1637 }
1638 static void
1639 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1640 {
1641         Channel *c = NULL;
1642         int remote_id, sock;
1643
1644         /* Read the remote channel number from the message. */
1645         remote_id = packet_get_int();
1646         packet_check_eom();
1647
1648         /*
1649          * Get a connection to the local authentication agent (this may again
1650          * get forwarded).
1651          */
1652         sock = ssh_get_authentication_socket();
1653
1654         /*
1655          * If we could not connect the agent, send an error message back to
1656          * the server. This should never happen unless the agent dies,
1657          * because authentication forwarding is only enabled if we have an
1658          * agent.
1659          */
1660         if (sock >= 0) {
1661                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1662                     -1, 0, 0, 0, "authentication agent connection", 1);
1663                 c->remote_id = remote_id;
1664                 c->force_drain = 1;
1665         }
1666         if (c == NULL) {
1667                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1668                 packet_put_int(remote_id);
1669         } else {
1670                 /* Send a confirmation to the remote host. */
1671                 debug("Forwarding authentication connection.");
1672                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1673                 packet_put_int(remote_id);
1674                 packet_put_int(c->self);
1675         }
1676         packet_send();
1677 }
1678
1679 static Channel *
1680 client_request_forwarded_tcpip(const char *request_type, int rchan)
1681 {
1682         Channel *c = NULL;
1683         char *listen_address, *originator_address;
1684         int listen_port, originator_port;
1685         int sock;
1686
1687         /* Get rest of the packet */
1688         listen_address = packet_get_string(NULL);
1689         listen_port = packet_get_int();
1690         originator_address = packet_get_string(NULL);
1691         originator_port = packet_get_int();
1692         packet_check_eom();
1693
1694         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1695             listen_address, listen_port, originator_address, originator_port);
1696
1697         sock = channel_connect_by_listen_address(listen_port);
1698         if (sock < 0) {
1699                 xfree(originator_address);
1700                 xfree(listen_address);
1701                 return NULL;
1702         }
1703         c = channel_new("forwarded-tcpip",
1704             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1705             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1706             originator_address, 1);
1707         xfree(originator_address);
1708         xfree(listen_address);
1709         return c;
1710 }
1711
1712 static Channel *
1713 client_request_x11(const char *request_type, int rchan)
1714 {
1715         Channel *c = NULL;
1716         char *originator;
1717         int originator_port;
1718         int sock;
1719
1720         if (!options.forward_x11) {
1721                 error("Warning: ssh server tried X11 forwarding.");
1722                 error("Warning: this is probably a break-in attempt by a malicious server.");
1723                 return NULL;
1724         }
1725         originator = packet_get_string(NULL);
1726         if (datafellows & SSH_BUG_X11FWD) {
1727                 debug2("buggy server: x11 request w/o originator_port");
1728                 originator_port = 0;
1729         } else {
1730                 originator_port = packet_get_int();
1731         }
1732         packet_check_eom();
1733         /* XXX check permission */
1734         debug("client_request_x11: request from %s %d", originator,
1735             originator_port);
1736         xfree(originator);
1737         sock = x11_connect_display();
1738         if (sock < 0)
1739                 return NULL;
1740         c = channel_new("x11",
1741             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1742             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1743         c->force_drain = 1;
1744         return c;
1745 }
1746
1747 static Channel *
1748 client_request_agent(const char *request_type, int rchan)
1749 {
1750         Channel *c = NULL;
1751         int sock;
1752
1753         if (!options.forward_agent) {
1754                 error("Warning: ssh server tried agent forwarding.");
1755                 error("Warning: this is probably a break-in attempt by a malicious server.");
1756                 return NULL;
1757         }
1758         sock =  ssh_get_authentication_socket();
1759         if (sock < 0)
1760                 return NULL;
1761         c = channel_new("authentication agent connection",
1762             SSH_CHANNEL_OPEN, sock, sock, -1,
1763             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1764             "authentication agent connection", 1);
1765         c->force_drain = 1;
1766         return c;
1767 }
1768
1769 /* XXXX move to generic input handler */
1770 static void
1771 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1772 {
1773         Channel *c = NULL;
1774         char *ctype;
1775         int rchan;
1776         u_int rmaxpack, rwindow, len;
1777
1778         ctype = packet_get_string(&len);
1779         rchan = packet_get_int();
1780         rwindow = packet_get_int();
1781         rmaxpack = packet_get_int();
1782
1783         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1784             ctype, rchan, rwindow, rmaxpack);
1785
1786         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1787                 c = client_request_forwarded_tcpip(ctype, rchan);
1788         } else if (strcmp(ctype, "x11") == 0) {
1789                 c = client_request_x11(ctype, rchan);
1790         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1791                 c = client_request_agent(ctype, rchan);
1792         }
1793 /* XXX duplicate : */
1794         if (c != NULL) {
1795                 debug("confirm %s", ctype);
1796                 c->remote_id = rchan;
1797                 c->remote_window = rwindow;
1798                 c->remote_maxpacket = rmaxpack;
1799                 if (c->type != SSH_CHANNEL_CONNECTING) {
1800                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1801                         packet_put_int(c->remote_id);
1802                         packet_put_int(c->self);
1803                         packet_put_int(c->local_window);
1804                         packet_put_int(c->local_maxpacket);
1805                         packet_send();
1806                 }
1807         } else {
1808                 debug("failure %s", ctype);
1809                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1810                 packet_put_int(rchan);
1811                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1812                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1813                         packet_put_cstring("open failed");
1814                         packet_put_cstring("");
1815                 }
1816                 packet_send();
1817         }
1818         xfree(ctype);
1819 }
1820 static void
1821 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1822 {
1823         Channel *c = NULL;
1824         int exitval, id, reply, success = 0;
1825         char *rtype;
1826
1827         id = packet_get_int();
1828         rtype = packet_get_string(NULL);
1829         reply = packet_get_char();
1830
1831         debug("client_input_channel_req: channel %d rtype %s reply %d",
1832             id, rtype, reply);
1833
1834         if (id == -1) {
1835                 error("client_input_channel_req: request for channel -1");
1836         } else if ((c = channel_lookup(id)) == NULL) {
1837                 error("client_input_channel_req: channel %d: unknown channel", id);
1838         } else if (strcmp(rtype, "exit-status") == 0) {
1839                 exitval = packet_get_int();
1840                 if (id == session_ident) {
1841                         success = 1;
1842                         exit_status = exitval;
1843                 } else if (c->ctl_fd == -1) {
1844                         error("client_input_channel_req: unexpected channel %d",
1845                             session_ident);
1846                 } else {
1847                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1848                         success = 1;
1849                 }
1850                 packet_check_eom();
1851         }
1852         if (reply) {
1853                 packet_start(success ?
1854                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1855                 packet_put_int(id);
1856                 packet_send();
1857         }
1858         xfree(rtype);
1859 }
1860 static void
1861 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1862 {
1863         char *rtype;
1864         int want_reply;
1865         int success = 0;
1866
1867         rtype = packet_get_string(NULL);
1868         want_reply = packet_get_char();
1869         debug("client_input_global_request: rtype %s want_reply %d",
1870             rtype, want_reply);
1871         if (want_reply) {
1872                 packet_start(success ?
1873                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1874                 packet_send();
1875                 packet_write_wait();
1876         }
1877         xfree(rtype);
1878 }
1879
1880 void
1881 client_session2_setup(int id, int want_tty, int want_subsystem,
1882     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1883     dispatch_fn *subsys_repl)
1884 {
1885         int len;
1886         Channel *c = NULL;
1887
1888         debug2("%s: id %d", __func__, id);
1889
1890         if ((c = channel_lookup(id)) == NULL)
1891                 fatal("client_session2_setup: channel %d: unknown channel", id);
1892
1893         if (want_tty) {
1894                 struct winsize ws;
1895                 struct termios tio;
1896
1897                 /* Store window size in the packet. */
1898                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1899                         memset(&ws, 0, sizeof(ws));
1900
1901                 channel_request_start(id, "pty-req", 0);
1902                 packet_put_cstring(term != NULL ? term : "");
1903                 packet_put_int((u_int)ws.ws_col);
1904                 packet_put_int((u_int)ws.ws_row);
1905                 packet_put_int((u_int)ws.ws_xpixel);
1906                 packet_put_int((u_int)ws.ws_ypixel);
1907                 tio = get_saved_tio();
1908                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1909                 packet_send();
1910                 /* XXX wait for reply */
1911                 c->client_tty = 1;
1912         }
1913
1914         /* Transfer any environment variables from client to server */
1915         if (options.num_send_env != 0 && env != NULL) {
1916                 int i, j, matched;
1917                 char *name, *val;
1918
1919                 debug("Sending environment.");
1920                 for (i = 0; env[i] != NULL; i++) {
1921                         /* Split */
1922                         name = xstrdup(env[i]);
1923                         if ((val = strchr(name, '=')) == NULL) {
1924                                 xfree(name);
1925                                 continue;
1926                         }
1927                         *val++ = '\0';
1928
1929                         matched = 0;
1930                         for (j = 0; j < options.num_send_env; j++) {
1931                                 if (match_pattern(name, options.send_env[j])) {
1932                                         matched = 1;
1933                                         break;
1934                                 }
1935                         }
1936                         if (!matched) {
1937                                 debug3("Ignored env %s", name);
1938                                 xfree(name);
1939                                 continue;
1940                         }
1941
1942                         debug("Sending env %s = %s", name, val);
1943                         channel_request_start(id, "env", 0);
1944                         packet_put_cstring(name);
1945                         packet_put_cstring(val);
1946                         packet_send();
1947                         xfree(name);
1948                 }
1949         }
1950
1951         len = buffer_len(cmd);
1952         if (len > 0) {
1953                 if (len > 900)
1954                         len = 900;
1955                 if (want_subsystem) {
1956                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
1957                         channel_request_start(id, "subsystem", subsys_repl != NULL);
1958                         if (subsys_repl != NULL) {
1959                                 /* register callback for reply */
1960                                 /* XXX we assume that client_loop has already been called */
1961                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
1962                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
1963                         }
1964                 } else {
1965                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
1966                         channel_request_start(id, "exec", 0);
1967                 }
1968                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
1969                 packet_send();
1970         } else {
1971                 channel_request_start(id, "shell", 0);
1972                 packet_send();
1973         }
1974 }
1975
1976 static void
1977 client_init_dispatch_20(void)
1978 {
1979         dispatch_init(&dispatch_protocol_error);
1980
1981         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1982         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1983         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1984         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1985         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1986         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1987         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1988         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1989         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1990         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1991
1992         /* rekeying */
1993         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1994
1995         /* global request reply messages */
1996         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1997         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1998 }
1999 static void
2000 client_init_dispatch_13(void)
2001 {
2002         dispatch_init(NULL);
2003         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2004         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2005         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2006         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2007         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2008         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2009         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2010         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2011         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2012
2013         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2014             &client_input_agent_open : &deny_input_open);
2015         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2016             &x11_input_open : &deny_input_open);
2017 }
2018 static void
2019 client_init_dispatch_15(void)
2020 {
2021         client_init_dispatch_13();
2022         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2023         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2024 }
2025 static void
2026 client_init_dispatch(void)
2027 {
2028         if (compat20)
2029                 client_init_dispatch_20();
2030         else if (compat13)
2031                 client_init_dispatch_13();
2032         else
2033                 client_init_dispatch_15();
2034 }
2035
2036 /* client specific fatal cleanup */
2037 void
2038 cleanup_exit(int i)
2039 {
2040         leave_raw_mode();
2041         leave_non_blocking();
2042         if (options.control_path != NULL && control_fd != -1)
2043                 unlink(options.control_path);
2044         _exit(i);
2045 }