clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.180 2007/08/07 07:32:53 djm 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                 logit("Timeout, server not responding.");
 469                 cleanup_exit(255);
 470         }
 471         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 472         packet_put_cstring("keepalive@openssh.com");
 473         packet_put_char(1);     /* boolean: want reply */
 474         packet_send();
 475 }
 476
 477 /*
 478  * Waits until the client can do something (some data becomes available on
 479  * one of the file descriptors).
 480  */
 481 static void
 482 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 483     int *maxfdp, u_int *nallocp, int rekeying)
 484 {
 485         struct timeval tv, *tvp;
 486         int ret;
 487
 488         /* Add any selections by the channel mechanism. */
 489         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 490
 491         if (!compat20) {
 492                 /* Read from the connection, unless our buffers are full. */
 493                 if (buffer_len(&stdout_buffer) < buffer_high &&
 494                     buffer_len(&stderr_buffer) < buffer_high &&
 495                     channel_not_very_much_buffered_data())
 496                         FD_SET(connection_in, *readsetp);
 497                 /*
 498                  * Read from stdin, unless we have seen EOF or have very much
 499                  * buffered data to send to the server.
 500                  */
 501                 if (!stdin_eof && packet_not_very_much_data_to_write())
 502                         FD_SET(fileno(stdin), *readsetp);
 503
 504                 /* Select stdout/stderr if have data in buffer. */
 505                 if (buffer_len(&stdout_buffer) > 0)
 506                         FD_SET(fileno(stdout), *writesetp);
 507                 if (buffer_len(&stderr_buffer) > 0)
 508                         FD_SET(fileno(stderr), *writesetp);
 509         } else {
 510                 /* channel_prepare_select could have closed the last channel */
 511                 if (session_closed && !channel_still_open() &&
 512                     !packet_have_data_to_write()) {
 513                         /* clear mask since we did not call select() */
 514                         memset(*readsetp, 0, *nallocp);
 515                         memset(*writesetp, 0, *nallocp);
 516                         return;
 517                 } else {
 518                         FD_SET(connection_in, *readsetp);
 519                 }
 520         }
 521
 522         /* Select server connection if have data to write to the server. */
 523         if (packet_have_data_to_write())
 524                 FD_SET(connection_out, *writesetp);
 525
 526         if (control_fd != -1)
 527                 FD_SET(control_fd, *readsetp);
 528
 529         /*
 530          * Wait for something to happen.  This will suspend the process until
 531          * some selected descriptor can be read, written, or has some other
 532          * event pending.
 533          */
 534
 535         if (options.server_alive_interval == 0 || !compat20)
 536                 tvp = NULL;
 537         else {
 538                 tv.tv_sec = options.server_alive_interval;
 539                 tv.tv_usec = 0;
 540                 tvp = &tv;
 541         }
 542         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 543         if (ret < 0) {
 544                 char buf[100];
 545
 546                 /*
 547                  * We have to clear the select masks, because we return.
 548                  * We have to return, because the mainloop checks for the flags
 549                  * set by the signal handlers.
 550                  */
 551                 memset(*readsetp, 0, *nallocp);
 552                 memset(*writesetp, 0, *nallocp);
 553
 554                 if (errno == EINTR)
 555                         return;
 556                 /* Note: we might still have data in the buffers. */
 557                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 558                 buffer_append(&stderr_buffer, buf, strlen(buf));
 559                 quit_pending = 1;
 560         } else if (ret == 0)
 561                 server_alive_check();
 562 }
 563
 564 static void
 565 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 566 {
 567         /* Flush stdout and stderr buffers. */
 568         if (buffer_len(bout) > 0)
 569                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 570         if (buffer_len(berr) > 0)
 571                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 572
 573         leave_raw_mode();
 574
 575         /*
 576          * Free (and clear) the buffer to reduce the amount of data that gets
 577          * written to swap.
 578          */
 579         buffer_free(bin);
 580         buffer_free(bout);
 581         buffer_free(berr);
 582
 583         /* Send the suspend signal to the program itself. */
 584         kill(getpid(), SIGTSTP);
 585
 586         /* Reset window sizes in case they have changed */
 587         received_window_change_signal = 1;
 588
 589         /* OK, we have been continued by the user. Reinitialize buffers. */
 590         buffer_init(bin);
 591         buffer_init(bout);
 592         buffer_init(berr);
 593
 594         enter_raw_mode();
 595 }
 596
 597 static void
 598 client_process_net_input(fd_set *readset)
 599 {
 600         int len;
 601         char buf[8192];
 602
 603         /*
 604          * Read input from the server, and add any such data to the buffer of
 605          * the packet subsystem.
 606          */
 607         if (FD_ISSET(connection_in, readset)) {
 608                 /* Read as much as possible. */
 609                 len = read(connection_in, buf, sizeof(buf));
 610                 if (len == 0) {
 611                         /* Received EOF.  The remote host has closed the connection. */
 612                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 613                                  host);
 614                         buffer_append(&stderr_buffer, buf, strlen(buf));
 615                         quit_pending = 1;
 616                         return;
 617                 }
 618                 /*
 619                  * There is a kernel bug on Solaris that causes select to
 620                  * sometimes wake up even though there is no data available.
 621                  */
 622                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 623                         len = 0;
 624
 625                 if (len < 0) {
 626                         /* An error has encountered.  Perhaps there is a network problem. */
 627                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 628                                  host, strerror(errno));
 629                         buffer_append(&stderr_buffer, buf, strlen(buf));
 630                         quit_pending = 1;
 631                         return;
 632                 }
 633                 packet_process_incoming(buf, len);
 634         }
 635 }
 636
 637 static void
 638 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 639 {
 640         int id;
 641         Channel *c;
 642
 643         id = packet_get_int();
 644         packet_check_eom();
 645
 646         if ((c = channel_lookup(id)) == NULL) {
 647                 error("%s: no channel for id %d", __func__, id);
 648                 return;
 649         }
 650
 651         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 652                 debug2("Request suceeded on channel %d", id);
 653         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 654                 error("Request failed on channel %d", id);
 655                 channel_free(c);
 656         }
 657 }
 658
 659 static void
 660 client_extra_session2_setup(int id, void *arg)
 661 {
 662         struct confirm_ctx *cctx = arg;
 663         const char *display;
 664         Channel *c;
 665         int i;
 666
 667         if (cctx == NULL)
 668                 fatal("%s: cctx == NULL", __func__);
 669         if ((c = channel_lookup(id)) == NULL)
 670                 fatal("%s: no channel for id %d", __func__, id);
 671
 672         display = getenv("DISPLAY");
 673         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 674                 char *proto, *data;
 675                 /* Get reasonable local authentication information. */
 676                 client_x11_get_proto(display, options.xauth_location,
 677                     options.forward_x11_trusted, &proto, &data);
 678                 /* Request forwarding with authentication spoofing. */
 679                 debug("Requesting X11 forwarding with authentication spoofing.");
 680                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 681                 /* XXX wait for reply */
 682         }
 683
 684         if (cctx->want_agent_fwd && options.forward_agent) {
 685                 debug("Requesting authentication agent forwarding.");
 686                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 687                 packet_send();
 688         }
 689
 690         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 691             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 692             client_subsystem_reply);
 693
 694         c->confirm_ctx = NULL;
 695         buffer_free(&cctx->cmd);
 696         xfree(cctx->term);
 697         if (cctx->env != NULL) {
 698                 for (i = 0; cctx->env[i] != NULL; i++)
 699                         xfree(cctx->env[i]);
 700                 xfree(cctx->env);
 701         }
 702         xfree(cctx);
 703 }
 704
 705 static void
 706 client_process_control(fd_set *readset)
 707 {
 708         Buffer m;
 709         Channel *c;
 710         int client_fd, new_fd[3], ver, allowed, window, packetmax;
 711         socklen_t addrlen;
 712         struct sockaddr_storage addr;
 713         struct confirm_ctx *cctx;
 714         char *cmd;
 715         u_int i, len, env_len, command, flags;
 716         uid_t euid;
 717         gid_t egid;
 718
 719         /*
 720          * Accept connection on control socket
 721          */
 722         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 723                 return;
 724
 725         memset(&addr, 0, sizeof(addr));
 726         addrlen = sizeof(addr);
 727         if ((client_fd = accept(control_fd,
 728             (struct sockaddr*)&addr, &addrlen)) == -1) {
 729                 error("%s accept: %s", __func__, strerror(errno));
 730                 return;
 731         }
 732
 733         if (getpeereid(client_fd, &euid, &egid) < 0) {
 734                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 735                 close(client_fd);
 736                 return;
 737         }
 738         if ((euid != 0) && (getuid() != euid)) {
 739                 error("control mode uid mismatch: peer euid %u != uid %u",
 740                     (u_int) euid, (u_int) getuid());
 741                 close(client_fd);
 742                 return;
 743         }
 744
 745         unset_nonblock(client_fd);
 746
 747         /* Read command */
 748         buffer_init(&m);
 749         if (ssh_msg_recv(client_fd, &m) == -1) {
 750                 error("%s: client msg_recv failed", __func__);
 751                 close(client_fd);
 752                 buffer_free(&m);
 753                 return;
 754         }
 755         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 756                 error("%s: wrong client version %d", __func__, ver);
 757                 buffer_free(&m);
 758                 close(client_fd);
 759                 return;
 760         }
 761
 762         allowed = 1;
 763         command = buffer_get_int(&m);
 764         flags = buffer_get_int(&m);
 765
 766         buffer_clear(&m);
 767
 768         switch (command) {
 769         case SSHMUX_COMMAND_OPEN:
 770                 if (options.control_master == SSHCTL_MASTER_ASK ||
 771                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 772                         allowed = ask_permission("Allow shared connection "
 773                             "to %s? ", host);
 774                 /* continue below */
 775                 break;
 776         case SSHMUX_COMMAND_TERMINATE:
 777                 if (options.control_master == SSHCTL_MASTER_ASK ||
 778                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 779                         allowed = ask_permission("Terminate shared connection "
 780                             "to %s? ", host);
 781                 if (allowed)
 782                         quit_pending = 1;
 783                 /* FALLTHROUGH */
 784         case SSHMUX_COMMAND_ALIVE_CHECK:
 785                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 786                 buffer_clear(&m);
 787                 buffer_put_int(&m, allowed);
 788                 buffer_put_int(&m, getpid());
 789                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 790                         error("%s: client msg_send failed", __func__);
 791                         close(client_fd);
 792                         buffer_free(&m);
 793                         return;
 794                 }
 795                 buffer_free(&m);
 796                 close(client_fd);
 797                 return;
 798         default:
 799                 error("Unsupported command %d", command);
 800                 buffer_free(&m);
 801                 close(client_fd);
 802                 return;
 803         }
 804
 805         /* Reply for SSHMUX_COMMAND_OPEN */
 806         buffer_clear(&m);
 807         buffer_put_int(&m, allowed);
 808         buffer_put_int(&m, getpid());
 809         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 810                 error("%s: client msg_send failed", __func__);
 811                 close(client_fd);
 812                 buffer_free(&m);
 813                 return;
 814         }
 815
 816         if (!allowed) {
 817                 error("Refused control connection");
 818                 close(client_fd);
 819                 buffer_free(&m);
 820                 return;
 821         }
 822
 823         buffer_clear(&m);
 824         if (ssh_msg_recv(client_fd, &m) == -1) {
 825                 error("%s: client msg_recv failed", __func__);
 826                 close(client_fd);
 827                 buffer_free(&m);
 828                 return;
 829         }
 830         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 831                 error("%s: wrong client version %d", __func__, ver);
 832                 buffer_free(&m);
 833                 close(client_fd);
 834                 return;
 835         }
 836
 837         cctx = xcalloc(1, sizeof(*cctx));
 838         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 839         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 840         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 841         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 842         cctx->term = buffer_get_string(&m, &len);
 843
 844         cmd = buffer_get_string(&m, &len);
 845         buffer_init(&cctx->cmd);
 846         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 847
 848         env_len = buffer_get_int(&m);
 849         env_len = MIN(env_len, 4096);
 850         debug3("%s: receiving %d env vars", __func__, env_len);
 851         if (env_len != 0) {
 852                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 853                 for (i = 0; i < env_len; i++)
 854                         cctx->env[i] = buffer_get_string(&m, &len);
 855                 cctx->env[i] = NULL;
 856         }
 857
 858         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 859             cctx->want_tty, cctx->want_subsys, cmd);
 860         xfree(cmd);
 861
 862         /* Gather fds from client */
 863         new_fd[0] = mm_receive_fd(client_fd);
 864         new_fd[1] = mm_receive_fd(client_fd);
 865         new_fd[2] = mm_receive_fd(client_fd);
 866
 867         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 868             new_fd[0], new_fd[1], new_fd[2]);
 869
 870         /* Try to pick up ttymodes from client before it goes raw */
 871         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 872                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 873
 874         /* This roundtrip is just for synchronisation of ttymodes */
 875         buffer_clear(&m);
 876         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 877                 error("%s: client msg_send failed", __func__);
 878                 close(client_fd);
 879                 close(new_fd[0]);
 880                 close(new_fd[1]);
 881                 close(new_fd[2]);
 882                 buffer_free(&m);
 883                 xfree(cctx->term);
 884                 if (env_len != 0) {
 885                         for (i = 0; i < env_len; i++)
 886                                 xfree(cctx->env[i]);
 887                         xfree(cctx->env);
 888                 }
 889                 return;
 890         }
 891         buffer_free(&m);
 892
 893         /* enable nonblocking unless tty */
 894         if (!isatty(new_fd[0]))
 895                 set_nonblock(new_fd[0]);
 896         if (!isatty(new_fd[1]))
 897                 set_nonblock(new_fd[1]);
 898         if (!isatty(new_fd[2]))
 899                 set_nonblock(new_fd[2]);
 900
 901         set_nonblock(client_fd);
 902
 903         window = CHAN_SES_WINDOW_DEFAULT;
 904         packetmax = CHAN_SES_PACKET_DEFAULT;
 905         if (cctx->want_tty) {
 906                 window >>= 1;
 907                 packetmax >>= 1;
 908         }
 909
 910         c = channel_new("session", SSH_CHANNEL_OPENING,
 911             new_fd[0], new_fd[1], new_fd[2], window, packetmax,
 912             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 913
 914         /* XXX */
 915         c->ctl_fd = client_fd;
 916
 917         debug3("%s: channel_new: %d", __func__, c->self);
 918
 919         channel_send_open(c->self);
 920         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 921 }
 922
 923 static void
 924 process_cmdline(void)
 925 {
 926         void (*handler)(int);
 927         char *s, *cmd, *cancel_host;
 928         int delete = 0;
 929         int local = 0;
 930         u_short cancel_port;
 931         Forward fwd;
 932
 933         leave_raw_mode();
 934         handler = signal(SIGINT, SIG_IGN);
 935         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 936         if (s == NULL)
 937                 goto out;
 938         while (isspace(*s))
 939                 s++;
 940         if (*s == '-')
 941                 s++;    /* Skip cmdline '-', if any */
 942         if (*s == '\0')
 943                 goto out;
 944
 945         if (*s == 'h' || *s == 'H' || *s == '?') {
 946                 logit("Commands:");
 947                 logit("      -L[bind_address:]port:host:hostport    "
 948                     "Request local forward");
 949                 logit("      -R[bind_address:]port:host:hostport    "
 950                     "Request remote forward");
 951                 logit("      -KR[bind_address:]port                 "
 952                     "Cancel remote forward");
 953                 if (!options.permit_local_command)
 954                         goto out;
 955                 logit("      !args                                  "
 956                     "Execute local command");
 957                 goto out;
 958         }
 959
 960         if (*s == '!' && options.permit_local_command) {
 961                 s++;
 962                 ssh_local_cmd(s);
 963                 goto out;
 964         }
 965
 966         if (*s == 'K') {
 967                 delete = 1;
 968                 s++;
 969         }
 970         if (*s != 'L' && *s != 'R') {
 971                 logit("Invalid command.");
 972                 goto out;
 973         }
 974         if (*s == 'L')
 975                 local = 1;
 976         if (local && delete) {
 977                 logit("Not supported.");
 978                 goto out;
 979         }
 980         if ((!local || delete) && !compat20) {
 981                 logit("Not supported for SSH protocol version 1.");
 982                 goto out;
 983         }
 984
 985         while (isspace(*++s))
 986                 ;
 987
 988         if (delete) {
 989                 cancel_port = 0;
 990                 cancel_host = hpdelim(&s);      /* may be NULL */
 991                 if (s != NULL) {
 992                         cancel_port = a2port(s);
 993                         cancel_host = cleanhostname(cancel_host);
 994                 } else {
 995                         cancel_port = a2port(cancel_host);
 996                         cancel_host = NULL;
 997                 }
 998                 if (cancel_port == 0) {
 999                         logit("Bad forwarding close port");
1000                         goto out;
1001                 }
1002                 channel_request_rforward_cancel(cancel_host, cancel_port);
1003         } else {
1004                 if (!parse_forward(&fwd, s)) {
1005                         logit("Bad forwarding specification.");
1006                         goto out;
1007                 }
1008                 if (local) {
1009                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1010                             fwd.listen_port, fwd.connect_host,
1011                             fwd.connect_port, options.gateway_ports) < 0) {
1012                                 logit("Port forwarding failed.");
1013                                 goto out;
1014                         }
1015                 } else {
1016                         if (channel_request_remote_forwarding(fwd.listen_host,
1017                             fwd.listen_port, fwd.connect_host,
1018                             fwd.connect_port) < 0) {
1019                                 logit("Port forwarding failed.");
1020                                 goto out;
1021                         }
1022                 }
1023
1024                 logit("Forwarding port.");
1025         }
1026
1027 out:
1028         signal(SIGINT, handler);
1029         enter_raw_mode();
1030         if (cmd)
1031                 xfree(cmd);
1032 }
1033
1034 /* process the characters one by one */
1035 static int
1036 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1037 {
1038         char string[1024];
1039         pid_t pid;
1040         int bytes = 0;
1041         u_int i;
1042         u_char ch;
1043         char *s;
1044
1045         if (len <= 0)
1046                 return (0);
1047
1048         for (i = 0; i < (u_int)len; i++) {
1049                 /* Get one character at a time. */
1050                 ch = buf[i];
1051
1052                 if (escape_pending) {
1053                         /* We have previously seen an escape character. */
1054                         /* Clear the flag now. */
1055                         escape_pending = 0;
1056
1057                         /* Process the escaped character. */
1058                         switch (ch) {
1059                         case '.':
1060                                 /* Terminate the connection. */
1061                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1062                                 buffer_append(berr, string, strlen(string));
1063
1064                                 quit_pending = 1;
1065                                 return -1;
1066
1067                         case 'Z' - 64:
1068                                 /* Suspend the program. */
1069                                 /* Print a message to that effect to the user. */
1070                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1071                                 buffer_append(berr, string, strlen(string));
1072
1073                                 /* Restore terminal modes and suspend. */
1074                                 client_suspend_self(bin, bout, berr);
1075
1076                                 /* We have been continued. */
1077                                 continue;
1078
1079                         case 'B':
1080                                 if (compat20) {
1081                                         snprintf(string, sizeof string,
1082                                             "%cB\r\n", escape_char);
1083                                         buffer_append(berr, string,
1084                                             strlen(string));
1085                                         channel_request_start(session_ident,
1086                                             "break", 0);
1087                                         packet_put_int(1000);
1088                                         packet_send();
1089                                 }
1090                                 continue;
1091
1092                         case 'R':
1093                                 if (compat20) {
1094                                         if (datafellows & SSH_BUG_NOREKEY)
1095                                                 logit("Server does not support re-keying");
1096                                         else
1097                                                 need_rekeying = 1;
1098                                 }
1099                                 continue;
1100
1101                         case '&':
1102                                 /*
1103                                  * Detach the program (continue to serve connections,
1104                                  * but put in background and no more new connections).
1105                                  */
1106                                 /* Restore tty modes. */
1107                                 leave_raw_mode();
1108
1109                                 /* Stop listening for new connections. */
1110                                 channel_stop_listening();
1111
1112                                 snprintf(string, sizeof string,
1113                                     "%c& [backgrounded]\n", escape_char);
1114                                 buffer_append(berr, string, strlen(string));
1115
1116                                 /* Fork into background. */
1117                                 pid = fork();
1118                                 if (pid < 0) {
1119                                         error("fork: %.100s", strerror(errno));
1120                                         continue;
1121                                 }
1122                                 if (pid != 0) { /* This is the parent. */
1123                                         /* The parent just exits. */
1124                                         exit(0);
1125                                 }
1126                                 /* The child continues serving connections. */
1127                                 if (compat20) {
1128                                         buffer_append(bin, "\004", 1);
1129                                         /* fake EOF on stdin */
1130                                         return -1;
1131                                 } else if (!stdin_eof) {
1132                                         /*
1133                                          * Sending SSH_CMSG_EOF alone does not always appear
1134                                          * to be enough.  So we try to send an EOF character
1135                                          * first.
1136                                          */
1137                                         packet_start(SSH_CMSG_STDIN_DATA);
1138                                         packet_put_string("\004", 1);
1139                                         packet_send();
1140                                         /* Close stdin. */
1141                                         stdin_eof = 1;
1142                                         if (buffer_len(bin) == 0) {
1143                                                 packet_start(SSH_CMSG_EOF);
1144                                                 packet_send();
1145                                         }
1146                                 }
1147                                 continue;
1148
1149                         case '?':
1150                                 snprintf(string, sizeof string,
1151 "%c?\r\n\
1152 Supported escape sequences:\r\n\
1153 %c.  - terminate connection\r\n\
1154 %cB  - send a BREAK to the remote system\r\n\
1155 %cC  - open a command line\r\n\
1156 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1157 %c^Z - suspend ssh\r\n\
1158 %c#  - list forwarded connections\r\n\
1159 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1160 %c?  - this message\r\n\
1161 %c%c  - send the escape character by typing it twice\r\n\
1162 (Note that escapes are only recognized immediately after newline.)\r\n",
1163                                     escape_char, escape_char, escape_char, escape_char,
1164                                     escape_char, escape_char, escape_char, escape_char,
1165                                     escape_char, escape_char, escape_char);
1166                                 buffer_append(berr, string, strlen(string));
1167                                 continue;
1168
1169                         case '#':
1170                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1171                                 buffer_append(berr, string, strlen(string));
1172                                 s = channel_open_message();
1173                                 buffer_append(berr, s, strlen(s));
1174                                 xfree(s);
1175                                 continue;
1176
1177                         case 'C':
1178                                 process_cmdline();
1179                                 continue;
1180
1181                         default:
1182                                 if (ch != escape_char) {
1183                                         buffer_put_char(bin, escape_char);
1184                                         bytes++;
1185                                 }
1186                                 /* Escaped characters fall through here */
1187                                 break;
1188                         }
1189                 } else {
1190                         /*
1191                          * The previous character was not an escape char. Check if this
1192                          * is an escape.
1193                          */
1194                         if (last_was_cr && ch == escape_char) {
1195                                 /* It is. Set the flag and continue to next character. */
1196                                 escape_pending = 1;
1197                                 continue;
1198                         }
1199                 }
1200
1201                 /*
1202                  * Normal character.  Record whether it was a newline,
1203                  * and append it to the buffer.
1204                  */
1205                 last_was_cr = (ch == '\r' || ch == '\n');
1206                 buffer_put_char(bin, ch);
1207                 bytes++;
1208         }
1209         return bytes;
1210 }
1211
1212 static void
1213 client_process_input(fd_set *readset)
1214 {
1215         int len;
1216         char buf[8192];
1217
1218         /* Read input from stdin. */
1219         if (FD_ISSET(fileno(stdin), readset)) {
1220                 /* Read as much as possible. */
1221                 len = read(fileno(stdin), buf, sizeof(buf));
1222                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1223                         return;         /* we'll try again later */
1224                 if (len <= 0) {
1225                         /*
1226                          * Received EOF or error.  They are treated
1227                          * similarly, except that an error message is printed
1228                          * if it was an error condition.
1229                          */
1230                         if (len < 0) {
1231                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1232                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1233                         }
1234                         /* Mark that we have seen EOF. */
1235                         stdin_eof = 1;
1236                         /*
1237                          * Send an EOF message to the server unless there is
1238                          * data in the buffer.  If there is data in the
1239                          * buffer, no message will be sent now.  Code
1240                          * elsewhere will send the EOF when the buffer
1241                          * becomes empty if stdin_eof is set.
1242                          */
1243                         if (buffer_len(&stdin_buffer) == 0) {
1244                                 packet_start(SSH_CMSG_EOF);
1245                                 packet_send();
1246                         }
1247                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1248                         /*
1249                          * Normal successful read, and no escape character.
1250                          * Just append the data to buffer.
1251                          */
1252                         buffer_append(&stdin_buffer, buf, len);
1253                 } else {
1254                         /*
1255                          * Normal, successful read.  But we have an escape character
1256                          * and have to process the characters one by one.
1257                          */
1258                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1259                             &stderr_buffer, buf, len) == -1)
1260                                 return;
1261                 }
1262         }
1263 }
1264
1265 static void
1266 client_process_output(fd_set *writeset)
1267 {
1268         int len;
1269         char buf[100];
1270
1271         /* Write buffered output to stdout. */
1272         if (FD_ISSET(fileno(stdout), writeset)) {
1273                 /* Write as much data as possible. */
1274                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1275                     buffer_len(&stdout_buffer));
1276                 if (len <= 0) {
1277                         if (errno == EINTR || errno == EAGAIN)
1278                                 len = 0;
1279                         else {
1280                                 /*
1281                                  * An error or EOF was encountered.  Put an
1282                                  * error message to stderr buffer.
1283                                  */
1284                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1285                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1286                                 quit_pending = 1;
1287                                 return;
1288                         }
1289                 }
1290                 /* Consume printed data from the buffer. */
1291                 buffer_consume(&stdout_buffer, len);
1292                 stdout_bytes += len;
1293         }
1294         /* Write buffered output to stderr. */
1295         if (FD_ISSET(fileno(stderr), writeset)) {
1296                 /* Write as much data as possible. */
1297                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1298                     buffer_len(&stderr_buffer));
1299                 if (len <= 0) {
1300                         if (errno == EINTR || errno == EAGAIN)
1301                                 len = 0;
1302                         else {
1303                                 /* EOF or error, but can't even print error message. */
1304                                 quit_pending = 1;
1305                                 return;
1306                         }
1307                 }
1308                 /* Consume printed characters from the buffer. */
1309                 buffer_consume(&stderr_buffer, len);
1310                 stderr_bytes += len;
1311         }
1312 }
1313
1314 /*
1315  * Get packets from the connection input buffer, and process them as long as
1316  * there are packets available.
1317  *
1318  * Any unknown packets received during the actual
1319  * session cause the session to terminate.  This is
1320  * intended to make debugging easier since no
1321  * confirmations are sent.  Any compatible protocol
1322  * extensions must be negotiated during the
1323  * preparatory phase.
1324  */
1325
1326 static void
1327 client_process_buffered_input_packets(void)
1328 {
1329         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1330 }
1331
1332 /* scan buf[] for '~' before sending data to the peer */
1333
1334 static int
1335 simple_escape_filter(Channel *c, char *buf, int len)
1336 {
1337         /* XXX we assume c->extended is writeable */
1338         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1339 }
1340
1341 static void
1342 client_channel_closed(int id, void *arg)
1343 {
1344         channel_cancel_cleanup(id);
1345         session_closed = 1;
1346         leave_raw_mode();
1347 }
1348
1349 /*
1350  * Implements the interactive session with the server.  This is called after
1351  * the user has been authenticated, and a command has been started on the
1352  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1353  * used as an escape character for terminating or suspending the session.
1354  */
1355
1356 int
1357 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1358 {
1359         fd_set *readset = NULL, *writeset = NULL;
1360         double start_time, total_time;
1361         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1362         u_int nalloc = 0;
1363         char buf[100];
1364
1365         debug("Entering interactive session.");
1366
1367         start_time = get_current_time();
1368
1369         /* Initialize variables. */
1370         escape_pending = 0;
1371         last_was_cr = 1;
1372         exit_status = -1;
1373         stdin_eof = 0;
1374         buffer_high = 64 * 1024;
1375         connection_in = packet_get_connection_in();
1376         connection_out = packet_get_connection_out();
1377         max_fd = MAX(connection_in, connection_out);
1378         if (control_fd != -1)
1379                 max_fd = MAX(max_fd, control_fd);
1380
1381         if (!compat20) {
1382                 /* enable nonblocking unless tty */
1383                 if (!isatty(fileno(stdin)))
1384                         set_nonblock(fileno(stdin));
1385                 if (!isatty(fileno(stdout)))
1386                         set_nonblock(fileno(stdout));
1387                 if (!isatty(fileno(stderr)))
1388                         set_nonblock(fileno(stderr));
1389                 max_fd = MAX(max_fd, fileno(stdin));
1390                 max_fd = MAX(max_fd, fileno(stdout));
1391                 max_fd = MAX(max_fd, fileno(stderr));
1392         }
1393         stdin_bytes = 0;
1394         stdout_bytes = 0;
1395         stderr_bytes = 0;
1396         quit_pending = 0;
1397         escape_char = escape_char_arg;
1398
1399         /* Initialize buffers. */
1400         buffer_init(&stdin_buffer);
1401         buffer_init(&stdout_buffer);
1402         buffer_init(&stderr_buffer);
1403
1404         client_init_dispatch();
1405
1406         /*
1407          * Set signal handlers, (e.g. to restore non-blocking mode)
1408          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1409          */
1410         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1411                 signal(SIGHUP, signal_handler);
1412         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1413                 signal(SIGINT, signal_handler);
1414         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1415                 signal(SIGQUIT, signal_handler);
1416         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1417                 signal(SIGTERM, signal_handler);
1418         signal(SIGWINCH, window_change_handler);
1419
1420         if (have_pty)
1421                 enter_raw_mode();
1422
1423         if (compat20) {
1424                 session_ident = ssh2_chan_id;
1425                 if (escape_char != SSH_ESCAPECHAR_NONE)
1426                         channel_register_filter(session_ident,
1427                             simple_escape_filter, NULL);
1428                 if (session_ident != -1)
1429                         channel_register_cleanup(session_ident,
1430                             client_channel_closed, 0);
1431         } else {
1432                 /* Check if we should immediately send eof on stdin. */
1433                 client_check_initial_eof_on_stdin();
1434         }
1435
1436         /* Main loop of the client for the interactive session mode. */
1437         while (!quit_pending) {
1438
1439                 /* Process buffered packets sent by the server. */
1440                 client_process_buffered_input_packets();
1441
1442                 if (compat20 && session_closed && !channel_still_open())
1443                         break;
1444
1445                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1446
1447                 if (rekeying) {
1448                         debug("rekeying in progress");
1449                 } else {
1450                         /*
1451                          * Make packets of buffered stdin data, and buffer
1452                          * them for sending to the server.
1453                          */
1454                         if (!compat20)
1455                                 client_make_packets_from_stdin_data();
1456
1457                         /*
1458                          * Make packets from buffered channel data, and
1459                          * enqueue them for sending to the server.
1460                          */
1461                         if (packet_not_very_much_data_to_write())
1462                                 channel_output_poll();
1463
1464                         /*
1465                          * Check if the window size has changed, and buffer a
1466                          * message about it to the server if so.
1467                          */
1468                         client_check_window_change();
1469
1470                         if (quit_pending)
1471                                 break;
1472                 }
1473                 /*
1474                  * Wait until we have something to do (something becomes
1475                  * available on one of the descriptors).
1476                  */
1477                 max_fd2 = max_fd;
1478                 client_wait_until_can_do_something(&readset, &writeset,
1479                     &max_fd2, &nalloc, rekeying);
1480
1481                 if (quit_pending)
1482                         break;
1483
1484                 /* Do channel operations unless rekeying in progress. */
1485                 if (!rekeying) {
1486                         channel_after_select(readset, writeset);
1487                         if (need_rekeying || packet_need_rekeying()) {
1488                                 debug("need rekeying");
1489                                 xxx_kex->done = 0;
1490                                 kex_send_kexinit(xxx_kex);
1491                                 need_rekeying = 0;
1492                         }
1493                 }
1494
1495                 /* Buffer input from the connection.  */
1496                 client_process_net_input(readset);
1497
1498                 /* Accept control connections.  */
1499                 client_process_control(readset);
1500
1501                 if (quit_pending)
1502                         break;
1503
1504                 if (!compat20) {
1505                         /* Buffer data from stdin */
1506                         client_process_input(readset);
1507                         /*
1508                          * Process output to stdout and stderr.  Output to
1509                          * the connection is processed elsewhere (above).
1510                          */
1511                         client_process_output(writeset);
1512                 }
1513
1514                 /* Send as much buffered packet data as possible to the sender. */
1515                 if (FD_ISSET(connection_out, writeset))
1516                         packet_write_poll();
1517         }
1518         if (readset)
1519                 xfree(readset);
1520         if (writeset)
1521                 xfree(writeset);
1522
1523         /* Terminate the session. */
1524
1525         /* Stop watching for window change. */
1526         signal(SIGWINCH, SIG_DFL);
1527
1528         channel_free_all();
1529
1530         if (have_pty)
1531                 leave_raw_mode();
1532
1533         /* restore blocking io */
1534         if (!isatty(fileno(stdin)))
1535                 unset_nonblock(fileno(stdin));
1536         if (!isatty(fileno(stdout)))
1537                 unset_nonblock(fileno(stdout));
1538         if (!isatty(fileno(stderr)))
1539                 unset_nonblock(fileno(stderr));
1540
1541         /*
1542          * If there was no shell or command requested, there will be no remote
1543          * exit status to be returned.  In that case, clear error code if the
1544          * connection was deliberately terminated at this end.
1545          */
1546         if (no_shell_flag && received_signal == SIGTERM) {
1547                 received_signal = 0;
1548                 exit_status = 0;
1549         }
1550
1551         if (received_signal)
1552                 fatal("Killed by signal %d.", (int) received_signal);
1553
1554         /*
1555          * In interactive mode (with pseudo tty) display a message indicating
1556          * that the connection has been closed.
1557          */
1558         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1559                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1560                 buffer_append(&stderr_buffer, buf, strlen(buf));
1561         }
1562
1563         /* Output any buffered data for stdout. */
1564         while (buffer_len(&stdout_buffer) > 0) {
1565                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1566                     buffer_len(&stdout_buffer));
1567                 if (len <= 0) {
1568                         error("Write failed flushing stdout buffer.");
1569                         break;
1570                 }
1571                 buffer_consume(&stdout_buffer, len);
1572                 stdout_bytes += len;
1573         }
1574
1575         /* Output any buffered data for stderr. */
1576         while (buffer_len(&stderr_buffer) > 0) {
1577                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1578                     buffer_len(&stderr_buffer));
1579                 if (len <= 0) {
1580                         error("Write failed flushing stderr buffer.");
1581                         break;
1582                 }
1583                 buffer_consume(&stderr_buffer, len);
1584                 stderr_bytes += len;
1585         }
1586
1587         /* Clear and free any buffers. */
1588         memset(buf, 0, sizeof(buf));
1589         buffer_free(&stdin_buffer);
1590         buffer_free(&stdout_buffer);
1591         buffer_free(&stderr_buffer);
1592
1593         /* Report bytes transferred, and transfer rates. */
1594         total_time = get_current_time() - start_time;
1595         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1596             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1597         if (total_time > 0)
1598                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1599                     stdin_bytes / total_time, stdout_bytes / total_time,
1600                     stderr_bytes / total_time);
1601
1602         /* Return the exit status of the program. */
1603         debug("Exit status %d", exit_status);
1604         return exit_status;
1605 }
1606
1607 /*********/
1608
1609 static void
1610 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1611 {
1612         u_int data_len;
1613         char *data = packet_get_string(&data_len);
1614         packet_check_eom();
1615         buffer_append(&stdout_buffer, data, data_len);
1616         memset(data, 0, data_len);
1617         xfree(data);
1618 }
1619 static void
1620 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1621 {
1622         u_int data_len;
1623         char *data = packet_get_string(&data_len);
1624         packet_check_eom();
1625         buffer_append(&stderr_buffer, data, data_len);
1626         memset(data, 0, data_len);
1627         xfree(data);
1628 }
1629 static void
1630 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1631 {
1632         exit_status = packet_get_int();
1633         packet_check_eom();
1634         /* Acknowledge the exit. */
1635         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1636         packet_send();
1637         /*
1638          * Must wait for packet to be sent since we are
1639          * exiting the loop.
1640          */
1641         packet_write_wait();
1642         /* Flag that we want to exit. */
1643         quit_pending = 1;
1644 }
1645 static void
1646 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1647 {
1648         Channel *c = NULL;
1649         int remote_id, sock;
1650
1651         /* Read the remote channel number from the message. */
1652         remote_id = packet_get_int();
1653         packet_check_eom();
1654
1655         /*
1656          * Get a connection to the local authentication agent (this may again
1657          * get forwarded).
1658          */
1659         sock = ssh_get_authentication_socket();
1660
1661         /*
1662          * If we could not connect the agent, send an error message back to
1663          * the server. This should never happen unless the agent dies,
1664          * because authentication forwarding is only enabled if we have an
1665          * agent.
1666          */
1667         if (sock >= 0) {
1668                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1669                     -1, 0, 0, 0, "authentication agent connection", 1);
1670                 c->remote_id = remote_id;
1671                 c->force_drain = 1;
1672         }
1673         if (c == NULL) {
1674                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1675                 packet_put_int(remote_id);
1676         } else {
1677                 /* Send a confirmation to the remote host. */
1678                 debug("Forwarding authentication connection.");
1679                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1680                 packet_put_int(remote_id);
1681                 packet_put_int(c->self);
1682         }
1683         packet_send();
1684 }
1685
1686 static Channel *
1687 client_request_forwarded_tcpip(const char *request_type, int rchan)
1688 {
1689         Channel *c = NULL;
1690         char *listen_address, *originator_address;
1691         int listen_port, originator_port;
1692         int sock;
1693
1694         /* Get rest of the packet */
1695         listen_address = packet_get_string(NULL);
1696         listen_port = packet_get_int();
1697         originator_address = packet_get_string(NULL);
1698         originator_port = packet_get_int();
1699         packet_check_eom();
1700
1701         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1702             listen_address, listen_port, originator_address, originator_port);
1703
1704         sock = channel_connect_by_listen_address(listen_port);
1705         if (sock < 0) {
1706                 xfree(originator_address);
1707                 xfree(listen_address);
1708                 return NULL;
1709         }
1710         c = channel_new("forwarded-tcpip",
1711             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1712             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1713             originator_address, 1);
1714         xfree(originator_address);
1715         xfree(listen_address);
1716         return c;
1717 }
1718
1719 static Channel *
1720 client_request_x11(const char *request_type, int rchan)
1721 {
1722         Channel *c = NULL;
1723         char *originator;
1724         int originator_port;
1725         int sock;
1726
1727         if (!options.forward_x11) {
1728                 error("Warning: ssh server tried X11 forwarding.");
1729                 error("Warning: this is probably a break-in attempt by a malicious server.");
1730                 return NULL;
1731         }
1732         originator = packet_get_string(NULL);
1733         if (datafellows & SSH_BUG_X11FWD) {
1734                 debug2("buggy server: x11 request w/o originator_port");
1735                 originator_port = 0;
1736         } else {
1737                 originator_port = packet_get_int();
1738         }
1739         packet_check_eom();
1740         /* XXX check permission */
1741         debug("client_request_x11: request from %s %d", originator,
1742             originator_port);
1743         xfree(originator);
1744         sock = x11_connect_display();
1745         if (sock < 0)
1746                 return NULL;
1747         c = channel_new("x11",
1748             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1749             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1750         c->force_drain = 1;
1751         return c;
1752 }
1753
1754 static Channel *
1755 client_request_agent(const char *request_type, int rchan)
1756 {
1757         Channel *c = NULL;
1758         int sock;
1759
1760         if (!options.forward_agent) {
1761                 error("Warning: ssh server tried agent forwarding.");
1762                 error("Warning: this is probably a break-in attempt by a malicious server.");
1763                 return NULL;
1764         }
1765         sock = ssh_get_authentication_socket();
1766         if (sock < 0)
1767                 return NULL;
1768         c = channel_new("authentication agent connection",
1769             SSH_CHANNEL_OPEN, sock, sock, -1,
1770             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1771             "authentication agent connection", 1);
1772         c->force_drain = 1;
1773         return c;
1774 }
1775
1776 int
1777 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1778 {
1779         Channel *c;
1780         int fd;
1781
1782         if (tun_mode == SSH_TUNMODE_NO)
1783                 return 0;
1784
1785         if (!compat20) {
1786                 error("Tunnel forwarding is not support for protocol 1");
1787                 return -1;
1788         }
1789
1790         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1791
1792         /* Open local tunnel device */
1793         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1794                 error("Tunnel device open failed.");
1795                 return -1;
1796         }
1797
1798         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1799             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1800         c->datagram = 1;
1801
1802 #if defined(SSH_TUN_FILTER)
1803         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1804                 channel_register_filter(c->self, sys_tun_infilter,
1805                     sys_tun_outfilter);
1806 #endif
1807
1808         packet_start(SSH2_MSG_CHANNEL_OPEN);
1809         packet_put_cstring("tun@openssh.com");
1810         packet_put_int(c->self);
1811         packet_put_int(c->local_window_max);
1812         packet_put_int(c->local_maxpacket);
1813         packet_put_int(tun_mode);
1814         packet_put_int(remote_tun);
1815         packet_send();
1816
1817         return 0;
1818 }
1819
1820 /* XXXX move to generic input handler */
1821 static void
1822 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1823 {
1824         Channel *c = NULL;
1825         char *ctype;
1826         int rchan;
1827         u_int rmaxpack, rwindow, len;
1828
1829         ctype = packet_get_string(&len);
1830         rchan = packet_get_int();
1831         rwindow = packet_get_int();
1832         rmaxpack = packet_get_int();
1833
1834         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1835             ctype, rchan, rwindow, rmaxpack);
1836
1837         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1838                 c = client_request_forwarded_tcpip(ctype, rchan);
1839         } else if (strcmp(ctype, "x11") == 0) {
1840                 c = client_request_x11(ctype, rchan);
1841         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1842                 c = client_request_agent(ctype, rchan);
1843         }
1844 /* XXX duplicate : */
1845         if (c != NULL) {
1846                 debug("confirm %s", ctype);
1847                 c->remote_id = rchan;
1848                 c->remote_window = rwindow;
1849                 c->remote_maxpacket = rmaxpack;
1850                 if (c->type != SSH_CHANNEL_CONNECTING) {
1851                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1852                         packet_put_int(c->remote_id);
1853                         packet_put_int(c->self);
1854                         packet_put_int(c->local_window);
1855                         packet_put_int(c->local_maxpacket);
1856                         packet_send();
1857                 }
1858         } else {
1859                 debug("failure %s", ctype);
1860                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1861                 packet_put_int(rchan);
1862                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1863                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1864                         packet_put_cstring("open failed");
1865                         packet_put_cstring("");
1866                 }
1867                 packet_send();
1868         }
1869         xfree(ctype);
1870 }
1871 static void
1872 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1873 {
1874         Channel *c = NULL;
1875         int exitval, id, reply, success = 0;
1876         char *rtype;
1877
1878         id = packet_get_int();
1879         rtype = packet_get_string(NULL);
1880         reply = packet_get_char();
1881
1882         debug("client_input_channel_req: channel %d rtype %s reply %d",
1883             id, rtype, reply);
1884
1885         if (id == -1) {
1886                 error("client_input_channel_req: request for channel -1");
1887         } else if ((c = channel_lookup(id)) == NULL) {
1888                 error("client_input_channel_req: channel %d: unknown channel", id);
1889         } else if (strcmp(rtype, "exit-status") == 0) {
1890                 exitval = packet_get_int();
1891                 if (id == session_ident) {
1892                         success = 1;
1893                         exit_status = exitval;
1894                 } else if (c->ctl_fd == -1) {
1895                         error("client_input_channel_req: unexpected channel %d",
1896                             session_ident);
1897                 } else {
1898                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1899                         success = 1;
1900                 }
1901                 packet_check_eom();
1902         }
1903         if (reply) {
1904                 packet_start(success ?
1905                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1906                 packet_put_int(id);
1907                 packet_send();
1908         }
1909         xfree(rtype);
1910 }
1911 static void
1912 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1913 {
1914         char *rtype;
1915         int want_reply;
1916         int success = 0;
1917
1918         rtype = packet_get_string(NULL);
1919         want_reply = packet_get_char();
1920         debug("client_input_global_request: rtype %s want_reply %d",
1921             rtype, want_reply);
1922         if (want_reply) {
1923                 packet_start(success ?
1924                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1925                 packet_send();
1926                 packet_write_wait();
1927         }
1928         xfree(rtype);
1929 }
1930
1931 void
1932 client_session2_setup(int id, int want_tty, int want_subsystem,
1933     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1934     dispatch_fn *subsys_repl)
1935 {
1936         int len;
1937         Channel *c = NULL;
1938
1939         debug2("%s: id %d", __func__, id);
1940
1941         if ((c = channel_lookup(id)) == NULL)
1942                 fatal("client_session2_setup: channel %d: unknown channel", id);
1943
1944         if (want_tty) {
1945                 struct winsize ws;
1946                 struct termios tio;
1947
1948                 /* Store window size in the packet. */
1949                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1950                         memset(&ws, 0, sizeof(ws));
1951
1952                 channel_request_start(id, "pty-req", 0);
1953                 packet_put_cstring(term != NULL ? term : "");
1954                 packet_put_int((u_int)ws.ws_col);
1955                 packet_put_int((u_int)ws.ws_row);
1956                 packet_put_int((u_int)ws.ws_xpixel);
1957                 packet_put_int((u_int)ws.ws_ypixel);
1958                 tio = get_saved_tio();
1959                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1960                 packet_send();
1961                 /* XXX wait for reply */
1962                 c->client_tty = 1;
1963         }
1964
1965         /* Transfer any environment variables from client to server */
1966         if (options.num_send_env != 0 && env != NULL) {
1967                 int i, j, matched;
1968                 char *name, *val;
1969
1970                 debug("Sending environment.");
1971                 for (i = 0; env[i] != NULL; i++) {
1972                         /* Split */
1973                         name = xstrdup(env[i]);
1974                         if ((val = strchr(name, '=')) == NULL) {
1975                                 xfree(name);
1976                                 continue;
1977                         }
1978                         *val++ = '\0';
1979
1980                         matched = 0;
1981                         for (j = 0; j < options.num_send_env; j++) {
1982                                 if (match_pattern(name, options.send_env[j])) {
1983                                         matched = 1;
1984                                         break;
1985                                 }
1986                         }
1987                         if (!matched) {
1988                                 debug3("Ignored env %s", name);
1989                                 xfree(name);
1990                                 continue;
1991                         }
1992
1993                         debug("Sending env %s = %s", name, val);
1994                         channel_request_start(id, "env", 0);
1995                         packet_put_cstring(name);
1996                         packet_put_cstring(val);
1997                         packet_send();
1998                         xfree(name);
1999                 }
2000         }
2001
2002         len = buffer_len(cmd);
2003         if (len > 0) {
2004                 if (len > 900)
2005                         len = 900;
2006                 if (want_subsystem) {
2007                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
2008                         channel_request_start(id, "subsystem", subsys_repl != NULL);
2009                         if (subsys_repl != NULL) {
2010                                 /* register callback for reply */
2011                                 /* XXX we assume that client_loop has already been called */
2012                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
2013                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
2014                         }
2015                 } else {
2016                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
2017                         channel_request_start(id, "exec", 0);
2018                 }
2019                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2020                 packet_send();
2021         } else {
2022                 channel_request_start(id, "shell", 0);
2023                 packet_send();
2024         }
2025 }
2026
2027 static void
2028 client_init_dispatch_20(void)
2029 {
2030         dispatch_init(&dispatch_protocol_error);
2031
2032         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2033         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2034         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2035         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2036         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2037         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2038         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2039         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2040         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2041         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2042
2043         /* rekeying */
2044         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2045
2046         /* global request reply messages */
2047         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2048         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2049 }
2050 static void
2051 client_init_dispatch_13(void)
2052 {
2053         dispatch_init(NULL);
2054         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2055         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2056         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2057         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2058         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2059         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2060         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2061         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2062         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2063
2064         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2065             &client_input_agent_open : &deny_input_open);
2066         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2067             &x11_input_open : &deny_input_open);
2068 }
2069 static void
2070 client_init_dispatch_15(void)
2071 {
2072         client_init_dispatch_13();
2073         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2074         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2075 }
2076 static void
2077 client_init_dispatch(void)
2078 {
2079         if (compat20)
2080                 client_init_dispatch_20();
2081         else if (compat13)
2082                 client_init_dispatch_13();
2083         else
2084                 client_init_dispatch_15();
2085 }
2086
2087 /* client specific fatal cleanup */
2088 void
2089 cleanup_exit(int i)
2090 {
2091         leave_raw_mode();
2092         leave_non_blocking();
2093         if (options.control_path != NULL && control_fd != -1)
2094                 unlink(options.control_path);
2095         _exit(i);
2096 }