crypto/openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.236 2011/06/22 22:08:42 djm Exp $ */
   2 /* $FreeBSD$ */
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * The main loop for the interactive session (client side).
   8  *
   9  * As far as I am concerned, the code I have written for this software
  10  * can be used freely for any purpose.  Any derived versions of this
  11  * software must be clearly marked as such, and if the derived work is
  12  * incompatible with the protocol description in the RFC file, it must be
  13  * called by a name other than "ssh" or "Secure Shell".
  14  *
  15  *
  16  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions
  20  * are met:
  21  * 1. Redistributions of source code must retain the above copyright
  22  *    notice, this list of conditions and the following disclaimer.
  23  * 2. Redistributions in binary form must reproduce the above copyright
  24  *    notice, this list of conditions and the following disclaimer in the
  25  *    documentation and/or other materials provided with the distribution.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  28  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  29  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  30  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  31  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  32  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  33  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  34  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  36  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37  *
  38  *
  39  * SSH2 support added by Markus Friedl.
  40  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  61  */
  62
  63 #include "includes.h"
  64
  65 #include <sys/types.h>
  66 #include <sys/ioctl.h>
  67 #include <sys/param.h>
  68 #ifdef HAVE_SYS_STAT_H
  69 # include <sys/stat.h>
  70 #endif
  71 #ifdef HAVE_SYS_TIME_H
  72 # include <sys/time.h>
  73 #endif
  74 #include <sys/socket.h>
  75
  76 #include <ctype.h>
  77 #include <errno.h>
  78 #ifdef HAVE_PATHS_H
  79 #include <paths.h>
  80 #endif
  81 #include <signal.h>
  82 #include <stdarg.h>
  83 #include <stdio.h>
  84 #include <stdlib.h>
  85 #include <string.h>
  86 #include <termios.h>
  87 #include <pwd.h>
  88 #include <unistd.h>
  89
  90 #include "openbsd-compat/sys-queue.h"
  91 #include "xmalloc.h"
  92 #include "ssh.h"
  93 #include "ssh1.h"
  94 #include "ssh2.h"
  95 #include "packet.h"
  96 #include "buffer.h"
  97 #include "compat.h"
  98 #include "channels.h"
  99 #include "dispatch.h"
 100 #include "key.h"
 101 #include "cipher.h"
 102 #include "kex.h"
 103 #include "log.h"
 104 #include "readconf.h"
 105 #include "clientloop.h"
 106 #include "sshconnect.h"
 107 #include "authfd.h"
 108 #include "atomicio.h"
 109 #include "sshpty.h"
 110 #include "misc.h"
 111 #include "match.h"
 112 #include "msg.h"
 113 #include "roaming.h"
 114
 115 /* import options */
 116 extern Options options;
 117
 118 /* Flag indicating that stdin should be redirected from /dev/null. */
 119 extern int stdin_null_flag;
 120
 121 /* Flag indicating that no shell has been requested */
 122 extern int no_shell_flag;
 123
 124 /* Control socket */
 125 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
 126
 127 /*
 128  * Name of the host we are connecting to.  This is the name given on the
 129  * command line, or the HostName specified for the user-supplied name in a
 130  * configuration file.
 131  */
 132 extern char *host;
 133
 134 /*
 135  * Flag to indicate that we have received a window change signal which has
 136  * not yet been processed.  This will cause a message indicating the new
 137  * window size to be sent to the server a little later.  This is volatile
 138  * because this is updated in a signal handler.
 139  */
 140 static volatile sig_atomic_t received_window_change_signal = 0;
 141 static volatile sig_atomic_t received_signal = 0;
 142
 143 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 144 static int in_non_blocking_mode = 0;
 145
 146 /* Time when backgrounded control master using ControlPersist should exit */
 147 static time_t control_persist_exit_time = 0;
 148
 149 /* Common data for the client loop code. */
 150 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 151 static int escape_char1;        /* Escape character. (proto1 only) */
 152 static int escape_pending1;     /* Last character was an escape (proto1 only) */
 153 static int last_was_cr;         /* Last character was a newline. */
 154 static int exit_status;         /* Used to store the command exit status. */
 155 static int stdin_eof;           /* EOF has been encountered on stderr. */
 156 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 157 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 158 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 159 static u_int buffer_high;       /* Soft max buffer size. */
 160 static int connection_in;       /* Connection to server (input). */
 161 static int connection_out;      /* Connection to server (output). */
 162 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 163 static int session_closed;      /* In SSH2: login session closed. */
 164 static int x11_refuse_time;     /* If >0, refuse x11 opens after this time. */
 165
 166 static void client_init_dispatch(void);
 167 int     session_ident = -1;
 168
 169 int     session_resumed = 0;
 170
 171 /* Track escape per proto2 channel */
 172 struct escape_filter_ctx {
 173         int escape_pending;
 174         int escape_char;
 175 };
 176
 177 /* Context for channel confirmation replies */
 178 struct channel_reply_ctx {
 179         const char *request_type;
 180         int id;
 181         enum confirm_action action;
 182 };
 183
 184 /* Global request success/failure callbacks */
 185 struct global_confirm {
 186         TAILQ_ENTRY(global_confirm) entry;
 187         global_confirm_cb *cb;
 188         void *ctx;
 189         int ref_count;
 190 };
 191 TAILQ_HEAD(global_confirms, global_confirm);
 192 static struct global_confirms global_confirms =
 193     TAILQ_HEAD_INITIALIZER(global_confirms);
 194
 195 /*XXX*/
 196 extern Kex *xxx_kex;
 197
 198 void ssh_process_session2_setup(int, int, int, Buffer *);
 199
 200 /* Restores stdin to blocking mode. */
 201
 202 static void
 203 leave_non_blocking(void)
 204 {
 205         if (in_non_blocking_mode) {
 206                 unset_nonblock(fileno(stdin));
 207                 in_non_blocking_mode = 0;
 208         }
 209 }
 210
 211 /* Puts stdin terminal in non-blocking mode. */
 212
 213 static void
 214 enter_non_blocking(void)
 215 {
 216         in_non_blocking_mode = 1;
 217         set_nonblock(fileno(stdin));
 218 }
 219
 220 /*
 221  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 222  * flag indicating that the window has changed.
 223  */
 224 /*ARGSUSED */
 225 static void
 226 window_change_handler(int sig)
 227 {
 228         received_window_change_signal = 1;
 229         signal(SIGWINCH, window_change_handler);
 230 }
 231
 232 /*
 233  * Signal handler for signals that cause the program to terminate.  These
 234  * signals must be trapped to restore terminal modes.
 235  */
 236 /*ARGSUSED */
 237 static void
 238 signal_handler(int sig)
 239 {
 240         received_signal = sig;
 241         quit_pending = 1;
 242 }
 243
 244 /*
 245  * Returns current time in seconds from Jan 1, 1970 with the maximum
 246  * available resolution.
 247  */
 248
 249 static double
 250 get_current_time(void)
 251 {
 252         struct timeval tv;
 253         gettimeofday(&tv, NULL);
 254         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 255 }
 256
 257 /*
 258  * Sets control_persist_exit_time to the absolute time when the
 259  * backgrounded control master should exit due to expiry of the
 260  * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
 261  * control master process, or if there is no ControlPersist timeout.
 262  */
 263 static void
 264 set_control_persist_exit_time(void)
 265 {
 266         if (muxserver_sock == -1 || !options.control_persist
 267             || options.control_persist_timeout == 0) {
 268                 /* not using a ControlPersist timeout */
 269                 control_persist_exit_time = 0;
 270         } else if (channel_still_open()) {
 271                 /* some client connections are still open */
 272                 if (control_persist_exit_time > 0)
 273                         debug2("%s: cancel scheduled exit", __func__);
 274                 control_persist_exit_time = 0;
 275         } else if (control_persist_exit_time <= 0) {
 276                 /* a client connection has recently closed */
 277                 control_persist_exit_time = time(NULL) +
 278                         (time_t)options.control_persist_timeout;
 279                 debug2("%s: schedule exit in %d seconds", __func__,
 280                     options.control_persist_timeout);
 281         }
 282         /* else we are already counting down to the timeout */
 283 }
 284
 285 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 286 void
 287 client_x11_get_proto(const char *display, const char *xauth_path,
 288     u_int trusted, u_int timeout, char **_proto, char **_data)
 289 {
 290         char cmd[1024];
 291         char line[512];
 292         char xdisplay[512];
 293         static char proto[512], data[512];
 294         FILE *f;
 295         int got_data = 0, generated = 0, do_unlink = 0, i;
 296         char *xauthdir, *xauthfile;
 297         struct stat st;
 298         u_int now;
 299
 300         xauthdir = xauthfile = NULL;
 301         *_proto = proto;
 302         *_data = data;
 303         proto[0] = data[0] = '\0';
 304
 305         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 306                 debug("No xauth program.");
 307         } else {
 308                 if (display == NULL) {
 309                         debug("x11_get_proto: DISPLAY not set");
 310                         return;
 311                 }
 312                 /*
 313                  * Handle FamilyLocal case where $DISPLAY does
 314                  * not match an authorization entry.  For this we
 315                  * just try "xauth list unix:displaynum.screennum".
 316                  * XXX: "localhost" match to determine FamilyLocal
 317                  *      is not perfect.
 318                  */
 319                 if (strncmp(display, "localhost:", 10) == 0) {
 320                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 321                             display + 10);
 322                         display = xdisplay;
 323                 }
 324                 if (trusted == 0) {
 325                         xauthdir = xmalloc(MAXPATHLEN);
 326                         xauthfile = xmalloc(MAXPATHLEN);
 327                         mktemp_proto(xauthdir, MAXPATHLEN);
 328                         if (mkdtemp(xauthdir) != NULL) {
 329                                 do_unlink = 1;
 330                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 331                                     xauthdir);
 332                                 snprintf(cmd, sizeof(cmd),
 333                                     "%s -f %s generate %s " SSH_X11_PROTO
 334                                     " untrusted timeout %u 2>" _PATH_DEVNULL,
 335                                     xauth_path, xauthfile, display, timeout);
 336                                 debug2("x11_get_proto: %s", cmd);
 337                                 if (system(cmd) == 0)
 338                                         generated = 1;
 339                                 if (x11_refuse_time == 0) {
 340                                         now = time(NULL) + 1;
 341                                         if (UINT_MAX - timeout < now)
 342                                                 x11_refuse_time = UINT_MAX;
 343                                         else
 344                                                 x11_refuse_time = now + timeout;
 345                                 }
 346                         }
 347                 }
 348
 349                 /*
 350                  * When in untrusted mode, we read the cookie only if it was
 351                  * successfully generated as an untrusted one in the step
 352                  * above.
 353                  */
 354                 if (trusted || generated) {
 355                         snprintf(cmd, sizeof(cmd),
 356                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 357                             xauth_path,
 358                             generated ? "-f " : "" ,
 359                             generated ? xauthfile : "",
 360                             display);
 361                         debug2("x11_get_proto: %s", cmd);
 362                         f = popen(cmd, "r");
 363                         if (f && fgets(line, sizeof(line), f) &&
 364                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 365                                 got_data = 1;
 366                         if (f)
 367                                 pclose(f);
 368                 } else
 369                         error("Warning: untrusted X11 forwarding setup failed: "
 370                             "xauth key data not generated");
 371         }
 372
 373         if (do_unlink) {
 374                 unlink(xauthfile);
 375                 rmdir(xauthdir);
 376         }
 377         if (xauthdir)
 378                 xfree(xauthdir);
 379         if (xauthfile)
 380                 xfree(xauthfile);
 381
 382         /*
 383          * If we didn't get authentication data, just make up some
 384          * data.  The forwarding code will check the validity of the
 385          * response anyway, and substitute this data.  The X11
 386          * server, however, will ignore this fake data and use
 387          * whatever authentication mechanisms it was using otherwise
 388          * for the local connection.
 389          */
 390         if (!got_data) {
 391                 u_int32_t rnd = 0;
 392
 393                 logit("Warning: No xauth data; "
 394                     "using fake authentication data for X11 forwarding.");
 395                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 396                 for (i = 0; i < 16; i++) {
 397                         if (i % 4 == 0)
 398                                 rnd = arc4random();
 399                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 400                             rnd & 0xff);
 401                         rnd >>= 8;
 402                 }
 403         }
 404 }
 405
 406 /*
 407  * This is called when the interactive is entered.  This checks if there is
 408  * an EOF coming on stdin.  We must check this explicitly, as select() does
 409  * not appear to wake up when redirecting from /dev/null.
 410  */
 411
 412 static void
 413 client_check_initial_eof_on_stdin(void)
 414 {
 415         int len;
 416         char buf[1];
 417
 418         /*
 419          * If standard input is to be "redirected from /dev/null", we simply
 420          * mark that we have seen an EOF and send an EOF message to the
 421          * server. Otherwise, we try to read a single character; it appears
 422          * that for some files, such /dev/null, select() never wakes up for
 423          * read for this descriptor, which means that we never get EOF.  This
 424          * way we will get the EOF if stdin comes from /dev/null or similar.
 425          */
 426         if (stdin_null_flag) {
 427                 /* Fake EOF on stdin. */
 428                 debug("Sending eof.");
 429                 stdin_eof = 1;
 430                 packet_start(SSH_CMSG_EOF);
 431                 packet_send();
 432         } else {
 433                 enter_non_blocking();
 434
 435                 /* Check for immediate EOF on stdin. */
 436                 len = read(fileno(stdin), buf, 1);
 437                 if (len == 0) {
 438                         /*
 439                          * EOF.  Record that we have seen it and send
 440                          * EOF to server.
 441                          */
 442                         debug("Sending eof.");
 443                         stdin_eof = 1;
 444                         packet_start(SSH_CMSG_EOF);
 445                         packet_send();
 446                 } else if (len > 0) {
 447                         /*
 448                          * Got data.  We must store the data in the buffer,
 449                          * and also process it as an escape character if
 450                          * appropriate.
 451                          */
 452                         if ((u_char) buf[0] == escape_char1)
 453                                 escape_pending1 = 1;
 454                         else
 455                                 buffer_append(&stdin_buffer, buf, 1);
 456                 }
 457                 leave_non_blocking();
 458         }
 459 }
 460
 461
 462 /*
 463  * Make packets from buffered stdin data, and buffer them for sending to the
 464  * connection.
 465  */
 466
 467 static void
 468 client_make_packets_from_stdin_data(void)
 469 {
 470         u_int len;
 471
 472         /* Send buffered stdin data to the server. */
 473         while (buffer_len(&stdin_buffer) > 0 &&
 474             packet_not_very_much_data_to_write()) {
 475                 len = buffer_len(&stdin_buffer);
 476                 /* Keep the packets at reasonable size. */
 477                 if (len > packet_get_maxsize())
 478                         len = packet_get_maxsize();
 479                 packet_start(SSH_CMSG_STDIN_DATA);
 480                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 481                 packet_send();
 482                 buffer_consume(&stdin_buffer, len);
 483                 /* If we have a pending EOF, send it now. */
 484                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 485                         packet_start(SSH_CMSG_EOF);
 486                         packet_send();
 487                 }
 488         }
 489 }
 490
 491 /*
 492  * Checks if the client window has changed, and sends a packet about it to
 493  * the server if so.  The actual change is detected elsewhere (by a software
 494  * interrupt on Unix); this just checks the flag and sends a message if
 495  * appropriate.
 496  */
 497
 498 static void
 499 client_check_window_change(void)
 500 {
 501         struct winsize ws;
 502
 503         if (! received_window_change_signal)
 504                 return;
 505         /** XXX race */
 506         received_window_change_signal = 0;
 507
 508         debug2("client_check_window_change: changed");
 509
 510         if (compat20) {
 511                 channel_send_window_changes();
 512         } else {
 513                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 514                         return;
 515                 packet_start(SSH_CMSG_WINDOW_SIZE);
 516                 packet_put_int((u_int)ws.ws_row);
 517                 packet_put_int((u_int)ws.ws_col);
 518                 packet_put_int((u_int)ws.ws_xpixel);
 519                 packet_put_int((u_int)ws.ws_ypixel);
 520                 packet_send();
 521         }
 522 }
 523
 524 static void
 525 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 526 {
 527         struct global_confirm *gc;
 528
 529         if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
 530                 return;
 531         if (gc->cb != NULL)
 532                 gc->cb(type, seq, gc->ctx);
 533         if (--gc->ref_count <= 0) {
 534                 TAILQ_REMOVE(&global_confirms, gc, entry);
 535                 bzero(gc, sizeof(*gc));
 536                 xfree(gc);
 537         }
 538
 539         packet_set_alive_timeouts(0);
 540 }
 541
 542 static void
 543 server_alive_check(void)
 544 {
 545         if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
 546                 logit("Timeout, server %s not responding.", host);
 547                 cleanup_exit(255);
 548         }
 549         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 550         packet_put_cstring("keepalive@openssh.com");
 551         packet_put_char(1);     /* boolean: want reply */
 552         packet_send();
 553         /* Insert an empty placeholder to maintain ordering */
 554         client_register_global_confirm(NULL, NULL);
 555 }
 556
 557 /*
 558  * Waits until the client can do something (some data becomes available on
 559  * one of the file descriptors).
 560  */
 561 static void
 562 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 563     int *maxfdp, u_int *nallocp, int rekeying)
 564 {
 565         struct timeval tv, *tvp;
 566         int timeout_secs;
 567         int ret;
 568
 569         /* Add any selections by the channel mechanism. */
 570         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 571
 572         if (!compat20) {
 573                 /* Read from the connection, unless our buffers are full. */
 574                 if (buffer_len(&stdout_buffer) < buffer_high &&
 575                     buffer_len(&stderr_buffer) < buffer_high &&
 576                     channel_not_very_much_buffered_data())
 577                         FD_SET(connection_in, *readsetp);
 578                 /*
 579                  * Read from stdin, unless we have seen EOF or have very much
 580                  * buffered data to send to the server.
 581                  */
 582                 if (!stdin_eof && packet_not_very_much_data_to_write())
 583                         FD_SET(fileno(stdin), *readsetp);
 584
 585                 /* Select stdout/stderr if have data in buffer. */
 586                 if (buffer_len(&stdout_buffer) > 0)
 587                         FD_SET(fileno(stdout), *writesetp);
 588                 if (buffer_len(&stderr_buffer) > 0)
 589                         FD_SET(fileno(stderr), *writesetp);
 590         } else {
 591                 /* channel_prepare_select could have closed the last channel */
 592                 if (session_closed && !channel_still_open() &&
 593                     !packet_have_data_to_write()) {
 594                         /* clear mask since we did not call select() */
 595                         memset(*readsetp, 0, *nallocp);
 596                         memset(*writesetp, 0, *nallocp);
 597                         return;
 598                 } else {
 599                         FD_SET(connection_in, *readsetp);
 600                 }
 601         }
 602
 603         /* Select server connection if have data to write to the server. */
 604         if (packet_have_data_to_write())
 605                 FD_SET(connection_out, *writesetp);
 606
 607         /*
 608          * Wait for something to happen.  This will suspend the process until
 609          * some selected descriptor can be read, written, or has some other
 610          * event pending, or a timeout expires.
 611          */
 612
 613         timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
 614         if (options.server_alive_interval > 0 && compat20)
 615                 timeout_secs = options.server_alive_interval;
 616         set_control_persist_exit_time();
 617         if (control_persist_exit_time > 0) {
 618                 timeout_secs = MIN(timeout_secs,
 619                         control_persist_exit_time - time(NULL));
 620                 if (timeout_secs < 0)
 621                         timeout_secs = 0;
 622         }
 623         if (timeout_secs == INT_MAX)
 624                 tvp = NULL;
 625         else {
 626                 tv.tv_sec = timeout_secs;
 627                 tv.tv_usec = 0;
 628                 tvp = &tv;
 629         }
 630
 631         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 632         if (ret < 0) {
 633                 char buf[100];
 634
 635                 /*
 636                  * We have to clear the select masks, because we return.
 637                  * We have to return, because the mainloop checks for the flags
 638                  * set by the signal handlers.
 639                  */
 640                 memset(*readsetp, 0, *nallocp);
 641                 memset(*writesetp, 0, *nallocp);
 642
 643                 if (errno == EINTR)
 644                         return;
 645                 /* Note: we might still have data in the buffers. */
 646                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 647                 buffer_append(&stderr_buffer, buf, strlen(buf));
 648                 quit_pending = 1;
 649         } else if (ret == 0)
 650                 server_alive_check();
 651 }
 652
 653 static void
 654 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 655 {
 656         /* Flush stdout and stderr buffers. */
 657         if (buffer_len(bout) > 0)
 658                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
 659                     buffer_len(bout));
 660         if (buffer_len(berr) > 0)
 661                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
 662                     buffer_len(berr));
 663
 664         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 665
 666         /*
 667          * Free (and clear) the buffer to reduce the amount of data that gets
 668          * written to swap.
 669          */
 670         buffer_free(bin);
 671         buffer_free(bout);
 672         buffer_free(berr);
 673
 674         /* Send the suspend signal to the program itself. */
 675         kill(getpid(), SIGTSTP);
 676
 677         /* Reset window sizes in case they have changed */
 678         received_window_change_signal = 1;
 679
 680         /* OK, we have been continued by the user. Reinitialize buffers. */
 681         buffer_init(bin);
 682         buffer_init(bout);
 683         buffer_init(berr);
 684
 685         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 686 }
 687
 688 static void
 689 client_process_net_input(fd_set *readset)
 690 {
 691         int len, cont = 0;
 692         char buf[SSH_IOBUFSZ];
 693
 694         /*
 695          * Read input from the server, and add any such data to the buffer of
 696          * the packet subsystem.
 697          */
 698         if (FD_ISSET(connection_in, readset)) {
 699                 /* Read as much as possible. */
 700                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 701                 if (len == 0 && cont == 0) {
 702                         /*
 703                          * Received EOF.  The remote host has closed the
 704                          * connection.
 705                          */
 706                         snprintf(buf, sizeof buf,
 707                             "Connection to %.300s closed by remote host.\r\n",
 708                             host);
 709                         buffer_append(&stderr_buffer, buf, strlen(buf));
 710                         quit_pending = 1;
 711                         return;
 712                 }
 713                 /*
 714                  * There is a kernel bug on Solaris that causes select to
 715                  * sometimes wake up even though there is no data available.
 716                  */
 717                 if (len < 0 &&
 718                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 719                         len = 0;
 720
 721                 if (len < 0) {
 722                         /*
 723                          * An error has encountered.  Perhaps there is a
 724                          * network problem.
 725                          */
 726                         snprintf(buf, sizeof buf,
 727                             "Read from remote host %.300s: %.100s\r\n",
 728                             host, strerror(errno));
 729                         buffer_append(&stderr_buffer, buf, strlen(buf));
 730                         quit_pending = 1;
 731                         return;
 732                 }
 733                 packet_process_incoming(buf, len);
 734         }
 735 }
 736
 737 static void
 738 client_status_confirm(int type, Channel *c, void *ctx)
 739 {
 740         struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
 741         char errmsg[256];
 742         int tochan;
 743
 744         /*
 745          * If a TTY was explicitly requested, then a failure to allocate
 746          * one is fatal.
 747          */
 748         if (cr->action == CONFIRM_TTY &&
 749             (options.request_tty == REQUEST_TTY_FORCE ||
 750             options.request_tty == REQUEST_TTY_YES))
 751                 cr->action = CONFIRM_CLOSE;
 752
 753         /* XXX supress on mux _client_ quietmode */
 754         tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
 755             c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
 756
 757         if (type == SSH2_MSG_CHANNEL_SUCCESS) {
 758                 debug2("%s request accepted on channel %d",
 759                     cr->request_type, c->self);
 760         } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 761                 if (tochan) {
 762                         snprintf(errmsg, sizeof(errmsg),
 763                             "%s request failed\r\n", cr->request_type);
 764                 } else {
 765                         snprintf(errmsg, sizeof(errmsg),
 766                             "%s request failed on channel %d",
 767                             cr->request_type, c->self);
 768                 }
 769                 /* If error occurred on primary session channel, then exit */
 770                 if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
 771                         fatal("%s", errmsg);
 772                 /*
 773                  * If error occurred on mux client, append to
 774                  * their stderr.
 775                  */
 776                 if (tochan) {
 777                         buffer_append(&c->extended, errmsg,
 778                             strlen(errmsg));
 779                 } else
 780                         error("%s", errmsg);
 781                 if (cr->action == CONFIRM_TTY) {
 782                         /*
 783                          * If a TTY allocation error occurred, then arrange
 784                          * for the correct TTY to leave raw mode.
 785                          */
 786                         if (c->self == session_ident)
 787                                 leave_raw_mode(0);
 788                         else
 789                                 mux_tty_alloc_failed(c);
 790                 } else if (cr->action == CONFIRM_CLOSE) {
 791                         chan_read_failed(c);
 792                         chan_write_failed(c);
 793                 }
 794         }
 795         xfree(cr);
 796 }
 797
 798 static void
 799 client_abandon_status_confirm(Channel *c, void *ctx)
 800 {
 801         xfree(ctx);
 802 }
 803
 804 void
 805 client_expect_confirm(int id, const char *request,
 806     enum confirm_action action)
 807 {
 808         struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
 809
 810         cr->request_type = request;
 811         cr->action = action;
 812
 813         channel_register_status_confirm(id, client_status_confirm,
 814             client_abandon_status_confirm, cr);
 815 }
 816
 817 void
 818 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
 819 {
 820         struct global_confirm *gc, *last_gc;
 821
 822         /* Coalesce identical callbacks */
 823         last_gc = TAILQ_LAST(&global_confirms, global_confirms);
 824         if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
 825                 if (++last_gc->ref_count >= INT_MAX)
 826                         fatal("%s: last_gc->ref_count = %d",
 827                             __func__, last_gc->ref_count);
 828                 return;
 829         }
 830
 831         gc = xmalloc(sizeof(*gc));
 832         gc->cb = cb;
 833         gc->ctx = ctx;
 834         gc->ref_count = 1;
 835         TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
 836 }
 837
 838 static void
 839 process_cmdline(void)
 840 {
 841         void (*handler)(int);
 842         char *s, *cmd, *cancel_host;
 843         int delete = 0;
 844         int local = 0, remote = 0, dynamic = 0;
 845         int cancel_port;
 846         Forward fwd;
 847
 848         bzero(&fwd, sizeof(fwd));
 849         fwd.listen_host = fwd.connect_host = NULL;
 850
 851         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 852         handler = signal(SIGINT, SIG_IGN);
 853         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 854         if (s == NULL)
 855                 goto out;
 856         while (isspace(*s))
 857                 s++;
 858         if (*s == '-')
 859                 s++;    /* Skip cmdline '-', if any */
 860         if (*s == '\0')
 861                 goto out;
 862
 863         if (*s == 'h' || *s == 'H' || *s == '?') {
 864                 logit("Commands:");
 865                 logit("      -L[bind_address:]port:host:hostport    "
 866                     "Request local forward");
 867                 logit("      -R[bind_address:]port:host:hostport    "
 868                     "Request remote forward");
 869                 logit("      -D[bind_address:]port                  "
 870                     "Request dynamic forward");
 871                 logit("      -KR[bind_address:]port                 "
 872                     "Cancel remote forward");
 873                 if (!options.permit_local_command)
 874                         goto out;
 875                 logit("      !args                                  "
 876                     "Execute local command");
 877                 goto out;
 878         }
 879
 880         if (*s == '!' && options.permit_local_command) {
 881                 s++;
 882                 ssh_local_cmd(s);
 883                 goto out;
 884         }
 885
 886         if (*s == 'K') {
 887                 delete = 1;
 888                 s++;
 889         }
 890         if (*s == 'L')
 891                 local = 1;
 892         else if (*s == 'R')
 893                 remote = 1;
 894         else if (*s == 'D')
 895                 dynamic = 1;
 896         else {
 897                 logit("Invalid command.");
 898                 goto out;
 899         }
 900
 901         if ((local || dynamic) && delete) {
 902                 logit("Not supported.");
 903                 goto out;
 904         }
 905         if (remote && delete && !compat20) {
 906                 logit("Not supported for SSH protocol version 1.");
 907                 goto out;
 908         }
 909
 910         while (isspace(*++s))
 911                 ;
 912
 913         /* XXX update list of forwards in options */
 914         if (delete) {
 915                 cancel_port = 0;
 916                 cancel_host = hpdelim(&s);      /* may be NULL */
 917                 if (s != NULL) {
 918                         cancel_port = a2port(s);
 919                         cancel_host = cleanhostname(cancel_host);
 920                 } else {
 921                         cancel_port = a2port(cancel_host);
 922                         cancel_host = NULL;
 923                 }
 924                 if (cancel_port <= 0) {
 925                         logit("Bad forwarding close port");
 926                         goto out;
 927                 }
 928                 channel_request_rforward_cancel(cancel_host, cancel_port);
 929         } else {
 930                 if (!parse_forward(&fwd, s, dynamic, remote)) {
 931                         logit("Bad forwarding specification.");
 932                         goto out;
 933                 }
 934                 if (local || dynamic) {
 935                         if (channel_setup_local_fwd_listener(fwd.listen_host,
 936                             fwd.listen_port, fwd.connect_host,
 937                             fwd.connect_port, options.gateway_ports) < 0) {
 938                                 logit("Port forwarding failed.");
 939                                 goto out;
 940                         }
 941                 } else {
 942                         if (channel_request_remote_forwarding(fwd.listen_host,
 943                             fwd.listen_port, fwd.connect_host,
 944                             fwd.connect_port) < 0) {
 945                                 logit("Port forwarding failed.");
 946                                 goto out;
 947                         }
 948                 }
 949
 950                 logit("Forwarding port.");
 951         }
 952
 953 out:
 954         signal(SIGINT, handler);
 955         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 956         if (cmd)
 957                 xfree(cmd);
 958         if (fwd.listen_host != NULL)
 959                 xfree(fwd.listen_host);
 960         if (fwd.connect_host != NULL)
 961                 xfree(fwd.connect_host);
 962 }
 963
 964 /*
 965  * Process the characters one by one, call with c==NULL for proto1 case.
 966  */
 967 static int
 968 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
 969     char *buf, int len)
 970 {
 971         char string[1024];
 972         pid_t pid;
 973         int bytes = 0;
 974         u_int i;
 975         u_char ch;
 976         char *s;
 977         int *escape_pendingp, escape_char;
 978         struct escape_filter_ctx *efc;
 979
 980         if (c == NULL) {
 981                 escape_pendingp = &escape_pending1;
 982                 escape_char = escape_char1;
 983         } else {
 984                 if (c->filter_ctx == NULL)
 985                         return 0;
 986                 efc = (struct escape_filter_ctx *)c->filter_ctx;
 987                 escape_pendingp = &efc->escape_pending;
 988                 escape_char = efc->escape_char;
 989         }
 990
 991         if (len <= 0)
 992                 return (0);
 993
 994         for (i = 0; i < (u_int)len; i++) {
 995                 /* Get one character at a time. */
 996                 ch = buf[i];
 997
 998                 if (*escape_pendingp) {
 999                         /* We have previously seen an escape character. */
1000                         /* Clear the flag now. */
1001                         *escape_pendingp = 0;
1002
1003                         /* Process the escaped character. */
1004                         switch (ch) {
1005                         case '.':
1006                                 /* Terminate the connection. */
1007                                 snprintf(string, sizeof string, "%c.\r\n",
1008                                     escape_char);
1009                                 buffer_append(berr, string, strlen(string));
1010
1011                                 if (c && c->ctl_chan != -1) {
1012                                         chan_read_failed(c);
1013                                         chan_write_failed(c);
1014                                         return 0;
1015                                 } else
1016                                         quit_pending = 1;
1017                                 return -1;
1018
1019                         case 'Z' - 64:
1020                                 /* XXX support this for mux clients */
1021                                 if (c && c->ctl_chan != -1) {
1022  noescape:
1023                                         snprintf(string, sizeof string,
1024                                             "%c%c escape not available to "
1025                                             "multiplexed sessions\r\n",
1026                                             escape_char, ch);
1027                                         buffer_append(berr, string,
1028                                             strlen(string));
1029                                         continue;
1030                                 }
1031                                 /* Suspend the program. Inform the user */
1032                                 snprintf(string, sizeof string,
1033                                     "%c^Z [suspend ssh]\r\n", escape_char);
1034                                 buffer_append(berr, string, strlen(string));
1035
1036                                 /* Restore terminal modes and suspend. */
1037                                 client_suspend_self(bin, bout, berr);
1038
1039                                 /* We have been continued. */
1040                                 continue;
1041
1042                         case 'B':
1043                                 if (compat20) {
1044                                         snprintf(string, sizeof string,
1045                                             "%cB\r\n", escape_char);
1046                                         buffer_append(berr, string,
1047                                             strlen(string));
1048                                         channel_request_start(session_ident,
1049                                             "break", 0);
1050                                         packet_put_int(1000);
1051                                         packet_send();
1052                                 }
1053                                 continue;
1054
1055                         case 'R':
1056                                 if (compat20) {
1057                                         if (datafellows & SSH_BUG_NOREKEY)
1058                                                 logit("Server does not "
1059                                                     "support re-keying");
1060                                         else
1061                                                 need_rekeying = 1;
1062                                 }
1063                                 continue;
1064
1065                         case '&':
1066                                 if (c && c->ctl_chan != -1)
1067                                         goto noescape;
1068                                 /*
1069                                  * Detach the program (continue to serve
1070                                  * connections, but put in background and no
1071                                  * more new connections).
1072                                  */
1073                                 /* Restore tty modes. */
1074                                 leave_raw_mode(
1075                                     options.request_tty == REQUEST_TTY_FORCE);
1076
1077                                 /* Stop listening for new connections. */
1078                                 channel_stop_listening();
1079
1080                                 snprintf(string, sizeof string,
1081                                     "%c& [backgrounded]\n", escape_char);
1082                                 buffer_append(berr, string, strlen(string));
1083
1084                                 /* Fork into background. */
1085                                 pid = fork();
1086                                 if (pid < 0) {
1087                                         error("fork: %.100s", strerror(errno));
1088                                         continue;
1089                                 }
1090                                 if (pid != 0) { /* This is the parent. */
1091                                         /* The parent just exits. */
1092                                         exit(0);
1093                                 }
1094                                 /* The child continues serving connections. */
1095                                 if (compat20) {
1096                                         buffer_append(bin, "\004", 1);
1097                                         /* fake EOF on stdin */
1098                                         return -1;
1099                                 } else if (!stdin_eof) {
1100                                         /*
1101                                          * Sending SSH_CMSG_EOF alone does not
1102                                          * always appear to be enough.  So we
1103                                          * try to send an EOF character first.
1104                                          */
1105                                         packet_start(SSH_CMSG_STDIN_DATA);
1106                                         packet_put_string("\004", 1);
1107                                         packet_send();
1108                                         /* Close stdin. */
1109                                         stdin_eof = 1;
1110                                         if (buffer_len(bin) == 0) {
1111                                                 packet_start(SSH_CMSG_EOF);
1112                                                 packet_send();
1113                                         }
1114                                 }
1115                                 continue;
1116
1117                         case '?':
1118                                 if (c && c->ctl_chan != -1) {
1119                                         snprintf(string, sizeof string,
1120 "%c?\r\n\
1121 Supported escape sequences:\r\n\
1122   %c.  - terminate session\r\n\
1123   %cB  - send a BREAK to the remote system\r\n\
1124   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1125   %c#  - list forwarded connections\r\n\
1126   %c?  - this message\r\n\
1127   %c%c  - send the escape character by typing it twice\r\n\
1128 (Note that escapes are only recognized immediately after newline.)\r\n",
1129                                             escape_char, escape_char,
1130                                             escape_char, escape_char,
1131                                             escape_char, escape_char,
1132                                             escape_char, escape_char);
1133                                 } else {
1134                                         snprintf(string, sizeof string,
1135 "%c?\r\n\
1136 Supported escape sequences:\r\n\
1137   %c.  - terminate connection (and any multiplexed sessions)\r\n\
1138   %cB  - send a BREAK to the remote system\r\n\
1139   %cC  - open a command line\r\n\
1140   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1141   %c^Z - suspend ssh\r\n\
1142   %c#  - list forwarded connections\r\n\
1143   %c&  - background ssh (when waiting for connections to terminate)\r\n\
1144   %c?  - this message\r\n\
1145   %c%c  - send the escape character by typing it twice\r\n\
1146 (Note that escapes are only recognized immediately after newline.)\r\n",
1147                                             escape_char, escape_char,
1148                                             escape_char, escape_char,
1149                                             escape_char, escape_char,
1150                                             escape_char, escape_char,
1151                                             escape_char, escape_char,
1152                                             escape_char);
1153                                 }
1154                                 buffer_append(berr, string, strlen(string));
1155                                 continue;
1156
1157                         case '#':
1158                                 snprintf(string, sizeof string, "%c#\r\n",
1159                                     escape_char);
1160                                 buffer_append(berr, string, strlen(string));
1161                                 s = channel_open_message();
1162                                 buffer_append(berr, s, strlen(s));
1163                                 xfree(s);
1164                                 continue;
1165
1166                         case 'C':
1167                                 if (c && c->ctl_chan != -1)
1168                                         goto noescape;
1169                                 process_cmdline();
1170                                 continue;
1171
1172                         default:
1173                                 if (ch != escape_char) {
1174                                         buffer_put_char(bin, escape_char);
1175                                         bytes++;
1176                                 }
1177                                 /* Escaped characters fall through here */
1178                                 break;
1179                         }
1180                 } else {
1181                         /*
1182                          * The previous character was not an escape char.
1183                          * Check if this is an escape.
1184                          */
1185                         if (last_was_cr && ch == escape_char) {
1186                                 /*
1187                                  * It is. Set the flag and continue to
1188                                  * next character.
1189                                  */
1190                                 *escape_pendingp = 1;
1191                                 continue;
1192                         }
1193                 }
1194
1195                 /*
1196                  * Normal character.  Record whether it was a newline,
1197                  * and append it to the buffer.
1198                  */
1199                 last_was_cr = (ch == '\r' || ch == '\n');
1200                 buffer_put_char(bin, ch);
1201                 bytes++;
1202         }
1203         return bytes;
1204 }
1205
1206 static void
1207 client_process_input(fd_set *readset)
1208 {
1209         int len;
1210         char buf[SSH_IOBUFSZ];
1211
1212         /* Read input from stdin. */
1213         if (FD_ISSET(fileno(stdin), readset)) {
1214                 /* Read as much as possible. */
1215                 len = read(fileno(stdin), buf, sizeof(buf));
1216                 if (len < 0 &&
1217                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1218                         return;         /* we'll try again later */
1219                 if (len <= 0) {
1220                         /*
1221                          * Received EOF or error.  They are treated
1222                          * similarly, except that an error message is printed
1223                          * if it was an error condition.
1224                          */
1225                         if (len < 0) {
1226                                 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1227                                     strerror(errno));
1228                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1229                         }
1230                         /* Mark that we have seen EOF. */
1231                         stdin_eof = 1;
1232                         /*
1233                          * Send an EOF message to the server unless there is
1234                          * data in the buffer.  If there is data in the
1235                          * buffer, no message will be sent now.  Code
1236                          * elsewhere will send the EOF when the buffer
1237                          * becomes empty if stdin_eof is set.
1238                          */
1239                         if (buffer_len(&stdin_buffer) == 0) {
1240                                 packet_start(SSH_CMSG_EOF);
1241                                 packet_send();
1242                         }
1243                 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1244                         /*
1245                          * Normal successful read, and no escape character.
1246                          * Just append the data to buffer.
1247                          */
1248                         buffer_append(&stdin_buffer, buf, len);
1249                 } else {
1250                         /*
1251                          * Normal, successful read.  But we have an escape
1252                          * character and have to process the characters one
1253                          * by one.
1254                          */
1255                         if (process_escapes(NULL, &stdin_buffer,
1256                             &stdout_buffer, &stderr_buffer, buf, len) == -1)
1257                                 return;
1258                 }
1259         }
1260 }
1261
1262 static void
1263 client_process_output(fd_set *writeset)
1264 {
1265         int len;
1266         char buf[100];
1267
1268         /* Write buffered output to stdout. */
1269         if (FD_ISSET(fileno(stdout), writeset)) {
1270                 /* Write as much data as possible. */
1271                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1272                     buffer_len(&stdout_buffer));
1273                 if (len <= 0) {
1274                         if (errno == EINTR || errno == EAGAIN ||
1275                             errno == EWOULDBLOCK)
1276                                 len = 0;
1277                         else {
1278                                 /*
1279                                  * An error or EOF was encountered.  Put an
1280                                  * error message to stderr buffer.
1281                                  */
1282                                 snprintf(buf, sizeof buf,
1283                                     "write stdout: %.50s\r\n", strerror(errno));
1284                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1285                                 quit_pending = 1;
1286                                 return;
1287                         }
1288                 }
1289                 /* Consume printed data from the buffer. */
1290                 buffer_consume(&stdout_buffer, len);
1291         }
1292         /* Write buffered output to stderr. */
1293         if (FD_ISSET(fileno(stderr), writeset)) {
1294                 /* Write as much data as possible. */
1295                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1296                     buffer_len(&stderr_buffer));
1297                 if (len <= 0) {
1298                         if (errno == EINTR || errno == EAGAIN ||
1299                             errno == EWOULDBLOCK)
1300                                 len = 0;
1301                         else {
1302                                 /*
1303                                  * EOF or error, but can't even print
1304                                  * error message.
1305                                  */
1306                                 quit_pending = 1;
1307                                 return;
1308                         }
1309                 }
1310                 /* Consume printed characters from the buffer. */
1311                 buffer_consume(&stderr_buffer, len);
1312         }
1313 }
1314
1315 /*
1316  * Get packets from the connection input buffer, and process them as long as
1317  * there are packets available.
1318  *
1319  * Any unknown packets received during the actual
1320  * session cause the session to terminate.  This is
1321  * intended to make debugging easier since no
1322  * confirmations are sent.  Any compatible protocol
1323  * extensions must be negotiated during the
1324  * preparatory phase.
1325  */
1326
1327 static void
1328 client_process_buffered_input_packets(void)
1329 {
1330         dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1331             compat20 ? xxx_kex : NULL);
1332 }
1333
1334 /* scan buf[] for '~' before sending data to the peer */
1335
1336 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1337 void *
1338 client_new_escape_filter_ctx(int escape_char)
1339 {
1340         struct escape_filter_ctx *ret;
1341
1342         ret = xmalloc(sizeof(*ret));
1343         ret->escape_pending = 0;
1344         ret->escape_char = escape_char;
1345         return (void *)ret;
1346 }
1347
1348 /* Free the escape filter context on channel free */
1349 void
1350 client_filter_cleanup(int cid, void *ctx)
1351 {
1352         xfree(ctx);
1353 }
1354
1355 int
1356 client_simple_escape_filter(Channel *c, char *buf, int len)
1357 {
1358         if (c->extended_usage != CHAN_EXTENDED_WRITE)
1359                 return 0;
1360
1361         return process_escapes(c, &c->input, &c->output, &c->extended,
1362             buf, len);
1363 }
1364
1365 static void
1366 client_channel_closed(int id, void *arg)
1367 {
1368         channel_cancel_cleanup(id);
1369         session_closed = 1;
1370         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1371 }
1372
1373 /*
1374  * Implements the interactive session with the server.  This is called after
1375  * the user has been authenticated, and a command has been started on the
1376  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1377  * used as an escape character for terminating or suspending the session.
1378  */
1379
1380 int
1381 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1382 {
1383         fd_set *readset = NULL, *writeset = NULL;
1384         double start_time, total_time;
1385         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1386         u_int64_t ibytes, obytes;
1387         u_int nalloc = 0;
1388         char buf[100];
1389
1390         debug("Entering interactive session.");
1391
1392         start_time = get_current_time();
1393
1394         /* Initialize variables. */
1395         escape_pending1 = 0;
1396         last_was_cr = 1;
1397         exit_status = -1;
1398         stdin_eof = 0;
1399         buffer_high = 64 * 1024;
1400         connection_in = packet_get_connection_in();
1401         connection_out = packet_get_connection_out();
1402         max_fd = MAX(connection_in, connection_out);
1403
1404         if (!compat20) {
1405                 /* enable nonblocking unless tty */
1406                 if (!isatty(fileno(stdin)))
1407                         set_nonblock(fileno(stdin));
1408                 if (!isatty(fileno(stdout)))
1409                         set_nonblock(fileno(stdout));
1410                 if (!isatty(fileno(stderr)))
1411                         set_nonblock(fileno(stderr));
1412                 max_fd = MAX(max_fd, fileno(stdin));
1413                 max_fd = MAX(max_fd, fileno(stdout));
1414                 max_fd = MAX(max_fd, fileno(stderr));
1415         }
1416         quit_pending = 0;
1417         escape_char1 = escape_char_arg;
1418
1419         /* Initialize buffers. */
1420         buffer_init(&stdin_buffer);
1421         buffer_init(&stdout_buffer);
1422         buffer_init(&stderr_buffer);
1423
1424         client_init_dispatch();
1425
1426         /*
1427          * Set signal handlers, (e.g. to restore non-blocking mode)
1428          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1429          */
1430         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1431                 signal(SIGHUP, signal_handler);
1432         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1433                 signal(SIGINT, signal_handler);
1434         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1435                 signal(SIGQUIT, signal_handler);
1436         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1437                 signal(SIGTERM, signal_handler);
1438         signal(SIGWINCH, window_change_handler);
1439
1440         if (have_pty)
1441                 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1442
1443         if (compat20) {
1444                 session_ident = ssh2_chan_id;
1445                 if (session_ident != -1) {
1446                         if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1447                                 channel_register_filter(session_ident,
1448                                     client_simple_escape_filter, NULL,
1449                                     client_filter_cleanup,
1450                                     client_new_escape_filter_ctx(
1451                                     escape_char_arg));
1452                         }
1453                         channel_register_cleanup(session_ident,
1454                             client_channel_closed, 0);
1455                 }
1456         } else {
1457                 /* Check if we should immediately send eof on stdin. */
1458                 client_check_initial_eof_on_stdin();
1459         }
1460
1461         /* Main loop of the client for the interactive session mode. */
1462         while (!quit_pending) {
1463
1464                 /* Process buffered packets sent by the server. */
1465                 client_process_buffered_input_packets();
1466
1467                 if (compat20 && session_closed && !channel_still_open())
1468                         break;
1469
1470                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1471
1472                 if (rekeying) {
1473                         debug("rekeying in progress");
1474                 } else {
1475                         /*
1476                          * Make packets of buffered stdin data, and buffer
1477                          * them for sending to the server.
1478                          */
1479                         if (!compat20)
1480                                 client_make_packets_from_stdin_data();
1481
1482                         /*
1483                          * Make packets from buffered channel data, and
1484                          * enqueue them for sending to the server.
1485                          */
1486                         if (packet_not_very_much_data_to_write())
1487                                 channel_output_poll();
1488
1489                         /*
1490                          * Check if the window size has changed, and buffer a
1491                          * message about it to the server if so.
1492                          */
1493                         client_check_window_change();
1494
1495                         if (quit_pending)
1496                                 break;
1497                 }
1498                 /*
1499                  * Wait until we have something to do (something becomes
1500                  * available on one of the descriptors).
1501                  */
1502                 max_fd2 = max_fd;
1503                 client_wait_until_can_do_something(&readset, &writeset,
1504                     &max_fd2, &nalloc, rekeying);
1505
1506                 if (quit_pending)
1507                         break;
1508
1509                 /* Do channel operations unless rekeying in progress. */
1510                 if (!rekeying) {
1511                         channel_after_select(readset, writeset);
1512                         if (need_rekeying || packet_need_rekeying()) {
1513                                 debug("need rekeying");
1514                                 xxx_kex->done = 0;
1515                                 kex_send_kexinit(xxx_kex);
1516                                 need_rekeying = 0;
1517                         }
1518                 }
1519
1520                 /* Buffer input from the connection.  */
1521                 client_process_net_input(readset);
1522
1523                 if (quit_pending)
1524                         break;
1525
1526                 if (!compat20) {
1527                         /* Buffer data from stdin */
1528                         client_process_input(readset);
1529                         /*
1530                          * Process output to stdout and stderr.  Output to
1531                          * the connection is processed elsewhere (above).
1532                          */
1533                         client_process_output(writeset);
1534                 }
1535
1536                 if (session_resumed) {
1537                         connection_in = packet_get_connection_in();
1538                         connection_out = packet_get_connection_out();
1539                         max_fd = MAX(max_fd, connection_out);
1540                         max_fd = MAX(max_fd, connection_in);
1541                         session_resumed = 0;
1542                 }
1543
1544                 /*
1545                  * Send as much buffered packet data as possible to the
1546                  * sender.
1547                  */
1548                 if (FD_ISSET(connection_out, writeset))
1549                         packet_write_poll();
1550
1551                 /*
1552                  * If we are a backgrounded control master, and the
1553                  * timeout has expired without any active client
1554                  * connections, then quit.
1555                  */
1556                 if (control_persist_exit_time > 0) {
1557                         if (time(NULL) >= control_persist_exit_time) {
1558                                 debug("ControlPersist timeout expired");
1559                                 break;
1560                         }
1561                 }
1562         }
1563         if (readset)
1564                 xfree(readset);
1565         if (writeset)
1566                 xfree(writeset);
1567
1568         /* Terminate the session. */
1569
1570         /* Stop watching for window change. */
1571         signal(SIGWINCH, SIG_DFL);
1572
1573         if (compat20) {
1574                 packet_start(SSH2_MSG_DISCONNECT);
1575                 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1576                 packet_put_cstring("disconnected by user");
1577                 packet_put_cstring(""); /* language tag */
1578                 packet_send();
1579                 packet_write_wait();
1580         }
1581
1582         channel_free_all();
1583
1584         if (have_pty)
1585                 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1586
1587         /* restore blocking io */
1588         if (!isatty(fileno(stdin)))
1589                 unset_nonblock(fileno(stdin));
1590         if (!isatty(fileno(stdout)))
1591                 unset_nonblock(fileno(stdout));
1592         if (!isatty(fileno(stderr)))
1593                 unset_nonblock(fileno(stderr));
1594
1595         /*
1596          * If there was no shell or command requested, there will be no remote
1597          * exit status to be returned.  In that case, clear error code if the
1598          * connection was deliberately terminated at this end.
1599          */
1600         if (no_shell_flag && received_signal == SIGTERM) {
1601                 received_signal = 0;
1602                 exit_status = 0;
1603         }
1604
1605         if (received_signal)
1606                 fatal("Killed by signal %d.", (int) received_signal);
1607
1608         /*
1609          * In interactive mode (with pseudo tty) display a message indicating
1610          * that the connection has been closed.
1611          */
1612         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1613                 snprintf(buf, sizeof buf,
1614                     "Connection to %.64s closed.\r\n", host);
1615                 buffer_append(&stderr_buffer, buf, strlen(buf));
1616         }
1617
1618         /* Output any buffered data for stdout. */
1619         if (buffer_len(&stdout_buffer) > 0) {
1620                 len = atomicio(vwrite, fileno(stdout),
1621                     buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer));
1622                 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer))
1623                         error("Write failed flushing stdout buffer.");
1624                 else
1625                         buffer_consume(&stdout_buffer, len);
1626         }
1627
1628         /* Output any buffered data for stderr. */
1629         if (buffer_len(&stderr_buffer) > 0) {
1630                 len = atomicio(vwrite, fileno(stderr),
1631                     buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer));
1632                 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer))
1633                         error("Write failed flushing stderr buffer.");
1634                 else
1635                         buffer_consume(&stderr_buffer, len);
1636         }
1637
1638         /* Clear and free any buffers. */
1639         memset(buf, 0, sizeof(buf));
1640         buffer_free(&stdin_buffer);
1641         buffer_free(&stdout_buffer);
1642         buffer_free(&stderr_buffer);
1643
1644         /* Report bytes transferred, and transfer rates. */
1645         total_time = get_current_time() - start_time;
1646         packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
1647         packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1648         verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1649             (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1650         if (total_time > 0)
1651                 verbose("Bytes per second: sent %.1f, received %.1f",
1652                     obytes / total_time, ibytes / total_time);
1653         /* Return the exit status of the program. */
1654         debug("Exit status %d", exit_status);
1655         return exit_status;
1656 }
1657
1658 /*********/
1659
1660 static void
1661 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1662 {
1663         u_int data_len;
1664         char *data = packet_get_string(&data_len);
1665         packet_check_eom();
1666         buffer_append(&stdout_buffer, data, data_len);
1667         memset(data, 0, data_len);
1668         xfree(data);
1669 }
1670 static void
1671 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1672 {
1673         u_int data_len;
1674         char *data = packet_get_string(&data_len);
1675         packet_check_eom();
1676         buffer_append(&stderr_buffer, data, data_len);
1677         memset(data, 0, data_len);
1678         xfree(data);
1679 }
1680 static void
1681 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1682 {
1683         exit_status = packet_get_int();
1684         packet_check_eom();
1685         /* Acknowledge the exit. */
1686         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1687         packet_send();
1688         /*
1689          * Must wait for packet to be sent since we are
1690          * exiting the loop.
1691          */
1692         packet_write_wait();
1693         /* Flag that we want to exit. */
1694         quit_pending = 1;
1695 }
1696 static void
1697 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1698 {
1699         Channel *c = NULL;
1700         int remote_id, sock;
1701
1702         /* Read the remote channel number from the message. */
1703         remote_id = packet_get_int();
1704         packet_check_eom();
1705
1706         /*
1707          * Get a connection to the local authentication agent (this may again
1708          * get forwarded).
1709          */
1710         sock = ssh_get_authentication_socket();
1711
1712         /*
1713          * If we could not connect the agent, send an error message back to
1714          * the server. This should never happen unless the agent dies,
1715          * because authentication forwarding is only enabled if we have an
1716          * agent.
1717          */
1718         if (sock >= 0) {
1719                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1720                     -1, 0, 0, 0, "authentication agent connection", 1);
1721                 c->remote_id = remote_id;
1722                 c->force_drain = 1;
1723         }
1724         if (c == NULL) {
1725                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1726                 packet_put_int(remote_id);
1727         } else {
1728                 /* Send a confirmation to the remote host. */
1729                 debug("Forwarding authentication connection.");
1730                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1731                 packet_put_int(remote_id);
1732                 packet_put_int(c->self);
1733         }
1734         packet_send();
1735 }
1736
1737 static Channel *
1738 client_request_forwarded_tcpip(const char *request_type, int rchan)
1739 {
1740         Channel *c = NULL;
1741         char *listen_address, *originator_address;
1742         u_short listen_port, originator_port;
1743
1744         /* Get rest of the packet */
1745         listen_address = packet_get_string(NULL);
1746         listen_port = packet_get_int();
1747         originator_address = packet_get_string(NULL);
1748         originator_port = packet_get_int();
1749         packet_check_eom();
1750
1751         debug("client_request_forwarded_tcpip: listen %s port %d, "
1752             "originator %s port %d", listen_address, listen_port,
1753             originator_address, originator_port);
1754
1755         c = channel_connect_by_listen_address(listen_port,
1756             "forwarded-tcpip", originator_address);
1757
1758         xfree(originator_address);
1759         xfree(listen_address);
1760         return c;
1761 }
1762
1763 static Channel *
1764 client_request_x11(const char *request_type, int rchan)
1765 {
1766         Channel *c = NULL;
1767         char *originator;
1768         u_short originator_port;
1769         int sock;
1770
1771         if (!options.forward_x11) {
1772                 error("Warning: ssh server tried X11 forwarding.");
1773                 error("Warning: this is probably a break-in attempt by a "
1774                     "malicious server.");
1775                 return NULL;
1776         }
1777         if (x11_refuse_time != 0 && time(NULL) >= x11_refuse_time) {
1778                 verbose("Rejected X11 connection after ForwardX11Timeout "
1779                     "expired");
1780                 return NULL;
1781         }
1782         originator = packet_get_string(NULL);
1783         if (datafellows & SSH_BUG_X11FWD) {
1784                 debug2("buggy server: x11 request w/o originator_port");
1785                 originator_port = 0;
1786         } else {
1787                 originator_port = packet_get_int();
1788         }
1789         packet_check_eom();
1790         /* XXX check permission */
1791         debug("client_request_x11: request from %s %d", originator,
1792             originator_port);
1793         xfree(originator);
1794         sock = x11_connect_display();
1795         if (sock < 0)
1796                 return NULL;
1797         if (options.hpn_disabled)
1798                 c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1799                     CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1800                     0, "x11", 1);
1801         else
1802                 c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1803                     options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
1804                     0, "x11", 1);
1805         c->force_drain = 1;
1806         return c;
1807 }
1808
1809 static Channel *
1810 client_request_agent(const char *request_type, int rchan)
1811 {
1812         Channel *c = NULL;
1813         int sock;
1814
1815         if (!options.forward_agent) {
1816                 error("Warning: ssh server tried agent forwarding.");
1817                 error("Warning: this is probably a break-in attempt by a "
1818                     "malicious server.");
1819                 return NULL;
1820         }
1821         sock = ssh_get_authentication_socket();
1822         if (sock < 0)
1823                 return NULL;
1824         if (options.hpn_disabled)
1825                 c = channel_new("authentication agent connection",
1826                     SSH_CHANNEL_OPEN, sock, sock, -1,
1827                     CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1828                     "authentication agent connection", 1);
1829         else
1830                 c = channel_new("authentication agent connection",
1831                     SSH_CHANNEL_OPEN, sock, sock, -1,
1832                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1833                     "authentication agent connection", 1);
1834         c->force_drain = 1;
1835         return c;
1836 }
1837
1838 int
1839 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1840 {
1841         Channel *c;
1842         int fd;
1843
1844         if (tun_mode == SSH_TUNMODE_NO)
1845                 return 0;
1846
1847         if (!compat20) {
1848                 error("Tunnel forwarding is not supported for protocol 1");
1849                 return -1;
1850         }
1851
1852         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1853
1854         /* Open local tunnel device */
1855         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1856                 error("Tunnel device open failed.");
1857                 return -1;
1858         }
1859
1860         if (options.hpn_disabled)
1861                 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1862                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1863                     0, "tun", 1);
1864         else
1865                 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1866                     options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
1867                     0, "tun", 1);
1868         c->datagram = 1;
1869
1870 #if defined(SSH_TUN_FILTER)
1871         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1872                 channel_register_filter(c->self, sys_tun_infilter,
1873                     sys_tun_outfilter, NULL, NULL);
1874 #endif
1875
1876         packet_start(SSH2_MSG_CHANNEL_OPEN);
1877         packet_put_cstring("tun@openssh.com");
1878         packet_put_int(c->self);
1879         packet_put_int(c->local_window_max);
1880         packet_put_int(c->local_maxpacket);
1881         packet_put_int(tun_mode);
1882         packet_put_int(remote_tun);
1883         packet_send();
1884
1885         return 0;
1886 }
1887
1888 /* XXXX move to generic input handler */
1889 static void
1890 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1891 {
1892         Channel *c = NULL;
1893         char *ctype;
1894         int rchan;
1895         u_int rmaxpack, rwindow, len;
1896
1897         ctype = packet_get_string(&len);
1898         rchan = packet_get_int();
1899         rwindow = packet_get_int();
1900         rmaxpack = packet_get_int();
1901
1902         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1903             ctype, rchan, rwindow, rmaxpack);
1904
1905         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1906                 c = client_request_forwarded_tcpip(ctype, rchan);
1907         } else if (strcmp(ctype, "x11") == 0) {
1908                 c = client_request_x11(ctype, rchan);
1909         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1910                 c = client_request_agent(ctype, rchan);
1911         }
1912 /* XXX duplicate : */
1913         if (c != NULL) {
1914                 debug("confirm %s", ctype);
1915                 c->remote_id = rchan;
1916                 c->remote_window = rwindow;
1917                 c->remote_maxpacket = rmaxpack;
1918                 if (c->type != SSH_CHANNEL_CONNECTING) {
1919                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1920                         packet_put_int(c->remote_id);
1921                         packet_put_int(c->self);
1922                         packet_put_int(c->local_window);
1923                         packet_put_int(c->local_maxpacket);
1924                         packet_send();
1925                 }
1926         } else {
1927                 debug("failure %s", ctype);
1928                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1929                 packet_put_int(rchan);
1930                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1931                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1932                         packet_put_cstring("open failed");
1933                         packet_put_cstring("");
1934                 }
1935                 packet_send();
1936         }
1937         xfree(ctype);
1938 }
1939 static void
1940 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1941 {
1942         Channel *c = NULL;
1943         int exitval, id, reply, success = 0;
1944         char *rtype;
1945
1946         id = packet_get_int();
1947         rtype = packet_get_string(NULL);
1948         reply = packet_get_char();
1949
1950         debug("client_input_channel_req: channel %d rtype %s reply %d",
1951             id, rtype, reply);
1952
1953         if (id == -1) {
1954                 error("client_input_channel_req: request for channel -1");
1955         } else if ((c = channel_lookup(id)) == NULL) {
1956                 error("client_input_channel_req: channel %d: "
1957                     "unknown channel", id);
1958         } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1959                 packet_check_eom();
1960                 chan_rcvd_eow(c);
1961         } else if (strcmp(rtype, "exit-status") == 0) {
1962                 exitval = packet_get_int();
1963                 if (c->ctl_chan != -1) {
1964                         mux_exit_message(c, exitval);
1965                         success = 1;
1966                 } else if (id == session_ident) {
1967                         /* Record exit value of local session */
1968                         success = 1;
1969                         exit_status = exitval;
1970                 } else {
1971                         /* Probably for a mux channel that has already closed */
1972                         debug("%s: no sink for exit-status on channel %d",
1973                             __func__, id);
1974                 }
1975                 packet_check_eom();
1976         }
1977         if (reply && c != NULL) {
1978                 packet_start(success ?
1979                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1980                 packet_put_int(c->remote_id);
1981                 packet_send();
1982         }
1983         xfree(rtype);
1984 }
1985 static void
1986 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1987 {
1988         char *rtype;
1989         int want_reply;
1990         int success = 0;
1991
1992         rtype = packet_get_string(NULL);
1993         want_reply = packet_get_char();
1994         debug("client_input_global_request: rtype %s want_reply %d",
1995             rtype, want_reply);
1996         if (want_reply) {
1997                 packet_start(success ?
1998                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1999                 packet_send();
2000                 packet_write_wait();
2001         }
2002         xfree(rtype);
2003 }
2004
2005 void
2006 client_session2_setup(int id, int want_tty, int want_subsystem,
2007     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
2008 {
2009         int len;
2010         Channel *c = NULL;
2011
2012         debug2("%s: id %d", __func__, id);
2013
2014         if ((c = channel_lookup(id)) == NULL)
2015                 fatal("client_session2_setup: channel %d: unknown channel", id);
2016
2017         packet_set_interactive(want_tty,
2018             options.ip_qos_interactive, options.ip_qos_bulk);
2019
2020         if (want_tty) {
2021                 struct winsize ws;
2022
2023                 /* Store window size in the packet. */
2024                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
2025                         memset(&ws, 0, sizeof(ws));
2026
2027                 channel_request_start(id, "pty-req", 1);
2028                 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY);
2029                 packet_put_cstring(term != NULL ? term : "");
2030                 packet_put_int((u_int)ws.ws_col);
2031                 packet_put_int((u_int)ws.ws_row);
2032                 packet_put_int((u_int)ws.ws_xpixel);
2033                 packet_put_int((u_int)ws.ws_ypixel);
2034                 if (tiop == NULL)
2035                         tiop = get_saved_tio();
2036                 tty_make_modes(-1, tiop);
2037                 packet_send();
2038                 /* XXX wait for reply */
2039                 c->client_tty = 1;
2040         }
2041
2042         /* Transfer any environment variables from client to server */
2043         if (options.num_send_env != 0 && env != NULL) {
2044                 int i, j, matched;
2045                 char *name, *val;
2046
2047                 debug("Sending environment.");
2048                 for (i = 0; env[i] != NULL; i++) {
2049                         /* Split */
2050                         name = xstrdup(env[i]);
2051                         if ((val = strchr(name, '=')) == NULL) {
2052                                 xfree(name);
2053                                 continue;
2054                         }
2055                         *val++ = '\0';
2056
2057                         matched = 0;
2058                         for (j = 0; j < options.num_send_env; j++) {
2059                                 if (match_pattern(name, options.send_env[j])) {
2060                                         matched = 1;
2061                                         break;
2062                                 }
2063                         }
2064                         if (!matched) {
2065                                 debug3("Ignored env %s", name);
2066                                 xfree(name);
2067                                 continue;
2068                         }
2069
2070                         debug("Sending env %s = %s", name, val);
2071                         channel_request_start(id, "env", 0);
2072                         packet_put_cstring(name);
2073                         packet_put_cstring(val);
2074                         packet_send();
2075                         xfree(name);
2076                 }
2077         }
2078
2079         len = buffer_len(cmd);
2080         if (len > 0) {
2081                 if (len > 900)
2082                         len = 900;
2083                 if (want_subsystem) {
2084                         debug("Sending subsystem: %.*s",
2085                             len, (u_char*)buffer_ptr(cmd));
2086                         channel_request_start(id, "subsystem", 1);
2087                         client_expect_confirm(id, "subsystem", CONFIRM_CLOSE);
2088                 } else {
2089                         debug("Sending command: %.*s",
2090                             len, (u_char*)buffer_ptr(cmd));
2091                         channel_request_start(id, "exec", 1);
2092                         client_expect_confirm(id, "exec", CONFIRM_CLOSE);
2093                 }
2094                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2095                 packet_send();
2096         } else {
2097                 channel_request_start(id, "shell", 1);
2098                 client_expect_confirm(id, "shell", CONFIRM_CLOSE);
2099                 packet_send();
2100         }
2101 }
2102
2103 static void
2104 client_init_dispatch_20(void)
2105 {
2106         dispatch_init(&dispatch_protocol_error);
2107
2108         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2109         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2110         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2111         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2112         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2113         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2114         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2115         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2116         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2117         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2118         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2119         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2120
2121         /* rekeying */
2122         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2123
2124         /* global request reply messages */
2125         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2126         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2127 }
2128
2129 static void
2130 client_init_dispatch_13(void)
2131 {
2132         dispatch_init(NULL);
2133         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2134         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2135         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2136         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2137         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2138         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2139         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2140         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2141         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2142
2143         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2144             &client_input_agent_open : &deny_input_open);
2145         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2146             &x11_input_open : &deny_input_open);
2147 }
2148
2149 static void
2150 client_init_dispatch_15(void)
2151 {
2152         client_init_dispatch_13();
2153         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2154         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2155 }
2156
2157 static void
2158 client_init_dispatch(void)
2159 {
2160         if (compat20)
2161                 client_init_dispatch_20();
2162         else if (compat13)
2163                 client_init_dispatch_13();
2164         else
2165                 client_init_dispatch_15();
2166 }
2167
2168 void
2169 client_stop_mux(void)
2170 {
2171         if (options.control_path != NULL && muxserver_sock != -1)
2172                 unlink(options.control_path);
2173         /*
2174          * If we are in persist mode, signal that we should close when all
2175          * active channels are closed.
2176          */
2177         if (options.control_persist) {
2178                 session_closed = 1;
2179                 setproctitle("[stopped mux]");
2180         }
2181 }
2182
2183 /* client specific fatal cleanup */
2184 void
2185 cleanup_exit(int i)
2186 {
2187         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2188         leave_non_blocking();
2189         if (options.control_path != NULL && muxserver_sock != -1)
2190                 unlink(options.control_path);
2191         ssh_kill_proxy_command();
2192         _exit(i);
2193 }