clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.231 2011/01/16 12:05:59 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * The main loop for the interactive session (client side).
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  *
  15  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  *
  38  * SSH2 support added by Markus Friedl.
  39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #include "includes.h"
  63
  64 #include <sys/types.h>
  65 #include <sys/ioctl.h>
  66 #include <sys/param.h>
  67 #ifdef HAVE_SYS_STAT_H
  68 # include <sys/stat.h>
  69 #endif
  70 #ifdef HAVE_SYS_TIME_H
  71 # include <sys/time.h>
  72 #endif
  73 #include <sys/socket.h>
  74
  75 #include <ctype.h>
  76 #include <errno.h>
  77 #ifdef HAVE_PATHS_H
  78 #include <paths.h>
  79 #endif
  80 #include <signal.h>
  81 #include <stdarg.h>
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <string.h>
  85 #include <termios.h>
  86 #include <pwd.h>
  87 #include <unistd.h>
  88
  89 #include "openbsd-compat/sys-queue.h"
  90 #include "xmalloc.h"
  91 #include "ssh.h"
  92 #include "ssh1.h"
  93 #include "ssh2.h"
  94 #include "packet.h"
  95 #include "buffer.h"
  96 #include "compat.h"
  97 #include "channels.h"
  98 #include "dispatch.h"
  99 #include "key.h"
 100 #include "cipher.h"
 101 #include "kex.h"
 102 #include "log.h"
 103 #include "readconf.h"
 104 #include "clientloop.h"
 105 #include "sshconnect.h"
 106 #include "authfd.h"
 107 #include "atomicio.h"
 108 #include "sshpty.h"
 109 #include "misc.h"
 110 #include "match.h"
 111 #include "msg.h"
 112 #include "roaming.h"
 113
 114 /* import options */
 115 extern Options options;
 116
 117 /* Flag indicating that stdin should be redirected from /dev/null. */
 118 extern int stdin_null_flag;
 119
 120 /* Flag indicating that no shell has been requested */
 121 extern int no_shell_flag;
 122
 123 /* Control socket */
 124 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
 125
 126 /*
 127  * Name of the host we are connecting to.  This is the name given on the
 128  * command line, or the HostName specified for the user-supplied name in a
 129  * configuration file.
 130  */
 131 extern char *host;
 132
 133 /* Force TTY allocation */
 134 extern int force_tty_flag;
 135
 136 /*
 137  * Flag to indicate that we have received a window change signal which has
 138  * not yet been processed.  This will cause a message indicating the new
 139  * window size to be sent to the server a little later.  This is volatile
 140  * because this is updated in a signal handler.
 141  */
 142 static volatile sig_atomic_t received_window_change_signal = 0;
 143 static volatile sig_atomic_t received_signal = 0;
 144
 145 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 146 static int in_non_blocking_mode = 0;
 147
 148 /* Time when backgrounded control master using ControlPersist should exit */
 149 static time_t control_persist_exit_time = 0;
 150
 151 /* Common data for the client loop code. */
 152 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 153 static int escape_char1;        /* Escape character. (proto1 only) */
 154 static int escape_pending1;     /* Last character was an escape (proto1 only) */
 155 static int last_was_cr;         /* Last character was a newline. */
 156 static int exit_status;         /* Used to store the command exit status. */
 157 static int stdin_eof;           /* EOF has been encountered on stderr. */
 158 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 159 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 160 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 161 static u_int buffer_high;       /* Soft max buffer size. */
 162 static int connection_in;       /* Connection to server (input). */
 163 static int connection_out;      /* Connection to server (output). */
 164 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 165 static int session_closed;      /* In SSH2: login session closed. */
 166 static int x11_refuse_time;     /* If >0, refuse x11 opens after this time. */
 167
 168 static void client_init_dispatch(void);
 169 int     session_ident = -1;
 170
 171 int     session_resumed = 0;
 172
 173 /* Track escape per proto2 channel */
 174 struct escape_filter_ctx {
 175         int escape_pending;
 176         int escape_char;
 177 };
 178
 179 /* Context for channel confirmation replies */
 180 struct channel_reply_ctx {
 181         const char *request_type;
 182         int id, do_close;
 183 };
 184
 185 /* Global request success/failure callbacks */
 186 struct global_confirm {
 187         TAILQ_ENTRY(global_confirm) entry;
 188         global_confirm_cb *cb;
 189         void *ctx;
 190         int ref_count;
 191 };
 192 TAILQ_HEAD(global_confirms, global_confirm);
 193 static struct global_confirms global_confirms =
 194     TAILQ_HEAD_INITIALIZER(global_confirms);
 195
 196 /*XXX*/
 197 extern Kex *xxx_kex;
 198
 199 void ssh_process_session2_setup(int, int, int, Buffer *);
 200
 201 /* Restores stdin to blocking mode. */
 202
 203 static void
 204 leave_non_blocking(void)
 205 {
 206         if (in_non_blocking_mode) {
 207                 unset_nonblock(fileno(stdin));
 208                 in_non_blocking_mode = 0;
 209         }
 210 }
 211
 212 /* Puts stdin terminal in non-blocking mode. */
 213
 214 static void
 215 enter_non_blocking(void)
 216 {
 217         in_non_blocking_mode = 1;
 218         set_nonblock(fileno(stdin));
 219 }
 220
 221 /*
 222  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 223  * flag indicating that the window has changed.
 224  */
 225 /*ARGSUSED */
 226 static void
 227 window_change_handler(int sig)
 228 {
 229         received_window_change_signal = 1;
 230         signal(SIGWINCH, window_change_handler);
 231 }
 232
 233 /*
 234  * Signal handler for signals that cause the program to terminate.  These
 235  * signals must be trapped to restore terminal modes.
 236  */
 237 /*ARGSUSED */
 238 static void
 239 signal_handler(int sig)
 240 {
 241         received_signal = sig;
 242         quit_pending = 1;
 243 }
 244
 245 /*
 246  * Returns current time in seconds from Jan 1, 1970 with the maximum
 247  * available resolution.
 248  */
 249
 250 static double
 251 get_current_time(void)
 252 {
 253         struct timeval tv;
 254         gettimeofday(&tv, NULL);
 255         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 256 }
 257
 258 /*
 259  * Sets control_persist_exit_time to the absolute time when the
 260  * backgrounded control master should exit due to expiry of the
 261  * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
 262  * control master process, or if there is no ControlPersist timeout.
 263  */
 264 static void
 265 set_control_persist_exit_time(void)
 266 {
 267         if (muxserver_sock == -1 || !options.control_persist
 268             || options.control_persist_timeout == 0)
 269                 /* not using a ControlPersist timeout */
 270                 control_persist_exit_time = 0;
 271         else if (channel_still_open()) {
 272                 /* some client connections are still open */
 273                 if (control_persist_exit_time > 0)
 274                         debug2("%s: cancel scheduled exit", __func__);
 275                 control_persist_exit_time = 0;
 276         } else if (control_persist_exit_time <= 0) {
 277                 /* a client connection has recently closed */
 278                 control_persist_exit_time = time(NULL) +
 279                         (time_t)options.control_persist_timeout;
 280                 debug2("%s: schedule exit in %d seconds", __func__,
 281                     options.control_persist_timeout);
 282         }
 283         /* else we are already counting down to the timeout */
 284 }
 285
 286 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 287 void
 288 client_x11_get_proto(const char *display, const char *xauth_path,
 289     u_int trusted, u_int timeout, char **_proto, char **_data)
 290 {
 291         char cmd[1024];
 292         char line[512];
 293         char xdisplay[512];
 294         static char proto[512], data[512];
 295         FILE *f;
 296         int got_data = 0, generated = 0, do_unlink = 0, i;
 297         char *xauthdir, *xauthfile;
 298         struct stat st;
 299         u_int now;
 300
 301         xauthdir = xauthfile = NULL;
 302         *_proto = proto;
 303         *_data = data;
 304         proto[0] = data[0] = '\0';
 305
 306         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 307                 debug("No xauth program.");
 308         } else {
 309                 if (display == NULL) {
 310                         debug("x11_get_proto: DISPLAY not set");
 311                         return;
 312                 }
 313                 /*
 314                  * Handle FamilyLocal case where $DISPLAY does
 315                  * not match an authorization entry.  For this we
 316                  * just try "xauth list unix:displaynum.screennum".
 317                  * XXX: "localhost" match to determine FamilyLocal
 318                  *      is not perfect.
 319                  */
 320                 if (strncmp(display, "localhost:", 10) == 0) {
 321                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 322                             display + 10);
 323                         display = xdisplay;
 324                 }
 325                 if (trusted == 0) {
 326                         xauthdir = xmalloc(MAXPATHLEN);
 327                         xauthfile = xmalloc(MAXPATHLEN);
 328                         mktemp_proto(xauthdir, MAXPATHLEN);
 329                         if (mkdtemp(xauthdir) != NULL) {
 330                                 do_unlink = 1;
 331                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 332                                     xauthdir);
 333                                 snprintf(cmd, sizeof(cmd),
 334                                     "%s -f %s generate %s " SSH_X11_PROTO
 335                                     " untrusted timeout %u 2>" _PATH_DEVNULL,
 336                                     xauth_path, xauthfile, display, timeout);
 337                                 debug2("x11_get_proto: %s", cmd);
 338                                 if (system(cmd) == 0)
 339                                         generated = 1;
 340                                 if (x11_refuse_time == 0) {
 341                                         now = time(NULL) + 1;
 342                                         if (UINT_MAX - timeout < now)
 343                                                 x11_refuse_time = UINT_MAX;
 344                                         else
 345                                                 x11_refuse_time = now + timeout;
 346                                 }
 347                         }
 348                 }
 349
 350                 /*
 351                  * When in untrusted mode, we read the cookie only if it was
 352                  * successfully generated as an untrusted one in the step
 353                  * above.
 354                  */
 355                 if (trusted || generated) {
 356                         snprintf(cmd, sizeof(cmd),
 357                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 358                             xauth_path,
 359                             generated ? "-f " : "" ,
 360                             generated ? xauthfile : "",
 361                             display);
 362                         debug2("x11_get_proto: %s", cmd);
 363                         f = popen(cmd, "r");
 364                         if (f && fgets(line, sizeof(line), f) &&
 365                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 366                                 got_data = 1;
 367                         if (f)
 368                                 pclose(f);
 369                 } else
 370                         error("Warning: untrusted X11 forwarding setup failed: "
 371                             "xauth key data not generated");
 372         }
 373
 374         if (do_unlink) {
 375                 unlink(xauthfile);
 376                 rmdir(xauthdir);
 377         }
 378         if (xauthdir)
 379                 xfree(xauthdir);
 380         if (xauthfile)
 381                 xfree(xauthfile);
 382
 383         /*
 384          * If we didn't get authentication data, just make up some
 385          * data.  The forwarding code will check the validity of the
 386          * response anyway, and substitute this data.  The X11
 387          * server, however, will ignore this fake data and use
 388          * whatever authentication mechanisms it was using otherwise
 389          * for the local connection.
 390          */
 391         if (!got_data) {
 392                 u_int32_t rnd = 0;
 393
 394                 logit("Warning: No xauth data; "
 395                     "using fake authentication data for X11 forwarding.");
 396                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 397                 for (i = 0; i < 16; i++) {
 398                         if (i % 4 == 0)
 399                                 rnd = arc4random();
 400                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 401                             rnd & 0xff);
 402                         rnd >>= 8;
 403                 }
 404         }
 405 }
 406
 407 /*
 408  * This is called when the interactive is entered.  This checks if there is
 409  * an EOF coming on stdin.  We must check this explicitly, as select() does
 410  * not appear to wake up when redirecting from /dev/null.
 411  */
 412
 413 static void
 414 client_check_initial_eof_on_stdin(void)
 415 {
 416         int len;
 417         char buf[1];
 418
 419         /*
 420          * If standard input is to be "redirected from /dev/null", we simply
 421          * mark that we have seen an EOF and send an EOF message to the
 422          * server. Otherwise, we try to read a single character; it appears
 423          * that for some files, such /dev/null, select() never wakes up for
 424          * read for this descriptor, which means that we never get EOF.  This
 425          * way we will get the EOF if stdin comes from /dev/null or similar.
 426          */
 427         if (stdin_null_flag) {
 428                 /* Fake EOF on stdin. */
 429                 debug("Sending eof.");
 430                 stdin_eof = 1;
 431                 packet_start(SSH_CMSG_EOF);
 432                 packet_send();
 433         } else {
 434                 enter_non_blocking();
 435
 436                 /* Check for immediate EOF on stdin. */
 437                 len = read(fileno(stdin), buf, 1);
 438                 if (len == 0) {
 439                         /*
 440                          * EOF.  Record that we have seen it and send
 441                          * EOF to server.
 442                          */
 443                         debug("Sending eof.");
 444                         stdin_eof = 1;
 445                         packet_start(SSH_CMSG_EOF);
 446                         packet_send();
 447                 } else if (len > 0) {
 448                         /*
 449                          * Got data.  We must store the data in the buffer,
 450                          * and also process it as an escape character if
 451                          * appropriate.
 452                          */
 453                         if ((u_char) buf[0] == escape_char1)
 454                                 escape_pending1 = 1;
 455                         else
 456                                 buffer_append(&stdin_buffer, buf, 1);
 457                 }
 458                 leave_non_blocking();
 459         }
 460 }
 461
 462
 463 /*
 464  * Make packets from buffered stdin data, and buffer them for sending to the
 465  * connection.
 466  */
 467
 468 static void
 469 client_make_packets_from_stdin_data(void)
 470 {
 471         u_int len;
 472
 473         /* Send buffered stdin data to the server. */
 474         while (buffer_len(&stdin_buffer) > 0 &&
 475             packet_not_very_much_data_to_write()) {
 476                 len = buffer_len(&stdin_buffer);
 477                 /* Keep the packets at reasonable size. */
 478                 if (len > packet_get_maxsize())
 479                         len = packet_get_maxsize();
 480                 packet_start(SSH_CMSG_STDIN_DATA);
 481                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 482                 packet_send();
 483                 buffer_consume(&stdin_buffer, len);
 484                 /* If we have a pending EOF, send it now. */
 485                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 486                         packet_start(SSH_CMSG_EOF);
 487                         packet_send();
 488                 }
 489         }
 490 }
 491
 492 /*
 493  * Checks if the client window has changed, and sends a packet about it to
 494  * the server if so.  The actual change is detected elsewhere (by a software
 495  * interrupt on Unix); this just checks the flag and sends a message if
 496  * appropriate.
 497  */
 498
 499 static void
 500 client_check_window_change(void)
 501 {
 502         struct winsize ws;
 503
 504         if (! received_window_change_signal)
 505                 return;
 506         /** XXX race */
 507         received_window_change_signal = 0;
 508
 509         debug2("client_check_window_change: changed");
 510
 511         if (compat20) {
 512                 channel_send_window_changes();
 513         } else {
 514                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 515                         return;
 516                 packet_start(SSH_CMSG_WINDOW_SIZE);
 517                 packet_put_int((u_int)ws.ws_row);
 518                 packet_put_int((u_int)ws.ws_col);
 519                 packet_put_int((u_int)ws.ws_xpixel);
 520                 packet_put_int((u_int)ws.ws_ypixel);
 521                 packet_send();
 522         }
 523 }
 524
 525 static void
 526 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 527 {
 528         struct global_confirm *gc;
 529
 530         if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
 531                 return;
 532         if (gc->cb != NULL)
 533                 gc->cb(type, seq, gc->ctx);
 534         if (--gc->ref_count <= 0) {
 535                 TAILQ_REMOVE(&global_confirms, gc, entry);
 536                 bzero(gc, sizeof(*gc));
 537                 xfree(gc);
 538         }
 539
 540         packet_set_alive_timeouts(0);
 541 }
 542
 543 static void
 544 server_alive_check(void)
 545 {
 546         if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
 547                 logit("Timeout, server %s not responding.", host);
 548                 cleanup_exit(255);
 549         }
 550         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 551         packet_put_cstring("keepalive@openssh.com");
 552         packet_put_char(1);     /* boolean: want reply */
 553         packet_send();
 554         /* Insert an empty placeholder to maintain ordering */
 555         client_register_global_confirm(NULL, NULL);
 556 }
 557
 558 /*
 559  * Waits until the client can do something (some data becomes available on
 560  * one of the file descriptors).
 561  */
 562 static void
 563 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 564     int *maxfdp, u_int *nallocp, int rekeying)
 565 {
 566         struct timeval tv, *tvp;
 567         int timeout_secs;
 568         int ret;
 569
 570         /* Add any selections by the channel mechanism. */
 571         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 572
 573         if (!compat20) {
 574                 /* Read from the connection, unless our buffers are full. */
 575                 if (buffer_len(&stdout_buffer) < buffer_high &&
 576                     buffer_len(&stderr_buffer) < buffer_high &&
 577                     channel_not_very_much_buffered_data())
 578                         FD_SET(connection_in, *readsetp);
 579                 /*
 580                  * Read from stdin, unless we have seen EOF or have very much
 581                  * buffered data to send to the server.
 582                  */
 583                 if (!stdin_eof && packet_not_very_much_data_to_write())
 584                         FD_SET(fileno(stdin), *readsetp);
 585
 586                 /* Select stdout/stderr if have data in buffer. */
 587                 if (buffer_len(&stdout_buffer) > 0)
 588                         FD_SET(fileno(stdout), *writesetp);
 589                 if (buffer_len(&stderr_buffer) > 0)
 590                         FD_SET(fileno(stderr), *writesetp);
 591         } else {
 592                 /* channel_prepare_select could have closed the last channel */
 593                 if (session_closed && !channel_still_open() &&
 594                     !packet_have_data_to_write()) {
 595                         /* clear mask since we did not call select() */
 596                         memset(*readsetp, 0, *nallocp);
 597                         memset(*writesetp, 0, *nallocp);
 598                         return;
 599                 } else {
 600                         FD_SET(connection_in, *readsetp);
 601                 }
 602         }
 603
 604         /* Select server connection if have data to write to the server. */
 605         if (packet_have_data_to_write())
 606                 FD_SET(connection_out, *writesetp);
 607
 608         /*
 609          * Wait for something to happen.  This will suspend the process until
 610          * some selected descriptor can be read, written, or has some other
 611          * event pending, or a timeout expires.
 612          */
 613
 614         timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
 615         if (options.server_alive_interval > 0 && compat20)
 616                 timeout_secs = options.server_alive_interval;
 617         set_control_persist_exit_time();
 618         if (control_persist_exit_time > 0) {
 619                 timeout_secs = MIN(timeout_secs,
 620                         control_persist_exit_time - time(NULL));
 621                 if (timeout_secs < 0)
 622                         timeout_secs = 0;
 623         }
 624         if (timeout_secs == INT_MAX)
 625                 tvp = NULL;
 626         else {
 627                 tv.tv_sec = timeout_secs;
 628                 tv.tv_usec = 0;
 629                 tvp = &tv;
 630         }
 631
 632         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 633         if (ret < 0) {
 634                 char buf[100];
 635
 636                 /*
 637                  * We have to clear the select masks, because we return.
 638                  * We have to return, because the mainloop checks for the flags
 639                  * set by the signal handlers.
 640                  */
 641                 memset(*readsetp, 0, *nallocp);
 642                 memset(*writesetp, 0, *nallocp);
 643
 644                 if (errno == EINTR)
 645                         return;
 646                 /* Note: we might still have data in the buffers. */
 647                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 648                 buffer_append(&stderr_buffer, buf, strlen(buf));
 649                 quit_pending = 1;
 650         } else if (ret == 0)
 651                 server_alive_check();
 652 }
 653
 654 static void
 655 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 656 {
 657         /* Flush stdout and stderr buffers. */
 658         if (buffer_len(bout) > 0)
 659                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
 660                     buffer_len(bout));
 661         if (buffer_len(berr) > 0)
 662                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
 663                     buffer_len(berr));
 664
 665         leave_raw_mode(force_tty_flag);
 666
 667         /*
 668          * Free (and clear) the buffer to reduce the amount of data that gets
 669          * written to swap.
 670          */
 671         buffer_free(bin);
 672         buffer_free(bout);
 673         buffer_free(berr);
 674
 675         /* Send the suspend signal to the program itself. */
 676         kill(getpid(), SIGTSTP);
 677
 678         /* Reset window sizes in case they have changed */
 679         received_window_change_signal = 1;
 680
 681         /* OK, we have been continued by the user. Reinitialize buffers. */
 682         buffer_init(bin);
 683         buffer_init(bout);
 684         buffer_init(berr);
 685
 686         enter_raw_mode(force_tty_flag);
 687 }
 688
 689 static void
 690 client_process_net_input(fd_set *readset)
 691 {
 692         int len, cont = 0;
 693         char buf[SSH_IOBUFSZ];
 694
 695         /*
 696          * Read input from the server, and add any such data to the buffer of
 697          * the packet subsystem.
 698          */
 699         if (FD_ISSET(connection_in, readset)) {
 700                 /* Read as much as possible. */
 701                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 702                 if (len == 0 && cont == 0) {
 703                         /*
 704                          * Received EOF.  The remote host has closed the
 705                          * connection.
 706                          */
 707                         snprintf(buf, sizeof buf,
 708                             "Connection to %.300s closed by remote host.\r\n",
 709                             host);
 710                         buffer_append(&stderr_buffer, buf, strlen(buf));
 711                         quit_pending = 1;
 712                         return;
 713                 }
 714                 /*
 715                  * There is a kernel bug on Solaris that causes select to
 716                  * sometimes wake up even though there is no data available.
 717                  */
 718                 if (len < 0 &&
 719                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 720                         len = 0;
 721
 722                 if (len < 0) {
 723                         /*
 724                          * An error has encountered.  Perhaps there is a
 725                          * network problem.
 726                          */
 727                         snprintf(buf, sizeof buf,
 728                             "Read from remote host %.300s: %.100s\r\n",
 729                             host, strerror(errno));
 730                         buffer_append(&stderr_buffer, buf, strlen(buf));
 731                         quit_pending = 1;
 732                         return;
 733                 }
 734                 packet_process_incoming(buf, len);
 735         }
 736 }
 737
 738 static void
 739 client_status_confirm(int type, Channel *c, void *ctx)
 740 {
 741         struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
 742         char errmsg[256];
 743         int tochan;
 744
 745         /* XXX supress on mux _client_ quietmode */
 746         tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
 747             c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
 748
 749         if (type == SSH2_MSG_CHANNEL_SUCCESS) {
 750                 debug2("%s request accepted on channel %d",
 751                     cr->request_type, c->self);
 752         } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 753                 if (tochan) {
 754                         snprintf(errmsg, sizeof(errmsg),
 755                             "%s request failed\r\n", cr->request_type);
 756                 } else {
 757                         snprintf(errmsg, sizeof(errmsg),
 758                             "%s request failed on channel %d",
 759                             cr->request_type, c->self);
 760                 }
 761                 /* If error occurred on primary session channel, then exit */
 762                 if (cr->do_close && c->self == session_ident)
 763                         fatal("%s", errmsg);
 764                 /* If error occurred on mux client, append to their stderr */
 765                 if (tochan)
 766                         buffer_append(&c->extended, errmsg, strlen(errmsg));
 767                 else
 768                         error("%s", errmsg);
 769                 if (cr->do_close) {
 770                         chan_read_failed(c);
 771                         chan_write_failed(c);
 772                 }
 773         }
 774         xfree(cr);
 775 }
 776
 777 static void
 778 client_abandon_status_confirm(Channel *c, void *ctx)
 779 {
 780         xfree(ctx);
 781 }
 782
 783 static void
 784 client_expect_confirm(int id, const char *request, int do_close)
 785 {
 786         struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
 787
 788         cr->request_type = request;
 789         cr->do_close = do_close;
 790
 791         channel_register_status_confirm(id, client_status_confirm,
 792             client_abandon_status_confirm, cr);
 793 }
 794
 795 void
 796 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
 797 {
 798         struct global_confirm *gc, *last_gc;
 799
 800         /* Coalesce identical callbacks */
 801         last_gc = TAILQ_LAST(&global_confirms, global_confirms);
 802         if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
 803                 if (++last_gc->ref_count >= INT_MAX)
 804                         fatal("%s: last_gc->ref_count = %d",
 805                             __func__, last_gc->ref_count);
 806                 return;
 807         }
 808
 809         gc = xmalloc(sizeof(*gc));
 810         gc->cb = cb;
 811         gc->ctx = ctx;
 812         gc->ref_count = 1;
 813         TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
 814 }
 815
 816 static void
 817 process_cmdline(void)
 818 {
 819         void (*handler)(int);
 820         char *s, *cmd, *cancel_host;
 821         int delete = 0;
 822         int local = 0, remote = 0, dynamic = 0;
 823         int cancel_port;
 824         Forward fwd;
 825
 826         bzero(&fwd, sizeof(fwd));
 827         fwd.listen_host = fwd.connect_host = NULL;
 828
 829         leave_raw_mode(force_tty_flag);
 830         handler = signal(SIGINT, SIG_IGN);
 831         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 832         if (s == NULL)
 833                 goto out;
 834         while (isspace(*s))
 835                 s++;
 836         if (*s == '-')
 837                 s++;    /* Skip cmdline '-', if any */
 838         if (*s == '\0')
 839                 goto out;
 840
 841         if (*s == 'h' || *s == 'H' || *s == '?') {
 842                 logit("Commands:");
 843                 logit("      -L[bind_address:]port:host:hostport    "
 844                     "Request local forward");
 845                 logit("      -R[bind_address:]port:host:hostport    "
 846                     "Request remote forward");
 847                 logit("      -D[bind_address:]port                  "
 848                     "Request dynamic forward");
 849                 logit("      -KR[bind_address:]port                 "
 850                     "Cancel remote forward");
 851                 if (!options.permit_local_command)
 852                         goto out;
 853                 logit("      !args                                  "
 854                     "Execute local command");
 855                 goto out;
 856         }
 857
 858         if (*s == '!' && options.permit_local_command) {
 859                 s++;
 860                 ssh_local_cmd(s);
 861                 goto out;
 862         }
 863
 864         if (*s == 'K') {
 865                 delete = 1;
 866                 s++;
 867         }
 868         if (*s == 'L')
 869                 local = 1;
 870         else if (*s == 'R')
 871                 remote = 1;
 872         else if (*s == 'D')
 873                 dynamic = 1;
 874         else {
 875                 logit("Invalid command.");
 876                 goto out;
 877         }
 878
 879         if ((local || dynamic) && delete) {
 880                 logit("Not supported.");
 881                 goto out;
 882         }
 883         if (remote && delete && !compat20) {
 884                 logit("Not supported for SSH protocol version 1.");
 885                 goto out;
 886         }
 887
 888         while (isspace(*++s))
 889                 ;
 890
 891         /* XXX update list of forwards in options */
 892         if (delete) {
 893                 cancel_port = 0;
 894                 cancel_host = hpdelim(&s);      /* may be NULL */
 895                 if (s != NULL) {
 896                         cancel_port = a2port(s);
 897                         cancel_host = cleanhostname(cancel_host);
 898                 } else {
 899                         cancel_port = a2port(cancel_host);
 900                         cancel_host = NULL;
 901                 }
 902                 if (cancel_port <= 0) {
 903                         logit("Bad forwarding close port");
 904                         goto out;
 905                 }
 906                 channel_request_rforward_cancel(cancel_host, cancel_port);
 907         } else {
 908                 if (!parse_forward(&fwd, s, dynamic, remote)) {
 909                         logit("Bad forwarding specification.");
 910                         goto out;
 911                 }
 912                 if (local || dynamic) {
 913                         if (channel_setup_local_fwd_listener(fwd.listen_host,
 914                             fwd.listen_port, fwd.connect_host,
 915                             fwd.connect_port, options.gateway_ports) < 0) {
 916                                 logit("Port forwarding failed.");
 917                                 goto out;
 918                         }
 919                 } else {
 920                         if (channel_request_remote_forwarding(fwd.listen_host,
 921                             fwd.listen_port, fwd.connect_host,
 922                             fwd.connect_port) < 0) {
 923                                 logit("Port forwarding failed.");
 924                                 goto out;
 925                         }
 926                 }
 927
 928                 logit("Forwarding port.");
 929         }
 930
 931 out:
 932         signal(SIGINT, handler);
 933         enter_raw_mode(force_tty_flag);
 934         if (cmd)
 935                 xfree(cmd);
 936         if (fwd.listen_host != NULL)
 937                 xfree(fwd.listen_host);
 938         if (fwd.connect_host != NULL)
 939                 xfree(fwd.connect_host);
 940 }
 941
 942 /*
 943  * Process the characters one by one, call with c==NULL for proto1 case.
 944  */
 945 static int
 946 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
 947     char *buf, int len)
 948 {
 949         char string[1024];
 950         pid_t pid;
 951         int bytes = 0;
 952         u_int i;
 953         u_char ch;
 954         char *s;
 955         int *escape_pendingp, escape_char;
 956         struct escape_filter_ctx *efc;
 957
 958         if (c == NULL) {
 959                 escape_pendingp = &escape_pending1;
 960                 escape_char = escape_char1;
 961         } else {
 962                 if (c->filter_ctx == NULL)
 963                         return 0;
 964                 efc = (struct escape_filter_ctx *)c->filter_ctx;
 965                 escape_pendingp = &efc->escape_pending;
 966                 escape_char = efc->escape_char;
 967         }
 968
 969         if (len <= 0)
 970                 return (0);
 971
 972         for (i = 0; i < (u_int)len; i++) {
 973                 /* Get one character at a time. */
 974                 ch = buf[i];
 975
 976                 if (*escape_pendingp) {
 977                         /* We have previously seen an escape character. */
 978                         /* Clear the flag now. */
 979                         *escape_pendingp = 0;
 980
 981                         /* Process the escaped character. */
 982                         switch (ch) {
 983                         case '.':
 984                                 /* Terminate the connection. */
 985                                 snprintf(string, sizeof string, "%c.\r\n",
 986                                     escape_char);
 987                                 buffer_append(berr, string, strlen(string));
 988
 989                                 if (c && c->ctl_chan != -1) {
 990                                         chan_read_failed(c);
 991                                         chan_write_failed(c);
 992                                         return 0;
 993                                 } else
 994                                         quit_pending = 1;
 995                                 return -1;
 996
 997                         case 'Z' - 64:
 998                                 /* XXX support this for mux clients */
 999                                 if (c && c->ctl_chan != -1) {
1000  noescape:
1001                                         snprintf(string, sizeof string,
1002                                             "%c%c escape not available to "
1003                                             "multiplexed sessions\r\n",
1004                                             escape_char, ch);
1005                                         buffer_append(berr, string,
1006                                             strlen(string));
1007                                         continue;
1008                                 }
1009                                 /* Suspend the program. Inform the user */
1010                                 snprintf(string, sizeof string,
1011                                     "%c^Z [suspend ssh]\r\n", escape_char);
1012                                 buffer_append(berr, string, strlen(string));
1013
1014                                 /* Restore terminal modes and suspend. */
1015                                 client_suspend_self(bin, bout, berr);
1016
1017                                 /* We have been continued. */
1018                                 continue;
1019
1020                         case 'B':
1021                                 if (compat20) {
1022                                         snprintf(string, sizeof string,
1023                                             "%cB\r\n", escape_char);
1024                                         buffer_append(berr, string,
1025                                             strlen(string));
1026                                         channel_request_start(session_ident,
1027                                             "break", 0);
1028                                         packet_put_int(1000);
1029                                         packet_send();
1030                                 }
1031                                 continue;
1032
1033                         case 'R':
1034                                 if (compat20) {
1035                                         if (datafellows & SSH_BUG_NOREKEY)
1036                                                 logit("Server does not "
1037                                                     "support re-keying");
1038                                         else
1039                                                 need_rekeying = 1;
1040                                 }
1041                                 continue;
1042
1043                         case '&':
1044                                 if (c && c->ctl_chan != -1)
1045                                         goto noescape;
1046                                 /*
1047                                  * Detach the program (continue to serve
1048                                  * connections, but put in background and no
1049                                  * more new connections).
1050                                  */
1051                                 /* Restore tty modes. */
1052                                 leave_raw_mode(force_tty_flag);
1053
1054                                 /* Stop listening for new connections. */
1055                                 channel_stop_listening();
1056
1057                                 snprintf(string, sizeof string,
1058                                     "%c& [backgrounded]\n", escape_char);
1059                                 buffer_append(berr, string, strlen(string));
1060
1061                                 /* Fork into background. */
1062                                 pid = fork();
1063                                 if (pid < 0) {
1064                                         error("fork: %.100s", strerror(errno));
1065                                         continue;
1066                                 }
1067                                 if (pid != 0) { /* This is the parent. */
1068                                         /* The parent just exits. */
1069                                         exit(0);
1070                                 }
1071                                 /* The child continues serving connections. */
1072                                 if (compat20) {
1073                                         buffer_append(bin, "\004", 1);
1074                                         /* fake EOF on stdin */
1075                                         return -1;
1076                                 } else if (!stdin_eof) {
1077                                         /*
1078                                          * Sending SSH_CMSG_EOF alone does not
1079                                          * always appear to be enough.  So we
1080                                          * try to send an EOF character first.
1081                                          */
1082                                         packet_start(SSH_CMSG_STDIN_DATA);
1083                                         packet_put_string("\004", 1);
1084                                         packet_send();
1085                                         /* Close stdin. */
1086                                         stdin_eof = 1;
1087                                         if (buffer_len(bin) == 0) {
1088                                                 packet_start(SSH_CMSG_EOF);
1089                                                 packet_send();
1090                                         }
1091                                 }
1092                                 continue;
1093
1094                         case '?':
1095                                 if (c && c->ctl_chan != -1) {
1096                                         snprintf(string, sizeof string,
1097 "%c?\r\n\
1098 Supported escape sequences:\r\n\
1099   %c.  - terminate session\r\n\
1100   %cB  - send a BREAK to the remote system\r\n\
1101   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1102   %c#  - list forwarded connections\r\n\
1103   %c?  - this message\r\n\
1104   %c%c  - send the escape character by typing it twice\r\n\
1105 (Note that escapes are only recognized immediately after newline.)\r\n",
1106                                             escape_char, escape_char,
1107                                             escape_char, escape_char,
1108                                             escape_char, escape_char,
1109                                             escape_char, escape_char);
1110                                 } else {
1111                                         snprintf(string, sizeof string,
1112 "%c?\r\n\
1113 Supported escape sequences:\r\n\
1114   %c.  - terminate connection (and any multiplexed sessions)\r\n\
1115   %cB  - send a BREAK to the remote system\r\n\
1116   %cC  - open a command line\r\n\
1117   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1118   %c^Z - suspend ssh\r\n\
1119   %c#  - list forwarded connections\r\n\
1120   %c&  - background ssh (when waiting for connections to terminate)\r\n\
1121   %c?  - this message\r\n\
1122   %c%c  - send the escape character by typing it twice\r\n\
1123 (Note that escapes are only recognized immediately after newline.)\r\n",
1124                                             escape_char, escape_char,
1125                                             escape_char, escape_char,
1126                                             escape_char, escape_char,
1127                                             escape_char, escape_char,
1128                                             escape_char, escape_char,
1129                                             escape_char);
1130                                 }
1131                                 buffer_append(berr, string, strlen(string));
1132                                 continue;
1133
1134                         case '#':
1135                                 snprintf(string, sizeof string, "%c#\r\n",
1136                                     escape_char);
1137                                 buffer_append(berr, string, strlen(string));
1138                                 s = channel_open_message();
1139                                 buffer_append(berr, s, strlen(s));
1140                                 xfree(s);
1141                                 continue;
1142
1143                         case 'C':
1144                                 if (c && c->ctl_chan != -1)
1145                                         goto noescape;
1146                                 process_cmdline();
1147                                 continue;
1148
1149                         default:
1150                                 if (ch != escape_char) {
1151                                         buffer_put_char(bin, escape_char);
1152                                         bytes++;
1153                                 }
1154                                 /* Escaped characters fall through here */
1155                                 break;
1156                         }
1157                 } else {
1158                         /*
1159                          * The previous character was not an escape char.
1160                          * Check if this is an escape.
1161                          */
1162                         if (last_was_cr && ch == escape_char) {
1163                                 /*
1164                                  * It is. Set the flag and continue to
1165                                  * next character.
1166                                  */
1167                                 *escape_pendingp = 1;
1168                                 continue;
1169                         }
1170                 }
1171
1172                 /*
1173                  * Normal character.  Record whether it was a newline,
1174                  * and append it to the buffer.
1175                  */
1176                 last_was_cr = (ch == '\r' || ch == '\n');
1177                 buffer_put_char(bin, ch);
1178                 bytes++;
1179         }
1180         return bytes;
1181 }
1182
1183 static void
1184 client_process_input(fd_set *readset)
1185 {
1186         int len;
1187         char buf[SSH_IOBUFSZ];
1188
1189         /* Read input from stdin. */
1190         if (FD_ISSET(fileno(stdin), readset)) {
1191                 /* Read as much as possible. */
1192                 len = read(fileno(stdin), buf, sizeof(buf));
1193                 if (len < 0 &&
1194                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1195                         return;         /* we'll try again later */
1196                 if (len <= 0) {
1197                         /*
1198                          * Received EOF or error.  They are treated
1199                          * similarly, except that an error message is printed
1200                          * if it was an error condition.
1201                          */
1202                         if (len < 0) {
1203                                 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1204                                     strerror(errno));
1205                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1206                         }
1207                         /* Mark that we have seen EOF. */
1208                         stdin_eof = 1;
1209                         /*
1210                          * Send an EOF message to the server unless there is
1211                          * data in the buffer.  If there is data in the
1212                          * buffer, no message will be sent now.  Code
1213                          * elsewhere will send the EOF when the buffer
1214                          * becomes empty if stdin_eof is set.
1215                          */
1216                         if (buffer_len(&stdin_buffer) == 0) {
1217                                 packet_start(SSH_CMSG_EOF);
1218                                 packet_send();
1219                         }
1220                 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1221                         /*
1222                          * Normal successful read, and no escape character.
1223                          * Just append the data to buffer.
1224                          */
1225                         buffer_append(&stdin_buffer, buf, len);
1226                 } else {
1227                         /*
1228                          * Normal, successful read.  But we have an escape
1229                          * character and have to process the characters one
1230                          * by one.
1231                          */
1232                         if (process_escapes(NULL, &stdin_buffer,
1233                             &stdout_buffer, &stderr_buffer, buf, len) == -1)
1234                                 return;
1235                 }
1236         }
1237 }
1238
1239 static void
1240 client_process_output(fd_set *writeset)
1241 {
1242         int len;
1243         char buf[100];
1244
1245         /* Write buffered output to stdout. */
1246         if (FD_ISSET(fileno(stdout), writeset)) {
1247                 /* Write as much data as possible. */
1248                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1249                     buffer_len(&stdout_buffer));
1250                 if (len <= 0) {
1251                         if (errno == EINTR || errno == EAGAIN ||
1252                             errno == EWOULDBLOCK)
1253                                 len = 0;
1254                         else {
1255                                 /*
1256                                  * An error or EOF was encountered.  Put an
1257                                  * error message to stderr buffer.
1258                                  */
1259                                 snprintf(buf, sizeof buf,
1260                                     "write stdout: %.50s\r\n", strerror(errno));
1261                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1262                                 quit_pending = 1;
1263                                 return;
1264                         }
1265                 }
1266                 /* Consume printed data from the buffer. */
1267                 buffer_consume(&stdout_buffer, len);
1268         }
1269         /* Write buffered output to stderr. */
1270         if (FD_ISSET(fileno(stderr), writeset)) {
1271                 /* Write as much data as possible. */
1272                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1273                     buffer_len(&stderr_buffer));
1274                 if (len <= 0) {
1275                         if (errno == EINTR || errno == EAGAIN ||
1276                             errno == EWOULDBLOCK)
1277                                 len = 0;
1278                         else {
1279                                 /*
1280                                  * EOF or error, but can't even print
1281                                  * error message.
1282                                  */
1283                                 quit_pending = 1;
1284                                 return;
1285                         }
1286                 }
1287                 /* Consume printed characters from the buffer. */
1288                 buffer_consume(&stderr_buffer, len);
1289         }
1290 }
1291
1292 /*
1293  * Get packets from the connection input buffer, and process them as long as
1294  * there are packets available.
1295  *
1296  * Any unknown packets received during the actual
1297  * session cause the session to terminate.  This is
1298  * intended to make debugging easier since no
1299  * confirmations are sent.  Any compatible protocol
1300  * extensions must be negotiated during the
1301  * preparatory phase.
1302  */
1303
1304 static void
1305 client_process_buffered_input_packets(void)
1306 {
1307         dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1308             compat20 ? xxx_kex : NULL);
1309 }
1310
1311 /* scan buf[] for '~' before sending data to the peer */
1312
1313 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1314 void *
1315 client_new_escape_filter_ctx(int escape_char)
1316 {
1317         struct escape_filter_ctx *ret;
1318
1319         ret = xmalloc(sizeof(*ret));
1320         ret->escape_pending = 0;
1321         ret->escape_char = escape_char;
1322         return (void *)ret;
1323 }
1324
1325 /* Free the escape filter context on channel free */
1326 void
1327 client_filter_cleanup(int cid, void *ctx)
1328 {
1329         xfree(ctx);
1330 }
1331
1332 int
1333 client_simple_escape_filter(Channel *c, char *buf, int len)
1334 {
1335         if (c->extended_usage != CHAN_EXTENDED_WRITE)
1336                 return 0;
1337
1338         return process_escapes(c, &c->input, &c->output, &c->extended,
1339             buf, len);
1340 }
1341
1342 static void
1343 client_channel_closed(int id, void *arg)
1344 {
1345         channel_cancel_cleanup(id);
1346         session_closed = 1;
1347         leave_raw_mode(force_tty_flag);
1348 }
1349
1350 /*
1351  * Implements the interactive session with the server.  This is called after
1352  * the user has been authenticated, and a command has been started on the
1353  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1354  * used as an escape character for terminating or suspending the session.
1355  */
1356
1357 int
1358 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1359 {
1360         fd_set *readset = NULL, *writeset = NULL;
1361         double start_time, total_time;
1362         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1363         u_int64_t ibytes, obytes;
1364         u_int nalloc = 0;
1365         char buf[100];
1366
1367         debug("Entering interactive session.");
1368
1369         start_time = get_current_time();
1370
1371         /* Initialize variables. */
1372         escape_pending1 = 0;
1373         last_was_cr = 1;
1374         exit_status = -1;
1375         stdin_eof = 0;
1376         buffer_high = 64 * 1024;
1377         connection_in = packet_get_connection_in();
1378         connection_out = packet_get_connection_out();
1379         max_fd = MAX(connection_in, connection_out);
1380
1381         if (!compat20) {
1382                 /* enable nonblocking unless tty */
1383                 if (!isatty(fileno(stdin)))
1384                         set_nonblock(fileno(stdin));
1385                 if (!isatty(fileno(stdout)))
1386                         set_nonblock(fileno(stdout));
1387                 if (!isatty(fileno(stderr)))
1388                         set_nonblock(fileno(stderr));
1389                 max_fd = MAX(max_fd, fileno(stdin));
1390                 max_fd = MAX(max_fd, fileno(stdout));
1391                 max_fd = MAX(max_fd, fileno(stderr));
1392         }
1393         quit_pending = 0;
1394         escape_char1 = escape_char_arg;
1395
1396         /* Initialize buffers. */
1397         buffer_init(&stdin_buffer);
1398         buffer_init(&stdout_buffer);
1399         buffer_init(&stderr_buffer);
1400
1401         client_init_dispatch();
1402
1403         /*
1404          * Set signal handlers, (e.g. to restore non-blocking mode)
1405          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1406          */
1407         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1408                 signal(SIGHUP, signal_handler);
1409         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1410                 signal(SIGINT, signal_handler);
1411         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1412                 signal(SIGQUIT, signal_handler);
1413         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1414                 signal(SIGTERM, signal_handler);
1415         signal(SIGWINCH, window_change_handler);
1416
1417         if (have_pty)
1418                 enter_raw_mode(force_tty_flag);
1419
1420         if (compat20) {
1421                 session_ident = ssh2_chan_id;
1422                 if (escape_char_arg != SSH_ESCAPECHAR_NONE)
1423                         channel_register_filter(session_ident,
1424                             client_simple_escape_filter, NULL,
1425                             client_filter_cleanup,
1426                             client_new_escape_filter_ctx(escape_char_arg));
1427                 if (session_ident != -1)
1428                         channel_register_cleanup(session_ident,
1429                             client_channel_closed, 0);
1430         } else {
1431                 /* Check if we should immediately send eof on stdin. */
1432                 client_check_initial_eof_on_stdin();
1433         }
1434
1435         /* Main loop of the client for the interactive session mode. */
1436         while (!quit_pending) {
1437
1438                 /* Process buffered packets sent by the server. */
1439                 client_process_buffered_input_packets();
1440
1441                 if (compat20 && session_closed && !channel_still_open())
1442                         break;
1443
1444                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1445
1446                 if (rekeying) {
1447                         debug("rekeying in progress");
1448                 } else {
1449                         /*
1450                          * Make packets of buffered stdin data, and buffer
1451                          * them for sending to the server.
1452                          */
1453                         if (!compat20)
1454                                 client_make_packets_from_stdin_data();
1455
1456                         /*
1457                          * Make packets from buffered channel data, and
1458                          * enqueue them for sending to the server.
1459                          */
1460                         if (packet_not_very_much_data_to_write())
1461                                 channel_output_poll();
1462
1463                         /*
1464                          * Check if the window size has changed, and buffer a
1465                          * message about it to the server if so.
1466                          */
1467                         client_check_window_change();
1468
1469                         if (quit_pending)
1470                                 break;
1471                 }
1472                 /*
1473                  * Wait until we have something to do (something becomes
1474                  * available on one of the descriptors).
1475                  */
1476                 max_fd2 = max_fd;
1477                 client_wait_until_can_do_something(&readset, &writeset,
1478                     &max_fd2, &nalloc, rekeying);
1479
1480                 if (quit_pending)
1481                         break;
1482
1483                 /* Do channel operations unless rekeying in progress. */
1484                 if (!rekeying) {
1485                         channel_after_select(readset, writeset);
1486                         if (need_rekeying || packet_need_rekeying()) {
1487                                 debug("need rekeying");
1488                                 xxx_kex->done = 0;
1489                                 kex_send_kexinit(xxx_kex);
1490                                 need_rekeying = 0;
1491                         }
1492                 }
1493
1494                 /* Buffer input from the connection.  */
1495                 client_process_net_input(readset);
1496
1497                 if (quit_pending)
1498                         break;
1499
1500                 if (!compat20) {
1501                         /* Buffer data from stdin */
1502                         client_process_input(readset);
1503                         /*
1504                          * Process output to stdout and stderr.  Output to
1505                          * the connection is processed elsewhere (above).
1506                          */
1507                         client_process_output(writeset);
1508                 }
1509
1510                 if (session_resumed) {
1511                         connection_in = packet_get_connection_in();
1512                         connection_out = packet_get_connection_out();
1513                         max_fd = MAX(max_fd, connection_out);
1514                         max_fd = MAX(max_fd, connection_in);
1515                         session_resumed = 0;
1516                 }
1517
1518                 /*
1519                  * Send as much buffered packet data as possible to the
1520                  * sender.
1521                  */
1522                 if (FD_ISSET(connection_out, writeset))
1523                         packet_write_poll();
1524
1525                 /*
1526                  * If we are a backgrounded control master, and the
1527                  * timeout has expired without any active client
1528                  * connections, then quit.
1529                  */
1530                 if (control_persist_exit_time > 0) {
1531                         if (time(NULL) >= control_persist_exit_time) {
1532                                 debug("ControlPersist timeout expired");
1533                                 break;
1534                         }
1535                 }
1536         }
1537         if (readset)
1538                 xfree(readset);
1539         if (writeset)
1540                 xfree(writeset);
1541
1542         /* Terminate the session. */
1543
1544         /* Stop watching for window change. */
1545         signal(SIGWINCH, SIG_DFL);
1546
1547         if (compat20) {
1548                 packet_start(SSH2_MSG_DISCONNECT);
1549                 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1550                 packet_put_cstring("disconnected by user");
1551                 packet_put_cstring(""); /* language tag */
1552                 packet_send();
1553                 packet_write_wait();
1554         }
1555
1556         channel_free_all();
1557
1558         if (have_pty)
1559                 leave_raw_mode(force_tty_flag);
1560
1561         /* restore blocking io */
1562         if (!isatty(fileno(stdin)))
1563                 unset_nonblock(fileno(stdin));
1564         if (!isatty(fileno(stdout)))
1565                 unset_nonblock(fileno(stdout));
1566         if (!isatty(fileno(stderr)))
1567                 unset_nonblock(fileno(stderr));
1568
1569         /*
1570          * If there was no shell or command requested, there will be no remote
1571          * exit status to be returned.  In that case, clear error code if the
1572          * connection was deliberately terminated at this end.
1573          */
1574         if (no_shell_flag && received_signal == SIGTERM) {
1575                 received_signal = 0;
1576                 exit_status = 0;
1577         }
1578
1579         if (received_signal)
1580                 fatal("Killed by signal %d.", (int) received_signal);
1581
1582         /*
1583          * In interactive mode (with pseudo tty) display a message indicating
1584          * that the connection has been closed.
1585          */
1586         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1587                 snprintf(buf, sizeof buf,
1588                     "Connection to %.64s closed.\r\n", host);
1589                 buffer_append(&stderr_buffer, buf, strlen(buf));
1590         }
1591
1592         /* Output any buffered data for stdout. */
1593         if (buffer_len(&stdout_buffer) > 0) {
1594                 len = atomicio(vwrite, fileno(stdout),
1595                     buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer));
1596                 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer))
1597                         error("Write failed flushing stdout buffer.");
1598                 else
1599                         buffer_consume(&stdout_buffer, len);
1600         }
1601
1602         /* Output any buffered data for stderr. */
1603         if (buffer_len(&stderr_buffer) > 0) {
1604                 len = atomicio(vwrite, fileno(stderr),
1605                     buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer));
1606                 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer))
1607                         error("Write failed flushing stderr buffer.");
1608                 else
1609                         buffer_consume(&stderr_buffer, len);
1610         }
1611
1612         /* Clear and free any buffers. */
1613         memset(buf, 0, sizeof(buf));
1614         buffer_free(&stdin_buffer);
1615         buffer_free(&stdout_buffer);
1616         buffer_free(&stderr_buffer);
1617
1618         /* Report bytes transferred, and transfer rates. */
1619         total_time = get_current_time() - start_time;
1620         packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
1621         packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1622         verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1623             (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1624         if (total_time > 0)
1625                 verbose("Bytes per second: sent %.1f, received %.1f",
1626                     obytes / total_time, ibytes / total_time);
1627         /* Return the exit status of the program. */
1628         debug("Exit status %d", exit_status);
1629         return exit_status;
1630 }
1631
1632 /*********/
1633
1634 static void
1635 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1636 {
1637         u_int data_len;
1638         char *data = packet_get_string(&data_len);
1639         packet_check_eom();
1640         buffer_append(&stdout_buffer, data, data_len);
1641         memset(data, 0, data_len);
1642         xfree(data);
1643 }
1644 static void
1645 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1646 {
1647         u_int data_len;
1648         char *data = packet_get_string(&data_len);
1649         packet_check_eom();
1650         buffer_append(&stderr_buffer, data, data_len);
1651         memset(data, 0, data_len);
1652         xfree(data);
1653 }
1654 static void
1655 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1656 {
1657         exit_status = packet_get_int();
1658         packet_check_eom();
1659         /* Acknowledge the exit. */
1660         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1661         packet_send();
1662         /*
1663          * Must wait for packet to be sent since we are
1664          * exiting the loop.
1665          */
1666         packet_write_wait();
1667         /* Flag that we want to exit. */
1668         quit_pending = 1;
1669 }
1670 static void
1671 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1672 {
1673         Channel *c = NULL;
1674         int remote_id, sock;
1675
1676         /* Read the remote channel number from the message. */
1677         remote_id = packet_get_int();
1678         packet_check_eom();
1679
1680         /*
1681          * Get a connection to the local authentication agent (this may again
1682          * get forwarded).
1683          */
1684         sock = ssh_get_authentication_socket();
1685
1686         /*
1687          * If we could not connect the agent, send an error message back to
1688          * the server. This should never happen unless the agent dies,
1689          * because authentication forwarding is only enabled if we have an
1690          * agent.
1691          */
1692         if (sock >= 0) {
1693                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1694                     -1, 0, 0, 0, "authentication agent connection", 1);
1695                 c->remote_id = remote_id;
1696                 c->force_drain = 1;
1697         }
1698         if (c == NULL) {
1699                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1700                 packet_put_int(remote_id);
1701         } else {
1702                 /* Send a confirmation to the remote host. */
1703                 debug("Forwarding authentication connection.");
1704                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1705                 packet_put_int(remote_id);
1706                 packet_put_int(c->self);
1707         }
1708         packet_send();
1709 }
1710
1711 static Channel *
1712 client_request_forwarded_tcpip(const char *request_type, int rchan)
1713 {
1714         Channel *c = NULL;
1715         char *listen_address, *originator_address;
1716         u_short listen_port, originator_port;
1717
1718         /* Get rest of the packet */
1719         listen_address = packet_get_string(NULL);
1720         listen_port = packet_get_int();
1721         originator_address = packet_get_string(NULL);
1722         originator_port = packet_get_int();
1723         packet_check_eom();
1724
1725         debug("client_request_forwarded_tcpip: listen %s port %d, "
1726             "originator %s port %d", listen_address, listen_port,
1727             originator_address, originator_port);
1728
1729         c = channel_connect_by_listen_address(listen_port,
1730             "forwarded-tcpip", originator_address);
1731
1732         xfree(originator_address);
1733         xfree(listen_address);
1734         return c;
1735 }
1736
1737 static Channel *
1738 client_request_x11(const char *request_type, int rchan)
1739 {
1740         Channel *c = NULL;
1741         char *originator;
1742         u_short originator_port;
1743         int sock;
1744
1745         if (!options.forward_x11) {
1746                 error("Warning: ssh server tried X11 forwarding.");
1747                 error("Warning: this is probably a break-in attempt by a "
1748                     "malicious server.");
1749                 return NULL;
1750         }
1751         if (x11_refuse_time != 0 && time(NULL) >= x11_refuse_time) {
1752                 verbose("Rejected X11 connection after ForwardX11Timeout "
1753                     "expired");
1754                 return NULL;
1755         }
1756         originator = packet_get_string(NULL);
1757         if (datafellows & SSH_BUG_X11FWD) {
1758                 debug2("buggy server: x11 request w/o originator_port");
1759                 originator_port = 0;
1760         } else {
1761                 originator_port = packet_get_int();
1762         }
1763         packet_check_eom();
1764         /* XXX check permission */
1765         debug("client_request_x11: request from %s %d", originator,
1766             originator_port);
1767         xfree(originator);
1768         sock = x11_connect_display();
1769         if (sock < 0)
1770                 return NULL;
1771         c = channel_new("x11",
1772             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1773             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1774         c->force_drain = 1;
1775         return c;
1776 }
1777
1778 static Channel *
1779 client_request_agent(const char *request_type, int rchan)
1780 {
1781         Channel *c = NULL;
1782         int sock;
1783
1784         if (!options.forward_agent) {
1785                 error("Warning: ssh server tried agent forwarding.");
1786                 error("Warning: this is probably a break-in attempt by a "
1787                     "malicious server.");
1788                 return NULL;
1789         }
1790         sock = ssh_get_authentication_socket();
1791         if (sock < 0)
1792                 return NULL;
1793         c = channel_new("authentication agent connection",
1794             SSH_CHANNEL_OPEN, sock, sock, -1,
1795             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1796             "authentication agent connection", 1);
1797         c->force_drain = 1;
1798         return c;
1799 }
1800
1801 int
1802 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1803 {
1804         Channel *c;
1805         int fd;
1806
1807         if (tun_mode == SSH_TUNMODE_NO)
1808                 return 0;
1809
1810         if (!compat20) {
1811                 error("Tunnel forwarding is not supported for protocol 1");
1812                 return -1;
1813         }
1814
1815         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1816
1817         /* Open local tunnel device */
1818         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1819                 error("Tunnel device open failed.");
1820                 return -1;
1821         }
1822
1823         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1824             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1825         c->datagram = 1;
1826
1827 #if defined(SSH_TUN_FILTER)
1828         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1829                 channel_register_filter(c->self, sys_tun_infilter,
1830                     sys_tun_outfilter, NULL, NULL);
1831 #endif
1832
1833         packet_start(SSH2_MSG_CHANNEL_OPEN);
1834         packet_put_cstring("tun@openssh.com");
1835         packet_put_int(c->self);
1836         packet_put_int(c->local_window_max);
1837         packet_put_int(c->local_maxpacket);
1838         packet_put_int(tun_mode);
1839         packet_put_int(remote_tun);
1840         packet_send();
1841
1842         return 0;
1843 }
1844
1845 /* XXXX move to generic input handler */
1846 static void
1847 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1848 {
1849         Channel *c = NULL;
1850         char *ctype;
1851         int rchan;
1852         u_int rmaxpack, rwindow, len;
1853
1854         ctype = packet_get_string(&len);
1855         rchan = packet_get_int();
1856         rwindow = packet_get_int();
1857         rmaxpack = packet_get_int();
1858
1859         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1860             ctype, rchan, rwindow, rmaxpack);
1861
1862         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1863                 c = client_request_forwarded_tcpip(ctype, rchan);
1864         } else if (strcmp(ctype, "x11") == 0) {
1865                 c = client_request_x11(ctype, rchan);
1866         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1867                 c = client_request_agent(ctype, rchan);
1868         }
1869 /* XXX duplicate : */
1870         if (c != NULL) {
1871                 debug("confirm %s", ctype);
1872                 c->remote_id = rchan;
1873                 c->remote_window = rwindow;
1874                 c->remote_maxpacket = rmaxpack;
1875                 if (c->type != SSH_CHANNEL_CONNECTING) {
1876                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1877                         packet_put_int(c->remote_id);
1878                         packet_put_int(c->self);
1879                         packet_put_int(c->local_window);
1880                         packet_put_int(c->local_maxpacket);
1881                         packet_send();
1882                 }
1883         } else {
1884                 debug("failure %s", ctype);
1885                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1886                 packet_put_int(rchan);
1887                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1888                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1889                         packet_put_cstring("open failed");
1890                         packet_put_cstring("");
1891                 }
1892                 packet_send();
1893         }
1894         xfree(ctype);
1895 }
1896 static void
1897 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1898 {
1899         Channel *c = NULL;
1900         int exitval, id, reply, success = 0;
1901         char *rtype;
1902
1903         id = packet_get_int();
1904         rtype = packet_get_string(NULL);
1905         reply = packet_get_char();
1906
1907         debug("client_input_channel_req: channel %d rtype %s reply %d",
1908             id, rtype, reply);
1909
1910         if (id == -1) {
1911                 error("client_input_channel_req: request for channel -1");
1912         } else if ((c = channel_lookup(id)) == NULL) {
1913                 error("client_input_channel_req: channel %d: "
1914                     "unknown channel", id);
1915         } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1916                 packet_check_eom();
1917                 chan_rcvd_eow(c);
1918         } else if (strcmp(rtype, "exit-status") == 0) {
1919                 exitval = packet_get_int();
1920                 if (c->ctl_chan != -1) {
1921                         mux_exit_message(c, exitval);
1922                         success = 1;
1923                 } else if (id == session_ident) {
1924                         /* Record exit value of local session */
1925                         success = 1;
1926                         exit_status = exitval;
1927                 } else {
1928                         /* Probably for a mux channel that has already closed */
1929                         debug("%s: no sink for exit-status on channel %d",
1930                             __func__, id);
1931                 }
1932                 packet_check_eom();
1933         }
1934         if (reply && c != NULL) {
1935                 packet_start(success ?
1936                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1937                 packet_put_int(c->remote_id);
1938                 packet_send();
1939         }
1940         xfree(rtype);
1941 }
1942 static void
1943 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1944 {
1945         char *rtype;
1946         int want_reply;
1947         int success = 0;
1948
1949         rtype = packet_get_string(NULL);
1950         want_reply = packet_get_char();
1951         debug("client_input_global_request: rtype %s want_reply %d",
1952             rtype, want_reply);
1953         if (want_reply) {
1954                 packet_start(success ?
1955                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1956                 packet_send();
1957                 packet_write_wait();
1958         }
1959         xfree(rtype);
1960 }
1961
1962 void
1963 client_session2_setup(int id, int want_tty, int want_subsystem,
1964     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
1965 {
1966         int len;
1967         Channel *c = NULL;
1968
1969         debug2("%s: id %d", __func__, id);
1970
1971         if ((c = channel_lookup(id)) == NULL)
1972                 fatal("client_session2_setup: channel %d: unknown channel", id);
1973
1974         packet_set_interactive(want_tty,
1975             options.ip_qos_interactive, options.ip_qos_bulk);
1976
1977         if (want_tty) {
1978                 struct winsize ws;
1979
1980                 /* Store window size in the packet. */
1981                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1982                         memset(&ws, 0, sizeof(ws));
1983
1984                 channel_request_start(id, "pty-req", 1);
1985                 client_expect_confirm(id, "PTY allocation", 1);
1986                 packet_put_cstring(term != NULL ? term : "");
1987                 packet_put_int((u_int)ws.ws_col);
1988                 packet_put_int((u_int)ws.ws_row);
1989                 packet_put_int((u_int)ws.ws_xpixel);
1990                 packet_put_int((u_int)ws.ws_ypixel);
1991                 if (tiop == NULL)
1992                         tiop = get_saved_tio();
1993                 tty_make_modes(-1, tiop);
1994                 packet_send();
1995                 /* XXX wait for reply */
1996                 c->client_tty = 1;
1997         }
1998
1999         /* Transfer any environment variables from client to server */
2000         if (options.num_send_env != 0 && env != NULL) {
2001                 int i, j, matched;
2002                 char *name, *val;
2003
2004                 debug("Sending environment.");
2005                 for (i = 0; env[i] != NULL; i++) {
2006                         /* Split */
2007                         name = xstrdup(env[i]);
2008                         if ((val = strchr(name, '=')) == NULL) {
2009                                 xfree(name);
2010                                 continue;
2011                         }
2012                         *val++ = '\0';
2013
2014                         matched = 0;
2015                         for (j = 0; j < options.num_send_env; j++) {
2016                                 if (match_pattern(name, options.send_env[j])) {
2017                                         matched = 1;
2018                                         break;
2019                                 }
2020                         }
2021                         if (!matched) {
2022                                 debug3("Ignored env %s", name);
2023                                 xfree(name);
2024                                 continue;
2025                         }
2026
2027                         debug("Sending env %s = %s", name, val);
2028                         channel_request_start(id, "env", 0);
2029                         packet_put_cstring(name);
2030                         packet_put_cstring(val);
2031                         packet_send();
2032                         xfree(name);
2033                 }
2034         }
2035
2036         len = buffer_len(cmd);
2037         if (len > 0) {
2038                 if (len > 900)
2039                         len = 900;
2040                 if (want_subsystem) {
2041                         debug("Sending subsystem: %.*s",
2042                             len, (u_char*)buffer_ptr(cmd));
2043                         channel_request_start(id, "subsystem", 1);
2044                         client_expect_confirm(id, "subsystem", 1);
2045                 } else {
2046                         debug("Sending command: %.*s",
2047                             len, (u_char*)buffer_ptr(cmd));
2048                         channel_request_start(id, "exec", 1);
2049                         client_expect_confirm(id, "exec", 1);
2050                 }
2051                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2052                 packet_send();
2053         } else {
2054                 channel_request_start(id, "shell", 1);
2055                 client_expect_confirm(id, "shell", 1);
2056                 packet_send();
2057         }
2058 }
2059
2060 static void
2061 client_init_dispatch_20(void)
2062 {
2063         dispatch_init(&dispatch_protocol_error);
2064
2065         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2066         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2067         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2068         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2069         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2070         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2071         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2072         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2073         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2074         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2075         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2076         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2077
2078         /* rekeying */
2079         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2080
2081         /* global request reply messages */
2082         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2083         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2084 }
2085
2086 static void
2087 client_init_dispatch_13(void)
2088 {
2089         dispatch_init(NULL);
2090         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2091         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2092         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2093         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2094         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2095         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2096         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2097         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2098         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2099
2100         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2101             &client_input_agent_open : &deny_input_open);
2102         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2103             &x11_input_open : &deny_input_open);
2104 }
2105
2106 static void
2107 client_init_dispatch_15(void)
2108 {
2109         client_init_dispatch_13();
2110         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2111         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2112 }
2113
2114 static void
2115 client_init_dispatch(void)
2116 {
2117         if (compat20)
2118                 client_init_dispatch_20();
2119         else if (compat13)
2120                 client_init_dispatch_13();
2121         else
2122                 client_init_dispatch_15();
2123 }
2124
2125 /* client specific fatal cleanup */
2126 void
2127 cleanup_exit(int i)
2128 {
2129         leave_raw_mode(force_tty_flag);
2130         leave_non_blocking();
2131         if (options.control_path != NULL && muxserver_sock != -1)
2132                 unlink(options.control_path);
2133         ssh_kill_proxy_command();
2134         _exit(i);
2135 }