crypto/openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.275 2015/07/10 06:21:53 markus 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/param.h>  /* MIN MAX */
  65 #include <sys/types.h>
  66 #include <sys/ioctl.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 #include <limits.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 "myproposal.h"
 104 #include "log.h"
 105 #include "misc.h"
 106 #include "readconf.h"
 107 #include "clientloop.h"
 108 #include "sshconnect.h"
 109 #include "authfd.h"
 110 #include "atomicio.h"
 111 #include "sshpty.h"
 112 #include "match.h"
 113 #include "msg.h"
 114 #include "roaming.h"
 115 #include "ssherr.h"
 116 #include "hostfile.h"
 117
 118 /* import options */
 119 extern Options options;
 120
 121 /* Flag indicating that stdin should be redirected from /dev/null. */
 122 extern int stdin_null_flag;
 123
 124 /* Flag indicating that no shell has been requested */
 125 extern int no_shell_flag;
 126
 127 /* Control socket */
 128 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
 129
 130 /*
 131  * Name of the host we are connecting to.  This is the name given on the
 132  * command line, or the HostName specified for the user-supplied name in a
 133  * configuration file.
 134  */
 135 extern char *host;
 136
 137 /*
 138  * Flag to indicate that we have received a window change signal which has
 139  * not yet been processed.  This will cause a message indicating the new
 140  * window size to be sent to the server a little later.  This is volatile
 141  * because this is updated in a signal handler.
 142  */
 143 static volatile sig_atomic_t received_window_change_signal = 0;
 144 static volatile sig_atomic_t received_signal = 0;
 145
 146 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 147 static int in_non_blocking_mode = 0;
 148
 149 /* Time when backgrounded control master using ControlPersist should exit */
 150 static time_t control_persist_exit_time = 0;
 151
 152 /* Common data for the client loop code. */
 153 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 154 static int escape_char1;        /* Escape character. (proto1 only) */
 155 static int escape_pending1;     /* Last character was an escape (proto1 only) */
 156 static int last_was_cr;         /* Last character was a newline. */
 157 static int exit_status;         /* Used to store the command exit status. */
 158 static int stdin_eof;           /* EOF has been encountered on stderr. */
 159 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 160 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 161 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 162 static u_int buffer_high;       /* Soft max buffer size. */
 163 static int connection_in;       /* Connection to server (input). */
 164 static int connection_out;      /* Connection to server (output). */
 165 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 166 static int session_closed;      /* In SSH2: login session closed. */
 167 static u_int x11_refuse_time;   /* If >0, refuse x11 opens after this time. */
 168
 169 static void client_init_dispatch(void);
 170 int     session_ident = -1;
 171
 172 int     session_resumed = 0;
 173
 174 /* Track escape per proto2 channel */
 175 struct escape_filter_ctx {
 176         int escape_pending;
 177         int escape_char;
 178 };
 179
 180 /* Context for channel confirmation replies */
 181 struct channel_reply_ctx {
 182         const char *request_type;
 183         int id;
 184         enum confirm_action action;
 185 };
 186
 187 /* Global request success/failure callbacks */
 188 struct global_confirm {
 189         TAILQ_ENTRY(global_confirm) entry;
 190         global_confirm_cb *cb;
 191         void *ctx;
 192         int ref_count;
 193 };
 194 TAILQ_HEAD(global_confirms, global_confirm);
 195 static struct global_confirms global_confirms =
 196     TAILQ_HEAD_INITIALIZER(global_confirms);
 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 = monotime() +
 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_VALID_DISPLAY_CHARS ":/.-_"
 286 static int
 287 client_x11_display_valid(const char *display)
 288 {
 289         size_t i, dlen;
 290
 291         dlen = strlen(display);
 292         for (i = 0; i < dlen; i++) {
 293                 if (!isalnum((u_char)display[i]) &&
 294                     strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) {
 295                         debug("Invalid character '%c' in DISPLAY", display[i]);
 296                         return 0;
 297                 }
 298         }
 299         return 1;
 300 }
 301
 302 #define SSH_X11_PROTO           "MIT-MAGIC-COOKIE-1"
 303 #define X11_TIMEOUT_SLACK       60
 304 void
 305 client_x11_get_proto(const char *display, const char *xauth_path,
 306     u_int trusted, u_int timeout, char **_proto, char **_data)
 307 {
 308         char cmd[1024];
 309         char line[512];
 310         char xdisplay[512];
 311         static char proto[512], data[512];
 312         FILE *f;
 313         int got_data = 0, generated = 0, do_unlink = 0, i;
 314         char *xauthdir, *xauthfile;
 315         struct stat st;
 316         u_int now, x11_timeout_real;
 317
 318         xauthdir = xauthfile = NULL;
 319         *_proto = proto;
 320         *_data = data;
 321         proto[0] = data[0] = '\0';
 322
 323         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 324                 debug("No xauth program.");
 325         } else if (!client_x11_display_valid(display)) {
 326                 logit("DISPLAY '%s' invalid, falling back to fake xauth data",
 327                     display);
 328         } else {
 329                 if (display == NULL) {
 330                         debug("x11_get_proto: DISPLAY not set");
 331                         return;
 332                 }
 333                 /*
 334                  * Handle FamilyLocal case where $DISPLAY does
 335                  * not match an authorization entry.  For this we
 336                  * just try "xauth list unix:displaynum.screennum".
 337                  * XXX: "localhost" match to determine FamilyLocal
 338                  *      is not perfect.
 339                  */
 340                 if (strncmp(display, "localhost:", 10) == 0) {
 341                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 342                             display + 10);
 343                         display = xdisplay;
 344                 }
 345                 if (trusted == 0) {
 346                         xauthdir = xmalloc(PATH_MAX);
 347                         xauthfile = xmalloc(PATH_MAX);
 348                         mktemp_proto(xauthdir, PATH_MAX);
 349                         /*
 350                          * The authentication cookie should briefly outlive
 351                          * ssh's willingness to forward X11 connections to
 352                          * avoid nasty fail-open behaviour in the X server.
 353                          */
 354                         if (timeout >= UINT_MAX - X11_TIMEOUT_SLACK)
 355                                 x11_timeout_real = UINT_MAX;
 356                         else
 357                                 x11_timeout_real = timeout + X11_TIMEOUT_SLACK;
 358                         if (mkdtemp(xauthdir) != NULL) {
 359                                 do_unlink = 1;
 360                                 snprintf(xauthfile, PATH_MAX, "%s/xauthfile",
 361                                     xauthdir);
 362                                 snprintf(cmd, sizeof(cmd),
 363                                     "%s -f %s generate %s " SSH_X11_PROTO
 364                                     " untrusted timeout %u 2>" _PATH_DEVNULL,
 365                                     xauth_path, xauthfile, display,
 366                                     x11_timeout_real);
 367                                 debug2("x11_get_proto: %s", cmd);
 368                                 if (x11_refuse_time == 0) {
 369                                         now = monotime() + 1;
 370                                         if (UINT_MAX - timeout < now)
 371                                                 x11_refuse_time = UINT_MAX;
 372                                         else
 373                                                 x11_refuse_time = now + timeout;
 374                                         channel_set_x11_refuse_time(
 375                                             x11_refuse_time);
 376                                 }
 377                                 if (system(cmd) == 0)
 378                                         generated = 1;
 379                         }
 380                 }
 381
 382                 /*
 383                  * When in untrusted mode, we read the cookie only if it was
 384                  * successfully generated as an untrusted one in the step
 385                  * above.
 386                  */
 387                 if (trusted || generated) {
 388                         snprintf(cmd, sizeof(cmd),
 389                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 390                             xauth_path,
 391                             generated ? "-f " : "" ,
 392                             generated ? xauthfile : "",
 393                             display);
 394                         debug2("x11_get_proto: %s", cmd);
 395                         f = popen(cmd, "r");
 396                         if (f && fgets(line, sizeof(line), f) &&
 397                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 398                                 got_data = 1;
 399                         if (f)
 400                                 pclose(f);
 401                 } else
 402                         error("Warning: untrusted X11 forwarding setup failed: "
 403                             "xauth key data not generated");
 404         }
 405
 406         if (do_unlink) {
 407                 unlink(xauthfile);
 408                 rmdir(xauthdir);
 409         }
 410         free(xauthdir);
 411         free(xauthfile);
 412
 413         /*
 414          * If we didn't get authentication data, just make up some
 415          * data.  The forwarding code will check the validity of the
 416          * response anyway, and substitute this data.  The X11
 417          * server, however, will ignore this fake data and use
 418          * whatever authentication mechanisms it was using otherwise
 419          * for the local connection.
 420          */
 421         if (!got_data) {
 422                 u_int32_t rnd = 0;
 423
 424                 logit("Warning: No xauth data; "
 425                     "using fake authentication data for X11 forwarding.");
 426                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 427                 for (i = 0; i < 16; i++) {
 428                         if (i % 4 == 0)
 429                                 rnd = arc4random();
 430                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 431                             rnd & 0xff);
 432                         rnd >>= 8;
 433                 }
 434         }
 435 }
 436
 437 /*
 438  * This is called when the interactive is entered.  This checks if there is
 439  * an EOF coming on stdin.  We must check this explicitly, as select() does
 440  * not appear to wake up when redirecting from /dev/null.
 441  */
 442
 443 static void
 444 client_check_initial_eof_on_stdin(void)
 445 {
 446         int len;
 447         char buf[1];
 448
 449         /*
 450          * If standard input is to be "redirected from /dev/null", we simply
 451          * mark that we have seen an EOF and send an EOF message to the
 452          * server. Otherwise, we try to read a single character; it appears
 453          * that for some files, such /dev/null, select() never wakes up for
 454          * read for this descriptor, which means that we never get EOF.  This
 455          * way we will get the EOF if stdin comes from /dev/null or similar.
 456          */
 457         if (stdin_null_flag) {
 458                 /* Fake EOF on stdin. */
 459                 debug("Sending eof.");
 460                 stdin_eof = 1;
 461                 packet_start(SSH_CMSG_EOF);
 462                 packet_send();
 463         } else {
 464                 enter_non_blocking();
 465
 466                 /* Check for immediate EOF on stdin. */
 467                 len = read(fileno(stdin), buf, 1);
 468                 if (len == 0) {
 469                         /*
 470                          * EOF.  Record that we have seen it and send
 471                          * EOF to server.
 472                          */
 473                         debug("Sending eof.");
 474                         stdin_eof = 1;
 475                         packet_start(SSH_CMSG_EOF);
 476                         packet_send();
 477                 } else if (len > 0) {
 478                         /*
 479                          * Got data.  We must store the data in the buffer,
 480                          * and also process it as an escape character if
 481                          * appropriate.
 482                          */
 483                         if ((u_char) buf[0] == escape_char1)
 484                                 escape_pending1 = 1;
 485                         else
 486                                 buffer_append(&stdin_buffer, buf, 1);
 487                 }
 488                 leave_non_blocking();
 489         }
 490 }
 491
 492
 493 /*
 494  * Make packets from buffered stdin data, and buffer them for sending to the
 495  * connection.
 496  */
 497
 498 static void
 499 client_make_packets_from_stdin_data(void)
 500 {
 501         u_int len;
 502
 503         /* Send buffered stdin data to the server. */
 504         while (buffer_len(&stdin_buffer) > 0 &&
 505             packet_not_very_much_data_to_write()) {
 506                 len = buffer_len(&stdin_buffer);
 507                 /* Keep the packets at reasonable size. */
 508                 if (len > packet_get_maxsize())
 509                         len = packet_get_maxsize();
 510                 packet_start(SSH_CMSG_STDIN_DATA);
 511                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 512                 packet_send();
 513                 buffer_consume(&stdin_buffer, len);
 514                 /* If we have a pending EOF, send it now. */
 515                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 516                         packet_start(SSH_CMSG_EOF);
 517                         packet_send();
 518                 }
 519         }
 520 }
 521
 522 /*
 523  * Checks if the client window has changed, and sends a packet about it to
 524  * the server if so.  The actual change is detected elsewhere (by a software
 525  * interrupt on Unix); this just checks the flag and sends a message if
 526  * appropriate.
 527  */
 528
 529 static void
 530 client_check_window_change(void)
 531 {
 532         struct winsize ws;
 533
 534         if (! received_window_change_signal)
 535                 return;
 536         /** XXX race */
 537         received_window_change_signal = 0;
 538
 539         debug2("client_check_window_change: changed");
 540
 541         if (compat20) {
 542                 channel_send_window_changes();
 543         } else {
 544                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 545                         return;
 546                 packet_start(SSH_CMSG_WINDOW_SIZE);
 547                 packet_put_int((u_int)ws.ws_row);
 548                 packet_put_int((u_int)ws.ws_col);
 549                 packet_put_int((u_int)ws.ws_xpixel);
 550                 packet_put_int((u_int)ws.ws_ypixel);
 551                 packet_send();
 552         }
 553 }
 554
 555 static int
 556 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 557 {
 558         struct global_confirm *gc;
 559
 560         if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
 561                 return 0;
 562         if (gc->cb != NULL)
 563                 gc->cb(type, seq, gc->ctx);
 564         if (--gc->ref_count <= 0) {
 565                 TAILQ_REMOVE(&global_confirms, gc, entry);
 566                 explicit_bzero(gc, sizeof(*gc));
 567                 free(gc);
 568         }
 569
 570         packet_set_alive_timeouts(0);
 571         return 0;
 572 }
 573
 574 static void
 575 server_alive_check(void)
 576 {
 577         if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
 578                 logit("Timeout, server %s not responding.", host);
 579                 cleanup_exit(255);
 580         }
 581         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 582         packet_put_cstring("keepalive@openssh.com");
 583         packet_put_char(1);     /* boolean: want reply */
 584         packet_send();
 585         /* Insert an empty placeholder to maintain ordering */
 586         client_register_global_confirm(NULL, NULL);
 587 }
 588
 589 /*
 590  * Waits until the client can do something (some data becomes available on
 591  * one of the file descriptors).
 592  */
 593 static void
 594 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 595     int *maxfdp, u_int *nallocp, int rekeying)
 596 {
 597         struct timeval tv, *tvp;
 598         int timeout_secs;
 599         time_t minwait_secs = 0, server_alive_time = 0, now = monotime();
 600         int ret;
 601
 602         /* Add any selections by the channel mechanism. */
 603         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
 604             &minwait_secs, rekeying);
 605
 606         if (!compat20) {
 607                 /* Read from the connection, unless our buffers are full. */
 608                 if (buffer_len(&stdout_buffer) < buffer_high &&
 609                     buffer_len(&stderr_buffer) < buffer_high &&
 610                     channel_not_very_much_buffered_data())
 611                         FD_SET(connection_in, *readsetp);
 612                 /*
 613                  * Read from stdin, unless we have seen EOF or have very much
 614                  * buffered data to send to the server.
 615                  */
 616                 if (!stdin_eof && packet_not_very_much_data_to_write())
 617                         FD_SET(fileno(stdin), *readsetp);
 618
 619                 /* Select stdout/stderr if have data in buffer. */
 620                 if (buffer_len(&stdout_buffer) > 0)
 621                         FD_SET(fileno(stdout), *writesetp);
 622                 if (buffer_len(&stderr_buffer) > 0)
 623                         FD_SET(fileno(stderr), *writesetp);
 624         } else {
 625                 /* channel_prepare_select could have closed the last channel */
 626                 if (session_closed && !channel_still_open() &&
 627                     !packet_have_data_to_write()) {
 628                         /* clear mask since we did not call select() */
 629                         memset(*readsetp, 0, *nallocp);
 630                         memset(*writesetp, 0, *nallocp);
 631                         return;
 632                 } else {
 633                         FD_SET(connection_in, *readsetp);
 634                 }
 635         }
 636
 637         /* Select server connection if have data to write to the server. */
 638         if (packet_have_data_to_write())
 639                 FD_SET(connection_out, *writesetp);
 640
 641         /*
 642          * Wait for something to happen.  This will suspend the process until
 643          * some selected descriptor can be read, written, or has some other
 644          * event pending, or a timeout expires.
 645          */
 646
 647         timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
 648         if (options.server_alive_interval > 0 && compat20) {
 649                 timeout_secs = options.server_alive_interval;
 650                 server_alive_time = now + options.server_alive_interval;
 651         }
 652         if (options.rekey_interval > 0 && compat20 && !rekeying)
 653                 timeout_secs = MIN(timeout_secs, packet_get_rekey_timeout());
 654         set_control_persist_exit_time();
 655         if (control_persist_exit_time > 0) {
 656                 timeout_secs = MIN(timeout_secs,
 657                         control_persist_exit_time - now);
 658                 if (timeout_secs < 0)
 659                         timeout_secs = 0;
 660         }
 661         if (minwait_secs != 0)
 662                 timeout_secs = MIN(timeout_secs, (int)minwait_secs);
 663         if (timeout_secs == INT_MAX)
 664                 tvp = NULL;
 665         else {
 666                 tv.tv_sec = timeout_secs;
 667                 tv.tv_usec = 0;
 668                 tvp = &tv;
 669         }
 670
 671         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 672         if (ret < 0) {
 673                 char buf[100];
 674
 675                 /*
 676                  * We have to clear the select masks, because we return.
 677                  * We have to return, because the mainloop checks for the flags
 678                  * set by the signal handlers.
 679                  */
 680                 memset(*readsetp, 0, *nallocp);
 681                 memset(*writesetp, 0, *nallocp);
 682
 683                 if (errno == EINTR)
 684                         return;
 685                 /* Note: we might still have data in the buffers. */
 686                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 687                 buffer_append(&stderr_buffer, buf, strlen(buf));
 688                 quit_pending = 1;
 689         } else if (ret == 0) {
 690                 /*
 691                  * Timeout.  Could have been either keepalive or rekeying.
 692                  * Keepalive we check here, rekeying is checked in clientloop.
 693                  */
 694                 if (server_alive_time != 0 && server_alive_time <= monotime())
 695                         server_alive_check();
 696         }
 697
 698 }
 699
 700 static void
 701 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 702 {
 703         /* Flush stdout and stderr buffers. */
 704         if (buffer_len(bout) > 0)
 705                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
 706                     buffer_len(bout));
 707         if (buffer_len(berr) > 0)
 708                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
 709                     buffer_len(berr));
 710
 711         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 712
 713         /*
 714          * Free (and clear) the buffer to reduce the amount of data that gets
 715          * written to swap.
 716          */
 717         buffer_free(bin);
 718         buffer_free(bout);
 719         buffer_free(berr);
 720
 721         /* Send the suspend signal to the program itself. */
 722         kill(getpid(), SIGTSTP);
 723
 724         /* Reset window sizes in case they have changed */
 725         received_window_change_signal = 1;
 726
 727         /* OK, we have been continued by the user. Reinitialize buffers. */
 728         buffer_init(bin);
 729         buffer_init(bout);
 730         buffer_init(berr);
 731
 732         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 733 }
 734
 735 static void
 736 client_process_net_input(fd_set *readset)
 737 {
 738         int len, cont = 0;
 739         char buf[SSH_IOBUFSZ];
 740
 741         /*
 742          * Read input from the server, and add any such data to the buffer of
 743          * the packet subsystem.
 744          */
 745         if (FD_ISSET(connection_in, readset)) {
 746                 /* Read as much as possible. */
 747                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 748                 if (len == 0 && cont == 0) {
 749                         /*
 750                          * Received EOF.  The remote host has closed the
 751                          * connection.
 752                          */
 753                         snprintf(buf, sizeof buf,
 754                             "Connection to %.300s closed by remote host.\r\n",
 755                             host);
 756                         buffer_append(&stderr_buffer, buf, strlen(buf));
 757                         quit_pending = 1;
 758                         return;
 759                 }
 760                 /*
 761                  * There is a kernel bug on Solaris that causes select to
 762                  * sometimes wake up even though there is no data available.
 763                  */
 764                 if (len < 0 &&
 765                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 766                         len = 0;
 767
 768                 if (len < 0) {
 769                         /*
 770                          * An error has encountered.  Perhaps there is a
 771                          * network problem.
 772                          */
 773                         snprintf(buf, sizeof buf,
 774                             "Read from remote host %.300s: %.100s\r\n",
 775                             host, strerror(errno));
 776                         buffer_append(&stderr_buffer, buf, strlen(buf));
 777                         quit_pending = 1;
 778                         return;
 779                 }
 780                 packet_process_incoming(buf, len);
 781         }
 782 }
 783
 784 static void
 785 client_status_confirm(int type, Channel *c, void *ctx)
 786 {
 787         struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
 788         char errmsg[256];
 789         int tochan;
 790
 791         /*
 792          * If a TTY was explicitly requested, then a failure to allocate
 793          * one is fatal.
 794          */
 795         if (cr->action == CONFIRM_TTY &&
 796             (options.request_tty == REQUEST_TTY_FORCE ||
 797             options.request_tty == REQUEST_TTY_YES))
 798                 cr->action = CONFIRM_CLOSE;
 799
 800         /* XXX supress on mux _client_ quietmode */
 801         tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
 802             c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
 803
 804         if (type == SSH2_MSG_CHANNEL_SUCCESS) {
 805                 debug2("%s request accepted on channel %d",
 806                     cr->request_type, c->self);
 807         } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 808                 if (tochan) {
 809                         snprintf(errmsg, sizeof(errmsg),
 810                             "%s request failed\r\n", cr->request_type);
 811                 } else {
 812                         snprintf(errmsg, sizeof(errmsg),
 813                             "%s request failed on channel %d",
 814                             cr->request_type, c->self);
 815                 }
 816                 /* If error occurred on primary session channel, then exit */
 817                 if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
 818                         fatal("%s", errmsg);
 819                 /*
 820                  * If error occurred on mux client, append to
 821                  * their stderr.
 822                  */
 823                 if (tochan) {
 824                         buffer_append(&c->extended, errmsg,
 825                             strlen(errmsg));
 826                 } else
 827                         error("%s", errmsg);
 828                 if (cr->action == CONFIRM_TTY) {
 829                         /*
 830                          * If a TTY allocation error occurred, then arrange
 831                          * for the correct TTY to leave raw mode.
 832                          */
 833                         if (c->self == session_ident)
 834                                 leave_raw_mode(0);
 835                         else
 836                                 mux_tty_alloc_failed(c);
 837                 } else if (cr->action == CONFIRM_CLOSE) {
 838                         chan_read_failed(c);
 839                         chan_write_failed(c);
 840                 }
 841         }
 842         free(cr);
 843 }
 844
 845 static void
 846 client_abandon_status_confirm(Channel *c, void *ctx)
 847 {
 848         free(ctx);
 849 }
 850
 851 void
 852 client_expect_confirm(int id, const char *request,
 853     enum confirm_action action)
 854 {
 855         struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr));
 856
 857         cr->request_type = request;
 858         cr->action = action;
 859
 860         channel_register_status_confirm(id, client_status_confirm,
 861             client_abandon_status_confirm, cr);
 862 }
 863
 864 void
 865 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
 866 {
 867         struct global_confirm *gc, *last_gc;
 868
 869         /* Coalesce identical callbacks */
 870         last_gc = TAILQ_LAST(&global_confirms, global_confirms);
 871         if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
 872                 if (++last_gc->ref_count >= INT_MAX)
 873                         fatal("%s: last_gc->ref_count = %d",
 874                             __func__, last_gc->ref_count);
 875                 return;
 876         }
 877
 878         gc = xcalloc(1, sizeof(*gc));
 879         gc->cb = cb;
 880         gc->ctx = ctx;
 881         gc->ref_count = 1;
 882         TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
 883 }
 884
 885 static void
 886 process_cmdline(void)
 887 {
 888         void (*handler)(int);
 889         char *s, *cmd;
 890         int ok, delete = 0, local = 0, remote = 0, dynamic = 0;
 891         struct Forward fwd;
 892
 893         memset(&fwd, 0, sizeof(fwd));
 894
 895         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 896         handler = signal(SIGINT, SIG_IGN);
 897         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 898         if (s == NULL)
 899                 goto out;
 900         while (isspace((u_char)*s))
 901                 s++;
 902         if (*s == '-')
 903                 s++;    /* Skip cmdline '-', if any */
 904         if (*s == '\0')
 905                 goto out;
 906
 907         if (*s == 'h' || *s == 'H' || *s == '?') {
 908                 logit("Commands:");
 909                 logit("      -L[bind_address:]port:host:hostport    "
 910                     "Request local forward");
 911                 logit("      -R[bind_address:]port:host:hostport    "
 912                     "Request remote forward");
 913                 logit("      -D[bind_address:]port                  "
 914                     "Request dynamic forward");
 915                 logit("      -KL[bind_address:]port                 "
 916                     "Cancel local forward");
 917                 logit("      -KR[bind_address:]port                 "
 918                     "Cancel remote forward");
 919                 logit("      -KD[bind_address:]port                 "
 920                     "Cancel dynamic forward");
 921                 if (!options.permit_local_command)
 922                         goto out;
 923                 logit("      !args                                  "
 924                     "Execute local command");
 925                 goto out;
 926         }
 927
 928         if (*s == '!' && options.permit_local_command) {
 929                 s++;
 930                 ssh_local_cmd(s);
 931                 goto out;
 932         }
 933
 934         if (*s == 'K') {
 935                 delete = 1;
 936                 s++;
 937         }
 938         if (*s == 'L')
 939                 local = 1;
 940         else if (*s == 'R')
 941                 remote = 1;
 942         else if (*s == 'D')
 943                 dynamic = 1;
 944         else {
 945                 logit("Invalid command.");
 946                 goto out;
 947         }
 948
 949         if (delete && !compat20) {
 950                 logit("Not supported for SSH protocol version 1.");
 951                 goto out;
 952         }
 953
 954         while (isspace((u_char)*++s))
 955                 ;
 956
 957         /* XXX update list of forwards in options */
 958         if (delete) {
 959                 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */
 960                 if (!parse_forward(&fwd, s, 1, 0)) {
 961                         logit("Bad forwarding close specification.");
 962                         goto out;
 963                 }
 964                 if (remote)
 965                         ok = channel_request_rforward_cancel(&fwd) == 0;
 966                 else if (dynamic)
 967                         ok = channel_cancel_lport_listener(&fwd,
 968                             0, &options.fwd_opts) > 0;
 969                 else
 970                         ok = channel_cancel_lport_listener(&fwd,
 971                             CHANNEL_CANCEL_PORT_STATIC,
 972                             &options.fwd_opts) > 0;
 973                 if (!ok) {
 974                         logit("Unkown port forwarding.");
 975                         goto out;
 976                 }
 977                 logit("Canceled forwarding.");
 978         } else {
 979                 if (!parse_forward(&fwd, s, dynamic, remote)) {
 980                         logit("Bad forwarding specification.");
 981                         goto out;
 982                 }
 983                 if (local || dynamic) {
 984                         if (!channel_setup_local_fwd_listener(&fwd,
 985                             &options.fwd_opts)) {
 986                                 logit("Port forwarding failed.");
 987                                 goto out;
 988                         }
 989                 } else {
 990                         if (channel_request_remote_forwarding(&fwd) < 0) {
 991                                 logit("Port forwarding failed.");
 992                                 goto out;
 993                         }
 994                 }
 995                 logit("Forwarding port.");
 996         }
 997
 998 out:
 999         signal(SIGINT, handler);
1000         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1001         free(cmd);
1002         free(fwd.listen_host);
1003         free(fwd.listen_path);
1004         free(fwd.connect_host);
1005         free(fwd.connect_path);
1006 }
1007
1008 /* reasons to suppress output of an escape command in help output */
1009 #define SUPPRESS_NEVER          0       /* never suppress, always show */
1010 #define SUPPRESS_PROTO1         1       /* don't show in protocol 1 sessions */
1011 #define SUPPRESS_MUXCLIENT      2       /* don't show in mux client sessions */
1012 #define SUPPRESS_MUXMASTER      4       /* don't show in mux master sessions */
1013 #define SUPPRESS_SYSLOG         8       /* don't show when logging to syslog */
1014 struct escape_help_text {
1015         const char *cmd;
1016         const char *text;
1017         unsigned int flags;
1018 };
1019 static struct escape_help_text esc_txt[] = {
1020     {".",  "terminate session", SUPPRESS_MUXMASTER},
1021     {".",  "terminate connection (and any multiplexed sessions)",
1022         SUPPRESS_MUXCLIENT},
1023     {"B",  "send a BREAK to the remote system", SUPPRESS_PROTO1},
1024     {"C",  "open a command line", SUPPRESS_MUXCLIENT},
1025     {"R",  "request rekey", SUPPRESS_PROTO1},
1026     {"V/v",  "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT},
1027     {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT},
1028     {"#",  "list forwarded connections", SUPPRESS_NEVER},
1029     {"&",  "background ssh (when waiting for connections to terminate)",
1030         SUPPRESS_MUXCLIENT},
1031     {"?", "this message", SUPPRESS_NEVER},
1032 };
1033
1034 static void
1035 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client,
1036     int using_stderr)
1037 {
1038         unsigned int i, suppress_flags;
1039         char string[1024];
1040
1041         snprintf(string, sizeof string, "%c?\r\n"
1042             "Supported escape sequences:\r\n", escape_char);
1043         buffer_append(b, string, strlen(string));
1044
1045         suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) |
1046             (mux_client ? SUPPRESS_MUXCLIENT : 0) |
1047             (mux_client ? 0 : SUPPRESS_MUXMASTER) |
1048             (using_stderr ? 0 : SUPPRESS_SYSLOG);
1049
1050         for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) {
1051                 if (esc_txt[i].flags & suppress_flags)
1052                         continue;
1053                 snprintf(string, sizeof string, " %c%-3s - %s\r\n",
1054                     escape_char, esc_txt[i].cmd, esc_txt[i].text);
1055                 buffer_append(b, string, strlen(string));
1056         }
1057
1058         snprintf(string, sizeof string,
1059             " %c%c   - send the escape character by typing it twice\r\n"
1060             "(Note that escapes are only recognized immediately after "
1061             "newline.)\r\n", escape_char, escape_char);
1062         buffer_append(b, string, strlen(string));
1063 }
1064
1065 /*
1066  * Process the characters one by one, call with c==NULL for proto1 case.
1067  */
1068 static int
1069 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
1070     char *buf, int len)
1071 {
1072         char string[1024];
1073         pid_t pid;
1074         int bytes = 0;
1075         u_int i;
1076         u_char ch;
1077         char *s;
1078         int *escape_pendingp, escape_char;
1079         struct escape_filter_ctx *efc;
1080
1081         if (c == NULL) {
1082                 escape_pendingp = &escape_pending1;
1083                 escape_char = escape_char1;
1084         } else {
1085                 if (c->filter_ctx == NULL)
1086                         return 0;
1087                 efc = (struct escape_filter_ctx *)c->filter_ctx;
1088                 escape_pendingp = &efc->escape_pending;
1089                 escape_char = efc->escape_char;
1090         }
1091
1092         if (len <= 0)
1093                 return (0);
1094
1095         for (i = 0; i < (u_int)len; i++) {
1096                 /* Get one character at a time. */
1097                 ch = buf[i];
1098
1099                 if (*escape_pendingp) {
1100                         /* We have previously seen an escape character. */
1101                         /* Clear the flag now. */
1102                         *escape_pendingp = 0;
1103
1104                         /* Process the escaped character. */
1105                         switch (ch) {
1106                         case '.':
1107                                 /* Terminate the connection. */
1108                                 snprintf(string, sizeof string, "%c.\r\n",
1109                                     escape_char);
1110                                 buffer_append(berr, string, strlen(string));
1111
1112                                 if (c && c->ctl_chan != -1) {
1113                                         chan_read_failed(c);
1114                                         chan_write_failed(c);
1115                                         if (c->detach_user)
1116                                                 c->detach_user(c->self, NULL);
1117                                         c->type = SSH_CHANNEL_ABANDONED;
1118                                         buffer_clear(&c->input);
1119                                         chan_ibuf_empty(c);
1120                                         return 0;
1121                                 } else
1122                                         quit_pending = 1;
1123                                 return -1;
1124
1125                         case 'Z' - 64:
1126                                 /* XXX support this for mux clients */
1127                                 if (c && c->ctl_chan != -1) {
1128                                         char b[16];
1129  noescape:
1130                                         if (ch == 'Z' - 64)
1131                                                 snprintf(b, sizeof b, "^Z");
1132                                         else
1133                                                 snprintf(b, sizeof b, "%c", ch);
1134                                         snprintf(string, sizeof string,
1135                                             "%c%s escape not available to "
1136                                             "multiplexed sessions\r\n",
1137                                             escape_char, b);
1138                                         buffer_append(berr, string,
1139                                             strlen(string));
1140                                         continue;
1141                                 }
1142                                 /* Suspend the program. Inform the user */
1143                                 snprintf(string, sizeof string,
1144                                     "%c^Z [suspend ssh]\r\n", escape_char);
1145                                 buffer_append(berr, string, strlen(string));
1146
1147                                 /* Restore terminal modes and suspend. */
1148                                 client_suspend_self(bin, bout, berr);
1149
1150                                 /* We have been continued. */
1151                                 continue;
1152
1153                         case 'B':
1154                                 if (compat20) {
1155                                         snprintf(string, sizeof string,
1156                                             "%cB\r\n", escape_char);
1157                                         buffer_append(berr, string,
1158                                             strlen(string));
1159                                         channel_request_start(c->self,
1160                                             "break", 0);
1161                                         packet_put_int(1000);
1162                                         packet_send();
1163                                 }
1164                                 continue;
1165
1166                         case 'R':
1167                                 if (compat20) {
1168                                         if (datafellows & SSH_BUG_NOREKEY)
1169                                                 logit("Server does not "
1170                                                     "support re-keying");
1171                                         else
1172                                                 need_rekeying = 1;
1173                                 }
1174                                 continue;
1175
1176                         case 'V':
1177                                 /* FALLTHROUGH */
1178                         case 'v':
1179                                 if (c && c->ctl_chan != -1)
1180                                         goto noescape;
1181                                 if (!log_is_on_stderr()) {
1182                                         snprintf(string, sizeof string,
1183                                             "%c%c [Logging to syslog]\r\n",
1184                                              escape_char, ch);
1185                                         buffer_append(berr, string,
1186                                             strlen(string));
1187                                         continue;
1188                                 }
1189                                 if (ch == 'V' && options.log_level >
1190                                     SYSLOG_LEVEL_QUIET)
1191                                         log_change_level(--options.log_level);
1192                                 if (ch == 'v' && options.log_level <
1193                                     SYSLOG_LEVEL_DEBUG3)
1194                                         log_change_level(++options.log_level);
1195                                 snprintf(string, sizeof string,
1196                                     "%c%c [LogLevel %s]\r\n", escape_char, ch,
1197                                     log_level_name(options.log_level));
1198                                 buffer_append(berr, string, strlen(string));
1199                                 continue;
1200
1201                         case '&':
1202                                 if (c && c->ctl_chan != -1)
1203                                         goto noescape;
1204                                 /*
1205                                  * Detach the program (continue to serve
1206                                  * connections, but put in background and no
1207                                  * more new connections).
1208                                  */
1209                                 /* Restore tty modes. */
1210                                 leave_raw_mode(
1211                                     options.request_tty == REQUEST_TTY_FORCE);
1212
1213                                 /* Stop listening for new connections. */
1214                                 channel_stop_listening();
1215
1216                                 snprintf(string, sizeof string,
1217                                     "%c& [backgrounded]\n", escape_char);
1218                                 buffer_append(berr, string, strlen(string));
1219
1220                                 /* Fork into background. */
1221                                 pid = fork();
1222                                 if (pid < 0) {
1223                                         error("fork: %.100s", strerror(errno));
1224                                         continue;
1225                                 }
1226                                 if (pid != 0) { /* This is the parent. */
1227                                         /* The parent just exits. */
1228                                         exit(0);
1229                                 }
1230                                 /* The child continues serving connections. */
1231                                 if (compat20) {
1232                                         buffer_append(bin, "\004", 1);
1233                                         /* fake EOF on stdin */
1234                                         return -1;
1235                                 } else if (!stdin_eof) {
1236                                         /*
1237                                          * Sending SSH_CMSG_EOF alone does not
1238                                          * always appear to be enough.  So we
1239                                          * try to send an EOF character first.
1240                                          */
1241                                         packet_start(SSH_CMSG_STDIN_DATA);
1242                                         packet_put_string("\004", 1);
1243                                         packet_send();
1244                                         /* Close stdin. */
1245                                         stdin_eof = 1;
1246                                         if (buffer_len(bin) == 0) {
1247                                                 packet_start(SSH_CMSG_EOF);
1248                                                 packet_send();
1249                                         }
1250                                 }
1251                                 continue;
1252
1253                         case '?':
1254                                 print_escape_help(berr, escape_char, compat20,
1255                                     (c && c->ctl_chan != -1),
1256                                     log_is_on_stderr());
1257                                 continue;
1258
1259                         case '#':
1260                                 snprintf(string, sizeof string, "%c#\r\n",
1261                                     escape_char);
1262                                 buffer_append(berr, string, strlen(string));
1263                                 s = channel_open_message();
1264                                 buffer_append(berr, s, strlen(s));
1265                                 free(s);
1266                                 continue;
1267
1268                         case 'C':
1269                                 if (c && c->ctl_chan != -1)
1270                                         goto noescape;
1271                                 process_cmdline();
1272                                 continue;
1273
1274                         default:
1275                                 if (ch != escape_char) {
1276                                         buffer_put_char(bin, escape_char);
1277                                         bytes++;
1278                                 }
1279                                 /* Escaped characters fall through here */
1280                                 break;
1281                         }
1282                 } else {
1283                         /*
1284                          * The previous character was not an escape char.
1285                          * Check if this is an escape.
1286                          */
1287                         if (last_was_cr && ch == escape_char) {
1288                                 /*
1289                                  * It is. Set the flag and continue to
1290                                  * next character.
1291                                  */
1292                                 *escape_pendingp = 1;
1293                                 continue;
1294                         }
1295                 }
1296
1297                 /*
1298                  * Normal character.  Record whether it was a newline,
1299                  * and append it to the buffer.
1300                  */
1301                 last_was_cr = (ch == '\r' || ch == '\n');
1302                 buffer_put_char(bin, ch);
1303                 bytes++;
1304         }
1305         return bytes;
1306 }
1307
1308 static void
1309 client_process_input(fd_set *readset)
1310 {
1311         int len;
1312         char buf[SSH_IOBUFSZ];
1313
1314         /* Read input from stdin. */
1315         if (FD_ISSET(fileno(stdin), readset)) {
1316                 /* Read as much as possible. */
1317                 len = read(fileno(stdin), buf, sizeof(buf));
1318                 if (len < 0 &&
1319                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1320                         return;         /* we'll try again later */
1321                 if (len <= 0) {
1322                         /*
1323                          * Received EOF or error.  They are treated
1324                          * similarly, except that an error message is printed
1325                          * if it was an error condition.
1326                          */
1327                         if (len < 0) {
1328                                 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1329                                     strerror(errno));
1330                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1331                         }
1332                         /* Mark that we have seen EOF. */
1333                         stdin_eof = 1;
1334                         /*
1335                          * Send an EOF message to the server unless there is
1336                          * data in the buffer.  If there is data in the
1337                          * buffer, no message will be sent now.  Code
1338                          * elsewhere will send the EOF when the buffer
1339                          * becomes empty if stdin_eof is set.
1340                          */
1341                         if (buffer_len(&stdin_buffer) == 0) {
1342                                 packet_start(SSH_CMSG_EOF);
1343                                 packet_send();
1344                         }
1345                 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1346                         /*
1347                          * Normal successful read, and no escape character.
1348                          * Just append the data to buffer.
1349                          */
1350                         buffer_append(&stdin_buffer, buf, len);
1351                 } else {
1352                         /*
1353                          * Normal, successful read.  But we have an escape
1354                          * character and have to process the characters one
1355                          * by one.
1356                          */
1357                         if (process_escapes(NULL, &stdin_buffer,
1358                             &stdout_buffer, &stderr_buffer, buf, len) == -1)
1359                                 return;
1360                 }
1361         }
1362 }
1363
1364 static void
1365 client_process_output(fd_set *writeset)
1366 {
1367         int len;
1368         char buf[100];
1369
1370         /* Write buffered output to stdout. */
1371         if (FD_ISSET(fileno(stdout), writeset)) {
1372                 /* Write as much data as possible. */
1373                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1374                     buffer_len(&stdout_buffer));
1375                 if (len <= 0) {
1376                         if (errno == EINTR || errno == EAGAIN ||
1377                             errno == EWOULDBLOCK)
1378                                 len = 0;
1379                         else {
1380                                 /*
1381                                  * An error or EOF was encountered.  Put an
1382                                  * error message to stderr buffer.
1383                                  */
1384                                 snprintf(buf, sizeof buf,
1385                                     "write stdout: %.50s\r\n", strerror(errno));
1386                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1387                                 quit_pending = 1;
1388                                 return;
1389                         }
1390                 }
1391                 /* Consume printed data from the buffer. */
1392                 buffer_consume(&stdout_buffer, len);
1393         }
1394         /* Write buffered output to stderr. */
1395         if (FD_ISSET(fileno(stderr), writeset)) {
1396                 /* Write as much data as possible. */
1397                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1398                     buffer_len(&stderr_buffer));
1399                 if (len <= 0) {
1400                         if (errno == EINTR || errno == EAGAIN ||
1401                             errno == EWOULDBLOCK)
1402                                 len = 0;
1403                         else {
1404                                 /*
1405                                  * EOF or error, but can't even print
1406                                  * error message.
1407                                  */
1408                                 quit_pending = 1;
1409                                 return;
1410                         }
1411                 }
1412                 /* Consume printed characters from the buffer. */
1413                 buffer_consume(&stderr_buffer, len);
1414         }
1415 }
1416
1417 /*
1418  * Get packets from the connection input buffer, and process them as long as
1419  * there are packets available.
1420  *
1421  * Any unknown packets received during the actual
1422  * session cause the session to terminate.  This is
1423  * intended to make debugging easier since no
1424  * confirmations are sent.  Any compatible protocol
1425  * extensions must be negotiated during the
1426  * preparatory phase.
1427  */
1428
1429 static void
1430 client_process_buffered_input_packets(void)
1431 {
1432         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, active_state);
1433 }
1434
1435 /* scan buf[] for '~' before sending data to the peer */
1436
1437 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1438 void *
1439 client_new_escape_filter_ctx(int escape_char)
1440 {
1441         struct escape_filter_ctx *ret;
1442
1443         ret = xcalloc(1, sizeof(*ret));
1444         ret->escape_pending = 0;
1445         ret->escape_char = escape_char;
1446         return (void *)ret;
1447 }
1448
1449 /* Free the escape filter context on channel free */
1450 void
1451 client_filter_cleanup(int cid, void *ctx)
1452 {
1453         free(ctx);
1454 }
1455
1456 int
1457 client_simple_escape_filter(Channel *c, char *buf, int len)
1458 {
1459         if (c->extended_usage != CHAN_EXTENDED_WRITE)
1460                 return 0;
1461
1462         return process_escapes(c, &c->input, &c->output, &c->extended,
1463             buf, len);
1464 }
1465
1466 static void
1467 client_channel_closed(int id, void *arg)
1468 {
1469         channel_cancel_cleanup(id);
1470         session_closed = 1;
1471         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1472 }
1473
1474 /*
1475  * Implements the interactive session with the server.  This is called after
1476  * the user has been authenticated, and a command has been started on the
1477  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1478  * used as an escape character for terminating or suspending the session.
1479  */
1480
1481 int
1482 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1483 {
1484         fd_set *readset = NULL, *writeset = NULL;
1485         double start_time, total_time;
1486         int r, max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1487         u_int64_t ibytes, obytes;
1488         u_int nalloc = 0;
1489         char buf[100];
1490
1491         debug("Entering interactive session.");
1492
1493         start_time = get_current_time();
1494
1495         /* Initialize variables. */
1496         escape_pending1 = 0;
1497         last_was_cr = 1;
1498         exit_status = -1;
1499         stdin_eof = 0;
1500         buffer_high = 64 * 1024;
1501         connection_in = packet_get_connection_in();
1502         connection_out = packet_get_connection_out();
1503         max_fd = MAX(connection_in, connection_out);
1504
1505         if (!compat20) {
1506                 /* enable nonblocking unless tty */
1507                 if (!isatty(fileno(stdin)))
1508                         set_nonblock(fileno(stdin));
1509                 if (!isatty(fileno(stdout)))
1510                         set_nonblock(fileno(stdout));
1511                 if (!isatty(fileno(stderr)))
1512                         set_nonblock(fileno(stderr));
1513                 max_fd = MAX(max_fd, fileno(stdin));
1514                 max_fd = MAX(max_fd, fileno(stdout));
1515                 max_fd = MAX(max_fd, fileno(stderr));
1516         }
1517         quit_pending = 0;
1518         escape_char1 = escape_char_arg;
1519
1520         /* Initialize buffers. */
1521         buffer_init(&stdin_buffer);
1522         buffer_init(&stdout_buffer);
1523         buffer_init(&stderr_buffer);
1524
1525         client_init_dispatch();
1526
1527         /*
1528          * Set signal handlers, (e.g. to restore non-blocking mode)
1529          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1530          */
1531         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1532                 signal(SIGHUP, signal_handler);
1533         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1534                 signal(SIGINT, signal_handler);
1535         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1536                 signal(SIGQUIT, signal_handler);
1537         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1538                 signal(SIGTERM, signal_handler);
1539         signal(SIGWINCH, window_change_handler);
1540
1541         if (have_pty)
1542                 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1543
1544         if (compat20) {
1545                 session_ident = ssh2_chan_id;
1546                 if (session_ident != -1) {
1547                         if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1548                                 channel_register_filter(session_ident,
1549                                     client_simple_escape_filter, NULL,
1550                                     client_filter_cleanup,
1551                                     client_new_escape_filter_ctx(
1552                                     escape_char_arg));
1553                         }
1554                         channel_register_cleanup(session_ident,
1555                             client_channel_closed, 0);
1556                 }
1557         } else {
1558                 /* Check if we should immediately send eof on stdin. */
1559                 client_check_initial_eof_on_stdin();
1560         }
1561
1562         /* Main loop of the client for the interactive session mode. */
1563         while (!quit_pending) {
1564
1565                 /* Process buffered packets sent by the server. */
1566                 client_process_buffered_input_packets();
1567
1568                 if (compat20 && session_closed && !channel_still_open())
1569                         break;
1570
1571                 rekeying = (active_state->kex != NULL && !active_state->kex->done);
1572
1573                 if (rekeying) {
1574                         debug("rekeying in progress");
1575                 } else {
1576                         /*
1577                          * Make packets of buffered stdin data, and buffer
1578                          * them for sending to the server.
1579                          */
1580                         if (!compat20)
1581                                 client_make_packets_from_stdin_data();
1582
1583                         /*
1584                          * Make packets from buffered channel data, and
1585                          * enqueue them for sending to the server.
1586                          */
1587                         if (packet_not_very_much_data_to_write())
1588                                 channel_output_poll();
1589
1590                         /*
1591                          * Check if the window size has changed, and buffer a
1592                          * message about it to the server if so.
1593                          */
1594                         client_check_window_change();
1595
1596                         if (quit_pending)
1597                                 break;
1598                 }
1599                 /*
1600                  * Wait until we have something to do (something becomes
1601                  * available on one of the descriptors).
1602                  */
1603                 max_fd2 = max_fd;
1604                 client_wait_until_can_do_something(&readset, &writeset,
1605                     &max_fd2, &nalloc, rekeying);
1606
1607                 if (quit_pending)
1608                         break;
1609
1610                 /* Do channel operations unless rekeying in progress. */
1611                 if (!rekeying) {
1612                         channel_after_select(readset, writeset);
1613                         if (need_rekeying || packet_need_rekeying()) {
1614                                 debug("need rekeying");
1615                                 active_state->kex->done = 0;
1616                                 if ((r = kex_send_kexinit(active_state)) != 0)
1617                                         fatal("%s: kex_send_kexinit: %s",
1618                                             __func__, ssh_err(r));
1619                                 need_rekeying = 0;
1620                         }
1621                 }
1622
1623                 /* Buffer input from the connection.  */
1624                 client_process_net_input(readset);
1625
1626                 if (quit_pending)
1627                         break;
1628
1629                 if (!compat20) {
1630                         /* Buffer data from stdin */
1631                         client_process_input(readset);
1632                         /*
1633                          * Process output to stdout and stderr.  Output to
1634                          * the connection is processed elsewhere (above).
1635                          */
1636                         client_process_output(writeset);
1637                 }
1638
1639                 if (session_resumed) {
1640                         connection_in = packet_get_connection_in();
1641                         connection_out = packet_get_connection_out();
1642                         max_fd = MAX(max_fd, connection_out);
1643                         max_fd = MAX(max_fd, connection_in);
1644                         session_resumed = 0;
1645                 }
1646
1647                 /*
1648                  * Send as much buffered packet data as possible to the
1649                  * sender.
1650                  */
1651                 if (FD_ISSET(connection_out, writeset))
1652                         packet_write_poll();
1653
1654                 /*
1655                  * If we are a backgrounded control master, and the
1656                  * timeout has expired without any active client
1657                  * connections, then quit.
1658                  */
1659                 if (control_persist_exit_time > 0) {
1660                         if (monotime() >= control_persist_exit_time) {
1661                                 debug("ControlPersist timeout expired");
1662                                 break;
1663                         }
1664                 }
1665         }
1666         free(readset);
1667         free(writeset);
1668
1669         /* Terminate the session. */
1670
1671         /* Stop watching for window change. */
1672         signal(SIGWINCH, SIG_DFL);
1673
1674         if (compat20) {
1675                 packet_start(SSH2_MSG_DISCONNECT);
1676                 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1677                 packet_put_cstring("disconnected by user");
1678                 packet_put_cstring(""); /* language tag */
1679                 packet_send();
1680                 packet_write_wait();
1681         }
1682
1683         channel_free_all();
1684
1685         if (have_pty)
1686                 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1687
1688         /* restore blocking io */
1689         if (!isatty(fileno(stdin)))
1690                 unset_nonblock(fileno(stdin));
1691         if (!isatty(fileno(stdout)))
1692                 unset_nonblock(fileno(stdout));
1693         if (!isatty(fileno(stderr)))
1694                 unset_nonblock(fileno(stderr));
1695
1696         /*
1697          * If there was no shell or command requested, there will be no remote
1698          * exit status to be returned.  In that case, clear error code if the
1699          * connection was deliberately terminated at this end.
1700          */
1701         if (no_shell_flag && received_signal == SIGTERM) {
1702                 received_signal = 0;
1703                 exit_status = 0;
1704         }
1705
1706         if (received_signal)
1707                 fatal("Killed by signal %d.", (int) received_signal);
1708
1709         /*
1710          * In interactive mode (with pseudo tty) display a message indicating
1711          * that the connection has been closed.
1712          */
1713         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1714                 snprintf(buf, sizeof buf,
1715                     "Connection to %.64s closed.\r\n", host);
1716                 buffer_append(&stderr_buffer, buf, strlen(buf));
1717         }
1718
1719         /* Output any buffered data for stdout. */
1720         if (buffer_len(&stdout_buffer) > 0) {
1721                 len = atomicio(vwrite, fileno(stdout),
1722                     buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer));
1723                 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer))
1724                         error("Write failed flushing stdout buffer.");
1725                 else
1726                         buffer_consume(&stdout_buffer, len);
1727         }
1728
1729         /* Output any buffered data for stderr. */
1730         if (buffer_len(&stderr_buffer) > 0) {
1731                 len = atomicio(vwrite, fileno(stderr),
1732                     buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer));
1733                 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer))
1734                         error("Write failed flushing stderr buffer.");
1735                 else
1736                         buffer_consume(&stderr_buffer, len);
1737         }
1738
1739         /* Clear and free any buffers. */
1740         memset(buf, 0, sizeof(buf));
1741         buffer_free(&stdin_buffer);
1742         buffer_free(&stdout_buffer);
1743         buffer_free(&stderr_buffer);
1744
1745         /* Report bytes transferred, and transfer rates. */
1746         total_time = get_current_time() - start_time;
1747         packet_get_bytes(&ibytes, &obytes);
1748         verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1749             (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1750         if (total_time > 0)
1751                 verbose("Bytes per second: sent %.1f, received %.1f",
1752                     obytes / total_time, ibytes / total_time);
1753         /* Return the exit status of the program. */
1754         debug("Exit status %d", exit_status);
1755         return exit_status;
1756 }
1757
1758 /*********/
1759
1760 static int
1761 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1762 {
1763         u_int data_len;
1764         char *data = packet_get_string(&data_len);
1765         packet_check_eom();
1766         buffer_append(&stdout_buffer, data, data_len);
1767         explicit_bzero(data, data_len);
1768         free(data);
1769         return 0;
1770 }
1771 static int
1772 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1773 {
1774         u_int data_len;
1775         char *data = packet_get_string(&data_len);
1776         packet_check_eom();
1777         buffer_append(&stderr_buffer, data, data_len);
1778         explicit_bzero(data, data_len);
1779         free(data);
1780         return 0;
1781 }
1782 static int
1783 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1784 {
1785         exit_status = packet_get_int();
1786         packet_check_eom();
1787         /* Acknowledge the exit. */
1788         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1789         packet_send();
1790         /*
1791          * Must wait for packet to be sent since we are
1792          * exiting the loop.
1793          */
1794         packet_write_wait();
1795         /* Flag that we want to exit. */
1796         quit_pending = 1;
1797         return 0;
1798 }
1799
1800 static int
1801 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1802 {
1803         Channel *c = NULL;
1804         int r, remote_id, sock;
1805
1806         /* Read the remote channel number from the message. */
1807         remote_id = packet_get_int();
1808         packet_check_eom();
1809
1810         /*
1811          * Get a connection to the local authentication agent (this may again
1812          * get forwarded).
1813          */
1814         if ((r = ssh_get_authentication_socket(&sock)) != 0 &&
1815             r != SSH_ERR_AGENT_NOT_PRESENT)
1816                 debug("%s: ssh_get_authentication_socket: %s",
1817                     __func__, ssh_err(r));
1818
1819
1820         /*
1821          * If we could not connect the agent, send an error message back to
1822          * the server. This should never happen unless the agent dies,
1823          * because authentication forwarding is only enabled if we have an
1824          * agent.
1825          */
1826         if (sock >= 0) {
1827                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1828                     -1, 0, 0, 0, "authentication agent connection", 1);
1829                 c->remote_id = remote_id;
1830                 c->force_drain = 1;
1831         }
1832         if (c == NULL) {
1833                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1834                 packet_put_int(remote_id);
1835         } else {
1836                 /* Send a confirmation to the remote host. */
1837                 debug("Forwarding authentication connection.");
1838                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1839                 packet_put_int(remote_id);
1840                 packet_put_int(c->self);
1841         }
1842         packet_send();
1843         return 0;
1844 }
1845
1846 static Channel *
1847 client_request_forwarded_tcpip(const char *request_type, int rchan)
1848 {
1849         Channel *c = NULL;
1850         char *listen_address, *originator_address;
1851         u_short listen_port, originator_port;
1852
1853         /* Get rest of the packet */
1854         listen_address = packet_get_string(NULL);
1855         listen_port = packet_get_int();
1856         originator_address = packet_get_string(NULL);
1857         originator_port = packet_get_int();
1858         packet_check_eom();
1859
1860         debug("%s: listen %s port %d, originator %s port %d", __func__,
1861             listen_address, listen_port, originator_address, originator_port);
1862
1863         c = channel_connect_by_listen_address(listen_address, listen_port,
1864             "forwarded-tcpip", originator_address);
1865
1866         free(originator_address);
1867         free(listen_address);
1868         return c;
1869 }
1870
1871 static Channel *
1872 client_request_forwarded_streamlocal(const char *request_type, int rchan)
1873 {
1874         Channel *c = NULL;
1875         char *listen_path;
1876
1877         /* Get the remote path. */
1878         listen_path = packet_get_string(NULL);
1879         /* XXX: Skip reserved field for now. */
1880         if (packet_get_string_ptr(NULL) == NULL)
1881                 fatal("%s: packet_get_string_ptr failed", __func__);
1882         packet_check_eom();
1883
1884         debug("%s: %s", __func__, listen_path);
1885
1886         c = channel_connect_by_listen_path(listen_path,
1887             "forwarded-streamlocal@openssh.com", "forwarded-streamlocal");
1888         free(listen_path);
1889         return c;
1890 }
1891
1892 static Channel *
1893 client_request_x11(const char *request_type, int rchan)
1894 {
1895         Channel *c = NULL;
1896         char *originator;
1897         u_short originator_port;
1898         int sock;
1899
1900         if (!options.forward_x11) {
1901                 error("Warning: ssh server tried X11 forwarding.");
1902                 error("Warning: this is probably a break-in attempt by a "
1903                     "malicious server.");
1904                 return NULL;
1905         }
1906         if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
1907                 verbose("Rejected X11 connection after ForwardX11Timeout "
1908                     "expired");
1909                 return NULL;
1910         }
1911         originator = packet_get_string(NULL);
1912         if (datafellows & SSH_BUG_X11FWD) {
1913                 debug2("buggy server: x11 request w/o originator_port");
1914                 originator_port = 0;
1915         } else {
1916                 originator_port = packet_get_int();
1917         }
1918         packet_check_eom();
1919         /* XXX check permission */
1920         debug("client_request_x11: request from %s %d", originator,
1921             originator_port);
1922         free(originator);
1923         sock = x11_connect_display();
1924         if (sock < 0)
1925                 return NULL;
1926         c = channel_new("x11",
1927             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1928             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1929         c->force_drain = 1;
1930         return c;
1931 }
1932
1933 static Channel *
1934 client_request_agent(const char *request_type, int rchan)
1935 {
1936         Channel *c = NULL;
1937         int r, sock;
1938
1939         if (!options.forward_agent) {
1940                 error("Warning: ssh server tried agent forwarding.");
1941                 error("Warning: this is probably a break-in attempt by a "
1942                     "malicious server.");
1943                 return NULL;
1944         }
1945         if ((r = ssh_get_authentication_socket(&sock)) != 0) {
1946                 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1947                         debug("%s: ssh_get_authentication_socket: %s",
1948                             __func__, ssh_err(r));
1949                 return NULL;
1950         }
1951         c = channel_new("authentication agent connection",
1952             SSH_CHANNEL_OPEN, sock, sock, -1,
1953             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1954             "authentication agent connection", 1);
1955         c->force_drain = 1;
1956         return c;
1957 }
1958
1959 int
1960 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1961 {
1962         Channel *c;
1963         int fd;
1964
1965         if (tun_mode == SSH_TUNMODE_NO)
1966                 return 0;
1967
1968         if (!compat20) {
1969                 error("Tunnel forwarding is not supported for protocol 1");
1970                 return -1;
1971         }
1972
1973         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1974
1975         /* Open local tunnel device */
1976         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1977                 error("Tunnel device open failed.");
1978                 return -1;
1979         }
1980
1981         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1982             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1983         c->datagram = 1;
1984
1985 #if defined(SSH_TUN_FILTER)
1986         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1987                 channel_register_filter(c->self, sys_tun_infilter,
1988                     sys_tun_outfilter, NULL, NULL);
1989 #endif
1990
1991         packet_start(SSH2_MSG_CHANNEL_OPEN);
1992         packet_put_cstring("tun@openssh.com");
1993         packet_put_int(c->self);
1994         packet_put_int(c->local_window_max);
1995         packet_put_int(c->local_maxpacket);
1996         packet_put_int(tun_mode);
1997         packet_put_int(remote_tun);
1998         packet_send();
1999
2000         return 0;
2001 }
2002
2003 /* XXXX move to generic input handler */
2004 static int
2005 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
2006 {
2007         Channel *c = NULL;
2008         char *ctype;
2009         int rchan;
2010         u_int rmaxpack, rwindow, len;
2011
2012         ctype = packet_get_string(&len);
2013         rchan = packet_get_int();
2014         rwindow = packet_get_int();
2015         rmaxpack = packet_get_int();
2016
2017         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
2018             ctype, rchan, rwindow, rmaxpack);
2019
2020         if (strcmp(ctype, "forwarded-tcpip") == 0) {
2021                 c = client_request_forwarded_tcpip(ctype, rchan);
2022         } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) {
2023                 c = client_request_forwarded_streamlocal(ctype, rchan);
2024         } else if (strcmp(ctype, "x11") == 0) {
2025                 c = client_request_x11(ctype, rchan);
2026         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
2027                 c = client_request_agent(ctype, rchan);
2028         }
2029 /* XXX duplicate : */
2030         if (c != NULL) {
2031                 debug("confirm %s", ctype);
2032                 c->remote_id = rchan;
2033                 c->remote_window = rwindow;
2034                 c->remote_maxpacket = rmaxpack;
2035                 if (c->type != SSH_CHANNEL_CONNECTING) {
2036                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2037                         packet_put_int(c->remote_id);
2038                         packet_put_int(c->self);
2039                         packet_put_int(c->local_window);
2040                         packet_put_int(c->local_maxpacket);
2041                         packet_send();
2042                 }
2043         } else {
2044                 debug("failure %s", ctype);
2045                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2046                 packet_put_int(rchan);
2047                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
2048                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2049                         packet_put_cstring("open failed");
2050                         packet_put_cstring("");
2051                 }
2052                 packet_send();
2053         }
2054         free(ctype);
2055         return 0;
2056 }
2057
2058 static int
2059 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
2060 {
2061         Channel *c = NULL;
2062         int exitval, id, reply, success = 0;
2063         char *rtype;
2064
2065         id = packet_get_int();
2066         rtype = packet_get_string(NULL);
2067         reply = packet_get_char();
2068
2069         debug("client_input_channel_req: channel %d rtype %s reply %d",
2070             id, rtype, reply);
2071
2072         if (id == -1) {
2073                 error("client_input_channel_req: request for channel -1");
2074         } else if ((c = channel_lookup(id)) == NULL) {
2075                 error("client_input_channel_req: channel %d: "
2076                     "unknown channel", id);
2077         } else if (strcmp(rtype, "eow@openssh.com") == 0) {
2078                 packet_check_eom();
2079                 chan_rcvd_eow(c);
2080         } else if (strcmp(rtype, "exit-status") == 0) {
2081                 exitval = packet_get_int();
2082                 if (c->ctl_chan != -1) {
2083                         mux_exit_message(c, exitval);
2084                         success = 1;
2085                 } else if (id == session_ident) {
2086                         /* Record exit value of local session */
2087                         success = 1;
2088                         exit_status = exitval;
2089                 } else {
2090                         /* Probably for a mux channel that has already closed */
2091                         debug("%s: no sink for exit-status on channel %d",
2092                             __func__, id);
2093                 }
2094                 packet_check_eom();
2095         }
2096         if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) {
2097                 packet_start(success ?
2098                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
2099                 packet_put_int(c->remote_id);
2100                 packet_send();
2101         }
2102         free(rtype);
2103         return 0;
2104 }
2105
2106 struct hostkeys_update_ctx {
2107         /* The hostname and (optionally) IP address string for the server */
2108         char *host_str, *ip_str;
2109
2110         /*
2111          * Keys received from the server and a flag for each indicating
2112          * whether they already exist in known_hosts.
2113          * keys_seen is filled in by hostkeys_find() and later (for new
2114          * keys) by client_global_hostkeys_private_confirm().
2115          */
2116         struct sshkey **keys;
2117         int *keys_seen;
2118         size_t nkeys;
2119
2120         size_t nnew;
2121
2122         /*
2123          * Keys that are in known_hosts, but were not present in the update
2124          * from the server (i.e. scheduled to be deleted).
2125          * Filled in by hostkeys_find().
2126          */
2127         struct sshkey **old_keys;
2128         size_t nold;
2129 };
2130
2131 static void
2132 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx)
2133 {
2134         size_t i;
2135
2136         if (ctx == NULL)
2137                 return;
2138         for (i = 0; i < ctx->nkeys; i++)
2139                 sshkey_free(ctx->keys[i]);
2140         free(ctx->keys);
2141         free(ctx->keys_seen);
2142         for (i = 0; i < ctx->nold; i++)
2143                 sshkey_free(ctx->old_keys[i]);
2144         free(ctx->old_keys);
2145         free(ctx->host_str);
2146         free(ctx->ip_str);
2147         free(ctx);
2148 }
2149
2150 static int
2151 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
2152 {
2153         struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
2154         size_t i;
2155         struct sshkey **tmp;
2156
2157         if (l->status != HKF_STATUS_MATCHED || l->key == NULL ||
2158             l->key->type == KEY_RSA1)
2159                 return 0;
2160
2161         /* Mark off keys we've already seen for this host */
2162         for (i = 0; i < ctx->nkeys; i++) {
2163                 if (sshkey_equal(l->key, ctx->keys[i])) {
2164                         debug3("%s: found %s key at %s:%ld", __func__,
2165                             sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum);
2166                         ctx->keys_seen[i] = 1;
2167                         return 0;
2168                 }
2169         }
2170         /* This line contained a key that not offered by the server */
2171         debug3("%s: deprecated %s key at %s:%ld", __func__,
2172             sshkey_ssh_name(l->key), l->path, l->linenum);
2173         if ((tmp = reallocarray(ctx->old_keys, ctx->nold + 1,
2174             sizeof(*ctx->old_keys))) == NULL)
2175                 fatal("%s: reallocarray failed nold = %zu",
2176                     __func__, ctx->nold);
2177         ctx->old_keys = tmp;
2178         ctx->old_keys[ctx->nold++] = l->key;
2179         l->key = NULL;
2180
2181         return 0;
2182 }
2183
2184 static void
2185 update_known_hosts(struct hostkeys_update_ctx *ctx)
2186 {
2187         int r, was_raw = 0;
2188         int loglevel = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK ?
2189             SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE;
2190         char *fp, *response;
2191         size_t i;
2192
2193         for (i = 0; i < ctx->nkeys; i++) {
2194                 if (ctx->keys_seen[i] != 2)
2195                         continue;
2196                 if ((fp = sshkey_fingerprint(ctx->keys[i],
2197                     options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2198                         fatal("%s: sshkey_fingerprint failed", __func__);
2199                 do_log2(loglevel, "Learned new hostkey: %s %s",
2200                     sshkey_type(ctx->keys[i]), fp);
2201                 free(fp);
2202         }
2203         for (i = 0; i < ctx->nold; i++) {
2204                 if ((fp = sshkey_fingerprint(ctx->old_keys[i],
2205                     options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2206                         fatal("%s: sshkey_fingerprint failed", __func__);
2207                 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s",
2208                     sshkey_type(ctx->old_keys[i]), fp);
2209                 free(fp);
2210         }
2211         if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
2212                 if (get_saved_tio() != NULL) {
2213                         leave_raw_mode(1);
2214                         was_raw = 1;
2215                 }
2216                 response = NULL;
2217                 for (i = 0; !quit_pending && i < 3; i++) {
2218                         free(response);
2219                         response = read_passphrase("Accept updated hostkeys? "
2220                             "(yes/no): ", RP_ECHO);
2221                         if (strcasecmp(response, "yes") == 0)
2222                                 break;
2223                         else if (quit_pending || response == NULL ||
2224                             strcasecmp(response, "no") == 0) {
2225                                 options.update_hostkeys = 0;
2226                                 break;
2227                         } else {
2228                                 do_log2(loglevel, "Please enter "
2229                                     "\"yes\" or \"no\"");
2230                         }
2231                 }
2232                 if (quit_pending || i >= 3 || response == NULL)
2233                         options.update_hostkeys = 0;
2234                 free(response);
2235                 if (was_raw)
2236                         enter_raw_mode(1);
2237         }
2238
2239         /*
2240          * Now that all the keys are verified, we can go ahead and replace
2241          * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't
2242          * cancel the operation).
2243          */
2244         if (options.update_hostkeys != 0 &&
2245             (r = hostfile_replace_entries(options.user_hostfiles[0],
2246             ctx->host_str, ctx->ip_str, ctx->keys, ctx->nkeys,
2247             options.hash_known_hosts, 0,
2248             options.fingerprint_hash)) != 0)
2249                 error("%s: hostfile_replace_entries failed: %s",
2250                     __func__, ssh_err(r));
2251 }
2252
2253 static void
2254 client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx)
2255 {
2256         struct ssh *ssh = active_state; /* XXX */
2257         struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
2258         size_t i, ndone;
2259         struct sshbuf *signdata;
2260         int r;
2261         const u_char *sig;
2262         size_t siglen;
2263
2264         if (ctx->nnew == 0)
2265                 fatal("%s: ctx->nnew == 0", __func__); /* sanity */
2266         if (type != SSH2_MSG_REQUEST_SUCCESS) {
2267                 error("Server failed to confirm ownership of "
2268                     "private host keys");
2269                 hostkeys_update_ctx_free(ctx);
2270                 return;
2271         }
2272         if ((signdata = sshbuf_new()) == NULL)
2273                 fatal("%s: sshbuf_new failed", __func__);
2274         /* Don't want to accidentally accept an unbound signature */
2275         if (ssh->kex->session_id_len == 0)
2276                 fatal("%s: ssh->kex->session_id_len == 0", __func__);
2277         /*
2278          * Expect a signature for each of the ctx->nnew private keys we
2279          * haven't seen before. They will be in the same order as the
2280          * ctx->keys where the corresponding ctx->keys_seen[i] == 0.
2281          */
2282         for (ndone = i = 0; i < ctx->nkeys; i++) {
2283                 if (ctx->keys_seen[i])
2284                         continue;
2285                 /* Prepare data to be signed: session ID, unique string, key */
2286                 sshbuf_reset(signdata);
2287                 if ( (r = sshbuf_put_cstring(signdata,
2288                     "hostkeys-prove-00@openssh.com")) != 0 ||
2289                     (r = sshbuf_put_string(signdata, ssh->kex->session_id,
2290                     ssh->kex->session_id_len)) != 0 ||
2291                     (r = sshkey_puts(ctx->keys[i], signdata)) != 0)
2292                         fatal("%s: failed to prepare signature: %s",
2293                             __func__, ssh_err(r));
2294                 /* Extract and verify signature */
2295                 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) {
2296                         error("%s: couldn't parse message: %s",
2297                             __func__, ssh_err(r));
2298                         goto out;
2299                 }
2300                 if ((r = sshkey_verify(ctx->keys[i], sig, siglen,
2301                     sshbuf_ptr(signdata), sshbuf_len(signdata), 0)) != 0) {
2302                         error("%s: server gave bad signature for %s key %zu",
2303                             __func__, sshkey_type(ctx->keys[i]), i);
2304                         goto out;
2305                 }
2306                 /* Key is good. Mark it as 'seen' */
2307                 ctx->keys_seen[i] = 2;
2308                 ndone++;
2309         }
2310         if (ndone != ctx->nnew)
2311                 fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__,
2312                     ndone, ctx->nnew);  /* Shouldn't happen */
2313         ssh_packet_check_eom(ssh);
2314
2315         /* Make the edits to known_hosts */
2316         update_known_hosts(ctx);
2317  out:
2318         hostkeys_update_ctx_free(ctx);
2319 }
2320
2321 /*
2322  * Handle hostkeys-00@openssh.com global request to inform the client of all
2323  * the server's hostkeys. The keys are checked against the user's
2324  * HostkeyAlgorithms preference before they are accepted.
2325  */
2326 static int
2327 client_input_hostkeys(void)
2328 {
2329         struct ssh *ssh = active_state; /* XXX */
2330         const u_char *blob = NULL;
2331         size_t i, len = 0;
2332         struct sshbuf *buf = NULL;
2333         struct sshkey *key = NULL, **tmp;
2334         int r;
2335         char *fp;
2336         static int hostkeys_seen = 0; /* XXX use struct ssh */
2337         extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */
2338         struct hostkeys_update_ctx *ctx = NULL;
2339
2340         if (hostkeys_seen)
2341                 fatal("%s: server already sent hostkeys", __func__);
2342         if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK &&
2343             options.batch_mode)
2344                 return 1; /* won't ask in batchmode, so don't even try */
2345         if (!options.update_hostkeys || options.num_user_hostfiles <= 0)
2346                 return 1;
2347
2348         ctx = xcalloc(1, sizeof(*ctx));
2349         while (ssh_packet_remaining(ssh) > 0) {
2350                 sshkey_free(key);
2351                 key = NULL;
2352                 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) {
2353                         error("%s: couldn't parse message: %s",
2354                             __func__, ssh_err(r));
2355                         goto out;
2356                 }
2357                 if ((r = sshkey_from_blob(blob, len, &key)) != 0) {
2358                         error("%s: parse key: %s", __func__, ssh_err(r));
2359                         goto out;
2360                 }
2361                 fp = sshkey_fingerprint(key, options.fingerprint_hash,
2362                     SSH_FP_DEFAULT);
2363                 debug3("%s: received %s key %s", __func__,
2364                     sshkey_type(key), fp);
2365                 free(fp);
2366
2367                 /* Check that the key is accepted in HostkeyAlgorithms */
2368                 if (match_pattern_list(sshkey_ssh_name(key),
2369                     options.hostkeyalgorithms ? options.hostkeyalgorithms :
2370                     KEX_DEFAULT_PK_ALG, 0) != 1) {
2371                         debug3("%s: %s key not permitted by HostkeyAlgorithms",
2372                             __func__, sshkey_ssh_name(key));
2373                         continue;
2374                 }
2375                 /* Skip certs */
2376                 if (sshkey_is_cert(key)) {
2377                         debug3("%s: %s key is a certificate; skipping",
2378                             __func__, sshkey_ssh_name(key));
2379                         continue;
2380                 }
2381                 /* Ensure keys are unique */
2382                 for (i = 0; i < ctx->nkeys; i++) {
2383                         if (sshkey_equal(key, ctx->keys[i])) {
2384                                 error("%s: received duplicated %s host key",
2385                                     __func__, sshkey_ssh_name(key));
2386                                 goto out;
2387                         }
2388                 }
2389                 /* Key is good, record it */
2390                 if ((tmp = reallocarray(ctx->keys, ctx->nkeys + 1,
2391                     sizeof(*ctx->keys))) == NULL)
2392                         fatal("%s: reallocarray failed nkeys = %zu",
2393                             __func__, ctx->nkeys);
2394                 ctx->keys = tmp;
2395                 ctx->keys[ctx->nkeys++] = key;
2396                 key = NULL;
2397         }
2398
2399         if (ctx->nkeys == 0) {
2400                 debug("%s: server sent no hostkeys", __func__);
2401                 goto out;
2402         }
2403
2404         if ((ctx->keys_seen = calloc(ctx->nkeys,
2405             sizeof(*ctx->keys_seen))) == NULL)
2406                 fatal("%s: calloc failed", __func__);
2407
2408         get_hostfile_hostname_ipaddr(host,
2409             options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL,
2410             options.port, &ctx->host_str,
2411             options.check_host_ip ? &ctx->ip_str : NULL);
2412
2413         /* Find which keys we already know about. */
2414         if ((r = hostkeys_foreach(options.user_hostfiles[0], hostkeys_find,
2415             ctx, ctx->host_str, ctx->ip_str,
2416             HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) {
2417                 error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
2418                 goto out;
2419         }
2420
2421         /* Figure out if we have any new keys to add */
2422         ctx->nnew = 0;
2423         for (i = 0; i < ctx->nkeys; i++) {
2424                 if (!ctx->keys_seen[i])
2425                         ctx->nnew++;
2426         }
2427
2428         debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove",
2429             __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold);
2430
2431         if (ctx->nnew == 0 && ctx->nold != 0) {
2432                 /* We have some keys to remove. Just do it. */
2433                 update_known_hosts(ctx);
2434         } else if (ctx->nnew != 0) {
2435                 /*
2436                  * We have received hitherto-unseen keys from the server.
2437                  * Ask the server to confirm ownership of the private halves.
2438                  */
2439                 debug3("%s: asking server to prove ownership for %zu keys",
2440                     __func__, ctx->nnew);
2441                 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2442                     (r = sshpkt_put_cstring(ssh,
2443                     "hostkeys-prove-00@openssh.com")) != 0 ||
2444                     (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */
2445                         fatal("%s: cannot prepare packet: %s",
2446                             __func__, ssh_err(r));
2447                 if ((buf = sshbuf_new()) == NULL)
2448                         fatal("%s: sshbuf_new", __func__);
2449                 for (i = 0; i < ctx->nkeys; i++) {
2450                         if (ctx->keys_seen[i])
2451                                 continue;
2452                         sshbuf_reset(buf);
2453                         if ((r = sshkey_putb(ctx->keys[i], buf)) != 0)
2454                                 fatal("%s: sshkey_putb: %s",
2455                                     __func__, ssh_err(r));
2456                         if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
2457                                 fatal("%s: sshpkt_put_string: %s",
2458                                     __func__, ssh_err(r));
2459                 }
2460                 if ((r = sshpkt_send(ssh)) != 0)
2461                         fatal("%s: sshpkt_send: %s", __func__, ssh_err(r));
2462                 client_register_global_confirm(
2463                     client_global_hostkeys_private_confirm, ctx);
2464                 ctx = NULL;  /* will be freed in callback */
2465         }
2466
2467         /* Success */
2468  out:
2469         hostkeys_update_ctx_free(ctx);
2470         sshkey_free(key);
2471         sshbuf_free(buf);
2472         /*
2473          * NB. Return success for all cases. The server doesn't need to know
2474          * what the client does with its hosts file.
2475          */
2476         return 1;
2477 }
2478
2479 static int
2480 client_input_global_request(int type, u_int32_t seq, void *ctxt)
2481 {
2482         char *rtype;
2483         int want_reply;
2484         int success = 0;
2485
2486         rtype = packet_get_cstring(NULL);
2487         want_reply = packet_get_char();
2488         debug("client_input_global_request: rtype %s want_reply %d",
2489             rtype, want_reply);
2490         if (strcmp(rtype, "hostkeys-00@openssh.com") == 0)
2491                 success = client_input_hostkeys();
2492         if (want_reply) {
2493                 packet_start(success ?
2494                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
2495                 packet_send();
2496                 packet_write_wait();
2497         }
2498         free(rtype);
2499         return 0;
2500 }
2501
2502 void
2503 client_session2_setup(int id, int want_tty, int want_subsystem,
2504     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
2505 {
2506         int len;
2507         Channel *c = NULL;
2508
2509         debug2("%s: id %d", __func__, id);
2510
2511         if ((c = channel_lookup(id)) == NULL)
2512                 fatal("client_session2_setup: channel %d: unknown channel", id);
2513
2514         packet_set_interactive(want_tty,
2515             options.ip_qos_interactive, options.ip_qos_bulk);
2516
2517         if (want_tty) {
2518                 struct winsize ws;
2519
2520                 /* Store window size in the packet. */
2521                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
2522                         memset(&ws, 0, sizeof(ws));
2523
2524                 channel_request_start(id, "pty-req", 1);
2525                 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY);
2526                 packet_put_cstring(term != NULL ? term : "");
2527                 packet_put_int((u_int)ws.ws_col);
2528                 packet_put_int((u_int)ws.ws_row);
2529                 packet_put_int((u_int)ws.ws_xpixel);
2530                 packet_put_int((u_int)ws.ws_ypixel);
2531                 if (tiop == NULL)
2532                         tiop = get_saved_tio();
2533                 tty_make_modes(-1, tiop);
2534                 packet_send();
2535                 /* XXX wait for reply */
2536                 c->client_tty = 1;
2537         }
2538
2539         /* Transfer any environment variables from client to server */
2540         if (options.num_send_env != 0 && env != NULL) {
2541                 int i, j, matched;
2542                 char *name, *val;
2543
2544                 debug("Sending environment.");
2545                 for (i = 0; env[i] != NULL; i++) {
2546                         /* Split */
2547                         name = xstrdup(env[i]);
2548                         if ((val = strchr(name, '=')) == NULL) {
2549                                 free(name);
2550                                 continue;
2551                         }
2552                         *val++ = '\0';
2553
2554                         matched = 0;
2555                         for (j = 0; j < options.num_send_env; j++) {
2556                                 if (match_pattern(name, options.send_env[j])) {
2557                                         matched = 1;
2558                                         break;
2559                                 }
2560                         }
2561                         if (!matched) {
2562                                 debug3("Ignored env %s", name);
2563                                 free(name);
2564                                 continue;
2565                         }
2566
2567                         debug("Sending env %s = %s", name, val);
2568                         channel_request_start(id, "env", 0);
2569                         packet_put_cstring(name);
2570                         packet_put_cstring(val);
2571                         packet_send();
2572                         free(name);
2573                 }
2574         }
2575
2576         len = buffer_len(cmd);
2577         if (len > 0) {
2578                 if (len > 900)
2579                         len = 900;
2580                 if (want_subsystem) {
2581                         debug("Sending subsystem: %.*s",
2582                             len, (u_char*)buffer_ptr(cmd));
2583                         channel_request_start(id, "subsystem", 1);
2584                         client_expect_confirm(id, "subsystem", CONFIRM_CLOSE);
2585                 } else {
2586                         debug("Sending command: %.*s",
2587                             len, (u_char*)buffer_ptr(cmd));
2588                         channel_request_start(id, "exec", 1);
2589                         client_expect_confirm(id, "exec", CONFIRM_CLOSE);
2590                 }
2591                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2592                 packet_send();
2593         } else {
2594                 channel_request_start(id, "shell", 1);
2595                 client_expect_confirm(id, "shell", CONFIRM_CLOSE);
2596                 packet_send();
2597         }
2598 }
2599
2600 static void
2601 client_init_dispatch_20(void)
2602 {
2603         dispatch_init(&dispatch_protocol_error);
2604
2605         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2606         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2607         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2608         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2609         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2610         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2611         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2612         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2613         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2614         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2615         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2616         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2617
2618         /* rekeying */
2619         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2620
2621         /* global request reply messages */
2622         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2623         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2624 }
2625
2626 static void
2627 client_init_dispatch_13(void)
2628 {
2629         dispatch_init(NULL);
2630         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2631         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2632         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2633         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2634         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2635         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2636         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2637         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2638         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2639
2640         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2641             &client_input_agent_open : &deny_input_open);
2642         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2643             &x11_input_open : &deny_input_open);
2644 }
2645
2646 static void
2647 client_init_dispatch_15(void)
2648 {
2649         client_init_dispatch_13();
2650         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2651         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2652 }
2653
2654 static void
2655 client_init_dispatch(void)
2656 {
2657         if (compat20)
2658                 client_init_dispatch_20();
2659         else if (compat13)
2660                 client_init_dispatch_13();
2661         else
2662                 client_init_dispatch_15();
2663 }
2664
2665 void
2666 client_stop_mux(void)
2667 {
2668         if (options.control_path != NULL && muxserver_sock != -1)
2669                 unlink(options.control_path);
2670         /*
2671          * If we are in persist mode, or don't have a shell, signal that we
2672          * should close when all active channels are closed.
2673          */
2674         if (options.control_persist || no_shell_flag) {
2675                 session_closed = 1;
2676                 setproctitle("[stopped mux]");
2677         }
2678 }
2679
2680 /* client specific fatal cleanup */
2681 void
2682 cleanup_exit(int i)
2683 {
2684         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2685         leave_non_blocking();
2686         if (options.control_path != NULL && muxserver_sock != -1)
2687                 unlink(options.control_path);
2688         ssh_kill_proxy_command();
2689         _exit(i);
2690 }