crypto/openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.284 2016/02/08 10:57:07 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * The main loop for the interactive session (client side).
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  *
  15  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  *
  38  * SSH2 support added by Markus Friedl.
  39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #include "includes.h"
  63
  64 #include <sys/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 "ssherr.h"
 115 #include "hostfile.h"
 116
 117 /* import options */
 118 extern Options options;
 119
 120 /* Flag indicating that stdin should be redirected from /dev/null. */
 121 extern int stdin_null_flag;
 122
 123 /* Flag indicating that no shell has been requested */
 124 extern int no_shell_flag;
 125
 126 /* Control socket */
 127 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
 128
 129 /*
 130  * Name of the host we are connecting to.  This is the name given on the
 131  * command line, or the HostName specified for the user-supplied name in a
 132  * configuration file.
 133  */
 134 extern char *host;
 135
 136 /*
 137  * Flag to indicate that we have received a window change signal which has
 138  * not yet been processed.  This will cause a message indicating the new
 139  * window size to be sent to the server a little later.  This is volatile
 140  * because this is updated in a signal handler.
 141  */
 142 static volatile sig_atomic_t received_window_change_signal = 0;
 143 static volatile sig_atomic_t received_signal = 0;
 144
 145 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 146 static int in_non_blocking_mode = 0;
 147
 148 /* Time when backgrounded control master using ControlPersist should exit */
 149 static time_t control_persist_exit_time = 0;
 150
 151 /* Common data for the client loop code. */
 152 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 153 static int escape_char1;        /* Escape character. (proto1 only) */
 154 static int escape_pending1;     /* Last character was an escape (proto1 only) */
 155 static int last_was_cr;         /* Last character was a newline. */
 156 static int exit_status;         /* Used to store the command exit status. */
 157 static int stdin_eof;           /* EOF has been encountered on stderr. */
 158 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 159 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 160 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 161 static u_int buffer_high;       /* Soft max buffer size. */
 162 static int connection_in;       /* Connection to server (input). */
 163 static int connection_out;      /* Connection to server (output). */
 164 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 165 static int session_closed;      /* In SSH2: login session closed. */
 166 static u_int x11_refuse_time;   /* If >0, refuse x11 opens after this time. */
 167
 168 static void client_init_dispatch(void);
 169 int     session_ident = -1;
 170
 171 /* Track escape per proto2 channel */
 172 struct escape_filter_ctx {
 173         int escape_pending;
 174         int escape_char;
 175 };
 176
 177 /* Context for channel confirmation replies */
 178 struct channel_reply_ctx {
 179         const char *request_type;
 180         int id;
 181         enum confirm_action action;
 182 };
 183
 184 /* Global request success/failure callbacks */
 185 struct global_confirm {
 186         TAILQ_ENTRY(global_confirm) entry;
 187         global_confirm_cb *cb;
 188         void *ctx;
 189         int ref_count;
 190 };
 191 TAILQ_HEAD(global_confirms, global_confirm);
 192 static struct global_confirms global_confirms =
 193     TAILQ_HEAD_INITIALIZER(global_confirms);
 194
 195 void ssh_process_session2_setup(int, int, int, Buffer *);
 196
 197 /* Restores stdin to blocking mode. */
 198
 199 static void
 200 leave_non_blocking(void)
 201 {
 202         if (in_non_blocking_mode) {
 203                 unset_nonblock(fileno(stdin));
 204                 in_non_blocking_mode = 0;
 205         }
 206 }
 207
 208 /* Puts stdin terminal in non-blocking mode. */
 209
 210 static void
 211 enter_non_blocking(void)
 212 {
 213         in_non_blocking_mode = 1;
 214         set_nonblock(fileno(stdin));
 215 }
 216
 217 /*
 218  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 219  * flag indicating that the window has changed.
 220  */
 221 /*ARGSUSED */
 222 static void
 223 window_change_handler(int sig)
 224 {
 225         received_window_change_signal = 1;
 226         signal(SIGWINCH, window_change_handler);
 227 }
 228
 229 /*
 230  * Signal handler for signals that cause the program to terminate.  These
 231  * signals must be trapped to restore terminal modes.
 232  */
 233 /*ARGSUSED */
 234 static void
 235 signal_handler(int sig)
 236 {
 237         received_signal = sig;
 238         quit_pending = 1;
 239 }
 240
 241 /*
 242  * Returns current time in seconds from Jan 1, 1970 with the maximum
 243  * available resolution.
 244  */
 245
 246 static double
 247 get_current_time(void)
 248 {
 249         struct timeval tv;
 250         gettimeofday(&tv, NULL);
 251         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 252 }
 253
 254 /*
 255  * Sets control_persist_exit_time to the absolute time when the
 256  * backgrounded control master should exit due to expiry of the
 257  * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
 258  * control master process, or if there is no ControlPersist timeout.
 259  */
 260 static void
 261 set_control_persist_exit_time(void)
 262 {
 263         if (muxserver_sock == -1 || !options.control_persist
 264             || options.control_persist_timeout == 0) {
 265                 /* not using a ControlPersist timeout */
 266                 control_persist_exit_time = 0;
 267         } else if (channel_still_open()) {
 268                 /* some client connections are still open */
 269                 if (control_persist_exit_time > 0)
 270                         debug2("%s: cancel scheduled exit", __func__);
 271                 control_persist_exit_time = 0;
 272         } else if (control_persist_exit_time <= 0) {
 273                 /* a client connection has recently closed */
 274                 control_persist_exit_time = monotime() +
 275                         (time_t)options.control_persist_timeout;
 276                 debug2("%s: schedule exit in %d seconds", __func__,
 277                     options.control_persist_timeout);
 278         }
 279         /* else we are already counting down to the timeout */
 280 }
 281
 282 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_"
 283 static int
 284 client_x11_display_valid(const char *display)
 285 {
 286         size_t i, dlen;
 287
 288         if (display == NULL)
 289                 return 0;
 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 int
 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], line[512], xdisplay[512];
 309         char xauthfile[PATH_MAX], xauthdir[PATH_MAX];
 310         static char proto[512], data[512];
 311         FILE *f;
 312         int got_data = 0, generated = 0, do_unlink = 0, i, r;
 313         struct stat st;
 314         u_int now, x11_timeout_real;
 315
 316         *_proto = proto;
 317         *_data = data;
 318         proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0';
 319
 320         if (!client_x11_display_valid(display)) {
 321                 if (display != NULL)
 322                         logit("DISPLAY \"%s\" invalid; disabling X11 forwarding",
 323                             display);
 324                 return -1;
 325         }
 326         if (xauth_path != NULL && stat(xauth_path, &st) == -1) {
 327                 debug("No xauth program.");
 328                 xauth_path = NULL;
 329         }
 330
 331         if (xauth_path != NULL) {
 332                 /*
 333                  * Handle FamilyLocal case where $DISPLAY does
 334                  * not match an authorization entry.  For this we
 335                  * just try "xauth list unix:displaynum.screennum".
 336                  * XXX: "localhost" match to determine FamilyLocal
 337                  *      is not perfect.
 338                  */
 339                 if (strncmp(display, "localhost:", 10) == 0) {
 340                         if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 341                             display + 10)) < 0 ||
 342                             (size_t)r >= sizeof(xdisplay)) {
 343                                 error("%s: display name too long", __func__);
 344                                 return -1;
 345                         }
 346                         display = xdisplay;
 347                 }
 348                 if (trusted == 0) {
 349                         /*
 350                          * Generate an untrusted X11 auth cookie.
 351                          *
 352                          * The authentication cookie should briefly outlive
 353                          * ssh's willingness to forward X11 connections to
 354                          * avoid nasty fail-open behaviour in the X server.
 355                          */
 356                         mktemp_proto(xauthdir, sizeof(xauthdir));
 357                         if (mkdtemp(xauthdir) == NULL) {
 358                                 error("%s: mkdtemp: %s",
 359                                     __func__, strerror(errno));
 360                                 return -1;
 361                         }
 362                         do_unlink = 1;
 363                         if ((r = snprintf(xauthfile, sizeof(xauthfile),
 364                             "%s/xauthfile", xauthdir)) < 0 ||
 365                             (size_t)r >= sizeof(xauthfile)) {
 366                                 error("%s: xauthfile path too long", __func__);
 367                                 unlink(xauthfile);
 368                                 rmdir(xauthdir);
 369                                 return -1;
 370                         }
 371
 372                         if (timeout >= UINT_MAX - X11_TIMEOUT_SLACK)
 373                                 x11_timeout_real = UINT_MAX;
 374                         else
 375                                 x11_timeout_real = timeout + X11_TIMEOUT_SLACK;
 376                         if ((r = snprintf(cmd, sizeof(cmd),
 377                             "%s -f %s generate %s " SSH_X11_PROTO
 378                             " untrusted timeout %u 2>" _PATH_DEVNULL,
 379                             xauth_path, xauthfile, display,
 380                             x11_timeout_real)) < 0 ||
 381                             (size_t)r >= sizeof(cmd))
 382                                 fatal("%s: cmd too long", __func__);
 383                         debug2("%s: %s", __func__, cmd);
 384                         if (x11_refuse_time == 0) {
 385                                 now = monotime() + 1;
 386                                 if (UINT_MAX - timeout < now)
 387                                         x11_refuse_time = UINT_MAX;
 388                                 else
 389                                         x11_refuse_time = now + timeout;
 390                                 channel_set_x11_refuse_time(x11_refuse_time);
 391                         }
 392                         if (system(cmd) == 0)
 393                                 generated = 1;
 394                 }
 395
 396                 /*
 397                  * When in untrusted mode, we read the cookie only if it was
 398                  * successfully generated as an untrusted one in the step
 399                  * above.
 400                  */
 401                 if (trusted || generated) {
 402                         snprintf(cmd, sizeof(cmd),
 403                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 404                             xauth_path,
 405                             generated ? "-f " : "" ,
 406                             generated ? xauthfile : "",
 407                             display);
 408                         debug2("x11_get_proto: %s", cmd);
 409                         f = popen(cmd, "r");
 410                         if (f && fgets(line, sizeof(line), f) &&
 411                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 412                                 got_data = 1;
 413                         if (f)
 414                                 pclose(f);
 415                 }
 416         }
 417
 418         if (do_unlink) {
 419                 unlink(xauthfile);
 420                 rmdir(xauthdir);
 421         }
 422
 423         /* Don't fall back to fake X11 data for untrusted forwarding */
 424         if (!trusted && !got_data) {
 425                 error("Warning: untrusted X11 forwarding setup failed: "
 426                     "xauth key data not generated");
 427                 return -1;
 428         }
 429
 430         /*
 431          * If we didn't get authentication data, just make up some
 432          * data.  The forwarding code will check the validity of the
 433          * response anyway, and substitute this data.  The X11
 434          * server, however, will ignore this fake data and use
 435          * whatever authentication mechanisms it was using otherwise
 436          * for the local connection.
 437          */
 438         if (!got_data) {
 439                 u_int32_t rnd = 0;
 440
 441                 logit("Warning: No xauth data; "
 442                     "using fake authentication data for X11 forwarding.");
 443                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 444                 for (i = 0; i < 16; i++) {
 445                         if (i % 4 == 0)
 446                                 rnd = arc4random();
 447                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 448                             rnd & 0xff);
 449                         rnd >>= 8;
 450                 }
 451         }
 452
 453         return 0;
 454 }
 455
 456 /*
 457  * This is called when the interactive is entered.  This checks if there is
 458  * an EOF coming on stdin.  We must check this explicitly, as select() does
 459  * not appear to wake up when redirecting from /dev/null.
 460  */
 461
 462 static void
 463 client_check_initial_eof_on_stdin(void)
 464 {
 465         int len;
 466         char buf[1];
 467
 468         /*
 469          * If standard input is to be "redirected from /dev/null", we simply
 470          * mark that we have seen an EOF and send an EOF message to the
 471          * server. Otherwise, we try to read a single character; it appears
 472          * that for some files, such /dev/null, select() never wakes up for
 473          * read for this descriptor, which means that we never get EOF.  This
 474          * way we will get the EOF if stdin comes from /dev/null or similar.
 475          */
 476         if (stdin_null_flag) {
 477                 /* Fake EOF on stdin. */
 478                 debug("Sending eof.");
 479                 stdin_eof = 1;
 480                 packet_start(SSH_CMSG_EOF);
 481                 packet_send();
 482         } else {
 483                 enter_non_blocking();
 484
 485                 /* Check for immediate EOF on stdin. */
 486                 len = read(fileno(stdin), buf, 1);
 487                 if (len == 0) {
 488                         /*
 489                          * EOF.  Record that we have seen it and send
 490                          * EOF to server.
 491                          */
 492                         debug("Sending eof.");
 493                         stdin_eof = 1;
 494                         packet_start(SSH_CMSG_EOF);
 495                         packet_send();
 496                 } else if (len > 0) {
 497                         /*
 498                          * Got data.  We must store the data in the buffer,
 499                          * and also process it as an escape character if
 500                          * appropriate.
 501                          */
 502                         if ((u_char) buf[0] == escape_char1)
 503                                 escape_pending1 = 1;
 504                         else
 505                                 buffer_append(&stdin_buffer, buf, 1);
 506                 }
 507                 leave_non_blocking();
 508         }
 509 }
 510
 511
 512 /*
 513  * Make packets from buffered stdin data, and buffer them for sending to the
 514  * connection.
 515  */
 516
 517 static void
 518 client_make_packets_from_stdin_data(void)
 519 {
 520         u_int len;
 521
 522         /* Send buffered stdin data to the server. */
 523         while (buffer_len(&stdin_buffer) > 0 &&
 524             packet_not_very_much_data_to_write()) {
 525                 len = buffer_len(&stdin_buffer);
 526                 /* Keep the packets at reasonable size. */
 527                 if (len > packet_get_maxsize())
 528                         len = packet_get_maxsize();
 529                 packet_start(SSH_CMSG_STDIN_DATA);
 530                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 531                 packet_send();
 532                 buffer_consume(&stdin_buffer, len);
 533                 /* If we have a pending EOF, send it now. */
 534                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 535                         packet_start(SSH_CMSG_EOF);
 536                         packet_send();
 537                 }
 538         }
 539 }
 540
 541 /*
 542  * Checks if the client window has changed, and sends a packet about it to
 543  * the server if so.  The actual change is detected elsewhere (by a software
 544  * interrupt on Unix); this just checks the flag and sends a message if
 545  * appropriate.
 546  */
 547
 548 static void
 549 client_check_window_change(void)
 550 {
 551         struct winsize ws;
 552
 553         if (! received_window_change_signal)
 554                 return;
 555         /** XXX race */
 556         received_window_change_signal = 0;
 557
 558         debug2("client_check_window_change: changed");
 559
 560         if (compat20) {
 561                 channel_send_window_changes();
 562         } else {
 563                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 564                         return;
 565                 packet_start(SSH_CMSG_WINDOW_SIZE);
 566                 packet_put_int((u_int)ws.ws_row);
 567                 packet_put_int((u_int)ws.ws_col);
 568                 packet_put_int((u_int)ws.ws_xpixel);
 569                 packet_put_int((u_int)ws.ws_ypixel);
 570                 packet_send();
 571         }
 572 }
 573
 574 static int
 575 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 576 {
 577         struct global_confirm *gc;
 578
 579         if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
 580                 return 0;
 581         if (gc->cb != NULL)
 582                 gc->cb(type, seq, gc->ctx);
 583         if (--gc->ref_count <= 0) {
 584                 TAILQ_REMOVE(&global_confirms, gc, entry);
 585                 explicit_bzero(gc, sizeof(*gc));
 586                 free(gc);
 587         }
 588
 589         packet_set_alive_timeouts(0);
 590         return 0;
 591 }
 592
 593 static void
 594 server_alive_check(void)
 595 {
 596         if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
 597                 logit("Timeout, server %s not responding.", host);
 598                 cleanup_exit(255);
 599         }
 600         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 601         packet_put_cstring("keepalive@openssh.com");
 602         packet_put_char(1);     /* boolean: want reply */
 603         packet_send();
 604         /* Insert an empty placeholder to maintain ordering */
 605         client_register_global_confirm(NULL, NULL);
 606 }
 607
 608 /*
 609  * Waits until the client can do something (some data becomes available on
 610  * one of the file descriptors).
 611  */
 612 static void
 613 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 614     int *maxfdp, u_int *nallocp, int rekeying)
 615 {
 616         struct timeval tv, *tvp;
 617         int timeout_secs;
 618         time_t minwait_secs = 0, server_alive_time = 0, now = monotime();
 619         int ret;
 620
 621         /* Add any selections by the channel mechanism. */
 622         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
 623             &minwait_secs, rekeying);
 624
 625         if (!compat20) {
 626                 /* Read from the connection, unless our buffers are full. */
 627                 if (buffer_len(&stdout_buffer) < buffer_high &&
 628                     buffer_len(&stderr_buffer) < buffer_high &&
 629                     channel_not_very_much_buffered_data())
 630                         FD_SET(connection_in, *readsetp);
 631                 /*
 632                  * Read from stdin, unless we have seen EOF or have very much
 633                  * buffered data to send to the server.
 634                  */
 635                 if (!stdin_eof && packet_not_very_much_data_to_write())
 636                         FD_SET(fileno(stdin), *readsetp);
 637
 638                 /* Select stdout/stderr if have data in buffer. */
 639                 if (buffer_len(&stdout_buffer) > 0)
 640                         FD_SET(fileno(stdout), *writesetp);
 641                 if (buffer_len(&stderr_buffer) > 0)
 642                         FD_SET(fileno(stderr), *writesetp);
 643         } else {
 644                 /* channel_prepare_select could have closed the last channel */
 645                 if (session_closed && !channel_still_open() &&
 646                     !packet_have_data_to_write()) {
 647                         /* clear mask since we did not call select() */
 648                         memset(*readsetp, 0, *nallocp);
 649                         memset(*writesetp, 0, *nallocp);
 650                         return;
 651                 } else {
 652                         FD_SET(connection_in, *readsetp);
 653                 }
 654         }
 655
 656         /* Select server connection if have data to write to the server. */
 657         if (packet_have_data_to_write())
 658                 FD_SET(connection_out, *writesetp);
 659
 660         /*
 661          * Wait for something to happen.  This will suspend the process until
 662          * some selected descriptor can be read, written, or has some other
 663          * event pending, or a timeout expires.
 664          */
 665
 666         timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
 667         if (options.server_alive_interval > 0 && compat20) {
 668                 timeout_secs = options.server_alive_interval;
 669                 server_alive_time = now + options.server_alive_interval;
 670         }
 671         if (options.rekey_interval > 0 && compat20 && !rekeying)
 672                 timeout_secs = MIN(timeout_secs, packet_get_rekey_timeout());
 673         set_control_persist_exit_time();
 674         if (control_persist_exit_time > 0) {
 675                 timeout_secs = MIN(timeout_secs,
 676                         control_persist_exit_time - now);
 677                 if (timeout_secs < 0)
 678                         timeout_secs = 0;
 679         }
 680         if (minwait_secs != 0)
 681                 timeout_secs = MIN(timeout_secs, (int)minwait_secs);
 682         if (timeout_secs == INT_MAX)
 683                 tvp = NULL;
 684         else {
 685                 tv.tv_sec = timeout_secs;
 686                 tv.tv_usec = 0;
 687                 tvp = &tv;
 688         }
 689
 690         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 691         if (ret < 0) {
 692                 char buf[100];
 693
 694                 /*
 695                  * We have to clear the select masks, because we return.
 696                  * We have to return, because the mainloop checks for the flags
 697                  * set by the signal handlers.
 698                  */
 699                 memset(*readsetp, 0, *nallocp);
 700                 memset(*writesetp, 0, *nallocp);
 701
 702                 if (errno == EINTR)
 703                         return;
 704                 /* Note: we might still have data in the buffers. */
 705                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 706                 buffer_append(&stderr_buffer, buf, strlen(buf));
 707                 quit_pending = 1;
 708         } else if (ret == 0) {
 709                 /*
 710                  * Timeout.  Could have been either keepalive or rekeying.
 711                  * Keepalive we check here, rekeying is checked in clientloop.
 712                  */
 713                 if (server_alive_time != 0 && server_alive_time <= monotime())
 714                         server_alive_check();
 715         }
 716
 717 }
 718
 719 static void
 720 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 721 {
 722         /* Flush stdout and stderr buffers. */
 723         if (buffer_len(bout) > 0)
 724                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
 725                     buffer_len(bout));
 726         if (buffer_len(berr) > 0)
 727                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
 728                     buffer_len(berr));
 729
 730         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 731
 732         /*
 733          * Free (and clear) the buffer to reduce the amount of data that gets
 734          * written to swap.
 735          */
 736         buffer_free(bin);
 737         buffer_free(bout);
 738         buffer_free(berr);
 739
 740         /* Send the suspend signal to the program itself. */
 741         kill(getpid(), SIGTSTP);
 742
 743         /* Reset window sizes in case they have changed */
 744         received_window_change_signal = 1;
 745
 746         /* OK, we have been continued by the user. Reinitialize buffers. */
 747         buffer_init(bin);
 748         buffer_init(bout);
 749         buffer_init(berr);
 750
 751         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 752 }
 753
 754 static void
 755 client_process_net_input(fd_set *readset)
 756 {
 757         int len;
 758         char buf[SSH_IOBUFSZ];
 759
 760         /*
 761          * Read input from the server, and add any such data to the buffer of
 762          * the packet subsystem.
 763          */
 764         if (FD_ISSET(connection_in, readset)) {
 765                 /* Read as much as possible. */
 766                 len = read(connection_in, buf, sizeof(buf));
 767                 if (len == 0) {
 768                         /*
 769                          * Received EOF.  The remote host has closed the
 770                          * connection.
 771                          */
 772                         snprintf(buf, sizeof buf,
 773                             "Connection to %.300s closed by remote host.\r\n",
 774                             host);
 775                         buffer_append(&stderr_buffer, buf, strlen(buf));
 776                         quit_pending = 1;
 777                         return;
 778                 }
 779                 /*
 780                  * There is a kernel bug on Solaris that causes select to
 781                  * sometimes wake up even though there is no data available.
 782                  */
 783                 if (len < 0 &&
 784                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 785                         len = 0;
 786
 787                 if (len < 0) {
 788                         /*
 789                          * An error has encountered.  Perhaps there is a
 790                          * network problem.
 791                          */
 792                         snprintf(buf, sizeof buf,
 793                             "Read from remote host %.300s: %.100s\r\n",
 794                             host, strerror(errno));
 795                         buffer_append(&stderr_buffer, buf, strlen(buf));
 796                         quit_pending = 1;
 797                         return;
 798                 }
 799                 packet_process_incoming(buf, len);
 800         }
 801 }
 802
 803 static void
 804 client_status_confirm(int type, Channel *c, void *ctx)
 805 {
 806         struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
 807         char errmsg[256];
 808         int tochan;
 809
 810         /*
 811          * If a TTY was explicitly requested, then a failure to allocate
 812          * one is fatal.
 813          */
 814         if (cr->action == CONFIRM_TTY &&
 815             (options.request_tty == REQUEST_TTY_FORCE ||
 816             options.request_tty == REQUEST_TTY_YES))
 817                 cr->action = CONFIRM_CLOSE;
 818
 819         /* XXX supress on mux _client_ quietmode */
 820         tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
 821             c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
 822
 823         if (type == SSH2_MSG_CHANNEL_SUCCESS) {
 824                 debug2("%s request accepted on channel %d",
 825                     cr->request_type, c->self);
 826         } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 827                 if (tochan) {
 828                         snprintf(errmsg, sizeof(errmsg),
 829                             "%s request failed\r\n", cr->request_type);
 830                 } else {
 831                         snprintf(errmsg, sizeof(errmsg),
 832                             "%s request failed on channel %d",
 833                             cr->request_type, c->self);
 834                 }
 835                 /* If error occurred on primary session channel, then exit */
 836                 if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
 837                         fatal("%s", errmsg);
 838                 /*
 839                  * If error occurred on mux client, append to
 840                  * their stderr.
 841                  */
 842                 if (tochan) {
 843                         buffer_append(&c->extended, errmsg,
 844                             strlen(errmsg));
 845                 } else
 846                         error("%s", errmsg);
 847                 if (cr->action == CONFIRM_TTY) {
 848                         /*
 849                          * If a TTY allocation error occurred, then arrange
 850                          * for the correct TTY to leave raw mode.
 851                          */
 852                         if (c->self == session_ident)
 853                                 leave_raw_mode(0);
 854                         else
 855                                 mux_tty_alloc_failed(c);
 856                 } else if (cr->action == CONFIRM_CLOSE) {
 857                         chan_read_failed(c);
 858                         chan_write_failed(c);
 859                 }
 860         }
 861         free(cr);
 862 }
 863
 864 static void
 865 client_abandon_status_confirm(Channel *c, void *ctx)
 866 {
 867         free(ctx);
 868 }
 869
 870 void
 871 client_expect_confirm(int id, const char *request,
 872     enum confirm_action action)
 873 {
 874         struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr));
 875
 876         cr->request_type = request;
 877         cr->action = action;
 878
 879         channel_register_status_confirm(id, client_status_confirm,
 880             client_abandon_status_confirm, cr);
 881 }
 882
 883 void
 884 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
 885 {
 886         struct global_confirm *gc, *last_gc;
 887
 888         /* Coalesce identical callbacks */
 889         last_gc = TAILQ_LAST(&global_confirms, global_confirms);
 890         if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
 891                 if (++last_gc->ref_count >= INT_MAX)
 892                         fatal("%s: last_gc->ref_count = %d",
 893                             __func__, last_gc->ref_count);
 894                 return;
 895         }
 896
 897         gc = xcalloc(1, sizeof(*gc));
 898         gc->cb = cb;
 899         gc->ctx = ctx;
 900         gc->ref_count = 1;
 901         TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
 902 }
 903
 904 static void
 905 process_cmdline(void)
 906 {
 907         void (*handler)(int);
 908         char *s, *cmd;
 909         int ok, delete = 0, local = 0, remote = 0, dynamic = 0;
 910         struct Forward fwd;
 911
 912         memset(&fwd, 0, sizeof(fwd));
 913
 914         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 915         handler = signal(SIGINT, SIG_IGN);
 916         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 917         if (s == NULL)
 918                 goto out;
 919         while (isspace((u_char)*s))
 920                 s++;
 921         if (*s == '-')
 922                 s++;    /* Skip cmdline '-', if any */
 923         if (*s == '\0')
 924                 goto out;
 925
 926         if (*s == 'h' || *s == 'H' || *s == '?') {
 927                 logit("Commands:");
 928                 logit("      -L[bind_address:]port:host:hostport    "
 929                     "Request local forward");
 930                 logit("      -R[bind_address:]port:host:hostport    "
 931                     "Request remote forward");
 932                 logit("      -D[bind_address:]port                  "
 933                     "Request dynamic forward");
 934                 logit("      -KL[bind_address:]port                 "
 935                     "Cancel local forward");
 936                 logit("      -KR[bind_address:]port                 "
 937                     "Cancel remote forward");
 938                 logit("      -KD[bind_address:]port                 "
 939                     "Cancel dynamic forward");
 940                 if (!options.permit_local_command)
 941                         goto out;
 942                 logit("      !args                                  "
 943                     "Execute local command");
 944                 goto out;
 945         }
 946
 947         if (*s == '!' && options.permit_local_command) {
 948                 s++;
 949                 ssh_local_cmd(s);
 950                 goto out;
 951         }
 952
 953         if (*s == 'K') {
 954                 delete = 1;
 955                 s++;
 956         }
 957         if (*s == 'L')
 958                 local = 1;
 959         else if (*s == 'R')
 960                 remote = 1;
 961         else if (*s == 'D')
 962                 dynamic = 1;
 963         else {
 964                 logit("Invalid command.");
 965                 goto out;
 966         }
 967
 968         if (delete && !compat20) {
 969                 logit("Not supported for SSH protocol version 1.");
 970                 goto out;
 971         }
 972
 973         while (isspace((u_char)*++s))
 974                 ;
 975
 976         /* XXX update list of forwards in options */
 977         if (delete) {
 978                 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */
 979                 if (!parse_forward(&fwd, s, 1, 0)) {
 980                         logit("Bad forwarding close specification.");
 981                         goto out;
 982                 }
 983                 if (remote)
 984                         ok = channel_request_rforward_cancel(&fwd) == 0;
 985                 else if (dynamic)
 986                         ok = channel_cancel_lport_listener(&fwd,
 987                             0, &options.fwd_opts) > 0;
 988                 else
 989                         ok = channel_cancel_lport_listener(&fwd,
 990                             CHANNEL_CANCEL_PORT_STATIC,
 991                             &options.fwd_opts) > 0;
 992                 if (!ok) {
 993                         logit("Unkown port forwarding.");
 994                         goto out;
 995                 }
 996                 logit("Canceled forwarding.");
 997         } else {
 998                 if (!parse_forward(&fwd, s, dynamic, remote)) {
 999                         logit("Bad forwarding specification.");
1000                         goto out;
1001                 }
1002                 if (local || dynamic) {
1003                         if (!channel_setup_local_fwd_listener(&fwd,
1004                             &options.fwd_opts)) {
1005                                 logit("Port forwarding failed.");
1006                                 goto out;
1007                         }
1008                 } else {
1009                         if (channel_request_remote_forwarding(&fwd) < 0) {
1010                                 logit("Port forwarding failed.");
1011                                 goto out;
1012                         }
1013                 }
1014                 logit("Forwarding port.");
1015         }
1016
1017 out:
1018         signal(SIGINT, handler);
1019         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1020         free(cmd);
1021         free(fwd.listen_host);
1022         free(fwd.listen_path);
1023         free(fwd.connect_host);
1024         free(fwd.connect_path);
1025 }
1026
1027 /* reasons to suppress output of an escape command in help output */
1028 #define SUPPRESS_NEVER          0       /* never suppress, always show */
1029 #define SUPPRESS_PROTO1         1       /* don't show in protocol 1 sessions */
1030 #define SUPPRESS_MUXCLIENT      2       /* don't show in mux client sessions */
1031 #define SUPPRESS_MUXMASTER      4       /* don't show in mux master sessions */
1032 #define SUPPRESS_SYSLOG         8       /* don't show when logging to syslog */
1033 struct escape_help_text {
1034         const char *cmd;
1035         const char *text;
1036         unsigned int flags;
1037 };
1038 static struct escape_help_text esc_txt[] = {
1039     {".",  "terminate session", SUPPRESS_MUXMASTER},
1040     {".",  "terminate connection (and any multiplexed sessions)",
1041         SUPPRESS_MUXCLIENT},
1042     {"B",  "send a BREAK to the remote system", SUPPRESS_PROTO1},
1043     {"C",  "open a command line", SUPPRESS_MUXCLIENT},
1044     {"R",  "request rekey", SUPPRESS_PROTO1},
1045     {"V/v",  "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT},
1046     {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT},
1047     {"#",  "list forwarded connections", SUPPRESS_NEVER},
1048     {"&",  "background ssh (when waiting for connections to terminate)",
1049         SUPPRESS_MUXCLIENT},
1050     {"?", "this message", SUPPRESS_NEVER},
1051 };
1052
1053 static void
1054 print_escape_help(Buffer *b, int escape_char, int protocol2, int mux_client,
1055     int using_stderr)
1056 {
1057         unsigned int i, suppress_flags;
1058         char string[1024];
1059
1060         snprintf(string, sizeof string, "%c?\r\n"
1061             "Supported escape sequences:\r\n", escape_char);
1062         buffer_append(b, string, strlen(string));
1063
1064         suppress_flags = (protocol2 ? 0 : SUPPRESS_PROTO1) |
1065             (mux_client ? SUPPRESS_MUXCLIENT : 0) |
1066             (mux_client ? 0 : SUPPRESS_MUXMASTER) |
1067             (using_stderr ? 0 : SUPPRESS_SYSLOG);
1068
1069         for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) {
1070                 if (esc_txt[i].flags & suppress_flags)
1071                         continue;
1072                 snprintf(string, sizeof string, " %c%-3s - %s\r\n",
1073                     escape_char, esc_txt[i].cmd, esc_txt[i].text);
1074                 buffer_append(b, string, strlen(string));
1075         }
1076
1077         snprintf(string, sizeof string,
1078             " %c%c   - send the escape character by typing it twice\r\n"
1079             "(Note that escapes are only recognized immediately after "
1080             "newline.)\r\n", escape_char, escape_char);
1081         buffer_append(b, string, strlen(string));
1082 }
1083
1084 /*
1085  * Process the characters one by one, call with c==NULL for proto1 case.
1086  */
1087 static int
1088 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
1089     char *buf, int len)
1090 {
1091         char string[1024];
1092         pid_t pid;
1093         int bytes = 0;
1094         u_int i;
1095         u_char ch;
1096         char *s;
1097         int *escape_pendingp, escape_char;
1098         struct escape_filter_ctx *efc;
1099
1100         if (c == NULL) {
1101                 escape_pendingp = &escape_pending1;
1102                 escape_char = escape_char1;
1103         } else {
1104                 if (c->filter_ctx == NULL)
1105                         return 0;
1106                 efc = (struct escape_filter_ctx *)c->filter_ctx;
1107                 escape_pendingp = &efc->escape_pending;
1108                 escape_char = efc->escape_char;
1109         }
1110
1111         if (len <= 0)
1112                 return (0);
1113
1114         for (i = 0; i < (u_int)len; i++) {
1115                 /* Get one character at a time. */
1116                 ch = buf[i];
1117
1118                 if (*escape_pendingp) {
1119                         /* We have previously seen an escape character. */
1120                         /* Clear the flag now. */
1121                         *escape_pendingp = 0;
1122
1123                         /* Process the escaped character. */
1124                         switch (ch) {
1125                         case '.':
1126                                 /* Terminate the connection. */
1127                                 snprintf(string, sizeof string, "%c.\r\n",
1128                                     escape_char);
1129                                 buffer_append(berr, string, strlen(string));
1130
1131                                 if (c && c->ctl_chan != -1) {
1132                                         chan_read_failed(c);
1133                                         chan_write_failed(c);
1134                                         if (c->detach_user)
1135                                                 c->detach_user(c->self, NULL);
1136                                         c->type = SSH_CHANNEL_ABANDONED;
1137                                         buffer_clear(&c->input);
1138                                         chan_ibuf_empty(c);
1139                                         return 0;
1140                                 } else
1141                                         quit_pending = 1;
1142                                 return -1;
1143
1144                         case 'Z' - 64:
1145                                 /* XXX support this for mux clients */
1146                                 if (c && c->ctl_chan != -1) {
1147                                         char b[16];
1148  noescape:
1149                                         if (ch == 'Z' - 64)
1150                                                 snprintf(b, sizeof b, "^Z");
1151                                         else
1152                                                 snprintf(b, sizeof b, "%c", ch);
1153                                         snprintf(string, sizeof string,
1154                                             "%c%s escape not available to "
1155                                             "multiplexed sessions\r\n",
1156                                             escape_char, b);
1157                                         buffer_append(berr, string,
1158                                             strlen(string));
1159                                         continue;
1160                                 }
1161                                 /* Suspend the program. Inform the user */
1162                                 snprintf(string, sizeof string,
1163                                     "%c^Z [suspend ssh]\r\n", escape_char);
1164                                 buffer_append(berr, string, strlen(string));
1165
1166                                 /* Restore terminal modes and suspend. */
1167                                 client_suspend_self(bin, bout, berr);
1168
1169                                 /* We have been continued. */
1170                                 continue;
1171
1172                         case 'B':
1173                                 if (compat20) {
1174                                         snprintf(string, sizeof string,
1175                                             "%cB\r\n", escape_char);
1176                                         buffer_append(berr, string,
1177                                             strlen(string));
1178                                         channel_request_start(c->self,
1179                                             "break", 0);
1180                                         packet_put_int(1000);
1181                                         packet_send();
1182                                 }
1183                                 continue;
1184
1185                         case 'R':
1186                                 if (compat20) {
1187                                         if (datafellows & SSH_BUG_NOREKEY)
1188                                                 logit("Server does not "
1189                                                     "support re-keying");
1190                                         else
1191                                                 need_rekeying = 1;
1192                                 }
1193                                 continue;
1194
1195                         case 'V':
1196                                 /* FALLTHROUGH */
1197                         case 'v':
1198                                 if (c && c->ctl_chan != -1)
1199                                         goto noescape;
1200                                 if (!log_is_on_stderr()) {
1201                                         snprintf(string, sizeof string,
1202                                             "%c%c [Logging to syslog]\r\n",
1203                                              escape_char, ch);
1204                                         buffer_append(berr, string,
1205                                             strlen(string));
1206                                         continue;
1207                                 }
1208                                 if (ch == 'V' && options.log_level >
1209                                     SYSLOG_LEVEL_QUIET)
1210                                         log_change_level(--options.log_level);
1211                                 if (ch == 'v' && options.log_level <
1212                                     SYSLOG_LEVEL_DEBUG3)
1213                                         log_change_level(++options.log_level);
1214                                 snprintf(string, sizeof string,
1215                                     "%c%c [LogLevel %s]\r\n", escape_char, ch,
1216                                     log_level_name(options.log_level));
1217                                 buffer_append(berr, string, strlen(string));
1218                                 continue;
1219
1220                         case '&':
1221                                 if (c && c->ctl_chan != -1)
1222                                         goto noescape;
1223                                 /*
1224                                  * Detach the program (continue to serve
1225                                  * connections, but put in background and no
1226                                  * more new connections).
1227                                  */
1228                                 /* Restore tty modes. */
1229                                 leave_raw_mode(
1230                                     options.request_tty == REQUEST_TTY_FORCE);
1231
1232                                 /* Stop listening for new connections. */
1233                                 channel_stop_listening();
1234
1235                                 snprintf(string, sizeof string,
1236                                     "%c& [backgrounded]\n", escape_char);
1237                                 buffer_append(berr, string, strlen(string));
1238
1239                                 /* Fork into background. */
1240                                 pid = fork();
1241                                 if (pid < 0) {
1242                                         error("fork: %.100s", strerror(errno));
1243                                         continue;
1244                                 }
1245                                 if (pid != 0) { /* This is the parent. */
1246                                         /* The parent just exits. */
1247                                         exit(0);
1248                                 }
1249                                 /* The child continues serving connections. */
1250                                 if (compat20) {
1251                                         buffer_append(bin, "\004", 1);
1252                                         /* fake EOF on stdin */
1253                                         return -1;
1254                                 } else if (!stdin_eof) {
1255                                         /*
1256                                          * Sending SSH_CMSG_EOF alone does not
1257                                          * always appear to be enough.  So we
1258                                          * try to send an EOF character first.
1259                                          */
1260                                         packet_start(SSH_CMSG_STDIN_DATA);
1261                                         packet_put_string("\004", 1);
1262                                         packet_send();
1263                                         /* Close stdin. */
1264                                         stdin_eof = 1;
1265                                         if (buffer_len(bin) == 0) {
1266                                                 packet_start(SSH_CMSG_EOF);
1267                                                 packet_send();
1268                                         }
1269                                 }
1270                                 continue;
1271
1272                         case '?':
1273                                 print_escape_help(berr, escape_char, compat20,
1274                                     (c && c->ctl_chan != -1),
1275                                     log_is_on_stderr());
1276                                 continue;
1277
1278                         case '#':
1279                                 snprintf(string, sizeof string, "%c#\r\n",
1280                                     escape_char);
1281                                 buffer_append(berr, string, strlen(string));
1282                                 s = channel_open_message();
1283                                 buffer_append(berr, s, strlen(s));
1284                                 free(s);
1285                                 continue;
1286
1287                         case 'C':
1288                                 if (c && c->ctl_chan != -1)
1289                                         goto noescape;
1290                                 process_cmdline();
1291                                 continue;
1292
1293                         default:
1294                                 if (ch != escape_char) {
1295                                         buffer_put_char(bin, escape_char);
1296                                         bytes++;
1297                                 }
1298                                 /* Escaped characters fall through here */
1299                                 break;
1300                         }
1301                 } else {
1302                         /*
1303                          * The previous character was not an escape char.
1304                          * Check if this is an escape.
1305                          */
1306                         if (last_was_cr && ch == escape_char) {
1307                                 /*
1308                                  * It is. Set the flag and continue to
1309                                  * next character.
1310                                  */
1311                                 *escape_pendingp = 1;
1312                                 continue;
1313                         }
1314                 }
1315
1316                 /*
1317                  * Normal character.  Record whether it was a newline,
1318                  * and append it to the buffer.
1319                  */
1320                 last_was_cr = (ch == '\r' || ch == '\n');
1321                 buffer_put_char(bin, ch);
1322                 bytes++;
1323         }
1324         return bytes;
1325 }
1326
1327 static void
1328 client_process_input(fd_set *readset)
1329 {
1330         int len;
1331         char buf[SSH_IOBUFSZ];
1332
1333         /* Read input from stdin. */
1334         if (FD_ISSET(fileno(stdin), readset)) {
1335                 /* Read as much as possible. */
1336                 len = read(fileno(stdin), buf, sizeof(buf));
1337                 if (len < 0 &&
1338                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1339                         return;         /* we'll try again later */
1340                 if (len <= 0) {
1341                         /*
1342                          * Received EOF or error.  They are treated
1343                          * similarly, except that an error message is printed
1344                          * if it was an error condition.
1345                          */
1346                         if (len < 0) {
1347                                 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1348                                     strerror(errno));
1349                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1350                         }
1351                         /* Mark that we have seen EOF. */
1352                         stdin_eof = 1;
1353                         /*
1354                          * Send an EOF message to the server unless there is
1355                          * data in the buffer.  If there is data in the
1356                          * buffer, no message will be sent now.  Code
1357                          * elsewhere will send the EOF when the buffer
1358                          * becomes empty if stdin_eof is set.
1359                          */
1360                         if (buffer_len(&stdin_buffer) == 0) {
1361                                 packet_start(SSH_CMSG_EOF);
1362                                 packet_send();
1363                         }
1364                 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1365                         /*
1366                          * Normal successful read, and no escape character.
1367                          * Just append the data to buffer.
1368                          */
1369                         buffer_append(&stdin_buffer, buf, len);
1370                 } else {
1371                         /*
1372                          * Normal, successful read.  But we have an escape
1373                          * character and have to process the characters one
1374                          * by one.
1375                          */
1376                         if (process_escapes(NULL, &stdin_buffer,
1377                             &stdout_buffer, &stderr_buffer, buf, len) == -1)
1378                                 return;
1379                 }
1380         }
1381 }
1382
1383 static void
1384 client_process_output(fd_set *writeset)
1385 {
1386         int len;
1387         char buf[100];
1388
1389         /* Write buffered output to stdout. */
1390         if (FD_ISSET(fileno(stdout), writeset)) {
1391                 /* Write as much data as possible. */
1392                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1393                     buffer_len(&stdout_buffer));
1394                 if (len <= 0) {
1395                         if (errno == EINTR || errno == EAGAIN ||
1396                             errno == EWOULDBLOCK)
1397                                 len = 0;
1398                         else {
1399                                 /*
1400                                  * An error or EOF was encountered.  Put an
1401                                  * error message to stderr buffer.
1402                                  */
1403                                 snprintf(buf, sizeof buf,
1404                                     "write stdout: %.50s\r\n", strerror(errno));
1405                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1406                                 quit_pending = 1;
1407                                 return;
1408                         }
1409                 }
1410                 /* Consume printed data from the buffer. */
1411                 buffer_consume(&stdout_buffer, len);
1412         }
1413         /* Write buffered output to stderr. */
1414         if (FD_ISSET(fileno(stderr), writeset)) {
1415                 /* Write as much data as possible. */
1416                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1417                     buffer_len(&stderr_buffer));
1418                 if (len <= 0) {
1419                         if (errno == EINTR || errno == EAGAIN ||
1420                             errno == EWOULDBLOCK)
1421                                 len = 0;
1422                         else {
1423                                 /*
1424                                  * EOF or error, but can't even print
1425                                  * error message.
1426                                  */
1427                                 quit_pending = 1;
1428                                 return;
1429                         }
1430                 }
1431                 /* Consume printed characters from the buffer. */
1432                 buffer_consume(&stderr_buffer, len);
1433         }
1434 }
1435
1436 /*
1437  * Get packets from the connection input buffer, and process them as long as
1438  * there are packets available.
1439  *
1440  * Any unknown packets received during the actual
1441  * session cause the session to terminate.  This is
1442  * intended to make debugging easier since no
1443  * confirmations are sent.  Any compatible protocol
1444  * extensions must be negotiated during the
1445  * preparatory phase.
1446  */
1447
1448 static void
1449 client_process_buffered_input_packets(void)
1450 {
1451         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, active_state);
1452 }
1453
1454 /* scan buf[] for '~' before sending data to the peer */
1455
1456 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1457 void *
1458 client_new_escape_filter_ctx(int escape_char)
1459 {
1460         struct escape_filter_ctx *ret;
1461
1462         ret = xcalloc(1, sizeof(*ret));
1463         ret->escape_pending = 0;
1464         ret->escape_char = escape_char;
1465         return (void *)ret;
1466 }
1467
1468 /* Free the escape filter context on channel free */
1469 void
1470 client_filter_cleanup(int cid, void *ctx)
1471 {
1472         free(ctx);
1473 }
1474
1475 int
1476 client_simple_escape_filter(Channel *c, char *buf, int len)
1477 {
1478         if (c->extended_usage != CHAN_EXTENDED_WRITE)
1479                 return 0;
1480
1481         return process_escapes(c, &c->input, &c->output, &c->extended,
1482             buf, len);
1483 }
1484
1485 static void
1486 client_channel_closed(int id, void *arg)
1487 {
1488         channel_cancel_cleanup(id);
1489         session_closed = 1;
1490         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1491 }
1492
1493 /*
1494  * Implements the interactive session with the server.  This is called after
1495  * the user has been authenticated, and a command has been started on the
1496  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1497  * used as an escape character for terminating or suspending the session.
1498  */
1499
1500 int
1501 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1502 {
1503         fd_set *readset = NULL, *writeset = NULL;
1504         double start_time, total_time;
1505         int r, max_fd = 0, max_fd2 = 0, len;
1506         u_int64_t ibytes, obytes;
1507         u_int nalloc = 0;
1508         char buf[100];
1509
1510         debug("Entering interactive session.");
1511
1512         if (options.control_master &&
1513             ! option_clear_or_none(options.control_path)) {
1514                 debug("pledge: id");
1515                 if (pledge("stdio rpath wpath cpath unix inet dns proc exec id tty",
1516                     NULL) == -1)
1517                         fatal("%s pledge(): %s", __func__, strerror(errno));
1518
1519         } else if (options.forward_x11 || options.permit_local_command) {
1520                 debug("pledge: exec");
1521                 if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty",
1522                     NULL) == -1)
1523                         fatal("%s pledge(): %s", __func__, strerror(errno));
1524
1525         } else if (options.update_hostkeys) {
1526                 debug("pledge: filesystem full");
1527                 if (pledge("stdio rpath wpath cpath unix inet dns proc tty",
1528                     NULL) == -1)
1529                         fatal("%s pledge(): %s", __func__, strerror(errno));
1530
1531         } else if (! option_clear_or_none(options.proxy_command)) {
1532                 debug("pledge: proc");
1533                 if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1)
1534                         fatal("%s pledge(): %s", __func__, strerror(errno));
1535
1536         } else {
1537                 debug("pledge: network");
1538                 if (pledge("stdio unix inet dns tty", NULL) == -1)
1539                         fatal("%s pledge(): %s", __func__, strerror(errno));
1540         }
1541
1542         start_time = get_current_time();
1543
1544         /* Initialize variables. */
1545         escape_pending1 = 0;
1546         last_was_cr = 1;
1547         exit_status = -1;
1548         stdin_eof = 0;
1549         buffer_high = 64 * 1024;
1550         connection_in = packet_get_connection_in();
1551         connection_out = packet_get_connection_out();
1552         max_fd = MAX(connection_in, connection_out);
1553
1554         if (!compat20) {
1555                 /* enable nonblocking unless tty */
1556                 if (!isatty(fileno(stdin)))
1557                         set_nonblock(fileno(stdin));
1558                 if (!isatty(fileno(stdout)))
1559                         set_nonblock(fileno(stdout));
1560                 if (!isatty(fileno(stderr)))
1561                         set_nonblock(fileno(stderr));
1562                 max_fd = MAX(max_fd, fileno(stdin));
1563                 max_fd = MAX(max_fd, fileno(stdout));
1564                 max_fd = MAX(max_fd, fileno(stderr));
1565         }
1566         quit_pending = 0;
1567         escape_char1 = escape_char_arg;
1568
1569         /* Initialize buffers. */
1570         buffer_init(&stdin_buffer);
1571         buffer_init(&stdout_buffer);
1572         buffer_init(&stderr_buffer);
1573
1574         client_init_dispatch();
1575
1576         /*
1577          * Set signal handlers, (e.g. to restore non-blocking mode)
1578          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1579          */
1580         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1581                 signal(SIGHUP, signal_handler);
1582         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1583                 signal(SIGINT, signal_handler);
1584         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1585                 signal(SIGQUIT, signal_handler);
1586         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1587                 signal(SIGTERM, signal_handler);
1588         signal(SIGWINCH, window_change_handler);
1589
1590         if (have_pty)
1591                 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1592
1593         if (compat20) {
1594                 session_ident = ssh2_chan_id;
1595                 if (session_ident != -1) {
1596                         if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1597                                 channel_register_filter(session_ident,
1598                                     client_simple_escape_filter, NULL,
1599                                     client_filter_cleanup,
1600                                     client_new_escape_filter_ctx(
1601                                     escape_char_arg));
1602                         }
1603                         channel_register_cleanup(session_ident,
1604                             client_channel_closed, 0);
1605                 }
1606         } else {
1607                 /* Check if we should immediately send eof on stdin. */
1608                 client_check_initial_eof_on_stdin();
1609         }
1610
1611         /* Main loop of the client for the interactive session mode. */
1612         while (!quit_pending) {
1613
1614                 /* Process buffered packets sent by the server. */
1615                 client_process_buffered_input_packets();
1616
1617                 if (compat20 && session_closed && !channel_still_open())
1618                         break;
1619
1620                 if (ssh_packet_is_rekeying(active_state)) {
1621                         debug("rekeying in progress");
1622                 } else if (need_rekeying) {
1623                         /* manual rekey request */
1624                         debug("need rekeying");
1625                         if ((r = kex_start_rekex(active_state)) != 0)
1626                                 fatal("%s: kex_start_rekex: %s", __func__,
1627                                     ssh_err(r));
1628                         need_rekeying = 0;
1629                 } else {
1630                         /*
1631                          * Make packets of buffered stdin data, and buffer
1632                          * them for sending to the server.
1633                          */
1634                         if (!compat20)
1635                                 client_make_packets_from_stdin_data();
1636
1637                         /*
1638                          * Make packets from buffered channel data, and
1639                          * enqueue them for sending to the server.
1640                          */
1641                         if (packet_not_very_much_data_to_write())
1642                                 channel_output_poll();
1643
1644                         /*
1645                          * Check if the window size has changed, and buffer a
1646                          * message about it to the server if so.
1647                          */
1648                         client_check_window_change();
1649
1650                         if (quit_pending)
1651                                 break;
1652                 }
1653                 /*
1654                  * Wait until we have something to do (something becomes
1655                  * available on one of the descriptors).
1656                  */
1657                 max_fd2 = max_fd;
1658                 client_wait_until_can_do_something(&readset, &writeset,
1659                     &max_fd2, &nalloc, ssh_packet_is_rekeying(active_state));
1660
1661                 if (quit_pending)
1662                         break;
1663
1664                 /* Do channel operations unless rekeying in progress. */
1665                 if (!ssh_packet_is_rekeying(active_state))
1666                         channel_after_select(readset, writeset);
1667
1668                 /* Buffer input from the connection.  */
1669                 client_process_net_input(readset);
1670
1671                 if (quit_pending)
1672                         break;
1673
1674                 if (!compat20) {
1675                         /* Buffer data from stdin */
1676                         client_process_input(readset);
1677                         /*
1678                          * Process output to stdout and stderr.  Output to
1679                          * the connection is processed elsewhere (above).
1680                          */
1681                         client_process_output(writeset);
1682                 }
1683
1684                 /*
1685                  * Send as much buffered packet data as possible to the
1686                  * sender.
1687                  */
1688                 if (FD_ISSET(connection_out, writeset))
1689                         packet_write_poll();
1690
1691                 /*
1692                  * If we are a backgrounded control master, and the
1693                  * timeout has expired without any active client
1694                  * connections, then quit.
1695                  */
1696                 if (control_persist_exit_time > 0) {
1697                         if (monotime() >= control_persist_exit_time) {
1698                                 debug("ControlPersist timeout expired");
1699                                 break;
1700                         }
1701                 }
1702         }
1703         free(readset);
1704         free(writeset);
1705
1706         /* Terminate the session. */
1707
1708         /* Stop watching for window change. */
1709         signal(SIGWINCH, SIG_DFL);
1710
1711         if (compat20) {
1712                 packet_start(SSH2_MSG_DISCONNECT);
1713                 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1714                 packet_put_cstring("disconnected by user");
1715                 packet_put_cstring(""); /* language tag */
1716                 packet_send();
1717                 packet_write_wait();
1718         }
1719
1720         channel_free_all();
1721
1722         if (have_pty)
1723                 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1724
1725         /* restore blocking io */
1726         if (!isatty(fileno(stdin)))
1727                 unset_nonblock(fileno(stdin));
1728         if (!isatty(fileno(stdout)))
1729                 unset_nonblock(fileno(stdout));
1730         if (!isatty(fileno(stderr)))
1731                 unset_nonblock(fileno(stderr));
1732
1733         /*
1734          * If there was no shell or command requested, there will be no remote
1735          * exit status to be returned.  In that case, clear error code if the
1736          * connection was deliberately terminated at this end.
1737          */
1738         if (no_shell_flag && received_signal == SIGTERM) {
1739                 received_signal = 0;
1740                 exit_status = 0;
1741         }
1742
1743         if (received_signal)
1744                 fatal("Killed by signal %d.", (int) received_signal);
1745
1746         /*
1747          * In interactive mode (with pseudo tty) display a message indicating
1748          * that the connection has been closed.
1749          */
1750         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1751                 snprintf(buf, sizeof buf,
1752                     "Connection to %.64s closed.\r\n", host);
1753                 buffer_append(&stderr_buffer, buf, strlen(buf));
1754         }
1755
1756         /* Output any buffered data for stdout. */
1757         if (buffer_len(&stdout_buffer) > 0) {
1758                 len = atomicio(vwrite, fileno(stdout),
1759                     buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer));
1760                 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer))
1761                         error("Write failed flushing stdout buffer.");
1762                 else
1763                         buffer_consume(&stdout_buffer, len);
1764         }
1765
1766         /* Output any buffered data for stderr. */
1767         if (buffer_len(&stderr_buffer) > 0) {
1768                 len = atomicio(vwrite, fileno(stderr),
1769                     buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer));
1770                 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer))
1771                         error("Write failed flushing stderr buffer.");
1772                 else
1773                         buffer_consume(&stderr_buffer, len);
1774         }
1775
1776         /* Clear and free any buffers. */
1777         explicit_bzero(buf, sizeof(buf));
1778         buffer_free(&stdin_buffer);
1779         buffer_free(&stdout_buffer);
1780         buffer_free(&stderr_buffer);
1781
1782         /* Report bytes transferred, and transfer rates. */
1783         total_time = get_current_time() - start_time;
1784         packet_get_bytes(&ibytes, &obytes);
1785         verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1786             (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1787         if (total_time > 0)
1788                 verbose("Bytes per second: sent %.1f, received %.1f",
1789                     obytes / total_time, ibytes / total_time);
1790         /* Return the exit status of the program. */
1791         debug("Exit status %d", exit_status);
1792         return exit_status;
1793 }
1794
1795 /*********/
1796
1797 static int
1798 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1799 {
1800         u_int data_len;
1801         char *data = packet_get_string(&data_len);
1802         packet_check_eom();
1803         buffer_append(&stdout_buffer, data, data_len);
1804         explicit_bzero(data, data_len);
1805         free(data);
1806         return 0;
1807 }
1808 static int
1809 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1810 {
1811         u_int data_len;
1812         char *data = packet_get_string(&data_len);
1813         packet_check_eom();
1814         buffer_append(&stderr_buffer, data, data_len);
1815         explicit_bzero(data, data_len);
1816         free(data);
1817         return 0;
1818 }
1819 static int
1820 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1821 {
1822         exit_status = packet_get_int();
1823         packet_check_eom();
1824         /* Acknowledge the exit. */
1825         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1826         packet_send();
1827         /*
1828          * Must wait for packet to be sent since we are
1829          * exiting the loop.
1830          */
1831         packet_write_wait();
1832         /* Flag that we want to exit. */
1833         quit_pending = 1;
1834         return 0;
1835 }
1836
1837 static int
1838 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1839 {
1840         Channel *c = NULL;
1841         int r, remote_id, sock;
1842
1843         /* Read the remote channel number from the message. */
1844         remote_id = packet_get_int();
1845         packet_check_eom();
1846
1847         /*
1848          * Get a connection to the local authentication agent (this may again
1849          * get forwarded).
1850          */
1851         if ((r = ssh_get_authentication_socket(&sock)) != 0 &&
1852             r != SSH_ERR_AGENT_NOT_PRESENT)
1853                 debug("%s: ssh_get_authentication_socket: %s",
1854                     __func__, ssh_err(r));
1855
1856
1857         /*
1858          * If we could not connect the agent, send an error message back to
1859          * the server. This should never happen unless the agent dies,
1860          * because authentication forwarding is only enabled if we have an
1861          * agent.
1862          */
1863         if (sock >= 0) {
1864                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1865                     -1, 0, 0, 0, "authentication agent connection", 1);
1866                 c->remote_id = remote_id;
1867                 c->force_drain = 1;
1868         }
1869         if (c == NULL) {
1870                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1871                 packet_put_int(remote_id);
1872         } else {
1873                 /* Send a confirmation to the remote host. */
1874                 debug("Forwarding authentication connection.");
1875                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1876                 packet_put_int(remote_id);
1877                 packet_put_int(c->self);
1878         }
1879         packet_send();
1880         return 0;
1881 }
1882
1883 static Channel *
1884 client_request_forwarded_tcpip(const char *request_type, int rchan)
1885 {
1886         Channel *c = NULL;
1887         char *listen_address, *originator_address;
1888         u_short listen_port, originator_port;
1889
1890         /* Get rest of the packet */
1891         listen_address = packet_get_string(NULL);
1892         listen_port = packet_get_int();
1893         originator_address = packet_get_string(NULL);
1894         originator_port = packet_get_int();
1895         packet_check_eom();
1896
1897         debug("%s: listen %s port %d, originator %s port %d", __func__,
1898             listen_address, listen_port, originator_address, originator_port);
1899
1900         c = channel_connect_by_listen_address(listen_address, listen_port,
1901             "forwarded-tcpip", originator_address);
1902
1903         free(originator_address);
1904         free(listen_address);
1905         return c;
1906 }
1907
1908 static Channel *
1909 client_request_forwarded_streamlocal(const char *request_type, int rchan)
1910 {
1911         Channel *c = NULL;
1912         char *listen_path;
1913
1914         /* Get the remote path. */
1915         listen_path = packet_get_string(NULL);
1916         /* XXX: Skip reserved field for now. */
1917         if (packet_get_string_ptr(NULL) == NULL)
1918                 fatal("%s: packet_get_string_ptr failed", __func__);
1919         packet_check_eom();
1920
1921         debug("%s: %s", __func__, listen_path);
1922
1923         c = channel_connect_by_listen_path(listen_path,
1924             "forwarded-streamlocal@openssh.com", "forwarded-streamlocal");
1925         free(listen_path);
1926         return c;
1927 }
1928
1929 static Channel *
1930 client_request_x11(const char *request_type, int rchan)
1931 {
1932         Channel *c = NULL;
1933         char *originator;
1934         u_short originator_port;
1935         int sock;
1936
1937         if (!options.forward_x11) {
1938                 error("Warning: ssh server tried X11 forwarding.");
1939                 error("Warning: this is probably a break-in attempt by a "
1940                     "malicious server.");
1941                 return NULL;
1942         }
1943         if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
1944                 verbose("Rejected X11 connection after ForwardX11Timeout "
1945                     "expired");
1946                 return NULL;
1947         }
1948         originator = packet_get_string(NULL);
1949         if (datafellows & SSH_BUG_X11FWD) {
1950                 debug2("buggy server: x11 request w/o originator_port");
1951                 originator_port = 0;
1952         } else {
1953                 originator_port = packet_get_int();
1954         }
1955         packet_check_eom();
1956         /* XXX check permission */
1957         debug("client_request_x11: request from %s %d", originator,
1958             originator_port);
1959         free(originator);
1960         sock = x11_connect_display();
1961         if (sock < 0)
1962                 return NULL;
1963         c = channel_new("x11",
1964             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1965             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1966         c->force_drain = 1;
1967         return c;
1968 }
1969
1970 static Channel *
1971 client_request_agent(const char *request_type, int rchan)
1972 {
1973         Channel *c = NULL;
1974         int r, sock;
1975
1976         if (!options.forward_agent) {
1977                 error("Warning: ssh server tried agent forwarding.");
1978                 error("Warning: this is probably a break-in attempt by a "
1979                     "malicious server.");
1980                 return NULL;
1981         }
1982         if ((r = ssh_get_authentication_socket(&sock)) != 0) {
1983                 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1984                         debug("%s: ssh_get_authentication_socket: %s",
1985                             __func__, ssh_err(r));
1986                 return NULL;
1987         }
1988         c = channel_new("authentication agent connection",
1989             SSH_CHANNEL_OPEN, sock, sock, -1,
1990             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1991             "authentication agent connection", 1);
1992         c->force_drain = 1;
1993         return c;
1994 }
1995
1996 int
1997 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1998 {
1999         Channel *c;
2000         int fd;
2001
2002         if (tun_mode == SSH_TUNMODE_NO)
2003                 return 0;
2004
2005         if (!compat20) {
2006                 error("Tunnel forwarding is not supported for protocol 1");
2007                 return -1;
2008         }
2009
2010         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
2011
2012         /* Open local tunnel device */
2013         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
2014                 error("Tunnel device open failed.");
2015                 return -1;
2016         }
2017
2018         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
2019             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
2020         c->datagram = 1;
2021
2022 #if defined(SSH_TUN_FILTER)
2023         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
2024                 channel_register_filter(c->self, sys_tun_infilter,
2025                     sys_tun_outfilter, NULL, NULL);
2026 #endif
2027
2028         packet_start(SSH2_MSG_CHANNEL_OPEN);
2029         packet_put_cstring("tun@openssh.com");
2030         packet_put_int(c->self);
2031         packet_put_int(c->local_window_max);
2032         packet_put_int(c->local_maxpacket);
2033         packet_put_int(tun_mode);
2034         packet_put_int(remote_tun);
2035         packet_send();
2036
2037         return 0;
2038 }
2039
2040 /* XXXX move to generic input handler */
2041 static int
2042 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
2043 {
2044         Channel *c = NULL;
2045         char *ctype;
2046         int rchan;
2047         u_int rmaxpack, rwindow, len;
2048
2049         ctype = packet_get_string(&len);
2050         rchan = packet_get_int();
2051         rwindow = packet_get_int();
2052         rmaxpack = packet_get_int();
2053
2054         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
2055             ctype, rchan, rwindow, rmaxpack);
2056
2057         if (strcmp(ctype, "forwarded-tcpip") == 0) {
2058                 c = client_request_forwarded_tcpip(ctype, rchan);
2059         } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) {
2060                 c = client_request_forwarded_streamlocal(ctype, rchan);
2061         } else if (strcmp(ctype, "x11") == 0) {
2062                 c = client_request_x11(ctype, rchan);
2063         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
2064                 c = client_request_agent(ctype, rchan);
2065         }
2066 /* XXX duplicate : */
2067         if (c != NULL) {
2068                 debug("confirm %s", ctype);
2069                 c->remote_id = rchan;
2070                 c->remote_window = rwindow;
2071                 c->remote_maxpacket = rmaxpack;
2072                 if (c->type != SSH_CHANNEL_CONNECTING) {
2073                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2074                         packet_put_int(c->remote_id);
2075                         packet_put_int(c->self);
2076                         packet_put_int(c->local_window);
2077                         packet_put_int(c->local_maxpacket);
2078                         packet_send();
2079                 }
2080         } else {
2081                 debug("failure %s", ctype);
2082                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2083                 packet_put_int(rchan);
2084                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
2085                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2086                         packet_put_cstring("open failed");
2087                         packet_put_cstring("");
2088                 }
2089                 packet_send();
2090         }
2091         free(ctype);
2092         return 0;
2093 }
2094
2095 static int
2096 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
2097 {
2098         Channel *c = NULL;
2099         int exitval, id, reply, success = 0;
2100         char *rtype;
2101
2102         id = packet_get_int();
2103         rtype = packet_get_string(NULL);
2104         reply = packet_get_char();
2105
2106         debug("client_input_channel_req: channel %d rtype %s reply %d",
2107             id, rtype, reply);
2108
2109         if (id == -1) {
2110                 error("client_input_channel_req: request for channel -1");
2111         } else if ((c = channel_lookup(id)) == NULL) {
2112                 error("client_input_channel_req: channel %d: "
2113                     "unknown channel", id);
2114         } else if (strcmp(rtype, "eow@openssh.com") == 0) {
2115                 packet_check_eom();
2116                 chan_rcvd_eow(c);
2117         } else if (strcmp(rtype, "exit-status") == 0) {
2118                 exitval = packet_get_int();
2119                 if (c->ctl_chan != -1) {
2120                         mux_exit_message(c, exitval);
2121                         success = 1;
2122                 } else if (id == session_ident) {
2123                         /* Record exit value of local session */
2124                         success = 1;
2125                         exit_status = exitval;
2126                 } else {
2127                         /* Probably for a mux channel that has already closed */
2128                         debug("%s: no sink for exit-status on channel %d",
2129                             __func__, id);
2130                 }
2131                 packet_check_eom();
2132         }
2133         if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) {
2134                 packet_start(success ?
2135                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
2136                 packet_put_int(c->remote_id);
2137                 packet_send();
2138         }
2139         free(rtype);
2140         return 0;
2141 }
2142
2143 struct hostkeys_update_ctx {
2144         /* The hostname and (optionally) IP address string for the server */
2145         char *host_str, *ip_str;
2146
2147         /*
2148          * Keys received from the server and a flag for each indicating
2149          * whether they already exist in known_hosts.
2150          * keys_seen is filled in by hostkeys_find() and later (for new
2151          * keys) by client_global_hostkeys_private_confirm().
2152          */
2153         struct sshkey **keys;
2154         int *keys_seen;
2155         size_t nkeys;
2156
2157         size_t nnew;
2158
2159         /*
2160          * Keys that are in known_hosts, but were not present in the update
2161          * from the server (i.e. scheduled to be deleted).
2162          * Filled in by hostkeys_find().
2163          */
2164         struct sshkey **old_keys;
2165         size_t nold;
2166 };
2167
2168 static void
2169 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx)
2170 {
2171         size_t i;
2172
2173         if (ctx == NULL)
2174                 return;
2175         for (i = 0; i < ctx->nkeys; i++)
2176                 sshkey_free(ctx->keys[i]);
2177         free(ctx->keys);
2178         free(ctx->keys_seen);
2179         for (i = 0; i < ctx->nold; i++)
2180                 sshkey_free(ctx->old_keys[i]);
2181         free(ctx->old_keys);
2182         free(ctx->host_str);
2183         free(ctx->ip_str);
2184         free(ctx);
2185 }
2186
2187 static int
2188 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
2189 {
2190         struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
2191         size_t i;
2192         struct sshkey **tmp;
2193
2194         if (l->status != HKF_STATUS_MATCHED || l->key == NULL ||
2195             l->key->type == KEY_RSA1)
2196                 return 0;
2197
2198         /* Mark off keys we've already seen for this host */
2199         for (i = 0; i < ctx->nkeys; i++) {
2200                 if (sshkey_equal(l->key, ctx->keys[i])) {
2201                         debug3("%s: found %s key at %s:%ld", __func__,
2202                             sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum);
2203                         ctx->keys_seen[i] = 1;
2204                         return 0;
2205                 }
2206         }
2207         /* This line contained a key that not offered by the server */
2208         debug3("%s: deprecated %s key at %s:%ld", __func__,
2209             sshkey_ssh_name(l->key), l->path, l->linenum);
2210         if ((tmp = reallocarray(ctx->old_keys, ctx->nold + 1,
2211             sizeof(*ctx->old_keys))) == NULL)
2212                 fatal("%s: reallocarray failed nold = %zu",
2213                     __func__, ctx->nold);
2214         ctx->old_keys = tmp;
2215         ctx->old_keys[ctx->nold++] = l->key;
2216         l->key = NULL;
2217
2218         return 0;
2219 }
2220
2221 static void
2222 update_known_hosts(struct hostkeys_update_ctx *ctx)
2223 {
2224         int r, was_raw = 0;
2225         int loglevel = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK ?
2226             SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE;
2227         char *fp, *response;
2228         size_t i;
2229
2230         for (i = 0; i < ctx->nkeys; i++) {
2231                 if (ctx->keys_seen[i] != 2)
2232                         continue;
2233                 if ((fp = sshkey_fingerprint(ctx->keys[i],
2234                     options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2235                         fatal("%s: sshkey_fingerprint failed", __func__);
2236                 do_log2(loglevel, "Learned new hostkey: %s %s",
2237                     sshkey_type(ctx->keys[i]), fp);
2238                 free(fp);
2239         }
2240         for (i = 0; i < ctx->nold; i++) {
2241                 if ((fp = sshkey_fingerprint(ctx->old_keys[i],
2242                     options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2243                         fatal("%s: sshkey_fingerprint failed", __func__);
2244                 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s",
2245                     sshkey_type(ctx->old_keys[i]), fp);
2246                 free(fp);
2247         }
2248         if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
2249                 if (get_saved_tio() != NULL) {
2250                         leave_raw_mode(1);
2251                         was_raw = 1;
2252                 }
2253                 response = NULL;
2254                 for (i = 0; !quit_pending && i < 3; i++) {
2255                         free(response);
2256                         response = read_passphrase("Accept updated hostkeys? "
2257                             "(yes/no): ", RP_ECHO);
2258                         if (strcasecmp(response, "yes") == 0)
2259                                 break;
2260                         else if (quit_pending || response == NULL ||
2261                             strcasecmp(response, "no") == 0) {
2262                                 options.update_hostkeys = 0;
2263                                 break;
2264                         } else {
2265                                 do_log2(loglevel, "Please enter "
2266                                     "\"yes\" or \"no\"");
2267                         }
2268                 }
2269                 if (quit_pending || i >= 3 || response == NULL)
2270                         options.update_hostkeys = 0;
2271                 free(response);
2272                 if (was_raw)
2273                         enter_raw_mode(1);
2274         }
2275
2276         /*
2277          * Now that all the keys are verified, we can go ahead and replace
2278          * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't
2279          * cancel the operation).
2280          */
2281         if (options.update_hostkeys != 0 &&
2282             (r = hostfile_replace_entries(options.user_hostfiles[0],
2283             ctx->host_str, ctx->ip_str, ctx->keys, ctx->nkeys,
2284             options.hash_known_hosts, 0,
2285             options.fingerprint_hash)) != 0)
2286                 error("%s: hostfile_replace_entries failed: %s",
2287                     __func__, ssh_err(r));
2288 }
2289
2290 static void
2291 client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx)
2292 {
2293         struct ssh *ssh = active_state; /* XXX */
2294         struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
2295         size_t i, ndone;
2296         struct sshbuf *signdata;
2297         int r;
2298         const u_char *sig;
2299         size_t siglen;
2300
2301         if (ctx->nnew == 0)
2302                 fatal("%s: ctx->nnew == 0", __func__); /* sanity */
2303         if (type != SSH2_MSG_REQUEST_SUCCESS) {
2304                 error("Server failed to confirm ownership of "
2305                     "private host keys");
2306                 hostkeys_update_ctx_free(ctx);
2307                 return;
2308         }
2309         if ((signdata = sshbuf_new()) == NULL)
2310                 fatal("%s: sshbuf_new failed", __func__);
2311         /* Don't want to accidentally accept an unbound signature */
2312         if (ssh->kex->session_id_len == 0)
2313                 fatal("%s: ssh->kex->session_id_len == 0", __func__);
2314         /*
2315          * Expect a signature for each of the ctx->nnew private keys we
2316          * haven't seen before. They will be in the same order as the
2317          * ctx->keys where the corresponding ctx->keys_seen[i] == 0.
2318          */
2319         for (ndone = i = 0; i < ctx->nkeys; i++) {
2320                 if (ctx->keys_seen[i])
2321                         continue;
2322                 /* Prepare data to be signed: session ID, unique string, key */
2323                 sshbuf_reset(signdata);
2324                 if ( (r = sshbuf_put_cstring(signdata,
2325                     "hostkeys-prove-00@openssh.com")) != 0 ||
2326                     (r = sshbuf_put_string(signdata, ssh->kex->session_id,
2327                     ssh->kex->session_id_len)) != 0 ||
2328                     (r = sshkey_puts(ctx->keys[i], signdata)) != 0)
2329                         fatal("%s: failed to prepare signature: %s",
2330                             __func__, ssh_err(r));
2331                 /* Extract and verify signature */
2332                 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) {
2333                         error("%s: couldn't parse message: %s",
2334                             __func__, ssh_err(r));
2335                         goto out;
2336                 }
2337                 if ((r = sshkey_verify(ctx->keys[i], sig, siglen,
2338                     sshbuf_ptr(signdata), sshbuf_len(signdata), 0)) != 0) {
2339                         error("%s: server gave bad signature for %s key %zu",
2340                             __func__, sshkey_type(ctx->keys[i]), i);
2341                         goto out;
2342                 }
2343                 /* Key is good. Mark it as 'seen' */
2344                 ctx->keys_seen[i] = 2;
2345                 ndone++;
2346         }
2347         if (ndone != ctx->nnew)
2348                 fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__,
2349                     ndone, ctx->nnew);  /* Shouldn't happen */
2350         ssh_packet_check_eom(ssh);
2351
2352         /* Make the edits to known_hosts */
2353         update_known_hosts(ctx);
2354  out:
2355         hostkeys_update_ctx_free(ctx);
2356 }
2357
2358 /*
2359  * Handle hostkeys-00@openssh.com global request to inform the client of all
2360  * the server's hostkeys. The keys are checked against the user's
2361  * HostkeyAlgorithms preference before they are accepted.
2362  */
2363 static int
2364 client_input_hostkeys(void)
2365 {
2366         struct ssh *ssh = active_state; /* XXX */
2367         const u_char *blob = NULL;
2368         size_t i, len = 0;
2369         struct sshbuf *buf = NULL;
2370         struct sshkey *key = NULL, **tmp;
2371         int r;
2372         char *fp;
2373         static int hostkeys_seen = 0; /* XXX use struct ssh */
2374         extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */
2375         struct hostkeys_update_ctx *ctx = NULL;
2376
2377         if (hostkeys_seen)
2378                 fatal("%s: server already sent hostkeys", __func__);
2379         if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK &&
2380             options.batch_mode)
2381                 return 1; /* won't ask in batchmode, so don't even try */
2382         if (!options.update_hostkeys || options.num_user_hostfiles <= 0)
2383                 return 1;
2384
2385         ctx = xcalloc(1, sizeof(*ctx));
2386         while (ssh_packet_remaining(ssh) > 0) {
2387                 sshkey_free(key);
2388                 key = NULL;
2389                 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) {
2390                         error("%s: couldn't parse message: %s",
2391                             __func__, ssh_err(r));
2392                         goto out;
2393                 }
2394                 if ((r = sshkey_from_blob(blob, len, &key)) != 0) {
2395                         error("%s: parse key: %s", __func__, ssh_err(r));
2396                         goto out;
2397                 }
2398                 fp = sshkey_fingerprint(key, options.fingerprint_hash,
2399                     SSH_FP_DEFAULT);
2400                 debug3("%s: received %s key %s", __func__,
2401                     sshkey_type(key), fp);
2402                 free(fp);
2403
2404                 /* Check that the key is accepted in HostkeyAlgorithms */
2405                 if (match_pattern_list(sshkey_ssh_name(key),
2406                     options.hostkeyalgorithms ? options.hostkeyalgorithms :
2407                     KEX_DEFAULT_PK_ALG, 0) != 1) {
2408                         debug3("%s: %s key not permitted by HostkeyAlgorithms",
2409                             __func__, sshkey_ssh_name(key));
2410                         continue;
2411                 }
2412                 /* Skip certs */
2413                 if (sshkey_is_cert(key)) {
2414                         debug3("%s: %s key is a certificate; skipping",
2415                             __func__, sshkey_ssh_name(key));
2416                         continue;
2417                 }
2418                 /* Ensure keys are unique */
2419                 for (i = 0; i < ctx->nkeys; i++) {
2420                         if (sshkey_equal(key, ctx->keys[i])) {
2421                                 error("%s: received duplicated %s host key",
2422                                     __func__, sshkey_ssh_name(key));
2423                                 goto out;
2424                         }
2425                 }
2426                 /* Key is good, record it */
2427                 if ((tmp = reallocarray(ctx->keys, ctx->nkeys + 1,
2428                     sizeof(*ctx->keys))) == NULL)
2429                         fatal("%s: reallocarray failed nkeys = %zu",
2430                             __func__, ctx->nkeys);
2431                 ctx->keys = tmp;
2432                 ctx->keys[ctx->nkeys++] = key;
2433                 key = NULL;
2434         }
2435
2436         if (ctx->nkeys == 0) {
2437                 debug("%s: server sent no hostkeys", __func__);
2438                 goto out;
2439         }
2440
2441         if ((ctx->keys_seen = calloc(ctx->nkeys,
2442             sizeof(*ctx->keys_seen))) == NULL)
2443                 fatal("%s: calloc failed", __func__);
2444
2445         get_hostfile_hostname_ipaddr(host,
2446             options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL,
2447             options.port, &ctx->host_str,
2448             options.check_host_ip ? &ctx->ip_str : NULL);
2449
2450         /* Find which keys we already know about. */
2451         if ((r = hostkeys_foreach(options.user_hostfiles[0], hostkeys_find,
2452             ctx, ctx->host_str, ctx->ip_str,
2453             HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) {
2454                 error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
2455                 goto out;
2456         }
2457
2458         /* Figure out if we have any new keys to add */
2459         ctx->nnew = 0;
2460         for (i = 0; i < ctx->nkeys; i++) {
2461                 if (!ctx->keys_seen[i])
2462                         ctx->nnew++;
2463         }
2464
2465         debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove",
2466             __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold);
2467
2468         if (ctx->nnew == 0 && ctx->nold != 0) {
2469                 /* We have some keys to remove. Just do it. */
2470                 update_known_hosts(ctx);
2471         } else if (ctx->nnew != 0) {
2472                 /*
2473                  * We have received hitherto-unseen keys from the server.
2474                  * Ask the server to confirm ownership of the private halves.
2475                  */
2476                 debug3("%s: asking server to prove ownership for %zu keys",
2477                     __func__, ctx->nnew);
2478                 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2479                     (r = sshpkt_put_cstring(ssh,
2480                     "hostkeys-prove-00@openssh.com")) != 0 ||
2481                     (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */
2482                         fatal("%s: cannot prepare packet: %s",
2483                             __func__, ssh_err(r));
2484                 if ((buf = sshbuf_new()) == NULL)
2485                         fatal("%s: sshbuf_new", __func__);
2486                 for (i = 0; i < ctx->nkeys; i++) {
2487                         if (ctx->keys_seen[i])
2488                                 continue;
2489                         sshbuf_reset(buf);
2490                         if ((r = sshkey_putb(ctx->keys[i], buf)) != 0)
2491                                 fatal("%s: sshkey_putb: %s",
2492                                     __func__, ssh_err(r));
2493                         if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
2494                                 fatal("%s: sshpkt_put_string: %s",
2495                                     __func__, ssh_err(r));
2496                 }
2497                 if ((r = sshpkt_send(ssh)) != 0)
2498                         fatal("%s: sshpkt_send: %s", __func__, ssh_err(r));
2499                 client_register_global_confirm(
2500                     client_global_hostkeys_private_confirm, ctx);
2501                 ctx = NULL;  /* will be freed in callback */
2502         }
2503
2504         /* Success */
2505  out:
2506         hostkeys_update_ctx_free(ctx);
2507         sshkey_free(key);
2508         sshbuf_free(buf);
2509         /*
2510          * NB. Return success for all cases. The server doesn't need to know
2511          * what the client does with its hosts file.
2512          */
2513         return 1;
2514 }
2515
2516 static int
2517 client_input_global_request(int type, u_int32_t seq, void *ctxt)
2518 {
2519         char *rtype;
2520         int want_reply;
2521         int success = 0;
2522
2523         rtype = packet_get_cstring(NULL);
2524         want_reply = packet_get_char();
2525         debug("client_input_global_request: rtype %s want_reply %d",
2526             rtype, want_reply);
2527         if (strcmp(rtype, "hostkeys-00@openssh.com") == 0)
2528                 success = client_input_hostkeys();
2529         if (want_reply) {
2530                 packet_start(success ?
2531                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
2532                 packet_send();
2533                 packet_write_wait();
2534         }
2535         free(rtype);
2536         return 0;
2537 }
2538
2539 void
2540 client_session2_setup(int id, int want_tty, int want_subsystem,
2541     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
2542 {
2543         int len;
2544         Channel *c = NULL;
2545
2546         debug2("%s: id %d", __func__, id);
2547
2548         if ((c = channel_lookup(id)) == NULL)
2549                 fatal("client_session2_setup: channel %d: unknown channel", id);
2550
2551         packet_set_interactive(want_tty,
2552             options.ip_qos_interactive, options.ip_qos_bulk);
2553
2554         if (want_tty) {
2555                 struct winsize ws;
2556
2557                 /* Store window size in the packet. */
2558                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
2559                         memset(&ws, 0, sizeof(ws));
2560
2561                 channel_request_start(id, "pty-req", 1);
2562                 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY);
2563                 packet_put_cstring(term != NULL ? term : "");
2564                 packet_put_int((u_int)ws.ws_col);
2565                 packet_put_int((u_int)ws.ws_row);
2566                 packet_put_int((u_int)ws.ws_xpixel);
2567                 packet_put_int((u_int)ws.ws_ypixel);
2568                 if (tiop == NULL)
2569                         tiop = get_saved_tio();
2570                 tty_make_modes(-1, tiop);
2571                 packet_send();
2572                 /* XXX wait for reply */
2573                 c->client_tty = 1;
2574         }
2575
2576         /* Transfer any environment variables from client to server */
2577         if (options.num_send_env != 0 && env != NULL) {
2578                 int i, j, matched;
2579                 char *name, *val;
2580
2581                 debug("Sending environment.");
2582                 for (i = 0; env[i] != NULL; i++) {
2583                         /* Split */
2584                         name = xstrdup(env[i]);
2585                         if ((val = strchr(name, '=')) == NULL) {
2586                                 free(name);
2587                                 continue;
2588                         }
2589                         *val++ = '\0';
2590
2591                         matched = 0;
2592                         for (j = 0; j < options.num_send_env; j++) {
2593                                 if (match_pattern(name, options.send_env[j])) {
2594                                         matched = 1;
2595                                         break;
2596                                 }
2597                         }
2598                         if (!matched) {
2599                                 debug3("Ignored env %s", name);
2600                                 free(name);
2601                                 continue;
2602                         }
2603
2604                         debug("Sending env %s = %s", name, val);
2605                         channel_request_start(id, "env", 0);
2606                         packet_put_cstring(name);
2607                         packet_put_cstring(val);
2608                         packet_send();
2609                         free(name);
2610                 }
2611         }
2612
2613         len = buffer_len(cmd);
2614         if (len > 0) {
2615                 if (len > 900)
2616                         len = 900;
2617                 if (want_subsystem) {
2618                         debug("Sending subsystem: %.*s",
2619                             len, (u_char*)buffer_ptr(cmd));
2620                         channel_request_start(id, "subsystem", 1);
2621                         client_expect_confirm(id, "subsystem", CONFIRM_CLOSE);
2622                 } else {
2623                         debug("Sending command: %.*s",
2624                             len, (u_char*)buffer_ptr(cmd));
2625                         channel_request_start(id, "exec", 1);
2626                         client_expect_confirm(id, "exec", CONFIRM_CLOSE);
2627                 }
2628                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2629                 packet_send();
2630         } else {
2631                 channel_request_start(id, "shell", 1);
2632                 client_expect_confirm(id, "shell", CONFIRM_CLOSE);
2633                 packet_send();
2634         }
2635 }
2636
2637 static void
2638 client_init_dispatch_20(void)
2639 {
2640         dispatch_init(&dispatch_protocol_error);
2641
2642         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2643         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2644         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2645         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2646         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2647         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2648         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2649         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2650         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2651         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2652         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2653         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2654
2655         /* rekeying */
2656         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2657
2658         /* global request reply messages */
2659         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2660         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2661 }
2662
2663 static void
2664 client_init_dispatch_13(void)
2665 {
2666         dispatch_init(NULL);
2667         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2668         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2669         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2670         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2671         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2672         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2673         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2674         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2675         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2676
2677         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2678             &client_input_agent_open : &deny_input_open);
2679         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2680             &x11_input_open : &deny_input_open);
2681 }
2682
2683 static void
2684 client_init_dispatch_15(void)
2685 {
2686         client_init_dispatch_13();
2687         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2688         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2689 }
2690
2691 static void
2692 client_init_dispatch(void)
2693 {
2694         if (compat20)
2695                 client_init_dispatch_20();
2696         else if (compat13)
2697                 client_init_dispatch_13();
2698         else
2699                 client_init_dispatch_15();
2700 }
2701
2702 void
2703 client_stop_mux(void)
2704 {
2705         if (options.control_path != NULL && muxserver_sock != -1)
2706                 unlink(options.control_path);
2707         /*
2708          * If we are in persist mode, or don't have a shell, signal that we
2709          * should close when all active channels are closed.
2710          */
2711         if (options.control_persist || no_shell_flag) {
2712                 session_closed = 1;
2713                 setproctitle("[stopped mux]");
2714         }
2715 }
2716
2717 /* client specific fatal cleanup */
2718 void
2719 cleanup_exit(int i)
2720 {
2721         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2722         leave_non_blocking();
2723         if (options.control_path != NULL && muxserver_sock != -1)
2724                 unlink(options.control_path);
2725         ssh_kill_proxy_command();
2726         _exit(i);
2727 }