crypto/openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.240 2012/06/20 04:42:58 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * The main loop for the interactive session (client side).
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  *
  15  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  *
  38  * SSH2 support added by Markus Friedl.
  39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #include "includes.h"
  63
  64 #include <sys/types.h>
  65 #include <sys/ioctl.h>
  66 #include <sys/param.h>
  67 #ifdef HAVE_SYS_STAT_H
  68 # include <sys/stat.h>
  69 #endif
  70 #ifdef HAVE_SYS_TIME_H
  71 # include <sys/time.h>
  72 #endif
  73 #include <sys/socket.h>
  74
  75 #include <ctype.h>
  76 #include <errno.h>
  77 #ifdef HAVE_PATHS_H
  78 #include <paths.h>
  79 #endif
  80 #include <signal.h>
  81 #include <stdarg.h>
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <string.h>
  85 #include <termios.h>
  86 #include <pwd.h>
  87 #include <unistd.h>
  88
  89 #include "openbsd-compat/sys-queue.h"
  90 #include "xmalloc.h"
  91 #include "ssh.h"
  92 #include "ssh1.h"
  93 #include "ssh2.h"
  94 #include "packet.h"
  95 #include "buffer.h"
  96 #include "compat.h"
  97 #include "channels.h"
  98 #include "dispatch.h"
  99 #include "key.h"
 100 #include "cipher.h"
 101 #include "kex.h"
 102 #include "log.h"
 103 #include "readconf.h"
 104 #include "clientloop.h"
 105 #include "sshconnect.h"
 106 #include "authfd.h"
 107 #include "atomicio.h"
 108 #include "sshpty.h"
 109 #include "misc.h"
 110 #include "match.h"
 111 #include "msg.h"
 112 #include "roaming.h"
 113
 114 /* import options */
 115 extern Options options;
 116
 117 /* Flag indicating that stdin should be redirected from /dev/null. */
 118 extern int stdin_null_flag;
 119
 120 /* Flag indicating that no shell has been requested */
 121 extern int no_shell_flag;
 122
 123 /* Control socket */
 124 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
 125
 126 /*
 127  * Name of the host we are connecting to.  This is the name given on the
 128  * command line, or the HostName specified for the user-supplied name in a
 129  * configuration file.
 130  */
 131 extern char *host;
 132
 133 /*
 134  * Flag to indicate that we have received a window change signal which has
 135  * not yet been processed.  This will cause a message indicating the new
 136  * window size to be sent to the server a little later.  This is volatile
 137  * because this is updated in a signal handler.
 138  */
 139 static volatile sig_atomic_t received_window_change_signal = 0;
 140 static volatile sig_atomic_t received_signal = 0;
 141
 142 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 143 static int in_non_blocking_mode = 0;
 144
 145 /* Time when backgrounded control master using ControlPersist should exit */
 146 static time_t control_persist_exit_time = 0;
 147
 148 /* Common data for the client loop code. */
 149 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 150 static int escape_char1;        /* Escape character. (proto1 only) */
 151 static int escape_pending1;     /* Last character was an escape (proto1 only) */
 152 static int last_was_cr;         /* Last character was a newline. */
 153 static int exit_status;         /* Used to store the command exit status. */
 154 static int stdin_eof;           /* EOF has been encountered on stderr. */
 155 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 156 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 157 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 158 static u_int buffer_high;       /* Soft max buffer size. */
 159 static int connection_in;       /* Connection to server (input). */
 160 static int connection_out;      /* Connection to server (output). */
 161 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 162 static int session_closed;      /* In SSH2: login session closed. */
 163 static int x11_refuse_time;     /* If >0, refuse x11 opens after this time. */
 164
 165 static void client_init_dispatch(void);
 166 int     session_ident = -1;
 167
 168 int     session_resumed = 0;
 169
 170 /* Track escape per proto2 channel */
 171 struct escape_filter_ctx {
 172         int escape_pending;
 173         int escape_char;
 174 };
 175
 176 /* Context for channel confirmation replies */
 177 struct channel_reply_ctx {
 178         const char *request_type;
 179         int id;
 180         enum confirm_action action;
 181 };
 182
 183 /* Global request success/failure callbacks */
 184 struct global_confirm {
 185         TAILQ_ENTRY(global_confirm) entry;
 186         global_confirm_cb *cb;
 187         void *ctx;
 188         int ref_count;
 189 };
 190 TAILQ_HEAD(global_confirms, global_confirm);
 191 static struct global_confirms global_confirms =
 192     TAILQ_HEAD_INITIALIZER(global_confirms);
 193
 194 /*XXX*/
 195 extern Kex *xxx_kex;
 196
 197 void ssh_process_session2_setup(int, int, int, Buffer *);
 198
 199 /* Restores stdin to blocking mode. */
 200
 201 static void
 202 leave_non_blocking(void)
 203 {
 204         if (in_non_blocking_mode) {
 205                 unset_nonblock(fileno(stdin));
 206                 in_non_blocking_mode = 0;
 207         }
 208 }
 209
 210 /* Puts stdin terminal in non-blocking mode. */
 211
 212 static void
 213 enter_non_blocking(void)
 214 {
 215         in_non_blocking_mode = 1;
 216         set_nonblock(fileno(stdin));
 217 }
 218
 219 /*
 220  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 221  * flag indicating that the window has changed.
 222  */
 223 /*ARGSUSED */
 224 static void
 225 window_change_handler(int sig)
 226 {
 227         received_window_change_signal = 1;
 228         signal(SIGWINCH, window_change_handler);
 229 }
 230
 231 /*
 232  * Signal handler for signals that cause the program to terminate.  These
 233  * signals must be trapped to restore terminal modes.
 234  */
 235 /*ARGSUSED */
 236 static void
 237 signal_handler(int sig)
 238 {
 239         received_signal = sig;
 240         quit_pending = 1;
 241 }
 242
 243 /*
 244  * Returns current time in seconds from Jan 1, 1970 with the maximum
 245  * available resolution.
 246  */
 247
 248 static double
 249 get_current_time(void)
 250 {
 251         struct timeval tv;
 252         gettimeofday(&tv, NULL);
 253         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 254 }
 255
 256 /*
 257  * Sets control_persist_exit_time to the absolute time when the
 258  * backgrounded control master should exit due to expiry of the
 259  * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
 260  * control master process, or if there is no ControlPersist timeout.
 261  */
 262 static void
 263 set_control_persist_exit_time(void)
 264 {
 265         if (muxserver_sock == -1 || !options.control_persist
 266             || options.control_persist_timeout == 0) {
 267                 /* not using a ControlPersist timeout */
 268                 control_persist_exit_time = 0;
 269         } else if (channel_still_open()) {
 270                 /* some client connections are still open */
 271                 if (control_persist_exit_time > 0)
 272                         debug2("%s: cancel scheduled exit", __func__);
 273                 control_persist_exit_time = 0;
 274         } else if (control_persist_exit_time <= 0) {
 275                 /* a client connection has recently closed */
 276                 control_persist_exit_time = time(NULL) +
 277                         (time_t)options.control_persist_timeout;
 278                 debug2("%s: schedule exit in %d seconds", __func__,
 279                     options.control_persist_timeout);
 280         }
 281         /* else we are already counting down to the timeout */
 282 }
 283
 284 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_"
 285 static int
 286 client_x11_display_valid(const char *display)
 287 {
 288         size_t i, dlen;
 289
 290         dlen = strlen(display);
 291         for (i = 0; i < dlen; i++) {
 292                 if (!isalnum(display[i]) &&
 293                     strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) {
 294                         debug("Invalid character '%c' in DISPLAY", display[i]);
 295                         return 0;
 296                 }
 297         }
 298         return 1;
 299 }
 300
 301 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 302 void
 303 client_x11_get_proto(const char *display, const char *xauth_path,
 304     u_int trusted, u_int timeout, char **_proto, char **_data)
 305 {
 306         char cmd[1024];
 307         char line[512];
 308         char xdisplay[512];
 309         static char proto[512], data[512];
 310         FILE *f;
 311         int got_data = 0, generated = 0, do_unlink = 0, i;
 312         char *xauthdir, *xauthfile;
 313         struct stat st;
 314         u_int now;
 315
 316         xauthdir = xauthfile = NULL;
 317         *_proto = proto;
 318         *_data = data;
 319         proto[0] = data[0] = '\0';
 320
 321         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 322                 debug("No xauth program.");
 323         } else if (!client_x11_display_valid(display)) {
 324                 logit("DISPLAY '%s' invalid, falling back to fake xauth data",
 325                     display);
 326         } else {
 327                 if (display == NULL) {
 328                         debug("x11_get_proto: DISPLAY not set");
 329                         return;
 330                 }
 331                 /*
 332                  * Handle FamilyLocal case where $DISPLAY does
 333                  * not match an authorization entry.  For this we
 334                  * just try "xauth list unix:displaynum.screennum".
 335                  * XXX: "localhost" match to determine FamilyLocal
 336                  *      is not perfect.
 337                  */
 338                 if (strncmp(display, "localhost:", 10) == 0) {
 339                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 340                             display + 10);
 341                         display = xdisplay;
 342                 }
 343                 if (trusted == 0) {
 344                         xauthdir = xmalloc(MAXPATHLEN);
 345                         xauthfile = xmalloc(MAXPATHLEN);
 346                         mktemp_proto(xauthdir, MAXPATHLEN);
 347                         if (mkdtemp(xauthdir) != NULL) {
 348                                 do_unlink = 1;
 349                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 350                                     xauthdir);
 351                                 snprintf(cmd, sizeof(cmd),
 352                                     "%s -f %s generate %s " SSH_X11_PROTO
 353                                     " untrusted timeout %u 2>" _PATH_DEVNULL,
 354                                     xauth_path, xauthfile, display, timeout);
 355                                 debug2("x11_get_proto: %s", cmd);
 356                                 if (system(cmd) == 0)
 357                                         generated = 1;
 358                                 if (x11_refuse_time == 0) {
 359                                         now = time(NULL) + 1;
 360                                         if (UINT_MAX - timeout < now)
 361                                                 x11_refuse_time = UINT_MAX;
 362                                         else
 363                                                 x11_refuse_time = now + timeout;
 364                                 }
 365                         }
 366                 }
 367
 368                 /*
 369                  * When in untrusted mode, we read the cookie only if it was
 370                  * successfully generated as an untrusted one in the step
 371                  * above.
 372                  */
 373                 if (trusted || generated) {
 374                         snprintf(cmd, sizeof(cmd),
 375                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 376                             xauth_path,
 377                             generated ? "-f " : "" ,
 378                             generated ? xauthfile : "",
 379                             display);
 380                         debug2("x11_get_proto: %s", cmd);
 381                         f = popen(cmd, "r");
 382                         if (f && fgets(line, sizeof(line), f) &&
 383                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 384                                 got_data = 1;
 385                         if (f)
 386                                 pclose(f);
 387                 } else
 388                         error("Warning: untrusted X11 forwarding setup failed: "
 389                             "xauth key data not generated");
 390         }
 391
 392         if (do_unlink) {
 393                 unlink(xauthfile);
 394                 rmdir(xauthdir);
 395         }
 396         if (xauthdir)
 397                 xfree(xauthdir);
 398         if (xauthfile)
 399                 xfree(xauthfile);
 400
 401         /*
 402          * If we didn't get authentication data, just make up some
 403          * data.  The forwarding code will check the validity of the
 404          * response anyway, and substitute this data.  The X11
 405          * server, however, will ignore this fake data and use
 406          * whatever authentication mechanisms it was using otherwise
 407          * for the local connection.
 408          */
 409         if (!got_data) {
 410                 u_int32_t rnd = 0;
 411
 412                 logit("Warning: No xauth data; "
 413                     "using fake authentication data for X11 forwarding.");
 414                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 415                 for (i = 0; i < 16; i++) {
 416                         if (i % 4 == 0)
 417                                 rnd = arc4random();
 418                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 419                             rnd & 0xff);
 420                         rnd >>= 8;
 421                 }
 422         }
 423 }
 424
 425 /*
 426  * This is called when the interactive is entered.  This checks if there is
 427  * an EOF coming on stdin.  We must check this explicitly, as select() does
 428  * not appear to wake up when redirecting from /dev/null.
 429  */
 430
 431 static void
 432 client_check_initial_eof_on_stdin(void)
 433 {
 434         int len;
 435         char buf[1];
 436
 437         /*
 438          * If standard input is to be "redirected from /dev/null", we simply
 439          * mark that we have seen an EOF and send an EOF message to the
 440          * server. Otherwise, we try to read a single character; it appears
 441          * that for some files, such /dev/null, select() never wakes up for
 442          * read for this descriptor, which means that we never get EOF.  This
 443          * way we will get the EOF if stdin comes from /dev/null or similar.
 444          */
 445         if (stdin_null_flag) {
 446                 /* Fake EOF on stdin. */
 447                 debug("Sending eof.");
 448                 stdin_eof = 1;
 449                 packet_start(SSH_CMSG_EOF);
 450                 packet_send();
 451         } else {
 452                 enter_non_blocking();
 453
 454                 /* Check for immediate EOF on stdin. */
 455                 len = read(fileno(stdin), buf, 1);
 456                 if (len == 0) {
 457                         /*
 458                          * EOF.  Record that we have seen it and send
 459                          * EOF to server.
 460                          */
 461                         debug("Sending eof.");
 462                         stdin_eof = 1;
 463                         packet_start(SSH_CMSG_EOF);
 464                         packet_send();
 465                 } else if (len > 0) {
 466                         /*
 467                          * Got data.  We must store the data in the buffer,
 468                          * and also process it as an escape character if
 469                          * appropriate.
 470                          */
 471                         if ((u_char) buf[0] == escape_char1)
 472                                 escape_pending1 = 1;
 473                         else
 474                                 buffer_append(&stdin_buffer, buf, 1);
 475                 }
 476                 leave_non_blocking();
 477         }
 478 }
 479
 480
 481 /*
 482  * Make packets from buffered stdin data, and buffer them for sending to the
 483  * connection.
 484  */
 485
 486 static void
 487 client_make_packets_from_stdin_data(void)
 488 {
 489         u_int len;
 490
 491         /* Send buffered stdin data to the server. */
 492         while (buffer_len(&stdin_buffer) > 0 &&
 493             packet_not_very_much_data_to_write()) {
 494                 len = buffer_len(&stdin_buffer);
 495                 /* Keep the packets at reasonable size. */
 496                 if (len > packet_get_maxsize())
 497                         len = packet_get_maxsize();
 498                 packet_start(SSH_CMSG_STDIN_DATA);
 499                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 500                 packet_send();
 501                 buffer_consume(&stdin_buffer, len);
 502                 /* If we have a pending EOF, send it now. */
 503                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 504                         packet_start(SSH_CMSG_EOF);
 505                         packet_send();
 506                 }
 507         }
 508 }
 509
 510 /*
 511  * Checks if the client window has changed, and sends a packet about it to
 512  * the server if so.  The actual change is detected elsewhere (by a software
 513  * interrupt on Unix); this just checks the flag and sends a message if
 514  * appropriate.
 515  */
 516
 517 static void
 518 client_check_window_change(void)
 519 {
 520         struct winsize ws;
 521
 522         if (! received_window_change_signal)
 523                 return;
 524         /** XXX race */
 525         received_window_change_signal = 0;
 526
 527         debug2("client_check_window_change: changed");
 528
 529         if (compat20) {
 530                 channel_send_window_changes();
 531         } else {
 532                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 533                         return;
 534                 packet_start(SSH_CMSG_WINDOW_SIZE);
 535                 packet_put_int((u_int)ws.ws_row);
 536                 packet_put_int((u_int)ws.ws_col);
 537                 packet_put_int((u_int)ws.ws_xpixel);
 538                 packet_put_int((u_int)ws.ws_ypixel);
 539                 packet_send();
 540         }
 541 }
 542
 543 static void
 544 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 545 {
 546         struct global_confirm *gc;
 547
 548         if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
 549                 return;
 550         if (gc->cb != NULL)
 551                 gc->cb(type, seq, gc->ctx);
 552         if (--gc->ref_count <= 0) {
 553                 TAILQ_REMOVE(&global_confirms, gc, entry);
 554                 bzero(gc, sizeof(*gc));
 555                 xfree(gc);
 556         }
 557
 558         packet_set_alive_timeouts(0);
 559 }
 560
 561 static void
 562 server_alive_check(void)
 563 {
 564         if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
 565                 logit("Timeout, server %s not responding.", host);
 566                 cleanup_exit(255);
 567         }
 568         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 569         packet_put_cstring("keepalive@openssh.com");
 570         packet_put_char(1);     /* boolean: want reply */
 571         packet_send();
 572         /* Insert an empty placeholder to maintain ordering */
 573         client_register_global_confirm(NULL, NULL);
 574 }
 575
 576 /*
 577  * Waits until the client can do something (some data becomes available on
 578  * one of the file descriptors).
 579  */
 580 static void
 581 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 582     int *maxfdp, u_int *nallocp, int rekeying)
 583 {
 584         struct timeval tv, *tvp;
 585         int timeout_secs;
 586         time_t minwait_secs = 0;
 587         int ret;
 588
 589         /* Add any selections by the channel mechanism. */
 590         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
 591             &minwait_secs, rekeying);
 592
 593         if (!compat20) {
 594                 /* Read from the connection, unless our buffers are full. */
 595                 if (buffer_len(&stdout_buffer) < buffer_high &&
 596                     buffer_len(&stderr_buffer) < buffer_high &&
 597                     channel_not_very_much_buffered_data())
 598                         FD_SET(connection_in, *readsetp);
 599                 /*
 600                  * Read from stdin, unless we have seen EOF or have very much
 601                  * buffered data to send to the server.
 602                  */
 603                 if (!stdin_eof && packet_not_very_much_data_to_write())
 604                         FD_SET(fileno(stdin), *readsetp);
 605
 606                 /* Select stdout/stderr if have data in buffer. */
 607                 if (buffer_len(&stdout_buffer) > 0)
 608                         FD_SET(fileno(stdout), *writesetp);
 609                 if (buffer_len(&stderr_buffer) > 0)
 610                         FD_SET(fileno(stderr), *writesetp);
 611         } else {
 612                 /* channel_prepare_select could have closed the last channel */
 613                 if (session_closed && !channel_still_open() &&
 614                     !packet_have_data_to_write()) {
 615                         /* clear mask since we did not call select() */
 616                         memset(*readsetp, 0, *nallocp);
 617                         memset(*writesetp, 0, *nallocp);
 618                         return;
 619                 } else {
 620                         FD_SET(connection_in, *readsetp);
 621                 }
 622         }
 623
 624         /* Select server connection if have data to write to the server. */
 625         if (packet_have_data_to_write())
 626                 FD_SET(connection_out, *writesetp);
 627
 628         /*
 629          * Wait for something to happen.  This will suspend the process until
 630          * some selected descriptor can be read, written, or has some other
 631          * event pending, or a timeout expires.
 632          */
 633
 634         timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
 635         if (options.server_alive_interval > 0 && compat20)
 636                 timeout_secs = options.server_alive_interval;
 637         set_control_persist_exit_time();
 638         if (control_persist_exit_time > 0) {
 639                 timeout_secs = MIN(timeout_secs,
 640                         control_persist_exit_time - time(NULL));
 641                 if (timeout_secs < 0)
 642                         timeout_secs = 0;
 643         }
 644         if (minwait_secs != 0)
 645                 timeout_secs = MIN(timeout_secs, (int)minwait_secs);
 646         if (timeout_secs == INT_MAX)
 647                 tvp = NULL;
 648         else {
 649                 tv.tv_sec = timeout_secs;
 650                 tv.tv_usec = 0;
 651                 tvp = &tv;
 652         }
 653
 654         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 655         if (ret < 0) {
 656                 char buf[100];
 657
 658                 /*
 659                  * We have to clear the select masks, because we return.
 660                  * We have to return, because the mainloop checks for the flags
 661                  * set by the signal handlers.
 662                  */
 663                 memset(*readsetp, 0, *nallocp);
 664                 memset(*writesetp, 0, *nallocp);
 665
 666                 if (errno == EINTR)
 667                         return;
 668                 /* Note: we might still have data in the buffers. */
 669                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 670                 buffer_append(&stderr_buffer, buf, strlen(buf));
 671                 quit_pending = 1;
 672         } else if (ret == 0)
 673                 server_alive_check();
 674 }
 675
 676 static void
 677 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 678 {
 679         /* Flush stdout and stderr buffers. */
 680         if (buffer_len(bout) > 0)
 681                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
 682                     buffer_len(bout));
 683         if (buffer_len(berr) > 0)
 684                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
 685                     buffer_len(berr));
 686
 687         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 688
 689         /*
 690          * Free (and clear) the buffer to reduce the amount of data that gets
 691          * written to swap.
 692          */
 693         buffer_free(bin);
 694         buffer_free(bout);
 695         buffer_free(berr);
 696
 697         /* Send the suspend signal to the program itself. */
 698         kill(getpid(), SIGTSTP);
 699
 700         /* Reset window sizes in case they have changed */
 701         received_window_change_signal = 1;
 702
 703         /* OK, we have been continued by the user. Reinitialize buffers. */
 704         buffer_init(bin);
 705         buffer_init(bout);
 706         buffer_init(berr);
 707
 708         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 709 }
 710
 711 static void
 712 client_process_net_input(fd_set *readset)
 713 {
 714         int len, cont = 0;
 715         char buf[SSH_IOBUFSZ];
 716
 717         /*
 718          * Read input from the server, and add any such data to the buffer of
 719          * the packet subsystem.
 720          */
 721         if (FD_ISSET(connection_in, readset)) {
 722                 /* Read as much as possible. */
 723                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 724                 if (len == 0 && cont == 0) {
 725                         /*
 726                          * Received EOF.  The remote host has closed the
 727                          * connection.
 728                          */
 729                         snprintf(buf, sizeof buf,
 730                             "Connection to %.300s closed by remote host.\r\n",
 731                             host);
 732                         buffer_append(&stderr_buffer, buf, strlen(buf));
 733                         quit_pending = 1;
 734                         return;
 735                 }
 736                 /*
 737                  * There is a kernel bug on Solaris that causes select to
 738                  * sometimes wake up even though there is no data available.
 739                  */
 740                 if (len < 0 &&
 741                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 742                         len = 0;
 743
 744                 if (len < 0) {
 745                         /*
 746                          * An error has encountered.  Perhaps there is a
 747                          * network problem.
 748                          */
 749                         snprintf(buf, sizeof buf,
 750                             "Read from remote host %.300s: %.100s\r\n",
 751                             host, strerror(errno));
 752                         buffer_append(&stderr_buffer, buf, strlen(buf));
 753                         quit_pending = 1;
 754                         return;
 755                 }
 756                 packet_process_incoming(buf, len);
 757         }
 758 }
 759
 760 static void
 761 client_status_confirm(int type, Channel *c, void *ctx)
 762 {
 763         struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
 764         char errmsg[256];
 765         int tochan;
 766
 767         /*
 768          * If a TTY was explicitly requested, then a failure to allocate
 769          * one is fatal.
 770          */
 771         if (cr->action == CONFIRM_TTY &&
 772             (options.request_tty == REQUEST_TTY_FORCE ||
 773             options.request_tty == REQUEST_TTY_YES))
 774                 cr->action = CONFIRM_CLOSE;
 775
 776         /* XXX supress on mux _client_ quietmode */
 777         tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
 778             c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
 779
 780         if (type == SSH2_MSG_CHANNEL_SUCCESS) {
 781                 debug2("%s request accepted on channel %d",
 782                     cr->request_type, c->self);
 783         } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 784                 if (tochan) {
 785                         snprintf(errmsg, sizeof(errmsg),
 786                             "%s request failed\r\n", cr->request_type);
 787                 } else {
 788                         snprintf(errmsg, sizeof(errmsg),
 789                             "%s request failed on channel %d",
 790                             cr->request_type, c->self);
 791                 }
 792                 /* If error occurred on primary session channel, then exit */
 793                 if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
 794                         fatal("%s", errmsg);
 795                 /*
 796                  * If error occurred on mux client, append to
 797                  * their stderr.
 798                  */
 799                 if (tochan) {
 800                         buffer_append(&c->extended, errmsg,
 801                             strlen(errmsg));
 802                 } else
 803                         error("%s", errmsg);
 804                 if (cr->action == CONFIRM_TTY) {
 805                         /*
 806                          * If a TTY allocation error occurred, then arrange
 807                          * for the correct TTY to leave raw mode.
 808                          */
 809                         if (c->self == session_ident)
 810                                 leave_raw_mode(0);
 811                         else
 812                                 mux_tty_alloc_failed(c);
 813                 } else if (cr->action == CONFIRM_CLOSE) {
 814                         chan_read_failed(c);
 815                         chan_write_failed(c);
 816                 }
 817         }
 818         xfree(cr);
 819 }
 820
 821 static void
 822 client_abandon_status_confirm(Channel *c, void *ctx)
 823 {
 824         xfree(ctx);
 825 }
 826
 827 void
 828 client_expect_confirm(int id, const char *request,
 829     enum confirm_action action)
 830 {
 831         struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
 832
 833         cr->request_type = request;
 834         cr->action = action;
 835
 836         channel_register_status_confirm(id, client_status_confirm,
 837             client_abandon_status_confirm, cr);
 838 }
 839
 840 void
 841 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
 842 {
 843         struct global_confirm *gc, *last_gc;
 844
 845         /* Coalesce identical callbacks */
 846         last_gc = TAILQ_LAST(&global_confirms, global_confirms);
 847         if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
 848                 if (++last_gc->ref_count >= INT_MAX)
 849                         fatal("%s: last_gc->ref_count = %d",
 850                             __func__, last_gc->ref_count);
 851                 return;
 852         }
 853
 854         gc = xmalloc(sizeof(*gc));
 855         gc->cb = cb;
 856         gc->ctx = ctx;
 857         gc->ref_count = 1;
 858         TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
 859 }
 860
 861 static void
 862 process_cmdline(void)
 863 {
 864         void (*handler)(int);
 865         char *s, *cmd, *cancel_host;
 866         int delete = 0, local = 0, remote = 0, dynamic = 0;
 867         int cancel_port, ok;
 868         Forward fwd;
 869
 870         bzero(&fwd, sizeof(fwd));
 871         fwd.listen_host = fwd.connect_host = NULL;
 872
 873         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 874         handler = signal(SIGINT, SIG_IGN);
 875         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 876         if (s == NULL)
 877                 goto out;
 878         while (isspace(*s))
 879                 s++;
 880         if (*s == '-')
 881                 s++;    /* Skip cmdline '-', if any */
 882         if (*s == '\0')
 883                 goto out;
 884
 885         if (*s == 'h' || *s == 'H' || *s == '?') {
 886                 logit("Commands:");
 887                 logit("      -L[bind_address:]port:host:hostport    "
 888                     "Request local forward");
 889                 logit("      -R[bind_address:]port:host:hostport    "
 890                     "Request remote forward");
 891                 logit("      -D[bind_address:]port                  "
 892                     "Request dynamic forward");
 893                 logit("      -KL[bind_address:]port                 "
 894                     "Cancel local forward");
 895                 logit("      -KR[bind_address:]port                 "
 896                     "Cancel remote forward");
 897                 logit("      -KD[bind_address:]port                 "
 898                     "Cancel dynamic forward");
 899                 if (!options.permit_local_command)
 900                         goto out;
 901                 logit("      !args                                  "
 902                     "Execute local command");
 903                 goto out;
 904         }
 905
 906         if (*s == '!' && options.permit_local_command) {
 907                 s++;
 908                 ssh_local_cmd(s);
 909                 goto out;
 910         }
 911
 912         if (*s == 'K') {
 913                 delete = 1;
 914                 s++;
 915         }
 916         if (*s == 'L')
 917                 local = 1;
 918         else if (*s == 'R')
 919                 remote = 1;
 920         else if (*s == 'D')
 921                 dynamic = 1;
 922         else {
 923                 logit("Invalid command.");
 924                 goto out;
 925         }
 926
 927         if (delete && !compat20) {
 928                 logit("Not supported for SSH protocol version 1.");
 929                 goto out;
 930         }
 931
 932         while (isspace(*++s))
 933                 ;
 934
 935         /* XXX update list of forwards in options */
 936         if (delete) {
 937                 cancel_port = 0;
 938                 cancel_host = hpdelim(&s);      /* may be NULL */
 939                 if (s != NULL) {
 940                         cancel_port = a2port(s);
 941                         cancel_host = cleanhostname(cancel_host);
 942                 } else {
 943                         cancel_port = a2port(cancel_host);
 944                         cancel_host = NULL;
 945                 }
 946                 if (cancel_port <= 0) {
 947                         logit("Bad forwarding close port");
 948                         goto out;
 949                 }
 950                 if (remote)
 951                         ok = channel_request_rforward_cancel(cancel_host,
 952                             cancel_port) == 0;
 953                 else if (dynamic)
 954                         ok = channel_cancel_lport_listener(cancel_host,
 955                             cancel_port, 0, options.gateway_ports) > 0;
 956                 else
 957                         ok = channel_cancel_lport_listener(cancel_host,
 958                             cancel_port, CHANNEL_CANCEL_PORT_STATIC,
 959                             options.gateway_ports) > 0;
 960                 if (!ok) {
 961                         logit("Unkown port forwarding.");
 962                         goto out;
 963                 }
 964                 logit("Canceled forwarding.");
 965         } else {
 966                 if (!parse_forward(&fwd, s, dynamic, remote)) {
 967                         logit("Bad forwarding specification.");
 968                         goto out;
 969                 }
 970                 if (local || dynamic) {
 971                         if (channel_setup_local_fwd_listener(fwd.listen_host,
 972                             fwd.listen_port, fwd.connect_host,
 973                             fwd.connect_port, options.gateway_ports) < 0) {
 974                                 logit("Port forwarding failed.");
 975                                 goto out;
 976                         }
 977                 } else {
 978                         if (channel_request_remote_forwarding(fwd.listen_host,
 979                             fwd.listen_port, fwd.connect_host,
 980                             fwd.connect_port) < 0) {
 981                                 logit("Port forwarding failed.");
 982                                 goto out;
 983                         }
 984                 }
 985                 logit("Forwarding port.");
 986         }
 987
 988 out:
 989         signal(SIGINT, handler);
 990         enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
 991         if (cmd)
 992                 xfree(cmd);
 993         if (fwd.listen_host != NULL)
 994                 xfree(fwd.listen_host);
 995         if (fwd.connect_host != NULL)
 996                 xfree(fwd.connect_host);
 997 }
 998
 999 /*
1000  * Process the characters one by one, call with c==NULL for proto1 case.
1001  */
1002 static int
1003 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
1004     char *buf, int len)
1005 {
1006         char string[1024];
1007         pid_t pid;
1008         int bytes = 0;
1009         u_int i;
1010         u_char ch;
1011         char *s;
1012         int *escape_pendingp, escape_char;
1013         struct escape_filter_ctx *efc;
1014
1015         if (c == NULL) {
1016                 escape_pendingp = &escape_pending1;
1017                 escape_char = escape_char1;
1018         } else {
1019                 if (c->filter_ctx == NULL)
1020                         return 0;
1021                 efc = (struct escape_filter_ctx *)c->filter_ctx;
1022                 escape_pendingp = &efc->escape_pending;
1023                 escape_char = efc->escape_char;
1024         }
1025
1026         if (len <= 0)
1027                 return (0);
1028
1029         for (i = 0; i < (u_int)len; i++) {
1030                 /* Get one character at a time. */
1031                 ch = buf[i];
1032
1033                 if (*escape_pendingp) {
1034                         /* We have previously seen an escape character. */
1035                         /* Clear the flag now. */
1036                         *escape_pendingp = 0;
1037
1038                         /* Process the escaped character. */
1039                         switch (ch) {
1040                         case '.':
1041                                 /* Terminate the connection. */
1042                                 snprintf(string, sizeof string, "%c.\r\n",
1043                                     escape_char);
1044                                 buffer_append(berr, string, strlen(string));
1045
1046                                 if (c && c->ctl_chan != -1) {
1047                                         chan_read_failed(c);
1048                                         chan_write_failed(c);
1049                                         return 0;
1050                                 } else
1051                                         quit_pending = 1;
1052                                 return -1;
1053
1054                         case 'Z' - 64:
1055                                 /* XXX support this for mux clients */
1056                                 if (c && c->ctl_chan != -1) {
1057  noescape:
1058                                         snprintf(string, sizeof string,
1059                                             "%c%c escape not available to "
1060                                             "multiplexed sessions\r\n",
1061                                             escape_char, ch);
1062                                         buffer_append(berr, string,
1063                                             strlen(string));
1064                                         continue;
1065                                 }
1066                                 /* Suspend the program. Inform the user */
1067                                 snprintf(string, sizeof string,
1068                                     "%c^Z [suspend ssh]\r\n", escape_char);
1069                                 buffer_append(berr, string, strlen(string));
1070
1071                                 /* Restore terminal modes and suspend. */
1072                                 client_suspend_self(bin, bout, berr);
1073
1074                                 /* We have been continued. */
1075                                 continue;
1076
1077                         case 'B':
1078                                 if (compat20) {
1079                                         snprintf(string, sizeof string,
1080                                             "%cB\r\n", escape_char);
1081                                         buffer_append(berr, string,
1082                                             strlen(string));
1083                                         channel_request_start(session_ident,
1084                                             "break", 0);
1085                                         packet_put_int(1000);
1086                                         packet_send();
1087                                 }
1088                                 continue;
1089
1090                         case 'R':
1091                                 if (compat20) {
1092                                         if (datafellows & SSH_BUG_NOREKEY)
1093                                                 logit("Server does not "
1094                                                     "support re-keying");
1095                                         else
1096                                                 need_rekeying = 1;
1097                                 }
1098                                 continue;
1099
1100                         case '&':
1101                                 if (c && c->ctl_chan != -1)
1102                                         goto noescape;
1103                                 /*
1104                                  * Detach the program (continue to serve
1105                                  * connections, but put in background and no
1106                                  * more new connections).
1107                                  */
1108                                 /* Restore tty modes. */
1109                                 leave_raw_mode(
1110                                     options.request_tty == REQUEST_TTY_FORCE);
1111
1112                                 /* Stop listening for new connections. */
1113                                 channel_stop_listening();
1114
1115                                 snprintf(string, sizeof string,
1116                                     "%c& [backgrounded]\n", escape_char);
1117                                 buffer_append(berr, string, strlen(string));
1118
1119                                 /* Fork into background. */
1120                                 pid = fork();
1121                                 if (pid < 0) {
1122                                         error("fork: %.100s", strerror(errno));
1123                                         continue;
1124                                 }
1125                                 if (pid != 0) { /* This is the parent. */
1126                                         /* The parent just exits. */
1127                                         exit(0);
1128                                 }
1129                                 /* The child continues serving connections. */
1130                                 if (compat20) {
1131                                         buffer_append(bin, "\004", 1);
1132                                         /* fake EOF on stdin */
1133                                         return -1;
1134                                 } else if (!stdin_eof) {
1135                                         /*
1136                                          * Sending SSH_CMSG_EOF alone does not
1137                                          * always appear to be enough.  So we
1138                                          * try to send an EOF character first.
1139                                          */
1140                                         packet_start(SSH_CMSG_STDIN_DATA);
1141                                         packet_put_string("\004", 1);
1142                                         packet_send();
1143                                         /* Close stdin. */
1144                                         stdin_eof = 1;
1145                                         if (buffer_len(bin) == 0) {
1146                                                 packet_start(SSH_CMSG_EOF);
1147                                                 packet_send();
1148                                         }
1149                                 }
1150                                 continue;
1151
1152                         case '?':
1153                                 if (c && c->ctl_chan != -1) {
1154                                         snprintf(string, sizeof string,
1155 "%c?\r\n\
1156 Supported escape sequences:\r\n\
1157   %c.  - terminate session\r\n\
1158   %cB  - send a BREAK to the remote system\r\n\
1159   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1160   %c#  - list forwarded connections\r\n\
1161   %c?  - this message\r\n\
1162   %c%c  - send the escape character by typing it twice\r\n\
1163 (Note that escapes are only recognized immediately after newline.)\r\n",
1164                                             escape_char, escape_char,
1165                                             escape_char, escape_char,
1166                                             escape_char, escape_char,
1167                                             escape_char, escape_char);
1168                                 } else {
1169                                         snprintf(string, sizeof string,
1170 "%c?\r\n\
1171 Supported escape sequences:\r\n\
1172   %c.  - terminate connection (and any multiplexed sessions)\r\n\
1173   %cB  - send a BREAK to the remote system\r\n\
1174   %cC  - open a command line\r\n\
1175   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1176   %c^Z - suspend ssh\r\n\
1177   %c#  - list forwarded connections\r\n\
1178   %c&  - background ssh (when waiting for connections to terminate)\r\n\
1179   %c?  - this message\r\n\
1180   %c%c  - send the escape character by typing it twice\r\n\
1181 (Note that escapes are only recognized immediately after newline.)\r\n",
1182                                             escape_char, escape_char,
1183                                             escape_char, escape_char,
1184                                             escape_char, escape_char,
1185                                             escape_char, escape_char,
1186                                             escape_char, escape_char,
1187                                             escape_char);
1188                                 }
1189                                 buffer_append(berr, string, strlen(string));
1190                                 continue;
1191
1192                         case '#':
1193                                 snprintf(string, sizeof string, "%c#\r\n",
1194                                     escape_char);
1195                                 buffer_append(berr, string, strlen(string));
1196                                 s = channel_open_message();
1197                                 buffer_append(berr, s, strlen(s));
1198                                 xfree(s);
1199                                 continue;
1200
1201                         case 'C':
1202                                 if (c && c->ctl_chan != -1)
1203                                         goto noescape;
1204                                 process_cmdline();
1205                                 continue;
1206
1207                         default:
1208                                 if (ch != escape_char) {
1209                                         buffer_put_char(bin, escape_char);
1210                                         bytes++;
1211                                 }
1212                                 /* Escaped characters fall through here */
1213                                 break;
1214                         }
1215                 } else {
1216                         /*
1217                          * The previous character was not an escape char.
1218                          * Check if this is an escape.
1219                          */
1220                         if (last_was_cr && ch == escape_char) {
1221                                 /*
1222                                  * It is. Set the flag and continue to
1223                                  * next character.
1224                                  */
1225                                 *escape_pendingp = 1;
1226                                 continue;
1227                         }
1228                 }
1229
1230                 /*
1231                  * Normal character.  Record whether it was a newline,
1232                  * and append it to the buffer.
1233                  */
1234                 last_was_cr = (ch == '\r' || ch == '\n');
1235                 buffer_put_char(bin, ch);
1236                 bytes++;
1237         }
1238         return bytes;
1239 }
1240
1241 static void
1242 client_process_input(fd_set *readset)
1243 {
1244         int len;
1245         char buf[SSH_IOBUFSZ];
1246
1247         /* Read input from stdin. */
1248         if (FD_ISSET(fileno(stdin), readset)) {
1249                 /* Read as much as possible. */
1250                 len = read(fileno(stdin), buf, sizeof(buf));
1251                 if (len < 0 &&
1252                     (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1253                         return;         /* we'll try again later */
1254                 if (len <= 0) {
1255                         /*
1256                          * Received EOF or error.  They are treated
1257                          * similarly, except that an error message is printed
1258                          * if it was an error condition.
1259                          */
1260                         if (len < 0) {
1261                                 snprintf(buf, sizeof buf, "read: %.100s\r\n",
1262                                     strerror(errno));
1263                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1264                         }
1265                         /* Mark that we have seen EOF. */
1266                         stdin_eof = 1;
1267                         /*
1268                          * Send an EOF message to the server unless there is
1269                          * data in the buffer.  If there is data in the
1270                          * buffer, no message will be sent now.  Code
1271                          * elsewhere will send the EOF when the buffer
1272                          * becomes empty if stdin_eof is set.
1273                          */
1274                         if (buffer_len(&stdin_buffer) == 0) {
1275                                 packet_start(SSH_CMSG_EOF);
1276                                 packet_send();
1277                         }
1278                 } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1279                         /*
1280                          * Normal successful read, and no escape character.
1281                          * Just append the data to buffer.
1282                          */
1283                         buffer_append(&stdin_buffer, buf, len);
1284                 } else {
1285                         /*
1286                          * Normal, successful read.  But we have an escape
1287                          * character and have to process the characters one
1288                          * by one.
1289                          */
1290                         if (process_escapes(NULL, &stdin_buffer,
1291                             &stdout_buffer, &stderr_buffer, buf, len) == -1)
1292                                 return;
1293                 }
1294         }
1295 }
1296
1297 static void
1298 client_process_output(fd_set *writeset)
1299 {
1300         int len;
1301         char buf[100];
1302
1303         /* Write buffered output to stdout. */
1304         if (FD_ISSET(fileno(stdout), writeset)) {
1305                 /* Write as much data as possible. */
1306                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1307                     buffer_len(&stdout_buffer));
1308                 if (len <= 0) {
1309                         if (errno == EINTR || errno == EAGAIN ||
1310                             errno == EWOULDBLOCK)
1311                                 len = 0;
1312                         else {
1313                                 /*
1314                                  * An error or EOF was encountered.  Put an
1315                                  * error message to stderr buffer.
1316                                  */
1317                                 snprintf(buf, sizeof buf,
1318                                     "write stdout: %.50s\r\n", strerror(errno));
1319                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1320                                 quit_pending = 1;
1321                                 return;
1322                         }
1323                 }
1324                 /* Consume printed data from the buffer. */
1325                 buffer_consume(&stdout_buffer, len);
1326         }
1327         /* Write buffered output to stderr. */
1328         if (FD_ISSET(fileno(stderr), writeset)) {
1329                 /* Write as much data as possible. */
1330                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1331                     buffer_len(&stderr_buffer));
1332                 if (len <= 0) {
1333                         if (errno == EINTR || errno == EAGAIN ||
1334                             errno == EWOULDBLOCK)
1335                                 len = 0;
1336                         else {
1337                                 /*
1338                                  * EOF or error, but can't even print
1339                                  * error message.
1340                                  */
1341                                 quit_pending = 1;
1342                                 return;
1343                         }
1344                 }
1345                 /* Consume printed characters from the buffer. */
1346                 buffer_consume(&stderr_buffer, len);
1347         }
1348 }
1349
1350 /*
1351  * Get packets from the connection input buffer, and process them as long as
1352  * there are packets available.
1353  *
1354  * Any unknown packets received during the actual
1355  * session cause the session to terminate.  This is
1356  * intended to make debugging easier since no
1357  * confirmations are sent.  Any compatible protocol
1358  * extensions must be negotiated during the
1359  * preparatory phase.
1360  */
1361
1362 static void
1363 client_process_buffered_input_packets(void)
1364 {
1365         dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1366             compat20 ? xxx_kex : NULL);
1367 }
1368
1369 /* scan buf[] for '~' before sending data to the peer */
1370
1371 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1372 void *
1373 client_new_escape_filter_ctx(int escape_char)
1374 {
1375         struct escape_filter_ctx *ret;
1376
1377         ret = xmalloc(sizeof(*ret));
1378         ret->escape_pending = 0;
1379         ret->escape_char = escape_char;
1380         return (void *)ret;
1381 }
1382
1383 /* Free the escape filter context on channel free */
1384 void
1385 client_filter_cleanup(int cid, void *ctx)
1386 {
1387         xfree(ctx);
1388 }
1389
1390 int
1391 client_simple_escape_filter(Channel *c, char *buf, int len)
1392 {
1393         if (c->extended_usage != CHAN_EXTENDED_WRITE)
1394                 return 0;
1395
1396         return process_escapes(c, &c->input, &c->output, &c->extended,
1397             buf, len);
1398 }
1399
1400 static void
1401 client_channel_closed(int id, void *arg)
1402 {
1403         channel_cancel_cleanup(id);
1404         session_closed = 1;
1405         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1406 }
1407
1408 /*
1409  * Implements the interactive session with the server.  This is called after
1410  * the user has been authenticated, and a command has been started on the
1411  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1412  * used as an escape character for terminating or suspending the session.
1413  */
1414
1415 int
1416 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1417 {
1418         fd_set *readset = NULL, *writeset = NULL;
1419         double start_time, total_time;
1420         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1421         u_int64_t ibytes, obytes;
1422         u_int nalloc = 0;
1423         char buf[100];
1424
1425         debug("Entering interactive session.");
1426
1427         start_time = get_current_time();
1428
1429         /* Initialize variables. */
1430         escape_pending1 = 0;
1431         last_was_cr = 1;
1432         exit_status = -1;
1433         stdin_eof = 0;
1434         buffer_high = 64 * 1024;
1435         connection_in = packet_get_connection_in();
1436         connection_out = packet_get_connection_out();
1437         max_fd = MAX(connection_in, connection_out);
1438
1439         if (!compat20) {
1440                 /* enable nonblocking unless tty */
1441                 if (!isatty(fileno(stdin)))
1442                         set_nonblock(fileno(stdin));
1443                 if (!isatty(fileno(stdout)))
1444                         set_nonblock(fileno(stdout));
1445                 if (!isatty(fileno(stderr)))
1446                         set_nonblock(fileno(stderr));
1447                 max_fd = MAX(max_fd, fileno(stdin));
1448                 max_fd = MAX(max_fd, fileno(stdout));
1449                 max_fd = MAX(max_fd, fileno(stderr));
1450         }
1451         quit_pending = 0;
1452         escape_char1 = escape_char_arg;
1453
1454         /* Initialize buffers. */
1455         buffer_init(&stdin_buffer);
1456         buffer_init(&stdout_buffer);
1457         buffer_init(&stderr_buffer);
1458
1459         client_init_dispatch();
1460
1461         /*
1462          * Set signal handlers, (e.g. to restore non-blocking mode)
1463          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1464          */
1465         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1466                 signal(SIGHUP, signal_handler);
1467         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1468                 signal(SIGINT, signal_handler);
1469         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1470                 signal(SIGQUIT, signal_handler);
1471         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1472                 signal(SIGTERM, signal_handler);
1473         signal(SIGWINCH, window_change_handler);
1474
1475         if (have_pty)
1476                 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1477
1478         if (compat20) {
1479                 session_ident = ssh2_chan_id;
1480                 if (session_ident != -1) {
1481                         if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1482                                 channel_register_filter(session_ident,
1483                                     client_simple_escape_filter, NULL,
1484                                     client_filter_cleanup,
1485                                     client_new_escape_filter_ctx(
1486                                     escape_char_arg));
1487                         }
1488                         channel_register_cleanup(session_ident,
1489                             client_channel_closed, 0);
1490                 }
1491         } else {
1492                 /* Check if we should immediately send eof on stdin. */
1493                 client_check_initial_eof_on_stdin();
1494         }
1495
1496         /* Main loop of the client for the interactive session mode. */
1497         while (!quit_pending) {
1498
1499                 /* Process buffered packets sent by the server. */
1500                 client_process_buffered_input_packets();
1501
1502                 if (compat20 && session_closed && !channel_still_open())
1503                         break;
1504
1505                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1506
1507                 if (rekeying) {
1508                         debug("rekeying in progress");
1509                 } else {
1510                         /*
1511                          * Make packets of buffered stdin data, and buffer
1512                          * them for sending to the server.
1513                          */
1514                         if (!compat20)
1515                                 client_make_packets_from_stdin_data();
1516
1517                         /*
1518                          * Make packets from buffered channel data, and
1519                          * enqueue them for sending to the server.
1520                          */
1521                         if (packet_not_very_much_data_to_write())
1522                                 channel_output_poll();
1523
1524                         /*
1525                          * Check if the window size has changed, and buffer a
1526                          * message about it to the server if so.
1527                          */
1528                         client_check_window_change();
1529
1530                         if (quit_pending)
1531                                 break;
1532                 }
1533                 /*
1534                  * Wait until we have something to do (something becomes
1535                  * available on one of the descriptors).
1536                  */
1537                 max_fd2 = max_fd;
1538                 client_wait_until_can_do_something(&readset, &writeset,
1539                     &max_fd2, &nalloc, rekeying);
1540
1541                 if (quit_pending)
1542                         break;
1543
1544                 /* Do channel operations unless rekeying in progress. */
1545                 if (!rekeying) {
1546                         channel_after_select(readset, writeset);
1547                         if (need_rekeying || packet_need_rekeying()) {
1548                                 debug("need rekeying");
1549                                 xxx_kex->done = 0;
1550                                 kex_send_kexinit(xxx_kex);
1551                                 need_rekeying = 0;
1552                         }
1553                 }
1554
1555                 /* Buffer input from the connection.  */
1556                 client_process_net_input(readset);
1557
1558                 if (quit_pending)
1559                         break;
1560
1561                 if (!compat20) {
1562                         /* Buffer data from stdin */
1563                         client_process_input(readset);
1564                         /*
1565                          * Process output to stdout and stderr.  Output to
1566                          * the connection is processed elsewhere (above).
1567                          */
1568                         client_process_output(writeset);
1569                 }
1570
1571                 if (session_resumed) {
1572                         connection_in = packet_get_connection_in();
1573                         connection_out = packet_get_connection_out();
1574                         max_fd = MAX(max_fd, connection_out);
1575                         max_fd = MAX(max_fd, connection_in);
1576                         session_resumed = 0;
1577                 }
1578
1579                 /*
1580                  * Send as much buffered packet data as possible to the
1581                  * sender.
1582                  */
1583                 if (FD_ISSET(connection_out, writeset))
1584                         packet_write_poll();
1585
1586                 /*
1587                  * If we are a backgrounded control master, and the
1588                  * timeout has expired without any active client
1589                  * connections, then quit.
1590                  */
1591                 if (control_persist_exit_time > 0) {
1592                         if (time(NULL) >= control_persist_exit_time) {
1593                                 debug("ControlPersist timeout expired");
1594                                 break;
1595                         }
1596                 }
1597         }
1598         if (readset)
1599                 xfree(readset);
1600         if (writeset)
1601                 xfree(writeset);
1602
1603         /* Terminate the session. */
1604
1605         /* Stop watching for window change. */
1606         signal(SIGWINCH, SIG_DFL);
1607
1608         if (compat20) {
1609                 packet_start(SSH2_MSG_DISCONNECT);
1610                 packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1611                 packet_put_cstring("disconnected by user");
1612                 packet_put_cstring(""); /* language tag */
1613                 packet_send();
1614                 packet_write_wait();
1615         }
1616
1617         channel_free_all();
1618
1619         if (have_pty)
1620                 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1621
1622         /* restore blocking io */
1623         if (!isatty(fileno(stdin)))
1624                 unset_nonblock(fileno(stdin));
1625         if (!isatty(fileno(stdout)))
1626                 unset_nonblock(fileno(stdout));
1627         if (!isatty(fileno(stderr)))
1628                 unset_nonblock(fileno(stderr));
1629
1630         /*
1631          * If there was no shell or command requested, there will be no remote
1632          * exit status to be returned.  In that case, clear error code if the
1633          * connection was deliberately terminated at this end.
1634          */
1635         if (no_shell_flag && received_signal == SIGTERM) {
1636                 received_signal = 0;
1637                 exit_status = 0;
1638         }
1639
1640         if (received_signal)
1641                 fatal("Killed by signal %d.", (int) received_signal);
1642
1643         /*
1644          * In interactive mode (with pseudo tty) display a message indicating
1645          * that the connection has been closed.
1646          */
1647         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1648                 snprintf(buf, sizeof buf,
1649                     "Connection to %.64s closed.\r\n", host);
1650                 buffer_append(&stderr_buffer, buf, strlen(buf));
1651         }
1652
1653         /* Output any buffered data for stdout. */
1654         if (buffer_len(&stdout_buffer) > 0) {
1655                 len = atomicio(vwrite, fileno(stdout),
1656                     buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer));
1657                 if (len < 0 || (u_int)len != buffer_len(&stdout_buffer))
1658                         error("Write failed flushing stdout buffer.");
1659                 else
1660                         buffer_consume(&stdout_buffer, len);
1661         }
1662
1663         /* Output any buffered data for stderr. */
1664         if (buffer_len(&stderr_buffer) > 0) {
1665                 len = atomicio(vwrite, fileno(stderr),
1666                     buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer));
1667                 if (len < 0 || (u_int)len != buffer_len(&stderr_buffer))
1668                         error("Write failed flushing stderr buffer.");
1669                 else
1670                         buffer_consume(&stderr_buffer, len);
1671         }
1672
1673         /* Clear and free any buffers. */
1674         memset(buf, 0, sizeof(buf));
1675         buffer_free(&stdin_buffer);
1676         buffer_free(&stdout_buffer);
1677         buffer_free(&stderr_buffer);
1678
1679         /* Report bytes transferred, and transfer rates. */
1680         total_time = get_current_time() - start_time;
1681         packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
1682         packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1683         verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1684             (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1685         if (total_time > 0)
1686                 verbose("Bytes per second: sent %.1f, received %.1f",
1687                     obytes / total_time, ibytes / total_time);
1688         /* Return the exit status of the program. */
1689         debug("Exit status %d", exit_status);
1690         return exit_status;
1691 }
1692
1693 /*********/
1694
1695 static void
1696 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1697 {
1698         u_int data_len;
1699         char *data = packet_get_string(&data_len);
1700         packet_check_eom();
1701         buffer_append(&stdout_buffer, data, data_len);
1702         memset(data, 0, data_len);
1703         xfree(data);
1704 }
1705 static void
1706 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1707 {
1708         u_int data_len;
1709         char *data = packet_get_string(&data_len);
1710         packet_check_eom();
1711         buffer_append(&stderr_buffer, data, data_len);
1712         memset(data, 0, data_len);
1713         xfree(data);
1714 }
1715 static void
1716 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1717 {
1718         exit_status = packet_get_int();
1719         packet_check_eom();
1720         /* Acknowledge the exit. */
1721         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1722         packet_send();
1723         /*
1724          * Must wait for packet to be sent since we are
1725          * exiting the loop.
1726          */
1727         packet_write_wait();
1728         /* Flag that we want to exit. */
1729         quit_pending = 1;
1730 }
1731 static void
1732 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1733 {
1734         Channel *c = NULL;
1735         int remote_id, sock;
1736
1737         /* Read the remote channel number from the message. */
1738         remote_id = packet_get_int();
1739         packet_check_eom();
1740
1741         /*
1742          * Get a connection to the local authentication agent (this may again
1743          * get forwarded).
1744          */
1745         sock = ssh_get_authentication_socket();
1746
1747         /*
1748          * If we could not connect the agent, send an error message back to
1749          * the server. This should never happen unless the agent dies,
1750          * because authentication forwarding is only enabled if we have an
1751          * agent.
1752          */
1753         if (sock >= 0) {
1754                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1755                     -1, 0, 0, 0, "authentication agent connection", 1);
1756                 c->remote_id = remote_id;
1757                 c->force_drain = 1;
1758         }
1759         if (c == NULL) {
1760                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1761                 packet_put_int(remote_id);
1762         } else {
1763                 /* Send a confirmation to the remote host. */
1764                 debug("Forwarding authentication connection.");
1765                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1766                 packet_put_int(remote_id);
1767                 packet_put_int(c->self);
1768         }
1769         packet_send();
1770 }
1771
1772 static Channel *
1773 client_request_forwarded_tcpip(const char *request_type, int rchan)
1774 {
1775         Channel *c = NULL;
1776         char *listen_address, *originator_address;
1777         u_short listen_port, originator_port;
1778
1779         /* Get rest of the packet */
1780         listen_address = packet_get_string(NULL);
1781         listen_port = packet_get_int();
1782         originator_address = packet_get_string(NULL);
1783         originator_port = packet_get_int();
1784         packet_check_eom();
1785
1786         debug("client_request_forwarded_tcpip: listen %s port %d, "
1787             "originator %s port %d", listen_address, listen_port,
1788             originator_address, originator_port);
1789
1790         c = channel_connect_by_listen_address(listen_port,
1791             "forwarded-tcpip", originator_address);
1792
1793         xfree(originator_address);
1794         xfree(listen_address);
1795         return c;
1796 }
1797
1798 static Channel *
1799 client_request_x11(const char *request_type, int rchan)
1800 {
1801         Channel *c = NULL;
1802         char *originator;
1803         u_short originator_port;
1804         int sock;
1805
1806         if (!options.forward_x11) {
1807                 error("Warning: ssh server tried X11 forwarding.");
1808                 error("Warning: this is probably a break-in attempt by a "
1809                     "malicious server.");
1810                 return NULL;
1811         }
1812         if (x11_refuse_time != 0 && time(NULL) >= x11_refuse_time) {
1813                 verbose("Rejected X11 connection after ForwardX11Timeout "
1814                     "expired");
1815                 return NULL;
1816         }
1817         originator = packet_get_string(NULL);
1818         if (datafellows & SSH_BUG_X11FWD) {
1819                 debug2("buggy server: x11 request w/o originator_port");
1820                 originator_port = 0;
1821         } else {
1822                 originator_port = packet_get_int();
1823         }
1824         packet_check_eom();
1825         /* XXX check permission */
1826         debug("client_request_x11: request from %s %d", originator,
1827             originator_port);
1828         xfree(originator);
1829         sock = x11_connect_display();
1830         if (sock < 0)
1831                 return NULL;
1832         /* again is this really necessary for X11? */
1833         if (options.hpn_disabled)
1834         c = channel_new("x11",
1835             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1836             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1837         else
1838                 c = channel_new("x11",
1839                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1840                     options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1841         c->force_drain = 1;
1842         return c;
1843 }
1844
1845 static Channel *
1846 client_request_agent(const char *request_type, int rchan)
1847 {
1848         Channel *c = NULL;
1849         int sock;
1850
1851         if (!options.forward_agent) {
1852                 error("Warning: ssh server tried agent forwarding.");
1853                 error("Warning: this is probably a break-in attempt by a "
1854                     "malicious server.");
1855                 return NULL;
1856         }
1857         sock = ssh_get_authentication_socket();
1858         if (sock < 0)
1859                 return NULL;
1860         if (options.hpn_disabled)
1861         c = channel_new("authentication agent connection",
1862             SSH_CHANNEL_OPEN, sock, sock, -1,
1863                     CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1864                     "authentication agent connection", 1);
1865        else
1866         c = channel_new("authentication agent connection",
1867             SSH_CHANNEL_OPEN, sock, sock, -1,
1868                    options.hpn_buffer_size, options.hpn_buffer_size, 0,
1869             "authentication agent connection", 1);
1870         c->force_drain = 1;
1871         return c;
1872 }
1873
1874 int
1875 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1876 {
1877         Channel *c;
1878         int fd;
1879
1880         if (tun_mode == SSH_TUNMODE_NO)
1881                 return 0;
1882
1883         if (!compat20) {
1884                 error("Tunnel forwarding is not supported for protocol 1");
1885                 return -1;
1886         }
1887
1888         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1889
1890         /* Open local tunnel device */
1891         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1892                 error("Tunnel device open failed.");
1893                 return -1;
1894         }
1895
1896         if(options.hpn_disabled)
1897         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1898                                 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1899                                 0, "tun", 1);
1900         else
1901         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1902                                 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
1903                                 0, "tun", 1);
1904         c->datagram = 1;
1905
1906
1907
1908 #if defined(SSH_TUN_FILTER)
1909         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1910                 channel_register_filter(c->self, sys_tun_infilter,
1911                     sys_tun_outfilter, NULL, NULL);
1912 #endif
1913
1914         packet_start(SSH2_MSG_CHANNEL_OPEN);
1915         packet_put_cstring("tun@openssh.com");
1916         packet_put_int(c->self);
1917         packet_put_int(c->local_window_max);
1918         packet_put_int(c->local_maxpacket);
1919         packet_put_int(tun_mode);
1920         packet_put_int(remote_tun);
1921         packet_send();
1922
1923         return 0;
1924 }
1925
1926 /* XXXX move to generic input handler */
1927 static void
1928 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1929 {
1930         Channel *c = NULL;
1931         char *ctype;
1932         int rchan;
1933         u_int rmaxpack, rwindow, len;
1934
1935         ctype = packet_get_string(&len);
1936         rchan = packet_get_int();
1937         rwindow = packet_get_int();
1938         rmaxpack = packet_get_int();
1939
1940         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1941             ctype, rchan, rwindow, rmaxpack);
1942
1943         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1944                 c = client_request_forwarded_tcpip(ctype, rchan);
1945         } else if (strcmp(ctype, "x11") == 0) {
1946                 c = client_request_x11(ctype, rchan);
1947         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1948                 c = client_request_agent(ctype, rchan);
1949         }
1950 /* XXX duplicate : */
1951         if (c != NULL) {
1952                 debug("confirm %s", ctype);
1953                 c->remote_id = rchan;
1954                 c->remote_window = rwindow;
1955                 c->remote_maxpacket = rmaxpack;
1956                 if (c->type != SSH_CHANNEL_CONNECTING) {
1957                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1958                         packet_put_int(c->remote_id);
1959                         packet_put_int(c->self);
1960                         packet_put_int(c->local_window);
1961                         packet_put_int(c->local_maxpacket);
1962                         packet_send();
1963                 }
1964         } else {
1965                 debug("failure %s", ctype);
1966                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1967                 packet_put_int(rchan);
1968                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1969                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1970                         packet_put_cstring("open failed");
1971                         packet_put_cstring("");
1972                 }
1973                 packet_send();
1974         }
1975         xfree(ctype);
1976 }
1977 static void
1978 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1979 {
1980         Channel *c = NULL;
1981         int exitval, id, reply, success = 0;
1982         char *rtype;
1983
1984         id = packet_get_int();
1985         rtype = packet_get_string(NULL);
1986         reply = packet_get_char();
1987
1988         debug("client_input_channel_req: channel %d rtype %s reply %d",
1989             id, rtype, reply);
1990
1991         if (id == -1) {
1992                 error("client_input_channel_req: request for channel -1");
1993         } else if ((c = channel_lookup(id)) == NULL) {
1994                 error("client_input_channel_req: channel %d: "
1995                     "unknown channel", id);
1996         } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1997                 packet_check_eom();
1998                 chan_rcvd_eow(c);
1999         } else if (strcmp(rtype, "exit-status") == 0) {
2000                 exitval = packet_get_int();
2001                 if (c->ctl_chan != -1) {
2002                         mux_exit_message(c, exitval);
2003                         success = 1;
2004                 } else if (id == session_ident) {
2005                         /* Record exit value of local session */
2006                         success = 1;
2007                         exit_status = exitval;
2008                 } else {
2009                         /* Probably for a mux channel that has already closed */
2010                         debug("%s: no sink for exit-status on channel %d",
2011                             __func__, id);
2012                 }
2013                 packet_check_eom();
2014         }
2015         if (reply && c != NULL) {
2016                 packet_start(success ?
2017                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
2018                 packet_put_int(c->remote_id);
2019                 packet_send();
2020         }
2021         xfree(rtype);
2022 }
2023 static void
2024 client_input_global_request(int type, u_int32_t seq, void *ctxt)
2025 {
2026         char *rtype;
2027         int want_reply;
2028         int success = 0;
2029
2030         rtype = packet_get_string(NULL);
2031         want_reply = packet_get_char();
2032         debug("client_input_global_request: rtype %s want_reply %d",
2033             rtype, want_reply);
2034         if (want_reply) {
2035                 packet_start(success ?
2036                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
2037                 packet_send();
2038                 packet_write_wait();
2039         }
2040         xfree(rtype);
2041 }
2042
2043 void
2044 client_session2_setup(int id, int want_tty, int want_subsystem,
2045     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
2046 {
2047         int len;
2048         Channel *c = NULL;
2049
2050         debug2("%s: id %d", __func__, id);
2051
2052         if ((c = channel_lookup(id)) == NULL)
2053                 fatal("client_session2_setup: channel %d: unknown channel", id);
2054
2055         packet_set_interactive(want_tty,
2056             options.ip_qos_interactive, options.ip_qos_bulk);
2057
2058         if (want_tty) {
2059                 struct winsize ws;
2060
2061                 /* Store window size in the packet. */
2062                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
2063                         memset(&ws, 0, sizeof(ws));
2064
2065                 channel_request_start(id, "pty-req", 1);
2066                 client_expect_confirm(id, "PTY allocation", CONFIRM_TTY);
2067                 packet_put_cstring(term != NULL ? term : "");
2068                 packet_put_int((u_int)ws.ws_col);
2069                 packet_put_int((u_int)ws.ws_row);
2070                 packet_put_int((u_int)ws.ws_xpixel);
2071                 packet_put_int((u_int)ws.ws_ypixel);
2072                 if (tiop == NULL)
2073                         tiop = get_saved_tio();
2074                 tty_make_modes(-1, tiop);
2075                 packet_send();
2076                 /* XXX wait for reply */
2077                 c->client_tty = 1;
2078         }
2079
2080         /* Transfer any environment variables from client to server */
2081         if (options.num_send_env != 0 && env != NULL) {
2082                 int i, j, matched;
2083                 char *name, *val;
2084
2085                 debug("Sending environment.");
2086                 for (i = 0; env[i] != NULL; i++) {
2087                         /* Split */
2088                         name = xstrdup(env[i]);
2089                         if ((val = strchr(name, '=')) == NULL) {
2090                                 xfree(name);
2091                                 continue;
2092                         }
2093                         *val++ = '\0';
2094
2095                         matched = 0;
2096                         for (j = 0; j < options.num_send_env; j++) {
2097                                 if (match_pattern(name, options.send_env[j])) {
2098                                         matched = 1;
2099                                         break;
2100                                 }
2101                         }
2102                         if (!matched) {
2103                                 debug3("Ignored env %s", name);
2104                                 xfree(name);
2105                                 continue;
2106                         }
2107
2108                         debug("Sending env %s = %s", name, val);
2109                         channel_request_start(id, "env", 0);
2110                         packet_put_cstring(name);
2111                         packet_put_cstring(val);
2112                         packet_send();
2113                         xfree(name);
2114                 }
2115         }
2116
2117         len = buffer_len(cmd);
2118         if (len > 0) {
2119                 if (len > 900)
2120                         len = 900;
2121                 if (want_subsystem) {
2122                         debug("Sending subsystem: %.*s",
2123                             len, (u_char*)buffer_ptr(cmd));
2124                         channel_request_start(id, "subsystem", 1);
2125                         client_expect_confirm(id, "subsystem", CONFIRM_CLOSE);
2126                 } else {
2127                         debug("Sending command: %.*s",
2128                             len, (u_char*)buffer_ptr(cmd));
2129                         channel_request_start(id, "exec", 1);
2130                         client_expect_confirm(id, "exec", CONFIRM_CLOSE);
2131                 }
2132                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2133                 packet_send();
2134         } else {
2135                 channel_request_start(id, "shell", 1);
2136                 client_expect_confirm(id, "shell", CONFIRM_CLOSE);
2137                 packet_send();
2138         }
2139 }
2140
2141 static void
2142 client_init_dispatch_20(void)
2143 {
2144         dispatch_init(&dispatch_protocol_error);
2145
2146         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2147         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2148         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2149         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2150         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2151         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2152         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2153         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2154         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2155         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2156         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2157         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2158
2159         /* rekeying */
2160         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2161
2162         /* global request reply messages */
2163         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2164         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2165 }
2166
2167 static void
2168 client_init_dispatch_13(void)
2169 {
2170         dispatch_init(NULL);
2171         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2172         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2173         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2174         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2175         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2176         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2177         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2178         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2179         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2180
2181         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2182             &client_input_agent_open : &deny_input_open);
2183         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2184             &x11_input_open : &deny_input_open);
2185 }
2186
2187 static void
2188 client_init_dispatch_15(void)
2189 {
2190         client_init_dispatch_13();
2191         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2192         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2193 }
2194
2195 static void
2196 client_init_dispatch(void)
2197 {
2198         if (compat20)
2199                 client_init_dispatch_20();
2200         else if (compat13)
2201                 client_init_dispatch_13();
2202         else
2203                 client_init_dispatch_15();
2204 }
2205
2206 void
2207 client_stop_mux(void)
2208 {
2209         if (options.control_path != NULL && muxserver_sock != -1)
2210                 unlink(options.control_path);
2211         /*
2212          * If we are in persist mode, signal that we should close when all
2213          * active channels are closed.
2214          */
2215         if (options.control_persist) {
2216                 session_closed = 1;
2217                 setproctitle("[stopped mux]");
2218         }
2219 }
2220
2221 /* client specific fatal cleanup */
2222 void
2223 cleanup_exit(int i)
2224 {
2225         leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2226         leave_non_blocking();
2227         if (options.control_path != NULL && muxserver_sock != -1)
2228                 unlink(options.control_path);
2229         ssh_kill_proxy_command();
2230         _exit(i);
2231 }