crypto/openssh-5/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.188 2008/02/22 20:44:02 dtucker 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 "xmalloc.h"
  90 #include "ssh.h"
  91 #include "ssh1.h"
  92 #include "ssh2.h"
  93 #include "packet.h"
  94 #include "buffer.h"
  95 #include "compat.h"
  96 #include "channels.h"
  97 #include "dispatch.h"
  98 #include "key.h"
  99 #include "cipher.h"
 100 #include "kex.h"
 101 #include "log.h"
 102 #include "readconf.h"
 103 #include "clientloop.h"
 104 #include "sshconnect.h"
 105 #include "authfd.h"
 106 #include "atomicio.h"
 107 #include "sshpty.h"
 108 #include "misc.h"
 109 #include "monitor_fdpass.h"
 110 #include "match.h"
 111 #include "msg.h"
 112
 113 /* import options */
 114 extern Options options;
 115
 116 /* Flag indicating that stdin should be redirected from /dev/null. */
 117 extern int stdin_null_flag;
 118
 119 /* Flag indicating that no shell has been requested */
 120 extern int no_shell_flag;
 121
 122 /* Control socket */
 123 extern int control_fd;
 124
 125 /*
 126  * Name of the host we are connecting to.  This is the name given on the
 127  * command line, or the HostName specified for the user-supplied name in a
 128  * configuration file.
 129  */
 130 extern char *host;
 131
 132 /*
 133  * Flag to indicate that we have received a window change signal which has
 134  * not yet been processed.  This will cause a message indicating the new
 135  * window size to be sent to the server a little later.  This is volatile
 136  * because this is updated in a signal handler.
 137  */
 138 static volatile sig_atomic_t received_window_change_signal = 0;
 139 static volatile sig_atomic_t received_signal = 0;
 140
 141 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 142 static int in_non_blocking_mode = 0;
 143
 144 /* Common data for the client loop code. */
 145 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 146 static int escape_char;         /* Escape character. */
 147 static int escape_pending;      /* Last character was the escape character */
 148 static int last_was_cr;         /* Last character was a newline. */
 149 static int exit_status;         /* Used to store the exit status of the command. */
 150 static int stdin_eof;           /* EOF has been encountered on standard error. */
 151 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 152 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 153 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 154 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 155 static u_int buffer_high;/* Soft max buffer size. */
 156 static int connection_in;       /* Connection to server (input). */
 157 static int connection_out;      /* Connection to server (output). */
 158 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 159 static int session_closed = 0;  /* In SSH2: login session closed. */
 160
 161 static void client_init_dispatch(void);
 162 int     session_ident = -1;
 163
 164 struct confirm_ctx {
 165         int want_tty;
 166         int want_subsys;
 167         int want_x_fwd;
 168         int want_agent_fwd;
 169         Buffer cmd;
 170         char *term;
 171         struct termios tio;
 172         char **env;
 173 };
 174
 175 /*XXX*/
 176 extern Kex *xxx_kex;
 177
 178 void ssh_process_session2_setup(int, int, int, Buffer *);
 179
 180 /* Restores stdin to blocking mode. */
 181
 182 static void
 183 leave_non_blocking(void)
 184 {
 185         if (in_non_blocking_mode) {
 186                 unset_nonblock(fileno(stdin));
 187                 in_non_blocking_mode = 0;
 188         }
 189 }
 190
 191 /* Puts stdin terminal in non-blocking mode. */
 192
 193 static void
 194 enter_non_blocking(void)
 195 {
 196         in_non_blocking_mode = 1;
 197         set_nonblock(fileno(stdin));
 198 }
 199
 200 /*
 201  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 202  * flag indicating that the window has changed.
 203  */
 204 /*ARGSUSED */
 205 static void
 206 window_change_handler(int sig)
 207 {
 208         received_window_change_signal = 1;
 209         signal(SIGWINCH, window_change_handler);
 210 }
 211
 212 /*
 213  * Signal handler for signals that cause the program to terminate.  These
 214  * signals must be trapped to restore terminal modes.
 215  */
 216 /*ARGSUSED */
 217 static void
 218 signal_handler(int sig)
 219 {
 220         received_signal = sig;
 221         quit_pending = 1;
 222 }
 223
 224 /*
 225  * Returns current time in seconds from Jan 1, 1970 with the maximum
 226  * available resolution.
 227  */
 228
 229 static double
 230 get_current_time(void)
 231 {
 232         struct timeval tv;
 233         gettimeofday(&tv, NULL);
 234         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 235 }
 236
 237 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 238 void
 239 client_x11_get_proto(const char *display, const char *xauth_path,
 240     u_int trusted, char **_proto, char **_data)
 241 {
 242         char cmd[1024];
 243         char line[512];
 244         char xdisplay[512];
 245         static char proto[512], data[512];
 246         FILE *f;
 247         int got_data = 0, generated = 0, do_unlink = 0, i;
 248         char *xauthdir, *xauthfile;
 249         struct stat st;
 250
 251         xauthdir = xauthfile = NULL;
 252         *_proto = proto;
 253         *_data = data;
 254         proto[0] = data[0] = '\0';
 255
 256         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 257                 debug("No xauth program.");
 258         } else {
 259                 if (display == NULL) {
 260                         debug("x11_get_proto: DISPLAY not set");
 261                         return;
 262                 }
 263                 /*
 264                  * Handle FamilyLocal case where $DISPLAY does
 265                  * not match an authorization entry.  For this we
 266                  * just try "xauth list unix:displaynum.screennum".
 267                  * XXX: "localhost" match to determine FamilyLocal
 268                  *      is not perfect.
 269                  */
 270                 if (strncmp(display, "localhost:", 10) == 0) {
 271                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 272                             display + 10);
 273                         display = xdisplay;
 274                 }
 275                 if (trusted == 0) {
 276                         xauthdir = xmalloc(MAXPATHLEN);
 277                         xauthfile = xmalloc(MAXPATHLEN);
 278                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 279                         if (mkdtemp(xauthdir) != NULL) {
 280                                 do_unlink = 1;
 281                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 282                                     xauthdir);
 283                                 snprintf(cmd, sizeof(cmd),
 284                                     "%s -f %s generate %s " SSH_X11_PROTO
 285                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 286                                     xauth_path, xauthfile, display);
 287                                 debug2("x11_get_proto: %s", cmd);
 288                                 if (system(cmd) == 0)
 289                                         generated = 1;
 290                         }
 291                 }
 292
 293                 /*
 294                  * When in untrusted mode, we read the cookie only if it was
 295                  * successfully generated as an untrusted one in the step
 296                  * above.
 297                  */
 298                 if (trusted || generated) {
 299                         snprintf(cmd, sizeof(cmd),
 300                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 301                             xauth_path,
 302                             generated ? "-f " : "" ,
 303                             generated ? xauthfile : "",
 304                             display);
 305                         debug2("x11_get_proto: %s", cmd);
 306                         f = popen(cmd, "r");
 307                         if (f && fgets(line, sizeof(line), f) &&
 308                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 309                                 got_data = 1;
 310                         if (f)
 311                                 pclose(f);
 312                 } else
 313                         error("Warning: untrusted X11 forwarding setup failed: "
 314                             "xauth key data not generated");
 315         }
 316
 317         if (do_unlink) {
 318                 unlink(xauthfile);
 319                 rmdir(xauthdir);
 320         }
 321         if (xauthdir)
 322                 xfree(xauthdir);
 323         if (xauthfile)
 324                 xfree(xauthfile);
 325
 326         /*
 327          * If we didn't get authentication data, just make up some
 328          * data.  The forwarding code will check the validity of the
 329          * response anyway, and substitute this data.  The X11
 330          * server, however, will ignore this fake data and use
 331          * whatever authentication mechanisms it was using otherwise
 332          * for the local connection.
 333          */
 334         if (!got_data) {
 335                 u_int32_t rnd = 0;
 336
 337                 logit("Warning: No xauth data; "
 338                     "using fake authentication data for X11 forwarding.");
 339                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 340                 for (i = 0; i < 16; i++) {
 341                         if (i % 4 == 0)
 342                                 rnd = arc4random();
 343                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 344                             rnd & 0xff);
 345                         rnd >>= 8;
 346                 }
 347         }
 348 }
 349
 350 /*
 351  * This is called when the interactive is entered.  This checks if there is
 352  * an EOF coming on stdin.  We must check this explicitly, as select() does
 353  * not appear to wake up when redirecting from /dev/null.
 354  */
 355
 356 static void
 357 client_check_initial_eof_on_stdin(void)
 358 {
 359         int len;
 360         char buf[1];
 361
 362         /*
 363          * If standard input is to be "redirected from /dev/null", we simply
 364          * mark that we have seen an EOF and send an EOF message to the
 365          * server. Otherwise, we try to read a single character; it appears
 366          * that for some files, such /dev/null, select() never wakes up for
 367          * read for this descriptor, which means that we never get EOF.  This
 368          * way we will get the EOF if stdin comes from /dev/null or similar.
 369          */
 370         if (stdin_null_flag) {
 371                 /* Fake EOF on stdin. */
 372                 debug("Sending eof.");
 373                 stdin_eof = 1;
 374                 packet_start(SSH_CMSG_EOF);
 375                 packet_send();
 376         } else {
 377                 enter_non_blocking();
 378
 379                 /* Check for immediate EOF on stdin. */
 380                 len = read(fileno(stdin), buf, 1);
 381                 if (len == 0) {
 382                         /* EOF.  Record that we have seen it and send EOF to server. */
 383                         debug("Sending eof.");
 384                         stdin_eof = 1;
 385                         packet_start(SSH_CMSG_EOF);
 386                         packet_send();
 387                 } else if (len > 0) {
 388                         /*
 389                          * Got data.  We must store the data in the buffer,
 390                          * and also process it as an escape character if
 391                          * appropriate.
 392                          */
 393                         if ((u_char) buf[0] == escape_char)
 394                                 escape_pending = 1;
 395                         else
 396                                 buffer_append(&stdin_buffer, buf, 1);
 397                 }
 398                 leave_non_blocking();
 399         }
 400 }
 401
 402
 403 /*
 404  * Make packets from buffered stdin data, and buffer them for sending to the
 405  * connection.
 406  */
 407
 408 static void
 409 client_make_packets_from_stdin_data(void)
 410 {
 411         u_int len;
 412
 413         /* Send buffered stdin data to the server. */
 414         while (buffer_len(&stdin_buffer) > 0 &&
 415             packet_not_very_much_data_to_write()) {
 416                 len = buffer_len(&stdin_buffer);
 417                 /* Keep the packets at reasonable size. */
 418                 if (len > packet_get_maxsize())
 419                         len = packet_get_maxsize();
 420                 packet_start(SSH_CMSG_STDIN_DATA);
 421                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 422                 packet_send();
 423                 buffer_consume(&stdin_buffer, len);
 424                 stdin_bytes += len;
 425                 /* If we have a pending EOF, send it now. */
 426                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 427                         packet_start(SSH_CMSG_EOF);
 428                         packet_send();
 429                 }
 430         }
 431 }
 432
 433 /*
 434  * Checks if the client window has changed, and sends a packet about it to
 435  * the server if so.  The actual change is detected elsewhere (by a software
 436  * interrupt on Unix); this just checks the flag and sends a message if
 437  * appropriate.
 438  */
 439
 440 static void
 441 client_check_window_change(void)
 442 {
 443         struct winsize ws;
 444
 445         if (! received_window_change_signal)
 446                 return;
 447         /** XXX race */
 448         received_window_change_signal = 0;
 449
 450         debug2("client_check_window_change: changed");
 451
 452         if (compat20) {
 453                 channel_send_window_changes();
 454         } else {
 455                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 456                         return;
 457                 packet_start(SSH_CMSG_WINDOW_SIZE);
 458                 packet_put_int((u_int)ws.ws_row);
 459                 packet_put_int((u_int)ws.ws_col);
 460                 packet_put_int((u_int)ws.ws_xpixel);
 461                 packet_put_int((u_int)ws.ws_ypixel);
 462                 packet_send();
 463         }
 464 }
 465
 466 static void
 467 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 468 {
 469         keep_alive_timeouts = 0;
 470         client_global_request_reply_fwd(type, seq, ctxt);
 471 }
 472
 473 static void
 474 server_alive_check(void)
 475 {
 476         if (++keep_alive_timeouts > options.server_alive_count_max) {
 477                 logit("Timeout, server not responding.");
 478                 cleanup_exit(255);
 479         }
 480         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 481         packet_put_cstring("keepalive@openssh.com");
 482         packet_put_char(1);     /* boolean: want reply */
 483         packet_send();
 484 }
 485
 486 /*
 487  * Waits until the client can do something (some data becomes available on
 488  * one of the file descriptors).
 489  */
 490 static void
 491 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 492     int *maxfdp, u_int *nallocp, int rekeying)
 493 {
 494         struct timeval tv, *tvp;
 495         int ret;
 496
 497         /* Add any selections by the channel mechanism. */
 498         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 499
 500         if (!compat20) {
 501                 /* Read from the connection, unless our buffers are full. */
 502                 if (buffer_len(&stdout_buffer) < buffer_high &&
 503                     buffer_len(&stderr_buffer) < buffer_high &&
 504                     channel_not_very_much_buffered_data())
 505                         FD_SET(connection_in, *readsetp);
 506                 /*
 507                  * Read from stdin, unless we have seen EOF or have very much
 508                  * buffered data to send to the server.
 509                  */
 510                 if (!stdin_eof && packet_not_very_much_data_to_write())
 511                         FD_SET(fileno(stdin), *readsetp);
 512
 513                 /* Select stdout/stderr if have data in buffer. */
 514                 if (buffer_len(&stdout_buffer) > 0)
 515                         FD_SET(fileno(stdout), *writesetp);
 516                 if (buffer_len(&stderr_buffer) > 0)
 517                         FD_SET(fileno(stderr), *writesetp);
 518         } else {
 519                 /* channel_prepare_select could have closed the last channel */
 520                 if (session_closed && !channel_still_open() &&
 521                     !packet_have_data_to_write()) {
 522                         /* clear mask since we did not call select() */
 523                         memset(*readsetp, 0, *nallocp);
 524                         memset(*writesetp, 0, *nallocp);
 525                         return;
 526                 } else {
 527                         FD_SET(connection_in, *readsetp);
 528                 }
 529         }
 530
 531         /* Select server connection if have data to write to the server. */
 532         if (packet_have_data_to_write())
 533                 FD_SET(connection_out, *writesetp);
 534
 535         if (control_fd != -1)
 536                 FD_SET(control_fd, *readsetp);
 537
 538         /*
 539          * Wait for something to happen.  This will suspend the process until
 540          * some selected descriptor can be read, written, or has some other
 541          * event pending.
 542          */
 543
 544         if (options.server_alive_interval == 0 || !compat20)
 545                 tvp = NULL;
 546         else {
 547                 tv.tv_sec = options.server_alive_interval;
 548                 tv.tv_usec = 0;
 549                 tvp = &tv;
 550         }
 551         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 552         if (ret < 0) {
 553                 char buf[100];
 554
 555                 /*
 556                  * We have to clear the select masks, because we return.
 557                  * We have to return, because the mainloop checks for the flags
 558                  * set by the signal handlers.
 559                  */
 560                 memset(*readsetp, 0, *nallocp);
 561                 memset(*writesetp, 0, *nallocp);
 562
 563                 if (errno == EINTR)
 564                         return;
 565                 /* Note: we might still have data in the buffers. */
 566                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 567                 buffer_append(&stderr_buffer, buf, strlen(buf));
 568                 quit_pending = 1;
 569         } else if (ret == 0)
 570                 server_alive_check();
 571 }
 572
 573 static void
 574 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 575 {
 576         /* Flush stdout and stderr buffers. */
 577         if (buffer_len(bout) > 0)
 578                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 579         if (buffer_len(berr) > 0)
 580                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 581
 582         leave_raw_mode();
 583
 584         /*
 585          * Free (and clear) the buffer to reduce the amount of data that gets
 586          * written to swap.
 587          */
 588         buffer_free(bin);
 589         buffer_free(bout);
 590         buffer_free(berr);
 591
 592         /* Send the suspend signal to the program itself. */
 593         kill(getpid(), SIGTSTP);
 594
 595         /* Reset window sizes in case they have changed */
 596         received_window_change_signal = 1;
 597
 598         /* OK, we have been continued by the user. Reinitialize buffers. */
 599         buffer_init(bin);
 600         buffer_init(bout);
 601         buffer_init(berr);
 602
 603         enter_raw_mode();
 604 }
 605
 606 static void
 607 client_process_net_input(fd_set *readset)
 608 {
 609         int len;
 610         char buf[8192];
 611
 612         /*
 613          * Read input from the server, and add any such data to the buffer of
 614          * the packet subsystem.
 615          */
 616         if (FD_ISSET(connection_in, readset)) {
 617                 /* Read as much as possible. */
 618                 len = read(connection_in, buf, sizeof(buf));
 619                 if (len == 0) {
 620                         /* Received EOF.  The remote host has closed the connection. */
 621                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 622                                  host);
 623                         buffer_append(&stderr_buffer, buf, strlen(buf));
 624                         quit_pending = 1;
 625                         return;
 626                 }
 627                 /*
 628                  * There is a kernel bug on Solaris that causes select to
 629                  * sometimes wake up even though there is no data available.
 630                  */
 631                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 632                         len = 0;
 633
 634                 if (len < 0) {
 635                         /* An error has encountered.  Perhaps there is a network problem. */
 636                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 637                                  host, strerror(errno));
 638                         buffer_append(&stderr_buffer, buf, strlen(buf));
 639                         quit_pending = 1;
 640                         return;
 641                 }
 642                 packet_process_incoming(buf, len);
 643         }
 644 }
 645
 646 static void
 647 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 648 {
 649         int id;
 650         Channel *c;
 651
 652         id = packet_get_int();
 653         packet_check_eom();
 654
 655         if ((c = channel_lookup(id)) == NULL) {
 656                 error("%s: no channel for id %d", __func__, id);
 657                 return;
 658         }
 659
 660         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 661                 debug2("Request suceeded on channel %d", id);
 662         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 663                 error("Request failed on channel %d", id);
 664                 channel_free(c);
 665         }
 666 }
 667
 668 static void
 669 client_extra_session2_setup(int id, void *arg)
 670 {
 671         struct confirm_ctx *cctx = arg;
 672         const char *display;
 673         Channel *c;
 674         int i;
 675
 676         if (cctx == NULL)
 677                 fatal("%s: cctx == NULL", __func__);
 678         if ((c = channel_lookup(id)) == NULL)
 679                 fatal("%s: no channel for id %d", __func__, id);
 680
 681         display = getenv("DISPLAY");
 682         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 683                 char *proto, *data;
 684                 /* Get reasonable local authentication information. */
 685                 client_x11_get_proto(display, options.xauth_location,
 686                     options.forward_x11_trusted, &proto, &data);
 687                 /* Request forwarding with authentication spoofing. */
 688                 debug("Requesting X11 forwarding with authentication spoofing.");
 689                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 690                 /* XXX wait for reply */
 691         }
 692
 693         if (cctx->want_agent_fwd && options.forward_agent) {
 694                 debug("Requesting authentication agent forwarding.");
 695                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 696                 packet_send();
 697         }
 698
 699         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 700             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 701             client_subsystem_reply);
 702
 703         c->confirm_ctx = NULL;
 704         buffer_free(&cctx->cmd);
 705         xfree(cctx->term);
 706         if (cctx->env != NULL) {
 707                 for (i = 0; cctx->env[i] != NULL; i++)
 708                         xfree(cctx->env[i]);
 709                 xfree(cctx->env);
 710         }
 711         xfree(cctx);
 712 }
 713
 714 static void
 715 client_process_control(fd_set *readset)
 716 {
 717         Buffer m;
 718         Channel *c;
 719         int client_fd, new_fd[3], ver, allowed, window, packetmax;
 720         socklen_t addrlen;
 721         struct sockaddr_storage addr;
 722         struct confirm_ctx *cctx;
 723         char *cmd;
 724         u_int i, j, len, env_len, command, flags;
 725         uid_t euid;
 726         gid_t egid;
 727
 728         /*
 729          * Accept connection on control socket
 730          */
 731         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 732                 return;
 733
 734         memset(&addr, 0, sizeof(addr));
 735         addrlen = sizeof(addr);
 736         if ((client_fd = accept(control_fd,
 737             (struct sockaddr*)&addr, &addrlen)) == -1) {
 738                 error("%s accept: %s", __func__, strerror(errno));
 739                 return;
 740         }
 741
 742         if (getpeereid(client_fd, &euid, &egid) < 0) {
 743                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 744                 close(client_fd);
 745                 return;
 746         }
 747         if ((euid != 0) && (getuid() != euid)) {
 748                 error("control mode uid mismatch: peer euid %u != uid %u",
 749                     (u_int) euid, (u_int) getuid());
 750                 close(client_fd);
 751                 return;
 752         }
 753
 754         unset_nonblock(client_fd);
 755
 756         /* Read command */
 757         buffer_init(&m);
 758         if (ssh_msg_recv(client_fd, &m) == -1) {
 759                 error("%s: client msg_recv failed", __func__);
 760                 close(client_fd);
 761                 buffer_free(&m);
 762                 return;
 763         }
 764         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 765                 error("%s: wrong client version %d", __func__, ver);
 766                 buffer_free(&m);
 767                 close(client_fd);
 768                 return;
 769         }
 770
 771         allowed = 1;
 772         command = buffer_get_int(&m);
 773         flags = buffer_get_int(&m);
 774
 775         buffer_clear(&m);
 776
 777         switch (command) {
 778         case SSHMUX_COMMAND_OPEN:
 779                 if (options.control_master == SSHCTL_MASTER_ASK ||
 780                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 781                         allowed = ask_permission("Allow shared connection "
 782                             "to %s? ", host);
 783                 /* continue below */
 784                 break;
 785         case SSHMUX_COMMAND_TERMINATE:
 786                 if (options.control_master == SSHCTL_MASTER_ASK ||
 787                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 788                         allowed = ask_permission("Terminate shared connection "
 789                             "to %s? ", host);
 790                 if (allowed)
 791                         quit_pending = 1;
 792                 /* FALLTHROUGH */
 793         case SSHMUX_COMMAND_ALIVE_CHECK:
 794                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 795                 buffer_clear(&m);
 796                 buffer_put_int(&m, allowed);
 797                 buffer_put_int(&m, getpid());
 798                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 799                         error("%s: client msg_send failed", __func__);
 800                         close(client_fd);
 801                         buffer_free(&m);
 802                         return;
 803                 }
 804                 buffer_free(&m);
 805                 close(client_fd);
 806                 return;
 807         default:
 808                 error("Unsupported command %d", command);
 809                 buffer_free(&m);
 810                 close(client_fd);
 811                 return;
 812         }
 813
 814         /* Reply for SSHMUX_COMMAND_OPEN */
 815         buffer_clear(&m);
 816         buffer_put_int(&m, allowed);
 817         buffer_put_int(&m, getpid());
 818         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 819                 error("%s: client msg_send failed", __func__);
 820                 close(client_fd);
 821                 buffer_free(&m);
 822                 return;
 823         }
 824
 825         if (!allowed) {
 826                 error("Refused control connection");
 827                 close(client_fd);
 828                 buffer_free(&m);
 829                 return;
 830         }
 831
 832         buffer_clear(&m);
 833         if (ssh_msg_recv(client_fd, &m) == -1) {
 834                 error("%s: client msg_recv failed", __func__);
 835                 close(client_fd);
 836                 buffer_free(&m);
 837                 return;
 838         }
 839         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 840                 error("%s: wrong client version %d", __func__, ver);
 841                 buffer_free(&m);
 842                 close(client_fd);
 843                 return;
 844         }
 845
 846         cctx = xcalloc(1, sizeof(*cctx));
 847         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 848         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 849         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 850         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 851         cctx->term = buffer_get_string(&m, &len);
 852
 853         cmd = buffer_get_string(&m, &len);
 854         buffer_init(&cctx->cmd);
 855         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 856
 857         env_len = buffer_get_int(&m);
 858         env_len = MIN(env_len, 4096);
 859         debug3("%s: receiving %d env vars", __func__, env_len);
 860         if (env_len != 0) {
 861                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 862                 for (i = 0; i < env_len; i++)
 863                         cctx->env[i] = buffer_get_string(&m, &len);
 864                 cctx->env[i] = NULL;
 865         }
 866
 867         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 868             cctx->want_tty, cctx->want_subsys, cmd);
 869         xfree(cmd);
 870
 871         /* Gather fds from client */
 872         for(i = 0; i < 3; i++) {
 873                 if ((new_fd[i] = mm_receive_fd(client_fd)) == -1) {
 874                         error("%s: failed to receive fd %d from slave",
 875                             __func__, i);
 876                         for (j = 0; j < i; j++)
 877                                 close(new_fd[j]);
 878                         for (j = 0; j < env_len; j++)
 879                                 xfree(cctx->env[j]);
 880                         if (env_len > 0)
 881                                 xfree(cctx->env);
 882                         xfree(cctx->term);
 883                         buffer_free(&cctx->cmd);
 884                         close(client_fd);
 885                         xfree(cctx);
 886                         return;
 887                 }
 888         }
 889
 890         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 891             new_fd[0], new_fd[1], new_fd[2]);
 892
 893         /* Try to pick up ttymodes from client before it goes raw */
 894         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 895                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 896
 897         /* This roundtrip is just for synchronisation of ttymodes */
 898         buffer_clear(&m);
 899         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 900                 error("%s: client msg_send failed", __func__);
 901                 close(client_fd);
 902                 close(new_fd[0]);
 903                 close(new_fd[1]);
 904                 close(new_fd[2]);
 905                 buffer_free(&m);
 906                 xfree(cctx->term);
 907                 if (env_len != 0) {
 908                         for (i = 0; i < env_len; i++)
 909                                 xfree(cctx->env[i]);
 910                         xfree(cctx->env);
 911                 }
 912                 return;
 913         }
 914         buffer_free(&m);
 915
 916         /* enable nonblocking unless tty */
 917         if (!isatty(new_fd[0]))
 918                 set_nonblock(new_fd[0]);
 919         if (!isatty(new_fd[1]))
 920                 set_nonblock(new_fd[1]);
 921         if (!isatty(new_fd[2]))
 922                 set_nonblock(new_fd[2]);
 923
 924         set_nonblock(client_fd);
 925
 926         window = CHAN_SES_WINDOW_DEFAULT;
 927         packetmax = CHAN_SES_PACKET_DEFAULT;
 928         if (cctx->want_tty) {
 929                 window >>= 1;
 930                 packetmax >>= 1;
 931         }
 932
 933         c = channel_new("session", SSH_CHANNEL_OPENING,
 934             new_fd[0], new_fd[1], new_fd[2], window, packetmax,
 935             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 936
 937         /* XXX */
 938         c->ctl_fd = client_fd;
 939
 940         debug3("%s: channel_new: %d", __func__, c->self);
 941
 942         channel_send_open(c->self);
 943         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 944 }
 945
 946 static void
 947 process_cmdline(void)
 948 {
 949         void (*handler)(int);
 950         char *s, *cmd, *cancel_host;
 951         int delete = 0;
 952         int local = 0;
 953         u_short cancel_port;
 954         Forward fwd;
 955
 956         bzero(&fwd, sizeof(fwd));
 957         fwd.listen_host = fwd.connect_host = NULL;
 958
 959         leave_raw_mode();
 960         handler = signal(SIGINT, SIG_IGN);
 961         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 962         if (s == NULL)
 963                 goto out;
 964         while (isspace(*s))
 965                 s++;
 966         if (*s == '-')
 967                 s++;    /* Skip cmdline '-', if any */
 968         if (*s == '\0')
 969                 goto out;
 970
 971         if (*s == 'h' || *s == 'H' || *s == '?') {
 972                 logit("Commands:");
 973                 logit("      -L[bind_address:]port:host:hostport    "
 974                     "Request local forward");
 975                 logit("      -R[bind_address:]port:host:hostport    "
 976                     "Request remote forward");
 977                 logit("      -KR[bind_address:]port                 "
 978                     "Cancel remote forward");
 979                 if (!options.permit_local_command)
 980                         goto out;
 981                 logit("      !args                                  "
 982                     "Execute local command");
 983                 goto out;
 984         }
 985
 986         if (*s == '!' && options.permit_local_command) {
 987                 s++;
 988                 ssh_local_cmd(s);
 989                 goto out;
 990         }
 991
 992         if (*s == 'K') {
 993                 delete = 1;
 994                 s++;
 995         }
 996         if (*s != 'L' && *s != 'R') {
 997                 logit("Invalid command.");
 998                 goto out;
 999         }
1000         if (*s == 'L')
1001                 local = 1;
1002         if (local && delete) {
1003                 logit("Not supported.");
1004                 goto out;
1005         }
1006         if ((!local || delete) && !compat20) {
1007                 logit("Not supported for SSH protocol version 1.");
1008                 goto out;
1009         }
1010
1011         while (isspace(*++s))
1012                 ;
1013
1014         if (delete) {
1015                 cancel_port = 0;
1016                 cancel_host = hpdelim(&s);      /* may be NULL */
1017                 if (s != NULL) {
1018                         cancel_port = a2port(s);
1019                         cancel_host = cleanhostname(cancel_host);
1020                 } else {
1021                         cancel_port = a2port(cancel_host);
1022                         cancel_host = NULL;
1023                 }
1024                 if (cancel_port == 0) {
1025                         logit("Bad forwarding close port");
1026                         goto out;
1027                 }
1028                 channel_request_rforward_cancel(cancel_host, cancel_port);
1029         } else {
1030                 if (!parse_forward(&fwd, s)) {
1031                         logit("Bad forwarding specification.");
1032                         goto out;
1033                 }
1034                 if (local) {
1035                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1036                             fwd.listen_port, fwd.connect_host,
1037                             fwd.connect_port, options.gateway_ports) < 0) {
1038                                 logit("Port forwarding failed.");
1039                                 goto out;
1040                         }
1041                 } else {
1042                         if (channel_request_remote_forwarding(fwd.listen_host,
1043                             fwd.listen_port, fwd.connect_host,
1044                             fwd.connect_port) < 0) {
1045                                 logit("Port forwarding failed.");
1046                                 goto out;
1047                         }
1048                 }
1049
1050                 logit("Forwarding port.");
1051         }
1052
1053 out:
1054         signal(SIGINT, handler);
1055         enter_raw_mode();
1056         if (cmd)
1057                 xfree(cmd);
1058         if (fwd.listen_host != NULL)
1059                 xfree(fwd.listen_host);
1060         if (fwd.connect_host != NULL)
1061                 xfree(fwd.connect_host);
1062 }
1063
1064 /* process the characters one by one */
1065 static int
1066 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1067 {
1068         char string[1024];
1069         pid_t pid;
1070         int bytes = 0;
1071         u_int i;
1072         u_char ch;
1073         char *s;
1074
1075         if (len <= 0)
1076                 return (0);
1077
1078         for (i = 0; i < (u_int)len; i++) {
1079                 /* Get one character at a time. */
1080                 ch = buf[i];
1081
1082                 if (escape_pending) {
1083                         /* We have previously seen an escape character. */
1084                         /* Clear the flag now. */
1085                         escape_pending = 0;
1086
1087                         /* Process the escaped character. */
1088                         switch (ch) {
1089                         case '.':
1090                                 /* Terminate the connection. */
1091                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1092                                 buffer_append(berr, string, strlen(string));
1093
1094                                 quit_pending = 1;
1095                                 return -1;
1096
1097                         case 'Z' - 64:
1098                                 /* Suspend the program. */
1099                                 /* Print a message to that effect to the user. */
1100                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1101                                 buffer_append(berr, string, strlen(string));
1102
1103                                 /* Restore terminal modes and suspend. */
1104                                 client_suspend_self(bin, bout, berr);
1105
1106                                 /* We have been continued. */
1107                                 continue;
1108
1109                         case 'B':
1110                                 if (compat20) {
1111                                         snprintf(string, sizeof string,
1112                                             "%cB\r\n", escape_char);
1113                                         buffer_append(berr, string,
1114                                             strlen(string));
1115                                         channel_request_start(session_ident,
1116                                             "break", 0);
1117                                         packet_put_int(1000);
1118                                         packet_send();
1119                                 }
1120                                 continue;
1121
1122                         case 'R':
1123                                 if (compat20) {
1124                                         if (datafellows & SSH_BUG_NOREKEY)
1125                                                 logit("Server does not support re-keying");
1126                                         else
1127                                                 need_rekeying = 1;
1128                                 }
1129                                 continue;
1130
1131                         case '&':
1132                                 /*
1133                                  * Detach the program (continue to serve connections,
1134                                  * but put in background and no more new connections).
1135                                  */
1136                                 /* Restore tty modes. */
1137                                 leave_raw_mode();
1138
1139                                 /* Stop listening for new connections. */
1140                                 channel_stop_listening();
1141
1142                                 snprintf(string, sizeof string,
1143                                     "%c& [backgrounded]\n", escape_char);
1144                                 buffer_append(berr, string, strlen(string));
1145
1146                                 /* Fork into background. */
1147                                 pid = fork();
1148                                 if (pid < 0) {
1149                                         error("fork: %.100s", strerror(errno));
1150                                         continue;
1151                                 }
1152                                 if (pid != 0) { /* This is the parent. */
1153                                         /* The parent just exits. */
1154                                         exit(0);
1155                                 }
1156                                 /* The child continues serving connections. */
1157                                 if (compat20) {
1158                                         buffer_append(bin, "\004", 1);
1159                                         /* fake EOF on stdin */
1160                                         return -1;
1161                                 } else if (!stdin_eof) {
1162                                         /*
1163                                          * Sending SSH_CMSG_EOF alone does not always appear
1164                                          * to be enough.  So we try to send an EOF character
1165                                          * first.
1166                                          */
1167                                         packet_start(SSH_CMSG_STDIN_DATA);
1168                                         packet_put_string("\004", 1);
1169                                         packet_send();
1170                                         /* Close stdin. */
1171                                         stdin_eof = 1;
1172                                         if (buffer_len(bin) == 0) {
1173                                                 packet_start(SSH_CMSG_EOF);
1174                                                 packet_send();
1175                                         }
1176                                 }
1177                                 continue;
1178
1179                         case '?':
1180                                 snprintf(string, sizeof string,
1181 "%c?\r\n\
1182 Supported escape sequences:\r\n\
1183 %c.  - terminate connection\r\n\
1184 %cB  - send a BREAK to the remote system\r\n\
1185 %cC  - open a command line\r\n\
1186 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1187 %c^Z - suspend ssh\r\n\
1188 %c#  - list forwarded connections\r\n\
1189 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1190 %c?  - this message\r\n\
1191 %c%c  - send the escape character by typing it twice\r\n\
1192 (Note that escapes are only recognized immediately after newline.)\r\n",
1193                                     escape_char, escape_char, escape_char, escape_char,
1194                                     escape_char, escape_char, escape_char, escape_char,
1195                                     escape_char, escape_char, escape_char);
1196                                 buffer_append(berr, string, strlen(string));
1197                                 continue;
1198
1199                         case '#':
1200                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1201                                 buffer_append(berr, string, strlen(string));
1202                                 s = channel_open_message();
1203                                 buffer_append(berr, s, strlen(s));
1204                                 xfree(s);
1205                                 continue;
1206
1207                         case 'C':
1208                                 process_cmdline();
1209                                 continue;
1210
1211                         default:
1212                                 if (ch != escape_char) {
1213                                         buffer_put_char(bin, escape_char);
1214                                         bytes++;
1215                                 }
1216                                 /* Escaped characters fall through here */
1217                                 break;
1218                         }
1219                 } else {
1220                         /*
1221                          * The previous character was not an escape char. Check if this
1222                          * is an escape.
1223                          */
1224                         if (last_was_cr && ch == escape_char) {
1225                                 /* It is. Set the flag and continue to next character. */
1226                                 escape_pending = 1;
1227                                 continue;
1228                         }
1229                 }
1230
1231                 /*
1232                  * Normal character.  Record whether it was a newline,
1233                  * and append it to the buffer.
1234                  */
1235                 last_was_cr = (ch == '\r' || ch == '\n');
1236                 buffer_put_char(bin, ch);
1237                 bytes++;
1238         }
1239         return bytes;
1240 }
1241
1242 static void
1243 client_process_input(fd_set *readset)
1244 {
1245         int len;
1246         char buf[8192];
1247
1248         /* Read input from stdin. */
1249         if (FD_ISSET(fileno(stdin), readset)) {
1250                 /* Read as much as possible. */
1251                 len = read(fileno(stdin), buf, sizeof(buf));
1252                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
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", strerror(errno));
1262                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1263                         }
1264                         /* Mark that we have seen EOF. */
1265                         stdin_eof = 1;
1266                         /*
1267                          * Send an EOF message to the server unless there is
1268                          * data in the buffer.  If there is data in the
1269                          * buffer, no message will be sent now.  Code
1270                          * elsewhere will send the EOF when the buffer
1271                          * becomes empty if stdin_eof is set.
1272                          */
1273                         if (buffer_len(&stdin_buffer) == 0) {
1274                                 packet_start(SSH_CMSG_EOF);
1275                                 packet_send();
1276                         }
1277                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1278                         /*
1279                          * Normal successful read, and no escape character.
1280                          * Just append the data to buffer.
1281                          */
1282                         buffer_append(&stdin_buffer, buf, len);
1283                 } else {
1284                         /*
1285                          * Normal, successful read.  But we have an escape character
1286                          * and have to process the characters one by one.
1287                          */
1288                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1289                             &stderr_buffer, buf, len) == -1)
1290                                 return;
1291                 }
1292         }
1293 }
1294
1295 static void
1296 client_process_output(fd_set *writeset)
1297 {
1298         int len;
1299         char buf[100];
1300
1301         /* Write buffered output to stdout. */
1302         if (FD_ISSET(fileno(stdout), writeset)) {
1303                 /* Write as much data as possible. */
1304                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1305                     buffer_len(&stdout_buffer));
1306                 if (len <= 0) {
1307                         if (errno == EINTR || errno == EAGAIN)
1308                                 len = 0;
1309                         else {
1310                                 /*
1311                                  * An error or EOF was encountered.  Put an
1312                                  * error message to stderr buffer.
1313                                  */
1314                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1315                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1316                                 quit_pending = 1;
1317                                 return;
1318                         }
1319                 }
1320                 /* Consume printed data from the buffer. */
1321                 buffer_consume(&stdout_buffer, len);
1322                 stdout_bytes += len;
1323         }
1324         /* Write buffered output to stderr. */
1325         if (FD_ISSET(fileno(stderr), writeset)) {
1326                 /* Write as much data as possible. */
1327                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1328                     buffer_len(&stderr_buffer));
1329                 if (len <= 0) {
1330                         if (errno == EINTR || errno == EAGAIN)
1331                                 len = 0;
1332                         else {
1333                                 /* EOF or error, but can't even print error message. */
1334                                 quit_pending = 1;
1335                                 return;
1336                         }
1337                 }
1338                 /* Consume printed characters from the buffer. */
1339                 buffer_consume(&stderr_buffer, len);
1340                 stderr_bytes += len;
1341         }
1342 }
1343
1344 /*
1345  * Get packets from the connection input buffer, and process them as long as
1346  * there are packets available.
1347  *
1348  * Any unknown packets received during the actual
1349  * session cause the session to terminate.  This is
1350  * intended to make debugging easier since no
1351  * confirmations are sent.  Any compatible protocol
1352  * extensions must be negotiated during the
1353  * preparatory phase.
1354  */
1355
1356 static void
1357 client_process_buffered_input_packets(void)
1358 {
1359         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1360 }
1361
1362 /* scan buf[] for '~' before sending data to the peer */
1363
1364 static int
1365 simple_escape_filter(Channel *c, char *buf, int len)
1366 {
1367         /* XXX we assume c->extended is writeable */
1368         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1369 }
1370
1371 static void
1372 client_channel_closed(int id, void *arg)
1373 {
1374         channel_cancel_cleanup(id);
1375         session_closed = 1;
1376         leave_raw_mode();
1377 }
1378
1379 /*
1380  * Implements the interactive session with the server.  This is called after
1381  * the user has been authenticated, and a command has been started on the
1382  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1383  * used as an escape character for terminating or suspending the session.
1384  */
1385
1386 int
1387 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1388 {
1389         fd_set *readset = NULL, *writeset = NULL;
1390         double start_time, total_time;
1391         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1392         u_int nalloc = 0;
1393         char buf[100];
1394
1395         debug("Entering interactive session.");
1396
1397         start_time = get_current_time();
1398
1399         /* Initialize variables. */
1400         escape_pending = 0;
1401         last_was_cr = 1;
1402         exit_status = -1;
1403         stdin_eof = 0;
1404         buffer_high = 64 * 1024;
1405         connection_in = packet_get_connection_in();
1406         connection_out = packet_get_connection_out();
1407         max_fd = MAX(connection_in, connection_out);
1408         if (control_fd != -1)
1409                 max_fd = MAX(max_fd, control_fd);
1410
1411         if (!compat20) {
1412                 /* enable nonblocking unless tty */
1413                 if (!isatty(fileno(stdin)))
1414                         set_nonblock(fileno(stdin));
1415                 if (!isatty(fileno(stdout)))
1416                         set_nonblock(fileno(stdout));
1417                 if (!isatty(fileno(stderr)))
1418                         set_nonblock(fileno(stderr));
1419                 max_fd = MAX(max_fd, fileno(stdin));
1420                 max_fd = MAX(max_fd, fileno(stdout));
1421                 max_fd = MAX(max_fd, fileno(stderr));
1422         }
1423         stdin_bytes = 0;
1424         stdout_bytes = 0;
1425         stderr_bytes = 0;
1426         quit_pending = 0;
1427         escape_char = escape_char_arg;
1428
1429         /* Initialize buffers. */
1430         buffer_init(&stdin_buffer);
1431         buffer_init(&stdout_buffer);
1432         buffer_init(&stderr_buffer);
1433
1434         client_init_dispatch();
1435
1436         /*
1437          * Set signal handlers, (e.g. to restore non-blocking mode)
1438          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1439          */
1440         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1441                 signal(SIGHUP, signal_handler);
1442         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1443                 signal(SIGINT, signal_handler);
1444         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1445                 signal(SIGQUIT, signal_handler);
1446         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1447                 signal(SIGTERM, signal_handler);
1448         signal(SIGWINCH, window_change_handler);
1449
1450         if (have_pty)
1451                 enter_raw_mode();
1452
1453         if (compat20) {
1454                 session_ident = ssh2_chan_id;
1455                 if (escape_char != SSH_ESCAPECHAR_NONE)
1456                         channel_register_filter(session_ident,
1457                             simple_escape_filter, NULL);
1458                 if (session_ident != -1)
1459                         channel_register_cleanup(session_ident,
1460                             client_channel_closed, 0);
1461         } else {
1462                 /* Check if we should immediately send eof on stdin. */
1463                 client_check_initial_eof_on_stdin();
1464         }
1465
1466         /* Main loop of the client for the interactive session mode. */
1467         while (!quit_pending) {
1468
1469                 /* Process buffered packets sent by the server. */
1470                 client_process_buffered_input_packets();
1471
1472                 if (compat20 && session_closed && !channel_still_open())
1473                         break;
1474
1475                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1476
1477                 if (rekeying) {
1478                         debug("rekeying in progress");
1479                 } else {
1480                         /*
1481                          * Make packets of buffered stdin data, and buffer
1482                          * them for sending to the server.
1483                          */
1484                         if (!compat20)
1485                                 client_make_packets_from_stdin_data();
1486
1487                         /*
1488                          * Make packets from buffered channel data, and
1489                          * enqueue them for sending to the server.
1490                          */
1491                         if (packet_not_very_much_data_to_write())
1492                                 channel_output_poll();
1493
1494                         /*
1495                          * Check if the window size has changed, and buffer a
1496                          * message about it to the server if so.
1497                          */
1498                         client_check_window_change();
1499
1500                         if (quit_pending)
1501                                 break;
1502                 }
1503                 /*
1504                  * Wait until we have something to do (something becomes
1505                  * available on one of the descriptors).
1506                  */
1507                 max_fd2 = max_fd;
1508                 client_wait_until_can_do_something(&readset, &writeset,
1509                     &max_fd2, &nalloc, rekeying);
1510
1511                 if (quit_pending)
1512                         break;
1513
1514                 /* Do channel operations unless rekeying in progress. */
1515                 if (!rekeying) {
1516                         channel_after_select(readset, writeset);
1517                         if (need_rekeying || packet_need_rekeying()) {
1518                                 debug("need rekeying");
1519                                 xxx_kex->done = 0;
1520                                 kex_send_kexinit(xxx_kex);
1521                                 need_rekeying = 0;
1522                         }
1523                 }
1524
1525                 /* Buffer input from the connection.  */
1526                 client_process_net_input(readset);
1527
1528                 /* Accept control connections.  */
1529                 client_process_control(readset);
1530
1531                 if (quit_pending)
1532                         break;
1533
1534                 if (!compat20) {
1535                         /* Buffer data from stdin */
1536                         client_process_input(readset);
1537                         /*
1538                          * Process output to stdout and stderr.  Output to
1539                          * the connection is processed elsewhere (above).
1540                          */
1541                         client_process_output(writeset);
1542                 }
1543
1544                 /* Send as much buffered packet data as possible to the sender. */
1545                 if (FD_ISSET(connection_out, writeset))
1546                         packet_write_poll();
1547         }
1548         if (readset)
1549                 xfree(readset);
1550         if (writeset)
1551                 xfree(writeset);
1552
1553         /* Terminate the session. */
1554
1555         /* Stop watching for window change. */
1556         signal(SIGWINCH, SIG_DFL);
1557
1558         channel_free_all();
1559
1560         if (have_pty)
1561                 leave_raw_mode();
1562
1563         /* restore blocking io */
1564         if (!isatty(fileno(stdin)))
1565                 unset_nonblock(fileno(stdin));
1566         if (!isatty(fileno(stdout)))
1567                 unset_nonblock(fileno(stdout));
1568         if (!isatty(fileno(stderr)))
1569                 unset_nonblock(fileno(stderr));
1570
1571         /*
1572          * If there was no shell or command requested, there will be no remote
1573          * exit status to be returned.  In that case, clear error code if the
1574          * connection was deliberately terminated at this end.
1575          */
1576         if (no_shell_flag && received_signal == SIGTERM) {
1577                 received_signal = 0;
1578                 exit_status = 0;
1579         }
1580
1581         if (received_signal)
1582                 fatal("Killed by signal %d.", (int) received_signal);
1583
1584         /*
1585          * In interactive mode (with pseudo tty) display a message indicating
1586          * that the connection has been closed.
1587          */
1588         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1589                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1590                 buffer_append(&stderr_buffer, buf, strlen(buf));
1591         }
1592
1593         /* Output any buffered data for stdout. */
1594         while (buffer_len(&stdout_buffer) > 0) {
1595                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1596                     buffer_len(&stdout_buffer));
1597                 if (len <= 0) {
1598                         error("Write failed flushing stdout buffer.");
1599                         break;
1600                 }
1601                 buffer_consume(&stdout_buffer, len);
1602                 stdout_bytes += len;
1603         }
1604
1605         /* Output any buffered data for stderr. */
1606         while (buffer_len(&stderr_buffer) > 0) {
1607                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1608                     buffer_len(&stderr_buffer));
1609                 if (len <= 0) {
1610                         error("Write failed flushing stderr buffer.");
1611                         break;
1612                 }
1613                 buffer_consume(&stderr_buffer, len);
1614                 stderr_bytes += len;
1615         }
1616
1617         /* Clear and free any buffers. */
1618         memset(buf, 0, sizeof(buf));
1619         buffer_free(&stdin_buffer);
1620         buffer_free(&stdout_buffer);
1621         buffer_free(&stderr_buffer);
1622
1623         /* Report bytes transferred, and transfer rates. */
1624         total_time = get_current_time() - start_time;
1625         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1626             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1627         if (total_time > 0)
1628                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1629                     stdin_bytes / total_time, stdout_bytes / total_time,
1630                     stderr_bytes / total_time);
1631
1632         /* Return the exit status of the program. */
1633         debug("Exit status %d", exit_status);
1634         return exit_status;
1635 }
1636
1637 /*********/
1638
1639 static void
1640 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1641 {
1642         u_int data_len;
1643         char *data = packet_get_string(&data_len);
1644         packet_check_eom();
1645         buffer_append(&stdout_buffer, data, data_len);
1646         memset(data, 0, data_len);
1647         xfree(data);
1648 }
1649 static void
1650 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1651 {
1652         u_int data_len;
1653         char *data = packet_get_string(&data_len);
1654         packet_check_eom();
1655         buffer_append(&stderr_buffer, data, data_len);
1656         memset(data, 0, data_len);
1657         xfree(data);
1658 }
1659 static void
1660 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1661 {
1662         exit_status = packet_get_int();
1663         packet_check_eom();
1664         /* Acknowledge the exit. */
1665         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1666         packet_send();
1667         /*
1668          * Must wait for packet to be sent since we are
1669          * exiting the loop.
1670          */
1671         packet_write_wait();
1672         /* Flag that we want to exit. */
1673         quit_pending = 1;
1674 }
1675 static void
1676 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1677 {
1678         Channel *c = NULL;
1679         int remote_id, sock;
1680
1681         /* Read the remote channel number from the message. */
1682         remote_id = packet_get_int();
1683         packet_check_eom();
1684
1685         /*
1686          * Get a connection to the local authentication agent (this may again
1687          * get forwarded).
1688          */
1689         sock = ssh_get_authentication_socket();
1690
1691         /*
1692          * If we could not connect the agent, send an error message back to
1693          * the server. This should never happen unless the agent dies,
1694          * because authentication forwarding is only enabled if we have an
1695          * agent.
1696          */
1697         if (sock >= 0) {
1698                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1699                     -1, 0, 0, 0, "authentication agent connection", 1);
1700                 c->remote_id = remote_id;
1701                 c->force_drain = 1;
1702         }
1703         if (c == NULL) {
1704                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1705                 packet_put_int(remote_id);
1706         } else {
1707                 /* Send a confirmation to the remote host. */
1708                 debug("Forwarding authentication connection.");
1709                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1710                 packet_put_int(remote_id);
1711                 packet_put_int(c->self);
1712         }
1713         packet_send();
1714 }
1715
1716 static Channel *
1717 client_request_forwarded_tcpip(const char *request_type, int rchan)
1718 {
1719         Channel *c = NULL;
1720         char *listen_address, *originator_address;
1721         int listen_port, originator_port;
1722         int sock;
1723
1724         /* Get rest of the packet */
1725         listen_address = packet_get_string(NULL);
1726         listen_port = packet_get_int();
1727         originator_address = packet_get_string(NULL);
1728         originator_port = packet_get_int();
1729         packet_check_eom();
1730
1731         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1732             listen_address, listen_port, originator_address, originator_port);
1733
1734         sock = channel_connect_by_listen_address(listen_port);
1735         if (sock < 0) {
1736                 xfree(originator_address);
1737                 xfree(listen_address);
1738                 return NULL;
1739         }
1740         c = channel_new("forwarded-tcpip",
1741             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1742             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1743             originator_address, 1);
1744         xfree(originator_address);
1745         xfree(listen_address);
1746         return c;
1747 }
1748
1749 static Channel *
1750 client_request_x11(const char *request_type, int rchan)
1751 {
1752         Channel *c = NULL;
1753         char *originator;
1754         int originator_port;
1755         int sock;
1756
1757         if (!options.forward_x11) {
1758                 error("Warning: ssh server tried X11 forwarding.");
1759                 error("Warning: this is probably a break-in attempt by a malicious server.");
1760                 return NULL;
1761         }
1762         originator = packet_get_string(NULL);
1763         if (datafellows & SSH_BUG_X11FWD) {
1764                 debug2("buggy server: x11 request w/o originator_port");
1765                 originator_port = 0;
1766         } else {
1767                 originator_port = packet_get_int();
1768         }
1769         packet_check_eom();
1770         /* XXX check permission */
1771         debug("client_request_x11: request from %s %d", originator,
1772             originator_port);
1773         xfree(originator);
1774         sock = x11_connect_display();
1775         if (sock < 0)
1776                 return NULL;
1777         c = channel_new("x11",
1778             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1779             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1780         c->force_drain = 1;
1781         return c;
1782 }
1783
1784 static Channel *
1785 client_request_agent(const char *request_type, int rchan)
1786 {
1787         Channel *c = NULL;
1788         int sock;
1789
1790         if (!options.forward_agent) {
1791                 error("Warning: ssh server tried agent forwarding.");
1792                 error("Warning: this is probably a break-in attempt by a malicious server.");
1793                 return NULL;
1794         }
1795         sock = ssh_get_authentication_socket();
1796         if (sock < 0)
1797                 return NULL;
1798         c = channel_new("authentication agent connection",
1799             SSH_CHANNEL_OPEN, sock, sock, -1,
1800             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1801             "authentication agent connection", 1);
1802         c->force_drain = 1;
1803         return c;
1804 }
1805
1806 int
1807 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1808 {
1809         Channel *c;
1810         int fd;
1811
1812         if (tun_mode == SSH_TUNMODE_NO)
1813                 return 0;
1814
1815         if (!compat20) {
1816                 error("Tunnel forwarding is not support for protocol 1");
1817                 return -1;
1818         }
1819
1820         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1821
1822         /* Open local tunnel device */
1823         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1824                 error("Tunnel device open failed.");
1825                 return -1;
1826         }
1827
1828         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1829             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1830         c->datagram = 1;
1831
1832 #if defined(SSH_TUN_FILTER)
1833         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1834                 channel_register_filter(c->self, sys_tun_infilter,
1835                     sys_tun_outfilter);
1836 #endif
1837
1838         packet_start(SSH2_MSG_CHANNEL_OPEN);
1839         packet_put_cstring("tun@openssh.com");
1840         packet_put_int(c->self);
1841         packet_put_int(c->local_window_max);
1842         packet_put_int(c->local_maxpacket);
1843         packet_put_int(tun_mode);
1844         packet_put_int(remote_tun);
1845         packet_send();
1846
1847         return 0;
1848 }
1849
1850 /* XXXX move to generic input handler */
1851 static void
1852 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1853 {
1854         Channel *c = NULL;
1855         char *ctype;
1856         int rchan;
1857         u_int rmaxpack, rwindow, len;
1858
1859         ctype = packet_get_string(&len);
1860         rchan = packet_get_int();
1861         rwindow = packet_get_int();
1862         rmaxpack = packet_get_int();
1863
1864         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1865             ctype, rchan, rwindow, rmaxpack);
1866
1867         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1868                 c = client_request_forwarded_tcpip(ctype, rchan);
1869         } else if (strcmp(ctype, "x11") == 0) {
1870                 c = client_request_x11(ctype, rchan);
1871         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1872                 c = client_request_agent(ctype, rchan);
1873         }
1874 /* XXX duplicate : */
1875         if (c != NULL) {
1876                 debug("confirm %s", ctype);
1877                 c->remote_id = rchan;
1878                 c->remote_window = rwindow;
1879                 c->remote_maxpacket = rmaxpack;
1880                 if (c->type != SSH_CHANNEL_CONNECTING) {
1881                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1882                         packet_put_int(c->remote_id);
1883                         packet_put_int(c->self);
1884                         packet_put_int(c->local_window);
1885                         packet_put_int(c->local_maxpacket);
1886                         packet_send();
1887                 }
1888         } else {
1889                 debug("failure %s", ctype);
1890                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1891                 packet_put_int(rchan);
1892                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1893                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1894                         packet_put_cstring("open failed");
1895                         packet_put_cstring("");
1896                 }
1897                 packet_send();
1898         }
1899         xfree(ctype);
1900 }
1901 static void
1902 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1903 {
1904         Channel *c = NULL;
1905         int exitval, id, reply, success = 0;
1906         char *rtype;
1907
1908         id = packet_get_int();
1909         rtype = packet_get_string(NULL);
1910         reply = packet_get_char();
1911
1912         debug("client_input_channel_req: channel %d rtype %s reply %d",
1913             id, rtype, reply);
1914
1915         if (id == -1) {
1916                 error("client_input_channel_req: request for channel -1");
1917         } else if ((c = channel_lookup(id)) == NULL) {
1918                 error("client_input_channel_req: channel %d: unknown channel", id);
1919         } else if (strcmp(rtype, "exit-status") == 0) {
1920                 exitval = packet_get_int();
1921                 if (id == session_ident) {
1922                         success = 1;
1923                         exit_status = exitval;
1924                 } else if (c->ctl_fd == -1) {
1925                         error("client_input_channel_req: unexpected channel %d",
1926                             session_ident);
1927                 } else {
1928                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1929                         success = 1;
1930                 }
1931                 packet_check_eom();
1932         }
1933         if (reply) {
1934                 packet_start(success ?
1935                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1936                 packet_put_int(id);
1937                 packet_send();
1938         }
1939         xfree(rtype);
1940 }
1941 static void
1942 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1943 {
1944         char *rtype;
1945         int want_reply;
1946         int success = 0;
1947
1948         rtype = packet_get_string(NULL);
1949         want_reply = packet_get_char();
1950         debug("client_input_global_request: rtype %s want_reply %d",
1951             rtype, want_reply);
1952         if (want_reply) {
1953                 packet_start(success ?
1954                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1955                 packet_send();
1956                 packet_write_wait();
1957         }
1958         xfree(rtype);
1959 }
1960
1961 void
1962 client_session2_setup(int id, int want_tty, int want_subsystem,
1963     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1964     dispatch_fn *subsys_repl)
1965 {
1966         int len;
1967         Channel *c = NULL;
1968
1969         debug2("%s: id %d", __func__, id);
1970
1971         if ((c = channel_lookup(id)) == NULL)
1972                 fatal("client_session2_setup: channel %d: unknown channel", id);
1973
1974         if (want_tty) {
1975                 struct winsize ws;
1976                 struct termios tio;
1977
1978                 /* Store window size in the packet. */
1979                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1980                         memset(&ws, 0, sizeof(ws));
1981
1982                 channel_request_start(id, "pty-req", 0);
1983                 packet_put_cstring(term != NULL ? term : "");
1984                 packet_put_int((u_int)ws.ws_col);
1985                 packet_put_int((u_int)ws.ws_row);
1986                 packet_put_int((u_int)ws.ws_xpixel);
1987                 packet_put_int((u_int)ws.ws_ypixel);
1988                 tio = get_saved_tio();
1989                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1990                 packet_send();
1991                 /* XXX wait for reply */
1992                 c->client_tty = 1;
1993         }
1994
1995         /* Transfer any environment variables from client to server */
1996         if (options.num_send_env != 0 && env != NULL) {
1997                 int i, j, matched;
1998                 char *name, *val;
1999
2000                 debug("Sending environment.");
2001                 for (i = 0; env[i] != NULL; i++) {
2002                         /* Split */
2003                         name = xstrdup(env[i]);
2004                         if ((val = strchr(name, '=')) == NULL) {
2005                                 xfree(name);
2006                                 continue;
2007                         }
2008                         *val++ = '\0';
2009
2010                         matched = 0;
2011                         for (j = 0; j < options.num_send_env; j++) {
2012                                 if (match_pattern(name, options.send_env[j])) {
2013                                         matched = 1;
2014                                         break;
2015                                 }
2016                         }
2017                         if (!matched) {
2018                                 debug3("Ignored env %s", name);
2019                                 xfree(name);
2020                                 continue;
2021                         }
2022
2023                         debug("Sending env %s = %s", name, val);
2024                         channel_request_start(id, "env", 0);
2025                         packet_put_cstring(name);
2026                         packet_put_cstring(val);
2027                         packet_send();
2028                         xfree(name);
2029                 }
2030         }
2031
2032         len = buffer_len(cmd);
2033         if (len > 0) {
2034                 if (len > 900)
2035                         len = 900;
2036                 if (want_subsystem) {
2037                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
2038                         channel_request_start(id, "subsystem", subsys_repl != NULL);
2039                         if (subsys_repl != NULL) {
2040                                 /* register callback for reply */
2041                                 /* XXX we assume that client_loop has already been called */
2042                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
2043                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
2044                         }
2045                 } else {
2046                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
2047                         channel_request_start(id, "exec", 0);
2048                 }
2049                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2050                 packet_send();
2051         } else {
2052                 channel_request_start(id, "shell", 0);
2053                 packet_send();
2054         }
2055 }
2056
2057 static void
2058 client_init_dispatch_20(void)
2059 {
2060         dispatch_init(&dispatch_protocol_error);
2061
2062         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2063         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2064         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2065         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2066         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2067         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2068         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2069         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2070         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2071         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2072
2073         /* rekeying */
2074         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2075
2076         /* global request reply messages */
2077         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2078         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2079 }
2080 static void
2081 client_init_dispatch_13(void)
2082 {
2083         dispatch_init(NULL);
2084         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2085         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2086         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2087         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2088         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2089         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2090         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2091         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2092         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2093
2094         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2095             &client_input_agent_open : &deny_input_open);
2096         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2097             &x11_input_open : &deny_input_open);
2098 }
2099 static void
2100 client_init_dispatch_15(void)
2101 {
2102         client_init_dispatch_13();
2103         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2104         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2105 }
2106 static void
2107 client_init_dispatch(void)
2108 {
2109         if (compat20)
2110                 client_init_dispatch_20();
2111         else if (compat13)
2112                 client_init_dispatch_13();
2113         else
2114                 client_init_dispatch_15();
2115 }
2116
2117 /* client specific fatal cleanup */
2118 void
2119 cleanup_exit(int i)
2120 {
2121         leave_raw_mode();
2122         leave_non_blocking();
2123         if (options.control_path != NULL && control_fd != -1)
2124                 unlink(options.control_path);
2125         _exit(i);
2126 }