openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.175 2006/08/03 03:34:42 deraadt 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 static int server_alive_timeouts = 0;
 161
 162 static void client_init_dispatch(void);
 163 int     session_ident = -1;
 164
 165 struct confirm_ctx {
 166         int want_tty;
 167         int want_subsys;
 168         int want_x_fwd;
 169         int want_agent_fwd;
 170         Buffer cmd;
 171         char *term;
 172         struct termios tio;
 173         char **env;
 174 };
 175
 176 /*XXX*/
 177 extern Kex *xxx_kex;
 178
 179 void ssh_process_session2_setup(int, int, int, Buffer *);
 180
 181 /* Restores stdin to blocking mode. */
 182
 183 static void
 184 leave_non_blocking(void)
 185 {
 186         if (in_non_blocking_mode) {
 187                 unset_nonblock(fileno(stdin));
 188                 in_non_blocking_mode = 0;
 189         }
 190 }
 191
 192 /* Puts stdin terminal in non-blocking mode. */
 193
 194 static void
 195 enter_non_blocking(void)
 196 {
 197         in_non_blocking_mode = 1;
 198         set_nonblock(fileno(stdin));
 199 }
 200
 201 /*
 202  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 203  * flag indicating that the window has changed.
 204  */
 205 /*ARGSUSED */
 206 static void
 207 window_change_handler(int sig)
 208 {
 209         received_window_change_signal = 1;
 210         signal(SIGWINCH, window_change_handler);
 211 }
 212
 213 /*
 214  * Signal handler for signals that cause the program to terminate.  These
 215  * signals must be trapped to restore terminal modes.
 216  */
 217 /*ARGSUSED */
 218 static void
 219 signal_handler(int sig)
 220 {
 221         received_signal = sig;
 222         quit_pending = 1;
 223 }
 224
 225 /*
 226  * Returns current time in seconds from Jan 1, 1970 with the maximum
 227  * available resolution.
 228  */
 229
 230 static double
 231 get_current_time(void)
 232 {
 233         struct timeval tv;
 234         gettimeofday(&tv, NULL);
 235         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 236 }
 237
 238 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 239 void
 240 client_x11_get_proto(const char *display, const char *xauth_path,
 241     u_int trusted, char **_proto, char **_data)
 242 {
 243         char cmd[1024];
 244         char line[512];
 245         char xdisplay[512];
 246         static char proto[512], data[512];
 247         FILE *f;
 248         int got_data = 0, generated = 0, do_unlink = 0, i;
 249         char *xauthdir, *xauthfile;
 250         struct stat st;
 251
 252         xauthdir = xauthfile = NULL;
 253         *_proto = proto;
 254         *_data = data;
 255         proto[0] = data[0] = '\0';
 256
 257         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 258                 debug("No xauth program.");
 259         } else {
 260                 if (display == NULL) {
 261                         debug("x11_get_proto: DISPLAY not set");
 262                         return;
 263                 }
 264                 /*
 265                  * Handle FamilyLocal case where $DISPLAY does
 266                  * not match an authorization entry.  For this we
 267                  * just try "xauth list unix:displaynum.screennum".
 268                  * XXX: "localhost" match to determine FamilyLocal
 269                  *      is not perfect.
 270                  */
 271                 if (strncmp(display, "localhost:", 10) == 0) {
 272                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 273                             display + 10);
 274                         display = xdisplay;
 275                 }
 276                 if (trusted == 0) {
 277                         xauthdir = xmalloc(MAXPATHLEN);
 278                         xauthfile = xmalloc(MAXPATHLEN);
 279                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 280                         if (mkdtemp(xauthdir) != NULL) {
 281                                 do_unlink = 1;
 282                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 283                                     xauthdir);
 284                                 snprintf(cmd, sizeof(cmd),
 285                                     "%s -f %s generate %s " SSH_X11_PROTO
 286                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 287                                     xauth_path, xauthfile, display);
 288                                 debug2("x11_get_proto: %s", cmd);
 289                                 if (system(cmd) == 0)
 290                                         generated = 1;
 291                         }
 292                 }
 293                 snprintf(cmd, sizeof(cmd),
 294                     "%s %s%s list %s 2>" _PATH_DEVNULL,
 295                     xauth_path,
 296                     generated ? "-f " : "" ,
 297                     generated ? xauthfile : "",
 298                     display);
 299                 debug2("x11_get_proto: %s", cmd);
 300                 f = popen(cmd, "r");
 301                 if (f && fgets(line, sizeof(line), f) &&
 302                     sscanf(line, "%*s %511s %511s", proto, data) == 2)
 303                         got_data = 1;
 304                 if (f)
 305                         pclose(f);
 306         }
 307
 308         if (do_unlink) {
 309                 unlink(xauthfile);
 310                 rmdir(xauthdir);
 311         }
 312         if (xauthdir)
 313                 xfree(xauthdir);
 314         if (xauthfile)
 315                 xfree(xauthfile);
 316
 317         /*
 318          * If we didn't get authentication data, just make up some
 319          * data.  The forwarding code will check the validity of the
 320          * response anyway, and substitute this data.  The X11
 321          * server, however, will ignore this fake data and use
 322          * whatever authentication mechanisms it was using otherwise
 323          * for the local connection.
 324          */
 325         if (!got_data) {
 326                 u_int32_t rnd = 0;
 327
 328                 logit("Warning: No xauth data; "
 329                     "using fake authentication data for X11 forwarding.");
 330                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 331                 for (i = 0; i < 16; i++) {
 332                         if (i % 4 == 0)
 333                                 rnd = arc4random();
 334                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 335                             rnd & 0xff);
 336                         rnd >>= 8;
 337                 }
 338         }
 339 }
 340
 341 /*
 342  * This is called when the interactive is entered.  This checks if there is
 343  * an EOF coming on stdin.  We must check this explicitly, as select() does
 344  * not appear to wake up when redirecting from /dev/null.
 345  */
 346
 347 static void
 348 client_check_initial_eof_on_stdin(void)
 349 {
 350         int len;
 351         char buf[1];
 352
 353         /*
 354          * If standard input is to be "redirected from /dev/null", we simply
 355          * mark that we have seen an EOF and send an EOF message to the
 356          * server. Otherwise, we try to read a single character; it appears
 357          * that for some files, such /dev/null, select() never wakes up for
 358          * read for this descriptor, which means that we never get EOF.  This
 359          * way we will get the EOF if stdin comes from /dev/null or similar.
 360          */
 361         if (stdin_null_flag) {
 362                 /* Fake EOF on stdin. */
 363                 debug("Sending eof.");
 364                 stdin_eof = 1;
 365                 packet_start(SSH_CMSG_EOF);
 366                 packet_send();
 367         } else {
 368                 enter_non_blocking();
 369
 370                 /* Check for immediate EOF on stdin. */
 371                 len = read(fileno(stdin), buf, 1);
 372                 if (len == 0) {
 373                         /* EOF.  Record that we have seen it and send EOF to server. */
 374                         debug("Sending eof.");
 375                         stdin_eof = 1;
 376                         packet_start(SSH_CMSG_EOF);
 377                         packet_send();
 378                 } else if (len > 0) {
 379                         /*
 380                          * Got data.  We must store the data in the buffer,
 381                          * and also process it as an escape character if
 382                          * appropriate.
 383                          */
 384                         if ((u_char) buf[0] == escape_char)
 385                                 escape_pending = 1;
 386                         else
 387                                 buffer_append(&stdin_buffer, buf, 1);
 388                 }
 389                 leave_non_blocking();
 390         }
 391 }
 392
 393
 394 /*
 395  * Make packets from buffered stdin data, and buffer them for sending to the
 396  * connection.
 397  */
 398
 399 static void
 400 client_make_packets_from_stdin_data(void)
 401 {
 402         u_int len;
 403
 404         /* Send buffered stdin data to the server. */
 405         while (buffer_len(&stdin_buffer) > 0 &&
 406             packet_not_very_much_data_to_write()) {
 407                 len = buffer_len(&stdin_buffer);
 408                 /* Keep the packets at reasonable size. */
 409                 if (len > packet_get_maxsize())
 410                         len = packet_get_maxsize();
 411                 packet_start(SSH_CMSG_STDIN_DATA);
 412                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 413                 packet_send();
 414                 buffer_consume(&stdin_buffer, len);
 415                 stdin_bytes += len;
 416                 /* If we have a pending EOF, send it now. */
 417                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 418                         packet_start(SSH_CMSG_EOF);
 419                         packet_send();
 420                 }
 421         }
 422 }
 423
 424 /*
 425  * Checks if the client window has changed, and sends a packet about it to
 426  * the server if so.  The actual change is detected elsewhere (by a software
 427  * interrupt on Unix); this just checks the flag and sends a message if
 428  * appropriate.
 429  */
 430
 431 static void
 432 client_check_window_change(void)
 433 {
 434         struct winsize ws;
 435
 436         if (! received_window_change_signal)
 437                 return;
 438         /** XXX race */
 439         received_window_change_signal = 0;
 440
 441         debug2("client_check_window_change: changed");
 442
 443         if (compat20) {
 444                 channel_send_window_changes();
 445         } else {
 446                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 447                         return;
 448                 packet_start(SSH_CMSG_WINDOW_SIZE);
 449                 packet_put_int((u_int)ws.ws_row);
 450                 packet_put_int((u_int)ws.ws_col);
 451                 packet_put_int((u_int)ws.ws_xpixel);
 452                 packet_put_int((u_int)ws.ws_ypixel);
 453                 packet_send();
 454         }
 455 }
 456
 457 static void
 458 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 459 {
 460         server_alive_timeouts = 0;
 461         client_global_request_reply_fwd(type, seq, ctxt);
 462 }
 463
 464 static void
 465 server_alive_check(void)
 466 {
 467         if (++server_alive_timeouts > options.server_alive_count_max)
 468                 packet_disconnect("Timeout, server not responding.");
 469         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 470         packet_put_cstring("keepalive@openssh.com");
 471         packet_put_char(1);     /* boolean: want reply */
 472         packet_send();
 473 }
 474
 475 /*
 476  * Waits until the client can do something (some data becomes available on
 477  * one of the file descriptors).
 478  */
 479 static void
 480 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 481     int *maxfdp, u_int *nallocp, int rekeying)
 482 {
 483         struct timeval tv, *tvp;
 484         int ret;
 485
 486         /* Add any selections by the channel mechanism. */
 487         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 488
 489         if (!compat20) {
 490                 /* Read from the connection, unless our buffers are full. */
 491                 if (buffer_len(&stdout_buffer) < buffer_high &&
 492                     buffer_len(&stderr_buffer) < buffer_high &&
 493                     channel_not_very_much_buffered_data())
 494                         FD_SET(connection_in, *readsetp);
 495                 /*
 496                  * Read from stdin, unless we have seen EOF or have very much
 497                  * buffered data to send to the server.
 498                  */
 499                 if (!stdin_eof && packet_not_very_much_data_to_write())
 500                         FD_SET(fileno(stdin), *readsetp);
 501
 502                 /* Select stdout/stderr if have data in buffer. */
 503                 if (buffer_len(&stdout_buffer) > 0)
 504                         FD_SET(fileno(stdout), *writesetp);
 505                 if (buffer_len(&stderr_buffer) > 0)
 506                         FD_SET(fileno(stderr), *writesetp);
 507         } else {
 508                 /* channel_prepare_select could have closed the last channel */
 509                 if (session_closed && !channel_still_open() &&
 510                     !packet_have_data_to_write()) {
 511                         /* clear mask since we did not call select() */
 512                         memset(*readsetp, 0, *nallocp);
 513                         memset(*writesetp, 0, *nallocp);
 514                         return;
 515                 } else {
 516                         FD_SET(connection_in, *readsetp);
 517                 }
 518         }
 519
 520         /* Select server connection if have data to write to the server. */
 521         if (packet_have_data_to_write())
 522                 FD_SET(connection_out, *writesetp);
 523
 524         if (control_fd != -1)
 525                 FD_SET(control_fd, *readsetp);
 526
 527         /*
 528          * Wait for something to happen.  This will suspend the process until
 529          * some selected descriptor can be read, written, or has some other
 530          * event pending.
 531          */
 532
 533         if (options.server_alive_interval == 0 || !compat20)
 534                 tvp = NULL;
 535         else {
 536                 tv.tv_sec = options.server_alive_interval;
 537                 tv.tv_usec = 0;
 538                 tvp = &tv;
 539         }
 540         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 541         if (ret < 0) {
 542                 char buf[100];
 543
 544                 /*
 545                  * We have to clear the select masks, because we return.
 546                  * We have to return, because the mainloop checks for the flags
 547                  * set by the signal handlers.
 548                  */
 549                 memset(*readsetp, 0, *nallocp);
 550                 memset(*writesetp, 0, *nallocp);
 551
 552                 if (errno == EINTR)
 553                         return;
 554                 /* Note: we might still have data in the buffers. */
 555                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 556                 buffer_append(&stderr_buffer, buf, strlen(buf));
 557                 quit_pending = 1;
 558         } else if (ret == 0)
 559                 server_alive_check();
 560 }
 561
 562 static void
 563 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 564 {
 565         /* Flush stdout and stderr buffers. */
 566         if (buffer_len(bout) > 0)
 567                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 568         if (buffer_len(berr) > 0)
 569                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 570
 571         leave_raw_mode();
 572
 573         /*
 574          * Free (and clear) the buffer to reduce the amount of data that gets
 575          * written to swap.
 576          */
 577         buffer_free(bin);
 578         buffer_free(bout);
 579         buffer_free(berr);
 580
 581         /* Send the suspend signal to the program itself. */
 582         kill(getpid(), SIGTSTP);
 583
 584         /* Reset window sizes in case they have changed */
 585         received_window_change_signal = 1;
 586
 587         /* OK, we have been continued by the user. Reinitialize buffers. */
 588         buffer_init(bin);
 589         buffer_init(bout);
 590         buffer_init(berr);
 591
 592         enter_raw_mode();
 593 }
 594
 595 static void
 596 client_process_net_input(fd_set *readset)
 597 {
 598         int len;
 599         char buf[8192];
 600
 601         /*
 602          * Read input from the server, and add any such data to the buffer of
 603          * the packet subsystem.
 604          */
 605         if (FD_ISSET(connection_in, readset)) {
 606                 /* Read as much as possible. */
 607                 len = read(connection_in, buf, sizeof(buf));
 608                 if (len == 0) {
 609                         /* Received EOF.  The remote host has closed the connection. */
 610                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 611                                  host);
 612                         buffer_append(&stderr_buffer, buf, strlen(buf));
 613                         quit_pending = 1;
 614                         return;
 615                 }
 616                 /*
 617                  * There is a kernel bug on Solaris that causes select to
 618                  * sometimes wake up even though there is no data available.
 619                  */
 620                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 621                         len = 0;
 622
 623                 if (len < 0) {
 624                         /* An error has encountered.  Perhaps there is a network problem. */
 625                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 626                                  host, strerror(errno));
 627                         buffer_append(&stderr_buffer, buf, strlen(buf));
 628                         quit_pending = 1;
 629                         return;
 630                 }
 631                 packet_process_incoming(buf, len);
 632         }
 633 }
 634
 635 static void
 636 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 637 {
 638         int id;
 639         Channel *c;
 640
 641         id = packet_get_int();
 642         packet_check_eom();
 643
 644         if ((c = channel_lookup(id)) == NULL) {
 645                 error("%s: no channel for id %d", __func__, id);
 646                 return;
 647         }
 648
 649         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 650                 debug2("Request suceeded on channel %d", id);
 651         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 652                 error("Request failed on channel %d", id);
 653                 channel_free(c);
 654         }
 655 }
 656
 657 static void
 658 client_extra_session2_setup(int id, void *arg)
 659 {
 660         struct confirm_ctx *cctx = arg;
 661         const char *display;
 662         Channel *c;
 663         int i;
 664
 665         if (cctx == NULL)
 666                 fatal("%s: cctx == NULL", __func__);
 667         if ((c = channel_lookup(id)) == NULL)
 668                 fatal("%s: no channel for id %d", __func__, id);
 669
 670         display = getenv("DISPLAY");
 671         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 672                 char *proto, *data;
 673                 /* Get reasonable local authentication information. */
 674                 client_x11_get_proto(display, options.xauth_location,
 675                     options.forward_x11_trusted, &proto, &data);
 676                 /* Request forwarding with authentication spoofing. */
 677                 debug("Requesting X11 forwarding with authentication spoofing.");
 678                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 679                 /* XXX wait for reply */
 680         }
 681
 682         if (cctx->want_agent_fwd && options.forward_agent) {
 683                 debug("Requesting authentication agent forwarding.");
 684                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 685                 packet_send();
 686         }
 687
 688         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 689             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 690             client_subsystem_reply);
 691
 692         c->confirm_ctx = NULL;
 693         buffer_free(&cctx->cmd);
 694         xfree(cctx->term);
 695         if (cctx->env != NULL) {
 696                 for (i = 0; cctx->env[i] != NULL; i++)
 697                         xfree(cctx->env[i]);
 698                 xfree(cctx->env);
 699         }
 700         xfree(cctx);
 701 }
 702
 703 static void
 704 client_process_control(fd_set *readset)
 705 {
 706         Buffer m;
 707         Channel *c;
 708         int client_fd, new_fd[3], ver, allowed;
 709         socklen_t addrlen;
 710         struct sockaddr_storage addr;
 711         struct confirm_ctx *cctx;
 712         char *cmd;
 713         u_int i, len, env_len, command, flags;
 714         uid_t euid;
 715         gid_t egid;
 716         int listen_port = 0;
 717         int connect_port = 0;
 718         char * listen_host = NULL;
 719         char * connect_host = NULL;
 720
 721         /*
 722          * Accept connection on control socket
 723          */
 724         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 725                 return;
 726
 727         memset(&addr, 0, sizeof(addr));
 728         addrlen = sizeof(addr);
 729         if ((client_fd = accept(control_fd,
 730             (struct sockaddr*)&addr, &addrlen)) == -1) {
 731                 error("%s accept: %s", __func__, strerror(errno));
 732                 return;
 733         }
 734
 735         if (getpeereid(client_fd, &euid, &egid) < 0) {
 736                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 737                 close(client_fd);
 738                 return;
 739         }
 740         if ((euid != 0) && (getuid() != euid)) {
 741                 error("control mode uid mismatch: peer euid %u != uid %u",
 742                     (u_int) euid, (u_int) getuid());
 743                 close(client_fd);
 744                 return;
 745         }
 746
 747         unset_nonblock(client_fd);
 748
 749         /* Read command */
 750         buffer_init(&m);
 751         if (ssh_msg_recv(client_fd, &m) == -1) {
 752                 error("%s: client msg_recv failed", __func__);
 753                 close(client_fd);
 754                 buffer_free(&m);
 755                 return;
 756         }
 757         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 758                 error("%s: wrong client version %d", __func__, ver);
 759                 buffer_free(&m);
 760                 close(client_fd);
 761                 return;
 762         }
 763
 764         allowed = 1;
 765         command = buffer_get_int(&m);
 766         flags = buffer_get_int(&m);
 767
 768         if (SSHMUX_FLAG_PORTFORWARD & flags)
 769         {
 770                 listen_host = buffer_get_string(&m,NULL);
 771                 listen_port = buffer_get_int(&m);
 772                 connect_host = buffer_get_string(&m,NULL);
 773                 connect_port = 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         if (allowed && (SSHMUX_FLAG_PORTFORWARD & flags) && listen_host && connect_host)
 815         {
 816                 int ret;
 817                 Forward * fwd;
 818
 819                 fwd = &options.local_forwards[options.num_local_forwards++];
 820                 fwd->listen_host = xstrdup(listen_host);
 821                 fwd->listen_port = listen_port;
 822                 fwd->connect_host = xstrdup(connect_host);
 823                 fwd->connect_port = connect_port;
 824                 ret = channel_setup_local_fwd_listener(
 825                         options.local_forwards[options.num_local_forwards-1].listen_host,
 826                         options.local_forwards[options.num_local_forwards-1].listen_port,
 827                         options.local_forwards[options.num_local_forwards-1].connect_host,
 828                         options.local_forwards[options.num_local_forwards-1].connect_port,
 829                         options.gateway_ports, options.hpn_disabled, options.hpn_buffer_size);
 830
 831         }
 832
 833
 834         if (listen_host)
 835                 xfree(listen_host);
 836         if (connect_host)
 837                 xfree(connect_host);
 838
 839         /* Reply for SSHMUX_COMMAND_OPEN */
 840         buffer_clear(&m);
 841         buffer_put_int(&m, allowed);
 842         buffer_put_int(&m, getpid());
 843         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 844                 error("%s: client msg_send failed", __func__);
 845                 close(client_fd);
 846                 buffer_free(&m);
 847                 return;
 848         }
 849
 850         if (!allowed) {
 851                 error("Refused control connection");
 852                 close(client_fd);
 853                 buffer_free(&m);
 854                 return;
 855         }
 856
 857         buffer_clear(&m);
 858         if (ssh_msg_recv(client_fd, &m) == -1) {
 859                 error("%s: client msg_recv failed", __func__);
 860                 close(client_fd);
 861                 buffer_free(&m);
 862                 return;
 863         }
 864         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 865                 error("%s: wrong client version %d", __func__, ver);
 866                 buffer_free(&m);
 867                 close(client_fd);
 868                 return;
 869         }
 870
 871         cctx = xcalloc(1, sizeof(*cctx));
 872         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 873         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 874         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 875         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 876         cctx->term = buffer_get_string(&m, &len);
 877
 878         cmd = buffer_get_string(&m, &len);
 879         buffer_init(&cctx->cmd);
 880         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 881
 882         env_len = buffer_get_int(&m);
 883         env_len = MIN(env_len, 4096);
 884         debug3("%s: receiving %d env vars", __func__, env_len);
 885         if (env_len != 0) {
 886                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 887                 for (i = 0; i < env_len; i++)
 888                         cctx->env[i] = buffer_get_string(&m, &len);
 889                 cctx->env[i] = NULL;
 890         }
 891
 892         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 893             cctx->want_tty, cctx->want_subsys, cmd);
 894         xfree(cmd);
 895
 896         /* Gather fds from client */
 897         new_fd[0] = mm_receive_fd(client_fd);
 898         new_fd[1] = mm_receive_fd(client_fd);
 899         new_fd[2] = mm_receive_fd(client_fd);
 900
 901         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 902             new_fd[0], new_fd[1], new_fd[2]);
 903
 904         /* Try to pick up ttymodes from client before it goes raw */
 905         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 906                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 907
 908         /* This roundtrip is just for synchronisation of ttymodes */
 909         buffer_clear(&m);
 910         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 911                 error("%s: client msg_send failed", __func__);
 912                 close(client_fd);
 913                 close(new_fd[0]);
 914                 close(new_fd[1]);
 915                 close(new_fd[2]);
 916                 buffer_free(&m);
 917                 xfree(cctx->term);
 918                 if (env_len != 0) {
 919                         for (i = 0; i < env_len; i++)
 920                                 xfree(cctx->env[i]);
 921                         xfree(cctx->env);
 922                 }
 923                 return;
 924         }
 925         buffer_free(&m);
 926
 927         /* enable nonblocking unless tty */
 928         if (!isatty(new_fd[0]))
 929                 set_nonblock(new_fd[0]);
 930         if (!isatty(new_fd[1]))
 931                 set_nonblock(new_fd[1]);
 932         if (!isatty(new_fd[2]))
 933                 set_nonblock(new_fd[2]);
 934
 935         set_nonblock(client_fd);
 936
 937         if (options.hpn_disabled)
 938                 c = channel_new("session", SSH_CHANNEL_OPENING,
 939                     new_fd[0], new_fd[1], new_fd[2],
 940                     CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
 941                     CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 942         else
 943                 c = channel_new("session", SSH_CHANNEL_OPENING,
 944                     new_fd[0], new_fd[1], new_fd[2],
 945                     options.hpn_buffer_size, CHAN_SES_PACKET_DEFAULT,
 946                     CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 947         /* XXX */
 948         c->ctl_fd = client_fd;
 949
 950         debug3("%s: channel_new: %d", __func__, c->self);
 951
 952         channel_send_open(c->self);
 953         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 954 }
 955
 956 static void
 957 process_cmdline(void)
 958 {
 959         void (*handler)(int);
 960         char *s, *cmd, *cancel_host;
 961         int delete = 0;
 962         int local = 0;
 963         u_short cancel_port;
 964         Forward fwd;
 965
 966         leave_raw_mode();
 967         handler = signal(SIGINT, SIG_IGN);
 968         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 969         if (s == NULL)
 970                 goto out;
 971         while (*s && isspace(*s))
 972                 s++;
 973         if (*s == '-')
 974                 s++;    /* Skip cmdline '-', if any */
 975         if (*s == '\0')
 976                 goto out;
 977
 978         if (*s == 'h' || *s == 'H' || *s == '?') {
 979                 logit("Commands:");
 980                 logit("      -L[bind_address:]port:host:hostport    "
 981                     "Request local forward");
 982                 logit("      -R[bind_address:]port:host:hostport    "
 983                     "Request remote forward");
 984                 logit("      -KR[bind_address:]port                 "
 985                     "Cancel remote forward");
 986                 if (!options.permit_local_command)
 987                         goto out;
 988                 logit("      !args                                  "
 989                     "Execute local command");
 990                 goto out;
 991         }
 992
 993         if (*s == '!' && options.permit_local_command) {
 994                 s++;
 995                 ssh_local_cmd(s);
 996                 goto out;
 997         }
 998
 999         if (*s == 'K') {
1000                 delete = 1;
1001                 s++;
1002         }
1003         if (*s != 'L' && *s != 'R') {
1004                 logit("Invalid command.");
1005                 goto out;
1006         }
1007         if (*s == 'L')
1008                 local = 1;
1009         if (local && delete) {
1010                 logit("Not supported.");
1011                 goto out;
1012         }
1013         if ((!local || delete) && !compat20) {
1014                 logit("Not supported for SSH protocol version 1.");
1015                 goto out;
1016         }
1017
1018         s++;
1019         while (*s && isspace(*s))
1020                 s++;
1021
1022         if (delete) {
1023                 cancel_port = 0;
1024                 cancel_host = hpdelim(&s);      /* may be NULL */
1025                 if (s != NULL) {
1026                         cancel_port = a2port(s);
1027                         cancel_host = cleanhostname(cancel_host);
1028                 } else {
1029                         cancel_port = a2port(cancel_host);
1030                         cancel_host = NULL;
1031                 }
1032                 if (cancel_port == 0) {
1033                         logit("Bad forwarding close port");
1034                         goto out;
1035                 }
1036                 channel_request_rforward_cancel(cancel_host, cancel_port);
1037         } else {
1038                 if (!parse_forward(&fwd, s)) {
1039                         logit("Bad forwarding specification.");
1040                         goto out;
1041                 }
1042                 if (local) {
1043                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1044                             fwd.listen_port, fwd.connect_host,
1045                             fwd.connect_port, options.gateway_ports,
1046                             options.hpn_disabled, options.hpn_buffer_size) < 0) {
1047                                 logit("Port forwarding failed.");
1048                                 goto out;
1049                         }
1050                 } else {
1051                         if (channel_request_remote_forwarding(fwd.listen_host,
1052                             fwd.listen_port, fwd.connect_host,
1053                             fwd.connect_port) < 0) {
1054                                 logit("Port forwarding failed.");
1055                                 goto out;
1056                         }
1057                 }
1058
1059                 logit("Forwarding port.");
1060         }
1061
1062 out:
1063         signal(SIGINT, handler);
1064         enter_raw_mode();
1065         if (cmd)
1066                 xfree(cmd);
1067 }
1068
1069 /* process the characters one by one */
1070 static int
1071 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1072 {
1073         char string[1024];
1074         pid_t pid;
1075         int bytes = 0;
1076         u_int i;
1077         u_char ch;
1078         char *s;
1079
1080         if (len <= 0)
1081                 return (0);
1082
1083         for (i = 0; i < (u_int)len; i++) {
1084                 /* Get one character at a time. */
1085                 ch = buf[i];
1086
1087                 if (escape_pending) {
1088                         /* We have previously seen an escape character. */
1089                         /* Clear the flag now. */
1090                         escape_pending = 0;
1091
1092                         /* Process the escaped character. */
1093                         switch (ch) {
1094                         case '.':
1095                                 /* Terminate the connection. */
1096                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1097                                 buffer_append(berr, string, strlen(string));
1098
1099                                 quit_pending = 1;
1100                                 return -1;
1101
1102                         case 'Z' - 64:
1103                                 /* Suspend the program. */
1104                                 /* Print a message to that effect to the user. */
1105                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1106                                 buffer_append(berr, string, strlen(string));
1107
1108                                 /* Restore terminal modes and suspend. */
1109                                 client_suspend_self(bin, bout, berr);
1110
1111                                 /* We have been continued. */
1112                                 continue;
1113
1114                         case 'B':
1115                                 if (compat20) {
1116                                         snprintf(string, sizeof string,
1117                                             "%cB\r\n", escape_char);
1118                                         buffer_append(berr, string,
1119                                             strlen(string));
1120                                         channel_request_start(session_ident,
1121                                             "break", 0);
1122                                         packet_put_int(1000);
1123                                         packet_send();
1124                                 }
1125                                 continue;
1126
1127                         case 'R':
1128                                 if (compat20) {
1129                                         if (datafellows & SSH_BUG_NOREKEY)
1130                                                 logit("Server does not support re-keying");
1131                                         else
1132                                                 need_rekeying = 1;
1133                                 }
1134                                 continue;
1135
1136                         case '&':
1137                                 /*
1138                                  * Detach the program (continue to serve connections,
1139                                  * but put in background and no more new connections).
1140                                  */
1141                                 /* Restore tty modes. */
1142                                 leave_raw_mode();
1143
1144                                 /* Stop listening for new connections. */
1145                                 channel_stop_listening();
1146
1147                                 snprintf(string, sizeof string,
1148                                     "%c& [backgrounded]\n", escape_char);
1149                                 buffer_append(berr, string, strlen(string));
1150
1151                                 /* Fork into background. */
1152                                 pid = fork();
1153                                 if (pid < 0) {
1154                                         error("fork: %.100s", strerror(errno));
1155                                         continue;
1156                                 }
1157                                 if (pid != 0) { /* This is the parent. */
1158                                         /* The parent just exits. */
1159                                         exit(0);
1160                                 }
1161                                 /* The child continues serving connections. */
1162                                 if (compat20) {
1163                                         buffer_append(bin, "\004", 1);
1164                                         /* fake EOF on stdin */
1165                                         return -1;
1166                                 } else if (!stdin_eof) {
1167                                         /*
1168                                          * Sending SSH_CMSG_EOF alone does not always appear
1169                                          * to be enough.  So we try to send an EOF character
1170                                          * first.
1171                                          */
1172                                         packet_start(SSH_CMSG_STDIN_DATA);
1173                                         packet_put_string("\004", 1);
1174                                         packet_send();
1175                                         /* Close stdin. */
1176                                         stdin_eof = 1;
1177                                         if (buffer_len(bin) == 0) {
1178                                                 packet_start(SSH_CMSG_EOF);
1179                                                 packet_send();
1180                                         }
1181                                 }
1182                                 continue;
1183
1184                         case '?':
1185                                 snprintf(string, sizeof string,
1186 "%c?\r\n\
1187 Supported escape sequences:\r\n\
1188 %c.  - terminate connection\r\n\
1189 %cB  - send a BREAK to the remote system\r\n\
1190 %cC  - open a command line\r\n\
1191 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1192 %c^Z - suspend ssh\r\n\
1193 %c#  - list forwarded connections\r\n\
1194 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1195 %c?  - this message\r\n\
1196 %c%c  - send the escape character by typing it twice\r\n\
1197 (Note that escapes are only recognized immediately after newline.)\r\n",
1198                                     escape_char, escape_char, escape_char, escape_char,
1199                                     escape_char, escape_char, escape_char, escape_char,
1200                                     escape_char, escape_char, escape_char);
1201                                 buffer_append(berr, string, strlen(string));
1202                                 continue;
1203
1204                         case '#':
1205                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1206                                 buffer_append(berr, string, strlen(string));
1207                                 s = channel_open_message();
1208                                 buffer_append(berr, s, strlen(s));
1209                                 xfree(s);
1210                                 continue;
1211
1212                         case 'C':
1213                                 process_cmdline();
1214                                 continue;
1215
1216                         default:
1217                                 if (ch != escape_char) {
1218                                         buffer_put_char(bin, escape_char);
1219                                         bytes++;
1220                                 }
1221                                 /* Escaped characters fall through here */
1222                                 break;
1223                         }
1224                 } else {
1225                         /*
1226                          * The previous character was not an escape char. Check if this
1227                          * is an escape.
1228                          */
1229                         if (last_was_cr && ch == escape_char) {
1230                                 /* It is. Set the flag and continue to next character. */
1231                                 escape_pending = 1;
1232                                 continue;
1233                         }
1234                 }
1235
1236                 /*
1237                  * Normal character.  Record whether it was a newline,
1238                  * and append it to the buffer.
1239                  */
1240                 last_was_cr = (ch == '\r' || ch == '\n');
1241                 buffer_put_char(bin, ch);
1242                 bytes++;
1243         }
1244         return bytes;
1245 }
1246
1247 static void
1248 client_process_input(fd_set *readset)
1249 {
1250         int len;
1251         char buf[8192];
1252
1253         /* Read input from stdin. */
1254         if (FD_ISSET(fileno(stdin), readset)) {
1255                 /* Read as much as possible. */
1256                 len = read(fileno(stdin), buf, sizeof(buf));
1257                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1258                         return;         /* we'll try again later */
1259                 if (len <= 0) {
1260                         /*
1261                          * Received EOF or error.  They are treated
1262                          * similarly, except that an error message is printed
1263                          * if it was an error condition.
1264                          */
1265                         if (len < 0) {
1266                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1267                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1268                         }
1269                         /* Mark that we have seen EOF. */
1270                         stdin_eof = 1;
1271                         /*
1272                          * Send an EOF message to the server unless there is
1273                          * data in the buffer.  If there is data in the
1274                          * buffer, no message will be sent now.  Code
1275                          * elsewhere will send the EOF when the buffer
1276                          * becomes empty if stdin_eof is set.
1277                          */
1278                         if (buffer_len(&stdin_buffer) == 0) {
1279                                 packet_start(SSH_CMSG_EOF);
1280                                 packet_send();
1281                         }
1282                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1283                         /*
1284                          * Normal successful read, and no escape character.
1285                          * Just append the data to buffer.
1286                          */
1287                         buffer_append(&stdin_buffer, buf, len);
1288                 } else {
1289                         /*
1290                          * Normal, successful read.  But we have an escape character
1291                          * and have to process the characters one by one.
1292                          */
1293                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1294                             &stderr_buffer, buf, len) == -1)
1295                                 return;
1296                 }
1297         }
1298 }
1299
1300 static void
1301 client_process_output(fd_set *writeset)
1302 {
1303         int len;
1304         char buf[100];
1305
1306         /* Write buffered output to stdout. */
1307         if (FD_ISSET(fileno(stdout), writeset)) {
1308                 /* Write as much data as possible. */
1309                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1310                     buffer_len(&stdout_buffer));
1311                 if (len <= 0) {
1312                         if (errno == EINTR || errno == EAGAIN)
1313                                 len = 0;
1314                         else {
1315                                 /*
1316                                  * An error or EOF was encountered.  Put an
1317                                  * error message to stderr buffer.
1318                                  */
1319                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1320                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1321                                 quit_pending = 1;
1322                                 return;
1323                         }
1324                 }
1325                 /* Consume printed data from the buffer. */
1326                 buffer_consume(&stdout_buffer, len);
1327                 stdout_bytes += len;
1328         }
1329         /* Write buffered output to stderr. */
1330         if (FD_ISSET(fileno(stderr), writeset)) {
1331                 /* Write as much data as possible. */
1332                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1333                     buffer_len(&stderr_buffer));
1334                 if (len <= 0) {
1335                         if (errno == EINTR || errno == EAGAIN)
1336                                 len = 0;
1337                         else {
1338                                 /* EOF or error, but can't even print error message. */
1339                                 quit_pending = 1;
1340                                 return;
1341                         }
1342                 }
1343                 /* Consume printed characters from the buffer. */
1344                 buffer_consume(&stderr_buffer, len);
1345                 stderr_bytes += len;
1346         }
1347 }
1348
1349 /*
1350  * Get packets from the connection input buffer, and process them as long as
1351  * there are packets available.
1352  *
1353  * Any unknown packets received during the actual
1354  * session cause the session to terminate.  This is
1355  * intended to make debugging easier since no
1356  * confirmations are sent.  Any compatible protocol
1357  * extensions must be negotiated during the
1358  * preparatory phase.
1359  */
1360
1361 static void
1362 client_process_buffered_input_packets(void)
1363 {
1364         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1365 }
1366
1367 /* scan buf[] for '~' before sending data to the peer */
1368
1369 static int
1370 simple_escape_filter(Channel *c, char *buf, int len)
1371 {
1372         /* XXX we assume c->extended is writeable */
1373         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1374 }
1375
1376 static void
1377 client_channel_closed(int id, void *arg)
1378 {
1379         channel_cancel_cleanup(id);
1380         session_closed = 1;
1381         leave_raw_mode();
1382 }
1383
1384 /*
1385  * Implements the interactive session with the server.  This is called after
1386  * the user has been authenticated, and a command has been started on the
1387  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1388  * used as an escape character for terminating or suspending the session.
1389  */
1390
1391 int
1392 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1393 {
1394         fd_set *readset = NULL, *writeset = NULL;
1395         double start_time, total_time;
1396         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1397         u_int nalloc = 0;
1398         char buf[100];
1399
1400         debug("Entering interactive session.");
1401
1402         start_time = get_current_time();
1403
1404         /* Initialize variables. */
1405         escape_pending = 0;
1406         last_was_cr = 1;
1407         exit_status = -1;
1408         stdin_eof = 0;
1409         buffer_high = 64 * 1024;
1410         connection_in = packet_get_connection_in();
1411         connection_out = packet_get_connection_out();
1412         max_fd = MAX(connection_in, connection_out);
1413         if (control_fd != -1)
1414                 max_fd = MAX(max_fd, control_fd);
1415
1416         if (!compat20) {
1417                 /* enable nonblocking unless tty */
1418                 if (!isatty(fileno(stdin)))
1419                         set_nonblock(fileno(stdin));
1420                 if (!isatty(fileno(stdout)))
1421                         set_nonblock(fileno(stdout));
1422                 if (!isatty(fileno(stderr)))
1423                         set_nonblock(fileno(stderr));
1424                 max_fd = MAX(max_fd, fileno(stdin));
1425                 max_fd = MAX(max_fd, fileno(stdout));
1426                 max_fd = MAX(max_fd, fileno(stderr));
1427         }
1428         stdin_bytes = 0;
1429         stdout_bytes = 0;
1430         stderr_bytes = 0;
1431         quit_pending = 0;
1432         escape_char = escape_char_arg;
1433
1434         /* Initialize buffers. */
1435         buffer_init(&stdin_buffer);
1436         buffer_init(&stdout_buffer);
1437         buffer_init(&stderr_buffer);
1438
1439         client_init_dispatch();
1440
1441         /*
1442          * Set signal handlers, (e.g. to restore non-blocking mode)
1443          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1444          */
1445         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1446                 signal(SIGHUP, signal_handler);
1447         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1448                 signal(SIGINT, signal_handler);
1449         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1450                 signal(SIGQUIT, signal_handler);
1451         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1452                 signal(SIGTERM, signal_handler);
1453         signal(SIGWINCH, window_change_handler);
1454
1455         if (have_pty)
1456                 enter_raw_mode();
1457
1458         if (compat20) {
1459                 session_ident = ssh2_chan_id;
1460                 if (escape_char != SSH_ESCAPECHAR_NONE)
1461                         channel_register_filter(session_ident,
1462                             simple_escape_filter, NULL);
1463                 if (session_ident != -1)
1464                         channel_register_cleanup(session_ident,
1465                             client_channel_closed, 0);
1466         } else {
1467                 /* Check if we should immediately send eof on stdin. */
1468                 client_check_initial_eof_on_stdin();
1469         }
1470
1471         /* Main loop of the client for the interactive session mode. */
1472         while (!quit_pending) {
1473
1474                 /* Process buffered packets sent by the server. */
1475                 client_process_buffered_input_packets();
1476
1477                 if (compat20 && session_closed && !channel_still_open())
1478                         break;
1479
1480                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1481
1482                 if (rekeying) {
1483                         debug("rekeying in progress");
1484                 } else {
1485                         /*
1486                          * Make packets of buffered stdin data, and buffer
1487                          * them for sending to the server.
1488                          */
1489                         if (!compat20)
1490                                 client_make_packets_from_stdin_data();
1491
1492                         /*
1493                          * Make packets from buffered channel data, and
1494                          * enqueue them for sending to the server.
1495                          */
1496                         if (packet_not_very_much_data_to_write())
1497                                 channel_output_poll();
1498
1499                         /*
1500                          * Check if the window size has changed, and buffer a
1501                          * message about it to the server if so.
1502                          */
1503                         client_check_window_change();
1504
1505                         if (quit_pending)
1506                                 break;
1507                 }
1508                 /*
1509                  * Wait until we have something to do (something becomes
1510                  * available on one of the descriptors).
1511                  */
1512                 max_fd2 = max_fd;
1513                 client_wait_until_can_do_something(&readset, &writeset,
1514                     &max_fd2, &nalloc, rekeying);
1515
1516                 if (quit_pending)
1517                         break;
1518
1519                 /* Do channel operations unless rekeying in progress. */
1520                 if (!rekeying) {
1521                         channel_after_select(readset, writeset);
1522                         if (need_rekeying || packet_need_rekeying()) {
1523                                 debug("need rekeying");
1524                                 xxx_kex->done = 0;
1525                                 kex_send_kexinit(xxx_kex);
1526                                 need_rekeying = 0;
1527                         }
1528                 }
1529
1530                 /* Buffer input from the connection.  */
1531                 client_process_net_input(readset);
1532
1533                 /* Accept control connections.  */
1534                 client_process_control(readset);
1535
1536                 if (quit_pending)
1537                         break;
1538
1539                 if (!compat20) {
1540                         /* Buffer data from stdin */
1541                         client_process_input(readset);
1542                         /*
1543                          * Process output to stdout and stderr.  Output to
1544                          * the connection is processed elsewhere (above).
1545                          */
1546                         client_process_output(writeset);
1547                 }
1548
1549                 /* Send as much buffered packet data as possible to the sender. */
1550                 if (FD_ISSET(connection_out, writeset))
1551                         packet_write_poll();
1552         }
1553         if (readset)
1554                 xfree(readset);
1555         if (writeset)
1556                 xfree(writeset);
1557
1558         /* Terminate the session. */
1559
1560         /* Stop watching for window change. */
1561         signal(SIGWINCH, SIG_DFL);
1562
1563         channel_free_all();
1564
1565         if (have_pty)
1566                 leave_raw_mode();
1567
1568         /* restore blocking io */
1569         if (!isatty(fileno(stdin)))
1570                 unset_nonblock(fileno(stdin));
1571         if (!isatty(fileno(stdout)))
1572                 unset_nonblock(fileno(stdout));
1573         if (!isatty(fileno(stderr)))
1574                 unset_nonblock(fileno(stderr));
1575
1576         /*
1577          * If there was no shell or command requested, there will be no remote
1578          * exit status to be returned.  In that case, clear error code if the
1579          * connection was deliberately terminated at this end.
1580          */
1581         if (no_shell_flag && received_signal == SIGTERM) {
1582                 received_signal = 0;
1583                 exit_status = 0;
1584         }
1585
1586         if (received_signal)
1587                 fatal("Killed by signal %d.", (int) received_signal);
1588
1589         /*
1590          * In interactive mode (with pseudo tty) display a message indicating
1591          * that the connection has been closed.
1592          */
1593         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1594                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1595                 buffer_append(&stderr_buffer, buf, strlen(buf));
1596         }
1597
1598         /* Output any buffered data for stdout. */
1599         while (buffer_len(&stdout_buffer) > 0) {
1600                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1601                     buffer_len(&stdout_buffer));
1602                 if (len <= 0) {
1603                         error("Write failed flushing stdout buffer.");
1604                         break;
1605                 }
1606                 buffer_consume(&stdout_buffer, len);
1607                 stdout_bytes += len;
1608         }
1609
1610         /* Output any buffered data for stderr. */
1611         while (buffer_len(&stderr_buffer) > 0) {
1612                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1613                     buffer_len(&stderr_buffer));
1614                 if (len <= 0) {
1615                         error("Write failed flushing stderr buffer.");
1616                         break;
1617                 }
1618                 buffer_consume(&stderr_buffer, len);
1619                 stderr_bytes += len;
1620         }
1621
1622         /* Clear and free any buffers. */
1623         memset(buf, 0, sizeof(buf));
1624         buffer_free(&stdin_buffer);
1625         buffer_free(&stdout_buffer);
1626         buffer_free(&stderr_buffer);
1627
1628         /* Report bytes transferred, and transfer rates. */
1629         total_time = get_current_time() - start_time;
1630         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1631             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1632         if (total_time > 0)
1633                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1634                     stdin_bytes / total_time, stdout_bytes / total_time,
1635                     stderr_bytes / total_time);
1636
1637         /* Return the exit status of the program. */
1638         debug("Exit status %d", exit_status);
1639         return exit_status;
1640 }
1641
1642 /*********/
1643
1644 static void
1645 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1646 {
1647         u_int data_len;
1648         char *data = packet_get_string(&data_len);
1649         packet_check_eom();
1650         buffer_append(&stdout_buffer, data, data_len);
1651         memset(data, 0, data_len);
1652         xfree(data);
1653 }
1654 static void
1655 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1656 {
1657         u_int data_len;
1658         char *data = packet_get_string(&data_len);
1659         packet_check_eom();
1660         buffer_append(&stderr_buffer, data, data_len);
1661         memset(data, 0, data_len);
1662         xfree(data);
1663 }
1664 static void
1665 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1666 {
1667         exit_status = packet_get_int();
1668         packet_check_eom();
1669         /* Acknowledge the exit. */
1670         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1671         packet_send();
1672         /*
1673          * Must wait for packet to be sent since we are
1674          * exiting the loop.
1675          */
1676         packet_write_wait();
1677         /* Flag that we want to exit. */
1678         quit_pending = 1;
1679 }
1680 static void
1681 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1682 {
1683         Channel *c = NULL;
1684         int remote_id, sock;
1685
1686         /* Read the remote channel number from the message. */
1687         remote_id = packet_get_int();
1688         packet_check_eom();
1689
1690         /*
1691          * Get a connection to the local authentication agent (this may again
1692          * get forwarded).
1693          */
1694         sock = ssh_get_authentication_socket();
1695
1696         /*
1697          * If we could not connect the agent, send an error message back to
1698          * the server. This should never happen unless the agent dies,
1699          * because authentication forwarding is only enabled if we have an
1700          * agent.
1701          */
1702         if (sock >= 0) {
1703                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1704                     -1, 0, 0, 0, "authentication agent connection", 1);
1705                 c->remote_id = remote_id;
1706                 c->force_drain = 1;
1707         }
1708         if (c == NULL) {
1709                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1710                 packet_put_int(remote_id);
1711         } else {
1712                 /* Send a confirmation to the remote host. */
1713                 debug("Forwarding authentication connection.");
1714                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1715                 packet_put_int(remote_id);
1716                 packet_put_int(c->self);
1717         }
1718         packet_send();
1719 }
1720
1721 static Channel *
1722 client_request_forwarded_tcpip(const char *request_type, int rchan)
1723 {
1724         Channel *c = NULL;
1725         char *listen_address, *originator_address;
1726         int listen_port, originator_port;
1727         int sock;
1728
1729         /* Get rest of the packet */
1730         listen_address = packet_get_string(NULL);
1731         listen_port = packet_get_int();
1732         originator_address = packet_get_string(NULL);
1733         originator_port = packet_get_int();
1734         packet_check_eom();
1735
1736         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1737             listen_address, listen_port, originator_address, originator_port);
1738
1739         sock = channel_connect_by_listen_address(listen_port);
1740         if (sock < 0) {
1741                 xfree(originator_address);
1742                 xfree(listen_address);
1743                 return NULL;
1744         }
1745         if (options.hpn_disabled)
1746                 c = channel_new("forwarded-tcpip",
1747                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1748                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1749                     originator_address, 1);
1750         else
1751                 c = channel_new("forwarded-tcpip",
1752                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1753                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1754                     originator_address, 1);
1755         xfree(originator_address);
1756         xfree(listen_address);
1757         return c;
1758 }
1759
1760 static Channel *
1761 client_request_x11(const char *request_type, int rchan)
1762 {
1763         Channel *c = NULL;
1764         char *originator;
1765         int originator_port;
1766         int sock;
1767
1768         if (!options.forward_x11) {
1769                 error("Warning: ssh server tried X11 forwarding.");
1770                 error("Warning: this is probably a break-in attempt by a malicious server.");
1771                 return NULL;
1772         }
1773         originator = packet_get_string(NULL);
1774         if (datafellows & SSH_BUG_X11FWD) {
1775                 debug2("buggy server: x11 request w/o originator_port");
1776                 originator_port = 0;
1777         } else {
1778                 originator_port = packet_get_int();
1779         }
1780         packet_check_eom();
1781         /* XXX check permission */
1782         debug("client_request_x11: request from %s %d", originator,
1783             originator_port);
1784         xfree(originator);
1785         sock = x11_connect_display();
1786         if (sock < 0)
1787                 return NULL;
1788         if (options.hpn_disabled)
1789                 c = channel_new("x11",
1790                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1791                     CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1792         else
1793                 c = channel_new("x11",
1794                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1795                     options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1796         c->force_drain = 1;
1797         return c;
1798 }
1799
1800 static Channel *
1801 client_request_agent(const char *request_type, int rchan)
1802 {
1803         Channel *c = NULL;
1804         int sock;
1805
1806         if (!options.forward_agent) {
1807                 error("Warning: ssh server tried agent forwarding.");
1808                 error("Warning: this is probably a break-in attempt by a malicious server.");
1809                 return NULL;
1810         }
1811         sock =  ssh_get_authentication_socket();
1812         if (sock < 0)
1813                 return NULL;
1814         if (options.hpn_disabled)
1815                 c = channel_new("authentication agent connection",
1816                     SSH_CHANNEL_OPEN, sock, sock, -1,
1817                     CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1818                     "authentication agent connection", 1);
1819         else
1820                 c = channel_new("authentication agent connection",
1821                     SSH_CHANNEL_OPEN, sock, sock, -1,
1822                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1823                     "authentication agent connection", 1);
1824         c->force_drain = 1;
1825         return c;
1826 }
1827
1828 /* XXXX move to generic input handler */
1829 static void
1830 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1831 {
1832         Channel *c = NULL;
1833         char *ctype;
1834         int rchan;
1835         u_int rmaxpack, rwindow, len;
1836
1837         ctype = packet_get_string(&len);
1838         rchan = packet_get_int();
1839         rwindow = packet_get_int();
1840         rmaxpack = packet_get_int();
1841
1842         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1843             ctype, rchan, rwindow, rmaxpack);
1844
1845         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1846                 c = client_request_forwarded_tcpip(ctype, rchan);
1847         } else if (strcmp(ctype, "x11") == 0) {
1848                 c = client_request_x11(ctype, rchan);
1849         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1850                 c = client_request_agent(ctype, rchan);
1851         }
1852 /* XXX duplicate : */
1853         if (c != NULL) {
1854                 debug("confirm %s", ctype);
1855                 c->remote_id = rchan;
1856                 c->remote_window = rwindow;
1857                 c->remote_maxpacket = rmaxpack;
1858                 if (c->type != SSH_CHANNEL_CONNECTING) {
1859                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1860                         packet_put_int(c->remote_id);
1861                         packet_put_int(c->self);
1862                         packet_put_int(c->local_window);
1863                         packet_put_int(c->local_maxpacket);
1864                         packet_send();
1865                 }
1866         } else {
1867                 debug("failure %s", ctype);
1868                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1869                 packet_put_int(rchan);
1870                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1871                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1872                         packet_put_cstring("open failed");
1873                         packet_put_cstring("");
1874                 }
1875                 packet_send();
1876         }
1877         xfree(ctype);
1878 }
1879 static void
1880 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1881 {
1882         Channel *c = NULL;
1883         int exitval, id, reply, success = 0;
1884         char *rtype;
1885
1886         id = packet_get_int();
1887         rtype = packet_get_string(NULL);
1888         reply = packet_get_char();
1889
1890         debug("client_input_channel_req: channel %d rtype %s reply %d",
1891             id, rtype, reply);
1892
1893         if (id == -1) {
1894                 error("client_input_channel_req: request for channel -1");
1895         } else if ((c = channel_lookup(id)) == NULL) {
1896                 error("client_input_channel_req: channel %d: unknown channel", id);
1897         } else if (strcmp(rtype, "exit-status") == 0) {
1898                 exitval = packet_get_int();
1899                 if (id == session_ident) {
1900                         success = 1;
1901                         exit_status = exitval;
1902                 } else if (c->ctl_fd == -1) {
1903                         error("client_input_channel_req: unexpected channel %d",
1904                             session_ident);
1905                 } else {
1906                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1907                         success = 1;
1908                 }
1909                 packet_check_eom();
1910         }
1911         if (reply) {
1912                 packet_start(success ?
1913                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1914                 packet_put_int(id);
1915                 packet_send();
1916         }
1917         xfree(rtype);
1918 }
1919 static void
1920 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1921 {
1922         char *rtype;
1923         int want_reply;
1924         int success = 0;
1925
1926         rtype = packet_get_string(NULL);
1927         want_reply = packet_get_char();
1928         debug("client_input_global_request: rtype %s want_reply %d",
1929             rtype, want_reply);
1930         if (want_reply) {
1931                 packet_start(success ?
1932                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1933                 packet_send();
1934                 packet_write_wait();
1935         }
1936         xfree(rtype);
1937 }
1938
1939 void
1940 client_session2_setup(int id, int want_tty, int want_subsystem,
1941     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1942     dispatch_fn *subsys_repl)
1943 {
1944         int len;
1945         Channel *c = NULL;
1946
1947         debug2("%s: id %d", __func__, id);
1948
1949         if ((c = channel_lookup(id)) == NULL)
1950                 fatal("client_session2_setup: channel %d: unknown channel", id);
1951
1952         if (want_tty) {
1953                 struct winsize ws;
1954                 struct termios tio;
1955
1956                 /* Store window size in the packet. */
1957                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1958                         memset(&ws, 0, sizeof(ws));
1959
1960                 channel_request_start(id, "pty-req", 0);
1961                 packet_put_cstring(term != NULL ? term : "");
1962                 packet_put_int((u_int)ws.ws_col);
1963                 packet_put_int((u_int)ws.ws_row);
1964                 packet_put_int((u_int)ws.ws_xpixel);
1965                 packet_put_int((u_int)ws.ws_ypixel);
1966                 tio = get_saved_tio();
1967                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1968                 packet_send();
1969                 /* XXX wait for reply */
1970                 c->client_tty = 1;
1971         }
1972
1973         /* Transfer any environment variables from client to server */
1974         if (options.num_send_env != 0 && env != NULL) {
1975                 int i, j, matched;
1976                 char *name, *val;
1977
1978                 debug("Sending environment.");
1979                 for (i = 0; env[i] != NULL; i++) {
1980                         /* Split */
1981                         name = xstrdup(env[i]);
1982                         if ((val = strchr(name, '=')) == NULL) {
1983                                 xfree(name);
1984                                 continue;
1985                         }
1986                         *val++ = '\0';
1987
1988                         matched = 0;
1989                         for (j = 0; j < options.num_send_env; j++) {
1990                                 if (match_pattern(name, options.send_env[j])) {
1991                                         matched = 1;
1992                                         break;
1993                                 }
1994                         }
1995                         if (!matched) {
1996                                 debug3("Ignored env %s", name);
1997                                 xfree(name);
1998                                 continue;
1999                         }
2000
2001                         debug("Sending env %s = %s", name, val);
2002                         channel_request_start(id, "env", 0);
2003                         packet_put_cstring(name);
2004                         packet_put_cstring(val);
2005                         packet_send();
2006                         xfree(name);
2007                 }
2008         }
2009
2010         len = buffer_len(cmd);
2011         if (len > 0) {
2012                 if (len > 900)
2013                         len = 900;
2014                 if (want_subsystem) {
2015                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
2016                         channel_request_start(id, "subsystem", subsys_repl != NULL);
2017                         if (subsys_repl != NULL) {
2018                                 /* register callback for reply */
2019                                 /* XXX we assume that client_loop has already been called */
2020                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
2021                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
2022                         }
2023                 } else {
2024                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
2025                         channel_request_start(id, "exec", 0);
2026                 }
2027                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2028                 packet_send();
2029         } else {
2030                 channel_request_start(id, "shell", 0);
2031                 packet_send();
2032         }
2033 }
2034
2035 static void
2036 client_init_dispatch_20(void)
2037 {
2038         dispatch_init(&dispatch_protocol_error);
2039
2040         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2041         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2042         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2043         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2044         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2045         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2046         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2047         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2048         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2049         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2050
2051         /* rekeying */
2052         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2053
2054         /* global request reply messages */
2055         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2056         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2057 }
2058 static void
2059 client_init_dispatch_13(void)
2060 {
2061         dispatch_init(NULL);
2062         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2063         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2064         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2065         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2066         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2067         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2068         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2069         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2070         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2071
2072         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2073             &client_input_agent_open : &deny_input_open);
2074         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2075             &x11_input_open : &deny_input_open);
2076 }
2077 static void
2078 client_init_dispatch_15(void)
2079 {
2080         client_init_dispatch_13();
2081         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2082         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2083 }
2084 static void
2085 client_init_dispatch(void)
2086 {
2087         if (compat20)
2088                 client_init_dispatch_20();
2089         else if (compat13)
2090                 client_init_dispatch_13();
2091         else
2092                 client_init_dispatch_15();
2093 }
2094
2095 /* client specific fatal cleanup */
2096 void
2097 cleanup_exit(int i)
2098 {
2099         leave_raw_mode();
2100         leave_non_blocking();
2101         if (options.control_path != NULL && control_fd != -1)
2102                 unlink(options.control_path);
2103         _exit(i);
2104 }