openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.178 2007/02/20 10:25:14 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * The main loop for the interactive session (client side).
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  *
  15  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  *
  38  * SSH2 support added by Markus Friedl.
  39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #include "includes.h"
  63
  64 #include <sys/types.h>
  65 #include <sys/ioctl.h>
  66 #include <sys/param.h>
  67 #ifdef HAVE_SYS_STAT_H
  68 # include <sys/stat.h>
  69 #endif
  70 #ifdef HAVE_SYS_TIME_H
  71 # include <sys/time.h>
  72 #endif
  73 #include <sys/socket.h>
  74
  75 #include <ctype.h>
  76 #include <errno.h>
  77 #ifdef HAVE_PATHS_H
  78 #include <paths.h>
  79 #endif
  80 #include <signal.h>
  81 #include <stdarg.h>
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <string.h>
  85 #include <termios.h>
  86 #include <pwd.h>
  87 #include <unistd.h>
  88
  89 #include "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                 logit("Timeout, server not responding.");
 469                 cleanup_exit(255);
 470         }
 471         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 472         packet_put_cstring("keepalive@openssh.com");
 473         packet_put_char(1);     /* boolean: want reply */
 474         packet_send();
 475 }
 476
 477 /*
 478  * Waits until the client can do something (some data becomes available on
 479  * one of the file descriptors).
 480  */
 481 static void
 482 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 483     int *maxfdp, u_int *nallocp, int rekeying)
 484 {
 485         struct timeval tv, *tvp;
 486         int ret;
 487
 488         /* Add any selections by the channel mechanism. */
 489         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 490
 491         if (!compat20) {
 492                 /* Read from the connection, unless our buffers are full. */
 493                 if (buffer_len(&stdout_buffer) < buffer_high &&
 494                     buffer_len(&stderr_buffer) < buffer_high &&
 495                     channel_not_very_much_buffered_data())
 496                         FD_SET(connection_in, *readsetp);
 497                 /*
 498                  * Read from stdin, unless we have seen EOF or have very much
 499                  * buffered data to send to the server.
 500                  */
 501                 if (!stdin_eof && packet_not_very_much_data_to_write())
 502                         FD_SET(fileno(stdin), *readsetp);
 503
 504                 /* Select stdout/stderr if have data in buffer. */
 505                 if (buffer_len(&stdout_buffer) > 0)
 506                         FD_SET(fileno(stdout), *writesetp);
 507                 if (buffer_len(&stderr_buffer) > 0)
 508                         FD_SET(fileno(stderr), *writesetp);
 509         } else {
 510                 /* channel_prepare_select could have closed the last channel */
 511                 if (session_closed && !channel_still_open() &&
 512                     !packet_have_data_to_write()) {
 513                         /* clear mask since we did not call select() */
 514                         memset(*readsetp, 0, *nallocp);
 515                         memset(*writesetp, 0, *nallocp);
 516                         return;
 517                 } else {
 518                         FD_SET(connection_in, *readsetp);
 519                 }
 520         }
 521
 522         /* Select server connection if have data to write to the server. */
 523         if (packet_have_data_to_write())
 524                 FD_SET(connection_out, *writesetp);
 525
 526         if (control_fd != -1)
 527                 FD_SET(control_fd, *readsetp);
 528
 529         /*
 530          * Wait for something to happen.  This will suspend the process until
 531          * some selected descriptor can be read, written, or has some other
 532          * event pending.
 533          */
 534
 535         if (options.server_alive_interval == 0 || !compat20)
 536                 tvp = NULL;
 537         else {
 538                 tv.tv_sec = options.server_alive_interval;
 539                 tv.tv_usec = 0;
 540                 tvp = &tv;
 541         }
 542         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 543         if (ret < 0) {
 544                 char buf[100];
 545
 546                 /*
 547                  * We have to clear the select masks, because we return.
 548                  * We have to return, because the mainloop checks for the flags
 549                  * set by the signal handlers.
 550                  */
 551                 memset(*readsetp, 0, *nallocp);
 552                 memset(*writesetp, 0, *nallocp);
 553
 554                 if (errno == EINTR)
 555                         return;
 556                 /* Note: we might still have data in the buffers. */
 557                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 558                 buffer_append(&stderr_buffer, buf, strlen(buf));
 559                 quit_pending = 1;
 560         } else if (ret == 0)
 561                 server_alive_check();
 562 }
 563
 564 static void
 565 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 566 {
 567         /* Flush stdout and stderr buffers. */
 568         if (buffer_len(bout) > 0)
 569                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 570         if (buffer_len(berr) > 0)
 571                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 572
 573         leave_raw_mode();
 574
 575         /*
 576          * Free (and clear) the buffer to reduce the amount of data that gets
 577          * written to swap.
 578          */
 579         buffer_free(bin);
 580         buffer_free(bout);
 581         buffer_free(berr);
 582
 583         /* Send the suspend signal to the program itself. */
 584         kill(getpid(), SIGTSTP);
 585
 586         /* Reset window sizes in case they have changed */
 587         received_window_change_signal = 1;
 588
 589         /* OK, we have been continued by the user. Reinitialize buffers. */
 590         buffer_init(bin);
 591         buffer_init(bout);
 592         buffer_init(berr);
 593
 594         enter_raw_mode();
 595 }
 596
 597 static void
 598 client_process_net_input(fd_set *readset)
 599 {
 600         int len;
 601         char buf[8192];
 602
 603         /*
 604          * Read input from the server, and add any such data to the buffer of
 605          * the packet subsystem.
 606          */
 607         if (FD_ISSET(connection_in, readset)) {
 608                 /* Read as much as possible. */
 609                 len = read(connection_in, buf, sizeof(buf));
 610                 if (len == 0) {
 611                         /* Received EOF.  The remote host has closed the connection. */
 612                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 613                                  host);
 614                         buffer_append(&stderr_buffer, buf, strlen(buf));
 615                         quit_pending = 1;
 616                         return;
 617                 }
 618                 /*
 619                  * There is a kernel bug on Solaris that causes select to
 620                  * sometimes wake up even though there is no data available.
 621                  */
 622                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 623                         len = 0;
 624
 625                 if (len < 0) {
 626                         /* An error has encountered.  Perhaps there is a network problem. */
 627                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 628                                  host, strerror(errno));
 629                         buffer_append(&stderr_buffer, buf, strlen(buf));
 630                         quit_pending = 1;
 631                         return;
 632                 }
 633                 packet_process_incoming(buf, len);
 634         }
 635 }
 636
 637 static void
 638 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 639 {
 640         int id;
 641         Channel *c;
 642
 643         id = packet_get_int();
 644         packet_check_eom();
 645
 646         if ((c = channel_lookup(id)) == NULL) {
 647                 error("%s: no channel for id %d", __func__, id);
 648                 return;
 649         }
 650
 651         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 652                 debug2("Request suceeded on channel %d", id);
 653         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 654                 error("Request failed on channel %d", id);
 655                 channel_free(c);
 656         }
 657 }
 658
 659 static void
 660 client_extra_session2_setup(int id, void *arg)
 661 {
 662         struct confirm_ctx *cctx = arg;
 663         const char *display;
 664         Channel *c;
 665         int i;
 666
 667         if (cctx == NULL)
 668                 fatal("%s: cctx == NULL", __func__);
 669         if ((c = channel_lookup(id)) == NULL)
 670                 fatal("%s: no channel for id %d", __func__, id);
 671
 672         display = getenv("DISPLAY");
 673         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 674                 char *proto, *data;
 675                 /* Get reasonable local authentication information. */
 676                 client_x11_get_proto(display, options.xauth_location,
 677                     options.forward_x11_trusted, &proto, &data);
 678                 /* Request forwarding with authentication spoofing. */
 679                 debug("Requesting X11 forwarding with authentication spoofing.");
 680                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 681                 /* XXX wait for reply */
 682         }
 683
 684         if (cctx->want_agent_fwd && options.forward_agent) {
 685                 debug("Requesting authentication agent forwarding.");
 686                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 687                 packet_send();
 688         }
 689
 690         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 691             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 692             client_subsystem_reply);
 693
 694         c->confirm_ctx = NULL;
 695         buffer_free(&cctx->cmd);
 696         xfree(cctx->term);
 697         if (cctx->env != NULL) {
 698                 for (i = 0; cctx->env[i] != NULL; i++)
 699                         xfree(cctx->env[i]);
 700                 xfree(cctx->env);
 701         }
 702         xfree(cctx);
 703 }
 704
 705 static void
 706 client_process_control(fd_set *readset)
 707 {
 708         Buffer m;
 709         Channel *c;
 710         int client_fd, new_fd[3], ver, allowed, window, packetmax;
 711         socklen_t addrlen;
 712         struct sockaddr_storage addr;
 713         struct confirm_ctx *cctx;
 714         char *cmd;
 715         u_int i, len, env_len, command, flags;
 716         uid_t euid;
 717         gid_t egid;
 718         int listen_port = 0;
 719         int connect_port = 0;
 720         char * listen_host = NULL;
 721         char * connect_host = NULL;
 722
 723         /*
 724          * Accept connection on control socket
 725          */
 726         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 727                 return;
 728
 729         memset(&addr, 0, sizeof(addr));
 730         addrlen = sizeof(addr);
 731         if ((client_fd = accept(control_fd,
 732             (struct sockaddr*)&addr, &addrlen)) == -1) {
 733                 error("%s accept: %s", __func__, strerror(errno));
 734                 return;
 735         }
 736
 737         if (getpeereid(client_fd, &euid, &egid) < 0) {
 738                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 739                 close(client_fd);
 740                 return;
 741         }
 742         if ((euid != 0) && (getuid() != euid)) {
 743                 error("control mode uid mismatch: peer euid %u != uid %u",
 744                     (u_int) euid, (u_int) getuid());
 745                 close(client_fd);
 746                 return;
 747         }
 748
 749         unset_nonblock(client_fd);
 750
 751         /* Read command */
 752         buffer_init(&m);
 753         if (ssh_msg_recv(client_fd, &m) == -1) {
 754                 error("%s: client msg_recv failed", __func__);
 755                 close(client_fd);
 756                 buffer_free(&m);
 757                 return;
 758         }
 759         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 760                 error("%s: wrong client version %d", __func__, ver);
 761                 buffer_free(&m);
 762                 close(client_fd);
 763                 return;
 764         }
 765
 766         allowed = 1;
 767         command = buffer_get_int(&m);
 768         flags = buffer_get_int(&m);
 769
 770         if (SSHMUX_FLAG_PORTFORWARD & flags)
 771         {
 772                 listen_host = buffer_get_string(&m,NULL);
 773                 listen_port = buffer_get_int(&m);
 774                 connect_host = buffer_get_string(&m,NULL);
 775                 connect_port = buffer_get_int(&m);
 776         }
 777         buffer_clear(&m);
 778
 779         switch (command) {
 780         case SSHMUX_COMMAND_OPEN:
 781                 if (options.control_master == SSHCTL_MASTER_ASK ||
 782                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 783                         allowed = ask_permission("Allow shared connection "
 784                             "to %s? ", host);
 785                 /* continue below */
 786                 break;
 787         case SSHMUX_COMMAND_TERMINATE:
 788                 if (options.control_master == SSHCTL_MASTER_ASK ||
 789                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 790                         allowed = ask_permission("Terminate shared connection "
 791                             "to %s? ", host);
 792                 if (allowed)
 793                         quit_pending = 1;
 794                 /* FALLTHROUGH */
 795         case SSHMUX_COMMAND_ALIVE_CHECK:
 796                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 797                 buffer_clear(&m);
 798                 buffer_put_int(&m, allowed);
 799                 buffer_put_int(&m, getpid());
 800                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 801                         error("%s: client msg_send failed", __func__);
 802                         close(client_fd);
 803                         buffer_free(&m);
 804                         return;
 805                 }
 806                 buffer_free(&m);
 807                 close(client_fd);
 808                 return;
 809         default:
 810                 error("Unsupported command %d", command);
 811                 buffer_free(&m);
 812                 close(client_fd);
 813                 return;
 814         }
 815
 816         if (allowed && (SSHMUX_FLAG_PORTFORWARD & flags) && listen_host && connect_host)
 817         {
 818                 int ret;
 819                 Forward * fwd;
 820
 821                 fwd = &options.local_forwards[options.num_local_forwards++];
 822                 fwd->listen_host = xstrdup(listen_host);
 823                 fwd->listen_port = listen_port;
 824                 fwd->connect_host = xstrdup(connect_host);
 825                 fwd->connect_port = connect_port;
 826                 ret = channel_setup_local_fwd_listener(
 827                         options.local_forwards[options.num_local_forwards-1].listen_host,
 828                         options.local_forwards[options.num_local_forwards-1].listen_port,
 829                         options.local_forwards[options.num_local_forwards-1].connect_host,
 830                         options.local_forwards[options.num_local_forwards-1].connect_port,
 831                         options.gateway_ports, options.hpn_disabled, options.hpn_buffer_size);
 832
 833         }
 834
 835
 836         if (listen_host)
 837                 xfree(listen_host);
 838         if (connect_host)
 839                 xfree(connect_host);
 840
 841         /* Reply for SSHMUX_COMMAND_OPEN */
 842         buffer_clear(&m);
 843         buffer_put_int(&m, allowed);
 844         buffer_put_int(&m, getpid());
 845         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 846                 error("%s: client msg_send failed", __func__);
 847                 close(client_fd);
 848                 buffer_free(&m);
 849                 return;
 850         }
 851
 852         if (!allowed) {
 853                 error("Refused control connection");
 854                 close(client_fd);
 855                 buffer_free(&m);
 856                 return;
 857         }
 858
 859         buffer_clear(&m);
 860         if (ssh_msg_recv(client_fd, &m) == -1) {
 861                 error("%s: client msg_recv failed", __func__);
 862                 close(client_fd);
 863                 buffer_free(&m);
 864                 return;
 865         }
 866         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 867                 error("%s: wrong client version %d", __func__, ver);
 868                 buffer_free(&m);
 869                 close(client_fd);
 870                 return;
 871         }
 872
 873         cctx = xcalloc(1, sizeof(*cctx));
 874         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 875         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 876         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 877         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 878         cctx->term = buffer_get_string(&m, &len);
 879
 880         cmd = buffer_get_string(&m, &len);
 881         buffer_init(&cctx->cmd);
 882         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 883
 884         env_len = buffer_get_int(&m);
 885         env_len = MIN(env_len, 4096);
 886         debug3("%s: receiving %d env vars", __func__, env_len);
 887         if (env_len != 0) {
 888                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 889                 for (i = 0; i < env_len; i++)
 890                         cctx->env[i] = buffer_get_string(&m, &len);
 891                 cctx->env[i] = NULL;
 892         }
 893
 894         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 895             cctx->want_tty, cctx->want_subsys, cmd);
 896         xfree(cmd);
 897
 898         /* Gather fds from client */
 899         new_fd[0] = mm_receive_fd(client_fd);
 900         new_fd[1] = mm_receive_fd(client_fd);
 901         new_fd[2] = mm_receive_fd(client_fd);
 902
 903         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 904             new_fd[0], new_fd[1], new_fd[2]);
 905
 906         /* Try to pick up ttymodes from client before it goes raw */
 907         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 908                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 909
 910         /* This roundtrip is just for synchronisation of ttymodes */
 911         buffer_clear(&m);
 912         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 913                 error("%s: client msg_send failed", __func__);
 914                 close(client_fd);
 915                 close(new_fd[0]);
 916                 close(new_fd[1]);
 917                 close(new_fd[2]);
 918                 buffer_free(&m);
 919                 xfree(cctx->term);
 920                 if (env_len != 0) {
 921                         for (i = 0; i < env_len; i++)
 922                                 xfree(cctx->env[i]);
 923                         xfree(cctx->env);
 924                 }
 925                 return;
 926         }
 927         buffer_free(&m);
 928
 929         /* enable nonblocking unless tty */
 930         if (!isatty(new_fd[0]))
 931                 set_nonblock(new_fd[0]);
 932         if (!isatty(new_fd[1]))
 933                 set_nonblock(new_fd[1]);
 934         if (!isatty(new_fd[2]))
 935                 set_nonblock(new_fd[2]);
 936
 937         set_nonblock(client_fd);
 938
 939         if (options.hpn_disabled)
 940           window = options.hpn_buffer_size;
 941         else
 942           window = CHAN_SES_WINDOW_DEFAULT;
 943         packetmax = CHAN_SES_PACKET_DEFAULT;
 944         if (cctx->want_tty) {
 945                 window >>= 1;
 946                 packetmax >>= 1;
 947         }
 948
 949         c = channel_new("session", SSH_CHANNEL_OPENING,
 950             new_fd[0], new_fd[1], new_fd[2], window, packetmax,
 951             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 952
 953         /* XXX */
 954         c->ctl_fd = client_fd;
 955
 956         debug3("%s: channel_new: %d", __func__, c->self);
 957
 958         channel_send_open(c->self);
 959         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 960 }
 961
 962 static void
 963 process_cmdline(void)
 964 {
 965         void (*handler)(int);
 966         char *s, *cmd, *cancel_host;
 967         int delete = 0;
 968         int local = 0;
 969         u_short cancel_port;
 970         Forward fwd;
 971
 972         leave_raw_mode();
 973         handler = signal(SIGINT, SIG_IGN);
 974         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 975         if (s == NULL)
 976                 goto out;
 977         while (*s && isspace(*s))
 978                 s++;
 979         if (*s == '-')
 980                 s++;    /* Skip cmdline '-', if any */
 981         if (*s == '\0')
 982                 goto out;
 983
 984         if (*s == 'h' || *s == 'H' || *s == '?') {
 985                 logit("Commands:");
 986                 logit("      -L[bind_address:]port:host:hostport    "
 987                     "Request local forward");
 988                 logit("      -R[bind_address:]port:host:hostport    "
 989                     "Request remote forward");
 990                 logit("      -KR[bind_address:]port                 "
 991                     "Cancel remote forward");
 992                 if (!options.permit_local_command)
 993                         goto out;
 994                 logit("      !args                                  "
 995                     "Execute local command");
 996                 goto out;
 997         }
 998
 999         if (*s == '!' && options.permit_local_command) {
1000                 s++;
1001                 ssh_local_cmd(s);
1002                 goto out;
1003         }
1004
1005         if (*s == 'K') {
1006                 delete = 1;
1007                 s++;
1008         }
1009         if (*s != 'L' && *s != 'R') {
1010                 logit("Invalid command.");
1011                 goto out;
1012         }
1013         if (*s == 'L')
1014                 local = 1;
1015         if (local && delete) {
1016                 logit("Not supported.");
1017                 goto out;
1018         }
1019         if ((!local || delete) && !compat20) {
1020                 logit("Not supported for SSH protocol version 1.");
1021                 goto out;
1022         }
1023
1024         s++;
1025         while (*s && isspace(*s))
1026                 s++;
1027
1028         if (delete) {
1029                 cancel_port = 0;
1030                 cancel_host = hpdelim(&s);      /* may be NULL */
1031                 if (s != NULL) {
1032                         cancel_port = a2port(s);
1033                         cancel_host = cleanhostname(cancel_host);
1034                 } else {
1035                         cancel_port = a2port(cancel_host);
1036                         cancel_host = NULL;
1037                 }
1038                 if (cancel_port == 0) {
1039                         logit("Bad forwarding close port");
1040                         goto out;
1041                 }
1042                 channel_request_rforward_cancel(cancel_host, cancel_port);
1043         } else {
1044                 if (!parse_forward(&fwd, s)) {
1045                         logit("Bad forwarding specification.");
1046                         goto out;
1047                 }
1048                 if (local) {
1049                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1050                             fwd.listen_port, fwd.connect_host,
1051                             fwd.connect_port, options.gateway_ports,
1052                             options.hpn_disabled, options.hpn_buffer_size) < 0) {
1053                                 logit("Port forwarding failed.");
1054                                 goto out;
1055                         }
1056                 } else {
1057                         if (channel_request_remote_forwarding(fwd.listen_host,
1058                             fwd.listen_port, fwd.connect_host,
1059                             fwd.connect_port) < 0) {
1060                                 logit("Port forwarding failed.");
1061                                 goto out;
1062                         }
1063                 }
1064
1065                 logit("Forwarding port.");
1066         }
1067
1068 out:
1069         signal(SIGINT, handler);
1070         enter_raw_mode();
1071         if (cmd)
1072                 xfree(cmd);
1073 }
1074
1075 /* process the characters one by one */
1076 static int
1077 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1078 {
1079         char string[1024];
1080         pid_t pid;
1081         int bytes = 0;
1082         u_int i;
1083         u_char ch;
1084         char *s;
1085
1086         if (len <= 0)
1087                 return (0);
1088
1089         for (i = 0; i < (u_int)len; i++) {
1090                 /* Get one character at a time. */
1091                 ch = buf[i];
1092
1093                 if (escape_pending) {
1094                         /* We have previously seen an escape character. */
1095                         /* Clear the flag now. */
1096                         escape_pending = 0;
1097
1098                         /* Process the escaped character. */
1099                         switch (ch) {
1100                         case '.':
1101                                 /* Terminate the connection. */
1102                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1103                                 buffer_append(berr, string, strlen(string));
1104
1105                                 quit_pending = 1;
1106                                 return -1;
1107
1108                         case 'Z' - 64:
1109                                 /* Suspend the program. */
1110                                 /* Print a message to that effect to the user. */
1111                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1112                                 buffer_append(berr, string, strlen(string));
1113
1114                                 /* Restore terminal modes and suspend. */
1115                                 client_suspend_self(bin, bout, berr);
1116
1117                                 /* We have been continued. */
1118                                 continue;
1119
1120                         case 'B':
1121                                 if (compat20) {
1122                                         snprintf(string, sizeof string,
1123                                             "%cB\r\n", escape_char);
1124                                         buffer_append(berr, string,
1125                                             strlen(string));
1126                                         channel_request_start(session_ident,
1127                                             "break", 0);
1128                                         packet_put_int(1000);
1129                                         packet_send();
1130                                 }
1131                                 continue;
1132
1133                         case 'R':
1134                                 if (compat20) {
1135                                         if (datafellows & SSH_BUG_NOREKEY)
1136                                                 logit("Server does not support re-keying");
1137                                         else
1138                                                 need_rekeying = 1;
1139                                 }
1140                                 continue;
1141
1142                         case '&':
1143                                 /*
1144                                  * Detach the program (continue to serve connections,
1145                                  * but put in background and no more new connections).
1146                                  */
1147                                 /* Restore tty modes. */
1148                                 leave_raw_mode();
1149
1150                                 /* Stop listening for new connections. */
1151                                 channel_stop_listening();
1152
1153                                 snprintf(string, sizeof string,
1154                                     "%c& [backgrounded]\n", escape_char);
1155                                 buffer_append(berr, string, strlen(string));
1156
1157                                 /* Fork into background. */
1158                                 pid = fork();
1159                                 if (pid < 0) {
1160                                         error("fork: %.100s", strerror(errno));
1161                                         continue;
1162                                 }
1163                                 if (pid != 0) { /* This is the parent. */
1164                                         /* The parent just exits. */
1165                                         exit(0);
1166                                 }
1167                                 /* The child continues serving connections. */
1168                                 if (compat20) {
1169                                         buffer_append(bin, "\004", 1);
1170                                         /* fake EOF on stdin */
1171                                         return -1;
1172                                 } else if (!stdin_eof) {
1173                                         /*
1174                                          * Sending SSH_CMSG_EOF alone does not always appear
1175                                          * to be enough.  So we try to send an EOF character
1176                                          * first.
1177                                          */
1178                                         packet_start(SSH_CMSG_STDIN_DATA);
1179                                         packet_put_string("\004", 1);
1180                                         packet_send();
1181                                         /* Close stdin. */
1182                                         stdin_eof = 1;
1183                                         if (buffer_len(bin) == 0) {
1184                                                 packet_start(SSH_CMSG_EOF);
1185                                                 packet_send();
1186                                         }
1187                                 }
1188                                 continue;
1189
1190                         case '?':
1191                                 snprintf(string, sizeof string,
1192 "%c?\r\n\
1193 Supported escape sequences:\r\n\
1194 %c.  - terminate connection\r\n\
1195 %cB  - send a BREAK to the remote system\r\n\
1196 %cC  - open a command line\r\n\
1197 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1198 %c^Z - suspend ssh\r\n\
1199 %c#  - list forwarded connections\r\n\
1200 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1201 %c?  - this message\r\n\
1202 %c%c  - send the escape character by typing it twice\r\n\
1203 (Note that escapes are only recognized immediately after newline.)\r\n",
1204                                     escape_char, escape_char, escape_char, escape_char,
1205                                     escape_char, escape_char, escape_char, escape_char,
1206                                     escape_char, escape_char, escape_char);
1207                                 buffer_append(berr, string, strlen(string));
1208                                 continue;
1209
1210                         case '#':
1211                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1212                                 buffer_append(berr, string, strlen(string));
1213                                 s = channel_open_message();
1214                                 buffer_append(berr, s, strlen(s));
1215                                 xfree(s);
1216                                 continue;
1217
1218                         case 'C':
1219                                 process_cmdline();
1220                                 continue;
1221
1222                         default:
1223                                 if (ch != escape_char) {
1224                                         buffer_put_char(bin, escape_char);
1225                                         bytes++;
1226                                 }
1227                                 /* Escaped characters fall through here */
1228                                 break;
1229                         }
1230                 } else {
1231                         /*
1232                          * The previous character was not an escape char. Check if this
1233                          * is an escape.
1234                          */
1235                         if (last_was_cr && ch == escape_char) {
1236                                 /* It is. Set the flag and continue to next character. */
1237                                 escape_pending = 1;
1238                                 continue;
1239                         }
1240                 }
1241
1242                 /*
1243                  * Normal character.  Record whether it was a newline,
1244                  * and append it to the buffer.
1245                  */
1246                 last_was_cr = (ch == '\r' || ch == '\n');
1247                 buffer_put_char(bin, ch);
1248                 bytes++;
1249         }
1250         return bytes;
1251 }
1252
1253 static void
1254 client_process_input(fd_set *readset)
1255 {
1256         int len;
1257         char buf[8192];
1258
1259         /* Read input from stdin. */
1260         if (FD_ISSET(fileno(stdin), readset)) {
1261                 /* Read as much as possible. */
1262                 len = read(fileno(stdin), buf, sizeof(buf));
1263                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1264                         return;         /* we'll try again later */
1265                 if (len <= 0) {
1266                         /*
1267                          * Received EOF or error.  They are treated
1268                          * similarly, except that an error message is printed
1269                          * if it was an error condition.
1270                          */
1271                         if (len < 0) {
1272                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1273                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1274                         }
1275                         /* Mark that we have seen EOF. */
1276                         stdin_eof = 1;
1277                         /*
1278                          * Send an EOF message to the server unless there is
1279                          * data in the buffer.  If there is data in the
1280                          * buffer, no message will be sent now.  Code
1281                          * elsewhere will send the EOF when the buffer
1282                          * becomes empty if stdin_eof is set.
1283                          */
1284                         if (buffer_len(&stdin_buffer) == 0) {
1285                                 packet_start(SSH_CMSG_EOF);
1286                                 packet_send();
1287                         }
1288                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1289                         /*
1290                          * Normal successful read, and no escape character.
1291                          * Just append the data to buffer.
1292                          */
1293                         buffer_append(&stdin_buffer, buf, len);
1294                 } else {
1295                         /*
1296                          * Normal, successful read.  But we have an escape character
1297                          * and have to process the characters one by one.
1298                          */
1299                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1300                             &stderr_buffer, buf, len) == -1)
1301                                 return;
1302                 }
1303         }
1304 }
1305
1306 static void
1307 client_process_output(fd_set *writeset)
1308 {
1309         int len;
1310         char buf[100];
1311
1312         /* Write buffered output to stdout. */
1313         if (FD_ISSET(fileno(stdout), writeset)) {
1314                 /* Write as much data as possible. */
1315                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1316                     buffer_len(&stdout_buffer));
1317                 if (len <= 0) {
1318                         if (errno == EINTR || errno == EAGAIN)
1319                                 len = 0;
1320                         else {
1321                                 /*
1322                                  * An error or EOF was encountered.  Put an
1323                                  * error message to stderr buffer.
1324                                  */
1325                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1326                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1327                                 quit_pending = 1;
1328                                 return;
1329                         }
1330                 }
1331                 /* Consume printed data from the buffer. */
1332                 buffer_consume(&stdout_buffer, len);
1333                 stdout_bytes += len;
1334         }
1335         /* Write buffered output to stderr. */
1336         if (FD_ISSET(fileno(stderr), writeset)) {
1337                 /* Write as much data as possible. */
1338                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1339                     buffer_len(&stderr_buffer));
1340                 if (len <= 0) {
1341                         if (errno == EINTR || errno == EAGAIN)
1342                                 len = 0;
1343                         else {
1344                                 /* EOF or error, but can't even print error message. */
1345                                 quit_pending = 1;
1346                                 return;
1347                         }
1348                 }
1349                 /* Consume printed characters from the buffer. */
1350                 buffer_consume(&stderr_buffer, len);
1351                 stderr_bytes += len;
1352         }
1353 }
1354
1355 /*
1356  * Get packets from the connection input buffer, and process them as long as
1357  * there are packets available.
1358  *
1359  * Any unknown packets received during the actual
1360  * session cause the session to terminate.  This is
1361  * intended to make debugging easier since no
1362  * confirmations are sent.  Any compatible protocol
1363  * extensions must be negotiated during the
1364  * preparatory phase.
1365  */
1366
1367 static void
1368 client_process_buffered_input_packets(void)
1369 {
1370         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1371 }
1372
1373 /* scan buf[] for '~' before sending data to the peer */
1374
1375 static int
1376 simple_escape_filter(Channel *c, char *buf, int len)
1377 {
1378         /* XXX we assume c->extended is writeable */
1379         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1380 }
1381
1382 static void
1383 client_channel_closed(int id, void *arg)
1384 {
1385         channel_cancel_cleanup(id);
1386         session_closed = 1;
1387         leave_raw_mode();
1388 }
1389
1390 /*
1391  * Implements the interactive session with the server.  This is called after
1392  * the user has been authenticated, and a command has been started on the
1393  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1394  * used as an escape character for terminating or suspending the session.
1395  */
1396
1397 int
1398 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1399 {
1400         fd_set *readset = NULL, *writeset = NULL;
1401         double start_time, total_time;
1402         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1403         u_int nalloc = 0;
1404         char buf[100];
1405
1406         debug("Entering interactive session.");
1407
1408         start_time = get_current_time();
1409
1410         /* Initialize variables. */
1411         escape_pending = 0;
1412         last_was_cr = 1;
1413         exit_status = -1;
1414         stdin_eof = 0;
1415         buffer_high = 64 * 1024;
1416         connection_in = packet_get_connection_in();
1417         connection_out = packet_get_connection_out();
1418         max_fd = MAX(connection_in, connection_out);
1419         if (control_fd != -1)
1420                 max_fd = MAX(max_fd, control_fd);
1421
1422         if (!compat20) {
1423                 /* enable nonblocking unless tty */
1424                 if (!isatty(fileno(stdin)))
1425                         set_nonblock(fileno(stdin));
1426                 if (!isatty(fileno(stdout)))
1427                         set_nonblock(fileno(stdout));
1428                 if (!isatty(fileno(stderr)))
1429                         set_nonblock(fileno(stderr));
1430                 max_fd = MAX(max_fd, fileno(stdin));
1431                 max_fd = MAX(max_fd, fileno(stdout));
1432                 max_fd = MAX(max_fd, fileno(stderr));
1433         }
1434         stdin_bytes = 0;
1435         stdout_bytes = 0;
1436         stderr_bytes = 0;
1437         quit_pending = 0;
1438         escape_char = escape_char_arg;
1439
1440         /* Initialize buffers. */
1441         buffer_init(&stdin_buffer);
1442         buffer_init(&stdout_buffer);
1443         buffer_init(&stderr_buffer);
1444
1445         client_init_dispatch();
1446
1447         /*
1448          * Set signal handlers, (e.g. to restore non-blocking mode)
1449          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1450          */
1451         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1452                 signal(SIGHUP, signal_handler);
1453         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1454                 signal(SIGINT, signal_handler);
1455         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1456                 signal(SIGQUIT, signal_handler);
1457         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1458                 signal(SIGTERM, signal_handler);
1459         signal(SIGWINCH, window_change_handler);
1460
1461         if (have_pty)
1462                 enter_raw_mode();
1463
1464         if (compat20) {
1465                 session_ident = ssh2_chan_id;
1466                 if (escape_char != SSH_ESCAPECHAR_NONE)
1467                         channel_register_filter(session_ident,
1468                             simple_escape_filter, NULL);
1469                 if (session_ident != -1)
1470                         channel_register_cleanup(session_ident,
1471                             client_channel_closed, 0);
1472         } else {
1473                 /* Check if we should immediately send eof on stdin. */
1474                 client_check_initial_eof_on_stdin();
1475         }
1476
1477         /* Main loop of the client for the interactive session mode. */
1478         while (!quit_pending) {
1479
1480                 /* Process buffered packets sent by the server. */
1481                 client_process_buffered_input_packets();
1482
1483                 if (compat20 && session_closed && !channel_still_open())
1484                         break;
1485
1486                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1487
1488                 if (rekeying) {
1489                         debug("rekeying in progress");
1490                 } else {
1491                         /*
1492                          * Make packets of buffered stdin data, and buffer
1493                          * them for sending to the server.
1494                          */
1495                         if (!compat20)
1496                                 client_make_packets_from_stdin_data();
1497
1498                         /*
1499                          * Make packets from buffered channel data, and
1500                          * enqueue them for sending to the server.
1501                          */
1502                         if (packet_not_very_much_data_to_write())
1503                                 channel_output_poll();
1504
1505                         /*
1506                          * Check if the window size has changed, and buffer a
1507                          * message about it to the server if so.
1508                          */
1509                         client_check_window_change();
1510
1511                         if (quit_pending)
1512                                 break;
1513                 }
1514                 /*
1515                  * Wait until we have something to do (something becomes
1516                  * available on one of the descriptors).
1517                  */
1518                 max_fd2 = max_fd;
1519                 client_wait_until_can_do_something(&readset, &writeset,
1520                     &max_fd2, &nalloc, rekeying);
1521
1522                 if (quit_pending)
1523                         break;
1524
1525                 /* Do channel operations unless rekeying in progress. */
1526                 if (!rekeying) {
1527                         channel_after_select(readset, writeset);
1528                         if (need_rekeying || packet_need_rekeying()) {
1529                                 debug("need rekeying");
1530                                 xxx_kex->done = 0;
1531                                 kex_send_kexinit(xxx_kex);
1532                                 need_rekeying = 0;
1533                         }
1534                 }
1535
1536                 /* Buffer input from the connection.  */
1537                 client_process_net_input(readset);
1538
1539                 /* Accept control connections.  */
1540                 client_process_control(readset);
1541
1542                 if (quit_pending)
1543                         break;
1544
1545                 if (!compat20) {
1546                         /* Buffer data from stdin */
1547                         client_process_input(readset);
1548                         /*
1549                          * Process output to stdout and stderr.  Output to
1550                          * the connection is processed elsewhere (above).
1551                          */
1552                         client_process_output(writeset);
1553                 }
1554
1555                 /* Send as much buffered packet data as possible to the sender. */
1556                 if (FD_ISSET(connection_out, writeset))
1557                         packet_write_poll();
1558         }
1559         if (readset)
1560                 xfree(readset);
1561         if (writeset)
1562                 xfree(writeset);
1563
1564         /* Terminate the session. */
1565
1566         /* Stop watching for window change. */
1567         signal(SIGWINCH, SIG_DFL);
1568
1569         channel_free_all();
1570
1571         if (have_pty)
1572                 leave_raw_mode();
1573
1574         /* restore blocking io */
1575         if (!isatty(fileno(stdin)))
1576                 unset_nonblock(fileno(stdin));
1577         if (!isatty(fileno(stdout)))
1578                 unset_nonblock(fileno(stdout));
1579         if (!isatty(fileno(stderr)))
1580                 unset_nonblock(fileno(stderr));
1581
1582         /*
1583          * If there was no shell or command requested, there will be no remote
1584          * exit status to be returned.  In that case, clear error code if the
1585          * connection was deliberately terminated at this end.
1586          */
1587         if (no_shell_flag && received_signal == SIGTERM) {
1588                 received_signal = 0;
1589                 exit_status = 0;
1590         }
1591
1592         if (received_signal)
1593                 fatal("Killed by signal %d.", (int) received_signal);
1594
1595         /*
1596          * In interactive mode (with pseudo tty) display a message indicating
1597          * that the connection has been closed.
1598          */
1599         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1600                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1601                 buffer_append(&stderr_buffer, buf, strlen(buf));
1602         }
1603
1604         /* Output any buffered data for stdout. */
1605         while (buffer_len(&stdout_buffer) > 0) {
1606                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1607                     buffer_len(&stdout_buffer));
1608                 if (len <= 0) {
1609                         error("Write failed flushing stdout buffer.");
1610                         break;
1611                 }
1612                 buffer_consume(&stdout_buffer, len);
1613                 stdout_bytes += len;
1614         }
1615
1616         /* Output any buffered data for stderr. */
1617         while (buffer_len(&stderr_buffer) > 0) {
1618                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1619                     buffer_len(&stderr_buffer));
1620                 if (len <= 0) {
1621                         error("Write failed flushing stderr buffer.");
1622                         break;
1623                 }
1624                 buffer_consume(&stderr_buffer, len);
1625                 stderr_bytes += len;
1626         }
1627
1628         /* Clear and free any buffers. */
1629         memset(buf, 0, sizeof(buf));
1630         buffer_free(&stdin_buffer);
1631         buffer_free(&stdout_buffer);
1632         buffer_free(&stderr_buffer);
1633
1634         /* Report bytes transferred, and transfer rates. */
1635         total_time = get_current_time() - start_time;
1636         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1637             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1638         if (total_time > 0)
1639                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1640                     stdin_bytes / total_time, stdout_bytes / total_time,
1641                     stderr_bytes / total_time);
1642
1643         /* Return the exit status of the program. */
1644         debug("Exit status %d", exit_status);
1645         return exit_status;
1646 }
1647
1648 /*********/
1649
1650 static void
1651 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1652 {
1653         u_int data_len;
1654         char *data = packet_get_string(&data_len);
1655         packet_check_eom();
1656         buffer_append(&stdout_buffer, data, data_len);
1657         memset(data, 0, data_len);
1658         xfree(data);
1659 }
1660 static void
1661 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1662 {
1663         u_int data_len;
1664         char *data = packet_get_string(&data_len);
1665         packet_check_eom();
1666         buffer_append(&stderr_buffer, data, data_len);
1667         memset(data, 0, data_len);
1668         xfree(data);
1669 }
1670 static void
1671 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1672 {
1673         exit_status = packet_get_int();
1674         packet_check_eom();
1675         /* Acknowledge the exit. */
1676         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1677         packet_send();
1678         /*
1679          * Must wait for packet to be sent since we are
1680          * exiting the loop.
1681          */
1682         packet_write_wait();
1683         /* Flag that we want to exit. */
1684         quit_pending = 1;
1685 }
1686 static void
1687 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1688 {
1689         Channel *c = NULL;
1690         int remote_id, sock;
1691
1692         /* Read the remote channel number from the message. */
1693         remote_id = packet_get_int();
1694         packet_check_eom();
1695
1696         /*
1697          * Get a connection to the local authentication agent (this may again
1698          * get forwarded).
1699          */
1700         sock = ssh_get_authentication_socket();
1701
1702         /*
1703          * If we could not connect the agent, send an error message back to
1704          * the server. This should never happen unless the agent dies,
1705          * because authentication forwarding is only enabled if we have an
1706          * agent.
1707          */
1708         if (sock >= 0) {
1709                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1710                     -1, 0, 0, 0, "authentication agent connection", 1);
1711                 c->remote_id = remote_id;
1712                 c->force_drain = 1;
1713         }
1714         if (c == NULL) {
1715                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1716                 packet_put_int(remote_id);
1717         } else {
1718                 /* Send a confirmation to the remote host. */
1719                 debug("Forwarding authentication connection.");
1720                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1721                 packet_put_int(remote_id);
1722                 packet_put_int(c->self);
1723         }
1724         packet_send();
1725 }
1726
1727 static Channel *
1728 client_request_forwarded_tcpip(const char *request_type, int rchan)
1729 {
1730         Channel *c = NULL;
1731         char *listen_address, *originator_address;
1732         int listen_port, originator_port;
1733         int sock;
1734
1735         /* Get rest of the packet */
1736         listen_address = packet_get_string(NULL);
1737         listen_port = packet_get_int();
1738         originator_address = packet_get_string(NULL);
1739         originator_port = packet_get_int();
1740         packet_check_eom();
1741
1742         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1743             listen_address, listen_port, originator_address, originator_port);
1744
1745         sock = channel_connect_by_listen_address(listen_port);
1746         if (sock < 0) {
1747                 xfree(originator_address);
1748                 xfree(listen_address);
1749                 return NULL;
1750         }
1751         if (options.hpn_disabled)
1752                 c = channel_new("forwarded-tcpip",
1753                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1754                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1755                     originator_address, 1);
1756         else
1757                 c = channel_new("forwarded-tcpip",
1758                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1759                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1760                     originator_address, 1);
1761         xfree(originator_address);
1762         xfree(listen_address);
1763         return c;
1764 }
1765
1766 static Channel *
1767 client_request_x11(const char *request_type, int rchan)
1768 {
1769         Channel *c = NULL;
1770         char *originator;
1771         int originator_port;
1772         int sock;
1773
1774         if (!options.forward_x11) {
1775                 error("Warning: ssh server tried X11 forwarding.");
1776                 error("Warning: this is probably a break-in attempt by a malicious server.");
1777                 return NULL;
1778         }
1779         originator = packet_get_string(NULL);
1780         if (datafellows & SSH_BUG_X11FWD) {
1781                 debug2("buggy server: x11 request w/o originator_port");
1782                 originator_port = 0;
1783         } else {
1784                 originator_port = packet_get_int();
1785         }
1786         packet_check_eom();
1787         /* XXX check permission */
1788         debug("client_request_x11: request from %s %d", originator,
1789             originator_port);
1790         xfree(originator);
1791         sock = x11_connect_display();
1792         if (sock < 0)
1793                 return NULL;
1794         if (options.hpn_disabled)
1795                 c = channel_new("x11",
1796                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1797                     CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1798         else
1799                 c = channel_new("x11",
1800                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1801                     options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1802         c->force_drain = 1;
1803         return c;
1804 }
1805
1806 static Channel *
1807 client_request_agent(const char *request_type, int rchan)
1808 {
1809         Channel *c = NULL;
1810         int sock;
1811
1812         if (!options.forward_agent) {
1813                 error("Warning: ssh server tried agent forwarding.");
1814                 error("Warning: this is probably a break-in attempt by a malicious server.");
1815                 return NULL;
1816         }
1817         sock = ssh_get_authentication_socket();
1818         if (sock < 0)
1819                 return NULL;
1820         if (options.hpn_disabled)
1821                 c = channel_new("authentication agent connection",
1822                     SSH_CHANNEL_OPEN, sock, sock, -1,
1823                     CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1824                     "authentication agent connection", 1);
1825         else
1826                 c = channel_new("authentication agent connection",
1827                     SSH_CHANNEL_OPEN, sock, sock, -1,
1828                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1829                     "authentication agent connection", 1);
1830         c->force_drain = 1;
1831         return c;
1832 }
1833
1834 /* XXXX move to generic input handler */
1835 static void
1836 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1837 {
1838         Channel *c = NULL;
1839         char *ctype;
1840         int rchan;
1841         u_int rmaxpack, rwindow, len;
1842
1843         ctype = packet_get_string(&len);
1844         rchan = packet_get_int();
1845         rwindow = packet_get_int();
1846         rmaxpack = packet_get_int();
1847
1848         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1849             ctype, rchan, rwindow, rmaxpack);
1850
1851         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1852                 c = client_request_forwarded_tcpip(ctype, rchan);
1853         } else if (strcmp(ctype, "x11") == 0) {
1854                 c = client_request_x11(ctype, rchan);
1855         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1856                 c = client_request_agent(ctype, rchan);
1857         }
1858 /* XXX duplicate : */
1859         if (c != NULL) {
1860                 debug("confirm %s", ctype);
1861                 c->remote_id = rchan;
1862                 c->remote_window = rwindow;
1863                 c->remote_maxpacket = rmaxpack;
1864                 if (c->type != SSH_CHANNEL_CONNECTING) {
1865                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1866                         packet_put_int(c->remote_id);
1867                         packet_put_int(c->self);
1868                         packet_put_int(c->local_window);
1869                         packet_put_int(c->local_maxpacket);
1870                         packet_send();
1871                 }
1872         } else {
1873                 debug("failure %s", ctype);
1874                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1875                 packet_put_int(rchan);
1876                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1877                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1878                         packet_put_cstring("open failed");
1879                         packet_put_cstring("");
1880                 }
1881                 packet_send();
1882         }
1883         xfree(ctype);
1884 }
1885 static void
1886 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1887 {
1888         Channel *c = NULL;
1889         int exitval, id, reply, success = 0;
1890         char *rtype;
1891
1892         id = packet_get_int();
1893         rtype = packet_get_string(NULL);
1894         reply = packet_get_char();
1895
1896         debug("client_input_channel_req: channel %d rtype %s reply %d",
1897             id, rtype, reply);
1898
1899         if (id == -1) {
1900                 error("client_input_channel_req: request for channel -1");
1901         } else if ((c = channel_lookup(id)) == NULL) {
1902                 error("client_input_channel_req: channel %d: unknown channel", id);
1903         } else if (strcmp(rtype, "exit-status") == 0) {
1904                 exitval = packet_get_int();
1905                 if (id == session_ident) {
1906                         success = 1;
1907                         exit_status = exitval;
1908                 } else if (c->ctl_fd == -1) {
1909                         error("client_input_channel_req: unexpected channel %d",
1910                             session_ident);
1911                 } else {
1912                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1913                         success = 1;
1914                 }
1915                 packet_check_eom();
1916         }
1917         if (reply) {
1918                 packet_start(success ?
1919                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1920                 packet_put_int(id);
1921                 packet_send();
1922         }
1923         xfree(rtype);
1924 }
1925 static void
1926 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1927 {
1928         char *rtype;
1929         int want_reply;
1930         int success = 0;
1931
1932         rtype = packet_get_string(NULL);
1933         want_reply = packet_get_char();
1934         debug("client_input_global_request: rtype %s want_reply %d",
1935             rtype, want_reply);
1936         if (want_reply) {
1937                 packet_start(success ?
1938                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1939                 packet_send();
1940                 packet_write_wait();
1941         }
1942         xfree(rtype);
1943 }
1944
1945 void
1946 client_session2_setup(int id, int want_tty, int want_subsystem,
1947     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1948     dispatch_fn *subsys_repl)
1949 {
1950         int len;
1951         Channel *c = NULL;
1952
1953         debug2("%s: id %d", __func__, id);
1954
1955         if ((c = channel_lookup(id)) == NULL)
1956                 fatal("client_session2_setup: channel %d: unknown channel", id);
1957
1958         if (want_tty) {
1959                 struct winsize ws;
1960                 struct termios tio;
1961
1962                 /* Store window size in the packet. */
1963                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1964                         memset(&ws, 0, sizeof(ws));
1965
1966                 channel_request_start(id, "pty-req", 0);
1967                 packet_put_cstring(term != NULL ? term : "");
1968                 packet_put_int((u_int)ws.ws_col);
1969                 packet_put_int((u_int)ws.ws_row);
1970                 packet_put_int((u_int)ws.ws_xpixel);
1971                 packet_put_int((u_int)ws.ws_ypixel);
1972                 tio = get_saved_tio();
1973                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1974                 packet_send();
1975                 /* XXX wait for reply */
1976                 c->client_tty = 1;
1977         }
1978
1979         /* Transfer any environment variables from client to server */
1980         if (options.num_send_env != 0 && env != NULL) {
1981                 int i, j, matched;
1982                 char *name, *val;
1983
1984                 debug("Sending environment.");
1985                 for (i = 0; env[i] != NULL; i++) {
1986                         /* Split */
1987                         name = xstrdup(env[i]);
1988                         if ((val = strchr(name, '=')) == NULL) {
1989                                 xfree(name);
1990                                 continue;
1991                         }
1992                         *val++ = '\0';
1993
1994                         matched = 0;
1995                         for (j = 0; j < options.num_send_env; j++) {
1996                                 if (match_pattern(name, options.send_env[j])) {
1997                                         matched = 1;
1998                                         break;
1999                                 }
2000                         }
2001                         if (!matched) {
2002                                 debug3("Ignored env %s", name);
2003                                 xfree(name);
2004                                 continue;
2005                         }
2006
2007                         debug("Sending env %s = %s", name, val);
2008                         channel_request_start(id, "env", 0);
2009                         packet_put_cstring(name);
2010                         packet_put_cstring(val);
2011                         packet_send();
2012                         xfree(name);
2013                 }
2014         }
2015
2016         len = buffer_len(cmd);
2017         if (len > 0) {
2018                 if (len > 900)
2019                         len = 900;
2020                 if (want_subsystem) {
2021                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
2022                         channel_request_start(id, "subsystem", subsys_repl != NULL);
2023                         if (subsys_repl != NULL) {
2024                                 /* register callback for reply */
2025                                 /* XXX we assume that client_loop has already been called */
2026                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
2027                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
2028                         }
2029                 } else {
2030                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
2031                         channel_request_start(id, "exec", 0);
2032                 }
2033                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2034                 packet_send();
2035         } else {
2036                 channel_request_start(id, "shell", 0);
2037                 packet_send();
2038         }
2039 }
2040
2041 static void
2042 client_init_dispatch_20(void)
2043 {
2044         dispatch_init(&dispatch_protocol_error);
2045
2046         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2047         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2048         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2049         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2050         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2051         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2052         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2053         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2054         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2055         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2056
2057         /* rekeying */
2058         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2059
2060         /* global request reply messages */
2061         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2062         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2063 }
2064 static void
2065 client_init_dispatch_13(void)
2066 {
2067         dispatch_init(NULL);
2068         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2069         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2070         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2071         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2072         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2073         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2074         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2075         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2076         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2077
2078         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2079             &client_input_agent_open : &deny_input_open);
2080         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2081             &x11_input_open : &deny_input_open);
2082 }
2083 static void
2084 client_init_dispatch_15(void)
2085 {
2086         client_init_dispatch_13();
2087         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2088         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2089 }
2090 static void
2091 client_init_dispatch(void)
2092 {
2093         if (compat20)
2094                 client_init_dispatch_20();
2095         else if (compat13)
2096                 client_init_dispatch_13();
2097         else
2098                 client_init_dispatch_15();
2099 }
2100
2101 /* client specific fatal cleanup */
2102 void
2103 cleanup_exit(int i)
2104 {
2105         leave_raw_mode();
2106         leave_non_blocking();
2107         if (options.control_path != NULL && control_fd != -1)
2108                 unlink(options.control_path);
2109         _exit(i);
2110 }