ssh.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Ssh client program.  This program can be used to log into a remote machine.
   6  * The software supports strong authentication, encryption, and forwarding
   7  * of X11, TCP/IP, and authentication connections.
   8  *
   9  * As far as I am concerned, the code I have written for this software
  10  * can be used freely for any purpose.  Any derived versions of this
  11  * software must be clearly marked as such, and if the derived work is
  12  * incompatible with the protocol description in the RFC file, it must be
  13  * called by a name other than "ssh" or "Secure Shell".
  14  *
  15  * Copyright (c) 1999 Niels Provos.  All rights reserved.
  16  * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl.  All rights reserved.
  17  *
  18  * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
  19  * in Canada (German citizen).
  20  *
  21  * Redistribution and use in source and binary forms, with or without
  22  * modification, are permitted provided that the following conditions
  23  * are met:
  24  * 1. Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  * 2. Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in the
  28  *    documentation and/or other materials provided with the distribution.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  32  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  33  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  34  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  35  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  39  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 #include "includes.h"
  43 RCSID("$OpenBSD: ssh.c,v 1.222 2004/06/23 14:31:01 dtucker Exp $");
  44
  45 #include <openssl/evp.h>
  46 #include <openssl/err.h>
  47
  48 #include "ssh.h"
  49 #include "ssh1.h"
  50 #include "ssh2.h"
  51 #include "compat.h"
  52 #include "cipher.h"
  53 #include "xmalloc.h"
  54 #include "packet.h"
  55 #include "buffer.h"
  56 #include "bufaux.h"
  57 #include "channels.h"
  58 #include "key.h"
  59 #include "authfd.h"
  60 #include "authfile.h"
  61 #include "pathnames.h"
  62 #include "dispatch.h"
  63 #include "clientloop.h"
  64 #include "log.h"
  65 #include "readconf.h"
  66 #include "sshconnect.h"
  67 #include "misc.h"
  68 #include "kex.h"
  69 #include "mac.h"
  70 #include "sshpty.h"
  71 #include "match.h"
  72 #include "msg.h"
  73 #include "monitor_fdpass.h"
  74
  75 #ifdef SMARTCARD
  76 #include "scard.h"
  77 #endif
  78
  79 #ifdef HAVE___PROGNAME
  80 extern char *__progname;
  81 #else
  82 char *__progname;
  83 #endif
  84
  85 /* Flag indicating whether debug mode is on.  This can be set on the command line. */
  86 int debug_flag = 0;
  87
  88 /* Flag indicating whether a tty should be allocated */
  89 int tty_flag = 0;
  90 int no_tty_flag = 0;
  91 int force_tty_flag = 0;
  92
  93 /* don't exec a shell */
  94 int no_shell_flag = 0;
  95
  96 /*
  97  * Flag indicating that nothing should be read from stdin.  This can be set
  98  * on the command line.
  99  */
 100 int stdin_null_flag = 0;
 101
 102 /*
 103  * Flag indicating that ssh should fork after authentication.  This is useful
 104  * so that the passphrase can be entered manually, and then ssh goes to the
 105  * background.
 106  */
 107 int fork_after_authentication_flag = 0;
 108
 109 /*
 110  * General data structure for command line options and options configurable
 111  * in configuration files.  See readconf.h.
 112  */
 113 Options options;
 114
 115 /* optional user configfile */
 116 char *config = NULL;
 117
 118 /*
 119  * Name of the host we are connecting to.  This is the name given on the
 120  * command line, or the HostName specified for the user-supplied name in a
 121  * configuration file.
 122  */
 123 char *host;
 124
 125 /* socket address the host resolves to */
 126 struct sockaddr_storage hostaddr;
 127
 128 /* Private host keys. */
 129 Sensitive sensitive_data;
 130
 131 /* Original real UID. */
 132 uid_t original_real_uid;
 133 uid_t original_effective_uid;
 134
 135 /* command to be executed */
 136 Buffer command;
 137
 138 /* Should we execute a command or invoke a subsystem? */
 139 int subsystem_flag = 0;
 140
 141 /* # of replies received for global requests */
 142 static int client_global_request_id = 0;
 143
 144 /* pid of proxycommand child process */
 145 pid_t proxy_command_pid = 0;
 146
 147 /* fd to control socket */
 148 int control_fd = -1;
 149
 150 /* Only used in control client mode */
 151 volatile sig_atomic_t control_client_terminate = 0;
 152 u_int control_server_pid = 0;
 153
 154 /* Prints a help message to the user.  This function never returns. */
 155
 156 static void
 157 usage(void)
 158 {
 159         fprintf(stderr,
 160 "usage: ssh [-1246AaCfghkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
 161 "           [-D port] [-e escape_char] [-F configfile] [-i identity_file]\n"
 162 "           [-L port:host:hostport] [-l login_name] [-m mac_spec] [-o option]\n"
 163 "           [-p port] [-R port:host:hostport] [-S ctl] [user@]hostname [command]\n"
 164         );
 165         exit(1);
 166 }
 167
 168 static int ssh_session(void);
 169 static int ssh_session2(void);
 170 static void load_public_identity_files(void);
 171 static void control_client(const char *path);
 172
 173 /*
 174  * Main program for the ssh client.
 175  */
 176 int
 177 main(int ac, char **av)
 178 {
 179         int i, opt, exit_status;
 180         u_short fwd_port, fwd_host_port;
 181         char sfwd_port[6], sfwd_host_port[6];
 182         char *p, *cp, *line, buf[256];
 183         struct stat st;
 184         struct passwd *pw;
 185         int dummy;
 186         extern int optind, optreset;
 187         extern char *optarg;
 188
 189         __progname = ssh_get_progname(av[0]);
 190         init_rng();
 191
 192         /*
 193          * Save the original real uid.  It will be needed later (uid-swapping
 194          * may clobber the real uid).
 195          */
 196         original_real_uid = getuid();
 197         original_effective_uid = geteuid();
 198
 199         /*
 200          * Use uid-swapping to give up root privileges for the duration of
 201          * option processing.  We will re-instantiate the rights when we are
 202          * ready to create the privileged port, and will permanently drop
 203          * them when the port has been created (actually, when the connection
 204          * has been made, as we may need to create the port several times).
 205          */
 206         PRIV_END;
 207
 208 #ifdef HAVE_SETRLIMIT
 209         /* If we are installed setuid root be careful to not drop core. */
 210         if (original_real_uid != original_effective_uid) {
 211                 struct rlimit rlim;
 212                 rlim.rlim_cur = rlim.rlim_max = 0;
 213                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 214                         fatal("setrlimit failed: %.100s", strerror(errno));
 215         }
 216 #endif
 217         /* Get user data. */
 218         pw = getpwuid(original_real_uid);
 219         if (!pw) {
 220                 logit("You don't exist, go away!");
 221                 exit(1);
 222         }
 223         /* Take a copy of the returned structure. */
 224         pw = pwcopy(pw);
 225
 226         /*
 227          * Set our umask to something reasonable, as some files are created
 228          * with the default umask.  This will make them world-readable but
 229          * writable only by the owner, which is ok for all files for which we
 230          * don't set the modes explicitly.
 231          */
 232         umask(022);
 233
 234         /* Initialize option structure to indicate that no values have been set. */
 235         initialize_options(&options);
 236
 237         /* Parse command-line arguments. */
 238         host = NULL;
 239
 240 again:
 241         while ((opt = getopt(ac, av,
 242             "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNPR:S:TVXY")) != -1) {
 243                 switch (opt) {
 244                 case '1':
 245                         options.protocol = SSH_PROTO_1;
 246                         break;
 247                 case '2':
 248                         options.protocol = SSH_PROTO_2;
 249                         break;
 250                 case '4':
 251                         options.address_family = AF_INET;
 252                         break;
 253                 case '6':
 254                         options.address_family = AF_INET6;
 255                         break;
 256                 case 'n':
 257                         stdin_null_flag = 1;
 258                         break;
 259                 case 'f':
 260                         fork_after_authentication_flag = 1;
 261                         stdin_null_flag = 1;
 262                         break;
 263                 case 'x':
 264                         options.forward_x11 = 0;
 265                         break;
 266                 case 'X':
 267                         options.forward_x11 = 1;
 268                         break;
 269                 case 'Y':
 270                         options.forward_x11 = 1;
 271                         options.forward_x11_trusted = 1;
 272                         break;
 273                 case 'g':
 274                         options.gateway_ports = 1;
 275                         break;
 276                 case 'P':       /* deprecated */
 277                         options.use_privileged_port = 0;
 278                         break;
 279                 case 'a':
 280                         options.forward_agent = 0;
 281                         break;
 282                 case 'A':
 283                         options.forward_agent = 1;
 284                         break;
 285                 case 'k':
 286                         options.gss_deleg_creds = 0;
 287                         break;
 288                 case 'i':
 289                         if (stat(optarg, &st) < 0) {
 290                                 fprintf(stderr, "Warning: Identity file %s "
 291                                     "does not exist.\n", optarg);
 292                                 break;
 293                         }
 294                         if (options.num_identity_files >=
 295                             SSH_MAX_IDENTITY_FILES)
 296                                 fatal("Too many identity files specified "
 297                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 298                         options.identity_files[options.num_identity_files++] =
 299                             xstrdup(optarg);
 300                         break;
 301                 case 'I':
 302 #ifdef SMARTCARD
 303                         options.smartcard_device = xstrdup(optarg);
 304 #else
 305                         fprintf(stderr, "no support for smartcards.\n");
 306 #endif
 307                         break;
 308                 case 't':
 309                         if (tty_flag)
 310                                 force_tty_flag = 1;
 311                         tty_flag = 1;
 312                         break;
 313                 case 'v':
 314                         if (debug_flag == 0) {
 315                                 debug_flag = 1;
 316                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 317                         } else {
 318                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 319                                         options.log_level++;
 320                                 break;
 321                         }
 322                         /* fallthrough */
 323                 case 'V':
 324                         fprintf(stderr, "%s, %s\n",
 325                             SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
 326                         if (opt == 'V')
 327                                 exit(0);
 328                         break;
 329                 case 'q':
 330                         options.log_level = SYSLOG_LEVEL_QUIET;
 331                         break;
 332                 case 'e':
 333                         if (optarg[0] == '^' && optarg[2] == 0 &&
 334                             (u_char) optarg[1] >= 64 &&
 335                             (u_char) optarg[1] < 128)
 336                                 options.escape_char = (u_char) optarg[1] & 31;
 337                         else if (strlen(optarg) == 1)
 338                                 options.escape_char = (u_char) optarg[0];
 339                         else if (strcmp(optarg, "none") == 0)
 340                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 341                         else {
 342                                 fprintf(stderr, "Bad escape character '%s'.\n",
 343                                     optarg);
 344                                 exit(1);
 345                         }
 346                         break;
 347                 case 'c':
 348                         if (ciphers_valid(optarg)) {
 349                                 /* SSH2 only */
 350                                 options.ciphers = xstrdup(optarg);
 351                                 options.cipher = SSH_CIPHER_ILLEGAL;
 352                         } else {
 353                                 /* SSH1 only */
 354                                 options.cipher = cipher_number(optarg);
 355                                 if (options.cipher == -1) {
 356                                         fprintf(stderr,
 357                                             "Unknown cipher type '%s'\n",
 358                                             optarg);
 359                                         exit(1);
 360                                 }
 361                                 if (options.cipher == SSH_CIPHER_3DES)
 362                                         options.ciphers = "3des-cbc";
 363                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 364                                         options.ciphers = "blowfish-cbc";
 365                                 else
 366                                         options.ciphers = (char *)-1;
 367                         }
 368                         break;
 369                 case 'm':
 370                         if (mac_valid(optarg))
 371                                 options.macs = xstrdup(optarg);
 372                         else {
 373                                 fprintf(stderr, "Unknown mac type '%s'\n",
 374                                     optarg);
 375                                 exit(1);
 376                         }
 377                         break;
 378                 case 'M':
 379                         options.control_master =
 380                             (options.control_master >= 1) ? 2 : 1;
 381                         break;
 382                 case 'p':
 383                         options.port = a2port(optarg);
 384                         if (options.port == 0) {
 385                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 386                                 exit(1);
 387                         }
 388                         break;
 389                 case 'l':
 390                         options.user = optarg;
 391                         break;
 392
 393                 case 'L':
 394                 case 'R':
 395                         if (sscanf(optarg, "%5[0123456789]:%255[^:]:%5[0123456789]",
 396                             sfwd_port, buf, sfwd_host_port) != 3 &&
 397                             sscanf(optarg, "%5[0123456789]/%255[^/]/%5[0123456789]",
 398                             sfwd_port, buf, sfwd_host_port) != 3) {
 399                                 fprintf(stderr,
 400                                     "Bad forwarding specification '%s'\n",
 401                                     optarg);
 402                                 usage();
 403                                 /* NOTREACHED */
 404                         }
 405                         if ((fwd_port = a2port(sfwd_port)) == 0 ||
 406                             (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 407                                 fprintf(stderr,
 408                                     "Bad forwarding port(s) '%s'\n", optarg);
 409                                 exit(1);
 410                         }
 411                         if (opt == 'L')
 412                                 add_local_forward(&options, fwd_port, buf,
 413                                     fwd_host_port);
 414                         else if (opt == 'R')
 415                                 add_remote_forward(&options, fwd_port, buf,
 416                                     fwd_host_port);
 417                         break;
 418
 419                 case 'D':
 420                         fwd_port = a2port(optarg);
 421                         if (fwd_port == 0) {
 422                                 fprintf(stderr, "Bad dynamic port '%s'\n",
 423                                     optarg);
 424                                 exit(1);
 425                         }
 426                         add_local_forward(&options, fwd_port, "socks", 0);
 427                         break;
 428
 429                 case 'C':
 430                         options.compression = 1;
 431                         break;
 432                 case 'N':
 433                         no_shell_flag = 1;
 434                         no_tty_flag = 1;
 435                         break;
 436                 case 'T':
 437                         no_tty_flag = 1;
 438                         break;
 439                 case 'o':
 440                         dummy = 1;
 441                         line = xstrdup(optarg);
 442                         if (process_config_line(&options, host ? host : "",
 443                             line, "command-line", 0, &dummy) != 0)
 444                                 exit(1);
 445                         xfree(line);
 446                         break;
 447                 case 's':
 448                         subsystem_flag = 1;
 449                         break;
 450                 case 'S':
 451                         if (options.control_path != NULL)
 452                                 free(options.control_path);
 453                         options.control_path = xstrdup(optarg);
 454                         break;
 455                 case 'b':
 456                         options.bind_address = optarg;
 457                         break;
 458                 case 'F':
 459                         config = optarg;
 460                         break;
 461                 default:
 462                         usage();
 463                 }
 464         }
 465
 466         ac -= optind;
 467         av += optind;
 468
 469         if (ac > 0 && !host && **av != '-') {
 470                 if (strrchr(*av, '@')) {
 471                         p = xstrdup(*av);
 472                         cp = strrchr(p, '@');
 473                         if (cp == NULL || cp == p)
 474                                 usage();
 475                         options.user = p;
 476                         *cp = '\0';
 477                         host = ++cp;
 478                 } else
 479                         host = *av;
 480                 if (ac > 1) {
 481                         optind = optreset = 1;
 482                         goto again;
 483                 }
 484                 ac--, av++;
 485         }
 486
 487         /* Check that we got a host name. */
 488         if (!host)
 489                 usage();
 490
 491         SSLeay_add_all_algorithms();
 492         ERR_load_crypto_strings();
 493
 494         /* Initialize the command to execute on remote host. */
 495         buffer_init(&command);
 496
 497         /*
 498          * Save the command to execute on the remote host in a buffer. There
 499          * is no limit on the length of the command, except by the maximum
 500          * packet size.  Also sets the tty flag if there is no command.
 501          */
 502         if (!ac) {
 503                 /* No command specified - execute shell on a tty. */
 504                 tty_flag = 1;
 505                 if (subsystem_flag) {
 506                         fprintf(stderr,
 507                             "You must specify a subsystem to invoke.\n");
 508                         usage();
 509                 }
 510         } else {
 511                 /* A command has been specified.  Store it into the buffer. */
 512                 for (i = 0; i < ac; i++) {
 513                         if (i)
 514                                 buffer_append(&command, " ", 1);
 515                         buffer_append(&command, av[i], strlen(av[i]));
 516                 }
 517         }
 518
 519         /* Cannot fork to background if no command. */
 520         if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
 521                 fatal("Cannot fork into background without a command to execute.");
 522
 523         /* Allocate a tty by default if no command specified. */
 524         if (buffer_len(&command) == 0)
 525                 tty_flag = 1;
 526
 527         /* Force no tty */
 528         if (no_tty_flag)
 529                 tty_flag = 0;
 530         /* Do not allocate a tty if stdin is not a tty. */
 531         if (!isatty(fileno(stdin)) && !force_tty_flag) {
 532                 if (tty_flag)
 533                         logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
 534                 tty_flag = 0;
 535         }
 536
 537         /*
 538          * Initialize "log" output.  Since we are the client all output
 539          * actually goes to stderr.
 540          */
 541         log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 542             SYSLOG_FACILITY_USER, 1);
 543
 544         /*
 545          * Read per-user configuration file.  Ignore the system wide config
 546          * file if the user specifies a config file on the command line.
 547          */
 548         if (config != NULL) {
 549                 if (!read_config_file(config, host, &options, 0))
 550                         fatal("Can't open user config file %.100s: "
 551                             "%.100s", config, strerror(errno));
 552         } else  {
 553                 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
 554                     _PATH_SSH_USER_CONFFILE);
 555                 (void)read_config_file(buf, host, &options, 1);
 556
 557                 /* Read systemwide configuration file after use config. */
 558                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 559                     &options, 0);
 560         }
 561
 562         /* Fill configuration defaults. */
 563         fill_default_options(&options);
 564
 565         channel_set_af(options.address_family);
 566
 567         /* reinit */
 568         log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
 569
 570         seed_rng();
 571
 572         if (options.user == NULL)
 573                 options.user = xstrdup(pw->pw_name);
 574
 575         if (options.hostname != NULL)
 576                 host = options.hostname;
 577
 578         /* force lowercase for hostkey matching */
 579         if (options.host_key_alias != NULL) {
 580                 for (p = options.host_key_alias; *p; p++)
 581                         if (isupper(*p))
 582                                 *p = tolower(*p);
 583         }
 584
 585         if (options.proxy_command != NULL &&
 586             strcmp(options.proxy_command, "none") == 0)
 587                 options.proxy_command = NULL;
 588
 589         if (options.control_path != NULL) {
 590                 options.control_path = tilde_expand_filename(
 591                    options.control_path, original_real_uid);
 592         }
 593         if (options.control_path != NULL && options.control_master == 0)
 594                 control_client(options.control_path); /* This doesn't return */
 595
 596         /* Open a connection to the remote host. */
 597         if (ssh_connect(host, &hostaddr, options.port,
 598             options.address_family, options.connection_attempts,
 599 #ifdef HAVE_CYGWIN
 600             options.use_privileged_port,
 601 #else
 602             original_effective_uid == 0 && options.use_privileged_port,
 603 #endif
 604             options.proxy_command) != 0)
 605                 exit(1);
 606
 607         /*
 608          * If we successfully made the connection, load the host private key
 609          * in case we will need it later for combined rsa-rhosts
 610          * authentication. This must be done before releasing extra
 611          * privileges, because the file is only readable by root.
 612          * If we cannot access the private keys, load the public keys
 613          * instead and try to execute the ssh-keysign helper instead.
 614          */
 615         sensitive_data.nkeys = 0;
 616         sensitive_data.keys = NULL;
 617         sensitive_data.external_keysign = 0;
 618         if (options.rhosts_rsa_authentication ||
 619             options.hostbased_authentication) {
 620                 sensitive_data.nkeys = 3;
 621                 sensitive_data.keys = xmalloc(sensitive_data.nkeys *
 622                     sizeof(Key));
 623
 624                 PRIV_START;
 625                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 626                     _PATH_HOST_KEY_FILE, "", NULL);
 627                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 628                     _PATH_HOST_DSA_KEY_FILE, "", NULL);
 629                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 630                     _PATH_HOST_RSA_KEY_FILE, "", NULL);
 631                 PRIV_END;
 632
 633                 if (options.hostbased_authentication == 1 &&
 634                     sensitive_data.keys[0] == NULL &&
 635                     sensitive_data.keys[1] == NULL &&
 636                     sensitive_data.keys[2] == NULL) {
 637                         sensitive_data.keys[1] = key_load_public(
 638                             _PATH_HOST_DSA_KEY_FILE, NULL);
 639                         sensitive_data.keys[2] = key_load_public(
 640                             _PATH_HOST_RSA_KEY_FILE, NULL);
 641                         sensitive_data.external_keysign = 1;
 642                 }
 643         }
 644         /*
 645          * Get rid of any extra privileges that we may have.  We will no
 646          * longer need them.  Also, extra privileges could make it very hard
 647          * to read identity files and other non-world-readable files from the
 648          * user's home directory if it happens to be on a NFS volume where
 649          * root is mapped to nobody.
 650          */
 651         seteuid(original_real_uid);
 652         setuid(original_real_uid);
 653
 654         /*
 655          * Now that we are back to our own permissions, create ~/.ssh
 656          * directory if it doesn\'t already exist.
 657          */
 658         snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 659         if (stat(buf, &st) < 0)
 660                 if (mkdir(buf, 0700) < 0)
 661                         error("Could not create directory '%.200s'.", buf);
 662
 663         /* load options.identity_files */
 664         load_public_identity_files();
 665
 666         /* Expand ~ in known host file names. */
 667         /* XXX mem-leaks: */
 668         options.system_hostfile =
 669             tilde_expand_filename(options.system_hostfile, original_real_uid);
 670         options.user_hostfile =
 671             tilde_expand_filename(options.user_hostfile, original_real_uid);
 672         options.system_hostfile2 =
 673             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 674         options.user_hostfile2 =
 675             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 676
 677         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 678
 679         /* Log into the remote system.  This never returns if the login fails. */
 680         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
 681
 682         /* We no longer need the private host keys.  Clear them now. */
 683         if (sensitive_data.nkeys != 0) {
 684                 for (i = 0; i < sensitive_data.nkeys; i++) {
 685                         if (sensitive_data.keys[i] != NULL) {
 686                                 /* Destroys contents safely */
 687                                 debug3("clear hostkey %d", i);
 688                                 key_free(sensitive_data.keys[i]);
 689                                 sensitive_data.keys[i] = NULL;
 690                         }
 691                 }
 692                 xfree(sensitive_data.keys);
 693         }
 694         for (i = 0; i < options.num_identity_files; i++) {
 695                 if (options.identity_files[i]) {
 696                         xfree(options.identity_files[i]);
 697                         options.identity_files[i] = NULL;
 698                 }
 699                 if (options.identity_keys[i]) {
 700                         key_free(options.identity_keys[i]);
 701                         options.identity_keys[i] = NULL;
 702                 }
 703         }
 704
 705         exit_status = compat20 ? ssh_session2() : ssh_session();
 706         packet_close();
 707
 708         if (options.control_path != NULL && control_fd != -1)
 709                 unlink(options.control_path);
 710
 711         /*
 712          * Send SIGHUP to proxy command if used. We don't wait() in
 713          * case it hangs and instead rely on init to reap the child
 714          */
 715         if (proxy_command_pid > 1)
 716                 kill(proxy_command_pid, SIGHUP);
 717
 718         return exit_status;
 719 }
 720
 721 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 722
 723 static void
 724 x11_get_proto(char **_proto, char **_data)
 725 {
 726         char cmd[1024];
 727         char line[512];
 728         char xdisplay[512];
 729         static char proto[512], data[512];
 730         FILE *f;
 731         int got_data = 0, generated = 0, do_unlink = 0, i;
 732         char *display, *xauthdir, *xauthfile;
 733         struct stat st;
 734
 735         xauthdir = xauthfile = NULL;
 736         *_proto = proto;
 737         *_data = data;
 738         proto[0] = data[0] = '\0';
 739
 740         if (!options.xauth_location ||
 741             (stat(options.xauth_location, &st) == -1)) {
 742                 debug("No xauth program.");
 743         } else {
 744                 if ((display = getenv("DISPLAY")) == NULL) {
 745                         debug("x11_get_proto: DISPLAY not set");
 746                         return;
 747                 }
 748                 /*
 749                  * Handle FamilyLocal case where $DISPLAY does
 750                  * not match an authorization entry.  For this we
 751                  * just try "xauth list unix:displaynum.screennum".
 752                  * XXX: "localhost" match to determine FamilyLocal
 753                  *      is not perfect.
 754                  */
 755                 if (strncmp(display, "localhost:", 10) == 0) {
 756                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 757                             display + 10);
 758                         display = xdisplay;
 759                 }
 760                 if (options.forward_x11_trusted == 0) {
 761                         xauthdir = xmalloc(MAXPATHLEN);
 762                         xauthfile = xmalloc(MAXPATHLEN);
 763                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 764                         if (mkdtemp(xauthdir) != NULL) {
 765                                 do_unlink = 1;
 766                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 767                                     xauthdir);
 768                                 snprintf(cmd, sizeof(cmd),
 769                                     "%s -f %s generate %s " SSH_X11_PROTO
 770                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 771                                     options.xauth_location, xauthfile, display);
 772                                 debug2("x11_get_proto: %s", cmd);
 773                                 if (system(cmd) == 0)
 774                                         generated = 1;
 775                         }
 776                 }
 777                 snprintf(cmd, sizeof(cmd),
 778                     "%s %s%s list %s . 2>" _PATH_DEVNULL,
 779                     options.xauth_location,
 780                     generated ? "-f " : "" ,
 781                     generated ? xauthfile : "",
 782                     display);
 783                 debug2("x11_get_proto: %s", cmd);
 784                 f = popen(cmd, "r");
 785                 if (f && fgets(line, sizeof(line), f) &&
 786                     sscanf(line, "%*s %511s %511s", proto, data) == 2)
 787                         got_data = 1;
 788                 if (f)
 789                         pclose(f);
 790         }
 791
 792         if (do_unlink) {
 793                 unlink(xauthfile);
 794                 rmdir(xauthdir);
 795         }
 796         if (xauthdir)
 797                 xfree(xauthdir);
 798         if (xauthfile)
 799                 xfree(xauthfile);
 800
 801         /*
 802          * If we didn't get authentication data, just make up some
 803          * data.  The forwarding code will check the validity of the
 804          * response anyway, and substitute this data.  The X11
 805          * server, however, will ignore this fake data and use
 806          * whatever authentication mechanisms it was using otherwise
 807          * for the local connection.
 808          */
 809         if (!got_data) {
 810                 u_int32_t rnd = 0;
 811
 812                 logit("Warning: No xauth data; "
 813                     "using fake authentication data for X11 forwarding.");
 814                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 815                 for (i = 0; i < 16; i++) {
 816                         if (i % 4 == 0)
 817                                 rnd = arc4random();
 818                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 819                             rnd & 0xff);
 820                         rnd >>= 8;
 821                 }
 822         }
 823 }
 824
 825 static void
 826 ssh_init_forwarding(void)
 827 {
 828         int success = 0;
 829         int i;
 830
 831         /* Initiate local TCP/IP port forwardings. */
 832         for (i = 0; i < options.num_local_forwards; i++) {
 833                 debug("Connections to local port %d forwarded to remote address %.200s:%d",
 834                     options.local_forwards[i].port,
 835                     options.local_forwards[i].host,
 836                     options.local_forwards[i].host_port);
 837                 success += channel_setup_local_fwd_listener(
 838                     options.local_forwards[i].port,
 839                     options.local_forwards[i].host,
 840                     options.local_forwards[i].host_port,
 841                     options.gateway_ports);
 842         }
 843         if (i > 0 && success == 0)
 844                 error("Could not request local forwarding.");
 845
 846         /* Initiate remote TCP/IP port forwardings. */
 847         for (i = 0; i < options.num_remote_forwards; i++) {
 848                 debug("Connections to remote port %d forwarded to local address %.200s:%d",
 849                     options.remote_forwards[i].port,
 850                     options.remote_forwards[i].host,
 851                     options.remote_forwards[i].host_port);
 852                 channel_request_remote_forwarding(
 853                     options.remote_forwards[i].port,
 854                     options.remote_forwards[i].host,
 855                     options.remote_forwards[i].host_port);
 856         }
 857 }
 858
 859 static void
 860 check_agent_present(void)
 861 {
 862         if (options.forward_agent) {
 863                 /* Clear agent forwarding if we don\'t have an agent. */
 864                 if (!ssh_agent_present())
 865                         options.forward_agent = 0;
 866         }
 867 }
 868
 869 static int
 870 ssh_session(void)
 871 {
 872         int type;
 873         int interactive = 0;
 874         int have_tty = 0;
 875         struct winsize ws;
 876         char *cp;
 877
 878         /* Enable compression if requested. */
 879         if (options.compression) {
 880                 debug("Requesting compression at level %d.", options.compression_level);
 881
 882                 if (options.compression_level < 1 || options.compression_level > 9)
 883                         fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
 884
 885                 /* Send the request. */
 886                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
 887                 packet_put_int(options.compression_level);
 888                 packet_send();
 889                 packet_write_wait();
 890                 type = packet_read();
 891                 if (type == SSH_SMSG_SUCCESS)
 892                         packet_start_compression(options.compression_level);
 893                 else if (type == SSH_SMSG_FAILURE)
 894                         logit("Warning: Remote host refused compression.");
 895                 else
 896                         packet_disconnect("Protocol error waiting for compression response.");
 897         }
 898         /* Allocate a pseudo tty if appropriate. */
 899         if (tty_flag) {
 900                 debug("Requesting pty.");
 901
 902                 /* Start the packet. */
 903                 packet_start(SSH_CMSG_REQUEST_PTY);
 904
 905                 /* Store TERM in the packet.  There is no limit on the
 906                    length of the string. */
 907                 cp = getenv("TERM");
 908                 if (!cp)
 909                         cp = "";
 910                 packet_put_cstring(cp);
 911
 912                 /* Store window size in the packet. */
 913                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 914                         memset(&ws, 0, sizeof(ws));
 915                 packet_put_int(ws.ws_row);
 916                 packet_put_int(ws.ws_col);
 917                 packet_put_int(ws.ws_xpixel);
 918                 packet_put_int(ws.ws_ypixel);
 919
 920                 /* Store tty modes in the packet. */
 921                 tty_make_modes(fileno(stdin), NULL);
 922
 923                 /* Send the packet, and wait for it to leave. */
 924                 packet_send();
 925                 packet_write_wait();
 926
 927                 /* Read response from the server. */
 928                 type = packet_read();
 929                 if (type == SSH_SMSG_SUCCESS) {
 930                         interactive = 1;
 931                         have_tty = 1;
 932                 } else if (type == SSH_SMSG_FAILURE)
 933                         logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
 934                 else
 935                         packet_disconnect("Protocol error waiting for pty request response.");
 936         }
 937         /* Request X11 forwarding if enabled and DISPLAY is set. */
 938         if (options.forward_x11 && getenv("DISPLAY") != NULL) {
 939                 char *proto, *data;
 940                 /* Get reasonable local authentication information. */
 941                 x11_get_proto(&proto, &data);
 942                 /* Request forwarding with authentication spoofing. */
 943                 debug("Requesting X11 forwarding with authentication spoofing.");
 944                 x11_request_forwarding_with_spoofing(0, proto, data);
 945
 946                 /* Read response from the server. */
 947                 type = packet_read();
 948                 if (type == SSH_SMSG_SUCCESS) {
 949                         interactive = 1;
 950                 } else if (type == SSH_SMSG_FAILURE) {
 951                         logit("Warning: Remote host denied X11 forwarding.");
 952                 } else {
 953                         packet_disconnect("Protocol error waiting for X11 forwarding");
 954                 }
 955         }
 956         /* Tell the packet module whether this is an interactive session. */
 957         packet_set_interactive(interactive);
 958
 959         /* Request authentication agent forwarding if appropriate. */
 960         check_agent_present();
 961
 962         if (options.forward_agent) {
 963                 debug("Requesting authentication agent forwarding.");
 964                 auth_request_forwarding();
 965
 966                 /* Read response from the server. */
 967                 type = packet_read();
 968                 packet_check_eom();
 969                 if (type != SSH_SMSG_SUCCESS)
 970                         logit("Warning: Remote host denied authentication agent forwarding.");
 971         }
 972
 973         /* Initiate port forwardings. */
 974         ssh_init_forwarding();
 975
 976         /* If requested, let ssh continue in the background. */
 977         if (fork_after_authentication_flag)
 978                 if (daemon(1, 1) < 0)
 979                         fatal("daemon() failed: %.200s", strerror(errno));
 980
 981         /*
 982          * If a command was specified on the command line, execute the
 983          * command now. Otherwise request the server to start a shell.
 984          */
 985         if (buffer_len(&command) > 0) {
 986                 int len = buffer_len(&command);
 987                 if (len > 900)
 988                         len = 900;
 989                 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
 990                 packet_start(SSH_CMSG_EXEC_CMD);
 991                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
 992                 packet_send();
 993                 packet_write_wait();
 994         } else {
 995                 debug("Requesting shell.");
 996                 packet_start(SSH_CMSG_EXEC_SHELL);
 997                 packet_send();
 998                 packet_write_wait();
 999         }
1000
1001         /* Enter the interactive session. */
1002         return client_loop(have_tty, tty_flag ?
1003             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1004 }
1005
1006 static void
1007 ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
1008 {
1009         int id, len;
1010
1011         id = packet_get_int();
1012         len = buffer_len(&command);
1013         if (len > 900)
1014                 len = 900;
1015         packet_check_eom();
1016         if (type == SSH2_MSG_CHANNEL_FAILURE)
1017                 fatal("Request for subsystem '%.*s' failed on channel %d",
1018                     len, (u_char *)buffer_ptr(&command), id);
1019 }
1020
1021 void
1022 client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
1023 {
1024         int i;
1025
1026         i = client_global_request_id++;
1027         if (i >= options.num_remote_forwards)
1028                 return;
1029         debug("remote forward %s for: listen %d, connect %s:%d",
1030             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1031             options.remote_forwards[i].port,
1032             options.remote_forwards[i].host,
1033             options.remote_forwards[i].host_port);
1034         if (type == SSH2_MSG_REQUEST_FAILURE)
1035                 logit("Warning: remote port forwarding failed for listen port %d",
1036                     options.remote_forwards[i].port);
1037 }
1038
1039 static void
1040 ssh_control_listener(void)
1041 {
1042         struct sockaddr_un addr;
1043         mode_t old_umask;
1044         int addr_len;
1045
1046         if (options.control_path == NULL || options.control_master <= 0)
1047                 return;
1048
1049         memset(&addr, '\0', sizeof(addr));
1050         addr.sun_family = AF_UNIX;
1051         addr_len = offsetof(struct sockaddr_un, sun_path) +
1052             strlen(options.control_path) + 1;
1053
1054         if (strlcpy(addr.sun_path, options.control_path,
1055             sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1056                 fatal("ControlPath too long");
1057
1058         if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1059                 fatal("%s socket(): %s\n", __func__, strerror(errno));
1060
1061         old_umask = umask(0177);
1062         if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) {
1063                 control_fd = -1;
1064                 if (errno == EINVAL)
1065                         fatal("ControlSocket %s already exists",
1066                             options.control_path);
1067                 else
1068                         fatal("%s bind(): %s\n", __func__, strerror(errno));
1069         }
1070         umask(old_umask);
1071
1072         if (listen(control_fd, 64) == -1)
1073                 fatal("%s listen(): %s\n", __func__, strerror(errno));
1074
1075         set_nonblock(control_fd);
1076 }
1077
1078 /* request pty/x11/agent/tcpfwd/shell for channel */
1079 static void
1080 ssh_session2_setup(int id, void *arg)
1081 {
1082         extern char **environ;
1083
1084         int interactive = tty_flag;
1085         if (options.forward_x11 && getenv("DISPLAY") != NULL) {
1086                 char *proto, *data;
1087                 /* Get reasonable local authentication information. */
1088                 x11_get_proto(&proto, &data);
1089                 /* Request forwarding with authentication spoofing. */
1090                 debug("Requesting X11 forwarding with authentication spoofing.");
1091                 x11_request_forwarding_with_spoofing(id, proto, data);
1092                 interactive = 1;
1093                 /* XXX wait for reply */
1094         }
1095
1096         check_agent_present();
1097         if (options.forward_agent) {
1098                 debug("Requesting authentication agent forwarding.");
1099                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1100                 packet_send();
1101         }
1102
1103         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1104             NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
1105
1106         packet_set_interactive(interactive);
1107 }
1108
1109 /* open new channel for a session */
1110 static int
1111 ssh_session2_open(void)
1112 {
1113         Channel *c;
1114         int window, packetmax, in, out, err;
1115
1116         if (stdin_null_flag) {
1117                 in = open(_PATH_DEVNULL, O_RDONLY);
1118         } else {
1119                 in = dup(STDIN_FILENO);
1120         }
1121         out = dup(STDOUT_FILENO);
1122         err = dup(STDERR_FILENO);
1123
1124         if (in < 0 || out < 0 || err < 0)
1125                 fatal("dup() in/out/err failed");
1126
1127         /* enable nonblocking unless tty */
1128         if (!isatty(in))
1129                 set_nonblock(in);
1130         if (!isatty(out))
1131                 set_nonblock(out);
1132         if (!isatty(err))
1133                 set_nonblock(err);
1134
1135         window = CHAN_SES_WINDOW_DEFAULT;
1136         packetmax = CHAN_SES_PACKET_DEFAULT;
1137         if (tty_flag) {
1138                 window >>= 1;
1139                 packetmax >>= 1;
1140         }
1141         c = channel_new(
1142             "session", SSH_CHANNEL_OPENING, in, out, err,
1143             window, packetmax, CHAN_EXTENDED_WRITE,
1144             "client-session", /*nonblock*/0);
1145
1146         debug3("ssh_session2_open: channel_new: %d", c->self);
1147
1148         channel_send_open(c->self);
1149         if (!no_shell_flag)
1150                 channel_register_confirm(c->self, ssh_session2_setup, NULL);
1151
1152         return c->self;
1153 }
1154
1155 static int
1156 ssh_session2(void)
1157 {
1158         int id = -1;
1159
1160         /* XXX should be pre-session */
1161         ssh_init_forwarding();
1162         ssh_control_listener();
1163
1164         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1165                 id = ssh_session2_open();
1166
1167         /* If requested, let ssh continue in the background. */
1168         if (fork_after_authentication_flag)
1169                 if (daemon(1, 1) < 0)
1170                         fatal("daemon() failed: %.200s", strerror(errno));
1171
1172         return client_loop(tty_flag, tty_flag ?
1173             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1174 }
1175
1176 static void
1177 load_public_identity_files(void)
1178 {
1179         char *filename;
1180         int i = 0;
1181         Key *public;
1182 #ifdef SMARTCARD
1183         Key **keys;
1184
1185         if (options.smartcard_device != NULL &&
1186             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1187             (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
1188                 int count = 0;
1189                 for (i = 0; keys[i] != NULL; i++) {
1190                         count++;
1191                         memmove(&options.identity_files[1], &options.identity_files[0],
1192                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1193                         memmove(&options.identity_keys[1], &options.identity_keys[0],
1194                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1195                         options.num_identity_files++;
1196                         options.identity_keys[0] = keys[i];
1197                         options.identity_files[0] = sc_get_key_label(keys[i]);
1198                 }
1199                 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1200                         options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1201                 i = count;
1202                 xfree(keys);
1203         }
1204 #endif /* SMARTCARD */
1205         for (; i < options.num_identity_files; i++) {
1206                 filename = tilde_expand_filename(options.identity_files[i],
1207                     original_real_uid);
1208                 public = key_load_public(filename, NULL);
1209                 debug("identity file %s type %d", filename,
1210                     public ? public->type : -1);
1211                 xfree(options.identity_files[i]);
1212                 options.identity_files[i] = filename;
1213                 options.identity_keys[i] = public;
1214         }
1215 }
1216
1217 static void
1218 control_client_sighandler(int signo)
1219 {
1220         control_client_terminate = signo;
1221 }
1222
1223 static void
1224 control_client_sigrelay(int signo)
1225 {
1226         if (control_server_pid > 1)
1227                 kill(control_server_pid, signo);
1228 }
1229
1230 static int
1231 env_permitted(char *env)
1232 {
1233         int i;
1234         char name[1024], *cp;
1235
1236         strlcpy(name, env, sizeof(name));
1237         if ((cp = strchr(name, '=')) == NULL)
1238                 return (0);
1239
1240         *cp = '\0';
1241
1242         for (i = 0; i < options.num_send_env; i++)
1243                 if (match_pattern(name, options.send_env[i]))
1244                         return (1);
1245
1246         return (0);
1247 }
1248
1249 static void
1250 control_client(const char *path)
1251 {
1252         struct sockaddr_un addr;
1253         int i, r, sock, exitval, num_env, addr_len;
1254         Buffer m;
1255         char *cp;
1256         extern char **environ;
1257
1258         memset(&addr, '\0', sizeof(addr));
1259         addr.sun_family = AF_UNIX;
1260         addr_len = offsetof(struct sockaddr_un, sun_path) +
1261             strlen(path) + 1;
1262
1263         if (strlcpy(addr.sun_path, path,
1264             sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1265                 fatal("ControlPath too long");
1266
1267         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1268                 fatal("%s socket(): %s", __func__, strerror(errno));
1269
1270         if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1)
1271                 fatal("Couldn't connect to %s: %s", path, strerror(errno));
1272
1273         if ((cp = getenv("TERM")) == NULL)
1274                 cp = "";
1275
1276         buffer_init(&m);
1277
1278         /* Get PID of controlee */
1279         if (ssh_msg_recv(sock, &m) == -1)
1280                 fatal("%s: msg_recv", __func__);
1281         if (buffer_get_char(&m) != 0)
1282                 fatal("%s: wrong version", __func__);
1283         /* Connection allowed? */
1284         if (buffer_get_int(&m) != 1)
1285                 fatal("Connection to master denied");
1286         control_server_pid = buffer_get_int(&m);
1287
1288         buffer_clear(&m);
1289         buffer_put_int(&m, tty_flag);
1290         buffer_put_int(&m, subsystem_flag);
1291         buffer_put_cstring(&m, cp);
1292
1293         buffer_append(&command, "\0", 1);
1294         buffer_put_cstring(&m, buffer_ptr(&command));
1295
1296         if (options.num_send_env == 0 || environ == NULL) {
1297                 buffer_put_int(&m, 0);
1298         } else {
1299                 /* Pass environment */
1300                 num_env = 0;
1301                 for (i = 0; environ[i] != NULL; i++)
1302                         if (env_permitted(environ[i]))
1303                                 num_env++; /* Count */
1304
1305                 buffer_put_int(&m, num_env);
1306
1307                 for (i = 0; environ[i] != NULL && num_env >= 0; i++)
1308                         if (env_permitted(environ[i])) {
1309                                 num_env--;
1310                                 buffer_put_cstring(&m, environ[i]);
1311                         }
1312         }
1313
1314         if (ssh_msg_send(sock, /* version */0, &m) == -1)
1315                 fatal("%s: msg_send", __func__);
1316
1317         mm_send_fd(sock, STDIN_FILENO);
1318         mm_send_fd(sock, STDOUT_FILENO);
1319         mm_send_fd(sock, STDERR_FILENO);
1320
1321         /* Wait for reply, so master has a chance to gather ttymodes */
1322         buffer_clear(&m);
1323         if (ssh_msg_recv(sock, &m) == -1)
1324                 fatal("%s: msg_recv", __func__);
1325         if (buffer_get_char(&m) != 0)
1326                 fatal("%s: master returned error", __func__);
1327         buffer_free(&m);
1328
1329         signal(SIGINT, control_client_sighandler);
1330         signal(SIGTERM, control_client_sighandler);
1331         signal(SIGWINCH, control_client_sigrelay);
1332
1333         if (tty_flag)
1334                 enter_raw_mode();
1335
1336         /* Stick around until the controlee closes the client_fd */
1337         exitval = 0;
1338         for (;!control_client_terminate;) {
1339                 r = read(sock, &exitval, sizeof(exitval));
1340                 if (r == 0) {
1341                         debug2("Received EOF from master");
1342                         break;
1343                 }
1344                 if (r > 0)
1345                         debug2("Received exit status from master %d", exitval);
1346                 if (r == -1 && errno != EINTR)
1347                         fatal("%s: read %s", __func__, strerror(errno));
1348         }
1349
1350         if (control_client_terminate)
1351                 debug2("Exiting on signal %d", control_client_terminate);
1352
1353         close(sock);
1354
1355         leave_raw_mode();
1356
1357         if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1358                 fprintf(stderr, "Connection to master closed.\r\n");
1359
1360         exit(exitval);
1361 }