crypto/openssh/serverloop.c

   1 /* $OpenBSD: serverloop.c,v 1.164 2012/12/07 01:51:35 dtucker Exp $ */
   2 /* $FreeBSD$ */
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * Server main loop for handling the interactive session.
   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  * SSH2 support by Markus Friedl.
  16  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions
  20  * are met:
  21  * 1. Redistributions of source code must retain the above copyright
  22  *    notice, this list of conditions and the following disclaimer.
  23  * 2. Redistributions in binary form must reproduce the above copyright
  24  *    notice, this list of conditions and the following disclaimer in the
  25  *    documentation and/or other materials provided with the distribution.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  28  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  29  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  30  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  31  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  32  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  33  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  34  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  36  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 #include "includes.h"
  40
  41 #include <sys/types.h>
  42 #include <sys/param.h>
  43 #include <sys/wait.h>
  44 #include <sys/socket.h>
  45 #ifdef HAVE_SYS_TIME_H
  46 # include <sys/time.h>
  47 #endif
  48
  49 #include <netinet/in.h>
  50
  51 #include <errno.h>
  52 #include <fcntl.h>
  53 #include <pwd.h>
  54 #include <signal.h>
  55 #include <string.h>
  56 #include <termios.h>
  57 #include <unistd.h>
  58 #include <stdarg.h>
  59
  60 #include "openbsd-compat/sys-queue.h"
  61 #include "xmalloc.h"
  62 #include "packet.h"
  63 #include "buffer.h"
  64 #include "log.h"
  65 #include "servconf.h"
  66 #include "canohost.h"
  67 #include "sshpty.h"
  68 #include "channels.h"
  69 #include "compat.h"
  70 #include "ssh1.h"
  71 #include "ssh2.h"
  72 #include "key.h"
  73 #include "cipher.h"
  74 #include "kex.h"
  75 #include "hostfile.h"
  76 #include "auth.h"
  77 #include "session.h"
  78 #include "dispatch.h"
  79 #include "auth-options.h"
  80 #include "serverloop.h"
  81 #include "misc.h"
  82 #include "roaming.h"
  83
  84 extern ServerOptions options;
  85
  86 /* XXX */
  87 extern Kex *xxx_kex;
  88 extern Authctxt *the_authctxt;
  89 extern int use_privsep;
  90
  91 static Buffer stdin_buffer;     /* Buffer for stdin data. */
  92 static Buffer stdout_buffer;    /* Buffer for stdout data. */
  93 static Buffer stderr_buffer;    /* Buffer for stderr data. */
  94 static int fdin;                /* Descriptor for stdin (for writing) */
  95 static int fdout;               /* Descriptor for stdout (for reading);
  96                                    May be same number as fdin. */
  97 static int fderr;               /* Descriptor for stderr.  May be -1. */
  98 static long stdin_bytes = 0;    /* Number of bytes written to stdin. */
  99 static long stdout_bytes = 0;   /* Number of stdout bytes sent to client. */
 100 static long stderr_bytes = 0;   /* Number of stderr bytes sent to client. */
 101 static long fdout_bytes = 0;    /* Number of stdout bytes read from program. */
 102 static int stdin_eof = 0;       /* EOF message received from client. */
 103 static int fdout_eof = 0;       /* EOF encountered reading from fdout. */
 104 static int fderr_eof = 0;       /* EOF encountered readung from fderr. */
 105 static int fdin_is_tty = 0;     /* fdin points to a tty. */
 106 static int connection_in;       /* Connection to client (input). */
 107 static int connection_out;      /* Connection to client (output). */
 108 static int connection_closed = 0;       /* Connection to client closed. */
 109 static u_int buffer_high;       /* "Soft" max buffer size. */
 110 static int no_more_sessions = 0; /* Disallow further sessions. */
 111
 112 /*
 113  * This SIGCHLD kludge is used to detect when the child exits.  The server
 114  * will exit after that, as soon as forwarded connections have terminated.
 115  */
 116
 117 static volatile sig_atomic_t child_terminated = 0;      /* The child has terminated. */
 118
 119 /* Cleanup on signals (!use_privsep case only) */
 120 static volatile sig_atomic_t received_sigterm = 0;
 121
 122 /* prototypes */
 123 static void server_init_dispatch(void);
 124
 125 /*
 126  * we write to this pipe if a SIGCHLD is caught in order to avoid
 127  * the race between select() and child_terminated
 128  */
 129 static int notify_pipe[2];
 130 static void
 131 notify_setup(void)
 132 {
 133         if (pipe(notify_pipe) < 0) {
 134                 error("pipe(notify_pipe) failed %s", strerror(errno));
 135         } else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
 136             (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) {
 137                 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
 138                 close(notify_pipe[0]);
 139                 close(notify_pipe[1]);
 140         } else {
 141                 set_nonblock(notify_pipe[0]);
 142                 set_nonblock(notify_pipe[1]);
 143                 return;
 144         }
 145         notify_pipe[0] = -1;    /* read end */
 146         notify_pipe[1] = -1;    /* write end */
 147 }
 148 static void
 149 notify_parent(void)
 150 {
 151         if (notify_pipe[1] != -1)
 152                 write(notify_pipe[1], "", 1);
 153 }
 154 static void
 155 notify_prepare(fd_set *readset)
 156 {
 157         if (notify_pipe[0] != -1)
 158                 FD_SET(notify_pipe[0], readset);
 159 }
 160 static void
 161 notify_done(fd_set *readset)
 162 {
 163         char c;
 164
 165         if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
 166                 while (read(notify_pipe[0], &c, 1) != -1)
 167                         debug2("notify_done: reading");
 168 }
 169
 170 /*ARGSUSED*/
 171 static void
 172 sigchld_handler(int sig)
 173 {
 174         int save_errno = errno;
 175         child_terminated = 1;
 176 #ifndef _UNICOS
 177         mysignal(SIGCHLD, sigchld_handler);
 178 #endif
 179         notify_parent();
 180         errno = save_errno;
 181 }
 182
 183 /*ARGSUSED*/
 184 static void
 185 sigterm_handler(int sig)
 186 {
 187         received_sigterm = sig;
 188 }
 189
 190 /*
 191  * Make packets from buffered stderr data, and buffer it for sending
 192  * to the client.
 193  */
 194 static void
 195 make_packets_from_stderr_data(void)
 196 {
 197         u_int len;
 198
 199         /* Send buffered stderr data to the client. */
 200         while (buffer_len(&stderr_buffer) > 0 &&
 201             packet_not_very_much_data_to_write()) {
 202                 len = buffer_len(&stderr_buffer);
 203                 if (packet_is_interactive()) {
 204                         if (len > 512)
 205                                 len = 512;
 206                 } else {
 207                         /* Keep the packets at reasonable size. */
 208                         if (len > packet_get_maxsize())
 209                                 len = packet_get_maxsize();
 210                 }
 211                 packet_start(SSH_SMSG_STDERR_DATA);
 212                 packet_put_string(buffer_ptr(&stderr_buffer), len);
 213                 packet_send();
 214                 buffer_consume(&stderr_buffer, len);
 215                 stderr_bytes += len;
 216         }
 217 }
 218
 219 /*
 220  * Make packets from buffered stdout data, and buffer it for sending to the
 221  * client.
 222  */
 223 static void
 224 make_packets_from_stdout_data(void)
 225 {
 226         u_int len;
 227
 228         /* Send buffered stdout data to the client. */
 229         while (buffer_len(&stdout_buffer) > 0 &&
 230             packet_not_very_much_data_to_write()) {
 231                 len = buffer_len(&stdout_buffer);
 232                 if (packet_is_interactive()) {
 233                         if (len > 512)
 234                                 len = 512;
 235                 } else {
 236                         /* Keep the packets at reasonable size. */
 237                         if (len > packet_get_maxsize())
 238                                 len = packet_get_maxsize();
 239                 }
 240                 packet_start(SSH_SMSG_STDOUT_DATA);
 241                 packet_put_string(buffer_ptr(&stdout_buffer), len);
 242                 packet_send();
 243                 buffer_consume(&stdout_buffer, len);
 244                 stdout_bytes += len;
 245         }
 246 }
 247
 248 static void
 249 client_alive_check(void)
 250 {
 251         int channel_id;
 252
 253         /* timeout, check to see how many we have had */
 254         if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
 255                 logit("Timeout, client not responding.");
 256                 cleanup_exit(255);
 257         }
 258
 259         /*
 260          * send a bogus global/channel request with "wantreply",
 261          * we should get back a failure
 262          */
 263         if ((channel_id = channel_find_open()) == -1) {
 264                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
 265                 packet_put_cstring("keepalive@openssh.com");
 266                 packet_put_char(1);     /* boolean: want reply */
 267         } else {
 268                 channel_request_start(channel_id, "keepalive@openssh.com", 1);
 269         }
 270         packet_send();
 271 }
 272
 273 /*
 274  * Sleep in select() until we can do something.  This will initialize the
 275  * select masks.  Upon return, the masks will indicate which descriptors
 276  * have data or can accept data.  Optionally, a maximum time can be specified
 277  * for the duration of the wait (0 = infinite).
 278  */
 279 static void
 280 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
 281     u_int *nallocp, u_int max_time_milliseconds)
 282 {
 283         struct timeval tv, *tvp;
 284         int ret;
 285         time_t minwait_secs = 0;
 286         int client_alive_scheduled = 0;
 287         int program_alive_scheduled = 0;
 288
 289         /* Allocate and update select() masks for channel descriptors. */
 290         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
 291             &minwait_secs, 0);
 292
 293         if (minwait_secs != 0)
 294                 max_time_milliseconds = MIN(max_time_milliseconds,
 295                     (u_int)minwait_secs * 1000);
 296
 297         /*
 298          * if using client_alive, set the max timeout accordingly,
 299          * and indicate that this particular timeout was for client
 300          * alive by setting the client_alive_scheduled flag.
 301          *
 302          * this could be randomized somewhat to make traffic
 303          * analysis more difficult, but we're not doing it yet.
 304          */
 305         if (compat20 &&
 306             max_time_milliseconds == 0 && options.client_alive_interval) {
 307                 client_alive_scheduled = 1;
 308                 max_time_milliseconds = options.client_alive_interval * 1000;
 309         }
 310
 311         if (compat20) {
 312 #if 0
 313                 /* wrong: bad condition XXX */
 314                 if (channel_not_very_much_buffered_data())
 315 #endif
 316                 FD_SET(connection_in, *readsetp);
 317         } else {
 318                 /*
 319                  * Read packets from the client unless we have too much
 320                  * buffered stdin or channel data.
 321                  */
 322                 if (buffer_len(&stdin_buffer) < buffer_high &&
 323                     channel_not_very_much_buffered_data())
 324                         FD_SET(connection_in, *readsetp);
 325                 /*
 326                  * If there is not too much data already buffered going to
 327                  * the client, try to get some more data from the program.
 328                  */
 329                 if (packet_not_very_much_data_to_write()) {
 330                         program_alive_scheduled = child_terminated;
 331                         if (!fdout_eof)
 332                                 FD_SET(fdout, *readsetp);
 333                         if (!fderr_eof)
 334                                 FD_SET(fderr, *readsetp);
 335                 }
 336                 /*
 337                  * If we have buffered data, try to write some of that data
 338                  * to the program.
 339                  */
 340                 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
 341                         FD_SET(fdin, *writesetp);
 342         }
 343         notify_prepare(*readsetp);
 344
 345         /*
 346          * If we have buffered packet data going to the client, mark that
 347          * descriptor.
 348          */
 349         if (packet_have_data_to_write())
 350                 FD_SET(connection_out, *writesetp);
 351
 352         /*
 353          * If child has terminated and there is enough buffer space to read
 354          * from it, then read as much as is available and exit.
 355          */
 356         if (child_terminated && packet_not_very_much_data_to_write())
 357                 if (max_time_milliseconds == 0 || client_alive_scheduled)
 358                         max_time_milliseconds = 100;
 359
 360         if (max_time_milliseconds == 0)
 361                 tvp = NULL;
 362         else {
 363                 tv.tv_sec = max_time_milliseconds / 1000;
 364                 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
 365                 tvp = &tv;
 366         }
 367
 368         /* Wait for something to happen, or the timeout to expire. */
 369         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 370
 371         if (ret == -1) {
 372                 memset(*readsetp, 0, *nallocp);
 373                 memset(*writesetp, 0, *nallocp);
 374                 if (errno != EINTR)
 375                         error("select: %.100s", strerror(errno));
 376         } else {
 377                 if (ret == 0 && client_alive_scheduled)
 378                         client_alive_check();
 379                 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
 380                         if (!fdout_eof)
 381                                 FD_SET(fdout, *readsetp);
 382                         if (!fderr_eof)
 383                                 FD_SET(fderr, *readsetp);
 384                 }
 385         }
 386
 387         notify_done(*readsetp);
 388 }
 389
 390 /*
 391  * Processes input from the client and the program.  Input data is stored
 392  * in buffers and processed later.
 393  */
 394 static void
 395 process_input(fd_set *readset)
 396 {
 397         int len;
 398         char buf[16384];
 399
 400         /* Read and buffer any input data from the client. */
 401         if (FD_ISSET(connection_in, readset)) {
 402                 int cont = 0;
 403                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 404                 if (len == 0) {
 405                         if (cont)
 406                                 return;
 407                         verbose("Connection closed by %.100s",
 408                             get_remote_ipaddr());
 409                         connection_closed = 1;
 410                         if (compat20)
 411                                 return;
 412                         cleanup_exit(255);
 413                 } else if (len < 0) {
 414                         if (errno != EINTR && errno != EAGAIN &&
 415                             errno != EWOULDBLOCK) {
 416                                 verbose("Read error from remote host "
 417                                     "%.100s: %.100s",
 418                                     get_remote_ipaddr(), strerror(errno));
 419                                 cleanup_exit(255);
 420                         }
 421                 } else {
 422                         /* Buffer any received data. */
 423                         packet_process_incoming(buf, len);
 424                 }
 425         }
 426         if (compat20)
 427                 return;
 428
 429         /* Read and buffer any available stdout data from the program. */
 430         if (!fdout_eof && FD_ISSET(fdout, readset)) {
 431                 errno = 0;
 432                 len = read(fdout, buf, sizeof(buf));
 433                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 434                     errno == EWOULDBLOCK) && !child_terminated))) {
 435                         /* do nothing */
 436 #ifndef PTY_ZEROREAD
 437                 } else if (len <= 0) {
 438 #else
 439                 } else if ((!isatty(fdout) && len <= 0) ||
 440                     (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
 441 #endif
 442                         fdout_eof = 1;
 443                 } else {
 444                         buffer_append(&stdout_buffer, buf, len);
 445                         fdout_bytes += len;
 446                 }
 447         }
 448         /* Read and buffer any available stderr data from the program. */
 449         if (!fderr_eof && FD_ISSET(fderr, readset)) {
 450                 errno = 0;
 451                 len = read(fderr, buf, sizeof(buf));
 452                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 453                     errno == EWOULDBLOCK) && !child_terminated))) {
 454                         /* do nothing */
 455 #ifndef PTY_ZEROREAD
 456                 } else if (len <= 0) {
 457 #else
 458                 } else if ((!isatty(fderr) && len <= 0) ||
 459                     (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
 460 #endif
 461                         fderr_eof = 1;
 462                 } else {
 463                         buffer_append(&stderr_buffer, buf, len);
 464                 }
 465         }
 466 }
 467
 468 /*
 469  * Sends data from internal buffers to client program stdin.
 470  */
 471 static void
 472 process_output(fd_set *writeset)
 473 {
 474         struct termios tio;
 475         u_char *data;
 476         u_int dlen;
 477         int len;
 478
 479         /* Write buffered data to program stdin. */
 480         if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
 481                 data = buffer_ptr(&stdin_buffer);
 482                 dlen = buffer_len(&stdin_buffer);
 483                 len = write(fdin, data, dlen);
 484                 if (len < 0 &&
 485                     (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
 486                         /* do nothing */
 487                 } else if (len <= 0) {
 488                         if (fdin != fdout)
 489                                 close(fdin);
 490                         else
 491                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 492                         fdin = -1;
 493                 } else {
 494                         /* Successful write. */
 495                         if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
 496                             tcgetattr(fdin, &tio) == 0 &&
 497                             !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
 498                                 /*
 499                                  * Simulate echo to reduce the impact of
 500                                  * traffic analysis
 501                                  */
 502                                 packet_send_ignore(len);
 503                                 packet_send();
 504                         }
 505                         /* Consume the data from the buffer. */
 506                         buffer_consume(&stdin_buffer, len);
 507                         /* Update the count of bytes written to the program. */
 508                         stdin_bytes += len;
 509                 }
 510         }
 511         /* Send any buffered packet data to the client. */
 512         if (FD_ISSET(connection_out, writeset))
 513                 packet_write_poll();
 514 }
 515
 516 /*
 517  * Wait until all buffered output has been sent to the client.
 518  * This is used when the program terminates.
 519  */
 520 static void
 521 drain_output(void)
 522 {
 523         /* Send any buffered stdout data to the client. */
 524         if (buffer_len(&stdout_buffer) > 0) {
 525                 packet_start(SSH_SMSG_STDOUT_DATA);
 526                 packet_put_string(buffer_ptr(&stdout_buffer),
 527                                   buffer_len(&stdout_buffer));
 528                 packet_send();
 529                 /* Update the count of sent bytes. */
 530                 stdout_bytes += buffer_len(&stdout_buffer);
 531         }
 532         /* Send any buffered stderr data to the client. */
 533         if (buffer_len(&stderr_buffer) > 0) {
 534                 packet_start(SSH_SMSG_STDERR_DATA);
 535                 packet_put_string(buffer_ptr(&stderr_buffer),
 536                                   buffer_len(&stderr_buffer));
 537                 packet_send();
 538                 /* Update the count of sent bytes. */
 539                 stderr_bytes += buffer_len(&stderr_buffer);
 540         }
 541         /* Wait until all buffered data has been written to the client. */
 542         packet_write_wait();
 543 }
 544
 545 static void
 546 process_buffered_input_packets(void)
 547 {
 548         dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
 549 }
 550
 551 /*
 552  * Performs the interactive session.  This handles data transmission between
 553  * the client and the program.  Note that the notion of stdin, stdout, and
 554  * stderr in this function is sort of reversed: this function writes to
 555  * stdin (of the child program), and reads from stdout and stderr (of the
 556  * child program).
 557  */
 558 void
 559 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 560 {
 561         fd_set *readset = NULL, *writeset = NULL;
 562         int max_fd = 0;
 563         u_int nalloc = 0;
 564         int wait_status;        /* Status returned by wait(). */
 565         pid_t wait_pid;         /* pid returned by wait(). */
 566         int waiting_termination = 0;    /* Have displayed waiting close message. */
 567         u_int max_time_milliseconds;
 568         u_int previous_stdout_buffer_bytes;
 569         u_int stdout_buffer_bytes;
 570         int type;
 571
 572         debug("Entering interactive session.");
 573
 574         /* Initialize the SIGCHLD kludge. */
 575         child_terminated = 0;
 576         mysignal(SIGCHLD, sigchld_handler);
 577
 578         if (!use_privsep) {
 579                 signal(SIGTERM, sigterm_handler);
 580                 signal(SIGINT, sigterm_handler);
 581                 signal(SIGQUIT, sigterm_handler);
 582         }
 583
 584         /* Initialize our global variables. */
 585         fdin = fdin_arg;
 586         fdout = fdout_arg;
 587         fderr = fderr_arg;
 588
 589         /* nonblocking IO */
 590         set_nonblock(fdin);
 591         set_nonblock(fdout);
 592         /* we don't have stderr for interactive terminal sessions, see below */
 593         if (fderr != -1)
 594                 set_nonblock(fderr);
 595
 596         if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
 597                 fdin_is_tty = 1;
 598
 599         connection_in = packet_get_connection_in();
 600         connection_out = packet_get_connection_out();
 601
 602         notify_setup();
 603
 604         previous_stdout_buffer_bytes = 0;
 605
 606         /* Set approximate I/O buffer size. */
 607         if (packet_is_interactive())
 608                 buffer_high = 4096;
 609         else
 610                 buffer_high = 64 * 1024;
 611
 612 #if 0
 613         /* Initialize max_fd to the maximum of the known file descriptors. */
 614         max_fd = MAX(connection_in, connection_out);
 615         max_fd = MAX(max_fd, fdin);
 616         max_fd = MAX(max_fd, fdout);
 617         if (fderr != -1)
 618                 max_fd = MAX(max_fd, fderr);
 619 #endif
 620
 621         /* Initialize Initialize buffers. */
 622         buffer_init(&stdin_buffer);
 623         buffer_init(&stdout_buffer);
 624         buffer_init(&stderr_buffer);
 625
 626         /*
 627          * If we have no separate fderr (which is the case when we have a pty
 628          * - there we cannot make difference between data sent to stdout and
 629          * stderr), indicate that we have seen an EOF from stderr.  This way
 630          * we don't need to check the descriptor everywhere.
 631          */
 632         if (fderr == -1)
 633                 fderr_eof = 1;
 634
 635         server_init_dispatch();
 636
 637         /* Main loop of the server for the interactive session mode. */
 638         for (;;) {
 639
 640                 /* Process buffered packets from the client. */
 641                 process_buffered_input_packets();
 642
 643                 /*
 644                  * If we have received eof, and there is no more pending
 645                  * input data, cause a real eof by closing fdin.
 646                  */
 647                 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
 648                         if (fdin != fdout)
 649                                 close(fdin);
 650                         else
 651                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 652                         fdin = -1;
 653                 }
 654                 /* Make packets from buffered stderr data to send to the client. */
 655                 make_packets_from_stderr_data();
 656
 657                 /*
 658                  * Make packets from buffered stdout data to send to the
 659                  * client. If there is very little to send, this arranges to
 660                  * not send them now, but to wait a short while to see if we
 661                  * are getting more data. This is necessary, as some systems
 662                  * wake up readers from a pty after each separate character.
 663                  */
 664                 max_time_milliseconds = 0;
 665                 stdout_buffer_bytes = buffer_len(&stdout_buffer);
 666                 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
 667                     stdout_buffer_bytes != previous_stdout_buffer_bytes) {
 668                         /* try again after a while */
 669                         max_time_milliseconds = 10;
 670                 } else {
 671                         /* Send it now. */
 672                         make_packets_from_stdout_data();
 673                 }
 674                 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
 675
 676                 /* Send channel data to the client. */
 677                 if (packet_not_very_much_data_to_write())
 678                         channel_output_poll();
 679
 680                 /*
 681                  * Bail out of the loop if the program has closed its output
 682                  * descriptors, and we have no more data to send to the
 683                  * client, and there is no pending buffered data.
 684                  */
 685                 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
 686                     buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
 687                         if (!channel_still_open())
 688                                 break;
 689                         if (!waiting_termination) {
 690                                 const char *s = "Waiting for forwarded connections to terminate...\r\n";
 691                                 char *cp;
 692                                 waiting_termination = 1;
 693                                 buffer_append(&stderr_buffer, s, strlen(s));
 694
 695                                 /* Display list of open channels. */
 696                                 cp = channel_open_message();
 697                                 buffer_append(&stderr_buffer, cp, strlen(cp));
 698                                 xfree(cp);
 699                         }
 700                 }
 701                 max_fd = MAX(connection_in, connection_out);
 702                 max_fd = MAX(max_fd, fdin);
 703                 max_fd = MAX(max_fd, fdout);
 704                 max_fd = MAX(max_fd, fderr);
 705                 max_fd = MAX(max_fd, notify_pipe[0]);
 706
 707                 /* Sleep in select() until we can do something. */
 708                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 709                     &nalloc, max_time_milliseconds);
 710
 711                 if (received_sigterm) {
 712                         logit("Exiting on signal %d", (int)received_sigterm);
 713                         /* Clean up sessions, utmp, etc. */
 714                         cleanup_exit(255);
 715                 }
 716
 717                 /* Process any channel events. */
 718                 channel_after_select(readset, writeset);
 719
 720                 /* Process input from the client and from program stdout/stderr. */
 721                 process_input(readset);
 722
 723                 /* Process output to the client and to program stdin. */
 724                 process_output(writeset);
 725         }
 726         if (readset)
 727                 xfree(readset);
 728         if (writeset)
 729                 xfree(writeset);
 730
 731         /* Cleanup and termination code. */
 732
 733         /* Wait until all output has been sent to the client. */
 734         drain_output();
 735
 736         debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
 737             stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
 738
 739         /* Free and clear the buffers. */
 740         buffer_free(&stdin_buffer);
 741         buffer_free(&stdout_buffer);
 742         buffer_free(&stderr_buffer);
 743
 744         /* Close the file descriptors. */
 745         if (fdout != -1)
 746                 close(fdout);
 747         fdout = -1;
 748         fdout_eof = 1;
 749         if (fderr != -1)
 750                 close(fderr);
 751         fderr = -1;
 752         fderr_eof = 1;
 753         if (fdin != -1)
 754                 close(fdin);
 755         fdin = -1;
 756
 757         channel_free_all();
 758
 759         /* We no longer want our SIGCHLD handler to be called. */
 760         mysignal(SIGCHLD, SIG_DFL);
 761
 762         while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
 763                 if (errno != EINTR)
 764                         packet_disconnect("wait: %.100s", strerror(errno));
 765         if (wait_pid != pid)
 766                 error("Strange, wait returned pid %ld, expected %ld",
 767                     (long)wait_pid, (long)pid);
 768
 769         /* Check if it exited normally. */
 770         if (WIFEXITED(wait_status)) {
 771                 /* Yes, normal exit.  Get exit status and send it to the client. */
 772                 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
 773                 packet_start(SSH_SMSG_EXITSTATUS);
 774                 packet_put_int(WEXITSTATUS(wait_status));
 775                 packet_send();
 776                 packet_write_wait();
 777
 778                 /*
 779                  * Wait for exit confirmation.  Note that there might be
 780                  * other packets coming before it; however, the program has
 781                  * already died so we just ignore them.  The client is
 782                  * supposed to respond with the confirmation when it receives
 783                  * the exit status.
 784                  */
 785                 do {
 786                         type = packet_read();
 787                 }
 788                 while (type != SSH_CMSG_EXIT_CONFIRMATION);
 789
 790                 debug("Received exit confirmation.");
 791                 return;
 792         }
 793         /* Check if the program terminated due to a signal. */
 794         if (WIFSIGNALED(wait_status))
 795                 packet_disconnect("Command terminated on signal %d.",
 796                                   WTERMSIG(wait_status));
 797
 798         /* Some weird exit cause.  Just exit. */
 799         packet_disconnect("wait returned status %04x.", wait_status);
 800         /* NOTREACHED */
 801 }
 802
 803 static void
 804 collect_children(void)
 805 {
 806         pid_t pid;
 807         sigset_t oset, nset;
 808         int status;
 809
 810         /* block SIGCHLD while we check for dead children */
 811         sigemptyset(&nset);
 812         sigaddset(&nset, SIGCHLD);
 813         sigprocmask(SIG_BLOCK, &nset, &oset);
 814         if (child_terminated) {
 815                 debug("Received SIGCHLD.");
 816                 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
 817                     (pid < 0 && errno == EINTR))
 818                         if (pid > 0)
 819                                 session_close_by_pid(pid, status);
 820                 child_terminated = 0;
 821         }
 822         sigprocmask(SIG_SETMASK, &oset, NULL);
 823 }
 824
 825 void
 826 server_loop2(Authctxt *authctxt)
 827 {
 828         fd_set *readset = NULL, *writeset = NULL;
 829         int rekeying = 0, max_fd, nalloc = 0;
 830
 831         debug("Entering interactive session for SSH2.");
 832
 833         mysignal(SIGCHLD, sigchld_handler);
 834         child_terminated = 0;
 835         connection_in = packet_get_connection_in();
 836         connection_out = packet_get_connection_out();
 837
 838         if (!use_privsep) {
 839                 signal(SIGTERM, sigterm_handler);
 840                 signal(SIGINT, sigterm_handler);
 841                 signal(SIGQUIT, sigterm_handler);
 842         }
 843
 844         notify_setup();
 845
 846         max_fd = MAX(connection_in, connection_out);
 847         max_fd = MAX(max_fd, notify_pipe[0]);
 848
 849         server_init_dispatch();
 850
 851         for (;;) {
 852                 process_buffered_input_packets();
 853
 854                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 855
 856                 if (!rekeying && packet_not_very_much_data_to_write())
 857                         channel_output_poll();
 858                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 859                     &nalloc, 0);
 860
 861                 if (received_sigterm) {
 862                         logit("Exiting on signal %d", (int)received_sigterm);
 863                         /* Clean up sessions, utmp, etc. */
 864                         cleanup_exit(255);
 865                 }
 866
 867                 collect_children();
 868                 if (!rekeying) {
 869                         channel_after_select(readset, writeset);
 870                         if (packet_need_rekeying()) {
 871                                 debug("need rekeying");
 872                                 xxx_kex->done = 0;
 873                                 kex_send_kexinit(xxx_kex);
 874                         }
 875                 }
 876                 process_input(readset);
 877                 if (connection_closed)
 878                         break;
 879                 process_output(writeset);
 880         }
 881         collect_children();
 882
 883         if (readset)
 884                 xfree(readset);
 885         if (writeset)
 886                 xfree(writeset);
 887
 888         /* free all channels, no more reads and writes */
 889         channel_free_all();
 890
 891         /* free remaining sessions, e.g. remove wtmp entries */
 892         session_destroy_all(NULL);
 893 }
 894
 895 static void
 896 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
 897 {
 898         debug("Got %d/%u for keepalive", type, seq);
 899         /*
 900          * reset timeout, since we got a sane answer from the client.
 901          * even if this was generated by something other than
 902          * the bogus CHANNEL_REQUEST we send for keepalives.
 903          */
 904         packet_set_alive_timeouts(0);
 905 }
 906
 907 static void
 908 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
 909 {
 910         char *data;
 911         u_int data_len;
 912
 913         /* Stdin data from the client.  Append it to the buffer. */
 914         /* Ignore any data if the client has closed stdin. */
 915         if (fdin == -1)
 916                 return;
 917         data = packet_get_string(&data_len);
 918         packet_check_eom();
 919         buffer_append(&stdin_buffer, data, data_len);
 920         memset(data, 0, data_len);
 921         xfree(data);
 922 }
 923
 924 static void
 925 server_input_eof(int type, u_int32_t seq, void *ctxt)
 926 {
 927         /*
 928          * Eof from the client.  The stdin descriptor to the
 929          * program will be closed when all buffered data has
 930          * drained.
 931          */
 932         debug("EOF received for stdin.");
 933         packet_check_eom();
 934         stdin_eof = 1;
 935 }
 936
 937 static void
 938 server_input_window_size(int type, u_int32_t seq, void *ctxt)
 939 {
 940         u_int row = packet_get_int();
 941         u_int col = packet_get_int();
 942         u_int xpixel = packet_get_int();
 943         u_int ypixel = packet_get_int();
 944
 945         debug("Window change received.");
 946         packet_check_eom();
 947         if (fdin != -1)
 948                 pty_change_window_size(fdin, row, col, xpixel, ypixel);
 949 }
 950
 951 static Channel *
 952 server_request_direct_tcpip(void)
 953 {
 954         Channel *c = NULL;
 955         char *target, *originator;
 956         u_short target_port, originator_port;
 957
 958         target = packet_get_string(NULL);
 959         target_port = packet_get_int();
 960         originator = packet_get_string(NULL);
 961         originator_port = packet_get_int();
 962         packet_check_eom();
 963
 964         debug("server_request_direct_tcpip: originator %s port %d, target %s "
 965             "port %d", originator, originator_port, target, target_port);
 966
 967         /* XXX fine grained permissions */
 968         if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
 969             !no_port_forwarding_flag) {
 970                 c = channel_connect_to(target, target_port,
 971                     "direct-tcpip", "direct-tcpip");
 972         } else {
 973                 logit("refused local port forward: "
 974                     "originator %s port %d, target %s port %d",
 975                     originator, originator_port, target, target_port);
 976         }
 977
 978         xfree(originator);
 979         xfree(target);
 980
 981         return c;
 982 }
 983
 984 static Channel *
 985 server_request_tun(void)
 986 {
 987         Channel *c = NULL;
 988         int mode, tun;
 989         int sock;
 990
 991         mode = packet_get_int();
 992         switch (mode) {
 993         case SSH_TUNMODE_POINTOPOINT:
 994         case SSH_TUNMODE_ETHERNET:
 995                 break;
 996         default:
 997                 packet_send_debug("Unsupported tunnel device mode.");
 998                 return NULL;
 999         }
1000         if ((options.permit_tun & mode) == 0) {
1001                 packet_send_debug("Server has rejected tunnel device "
1002                     "forwarding");
1003                 return NULL;
1004         }
1005
1006         tun = packet_get_int();
1007         if (forced_tun_device != -1) {
1008                 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1009                         goto done;
1010                 tun = forced_tun_device;
1011         }
1012         sock = tun_open(tun, mode);
1013         if (sock < 0)
1014                 goto done;
1015         if (options.hpn_disabled)
1016                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1017                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1018                     "tun", 1);
1019         else
1020                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1021                     options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0,
1022                     "tun", 1);
1023         c->datagram = 1;
1024 #if defined(SSH_TUN_FILTER)
1025         if (mode == SSH_TUNMODE_POINTOPOINT)
1026                 channel_register_filter(c->self, sys_tun_infilter,
1027                     sys_tun_outfilter, NULL, NULL);
1028 #endif
1029
1030  done:
1031         if (c == NULL)
1032                 packet_send_debug("Failed to open the tunnel device.");
1033         return c;
1034 }
1035
1036 static Channel *
1037 server_request_session(void)
1038 {
1039         Channel *c;
1040
1041         debug("input_session_request");
1042         packet_check_eom();
1043
1044         if (no_more_sessions) {
1045                 packet_disconnect("Possible attack: attempt to open a session "
1046                     "after additional sessions disabled");
1047         }
1048
1049         /*
1050          * A server session has no fd to read or write until a
1051          * CHANNEL_REQUEST for a shell is made, so we set the type to
1052          * SSH_CHANNEL_LARVAL.  Additionally, a callback for handling all
1053          * CHANNEL_REQUEST messages is registered.
1054          */
1055         c = channel_new("session", SSH_CHANNEL_LARVAL,
1056             -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1057             0, "server-session", 1);
1058         if (!options.hpn_disabled && options.tcp_rcv_buf_poll)
1059                 c->dynamic_window = 1;
1060         if (session_open(the_authctxt, c->self) != 1) {
1061                 debug("session open failed, free channel %d", c->self);
1062                 channel_free(c);
1063                 return NULL;
1064         }
1065         channel_register_cleanup(c->self, session_close_by_channel, 0);
1066         return c;
1067 }
1068
1069 static void
1070 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1071 {
1072         Channel *c = NULL;
1073         char *ctype;
1074         int rchan;
1075         u_int rmaxpack, rwindow, len;
1076
1077         ctype = packet_get_string(&len);
1078         rchan = packet_get_int();
1079         rwindow = packet_get_int();
1080         rmaxpack = packet_get_int();
1081
1082         debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1083             ctype, rchan, rwindow, rmaxpack);
1084
1085         if (strcmp(ctype, "session") == 0) {
1086                 c = server_request_session();
1087         } else if (strcmp(ctype, "direct-tcpip") == 0) {
1088                 c = server_request_direct_tcpip();
1089         } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1090                 c = server_request_tun();
1091         }
1092         if (c != NULL) {
1093                 debug("server_input_channel_open: confirm %s", ctype);
1094                 c->remote_id = rchan;
1095                 c->remote_window = rwindow;
1096                 c->remote_maxpacket = rmaxpack;
1097                 if (c->type != SSH_CHANNEL_CONNECTING) {
1098                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1099                         packet_put_int(c->remote_id);
1100                         packet_put_int(c->self);
1101                         packet_put_int(c->local_window);
1102                         packet_put_int(c->local_maxpacket);
1103                         packet_send();
1104                 }
1105         } else {
1106                 debug("server_input_channel_open: failure %s", ctype);
1107                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1108                 packet_put_int(rchan);
1109                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1110                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1111                         packet_put_cstring("open failed");
1112                         packet_put_cstring("");
1113                 }
1114                 packet_send();
1115         }
1116         xfree(ctype);
1117 }
1118
1119 static void
1120 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1121 {
1122         char *rtype;
1123         int want_reply;
1124         int success = 0, allocated_listen_port = 0;
1125
1126         rtype = packet_get_string(NULL);
1127         want_reply = packet_get_char();
1128         debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1129
1130         /* -R style forwarding */
1131         if (strcmp(rtype, "tcpip-forward") == 0) {
1132                 struct passwd *pw;
1133                 char *listen_address;
1134                 u_short listen_port;
1135
1136                 pw = the_authctxt->pw;
1137                 if (pw == NULL || !the_authctxt->valid)
1138                         fatal("server_input_global_request: no/invalid user");
1139                 listen_address = packet_get_string(NULL);
1140                 listen_port = (u_short)packet_get_int();
1141                 debug("server_input_global_request: tcpip-forward listen %s port %d",
1142                     listen_address, listen_port);
1143
1144                 /* check permissions */
1145                 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
1146                     no_port_forwarding_flag ||
1147                     (!want_reply && listen_port == 0)
1148 #ifndef NO_IPPORT_RESERVED_CONCEPT
1149                     || (listen_port != 0 && listen_port < IPPORT_RESERVED &&
1150                     pw->pw_uid != 0)
1151 #endif
1152                     ) {
1153                         success = 0;
1154                         packet_send_debug("Server has disabled port forwarding.");
1155                 } else {
1156                         /* Start listening on the port */
1157                         success = channel_setup_remote_fwd_listener(
1158                             listen_address, listen_port,
1159                             &allocated_listen_port, options.gateway_ports);
1160                 }
1161                 xfree(listen_address);
1162         } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1163                 char *cancel_address;
1164                 u_short cancel_port;
1165
1166                 cancel_address = packet_get_string(NULL);
1167                 cancel_port = (u_short)packet_get_int();
1168                 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1169                     cancel_address, cancel_port);
1170
1171                 success = channel_cancel_rport_listener(cancel_address,
1172                     cancel_port);
1173                 xfree(cancel_address);
1174         } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1175                 no_more_sessions = 1;
1176                 success = 1;
1177         }
1178         if (want_reply) {
1179                 packet_start(success ?
1180                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1181                 if (success && allocated_listen_port > 0)
1182                         packet_put_int(allocated_listen_port);
1183                 packet_send();
1184                 packet_write_wait();
1185         }
1186         xfree(rtype);
1187 }
1188
1189 static void
1190 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1191 {
1192         Channel *c;
1193         int id, reply, success = 0;
1194         char *rtype;
1195
1196         id = packet_get_int();
1197         rtype = packet_get_string(NULL);
1198         reply = packet_get_char();
1199
1200         debug("server_input_channel_req: channel %d request %s reply %d",
1201             id, rtype, reply);
1202
1203         if ((c = channel_lookup(id)) == NULL)
1204                 packet_disconnect("server_input_channel_req: "
1205                     "unknown channel %d", id);
1206         if (!strcmp(rtype, "eow@openssh.com")) {
1207                 packet_check_eom();
1208                 chan_rcvd_eow(c);
1209         } else if ((c->type == SSH_CHANNEL_LARVAL ||
1210             c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1211                 success = session_input_channel_req(c, rtype);
1212         if (reply) {
1213                 packet_start(success ?
1214                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1215                 packet_put_int(c->remote_id);
1216                 packet_send();
1217         }
1218         xfree(rtype);
1219 }
1220
1221 static void
1222 server_init_dispatch_20(void)
1223 {
1224         debug("server_init_dispatch_20");
1225         dispatch_init(&dispatch_protocol_error);
1226         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1227         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1228         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1229         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1230         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1231         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1232         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1233         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1234         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1235         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1236         /* client_alive */
1237         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1238         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1239         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1240         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1241         /* rekeying */
1242         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1243 }
1244 static void
1245 server_init_dispatch_13(void)
1246 {
1247         debug("server_init_dispatch_13");
1248         dispatch_init(NULL);
1249         dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1250         dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1251         dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1252         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1253         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1254         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1255         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1256         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1257         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1258 }
1259 static void
1260 server_init_dispatch_15(void)
1261 {
1262         server_init_dispatch_13();
1263         debug("server_init_dispatch_15");
1264         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1265         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1266 }
1267 static void
1268 server_init_dispatch(void)
1269 {
1270         if (compat20)
1271                 server_init_dispatch_20();
1272         else if (compat13)
1273                 server_init_dispatch_13();
1274         else
1275                 server_init_dispatch_15();
1276 }