crypto/openssh/serverloop.c

   1 /* $OpenBSD: serverloop.c,v 1.170 2014/02/02 03:44:31 djm 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                 (void)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_int64_t 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 =
 309                     (u_int64_t)options.client_alive_interval * 1000;
 310         }
 311
 312         if (compat20) {
 313 #if 0
 314                 /* wrong: bad condition XXX */
 315                 if (channel_not_very_much_buffered_data())
 316 #endif
 317                 FD_SET(connection_in, *readsetp);
 318         } else {
 319                 /*
 320                  * Read packets from the client unless we have too much
 321                  * buffered stdin or channel data.
 322                  */
 323                 if (buffer_len(&stdin_buffer) < buffer_high &&
 324                     channel_not_very_much_buffered_data())
 325                         FD_SET(connection_in, *readsetp);
 326                 /*
 327                  * If there is not too much data already buffered going to
 328                  * the client, try to get some more data from the program.
 329                  */
 330                 if (packet_not_very_much_data_to_write()) {
 331                         program_alive_scheduled = child_terminated;
 332                         if (!fdout_eof)
 333                                 FD_SET(fdout, *readsetp);
 334                         if (!fderr_eof)
 335                                 FD_SET(fderr, *readsetp);
 336                 }
 337                 /*
 338                  * If we have buffered data, try to write some of that data
 339                  * to the program.
 340                  */
 341                 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
 342                         FD_SET(fdin, *writesetp);
 343         }
 344         notify_prepare(*readsetp);
 345
 346         /*
 347          * If we have buffered packet data going to the client, mark that
 348          * descriptor.
 349          */
 350         if (packet_have_data_to_write())
 351                 FD_SET(connection_out, *writesetp);
 352
 353         /*
 354          * If child has terminated and there is enough buffer space to read
 355          * from it, then read as much as is available and exit.
 356          */
 357         if (child_terminated && packet_not_very_much_data_to_write())
 358                 if (max_time_milliseconds == 0 || client_alive_scheduled)
 359                         max_time_milliseconds = 100;
 360
 361         if (max_time_milliseconds == 0)
 362                 tvp = NULL;
 363         else {
 364                 tv.tv_sec = max_time_milliseconds / 1000;
 365                 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
 366                 tvp = &tv;
 367         }
 368
 369         /* Wait for something to happen, or the timeout to expire. */
 370         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 371
 372         if (ret == -1) {
 373                 memset(*readsetp, 0, *nallocp);
 374                 memset(*writesetp, 0, *nallocp);
 375                 if (errno != EINTR)
 376                         error("select: %.100s", strerror(errno));
 377         } else {
 378                 if (ret == 0 && client_alive_scheduled)
 379                         client_alive_check();
 380                 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
 381                         if (!fdout_eof)
 382                                 FD_SET(fdout, *readsetp);
 383                         if (!fderr_eof)
 384                                 FD_SET(fderr, *readsetp);
 385                 }
 386         }
 387
 388         notify_done(*readsetp);
 389 }
 390
 391 /*
 392  * Processes input from the client and the program.  Input data is stored
 393  * in buffers and processed later.
 394  */
 395 static void
 396 process_input(fd_set *readset)
 397 {
 398         int len;
 399         char buf[16384];
 400
 401         /* Read and buffer any input data from the client. */
 402         if (FD_ISSET(connection_in, readset)) {
 403                 int cont = 0;
 404                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 405                 if (len == 0) {
 406                         if (cont)
 407                                 return;
 408                         verbose("Connection closed by %.100s",
 409                             get_remote_ipaddr());
 410                         connection_closed = 1;
 411                         if (compat20)
 412                                 return;
 413                         cleanup_exit(255);
 414                 } else if (len < 0) {
 415                         if (errno != EINTR && errno != EAGAIN &&
 416                             errno != EWOULDBLOCK) {
 417                                 verbose("Read error from remote host "
 418                                     "%.100s: %.100s",
 419                                     get_remote_ipaddr(), strerror(errno));
 420                                 cleanup_exit(255);
 421                         }
 422                 } else {
 423                         /* Buffer any received data. */
 424                         packet_process_incoming(buf, len);
 425                 }
 426         }
 427         if (compat20)
 428                 return;
 429
 430         /* Read and buffer any available stdout data from the program. */
 431         if (!fdout_eof && FD_ISSET(fdout, readset)) {
 432                 errno = 0;
 433                 len = read(fdout, buf, sizeof(buf));
 434                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 435                     errno == EWOULDBLOCK) && !child_terminated))) {
 436                         /* do nothing */
 437 #ifndef PTY_ZEROREAD
 438                 } else if (len <= 0) {
 439 #else
 440                 } else if ((!isatty(fdout) && len <= 0) ||
 441                     (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
 442 #endif
 443                         fdout_eof = 1;
 444                 } else {
 445                         buffer_append(&stdout_buffer, buf, len);
 446                         fdout_bytes += len;
 447                 }
 448         }
 449         /* Read and buffer any available stderr data from the program. */
 450         if (!fderr_eof && FD_ISSET(fderr, readset)) {
 451                 errno = 0;
 452                 len = read(fderr, buf, sizeof(buf));
 453                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 454                     errno == EWOULDBLOCK) && !child_terminated))) {
 455                         /* do nothing */
 456 #ifndef PTY_ZEROREAD
 457                 } else if (len <= 0) {
 458 #else
 459                 } else if ((!isatty(fderr) && len <= 0) ||
 460                     (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
 461 #endif
 462                         fderr_eof = 1;
 463                 } else {
 464                         buffer_append(&stderr_buffer, buf, len);
 465                 }
 466         }
 467 }
 468
 469 /*
 470  * Sends data from internal buffers to client program stdin.
 471  */
 472 static void
 473 process_output(fd_set *writeset)
 474 {
 475         struct termios tio;
 476         u_char *data;
 477         u_int dlen;
 478         int len;
 479
 480         /* Write buffered data to program stdin. */
 481         if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
 482                 data = buffer_ptr(&stdin_buffer);
 483                 dlen = buffer_len(&stdin_buffer);
 484                 len = write(fdin, data, dlen);
 485                 if (len < 0 &&
 486                     (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
 487                         /* do nothing */
 488                 } else if (len <= 0) {
 489                         if (fdin != fdout)
 490                                 close(fdin);
 491                         else
 492                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 493                         fdin = -1;
 494                 } else {
 495                         /* Successful write. */
 496                         if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
 497                             tcgetattr(fdin, &tio) == 0 &&
 498                             !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
 499                                 /*
 500                                  * Simulate echo to reduce the impact of
 501                                  * traffic analysis
 502                                  */
 503                                 packet_send_ignore(len);
 504                                 packet_send();
 505                         }
 506                         /* Consume the data from the buffer. */
 507                         buffer_consume(&stdin_buffer, len);
 508                         /* Update the count of bytes written to the program. */
 509                         stdin_bytes += len;
 510                 }
 511         }
 512         /* Send any buffered packet data to the client. */
 513         if (FD_ISSET(connection_out, writeset))
 514                 packet_write_poll();
 515 }
 516
 517 /*
 518  * Wait until all buffered output has been sent to the client.
 519  * This is used when the program terminates.
 520  */
 521 static void
 522 drain_output(void)
 523 {
 524         /* Send any buffered stdout data to the client. */
 525         if (buffer_len(&stdout_buffer) > 0) {
 526                 packet_start(SSH_SMSG_STDOUT_DATA);
 527                 packet_put_string(buffer_ptr(&stdout_buffer),
 528                                   buffer_len(&stdout_buffer));
 529                 packet_send();
 530                 /* Update the count of sent bytes. */
 531                 stdout_bytes += buffer_len(&stdout_buffer);
 532         }
 533         /* Send any buffered stderr data to the client. */
 534         if (buffer_len(&stderr_buffer) > 0) {
 535                 packet_start(SSH_SMSG_STDERR_DATA);
 536                 packet_put_string(buffer_ptr(&stderr_buffer),
 537                                   buffer_len(&stderr_buffer));
 538                 packet_send();
 539                 /* Update the count of sent bytes. */
 540                 stderr_bytes += buffer_len(&stderr_buffer);
 541         }
 542         /* Wait until all buffered data has been written to the client. */
 543         packet_write_wait();
 544 }
 545
 546 static void
 547 process_buffered_input_packets(void)
 548 {
 549         dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
 550 }
 551
 552 /*
 553  * Performs the interactive session.  This handles data transmission between
 554  * the client and the program.  Note that the notion of stdin, stdout, and
 555  * stderr in this function is sort of reversed: this function writes to
 556  * stdin (of the child program), and reads from stdout and stderr (of the
 557  * child program).
 558  */
 559 void
 560 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 561 {
 562         fd_set *readset = NULL, *writeset = NULL;
 563         int max_fd = 0;
 564         u_int nalloc = 0;
 565         int wait_status;        /* Status returned by wait(). */
 566         pid_t wait_pid;         /* pid returned by wait(). */
 567         int waiting_termination = 0;    /* Have displayed waiting close message. */
 568         u_int64_t max_time_milliseconds;
 569         u_int previous_stdout_buffer_bytes;
 570         u_int stdout_buffer_bytes;
 571         int type;
 572
 573         debug("Entering interactive session.");
 574
 575         /* Initialize the SIGCHLD kludge. */
 576         child_terminated = 0;
 577         mysignal(SIGCHLD, sigchld_handler);
 578
 579         if (!use_privsep) {
 580                 signal(SIGTERM, sigterm_handler);
 581                 signal(SIGINT, sigterm_handler);
 582                 signal(SIGQUIT, sigterm_handler);
 583         }
 584
 585         /* Initialize our global variables. */
 586         fdin = fdin_arg;
 587         fdout = fdout_arg;
 588         fderr = fderr_arg;
 589
 590         /* nonblocking IO */
 591         set_nonblock(fdin);
 592         set_nonblock(fdout);
 593         /* we don't have stderr for interactive terminal sessions, see below */
 594         if (fderr != -1)
 595                 set_nonblock(fderr);
 596
 597         if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
 598                 fdin_is_tty = 1;
 599
 600         connection_in = packet_get_connection_in();
 601         connection_out = packet_get_connection_out();
 602
 603         notify_setup();
 604
 605         previous_stdout_buffer_bytes = 0;
 606
 607         /* Set approximate I/O buffer size. */
 608         if (packet_is_interactive())
 609                 buffer_high = 4096;
 610         else
 611                 buffer_high = 64 * 1024;
 612
 613 #if 0
 614         /* Initialize max_fd to the maximum of the known file descriptors. */
 615         max_fd = MAX(connection_in, connection_out);
 616         max_fd = MAX(max_fd, fdin);
 617         max_fd = MAX(max_fd, fdout);
 618         if (fderr != -1)
 619                 max_fd = MAX(max_fd, fderr);
 620 #endif
 621
 622         /* Initialize Initialize buffers. */
 623         buffer_init(&stdin_buffer);
 624         buffer_init(&stdout_buffer);
 625         buffer_init(&stderr_buffer);
 626
 627         /*
 628          * If we have no separate fderr (which is the case when we have a pty
 629          * - there we cannot make difference between data sent to stdout and
 630          * stderr), indicate that we have seen an EOF from stderr.  This way
 631          * we don't need to check the descriptor everywhere.
 632          */
 633         if (fderr == -1)
 634                 fderr_eof = 1;
 635
 636         server_init_dispatch();
 637
 638         /* Main loop of the server for the interactive session mode. */
 639         for (;;) {
 640
 641                 /* Process buffered packets from the client. */
 642                 process_buffered_input_packets();
 643
 644                 /*
 645                  * If we have received eof, and there is no more pending
 646                  * input data, cause a real eof by closing fdin.
 647                  */
 648                 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
 649                         if (fdin != fdout)
 650                                 close(fdin);
 651                         else
 652                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 653                         fdin = -1;
 654                 }
 655                 /* Make packets from buffered stderr data to send to the client. */
 656                 make_packets_from_stderr_data();
 657
 658                 /*
 659                  * Make packets from buffered stdout data to send to the
 660                  * client. If there is very little to send, this arranges to
 661                  * not send them now, but to wait a short while to see if we
 662                  * are getting more data. This is necessary, as some systems
 663                  * wake up readers from a pty after each separate character.
 664                  */
 665                 max_time_milliseconds = 0;
 666                 stdout_buffer_bytes = buffer_len(&stdout_buffer);
 667                 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
 668                     stdout_buffer_bytes != previous_stdout_buffer_bytes) {
 669                         /* try again after a while */
 670                         max_time_milliseconds = 10;
 671                 } else {
 672                         /* Send it now. */
 673                         make_packets_from_stdout_data();
 674                 }
 675                 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
 676
 677                 /* Send channel data to the client. */
 678                 if (packet_not_very_much_data_to_write())
 679                         channel_output_poll();
 680
 681                 /*
 682                  * Bail out of the loop if the program has closed its output
 683                  * descriptors, and we have no more data to send to the
 684                  * client, and there is no pending buffered data.
 685                  */
 686                 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
 687                     buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
 688                         if (!channel_still_open())
 689                                 break;
 690                         if (!waiting_termination) {
 691                                 const char *s = "Waiting for forwarded connections to terminate...\r\n";
 692                                 char *cp;
 693                                 waiting_termination = 1;
 694                                 buffer_append(&stderr_buffer, s, strlen(s));
 695
 696                                 /* Display list of open channels. */
 697                                 cp = channel_open_message();
 698                                 buffer_append(&stderr_buffer, cp, strlen(cp));
 699                                 free(cp);
 700                         }
 701                 }
 702                 max_fd = MAX(connection_in, connection_out);
 703                 max_fd = MAX(max_fd, fdin);
 704                 max_fd = MAX(max_fd, fdout);
 705                 max_fd = MAX(max_fd, fderr);
 706                 max_fd = MAX(max_fd, notify_pipe[0]);
 707
 708                 /* Sleep in select() until we can do something. */
 709                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 710                     &nalloc, max_time_milliseconds);
 711
 712                 if (received_sigterm) {
 713                         logit("Exiting on signal %d", (int)received_sigterm);
 714                         /* Clean up sessions, utmp, etc. */
 715                         cleanup_exit(255);
 716                 }
 717
 718                 /* Process any channel events. */
 719                 channel_after_select(readset, writeset);
 720
 721                 /* Process input from the client and from program stdout/stderr. */
 722                 process_input(readset);
 723
 724                 /* Process output to the client and to program stdin. */
 725                 process_output(writeset);
 726         }
 727         free(readset);
 728         free(writeset);
 729
 730         /* Cleanup and termination code. */
 731
 732         /* Wait until all output has been sent to the client. */
 733         drain_output();
 734
 735         debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
 736             stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
 737
 738         /* Free and clear the buffers. */
 739         buffer_free(&stdin_buffer);
 740         buffer_free(&stdout_buffer);
 741         buffer_free(&stderr_buffer);
 742
 743         /* Close the file descriptors. */
 744         if (fdout != -1)
 745                 close(fdout);
 746         fdout = -1;
 747         fdout_eof = 1;
 748         if (fderr != -1)
 749                 close(fderr);
 750         fderr = -1;
 751         fderr_eof = 1;
 752         if (fdin != -1)
 753                 close(fdin);
 754         fdin = -1;
 755
 756         channel_free_all();
 757
 758         /* We no longer want our SIGCHLD handler to be called. */
 759         mysignal(SIGCHLD, SIG_DFL);
 760
 761         while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
 762                 if (errno != EINTR)
 763                         packet_disconnect("wait: %.100s", strerror(errno));
 764         if (wait_pid != pid)
 765                 error("Strange, wait returned pid %ld, expected %ld",
 766                     (long)wait_pid, (long)pid);
 767
 768         /* Check if it exited normally. */
 769         if (WIFEXITED(wait_status)) {
 770                 /* Yes, normal exit.  Get exit status and send it to the client. */
 771                 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
 772                 packet_start(SSH_SMSG_EXITSTATUS);
 773                 packet_put_int(WEXITSTATUS(wait_status));
 774                 packet_send();
 775                 packet_write_wait();
 776
 777                 /*
 778                  * Wait for exit confirmation.  Note that there might be
 779                  * other packets coming before it; however, the program has
 780                  * already died so we just ignore them.  The client is
 781                  * supposed to respond with the confirmation when it receives
 782                  * the exit status.
 783                  */
 784                 do {
 785                         type = packet_read();
 786                 }
 787                 while (type != SSH_CMSG_EXIT_CONFIRMATION);
 788
 789                 debug("Received exit confirmation.");
 790                 return;
 791         }
 792         /* Check if the program terminated due to a signal. */
 793         if (WIFSIGNALED(wait_status))
 794                 packet_disconnect("Command terminated on signal %d.",
 795                                   WTERMSIG(wait_status));
 796
 797         /* Some weird exit cause.  Just exit. */
 798         packet_disconnect("wait returned status %04x.", wait_status);
 799         /* NOTREACHED */
 800 }
 801
 802 static void
 803 collect_children(void)
 804 {
 805         pid_t pid;
 806         sigset_t oset, nset;
 807         int status;
 808
 809         /* block SIGCHLD while we check for dead children */
 810         sigemptyset(&nset);
 811         sigaddset(&nset, SIGCHLD);
 812         sigprocmask(SIG_BLOCK, &nset, &oset);
 813         if (child_terminated) {
 814                 debug("Received SIGCHLD.");
 815                 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
 816                     (pid < 0 && errno == EINTR))
 817                         if (pid > 0)
 818                                 session_close_by_pid(pid, status);
 819                 child_terminated = 0;
 820         }
 821         sigprocmask(SIG_SETMASK, &oset, NULL);
 822 }
 823
 824 void
 825 server_loop2(Authctxt *authctxt)
 826 {
 827         fd_set *readset = NULL, *writeset = NULL;
 828         int rekeying = 0, max_fd;
 829         u_int nalloc = 0;
 830         u_int64_t rekey_timeout_ms = 0;
 831
 832         debug("Entering interactive session for SSH2.");
 833
 834         mysignal(SIGCHLD, sigchld_handler);
 835         child_terminated = 0;
 836         connection_in = packet_get_connection_in();
 837         connection_out = packet_get_connection_out();
 838
 839         if (!use_privsep) {
 840                 signal(SIGTERM, sigterm_handler);
 841                 signal(SIGINT, sigterm_handler);
 842                 signal(SIGQUIT, sigterm_handler);
 843         }
 844
 845         notify_setup();
 846
 847         max_fd = MAX(connection_in, connection_out);
 848         max_fd = MAX(max_fd, notify_pipe[0]);
 849
 850         server_init_dispatch();
 851
 852         for (;;) {
 853                 process_buffered_input_packets();
 854
 855                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 856
 857                 if (!rekeying && packet_not_very_much_data_to_write())
 858                         channel_output_poll();
 859                 if (options.rekey_interval > 0 && compat20 && !rekeying)
 860                         rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
 861                 else
 862                         rekey_timeout_ms = 0;
 863
 864                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 865                     &nalloc, rekey_timeout_ms);
 866
 867                 if (received_sigterm) {
 868                         logit("Exiting on signal %d", (int)received_sigterm);
 869                         /* Clean up sessions, utmp, etc. */
 870                         cleanup_exit(255);
 871                 }
 872
 873                 collect_children();
 874                 if (!rekeying) {
 875                         channel_after_select(readset, writeset);
 876                         if (packet_need_rekeying()) {
 877                                 debug("need rekeying");
 878                                 xxx_kex->done = 0;
 879                                 kex_send_kexinit(xxx_kex);
 880                         }
 881                 }
 882                 process_input(readset);
 883                 if (connection_closed)
 884                         break;
 885                 process_output(writeset);
 886         }
 887         collect_children();
 888
 889         free(readset);
 890         free(writeset);
 891
 892         /* free all channels, no more reads and writes */
 893         channel_free_all();
 894
 895         /* free remaining sessions, e.g. remove wtmp entries */
 896         session_destroy_all(NULL);
 897 }
 898
 899 static void
 900 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
 901 {
 902         debug("Got %d/%u for keepalive", type, seq);
 903         /*
 904          * reset timeout, since we got a sane answer from the client.
 905          * even if this was generated by something other than
 906          * the bogus CHANNEL_REQUEST we send for keepalives.
 907          */
 908         packet_set_alive_timeouts(0);
 909 }
 910
 911 static void
 912 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
 913 {
 914         char *data;
 915         u_int data_len;
 916
 917         /* Stdin data from the client.  Append it to the buffer. */
 918         /* Ignore any data if the client has closed stdin. */
 919         if (fdin == -1)
 920                 return;
 921         data = packet_get_string(&data_len);
 922         packet_check_eom();
 923         buffer_append(&stdin_buffer, data, data_len);
 924         explicit_bzero(data, data_len);
 925         free(data);
 926 }
 927
 928 static void
 929 server_input_eof(int type, u_int32_t seq, void *ctxt)
 930 {
 931         /*
 932          * Eof from the client.  The stdin descriptor to the
 933          * program will be closed when all buffered data has
 934          * drained.
 935          */
 936         debug("EOF received for stdin.");
 937         packet_check_eom();
 938         stdin_eof = 1;
 939 }
 940
 941 static void
 942 server_input_window_size(int type, u_int32_t seq, void *ctxt)
 943 {
 944         u_int row = packet_get_int();
 945         u_int col = packet_get_int();
 946         u_int xpixel = packet_get_int();
 947         u_int ypixel = packet_get_int();
 948
 949         debug("Window change received.");
 950         packet_check_eom();
 951         if (fdin != -1)
 952                 pty_change_window_size(fdin, row, col, xpixel, ypixel);
 953 }
 954
 955 static Channel *
 956 server_request_direct_tcpip(void)
 957 {
 958         Channel *c = NULL;
 959         char *target, *originator;
 960         u_short target_port, originator_port;
 961
 962         target = packet_get_string(NULL);
 963         target_port = packet_get_int();
 964         originator = packet_get_string(NULL);
 965         originator_port = packet_get_int();
 966         packet_check_eom();
 967
 968         debug("server_request_direct_tcpip: originator %s port %d, target %s "
 969             "port %d", originator, originator_port, target, target_port);
 970
 971         /* XXX fine grained permissions */
 972         if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
 973             !no_port_forwarding_flag) {
 974                 c = channel_connect_to(target, target_port,
 975                     "direct-tcpip", "direct-tcpip");
 976         } else {
 977                 logit("refused local port forward: "
 978                     "originator %s port %d, target %s port %d",
 979                     originator, originator_port, target, target_port);
 980         }
 981
 982         free(originator);
 983         free(target);
 984
 985         return c;
 986 }
 987
 988 static Channel *
 989 server_request_tun(void)
 990 {
 991         Channel *c = NULL;
 992         int mode, tun;
 993         int sock;
 994
 995         mode = packet_get_int();
 996         switch (mode) {
 997         case SSH_TUNMODE_POINTOPOINT:
 998         case SSH_TUNMODE_ETHERNET:
 999                 break;
1000         default:
1001                 packet_send_debug("Unsupported tunnel device mode.");
1002                 return NULL;
1003         }
1004         if ((options.permit_tun & mode) == 0) {
1005                 packet_send_debug("Server has rejected tunnel device "
1006                     "forwarding");
1007                 return NULL;
1008         }
1009
1010         tun = packet_get_int();
1011         if (forced_tun_device != -1) {
1012                 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1013                         goto done;
1014                 tun = forced_tun_device;
1015         }
1016         sock = tun_open(tun, mode);
1017         if (sock < 0)
1018                 goto done;
1019         if (options.hpn_disabled)
1020                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1021                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1022                     "tun", 1);
1023         else
1024                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1025                     options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0,
1026                     "tun", 1);
1027         c->datagram = 1;
1028 #if defined(SSH_TUN_FILTER)
1029         if (mode == SSH_TUNMODE_POINTOPOINT)
1030                 channel_register_filter(c->self, sys_tun_infilter,
1031                     sys_tun_outfilter, NULL, NULL);
1032 #endif
1033
1034  done:
1035         if (c == NULL)
1036                 packet_send_debug("Failed to open the tunnel device.");
1037         return c;
1038 }
1039
1040 static Channel *
1041 server_request_session(void)
1042 {
1043         Channel *c;
1044
1045         debug("input_session_request");
1046         packet_check_eom();
1047
1048         if (no_more_sessions) {
1049                 packet_disconnect("Possible attack: attempt to open a session "
1050                     "after additional sessions disabled");
1051         }
1052
1053         /*
1054          * A server session has no fd to read or write until a
1055          * CHANNEL_REQUEST for a shell is made, so we set the type to
1056          * SSH_CHANNEL_LARVAL.  Additionally, a callback for handling all
1057          * CHANNEL_REQUEST messages is registered.
1058          */
1059         c = channel_new("session", SSH_CHANNEL_LARVAL,
1060             -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1061             0, "server-session", 1);
1062         if (!options.hpn_disabled && options.tcp_rcv_buf_poll)
1063                 c->dynamic_window = 1;
1064         if (session_open(the_authctxt, c->self) != 1) {
1065                 debug("session open failed, free channel %d", c->self);
1066                 channel_free(c);
1067                 return NULL;
1068         }
1069         channel_register_cleanup(c->self, session_close_by_channel, 0);
1070         return c;
1071 }
1072
1073 static void
1074 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1075 {
1076         Channel *c = NULL;
1077         char *ctype;
1078         int rchan;
1079         u_int rmaxpack, rwindow, len;
1080
1081         ctype = packet_get_string(&len);
1082         rchan = packet_get_int();
1083         rwindow = packet_get_int();
1084         rmaxpack = packet_get_int();
1085
1086         debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1087             ctype, rchan, rwindow, rmaxpack);
1088
1089         if (strcmp(ctype, "session") == 0) {
1090                 c = server_request_session();
1091         } else if (strcmp(ctype, "direct-tcpip") == 0) {
1092                 c = server_request_direct_tcpip();
1093         } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1094                 c = server_request_tun();
1095         }
1096         if (c != NULL) {
1097                 debug("server_input_channel_open: confirm %s", ctype);
1098                 c->remote_id = rchan;
1099                 c->remote_window = rwindow;
1100                 c->remote_maxpacket = rmaxpack;
1101                 if (c->type != SSH_CHANNEL_CONNECTING) {
1102                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1103                         packet_put_int(c->remote_id);
1104                         packet_put_int(c->self);
1105                         packet_put_int(c->local_window);
1106                         packet_put_int(c->local_maxpacket);
1107                         packet_send();
1108                 }
1109         } else {
1110                 debug("server_input_channel_open: failure %s", ctype);
1111                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1112                 packet_put_int(rchan);
1113                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1114                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1115                         packet_put_cstring("open failed");
1116                         packet_put_cstring("");
1117                 }
1118                 packet_send();
1119         }
1120         free(ctype);
1121 }
1122
1123 static void
1124 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1125 {
1126         char *rtype;
1127         int want_reply;
1128         int success = 0, allocated_listen_port = 0;
1129
1130         rtype = packet_get_string(NULL);
1131         want_reply = packet_get_char();
1132         debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1133
1134         /* -R style forwarding */
1135         if (strcmp(rtype, "tcpip-forward") == 0) {
1136                 struct passwd *pw;
1137                 char *listen_address;
1138                 u_short listen_port;
1139
1140                 pw = the_authctxt->pw;
1141                 if (pw == NULL || !the_authctxt->valid)
1142                         fatal("server_input_global_request: no/invalid user");
1143                 listen_address = packet_get_string(NULL);
1144                 listen_port = (u_short)packet_get_int();
1145                 debug("server_input_global_request: tcpip-forward listen %s port %d",
1146                     listen_address, listen_port);
1147
1148                 /* check permissions */
1149                 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
1150                     no_port_forwarding_flag ||
1151                     (!want_reply && listen_port == 0)
1152 #ifndef NO_IPPORT_RESERVED_CONCEPT
1153                     || (listen_port != 0 && listen_port < IPPORT_RESERVED &&
1154                     pw->pw_uid != 0)
1155 #endif
1156                     ) {
1157                         success = 0;
1158                         packet_send_debug("Server has disabled port forwarding.");
1159                 } else {
1160                         /* Start listening on the port */
1161                         success = channel_setup_remote_fwd_listener(
1162                             listen_address, listen_port,
1163                             &allocated_listen_port, options.gateway_ports);
1164                 }
1165                 free(listen_address);
1166         } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1167                 char *cancel_address;
1168                 u_short cancel_port;
1169
1170                 cancel_address = packet_get_string(NULL);
1171                 cancel_port = (u_short)packet_get_int();
1172                 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1173                     cancel_address, cancel_port);
1174
1175                 success = channel_cancel_rport_listener(cancel_address,
1176                     cancel_port);
1177                 free(cancel_address);
1178         } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1179                 no_more_sessions = 1;
1180                 success = 1;
1181         }
1182         if (want_reply) {
1183                 packet_start(success ?
1184                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1185                 if (success && allocated_listen_port > 0)
1186                         packet_put_int(allocated_listen_port);
1187                 packet_send();
1188                 packet_write_wait();
1189         }
1190         free(rtype);
1191 }
1192
1193 static void
1194 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1195 {
1196         Channel *c;
1197         int id, reply, success = 0;
1198         char *rtype;
1199
1200         id = packet_get_int();
1201         rtype = packet_get_string(NULL);
1202         reply = packet_get_char();
1203
1204         debug("server_input_channel_req: channel %d request %s reply %d",
1205             id, rtype, reply);
1206
1207         if ((c = channel_lookup(id)) == NULL)
1208                 packet_disconnect("server_input_channel_req: "
1209                     "unknown channel %d", id);
1210         if (!strcmp(rtype, "eow@openssh.com")) {
1211                 packet_check_eom();
1212                 chan_rcvd_eow(c);
1213         } else if ((c->type == SSH_CHANNEL_LARVAL ||
1214             c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1215                 success = session_input_channel_req(c, rtype);
1216         if (reply) {
1217                 packet_start(success ?
1218                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1219                 packet_put_int(c->remote_id);
1220                 packet_send();
1221         }
1222         free(rtype);
1223 }
1224
1225 static void
1226 server_init_dispatch_20(void)
1227 {
1228         debug("server_init_dispatch_20");
1229         dispatch_init(&dispatch_protocol_error);
1230         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1231         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1232         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1233         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1234         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1235         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1236         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1237         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1238         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1239         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1240         /* client_alive */
1241         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1242         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1243         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1244         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1245         /* rekeying */
1246         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1247 }
1248 static void
1249 server_init_dispatch_13(void)
1250 {
1251         debug("server_init_dispatch_13");
1252         dispatch_init(NULL);
1253         dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1254         dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1255         dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1256         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1257         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1258         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1259         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1260         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1261         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1262 }
1263 static void
1264 server_init_dispatch_15(void)
1265 {
1266         server_init_dispatch_13();
1267         debug("server_init_dispatch_15");
1268         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1269         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1270 }
1271 static void
1272 server_init_dispatch(void)
1273 {
1274         if (compat20)
1275                 server_init_dispatch_20();
1276         else if (compat13)
1277                 server_init_dispatch_13();
1278         else
1279                 server_init_dispatch_15();
1280 }