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 __RCSID("$FreeBSD$");
  41
  42 #include <sys/types.h>
  43 #include <sys/param.h>
  44 #include <sys/wait.h>
  45 #include <sys/socket.h>
  46 #ifdef HAVE_SYS_TIME_H
  47 # include <sys/time.h>
  48 #endif
  49
  50 #include <netinet/in.h>
  51
  52 #include <errno.h>
  53 #include <fcntl.h>
  54 #include <pwd.h>
  55 #include <signal.h>
  56 #include <string.h>
  57 #include <termios.h>
  58 #include <unistd.h>
  59 #include <stdarg.h>
  60
  61 #include "openbsd-compat/sys-queue.h"
  62 #include "xmalloc.h"
  63 #include "packet.h"
  64 #include "buffer.h"
  65 #include "log.h"
  66 #include "servconf.h"
  67 #include "canohost.h"
  68 #include "sshpty.h"
  69 #include "channels.h"
  70 #include "compat.h"
  71 #include "ssh1.h"
  72 #include "ssh2.h"
  73 #include "key.h"
  74 #include "cipher.h"
  75 #include "kex.h"
  76 #include "hostfile.h"
  77 #include "auth.h"
  78 #include "session.h"
  79 #include "dispatch.h"
  80 #include "auth-options.h"
  81 #include "serverloop.h"
  82 #include "misc.h"
  83 #include "roaming.h"
  84
  85 extern ServerOptions options;
  86
  87 /* XXX */
  88 extern Kex *xxx_kex;
  89 extern Authctxt *the_authctxt;
  90 extern int use_privsep;
  91
  92 static Buffer stdin_buffer;     /* Buffer for stdin data. */
  93 static Buffer stdout_buffer;    /* Buffer for stdout data. */
  94 static Buffer stderr_buffer;    /* Buffer for stderr data. */
  95 static int fdin;                /* Descriptor for stdin (for writing) */
  96 static int fdout;               /* Descriptor for stdout (for reading);
  97                                    May be same number as fdin. */
  98 static int fderr;               /* Descriptor for stderr.  May be -1. */
  99 static long stdin_bytes = 0;    /* Number of bytes written to stdin. */
 100 static long stdout_bytes = 0;   /* Number of stdout bytes sent to client. */
 101 static long stderr_bytes = 0;   /* Number of stderr bytes sent to client. */
 102 static long fdout_bytes = 0;    /* Number of stdout bytes read from program. */
 103 static int stdin_eof = 0;       /* EOF message received from client. */
 104 static int fdout_eof = 0;       /* EOF encountered reading from fdout. */
 105 static int fderr_eof = 0;       /* EOF encountered readung from fderr. */
 106 static int fdin_is_tty = 0;     /* fdin points to a tty. */
 107 static int connection_in;       /* Connection to client (input). */
 108 static int connection_out;      /* Connection to client (output). */
 109 static int connection_closed = 0;       /* Connection to client closed. */
 110 static u_int buffer_high;       /* "Soft" max buffer size. */
 111 static int no_more_sessions = 0; /* Disallow further sessions. */
 112
 113 /*
 114  * This SIGCHLD kludge is used to detect when the child exits.  The server
 115  * will exit after that, as soon as forwarded connections have terminated.
 116  */
 117
 118 static volatile sig_atomic_t child_terminated = 0;      /* The child has terminated. */
 119
 120 /* Cleanup on signals (!use_privsep case only) */
 121 static volatile sig_atomic_t received_sigterm = 0;
 122
 123 /* prototypes */
 124 static void server_init_dispatch(void);
 125
 126 /*
 127  * we write to this pipe if a SIGCHLD is caught in order to avoid
 128  * the race between select() and child_terminated
 129  */
 130 static int notify_pipe[2];
 131 static void
 132 notify_setup(void)
 133 {
 134         if (pipe(notify_pipe) < 0) {
 135                 error("pipe(notify_pipe) failed %s", strerror(errno));
 136         } else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
 137             (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) {
 138                 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
 139                 close(notify_pipe[0]);
 140                 close(notify_pipe[1]);
 141         } else {
 142                 set_nonblock(notify_pipe[0]);
 143                 set_nonblock(notify_pipe[1]);
 144                 return;
 145         }
 146         notify_pipe[0] = -1;    /* read end */
 147         notify_pipe[1] = -1;    /* write end */
 148 }
 149 static void
 150 notify_parent(void)
 151 {
 152         if (notify_pipe[1] != -1)
 153                 (void)write(notify_pipe[1], "", 1);
 154 }
 155 static void
 156 notify_prepare(fd_set *readset)
 157 {
 158         if (notify_pipe[0] != -1)
 159                 FD_SET(notify_pipe[0], readset);
 160 }
 161 static void
 162 notify_done(fd_set *readset)
 163 {
 164         char c;
 165
 166         if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
 167                 while (read(notify_pipe[0], &c, 1) != -1)
 168                         debug2("notify_done: reading");
 169 }
 170
 171 /*ARGSUSED*/
 172 static void
 173 sigchld_handler(int sig)
 174 {
 175         int save_errno = errno;
 176         child_terminated = 1;
 177 #ifndef _UNICOS
 178         mysignal(SIGCHLD, sigchld_handler);
 179 #endif
 180         notify_parent();
 181         errno = save_errno;
 182 }
 183
 184 /*ARGSUSED*/
 185 static void
 186 sigterm_handler(int sig)
 187 {
 188         received_sigterm = sig;
 189 }
 190
 191 /*
 192  * Make packets from buffered stderr data, and buffer it for sending
 193  * to the client.
 194  */
 195 static void
 196 make_packets_from_stderr_data(void)
 197 {
 198         u_int len;
 199
 200         /* Send buffered stderr data to the client. */
 201         while (buffer_len(&stderr_buffer) > 0 &&
 202             packet_not_very_much_data_to_write()) {
 203                 len = buffer_len(&stderr_buffer);
 204                 if (packet_is_interactive()) {
 205                         if (len > 512)
 206                                 len = 512;
 207                 } else {
 208                         /* Keep the packets at reasonable size. */
 209                         if (len > packet_get_maxsize())
 210                                 len = packet_get_maxsize();
 211                 }
 212                 packet_start(SSH_SMSG_STDERR_DATA);
 213                 packet_put_string(buffer_ptr(&stderr_buffer), len);
 214                 packet_send();
 215                 buffer_consume(&stderr_buffer, len);
 216                 stderr_bytes += len;
 217         }
 218 }
 219
 220 /*
 221  * Make packets from buffered stdout data, and buffer it for sending to the
 222  * client.
 223  */
 224 static void
 225 make_packets_from_stdout_data(void)
 226 {
 227         u_int len;
 228
 229         /* Send buffered stdout data to the client. */
 230         while (buffer_len(&stdout_buffer) > 0 &&
 231             packet_not_very_much_data_to_write()) {
 232                 len = buffer_len(&stdout_buffer);
 233                 if (packet_is_interactive()) {
 234                         if (len > 512)
 235                                 len = 512;
 236                 } else {
 237                         /* Keep the packets at reasonable size. */
 238                         if (len > packet_get_maxsize())
 239                                 len = packet_get_maxsize();
 240                 }
 241                 packet_start(SSH_SMSG_STDOUT_DATA);
 242                 packet_put_string(buffer_ptr(&stdout_buffer), len);
 243                 packet_send();
 244                 buffer_consume(&stdout_buffer, len);
 245                 stdout_bytes += len;
 246         }
 247 }
 248
 249 static void
 250 client_alive_check(void)
 251 {
 252         int channel_id;
 253
 254         /* timeout, check to see how many we have had */
 255         if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
 256                 logit("Timeout, client not responding.");
 257                 cleanup_exit(255);
 258         }
 259
 260         /*
 261          * send a bogus global/channel request with "wantreply",
 262          * we should get back a failure
 263          */
 264         if ((channel_id = channel_find_open()) == -1) {
 265                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
 266                 packet_put_cstring("keepalive@openssh.com");
 267                 packet_put_char(1);     /* boolean: want reply */
 268         } else {
 269                 channel_request_start(channel_id, "keepalive@openssh.com", 1);
 270         }
 271         packet_send();
 272 }
 273
 274 /*
 275  * Sleep in select() until we can do something.  This will initialize the
 276  * select masks.  Upon return, the masks will indicate which descriptors
 277  * have data or can accept data.  Optionally, a maximum time can be specified
 278  * for the duration of the wait (0 = infinite).
 279  */
 280 static void
 281 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
 282     u_int *nallocp, u_int64_t max_time_milliseconds)
 283 {
 284         struct timeval tv, *tvp;
 285         int ret;
 286         time_t minwait_secs = 0;
 287         int client_alive_scheduled = 0;
 288         int program_alive_scheduled = 0;
 289
 290         /* Allocate and update select() masks for channel descriptors. */
 291         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
 292             &minwait_secs, 0);
 293
 294         if (minwait_secs != 0)
 295                 max_time_milliseconds = MIN(max_time_milliseconds,
 296                     (u_int)minwait_secs * 1000);
 297
 298         /*
 299          * if using client_alive, set the max timeout accordingly,
 300          * and indicate that this particular timeout was for client
 301          * alive by setting the client_alive_scheduled flag.
 302          *
 303          * this could be randomized somewhat to make traffic
 304          * analysis more difficult, but we're not doing it yet.
 305          */
 306         if (compat20 &&
 307             max_time_milliseconds == 0 && options.client_alive_interval) {
 308                 client_alive_scheduled = 1;
 309                 max_time_milliseconds =
 310                     (u_int64_t)options.client_alive_interval * 1000;
 311         }
 312
 313         if (compat20) {
 314 #if 0
 315                 /* wrong: bad condition XXX */
 316                 if (channel_not_very_much_buffered_data())
 317 #endif
 318                 FD_SET(connection_in, *readsetp);
 319         } else {
 320                 /*
 321                  * Read packets from the client unless we have too much
 322                  * buffered stdin or channel data.
 323                  */
 324                 if (buffer_len(&stdin_buffer) < buffer_high &&
 325                     channel_not_very_much_buffered_data())
 326                         FD_SET(connection_in, *readsetp);
 327                 /*
 328                  * If there is not too much data already buffered going to
 329                  * the client, try to get some more data from the program.
 330                  */
 331                 if (packet_not_very_much_data_to_write()) {
 332                         program_alive_scheduled = child_terminated;
 333                         if (!fdout_eof)
 334                                 FD_SET(fdout, *readsetp);
 335                         if (!fderr_eof)
 336                                 FD_SET(fderr, *readsetp);
 337                 }
 338                 /*
 339                  * If we have buffered data, try to write some of that data
 340                  * to the program.
 341                  */
 342                 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
 343                         FD_SET(fdin, *writesetp);
 344         }
 345         notify_prepare(*readsetp);
 346
 347         /*
 348          * If we have buffered packet data going to the client, mark that
 349          * descriptor.
 350          */
 351         if (packet_have_data_to_write())
 352                 FD_SET(connection_out, *writesetp);
 353
 354         /*
 355          * If child has terminated and there is enough buffer space to read
 356          * from it, then read as much as is available and exit.
 357          */
 358         if (child_terminated && packet_not_very_much_data_to_write())
 359                 if (max_time_milliseconds == 0 || client_alive_scheduled)
 360                         max_time_milliseconds = 100;
 361
 362         if (max_time_milliseconds == 0)
 363                 tvp = NULL;
 364         else {
 365                 tv.tv_sec = max_time_milliseconds / 1000;
 366                 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
 367                 tvp = &tv;
 368         }
 369
 370         /* Wait for something to happen, or the timeout to expire. */
 371         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 372
 373         if (ret == -1) {
 374                 memset(*readsetp, 0, *nallocp);
 375                 memset(*writesetp, 0, *nallocp);
 376                 if (errno != EINTR)
 377                         error("select: %.100s", strerror(errno));
 378         } else {
 379                 if (ret == 0 && client_alive_scheduled)
 380                         client_alive_check();
 381                 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
 382                         if (!fdout_eof)
 383                                 FD_SET(fdout, *readsetp);
 384                         if (!fderr_eof)
 385                                 FD_SET(fderr, *readsetp);
 386                 }
 387         }
 388
 389         notify_done(*readsetp);
 390 }
 391
 392 /*
 393  * Processes input from the client and the program.  Input data is stored
 394  * in buffers and processed later.
 395  */
 396 static void
 397 process_input(fd_set *readset)
 398 {
 399         int len;
 400         char buf[16384];
 401
 402         /* Read and buffer any input data from the client. */
 403         if (FD_ISSET(connection_in, readset)) {
 404                 int cont = 0;
 405                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 406                 if (len == 0) {
 407                         if (cont)
 408                                 return;
 409                         verbose("Connection closed by %.100s",
 410                             get_remote_ipaddr());
 411                         connection_closed = 1;
 412                         if (compat20)
 413                                 return;
 414                         cleanup_exit(255);
 415                 } else if (len < 0) {
 416                         if (errno != EINTR && errno != EAGAIN &&
 417                             errno != EWOULDBLOCK) {
 418                                 verbose("Read error from remote host "
 419                                     "%.100s: %.100s",
 420                                     get_remote_ipaddr(), strerror(errno));
 421                                 cleanup_exit(255);
 422                         }
 423                 } else {
 424                         /* Buffer any received data. */
 425                         packet_process_incoming(buf, len);
 426                 }
 427         }
 428         if (compat20)
 429                 return;
 430
 431         /* Read and buffer any available stdout data from the program. */
 432         if (!fdout_eof && FD_ISSET(fdout, readset)) {
 433                 errno = 0;
 434                 len = read(fdout, buf, sizeof(buf));
 435                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 436                     errno == EWOULDBLOCK) && !child_terminated))) {
 437                         /* do nothing */
 438 #ifndef PTY_ZEROREAD
 439                 } else if (len <= 0) {
 440 #else
 441                 } else if ((!isatty(fdout) && len <= 0) ||
 442                     (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
 443 #endif
 444                         fdout_eof = 1;
 445                 } else {
 446                         buffer_append(&stdout_buffer, buf, len);
 447                         fdout_bytes += len;
 448                 }
 449         }
 450         /* Read and buffer any available stderr data from the program. */
 451         if (!fderr_eof && FD_ISSET(fderr, readset)) {
 452                 errno = 0;
 453                 len = read(fderr, buf, sizeof(buf));
 454                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 455                     errno == EWOULDBLOCK) && !child_terminated))) {
 456                         /* do nothing */
 457 #ifndef PTY_ZEROREAD
 458                 } else if (len <= 0) {
 459 #else
 460                 } else if ((!isatty(fderr) && len <= 0) ||
 461                     (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
 462 #endif
 463                         fderr_eof = 1;
 464                 } else {
 465                         buffer_append(&stderr_buffer, buf, len);
 466                 }
 467         }
 468 }
 469
 470 /*
 471  * Sends data from internal buffers to client program stdin.
 472  */
 473 static void
 474 process_output(fd_set *writeset)
 475 {
 476         struct termios tio;
 477         u_char *data;
 478         u_int dlen;
 479         int len;
 480
 481         /* Write buffered data to program stdin. */
 482         if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
 483                 data = buffer_ptr(&stdin_buffer);
 484                 dlen = buffer_len(&stdin_buffer);
 485                 len = write(fdin, data, dlen);
 486                 if (len < 0 &&
 487                     (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
 488                         /* do nothing */
 489                 } else if (len <= 0) {
 490                         if (fdin != fdout)
 491                                 close(fdin);
 492                         else
 493                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 494                         fdin = -1;
 495                 } else {
 496                         /* Successful write. */
 497                         if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
 498                             tcgetattr(fdin, &tio) == 0 &&
 499                             !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
 500                                 /*
 501                                  * Simulate echo to reduce the impact of
 502                                  * traffic analysis
 503                                  */
 504                                 packet_send_ignore(len);
 505                                 packet_send();
 506                         }
 507                         /* Consume the data from the buffer. */
 508                         buffer_consume(&stdin_buffer, len);
 509                         /* Update the count of bytes written to the program. */
 510                         stdin_bytes += len;
 511                 }
 512         }
 513         /* Send any buffered packet data to the client. */
 514         if (FD_ISSET(connection_out, writeset))
 515                 packet_write_poll();
 516 }
 517
 518 /*
 519  * Wait until all buffered output has been sent to the client.
 520  * This is used when the program terminates.
 521  */
 522 static void
 523 drain_output(void)
 524 {
 525         /* Send any buffered stdout data to the client. */
 526         if (buffer_len(&stdout_buffer) > 0) {
 527                 packet_start(SSH_SMSG_STDOUT_DATA);
 528                 packet_put_string(buffer_ptr(&stdout_buffer),
 529                                   buffer_len(&stdout_buffer));
 530                 packet_send();
 531                 /* Update the count of sent bytes. */
 532                 stdout_bytes += buffer_len(&stdout_buffer);
 533         }
 534         /* Send any buffered stderr data to the client. */
 535         if (buffer_len(&stderr_buffer) > 0) {
 536                 packet_start(SSH_SMSG_STDERR_DATA);
 537                 packet_put_string(buffer_ptr(&stderr_buffer),
 538                                   buffer_len(&stderr_buffer));
 539                 packet_send();
 540                 /* Update the count of sent bytes. */
 541                 stderr_bytes += buffer_len(&stderr_buffer);
 542         }
 543         /* Wait until all buffered data has been written to the client. */
 544         packet_write_wait();
 545 }
 546
 547 static void
 548 process_buffered_input_packets(void)
 549 {
 550         dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
 551 }
 552
 553 /*
 554  * Performs the interactive session.  This handles data transmission between
 555  * the client and the program.  Note that the notion of stdin, stdout, and
 556  * stderr in this function is sort of reversed: this function writes to
 557  * stdin (of the child program), and reads from stdout and stderr (of the
 558  * child program).
 559  */
 560 void
 561 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 562 {
 563         fd_set *readset = NULL, *writeset = NULL;
 564         int max_fd = 0;
 565         u_int nalloc = 0;
 566         int wait_status;        /* Status returned by wait(). */
 567         pid_t wait_pid;         /* pid returned by wait(). */
 568         int waiting_termination = 0;    /* Have displayed waiting close message. */
 569         u_int64_t max_time_milliseconds;
 570         u_int previous_stdout_buffer_bytes;
 571         u_int stdout_buffer_bytes;
 572         int type;
 573
 574         debug("Entering interactive session.");
 575
 576         /* Initialize the SIGCHLD kludge. */
 577         child_terminated = 0;
 578         mysignal(SIGCHLD, sigchld_handler);
 579
 580         if (!use_privsep) {
 581                 signal(SIGTERM, sigterm_handler);
 582                 signal(SIGINT, sigterm_handler);
 583                 signal(SIGQUIT, sigterm_handler);
 584         }
 585
 586         /* Initialize our global variables. */
 587         fdin = fdin_arg;
 588         fdout = fdout_arg;
 589         fderr = fderr_arg;
 590
 591         /* nonblocking IO */
 592         set_nonblock(fdin);
 593         set_nonblock(fdout);
 594         /* we don't have stderr for interactive terminal sessions, see below */
 595         if (fderr != -1)
 596                 set_nonblock(fderr);
 597
 598         if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
 599                 fdin_is_tty = 1;
 600
 601         connection_in = packet_get_connection_in();
 602         connection_out = packet_get_connection_out();
 603
 604         notify_setup();
 605
 606         previous_stdout_buffer_bytes = 0;
 607
 608         /* Set approximate I/O buffer size. */
 609         if (packet_is_interactive())
 610                 buffer_high = 4096;
 611         else
 612                 buffer_high = 64 * 1024;
 613
 614 #if 0
 615         /* Initialize max_fd to the maximum of the known file descriptors. */
 616         max_fd = MAX(connection_in, connection_out);
 617         max_fd = MAX(max_fd, fdin);
 618         max_fd = MAX(max_fd, fdout);
 619         if (fderr != -1)
 620                 max_fd = MAX(max_fd, fderr);
 621 #endif
 622
 623         /* Initialize Initialize buffers. */
 624         buffer_init(&stdin_buffer);
 625         buffer_init(&stdout_buffer);
 626         buffer_init(&stderr_buffer);
 627
 628         /*
 629          * If we have no separate fderr (which is the case when we have a pty
 630          * - there we cannot make difference between data sent to stdout and
 631          * stderr), indicate that we have seen an EOF from stderr.  This way
 632          * we don't need to check the descriptor everywhere.
 633          */
 634         if (fderr == -1)
 635                 fderr_eof = 1;
 636
 637         server_init_dispatch();
 638
 639         /* Main loop of the server for the interactive session mode. */
 640         for (;;) {
 641
 642                 /* Process buffered packets from the client. */
 643                 process_buffered_input_packets();
 644
 645                 /*
 646                  * If we have received eof, and there is no more pending
 647                  * input data, cause a real eof by closing fdin.
 648                  */
 649                 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
 650                         if (fdin != fdout)
 651                                 close(fdin);
 652                         else
 653                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 654                         fdin = -1;
 655                 }
 656                 /* Make packets from buffered stderr data to send to the client. */
 657                 make_packets_from_stderr_data();
 658
 659                 /*
 660                  * Make packets from buffered stdout data to send to the
 661                  * client. If there is very little to send, this arranges to
 662                  * not send them now, but to wait a short while to see if we
 663                  * are getting more data. This is necessary, as some systems
 664                  * wake up readers from a pty after each separate character.
 665                  */
 666                 max_time_milliseconds = 0;
 667                 stdout_buffer_bytes = buffer_len(&stdout_buffer);
 668                 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
 669                     stdout_buffer_bytes != previous_stdout_buffer_bytes) {
 670                         /* try again after a while */
 671                         max_time_milliseconds = 10;
 672                 } else {
 673                         /* Send it now. */
 674                         make_packets_from_stdout_data();
 675                 }
 676                 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
 677
 678                 /* Send channel data to the client. */
 679                 if (packet_not_very_much_data_to_write())
 680                         channel_output_poll();
 681
 682                 /*
 683                  * Bail out of the loop if the program has closed its output
 684                  * descriptors, and we have no more data to send to the
 685                  * client, and there is no pending buffered data.
 686                  */
 687                 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
 688                     buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
 689                         if (!channel_still_open())
 690                                 break;
 691                         if (!waiting_termination) {
 692                                 const char *s = "Waiting for forwarded connections to terminate...\r\n";
 693                                 char *cp;
 694                                 waiting_termination = 1;
 695                                 buffer_append(&stderr_buffer, s, strlen(s));
 696
 697                                 /* Display list of open channels. */
 698                                 cp = channel_open_message();
 699                                 buffer_append(&stderr_buffer, cp, strlen(cp));
 700                                 free(cp);
 701                         }
 702                 }
 703                 max_fd = MAX(connection_in, connection_out);
 704                 max_fd = MAX(max_fd, fdin);
 705                 max_fd = MAX(max_fd, fdout);
 706                 max_fd = MAX(max_fd, fderr);
 707                 max_fd = MAX(max_fd, notify_pipe[0]);
 708
 709                 /* Sleep in select() until we can do something. */
 710                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 711                     &nalloc, max_time_milliseconds);
 712
 713                 if (received_sigterm) {
 714                         logit("Exiting on signal %d", (int)received_sigterm);
 715                         /* Clean up sessions, utmp, etc. */
 716                         cleanup_exit(255);
 717                 }
 718
 719                 /* Process any channel events. */
 720                 channel_after_select(readset, writeset);
 721
 722                 /* Process input from the client and from program stdout/stderr. */
 723                 process_input(readset);
 724
 725                 /* Process output to the client and to program stdin. */
 726                 process_output(writeset);
 727         }
 728         free(readset);
 729         free(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;
 830         u_int nalloc = 0;
 831         u_int64_t rekey_timeout_ms = 0;
 832
 833         debug("Entering interactive session for SSH2.");
 834
 835         mysignal(SIGCHLD, sigchld_handler);
 836         child_terminated = 0;
 837         connection_in = packet_get_connection_in();
 838         connection_out = packet_get_connection_out();
 839
 840         if (!use_privsep) {
 841                 signal(SIGTERM, sigterm_handler);
 842                 signal(SIGINT, sigterm_handler);
 843                 signal(SIGQUIT, sigterm_handler);
 844         }
 845
 846         notify_setup();
 847
 848         max_fd = MAX(connection_in, connection_out);
 849         max_fd = MAX(max_fd, notify_pipe[0]);
 850
 851         server_init_dispatch();
 852
 853         for (;;) {
 854                 process_buffered_input_packets();
 855
 856                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 857
 858                 if (!rekeying && packet_not_very_much_data_to_write())
 859                         channel_output_poll();
 860                 if (options.rekey_interval > 0 && compat20 && !rekeying)
 861                         rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
 862                 else
 863                         rekey_timeout_ms = 0;
 864
 865                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 866                     &nalloc, rekey_timeout_ms);
 867
 868                 if (received_sigterm) {
 869                         logit("Exiting on signal %d", (int)received_sigterm);
 870                         /* Clean up sessions, utmp, etc. */
 871                         cleanup_exit(255);
 872                 }
 873
 874                 collect_children();
 875                 if (!rekeying) {
 876                         channel_after_select(readset, writeset);
 877                         if (packet_need_rekeying()) {
 878                                 debug("need rekeying");
 879                                 xxx_kex->done = 0;
 880                                 kex_send_kexinit(xxx_kex);
 881                         }
 882                 }
 883                 process_input(readset);
 884                 if (connection_closed)
 885                         break;
 886                 process_output(writeset);
 887         }
 888         collect_children();
 889
 890         free(readset);
 891         free(writeset);
 892
 893         /* free all channels, no more reads and writes */
 894         channel_free_all();
 895
 896         /* free remaining sessions, e.g. remove wtmp entries */
 897         session_destroy_all(NULL);
 898 }
 899
 900 static void
 901 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
 902 {
 903         debug("Got %d/%u for keepalive", type, seq);
 904         /*
 905          * reset timeout, since we got a sane answer from the client.
 906          * even if this was generated by something other than
 907          * the bogus CHANNEL_REQUEST we send for keepalives.
 908          */
 909         packet_set_alive_timeouts(0);
 910 }
 911
 912 static void
 913 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
 914 {
 915         char *data;
 916         u_int data_len;
 917
 918         /* Stdin data from the client.  Append it to the buffer. */
 919         /* Ignore any data if the client has closed stdin. */
 920         if (fdin == -1)
 921                 return;
 922         data = packet_get_string(&data_len);
 923         packet_check_eom();
 924         buffer_append(&stdin_buffer, data, data_len);
 925         explicit_bzero(data, data_len);
 926         free(data);
 927 }
 928
 929 static void
 930 server_input_eof(int type, u_int32_t seq, void *ctxt)
 931 {
 932         /*
 933          * Eof from the client.  The stdin descriptor to the
 934          * program will be closed when all buffered data has
 935          * drained.
 936          */
 937         debug("EOF received for stdin.");
 938         packet_check_eom();
 939         stdin_eof = 1;
 940 }
 941
 942 static void
 943 server_input_window_size(int type, u_int32_t seq, void *ctxt)
 944 {
 945         u_int row = packet_get_int();
 946         u_int col = packet_get_int();
 947         u_int xpixel = packet_get_int();
 948         u_int ypixel = packet_get_int();
 949
 950         debug("Window change received.");
 951         packet_check_eom();
 952         if (fdin != -1)
 953                 pty_change_window_size(fdin, row, col, xpixel, ypixel);
 954 }
 955
 956 static Channel *
 957 server_request_direct_tcpip(void)
 958 {
 959         Channel *c = NULL;
 960         char *target, *originator;
 961         u_short target_port, originator_port;
 962
 963         target = packet_get_string(NULL);
 964         target_port = packet_get_int();
 965         originator = packet_get_string(NULL);
 966         originator_port = packet_get_int();
 967         packet_check_eom();
 968
 969         debug("server_request_direct_tcpip: originator %s port %d, target %s "
 970             "port %d", originator, originator_port, target, target_port);
 971
 972         /* XXX fine grained permissions */
 973         if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
 974             !no_port_forwarding_flag) {
 975                 c = channel_connect_to(target, target_port,
 976                     "direct-tcpip", "direct-tcpip");
 977         } else {
 978                 logit("refused local port forward: "
 979                     "originator %s port %d, target %s port %d",
 980                     originator, originator_port, target, target_port);
 981         }
 982
 983         free(originator);
 984         free(target);
 985
 986         return c;
 987 }
 988
 989 static Channel *
 990 server_request_tun(void)
 991 {
 992         Channel *c = NULL;
 993         int mode, tun;
 994         int sock;
 995
 996         mode = packet_get_int();
 997         switch (mode) {
 998         case SSH_TUNMODE_POINTOPOINT:
 999         case SSH_TUNMODE_ETHERNET:
1000                 break;
1001         default:
1002                 packet_send_debug("Unsupported tunnel device mode.");
1003                 return NULL;
1004         }
1005         if ((options.permit_tun & mode) == 0) {
1006                 packet_send_debug("Server has rejected tunnel device "
1007                     "forwarding");
1008                 return NULL;
1009         }
1010
1011         tun = packet_get_int();
1012         if (forced_tun_device != -1) {
1013                 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1014                         goto done;
1015                 tun = forced_tun_device;
1016         }
1017         sock = tun_open(tun, mode);
1018         if (sock < 0)
1019                 goto done;
1020         if (options.hpn_disabled)
1021                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1022                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1023                     "tun", 1);
1024         else
1025                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1026                     options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0,
1027                     "tun", 1);
1028         c->datagram = 1;
1029 #if defined(SSH_TUN_FILTER)
1030         if (mode == SSH_TUNMODE_POINTOPOINT)
1031                 channel_register_filter(c->self, sys_tun_infilter,
1032                     sys_tun_outfilter, NULL, NULL);
1033 #endif
1034
1035  done:
1036         if (c == NULL)
1037                 packet_send_debug("Failed to open the tunnel device.");
1038         return c;
1039 }
1040
1041 static Channel *
1042 server_request_session(void)
1043 {
1044         Channel *c;
1045
1046         debug("input_session_request");
1047         packet_check_eom();
1048
1049         if (no_more_sessions) {
1050                 packet_disconnect("Possible attack: attempt to open a session "
1051                     "after additional sessions disabled");
1052         }
1053
1054         /*
1055          * A server session has no fd to read or write until a
1056          * CHANNEL_REQUEST for a shell is made, so we set the type to
1057          * SSH_CHANNEL_LARVAL.  Additionally, a callback for handling all
1058          * CHANNEL_REQUEST messages is registered.
1059          */
1060         c = channel_new("session", SSH_CHANNEL_LARVAL,
1061             -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1062             0, "server-session", 1);
1063         if (!options.hpn_disabled && options.tcp_rcv_buf_poll)
1064                 c->dynamic_window = 1;
1065         if (session_open(the_authctxt, c->self) != 1) {
1066                 debug("session open failed, free channel %d", c->self);
1067                 channel_free(c);
1068                 return NULL;
1069         }
1070         channel_register_cleanup(c->self, session_close_by_channel, 0);
1071         return c;
1072 }
1073
1074 static void
1075 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1076 {
1077         Channel *c = NULL;
1078         char *ctype;
1079         int rchan;
1080         u_int rmaxpack, rwindow, len;
1081
1082         ctype = packet_get_string(&len);
1083         rchan = packet_get_int();
1084         rwindow = packet_get_int();
1085         rmaxpack = packet_get_int();
1086
1087         debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1088             ctype, rchan, rwindow, rmaxpack);
1089
1090         if (strcmp(ctype, "session") == 0) {
1091                 c = server_request_session();
1092         } else if (strcmp(ctype, "direct-tcpip") == 0) {
1093                 c = server_request_direct_tcpip();
1094         } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1095                 c = server_request_tun();
1096         }
1097         if (c != NULL) {
1098                 debug("server_input_channel_open: confirm %s", ctype);
1099                 c->remote_id = rchan;
1100                 c->remote_window = rwindow;
1101                 c->remote_maxpacket = rmaxpack;
1102                 if (c->type != SSH_CHANNEL_CONNECTING) {
1103                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1104                         packet_put_int(c->remote_id);
1105                         packet_put_int(c->self);
1106                         packet_put_int(c->local_window);
1107                         packet_put_int(c->local_maxpacket);
1108                         packet_send();
1109                 }
1110         } else {
1111                 debug("server_input_channel_open: failure %s", ctype);
1112                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1113                 packet_put_int(rchan);
1114                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1115                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1116                         packet_put_cstring("open failed");
1117                         packet_put_cstring("");
1118                 }
1119                 packet_send();
1120         }
1121         free(ctype);
1122 }
1123
1124 static void
1125 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1126 {
1127         char *rtype;
1128         int want_reply;
1129         int success = 0, allocated_listen_port = 0;
1130
1131         rtype = packet_get_string(NULL);
1132         want_reply = packet_get_char();
1133         debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1134
1135         /* -R style forwarding */
1136         if (strcmp(rtype, "tcpip-forward") == 0) {
1137                 struct passwd *pw;
1138                 char *listen_address;
1139                 u_short listen_port;
1140
1141                 pw = the_authctxt->pw;
1142                 if (pw == NULL || !the_authctxt->valid)
1143                         fatal("server_input_global_request: no/invalid user");
1144                 listen_address = packet_get_string(NULL);
1145                 listen_port = (u_short)packet_get_int();
1146                 debug("server_input_global_request: tcpip-forward listen %s port %d",
1147                     listen_address, listen_port);
1148
1149                 /* check permissions */
1150                 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
1151                     no_port_forwarding_flag ||
1152                     (!want_reply && listen_port == 0)
1153 #ifndef NO_IPPORT_RESERVED_CONCEPT
1154                     || (listen_port != 0 && listen_port < IPPORT_RESERVED &&
1155                     pw->pw_uid != 0)
1156 #endif
1157                     ) {
1158                         success = 0;
1159                         packet_send_debug("Server has disabled port forwarding.");
1160                 } else {
1161                         /* Start listening on the port */
1162                         success = channel_setup_remote_fwd_listener(
1163                             listen_address, listen_port,
1164                             &allocated_listen_port, options.gateway_ports);
1165                 }
1166                 free(listen_address);
1167         } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1168                 char *cancel_address;
1169                 u_short cancel_port;
1170
1171                 cancel_address = packet_get_string(NULL);
1172                 cancel_port = (u_short)packet_get_int();
1173                 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1174                     cancel_address, cancel_port);
1175
1176                 success = channel_cancel_rport_listener(cancel_address,
1177                     cancel_port);
1178                 free(cancel_address);
1179         } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1180                 no_more_sessions = 1;
1181                 success = 1;
1182         }
1183         if (want_reply) {
1184                 packet_start(success ?
1185                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1186                 if (success && allocated_listen_port > 0)
1187                         packet_put_int(allocated_listen_port);
1188                 packet_send();
1189                 packet_write_wait();
1190         }
1191         free(rtype);
1192 }
1193
1194 static void
1195 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1196 {
1197         Channel *c;
1198         int id, reply, success = 0;
1199         char *rtype;
1200
1201         id = packet_get_int();
1202         rtype = packet_get_string(NULL);
1203         reply = packet_get_char();
1204
1205         debug("server_input_channel_req: channel %d request %s reply %d",
1206             id, rtype, reply);
1207
1208         if ((c = channel_lookup(id)) == NULL)
1209                 packet_disconnect("server_input_channel_req: "
1210                     "unknown channel %d", id);
1211         if (!strcmp(rtype, "eow@openssh.com")) {
1212                 packet_check_eom();
1213                 chan_rcvd_eow(c);
1214         } else if ((c->type == SSH_CHANNEL_LARVAL ||
1215             c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1216                 success = session_input_channel_req(c, rtype);
1217         if (reply) {
1218                 packet_start(success ?
1219                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1220                 packet_put_int(c->remote_id);
1221                 packet_send();
1222         }
1223         free(rtype);
1224 }
1225
1226 static void
1227 server_init_dispatch_20(void)
1228 {
1229         debug("server_init_dispatch_20");
1230         dispatch_init(&dispatch_protocol_error);
1231         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1232         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1233         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1234         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1235         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1236         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1237         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1238         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1239         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1240         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1241         /* client_alive */
1242         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1243         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1244         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1245         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1246         /* rekeying */
1247         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1248 }
1249 static void
1250 server_init_dispatch_13(void)
1251 {
1252         debug("server_init_dispatch_13");
1253         dispatch_init(NULL);
1254         dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1255         dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1256         dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1257         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1258         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1259         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1260         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1261         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1262         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1263 }
1264 static void
1265 server_init_dispatch_15(void)
1266 {
1267         server_init_dispatch_13();
1268         debug("server_init_dispatch_15");
1269         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1270         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1271 }
1272 static void
1273 server_init_dispatch(void)
1274 {
1275         if (compat20)
1276                 server_init_dispatch_20();
1277         else if (compat13)
1278                 server_init_dispatch_13();
1279         else
1280                 server_init_dispatch_15();
1281 }