crypto/openssh/serverloop.c

   1 /* $OpenBSD: serverloop.c,v 1.159 2009/05/28 16:50:16 andreas Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Server main loop for handling the interactive session.
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  *
  14  * SSH2 support by Markus Friedl.
  15  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "includes.h"
  39
  40 #include <sys/types.h>
  41 #include <sys/param.h>
  42 #include <sys/wait.h>
  43 #include <sys/socket.h>
  44 #ifdef HAVE_SYS_TIME_H
  45 # include <sys/time.h>
  46 #endif
  47
  48 #include <netinet/in.h>
  49
  50 #include <errno.h>
  51 #include <fcntl.h>
  52 #include <pwd.h>
  53 #include <signal.h>
  54 #include <string.h>
  55 #include <termios.h>
  56 #include <unistd.h>
  57 #include <stdarg.h>
  58
  59 #include "openbsd-compat/sys-queue.h"
  60 #include "xmalloc.h"
  61 #include "packet.h"
  62 #include "buffer.h"
  63 #include "log.h"
  64 #include "servconf.h"
  65 #include "canohost.h"
  66 #include "sshpty.h"
  67 #include "channels.h"
  68 #include "compat.h"
  69 #include "ssh1.h"
  70 #include "ssh2.h"
  71 #include "key.h"
  72 #include "cipher.h"
  73 #include "kex.h"
  74 #include "hostfile.h"
  75 #include "auth.h"
  76 #include "session.h"
  77 #include "dispatch.h"
  78 #include "auth-options.h"
  79 #include "serverloop.h"
  80 #include "misc.h"
  81 #include "roaming.h"
  82
  83 extern ServerOptions options;
  84
  85 /* XXX */
  86 extern Kex *xxx_kex;
  87 extern Authctxt *the_authctxt;
  88 extern int use_privsep;
  89
  90 static Buffer stdin_buffer;     /* Buffer for stdin data. */
  91 static Buffer stdout_buffer;    /* Buffer for stdout data. */
  92 static Buffer stderr_buffer;    /* Buffer for stderr data. */
  93 static int fdin;                /* Descriptor for stdin (for writing) */
  94 static int fdout;               /* Descriptor for stdout (for reading);
  95                                    May be same number as fdin. */
  96 static int fderr;               /* Descriptor for stderr.  May be -1. */
  97 static u_long stdin_bytes = 0;  /* Number of bytes written to stdin. */
  98 static u_long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
  99 static u_long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
 100 static u_long fdout_bytes = 0;  /* Number of stdout bytes read from program. */
 101 static int stdin_eof = 0;       /* EOF message received from client. */
 102 static int fdout_eof = 0;       /* EOF encountered reading from fdout. */
 103 static int fderr_eof = 0;       /* EOF encountered readung from fderr. */
 104 static int fdin_is_tty = 0;     /* fdin points to a tty. */
 105 static int connection_in;       /* Connection to client (input). */
 106 static int connection_out;      /* Connection to client (output). */
 107 static int connection_closed = 0;       /* Connection to client closed. */
 108 static u_int buffer_high;       /* "Soft" max buffer size. */
 109 static int no_more_sessions = 0; /* Disallow further sessions. */
 110
 111 /*
 112  * This SIGCHLD kludge is used to detect when the child exits.  The server
 113  * will exit after that, as soon as forwarded connections have terminated.
 114  */
 115
 116 static volatile sig_atomic_t child_terminated = 0;      /* The child has terminated. */
 117
 118 /* Cleanup on signals (!use_privsep case only) */
 119 static volatile sig_atomic_t received_sigterm = 0;
 120
 121 /* prototypes */
 122 static void server_init_dispatch(void);
 123
 124 /*
 125  * Returns current time in seconds from Jan 1, 1970 with the maximum
 126  * available resolution.
 127  */
 128
 129 static double
 130 get_current_time(void)
 131 {
 132         struct timeval tv;
 133         gettimeofday(&tv, NULL);
 134         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 135 }
 136
 137
 138 /*
 139  * we write to this pipe if a SIGCHLD is caught in order to avoid
 140  * the race between select() and child_terminated
 141  */
 142 static int notify_pipe[2];
 143 static void
 144 notify_setup(void)
 145 {
 146         if (pipe(notify_pipe) < 0) {
 147                 error("pipe(notify_pipe) failed %s", strerror(errno));
 148         } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
 149             (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
 150                 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
 151                 close(notify_pipe[0]);
 152                 close(notify_pipe[1]);
 153         } else {
 154                 set_nonblock(notify_pipe[0]);
 155                 set_nonblock(notify_pipe[1]);
 156                 return;
 157         }
 158         notify_pipe[0] = -1;    /* read end */
 159         notify_pipe[1] = -1;    /* write end */
 160 }
 161 static void
 162 notify_parent(void)
 163 {
 164         if (notify_pipe[1] != -1)
 165                 write(notify_pipe[1], "", 1);
 166 }
 167 static void
 168 notify_prepare(fd_set *readset)
 169 {
 170         if (notify_pipe[0] != -1)
 171                 FD_SET(notify_pipe[0], readset);
 172 }
 173 static void
 174 notify_done(fd_set *readset)
 175 {
 176         char c;
 177
 178         if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
 179                 while (read(notify_pipe[0], &c, 1) != -1)
 180                         debug2("notify_done: reading");
 181 }
 182
 183 /*ARGSUSED*/
 184 static void
 185 sigchld_handler(int sig)
 186 {
 187         int save_errno = errno;
 188         child_terminated = 1;
 189 #ifndef _UNICOS
 190         mysignal(SIGCHLD, sigchld_handler);
 191 #endif
 192         notify_parent();
 193         errno = save_errno;
 194 }
 195
 196 /*ARGSUSED*/
 197 static void
 198 sigterm_handler(int sig)
 199 {
 200         received_sigterm = sig;
 201 }
 202
 203 /*
 204  * Make packets from buffered stderr data, and buffer it for sending
 205  * to the client.
 206  */
 207 static void
 208 make_packets_from_stderr_data(void)
 209 {
 210         u_int len;
 211
 212         /* Send buffered stderr data to the client. */
 213         while (buffer_len(&stderr_buffer) > 0 &&
 214             packet_not_very_much_data_to_write()) {
 215                 len = buffer_len(&stderr_buffer);
 216                 if (packet_is_interactive()) {
 217                         if (len > 512)
 218                                 len = 512;
 219                 } else {
 220                         /* Keep the packets at reasonable size. */
 221                         if (len > packet_get_maxsize())
 222                                 len = packet_get_maxsize();
 223                 }
 224                 packet_start(SSH_SMSG_STDERR_DATA);
 225                 packet_put_string(buffer_ptr(&stderr_buffer), len);
 226                 packet_send();
 227                 buffer_consume(&stderr_buffer, len);
 228                 stderr_bytes += len;
 229         }
 230 }
 231
 232 /*
 233  * Make packets from buffered stdout data, and buffer it for sending to the
 234  * client.
 235  */
 236 static void
 237 make_packets_from_stdout_data(void)
 238 {
 239         u_int len;
 240
 241         /* Send buffered stdout data to the client. */
 242         while (buffer_len(&stdout_buffer) > 0 &&
 243             packet_not_very_much_data_to_write()) {
 244                 len = buffer_len(&stdout_buffer);
 245                 if (packet_is_interactive()) {
 246                         if (len > 512)
 247                                 len = 512;
 248                 } else {
 249                         /* Keep the packets at reasonable size. */
 250                         if (len > packet_get_maxsize())
 251                                 len = packet_get_maxsize();
 252                 }
 253                 packet_start(SSH_SMSG_STDOUT_DATA);
 254                 packet_put_string(buffer_ptr(&stdout_buffer), len);
 255                 packet_send();
 256                 buffer_consume(&stdout_buffer, len);
 257                 stdout_bytes += len;
 258         }
 259 }
 260
 261 static void
 262 client_alive_check(void)
 263 {
 264         int channel_id;
 265
 266         /* timeout, check to see how many we have had */
 267         if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
 268                 logit("Timeout, client not responding.");
 269                 cleanup_exit(255);
 270         }
 271
 272         /*
 273          * send a bogus global/channel request with "wantreply",
 274          * we should get back a failure
 275          */
 276         if ((channel_id = channel_find_open()) == -1) {
 277                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
 278                 packet_put_cstring("keepalive@openssh.com");
 279                 packet_put_char(1);     /* boolean: want reply */
 280         } else {
 281                 channel_request_start(channel_id, "keepalive@openssh.com", 1);
 282         }
 283         packet_send();
 284 }
 285
 286 /*
 287  * Sleep in select() until we can do something.  This will initialize the
 288  * select masks.  Upon return, the masks will indicate which descriptors
 289  * have data or can accept data.  Optionally, a maximum time can be specified
 290  * for the duration of the wait (0 = infinite).
 291  */
 292 static void
 293 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
 294     u_int *nallocp, u_int max_time_milliseconds)
 295 {
 296         struct timeval tv, *tvp;
 297         int ret;
 298         int client_alive_scheduled = 0;
 299         int program_alive_scheduled = 0;
 300
 301         /*
 302          * if using client_alive, set the max timeout accordingly,
 303          * and indicate that this particular timeout was for client
 304          * alive by setting the client_alive_scheduled flag.
 305          *
 306          * this could be randomized somewhat to make traffic
 307          * analysis more difficult, but we're not doing it yet.
 308          */
 309         if (compat20 &&
 310             max_time_milliseconds == 0 && options.client_alive_interval) {
 311                 client_alive_scheduled = 1;
 312                 max_time_milliseconds = options.client_alive_interval * 1000;
 313         }
 314
 315         /* Allocate and update select() masks for channel descriptors. */
 316         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
 317
 318         if (compat20) {
 319 #if 0
 320                 /* wrong: bad condition XXX */
 321                 if (channel_not_very_much_buffered_data())
 322 #endif
 323                 FD_SET(connection_in, *readsetp);
 324         } else {
 325                 /*
 326                  * Read packets from the client unless we have too much
 327                  * buffered stdin or channel data.
 328                  */
 329                 if (buffer_len(&stdin_buffer) < buffer_high &&
 330                     channel_not_very_much_buffered_data())
 331                         FD_SET(connection_in, *readsetp);
 332                 /*
 333                  * If there is not too much data already buffered going to
 334                  * the client, try to get some more data from the program.
 335                  */
 336                 if (packet_not_very_much_data_to_write()) {
 337                         program_alive_scheduled = child_terminated;
 338                         if (!fdout_eof)
 339                                 FD_SET(fdout, *readsetp);
 340                         if (!fderr_eof)
 341                                 FD_SET(fderr, *readsetp);
 342                 }
 343                 /*
 344                  * If we have buffered data, try to write some of that data
 345                  * to the program.
 346                  */
 347                 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
 348                         FD_SET(fdin, *writesetp);
 349         }
 350         notify_prepare(*readsetp);
 351
 352         /*
 353          * If we have buffered packet data going to the client, mark that
 354          * descriptor.
 355          */
 356         if (packet_have_data_to_write())
 357                 FD_SET(connection_out, *writesetp);
 358
 359         /*
 360          * If child has terminated and there is enough buffer space to read
 361          * from it, then read as much as is available and exit.
 362          */
 363         if (child_terminated && packet_not_very_much_data_to_write())
 364                 if (max_time_milliseconds == 0 || client_alive_scheduled)
 365                         max_time_milliseconds = 100;
 366
 367         if (max_time_milliseconds == 0)
 368                 tvp = NULL;
 369         else {
 370                 tv.tv_sec = max_time_milliseconds / 1000;
 371                 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
 372                 tvp = &tv;
 373         }
 374
 375         /* Wait for something to happen, or the timeout to expire. */
 376         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 377
 378         if (ret == -1) {
 379                 memset(*readsetp, 0, *nallocp);
 380                 memset(*writesetp, 0, *nallocp);
 381                 if (errno != EINTR)
 382                         error("select: %.100s", strerror(errno));
 383         } else {
 384                 if (ret == 0 && client_alive_scheduled)
 385                         client_alive_check();
 386                 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
 387                         if (!fdout_eof)
 388                                 FD_SET(fdout, *readsetp);
 389                         if (!fderr_eof)
 390                                 FD_SET(fderr, *readsetp);
 391                 }
 392         }
 393
 394         notify_done(*readsetp);
 395 }
 396
 397 /*
 398  * Processes input from the client and the program.  Input data is stored
 399  * in buffers and processed later.
 400  */
 401 static void
 402 process_input(fd_set *readset)
 403 {
 404         int len;
 405         char buf[16384];
 406
 407         /* Read and buffer any input data from the client. */
 408         if (FD_ISSET(connection_in, readset)) {
 409                 int cont = 0;
 410                 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
 411                 if (len == 0) {
 412                         if (cont)
 413                                 return;
 414                         verbose("Connection closed by %.100s",
 415                             get_remote_ipaddr());
 416                         connection_closed = 1;
 417                         if (compat20)
 418                                 return;
 419                         cleanup_exit(255);
 420                 } else if (len < 0) {
 421                         if (errno != EINTR && errno != EAGAIN &&
 422                             errno != EWOULDBLOCK) {
 423                                 verbose("Read error from remote host "
 424                                     "%.100s: %.100s",
 425                                     get_remote_ipaddr(), strerror(errno));
 426                                 cleanup_exit(255);
 427                         }
 428                 } else {
 429                         /* Buffer any received data. */
 430                         packet_process_incoming(buf, len);
 431                         fdout_bytes += len;
 432                 }
 433         }
 434         if (compat20)
 435                 return;
 436
 437         /* Read and buffer any available stdout data from the program. */
 438         if (!fdout_eof && FD_ISSET(fdout, readset)) {
 439                 errno = 0;
 440                 len = read(fdout, buf, sizeof(buf));
 441                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 442                     errno == EWOULDBLOCK) && !child_terminated))) {
 443                         /* do nothing */
 444 #ifndef PTY_ZEROREAD
 445                 } else if (len <= 0) {
 446 #else
 447                 } else if ((!isatty(fdout) && len <= 0) ||
 448                     (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
 449 #endif
 450                         fdout_eof = 1;
 451                 } else {
 452                         buffer_append(&stdout_buffer, buf, len);
 453                         fdout_bytes += len;
 454                         debug ("FD out now: %ld", fdout_bytes);
 455                 }
 456         }
 457         /* Read and buffer any available stderr data from the program. */
 458         if (!fderr_eof && FD_ISSET(fderr, readset)) {
 459                 errno = 0;
 460                 len = read(fderr, buf, sizeof(buf));
 461                 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
 462                     errno == EWOULDBLOCK) && !child_terminated))) {
 463                         /* do nothing */
 464 #ifndef PTY_ZEROREAD
 465                 } else if (len <= 0) {
 466 #else
 467                 } else if ((!isatty(fderr) && len <= 0) ||
 468                     (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
 469 #endif
 470                         fderr_eof = 1;
 471                 } else {
 472                         buffer_append(&stderr_buffer, buf, len);
 473                 }
 474         }
 475 }
 476
 477 /*
 478  * Sends data from internal buffers to client program stdin.
 479  */
 480 static void
 481 process_output(fd_set *writeset)
 482 {
 483         struct termios tio;
 484         u_char *data;
 485         u_int dlen;
 486         int len;
 487
 488         /* Write buffered data to program stdin. */
 489         if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
 490                 data = buffer_ptr(&stdin_buffer);
 491                 dlen = buffer_len(&stdin_buffer);
 492                 len = write(fdin, data, dlen);
 493                 if (len < 0 &&
 494                     (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
 495                         /* do nothing */
 496                 } else if (len <= 0) {
 497                         if (fdin != fdout)
 498                                 close(fdin);
 499                         else
 500                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 501                         fdin = -1;
 502                 } else {
 503                         /* Successful write. */
 504                         if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
 505                             tcgetattr(fdin, &tio) == 0 &&
 506                             !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
 507                                 /*
 508                                  * Simulate echo to reduce the impact of
 509                                  * traffic analysis
 510                                  */
 511                                 packet_send_ignore(len);
 512                                 packet_send();
 513                         }
 514                         /* Consume the data from the buffer. */
 515                         buffer_consume(&stdin_buffer, len);
 516                         /* Update the count of bytes written to the program. */
 517                         stdin_bytes += len;
 518                 }
 519         }
 520         /* Send any buffered packet data to the client. */
 521         if (FD_ISSET(connection_out, writeset))
 522                 stdin_bytes += packet_write_poll();
 523 }
 524
 525 /*
 526  * Wait until all buffered output has been sent to the client.
 527  * This is used when the program terminates.
 528  */
 529 static void
 530 drain_output(void)
 531 {
 532         /* Send any buffered stdout data to the client. */
 533         if (buffer_len(&stdout_buffer) > 0) {
 534                 packet_start(SSH_SMSG_STDOUT_DATA);
 535                 packet_put_string(buffer_ptr(&stdout_buffer),
 536                                   buffer_len(&stdout_buffer));
 537                 packet_send();
 538                 /* Update the count of sent bytes. */
 539                 stdout_bytes += buffer_len(&stdout_buffer);
 540         }
 541         /* Send any buffered stderr data to the client. */
 542         if (buffer_len(&stderr_buffer) > 0) {
 543                 packet_start(SSH_SMSG_STDERR_DATA);
 544                 packet_put_string(buffer_ptr(&stderr_buffer),
 545                                   buffer_len(&stderr_buffer));
 546                 packet_send();
 547                 /* Update the count of sent bytes. */
 548                 stderr_bytes += buffer_len(&stderr_buffer);
 549         }
 550         /* Wait until all buffered data has been written to the client. */
 551         packet_write_wait();
 552 }
 553
 554 static void
 555 process_buffered_input_packets(void)
 556 {
 557         dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
 558 }
 559
 560 /*
 561  * Performs the interactive session.  This handles data transmission between
 562  * the client and the program.  Note that the notion of stdin, stdout, and
 563  * stderr in this function is sort of reversed: this function writes to
 564  * stdin (of the child program), and reads from stdout and stderr (of the
 565  * child program).
 566  */
 567 void
 568 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 569 {
 570         fd_set *readset = NULL, *writeset = NULL;
 571         int max_fd = 0;
 572         u_int nalloc = 0;
 573         int wait_status;        /* Status returned by wait(). */
 574         pid_t wait_pid;         /* pid returned by wait(). */
 575         int waiting_termination = 0;    /* Have displayed waiting close message. */
 576         u_int max_time_milliseconds;
 577         u_int previous_stdout_buffer_bytes;
 578         u_int stdout_buffer_bytes;
 579         int type;
 580
 581         debug("Entering interactive session.");
 582
 583         /* Initialize the SIGCHLD kludge. */
 584         child_terminated = 0;
 585         mysignal(SIGCHLD, sigchld_handler);
 586
 587         if (!use_privsep) {
 588                 signal(SIGTERM, sigterm_handler);
 589                 signal(SIGINT, sigterm_handler);
 590                 signal(SIGQUIT, sigterm_handler);
 591         }
 592
 593         /* Initialize our global variables. */
 594         fdin = fdin_arg;
 595         fdout = fdout_arg;
 596         fderr = fderr_arg;
 597
 598         /* nonblocking IO */
 599         set_nonblock(fdin);
 600         set_nonblock(fdout);
 601         /* we don't have stderr for interactive terminal sessions, see below */
 602         if (fderr != -1)
 603                 set_nonblock(fderr);
 604
 605         if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
 606                 fdin_is_tty = 1;
 607
 608         connection_in = packet_get_connection_in();
 609         connection_out = packet_get_connection_out();
 610
 611         notify_setup();
 612
 613         previous_stdout_buffer_bytes = 0;
 614
 615         /* Set approximate I/O buffer size. */
 616         if (packet_is_interactive())
 617                 buffer_high = 4096;
 618         else
 619                 buffer_high = 64 * 1024;
 620
 621 #if 0
 622         /* Initialize max_fd to the maximum of the known file descriptors. */
 623         max_fd = MAX(connection_in, connection_out);
 624         max_fd = MAX(max_fd, fdin);
 625         max_fd = MAX(max_fd, fdout);
 626         if (fderr != -1)
 627                 max_fd = MAX(max_fd, fderr);
 628 #endif
 629
 630         /* Initialize Initialize buffers. */
 631         buffer_init(&stdin_buffer);
 632         buffer_init(&stdout_buffer);
 633         buffer_init(&stderr_buffer);
 634
 635         /*
 636          * If we have no separate fderr (which is the case when we have a pty
 637          * - there we cannot make difference between data sent to stdout and
 638          * stderr), indicate that we have seen an EOF from stderr.  This way
 639          * we don't need to check the descriptor everywhere.
 640          */
 641         if (fderr == -1)
 642                 fderr_eof = 1;
 643
 644         server_init_dispatch();
 645
 646         /* Main loop of the server for the interactive session mode. */
 647         for (;;) {
 648
 649                 /* Process buffered packets from the client. */
 650                 process_buffered_input_packets();
 651
 652                 /*
 653                  * If we have received eof, and there is no more pending
 654                  * input data, cause a real eof by closing fdin.
 655                  */
 656                 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
 657                         if (fdin != fdout)
 658                                 close(fdin);
 659                         else
 660                                 shutdown(fdin, SHUT_WR); /* We will no longer send. */
 661                         fdin = -1;
 662                 }
 663                 /* Make packets from buffered stderr data to send to the client. */
 664                 make_packets_from_stderr_data();
 665
 666                 /*
 667                  * Make packets from buffered stdout data to send to the
 668                  * client. If there is very little to send, this arranges to
 669                  * not send them now, but to wait a short while to see if we
 670                  * are getting more data. This is necessary, as some systems
 671                  * wake up readers from a pty after each separate character.
 672                  */
 673                 max_time_milliseconds = 0;
 674                 stdout_buffer_bytes = buffer_len(&stdout_buffer);
 675                 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
 676                     stdout_buffer_bytes != previous_stdout_buffer_bytes) {
 677                         /* try again after a while */
 678                         max_time_milliseconds = 10;
 679                 } else {
 680                         /* Send it now. */
 681                         make_packets_from_stdout_data();
 682                 }
 683                 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
 684
 685                 /* Send channel data to the client. */
 686                 if (packet_not_very_much_data_to_write())
 687                         channel_output_poll();
 688
 689                 /*
 690                  * Bail out of the loop if the program has closed its output
 691                  * descriptors, and we have no more data to send to the
 692                  * client, and there is no pending buffered data.
 693                  */
 694                 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
 695                     buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
 696                         if (!channel_still_open())
 697                                 break;
 698                         if (!waiting_termination) {
 699                                 const char *s = "Waiting for forwarded connections to terminate...\r\n";
 700                                 char *cp;
 701                                 waiting_termination = 1;
 702                                 buffer_append(&stderr_buffer, s, strlen(s));
 703
 704                                 /* Display list of open channels. */
 705                                 cp = channel_open_message();
 706                                 buffer_append(&stderr_buffer, cp, strlen(cp));
 707                                 xfree(cp);
 708                         }
 709                 }
 710                 max_fd = MAX(connection_in, connection_out);
 711                 max_fd = MAX(max_fd, fdin);
 712                 max_fd = MAX(max_fd, fdout);
 713                 max_fd = MAX(max_fd, fderr);
 714                 max_fd = MAX(max_fd, notify_pipe[0]);
 715
 716                 /* Sleep in select() until we can do something. */
 717                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 718                     &nalloc, max_time_milliseconds);
 719
 720                 if (received_sigterm) {
 721                         logit("Exiting on signal %d", received_sigterm);
 722                         /* Clean up sessions, utmp, etc. */
 723                         cleanup_exit(255);
 724                 }
 725
 726                 /* Process any channel events. */
 727                 channel_after_select(readset, writeset);
 728
 729                 /* Process input from the client and from program stdout/stderr. */
 730                 process_input(readset);
 731
 732                 /* Process output to the client and to program stdin. */
 733                 process_output(writeset);
 734         }
 735         if (readset)
 736                 xfree(readset);
 737         if (writeset)
 738                 xfree(writeset);
 739
 740         /* Cleanup and termination code. */
 741
 742         /* Wait until all output has been sent to the client. */
 743         drain_output();
 744
 745         debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
 746             stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
 747
 748         /* Free and clear the buffers. */
 749         buffer_free(&stdin_buffer);
 750         buffer_free(&stdout_buffer);
 751         buffer_free(&stderr_buffer);
 752
 753         /* Close the file descriptors. */
 754         if (fdout != -1)
 755                 close(fdout);
 756         fdout = -1;
 757         fdout_eof = 1;
 758         if (fderr != -1)
 759                 close(fderr);
 760         fderr = -1;
 761         fderr_eof = 1;
 762         if (fdin != -1)
 763                 close(fdin);
 764         fdin = -1;
 765
 766         channel_free_all();
 767
 768         /* We no longer want our SIGCHLD handler to be called. */
 769         mysignal(SIGCHLD, SIG_DFL);
 770
 771         while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
 772                 if (errno != EINTR)
 773                         packet_disconnect("wait: %.100s", strerror(errno));
 774         if (wait_pid != pid)
 775                 error("Strange, wait returned pid %ld, expected %ld",
 776                     (long)wait_pid, (long)pid);
 777
 778         /* Check if it exited normally. */
 779         if (WIFEXITED(wait_status)) {
 780                 /* Yes, normal exit.  Get exit status and send it to the client. */
 781                 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
 782                 packet_start(SSH_SMSG_EXITSTATUS);
 783                 packet_put_int(WEXITSTATUS(wait_status));
 784                 packet_send();
 785                 packet_write_wait();
 786
 787                 /*
 788                  * Wait for exit confirmation.  Note that there might be
 789                  * other packets coming before it; however, the program has
 790                  * already died so we just ignore them.  The client is
 791                  * supposed to respond with the confirmation when it receives
 792                  * the exit status.
 793                  */
 794                 do {
 795                         type = packet_read();
 796                 }
 797                 while (type != SSH_CMSG_EXIT_CONFIRMATION);
 798
 799                 debug("Received exit confirmation.");
 800                 return;
 801         }
 802         /* Check if the program terminated due to a signal. */
 803         if (WIFSIGNALED(wait_status))
 804                 packet_disconnect("Command terminated on signal %d.",
 805                                   WTERMSIG(wait_status));
 806
 807         /* Some weird exit cause.  Just exit. */
 808         packet_disconnect("wait returned status %04x.", wait_status);
 809         /* NOTREACHED */
 810 }
 811
 812 static void
 813 collect_children(void)
 814 {
 815         pid_t pid;
 816         sigset_t oset, nset;
 817         int status;
 818
 819         /* block SIGCHLD while we check for dead children */
 820         sigemptyset(&nset);
 821         sigaddset(&nset, SIGCHLD);
 822         sigprocmask(SIG_BLOCK, &nset, &oset);
 823         if (child_terminated) {
 824                 debug("Received SIGCHLD.");
 825                 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
 826                     (pid < 0 && errno == EINTR))
 827                         if (pid > 0)
 828                                 session_close_by_pid(pid, status);
 829                 child_terminated = 0;
 830         }
 831         sigprocmask(SIG_SETMASK, &oset, NULL);
 832 }
 833
 834 void
 835 server_loop2(Authctxt *authctxt)
 836 {
 837         fd_set *readset = NULL, *writeset = NULL;
 838         int rekeying = 0, max_fd, nalloc = 0;
 839         double start_time, total_time;
 840
 841         debug("Entering interactive session for SSH2.");
 842         start_time = get_current_time();
 843
 844         mysignal(SIGCHLD, sigchld_handler);
 845         child_terminated = 0;
 846         connection_in = packet_get_connection_in();
 847         connection_out = packet_get_connection_out();
 848
 849         if (!use_privsep) {
 850                 signal(SIGTERM, sigterm_handler);
 851                 signal(SIGINT, sigterm_handler);
 852                 signal(SIGQUIT, sigterm_handler);
 853         }
 854
 855         notify_setup();
 856
 857         max_fd = MAX(connection_in, connection_out);
 858         max_fd = MAX(max_fd, notify_pipe[0]);
 859
 860         server_init_dispatch();
 861
 862         for (;;) {
 863                 process_buffered_input_packets();
 864
 865                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
 866
 867                 if (!rekeying && packet_not_very_much_data_to_write())
 868                         channel_output_poll();
 869                 wait_until_can_do_something(&readset, &writeset, &max_fd,
 870                     &nalloc, 0);
 871
 872                 if (received_sigterm) {
 873                         logit("Exiting on signal %d", received_sigterm);
 874                         /* Clean up sessions, utmp, etc. */
 875                         cleanup_exit(255);
 876                 }
 877
 878                 collect_children();
 879                 if (!rekeying) {
 880                         channel_after_select(readset, writeset);
 881                         if (packet_need_rekeying()) {
 882                                 debug("need rekeying");
 883                                 xxx_kex->done = 0;
 884                                 kex_send_kexinit(xxx_kex);
 885                         }
 886                 }
 887                 process_input(readset);
 888                 if (connection_closed)
 889                         break;
 890                 process_output(writeset);
 891         }
 892         collect_children();
 893
 894         if (readset)
 895                 xfree(readset);
 896         if (writeset)
 897                 xfree(writeset);
 898
 899         /* free all channels, no more reads and writes */
 900         channel_free_all();
 901
 902         /* free remaining sessions, e.g. remove wtmp entries */
 903         session_destroy_all(NULL);
 904         total_time = get_current_time() - start_time;
 905         logit("SSH: Server;LType: Throughput;Remote: %s-%d;IN: %lu;OUT: %lu;Duration: %.1f;tPut_in: %.1f;tPut_out: %.1f",
 906               get_remote_ipaddr(), get_remote_port(),
 907               stdin_bytes, fdout_bytes, total_time, stdin_bytes / total_time,
 908               fdout_bytes / total_time);
 909 }
 910
 911 static void
 912 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
 913 {
 914         debug("Got %d/%u for keepalive", type, seq);
 915         /*
 916          * reset timeout, since we got a sane answer from the client.
 917          * even if this was generated by something other than
 918          * the bogus CHANNEL_REQUEST we send for keepalives.
 919          */
 920         packet_set_alive_timeouts(0);
 921 }
 922
 923 static void
 924 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
 925 {
 926         char *data;
 927         u_int data_len;
 928
 929         /* Stdin data from the client.  Append it to the buffer. */
 930         /* Ignore any data if the client has closed stdin. */
 931         if (fdin == -1)
 932                 return;
 933         data = packet_get_string(&data_len);
 934         packet_check_eom();
 935         buffer_append(&stdin_buffer, data, data_len);
 936         memset(data, 0, data_len);
 937         xfree(data);
 938 }
 939
 940 static void
 941 server_input_eof(int type, u_int32_t seq, void *ctxt)
 942 {
 943         /*
 944          * Eof from the client.  The stdin descriptor to the
 945          * program will be closed when all buffered data has
 946          * drained.
 947          */
 948         debug("EOF received for stdin.");
 949         packet_check_eom();
 950         stdin_eof = 1;
 951 }
 952
 953 static void
 954 server_input_window_size(int type, u_int32_t seq, void *ctxt)
 955 {
 956         u_int row = packet_get_int();
 957         u_int col = packet_get_int();
 958         u_int xpixel = packet_get_int();
 959         u_int ypixel = packet_get_int();
 960
 961         debug("Window change received.");
 962         packet_check_eom();
 963         if (fdin != -1)
 964                 pty_change_window_size(fdin, row, col, xpixel, ypixel);
 965 }
 966
 967 static Channel *
 968 server_request_direct_tcpip(void)
 969 {
 970         Channel *c;
 971         char *target, *originator;
 972         u_short target_port, originator_port;
 973
 974         target = packet_get_string(NULL);
 975         target_port = packet_get_int();
 976         originator = packet_get_string(NULL);
 977         originator_port = packet_get_int();
 978         packet_check_eom();
 979
 980         debug("server_request_direct_tcpip: originator %s port %d, target %s "
 981             "port %d", originator, originator_port, target, target_port);
 982
 983         /* XXX check permission */
 984         c = channel_connect_to(target, target_port,
 985             "direct-tcpip", "direct-tcpip");
 986
 987         xfree(originator);
 988         xfree(target);
 989
 990         return c;
 991 }
 992
 993 static Channel *
 994 server_request_tun(void)
 995 {
 996         Channel *c = NULL;
 997         int mode, tun;
 998         int sock;
 999
1000         mode = packet_get_int();
1001         switch (mode) {
1002         case SSH_TUNMODE_POINTOPOINT:
1003         case SSH_TUNMODE_ETHERNET:
1004                 break;
1005         default:
1006                 packet_send_debug("Unsupported tunnel device mode.");
1007                 return NULL;
1008         }
1009         if ((options.permit_tun & mode) == 0) {
1010                 packet_send_debug("Server has rejected tunnel device "
1011                     "forwarding");
1012                 return NULL;
1013         }
1014
1015         tun = packet_get_int();
1016         if (forced_tun_device != -1) {
1017                 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1018                         goto done;
1019                 tun = forced_tun_device;
1020         }
1021         sock = tun_open(tun, mode);
1022         if (sock < 0)
1023                 goto done;
1024         if (options.hpn_disabled)
1025         c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1026             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1027         else
1028                 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1029                     options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1030         c->datagram = 1;
1031 #if defined(SSH_TUN_FILTER)
1032         if (mode == SSH_TUNMODE_POINTOPOINT)
1033                 channel_register_filter(c->self, sys_tun_infilter,
1034                     sys_tun_outfilter, NULL, NULL);
1035 #endif
1036
1037  done:
1038         if (c == NULL)
1039                 packet_send_debug("Failed to open the tunnel device.");
1040         return c;
1041 }
1042
1043 static Channel *
1044 server_request_session(void)
1045 {
1046         Channel *c;
1047
1048         debug("input_session_request");
1049         packet_check_eom();
1050
1051         if (no_more_sessions) {
1052                 packet_disconnect("Possible attack: attempt to open a session "
1053                     "after additional sessions disabled");
1054         }
1055
1056         /*
1057          * A server session has no fd to read or write until a
1058          * CHANNEL_REQUEST for a shell is made, so we set the type to
1059          * SSH_CHANNEL_LARVAL.  Additionally, a callback for handling all
1060          * CHANNEL_REQUEST messages is registered.
1061          */
1062         c = channel_new("session", SSH_CHANNEL_LARVAL,
1063             -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1064             0, "server-session", 1);
1065         if ((options.tcp_rcv_buf_poll) && (!options.hpn_disabled))
1066                 c->dynamic_window = 1;
1067         if (session_open(the_authctxt, c->self) != 1) {
1068                 debug("session open failed, free channel %d", c->self);
1069                 channel_free(c);
1070                 return NULL;
1071         }
1072         channel_register_cleanup(c->self, session_close_by_channel, 0);
1073         return c;
1074 }
1075
1076 static void
1077 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1078 {
1079         Channel *c = NULL;
1080         char *ctype;
1081         int rchan;
1082         u_int rmaxpack, rwindow, len;
1083
1084         ctype = packet_get_string(&len);
1085         rchan = packet_get_int();
1086         rwindow = packet_get_int();
1087         rmaxpack = packet_get_int();
1088
1089         debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1090             ctype, rchan, rwindow, rmaxpack);
1091
1092         if (strcmp(ctype, "session") == 0) {
1093                 c = server_request_session();
1094         } else if (strcmp(ctype, "direct-tcpip") == 0) {
1095                 c = server_request_direct_tcpip();
1096         } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1097                 c = server_request_tun();
1098         }
1099         if (c != NULL) {
1100                 debug("server_input_channel_open: confirm %s", ctype);
1101                 c->remote_id = rchan;
1102                 c->remote_window = rwindow;
1103                 c->remote_maxpacket = rmaxpack;
1104                 if (c->type != SSH_CHANNEL_CONNECTING) {
1105                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1106                         packet_put_int(c->remote_id);
1107                         packet_put_int(c->self);
1108                         packet_put_int(c->local_window);
1109                         packet_put_int(c->local_maxpacket);
1110                         packet_send();
1111                 }
1112         } else {
1113                 debug("server_input_channel_open: failure %s", ctype);
1114                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1115                 packet_put_int(rchan);
1116                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1117                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1118                         packet_put_cstring("open failed");
1119                         packet_put_cstring("");
1120                 }
1121                 packet_send();
1122         }
1123         xfree(ctype);
1124 }
1125
1126 static void
1127 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1128 {
1129         char *rtype;
1130         int want_reply;
1131         int success = 0, allocated_listen_port = 0;
1132
1133         rtype = packet_get_string(NULL);
1134         want_reply = packet_get_char();
1135         debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1136
1137         /* -R style forwarding */
1138         if (strcmp(rtype, "tcpip-forward") == 0) {
1139                 struct passwd *pw;
1140                 char *listen_address;
1141                 u_short listen_port;
1142
1143                 pw = the_authctxt->pw;
1144                 if (pw == NULL || !the_authctxt->valid)
1145                         fatal("server_input_global_request: no/invalid user");
1146                 listen_address = packet_get_string(NULL);
1147                 listen_port = (u_short)packet_get_int();
1148                 debug("server_input_global_request: tcpip-forward listen %s port %d",
1149                     listen_address, listen_port);
1150
1151                 /* check permissions */
1152                 if (!options.allow_tcp_forwarding ||
1153                     no_port_forwarding_flag ||
1154                     (!want_reply && listen_port == 0)
1155 #ifndef NO_IPPORT_RESERVED_CONCEPT
1156                     || (listen_port != 0 && listen_port < IPPORT_RESERVED &&
1157                     pw->pw_uid != 0)
1158 #endif
1159                     ) {
1160                         success = 0;
1161                         packet_send_debug("Server has disabled port forwarding.");
1162                 } else {
1163                         /* Start listening on the port */
1164                         success = channel_setup_remote_fwd_listener(
1165                             listen_address, listen_port,
1166                             &allocated_listen_port, options.gateway_ports);
1167                 }
1168                 xfree(listen_address);
1169         } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1170                 char *cancel_address;
1171                 u_short cancel_port;
1172
1173                 cancel_address = packet_get_string(NULL);
1174                 cancel_port = (u_short)packet_get_int();
1175                 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1176                     cancel_address, cancel_port);
1177
1178                 success = channel_cancel_rport_listener(cancel_address,
1179                     cancel_port);
1180                 xfree(cancel_address);
1181         } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1182                 no_more_sessions = 1;
1183                 success = 1;
1184         }
1185         if (want_reply) {
1186                 packet_start(success ?
1187                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1188                 if (success && allocated_listen_port > 0)
1189                         packet_put_int(allocated_listen_port);
1190                 packet_send();
1191                 packet_write_wait();
1192         }
1193         xfree(rtype);
1194 }
1195
1196 static void
1197 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1198 {
1199         Channel *c;
1200         int id, reply, success = 0;
1201         char *rtype;
1202
1203         id = packet_get_int();
1204         rtype = packet_get_string(NULL);
1205         reply = packet_get_char();
1206
1207         debug("server_input_channel_req: channel %d request %s reply %d",
1208             id, rtype, reply);
1209
1210         if ((c = channel_lookup(id)) == NULL)
1211                 packet_disconnect("server_input_channel_req: "
1212                     "unknown channel %d", id);
1213         if (!strcmp(rtype, "eow@openssh.com")) {
1214                 packet_check_eom();
1215                 chan_rcvd_eow(c);
1216         } else if ((c->type == SSH_CHANNEL_LARVAL ||
1217             c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1218                 success = session_input_channel_req(c, rtype);
1219         if (reply) {
1220                 packet_start(success ?
1221                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1222                 packet_put_int(c->remote_id);
1223                 packet_send();
1224         }
1225         xfree(rtype);
1226 }
1227
1228 static void
1229 server_init_dispatch_20(void)
1230 {
1231         debug("server_init_dispatch_20");
1232         dispatch_init(&dispatch_protocol_error);
1233         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1234         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1235         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1236         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1237         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1238         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1239         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1240         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1241         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1242         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1243         /* client_alive */
1244         dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1245         dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1246         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1247         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1248         /* rekeying */
1249         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1250 }
1251 static void
1252 server_init_dispatch_13(void)
1253 {
1254         debug("server_init_dispatch_13");
1255         dispatch_init(NULL);
1256         dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1257         dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1258         dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1259         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1260         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1261         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1262         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1263         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1264         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1265 }
1266 static void
1267 server_init_dispatch_15(void)
1268 {
1269         server_init_dispatch_13();
1270         debug("server_init_dispatch_15");
1271         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1272         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1273 }
1274 static void
1275 server_init_dispatch(void)
1276 {
1277         if (compat20)
1278                 server_init_dispatch_20();
1279         else if (compat13)
1280                 server_init_dispatch_13();
1281         else
1282                 server_init_dispatch_15();
1283 }