openssh/clientloop.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * The main loop for the interactive session (client side).
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  *
  13  *
  14  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  *
  37  * SSH2 support added by Markus Friedl.
  38  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  59  */
  60
  61 #include "includes.h"
  62 RCSID("$OpenBSD: clientloop.c,v 1.149 2005/12/30 15:56:37 reyk Exp $");
  63
  64 #include "ssh.h"
  65 #include "ssh1.h"
  66 #include "ssh2.h"
  67 #include "xmalloc.h"
  68 #include "packet.h"
  69 #include "buffer.h"
  70 #include "compat.h"
  71 #include "channels.h"
  72 #include "dispatch.h"
  73 #include "buffer.h"
  74 #include "bufaux.h"
  75 #include "key.h"
  76 #include "kex.h"
  77 #include "log.h"
  78 #include "readconf.h"
  79 #include "clientloop.h"
  80 #include "sshconnect.h"
  81 #include "authfd.h"
  82 #include "atomicio.h"
  83 #include "sshpty.h"
  84 #include "misc.h"
  85 #include "monitor_fdpass.h"
  86 #include "match.h"
  87 #include "msg.h"
  88
  89 /* import options */
  90 extern Options options;
  91
  92 /* Flag indicating that stdin should be redirected from /dev/null. */
  93 extern int stdin_null_flag;
  94
  95 /* Flag indicating that no shell has been requested */
  96 extern int no_shell_flag;
  97
  98 /* Control socket */
  99 extern int control_fd;
 100
 101 /*
 102  * Name of the host we are connecting to.  This is the name given on the
 103  * command line, or the HostName specified for the user-supplied name in a
 104  * configuration file.
 105  */
 106 extern char *host;
 107
 108 /*
 109  * Flag to indicate that we have received a window change signal which has
 110  * not yet been processed.  This will cause a message indicating the new
 111  * window size to be sent to the server a little later.  This is volatile
 112  * because this is updated in a signal handler.
 113  */
 114 static volatile sig_atomic_t received_window_change_signal = 0;
 115 static volatile sig_atomic_t received_signal = 0;
 116
 117 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 118 static int in_non_blocking_mode = 0;
 119
 120 /* Common data for the client loop code. */
 121 static int quit_pending;        /* Set to non-zero to quit the client loop. */
 122 static int escape_char;         /* Escape character. */
 123 static int escape_pending;      /* Last character was the escape character */
 124 static int last_was_cr;         /* Last character was a newline. */
 125 static int exit_status;         /* Used to store the exit status of the command. */
 126 static int stdin_eof;           /* EOF has been encountered on standard error. */
 127 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 128 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 129 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 130 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 131 static u_int buffer_high;/* Soft max buffer size. */
 132 static int connection_in;       /* Connection to server (input). */
 133 static int connection_out;      /* Connection to server (output). */
 134 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 135 static int session_closed = 0;  /* In SSH2: login session closed. */
 136 static int server_alive_timeouts = 0;
 137
 138 static void client_init_dispatch(void);
 139 int     session_ident = -1;
 140
 141 struct confirm_ctx {
 142         int want_tty;
 143         int want_subsys;
 144         int want_x_fwd;
 145         int want_agent_fwd;
 146         Buffer cmd;
 147         char *term;
 148         struct termios tio;
 149         char **env;
 150 };
 151
 152 /*XXX*/
 153 extern Kex *xxx_kex;
 154
 155 void ssh_process_session2_setup(int, int, int, Buffer *);
 156
 157 /* Restores stdin to blocking mode. */
 158
 159 static void
 160 leave_non_blocking(void)
 161 {
 162         if (in_non_blocking_mode) {
 163                 unset_nonblock(fileno(stdin));
 164                 in_non_blocking_mode = 0;
 165         }
 166 }
 167
 168 /* Puts stdin terminal in non-blocking mode. */
 169
 170 static void
 171 enter_non_blocking(void)
 172 {
 173         in_non_blocking_mode = 1;
 174         set_nonblock(fileno(stdin));
 175 }
 176
 177 /*
 178  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 179  * flag indicating that the window has changed.
 180  */
 181
 182 static void
 183 window_change_handler(int sig)
 184 {
 185         received_window_change_signal = 1;
 186         signal(SIGWINCH, window_change_handler);
 187 }
 188
 189 /*
 190  * Signal handler for signals that cause the program to terminate.  These
 191  * signals must be trapped to restore terminal modes.
 192  */
 193
 194 static void
 195 signal_handler(int sig)
 196 {
 197         received_signal = sig;
 198         quit_pending = 1;
 199 }
 200
 201 /*
 202  * Returns current time in seconds from Jan 1, 1970 with the maximum
 203  * available resolution.
 204  */
 205
 206 static double
 207 get_current_time(void)
 208 {
 209         struct timeval tv;
 210         gettimeofday(&tv, NULL);
 211         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 212 }
 213
 214 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 215 void
 216 client_x11_get_proto(const char *display, const char *xauth_path,
 217     u_int trusted, char **_proto, char **_data)
 218 {
 219         char cmd[1024];
 220         char line[512];
 221         char xdisplay[512];
 222         static char proto[512], data[512];
 223         FILE *f;
 224         int got_data = 0, generated = 0, do_unlink = 0, i;
 225         char *xauthdir, *xauthfile;
 226         struct stat st;
 227
 228         xauthdir = xauthfile = NULL;
 229         *_proto = proto;
 230         *_data = data;
 231         proto[0] = data[0] = '\0';
 232
 233         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 234                 debug("No xauth program.");
 235         } else {
 236                 if (display == NULL) {
 237                         debug("x11_get_proto: DISPLAY not set");
 238                         return;
 239                 }
 240                 /*
 241                  * Handle FamilyLocal case where $DISPLAY does
 242                  * not match an authorization entry.  For this we
 243                  * just try "xauth list unix:displaynum.screennum".
 244                  * XXX: "localhost" match to determine FamilyLocal
 245                  *      is not perfect.
 246                  */
 247                 if (strncmp(display, "localhost:", 10) == 0) {
 248                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 249                             display + 10);
 250                         display = xdisplay;
 251                 }
 252                 if (trusted == 0) {
 253                         xauthdir = xmalloc(MAXPATHLEN);
 254                         xauthfile = xmalloc(MAXPATHLEN);
 255                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 256                         if (mkdtemp(xauthdir) != NULL) {
 257                                 do_unlink = 1;
 258                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 259                                     xauthdir);
 260                                 snprintf(cmd, sizeof(cmd),
 261                                     "%s -f %s generate %s " SSH_X11_PROTO
 262                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 263                                     xauth_path, xauthfile, display);
 264                                 debug2("x11_get_proto: %s", cmd);
 265                                 if (system(cmd) == 0)
 266                                         generated = 1;
 267                         }
 268                 }
 269                 snprintf(cmd, sizeof(cmd),
 270                     "%s %s%s list %s 2>" _PATH_DEVNULL,
 271                     xauth_path,
 272                     generated ? "-f " : "" ,
 273                     generated ? xauthfile : "",
 274                     display);
 275                 debug2("x11_get_proto: %s", cmd);
 276                 f = popen(cmd, "r");
 277                 if (f && fgets(line, sizeof(line), f) &&
 278                     sscanf(line, "%*s %511s %511s", proto, data) == 2)
 279                         got_data = 1;
 280                 if (f)
 281                         pclose(f);
 282         }
 283
 284         if (do_unlink) {
 285                 unlink(xauthfile);
 286                 rmdir(xauthdir);
 287         }
 288         if (xauthdir)
 289                 xfree(xauthdir);
 290         if (xauthfile)
 291                 xfree(xauthfile);
 292
 293         /*
 294          * If we didn't get authentication data, just make up some
 295          * data.  The forwarding code will check the validity of the
 296          * response anyway, and substitute this data.  The X11
 297          * server, however, will ignore this fake data and use
 298          * whatever authentication mechanisms it was using otherwise
 299          * for the local connection.
 300          */
 301         if (!got_data) {
 302                 u_int32_t rnd = 0;
 303
 304                 logit("Warning: No xauth data; "
 305                     "using fake authentication data for X11 forwarding.");
 306                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 307                 for (i = 0; i < 16; i++) {
 308                         if (i % 4 == 0)
 309                                 rnd = arc4random();
 310                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 311                             rnd & 0xff);
 312                         rnd >>= 8;
 313                 }
 314         }
 315 }
 316
 317 /*
 318  * This is called when the interactive is entered.  This checks if there is
 319  * an EOF coming on stdin.  We must check this explicitly, as select() does
 320  * not appear to wake up when redirecting from /dev/null.
 321  */
 322
 323 static void
 324 client_check_initial_eof_on_stdin(void)
 325 {
 326         int len;
 327         char buf[1];
 328
 329         /*
 330          * If standard input is to be "redirected from /dev/null", we simply
 331          * mark that we have seen an EOF and send an EOF message to the
 332          * server. Otherwise, we try to read a single character; it appears
 333          * that for some files, such /dev/null, select() never wakes up for
 334          * read for this descriptor, which means that we never get EOF.  This
 335          * way we will get the EOF if stdin comes from /dev/null or similar.
 336          */
 337         if (stdin_null_flag) {
 338                 /* Fake EOF on stdin. */
 339                 debug("Sending eof.");
 340                 stdin_eof = 1;
 341                 packet_start(SSH_CMSG_EOF);
 342                 packet_send();
 343         } else {
 344                 enter_non_blocking();
 345
 346                 /* Check for immediate EOF on stdin. */
 347                 len = read(fileno(stdin), buf, 1);
 348                 if (len == 0) {
 349                         /* EOF.  Record that we have seen it and send EOF to server. */
 350                         debug("Sending eof.");
 351                         stdin_eof = 1;
 352                         packet_start(SSH_CMSG_EOF);
 353                         packet_send();
 354                 } else if (len > 0) {
 355                         /*
 356                          * Got data.  We must store the data in the buffer,
 357                          * and also process it as an escape character if
 358                          * appropriate.
 359                          */
 360                         if ((u_char) buf[0] == escape_char)
 361                                 escape_pending = 1;
 362                         else
 363                                 buffer_append(&stdin_buffer, buf, 1);
 364                 }
 365                 leave_non_blocking();
 366         }
 367 }
 368
 369
 370 /*
 371  * Make packets from buffered stdin data, and buffer them for sending to the
 372  * connection.
 373  */
 374
 375 static void
 376 client_make_packets_from_stdin_data(void)
 377 {
 378         u_int len;
 379
 380         /* Send buffered stdin data to the server. */
 381         while (buffer_len(&stdin_buffer) > 0 &&
 382             packet_not_very_much_data_to_write()) {
 383                 len = buffer_len(&stdin_buffer);
 384                 /* Keep the packets at reasonable size. */
 385                 if (len > packet_get_maxsize())
 386                         len = packet_get_maxsize();
 387                 packet_start(SSH_CMSG_STDIN_DATA);
 388                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 389                 packet_send();
 390                 buffer_consume(&stdin_buffer, len);
 391                 stdin_bytes += len;
 392                 /* If we have a pending EOF, send it now. */
 393                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 394                         packet_start(SSH_CMSG_EOF);
 395                         packet_send();
 396                 }
 397         }
 398 }
 399
 400 /*
 401  * Checks if the client window has changed, and sends a packet about it to
 402  * the server if so.  The actual change is detected elsewhere (by a software
 403  * interrupt on Unix); this just checks the flag and sends a message if
 404  * appropriate.
 405  */
 406
 407 static void
 408 client_check_window_change(void)
 409 {
 410         struct winsize ws;
 411
 412         if (! received_window_change_signal)
 413                 return;
 414         /** XXX race */
 415         received_window_change_signal = 0;
 416
 417         debug2("client_check_window_change: changed");
 418
 419         if (compat20) {
 420                 channel_send_window_changes();
 421         } else {
 422                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 423                         return;
 424                 packet_start(SSH_CMSG_WINDOW_SIZE);
 425                 packet_put_int(ws.ws_row);
 426                 packet_put_int(ws.ws_col);
 427                 packet_put_int(ws.ws_xpixel);
 428                 packet_put_int(ws.ws_ypixel);
 429                 packet_send();
 430         }
 431 }
 432
 433 static void
 434 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 435 {
 436         server_alive_timeouts = 0;
 437         client_global_request_reply_fwd(type, seq, ctxt);
 438 }
 439
 440 static void
 441 server_alive_check(void)
 442 {
 443         if (++server_alive_timeouts > options.server_alive_count_max)
 444                 packet_disconnect("Timeout, server not responding.");
 445         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 446         packet_put_cstring("keepalive@openssh.com");
 447         packet_put_char(1);     /* boolean: want reply */
 448         packet_send();
 449 }
 450
 451 /*
 452  * Waits until the client can do something (some data becomes available on
 453  * one of the file descriptors).
 454  */
 455 static void
 456 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 457     int *maxfdp, u_int *nallocp, int rekeying)
 458 {
 459         struct timeval tv, *tvp;
 460         int ret;
 461
 462         /* Add any selections by the channel mechanism. */
 463         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 464
 465         if (!compat20) {
 466                 /* Read from the connection, unless our buffers are full. */
 467                 if (buffer_len(&stdout_buffer) < buffer_high &&
 468                     buffer_len(&stderr_buffer) < buffer_high &&
 469                     channel_not_very_much_buffered_data())
 470                         FD_SET(connection_in, *readsetp);
 471                 /*
 472                  * Read from stdin, unless we have seen EOF or have very much
 473                  * buffered data to send to the server.
 474                  */
 475                 if (!stdin_eof && packet_not_very_much_data_to_write())
 476                         FD_SET(fileno(stdin), *readsetp);
 477
 478                 /* Select stdout/stderr if have data in buffer. */
 479                 if (buffer_len(&stdout_buffer) > 0)
 480                         FD_SET(fileno(stdout), *writesetp);
 481                 if (buffer_len(&stderr_buffer) > 0)
 482                         FD_SET(fileno(stderr), *writesetp);
 483         } else {
 484                 /* channel_prepare_select could have closed the last channel */
 485                 if (session_closed && !channel_still_open() &&
 486                     !packet_have_data_to_write()) {
 487                         /* clear mask since we did not call select() */
 488                         memset(*readsetp, 0, *nallocp);
 489                         memset(*writesetp, 0, *nallocp);
 490                         return;
 491                 } else {
 492                         FD_SET(connection_in, *readsetp);
 493                 }
 494         }
 495
 496         /* Select server connection if have data to write to the server. */
 497         if (packet_have_data_to_write())
 498                 FD_SET(connection_out, *writesetp);
 499
 500         if (control_fd != -1)
 501                 FD_SET(control_fd, *readsetp);
 502
 503         /*
 504          * Wait for something to happen.  This will suspend the process until
 505          * some selected descriptor can be read, written, or has some other
 506          * event pending.
 507          */
 508
 509         if (options.server_alive_interval == 0 || !compat20)
 510                 tvp = NULL;
 511         else {
 512                 tv.tv_sec = options.server_alive_interval;
 513                 tv.tv_usec = 0;
 514                 tvp = &tv;
 515         }
 516         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 517         if (ret < 0) {
 518                 char buf[100];
 519
 520                 /*
 521                  * We have to clear the select masks, because we return.
 522                  * We have to return, because the mainloop checks for the flags
 523                  * set by the signal handlers.
 524                  */
 525                 memset(*readsetp, 0, *nallocp);
 526                 memset(*writesetp, 0, *nallocp);
 527
 528                 if (errno == EINTR)
 529                         return;
 530                 /* Note: we might still have data in the buffers. */
 531                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 532                 buffer_append(&stderr_buffer, buf, strlen(buf));
 533                 quit_pending = 1;
 534         } else if (ret == 0)
 535                 server_alive_check();
 536 }
 537
 538 static void
 539 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 540 {
 541         /* Flush stdout and stderr buffers. */
 542         if (buffer_len(bout) > 0)
 543                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 544         if (buffer_len(berr) > 0)
 545                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 546
 547         leave_raw_mode();
 548
 549         /*
 550          * Free (and clear) the buffer to reduce the amount of data that gets
 551          * written to swap.
 552          */
 553         buffer_free(bin);
 554         buffer_free(bout);
 555         buffer_free(berr);
 556
 557         /* Send the suspend signal to the program itself. */
 558         kill(getpid(), SIGTSTP);
 559
 560         /* Reset window sizes in case they have changed */
 561         received_window_change_signal = 1;
 562
 563         /* OK, we have been continued by the user. Reinitialize buffers. */
 564         buffer_init(bin);
 565         buffer_init(bout);
 566         buffer_init(berr);
 567
 568         enter_raw_mode();
 569 }
 570
 571 static void
 572 client_process_net_input(fd_set * readset)
 573 {
 574         int len;
 575         char buf[8192];
 576
 577         /*
 578          * Read input from the server, and add any such data to the buffer of
 579          * the packet subsystem.
 580          */
 581         if (FD_ISSET(connection_in, readset)) {
 582                 /* Read as much as possible. */
 583                 len = read(connection_in, buf, sizeof(buf));
 584                 if (len == 0) {
 585                         /* Received EOF.  The remote host has closed the connection. */
 586                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 587                                  host);
 588                         buffer_append(&stderr_buffer, buf, strlen(buf));
 589                         quit_pending = 1;
 590                         return;
 591                 }
 592                 /*
 593                  * There is a kernel bug on Solaris that causes select to
 594                  * sometimes wake up even though there is no data available.
 595                  */
 596                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 597                         len = 0;
 598
 599                 if (len < 0) {
 600                         /* An error has encountered.  Perhaps there is a network problem. */
 601                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 602                                  host, strerror(errno));
 603                         buffer_append(&stderr_buffer, buf, strlen(buf));
 604                         quit_pending = 1;
 605                         return;
 606                 }
 607                 packet_process_incoming(buf, len);
 608         }
 609 }
 610
 611 static void
 612 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 613 {
 614         int id;
 615         Channel *c;
 616
 617         id = packet_get_int();
 618         packet_check_eom();
 619
 620         if ((c = channel_lookup(id)) == NULL) {
 621                 error("%s: no channel for id %d", __func__, id);
 622                 return;
 623         }
 624
 625         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 626                 debug2("Request suceeded on channel %d", id);
 627         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 628                 error("Request failed on channel %d", id);
 629                 channel_free(c);
 630         }
 631 }
 632
 633 static void
 634 client_extra_session2_setup(int id, void *arg)
 635 {
 636         struct confirm_ctx *cctx = arg;
 637         const char *display;
 638         Channel *c;
 639         int i;
 640
 641         if (cctx == NULL)
 642                 fatal("%s: cctx == NULL", __func__);
 643         if ((c = channel_lookup(id)) == NULL)
 644                 fatal("%s: no channel for id %d", __func__, id);
 645
 646         display = getenv("DISPLAY");
 647         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 648                 char *proto, *data;
 649                 /* Get reasonable local authentication information. */
 650                 client_x11_get_proto(display, options.xauth_location,
 651                     options.forward_x11_trusted, &proto, &data);
 652                 /* Request forwarding with authentication spoofing. */
 653                 debug("Requesting X11 forwarding with authentication spoofing.");
 654                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 655                 /* XXX wait for reply */
 656         }
 657
 658         if (cctx->want_agent_fwd && options.forward_agent) {
 659                 debug("Requesting authentication agent forwarding.");
 660                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 661                 packet_send();
 662         }
 663
 664         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 665             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 666             client_subsystem_reply);
 667
 668         c->confirm_ctx = NULL;
 669         buffer_free(&cctx->cmd);
 670         xfree(cctx->term);
 671         if (cctx->env != NULL) {
 672                 for (i = 0; cctx->env[i] != NULL; i++)
 673                         xfree(cctx->env[i]);
 674                 xfree(cctx->env);
 675         }
 676         xfree(cctx);
 677 }
 678
 679 static void
 680 client_process_control(fd_set * readset)
 681 {
 682         Buffer m;
 683         Channel *c;
 684         int client_fd, new_fd[3], ver, allowed;
 685         socklen_t addrlen;
 686         struct sockaddr_storage addr;
 687         struct confirm_ctx *cctx;
 688         char *cmd;
 689         u_int i, len, env_len, command, flags;
 690         uid_t euid;
 691         gid_t egid;
 692         int listen_port = 0;
 693         int connect_port = 0;
 694         char * listen_host = NULL;
 695         char * connect_host = NULL;
 696
 697         /*
 698          * Accept connection on control socket
 699          */
 700         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 701                 return;
 702
 703         memset(&addr, 0, sizeof(addr));
 704         addrlen = sizeof(addr);
 705         if ((client_fd = accept(control_fd,
 706             (struct sockaddr*)&addr, &addrlen)) == -1) {
 707                 error("%s accept: %s", __func__, strerror(errno));
 708                 return;
 709         }
 710
 711         if (getpeereid(client_fd, &euid, &egid) < 0) {
 712                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 713                 close(client_fd);
 714                 return;
 715         }
 716         if ((euid != 0) && (getuid() != euid)) {
 717                 error("control mode uid mismatch: peer euid %u != uid %u",
 718                     (u_int) euid, (u_int) getuid());
 719                 close(client_fd);
 720                 return;
 721         }
 722
 723         unset_nonblock(client_fd);
 724
 725         /* Read command */
 726         buffer_init(&m);
 727         if (ssh_msg_recv(client_fd, &m) == -1) {
 728                 error("%s: client msg_recv failed", __func__);
 729                 close(client_fd);
 730                 buffer_free(&m);
 731                 return;
 732         }
 733         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 734                 error("%s: wrong client version %d", __func__, ver);
 735                 buffer_free(&m);
 736                 close(client_fd);
 737                 return;
 738         }
 739
 740         allowed = 1;
 741         command = buffer_get_int(&m);
 742         flags = buffer_get_int(&m);
 743
 744         if (SSHMUX_FLAG_PORTFORWARD & flags)
 745         {
 746                 listen_host = buffer_get_string(&m,NULL);
 747                 listen_port = buffer_get_int(&m);
 748                 connect_host = buffer_get_string(&m,NULL);
 749                 connect_port = buffer_get_int(&m);
 750         }
 751         buffer_clear(&m);
 752
 753         switch (command) {
 754         case SSHMUX_COMMAND_OPEN:
 755                 if (options.control_master == SSHCTL_MASTER_ASK ||
 756                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 757                         allowed = ask_permission("Allow shared connection "
 758                             "to %s? ", host);
 759                 /* continue below */
 760                 break;
 761         case SSHMUX_COMMAND_TERMINATE:
 762                 if (options.control_master == SSHCTL_MASTER_ASK ||
 763                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 764                         allowed = ask_permission("Terminate shared connection "
 765                             "to %s? ", host);
 766                 if (allowed)
 767                         quit_pending = 1;
 768                 /* FALLTHROUGH */
 769         case SSHMUX_COMMAND_ALIVE_CHECK:
 770                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 771                 buffer_clear(&m);
 772                 buffer_put_int(&m, allowed);
 773                 buffer_put_int(&m, getpid());
 774                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 775                         error("%s: client msg_send failed", __func__);
 776                         close(client_fd);
 777                         buffer_free(&m);
 778                         return;
 779                 }
 780                 buffer_free(&m);
 781                 close(client_fd);
 782                 return;
 783         default:
 784                 error("Unsupported command %d", command);
 785                 buffer_free(&m);
 786                 close(client_fd);
 787                 return;
 788         }
 789
 790         if (allowed && (SSHMUX_FLAG_PORTFORWARD & flags) && listen_host && connect_host)
 791         {
 792                 int ret;
 793                 Forward * fwd;
 794
 795                 fwd = &options.local_forwards[options.num_local_forwards++];
 796                 fwd->listen_host = xstrdup(listen_host);
 797                 fwd->listen_port = listen_port;
 798                 fwd->connect_host = xstrdup(connect_host);
 799                 fwd->connect_port = connect_port;
 800                 ret = channel_setup_local_fwd_listener(
 801                         options.local_forwards[options.num_local_forwards-1].listen_host,
 802                         options.local_forwards[options.num_local_forwards-1].listen_port,
 803                         options.local_forwards[options.num_local_forwards-1].connect_host,
 804                         options.local_forwards[options.num_local_forwards-1].connect_port,
 805                         options.gateway_ports, options.hpn_disabled, options.hpn_buffer_size);
 806
 807         }
 808
 809
 810         if (listen_host)
 811                 xfree(listen_host);
 812         if (connect_host)
 813                 xfree(connect_host);
 814
 815         /* Reply for SSHMUX_COMMAND_OPEN */
 816         buffer_clear(&m);
 817         buffer_put_int(&m, allowed);
 818         buffer_put_int(&m, getpid());
 819         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 820                 error("%s: client msg_send failed", __func__);
 821                 close(client_fd);
 822                 buffer_free(&m);
 823                 return;
 824         }
 825
 826         if (!allowed) {
 827                 error("Refused control connection");
 828                 close(client_fd);
 829                 buffer_free(&m);
 830                 return;
 831         }
 832
 833         buffer_clear(&m);
 834         if (ssh_msg_recv(client_fd, &m) == -1) {
 835                 error("%s: client msg_recv failed", __func__);
 836                 close(client_fd);
 837                 buffer_free(&m);
 838                 return;
 839         }
 840         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 841                 error("%s: wrong client version %d", __func__, ver);
 842                 buffer_free(&m);
 843                 close(client_fd);
 844                 return;
 845         }
 846
 847         cctx = xmalloc(sizeof(*cctx));
 848         memset(cctx, 0, sizeof(*cctx));
 849         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 850         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 851         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 852         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 853         cctx->term = buffer_get_string(&m, &len);
 854
 855         cmd = buffer_get_string(&m, &len);
 856         buffer_init(&cctx->cmd);
 857         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 858
 859         env_len = buffer_get_int(&m);
 860         env_len = MIN(env_len, 4096);
 861         debug3("%s: receiving %d env vars", __func__, env_len);
 862         if (env_len != 0) {
 863                 cctx->env = xmalloc(sizeof(*cctx->env) * (env_len + 1));
 864                 for (i = 0; i < env_len; i++)
 865                         cctx->env[i] = buffer_get_string(&m, &len);
 866                 cctx->env[i] = NULL;
 867         }
 868
 869         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 870             cctx->want_tty, cctx->want_subsys, cmd);
 871
 872         /* Gather fds from client */
 873         new_fd[0] = mm_receive_fd(client_fd);
 874         new_fd[1] = mm_receive_fd(client_fd);
 875         new_fd[2] = mm_receive_fd(client_fd);
 876
 877         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 878             new_fd[0], new_fd[1], new_fd[2]);
 879
 880         /* Try to pick up ttymodes from client before it goes raw */
 881         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 882                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 883
 884         /* This roundtrip is just for synchronisation of ttymodes */
 885         buffer_clear(&m);
 886         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 887                 error("%s: client msg_send failed", __func__);
 888                 close(client_fd);
 889                 close(new_fd[0]);
 890                 close(new_fd[1]);
 891                 close(new_fd[2]);
 892                 buffer_free(&m);
 893                 xfree(cctx->term);
 894                 if (env_len != 0) {
 895                         for (i = 0; i < env_len; i++)
 896                                 xfree(cctx->env[i]);
 897                         xfree(cctx->env);
 898                 }
 899                 return;
 900         }
 901         buffer_free(&m);
 902
 903         /* enable nonblocking unless tty */
 904         if (!isatty(new_fd[0]))
 905                 set_nonblock(new_fd[0]);
 906         if (!isatty(new_fd[1]))
 907                 set_nonblock(new_fd[1]);
 908         if (!isatty(new_fd[2]))
 909                 set_nonblock(new_fd[2]);
 910
 911         set_nonblock(client_fd);
 912
 913         if (options.hpn_disabled)
 914                 c = channel_new("session", SSH_CHANNEL_OPENING,
 915                     new_fd[0], new_fd[1], new_fd[2],
 916                     CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
 917                     CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 918         else
 919                 c = channel_new("session", SSH_CHANNEL_OPENING,
 920                     new_fd[0], new_fd[1], new_fd[2],
 921                     options.hpn_buffer_size, CHAN_SES_PACKET_DEFAULT,
 922                     CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 923         /* XXX */
 924         c->ctl_fd = client_fd;
 925
 926         debug3("%s: channel_new: %d", __func__, c->self);
 927
 928         channel_send_open(c->self);
 929         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 930 }
 931
 932 static void
 933 process_cmdline(void)
 934 {
 935         void (*handler)(int);
 936         char *s, *cmd, *cancel_host;
 937         int delete = 0;
 938         int local = 0;
 939         u_short cancel_port;
 940         Forward fwd;
 941
 942         leave_raw_mode();
 943         handler = signal(SIGINT, SIG_IGN);
 944         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 945         if (s == NULL)
 946                 goto out;
 947         while (*s && isspace(*s))
 948                 s++;
 949         if (*s == '-')
 950                 s++;    /* Skip cmdline '-', if any */
 951         if (*s == '\0')
 952                 goto out;
 953
 954         if (*s == 'h' || *s == 'H' || *s == '?') {
 955                 logit("Commands:");
 956                 logit("      -Lport:host:hostport    Request local forward");
 957                 logit("      -Rport:host:hostport    Request remote forward");
 958                 logit("      -KRhostport             Cancel remote forward");
 959                 if (!options.permit_local_command)
 960                         goto out;
 961                 logit("      !args                   Execute local command");
 962                 goto out;
 963         }
 964
 965         if (*s == '!' && options.permit_local_command) {
 966                 s++;
 967                 ssh_local_cmd(s);
 968                 goto out;
 969         }
 970
 971         if (*s == 'K') {
 972                 delete = 1;
 973                 s++;
 974         }
 975         if (*s != 'L' && *s != 'R') {
 976                 logit("Invalid command.");
 977                 goto out;
 978         }
 979         if (*s == 'L')
 980                 local = 1;
 981         if (local && delete) {
 982                 logit("Not supported.");
 983                 goto out;
 984         }
 985         if ((!local || delete) && !compat20) {
 986                 logit("Not supported for SSH protocol version 1.");
 987                 goto out;
 988         }
 989
 990         s++;
 991         while (*s && isspace(*s))
 992                 s++;
 993
 994         if (delete) {
 995                 cancel_port = 0;
 996                 cancel_host = hpdelim(&s);      /* may be NULL */
 997                 if (s != NULL) {
 998                         cancel_port = a2port(s);
 999                         cancel_host = cleanhostname(cancel_host);
1000                 } else {
1001                         cancel_port = a2port(cancel_host);
1002                         cancel_host = NULL;
1003                 }
1004                 if (cancel_port == 0) {
1005                         logit("Bad forwarding close port");
1006                         goto out;
1007                 }
1008                 channel_request_rforward_cancel(cancel_host, cancel_port);
1009         } else {
1010                 if (!parse_forward(&fwd, s)) {
1011                         logit("Bad forwarding specification.");
1012                         goto out;
1013                 }
1014                 if (local) {
1015                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1016                             fwd.listen_port, fwd.connect_host,
1017                             fwd.connect_port, options.gateway_ports,
1018                             options.hpn_disabled, options.hpn_buffer_size) < 0) {
1019                                 logit("Port forwarding failed.");
1020                                 goto out;
1021                         }
1022                 } else {
1023                         channel_request_remote_forwarding(fwd.listen_host,
1024                             fwd.listen_port, fwd.connect_host,
1025                             fwd.connect_port);
1026                 }
1027
1028                 logit("Forwarding port.");
1029         }
1030
1031 out:
1032         signal(SIGINT, handler);
1033         enter_raw_mode();
1034         if (cmd)
1035                 xfree(cmd);
1036 }
1037
1038 /* process the characters one by one */
1039 static int
1040 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1041 {
1042         char string[1024];
1043         pid_t pid;
1044         int bytes = 0;
1045         u_int i;
1046         u_char ch;
1047         char *s;
1048
1049         if (len <= 0)
1050                 return (0);
1051
1052         for (i = 0; i < (u_int)len; i++) {
1053                 /* Get one character at a time. */
1054                 ch = buf[i];
1055
1056                 if (escape_pending) {
1057                         /* We have previously seen an escape character. */
1058                         /* Clear the flag now. */
1059                         escape_pending = 0;
1060
1061                         /* Process the escaped character. */
1062                         switch (ch) {
1063                         case '.':
1064                                 /* Terminate the connection. */
1065                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1066                                 buffer_append(berr, string, strlen(string));
1067
1068                                 quit_pending = 1;
1069                                 return -1;
1070
1071                         case 'Z' - 64:
1072                                 /* Suspend the program. */
1073                                 /* Print a message to that effect to the user. */
1074                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1075                                 buffer_append(berr, string, strlen(string));
1076
1077                                 /* Restore terminal modes and suspend. */
1078                                 client_suspend_self(bin, bout, berr);
1079
1080                                 /* We have been continued. */
1081                                 continue;
1082
1083                         case 'B':
1084                                 if (compat20) {
1085                                         snprintf(string, sizeof string,
1086                                             "%cB\r\n", escape_char);
1087                                         buffer_append(berr, string,
1088                                             strlen(string));
1089                                         channel_request_start(session_ident,
1090                                             "break", 0);
1091                                         packet_put_int(1000);
1092                                         packet_send();
1093                                 }
1094                                 continue;
1095
1096                         case 'R':
1097                                 if (compat20) {
1098                                         if (datafellows & SSH_BUG_NOREKEY)
1099                                                 logit("Server does not support re-keying");
1100                                         else
1101                                                 need_rekeying = 1;
1102                                 }
1103                                 continue;
1104
1105                         case '&':
1106                                 /*
1107                                  * Detach the program (continue to serve connections,
1108                                  * but put in background and no more new connections).
1109                                  */
1110                                 /* Restore tty modes. */
1111                                 leave_raw_mode();
1112
1113                                 /* Stop listening for new connections. */
1114                                 channel_stop_listening();
1115
1116                                 snprintf(string, sizeof string,
1117                                     "%c& [backgrounded]\n", escape_char);
1118                                 buffer_append(berr, string, strlen(string));
1119
1120                                 /* Fork into background. */
1121                                 pid = fork();
1122                                 if (pid < 0) {
1123                                         error("fork: %.100s", strerror(errno));
1124                                         continue;
1125                                 }
1126                                 if (pid != 0) { /* This is the parent. */
1127                                         /* The parent just exits. */
1128                                         exit(0);
1129                                 }
1130                                 /* The child continues serving connections. */
1131                                 if (compat20) {
1132                                         buffer_append(bin, "\004", 1);
1133                                         /* fake EOF on stdin */
1134                                         return -1;
1135                                 } else if (!stdin_eof) {
1136                                         /*
1137                                          * Sending SSH_CMSG_EOF alone does not always appear
1138                                          * to be enough.  So we try to send an EOF character
1139                                          * first.
1140                                          */
1141                                         packet_start(SSH_CMSG_STDIN_DATA);
1142                                         packet_put_string("\004", 1);
1143                                         packet_send();
1144                                         /* Close stdin. */
1145                                         stdin_eof = 1;
1146                                         if (buffer_len(bin) == 0) {
1147                                                 packet_start(SSH_CMSG_EOF);
1148                                                 packet_send();
1149                                         }
1150                                 }
1151                                 continue;
1152
1153                         case '?':
1154                                 snprintf(string, sizeof string,
1155 "%c?\r\n\
1156 Supported escape sequences:\r\n\
1157 %c.  - terminate connection\r\n\
1158 %cB  - send a BREAK to the remote system\r\n\
1159 %cC  - open a command line\r\n\
1160 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1161 %c^Z - suspend ssh\r\n\
1162 %c#  - list forwarded connections\r\n\
1163 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1164 %c?  - this message\r\n\
1165 %c%c  - send the escape character by typing it twice\r\n\
1166 (Note that escapes are only recognized immediately after newline.)\r\n",
1167                                     escape_char, escape_char, escape_char, escape_char,
1168                                     escape_char, escape_char, escape_char, escape_char,
1169                                     escape_char, escape_char, escape_char);
1170                                 buffer_append(berr, string, strlen(string));
1171                                 continue;
1172
1173                         case '#':
1174                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1175                                 buffer_append(berr, string, strlen(string));
1176                                 s = channel_open_message();
1177                                 buffer_append(berr, s, strlen(s));
1178                                 xfree(s);
1179                                 continue;
1180
1181                         case 'C':
1182                                 process_cmdline();
1183                                 continue;
1184
1185                         default:
1186                                 if (ch != escape_char) {
1187                                         buffer_put_char(bin, escape_char);
1188                                         bytes++;
1189                                 }
1190                                 /* Escaped characters fall through here */
1191                                 break;
1192                         }
1193                 } else {
1194                         /*
1195                          * The previous character was not an escape char. Check if this
1196                          * is an escape.
1197                          */
1198                         if (last_was_cr && ch == escape_char) {
1199                                 /* It is. Set the flag and continue to next character. */
1200                                 escape_pending = 1;
1201                                 continue;
1202                         }
1203                 }
1204
1205                 /*
1206                  * Normal character.  Record whether it was a newline,
1207                  * and append it to the buffer.
1208                  */
1209                 last_was_cr = (ch == '\r' || ch == '\n');
1210                 buffer_put_char(bin, ch);
1211                 bytes++;
1212         }
1213         return bytes;
1214 }
1215
1216 static void
1217 client_process_input(fd_set * readset)
1218 {
1219         int len;
1220         char buf[8192];
1221
1222         /* Read input from stdin. */
1223         if (FD_ISSET(fileno(stdin), readset)) {
1224                 /* Read as much as possible. */
1225                 len = read(fileno(stdin), buf, sizeof(buf));
1226                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1227                         return;         /* we'll try again later */
1228                 if (len <= 0) {
1229                         /*
1230                          * Received EOF or error.  They are treated
1231                          * similarly, except that an error message is printed
1232                          * if it was an error condition.
1233                          */
1234                         if (len < 0) {
1235                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1236                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1237                         }
1238                         /* Mark that we have seen EOF. */
1239                         stdin_eof = 1;
1240                         /*
1241                          * Send an EOF message to the server unless there is
1242                          * data in the buffer.  If there is data in the
1243                          * buffer, no message will be sent now.  Code
1244                          * elsewhere will send the EOF when the buffer
1245                          * becomes empty if stdin_eof is set.
1246                          */
1247                         if (buffer_len(&stdin_buffer) == 0) {
1248                                 packet_start(SSH_CMSG_EOF);
1249                                 packet_send();
1250                         }
1251                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1252                         /*
1253                          * Normal successful read, and no escape character.
1254                          * Just append the data to buffer.
1255                          */
1256                         buffer_append(&stdin_buffer, buf, len);
1257                 } else {
1258                         /*
1259                          * Normal, successful read.  But we have an escape character
1260                          * and have to process the characters one by one.
1261                          */
1262                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1263                             &stderr_buffer, buf, len) == -1)
1264                                 return;
1265                 }
1266         }
1267 }
1268
1269 static void
1270 client_process_output(fd_set * writeset)
1271 {
1272         int len;
1273         char buf[100];
1274
1275         /* Write buffered output to stdout. */
1276         if (FD_ISSET(fileno(stdout), writeset)) {
1277                 /* Write as much data as possible. */
1278                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1279                     buffer_len(&stdout_buffer));
1280                 if (len <= 0) {
1281                         if (errno == EINTR || errno == EAGAIN)
1282                                 len = 0;
1283                         else {
1284                                 /*
1285                                  * An error or EOF was encountered.  Put an
1286                                  * error message to stderr buffer.
1287                                  */
1288                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1289                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1290                                 quit_pending = 1;
1291                                 return;
1292                         }
1293                 }
1294                 /* Consume printed data from the buffer. */
1295                 buffer_consume(&stdout_buffer, len);
1296                 stdout_bytes += len;
1297         }
1298         /* Write buffered output to stderr. */
1299         if (FD_ISSET(fileno(stderr), writeset)) {
1300                 /* Write as much data as possible. */
1301                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1302                     buffer_len(&stderr_buffer));
1303                 if (len <= 0) {
1304                         if (errno == EINTR || errno == EAGAIN)
1305                                 len = 0;
1306                         else {
1307                                 /* EOF or error, but can't even print error message. */
1308                                 quit_pending = 1;
1309                                 return;
1310                         }
1311                 }
1312                 /* Consume printed characters from the buffer. */
1313                 buffer_consume(&stderr_buffer, len);
1314                 stderr_bytes += len;
1315         }
1316 }
1317
1318 /*
1319  * Get packets from the connection input buffer, and process them as long as
1320  * there are packets available.
1321  *
1322  * Any unknown packets received during the actual
1323  * session cause the session to terminate.  This is
1324  * intended to make debugging easier since no
1325  * confirmations are sent.  Any compatible protocol
1326  * extensions must be negotiated during the
1327  * preparatory phase.
1328  */
1329
1330 static void
1331 client_process_buffered_input_packets(void)
1332 {
1333         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1334 }
1335
1336 /* scan buf[] for '~' before sending data to the peer */
1337
1338 static int
1339 simple_escape_filter(Channel *c, char *buf, int len)
1340 {
1341         /* XXX we assume c->extended is writeable */
1342         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1343 }
1344
1345 static void
1346 client_channel_closed(int id, void *arg)
1347 {
1348         channel_cancel_cleanup(id);
1349         session_closed = 1;
1350         leave_raw_mode();
1351 }
1352
1353 /*
1354  * Implements the interactive session with the server.  This is called after
1355  * the user has been authenticated, and a command has been started on the
1356  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1357  * used as an escape character for terminating or suspending the session.
1358  */
1359
1360 int
1361 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1362 {
1363         fd_set *readset = NULL, *writeset = NULL;
1364         double start_time, total_time;
1365         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1366         u_int nalloc = 0;
1367         char buf[100];
1368
1369         debug("Entering interactive session.");
1370
1371         start_time = get_current_time();
1372
1373         /* Initialize variables. */
1374         escape_pending = 0;
1375         last_was_cr = 1;
1376         exit_status = -1;
1377         stdin_eof = 0;
1378         buffer_high = 64 * 1024;
1379         connection_in = packet_get_connection_in();
1380         connection_out = packet_get_connection_out();
1381         max_fd = MAX(connection_in, connection_out);
1382         if (control_fd != -1)
1383                 max_fd = MAX(max_fd, control_fd);
1384
1385         if (!compat20) {
1386                 /* enable nonblocking unless tty */
1387                 if (!isatty(fileno(stdin)))
1388                         set_nonblock(fileno(stdin));
1389                 if (!isatty(fileno(stdout)))
1390                         set_nonblock(fileno(stdout));
1391                 if (!isatty(fileno(stderr)))
1392                         set_nonblock(fileno(stderr));
1393                 max_fd = MAX(max_fd, fileno(stdin));
1394                 max_fd = MAX(max_fd, fileno(stdout));
1395                 max_fd = MAX(max_fd, fileno(stderr));
1396         }
1397         stdin_bytes = 0;
1398         stdout_bytes = 0;
1399         stderr_bytes = 0;
1400         quit_pending = 0;
1401         escape_char = escape_char_arg;
1402
1403         /* Initialize buffers. */
1404         buffer_init(&stdin_buffer);
1405         buffer_init(&stdout_buffer);
1406         buffer_init(&stderr_buffer);
1407
1408         client_init_dispatch();
1409
1410         /*
1411          * Set signal handlers, (e.g. to restore non-blocking mode)
1412          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1413          */
1414         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1415                 signal(SIGHUP, signal_handler);
1416         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1417                 signal(SIGINT, signal_handler);
1418         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1419                 signal(SIGQUIT, signal_handler);
1420         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1421                 signal(SIGTERM, signal_handler);
1422         signal(SIGWINCH, window_change_handler);
1423
1424         if (have_pty)
1425                 enter_raw_mode();
1426
1427         if (compat20) {
1428                 session_ident = ssh2_chan_id;
1429                 if (escape_char != SSH_ESCAPECHAR_NONE)
1430                         channel_register_filter(session_ident,
1431                             simple_escape_filter, NULL);
1432                 if (session_ident != -1)
1433                         channel_register_cleanup(session_ident,
1434                             client_channel_closed, 0);
1435         } else {
1436                 /* Check if we should immediately send eof on stdin. */
1437                 client_check_initial_eof_on_stdin();
1438         }
1439
1440         /* Main loop of the client for the interactive session mode. */
1441         while (!quit_pending) {
1442
1443                 /* Process buffered packets sent by the server. */
1444                 client_process_buffered_input_packets();
1445
1446                 if (compat20 && session_closed && !channel_still_open())
1447                         break;
1448
1449                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1450
1451                 if (rekeying) {
1452                         debug("rekeying in progress");
1453                 } else {
1454                         /*
1455                          * Make packets of buffered stdin data, and buffer
1456                          * them for sending to the server.
1457                          */
1458                         if (!compat20)
1459                                 client_make_packets_from_stdin_data();
1460
1461                         /*
1462                          * Make packets from buffered channel data, and
1463                          * enqueue them for sending to the server.
1464                          */
1465                         if (packet_not_very_much_data_to_write())
1466                                 channel_output_poll();
1467
1468                         /*
1469                          * Check if the window size has changed, and buffer a
1470                          * message about it to the server if so.
1471                          */
1472                         client_check_window_change();
1473
1474                         if (quit_pending)
1475                                 break;
1476                 }
1477                 /*
1478                  * Wait until we have something to do (something becomes
1479                  * available on one of the descriptors).
1480                  */
1481                 max_fd2 = max_fd;
1482                 client_wait_until_can_do_something(&readset, &writeset,
1483                     &max_fd2, &nalloc, rekeying);
1484
1485                 if (quit_pending)
1486                         break;
1487
1488                 /* Do channel operations unless rekeying in progress. */
1489                 if (!rekeying) {
1490                         channel_after_select(readset, writeset);
1491                         if (need_rekeying || packet_need_rekeying()) {
1492                                 debug("need rekeying");
1493                                 xxx_kex->done = 0;
1494                                 kex_send_kexinit(xxx_kex);
1495                                 need_rekeying = 0;
1496                         }
1497                 }
1498
1499                 /* Buffer input from the connection.  */
1500                 client_process_net_input(readset);
1501
1502                 /* Accept control connections.  */
1503                 client_process_control(readset);
1504
1505                 if (quit_pending)
1506                         break;
1507
1508                 if (!compat20) {
1509                         /* Buffer data from stdin */
1510                         client_process_input(readset);
1511                         /*
1512                          * Process output to stdout and stderr.  Output to
1513                          * the connection is processed elsewhere (above).
1514                          */
1515                         client_process_output(writeset);
1516                 }
1517
1518                 /* Send as much buffered packet data as possible to the sender. */
1519                 if (FD_ISSET(connection_out, writeset))
1520                         packet_write_poll();
1521         }
1522         if (readset)
1523                 xfree(readset);
1524         if (writeset)
1525                 xfree(writeset);
1526
1527         /* Terminate the session. */
1528
1529         /* Stop watching for window change. */
1530         signal(SIGWINCH, SIG_DFL);
1531
1532         channel_free_all();
1533
1534         if (have_pty)
1535                 leave_raw_mode();
1536
1537         /* restore blocking io */
1538         if (!isatty(fileno(stdin)))
1539                 unset_nonblock(fileno(stdin));
1540         if (!isatty(fileno(stdout)))
1541                 unset_nonblock(fileno(stdout));
1542         if (!isatty(fileno(stderr)))
1543                 unset_nonblock(fileno(stderr));
1544
1545         /*
1546          * If there was no shell or command requested, there will be no remote
1547          * exit status to be returned.  In that case, clear error code if the
1548          * connection was deliberately terminated at this end.
1549          */
1550         if (no_shell_flag && received_signal == SIGTERM) {
1551                 received_signal = 0;
1552                 exit_status = 0;
1553         }
1554
1555         if (received_signal)
1556                 fatal("Killed by signal %d.", (int) received_signal);
1557
1558         /*
1559          * In interactive mode (with pseudo tty) display a message indicating
1560          * that the connection has been closed.
1561          */
1562         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1563                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1564                 buffer_append(&stderr_buffer, buf, strlen(buf));
1565         }
1566
1567         /* Output any buffered data for stdout. */
1568         while (buffer_len(&stdout_buffer) > 0) {
1569                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1570                     buffer_len(&stdout_buffer));
1571                 if (len <= 0) {
1572                         error("Write failed flushing stdout buffer.");
1573                         break;
1574                 }
1575                 buffer_consume(&stdout_buffer, len);
1576                 stdout_bytes += len;
1577         }
1578
1579         /* Output any buffered data for stderr. */
1580         while (buffer_len(&stderr_buffer) > 0) {
1581                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1582                     buffer_len(&stderr_buffer));
1583                 if (len <= 0) {
1584                         error("Write failed flushing stderr buffer.");
1585                         break;
1586                 }
1587                 buffer_consume(&stderr_buffer, len);
1588                 stderr_bytes += len;
1589         }
1590
1591         /* Clear and free any buffers. */
1592         memset(buf, 0, sizeof(buf));
1593         buffer_free(&stdin_buffer);
1594         buffer_free(&stdout_buffer);
1595         buffer_free(&stderr_buffer);
1596
1597         /* Report bytes transferred, and transfer rates. */
1598         total_time = get_current_time() - start_time;
1599         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1600             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1601         if (total_time > 0)
1602                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1603                     stdin_bytes / total_time, stdout_bytes / total_time,
1604                     stderr_bytes / total_time);
1605
1606         /* Return the exit status of the program. */
1607         debug("Exit status %d", exit_status);
1608         return exit_status;
1609 }
1610
1611 /*********/
1612
1613 static void
1614 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1615 {
1616         u_int data_len;
1617         char *data = packet_get_string(&data_len);
1618         packet_check_eom();
1619         buffer_append(&stdout_buffer, data, data_len);
1620         memset(data, 0, data_len);
1621         xfree(data);
1622 }
1623 static void
1624 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1625 {
1626         u_int data_len;
1627         char *data = packet_get_string(&data_len);
1628         packet_check_eom();
1629         buffer_append(&stderr_buffer, data, data_len);
1630         memset(data, 0, data_len);
1631         xfree(data);
1632 }
1633 static void
1634 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1635 {
1636         exit_status = packet_get_int();
1637         packet_check_eom();
1638         /* Acknowledge the exit. */
1639         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1640         packet_send();
1641         /*
1642          * Must wait for packet to be sent since we are
1643          * exiting the loop.
1644          */
1645         packet_write_wait();
1646         /* Flag that we want to exit. */
1647         quit_pending = 1;
1648 }
1649 static void
1650 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1651 {
1652         Channel *c = NULL;
1653         int remote_id, sock;
1654
1655         /* Read the remote channel number from the message. */
1656         remote_id = packet_get_int();
1657         packet_check_eom();
1658
1659         /*
1660          * Get a connection to the local authentication agent (this may again
1661          * get forwarded).
1662          */
1663         sock = ssh_get_authentication_socket();
1664
1665         /*
1666          * If we could not connect the agent, send an error message back to
1667          * the server. This should never happen unless the agent dies,
1668          * because authentication forwarding is only enabled if we have an
1669          * agent.
1670          */
1671         if (sock >= 0) {
1672                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1673                     -1, 0, 0, 0, "authentication agent connection", 1);
1674                 c->remote_id = remote_id;
1675                 c->force_drain = 1;
1676         }
1677         if (c == NULL) {
1678                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1679                 packet_put_int(remote_id);
1680         } else {
1681                 /* Send a confirmation to the remote host. */
1682                 debug("Forwarding authentication connection.");
1683                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1684                 packet_put_int(remote_id);
1685                 packet_put_int(c->self);
1686         }
1687         packet_send();
1688 }
1689
1690 static Channel *
1691 client_request_forwarded_tcpip(const char *request_type, int rchan)
1692 {
1693         Channel *c = NULL;
1694         char *listen_address, *originator_address;
1695         int listen_port, originator_port;
1696         int sock;
1697
1698         /* Get rest of the packet */
1699         listen_address = packet_get_string(NULL);
1700         listen_port = packet_get_int();
1701         originator_address = packet_get_string(NULL);
1702         originator_port = packet_get_int();
1703         packet_check_eom();
1704
1705         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1706             listen_address, listen_port, originator_address, originator_port);
1707
1708         sock = channel_connect_by_listen_address(listen_port);
1709         if (sock < 0) {
1710                 xfree(originator_address);
1711                 xfree(listen_address);
1712                 return NULL;
1713         }
1714         if (options.hpn_disabled)
1715                 c = channel_new("forwarded-tcpip",
1716                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1717                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1718                     originator_address, 1);
1719         else
1720                 c = channel_new("forwarded-tcpip",
1721                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1722                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1723                     originator_address, 1);
1724         xfree(originator_address);
1725         xfree(listen_address);
1726         return c;
1727 }
1728
1729 static Channel *
1730 client_request_x11(const char *request_type, int rchan)
1731 {
1732         Channel *c = NULL;
1733         char *originator;
1734         int originator_port;
1735         int sock;
1736
1737         if (!options.forward_x11) {
1738                 error("Warning: ssh server tried X11 forwarding.");
1739                 error("Warning: this is probably a break-in attempt by a malicious server.");
1740                 return NULL;
1741         }
1742         originator = packet_get_string(NULL);
1743         if (datafellows & SSH_BUG_X11FWD) {
1744                 debug2("buggy server: x11 request w/o originator_port");
1745                 originator_port = 0;
1746         } else {
1747                 originator_port = packet_get_int();
1748         }
1749         packet_check_eom();
1750         /* XXX check permission */
1751         debug("client_request_x11: request from %s %d", originator,
1752             originator_port);
1753         xfree(originator);
1754         sock = x11_connect_display();
1755         if (sock < 0)
1756                 return NULL;
1757         if (options.hpn_disabled)
1758                 c = channel_new("x11",
1759                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1760                     CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1761         else
1762                 c = channel_new("x11",
1763                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1764                     options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1765         c->force_drain = 1;
1766         return c;
1767 }
1768
1769 static Channel *
1770 client_request_agent(const char *request_type, int rchan)
1771 {
1772         Channel *c = NULL;
1773         int sock;
1774
1775         if (!options.forward_agent) {
1776                 error("Warning: ssh server tried agent forwarding.");
1777                 error("Warning: this is probably a break-in attempt by a malicious server.");
1778                 return NULL;
1779         }
1780         sock =  ssh_get_authentication_socket();
1781         if (sock < 0)
1782                 return NULL;
1783         if (options.hpn_disabled)
1784                 c = channel_new("authentication agent connection",
1785                     SSH_CHANNEL_OPEN, sock, sock, -1,
1786                     CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1787                     "authentication agent connection", 1);
1788         else
1789                 c = channel_new("authentication agent connection",
1790                     SSH_CHANNEL_OPEN, sock, sock, -1,
1791                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1792                     "authentication agent connection", 1);
1793         c->force_drain = 1;
1794         return c;
1795 }
1796
1797 /* XXXX move to generic input handler */
1798 static void
1799 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1800 {
1801         Channel *c = NULL;
1802         char *ctype;
1803         int rchan;
1804         u_int rmaxpack, rwindow, len;
1805
1806         ctype = packet_get_string(&len);
1807         rchan = packet_get_int();
1808         rwindow = packet_get_int();
1809         rmaxpack = packet_get_int();
1810
1811         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1812             ctype, rchan, rwindow, rmaxpack);
1813
1814         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1815                 c = client_request_forwarded_tcpip(ctype, rchan);
1816         } else if (strcmp(ctype, "x11") == 0) {
1817                 c = client_request_x11(ctype, rchan);
1818         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1819                 c = client_request_agent(ctype, rchan);
1820         }
1821 /* XXX duplicate : */
1822         if (c != NULL) {
1823                 debug("confirm %s", ctype);
1824                 c->remote_id = rchan;
1825                 c->remote_window = rwindow;
1826                 c->remote_maxpacket = rmaxpack;
1827                 if (c->type != SSH_CHANNEL_CONNECTING) {
1828                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1829                         packet_put_int(c->remote_id);
1830                         packet_put_int(c->self);
1831                         packet_put_int(c->local_window);
1832                         packet_put_int(c->local_maxpacket);
1833                         packet_send();
1834                 }
1835         } else {
1836                 debug("failure %s", ctype);
1837                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1838                 packet_put_int(rchan);
1839                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1840                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1841                         packet_put_cstring("open failed");
1842                         packet_put_cstring("");
1843                 }
1844                 packet_send();
1845         }
1846         xfree(ctype);
1847 }
1848 static void
1849 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1850 {
1851         Channel *c = NULL;
1852         int exitval, id, reply, success = 0;
1853         char *rtype;
1854
1855         id = packet_get_int();
1856         rtype = packet_get_string(NULL);
1857         reply = packet_get_char();
1858
1859         debug("client_input_channel_req: channel %d rtype %s reply %d",
1860             id, rtype, reply);
1861
1862         if (id == -1) {
1863                 error("client_input_channel_req: request for channel -1");
1864         } else if ((c = channel_lookup(id)) == NULL) {
1865                 error("client_input_channel_req: channel %d: unknown channel", id);
1866         } else if (strcmp(rtype, "exit-status") == 0) {
1867                 exitval = packet_get_int();
1868                 if (id == session_ident) {
1869                         success = 1;
1870                         exit_status = exitval;
1871                 } else if (c->ctl_fd == -1) {
1872                         error("client_input_channel_req: unexpected channel %d",
1873                             session_ident);
1874                 } else {
1875                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1876                         success = 1;
1877                 }
1878                 packet_check_eom();
1879         }
1880         if (reply) {
1881                 packet_start(success ?
1882                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1883                 packet_put_int(id);
1884                 packet_send();
1885         }
1886         xfree(rtype);
1887 }
1888 static void
1889 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1890 {
1891         char *rtype;
1892         int want_reply;
1893         int success = 0;
1894
1895         rtype = packet_get_string(NULL);
1896         want_reply = packet_get_char();
1897         debug("client_input_global_request: rtype %s want_reply %d",
1898             rtype, want_reply);
1899         if (want_reply) {
1900                 packet_start(success ?
1901                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1902                 packet_send();
1903                 packet_write_wait();
1904         }
1905         xfree(rtype);
1906 }
1907
1908 void
1909 client_session2_setup(int id, int want_tty, int want_subsystem,
1910     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1911     dispatch_fn *subsys_repl)
1912 {
1913         int len;
1914         Channel *c = NULL;
1915
1916         debug2("%s: id %d", __func__, id);
1917
1918         if ((c = channel_lookup(id)) == NULL)
1919                 fatal("client_session2_setup: channel %d: unknown channel", id);
1920
1921         if (want_tty) {
1922                 struct winsize ws;
1923                 struct termios tio;
1924
1925                 /* Store window size in the packet. */
1926                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1927                         memset(&ws, 0, sizeof(ws));
1928
1929                 channel_request_start(id, "pty-req", 0);
1930                 packet_put_cstring(term != NULL ? term : "");
1931                 packet_put_int(ws.ws_col);
1932                 packet_put_int(ws.ws_row);
1933                 packet_put_int(ws.ws_xpixel);
1934                 packet_put_int(ws.ws_ypixel);
1935                 tio = get_saved_tio();
1936                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1937                 packet_send();
1938                 /* XXX wait for reply */
1939                 c->client_tty = 1;
1940         }
1941
1942         /* Transfer any environment variables from client to server */
1943         if (options.num_send_env != 0 && env != NULL) {
1944                 int i, j, matched;
1945                 char *name, *val;
1946
1947                 debug("Sending environment.");
1948                 for (i = 0; env[i] != NULL; i++) {
1949                         /* Split */
1950                         name = xstrdup(env[i]);
1951                         if ((val = strchr(name, '=')) == NULL) {
1952                                 xfree(name);
1953                                 continue;
1954                         }
1955                         *val++ = '\0';
1956
1957                         matched = 0;
1958                         for (j = 0; j < options.num_send_env; j++) {
1959                                 if (match_pattern(name, options.send_env[j])) {
1960                                         matched = 1;
1961                                         break;
1962                                 }
1963                         }
1964                         if (!matched) {
1965                                 debug3("Ignored env %s", name);
1966                                 xfree(name);
1967                                 continue;
1968                         }
1969
1970                         debug("Sending env %s = %s", name, val);
1971                         channel_request_start(id, "env", 0);
1972                         packet_put_cstring(name);
1973                         packet_put_cstring(val);
1974                         packet_send();
1975                         xfree(name);
1976                 }
1977         }
1978
1979         len = buffer_len(cmd);
1980         if (len > 0) {
1981                 if (len > 900)
1982                         len = 900;
1983                 if (want_subsystem) {
1984                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
1985                         channel_request_start(id, "subsystem", subsys_repl != NULL);
1986                         if (subsys_repl != NULL) {
1987                                 /* register callback for reply */
1988                                 /* XXX we assume that client_loop has already been called */
1989                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
1990                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
1991                         }
1992                 } else {
1993                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
1994                         channel_request_start(id, "exec", 0);
1995                 }
1996                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
1997                 packet_send();
1998         } else {
1999                 channel_request_start(id, "shell", 0);
2000                 packet_send();
2001         }
2002 }
2003
2004 static void
2005 client_init_dispatch_20(void)
2006 {
2007         dispatch_init(&dispatch_protocol_error);
2008
2009         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2010         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2011         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2012         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2013         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2014         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2015         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2016         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2017         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2018         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2019
2020         /* rekeying */
2021         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2022
2023         /* global request reply messages */
2024         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2025         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2026 }
2027 static void
2028 client_init_dispatch_13(void)
2029 {
2030         dispatch_init(NULL);
2031         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2032         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2033         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2034         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2035         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2036         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2037         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2038         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2039         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2040
2041         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2042             &client_input_agent_open : &deny_input_open);
2043         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2044             &x11_input_open : &deny_input_open);
2045 }
2046 static void
2047 client_init_dispatch_15(void)
2048 {
2049         client_init_dispatch_13();
2050         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2051         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2052 }
2053 static void
2054 client_init_dispatch(void)
2055 {
2056         if (compat20)
2057                 client_init_dispatch_20();
2058         else if (compat13)
2059                 client_init_dispatch_13();
2060         else
2061                 client_init_dispatch_15();
2062 }
2063
2064 /* client specific fatal cleanup */
2065 void
2066 cleanup_exit(int i)
2067 {
2068         leave_raw_mode();
2069         leave_non_blocking();
2070         if (options.control_path != NULL && control_fd != -1)
2071                 unlink(options.control_path);
2072         _exit(i);
2073 }