openssh/clientloop.c

   1 /* $OpenBSD: clientloop.c,v 1.181 2007/08/15 08:14:46 markus 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  * The main loop for the interactive session (client side).
   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  *
  15  * Copyright (c) 1999 Theo de Raadt.  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  * SSH2 support added by Markus Friedl.
  39  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #include "includes.h"
  63
  64 #include <sys/types.h>
  65 #include <sys/ioctl.h>
  66 #include <sys/param.h>
  67 #ifdef HAVE_SYS_STAT_H
  68 # include <sys/stat.h>
  69 #endif
  70 #ifdef HAVE_SYS_TIME_H
  71 # include <sys/time.h>
  72 #endif
  73 #include <sys/socket.h>
  74
  75 #include <ctype.h>
  76 #include <errno.h>
  77 #ifdef HAVE_PATHS_H
  78 #include <paths.h>
  79 #endif
  80 #include <signal.h>
  81 #include <stdarg.h>
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <string.h>
  85 #include <termios.h>
  86 #include <pwd.h>
  87 #include <unistd.h>
  88
  89 #include "xmalloc.h"
  90 #include "ssh.h"
  91 #include "ssh1.h"
  92 #include "ssh2.h"
  93 #include "packet.h"
  94 #include "buffer.h"
  95 #include "compat.h"
  96 #include "channels.h"
  97 #include "dispatch.h"
  98 #include "key.h"
  99 #include "cipher.h"
 100 #include "kex.h"
 101 #include "log.h"
 102 #include "readconf.h"
 103 #include "clientloop.h"
 104 #include "sshconnect.h"
 105 #include "authfd.h"
 106 #include "atomicio.h"
 107 #include "sshpty.h"
 108 #include "misc.h"
 109 #include "monitor_fdpass.h"
 110 #include "match.h"
 111 #include "msg.h"
 112
 113 /* import options */
 114 extern Options options;
 115
 116 /* Flag indicating that stdin should be redirected from /dev/null. */
 117 extern int stdin_null_flag;
 118
 119 /* Flag indicating that no shell has been requested */
 120 extern int no_shell_flag;
 121
 122 /* Control socket */
 123 extern int control_fd;
 124
 125 /*
 126  * Name of the host we are connecting to.  This is the name given on the
 127  * command line, or the HostName specified for the user-supplied name in a
 128  * configuration file.
 129  */
 130 extern char *host;
 131
 132 /*
 133  * Flag to indicate that we have received a window change signal which has
 134  * not yet been processed.  This will cause a message indicating the new
 135  * window size to be sent to the server a little later.  This is volatile
 136  * because this is updated in a signal handler.
 137  */
 138 static volatile sig_atomic_t received_window_change_signal = 0;
 139 static volatile sig_atomic_t received_signal = 0;
 140
 141 /* Flag indicating whether the user's terminal is in non-blocking mode. */
 142 static int in_non_blocking_mode = 0;
 143
 144 /* Common data for the client loop code. */
 145 static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
 146 static int escape_char;         /* Escape character. */
 147 static int escape_pending;      /* Last character was the escape character */
 148 static int last_was_cr;         /* Last character was a newline. */
 149 static int exit_status;         /* Used to store the exit status of the command. */
 150 static int stdin_eof;           /* EOF has been encountered on standard error. */
 151 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 152 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 153 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 154 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 155 static u_int buffer_high;/* Soft max buffer size. */
 156 static int connection_in;       /* Connection to server (input). */
 157 static int connection_out;      /* Connection to server (output). */
 158 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 159 static int session_closed = 0;  /* In SSH2: login session closed. */
 160 static int server_alive_timeouts = 0;
 161
 162 static void client_init_dispatch(void);
 163 int     session_ident = -1;
 164
 165 struct confirm_ctx {
 166         int want_tty;
 167         int want_subsys;
 168         int want_x_fwd;
 169         int want_agent_fwd;
 170         Buffer cmd;
 171         char *term;
 172         struct termios tio;
 173         char **env;
 174 };
 175
 176 /*XXX*/
 177 extern Kex *xxx_kex;
 178
 179 void ssh_process_session2_setup(int, int, int, Buffer *);
 180
 181 /* Restores stdin to blocking mode. */
 182
 183 static void
 184 leave_non_blocking(void)
 185 {
 186         if (in_non_blocking_mode) {
 187                 unset_nonblock(fileno(stdin));
 188                 in_non_blocking_mode = 0;
 189         }
 190 }
 191
 192 /* Puts stdin terminal in non-blocking mode. */
 193
 194 static void
 195 enter_non_blocking(void)
 196 {
 197         in_non_blocking_mode = 1;
 198         set_nonblock(fileno(stdin));
 199 }
 200
 201 /*
 202  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 203  * flag indicating that the window has changed.
 204  */
 205 /*ARGSUSED */
 206 static void
 207 window_change_handler(int sig)
 208 {
 209         received_window_change_signal = 1;
 210         signal(SIGWINCH, window_change_handler);
 211 }
 212
 213 /*
 214  * Signal handler for signals that cause the program to terminate.  These
 215  * signals must be trapped to restore terminal modes.
 216  */
 217 /*ARGSUSED */
 218 static void
 219 signal_handler(int sig)
 220 {
 221         received_signal = sig;
 222         quit_pending = 1;
 223 }
 224
 225 /*
 226  * Returns current time in seconds from Jan 1, 1970 with the maximum
 227  * available resolution.
 228  */
 229
 230 static double
 231 get_current_time(void)
 232 {
 233         struct timeval tv;
 234         gettimeofday(&tv, NULL);
 235         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 236 }
 237
 238 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 239 void
 240 client_x11_get_proto(const char *display, const char *xauth_path,
 241     u_int trusted, char **_proto, char **_data)
 242 {
 243         char cmd[1024];
 244         char line[512];
 245         char xdisplay[512];
 246         static char proto[512], data[512];
 247         FILE *f;
 248         int got_data = 0, generated = 0, do_unlink = 0, i;
 249         char *xauthdir, *xauthfile;
 250         struct stat st;
 251
 252         xauthdir = xauthfile = NULL;
 253         *_proto = proto;
 254         *_data = data;
 255         proto[0] = data[0] = '\0';
 256
 257         if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
 258                 debug("No xauth program.");
 259         } else {
 260                 if (display == NULL) {
 261                         debug("x11_get_proto: DISPLAY not set");
 262                         return;
 263                 }
 264                 /*
 265                  * Handle FamilyLocal case where $DISPLAY does
 266                  * not match an authorization entry.  For this we
 267                  * just try "xauth list unix:displaynum.screennum".
 268                  * XXX: "localhost" match to determine FamilyLocal
 269                  *      is not perfect.
 270                  */
 271                 if (strncmp(display, "localhost:", 10) == 0) {
 272                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 273                             display + 10);
 274                         display = xdisplay;
 275                 }
 276                 if (trusted == 0) {
 277                         xauthdir = xmalloc(MAXPATHLEN);
 278                         xauthfile = xmalloc(MAXPATHLEN);
 279                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 280                         if (mkdtemp(xauthdir) != NULL) {
 281                                 do_unlink = 1;
 282                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 283                                     xauthdir);
 284                                 snprintf(cmd, sizeof(cmd),
 285                                     "%s -f %s generate %s " SSH_X11_PROTO
 286                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 287                                     xauth_path, xauthfile, display);
 288                                 debug2("x11_get_proto: %s", cmd);
 289                                 if (system(cmd) == 0)
 290                                         generated = 1;
 291                         }
 292                 }
 293
 294                 /*
 295                  * When in untrusted mode, we read the cookie only if it was
 296                  * successfully generated as an untrusted one in the step
 297                  * above.
 298                  */
 299                 if (trusted || generated) {
 300                         snprintf(cmd, sizeof(cmd),
 301                             "%s %s%s list %s 2>" _PATH_DEVNULL,
 302                             xauth_path,
 303                             generated ? "-f " : "" ,
 304                             generated ? xauthfile : "",
 305                             display);
 306                         debug2("x11_get_proto: %s", cmd);
 307                         f = popen(cmd, "r");
 308                         if (f && fgets(line, sizeof(line), f) &&
 309                             sscanf(line, "%*s %511s %511s", proto, data) == 2)
 310                                 got_data = 1;
 311                         if (f)
 312                                 pclose(f);
 313                 } else
 314                         error("Warning: untrusted X11 forwarding setup failed: "
 315                             "xauth key data not generated");
 316         }
 317
 318         if (do_unlink) {
 319                 unlink(xauthfile);
 320                 rmdir(xauthdir);
 321         }
 322         if (xauthdir)
 323                 xfree(xauthdir);
 324         if (xauthfile)
 325                 xfree(xauthfile);
 326
 327         /*
 328          * If we didn't get authentication data, just make up some
 329          * data.  The forwarding code will check the validity of the
 330          * response anyway, and substitute this data.  The X11
 331          * server, however, will ignore this fake data and use
 332          * whatever authentication mechanisms it was using otherwise
 333          * for the local connection.
 334          */
 335         if (!got_data) {
 336                 u_int32_t rnd = 0;
 337
 338                 logit("Warning: No xauth data; "
 339                     "using fake authentication data for X11 forwarding.");
 340                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 341                 for (i = 0; i < 16; i++) {
 342                         if (i % 4 == 0)
 343                                 rnd = arc4random();
 344                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 345                             rnd & 0xff);
 346                         rnd >>= 8;
 347                 }
 348         }
 349 }
 350
 351 /*
 352  * This is called when the interactive is entered.  This checks if there is
 353  * an EOF coming on stdin.  We must check this explicitly, as select() does
 354  * not appear to wake up when redirecting from /dev/null.
 355  */
 356
 357 static void
 358 client_check_initial_eof_on_stdin(void)
 359 {
 360         int len;
 361         char buf[1];
 362
 363         /*
 364          * If standard input is to be "redirected from /dev/null", we simply
 365          * mark that we have seen an EOF and send an EOF message to the
 366          * server. Otherwise, we try to read a single character; it appears
 367          * that for some files, such /dev/null, select() never wakes up for
 368          * read for this descriptor, which means that we never get EOF.  This
 369          * way we will get the EOF if stdin comes from /dev/null or similar.
 370          */
 371         if (stdin_null_flag) {
 372                 /* Fake EOF on stdin. */
 373                 debug("Sending eof.");
 374                 stdin_eof = 1;
 375                 packet_start(SSH_CMSG_EOF);
 376                 packet_send();
 377         } else {
 378                 enter_non_blocking();
 379
 380                 /* Check for immediate EOF on stdin. */
 381                 len = read(fileno(stdin), buf, 1);
 382                 if (len == 0) {
 383                         /* EOF.  Record that we have seen it and send EOF to server. */
 384                         debug("Sending eof.");
 385                         stdin_eof = 1;
 386                         packet_start(SSH_CMSG_EOF);
 387                         packet_send();
 388                 } else if (len > 0) {
 389                         /*
 390                          * Got data.  We must store the data in the buffer,
 391                          * and also process it as an escape character if
 392                          * appropriate.
 393                          */
 394                         if ((u_char) buf[0] == escape_char)
 395                                 escape_pending = 1;
 396                         else
 397                                 buffer_append(&stdin_buffer, buf, 1);
 398                 }
 399                 leave_non_blocking();
 400         }
 401 }
 402
 403
 404 /*
 405  * Make packets from buffered stdin data, and buffer them for sending to the
 406  * connection.
 407  */
 408
 409 static void
 410 client_make_packets_from_stdin_data(void)
 411 {
 412         u_int len;
 413
 414         /* Send buffered stdin data to the server. */
 415         while (buffer_len(&stdin_buffer) > 0 &&
 416             packet_not_very_much_data_to_write()) {
 417                 len = buffer_len(&stdin_buffer);
 418                 /* Keep the packets at reasonable size. */
 419                 if (len > packet_get_maxsize())
 420                         len = packet_get_maxsize();
 421                 packet_start(SSH_CMSG_STDIN_DATA);
 422                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 423                 packet_send();
 424                 buffer_consume(&stdin_buffer, len);
 425                 stdin_bytes += len;
 426                 /* If we have a pending EOF, send it now. */
 427                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 428                         packet_start(SSH_CMSG_EOF);
 429                         packet_send();
 430                 }
 431         }
 432 }
 433
 434 /*
 435  * Checks if the client window has changed, and sends a packet about it to
 436  * the server if so.  The actual change is detected elsewhere (by a software
 437  * interrupt on Unix); this just checks the flag and sends a message if
 438  * appropriate.
 439  */
 440
 441 static void
 442 client_check_window_change(void)
 443 {
 444         struct winsize ws;
 445
 446         if (! received_window_change_signal)
 447                 return;
 448         /** XXX race */
 449         received_window_change_signal = 0;
 450
 451         debug2("client_check_window_change: changed");
 452
 453         if (compat20) {
 454                 channel_send_window_changes();
 455         } else {
 456                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 457                         return;
 458                 packet_start(SSH_CMSG_WINDOW_SIZE);
 459                 packet_put_int((u_int)ws.ws_row);
 460                 packet_put_int((u_int)ws.ws_col);
 461                 packet_put_int((u_int)ws.ws_xpixel);
 462                 packet_put_int((u_int)ws.ws_ypixel);
 463                 packet_send();
 464         }
 465 }
 466
 467 static void
 468 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 469 {
 470         server_alive_timeouts = 0;
 471         client_global_request_reply_fwd(type, seq, ctxt);
 472 }
 473
 474 static void
 475 server_alive_check(void)
 476 {
 477         if (++server_alive_timeouts > options.server_alive_count_max) {
 478                 logit("Timeout, server not responding.");
 479                 cleanup_exit(255);
 480         }
 481         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 482         packet_put_cstring("keepalive@openssh.com");
 483         packet_put_char(1);     /* boolean: want reply */
 484         packet_send();
 485 }
 486
 487 /*
 488  * Waits until the client can do something (some data becomes available on
 489  * one of the file descriptors).
 490  */
 491 static void
 492 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 493     int *maxfdp, u_int *nallocp, int rekeying)
 494 {
 495         struct timeval tv, *tvp;
 496         int ret;
 497
 498         /* Add any selections by the channel mechanism. */
 499         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 500
 501         if (!compat20) {
 502                 /* Read from the connection, unless our buffers are full. */
 503                 if (buffer_len(&stdout_buffer) < buffer_high &&
 504                     buffer_len(&stderr_buffer) < buffer_high &&
 505                     channel_not_very_much_buffered_data())
 506                         FD_SET(connection_in, *readsetp);
 507                 /*
 508                  * Read from stdin, unless we have seen EOF or have very much
 509                  * buffered data to send to the server.
 510                  */
 511                 if (!stdin_eof && packet_not_very_much_data_to_write())
 512                         FD_SET(fileno(stdin), *readsetp);
 513
 514                 /* Select stdout/stderr if have data in buffer. */
 515                 if (buffer_len(&stdout_buffer) > 0)
 516                         FD_SET(fileno(stdout), *writesetp);
 517                 if (buffer_len(&stderr_buffer) > 0)
 518                         FD_SET(fileno(stderr), *writesetp);
 519         } else {
 520                 /* channel_prepare_select could have closed the last channel */
 521                 if (session_closed && !channel_still_open() &&
 522                     !packet_have_data_to_write()) {
 523                         /* clear mask since we did not call select() */
 524                         memset(*readsetp, 0, *nallocp);
 525                         memset(*writesetp, 0, *nallocp);
 526                         return;
 527                 } else {
 528                         FD_SET(connection_in, *readsetp);
 529                 }
 530         }
 531
 532         /* Select server connection if have data to write to the server. */
 533         if (packet_have_data_to_write())
 534                 FD_SET(connection_out, *writesetp);
 535
 536         if (control_fd != -1)
 537                 FD_SET(control_fd, *readsetp);
 538
 539         /*
 540          * Wait for something to happen.  This will suspend the process until
 541          * some selected descriptor can be read, written, or has some other
 542          * event pending.
 543          */
 544
 545         if (options.server_alive_interval == 0 || !compat20)
 546                 tvp = NULL;
 547         else {
 548                 tv.tv_sec = options.server_alive_interval;
 549                 tv.tv_usec = 0;
 550                 tvp = &tv;
 551         }
 552         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 553         if (ret < 0) {
 554                 char buf[100];
 555
 556                 /*
 557                  * We have to clear the select masks, because we return.
 558                  * We have to return, because the mainloop checks for the flags
 559                  * set by the signal handlers.
 560                  */
 561                 memset(*readsetp, 0, *nallocp);
 562                 memset(*writesetp, 0, *nallocp);
 563
 564                 if (errno == EINTR)
 565                         return;
 566                 /* Note: we might still have data in the buffers. */
 567                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 568                 buffer_append(&stderr_buffer, buf, strlen(buf));
 569                 quit_pending = 1;
 570         } else if (ret == 0)
 571                 server_alive_check();
 572 }
 573
 574 static void
 575 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 576 {
 577         /* Flush stdout and stderr buffers. */
 578         if (buffer_len(bout) > 0)
 579                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 580         if (buffer_len(berr) > 0)
 581                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 582
 583         leave_raw_mode();
 584
 585         /*
 586          * Free (and clear) the buffer to reduce the amount of data that gets
 587          * written to swap.
 588          */
 589         buffer_free(bin);
 590         buffer_free(bout);
 591         buffer_free(berr);
 592
 593         /* Send the suspend signal to the program itself. */
 594         kill(getpid(), SIGTSTP);
 595
 596         /* Reset window sizes in case they have changed */
 597         received_window_change_signal = 1;
 598
 599         /* OK, we have been continued by the user. Reinitialize buffers. */
 600         buffer_init(bin);
 601         buffer_init(bout);
 602         buffer_init(berr);
 603
 604         enter_raw_mode();
 605 }
 606
 607 static void
 608 client_process_net_input(fd_set *readset)
 609 {
 610         int len;
 611         char buf[8192];
 612
 613         /*
 614          * Read input from the server, and add any such data to the buffer of
 615          * the packet subsystem.
 616          */
 617         if (FD_ISSET(connection_in, readset)) {
 618                 /* Read as much as possible. */
 619                 len = read(connection_in, buf, sizeof(buf));
 620                 if (len == 0) {
 621                         /* Received EOF.  The remote host has closed the connection. */
 622                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 623                                  host);
 624                         buffer_append(&stderr_buffer, buf, strlen(buf));
 625                         quit_pending = 1;
 626                         return;
 627                 }
 628                 /*
 629                  * There is a kernel bug on Solaris that causes select to
 630                  * sometimes wake up even though there is no data available.
 631                  */
 632                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 633                         len = 0;
 634
 635                 if (len < 0) {
 636                         /* An error has encountered.  Perhaps there is a network problem. */
 637                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 638                                  host, strerror(errno));
 639                         buffer_append(&stderr_buffer, buf, strlen(buf));
 640                         quit_pending = 1;
 641                         return;
 642                 }
 643                 packet_process_incoming(buf, len);
 644         }
 645 }
 646
 647 static void
 648 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 649 {
 650         int id;
 651         Channel *c;
 652
 653         id = packet_get_int();
 654         packet_check_eom();
 655
 656         if ((c = channel_lookup(id)) == NULL) {
 657                 error("%s: no channel for id %d", __func__, id);
 658                 return;
 659         }
 660
 661         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 662                 debug2("Request suceeded on channel %d", id);
 663         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 664                 error("Request failed on channel %d", id);
 665                 channel_free(c);
 666         }
 667 }
 668
 669 static void
 670 client_extra_session2_setup(int id, void *arg)
 671 {
 672         struct confirm_ctx *cctx = arg;
 673         const char *display;
 674         Channel *c;
 675         int i;
 676
 677         if (cctx == NULL)
 678                 fatal("%s: cctx == NULL", __func__);
 679         if ((c = channel_lookup(id)) == NULL)
 680                 fatal("%s: no channel for id %d", __func__, id);
 681
 682         display = getenv("DISPLAY");
 683         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
 684                 char *proto, *data;
 685                 /* Get reasonable local authentication information. */
 686                 client_x11_get_proto(display, options.xauth_location,
 687                     options.forward_x11_trusted, &proto, &data);
 688                 /* Request forwarding with authentication spoofing. */
 689                 debug("Requesting X11 forwarding with authentication spoofing.");
 690                 x11_request_forwarding_with_spoofing(id, display, proto, data);
 691                 /* XXX wait for reply */
 692         }
 693
 694         if (cctx->want_agent_fwd && options.forward_agent) {
 695                 debug("Requesting authentication agent forwarding.");
 696                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
 697                 packet_send();
 698         }
 699
 700         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 701             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
 702             client_subsystem_reply);
 703
 704         c->confirm_ctx = NULL;
 705         buffer_free(&cctx->cmd);
 706         xfree(cctx->term);
 707         if (cctx->env != NULL) {
 708                 for (i = 0; cctx->env[i] != NULL; i++)
 709                         xfree(cctx->env[i]);
 710                 xfree(cctx->env);
 711         }
 712         xfree(cctx);
 713 }
 714
 715 static void
 716 client_process_control(fd_set *readset)
 717 {
 718         Buffer m;
 719         Channel *c;
 720         int client_fd, new_fd[3], ver, allowed, window, packetmax;
 721         socklen_t addrlen;
 722         struct sockaddr_storage addr;
 723         struct confirm_ctx *cctx;
 724         char *cmd;
 725         u_int i, len, env_len, command, flags;
 726         uid_t euid;
 727         gid_t egid;
 728         int listen_port = 0;
 729         int connect_port = 0;
 730         char * listen_host = NULL;
 731         char * connect_host = NULL;
 732
 733         /*
 734          * Accept connection on control socket
 735          */
 736         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 737                 return;
 738
 739         memset(&addr, 0, sizeof(addr));
 740         addrlen = sizeof(addr);
 741         if ((client_fd = accept(control_fd,
 742             (struct sockaddr*)&addr, &addrlen)) == -1) {
 743                 error("%s accept: %s", __func__, strerror(errno));
 744                 return;
 745         }
 746
 747         if (getpeereid(client_fd, &euid, &egid) < 0) {
 748                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 749                 close(client_fd);
 750                 return;
 751         }
 752         if ((euid != 0) && (getuid() != euid)) {
 753                 error("control mode uid mismatch: peer euid %u != uid %u",
 754                     (u_int) euid, (u_int) getuid());
 755                 close(client_fd);
 756                 return;
 757         }
 758
 759         unset_nonblock(client_fd);
 760
 761         /* Read command */
 762         buffer_init(&m);
 763         if (ssh_msg_recv(client_fd, &m) == -1) {
 764                 error("%s: client msg_recv failed", __func__);
 765                 close(client_fd);
 766                 buffer_free(&m);
 767                 return;
 768         }
 769         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 770                 error("%s: wrong client version %d", __func__, ver);
 771                 buffer_free(&m);
 772                 close(client_fd);
 773                 return;
 774         }
 775
 776         allowed = 1;
 777         command = buffer_get_int(&m);
 778         flags = buffer_get_int(&m);
 779
 780         if (SSHMUX_FLAG_PORTFORWARD & flags)
 781         {
 782                 listen_host = buffer_get_string(&m,NULL);
 783                 listen_port = buffer_get_int(&m);
 784                 connect_host = buffer_get_string(&m,NULL);
 785                 connect_port = buffer_get_int(&m);
 786         }
 787         buffer_clear(&m);
 788
 789         switch (command) {
 790         case SSHMUX_COMMAND_OPEN:
 791                 if (options.control_master == SSHCTL_MASTER_ASK ||
 792                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 793                         allowed = ask_permission("Allow shared connection "
 794                             "to %s? ", host);
 795                 /* continue below */
 796                 break;
 797         case SSHMUX_COMMAND_TERMINATE:
 798                 if (options.control_master == SSHCTL_MASTER_ASK ||
 799                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 800                         allowed = ask_permission("Terminate shared connection "
 801                             "to %s? ", host);
 802                 if (allowed)
 803                         quit_pending = 1;
 804                 /* FALLTHROUGH */
 805         case SSHMUX_COMMAND_ALIVE_CHECK:
 806                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 807                 buffer_clear(&m);
 808                 buffer_put_int(&m, allowed);
 809                 buffer_put_int(&m, getpid());
 810                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 811                         error("%s: client msg_send failed", __func__);
 812                         close(client_fd);
 813                         buffer_free(&m);
 814                         return;
 815                 }
 816                 buffer_free(&m);
 817                 close(client_fd);
 818                 return;
 819         default:
 820                 error("Unsupported command %d", command);
 821                 buffer_free(&m);
 822                 close(client_fd);
 823                 return;
 824         }
 825
 826         if (allowed && (SSHMUX_FLAG_PORTFORWARD & flags) && listen_host && connect_host)
 827         {
 828                 int ret;
 829                 Forward * fwd;
 830
 831                 fwd = &options.local_forwards[options.num_local_forwards++];
 832                 fwd->listen_host = xstrdup(listen_host);
 833                 fwd->listen_port = listen_port;
 834                 fwd->connect_host = xstrdup(connect_host);
 835                 fwd->connect_port = connect_port;
 836                 ret = channel_setup_local_fwd_listener(
 837                         options.local_forwards[options.num_local_forwards-1].listen_host,
 838                         options.local_forwards[options.num_local_forwards-1].listen_port,
 839                         options.local_forwards[options.num_local_forwards-1].connect_host,
 840                         options.local_forwards[options.num_local_forwards-1].connect_port,
 841                         options.gateway_ports, options.hpn_disabled, options.hpn_buffer_size);
 842
 843         }
 844
 845
 846         if (listen_host)
 847                 xfree(listen_host);
 848         if (connect_host)
 849                 xfree(connect_host);
 850
 851         /* Reply for SSHMUX_COMMAND_OPEN */
 852         buffer_clear(&m);
 853         buffer_put_int(&m, allowed);
 854         buffer_put_int(&m, getpid());
 855         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 856                 error("%s: client msg_send failed", __func__);
 857                 close(client_fd);
 858                 buffer_free(&m);
 859                 return;
 860         }
 861
 862         if (!allowed) {
 863                 error("Refused control connection");
 864                 close(client_fd);
 865                 buffer_free(&m);
 866                 return;
 867         }
 868
 869         buffer_clear(&m);
 870         if (ssh_msg_recv(client_fd, &m) == -1) {
 871                 error("%s: client msg_recv failed", __func__);
 872                 close(client_fd);
 873                 buffer_free(&m);
 874                 return;
 875         }
 876         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 877                 error("%s: wrong client version %d", __func__, ver);
 878                 buffer_free(&m);
 879                 close(client_fd);
 880                 return;
 881         }
 882
 883         cctx = xcalloc(1, sizeof(*cctx));
 884         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 885         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 886         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 887         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 888         cctx->term = buffer_get_string(&m, &len);
 889
 890         cmd = buffer_get_string(&m, &len);
 891         buffer_init(&cctx->cmd);
 892         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 893
 894         env_len = buffer_get_int(&m);
 895         env_len = MIN(env_len, 4096);
 896         debug3("%s: receiving %d env vars", __func__, env_len);
 897         if (env_len != 0) {
 898                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 899                 for (i = 0; i < env_len; i++)
 900                         cctx->env[i] = buffer_get_string(&m, &len);
 901                 cctx->env[i] = NULL;
 902         }
 903
 904         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 905             cctx->want_tty, cctx->want_subsys, cmd);
 906         xfree(cmd);
 907
 908         /* Gather fds from client */
 909         new_fd[0] = mm_receive_fd(client_fd);
 910         new_fd[1] = mm_receive_fd(client_fd);
 911         new_fd[2] = mm_receive_fd(client_fd);
 912
 913         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 914             new_fd[0], new_fd[1], new_fd[2]);
 915
 916         /* Try to pick up ttymodes from client before it goes raw */
 917         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 918                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 919
 920         /* This roundtrip is just for synchronisation of ttymodes */
 921         buffer_clear(&m);
 922         if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 923                 error("%s: client msg_send failed", __func__);
 924                 close(client_fd);
 925                 close(new_fd[0]);
 926                 close(new_fd[1]);
 927                 close(new_fd[2]);
 928                 buffer_free(&m);
 929                 xfree(cctx->term);
 930                 if (env_len != 0) {
 931                         for (i = 0; i < env_len; i++)
 932                                 xfree(cctx->env[i]);
 933                         xfree(cctx->env);
 934                 }
 935                 return;
 936         }
 937         buffer_free(&m);
 938
 939         /* enable nonblocking unless tty */
 940         if (!isatty(new_fd[0]))
 941                 set_nonblock(new_fd[0]);
 942         if (!isatty(new_fd[1]))
 943                 set_nonblock(new_fd[1]);
 944         if (!isatty(new_fd[2]))
 945                 set_nonblock(new_fd[2]);
 946
 947         set_nonblock(client_fd);
 948
 949         if (options.hpn_disabled)
 950           window = options.hpn_buffer_size;
 951         else
 952           window = CHAN_SES_WINDOW_DEFAULT;
 953         packetmax = CHAN_SES_PACKET_DEFAULT;
 954         if (cctx->want_tty) {
 955                 window >>= 1;
 956                 packetmax >>= 1;
 957         }
 958
 959         c = channel_new("session", SSH_CHANNEL_OPENING,
 960             new_fd[0], new_fd[1], new_fd[2], window, packetmax,
 961             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 962
 963         /* XXX */
 964         c->ctl_fd = client_fd;
 965
 966         debug3("%s: channel_new: %d", __func__, c->self);
 967
 968         channel_send_open(c->self);
 969         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 970 }
 971
 972 static void
 973 process_cmdline(void)
 974 {
 975         void (*handler)(int);
 976         char *s, *cmd, *cancel_host;
 977         int delete = 0;
 978         int local = 0;
 979         u_short cancel_port;
 980         Forward fwd;
 981
 982         leave_raw_mode();
 983         handler = signal(SIGINT, SIG_IGN);
 984         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 985         if (s == NULL)
 986                 goto out;
 987         while (isspace(*s))
 988                 s++;
 989         if (*s == '-')
 990                 s++;    /* Skip cmdline '-', if any */
 991         if (*s == '\0')
 992                 goto out;
 993
 994         if (*s == 'h' || *s == 'H' || *s == '?') {
 995                 logit("Commands:");
 996                 logit("      -L[bind_address:]port:host:hostport    "
 997                     "Request local forward");
 998                 logit("      -R[bind_address:]port:host:hostport    "
 999                     "Request remote forward");
1000                 logit("      -KR[bind_address:]port                 "
1001                     "Cancel remote forward");
1002                 if (!options.permit_local_command)
1003                         goto out;
1004                 logit("      !args                                  "
1005                     "Execute local command");
1006                 goto out;
1007         }
1008
1009         if (*s == '!' && options.permit_local_command) {
1010                 s++;
1011                 ssh_local_cmd(s);
1012                 goto out;
1013         }
1014
1015         if (*s == 'K') {
1016                 delete = 1;
1017                 s++;
1018         }
1019         if (*s != 'L' && *s != 'R') {
1020                 logit("Invalid command.");
1021                 goto out;
1022         }
1023         if (*s == 'L')
1024                 local = 1;
1025         if (local && delete) {
1026                 logit("Not supported.");
1027                 goto out;
1028         }
1029         if ((!local || delete) && !compat20) {
1030                 logit("Not supported for SSH protocol version 1.");
1031                 goto out;
1032         }
1033
1034         while (isspace(*++s))
1035                 ;
1036
1037         if (delete) {
1038                 cancel_port = 0;
1039                 cancel_host = hpdelim(&s);      /* may be NULL */
1040                 if (s != NULL) {
1041                         cancel_port = a2port(s);
1042                         cancel_host = cleanhostname(cancel_host);
1043                 } else {
1044                         cancel_port = a2port(cancel_host);
1045                         cancel_host = NULL;
1046                 }
1047                 if (cancel_port == 0) {
1048                         logit("Bad forwarding close port");
1049                         goto out;
1050                 }
1051                 channel_request_rforward_cancel(cancel_host, cancel_port);
1052         } else {
1053                 if (!parse_forward(&fwd, s)) {
1054                         logit("Bad forwarding specification.");
1055                         goto out;
1056                 }
1057                 if (local) {
1058                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1059                             fwd.listen_port, fwd.connect_host,
1060                             fwd.connect_port, options.gateway_ports,
1061                             options.hpn_disabled, options.hpn_buffer_size) < 0) {
1062                                 logit("Port forwarding failed.");
1063                                 goto out;
1064                         }
1065                 } else {
1066                         if (channel_request_remote_forwarding(fwd.listen_host,
1067                             fwd.listen_port, fwd.connect_host,
1068                             fwd.connect_port) < 0) {
1069                                 logit("Port forwarding failed.");
1070                                 goto out;
1071                         }
1072                 }
1073
1074                 logit("Forwarding port.");
1075         }
1076
1077 out:
1078         signal(SIGINT, handler);
1079         enter_raw_mode();
1080         if (cmd)
1081                 xfree(cmd);
1082 }
1083
1084 /* process the characters one by one */
1085 static int
1086 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1087 {
1088         char string[1024];
1089         pid_t pid;
1090         int bytes = 0;
1091         u_int i;
1092         u_char ch;
1093         char *s;
1094
1095         if (len <= 0)
1096                 return (0);
1097
1098         for (i = 0; i < (u_int)len; i++) {
1099                 /* Get one character at a time. */
1100                 ch = buf[i];
1101
1102                 if (escape_pending) {
1103                         /* We have previously seen an escape character. */
1104                         /* Clear the flag now. */
1105                         escape_pending = 0;
1106
1107                         /* Process the escaped character. */
1108                         switch (ch) {
1109                         case '.':
1110                                 /* Terminate the connection. */
1111                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1112                                 buffer_append(berr, string, strlen(string));
1113
1114                                 quit_pending = 1;
1115                                 return -1;
1116
1117                         case 'Z' - 64:
1118                                 /* Suspend the program. */
1119                                 /* Print a message to that effect to the user. */
1120                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1121                                 buffer_append(berr, string, strlen(string));
1122
1123                                 /* Restore terminal modes and suspend. */
1124                                 client_suspend_self(bin, bout, berr);
1125
1126                                 /* We have been continued. */
1127                                 continue;
1128
1129                         case 'B':
1130                                 if (compat20) {
1131                                         snprintf(string, sizeof string,
1132                                             "%cB\r\n", escape_char);
1133                                         buffer_append(berr, string,
1134                                             strlen(string));
1135                                         channel_request_start(session_ident,
1136                                             "break", 0);
1137                                         packet_put_int(1000);
1138                                         packet_send();
1139                                 }
1140                                 continue;
1141
1142                         case 'R':
1143                                 if (compat20) {
1144                                         if (datafellows & SSH_BUG_NOREKEY)
1145                                                 logit("Server does not support re-keying");
1146                                         else
1147                                                 need_rekeying = 1;
1148                                 }
1149                                 continue;
1150
1151                         case '&':
1152                                 /*
1153                                  * Detach the program (continue to serve connections,
1154                                  * but put in background and no more new connections).
1155                                  */
1156                                 /* Restore tty modes. */
1157                                 leave_raw_mode();
1158
1159                                 /* Stop listening for new connections. */
1160                                 channel_stop_listening();
1161
1162                                 snprintf(string, sizeof string,
1163                                     "%c& [backgrounded]\n", escape_char);
1164                                 buffer_append(berr, string, strlen(string));
1165
1166                                 /* Fork into background. */
1167                                 pid = fork();
1168                                 if (pid < 0) {
1169                                         error("fork: %.100s", strerror(errno));
1170                                         continue;
1171                                 }
1172                                 if (pid != 0) { /* This is the parent. */
1173                                         /* The parent just exits. */
1174                                         exit(0);
1175                                 }
1176                                 /* The child continues serving connections. */
1177                                 if (compat20) {
1178                                         buffer_append(bin, "\004", 1);
1179                                         /* fake EOF on stdin */
1180                                         return -1;
1181                                 } else if (!stdin_eof) {
1182                                         /*
1183                                          * Sending SSH_CMSG_EOF alone does not always appear
1184                                          * to be enough.  So we try to send an EOF character
1185                                          * first.
1186                                          */
1187                                         packet_start(SSH_CMSG_STDIN_DATA);
1188                                         packet_put_string("\004", 1);
1189                                         packet_send();
1190                                         /* Close stdin. */
1191                                         stdin_eof = 1;
1192                                         if (buffer_len(bin) == 0) {
1193                                                 packet_start(SSH_CMSG_EOF);
1194                                                 packet_send();
1195                                         }
1196                                 }
1197                                 continue;
1198
1199                         case '?':
1200                                 snprintf(string, sizeof string,
1201 "%c?\r\n\
1202 Supported escape sequences:\r\n\
1203 %c.  - terminate connection\r\n\
1204 %cB  - send a BREAK to the remote system\r\n\
1205 %cC  - open a command line\r\n\
1206 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1207 %c^Z - suspend ssh\r\n\
1208 %c#  - list forwarded connections\r\n\
1209 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1210 %c?  - this message\r\n\
1211 %c%c  - send the escape character by typing it twice\r\n\
1212 (Note that escapes are only recognized immediately after newline.)\r\n",
1213                                     escape_char, escape_char, escape_char, escape_char,
1214                                     escape_char, escape_char, escape_char, escape_char,
1215                                     escape_char, escape_char, escape_char);
1216                                 buffer_append(berr, string, strlen(string));
1217                                 continue;
1218
1219                         case '#':
1220                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1221                                 buffer_append(berr, string, strlen(string));
1222                                 s = channel_open_message();
1223                                 buffer_append(berr, s, strlen(s));
1224                                 xfree(s);
1225                                 continue;
1226
1227                         case 'C':
1228                                 process_cmdline();
1229                                 continue;
1230
1231                         default:
1232                                 if (ch != escape_char) {
1233                                         buffer_put_char(bin, escape_char);
1234                                         bytes++;
1235                                 }
1236                                 /* Escaped characters fall through here */
1237                                 break;
1238                         }
1239                 } else {
1240                         /*
1241                          * The previous character was not an escape char. Check if this
1242                          * is an escape.
1243                          */
1244                         if (last_was_cr && ch == escape_char) {
1245                                 /* It is. Set the flag and continue to next character. */
1246                                 escape_pending = 1;
1247                                 continue;
1248                         }
1249                 }
1250
1251                 /*
1252                  * Normal character.  Record whether it was a newline,
1253                  * and append it to the buffer.
1254                  */
1255                 last_was_cr = (ch == '\r' || ch == '\n');
1256                 buffer_put_char(bin, ch);
1257                 bytes++;
1258         }
1259         return bytes;
1260 }
1261
1262 static void
1263 client_process_input(fd_set *readset)
1264 {
1265         int len;
1266         char buf[8192];
1267
1268         /* Read input from stdin. */
1269         if (FD_ISSET(fileno(stdin), readset)) {
1270                 /* Read as much as possible. */
1271                 len = read(fileno(stdin), buf, sizeof(buf));
1272                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1273                         return;         /* we'll try again later */
1274                 if (len <= 0) {
1275                         /*
1276                          * Received EOF or error.  They are treated
1277                          * similarly, except that an error message is printed
1278                          * if it was an error condition.
1279                          */
1280                         if (len < 0) {
1281                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1282                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1283                         }
1284                         /* Mark that we have seen EOF. */
1285                         stdin_eof = 1;
1286                         /*
1287                          * Send an EOF message to the server unless there is
1288                          * data in the buffer.  If there is data in the
1289                          * buffer, no message will be sent now.  Code
1290                          * elsewhere will send the EOF when the buffer
1291                          * becomes empty if stdin_eof is set.
1292                          */
1293                         if (buffer_len(&stdin_buffer) == 0) {
1294                                 packet_start(SSH_CMSG_EOF);
1295                                 packet_send();
1296                         }
1297                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1298                         /*
1299                          * Normal successful read, and no escape character.
1300                          * Just append the data to buffer.
1301                          */
1302                         buffer_append(&stdin_buffer, buf, len);
1303                 } else {
1304                         /*
1305                          * Normal, successful read.  But we have an escape character
1306                          * and have to process the characters one by one.
1307                          */
1308                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1309                             &stderr_buffer, buf, len) == -1)
1310                                 return;
1311                 }
1312         }
1313 }
1314
1315 static void
1316 client_process_output(fd_set *writeset)
1317 {
1318         int len;
1319         char buf[100];
1320
1321         /* Write buffered output to stdout. */
1322         if (FD_ISSET(fileno(stdout), writeset)) {
1323                 /* Write as much data as possible. */
1324                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1325                     buffer_len(&stdout_buffer));
1326                 if (len <= 0) {
1327                         if (errno == EINTR || errno == EAGAIN)
1328                                 len = 0;
1329                         else {
1330                                 /*
1331                                  * An error or EOF was encountered.  Put an
1332                                  * error message to stderr buffer.
1333                                  */
1334                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1335                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1336                                 quit_pending = 1;
1337                                 return;
1338                         }
1339                 }
1340                 /* Consume printed data from the buffer. */
1341                 buffer_consume(&stdout_buffer, len);
1342                 stdout_bytes += len;
1343         }
1344         /* Write buffered output to stderr. */
1345         if (FD_ISSET(fileno(stderr), writeset)) {
1346                 /* Write as much data as possible. */
1347                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1348                     buffer_len(&stderr_buffer));
1349                 if (len <= 0) {
1350                         if (errno == EINTR || errno == EAGAIN)
1351                                 len = 0;
1352                         else {
1353                                 /* EOF or error, but can't even print error message. */
1354                                 quit_pending = 1;
1355                                 return;
1356                         }
1357                 }
1358                 /* Consume printed characters from the buffer. */
1359                 buffer_consume(&stderr_buffer, len);
1360                 stderr_bytes += len;
1361         }
1362 }
1363
1364 /*
1365  * Get packets from the connection input buffer, and process them as long as
1366  * there are packets available.
1367  *
1368  * Any unknown packets received during the actual
1369  * session cause the session to terminate.  This is
1370  * intended to make debugging easier since no
1371  * confirmations are sent.  Any compatible protocol
1372  * extensions must be negotiated during the
1373  * preparatory phase.
1374  */
1375
1376 static void
1377 client_process_buffered_input_packets(void)
1378 {
1379         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1380 }
1381
1382 /* scan buf[] for '~' before sending data to the peer */
1383
1384 static int
1385 simple_escape_filter(Channel *c, char *buf, int len)
1386 {
1387         /* XXX we assume c->extended is writeable */
1388         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1389 }
1390
1391 static void
1392 client_channel_closed(int id, void *arg)
1393 {
1394         channel_cancel_cleanup(id);
1395         session_closed = 1;
1396         leave_raw_mode();
1397 }
1398
1399 /*
1400  * Implements the interactive session with the server.  This is called after
1401  * the user has been authenticated, and a command has been started on the
1402  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1403  * used as an escape character for terminating or suspending the session.
1404  */
1405
1406 int
1407 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1408 {
1409         fd_set *readset = NULL, *writeset = NULL;
1410         double start_time, total_time;
1411         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1412         u_int nalloc = 0;
1413         char buf[100];
1414
1415         debug("Entering interactive session.");
1416
1417         start_time = get_current_time();
1418
1419         /* Initialize variables. */
1420         escape_pending = 0;
1421         last_was_cr = 1;
1422         exit_status = -1;
1423         stdin_eof = 0;
1424         buffer_high = 64 * 1024;
1425         connection_in = packet_get_connection_in();
1426         connection_out = packet_get_connection_out();
1427         max_fd = MAX(connection_in, connection_out);
1428         if (control_fd != -1)
1429                 max_fd = MAX(max_fd, control_fd);
1430
1431         if (!compat20) {
1432                 /* enable nonblocking unless tty */
1433                 if (!isatty(fileno(stdin)))
1434                         set_nonblock(fileno(stdin));
1435                 if (!isatty(fileno(stdout)))
1436                         set_nonblock(fileno(stdout));
1437                 if (!isatty(fileno(stderr)))
1438                         set_nonblock(fileno(stderr));
1439                 max_fd = MAX(max_fd, fileno(stdin));
1440                 max_fd = MAX(max_fd, fileno(stdout));
1441                 max_fd = MAX(max_fd, fileno(stderr));
1442         }
1443         stdin_bytes = 0;
1444         stdout_bytes = 0;
1445         stderr_bytes = 0;
1446         quit_pending = 0;
1447         escape_char = escape_char_arg;
1448
1449         /* Initialize buffers. */
1450         buffer_init(&stdin_buffer);
1451         buffer_init(&stdout_buffer);
1452         buffer_init(&stderr_buffer);
1453
1454         client_init_dispatch();
1455
1456         /*
1457          * Set signal handlers, (e.g. to restore non-blocking mode)
1458          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1459          */
1460         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1461                 signal(SIGHUP, signal_handler);
1462         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1463                 signal(SIGINT, signal_handler);
1464         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1465                 signal(SIGQUIT, signal_handler);
1466         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1467                 signal(SIGTERM, signal_handler);
1468         signal(SIGWINCH, window_change_handler);
1469
1470         if (have_pty)
1471                 enter_raw_mode();
1472
1473         if (compat20) {
1474                 session_ident = ssh2_chan_id;
1475                 if (escape_char != SSH_ESCAPECHAR_NONE)
1476                         channel_register_filter(session_ident,
1477                             simple_escape_filter, NULL);
1478                 if (session_ident != -1)
1479                         channel_register_cleanup(session_ident,
1480                             client_channel_closed, 0);
1481         } else {
1482                 /* Check if we should immediately send eof on stdin. */
1483                 client_check_initial_eof_on_stdin();
1484         }
1485
1486         /* Main loop of the client for the interactive session mode. */
1487         while (!quit_pending) {
1488
1489                 /* Process buffered packets sent by the server. */
1490                 client_process_buffered_input_packets();
1491
1492                 if (compat20 && session_closed && !channel_still_open())
1493                         break;
1494
1495                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1496
1497                 if (rekeying) {
1498                         debug("rekeying in progress");
1499                 } else {
1500                         /*
1501                          * Make packets of buffered stdin data, and buffer
1502                          * them for sending to the server.
1503                          */
1504                         if (!compat20)
1505                                 client_make_packets_from_stdin_data();
1506
1507                         /*
1508                          * Make packets from buffered channel data, and
1509                          * enqueue them for sending to the server.
1510                          */
1511                         if (packet_not_very_much_data_to_write())
1512                                 channel_output_poll();
1513
1514                         /*
1515                          * Check if the window size has changed, and buffer a
1516                          * message about it to the server if so.
1517                          */
1518                         client_check_window_change();
1519
1520                         if (quit_pending)
1521                                 break;
1522                 }
1523                 /*
1524                  * Wait until we have something to do (something becomes
1525                  * available on one of the descriptors).
1526                  */
1527                 max_fd2 = max_fd;
1528                 client_wait_until_can_do_something(&readset, &writeset,
1529                     &max_fd2, &nalloc, rekeying);
1530
1531                 if (quit_pending)
1532                         break;
1533
1534                 /* Do channel operations unless rekeying in progress. */
1535                 if (!rekeying) {
1536                         channel_after_select(readset, writeset);
1537                         if (need_rekeying || packet_need_rekeying()) {
1538                                 debug("need rekeying");
1539                                 xxx_kex->done = 0;
1540                                 kex_send_kexinit(xxx_kex);
1541                                 need_rekeying = 0;
1542                         }
1543                 }
1544
1545                 /* Buffer input from the connection.  */
1546                 client_process_net_input(readset);
1547
1548                 /* Accept control connections.  */
1549                 client_process_control(readset);
1550
1551                 if (quit_pending)
1552                         break;
1553
1554                 if (!compat20) {
1555                         /* Buffer data from stdin */
1556                         client_process_input(readset);
1557                         /*
1558                          * Process output to stdout and stderr.  Output to
1559                          * the connection is processed elsewhere (above).
1560                          */
1561                         client_process_output(writeset);
1562                 }
1563
1564                 /* Send as much buffered packet data as possible to the sender. */
1565                 if (FD_ISSET(connection_out, writeset))
1566                         packet_write_poll();
1567         }
1568         if (readset)
1569                 xfree(readset);
1570         if (writeset)
1571                 xfree(writeset);
1572
1573         /* Terminate the session. */
1574
1575         /* Stop watching for window change. */
1576         signal(SIGWINCH, SIG_DFL);
1577
1578         channel_free_all();
1579
1580         if (have_pty)
1581                 leave_raw_mode();
1582
1583         /* restore blocking io */
1584         if (!isatty(fileno(stdin)))
1585                 unset_nonblock(fileno(stdin));
1586         if (!isatty(fileno(stdout)))
1587                 unset_nonblock(fileno(stdout));
1588         if (!isatty(fileno(stderr)))
1589                 unset_nonblock(fileno(stderr));
1590
1591         /*
1592          * If there was no shell or command requested, there will be no remote
1593          * exit status to be returned.  In that case, clear error code if the
1594          * connection was deliberately terminated at this end.
1595          */
1596         if (no_shell_flag && received_signal == SIGTERM) {
1597                 received_signal = 0;
1598                 exit_status = 0;
1599         }
1600
1601         if (received_signal)
1602                 fatal("Killed by signal %d.", (int) received_signal);
1603
1604         /*
1605          * In interactive mode (with pseudo tty) display a message indicating
1606          * that the connection has been closed.
1607          */
1608         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1609                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1610                 buffer_append(&stderr_buffer, buf, strlen(buf));
1611         }
1612
1613         /* Output any buffered data for stdout. */
1614         while (buffer_len(&stdout_buffer) > 0) {
1615                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1616                     buffer_len(&stdout_buffer));
1617                 if (len <= 0) {
1618                         error("Write failed flushing stdout buffer.");
1619                         break;
1620                 }
1621                 buffer_consume(&stdout_buffer, len);
1622                 stdout_bytes += len;
1623         }
1624
1625         /* Output any buffered data for stderr. */
1626         while (buffer_len(&stderr_buffer) > 0) {
1627                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1628                     buffer_len(&stderr_buffer));
1629                 if (len <= 0) {
1630                         error("Write failed flushing stderr buffer.");
1631                         break;
1632                 }
1633                 buffer_consume(&stderr_buffer, len);
1634                 stderr_bytes += len;
1635         }
1636
1637         /* Clear and free any buffers. */
1638         memset(buf, 0, sizeof(buf));
1639         buffer_free(&stdin_buffer);
1640         buffer_free(&stdout_buffer);
1641         buffer_free(&stderr_buffer);
1642
1643         /* Report bytes transferred, and transfer rates. */
1644         total_time = get_current_time() - start_time;
1645         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1646             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1647         if (total_time > 0)
1648                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1649                     stdin_bytes / total_time, stdout_bytes / total_time,
1650                     stderr_bytes / total_time);
1651
1652         /* Return the exit status of the program. */
1653         debug("Exit status %d", exit_status);
1654         return exit_status;
1655 }
1656
1657 /*********/
1658
1659 static void
1660 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1661 {
1662         u_int data_len;
1663         char *data = packet_get_string(&data_len);
1664         packet_check_eom();
1665         buffer_append(&stdout_buffer, data, data_len);
1666         memset(data, 0, data_len);
1667         xfree(data);
1668 }
1669 static void
1670 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1671 {
1672         u_int data_len;
1673         char *data = packet_get_string(&data_len);
1674         packet_check_eom();
1675         buffer_append(&stderr_buffer, data, data_len);
1676         memset(data, 0, data_len);
1677         xfree(data);
1678 }
1679 static void
1680 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1681 {
1682         exit_status = packet_get_int();
1683         packet_check_eom();
1684         /* Acknowledge the exit. */
1685         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1686         packet_send();
1687         /*
1688          * Must wait for packet to be sent since we are
1689          * exiting the loop.
1690          */
1691         packet_write_wait();
1692         /* Flag that we want to exit. */
1693         quit_pending = 1;
1694 }
1695 static void
1696 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1697 {
1698         Channel *c = NULL;
1699         int remote_id, sock;
1700
1701         /* Read the remote channel number from the message. */
1702         remote_id = packet_get_int();
1703         packet_check_eom();
1704
1705         /*
1706          * Get a connection to the local authentication agent (this may again
1707          * get forwarded).
1708          */
1709         sock = ssh_get_authentication_socket();
1710
1711         /*
1712          * If we could not connect the agent, send an error message back to
1713          * the server. This should never happen unless the agent dies,
1714          * because authentication forwarding is only enabled if we have an
1715          * agent.
1716          */
1717         if (sock >= 0) {
1718                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1719                     -1, 0, 0, 0, "authentication agent connection", 1);
1720                 c->remote_id = remote_id;
1721                 c->force_drain = 1;
1722         }
1723         if (c == NULL) {
1724                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1725                 packet_put_int(remote_id);
1726         } else {
1727                 /* Send a confirmation to the remote host. */
1728                 debug("Forwarding authentication connection.");
1729                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1730                 packet_put_int(remote_id);
1731                 packet_put_int(c->self);
1732         }
1733         packet_send();
1734 }
1735
1736 static Channel *
1737 client_request_forwarded_tcpip(const char *request_type, int rchan)
1738 {
1739         Channel *c = NULL;
1740         char *listen_address, *originator_address;
1741         int listen_port, originator_port;
1742         int sock;
1743
1744         /* Get rest of the packet */
1745         listen_address = packet_get_string(NULL);
1746         listen_port = packet_get_int();
1747         originator_address = packet_get_string(NULL);
1748         originator_port = packet_get_int();
1749         packet_check_eom();
1750
1751         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1752             listen_address, listen_port, originator_address, originator_port);
1753
1754         sock = channel_connect_by_listen_address(listen_port);
1755         if (sock < 0) {
1756                 xfree(originator_address);
1757                 xfree(listen_address);
1758                 return NULL;
1759         }
1760         if (options.hpn_disabled)
1761                 c = channel_new("forwarded-tcpip",
1762                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1763                     CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1764                     originator_address, 1);
1765         else
1766                 c = channel_new("forwarded-tcpip",
1767                     SSH_CHANNEL_CONNECTING, sock, sock, -1,
1768                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1769                     originator_address, 1);
1770         xfree(originator_address);
1771         xfree(listen_address);
1772         return c;
1773 }
1774
1775 static Channel *
1776 client_request_x11(const char *request_type, int rchan)
1777 {
1778         Channel *c = NULL;
1779         char *originator;
1780         int originator_port;
1781         int sock;
1782
1783         if (!options.forward_x11) {
1784                 error("Warning: ssh server tried X11 forwarding.");
1785                 error("Warning: this is probably a break-in attempt by a malicious server.");
1786                 return NULL;
1787         }
1788         originator = packet_get_string(NULL);
1789         if (datafellows & SSH_BUG_X11FWD) {
1790                 debug2("buggy server: x11 request w/o originator_port");
1791                 originator_port = 0;
1792         } else {
1793                 originator_port = packet_get_int();
1794         }
1795         packet_check_eom();
1796         /* XXX check permission */
1797         debug("client_request_x11: request from %s %d", originator,
1798             originator_port);
1799         xfree(originator);
1800         sock = x11_connect_display();
1801         if (sock < 0)
1802                 return NULL;
1803         if (options.hpn_disabled)
1804                 c = channel_new("x11",
1805                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1806                     CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1807         else
1808                 c = channel_new("x11",
1809                     SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1810                     options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1811         c->force_drain = 1;
1812         return c;
1813 }
1814
1815 static Channel *
1816 client_request_agent(const char *request_type, int rchan)
1817 {
1818         Channel *c = NULL;
1819         int sock;
1820
1821         if (!options.forward_agent) {
1822                 error("Warning: ssh server tried agent forwarding.");
1823                 error("Warning: this is probably a break-in attempt by a malicious server.");
1824                 return NULL;
1825         }
1826         sock = ssh_get_authentication_socket();
1827         if (sock < 0)
1828                 return NULL;
1829         if (options.hpn_disabled)
1830                 c = channel_new("authentication agent connection",
1831                     SSH_CHANNEL_OPEN, sock, sock, -1,
1832                     CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1833                     "authentication agent connection", 1);
1834         else
1835                 c = channel_new("authentication agent connection",
1836                     SSH_CHANNEL_OPEN, sock, sock, -1,
1837                     options.hpn_buffer_size, options.hpn_buffer_size, 0,
1838                     "authentication agent connection", 1);
1839         c->force_drain = 1;
1840         return c;
1841 }
1842
1843 int
1844 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1845 {
1846         Channel *c;
1847         int fd;
1848
1849         if (tun_mode == SSH_TUNMODE_NO)
1850                 return 0;
1851
1852         if (!compat20) {
1853                 error("Tunnel forwarding is not support for protocol 1");
1854                 return -1;
1855         }
1856
1857         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1858
1859         /* Open local tunnel device */
1860         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1861                 error("Tunnel device open failed.");
1862                 return -1;
1863         }
1864
1865         if(options.hpn_disabled)
1866                 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1867                                 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1868                                 0, "tun", 1);
1869         else
1870                 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1871                                 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
1872                                 0, "tun", 1);
1873         c->datagram = 1;
1874
1875 #if defined(SSH_TUN_FILTER)
1876         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1877                 channel_register_filter(c->self, sys_tun_infilter,
1878                     sys_tun_outfilter);
1879 #endif
1880
1881         packet_start(SSH2_MSG_CHANNEL_OPEN);
1882         packet_put_cstring("tun@openssh.com");
1883         packet_put_int(c->self);
1884         packet_put_int(c->local_window_max);
1885         packet_put_int(c->local_maxpacket);
1886         packet_put_int(tun_mode);
1887         packet_put_int(remote_tun);
1888         packet_send();
1889
1890         return 0;
1891 }
1892
1893 /* XXXX move to generic input handler */
1894 static void
1895 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1896 {
1897         Channel *c = NULL;
1898         char *ctype;
1899         int rchan;
1900         u_int rmaxpack, rwindow, len;
1901
1902         ctype = packet_get_string(&len);
1903         rchan = packet_get_int();
1904         rwindow = packet_get_int();
1905         rmaxpack = packet_get_int();
1906
1907         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1908             ctype, rchan, rwindow, rmaxpack);
1909
1910         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1911                 c = client_request_forwarded_tcpip(ctype, rchan);
1912         } else if (strcmp(ctype, "x11") == 0) {
1913                 c = client_request_x11(ctype, rchan);
1914         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1915                 c = client_request_agent(ctype, rchan);
1916         }
1917 /* XXX duplicate : */
1918         if (c != NULL) {
1919                 debug("confirm %s", ctype);
1920                 c->remote_id = rchan;
1921                 c->remote_window = rwindow;
1922                 c->remote_maxpacket = rmaxpack;
1923                 if (c->type != SSH_CHANNEL_CONNECTING) {
1924                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1925                         packet_put_int(c->remote_id);
1926                         packet_put_int(c->self);
1927                         packet_put_int(c->local_window);
1928                         packet_put_int(c->local_maxpacket);
1929                         packet_send();
1930                 }
1931         } else {
1932                 debug("failure %s", ctype);
1933                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1934                 packet_put_int(rchan);
1935                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1936                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1937                         packet_put_cstring("open failed");
1938                         packet_put_cstring("");
1939                 }
1940                 packet_send();
1941         }
1942         xfree(ctype);
1943 }
1944 static void
1945 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1946 {
1947         Channel *c = NULL;
1948         int exitval, id, reply, success = 0;
1949         char *rtype;
1950
1951         id = packet_get_int();
1952         rtype = packet_get_string(NULL);
1953         reply = packet_get_char();
1954
1955         debug("client_input_channel_req: channel %d rtype %s reply %d",
1956             id, rtype, reply);
1957
1958         if (id == -1) {
1959                 error("client_input_channel_req: request for channel -1");
1960         } else if ((c = channel_lookup(id)) == NULL) {
1961                 error("client_input_channel_req: channel %d: unknown channel", id);
1962         } else if (strcmp(rtype, "exit-status") == 0) {
1963                 exitval = packet_get_int();
1964                 if (id == session_ident) {
1965                         success = 1;
1966                         exit_status = exitval;
1967                 } else if (c->ctl_fd == -1) {
1968                         error("client_input_channel_req: unexpected channel %d",
1969                             session_ident);
1970                 } else {
1971                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1972                         success = 1;
1973                 }
1974                 packet_check_eom();
1975         }
1976         if (reply) {
1977                 packet_start(success ?
1978                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1979                 packet_put_int(id);
1980                 packet_send();
1981         }
1982         xfree(rtype);
1983 }
1984 static void
1985 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1986 {
1987         char *rtype;
1988         int want_reply;
1989         int success = 0;
1990
1991         rtype = packet_get_string(NULL);
1992         want_reply = packet_get_char();
1993         debug("client_input_global_request: rtype %s want_reply %d",
1994             rtype, want_reply);
1995         if (want_reply) {
1996                 packet_start(success ?
1997                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1998                 packet_send();
1999                 packet_write_wait();
2000         }
2001         xfree(rtype);
2002 }
2003
2004 void
2005 client_session2_setup(int id, int want_tty, int want_subsystem,
2006     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
2007     dispatch_fn *subsys_repl)
2008 {
2009         int len;
2010         Channel *c = NULL;
2011
2012         debug2("%s: id %d", __func__, id);
2013
2014         if ((c = channel_lookup(id)) == NULL)
2015                 fatal("client_session2_setup: channel %d: unknown channel", id);
2016
2017         if (want_tty) {
2018                 struct winsize ws;
2019                 struct termios tio;
2020
2021                 /* Store window size in the packet. */
2022                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
2023                         memset(&ws, 0, sizeof(ws));
2024
2025                 channel_request_start(id, "pty-req", 0);
2026                 packet_put_cstring(term != NULL ? term : "");
2027                 packet_put_int((u_int)ws.ws_col);
2028                 packet_put_int((u_int)ws.ws_row);
2029                 packet_put_int((u_int)ws.ws_xpixel);
2030                 packet_put_int((u_int)ws.ws_ypixel);
2031                 tio = get_saved_tio();
2032                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
2033                 packet_send();
2034                 /* XXX wait for reply */
2035                 c->client_tty = 1;
2036         }
2037
2038         /* Transfer any environment variables from client to server */
2039         if (options.num_send_env != 0 && env != NULL) {
2040                 int i, j, matched;
2041                 char *name, *val;
2042
2043                 debug("Sending environment.");
2044                 for (i = 0; env[i] != NULL; i++) {
2045                         /* Split */
2046                         name = xstrdup(env[i]);
2047                         if ((val = strchr(name, '=')) == NULL) {
2048                                 xfree(name);
2049                                 continue;
2050                         }
2051                         *val++ = '\0';
2052
2053                         matched = 0;
2054                         for (j = 0; j < options.num_send_env; j++) {
2055                                 if (match_pattern(name, options.send_env[j])) {
2056                                         matched = 1;
2057                                         break;
2058                                 }
2059                         }
2060                         if (!matched) {
2061                                 debug3("Ignored env %s", name);
2062                                 xfree(name);
2063                                 continue;
2064                         }
2065
2066                         debug("Sending env %s = %s", name, val);
2067                         channel_request_start(id, "env", 0);
2068                         packet_put_cstring(name);
2069                         packet_put_cstring(val);
2070                         packet_send();
2071                         xfree(name);
2072                 }
2073         }
2074
2075         len = buffer_len(cmd);
2076         if (len > 0) {
2077                 if (len > 900)
2078                         len = 900;
2079                 if (want_subsystem) {
2080                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
2081                         channel_request_start(id, "subsystem", subsys_repl != NULL);
2082                         if (subsys_repl != NULL) {
2083                                 /* register callback for reply */
2084                                 /* XXX we assume that client_loop has already been called */
2085                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
2086                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
2087                         }
2088                 } else {
2089                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
2090                         channel_request_start(id, "exec", 0);
2091                 }
2092                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2093                 packet_send();
2094         } else {
2095                 channel_request_start(id, "shell", 0);
2096                 packet_send();
2097         }
2098 }
2099
2100 static void
2101 client_init_dispatch_20(void)
2102 {
2103         dispatch_init(&dispatch_protocol_error);
2104
2105         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2106         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2107         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2108         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2109         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2110         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2111         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2112         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2113         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2114         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2115
2116         /* rekeying */
2117         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2118
2119         /* global request reply messages */
2120         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2121         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2122 }
2123 static void
2124 client_init_dispatch_13(void)
2125 {
2126         dispatch_init(NULL);
2127         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2128         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2129         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2130         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2131         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2132         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2133         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2134         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2135         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2136
2137         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2138             &client_input_agent_open : &deny_input_open);
2139         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2140             &x11_input_open : &deny_input_open);
2141 }
2142 static void
2143 client_init_dispatch_15(void)
2144 {
2145         client_init_dispatch_13();
2146         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2147         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2148 }
2149 static void
2150 client_init_dispatch(void)
2151 {
2152         if (compat20)
2153                 client_init_dispatch_20();
2154         else if (compat13)
2155                 client_init_dispatch_13();
2156         else
2157                 client_init_dispatch_15();
2158 }
2159
2160 /* client specific fatal cleanup */
2161 void
2162 cleanup_exit(int i)
2163 {
2164         leave_raw_mode();
2165         leave_non_blocking();
2166         if (options.control_path != NULL && control_fd != -1)
2167                 unlink(options.control_path);
2168         _exit(i);
2169 }