crypto/openssh-4/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
 729         /*
 730          * Accept connection on control socket
 731          */
 732         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 733                 return;
 734
 735         memset(&addr, 0, sizeof(addr));
 736         addrlen = sizeof(addr);
 737         if ((client_fd = accept(control_fd,
 738             (struct sockaddr*)&addr, &addrlen)) == -1) {
 739                 error("%s accept: %s", __func__, strerror(errno));
 740                 return;
 741         }
 742
 743         if (getpeereid(client_fd, &euid, &egid) < 0) {
 744                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 745                 close(client_fd);
 746                 return;
 747         }
 748         if ((euid != 0) && (getuid() != euid)) {
 749                 error("control mode uid mismatch: peer euid %u != uid %u",
 750                     (u_int) euid, (u_int) getuid());
 751                 close(client_fd);
 752                 return;
 753         }
 754
 755         unset_nonblock(client_fd);
 756
 757         /* Read command */
 758         buffer_init(&m);
 759         if (ssh_msg_recv(client_fd, &m) == -1) {
 760                 error("%s: client msg_recv failed", __func__);
 761                 close(client_fd);
 762                 buffer_free(&m);
 763                 return;
 764         }
 765         if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
 766                 error("%s: wrong client version %d", __func__, ver);
 767                 buffer_free(&m);
 768                 close(client_fd);
 769                 return;
 770         }
 771
 772         allowed = 1;
 773         command = buffer_get_int(&m);
 774         flags = buffer_get_int(&m);
 775
 776         buffer_clear(&m);
 777
 778         switch (command) {
 779         case SSHMUX_COMMAND_OPEN:
 780                 if (options.control_master == SSHCTL_MASTER_ASK ||
 781                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 782                         allowed = ask_permission("Allow shared connection "
 783                             "to %s? ", host);
 784                 /* continue below */
 785                 break;
 786         case SSHMUX_COMMAND_TERMINATE:
 787                 if (options.control_master == SSHCTL_MASTER_ASK ||
 788                     options.control_master == SSHCTL_MASTER_AUTO_ASK)
 789                         allowed = ask_permission("Terminate shared connection "
 790                             "to %s? ", host);
 791                 if (allowed)
 792                         quit_pending = 1;
 793                 /* FALLTHROUGH */
 794         case SSHMUX_COMMAND_ALIVE_CHECK:
 795                 /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
 796                 buffer_clear(&m);
 797                 buffer_put_int(&m, allowed);
 798                 buffer_put_int(&m, getpid());
 799                 if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
 800                         error("%s: client msg_send failed", __func__);
 801                         close(client_fd);
 802                         buffer_free(&m);
 803                         return;
 804                 }
 805                 buffer_free(&m);
 806                 close(client_fd);
 807                 return;
 808         default:
 809                 error("Unsupported command %d", command);
 810                 buffer_free(&m);
 811                 close(client_fd);
 812                 return;
 813         }
 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 = xcalloc(1, sizeof(*cctx));
 848         cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
 849         cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
 850         cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
 851         cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
 852         cctx->term = buffer_get_string(&m, &len);
 853
 854         cmd = buffer_get_string(&m, &len);
 855         buffer_init(&cctx->cmd);
 856         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 857
 858         env_len = buffer_get_int(&m);
 859         env_len = MIN(env_len, 4096);
 860         debug3("%s: receiving %d env vars", __func__, env_len);
 861         if (env_len != 0) {
 862                 cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
 863                 for (i = 0; i < env_len; i++)
 864                         cctx->env[i] = buffer_get_string(&m, &len);
 865                 cctx->env[i] = NULL;
 866         }
 867
 868         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 869             cctx->want_tty, cctx->want_subsys, cmd);
 870         xfree(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         window = CHAN_SES_WINDOW_DEFAULT;
 914         packetmax = CHAN_SES_PACKET_DEFAULT;
 915         if (cctx->want_tty) {
 916                 window >>= 1;
 917                 packetmax >>= 1;
 918         }
 919
 920         c = channel_new("session", SSH_CHANNEL_OPENING,
 921             new_fd[0], new_fd[1], new_fd[2], window, packetmax,
 922             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 923
 924         /* XXX */
 925         c->ctl_fd = client_fd;
 926
 927         debug3("%s: channel_new: %d", __func__, c->self);
 928
 929         channel_send_open(c->self);
 930         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 931 }
 932
 933 static void
 934 process_cmdline(void)
 935 {
 936         void (*handler)(int);
 937         char *s, *cmd, *cancel_host;
 938         int delete = 0;
 939         int local = 0;
 940         u_short cancel_port;
 941         Forward fwd;
 942
 943         leave_raw_mode();
 944         handler = signal(SIGINT, SIG_IGN);
 945         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 946         if (s == NULL)
 947                 goto out;
 948         while (isspace(*s))
 949                 s++;
 950         if (*s == '-')
 951                 s++;    /* Skip cmdline '-', if any */
 952         if (*s == '\0')
 953                 goto out;
 954
 955         if (*s == 'h' || *s == 'H' || *s == '?') {
 956                 logit("Commands:");
 957                 logit("      -L[bind_address:]port:host:hostport    "
 958                     "Request local forward");
 959                 logit("      -R[bind_address:]port:host:hostport    "
 960                     "Request remote forward");
 961                 logit("      -KR[bind_address:]port                 "
 962                     "Cancel remote forward");
 963                 if (!options.permit_local_command)
 964                         goto out;
 965                 logit("      !args                                  "
 966                     "Execute local command");
 967                 goto out;
 968         }
 969
 970         if (*s == '!' && options.permit_local_command) {
 971                 s++;
 972                 ssh_local_cmd(s);
 973                 goto out;
 974         }
 975
 976         if (*s == 'K') {
 977                 delete = 1;
 978                 s++;
 979         }
 980         if (*s != 'L' && *s != 'R') {
 981                 logit("Invalid command.");
 982                 goto out;
 983         }
 984         if (*s == 'L')
 985                 local = 1;
 986         if (local && delete) {
 987                 logit("Not supported.");
 988                 goto out;
 989         }
 990         if ((!local || delete) && !compat20) {
 991                 logit("Not supported for SSH protocol version 1.");
 992                 goto out;
 993         }
 994
 995         while (isspace(*++s))
 996                 ;
 997
 998         if (delete) {
 999                 cancel_port = 0;
1000                 cancel_host = hpdelim(&s);      /* may be NULL */
1001                 if (s != NULL) {
1002                         cancel_port = a2port(s);
1003                         cancel_host = cleanhostname(cancel_host);
1004                 } else {
1005                         cancel_port = a2port(cancel_host);
1006                         cancel_host = NULL;
1007                 }
1008                 if (cancel_port == 0) {
1009                         logit("Bad forwarding close port");
1010                         goto out;
1011                 }
1012                 channel_request_rforward_cancel(cancel_host, cancel_port);
1013         } else {
1014                 if (!parse_forward(&fwd, s)) {
1015                         logit("Bad forwarding specification.");
1016                         goto out;
1017                 }
1018                 if (local) {
1019                         if (channel_setup_local_fwd_listener(fwd.listen_host,
1020                             fwd.listen_port, fwd.connect_host,
1021                             fwd.connect_port, options.gateway_ports) < 0) {
1022                                 logit("Port forwarding failed.");
1023                                 goto out;
1024                         }
1025                 } else {
1026                         if (channel_request_remote_forwarding(fwd.listen_host,
1027                             fwd.listen_port, fwd.connect_host,
1028                             fwd.connect_port) < 0) {
1029                                 logit("Port forwarding failed.");
1030                                 goto out;
1031                         }
1032                 }
1033
1034                 logit("Forwarding port.");
1035         }
1036
1037 out:
1038         signal(SIGINT, handler);
1039         enter_raw_mode();
1040         if (cmd)
1041                 xfree(cmd);
1042 }
1043
1044 /* process the characters one by one */
1045 static int
1046 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
1047 {
1048         char string[1024];
1049         pid_t pid;
1050         int bytes = 0;
1051         u_int i;
1052         u_char ch;
1053         char *s;
1054
1055         if (len <= 0)
1056                 return (0);
1057
1058         for (i = 0; i < (u_int)len; i++) {
1059                 /* Get one character at a time. */
1060                 ch = buf[i];
1061
1062                 if (escape_pending) {
1063                         /* We have previously seen an escape character. */
1064                         /* Clear the flag now. */
1065                         escape_pending = 0;
1066
1067                         /* Process the escaped character. */
1068                         switch (ch) {
1069                         case '.':
1070                                 /* Terminate the connection. */
1071                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
1072                                 buffer_append(berr, string, strlen(string));
1073
1074                                 quit_pending = 1;
1075                                 return -1;
1076
1077                         case 'Z' - 64:
1078                                 /* Suspend the program. */
1079                                 /* Print a message to that effect to the user. */
1080                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
1081                                 buffer_append(berr, string, strlen(string));
1082
1083                                 /* Restore terminal modes and suspend. */
1084                                 client_suspend_self(bin, bout, berr);
1085
1086                                 /* We have been continued. */
1087                                 continue;
1088
1089                         case 'B':
1090                                 if (compat20) {
1091                                         snprintf(string, sizeof string,
1092                                             "%cB\r\n", escape_char);
1093                                         buffer_append(berr, string,
1094                                             strlen(string));
1095                                         channel_request_start(session_ident,
1096                                             "break", 0);
1097                                         packet_put_int(1000);
1098                                         packet_send();
1099                                 }
1100                                 continue;
1101
1102                         case 'R':
1103                                 if (compat20) {
1104                                         if (datafellows & SSH_BUG_NOREKEY)
1105                                                 logit("Server does not support re-keying");
1106                                         else
1107                                                 need_rekeying = 1;
1108                                 }
1109                                 continue;
1110
1111                         case '&':
1112                                 /*
1113                                  * Detach the program (continue to serve connections,
1114                                  * but put in background and no more new connections).
1115                                  */
1116                                 /* Restore tty modes. */
1117                                 leave_raw_mode();
1118
1119                                 /* Stop listening for new connections. */
1120                                 channel_stop_listening();
1121
1122                                 snprintf(string, sizeof string,
1123                                     "%c& [backgrounded]\n", escape_char);
1124                                 buffer_append(berr, string, strlen(string));
1125
1126                                 /* Fork into background. */
1127                                 pid = fork();
1128                                 if (pid < 0) {
1129                                         error("fork: %.100s", strerror(errno));
1130                                         continue;
1131                                 }
1132                                 if (pid != 0) { /* This is the parent. */
1133                                         /* The parent just exits. */
1134                                         exit(0);
1135                                 }
1136                                 /* The child continues serving connections. */
1137                                 if (compat20) {
1138                                         buffer_append(bin, "\004", 1);
1139                                         /* fake EOF on stdin */
1140                                         return -1;
1141                                 } else if (!stdin_eof) {
1142                                         /*
1143                                          * Sending SSH_CMSG_EOF alone does not always appear
1144                                          * to be enough.  So we try to send an EOF character
1145                                          * first.
1146                                          */
1147                                         packet_start(SSH_CMSG_STDIN_DATA);
1148                                         packet_put_string("\004", 1);
1149                                         packet_send();
1150                                         /* Close stdin. */
1151                                         stdin_eof = 1;
1152                                         if (buffer_len(bin) == 0) {
1153                                                 packet_start(SSH_CMSG_EOF);
1154                                                 packet_send();
1155                                         }
1156                                 }
1157                                 continue;
1158
1159                         case '?':
1160                                 snprintf(string, sizeof string,
1161 "%c?\r\n\
1162 Supported escape sequences:\r\n\
1163 %c.  - terminate connection\r\n\
1164 %cB  - send a BREAK to the remote system\r\n\
1165 %cC  - open a command line\r\n\
1166 %cR  - Request rekey (SSH protocol 2 only)\r\n\
1167 %c^Z - suspend ssh\r\n\
1168 %c#  - list forwarded connections\r\n\
1169 %c&  - background ssh (when waiting for connections to terminate)\r\n\
1170 %c?  - this message\r\n\
1171 %c%c  - send the escape character by typing it twice\r\n\
1172 (Note that escapes are only recognized immediately after newline.)\r\n",
1173                                     escape_char, escape_char, escape_char, escape_char,
1174                                     escape_char, escape_char, escape_char, escape_char,
1175                                     escape_char, escape_char, escape_char);
1176                                 buffer_append(berr, string, strlen(string));
1177                                 continue;
1178
1179                         case '#':
1180                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
1181                                 buffer_append(berr, string, strlen(string));
1182                                 s = channel_open_message();
1183                                 buffer_append(berr, s, strlen(s));
1184                                 xfree(s);
1185                                 continue;
1186
1187                         case 'C':
1188                                 process_cmdline();
1189                                 continue;
1190
1191                         default:
1192                                 if (ch != escape_char) {
1193                                         buffer_put_char(bin, escape_char);
1194                                         bytes++;
1195                                 }
1196                                 /* Escaped characters fall through here */
1197                                 break;
1198                         }
1199                 } else {
1200                         /*
1201                          * The previous character was not an escape char. Check if this
1202                          * is an escape.
1203                          */
1204                         if (last_was_cr && ch == escape_char) {
1205                                 /* It is. Set the flag and continue to next character. */
1206                                 escape_pending = 1;
1207                                 continue;
1208                         }
1209                 }
1210
1211                 /*
1212                  * Normal character.  Record whether it was a newline,
1213                  * and append it to the buffer.
1214                  */
1215                 last_was_cr = (ch == '\r' || ch == '\n');
1216                 buffer_put_char(bin, ch);
1217                 bytes++;
1218         }
1219         return bytes;
1220 }
1221
1222 static void
1223 client_process_input(fd_set *readset)
1224 {
1225         int len;
1226         char buf[8192];
1227
1228         /* Read input from stdin. */
1229         if (FD_ISSET(fileno(stdin), readset)) {
1230                 /* Read as much as possible. */
1231                 len = read(fileno(stdin), buf, sizeof(buf));
1232                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
1233                         return;         /* we'll try again later */
1234                 if (len <= 0) {
1235                         /*
1236                          * Received EOF or error.  They are treated
1237                          * similarly, except that an error message is printed
1238                          * if it was an error condition.
1239                          */
1240                         if (len < 0) {
1241                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
1242                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1243                         }
1244                         /* Mark that we have seen EOF. */
1245                         stdin_eof = 1;
1246                         /*
1247                          * Send an EOF message to the server unless there is
1248                          * data in the buffer.  If there is data in the
1249                          * buffer, no message will be sent now.  Code
1250                          * elsewhere will send the EOF when the buffer
1251                          * becomes empty if stdin_eof is set.
1252                          */
1253                         if (buffer_len(&stdin_buffer) == 0) {
1254                                 packet_start(SSH_CMSG_EOF);
1255                                 packet_send();
1256                         }
1257                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
1258                         /*
1259                          * Normal successful read, and no escape character.
1260                          * Just append the data to buffer.
1261                          */
1262                         buffer_append(&stdin_buffer, buf, len);
1263                 } else {
1264                         /*
1265                          * Normal, successful read.  But we have an escape character
1266                          * and have to process the characters one by one.
1267                          */
1268                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1269                             &stderr_buffer, buf, len) == -1)
1270                                 return;
1271                 }
1272         }
1273 }
1274
1275 static void
1276 client_process_output(fd_set *writeset)
1277 {
1278         int len;
1279         char buf[100];
1280
1281         /* Write buffered output to stdout. */
1282         if (FD_ISSET(fileno(stdout), writeset)) {
1283                 /* Write as much data as possible. */
1284                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1285                     buffer_len(&stdout_buffer));
1286                 if (len <= 0) {
1287                         if (errno == EINTR || errno == EAGAIN)
1288                                 len = 0;
1289                         else {
1290                                 /*
1291                                  * An error or EOF was encountered.  Put an
1292                                  * error message to stderr buffer.
1293                                  */
1294                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1295                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1296                                 quit_pending = 1;
1297                                 return;
1298                         }
1299                 }
1300                 /* Consume printed data from the buffer. */
1301                 buffer_consume(&stdout_buffer, len);
1302                 stdout_bytes += len;
1303         }
1304         /* Write buffered output to stderr. */
1305         if (FD_ISSET(fileno(stderr), writeset)) {
1306                 /* Write as much data as possible. */
1307                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1308                     buffer_len(&stderr_buffer));
1309                 if (len <= 0) {
1310                         if (errno == EINTR || errno == EAGAIN)
1311                                 len = 0;
1312                         else {
1313                                 /* EOF or error, but can't even print error message. */
1314                                 quit_pending = 1;
1315                                 return;
1316                         }
1317                 }
1318                 /* Consume printed characters from the buffer. */
1319                 buffer_consume(&stderr_buffer, len);
1320                 stderr_bytes += len;
1321         }
1322 }
1323
1324 /*
1325  * Get packets from the connection input buffer, and process them as long as
1326  * there are packets available.
1327  *
1328  * Any unknown packets received during the actual
1329  * session cause the session to terminate.  This is
1330  * intended to make debugging easier since no
1331  * confirmations are sent.  Any compatible protocol
1332  * extensions must be negotiated during the
1333  * preparatory phase.
1334  */
1335
1336 static void
1337 client_process_buffered_input_packets(void)
1338 {
1339         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1340 }
1341
1342 /* scan buf[] for '~' before sending data to the peer */
1343
1344 static int
1345 simple_escape_filter(Channel *c, char *buf, int len)
1346 {
1347         /* XXX we assume c->extended is writeable */
1348         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1349 }
1350
1351 static void
1352 client_channel_closed(int id, void *arg)
1353 {
1354         channel_cancel_cleanup(id);
1355         session_closed = 1;
1356         leave_raw_mode();
1357 }
1358
1359 /*
1360  * Implements the interactive session with the server.  This is called after
1361  * the user has been authenticated, and a command has been started on the
1362  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1363  * used as an escape character for terminating or suspending the session.
1364  */
1365
1366 int
1367 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1368 {
1369         fd_set *readset = NULL, *writeset = NULL;
1370         double start_time, total_time;
1371         int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1372         u_int nalloc = 0;
1373         char buf[100];
1374
1375         debug("Entering interactive session.");
1376
1377         start_time = get_current_time();
1378
1379         /* Initialize variables. */
1380         escape_pending = 0;
1381         last_was_cr = 1;
1382         exit_status = -1;
1383         stdin_eof = 0;
1384         buffer_high = 64 * 1024;
1385         connection_in = packet_get_connection_in();
1386         connection_out = packet_get_connection_out();
1387         max_fd = MAX(connection_in, connection_out);
1388         if (control_fd != -1)
1389                 max_fd = MAX(max_fd, control_fd);
1390
1391         if (!compat20) {
1392                 /* enable nonblocking unless tty */
1393                 if (!isatty(fileno(stdin)))
1394                         set_nonblock(fileno(stdin));
1395                 if (!isatty(fileno(stdout)))
1396                         set_nonblock(fileno(stdout));
1397                 if (!isatty(fileno(stderr)))
1398                         set_nonblock(fileno(stderr));
1399                 max_fd = MAX(max_fd, fileno(stdin));
1400                 max_fd = MAX(max_fd, fileno(stdout));
1401                 max_fd = MAX(max_fd, fileno(stderr));
1402         }
1403         stdin_bytes = 0;
1404         stdout_bytes = 0;
1405         stderr_bytes = 0;
1406         quit_pending = 0;
1407         escape_char = escape_char_arg;
1408
1409         /* Initialize buffers. */
1410         buffer_init(&stdin_buffer);
1411         buffer_init(&stdout_buffer);
1412         buffer_init(&stderr_buffer);
1413
1414         client_init_dispatch();
1415
1416         /*
1417          * Set signal handlers, (e.g. to restore non-blocking mode)
1418          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1419          */
1420         if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1421                 signal(SIGHUP, signal_handler);
1422         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1423                 signal(SIGINT, signal_handler);
1424         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1425                 signal(SIGQUIT, signal_handler);
1426         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1427                 signal(SIGTERM, signal_handler);
1428         signal(SIGWINCH, window_change_handler);
1429
1430         if (have_pty)
1431                 enter_raw_mode();
1432
1433         if (compat20) {
1434                 session_ident = ssh2_chan_id;
1435                 if (escape_char != SSH_ESCAPECHAR_NONE)
1436                         channel_register_filter(session_ident,
1437                             simple_escape_filter, NULL);
1438                 if (session_ident != -1)
1439                         channel_register_cleanup(session_ident,
1440                             client_channel_closed, 0);
1441         } else {
1442                 /* Check if we should immediately send eof on stdin. */
1443                 client_check_initial_eof_on_stdin();
1444         }
1445
1446         /* Main loop of the client for the interactive session mode. */
1447         while (!quit_pending) {
1448
1449                 /* Process buffered packets sent by the server. */
1450                 client_process_buffered_input_packets();
1451
1452                 if (compat20 && session_closed && !channel_still_open())
1453                         break;
1454
1455                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1456
1457                 if (rekeying) {
1458                         debug("rekeying in progress");
1459                 } else {
1460                         /*
1461                          * Make packets of buffered stdin data, and buffer
1462                          * them for sending to the server.
1463                          */
1464                         if (!compat20)
1465                                 client_make_packets_from_stdin_data();
1466
1467                         /*
1468                          * Make packets from buffered channel data, and
1469                          * enqueue them for sending to the server.
1470                          */
1471                         if (packet_not_very_much_data_to_write())
1472                                 channel_output_poll();
1473
1474                         /*
1475                          * Check if the window size has changed, and buffer a
1476                          * message about it to the server if so.
1477                          */
1478                         client_check_window_change();
1479
1480                         if (quit_pending)
1481                                 break;
1482                 }
1483                 /*
1484                  * Wait until we have something to do (something becomes
1485                  * available on one of the descriptors).
1486                  */
1487                 max_fd2 = max_fd;
1488                 client_wait_until_can_do_something(&readset, &writeset,
1489                     &max_fd2, &nalloc, rekeying);
1490
1491                 if (quit_pending)
1492                         break;
1493
1494                 /* Do channel operations unless rekeying in progress. */
1495                 if (!rekeying) {
1496                         channel_after_select(readset, writeset);
1497                         if (need_rekeying || packet_need_rekeying()) {
1498                                 debug("need rekeying");
1499                                 xxx_kex->done = 0;
1500                                 kex_send_kexinit(xxx_kex);
1501                                 need_rekeying = 0;
1502                         }
1503                 }
1504
1505                 /* Buffer input from the connection.  */
1506                 client_process_net_input(readset);
1507
1508                 /* Accept control connections.  */
1509                 client_process_control(readset);
1510
1511                 if (quit_pending)
1512                         break;
1513
1514                 if (!compat20) {
1515                         /* Buffer data from stdin */
1516                         client_process_input(readset);
1517                         /*
1518                          * Process output to stdout and stderr.  Output to
1519                          * the connection is processed elsewhere (above).
1520                          */
1521                         client_process_output(writeset);
1522                 }
1523
1524                 /* Send as much buffered packet data as possible to the sender. */
1525                 if (FD_ISSET(connection_out, writeset))
1526                         packet_write_poll();
1527         }
1528         if (readset)
1529                 xfree(readset);
1530         if (writeset)
1531                 xfree(writeset);
1532
1533         /* Terminate the session. */
1534
1535         /* Stop watching for window change. */
1536         signal(SIGWINCH, SIG_DFL);
1537
1538         channel_free_all();
1539
1540         if (have_pty)
1541                 leave_raw_mode();
1542
1543         /* restore blocking io */
1544         if (!isatty(fileno(stdin)))
1545                 unset_nonblock(fileno(stdin));
1546         if (!isatty(fileno(stdout)))
1547                 unset_nonblock(fileno(stdout));
1548         if (!isatty(fileno(stderr)))
1549                 unset_nonblock(fileno(stderr));
1550
1551         /*
1552          * If there was no shell or command requested, there will be no remote
1553          * exit status to be returned.  In that case, clear error code if the
1554          * connection was deliberately terminated at this end.
1555          */
1556         if (no_shell_flag && received_signal == SIGTERM) {
1557                 received_signal = 0;
1558                 exit_status = 0;
1559         }
1560
1561         if (received_signal)
1562                 fatal("Killed by signal %d.", (int) received_signal);
1563
1564         /*
1565          * In interactive mode (with pseudo tty) display a message indicating
1566          * that the connection has been closed.
1567          */
1568         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1569                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1570                 buffer_append(&stderr_buffer, buf, strlen(buf));
1571         }
1572
1573         /* Output any buffered data for stdout. */
1574         while (buffer_len(&stdout_buffer) > 0) {
1575                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1576                     buffer_len(&stdout_buffer));
1577                 if (len <= 0) {
1578                         error("Write failed flushing stdout buffer.");
1579                         break;
1580                 }
1581                 buffer_consume(&stdout_buffer, len);
1582                 stdout_bytes += len;
1583         }
1584
1585         /* Output any buffered data for stderr. */
1586         while (buffer_len(&stderr_buffer) > 0) {
1587                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1588                     buffer_len(&stderr_buffer));
1589                 if (len <= 0) {
1590                         error("Write failed flushing stderr buffer.");
1591                         break;
1592                 }
1593                 buffer_consume(&stderr_buffer, len);
1594                 stderr_bytes += len;
1595         }
1596
1597         /* Clear and free any buffers. */
1598         memset(buf, 0, sizeof(buf));
1599         buffer_free(&stdin_buffer);
1600         buffer_free(&stdout_buffer);
1601         buffer_free(&stderr_buffer);
1602
1603         /* Report bytes transferred, and transfer rates. */
1604         total_time = get_current_time() - start_time;
1605         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1606             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1607         if (total_time > 0)
1608                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1609                     stdin_bytes / total_time, stdout_bytes / total_time,
1610                     stderr_bytes / total_time);
1611
1612         /* Return the exit status of the program. */
1613         debug("Exit status %d", exit_status);
1614         return exit_status;
1615 }
1616
1617 /*********/
1618
1619 static void
1620 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1621 {
1622         u_int data_len;
1623         char *data = packet_get_string(&data_len);
1624         packet_check_eom();
1625         buffer_append(&stdout_buffer, data, data_len);
1626         memset(data, 0, data_len);
1627         xfree(data);
1628 }
1629 static void
1630 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1631 {
1632         u_int data_len;
1633         char *data = packet_get_string(&data_len);
1634         packet_check_eom();
1635         buffer_append(&stderr_buffer, data, data_len);
1636         memset(data, 0, data_len);
1637         xfree(data);
1638 }
1639 static void
1640 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1641 {
1642         exit_status = packet_get_int();
1643         packet_check_eom();
1644         /* Acknowledge the exit. */
1645         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1646         packet_send();
1647         /*
1648          * Must wait for packet to be sent since we are
1649          * exiting the loop.
1650          */
1651         packet_write_wait();
1652         /* Flag that we want to exit. */
1653         quit_pending = 1;
1654 }
1655 static void
1656 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1657 {
1658         Channel *c = NULL;
1659         int remote_id, sock;
1660
1661         /* Read the remote channel number from the message. */
1662         remote_id = packet_get_int();
1663         packet_check_eom();
1664
1665         /*
1666          * Get a connection to the local authentication agent (this may again
1667          * get forwarded).
1668          */
1669         sock = ssh_get_authentication_socket();
1670
1671         /*
1672          * If we could not connect the agent, send an error message back to
1673          * the server. This should never happen unless the agent dies,
1674          * because authentication forwarding is only enabled if we have an
1675          * agent.
1676          */
1677         if (sock >= 0) {
1678                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1679                     -1, 0, 0, 0, "authentication agent connection", 1);
1680                 c->remote_id = remote_id;
1681                 c->force_drain = 1;
1682         }
1683         if (c == NULL) {
1684                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1685                 packet_put_int(remote_id);
1686         } else {
1687                 /* Send a confirmation to the remote host. */
1688                 debug("Forwarding authentication connection.");
1689                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1690                 packet_put_int(remote_id);
1691                 packet_put_int(c->self);
1692         }
1693         packet_send();
1694 }
1695
1696 static Channel *
1697 client_request_forwarded_tcpip(const char *request_type, int rchan)
1698 {
1699         Channel *c = NULL;
1700         char *listen_address, *originator_address;
1701         int listen_port, originator_port;
1702         int sock;
1703
1704         /* Get rest of the packet */
1705         listen_address = packet_get_string(NULL);
1706         listen_port = packet_get_int();
1707         originator_address = packet_get_string(NULL);
1708         originator_port = packet_get_int();
1709         packet_check_eom();
1710
1711         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1712             listen_address, listen_port, originator_address, originator_port);
1713
1714         sock = channel_connect_by_listen_address(listen_port);
1715         if (sock < 0) {
1716                 xfree(originator_address);
1717                 xfree(listen_address);
1718                 return NULL;
1719         }
1720         c = channel_new("forwarded-tcpip",
1721             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1722             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 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         c = channel_new("x11",
1758             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1759             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1760         c->force_drain = 1;
1761         return c;
1762 }
1763
1764 static Channel *
1765 client_request_agent(const char *request_type, int rchan)
1766 {
1767         Channel *c = NULL;
1768         int sock;
1769
1770         if (!options.forward_agent) {
1771                 error("Warning: ssh server tried agent forwarding.");
1772                 error("Warning: this is probably a break-in attempt by a malicious server.");
1773                 return NULL;
1774         }
1775         sock = ssh_get_authentication_socket();
1776         if (sock < 0)
1777                 return NULL;
1778         c = channel_new("authentication agent connection",
1779             SSH_CHANNEL_OPEN, sock, sock, -1,
1780             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1781             "authentication agent connection", 1);
1782         c->force_drain = 1;
1783         return c;
1784 }
1785
1786 int
1787 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1788 {
1789         Channel *c;
1790         int fd;
1791
1792         if (tun_mode == SSH_TUNMODE_NO)
1793                 return 0;
1794
1795         if (!compat20) {
1796                 error("Tunnel forwarding is not support for protocol 1");
1797                 return -1;
1798         }
1799
1800         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1801
1802         /* Open local tunnel device */
1803         if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1804                 error("Tunnel device open failed.");
1805                 return -1;
1806         }
1807
1808         c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1809             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1810         c->datagram = 1;
1811
1812 #if defined(SSH_TUN_FILTER)
1813         if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1814                 channel_register_filter(c->self, sys_tun_infilter,
1815                     sys_tun_outfilter);
1816 #endif
1817
1818         packet_start(SSH2_MSG_CHANNEL_OPEN);
1819         packet_put_cstring("tun@openssh.com");
1820         packet_put_int(c->self);
1821         packet_put_int(c->local_window_max);
1822         packet_put_int(c->local_maxpacket);
1823         packet_put_int(tun_mode);
1824         packet_put_int(remote_tun);
1825         packet_send();
1826
1827         return 0;
1828 }
1829
1830 /* XXXX move to generic input handler */
1831 static void
1832 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1833 {
1834         Channel *c = NULL;
1835         char *ctype;
1836         int rchan;
1837         u_int rmaxpack, rwindow, len;
1838
1839         ctype = packet_get_string(&len);
1840         rchan = packet_get_int();
1841         rwindow = packet_get_int();
1842         rmaxpack = packet_get_int();
1843
1844         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1845             ctype, rchan, rwindow, rmaxpack);
1846
1847         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1848                 c = client_request_forwarded_tcpip(ctype, rchan);
1849         } else if (strcmp(ctype, "x11") == 0) {
1850                 c = client_request_x11(ctype, rchan);
1851         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1852                 c = client_request_agent(ctype, rchan);
1853         }
1854 /* XXX duplicate : */
1855         if (c != NULL) {
1856                 debug("confirm %s", ctype);
1857                 c->remote_id = rchan;
1858                 c->remote_window = rwindow;
1859                 c->remote_maxpacket = rmaxpack;
1860                 if (c->type != SSH_CHANNEL_CONNECTING) {
1861                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1862                         packet_put_int(c->remote_id);
1863                         packet_put_int(c->self);
1864                         packet_put_int(c->local_window);
1865                         packet_put_int(c->local_maxpacket);
1866                         packet_send();
1867                 }
1868         } else {
1869                 debug("failure %s", ctype);
1870                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1871                 packet_put_int(rchan);
1872                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1873                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1874                         packet_put_cstring("open failed");
1875                         packet_put_cstring("");
1876                 }
1877                 packet_send();
1878         }
1879         xfree(ctype);
1880 }
1881 static void
1882 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1883 {
1884         Channel *c = NULL;
1885         int exitval, id, reply, success = 0;
1886         char *rtype;
1887
1888         id = packet_get_int();
1889         rtype = packet_get_string(NULL);
1890         reply = packet_get_char();
1891
1892         debug("client_input_channel_req: channel %d rtype %s reply %d",
1893             id, rtype, reply);
1894
1895         if (id == -1) {
1896                 error("client_input_channel_req: request for channel -1");
1897         } else if ((c = channel_lookup(id)) == NULL) {
1898                 error("client_input_channel_req: channel %d: unknown channel", id);
1899         } else if (strcmp(rtype, "exit-status") == 0) {
1900                 exitval = packet_get_int();
1901                 if (id == session_ident) {
1902                         success = 1;
1903                         exit_status = exitval;
1904                 } else if (c->ctl_fd == -1) {
1905                         error("client_input_channel_req: unexpected channel %d",
1906                             session_ident);
1907                 } else {
1908                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1909                         success = 1;
1910                 }
1911                 packet_check_eom();
1912         }
1913         if (reply) {
1914                 packet_start(success ?
1915                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1916                 packet_put_int(id);
1917                 packet_send();
1918         }
1919         xfree(rtype);
1920 }
1921 static void
1922 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1923 {
1924         char *rtype;
1925         int want_reply;
1926         int success = 0;
1927
1928         rtype = packet_get_string(NULL);
1929         want_reply = packet_get_char();
1930         debug("client_input_global_request: rtype %s want_reply %d",
1931             rtype, want_reply);
1932         if (want_reply) {
1933                 packet_start(success ?
1934                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1935                 packet_send();
1936                 packet_write_wait();
1937         }
1938         xfree(rtype);
1939 }
1940
1941 void
1942 client_session2_setup(int id, int want_tty, int want_subsystem,
1943     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
1944     dispatch_fn *subsys_repl)
1945 {
1946         int len;
1947         Channel *c = NULL;
1948
1949         debug2("%s: id %d", __func__, id);
1950
1951         if ((c = channel_lookup(id)) == NULL)
1952                 fatal("client_session2_setup: channel %d: unknown channel", id);
1953
1954         if (want_tty) {
1955                 struct winsize ws;
1956                 struct termios tio;
1957
1958                 /* Store window size in the packet. */
1959                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1960                         memset(&ws, 0, sizeof(ws));
1961
1962                 channel_request_start(id, "pty-req", 0);
1963                 packet_put_cstring(term != NULL ? term : "");
1964                 packet_put_int((u_int)ws.ws_col);
1965                 packet_put_int((u_int)ws.ws_row);
1966                 packet_put_int((u_int)ws.ws_xpixel);
1967                 packet_put_int((u_int)ws.ws_ypixel);
1968                 tio = get_saved_tio();
1969                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1970                 packet_send();
1971                 /* XXX wait for reply */
1972                 c->client_tty = 1;
1973         }
1974
1975         /* Transfer any environment variables from client to server */
1976         if (options.num_send_env != 0 && env != NULL) {
1977                 int i, j, matched;
1978                 char *name, *val;
1979
1980                 debug("Sending environment.");
1981                 for (i = 0; env[i] != NULL; i++) {
1982                         /* Split */
1983                         name = xstrdup(env[i]);
1984                         if ((val = strchr(name, '=')) == NULL) {
1985                                 xfree(name);
1986                                 continue;
1987                         }
1988                         *val++ = '\0';
1989
1990                         matched = 0;
1991                         for (j = 0; j < options.num_send_env; j++) {
1992                                 if (match_pattern(name, options.send_env[j])) {
1993                                         matched = 1;
1994                                         break;
1995                                 }
1996                         }
1997                         if (!matched) {
1998                                 debug3("Ignored env %s", name);
1999                                 xfree(name);
2000                                 continue;
2001                         }
2002
2003                         debug("Sending env %s = %s", name, val);
2004                         channel_request_start(id, "env", 0);
2005                         packet_put_cstring(name);
2006                         packet_put_cstring(val);
2007                         packet_send();
2008                         xfree(name);
2009                 }
2010         }
2011
2012         len = buffer_len(cmd);
2013         if (len > 0) {
2014                 if (len > 900)
2015                         len = 900;
2016                 if (want_subsystem) {
2017                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
2018                         channel_request_start(id, "subsystem", subsys_repl != NULL);
2019                         if (subsys_repl != NULL) {
2020                                 /* register callback for reply */
2021                                 /* XXX we assume that client_loop has already been called */
2022                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
2023                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
2024                         }
2025                 } else {
2026                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
2027                         channel_request_start(id, "exec", 0);
2028                 }
2029                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2030                 packet_send();
2031         } else {
2032                 channel_request_start(id, "shell", 0);
2033                 packet_send();
2034         }
2035 }
2036
2037 static void
2038 client_init_dispatch_20(void)
2039 {
2040         dispatch_init(&dispatch_protocol_error);
2041
2042         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2043         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2044         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2045         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2046         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2047         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2048         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2049         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2050         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2051         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2052
2053         /* rekeying */
2054         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2055
2056         /* global request reply messages */
2057         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2058         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2059 }
2060 static void
2061 client_init_dispatch_13(void)
2062 {
2063         dispatch_init(NULL);
2064         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2065         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2066         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2067         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2068         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2069         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2070         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2071         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2072         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2073
2074         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2075             &client_input_agent_open : &deny_input_open);
2076         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2077             &x11_input_open : &deny_input_open);
2078 }
2079 static void
2080 client_init_dispatch_15(void)
2081 {
2082         client_init_dispatch_13();
2083         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2084         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2085 }
2086 static void
2087 client_init_dispatch(void)
2088 {
2089         if (compat20)
2090                 client_init_dispatch_20();
2091         else if (compat13)
2092                 client_init_dispatch_13();
2093         else
2094                 client_init_dispatch_15();
2095 }
2096
2097 /* client specific fatal cleanup */
2098 void
2099 cleanup_exit(int i)
2100 {
2101         leave_raw_mode();
2102         leave_non_blocking();
2103         if (options.control_path != NULL && control_fd != -1)
2104                 unlink(options.control_path);
2105         _exit(i);
2106 }