clientloop.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * The main loop for the interactive session (client side).
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  *
  13  *
  14  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  *
  37  * SSH2 support added by Markus Friedl.
  38  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  59  */
  60
  61 #include "includes.h"
  62 RCSID("$OpenBSD: clientloop.c,v 1.124 2004/06/14 01:44:38 djm Exp $");
  63
  64 #include "ssh.h"
  65 #include "ssh1.h"
  66 #include "ssh2.h"
  67 #include "xmalloc.h"
  68 #include "packet.h"
  69 #include "buffer.h"
  70 #include "compat.h"
  71 #include "channels.h"
  72 #include "dispatch.h"
  73 #include "buffer.h"
  74 #include "bufaux.h"
  75 #include "key.h"
  76 #include "kex.h"
  77 #include "log.h"
  78 #include "readconf.h"
  79 #include "clientloop.h"
  80 #include "authfd.h"
  81 #include "atomicio.h"
  82 #include "sshpty.h"
  83 #include "misc.h"
  84 #include "monitor_fdpass.h"
  85 #include "match.h"
  86 #include "msg.h"
  87
  88 /* import options */
  89 extern Options options;
  90
  91 /* Flag indicating that stdin should be redirected from /dev/null. */
  92 extern int stdin_null_flag;
  93
  94 /* Flag indicating that no shell has been requested */
  95 extern int no_shell_flag;
  96
  97 /* Control socket */
  98 extern int control_fd;
  99
 100 /*
 101  * Name of the host we are connecting to.  This is the name given on the
 102  * command line, or the HostName specified for the user-supplied name in a
 103  * configuration file.
 104  */
 105 extern char *host;
 106
 107 /*
 108  * Flag to indicate that we have received a window change signal which has
 109  * not yet been processed.  This will cause a message indicating the new
 110  * window size to be sent to the server a little later.  This is volatile
 111  * because this is updated in a signal handler.
 112  */
 113 static volatile sig_atomic_t received_window_change_signal = 0;
 114 static volatile sig_atomic_t received_signal = 0;
 115
 116 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
 117 static int in_non_blocking_mode = 0;
 118
 119 /* Common data for the client loop code. */
 120 static int quit_pending;        /* Set to non-zero to quit the client loop. */
 121 static int escape_char;         /* Escape character. */
 122 static int escape_pending;      /* Last character was the escape character */
 123 static int last_was_cr;         /* Last character was a newline. */
 124 static int exit_status;         /* Used to store the exit status of the command. */
 125 static int stdin_eof;           /* EOF has been encountered on standard error. */
 126 static Buffer stdin_buffer;     /* Buffer for stdin data. */
 127 static Buffer stdout_buffer;    /* Buffer for stdout data. */
 128 static Buffer stderr_buffer;    /* Buffer for stderr data. */
 129 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
 130 static u_int buffer_high;/* Soft max buffer size. */
 131 static int connection_in;       /* Connection to server (input). */
 132 static int connection_out;      /* Connection to server (output). */
 133 static int need_rekeying;       /* Set to non-zero if rekeying is requested. */
 134 static int session_closed = 0;  /* In SSH2: login session closed. */
 135 static int server_alive_timeouts = 0;
 136
 137 static void client_init_dispatch(void);
 138 int     session_ident = -1;
 139
 140 struct confirm_ctx {
 141         int want_tty;
 142         int want_subsys;
 143         Buffer cmd;
 144         char *term;
 145         struct termios tio;
 146 };
 147
 148 /*XXX*/
 149 extern Kex *xxx_kex;
 150
 151 void ssh_process_session2_setup(int, int, int, Buffer *);
 152
 153 /* Restores stdin to blocking mode. */
 154
 155 static void
 156 leave_non_blocking(void)
 157 {
 158         if (in_non_blocking_mode) {
 159                 (void) fcntl(fileno(stdin), F_SETFL, 0);
 160                 in_non_blocking_mode = 0;
 161         }
 162 }
 163
 164 /* Puts stdin terminal in non-blocking mode. */
 165
 166 static void
 167 enter_non_blocking(void)
 168 {
 169         in_non_blocking_mode = 1;
 170         set_nonblock(fileno(stdin));
 171 }
 172
 173 /*
 174  * Signal handler for the window change signal (SIGWINCH).  This just sets a
 175  * flag indicating that the window has changed.
 176  */
 177
 178 static void
 179 window_change_handler(int sig)
 180 {
 181         received_window_change_signal = 1;
 182         signal(SIGWINCH, window_change_handler);
 183 }
 184
 185 /*
 186  * Signal handler for signals that cause the program to terminate.  These
 187  * signals must be trapped to restore terminal modes.
 188  */
 189
 190 static void
 191 signal_handler(int sig)
 192 {
 193         received_signal = sig;
 194         quit_pending = 1;
 195 }
 196
 197 /*
 198  * Returns current time in seconds from Jan 1, 1970 with the maximum
 199  * available resolution.
 200  */
 201
 202 static double
 203 get_current_time(void)
 204 {
 205         struct timeval tv;
 206         gettimeofday(&tv, NULL);
 207         return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 208 }
 209
 210 /*
 211  * This is called when the interactive is entered.  This checks if there is
 212  * an EOF coming on stdin.  We must check this explicitly, as select() does
 213  * not appear to wake up when redirecting from /dev/null.
 214  */
 215
 216 static void
 217 client_check_initial_eof_on_stdin(void)
 218 {
 219         int len;
 220         char buf[1];
 221
 222         /*
 223          * If standard input is to be "redirected from /dev/null", we simply
 224          * mark that we have seen an EOF and send an EOF message to the
 225          * server. Otherwise, we try to read a single character; it appears
 226          * that for some files, such /dev/null, select() never wakes up for
 227          * read for this descriptor, which means that we never get EOF.  This
 228          * way we will get the EOF if stdin comes from /dev/null or similar.
 229          */
 230         if (stdin_null_flag) {
 231                 /* Fake EOF on stdin. */
 232                 debug("Sending eof.");
 233                 stdin_eof = 1;
 234                 packet_start(SSH_CMSG_EOF);
 235                 packet_send();
 236         } else {
 237                 enter_non_blocking();
 238
 239                 /* Check for immediate EOF on stdin. */
 240                 len = read(fileno(stdin), buf, 1);
 241                 if (len == 0) {
 242                         /* EOF.  Record that we have seen it and send EOF to server. */
 243                         debug("Sending eof.");
 244                         stdin_eof = 1;
 245                         packet_start(SSH_CMSG_EOF);
 246                         packet_send();
 247                 } else if (len > 0) {
 248                         /*
 249                          * Got data.  We must store the data in the buffer,
 250                          * and also process it as an escape character if
 251                          * appropriate.
 252                          */
 253                         if ((u_char) buf[0] == escape_char)
 254                                 escape_pending = 1;
 255                         else
 256                                 buffer_append(&stdin_buffer, buf, 1);
 257                 }
 258                 leave_non_blocking();
 259         }
 260 }
 261
 262
 263 /*
 264  * Make packets from buffered stdin data, and buffer them for sending to the
 265  * connection.
 266  */
 267
 268 static void
 269 client_make_packets_from_stdin_data(void)
 270 {
 271         u_int len;
 272
 273         /* Send buffered stdin data to the server. */
 274         while (buffer_len(&stdin_buffer) > 0 &&
 275             packet_not_very_much_data_to_write()) {
 276                 len = buffer_len(&stdin_buffer);
 277                 /* Keep the packets at reasonable size. */
 278                 if (len > packet_get_maxsize())
 279                         len = packet_get_maxsize();
 280                 packet_start(SSH_CMSG_STDIN_DATA);
 281                 packet_put_string(buffer_ptr(&stdin_buffer), len);
 282                 packet_send();
 283                 buffer_consume(&stdin_buffer, len);
 284                 stdin_bytes += len;
 285                 /* If we have a pending EOF, send it now. */
 286                 if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
 287                         packet_start(SSH_CMSG_EOF);
 288                         packet_send();
 289                 }
 290         }
 291 }
 292
 293 /*
 294  * Checks if the client window has changed, and sends a packet about it to
 295  * the server if so.  The actual change is detected elsewhere (by a software
 296  * interrupt on Unix); this just checks the flag and sends a message if
 297  * appropriate.
 298  */
 299
 300 static void
 301 client_check_window_change(void)
 302 {
 303         struct winsize ws;
 304
 305         if (! received_window_change_signal)
 306                 return;
 307         /** XXX race */
 308         received_window_change_signal = 0;
 309
 310         debug2("client_check_window_change: changed");
 311
 312         if (compat20) {
 313                 channel_send_window_changes();
 314         } else {
 315                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 316                         return;
 317                 packet_start(SSH_CMSG_WINDOW_SIZE);
 318                 packet_put_int(ws.ws_row);
 319                 packet_put_int(ws.ws_col);
 320                 packet_put_int(ws.ws_xpixel);
 321                 packet_put_int(ws.ws_ypixel);
 322                 packet_send();
 323         }
 324 }
 325
 326 static void
 327 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
 328 {
 329         server_alive_timeouts = 0;
 330         client_global_request_reply_fwd(type, seq, ctxt);
 331 }
 332
 333 static void
 334 server_alive_check(void)
 335 {
 336         if (++server_alive_timeouts > options.server_alive_count_max)
 337                 packet_disconnect("Timeout, server not responding.");
 338         packet_start(SSH2_MSG_GLOBAL_REQUEST);
 339         packet_put_cstring("keepalive@openssh.com");
 340         packet_put_char(1);     /* boolean: want reply */
 341         packet_send();
 342 }
 343
 344 /*
 345  * Waits until the client can do something (some data becomes available on
 346  * one of the file descriptors).
 347  */
 348 static void
 349 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 350     int *maxfdp, int *nallocp, int rekeying)
 351 {
 352         struct timeval tv, *tvp;
 353         int ret;
 354
 355         /* Add any selections by the channel mechanism. */
 356         channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
 357
 358         if (!compat20) {
 359                 /* Read from the connection, unless our buffers are full. */
 360                 if (buffer_len(&stdout_buffer) < buffer_high &&
 361                     buffer_len(&stderr_buffer) < buffer_high &&
 362                     channel_not_very_much_buffered_data())
 363                         FD_SET(connection_in, *readsetp);
 364                 /*
 365                  * Read from stdin, unless we have seen EOF or have very much
 366                  * buffered data to send to the server.
 367                  */
 368                 if (!stdin_eof && packet_not_very_much_data_to_write())
 369                         FD_SET(fileno(stdin), *readsetp);
 370
 371                 /* Select stdout/stderr if have data in buffer. */
 372                 if (buffer_len(&stdout_buffer) > 0)
 373                         FD_SET(fileno(stdout), *writesetp);
 374                 if (buffer_len(&stderr_buffer) > 0)
 375                         FD_SET(fileno(stderr), *writesetp);
 376         } else {
 377                 /* channel_prepare_select could have closed the last channel */
 378                 if (session_closed && !channel_still_open() &&
 379                     !packet_have_data_to_write()) {
 380                         /* clear mask since we did not call select() */
 381                         memset(*readsetp, 0, *nallocp);
 382                         memset(*writesetp, 0, *nallocp);
 383                         return;
 384                 } else {
 385                         FD_SET(connection_in, *readsetp);
 386                 }
 387         }
 388
 389         /* Select server connection if have data to write to the server. */
 390         if (packet_have_data_to_write())
 391                 FD_SET(connection_out, *writesetp);
 392
 393         if (control_fd != -1)
 394                 FD_SET(control_fd, *readsetp);
 395
 396         /*
 397          * Wait for something to happen.  This will suspend the process until
 398          * some selected descriptor can be read, written, or has some other
 399          * event pending.
 400          */
 401
 402         if (options.server_alive_interval == 0 || !compat20)
 403                 tvp = NULL;
 404         else {
 405                 tv.tv_sec = options.server_alive_interval;
 406                 tv.tv_usec = 0;
 407                 tvp = &tv;
 408         }
 409         ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 410         if (ret < 0) {
 411                 char buf[100];
 412
 413                 /*
 414                  * We have to clear the select masks, because we return.
 415                  * We have to return, because the mainloop checks for the flags
 416                  * set by the signal handlers.
 417                  */
 418                 memset(*readsetp, 0, *nallocp);
 419                 memset(*writesetp, 0, *nallocp);
 420
 421                 if (errno == EINTR)
 422                         return;
 423                 /* Note: we might still have data in the buffers. */
 424                 snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
 425                 buffer_append(&stderr_buffer, buf, strlen(buf));
 426                 quit_pending = 1;
 427         } else if (ret == 0)
 428                 server_alive_check();
 429 }
 430
 431 static void
 432 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 433 {
 434         struct winsize oldws, newws;
 435
 436         /* Flush stdout and stderr buffers. */
 437         if (buffer_len(bout) > 0)
 438                 atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
 439         if (buffer_len(berr) > 0)
 440                 atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
 441
 442         leave_raw_mode();
 443
 444         /*
 445          * Free (and clear) the buffer to reduce the amount of data that gets
 446          * written to swap.
 447          */
 448         buffer_free(bin);
 449         buffer_free(bout);
 450         buffer_free(berr);
 451
 452         /* Save old window size. */
 453         ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
 454
 455         /* Send the suspend signal to the program itself. */
 456         kill(getpid(), SIGTSTP);
 457
 458         /* Check if the window size has changed. */
 459         if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
 460             (oldws.ws_row != newws.ws_row ||
 461             oldws.ws_col != newws.ws_col ||
 462             oldws.ws_xpixel != newws.ws_xpixel ||
 463             oldws.ws_ypixel != newws.ws_ypixel))
 464                 received_window_change_signal = 1;
 465
 466         /* OK, we have been continued by the user. Reinitialize buffers. */
 467         buffer_init(bin);
 468         buffer_init(bout);
 469         buffer_init(berr);
 470
 471         enter_raw_mode();
 472 }
 473
 474 static void
 475 client_process_net_input(fd_set * readset)
 476 {
 477         int len;
 478         char buf[8192];
 479
 480         /*
 481          * Read input from the server, and add any such data to the buffer of
 482          * the packet subsystem.
 483          */
 484         if (FD_ISSET(connection_in, readset)) {
 485                 /* Read as much as possible. */
 486                 len = read(connection_in, buf, sizeof(buf));
 487                 if (len == 0) {
 488                         /* Received EOF.  The remote host has closed the connection. */
 489                         snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
 490                                  host);
 491                         buffer_append(&stderr_buffer, buf, strlen(buf));
 492                         quit_pending = 1;
 493                         return;
 494                 }
 495                 /*
 496                  * There is a kernel bug on Solaris that causes select to
 497                  * sometimes wake up even though there is no data available.
 498                  */
 499                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 500                         len = 0;
 501
 502                 if (len < 0) {
 503                         /* An error has encountered.  Perhaps there is a network problem. */
 504                         snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
 505                                  host, strerror(errno));
 506                         buffer_append(&stderr_buffer, buf, strlen(buf));
 507                         quit_pending = 1;
 508                         return;
 509                 }
 510                 packet_process_incoming(buf, len);
 511         }
 512 }
 513
 514 static void
 515 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
 516 {
 517         int id;
 518         Channel *c;
 519
 520         id = packet_get_int();
 521         packet_check_eom();
 522
 523         if ((c = channel_lookup(id)) == NULL) {
 524                 error("%s: no channel for id %d", __func__, id);
 525                 return;
 526         }
 527
 528         if (type == SSH2_MSG_CHANNEL_SUCCESS)
 529                 debug2("Request suceeded on channel %d", id);
 530         else if (type == SSH2_MSG_CHANNEL_FAILURE) {
 531                 error("Request failed on channel %d", id);
 532                 channel_free(c);
 533         }
 534 }
 535
 536 static void
 537 client_extra_session2_setup(int id, void *arg)
 538 {
 539         struct confirm_ctx *cctx = arg;
 540         Channel *c;
 541
 542         if (cctx == NULL)
 543                 fatal("%s: cctx == NULL", __func__);
 544         if ((c = channel_lookup(id)) == NULL)
 545                 fatal("%s: no channel for id %d", __func__, id);
 546
 547         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
 548             cctx->term, &cctx->tio, c->rfd, &cctx->cmd,
 549             client_subsystem_reply);
 550
 551         c->confirm_ctx = NULL;
 552         buffer_free(&cctx->cmd);
 553         free(cctx->term);
 554         free(cctx);
 555 }
 556
 557 static void
 558 client_process_control(fd_set * readset)
 559 {
 560         Buffer m;
 561         Channel *c;
 562         int client_fd, new_fd[3], ver;
 563         socklen_t addrlen;
 564         struct sockaddr_storage addr;
 565         struct confirm_ctx *cctx;
 566         char *cmd;
 567         u_int len;
 568         uid_t euid;
 569         gid_t egid;
 570
 571         /*
 572          * Accept connection on control socket
 573          */
 574         if (control_fd == -1 || !FD_ISSET(control_fd, readset))
 575                 return;
 576
 577         memset(&addr, 0, sizeof(addr));
 578         addrlen = sizeof(addr);
 579         if ((client_fd = accept(control_fd,
 580             (struct sockaddr*)&addr, &addrlen)) == -1) {
 581                 error("%s accept: %s", __func__, strerror(errno));
 582                 return;
 583         }
 584
 585         if (getpeereid(client_fd, &euid, &egid) < 0) {
 586                 error("%s getpeereid failed: %s", __func__, strerror(errno));
 587                 close(client_fd);
 588                 return;
 589         }
 590         if ((euid != 0) && (getuid() != euid)) {
 591                 error("control mode uid mismatch: peer euid %u != uid %u",
 592                     (u_int) euid, (u_int) getuid());
 593                 close(client_fd);
 594                 return;
 595         }
 596         /* XXX: implement use of ssh-askpass to confirm additional channels */
 597
 598         unset_nonblock(client_fd);
 599
 600         buffer_init(&m);
 601
 602         buffer_put_int(&m, getpid());
 603         if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
 604                 error("%s: client msg_send failed", __func__);
 605                 close(client_fd);
 606                 return;
 607         }
 608         buffer_clear(&m);
 609
 610         if (ssh_msg_recv(client_fd, &m) == -1) {
 611                 error("%s: client msg_recv failed", __func__);
 612                 close(client_fd);
 613                 return;
 614         }
 615
 616         if ((ver = buffer_get_char(&m)) != 0) {
 617                 error("%s: wrong client version %d", __func__, ver);
 618                 buffer_free(&m);
 619                 close(client_fd);
 620                 return;
 621         }
 622
 623         cctx = xmalloc(sizeof(*cctx));
 624         memset(cctx, 0, sizeof(*cctx));
 625
 626         cctx->want_tty = buffer_get_int(&m);
 627         cctx->want_subsys = buffer_get_int(&m);
 628         cctx->term = buffer_get_string(&m, &len);
 629
 630         cmd = buffer_get_string(&m, &len);
 631         buffer_init(&cctx->cmd);
 632         buffer_append(&cctx->cmd, cmd, strlen(cmd));
 633
 634         debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
 635             cctx->want_tty, cctx->want_subsys, cmd);
 636
 637         /* Gather fds from client */
 638         new_fd[0] = mm_receive_fd(client_fd);
 639         new_fd[1] = mm_receive_fd(client_fd);
 640         new_fd[2] = mm_receive_fd(client_fd);
 641
 642         debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
 643             new_fd[0], new_fd[1], new_fd[2]);
 644
 645         /* Try to pick up ttymodes from client before it goes raw */
 646         if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
 647                 error("%s: tcgetattr: %s", __func__, strerror(errno));
 648
 649         buffer_clear(&m);
 650         if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
 651                 error("%s: client msg_send failed", __func__);
 652                 close(client_fd);
 653                 close(new_fd[0]);
 654                 close(new_fd[1]);
 655                 close(new_fd[2]);
 656                 return;
 657         }
 658         buffer_free(&m);
 659
 660         /* enable nonblocking unless tty */
 661         if (!isatty(new_fd[0]))
 662                 set_nonblock(new_fd[0]);
 663         if (!isatty(new_fd[1]))
 664                 set_nonblock(new_fd[1]);
 665         if (!isatty(new_fd[2]))
 666                 set_nonblock(new_fd[2]);
 667
 668         set_nonblock(client_fd);
 669
 670         c = channel_new("session", SSH_CHANNEL_OPENING,
 671             new_fd[0], new_fd[1], new_fd[2],
 672             CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
 673             CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 674
 675         /* XXX */
 676         c->ctl_fd = client_fd;
 677
 678         debug3("%s: channel_new: %d", __func__, c->self);
 679
 680         channel_send_open(c->self);
 681         channel_register_confirm(c->self, client_extra_session2_setup, cctx);
 682 }
 683
 684 static void
 685 process_cmdline(void)
 686 {
 687         void (*handler)(int);
 688         char *s, *cmd;
 689         u_short fwd_port, fwd_host_port;
 690         char buf[1024], sfwd_port[6], sfwd_host_port[6];
 691         int delete = 0;
 692         int local = 0;
 693
 694         leave_raw_mode();
 695         handler = signal(SIGINT, SIG_IGN);
 696         cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
 697         if (s == NULL)
 698                 goto out;
 699         while (*s && isspace(*s))
 700                 s++;
 701         if (*s == '-')
 702                 s++;    /* Skip cmdline '-', if any */
 703         if (*s == '\0')
 704                 goto out;
 705
 706         if (*s == 'h' || *s == 'H' || *s == '?') {
 707                 logit("Commands:");
 708                 logit("      -Lport:host:hostport    Request local forward");
 709                 logit("      -Rport:host:hostport    Request remote forward");
 710                 logit("      -KRhostport             Cancel remote forward");
 711                 goto out;
 712         }
 713
 714         if (*s == 'K') {
 715                 delete = 1;
 716                 s++;
 717         }
 718         if (*s != 'L' && *s != 'R') {
 719                 logit("Invalid command.");
 720                 goto out;
 721         }
 722         if (*s == 'L')
 723                 local = 1;
 724         if (local && delete) {
 725                 logit("Not supported.");
 726                 goto out;
 727         }
 728         if ((!local || delete) && !compat20) {
 729                 logit("Not supported for SSH protocol version 1.");
 730                 goto out;
 731         }
 732
 733         s++;
 734         while (*s && isspace(*s))
 735                 s++;
 736
 737         if (delete) {
 738                 if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
 739                         logit("Bad forwarding specification.");
 740                         goto out;
 741                 }
 742                 if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
 743                         logit("Bad forwarding port(s).");
 744                         goto out;
 745                 }
 746                 channel_request_rforward_cancel(fwd_host_port);
 747         } else {
 748                 if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
 749                     sfwd_port, buf, sfwd_host_port) != 3 &&
 750                     sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
 751                     sfwd_port, buf, sfwd_host_port) != 3) {
 752                         logit("Bad forwarding specification.");
 753                         goto out;
 754                 }
 755                 if ((fwd_port = a2port(sfwd_port)) == 0 ||
 756                     (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 757                         logit("Bad forwarding port(s).");
 758                         goto out;
 759                 }
 760                 if (local) {
 761                         if (channel_setup_local_fwd_listener(fwd_port, buf,
 762                             fwd_host_port, options.gateway_ports) < 0) {
 763                                 logit("Port forwarding failed.");
 764                                 goto out;
 765                         }
 766                 } else
 767                         channel_request_remote_forwarding(fwd_port, buf,
 768                             fwd_host_port);
 769                 logit("Forwarding port.");
 770         }
 771
 772 out:
 773         signal(SIGINT, handler);
 774         enter_raw_mode();
 775         if (cmd)
 776                 xfree(cmd);
 777 }
 778
 779 /* process the characters one by one */
 780 static int
 781 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
 782 {
 783         char string[1024];
 784         pid_t pid;
 785         int bytes = 0;
 786         u_int i;
 787         u_char ch;
 788         char *s;
 789
 790         for (i = 0; i < len; i++) {
 791                 /* Get one character at a time. */
 792                 ch = buf[i];
 793
 794                 if (escape_pending) {
 795                         /* We have previously seen an escape character. */
 796                         /* Clear the flag now. */
 797                         escape_pending = 0;
 798
 799                         /* Process the escaped character. */
 800                         switch (ch) {
 801                         case '.':
 802                                 /* Terminate the connection. */
 803                                 snprintf(string, sizeof string, "%c.\r\n", escape_char);
 804                                 buffer_append(berr, string, strlen(string));
 805
 806                                 quit_pending = 1;
 807                                 return -1;
 808
 809                         case 'Z' - 64:
 810                                 /* Suspend the program. */
 811                                 /* Print a message to that effect to the user. */
 812                                 snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
 813                                 buffer_append(berr, string, strlen(string));
 814
 815                                 /* Restore terminal modes and suspend. */
 816                                 client_suspend_self(bin, bout, berr);
 817
 818                                 /* We have been continued. */
 819                                 continue;
 820
 821                         case 'B':
 822                                 if (compat20) {
 823                                         snprintf(string, sizeof string,
 824                                             "%cB\r\n", escape_char);
 825                                         buffer_append(berr, string,
 826                                             strlen(string));
 827                                         channel_request_start(session_ident,
 828                                             "break", 0);
 829                                         packet_put_int(1000);
 830                                         packet_send();
 831                                 }
 832                                 continue;
 833
 834                         case 'R':
 835                                 if (compat20) {
 836                                         if (datafellows & SSH_BUG_NOREKEY)
 837                                                 logit("Server does not support re-keying");
 838                                         else
 839                                                 need_rekeying = 1;
 840                                 }
 841                                 continue;
 842
 843                         case '&':
 844                                 /*
 845                                  * Detach the program (continue to serve connections,
 846                                  * but put in background and no more new connections).
 847                                  */
 848                                 /* Restore tty modes. */
 849                                 leave_raw_mode();
 850
 851                                 /* Stop listening for new connections. */
 852                                 channel_stop_listening();
 853
 854                                 snprintf(string, sizeof string,
 855                                     "%c& [backgrounded]\n", escape_char);
 856                                 buffer_append(berr, string, strlen(string));
 857
 858                                 /* Fork into background. */
 859                                 pid = fork();
 860                                 if (pid < 0) {
 861                                         error("fork: %.100s", strerror(errno));
 862                                         continue;
 863                                 }
 864                                 if (pid != 0) { /* This is the parent. */
 865                                         /* The parent just exits. */
 866                                         exit(0);
 867                                 }
 868                                 /* The child continues serving connections. */
 869                                 if (compat20) {
 870                                         buffer_append(bin, "\004", 1);
 871                                         /* fake EOF on stdin */
 872                                         return -1;
 873                                 } else if (!stdin_eof) {
 874                                         /*
 875                                          * Sending SSH_CMSG_EOF alone does not always appear
 876                                          * to be enough.  So we try to send an EOF character
 877                                          * first.
 878                                          */
 879                                         packet_start(SSH_CMSG_STDIN_DATA);
 880                                         packet_put_string("\004", 1);
 881                                         packet_send();
 882                                         /* Close stdin. */
 883                                         stdin_eof = 1;
 884                                         if (buffer_len(bin) == 0) {
 885                                                 packet_start(SSH_CMSG_EOF);
 886                                                 packet_send();
 887                                         }
 888                                 }
 889                                 continue;
 890
 891                         case '?':
 892                                 snprintf(string, sizeof string,
 893 "%c?\r\n\
 894 Supported escape sequences:\r\n\
 895 %c.  - terminate connection\r\n\
 896 %cB  - send a BREAK to the remote system\r\n\
 897 %cC  - open a command line\r\n\
 898 %cR  - Request rekey (SSH protocol 2 only)\r\n\
 899 %c^Z - suspend ssh\r\n\
 900 %c#  - list forwarded connections\r\n\
 901 %c&  - background ssh (when waiting for connections to terminate)\r\n\
 902 %c?  - this message\r\n\
 903 %c%c  - send the escape character by typing it twice\r\n\
 904 (Note that escapes are only recognized immediately after newline.)\r\n",
 905                                     escape_char, escape_char, escape_char, escape_char,
 906                                     escape_char, escape_char, escape_char, escape_char,
 907                                     escape_char, escape_char, escape_char);
 908                                 buffer_append(berr, string, strlen(string));
 909                                 continue;
 910
 911                         case '#':
 912                                 snprintf(string, sizeof string, "%c#\r\n", escape_char);
 913                                 buffer_append(berr, string, strlen(string));
 914                                 s = channel_open_message();
 915                                 buffer_append(berr, s, strlen(s));
 916                                 xfree(s);
 917                                 continue;
 918
 919                         case 'C':
 920                                 process_cmdline();
 921                                 continue;
 922
 923                         default:
 924                                 if (ch != escape_char) {
 925                                         buffer_put_char(bin, escape_char);
 926                                         bytes++;
 927                                 }
 928                                 /* Escaped characters fall through here */
 929                                 break;
 930                         }
 931                 } else {
 932                         /*
 933                          * The previous character was not an escape char. Check if this
 934                          * is an escape.
 935                          */
 936                         if (last_was_cr && ch == escape_char) {
 937                                 /* It is. Set the flag and continue to next character. */
 938                                 escape_pending = 1;
 939                                 continue;
 940                         }
 941                 }
 942
 943                 /*
 944                  * Normal character.  Record whether it was a newline,
 945                  * and append it to the buffer.
 946                  */
 947                 last_was_cr = (ch == '\r' || ch == '\n');
 948                 buffer_put_char(bin, ch);
 949                 bytes++;
 950         }
 951         return bytes;
 952 }
 953
 954 static void
 955 client_process_input(fd_set * readset)
 956 {
 957         int len;
 958         char buf[8192];
 959
 960         /* Read input from stdin. */
 961         if (FD_ISSET(fileno(stdin), readset)) {
 962                 /* Read as much as possible. */
 963                 len = read(fileno(stdin), buf, sizeof(buf));
 964                 if (len < 0 && (errno == EAGAIN || errno == EINTR))
 965                         return;         /* we'll try again later */
 966                 if (len <= 0) {
 967                         /*
 968                          * Received EOF or error.  They are treated
 969                          * similarly, except that an error message is printed
 970                          * if it was an error condition.
 971                          */
 972                         if (len < 0) {
 973                                 snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
 974                                 buffer_append(&stderr_buffer, buf, strlen(buf));
 975                         }
 976                         /* Mark that we have seen EOF. */
 977                         stdin_eof = 1;
 978                         /*
 979                          * Send an EOF message to the server unless there is
 980                          * data in the buffer.  If there is data in the
 981                          * buffer, no message will be sent now.  Code
 982                          * elsewhere will send the EOF when the buffer
 983                          * becomes empty if stdin_eof is set.
 984                          */
 985                         if (buffer_len(&stdin_buffer) == 0) {
 986                                 packet_start(SSH_CMSG_EOF);
 987                                 packet_send();
 988                         }
 989                 } else if (escape_char == SSH_ESCAPECHAR_NONE) {
 990                         /*
 991                          * Normal successful read, and no escape character.
 992                          * Just append the data to buffer.
 993                          */
 994                         buffer_append(&stdin_buffer, buf, len);
 995                 } else {
 996                         /*
 997                          * Normal, successful read.  But we have an escape character
 998                          * and have to process the characters one by one.
 999                          */
1000                         if (process_escapes(&stdin_buffer, &stdout_buffer,
1001                             &stderr_buffer, buf, len) == -1)
1002                                 return;
1003                 }
1004         }
1005 }
1006
1007 static void
1008 client_process_output(fd_set * writeset)
1009 {
1010         int len;
1011         char buf[100];
1012
1013         /* Write buffered output to stdout. */
1014         if (FD_ISSET(fileno(stdout), writeset)) {
1015                 /* Write as much data as possible. */
1016                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1017                     buffer_len(&stdout_buffer));
1018                 if (len <= 0) {
1019                         if (errno == EINTR || errno == EAGAIN)
1020                                 len = 0;
1021                         else {
1022                                 /*
1023                                  * An error or EOF was encountered.  Put an
1024                                  * error message to stderr buffer.
1025                                  */
1026                                 snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
1027                                 buffer_append(&stderr_buffer, buf, strlen(buf));
1028                                 quit_pending = 1;
1029                                 return;
1030                         }
1031                 }
1032                 /* Consume printed data from the buffer. */
1033                 buffer_consume(&stdout_buffer, len);
1034                 stdout_bytes += len;
1035         }
1036         /* Write buffered output to stderr. */
1037         if (FD_ISSET(fileno(stderr), writeset)) {
1038                 /* Write as much data as possible. */
1039                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1040                     buffer_len(&stderr_buffer));
1041                 if (len <= 0) {
1042                         if (errno == EINTR || errno == EAGAIN)
1043                                 len = 0;
1044                         else {
1045                                 /* EOF or error, but can't even print error message. */
1046                                 quit_pending = 1;
1047                                 return;
1048                         }
1049                 }
1050                 /* Consume printed characters from the buffer. */
1051                 buffer_consume(&stderr_buffer, len);
1052                 stderr_bytes += len;
1053         }
1054 }
1055
1056 /*
1057  * Get packets from the connection input buffer, and process them as long as
1058  * there are packets available.
1059  *
1060  * Any unknown packets received during the actual
1061  * session cause the session to terminate.  This is
1062  * intended to make debugging easier since no
1063  * confirmations are sent.  Any compatible protocol
1064  * extensions must be negotiated during the
1065  * preparatory phase.
1066  */
1067
1068 static void
1069 client_process_buffered_input_packets(void)
1070 {
1071         dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
1072 }
1073
1074 /* scan buf[] for '~' before sending data to the peer */
1075
1076 static int
1077 simple_escape_filter(Channel *c, char *buf, int len)
1078 {
1079         /* XXX we assume c->extended is writeable */
1080         return process_escapes(&c->input, &c->output, &c->extended, buf, len);
1081 }
1082
1083 static void
1084 client_channel_closed(int id, void *arg)
1085 {
1086         channel_cancel_cleanup(id);
1087         session_closed = 1;
1088         leave_raw_mode();
1089 }
1090
1091 /*
1092  * Implements the interactive session with the server.  This is called after
1093  * the user has been authenticated, and a command has been started on the
1094  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1095  * used as an escape character for terminating or suspending the session.
1096  */
1097
1098 int
1099 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1100 {
1101         fd_set *readset = NULL, *writeset = NULL;
1102         double start_time, total_time;
1103         int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
1104         char buf[100];
1105
1106         debug("Entering interactive session.");
1107
1108         start_time = get_current_time();
1109
1110         /* Initialize variables. */
1111         escape_pending = 0;
1112         last_was_cr = 1;
1113         exit_status = -1;
1114         stdin_eof = 0;
1115         buffer_high = 64 * 1024;
1116         connection_in = packet_get_connection_in();
1117         connection_out = packet_get_connection_out();
1118         max_fd = MAX(connection_in, connection_out);
1119         if (control_fd != -1)
1120                 max_fd = MAX(max_fd, control_fd);
1121
1122         if (!compat20) {
1123                 /* enable nonblocking unless tty */
1124                 if (!isatty(fileno(stdin)))
1125                         set_nonblock(fileno(stdin));
1126                 if (!isatty(fileno(stdout)))
1127                         set_nonblock(fileno(stdout));
1128                 if (!isatty(fileno(stderr)))
1129                         set_nonblock(fileno(stderr));
1130                 max_fd = MAX(max_fd, fileno(stdin));
1131                 max_fd = MAX(max_fd, fileno(stdout));
1132                 max_fd = MAX(max_fd, fileno(stderr));
1133         }
1134         stdin_bytes = 0;
1135         stdout_bytes = 0;
1136         stderr_bytes = 0;
1137         quit_pending = 0;
1138         escape_char = escape_char_arg;
1139
1140         /* Initialize buffers. */
1141         buffer_init(&stdin_buffer);
1142         buffer_init(&stdout_buffer);
1143         buffer_init(&stderr_buffer);
1144
1145         client_init_dispatch();
1146
1147         /*
1148          * Set signal handlers, (e.g. to restore non-blocking mode)
1149          * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1150          */
1151         if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1152                 signal(SIGINT, signal_handler);
1153         if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1154                 signal(SIGQUIT, signal_handler);
1155         if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1156                 signal(SIGTERM, signal_handler);
1157         if (have_pty)
1158                 signal(SIGWINCH, window_change_handler);
1159
1160         if (have_pty)
1161                 enter_raw_mode();
1162
1163         if (compat20) {
1164                 session_ident = ssh2_chan_id;
1165                 if (escape_char != SSH_ESCAPECHAR_NONE)
1166                         channel_register_filter(session_ident,
1167                             simple_escape_filter);
1168                 if (session_ident != -1)
1169                         channel_register_cleanup(session_ident,
1170                             client_channel_closed);
1171         } else {
1172                 /* Check if we should immediately send eof on stdin. */
1173                 client_check_initial_eof_on_stdin();
1174         }
1175
1176         /* Main loop of the client for the interactive session mode. */
1177         while (!quit_pending) {
1178
1179                 /* Process buffered packets sent by the server. */
1180                 client_process_buffered_input_packets();
1181
1182                 if (compat20 && session_closed && !channel_still_open())
1183                         break;
1184
1185                 rekeying = (xxx_kex != NULL && !xxx_kex->done);
1186
1187                 if (rekeying) {
1188                         debug("rekeying in progress");
1189                 } else {
1190                         /*
1191                          * Make packets of buffered stdin data, and buffer
1192                          * them for sending to the server.
1193                          */
1194                         if (!compat20)
1195                                 client_make_packets_from_stdin_data();
1196
1197                         /*
1198                          * Make packets from buffered channel data, and
1199                          * enqueue them for sending to the server.
1200                          */
1201                         if (packet_not_very_much_data_to_write())
1202                                 channel_output_poll();
1203
1204                         /*
1205                          * Check if the window size has changed, and buffer a
1206                          * message about it to the server if so.
1207                          */
1208                         client_check_window_change();
1209
1210                         if (quit_pending)
1211                                 break;
1212                 }
1213                 /*
1214                  * Wait until we have something to do (something becomes
1215                  * available on one of the descriptors).
1216                  */
1217                 max_fd2 = max_fd;
1218                 client_wait_until_can_do_something(&readset, &writeset,
1219                     &max_fd2, &nalloc, rekeying);
1220
1221                 if (quit_pending)
1222                         break;
1223
1224                 /* Do channel operations unless rekeying in progress. */
1225                 if (!rekeying) {
1226                         channel_after_select(readset, writeset);
1227                         if (need_rekeying || packet_need_rekeying()) {
1228                                 debug("need rekeying");
1229                                 xxx_kex->done = 0;
1230                                 kex_send_kexinit(xxx_kex);
1231                                 need_rekeying = 0;
1232                         }
1233                 }
1234
1235                 /* Buffer input from the connection.  */
1236                 client_process_net_input(readset);
1237
1238                 /* Accept control connections.  */
1239                 client_process_control(readset);
1240
1241                 if (quit_pending)
1242                         break;
1243
1244                 if (!compat20) {
1245                         /* Buffer data from stdin */
1246                         client_process_input(readset);
1247                         /*
1248                          * Process output to stdout and stderr.  Output to
1249                          * the connection is processed elsewhere (above).
1250                          */
1251                         client_process_output(writeset);
1252                 }
1253
1254                 /* Send as much buffered packet data as possible to the sender. */
1255                 if (FD_ISSET(connection_out, writeset))
1256                         packet_write_poll();
1257         }
1258         if (readset)
1259                 xfree(readset);
1260         if (writeset)
1261                 xfree(writeset);
1262
1263         /* Terminate the session. */
1264
1265         /* Stop watching for window change. */
1266         if (have_pty)
1267                 signal(SIGWINCH, SIG_DFL);
1268
1269         channel_free_all();
1270
1271         if (have_pty)
1272                 leave_raw_mode();
1273
1274         /* restore blocking io */
1275         if (!isatty(fileno(stdin)))
1276                 unset_nonblock(fileno(stdin));
1277         if (!isatty(fileno(stdout)))
1278                 unset_nonblock(fileno(stdout));
1279         if (!isatty(fileno(stderr)))
1280                 unset_nonblock(fileno(stderr));
1281
1282         /*
1283          * If there was no shell or command requested, there will be no remote
1284          * exit status to be returned.  In that case, clear error code if the
1285          * connection was deliberately terminated at this end.
1286          */
1287         if (no_shell_flag && received_signal == SIGTERM) {
1288                 received_signal = 0;
1289                 exit_status = 0;
1290         }
1291
1292         if (received_signal)
1293                 fatal("Killed by signal %d.", (int) received_signal);
1294
1295         /*
1296          * In interactive mode (with pseudo tty) display a message indicating
1297          * that the connection has been closed.
1298          */
1299         if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1300                 snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1301                 buffer_append(&stderr_buffer, buf, strlen(buf));
1302         }
1303
1304         /* Output any buffered data for stdout. */
1305         while (buffer_len(&stdout_buffer) > 0) {
1306                 len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1307                     buffer_len(&stdout_buffer));
1308                 if (len <= 0) {
1309                         error("Write failed flushing stdout buffer.");
1310                         break;
1311                 }
1312                 buffer_consume(&stdout_buffer, len);
1313                 stdout_bytes += len;
1314         }
1315
1316         /* Output any buffered data for stderr. */
1317         while (buffer_len(&stderr_buffer) > 0) {
1318                 len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1319                     buffer_len(&stderr_buffer));
1320                 if (len <= 0) {
1321                         error("Write failed flushing stderr buffer.");
1322                         break;
1323                 }
1324                 buffer_consume(&stderr_buffer, len);
1325                 stderr_bytes += len;
1326         }
1327
1328         /* Clear and free any buffers. */
1329         memset(buf, 0, sizeof(buf));
1330         buffer_free(&stdin_buffer);
1331         buffer_free(&stdout_buffer);
1332         buffer_free(&stderr_buffer);
1333
1334         /* Report bytes transferred, and transfer rates. */
1335         total_time = get_current_time() - start_time;
1336         debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1337             stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1338         if (total_time > 0)
1339                 debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1340                     stdin_bytes / total_time, stdout_bytes / total_time,
1341                     stderr_bytes / total_time);
1342
1343         /* Return the exit status of the program. */
1344         debug("Exit status %d", exit_status);
1345         return exit_status;
1346 }
1347
1348 /*********/
1349
1350 static void
1351 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1352 {
1353         u_int data_len;
1354         char *data = packet_get_string(&data_len);
1355         packet_check_eom();
1356         buffer_append(&stdout_buffer, data, data_len);
1357         memset(data, 0, data_len);
1358         xfree(data);
1359 }
1360 static void
1361 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1362 {
1363         u_int data_len;
1364         char *data = packet_get_string(&data_len);
1365         packet_check_eom();
1366         buffer_append(&stderr_buffer, data, data_len);
1367         memset(data, 0, data_len);
1368         xfree(data);
1369 }
1370 static void
1371 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1372 {
1373         exit_status = packet_get_int();
1374         packet_check_eom();
1375         /* Acknowledge the exit. */
1376         packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1377         packet_send();
1378         /*
1379          * Must wait for packet to be sent since we are
1380          * exiting the loop.
1381          */
1382         packet_write_wait();
1383         /* Flag that we want to exit. */
1384         quit_pending = 1;
1385 }
1386 static void
1387 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1388 {
1389         Channel *c = NULL;
1390         int remote_id, sock;
1391
1392         /* Read the remote channel number from the message. */
1393         remote_id = packet_get_int();
1394         packet_check_eom();
1395
1396         /*
1397          * Get a connection to the local authentication agent (this may again
1398          * get forwarded).
1399          */
1400         sock = ssh_get_authentication_socket();
1401
1402         /*
1403          * If we could not connect the agent, send an error message back to
1404          * the server. This should never happen unless the agent dies,
1405          * because authentication forwarding is only enabled if we have an
1406          * agent.
1407          */
1408         if (sock >= 0) {
1409                 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1410                     -1, 0, 0, 0, "authentication agent connection", 1);
1411                 c->remote_id = remote_id;
1412                 c->force_drain = 1;
1413         }
1414         if (c == NULL) {
1415                 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1416                 packet_put_int(remote_id);
1417         } else {
1418                 /* Send a confirmation to the remote host. */
1419                 debug("Forwarding authentication connection.");
1420                 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1421                 packet_put_int(remote_id);
1422                 packet_put_int(c->self);
1423         }
1424         packet_send();
1425 }
1426
1427 static Channel *
1428 client_request_forwarded_tcpip(const char *request_type, int rchan)
1429 {
1430         Channel *c = NULL;
1431         char *listen_address, *originator_address;
1432         int listen_port, originator_port;
1433         int sock;
1434
1435         /* Get rest of the packet */
1436         listen_address = packet_get_string(NULL);
1437         listen_port = packet_get_int();
1438         originator_address = packet_get_string(NULL);
1439         originator_port = packet_get_int();
1440         packet_check_eom();
1441
1442         debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1443             listen_address, listen_port, originator_address, originator_port);
1444
1445         sock = channel_connect_by_listen_address(listen_port);
1446         if (sock < 0) {
1447                 xfree(originator_address);
1448                 xfree(listen_address);
1449                 return NULL;
1450         }
1451         c = channel_new("forwarded-tcpip",
1452             SSH_CHANNEL_CONNECTING, sock, sock, -1,
1453             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1454             originator_address, 1);
1455         xfree(originator_address);
1456         xfree(listen_address);
1457         return c;
1458 }
1459
1460 static Channel *
1461 client_request_x11(const char *request_type, int rchan)
1462 {
1463         Channel *c = NULL;
1464         char *originator;
1465         int originator_port;
1466         int sock;
1467
1468         if (!options.forward_x11) {
1469                 error("Warning: ssh server tried X11 forwarding.");
1470                 error("Warning: this is probably a break in attempt by a malicious server.");
1471                 return NULL;
1472         }
1473         originator = packet_get_string(NULL);
1474         if (datafellows & SSH_BUG_X11FWD) {
1475                 debug2("buggy server: x11 request w/o originator_port");
1476                 originator_port = 0;
1477         } else {
1478                 originator_port = packet_get_int();
1479         }
1480         packet_check_eom();
1481         /* XXX check permission */
1482         debug("client_request_x11: request from %s %d", originator,
1483             originator_port);
1484         xfree(originator);
1485         sock = x11_connect_display();
1486         if (sock < 0)
1487                 return NULL;
1488         c = channel_new("x11",
1489             SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1490             CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1491         c->force_drain = 1;
1492         return c;
1493 }
1494
1495 static Channel *
1496 client_request_agent(const char *request_type, int rchan)
1497 {
1498         Channel *c = NULL;
1499         int sock;
1500
1501         if (!options.forward_agent) {
1502                 error("Warning: ssh server tried agent forwarding.");
1503                 error("Warning: this is probably a break in attempt by a malicious server.");
1504                 return NULL;
1505         }
1506         sock =  ssh_get_authentication_socket();
1507         if (sock < 0)
1508                 return NULL;
1509         c = channel_new("authentication agent connection",
1510             SSH_CHANNEL_OPEN, sock, sock, -1,
1511             CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1512             "authentication agent connection", 1);
1513         c->force_drain = 1;
1514         return c;
1515 }
1516
1517 /* XXXX move to generic input handler */
1518 static void
1519 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1520 {
1521         Channel *c = NULL;
1522         char *ctype;
1523         int rchan;
1524         u_int rmaxpack, rwindow, len;
1525
1526         ctype = packet_get_string(&len);
1527         rchan = packet_get_int();
1528         rwindow = packet_get_int();
1529         rmaxpack = packet_get_int();
1530
1531         debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1532             ctype, rchan, rwindow, rmaxpack);
1533
1534         if (strcmp(ctype, "forwarded-tcpip") == 0) {
1535                 c = client_request_forwarded_tcpip(ctype, rchan);
1536         } else if (strcmp(ctype, "x11") == 0) {
1537                 c = client_request_x11(ctype, rchan);
1538         } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1539                 c = client_request_agent(ctype, rchan);
1540         }
1541 /* XXX duplicate : */
1542         if (c != NULL) {
1543                 debug("confirm %s", ctype);
1544                 c->remote_id = rchan;
1545                 c->remote_window = rwindow;
1546                 c->remote_maxpacket = rmaxpack;
1547                 if (c->type != SSH_CHANNEL_CONNECTING) {
1548                         packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1549                         packet_put_int(c->remote_id);
1550                         packet_put_int(c->self);
1551                         packet_put_int(c->local_window);
1552                         packet_put_int(c->local_maxpacket);
1553                         packet_send();
1554                 }
1555         } else {
1556                 debug("failure %s", ctype);
1557                 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1558                 packet_put_int(rchan);
1559                 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1560                 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1561                         packet_put_cstring("open failed");
1562                         packet_put_cstring("");
1563                 }
1564                 packet_send();
1565         }
1566         xfree(ctype);
1567 }
1568 static void
1569 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1570 {
1571         Channel *c = NULL;
1572         int exitval, id, reply, success = 0;
1573         char *rtype;
1574
1575         id = packet_get_int();
1576         rtype = packet_get_string(NULL);
1577         reply = packet_get_char();
1578
1579         debug("client_input_channel_req: channel %d rtype %s reply %d",
1580             id, rtype, reply);
1581
1582         c = channel_lookup(id);
1583         if (c == NULL) {
1584                 error("client_input_channel_req: channel %d: unknown channel", id);
1585         } else if (strcmp(rtype, "exit-status") == 0) {
1586                 exitval = packet_get_int();
1587                 if (id == session_ident) {
1588                         success = 1;
1589                         exit_status = exitval;
1590                 } else if (c->ctl_fd == -1) {
1591                         error("client_input_channel_req: unexpected channel %d",
1592                             session_ident);
1593                 } else {
1594                         atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
1595                         success = 1;
1596                 }
1597                 packet_check_eom();
1598         }
1599         if (reply) {
1600                 packet_start(success ?
1601                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1602                 packet_put_int(c->remote_id);
1603                 packet_send();
1604         }
1605         xfree(rtype);
1606 }
1607 static void
1608 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1609 {
1610         char *rtype;
1611         int want_reply;
1612         int success = 0;
1613
1614         rtype = packet_get_string(NULL);
1615         want_reply = packet_get_char();
1616         debug("client_input_global_request: rtype %s want_reply %d",
1617             rtype, want_reply);
1618         if (want_reply) {
1619                 packet_start(success ?
1620                     SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1621                 packet_send();
1622                 packet_write_wait();
1623         }
1624         xfree(rtype);
1625 }
1626
1627 void
1628 client_session2_setup(int id, int want_tty, int want_subsystem,
1629     const char *term, struct termios *tiop, int in_fd, Buffer *cmd,
1630     dispatch_fn *subsys_repl)
1631 {
1632         int len;
1633
1634         debug2("%s: id %d", __func__, id);
1635
1636         if (want_tty) {
1637                 struct winsize ws;
1638                 struct termios tio;
1639
1640                 /* Store window size in the packet. */
1641                 if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1642                         memset(&ws, 0, sizeof(ws));
1643
1644                 channel_request_start(id, "pty-req", 0);
1645                 packet_put_cstring(term != NULL ? term : "");
1646                 packet_put_int(ws.ws_col);
1647                 packet_put_int(ws.ws_row);
1648                 packet_put_int(ws.ws_xpixel);
1649                 packet_put_int(ws.ws_ypixel);
1650                 tio = get_saved_tio();
1651                 tty_make_modes(-1, tiop != NULL ? tiop : &tio);
1652                 packet_send();
1653                 /* XXX wait for reply */
1654         }
1655
1656         /* Transfer any environment variables from client to server */
1657         if (options.num_send_env != 0) {
1658                 int i, j, matched;
1659                 extern char **environ;
1660                 char *name, *val;
1661
1662                 debug("Sending environment.");
1663                 for (i = 0; environ && environ[i] != NULL; i++) {
1664                         /* Split */
1665                         name = xstrdup(environ[i]);
1666                         if ((val = strchr(name, '=')) == NULL) {
1667                                 free(name);
1668                                 continue;
1669                         }
1670                         *val++ = '\0';
1671
1672                         matched = 0;
1673                         for (j = 0; j < options.num_send_env; j++) {
1674                                 if (match_pattern(name, options.send_env[j])) {
1675                                         matched = 1;
1676                                         break;
1677                                 }
1678                         }
1679                         if (!matched) {
1680                                 debug3("Ignored env %s", name);
1681                                 free(name);
1682                                 continue;
1683                         }
1684
1685                         debug("Sending env %s = %s", name, val);
1686                         channel_request_start(id, "env", 0);
1687                         packet_put_cstring(name);
1688                         packet_put_cstring(val);
1689                         packet_send();
1690                         free(name);
1691                 }
1692         }
1693
1694         len = buffer_len(cmd);
1695         if (len > 0) {
1696                 if (len > 900)
1697                         len = 900;
1698                 if (want_subsystem) {
1699                         debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
1700                         channel_request_start(id, "subsystem", subsys_repl != NULL);
1701                         if (subsys_repl != NULL) {
1702                                 /* register callback for reply */
1703                                 /* XXX we assume that client_loop has already been called */
1704                                 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
1705                                 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
1706                         }
1707                 } else {
1708                         debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
1709                         channel_request_start(id, "exec", 0);
1710                 }
1711                 packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
1712                 packet_send();
1713         } else {
1714                 channel_request_start(id, "shell", 0);
1715                 packet_send();
1716         }
1717 }
1718
1719 static void
1720 client_init_dispatch_20(void)
1721 {
1722         dispatch_init(&dispatch_protocol_error);
1723
1724         dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1725         dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1726         dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1727         dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1728         dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1729         dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1730         dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1731         dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1732         dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1733         dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1734
1735         /* rekeying */
1736         dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1737
1738         /* global request reply messages */
1739         dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1740         dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1741 }
1742 static void
1743 client_init_dispatch_13(void)
1744 {
1745         dispatch_init(NULL);
1746         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1747         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1748         dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1749         dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1750         dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1751         dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1752         dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1753         dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1754         dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1755
1756         dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1757             &client_input_agent_open : &deny_input_open);
1758         dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1759             &x11_input_open : &deny_input_open);
1760 }
1761 static void
1762 client_init_dispatch_15(void)
1763 {
1764         client_init_dispatch_13();
1765         dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1766         dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1767 }
1768 static void
1769 client_init_dispatch(void)
1770 {
1771         if (compat20)
1772                 client_init_dispatch_20();
1773         else if (compat13)
1774                 client_init_dispatch_13();
1775         else
1776                 client_init_dispatch_15();
1777 }
1778
1779 /* client specific fatal cleanup */
1780 void
1781 cleanup_exit(int i)
1782 {
1783         leave_raw_mode();
1784         leave_non_blocking();
1785         if (options.control_path != NULL && control_fd != -1)
1786                 unlink(options.control_path);
1787         _exit(i);
1788 }