xref: /freebsd/crypto/openssh/clientloop.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
1 /* $OpenBSD: clientloop.c,v 1.222 2010/07/19 09:15:12 djm 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 "openbsd-compat/sys-queue.h"
90 #include "xmalloc.h"
91 #include "ssh.h"
92 #include "ssh1.h"
93 #include "ssh2.h"
94 #include "packet.h"
95 #include "buffer.h"
96 #include "compat.h"
97 #include "channels.h"
98 #include "dispatch.h"
99 #include "key.h"
100 #include "cipher.h"
101 #include "kex.h"
102 #include "log.h"
103 #include "readconf.h"
104 #include "clientloop.h"
105 #include "sshconnect.h"
106 #include "authfd.h"
107 #include "atomicio.h"
108 #include "sshpty.h"
109 #include "misc.h"
110 #include "match.h"
111 #include "msg.h"
112 #include "roaming.h"
113 
114 /* import options */
115 extern Options options;
116 
117 /* Flag indicating that stdin should be redirected from /dev/null. */
118 extern int stdin_null_flag;
119 
120 /* Flag indicating that no shell has been requested */
121 extern int no_shell_flag;
122 
123 /* Control socket */
124 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
125 
126 /*
127  * Name of the host we are connecting to.  This is the name given on the
128  * command line, or the HostName specified for the user-supplied name in a
129  * configuration file.
130  */
131 extern char *host;
132 
133 /* Force TTY allocation */
134 extern int force_tty_flag;
135 
136 /*
137  * Flag to indicate that we have received a window change signal which has
138  * not yet been processed.  This will cause a message indicating the new
139  * window size to be sent to the server a little later.  This is volatile
140  * because this is updated in a signal handler.
141  */
142 static volatile sig_atomic_t received_window_change_signal = 0;
143 static volatile sig_atomic_t received_signal = 0;
144 
145 /* Flag indicating whether the user's terminal is in non-blocking mode. */
146 static int in_non_blocking_mode = 0;
147 
148 /* Time when backgrounded control master using ControlPersist should exit */
149 static time_t control_persist_exit_time = 0;
150 
151 /* Common data for the client loop code. */
152 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
153 static int escape_char1;	/* Escape character. (proto1 only) */
154 static int escape_pending1;	/* Last character was an escape (proto1 only) */
155 static int last_was_cr;		/* Last character was a newline. */
156 static int exit_status;		/* Used to store the command exit status. */
157 static int stdin_eof;		/* EOF has been encountered on stderr. */
158 static Buffer stdin_buffer;	/* Buffer for stdin data. */
159 static Buffer stdout_buffer;	/* Buffer for stdout data. */
160 static Buffer stderr_buffer;	/* Buffer for stderr data. */
161 static u_int buffer_high;	/* Soft max buffer size. */
162 static int connection_in;	/* Connection to server (input). */
163 static int connection_out;	/* Connection to server (output). */
164 static int need_rekeying;	/* Set to non-zero if rekeying is requested. */
165 static int session_closed;	/* In SSH2: login session closed. */
166 static int x11_refuse_time;	/* If >0, refuse x11 opens after this time. */
167 
168 static void client_init_dispatch(void);
169 int	session_ident = -1;
170 
171 int	session_resumed = 0;
172 
173 /* Track escape per proto2 channel */
174 struct escape_filter_ctx {
175 	int escape_pending;
176 	int escape_char;
177 };
178 
179 /* Context for channel confirmation replies */
180 struct channel_reply_ctx {
181 	const char *request_type;
182 	int id, do_close;
183 };
184 
185 /* Global request success/failure callbacks */
186 struct global_confirm {
187 	TAILQ_ENTRY(global_confirm) entry;
188 	global_confirm_cb *cb;
189 	void *ctx;
190 	int ref_count;
191 };
192 TAILQ_HEAD(global_confirms, global_confirm);
193 static struct global_confirms global_confirms =
194     TAILQ_HEAD_INITIALIZER(global_confirms);
195 
196 /*XXX*/
197 extern Kex *xxx_kex;
198 
199 void ssh_process_session2_setup(int, int, int, Buffer *);
200 
201 /* Restores stdin to blocking mode. */
202 
203 static void
204 leave_non_blocking(void)
205 {
206 	if (in_non_blocking_mode) {
207 		unset_nonblock(fileno(stdin));
208 		in_non_blocking_mode = 0;
209 	}
210 }
211 
212 /* Puts stdin terminal in non-blocking mode. */
213 
214 static void
215 enter_non_blocking(void)
216 {
217 	in_non_blocking_mode = 1;
218 	set_nonblock(fileno(stdin));
219 }
220 
221 /*
222  * Signal handler for the window change signal (SIGWINCH).  This just sets a
223  * flag indicating that the window has changed.
224  */
225 /*ARGSUSED */
226 static void
227 window_change_handler(int sig)
228 {
229 	received_window_change_signal = 1;
230 	signal(SIGWINCH, window_change_handler);
231 }
232 
233 /*
234  * Signal handler for signals that cause the program to terminate.  These
235  * signals must be trapped to restore terminal modes.
236  */
237 /*ARGSUSED */
238 static void
239 signal_handler(int sig)
240 {
241 	received_signal = sig;
242 	quit_pending = 1;
243 }
244 
245 /*
246  * Returns current time in seconds from Jan 1, 1970 with the maximum
247  * available resolution.
248  */
249 
250 static double
251 get_current_time(void)
252 {
253 	struct timeval tv;
254 	gettimeofday(&tv, NULL);
255 	return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
256 }
257 
258 /*
259  * Sets control_persist_exit_time to the absolute time when the
260  * backgrounded control master should exit due to expiry of the
261  * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
262  * control master process, or if there is no ControlPersist timeout.
263  */
264 static void
265 set_control_persist_exit_time(void)
266 {
267 	if (muxserver_sock == -1 || !options.control_persist
268 	    || options.control_persist_timeout == 0)
269 		/* not using a ControlPersist timeout */
270 		control_persist_exit_time = 0;
271 	else if (channel_still_open()) {
272 		/* some client connections are still open */
273 		if (control_persist_exit_time > 0)
274 			debug2("%s: cancel scheduled exit", __func__);
275 		control_persist_exit_time = 0;
276 	} else if (control_persist_exit_time <= 0) {
277 		/* a client connection has recently closed */
278 		control_persist_exit_time = time(NULL) +
279 			(time_t)options.control_persist_timeout;
280 		debug2("%s: schedule exit in %d seconds", __func__,
281 		    options.control_persist_timeout);
282 	}
283 	/* else we are already counting down to the timeout */
284 }
285 
286 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
287 void
288 client_x11_get_proto(const char *display, const char *xauth_path,
289     u_int trusted, u_int timeout, char **_proto, char **_data)
290 {
291 	char cmd[1024];
292 	char line[512];
293 	char xdisplay[512];
294 	static char proto[512], data[512];
295 	FILE *f;
296 	int got_data = 0, generated = 0, do_unlink = 0, i;
297 	char *xauthdir, *xauthfile;
298 	struct stat st;
299 	u_int now;
300 
301 	xauthdir = xauthfile = NULL;
302 	*_proto = proto;
303 	*_data = data;
304 	proto[0] = data[0] = '\0';
305 
306 	if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
307 		debug("No xauth program.");
308 	} else {
309 		if (display == NULL) {
310 			debug("x11_get_proto: DISPLAY not set");
311 			return;
312 		}
313 		/*
314 		 * Handle FamilyLocal case where $DISPLAY does
315 		 * not match an authorization entry.  For this we
316 		 * just try "xauth list unix:displaynum.screennum".
317 		 * XXX: "localhost" match to determine FamilyLocal
318 		 *      is not perfect.
319 		 */
320 		if (strncmp(display, "localhost:", 10) == 0) {
321 			snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
322 			    display + 10);
323 			display = xdisplay;
324 		}
325 		if (trusted == 0) {
326 			xauthdir = xmalloc(MAXPATHLEN);
327 			xauthfile = xmalloc(MAXPATHLEN);
328 			strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
329 			if (mkdtemp(xauthdir) != NULL) {
330 				do_unlink = 1;
331 				snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
332 				    xauthdir);
333 				snprintf(cmd, sizeof(cmd),
334 				    "%s -f %s generate %s " SSH_X11_PROTO
335 				    " untrusted timeout %u 2>" _PATH_DEVNULL,
336 				    xauth_path, xauthfile, display, timeout);
337 				debug2("x11_get_proto: %s", cmd);
338 				if (system(cmd) == 0)
339 					generated = 1;
340 				if (x11_refuse_time == 0) {
341 					now = time(NULL) + 1;
342 					if (UINT_MAX - timeout < now)
343 						x11_refuse_time = UINT_MAX;
344 					else
345 						x11_refuse_time = now + timeout;
346 				}
347 			}
348 		}
349 
350 		/*
351 		 * When in untrusted mode, we read the cookie only if it was
352 		 * successfully generated as an untrusted one in the step
353 		 * above.
354 		 */
355 		if (trusted || generated) {
356 			snprintf(cmd, sizeof(cmd),
357 			    "%s %s%s list %s 2>" _PATH_DEVNULL,
358 			    xauth_path,
359 			    generated ? "-f " : "" ,
360 			    generated ? xauthfile : "",
361 			    display);
362 			debug2("x11_get_proto: %s", cmd);
363 			f = popen(cmd, "r");
364 			if (f && fgets(line, sizeof(line), f) &&
365 			    sscanf(line, "%*s %511s %511s", proto, data) == 2)
366 				got_data = 1;
367 			if (f)
368 				pclose(f);
369 		} else
370 			error("Warning: untrusted X11 forwarding setup failed: "
371 			    "xauth key data not generated");
372 	}
373 
374 	if (do_unlink) {
375 		unlink(xauthfile);
376 		rmdir(xauthdir);
377 	}
378 	if (xauthdir)
379 		xfree(xauthdir);
380 	if (xauthfile)
381 		xfree(xauthfile);
382 
383 	/*
384 	 * If we didn't get authentication data, just make up some
385 	 * data.  The forwarding code will check the validity of the
386 	 * response anyway, and substitute this data.  The X11
387 	 * server, however, will ignore this fake data and use
388 	 * whatever authentication mechanisms it was using otherwise
389 	 * for the local connection.
390 	 */
391 	if (!got_data) {
392 		u_int32_t rnd = 0;
393 
394 		logit("Warning: No xauth data; "
395 		    "using fake authentication data for X11 forwarding.");
396 		strlcpy(proto, SSH_X11_PROTO, sizeof proto);
397 		for (i = 0; i < 16; i++) {
398 			if (i % 4 == 0)
399 				rnd = arc4random();
400 			snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
401 			    rnd & 0xff);
402 			rnd >>= 8;
403 		}
404 	}
405 }
406 
407 /*
408  * This is called when the interactive is entered.  This checks if there is
409  * an EOF coming on stdin.  We must check this explicitly, as select() does
410  * not appear to wake up when redirecting from /dev/null.
411  */
412 
413 static void
414 client_check_initial_eof_on_stdin(void)
415 {
416 	int len;
417 	char buf[1];
418 
419 	/*
420 	 * If standard input is to be "redirected from /dev/null", we simply
421 	 * mark that we have seen an EOF and send an EOF message to the
422 	 * server. Otherwise, we try to read a single character; it appears
423 	 * that for some files, such /dev/null, select() never wakes up for
424 	 * read for this descriptor, which means that we never get EOF.  This
425 	 * way we will get the EOF if stdin comes from /dev/null or similar.
426 	 */
427 	if (stdin_null_flag) {
428 		/* Fake EOF on stdin. */
429 		debug("Sending eof.");
430 		stdin_eof = 1;
431 		packet_start(SSH_CMSG_EOF);
432 		packet_send();
433 	} else {
434 		enter_non_blocking();
435 
436 		/* Check for immediate EOF on stdin. */
437 		len = read(fileno(stdin), buf, 1);
438 		if (len == 0) {
439 			/*
440 			 * EOF.  Record that we have seen it and send
441 			 * EOF to server.
442 			 */
443 			debug("Sending eof.");
444 			stdin_eof = 1;
445 			packet_start(SSH_CMSG_EOF);
446 			packet_send();
447 		} else if (len > 0) {
448 			/*
449 			 * Got data.  We must store the data in the buffer,
450 			 * and also process it as an escape character if
451 			 * appropriate.
452 			 */
453 			if ((u_char) buf[0] == escape_char1)
454 				escape_pending1 = 1;
455 			else
456 				buffer_append(&stdin_buffer, buf, 1);
457 		}
458 		leave_non_blocking();
459 	}
460 }
461 
462 
463 /*
464  * Make packets from buffered stdin data, and buffer them for sending to the
465  * connection.
466  */
467 
468 static void
469 client_make_packets_from_stdin_data(void)
470 {
471 	u_int len;
472 
473 	/* Send buffered stdin data to the server. */
474 	while (buffer_len(&stdin_buffer) > 0 &&
475 	    packet_not_very_much_data_to_write()) {
476 		len = buffer_len(&stdin_buffer);
477 		/* Keep the packets at reasonable size. */
478 		if (len > packet_get_maxsize())
479 			len = packet_get_maxsize();
480 		packet_start(SSH_CMSG_STDIN_DATA);
481 		packet_put_string(buffer_ptr(&stdin_buffer), len);
482 		packet_send();
483 		buffer_consume(&stdin_buffer, len);
484 		/* If we have a pending EOF, send it now. */
485 		if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
486 			packet_start(SSH_CMSG_EOF);
487 			packet_send();
488 		}
489 	}
490 }
491 
492 /*
493  * Checks if the client window has changed, and sends a packet about it to
494  * the server if so.  The actual change is detected elsewhere (by a software
495  * interrupt on Unix); this just checks the flag and sends a message if
496  * appropriate.
497  */
498 
499 static void
500 client_check_window_change(void)
501 {
502 	struct winsize ws;
503 
504 	if (! received_window_change_signal)
505 		return;
506 	/** XXX race */
507 	received_window_change_signal = 0;
508 
509 	debug2("client_check_window_change: changed");
510 
511 	if (compat20) {
512 		channel_send_window_changes();
513 	} else {
514 		if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
515 			return;
516 		packet_start(SSH_CMSG_WINDOW_SIZE);
517 		packet_put_int((u_int)ws.ws_row);
518 		packet_put_int((u_int)ws.ws_col);
519 		packet_put_int((u_int)ws.ws_xpixel);
520 		packet_put_int((u_int)ws.ws_ypixel);
521 		packet_send();
522 	}
523 }
524 
525 static void
526 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
527 {
528 	struct global_confirm *gc;
529 
530 	if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
531 		return;
532 	if (gc->cb != NULL)
533 		gc->cb(type, seq, gc->ctx);
534 	if (--gc->ref_count <= 0) {
535 		TAILQ_REMOVE(&global_confirms, gc, entry);
536 		bzero(gc, sizeof(*gc));
537 		xfree(gc);
538 	}
539 
540 	packet_set_alive_timeouts(0);
541 }
542 
543 static void
544 server_alive_check(void)
545 {
546 	if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
547 		logit("Timeout, server not responding.");
548 		cleanup_exit(255);
549 	}
550 	packet_start(SSH2_MSG_GLOBAL_REQUEST);
551 	packet_put_cstring("keepalive@openssh.com");
552 	packet_put_char(1);     /* boolean: want reply */
553 	packet_send();
554 	/* Insert an empty placeholder to maintain ordering */
555 	client_register_global_confirm(NULL, NULL);
556 }
557 
558 /*
559  * Waits until the client can do something (some data becomes available on
560  * one of the file descriptors).
561  */
562 static void
563 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
564     int *maxfdp, u_int *nallocp, int rekeying)
565 {
566 	struct timeval tv, *tvp;
567 	int timeout_secs;
568 	int ret;
569 
570 	/* Add any selections by the channel mechanism. */
571 	channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
572 
573 	if (!compat20) {
574 		/* Read from the connection, unless our buffers are full. */
575 		if (buffer_len(&stdout_buffer) < buffer_high &&
576 		    buffer_len(&stderr_buffer) < buffer_high &&
577 		    channel_not_very_much_buffered_data())
578 			FD_SET(connection_in, *readsetp);
579 		/*
580 		 * Read from stdin, unless we have seen EOF or have very much
581 		 * buffered data to send to the server.
582 		 */
583 		if (!stdin_eof && packet_not_very_much_data_to_write())
584 			FD_SET(fileno(stdin), *readsetp);
585 
586 		/* Select stdout/stderr if have data in buffer. */
587 		if (buffer_len(&stdout_buffer) > 0)
588 			FD_SET(fileno(stdout), *writesetp);
589 		if (buffer_len(&stderr_buffer) > 0)
590 			FD_SET(fileno(stderr), *writesetp);
591 	} else {
592 		/* channel_prepare_select could have closed the last channel */
593 		if (session_closed && !channel_still_open() &&
594 		    !packet_have_data_to_write()) {
595 			/* clear mask since we did not call select() */
596 			memset(*readsetp, 0, *nallocp);
597 			memset(*writesetp, 0, *nallocp);
598 			return;
599 		} else {
600 			FD_SET(connection_in, *readsetp);
601 		}
602 	}
603 
604 	/* Select server connection if have data to write to the server. */
605 	if (packet_have_data_to_write())
606 		FD_SET(connection_out, *writesetp);
607 
608 	/*
609 	 * Wait for something to happen.  This will suspend the process until
610 	 * some selected descriptor can be read, written, or has some other
611 	 * event pending, or a timeout expires.
612 	 */
613 
614 	timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
615 	if (options.server_alive_interval > 0 && compat20)
616 		timeout_secs = options.server_alive_interval;
617 	set_control_persist_exit_time();
618 	if (control_persist_exit_time > 0) {
619 		timeout_secs = MIN(timeout_secs,
620 			control_persist_exit_time - time(NULL));
621 		if (timeout_secs < 0)
622 			timeout_secs = 0;
623 	}
624 	if (timeout_secs == INT_MAX)
625 		tvp = NULL;
626 	else {
627 		tv.tv_sec = timeout_secs;
628 		tv.tv_usec = 0;
629 		tvp = &tv;
630 	}
631 
632 	ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
633 	if (ret < 0) {
634 		char buf[100];
635 
636 		/*
637 		 * We have to clear the select masks, because we return.
638 		 * We have to return, because the mainloop checks for the flags
639 		 * set by the signal handlers.
640 		 */
641 		memset(*readsetp, 0, *nallocp);
642 		memset(*writesetp, 0, *nallocp);
643 
644 		if (errno == EINTR)
645 			return;
646 		/* Note: we might still have data in the buffers. */
647 		snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
648 		buffer_append(&stderr_buffer, buf, strlen(buf));
649 		quit_pending = 1;
650 	} else if (ret == 0)
651 		server_alive_check();
652 }
653 
654 static void
655 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
656 {
657 	/* Flush stdout and stderr buffers. */
658 	if (buffer_len(bout) > 0)
659 		atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
660 		    buffer_len(bout));
661 	if (buffer_len(berr) > 0)
662 		atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
663 		    buffer_len(berr));
664 
665 	leave_raw_mode(force_tty_flag);
666 
667 	/*
668 	 * Free (and clear) the buffer to reduce the amount of data that gets
669 	 * written to swap.
670 	 */
671 	buffer_free(bin);
672 	buffer_free(bout);
673 	buffer_free(berr);
674 
675 	/* Send the suspend signal to the program itself. */
676 	kill(getpid(), SIGTSTP);
677 
678 	/* Reset window sizes in case they have changed */
679 	received_window_change_signal = 1;
680 
681 	/* OK, we have been continued by the user. Reinitialize buffers. */
682 	buffer_init(bin);
683 	buffer_init(bout);
684 	buffer_init(berr);
685 
686 	enter_raw_mode(force_tty_flag);
687 }
688 
689 static void
690 client_process_net_input(fd_set *readset)
691 {
692 	int len, cont = 0;
693 	char buf[SSH_IOBUFSZ];
694 
695 	/*
696 	 * Read input from the server, and add any such data to the buffer of
697 	 * the packet subsystem.
698 	 */
699 	if (FD_ISSET(connection_in, readset)) {
700 		/* Read as much as possible. */
701 		len = roaming_read(connection_in, buf, sizeof(buf), &cont);
702 		if (len == 0 && cont == 0) {
703 			/*
704 			 * Received EOF.  The remote host has closed the
705 			 * connection.
706 			 */
707 			snprintf(buf, sizeof buf,
708 			    "Connection to %.300s closed by remote host.\r\n",
709 			    host);
710 			buffer_append(&stderr_buffer, buf, strlen(buf));
711 			quit_pending = 1;
712 			return;
713 		}
714 		/*
715 		 * There is a kernel bug on Solaris that causes select to
716 		 * sometimes wake up even though there is no data available.
717 		 */
718 		if (len < 0 &&
719 		    (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
720 			len = 0;
721 
722 		if (len < 0) {
723 			/*
724 			 * An error has encountered.  Perhaps there is a
725 			 * network problem.
726 			 */
727 			snprintf(buf, sizeof buf,
728 			    "Read from remote host %.300s: %.100s\r\n",
729 			    host, strerror(errno));
730 			buffer_append(&stderr_buffer, buf, strlen(buf));
731 			quit_pending = 1;
732 			return;
733 		}
734 		packet_process_incoming(buf, len);
735 	}
736 }
737 
738 static void
739 client_status_confirm(int type, Channel *c, void *ctx)
740 {
741 	struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
742 	char errmsg[256];
743 	int tochan;
744 
745 	/* XXX supress on mux _client_ quietmode */
746 	tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
747 	    c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
748 
749 	if (type == SSH2_MSG_CHANNEL_SUCCESS) {
750 		debug2("%s request accepted on channel %d",
751 		    cr->request_type, c->self);
752 	} else if (type == SSH2_MSG_CHANNEL_FAILURE) {
753 		if (tochan) {
754 			snprintf(errmsg, sizeof(errmsg),
755 			    "%s request failed\r\n", cr->request_type);
756 		} else {
757 			snprintf(errmsg, sizeof(errmsg),
758 			    "%s request failed on channel %d",
759 			    cr->request_type, c->self);
760 		}
761 		/* If error occurred on primary session channel, then exit */
762 		if (cr->do_close && c->self == session_ident)
763 			fatal("%s", errmsg);
764 		/* If error occurred on mux client, append to their stderr */
765 		if (tochan)
766 			buffer_append(&c->extended, errmsg, strlen(errmsg));
767 		else
768 			error("%s", errmsg);
769 		if (cr->do_close) {
770 			chan_read_failed(c);
771 			chan_write_failed(c);
772 		}
773 	}
774 	xfree(cr);
775 }
776 
777 static void
778 client_abandon_status_confirm(Channel *c, void *ctx)
779 {
780 	xfree(ctx);
781 }
782 
783 static void
784 client_expect_confirm(int id, const char *request, int do_close)
785 {
786 	struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
787 
788 	cr->request_type = request;
789 	cr->do_close = do_close;
790 
791 	channel_register_status_confirm(id, client_status_confirm,
792 	    client_abandon_status_confirm, cr);
793 }
794 
795 void
796 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
797 {
798 	struct global_confirm *gc, *last_gc;
799 
800 	/* Coalesce identical callbacks */
801 	last_gc = TAILQ_LAST(&global_confirms, global_confirms);
802 	if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
803 		if (++last_gc->ref_count >= INT_MAX)
804 			fatal("%s: last_gc->ref_count = %d",
805 			    __func__, last_gc->ref_count);
806 		return;
807 	}
808 
809 	gc = xmalloc(sizeof(*gc));
810 	gc->cb = cb;
811 	gc->ctx = ctx;
812 	gc->ref_count = 1;
813 	TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
814 }
815 
816 static void
817 process_cmdline(void)
818 {
819 	void (*handler)(int);
820 	char *s, *cmd, *cancel_host;
821 	int delete = 0;
822 	int local = 0, remote = 0, dynamic = 0;
823 	int cancel_port;
824 	Forward fwd;
825 
826 	bzero(&fwd, sizeof(fwd));
827 	fwd.listen_host = fwd.connect_host = NULL;
828 
829 	leave_raw_mode(force_tty_flag);
830 	handler = signal(SIGINT, SIG_IGN);
831 	cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
832 	if (s == NULL)
833 		goto out;
834 	while (isspace(*s))
835 		s++;
836 	if (*s == '-')
837 		s++;	/* Skip cmdline '-', if any */
838 	if (*s == '\0')
839 		goto out;
840 
841 	if (*s == 'h' || *s == 'H' || *s == '?') {
842 		logit("Commands:");
843 		logit("      -L[bind_address:]port:host:hostport    "
844 		    "Request local forward");
845 		logit("      -R[bind_address:]port:host:hostport    "
846 		    "Request remote forward");
847 		logit("      -D[bind_address:]port                  "
848 		    "Request dynamic forward");
849 		logit("      -KR[bind_address:]port                 "
850 		    "Cancel remote forward");
851 		if (!options.permit_local_command)
852 			goto out;
853 		logit("      !args                                  "
854 		    "Execute local command");
855 		goto out;
856 	}
857 
858 	if (*s == '!' && options.permit_local_command) {
859 		s++;
860 		ssh_local_cmd(s);
861 		goto out;
862 	}
863 
864 	if (*s == 'K') {
865 		delete = 1;
866 		s++;
867 	}
868 	if (*s == 'L')
869 		local = 1;
870 	else if (*s == 'R')
871 		remote = 1;
872 	else if (*s == 'D')
873 		dynamic = 1;
874 	else {
875 		logit("Invalid command.");
876 		goto out;
877 	}
878 
879 	if ((local || dynamic) && delete) {
880 		logit("Not supported.");
881 		goto out;
882 	}
883 	if (remote && delete && !compat20) {
884 		logit("Not supported for SSH protocol version 1.");
885 		goto out;
886 	}
887 
888 	while (isspace(*++s))
889 		;
890 
891 	/* XXX update list of forwards in options */
892 	if (delete) {
893 		cancel_port = 0;
894 		cancel_host = hpdelim(&s);	/* may be NULL */
895 		if (s != NULL) {
896 			cancel_port = a2port(s);
897 			cancel_host = cleanhostname(cancel_host);
898 		} else {
899 			cancel_port = a2port(cancel_host);
900 			cancel_host = NULL;
901 		}
902 		if (cancel_port <= 0) {
903 			logit("Bad forwarding close port");
904 			goto out;
905 		}
906 		channel_request_rforward_cancel(cancel_host, cancel_port);
907 	} else {
908 		if (!parse_forward(&fwd, s, dynamic, remote)) {
909 			logit("Bad forwarding specification.");
910 			goto out;
911 		}
912 		if (local || dynamic) {
913 			if (channel_setup_local_fwd_listener(fwd.listen_host,
914 			    fwd.listen_port, fwd.connect_host,
915 			    fwd.connect_port, options.gateway_ports) < 0) {
916 				logit("Port forwarding failed.");
917 				goto out;
918 			}
919 		} else {
920 			if (channel_request_remote_forwarding(fwd.listen_host,
921 			    fwd.listen_port, fwd.connect_host,
922 			    fwd.connect_port) < 0) {
923 				logit("Port forwarding failed.");
924 				goto out;
925 			}
926 		}
927 
928 		logit("Forwarding port.");
929 	}
930 
931 out:
932 	signal(SIGINT, handler);
933 	enter_raw_mode(force_tty_flag);
934 	if (cmd)
935 		xfree(cmd);
936 	if (fwd.listen_host != NULL)
937 		xfree(fwd.listen_host);
938 	if (fwd.connect_host != NULL)
939 		xfree(fwd.connect_host);
940 }
941 
942 /*
943  * Process the characters one by one, call with c==NULL for proto1 case.
944  */
945 static int
946 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
947     char *buf, int len)
948 {
949 	char string[1024];
950 	pid_t pid;
951 	int bytes = 0;
952 	u_int i;
953 	u_char ch;
954 	char *s;
955 	int *escape_pendingp, escape_char;
956 	struct escape_filter_ctx *efc;
957 
958 	if (c == NULL) {
959 		escape_pendingp = &escape_pending1;
960 		escape_char = escape_char1;
961 	} else {
962 		if (c->filter_ctx == NULL)
963 			return 0;
964 		efc = (struct escape_filter_ctx *)c->filter_ctx;
965 		escape_pendingp = &efc->escape_pending;
966 		escape_char = efc->escape_char;
967 	}
968 
969 	if (len <= 0)
970 		return (0);
971 
972 	for (i = 0; i < (u_int)len; i++) {
973 		/* Get one character at a time. */
974 		ch = buf[i];
975 
976 		if (*escape_pendingp) {
977 			/* We have previously seen an escape character. */
978 			/* Clear the flag now. */
979 			*escape_pendingp = 0;
980 
981 			/* Process the escaped character. */
982 			switch (ch) {
983 			case '.':
984 				/* Terminate the connection. */
985 				snprintf(string, sizeof string, "%c.\r\n",
986 				    escape_char);
987 				buffer_append(berr, string, strlen(string));
988 
989 				if (c && c->ctl_chan != -1) {
990 					chan_read_failed(c);
991 					chan_write_failed(c);
992 					return 0;
993 				} else
994 					quit_pending = 1;
995 				return -1;
996 
997 			case 'Z' - 64:
998 				/* XXX support this for mux clients */
999 				if (c && c->ctl_chan != -1) {
1000  noescape:
1001 					snprintf(string, sizeof string,
1002 					    "%c%c escape not available to "
1003 					    "multiplexed sessions\r\n",
1004 					    escape_char, ch);
1005 					buffer_append(berr, string,
1006 					    strlen(string));
1007 					continue;
1008 				}
1009 				/* Suspend the program. Inform the user */
1010 				snprintf(string, sizeof string,
1011 				    "%c^Z [suspend ssh]\r\n", escape_char);
1012 				buffer_append(berr, string, strlen(string));
1013 
1014 				/* Restore terminal modes and suspend. */
1015 				client_suspend_self(bin, bout, berr);
1016 
1017 				/* We have been continued. */
1018 				continue;
1019 
1020 			case 'B':
1021 				if (compat20) {
1022 					snprintf(string, sizeof string,
1023 					    "%cB\r\n", escape_char);
1024 					buffer_append(berr, string,
1025 					    strlen(string));
1026 					channel_request_start(session_ident,
1027 					    "break", 0);
1028 					packet_put_int(1000);
1029 					packet_send();
1030 				}
1031 				continue;
1032 
1033 			case 'R':
1034 				if (compat20) {
1035 					if (datafellows & SSH_BUG_NOREKEY)
1036 						logit("Server does not "
1037 						    "support re-keying");
1038 					else
1039 						need_rekeying = 1;
1040 				}
1041 				continue;
1042 
1043 			case '&':
1044 				if (c && c->ctl_chan != -1)
1045 					goto noescape;
1046 				/*
1047 				 * Detach the program (continue to serve
1048 				 * connections, but put in background and no
1049 				 * more new connections).
1050 				 */
1051 				/* Restore tty modes. */
1052 				leave_raw_mode(force_tty_flag);
1053 
1054 				/* Stop listening for new connections. */
1055 				channel_stop_listening();
1056 
1057 				snprintf(string, sizeof string,
1058 				    "%c& [backgrounded]\n", escape_char);
1059 				buffer_append(berr, string, strlen(string));
1060 
1061 				/* Fork into background. */
1062 				pid = fork();
1063 				if (pid < 0) {
1064 					error("fork: %.100s", strerror(errno));
1065 					continue;
1066 				}
1067 				if (pid != 0) {	/* This is the parent. */
1068 					/* The parent just exits. */
1069 					exit(0);
1070 				}
1071 				/* The child continues serving connections. */
1072 				if (compat20) {
1073 					buffer_append(bin, "\004", 1);
1074 					/* fake EOF on stdin */
1075 					return -1;
1076 				} else if (!stdin_eof) {
1077 					/*
1078 					 * Sending SSH_CMSG_EOF alone does not
1079 					 * always appear to be enough.  So we
1080 					 * try to send an EOF character first.
1081 					 */
1082 					packet_start(SSH_CMSG_STDIN_DATA);
1083 					packet_put_string("\004", 1);
1084 					packet_send();
1085 					/* Close stdin. */
1086 					stdin_eof = 1;
1087 					if (buffer_len(bin) == 0) {
1088 						packet_start(SSH_CMSG_EOF);
1089 						packet_send();
1090 					}
1091 				}
1092 				continue;
1093 
1094 			case '?':
1095 				if (c && c->ctl_chan != -1) {
1096 					snprintf(string, sizeof string,
1097 "%c?\r\n\
1098 Supported escape sequences:\r\n\
1099   %c.  - terminate session\r\n\
1100   %cB  - send a BREAK to the remote system\r\n\
1101   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1102   %c#  - list forwarded connections\r\n\
1103   %c?  - this message\r\n\
1104   %c%c  - send the escape character by typing it twice\r\n\
1105 (Note that escapes are only recognized immediately after newline.)\r\n",
1106 					    escape_char, escape_char,
1107 					    escape_char, escape_char,
1108 					    escape_char, escape_char,
1109 					    escape_char, escape_char);
1110 				} else {
1111 					snprintf(string, sizeof string,
1112 "%c?\r\n\
1113 Supported escape sequences:\r\n\
1114   %c.  - terminate connection (and any multiplexed sessions)\r\n\
1115   %cB  - send a BREAK to the remote system\r\n\
1116   %cC  - open a command line\r\n\
1117   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1118   %c^Z - suspend ssh\r\n\
1119   %c#  - list forwarded connections\r\n\
1120   %c&  - background ssh (when waiting for connections to terminate)\r\n\
1121   %c?  - this message\r\n\
1122   %c%c  - send the escape character by typing it twice\r\n\
1123 (Note that escapes are only recognized immediately after newline.)\r\n",
1124 					    escape_char, escape_char,
1125 					    escape_char, escape_char,
1126 					    escape_char, escape_char,
1127 					    escape_char, escape_char,
1128 					    escape_char, escape_char,
1129 					    escape_char);
1130 				}
1131 				buffer_append(berr, string, strlen(string));
1132 				continue;
1133 
1134 			case '#':
1135 				snprintf(string, sizeof string, "%c#\r\n",
1136 				    escape_char);
1137 				buffer_append(berr, string, strlen(string));
1138 				s = channel_open_message();
1139 				buffer_append(berr, s, strlen(s));
1140 				xfree(s);
1141 				continue;
1142 
1143 			case 'C':
1144 				if (c && c->ctl_chan != -1)
1145 					goto noescape;
1146 				process_cmdline();
1147 				continue;
1148 
1149 			default:
1150 				if (ch != escape_char) {
1151 					buffer_put_char(bin, escape_char);
1152 					bytes++;
1153 				}
1154 				/* Escaped characters fall through here */
1155 				break;
1156 			}
1157 		} else {
1158 			/*
1159 			 * The previous character was not an escape char.
1160 			 * Check if this is an escape.
1161 			 */
1162 			if (last_was_cr && ch == escape_char) {
1163 				/*
1164 				 * It is. Set the flag and continue to
1165 				 * next character.
1166 				 */
1167 				*escape_pendingp = 1;
1168 				continue;
1169 			}
1170 		}
1171 
1172 		/*
1173 		 * Normal character.  Record whether it was a newline,
1174 		 * and append it to the buffer.
1175 		 */
1176 		last_was_cr = (ch == '\r' || ch == '\n');
1177 		buffer_put_char(bin, ch);
1178 		bytes++;
1179 	}
1180 	return bytes;
1181 }
1182 
1183 static void
1184 client_process_input(fd_set *readset)
1185 {
1186 	int len;
1187 	char buf[SSH_IOBUFSZ];
1188 
1189 	/* Read input from stdin. */
1190 	if (FD_ISSET(fileno(stdin), readset)) {
1191 		/* Read as much as possible. */
1192 		len = read(fileno(stdin), buf, sizeof(buf));
1193 		if (len < 0 &&
1194 		    (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1195 			return;		/* we'll try again later */
1196 		if (len <= 0) {
1197 			/*
1198 			 * Received EOF or error.  They are treated
1199 			 * similarly, except that an error message is printed
1200 			 * if it was an error condition.
1201 			 */
1202 			if (len < 0) {
1203 				snprintf(buf, sizeof buf, "read: %.100s\r\n",
1204 				    strerror(errno));
1205 				buffer_append(&stderr_buffer, buf, strlen(buf));
1206 			}
1207 			/* Mark that we have seen EOF. */
1208 			stdin_eof = 1;
1209 			/*
1210 			 * Send an EOF message to the server unless there is
1211 			 * data in the buffer.  If there is data in the
1212 			 * buffer, no message will be sent now.  Code
1213 			 * elsewhere will send the EOF when the buffer
1214 			 * becomes empty if stdin_eof is set.
1215 			 */
1216 			if (buffer_len(&stdin_buffer) == 0) {
1217 				packet_start(SSH_CMSG_EOF);
1218 				packet_send();
1219 			}
1220 		} else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1221 			/*
1222 			 * Normal successful read, and no escape character.
1223 			 * Just append the data to buffer.
1224 			 */
1225 			buffer_append(&stdin_buffer, buf, len);
1226 		} else {
1227 			/*
1228 			 * Normal, successful read.  But we have an escape
1229 			 * character and have to process the characters one
1230 			 * by one.
1231 			 */
1232 			if (process_escapes(NULL, &stdin_buffer,
1233 			    &stdout_buffer, &stderr_buffer, buf, len) == -1)
1234 				return;
1235 		}
1236 	}
1237 }
1238 
1239 static void
1240 client_process_output(fd_set *writeset)
1241 {
1242 	int len;
1243 	char buf[100];
1244 
1245 	/* Write buffered output to stdout. */
1246 	if (FD_ISSET(fileno(stdout), writeset)) {
1247 		/* Write as much data as possible. */
1248 		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1249 		    buffer_len(&stdout_buffer));
1250 		if (len <= 0) {
1251 			if (errno == EINTR || errno == EAGAIN ||
1252 			    errno == EWOULDBLOCK)
1253 				len = 0;
1254 			else {
1255 				/*
1256 				 * An error or EOF was encountered.  Put an
1257 				 * error message to stderr buffer.
1258 				 */
1259 				snprintf(buf, sizeof buf,
1260 				    "write stdout: %.50s\r\n", strerror(errno));
1261 				buffer_append(&stderr_buffer, buf, strlen(buf));
1262 				quit_pending = 1;
1263 				return;
1264 			}
1265 		}
1266 		/* Consume printed data from the buffer. */
1267 		buffer_consume(&stdout_buffer, len);
1268 	}
1269 	/* Write buffered output to stderr. */
1270 	if (FD_ISSET(fileno(stderr), writeset)) {
1271 		/* Write as much data as possible. */
1272 		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1273 		    buffer_len(&stderr_buffer));
1274 		if (len <= 0) {
1275 			if (errno == EINTR || errno == EAGAIN ||
1276 			    errno == EWOULDBLOCK)
1277 				len = 0;
1278 			else {
1279 				/*
1280 				 * EOF or error, but can't even print
1281 				 * error message.
1282 				 */
1283 				quit_pending = 1;
1284 				return;
1285 			}
1286 		}
1287 		/* Consume printed characters from the buffer. */
1288 		buffer_consume(&stderr_buffer, len);
1289 	}
1290 }
1291 
1292 /*
1293  * Get packets from the connection input buffer, and process them as long as
1294  * there are packets available.
1295  *
1296  * Any unknown packets received during the actual
1297  * session cause the session to terminate.  This is
1298  * intended to make debugging easier since no
1299  * confirmations are sent.  Any compatible protocol
1300  * extensions must be negotiated during the
1301  * preparatory phase.
1302  */
1303 
1304 static void
1305 client_process_buffered_input_packets(void)
1306 {
1307 	dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1308 	    compat20 ? xxx_kex : NULL);
1309 }
1310 
1311 /* scan buf[] for '~' before sending data to the peer */
1312 
1313 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1314 void *
1315 client_new_escape_filter_ctx(int escape_char)
1316 {
1317 	struct escape_filter_ctx *ret;
1318 
1319 	ret = xmalloc(sizeof(*ret));
1320 	ret->escape_pending = 0;
1321 	ret->escape_char = escape_char;
1322 	return (void *)ret;
1323 }
1324 
1325 /* Free the escape filter context on channel free */
1326 void
1327 client_filter_cleanup(int cid, void *ctx)
1328 {
1329 	xfree(ctx);
1330 }
1331 
1332 int
1333 client_simple_escape_filter(Channel *c, char *buf, int len)
1334 {
1335 	if (c->extended_usage != CHAN_EXTENDED_WRITE)
1336 		return 0;
1337 
1338 	return process_escapes(c, &c->input, &c->output, &c->extended,
1339 	    buf, len);
1340 }
1341 
1342 static void
1343 client_channel_closed(int id, void *arg)
1344 {
1345 	channel_cancel_cleanup(id);
1346 	session_closed = 1;
1347 	leave_raw_mode(force_tty_flag);
1348 }
1349 
1350 /*
1351  * Implements the interactive session with the server.  This is called after
1352  * the user has been authenticated, and a command has been started on the
1353  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1354  * used as an escape character for terminating or suspending the session.
1355  */
1356 
1357 int
1358 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1359 {
1360 	fd_set *readset = NULL, *writeset = NULL;
1361 	double start_time, total_time;
1362 	int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1363 	u_int64_t ibytes, obytes;
1364 	u_int nalloc = 0;
1365 	char buf[100];
1366 
1367 	debug("Entering interactive session.");
1368 
1369 	start_time = get_current_time();
1370 
1371 	/* Initialize variables. */
1372 	escape_pending1 = 0;
1373 	last_was_cr = 1;
1374 	exit_status = -1;
1375 	stdin_eof = 0;
1376 	buffer_high = 64 * 1024;
1377 	connection_in = packet_get_connection_in();
1378 	connection_out = packet_get_connection_out();
1379 	max_fd = MAX(connection_in, connection_out);
1380 
1381 	if (!compat20) {
1382 		/* enable nonblocking unless tty */
1383 		if (!isatty(fileno(stdin)))
1384 			set_nonblock(fileno(stdin));
1385 		if (!isatty(fileno(stdout)))
1386 			set_nonblock(fileno(stdout));
1387 		if (!isatty(fileno(stderr)))
1388 			set_nonblock(fileno(stderr));
1389 		max_fd = MAX(max_fd, fileno(stdin));
1390 		max_fd = MAX(max_fd, fileno(stdout));
1391 		max_fd = MAX(max_fd, fileno(stderr));
1392 	}
1393 	quit_pending = 0;
1394 	escape_char1 = escape_char_arg;
1395 
1396 	/* Initialize buffers. */
1397 	buffer_init(&stdin_buffer);
1398 	buffer_init(&stdout_buffer);
1399 	buffer_init(&stderr_buffer);
1400 
1401 	client_init_dispatch();
1402 
1403 	/*
1404 	 * Set signal handlers, (e.g. to restore non-blocking mode)
1405 	 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1406 	 */
1407 	if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1408 		signal(SIGHUP, signal_handler);
1409 	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1410 		signal(SIGINT, signal_handler);
1411 	if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1412 		signal(SIGQUIT, signal_handler);
1413 	if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1414 		signal(SIGTERM, signal_handler);
1415 	signal(SIGWINCH, window_change_handler);
1416 
1417 	if (have_pty)
1418 		enter_raw_mode(force_tty_flag);
1419 
1420 	if (compat20) {
1421 		session_ident = ssh2_chan_id;
1422 		if (escape_char_arg != SSH_ESCAPECHAR_NONE)
1423 			channel_register_filter(session_ident,
1424 			    client_simple_escape_filter, NULL,
1425 			    client_filter_cleanup,
1426 			    client_new_escape_filter_ctx(escape_char_arg));
1427 		if (session_ident != -1)
1428 			channel_register_cleanup(session_ident,
1429 			    client_channel_closed, 0);
1430 	} else {
1431 		/* Check if we should immediately send eof on stdin. */
1432 		client_check_initial_eof_on_stdin();
1433 	}
1434 
1435 	/* Main loop of the client for the interactive session mode. */
1436 	while (!quit_pending) {
1437 
1438 		/* Process buffered packets sent by the server. */
1439 		client_process_buffered_input_packets();
1440 
1441 		if (compat20 && session_closed && !channel_still_open())
1442 			break;
1443 
1444 		rekeying = (xxx_kex != NULL && !xxx_kex->done);
1445 
1446 		if (rekeying) {
1447 			debug("rekeying in progress");
1448 		} else {
1449 			/*
1450 			 * Make packets of buffered stdin data, and buffer
1451 			 * them for sending to the server.
1452 			 */
1453 			if (!compat20)
1454 				client_make_packets_from_stdin_data();
1455 
1456 			/*
1457 			 * Make packets from buffered channel data, and
1458 			 * enqueue them for sending to the server.
1459 			 */
1460 			if (packet_not_very_much_data_to_write())
1461 				channel_output_poll();
1462 
1463 			/*
1464 			 * Check if the window size has changed, and buffer a
1465 			 * message about it to the server if so.
1466 			 */
1467 			client_check_window_change();
1468 
1469 			if (quit_pending)
1470 				break;
1471 		}
1472 		/*
1473 		 * Wait until we have something to do (something becomes
1474 		 * available on one of the descriptors).
1475 		 */
1476 		max_fd2 = max_fd;
1477 		client_wait_until_can_do_something(&readset, &writeset,
1478 		    &max_fd2, &nalloc, rekeying);
1479 
1480 		if (quit_pending)
1481 			break;
1482 
1483 		/* Do channel operations unless rekeying in progress. */
1484 		if (!rekeying) {
1485 			channel_after_select(readset, writeset);
1486 			if (need_rekeying || packet_need_rekeying()) {
1487 				debug("need rekeying");
1488 				xxx_kex->done = 0;
1489 				kex_send_kexinit(xxx_kex);
1490 				need_rekeying = 0;
1491 			}
1492 		}
1493 
1494 		/* Buffer input from the connection.  */
1495 		client_process_net_input(readset);
1496 
1497 		if (quit_pending)
1498 			break;
1499 
1500 		if (!compat20) {
1501 			/* Buffer data from stdin */
1502 			client_process_input(readset);
1503 			/*
1504 			 * Process output to stdout and stderr.  Output to
1505 			 * the connection is processed elsewhere (above).
1506 			 */
1507 			client_process_output(writeset);
1508 		}
1509 
1510 		if (session_resumed) {
1511 			connection_in = packet_get_connection_in();
1512 			connection_out = packet_get_connection_out();
1513 			max_fd = MAX(max_fd, connection_out);
1514 			max_fd = MAX(max_fd, connection_in);
1515 			session_resumed = 0;
1516 		}
1517 
1518 		/*
1519 		 * Send as much buffered packet data as possible to the
1520 		 * sender.
1521 		 */
1522 		if (FD_ISSET(connection_out, writeset))
1523 			packet_write_poll();
1524 
1525 		/*
1526 		 * If we are a backgrounded control master, and the
1527 		 * timeout has expired without any active client
1528 		 * connections, then quit.
1529 		 */
1530 		if (control_persist_exit_time > 0) {
1531 			if (time(NULL) >= control_persist_exit_time) {
1532 				debug("ControlPersist timeout expired");
1533 				break;
1534 			}
1535 		}
1536 	}
1537 	if (readset)
1538 		xfree(readset);
1539 	if (writeset)
1540 		xfree(writeset);
1541 
1542 	/* Terminate the session. */
1543 
1544 	/* Stop watching for window change. */
1545 	signal(SIGWINCH, SIG_DFL);
1546 
1547 	if (compat20) {
1548 		packet_start(SSH2_MSG_DISCONNECT);
1549 		packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1550 		packet_put_cstring("disconnected by user");
1551 		packet_put_cstring(""); /* language tag */
1552 		packet_send();
1553 		packet_write_wait();
1554 	}
1555 
1556 	channel_free_all();
1557 
1558 	if (have_pty)
1559 		leave_raw_mode(force_tty_flag);
1560 
1561 	/* restore blocking io */
1562 	if (!isatty(fileno(stdin)))
1563 		unset_nonblock(fileno(stdin));
1564 	if (!isatty(fileno(stdout)))
1565 		unset_nonblock(fileno(stdout));
1566 	if (!isatty(fileno(stderr)))
1567 		unset_nonblock(fileno(stderr));
1568 
1569 	/*
1570 	 * If there was no shell or command requested, there will be no remote
1571 	 * exit status to be returned.  In that case, clear error code if the
1572 	 * connection was deliberately terminated at this end.
1573 	 */
1574 	if (no_shell_flag && received_signal == SIGTERM) {
1575 		received_signal = 0;
1576 		exit_status = 0;
1577 	}
1578 
1579 	if (received_signal)
1580 		fatal("Killed by signal %d.", (int) received_signal);
1581 
1582 	/*
1583 	 * In interactive mode (with pseudo tty) display a message indicating
1584 	 * that the connection has been closed.
1585 	 */
1586 	if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1587 		snprintf(buf, sizeof buf,
1588 		    "Connection to %.64s closed.\r\n", host);
1589 		buffer_append(&stderr_buffer, buf, strlen(buf));
1590 	}
1591 
1592 	/* Output any buffered data for stdout. */
1593 	while (buffer_len(&stdout_buffer) > 0) {
1594 		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1595 		    buffer_len(&stdout_buffer));
1596 		if (len <= 0) {
1597 			error("Write failed flushing stdout buffer.");
1598 			break;
1599 		}
1600 		buffer_consume(&stdout_buffer, len);
1601 	}
1602 
1603 	/* Output any buffered data for stderr. */
1604 	while (buffer_len(&stderr_buffer) > 0) {
1605 		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1606 		    buffer_len(&stderr_buffer));
1607 		if (len <= 0) {
1608 			error("Write failed flushing stderr buffer.");
1609 			break;
1610 		}
1611 		buffer_consume(&stderr_buffer, len);
1612 	}
1613 
1614 	/* Clear and free any buffers. */
1615 	memset(buf, 0, sizeof(buf));
1616 	buffer_free(&stdin_buffer);
1617 	buffer_free(&stdout_buffer);
1618 	buffer_free(&stderr_buffer);
1619 
1620 	/* Report bytes transferred, and transfer rates. */
1621 	total_time = get_current_time() - start_time;
1622 	packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
1623 	packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1624 	verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1625 	    obytes, ibytes, total_time);
1626 	if (total_time > 0)
1627 		verbose("Bytes per second: sent %.1f, received %.1f",
1628 		    obytes / total_time, ibytes / total_time);
1629 	/* Return the exit status of the program. */
1630 	debug("Exit status %d", exit_status);
1631 	return exit_status;
1632 }
1633 
1634 /*********/
1635 
1636 static void
1637 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1638 {
1639 	u_int data_len;
1640 	char *data = packet_get_string(&data_len);
1641 	packet_check_eom();
1642 	buffer_append(&stdout_buffer, data, data_len);
1643 	memset(data, 0, data_len);
1644 	xfree(data);
1645 }
1646 static void
1647 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1648 {
1649 	u_int data_len;
1650 	char *data = packet_get_string(&data_len);
1651 	packet_check_eom();
1652 	buffer_append(&stderr_buffer, data, data_len);
1653 	memset(data, 0, data_len);
1654 	xfree(data);
1655 }
1656 static void
1657 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1658 {
1659 	exit_status = packet_get_int();
1660 	packet_check_eom();
1661 	/* Acknowledge the exit. */
1662 	packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1663 	packet_send();
1664 	/*
1665 	 * Must wait for packet to be sent since we are
1666 	 * exiting the loop.
1667 	 */
1668 	packet_write_wait();
1669 	/* Flag that we want to exit. */
1670 	quit_pending = 1;
1671 }
1672 static void
1673 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1674 {
1675 	Channel *c = NULL;
1676 	int remote_id, sock;
1677 
1678 	/* Read the remote channel number from the message. */
1679 	remote_id = packet_get_int();
1680 	packet_check_eom();
1681 
1682 	/*
1683 	 * Get a connection to the local authentication agent (this may again
1684 	 * get forwarded).
1685 	 */
1686 	sock = ssh_get_authentication_socket();
1687 
1688 	/*
1689 	 * If we could not connect the agent, send an error message back to
1690 	 * the server. This should never happen unless the agent dies,
1691 	 * because authentication forwarding is only enabled if we have an
1692 	 * agent.
1693 	 */
1694 	if (sock >= 0) {
1695 		c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1696 		    -1, 0, 0, 0, "authentication agent connection", 1);
1697 		c->remote_id = remote_id;
1698 		c->force_drain = 1;
1699 	}
1700 	if (c == NULL) {
1701 		packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1702 		packet_put_int(remote_id);
1703 	} else {
1704 		/* Send a confirmation to the remote host. */
1705 		debug("Forwarding authentication connection.");
1706 		packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1707 		packet_put_int(remote_id);
1708 		packet_put_int(c->self);
1709 	}
1710 	packet_send();
1711 }
1712 
1713 static Channel *
1714 client_request_forwarded_tcpip(const char *request_type, int rchan)
1715 {
1716 	Channel *c = NULL;
1717 	char *listen_address, *originator_address;
1718 	u_short listen_port, originator_port;
1719 
1720 	/* Get rest of the packet */
1721 	listen_address = packet_get_string(NULL);
1722 	listen_port = packet_get_int();
1723 	originator_address = packet_get_string(NULL);
1724 	originator_port = packet_get_int();
1725 	packet_check_eom();
1726 
1727 	debug("client_request_forwarded_tcpip: listen %s port %d, "
1728 	    "originator %s port %d", listen_address, listen_port,
1729 	    originator_address, originator_port);
1730 
1731 	c = channel_connect_by_listen_address(listen_port,
1732 	    "forwarded-tcpip", originator_address);
1733 
1734 	xfree(originator_address);
1735 	xfree(listen_address);
1736 	return c;
1737 }
1738 
1739 static Channel *
1740 client_request_x11(const char *request_type, int rchan)
1741 {
1742 	Channel *c = NULL;
1743 	char *originator;
1744 	u_short originator_port;
1745 	int sock;
1746 
1747 	if (!options.forward_x11) {
1748 		error("Warning: ssh server tried X11 forwarding.");
1749 		error("Warning: this is probably a break-in attempt by a "
1750 		    "malicious server.");
1751 		return NULL;
1752 	}
1753 	if (x11_refuse_time != 0 && time(NULL) >= x11_refuse_time) {
1754 		verbose("Rejected X11 connection after ForwardX11Timeout "
1755 		    "expired");
1756 		return NULL;
1757 	}
1758 	originator = packet_get_string(NULL);
1759 	if (datafellows & SSH_BUG_X11FWD) {
1760 		debug2("buggy server: x11 request w/o originator_port");
1761 		originator_port = 0;
1762 	} else {
1763 		originator_port = packet_get_int();
1764 	}
1765 	packet_check_eom();
1766 	/* XXX check permission */
1767 	debug("client_request_x11: request from %s %d", originator,
1768 	    originator_port);
1769 	xfree(originator);
1770 	sock = x11_connect_display();
1771 	if (sock < 0)
1772 		return NULL;
1773 	c = channel_new("x11",
1774 	    SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1775 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1776 	c->force_drain = 1;
1777 	return c;
1778 }
1779 
1780 static Channel *
1781 client_request_agent(const char *request_type, int rchan)
1782 {
1783 	Channel *c = NULL;
1784 	int sock;
1785 
1786 	if (!options.forward_agent) {
1787 		error("Warning: ssh server tried agent forwarding.");
1788 		error("Warning: this is probably a break-in attempt by a "
1789 		    "malicious server.");
1790 		return NULL;
1791 	}
1792 	sock = ssh_get_authentication_socket();
1793 	if (sock < 0)
1794 		return NULL;
1795 	c = channel_new("authentication agent connection",
1796 	    SSH_CHANNEL_OPEN, sock, sock, -1,
1797 	    CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1798 	    "authentication agent connection", 1);
1799 	c->force_drain = 1;
1800 	return c;
1801 }
1802 
1803 int
1804 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1805 {
1806 	Channel *c;
1807 	int fd;
1808 
1809 	if (tun_mode == SSH_TUNMODE_NO)
1810 		return 0;
1811 
1812 	if (!compat20) {
1813 		error("Tunnel forwarding is not supported for protocol 1");
1814 		return -1;
1815 	}
1816 
1817 	debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1818 
1819 	/* Open local tunnel device */
1820 	if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1821 		error("Tunnel device open failed.");
1822 		return -1;
1823 	}
1824 
1825 	c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1826 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1827 	c->datagram = 1;
1828 
1829 #if defined(SSH_TUN_FILTER)
1830 	if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1831 		channel_register_filter(c->self, sys_tun_infilter,
1832 		    sys_tun_outfilter, NULL, NULL);
1833 #endif
1834 
1835 	packet_start(SSH2_MSG_CHANNEL_OPEN);
1836 	packet_put_cstring("tun@openssh.com");
1837 	packet_put_int(c->self);
1838 	packet_put_int(c->local_window_max);
1839 	packet_put_int(c->local_maxpacket);
1840 	packet_put_int(tun_mode);
1841 	packet_put_int(remote_tun);
1842 	packet_send();
1843 
1844 	return 0;
1845 }
1846 
1847 /* XXXX move to generic input handler */
1848 static void
1849 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1850 {
1851 	Channel *c = NULL;
1852 	char *ctype;
1853 	int rchan;
1854 	u_int rmaxpack, rwindow, len;
1855 
1856 	ctype = packet_get_string(&len);
1857 	rchan = packet_get_int();
1858 	rwindow = packet_get_int();
1859 	rmaxpack = packet_get_int();
1860 
1861 	debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1862 	    ctype, rchan, rwindow, rmaxpack);
1863 
1864 	if (strcmp(ctype, "forwarded-tcpip") == 0) {
1865 		c = client_request_forwarded_tcpip(ctype, rchan);
1866 	} else if (strcmp(ctype, "x11") == 0) {
1867 		c = client_request_x11(ctype, rchan);
1868 	} else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1869 		c = client_request_agent(ctype, rchan);
1870 	}
1871 /* XXX duplicate : */
1872 	if (c != NULL) {
1873 		debug("confirm %s", ctype);
1874 		c->remote_id = rchan;
1875 		c->remote_window = rwindow;
1876 		c->remote_maxpacket = rmaxpack;
1877 		if (c->type != SSH_CHANNEL_CONNECTING) {
1878 			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1879 			packet_put_int(c->remote_id);
1880 			packet_put_int(c->self);
1881 			packet_put_int(c->local_window);
1882 			packet_put_int(c->local_maxpacket);
1883 			packet_send();
1884 		}
1885 	} else {
1886 		debug("failure %s", ctype);
1887 		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1888 		packet_put_int(rchan);
1889 		packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1890 		if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1891 			packet_put_cstring("open failed");
1892 			packet_put_cstring("");
1893 		}
1894 		packet_send();
1895 	}
1896 	xfree(ctype);
1897 }
1898 static void
1899 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1900 {
1901 	Channel *c = NULL;
1902 	int exitval, id, reply, success = 0;
1903 	char *rtype;
1904 
1905 	id = packet_get_int();
1906 	rtype = packet_get_string(NULL);
1907 	reply = packet_get_char();
1908 
1909 	debug("client_input_channel_req: channel %d rtype %s reply %d",
1910 	    id, rtype, reply);
1911 
1912 	if (id == -1) {
1913 		error("client_input_channel_req: request for channel -1");
1914 	} else if ((c = channel_lookup(id)) == NULL) {
1915 		error("client_input_channel_req: channel %d: "
1916 		    "unknown channel", id);
1917 	} else if (strcmp(rtype, "eow@openssh.com") == 0) {
1918 		packet_check_eom();
1919 		chan_rcvd_eow(c);
1920 	} else if (strcmp(rtype, "exit-status") == 0) {
1921 		exitval = packet_get_int();
1922 		if (c->ctl_chan != -1) {
1923 			mux_exit_message(c, exitval);
1924 			success = 1;
1925 		} else if (id == session_ident) {
1926 			/* Record exit value of local session */
1927 			success = 1;
1928 			exit_status = exitval;
1929 		} else {
1930 			/* Probably for a mux channel that has already closed */
1931 			debug("%s: no sink for exit-status on channel %d",
1932 			    __func__, id);
1933 		}
1934 		packet_check_eom();
1935 	}
1936 	if (reply) {
1937 		packet_start(success ?
1938 		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1939 		packet_put_int(c->remote_id);
1940 		packet_send();
1941 	}
1942 	xfree(rtype);
1943 }
1944 static void
1945 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1946 {
1947 	char *rtype;
1948 	int want_reply;
1949 	int success = 0;
1950 
1951 	rtype = packet_get_string(NULL);
1952 	want_reply = packet_get_char();
1953 	debug("client_input_global_request: rtype %s want_reply %d",
1954 	    rtype, want_reply);
1955 	if (want_reply) {
1956 		packet_start(success ?
1957 		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1958 		packet_send();
1959 		packet_write_wait();
1960 	}
1961 	xfree(rtype);
1962 }
1963 
1964 void
1965 client_session2_setup(int id, int want_tty, int want_subsystem,
1966     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
1967 {
1968 	int len;
1969 	Channel *c = NULL;
1970 
1971 	debug2("%s: id %d", __func__, id);
1972 
1973 	if ((c = channel_lookup(id)) == NULL)
1974 		fatal("client_session2_setup: channel %d: unknown channel", id);
1975 
1976 	if (want_tty) {
1977 		struct winsize ws;
1978 
1979 		/* Store window size in the packet. */
1980 		if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
1981 			memset(&ws, 0, sizeof(ws));
1982 
1983 		channel_request_start(id, "pty-req", 1);
1984 		client_expect_confirm(id, "PTY allocation", 1);
1985 		packet_put_cstring(term != NULL ? term : "");
1986 		packet_put_int((u_int)ws.ws_col);
1987 		packet_put_int((u_int)ws.ws_row);
1988 		packet_put_int((u_int)ws.ws_xpixel);
1989 		packet_put_int((u_int)ws.ws_ypixel);
1990 		if (tiop == NULL)
1991 			tiop = get_saved_tio();
1992 		tty_make_modes(-1, tiop);
1993 		packet_send();
1994 		/* XXX wait for reply */
1995 		c->client_tty = 1;
1996 	}
1997 
1998 	/* Transfer any environment variables from client to server */
1999 	if (options.num_send_env != 0 && env != NULL) {
2000 		int i, j, matched;
2001 		char *name, *val;
2002 
2003 		debug("Sending environment.");
2004 		for (i = 0; env[i] != NULL; i++) {
2005 			/* Split */
2006 			name = xstrdup(env[i]);
2007 			if ((val = strchr(name, '=')) == NULL) {
2008 				xfree(name);
2009 				continue;
2010 			}
2011 			*val++ = '\0';
2012 
2013 			matched = 0;
2014 			for (j = 0; j < options.num_send_env; j++) {
2015 				if (match_pattern(name, options.send_env[j])) {
2016 					matched = 1;
2017 					break;
2018 				}
2019 			}
2020 			if (!matched) {
2021 				debug3("Ignored env %s", name);
2022 				xfree(name);
2023 				continue;
2024 			}
2025 
2026 			debug("Sending env %s = %s", name, val);
2027 			channel_request_start(id, "env", 0);
2028 			packet_put_cstring(name);
2029 			packet_put_cstring(val);
2030 			packet_send();
2031 			xfree(name);
2032 		}
2033 	}
2034 
2035 	len = buffer_len(cmd);
2036 	if (len > 0) {
2037 		if (len > 900)
2038 			len = 900;
2039 		if (want_subsystem) {
2040 			debug("Sending subsystem: %.*s",
2041 			    len, (u_char*)buffer_ptr(cmd));
2042 			channel_request_start(id, "subsystem", 1);
2043 			client_expect_confirm(id, "subsystem", 1);
2044 		} else {
2045 			debug("Sending command: %.*s",
2046 			    len, (u_char*)buffer_ptr(cmd));
2047 			channel_request_start(id, "exec", 1);
2048 			client_expect_confirm(id, "exec", 1);
2049 		}
2050 		packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2051 		packet_send();
2052 	} else {
2053 		channel_request_start(id, "shell", 1);
2054 		client_expect_confirm(id, "shell", 1);
2055 		packet_send();
2056 	}
2057 }
2058 
2059 static void
2060 client_init_dispatch_20(void)
2061 {
2062 	dispatch_init(&dispatch_protocol_error);
2063 
2064 	dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2065 	dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2066 	dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2067 	dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2068 	dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2069 	dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2070 	dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2071 	dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2072 	dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2073 	dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2074 	dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2075 	dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2076 
2077 	/* rekeying */
2078 	dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2079 
2080 	/* global request reply messages */
2081 	dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2082 	dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2083 }
2084 
2085 static void
2086 client_init_dispatch_13(void)
2087 {
2088 	dispatch_init(NULL);
2089 	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2090 	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2091 	dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2092 	dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2093 	dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2094 	dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2095 	dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2096 	dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2097 	dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2098 
2099 	dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2100 	    &client_input_agent_open : &deny_input_open);
2101 	dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2102 	    &x11_input_open : &deny_input_open);
2103 }
2104 
2105 static void
2106 client_init_dispatch_15(void)
2107 {
2108 	client_init_dispatch_13();
2109 	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2110 	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2111 }
2112 
2113 static void
2114 client_init_dispatch(void)
2115 {
2116 	if (compat20)
2117 		client_init_dispatch_20();
2118 	else if (compat13)
2119 		client_init_dispatch_13();
2120 	else
2121 		client_init_dispatch_15();
2122 }
2123 
2124 /* client specific fatal cleanup */
2125 void
2126 cleanup_exit(int i)
2127 {
2128 	leave_raw_mode(force_tty_flag);
2129 	leave_non_blocking();
2130 	if (options.control_path != NULL && muxserver_sock != -1)
2131 		unlink(options.control_path);
2132 	_exit(i);
2133 }
2134