xref: /freebsd/crypto/openssh/clientloop.c (revision c243e4902be8df1e643c76b5f18b68bb77cc5268)
1 /* $OpenBSD: clientloop.c,v 1.240 2012/06/20 04:42:58 djm Exp $ */
2 /* $FreeBSD$ */
3 /*
4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6  *                    All rights reserved
7  * The main loop for the interactive session (client side).
8  *
9  * As far as I am concerned, the code I have written for this software
10  * can be used freely for any purpose.  Any derived versions of this
11  * software must be clearly marked as such, and if the derived work is
12  * incompatible with the protocol description in the RFC file, it must be
13  * called by a name other than "ssh" or "Secure Shell".
14  *
15  *
16  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
17  *
18  * Redistribution and use in source and binary forms, with or without
19  * modification, are permitted provided that the following conditions
20  * are met:
21  * 1. Redistributions of source code must retain the above copyright
22  *    notice, this list of conditions and the following disclaimer.
23  * 2. Redistributions in binary form must reproduce the above copyright
24  *    notice, this list of conditions and the following disclaimer in the
25  *    documentation and/or other materials provided with the distribution.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
28  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
31  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
32  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37  *
38  *
39  * SSH2 support added by Markus Friedl.
40  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
41  *
42  * Redistribution and use in source and binary forms, with or without
43  * modification, are permitted provided that the following conditions
44  * are met:
45  * 1. Redistributions of source code must retain the above copyright
46  *    notice, this list of conditions and the following disclaimer.
47  * 2. Redistributions in binary form must reproduce the above copyright
48  *    notice, this list of conditions and the following disclaimer in the
49  *    documentation and/or other materials provided with the distribution.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61  */
62 
63 #include "includes.h"
64 
65 #include <sys/types.h>
66 #include <sys/ioctl.h>
67 #include <sys/param.h>
68 #ifdef HAVE_SYS_STAT_H
69 # include <sys/stat.h>
70 #endif
71 #ifdef HAVE_SYS_TIME_H
72 # include <sys/time.h>
73 #endif
74 #include <sys/socket.h>
75 
76 #include <ctype.h>
77 #include <errno.h>
78 #ifdef HAVE_PATHS_H
79 #include <paths.h>
80 #endif
81 #include <signal.h>
82 #include <stdarg.h>
83 #include <stdio.h>
84 #include <stdlib.h>
85 #include <string.h>
86 #include <termios.h>
87 #include <pwd.h>
88 #include <unistd.h>
89 
90 #include "openbsd-compat/sys-queue.h"
91 #include "xmalloc.h"
92 #include "ssh.h"
93 #include "ssh1.h"
94 #include "ssh2.h"
95 #include "packet.h"
96 #include "buffer.h"
97 #include "compat.h"
98 #include "channels.h"
99 #include "dispatch.h"
100 #include "key.h"
101 #include "cipher.h"
102 #include "kex.h"
103 #include "log.h"
104 #include "readconf.h"
105 #include "clientloop.h"
106 #include "sshconnect.h"
107 #include "authfd.h"
108 #include "atomicio.h"
109 #include "sshpty.h"
110 #include "misc.h"
111 #include "match.h"
112 #include "msg.h"
113 #include "roaming.h"
114 
115 /* import options */
116 extern Options options;
117 
118 /* Flag indicating that stdin should be redirected from /dev/null. */
119 extern int stdin_null_flag;
120 
121 /* Flag indicating that no shell has been requested */
122 extern int no_shell_flag;
123 
124 /* Control socket */
125 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
126 
127 /*
128  * Name of the host we are connecting to.  This is the name given on the
129  * command line, or the HostName specified for the user-supplied name in a
130  * configuration file.
131  */
132 extern char *host;
133 
134 /*
135  * Flag to indicate that we have received a window change signal which has
136  * not yet been processed.  This will cause a message indicating the new
137  * window size to be sent to the server a little later.  This is volatile
138  * because this is updated in a signal handler.
139  */
140 static volatile sig_atomic_t received_window_change_signal = 0;
141 static volatile sig_atomic_t received_signal = 0;
142 
143 /* Flag indicating whether the user's terminal is in non-blocking mode. */
144 static int in_non_blocking_mode = 0;
145 
146 /* Time when backgrounded control master using ControlPersist should exit */
147 static time_t control_persist_exit_time = 0;
148 
149 /* Common data for the client loop code. */
150 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
151 static int escape_char1;	/* Escape character. (proto1 only) */
152 static int escape_pending1;	/* Last character was an escape (proto1 only) */
153 static int last_was_cr;		/* Last character was a newline. */
154 static int exit_status;		/* Used to store the command exit status. */
155 static int stdin_eof;		/* EOF has been encountered on stderr. */
156 static Buffer stdin_buffer;	/* Buffer for stdin data. */
157 static Buffer stdout_buffer;	/* Buffer for stdout data. */
158 static Buffer stderr_buffer;	/* Buffer for stderr data. */
159 static u_int buffer_high;	/* Soft max buffer size. */
160 static int connection_in;	/* Connection to server (input). */
161 static int connection_out;	/* Connection to server (output). */
162 static int need_rekeying;	/* Set to non-zero if rekeying is requested. */
163 static int session_closed;	/* In SSH2: login session closed. */
164 static int x11_refuse_time;	/* If >0, refuse x11 opens after this time. */
165 
166 static void client_init_dispatch(void);
167 int	session_ident = -1;
168 
169 int	session_resumed = 0;
170 
171 /* Track escape per proto2 channel */
172 struct escape_filter_ctx {
173 	int escape_pending;
174 	int escape_char;
175 };
176 
177 /* Context for channel confirmation replies */
178 struct channel_reply_ctx {
179 	const char *request_type;
180 	int id;
181 	enum confirm_action action;
182 };
183 
184 /* Global request success/failure callbacks */
185 struct global_confirm {
186 	TAILQ_ENTRY(global_confirm) entry;
187 	global_confirm_cb *cb;
188 	void *ctx;
189 	int ref_count;
190 };
191 TAILQ_HEAD(global_confirms, global_confirm);
192 static struct global_confirms global_confirms =
193     TAILQ_HEAD_INITIALIZER(global_confirms);
194 
195 /*XXX*/
196 extern Kex *xxx_kex;
197 
198 void ssh_process_session2_setup(int, int, int, Buffer *);
199 
200 /* Restores stdin to blocking mode. */
201 
202 static void
203 leave_non_blocking(void)
204 {
205 	if (in_non_blocking_mode) {
206 		unset_nonblock(fileno(stdin));
207 		in_non_blocking_mode = 0;
208 	}
209 }
210 
211 /* Puts stdin terminal in non-blocking mode. */
212 
213 static void
214 enter_non_blocking(void)
215 {
216 	in_non_blocking_mode = 1;
217 	set_nonblock(fileno(stdin));
218 }
219 
220 /*
221  * Signal handler for the window change signal (SIGWINCH).  This just sets a
222  * flag indicating that the window has changed.
223  */
224 /*ARGSUSED */
225 static void
226 window_change_handler(int sig)
227 {
228 	received_window_change_signal = 1;
229 	signal(SIGWINCH, window_change_handler);
230 }
231 
232 /*
233  * Signal handler for signals that cause the program to terminate.  These
234  * signals must be trapped to restore terminal modes.
235  */
236 /*ARGSUSED */
237 static void
238 signal_handler(int sig)
239 {
240 	received_signal = sig;
241 	quit_pending = 1;
242 }
243 
244 /*
245  * Returns current time in seconds from Jan 1, 1970 with the maximum
246  * available resolution.
247  */
248 
249 static double
250 get_current_time(void)
251 {
252 	struct timeval tv;
253 	gettimeofday(&tv, NULL);
254 	return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
255 }
256 
257 /*
258  * Sets control_persist_exit_time to the absolute time when the
259  * backgrounded control master should exit due to expiry of the
260  * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
261  * control master process, or if there is no ControlPersist timeout.
262  */
263 static void
264 set_control_persist_exit_time(void)
265 {
266 	if (muxserver_sock == -1 || !options.control_persist
267 	    || options.control_persist_timeout == 0) {
268 		/* not using a ControlPersist timeout */
269 		control_persist_exit_time = 0;
270 	} else if (channel_still_open()) {
271 		/* some client connections are still open */
272 		if (control_persist_exit_time > 0)
273 			debug2("%s: cancel scheduled exit", __func__);
274 		control_persist_exit_time = 0;
275 	} else if (control_persist_exit_time <= 0) {
276 		/* a client connection has recently closed */
277 		control_persist_exit_time = time(NULL) +
278 			(time_t)options.control_persist_timeout;
279 		debug2("%s: schedule exit in %d seconds", __func__,
280 		    options.control_persist_timeout);
281 	}
282 	/* else we are already counting down to the timeout */
283 }
284 
285 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_"
286 static int
287 client_x11_display_valid(const char *display)
288 {
289 	size_t i, dlen;
290 
291 	dlen = strlen(display);
292 	for (i = 0; i < dlen; i++) {
293 		if (!isalnum(display[i]) &&
294 		    strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) {
295 			debug("Invalid character '%c' in DISPLAY", display[i]);
296 			return 0;
297 		}
298 	}
299 	return 1;
300 }
301 
302 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
303 void
304 client_x11_get_proto(const char *display, const char *xauth_path,
305     u_int trusted, u_int timeout, char **_proto, char **_data)
306 {
307 	char cmd[1024];
308 	char line[512];
309 	char xdisplay[512];
310 	static char proto[512], data[512];
311 	FILE *f;
312 	int got_data = 0, generated = 0, do_unlink = 0, i;
313 	char *xauthdir, *xauthfile;
314 	struct stat st;
315 	u_int now;
316 
317 	xauthdir = xauthfile = NULL;
318 	*_proto = proto;
319 	*_data = data;
320 	proto[0] = data[0] = '\0';
321 
322 	if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
323 		debug("No xauth program.");
324 	} else if (!client_x11_display_valid(display)) {
325 		logit("DISPLAY '%s' invalid, falling back to fake xauth data",
326 		    display);
327 	} else {
328 		if (display == NULL) {
329 			debug("x11_get_proto: DISPLAY not set");
330 			return;
331 		}
332 		/*
333 		 * Handle FamilyLocal case where $DISPLAY does
334 		 * not match an authorization entry.  For this we
335 		 * just try "xauth list unix:displaynum.screennum".
336 		 * XXX: "localhost" match to determine FamilyLocal
337 		 *      is not perfect.
338 		 */
339 		if (strncmp(display, "localhost:", 10) == 0) {
340 			snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
341 			    display + 10);
342 			display = xdisplay;
343 		}
344 		if (trusted == 0) {
345 			xauthdir = xmalloc(MAXPATHLEN);
346 			xauthfile = xmalloc(MAXPATHLEN);
347 			mktemp_proto(xauthdir, MAXPATHLEN);
348 			if (mkdtemp(xauthdir) != NULL) {
349 				do_unlink = 1;
350 				snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
351 				    xauthdir);
352 				snprintf(cmd, sizeof(cmd),
353 				    "%s -f %s generate %s " SSH_X11_PROTO
354 				    " untrusted timeout %u 2>" _PATH_DEVNULL,
355 				    xauth_path, xauthfile, display, timeout);
356 				debug2("x11_get_proto: %s", cmd);
357 				if (system(cmd) == 0)
358 					generated = 1;
359 				if (x11_refuse_time == 0) {
360 					now = time(NULL) + 1;
361 					if (UINT_MAX - timeout < now)
362 						x11_refuse_time = UINT_MAX;
363 					else
364 						x11_refuse_time = now + timeout;
365 				}
366 			}
367 		}
368 
369 		/*
370 		 * When in untrusted mode, we read the cookie only if it was
371 		 * successfully generated as an untrusted one in the step
372 		 * above.
373 		 */
374 		if (trusted || generated) {
375 			snprintf(cmd, sizeof(cmd),
376 			    "%s %s%s list %s 2>" _PATH_DEVNULL,
377 			    xauth_path,
378 			    generated ? "-f " : "" ,
379 			    generated ? xauthfile : "",
380 			    display);
381 			debug2("x11_get_proto: %s", cmd);
382 			f = popen(cmd, "r");
383 			if (f && fgets(line, sizeof(line), f) &&
384 			    sscanf(line, "%*s %511s %511s", proto, data) == 2)
385 				got_data = 1;
386 			if (f)
387 				pclose(f);
388 		} else
389 			error("Warning: untrusted X11 forwarding setup failed: "
390 			    "xauth key data not generated");
391 	}
392 
393 	if (do_unlink) {
394 		unlink(xauthfile);
395 		rmdir(xauthdir);
396 	}
397 	if (xauthdir)
398 		xfree(xauthdir);
399 	if (xauthfile)
400 		xfree(xauthfile);
401 
402 	/*
403 	 * If we didn't get authentication data, just make up some
404 	 * data.  The forwarding code will check the validity of the
405 	 * response anyway, and substitute this data.  The X11
406 	 * server, however, will ignore this fake data and use
407 	 * whatever authentication mechanisms it was using otherwise
408 	 * for the local connection.
409 	 */
410 	if (!got_data) {
411 		u_int32_t rnd = 0;
412 
413 		logit("Warning: No xauth data; "
414 		    "using fake authentication data for X11 forwarding.");
415 		strlcpy(proto, SSH_X11_PROTO, sizeof proto);
416 		for (i = 0; i < 16; i++) {
417 			if (i % 4 == 0)
418 				rnd = arc4random();
419 			snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
420 			    rnd & 0xff);
421 			rnd >>= 8;
422 		}
423 	}
424 }
425 
426 /*
427  * This is called when the interactive is entered.  This checks if there is
428  * an EOF coming on stdin.  We must check this explicitly, as select() does
429  * not appear to wake up when redirecting from /dev/null.
430  */
431 
432 static void
433 client_check_initial_eof_on_stdin(void)
434 {
435 	int len;
436 	char buf[1];
437 
438 	/*
439 	 * If standard input is to be "redirected from /dev/null", we simply
440 	 * mark that we have seen an EOF and send an EOF message to the
441 	 * server. Otherwise, we try to read a single character; it appears
442 	 * that for some files, such /dev/null, select() never wakes up for
443 	 * read for this descriptor, which means that we never get EOF.  This
444 	 * way we will get the EOF if stdin comes from /dev/null or similar.
445 	 */
446 	if (stdin_null_flag) {
447 		/* Fake EOF on stdin. */
448 		debug("Sending eof.");
449 		stdin_eof = 1;
450 		packet_start(SSH_CMSG_EOF);
451 		packet_send();
452 	} else {
453 		enter_non_blocking();
454 
455 		/* Check for immediate EOF on stdin. */
456 		len = read(fileno(stdin), buf, 1);
457 		if (len == 0) {
458 			/*
459 			 * EOF.  Record that we have seen it and send
460 			 * EOF to server.
461 			 */
462 			debug("Sending eof.");
463 			stdin_eof = 1;
464 			packet_start(SSH_CMSG_EOF);
465 			packet_send();
466 		} else if (len > 0) {
467 			/*
468 			 * Got data.  We must store the data in the buffer,
469 			 * and also process it as an escape character if
470 			 * appropriate.
471 			 */
472 			if ((u_char) buf[0] == escape_char1)
473 				escape_pending1 = 1;
474 			else
475 				buffer_append(&stdin_buffer, buf, 1);
476 		}
477 		leave_non_blocking();
478 	}
479 }
480 
481 
482 /*
483  * Make packets from buffered stdin data, and buffer them for sending to the
484  * connection.
485  */
486 
487 static void
488 client_make_packets_from_stdin_data(void)
489 {
490 	u_int len;
491 
492 	/* Send buffered stdin data to the server. */
493 	while (buffer_len(&stdin_buffer) > 0 &&
494 	    packet_not_very_much_data_to_write()) {
495 		len = buffer_len(&stdin_buffer);
496 		/* Keep the packets at reasonable size. */
497 		if (len > packet_get_maxsize())
498 			len = packet_get_maxsize();
499 		packet_start(SSH_CMSG_STDIN_DATA);
500 		packet_put_string(buffer_ptr(&stdin_buffer), len);
501 		packet_send();
502 		buffer_consume(&stdin_buffer, len);
503 		/* If we have a pending EOF, send it now. */
504 		if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
505 			packet_start(SSH_CMSG_EOF);
506 			packet_send();
507 		}
508 	}
509 }
510 
511 /*
512  * Checks if the client window has changed, and sends a packet about it to
513  * the server if so.  The actual change is detected elsewhere (by a software
514  * interrupt on Unix); this just checks the flag and sends a message if
515  * appropriate.
516  */
517 
518 static void
519 client_check_window_change(void)
520 {
521 	struct winsize ws;
522 
523 	if (! received_window_change_signal)
524 		return;
525 	/** XXX race */
526 	received_window_change_signal = 0;
527 
528 	debug2("client_check_window_change: changed");
529 
530 	if (compat20) {
531 		channel_send_window_changes();
532 	} else {
533 		if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
534 			return;
535 		packet_start(SSH_CMSG_WINDOW_SIZE);
536 		packet_put_int((u_int)ws.ws_row);
537 		packet_put_int((u_int)ws.ws_col);
538 		packet_put_int((u_int)ws.ws_xpixel);
539 		packet_put_int((u_int)ws.ws_ypixel);
540 		packet_send();
541 	}
542 }
543 
544 static void
545 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
546 {
547 	struct global_confirm *gc;
548 
549 	if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
550 		return;
551 	if (gc->cb != NULL)
552 		gc->cb(type, seq, gc->ctx);
553 	if (--gc->ref_count <= 0) {
554 		TAILQ_REMOVE(&global_confirms, gc, entry);
555 		bzero(gc, sizeof(*gc));
556 		xfree(gc);
557 	}
558 
559 	packet_set_alive_timeouts(0);
560 }
561 
562 static void
563 server_alive_check(void)
564 {
565 	if (packet_inc_alive_timeouts() > options.server_alive_count_max) {
566 		logit("Timeout, server %s not responding.", host);
567 		cleanup_exit(255);
568 	}
569 	packet_start(SSH2_MSG_GLOBAL_REQUEST);
570 	packet_put_cstring("keepalive@openssh.com");
571 	packet_put_char(1);     /* boolean: want reply */
572 	packet_send();
573 	/* Insert an empty placeholder to maintain ordering */
574 	client_register_global_confirm(NULL, NULL);
575 }
576 
577 /*
578  * Waits until the client can do something (some data becomes available on
579  * one of the file descriptors).
580  */
581 static void
582 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
583     int *maxfdp, u_int *nallocp, int rekeying)
584 {
585 	struct timeval tv, *tvp;
586 	int timeout_secs;
587 	time_t minwait_secs = 0;
588 	int ret;
589 
590 	/* Add any selections by the channel mechanism. */
591 	channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
592 	    &minwait_secs, rekeying);
593 
594 	if (!compat20) {
595 		/* Read from the connection, unless our buffers are full. */
596 		if (buffer_len(&stdout_buffer) < buffer_high &&
597 		    buffer_len(&stderr_buffer) < buffer_high &&
598 		    channel_not_very_much_buffered_data())
599 			FD_SET(connection_in, *readsetp);
600 		/*
601 		 * Read from stdin, unless we have seen EOF or have very much
602 		 * buffered data to send to the server.
603 		 */
604 		if (!stdin_eof && packet_not_very_much_data_to_write())
605 			FD_SET(fileno(stdin), *readsetp);
606 
607 		/* Select stdout/stderr if have data in buffer. */
608 		if (buffer_len(&stdout_buffer) > 0)
609 			FD_SET(fileno(stdout), *writesetp);
610 		if (buffer_len(&stderr_buffer) > 0)
611 			FD_SET(fileno(stderr), *writesetp);
612 	} else {
613 		/* channel_prepare_select could have closed the last channel */
614 		if (session_closed && !channel_still_open() &&
615 		    !packet_have_data_to_write()) {
616 			/* clear mask since we did not call select() */
617 			memset(*readsetp, 0, *nallocp);
618 			memset(*writesetp, 0, *nallocp);
619 			return;
620 		} else {
621 			FD_SET(connection_in, *readsetp);
622 		}
623 	}
624 
625 	/* Select server connection if have data to write to the server. */
626 	if (packet_have_data_to_write())
627 		FD_SET(connection_out, *writesetp);
628 
629 	/*
630 	 * Wait for something to happen.  This will suspend the process until
631 	 * some selected descriptor can be read, written, or has some other
632 	 * event pending, or a timeout expires.
633 	 */
634 
635 	timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
636 	if (options.server_alive_interval > 0 && compat20)
637 		timeout_secs = options.server_alive_interval;
638 	set_control_persist_exit_time();
639 	if (control_persist_exit_time > 0) {
640 		timeout_secs = MIN(timeout_secs,
641 			control_persist_exit_time - time(NULL));
642 		if (timeout_secs < 0)
643 			timeout_secs = 0;
644 	}
645 	if (minwait_secs != 0)
646 		timeout_secs = MIN(timeout_secs, (int)minwait_secs);
647 	if (timeout_secs == INT_MAX)
648 		tvp = NULL;
649 	else {
650 		tv.tv_sec = timeout_secs;
651 		tv.tv_usec = 0;
652 		tvp = &tv;
653 	}
654 
655 	ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
656 	if (ret < 0) {
657 		char buf[100];
658 
659 		/*
660 		 * We have to clear the select masks, because we return.
661 		 * We have to return, because the mainloop checks for the flags
662 		 * set by the signal handlers.
663 		 */
664 		memset(*readsetp, 0, *nallocp);
665 		memset(*writesetp, 0, *nallocp);
666 
667 		if (errno == EINTR)
668 			return;
669 		/* Note: we might still have data in the buffers. */
670 		snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
671 		buffer_append(&stderr_buffer, buf, strlen(buf));
672 		quit_pending = 1;
673 	} else if (ret == 0)
674 		server_alive_check();
675 }
676 
677 static void
678 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
679 {
680 	/* Flush stdout and stderr buffers. */
681 	if (buffer_len(bout) > 0)
682 		atomicio(vwrite, fileno(stdout), buffer_ptr(bout),
683 		    buffer_len(bout));
684 	if (buffer_len(berr) > 0)
685 		atomicio(vwrite, fileno(stderr), buffer_ptr(berr),
686 		    buffer_len(berr));
687 
688 	leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
689 
690 	/*
691 	 * Free (and clear) the buffer to reduce the amount of data that gets
692 	 * written to swap.
693 	 */
694 	buffer_free(bin);
695 	buffer_free(bout);
696 	buffer_free(berr);
697 
698 	/* Send the suspend signal to the program itself. */
699 	kill(getpid(), SIGTSTP);
700 
701 	/* Reset window sizes in case they have changed */
702 	received_window_change_signal = 1;
703 
704 	/* OK, we have been continued by the user. Reinitialize buffers. */
705 	buffer_init(bin);
706 	buffer_init(bout);
707 	buffer_init(berr);
708 
709 	enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
710 }
711 
712 static void
713 client_process_net_input(fd_set *readset)
714 {
715 	int len, cont = 0;
716 	char buf[SSH_IOBUFSZ];
717 
718 	/*
719 	 * Read input from the server, and add any such data to the buffer of
720 	 * the packet subsystem.
721 	 */
722 	if (FD_ISSET(connection_in, readset)) {
723 		/* Read as much as possible. */
724 		len = roaming_read(connection_in, buf, sizeof(buf), &cont);
725 		if (len == 0 && cont == 0) {
726 			/*
727 			 * Received EOF.  The remote host has closed the
728 			 * connection.
729 			 */
730 			snprintf(buf, sizeof buf,
731 			    "Connection to %.300s closed by remote host.\r\n",
732 			    host);
733 			buffer_append(&stderr_buffer, buf, strlen(buf));
734 			quit_pending = 1;
735 			return;
736 		}
737 		/*
738 		 * There is a kernel bug on Solaris that causes select to
739 		 * sometimes wake up even though there is no data available.
740 		 */
741 		if (len < 0 &&
742 		    (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
743 			len = 0;
744 
745 		if (len < 0) {
746 			/*
747 			 * An error has encountered.  Perhaps there is a
748 			 * network problem.
749 			 */
750 			snprintf(buf, sizeof buf,
751 			    "Read from remote host %.300s: %.100s\r\n",
752 			    host, strerror(errno));
753 			buffer_append(&stderr_buffer, buf, strlen(buf));
754 			quit_pending = 1;
755 			return;
756 		}
757 		packet_process_incoming(buf, len);
758 	}
759 }
760 
761 static void
762 client_status_confirm(int type, Channel *c, void *ctx)
763 {
764 	struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
765 	char errmsg[256];
766 	int tochan;
767 
768 	/*
769 	 * If a TTY was explicitly requested, then a failure to allocate
770 	 * one is fatal.
771 	 */
772 	if (cr->action == CONFIRM_TTY &&
773 	    (options.request_tty == REQUEST_TTY_FORCE ||
774 	    options.request_tty == REQUEST_TTY_YES))
775 		cr->action = CONFIRM_CLOSE;
776 
777 	/* XXX supress on mux _client_ quietmode */
778 	tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
779 	    c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
780 
781 	if (type == SSH2_MSG_CHANNEL_SUCCESS) {
782 		debug2("%s request accepted on channel %d",
783 		    cr->request_type, c->self);
784 	} else if (type == SSH2_MSG_CHANNEL_FAILURE) {
785 		if (tochan) {
786 			snprintf(errmsg, sizeof(errmsg),
787 			    "%s request failed\r\n", cr->request_type);
788 		} else {
789 			snprintf(errmsg, sizeof(errmsg),
790 			    "%s request failed on channel %d",
791 			    cr->request_type, c->self);
792 		}
793 		/* If error occurred on primary session channel, then exit */
794 		if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
795 			fatal("%s", errmsg);
796 		/*
797 		 * If error occurred on mux client, append to
798 		 * their stderr.
799 		 */
800 		if (tochan) {
801 			buffer_append(&c->extended, errmsg,
802 			    strlen(errmsg));
803 		} else
804 			error("%s", errmsg);
805 		if (cr->action == CONFIRM_TTY) {
806 			/*
807 			 * If a TTY allocation error occurred, then arrange
808 			 * for the correct TTY to leave raw mode.
809 			 */
810 			if (c->self == session_ident)
811 				leave_raw_mode(0);
812 			else
813 				mux_tty_alloc_failed(c);
814 		} else if (cr->action == CONFIRM_CLOSE) {
815 			chan_read_failed(c);
816 			chan_write_failed(c);
817 		}
818 	}
819 	xfree(cr);
820 }
821 
822 static void
823 client_abandon_status_confirm(Channel *c, void *ctx)
824 {
825 	xfree(ctx);
826 }
827 
828 void
829 client_expect_confirm(int id, const char *request,
830     enum confirm_action action)
831 {
832 	struct channel_reply_ctx *cr = xmalloc(sizeof(*cr));
833 
834 	cr->request_type = request;
835 	cr->action = action;
836 
837 	channel_register_status_confirm(id, client_status_confirm,
838 	    client_abandon_status_confirm, cr);
839 }
840 
841 void
842 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
843 {
844 	struct global_confirm *gc, *last_gc;
845 
846 	/* Coalesce identical callbacks */
847 	last_gc = TAILQ_LAST(&global_confirms, global_confirms);
848 	if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
849 		if (++last_gc->ref_count >= INT_MAX)
850 			fatal("%s: last_gc->ref_count = %d",
851 			    __func__, last_gc->ref_count);
852 		return;
853 	}
854 
855 	gc = xmalloc(sizeof(*gc));
856 	gc->cb = cb;
857 	gc->ctx = ctx;
858 	gc->ref_count = 1;
859 	TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
860 }
861 
862 static void
863 process_cmdline(void)
864 {
865 	void (*handler)(int);
866 	char *s, *cmd, *cancel_host;
867 	int delete = 0, local = 0, remote = 0, dynamic = 0;
868 	int cancel_port, ok;
869 	Forward fwd;
870 
871 	bzero(&fwd, sizeof(fwd));
872 	fwd.listen_host = fwd.connect_host = NULL;
873 
874 	leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
875 	handler = signal(SIGINT, SIG_IGN);
876 	cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
877 	if (s == NULL)
878 		goto out;
879 	while (isspace(*s))
880 		s++;
881 	if (*s == '-')
882 		s++;	/* Skip cmdline '-', if any */
883 	if (*s == '\0')
884 		goto out;
885 
886 	if (*s == 'h' || *s == 'H' || *s == '?') {
887 		logit("Commands:");
888 		logit("      -L[bind_address:]port:host:hostport    "
889 		    "Request local forward");
890 		logit("      -R[bind_address:]port:host:hostport    "
891 		    "Request remote forward");
892 		logit("      -D[bind_address:]port                  "
893 		    "Request dynamic forward");
894 		logit("      -KL[bind_address:]port                 "
895 		    "Cancel local forward");
896 		logit("      -KR[bind_address:]port                 "
897 		    "Cancel remote forward");
898 		logit("      -KD[bind_address:]port                 "
899 		    "Cancel dynamic forward");
900 		if (!options.permit_local_command)
901 			goto out;
902 		logit("      !args                                  "
903 		    "Execute local command");
904 		goto out;
905 	}
906 
907 	if (*s == '!' && options.permit_local_command) {
908 		s++;
909 		ssh_local_cmd(s);
910 		goto out;
911 	}
912 
913 	if (*s == 'K') {
914 		delete = 1;
915 		s++;
916 	}
917 	if (*s == 'L')
918 		local = 1;
919 	else if (*s == 'R')
920 		remote = 1;
921 	else if (*s == 'D')
922 		dynamic = 1;
923 	else {
924 		logit("Invalid command.");
925 		goto out;
926 	}
927 
928 	if (delete && !compat20) {
929 		logit("Not supported for SSH protocol version 1.");
930 		goto out;
931 	}
932 
933 	while (isspace(*++s))
934 		;
935 
936 	/* XXX update list of forwards in options */
937 	if (delete) {
938 		cancel_port = 0;
939 		cancel_host = hpdelim(&s);	/* may be NULL */
940 		if (s != NULL) {
941 			cancel_port = a2port(s);
942 			cancel_host = cleanhostname(cancel_host);
943 		} else {
944 			cancel_port = a2port(cancel_host);
945 			cancel_host = NULL;
946 		}
947 		if (cancel_port <= 0) {
948 			logit("Bad forwarding close port");
949 			goto out;
950 		}
951 		if (remote)
952 			ok = channel_request_rforward_cancel(cancel_host,
953 			    cancel_port) == 0;
954 		else if (dynamic)
955                 	ok = channel_cancel_lport_listener(cancel_host,
956 			    cancel_port, 0, options.gateway_ports) > 0;
957 		else
958                 	ok = channel_cancel_lport_listener(cancel_host,
959 			    cancel_port, CHANNEL_CANCEL_PORT_STATIC,
960 			    options.gateway_ports) > 0;
961 		if (!ok) {
962 			logit("Unkown port forwarding.");
963 			goto out;
964 		}
965 		logit("Canceled forwarding.");
966 	} else {
967 		if (!parse_forward(&fwd, s, dynamic, remote)) {
968 			logit("Bad forwarding specification.");
969 			goto out;
970 		}
971 		if (local || dynamic) {
972 			if (channel_setup_local_fwd_listener(fwd.listen_host,
973 			    fwd.listen_port, fwd.connect_host,
974 			    fwd.connect_port, options.gateway_ports) < 0) {
975 				logit("Port forwarding failed.");
976 				goto out;
977 			}
978 		} else {
979 			if (channel_request_remote_forwarding(fwd.listen_host,
980 			    fwd.listen_port, fwd.connect_host,
981 			    fwd.connect_port) < 0) {
982 				logit("Port forwarding failed.");
983 				goto out;
984 			}
985 		}
986 		logit("Forwarding port.");
987 	}
988 
989 out:
990 	signal(SIGINT, handler);
991 	enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
992 	if (cmd)
993 		xfree(cmd);
994 	if (fwd.listen_host != NULL)
995 		xfree(fwd.listen_host);
996 	if (fwd.connect_host != NULL)
997 		xfree(fwd.connect_host);
998 }
999 
1000 /*
1001  * Process the characters one by one, call with c==NULL for proto1 case.
1002  */
1003 static int
1004 process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
1005     char *buf, int len)
1006 {
1007 	char string[1024];
1008 	pid_t pid;
1009 	int bytes = 0;
1010 	u_int i;
1011 	u_char ch;
1012 	char *s;
1013 	int *escape_pendingp, escape_char;
1014 	struct escape_filter_ctx *efc;
1015 
1016 	if (c == NULL) {
1017 		escape_pendingp = &escape_pending1;
1018 		escape_char = escape_char1;
1019 	} else {
1020 		if (c->filter_ctx == NULL)
1021 			return 0;
1022 		efc = (struct escape_filter_ctx *)c->filter_ctx;
1023 		escape_pendingp = &efc->escape_pending;
1024 		escape_char = efc->escape_char;
1025 	}
1026 
1027 	if (len <= 0)
1028 		return (0);
1029 
1030 	for (i = 0; i < (u_int)len; i++) {
1031 		/* Get one character at a time. */
1032 		ch = buf[i];
1033 
1034 		if (*escape_pendingp) {
1035 			/* We have previously seen an escape character. */
1036 			/* Clear the flag now. */
1037 			*escape_pendingp = 0;
1038 
1039 			/* Process the escaped character. */
1040 			switch (ch) {
1041 			case '.':
1042 				/* Terminate the connection. */
1043 				snprintf(string, sizeof string, "%c.\r\n",
1044 				    escape_char);
1045 				buffer_append(berr, string, strlen(string));
1046 
1047 				if (c && c->ctl_chan != -1) {
1048 					chan_read_failed(c);
1049 					chan_write_failed(c);
1050 					return 0;
1051 				} else
1052 					quit_pending = 1;
1053 				return -1;
1054 
1055 			case 'Z' - 64:
1056 				/* XXX support this for mux clients */
1057 				if (c && c->ctl_chan != -1) {
1058  noescape:
1059 					snprintf(string, sizeof string,
1060 					    "%c%c escape not available to "
1061 					    "multiplexed sessions\r\n",
1062 					    escape_char, ch);
1063 					buffer_append(berr, string,
1064 					    strlen(string));
1065 					continue;
1066 				}
1067 				/* Suspend the program. Inform the user */
1068 				snprintf(string, sizeof string,
1069 				    "%c^Z [suspend ssh]\r\n", escape_char);
1070 				buffer_append(berr, string, strlen(string));
1071 
1072 				/* Restore terminal modes and suspend. */
1073 				client_suspend_self(bin, bout, berr);
1074 
1075 				/* We have been continued. */
1076 				continue;
1077 
1078 			case 'B':
1079 				if (compat20) {
1080 					snprintf(string, sizeof string,
1081 					    "%cB\r\n", escape_char);
1082 					buffer_append(berr, string,
1083 					    strlen(string));
1084 					channel_request_start(session_ident,
1085 					    "break", 0);
1086 					packet_put_int(1000);
1087 					packet_send();
1088 				}
1089 				continue;
1090 
1091 			case 'R':
1092 				if (compat20) {
1093 					if (datafellows & SSH_BUG_NOREKEY)
1094 						logit("Server does not "
1095 						    "support re-keying");
1096 					else
1097 						need_rekeying = 1;
1098 				}
1099 				continue;
1100 
1101 			case '&':
1102 				if (c && c->ctl_chan != -1)
1103 					goto noescape;
1104 				/*
1105 				 * Detach the program (continue to serve
1106 				 * connections, but put in background and no
1107 				 * more new connections).
1108 				 */
1109 				/* Restore tty modes. */
1110 				leave_raw_mode(
1111 				    options.request_tty == REQUEST_TTY_FORCE);
1112 
1113 				/* Stop listening for new connections. */
1114 				channel_stop_listening();
1115 
1116 				snprintf(string, sizeof string,
1117 				    "%c& [backgrounded]\n", escape_char);
1118 				buffer_append(berr, string, strlen(string));
1119 
1120 				/* Fork into background. */
1121 				pid = fork();
1122 				if (pid < 0) {
1123 					error("fork: %.100s", strerror(errno));
1124 					continue;
1125 				}
1126 				if (pid != 0) {	/* This is the parent. */
1127 					/* The parent just exits. */
1128 					exit(0);
1129 				}
1130 				/* The child continues serving connections. */
1131 				if (compat20) {
1132 					buffer_append(bin, "\004", 1);
1133 					/* fake EOF on stdin */
1134 					return -1;
1135 				} else if (!stdin_eof) {
1136 					/*
1137 					 * Sending SSH_CMSG_EOF alone does not
1138 					 * always appear to be enough.  So we
1139 					 * try to send an EOF character first.
1140 					 */
1141 					packet_start(SSH_CMSG_STDIN_DATA);
1142 					packet_put_string("\004", 1);
1143 					packet_send();
1144 					/* Close stdin. */
1145 					stdin_eof = 1;
1146 					if (buffer_len(bin) == 0) {
1147 						packet_start(SSH_CMSG_EOF);
1148 						packet_send();
1149 					}
1150 				}
1151 				continue;
1152 
1153 			case '?':
1154 				if (c && c->ctl_chan != -1) {
1155 					snprintf(string, sizeof string,
1156 "%c?\r\n\
1157 Supported escape sequences:\r\n\
1158   %c.  - terminate session\r\n\
1159   %cB  - send a BREAK to the remote system\r\n\
1160   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1161   %c#  - list forwarded connections\r\n\
1162   %c?  - this message\r\n\
1163   %c%c  - send the escape character by typing it twice\r\n\
1164 (Note that escapes are only recognized immediately after newline.)\r\n",
1165 					    escape_char, escape_char,
1166 					    escape_char, escape_char,
1167 					    escape_char, escape_char,
1168 					    escape_char, escape_char);
1169 				} else {
1170 					snprintf(string, sizeof string,
1171 "%c?\r\n\
1172 Supported escape sequences:\r\n\
1173   %c.  - terminate connection (and any multiplexed sessions)\r\n\
1174   %cB  - send a BREAK to the remote system\r\n\
1175   %cC  - open a command line\r\n\
1176   %cR  - Request rekey (SSH protocol 2 only)\r\n\
1177   %c^Z - suspend ssh\r\n\
1178   %c#  - list forwarded connections\r\n\
1179   %c&  - background ssh (when waiting for connections to terminate)\r\n\
1180   %c?  - this message\r\n\
1181   %c%c  - send the escape character by typing it twice\r\n\
1182 (Note that escapes are only recognized immediately after newline.)\r\n",
1183 					    escape_char, escape_char,
1184 					    escape_char, escape_char,
1185 					    escape_char, escape_char,
1186 					    escape_char, escape_char,
1187 					    escape_char, escape_char,
1188 					    escape_char);
1189 				}
1190 				buffer_append(berr, string, strlen(string));
1191 				continue;
1192 
1193 			case '#':
1194 				snprintf(string, sizeof string, "%c#\r\n",
1195 				    escape_char);
1196 				buffer_append(berr, string, strlen(string));
1197 				s = channel_open_message();
1198 				buffer_append(berr, s, strlen(s));
1199 				xfree(s);
1200 				continue;
1201 
1202 			case 'C':
1203 				if (c && c->ctl_chan != -1)
1204 					goto noescape;
1205 				process_cmdline();
1206 				continue;
1207 
1208 			default:
1209 				if (ch != escape_char) {
1210 					buffer_put_char(bin, escape_char);
1211 					bytes++;
1212 				}
1213 				/* Escaped characters fall through here */
1214 				break;
1215 			}
1216 		} else {
1217 			/*
1218 			 * The previous character was not an escape char.
1219 			 * Check if this is an escape.
1220 			 */
1221 			if (last_was_cr && ch == escape_char) {
1222 				/*
1223 				 * It is. Set the flag and continue to
1224 				 * next character.
1225 				 */
1226 				*escape_pendingp = 1;
1227 				continue;
1228 			}
1229 		}
1230 
1231 		/*
1232 		 * Normal character.  Record whether it was a newline,
1233 		 * and append it to the buffer.
1234 		 */
1235 		last_was_cr = (ch == '\r' || ch == '\n');
1236 		buffer_put_char(bin, ch);
1237 		bytes++;
1238 	}
1239 	return bytes;
1240 }
1241 
1242 static void
1243 client_process_input(fd_set *readset)
1244 {
1245 	int len;
1246 	char buf[SSH_IOBUFSZ];
1247 
1248 	/* Read input from stdin. */
1249 	if (FD_ISSET(fileno(stdin), readset)) {
1250 		/* Read as much as possible. */
1251 		len = read(fileno(stdin), buf, sizeof(buf));
1252 		if (len < 0 &&
1253 		    (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
1254 			return;		/* we'll try again later */
1255 		if (len <= 0) {
1256 			/*
1257 			 * Received EOF or error.  They are treated
1258 			 * similarly, except that an error message is printed
1259 			 * if it was an error condition.
1260 			 */
1261 			if (len < 0) {
1262 				snprintf(buf, sizeof buf, "read: %.100s\r\n",
1263 				    strerror(errno));
1264 				buffer_append(&stderr_buffer, buf, strlen(buf));
1265 			}
1266 			/* Mark that we have seen EOF. */
1267 			stdin_eof = 1;
1268 			/*
1269 			 * Send an EOF message to the server unless there is
1270 			 * data in the buffer.  If there is data in the
1271 			 * buffer, no message will be sent now.  Code
1272 			 * elsewhere will send the EOF when the buffer
1273 			 * becomes empty if stdin_eof is set.
1274 			 */
1275 			if (buffer_len(&stdin_buffer) == 0) {
1276 				packet_start(SSH_CMSG_EOF);
1277 				packet_send();
1278 			}
1279 		} else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
1280 			/*
1281 			 * Normal successful read, and no escape character.
1282 			 * Just append the data to buffer.
1283 			 */
1284 			buffer_append(&stdin_buffer, buf, len);
1285 		} else {
1286 			/*
1287 			 * Normal, successful read.  But we have an escape
1288 			 * character and have to process the characters one
1289 			 * by one.
1290 			 */
1291 			if (process_escapes(NULL, &stdin_buffer,
1292 			    &stdout_buffer, &stderr_buffer, buf, len) == -1)
1293 				return;
1294 		}
1295 	}
1296 }
1297 
1298 static void
1299 client_process_output(fd_set *writeset)
1300 {
1301 	int len;
1302 	char buf[100];
1303 
1304 	/* Write buffered output to stdout. */
1305 	if (FD_ISSET(fileno(stdout), writeset)) {
1306 		/* Write as much data as possible. */
1307 		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1308 		    buffer_len(&stdout_buffer));
1309 		if (len <= 0) {
1310 			if (errno == EINTR || errno == EAGAIN ||
1311 			    errno == EWOULDBLOCK)
1312 				len = 0;
1313 			else {
1314 				/*
1315 				 * An error or EOF was encountered.  Put an
1316 				 * error message to stderr buffer.
1317 				 */
1318 				snprintf(buf, sizeof buf,
1319 				    "write stdout: %.50s\r\n", strerror(errno));
1320 				buffer_append(&stderr_buffer, buf, strlen(buf));
1321 				quit_pending = 1;
1322 				return;
1323 			}
1324 		}
1325 		/* Consume printed data from the buffer. */
1326 		buffer_consume(&stdout_buffer, len);
1327 	}
1328 	/* Write buffered output to stderr. */
1329 	if (FD_ISSET(fileno(stderr), writeset)) {
1330 		/* Write as much data as possible. */
1331 		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1332 		    buffer_len(&stderr_buffer));
1333 		if (len <= 0) {
1334 			if (errno == EINTR || errno == EAGAIN ||
1335 			    errno == EWOULDBLOCK)
1336 				len = 0;
1337 			else {
1338 				/*
1339 				 * EOF or error, but can't even print
1340 				 * error message.
1341 				 */
1342 				quit_pending = 1;
1343 				return;
1344 			}
1345 		}
1346 		/* Consume printed characters from the buffer. */
1347 		buffer_consume(&stderr_buffer, len);
1348 	}
1349 }
1350 
1351 /*
1352  * Get packets from the connection input buffer, and process them as long as
1353  * there are packets available.
1354  *
1355  * Any unknown packets received during the actual
1356  * session cause the session to terminate.  This is
1357  * intended to make debugging easier since no
1358  * confirmations are sent.  Any compatible protocol
1359  * extensions must be negotiated during the
1360  * preparatory phase.
1361  */
1362 
1363 static void
1364 client_process_buffered_input_packets(void)
1365 {
1366 	dispatch_run(DISPATCH_NONBLOCK, &quit_pending,
1367 	    compat20 ? xxx_kex : NULL);
1368 }
1369 
1370 /* scan buf[] for '~' before sending data to the peer */
1371 
1372 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1373 void *
1374 client_new_escape_filter_ctx(int escape_char)
1375 {
1376 	struct escape_filter_ctx *ret;
1377 
1378 	ret = xmalloc(sizeof(*ret));
1379 	ret->escape_pending = 0;
1380 	ret->escape_char = escape_char;
1381 	return (void *)ret;
1382 }
1383 
1384 /* Free the escape filter context on channel free */
1385 void
1386 client_filter_cleanup(int cid, void *ctx)
1387 {
1388 	xfree(ctx);
1389 }
1390 
1391 int
1392 client_simple_escape_filter(Channel *c, char *buf, int len)
1393 {
1394 	if (c->extended_usage != CHAN_EXTENDED_WRITE)
1395 		return 0;
1396 
1397 	return process_escapes(c, &c->input, &c->output, &c->extended,
1398 	    buf, len);
1399 }
1400 
1401 static void
1402 client_channel_closed(int id, void *arg)
1403 {
1404 	channel_cancel_cleanup(id);
1405 	session_closed = 1;
1406 	leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1407 }
1408 
1409 /*
1410  * Implements the interactive session with the server.  This is called after
1411  * the user has been authenticated, and a command has been started on the
1412  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1413  * used as an escape character for terminating or suspending the session.
1414  */
1415 
1416 int
1417 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
1418 {
1419 	fd_set *readset = NULL, *writeset = NULL;
1420 	double start_time, total_time;
1421 	int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
1422 	u_int64_t ibytes, obytes;
1423 	u_int nalloc = 0;
1424 	char buf[100];
1425 
1426 	debug("Entering interactive session.");
1427 
1428 	start_time = get_current_time();
1429 
1430 	/* Initialize variables. */
1431 	escape_pending1 = 0;
1432 	last_was_cr = 1;
1433 	exit_status = -1;
1434 	stdin_eof = 0;
1435 	buffer_high = 64 * 1024;
1436 	connection_in = packet_get_connection_in();
1437 	connection_out = packet_get_connection_out();
1438 	max_fd = MAX(connection_in, connection_out);
1439 
1440 	if (!compat20) {
1441 		/* enable nonblocking unless tty */
1442 		if (!isatty(fileno(stdin)))
1443 			set_nonblock(fileno(stdin));
1444 		if (!isatty(fileno(stdout)))
1445 			set_nonblock(fileno(stdout));
1446 		if (!isatty(fileno(stderr)))
1447 			set_nonblock(fileno(stderr));
1448 		max_fd = MAX(max_fd, fileno(stdin));
1449 		max_fd = MAX(max_fd, fileno(stdout));
1450 		max_fd = MAX(max_fd, fileno(stderr));
1451 	}
1452 	quit_pending = 0;
1453 	escape_char1 = escape_char_arg;
1454 
1455 	/* Initialize buffers. */
1456 	buffer_init(&stdin_buffer);
1457 	buffer_init(&stdout_buffer);
1458 	buffer_init(&stderr_buffer);
1459 
1460 	client_init_dispatch();
1461 
1462 	/*
1463 	 * Set signal handlers, (e.g. to restore non-blocking mode)
1464 	 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1465 	 */
1466 	if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
1467 		signal(SIGHUP, signal_handler);
1468 	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
1469 		signal(SIGINT, signal_handler);
1470 	if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1471 		signal(SIGQUIT, signal_handler);
1472 	if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
1473 		signal(SIGTERM, signal_handler);
1474 	signal(SIGWINCH, window_change_handler);
1475 
1476 	if (have_pty)
1477 		enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1478 
1479 	if (compat20) {
1480 		session_ident = ssh2_chan_id;
1481 		if (session_ident != -1) {
1482 			if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1483 				channel_register_filter(session_ident,
1484 				    client_simple_escape_filter, NULL,
1485 				    client_filter_cleanup,
1486 				    client_new_escape_filter_ctx(
1487 				    escape_char_arg));
1488 			}
1489 			channel_register_cleanup(session_ident,
1490 			    client_channel_closed, 0);
1491 		}
1492 	} else {
1493 		/* Check if we should immediately send eof on stdin. */
1494 		client_check_initial_eof_on_stdin();
1495 	}
1496 
1497 	/* Main loop of the client for the interactive session mode. */
1498 	while (!quit_pending) {
1499 
1500 		/* Process buffered packets sent by the server. */
1501 		client_process_buffered_input_packets();
1502 
1503 		if (compat20 && session_closed && !channel_still_open())
1504 			break;
1505 
1506 		rekeying = (xxx_kex != NULL && !xxx_kex->done);
1507 
1508 		if (rekeying) {
1509 			debug("rekeying in progress");
1510 		} else {
1511 			/*
1512 			 * Make packets of buffered stdin data, and buffer
1513 			 * them for sending to the server.
1514 			 */
1515 			if (!compat20)
1516 				client_make_packets_from_stdin_data();
1517 
1518 			/*
1519 			 * Make packets from buffered channel data, and
1520 			 * enqueue them for sending to the server.
1521 			 */
1522 			if (packet_not_very_much_data_to_write())
1523 				channel_output_poll();
1524 
1525 			/*
1526 			 * Check if the window size has changed, and buffer a
1527 			 * message about it to the server if so.
1528 			 */
1529 			client_check_window_change();
1530 
1531 			if (quit_pending)
1532 				break;
1533 		}
1534 		/*
1535 		 * Wait until we have something to do (something becomes
1536 		 * available on one of the descriptors).
1537 		 */
1538 		max_fd2 = max_fd;
1539 		client_wait_until_can_do_something(&readset, &writeset,
1540 		    &max_fd2, &nalloc, rekeying);
1541 
1542 		if (quit_pending)
1543 			break;
1544 
1545 		/* Do channel operations unless rekeying in progress. */
1546 		if (!rekeying) {
1547 			channel_after_select(readset, writeset);
1548 			if (need_rekeying || packet_need_rekeying()) {
1549 				debug("need rekeying");
1550 				xxx_kex->done = 0;
1551 				kex_send_kexinit(xxx_kex);
1552 				need_rekeying = 0;
1553 			}
1554 		}
1555 
1556 		/* Buffer input from the connection.  */
1557 		client_process_net_input(readset);
1558 
1559 		if (quit_pending)
1560 			break;
1561 
1562 		if (!compat20) {
1563 			/* Buffer data from stdin */
1564 			client_process_input(readset);
1565 			/*
1566 			 * Process output to stdout and stderr.  Output to
1567 			 * the connection is processed elsewhere (above).
1568 			 */
1569 			client_process_output(writeset);
1570 		}
1571 
1572 		if (session_resumed) {
1573 			connection_in = packet_get_connection_in();
1574 			connection_out = packet_get_connection_out();
1575 			max_fd = MAX(max_fd, connection_out);
1576 			max_fd = MAX(max_fd, connection_in);
1577 			session_resumed = 0;
1578 		}
1579 
1580 		/*
1581 		 * Send as much buffered packet data as possible to the
1582 		 * sender.
1583 		 */
1584 		if (FD_ISSET(connection_out, writeset))
1585 			packet_write_poll();
1586 
1587 		/*
1588 		 * If we are a backgrounded control master, and the
1589 		 * timeout has expired without any active client
1590 		 * connections, then quit.
1591 		 */
1592 		if (control_persist_exit_time > 0) {
1593 			if (time(NULL) >= control_persist_exit_time) {
1594 				debug("ControlPersist timeout expired");
1595 				break;
1596 			}
1597 		}
1598 	}
1599 	if (readset)
1600 		xfree(readset);
1601 	if (writeset)
1602 		xfree(writeset);
1603 
1604 	/* Terminate the session. */
1605 
1606 	/* Stop watching for window change. */
1607 	signal(SIGWINCH, SIG_DFL);
1608 
1609 	if (compat20) {
1610 		packet_start(SSH2_MSG_DISCONNECT);
1611 		packet_put_int(SSH2_DISCONNECT_BY_APPLICATION);
1612 		packet_put_cstring("disconnected by user");
1613 		packet_put_cstring(""); /* language tag */
1614 		packet_send();
1615 		packet_write_wait();
1616 	}
1617 
1618 	channel_free_all();
1619 
1620 	if (have_pty)
1621 		leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1622 
1623 	/* restore blocking io */
1624 	if (!isatty(fileno(stdin)))
1625 		unset_nonblock(fileno(stdin));
1626 	if (!isatty(fileno(stdout)))
1627 		unset_nonblock(fileno(stdout));
1628 	if (!isatty(fileno(stderr)))
1629 		unset_nonblock(fileno(stderr));
1630 
1631 	/*
1632 	 * If there was no shell or command requested, there will be no remote
1633 	 * exit status to be returned.  In that case, clear error code if the
1634 	 * connection was deliberately terminated at this end.
1635 	 */
1636 	if (no_shell_flag && received_signal == SIGTERM) {
1637 		received_signal = 0;
1638 		exit_status = 0;
1639 	}
1640 
1641 	if (received_signal)
1642 		fatal("Killed by signal %d.", (int) received_signal);
1643 
1644 	/*
1645 	 * In interactive mode (with pseudo tty) display a message indicating
1646 	 * that the connection has been closed.
1647 	 */
1648 	if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1649 		snprintf(buf, sizeof buf,
1650 		    "Connection to %.64s closed.\r\n", host);
1651 		buffer_append(&stderr_buffer, buf, strlen(buf));
1652 	}
1653 
1654 	/* Output any buffered data for stdout. */
1655 	if (buffer_len(&stdout_buffer) > 0) {
1656 		len = atomicio(vwrite, fileno(stdout),
1657 		    buffer_ptr(&stdout_buffer), buffer_len(&stdout_buffer));
1658 		if (len < 0 || (u_int)len != buffer_len(&stdout_buffer))
1659 			error("Write failed flushing stdout buffer.");
1660 		else
1661 			buffer_consume(&stdout_buffer, len);
1662 	}
1663 
1664 	/* Output any buffered data for stderr. */
1665 	if (buffer_len(&stderr_buffer) > 0) {
1666 		len = atomicio(vwrite, fileno(stderr),
1667 		    buffer_ptr(&stderr_buffer), buffer_len(&stderr_buffer));
1668 		if (len < 0 || (u_int)len != buffer_len(&stderr_buffer))
1669 			error("Write failed flushing stderr buffer.");
1670 		else
1671 			buffer_consume(&stderr_buffer, len);
1672 	}
1673 
1674 	/* Clear and free any buffers. */
1675 	memset(buf, 0, sizeof(buf));
1676 	buffer_free(&stdin_buffer);
1677 	buffer_free(&stdout_buffer);
1678 	buffer_free(&stderr_buffer);
1679 
1680 	/* Report bytes transferred, and transfer rates. */
1681 	total_time = get_current_time() - start_time;
1682 	packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
1683 	packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1684 	verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1685 	    (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1686 	if (total_time > 0)
1687 		verbose("Bytes per second: sent %.1f, received %.1f",
1688 		    obytes / total_time, ibytes / total_time);
1689 	/* Return the exit status of the program. */
1690 	debug("Exit status %d", exit_status);
1691 	return exit_status;
1692 }
1693 
1694 /*********/
1695 
1696 static void
1697 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1698 {
1699 	u_int data_len;
1700 	char *data = packet_get_string(&data_len);
1701 	packet_check_eom();
1702 	buffer_append(&stdout_buffer, data, data_len);
1703 	memset(data, 0, data_len);
1704 	xfree(data);
1705 }
1706 static void
1707 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1708 {
1709 	u_int data_len;
1710 	char *data = packet_get_string(&data_len);
1711 	packet_check_eom();
1712 	buffer_append(&stderr_buffer, data, data_len);
1713 	memset(data, 0, data_len);
1714 	xfree(data);
1715 }
1716 static void
1717 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1718 {
1719 	exit_status = packet_get_int();
1720 	packet_check_eom();
1721 	/* Acknowledge the exit. */
1722 	packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1723 	packet_send();
1724 	/*
1725 	 * Must wait for packet to be sent since we are
1726 	 * exiting the loop.
1727 	 */
1728 	packet_write_wait();
1729 	/* Flag that we want to exit. */
1730 	quit_pending = 1;
1731 }
1732 static void
1733 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1734 {
1735 	Channel *c = NULL;
1736 	int remote_id, sock;
1737 
1738 	/* Read the remote channel number from the message. */
1739 	remote_id = packet_get_int();
1740 	packet_check_eom();
1741 
1742 	/*
1743 	 * Get a connection to the local authentication agent (this may again
1744 	 * get forwarded).
1745 	 */
1746 	sock = ssh_get_authentication_socket();
1747 
1748 	/*
1749 	 * If we could not connect the agent, send an error message back to
1750 	 * the server. This should never happen unless the agent dies,
1751 	 * because authentication forwarding is only enabled if we have an
1752 	 * agent.
1753 	 */
1754 	if (sock >= 0) {
1755 		c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1756 		    -1, 0, 0, 0, "authentication agent connection", 1);
1757 		c->remote_id = remote_id;
1758 		c->force_drain = 1;
1759 	}
1760 	if (c == NULL) {
1761 		packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1762 		packet_put_int(remote_id);
1763 	} else {
1764 		/* Send a confirmation to the remote host. */
1765 		debug("Forwarding authentication connection.");
1766 		packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1767 		packet_put_int(remote_id);
1768 		packet_put_int(c->self);
1769 	}
1770 	packet_send();
1771 }
1772 
1773 static Channel *
1774 client_request_forwarded_tcpip(const char *request_type, int rchan)
1775 {
1776 	Channel *c = NULL;
1777 	char *listen_address, *originator_address;
1778 	u_short listen_port, originator_port;
1779 
1780 	/* Get rest of the packet */
1781 	listen_address = packet_get_string(NULL);
1782 	listen_port = packet_get_int();
1783 	originator_address = packet_get_string(NULL);
1784 	originator_port = packet_get_int();
1785 	packet_check_eom();
1786 
1787 	debug("client_request_forwarded_tcpip: listen %s port %d, "
1788 	    "originator %s port %d", listen_address, listen_port,
1789 	    originator_address, originator_port);
1790 
1791 	c = channel_connect_by_listen_address(listen_port,
1792 	    "forwarded-tcpip", originator_address);
1793 
1794 	xfree(originator_address);
1795 	xfree(listen_address);
1796 	return c;
1797 }
1798 
1799 static Channel *
1800 client_request_x11(const char *request_type, int rchan)
1801 {
1802 	Channel *c = NULL;
1803 	char *originator;
1804 	u_short originator_port;
1805 	int sock;
1806 
1807 	if (!options.forward_x11) {
1808 		error("Warning: ssh server tried X11 forwarding.");
1809 		error("Warning: this is probably a break-in attempt by a "
1810 		    "malicious server.");
1811 		return NULL;
1812 	}
1813 	if (x11_refuse_time != 0 && time(NULL) >= x11_refuse_time) {
1814 		verbose("Rejected X11 connection after ForwardX11Timeout "
1815 		    "expired");
1816 		return NULL;
1817 	}
1818 	originator = packet_get_string(NULL);
1819 	if (datafellows & SSH_BUG_X11FWD) {
1820 		debug2("buggy server: x11 request w/o originator_port");
1821 		originator_port = 0;
1822 	} else {
1823 		originator_port = packet_get_int();
1824 	}
1825 	packet_check_eom();
1826 	/* XXX check permission */
1827 	debug("client_request_x11: request from %s %d", originator,
1828 	    originator_port);
1829 	xfree(originator);
1830 	sock = x11_connect_display();
1831 	if (sock < 0)
1832 		return NULL;
1833 	if (options.hpn_disabled)
1834 		c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1835 		    CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1836 		    0, "x11", 1);
1837 	else
1838 		c = channel_new("x11", SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1839 		    options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
1840 		    0, "x11", 1);
1841 	c->force_drain = 1;
1842 	return c;
1843 }
1844 
1845 static Channel *
1846 client_request_agent(const char *request_type, int rchan)
1847 {
1848 	Channel *c = NULL;
1849 	int sock;
1850 
1851 	if (!options.forward_agent) {
1852 		error("Warning: ssh server tried agent forwarding.");
1853 		error("Warning: this is probably a break-in attempt by a "
1854 		    "malicious server.");
1855 		return NULL;
1856 	}
1857 	sock = ssh_get_authentication_socket();
1858 	if (sock < 0)
1859 		return NULL;
1860 	if (options.hpn_disabled)
1861 		c = channel_new("authentication agent connection",
1862 		    SSH_CHANNEL_OPEN, sock, sock, -1,
1863 		    CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1864 		    "authentication agent connection", 1);
1865 	else
1866 		c = channel_new("authentication agent connection",
1867 		    SSH_CHANNEL_OPEN, sock, sock, -1,
1868 		    options.hpn_buffer_size, options.hpn_buffer_size, 0,
1869 		    "authentication agent connection", 1);
1870 	c->force_drain = 1;
1871 	return c;
1872 }
1873 
1874 int
1875 client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
1876 {
1877 	Channel *c;
1878 	int fd;
1879 
1880 	if (tun_mode == SSH_TUNMODE_NO)
1881 		return 0;
1882 
1883 	if (!compat20) {
1884 		error("Tunnel forwarding is not supported for protocol 1");
1885 		return -1;
1886 	}
1887 
1888 	debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1889 
1890 	/* Open local tunnel device */
1891 	if ((fd = tun_open(local_tun, tun_mode)) == -1) {
1892 		error("Tunnel device open failed.");
1893 		return -1;
1894 	}
1895 
1896 	if (options.hpn_disabled)
1897 		c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1898 		    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1899 		    0, "tun", 1);
1900 	else
1901 		c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1902 		    options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
1903 		    0, "tun", 1);
1904 	c->datagram = 1;
1905 
1906 #if defined(SSH_TUN_FILTER)
1907 	if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1908 		channel_register_filter(c->self, sys_tun_infilter,
1909 		    sys_tun_outfilter, NULL, NULL);
1910 #endif
1911 
1912 	packet_start(SSH2_MSG_CHANNEL_OPEN);
1913 	packet_put_cstring("tun@openssh.com");
1914 	packet_put_int(c->self);
1915 	packet_put_int(c->local_window_max);
1916 	packet_put_int(c->local_maxpacket);
1917 	packet_put_int(tun_mode);
1918 	packet_put_int(remote_tun);
1919 	packet_send();
1920 
1921 	return 0;
1922 }
1923 
1924 /* XXXX move to generic input handler */
1925 static void
1926 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1927 {
1928 	Channel *c = NULL;
1929 	char *ctype;
1930 	int rchan;
1931 	u_int rmaxpack, rwindow, len;
1932 
1933 	ctype = packet_get_string(&len);
1934 	rchan = packet_get_int();
1935 	rwindow = packet_get_int();
1936 	rmaxpack = packet_get_int();
1937 
1938 	debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1939 	    ctype, rchan, rwindow, rmaxpack);
1940 
1941 	if (strcmp(ctype, "forwarded-tcpip") == 0) {
1942 		c = client_request_forwarded_tcpip(ctype, rchan);
1943 	} else if (strcmp(ctype, "x11") == 0) {
1944 		c = client_request_x11(ctype, rchan);
1945 	} else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1946 		c = client_request_agent(ctype, rchan);
1947 	}
1948 /* XXX duplicate : */
1949 	if (c != NULL) {
1950 		debug("confirm %s", ctype);
1951 		c->remote_id = rchan;
1952 		c->remote_window = rwindow;
1953 		c->remote_maxpacket = rmaxpack;
1954 		if (c->type != SSH_CHANNEL_CONNECTING) {
1955 			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1956 			packet_put_int(c->remote_id);
1957 			packet_put_int(c->self);
1958 			packet_put_int(c->local_window);
1959 			packet_put_int(c->local_maxpacket);
1960 			packet_send();
1961 		}
1962 	} else {
1963 		debug("failure %s", ctype);
1964 		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1965 		packet_put_int(rchan);
1966 		packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1967 		if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1968 			packet_put_cstring("open failed");
1969 			packet_put_cstring("");
1970 		}
1971 		packet_send();
1972 	}
1973 	xfree(ctype);
1974 }
1975 static void
1976 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1977 {
1978 	Channel *c = NULL;
1979 	int exitval, id, reply, success = 0;
1980 	char *rtype;
1981 
1982 	id = packet_get_int();
1983 	rtype = packet_get_string(NULL);
1984 	reply = packet_get_char();
1985 
1986 	debug("client_input_channel_req: channel %d rtype %s reply %d",
1987 	    id, rtype, reply);
1988 
1989 	if (id == -1) {
1990 		error("client_input_channel_req: request for channel -1");
1991 	} else if ((c = channel_lookup(id)) == NULL) {
1992 		error("client_input_channel_req: channel %d: "
1993 		    "unknown channel", id);
1994 	} else if (strcmp(rtype, "eow@openssh.com") == 0) {
1995 		packet_check_eom();
1996 		chan_rcvd_eow(c);
1997 	} else if (strcmp(rtype, "exit-status") == 0) {
1998 		exitval = packet_get_int();
1999 		if (c->ctl_chan != -1) {
2000 			mux_exit_message(c, exitval);
2001 			success = 1;
2002 		} else if (id == session_ident) {
2003 			/* Record exit value of local session */
2004 			success = 1;
2005 			exit_status = exitval;
2006 		} else {
2007 			/* Probably for a mux channel that has already closed */
2008 			debug("%s: no sink for exit-status on channel %d",
2009 			    __func__, id);
2010 		}
2011 		packet_check_eom();
2012 	}
2013 	if (reply && c != NULL) {
2014 		packet_start(success ?
2015 		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
2016 		packet_put_int(c->remote_id);
2017 		packet_send();
2018 	}
2019 	xfree(rtype);
2020 }
2021 static void
2022 client_input_global_request(int type, u_int32_t seq, void *ctxt)
2023 {
2024 	char *rtype;
2025 	int want_reply;
2026 	int success = 0;
2027 
2028 	rtype = packet_get_string(NULL);
2029 	want_reply = packet_get_char();
2030 	debug("client_input_global_request: rtype %s want_reply %d",
2031 	    rtype, want_reply);
2032 	if (want_reply) {
2033 		packet_start(success ?
2034 		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
2035 		packet_send();
2036 		packet_write_wait();
2037 	}
2038 	xfree(rtype);
2039 }
2040 
2041 void
2042 client_session2_setup(int id, int want_tty, int want_subsystem,
2043     const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env)
2044 {
2045 	int len;
2046 	Channel *c = NULL;
2047 
2048 	debug2("%s: id %d", __func__, id);
2049 
2050 	if ((c = channel_lookup(id)) == NULL)
2051 		fatal("client_session2_setup: channel %d: unknown channel", id);
2052 
2053 	packet_set_interactive(want_tty,
2054 	    options.ip_qos_interactive, options.ip_qos_bulk);
2055 
2056 	if (want_tty) {
2057 		struct winsize ws;
2058 
2059 		/* Store window size in the packet. */
2060 		if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
2061 			memset(&ws, 0, sizeof(ws));
2062 
2063 		channel_request_start(id, "pty-req", 1);
2064 		client_expect_confirm(id, "PTY allocation", CONFIRM_TTY);
2065 		packet_put_cstring(term != NULL ? term : "");
2066 		packet_put_int((u_int)ws.ws_col);
2067 		packet_put_int((u_int)ws.ws_row);
2068 		packet_put_int((u_int)ws.ws_xpixel);
2069 		packet_put_int((u_int)ws.ws_ypixel);
2070 		if (tiop == NULL)
2071 			tiop = get_saved_tio();
2072 		tty_make_modes(-1, tiop);
2073 		packet_send();
2074 		/* XXX wait for reply */
2075 		c->client_tty = 1;
2076 	}
2077 
2078 	/* Transfer any environment variables from client to server */
2079 	if (options.num_send_env != 0 && env != NULL) {
2080 		int i, j, matched;
2081 		char *name, *val;
2082 
2083 		debug("Sending environment.");
2084 		for (i = 0; env[i] != NULL; i++) {
2085 			/* Split */
2086 			name = xstrdup(env[i]);
2087 			if ((val = strchr(name, '=')) == NULL) {
2088 				xfree(name);
2089 				continue;
2090 			}
2091 			*val++ = '\0';
2092 
2093 			matched = 0;
2094 			for (j = 0; j < options.num_send_env; j++) {
2095 				if (match_pattern(name, options.send_env[j])) {
2096 					matched = 1;
2097 					break;
2098 				}
2099 			}
2100 			if (!matched) {
2101 				debug3("Ignored env %s", name);
2102 				xfree(name);
2103 				continue;
2104 			}
2105 
2106 			debug("Sending env %s = %s", name, val);
2107 			channel_request_start(id, "env", 0);
2108 			packet_put_cstring(name);
2109 			packet_put_cstring(val);
2110 			packet_send();
2111 			xfree(name);
2112 		}
2113 	}
2114 
2115 	len = buffer_len(cmd);
2116 	if (len > 0) {
2117 		if (len > 900)
2118 			len = 900;
2119 		if (want_subsystem) {
2120 			debug("Sending subsystem: %.*s",
2121 			    len, (u_char*)buffer_ptr(cmd));
2122 			channel_request_start(id, "subsystem", 1);
2123 			client_expect_confirm(id, "subsystem", CONFIRM_CLOSE);
2124 		} else {
2125 			debug("Sending command: %.*s",
2126 			    len, (u_char*)buffer_ptr(cmd));
2127 			channel_request_start(id, "exec", 1);
2128 			client_expect_confirm(id, "exec", CONFIRM_CLOSE);
2129 		}
2130 		packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
2131 		packet_send();
2132 	} else {
2133 		channel_request_start(id, "shell", 1);
2134 		client_expect_confirm(id, "shell", CONFIRM_CLOSE);
2135 		packet_send();
2136 	}
2137 }
2138 
2139 static void
2140 client_init_dispatch_20(void)
2141 {
2142 	dispatch_init(&dispatch_protocol_error);
2143 
2144 	dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2145 	dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2146 	dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2147 	dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2148 	dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2149 	dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2150 	dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2151 	dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2152 	dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2153 	dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2154 	dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2155 	dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2156 
2157 	/* rekeying */
2158 	dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
2159 
2160 	/* global request reply messages */
2161 	dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2162 	dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2163 }
2164 
2165 static void
2166 client_init_dispatch_13(void)
2167 {
2168 	dispatch_init(NULL);
2169 	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
2170 	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
2171 	dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
2172 	dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2173 	dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2174 	dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
2175 	dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
2176 	dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
2177 	dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
2178 
2179 	dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
2180 	    &client_input_agent_open : &deny_input_open);
2181 	dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
2182 	    &x11_input_open : &deny_input_open);
2183 }
2184 
2185 static void
2186 client_init_dispatch_15(void)
2187 {
2188 	client_init_dispatch_13();
2189 	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
2190 	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
2191 }
2192 
2193 static void
2194 client_init_dispatch(void)
2195 {
2196 	if (compat20)
2197 		client_init_dispatch_20();
2198 	else if (compat13)
2199 		client_init_dispatch_13();
2200 	else
2201 		client_init_dispatch_15();
2202 }
2203 
2204 void
2205 client_stop_mux(void)
2206 {
2207 	if (options.control_path != NULL && muxserver_sock != -1)
2208 		unlink(options.control_path);
2209 	/*
2210 	 * If we are in persist mode, signal that we should close when all
2211 	 * active channels are closed.
2212 	 */
2213 	if (options.control_persist) {
2214 		session_closed = 1;
2215 		setproctitle("[stopped mux]");
2216 	}
2217 }
2218 
2219 /* client specific fatal cleanup */
2220 void
2221 cleanup_exit(int i)
2222 {
2223 	leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2224 	leave_non_blocking();
2225 	if (options.control_path != NULL && muxserver_sock != -1)
2226 		unlink(options.control_path);
2227 	ssh_kill_proxy_command();
2228 	_exit(i);
2229 }
2230