xref: /openbsd-src/usr.bin/ssh/clientloop.c (revision b725ae7711052a2233e31a66fefb8a752c388d7a)
1 /*
2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4  *                    All rights reserved
5  * The main loop for the interactive session (client side).
6  *
7  * As far as I am concerned, the code I have written for this software
8  * can be used freely for any purpose.  Any derived versions of this
9  * software must be clearly marked as such, and if the derived work is
10  * incompatible with the protocol description in the RFC file, it must be
11  * called by a name other than "ssh" or "Secure Shell".
12  *
13  *
14  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  *
36  *
37  * SSH2 support added by Markus Friedl.
38  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59  */
60 
61 #include "includes.h"
62 RCSID("$OpenBSD: clientloop.c,v 1.121 2004/05/21 11:33:11 djm Exp $");
63 
64 #include "ssh.h"
65 #include "ssh1.h"
66 #include "ssh2.h"
67 #include "xmalloc.h"
68 #include "packet.h"
69 #include "buffer.h"
70 #include "compat.h"
71 #include "channels.h"
72 #include "dispatch.h"
73 #include "buffer.h"
74 #include "bufaux.h"
75 #include "key.h"
76 #include "kex.h"
77 #include "log.h"
78 #include "readconf.h"
79 #include "clientloop.h"
80 #include "authfd.h"
81 #include "atomicio.h"
82 #include "sshpty.h"
83 #include "misc.h"
84 
85 /* import options */
86 extern Options options;
87 
88 /* Flag indicating that stdin should be redirected from /dev/null. */
89 extern int stdin_null_flag;
90 
91 /* Flag indicating that no shell has been requested */
92 extern int no_shell_flag;
93 
94 /*
95  * Name of the host we are connecting to.  This is the name given on the
96  * command line, or the HostName specified for the user-supplied name in a
97  * configuration file.
98  */
99 extern char *host;
100 
101 /*
102  * Flag to indicate that we have received a window change signal which has
103  * not yet been processed.  This will cause a message indicating the new
104  * window size to be sent to the server a little later.  This is volatile
105  * because this is updated in a signal handler.
106  */
107 static volatile sig_atomic_t received_window_change_signal = 0;
108 static volatile sig_atomic_t received_signal = 0;
109 
110 /* Flag indicating whether the user\'s terminal is in non-blocking mode. */
111 static int in_non_blocking_mode = 0;
112 
113 /* Common data for the client loop code. */
114 static int quit_pending;	/* Set to non-zero to quit the client loop. */
115 static int escape_char;		/* Escape character. */
116 static int escape_pending;	/* Last character was the escape character */
117 static int last_was_cr;		/* Last character was a newline. */
118 static int exit_status;		/* Used to store the exit status of the command. */
119 static int stdin_eof;		/* EOF has been encountered on standard error. */
120 static Buffer stdin_buffer;	/* Buffer for stdin data. */
121 static Buffer stdout_buffer;	/* Buffer for stdout data. */
122 static Buffer stderr_buffer;	/* Buffer for stderr data. */
123 static u_long stdin_bytes, stdout_bytes, stderr_bytes;
124 static u_int buffer_high;/* Soft max buffer size. */
125 static int connection_in;	/* Connection to server (input). */
126 static int connection_out;	/* Connection to server (output). */
127 static int need_rekeying;	/* Set to non-zero if rekeying is requested. */
128 static int session_closed = 0;	/* In SSH2: login session closed. */
129 static int server_alive_timeouts = 0;
130 
131 static void client_init_dispatch(void);
132 int	session_ident = -1;
133 
134 /*XXX*/
135 extern Kex *xxx_kex;
136 
137 /* Restores stdin to blocking mode. */
138 
139 static void
140 leave_non_blocking(void)
141 {
142 	if (in_non_blocking_mode) {
143 		(void) fcntl(fileno(stdin), F_SETFL, 0);
144 		in_non_blocking_mode = 0;
145 	}
146 }
147 
148 /* Puts stdin terminal in non-blocking mode. */
149 
150 static void
151 enter_non_blocking(void)
152 {
153 	in_non_blocking_mode = 1;
154 	(void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
155 }
156 
157 /*
158  * Signal handler for the window change signal (SIGWINCH).  This just sets a
159  * flag indicating that the window has changed.
160  */
161 
162 static void
163 window_change_handler(int sig)
164 {
165 	received_window_change_signal = 1;
166 	signal(SIGWINCH, window_change_handler);
167 }
168 
169 /*
170  * Signal handler for signals that cause the program to terminate.  These
171  * signals must be trapped to restore terminal modes.
172  */
173 
174 static void
175 signal_handler(int sig)
176 {
177 	received_signal = sig;
178 	quit_pending = 1;
179 }
180 
181 /*
182  * Returns current time in seconds from Jan 1, 1970 with the maximum
183  * available resolution.
184  */
185 
186 static double
187 get_current_time(void)
188 {
189 	struct timeval tv;
190 	gettimeofday(&tv, NULL);
191 	return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
192 }
193 
194 /*
195  * This is called when the interactive is entered.  This checks if there is
196  * an EOF coming on stdin.  We must check this explicitly, as select() does
197  * not appear to wake up when redirecting from /dev/null.
198  */
199 
200 static void
201 client_check_initial_eof_on_stdin(void)
202 {
203 	int len;
204 	char buf[1];
205 
206 	/*
207 	 * If standard input is to be "redirected from /dev/null", we simply
208 	 * mark that we have seen an EOF and send an EOF message to the
209 	 * server. Otherwise, we try to read a single character; it appears
210 	 * that for some files, such /dev/null, select() never wakes up for
211 	 * read for this descriptor, which means that we never get EOF.  This
212 	 * way we will get the EOF if stdin comes from /dev/null or similar.
213 	 */
214 	if (stdin_null_flag) {
215 		/* Fake EOF on stdin. */
216 		debug("Sending eof.");
217 		stdin_eof = 1;
218 		packet_start(SSH_CMSG_EOF);
219 		packet_send();
220 	} else {
221 		enter_non_blocking();
222 
223 		/* Check for immediate EOF on stdin. */
224 		len = read(fileno(stdin), buf, 1);
225 		if (len == 0) {
226 			/* EOF.  Record that we have seen it and send EOF to server. */
227 			debug("Sending eof.");
228 			stdin_eof = 1;
229 			packet_start(SSH_CMSG_EOF);
230 			packet_send();
231 		} else if (len > 0) {
232 			/*
233 			 * Got data.  We must store the data in the buffer,
234 			 * and also process it as an escape character if
235 			 * appropriate.
236 			 */
237 			if ((u_char) buf[0] == escape_char)
238 				escape_pending = 1;
239 			else
240 				buffer_append(&stdin_buffer, buf, 1);
241 		}
242 		leave_non_blocking();
243 	}
244 }
245 
246 
247 /*
248  * Make packets from buffered stdin data, and buffer them for sending to the
249  * connection.
250  */
251 
252 static void
253 client_make_packets_from_stdin_data(void)
254 {
255 	u_int len;
256 
257 	/* Send buffered stdin data to the server. */
258 	while (buffer_len(&stdin_buffer) > 0 &&
259 	    packet_not_very_much_data_to_write()) {
260 		len = buffer_len(&stdin_buffer);
261 		/* Keep the packets at reasonable size. */
262 		if (len > packet_get_maxsize())
263 			len = packet_get_maxsize();
264 		packet_start(SSH_CMSG_STDIN_DATA);
265 		packet_put_string(buffer_ptr(&stdin_buffer), len);
266 		packet_send();
267 		buffer_consume(&stdin_buffer, len);
268 		stdin_bytes += len;
269 		/* If we have a pending EOF, send it now. */
270 		if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
271 			packet_start(SSH_CMSG_EOF);
272 			packet_send();
273 		}
274 	}
275 }
276 
277 /*
278  * Checks if the client window has changed, and sends a packet about it to
279  * the server if so.  The actual change is detected elsewhere (by a software
280  * interrupt on Unix); this just checks the flag and sends a message if
281  * appropriate.
282  */
283 
284 static void
285 client_check_window_change(void)
286 {
287 	struct winsize ws;
288 
289 	if (! received_window_change_signal)
290 		return;
291 	/** XXX race */
292 	received_window_change_signal = 0;
293 
294 	if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
295 		return;
296 
297 	debug2("client_check_window_change: changed");
298 
299 	if (compat20) {
300 		channel_request_start(session_ident, "window-change", 0);
301 		packet_put_int(ws.ws_col);
302 		packet_put_int(ws.ws_row);
303 		packet_put_int(ws.ws_xpixel);
304 		packet_put_int(ws.ws_ypixel);
305 		packet_send();
306 	} else {
307 		packet_start(SSH_CMSG_WINDOW_SIZE);
308 		packet_put_int(ws.ws_row);
309 		packet_put_int(ws.ws_col);
310 		packet_put_int(ws.ws_xpixel);
311 		packet_put_int(ws.ws_ypixel);
312 		packet_send();
313 	}
314 }
315 
316 static void
317 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
318 {
319 	server_alive_timeouts = 0;
320 	client_global_request_reply_fwd(type, seq, ctxt);
321 }
322 
323 static void
324 server_alive_check(void)
325 {
326 	if (++server_alive_timeouts > options.server_alive_count_max)
327 		packet_disconnect("Timeout, server not responding.");
328 	packet_start(SSH2_MSG_GLOBAL_REQUEST);
329 	packet_put_cstring("keepalive@openssh.com");
330 	packet_put_char(1);     /* boolean: want reply */
331 	packet_send();
332 }
333 
334 /*
335  * Waits until the client can do something (some data becomes available on
336  * one of the file descriptors).
337  */
338 
339 static void
340 client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
341     int *maxfdp, int *nallocp, int rekeying)
342 {
343 	struct timeval tv, *tvp;
344 	int ret;
345 
346 	/* Add any selections by the channel mechanism. */
347 	channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
348 
349 	if (!compat20) {
350 		/* Read from the connection, unless our buffers are full. */
351 		if (buffer_len(&stdout_buffer) < buffer_high &&
352 		    buffer_len(&stderr_buffer) < buffer_high &&
353 		    channel_not_very_much_buffered_data())
354 			FD_SET(connection_in, *readsetp);
355 		/*
356 		 * Read from stdin, unless we have seen EOF or have very much
357 		 * buffered data to send to the server.
358 		 */
359 		if (!stdin_eof && packet_not_very_much_data_to_write())
360 			FD_SET(fileno(stdin), *readsetp);
361 
362 		/* Select stdout/stderr if have data in buffer. */
363 		if (buffer_len(&stdout_buffer) > 0)
364 			FD_SET(fileno(stdout), *writesetp);
365 		if (buffer_len(&stderr_buffer) > 0)
366 			FD_SET(fileno(stderr), *writesetp);
367 	} else {
368 		/* channel_prepare_select could have closed the last channel */
369 		if (session_closed && !channel_still_open() &&
370 		    !packet_have_data_to_write()) {
371 			/* clear mask since we did not call select() */
372 			memset(*readsetp, 0, *nallocp);
373 			memset(*writesetp, 0, *nallocp);
374 			return;
375 		} else {
376 			FD_SET(connection_in, *readsetp);
377 		}
378 	}
379 
380 	/* Select server connection if have data to write to the server. */
381 	if (packet_have_data_to_write())
382 		FD_SET(connection_out, *writesetp);
383 
384 	/*
385 	 * Wait for something to happen.  This will suspend the process until
386 	 * some selected descriptor can be read, written, or has some other
387 	 * event pending.
388 	 */
389 
390 	if (options.server_alive_interval == 0 || !compat20)
391 		tvp = NULL;
392 	else {
393 		tv.tv_sec = options.server_alive_interval;
394 		tv.tv_usec = 0;
395 		tvp = &tv;
396 	}
397 	ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
398 	if (ret < 0) {
399 		char buf[100];
400 
401 		/*
402 		 * We have to clear the select masks, because we return.
403 		 * We have to return, because the mainloop checks for the flags
404 		 * set by the signal handlers.
405 		 */
406 		memset(*readsetp, 0, *nallocp);
407 		memset(*writesetp, 0, *nallocp);
408 
409 		if (errno == EINTR)
410 			return;
411 		/* Note: we might still have data in the buffers. */
412 		snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
413 		buffer_append(&stderr_buffer, buf, strlen(buf));
414 		quit_pending = 1;
415 	} else if (ret == 0)
416 		server_alive_check();
417 }
418 
419 static void
420 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
421 {
422 	struct winsize oldws, newws;
423 
424 	/* Flush stdout and stderr buffers. */
425 	if (buffer_len(bout) > 0)
426 		atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
427 	if (buffer_len(berr) > 0)
428 		atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
429 
430 	leave_raw_mode();
431 
432 	/*
433 	 * Free (and clear) the buffer to reduce the amount of data that gets
434 	 * written to swap.
435 	 */
436 	buffer_free(bin);
437 	buffer_free(bout);
438 	buffer_free(berr);
439 
440 	/* Save old window size. */
441 	ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
442 
443 	/* Send the suspend signal to the program itself. */
444 	kill(getpid(), SIGTSTP);
445 
446 	/* Check if the window size has changed. */
447 	if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
448 	    (oldws.ws_row != newws.ws_row ||
449 	    oldws.ws_col != newws.ws_col ||
450 	    oldws.ws_xpixel != newws.ws_xpixel ||
451 	    oldws.ws_ypixel != newws.ws_ypixel))
452 		received_window_change_signal = 1;
453 
454 	/* OK, we have been continued by the user. Reinitialize buffers. */
455 	buffer_init(bin);
456 	buffer_init(bout);
457 	buffer_init(berr);
458 
459 	enter_raw_mode();
460 }
461 
462 static void
463 client_process_net_input(fd_set * readset)
464 {
465 	int len;
466 	char buf[8192];
467 
468 	/*
469 	 * Read input from the server, and add any such data to the buffer of
470 	 * the packet subsystem.
471 	 */
472 	if (FD_ISSET(connection_in, readset)) {
473 		/* Read as much as possible. */
474 		len = read(connection_in, buf, sizeof(buf));
475 		if (len == 0) {
476 			/* Received EOF.  The remote host has closed the connection. */
477 			snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
478 				 host);
479 			buffer_append(&stderr_buffer, buf, strlen(buf));
480 			quit_pending = 1;
481 			return;
482 		}
483 		/*
484 		 * There is a kernel bug on Solaris that causes select to
485 		 * sometimes wake up even though there is no data available.
486 		 */
487 		if (len < 0 && (errno == EAGAIN || errno == EINTR))
488 			len = 0;
489 
490 		if (len < 0) {
491 			/* An error has encountered.  Perhaps there is a network problem. */
492 			snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
493 				 host, strerror(errno));
494 			buffer_append(&stderr_buffer, buf, strlen(buf));
495 			quit_pending = 1;
496 			return;
497 		}
498 		packet_process_incoming(buf, len);
499 	}
500 }
501 
502 static void
503 process_cmdline(void)
504 {
505 	void (*handler)(int);
506 	char *s, *cmd;
507 	u_short fwd_port, fwd_host_port;
508 	char buf[1024], sfwd_port[6], sfwd_host_port[6];
509 	int delete = 0;
510 	int local = 0;
511 
512 	leave_raw_mode();
513 	handler = signal(SIGINT, SIG_IGN);
514 	cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
515 	if (s == NULL)
516 		goto out;
517 	while (*s && isspace(*s))
518 		s++;
519 	if (*s == '-')
520 		s++;	/* Skip cmdline '-', if any */
521 	if (*s == '\0')
522 		goto out;
523 
524 	if (*s == '?') {
525 		logit("Commands:");
526 		logit("      -Lport:host:hostport    Request local forward");
527 		logit("      -Rport:host:hostport    Request remote forward");
528 		logit("      -KRhostport             Cancel remote forward");
529 		goto out;
530 	}
531 
532 	if (*s == 'K') {
533 		delete = 1;
534 		s++;
535 	}
536 	if (*s != 'L' && *s != 'R') {
537 		logit("Invalid command.");
538 		goto out;
539 	}
540 	if (*s == 'L')
541 		local = 1;
542 	if (local && delete) {
543 		logit("Not supported.");
544 		goto out;
545 	}
546 	if ((!local || delete) && !compat20) {
547 		logit("Not supported for SSH protocol version 1.");
548 		goto out;
549 	}
550 
551 	s++;
552 	while (*s && isspace(*s))
553 		s++;
554 
555 	if (delete) {
556 		if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
557 			logit("Bad forwarding specification.");
558 			goto out;
559 		}
560 		if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
561 			logit("Bad forwarding port(s).");
562 			goto out;
563 		}
564 		channel_request_rforward_cancel(fwd_host_port);
565 	} else {
566 		if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
567 		    sfwd_port, buf, sfwd_host_port) != 3 &&
568 		    sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
569 		    sfwd_port, buf, sfwd_host_port) != 3) {
570 			logit("Bad forwarding specification.");
571 			goto out;
572 		}
573 		if ((fwd_port = a2port(sfwd_port)) == 0 ||
574 		    (fwd_host_port = a2port(sfwd_host_port)) == 0) {
575 			logit("Bad forwarding port(s).");
576 			goto out;
577 		}
578 		if (local) {
579 			if (channel_setup_local_fwd_listener(fwd_port, buf,
580 			    fwd_host_port, options.gateway_ports) < 0) {
581 				logit("Port forwarding failed.");
582 				goto out;
583 			}
584 		} else
585 			channel_request_remote_forwarding(fwd_port, buf,
586 			    fwd_host_port);
587 		logit("Forwarding port.");
588 	}
589 
590 out:
591 	signal(SIGINT, handler);
592 	enter_raw_mode();
593 	if (cmd)
594 		xfree(cmd);
595 }
596 
597 /* process the characters one by one */
598 static int
599 process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
600 {
601 	char string[1024];
602 	pid_t pid;
603 	int bytes = 0;
604 	u_int i;
605 	u_char ch;
606 	char *s;
607 
608 	for (i = 0; i < len; i++) {
609 		/* Get one character at a time. */
610 		ch = buf[i];
611 
612 		if (escape_pending) {
613 			/* We have previously seen an escape character. */
614 			/* Clear the flag now. */
615 			escape_pending = 0;
616 
617 			/* Process the escaped character. */
618 			switch (ch) {
619 			case '.':
620 				/* Terminate the connection. */
621 				snprintf(string, sizeof string, "%c.\r\n", escape_char);
622 				buffer_append(berr, string, strlen(string));
623 
624 				quit_pending = 1;
625 				return -1;
626 
627 			case 'Z' - 64:
628 				/* Suspend the program. */
629 				/* Print a message to that effect to the user. */
630 				snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
631 				buffer_append(berr, string, strlen(string));
632 
633 				/* Restore terminal modes and suspend. */
634 				client_suspend_self(bin, bout, berr);
635 
636 				/* We have been continued. */
637 				continue;
638 
639 			case 'B':
640 				if (compat20) {
641 					snprintf(string, sizeof string,
642 					    "%cB\r\n", escape_char);
643 					buffer_append(berr, string,
644 					    strlen(string));
645 					channel_request_start(session_ident,
646 					    "break", 0);
647 					packet_put_int(1000);
648 					packet_send();
649 				}
650 				continue;
651 
652 			case 'R':
653 				if (compat20) {
654 					if (datafellows & SSH_BUG_NOREKEY)
655 						logit("Server does not support re-keying");
656 					else
657 						need_rekeying = 1;
658 				}
659 				continue;
660 
661 			case '&':
662 				/*
663 				 * Detach the program (continue to serve connections,
664 				 * but put in background and no more new connections).
665 				 */
666 				/* Restore tty modes. */
667 				leave_raw_mode();
668 
669 				/* Stop listening for new connections. */
670 				channel_stop_listening();
671 
672 				snprintf(string, sizeof string,
673 				    "%c& [backgrounded]\n", escape_char);
674 				buffer_append(berr, string, strlen(string));
675 
676 				/* Fork into background. */
677 				pid = fork();
678 				if (pid < 0) {
679 					error("fork: %.100s", strerror(errno));
680 					continue;
681 				}
682 				if (pid != 0) {	/* This is the parent. */
683 					/* The parent just exits. */
684 					exit(0);
685 				}
686 				/* The child continues serving connections. */
687 				if (compat20) {
688 					buffer_append(bin, "\004", 1);
689 					/* fake EOF on stdin */
690 					return -1;
691 				} else if (!stdin_eof) {
692 					/*
693 					 * Sending SSH_CMSG_EOF alone does not always appear
694 					 * to be enough.  So we try to send an EOF character
695 					 * first.
696 					 */
697 					packet_start(SSH_CMSG_STDIN_DATA);
698 					packet_put_string("\004", 1);
699 					packet_send();
700 					/* Close stdin. */
701 					stdin_eof = 1;
702 					if (buffer_len(bin) == 0) {
703 						packet_start(SSH_CMSG_EOF);
704 						packet_send();
705 					}
706 				}
707 				continue;
708 
709 			case '?':
710 				snprintf(string, sizeof string,
711 "%c?\r\n\
712 Supported escape sequences:\r\n\
713 %c.  - terminate connection\r\n\
714 %cB  - send a BREAK to the remote system\r\n\
715 %cC  - open a command line\r\n\
716 %cR  - Request rekey (SSH protocol 2 only)\r\n\
717 %c^Z - suspend ssh\r\n\
718 %c#  - list forwarded connections\r\n\
719 %c&  - background ssh (when waiting for connections to terminate)\r\n\
720 %c?  - this message\r\n\
721 %c%c  - send the escape character by typing it twice\r\n\
722 (Note that escapes are only recognized immediately after newline.)\r\n",
723 				    escape_char, escape_char, escape_char, escape_char,
724 				    escape_char, escape_char, escape_char, escape_char,
725 				    escape_char, escape_char, escape_char);
726 				buffer_append(berr, string, strlen(string));
727 				continue;
728 
729 			case '#':
730 				snprintf(string, sizeof string, "%c#\r\n", escape_char);
731 				buffer_append(berr, string, strlen(string));
732 				s = channel_open_message();
733 				buffer_append(berr, s, strlen(s));
734 				xfree(s);
735 				continue;
736 
737 			case 'C':
738 				process_cmdline();
739 				continue;
740 
741 			default:
742 				if (ch != escape_char) {
743 					buffer_put_char(bin, escape_char);
744 					bytes++;
745 				}
746 				/* Escaped characters fall through here */
747 				break;
748 			}
749 		} else {
750 			/*
751 			 * The previous character was not an escape char. Check if this
752 			 * is an escape.
753 			 */
754 			if (last_was_cr && ch == escape_char) {
755 				/* It is. Set the flag and continue to next character. */
756 				escape_pending = 1;
757 				continue;
758 			}
759 		}
760 
761 		/*
762 		 * Normal character.  Record whether it was a newline,
763 		 * and append it to the buffer.
764 		 */
765 		last_was_cr = (ch == '\r' || ch == '\n');
766 		buffer_put_char(bin, ch);
767 		bytes++;
768 	}
769 	return bytes;
770 }
771 
772 static void
773 client_process_input(fd_set * readset)
774 {
775 	int len;
776 	char buf[8192];
777 
778 	/* Read input from stdin. */
779 	if (FD_ISSET(fileno(stdin), readset)) {
780 		/* Read as much as possible. */
781 		len = read(fileno(stdin), buf, sizeof(buf));
782 		if (len < 0 && (errno == EAGAIN || errno == EINTR))
783 			return;		/* we'll try again later */
784 		if (len <= 0) {
785 			/*
786 			 * Received EOF or error.  They are treated
787 			 * similarly, except that an error message is printed
788 			 * if it was an error condition.
789 			 */
790 			if (len < 0) {
791 				snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
792 				buffer_append(&stderr_buffer, buf, strlen(buf));
793 			}
794 			/* Mark that we have seen EOF. */
795 			stdin_eof = 1;
796 			/*
797 			 * Send an EOF message to the server unless there is
798 			 * data in the buffer.  If there is data in the
799 			 * buffer, no message will be sent now.  Code
800 			 * elsewhere will send the EOF when the buffer
801 			 * becomes empty if stdin_eof is set.
802 			 */
803 			if (buffer_len(&stdin_buffer) == 0) {
804 				packet_start(SSH_CMSG_EOF);
805 				packet_send();
806 			}
807 		} else if (escape_char == SSH_ESCAPECHAR_NONE) {
808 			/*
809 			 * Normal successful read, and no escape character.
810 			 * Just append the data to buffer.
811 			 */
812 			buffer_append(&stdin_buffer, buf, len);
813 		} else {
814 			/*
815 			 * Normal, successful read.  But we have an escape character
816 			 * and have to process the characters one by one.
817 			 */
818 			if (process_escapes(&stdin_buffer, &stdout_buffer,
819 			    &stderr_buffer, buf, len) == -1)
820 				return;
821 		}
822 	}
823 }
824 
825 static void
826 client_process_output(fd_set * writeset)
827 {
828 	int len;
829 	char buf[100];
830 
831 	/* Write buffered output to stdout. */
832 	if (FD_ISSET(fileno(stdout), writeset)) {
833 		/* Write as much data as possible. */
834 		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
835 		    buffer_len(&stdout_buffer));
836 		if (len <= 0) {
837 			if (errno == EINTR || errno == EAGAIN)
838 				len = 0;
839 			else {
840 				/*
841 				 * An error or EOF was encountered.  Put an
842 				 * error message to stderr buffer.
843 				 */
844 				snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
845 				buffer_append(&stderr_buffer, buf, strlen(buf));
846 				quit_pending = 1;
847 				return;
848 			}
849 		}
850 		/* Consume printed data from the buffer. */
851 		buffer_consume(&stdout_buffer, len);
852 		stdout_bytes += len;
853 	}
854 	/* Write buffered output to stderr. */
855 	if (FD_ISSET(fileno(stderr), writeset)) {
856 		/* Write as much data as possible. */
857 		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
858 		    buffer_len(&stderr_buffer));
859 		if (len <= 0) {
860 			if (errno == EINTR || errno == EAGAIN)
861 				len = 0;
862 			else {
863 				/* EOF or error, but can't even print error message. */
864 				quit_pending = 1;
865 				return;
866 			}
867 		}
868 		/* Consume printed characters from the buffer. */
869 		buffer_consume(&stderr_buffer, len);
870 		stderr_bytes += len;
871 	}
872 }
873 
874 /*
875  * Get packets from the connection input buffer, and process them as long as
876  * there are packets available.
877  *
878  * Any unknown packets received during the actual
879  * session cause the session to terminate.  This is
880  * intended to make debugging easier since no
881  * confirmations are sent.  Any compatible protocol
882  * extensions must be negotiated during the
883  * preparatory phase.
884  */
885 
886 static void
887 client_process_buffered_input_packets(void)
888 {
889 	dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
890 }
891 
892 /* scan buf[] for '~' before sending data to the peer */
893 
894 static int
895 simple_escape_filter(Channel *c, char *buf, int len)
896 {
897 	/* XXX we assume c->extended is writeable */
898 	return process_escapes(&c->input, &c->output, &c->extended, buf, len);
899 }
900 
901 static void
902 client_channel_closed(int id, void *arg)
903 {
904 	if (id != session_ident)
905 		error("client_channel_closed: id %d != session_ident %d",
906 		    id, session_ident);
907 	channel_cancel_cleanup(id);
908 	session_closed = 1;
909 	leave_raw_mode();
910 }
911 
912 /*
913  * Implements the interactive session with the server.  This is called after
914  * the user has been authenticated, and a command has been started on the
915  * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
916  * used as an escape character for terminating or suspending the session.
917  */
918 
919 int
920 client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
921 {
922 	fd_set *readset = NULL, *writeset = NULL;
923 	double start_time, total_time;
924 	int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0;
925 	char buf[100];
926 
927 	debug("Entering interactive session.");
928 
929 	start_time = get_current_time();
930 
931 	/* Initialize variables. */
932 	escape_pending = 0;
933 	last_was_cr = 1;
934 	exit_status = -1;
935 	stdin_eof = 0;
936 	buffer_high = 64 * 1024;
937 	connection_in = packet_get_connection_in();
938 	connection_out = packet_get_connection_out();
939 	max_fd = MAX(connection_in, connection_out);
940 
941 	if (!compat20) {
942 		/* enable nonblocking unless tty */
943 		if (!isatty(fileno(stdin)))
944 			set_nonblock(fileno(stdin));
945 		if (!isatty(fileno(stdout)))
946 			set_nonblock(fileno(stdout));
947 		if (!isatty(fileno(stderr)))
948 			set_nonblock(fileno(stderr));
949 		max_fd = MAX(max_fd, fileno(stdin));
950 		max_fd = MAX(max_fd, fileno(stdout));
951 		max_fd = MAX(max_fd, fileno(stderr));
952 	}
953 	stdin_bytes = 0;
954 	stdout_bytes = 0;
955 	stderr_bytes = 0;
956 	quit_pending = 0;
957 	escape_char = escape_char_arg;
958 
959 	/* Initialize buffers. */
960 	buffer_init(&stdin_buffer);
961 	buffer_init(&stdout_buffer);
962 	buffer_init(&stderr_buffer);
963 
964 	client_init_dispatch();
965 
966 	/*
967 	 * Set signal handlers, (e.g. to restore non-blocking mode)
968 	 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
969 	 */
970 	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
971 		signal(SIGINT, signal_handler);
972 	if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
973 		signal(SIGQUIT, signal_handler);
974 	if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
975 		signal(SIGTERM, signal_handler);
976 	if (have_pty)
977 		signal(SIGWINCH, window_change_handler);
978 
979 	if (have_pty)
980 		enter_raw_mode();
981 
982 	if (compat20) {
983 		session_ident = ssh2_chan_id;
984 		if (escape_char != SSH_ESCAPECHAR_NONE)
985 			channel_register_filter(session_ident,
986 			    simple_escape_filter);
987 		if (session_ident != -1)
988 			channel_register_cleanup(session_ident,
989 			    client_channel_closed);
990 	} else {
991 		/* Check if we should immediately send eof on stdin. */
992 		client_check_initial_eof_on_stdin();
993 	}
994 
995 	/* Main loop of the client for the interactive session mode. */
996 	while (!quit_pending) {
997 
998 		/* Process buffered packets sent by the server. */
999 		client_process_buffered_input_packets();
1000 
1001 		if (compat20 && session_closed && !channel_still_open())
1002 			break;
1003 
1004 		rekeying = (xxx_kex != NULL && !xxx_kex->done);
1005 
1006 		if (rekeying) {
1007 			debug("rekeying in progress");
1008 		} else {
1009 			/*
1010 			 * Make packets of buffered stdin data, and buffer
1011 			 * them for sending to the server.
1012 			 */
1013 			if (!compat20)
1014 				client_make_packets_from_stdin_data();
1015 
1016 			/*
1017 			 * Make packets from buffered channel data, and
1018 			 * enqueue them for sending to the server.
1019 			 */
1020 			if (packet_not_very_much_data_to_write())
1021 				channel_output_poll();
1022 
1023 			/*
1024 			 * Check if the window size has changed, and buffer a
1025 			 * message about it to the server if so.
1026 			 */
1027 			client_check_window_change();
1028 
1029 			if (quit_pending)
1030 				break;
1031 		}
1032 		/*
1033 		 * Wait until we have something to do (something becomes
1034 		 * available on one of the descriptors).
1035 		 */
1036 		max_fd2 = max_fd;
1037 		client_wait_until_can_do_something(&readset, &writeset,
1038 		    &max_fd2, &nalloc, rekeying);
1039 
1040 		if (quit_pending)
1041 			break;
1042 
1043 		/* Do channel operations unless rekeying in progress. */
1044 		if (!rekeying) {
1045 			channel_after_select(readset, writeset);
1046 			if (need_rekeying || packet_need_rekeying()) {
1047 				debug("need rekeying");
1048 				xxx_kex->done = 0;
1049 				kex_send_kexinit(xxx_kex);
1050 				need_rekeying = 0;
1051 			}
1052 		}
1053 
1054 		/* Buffer input from the connection.  */
1055 		client_process_net_input(readset);
1056 
1057 		if (quit_pending)
1058 			break;
1059 
1060 		if (!compat20) {
1061 			/* Buffer data from stdin */
1062 			client_process_input(readset);
1063 			/*
1064 			 * Process output to stdout and stderr.  Output to
1065 			 * the connection is processed elsewhere (above).
1066 			 */
1067 			client_process_output(writeset);
1068 		}
1069 
1070 		/* Send as much buffered packet data as possible to the sender. */
1071 		if (FD_ISSET(connection_out, writeset))
1072 			packet_write_poll();
1073 	}
1074 	if (readset)
1075 		xfree(readset);
1076 	if (writeset)
1077 		xfree(writeset);
1078 
1079 	/* Terminate the session. */
1080 
1081 	/* Stop watching for window change. */
1082 	if (have_pty)
1083 		signal(SIGWINCH, SIG_DFL);
1084 
1085 	channel_free_all();
1086 
1087 	if (have_pty)
1088 		leave_raw_mode();
1089 
1090 	/* restore blocking io */
1091 	if (!isatty(fileno(stdin)))
1092 		unset_nonblock(fileno(stdin));
1093 	if (!isatty(fileno(stdout)))
1094 		unset_nonblock(fileno(stdout));
1095 	if (!isatty(fileno(stderr)))
1096 		unset_nonblock(fileno(stderr));
1097 
1098 	/*
1099 	 * If there was no shell or command requested, there will be no remote
1100 	 * exit status to be returned.  In that case, clear error code if the
1101 	 * connection was deliberately terminated at this end.
1102 	 */
1103 	if (no_shell_flag && received_signal == SIGTERM) {
1104 		received_signal = 0;
1105 		exit_status = 0;
1106 	}
1107 
1108 	if (received_signal)
1109 		fatal("Killed by signal %d.", (int) received_signal);
1110 
1111 	/*
1112 	 * In interactive mode (with pseudo tty) display a message indicating
1113 	 * that the connection has been closed.
1114 	 */
1115 	if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1116 		snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
1117 		buffer_append(&stderr_buffer, buf, strlen(buf));
1118 	}
1119 
1120 	/* Output any buffered data for stdout. */
1121 	while (buffer_len(&stdout_buffer) > 0) {
1122 		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
1123 		    buffer_len(&stdout_buffer));
1124 		if (len <= 0) {
1125 			error("Write failed flushing stdout buffer.");
1126 			break;
1127 		}
1128 		buffer_consume(&stdout_buffer, len);
1129 		stdout_bytes += len;
1130 	}
1131 
1132 	/* Output any buffered data for stderr. */
1133 	while (buffer_len(&stderr_buffer) > 0) {
1134 		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
1135 		    buffer_len(&stderr_buffer));
1136 		if (len <= 0) {
1137 			error("Write failed flushing stderr buffer.");
1138 			break;
1139 		}
1140 		buffer_consume(&stderr_buffer, len);
1141 		stderr_bytes += len;
1142 	}
1143 
1144 	/* Clear and free any buffers. */
1145 	memset(buf, 0, sizeof(buf));
1146 	buffer_free(&stdin_buffer);
1147 	buffer_free(&stdout_buffer);
1148 	buffer_free(&stderr_buffer);
1149 
1150 	/* Report bytes transferred, and transfer rates. */
1151 	total_time = get_current_time() - start_time;
1152 	debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
1153 	    stdin_bytes, stdout_bytes, stderr_bytes, total_time);
1154 	if (total_time > 0)
1155 		debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
1156 		    stdin_bytes / total_time, stdout_bytes / total_time,
1157 		    stderr_bytes / total_time);
1158 
1159 	/* Return the exit status of the program. */
1160 	debug("Exit status %d", exit_status);
1161 	return exit_status;
1162 }
1163 
1164 /*********/
1165 
1166 static void
1167 client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
1168 {
1169 	u_int data_len;
1170 	char *data = packet_get_string(&data_len);
1171 	packet_check_eom();
1172 	buffer_append(&stdout_buffer, data, data_len);
1173 	memset(data, 0, data_len);
1174 	xfree(data);
1175 }
1176 static void
1177 client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
1178 {
1179 	u_int data_len;
1180 	char *data = packet_get_string(&data_len);
1181 	packet_check_eom();
1182 	buffer_append(&stderr_buffer, data, data_len);
1183 	memset(data, 0, data_len);
1184 	xfree(data);
1185 }
1186 static void
1187 client_input_exit_status(int type, u_int32_t seq, void *ctxt)
1188 {
1189 	exit_status = packet_get_int();
1190 	packet_check_eom();
1191 	/* Acknowledge the exit. */
1192 	packet_start(SSH_CMSG_EXIT_CONFIRMATION);
1193 	packet_send();
1194 	/*
1195 	 * Must wait for packet to be sent since we are
1196 	 * exiting the loop.
1197 	 */
1198 	packet_write_wait();
1199 	/* Flag that we want to exit. */
1200 	quit_pending = 1;
1201 }
1202 static void
1203 client_input_agent_open(int type, u_int32_t seq, void *ctxt)
1204 {
1205 	Channel *c = NULL;
1206 	int remote_id, sock;
1207 
1208 	/* Read the remote channel number from the message. */
1209 	remote_id = packet_get_int();
1210 	packet_check_eom();
1211 
1212 	/*
1213 	 * Get a connection to the local authentication agent (this may again
1214 	 * get forwarded).
1215 	 */
1216 	sock = ssh_get_authentication_socket();
1217 
1218 	/*
1219 	 * If we could not connect the agent, send an error message back to
1220 	 * the server. This should never happen unless the agent dies,
1221 	 * because authentication forwarding is only enabled if we have an
1222 	 * agent.
1223 	 */
1224 	if (sock >= 0) {
1225 		c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
1226 		    -1, 0, 0, 0, "authentication agent connection", 1);
1227 		c->remote_id = remote_id;
1228 		c->force_drain = 1;
1229 	}
1230 	if (c == NULL) {
1231 		packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1232 		packet_put_int(remote_id);
1233 	} else {
1234 		/* Send a confirmation to the remote host. */
1235 		debug("Forwarding authentication connection.");
1236 		packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1237 		packet_put_int(remote_id);
1238 		packet_put_int(c->self);
1239 	}
1240 	packet_send();
1241 }
1242 
1243 static Channel *
1244 client_request_forwarded_tcpip(const char *request_type, int rchan)
1245 {
1246 	Channel *c = NULL;
1247 	char *listen_address, *originator_address;
1248 	int listen_port, originator_port;
1249 	int sock;
1250 
1251 	/* Get rest of the packet */
1252 	listen_address = packet_get_string(NULL);
1253 	listen_port = packet_get_int();
1254 	originator_address = packet_get_string(NULL);
1255 	originator_port = packet_get_int();
1256 	packet_check_eom();
1257 
1258 	debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
1259 	    listen_address, listen_port, originator_address, originator_port);
1260 
1261 	sock = channel_connect_by_listen_address(listen_port);
1262 	if (sock < 0) {
1263 		xfree(originator_address);
1264 		xfree(listen_address);
1265 		return NULL;
1266 	}
1267 	c = channel_new("forwarded-tcpip",
1268 	    SSH_CHANNEL_CONNECTING, sock, sock, -1,
1269 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1270 	    originator_address, 1);
1271 	xfree(originator_address);
1272 	xfree(listen_address);
1273 	return c;
1274 }
1275 
1276 static Channel *
1277 client_request_x11(const char *request_type, int rchan)
1278 {
1279 	Channel *c = NULL;
1280 	char *originator;
1281 	int originator_port;
1282 	int sock;
1283 
1284 	if (!options.forward_x11) {
1285 		error("Warning: ssh server tried X11 forwarding.");
1286 		error("Warning: this is probably a break in attempt by a malicious server.");
1287 		return NULL;
1288 	}
1289 	originator = packet_get_string(NULL);
1290 	if (datafellows & SSH_BUG_X11FWD) {
1291 		debug2("buggy server: x11 request w/o originator_port");
1292 		originator_port = 0;
1293 	} else {
1294 		originator_port = packet_get_int();
1295 	}
1296 	packet_check_eom();
1297 	/* XXX check permission */
1298 	debug("client_request_x11: request from %s %d", originator,
1299 	    originator_port);
1300 	xfree(originator);
1301 	sock = x11_connect_display();
1302 	if (sock < 0)
1303 		return NULL;
1304 	c = channel_new("x11",
1305 	    SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1306 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1307 	c->force_drain = 1;
1308 	return c;
1309 }
1310 
1311 static Channel *
1312 client_request_agent(const char *request_type, int rchan)
1313 {
1314 	Channel *c = NULL;
1315 	int sock;
1316 
1317 	if (!options.forward_agent) {
1318 		error("Warning: ssh server tried agent forwarding.");
1319 		error("Warning: this is probably a break in attempt by a malicious server.");
1320 		return NULL;
1321 	}
1322 	sock =  ssh_get_authentication_socket();
1323 	if (sock < 0)
1324 		return NULL;
1325 	c = channel_new("authentication agent connection",
1326 	    SSH_CHANNEL_OPEN, sock, sock, -1,
1327 	    CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
1328 	    "authentication agent connection", 1);
1329 	c->force_drain = 1;
1330 	return c;
1331 }
1332 
1333 /* XXXX move to generic input handler */
1334 static void
1335 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
1336 {
1337 	Channel *c = NULL;
1338 	char *ctype;
1339 	int rchan;
1340 	u_int rmaxpack, rwindow, len;
1341 
1342 	ctype = packet_get_string(&len);
1343 	rchan = packet_get_int();
1344 	rwindow = packet_get_int();
1345 	rmaxpack = packet_get_int();
1346 
1347 	debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1348 	    ctype, rchan, rwindow, rmaxpack);
1349 
1350 	if (strcmp(ctype, "forwarded-tcpip") == 0) {
1351 		c = client_request_forwarded_tcpip(ctype, rchan);
1352 	} else if (strcmp(ctype, "x11") == 0) {
1353 		c = client_request_x11(ctype, rchan);
1354 	} else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1355 		c = client_request_agent(ctype, rchan);
1356 	}
1357 /* XXX duplicate : */
1358 	if (c != NULL) {
1359 		debug("confirm %s", ctype);
1360 		c->remote_id = rchan;
1361 		c->remote_window = rwindow;
1362 		c->remote_maxpacket = rmaxpack;
1363 		if (c->type != SSH_CHANNEL_CONNECTING) {
1364 			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1365 			packet_put_int(c->remote_id);
1366 			packet_put_int(c->self);
1367 			packet_put_int(c->local_window);
1368 			packet_put_int(c->local_maxpacket);
1369 			packet_send();
1370 		}
1371 	} else {
1372 		debug("failure %s", ctype);
1373 		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1374 		packet_put_int(rchan);
1375 		packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1376 		if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1377 			packet_put_cstring("open failed");
1378 			packet_put_cstring("");
1379 		}
1380 		packet_send();
1381 	}
1382 	xfree(ctype);
1383 }
1384 static void
1385 client_input_channel_req(int type, u_int32_t seq, void *ctxt)
1386 {
1387 	Channel *c = NULL;
1388 	int id, reply, success = 0;
1389 	char *rtype;
1390 
1391 	id = packet_get_int();
1392 	rtype = packet_get_string(NULL);
1393 	reply = packet_get_char();
1394 
1395 	debug("client_input_channel_req: channel %d rtype %s reply %d",
1396 	    id, rtype, reply);
1397 
1398 	if (session_ident == -1) {
1399 		error("client_input_channel_req: no channel %d", session_ident);
1400 	} else if (id != session_ident) {
1401 		error("client_input_channel_req: channel %d: wrong channel: %d",
1402 		    session_ident, id);
1403 	}
1404 	c = channel_lookup(id);
1405 	if (c == NULL) {
1406 		error("client_input_channel_req: channel %d: unknown channel", id);
1407 	} else if (strcmp(rtype, "exit-status") == 0) {
1408 		success = 1;
1409 		exit_status = packet_get_int();
1410 		packet_check_eom();
1411 	}
1412 	if (reply) {
1413 		packet_start(success ?
1414 		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1415 		packet_put_int(c->remote_id);
1416 		packet_send();
1417 	}
1418 	xfree(rtype);
1419 }
1420 static void
1421 client_input_global_request(int type, u_int32_t seq, void *ctxt)
1422 {
1423 	char *rtype;
1424 	int want_reply;
1425 	int success = 0;
1426 
1427 	rtype = packet_get_string(NULL);
1428 	want_reply = packet_get_char();
1429 	debug("client_input_global_request: rtype %s want_reply %d",
1430 	    rtype, want_reply);
1431 	if (want_reply) {
1432 		packet_start(success ?
1433 		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1434 		packet_send();
1435 		packet_write_wait();
1436 	}
1437 	xfree(rtype);
1438 }
1439 
1440 static void
1441 client_init_dispatch_20(void)
1442 {
1443 	dispatch_init(&dispatch_protocol_error);
1444 
1445 	dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1446 	dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1447 	dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1448 	dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1449 	dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
1450 	dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1451 	dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1452 	dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
1453 	dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1454 	dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1455 
1456 	/* rekeying */
1457 	dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1458 
1459 	/* global request reply messages */
1460 	dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
1461 	dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1462 }
1463 static void
1464 client_init_dispatch_13(void)
1465 {
1466 	dispatch_init(NULL);
1467 	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1468 	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1469 	dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1470 	dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1471 	dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1472 	dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1473 	dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
1474 	dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
1475 	dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
1476 
1477 	dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
1478 	    &client_input_agent_open : &deny_input_open);
1479 	dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
1480 	    &x11_input_open : &deny_input_open);
1481 }
1482 static void
1483 client_init_dispatch_15(void)
1484 {
1485 	client_init_dispatch_13();
1486 	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1487 	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
1488 }
1489 static void
1490 client_init_dispatch(void)
1491 {
1492 	if (compat20)
1493 		client_init_dispatch_20();
1494 	else if (compat13)
1495 		client_init_dispatch_13();
1496 	else
1497 		client_init_dispatch_15();
1498 }
1499 
1500 /* client specific fatal cleanup */
1501 void
1502 cleanup_exit(int i)
1503 {
1504 	leave_raw_mode();
1505 	leave_non_blocking();
1506 	_exit(i);
1507 }
1508