serverloop.c revision 323129
1/* $OpenBSD: serverloop.c,v 1.184 2016/03/07 19:02:43 djm Exp $ */
2/*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 *                    All rights reserved
6 * Server main loop for handling the interactive session.
7 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose.  Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 *
14 * SSH2 support by Markus Friedl.
15 * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 *    notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 *    notice, this list of conditions and the following disclaimer in the
24 *    documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include "includes.h"
39
40#include <sys/param.h>	/* MIN MAX */
41#include <sys/types.h>
42#include <sys/wait.h>
43#include <sys/socket.h>
44#ifdef HAVE_SYS_TIME_H
45# include <sys/time.h>
46#endif
47
48#include <netinet/in.h>
49
50#include <errno.h>
51#include <fcntl.h>
52#include <pwd.h>
53#include <signal.h>
54#include <string.h>
55#include <termios.h>
56#include <unistd.h>
57#include <stdarg.h>
58
59#include "openbsd-compat/sys-queue.h"
60#include "xmalloc.h"
61#include "packet.h"
62#include "buffer.h"
63#include "log.h"
64#include "misc.h"
65#include "servconf.h"
66#include "canohost.h"
67#include "sshpty.h"
68#include "channels.h"
69#include "compat.h"
70#include "ssh1.h"
71#include "ssh2.h"
72#include "key.h"
73#include "cipher.h"
74#include "kex.h"
75#include "hostfile.h"
76#include "auth.h"
77#include "session.h"
78#include "dispatch.h"
79#include "auth-options.h"
80#include "serverloop.h"
81#include "ssherr.h"
82
83extern ServerOptions options;
84
85/* XXX */
86extern Authctxt *the_authctxt;
87extern int use_privsep;
88
89static Buffer stdin_buffer;	/* Buffer for stdin data. */
90static Buffer stdout_buffer;	/* Buffer for stdout data. */
91static Buffer stderr_buffer;	/* Buffer for stderr data. */
92static int fdin;		/* Descriptor for stdin (for writing) */
93static int fdout;		/* Descriptor for stdout (for reading);
94				   May be same number as fdin. */
95static int fderr;		/* Descriptor for stderr.  May be -1. */
96static long stdin_bytes = 0;	/* Number of bytes written to stdin. */
97static long stdout_bytes = 0;	/* Number of stdout bytes sent to client. */
98static long stderr_bytes = 0;	/* Number of stderr bytes sent to client. */
99static long fdout_bytes = 0;	/* Number of stdout bytes read from program. */
100static int stdin_eof = 0;	/* EOF message received from client. */
101static int fdout_eof = 0;	/* EOF encountered reading from fdout. */
102static int fderr_eof = 0;	/* EOF encountered readung from fderr. */
103static int fdin_is_tty = 0;	/* fdin points to a tty. */
104static int connection_in;	/* Connection to client (input). */
105static int connection_out;	/* Connection to client (output). */
106static int connection_closed = 0;	/* Connection to client closed. */
107static u_int buffer_high;	/* "Soft" max buffer size. */
108static int no_more_sessions = 0; /* Disallow further sessions. */
109
110/*
111 * This SIGCHLD kludge is used to detect when the child exits.  The server
112 * will exit after that, as soon as forwarded connections have terminated.
113 */
114
115static volatile sig_atomic_t child_terminated = 0;	/* The child has terminated. */
116
117/* Cleanup on signals (!use_privsep case only) */
118static volatile sig_atomic_t received_sigterm = 0;
119
120/* prototypes */
121static void server_init_dispatch(void);
122
123/*
124 * we write to this pipe if a SIGCHLD is caught in order to avoid
125 * the race between select() and child_terminated
126 */
127static int notify_pipe[2];
128static void
129notify_setup(void)
130{
131	if (pipe(notify_pipe) < 0) {
132		error("pipe(notify_pipe) failed %s", strerror(errno));
133	} else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
134	    (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) {
135		error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
136		close(notify_pipe[0]);
137		close(notify_pipe[1]);
138	} else {
139		set_nonblock(notify_pipe[0]);
140		set_nonblock(notify_pipe[1]);
141		return;
142	}
143	notify_pipe[0] = -1;	/* read end */
144	notify_pipe[1] = -1;	/* write end */
145}
146static void
147notify_parent(void)
148{
149	if (notify_pipe[1] != -1)
150		(void)write(notify_pipe[1], "", 1);
151}
152static void
153notify_prepare(fd_set *readset)
154{
155	if (notify_pipe[0] != -1)
156		FD_SET(notify_pipe[0], readset);
157}
158static void
159notify_done(fd_set *readset)
160{
161	char c;
162
163	if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
164		while (read(notify_pipe[0], &c, 1) != -1)
165			debug2("notify_done: reading");
166}
167
168/*ARGSUSED*/
169static void
170sigchld_handler(int sig)
171{
172	int save_errno = errno;
173	child_terminated = 1;
174#ifndef _UNICOS
175	mysignal(SIGCHLD, sigchld_handler);
176#endif
177	notify_parent();
178	errno = save_errno;
179}
180
181/*ARGSUSED*/
182static void
183sigterm_handler(int sig)
184{
185	received_sigterm = sig;
186}
187
188/*
189 * Make packets from buffered stderr data, and buffer it for sending
190 * to the client.
191 */
192static void
193make_packets_from_stderr_data(void)
194{
195	u_int len;
196
197	/* Send buffered stderr data to the client. */
198	while (buffer_len(&stderr_buffer) > 0 &&
199	    packet_not_very_much_data_to_write()) {
200		len = buffer_len(&stderr_buffer);
201		if (packet_is_interactive()) {
202			if (len > 512)
203				len = 512;
204		} else {
205			/* Keep the packets at reasonable size. */
206			if (len > packet_get_maxsize())
207				len = packet_get_maxsize();
208		}
209		packet_start(SSH_SMSG_STDERR_DATA);
210		packet_put_string(buffer_ptr(&stderr_buffer), len);
211		packet_send();
212		buffer_consume(&stderr_buffer, len);
213		stderr_bytes += len;
214	}
215}
216
217/*
218 * Make packets from buffered stdout data, and buffer it for sending to the
219 * client.
220 */
221static void
222make_packets_from_stdout_data(void)
223{
224	u_int len;
225
226	/* Send buffered stdout data to the client. */
227	while (buffer_len(&stdout_buffer) > 0 &&
228	    packet_not_very_much_data_to_write()) {
229		len = buffer_len(&stdout_buffer);
230		if (packet_is_interactive()) {
231			if (len > 512)
232				len = 512;
233		} else {
234			/* Keep the packets at reasonable size. */
235			if (len > packet_get_maxsize())
236				len = packet_get_maxsize();
237		}
238		packet_start(SSH_SMSG_STDOUT_DATA);
239		packet_put_string(buffer_ptr(&stdout_buffer), len);
240		packet_send();
241		buffer_consume(&stdout_buffer, len);
242		stdout_bytes += len;
243	}
244}
245
246static void
247client_alive_check(void)
248{
249	int channel_id;
250
251	/* timeout, check to see how many we have had */
252	if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
253		logit("Timeout, client not responding.");
254		cleanup_exit(255);
255	}
256
257	/*
258	 * send a bogus global/channel request with "wantreply",
259	 * we should get back a failure
260	 */
261	if ((channel_id = channel_find_open()) == -1) {
262		packet_start(SSH2_MSG_GLOBAL_REQUEST);
263		packet_put_cstring("keepalive@openssh.com");
264		packet_put_char(1);	/* boolean: want reply */
265	} else {
266		channel_request_start(channel_id, "keepalive@openssh.com", 1);
267	}
268	packet_send();
269}
270
271/*
272 * Sleep in select() until we can do something.  This will initialize the
273 * select masks.  Upon return, the masks will indicate which descriptors
274 * have data or can accept data.  Optionally, a maximum time can be specified
275 * for the duration of the wait (0 = infinite).
276 */
277static void
278wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
279    u_int *nallocp, u_int64_t max_time_ms)
280{
281	struct timeval tv, *tvp;
282	int ret;
283	time_t minwait_secs = 0;
284	int client_alive_scheduled = 0;
285	int program_alive_scheduled = 0;
286
287	/* Allocate and update select() masks for channel descriptors. */
288	channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
289	    &minwait_secs, 0);
290
291	/* XXX need proper deadline system for rekey/client alive */
292	if (minwait_secs != 0)
293		max_time_ms = MIN(max_time_ms, (u_int)minwait_secs * 1000);
294
295	/*
296	 * if using client_alive, set the max timeout accordingly,
297	 * and indicate that this particular timeout was for client
298	 * alive by setting the client_alive_scheduled flag.
299	 *
300	 * this could be randomized somewhat to make traffic
301	 * analysis more difficult, but we're not doing it yet.
302	 */
303	if (compat20 && options.client_alive_interval) {
304		uint64_t keepalive_ms =
305		    (uint64_t)options.client_alive_interval * 1000;
306
307		client_alive_scheduled = 1;
308		if (max_time_ms == 0 || max_time_ms > keepalive_ms)
309			max_time_ms = keepalive_ms;
310	}
311
312	if (compat20) {
313#if 0
314		/* wrong: bad condition XXX */
315		if (channel_not_very_much_buffered_data())
316#endif
317		FD_SET(connection_in, *readsetp);
318	} else {
319		/*
320		 * Read packets from the client unless we have too much
321		 * buffered stdin or channel data.
322		 */
323		if (buffer_len(&stdin_buffer) < buffer_high &&
324		    channel_not_very_much_buffered_data())
325			FD_SET(connection_in, *readsetp);
326		/*
327		 * If there is not too much data already buffered going to
328		 * the client, try to get some more data from the program.
329		 */
330		if (packet_not_very_much_data_to_write()) {
331			program_alive_scheduled = child_terminated;
332			if (!fdout_eof)
333				FD_SET(fdout, *readsetp);
334			if (!fderr_eof)
335				FD_SET(fderr, *readsetp);
336		}
337		/*
338		 * If we have buffered data, try to write some of that data
339		 * to the program.
340		 */
341		if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
342			FD_SET(fdin, *writesetp);
343	}
344	notify_prepare(*readsetp);
345
346	/*
347	 * If we have buffered packet data going to the client, mark that
348	 * descriptor.
349	 */
350	if (packet_have_data_to_write())
351		FD_SET(connection_out, *writesetp);
352
353	/*
354	 * If child has terminated and there is enough buffer space to read
355	 * from it, then read as much as is available and exit.
356	 */
357	if (child_terminated && packet_not_very_much_data_to_write())
358		if (max_time_ms == 0 || client_alive_scheduled)
359			max_time_ms = 100;
360
361	if (max_time_ms == 0)
362		tvp = NULL;
363	else {
364		tv.tv_sec = max_time_ms / 1000;
365		tv.tv_usec = 1000 * (max_time_ms % 1000);
366		tvp = &tv;
367	}
368
369	/* Wait for something to happen, or the timeout to expire. */
370	ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
371
372	if (ret == -1) {
373		memset(*readsetp, 0, *nallocp);
374		memset(*writesetp, 0, *nallocp);
375		if (errno != EINTR)
376			error("select: %.100s", strerror(errno));
377	} else {
378		if (ret == 0 && client_alive_scheduled)
379			client_alive_check();
380		if (!compat20 && program_alive_scheduled && fdin_is_tty) {
381			if (!fdout_eof)
382				FD_SET(fdout, *readsetp);
383			if (!fderr_eof)
384				FD_SET(fderr, *readsetp);
385		}
386	}
387
388	notify_done(*readsetp);
389}
390
391/*
392 * Processes input from the client and the program.  Input data is stored
393 * in buffers and processed later.
394 */
395static void
396process_input(fd_set *readset)
397{
398	struct ssh *ssh = active_state; /* XXX */
399	int len;
400	char buf[16384];
401
402	/* Read and buffer any input data from the client. */
403	if (FD_ISSET(connection_in, readset)) {
404		len = read(connection_in, buf, sizeof(buf));
405		if (len == 0) {
406			verbose("Connection closed by %.100s port %d",
407			    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
408			connection_closed = 1;
409			if (compat20)
410				return;
411			cleanup_exit(255);
412		} else if (len < 0) {
413			if (errno != EINTR && errno != EAGAIN &&
414			    errno != EWOULDBLOCK) {
415				verbose("Read error from remote host "
416				    "%.100s port %d: %.100s",
417				    ssh_remote_ipaddr(ssh),
418				    ssh_remote_port(ssh), strerror(errno));
419				cleanup_exit(255);
420			}
421		} else {
422			/* Buffer any received data. */
423			packet_process_incoming(buf, len);
424		}
425	}
426	if (compat20)
427		return;
428
429	/* Read and buffer any available stdout data from the program. */
430	if (!fdout_eof && FD_ISSET(fdout, readset)) {
431		errno = 0;
432		len = read(fdout, buf, sizeof(buf));
433		if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
434		    errno == EWOULDBLOCK) && !child_terminated))) {
435			/* do nothing */
436#ifndef PTY_ZEROREAD
437		} else if (len <= 0) {
438#else
439		} else if ((!isatty(fdout) && len <= 0) ||
440		    (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
441#endif
442			fdout_eof = 1;
443		} else {
444			buffer_append(&stdout_buffer, buf, len);
445			fdout_bytes += len;
446		}
447	}
448	/* Read and buffer any available stderr data from the program. */
449	if (!fderr_eof && FD_ISSET(fderr, readset)) {
450		errno = 0;
451		len = read(fderr, buf, sizeof(buf));
452		if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
453		    errno == EWOULDBLOCK) && !child_terminated))) {
454			/* do nothing */
455#ifndef PTY_ZEROREAD
456		} else if (len <= 0) {
457#else
458		} else if ((!isatty(fderr) && len <= 0) ||
459		    (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
460#endif
461			fderr_eof = 1;
462		} else {
463			buffer_append(&stderr_buffer, buf, len);
464		}
465	}
466}
467
468/*
469 * Sends data from internal buffers to client program stdin.
470 */
471static void
472process_output(fd_set *writeset)
473{
474	struct termios tio;
475	u_char *data;
476	u_int dlen;
477	int len;
478
479	/* Write buffered data to program stdin. */
480	if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
481		data = buffer_ptr(&stdin_buffer);
482		dlen = buffer_len(&stdin_buffer);
483		len = write(fdin, data, dlen);
484		if (len < 0 &&
485		    (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
486			/* do nothing */
487		} else if (len <= 0) {
488			if (fdin != fdout)
489				close(fdin);
490			else
491				shutdown(fdin, SHUT_WR); /* We will no longer send. */
492			fdin = -1;
493		} else {
494			/* Successful write. */
495			if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
496			    tcgetattr(fdin, &tio) == 0 &&
497			    !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
498				/*
499				 * Simulate echo to reduce the impact of
500				 * traffic analysis
501				 */
502				packet_send_ignore(len);
503				packet_send();
504			}
505			/* Consume the data from the buffer. */
506			buffer_consume(&stdin_buffer, len);
507			/* Update the count of bytes written to the program. */
508			stdin_bytes += len;
509		}
510	}
511	/* Send any buffered packet data to the client. */
512	if (FD_ISSET(connection_out, writeset))
513		packet_write_poll();
514}
515
516/*
517 * Wait until all buffered output has been sent to the client.
518 * This is used when the program terminates.
519 */
520static void
521drain_output(void)
522{
523	/* Send any buffered stdout data to the client. */
524	if (buffer_len(&stdout_buffer) > 0) {
525		packet_start(SSH_SMSG_STDOUT_DATA);
526		packet_put_string(buffer_ptr(&stdout_buffer),
527				  buffer_len(&stdout_buffer));
528		packet_send();
529		/* Update the count of sent bytes. */
530		stdout_bytes += buffer_len(&stdout_buffer);
531	}
532	/* Send any buffered stderr data to the client. */
533	if (buffer_len(&stderr_buffer) > 0) {
534		packet_start(SSH_SMSG_STDERR_DATA);
535		packet_put_string(buffer_ptr(&stderr_buffer),
536				  buffer_len(&stderr_buffer));
537		packet_send();
538		/* Update the count of sent bytes. */
539		stderr_bytes += buffer_len(&stderr_buffer);
540	}
541	/* Wait until all buffered data has been written to the client. */
542	packet_write_wait();
543}
544
545static void
546process_buffered_input_packets(void)
547{
548	dispatch_run(DISPATCH_NONBLOCK, NULL, active_state);
549}
550
551/*
552 * Performs the interactive session.  This handles data transmission between
553 * the client and the program.  Note that the notion of stdin, stdout, and
554 * stderr in this function is sort of reversed: this function writes to
555 * stdin (of the child program), and reads from stdout and stderr (of the
556 * child program).
557 */
558void
559server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
560{
561	fd_set *readset = NULL, *writeset = NULL;
562	int max_fd = 0;
563	u_int nalloc = 0;
564	int wait_status;	/* Status returned by wait(). */
565	pid_t wait_pid;		/* pid returned by wait(). */
566	int waiting_termination = 0;	/* Have displayed waiting close message. */
567	u_int64_t max_time_milliseconds;
568	u_int previous_stdout_buffer_bytes;
569	u_int stdout_buffer_bytes;
570	int type;
571
572	debug("Entering interactive session.");
573
574	/* Initialize the SIGCHLD kludge. */
575	child_terminated = 0;
576	mysignal(SIGCHLD, sigchld_handler);
577
578	if (!use_privsep) {
579		signal(SIGTERM, sigterm_handler);
580		signal(SIGINT, sigterm_handler);
581		signal(SIGQUIT, sigterm_handler);
582	}
583
584	/* Initialize our global variables. */
585	fdin = fdin_arg;
586	fdout = fdout_arg;
587	fderr = fderr_arg;
588
589	/* nonblocking IO */
590	set_nonblock(fdin);
591	set_nonblock(fdout);
592	/* we don't have stderr for interactive terminal sessions, see below */
593	if (fderr != -1)
594		set_nonblock(fderr);
595
596	if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
597		fdin_is_tty = 1;
598
599	connection_in = packet_get_connection_in();
600	connection_out = packet_get_connection_out();
601
602	notify_setup();
603
604	previous_stdout_buffer_bytes = 0;
605
606	/* Set approximate I/O buffer size. */
607	if (packet_is_interactive())
608		buffer_high = 4096;
609	else
610		buffer_high = 64 * 1024;
611
612#if 0
613	/* Initialize max_fd to the maximum of the known file descriptors. */
614	max_fd = MAX(connection_in, connection_out);
615	max_fd = MAX(max_fd, fdin);
616	max_fd = MAX(max_fd, fdout);
617	if (fderr != -1)
618		max_fd = MAX(max_fd, fderr);
619#endif
620
621	/* Initialize Initialize buffers. */
622	buffer_init(&stdin_buffer);
623	buffer_init(&stdout_buffer);
624	buffer_init(&stderr_buffer);
625
626	/*
627	 * If we have no separate fderr (which is the case when we have a pty
628	 * - there we cannot make difference between data sent to stdout and
629	 * stderr), indicate that we have seen an EOF from stderr.  This way
630	 * we don't need to check the descriptor everywhere.
631	 */
632	if (fderr == -1)
633		fderr_eof = 1;
634
635	server_init_dispatch();
636
637	/* Main loop of the server for the interactive session mode. */
638	for (;;) {
639
640		/* Process buffered packets from the client. */
641		process_buffered_input_packets();
642
643		/*
644		 * If we have received eof, and there is no more pending
645		 * input data, cause a real eof by closing fdin.
646		 */
647		if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
648			if (fdin != fdout)
649				close(fdin);
650			else
651				shutdown(fdin, SHUT_WR); /* We will no longer send. */
652			fdin = -1;
653		}
654		/* Make packets from buffered stderr data to send to the client. */
655		make_packets_from_stderr_data();
656
657		/*
658		 * Make packets from buffered stdout data to send to the
659		 * client. If there is very little to send, this arranges to
660		 * not send them now, but to wait a short while to see if we
661		 * are getting more data. This is necessary, as some systems
662		 * wake up readers from a pty after each separate character.
663		 */
664		max_time_milliseconds = 0;
665		stdout_buffer_bytes = buffer_len(&stdout_buffer);
666		if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
667		    stdout_buffer_bytes != previous_stdout_buffer_bytes) {
668			/* try again after a while */
669			max_time_milliseconds = 10;
670		} else {
671			/* Send it now. */
672			make_packets_from_stdout_data();
673		}
674		previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
675
676		/* Send channel data to the client. */
677		if (packet_not_very_much_data_to_write())
678			channel_output_poll();
679
680		/*
681		 * Bail out of the loop if the program has closed its output
682		 * descriptors, and we have no more data to send to the
683		 * client, and there is no pending buffered data.
684		 */
685		if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
686		    buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
687			if (!channel_still_open())
688				break;
689			if (!waiting_termination) {
690				const char *s = "Waiting for forwarded connections to terminate...\r\n";
691				char *cp;
692				waiting_termination = 1;
693				buffer_append(&stderr_buffer, s, strlen(s));
694
695				/* Display list of open channels. */
696				cp = channel_open_message();
697				buffer_append(&stderr_buffer, cp, strlen(cp));
698				free(cp);
699			}
700		}
701		max_fd = MAX(connection_in, connection_out);
702		max_fd = MAX(max_fd, fdin);
703		max_fd = MAX(max_fd, fdout);
704		max_fd = MAX(max_fd, fderr);
705		max_fd = MAX(max_fd, notify_pipe[0]);
706
707		/* Sleep in select() until we can do something. */
708		wait_until_can_do_something(&readset, &writeset, &max_fd,
709		    &nalloc, max_time_milliseconds);
710
711		if (received_sigterm) {
712			logit("Exiting on signal %d", (int)received_sigterm);
713			/* Clean up sessions, utmp, etc. */
714			cleanup_exit(255);
715		}
716
717		/* Process any channel events. */
718		channel_after_select(readset, writeset);
719
720		/* Process input from the client and from program stdout/stderr. */
721		process_input(readset);
722
723		/* Process output to the client and to program stdin. */
724		process_output(writeset);
725	}
726	free(readset);
727	free(writeset);
728
729	/* Cleanup and termination code. */
730
731	/* Wait until all output has been sent to the client. */
732	drain_output();
733
734	debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
735	    stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
736
737	/* Free and clear the buffers. */
738	buffer_free(&stdin_buffer);
739	buffer_free(&stdout_buffer);
740	buffer_free(&stderr_buffer);
741
742	/* Close the file descriptors. */
743	if (fdout != -1)
744		close(fdout);
745	fdout = -1;
746	fdout_eof = 1;
747	if (fderr != -1)
748		close(fderr);
749	fderr = -1;
750	fderr_eof = 1;
751	if (fdin != -1)
752		close(fdin);
753	fdin = -1;
754
755	channel_free_all();
756
757	/* We no longer want our SIGCHLD handler to be called. */
758	mysignal(SIGCHLD, SIG_DFL);
759
760	while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
761		if (errno != EINTR)
762			packet_disconnect("wait: %.100s", strerror(errno));
763	if (wait_pid != pid)
764		error("Strange, wait returned pid %ld, expected %ld",
765		    (long)wait_pid, (long)pid);
766
767	/* Check if it exited normally. */
768	if (WIFEXITED(wait_status)) {
769		/* Yes, normal exit.  Get exit status and send it to the client. */
770		debug("Command exited with status %d.", WEXITSTATUS(wait_status));
771		packet_start(SSH_SMSG_EXITSTATUS);
772		packet_put_int(WEXITSTATUS(wait_status));
773		packet_send();
774		packet_write_wait();
775
776		/*
777		 * Wait for exit confirmation.  Note that there might be
778		 * other packets coming before it; however, the program has
779		 * already died so we just ignore them.  The client is
780		 * supposed to respond with the confirmation when it receives
781		 * the exit status.
782		 */
783		do {
784			type = packet_read();
785		}
786		while (type != SSH_CMSG_EXIT_CONFIRMATION);
787
788		debug("Received exit confirmation.");
789		return;
790	}
791	/* Check if the program terminated due to a signal. */
792	if (WIFSIGNALED(wait_status))
793		packet_disconnect("Command terminated on signal %d.",
794				  WTERMSIG(wait_status));
795
796	/* Some weird exit cause.  Just exit. */
797	packet_disconnect("wait returned status %04x.", wait_status);
798	/* NOTREACHED */
799}
800
801static void
802collect_children(void)
803{
804	pid_t pid;
805	sigset_t oset, nset;
806	int status;
807
808	/* block SIGCHLD while we check for dead children */
809	sigemptyset(&nset);
810	sigaddset(&nset, SIGCHLD);
811	sigprocmask(SIG_BLOCK, &nset, &oset);
812	if (child_terminated) {
813		debug("Received SIGCHLD.");
814		while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
815		    (pid < 0 && errno == EINTR))
816			if (pid > 0)
817				session_close_by_pid(pid, status);
818		child_terminated = 0;
819	}
820	sigprocmask(SIG_SETMASK, &oset, NULL);
821}
822
823void
824server_loop2(Authctxt *authctxt)
825{
826	fd_set *readset = NULL, *writeset = NULL;
827	int max_fd;
828	u_int nalloc = 0;
829	u_int64_t rekey_timeout_ms = 0;
830
831	debug("Entering interactive session for SSH2.");
832
833	mysignal(SIGCHLD, sigchld_handler);
834	child_terminated = 0;
835	connection_in = packet_get_connection_in();
836	connection_out = packet_get_connection_out();
837
838	if (!use_privsep) {
839		signal(SIGTERM, sigterm_handler);
840		signal(SIGINT, sigterm_handler);
841		signal(SIGQUIT, sigterm_handler);
842	}
843
844	notify_setup();
845
846	max_fd = MAX(connection_in, connection_out);
847	max_fd = MAX(max_fd, notify_pipe[0]);
848
849	server_init_dispatch();
850
851	for (;;) {
852		process_buffered_input_packets();
853
854		if (!ssh_packet_is_rekeying(active_state) &&
855		    packet_not_very_much_data_to_write())
856			channel_output_poll();
857		if (options.rekey_interval > 0 && compat20 &&
858		    !ssh_packet_is_rekeying(active_state))
859			rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
860		else
861			rekey_timeout_ms = 0;
862
863		wait_until_can_do_something(&readset, &writeset, &max_fd,
864		    &nalloc, rekey_timeout_ms);
865
866		if (received_sigterm) {
867			logit("Exiting on signal %d", (int)received_sigterm);
868			/* Clean up sessions, utmp, etc. */
869			cleanup_exit(255);
870		}
871
872		collect_children();
873		if (!ssh_packet_is_rekeying(active_state))
874			channel_after_select(readset, writeset);
875		process_input(readset);
876		if (connection_closed)
877			break;
878		process_output(writeset);
879	}
880	collect_children();
881
882	free(readset);
883	free(writeset);
884
885	/* free all channels, no more reads and writes */
886	channel_free_all();
887
888	/* free remaining sessions, e.g. remove wtmp entries */
889	session_destroy_all(NULL);
890}
891
892static int
893server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
894{
895	debug("Got %d/%u for keepalive", type, seq);
896	/*
897	 * reset timeout, since we got a sane answer from the client.
898	 * even if this was generated by something other than
899	 * the bogus CHANNEL_REQUEST we send for keepalives.
900	 */
901	packet_set_alive_timeouts(0);
902	return 0;
903}
904
905static int
906server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
907{
908	char *data;
909	u_int data_len;
910
911	/* Stdin data from the client.  Append it to the buffer. */
912	/* Ignore any data if the client has closed stdin. */
913	if (fdin == -1)
914		return 0;
915	data = packet_get_string(&data_len);
916	packet_check_eom();
917	buffer_append(&stdin_buffer, data, data_len);
918	explicit_bzero(data, data_len);
919	free(data);
920	return 0;
921}
922
923static int
924server_input_eof(int type, u_int32_t seq, void *ctxt)
925{
926	/*
927	 * Eof from the client.  The stdin descriptor to the
928	 * program will be closed when all buffered data has
929	 * drained.
930	 */
931	debug("EOF received for stdin.");
932	packet_check_eom();
933	stdin_eof = 1;
934	return 0;
935}
936
937static int
938server_input_window_size(int type, u_int32_t seq, void *ctxt)
939{
940	u_int row = packet_get_int();
941	u_int col = packet_get_int();
942	u_int xpixel = packet_get_int();
943	u_int ypixel = packet_get_int();
944
945	debug("Window change received.");
946	packet_check_eom();
947	if (fdin != -1)
948		pty_change_window_size(fdin, row, col, xpixel, ypixel);
949	return 0;
950}
951
952static Channel *
953server_request_direct_tcpip(void)
954{
955	Channel *c = NULL;
956	char *target, *originator;
957	u_short target_port, originator_port;
958
959	target = packet_get_string(NULL);
960	target_port = packet_get_int();
961	originator = packet_get_string(NULL);
962	originator_port = packet_get_int();
963	packet_check_eom();
964
965	debug("server_request_direct_tcpip: originator %s port %d, target %s "
966	    "port %d", originator, originator_port, target, target_port);
967
968	/* XXX fine grained permissions */
969	if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
970	    !no_port_forwarding_flag) {
971		c = channel_connect_to_port(target, target_port,
972		    "direct-tcpip", "direct-tcpip");
973	} else {
974		logit("refused local port forward: "
975		    "originator %s port %d, target %s port %d",
976		    originator, originator_port, target, target_port);
977	}
978
979	free(originator);
980	free(target);
981
982	return c;
983}
984
985static Channel *
986server_request_direct_streamlocal(void)
987{
988	Channel *c = NULL;
989	char *target, *originator;
990	u_short originator_port;
991
992	target = packet_get_string(NULL);
993	originator = packet_get_string(NULL);
994	originator_port = packet_get_int();
995	packet_check_eom();
996
997	debug("server_request_direct_streamlocal: originator %s port %d, target %s",
998	    originator, originator_port, target);
999
1000	/* XXX fine grained permissions */
1001	if ((options.allow_streamlocal_forwarding & FORWARD_LOCAL) != 0 &&
1002	    !no_port_forwarding_flag) {
1003		c = channel_connect_to_path(target,
1004		    "direct-streamlocal@openssh.com", "direct-streamlocal");
1005	} else {
1006		logit("refused streamlocal port forward: "
1007		    "originator %s port %d, target %s",
1008		    originator, originator_port, target);
1009	}
1010
1011	free(originator);
1012	free(target);
1013
1014	return c;
1015}
1016
1017static Channel *
1018server_request_tun(void)
1019{
1020	Channel *c = NULL;
1021	int mode, tun;
1022	int sock;
1023
1024	mode = packet_get_int();
1025	switch (mode) {
1026	case SSH_TUNMODE_POINTOPOINT:
1027	case SSH_TUNMODE_ETHERNET:
1028		break;
1029	default:
1030		packet_send_debug("Unsupported tunnel device mode.");
1031		return NULL;
1032	}
1033	if ((options.permit_tun & mode) == 0) {
1034		packet_send_debug("Server has rejected tunnel device "
1035		    "forwarding");
1036		return NULL;
1037	}
1038
1039	tun = packet_get_int();
1040	if (forced_tun_device != -1) {
1041		if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1042			goto done;
1043		tun = forced_tun_device;
1044	}
1045	sock = tun_open(tun, mode);
1046	if (sock < 0)
1047		goto done;
1048	c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1049	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1050	c->datagram = 1;
1051#if defined(SSH_TUN_FILTER)
1052	if (mode == SSH_TUNMODE_POINTOPOINT)
1053		channel_register_filter(c->self, sys_tun_infilter,
1054		    sys_tun_outfilter, NULL, NULL);
1055#endif
1056
1057 done:
1058	if (c == NULL)
1059		packet_send_debug("Failed to open the tunnel device.");
1060	return c;
1061}
1062
1063static Channel *
1064server_request_session(void)
1065{
1066	Channel *c;
1067
1068	debug("input_session_request");
1069	packet_check_eom();
1070
1071	if (no_more_sessions) {
1072		packet_disconnect("Possible attack: attempt to open a session "
1073		    "after additional sessions disabled");
1074	}
1075
1076	/*
1077	 * A server session has no fd to read or write until a
1078	 * CHANNEL_REQUEST for a shell is made, so we set the type to
1079	 * SSH_CHANNEL_LARVAL.  Additionally, a callback for handling all
1080	 * CHANNEL_REQUEST messages is registered.
1081	 */
1082	c = channel_new("session", SSH_CHANNEL_LARVAL,
1083	    -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1084	    0, "server-session", 1);
1085	if (session_open(the_authctxt, c->self) != 1) {
1086		debug("session open failed, free channel %d", c->self);
1087		channel_free(c);
1088		return NULL;
1089	}
1090	channel_register_cleanup(c->self, session_close_by_channel, 0);
1091	return c;
1092}
1093
1094static int
1095server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1096{
1097	Channel *c = NULL;
1098	char *ctype;
1099	int rchan;
1100	u_int rmaxpack, rwindow, len;
1101
1102	ctype = packet_get_string(&len);
1103	rchan = packet_get_int();
1104	rwindow = packet_get_int();
1105	rmaxpack = packet_get_int();
1106
1107	debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1108	    ctype, rchan, rwindow, rmaxpack);
1109
1110	if (strcmp(ctype, "session") == 0) {
1111		c = server_request_session();
1112	} else if (strcmp(ctype, "direct-tcpip") == 0) {
1113		c = server_request_direct_tcpip();
1114	} else if (strcmp(ctype, "direct-streamlocal@openssh.com") == 0) {
1115		c = server_request_direct_streamlocal();
1116	} else if (strcmp(ctype, "tun@openssh.com") == 0) {
1117		c = server_request_tun();
1118	}
1119	if (c != NULL) {
1120		debug("server_input_channel_open: confirm %s", ctype);
1121		c->remote_id = rchan;
1122		c->remote_window = rwindow;
1123		c->remote_maxpacket = rmaxpack;
1124		if (c->type != SSH_CHANNEL_CONNECTING) {
1125			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1126			packet_put_int(c->remote_id);
1127			packet_put_int(c->self);
1128			packet_put_int(c->local_window);
1129			packet_put_int(c->local_maxpacket);
1130			packet_send();
1131		}
1132	} else {
1133		debug("server_input_channel_open: failure %s", ctype);
1134		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1135		packet_put_int(rchan);
1136		packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1137		if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1138			packet_put_cstring("open failed");
1139			packet_put_cstring("");
1140		}
1141		packet_send();
1142	}
1143	free(ctype);
1144	return 0;
1145}
1146
1147static int
1148server_input_hostkeys_prove(struct sshbuf **respp)
1149{
1150	struct ssh *ssh = active_state; /* XXX */
1151	struct sshbuf *resp = NULL;
1152	struct sshbuf *sigbuf = NULL;
1153	struct sshkey *key = NULL, *key_pub = NULL, *key_prv = NULL;
1154	int r, ndx, success = 0;
1155	const u_char *blob;
1156	u_char *sig = 0;
1157	size_t blen, slen;
1158
1159	if ((resp = sshbuf_new()) == NULL || (sigbuf = sshbuf_new()) == NULL)
1160		fatal("%s: sshbuf_new", __func__);
1161
1162	while (ssh_packet_remaining(ssh) > 0) {
1163		sshkey_free(key);
1164		key = NULL;
1165		if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 ||
1166		    (r = sshkey_from_blob(blob, blen, &key)) != 0) {
1167			error("%s: couldn't parse key: %s",
1168			    __func__, ssh_err(r));
1169			goto out;
1170		}
1171		/*
1172		 * Better check that this is actually one of our hostkeys
1173		 * before attempting to sign anything with it.
1174		 */
1175		if ((ndx = ssh->kex->host_key_index(key, 1, ssh)) == -1) {
1176			error("%s: unknown host %s key",
1177			    __func__, sshkey_type(key));
1178			goto out;
1179		}
1180		/*
1181		 * XXX refactor: make kex->sign just use an index rather
1182		 * than passing in public and private keys
1183		 */
1184		if ((key_prv = get_hostkey_by_index(ndx)) == NULL &&
1185		    (key_pub = get_hostkey_public_by_index(ndx, ssh)) == NULL) {
1186			error("%s: can't retrieve hostkey %d", __func__, ndx);
1187			goto out;
1188		}
1189		sshbuf_reset(sigbuf);
1190		free(sig);
1191		sig = NULL;
1192		if ((r = sshbuf_put_cstring(sigbuf,
1193		    "hostkeys-prove-00@openssh.com")) != 0 ||
1194		    (r = sshbuf_put_string(sigbuf,
1195		    ssh->kex->session_id, ssh->kex->session_id_len)) != 0 ||
1196		    (r = sshkey_puts(key, sigbuf)) != 0 ||
1197		    (r = ssh->kex->sign(key_prv, key_pub, &sig, &slen,
1198		    sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), NULL, 0)) != 0 ||
1199		    (r = sshbuf_put_string(resp, sig, slen)) != 0) {
1200			error("%s: couldn't prepare signature: %s",
1201			    __func__, ssh_err(r));
1202			goto out;
1203		}
1204	}
1205	/* Success */
1206	*respp = resp;
1207	resp = NULL; /* don't free it */
1208	success = 1;
1209 out:
1210	free(sig);
1211	sshbuf_free(resp);
1212	sshbuf_free(sigbuf);
1213	sshkey_free(key);
1214	return success;
1215}
1216
1217static int
1218server_input_global_request(int type, u_int32_t seq, void *ctxt)
1219{
1220	char *rtype;
1221	int want_reply;
1222	int r, success = 0, allocated_listen_port = 0;
1223	struct sshbuf *resp = NULL;
1224
1225	rtype = packet_get_string(NULL);
1226	want_reply = packet_get_char();
1227	debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1228
1229	/* -R style forwarding */
1230	if (strcmp(rtype, "tcpip-forward") == 0) {
1231		struct passwd *pw;
1232		struct Forward fwd;
1233
1234		pw = the_authctxt->pw;
1235		if (pw == NULL || !the_authctxt->valid)
1236			fatal("server_input_global_request: no/invalid user");
1237		memset(&fwd, 0, sizeof(fwd));
1238		fwd.listen_host = packet_get_string(NULL);
1239		fwd.listen_port = (u_short)packet_get_int();
1240		debug("server_input_global_request: tcpip-forward listen %s port %d",
1241		    fwd.listen_host, fwd.listen_port);
1242
1243		/* check permissions */
1244		if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
1245		    no_port_forwarding_flag ||
1246		    (!want_reply && fwd.listen_port == 0) ||
1247		    (fwd.listen_port != 0 && fwd.listen_port < IPPORT_RESERVED &&
1248		    pw->pw_uid != 0)) {
1249			success = 0;
1250			packet_send_debug("Server has disabled port forwarding.");
1251		} else {
1252			/* Start listening on the port */
1253			success = channel_setup_remote_fwd_listener(&fwd,
1254			    &allocated_listen_port, &options.fwd_opts);
1255		}
1256		free(fwd.listen_host);
1257		if ((resp = sshbuf_new()) == NULL)
1258			fatal("%s: sshbuf_new", __func__);
1259		if (allocated_listen_port != 0 &&
1260		    (r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
1261			fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r));
1262	} else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1263		struct Forward fwd;
1264
1265		memset(&fwd, 0, sizeof(fwd));
1266		fwd.listen_host = packet_get_string(NULL);
1267		fwd.listen_port = (u_short)packet_get_int();
1268		debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1269		    fwd.listen_host, fwd.listen_port);
1270
1271		success = channel_cancel_rport_listener(&fwd);
1272		free(fwd.listen_host);
1273	} else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) {
1274		struct Forward fwd;
1275
1276		memset(&fwd, 0, sizeof(fwd));
1277		fwd.listen_path = packet_get_string(NULL);
1278		debug("server_input_global_request: streamlocal-forward listen path %s",
1279		    fwd.listen_path);
1280
1281		/* check permissions */
1282		if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0
1283		    || no_port_forwarding_flag) {
1284			success = 0;
1285			packet_send_debug("Server has disabled port forwarding.");
1286		} else {
1287			/* Start listening on the socket */
1288			success = channel_setup_remote_fwd_listener(
1289			    &fwd, NULL, &options.fwd_opts);
1290		}
1291		free(fwd.listen_path);
1292	} else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) {
1293		struct Forward fwd;
1294
1295		memset(&fwd, 0, sizeof(fwd));
1296		fwd.listen_path = packet_get_string(NULL);
1297		debug("%s: cancel-streamlocal-forward path %s", __func__,
1298		    fwd.listen_path);
1299
1300		success = channel_cancel_rport_listener(&fwd);
1301		free(fwd.listen_path);
1302	} else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1303		no_more_sessions = 1;
1304		success = 1;
1305	} else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {
1306		success = server_input_hostkeys_prove(&resp);
1307	}
1308	if (want_reply) {
1309		packet_start(success ?
1310		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1311		if (success && resp != NULL)
1312			ssh_packet_put_raw(active_state, sshbuf_ptr(resp),
1313			    sshbuf_len(resp));
1314		packet_send();
1315		packet_write_wait();
1316	}
1317	free(rtype);
1318	sshbuf_free(resp);
1319	return 0;
1320}
1321
1322static int
1323server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1324{
1325	Channel *c;
1326	int id, reply, success = 0;
1327	char *rtype;
1328
1329	id = packet_get_int();
1330	rtype = packet_get_string(NULL);
1331	reply = packet_get_char();
1332
1333	debug("server_input_channel_req: channel %d request %s reply %d",
1334	    id, rtype, reply);
1335
1336	if ((c = channel_lookup(id)) == NULL)
1337		packet_disconnect("server_input_channel_req: "
1338		    "unknown channel %d", id);
1339	if (!strcmp(rtype, "eow@openssh.com")) {
1340		packet_check_eom();
1341		chan_rcvd_eow(c);
1342	} else if ((c->type == SSH_CHANNEL_LARVAL ||
1343	    c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1344		success = session_input_channel_req(c, rtype);
1345	if (reply && !(c->flags & CHAN_CLOSE_SENT)) {
1346		packet_start(success ?
1347		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1348		packet_put_int(c->remote_id);
1349		packet_send();
1350	}
1351	free(rtype);
1352	return 0;
1353}
1354
1355static void
1356server_init_dispatch_20(void)
1357{
1358	debug("server_init_dispatch_20");
1359	dispatch_init(&dispatch_protocol_error);
1360	dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1361	dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1362	dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1363	dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1364	dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1365	dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1366	dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1367	dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1368	dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1369	dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1370	/* client_alive */
1371	dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1372	dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1373	dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1374	dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1375	/* rekeying */
1376	dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1377}
1378static void
1379server_init_dispatch_13(void)
1380{
1381	debug("server_init_dispatch_13");
1382	dispatch_init(NULL);
1383	dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1384	dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1385	dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1386	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1387	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1388	dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1389	dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1390	dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1391	dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1392}
1393static void
1394server_init_dispatch_15(void)
1395{
1396	server_init_dispatch_13();
1397	debug("server_init_dispatch_15");
1398	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1399	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1400}
1401static void
1402server_init_dispatch(void)
1403{
1404	if (compat20)
1405		server_init_dispatch_20();
1406	else if (compat13)
1407		server_init_dispatch_13();
1408	else
1409		server_init_dispatch_15();
1410}
1411