[openssh.git] / nchan.c

/* $OpenBSD: nchan.c,v 1.58 2008/05/08 12:02:23 djm Exp $ */
/*
 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"

#include <sys/types.h>
#include <sys/socket.h>

#include <errno.h>
#include <string.h>
#include <stdarg.h>

#include "openbsd-compat/sys-queue.h"
#include "ssh1.h"
#include "ssh2.h"
#include "buffer.h"
#include "packet.h"
#include "channels.h"
#include "compat.h"
#include "log.h"

/*
 * SSH Protocol 1.5 aka New Channel Protocol
 * Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.
 * Written by Markus Friedl in October 1999
 *
 * Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the
 * tear down of channels:
 *
 * 1.3:	strict request-ack-protocol:
 *	CLOSE	->
 *		<-  CLOSE_CONFIRM
 *
 * 1.5:	uses variations of:
 *	IEOF	->
 *		<-  OCLOSE
 *		<-  IEOF
 *	OCLOSE	->
 *	i.e. both sides have to close the channel
 *
 * 2.0: the EOF messages are optional
 *
 * See the debugging output from 'ssh -v' and 'sshd -d' of
 * ssh-1.2.27 as an example.
 *
 */

/* functions manipulating channel states */
/*
 * EVENTS update channel input/output states execute ACTIONS
 */
/*
 * ACTIONS: should never update the channel states
 */
static void	chan_send_ieof1(Channel *);
static void	chan_send_oclose1(Channel *);
static void	chan_send_close2(Channel *);
static void	chan_send_eof2(Channel *);

/* helper */
static void	chan_shutdown_write(Channel *);
static void	chan_shutdown_read(Channel *);

static char *ostates[] = { "open", "drain", "wait_ieof", "closed" };
static char *istates[] = { "open", "drain", "wait_oclose", "closed" };

static void
chan_set_istate(Channel *c, u_int next)
{
	if (c->istate > CHAN_INPUT_CLOSED || next > CHAN_INPUT_CLOSED)
		fatal("chan_set_istate: bad state %d -> %d", c->istate, next);
	debug2("channel %d: input %s -> %s", c->self, istates[c->istate],
	    istates[next]);
	c->istate = next;
}
static void
chan_set_ostate(Channel *c, u_int next)
{
	if (c->ostate > CHAN_OUTPUT_CLOSED || next > CHAN_OUTPUT_CLOSED)
		fatal("chan_set_ostate: bad state %d -> %d", c->ostate, next);
	debug2("channel %d: output %s -> %s", c->self, ostates[c->ostate],
	    ostates[next]);
	c->ostate = next;
}

/*
 * SSH1 specific implementation of event functions
 */

static void
chan_rcvd_oclose1(Channel *c)
{
	debug2("channel %d: rcvd oclose", c->self);
	switch (c->istate) {
	case CHAN_INPUT_WAIT_OCLOSE:
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	case CHAN_INPUT_OPEN:
		chan_shutdown_read(c);
		chan_send_ieof1(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	case CHAN_INPUT_WAIT_DRAIN:
		/* both local read_failed and remote write_failed  */
		chan_send_ieof1(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	default:
		error("channel %d: protocol error: rcvd_oclose for istate %d",
		    c->self, c->istate);
		return;
	}
}
void
chan_read_failed(Channel *c)
{
	debug2("channel %d: read failed", c->self);
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		chan_shutdown_read(c);
		chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
		break;
	default:
		error("channel %d: chan_read_failed for istate %d",
		    c->self, c->istate);
		break;
	}
}
void
chan_ibuf_empty(Channel *c)
{
	debug2("channel %d: ibuf empty", c->self);
	if (buffer_len(&c->input)) {
		error("channel %d: chan_ibuf_empty for non empty buffer",
		    c->self);
		return;
	}
	switch (c->istate) {
	case CHAN_INPUT_WAIT_DRAIN:
		if (compat20) {
			if (!(c->flags & CHAN_CLOSE_SENT))
				chan_send_eof2(c);
			chan_set_istate(c, CHAN_INPUT_CLOSED);
		} else {
			chan_send_ieof1(c);
			chan_set_istate(c, CHAN_INPUT_WAIT_OCLOSE);
		}
		break;
	default:
		error("channel %d: chan_ibuf_empty for istate %d",
		    c->self, c->istate);
		break;
	}
}
static void
chan_rcvd_ieof1(Channel *c)
{
	debug2("channel %d: rcvd ieof", c->self);
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
		break;
	case CHAN_OUTPUT_WAIT_IEOF:
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		break;
	default:
		error("channel %d: protocol error: rcvd_ieof for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
static void
chan_write_failed1(Channel *c)
{
	debug2("channel %d: write failed", c->self);
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		chan_shutdown_write(c);
		chan_send_oclose1(c);
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
		break;
	case CHAN_OUTPUT_WAIT_DRAIN:
		chan_shutdown_write(c);
		chan_send_oclose1(c);
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		break;
	default:
		error("channel %d: chan_write_failed for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
void
chan_obuf_empty(Channel *c)
{
	debug2("channel %d: obuf empty", c->self);
	if (buffer_len(&c->output)) {
		error("channel %d: chan_obuf_empty for non empty buffer",
		    c->self);
		return;
	}
	switch (c->ostate) {
	case CHAN_OUTPUT_WAIT_DRAIN:
		chan_shutdown_write(c);
		if (!compat20)
			chan_send_oclose1(c);
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		break;
	default:
		error("channel %d: internal error: obuf_empty for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
static void
chan_send_ieof1(Channel *c)
{
	debug2("channel %d: send ieof", c->self);
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
	case CHAN_INPUT_WAIT_DRAIN:
		packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
		packet_put_int(c->remote_id);
		packet_send();
		break;
	default:
		error("channel %d: cannot send ieof for istate %d",
		    c->self, c->istate);
		break;
	}
}
static void
chan_send_oclose1(Channel *c)
{
	debug2("channel %d: send oclose", c->self);
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
	case CHAN_OUTPUT_WAIT_DRAIN:
		buffer_clear(&c->output);
		packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
		packet_put_int(c->remote_id);
		packet_send();
		break;
	default:
		error("channel %d: cannot send oclose for ostate %d",
		    c->self, c->ostate);
		break;
	}
}

/*
 * the same for SSH2
 */
static void
chan_rcvd_close2(Channel *c)
{
	debug2("channel %d: rcvd close", c->self);
	if (c->flags & CHAN_CLOSE_RCVD)
		error("channel %d: protocol error: close rcvd twice", c->self);
	c->flags |= CHAN_CLOSE_RCVD;
	if (c->type == SSH_CHANNEL_LARVAL) {
		/* tear down larval channels immediately */
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		return;
	}
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		/*
		 * wait until a data from the channel is consumed if a CLOSE
		 * is received
		 */
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
		break;
	}
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		chan_shutdown_read(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	case CHAN_INPUT_WAIT_DRAIN:
		chan_send_eof2(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	}
}
static void
chan_rcvd_eof2(Channel *c)
{
	debug2("channel %d: rcvd eof", c->self);
	c->flags |= CHAN_EOF_RCVD;
	if (c->ostate == CHAN_OUTPUT_OPEN)
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
}
static void
chan_write_failed2(Channel *c)
{
	debug2("channel %d: write failed", c->self);
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
	case CHAN_OUTPUT_WAIT_DRAIN:
		chan_shutdown_write(c);
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		break;
	default:
		error("channel %d: chan_write_failed for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
static void
chan_send_eof2(Channel *c)
{
	debug2("channel %d: send eof", c->self);
	switch (c->istate) {
	case CHAN_INPUT_WAIT_DRAIN:
		packet_start(SSH2_MSG_CHANNEL_EOF);
		packet_put_int(c->remote_id);
		packet_send();
		c->flags |= CHAN_EOF_SENT;
		break;
	default:
		error("channel %d: cannot send eof for istate %d",
		    c->self, c->istate);
		break;
	}
}
static void
chan_send_close2(Channel *c)
{
	debug2("channel %d: send close", c->self);
	if (c->ostate != CHAN_OUTPUT_CLOSED ||
	    c->istate != CHAN_INPUT_CLOSED) {
		error("channel %d: cannot send close for istate/ostate %d/%d",
		    c->self, c->istate, c->ostate);
	} else if (c->flags & CHAN_CLOSE_SENT) {
		error("channel %d: already sent close", c->self);
	} else {
		packet_start(SSH2_MSG_CHANNEL_CLOSE);
		packet_put_int(c->remote_id);
		packet_send();
		c->flags |= CHAN_CLOSE_SENT;
	}
}

/* shared */

void
chan_rcvd_ieof(Channel *c)
{
	if (compat20)
		chan_rcvd_eof2(c);
	else
		chan_rcvd_ieof1(c);
	if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
	    buffer_len(&c->output) == 0 &&
	    !CHANNEL_EFD_OUTPUT_ACTIVE(c))
		chan_obuf_empty(c);
}
void
chan_rcvd_oclose(Channel *c)
{
	if (compat20)
		chan_rcvd_close2(c);
	else
		chan_rcvd_oclose1(c);
}
void
chan_write_failed(Channel *c)
{
	if (compat20)
		chan_write_failed2(c);
	else
		chan_write_failed1(c);
}

void
chan_mark_dead(Channel *c)
{
	c->type = SSH_CHANNEL_ZOMBIE;
}

int
chan_is_dead(Channel *c, int do_send)
{
	if (c->type == SSH_CHANNEL_ZOMBIE) {
		debug2("channel %d: zombie", c->self);
		return 1;
	}
	if (c->istate != CHAN_INPUT_CLOSED || c->ostate != CHAN_OUTPUT_CLOSED)
		return 0;
	if (!compat20) {
		debug2("channel %d: is dead", c->self);
		return 1;
	}
	if ((datafellows & SSH_BUG_EXTEOF) &&
	    c->extended_usage == CHAN_EXTENDED_WRITE &&
	    c->efd != -1 &&
	    buffer_len(&c->extended) > 0) {
		debug2("channel %d: active efd: %d len %d",
		    c->self, c->efd, buffer_len(&c->extended));
		return 0;
	}
	if (!(c->flags & CHAN_CLOSE_SENT)) {
		if (do_send) {
			chan_send_close2(c);
		} else {
			/* channel would be dead if we sent a close */
			if (c->flags & CHAN_CLOSE_RCVD) {
				debug2("channel %d: almost dead",
				    c->self);
				return 1;
			}
		}
	}
	if ((c->flags & CHAN_CLOSE_SENT) &&
	    (c->flags & CHAN_CLOSE_RCVD)) {
		debug2("channel %d: is dead", c->self);
		return 1;
	}
	return 0;
}

/* helper */
static void
chan_shutdown_write(Channel *c)
{
	buffer_clear(&c->output);
	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
		return;
	/* shutdown failure is allowed if write failed already */
	debug2("channel %d: close_write", c->self);
	if (c->sock != -1) {
		if (shutdown(c->sock, SHUT_WR) < 0)
			debug2("channel %d: chan_shutdown_write: "
			    "shutdown() failed for fd%d: %.100s",
			    c->self, c->sock, strerror(errno));
	} else {
		if (channel_close_fd(&c->wfd) < 0)
			logit("channel %d: chan_shutdown_write: "
			    "close() failed for fd%d: %.100s",
			    c->self, c->wfd, strerror(errno));
	}
}
static void
chan_shutdown_read(Channel *c)
{
	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
		return;
	debug2("channel %d: close_read", c->self);
	if (c->sock != -1) {
		/*
		 * shutdown(sock, SHUT_READ) may return ENOTCONN if the
		 * write side has been closed already. (bug on Linux)
		 * HP-UX may return ENOTCONN also.
		 */
		if (shutdown(c->sock, SHUT_RD) < 0
		    && errno != ENOTCONN)
			error("channel %d: chan_shutdown_read: "
			    "shutdown() failed for fd%d [i%d o%d]: %.100s",
			    c->self, c->sock, c->istate, c->ostate,
			    strerror(errno));
	} else {
		if (channel_close_fd(&c->rfd) < 0)
			logit("channel %d: chan_shutdown_read: "
			    "close() failed for fd%d: %.100s",
			    c->self, c->rfd, strerror(errno));
	}
}
Commit	Line	Data
3593bdc0	1	/* $OpenBSD: nchan.c,v 1.58 2008/05/08 12:02:23 djm Exp $ */
aa3378df	2	/*
8ab5f6b2	3	* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
aa3378df	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
aa3378df	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	15	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	16	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	17	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	18	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	19	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	20	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	21	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	23	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
8efc0c15	26	#include "includes.h"
8efc0c15	27
5b04a8bf	28	#include <sys/types.h>
	29	#include <sys/socket.h>
	30
028094f4	31	#include <errno.h>
00146caa	32	#include <string.h>
31652869	33	#include <stdarg.h>
028094f4	34
3593bdc0	35	#include "openbsd-compat/sys-queue.h"
42f11eb2	36	#include "ssh1.h"
42f11eb2	37	#include "ssh2.h"
8efc0c15	38	#include "buffer.h"
	39	#include "packet.h"
	40	#include "channels.h"
7e7327a1	41	#include "compat.h"
42f11eb2	42	#include "log.h"
8efc0c15	43
f048f3e2	44	/*
	45	* SSH Protocol 1.5 aka New Channel Protocol
	46	* Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.
	47	* Written by Markus Friedl in October 1999
	48	*
	49	* Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the
	50	* tear down of channels:
	51	*
	52	* 1.3: strict request-ack-protocol:
f2107e97	53	* CLOSE ->
f2107e97	54	* <- CLOSE_CONFIRM
f048f3e2	55	*
f048f3e2	56	* 1.5: uses variations of:
f2107e97	57	* IEOF ->
	58	* <- OCLOSE
	59	* <- IEOF
	60	* OCLOSE ->
	61	* i.e. both sides have to close the channel
f048f3e2	62	*
	63	* 2.0: the EOF messages are optional
	64	*
	65	* See the debugging output from 'ssh -v' and 'sshd -d' of
	66	* ssh-1.2.27 as an example.
	67	*
	68	*/
1b73841d	69
7e7327a1	70	/* functions manipulating channel states */
8efc0c15	71	/*
5260325f	72	* EVENTS update channel input/output states execute ACTIONS
8efc0c15	73	*/
7e7327a1	74	/*
	75	* ACTIONS: should never update the channel states
	76	*/
396c147e	77	static void chan_send_ieof1(Channel *);
	78	static void chan_send_oclose1(Channel *);
	79	static void chan_send_close2(Channel *);
	80	static void chan_send_eof2(Channel *);
7e7327a1	81
7e7327a1	82	/* helper */
396c147e	83	static void chan_shutdown_write(Channel *);
396c147e	84	static void chan_shutdown_read(Channel *);
7e7327a1	85
368e9dfc	86	static char *ostates[] = { "open", "drain", "wait_ieof", "closed" };
	87	static char *istates[] = { "open", "drain", "wait_oclose", "closed" };
	88
	89	static void
	90	chan_set_istate(Channel *c, u_int next)
	91	{
	92	if (c->istate > CHAN_INPUT_CLOSED \|\| next > CHAN_INPUT_CLOSED)
	93	fatal("chan_set_istate: bad state %d -> %d", c->istate, next);
d7ac5f18	94	debug2("channel %d: input %s -> %s", c->self, istates[c->istate],
368e9dfc	95	istates[next]);
	96	c->istate = next;
	97	}
	98	static void
	99	chan_set_ostate(Channel *c, u_int next)
	100	{
	101	if (c->ostate > CHAN_OUTPUT_CLOSED \|\| next > CHAN_OUTPUT_CLOSED)
	102	fatal("chan_set_ostate: bad state %d -> %d", c->ostate, next);
d7ac5f18	103	debug2("channel %d: output %s -> %s", c->self, ostates[c->ostate],
368e9dfc	104	ostates[next]);
	105	c->ostate = next;
	106	}
	107
7e7327a1	108	/*
	109	* SSH1 specific implementation of event functions
	110	*/
	111
	112	static void
	113	chan_rcvd_oclose1(Channel *c)
5260325f	114	{
d7ac5f18	115	debug2("channel %d: rcvd oclose", c->self);
5260325f	116	switch (c->istate) {
8efc0c15	117	case CHAN_INPUT_WAIT_OCLOSE:
368e9dfc	118	chan_set_istate(c, CHAN_INPUT_CLOSED);
8efc0c15	119	break;
8efc0c15	120	case CHAN_INPUT_OPEN:
8efc0c15	121	chan_shutdown_read(c);
7e7327a1	122	chan_send_ieof1(c);
368e9dfc	123	chan_set_istate(c, CHAN_INPUT_CLOSED);
48e671d5	124	break;
	125	case CHAN_INPUT_WAIT_DRAIN:
	126	/* both local read_failed and remote write_failed */
7e7327a1	127	chan_send_ieof1(c);
368e9dfc	128	chan_set_istate(c, CHAN_INPUT_CLOSED);
8efc0c15	129	break;
8efc0c15	130	default:
f048f3e2	131	error("channel %d: protocol error: rcvd_oclose for istate %d",
7e7327a1	132	c->self, c->istate);
48e671d5	133	return;
8efc0c15	134	}
8efc0c15	135	}
70bef40e	136	void
70bef40e	137	chan_read_failed(Channel *c)
5260325f	138	{
d7ac5f18	139	debug2("channel %d: read failed", c->self);
5260325f	140	switch (c->istate) {
8efc0c15	141	case CHAN_INPUT_OPEN:
8efc0c15	142	chan_shutdown_read(c);
368e9dfc	143	chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
8efc0c15	144	break;
8efc0c15	145	default:
f048f3e2	146	error("channel %d: chan_read_failed for istate %d",
7e7327a1	147	c->self, c->istate);
8efc0c15	148	break;
	149	}
	150	}
70bef40e	151	void
70bef40e	152	chan_ibuf_empty(Channel *c)
5260325f	153	{
d7ac5f18	154	debug2("channel %d: ibuf empty", c->self);
5260325f	155	if (buffer_len(&c->input)) {
f048f3e2	156	error("channel %d: chan_ibuf_empty for non empty buffer",
7e7327a1	157	c->self);
8efc0c15	158	return;
8efc0c15	159	}
5260325f	160	switch (c->istate) {
8efc0c15	161	case CHAN_INPUT_WAIT_DRAIN:
3057c23b	162	if (compat20) {
	163	if (!(c->flags & CHAN_CLOSE_SENT))
	164	chan_send_eof2(c);
	165	chan_set_istate(c, CHAN_INPUT_CLOSED);
	166	} else {
	167	chan_send_ieof1(c);
	168	chan_set_istate(c, CHAN_INPUT_WAIT_OCLOSE);
	169	}
8efc0c15	170	break;
8efc0c15	171	default:
f048f3e2	172	error("channel %d: chan_ibuf_empty for istate %d",
7e7327a1	173	c->self, c->istate);
8efc0c15	174	break;
	175	}
	176	}
7e7327a1	177	static void
7e7327a1	178	chan_rcvd_ieof1(Channel *c)
5260325f	179	{
d7ac5f18	180	debug2("channel %d: rcvd ieof", c->self);
5260325f	181	switch (c->ostate) {
8efc0c15	182	case CHAN_OUTPUT_OPEN:
368e9dfc	183	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
8efc0c15	184	break;
8efc0c15	185	case CHAN_OUTPUT_WAIT_IEOF:
368e9dfc	186	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
8efc0c15	187	break;
8efc0c15	188	default:
f048f3e2	189	error("channel %d: protocol error: rcvd_ieof for ostate %d",
7e7327a1	190	c->self, c->ostate);
8efc0c15	191	break;
	192	}
	193	}
7e7327a1	194	static void
7e7327a1	195	chan_write_failed1(Channel *c)
5260325f	196	{
d7ac5f18	197	debug2("channel %d: write failed", c->self);
5260325f	198	switch (c->ostate) {
8efc0c15	199	case CHAN_OUTPUT_OPEN:
1e5e896c	200	chan_shutdown_write(c);
7e7327a1	201	chan_send_oclose1(c);
368e9dfc	202	chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
8efc0c15	203	break;
8efc0c15	204	case CHAN_OUTPUT_WAIT_DRAIN:
1e5e896c	205	chan_shutdown_write(c);
7e7327a1	206	chan_send_oclose1(c);
368e9dfc	207	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
8efc0c15	208	break;
8efc0c15	209	default:
f048f3e2	210	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	211	c->self, c->ostate);
8efc0c15	212	break;
	213	}
	214	}
70bef40e	215	void
70bef40e	216	chan_obuf_empty(Channel *c)
5260325f	217	{
d7ac5f18	218	debug2("channel %d: obuf empty", c->self);
5260325f	219	if (buffer_len(&c->output)) {
f048f3e2	220	error("channel %d: chan_obuf_empty for non empty buffer",
7e7327a1	221	c->self);
8efc0c15	222	return;
8efc0c15	223	}
5260325f	224	switch (c->ostate) {
8efc0c15	225	case CHAN_OUTPUT_WAIT_DRAIN:
1e5e896c	226	chan_shutdown_write(c);
3057c23b	227	if (!compat20)
3057c23b	228	chan_send_oclose1(c);
368e9dfc	229	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
8efc0c15	230	break;
8efc0c15	231	default:
f048f3e2	232	error("channel %d: internal error: obuf_empty for ostate %d",
7e7327a1	233	c->self, c->ostate);
8efc0c15	234	break;
	235	}
	236	}
8efc0c15	237	static void
7e7327a1	238	chan_send_ieof1(Channel *c)
5260325f	239	{
d7ac5f18	240	debug2("channel %d: send ieof", c->self);
5260325f	241	switch (c->istate) {
8efc0c15	242	case CHAN_INPUT_OPEN:
	243	case CHAN_INPUT_WAIT_DRAIN:
	244	packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
	245	packet_put_int(c->remote_id);
	246	packet_send();
	247	break;
	248	default:
f048f3e2	249	error("channel %d: cannot send ieof for istate %d",
7e7327a1	250	c->self, c->istate);
8efc0c15	251	break;
	252	}
	253	}
	254	static void
7e7327a1	255	chan_send_oclose1(Channel *c)
5260325f	256	{
d7ac5f18	257	debug2("channel %d: send oclose", c->self);
5260325f	258	switch (c->ostate) {
8efc0c15	259	case CHAN_OUTPUT_OPEN:
8efc0c15	260	case CHAN_OUTPUT_WAIT_DRAIN:
9c50edcf	261	buffer_clear(&c->output);
8efc0c15	262	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	263	packet_put_int(c->remote_id);
	264	packet_send();
	265	break;
	266	default:
f048f3e2	267	error("channel %d: cannot send oclose for ostate %d",
184eed6a	268	c->self, c->ostate);
8efc0c15	269	break;
	270	}
	271	}
5260325f	272
7e7327a1	273	/*
	274	* the same for SSH2
	275	*/
8efc0c15	276	static void
668a91b7	277	chan_rcvd_close2(Channel *c)
5260325f	278	{
d7ac5f18	279	debug2("channel %d: rcvd close", c->self);
7e7327a1	280	if (c->flags & CHAN_CLOSE_RCVD)
	281	error("channel %d: protocol error: close rcvd twice", c->self);
	282	c->flags \|= CHAN_CLOSE_RCVD;
	283	if (c->type == SSH_CHANNEL_LARVAL) {
	284	/* tear down larval channels immediately */
368e9dfc	285	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
368e9dfc	286	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	287	return;
	288	}
	289	switch (c->ostate) {
	290	case CHAN_OUTPUT_OPEN:
f048f3e2	291	/*
	292	* wait until a data from the channel is consumed if a CLOSE
	293	* is received
	294	*/
368e9dfc	295	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
7e7327a1	296	break;
	297	}
	298	switch (c->istate) {
	299	case CHAN_INPUT_OPEN:
7e7327a1	300	chan_shutdown_read(c);
668a91b7	301	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	302	break;
7e7327a1	303	case CHAN_INPUT_WAIT_DRAIN:
7e7327a1	304	chan_send_eof2(c);
668a91b7	305	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	306	break;
7e7327a1	307	}
8efc0c15	308	}
8efc0c15	309	static void
668a91b7	310	chan_rcvd_eof2(Channel *c)
5260325f	311	{
d7ac5f18	312	debug2("channel %d: rcvd eof", c->self);
d2296ed7	313	c->flags \|= CHAN_EOF_RCVD;
368e9dfc	314	if (c->ostate == CHAN_OUTPUT_OPEN)
368e9dfc	315	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
8efc0c15	316	}
7e7327a1	317	static void
	318	chan_write_failed2(Channel *c)
	319	{
d7ac5f18	320	debug2("channel %d: write failed", c->self);
7e7327a1	321	switch (c->ostate) {
7e7327a1	322	case CHAN_OUTPUT_OPEN:
7e7327a1	323	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	324	chan_shutdown_write(c);
368e9dfc	325	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
7e7327a1	326	break;
7e7327a1	327	default:
f048f3e2	328	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	329	c->self, c->ostate);
	330	break;
	331	}
	332	}
	333	static void
7e7327a1	334	chan_send_eof2(Channel *c)
7e7327a1	335	{
d7ac5f18	336	debug2("channel %d: send eof", c->self);
7e7327a1	337	switch (c->istate) {
	338	case CHAN_INPUT_WAIT_DRAIN:
	339	packet_start(SSH2_MSG_CHANNEL_EOF);
	340	packet_put_int(c->remote_id);
	341	packet_send();
d2296ed7	342	c->flags \|= CHAN_EOF_SENT;
7e7327a1	343	break;
7e7327a1	344	default:
f048f3e2	345	error("channel %d: cannot send eof for istate %d",
7e7327a1	346	c->self, c->istate);
	347	break;
	348	}
	349	}
	350	static void
	351	chan_send_close2(Channel *c)
	352	{
d7ac5f18	353	debug2("channel %d: send close", c->self);
7e7327a1	354	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
7e7327a1	355	c->istate != CHAN_INPUT_CLOSED) {
f048f3e2	356	error("channel %d: cannot send close for istate/ostate %d/%d",
7e7327a1	357	c->self, c->istate, c->ostate);
7e7327a1	358	} else if (c->flags & CHAN_CLOSE_SENT) {
f048f3e2	359	error("channel %d: already sent close", c->self);
7e7327a1	360	} else {
	361	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	362	packet_put_int(c->remote_id);
	363	packet_send();
	364	c->flags \|= CHAN_CLOSE_SENT;
	365	}
	366	}
ee55dacf	367
	368	/* shared */
	369
70bef40e	370	void
	371	chan_rcvd_ieof(Channel *c)
	372	{
	373	if (compat20)
	374	chan_rcvd_eof2(c);
	375	else
	376	chan_rcvd_ieof1(c);
32e7d71f	377	if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
7203d6bb	378	buffer_len(&c->output) == 0 &&
d2296ed7	379	!CHANNEL_EFD_OUTPUT_ACTIVE(c))
32e7d71f	380	chan_obuf_empty(c);
70bef40e	381	}
	382	void
	383	chan_rcvd_oclose(Channel *c)
	384	{
	385	if (compat20)
	386	chan_rcvd_close2(c);
	387	else
	388	chan_rcvd_oclose1(c);
	389	}
	390	void
	391	chan_write_failed(Channel *c)
	392	{
	393	if (compat20)
	394	chan_write_failed2(c);
	395	else
	396	chan_write_failed1(c);
	397	}
	398
719fc62f	399	void
	400	chan_mark_dead(Channel *c)
	401	{
6fd8622b	402	c->type = SSH_CHANNEL_ZOMBIE;
719fc62f	403	}
719fc62f	404
ee55dacf	405	int
ca75d7de	406	chan_is_dead(Channel *c, int do_send)
5260325f	407	{
6fd8622b	408	if (c->type == SSH_CHANNEL_ZOMBIE) {
d7ac5f18	409	debug2("channel %d: zombie", c->self);
719fc62f	410	return 1;
6fd8622b	411	}
ee55dacf	412	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	413	return 0;
	414	if (!compat20) {
d7ac5f18	415	debug2("channel %d: is dead", c->self);
ee55dacf	416	return 1;
ee55dacf	417	}
d2296ed7	418	if ((datafellows & SSH_BUG_EXTEOF) &&
	419	c->extended_usage == CHAN_EXTENDED_WRITE &&
	420	c->efd != -1 &&
	421	buffer_len(&c->extended) > 0) {
875ec275	422	debug2("channel %d: active efd: %d len %d",
875ec275	423	c->self, c->efd, buffer_len(&c->extended));
d2296ed7	424	return 0;
	425	}
	426	if (!(c->flags & CHAN_CLOSE_SENT)) {
ca75d7de	427	if (do_send) {
d2296ed7	428	chan_send_close2(c);
	429	} else {
	430	/* channel would be dead if we sent a close */
	431	if (c->flags & CHAN_CLOSE_RCVD) {
d7ac5f18	432	debug2("channel %d: almost dead",
d2296ed7	433	c->self);
d2296ed7	434	return 1;
418e724c	435	}
7e7327a1	436	}
d2296ed7	437	}
	438	if ((c->flags & CHAN_CLOSE_SENT) &&
	439	(c->flags & CHAN_CLOSE_RCVD)) {
d7ac5f18	440	debug2("channel %d: is dead", c->self);
d2296ed7	441	return 1;
8efc0c15	442	}
ee55dacf	443	return 0;
8efc0c15	444	}
7e7327a1	445
7e7327a1	446	/* helper */
	447	static void
	448	chan_shutdown_write(Channel *c)
	449	{
9c50edcf	450	buffer_clear(&c->output);
7e7327a1	451	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	452	return;
	453	/* shutdown failure is allowed if write failed already */
d7ac5f18	454	debug2("channel %d: close_write", c->self);
7e7327a1	455	if (c->sock != -1) {
7e7327a1	456	if (shutdown(c->sock, SHUT_WR) < 0)
d7ac5f18	457	debug2("channel %d: chan_shutdown_write: "
f048f3e2	458	"shutdown() failed for fd%d: %.100s",
7e7327a1	459	c->self, c->sock, strerror(errno));
7e7327a1	460	} else {
489aa2e9	461	if (channel_close_fd(&c->wfd) < 0)
bbe88b6d	462	logit("channel %d: chan_shutdown_write: "
f048f3e2	463	"close() failed for fd%d: %.100s",
7e7327a1	464	c->self, c->wfd, strerror(errno));
7e7327a1	465	}
	466	}
	467	static void
	468	chan_shutdown_read(Channel *c)
	469	{
	470	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	471	return;
d7ac5f18	472	debug2("channel %d: close_read", c->self);
7e7327a1	473	if (c->sock != -1) {
2b87da3b	474	/*
47670e77	475	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
47670e77	476	* write side has been closed already. (bug on Linux)
f49df8e9	477	* HP-UX may return ENOTCONN also.
47670e77	478	*/
47670e77	479	if (shutdown(c->sock, SHUT_RD) < 0
f49df8e9	480	&& errno != ENOTCONN)
f048f3e2	481	error("channel %d: chan_shutdown_read: "
	482	"shutdown() failed for fd%d [i%d o%d]: %.100s",
	483	c->self, c->sock, c->istate, c->ostate,
1b73841d	484	strerror(errno));
7e7327a1	485	} else {
489aa2e9	486	if (channel_close_fd(&c->rfd) < 0)
bbe88b6d	487	logit("channel %d: chan_shutdown_read: "
f048f3e2	488	"close() failed for fd%d: %.100s",
7e7327a1	489	c->self, c->rfd, strerror(errno));
7e7327a1	490	}
8efc0c15	491	}