[gssapi-openssh.git] / openssh / nchan.c

/*
 * 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"
RCSID("$OpenBSD: nchan.c,v 1.44 2002/01/21 23:27:10 markus Exp $");

#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);
	debug("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);
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("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)
{
	debug("channel %d: rcvd eof", c->self);
	if (c->ostate == CHAN_OUTPUT_OPEN)
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
}
static void
chan_write_failed2(Channel *c)
{
	debug("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)
{
	debug("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();
		break;
	default:
		error("channel %d: cannot send eof for istate %d",
		    c->self, c->istate);
		break;
	}
}
static void
chan_send_close2(Channel *c)
{
	debug("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)
		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 send)
{
	if (c->type == SSH_CHANNEL_ZOMBIE) {
		debug("channel %d: zombie", c->self);
		return 1;
	}
	if (c->istate != CHAN_INPUT_CLOSED || c->ostate != CHAN_OUTPUT_CLOSED)
		return 0;
	if (!compat20) {
		debug("channel %d: is dead", c->self);
		return 1;
	}
	/*
	 * we have to delay the close message if the efd (for stderr) is
	 * still active
	 */
	if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
	    buffer_len(&c->extended) > 0)
#if 0
	    || ((c->extended_usage == CHAN_EXTENDED_READ) &&
	    c->efd != -1)
#endif
	    ) {
		debug2("channel %d: active efd: %d len %d type %s",
		    c->self, c->efd, buffer_len(&c->extended),
		    c->extended_usage==CHAN_EXTENDED_READ ?
		    "read": "write");
	} else {
		if (!(c->flags & CHAN_CLOSE_SENT)) {
			if (send) {
				chan_send_close2(c);
			} else {
				/* channel would be dead if we sent a close */
				if (c->flags & CHAN_CLOSE_RCVD) {
					debug("channel %d: almost dead",
					    c->self);
					return 1;
				}
			}
		}
		if ((c->flags & CHAN_CLOSE_SENT) &&
		    (c->flags & CHAN_CLOSE_RCVD)) {
			debug("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 */
	debug("channel %d: close_write", c->self);
	if (c->sock != -1) {
		if (shutdown(c->sock, SHUT_WR) < 0)
			debug("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)
			log("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;
	debug("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)
			log("channel %d: chan_shutdown_read: "
			    "close() failed for fd%d: %.100s",
			    c->self, c->rfd, strerror(errno));
	}
}
Commit	Line	Data
3c0ef626	1	/*
e9a17296	2	* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
3c0ef626	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	*
	13	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	15	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	16	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	17	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	18	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	19	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	20	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	21	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	22	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	23	*/
	24
	25	#include "includes.h"
e9a17296	26	RCSID("$OpenBSD: nchan.c,v 1.44 2002/01/21 23:27:10 markus Exp $");
3c0ef626	27
	28	#include "ssh1.h"
	29	#include "ssh2.h"
	30	#include "buffer.h"
	31	#include "packet.h"
	32	#include "channels.h"
	33	#include "compat.h"
	34	#include "log.h"
	35
	36	/*
	37	* SSH Protocol 1.5 aka New Channel Protocol
	38	* Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.
	39	* Written by Markus Friedl in October 1999
	40	*
	41	* Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the
	42	* tear down of channels:
	43	*
	44	* 1.3: strict request-ack-protocol:
	45	* CLOSE ->
	46	* <- CLOSE_CONFIRM
	47	*
	48	* 1.5: uses variations of:
	49	* IEOF ->
	50	* <- OCLOSE
	51	* <- IEOF
	52	* OCLOSE ->
	53	* i.e. both sides have to close the channel
	54	*
	55	* 2.0: the EOF messages are optional
	56	*
	57	* See the debugging output from 'ssh -v' and 'sshd -d' of
	58	* ssh-1.2.27 as an example.
	59	*
	60	*/
	61
	62	/* functions manipulating channel states */
	63	/*
	64	* EVENTS update channel input/output states execute ACTIONS
	65	*/
3c0ef626	66	/*
	67	* ACTIONS: should never update the channel states
	68	*/
	69	static void chan_send_ieof1(Channel *);
	70	static void chan_send_oclose1(Channel *);
	71	static void chan_send_close2(Channel *);
	72	static void chan_send_eof2(Channel *);
	73
	74	/* helper */
	75	static void chan_shutdown_write(Channel *);
	76	static void chan_shutdown_read(Channel *);
	77
e9a17296	78	static char *ostates[] = { "open", "drain", "wait_ieof", "closed" };
	79	static char *istates[] = { "open", "drain", "wait_oclose", "closed" };
	80
	81	static void
	82	chan_set_istate(Channel *c, u_int next)
	83	{
	84	if (c->istate > CHAN_INPUT_CLOSED \|\| next > CHAN_INPUT_CLOSED)
	85	fatal("chan_set_istate: bad state %d -> %d", c->istate, next);
	86	debug("channel %d: input %s -> %s", c->self, istates[c->istate],
	87	istates[next]);
	88	c->istate = next;
	89	}
	90	static void
	91	chan_set_ostate(Channel *c, u_int next)
	92	{
	93	if (c->ostate > CHAN_OUTPUT_CLOSED \|\| next > CHAN_OUTPUT_CLOSED)
	94	fatal("chan_set_ostate: bad state %d -> %d", c->ostate, next);
	95	debug("channel %d: output %s -> %s", c->self, ostates[c->ostate],
	96	ostates[next]);
	97	c->ostate = next;
	98	}
	99
3c0ef626	100	/*
	101	* SSH1 specific implementation of event functions
	102	*/
	103
	104	static void
	105	chan_rcvd_oclose1(Channel *c)
	106	{
	107	debug("channel %d: rcvd oclose", c->self);
	108	switch (c->istate) {
	109	case CHAN_INPUT_WAIT_OCLOSE:
e9a17296	110	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	111	break;
3c0ef626	112	case CHAN_INPUT_OPEN:
3c0ef626	113	chan_shutdown_read(c);
3c0ef626	114	chan_send_ieof1(c);
e9a17296	115	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	116	break;
	117	case CHAN_INPUT_WAIT_DRAIN:
	118	/* both local read_failed and remote write_failed */
3c0ef626	119	chan_send_ieof1(c);
e9a17296	120	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	121	break;
	122	default:
	123	error("channel %d: protocol error: rcvd_oclose for istate %d",
	124	c->self, c->istate);
	125	return;
	126	}
	127	}
e9a17296	128	void
e9a17296	129	chan_read_failed(Channel *c)
3c0ef626	130	{
	131	debug("channel %d: read failed", c->self);
	132	switch (c->istate) {
	133	case CHAN_INPUT_OPEN:
3c0ef626	134	chan_shutdown_read(c);
e9a17296	135	chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
3c0ef626	136	break;
	137	default:
	138	error("channel %d: chan_read_failed for istate %d",
	139	c->self, c->istate);
	140	break;
	141	}
	142	}
e9a17296	143	void
e9a17296	144	chan_ibuf_empty(Channel *c)
3c0ef626	145	{
	146	debug("channel %d: ibuf empty", c->self);
	147	if (buffer_len(&c->input)) {
	148	error("channel %d: chan_ibuf_empty for non empty buffer",
	149	c->self);
	150	return;
	151	}
	152	switch (c->istate) {
	153	case CHAN_INPUT_WAIT_DRAIN:
e9a17296	154	if (compat20) {
	155	if (!(c->flags & CHAN_CLOSE_SENT))
	156	chan_send_eof2(c);
	157	chan_set_istate(c, CHAN_INPUT_CLOSED);
	158	} else {
	159	chan_send_ieof1(c);
	160	chan_set_istate(c, CHAN_INPUT_WAIT_OCLOSE);
	161	}
3c0ef626	162	break;
	163	default:
	164	error("channel %d: chan_ibuf_empty for istate %d",
	165	c->self, c->istate);
	166	break;
	167	}
	168	}
	169	static void
	170	chan_rcvd_ieof1(Channel *c)
	171	{
	172	debug("channel %d: rcvd ieof", c->self);
3c0ef626	173	switch (c->ostate) {
3c0ef626	174	case CHAN_OUTPUT_OPEN:
e9a17296	175	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
3c0ef626	176	break;
3c0ef626	177	case CHAN_OUTPUT_WAIT_IEOF:
e9a17296	178	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	179	break;
	180	default:
	181	error("channel %d: protocol error: rcvd_ieof for ostate %d",
	182	c->self, c->ostate);
	183	break;
	184	}
	185	}
	186	static void
	187	chan_write_failed1(Channel *c)
	188	{
	189	debug("channel %d: write failed", c->self);
	190	switch (c->ostate) {
	191	case CHAN_OUTPUT_OPEN:
e9a17296	192	chan_shutdown_write(c);
3c0ef626	193	chan_send_oclose1(c);
e9a17296	194	chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
3c0ef626	195	break;
3c0ef626	196	case CHAN_OUTPUT_WAIT_DRAIN:
e9a17296	197	chan_shutdown_write(c);
3c0ef626	198	chan_send_oclose1(c);
e9a17296	199	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	200	break;
	201	default:
	202	error("channel %d: chan_write_failed for ostate %d",
	203	c->self, c->ostate);
	204	break;
	205	}
	206	}
e9a17296	207	void
e9a17296	208	chan_obuf_empty(Channel *c)
3c0ef626	209	{
	210	debug("channel %d: obuf empty", c->self);
	211	if (buffer_len(&c->output)) {
	212	error("channel %d: chan_obuf_empty for non empty buffer",
	213	c->self);
	214	return;
	215	}
	216	switch (c->ostate) {
	217	case CHAN_OUTPUT_WAIT_DRAIN:
e9a17296	218	chan_shutdown_write(c);
	219	if (!compat20)
	220	chan_send_oclose1(c);
	221	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	222	break;
	223	default:
	224	error("channel %d: internal error: obuf_empty for ostate %d",
	225	c->self, c->ostate);
	226	break;
	227	}
	228	}
	229	static void
	230	chan_send_ieof1(Channel *c)
	231	{
	232	debug("channel %d: send ieof", c->self);
	233	switch (c->istate) {
	234	case CHAN_INPUT_OPEN:
	235	case CHAN_INPUT_WAIT_DRAIN:
	236	packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
	237	packet_put_int(c->remote_id);
	238	packet_send();
	239	break;
	240	default:
	241	error("channel %d: cannot send ieof for istate %d",
	242	c->self, c->istate);
	243	break;
	244	}
	245	}
	246	static void
	247	chan_send_oclose1(Channel *c)
	248	{
	249	debug("channel %d: send oclose", c->self);
	250	switch (c->ostate) {
	251	case CHAN_OUTPUT_OPEN:
	252	case CHAN_OUTPUT_WAIT_DRAIN:
e9a17296	253	buffer_clear(&c->output);
3c0ef626	254	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	255	packet_put_int(c->remote_id);
	256	packet_send();
	257	break;
	258	default:
	259	error("channel %d: cannot send oclose for ostate %d",
e9a17296	260	c->self, c->ostate);
3c0ef626	261	break;
	262	}
	263	}
	264
	265	/*
	266	* the same for SSH2
	267	*/
	268	static void
e9a17296	269	chan_rcvd_close2(Channel *c)
3c0ef626	270	{
	271	debug("channel %d: rcvd close", c->self);
	272	if (c->flags & CHAN_CLOSE_RCVD)
	273	error("channel %d: protocol error: close rcvd twice", c->self);
	274	c->flags \|= CHAN_CLOSE_RCVD;
	275	if (c->type == SSH_CHANNEL_LARVAL) {
	276	/* tear down larval channels immediately */
e9a17296	277	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
e9a17296	278	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	279	return;
	280	}
	281	switch (c->ostate) {
	282	case CHAN_OUTPUT_OPEN:
	283	/*
	284	* wait until a data from the channel is consumed if a CLOSE
	285	* is received
	286	*/
e9a17296	287	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
3c0ef626	288	break;
	289	}
	290	switch (c->istate) {
	291	case CHAN_INPUT_OPEN:
3c0ef626	292	chan_shutdown_read(c);
e9a17296	293	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	294	break;
3c0ef626	295	case CHAN_INPUT_WAIT_DRAIN:
3c0ef626	296	chan_send_eof2(c);
e9a17296	297	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	298	break;
	299	}
	300	}
	301	static void
e9a17296	302	chan_rcvd_eof2(Channel *c)
3c0ef626	303	{
3c0ef626	304	debug("channel %d: rcvd eof", c->self);
e9a17296	305	if (c->ostate == CHAN_OUTPUT_OPEN)
e9a17296	306	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
3c0ef626	307	}
	308	static void
	309	chan_write_failed2(Channel *c)
	310	{
	311	debug("channel %d: write failed", c->self);
	312	switch (c->ostate) {
	313	case CHAN_OUTPUT_OPEN:
3c0ef626	314	case CHAN_OUTPUT_WAIT_DRAIN:
3c0ef626	315	chan_shutdown_write(c);
e9a17296	316	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	317	break;
	318	default:
	319	error("channel %d: chan_write_failed for ostate %d",
	320	c->self, c->ostate);
	321	break;
	322	}
	323	}
	324	static void
3c0ef626	325	chan_send_eof2(Channel *c)
	326	{
	327	debug("channel %d: send eof", c->self);
	328	switch (c->istate) {
	329	case CHAN_INPUT_WAIT_DRAIN:
	330	packet_start(SSH2_MSG_CHANNEL_EOF);
	331	packet_put_int(c->remote_id);
	332	packet_send();
	333	break;
	334	default:
	335	error("channel %d: cannot send eof for istate %d",
	336	c->self, c->istate);
	337	break;
	338	}
	339	}
	340	static void
	341	chan_send_close2(Channel *c)
	342	{
	343	debug("channel %d: send close", c->self);
	344	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
	345	c->istate != CHAN_INPUT_CLOSED) {
	346	error("channel %d: cannot send close for istate/ostate %d/%d",
	347	c->self, c->istate, c->ostate);
	348	} else if (c->flags & CHAN_CLOSE_SENT) {
	349	error("channel %d: already sent close", c->self);
	350	} else {
	351	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	352	packet_put_int(c->remote_id);
	353	packet_send();
	354	c->flags \|= CHAN_CLOSE_SENT;
	355	}
	356	}
	357
	358	/* shared */
	359
e9a17296	360	void
	361	chan_rcvd_ieof(Channel *c)
	362	{
	363	if (compat20)
	364	chan_rcvd_eof2(c);
	365	else
	366	chan_rcvd_ieof1(c);
	367	if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
	368	buffer_len(&c->output) == 0)
	369	chan_obuf_empty(c);
	370	}
	371	void
	372	chan_rcvd_oclose(Channel *c)
	373	{
	374	if (compat20)
	375	chan_rcvd_close2(c);
	376	else
	377	chan_rcvd_oclose1(c);
	378	}
	379	void
	380	chan_write_failed(Channel *c)
	381	{
	382	if (compat20)
	383	chan_write_failed2(c);
	384	else
	385	chan_write_failed1(c);
	386	}
	387
3c0ef626	388	void
	389	chan_mark_dead(Channel *c)
	390	{
	391	c->type = SSH_CHANNEL_ZOMBIE;
	392	}
	393
	394	int
	395	chan_is_dead(Channel *c, int send)
	396	{
	397	if (c->type == SSH_CHANNEL_ZOMBIE) {
	398	debug("channel %d: zombie", c->self);
	399	return 1;
	400	}
	401	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	402	return 0;
	403	if (!compat20) {
	404	debug("channel %d: is dead", c->self);
	405	return 1;
	406	}
	407	/*
	408	* we have to delay the close message if the efd (for stderr) is
	409	* still active
	410	*/
	411	if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
	412	buffer_len(&c->extended) > 0)
	413	#if 0
	414	\|\| ((c->extended_usage == CHAN_EXTENDED_READ) &&
	415	c->efd != -1)
	416	#endif
	417	) {
	418	debug2("channel %d: active efd: %d len %d type %s",
	419	c->self, c->efd, buffer_len(&c->extended),
	420	c->extended_usage==CHAN_EXTENDED_READ ?
e9a17296	421	"read": "write");
3c0ef626	422	} else {
	423	if (!(c->flags & CHAN_CLOSE_SENT)) {
	424	if (send) {
	425	chan_send_close2(c);
	426	} else {
	427	/* channel would be dead if we sent a close */
	428	if (c->flags & CHAN_CLOSE_RCVD) {
	429	debug("channel %d: almost dead",
	430	c->self);
	431	return 1;
	432	}
	433	}
	434	}
	435	if ((c->flags & CHAN_CLOSE_SENT) &&
	436	(c->flags & CHAN_CLOSE_RCVD)) {
	437	debug("channel %d: is dead", c->self);
	438	return 1;
	439	}
	440	}
	441	return 0;
	442	}
	443
3c0ef626	444	/* helper */
	445	static void
	446	chan_shutdown_write(Channel *c)
	447	{
e9a17296	448	buffer_clear(&c->output);
3c0ef626	449	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	450	return;
	451	/* shutdown failure is allowed if write failed already */
	452	debug("channel %d: close_write", c->self);
	453	if (c->sock != -1) {
	454	if (shutdown(c->sock, SHUT_WR) < 0)
	455	debug("channel %d: chan_shutdown_write: "
	456	"shutdown() failed for fd%d: %.100s",
	457	c->self, c->sock, strerror(errno));
	458	} else {
	459	if (channel_close_fd(&c->wfd) < 0)
	460	log("channel %d: chan_shutdown_write: "
	461	"close() failed for fd%d: %.100s",
	462	c->self, c->wfd, strerror(errno));
	463	}
	464	}
	465	static void
	466	chan_shutdown_read(Channel *c)
	467	{
	468	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	469	return;
	470	debug("channel %d: close_read", c->self);
	471	if (c->sock != -1) {
	472	/*
	473	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
	474	* write side has been closed already. (bug on Linux)
	475	* HP-UX may return ENOTCONN also.
	476	*/
	477	if (shutdown(c->sock, SHUT_RD) < 0
	478	&& errno != ENOTCONN)
	479	error("channel %d: chan_shutdown_read: "
	480	"shutdown() failed for fd%d [i%d o%d]: %.100s",
	481	c->self, c->sock, c->istate, c->ostate,
	482	strerror(errno));
	483	} else {
	484	if (channel_close_fd(&c->rfd) < 0)
	485	log("channel %d: chan_shutdown_read: "
	486	"close() failed for fd%d: %.100s",
	487	c->self, c->rfd, strerror(errno));
	488	}
	489	}