[openssh.git] / nchan.c

/*
 * Copyright (c) 1999 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 1.28 2001/05/31 10:30:16 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
 */
/* events concerning the INPUT from socket for channel (istate) */
chan_event_fn *chan_rcvd_oclose			= NULL;
chan_event_fn *chan_read_failed			= NULL;
chan_event_fn *chan_ibuf_empty			= NULL;
/* events concerning the OUTPUT from channel for socket (ostate) */
chan_event_fn *chan_rcvd_ieof			= NULL;
chan_event_fn *chan_write_failed		= NULL;
chan_event_fn *chan_obuf_empty			= NULL;
/*
 * ACTIONS: should never update the channel states
 */
static void	chan_send_ieof1(Channel *c);
static void	chan_send_oclose1(Channel *c);
static void	chan_send_close2(Channel *c);
static void	chan_send_eof2(Channel *c);

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

/*
 * 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:
		debug("channel %d: input wait_oclose -> closed", c->self);
		c->istate = CHAN_INPUT_CLOSED;
		break;
	case CHAN_INPUT_OPEN:
		debug("channel %d: input open -> closed", c->self);
		chan_shutdown_read(c);
		chan_send_ieof1(c);
		c->istate = CHAN_INPUT_CLOSED;
		break;
	case CHAN_INPUT_WAIT_DRAIN:
		/* both local read_failed and remote write_failed  */
		log("channel %d: input drain -> closed", c->self);
		chan_send_ieof1(c);
		c->istate = CHAN_INPUT_CLOSED;
		break;
	default:
		error("channel %d: protocol error: rcvd_oclose for istate %d",
		    c->self, c->istate);
		return;
	}
}
static void
chan_read_failed_12(Channel *c)
{
	debug("channel %d: read failed", c->self);
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		debug("channel %d: input open -> drain", c->self);
		chan_shutdown_read(c);
		c->istate = CHAN_INPUT_WAIT_DRAIN;
#if 0
		if (buffer_len(&c->input) == 0) {
			debug("channel %d: input: no drain shortcut", c->self);
			chan_ibuf_empty(c);
		}
#endif
		break;
	default:
		error("channel %d: chan_read_failed for istate %d",
		    c->self, c->istate);
		break;
	}
}
static void
chan_ibuf_empty1(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:
		debug("channel %d: input drain -> wait_oclose", c->self);
		chan_send_ieof1(c);
		c->istate = 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);
	if (c->type != SSH_CHANNEL_OPEN) {
		debug("channel %d: non-open", c->self);
		if (c->istate == CHAN_INPUT_OPEN) {
			debug("channel %d: non-open: input open -> wait_oclose",
			    c->self);
			chan_shutdown_read(c);
			chan_send_ieof1(c);
			c->istate = CHAN_INPUT_WAIT_OCLOSE;
		} else {
			error("channel %d: non-open: istate %d != open",
			    c->self, c->istate);
		}
		if (c->ostate == CHAN_OUTPUT_OPEN) {
			debug("channel %d: non-open: output open -> closed",
			    c->self);
			chan_send_oclose1(c);
			c->ostate = CHAN_OUTPUT_CLOSED;
		} else {
			error("channel %d: non-open: ostate %d != open",
			    c->self, c->ostate);
		}
		return;
	}
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		debug("channel %d: output open -> drain", c->self);
		c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
		break;
	case CHAN_OUTPUT_WAIT_IEOF:
		debug("channel %d: output wait_ieof -> closed", c->self);
		c->ostate = 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:
		debug("channel %d: output open -> wait_ieof", c->self);
		chan_send_oclose1(c);
		c->ostate = CHAN_OUTPUT_WAIT_IEOF;
		break;
	case CHAN_OUTPUT_WAIT_DRAIN:
		debug("channel %d: output wait_drain -> closed", c->self);
		chan_send_oclose1(c);
		c->ostate = CHAN_OUTPUT_CLOSED;
		break;
	default:
		error("channel %d: chan_write_failed for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
static void
chan_obuf_empty1(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:
		debug("channel %d: output drain -> closed", c->self);
		chan_send_oclose1(c);
		c->ostate = 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:
		chan_shutdown_write(c);
		buffer_consume(&c->output, buffer_len(&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_oclose2(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 */
		c->ostate = CHAN_OUTPUT_CLOSED;
		c->istate = 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
		 */
		debug("channel %d: output open -> drain", c->self);
		c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
		break;
	}
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		debug("channel %d: input open -> closed", c->self);
		chan_shutdown_read(c);
		break;
	case CHAN_INPUT_WAIT_DRAIN:
		debug("channel %d: input drain -> closed", c->self);
		chan_send_eof2(c);
		break;
	}
	c->istate = CHAN_INPUT_CLOSED;
}
static void
chan_ibuf_empty2(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:
		debug("channel %d: input drain -> closed", c->self);
		if (!(c->flags & CHAN_CLOSE_SENT))
			chan_send_eof2(c);
		c->istate = CHAN_INPUT_CLOSED;
		break;
	default:
		error("channel %d: chan_ibuf_empty for istate %d",
		     c->self, c->istate);
		break;
	}
}
static void
chan_rcvd_ieof2(Channel *c)
{
	debug("channel %d: rcvd eof", c->self);
	if (c->ostate == CHAN_OUTPUT_OPEN) {
		debug("channel %d: output open -> drain", c->self);
		c->ostate = 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:
		debug("channel %d: output open -> closed", c->self);
		chan_shutdown_write(c); /* ?? */
		c->ostate = CHAN_OUTPUT_CLOSED;
		break;
	case CHAN_OUTPUT_WAIT_DRAIN:
		debug("channel %d: output drain -> closed", c->self);
		chan_shutdown_write(c);
		c->ostate = CHAN_OUTPUT_CLOSED;
		break;
	default:
		error("channel %d: chan_write_failed for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
static void
chan_obuf_empty2(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:
		debug("channel %d: output drain -> closed", c->self);
		chan_shutdown_write(c);
		c->ostate = CHAN_OUTPUT_CLOSED;
		break;
	default:
		error("channel %d: chan_obuf_empty 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_mark_dead(Channel *c)
{
	c->type = SSH_CHANNEL_ZOMBIE;
}

int
chan_is_dead(Channel *c)
{
	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)) {
			chan_send_close2(c);
		}
		if ((c->flags & CHAN_CLOSE_SENT) &&
		    (c->flags & CHAN_CLOSE_RCVD)) {
			debug("channel %d: is dead", c->self);
			return 1;
		}
	}
	return 0;
}

void
chan_init_iostates(Channel *c)
{
	c->ostate = CHAN_OUTPUT_OPEN;
	c->istate = CHAN_INPUT_OPEN;
	c->flags = 0;
}

/* init */
void
chan_init(void)
{
	if (compat20) {
		chan_rcvd_oclose		= chan_rcvd_oclose2;
		chan_read_failed		= chan_read_failed_12;
		chan_ibuf_empty			= chan_ibuf_empty2;

		chan_rcvd_ieof			= chan_rcvd_ieof2;
		chan_write_failed		= chan_write_failed2;
		chan_obuf_empty			= chan_obuf_empty2;
	} else {
		chan_rcvd_oclose		= chan_rcvd_oclose1;
		chan_read_failed		= chan_read_failed_12;
		chan_ibuf_empty			= chan_ibuf_empty1;

		chan_rcvd_ieof			= chan_rcvd_ieof1;
		chan_write_failed		= chan_write_failed1;
		chan_obuf_empty			= chan_obuf_empty1;
	}
}

/* helper */
static void
chan_shutdown_write(Channel *c)
{
	buffer_consume(&c->output, buffer_len(&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 (close(c->wfd) < 0)
			log("channel %d: chan_shutdown_write: "
			    "close() failed for fd%d: %.100s",
			    c->self, c->wfd, strerror(errno));
		c->wfd = -1;
	}
}
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 will return EINVAL.
		 */
		if (shutdown(c->sock, SHUT_RD) < 0
		    && (errno != ENOTCONN && errno != EINVAL))
			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 (close(c->rfd) < 0)
			log("channel %d: chan_shutdown_read: "
			    "close() failed for fd%d: %.100s",
			    c->self, c->rfd, strerror(errno));
		c->rfd = -1;
	}
}
Commit	Line	Data
aa3378df	1	/*
	2	* Copyright (c) 1999 Markus Friedl. All rights reserved.
	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.
aa3378df	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
8efc0c15	25	#include "includes.h"
33e6bb95	26	RCSID("$OpenBSD: nchan.c,v 1.28 2001/05/31 10:30:16 markus Exp $");
8efc0c15	27
42f11eb2	28	#include "ssh1.h"
42f11eb2	29	#include "ssh2.h"
8efc0c15	30	#include "buffer.h"
	31	#include "packet.h"
	32	#include "channels.h"
7e7327a1	33	#include "compat.h"
42f11eb2	34	#include "log.h"
8efc0c15	35
f048f3e2	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
7e7327a1	62	/* functions manipulating channel states */
8efc0c15	63	/*
5260325f	64	* EVENTS update channel input/output states execute ACTIONS
8efc0c15	65	*/
8efc0c15	66	/* events concerning the INPUT from socket for channel (istate) */
7e7327a1	67	chan_event_fn *chan_rcvd_oclose = NULL;
	68	chan_event_fn *chan_read_failed = NULL;
	69	chan_event_fn *chan_ibuf_empty = NULL;
	70	/* events concerning the OUTPUT from channel for socket (ostate) */
	71	chan_event_fn *chan_rcvd_ieof = NULL;
	72	chan_event_fn *chan_write_failed = NULL;
	73	chan_event_fn *chan_obuf_empty = NULL;
	74	/*
	75	* ACTIONS: should never update the channel states
	76	*/
	77	static void chan_send_ieof1(Channel *c);
	78	static void chan_send_oclose1(Channel *c);
	79	static void chan_send_close2(Channel *c);
	80	static void chan_send_eof2(Channel *c);
	81
7e7327a1	82	/* helper */
	83	static void chan_shutdown_write(Channel *c);
	84	static void chan_shutdown_read(Channel *c);
	85
	86	/*
	87	* SSH1 specific implementation of event functions
	88	*/
	89
	90	static void
	91	chan_rcvd_oclose1(Channel *c)
5260325f	92	{
7e7327a1	93	debug("channel %d: rcvd oclose", c->self);
5260325f	94	switch (c->istate) {
8efc0c15	95	case CHAN_INPUT_WAIT_OCLOSE:
7e7327a1	96	debug("channel %d: input wait_oclose -> closed", c->self);
5260325f	97	c->istate = CHAN_INPUT_CLOSED;
8efc0c15	98	break;
8efc0c15	99	case CHAN_INPUT_OPEN:
7e7327a1	100	debug("channel %d: input open -> closed", c->self);
8efc0c15	101	chan_shutdown_read(c);
7e7327a1	102	chan_send_ieof1(c);
5260325f	103	c->istate = CHAN_INPUT_CLOSED;
48e671d5	104	break;
	105	case CHAN_INPUT_WAIT_DRAIN:
	106	/* both local read_failed and remote write_failed */
7e7327a1	107	log("channel %d: input drain -> closed", c->self);
7e7327a1	108	chan_send_ieof1(c);
48e671d5	109	c->istate = CHAN_INPUT_CLOSED;
8efc0c15	110	break;
8efc0c15	111	default:
f048f3e2	112	error("channel %d: protocol error: rcvd_oclose for istate %d",
7e7327a1	113	c->self, c->istate);
48e671d5	114	return;
8efc0c15	115	}
8efc0c15	116	}
7e7327a1	117	static void
7e7327a1	118	chan_read_failed_12(Channel *c)
5260325f	119	{
7e7327a1	120	debug("channel %d: read failed", c->self);
5260325f	121	switch (c->istate) {
8efc0c15	122	case CHAN_INPUT_OPEN:
7e7327a1	123	debug("channel %d: input open -> drain", c->self);
8efc0c15	124	chan_shutdown_read(c);
5260325f	125	c->istate = CHAN_INPUT_WAIT_DRAIN;
f048f3e2	126	#if 0
d0c832f3	127	if (buffer_len(&c->input) == 0) {
	128	debug("channel %d: input: no drain shortcut", c->self);
	129	chan_ibuf_empty(c);
	130	}
f048f3e2	131	#endif
8efc0c15	132	break;
8efc0c15	133	default:
f048f3e2	134	error("channel %d: chan_read_failed for istate %d",
7e7327a1	135	c->self, c->istate);
8efc0c15	136	break;
	137	}
	138	}
7e7327a1	139	static void
7e7327a1	140	chan_ibuf_empty1(Channel *c)
5260325f	141	{
7e7327a1	142	debug("channel %d: ibuf empty", c->self);
5260325f	143	if (buffer_len(&c->input)) {
f048f3e2	144	error("channel %d: chan_ibuf_empty for non empty buffer",
7e7327a1	145	c->self);
8efc0c15	146	return;
8efc0c15	147	}
5260325f	148	switch (c->istate) {
8efc0c15	149	case CHAN_INPUT_WAIT_DRAIN:
7e7327a1	150	debug("channel %d: input drain -> wait_oclose", c->self);
7e7327a1	151	chan_send_ieof1(c);
5260325f	152	c->istate = CHAN_INPUT_WAIT_OCLOSE;
8efc0c15	153	break;
8efc0c15	154	default:
f048f3e2	155	error("channel %d: chan_ibuf_empty for istate %d",
7e7327a1	156	c->self, c->istate);
8efc0c15	157	break;
	158	}
	159	}
7e7327a1	160	static void
7e7327a1	161	chan_rcvd_ieof1(Channel *c)
5260325f	162	{
7e7327a1	163	debug("channel %d: rcvd ieof", c->self);
1d1ffb87	164	if (c->type != SSH_CHANNEL_OPEN) {
	165	debug("channel %d: non-open", c->self);
	166	if (c->istate == CHAN_INPUT_OPEN) {
f048f3e2	167	debug("channel %d: non-open: input open -> wait_oclose",
f048f3e2	168	c->self);
1d1ffb87	169	chan_shutdown_read(c);
	170	chan_send_ieof1(c);
	171	c->istate = CHAN_INPUT_WAIT_OCLOSE;
	172	} else {
f048f3e2	173	error("channel %d: non-open: istate %d != open",
f048f3e2	174	c->self, c->istate);
1d1ffb87	175	}
1d1ffb87	176	if (c->ostate == CHAN_OUTPUT_OPEN) {
f048f3e2	177	debug("channel %d: non-open: output open -> closed",
f048f3e2	178	c->self);
1d1ffb87	179	chan_send_oclose1(c);
	180	c->ostate = CHAN_OUTPUT_CLOSED;
	181	} else {
f048f3e2	182	error("channel %d: non-open: ostate %d != open",
f048f3e2	183	c->self, c->ostate);
1d1ffb87	184	}
	185	return;
	186	}
5260325f	187	switch (c->ostate) {
8efc0c15	188	case CHAN_OUTPUT_OPEN:
7e7327a1	189	debug("channel %d: output open -> drain", c->self);
5260325f	190	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
8efc0c15	191	break;
8efc0c15	192	case CHAN_OUTPUT_WAIT_IEOF:
7e7327a1	193	debug("channel %d: output wait_ieof -> closed", c->self);
5260325f	194	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	195	break;
8efc0c15	196	default:
f048f3e2	197	error("channel %d: protocol error: rcvd_ieof for ostate %d",
7e7327a1	198	c->self, c->ostate);
8efc0c15	199	break;
	200	}
	201	}
7e7327a1	202	static void
7e7327a1	203	chan_write_failed1(Channel *c)
5260325f	204	{
7e7327a1	205	debug("channel %d: write failed", c->self);
5260325f	206	switch (c->ostate) {
8efc0c15	207	case CHAN_OUTPUT_OPEN:
7e7327a1	208	debug("channel %d: output open -> wait_ieof", c->self);
7e7327a1	209	chan_send_oclose1(c);
5260325f	210	c->ostate = CHAN_OUTPUT_WAIT_IEOF;
8efc0c15	211	break;
8efc0c15	212	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	213	debug("channel %d: output wait_drain -> closed", c->self);
7e7327a1	214	chan_send_oclose1(c);
5260325f	215	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	216	break;
8efc0c15	217	default:
f048f3e2	218	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	219	c->self, c->ostate);
8efc0c15	220	break;
	221	}
	222	}
7e7327a1	223	static void
7e7327a1	224	chan_obuf_empty1(Channel *c)
5260325f	225	{
7e7327a1	226	debug("channel %d: obuf empty", c->self);
5260325f	227	if (buffer_len(&c->output)) {
f048f3e2	228	error("channel %d: chan_obuf_empty for non empty buffer",
7e7327a1	229	c->self);
8efc0c15	230	return;
8efc0c15	231	}
5260325f	232	switch (c->ostate) {
8efc0c15	233	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	234	debug("channel %d: output drain -> closed", c->self);
7e7327a1	235	chan_send_oclose1(c);
5260325f	236	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	237	break;
8efc0c15	238	default:
f048f3e2	239	error("channel %d: internal error: obuf_empty for ostate %d",
7e7327a1	240	c->self, c->ostate);
8efc0c15	241	break;
	242	}
	243	}
8efc0c15	244	static void
7e7327a1	245	chan_send_ieof1(Channel *c)
5260325f	246	{
7e7327a1	247	debug("channel %d: send ieof", c->self);
5260325f	248	switch (c->istate) {
8efc0c15	249	case CHAN_INPUT_OPEN:
	250	case CHAN_INPUT_WAIT_DRAIN:
	251	packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
	252	packet_put_int(c->remote_id);
	253	packet_send();
	254	break;
	255	default:
f048f3e2	256	error("channel %d: cannot send ieof for istate %d",
7e7327a1	257	c->self, c->istate);
8efc0c15	258	break;
	259	}
	260	}
	261	static void
7e7327a1	262	chan_send_oclose1(Channel *c)
5260325f	263	{
7e7327a1	264	debug("channel %d: send oclose", c->self);
5260325f	265	switch (c->ostate) {
8efc0c15	266	case CHAN_OUTPUT_OPEN:
	267	case CHAN_OUTPUT_WAIT_DRAIN:
	268	chan_shutdown_write(c);
	269	buffer_consume(&c->output, buffer_len(&c->output));
	270	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	271	packet_put_int(c->remote_id);
	272	packet_send();
	273	break;
	274	default:
f048f3e2	275	error("channel %d: cannot send oclose for ostate %d",
7e7327a1	276	c->self, c->ostate);
8efc0c15	277	break;
	278	}
	279	}
5260325f	280
7e7327a1	281	/*
	282	* the same for SSH2
	283	*/
8efc0c15	284	static void
7e7327a1	285	chan_rcvd_oclose2(Channel *c)
5260325f	286	{
7e7327a1	287	debug("channel %d: rcvd close", c->self);
	288	if (c->flags & CHAN_CLOSE_RCVD)
	289	error("channel %d: protocol error: close rcvd twice", c->self);
	290	c->flags \|= CHAN_CLOSE_RCVD;
	291	if (c->type == SSH_CHANNEL_LARVAL) {
	292	/* tear down larval channels immediately */
	293	c->ostate = CHAN_OUTPUT_CLOSED;
	294	c->istate = CHAN_INPUT_CLOSED;
	295	return;
	296	}
	297	switch (c->ostate) {
	298	case CHAN_OUTPUT_OPEN:
f048f3e2	299	/*
	300	* wait until a data from the channel is consumed if a CLOSE
	301	* is received
	302	*/
7e7327a1	303	debug("channel %d: output open -> drain", c->self);
	304	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
	305	break;
	306	}
	307	switch (c->istate) {
	308	case CHAN_INPUT_OPEN:
	309	debug("channel %d: input open -> closed", c->self);
	310	chan_shutdown_read(c);
	311	break;
	312	case CHAN_INPUT_WAIT_DRAIN:
	313	debug("channel %d: input drain -> closed", c->self);
	314	chan_send_eof2(c);
	315	break;
	316	}
	317	c->istate = CHAN_INPUT_CLOSED;
8efc0c15	318	}
8efc0c15	319	static void
7e7327a1	320	chan_ibuf_empty2(Channel *c)
	321	{
	322	debug("channel %d: ibuf empty", c->self);
	323	if (buffer_len(&c->input)) {
f048f3e2	324	error("channel %d: chan_ibuf_empty for non empty buffer",
7e7327a1	325	c->self);
	326	return;
	327	}
	328	switch (c->istate) {
	329	case CHAN_INPUT_WAIT_DRAIN:
	330	debug("channel %d: input drain -> closed", c->self);
	331	if (!(c->flags & CHAN_CLOSE_SENT))
	332	chan_send_eof2(c);
	333	c->istate = CHAN_INPUT_CLOSED;
	334	break;
	335	default:
f048f3e2	336	error("channel %d: chan_ibuf_empty for istate %d",
7e7327a1	337	c->self, c->istate);
	338	break;
	339	}
	340	}
	341	static void
	342	chan_rcvd_ieof2(Channel *c)
5260325f	343	{
7e7327a1	344	debug("channel %d: rcvd eof", c->self);
	345	if (c->ostate == CHAN_OUTPUT_OPEN) {
	346	debug("channel %d: output open -> drain", c->self);
	347	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
	348	}
8efc0c15	349	}
7e7327a1	350	static void
	351	chan_write_failed2(Channel *c)
	352	{
	353	debug("channel %d: write failed", c->self);
	354	switch (c->ostate) {
	355	case CHAN_OUTPUT_OPEN:
	356	debug("channel %d: output open -> closed", c->self);
1d1ffb87	357	chan_shutdown_write(c); /* ?? */
7e7327a1	358	c->ostate = CHAN_OUTPUT_CLOSED;
	359	break;
	360	case CHAN_OUTPUT_WAIT_DRAIN:
	361	debug("channel %d: output drain -> closed", c->self);
	362	chan_shutdown_write(c);
	363	c->ostate = CHAN_OUTPUT_CLOSED;
	364	break;
	365	default:
f048f3e2	366	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	367	c->self, c->ostate);
	368	break;
	369	}
	370	}
	371	static void
	372	chan_obuf_empty2(Channel *c)
	373	{
	374	debug("channel %d: obuf empty", c->self);
	375	if (buffer_len(&c->output)) {
f048f3e2	376	error("channel %d: chan_obuf_empty for non empty buffer",
7e7327a1	377	c->self);
	378	return;
	379	}
	380	switch (c->ostate) {
	381	case CHAN_OUTPUT_WAIT_DRAIN:
	382	debug("channel %d: output drain -> closed", c->self);
	383	chan_shutdown_write(c);
	384	c->ostate = CHAN_OUTPUT_CLOSED;
	385	break;
	386	default:
f048f3e2	387	error("channel %d: chan_obuf_empty for ostate %d",
7e7327a1	388	c->self, c->ostate);
	389	break;
	390	}
	391	}
	392	static void
	393	chan_send_eof2(Channel *c)
	394	{
	395	debug("channel %d: send eof", c->self);
	396	switch (c->istate) {
	397	case CHAN_INPUT_WAIT_DRAIN:
	398	packet_start(SSH2_MSG_CHANNEL_EOF);
	399	packet_put_int(c->remote_id);
	400	packet_send();
	401	break;
	402	default:
f048f3e2	403	error("channel %d: cannot send eof for istate %d",
7e7327a1	404	c->self, c->istate);
	405	break;
	406	}
	407	}
	408	static void
	409	chan_send_close2(Channel *c)
	410	{
	411	debug("channel %d: send close", c->self);
	412	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
	413	c->istate != CHAN_INPUT_CLOSED) {
f048f3e2	414	error("channel %d: cannot send close for istate/ostate %d/%d",
7e7327a1	415	c->self, c->istate, c->ostate);
7e7327a1	416	} else if (c->flags & CHAN_CLOSE_SENT) {
f048f3e2	417	error("channel %d: already sent close", c->self);
7e7327a1	418	} else {
	419	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	420	packet_put_int(c->remote_id);
	421	packet_send();
	422	c->flags \|= CHAN_CLOSE_SENT;
	423	}
	424	}
ee55dacf	425
	426	/* shared */
	427
719fc62f	428	void
	429	chan_mark_dead(Channel *c)
	430	{
6fd8622b	431	c->type = SSH_CHANNEL_ZOMBIE;
719fc62f	432	}
719fc62f	433
ee55dacf	434	int
ee55dacf	435	chan_is_dead(Channel *c)
5260325f	436	{
6fd8622b	437	if (c->type == SSH_CHANNEL_ZOMBIE) {
6fd8622b	438	debug("channel %d: zombie", c->self);
719fc62f	439	return 1;
6fd8622b	440	}
ee55dacf	441	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	442	return 0;
	443	if (!compat20) {
	444	debug("channel %d: is dead", c->self);
	445	return 1;
	446	}
	447	/*
	448	* we have to delay the close message if the efd (for stderr) is
	449	* still active
	450	*/
	451	if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
	452	buffer_len(&c->extended) > 0)
	453	#if 0
	454	\|\| ((c->extended_usage == CHAN_EXTENDED_READ) &&
	455	c->efd != -1)
	456	#endif
	457	) {
	458	debug2("channel %d: active efd: %d len %d type %s",
	459	c->self, c->efd, buffer_len(&c->extended),
	460	c->extended_usage==CHAN_EXTENDED_READ ?
	461	"read": "write");
	462	} else {
7e7327a1	463	if (!(c->flags & CHAN_CLOSE_SENT)) {
	464	chan_send_close2(c);
	465	}
6ae2364d	466	if ((c->flags & CHAN_CLOSE_SENT) &&
7e7327a1	467	(c->flags & CHAN_CLOSE_RCVD)) {
ee55dacf	468	debug("channel %d: is dead", c->self);
ee55dacf	469	return 1;
6ae2364d	470	}
8efc0c15	471	}
ee55dacf	472	return 0;
8efc0c15	473	}
7e7327a1	474
8efc0c15	475	void
5260325f	476	chan_init_iostates(Channel *c)
	477	{
	478	c->ostate = CHAN_OUTPUT_OPEN;
	479	c->istate = CHAN_INPUT_OPEN;
7e7327a1	480	c->flags = 0;
	481	}
	482
	483	/* init */
	484	void
	485	chan_init(void)
	486	{
	487	if (compat20) {
	488	chan_rcvd_oclose = chan_rcvd_oclose2;
	489	chan_read_failed = chan_read_failed_12;
	490	chan_ibuf_empty = chan_ibuf_empty2;
	491
	492	chan_rcvd_ieof = chan_rcvd_ieof2;
	493	chan_write_failed = chan_write_failed2;
	494	chan_obuf_empty = chan_obuf_empty2;
7e7327a1	495	} else {
	496	chan_rcvd_oclose = chan_rcvd_oclose1;
	497	chan_read_failed = chan_read_failed_12;
	498	chan_ibuf_empty = chan_ibuf_empty1;
	499
	500	chan_rcvd_ieof = chan_rcvd_ieof1;
	501	chan_write_failed = chan_write_failed1;
	502	chan_obuf_empty = chan_obuf_empty1;
7e7327a1	503	}
	504	}
	505
	506	/* helper */
	507	static void
	508	chan_shutdown_write(Channel *c)
	509	{
	510	buffer_consume(&c->output, buffer_len(&c->output));
	511	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	512	return;
	513	/* shutdown failure is allowed if write failed already */
	514	debug("channel %d: close_write", c->self);
	515	if (c->sock != -1) {
	516	if (shutdown(c->sock, SHUT_WR) < 0)
f048f3e2	517	debug("channel %d: chan_shutdown_write: "
f048f3e2	518	"shutdown() failed for fd%d: %.100s",
7e7327a1	519	c->self, c->sock, strerror(errno));
	520	} else {
	521	if (close(c->wfd) < 0)
f048f3e2	522	log("channel %d: chan_shutdown_write: "
f048f3e2	523	"close() failed for fd%d: %.100s",
7e7327a1	524	c->self, c->wfd, strerror(errno));
6fd8622b	525	c->wfd = -1;
7e7327a1	526	}
	527	}
	528	static void
	529	chan_shutdown_read(Channel *c)
	530	{
	531	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	532	return;
	533	debug("channel %d: close_read", c->self);
	534	if (c->sock != -1) {
2b87da3b	535	/*
47670e77	536	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
47670e77	537	* write side has been closed already. (bug on Linux)
fe39c3df	538	* HP-UX will return EINVAL.
47670e77	539	*/
47670e77	540	if (shutdown(c->sock, SHUT_RD) < 0
fe39c3df	541	&& (errno != ENOTCONN && errno != EINVAL))
f048f3e2	542	error("channel %d: chan_shutdown_read: "
	543	"shutdown() failed for fd%d [i%d o%d]: %.100s",
	544	c->self, c->sock, c->istate, c->ostate,
	545	strerror(errno));
7e7327a1	546	} else {
7e7327a1	547	if (close(c->rfd) < 0)
f048f3e2	548	log("channel %d: chan_shutdown_read: "
f048f3e2	549	"close() failed for fd%d: %.100s",
7e7327a1	550	c->self, c->rfd, strerror(errno));
6fd8622b	551	c->rfd = -1;
7e7327a1	552	}
8efc0c15	553	}