[openssh.git] / nchan.c

/*
 * Copyright (c) 1999, 2000, 2001 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 1.36 2002/01/10 12:47:59 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 *);
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 *);

/*
 * 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;
		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);
	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_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_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, 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;
}

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_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
aa3378df	1	/*
a96070d4	2	* Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
aa3378df	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"
6d566d33	26	RCSID("$OpenBSD: nchan.c,v 1.36 2002/01/10 12:47:59 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	*/
1b73841d	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	*/
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
	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;
8efc0c15	126	break;
8efc0c15	127	default:
f048f3e2	128	error("channel %d: chan_read_failed for istate %d",
7e7327a1	129	c->self, c->istate);
8efc0c15	130	break;
	131	}
	132	}
7e7327a1	133	static void
7e7327a1	134	chan_ibuf_empty1(Channel *c)
5260325f	135	{
7e7327a1	136	debug("channel %d: ibuf empty", c->self);
5260325f	137	if (buffer_len(&c->input)) {
f048f3e2	138	error("channel %d: chan_ibuf_empty for non empty buffer",
7e7327a1	139	c->self);
8efc0c15	140	return;
8efc0c15	141	}
5260325f	142	switch (c->istate) {
8efc0c15	143	case CHAN_INPUT_WAIT_DRAIN:
7e7327a1	144	debug("channel %d: input drain -> wait_oclose", c->self);
7e7327a1	145	chan_send_ieof1(c);
5260325f	146	c->istate = CHAN_INPUT_WAIT_OCLOSE;
8efc0c15	147	break;
8efc0c15	148	default:
f048f3e2	149	error("channel %d: chan_ibuf_empty for istate %d",
7e7327a1	150	c->self, c->istate);
8efc0c15	151	break;
	152	}
	153	}
7e7327a1	154	static void
7e7327a1	155	chan_rcvd_ieof1(Channel *c)
5260325f	156	{
7e7327a1	157	debug("channel %d: rcvd ieof", c->self);
5260325f	158	switch (c->ostate) {
8efc0c15	159	case CHAN_OUTPUT_OPEN:
7e7327a1	160	debug("channel %d: output open -> drain", c->self);
5260325f	161	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
8efc0c15	162	break;
8efc0c15	163	case CHAN_OUTPUT_WAIT_IEOF:
7e7327a1	164	debug("channel %d: output wait_ieof -> closed", c->self);
5260325f	165	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	166	break;
8efc0c15	167	default:
f048f3e2	168	error("channel %d: protocol error: rcvd_ieof for ostate %d",
7e7327a1	169	c->self, c->ostate);
8efc0c15	170	break;
	171	}
	172	}
7e7327a1	173	static void
7e7327a1	174	chan_write_failed1(Channel *c)
5260325f	175	{
7e7327a1	176	debug("channel %d: write failed", c->self);
5260325f	177	switch (c->ostate) {
8efc0c15	178	case CHAN_OUTPUT_OPEN:
7e7327a1	179	debug("channel %d: output open -> wait_ieof", c->self);
7e7327a1	180	chan_send_oclose1(c);
5260325f	181	c->ostate = CHAN_OUTPUT_WAIT_IEOF;
8efc0c15	182	break;
8efc0c15	183	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	184	debug("channel %d: output wait_drain -> closed", c->self);
7e7327a1	185	chan_send_oclose1(c);
5260325f	186	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	187	break;
8efc0c15	188	default:
f048f3e2	189	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	190	c->self, c->ostate);
8efc0c15	191	break;
	192	}
	193	}
7e7327a1	194	static void
7e7327a1	195	chan_obuf_empty1(Channel *c)
5260325f	196	{
7e7327a1	197	debug("channel %d: obuf empty", c->self);
5260325f	198	if (buffer_len(&c->output)) {
f048f3e2	199	error("channel %d: chan_obuf_empty for non empty buffer",
7e7327a1	200	c->self);
8efc0c15	201	return;
8efc0c15	202	}
5260325f	203	switch (c->ostate) {
8efc0c15	204	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	205	debug("channel %d: output drain -> closed", c->self);
7e7327a1	206	chan_send_oclose1(c);
5260325f	207	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	208	break;
8efc0c15	209	default:
f048f3e2	210	error("channel %d: internal error: obuf_empty for ostate %d",
7e7327a1	211	c->self, c->ostate);
8efc0c15	212	break;
	213	}
	214	}
8efc0c15	215	static void
7e7327a1	216	chan_send_ieof1(Channel *c)
5260325f	217	{
7e7327a1	218	debug("channel %d: send ieof", c->self);
5260325f	219	switch (c->istate) {
8efc0c15	220	case CHAN_INPUT_OPEN:
	221	case CHAN_INPUT_WAIT_DRAIN:
	222	packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
	223	packet_put_int(c->remote_id);
	224	packet_send();
	225	break;
	226	default:
f048f3e2	227	error("channel %d: cannot send ieof for istate %d",
7e7327a1	228	c->self, c->istate);
8efc0c15	229	break;
	230	}
	231	}
	232	static void
7e7327a1	233	chan_send_oclose1(Channel *c)
5260325f	234	{
7e7327a1	235	debug("channel %d: send oclose", c->self);
5260325f	236	switch (c->ostate) {
8efc0c15	237	case CHAN_OUTPUT_OPEN:
	238	case CHAN_OUTPUT_WAIT_DRAIN:
	239	chan_shutdown_write(c);
9c50edcf	240	buffer_clear(&c->output);
8efc0c15	241	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	242	packet_put_int(c->remote_id);
	243	packet_send();
	244	break;
	245	default:
f048f3e2	246	error("channel %d: cannot send oclose for ostate %d",
184eed6a	247	c->self, c->ostate);
8efc0c15	248	break;
	249	}
	250	}
5260325f	251
7e7327a1	252	/*
	253	* the same for SSH2
	254	*/
8efc0c15	255	static void
7e7327a1	256	chan_rcvd_oclose2(Channel *c)
5260325f	257	{
7e7327a1	258	debug("channel %d: rcvd close", c->self);
	259	if (c->flags & CHAN_CLOSE_RCVD)
	260	error("channel %d: protocol error: close rcvd twice", c->self);
	261	c->flags \|= CHAN_CLOSE_RCVD;
	262	if (c->type == SSH_CHANNEL_LARVAL) {
	263	/* tear down larval channels immediately */
	264	c->ostate = CHAN_OUTPUT_CLOSED;
	265	c->istate = CHAN_INPUT_CLOSED;
	266	return;
	267	}
	268	switch (c->ostate) {
	269	case CHAN_OUTPUT_OPEN:
f048f3e2	270	/*
	271	* wait until a data from the channel is consumed if a CLOSE
	272	* is received
	273	*/
7e7327a1	274	debug("channel %d: output open -> drain", c->self);
	275	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
	276	break;
	277	}
	278	switch (c->istate) {
	279	case CHAN_INPUT_OPEN:
	280	debug("channel %d: input open -> closed", c->self);
	281	chan_shutdown_read(c);
	282	break;
	283	case CHAN_INPUT_WAIT_DRAIN:
	284	debug("channel %d: input drain -> closed", c->self);
	285	chan_send_eof2(c);
	286	break;
	287	}
	288	c->istate = CHAN_INPUT_CLOSED;
8efc0c15	289	}
8efc0c15	290	static void
7e7327a1	291	chan_ibuf_empty2(Channel *c)
	292	{
	293	debug("channel %d: ibuf empty", c->self);
	294	if (buffer_len(&c->input)) {
f048f3e2	295	error("channel %d: chan_ibuf_empty for non empty buffer",
184eed6a	296	c->self);
7e7327a1	297	return;
	298	}
	299	switch (c->istate) {
	300	case CHAN_INPUT_WAIT_DRAIN:
	301	debug("channel %d: input drain -> closed", c->self);
	302	if (!(c->flags & CHAN_CLOSE_SENT))
	303	chan_send_eof2(c);
	304	c->istate = CHAN_INPUT_CLOSED;
	305	break;
	306	default:
f048f3e2	307	error("channel %d: chan_ibuf_empty for istate %d",
184eed6a	308	c->self, c->istate);
7e7327a1	309	break;
	310	}
	311	}
	312	static void
	313	chan_rcvd_ieof2(Channel *c)
5260325f	314	{
7e7327a1	315	debug("channel %d: rcvd eof", c->self);
	316	if (c->ostate == CHAN_OUTPUT_OPEN) {
	317	debug("channel %d: output open -> drain", c->self);
	318	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
	319	}
8efc0c15	320	}
7e7327a1	321	static void
	322	chan_write_failed2(Channel *c)
	323	{
	324	debug("channel %d: write failed", c->self);
	325	switch (c->ostate) {
	326	case CHAN_OUTPUT_OPEN:
	327	debug("channel %d: output open -> closed", c->self);
1d1ffb87	328	chan_shutdown_write(c); /* ?? */
7e7327a1	329	c->ostate = CHAN_OUTPUT_CLOSED;
	330	break;
	331	case CHAN_OUTPUT_WAIT_DRAIN:
	332	debug("channel %d: output drain -> closed", c->self);
	333	chan_shutdown_write(c);
	334	c->ostate = CHAN_OUTPUT_CLOSED;
	335	break;
	336	default:
f048f3e2	337	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	338	c->self, c->ostate);
	339	break;
	340	}
	341	}
	342	static void
	343	chan_obuf_empty2(Channel *c)
	344	{
	345	debug("channel %d: obuf empty", c->self);
	346	if (buffer_len(&c->output)) {
f048f3e2	347	error("channel %d: chan_obuf_empty for non empty buffer",
7e7327a1	348	c->self);
	349	return;
	350	}
	351	switch (c->ostate) {
	352	case CHAN_OUTPUT_WAIT_DRAIN:
	353	debug("channel %d: output drain -> closed", c->self);
	354	chan_shutdown_write(c);
	355	c->ostate = CHAN_OUTPUT_CLOSED;
	356	break;
	357	default:
f048f3e2	358	error("channel %d: chan_obuf_empty for ostate %d",
7e7327a1	359	c->self, c->ostate);
	360	break;
	361	}
	362	}
	363	static void
	364	chan_send_eof2(Channel *c)
	365	{
	366	debug("channel %d: send eof", c->self);
	367	switch (c->istate) {
	368	case CHAN_INPUT_WAIT_DRAIN:
	369	packet_start(SSH2_MSG_CHANNEL_EOF);
	370	packet_put_int(c->remote_id);
	371	packet_send();
	372	break;
	373	default:
f048f3e2	374	error("channel %d: cannot send eof for istate %d",
7e7327a1	375	c->self, c->istate);
	376	break;
	377	}
	378	}
	379	static void
	380	chan_send_close2(Channel *c)
	381	{
	382	debug("channel %d: send close", c->self);
	383	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
	384	c->istate != CHAN_INPUT_CLOSED) {
f048f3e2	385	error("channel %d: cannot send close for istate/ostate %d/%d",
7e7327a1	386	c->self, c->istate, c->ostate);
7e7327a1	387	} else if (c->flags & CHAN_CLOSE_SENT) {
f048f3e2	388	error("channel %d: already sent close", c->self);
7e7327a1	389	} else {
	390	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	391	packet_put_int(c->remote_id);
	392	packet_send();
	393	c->flags \|= CHAN_CLOSE_SENT;
	394	}
	395	}
ee55dacf	396
	397	/* shared */
	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
418e724c	406	chan_is_dead(Channel *c, int send)
5260325f	407	{
6fd8622b	408	if (c->type == SSH_CHANNEL_ZOMBIE) {
6fd8622b	409	debug("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) {
	415	debug("channel %d: is dead", c->self);
	416	return 1;
	417	}
	418	/*
	419	* we have to delay the close message if the efd (for stderr) is
	420	* still active
	421	*/
	422	if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
	423	buffer_len(&c->extended) > 0)
	424	#if 0
	425	\|\| ((c->extended_usage == CHAN_EXTENDED_READ) &&
	426	c->efd != -1)
	427	#endif
	428	) {
	429	debug2("channel %d: active efd: %d len %d type %s",
	430	c->self, c->efd, buffer_len(&c->extended),
	431	c->extended_usage==CHAN_EXTENDED_READ ?
184eed6a	432	"read": "write");
ee55dacf	433	} else {
7e7327a1	434	if (!(c->flags & CHAN_CLOSE_SENT)) {
418e724c	435	if (send) {
	436	chan_send_close2(c);
	437	} else {
	438	/* channel would be dead if we sent a close */
	439	if (c->flags & CHAN_CLOSE_RCVD) {
	440	debug("channel %d: almost dead",
	441	c->self);
	442	return 1;
	443	}
	444	}
7e7327a1	445	}
6ae2364d	446	if ((c->flags & CHAN_CLOSE_SENT) &&
7e7327a1	447	(c->flags & CHAN_CLOSE_RCVD)) {
ee55dacf	448	debug("channel %d: is dead", c->self);
ee55dacf	449	return 1;
6ae2364d	450	}
8efc0c15	451	}
ee55dacf	452	return 0;
8efc0c15	453	}
7e7327a1	454
8efc0c15	455	void
5260325f	456	chan_init_iostates(Channel *c)
	457	{
	458	c->ostate = CHAN_OUTPUT_OPEN;
	459	c->istate = CHAN_INPUT_OPEN;
7e7327a1	460	c->flags = 0;
	461	}
	462
	463	/* init */
	464	void
	465	chan_init(void)
	466	{
	467	if (compat20) {
	468	chan_rcvd_oclose = chan_rcvd_oclose2;
	469	chan_read_failed = chan_read_failed_12;
	470	chan_ibuf_empty = chan_ibuf_empty2;
	471
	472	chan_rcvd_ieof = chan_rcvd_ieof2;
	473	chan_write_failed = chan_write_failed2;
	474	chan_obuf_empty = chan_obuf_empty2;
7e7327a1	475	} else {
	476	chan_rcvd_oclose = chan_rcvd_oclose1;
	477	chan_read_failed = chan_read_failed_12;
	478	chan_ibuf_empty = chan_ibuf_empty1;
	479
	480	chan_rcvd_ieof = chan_rcvd_ieof1;
	481	chan_write_failed = chan_write_failed1;
	482	chan_obuf_empty = chan_obuf_empty1;
7e7327a1	483	}
	484	}
	485
	486	/* helper */
	487	static void
	488	chan_shutdown_write(Channel *c)
	489	{
9c50edcf	490	buffer_clear(&c->output);
7e7327a1	491	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	492	return;
	493	/* shutdown failure is allowed if write failed already */
	494	debug("channel %d: close_write", c->self);
	495	if (c->sock != -1) {
	496	if (shutdown(c->sock, SHUT_WR) < 0)
f048f3e2	497	debug("channel %d: chan_shutdown_write: "
f048f3e2	498	"shutdown() failed for fd%d: %.100s",
7e7327a1	499	c->self, c->sock, strerror(errno));
7e7327a1	500	} else {
489aa2e9	501	if (channel_close_fd(&c->wfd) < 0)
f048f3e2	502	log("channel %d: chan_shutdown_write: "
f048f3e2	503	"close() failed for fd%d: %.100s",
7e7327a1	504	c->self, c->wfd, strerror(errno));
7e7327a1	505	}
	506	}
	507	static void
	508	chan_shutdown_read(Channel *c)
	509	{
	510	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	511	return;
	512	debug("channel %d: close_read", c->self);
	513	if (c->sock != -1) {
2b87da3b	514	/*
47670e77	515	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
47670e77	516	* write side has been closed already. (bug on Linux)
f49df8e9	517	* HP-UX may return ENOTCONN also.
47670e77	518	*/
47670e77	519	if (shutdown(c->sock, SHUT_RD) < 0
f49df8e9	520	&& errno != ENOTCONN)
f048f3e2	521	error("channel %d: chan_shutdown_read: "
	522	"shutdown() failed for fd%d [i%d o%d]: %.100s",
	523	c->self, c->sock, c->istate, c->ostate,
1b73841d	524	strerror(errno));
7e7327a1	525	} else {
489aa2e9	526	if (channel_close_fd(&c->rfd) < 0)
f048f3e2	527	log("channel %d: chan_shutdown_read: "
f048f3e2	528	"close() failed for fd%d: %.100s",
7e7327a1	529	c->self, c->rfd, strerror(errno));
7e7327a1	530	}
8efc0c15	531	}