[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 1.40 2002/01/14 13:40:10 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
 */
/* 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 *);

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;
	}
}
static void
chan_read_failed_12(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;
	}
}
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:
		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;
	}
}
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:
		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_ibuf_empty2(Channel *c)
{
	chan_ibuf_empty1(c);
}
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:
		chan_shutdown_write(c); /* ?? */
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		break;
	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_obuf_empty2(Channel *c)
{
	chan_obuf_empty1(c);
}
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_close2;
		chan_read_failed		= chan_read_failed_12;
		chan_ibuf_empty			= chan_ibuf_empty2;

		chan_rcvd_ieof			= chan_rcvd_eof2;
		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"
668a91b7	26	RCSID("$OpenBSD: nchan.c,v 1.40 2002/01/14 13:40:10 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
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);
	94	debug("channel %d: input %s -> %s", c->self, istates[c->istate],
	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);
	103	debug("channel %d: output %s -> %s", c->self, ostates[c->ostate],
	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	{
7e7327a1	115	debug("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	}
7e7327a1	136	static void
7e7327a1	137	chan_read_failed_12(Channel *c)
5260325f	138	{
7e7327a1	139	debug("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	}
7e7327a1	151	static void
7e7327a1	152	chan_ibuf_empty1(Channel *c)
5260325f	153	{
7e7327a1	154	debug("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	{
7e7327a1	180	debug("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	{
7e7327a1	197	debug("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	}
7e7327a1	215	static void
7e7327a1	216	chan_obuf_empty1(Channel *c)
5260325f	217	{
7e7327a1	218	debug("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	{
7e7327a1	240	debug("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	{
7e7327a1	257	debug("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	{
7e7327a1	279	debug("channel %d: rcvd close", c->self);
	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
7e7327a1	310	chan_ibuf_empty2(Channel *c)
7e7327a1	311	{
3057c23b	312	chan_ibuf_empty1(c);
7e7327a1	313	}
7e7327a1	314	static void
668a91b7	315	chan_rcvd_eof2(Channel *c)
5260325f	316	{
7e7327a1	317	debug("channel %d: rcvd eof", c->self);
368e9dfc	318	if (c->ostate == CHAN_OUTPUT_OPEN)
368e9dfc	319	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
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:
1d1ffb87	327	chan_shutdown_write(c); /* ?? */
368e9dfc	328	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
7e7327a1	329	break;
7e7327a1	330	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	331	chan_shutdown_write(c);
368e9dfc	332	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
7e7327a1	333	break;
7e7327a1	334	default:
f048f3e2	335	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	336	c->self, c->ostate);
	337	break;
	338	}
	339	}
	340	static void
	341	chan_obuf_empty2(Channel *c)
	342	{
3057c23b	343	chan_obuf_empty1(c);
7e7327a1	344	}
	345	static void
	346	chan_send_eof2(Channel *c)
	347	{
	348	debug("channel %d: send eof", c->self);
	349	switch (c->istate) {
	350	case CHAN_INPUT_WAIT_DRAIN:
	351	packet_start(SSH2_MSG_CHANNEL_EOF);
	352	packet_put_int(c->remote_id);
	353	packet_send();
	354	break;
	355	default:
f048f3e2	356	error("channel %d: cannot send eof for istate %d",
7e7327a1	357	c->self, c->istate);
	358	break;
	359	}
	360	}
	361	static void
	362	chan_send_close2(Channel *c)
	363	{
	364	debug("channel %d: send close", c->self);
	365	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
	366	c->istate != CHAN_INPUT_CLOSED) {
f048f3e2	367	error("channel %d: cannot send close for istate/ostate %d/%d",
7e7327a1	368	c->self, c->istate, c->ostate);
7e7327a1	369	} else if (c->flags & CHAN_CLOSE_SENT) {
f048f3e2	370	error("channel %d: already sent close", c->self);
7e7327a1	371	} else {
	372	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	373	packet_put_int(c->remote_id);
	374	packet_send();
	375	c->flags \|= CHAN_CLOSE_SENT;
	376	}
	377	}
ee55dacf	378
	379	/* shared */
	380
719fc62f	381	void
	382	chan_mark_dead(Channel *c)
	383	{
6fd8622b	384	c->type = SSH_CHANNEL_ZOMBIE;
719fc62f	385	}
719fc62f	386
ee55dacf	387	int
418e724c	388	chan_is_dead(Channel *c, int send)
5260325f	389	{
6fd8622b	390	if (c->type == SSH_CHANNEL_ZOMBIE) {
6fd8622b	391	debug("channel %d: zombie", c->self);
719fc62f	392	return 1;
6fd8622b	393	}
ee55dacf	394	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	395	return 0;
	396	if (!compat20) {
	397	debug("channel %d: is dead", c->self);
	398	return 1;
	399	}
	400	/*
	401	* we have to delay the close message if the efd (for stderr) is
	402	* still active
	403	*/
	404	if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
	405	buffer_len(&c->extended) > 0)
	406	#if 0
	407	\|\| ((c->extended_usage == CHAN_EXTENDED_READ) &&
	408	c->efd != -1)
	409	#endif
	410	) {
	411	debug2("channel %d: active efd: %d len %d type %s",
	412	c->self, c->efd, buffer_len(&c->extended),
	413	c->extended_usage==CHAN_EXTENDED_READ ?
184eed6a	414	"read": "write");
ee55dacf	415	} else {
7e7327a1	416	if (!(c->flags & CHAN_CLOSE_SENT)) {
418e724c	417	if (send) {
	418	chan_send_close2(c);
	419	} else {
	420	/* channel would be dead if we sent a close */
	421	if (c->flags & CHAN_CLOSE_RCVD) {
	422	debug("channel %d: almost dead",
	423	c->self);
	424	return 1;
	425	}
	426	}
7e7327a1	427	}
6ae2364d	428	if ((c->flags & CHAN_CLOSE_SENT) &&
7e7327a1	429	(c->flags & CHAN_CLOSE_RCVD)) {
ee55dacf	430	debug("channel %d: is dead", c->self);
ee55dacf	431	return 1;
6ae2364d	432	}
8efc0c15	433	}
ee55dacf	434	return 0;
8efc0c15	435	}
7e7327a1	436
8efc0c15	437	void
5260325f	438	chan_init_iostates(Channel *c)
	439	{
	440	c->ostate = CHAN_OUTPUT_OPEN;
	441	c->istate = CHAN_INPUT_OPEN;
7e7327a1	442	c->flags = 0;
	443	}
	444
	445	/* init */
	446	void
	447	chan_init(void)
	448	{
	449	if (compat20) {
668a91b7	450	chan_rcvd_oclose = chan_rcvd_close2;
7e7327a1	451	chan_read_failed = chan_read_failed_12;
	452	chan_ibuf_empty = chan_ibuf_empty2;
	453
668a91b7	454	chan_rcvd_ieof = chan_rcvd_eof2;
7e7327a1	455	chan_write_failed = chan_write_failed2;
7e7327a1	456	chan_obuf_empty = chan_obuf_empty2;
7e7327a1	457	} else {
	458	chan_rcvd_oclose = chan_rcvd_oclose1;
	459	chan_read_failed = chan_read_failed_12;
	460	chan_ibuf_empty = chan_ibuf_empty1;
	461
	462	chan_rcvd_ieof = chan_rcvd_ieof1;
	463	chan_write_failed = chan_write_failed1;
	464	chan_obuf_empty = chan_obuf_empty1;
7e7327a1	465	}
	466	}
	467
	468	/* helper */
	469	static void
	470	chan_shutdown_write(Channel *c)
	471	{
9c50edcf	472	buffer_clear(&c->output);
7e7327a1	473	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	474	return;
	475	/* shutdown failure is allowed if write failed already */
	476	debug("channel %d: close_write", c->self);
	477	if (c->sock != -1) {
	478	if (shutdown(c->sock, SHUT_WR) < 0)
f048f3e2	479	debug("channel %d: chan_shutdown_write: "
f048f3e2	480	"shutdown() failed for fd%d: %.100s",
7e7327a1	481	c->self, c->sock, strerror(errno));
7e7327a1	482	} else {
489aa2e9	483	if (channel_close_fd(&c->wfd) < 0)
f048f3e2	484	log("channel %d: chan_shutdown_write: "
f048f3e2	485	"close() failed for fd%d: %.100s",
7e7327a1	486	c->self, c->wfd, strerror(errno));
7e7327a1	487	}
	488	}
	489	static void
	490	chan_shutdown_read(Channel *c)
	491	{
	492	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	493	return;
	494	debug("channel %d: close_read", c->self);
	495	if (c->sock != -1) {
2b87da3b	496	/*
47670e77	497	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
47670e77	498	* write side has been closed already. (bug on Linux)
f49df8e9	499	* HP-UX may return ENOTCONN also.
47670e77	500	*/
47670e77	501	if (shutdown(c->sock, SHUT_RD) < 0
f49df8e9	502	&& errno != ENOTCONN)
f048f3e2	503	error("channel %d: chan_shutdown_read: "
	504	"shutdown() failed for fd%d [i%d o%d]: %.100s",
	505	c->self, c->sock, c->istate, c->ostate,
1b73841d	506	strerror(errno));
7e7327a1	507	} else {
489aa2e9	508	if (channel_close_fd(&c->rfd) < 0)
f048f3e2	509	log("channel %d: chan_shutdown_read: "
f048f3e2	510	"close() failed for fd%d: %.100s",
7e7327a1	511	c->self, c->rfd, strerror(errno));
7e7327a1	512	}
8efc0c15	513	}