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

/* $OpenBSD: nchan.c,v 1.62 2008/11/07 18:50:18 stevesk Exp $ */
/*
 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"

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

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

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

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

/* functions manipulating channel states */
/*
 * EVENTS update channel input/output states execute ACTIONS
 */
/*
 * ACTIONS: should never update the channel states
 */
static void	chan_send_ieof1(Channel *);
static void	chan_send_oclose1(Channel *);
static void	chan_send_close2(Channel *);
static void	chan_send_eof2(Channel *);
static void	chan_send_eow2(Channel *);

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

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

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

/*
 * SSH1 specific implementation of event functions
 */

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

/*
 * the same for SSH2
 */
static void
chan_rcvd_close2(Channel *c)
{
	debug2("channel %d: rcvd close", c->self);
	if (c->flags & CHAN_CLOSE_RCVD)
		error("channel %d: protocol error: close rcvd twice", c->self);
	c->flags |= CHAN_CLOSE_RCVD;
	if (c->type == SSH_CHANNEL_LARVAL) {
		/* tear down larval channels immediately */
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		return;
	}
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		/*
		 * wait until a data from the channel is consumed if a CLOSE
		 * is received
		 */
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
		break;
	}
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		chan_shutdown_read(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	case CHAN_INPUT_WAIT_DRAIN:
		chan_send_eof2(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	}
}
void
chan_rcvd_eow(Channel *c)
{
	debug2("channel %d: rcvd eow", c->self);
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		chan_shutdown_read(c);
		chan_set_istate(c, CHAN_INPUT_CLOSED);
		break;
	}
}
static void
chan_rcvd_eof2(Channel *c)
{
	debug2("channel %d: rcvd eof", c->self);
	c->flags |= CHAN_EOF_RCVD;
	if (c->ostate == CHAN_OUTPUT_OPEN)
		chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
}
static void
chan_write_failed2(Channel *c)
{
	debug2("channel %d: write failed", c->self);
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
	case CHAN_OUTPUT_WAIT_DRAIN:
		chan_shutdown_write(c);
		if (strcmp(c->ctype, "session") == 0)
			chan_send_eow2(c);
		chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
		break;
	default:
		error("channel %d: chan_write_failed for ostate %d",
		    c->self, c->ostate);
		break;
	}
}
static void
chan_send_eof2(Channel *c)
{
	debug2("channel %d: send eof", c->self);
	switch (c->istate) {
	case CHAN_INPUT_WAIT_DRAIN:
		packet_start(SSH2_MSG_CHANNEL_EOF);
		packet_put_int(c->remote_id);
		packet_send();
		c->flags |= CHAN_EOF_SENT;
		break;
	default:
		error("channel %d: cannot send eof for istate %d",
		    c->self, c->istate);
		break;
	}
}
static void
chan_send_close2(Channel *c)
{
	debug2("channel %d: send close", c->self);
	if (c->ostate != CHAN_OUTPUT_CLOSED ||
	    c->istate != CHAN_INPUT_CLOSED) {
		error("channel %d: cannot send close for istate/ostate %d/%d",
		    c->self, c->istate, c->ostate);
	} else if (c->flags & CHAN_CLOSE_SENT) {
		error("channel %d: already sent close", c->self);
	} else {
		packet_start(SSH2_MSG_CHANNEL_CLOSE);
		packet_put_int(c->remote_id);
		packet_send();
		c->flags |= CHAN_CLOSE_SENT;
	}
}
static void
chan_send_eow2(Channel *c)
{
	debug2("channel %d: send eow", c->self);
	if (c->ostate == CHAN_OUTPUT_CLOSED) {
		error("channel %d: must not sent eow on closed output",
		    c->self);
		return;
	}
	if (!(datafellows & SSH_NEW_OPENSSH))
		return;
	packet_start(SSH2_MSG_CHANNEL_REQUEST);
	packet_put_int(c->remote_id);
	packet_put_cstring("eow@openssh.com");
	packet_put_char(0);
	packet_send();
}

/* shared */

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

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

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

/* helper */
static void
chan_shutdown_write(Channel *c)
{
	buffer_clear(&c->output);
	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
		return;
	/* shutdown failure is allowed if write failed already */
	debug2("channel %d: close_write", c->self);
	if (c->sock != -1) {
		if (shutdown(c->sock, SHUT_WR) < 0)
			debug2("channel %d: chan_shutdown_write: "
			    "shutdown() failed for fd %d: %.100s",
			    c->self, c->sock, strerror(errno));
	} else {
		if (channel_close_fd(&c->wfd) < 0)
			logit("channel %d: chan_shutdown_write: "
			    "close() failed for fd %d: %.100s",
			    c->self, c->wfd, strerror(errno));
	}
}
static void
chan_shutdown_read(Channel *c)
{
	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
		return;
	debug2("channel %d: close_read", c->self);
	if (c->sock != -1) {
		/*
		 * shutdown(sock, SHUT_READ) may return ENOTCONN if the
		 * write side has been closed already. (bug on Linux)
		 * HP-UX may return ENOTCONN also.
		 */
		if (shutdown(c->sock, SHUT_RD) < 0
		    && errno != ENOTCONN)
			error("channel %d: chan_shutdown_read: "
			    "shutdown() failed for fd %d [i%d o%d]: %.100s",
			    c->self, c->sock, c->istate, c->ostate,
			    strerror(errno));
	} else {
		if (channel_close_fd(&c->rfd) < 0)
			logit("channel %d: chan_shutdown_read: "
			    "close() failed for fd %d: %.100s",
			    c->self, c->rfd, strerror(errno));
	}
}
Commit	Line	Data
91d9cdd3	1	/* $OpenBSD: nchan.c,v 1.62 2008/11/07 18:50:18 stevesk Exp $ */
3c0ef626	2	/*
e9a17296	3	* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
3c0ef626	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	15	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	16	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	17	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	18	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	19	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	20	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	21	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	23	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
	26	#include "includes.h"
9108f8d9	27
	28	#include <sys/types.h>
	29	#include <sys/socket.h>
	30
	31	#include <errno.h>
	32	#include <string.h>
	33	#include <stdarg.h>
3c0ef626	34
22616013	35	#include "openbsd-compat/sys-queue.h"
3c0ef626	36	#include "ssh1.h"
	37	#include "ssh2.h"
	38	#include "buffer.h"
	39	#include "packet.h"
	40	#include "channels.h"
	41	#include "compat.h"
	42	#include "log.h"
	43
	44	/*
	45	* SSH Protocol 1.5 aka New Channel Protocol
	46	* Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.
	47	* Written by Markus Friedl in October 1999
	48	*
	49	* Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the
	50	* tear down of channels:
	51	*
	52	* 1.3: strict request-ack-protocol:
c9f39d2c	53	* CLOSE ->
c9f39d2c	54	* <- CLOSE_CONFIRM
3c0ef626	55	*
3c0ef626	56	* 1.5: uses variations of:
c9f39d2c	57	* IEOF ->
	58	* <- OCLOSE
	59	* <- IEOF
	60	* OCLOSE ->
	61	* i.e. both sides have to close the channel
3c0ef626	62	*
	63	* 2.0: the EOF messages are optional
	64	*
	65	* See the debugging output from 'ssh -v' and 'sshd -d' of
	66	* ssh-1.2.27 as an example.
	67	*
	68	*/
	69
	70	/* functions manipulating channel states */
	71	/*
	72	* EVENTS update channel input/output states execute ACTIONS
	73	*/
3c0ef626	74	/*
	75	* ACTIONS: should never update the channel states
	76	*/
	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 *);
22616013	81	static void chan_send_eow2(Channel *);
3c0ef626	82
	83	/* helper */
	84	static void chan_shutdown_write(Channel *);
	85	static void chan_shutdown_read(Channel *);
	86
e9a17296	87	static char *ostates[] = { "open", "drain", "wait_ieof", "closed" };
	88	static char *istates[] = { "open", "drain", "wait_oclose", "closed" };
	89
	90	static void
	91	chan_set_istate(Channel *c, u_int next)
	92	{
	93	if (c->istate > CHAN_INPUT_CLOSED \|\| next > CHAN_INPUT_CLOSED)
	94	fatal("chan_set_istate: bad state %d -> %d", c->istate, next);
0fff78ff	95	debug2("channel %d: input %s -> %s", c->self, istates[c->istate],
e9a17296	96	istates[next]);
	97	c->istate = next;
	98	}
	99	static void
	100	chan_set_ostate(Channel *c, u_int next)
	101	{
	102	if (c->ostate > CHAN_OUTPUT_CLOSED \|\| next > CHAN_OUTPUT_CLOSED)
	103	fatal("chan_set_ostate: bad state %d -> %d", c->ostate, next);
0fff78ff	104	debug2("channel %d: output %s -> %s", c->self, ostates[c->ostate],
e9a17296	105	ostates[next]);
	106	c->ostate = next;
	107	}
	108
3c0ef626	109	/*
	110	* SSH1 specific implementation of event functions
	111	*/
	112
	113	static void
	114	chan_rcvd_oclose1(Channel *c)
	115	{
0fff78ff	116	debug2("channel %d: rcvd oclose", c->self);
3c0ef626	117	switch (c->istate) {
3c0ef626	118	case CHAN_INPUT_WAIT_OCLOSE:
e9a17296	119	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	120	break;
3c0ef626	121	case CHAN_INPUT_OPEN:
3c0ef626	122	chan_shutdown_read(c);
3c0ef626	123	chan_send_ieof1(c);
e9a17296	124	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	125	break;
	126	case CHAN_INPUT_WAIT_DRAIN:
	127	/* both local read_failed and remote write_failed */
3c0ef626	128	chan_send_ieof1(c);
e9a17296	129	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	130	break;
	131	default:
	132	error("channel %d: protocol error: rcvd_oclose for istate %d",
	133	c->self, c->istate);
	134	return;
	135	}
	136	}
e9a17296	137	void
e9a17296	138	chan_read_failed(Channel *c)
3c0ef626	139	{
0fff78ff	140	debug2("channel %d: read failed", c->self);
3c0ef626	141	switch (c->istate) {
3c0ef626	142	case CHAN_INPUT_OPEN:
3c0ef626	143	chan_shutdown_read(c);
e9a17296	144	chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
3c0ef626	145	break;
	146	default:
	147	error("channel %d: chan_read_failed for istate %d",
	148	c->self, c->istate);
	149	break;
	150	}
	151	}
e9a17296	152	void
e9a17296	153	chan_ibuf_empty(Channel *c)
3c0ef626	154	{
0fff78ff	155	debug2("channel %d: ibuf empty", c->self);
3c0ef626	156	if (buffer_len(&c->input)) {
	157	error("channel %d: chan_ibuf_empty for non empty buffer",
	158	c->self);
	159	return;
	160	}
	161	switch (c->istate) {
	162	case CHAN_INPUT_WAIT_DRAIN:
e9a17296	163	if (compat20) {
	164	if (!(c->flags & CHAN_CLOSE_SENT))
	165	chan_send_eof2(c);
	166	chan_set_istate(c, CHAN_INPUT_CLOSED);
	167	} else {
	168	chan_send_ieof1(c);
	169	chan_set_istate(c, CHAN_INPUT_WAIT_OCLOSE);
	170	}
3c0ef626	171	break;
	172	default:
	173	error("channel %d: chan_ibuf_empty for istate %d",
	174	c->self, c->istate);
	175	break;
	176	}
	177	}
	178	static void
	179	chan_rcvd_ieof1(Channel *c)
	180	{
0fff78ff	181	debug2("channel %d: rcvd ieof", c->self);
3c0ef626	182	switch (c->ostate) {
3c0ef626	183	case CHAN_OUTPUT_OPEN:
e9a17296	184	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
3c0ef626	185	break;
3c0ef626	186	case CHAN_OUTPUT_WAIT_IEOF:
e9a17296	187	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	188	break;
	189	default:
	190	error("channel %d: protocol error: rcvd_ieof for ostate %d",
	191	c->self, c->ostate);
	192	break;
	193	}
	194	}
	195	static void
	196	chan_write_failed1(Channel *c)
	197	{
0fff78ff	198	debug2("channel %d: write failed", c->self);
3c0ef626	199	switch (c->ostate) {
3c0ef626	200	case CHAN_OUTPUT_OPEN:
e9a17296	201	chan_shutdown_write(c);
3c0ef626	202	chan_send_oclose1(c);
e9a17296	203	chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
3c0ef626	204	break;
3c0ef626	205	case CHAN_OUTPUT_WAIT_DRAIN:
e9a17296	206	chan_shutdown_write(c);
3c0ef626	207	chan_send_oclose1(c);
e9a17296	208	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	209	break;
	210	default:
	211	error("channel %d: chan_write_failed for ostate %d",
	212	c->self, c->ostate);
	213	break;
	214	}
	215	}
e9a17296	216	void
e9a17296	217	chan_obuf_empty(Channel *c)
3c0ef626	218	{
0fff78ff	219	debug2("channel %d: obuf empty", c->self);
3c0ef626	220	if (buffer_len(&c->output)) {
	221	error("channel %d: chan_obuf_empty for non empty buffer",
	222	c->self);
	223	return;
	224	}
	225	switch (c->ostate) {
	226	case CHAN_OUTPUT_WAIT_DRAIN:
e9a17296	227	chan_shutdown_write(c);
	228	if (!compat20)
	229	chan_send_oclose1(c);
	230	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	231	break;
	232	default:
	233	error("channel %d: internal error: obuf_empty for ostate %d",
	234	c->self, c->ostate);
	235	break;
	236	}
	237	}
	238	static void
	239	chan_send_ieof1(Channel *c)
	240	{
0fff78ff	241	debug2("channel %d: send ieof", c->self);
3c0ef626	242	switch (c->istate) {
	243	case CHAN_INPUT_OPEN:
	244	case CHAN_INPUT_WAIT_DRAIN:
	245	packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
	246	packet_put_int(c->remote_id);
	247	packet_send();
	248	break;
	249	default:
	250	error("channel %d: cannot send ieof for istate %d",
	251	c->self, c->istate);
	252	break;
	253	}
	254	}
	255	static void
	256	chan_send_oclose1(Channel *c)
	257	{
0fff78ff	258	debug2("channel %d: send oclose", c->self);
3c0ef626	259	switch (c->ostate) {
	260	case CHAN_OUTPUT_OPEN:
	261	case CHAN_OUTPUT_WAIT_DRAIN:
e9a17296	262	buffer_clear(&c->output);
3c0ef626	263	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	264	packet_put_int(c->remote_id);
	265	packet_send();
	266	break;
	267	default:
	268	error("channel %d: cannot send oclose for ostate %d",
e9a17296	269	c->self, c->ostate);
3c0ef626	270	break;
	271	}
	272	}
	273
	274	/*
	275	* the same for SSH2
	276	*/
	277	static void
e9a17296	278	chan_rcvd_close2(Channel *c)
3c0ef626	279	{
0fff78ff	280	debug2("channel %d: rcvd close", c->self);
3c0ef626	281	if (c->flags & CHAN_CLOSE_RCVD)
	282	error("channel %d: protocol error: close rcvd twice", c->self);
	283	c->flags \|= CHAN_CLOSE_RCVD;
	284	if (c->type == SSH_CHANNEL_LARVAL) {
	285	/* tear down larval channels immediately */
e9a17296	286	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
e9a17296	287	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	288	return;
	289	}
	290	switch (c->ostate) {
	291	case CHAN_OUTPUT_OPEN:
	292	/*
	293	* wait until a data from the channel is consumed if a CLOSE
	294	* is received
	295	*/
e9a17296	296	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
3c0ef626	297	break;
	298	}
	299	switch (c->istate) {
	300	case CHAN_INPUT_OPEN:
3c0ef626	301	chan_shutdown_read(c);
e9a17296	302	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	303	break;
3c0ef626	304	case CHAN_INPUT_WAIT_DRAIN:
3c0ef626	305	chan_send_eof2(c);
e9a17296	306	chan_set_istate(c, CHAN_INPUT_CLOSED);
3c0ef626	307	break;
	308	}
	309	}
22616013	310	void
	311	chan_rcvd_eow(Channel *c)
	312	{
	313	debug2("channel %d: rcvd eow", c->self);
	314	switch (c->istate) {
	315	case CHAN_INPUT_OPEN:
	316	chan_shutdown_read(c);
	317	chan_set_istate(c, CHAN_INPUT_CLOSED);
	318	break;
	319	}
	320	}
3c0ef626	321	static void
e9a17296	322	chan_rcvd_eof2(Channel *c)
3c0ef626	323	{
0fff78ff	324	debug2("channel %d: rcvd eof", c->self);
700318f3	325	c->flags \|= CHAN_EOF_RCVD;
e9a17296	326	if (c->ostate == CHAN_OUTPUT_OPEN)
e9a17296	327	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
3c0ef626	328	}
	329	static void
	330	chan_write_failed2(Channel *c)
	331	{
0fff78ff	332	debug2("channel %d: write failed", c->self);
3c0ef626	333	switch (c->ostate) {
3c0ef626	334	case CHAN_OUTPUT_OPEN:
3c0ef626	335	case CHAN_OUTPUT_WAIT_DRAIN:
3c0ef626	336	chan_shutdown_write(c);
22616013	337	if (strcmp(c->ctype, "session") == 0)
22616013	338	chan_send_eow2(c);
e9a17296	339	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
3c0ef626	340	break;
	341	default:
	342	error("channel %d: chan_write_failed for ostate %d",
	343	c->self, c->ostate);
	344	break;
	345	}
	346	}
	347	static void
3c0ef626	348	chan_send_eof2(Channel *c)
3c0ef626	349	{
0fff78ff	350	debug2("channel %d: send eof", c->self);
3c0ef626	351	switch (c->istate) {
	352	case CHAN_INPUT_WAIT_DRAIN:
	353	packet_start(SSH2_MSG_CHANNEL_EOF);
	354	packet_put_int(c->remote_id);
	355	packet_send();
700318f3	356	c->flags \|= CHAN_EOF_SENT;
3c0ef626	357	break;
	358	default:
	359	error("channel %d: cannot send eof for istate %d",
	360	c->self, c->istate);
	361	break;
	362	}
	363	}
	364	static void
	365	chan_send_close2(Channel *c)
	366	{
0fff78ff	367	debug2("channel %d: send close", c->self);
3c0ef626	368	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
	369	c->istate != CHAN_INPUT_CLOSED) {
	370	error("channel %d: cannot send close for istate/ostate %d/%d",
	371	c->self, c->istate, c->ostate);
	372	} else if (c->flags & CHAN_CLOSE_SENT) {
	373	error("channel %d: already sent close", c->self);
	374	} else {
	375	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	376	packet_put_int(c->remote_id);
	377	packet_send();
	378	c->flags \|= CHAN_CLOSE_SENT;
	379	}
	380	}
22616013	381	static void
	382	chan_send_eow2(Channel *c)
	383	{
	384	debug2("channel %d: send eow", c->self);
	385	if (c->ostate == CHAN_OUTPUT_CLOSED) {
	386	error("channel %d: must not sent eow on closed output",
	387	c->self);
	388	return;
	389	}
91d9cdd3	390	if (!(datafellows & SSH_NEW_OPENSSH))
91d9cdd3	391	return;
22616013	392	packet_start(SSH2_MSG_CHANNEL_REQUEST);
	393	packet_put_int(c->remote_id);
	394	packet_put_cstring("eow@openssh.com");
	395	packet_put_char(0);
	396	packet_send();
	397	}
3c0ef626	398
	399	/* shared */
	400
e9a17296	401	void
	402	chan_rcvd_ieof(Channel *c)
	403	{
	404	if (compat20)
	405	chan_rcvd_eof2(c);
	406	else
	407	chan_rcvd_ieof1(c);
	408	if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
f5799ae1	409	buffer_len(&c->output) == 0 &&
700318f3	410	!CHANNEL_EFD_OUTPUT_ACTIVE(c))
e9a17296	411	chan_obuf_empty(c);
	412	}
	413	void
	414	chan_rcvd_oclose(Channel *c)
	415	{
	416	if (compat20)
	417	chan_rcvd_close2(c);
	418	else
	419	chan_rcvd_oclose1(c);
	420	}
	421	void
	422	chan_write_failed(Channel *c)
	423	{
	424	if (compat20)
	425	chan_write_failed2(c);
	426	else
	427	chan_write_failed1(c);
	428	}
	429
3c0ef626	430	void
	431	chan_mark_dead(Channel *c)
	432	{
	433	c->type = SSH_CHANNEL_ZOMBIE;
	434	}
	435
	436	int
c9f39d2c	437	chan_is_dead(Channel *c, int do_send)
3c0ef626	438	{
3c0ef626	439	if (c->type == SSH_CHANNEL_ZOMBIE) {
0fff78ff	440	debug2("channel %d: zombie", c->self);
3c0ef626	441	return 1;
	442	}
	443	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	444	return 0;
	445	if (!compat20) {
0fff78ff	446	debug2("channel %d: is dead", c->self);
3c0ef626	447	return 1;
3c0ef626	448	}
700318f3	449	if ((datafellows & SSH_BUG_EXTEOF) &&
	450	c->extended_usage == CHAN_EXTENDED_WRITE &&
	451	c->efd != -1 &&
	452	buffer_len(&c->extended) > 0) {
f5799ae1	453	debug2("channel %d: active efd: %d len %d",
f5799ae1	454	c->self, c->efd, buffer_len(&c->extended));
700318f3	455	return 0;
	456	}
	457	if (!(c->flags & CHAN_CLOSE_SENT)) {
c9f39d2c	458	if (do_send) {
700318f3	459	chan_send_close2(c);
	460	} else {
	461	/* channel would be dead if we sent a close */
	462	if (c->flags & CHAN_CLOSE_RCVD) {
0fff78ff	463	debug2("channel %d: almost dead",
700318f3	464	c->self);
700318f3	465	return 1;
3c0ef626	466	}
3c0ef626	467	}
700318f3	468	}
	469	if ((c->flags & CHAN_CLOSE_SENT) &&
	470	(c->flags & CHAN_CLOSE_RCVD)) {
0fff78ff	471	debug2("channel %d: is dead", c->self);
700318f3	472	return 1;
3c0ef626	473	}
	474	return 0;
	475	}
	476
3c0ef626	477	/* helper */
	478	static void
	479	chan_shutdown_write(Channel *c)
	480	{
e9a17296	481	buffer_clear(&c->output);
3c0ef626	482	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	483	return;
	484	/* shutdown failure is allowed if write failed already */
0fff78ff	485	debug2("channel %d: close_write", c->self);
3c0ef626	486	if (c->sock != -1) {
3c0ef626	487	if (shutdown(c->sock, SHUT_WR) < 0)
0fff78ff	488	debug2("channel %d: chan_shutdown_write: "
91d9cdd3	489	"shutdown() failed for fd %d: %.100s",
3c0ef626	490	c->self, c->sock, strerror(errno));
	491	} else {
	492	if (channel_close_fd(&c->wfd) < 0)
0fff78ff	493	logit("channel %d: chan_shutdown_write: "
91d9cdd3	494	"close() failed for fd %d: %.100s",
3c0ef626	495	c->self, c->wfd, strerror(errno));
	496	}
	497	}
	498	static void
	499	chan_shutdown_read(Channel *c)
	500	{
	501	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	502	return;
0fff78ff	503	debug2("channel %d: close_read", c->self);
3c0ef626	504	if (c->sock != -1) {
	505	/*
	506	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
	507	* write side has been closed already. (bug on Linux)
	508	* HP-UX may return ENOTCONN also.
	509	*/
	510	if (shutdown(c->sock, SHUT_RD) < 0
	511	&& errno != ENOTCONN)
	512	error("channel %d: chan_shutdown_read: "
91d9cdd3	513	"shutdown() failed for fd %d [i%d o%d]: %.100s",
3c0ef626	514	c->self, c->sock, c->istate, c->ostate,
	515	strerror(errno));
	516	} else {
	517	if (channel_close_fd(&c->rfd) < 0)
0fff78ff	518	logit("channel %d: chan_shutdown_read: "
91d9cdd3	519	"close() failed for fd %d: %.100s",
3c0ef626	520	c->self, c->rfd, strerror(errno));
	521	}
	522	}