[openssh.git] / 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
92d0164c	1	/* $OpenBSD: nchan.c,v 1.62 2008/11/07 18:50:18 stevesk Exp $ */
aa3378df	2	/*
8ab5f6b2	3	* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
aa3378df	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.
aa3378df	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
8efc0c15	26	#include "includes.h"
8efc0c15	27
5b04a8bf	28	#include <sys/types.h>
	29	#include <sys/socket.h>
	30
028094f4	31	#include <errno.h>
00146caa	32	#include <string.h>
31652869	33	#include <stdarg.h>
028094f4	34
3593bdc0	35	#include "openbsd-compat/sys-queue.h"
42f11eb2	36	#include "ssh1.h"
42f11eb2	37	#include "ssh2.h"
8efc0c15	38	#include "buffer.h"
	39	#include "packet.h"
	40	#include "channels.h"
7e7327a1	41	#include "compat.h"
42f11eb2	42	#include "log.h"
8efc0c15	43
f048f3e2	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:
f2107e97	53	* CLOSE ->
f2107e97	54	* <- CLOSE_CONFIRM
f048f3e2	55	*
f048f3e2	56	* 1.5: uses variations of:
f2107e97	57	* IEOF ->
	58	* <- OCLOSE
	59	* <- IEOF
	60	* OCLOSE ->
	61	* i.e. both sides have to close the channel
f048f3e2	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	*/
1b73841d	69
7e7327a1	70	/* functions manipulating channel states */
8efc0c15	71	/*
5260325f	72	* EVENTS update channel input/output states execute ACTIONS
8efc0c15	73	*/
7e7327a1	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 *);
50c96367	81	static void chan_send_eow2(Channel *);
7e7327a1	82
7e7327a1	83	/* helper */
396c147e	84	static void chan_shutdown_write(Channel *);
396c147e	85	static void chan_shutdown_read(Channel *);
7e7327a1	86
368e9dfc	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);
d7ac5f18	95	debug2("channel %d: input %s -> %s", c->self, istates[c->istate],
368e9dfc	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);
d7ac5f18	104	debug2("channel %d: output %s -> %s", c->self, ostates[c->ostate],
368e9dfc	105	ostates[next]);
	106	c->ostate = next;
	107	}
	108
7e7327a1	109	/*
	110	* SSH1 specific implementation of event functions
	111	*/
	112
	113	static void
	114	chan_rcvd_oclose1(Channel *c)
5260325f	115	{
d7ac5f18	116	debug2("channel %d: rcvd oclose", c->self);
5260325f	117	switch (c->istate) {
8efc0c15	118	case CHAN_INPUT_WAIT_OCLOSE:
368e9dfc	119	chan_set_istate(c, CHAN_INPUT_CLOSED);
8efc0c15	120	break;
8efc0c15	121	case CHAN_INPUT_OPEN:
8efc0c15	122	chan_shutdown_read(c);
7e7327a1	123	chan_send_ieof1(c);
368e9dfc	124	chan_set_istate(c, CHAN_INPUT_CLOSED);
48e671d5	125	break;
	126	case CHAN_INPUT_WAIT_DRAIN:
	127	/* both local read_failed and remote write_failed */
7e7327a1	128	chan_send_ieof1(c);
368e9dfc	129	chan_set_istate(c, CHAN_INPUT_CLOSED);
8efc0c15	130	break;
8efc0c15	131	default:
f048f3e2	132	error("channel %d: protocol error: rcvd_oclose for istate %d",
7e7327a1	133	c->self, c->istate);
48e671d5	134	return;
8efc0c15	135	}
8efc0c15	136	}
70bef40e	137	void
70bef40e	138	chan_read_failed(Channel *c)
5260325f	139	{
d7ac5f18	140	debug2("channel %d: read failed", c->self);
5260325f	141	switch (c->istate) {
8efc0c15	142	case CHAN_INPUT_OPEN:
8efc0c15	143	chan_shutdown_read(c);
368e9dfc	144	chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
8efc0c15	145	break;
8efc0c15	146	default:
f048f3e2	147	error("channel %d: chan_read_failed for istate %d",
7e7327a1	148	c->self, c->istate);
8efc0c15	149	break;
	150	}
	151	}
70bef40e	152	void
70bef40e	153	chan_ibuf_empty(Channel *c)
5260325f	154	{
d7ac5f18	155	debug2("channel %d: ibuf empty", c->self);
5260325f	156	if (buffer_len(&c->input)) {
f048f3e2	157	error("channel %d: chan_ibuf_empty for non empty buffer",
7e7327a1	158	c->self);
8efc0c15	159	return;
8efc0c15	160	}
5260325f	161	switch (c->istate) {
8efc0c15	162	case CHAN_INPUT_WAIT_DRAIN:
3057c23b	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	}
8efc0c15	171	break;
8efc0c15	172	default:
f048f3e2	173	error("channel %d: chan_ibuf_empty for istate %d",
7e7327a1	174	c->self, c->istate);
8efc0c15	175	break;
	176	}
	177	}
7e7327a1	178	static void
7e7327a1	179	chan_rcvd_ieof1(Channel *c)
5260325f	180	{
d7ac5f18	181	debug2("channel %d: rcvd ieof", c->self);
5260325f	182	switch (c->ostate) {
8efc0c15	183	case CHAN_OUTPUT_OPEN:
368e9dfc	184	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
8efc0c15	185	break;
8efc0c15	186	case CHAN_OUTPUT_WAIT_IEOF:
368e9dfc	187	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
8efc0c15	188	break;
8efc0c15	189	default:
f048f3e2	190	error("channel %d: protocol error: rcvd_ieof for ostate %d",
7e7327a1	191	c->self, c->ostate);
8efc0c15	192	break;
	193	}
	194	}
7e7327a1	195	static void
7e7327a1	196	chan_write_failed1(Channel *c)
5260325f	197	{
d7ac5f18	198	debug2("channel %d: write failed", c->self);
5260325f	199	switch (c->ostate) {
8efc0c15	200	case CHAN_OUTPUT_OPEN:
1e5e896c	201	chan_shutdown_write(c);
7e7327a1	202	chan_send_oclose1(c);
368e9dfc	203	chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
8efc0c15	204	break;
8efc0c15	205	case CHAN_OUTPUT_WAIT_DRAIN:
1e5e896c	206	chan_shutdown_write(c);
7e7327a1	207	chan_send_oclose1(c);
368e9dfc	208	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
8efc0c15	209	break;
8efc0c15	210	default:
f048f3e2	211	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	212	c->self, c->ostate);
8efc0c15	213	break;
	214	}
	215	}
70bef40e	216	void
70bef40e	217	chan_obuf_empty(Channel *c)
5260325f	218	{
d7ac5f18	219	debug2("channel %d: obuf empty", c->self);
5260325f	220	if (buffer_len(&c->output)) {
f048f3e2	221	error("channel %d: chan_obuf_empty for non empty buffer",
7e7327a1	222	c->self);
8efc0c15	223	return;
8efc0c15	224	}
5260325f	225	switch (c->ostate) {
8efc0c15	226	case CHAN_OUTPUT_WAIT_DRAIN:
1e5e896c	227	chan_shutdown_write(c);
3057c23b	228	if (!compat20)
3057c23b	229	chan_send_oclose1(c);
368e9dfc	230	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
8efc0c15	231	break;
8efc0c15	232	default:
f048f3e2	233	error("channel %d: internal error: obuf_empty for ostate %d",
7e7327a1	234	c->self, c->ostate);
8efc0c15	235	break;
	236	}
	237	}
8efc0c15	238	static void
7e7327a1	239	chan_send_ieof1(Channel *c)
5260325f	240	{
d7ac5f18	241	debug2("channel %d: send ieof", c->self);
5260325f	242	switch (c->istate) {
8efc0c15	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:
f048f3e2	250	error("channel %d: cannot send ieof for istate %d",
7e7327a1	251	c->self, c->istate);
8efc0c15	252	break;
	253	}
	254	}
	255	static void
7e7327a1	256	chan_send_oclose1(Channel *c)
5260325f	257	{
d7ac5f18	258	debug2("channel %d: send oclose", c->self);
5260325f	259	switch (c->ostate) {
8efc0c15	260	case CHAN_OUTPUT_OPEN:
8efc0c15	261	case CHAN_OUTPUT_WAIT_DRAIN:
9c50edcf	262	buffer_clear(&c->output);
8efc0c15	263	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	264	packet_put_int(c->remote_id);
	265	packet_send();
	266	break;
	267	default:
f048f3e2	268	error("channel %d: cannot send oclose for ostate %d",
184eed6a	269	c->self, c->ostate);
8efc0c15	270	break;
	271	}
	272	}
5260325f	273
7e7327a1	274	/*
	275	* the same for SSH2
	276	*/
8efc0c15	277	static void
668a91b7	278	chan_rcvd_close2(Channel *c)
5260325f	279	{
d7ac5f18	280	debug2("channel %d: rcvd close", c->self);
7e7327a1	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 */
368e9dfc	286	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
368e9dfc	287	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	288	return;
	289	}
	290	switch (c->ostate) {
	291	case CHAN_OUTPUT_OPEN:
f048f3e2	292	/*
	293	* wait until a data from the channel is consumed if a CLOSE
	294	* is received
	295	*/
368e9dfc	296	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
7e7327a1	297	break;
	298	}
	299	switch (c->istate) {
	300	case CHAN_INPUT_OPEN:
7e7327a1	301	chan_shutdown_read(c);
668a91b7	302	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	303	break;
7e7327a1	304	case CHAN_INPUT_WAIT_DRAIN:
7e7327a1	305	chan_send_eof2(c);
668a91b7	306	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	307	break;
7e7327a1	308	}
8efc0c15	309	}
50c96367	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	}
8efc0c15	321	static void
668a91b7	322	chan_rcvd_eof2(Channel *c)
5260325f	323	{
d7ac5f18	324	debug2("channel %d: rcvd eof", c->self);
d2296ed7	325	c->flags \|= CHAN_EOF_RCVD;
368e9dfc	326	if (c->ostate == CHAN_OUTPUT_OPEN)
368e9dfc	327	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
8efc0c15	328	}
7e7327a1	329	static void
	330	chan_write_failed2(Channel *c)
	331	{
d7ac5f18	332	debug2("channel %d: write failed", c->self);
7e7327a1	333	switch (c->ostate) {
7e7327a1	334	case CHAN_OUTPUT_OPEN:
7e7327a1	335	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	336	chan_shutdown_write(c);
4d92dbc1	337	if (strcmp(c->ctype, "session") == 0)
4d92dbc1	338	chan_send_eow2(c);
368e9dfc	339	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
7e7327a1	340	break;
7e7327a1	341	default:
f048f3e2	342	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	343	c->self, c->ostate);
	344	break;
	345	}
	346	}
	347	static void
7e7327a1	348	chan_send_eof2(Channel *c)
7e7327a1	349	{
d7ac5f18	350	debug2("channel %d: send eof", c->self);
7e7327a1	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();
d2296ed7	356	c->flags \|= CHAN_EOF_SENT;
7e7327a1	357	break;
7e7327a1	358	default:
f048f3e2	359	error("channel %d: cannot send eof for istate %d",
7e7327a1	360	c->self, c->istate);
	361	break;
	362	}
	363	}
	364	static void
	365	chan_send_close2(Channel *c)
	366	{
d7ac5f18	367	debug2("channel %d: send close", c->self);
7e7327a1	368	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
7e7327a1	369	c->istate != CHAN_INPUT_CLOSED) {
f048f3e2	370	error("channel %d: cannot send close for istate/ostate %d/%d",
7e7327a1	371	c->self, c->istate, c->ostate);
7e7327a1	372	} else if (c->flags & CHAN_CLOSE_SENT) {
f048f3e2	373	error("channel %d: already sent close", c->self);
7e7327a1	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	}
50c96367	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	}
72bd2fca	390	if (!(datafellows & SSH_NEW_OPENSSH))
72bd2fca	391	return;
50c96367	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	}
ee55dacf	398
	399	/* shared */
	400
70bef40e	401	void
	402	chan_rcvd_ieof(Channel *c)
	403	{
	404	if (compat20)
	405	chan_rcvd_eof2(c);
	406	else
	407	chan_rcvd_ieof1(c);
32e7d71f	408	if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
7203d6bb	409	buffer_len(&c->output) == 0 &&
d2296ed7	410	!CHANNEL_EFD_OUTPUT_ACTIVE(c))
32e7d71f	411	chan_obuf_empty(c);
70bef40e	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
719fc62f	430	void
	431	chan_mark_dead(Channel *c)
	432	{
6fd8622b	433	c->type = SSH_CHANNEL_ZOMBIE;
719fc62f	434	}
719fc62f	435
ee55dacf	436	int
ca75d7de	437	chan_is_dead(Channel *c, int do_send)
5260325f	438	{
6fd8622b	439	if (c->type == SSH_CHANNEL_ZOMBIE) {
d7ac5f18	440	debug2("channel %d: zombie", c->self);
719fc62f	441	return 1;
6fd8622b	442	}
ee55dacf	443	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	444	return 0;
	445	if (!compat20) {
d7ac5f18	446	debug2("channel %d: is dead", c->self);
ee55dacf	447	return 1;
ee55dacf	448	}
d2296ed7	449	if ((datafellows & SSH_BUG_EXTEOF) &&
	450	c->extended_usage == CHAN_EXTENDED_WRITE &&
	451	c->efd != -1 &&
	452	buffer_len(&c->extended) > 0) {
875ec275	453	debug2("channel %d: active efd: %d len %d",
875ec275	454	c->self, c->efd, buffer_len(&c->extended));
d2296ed7	455	return 0;
	456	}
	457	if (!(c->flags & CHAN_CLOSE_SENT)) {
ca75d7de	458	if (do_send) {
d2296ed7	459	chan_send_close2(c);
	460	} else {
	461	/* channel would be dead if we sent a close */
	462	if (c->flags & CHAN_CLOSE_RCVD) {
d7ac5f18	463	debug2("channel %d: almost dead",
d2296ed7	464	c->self);
d2296ed7	465	return 1;
418e724c	466	}
7e7327a1	467	}
d2296ed7	468	}
	469	if ((c->flags & CHAN_CLOSE_SENT) &&
	470	(c->flags & CHAN_CLOSE_RCVD)) {
d7ac5f18	471	debug2("channel %d: is dead", c->self);
d2296ed7	472	return 1;
8efc0c15	473	}
ee55dacf	474	return 0;
8efc0c15	475	}
7e7327a1	476
7e7327a1	477	/* helper */
	478	static void
	479	chan_shutdown_write(Channel *c)
	480	{
9c50edcf	481	buffer_clear(&c->output);
7e7327a1	482	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	483	return;
	484	/* shutdown failure is allowed if write failed already */
d7ac5f18	485	debug2("channel %d: close_write", c->self);
7e7327a1	486	if (c->sock != -1) {
7e7327a1	487	if (shutdown(c->sock, SHUT_WR) < 0)
d7ac5f18	488	debug2("channel %d: chan_shutdown_write: "
92d0164c	489	"shutdown() failed for fd %d: %.100s",
7e7327a1	490	c->self, c->sock, strerror(errno));
7e7327a1	491	} else {
489aa2e9	492	if (channel_close_fd(&c->wfd) < 0)
bbe88b6d	493	logit("channel %d: chan_shutdown_write: "
92d0164c	494	"close() failed for fd %d: %.100s",
7e7327a1	495	c->self, c->wfd, strerror(errno));
7e7327a1	496	}
	497	}
	498	static void
	499	chan_shutdown_read(Channel *c)
	500	{
	501	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
	502	return;
d7ac5f18	503	debug2("channel %d: close_read", c->self);
7e7327a1	504	if (c->sock != -1) {
2b87da3b	505	/*
47670e77	506	* shutdown(sock, SHUT_READ) may return ENOTCONN if the
47670e77	507	* write side has been closed already. (bug on Linux)
f49df8e9	508	* HP-UX may return ENOTCONN also.
47670e77	509	*/
47670e77	510	if (shutdown(c->sock, SHUT_RD) < 0
f49df8e9	511	&& errno != ENOTCONN)
f048f3e2	512	error("channel %d: chan_shutdown_read: "
92d0164c	513	"shutdown() failed for fd %d [i%d o%d]: %.100s",
f048f3e2	514	c->self, c->sock, c->istate, c->ostate,
1b73841d	515	strerror(errno));
7e7327a1	516	} else {
489aa2e9	517	if (channel_close_fd(&c->rfd) < 0)
bbe88b6d	518	logit("channel %d: chan_shutdown_read: "
92d0164c	519	"close() failed for fd %d: %.100s",
7e7327a1	520	c->self, c->rfd, strerror(errno));
7e7327a1	521	}
8efc0c15	522	}