[openssh.git] / nchan.c

/* $OpenBSD: nchan.c,v 1.63 2010/01/26 01:28:35 djm 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_LOCAL)))
				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_LOCAL)) {
		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:
		if (!(c->flags & CHAN_LOCAL))
			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_LOCAL) {
		debug2("channel %d: is dead (local)", c->self);
		return 1;
	}		
	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
a858eae9	1	/* $OpenBSD: nchan.c,v 1.63 2010/01/26 01:28:35 djm 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) {
a858eae9	164	if (!(c->flags & (CHAN_CLOSE_SENT\|CHAN_LOCAL)))
3057c23b	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);
a858eae9	281	if (!(c->flags & CHAN_LOCAL)) {
	282	if (c->flags & CHAN_CLOSE_RCVD)
	283	error("channel %d: protocol error: close rcvd twice",
	284	c->self);
	285	c->flags \|= CHAN_CLOSE_RCVD;
	286	}
7e7327a1	287	if (c->type == SSH_CHANNEL_LARVAL) {
7e7327a1	288	/* tear down larval channels immediately */
368e9dfc	289	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
368e9dfc	290	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	291	return;
	292	}
	293	switch (c->ostate) {
	294	case CHAN_OUTPUT_OPEN:
f048f3e2	295	/*
	296	* wait until a data from the channel is consumed if a CLOSE
	297	* is received
	298	*/
368e9dfc	299	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
7e7327a1	300	break;
	301	}
	302	switch (c->istate) {
	303	case CHAN_INPUT_OPEN:
7e7327a1	304	chan_shutdown_read(c);
668a91b7	305	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	306	break;
7e7327a1	307	case CHAN_INPUT_WAIT_DRAIN:
a858eae9	308	if (!(c->flags & CHAN_LOCAL))
a858eae9	309	chan_send_eof2(c);
668a91b7	310	chan_set_istate(c, CHAN_INPUT_CLOSED);
7e7327a1	311	break;
7e7327a1	312	}
8efc0c15	313	}
a858eae9	314
50c96367	315	void
	316	chan_rcvd_eow(Channel *c)
	317	{
	318	debug2("channel %d: rcvd eow", c->self);
	319	switch (c->istate) {
	320	case CHAN_INPUT_OPEN:
	321	chan_shutdown_read(c);
	322	chan_set_istate(c, CHAN_INPUT_CLOSED);
	323	break;
	324	}
	325	}
8efc0c15	326	static void
668a91b7	327	chan_rcvd_eof2(Channel *c)
5260325f	328	{
d7ac5f18	329	debug2("channel %d: rcvd eof", c->self);
d2296ed7	330	c->flags \|= CHAN_EOF_RCVD;
368e9dfc	331	if (c->ostate == CHAN_OUTPUT_OPEN)
368e9dfc	332	chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
8efc0c15	333	}
7e7327a1	334	static void
	335	chan_write_failed2(Channel *c)
	336	{
d7ac5f18	337	debug2("channel %d: write failed", c->self);
7e7327a1	338	switch (c->ostate) {
7e7327a1	339	case CHAN_OUTPUT_OPEN:
7e7327a1	340	case CHAN_OUTPUT_WAIT_DRAIN:
7e7327a1	341	chan_shutdown_write(c);
4d92dbc1	342	if (strcmp(c->ctype, "session") == 0)
4d92dbc1	343	chan_send_eow2(c);
368e9dfc	344	chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
7e7327a1	345	break;
7e7327a1	346	default:
f048f3e2	347	error("channel %d: chan_write_failed for ostate %d",
7e7327a1	348	c->self, c->ostate);
	349	break;
	350	}
	351	}
	352	static void
7e7327a1	353	chan_send_eof2(Channel *c)
7e7327a1	354	{
d7ac5f18	355	debug2("channel %d: send eof", c->self);
7e7327a1	356	switch (c->istate) {
	357	case CHAN_INPUT_WAIT_DRAIN:
	358	packet_start(SSH2_MSG_CHANNEL_EOF);
	359	packet_put_int(c->remote_id);
	360	packet_send();
d2296ed7	361	c->flags \|= CHAN_EOF_SENT;
7e7327a1	362	break;
7e7327a1	363	default:
f048f3e2	364	error("channel %d: cannot send eof for istate %d",
7e7327a1	365	c->self, c->istate);
	366	break;
	367	}
	368	}
	369	static void
	370	chan_send_close2(Channel *c)
	371	{
d7ac5f18	372	debug2("channel %d: send close", c->self);
7e7327a1	373	if (c->ostate != CHAN_OUTPUT_CLOSED \|\|
7e7327a1	374	c->istate != CHAN_INPUT_CLOSED) {
f048f3e2	375	error("channel %d: cannot send close for istate/ostate %d/%d",
7e7327a1	376	c->self, c->istate, c->ostate);
7e7327a1	377	} else if (c->flags & CHAN_CLOSE_SENT) {
f048f3e2	378	error("channel %d: already sent close", c->self);
7e7327a1	379	} else {
	380	packet_start(SSH2_MSG_CHANNEL_CLOSE);
	381	packet_put_int(c->remote_id);
	382	packet_send();
	383	c->flags \|= CHAN_CLOSE_SENT;
	384	}
	385	}
50c96367	386	static void
	387	chan_send_eow2(Channel *c)
	388	{
	389	debug2("channel %d: send eow", c->self);
	390	if (c->ostate == CHAN_OUTPUT_CLOSED) {
	391	error("channel %d: must not sent eow on closed output",
	392	c->self);
	393	return;
	394	}
72bd2fca	395	if (!(datafellows & SSH_NEW_OPENSSH))
72bd2fca	396	return;
50c96367	397	packet_start(SSH2_MSG_CHANNEL_REQUEST);
	398	packet_put_int(c->remote_id);
	399	packet_put_cstring("eow@openssh.com");
	400	packet_put_char(0);
	401	packet_send();
	402	}
ee55dacf	403
	404	/* shared */
	405
70bef40e	406	void
	407	chan_rcvd_ieof(Channel *c)
	408	{
	409	if (compat20)
	410	chan_rcvd_eof2(c);
	411	else
	412	chan_rcvd_ieof1(c);
32e7d71f	413	if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
7203d6bb	414	buffer_len(&c->output) == 0 &&
d2296ed7	415	!CHANNEL_EFD_OUTPUT_ACTIVE(c))
32e7d71f	416	chan_obuf_empty(c);
70bef40e	417	}
	418	void
	419	chan_rcvd_oclose(Channel *c)
	420	{
	421	if (compat20)
	422	chan_rcvd_close2(c);
	423	else
	424	chan_rcvd_oclose1(c);
	425	}
	426	void
	427	chan_write_failed(Channel *c)
	428	{
	429	if (compat20)
	430	chan_write_failed2(c);
	431	else
	432	chan_write_failed1(c);
	433	}
	434
719fc62f	435	void
	436	chan_mark_dead(Channel *c)
	437	{
6fd8622b	438	c->type = SSH_CHANNEL_ZOMBIE;
719fc62f	439	}
719fc62f	440
ee55dacf	441	int
ca75d7de	442	chan_is_dead(Channel *c, int do_send)
5260325f	443	{
6fd8622b	444	if (c->type == SSH_CHANNEL_ZOMBIE) {
d7ac5f18	445	debug2("channel %d: zombie", c->self);
719fc62f	446	return 1;
6fd8622b	447	}
ee55dacf	448	if (c->istate != CHAN_INPUT_CLOSED \|\| c->ostate != CHAN_OUTPUT_CLOSED)
	449	return 0;
	450	if (!compat20) {
d7ac5f18	451	debug2("channel %d: is dead", c->self);
ee55dacf	452	return 1;
ee55dacf	453	}
d2296ed7	454	if ((datafellows & SSH_BUG_EXTEOF) &&
	455	c->extended_usage == CHAN_EXTENDED_WRITE &&
	456	c->efd != -1 &&
	457	buffer_len(&c->extended) > 0) {
875ec275	458	debug2("channel %d: active efd: %d len %d",
875ec275	459	c->self, c->efd, buffer_len(&c->extended));
d2296ed7	460	return 0;
d2296ed7	461	}
a858eae9	462	if (c->flags & CHAN_LOCAL) {
	463	debug2("channel %d: is dead (local)", c->self);
	464	return 1;
	465	}
d2296ed7	466	if (!(c->flags & CHAN_CLOSE_SENT)) {
ca75d7de	467	if (do_send) {
d2296ed7	468	chan_send_close2(c);
	469	} else {
	470	/* channel would be dead if we sent a close */
	471	if (c->flags & CHAN_CLOSE_RCVD) {
d7ac5f18	472	debug2("channel %d: almost dead",
d2296ed7	473	c->self);
d2296ed7	474	return 1;
418e724c	475	}
7e7327a1	476	}
d2296ed7	477	}
	478	if ((c->flags & CHAN_CLOSE_SENT) &&
	479	(c->flags & CHAN_CLOSE_RCVD)) {
d7ac5f18	480	debug2("channel %d: is dead", c->self);
d2296ed7	481	return 1;
8efc0c15	482	}
ee55dacf	483	return 0;
8efc0c15	484	}
7e7327a1	485
7e7327a1	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 */
d7ac5f18	494	debug2("channel %d: close_write", c->self);
7e7327a1	495	if (c->sock != -1) {
7e7327a1	496	if (shutdown(c->sock, SHUT_WR) < 0)
d7ac5f18	497	debug2("channel %d: chan_shutdown_write: "
92d0164c	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)
bbe88b6d	502	logit("channel %d: chan_shutdown_write: "
92d0164c	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;
d7ac5f18	512	debug2("channel %d: close_read", c->self);
7e7327a1	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: "
92d0164c	522	"shutdown() failed for fd %d [i%d o%d]: %.100s",
f048f3e2	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)
bbe88b6d	527	logit("channel %d: chan_shutdown_read: "
92d0164c	528	"close() failed for fd %d: %.100s",
7e7327a1	529	c->self, c->rfd, strerror(errno));
7e7327a1	530	}
8efc0c15	531	}