[openssh.git] / nchan.c

/*
 * Copyright (c) 1999 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Markus Friedl.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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("$Id$");

#include "ssh.h"

#include "buffer.h"
#include "packet.h"
#include "channels.h"
#include "nchan.h"

static void chan_send_ieof(Channel *c);
static void chan_send_oclose(Channel *c);
static void chan_shutdown_write(Channel *c);
static void chan_shutdown_read(Channel *c);
static void chan_delele_if_full_closed(Channel *c);

/*
 * EVENTS update channel input/output states execute ACTIONS
 */

/* events concerning the INPUT from socket for channel (istate) */
void
chan_rcvd_oclose(Channel *c)
{
	switch (c->istate) {
	case CHAN_INPUT_WAIT_OCLOSE:
		debug("channel %d: INPUT_WAIT_OCLOSE -> INPUT_CLOSED [rcvd OCLOSE]", c->self);
		c->istate = CHAN_INPUT_CLOSED;
		chan_delele_if_full_closed(c);
		break;
	case CHAN_INPUT_OPEN:
		debug("channel %d: INPUT_OPEN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
		chan_shutdown_read(c);
		chan_send_ieof(c);
		c->istate = CHAN_INPUT_CLOSED;
		chan_delele_if_full_closed(c);
		break;
	default:
		debug("protocol error: chan_rcvd_oclose %d for istate %d", c->self, c->istate);
		break;
	}
}
void
chan_read_failed(Channel *c)
{
	switch (c->istate) {
	case CHAN_INPUT_OPEN:
		debug("channel %d: INPUT_OPEN -> INPUT_WAIT_DRAIN [read failed]", c->self);
		chan_shutdown_read(c);
		c->istate = CHAN_INPUT_WAIT_DRAIN;
		break;
	default:
		debug("internal error: we do not read, but chan_read_failed %d for istate %d",
		      c->self, c->istate);
		break;
	}
}
void
chan_ibuf_empty(Channel *c)
{
	if (buffer_len(&c->input)) {
		debug("internal error: chan_ibuf_empty %d for non empty buffer", c->self);
		return;
	}
	switch (c->istate) {
	case CHAN_INPUT_WAIT_DRAIN:
		debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_WAIT_OCLOSE [inbuf empty, send IEOF]", c->self);
		chan_send_ieof(c);
		c->istate = CHAN_INPUT_WAIT_OCLOSE;
		break;
	default:
		debug("internal error: chan_ibuf_empty %d for istate %d", c->self, c->istate);
		break;
	}
}

/* events concerning the OUTPUT from channel for socket (ostate) */
void
chan_rcvd_ieof(Channel *c)
{
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_DRAIN [rvcd IEOF]", c->self);
		c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
		break;
	case CHAN_OUTPUT_WAIT_IEOF:
		debug("channel %d: OUTPUT_WAIT_IEOF -> OUTPUT_CLOSED [rvcd IEOF]", c->self);
		c->ostate = CHAN_OUTPUT_CLOSED;
		chan_delele_if_full_closed(c);
		break;
	default:
		debug("protocol error: chan_rcvd_ieof %d for ostate %d", c->self, c->ostate);
		break;
	}
}
void
chan_write_failed(Channel *c)
{
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
		debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_IEOF [write failed]", c->self);
		chan_send_oclose(c);
		c->ostate = CHAN_OUTPUT_WAIT_IEOF;
		break;
	case CHAN_OUTPUT_WAIT_DRAIN:
		debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [write failed]", c->self);
		chan_send_oclose(c);
		c->ostate = CHAN_OUTPUT_CLOSED;
		chan_delele_if_full_closed(c);
		break;
	default:
		debug("internal error: chan_write_failed %d for ostate %d", c->self, c->ostate);
		break;
	}
}
void
chan_obuf_empty(Channel *c)
{
	if (buffer_len(&c->output)) {
		debug("internal error: chan_obuf_empty %d for non empty buffer", c->self);
		return;
	}
	switch (c->ostate) {
	case CHAN_OUTPUT_WAIT_DRAIN:
		debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [obuf empty, send OCLOSE]", c->self);
		chan_send_oclose(c);
		c->ostate = CHAN_OUTPUT_CLOSED;
		chan_delele_if_full_closed(c);
		break;
	default:
		debug("internal error: chan_obuf_empty %d for ostate %d", c->self, c->ostate);
		break;
	}
}

/*
 * ACTIONS: should never update the channel states: c->istate or c->ostate
 */
static void
chan_send_ieof(Channel *c)
{
	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:
		debug("internal error: channel %d: cannot send IEOF for istate %d", c->self, c->istate);
		break;
	}
}
static void
chan_send_oclose(Channel *c)
{
	switch (c->ostate) {
	case CHAN_OUTPUT_OPEN:
	case CHAN_OUTPUT_WAIT_DRAIN:
		chan_shutdown_write(c);
		buffer_consume(&c->output, buffer_len(&c->output));
		packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
		packet_put_int(c->remote_id);
		packet_send();
		break;
	default:
		debug("internal error: channel %d: cannot send OCLOSE for ostate %d", c->self, c->istate);
		break;
	}
}

/* helper */
static void
chan_shutdown_write(Channel *c)
{
	/* shutdown failure is allowed if write failed already */
	debug("channel %d: shutdown_write", c->self);
	if (shutdown(c->sock, SHUT_WR) < 0)
		debug("chan_shutdown_write failed for #%d/fd%d: %.100s",
		      c->self, c->sock, strerror(errno));
}
static void
chan_shutdown_read(Channel *c)
{
	debug("channel %d: shutdown_read", c->self);
	if (shutdown(c->sock, SHUT_RD) < 0)
		error("chan_shutdown_read failed for #%d/fd%d: %.100s",
		      c->self, c->sock, strerror(errno));
}
static void
chan_delele_if_full_closed(Channel *c)
{
	if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
		debug("channel %d: closing", c->self);
		channel_free(c->self);
	}
}
void
chan_init_iostates(Channel *c)
{
	c->ostate = CHAN_OUTPUT_OPEN;
	c->istate = CHAN_INPUT_OPEN;
}
Commit	Line	Data
aa3378df	1	/*
	2	* Copyright (c) 1999 Markus Friedl. All rights reserved.
	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.
	12	* 3. All advertising materials mentioning features or use of this software
	13	* must display the following acknowledgement:
	14	* This product includes software developed by Markus Friedl.
	15	* 4. The name of the author may not be used to endorse or promote products
	16	* derived from this software without specific prior written permission.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	28	*/
	29
8efc0c15	30	#include "includes.h"
	31	RCSID("$Id$");
	32
	33	#include "ssh.h"
	34
	35	#include "buffer.h"
	36	#include "packet.h"
	37	#include "channels.h"
	38	#include "nchan.h"
	39
	40	static void chan_send_ieof(Channel *c);
	41	static void chan_send_oclose(Channel *c);
	42	static void chan_shutdown_write(Channel *c);
	43	static void chan_shutdown_read(Channel *c);
	44	static void chan_delele_if_full_closed(Channel *c);
	45
	46	/*
5260325f	47	* EVENTS update channel input/output states execute ACTIONS
8efc0c15	48	*/
5260325f	49
8efc0c15	50	/* events concerning the INPUT from socket for channel (istate) */
8efc0c15	51	void
5260325f	52	chan_rcvd_oclose(Channel *c)
	53	{
	54	switch (c->istate) {
8efc0c15	55	case CHAN_INPUT_WAIT_OCLOSE:
8efc0c15	56	debug("channel %d: INPUT_WAIT_OCLOSE -> INPUT_CLOSED [rcvd OCLOSE]", c->self);
5260325f	57	c->istate = CHAN_INPUT_CLOSED;
8efc0c15	58	chan_delele_if_full_closed(c);
	59	break;
	60	case CHAN_INPUT_OPEN:
	61	debug("channel %d: INPUT_OPEN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
	62	chan_shutdown_read(c);
	63	chan_send_ieof(c);
5260325f	64	c->istate = CHAN_INPUT_CLOSED;
8efc0c15	65	chan_delele_if_full_closed(c);
	66	break;
	67	default:
5260325f	68	debug("protocol error: chan_rcvd_oclose %d for istate %d", c->self, c->istate);
8efc0c15	69	break;
	70	}
	71	}
	72	void
5260325f	73	chan_read_failed(Channel *c)
	74	{
	75	switch (c->istate) {
8efc0c15	76	case CHAN_INPUT_OPEN:
	77	debug("channel %d: INPUT_OPEN -> INPUT_WAIT_DRAIN [read failed]", c->self);
	78	chan_shutdown_read(c);
5260325f	79	c->istate = CHAN_INPUT_WAIT_DRAIN;
8efc0c15	80	break;
	81	default:
	82	debug("internal error: we do not read, but chan_read_failed %d for istate %d",
5260325f	83	c->self, c->istate);
8efc0c15	84	break;
	85	}
	86	}
	87	void
5260325f	88	chan_ibuf_empty(Channel *c)
	89	{
	90	if (buffer_len(&c->input)) {
	91	debug("internal error: chan_ibuf_empty %d for non empty buffer", c->self);
8efc0c15	92	return;
8efc0c15	93	}
5260325f	94	switch (c->istate) {
8efc0c15	95	case CHAN_INPUT_WAIT_DRAIN:
	96	debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_WAIT_OCLOSE [inbuf empty, send IEOF]", c->self);
	97	chan_send_ieof(c);
5260325f	98	c->istate = CHAN_INPUT_WAIT_OCLOSE;
8efc0c15	99	break;
8efc0c15	100	default:
5260325f	101	debug("internal error: chan_ibuf_empty %d for istate %d", c->self, c->istate);
8efc0c15	102	break;
	103	}
	104	}
5260325f	105
8efc0c15	106	/* events concerning the OUTPUT from channel for socket (ostate) */
8efc0c15	107	void
5260325f	108	chan_rcvd_ieof(Channel *c)
	109	{
	110	switch (c->ostate) {
8efc0c15	111	case CHAN_OUTPUT_OPEN:
8efc0c15	112	debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_DRAIN [rvcd IEOF]", c->self);
5260325f	113	c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
8efc0c15	114	break;
	115	case CHAN_OUTPUT_WAIT_IEOF:
	116	debug("channel %d: OUTPUT_WAIT_IEOF -> OUTPUT_CLOSED [rvcd IEOF]", c->self);
5260325f	117	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	118	chan_delele_if_full_closed(c);
	119	break;
	120	default:
5260325f	121	debug("protocol error: chan_rcvd_ieof %d for ostate %d", c->self, c->ostate);
8efc0c15	122	break;
	123	}
	124	}
	125	void
5260325f	126	chan_write_failed(Channel *c)
	127	{
	128	switch (c->ostate) {
8efc0c15	129	case CHAN_OUTPUT_OPEN:
	130	debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_IEOF [write failed]", c->self);
	131	chan_send_oclose(c);
5260325f	132	c->ostate = CHAN_OUTPUT_WAIT_IEOF;
8efc0c15	133	break;
	134	case CHAN_OUTPUT_WAIT_DRAIN:
	135	debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [write failed]", c->self);
	136	chan_send_oclose(c);
5260325f	137	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	138	chan_delele_if_full_closed(c);
	139	break;
	140	default:
5260325f	141	debug("internal error: chan_write_failed %d for ostate %d", c->self, c->ostate);
8efc0c15	142	break;
	143	}
	144	}
	145	void
5260325f	146	chan_obuf_empty(Channel *c)
	147	{
	148	if (buffer_len(&c->output)) {
	149	debug("internal error: chan_obuf_empty %d for non empty buffer", c->self);
8efc0c15	150	return;
8efc0c15	151	}
5260325f	152	switch (c->ostate) {
8efc0c15	153	case CHAN_OUTPUT_WAIT_DRAIN:
	154	debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [obuf empty, send OCLOSE]", c->self);
	155	chan_send_oclose(c);
5260325f	156	c->ostate = CHAN_OUTPUT_CLOSED;
8efc0c15	157	chan_delele_if_full_closed(c);
	158	break;
	159	default:
5260325f	160	debug("internal error: chan_obuf_empty %d for ostate %d", c->self, c->ostate);
8efc0c15	161	break;
	162	}
	163	}
5260325f	164
8efc0c15	165	/*
5260325f	166	* ACTIONS: should never update the channel states: c->istate or c->ostate
8efc0c15	167	*/
8efc0c15	168	static void
5260325f	169	chan_send_ieof(Channel *c)
	170	{
	171	switch (c->istate) {
8efc0c15	172	case CHAN_INPUT_OPEN:
	173	case CHAN_INPUT_WAIT_DRAIN:
	174	packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
	175	packet_put_int(c->remote_id);
	176	packet_send();
	177	break;
	178	default:
5260325f	179	debug("internal error: channel %d: cannot send IEOF for istate %d", c->self, c->istate);
8efc0c15	180	break;
	181	}
	182	}
	183	static void
5260325f	184	chan_send_oclose(Channel *c)
	185	{
	186	switch (c->ostate) {
8efc0c15	187	case CHAN_OUTPUT_OPEN:
	188	case CHAN_OUTPUT_WAIT_DRAIN:
	189	chan_shutdown_write(c);
	190	buffer_consume(&c->output, buffer_len(&c->output));
	191	packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
	192	packet_put_int(c->remote_id);
	193	packet_send();
	194	break;
	195	default:
5260325f	196	debug("internal error: channel %d: cannot send OCLOSE for ostate %d", c->self, c->istate);
8efc0c15	197	break;
	198	}
	199	}
5260325f	200
8efc0c15	201	/* helper */
8efc0c15	202	static void
5260325f	203	chan_shutdown_write(Channel *c)
5260325f	204	{
aa3378df	205	/* shutdown failure is allowed if write failed already */
8efc0c15	206	debug("channel %d: shutdown_write", c->self);
5260325f	207	if (shutdown(c->sock, SHUT_WR) < 0)
aa3378df	208	debug("chan_shutdown_write failed for #%d/fd%d: %.100s",
5260325f	209	c->self, c->sock, strerror(errno));
8efc0c15	210	}
8efc0c15	211	static void
5260325f	212	chan_shutdown_read(Channel *c)
5260325f	213	{
8efc0c15	214	debug("channel %d: shutdown_read", c->self);
5260325f	215	if (shutdown(c->sock, SHUT_RD) < 0)
8efc0c15	216	error("chan_shutdown_read failed for #%d/fd%d: %.100s",
5260325f	217	c->self, c->sock, strerror(errno));
8efc0c15	218	}
8efc0c15	219	static void
5260325f	220	chan_delele_if_full_closed(Channel *c)
	221	{
	222	if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
8efc0c15	223	debug("channel %d: closing", c->self);
	224	channel_free(c->self);
	225	}
	226	}
	227	void
5260325f	228	chan_init_iostates(Channel *c)
	229	{
	230	c->ostate = CHAN_OUTPUT_OPEN;
	231	c->istate = CHAN_INPUT_OPEN;
8efc0c15	232	}