nchan.c - security/openssh-library - Rivoreo Source Code Repositories

 /*
  * 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: nchan.c,v 1.6 2000/04/01 01:09:24 damien Exp $");

 #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);

 /*
  * 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;
 		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;
 		break;
 	case CHAN_INPUT_WAIT_DRAIN:
 		/* both local read_failed and remote write_failed  */
 		log("channel %d: INPUT_WAIT_DRAIN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
 		debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
 		chan_send_ieof(c);
 		c->istate = CHAN_INPUT_CLOSED;
 		break;
 	default:
 		error("protocol error: chan_rcvd_oclose %d for istate %d", c->self, c->istate);
 		return;
 	}
 }
 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:
 		error("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)) {
 		error("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:
 		error("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;
 		break;
 	default:
 		error("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;
 		break;
 	default:
 		error("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;
 		break;
 	default:
 		error("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:
 		error("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:
 		error("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 [i%d o%d]: %.100s",
 		      c->self, c->sock, c->istate, c->ostate, strerror(errno));
 }
 void
 chan_delete_if_full_closed(Channel *c)
 {
 	if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
 		debug("channel %d: full closed", c->self);
 		channel_free(c->self);
 	}
 }
 void
 chan_init_iostates(Channel *c)
 {
 	c->ostate = CHAN_OUTPUT_OPEN;
 	c->istate = CHAN_INPUT_OPEN;
 }
	/*
	* 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: nchan.c,v 1.6 2000/04/01 01:09:24 damien Exp $");

	#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);

	/*
	* 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;
	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;
	break;
	case CHAN_INPUT_WAIT_DRAIN:
	/* both local read_failed and remote write_failed */
	log("channel %d: INPUT_WAIT_DRAIN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
	debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
	chan_send_ieof(c);
	c->istate = CHAN_INPUT_CLOSED;
	break;
	default:
	error("protocol error: chan_rcvd_oclose %d for istate %d", c->self, c->istate);
	return;
	}
	}
	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:
	error("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)) {
	error("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:
	error("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;
	break;
	default:
	error("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;
	break;
	default:
	error("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;
	break;
	default:
	error("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:
	error("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:
	error("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 [i%d o%d]: %.100s",
	c->self, c->sock, c->istate, c->ostate, strerror(errno));
	}
	void
	chan_delete_if_full_closed(Channel *c)
	{
	if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
	debug("channel %d: full closed", c->self);
	channel_free(c->self);
	}
	}
	void
	chan_init_iostates(Channel *c)
	{
	c->ostate = CHAN_OUTPUT_OPEN;
	c->istate = CHAN_INPUT_OPEN;
	}