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/*
* 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 1.5 2000/01/14 04:45:50 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);
static void chan_delete_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;
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;
}
chan_delete_if_full_closed(c);
}
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;
chan_delete_if_full_closed(c);
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;
chan_delete_if_full_closed(c);
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;
chan_delete_if_full_closed(c);
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));
}
static 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;
}
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