diff options
Diffstat (limited to 'crypto/openssh/nchan.c')
-rw-r--r-- | crypto/openssh/nchan.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/crypto/openssh/nchan.c b/crypto/openssh/nchan.c new file mode 100644 index 0000000..1f30a7c --- /dev/null +++ b/crypto/openssh/nchan.c @@ -0,0 +1,238 @@ +/* + * 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 1.10 2000/01/10 10:15:28 markus 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; +} |