--- /dev/null
+/*
+ * Copyright (c) 1999, 2000, 2001 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"
+RCSID("$OpenBSD: nchan.c,v 1.32 2001/10/10 22:18:47 markus Exp $");
+
+#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
+ */
+/* events concerning the INPUT from socket for channel (istate) */
+chan_event_fn *chan_rcvd_oclose = NULL;
+chan_event_fn *chan_read_failed = NULL;
+chan_event_fn *chan_ibuf_empty = NULL;
+/* events concerning the OUTPUT from channel for socket (ostate) */
+chan_event_fn *chan_rcvd_ieof = NULL;
+chan_event_fn *chan_write_failed = NULL;
+chan_event_fn *chan_obuf_empty = NULL;
+/*
+ * 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 *);
+
+/* helper */
+static void chan_shutdown_write(Channel *);
+static void chan_shutdown_read(Channel *);
+
+/*
+ * SSH1 specific implementation of event functions
+ */
+
+static void
+chan_rcvd_oclose1(Channel *c)
+{
+ debug("channel %d: rcvd oclose", c->self);
+ switch (c->istate) {
+ case CHAN_INPUT_WAIT_OCLOSE:
+ debug("channel %d: input wait_oclose -> closed", c->self);
+ c->istate = CHAN_INPUT_CLOSED;
+ break;
+ case CHAN_INPUT_OPEN:
+ debug("channel %d: input open -> closed", c->self);
+ chan_shutdown_read(c);
+ chan_send_ieof1(c);
+ c->istate = CHAN_INPUT_CLOSED;
+ break;
+ case CHAN_INPUT_WAIT_DRAIN:
+ /* both local read_failed and remote write_failed */
+ log("channel %d: input drain -> closed", c->self);
+ chan_send_ieof1(c);
+ c->istate = CHAN_INPUT_CLOSED;
+ break;
+ default:
+ error("channel %d: protocol error: rcvd_oclose for istate %d",
+ c->self, c->istate);
+ return;
+ }
+}
+static void
+chan_read_failed_12(Channel *c)
+{
+ debug("channel %d: read failed", c->self);
+ switch (c->istate) {
+ case CHAN_INPUT_OPEN:
+ debug("channel %d: input open -> drain", c->self);
+ chan_shutdown_read(c);
+ c->istate = CHAN_INPUT_WAIT_DRAIN;
+#if 0
+ if (buffer_len(&c->input) == 0) {
+ debug("channel %d: input: no drain shortcut", c->self);
+ chan_ibuf_empty(c);
+ }
+#endif
+ break;
+ default:
+ error("channel %d: chan_read_failed for istate %d",
+ c->self, c->istate);
+ break;
+ }
+}
+static void
+chan_ibuf_empty1(Channel *c)
+{
+ debug("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:
+ debug("channel %d: input drain -> wait_oclose", c->self);
+ chan_send_ieof1(c);
+ c->istate = 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)
+{
+ debug("channel %d: rcvd ieof", c->self);
+ if (c->type != SSH_CHANNEL_OPEN) {
+ debug("channel %d: non-open", c->self);
+ if (c->istate == CHAN_INPUT_OPEN) {
+ debug("channel %d: non-open: input open -> wait_oclose",
+ c->self);
+ chan_shutdown_read(c);
+ chan_send_ieof1(c);
+ c->istate = CHAN_INPUT_WAIT_OCLOSE;
+ } else {
+ error("channel %d: non-open: istate %d != open",
+ c->self, c->istate);
+ }
+ if (c->ostate == CHAN_OUTPUT_OPEN) {
+ debug("channel %d: non-open: output open -> closed",
+ c->self);
+ chan_send_oclose1(c);
+ c->ostate = CHAN_OUTPUT_CLOSED;
+ } else {
+ error("channel %d: non-open: ostate %d != open",
+ c->self, c->ostate);
+ }
+ return;
+ }
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ debug("channel %d: output open -> drain", c->self);
+ c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+ break;
+ case CHAN_OUTPUT_WAIT_IEOF:
+ debug("channel %d: output wait_ieof -> closed", c->self);
+ c->ostate = 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)
+{
+ debug("channel %d: write failed", c->self);
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ debug("channel %d: output open -> wait_ieof", c->self);
+ chan_send_oclose1(c);
+ c->ostate = CHAN_OUTPUT_WAIT_IEOF;
+ break;
+ case CHAN_OUTPUT_WAIT_DRAIN:
+ debug("channel %d: output wait_drain -> closed", c->self);
+ chan_send_oclose1(c);
+ c->ostate = CHAN_OUTPUT_CLOSED;
+ break;
+ default:
+ error("channel %d: chan_write_failed for ostate %d",
+ c->self, c->ostate);
+ break;
+ }
+}
+static void
+chan_obuf_empty1(Channel *c)
+{
+ debug("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:
+ debug("channel %d: output drain -> closed", c->self);
+ chan_send_oclose1(c);
+ c->ostate = 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)
+{
+ debug("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)
+{
+ debug("channel %d: send oclose", c->self);
+ 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("channel %d: cannot send oclose for ostate %d",
+ c->self, c->ostate);
+ break;
+ }
+}
+
+/*
+ * the same for SSH2
+ */
+static void
+chan_rcvd_oclose2(Channel *c)
+{
+ debug("channel %d: rcvd close", c->self);
+ 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 */
+ c->ostate = CHAN_OUTPUT_CLOSED;
+ c->istate = 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
+ */
+ debug("channel %d: output open -> drain", c->self);
+ c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+ break;
+ }
+ switch (c->istate) {
+ case CHAN_INPUT_OPEN:
+ debug("channel %d: input open -> closed", c->self);
+ chan_shutdown_read(c);
+ break;
+ case CHAN_INPUT_WAIT_DRAIN:
+ debug("channel %d: input drain -> closed", c->self);
+ chan_send_eof2(c);
+ break;
+ }
+ c->istate = CHAN_INPUT_CLOSED;
+}
+static void
+chan_ibuf_empty2(Channel *c)
+{
+ debug("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:
+ debug("channel %d: input drain -> closed", c->self);
+ if (!(c->flags & CHAN_CLOSE_SENT))
+ chan_send_eof2(c);
+ c->istate = CHAN_INPUT_CLOSED;
+ break;
+ default:
+ error("channel %d: chan_ibuf_empty for istate %d",
+ c->self, c->istate);
+ break;
+ }
+}
+static void
+chan_rcvd_ieof2(Channel *c)
+{
+ debug("channel %d: rcvd eof", c->self);
+ if (c->ostate == CHAN_OUTPUT_OPEN) {
+ debug("channel %d: output open -> drain", c->self);
+ c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+ }
+}
+static void
+chan_write_failed2(Channel *c)
+{
+ debug("channel %d: write failed", c->self);
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ debug("channel %d: output open -> closed", c->self);
+ chan_shutdown_write(c); /* ?? */
+ c->ostate = CHAN_OUTPUT_CLOSED;
+ break;
+ case CHAN_OUTPUT_WAIT_DRAIN:
+ debug("channel %d: output drain -> closed", c->self);
+ chan_shutdown_write(c);
+ c->ostate = CHAN_OUTPUT_CLOSED;
+ break;
+ default:
+ error("channel %d: chan_write_failed for ostate %d",
+ c->self, c->ostate);
+ break;
+ }
+}
+static void
+chan_obuf_empty2(Channel *c)
+{
+ debug("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:
+ debug("channel %d: output drain -> closed", c->self);
+ chan_shutdown_write(c);
+ c->ostate = CHAN_OUTPUT_CLOSED;
+ break;
+ default:
+ error("channel %d: chan_obuf_empty for ostate %d",
+ c->self, c->ostate);
+ break;
+ }
+}
+static void
+chan_send_eof2(Channel *c)
+{
+ debug("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();
+ break;
+ default:
+ error("channel %d: cannot send eof for istate %d",
+ c->self, c->istate);
+ break;
+ }
+}
+static void
+chan_send_close2(Channel *c)
+{
+ debug("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;
+ }
+}
+
+/* shared */
+
+void
+chan_mark_dead(Channel *c)
+{
+ c->type = SSH_CHANNEL_ZOMBIE;
+}
+
+int
+chan_is_dead(Channel *c, int send)
+{
+ if (c->type == SSH_CHANNEL_ZOMBIE) {
+ debug("channel %d: zombie", c->self);
+ return 1;
+ }
+ if (c->istate != CHAN_INPUT_CLOSED || c->ostate != CHAN_OUTPUT_CLOSED)
+ return 0;
+ if (!compat20) {
+ debug("channel %d: is dead", c->self);
+ return 1;
+ }
+ /*
+ * we have to delay the close message if the efd (for stderr) is
+ * still active
+ */
+ if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
+ buffer_len(&c->extended) > 0)
+#if 0
+ || ((c->extended_usage == CHAN_EXTENDED_READ) &&
+ c->efd != -1)
+#endif
+ ) {
+ debug2("channel %d: active efd: %d len %d type %s",
+ c->self, c->efd, buffer_len(&c->extended),
+ c->extended_usage==CHAN_EXTENDED_READ ?
+ "read": "write");
+ } else {
+ if (!(c->flags & CHAN_CLOSE_SENT)) {
+ if (send) {
+ chan_send_close2(c);
+ } else {
+ /* channel would be dead if we sent a close */
+ if (c->flags & CHAN_CLOSE_RCVD) {
+ debug("channel %d: almost dead",
+ c->self);
+ return 1;
+ }
+ }
+ }
+ if ((c->flags & CHAN_CLOSE_SENT) &&
+ (c->flags & CHAN_CLOSE_RCVD)) {
+ debug("channel %d: is dead", c->self);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+void
+chan_init_iostates(Channel *c)
+{
+ c->ostate = CHAN_OUTPUT_OPEN;
+ c->istate = CHAN_INPUT_OPEN;
+ c->flags = 0;
+}
+
+/* init */
+void
+chan_init(void)
+{
+ if (compat20) {
+ chan_rcvd_oclose = chan_rcvd_oclose2;
+ chan_read_failed = chan_read_failed_12;
+ chan_ibuf_empty = chan_ibuf_empty2;
+
+ chan_rcvd_ieof = chan_rcvd_ieof2;
+ chan_write_failed = chan_write_failed2;
+ chan_obuf_empty = chan_obuf_empty2;
+ } else {
+ chan_rcvd_oclose = chan_rcvd_oclose1;
+ chan_read_failed = chan_read_failed_12;
+ chan_ibuf_empty = chan_ibuf_empty1;
+
+ chan_rcvd_ieof = chan_rcvd_ieof1;
+ chan_write_failed = chan_write_failed1;
+ chan_obuf_empty = chan_obuf_empty1;
+ }
+}
+
+/* helper */
+static void
+chan_shutdown_write(Channel *c)
+{
+ buffer_consume(&c->output, buffer_len(&c->output));
+ if (compat20 && c->type == SSH_CHANNEL_LARVAL)
+ return;
+ /* shutdown failure is allowed if write failed already */
+ debug("channel %d: close_write", c->self);
+ if (c->sock != -1) {
+ if (shutdown(c->sock, SHUT_WR) < 0)
+ debug("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)
+ log("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;
+ debug("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)
+ log("channel %d: chan_shutdown_read: "
+ "close() failed for fd%d: %.100s",
+ c->self, c->rfd, strerror(errno));
+ }
+}
andersk / gssapi-openssh.git / blobdiff