Put ssh back into the repository
Change-Id: I23324372188fa6ed3f93a32b84365f5df6367590
diff --git a/nchan.c b/nchan.c
new file mode 100644
index 0000000..20f6a2f
--- /dev/null
+++ b/nchan.c
@@ -0,0 +1,531 @@
+/* $OpenBSD: nchan.c,v 1.63 2010/01/26 01:28:35 djm Exp $ */
+/*
+ * Copyright (c) 1999, 2000, 2001, 2002 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"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <errno.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "openbsd-compat/sys-queue.h"
+#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
+ */
+/*
+ * 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 *);
+static void chan_send_eow2(Channel *);
+
+/* helper */
+static void chan_shutdown_write(Channel *);
+static void chan_shutdown_read(Channel *);
+
+static char *ostates[] = { "open", "drain", "wait_ieof", "closed" };
+static char *istates[] = { "open", "drain", "wait_oclose", "closed" };
+
+static void
+chan_set_istate(Channel *c, u_int next)
+{
+ if (c->istate > CHAN_INPUT_CLOSED || next > CHAN_INPUT_CLOSED)
+ fatal("chan_set_istate: bad state %d -> %d", c->istate, next);
+ debug2("channel %d: input %s -> %s", c->self, istates[c->istate],
+ istates[next]);
+ c->istate = next;
+}
+static void
+chan_set_ostate(Channel *c, u_int next)
+{
+ if (c->ostate > CHAN_OUTPUT_CLOSED || next > CHAN_OUTPUT_CLOSED)
+ fatal("chan_set_ostate: bad state %d -> %d", c->ostate, next);
+ debug2("channel %d: output %s -> %s", c->self, ostates[c->ostate],
+ ostates[next]);
+ c->ostate = next;
+}
+
+/*
+ * SSH1 specific implementation of event functions
+ */
+
+static void
+chan_rcvd_oclose1(Channel *c)
+{
+ debug2("channel %d: rcvd oclose", c->self);
+ switch (c->istate) {
+ case CHAN_INPUT_WAIT_OCLOSE:
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ break;
+ case CHAN_INPUT_OPEN:
+ chan_shutdown_read(c);
+ chan_send_ieof1(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ break;
+ case CHAN_INPUT_WAIT_DRAIN:
+ /* both local read_failed and remote write_failed */
+ chan_send_ieof1(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ break;
+ default:
+ error("channel %d: protocol error: rcvd_oclose for istate %d",
+ c->self, c->istate);
+ return;
+ }
+}
+void
+chan_read_failed(Channel *c)
+{
+ debug2("channel %d: read failed", c->self);
+ switch (c->istate) {
+ case CHAN_INPUT_OPEN:
+ chan_shutdown_read(c);
+ chan_set_istate(c, CHAN_INPUT_WAIT_DRAIN);
+ break;
+ default:
+ error("channel %d: chan_read_failed for istate %d",
+ c->self, c->istate);
+ break;
+ }
+}
+void
+chan_ibuf_empty(Channel *c)
+{
+ debug2("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:
+ if (compat20) {
+ if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_LOCAL)))
+ chan_send_eof2(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ } else {
+ chan_send_ieof1(c);
+ chan_set_istate(c, 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)
+{
+ debug2("channel %d: rcvd ieof", c->self);
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
+ break;
+ case CHAN_OUTPUT_WAIT_IEOF:
+ chan_set_ostate(c, 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)
+{
+ debug2("channel %d: write failed", c->self);
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ chan_shutdown_write(c);
+ chan_send_oclose1(c);
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_IEOF);
+ break;
+ case CHAN_OUTPUT_WAIT_DRAIN:
+ chan_shutdown_write(c);
+ chan_send_oclose1(c);
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
+ break;
+ default:
+ error("channel %d: chan_write_failed for ostate %d",
+ c->self, c->ostate);
+ break;
+ }
+}
+void
+chan_obuf_empty(Channel *c)
+{
+ debug2("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:
+ chan_shutdown_write(c);
+ if (!compat20)
+ chan_send_oclose1(c);
+ chan_set_ostate(c, 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)
+{
+ debug2("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)
+{
+ debug2("channel %d: send oclose", c->self);
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ case CHAN_OUTPUT_WAIT_DRAIN:
+ buffer_clear(&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_close2(Channel *c)
+{
+ debug2("channel %d: rcvd close", c->self);
+ if (!(c->flags & CHAN_LOCAL)) {
+ 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 */
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
+ chan_set_istate(c, 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
+ */
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
+ break;
+ }
+ switch (c->istate) {
+ case CHAN_INPUT_OPEN:
+ chan_shutdown_read(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ break;
+ case CHAN_INPUT_WAIT_DRAIN:
+ if (!(c->flags & CHAN_LOCAL))
+ chan_send_eof2(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ break;
+ }
+}
+
+void
+chan_rcvd_eow(Channel *c)
+{
+ debug2("channel %d: rcvd eow", c->self);
+ switch (c->istate) {
+ case CHAN_INPUT_OPEN:
+ chan_shutdown_read(c);
+ chan_set_istate(c, CHAN_INPUT_CLOSED);
+ break;
+ }
+}
+static void
+chan_rcvd_eof2(Channel *c)
+{
+ debug2("channel %d: rcvd eof", c->self);
+ c->flags |= CHAN_EOF_RCVD;
+ if (c->ostate == CHAN_OUTPUT_OPEN)
+ chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
+}
+static void
+chan_write_failed2(Channel *c)
+{
+ debug2("channel %d: write failed", c->self);
+ switch (c->ostate) {
+ case CHAN_OUTPUT_OPEN:
+ case CHAN_OUTPUT_WAIT_DRAIN:
+ chan_shutdown_write(c);
+ if (strcmp(c->ctype, "session") == 0)
+ chan_send_eow2(c);
+ chan_set_ostate(c, CHAN_OUTPUT_CLOSED);
+ break;
+ default:
+ error("channel %d: chan_write_failed for ostate %d",
+ c->self, c->ostate);
+ break;
+ }
+}
+static void
+chan_send_eof2(Channel *c)
+{
+ debug2("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();
+ c->flags |= CHAN_EOF_SENT;
+ break;
+ default:
+ error("channel %d: cannot send eof for istate %d",
+ c->self, c->istate);
+ break;
+ }
+}
+static void
+chan_send_close2(Channel *c)
+{
+ debug2("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;
+ }
+}
+static void
+chan_send_eow2(Channel *c)
+{
+ debug2("channel %d: send eow", c->self);
+ if (c->ostate == CHAN_OUTPUT_CLOSED) {
+ error("channel %d: must not sent eow on closed output",
+ c->self);
+ return;
+ }
+ if (!(datafellows & SSH_NEW_OPENSSH))
+ return;
+ packet_start(SSH2_MSG_CHANNEL_REQUEST);
+ packet_put_int(c->remote_id);
+ packet_put_cstring("eow@openssh.com");
+ packet_put_char(0);
+ packet_send();
+}
+
+/* shared */
+
+void
+chan_rcvd_ieof(Channel *c)
+{
+ if (compat20)
+ chan_rcvd_eof2(c);
+ else
+ chan_rcvd_ieof1(c);
+ if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
+ buffer_len(&c->output) == 0 &&
+ !CHANNEL_EFD_OUTPUT_ACTIVE(c))
+ chan_obuf_empty(c);
+}
+void
+chan_rcvd_oclose(Channel *c)
+{
+ if (compat20)
+ chan_rcvd_close2(c);
+ else
+ chan_rcvd_oclose1(c);
+}
+void
+chan_write_failed(Channel *c)
+{
+ if (compat20)
+ chan_write_failed2(c);
+ else
+ chan_write_failed1(c);
+}
+
+void
+chan_mark_dead(Channel *c)
+{
+ c->type = SSH_CHANNEL_ZOMBIE;
+}
+
+int
+chan_is_dead(Channel *c, int do_send)
+{
+ if (c->type == SSH_CHANNEL_ZOMBIE) {
+ debug2("channel %d: zombie", c->self);
+ return 1;
+ }
+ if (c->istate != CHAN_INPUT_CLOSED || c->ostate != CHAN_OUTPUT_CLOSED)
+ return 0;
+ if (!compat20) {
+ debug2("channel %d: is dead", c->self);
+ return 1;
+ }
+ if ((datafellows & SSH_BUG_EXTEOF) &&
+ c->extended_usage == CHAN_EXTENDED_WRITE &&
+ c->efd != -1 &&
+ buffer_len(&c->extended) > 0) {
+ debug2("channel %d: active efd: %d len %d",
+ c->self, c->efd, buffer_len(&c->extended));
+ return 0;
+ }
+ if (c->flags & CHAN_LOCAL) {
+ debug2("channel %d: is dead (local)", c->self);
+ return 1;
+ }
+ if (!(c->flags & CHAN_CLOSE_SENT)) {
+ if (do_send) {
+ chan_send_close2(c);
+ } else {
+ /* channel would be dead if we sent a close */
+ if (c->flags & CHAN_CLOSE_RCVD) {
+ debug2("channel %d: almost dead",
+ c->self);
+ return 1;
+ }
+ }
+ }
+ if ((c->flags & CHAN_CLOSE_SENT) &&
+ (c->flags & CHAN_CLOSE_RCVD)) {
+ debug2("channel %d: is dead", c->self);
+ return 1;
+ }
+ return 0;
+}
+
+/* helper */
+static void
+chan_shutdown_write(Channel *c)
+{
+ buffer_clear(&c->output);
+ if (compat20 && c->type == SSH_CHANNEL_LARVAL)
+ return;
+ /* shutdown failure is allowed if write failed already */
+ debug2("channel %d: close_write", c->self);
+ if (c->sock != -1) {
+ if (shutdown(c->sock, SHUT_WR) < 0)
+ debug2("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)
+ logit("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;
+ debug2("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)
+ logit("channel %d: chan_shutdown_read: "
+ "close() failed for fd %d: %.100s",
+ c->self, c->rfd, strerror(errno));
+ }
+}