- djm@cvs.openbsd.org 2010/01/26 01:28:35
[channels.c channels.h clientloop.c clientloop.h mux.c nchan.c ssh.c]
rewrite ssh(1) multiplexing code to a more sensible protocol.
The new multiplexing code uses channels for the listener and
accepted control sockets to make the mux master non-blocking, so
no stalls when processing messages from a slave.
avoid use of fatal() in mux master protocol parsing so an errant slave
process cannot take down a running master.
implement requesting of port-forwards over multiplexed sessions. Any
port forwards requested by the slave are added to those the master has
established.
add support for stdio forwarding ("ssh -W host:port ...") in mux slaves.
document master/slave mux protocol so that other tools can use it to
control a running ssh(1). Note: there are no guarantees that this
protocol won't be incompatibly changed (though it is versioned).
feedback Salvador Fandino, dtucker@
channel changes ok markus@
diff --git a/nchan.c b/nchan.c
index 160445e..20f6a2f 100644
--- a/nchan.c
+++ b/nchan.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: nchan.c,v 1.62 2008/11/07 18:50:18 stevesk Exp $ */
+/* $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.
*
@@ -161,7 +161,7 @@
switch (c->istate) {
case CHAN_INPUT_WAIT_DRAIN:
if (compat20) {
- if (!(c->flags & CHAN_CLOSE_SENT))
+ if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_LOCAL)))
chan_send_eof2(c);
chan_set_istate(c, CHAN_INPUT_CLOSED);
} else {
@@ -278,9 +278,12 @@
chan_rcvd_close2(Channel *c)
{
debug2("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->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);
@@ -302,11 +305,13 @@
chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
case CHAN_INPUT_WAIT_DRAIN:
- chan_send_eof2(c);
+ if (!(c->flags & CHAN_LOCAL))
+ chan_send_eof2(c);
chan_set_istate(c, CHAN_INPUT_CLOSED);
break;
}
}
+
void
chan_rcvd_eow(Channel *c)
{
@@ -454,6 +459,10 @@
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);