[channels.c channels.h clientloop.h mux.c ssh.c]
support for cancelling local and remote port forwards via the multiplex
socket. Use ssh -O cancel -L xx:xx:xx -R yy:yy:yy user@host" to request
the cancellation of the specified forwardings; ok markus@
[channels.c channels.h clientloop.c clientloop.h mux.c ssh.c]
hook up a channel confirm callback to warn the user then requested X11
forwarding was refused by the server; ok markus@
[PROTOCOL.mux clientloop.c clientloop.h mux.c]
improve our behaviour when TTY allocation fails: if we are in
RequestTTY=auto mode (the default), then do not treat at TTY
allocation error as fatal but rather just restore the local TTY
to cooked mode and continue. This is more graceful on devices that
never allocate TTYs.
If RequestTTY is set to "yes" or "force", then failure to allocate
a TTY is fatal.
ok markus@
[clientloop.c mux.c readconf.c readconf.h ssh.c ssh_config.5]
Add a RequestTTY ssh_config option to allow configuration-based
control over tty allocation (like -t/-T); ok markus@
[PROTOCOL.mux clientloop.c clientloop.h mux.c ssh.1 ssh.c]
allow graceful shutdown of multiplexing: request that a mux server
removes its listener socket and refuse future multiplexing requests;
ok markus@
[mux.c]
"atomically" create the listening mux socket by binding it on a temorary
name and then linking it into position after listen() has succeeded.
this allows the mux clients to determine that the server socket is
either ready or stale without races. stale server sockets are now
automatically removed
ok deraadt
[ssh.c]
log the hostname and address that we connected to at LogLevel=verbose
after authentication is successful to mitigate "phishing" attacks by
servers with trusted keys that accept authentication silently and
automatically before presenting fake password/passphrase prompts;
"nice!" markus@
[channels.c mux.c readconf.c readconf.h ssh.h]
bz#1327: remove hardcoded limit of 100 permitopen clauses and port
forwards per direction; ok markus@ stevesk@
[mux.c]
Correct sizing of object to be allocated by calloc(), replacing
sizeof(state) with sizeof(*state). This worked by accident since
the struct contained a single int at present, but could have broken
in the future. patch from hyc AT symas.com
[PROTOCOL.mux clientloop.h mux.c readconf.c readconf.h ssh.1 ssh.c]
mux support for remote forwarding with dynamic port allocation,
use with
LPORT=`ssh -S muxsocket -R0:localhost:25 -O forward somehost`
feedback and ok djm@
[channels.c channels.h mux.c ssh.c]
Pause the mux channel while waiting for reply from aynch callbacks.
Prevents misordering of replies if new requests arrive while waiting.
Extend channel open confirm callback to allow signalling failure
conditions as well as success. Use this to 1) fix a memory leak, 2)
start using the above pause mechanism and 3) delay sending a success/
failure message on mux slave session open until we receive a reply from
the server.
motivated by and with feedback from markus@
[mux.c]
set "detach_close" flag when registering channel cleanup callbacks.
This causes the channel to close normally when its fds close and
hangs when terminating a mux slave using ~. bz#1758; ok markus@
[mux.c]
fix bug introduced in mux rewrite:
In a mux master, when a socket to a mux slave closes before its server
session (as may occur when the slave has been signalled), gracefully
close the server session rather than deleting its channel immediately.
A server may have more messages on that channel to send (e.g. an exit
message) that will fatal() the client if they are sent to a channel that
has been prematurely deleted.
spotted by imorgan AT nas.nasa.gov
[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@
[mux.c sshpty.h clientloop.c sshtty.c]
quell tc[gs]etattr warnings when forcing a tty (ssh -tt), since we
usually don't actually have a tty to read/set; bz#1686 ok dtucker@
[mux.c]
fall back to creating a new TCP connection on most multiplexing errors
(socket connect fail, invalid version, refused permittion, corrupted
messages, etc.); bz #1329 ok dtucker@
[clientloop.h channels.h clientloop.c channels.c mux.c]
The multiplexing escape char handler commit last night introduced a
small memory leak per session; plug it.
[clientloop.h mux.c channels.c clientloop.c channels.h]
Enable ~ escapes for multiplex slave sessions; give each channel
its own escape state and hook the escape filters up to muxed
channels. bz #1331
Mux slaves do not currently support the ~^Z and ~& escapes.
NB. this change cranks the mux protocol version, so a new ssh
mux client will not be able to connect to a running old ssh
mux master.
ok dtucker@
[openbsd-compat/fmt_scaled.c openbsd-compat/openbsd-compat.h]
Fix compilation on Linux, including pulling in fmt_scaled(3)
implementation from OpenBSD's libutil.
[clientloop.c clientloop.h ssh.c mux.c]
tidy up session multiplexing code, moving it into its own file and
making the function names more consistent - making ssh.c and
clientloop.c a fair bit more readable.
ok markus@
Damien Miller
Darren Tucker