If a mux started with ControlPersist then later has a forwarding added using
mux proxy connection and the forwarding was used, then when the mux proxy
session terminates, the mux master process will send a channel close to the
server with a bad channel ID and crash the connection.
This was caused by my stupidly reusing c->remote_id for mux channel
associations when I should have just added another member to struct channel.
ok markus@
OpenBSD-Commit-ID: c9f474e0124e3fe456c5e43749b97d75e65b82b2
This makes ssh/sshd more strict in handling non-compliant peers that
send more data than the advertised channel window allows. Previously
the additional data would be silently discarded. This change will
cause ssh/sshd to terminate the connection if the channel window is
exceeded by more than a small grace allowance.
ok markus@
OpenBSD-Commit-ID: 811e21b41831eba3dd7f67b3d409a438f20d3037
obfuscation, only consider enabling it when a channel with a tty is open.
Avoids turning on the obfucation when X11 forwarding only is in use,
which slows it right down. Reported by Roger Marsh
OpenBSD-Commit-ID: c292f738db410f729190f92de100c39ec931a4f1
whether channel data was enqueued. Will be used to improve keystroke timing
obfuscation. Problem spotted by / tested by naddy@
OpenBSD-Commit-ID: f9776c7b0065ba7c3bbe50431fd3b629f44314d0
INT_MAX. Fixes sign compare warnings systems with 32-bit time_t due to type
promotion. OK djm@
OpenBSD-Commit-ID: 48081e9ad35705c5f1705711704a4c2ff94e87b7
Use time_t instead of u_int for remaining x11 timeout checks for 64bit
time_t safety. From Coverity CIDs 405197 and 405028, ok djm@
OpenBSD-Commit-ID: 356685bfa1fc3d81bd95722d3fc47101cc1a4972
exactly the flags that ssh started with and don't just clobber them with
zero, as this could also remove the append flag from the set;
bz3523; ok dtucker@
OpenBSD-Commit-ID: 1336b03e881db7564a4b66014eb24c5230e9a0c0
This adds a sshd_config ChannelTimeouts directive that allows channels that
have not seen traffic in a configurable interval to be automatically closed.
Different timeouts may be applied to session, X11, agent and TCP forwarding
channels.
Note: this only affects channels over an opened SSH connection and not
the connection itself. Most clients close the connection when their channels
go away, with a notable exception being ssh(1) in multiplexing mode.
ok markus dtucker
OpenBSD-Commit-ID: ae8bba3ed9d9f95ff2e2dc8dcadfa36b48e6c0b8
This sets an "extended" channel type after channel creation (e.g.
"session:subsystem:sftp") that will be used for setting channel inactivity
timeouts.
ok markus dtucker
OpenBSD-Commit-ID: 42564aa92345045b4a74300528f960416a15d4ca
This will forcibly close an open channel by simulating read/write errors,
draining the IO buffers and calling the detach function.
Previously the detach function was only ever called during channel garbage
collection, but there was no way to signal the user of a channel (e.g.
session.c) that its channel was being closed deliberately (vs. by the
usual state-machine logic). So this adds an extra "force" argument to the
channel cleanup callback to indicate this condition.
ok markus dtucker
OpenBSD-Commit-ID: 23052707a42bdc62fda2508636e624afd466324b
comment accordingly. As remote_name is not modified, it can be const as
well. From Martin Vahlensieck
OpenBSD-Commit-ID: e4e10dc8dc9f40c166ea5a8e991942bedc75a76a
data in the channel buffer. Introduce more exact packing of channel fds into
the pollfd array. fixes bz3405 and bz3411; ok deraadt@ markus@
OpenBSD-Commit-ID: 06740737849c9047785622ad5d472cb6a3907d10
a fd directly into the transport input buffer.
Use this in the client and server mainloops to avoid unnecessary
copying. It also lets us use a more greedy read size without penalty.
Yields a 2-3% performance gain on cipher-speed.sh (in a fairly
unscientific test tbf)
feedback dtucker@ ok markus@
OpenBSD-Commit-ID: df4112125bf79d8e38e79a77113e1b373078e632
select() to poll() by moving FD_SET construction out of channel handlers into
separate functions. ok markus
OpenBSD-Commit-ID: 937fbf2a4de12b19fb9d5168424e206124807027
ssh(1) needs to set file descriptors to non-blocking mode to operate
but it was not restoring the original state on exit. This could cause
problems with fds shared with other programs via the shell, e.g.
> $ cat > test.sh << _EOF
> #!/bin/sh
> {
> ssh -Fnone -oLogLevel=verbose ::1 hostname
> cat /usr/share/dict/words
> } | sleep 10
> _EOF
> $ ./test.sh
> Authenticated to ::1 ([::1]:22).
> Transferred: sent 2352, received 2928 bytes, in 0.1 seconds
> Bytes per second: sent 44338.9, received 55197.4
> cat: stdout: Resource temporarily unavailable
This restores the blocking status for fds 0,1,2 (stdio) before ssh(1)
abandons/closes them.
This was reported as bz3280 and GHPR246; ok dtucker@
OpenBSD-Commit-ID: 8cc67346f05aa85a598bddf2383fcfcc3aae61ce
when peer advertises a large window but is slow to consume the data we send
(e.g. because of a slow network)
reported by Pierre-Yves David
fix with & ok markus@
OpenBSD-Commit-ID: 1452771f5e5e768876d3bfe2544e3866d6ade216
disposition of channel's extended (stderr) fd; makes debugging some things a
bit easier. No behaviour change.
OpenBSD-Commit-ID: 483eb6467dc7d5dbca8eb109c453e7a43075f7ce
addresses may be listened on when the client requests remote forwarding (ssh
-R).
This is the converse of the existing PermitOpen directive and this
includes some refactoring to share much of its implementation.
feedback and ok markus@
OpenBSD-Commit-ID: 15a931238c61a3f2ac74ea18a98c933e358e277f
Add 'reverse' dynamic forwarding which combines dynamic
forwarding (-D) with remote forwarding (-R) where the remote-forwarded port
expects SOCKS-requests.
The SSH server code is unchanged and the parsing happens at the SSH
clients side. Thus the full SOCKS-request is sent over the forwarded
channel and the client parses c->output. Parsing happens in
channel_before_prepare_select(), _before_ the select bitmask is
computed in the pre[] handlers, but after network input processing
in the post[] handlers.
help and ok djm@
Upstream-ID: aa25a6a3851064f34fe719e0bf15656ad5a64b89
Make remote channel ID a u_int
Previously we tracked the remote channel IDs in an int, but this is
strictly incorrect: the wire protocol uses uint32 and there is nothing
in-principle stopping a SSH implementation from sending, say, 0xffff0000.
In practice everyone numbers their channels sequentially, so this has
never been a problem.
ok markus@
Upstream-ID: b9f4cd3dc53155b4a5c995c0adba7da760d03e73
refactor channels.c
Move static state to a "struct ssh_channels" that is allocated at
runtime and tracked as a member of struct ssh.
Explicitly pass "struct ssh" to all channels functions.
Replace use of the legacy packet APIs in channels.c.
Rework sshd_config PermitOpen handling: previously the configuration
parser would call directly into the channels layer. After the refactor
this is not possible, as the channels structures are allocated at
connection time and aren't available when the configuration is parsed.
The server config parser now tracks PermitOpen itself and explicitly
configures the channels code later.
ok markus@
Upstream-ID: 11828f161656b965cc306576422613614bea2d8f
Return true reason for port forwarding failures where
feasible rather than always "administratively prohibited". bz#2674, ok djm@
Upstream-ID: d901d9887951774e604ca970e1827afaaef9e419
Remove channel_input_port_forward_request(); the only caller
was the recently-removed SSH1 server code so it's now dead code. ok markus@
Upstream-ID: 05453983230a1f439562535fec2818f63f297af9
ssh proxy mux mode (-O proxy; idea from Simon Tatham): - mux
client speaks the ssh-packet protocol directly over unix-domain socket. - mux
server acts as a proxy, translates channel IDs and relays to the server. - no
filedescriptor passing necessary. - combined with unix-domain forwarding it's
even possible to run mux client and server on different machines. feedback
& ok djm@
Upstream-ID: 666a2fb79f58e5c50e246265fb2b9251e505c25b
[PROTOCOL auth-options.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c]
[auth-rsa.c auth.c auth1.c auth2-hostbased.c auth2-kbdint.c auth2-none.c]
[auth2-passwd.c auth2-pubkey.c auth2.c canohost.c channels.c channels.h]
[clientloop.c misc.c misc.h monitor.c mux.c packet.c readconf.c]
[readconf.h servconf.c servconf.h serverloop.c session.c ssh-agent.c]
[ssh.c ssh_config.5 sshconnect.c sshconnect1.c sshconnect2.c sshd.c]
[sshd_config.5 sshlogin.c]
Add support for Unix domain socket forwarding. A remote TCP port
may be forwarded to a local Unix domain socket and vice versa or
both ends may be a Unix domain socket. This is a reimplementation
of the streamlocal patches by William Ahern from:
http://www.25thandclement.com/~william/projects/streamlocal.html
OK djm@ markus@
blocking connecting socket will clear any stored errno that might
otherwise have been retrievable via getsockopt(). A hack to limit writes
to TTYs on AIX was triggering this. Since only AIX needs the hack, wrap
it in an #ifdef. Diagnosis and patch from Ivo Raisr.
[channels.c channels.h clientloop.c]
Add an "ABANDONED" channel state and use for mux sessions that are
disconnected via the ~. escape sequence. Channels in this state will
be able to close if the server responds, but do not count as active channels.
This means that if you ~. all of the mux clients when using ControlPersist
on a broken network, the backgrounded mux master will exit when the
Control Persist time expires rather than hanging around indefinitely.
bz#1917, also reported and tested by tedu@. ok djm@ markus@.
[mux.c readconf.h channels.h compat.h compat.c ssh.c readconf.c channels.c version.h]
unbreak remote portforwarding with dynamic allocated listen ports:
1) send the actual listen port in the open message (instead of 0).
this allows multiple forwardings with a dynamic listen port
2) update the matching permit-open entry, so we can identify where
to connect to
report: den at skbkontur.ru and P. Szczygielski
feedback and ok djm@
