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
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
some arbitrary value < 0. errno is only updated in this case. Change all
(most?) callers of syscalls to follow this better, and let's see if this
strictness helps us in the future.
OpenBSD-Commit-ID: 48081f00db7518e3b712a49dca06efc2a5428075
close the local extended read fd (stderr) along with the regular read fd
(stdout). Avoids weird stuck processed in multiplexing mode.
Report and analysis by Nelson Elhage and Geoffrey Thomas in bz#2863
ok dtucker@ markus@
OpenBSD-Commit-ID: a48a2467fe938de4de69d2e7193d5fa701f12ae9
disposition of channel's extended (stderr) fd; makes debugging some things a
bit easier. No behaviour change.
OpenBSD-Commit-ID: 483eb6467dc7d5dbca8eb109c453e7a43075f7ce
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
[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@
[compat.c compat.h nchan.c ssh.c]
only send eow and no-more-sessions requests to openssh 5 and newer;
fixes interop problems with broken ssh v2 implementations; ok djm@
[channels.h clientloop.c nchan.c serverloop.c]
unbreak
ssh -2 localhost od /bin/ls | true
ignoring SIGPIPE by adding a new channel message (EOW) that signals
the peer that we're not interested in any data it might send.
fixes bz #85; discussion, debugging and ok djm@
[auth-options.c auth1.c channels.c channels.h clientloop.c gss-serv.c]
[monitor.c monitor_wrap.c nchan.c servconf.c serverloop.c session.c]
[ssh.c sshd.c]
Implement a channel success/failure status confirmation callback
mechanism. Each channel maintains a queue of callbacks, which will
be drained in order (RFC4253 guarantees confirm messages are not
reordered within an channel).
Also includes a abandonment callback to clean up if a channel is
closed without sending confirmation messages. This probably
shouldn't happen in compliant implementations, but it could be
abused to leak memory.
ok markus@ (as part of a larger diff)
[auth-rsa.c auth2-gss.c auth2-pubkey.c authfile.c canohost.c channels.c
cipher.c dns.c kex.c monitor.c monitor_fdpass.c monitor_wrap.c
monitor_wrap.h nchan.c packet.c progressmeter.c scp.c sftp-server.c sftp.c
ssh-gss.h ssh-keygen.c ssh.c sshconnect.c sshconnect1.c sshlogin.c
sshpty.c]
make ssh -Wshadow clean, no functional changes
markus@ ok
There are also some portable-specific -Wshadow warnings to be fixed in
monitor.c and montior_wrap.c.
[channels.c channels.h compat.c compat.h nchan.c]
don't send stderr data after EOF, accept this from older known (broken)
sshd servers only, fixes http://bugzilla.mindrot.org/show_bug.cgi?id=179
- markus@cvs.openbsd.org 2001/10/10 22:18:47
[channels.c channels.h clientloop.c nchan.c serverloop.c]
[session.c session.h]
try to keep channels open until an exit-status message is sent.
don't kill the login shells if the shells stdin/out/err is closed.
this should now work:
ssh -2n localhost 'exec > /dev/null 2>&1; sleep 10; exit 5'; echo ?
[channels.c channels.h clientloop.c nchan.c serverloop.c]
keep track of both maxfd and the size of the malloc'ed fdsets.
update maxfd if maxfd gets closed.
djm@openbsd.org
deraadt@openbsd.org
Damien Miller
Darren Tucker
Ben Lindstrom
Kevin Steves