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
Add MAXIMUM(), MINIMUM(), and ROUNDUP() to misc.h, then
use those definitions rather than pulling <sys/param.h> and unknown namespace
pollution. ok djm markus dtucker
Upstream-ID: 712cafa816c9f012a61628b66b9fbd5687223fb8
Allow wildcard for PermitOpen hosts as well as ports.
bz#2582, patch from openssh at mzpqnxow.com and jjelen at redhat.com. ok
markus@
Upstream-ID: af0294e9b9394c4e16e991424ca0a47a7cc605f2
refactor canohost.c: move functions that cache results closer
to the places that use them (authn and session code). After this, no state is
cached in canohost.c
feedback and ok markus@
Upstream-ID: 5f2e4df88d4803fc8ec59ec53629105e23ce625e
Only check errno if read() has returned an error. EOF is
not an error. This fixes a problem where the mux master would sporadically
fail to notice that the client had exited. ok mikeb@ djm@
Upstream-ID: 3c2dadc21fac6ef64665688aac8a75fffd57ae53
fix some signed/unsigned integer type mismatches in
format strings; reported by Nicholas Lemonias
Upstream-ID: 78cd55420a0eef68c4095bdfddd1af84afe5f95c
fatal() when a remote window update causes the window
value to overflow. Reported by Georg Wicherski, ok markus@
Upstream-ID: ead397a9aceb3bf74ebfa5fcaf259d72e569f351
Fix math error in remote window calculations that causes
eventual stalls for datagram channels. Reported by Georg Wicherski, ok
markus@
Upstream-ID: be54059d11bf64e0d85061f7257f53067842e2ab
For "ssh -L 12345:/tmp/sock" don't fail with "No forward host
name." (we have a path, not a host name). Based on a diff from Jared
Yanovich. OK djm@
Upstream-ID: 2846b0a8c7de037e33657f95afbd282837fc213f
[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@
[channels.c]
allow explicit ::1 and 127.0.0.1 forwarding bind addresses when
GatewayPorts=no; allows client to choose address family;
bz#2222 ok markus@
when it is available. It takes into account time spent suspended,
thereby ensuring timeouts (e.g. for expiring agent keys) fire
correctly. bz#2228 reported by John Haxby
[authfile.c bufaux.c buffer.h channels.c krl.c mux.c packet.c packet.h]
[ssh-keygen.c]
buffer_get_string_ptr's return should be const to remind
callers that futzing with it will futz with the actual buffer
contents
[channels.c]
bz#2147: fix multiple remote forwardings with dynamically assigned
listen ports. In the s->c message to open the channel we were sending
zero (the magic number to request a dynamic port) instead of the actual
listen port. The client therefore had no way of discriminating between
them.
Diagnosis and fix by ronf AT timeheart.net
[channels.c]
bz#1297 - tell the client (via packet_send_debug) when their preferred
listen address has been overridden by the server's GatewayPorts;
ok dtucker@
[channels.c]
avoid unaligned access in code that reused a buffer to send a
struct in_addr in a reply; simpler just use use buffer_put_int();
from portable; spotted by and ok dtucker@
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@.
[ssh-agent.c clientloop.c misc.h packet.c progressmeter.c misc.c
channels.c sandbox-systrace.c]
Use clock_gettime(CLOCK_MONOTONIC ...) for ssh timers so that things like
keepalives and rekeying will work properly over clock steps. Suggested by
markus@, "looks good" djm@.
[auth-options.c channels.c servconf.c servconf.h serverloop.c session.c]
[sshd_config.5]
make AllowTcpForwarding accept "local" and "remote" in addition to its
current "yes"/"no" to allow the server to specify whether just local or
remote TCP forwarding is enabled. ok 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@
[channels.c auth-options.c servconf.c channels.h sshd.8]
Add wildcard support to PermitOpen, allowing things like "PermitOpen
localhost:*". bz #1857, ok djm markus.
[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@
[channels.c]
remove a debug() that pollutes stderr on client connecting to a server
in debug mode (channel_close_fds is called transitively from the session
code post-fork); bz#1719, ok dtucker
[channels.c]
Fix a trio of bugs in the local/remote window calculation for datagram
data channels (i.e. TunnelForward):
Calculate local_consumed correctly in channel_handle_wfd() by measuring
the delta to buffer_len(c->output) from when we start to when we finish.
The proximal problem here is that the output_filter we use in portable
modified the length of the dequeued datagram (to futz with the headers
for !OpenBSD).
In channel_output_poll(), don't enqueue datagrams that won't fit in the
peer's advertised packet size (highly unlikely to ever occur) or which
won't fit in the peer's remaining window (more likely).
In channel_input_data(), account for the 4-byte string header in
datagram packets that we accept from the peer and enqueue in c->output.
report, analysis and testing 2/3 cases from wierbows AT us.ibm.com;
"looks good" markus@
[auth-rsa.c channels.c jpake.c key.c misc.c misc.h monitor.c]
[packet.c ssh-rsa.c]
implement a timing_safe_cmp() function to compare memory without leaking
timing information by short-circuiting like memcmp() and use it for
some of the more sensitive comparisons (though nothing high-value was
readily attackable anyway); "looks ok" markus@
[channels.c session.c]
bz#1750: fix requirement for /dev/null inside ChrootDirectory for
internal-sftp accidentally introduced in r1.253 by removing the code
that opens and dup /dev/null to stderr and modifying the channels code
to read stderr but discard it instead; ok 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@
[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@
[channels.c]
fake local addr:port when stdio fowarding as some servers (Tectia at
least) validate that they are well-formed;
reported by imorgan AT nas.nasa.gov
ok dtucker
[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@
[ssh_config channels.c ssh.1 channels.h ssh.c]
Add a 'netcat mode' (ssh -W). This connects stdio on the client to a
single port forward on the server. This allows, for example, using ssh as
a ProxyCommand to route connections via intermediate servers.
bz #1618, man page help from jmc@, ok markus@
[channels.c ssh.1 servconf.c sshd_config.5 sshd.c channels.h servconf.h
ssh-keyscan.1 ssh-keyscan.c readconf.c sshconnect.c misc.c ssh.c
readconf.h scp.1 sftp.1 ssh_config.5 misc.h]
Remove RoutingDomain from ssh since it's now not needed. It can be
replaced with "route exec" or "nc -V" as a proxycommand. "route exec"
also ensures that trafic such as DNS lookups stays withing the specified
routingdomain. For example (from reyk):
# route -T 2 exec /usr/sbin/sshd
or inherited from the parent process
$ route -T 2 exec sh
$ ssh 10.1.2.3
ok deraadt@ markus@ stevesk@ reyk@
[channels.c channels.h]
fix race condition in x11/agent channel allocation: don't read after
the end of the select read/write fdset and make sure a reused FD
is not touched before the pre-handlers are called.
with and ok djm@
[sshconnect2.c channels.c sshconnect.c]
Set close-on-exec on various descriptors so they don't get leaked to
child processes. bz #1643, patch from jchadima at redhat, ok deraadt.
[ssh_config.5 sshd.c misc.h ssh-keyscan.1 readconf.h sshconnect.c
channels.c channels.h servconf.h servconf.c ssh.1 ssh-keyscan.c scp.1
sftp.1 sshd_config.5 readconf.c ssh.c misc.c]
Allow to set the rdomain in ssh/sftp/scp/sshd and ssh-keyscan.
ok markus@
set IPV6_V6ONLY for local forwarding with GatwayPorts=yes. Unify
setting IPV6_V6ONLY behind a new function misc.c:sock_set_v6only()
report and fix from jan.kratochvil AT redhat.com
the pty master on Solaris, since it never succeeds and can hang if large
amounts of data is sent to the slave (eg a copy-paste). Based on a patch
originally from Doke Scott, ok djm@
[canohost.c canohost.h channels.c channels.h clientloop.c readconf.c]
[readconf.h serverloop.c ssh.c]
support remote port forwarding with a zero listen port (-R0:...) to
dyamically allocate a listen port at runtime (this is actually
specified in rfc4254); bz#1003 ok markus@
[channels.c channels.h session.c]
make Channel->path an allocated string, saving a few bytes here and
there and fixing bz#1380 in the process; ok markus@
[channels.c]
call channel destroy callbacks on receipt of open failure messages.
fixes client hangs when connecting to a server that has MaxSessions=0
set spotted by imorgan AT nas.nasa.gov; ok markus@
[channels.c servconf.c]
channel_print_adm_permitted_opens() should deal with all the printing
for that config option. suggested by markus@; ok markus@ djm@
dtucker@
[packet.c scp.c serverloop.c sftp-client.c ssh-agent.c ssh-keyscan.c]
[sshd.c] Explicitly handle EWOULDBLOCK wherever we handle EAGAIN, on
some platforms (HP nonstop) it is a distinct errno;
bz#1467 reported by sconeu AT yahoo.com; ok dtucker@
[channels.c channels.h session.c]
don't call isatty() on a pty master, instead pass a flag down to
channel_set_fds() indicating that te fds refer to a tty. Fixes a
hang on exit on Solaris (bz#1463) in portable but is actually
a generic bug; ok dtucker deraadt markus
[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@