All the main backend structures - Ssh, Telnet, Pty, Serial etc - now
describe structure types themselves rather than pointers to them. The
same goes for the codebase-wide trait types Socket and Plug, and the
supporting types SockAddr and Pinger.
All those things that were typedefed as pointers are older types; the
newer ones have the explicit * at the point of use, because that's
what I now seem to be preferring. But whichever one of those is
better, inconsistently using a mixture of the two styles is worse, so
let's make everything consistent.
A few types are still implicitly pointers, such as Bignum and some of
the GSSAPI types; generally this is either because they have to be
void *, or because they're typedefed differently on different
platforms and aren't always pointers at all. Can't be helped. But I've
got rid of the main ones, at least.
This is another major source of unexplained 'void *' parameters
throughout the code.
In particular, the currently unused testback.c actually gave the wrong
pointer type to its internal store of the frontend handle - it cast
the input void * to a Terminal *, from which it got implicitly cast
back again when calling from_backend, and nobody noticed. Now it uses
the right type internally as well as externally.
In the course of reworking the socket vtable system, I noticed that
both sshshare.c and x11fwd.c independently invented the idea of a Plug
none of whose methods do anything. We don't need more than one of
those, so let's centralise the idea to somewhere it can be easily
reused.
Now I've got FROMFIELD, I can rework it so that structures providing
an implementation of the Socket or Plug trait no longer have to have
the vtable pointer as the very first thing in the structure. In
particular, this means that the ProxySocket structure can now directly
implement _both_ the Socket and Plug traits, which is always
_logically_ how it's worked, but previously it had to be implemented
via two separate structs linked to each other.
This is a cleanup I started to notice a need for during the BinarySink
work. It removes a lot of faffing about casting things to char * or
unsigned char * so that some API will accept them, even though lots of
such APIs really take a plain 'block of raw binary data' argument and
don't care what C thinks the signedness of that data might be - they
may well reinterpret it back and forth internally.
So I've tried to arrange for all the function call APIs that ought to
have a void * (or const void *) to have one, and those that need to do
pointer arithmetic on the parameter internally can cast it back at the
top of the function. That saves endless ad-hoc casts at the call
sites.
This centralises a few things that multiple header files were
previously defining, and were protecting against each other's
redefinition with ifdefs - small things like structs and typedefs. Now
all those things are in a defs.h which is by definition safe to
include _first_ (out of all the codebase-local headers) and only need
to be defined once.
This was defined in misc.h, and also in network.h (because one
function prototype needed to refer to it in the latter), leading to a
build failure if any source file inconveniently included both those
headers.
Fixed by guarding each copy of the typedef with a #ifdef.
It has three settings: on, off, and 'only until session starts'. The
idea of the last one is that if you use something like 'ssh -v' as
your proxy command, you probably wanted to see the initial SSH
connection-setup messages while you were waiting to see if the
connection would be set up successfully at all, but probably _didn't_
want a slew of diagnostics from rekeys disrupting your terminal in
mid-emacs once the session had got properly under way.
Default is off, to avoid startling people used to the old behaviour. I
wonder if I should have set it more aggressively, though.
On both Unix and Windows, we now redirect the local proxy command's
standard error into a third pipe; data received from that pipe is
broken up at newlines and logged in the Event Log. So if the proxy
command emits any error messages in the course of failing to connect
to something, you now have a fighting chance of finding out what went
wrong.
This feature is disabled in command-line tools like PSFTP and Plink,
on the basis that in that situation it seems more likely that the user
would expect standard-error output to go to the ordinary standard
error in the ordinary way. Only GUI PuTTY catches it and logs it like
this, because it either doesn't have a standard error at all (on
Windows) or is likely to be pointing it at some completely unhelpful
session log file (under X).
I've defined a new value for the 'int type' parameter passed to
plug_log(), which proxy sockets will use to pass their backend
information on how the setup of their proxied connections are going.
I've implemented support for the new type code in all _nontrivial_
plug log functions (which, conveniently, are precisely the ones I just
refactored into backend_socket_log); the ones which just throw all
their log data away anyway will do that to the new code as well.
We use the new type code to log the DNS lookup and connection setup
for connecting to a networked proxy, and also to log the exact command
string sent down Telnet proxy connections (so the user can easily
debug mistakes in the configured format string) and the exact command
executed when spawning a local proxy process. (The latter was already
supported on Windows by a bodgy logging call taking advantage of
Windows in particular having no front end pointer; I've converted that
into a sensible use of the new plug_log facility, and done the same
thing on Unix.)
I'm about to want to make a change to all those functions at once, and
since they're almost identical, it seemed easiest to pull them out
into a common helper. The new source file be_misc.c is intended to
contain helper code common to all network back ends (crypto and
non-crypto, in particular), and initially it contains a
backend_socket_log() function which is the common part of ssh_log(),
telnet_log(), rlogin_log() etc.
We've always had the back-end code unconditionally print 'Looking up
host' before calling name_lookup. But name_lookup doesn't always do an
actual lookup - in cases where the connection will be proxied and
we're configured to let the proxy do the DNS for us, it just calls
sk_nonamelookup to return a dummy SockAddr with the unresolved name
still in it. It's better to print a message that varies depending on
whether we're _really_ doing DNS or not, e.g. so that people can tell
the difference between DNS failure and proxy misconfiguration.
Hence, those log messages are now generated inside name_lookup(),
which takes a couple of extra parameters for the purpose - a frontend
pointer to pass to logevent(), and a reason string so that it can say
what the hostname it's (optionally) looking up is going to be used
for. (The latter is intended for possible use in logging subsidiary
lookups for port forwarding, though the moment I haven't changed
the current setup where those connection setups aren't logged in
detail - we just pass NULL in that situation.)
There was a very old plan to flesh this out into an implementation of
SSLified Telnet, back when it looked as if that might be the winning
option for encrypted remote login. But SSH won, so that random junk in
network.h has been sitting around for decades doing nothing useful.
When anyone connects to a PuTTY tool's listening socket - whether it's
a user of a local->remote port forwarding, a connection-sharing
downstream or a client of Pageant - we'd like to log as much
information as we can find out about where the connection came from.
To that end, I've implemented a function sk_peer_info() in the socket
abstraction, which returns a freeform text string as best it can (or
NULL, if it can't get anything at all) describing the thing at the
other end of the connection. For TCP connections, this is done using
getpeername() to get an IP address and port in the obvious way; for
Unix-domain sockets, we attempt SO_PEERCRED (conditionalised on some
moderately hairy autoconfery) to get the pid and owner of the peer. I
haven't implemented anything for Windows named pipes, but I will if I
hear of anything useful.
Having found a lot of unfixed constness issues in recent development,
I thought perhaps it was time to get proactive, so I compiled the
whole codebase with -Wwrite-strings. That turned up a huge load of
const problems, which I've fixed in this commit: the Unix build now
goes cleanly through with -Wwrite-strings, and the Windows build is as
close as I could get it (there are some lingering issues due to
occasional Windows API functions like AcquireCredentialsHandle not
having the right constness).
Notable fallout beyond the purely mechanical changing of types:
- the stuff saved by cmdline_save_param() is now explicitly
dupstr()ed, and freed in cmdline_run_saved.
- I couldn't make both string arguments to cmdline_process_param()
const, because it intentionally writes to one of them in the case
where it's the argument to -pw (in the vain hope of being at least
slightly friendly to 'ps'), so elsewhere I had to temporarily
dupstr() something for the sake of passing it to that function
- I had to invent a silly parallel version of const_cmp() so I could
pass const string literals in to lookup functions.
- stripslashes() in pscp.c and psftp.c has the annoying strchr nature
The basic strategy is described at the top of the new source file
sshshare.c. In very brief: an 'upstream' PuTTY opens a Unix-domain
socket or Windows named pipe, and listens for connections from other
PuTTYs wanting to run sessions on the same server. The protocol spoken
down that socket/pipe is essentially the bare ssh-connection protocol,
using a trivial binary packet protocol with no encryption, and the
upstream has to do some fiddly transformations that I've been
referring to as 'channel-number NAT' to avoid resource clashes between
the sessions it's managing.
This is quite different from OpenSSH's approach of using the Unix-
domain socket as a means of passing file descriptors around; the main
reason for that is that fd-passing is Unix-specific but this system
has to work on Windows too. However, there are additional advantages,
such as making it easy for each downstream PuTTY to run its own
independent set of port and X11 forwardings (though the method for
making the latter work is quite painful).
Sharing is off by default, but configuration is intended to be very
easy in the normal case - just tick one box in the SSH config panel
and everything else happens automatically.
[originally from svn r10083]
It was only actually used in X11 and port forwarding, to find internal
state structures given only the Socket that ssh.c held. So now that
that lookup has been reworked to be the sensible way round,
private_ptr is no longer used for anything and can be removed.
[originally from svn r10075]
The mechanism for constructing a new connection-type Socket when a
listening one receives an incoming connection previously worked by
passing a platform-specific 'OSSocket' type to the plug_accepting
function, which would then call sk_register to wrap it with a proper
Socket instance. This is less flexible than ideal, because it presumes
that only one kind of OS object might ever need to be turned into a
Socket. So I've replaced OSSocket throughout the code base with a pair
of parameters consisting of a function pointer and a context such that
passing the latter to the former returns the appropriate Socket; this
will permit different classes of listening Socket to pass different
function pointers.
In deference to the reality that OSSockets tend to be small integers
or pointer-sized OS handles, I've made the context parameter an
int/pointer union that can hold either of those directly, rather than
the usual approach of making it a plain 'void *' and requiring a
context structure to be dynamically allocated every time.
[originally from svn r10068]
This isn't yet used, but I plan to use it in situations where you have
to report errors by returning a valid Socket on which the client wlil
call sk_socket_error, but in fact you notice the error _before_
instantiating your usual kind of Socket. The resulting Socket is
usable for nothing except reading out the error string and closing it.
[originally from svn r10065]
Again, I've removed the special-purpose ad-hockery from the assorted
front end message loops that dealt with deferred handling of socket
errors, and instead uxnet.c and winnet.c arrange that for themselves
by calling the new general top-level callback mechanism.
[originally from svn r10023]
localhost connections, and also enable X forwarding in such a way that
it will attempt to connect to a Unix-domain X server socket, an
assertion will fail when proxy_for_destination() tries to call
sk_getaddr(). Fix by ensuring that Unix-domain sockets are _never_
proxied, since they fundamentally can't be.
[originally from svn r9688]
data channels. Should comprehensively fix 'half-closed', in principle,
though it's a big and complicated change and so there's a good chance
I've made at least one mistake somewhere.
All connections should now be rigorous about propagating end-of-file
(or end-of-data-stream, or socket shutdown, or whatever) independently
in both directions, except in frontends with no mechanism for sending
explicit EOF (e.g. interactive terminal windows) or backends which are
basically always used for interactive sessions so it's unlikely that
an application would be depending on independent EOF (telnet, rlogin).
EOF should now never accidentally be sent while there's still buffered
data to go out before it. (May help fix 'portfwd-corrupt', and also I
noticed recently that the ssh main session channel can accidentally
have MSG_EOF sent before the output bufchain is clear, leading to
embarrassment when it subsequently does send the output).
[originally from svn r9279]
'Config' in putty.h, which stores all PuTTY's settings and includes an
arbitrary length limit on every single one of those settings which is
stored in string form. In place of it is 'Conf', an opaque data type
everywhere outside the new file conf.c, which stores a list of (key,
value) pairs in which every key contains an integer identifying a
configuration setting, and for some of those integers the key also
contains extra parts (so that, for instance, CONF_environmt is a
string-to-string mapping). Everywhere that a Config was previously
used, a Conf is now; everywhere there was a Config structure copy,
conf_copy() is called; every lookup, adjustment, load and save
operation on a Config has been rewritten; and there's a mechanism for
serialising a Conf into a binary blob and back for use with Duplicate
Session.
User-visible effects of this change _should_ be minimal, though I
don't doubt I've introduced one or two bugs here and there which will
eventually be found. The _intended_ visible effects of this change are
that all arbitrary limits on configuration strings and lists (e.g.
limit on number of port forwardings) should now disappear; that list
boxes in the configuration will now be displayed in a sorted order
rather than the arbitrary order in which they were added to the list
(since the underlying data structure is now a sorted tree234 rather
than an ad-hoc comma-separated string); and one more specific change,
which is that local and dynamic port forwardings on the same port
number are now mutually exclusive in the configuration (putting 'D' in
the key rather than the value was a mistake in the first place).
One other reorganisation as a result of this is that I've moved all
the dialog.c standard handlers (dlg_stdeditbox_handler and friends)
out into config.c, because I can't really justify calling them generic
any more. When they took a pointer to an arbitrary structure type and
the offset of a field within that structure, they were independent of
whether that structure was a Config or something completely different,
but now they really do expect to talk to a Conf, which can _only_ be
used for PuTTY configuration, so I've renamed them all things like
conf_editbox_handler and moved them out of the nominally independent
dialog-box management module into the PuTTY-specific config.c.
[originally from svn r9214]
to a Unix-domain socket. This typically works fine when PuTTY is run on the
same machine as the X server, but it's broken multi-hop X forwarding through
OpenSSH; when OpenSSH creates a proxy X server "localhost:10", it only listens
on TCP, not on a Unix-domain socket.
Instead, when deciding on the details of the display, we actively probe to see
if there's a Unix-domain socket we can use instead, and only use it if it's
there, falling back to the specified IP "localhost" if not.
Independently, when looking for local auth details in Xauthority for a
"localhost" TCP display, we prefer a matching Unix-domain entry, but will fall
back to an IP "localhost" entry (which would be unusual, but we don't trust a
Windows X server not to do it) -- this is a generalisation of the special case
added in r2538 (but removed in r8305, as the automatic upgrade masked the need
for it).
(This is now done in platform-independent code, so a side-effect is that
get_hostname() is now part of the networking abstraction on all platforms.)
[originally from svn r8462]
[r2538 == fda9983243]
[r8305 == ca6fc3a4da]
of polishing to bring them to what I think should in principle be
release quality. Unlike the unfix.org patches themselves, this
checkin enables IPv6 by default; if you want to leave it out, you
have to build with COMPAT=-DNO_IPV6.
I have tested that this compiles on Visual C 7 (so the nightlies
_should_ acquire IPv6 support without missing a beat), but since I
don't have IPv6 set up myself I haven't actually tested that it
_works_. It still seems to make correct IPv4 connections, but that's
all I've been able to verify for myself. Further testing is needed.
[originally from svn r5047]
[this svn revision also touched putty-wishlist]
No very good reason, but I've occasionally wanted to frob it to see if it
makes any difference to problems I'm having, and it was easy.
Tested that it does actually cause keepalives on Windows (with tcpdump);
should also work on Unix. Not implemented on Mac (does nothing), but then
neither is TCP_NODELAY.
Quite a big checkin, much of which is adding `keepalive' alongside `nodelay'
in network function calls.
[originally from svn r4309]
sk_new() on invocation; these functions become responsible for (eventually)
freeing it. The caller must not do anything with 'addr' after it's been passed
in. (Ick.)
Why:
A SOCKS5 crash appears to have been caused by overzealous freeing of
a SockAddr (ssh.c:1.257 [r2492]), which for proxied connections is
squirreled away long-term (and this can't easily be avoided).
It would have been nice to make a copy of the SockAddr, in case the caller has
a use for it, but one of the implementations (uxnet.c) hides a "struct
addrinfo" in there, and we have no defined way to duplicate those. (None of the
current callers _do_ have a further use for the SockAddr.)
As far as I can tell, everything _except_ proxying only needs addr for the
duration of the call, so sk_addr_free()s immediately. If I'm mistaken, it
should at least be easier to find the offending free()...
[originally from svn r3383]
[r2492 == bdd6633970]
ptrs and ints of different size and -Werror makes this serious).
The GTK bits are done by Colin's patch to use GINT_TO_POINTER
(thanks); the uxnet bits are done by cleaning up the rest of the
code. In particular, network.h now typedefs `OSSocket' to be a type
capable of holding whatever the OS's socket data type is that
underlies our socket abstraction. Individual platforms can make this
typedef themselves if they define OSSOCKET_DEFINED to prevent
network.h redoing it; so the Unix OSSocket is now int. Default is
still void *, so other platforms should be unaffected.
[originally from svn r3171]
proxy-indirection network functions (name_lookup, new_connection,
new_listener) takes a `const Config *' as an argument, and extracts
enough information from it before returning to handle that
particular network operation in accordance with the proxy settings
it specifies. This involved {win,ux}net.c due to a `const'
repercussion.
[originally from svn r2567]
Windows and Mac backends have acquired auth-finding functions which
do nothing; Unix backend has acquired one which actually works, so
Plink can now do X forwarding believably.
(This checkin stretches into some unlikely parts of the code because
there have been one or two knock-on effects involving `const'. Bah.)
[originally from svn r2536]
SockAddr, which just contains an unresolved hostname and is created
by a stub function in *net.c. It's an error to pass this to most of
the real-meat functions in *net.c; these fake addresses should have
been dealt with by the time they get down that far. proxy.c now
contains name_lookup(), a wrapper on sk_namelookup() which decides
whether or not to do real DNS, and the individual proxy
implementations each deal sensibly with being handed an unresolved
address and avoid ever passing one down to *net.c.
[originally from svn r2353]
well, though it's a lot less useful since you still can't bind to
low-numbered ports of odd loopback IPs. Should work in principle for
SSH2 remote forwardings as well as local ones, but OpenSSH seems
unwilling to cooperate.
[originally from svn r2344]
source files in which it's no longer required (it was previously
required in anything that included <putty.h>, but not any more).
Also moved a couple of stray bits of exposed WinSock back into
winnet.c (getservbyname from ssh.c and AF_INET from proxy.c).
[originally from svn r2160]
CONNECT, but contains an extensible framework to allow other
proxies. Apparently SOCKS and ad-hoc-telnet-proxy are already
planned (the GUI mentions them already even though they don't work
yet). GUI includes full configurability and allows definition of
exclusion zones. Rock and roll.
[originally from svn r1598]
Specifically, we explicitly closesocket() all open sockets, which
appears to be necessary since otherwise Windows sends RST rather
than FIN. I'm _sure_ that's a Windows bug, but there we go.
[originally from svn r1574]
done properly (by binding to INADDR_LOOPBACK) instead of hackishly
(by binding to INADDR_ANY, looking at the peer address when a
connection is accepted, and slamming the connection shut at that
point).
[originally from svn r1215]
by ceasing to listen on input channels if the corresponding output
channel isn't accepting data. Has had basic check-I-didn't-actually-
break-anything-too-badly testing, but hasn't been genuinely tested
in stress conditions (because concocting stress conditions is non-
trivial).
[originally from svn r1198]
Only currently works on SSH1; SSH2 should be doable but it's late
and I have other things to do tonight. The Cool Guy award for this
one goes to Nicolas Barry, for doing most of the work and actually
understanding the code he was adding to.
[originally from svn r1176]
Simon Tatham
Ben Harris
Jacob Nevins