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Simon Tatham cbfba7a0e9 Greatly improve printf format-string checking.
I've added the gcc-style attribute("printf") to a lot of printf-shaped
functions in this code base that didn't have it. To make that easier,
I moved the wrapping macro into defs.h, and also enabled it if we
detect the __clang__ macro as well as __GNU__ (hence, it will be used
when building for Windows using clang-cl).

The result is that a great many format strings in the code are now
checked by the compiler, where they were previously not. This causes
build failures, which I'll fix in the next commit.
2020-01-26 16:35:04 +00:00
Simon Tatham 39248737a4 winnpc.c: add low-level connect_to_named_pipe() function.
This contains most of the guts of the previously monolithic function
new_named_pipe_client(), but it directly returns the HANDLE to the
opened pipe, or a string error message on failure.

new_named_pipe_client() is now a thin veneer on top of that, which
returns a Socket * by wrapping up the HANDLE into a HandleSocket or
the error message into an ErrorSocket as appropriate.

So it's now possible to connect to a named pipe, using all our usual
infrastructure (including in particular the ownership check of the
server, to defend against spoofing attacks), without having to have a
Socket-capable event loop in progress.
2020-01-04 13:52:22 +00:00
Simon Tatham 5d718ef64b Whitespace rationalisation of entire code base.
The number of people has been steadily increasing who read our source
code with an editor that thinks tab stops are 4 spaces apart, as
opposed to the traditional tty-derived 8 that the PuTTY code expects.

So I've been wondering for ages about just fixing it, and switching to
a spaces-only policy throughout the code. And I recently found out
about 'git blame -w', which should make this change not too disruptive
for the purposes of source-control archaeology; so perhaps now is the
time.

While I'm at it, I've also taken the opportunity to remove all the
trailing spaces from source lines (on the basis that git dislikes
them, and is the only thing that seems to have a strong opinion one
way or the other).
    
Apologies to anyone downstream of this code who has complicated patch
sets to rebase past this change. I don't intend it to be needed again.
2019-09-08 20:29:21 +01:00
Simon Tatham 7663e55526 Make proxy_for_destination() static.
It's never used outside proxy.c, so there's no need to expose its
declaration in proxy.h.
2019-07-28 15:42:30 +01:00
Simon Tatham 9545199ea5 Completely remove sk_flush().
I've only just noticed that it doesn't do anything at all!

Almost every implementation of the Socket vtable provides a flush()
method which does nothing, optionally with a comment explaining why
it's OK to do nothing. The sole exception is the wrapper Proxy_Socket,
which implements the method during its setup phase by setting a
pending_flush flag, so that when its sub-socket is later created, it
can call sk_flush on that. But since the sub-socket's sk_flush will do
nothing, even that is completely pointless!

Source control history says that sk_flush was introduced by Dave
Hinton in 2001 (commit 7b0e08270), who was going to use it for some
purpose involving the SSL Telnet support he was working on at the
time. That SSL support was never finished, and its vestigial
declarations in network.h were removed in 2015 (commit 42334b65b). So
sk_flush is just another vestige of that abandoned work, which I
should have removed in the latter commit but overlooked.
2019-07-28 10:40:47 +01:00
Simon Tatham 1bcf2a8397 Remove spurious 'return' in void method wrappers.
For some reason, only Visual Studio bothers to give a warning when you
write "return g()" inside a function f() when both f and g have void
return type.

(Of course it would be cleaner and more orthogonal if that was simply
legal C in the first place - but given that it's not, it would be nice
if more compilers let me know about it so I could fix it...)
2019-04-06 10:12:31 +01:00
Simon Tatham b9f20b84f3 log_proxy_stderr: limit the length of Event Log lines.
If a proxy command jabbers on standard error in a way that doesn't
involve any newline characters, we now won't keep buffering data for
ever.

(Not that I've heard of it happening, but I noticed the theoretical
possibility on the way past in a recent cleanup pass.)
2019-03-02 06:54:17 +00:00
Simon Tatham 1b4a08a953 Replace method-dispatch #defines with inline functions.
This replaces all the macros like ssh_key_sign() and win_draw_text()
which take an object containing a vtable pointer and do the
dereferencing to find the actual concrete method to call. Now they're
all inline functions, which means more sensible type-checking and more
comprehensible error reports when the types go wrong, and also means
that there's no risk of double-evaluating the object argument.
2019-02-27 19:48:14 +00:00
Simon Tatham 0cda34c6f8 Make lots of 'int' length fields into size_t.
This is a general cleanup which has been overdue for some time: lots
of length fields are now the machine word type rather than the (in
practice) fixed 'int'.
2019-02-06 21:46:10 +00:00
Simon Tatham 0aa8cf7b0d Add some missing 'const'.
plug_receive(), sftp_senddata() and handle_gotdata() in particular now
take const pointers. Also fixed 'char *receive_data' in struct
ProxySocket.
2019-02-06 21:46:10 +00:00
Simon Tatham 3214563d8e Convert a lot of 'int' variables to 'bool'.
My normal habit these days, in new code, is to treat int and bool as
_almost_ completely separate types. I'm still willing to use C's
implicit test for zero on an integer (e.g. 'if (!blob.len)' is fine,
no need to spell it out as blob.len != 0), but generally, if a
variable is going to be conceptually a boolean, I like to declare it
bool and assign to it using 'true' or 'false' rather than 0 or 1.

PuTTY is an exception, because it predates the C99 bool, and I've
stuck to its existing coding style even when adding new code to it.
But it's been annoying me more and more, so now that I've decided C99
bool is an acceptable thing to require from our toolchain in the first
place, here's a quite thorough trawl through the source doing
'boolification'. Many variables and function parameters are now typed
as bool rather than int; many assignments of 0 or 1 to those variables
are now spelled 'true' or 'false'.

I managed this thorough conversion with the help of a custom clang
plugin that I wrote to trawl the AST and apply heuristics to point out
where things might want changing. So I've even managed to do a decent
job on parts of the code I haven't looked at in years!

To make the plugin's work easier, I pushed platform front ends
generally in the direction of using standard 'bool' in preference to
platform-specific boolean types like Windows BOOL or GTK's gboolean;
I've left the platform booleans in places they _have_ to be for the
platform APIs to work right, but variables only used by my own code
have been converted wherever I found them.

In a few places there are int values that look very like booleans in
_most_ of the places they're used, but have a rarely-used third value,
or a distinction between different nonzero values that most users
don't care about. In these cases, I've _removed_ uses of 'true' and
'false' for the return values, to emphasise that there's something
more subtle going on than a simple boolean answer:
 - the 'multisel' field in dialog.h's list box structure, for which
   the GTK front end in particular recognises a difference between 1
   and 2 but nearly everything else treats as boolean
 - the 'urgent' parameter to plug_receive, where 1 vs 2 tells you
   something about the specific location of the urgent pointer, but
   most clients only care about 0 vs 'something nonzero'
 - the return value of wc_match, where -1 indicates a syntax error in
   the wildcard.
 - the return values from SSH-1 RSA-key loading functions, which use
   -1 for 'wrong passphrase' and 0 for all other failures (so any
   caller which already knows it's not loading an _encrypted private_
   key can treat them as boolean)
 - term->esc_query, and the 'query' parameter in toggle_mode in
   terminal.c, which _usually_ hold 0 for ESC[123h or 1 for ESC[?123h,
   but can also hold -1 for some other intervening character that we
   don't support.

In a few places there's an integer that I haven't turned into a bool
even though it really _can_ only take values 0 or 1 (and, as above,
tried to make the call sites consistent in not calling those values
true and false), on the grounds that I thought it would make it more
confusing to imply that the 0 value was in some sense 'negative' or
bad and the 1 positive or good:
 - the return value of plug_accepting uses the POSIXish convention of
   0=success and nonzero=error; I think if I made it bool then I'd
   also want to reverse its sense, and that's a job for a separate
   piece of work.
 - the 'screen' parameter to lineptr() in terminal.c, where 0 and 1
   represent the default and alternate screens. There's no obvious
   reason why one of those should be considered 'true' or 'positive'
   or 'success' - they're just indices - so I've left it as int.

ssh_scp_recv had particularly confusing semantics for its previous int
return value: its call sites used '<= 0' to check for error, but it
never actually returned a negative number, just 0 or 1. Now the
function and its call sites agree that it's a bool.

In a couple of places I've renamed variables called 'ret', because I
don't like that name any more - it's unclear whether it means the
return value (in preparation) for the _containing_ function or the
return value received from a subroutine call, and occasionally I've
accidentally used the same variable for both and introduced a bug. So
where one of those got in my way, I've renamed it to 'toret' or 'retd'
(the latter short for 'returned') in line with my usual modern
practice, but I haven't done a thorough job of finding all of them.

Finally, one amusing side effect of doing this is that I've had to
separate quite a few chained assignments. It used to be perfectly fine
to write 'a = b = c = TRUE' when a,b,c were int and TRUE was just a
the 'true' defined by stdbool.h, that idiom provokes a warning from
gcc: 'suggest parentheses around assignment used as truth value'!
2018-11-03 13:45:00 +00:00
Simon Tatham 82c83c1894 Improve sk_peer_info.
Previously, it returned a human-readable string suitable for log
files, which tried to say something useful about the remote end of a
socket. Now it returns a whole SocketPeerInfo structure, of which that
human-friendly log string is just one field, but also some of the same
information - remote IP address and port, in particular - is provided
in machine-readable form where it's available.
2018-10-21 10:02:10 +01:00
Simon Tatham b4c8fd9d86 New abstraction 'Seat', to pass to backends.
This is a new vtable-based abstraction which is passed to a backend in
place of Frontend, and it implements only the subset of the Frontend
functions needed by a backend. (Many other Frontend functions still
exist, notably the wide range of things called by terminal.c providing
platform-independent operations on the GUI terminal window.)

The purpose of making it a vtable is that this opens up the
possibility of creating a backend as an internal implementation detail
of some other activity, by providing just that one backend with a
custom Seat that implements the methods differently.

For example, this refactoring should make it feasible to directly
implement an SSH proxy type, aka the 'jump host' feature supported by
OpenSSH, aka 'open a secondary SSH session in MAINCHAN_DIRECT_TCP
mode, and then expose the main channel of that as the Socket for the
primary connection'. (Which of course you can already do by spawning
'plink -nc' as a separate proxy process, but this would permit it in
the _same_ process without anything getting confused.)

I've centralised a full set of stub methods in misc.c for the new
abstraction, which allows me to get rid of several annoying stubs in
the previous code. Also, while I'm here, I've moved a lot of
duplicated modalfatalbox() type functions from application main
program files into wincons.c / uxcons.c, which I think saves
duplication overall. (A minor visible effect is that the prefixes on
those console-based fatal error messages will now be more consistent
between applications.)
2018-10-11 19:58:42 +01:00
Simon Tatham ad0c502cef Refactor the LogContext type.
LogContext is now the owner of the logevent() function that back ends
and so forth are constantly calling. Previously, logevent was owned by
the Frontend, which would store the message into its list for the GUI
Event Log dialog (or print it to standard error, or whatever) and then
pass it _back_ to LogContext to write to the currently open log file.
Now it's the other way round: LogContext gets the message from the
back end first, writes it to its log file if it feels so inclined, and
communicates it back to the front end.

This means that lots of parts of the back end system no longer need to
have a pointer to a full-on Frontend; the only thing they needed it
for was logging, so now they just have a LogContext (which many of
them had to have anyway, e.g. for logging SSH packets or session
traffic).

LogContext itself also doesn't get a full Frontend pointer any more:
it now talks back to the front end via a little vtable of its own
called LogPolicy, which contains the method that passes Event Log
entries through, the old askappend() function that decides whether to
truncate a pre-existing log file, and an emergency function for
printing an especially prominent message if the log file can't be
created. One minor nice effect of this is that console and GUI apps
can implement that last function subtly differently, so that Unix
console apps can write it with a plain \n instead of the \r\n
(harmless but inelegant) that the old centralised implementation
generated.

One other consequence of this is that the LogContext has to be
provided to backend_init() so that it's available to backends from the
instant of creation, rather than being provided via a separate API
call a couple of function calls later, because backends have typically
started doing things that need logging (like making network
connections) before the call to backend_provide_logctx. Fortunately,
there's no case in the whole code base where we don't already have
logctx by the time we make a backend (so I don't actually remember why
I ever delayed providing one). So that shortens the backend API by one
function, which is always nice.

While I'm tidying up, I've also moved the printf-style logeventf() and
the handy logevent_and_free() into logging.c, instead of having copies
of them scattered around other places. This has also let me remove
some stub functions from a couple of outlying applications like
Pageant. Finally, I've removed the pointless "_tag" at the end of
LogContext's official struct name.
2018-10-10 21:50:50 +01:00
Simon Tatham cea1329b9e Make new_error_socket() into a printf-style function.
Almost all the call sites were doing a cumbersome dupprintf-use-free
cycle to get a formatted message into an ErrorSocket anyway, so it
seems more sensible to give them an easier way of doing so.

The few call sites that were passing a constant string literal
_shouldn't_ have been - they'll be all the better for adding a
strerror suffix to the message they were previously giving!
2018-10-07 15:14:11 +01:00
Simon Tatham ed652a70e8 Get rid of #ifdef DEFINE_PLUG_METHOD_MACROS.
I don't actually know why this was ever here; it appeared in the very
first commit that invented Plug in the first place (7b0e08270) without
explanation. Perhaps Dave's original idea was that sometimes you'd
need those macros _not_ to be defined so that the same names could be
reused as the methods for a particular Plug instance? But I don't
think that ever actually happened, and the code base builds just fine
with those macros defined unconditionally just like all the other sets
of method macros we now have, so let's get rid of this piece of cruft
that was apparently unnecessary all along.
2018-10-06 07:28:51 +01:00
Simon Tatham 884a7df94b Make Socket and Plug into structs.
I think that means that _every_ one of my traitoids is now a struct
containing a vtable pointer as one of its fields (albeit sometimes the
only field), and never just a bare pointer.
2018-10-06 07:28:51 +01:00
Simon Tatham b798230844 Name vtable structure types more consistently.
Now they're all called FooVtable, instead of a mixture of that and
Foo_vtable.
2018-10-06 07:28:51 +01:00
Simon Tatham 96ec2c2500 Get rid of lots of implicit pointer types.
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.
2018-10-04 19:10:23 +01:00
Simon Tatham 8dfb2a1186 Introduce a typedef for frontend handles.
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.
2018-09-19 22:10:58 +01:00
Simon Tatham b851d748be Merge duplicate implementations of the trivial Plug.
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.
2018-05-27 15:45:00 +01:00
Simon Tatham 5129c40bea Modernise the Socket/Plug vtable system.
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.
2018-05-27 15:28:54 +01:00
Simon Tatham 7babe66a83 Make lots of generic data parameters into 'void *'.
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.
2018-05-26 09:22:43 +01:00
Simon Tatham 12b38ad9e1 New header file 'defs.h'.
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.
2018-05-25 14:12:44 +01:00
Ben Harris 0d57b8a4d9 Make plug receive and closing functions return void instead of int.
Nothing was paying attention to their return values any more anyway.
2017-05-14 16:34:48 +01:00
Simon Tatham 0ac3526b3e Fix duplicate definition of typedef 'bufchain'.
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.
2016-04-06 10:08:52 +01:00
Simon Tatham 7c65b9c57a Option to log proxy setup diagnostics to the terminal.
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.
2015-11-22 15:12:10 +00:00
Simon Tatham 297efff303 In GUI PuTTY, log standard error from local proxy commands.
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).
2015-11-22 15:11:00 +00:00
Simon Tatham 3d4d4004e8 Log the setup of proxied network connections.
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.)
2015-11-22 15:11:00 +00:00
Simon Tatham a6e76ae453 Factor out the back ends' plug log functions.
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.
2015-11-22 15:11:00 +00:00
Simon Tatham 37cdfdcd51 Tell the truth about DNS lookups in the Event Log.
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.)
2015-11-22 15:10:59 +00:00
Simon Tatham 42334b65b0 Remove unused SSL declarations from network.h.
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.
2015-11-22 15:10:59 +00:00
Simon Tatham c8f83979a3 Log identifying information for the other end of connections.
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.
2015-05-18 14:03:10 +01:00
Simon Tatham 89da2ddf56 Giant const-correctness patch of doom!
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
2015-05-15 12:47:44 +01:00
Simon Tatham bb78583ad2 Implement connection sharing between instances of PuTTY.
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]
2013-11-17 14:05:41 +00:00
Simon Tatham 8be6fbaa09 Remove sk_{get,set}_private_ptr completely!
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]
2013-11-17 14:04:48 +00:00
Simon Tatham 19fba3fe55 Replace the hacky 'OSSocket' type with a closure.
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]
2013-11-17 14:03:55 +00:00
Simon Tatham a6139c1ad3 Add a Socket implementation which just holds an error message.
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]
2013-11-17 14:03:36 +00:00
Simon Tatham d35a41f6ba Revamp net_pending_errors using toplevel callbacks.
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]
2013-08-17 16:06:27 +00:00
Simon Tatham 808df44e54 Add an assortment of missing consts I've just noticed.
[originally from svn r9972]
2013-07-27 18:35:48 +00:00
Simon Tatham 58870f60e4 If you configure Unix PuTTY to use a proxy, tell it to even proxy
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]
2012-10-16 20:15:51 +00:00
Simon Tatham 947962e0b9 Revamp of EOF handling in all network connections, pipes and other
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]
2011-09-13 11:44:03 +00:00
Simon Tatham a1f3b7a358 Post-release destabilisation! Completely remove the struct type
'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]
2011-07-14 18:52:21 +00:00
Jacob Nevins d699530e4c Since r8305, Unix PuTTY has always "upgraded" an X11 display like "localhost:0"
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]
2009-02-24 01:01:23 +00:00
Simon Tatham 59691d28a3 Implement sk_addr_dup().
[originally from svn r8294]
2008-11-08 16:58:55 +00:00
Simon Tatham f70efc5cc6 Support for falling back through the list of addresses returned from
a DNS lookup, whether they're IPv4, v6 or a mixture of both.

[originally from svn r5119]
[this svn revision also touched putty-wishlist]
2005-01-16 14:29:34 +00:00
Simon Tatham 6daf6faede Integrate unfix.org's IPv6 patches up to level 10, with rather a lot
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]
2004-12-30 16:45:11 +00:00
Jacob Nevins 20f433efac Add a configuration option for TCP keepalives (SO_KEEPALIVE), default off.
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]
2004-06-20 17:07:38 +00:00
Jacob Nevins 92db92af5a Control of 'addr' is now handed over to {platform_,}new_connection() and
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]
2003-08-07 16:04:33 +00:00
Ben Harris 8a91a0516f Move prototype for platform_new_connection() to a header file so the
definitions can be checked against it.

[originally from svn r3248]
2003-06-06 10:42:14 +00:00