I've been using that signal since the very first commit of this source
file, as a combined way to be notified when the size of the drawing
area changes (typically due to user window resizing actions) and also
when the drawing area is first created and available to be drawn on.
Unfortunately, testing on Ubuntu 18.04, I ran into an oddity, in which
the call to gtk_widget_show(inst->window) in new_session_window() has
the side effect of delivering a spurious configure_event on the
drawing area with size 1x46 pixels. This causes the terminal to resize
itself to 1 column wide, and the mistake isn't rectified until a
followup configure-event arrives after new_session_window returns to
the GTK main loop. But that means terminal output can occur between
those two configure events (the connection-sharing "Reusing a shared
connection to host.name" is a good example), and when it does, it gets
embarrassingly wrapped at one character per line down the left column.
I briefly tried to bodge around this by trying to heuristically guess
which configure events were real and which were spurious, but I have
no faith in that strategy continuing to work. I think a better
approach is to abandon configure-event completely, and move to a
system in which the two purposes I was using it for are handled by two
_different_ GTK signals, namely "size-allocate" (for knowing when we
get resized) and "realize" (for knowing when the drawing area
physically exists for us to start setting up Cairo or GDK machinery).
The result seems to have fixed the silly one-column wrapping bug, and
retained the ability to handle window resizes, on every GTK version I
have conveniently available to test on, including GTK 3 both before
and after these spurious configures started to happen.
GTK 3 PuTTY/pterm has always assumed that if it was compiled with
_support_ for talking to the raw X11 layer underneath GTK and GDK,
then it was entitled to expect that raw X11 layer to exist at all
times, i.e. that GDK_DISPLAY_XDISPLAY would return a meaningful X
display that it could do useful things with. So if you ran it over the
GDK Wayland backend, it would immediately segfault.
Modern GTK applications need to cope with multiple GDK backends at run
time. It's fine for GTK PuTTY to _contain_ the code to find and use
underlying X11 primitives like the display and the X window id, but it
should be prepared to find that it's running on Wayland (or something
else again!) so those functions don't return anything useful - in
which case it should degrade gracefully to the subset of functionality
that can be accessed through backend-independent GTK calls.
Accordingly, I've centralised the use of GDK_DISPLAY_XDISPLAY into a
support function get_x_display() in gtkmisc.c, which starts by
checking that there actually is one first. All previous direct uses of
GDK_*_XDISPLAY now go via that function, and check the result for NULL
afterwards. (To save faffing about calling that function too many
times, I'm also caching the display pointer in more places, and
passing it as an extra argument to various subfunctions, mostly in
gtkfont.c.)
Similarly, the get_windowid() function that retrieves the window id to
put in the environment of pterm's child process has to be prepared for
there not to be a window id.
This isn't a complete fix for all Wayland-related problems. The other
one I'm currently aware of is that the default font is "server:fixed",
which is a bad default now that it won't be available on all backends.
And I expect that further problems will show up with more testing. But
it's a start.
This is a heavily edited (by me) version of a patch originally due to
Nico Williams and Viktor Dukhovni. Their comments:
* Don't delegate credentials when rekeying unless there's a new TGT
or the old service ticket is nearly expired.
* Check for the above conditions more frequently (every two minutes
by default) and rekey when we would delegate credentials.
* Do not rekey with very short service ticket lifetimes; some GSSAPI
libraries may lose the race to use an almost expired ticket. Adjust
the timing of rekey checks to try to avoid this possibility.
My further comments:
The most interesting thing about this patch to me is that the use of
GSS key exchange causes a switch over to a completely different model
of what host keys are for. This comes from RFC 4462 section 2.1: the
basic idea is that when your session is mostly bidirectionally
authenticated by the GSSAPI exchanges happening in initial kex and
every rekey, host keys become more or less vestigial, and their
remaining purpose is to allow a rekey to happen if the requirements of
the SSH protocol demand it at an awkward moment when the GSS
credentials are not currently available (e.g. timed out and haven't
been renewed yet). As such, there's no need for host keys to be
_permanent_ or to be a reliable identifier of a particular host, and
RFC 4462 allows for the possibility that they might be purely
transient and only for this kind of emergency fallback purpose.
Therefore, once PuTTY has done a GSS key exchange, it disconnects
itself completely from the permanent host key cache functions in
storage.h, and instead switches to a _transient_ host key cache stored
in memory with the lifetime of just that SSH session. That cache is
populated with keys received from the server as a side effect of GSS
kex (via the optional SSH2_MSG_KEXGSS_HOSTKEY message), and used if
later in the session we have to fall back to a non-GSS key exchange.
However, in practice servers we've tested against do not send a host
key in that way, so we also have a fallback method of populating the
transient cache by triggering an immediate non-GSS rekey straight
after userauth (reusing the code path we also use to turn on OpenSSH
delayed encryption without the race condition).
Colin Watson reports that on pre-releases of Ubuntu 18.04, configure
events which don't actually involve a change of window size show up
annoyingly often. Our handling of configure events involves throwing
away the backing Cairo surface, making a fresh blank one, and
scheduling a top-level callback to get terminal.c to do a repaint and
populate the new surface; so a draw event before that callback occurs
causes the window contents to flicker off and on again, not to mention
wasting a lot of time.
The simplest solution is to spot spurious configures, and respond by
not throwing away the previous Cairo surface in the first place.
Except in GTK1 (which doesn't have the former), via a gtkcompat.h
workaround.
Up-to-date GTK3 has deprecated gdk_beep(), causing build failures due
to the default -Werror setting.
Looks as if I haven't retried the GTK1 build for a while, and recent
GTK frontend development has broken it. The selection revamp has
pointed out that GTK1 didn't have the accessor function
gtk_selection_data_get_selection(), the standard GdkAtom value
GDK_SELECTION_CLIPBOARD, or keysyms for alphabetic characters; and
also I had an initialisation of one of my own structure fields
(dp->selparams) accidentally not guarded by the same GTK-versioning
ifdef that controls whether or not it was defined.
Ahem. I _spotted_ this in code review, and forgot to make the change
before pushing!
Because it's legitimate for a C implementation to define 'NULL' so
that it expands to just 0, it follows that if you use NULL in a
variadic argument list where the callee will expect to extract a
pointer, you run the risk of putting an int-sized rather than
pointer-sized argument on the list and causing the consumer to get out
of sync. So you have to add an explicit cast.
The PuTTY GUIs (Unix and Windows) maintain an in-memory event log
for display to users as they request. This uses ints for tracking
eventlog size, which is subject to memory exhaustion and (given
enough heap space) overflow attacks by servers (via, e.g., constant
rekeying).
Also a bounded log is more user-friendly. It is rare to want more
than the initial logging and the logging from a few recent rekey
events.
The Windows fix has been tested using Dr. Memory as a valgrind
substitute. No errors corresponding to the affected code showed up.
The Dr. Memory results.txt was split into a file per-error and then
grep Error $(grep -l windlg *)|cut -d: -f3-|sort |uniq -c
was used to compare. Differences arose from different usage of the GUI,
but no error could be traced to the code modified in this commit.
The Unix fix has been tested using valgrind. We don't destroy the
eventlog_stuff eventlog arrays, so we can't be entirely sure that we
don't leak more than we did before, but from code inspection it looks
like we don't (and anyways, if we leaked as much as before, just without
the integer overflow, well, that's still an improvement).
Now we don't annoyingly print the 'askappend' prompt if you ask a
PuTTY tool to write its packet log to something that's not a regular
file, such as /dev/fd/1 or /dev/tty or a named pipe.
(In the case of a named pipe, another annoyance fixed by this change
is that we also don't open it for reading in the course of the
existence test.)
Apparently I haven't tried a GTK2 build since the most recent set of
GTK-related code reorganisation. Some functions that were ifdef'ed out
in GTK3 builds were now unused even in GTK2 builds (and, because they
were also declared static, caused a -Werror build failure); and the
pointless stub version of gtkapp.c was missing a stub version of a
recently added function referred to from another module.
gtk_application_set_accels_for_action() is new in Gtk 3.12, but (e.g.)
Ubuntu 14.04 LTS still ships with Gtk 3.10.
On the other hand, the function I've used instead,
gtk_application_add_accelerator(), is deprecated from Gtk 3.14 onwards,
indicating that it will disappear in some future version, so I've left
the newer code in against that day.
It actually doesn't seem to be necessary: running 'otool -L' on the
real binary in the application bundle (Pterm-bin or PuTTY-bin) lists a
lot of paths starting with "@executable_path/../Resources/", which I
take to mean that the application is already set up to automatically
load the GTK shared libraries out of its own bundle directory, without
me having to give it the extra hint of DYLD_LIBRARY_PATH.
Moreover, I just got round to upgrading my Mac to High Sierra, and now
the version of osxlaunch _with_ DYLD_LIBRARY_PATH is causing a crash
at program load time, when the libpng in the MacOS system library
directory tries to use the libz in the application bundle and finds
that it doesn't provide an entry point it was expecting
('inflateValidate'). I could try to fix that by updating the libz
version in my OS X PuTTY build environment, but that seems to me to
set a precedent of running to keep up with any further dependencies
the system libraries happen to acquire in later releases. Better to
reset DYLD_LIBRARY_PATH so that the system libpng will load the system
libz and not get confused in the first place.
I've been having intermittent segfaults in this launcher program, and
by means of the new TEST_COMPILE_ON_LINUX facility introduced by
commit eef8cac28, I ran it under valgrind which helpfully pointed out
several pointers between linked-list nodes which I'd been relying on
OS memory allocation to happen to have zeroed for me.
By default, the program still builds on Linux to a stub that just
prints 'nothing to see here'. But if you compile with
-DTEST_COMPILE_ON_LINUX, it compiles to a program that still doesn't
do anything _actually_ useful, but goes through all the same motions
that real osxlaunch would go through, until the final execv(2) fails
because of course it's not _really_ living in an application bundle
directory of the right shape.
That allows me to run all the setup code under the debugging tools I'm
most used to, in my preferred environment. (Same rationale as having
puttyapp / ptermapp build for Linux too.)
I've filled in the results of some not-entirely-conclusive
investigation into the trackpad scrolling issue, some thoughts on
resizing, and reordered the items into what currently seems the most
sensible order to me.
This still isn't complete: I also need to add the variable collections
of things like mid-session special commands and saved session names,
and also I need to try to grey out menu items when they're not
applicable. But it's a start.
Just to avoid an endless proliferation of functions too small to see,
I've arranged an enumeration of action ids and a single
app_menu_action function on the receiving end, and in gtkapp.c, a list
macro that means I at least don't have to define the tiny callback
functions and the GActionEntry records by hand and keep them in sync.
This fixes the problem I'd previously noticed, that if you don't
configure the "Command key acts as Meta" setting, then keystrokes like
Command-Q which _ought_ to function as accelerators for the
application menu bar don't.
Turns out that this was for the totally obvious reason: the keyboard
event was still being processed by gtkwin.c's key_event() and
translated via the GTK IM into ordinary keyboard input. If instead I
return FALSE from key_event on detecting that a key event has a
non-Meta-configured Command modifier, then it will go to the next-
level key-event handler inside GTK itself which implements the menu
accelerator behaviour. Another problem ticked off the OS X checklist.
That's what I get for not testing on all platforms before I push.
Forgot that, since OS X GTK mimics X11 GTK closely enough to still use
the name "CLIPBOARD" for the unique system clipboard, I had left this
code base's internal name for it as CLIP_CLIPBOARD and not the
CLIP_SYSTEM I used on Windows.
The gtkapp.c menu now has a Copy as well as Paste option; those menu
items, as well as the corresponding ones on the context menu and Copy
All, now address sets of clipboards parametrised between OS X and
ordinary GTK in unix.h. Also I've tweaked the wording of the
context-menu items to not use the X-specific terminology "CLIPBOARD"
on OS X.
I had a segfault on OS X today at Pterm.app shutdown. I wasn't able to
reproduce it in a debugger, but the cause seemed to be that
clipboard_clear called term_deselect (this was from before the patch
series that renamed that function) when inst->term was already NULL.
This must be because a clipboard_data_instance outlived its associated
inst->term, and quite likely its associated inst as well. But we can't
free those structures when a gui_data is freed, because GTK callbacks
will still depend on them; so instead we must have each gui_data keep
a list of active cdis pointing at it, and then at destruction time,
walk along the list nulling out each one's pointer to part of itself.
I've done the general clipboard revamp, and also, since I added
Ctrl-Shift-{C,V} as a new pair of UI actions for copy and paste, I've
also fulfilled the requirement that there should be some method of
non-menu-based pasting that doesn't depend on a middle mouse button or
an Ins key.
I think the list of OS X missing features is now down to details of
the OS X GTK port _itself_, as opposed to structural issues in the
general code base.
On all platforms, you can now configure which clipboard the mouse
pastes from, which clipboard Ctrl-Ins and Shift-Ins access, and which
Ctrl-Shift-C and Ctrl-Shift-V access. In each case, the options are:
- nothing at all
- a clipboard which is implicitly written by the act of mouse
selection (the PRIMARY selection on X, CLIP_LOCAL everywhere else)
- the standard clipboard written by explicit copy/paste UI actions
(CLIPBOARD on X, the unique system clipboard elsewhere).
Also, you can control whether selecting text with the mouse _also_
writes to the explicitly accessed clipboard.
The wording of the various messages changes between platforms, but the
basic UI shape is the same everywhere.
All the data fields referring to the selection in 'struct gui_data'
have been pulled out into a separate structure of which there are now
multiple instances, and I've plumbed through what should be the right
pointers and integer ids to everywhere they should go. So now the GTK
front end defines CLIP_PRIMARY and CLIP_CLIPBOARD in place of the
temporary cop-out CLIP_SYSTEM from the previous commit, and copying
and pasting can be done via either one.
The defaults should be the same as before, except that now the non-Mac
versions of the GtkApplication front ends will access CLIP_PRIMARY in
response to most actions but the 'Paste' menu item will paste from
CLIP_CLIPBOARD. (That's mostly just as a demonstration that accessing
multiple clipboards even works.)
This lays some groundwork for making PuTTY's cut and paste handling
more flexible in the area of which clipboard(s) it reads and writes,
if more than one is available on the system.
I've introduced a system of list macros which define an enumeration of
integer clipboard ids, some defined centrally in putty.h (at present
just a CLIP_NULL which never has any text in it, because that seems
like the sort of thing that will come in useful for configuring a
given copy or paste UI action to be ignored) and some defined per
platform. All the front end functions that copy and paste take a
clipboard id, and the Terminal structure is now configured at startup
to tell it which clipboard id it should paste from on a mouse click,
and which it should copy from on a selection.
However, I haven't actually added _real_ support for multiple X11
clipboards, in that the Unix front end supports a single CLIP_SYSTEM
regardless of whether it's in OS X or GTK mode. So this is currently a
NFC refactoring which does nothing but prepare the way for real
changes to come.
Previously, both the Unix and Windows front ends would respond to a
paste action by retrieving data from the system clipboard, converting
it appropriately, _storing_ it in a persistent dynamic data block
inside the front end, and then calling term_do_paste(term), which in
turn would call back to the front end via get_clip() to retrieve the
current contents of that stored data block.
But, as far as I can tell, this was a completely pointless mechanism,
because after a data block was written into this storage area, it
would be immediately used for exactly one paste, and then never
accessed again until the next paste action caused it to be freed and
replaced with a new chunk of pasted data.
So why on earth was it stored persistently at all, and why that
callback mechanism from frontend to terminal back to frontend to
retrieve it for the actual paste action? I have no idea. This change
removes the entire system and replaces it with the completely obvious
alternative: the character-set-converted version of paste data is
allocated in a _local_ variable in the frontend paste functions,
passed directly to term_do_paste which now takes (buffer,length)
parameters, and freed immediately afterwards. get_clip() is gone.
When testing the previous commit, I went to great lengths to check all
the tricky corner cases of the detailed command-line argument handling
in Plink and PuTTY, on Windows and Unix. And did I also double-check
that I had not completely broken the very simplest possible invocation
of pterm? I did not.
The call to cmdline_host_ok() in gtkmain.c was failing an assertion in
pterm, because that function only expects to have been called by a
program that has the TOOLTYPE_HOST_ARG flag set - if that flag isn't
set, the program is expected to come up with its own answer to the
question (because I wasn't sure what the right fallback answer would
be). And I forgot to conditionalise the call between PuTTY and pterm.
This is another piece of long-overdue refactoring similar to the
recent commit e3796cb77. But where that one dealt with normalisation
of stuff already stored _in_ a Conf by whatever means (including, in
particular, handling a user typing 'username@host.name' into the
Hostname box of the GUI session dialog box), this one deals with
handling argv entries and putting them into the Conf.
This isn't exactly a pure no-functional-change-at-all refactoring. On
the other hand, it isn't a full-on cleanup that completely
rationalises all the user-visible behaviour as well as the code
structure. It's somewhere in between: I've preserved all the behaviour
quirks that I could imagine a reason for having intended, but taken
the opportunity to _not_ faithfully replicate anything I thought was
clearly just a bug.
So, for example, the following inconsistency is carefully preserved:
the command 'plink -load session nextword' treats 'nextword' as a host
name if the loaded session hasn't provided a hostname already, and
otherwise treats 'nextword' as the remote command to execute on the
already-specified remote host, but the same combination of arguments
to GUI PuTTY will _always_ treat 'nextword' as a hostname, overriding
a hostname (if any) in the saved session. That makes some sense to me
because of the different shapes of the overall command lines.
On the other hand, there are two behaviour changes I know of as a
result of this commit: a third argument to GUI PuTTY (after a hostname
and port) now provokes an error message instead of being silently
ignored, and in Plink, if you combine a -P option (specifying a port
number) with the historical comma-separated protocol selection prefix
on the hostname argument (which I'd completely forgotten even existed
until this piece of work), then the -P will now override the selected
protocol's default port number, whereas previously the default port
would win. For example, 'plink -P 12345 telnet,hostname' will now
connect via Telnet to port 12345 instead of to port 23.
There may be scope for removing or rethinking some of the command-
line syntax quirks in the wake of this change. If we do decide to do
anything like that, then hopefully having it all in one place will
make it easier to remove or change things consistently across the
tools.
Now 'putty user@host' will do what you wanted on Unix the same way it
always has on Windows.
(Thanks to Geoff Winkless for pointing out this inconsistency. I've
redone his actual patch my way, but he should still be credited for
the inspiration!)
A more or less identical piece of code to sanitise the CONF_host
string prior to session launch existed in Windows PuTTY and both
Windows and Unix Plink. It's long past time it was centralised.
While I'm here, I've added a couple of extra comments in the
centralised version, including one that - unfortunately - tries _but
fails_ to explain why a string of the form "host.name:1234" doesn't
get the suffix moved into CONF_port the way "user@host" moves the
prefix into CONF_username. Commit c1c1bc471 is the one I'm referring
to in the comment, and unfortunately it has an unexplained one-liner
log message from before I got into the habit of being usefully
verbose.
Stopping dialog boxes from being modal is now done; post_main() is
defunct; nothing left in gtkwin.c does an inappropriate whole-process
termination in response to a window-level error or closure condition.
(There is still modalfatalbox(), but that's not an _inappropriate_
process termination.)
This one's in frontend_keypress(), which is supposed to close the
window on the first keypress after the session inside it terminates
(that is, if your close-on-exit settings haven't made it close already
at that point).
It looks to me as if that behaviour doesn't currently _work_, and
hasn't worked for quite a while (certainly it was broken as of 0.70,
well before I started on this weekend's refactoring), because when the
session terminates we delete inst->ldisc and that's what would
otherwise be calling frontend_keypress. I should probably decide what
to do about that at some point. But for the moment, I'm satisfied to
simply not break this functionality any worse by making it not a
process-global exit :-)
For gtkapp-based tools that will have to stop being a program-fatal
error, so I've turned it into a function called window_setup_error
(which I could in principle reuse for other problems in the long and
tortuous progress of new_session_window), and kept the original
handling in gtkmain.c's implementation of that function while gtkapp.c
does something more sensible with a message box.
Not all gtkwin-based tools use it. Only the ones with one session per
process, which parse a command line describing that session and might
reasonably want to report errors in that command line by writing to
standard error and exiting the program.
In other words, precisely the ones that link in gtkmain.c and not
gtkapp.c. So gtkmain.c is a more sensible place to put that
error-reporting function.
This was one of a handful of remaining places in gtkwin.c where exit()
is called incautiously. Of course, a failure to set up one SSH
connection should only be fatal to that connection, not the whole
process, so really we should be feeding into the connection_fatal
system.
This existed in order to avoid the various confusions that could
happen if a toplevel callback ran in the context of a subsidiary
instance of gtk_main(). Now there aren't any subsidiary gtk_main
instances any more, this mechanism is no longer needed, and I can
throw it out. It was horrible anyway.
I think these began to appear as a consequencce of replacing
fatalbox() calls with more sensible error reports: the more specific a
direction I send a report in, the greater the annoying possibility of
re-entrance when the resulting error handler starts closing stuff.
This change requires me to break up the general cleanups in
delete_inst() into two halves: one runs when the error message box is
created, and cleans up the network connection and all the stuff
associated with it, and the other runs when the error message is
dismissed and the window can actually close.
It's an incoherent concept! There should not be any such thing as an
error box that terminates the entire program but is not modal. If it's
bad enough to terminate the whole program, i.e. _all_ currently live
connections, then there's no point in permitting progress to continue
in windows other than the affected one, because all windows are
affected anyway.
So all previous uses of fatalbox() have become modalfatalbox(), except
those which looked to me as if they shouldn't have been fatal in the
first place, e.g. lingering pieces of error handling in winnet.c which
ought to have had the severity of 'give up on this particular Socket
and close it' rather than 'give up on the ENTIRE UNIVERSE'.
