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.
Detecting that the child process in a pterm has terminated is
important for _any_ kind of pterm, so it's a mistake to put the signal
handler setup _solely_ inside the optional pty_pre_init function which
does the privileged setup and forks off a utmp watchdog process. Now
the signal handler is installed even in the GtkApplication-based
multi-window front end to pterm, meaning it will exist even on OS X.
The big problem with making an OS X application out of a GTK program
is that it won't start unless DYLD_LIBRARY_PATH and several other
environment variables point at all the GTK machinery. So your app
bundle has to contain two programs: a launcher to set up that
environment, and then the real main program that the launcher execs
once it's done so.
But in our case, we also need pterm to start subprocesses _without_
all that stuff in the environment - so our launcher has to be more
complicated than the usual one, because it's also got to save every
detail of how the environment was when it started up. So this is the
launcher program I'm going to use. Comments in the header explain in
more detail how it'll work.
Also in this commit, I add the other end of the same machinery to
gtkapp.c and uxpty.c: the former catches an extra command-line
argument that the launcher used to indicate how it had munged the
environment, and stores it in a global variable where the latter can
pick it up after fork() and use to actually undo the munging.
This lays further groundwork for the OS X GTK3 port, which is going to
have to deal with multiple sessions sharing the same process. gtkwin.c
was a bit too monolithic for this, since it included some
process-global runtime state (timers, toplevel callbacks), some
process startup stuff (gtk_init, gtk_main, argv processing) and some
per-session-window stuff.
The per-session stuff remains in gtkwin.c, with the top-level function
now being new_session_window() taking a Conf. The new gtkmain.c
contains the outer skeleton of pt_main(), handling argv processing and
one-off startup stuff like setlocale; and the new gtkcomm.c contains
the pieces of PuTTY infrastructure like timers and uxsel that are
shared between multiple sessions rather than reinstantiated per
session, which have been rewritten to use global variables rather than
fields in 'inst' (since it's now clear to me that they'll have to
apply to all the insts in existence at once).
There are still some lurking assumptions of one-session-per-process,
e.g. the use of gtk_main_quit when a session finishes, and the fact
that the config box insists on running as a separate invocation of
gtk_main so that one session's preliminary config box can't coexist
with another session already active. But this should make it possible
to at least write an OS X app good enough to start testing with, even
if it doesn't get everything quite right yet.
This change is almost entirely rearranging existing code, so it
shouldn't be seriously destabilising. But two noticeable actual
changes have happened, both pleasantly simplifying:
Firstly, the global-variables rewrite of gtkcomm.c has allowed the
post_main edifice to become a great deal simpler. Most of its
complexity was about remembering what 'inst' it had to call back to,
and in fact the right answer is that it shouldn't be calling back to
one at all. So now the post_main() called by gtkdlg.c has become the
same function as the old inst_post_main() that actually did the work,
instead of the two having to be connected by a piece of ugly plumbing.
Secondly, a piece of code that's vanished completely in this
refactoring is the temporary blocking of SIGCHLD around most of the
session setup code. This turns out to have been introduced in 2002,
_before_ I switched to using the intra-process signal pipe strategy
for SIGCHLD handling in 2003. So I now expect that we should be robust
in any case against receiving SIGCHLD at an inconvenient moment, and
hence there's no need to block it.
A Plink invocation of the form 'plink -shareexists <session>' tests
for a currently live connection-sharing upstream for the session in
question. <session> can be any syntax you'd use with Plink to make the
actual connection (a host/port number, a bare saved session name,
-load, whatever).
I envisage this being useful for things like adaptive proxying - e.g.
if you want to connect to host A which you can't route to directly,
and you might already have a connection to either of hosts B or C
which are viable proxies, then you could write a proxy shell script
which checks whether you already have an upstream for B or C and goes
via whichever one is currently active.
Testing for the upstream's existence has to be done by actually
connecting to its socket, because on Unix the mere existence of a
Unix-domain socket file doesn't guarantee that there's a process
listening to it. So we make a test connection, and then immediately
disconnect; hence, that shows up in the upstream's event log.
On OS X, apparently, we can't do termios setup on the pty master, so
instead we have to leave it until we've opened the slave fd in the
child process. That works on Linux too, so let's leave it here rather
than having another cumbersome ifdef.
In a UTF-8 pterm, it makes sense to set the IUTF8 flag (on systems
that have one) on the pty device, so that line editing will take
account of UTF-8 multibyte characters.
The Pty that we created in pty_pre_init had its bufchain properly
initialised, but if that one didn't get created, then the one we
create in pty_init did not. Now both should go through the same init
routine.
OS X for some reason doesn't let my usual fcntl approach (wrapped in
nonblock()) work on pty masters - the fcntl(F_SETFL) fails, with the
(in this context) hilariously inappropriate error code ENOTTY. Work
around it by instead passing O_NONBLOCK to posix_openpt.
OS X dislikes us calling the setuid or setgid syscalls when not
privileged, even if we try to set ourselves to the _same_ uid/gid.
Since I don't anticipate this code needing to run setuid on OS X, and
since I do anticipate wanting to handle multiple ptys in a single
process so that pty_pre_init would be useless anyway, the simplest fix
seems to me to be just conditioning out the whole of pty_pre_init
completely.
If you open a pterm on a different display via the --display
command-line option rather than by setting $DISPLAY, I think (and
other terminals seem to agree) that it's sensible to set $DISPLAY
anyway for processes running inside the terminal.
The new way is gdk_display_get_name(gdk_display_get_default()), which
returns a const char * rather than a char *, so I've also had to
fiddle with the prototype and call sites of get_x_display().
(Also included gtkcompat.h into uxputty.c, since that wanted to call
gdk_get_display() but didn't previously include it.)
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
I've enabled gcc's format-string checking on dupprintf, by declaring
it in misc.h to have the appropriate GNU-specific attribute. This
pointed out a selection of warnings, which I've fixed.
[originally from svn r10084]
privileges just before dying of a fatal signal. I'm not sure what I
intended it for in the first place; it certainly isn't doing its job
properly (no setgid), it's causing compiler warnings due to not
checking the setuid return code, and we can't think of any useful
purpose for it.
[originally from svn r9766]
pty_utmp_helper_pipe _and_ the close of it if we're not going to write
should be conditionalised on the pipe existing, rather than just the
former!
[originally from svn r9729]
open("/dev/ptmx"), where the former is available. Improves
portability, since at least one OS (OpenBSD) supports the POSIX pty
functions but does it via an underlying mechanism which doesn't
involving having a /dev/ptmx.
[originally from svn r9728]
OS doesn't automatically assume it.
(It would seem faintly weird to me - surely opening the master end of
a given pty is a fairly good indication that you're _not_ a process
running inside it which wants to have it available as /dev/tty! But
you never know...)
[originally from svn r9727]
and the argument list contains only one string, try again by passing
that single string to "$SHELL -c" to be parsed as a shell command.
This matches xterm's behaviour (as of xterm 261, at least), and means
in practice that users can do _either_ of 'pterm -e some command' and
'pterm -e "some command"'.
(A quick survey suggests that the majority of X terminal programs agree
with pterm's old behaviour of only supporting '-e some command',
except that gnome-terminal only supports the other behaviour and xterm
supports both. With that disagreement, I think supporting both is
probably the sensible thing.)
[originally from svn r9575]
because (a) under that circumstance we won't be writing to utmp
anyway, and (b) if we aren't setuid, then we won't have created the
pty at the point we fork, so even if our subprocess _could_ have
written to utmp it wouldn't have done it right!
Spotted by valgrind (triggering on the access beyond the end of the
ttyname string in setup_utmp, clueing me in to it having been empty).
[originally from svn r9309]
'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]
SIGPIPE ignored in its child processes, leading to unexpected
behaviour inside pterms. (The gnome-session I'm sitting in front of
doesn't seem to do this as far as I can tell, but I don't doubt there
are some that do.) Add SIGPIPE to the list of signals we reset to
default behaviour before launching pterm's child process.
[originally from svn r9117]
except that O_NONBLOCK is standardised and FIONBIO isn't. In consequence,
replace our only use of FIONBIO with O_NONBLOCK.
Inspired by Jonathan H N Chin, who had problems with this on Solaris.
[originally from svn r7753]
port number in the GUI when the connection type is changed if the current
port number is the standard one for the current protocol.
It's not perfect, but it should make the common case of tabbing through the
Session panel easier when starting non-SSH connections on odd ports.
[originally from svn r7635]
Should be no significant change in behaviour.
(Well, entering usernames containing commas on Plink's command line will be
a little harder now.)
[originally from svn r7628]
subprocess. They were intended to make sure the child process didn't
inherit anything embarrassing or inconvenient from us, such as the
master end of its own pty, but now we instead do this by making sure
to set all our own fds to not-FD_CLOEXEC on creation. This should
fix Debian bug #357520.
(This doesn't seem to work _quite_ right in uxproxy.c's invocation
of a local proxy command: both ends of a GTK internal pipe end up in
the child process's fd space. This appears to be another GTK 1 bug,
inasmuch as it goes away when I build with Colin's preliminary GTK 2
patch; for the moment I think leaving that pipe lying around is
probably less harmful than hampering the proxy process's ability to
use extra fds by prior arrangement with PuTTY's parent process.)
[originally from svn r7107]
PuTTY causes the child process to inherit a lot of socket fds from
its parent, which is a pain if one of them then ends up holding open
a listening socket which the parent was using for port forwarding
after the parent itself is dead.
Therefore, this checkin sprinkles FD_CLOEXEC throughout the Unix
platform directory wherever there looks like being a long-lived fd.
[originally from svn r6917]
it's NULL. Since we already have one back end (uxpty) which doesn't
in fact talk to a network socket, and may well have more soon, I'm
replacing this TCP/IP-centric function with a nice neutral
`connected' function returning a boolean. Nothing else about its
semantics has currently changed.
[originally from svn r6810]
sufficiently large string into pterm in any circumstances in which
it's echoed back to the terminal will cause a deadlock once the
pty's write buffer fills up.
[originally from svn r6582]
X/Open and actually seems to be more common (NetBSD has it). Also use
updwtmpx() rather than directly writing to the wtmpx file, though more for
reasons of aesthetics than anything practical.
[originally from svn r5678]
_XOPEN_SOURCE. We do still need _GNU_SOURCE in order to get grantpt()
on GNU systems. This allows uxpty.c to compile on NetBSD.
[originally from svn r5675]
structure, in preparation for wanting more than one of them in a
single process. This can't be done cleanly, because the whole
business with pty_pre_init pre-allocating the pty rather assumes we
want a known number of the things before we drop privileges; so
there's a horrid hack to make pty_pre_init work on platforms that
have at most one pty instance per process, but at the same time
things ought to work sensibly with more than one per process _if_
pty_pre_init isn't required.
[originally from svn r5261]
Simon Tatham
Ben Harris
Jacob Nevins
Owen Dunn