As with all D-Bus signal subscriptions, it’s possible for a signal
callback to be invoked in one thread (T1) while another thread (T2) is
unsubscribing from that signal. In this case, T1 is the main thread, and
T2 is the D-Bus connection worker thread which is unsubscribing all
signals as it’s in the process of closing.
Due to this possibility, all `user_data` for signal callbacks needs to
be referenced outside the lifecycle of the code which
subscribes/unsubscribes the signal. In other words, it’s not safe to
subscribe to a signal, store the subscription ID in a struct,
unsubscribe from the signal when freeing the struct, and dereference the
struct in the signal callback. The data passed to the signal callback
has to have its own strong reference.
Instead, it’s safe to subscribe to a signal and add a strong reference
to the struct, store the subscription ID in that struct, and unsubscribe
from the signal when the last external reference to your struct is
dropped. That unsubscription should break the refcount cycle between the
signal connection and the struct, and allow the struct to be completely
freed. Only with that approach is it safe to dereference the struct in
the signal callback, if there’s any possibility that the signal might be
unsubscribed from a separate thread.
The tests need specific additional main loop cycles to completely emit
the NameLost signal callback. Ideally they need refactoring, but this
will do (1000 test cycles passed).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #978
This just removes a now-redundant intermediate array. This means that
the `SignalSubscriber` instances are now potentially freed a little
sooner, inside the locked segment, but they are already careful to only
call their `user_data_free_func` in the right thread. So that should not
deadlock.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #978
Instead of storing a copy of the `callback` and `user_data` from a
`SignalSubscriber` in a `SignalInstance` struct (which is the closure
for signal callback data as it’s sent from the D-Bus worker thread to
the thread which originally subscribed to a signal), store a strong
reference to the `SignalSubscriber` struct itself.
This keeps the `SignalSubscriber` alive until the emission is
complete, which ensures that the `user_data` is not freed prematurely.
It also slightly reduces the allocation size of `SignalInstance` (not
that it matters).
This is threadsafe because the fields in `SignalSubscriber` are all
immutable after construction.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #978
Tie the destruction of the `user_data` to the destruction of the
`SignalSubscriber` struct. This is tidier, and ensures that the fields
in `SignalSubscriber` are all immutable after being set, so the
structure can safely be used across threads without locking.
It doesn’t matter which thread we call `call_destroy_notify()` in, since
it always defers calling `user_data_free_func` to the user-provided
`GMainContext`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #978
The `SignalSubscriber` structs contain the callback and `user_data` of each
subscriber to a signal, along with the `guint id` token held by that
subscriber to identify their subscription. There are one or more
`SignalSubscriber` structs for a given signal match rule, which is
represented as a `SignalData` struct.
Previously, the `SignalSubscriber` structs were stored in a `GArray` in
the `SignalData` struct, to reduce the number of allocations needed
when subscribing to a signal.
However, this means that a `SignalSubscriber` struct cannot have a
lifetime which exceeds the `SignalData` which contains it. In order to
fix the race in #978, one thread needs to be able to unsubscribe from a
signal (destroying the `SignalData` struct) while zero or more other
threads are in the process of calling the callbacks from a previous
emission of that signal (using the callback and `user_data` from zero or
more `SignalSubscriber` structs). Multiple threads could be calling
callbacks because callbacks are invoked in the `GMainContext` which
originally made a subscription, and GDBus supports subscribing to a
signal from multiple threads. In that case, the callbacks are dispatched
to multiple threads.
In order to allow the `SignalSubscriber` structs to outlive the
`SignalData` which contained their old match rule, store them in a
`GPtrArray` in the `SignalData` struct, and refcount them individually.
This commit in itself should make no functional changes to how GDBus
works, but will allow following commits to do so.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #978
This adds support for specifying multiple directories in the
GSETTINGS_SCHEMA_DIR environment variable by separating the values
using G_SEARCHPATH_SEPARATOR_S (colon on UNIX-like systems).
While programs could already register multiple custom GSettings schema
directories, it was not possible to achieve the same without writing
custom code, e.g. when using the gsettings command line tool.
Fixes#1998.
1) When parsing the executable name out of the command line,
see if the executable is rundll32.exe. If that is the case,
use the DLL name from its first argument as the "executable"
(this is used only for matching, and Windows Registry matches
these programs by their DLLs, so this is correct; for running
the application GLib would still use the command line, with
rundll32).
2) If an app runs with rundll32, ensure that rundll32 arguments
can be safely quoted. Otherwise GLib will break them with its
protective quotation.
Currently the code generated by gdbus-codegen uses
G_DBUS_CALL_FLAGS_NONE in its D-Bus calls, which occur for each method
defined by the input XML, and for proxy_set_property functions. This
means that if the daemon which implements the methods checks for
G_DBUS_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION and only does interactive
authorization if that flag is present, users of the generated code have
no way to cause the daemon to use interactive authorization (e.g. polkit
dialogs).
If we simply changed the generated code to always use
G_DBUS_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION, its users would have no
way to disallow interactive authorization (except for manually calling
the D-Bus method themselves).
So instead, this commit adds a GDBusCallFlags argument to method call
functions. Since this is an API break which will require changes in
projects using gdbus-codegen code, the change is conditional on the
command line argument --glib-min-version having the value 2.64 or
higher.
The impetus for this change is that I'm changing accountsservice to
properly respect G_DBUS_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION, and
libaccountsservice uses generated code for D-Bus method calls. So
these changes will allow libaccountsservice to continue allowing
interactive authorization, and avoid breaking any users of it which
expect that. See
https://gitlab.freedesktop.org/accountsservice/accountsservice/merge_requests/46
It might make sense to also let GDBusCallFlags be specified for property
set operations, but that is not needed in the case of accountsservice,
and would require significant work and breaking API in multiple places.
Similarly, the generated code currently hard codes -1 as the timeout
value when calling g_dbus_proxy_call*(). Add a timeout_msec argument so
the user of the generated code can specify the timeout as well.
Also, test this new API. In gio/tests/codegen.py we test that the new
arguments are generated if and only of --glib-min-version is used with a
value greater than or equal to 2.64, and in gio/tests/meson.build we
test that the generated code with the new API can be linked against.
The test_unix_fd_list() test also needed modification to continue
working now that we're using gdbus-test-codegen.c with code generated
with --glib-min-version=2.64 in one test.
Finally, update the docs for gdbus-codegen to explain the effect of
using --glib-min-version 2.64, both from this commit and from
"gdbus-codegen: Emit GUnixFDLists if an arg has type `h` w/
min-version".
Notification id (notify_id) is generated by notification daemon and
is valid only while daemon is running. If notification backend will
resend/reuse existing notification id (replace_id) after notification
daemon has been restarted it could replace wrong notification as same
id now can be used by different notification.
Previously, the documentation indicated that it was possible to call
g_tls_connection_handshake() after an initial handshake to trigger a
rehandshake, but only if TLS 1.2 or older is in use. However, there is
no documented way to ensure TLS 1.2 gets used. Nowadays, TLS 1.3 is used
by default.
I'm removing support for rehandshaking from glib-networking, as part of
a large refactoring where keeping rehandshakes would have entailed
significant additional complexity. So let's update the documentation to
indicate this is no longer ever supported. Applications should not
notice any difference.
Also, sync some previous handshake and rehandshake changes from
GTlsConnection to GDtlsConnection that were missed by mistake. I
try to remember to always update GDtlsConnection when touching
GTlsConnection documentation, but it's easy to forget.
We used XML to markup when we should have used our own brand of markdown
instead. This fixes the example being unreadable unless we trimmed the
XML away from it.
For the check "if (error != NULL)" to work as expected, the
create_server() (and create_server_full()) functions need to make
sure to return an error for all the possible failures, but this
might not always be the case.
Catch all the failures by testing for a non-NULL return value if there
was no error.
This shouldn't make any difference, because this code should only ever
be running in the main context that was thread-default at the time the
task was created, so it should already match the task's context. But
let's make sure, just in case.
They didn’t match the prototype generated by `gdbus-codegen`, which
meant that the FD list was being iterated incorrectly. Secondly, the
document ID list returned by the method was not NULL terminated, which
could lead to reading off the end of the list.
Somehow, neither of these bugs caused problems on Linux, but they did
cause problems on FreeBSD.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1983
Sadly, I forgot to update the documentation of
g_dtls_connection_handshake() last time I touched
g_tls_connection_handshake().
Let's also drop mention of STARTTLS, since that would use normal TLS,
not DTLS.
Reduce the number of iterations of things sent over a mock session bus
from different threads, to avoid the test spending quite so long
contested over the `gsignal.c` lock.
The test now takes about 10 seconds, according to `time`, rather than
around 100 or longer.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
By removing the cached global proxy in gdocumentportal.c, we can
re-enable the checks for proper shutdown of the session bus connection
in the dbus-appinfo.c test.
We can't use session_bus_down() in the test since gdocumentportal.c
holds a reference to the session bus connection, preventing it from
being finalised.
There are some GVfs locations (i.e. google-drive://, recent://), where
G_FILE_ATTRIBUTE_STANDARD_NAME is something tottaly different than
G_FILE_ATTRIBUTE_STANDARD_DISPLAY_NAME. Thus it would be nice to have
an easy way to show the display names. The only way currently to show
the display names is to use --attributes option, which is a bit
cumbersome. Let's add new --show-display-names option.
https://gitlab.gnome.org/GNOME/gvfs/issues/402
Those tests require Python, gobject-introspection and python-dbusmock
making them unsuitable to be run within the uninstalled test suite.
There are no restrictions of dependencies when it comes to installed
tests so use those to exercise GMemoryMonitor.
With debug enabled, g_dbus_connection_call_done() will throw a
g_warning() if the call failed (on purpose or not) while trying to the
serial of a non-existant reply.
(/builds/GNOME/glib/_build/gio/tests/gdbus-connection:26921): GLib-GIO-CRITICAL **: 10:10:16.311: g_dbus_message_get_reply_serial: assertion 'G_IS_DBUS_MESSAGE (message)' failed
This is a reimplementation of commit
4aba03562b from Will Thompson, but
conditional on the caller passing `--glib-min-version 2.64` to
`gdbus-codegen` to explicitly opt-in to the new behaviour.
From the commit message for that commit:
Previously, if a method was not annotated with org.gtk.GDBus.C.UnixFD
then the generated code would never contain GUnixFDList parameters, even
if the method has 'h' (file descriptor) parameters. However, in this
case, the generated code is essentially useless: the method cannot be
called or handled except in degenerate cases where the file descriptors
are missing or ignored.
Check the argument types for 'h', and if present, generate code as if
org.gtk.GDBus.C.UnixFD annotation were specified.
Includes a unit test too.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1726
This can be used by callers to opt-in to backwards-incompatible changes
to the behaviour or output of `gdbus-codegen` in future. This commit
doesn’t introduce any such changes, though.
Documentation and unit tests included.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1726
We got a complaint here that trashing via the
portal deletes the target of a symlink, not the
symlink itself. It turns out that following the
symlink already happens on the glib side.
https://github.com/flatpak/xdg-desktop-portal/issues/412
Skipped tests use "77" as the return value, so return 77 instead of 0
when the static-link.py test gets skipped because of a missing
environment variable.
If the fuse module is loaded but /dev/fuse doesn't exist, it's likely
that we're running in a rootless container, or a badly setup one, and we
won't be able to use fuse, so skip this test.
This happened on my local system using podman running as a normal user,
but this apparently works as expected in our CI[1].
[1]: https://gitlab.gnome.org/GNOME/glib/merge_requests/466
gtk-doc switched from DocBook to Markdown ages ago. There is no Markdown
equivalent for `<warning>`, so just drop it. It wasn’t adding anything
particularly valuable to the documentation.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1130
gtk-doc long since switched to Markdown, so we shouldn’t be emitting
DocBook `<link>` tags.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1130
Add a Python-based test wrapper for the `gdbus-codegen` executable,
similar to the existing tests for `glib-mkenums` and friends.
Add a few basic tests to begin with, but this doesn’t approach anywhere
near full coverage.
The next step is to move the existing Meson-based `gdbus-codegen` tests
from `gio/tests/meson.build` into the Python test suite.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1612
Previously, running `gdbus-codegen` with no arguments would exit
successfully with no output. While technically correct, that seems
unhelpful.
Require at least one interface file to be specified, so the user gets an
error message if they don’t specify any.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
It’s not particularly useful to put the gdbus-codegen version or the
name of the input file into the output from `gdbus-codegen`, and it
makes the output less reproducible. Drop it.
Also clarify the licensing.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1612
If not doing this it might happen that the cancelled signal is emitted
between reaching a reference count of 0 and finalizing the GSource, at
which point part of the GSource is already freed and calling any GSource
functions is dangerous.
Instead do this from the dispose function. At this time the GSource is
not partially freed yet and calling any GSource API is safe as long as
we ensure that we have a strong reference to the GSource before calling
any GSource API.
_kqsub_free assumes the caller has called _kqsub_cancel before calling
it. It checks if both 'deps' and 'fd' have been freed and aborts when
the condition is not met. Since the only caller of _kqsub_free is
g_kqueue_file_monitor_finalize, which does call _kqsub_cancel before
calling _kqsub_free, it seems to be correct for _kqsub_free to assert
values of these two members there.
However, it is possible for _kqsub_cancel to return early without
freeing any resource _kqsub_free expects to be freed. When the kevent
call fails, _kqsub_cancel does not free anything and _kqsub_free aborts
with assertion failure. This is an unexpected behavior, and it can be
fixed by always freeing resources in _kqsub_cancel.
Fixes: https://gitlab.gnome.org/GNOME/glib/issues/1935
"gio mount" doesn't print anything in case of success, however "gio mount -d"
prints "Mounted [id] at [mount_path]", which is inconsistent. It might probably
make sense for fstab volumes, but "gio mount -d" now support UUIDs which are
heavily used for daemon mounts and I think that it is not wise to print
"/run/user/$UID/gvfs" mount paths. The mount path can be still found over
"gio mount -l". Let's remove this message to make it more consistent.
"gio mount" only allows mounting volumes using device files, but not using
UUIDs. Volume monitors for various GVfs locations usually supports just UUIDs.
It would be handy to support them also for testing purposes (because
"g_file_mount_enclosing_volume()" does something else than "g_volume_mount()"
in case of shares provided by GOA volume monitor for example). Let's update
"-d" option to support also UUIDs.
https://gitlab.gnome.org/GNOME/gvfs/issues/251
It’s possible that one VFS operation will happen from a worker thread at
the same time as another is happening from the main thread, in which
case the static buffer which getpwnam() uses will be overwritten.
There’s a chance this will corrupt the results that one of the threads
receives.
Fix that by using the thread-safe getpwnam_r() version, via the new
g_unix_get_passwd_entry() function.
Fix the indentation of the surrounding block while we’re there.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1687
Those tests seem to regularly fail because a timeout (which we're
measuring outside the function that times out) is too long, which can
happen when the system is busy.
Don't run those tests unless "thorough" tests are requested. This
disables those tests by default.
Bail out! GLib-GIO:ERROR:../gio/tests/socket.c:1167:test_timed_wait: assertion failed (poll_duration < 112000): (114254 < 112000)
Bail out! GLib-GIO:ERROR:../gio/tests/cancellable.c:167:on_mock_operation_ready: assertion failed (error == (g-io-error-quark, 19)): error is NULL
Now we're returning the file type again, we need to mask it out to
compare with the mode. We can also check that the statbuf said the file
is a regular file.
Related: #1934
This reverts commit bfdc5fc4fc.
This changes the semantics of G_FILE_ATTRIBUTE_ID_UNIX_MODE, and we've
already found one user of the previous semantics (ostree).
Closes#1934
This function has numerous undocumented limitations. In particular, it
is not possible to ensure this function actually does anything. Document
these problems.
For many years after SSL 3.0 support was removed, we used this function
to indicate that we should perform protocol version fallback to the
lowest-supported protocol version, to workaround protocol version
intolerance. Nowadays this is no longer needed, and support has been
removed from glib-networking, so update the documentation.
GTlsConnection:rehandshake-mode has been deprecated since 2.60 using
the G_PARAM_DEPRECATED flag, but I forgot to add the right annotation to
the documentation. Oops.
The associated getter/setter functions were both deprecated properly.
This is the analogue of commit 7c4e6e9fbe, but applied to the
`GDBusMessage` parser, which does its own top-level parsing of the
variant format in D-Bus messages.
Previously, this code allowed arbitrary recursion of variant containers,
which could lead to a stack overflow. Now, that recursion is limited to
64 levels, as per the D-Bus specification:
https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-marshaling-signature
This includes a new unit test.
oss-fuzz#14870
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Tools like this should be configurable in a cross or native file. In
particular, if we are cross-compiling (with an executable wrapper like
qemu-arm), the build system ld is not necessarily able to manipulate
host system objects.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Otherwise we'll never test the EXTERNAL-only mode, because that relies
on testing the private macros
G_CREDENTIALS_UNIX_CREDENTIALS_MESSAGE_SUPPORTED and
G_CREDENTIALS_SOCKET_GET_CREDENTIALS_SUPPORTED.
Fixes: 9f962ebe "Add a test for GDBusServer authentication"
Signed-off-by: Simon McVittie <smcv@collabora.com>
This bypasses any issues we might have with containers where IPv6 is
returned by name resolution (particularly since GNOME/glib!616) but
doesn't necessarily actually work.
This comes at a minor test-coverage cost: we don't test GDBusServer's
default behaviour when told to listen on "tcp:" or "nonce-tcp:", and
on systems where IPv6 is available, we don't test it. If we want to
do those, we should perhaps do them in separate tests, and disable
those tests when binding to ::1 doesn't work.
Mitigates: GNOME/glib#1912
Signed-off-by: Simon McVittie <smcv@collabora.com>
Whitelist a safe set of characters for use in header guards instead of
maintaining a (growing) blacklist.
The whitelist is intentionally short since reading up on all
peculiarities of the C and C++ standard for identifiers is not my idea
of fun. :)
Fixes#1379
g_assert() is compiled out by `G_DISABLE_ASSERT` and doesn’t give such
useful messages on failure.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
No need to clear it to NULL before every time it’s used, since we assert
that it’s never set.
This introduces no functional changes.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
This avoids failure to listen on the given address on non-Linux Unix
kernels, where abstract sockets do not exist and so unix:tmpdir is
equivalent to unix:dir.
To avoid bugs like this one recurring, run most of these tests using
the unix:dir address type, where Linux is equivalent to other Unix
kernels; just do one unix:tmpdir test, to check that we still
interoperate with libdbus when using abstract sockets on Linux.
Resolves: GNOME/glib#1920
Fixes: 9f962ebe "Add a test for GDBusServer authentication"
Signed-off-by: Simon McVittie <smcv@collabora.com>
Previously, we used unix:tmpdir, except in tests that verify that a
particular address type works (notably unix:dir). Now we use unix:dir
most of the time, and unix:tmpdir gets its own test instead.
This helps to ensure that the tests continue to work on non-Linux Unix
kernels, where abstract sockets do not exist and so unix:tmpdir is
equivalent to unix:dir, even in the common case where the developer has
only tried the test on Linux.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Otherwise, since GNOME/glib!1193, the listening socket won't be deleted,
and if we are not using abstract sockets (for example on *BSD), g_rmdir
will fail with ENOTEMPTY.
Fixes: 8e32b8e8 "gdbusserver: Delete socket and nonce file when stopping server"
Resolves: GNOME/glib#1921
Signed-off-by: Simon McVittie <smcv@collabora.com>
The `on_run()` function could be executed in any worker thread from the
`GThreadedSocketListener`, but didn’t previously hold a strong reference
to the `GDBusServer`, which meant the server could be finalised in
another thread while `on_run()` was still running.
This was not ideal.
Hold a strong reference to the `GDBusServer` while the socket listener
is listening, i.e. between every paired call to `g_dbus_server_start()`
and `g_dbus_server_stop()`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1318
Rather than when finalising it. They should be automatically recreated
if the server is re-started.
This is important for ensuring that all externally visible behaviour of
the `GDBusServer` is synchronised with calls to
g_dbus_server_{start,stop}(). Finalisation of the server object could
happen an arbitrarily long time after g_dbus_server_stop() is called.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1318
So that the tests all end up using separate `.dbus-keyring` directories,
and hence not racing to create and acquire lock files, use
`G_TEST_OPTION_ISOLATE_DIRS` to ensure they all run in separate
disposable directories.
This has the added benefit of meaning they don’t touch the developer’s
actual `$HOME` directory.
This reduces the false-failure rate of `gdbus-peer` by a factor of 9 for
me on my local machine.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1912
There’s actually no need for them to be global or reused between unit
tests, so move them inside the test functions.
This is one step towards eliminating shared state between the unit
tests.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1912
If the directory is overridden, for example when running tests, the
parent directory of `.dbus-keyrings` (i.e. the fake `$HOME` directory)
might not exist. Create it automatically.
This should realistically not have an effect on non-test code.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1912
These can be hit in the tests (if multiple tests run in parallel are
racing for `~/.dbus-keyrings/org_gtk_gdbus_general.lock` for a prolonged
period) and will cause spurious test failures due to the use of
`G_DEBUG=fatal-warnings`.
Instead, allow the error messages to be inspected programmatically.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1912
In particular, if libbdus is available, we test interoperability with
a libdbus client: see GNOME/glib#1831. Because that issue describes a
race condition, we do each test repeatedly to try to hit the failing
case.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conceptually, a D-Bus server is really trying to determine the credentials
of (the process that initiated) a connection, not the credentials that
the process had when it sent a particular message. Ideally, it does
this with a getsockopt()-style API that queries the credentials of the
connection's initiator without requiring any particular cooperation from
that process, avoiding a class of possible failures.
The leading '\0' in the D-Bus protocol is primarily a workaround
for platforms where the message-based credentials-passing API is
strictly better than the getsockopt()-style API (for example, on
FreeBSD, SCM_CREDS includes a process ID but getpeereid() does not),
or where the getsockopt()-style API does not exist at all. As a result
libdbus, the reference implementation of D-Bus, does not implement
Linux SCM_CREDENTIALS at all - it has no reason to do so, because the
SO_PEERCRED socket option is equally informative.
This change makes GDBusServer on Linux more closely match the behaviour
of libdbus.
In particular, GNOME/glib#1831 indicates that when a libdbus client
connects to a GDBus server, recvmsg() sometimes yields a SCM_CREDENTIALS
message with cmsg_data={pid=0, uid=65534, gid=65534}. I think this is
most likely a race condition in the early steps to connect:
client server
connect
accept
send '\0' <- race -> set SO_PASSCRED = 1
receive '\0'
If the server wins the race:
client server
connect
accept
set SO_PASSCRED = 1
send '\0'
receive '\0'
then everything is fine. However, if the client wins the race:
client server
connect
accept
send '\0'
set SO_PASSCRED = 1
receive '\0'
then the kernel does not record credentials for the message containing
'\0' (because SO_PASSCRED was 0 at the time). However, by the time the
server receives the message, the kernel knows that credentials are
desired. I would have expected the kernel to omit the credentials header
in this case, but it seems that instead, it synthesizes a credentials
structure with a dummy process ID 0, a dummy uid derived from
/proc/sys/kernel/overflowuid and a dummy gid derived from
/proc/sys/kernel/overflowgid.
In an unconfigured GDBusServer, hitting this race condition results in
falling back to DBUS_COOKIE_SHA1 authentication, which in practice usually
succeeds in authenticating the peer's uid. However, we encourage AF_UNIX
servers on Unix platforms to allow only EXTERNAL authentication as a
security-hardening measure, because DBUS_COOKIE_SHA1 relies on a series
of assumptions including a cryptographically strong PRNG and a shared
home directory with no write access by others, which are not necessarily
true for all operating systems and users. EXTERNAL authentication will
fail if the server cannot determine the client's credentials.
In particular, this caused a regression when CVE-2019-14822 was fixed
in ibus, which appears to be resolved by this commit. Qt clients
(which use libdbus) intermittently fail to connect to an ibus server
(which uses GDBusServer), because ibus no longer allows DBUS_COOKIE_SHA1
authentication or non-matching uids.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Closes: https://gitlab.gnome.org/GNOME/glib/issues/1831
On Linux, if getsockopt SO_PEERCRED is used on a TCP socket, one
might expect it to fail with an appropriate error like ENOTSUP or
EPROTONOSUPPORT. However, it appears that in fact it succeeds, but
yields a credentials structure with pid 0, uid -1 and gid -1. These
are not real process, user and group IDs that can be allocated to a
real process (pid 0 needs to be reserved to give kill(0) its documented
special semantics, and similarly uid and gid -1 need to be reserved for
setresuid() and setresgid()) so it is not meaningful to signal them to
high-level API users.
An API user with Linux-specific knowledge can still inspect these fields
via g_credentials_get_native() if desired.
Similarly, if SO_PASSCRED is used to receive a SCM_CREDENTIALS message
on a receiving Unix socket, but the sending socket had not enabled
SO_PASSCRED at the time that the message was sent, it is possible
for it to succeed but yield a credentials structure with pid 0, uid
/proc/sys/kernel/overflowuid and gid /proc/sys/kernel/overflowgid. Even
if we were to read those pseudo-files, we cannot distinguish between
the overflow IDs and a real process that legitimately has the same IDs
(typically they are set to 'nobody' and 'nogroup', which can be used
by a real process), so we detect this situation by noticing that
pid == 0, and to save syscalls we do not read the overflow IDs from
/proc at all.
This results in a small API change: g_credentials_is_same_user() now
returns FALSE if we compare two credentials structures that are both
invalid. This seems like reasonable, conservative behaviour: if we cannot
prove that they are the same user, we should assume they are not.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Otherwise we’ll end up using the host’s `objcopy`, which will output
object files in the wrong format.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1916
This reverts commit 4aba03562b, preserving
the new tests but adjusting them to assert that the old behaviour is
restored.
As expected, there were a few projects which broke because of this.
Unfortunately, in one case the breakage crosses a project boundary:
sysprof ships D-Bus introspection XML, which is consumed by mutter and
passed through gdbus-codegen.
Since sysprof cannot add this annotation without breaking its existing
users, a warning is also not appropriate.
https://gitlab.gnome.org/GNOME/jhbuild/issues/41https://gitlab.gnome.org/GNOME/sysprof/issues/17https://gitlab.gnome.org/GNOME/glib/issues/1726
Previously we were keeping a pointer to the `GFileMonitor` in a
`GFileMonitorSource` instance, but since we weren’t keeping a strong
reference, that `GFileMonitor` instance could be finalised from another
thread at any point while the source was referring to it. Not good.
Use a weak reference, and upgrade it to a strong reference whenever the
`GFileMonitorSource` is referring to the file monitor.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1903
It’s not enough to unref the monitor, since the GLib worker thread might
still hold a reference to it.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1903
`DesktopFileDir` pointers are passed around between threads: they are
initially created on the main thread, but a pointer to them is passed to
the GLib worker thread in the file monitor callback
(`desktop_file_dir_changed()`).
Accordingly, the `DesktopFileDir` objects either have to be
(1) immutable;
(2) reference counted; or
(3) synchronised between the two threads
to avoid one of them being used by one thread after being freed on
another. Option (1) changed with commit 99bc33b6 and is no longer an
option. Option (3) would mean blocking the main thread on the worker
thread, which would be hard to achieve and is against the point of
having a worker thread. So that leaves option (2), which is implemented
here.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1903
When the _g_dbus_worker_flush_sync() schedules the 'data' and releases
the worker->write_lock, it is possible for the GDBus worker thread thread
to finish the D-Bus call and acquire the worker->write_lock before
the _g_dbus_worker_flush_sync() re-acquires it in the if (data != NULL) body.
When that happens, the ostream_flush_cb() increases the worker->write_num_messages_flushed
and then releases the worker->write_lock. The write lock is reacquired by
the _g_dbus_worker_flush_sync(), which sees that the while condition is satisfied,
thus it doesn't enter the loop body and immediately clears the data members and
frees the data structure itself. The ostream_flush_cb() is still ongoing, possibly
inside flush_data_list_complete(), where it accesses the FlushData, which can be
in any stage of being freed.
Instead, add an explicit boolean flag indicating when the flush is truly finished.
Closes#1896
`-1` isn’t a valid member of the enum, so cast to `int` first. This
fixes a compiler warning on Android.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Mounts are currently completed only if the prefix looks like scheme,
however, this doesn't work well if the mounts have also path component.
Let's always include them to fix this issue. The mounts are cached by the
volume monitors, so it should not significantly affect the performance.
Currently, "gio mount google-drive<tab>" isn't completed even though
that volume exists for google-drive://oholy@redhat.com/. Let's use
"gio mount -li" output to complete also activation roots of volumes.
Currently, "gio list file:///h<tab>" doesn't complete "file:///home"
because the result of "dirname file:///h" is not "file:///" but "file:/",
which breaks the consequent logic. Let's subtract basename from the
path in order to workaround this issue.
Fixes build failure:
../gio/gunixmounts.c: In function ‘_g_get_unix_mounts’:
../gio/gunixmounts.c:742:53: error: ‘struct mnttab’ has no member named ‘mnt_opts’; did you mean ‘mnt_mntopts’?
742 | mntent.mnt_opts,
| ^~~~~~~~
| mnt_mntopts
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
g_date_time_add_seconds() and g_date_time_add_full() use floating-point
seconds, which can result in the value varying slightly from what's
actually on disk. This causes intermittent test failures in
gio/tests/g-file-info.c on Debian i386, where we set a file's mtime
to be 50µs later, then read it back and sometimes find that it is only
49µs later than the previous value.
I've only seen this happen on i386, which means it might be to do with
different floating-point rounding when a value is stored in the 80-bit
legacy floating point registers rather than in double precision.
g_date_time_add() takes a GTimeSpan, which is in microseconds;
conveniently, that's exactly what we get from the GFileInfo.
Bug-Debian: https://bugs.debian.org/941547
Signed-off-by: Simon McVittie <smcv@collabora.com>
If we're cross-compiling, the installed-tests are useful even if we
can't run them on the build machine: we can copy them to the host
machine (possibly via a distro package like Debian's libglib2.0-tests)
and run them there.
While I'm changing the build-tests condition anyway, deduplicate it.
Based on a patch by Helmut Grohne.
Bug-Debian: https://bugs.debian.org/941509
Signed-off-by: Simon McVittie <smcv@collabora.com>
Skip it on systems which don’t support it, rather than compiling it out.
That gives us more information from test runs about which tests are
being run on which architectures.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
As with the previous commit, `st_mode` contains both the file type
(regular file, directory, symlink, special, etc.) and the file mode. For
`G_FILE_ATTRIBUTE_ID_UNIX_MODE`, we only want the file mode — so mask
`st_mode` with `~S_IFMT`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
chmod() technically only accepts file modes, not the file type and mode
as returned by stat(). Filter by `S_IFMT` to avoid sending the file
type (regular file, directory, symbolic link, etc.).
In practice, chmod() ignores anything except the file mode, but we might
as well comply with the specification.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
`GFile` always checks whether these vfuncs are `NULL` before calling
them, so document that it’s safe for implementations of `GFile` to not
implement them.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
The caller assumes that an unimplemented vfunc means that copying is
unsupported (and falls back to its internal copy implementation), so
there’s no point in implementing the vfunc just to unconditionally
return `G_IO_ERROR_NOT_SUPPORTED`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Rather than defining a vfunc which only ever returns
`G_IO_ERROR_NOT_SUPPORTED`, just don’t define the vfunc at all. The
caller in `GFile` interprets this as symlinks not being supported — so
we get the same behaviour, but without spending a vfunc call on it.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
The string is already translated in `GLocalFile`, so this doesn’t
introduce a new translatable string.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
This sets the `G_FILE_COPY_DEFAULT_PERMS` flag on the operation,
creating the copied file with default permissions rather than the same
permissions as the source file.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #174
If a copy operation is started with `G_FILE_COPY_TARGET_DEFAULT_PERMS`,
don’t create the destination file as private. Instead, create it with
the process’ current umask (i.e. ‘default permissions’).
This is a partial re-work of commit d8f8f4d637, with
input from Ondrej Holy.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #174
The actual parameter name in g_file_attribute_matcher_new()
attributes, so change the param reference to match. This way,
doc tools can create a proper link.
g_file_info_set_modification_time() and
g_file_info_set_modification_date_time() set the
G_FILE_ATTRIBUTE_TIME_MODIFIED_USEC attribute in addition to
G_FILE_ATTRIBUTE_TIME_MODIFIED, so microsecond precision is available
when provided by the caller, so mention both attributes in the docs.
Currently, there is no quick way to find whether and element is already
part of a list store, except for manually writing a for-loop and calling
`g_list_model_get_item()` and breaking when you find the item.
This is mostly just a small API addition to support this use case.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/1011
When compiling GLib with `-Wsign-conversion`, we get various warnings
about the atomic calls. A lot of these were fixed by
3ad375a629, but some remain. Fix them by
adding appropriate casts at the call sites.
Note that `g_atomic_int_{and,or,xor}()` actually all operate on `guint`s
rather than `gint`s (which is what the rest of the `g_atomic_int_*()`
functions operate on). I can’t find any written reasoning for this, but
assume that it’s because signedness is irrelevant when you’re using an
integer as a bit field. It’s unfortunate that they’re named a
`g_atomic_int_*()` rather than `g_atomic_uint_*()` functions.
Tested by compiling GLib as:
```
CFLAGS=-Wsign-conversion jhbuild make -ac |& grep atomic
```
I’m not going to add `-Wsign-conversion` to the set of default warnings
for building GLib, because it mostly produces false positives throughout
the rest of GLib.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1565
They provide more detailed failure messages, and aren’t compiled out
when building with `G_DISABLE_ASSERT`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
When future porting deprecated code to use
g_file_info_get_modification_date_time() we risk a number of breakages
because the current implementation also requires the additional use of
G_FILE_ATTRIBUTE_TIME_MODIFIED_USEC. This handles that situation gracefully
and returns a GDateTime with less precision.
Applications that want the additional precision, are already using the
additional attribute.
(Minor tweaks by Philip Withnall.)
This should make the code a bit easier to reason about, and squash some
static analysis warnings.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1767
The macros for the probes confuse the static analyser, and are often
called with arguments which the analyser things shouldn’t be used any
more (for example, the address of a block of memory which has just been
freed).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1767
These squash various warnings from `scan-build`. None of them are
legitimate bugs, but some of them do improve code readability a bit.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1767
Previously, if a method was not annotated with org.gtk.GDBus.C.UnixFD
then the generated code would never contain GUnixFDList parameters, even
if the method has 'h' (file descriptor) parameters. However, in this
case, the generated code is essentially useless: the method cannot be
called or handled except in degenerate cases where the file descriptors
are missing or ignored.
Check the argument types for 'h', and if present, generate code as if
org.gtk.GDBus.C.UnixFD annotation were specified.
This change will break any existing code which refers to the (useless)
wrappers for such methods. The workaround for such code is to add the
org.gtk.GDBus.C.UnixFD annotation, which will cause the same generated
code to be emitted before and after this change.
If this is found to cause widespread problems, we can explore a
different approach (perhaps emitting a warning from the code generator,
or annotating the symbols as deprecated).
https://gitlab.gnome.org/GNOME/glib/issues/1726
Instead of letting each directory to find its way to link with libdl,
it is easier to put the check in the top level, so its result can be
used by all directories.
It is a follow-up of https://gitlab.gnome.org/GNOME/glib/merge_requests/810.
The header file was installed when building using autotools, but was
inadvertently omitted in the meson targets.
Luckily, ABI is not impacted, since gnativesocketaddress.c was always
compiled and linked into libgio.
Fixes: #1854
The gobject introspection comments have a reference to an incorrect
class: they have, as 'self', the GSubprocess class instead of
GSubprocessLauncher.
This patch fixes this.
g_settings_backend_watch() uses a weak notify for keeping track of
the target. There's an explanation why this is supposed to be safe but
that explanation is wrong.
The following could happen before:
1. We have the target stored in the watch list
2. The last reference to the target is dropped in thread A and we end up
in g_settings_backend_watch_weak_notify() right before the mutex
3. g_settings_backend_dispatch_signal() is called from another thread B
and gets the mutex before 2.
4. g_weak_ref_init() is called on the target from thread B, which at
this point has a reference count of exactly one (see g_object_unref()
where it calls the weak notifies)
5. Thread A continues at 3. and drops the last reference and destroys
the object. Now the GWeakRef from 4. points to a destroyed object. Note
that GWeakRefs would be cleared before the weak notifies are called
6. At some later point another thread g_weak_ref_get() is called by
g_settings_backend_invoke_closure() and accesses an already destroyed
object with refcount 0 from the GWeakRef created in 4. by thread B (or
worse, already freed memory that was reused).
Solve this by actually storing a GWeakRef of the target in the watch
list and only access the target behind it via the GWeakRef API, and then
pass a strong reference to the notification dispatch code.
The weak notify is only used to remove the (potentially with empty
GWeakRef) target from the list of watches and the only place that
compares the target by pointer instead of going through the GWeakRef
API.
Fixes https://gitlab.gnome.org/GNOME/glib/issues/1870
If we fail to create a GWinhttpFile for a URI (for example, because it’s
an invalid URI or is badly encoded), don’t just return NULL. Instead,
fall back to the wrapped VFS which might be able to handle it instead.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1819
