Created attachment 129263 [details] [review]
On bus startup check given auth in config file against supported mechanisms.

With recent code starting dbus-daemon with an unsupported auth mechanism
let dbus-daemon silently ignore this issue. Clients connecting to this
server fails to connect without any descriptive explanation of the
root cause, only the message 'Rejected client connection due to lack
of memory' error is reported in dbus-daemon verbose log, which is disabled
in production environments.

With this patch dbus-daemon checks the supported auth mechanisms on startup
and shuts down with a descriptive error message, which gives admins an
immediate feedback on service startup/restart.

Signed-off-by: Ralf Habacker <ralf.habacker@freenet.de>

Bug:

Comment on attachment 129263 [details] [review]
On bus startup check given auth in config file against supported mechanisms.

Review of attachment 129263 [details] [review]:
-----------------------------------------------------------------

::: dbus/dbus-auth.c
@@ +2863,5 @@
> +  int i;
> +  _dbus_assert (buffer != NULL);
> +
> +  i = 0;
> +  while (all_mechanisms[i].mechanism != NULL)

You could turn this `while` loop into a `for` and compress the book-keeping code for `i` a bit.

::: dbus/dbus-auth.h
@@ +92,5 @@
>  
>  void          _dbus_auth_set_unix_fd_possible(DBusAuth               *auth, dbus_bool_t b);
>  dbus_bool_t   _dbus_auth_get_unix_fd_negotiated(DBusAuth             *auth);
> +DBUS_PRIVATE_EXPORT
> +dbus_bool_t   _dbus_auth_is_supported_mechanism(DBusString         *name);

Column alignment is a bit odd for the parameter here.

Comment on attachment 129263 [details] [review]
On bus startup check given auth in config file against supported mechanisms.

Review of attachment 129263 [details] [review]:
-----------------------------------------------------------------

What Philip said.

Created attachment 129279 [details] [review]
On bus startup check given auth in config file against supported mechanisms

- use for loop
- indention fix

Signed-off-by: Ralf Habacker <ralf.habacker@freenet.de>

Comment on attachment 129279 [details] [review]
On bus startup check given auth in config file against supported mechanisms

Review of attachment 129279 [details] [review]:
-----------------------------------------------------------------

LGTM with this nitpick.

::: dbus/dbus-auth.c
@@ +2859,5 @@
> + */
> +dbus_bool_t
> +_dbus_auth_dump_supported_mechanisms (DBusString *buffer)
> +{
> +  int i;

unsigned int.

commit pushed to git master

(In reply to Ralf Habacker from comment #6)
> commit pushed to git master
... with mentioned fix applied.

(Will be in 1.11.10)