sbus: add sbus_request_reply_error() This simplifies error handling in sbus requests since we avoid creating DBusError and checking for NULL manually. It removes few lines of code. This patch does not replace all calls to sbus_request_fail_and_finish since sometimes it is desirable to create the error manualy. But it replaces it in most recent places. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com> Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

SBUS: Print debug message when handler fails Reviewed-by: Sumit Bose <sbose@redhat.com> Reviewed-by: Jakub Hrozek <jhrozek@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

UTIL: Add ERR_SBUS_REQUEST_HANDLED In most cases when sbus request parsing finishes, the request is handled internally and a reply is sent to the caller. However, in handlers that are parsed and handled completely manually, we might want to be notified about this case so that the called of sbus_request_parse_or_finish() aborts the request and doesn't proceed with using the sbus request which is already freed internally in sbus_request_parse_or_finish(). Reviewed-by: Pavel Březina <pbrezina@redhat.com>

DEBUG: Add missing new lines Reviewed-by: Petr Cech <pcech@redhat.com>

sbus: Check string arguments for valid UTF-8 strings libdbus abort()s when a string argument is not valid UTF-8. Since the arguments sometimes come from untrusted sources, it's better to check the string validity explicitly. Reviewed-by: Sumit Bose <sbose@redhat.com>

sbus: Add a special error code for messages sent by the bus itself Reviewed-by: Pavel Březina <pbrezina@redhat.com>

sbus: Initialize errno if constructing message fails and add debug messages Reviewed-by: Pavel Březina <pbrezina@redhat.com>

sbus: remove unused 'reply as' functions These functions became unused after previous patch. Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

sbus: add object path to sbus request Object path is heavily used in implementation of methods from interfaces that are supported on whole subtrees. Although it can be obtained from a D-Bus message, it is nice to have it accessible directly. Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

SBUS: Initialize DBusError before using it In case either handler_fn() or invoker_fn() failed in sbus_request_invoke_or_finish() we would have accessed an uninitialized DBusError variable, causing a segfault. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

SBUS: Fix error handling after closing container If function dbus_message_iter_close_container fail the return variable ret will be set to EINVAL, but function will not be immediately terminated. "goto done" was missing. Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

sbus_request: fix potential NULL dereference Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

SBUS: Utility function sbus_request_return_array_as_variant Adds a utility function that returns an array of types values, each of a given size, with a given type in a variant. This utility function will be used by the GetAll property call. Reviewed-by: Stef Walter <stefw@redhat.com> Reviewed-by: Pavel Březina <pbrezina@redhat.com>

SBUS: Utility function sbus_request_return_as_variant Adds a utility function that returns a single value with a given type in a variant. This utility function will be used by the Get property call. Reviewed-by: Stef Walter <stefw@redhat.com> Reviewed-by: Pavel Březina <pbrezina@redhat.com>

SBUS: Add an async request to retrieve the caller ID Adds an async request sbus_get_sender_id_{send,recv} that allows retrieval of UID based on "sender" as returned by dbus_message_get_sender(). The UID is an int64_t to be able to use "-1" to as a fallback value for uknown or error cases. The unit test is added as a standalone one, not part of the sbus_tests because the request, and by extension the unit test relies on being connected to the system bus, which is very unlikely to work in a build system. Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Stef Walter <stefw@redhat.com>

SBUS: Add a convenience function sbus_error_new Adds a convenience function that constructs a DBusError on top of a talloc context and as such can be used to mark an sbus request as failed without having to create a DBusError instance by the caller. Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Stef Walter <stefw@redhat.com>

SBUS: Fix error handling condition Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Stef Walter <stefw@redhat.com>

SBUS: several trivial style fixes In SSSD we tend to use {} brackets around single-line blocks, too to make sure we don't forget to add them should the block become larger. We also don't add a space between function name and the opening "(". Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Stef Walter <stefw@redhat.com>

sbus request: fix error initialization fixes: sssd_dbus_request.c:28:1: error: missing initializer [-Werror=missing-field-initializers] sssd_dbus_request.c:28:1: error: (near initialization for 'error_internal.dummy1') [-Werror=missing-field-initializers]

sbus: Add type-safe DBus method handlers and finish functions Type safe method handlers allow methods not to have to do tedious unwrapping and wrapping of DBus method call messages or replies. Arguments of the following DBus types are supported in type-safe method handlers. In addition arrays of these are supported. y: uint8_t b: bool (but no arrays, yet) n: int16_t q: uint16_t i: int32_t u: uint32_t x: int64_t t: uint64_t d: double s: char * (utf8 string) o: char * (object path) As an exception, arrays of booleans are not supported, but could be added later. Other more complex types could be added later if desired. If a method has other argument types, then it must be marked as having a raw handler (see below). Internally each method can have a type specific invoker function which unpacks the incoming arguments and invokes the method handler with the correct arguments. Each method also has a finish which accepts the type-safe out arguments (ie: return values) and builds the reply message. Like other request 'finish' functions, these free the request talloc context, and are to be used in place of sbus_request_finish() or friends. Raw method handlers parse their own method arguments, and prepare their own reply (ideally using sbus_request_finish() helpers). They can also do strange things like have variable arguments. To mark a DBus method as having a raw method handler use the following annotation: <annotation name="org.freedesktop.sssd.RawHandler" value="true"/> Raw methods do not have invokers or finish functions. I've left all of the internal peer to peer communication using raw method handlers. No code changes here.

sbus: Add the sbus_request_parse_or_finish() method Some DBus types returned from dbus_message_get_args() require memory to be released when done. We automatically attach these to the talloc struct sbus_request memory context in this function. This accepts varargs similar to dbus_message_get_args(), which are rather awkward. However instead of reworking them completely, future generated marshalling code will replace most uses of these varargs. If parsing the dbus message fails, then it responds to the DBus caller with an appropriate error such as o.f.D.Error.InvalidArgs. In these cases (ie: when it returns FALSE) the sbus_request is finished. Migrated some, but not all, uses of dbus_message_get_args() to the new function. Some instances have uncommon semantics such as terminating the connection upon failure to parse a message. Reviewed-by: Jakub Hrozek <jhrozek@redhat.com> Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

sbus: Add struct sbus_request to represent a DBus invocation struct sbus_request represents a request from a dbus client being handled by a dbus server implementation. The struct contains the message, connection and method (and in the future teh property) which is being requested. In the future it will contain caller information as well. sbus_request is a talloc memory context, and is a good place to attach any allocations and memory specific to the request. Each handler accepts an sbus_request. If a handler returns EOK, it is assumed that the handler will finish the request. Any of the sbus_request_*finish() methods can be used to complete the request and send back a reply. sbus_request_return_and_finish() uses the same argument varargs syntax as dbus_message_append_args(), which isn't a great syntax. Document it a bit, but don't try to redesign: The marshalling work (will follow this patch set) will remove the need to use varargs for most DBus implementation code. This patch migrates the monitor and data provider dbus code to use sbus_request, but does not try to rework the talloc context's to use it. Reviewed-by: Jakub Hrozek <jhrozek@redhat.com> Reviewed-by: Pavel Březina <pbrezina@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>