ladish/dbus/method.c

592 lines
15 KiB
C

/*
* LASH
*
* Copyright (C) 2008 Juuso Alasuutari <juuso.alasuutari@gmail.com>
* Copyright (C) 2008 Nedko Arnaudov
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "../common/safety.h"
#include "../common/debug.h"
#include "method.h"
#include "service.h"
/*
* Construct a void method return.
*
* The operation can only fail due to lack of memory, in which case
* there's no sense in trying to construct an error return. Instead,
* call->reply will be set to NULL and handled in send_method_return().
*/
void
method_return_new_void(method_call_t *call)
{
if (!(call->reply = dbus_message_new_method_return(call->message))) {
lash_error("Ran out of memory trying to construct method return");
}
}
/*
* Construct a method return which holds a single argument or, if
* the type parameter is DBUS_TYPE_INVALID, no arguments at all
* (a void message).
*
* The operation can only fail due to lack of memory, in which case
* there's no sense in trying to construct an error return. Instead,
* call->reply will be set to NULL and handled in send_method_return().
*/
void
method_return_new_single(method_call_t *call,
int type,
const void *arg)
{
if (!call || !arg) {
lash_error("Invalid arguments");
return;
}
call->reply = dbus_message_new_method_return(call->message);
if (!call->reply)
goto fail_no_mem;
/* Void method return requested by caller. */
// TODO: do we really need this?
if (type == DBUS_TYPE_INVALID)
return;
/* Prevent crash on NULL input string. */
if (type == DBUS_TYPE_STRING && !(*((const char **) arg)))
*((const char **) arg) = "";
DBusMessageIter iter;
dbus_message_iter_init_append(call->reply, &iter);
if (dbus_message_iter_append_basic(&iter, type, arg))
return;
dbus_message_unref(call->reply);
call->reply = NULL;
fail_no_mem:
lash_error("Ran out of memory trying to construct method return");
}
void
method_return_new_valist(method_call_t *call,
int type,
...)
{
if (!call) {
lash_error("Call pointer is NULL");
return;
}
if (type == DBUS_TYPE_INVALID) {
lash_error("No argument(s) supplied");
return;
}
va_list argp;
call->reply = dbus_message_new_method_return(call->message);
if (!call->reply)
goto fail_no_mem;
va_start(argp, type);
if (dbus_message_append_args_valist(call->reply, type, argp)) {
va_end(argp);
return;
}
va_end(argp);
dbus_message_unref(call->reply);
call->reply = NULL;
fail_no_mem:
lash_error("Ran out of memory trying to construct method return");
}
/*
* Send a method call.
*/
bool
method_send(method_msg_t *call,
bool will_block)
{
if (!call->message) {
lash_error("Cannot send method call: Message is NULL");
return false;
}
DBusPendingCall *pending = NULL;
bool retval;
if (!dbus_connection_send_with_reply(call->service->connection,
call->message, &pending, -1)) {
lash_error("Ran out of memory trying to queue "
"method call");
retval = false;
/* Never wait for a reply if sending failed */
will_block = false;
} else {
if (pending)
dbus_pending_call_set_notify(pending,
call->return_handler,
call->context, NULL);
dbus_connection_flush(call->service->connection);
retval = true;
}
dbus_message_unref(call->message);
call->message = NULL;
if (will_block && pending) {
lash_debug("Blocking until a return arrives");
dbus_pending_call_block(pending);
}
return retval;
}
/*
* Send a method return.
*
* If call->reply is NULL, i.e. a previous attempt to construct
* a return has failed, attempt to send a void return.
*/
void
method_return_send(method_call_t *call)
{
if (call->reply) {
retry_send:
if (!dbus_connection_send(call->connection, call->reply, NULL))
lash_error("Ran out of memory trying to queue "
"method return");
else
dbus_connection_flush(call->connection);
dbus_message_unref(call->reply);
call->reply = NULL;
} else {
lash_debug("Message was NULL, trying to construct a void return");
if ((call->reply = dbus_message_new_method_return(call->message))) {
lash_debug("Constructed a void return, trying to queue it");
goto retry_send;
} else {
lash_error("Failed to construct method return!");
}
}
}
bool
method_return_verify(DBusMessage *msg,
const char **str)
{
if (!msg || dbus_message_get_type(msg) != DBUS_MESSAGE_TYPE_ERROR)
return true;
DBusError err;
const char *ptr;
dbus_error_init(&err);
if (!dbus_message_get_args(msg, &err,
DBUS_TYPE_STRING, &ptr,
DBUS_TYPE_INVALID)) {
lash_error("Cannot read description from D-Bus error message: %s ",
err.message);
dbus_error_free(&err);
ptr = NULL;
}
if (str)
*str = ptr;
return false;
}
/*
* Append a variant type to a D-Bus message.
* Return false if something fails, true otherwise.
*/
bool
method_iter_append_variant(DBusMessageIter *iter,
int type,
const void *arg)
{
DBusMessageIter sub_iter;
char s[2];
s[0] = (char) type;
s[1] = '\0';
/* Open a variant container. */
if (!dbus_message_iter_open_container(iter, DBUS_TYPE_VARIANT,
(const char *) s, &sub_iter))
return false;
/* Append the supplied value. */
if (!dbus_message_iter_append_basic(&sub_iter, type, arg)) {
dbus_message_iter_close_container(iter, &sub_iter);
return false;
}
/* Close the container. */
if (!dbus_message_iter_close_container(iter, &sub_iter))
return false;
return true;
}
static __inline__ bool
method_iter_append_variant_raw(DBusMessageIter *iter,
const void *buf,
int len)
{
DBusMessageIter variant_iter, array_iter;
/* Open a variant container. */
if (!dbus_message_iter_open_container(iter, DBUS_TYPE_VARIANT,
"ay", &variant_iter))
return false;
/* Open an array container. */
if (!dbus_message_iter_open_container(&variant_iter, DBUS_TYPE_ARRAY,
"y", &array_iter))
goto fail;
/* Append the supplied data. */
if (!dbus_message_iter_append_fixed_array(&array_iter, DBUS_TYPE_BYTE, buf, len)) {
dbus_message_iter_close_container(&variant_iter, &array_iter);
goto fail;
}
/* Close the containers. */
if (!dbus_message_iter_close_container(&variant_iter, &array_iter))
goto fail;
else if (!dbus_message_iter_close_container(iter, &variant_iter))
return false;
return true;
fail:
dbus_message_iter_close_container(iter, &variant_iter);
return false;
}
bool
method_iter_append_dict_entry(DBusMessageIter *iter,
int type,
const char *key,
const void *value,
int length)
{
DBusMessageIter dict_iter;
if (!dbus_message_iter_open_container(iter, DBUS_TYPE_DICT_ENTRY,
NULL, &dict_iter))
return false;
if (!dbus_message_iter_append_basic(&dict_iter, DBUS_TYPE_STRING, &key))
goto fail;
if (type == '-') {
if (!method_iter_append_variant_raw(&dict_iter, value, length))
goto fail;
} else if (!method_iter_append_variant(&dict_iter, type, value))
goto fail;
if (!dbus_message_iter_close_container(iter, &dict_iter))
return false;
return true;
fail:
dbus_message_iter_close_container(iter, &dict_iter);
return false;
}
void
method_default_handler(DBusPendingCall *pending,
void *data)
{
DBusMessage *msg = dbus_pending_call_steal_reply(pending);
if (msg) {
const char *err_str;
if (!method_return_verify(msg, &err_str))
lash_error("%s", err_str);
dbus_message_unref(msg);
} else
lash_error("Cannot get method return from pending call");
dbus_pending_call_unref(pending);
}
bool
method_call_init(method_msg_t *call,
service_t *service,
void *return_context,
DBusPendingCallNotifyFunction return_handler,
const char *destination,
const char *path,
const char *interface,
const char *method)
{
if (!call || !service || !service->connection
|| !destination || !path || !method) {
lash_error("Invalid arguments");
return false;
}
if (!interface)
interface = "";
call->message = dbus_message_new_method_call(destination, path,
interface, method);
if (!call->message) {
lash_error("Ran out of memory trying to create "
"new method call");
return false;
}
call->service = service;
call->context = return_context;
call->return_handler = return_handler;
if (!return_handler)
dbus_message_set_no_reply(call->message, true);
return true;
}
bool
method_call_new_void(service_t *service,
void *return_context,
DBusPendingCallNotifyFunction return_handler,
bool will_block,
const char *destination,
const char *path,
const char *interface,
const char *method)
{
method_msg_t call;
if (method_call_init(&call, service, return_context, return_handler,
destination, path, interface, method))
return method_send(&call, will_block);
return false;
}
bool
method_call_new_single(service_t *service,
void *return_context,
DBusPendingCallNotifyFunction return_handler,
bool will_block,
const char *destination,
const char *path,
const char *interface,
const char *method,
int type,
const void *arg)
{
if (type == DBUS_TYPE_INVALID || !arg) {
lash_error("No argument supplied");
return false;
}
method_msg_t call;
DBusMessageIter iter;
if (!method_call_init(&call, service, return_context, return_handler,
destination, path, interface, method))
return false;
dbus_message_iter_init_append(call.message, &iter);
if (dbus_message_iter_append_basic(&iter, type, arg)) {
return method_send(&call, will_block);
}
lash_error("Ran out of memory trying to append method call argument");
dbus_message_unref(call.message);
call.message = NULL;
return false;
}
bool
method_call_new_valist(service_t *service,
void *return_context,
DBusPendingCallNotifyFunction return_handler,
bool will_block,
const char *destination,
const char *path,
const char *interface,
const char *method,
int type,
...)
{
if (type == DBUS_TYPE_INVALID) {
lash_error("No argument(s) supplied");
return false;
}
method_msg_t call;
va_list argp;
if (!method_call_init(&call, service, return_context, return_handler,
destination, path, interface, method))
return false;
va_start(argp, type);
if (dbus_message_append_args_valist(call.message, type, argp)) {
va_end(argp);
return method_send(&call, will_block);
}
va_end(argp);
lash_error("Ran out of memory trying to append "
"method call argument(s)");
dbus_message_unref(call.message);
call.message = NULL;
return false;
}
bool
method_iter_get_args(DBusMessageIter *iter,
...)
{
if (!iter) {
lash_error("Iterator pointer is NULL");
return false;
}
va_list argp;
int expected_type, type, n = 0;
void *ptr;
va_start(argp, iter);
while ((expected_type = va_arg(argp, int)) != DBUS_TYPE_INVALID) {
ptr = va_arg(argp, void *);
if ((type = dbus_message_iter_get_arg_type(iter))
== DBUS_TYPE_INVALID) {
lash_error("Insufficient arguments");
va_end(argp);
return false;
}
if (type != expected_type) {
lash_error("Invalid type for argument %i", n);
va_end(argp);
return false;
}
if (ptr)
dbus_message_iter_get_basic(iter, ptr);
dbus_message_iter_next(iter);
++n;
}
va_end(argp);
return true;
}
bool
method_iter_get_dict_entry(DBusMessageIter *iter,
const char **key_ptr,
void *value_ptr,
int *type_ptr,
int *size_ptr)
{
if (!iter || !key_ptr || !value_ptr || !type_ptr) {
lash_error("Invalid arguments");
return false;
}
DBusMessageIter dict_iter, variant_iter;
if (dbus_message_iter_get_arg_type(iter) != DBUS_TYPE_DICT_ENTRY) {
lash_error("Iterator does not point to a dict entry container");
return false;
}
dbus_message_iter_recurse(iter, &dict_iter);
if (dbus_message_iter_get_arg_type(&dict_iter) != DBUS_TYPE_STRING) {
lash_error("Cannot find key in dict entry container");
return false;
}
dbus_message_iter_get_basic(&dict_iter, key_ptr);
if (!dbus_message_iter_next(&dict_iter)
|| dbus_message_iter_get_arg_type(&dict_iter) != DBUS_TYPE_VARIANT) {
lash_error("Cannot find variant container in dict entry");
return false;
}
dbus_message_iter_recurse(&dict_iter, &variant_iter);
*type_ptr = dbus_message_iter_get_arg_type(&variant_iter);
if (*type_ptr == DBUS_TYPE_INVALID) {
lash_error("Cannot find value in variant container");
return false;
}
if (*type_ptr == DBUS_TYPE_ARRAY) {
DBusMessageIter array_iter;
int n;
if (dbus_message_iter_get_element_type(&variant_iter)
!= DBUS_TYPE_BYTE) {
lash_error("Dict entry value is a non-byte array");
return false;
}
*type_ptr = '-';
dbus_message_iter_recurse(&variant_iter, &array_iter);
dbus_message_iter_get_fixed_array(&array_iter, value_ptr, &n);
if (size_ptr)
*size_ptr = n;
} else
dbus_message_iter_get_basic(&variant_iter, value_ptr);
return true;
}
/* EOF */