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dbus.c
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#include <crm_internal.h>
#include <crm/crm.h>
#include <crm/services.h>
#include <dbus/dbus.h>
#include <pcmk-dbus.h>
#define BUS_PROPERTY_IFACE "org.freedesktop.DBus.Properties"
struct db_getall_data
{
char *name;
char *target;
char *object;
void *userdata;
void (*callback)(const char *name, const char *value, void *userdata);
};
static bool pcmk_dbus_error_check(DBusError *err, const char *prefix, const char *function, int line)
{
if (err && dbus_error_is_set(err)) {
do_crm_log_alias(LOG_ERR, __FILE__, function, line, "%s: DBus error '%s'", prefix, err->message);
dbus_error_free(err);
return TRUE;
}
return FALSE;
}
DBusConnection *pcmk_dbus_connect(void)
{
DBusError err;
DBusConnection *connection;
dbus_error_init(&err);
connection = dbus_bus_get(DBUS_BUS_SYSTEM, &err);
if(pcmk_dbus_error_check(&err, "Could not connect to System DBus", __FUNCTION__, __LINE__)) {
return NULL;
}
if(connection) {
pcmk_dbus_connection_setup_with_select(connection);
}
return connection;
}
void pcmk_dbus_disconnect(DBusConnection *connection)
{
}
bool
pcmk_dbus_find_error(const char *method, DBusPendingCall* pending, DBusMessage *reply, DBusError *ret)
{
DBusError error;
dbus_error_init(&error);
if(pending == NULL) {
error.name = "org.clusterlabs.pacemaker.NoRequest";
error.message = "No request sent";
} else if(reply == NULL) {
error.name = "org.clusterlabs.pacemaker.NoReply";
error.message = "No reply";
} else {
DBusMessageIter args;
int dtype = dbus_message_get_type(reply);
switch(dtype) {
case DBUS_MESSAGE_TYPE_METHOD_RETURN:
dbus_message_iter_init(reply, &args);
crm_trace("Call to %s returned '%s'", method, dbus_message_iter_get_signature(&args));
break;
case DBUS_MESSAGE_TYPE_INVALID:
error.message = "Invalid reply";
error.name = "org.clusterlabs.pacemaker.InvalidReply";
crm_err("Error processing %s response: %s", method, error.message);
break;
case DBUS_MESSAGE_TYPE_METHOD_CALL:
error.message = "Invalid reply (method call)";
error.name = "org.clusterlabs.pacemaker.InvalidReply.Method";
crm_err("Error processing %s response: %s", method, error.message);
break;
case DBUS_MESSAGE_TYPE_SIGNAL:
error.message = "Invalid reply (signal)";
error.name = "org.clusterlabs.pacemaker.InvalidReply.Signal";
crm_err("Error processing %s response: %s", method, error.message);
break;
case DBUS_MESSAGE_TYPE_ERROR:
dbus_set_error_from_message (&error, reply);
crm_info("%s error '%s': %s", method, error.name, error.message);
break;
default:
error.message = "Unknown reply type";
error.name = "org.clusterlabs.pacemaker.InvalidReply.Type";
crm_err("Error processing %s response: %s (%d)", method, error.message, dtype);
}
}
if(ret && (error.name || error.message)) {
*ret = error;
return TRUE;
}
return FALSE;
}
DBusMessage *pcmk_dbus_send_recv(DBusMessage *msg, DBusConnection *connection, DBusError *error)
{
const char *method = NULL;
DBusMessage *reply = NULL;
DBusPendingCall* pending = NULL;
CRM_ASSERT(dbus_message_get_type (msg) == DBUS_MESSAGE_TYPE_METHOD_CALL);
method = dbus_message_get_member (msg);
// send message and get a handle for a reply
if (!dbus_connection_send_with_reply (connection, msg, &pending, -1/* aka. DBUS_TIMEOUT_USE_DEFAULT */)) {
if(error) {
dbus_error_init(error);
error->message = "Call to dbus_connection_send_with_reply() failed";
error->name = "org.clusterlabs.pacemaker.SendFailed";
}
crm_err("Error sending %s request", method);
return NULL;
}
dbus_connection_flush(connection);
if(pending) {
/* block until we receive a reply */
dbus_pending_call_block(pending);
/* get the reply message */
reply = dbus_pending_call_steal_reply(pending);
}
pcmk_dbus_find_error(method, pending, reply, error);
if(pending) {
/* free the pending message handle */
dbus_pending_call_unref(pending);
}
return reply;
}
bool pcmk_dbus_send(DBusMessage *msg, DBusConnection *connection,
void(*done)(DBusPendingCall *pending, void *user_data), void *user_data)
{
DBusError error;
const char *method = NULL;
DBusPendingCall* pending = NULL;
dbus_error_init(&error);
CRM_ASSERT(done);
CRM_ASSERT(dbus_message_get_type (msg) == DBUS_MESSAGE_TYPE_METHOD_CALL);
method = dbus_message_get_member (msg);
// send message and get a handle for a reply
if (!dbus_connection_send_with_reply (connection, msg, &pending, -1/* aka. DBUS_TIMEOUT_USE_DEFAULT */)) { // -1 is default timeout
crm_err("Send with reply failed for %s", method);
return FALSE;
} else if (pending == NULL) {
crm_err("No pending call found for %s", method);
return FALSE;
}
if (done && dbus_pending_call_get_completed(pending)) {
crm_info("DBus %s call completed too soon");
#if 1
/* This sounds like a good idea, but allegedly it breaks things */
done(pending, user_data);
#else
CRM_ASSERT(dbus_pending_call_set_notify(pending, done, user_data, NULL));
#endif
} else if(done) {
CRM_ASSERT(dbus_pending_call_set_notify(pending, done, user_data, NULL));
} else {
crm_info("DBus %s call completed too soon");
}
return TRUE;
}
bool pcmk_dbus_type_check(DBusMessage *msg, DBusMessageIter *field, int expected, const char *function, int line)
{
int dtype = 0;
DBusMessageIter lfield;
if(field == NULL) {
if(dbus_message_iter_init(msg, &lfield)) {
field = &lfield;
}
}
if(field == NULL) {
do_crm_log_alias(LOG_ERR, __FILE__, function, line,
"Empty parameter list in reply expecting '%c'", expected);
return FALSE;
}
dtype = dbus_message_iter_get_arg_type(field);
if(dtype != expected) {
DBusMessageIter args;
dbus_message_iter_init(msg, &args);
do_crm_log_alias(LOG_ERR, __FILE__, function, line,
"Unexepcted DBus type, expected %c in '%s' instead of %c",
expected, dbus_message_iter_get_signature(&args), dtype);
return FALSE;
}
return TRUE;
}
static char *
pcmk_dbus_lookup_result(DBusMessage *reply, struct db_getall_data *data)
{
DBusError error;
char *output = NULL;
DBusMessageIter dict;
DBusMessageIter args;
if(pcmk_dbus_find_error("GetAll", (void*)&error, reply, &error)) {
crm_err("Cannot get properties from %s for %s", data->target, data->object);
goto cleanup;
}
dbus_message_iter_init(reply, &args);
if(!pcmk_dbus_type_check(reply, &args, DBUS_TYPE_ARRAY, __FUNCTION__, __LINE__)) {
crm_err("Invalid reply from %s for %s", data->target, data->object);
goto cleanup;
}
dbus_message_iter_recurse(&args, &dict);
while (dbus_message_iter_get_arg_type (&dict) != DBUS_TYPE_INVALID) {
DBusMessageIter sv;
DBusMessageIter v;
DBusBasicValue name;
DBusBasicValue value;
if(!pcmk_dbus_type_check(reply, &dict, DBUS_TYPE_DICT_ENTRY, __FUNCTION__, __LINE__)) {
dbus_message_iter_next (&dict);
continue;
}
dbus_message_iter_recurse(&dict, &sv);
while (dbus_message_iter_get_arg_type (&sv) != DBUS_TYPE_INVALID) {
int dtype = dbus_message_iter_get_arg_type(&sv);
switch(dtype) {
case DBUS_TYPE_STRING:
dbus_message_iter_get_basic(&sv, &name);
if(data->name && strcmp(name.str, data->name) != 0) {
dbus_message_iter_next (&sv); /* Skip the value */
}
break;
case DBUS_TYPE_VARIANT:
dbus_message_iter_recurse(&sv, &v);
if(pcmk_dbus_type_check(reply, &v, DBUS_TYPE_STRING, __FUNCTION__, __LINE__)) {
dbus_message_iter_get_basic(&v, &value);
crm_trace("Property %s[%s] is '%s'", data->object, name.str, value.str);
if(data->callback) {
data->callback(name.str, value.str, data->userdata);
} else {
output = strdup(value.str);
}
if(data->name) {
goto cleanup;
}
}
break;
default:
pcmk_dbus_type_check(reply, &sv, DBUS_TYPE_STRING, __FUNCTION__, __LINE__);
}
dbus_message_iter_next (&sv);
}
dbus_message_iter_next (&dict);
}
cleanup:
free(data->target);
free(data->object);
free(data->name);
free(data);
return output;
}
static void
pcmk_dbus_lookup_cb(DBusPendingCall *pending, void *user_data)
{
DBusMessage *reply = NULL;
if(pending) {
reply = dbus_pending_call_steal_reply(pending);
}
pcmk_dbus_lookup_result(reply, user_data);
if(reply) {
dbus_message_unref(reply);
}
}
char *
pcmk_dbus_get_property(
DBusConnection *connection, const char *target, const char *obj, const gchar * iface, const char *name,
void (*callback)(const char *name, const char *value, void *userdata), void *userdata)
{
DBusMessage *msg;
const char *method = "GetAll";
char *output = NULL;
struct db_getall_data *query_data = NULL;
/* char *state = pcmk_dbus_get_property(systemd_proxy, BUS_NAME, unit, BUS_NAME ".Unit", "ActiveState"); */
crm_debug("Calling: %s on %s", method, target);
msg = dbus_message_new_method_call(target, // target for the method call
obj, // object to call on
BUS_PROPERTY_IFACE, // interface to call on
method); // method name
if (NULL == msg) {
crm_err("Call to %s failed: No message", method);
return NULL;
}
CRM_LOG_ASSERT(dbus_message_append_args(msg, DBUS_TYPE_STRING, &iface, DBUS_TYPE_INVALID));
query_data = malloc(sizeof(struct db_getall_data));
if(query_data == NULL) {
crm_err("Call to %s failed: malloc failed", method);
return NULL;
}
query_data->target = strdup(target);
query_data->object = strdup(obj);
query_data->callback = callback;
query_data->userdata = userdata;
query_data->name = NULL;
if(name) {
query_data->name = strdup(name);
}
if(query_data->callback) {
pcmk_dbus_send(msg, connection, pcmk_dbus_lookup_cb, query_data);
} else {
DBusMessage *reply = pcmk_dbus_send_recv(msg, connection, NULL);
output = pcmk_dbus_lookup_result(reply, query_data);
if(reply) {
dbus_message_unref(reply);
}
}
dbus_message_unref(msg);
return output;
}
static void pcmk_dbus_connection_dispatch(DBusConnection *connection, DBusDispatchStatus new_status, void *data){
crm_trace("status %d for %p", new_status, data);
if (new_status == DBUS_DISPATCH_DATA_REMAINS){
dbus_connection_dispatch(connection);
}
}
static int
pcmk_dbus_watch_dispatch(gpointer userdata)
{
DBusWatch *watch = userdata;
int flags = dbus_watch_get_flags(watch);
crm_trace("Dispatching %p with flags %d", watch, flags);
if(flags & DBUS_WATCH_READABLE) {
dbus_watch_handle(watch, DBUS_WATCH_READABLE);
} else {
dbus_watch_handle(watch, DBUS_WATCH_ERROR);
}
return 0;
}
static void
pcmk_dbus_watch_destroy(gpointer userdata)
{
crm_trace("Destroyed %p", userdata);
}
struct mainloop_fd_callbacks pcmk_dbus_cb = {
.dispatch = pcmk_dbus_watch_dispatch,
.destroy = pcmk_dbus_watch_destroy,
};
static dbus_bool_t
pcmk_dbus_watch_add(DBusWatch *watch, void *data){
int fd = dbus_watch_get_unix_fd(watch);
mainloop_io_t *client = mainloop_add_fd(
"dbus", G_PRIORITY_DEFAULT, fd, watch, &pcmk_dbus_cb);
crm_trace("Added %p with fd=%d", watch, fd);
dbus_watch_set_data(watch, client, NULL);
return TRUE;
}
static void
pcmk_dbus_watch_toggle(DBusWatch *watch, void *data)
{
mainloop_io_t *client = dbus_watch_get_data(watch);
crm_notice("DBus client %p is now %s", client, dbus_watch_get_enabled(watch)?"enabled":"disabled");
}
static void
pcmk_dbus_watch_remove(DBusWatch *watch, void *data){
mainloop_io_t *client = dbus_watch_get_data(watch);
crm_trace("Removed %p", watch);
mainloop_del_fd(client);
}
static gboolean
pcmk_dbus_timeout_dispatch(gpointer data)
{
crm_trace("Timeout for %p");
dbus_timeout_handle(data);
return FALSE;
}
static dbus_bool_t
pcmk_dbus_timeout_add(DBusTimeout *timeout, void *data){
guint id = g_timeout_add(dbus_timeout_get_interval(timeout), pcmk_dbus_timeout_dispatch, timeout);
if(id) {
dbus_timeout_set_data(timeout, GUINT_TO_POINTER(id), NULL);
}
return TRUE;
}
static void
pcmk_dbus_timeout_remove(DBusTimeout *timeout, void *data){
void *vid = dbus_timeout_get_data(timeout);
guint id = GPOINTER_TO_UINT(vid);
if(id) {
g_source_remove(id);
dbus_timeout_set_data(timeout, 0, NULL);
}
}
static void
pcmk_dbus_timeout_toggle(DBusTimeout *timeout, void *data){
if(dbus_timeout_get_enabled(timeout)) {
pcmk_dbus_timeout_add(timeout, data);
} else {
pcmk_dbus_timeout_remove(timeout, data);
}
}
/* Inspired by http://www.kolej.mff.cuni.cz/~vesej3am/devel/dbus-select.c */
void pcmk_dbus_connection_setup_with_select(DBusConnection *c){
dbus_connection_set_timeout_functions(
c, pcmk_dbus_timeout_add, pcmk_dbus_timeout_remove, pcmk_dbus_timeout_toggle, NULL, NULL);
dbus_connection_set_watch_functions(c, pcmk_dbus_watch_add, pcmk_dbus_watch_remove, pcmk_dbus_watch_toggle, NULL, NULL);
dbus_connection_set_dispatch_status_function(c, pcmk_dbus_connection_dispatch, NULL, NULL);
pcmk_dbus_connection_dispatch(c, dbus_connection_get_dispatch_status(c), NULL);
}

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