asterisk/res/res_stasis_device_state.c

491 lines
13 KiB
C
Raw Normal View History

2023-05-25 18:45:57 +00:00
/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2013, Digium, Inc.
*
* Kevin Harwell <kharwell@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*** MODULEINFO
<depend type="module">res_stasis</depend>
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/astdb.h"
#include "asterisk/astobj2.h"
#include "asterisk/module.h"
#include "asterisk/stasis_app_impl.h"
#include "asterisk/stasis_app_device_state.h"
#define DEVICE_STATE_SIZE 64
/*! astdb family name */
#define DEVICE_STATE_FAMILY "StasisDeviceState"
/*! Stasis device state provider */
#define DEVICE_STATE_PROVIDER_STASIS "Stasis"
/*! Scheme for custom device states */
#define DEVICE_STATE_SCHEME_STASIS "Stasis:"
/*! Scheme for device state subscriptions */
#define DEVICE_STATE_SCHEME_SUB "deviceState:"
/*! Number of hash buckets for device state subscriptions */
#define DEVICE_STATE_BUCKETS 37
/*! The key used for tracking a subscription to all device states */
#define DEVICE_STATE_ALL "__AST_DEVICE_STATE_ALL_TOPIC"
/*! Container for subscribed device states */
static struct ao2_container *device_state_subscriptions;
/*!
* \brief Device state subscription object.
*/
struct device_state_subscription {
AST_DECLARE_STRING_FIELDS(
AST_STRING_FIELD(app_name);
AST_STRING_FIELD(device_name);
);
/*! The subscription object */
struct stasis_subscription *sub;
};
static int device_state_subscriptions_hash(const void *obj, const int flags)
{
const struct device_state_subscription *object;
switch (flags & OBJ_SEARCH_MASK) {
case OBJ_SEARCH_OBJECT:
object = obj;
return ast_str_hash(object->device_name);
case OBJ_SEARCH_KEY:
default:
/* Hash can only work on something with a full key. */
ast_assert(0);
return 0;
}
}
static int device_state_subscriptions_cmp(void *obj, void *arg, int flags)
{
const struct device_state_subscription *object_left = obj;
const struct device_state_subscription *object_right = arg;
int cmp;
switch (flags & OBJ_SEARCH_MASK) {
case OBJ_SEARCH_OBJECT:
/* find objects matching both device and app names */
if (strcmp(object_left->device_name,
object_right->device_name)) {
return 0;
}
cmp = strcmp(object_left->app_name, object_right->app_name);
break;
case OBJ_SEARCH_KEY:
case OBJ_SEARCH_PARTIAL_KEY:
ast_assert(0); /* not supported by container */
/* fall through */
default:
cmp = 0;
break;
}
return cmp ? 0 : CMP_MATCH | CMP_STOP;
}
static void device_state_subscription_destroy(void *obj)
{
struct device_state_subscription *sub = obj;
ast_string_field_free_memory(sub);
}
static struct device_state_subscription *device_state_subscription_create(
const struct stasis_app *app, const char *device_name)
{
struct device_state_subscription *sub;
const char *app_name = stasis_app_name(app);
size_t size;
if (ast_strlen_zero(device_name)) {
device_name = DEVICE_STATE_ALL;
}
size = strlen(device_name) + strlen(app_name) + 2;
sub = ao2_alloc(sizeof(*sub), device_state_subscription_destroy);
if (!sub) {
return NULL;
}
if (ast_string_field_init(sub, size)) {
ao2_ref(sub, -1);
return NULL;
}
ast_string_field_set(sub, app_name, app_name);
ast_string_field_set(sub, device_name, device_name);
return sub;
}
static struct device_state_subscription *find_device_state_subscription(
struct stasis_app *app, const char *name)
{
struct device_state_subscription dummy_sub = {
.app_name = stasis_app_name(app),
.device_name = name
};
return ao2_find(device_state_subscriptions, &dummy_sub, OBJ_SEARCH_OBJECT | OBJ_NOLOCK);
}
static void remove_device_state_subscription(
struct device_state_subscription *sub)
{
if (sub->sub) {
sub->sub = stasis_unsubscribe_and_join(sub->sub);
}
ao2_unlink_flags(device_state_subscriptions, sub, OBJ_NOLOCK);
}
struct ast_json *stasis_app_device_state_to_json(
const char *name, enum ast_device_state state)
{
return ast_json_pack("{s: s, s: s}",
"name", name,
"state", ast_devstate_str(state));
}
struct ast_json *stasis_app_device_states_to_json(void)
{
struct ast_json *array = ast_json_array_create();
struct ast_db_entry *tree;
struct ast_db_entry *entry;
tree = ast_db_gettree(DEVICE_STATE_FAMILY, NULL);
for (entry = tree; entry; entry = entry->next) {
const char *name = strrchr(entry->key, '/');
if (!ast_strlen_zero(name)) {
char device[DEVICE_STATE_SIZE];
snprintf(device, sizeof(device), "%s%s", DEVICE_STATE_SCHEME_STASIS, ++name);
ast_json_array_append(array,
stasis_app_device_state_to_json(device, ast_device_state(device)));
}
}
ast_db_freetree(tree);
return array;
}
static void send_device_state(struct device_state_subscription *sub,
const char *name, enum ast_device_state state)
{
RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
json = ast_json_pack("{s:s, s:s, s:o, s:o}",
"type", "DeviceStateChanged",
"application", sub->app_name,
"timestamp", ast_json_timeval(ast_tvnow(), NULL),
"device_state", stasis_app_device_state_to_json(
name, state));
if (!json) {
ast_log(LOG_ERROR, "Unable to create device state json object\n");
return;
}
stasis_app_send(sub->app_name, json);
}
enum stasis_device_state_result stasis_app_device_state_update(
const char *name, const char *value)
{
size_t size = strlen(DEVICE_STATE_SCHEME_STASIS);
enum ast_device_state state;
ast_debug(3, "Updating device name = %s, value = %s", name, value);
if (strncasecmp(name, DEVICE_STATE_SCHEME_STASIS, size)) {
ast_log(LOG_ERROR, "Update can only be used to set "
"'%s' device state!\n", DEVICE_STATE_SCHEME_STASIS);
return STASIS_DEVICE_STATE_NOT_CONTROLLED;
}
name += size;
if (ast_strlen_zero(name)) {
ast_log(LOG_ERROR, "Update requires custom device name!\n");
return STASIS_DEVICE_STATE_MISSING;
}
if (!value || (state = ast_devstate_val(value)) == AST_DEVICE_UNKNOWN) {
ast_log(LOG_ERROR, "Unknown device state "
"value '%s'\n", value);
return STASIS_DEVICE_STATE_UNKNOWN;
}
ast_db_put(DEVICE_STATE_FAMILY, name, value);
ast_devstate_changed(state, AST_DEVSTATE_CACHABLE, "%s%s",
DEVICE_STATE_SCHEME_STASIS, name);
return STASIS_DEVICE_STATE_OK;
}
enum stasis_device_state_result stasis_app_device_state_delete(const char *name)
{
const char *full_name = name;
size_t size = strlen(DEVICE_STATE_SCHEME_STASIS);
if (strncasecmp(name, DEVICE_STATE_SCHEME_STASIS, size)) {
ast_log(LOG_ERROR, "Can only delete '%s' device states!\n",
DEVICE_STATE_SCHEME_STASIS);
return STASIS_DEVICE_STATE_NOT_CONTROLLED;
}
name += size;
if (ast_strlen_zero(name)) {
ast_log(LOG_ERROR, "Delete requires a device name!\n");
return STASIS_DEVICE_STATE_MISSING;
}
if (ast_device_state_clear_cache(full_name)) {
return STASIS_DEVICE_STATE_UNKNOWN;
}
ast_db_del(DEVICE_STATE_FAMILY, name);
/* send state change for delete */
ast_devstate_changed(
AST_DEVICE_UNKNOWN, AST_DEVSTATE_CACHABLE, "%s%s",
DEVICE_STATE_SCHEME_STASIS, name);
return STASIS_DEVICE_STATE_OK;
}
static void populate_cache(void)
{
RAII_VAR(struct ast_db_entry *, tree,
ast_db_gettree(DEVICE_STATE_FAMILY, NULL), ast_db_freetree);
struct ast_db_entry *entry;
for (entry = tree; entry; entry = entry->next) {
const char *name = strrchr(entry->key, '/');
if (!ast_strlen_zero(name)) {
ast_devstate_changed(
ast_devstate_val(entry->data),
AST_DEVSTATE_CACHABLE, "%s%s\n",
DEVICE_STATE_SCHEME_STASIS, name + 1);
}
}
}
static enum ast_device_state stasis_device_state_cb(const char *data)
{
char buf[DEVICE_STATE_SIZE];
ast_db_get(DEVICE_STATE_FAMILY, data, buf, sizeof(buf));
return ast_devstate_val(buf);
}
static void device_state_cb(void *data, struct stasis_subscription *sub,
struct stasis_message *msg)
{
struct ast_device_state_message *device_state;
if (stasis_subscription_final_message(sub, msg)) {
/* Remove stasis subscription's reference to device_state_subscription */
ao2_ref(data, -1);
return;
}
if (ast_device_state_message_type() != stasis_message_type(msg)) {
return;
}
device_state = stasis_message_data(msg);
if (device_state->eid) {
/* ignore non-aggregate states */
return;
}
send_device_state(data, device_state->device, device_state->state);
}
static void *find_device_state(const struct stasis_app *app, const char *name)
{
return device_state_subscription_create(app, name);
}
static int is_subscribed_device_state(struct stasis_app *app, const char *name)
{
struct device_state_subscription *sub;
sub = find_device_state_subscription(app, DEVICE_STATE_ALL);
if (sub) {
ao2_ref(sub, -1);
return 1;
}
sub = find_device_state_subscription(app, name);
if (sub) {
ao2_ref(sub, -1);
return 1;
}
return 0;
}
static int is_subscribed_device_state_lock(struct stasis_app *app, const char *name)
{
int is_subscribed;
ao2_lock(device_state_subscriptions);
is_subscribed = is_subscribed_device_state(app, name);
ao2_unlock(device_state_subscriptions);
return is_subscribed;
}
static int subscribe_device_state(struct stasis_app *app, void *obj)
{
struct device_state_subscription *sub = obj;
struct stasis_topic *topic;
if (!sub) {
sub = device_state_subscription_create(app, NULL);
if (!sub) {
return -1;
}
}
if (strcmp(sub->device_name, DEVICE_STATE_ALL)) {
topic = ast_device_state_topic(sub->device_name);
} else {
topic = ast_device_state_topic_all();
}
ao2_lock(device_state_subscriptions);
if (is_subscribed_device_state(app, sub->device_name)) {
ao2_unlock(device_state_subscriptions);
ast_debug(3, "App %s is already subscribed to %s\n", stasis_app_name(app), sub->device_name);
return 0;
}
ast_debug(3, "Subscribing to device %s\n", sub->device_name);
sub->sub = stasis_subscribe_pool(topic, device_state_cb, ao2_bump(sub));
if (!sub->sub) {
ao2_unlock(device_state_subscriptions);
ast_log(LOG_ERROR, "Unable to subscribe to device %s\n",
sub->device_name);
/* Reference we added when attempting to stasis_subscribe_pool */
ao2_ref(sub, -1);
return -1;
}
stasis_subscription_accept_message_type(sub->sub, ast_device_state_message_type());
stasis_subscription_accept_message_type(sub->sub, stasis_subscription_change_type());
stasis_subscription_set_filter(sub->sub, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);
ao2_link_flags(device_state_subscriptions, sub, OBJ_NOLOCK);
ao2_unlock(device_state_subscriptions);
return 0;
}
static int unsubscribe_device_state(struct stasis_app *app, const char *name)
{
struct device_state_subscription *sub;
ao2_lock(device_state_subscriptions);
sub = find_device_state_subscription(app, name);
if (sub) {
remove_device_state_subscription(sub);
}
ao2_unlock(device_state_subscriptions);
ao2_cleanup(sub);
return 0;
}
static int device_to_json_cb(void *obj, void *arg, void *data, int flags)
{
struct device_state_subscription *sub = obj;
const char *app_name = arg;
struct ast_json *array = data;
if (strcmp(sub->app_name, app_name)) {
return 0;
}
ast_json_array_append(
array, ast_json_string_create(sub->device_name));
return 0;
}
static void devices_to_json(const struct stasis_app *app, struct ast_json *json)
{
struct ast_json *array = ast_json_array_create();
ao2_callback_data(device_state_subscriptions, OBJ_NODATA,
device_to_json_cb, (void *)stasis_app_name(app), array);
ast_json_object_set(json, "device_names", array);
}
struct stasis_app_event_source device_state_event_source = {
.scheme = DEVICE_STATE_SCHEME_SUB,
.find = find_device_state,
.subscribe = subscribe_device_state,
.unsubscribe = unsubscribe_device_state,
.is_subscribed = is_subscribed_device_state_lock,
.to_json = devices_to_json
};
static int load_module(void)
{
populate_cache();
if (ast_devstate_prov_add(DEVICE_STATE_PROVIDER_STASIS,
stasis_device_state_cb)) {
return AST_MODULE_LOAD_DECLINE;
}
device_state_subscriptions = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
DEVICE_STATE_BUCKETS, device_state_subscriptions_hash, NULL,
device_state_subscriptions_cmp);
if (!device_state_subscriptions) {
ast_devstate_prov_del(DEVICE_STATE_PROVIDER_STASIS);
return AST_MODULE_LOAD_DECLINE;
}
stasis_app_register_event_source(&device_state_event_source);
return AST_MODULE_LOAD_SUCCESS;
}
static int unload_module(void)
{
ast_devstate_prov_del(DEVICE_STATE_PROVIDER_STASIS);
stasis_app_unregister_event_source(&device_state_event_source);
ao2_cleanup(device_state_subscriptions);
device_state_subscriptions = NULL;
return 0;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS, "Stasis application device state support",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.requires = "res_stasis",
);