ari_websockets.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@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.
 */
 
#include "asterisk.h"
 
#include "resource_events.h"
#include "ari_websockets.h"
#include "internal.h"
#include "ari_model_validators.h"
#include "asterisk/app.h"
#include "asterisk/ari.h"
#include "asterisk/astobj2.h"
#include "asterisk/http_websocket.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/stasis_app.h"
#include "asterisk/time.h"
#include "asterisk/uuid.h"
#include "asterisk/vector.h"
#include "asterisk/websocket_client.h"
 
 
/*! \file
 *
 * \brief WebSocket support for RESTful API's.
 * \author David M. Lee, II <dlee@digium.com>
 */
 
/*! Number of buckets for the ari_ws_session registry. Remember to keep it a prime number! */
#define SESSION_REGISTRY_NUM_BUCKETS 23
 
/*! Initial size of websocket session apps vector */
#define APPS_INIT_SIZE 7
 
/*! Initial size of the websocket session message queue. */
#define MESSAGES_INIT_SIZE 23
 
#define ARI_CONTEXT_REGISTRAR "res_ari"
 
/*! \brief Local registry for created \ref ari_ws_session objects. */
static struct ao2_container *session_registry;
 
struct ast_websocket_server *ast_ws_server;
 
#if defined(AST_DEVMODE)
    ari_validator ari_validate_message_fn = ast_ari_validate_message;
#else
    /*!
     * \brief Validator that always succeeds.
     */
    static int null_validator(struct ast_json *json)
    {
        return 1;
    }
 
    ari_validator ari_validate_message_fn = null_validator;
#endif
 
 
#define VALIDATION_FAILED               \
    "{"                     \
    "  \"error\": \"InvalidMessage\","      \
    "  \"message\": \"Message validation failed\""  \
    "}"
 
static int session_write(struct ari_ws_session *session, struct ast_json *message)
{
    RAII_VAR(char *, str, NULL, ast_json_free);
 
    if (!session || !session->ast_ws_session || !message) {
        return -1;
    }
 
#ifdef AST_DEVMODE
    if (!session->validator(message)) {
        ast_log(LOG_ERROR, "Outgoing message failed validation\n");
        return ast_websocket_write_string(session->ast_ws_session, VALIDATION_FAILED);
    }
#endif
 
    str = ast_json_dump_string_format(message, ast_ari_json_format());
 
    if (str == NULL) {
        ast_log(LOG_ERROR, "Failed to encode JSON object\n");
        return -1;
    }
 
    if (ast_websocket_write_string(session->ast_ws_session, str)) {
        ast_log(LOG_NOTICE, "Problem occurred during websocket write to %s, websocket closed\n",
            ast_sockaddr_stringify(ast_websocket_remote_address(session->ast_ws_session)));
        return -1;
    }
    return 0;
}
 
static void session_send_or_queue(struct ari_ws_session *session,
    struct ast_json *message, const char *msg_type, const char *app_name,
    int debug_app)
{
    const char *msg_timestamp, *msg_ast_id;
 
    msg_timestamp = S_OR(
        ast_json_string_get(ast_json_object_get(message, "timestamp")), "");
    if (ast_strlen_zero(msg_timestamp)) {
        if (ast_json_object_set(message, "timestamp", ast_json_timeval(ast_tvnow(), NULL))) {
            ast_log(LOG_ERROR,
                "%s: Failed to dispatch '%s' message from Stasis app '%s'; could not update message\n",
                session->remote_addr, msg_type, app_name);
            return;
        }
    }
 
    msg_ast_id = S_OR(
        ast_json_string_get(ast_json_object_get(message, "asterisk_id")), "");
    if (ast_strlen_zero(msg_ast_id)) {
        char eid[20];
 
        if (ast_json_object_set(message, "asterisk_id",
            ast_json_string_create(ast_eid_to_str(eid, sizeof(eid), &ast_eid_default)))) {
            ao2_unlock(session);
            ast_log(LOG_ERROR,
                "%s: Failed to dispatch '%s' message from Stasis app '%s'; could not update message\n",
                session->remote_addr, msg_type, app_name);
        }
    }
 
    if (!session->ast_ws_session) {
        /* If the websocket is NULL, the message goes to the queue */
        if (AST_VECTOR_APPEND(&session->message_queue, message) == 0) {
            ast_json_ref(message);
        }
        /*
         * If the msg_type one of the Application* types, the websocket
         * might not be there yet so don't log.
         */
        if (!ast_begins_with(msg_type, "Application")) {
            ast_log(LOG_WARNING,
                    "%s: Queued '%s' message for Stasis app '%s'; websocket is not ready\n",
                    session->remote_addr,
                    msg_type,
                    app_name);
        }
    } else {
 
        if (DEBUG_ATLEAST(4) || debug_app) {
            char *str = ast_json_dump_string_format(message, AST_JSON_PRETTY);
 
            ast_verbose("<--- Sending ARI event to %s --->\n%s\n",
                session->remote_addr,
                str);
            ast_json_free(str);
        }
        session_write(session, message);
    }
}
 
static void session_send_app_event(struct ari_ws_session *session,
    const char *event_type, const char *app_name)
{
    char eid[20];
    int debug_app = stasis_app_get_debug_by_name(app_name);
    struct ast_json *msg = ast_json_pack("{s:s, s:o?, s:s, s:s }",
        "type", event_type,
        "timestamp", ast_json_timeval(ast_tvnow(), NULL),
        "application", app_name,
        "asterisk_id", ast_eid_to_str(eid, sizeof(eid), &ast_eid_default));
 
    if (!msg) {
        return;
    }
    ast_debug(3, "%s: Sending '%s' event to app '%s'\n", session->session_id,
        event_type, app_name);
    /*
     * We don't want to use ari_websocket_send_event() here because
     * the app may be unregistered which will cause stasis_app_event_allowed
     * to return false.
     */
    session_send_or_queue(session, msg, event_type, app_name, debug_app);
    ast_json_unref(msg);
}
 
static struct ast_json *session_read(struct ari_ws_session *session)
{
    RAII_VAR(struct ast_json *, message, NULL, ast_json_unref);
 
    if (!session || !session->ast_ws_session) {
        return NULL;
    }
    if (ast_websocket_fd(session->ast_ws_session) < 0) {
        return NULL;
    }
 
    while (!message) {
        int res;
        char *payload;
        uint64_t payload_len;
        enum ast_websocket_opcode opcode;
        int fragmented;
 
        res = ast_wait_for_input(
            ast_websocket_fd(session->ast_ws_session), -1);
 
        if (res <= 0) {
            ast_log(LOG_WARNING, "WebSocket poll error: %s\n",
                strerror(errno));
            return NULL;
        }
 
        res = ast_websocket_read(session->ast_ws_session, &payload,
            &payload_len, &opcode, &fragmented);
 
        if (res != 0) {
            ast_log(LOG_WARNING, "WebSocket read error: %s\n",
                strerror(errno));
            return NULL;
        }
 
        switch (opcode) {
        case AST_WEBSOCKET_OPCODE_CLOSE:
            ast_debug(1, "WebSocket closed\n");
            return NULL;
        case AST_WEBSOCKET_OPCODE_TEXT:
            message = ast_json_load_buf(payload, payload_len, NULL);
            if (message == NULL) {
                struct ast_json *error = ast_json_pack(
                    "{s:s, s:s, s:s, s:i, s:s, s:s }",
                    "type", "RESTResponse",
                    "transaction_id", "",
                    "request_id", "",
                    "status_code", 400,
                    "reason_phrase", "Failed to parse request message JSON",
                    "uri", ""
                    );
                ari_websocket_send_event(session, session->app_name,
                    error, 0);
                ast_json_unref(error);
                ast_log(LOG_WARNING,
                    "WebSocket input failed to parse\n");
 
            }
 
            break;
        default:
            /* Ignore all other message types */
            break;
        }
    }
 
    return ast_json_ref(message);
}
 
void ari_handle_websocket(
    struct ast_tcptls_session_instance *ser, const char *uri,
    enum ast_http_method method, struct ast_variable *get_params,
    struct ast_variable *headers)
{
    struct ast_http_uri fake_urih = {
        .data = ast_ws_server,
    };
 
    ast_websocket_uri_cb(ser, &fake_urih, uri, method, get_params,
        headers);
}
 
/*!
 * \brief Callback handler for Stasis application messages.
 *
 * \internal
 *
 * \param data      Void pointer to the event session (\ref event_session).
 * \param app_name  Name of the Stasis application that dispatched the message.
 * \param message   The dispatched message.
 * \param debug_app Debug flag for the application.
 */
void ari_websocket_send_event(struct ari_ws_session *session,
    const char *app_name, struct ast_json *message, int debug_app)
{
    char *remote_addr = session->ast_ws_session ? ast_sockaddr_stringify(
            ast_websocket_remote_address(session->ast_ws_session)) : "";
    const char *msg_type, *msg_application;
    SCOPE_ENTER(4, "%s: Dispatching message from Stasis app '%s'\n", remote_addr, app_name);
 
    ast_assert(session != NULL);
 
    ao2_lock(session);
 
    msg_type = S_OR(ast_json_string_get(ast_json_object_get(message, "type")), "");
    msg_application = S_OR(
        ast_json_string_get(ast_json_object_get(message, "application")), app_name);
 
    /* If we've been replaced, remove the application from our local
       websocket_apps container */
    if (session->type == AST_WS_TYPE_INBOUND
        && strcmp(msg_type, "ApplicationReplaced") == 0 &&
        strcmp(msg_application, app_name) == 0) {
        AST_VECTOR_REMOVE_CMP_ORDERED(&session->websocket_apps,
            app_name, ast_strings_equal, ast_free_ptr);
    }
 
    /* Now, we need to determine our state to see how we will handle the message */
    if (ast_json_object_set(message, "application", ast_json_string_create(app_name))) {
        ao2_unlock(session);
        SCOPE_EXIT_LOG_RTN(LOG_WARNING,
            "%s: Failed to dispatch '%s' message from Stasis app '%s'; could not update message\n",
            remote_addr, msg_type, msg_application);
    }
 
    if (stasis_app_event_allowed(app_name, message)) {
        session_send_or_queue(session, message, msg_type,
            app_name, debug_app);
    }
 
    if (session->type == AST_WS_TYPE_CLIENT_PER_CALL
        && !ast_strlen_zero(session->channel_id)
        && ast_strings_equal(msg_type, "StasisEnd")) {
        struct ast_json *chan = ast_json_object_get(message, "channel");
        struct ast_json *id_obj = ast_json_object_get(chan, "id");
        const char *id = ast_json_string_get(id_obj);
        if (!ast_strlen_zero(id)
            && ast_strings_equal(id, session->channel_id)) {
            ast_debug(3, "%s: StasisEnd message sent for channel '%s'\n",
                remote_addr, id);
            session->stasis_end_sent = 1;
        }
    }
    ao2_unlock(session);
    SCOPE_EXIT("%s: Dispatched '%s' message from Stasis app '%s'\n",
        remote_addr, msg_type, app_name);
}
 
static void stasis_app_message_handler(void *data, const char *app_name,
    struct ast_json *message)
{
    int debug_app = stasis_app_get_debug_by_name(app_name);
    struct ari_ws_session *session = data;
 
    if (!session) {
        ast_debug(3, "Stasis app '%s' message handler called with NULL session.  OK for per_call_config websocket.\n",
            app_name);
        return;
    }
 
    ari_websocket_send_event(session, app_name, message, debug_app);
}
 
static void session_unref(struct ari_ws_session *session)
{
    if (!session) {
        return;
    }
    ast_debug(4, "%s: Unreffing ARI websocket session\n", session->session_id);
    ao2_ref(session, -1);
}
 
static void session_unregister_app_cb(char *app_name, struct ari_ws_session *session)
{
    ast_debug(3, "%s: Trying to unregister app '%s'\n",
        session->session_id, app_name);
    if (session->type == AST_WS_TYPE_CLIENT_PER_CALL_CONFIG) {
        char context_name[AST_MAX_CONTEXT + 1];
        sprintf(context_name, "%s%s", STASIS_CONTEXT_PREFIX, app_name);
        ast_debug(3, "%s: Unregistering context '%s' for app '%s'\n",
            session->session_id, context_name, app_name);
        ast_context_destroy_by_name(context_name, ARI_CONTEXT_REGISTRAR);
    } else {
        ast_debug(3, "%s: Unregistering stasis app '%s' and unsubscribing from all events.\n",
            session->session_id, app_name);
        stasis_app_unregister(app_name);
    }
 
    /*
     * We don't send ApplicationUnregistered events for outbound per-call
     * configs because there's no websocket to send them via or to
     * inbound websockets because the websocket is probably closed already.
     */
    if (!(session->type
        & (AST_WS_TYPE_CLIENT_PER_CALL_CONFIG | AST_WS_TYPE_INBOUND))) {
        session_send_app_event(session, "ApplicationUnregistered", app_name);
    }
}
 
static void session_unregister_apps(struct ari_ws_session *session)
{
    int app_count = (int)AST_VECTOR_SIZE(&session->websocket_apps);
 
    if (app_count == 0) {
        return;
    }
    ast_debug(3, "%s: Unregistering stasis apps.\n", session->session_id);
 
    AST_VECTOR_CALLBACK_VOID(&session->websocket_apps, session_unregister_app_cb,
        session);
    AST_VECTOR_RESET(&session->websocket_apps, ast_free_ptr);
 
    return;
}
 
static int session_register_apps(struct ari_ws_session *session,
    const char *_apps, int subscribe_all)
{
    char *apps = ast_strdupa(_apps);
    char *app_name;
    int app_counter = 0;
 
    ast_debug(3, "%s: Registering apps '%s'.  Subscribe all: %s\n",
        session->session_id, apps, subscribe_all ? "yes" : "no");
 
    while ((app_name = ast_strsep(&apps, ',', AST_STRSEP_STRIP))) {
 
        if (ast_strlen_zero(app_name)) {
            ast_log(LOG_WARNING, "%s: Invalid application name\n", session->session_id);
            return -1;
        }
 
        if (strlen(app_name) > ARI_MAX_APP_NAME_LEN) {
            ast_log(LOG_WARNING, "%s: Websocket app '%s' > %d characters\n",
                session->session_id, app_name, (int)ARI_MAX_APP_NAME_LEN);
            return -1;
        }
 
        if (session->type == AST_WS_TYPE_CLIENT_PER_CALL_CONFIG) {
            /*
             * Outbound per-call configs only create a dialplan context.
             * If they registered stasis apps there'd be no way for the
             * Stasis dialplan app to know that it needs to start a
             * per-call websocket connection.
             */
            char context_name[AST_MAX_CONTEXT + 1];
 
            sprintf(context_name, "%s%s", STASIS_CONTEXT_PREFIX, app_name);
            if (!ast_context_find(context_name)) {
                if (!ast_context_find_or_create(NULL, NULL, context_name,
                    ARI_CONTEXT_REGISTRAR)) {
                    ast_log(LOG_WARNING, "%s: Could not create context '%s'\n",
                        session->session_id, context_name);
                    return -1;
                } else {
                    ast_add_extension(context_name, 0, "_.", 1, NULL, NULL,
                        "Stasis", ast_strdup(app_name), ast_free_ptr,
                        ARI_CONTEXT_REGISTRAR);
                    ast_add_extension(context_name, 0, "h", 1, NULL, NULL,
                        "NoOp", NULL, NULL, ARI_CONTEXT_REGISTRAR);
                }
            } else {
                ast_debug(3, "%s: Context '%s' already exists\n", session->session_id,
                    context_name);
            }
        } else {
            int already_registered = stasis_app_is_registered(app_name);
            int res = 0;
 
            if (subscribe_all) {
                res = stasis_app_register_all(app_name, stasis_app_message_handler,
                    session);
            } else {
                res = stasis_app_register(app_name, stasis_app_message_handler,
                    session);
            }
 
            if (res != 0) {
                return -1;
            }
 
            /*
             * If there was an existing app by the same name, the register handler
             * will have sent an ApplicationReplaced event.  If it's a new app, we
             * send an ApplicationRegistered event.
             *
             * Except... There's no websocket to send it on for outbound per-call
             * configs and inbound websockets don't need them because they aready
             * know what apps they've registered for.
             */
            if (!already_registered
                && !(session->type & (AST_WS_TYPE_INBOUND | AST_WS_TYPE_CLIENT_PER_CALL_CONFIG))) {
                session_send_app_event(session, "ApplicationRegistered",
                    app_name);
            }
        }
 
        if (AST_VECTOR_ADD_SORTED(&session->websocket_apps, ast_strdup(app_name), strcmp)) {
            ast_log(LOG_WARNING, "%s: Unable to add app '%s' to apps container\n",
                session->session_id, app_name);
            return -1;
        }
 
        app_counter++;
        if (app_counter == 1) {
            ast_free(session->app_name);
            session->app_name = ast_strdup(app_name);
            if (!session->app_name) {
                ast_log(LOG_WARNING, "%s: Unable to duplicate app name\n",
                    session->session_id);
                return -1;
            }
        }
    }
 
    return 0;
}
 
/*
 * Websocket session cleanup is a bit complicated because it can be
 * in different states, it may or may not be in the registry container,
 * and stasis may be sending asynchronous events to it and some
 * stages of cleanup need to lock it.
 *
 * That's why there are 3 different cleanup functions.
 */
 
/*!
 * \internal
 * \brief Reset the ari_ws_session without destroying it.
 * It can't be reused and will be cleaned up by the caller.
 * This should only be called by session_create()
 * and session_cleanup().
 */
static void session_reset(struct ari_ws_session *session)
{
    SCOPED_AO2LOCK(lock, session);
 
    ast_debug(3, "%s: Resetting ARI websocket session\n",
        session->session_id);
 
    /* Clean up the websocket_apps container */
    if (AST_VECTOR_SIZE(&session->websocket_apps) > 0) {
        session_unregister_apps(session);
    }
    AST_VECTOR_RESET(&session->websocket_apps, ast_free_ptr);
    AST_VECTOR_FREE(&session->websocket_apps);
 
    AST_VECTOR_RESET(&session->message_queue, ast_json_unref);
    AST_VECTOR_FREE(&session->message_queue);
}
 
/*!
 * \internal
 * \brief RAII_VAR and container ari_ws_session cleanup function.
 * This unlinks the ari_ws_session from the registry and cleans up the
 * decrements the reference count.
 */
static void session_cleanup(void *obj)
{
    struct ari_ws_session *session = obj;
    enum ast_websocket_type wstype;
 
    if (!session) {
        return;
    }
 
    /*
     * We need to save the websocket type because client-per-call websockets
     * will get destroyed when they're unlinked from the session_registry
     * so we won't be able to test it afterwards.
     */
    wstype = session->type;
 
    ast_debug(3, "%s: Cleaning up ARI %s websocket session. Refcount: %d\n",
        session->session_id, ast_websocket_type_to_str(wstype), (int)ao2_ref(session, 0));
 
    session_reset(session);
 
    if (session_registry) {
        ast_debug(3, "%s: Unlinking %s websocket session from registry Refcount: %d\n",
            session->session_id, ast_websocket_type_to_str(wstype), (int)ao2_ref(session, 0));
        ao2_unlink(session_registry, session);
    }
 
    /*
     * If this is a per-call config then its only reference
     * was held by the registry container so we don't need
     * to unref it here.
     */
    if (wstype != AST_WS_TYPE_CLIENT_PER_CALL_CONFIG) {
        session_unref(session);
    }
}
 
/*!
 * \internal
 * \brief The ao2 destructor.
 * This cleans up the reference to the parent ast_websocket and the
 * outbound connection websocket if any.
 */
static void session_dtor(void *obj)
{
    struct ari_ws_session *session = obj;
 
    ast_debug(3, "%s: Destroying ARI websocket session\n",
        session->session_id);
 
    ast_free(session->app_name);
    ast_free(session->remote_addr);
    ast_free(session->channel_id);
    ast_free(session->channel_name);
    ao2_cleanup(session->owc);
    session->owc = NULL;
    if (!session->ast_ws_session) {
        return;
    }
    ast_websocket_unref(session->ast_ws_session);
    session->ast_ws_session = NULL;
}
 
#define handle_create_error(ser, code, msg, reason) \
({ \
    if (ser) { \
        ast_http_error(ser, code, msg, reason); \
    } \
    ast_log(LOG_WARNING, "Failed to create ARI websocket session: %d %s %s\n", \
        code, msg, reason); \
})
 
static struct ari_ws_session *session_create(
    struct ast_tcptls_session_instance *ser,
    const char *apps,
    int subscribe_all,
    const char *session_id,
    struct ari_conf_outbound_websocket *ows,
    enum ast_websocket_type ws_type)
{
    RAII_VAR(struct ari_ws_session *, session, NULL, ao2_cleanup);
    size_t size;
 
    ast_debug(3, "%s: Creating ARI websocket session for apps '%s'\n",
         session_id, apps);
 
    size = sizeof(*session) + strlen(session_id) + 1;
 
    session = ao2_alloc(size, session_dtor);
    if (!session) {
        return NULL;
    }
 
    session->type = ws_type;
    session->subscribe_all = subscribe_all;
 
    strcpy(session->session_id, session_id); /* Safe */
 
    /* Instantiate the hash table for Stasis apps */
    if (AST_VECTOR_INIT(&session->websocket_apps, APPS_INIT_SIZE)) {
        handle_create_error(ser, 500, "Internal Server Error",
            "Allocation failed");
        return NULL;
    }
 
    /* Instantiate the message queue */
    if (AST_VECTOR_INIT(&session->message_queue, MESSAGES_INIT_SIZE)) {
        handle_create_error(ser, 500, "Internal Server Error",
            "Allocation failed");
        AST_VECTOR_FREE(&session->websocket_apps);
        return NULL;
    }
 
    session->validator = ari_validate_message_fn;
 
    if (ows) {
        session->owc = ao2_bump(ows);
    }
 
    if (session_register_apps(session, apps, subscribe_all) < 0) {
        handle_create_error(ser, 500, "Internal Server Error",
            "Stasis app registration failed");
        session_reset(session);
        return NULL;
    }
 
    if (!ao2_link(session_registry, session)) {
        handle_create_error(ser, 500, "Internal Server Error",
            "Allocation failed");
        session_reset(session);
        return NULL;
    }
 
    return ao2_bump(session);
}
 
/*!
 * \internal
 * \brief Updates the websocket session.
 *
 * \details If the value of the \c ws_session is not \c NULL and there are messages in the
 *          event session's \c message_queue, the messages are dispatched and removed from
 *          the queue.
 *
 * \param ari_ws_session  The ARI websocket session
 * \param ast_ws_session  The Asterisk websocket session
 */
static int session_update(struct ari_ws_session *ari_ws_session,
    struct ast_websocket *ast_ws_session, int send_registered_events)
{
    RAII_VAR(struct ari_conf_general *, general, ari_conf_get_general(), ao2_cleanup);
    int i;
 
    if (ast_ws_session == NULL) {
        return -1;
    }
 
    if (!general) {
        return -1;
    }
 
    ari_ws_session->remote_addr = ast_strdup(ast_sockaddr_stringify(
        ast_websocket_remote_address(ast_ws_session)));
    if (!ari_ws_session->remote_addr) {
        ast_log(LOG_ERROR, "Failed to copy remote address\n");
        return -1;
    }
 
    if (ast_websocket_set_nonblock(ast_ws_session) != 0) {
        ast_log(LOG_ERROR,
            "ARI web socket failed to set nonblock; closing: %s\n",
            strerror(errno));
        return -1;
    }
 
    if (ast_websocket_set_timeout(ast_ws_session, general->write_timeout)) {
        ast_log(LOG_WARNING, "Failed to set write timeout %d on ARI web socket\n",
            general->write_timeout);
    }
 
    ast_websocket_ref(ast_ws_session);
    ari_ws_session->ast_ws_session = ast_ws_session;
    ao2_lock(ari_ws_session);
    for (i = 0; i < AST_VECTOR_SIZE(&ari_ws_session->message_queue); i++) {
        struct ast_json *msg = AST_VECTOR_GET(&ari_ws_session->message_queue, i);
        session_write(ari_ws_session, msg);
        ast_json_unref(msg);
    }
 
    AST_VECTOR_RESET(&ari_ws_session->message_queue, AST_VECTOR_ELEM_CLEANUP_NOOP);
    ao2_unlock(ari_ws_session);
 
    if (send_registered_events) {
        int i;
        char *app;
 
        for (i = 0; i < AST_VECTOR_SIZE(&ari_ws_session->websocket_apps); i++) {
            app = AST_VECTOR_GET(&ari_ws_session->websocket_apps, i);
            session_send_app_event(ari_ws_session,
                "ApplicationRegistered", app);
        }
    }
 
    return 0;
}
 
/*!
 * \internal
 * \brief This function gets called for incoming websocket connections
 * before the upgrade process is completed.
 *
 * The point is to be able to report early errors via HTTP rather
 * than letting res_http_websocket create an ast_websocket session
 * then immediately close it if there's an error.
 */
static int websocket_attempted_cb(struct ast_tcptls_session_instance *ser,
    struct ast_variable *get_params, struct ast_variable *headers,
    const char *session_id)
{
    const char *subscribe_all = NULL;
    const char *apps = NULL;
    struct ari_ws_session *session = NULL;
 
    apps = ast_variable_find_in_list(get_params, "app");
    if (ast_strlen_zero(apps)) {
        handle_create_error(ser, 400, "Bad Request",
            "HTTP request is missing param: [app]");
        return -1;
    }
 
    subscribe_all = ast_variable_find_in_list(get_params, "subscribeAll");
 
    session = session_create(ser, apps, ast_true(subscribe_all),
        session_id, NULL, AST_WS_TYPE_INBOUND);
    if (!session) {
        handle_create_error(ser, 500, "Server Error",
            "Failed to create ARI websocket session");
        return -1;
    }
    /* It's in the session registry now so we can release our reference */
    session_unref(session);
 
    return 0;
}
 
/*!
 * \internal
 * \brief This function gets called for incoming websocket connections
 * after the upgrade process is completed.
 */
static void websocket_established_cb(struct ast_websocket *ast_ws_session,
    struct ast_variable *get_params, struct ast_variable *upgrade_headers)
{
    /*
     * ast_ws_session is passed in with it's refcount bumped so
     * we need to unref it when we're done.  The refcount will
     * be bumped again when we add it to the ari_ws_session.
     */
    RAII_VAR(struct ast_websocket *, s, ast_ws_session, ast_websocket_unref);
    RAII_VAR(struct ari_ws_session *, ari_ws_session, NULL, session_cleanup);
    struct ast_json *msg;
    struct ast_variable *v;
    char *remote_addr = ast_sockaddr_stringify(
        ast_websocket_remote_address(ast_ws_session));
    const char *session_id = ast_websocket_session_id(ast_ws_session);
 
    SCOPE_ENTER(2, "%s: WebSocket established\n", remote_addr);
 
    if (TRACE_ATLEAST(2)) {
        ast_trace(2, "%s: Websocket Upgrade Headers:\n", remote_addr);
        for (v = upgrade_headers; v; v = v->next) {
            ast_trace(3, "--> %s: %s\n", v->name, v->value);
        }
    }
 
    /*
     * Find the ari_ws_session that was created by websocket_attempted_cb
     * and update its ast_websocket.
     */
    ari_ws_session = ao2_find(session_registry, session_id, OBJ_SEARCH_KEY);
    if (!ari_ws_session) {
         SCOPE_EXIT_LOG_RTN(LOG_ERROR,
            "%s: Failed to locate an event session for the websocket session %s\n",
            remote_addr, session_id);
    }
 
    /*
     * Since this is a new inbound websocket session,
     * session_register_apps() will have already sent "ApplicationRegistered"
     * events for the apps. We don't want to do it again.
     */
    session_update(ari_ws_session, ast_ws_session, 0);
 
    ari_ws_session->connected = 1;
    ast_trace(-1, "%s: Waiting for messages\n", remote_addr);
    while ((msg = session_read(ari_ws_session))) {
        ari_websocket_process_request(ari_ws_session, remote_addr,
            upgrade_headers, ari_ws_session->app_name, msg);
        ast_json_unref(msg);
    }
    ast_websocket_close(ast_ws_session, AST_WEBSOCKET_STATUS_GOING_AWAY);
    ari_ws_session->connected = 0;
 
    SCOPE_EXIT("%s: Websocket closed\n", remote_addr);
}
 
static int session_shutdown_cb(void *obj, void *arg, int flags)
{
    struct ari_ws_session *session = obj;
 
    /* Per-call configs have no actual websocket */
    if (session->type == AST_WS_TYPE_CLIENT_PER_CALL_CONFIG) {
        ast_log(LOG_NOTICE, "%s: Shutting down %s ARI websocket session\n",
            session->session_id,
            ari_websocket_type_to_str(session->type));
        session_cleanup(session);
        return 0;
    }
    if (session->type == AST_WS_TYPE_INBOUND) {
        ast_log(LOG_NOTICE, "%s: Shutting down inbound ARI websocket session from %s\n",
            session->session_id, session->remote_addr);
    } else {
        ast_log(LOG_NOTICE, "%s: Shutting down %s ARI websocket session to %s\n",
            session->session_id,
            ari_websocket_type_to_str(session->type),
            session->remote_addr);
    }
 
    /*
     * We need to ensure the session is kept around after the cleanup
     * so we can close the websocket.
     */
    ao2_bump(session);
    session->closing = 1;
    session_cleanup(session);
    if (session->ast_ws_session) {
        ast_debug(3, "%s: Closing websocket\n", session->session_id);
        ast_websocket_close(session->ast_ws_session, 1000);
    } else if (session->thread) {
        ast_debug(3, "%s: Cancelling handler thread\n", session->session_id);
        pthread_cancel(session->thread);
    }
 
    return 0;
}
 
 
struct ari_ws_session * ari_websocket_get_session(const char *session_id)
{
    return ao2_find(session_registry, session_id, OBJ_SEARCH_KEY);
}
 
static struct ari_ws_session *session_find_by_app(const char *app_name,
    unsigned int ws_type)
{
    struct ari_ws_session *session = NULL;
    struct ao2_iterator i;
 
    if (ast_strlen_zero(app_name)) {
        return NULL;
    }
 
    i = ao2_iterator_init(session_registry, 0);
    while ((session = ao2_iterator_next(&i))) {
        char *app = NULL;
        if (!(session->type & ws_type)) {
            session_unref(session);
            continue;
        }
 
        app = AST_VECTOR_GET_CMP(&session->websocket_apps,
            app_name, ast_strings_equal);
        if (app) {
            break;
        }
        session_unref(session);
    }
    ao2_iterator_destroy(&i);
    return session;
}
 
/*!
 * \internal
 * \brief Connection and request handler thread for outbound websockets.
 *
 * This thread handles the connection and reconnection logic for outbound
 * websockets.  Once connected, it waits for incoming REST over Websocket
 * requests and dispatches them to ari_websocket_process_request()).
 */
static void *outbound_session_handler_thread(void *obj)
{
    struct ari_ws_session *session = obj;
    int already_sent_registers = 1;
 
    /*
     * We use pthread_cleanup_push because RAII destructors don't run
     * if we cancel the thread.
     */
    pthread_cleanup_push(session_cleanup, obj);
 
    ast_debug(3, "%s: Starting outbound websocket thread RC: %d\n",
        session->session_id, (int)ao2_ref(session, 0));
    session->thread = pthread_self();
    session->connected = 0;
 
    while(1) {
        RAII_VAR(struct ast_websocket *, astws, NULL, ast_websocket_unref);
        RAII_VAR(struct ast_variable *, upgrade_headers, NULL, ast_variables_destroy);
        enum ast_websocket_result result;
        struct ast_json *msg;
 
        ast_debug(3, "%s: Attempting to connect to %s\n", session->session_id,
            session->owc->websocket_client->uri);
 
        astws = ast_websocket_client_connect(session->owc->websocket_client,
            NULL, session->session_id, &result);
        if (!astws || result != WS_OK) {
            if (session->type == AST_WS_TYPE_CLIENT_PER_CALL) {
                struct stasis_app_control *control =
                    stasis_app_control_find_by_channel_id(session->channel_id);
                if (control) {
                    ast_debug(3, "%s: Connection failed.  Returning to dialplan.\n",
                        session->session_id);
                    stasis_app_control_mark_failed(control);
                    stasis_app_control_continue(control, NULL, NULL, -1);
                    ao2_cleanup(control);
                } else {
                    ast_debug(3, "%s: Connection failed.  No control object found.\n",
                        session->session_id);
                }
 
                break;
            }
 
            if (session->closing) {
                ast_debug(3, "%s: Websocket closing RC: %d\n",
                    session->session_id, (int)ao2_ref(session, 0));
                break;
            }
 
            usleep(session->owc->websocket_client->reconnect_interval * 1000);
            continue;
        }
        ast_log(LOG_NOTICE, "%s: Outbound websocket connected to %s\n",
            session->type == AST_WS_TYPE_CLIENT_PERSISTENT ? session->session_id : session->channel_name,
                session->owc->websocket_client->uri);
 
        /*
         * We only want to send "ApplicationRegistered" events in the
         * case of a reconnect.  The initial connection will have already sent
         * the events when outbound_register_apps() was called.
         *
         * Note: session_update() bumps astws.
         */
        session_update(session, astws, !already_sent_registers);
        already_sent_registers = 0;
 
        /*
         * This is the Authorization header that would normally be taken
         * from the incoming HTTP request that is being upgraded to a websocket.
         * Since this is an outbound websocket, we have to create it ourselves.
         *
         * This is NOT the same as the Authorization header that is used for
         * authentication with the remote websocket server.
         */
        upgrade_headers = ast_http_create_basic_auth_header(
            session->owc->local_ari_user, session->owc->local_ari_password);
        if (!upgrade_headers) {
            ast_log(LOG_WARNING, "%s: Failed to create upgrade header\n", session->session_id);
            session->thread = 0;
            session->connected = 0;
            ast_websocket_close(astws, 1000);
            /* Clean up the reference held by session_update() */
            ast_websocket_unref(astws);
            session->ast_ws_session = NULL;
            break;
        }
 
        session->connected = 1;
        ast_debug(3, "%s: Websocket connected\n", session->session_id);
        ast_debug(3, "%s: Waiting for messages RC: %d\n",
            session->session_id, (int)ao2_ref(session, 0));
 
        /*
         * The websocket is connected.  Now we need to wait for messages
         * from the server.
         */
        while ((msg = session_read(session))) {
            ari_websocket_process_request(session, session->remote_addr,
                upgrade_headers, session->app_name, msg);
            ast_json_unref(msg);
        }
 
        session->connected = 0;
        ast_websocket_close(session->ast_ws_session, AST_WEBSOCKET_STATUS_GOING_AWAY);
        /* Clean up the reference held by session_update() */
        ast_websocket_unref(session->ast_ws_session);
        session->ast_ws_session = NULL;
        if (session->closing) {
            ast_debug(3, "%s: Websocket closing RC: %d\n",
                session->session_id, (int)ao2_ref(session, 0));
            break;
        }
 
        ast_log(LOG_WARNING, "%s: Websocket disconnected.  Reconnecting\n",
            session->session_id);
    }
 
    ast_debug(3, "%s: Stopping outbound websocket thread RC: %d\n",
        session->session_id, (int)ao2_ref(session, 0));
    session->thread = 0;
 
    pthread_cleanup_pop(1);
 
    return NULL;
}
 
enum session_apply_result {
    SESSION_APPLY_NO_CHANGE,
    SESSION_APPLY_OK,
    SESSION_APPLY_RECONNECT_REQUIRED,
    SESSION_APPLY_FAILED,
};
 
static enum session_apply_result outbound_session_apply_config(
    struct ari_ws_session *session,
    struct ari_conf_outbound_websocket *new_owc)
{
    enum session_apply_result apply_result;
    enum ari_conf_owc_fields what_changed;
    const char *new_owc_id = ast_sorcery_object_get_id(new_owc);
 
    what_changed = ari_conf_owc_detect_changes(session->owc, new_owc);
 
    if (what_changed == ARI_OWC_FIELD_NONE) {
        ast_debug(2, "%s: No changes detected\n", new_owc_id);
        return SESSION_APPLY_NO_CHANGE;
    }
    ast_debug(2, "%s: Config change detected.  Checking details\n", new_owc_id);
 
    if (what_changed & ARI_OWC_NEEDS_REREGISTER) {
        ast_debug(2, "%s: Re-registering apps\n", new_owc_id);
 
        if (!(what_changed & ARI_OWC_FIELD_SUBSCRIBE_ALL)) {
            /*
             * If subscribe_all didn't change, we don't have to
             * unregister apps that are already registered and
             * also in the new config.  We'll remove them from
             * the session->websocket_apps container so that
             * session_unregister_apps will only clean up
             * the ones that are going away. session_register_apps
             * will add them back in again and cause ApplicationReplaced
             * messages to be sent.
             *
             * If subscribe_all did change, we have no choice but to
             * unregister all apps and register all the ones in
             * the new config even if they already existed.
             */
            int i = 0;
            char *app;
 
            while(i < (int) AST_VECTOR_SIZE(&session->websocket_apps)) {
                app = AST_VECTOR_GET(&session->websocket_apps, i);
                if (ast_in_delimited_string(app, new_owc->apps, ',')) {
                    AST_VECTOR_REMOVE_ORDERED(&session->websocket_apps, i);
                    ast_debug(3, "%s: Unlinked app '%s' to keep it from being unregistered\n",
                        new_owc_id, app);
                    ast_free(app);
                } else {
                    i++;
                }
            }
        }
 
        session_unregister_apps(session);
 
        /*
         * Register the new apps.  This will also replace any
         * existing apps that are in the new config sending
         * ApplicationRegistered or ApplicationReplaced events
         * as necessary.
         */
        if (session_register_apps(session, new_owc->apps,
                new_owc->subscribe_all) < 0) {
            ast_log(LOG_WARNING, "%s: Failed to register apps '%s'\n",
                new_owc_id, new_owc->apps);
            /* Roll back. */
            session_unregister_apps(session);
            /* Re-register the original apps. */
            if (session_register_apps(session, session->owc->apps,
                        session->owc->subscribe_all) < 0) {
                ast_log(LOG_WARNING, "%s: Failed to re-register apps '%s'\n",
                    new_owc_id, session->owc->apps);
            }
            return SESSION_APPLY_FAILED;
        }
    }
    /*
     * We need to update the session with the new config
     * but it has to be done after re-registering apps and
     * before we reconnect.
     */
    ao2_replace(session->owc, new_owc);
    session->type = new_owc->websocket_client->connection_type;
    session->subscribe_all = new_owc->subscribe_all;
 
    apply_result = SESSION_APPLY_OK;
 
    if (what_changed & ARI_OWC_NEEDS_RECONNECT) {
        ast_debug(2, "%s: Reconnect required\n", new_owc_id);
        apply_result = SESSION_APPLY_RECONNECT_REQUIRED;
        if (session->ast_ws_session) {
            ast_debug(2, "%s: Closing websocket\n", new_owc_id);
            ast_websocket_close(session->ast_ws_session, 1000);
        }
    }
 
    return apply_result;
}
 
/*
 * This is the fail-safe timeout for the per-call websocket
 * connection.  To prevent a cleanup race condition, we wait
 * 3 times the timeout the thread will use to connect to the
 * websocket server.  This way we're sure the thread will be
 * done before we do final cleanup.  This timeout is only used
 * if the thread is cancelled somehow and can't indicate
 * whether it actually connected or not.
 */
#define PER_CALL_FAIL_SAFE_TIMEOUT(owc) \
    (int64_t)((owc->websocket_client->connect_timeout + owc->websocket_client->reconnect_interval) \
    * (owc->websocket_client->reconnect_attempts + 3))
 
/*!
 * \brief This function gets called by app_stasis when a call arrives
 * but a Stasis application isn't already registered.  We check to see
 * if a per-call config exists for the application and if so, we create a
 * per-call websocket connection and return a unique app id which app_stasis
 * can use to call stasis_app_exec() with.
 */
char *ast_ari_create_per_call_websocket(const char *app_name,
    struct ast_channel *chan)
{
    RAII_VAR(struct ari_ws_session *, session, NULL, session_unref);
    RAII_VAR(struct ari_conf_outbound_websocket *, owc, NULL, ao2_cleanup);
    RAII_VAR(char *, session_id, NULL, ast_free);
    RAII_VAR(char *, app_id, NULL, ast_free);
    enum ari_conf_owc_fields invalid_fields;
    const char *owc_id = NULL;
    char *app_id_rtn = NULL;
    struct timeval tv_start;
    int res = 0;
 
    owc = ari_conf_get_owc_for_app(app_name, AST_WS_TYPE_CLIENT_PER_CALL_CONFIG);
    if (!owc) {
        ast_log(LOG_WARNING, "%s: Failed to find outbound websocket per-call config for app '%s'\n",
            ast_channel_name(chan), app_name);
        return NULL;
    }
    owc_id = ast_sorcery_object_get_id(owc);
    invalid_fields = ari_conf_owc_get_invalid_fields(owc_id);
 
    if (invalid_fields) {
        ast_log(LOG_WARNING, "%s: Unable to create per-call websocket.  Outbound websocket config is invalid\n",
            owc_id);
        return NULL;
    }
 
    res = ast_asprintf(&session_id, "%s:%s", owc_id, ast_channel_name(chan));
    if (res < 0) {
        return NULL;
    }
    res = ast_asprintf(&app_id, "%s:%s", app_name, ast_channel_name(chan));
    if (res < 0) {
        ast_free(app_id);
        return NULL;
    }
 
    session = session_create(NULL, app_id, owc->subscribe_all,
        session_id, owc, AST_WS_TYPE_CLIENT_PER_CALL);
    if (!session) {
        ast_log(LOG_WARNING, "%s: Failed to create websocket session\n", session_id);
        return NULL;
    }
 
    session->channel_id = ast_strdup(ast_channel_uniqueid(chan));
    session->channel_name = ast_strdup(ast_channel_name(chan));
 
    /*
     * We have to bump the session reference count here because
     * we need to check that the session is connected before we return.
     * If it didn't connect, then the thread will have cleaned up the
     * session while we're in the loop checking for the connection
     * which will result in a SEGV or FRACK.
     * RAII will clean up this bump.
     */
    ao2_bump(session);
    ast_debug(2, "%s: Starting thread RC: %d\n", session->session_id,
        (int)ao2_ref(session, 0));
 
    if (ast_pthread_create_detached_background(&session->thread, NULL,
        outbound_session_handler_thread, session)) {
        session_cleanup(session);
        ast_log(LOG_WARNING, "%s: Failed to create thread.\n", session->session_id);
        return NULL;
    }
 
    /*
     * We need to make sure the session connected and is processing
     * requests before we return but we don't want to block forever
     * in case the thread never starts or gets cancelled so we have
     * a fail-safe timeout.
     */
    tv_start = ast_tvnow();
    while (session->thread > 0 && !session->connected) {
        struct timeval tv_now = ast_tvnow();
        if (ast_tvdiff_ms(tv_now, tv_start) > PER_CALL_FAIL_SAFE_TIMEOUT(owc)) {
            break;
        }
        /* Sleep for 500ms before checking again. */
        usleep(500 * 1000);
    }
 
    if (session->thread <= 0 || !session->connected) {
        ast_log(LOG_WARNING, "%s: Failed to create per call websocket thread\n",
            session_id);
        return NULL;
    }
 
    ast_debug(3, "%s: Created per call websocket for app '%s'\n",
        session_id, app_id);
 
    /*
     * We now need to prevent RAII from freeing the app_id.
     */
    app_id_rtn = app_id;
    app_id = NULL;
    return app_id_rtn;
}
 
#define STASIS_END_MAX_WAIT_MS 5000
#define STASIS_END_POST_WAIT_US (3000 * 1000)
 
/*
 * This thread is used to close the websocket after the StasisEnd
 * event has been sent and control has been returned to the dialplan.
 * We wait a few seconds to allow additional events to be sent
 * like ChannelVarset and ChannelDestroyed.
 */
static void *outbound_session_pc_close_thread(void *data)
{
    /*
     * We're using RAII because we want to show a debug message
     * after we run ast_websocket_close().
     */
    RAII_VAR(struct ari_ws_session *, session, data, session_unref);
 
    /*
     * We're going to wait 3 seconds to allow stasis to send additional
     * events like ChannelVarset and ChannelDestroyed after the StasisEnd.
     */
    ast_debug(3, "%s: Waiting for %dms before closing websocket RC: %d\n",
        session->session_id, (int)(STASIS_END_POST_WAIT_US / 1000),
        (int)ao2_ref(session, 0));
    usleep(STASIS_END_POST_WAIT_US);
    session->closing = 1;
    if (session->ast_ws_session) {
        ast_websocket_close(session->ast_ws_session, 1000);
    }
    ast_debug(3, "%s: Websocket closed RC: %d\n", session->session_id,
        (int)ao2_ref(session, 0));
    return NULL;
}
 
/*!
 * \brief This function is called by the app_stasis dialplan app
 * to close a per-call websocket after stasis_app_exec() returns.
 */
void ast_ari_close_per_call_websocket(char *app_name)
{
    struct ari_ws_session *session = NULL;
    pthread_t thread;
    struct timeval tv_start;
 
    session = session_find_by_app(app_name, AST_WS_TYPE_CLIENT_PER_CALL);
    if (!session) {
        ast_debug(3, "%s: Per call websocket not found\n", app_name);
        ast_free(app_name);
        return;
    }
    ast_free(app_name);
 
    /*
     * When stasis_app_exec() returns, the StasisEnd event for the
     * channel has been queued but since actually sending it is done
     * in a separate thread, it probably won't have been sent yet.
     * We need to wait for it to go out on the wire before we close the
     * websocket.  ari_websocket_send_event will set a flag on the session
     * when a StasisEnd event is sent for the channel that originally
     * triggered the connection.  We'll wait for that but we don't want
     * to wait forever so there's a fail-safe timeout in case a thread
     * got cancelled or we missed the StasisEnd event somehow.
     */
    ast_debug(3, "%s: Waiting for StasisEnd event to be sent RC: %d\n",
        session->session_id, (int)ao2_ref(session, 0));
 
    tv_start = ast_tvnow();
    while (session->thread > 0 && !session->stasis_end_sent) {
        struct timeval tv_now = ast_tvnow();
        int64_t diff = ast_tvdiff_ms(tv_now, tv_start);
        ast_debug(3, "%s: Waiting for StasisEnd event %lu %d %ld\n",
            session->session_id, (unsigned long)session->thread,
            session->stasis_end_sent, diff);
        if (diff > STASIS_END_MAX_WAIT_MS) {
            break;
        }
        /* Sleep for 500ms before checking again. */
        usleep(500 * 1000);
    }
    ast_debug(3, "%s: StasisEnd event sent.  Scheduling websocket close. RC: %d\n",
        session->session_id, (int)ao2_ref(session, 0));
 
    /*
     * We can continue to send events like ChannelVarset and ChannelDestroyed
     * to the websocket after the StasisEnd event but those events won't be
     * generated until after the Stasis() dialplan app returns.  We don't want
     * to hold up the dialplan while we wait so we'll create a thread that waits
     * a few seconds more before closing the websocket.
     *
     * We transferring ownership of the session to the thread.
     */
    if (ast_pthread_create_detached_background(&thread, NULL,
        outbound_session_pc_close_thread, session)) {
        ast_log(LOG_WARNING, "%s: Failed to create websocket close thread\n",
            session->session_id);
        session_unref(session);
    }
    ast_debug(3, "%s: Scheduled websocket close RC: %d\n",
        session->session_id, (int)ao2_ref(session, 0));
 
    return;
}
 
struct ao2_container* ari_websocket_get_sessions(void)
{
    return ao2_bump(session_registry);
}
 
static int outbound_session_create(void *obj, void *args, int flags)
{
    struct ari_conf_outbound_websocket *owc = obj;
    const char *owc_id = ast_sorcery_object_get_id(owc);
    struct ari_ws_session *session = NULL;
    enum session_apply_result apply_result;
    enum ari_conf_owc_fields invalid_fields = ari_conf_owc_get_invalid_fields(owc_id);
 
    session = ari_websocket_get_session(owc_id);
    if (session) {
        ast_debug(2, "%s: Found existing connection\n", owc_id);
        if (invalid_fields) {
            session_unref(session);
            ast_log(LOG_WARNING,
                "%s: Unable to update websocket session. Outbound websocket config is invalid\n",
                owc_id);
            return 0;
        }
 
        ao2_lock(session);
        apply_result = outbound_session_apply_config(session, owc);
        ao2_unlock(session);
        session_unref(session);
        if (apply_result == SESSION_APPLY_FAILED) {
            ast_log(LOG_WARNING,
                "%s: Failed to apply new configuration. Existing connection preserved.\n",
                owc_id);
        }
        return 0;
    }
 
    if (invalid_fields) {
        ast_log(LOG_WARNING,
            "%s: Unable to create websocket session. Outbound websocket config is invalid\n",
            owc_id);
        return 0;
    }
 
    session = session_create(NULL, owc->apps, owc->subscribe_all, owc_id,
        owc, owc->websocket_client->connection_type);
    if (!session) {
        ast_log(LOG_WARNING, "%s: Failed to create websocket session\n", owc_id);
        return 0;
    }
 
    if (owc->websocket_client->connection_type == AST_WS_TYPE_CLIENT_PER_CALL_CONFIG) {
        /* There's no thread to transfer the reference to */
        session_unref(session);
        return 0;
    }
 
    ast_debug(2, "%s: Starting thread RC: %d\n", session->session_id,
        (int)ao2_ref(session, 0));
    /* We're transferring the session reference to the thread. */
    if (ast_pthread_create_detached_background(&session->thread, NULL,
        outbound_session_handler_thread, session)) {
        session_cleanup(session);
        ast_log(LOG_WARNING, "%s: Failed to create thread.\n", session->session_id);
        return 0;
    }
    ast_debug(2, "%s: launched thread\n", session->session_id);
 
    return 0;
}
 
static void outbound_sessions_load(const char *name)
{
    RAII_VAR(struct ao2_container *, owcs, ari_conf_get_owcs(), ao2_cleanup);
    struct ao2_iterator i;
    struct ari_ws_session *session;
 
    ast_debug(2, "Reloading ARI websockets\n");
 
    ao2_callback(owcs, OBJ_NODATA, outbound_session_create, NULL);
 
    i = ao2_iterator_init(session_registry, 0);
    while ((session = ao2_iterator_next(&i))) {
        int cleanup = 1;
        if (session->owc
            && (session->type &
            (AST_WS_TYPE_CLIENT_PERSISTENT | AST_WS_TYPE_CLIENT_PER_CALL_CONFIG))) {
            struct ari_conf_outbound_websocket *ows =
                ari_conf_get_owc(session->session_id);
            if (!ows) {
                ast_debug(3, "Cleaning up outbound websocket %s\n",
                    session->session_id);
                session->closing = 1;
                session_cleanup(session);
                if (session->ast_ws_session) {
                    ast_debug(3, "%s: Closing websocket\n", session->session_id);
                    ast_websocket_close(session->ast_ws_session, 1000);
                } else if (session->thread) {
                    ast_debug(3, "%s: Cancelling handler thread\n", session->session_id);
                    pthread_cancel(session->thread);
                }
 
                if (session->type == AST_WS_TYPE_CLIENT_PERSISTENT) {
                    /*
                     * If persistent, session_cleanup will cleanup
                     * this reference so we don't want to double clean it up.
                     * session_cleanup doesn't cleanup the reference
                     * for per-call configs so we need to do that ourselves.
                     */
                    cleanup = 0;
                }
            }
            ao2_cleanup(ows);
        }
        /* We don't want to double cleanup if its been closed. */
        if (cleanup) {
            ao2_cleanup(session);
        }
    }
    ao2_iterator_destroy(&i);
 
    return;
}
 
int ari_outbound_websocket_start(struct ari_conf_outbound_websocket *owc)
{
    if (owc) {
        return outbound_session_create(owc, NULL, 0);
    }
    return -1;
}
 
void ari_websocket_shutdown(struct ari_ws_session *session)
{
    if (session) {
        session_shutdown_cb(session, NULL, 0);
    }
}
 
void ari_websocket_shutdown_all(void)
{
    if (session_registry) {
        ao2_callback(session_registry, OBJ_MULTIPLE | OBJ_NODATA,
            session_shutdown_cb, NULL);
    }
}
 
static void session_registry_dtor(void)
{
    if (session_registry) {
        ao2_callback(session_registry, OBJ_MULTIPLE | OBJ_NODATA,
            session_shutdown_cb, NULL);
        ao2_cleanup(session_registry);
        session_registry = NULL;
    }
}
 
static struct ast_sorcery_observer observer_callbacks = {
    .loaded = outbound_sessions_load,
};
 
int ari_websocket_unload_module(void)
{
    ari_sorcery_observer_remove("outbound_websocket", &observer_callbacks);
    session_registry_dtor();
    ao2_cleanup(ast_ws_server);
    ast_ws_server = NULL;
    return 0;
}
 
AO2_STRING_FIELD_CMP_FN(ari_ws_session, session_id)
AO2_STRING_FIELD_SORT_FN(ari_ws_session, session_id)
 
int ari_websocket_load_module(int is_enabled)
{
    int res = 0;
    struct ast_websocket_protocol *protocol;
 
    ast_debug(2, "Initializing ARI websockets.  Enabled: %s\n", is_enabled ? "yes" : "no");
 
    session_registry = ao2_container_alloc_rbtree(AO2_ALLOC_OPT_LOCK_MUTEX,
        AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE,
        ari_ws_session_sort_fn, ari_ws_session_cmp_fn);
    if (!session_registry) {
        ast_log(LOG_WARNING,
                "Failed to allocate the local registry for websocket applications\n");
        return AST_MODULE_LOAD_DECLINE;
    }
 
    res = ari_sorcery_observer_add("outbound_websocket", &observer_callbacks);
    if (res < 0) {
        ast_log(LOG_WARNING, "Failed to register ARI websocket observer\n");
        ari_websocket_unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    /*
     * The global "enabled" flag only controls whether the REST and
     * inbound websockets are enabled.  The outbound websocket
     * configs are always enabled.
    if (!is_enabled) {
        return AST_MODULE_LOAD_SUCCESS;
    }
     */
 
    ast_ws_server = ast_websocket_server_create();
    if (!ast_ws_server) {
        ari_websocket_unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    protocol = ast_websocket_sub_protocol_alloc("ari");
    if (!protocol) {
        ari_websocket_unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
    protocol->session_attempted = websocket_attempted_cb;
    protocol->session_established = websocket_established_cb;
    res = ast_websocket_server_add_protocol2(ast_ws_server, protocol);
 
    return res == 0 ? AST_MODULE_LOAD_SUCCESS : AST_MODULE_LOAD_DECLINE;
}