presencestate.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2011-2012, Digium, Inc.
 *
 * David Vossel <dvossel@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.
 */
 
/*! \file
 *
 * \brief Presence state management
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
/*** DOCUMENTATION
    <managerEvent language="en_US" name="PresenceStateChange">
        <managerEventInstance class="EVENT_FLAG_CALL">
            <synopsis>Raised when a presence state changes</synopsis>
            <syntax>
                <parameter name="Presentity">
                    <para>The entity whose presence state has changed</para>
                </parameter>
                <parameter name="Status">
                    <para>The new status of the presentity</para>
                </parameter>
                <parameter name="Subtype">
                    <para>The new subtype of the presentity</para>
                </parameter>
                <parameter name="Message">
                    <para>The new message of the presentity</para>
                </parameter>
            </syntax>
            <description>
                <para>This differs from the <literal>PresenceStatus</literal>
                event because this event is raised for all presence state changes,
                not only for changes that affect dialplan hints.</para>
            </description>
            <see-also>
                <ref type="managerEvent">PresenceStatus</ref>
            </see-also>
        </managerEventInstance>
    </managerEvent>
***/
 
#include "asterisk.h"
 
#include "asterisk/_private.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/presencestate.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/test.h"
 
/*! \brief Device state strings for printing */
static const struct {
    const char *string;
    enum ast_presence_state state;
 
} state2string[] = {
    { "not_set", AST_PRESENCE_NOT_SET},
    { "unavailable", AST_PRESENCE_UNAVAILABLE },
    { "available", AST_PRESENCE_AVAILABLE},
    { "away", AST_PRESENCE_AWAY},
    { "xa", AST_PRESENCE_XA},
    { "chat", AST_PRESENCE_CHAT},
    { "dnd", AST_PRESENCE_DND},
};
 
static struct ast_manager_event_blob *presence_state_to_ami(struct stasis_message *msg);
 
STASIS_MESSAGE_TYPE_DEFN(ast_presence_state_message_type,
    .to_ami = presence_state_to_ami,
);
struct stasis_topic *presence_state_topic_all;
struct stasis_cache *presence_state_cache;
struct stasis_caching_topic *presence_state_topic_cached;
 
/*! \brief  A presence state provider */
struct presence_state_provider {
    char label[40];
    ast_presence_state_prov_cb_type callback;
    AST_RWLIST_ENTRY(presence_state_provider) list;
};
 
/*! \brief A list of providers */
static AST_RWLIST_HEAD_STATIC(presence_state_providers, presence_state_provider);
 
const char *ast_presence_state2str(enum ast_presence_state state)
{
    int i;
    for (i = 0; i < ARRAY_LEN(state2string); i++) {
        if (state == state2string[i].state) {
            return state2string[i].string;
        }
    }
    return "";
}
 
enum ast_presence_state ast_presence_state_val(const char *val)
{
    int i;
    for (i = 0; i < ARRAY_LEN(state2string); i++) {
        if (!strcasecmp(val, state2string[i].string)) {
            return state2string[i].state;
        }
    }
    return AST_PRESENCE_INVALID;
}
 
static enum ast_presence_state presence_state_cached(const char *presence_provider, char **subtype, char **message)
{
    enum ast_presence_state res = AST_PRESENCE_INVALID;
    RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
    struct ast_presence_state_message *presence_state;
 
    msg = stasis_cache_get(ast_presence_state_cache(), ast_presence_state_message_type(), presence_provider);
 
    if (!msg) {
        return res;
    }
 
    presence_state = stasis_message_data(msg);
    res = presence_state->state;
 
    *subtype = !ast_strlen_zero(presence_state->subtype) ? ast_strdup(presence_state->subtype) : NULL;
    *message = !ast_strlen_zero(presence_state->message) ? ast_strdup(presence_state->message) : NULL;
 
    return res;
}
 
static enum ast_presence_state ast_presence_state_helper(const char *presence_provider, char **subtype, char **message, int check_cache)
{
    char *labels = ast_strdupa(presence_provider);
    char *label;
    enum ast_presence_state state = AST_PRESENCE_INVALID;
    enum ast_presence_state state_order[] = {
        [AST_PRESENCE_INVALID]     = 0,
        [AST_PRESENCE_NOT_SET]     = 1,
        [AST_PRESENCE_AVAILABLE]   = 2,
        [AST_PRESENCE_UNAVAILABLE] = 3,
        [AST_PRESENCE_CHAT]        = 4,
        [AST_PRESENCE_AWAY]        = 5,
        [AST_PRESENCE_XA]          = 6,
        [AST_PRESENCE_DND]         = 7
    };
 
    *subtype = NULL;
    *message = NULL;
 
    while ((label = strsep(&labels, "&"))) {
        enum ast_presence_state next_state = AST_PRESENCE_INVALID;
        char *next_subtype = NULL;
        char *next_message = NULL;
 
        if (check_cache) {
            next_state = presence_state_cached(label, &next_subtype, &next_message);
        }
 
        if (next_state == AST_PRESENCE_INVALID) {
            struct presence_state_provider *provider;
            const struct ast_channel_tech *chan_tech;
            char *address;
 
            if ((address = strchr(label, '/'))) {
                *address++ = '\0';
 
                if ((chan_tech = ast_get_channel_tech(label)) && chan_tech->presencestate) {
                    next_state = chan_tech->presencestate(address, &next_subtype, &next_message);
                }
            } else if ((address = strchr(label, ':'))) {
                *address++ = '\0';
 
                AST_RWLIST_RDLOCK(&presence_state_providers);
                AST_RWLIST_TRAVERSE(&presence_state_providers, provider, list) {
                    ast_debug(5, "Checking provider %s with %s\n", provider->label, label);
 
                    if (!strcasecmp(provider->label, label)) {
                        next_state = provider->callback(address, &next_subtype, &next_message);
                        break;
                    }
                }
                AST_RWLIST_UNLOCK(&presence_state_providers);
 
                if (!provider) {
                    ast_log(LOG_WARNING, "No provider found for label: %s\n", label);
                }
            } else {
                ast_log(LOG_WARNING, "No label found for presence state provider: %s\n", label);
            }
        }
 
        if (state_order[next_state] > state_order[state]) {
            state = next_state;
 
            ast_free(*subtype);
            ast_free(*message);
 
            *subtype = next_subtype;
            *message = next_message;
        }
    }
 
    return state;
}
 
enum ast_presence_state ast_presence_state(const char *presence_provider, char **subtype, char **message)
{
    return ast_presence_state_helper(presence_provider, subtype, message, 1);
}
 
enum ast_presence_state ast_presence_state_nocache(const char *presence_provider, char **subtype, char **message)
{
    return ast_presence_state_helper(presence_provider, subtype, message, 0);
}
 
int ast_presence_state_prov_add(const char *label, ast_presence_state_prov_cb_type callback)
{
    struct presence_state_provider *provider;
 
    if (!callback || !(provider = ast_calloc(1, sizeof(*provider)))) {
        return -1;
    }
 
    provider->callback = callback;
    ast_copy_string(provider->label, label, sizeof(provider->label));
 
    AST_RWLIST_WRLOCK(&presence_state_providers);
    AST_RWLIST_INSERT_HEAD(&presence_state_providers, provider, list);
    AST_RWLIST_UNLOCK(&presence_state_providers);
 
    return 0;
}
int ast_presence_state_prov_del(const char *label)
{
    struct presence_state_provider *provider;
    int res = -1;
 
    AST_RWLIST_WRLOCK(&presence_state_providers);
    AST_RWLIST_TRAVERSE_SAFE_BEGIN(&presence_state_providers, provider, list) {
        if (!strcasecmp(provider->label, label)) {
            AST_RWLIST_REMOVE_CURRENT(list);
            ast_free(provider);
            res = 0;
            break;
        }
    }
    AST_RWLIST_TRAVERSE_SAFE_END;
    AST_RWLIST_UNLOCK(&presence_state_providers);
 
    return res;
}
 
static void presence_state_dtor(void *obj)
{
    struct ast_presence_state_message *presence_state = obj;
    ast_string_field_free_memory(presence_state);
}
 
static struct ast_presence_state_message *presence_state_alloc(const char *provider,
        enum ast_presence_state state,
        const char *subtype,
        const char *message)
{
    RAII_VAR(struct ast_presence_state_message *, presence_state, ao2_alloc(sizeof(*presence_state), presence_state_dtor), ao2_cleanup);
 
    if (!presence_state || ast_string_field_init(presence_state, 256)) {
        return NULL;
    }
 
    presence_state->state = state;
    ast_string_field_set(presence_state, provider, provider);
    ast_string_field_set(presence_state, subtype, S_OR(subtype, ""));
    ast_string_field_set(presence_state, message, S_OR(message, ""));
 
    ao2_ref(presence_state, +1);
    return presence_state;
}
 
static void presence_state_event(const char *provider,
        enum ast_presence_state state,
        const char *subtype,
        const char *message)
{
    RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
    RAII_VAR(struct ast_presence_state_message *, presence_state, NULL, ao2_cleanup);
 
    if (!ast_presence_state_message_type()) {
        return;
    }
 
    presence_state = presence_state_alloc(provider, state, subtype, message);
    if (!presence_state) {
        return;
    }
 
    msg = stasis_message_create(ast_presence_state_message_type(), presence_state);
    if (!msg) {
        return;
    }
 
    stasis_publish(ast_presence_state_topic_all(), msg);
}
 
static void do_presence_state_change(const char *provider)
{
    char *subtype = NULL;
    char *message = NULL;
    enum ast_presence_state state;
 
    state = ast_presence_state_helper(provider, &subtype, &message, 0);
 
    if (state == AST_PRESENCE_INVALID) {
        return;
    }
 
    presence_state_event(provider, state, subtype, message);
    ast_free(subtype);
    ast_free(message);
}
 
int ast_presence_state_changed_literal(enum ast_presence_state state,
        const char *subtype,
        const char *message,
        const char *presence_provider)
{
    if (state == AST_PRESENCE_NOT_SET) {
        do_presence_state_change(presence_provider);
    } else {
        presence_state_event(presence_provider, state, subtype, message);
    }
 
    return 0;
}
 
int ast_presence_state_changed(enum ast_presence_state state,
        const char *subtype,
        const char *message,
        const char *fmt, ...)
{
    char buf[AST_MAX_EXTENSION];
    va_list ap;
 
    va_start(ap, fmt);
    vsnprintf(buf, sizeof(buf), fmt, ap);
    va_end(ap);
 
    return ast_presence_state_changed_literal(state, subtype, message, buf);
}
 
struct stasis_topic *ast_presence_state_topic_all(void)
{
    return presence_state_topic_all;
}
 
struct stasis_cache *ast_presence_state_cache(void)
{
    return presence_state_cache;
}
 
struct stasis_topic *ast_presence_state_topic_cached(void)
{
    return stasis_caching_get_topic(presence_state_topic_cached);
}
 
static const char *presence_state_get_id(struct stasis_message *msg)
{
    struct ast_presence_state_message *presence_state = stasis_message_data(msg);
 
    if (stasis_message_type(msg) != ast_presence_state_message_type()) {
        return NULL;
    }
 
    return presence_state->provider;
}
 
#if defined(TEST_FRAMEWORK)
 
#define TEST_CATEGORY "/main/presence/"
 
static int presence_test_alice_state = AST_PRESENCE_UNAVAILABLE;
static int presence_test_bob_state = AST_PRESENCE_UNAVAILABLE;
 
static int presence_test_presencestate(const char *label, char **subtype, char **message)
{
    if (!strcmp(label, "Alice")) {
        return presence_test_alice_state;
    } else if (!strcmp(label, "Bob")) {
        return presence_test_bob_state;
    } else {
        return AST_PRESENCE_UNAVAILABLE;
    }
}
 
static struct ast_channel_tech presence_test_tech = {
    .type = "PresenceTestChannel",
    .description = "Presence test technology",
    .presencestate = presence_test_presencestate,
};
 
AST_TEST_DEFINE(test_presence_chan)
{
    int res = AST_TEST_FAIL;
    char provider[80];
    enum ast_presence_state state;
    char *subtype = NULL, *message = NULL;
 
    switch (cmd) {
    case TEST_INIT:
        info->name = "channel_presence";
        info->category = TEST_CATEGORY;
        info->summary = "Channel presence state tests";
        info->description = "Creates test channel technology and then test the presence state callback";
        return AST_TEST_NOT_RUN;
    case TEST_EXECUTE:
        break;
    }
 
    if (ast_channel_register(&presence_test_tech)) {
        ast_log(LOG_WARNING, "Unable to register channel type '%s'\n", presence_test_tech.type);
        goto presence_test_cleanup;
    }
 
    /* Check Alice's state */
    snprintf(provider, sizeof(provider), "%s/Alice", presence_test_tech.type);
 
    presence_test_alice_state = AST_PRESENCE_AVAILABLE;
    state = ast_presence_state_nocache(provider, &subtype, &message);
 
    if (state != presence_test_alice_state) {
        ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
            provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_alice_state));
        goto presence_test_cleanup;
    }
 
    /* Check Alice's and Bob's state, Alice's should win as DND > AVAILABLE */
    snprintf(provider, sizeof(provider), "%s/Alice&%s/Bob", presence_test_tech.type, presence_test_tech.type);
 
    presence_test_alice_state = AST_PRESENCE_DND;
    presence_test_bob_state = AST_PRESENCE_UNAVAILABLE;
    state = ast_presence_state_nocache(provider, &subtype, &message);
 
    if (state != presence_test_alice_state) {
        ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
            provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_alice_state));
        goto presence_test_cleanup;
        }
 
    /* Check Alice's and Bob's state, Bob's should now win as AVAILABLE < UNAVAILABLE */
    presence_test_alice_state = AST_PRESENCE_AVAILABLE;
    state = ast_presence_state_nocache(provider, &subtype, &message);
 
    if (state != presence_test_bob_state) {
        ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
            provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_bob_state));
        goto presence_test_cleanup;
    }
 
    res = AST_TEST_PASS;
 
presence_test_cleanup:
    ast_channel_unregister(&presence_test_tech);
    ast_free(subtype);
    ast_free(message);
 
    return res;
}
#endif
 
static void presence_state_engine_cleanup(void)
{
    ao2_cleanup(presence_state_topic_all);
    presence_state_topic_all = NULL;
    ao2_cleanup(presence_state_cache);
    presence_state_cache = NULL;
    presence_state_topic_cached = stasis_caching_unsubscribe_and_join(presence_state_topic_cached);
    STASIS_MESSAGE_TYPE_CLEANUP(ast_presence_state_message_type);
    AST_TEST_UNREGISTER(test_presence_chan);
}
 
int ast_presence_state_engine_init(void)
{
    ast_register_cleanup(presence_state_engine_cleanup);
 
    if (STASIS_MESSAGE_TYPE_INIT(ast_presence_state_message_type) != 0) {
        return -1;
    }
 
    presence_state_topic_all = stasis_topic_create("presence_state:all");
    if (!presence_state_topic_all) {
        return -1;
    }
 
    presence_state_cache = stasis_cache_create(presence_state_get_id);
    if (!presence_state_cache) {
        return -1;
    }
 
    presence_state_topic_cached = stasis_caching_topic_create(presence_state_topic_all, presence_state_cache);
    if (!presence_state_topic_cached) {
        return -1;
    }
    stasis_caching_accept_message_type(presence_state_topic_cached, ast_presence_state_message_type());
    stasis_caching_set_filter(presence_state_topic_cached, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);
 
    AST_TEST_REGISTER(test_presence_chan);
 
    return 0;
}
 
static struct ast_manager_event_blob *presence_state_to_ami(struct stasis_message *msg)
{
    struct ast_presence_state_message *presence_state = stasis_message_data(msg);
    struct ast_manager_event_blob *res;
 
    char *subtype = ast_escape_c_alloc(presence_state->subtype);
    char *message = ast_escape_c_alloc(presence_state->message);
 
    res = ast_manager_event_blob_create(EVENT_FLAG_CALL, "PresenceStateChange",
        "Presentity: %s\r\n"
        "Status: %s\r\n"
        "Subtype: %s\r\n"
        "Message: %s\r\n",
        presence_state->provider,
        ast_presence_state2str(presence_state->state),
        subtype ?: "",
                message ?: "");
 
    ast_free(subtype);
    ast_free(message);
 
    return res;
}