res_sorcery_realtime.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Joshua Colp <jcolp@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 Sorcery Realtime Object Wizard
 *
 * \author Joshua Colp <jcolp@digium.com>
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <regex.h>
 
#include "asterisk/module.h"
#include "asterisk/sorcery.h"
 
/*! \brief They key field used to store the unique identifier for the object */
#define UUID_FIELD "id"
 
enum unqualified_fetch {
    UNQUALIFIED_FETCH_NO,
    UNQUALIFIED_FETCH_WARN,
    UNQUALIFIED_FETCH_YES,
    UNQUALIFIED_FETCH_ERROR,
};
 
struct sorcery_config {
    enum unqualified_fetch fetch;
    char family[];
};
 
static void *sorcery_realtime_open(const char *data);
static int sorcery_realtime_create(const struct ast_sorcery *sorcery, void *data, void *object);
static void *sorcery_realtime_retrieve_id(const struct ast_sorcery *sorcery, void *data, const char *type, const char *id);
static void *sorcery_realtime_retrieve_fields(const struct ast_sorcery *sorcery, void *data, const char *type, const struct ast_variable *fields);
static void sorcery_realtime_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects,
                         const struct ast_variable *fields);
static void sorcery_realtime_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *regex);
static void sorcery_realtime_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type,
                         struct ao2_container *objects, const char *prefix, const size_t prefix_len);
static int sorcery_realtime_update(const struct ast_sorcery *sorcery, void *data, void *object);
static int sorcery_realtime_delete(const struct ast_sorcery *sorcery, void *data, void *object);
static void sorcery_realtime_close(void *data);
 
static struct ast_sorcery_wizard realtime_object_wizard = {
    .name = "realtime",
    .open = sorcery_realtime_open,
    .create = sorcery_realtime_create,
    .retrieve_id = sorcery_realtime_retrieve_id,
    .retrieve_fields = sorcery_realtime_retrieve_fields,
    .retrieve_multiple = sorcery_realtime_retrieve_multiple,
    .retrieve_regex = sorcery_realtime_retrieve_regex,
    .retrieve_prefix = sorcery_realtime_retrieve_prefix,
    .update = sorcery_realtime_update,
    .delete = sorcery_realtime_delete,
    .close = sorcery_realtime_close,
};
 
static int sorcery_realtime_create(const struct ast_sorcery *sorcery, void *data, void *object)
{
    struct sorcery_config *config = data;
    RAII_VAR(struct ast_variable *, fields, ast_sorcery_objectset_create(sorcery, object), ast_variables_destroy);
    struct ast_variable *id = ast_variable_new(UUID_FIELD, ast_sorcery_object_get_id(object), "");
 
    if (!fields || !id) {
        ast_variables_destroy(id);
        return -1;
    }
 
    /* Place the identifier at the front for sanity sake */
    id->next = fields;
    fields = id;
 
    return (ast_store_realtime_fields(config->family, fields) <= 0) ? -1 : 0;
}
 
/*! \brief Internal helper function which returns a filtered objectset.
 *
 * The following are filtered out of the objectset:
 * \li The id field. This is returned to the caller in an out parameter.
 * \li Fields that are not registered with sorcery.
 *
 * \param objectset Objectset to filter.
 * \param[out] id The ID of the sorcery object, as found in the objectset.
 * \param sorcery The sorcery instance that is requesting an objectset.
 * \param type The object type
 *
 * \return The filtered objectset
 */
static struct ast_variable *sorcery_realtime_filter_objectset(struct ast_variable *objectset, struct ast_variable **id,
        const struct ast_sorcery *sorcery, const char *type)
{
    struct ast_variable *previous = NULL, *field = objectset;
    struct ast_sorcery_object_type *object_type;
 
    object_type = ast_sorcery_get_object_type(sorcery, type);
    if (!object_type) {
        ast_log(LOG_WARNING, "Unknown sorcery object type %s. Expect errors\n", type);
        /* Continue since we still want to filter out the id */
    }
 
    while (field) {
        int remove_field = 0;
        int delete_field = 0;
 
        if (!strcmp(field->name, UUID_FIELD)) {
            *id = field;
            remove_field = 1;
        } else if (object_type &&
                !ast_sorcery_is_object_field_registered(object_type, field->name)) {
            ast_debug(1, "Filtering out realtime field '%s' from retrieval\n", field->name);
            remove_field = 1;
            delete_field = 1;
        }
 
        if (remove_field) {
            struct ast_variable *removed;
 
            if (previous) {
                previous->next = field->next;
            } else {
                objectset = field->next;
            }
 
            removed = field;
            field = field->next;
            removed->next = NULL;
            if (delete_field) {
                ast_variables_destroy(removed);
            }
        } else {
            previous = field;
            field = field->next;
        }
    }
 
    ao2_cleanup(object_type);
 
    return objectset;
}
 
static void *sorcery_realtime_retrieve_fields(const struct ast_sorcery *sorcery, void *data, const char *type, const struct ast_variable *fields)
{
    struct sorcery_config *config = data;
    RAII_VAR(struct ast_variable *, objectset, NULL, ast_variables_destroy);
    RAII_VAR(struct ast_variable *, id, NULL, ast_variables_destroy);
    void *object = NULL;
 
    if (!(objectset = ast_load_realtime_fields(config->family, fields))) {
        return NULL;
    }
 
    objectset = sorcery_realtime_filter_objectset(objectset, &id, sorcery, type);
 
    if (!id
        || !(object = ast_sorcery_alloc(sorcery, type, id->value))
        || ast_sorcery_objectset_apply(sorcery, object, objectset)) {
        ao2_cleanup(object);
        return NULL;
    }
 
    return object;
}
 
static void *sorcery_realtime_retrieve_id(const struct ast_sorcery *sorcery, void *data, const char *type, const char *id)
{
    RAII_VAR(struct ast_variable *, fields, ast_variable_new(UUID_FIELD, id, ""), ast_variables_destroy);
 
    return sorcery_realtime_retrieve_fields(sorcery, data, type, fields);
}
 
static void sorcery_realtime_retrieve_multiple(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const struct ast_variable *fields)
{
    struct sorcery_config *config = data;
    RAII_VAR(struct ast_config *, rows, NULL, ast_config_destroy);
    RAII_VAR(struct ast_variable *, all, NULL, ast_variables_destroy);
    struct ast_category *row = NULL;
 
    if (!fields) {
        char field[strlen(UUID_FIELD) + 6], value[2];
 
        if (config->fetch == UNQUALIFIED_FETCH_NO) {
            return;
        }
        if (config->fetch == UNQUALIFIED_FETCH_ERROR) {
            ast_log(LOG_ERROR, "Unqualified fetch prevented on %s\n", config->family);
            return;
        }
        if (config->fetch == UNQUALIFIED_FETCH_WARN) {
            ast_log(LOG_WARNING, "Unqualified fetch requested on %s\n", config->family);
        }
 
        /* If no fields have been specified we want all rows, so trick realtime into doing it */
        snprintf(field, sizeof(field), "%s LIKE", UUID_FIELD);
        snprintf(value, sizeof(value), "%%");
 
        if (!(all = ast_variable_new(field, value, ""))) {
            return;
        }
 
        fields = all;
    }
 
    if (!(rows = ast_load_realtime_multientry_fields(config->family, fields))) {
        return;
    }
 
    while ((row = ast_category_browse_filtered(rows, NULL, row, NULL))) {
        struct ast_variable *objectset = ast_category_detach_variables(row);
        RAII_VAR(struct ast_variable *, id, NULL, ast_variables_destroy);
        RAII_VAR(void *, object, NULL, ao2_cleanup);
 
        objectset = sorcery_realtime_filter_objectset(objectset, &id, sorcery, type);
 
        if (id
            && (object = ast_sorcery_alloc(sorcery, type, id->value))
            && !ast_sorcery_objectset_apply(sorcery, object, objectset)) {
            ao2_link(objects, object);
        }
 
        ast_variables_destroy(objectset);
    }
}
 
static void sorcery_realtime_retrieve_regex(const struct ast_sorcery *sorcery, void *data, const char *type, struct ao2_container *objects, const char *regex)
{
    char field[strlen(UUID_FIELD) + 6], value[strlen(regex) + 3];
    RAII_VAR(struct ast_variable *, fields, NULL, ast_variables_destroy);
 
    if (!ast_strlen_zero(regex)) {
        /* The realtime API provides no direct ability to do regex so for now we support a limited subset using pattern matching */
        snprintf(field, sizeof(field), "%s LIKE", UUID_FIELD);
        if (regex[0] == '^') {
            snprintf(value, sizeof(value), "%s%%", regex + 1);
        } else {
            snprintf(value, sizeof(value), "%%%s%%", regex);
        }
 
        if (!(fields = ast_variable_new(field, value, ""))) {
            return;
        }
    }
 
    sorcery_realtime_retrieve_multiple(sorcery, data, type, objects, fields);
}
 
static void sorcery_realtime_retrieve_prefix(const struct ast_sorcery *sorcery, void *data, const char *type,
                         struct ao2_container *objects, const char *prefix, const size_t prefix_len)
{
    char field[strlen(UUID_FIELD) + 6], value[prefix_len + 2];
    RAII_VAR(struct ast_variable *, fields, NULL, ast_variables_destroy);
 
    if (prefix_len) {
        snprintf(field, sizeof(field), "%s LIKE", UUID_FIELD);
        snprintf(value, sizeof(value), "%.*s%%", (int) prefix_len, prefix);
        if (!(fields = ast_variable_new(field, value, ""))) {
            return;
        }
    }
 
    sorcery_realtime_retrieve_multiple(sorcery, data, type, objects, fields);
}
 
static int sorcery_realtime_update(const struct ast_sorcery *sorcery, void *data, void *object)
{
    struct sorcery_config *config = data;
    RAII_VAR(struct ast_variable *, fields, ast_sorcery_objectset_create(sorcery, object), ast_variables_destroy);
    int ret;
    struct ast_variable *id;
 
    if (!fields) {
        return -1;
    }
 
    ret = ast_update_realtime_fields(config->family, UUID_FIELD, ast_sorcery_object_get_id(object), fields);
    if (ret < 0) {
        /* An error occurred */
        return -1;
    } else if (ret > 0) {
        /* The object was updated */
        return 0;
    }
 
    if (!ast_sorcery_update_or_create_on_update_miss) {
        /* The object does not exist (nothing was updated) and fallback disabled */
        return -1;
    }
 
    id = ast_variable_new(UUID_FIELD, ast_sorcery_object_get_id(object), "");
    if (!id) {
        return -1;
    }
 
    /* Place the identifier at the front for sanity sake */
    id->next = fields;
    fields = id;
 
    return (ast_store_realtime_fields(config->family, fields) <= 0) ? -1 : 0;
}
 
static int sorcery_realtime_delete(const struct ast_sorcery *sorcery, void *data, void *object)
{
    struct sorcery_config *config = data;
 
    return (ast_destroy_realtime_fields(config->family, UUID_FIELD, ast_sorcery_object_get_id(object), NULL) <= 0) ? -1 : 0;
}
 
static void *sorcery_realtime_open(const char *data)
{
    struct sorcery_config *config;
    char *tmp;
    char *family;
    char *option;
 
    /* We require a prefix for family string generation, or else stuff could mix together */
    if (ast_strlen_zero(data)) {
        return NULL;
    }
 
    tmp = ast_strdupa(data);
    family = strsep(&tmp, ",");
 
    if (!ast_realtime_is_mapping_defined(family)) {
        return NULL;
    }
 
    config = ast_calloc(1, sizeof(*config) + strlen(family) + 1);
    if (!config) {
        return NULL;
    }
 
    strcpy(config->family, family); /* Safe */
    config->fetch = UNQUALIFIED_FETCH_YES;
 
    while ((option = strsep(&tmp, ","))) {
        char *name = strsep(&option, "=");
        char *value = option;
 
        if (!strcasecmp(name, "allow_unqualified_fetch")) {
            if (ast_strlen_zero(value) || !strcasecmp(value, "yes")) {
                config->fetch = UNQUALIFIED_FETCH_YES;
            } else if (!strcasecmp(value, "no")) {
                config->fetch = UNQUALIFIED_FETCH_NO;
            } else if (!strcasecmp(value, "warn")) {
                config->fetch = UNQUALIFIED_FETCH_WARN;
            } else if (!strcasecmp(value, "error")) {
                config->fetch = UNQUALIFIED_FETCH_ERROR;
            } else {
                ast_log(LOG_ERROR, "Unrecognized value in %s:%s: '%s'\n", family, name, value);
                return NULL;
            }
        } else {
            ast_log(LOG_ERROR, "Unrecognized option in %s: '%s'\n", family, name);
            return NULL;
        }
    }
 
    return config;
}
 
static void sorcery_realtime_close(void *data)
{
    ast_free(data);
}
 
static int load_module(void)
{
    if (ast_sorcery_wizard_register(&realtime_object_wizard)) {
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int unload_module(void)
{
    ast_sorcery_wizard_unregister(&realtime_object_wizard);
    return 0;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "Sorcery Realtime Object Wizard",
    .support_level = AST_MODULE_SUPPORT_CORE,
    .load = load_module,
    .unload = unload_module,
    .load_pri = AST_MODPRI_REALTIME_DRIVER,
);