res_sorcery_realtime.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Joshua Colp <[email protected]>
 *
 * 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 <[email protected]>
 */

/*** 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);

   if (!fields) {
      return -1;
   }

   return (ast_update_realtime_fields(config->family, UUID_FIELD, ast_sorcery_object_get_id(object), 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,
);