test_dns_query_set.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2015, 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.
 */

/*** MODULEINFO
   <depend>TEST_FRAMEWORK</depend>
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include <arpa/nameser.h>
#include <arpa/inet.h>

#include "asterisk/test.h"
#include "asterisk/module.h"
#include "asterisk/vector.h"
#include "asterisk/dns_core.h"
#include "asterisk/dns_resolver.h"
#include "asterisk/dns_query_set.h"
#include "asterisk/dns_internal.h"

struct query_set_data {
   /*! Boolean indicator if query set has completed */
   int query_set_complete;
   /*! Number of times resolve() method has been called */
   int resolves;
   /*! Number of times resolve() method is allowed to be called */
   int resolves_allowed;
   /*! Number of times cancel() method has been called */
   int cancel;
   /*! Number of times cancel() method is allowed to be called */
   int cancel_allowed;
   ast_mutex_t lock;
   ast_cond_t cond;
};

static void query_set_data_destructor(void *obj)
{
   struct query_set_data *qsdata = obj;

   ast_mutex_destroy(&qsdata->lock);
   ast_cond_destroy(&qsdata->cond);
}

static struct query_set_data *query_set_data_alloc(void)
{
   struct query_set_data *qsdata;

   qsdata = ao2_alloc(sizeof(*qsdata), query_set_data_destructor);
   if (!qsdata) {
      return NULL;
   }

   ast_mutex_init(&qsdata->lock);
   ast_cond_init(&qsdata->cond, NULL);

   return qsdata;
}

#define DNS_ANSWER "Yes sirree"
#define DNS_ANSWER_SIZE strlen(DNS_ANSWER)

/*!
 * \brief Thread that performs asynchronous resolution.
 *
 * This thread uses the query's user data to determine how to
 * perform the resolution. If the allowed number of resolutions
 * has not been reached then this will succeed, otherwise the
 * query is expected to have been canceled.
 *
 * \param dns_query The ast_dns_query that is being performed
 * \return NULL
 */
static void *resolution_thread(void *dns_query)
{
   struct ast_dns_query *query = dns_query;
   struct ast_dns_query_set *query_set = ast_dns_query_get_data(query);
   struct query_set_data *qsdata = query_set->user_data;

   ast_assert(qsdata != NULL);

   ast_dns_resolver_set_result(query, 0, 0, NOERROR, "asterisk.org", DNS_ANSWER, DNS_ANSWER_SIZE);
   ast_dns_resolver_completed(query);

   ao2_ref(query, -1);
   return NULL;
}

/*!
 * \brief Resolver's resolve() method
 *
 * \param query The query that is to be resolved
 * \retval 0 Successfully created thread to perform the resolution
 * \retval non-zero Failed to create resolution thread
 */
static int query_set_resolve(struct ast_dns_query *query)
{
   struct ast_dns_query_set *query_set = ast_dns_query_get_data(query);
   struct query_set_data *qsdata = query_set->user_data;
   pthread_t resolver_thread;

   /* Only the queries which will not be canceled actually start a thread */
   if (qsdata->resolves++ < qsdata->cancel_allowed) {
      return 0;
   }

   return ast_pthread_create_detached(&resolver_thread, NULL, resolution_thread, ao2_bump(query));
}

/*!
 * \brief Resolver's cancel() method
 *
 * \param query The query to cancel
 * \return 0
 */
static int query_set_cancel(struct ast_dns_query *query)
{
   struct ast_dns_query_set *query_set = ast_dns_query_get_data(query);
   struct query_set_data *qsdata;
   int res = -1;

   if (!query_set) {
      return -1;
   }
   qsdata = query_set->user_data;

   if (qsdata->cancel++ < qsdata->cancel_allowed) {
      res = 0;
   }

   return res;
}

static struct ast_dns_resolver query_set_resolver = {
   .name = "query_set",
   .priority = 0,
   .resolve = query_set_resolve,
   .cancel = query_set_cancel,
};

/*!
 * \brief Callback which is invoked upon query set completion
 *
 * \param query_set The query set
 */
static void query_set_callback(const struct ast_dns_query_set *query_set)
{
   struct query_set_data *qsdata = ast_dns_query_set_get_data(query_set);

   ast_mutex_lock(&qsdata->lock);
   qsdata->query_set_complete = 1;
   ast_cond_signal(&qsdata->cond);
   ast_mutex_unlock(&qsdata->lock);
}

/*!
 * \brief Framework for running a query set DNS test
 *
 * This function serves as a common way of testing various numbers of queries in a
 * query set and optional canceling of them.
 *
 * \param test The test being run
 * \param resolve The number of queries that should be allowed to complete resolution
 * \param cancel The number of queries that should be allowed to be canceled
 */
static enum ast_test_result_state query_set_test(struct ast_test *test, int resolve, int cancel)
{
   int total = resolve + cancel;
   RAII_VAR(struct ast_dns_query_set *, query_set, NULL, ao2_cleanup);
   RAII_VAR(struct query_set_data *, qsdata, NULL, ao2_cleanup);
   enum ast_test_result_state res = AST_TEST_PASS;
   int idx;
   struct timespec timeout;

   if (ast_dns_resolver_register(&query_set_resolver)) {
      ast_test_status_update(test, "Failed to register query set DNS resolver\n");
      return AST_TEST_FAIL;
   }

   qsdata = query_set_data_alloc();
   if (!qsdata) {
      ast_test_status_update(test, "Failed to allocate data necessary for query set test\n");
      res = AST_TEST_FAIL;
      goto cleanup;
   }

   query_set = ast_dns_query_set_create();
   if (!query_set) {
      ast_test_status_update(test, "Failed to create DNS query set\n");
      res = AST_TEST_FAIL;
      goto cleanup;
   }

   qsdata->resolves_allowed = resolve;
   qsdata->cancel_allowed = cancel;

   for (idx = 0; idx < total; ++idx) {
      if (ast_dns_query_set_add(query_set, "asterisk.org", T_A, C_IN)) {
         ast_test_status_update(test, "Failed to add query to DNS query set\n");
         res = AST_TEST_FAIL;
         goto cleanup;
      }
   }

   if (ast_dns_query_set_num_queries(query_set) != total) {
      ast_test_status_update(test, "DNS query set does not contain the correct number of queries\n");
      res = AST_TEST_FAIL;
      goto cleanup;
   }

   ast_dns_query_set_resolve_async(query_set, query_set_callback, qsdata);

   if (cancel && (cancel == total)) {
      if (ast_dns_query_set_resolve_cancel(query_set)) {
         ast_test_status_update(test, "Failed to cancel DNS query set when it should be cancellable\n");
         res = AST_TEST_FAIL;
      }

      if (qsdata->query_set_complete) {
         ast_test_status_update(test, "Query set callback was invoked despite all queries being cancelled\n");
         res = AST_TEST_FAIL;
      }

      goto cleanup;
   } else if (cancel) {
      if (!ast_dns_query_set_resolve_cancel(query_set)) {
         ast_test_status_update(test, "Successfully cancelled DNS query set when it should not be possible\n");
         res = AST_TEST_FAIL;
         goto cleanup;
      }
   }

   timeout = ast_tsnow();
   timeout.tv_sec += 10;

   ast_mutex_lock(&qsdata->lock);
   while (!qsdata->query_set_complete) {
      if (ast_cond_timedwait(&qsdata->cond, &qsdata->lock, &timeout) == ETIMEDOUT) {
         break;
      }
   }
   ast_mutex_unlock(&qsdata->lock);

   if (!qsdata->query_set_complete) {
      ast_test_status_update(test, "Query set did not complete when it should have\n");
      res = AST_TEST_FAIL;
      goto cleanup;
   }

   for (idx = 0; idx < ast_dns_query_set_num_queries(query_set); ++idx) {
      const struct ast_dns_query *query = ast_dns_query_set_get(query_set, idx);

      if (strcmp(ast_dns_query_get_name(query), "asterisk.org")) {
         ast_test_status_update(test, "Query did not have expected name\n");
         res = AST_TEST_FAIL;
      }
      if (ast_dns_query_get_rr_type(query) != T_A) {
         ast_test_status_update(test, "Query did not have expected type\n");
         res = AST_TEST_FAIL;
      }
      if (ast_dns_query_get_rr_class(query) != C_IN) {
         ast_test_status_update(test, "Query did not have expected class\n");
         res = AST_TEST_FAIL;
      }
   }

cleanup:
   ast_dns_resolver_unregister(&query_set_resolver);
   return res;
}

AST_TEST_DEFINE(query_set)
{
   switch (cmd) {
   case TEST_INIT:
      info->name = "query_set";
      info->category = "/main/dns/query_set/";
      info->summary = "Test nominal asynchronous DNS query set";
      info->description =
         "This tests nominal query set in the following ways:\n"
         "\t* Multiple queries are added to a query set\n"
         "\t* The mock resolver is configured to respond to all queries\n"
         "\t* Asynchronous resolution of the query set is started\n"
         "\t* The mock resolver responds to all queries\n"
         "\t* We ensure that the query set callback is invoked upon completion";
      return AST_TEST_NOT_RUN;
   case TEST_EXECUTE:
      break;
   }

   return query_set_test(test, 4, 0);
}

AST_TEST_DEFINE(query_set_empty)
{
   switch (cmd) {
   case TEST_INIT:
      info->name = "query_set_empty";
      info->category = "/main/dns/query_set/";
      info->summary = "Test nominal asynchronous empty DNS query set";
      info->description =
         "This tests nominal query set in the following ways:\n"
         "\t* No queries are added to a query set\n"
         "\t* Asynchronous resolution of the query set is started\n"
         "\t* We ensure that the query set callback is invoked upon completion";
      return AST_TEST_NOT_RUN;
   case TEST_EXECUTE:
      break;
   }

   return query_set_test(test, 0, 0);
}

AST_TEST_DEFINE(query_set_nominal_cancel)
{
   switch (cmd) {
   case TEST_INIT:
      info->name = "query_set_nominal_cancel";
      info->category = "/main/dns/query_set/";
      info->summary = "Test nominal asynchronous DNS query set cancellation";
      info->description =
         "This tests nominal query set cancellation in the following ways:\n"
         "\t* Multiple queries are added to a query set\n"
         "\t* The mock resolver is configured to NOT respond to any queries\n"
         "\t* Asynchronous resolution of the query set is started\n"
         "\t* The query set is canceled and is confirmed to return with success";
      return AST_TEST_NOT_RUN;
   case TEST_EXECUTE:
      break;
   }

   return query_set_test(test, 0, 4);
}

AST_TEST_DEFINE(query_set_off_nominal_cancel)
{
   switch (cmd) {
   case TEST_INIT:
      info->name = "query_set_off_nominal_cancel";
      info->category = "/main/dns/query_set/";
      info->summary = "Test off-nominal asynchronous DNS query set cancellation";
      info->description =
         "This tests nominal query set cancellation in the following ways:\n"
         "\t* Multiple queries are added to a query set\n"
         "\t* The mock resolver is configured to respond to half the queries\n"
         "\t* Asynchronous resolution of the query set is started\n"
         "\t* The query set is canceled and is confirmed to return failure\n"
         "\t* The query set callback is confirmed to run, since it could not be fully canceled";
      return AST_TEST_NOT_RUN;
   case TEST_EXECUTE:
      break;
   }

   return query_set_test(test, 2, 2);
}

static int unload_module(void)
{
   AST_TEST_UNREGISTER(query_set);
   AST_TEST_UNREGISTER(query_set_empty);
   AST_TEST_UNREGISTER(query_set_nominal_cancel);
   AST_TEST_UNREGISTER(query_set_off_nominal_cancel);

   return 0;
}

static int load_module(void)
{
   AST_TEST_REGISTER(query_set);
   AST_TEST_REGISTER(query_set_empty);
   AST_TEST_REGISTER(query_set_nominal_cancel);
   AST_TEST_REGISTER(query_set_off_nominal_cancel);

   return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "DNS query set tests");