func_pjsip_contact.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.
 */

/*! \file
 *
 * \brief Get information about a PJSIP contact
 *
 * \author \verbatim Joshua Colp <[email protected]> \endverbatim
 *
 * \ingroup functions
 *
 */

/*** MODULEINFO
   <depend>pjproject</depend>
   <depend>res_pjsip</depend>
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include <pjsip.h>
#include <pjlib.h>

#include "asterisk/app.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/sorcery.h"
#include "asterisk/res_pjsip.h"

/*** DOCUMENTATION
   <function name="PJSIP_CONTACT" language="en_US">
      <synopsis>
         Get information about a PJSIP contact
      </synopsis>
      <syntax>
         <parameter name="name" required="true">
            <para>The name of the contact to query.</para>
         </parameter>
         <parameter name="field" required="true">
            <para>The configuration option for the contact to query for.
            Supported options are those fields on the
            <replaceable>contact</replaceable> object.</para>
            <enumlist>
               <configOptionToEnum>
                  <xi:include xpointer="xpointer(/docs/configInfo[@name='res_pjsip']/configFile[@name='pjsip.conf']/configObject[@name='contact']/configOption)"/>
               </configOptionToEnum>
               <enum name="rtt">
                  <para>The RTT of the last qualify</para>
               </enum>
               <enum name="status">
                  <para>Status of the contact</para>
               </enum>
            </enumlist>
         </parameter>
      </syntax>
   </function>
***/

static int contact_function_get_permanent(void *obj, void *arg, int flags)
{
   const char *id = arg;

   if (!strcmp(ast_sorcery_object_get_id(obj), id)) {
      return CMP_MATCH | CMP_STOP;
   }

   return 0;
}

static int pjsip_contact_function_read(struct ast_channel *chan,
   const char *cmd, char *data, struct ast_str **buf, ssize_t len)
{
   struct ast_sorcery *pjsip_sorcery;
   char *parsed_data = ast_strdupa(data);
   char *contact_name;
   RAII_VAR(struct ast_sip_contact *, contact_obj, NULL, ao2_cleanup);
   RAII_VAR(struct ast_sip_contact_status *, contact_status, NULL, ao2_cleanup);
   int res = 0;

   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(contact_name);
      AST_APP_ARG(field_name);
   );

   /* Check for zero arguments */
   if (ast_strlen_zero(parsed_data)) {
      ast_log(AST_LOG_ERROR, "Cannot call %s without arguments\n", cmd);
      return -1;
   }

   AST_STANDARD_APP_ARGS(args, parsed_data);

   if (ast_strlen_zero(args.contact_name)) {
      ast_log(AST_LOG_ERROR, "Cannot call %s without a contact name to query\n", cmd);
      return -1;
   }

   if (ast_strlen_zero(args.field_name)) {
      ast_log(AST_LOG_ERROR, "Cannot call %s with an empty field name to query\n", cmd);
      return -1;
   }

   pjsip_sorcery = ast_sip_get_sorcery();
   if (!pjsip_sorcery) {
      ast_log(AST_LOG_ERROR, "Unable to retrieve PJSIP configuration: sorcery object is NULL\n");
      return -1;
   }

   /* Determine if this is a permanent contact or a normal contact */
   if ((contact_name = strstr(args.contact_name, "@@"))) {
      size_t aor_name_len = contact_name - args.contact_name;
      char aor_name[aor_name_len + 1];
      RAII_VAR(struct ast_sip_aor *, aor_obj, NULL, ao2_cleanup);

      /* Grab only the AOR name so we can retrieve the AOR which will give us the contact */
      strncpy(aor_name, args.contact_name, aor_name_len);
      aor_name[aor_name_len] = '\0';

      aor_obj = ast_sorcery_retrieve_by_id(pjsip_sorcery, "aor", aor_name);
      if (!aor_obj) {
         ast_log(AST_LOG_WARNING, "Failed to retrieve information for contact '%s'\n", args.contact_name);
         return -1;
      }

      contact_obj = ao2_callback(aor_obj->permanent_contacts, 0, contact_function_get_permanent, args.contact_name);
   } else {
      contact_obj = ast_sorcery_retrieve_by_id(pjsip_sorcery, "contact", args.contact_name);
   }

   if (!contact_obj) {
      ast_log(AST_LOG_WARNING, "Failed to retrieve information for contact '%s'\n", args.contact_name);
      return -1;
   }

   contact_status = ast_sip_get_contact_status(contact_obj);

   if (!strcmp(args.field_name, "status")) {
      ast_str_set(buf, len, "%s", ast_sip_get_contact_status_label(contact_status ? contact_status->status : UNKNOWN));
   } else if (!strcmp(args.field_name, "rtt")) {
      if (!contact_status || contact_status->status != AVAILABLE) {
         ast_str_set(buf, len, "%s", "N/A");
      } else {
         ast_str_set(buf, len, "%" PRId64, contact_status->rtt);
      }
   } else {
      struct ast_variable *change_set;
      struct ast_variable *it_change_set;

      change_set = ast_sorcery_objectset_create(pjsip_sorcery, contact_obj);

      if (!change_set) {
         ast_log(AST_LOG_WARNING, "Failed to retrieve information for contact '%s': change set is NULL\n", args.contact_name);
         return -1;
      }

      for (it_change_set = change_set; it_change_set; it_change_set = it_change_set->next) {
         if (!strcmp(it_change_set->name, args.field_name)) {
            ast_str_set(buf, len, "%s", it_change_set->value);
            break;
         }
      }

      if (!it_change_set) {
         ast_log(AST_LOG_WARNING, "Unknown property '%s' for PJSIP contact\n", args.field_name);

         res = 1;
      }

      ast_variables_destroy(change_set);
   }

   return res;
}


static struct ast_custom_function pjsip_contact_function = {
   .name = "PJSIP_CONTACT",
   .read2 = pjsip_contact_function_read,
};

static int unload_module(void)
{
   return ast_custom_function_unregister(&pjsip_contact_function);
}

static int load_module(void)
{
   return ast_custom_function_register(&pjsip_contact_function);
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Get information about a PJSIP contact",
   .support_level = AST_MODULE_SUPPORT_CORE,
   .load = load_module,
   .unload = unload_module,
   .requires = "res_pjsip",
);