res_pjsip_dialog_info_body_generator.c

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/*
 * asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2014, 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>pjproject</depend>
   <depend>res_pjsip</depend>
   <depend>res_pjsip_pubsub</depend>
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

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

#include "asterisk/module.h"
#include "asterisk/callerid.h"
#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_pubsub.h"
#include "asterisk/res_pjsip_presence_xml.h"
#include "asterisk/res_pjsip_body_generator_types.h"

/*! \brief Structure which contains dialog-info+xml state information */
struct dialog_info_xml_state {
   /*! \brief Version to place into the next NOTIFY */
   unsigned int version;
};

/*! \brief Destructor for dialog-info+xml information */
static void dialog_info_xml_state_destroy(void *obj)
{
   ast_free(obj);
}

/*! \brief Datastore for attaching dialog-info+xml state information */
static const struct ast_datastore_info dialog_info_xml_datastore = {
   .type = "dialog-info+xml",
   .destroy = dialog_info_xml_state_destroy,
};

static void *dialog_info_allocate_body(void *data)
{
   struct ast_sip_exten_state_data *state_data = data;

   return ast_sip_presence_xml_create_node(state_data->pool, NULL, "dialog-info");
}

/*!
 * \internal
 * \brief Find the channel that is causing the RINGING update, ref'd
 */
static struct ast_channel *find_ringing_channel(struct ao2_container *device_state_info)
{
   struct ao2_iterator citer;
   struct ast_device_state_info *device_state;
   struct ast_channel *c = NULL;
   struct timeval tv = {0,};

   /* iterate ringing devices and get the oldest of all causing channels */
   citer = ao2_iterator_init(device_state_info, 0);
   for (; (device_state = ao2_iterator_next(&citer)); ao2_ref(device_state, -1)) {
      if (!device_state->causing_channel || (device_state->device_state != AST_DEVICE_RINGING &&
            device_state->device_state != AST_DEVICE_RINGINUSE)) {
         continue;
      }
      ast_channel_lock(device_state->causing_channel);
      if (ast_tvzero(tv) || ast_tvcmp(ast_channel_creationtime(device_state->causing_channel), tv) < 0) {
         c = device_state->causing_channel;
         tv = ast_channel_creationtime(c);
      }
      ast_channel_unlock(device_state->causing_channel);
   }
   ao2_iterator_destroy(&citer);
   return c ? ast_channel_ref(c) : NULL;
}

static int dialog_info_generate_body_content(void *body, void *data)
{
   pj_xml_node *dialog_info = body, *dialog, *state;
   struct ast_datastore *datastore;
   struct dialog_info_xml_state *datastore_state;
   struct ast_sip_exten_state_data *state_data = data;
   char *local = ast_strdupa(state_data->local), *stripped, *statestring = NULL;
   char *remote = ast_strdupa(state_data->remote);
   char *pidfstate = NULL, *pidfnote = NULL;
   enum ast_sip_pidf_state local_state;
   char version_str[32], sanitized[PJSIP_MAX_URL_SIZE];
   struct ast_sip_endpoint *endpoint = NULL;
   unsigned int notify_early_inuse_ringing = 0;

   if (!local || !remote || !state_data->datastores) {
      return -1;
   }

   datastore = ast_datastores_find(state_data->datastores, "dialog-info+xml");
   if (!datastore) {
      const struct ast_json *version_json = NULL;

      datastore = ast_datastores_alloc_datastore(&dialog_info_xml_datastore, "dialog-info+xml");
      if (!datastore) {
         return -1;
      }

      datastore->data = ast_calloc(1, sizeof(struct dialog_info_xml_state));
      if (!datastore->data || ast_datastores_add(state_data->datastores, datastore)) {
         ao2_ref(datastore, -1);
         return -1;
      }
      datastore_state = datastore->data;

      if (state_data->sub) {
         version_json = ast_sip_subscription_get_persistence_data(state_data->sub);
      }

      if (version_json) {
         datastore_state->version = ast_json_integer_get(version_json);
         datastore_state->version++;
      } else {
         datastore_state->version = 0;
      }
   } else {
      datastore_state = datastore->data;
      datastore_state->version++;
   }

   stripped = ast_strip_quoted(local, "<", ">");
   ast_sip_sanitize_xml(stripped, sanitized, sizeof(sanitized));

   if (state_data->sub && (endpoint = ast_sip_subscription_get_endpoint(state_data->sub))) {
       notify_early_inuse_ringing = endpoint->notify_early_inuse_ringing;
       ao2_cleanup(endpoint);
   }
   ast_sip_presence_exten_state_to_str(state_data->exten_state, &statestring,
         &pidfstate, &pidfnote, &local_state, notify_early_inuse_ringing);

   ast_sip_presence_xml_create_attr(state_data->pool, dialog_info, "xmlns", "urn:ietf:params:xml:ns:dialog-info");

   snprintf(version_str, sizeof(version_str), "%u", datastore_state->version);
   ast_sip_presence_xml_create_attr(state_data->pool, dialog_info, "version", version_str);

   if (state_data->sub) {
      ast_sip_subscription_set_persistence_data(state_data->sub, ast_json_integer_create(datastore_state->version));
   }

   ast_sip_presence_xml_create_attr(state_data->pool, dialog_info, "state", "full");
   ast_sip_presence_xml_create_attr(state_data->pool, dialog_info, "entity", sanitized);

   dialog = ast_sip_presence_xml_create_node(state_data->pool, dialog_info, "dialog");
   ast_sip_presence_xml_create_attr(state_data->pool, dialog, "id", state_data->exten);
   if (!ast_strlen_zero(statestring) && !strcmp(statestring, "early")) {
      struct ast_channel *callee = NULL;
      char local_target[PJSIP_MAX_URL_SIZE + 32] = "";
      char *local_cid_name = NULL;
      pj_xml_node *local_node, *local_identity_node, *local_target_node;

      ast_sip_presence_xml_create_attr(state_data->pool, dialog, "direction", "recipient");

      if (state_data->device_state_info) {
         callee = find_ringing_channel(state_data->device_state_info);
      }

      if (callee) {
         static char *anonymous = "anonymous";
         static char *invalid = "anonymous.invalid";
         char *remote_cid_name;
         char *remote_connected_num;
         int remote_connected_num_restricted;
         char *local_caller_num;
         pjsip_dialog *dlg = ast_sip_subscription_get_dialog(state_data->sub);
         pjsip_sip_uri *dlg_remote_fromhdr = pjsip_uri_get_uri(dlg->local.info->uri);
         char remote_target[PJSIP_MAX_URL_SIZE + 32];
         char dlg_remote_uri[PJSIP_MAX_URL_SIZE];
         char *from_domain_stripped;
         char from_domain_sanitized[PJSIP_MAX_URL_SIZE];
         pj_xml_node *remote_node, *remote_identity_node, *remote_target_node;

         /* We use the local dialog URI to determine the domain to use in the XML itself */
         ast_copy_pj_str(dlg_remote_uri, &dlg_remote_fromhdr->host, sizeof(dlg_remote_uri));
         from_domain_stripped = ast_strip_quoted(dlg_remote_uri, "<", ">");
         ast_sip_sanitize_xml(from_domain_stripped, from_domain_sanitized, sizeof(from_domain_sanitized));

         ast_channel_lock(callee);

         /* The remote node uses the connected line information, so who is calling the
          * monitored endpoint.
          */
         remote_cid_name = S_COR(ast_channel_connected(callee)->id.name.valid,
            S_COR((ast_channel_connected(callee)->id.name.presentation &
                  AST_PRES_RESTRICTION) == AST_PRES_RESTRICTED, anonymous,
               ast_channel_connected(callee)->id.name.str), "");

         remote_connected_num_restricted = (ast_channel_connected(callee)->id.number.presentation &
            AST_PRES_RESTRICTION) == AST_PRES_RESTRICTED;
         remote_connected_num = S_COR(ast_channel_connected(callee)->id.number.valid,
            S_COR(remote_connected_num_restricted, anonymous,
               ast_channel_connected(callee)->id.number.str), "invalid");

         snprintf(remote_target, sizeof(remote_target), "sip:%s@%s", remote_connected_num,
            remote_connected_num_restricted ? invalid : from_domain_sanitized);

         /* The local node uses the callerid information, so what the callerid would be
          * if the monitored endpoint was calling.
          */
         local_cid_name = S_COR(ast_channel_caller(callee)->id.name.valid,
            ast_channel_caller(callee)->id.name.str, "");
         local_caller_num = S_COR(ast_channel_caller(callee)->id.number.valid,
            ast_channel_caller(callee)->id.number.str, "invalid");

         snprintf(local_target, sizeof(local_target), "sip:%s@%s", local_caller_num,
            from_domain_sanitized);

         ast_channel_unlock(callee);
         callee = ast_channel_unref(callee);

         remote_node = ast_sip_presence_xml_create_node(state_data->pool, dialog, "remote");
         remote_identity_node = ast_sip_presence_xml_create_node(state_data->pool, remote_node, "identity");
         remote_target_node = ast_sip_presence_xml_create_node(state_data->pool, remote_node, "target");

         pj_strdup2(state_data->pool, &remote_identity_node->content, remote_target);
         if (!ast_strlen_zero(remote_cid_name)) {
            ast_sip_presence_xml_create_attr(state_data->pool, remote_identity_node, "display", remote_cid_name);
         }
         ast_sip_presence_xml_create_attr(state_data->pool, remote_target_node, "uri", remote_target);
      }

      if (state_data->device_state_info) {
         local_node = ast_sip_presence_xml_create_node(state_data->pool, dialog, "local");
         local_identity_node = ast_sip_presence_xml_create_node(state_data->pool, local_node, "identity");
         local_target_node = ast_sip_presence_xml_create_node(state_data->pool, local_node, "target");

         /* If a channel is not available we fall back to the sanitized local URI instead */
         pj_strdup2(state_data->pool, &local_identity_node->content, S_OR(local_target, sanitized));
         if (!ast_strlen_zero(local_cid_name)) {
            ast_sip_presence_xml_create_attr(state_data->pool, local_identity_node, "display", local_cid_name);
         }
         ast_sip_presence_xml_create_attr(state_data->pool, local_target_node, "uri", S_OR(local_target, sanitized));
      }
   }

   state = ast_sip_presence_xml_create_node(state_data->pool, dialog, "state");
   pj_strdup2(state_data->pool, &state->content, statestring);

   if (state_data->exten_state == AST_EXTENSION_ONHOLD) {
      pj_xml_node *local_node, *target, *param;

      local_node = ast_sip_presence_xml_create_node(state_data->pool, dialog, "local");
      target = ast_sip_presence_xml_create_node(state_data->pool, local_node, "target");
      ast_sip_presence_xml_create_attr(state_data->pool, target, "uri", sanitized);
      param = ast_sip_presence_xml_create_node(state_data->pool, target, "param");
      ast_sip_presence_xml_create_attr(state_data->pool, param, "pname", "+sip.rendering");
      ast_sip_presence_xml_create_attr(state_data->pool, param, "pvalue", "no");
   }

   ao2_ref(datastore, -1);

   return 0;
}

/* The maximum number of times the ast_str() for the body text can grow before we declare an XML body
 * too large to send.
 */
#define MAX_STRING_GROWTHS 6

static void dialog_info_to_string(void *body, struct ast_str **str)
{
   pj_xml_node *dialog_info = body;
   int growths = 0;
   int size;

   do {
      size = pj_xml_print(dialog_info, ast_str_buffer(*str), ast_str_size(*str) - 1, PJ_TRUE);
      if (size <= AST_PJSIP_XML_PROLOG_LEN) {
         ast_str_make_space(str, ast_str_size(*str) * 2);
         ++growths;
      }
   } while (size <= AST_PJSIP_XML_PROLOG_LEN && growths < MAX_STRING_GROWTHS);
   if (size <= AST_PJSIP_XML_PROLOG_LEN) {
      ast_log(LOG_WARNING, "dialog-info+xml body text too large\n");
      return;
   }

   *(ast_str_buffer(*str) + size) = '\0';
   ast_str_update(*str);
}

static struct ast_sip_pubsub_body_generator dialog_info_body_generator = {
   .type = "application",
   .subtype = "dialog-info+xml",
   .body_type = AST_SIP_EXTEN_STATE_DATA,
   .allocate_body = dialog_info_allocate_body,
   .generate_body_content = dialog_info_generate_body_content,
   .to_string = dialog_info_to_string,
   /* No need for a destroy_body callback since we use a pool */
};

static int load_module(void)
{
   if (ast_sip_pubsub_register_body_generator(&dialog_info_body_generator)) {
      return AST_MODULE_LOAD_DECLINE;
   }

   return AST_MODULE_LOAD_SUCCESS;
}

static int unload_module(void)
{
   ast_sip_pubsub_unregister_body_generator(&dialog_info_body_generator);
   return 0;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Extension State Dialog Info+XML Provider",
   .support_level = AST_MODULE_SUPPORT_CORE,
   .load = load_module,
   .unload = unload_module,
   .load_pri = AST_MODPRI_CHANNEL_DEPEND,
   .requires = "res_pjsip,res_pjsip_pubsub",
);