clm.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007, Digium, Inc.
 *
 * Russell Bryant <russell@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
 * \author Russell Bryant <russell@digium.com>
 *
 * \brief Usage of the SAForum AIS (Application Interface Specification)
 *
 * \arg http://www.openais.org/
 *
 * This file contains the code specific to the use of the CLM
 * (Cluster Membership) Service.
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 359053 $");

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include "ais.h"

#include "asterisk/module.h"
#include "asterisk/utils.h"
#include "asterisk/cli.h"
#include "asterisk/logger.h"

SaClmHandleT clm_handle;
static SaAisErrorT clm_init_res;

static void clm_node_get_cb(SaInvocationT invocation,
   const SaClmClusterNodeT *cluster_node, SaAisErrorT error);
static void clm_track_cb(const SaClmClusterNotificationBufferT *notif_buffer,
   SaUint32T num_members, SaAisErrorT error);

static const SaClmCallbacksT clm_callbacks = {
   .saClmClusterNodeGetCallback = clm_node_get_cb,
   .saClmClusterTrackCallback   = clm_track_cb,
};

static void clm_node_get_cb(SaInvocationT invocation,
   const SaClmClusterNodeT *cluster_node, SaAisErrorT error)
{

}

static void clm_track_cb(const SaClmClusterNotificationBufferT *notif_buffer,
   SaUint32T num_members, SaAisErrorT error)
{
   unsigned int i;
   unsigned int node_joined = 0;

   ast_debug(1, "Cluster membership changed. Number of members: %u\n", num_members);

   for (i = 0; i < notif_buffer->numberOfItems; i++) {
      SaClmClusterNotificationT *notif = notif_buffer->notification + i;

      if (notif->clusterChange == SA_CLM_NODE_JOINED) {
         node_joined = 1;
         break;
      }
   }

   if (node_joined) {
      ast_debug(1, "A node has joined the cluster, dumping event cache.\n");
      ast_ais_cmd(AST_AIS_CMD_MEMBERSHIP_CHANGED);
   }
}

static char *ais_clm_show_members(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int i;
   SaClmClusterNotificationBufferT buf;
   SaClmClusterNotificationT notif[64];
   SaAisErrorT ais_res;

   switch (cmd) {
   case CLI_INIT:
      e->command = "ais clm show members";
      e->usage =
         "Usage: ais clm show members\n"
         "       List members of the cluster using the CLM (Cluster Membership) service.\n";
      return NULL;

   case CLI_GENERATE:
      return NULL;   /* no completion */
   }

   if (a->argc != e->args)
      return CLI_SHOWUSAGE;

   buf.notification = notif;
   buf.numberOfItems = ARRAY_LEN(notif);

   ais_res = saClmClusterTrack(clm_handle, SA_TRACK_CURRENT, &buf);
   if (ais_res != SA_AIS_OK) {
      ast_cli(a->fd, "Error retrieving current cluster members.\n");
      return CLI_FAILURE;
   }

   ast_cli(a->fd, "\n"
               "=============================================================\n"
               "=== Cluster Members =========================================\n"
               "=============================================================\n"
               "===\n");

   for (i = 0; i < buf.numberOfItems; i++) {
      SaClmClusterNodeT *node = &buf.notification[i].clusterNode;

      ast_cli(a->fd, "=== ---------------------------------------------------------\n"
                     "=== Node Name: %s\n"
                     "=== ==> ID: 0x%x\n"
                     "=== ==> Address: %s\n"
                     "=== ==> Member: %s\n",
                     (char *) node->nodeName.value, (int) node->nodeId,
                     (char *) node->nodeAddress.value,
                     node->member ? "Yes" : "No");

      ast_cli(a->fd, "=== ---------------------------------------------------------\n"
                     "===\n");
   }

   ast_cli(a->fd, "=============================================================\n"
                  "\n");

   return CLI_SUCCESS;
}

static struct ast_cli_entry ais_cli[] = {
   AST_CLI_DEFINE(ais_clm_show_members, "List current members of the cluster"),
};

int ast_ais_clm_load_module(void)
{
   SaAisErrorT ais_res;

   clm_init_res = saClmInitialize(&clm_handle, &clm_callbacks, &ais_version);
   if (clm_init_res != SA_AIS_OK) {
      ast_log(LOG_ERROR, "Could not initialize cluster membership service: %s\n",
         ais_err2str(clm_init_res));
      return -1;
   }

   ais_res = saClmClusterTrack(clm_handle, SA_TRACK_CHANGES, NULL);
   if (ais_res != SA_AIS_OK) {
      ast_log(LOG_ERROR, "Error starting tracking of cluster membership changes.\n");
   }

   ast_cli_register_multiple(ais_cli, ARRAY_LEN(ais_cli));

   return 0;
}

int ast_ais_clm_unload_module(void)
{
   SaAisErrorT ais_res;

   if (clm_init_res != SA_AIS_OK) {
      return 0;
   }

   ast_cli_unregister_multiple(ais_cli, ARRAY_LEN(ais_cli));

   ais_res = saClmFinalize(clm_handle);
   if (ais_res != SA_AIS_OK) {
      ast_log(LOG_ERROR, "Problem stopping cluster membership service: %s\n",
         ais_err2str(ais_res));
      return -1;
   }

   return 0;
}