Merge another big set of changes from team/russell/events

This commit merges in the rest of the code needed to support distributed device
state.  There are two main parts to this commit.

Core changes:
 - The device state handling in the core has been updated to understand device
   state across a cluster of Asterisk servers.  Every time the state of a device
   changes, it looks at all of the device states on each node, and determines the
   aggregate device state.  That resulting device state is what is provided to
   modules in Asterisk that take actions based on the state of a device.

New module, res_ais:
 - A module has been written to facilitate the communication of events between
   nodes in a cluster of Asterisk servers.  This module uses the SAForum AIS
   (Service Availability Forum Application Interface Specification) CLM and EVT
   services (Cluster Management and Event) to handle this task.  This module
   currently supports sharing Voicemail MWI (Message Waiting Indication) and
   device state events between servers.  It has been tested with openais, though
   other implementations of the spec do exist.

For more information on testing distributed device state, see the following doc:
  - doc/distributed_devstate.txt


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@121559 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 165 insertions, 0 deletions

diff --git a/res/ais/clm.c b/res/ais/clm.c
new file mode 100644
index 000000000..5d7a356be
--- /dev/null
+++ b/res/ais/clm.c
@@ -0,0 +1,165 @@
+/*
+ * 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__, "$Revision$");
+
+#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 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)
+{
+
+}
+
+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;
+
+	ais_res = saClmInitialize(&clm_handle, &clm_callbacks, &ais_version);
+	if (ais_res != SA_AIS_OK) {
+		ast_log(LOG_ERROR, "Could not initialize cluster membership service: %s\n",
+			ais_err2str(ais_res));
+		return -1;
+	}
+
+	ast_cli_register_multiple(ais_cli, ARRAY_LEN(ais_cli));
+
+	return 0;
+}
+
+int ast_ais_clm_unload_module(void)
+{
+	SaAisErrorT ais_res;
+
+	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;
+}