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, 193 insertions, 0 deletions

diff --git a/res/res_ais.c b/res/res_ais.c
new file mode 100644
index 000000000..884eb0d23
--- /dev/null
+++ b/res/res_ais.c
@@ -0,0 +1,193 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007 - 2008, 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 common code between the uses of the different AIS
+ * services.
+ */
+
+/*** MODULEINFO
+	<depend>SaClm</depend>
+	<depend>SaEvt</depend>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$");
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <pthread.h>
+
+#include "ais/ais.h"
+
+#include "asterisk/module.h"
+#include "asterisk/options.h"
+#include "asterisk/logger.h"
+#include "asterisk/channel.h"
+#include "asterisk/utils.h"
+#include "asterisk/cli.h"
+
+static struct {
+	pthread_t id;
+	unsigned int stop:1;
+} dispatch_thread = {
+	.id = AST_PTHREADT_NULL,
+};
+
+SaVersionT ais_version = { 'B', 1, 1 };
+
+static const struct ais_error {
+	SaAisErrorT error;
+	const char *desc;
+} ais_errors[] = {
+        { SA_AIS_OK, "OK" },
+        { SA_AIS_ERR_LIBRARY, "Library Error" },
+        { SA_AIS_ERR_VERSION, "Version Not Compatible" },
+        { SA_AIS_ERR_INIT, "Callback Not Registered" },
+        { SA_AIS_ERR_TIMEOUT, "Timeout" },
+        { SA_AIS_ERR_TRY_AGAIN , "Try Again" },
+        { SA_AIS_ERR_INVALID_PARAM, "Invalid Parameter" },
+        { SA_AIS_ERR_NO_MEMORY, "No Memory" },
+        { SA_AIS_ERR_BAD_HANDLE, "Invalid Handle" },
+        { SA_AIS_ERR_BUSY, "Resource Already In Use" },
+        { SA_AIS_ERR_ACCESS, "Access Denied" },
+        { SA_AIS_ERR_NOT_EXIST, "Does Not Exist" },
+        { SA_AIS_ERR_NAME_TOO_LONG, "Name Too Long" },
+        { SA_AIS_ERR_EXIST, "Already Exists" },
+        { SA_AIS_ERR_NO_SPACE, "Buffer Too Small" },
+        { SA_AIS_ERR_INTERRUPT, "Request Interrupted" },
+        { SA_AIS_ERR_NAME_NOT_FOUND, "Name Not Found" },
+        { SA_AIS_ERR_NO_RESOURCES, "Not Enough Resources" },
+        { SA_AIS_ERR_NOT_SUPPORTED, "Requested Function Not Supported" },
+        { SA_AIS_ERR_BAD_OPERATION, "Operation Not Allowed" },
+        { SA_AIS_ERR_FAILED_OPERATION, "Operation Failed" },
+        { SA_AIS_ERR_MESSAGE_ERROR, "Communication Error" },
+        { SA_AIS_ERR_QUEUE_FULL, "Destination Queue Full" },
+        { SA_AIS_ERR_QUEUE_NOT_AVAILABLE, "Destination Queue Not Available" },
+        { SA_AIS_ERR_BAD_FLAGS, "Invalid Flags" },
+        { SA_AIS_ERR_TOO_BIG, "Value Too Large" },
+        { SA_AIS_ERR_NO_SECTIONS, "No More Sections to Initialize" },
+};
+
+const char *ais_err2str(SaAisErrorT error)
+{
+	int x;
+
+	for (x = 0; x < ARRAY_LEN(ais_errors); x++) {
+		if (ais_errors[x].error == error)
+			return ais_errors[x].desc;
+	}
+
+	return "Unknown";
+}
+
+static void *dispatch_thread_handler(void *data)
+{
+	SaSelectionObjectT clm_fd, evt_fd, max_fd;
+	int res;
+	fd_set read_fds;
+	SaAisErrorT ais_res;
+
+	ais_res = saClmSelectionObjectGet(clm_handle, &clm_fd);
+	if (ais_res != SA_AIS_OK) {
+		ast_log(LOG_ERROR, "Failed to retrieve select fd for CLM service.  "
+			"This module will not operate.\n");
+		return NULL;
+	}
+
+	ais_res = saEvtSelectionObjectGet(evt_handle, &evt_fd);
+	if (ais_res != SA_AIS_OK) {
+		ast_log(LOG_ERROR, "Failed to retrieve select fd for EVT service.  "
+			"This module will not operate.\n");
+		return NULL;
+	}
+
+	max_fd = clm_fd > evt_fd ? clm_fd : evt_fd;
+
+	while (!dispatch_thread.stop) {
+		FD_ZERO(&read_fds);
+		FD_SET(clm_fd,  &read_fds);
+		FD_SET(evt_fd,  &read_fds);
+
+		res = ast_select(max_fd + 1, &read_fds, NULL, NULL, NULL);
+		if (res == -1 && errno != EINTR && errno != EAGAIN) {
+			ast_log(LOG_ERROR, "Select error (%s) dispatch thread going away now, "
+				"and the module will no longer operate.\n", strerror(errno));
+			break;
+		}
+
+		if (FD_ISSET(clm_fd,  &read_fds))
+			saClmDispatch(clm_handle,   SA_DISPATCH_ALL);
+		if (FD_ISSET(evt_fd,  &read_fds))
+			saEvtDispatch(evt_handle,   SA_DISPATCH_ALL);
+	}
+
+	return NULL;
+}
+
+static int load_module(void)
+{
+	if (ast_ais_clm_load_module())
+		goto return_error;
+
+	if (ast_ais_evt_load_module())
+		goto evt_failed;
+
+	if (ast_pthread_create_background(&dispatch_thread.id, NULL, 
+		dispatch_thread_handler, NULL)) {
+		ast_log(LOG_ERROR, "Error starting AIS dispatch thread.\n");
+		goto dispatch_failed;
+	}
+
+	return AST_MODULE_LOAD_SUCCESS;
+
+dispatch_failed:
+	ast_ais_evt_unload_module();
+evt_failed:
+	ast_ais_clm_unload_module();
+return_error:
+	return AST_MODULE_LOAD_DECLINE;
+}
+
+static int unload_module(void)
+{
+	ast_ais_clm_unload_module();
+	ast_ais_evt_unload_module();
+
+	if (dispatch_thread.id != AST_PTHREADT_NULL) {
+		dispatch_thread.stop = 1;
+		pthread_kill(dispatch_thread.id, SIGURG); /* poke! */
+		pthread_join(dispatch_thread.id, NULL);
+	}
+
+	return 0;
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "SAForum AIS");