Rename res_pjsip_keepalive res_pjsip_transport_management

ASTERISK-25796
Reported by George Joseph

AST-2016-005

Change-Id: Id322a05f927392293570599730050bc677d99433

1 files changed, 269 insertions, 0 deletions

diff --git a/res/res_pjsip_transport_management.c b/res/res_pjsip_transport_management.c
new file mode 100644
index 000000000..b854fc957
--- /dev/null
+++ b/res/res_pjsip_transport_management.c
@@ -0,0 +1,269 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2014, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@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.
+ */
+
+/*** MODULEINFO
+	<depend>pjproject</depend>
+	<depend>res_pjsip</depend>
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+#include <pjsip.h>
+#include <pjsip_ua.h>
+
+#include "asterisk/res_pjsip.h"
+#include "asterisk/module.h"
+#include "asterisk/astobj2.h"
+
+/*! \brief Number of buckets for keepalive transports */
+#define KEEPALIVE_TRANSPORTS_BUCKETS 53
+
+/*! \brief The keep alive packet to send */
+static const pj_str_t keepalive_packet = { "\r\n\r\n", 4 };
+
+/*! \brief Global container of active transports */
+static struct ao2_container *transports;
+
+/*! \brief Thread keeping things alive */
+static pthread_t keepalive_thread = AST_PTHREADT_NULL;
+
+/*! \brief The global interval at which to send keepalives */
+static unsigned int keepalive_interval;
+
+/*! \brief Existing transport manager callback that we need to invoke */
+static pjsip_tp_state_callback tpmgr_state_callback;
+
+/*! \brief Structure for transport to be kept alive */
+struct keepalive_transport {
+	/*! \brief The underlying PJSIP transport */
+	pjsip_transport *transport;
+};
+
+/*! \brief Callback function to send keepalive */
+static int keepalive_transport_cb(void *obj, void *arg, int flags)
+{
+	struct keepalive_transport *keepalive = obj;
+	pjsip_tpselector selector = {
+		.type = PJSIP_TPSELECTOR_TRANSPORT,
+		.u.transport = keepalive->transport,
+	};
+
+	pjsip_tpmgr_send_raw(pjsip_endpt_get_tpmgr(ast_sip_get_pjsip_endpoint()),
+		keepalive->transport->key.type, &selector, NULL, keepalive_packet.ptr, keepalive_packet.slen,
+		&keepalive->transport->key.rem_addr, pj_sockaddr_get_len(&keepalive->transport->key.rem_addr),
+		NULL, NULL);
+
+	return 0;
+}
+
+/*! \brief Thread which sends keepalives to all active connection-oriented transports */
+static void *keepalive_transport_thread(void *data)
+{
+	pj_thread_desc desc;
+	pj_thread_t *thread;
+
+	if (pj_thread_register("Asterisk Keepalive Thread", desc, &thread) != PJ_SUCCESS) {
+		ast_log(LOG_ERROR, "Could not register keepalive thread with PJLIB, keepalives will not occur.\n");
+		return NULL;
+	}
+
+	/* Once loaded this module just keeps on going as it is unsafe to stop and change the underlying
+	 * callback for the transport manager.
+	 */
+	while (1) {
+		sleep(keepalive_interval);
+		ao2_callback(transports, OBJ_NODATA, keepalive_transport_cb, NULL);
+	}
+
+	return NULL;
+}
+
+/*! \brief Destructor for keepalive transport */
+static void keepalive_transport_destroy(void *obj)
+{
+	struct keepalive_transport *keepalive = obj;
+
+	pjsip_transport_dec_ref(keepalive->transport);
+}
+
+/*! \brief Callback invoked when transport changes occur */
+static void keepalive_transport_state_callback(pjsip_transport *transport, pjsip_transport_state state,
+	const pjsip_transport_state_info *info)
+{
+	/* We only care about connection-oriented transports */
+	if (transport->flag & PJSIP_TRANSPORT_RELIABLE) {
+		struct keepalive_transport *keepalive;
+
+		switch (state) {
+		case PJSIP_TP_STATE_CONNECTED:
+			keepalive = ao2_alloc(sizeof(*keepalive), keepalive_transport_destroy);
+			if (keepalive) {
+				keepalive->transport = transport;
+				pjsip_transport_add_ref(keepalive->transport);
+				ao2_link(transports, keepalive);
+				ao2_ref(keepalive, -1);
+			}
+			break;
+		case PJSIP_TP_STATE_DISCONNECTED:
+			ao2_find(transports, transport->obj_name, OBJ_SEARCH_KEY | OBJ_NODATA | OBJ_UNLINK);
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* Forward to the old state callback if present */
+	if (tpmgr_state_callback) {
+		tpmgr_state_callback(transport, state, info);
+	}
+}
+
+/*! \brief Hashing function for keepalive transport */
+static int keepalive_transport_hash_fn(const void *obj, int flags)
+{
+	const struct keepalive_transport *object;
+	const char *key;
+
+	switch (flags & OBJ_SEARCH_MASK) {
+	case OBJ_SEARCH_KEY:
+		key = obj;
+		break;
+	case OBJ_SEARCH_OBJECT:
+		object = obj;
+		key = object->transport->obj_name;
+		break;
+	default:
+		/* Hash can only work on something with a full key. */
+		ast_assert(0);
+		return 0;
+	}
+	return ast_str_hash(key);
+}
+
+/*! \brief Comparison function for keepalive transport */
+static int keepalive_transport_cmp_fn(void *obj, void *arg, int flags)
+{
+	const struct keepalive_transport *object_left = obj;
+	const struct keepalive_transport *object_right = arg;
+	const char *right_key = arg;
+	int cmp;
+
+	switch (flags & OBJ_SEARCH_MASK) {
+	case OBJ_SEARCH_OBJECT:
+		right_key = object_right->transport->obj_name;
+		/* Fall through */
+	case OBJ_SEARCH_KEY:
+		cmp = strcmp(object_left->transport->obj_name, right_key);
+		break;
+	case OBJ_SEARCH_PARTIAL_KEY:
+		/*
+		 * We could also use a partial key struct containing a length
+		 * so strlen() does not get called for every comparison instead.
+		 */
+		cmp = strncmp(object_left->transport->obj_name, right_key, strlen(right_key));
+		break;
+	default:
+		/*
+		 * What arg points to is specific to this traversal callback
+		 * and has no special meaning to astobj2.
+		 */
+		cmp = 0;
+		break;
+	}
+
+	return !cmp ? CMP_MATCH | CMP_STOP : 0;
+}
+
+static void keepalive_global_loaded(const char *object_type)
+{
+	unsigned int new_interval = ast_sip_get_keep_alive_interval();
+	pjsip_tpmgr *tpmgr;
+
+	if (new_interval) {
+		keepalive_interval = new_interval;
+	} else if (keepalive_interval) {
+		ast_log(LOG_NOTICE, "Keepalive support can not be disabled once activated.\n");
+		return;
+	} else {
+		/* This will occur if no keepalive interval has been specified at initial start */
+		return;
+	}
+
+	if (keepalive_thread != AST_PTHREADT_NULL) {
+		return;
+	}
+
+	transports = ao2_container_alloc(KEEPALIVE_TRANSPORTS_BUCKETS, keepalive_transport_hash_fn,
+		keepalive_transport_cmp_fn);
+	if (!transports) {
+		ast_log(LOG_ERROR, "Could not create container for transports to perform keepalive on.\n");
+		return;
+	}
+
+	tpmgr = pjsip_endpt_get_tpmgr(ast_sip_get_pjsip_endpoint());
+	if (!tpmgr) {
+		ast_log(LOG_ERROR, "No transport manager to attach keepalive functionality to.\n");
+		ao2_ref(transports, -1);
+		return;
+	}
+
+	if (ast_pthread_create(&keepalive_thread, NULL, keepalive_transport_thread, NULL)) {
+		ast_log(LOG_ERROR, "Could not create thread for sending keepalive messages.\n");
+		ao2_ref(transports, -1);
+		return;
+	}
+
+	tpmgr_state_callback = pjsip_tpmgr_get_state_cb(tpmgr);
+	pjsip_tpmgr_set_state_cb(tpmgr, &keepalive_transport_state_callback);
+}
+
+/*! \brief Observer which is used to update our interval when the global setting changes */
+static struct ast_sorcery_observer keepalive_global_observer = {
+	.loaded = keepalive_global_loaded,
+};
+
+static int load_module(void)
+{
+	CHECK_PJSIP_MODULE_LOADED();
+
+	ast_sorcery_observer_add(ast_sip_get_sorcery(), "global", &keepalive_global_observer);
+	ast_sorcery_reload_object(ast_sip_get_sorcery(), "global");
+	ast_module_shutdown_ref(ast_module_info->self);
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int unload_module(void)
+{
+	/* This will never get called */
+	return 0;
+}
+
+static int reload_module(void)
+{
+	ast_sorcery_reload_object(ast_sip_get_sorcery(), "global");
+	return 0;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Stateful Connection Keepalive Support",
+		.support_level = AST_MODULE_SUPPORT_CORE,
+		.load = load_module,
+		.reload = reload_module,
+		.unload = unload_module,
+		.load_pri = AST_MODPRI_CHANNEL_DEPEND - 4,
+		   );