Decouple subscription handling from NOTIFY/PUBLISH body generation.

When the PJSIP pubsub framework was created, subscription handlers were required
to state what event they handled along with what body types they knew how to
generate. While this serves well when implementing a base RFC, it has problems
when trying to extend the body to support non-standard or proprietary body
elements. The code also was NOTIFY-specific, meaning that when the time comes
that we start writing code to send out PUBLISH requests with MWI or presence
bodies, we would likely find ourselves duplicating code that had previously been
written.

This changeset introduces the concept of body generators and body supplements. A
body generator is responsible for allocating a native structure for a given body
type, providing the primary body content, converting the native structure to a
string, and deallocating resources. A body supplement takes the primary body
content (the native structure, not a string) generated by the body generator and
adds nonstandard elements to the body. With these elements living in their own
module, it becomes easy to extend our support for body types and to re-use
resources when sending a PUBLISH request.

Body generators and body supplements register themselves with the pubsub core,
similar to how subscription and publish handlers had done. Now, subscription
handlers do not need to know what type of body content they generate, but they
still need to inform the pubsub core about what the default body type for a
given event package is. The pubsub core keeps track of what body generators and
body supplements have been registered. When a SUBSCRIBE arrives, the pubsub core
will check that there is a subscription handler for the event in the SUBSCRIBE,
then it will check that there is a body generator that can provide the content
specified in the Accept header(s).

Because of the nature of body generators and supplements, it means
res_pjsip_exten_state and res_pjsip_mwi have been completely gutted. They no
longer worry about body types, instead calling
ast_sip_pubsub_generate_body_content() when they need to generate a NOTIFY body.

Review: https://reviewboard.asterisk.org/r/3150
........

Merged revisions 407016 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@407030 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 61 insertions, 202 deletions

diff --git a/res/res_pjsip_exten_state.c b/res/res_pjsip_exten_state.c
index f312a522c..819155f00 100644
--- a/res/res_pjsip_exten_state.c
+++ b/res/res_pjsip_exten_state.c
@@ -31,7 +31,7 @@
 
 #include "asterisk/res_pjsip.h"
 #include "asterisk/res_pjsip_pubsub.h"
-#include "asterisk/res_pjsip_exten_state.h"
+#include "asterisk/res_pjsip_body_generator_types.h"
 #include "asterisk/module.h"
 #include "asterisk/logger.h"
 #include "asterisk/astobj2.h"
@@ -41,43 +41,6 @@
 #define BODY_SIZE 1024
 #define EVENT_TYPE_SIZE 50
 
-AST_RWLIST_HEAD_STATIC(providers, ast_sip_exten_state_provider);
-
-/*!
- * \internal
- * \brief Find a provider based on the given accept body type.
- */
-static struct ast_sip_exten_state_provider *provider_by_type(const char *type)
-{
-	struct ast_sip_exten_state_provider *i;
-	SCOPED_LOCK(lock, &providers, AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK);
-	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&providers, i, next) {
-		if (!strcmp(i->body_type, type)) {
-			return i;
-		}
-	}
-	AST_RWLIST_TRAVERSE_SAFE_END;
-	return NULL;
-}
-
-/*!
- * \internal
- * \brief Find a provider based on the given accept body types.
- */
-static struct ast_sip_exten_state_provider *provider_by_types(const char *event_name,
-							      char **types, int count)
-{
-	int i;
-	struct ast_sip_exten_state_provider *res;
-	for (i = 0; i < count; ++i) {
-		if ((res = provider_by_type(types[i])) &&
-		    !strcmp(event_name, res->event_name)) {
-			return res;
-		}
-	}
-	return NULL;
-}
-
 /*!
  * \brief A subscription for extension state
  *
@@ -90,12 +53,6 @@ struct exten_state_subscription {
 	int id;
 	/*! The SIP subscription */
 	struct ast_sip_subscription *sip_sub;
-	/*! The name of the event the subscribed to */
-	char event_name[EVENT_TYPE_SIZE];
-	/*! The number of body types */
-	int body_types_count;
-	/*! The subscription body types */
-	char **body_types;
 	/*! Context in which subscription looks for updates */
 	char context[AST_MAX_CONTEXT];
 	/*! Extension within the context to receive updates from */
@@ -104,44 +61,40 @@ struct exten_state_subscription {
 	enum ast_extension_states last_exten_state;
 };
 
+#define DEFAULT_PRESENCE_BODY "application/pidf+xml"
+
+static void subscription_shutdown(struct ast_sip_subscription *sub);
+static struct ast_sip_subscription *new_subscribe(struct ast_sip_endpoint *endpoint,
+						  pjsip_rx_data *rdata);
+static void resubscribe(struct ast_sip_subscription *sub, pjsip_rx_data *rdata,
+			struct ast_sip_subscription_response_data *response_data);
+static void subscription_timeout(struct ast_sip_subscription *sub);
+static void subscription_terminated(struct ast_sip_subscription *sub,
+				    pjsip_rx_data *rdata);
+static void to_ami(struct ast_sip_subscription *sub,
+		   struct ast_str **buf);
+
+struct ast_sip_subscription_handler presence_handler = {
+	.event_name = "presence",
+	.accept = { DEFAULT_PRESENCE_BODY, },
+	.default_accept = DEFAULT_PRESENCE_BODY,
+	.subscription_shutdown = subscription_shutdown,
+	.new_subscribe = new_subscribe,
+	.resubscribe = resubscribe,
+	.subscription_timeout = subscription_timeout,
+	.subscription_terminated = subscription_terminated,
+	.to_ami = to_ami,
+};
+
 static void exten_state_subscription_destructor(void *obj)
 {
 	struct exten_state_subscription *sub = obj;
-	int i;
-
-	for (i = 0; i < sub->body_types_count; ++i) {
-		ast_free(sub->body_types[i]);
-	}
 
-	ast_free(sub->body_types);
 	ao2_cleanup(sub->sip_sub);
 }
 
 /*!
  * \internal
- * \brief Copies the body types the message wishes to subscribe to.
- */
-static void copy_body_types(pjsip_rx_data *rdata,
-			    struct exten_state_subscription *exten_state_sub)
-{
-	int i;
-	pjsip_accept_hdr *hdr = (pjsip_accept_hdr*)
-		pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_ACCEPT, NULL);
-
-	exten_state_sub->body_types_count = hdr->count;
-	exten_state_sub->body_types = ast_malloc(hdr->count * sizeof(char*));
-
-	for (i = 0; i < hdr->count; ++i) {
-		exten_state_sub->body_types[i] =
-			ast_malloc(hdr->values[i].slen * sizeof(char*) + 1);
-
-		ast_copy_string(exten_state_sub->body_types[i],
-				pj_strbuf(&hdr->values[i]), hdr->values[i].slen + 1);
-	}
-}
-
-/*!
- * \internal
  * \brief Initialize the last extension state to something outside
  * its usual states.
  */
@@ -157,11 +110,6 @@ static void copy_body_types(pjsip_rx_data *rdata,
 static struct exten_state_subscription *exten_state_subscription_alloc(
 	struct ast_sip_endpoint *endpoint, enum ast_sip_subscription_role role, pjsip_rx_data *rdata)
 {
-	static const pj_str_t event_name = { "Event", 5 };
-	pjsip_event_hdr *hdr = (pjsip_event_hdr*)pjsip_msg_find_hdr_by_name(
-		rdata->msg_info.msg, &event_name, NULL);
-
-	struct ast_sip_exten_state_provider *provider;
 	RAII_VAR(struct exten_state_subscription *, exten_state_sub,
 		 ao2_alloc(sizeof(*exten_state_sub), exten_state_subscription_destructor), ao2_cleanup);
 
@@ -169,19 +117,8 @@ static struct exten_state_subscription *exten_state_subscription_alloc(
 		return NULL;
 	}
 
-	ast_copy_pj_str(exten_state_sub->event_name, &hdr->event_type,
-			sizeof(exten_state_sub->event_name));
-
-	copy_body_types(rdata, exten_state_sub);
-	if (!(provider = provider_by_types(exten_state_sub->event_name,
-					   exten_state_sub->body_types,
-					   exten_state_sub->body_types_count))) {
-		ast_log(LOG_WARNING, "Unable to locate subscription handler\n");
-		return NULL;
-	}
-
 	if (!(exten_state_sub->sip_sub = ast_sip_create_subscription(
-		      provider->handler, role, endpoint, rdata))) {
+		      &presence_handler, role, endpoint, rdata))) {
 		ast_log(LOG_WARNING, "Unable to create SIP subscription for endpoint %s\n",
 			ast_sorcery_object_get_id(endpoint));
 		return NULL;
@@ -204,27 +141,13 @@ static void create_send_notify(struct exten_state_subscription *exten_state_sub,
 	pj_str_t reason_str;
 	const pj_str_t *reason_str_ptr = NULL;
 	pjsip_tx_data *tdata;
-	pjsip_dialog *dlg;
-	char local[PJSIP_MAX_URL_SIZE], remote[PJSIP_MAX_URL_SIZE];
 	struct ast_sip_body body;
 
-	struct ast_sip_exten_state_provider *provider = provider_by_types(
-		exten_state_sub->event_name, exten_state_sub->body_types,
-		exten_state_sub->body_types_count);
-
-	if (!provider) {
-		ast_log(LOG_ERROR, "Unable to locate provider for subscription\n");
-		return;
-	}
-
-	body.type = provider->type;
-	body.subtype = provider->subtype;
-
-	dlg = ast_sip_subscription_get_dlg(exten_state_sub->sip_sub);
-	ast_copy_pj_str(local, &dlg->local.info_str, sizeof(local));
-	ast_copy_pj_str(remote, &dlg->remote.info_str, sizeof(remote));
+	body.type = ast_sip_subscription_get_body_type(exten_state_sub->sip_sub);
+	body.subtype = ast_sip_subscription_get_body_subtype(exten_state_sub->sip_sub);
 
-	if (provider->create_body(exten_state_data, local, remote, &body_text)) {
+	if (ast_sip_pubsub_generate_body_content(body.type, body.subtype,
+				exten_state_data, &body_text)) {
 		ast_log(LOG_ERROR, "Unable to create body on NOTIFY request\n");
 		return;
 	}
@@ -262,13 +185,19 @@ static void send_notify(struct exten_state_subscription *exten_state_sub, const
 {
 	RAII_VAR(struct ao2_container*, info, NULL, ao2_cleanup);
 	char *subtype = NULL, *message = NULL;
-
+	pjsip_dialog *dlg;
 	struct ast_sip_exten_state_data exten_state_data = {
 		.exten = exten_state_sub->exten,
 		.presence_state = ast_hint_presence_state(NULL, exten_state_sub->context,
 							  exten_state_sub->exten, &subtype, &message),
 	};
 
+	dlg = ast_sip_subscription_get_dlg(exten_state_sub->sip_sub);
+	ast_copy_pj_str(exten_state_data.local, &dlg->local.info_str,
+			sizeof(exten_state_data.local));
+	ast_copy_pj_str(exten_state_data.remote, &dlg->remote.info_str,
+			sizeof(exten_state_data.remote));
+
 	if ((exten_state_data.exten_state = ast_extension_state_extended(
 		     NULL, exten_state_sub->context, exten_state_sub->exten, &info)) < 0) {
 
@@ -277,8 +206,12 @@ static void send_notify(struct exten_state_subscription *exten_state_sub, const
 		return;
 	}
 
+	exten_state_data.pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(),
+			"exten_state", 1024, 1024);
+
 	exten_state_data.device_state_info = info;
 	create_send_notify(exten_state_sub, reason, evsub_state, &exten_state_data);
+	pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), exten_state_data.pool);
 }
 
 struct notify_task_data {
@@ -300,6 +233,7 @@ static struct notify_task_data *alloc_notify_task_data(char *exten, struct exten
 {
 	struct notify_task_data *task_data =
 		ao2_alloc(sizeof(*task_data), notify_task_data_destructor);
+	struct pjsip_dialog *dlg;
 
 	if (!task_data) {
 		ast_log(LOG_WARNING, "Unable to create notify task data\n");
@@ -320,6 +254,12 @@ static struct notify_task_data *alloc_notify_task_data(char *exten, struct exten
 		ao2_ref(task_data->exten_state_data.device_state_info, +1);
 	}
 
+	dlg = ast_sip_subscription_get_dlg(exten_state_sub->sip_sub);
+	ast_copy_pj_str(task_data->exten_state_data.local, &dlg->local.info_str,
+			sizeof(task_data->exten_state_data.local));
+	ast_copy_pj_str(task_data->exten_state_data.remote, &dlg->remote.info_str,
+			sizeof(task_data->exten_state_data.remote));
+
 	if ((info->exten_state == AST_EXTENSION_DEACTIVATED) ||
 	    (info->exten_state == AST_EXTENSION_REMOVED)) {
 		task_data->evsub_state = PJSIP_EVSUB_STATE_TERMINATED;
@@ -334,9 +274,16 @@ static int notify_task(void *obj)
 {
 	RAII_VAR(struct notify_task_data *, task_data, obj, ao2_cleanup);
 
+	/* Pool allocation has to happen here so that we allocate within a PJLIB thread */
+	task_data->exten_state_data.pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(),
+			"exten_state", 1024, 1024);
+
 	create_send_notify(task_data->exten_state_sub, task_data->evsub_state ==
 			   PJSIP_EVSUB_STATE_TERMINATED ? "noresource" : NULL,
 			   task_data->evsub_state, &task_data->exten_state_data);
+
+	pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(),
+			task_data->exten_state_data.pool);
 	return 0;
 }
 
@@ -527,107 +474,19 @@ static void to_ami(struct ast_sip_subscription *sub,
 			       exten_state_sub->last_exten_state));
 }
 
-#define DEFAULT_PRESENCE_BODY "application/pidf+xml"
-
-/*!
- * \internal
- * \brief Create and register a subscription handler.
- *
- * Creates a subscription handler that can be registered with the pub/sub
- * framework for the given event_name and accept value.
- */
-static struct ast_sip_subscription_handler *create_and_register_handler(
-	const char *event_name, const char *accept)
+static int load_module(void)
 {
-	struct ast_sip_subscription_handler *handler =
-		ao2_alloc(sizeof(*handler), NULL);
-
-	if (!handler) {
-		return NULL;
-	}
-
-	handler->event_name = event_name;
-	handler->accept[0] = accept;
-	if (!strcmp(accept, DEFAULT_PRESENCE_BODY)) {
-		handler->handles_default_accept = 1;
-	}
-
-	handler->subscription_shutdown = subscription_shutdown;
-	handler->new_subscribe = new_subscribe;
-	handler->resubscribe = resubscribe;
-	handler->subscription_timeout = subscription_timeout;
-	handler->subscription_terminated = subscription_terminated;
-	handler->to_ami = to_ami;
-
-	if (ast_sip_register_subscription_handler(handler)) {
+	if (ast_sip_register_subscription_handler(&presence_handler)) {
 		ast_log(LOG_WARNING, "Unable to register subscription handler %s\n",
-			handler->event_name);
-		ao2_cleanup(handler);
-		return NULL;
+			presence_handler.event_name);
+		return AST_MODULE_LOAD_DECLINE;
 	}
-
-	return handler;
-}
-
-int ast_sip_register_exten_state_provider(struct ast_sip_exten_state_provider *obj)
-{
-	if (ast_strlen_zero(obj->type)) {
-		ast_log(LOG_WARNING, "Type not specified on provider for event %s\n",
-			obj->event_name);
-		return -1;
-	}
-
-	if (ast_strlen_zero(obj->subtype)) {
-		ast_log(LOG_WARNING, "Subtype not specified on provider for event %s\n",
-			obj->event_name);
-		return -1;
-	}
-
-	if (!obj->create_body) {
-		ast_log(LOG_WARNING, "Body handler not specified on provide for event %s\n",
-		    obj->event_name);
-		return -1;
-	}
-
-	if (!(obj->handler = create_and_register_handler(obj->event_name, obj->body_type))) {
-		ast_log(LOG_WARNING, "Handler could not be registered for provider event %s\n",
-		    obj->event_name);
-		return -1;
-	}
-
-	/* scope to avoid mix declarations */
-	{
-		SCOPED_LOCK(lock, &providers, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
-		AST_RWLIST_INSERT_TAIL(&providers, obj, next);
-		ast_module_ref(ast_module_info->self);
-	}
-
-	return 0;
-}
-
-void ast_sip_unregister_exten_state_provider(struct ast_sip_exten_state_provider *obj)
-{
-	struct ast_sip_exten_state_provider *i;
-	SCOPED_LOCK(lock, &providers, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
-	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&providers, i, next) {
-		if (i == obj) {
-			ast_sip_unregister_subscription_handler(i->handler);
-			ao2_cleanup(i->handler);
-			AST_RWLIST_REMOVE_CURRENT(next);
-			ast_module_unref(ast_module_info->self);
-			break;
-		}
-	}
-	AST_RWLIST_TRAVERSE_SAFE_END;
-}
-
-static int load_module(void)
-{
 	return AST_MODULE_LOAD_SUCCESS;
 }
 
 static int unload_module(void)
 {
+	ast_sip_unregister_subscription_handler(&presence_handler);
 	return 0;
 }