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, 25 insertions, 17 deletions

diff --git a/res/res_pjsip_mwi.c b/res/res_pjsip_mwi.c
index bb12aa5e9..9137b677b 100644
--- a/res/res_pjsip_mwi.c
+++ b/res/res_pjsip_mwi.c
@@ -31,6 +31,7 @@
 
 #include "asterisk/res_pjsip.h"
 #include "asterisk/res_pjsip_pubsub.h"
+#include "asterisk/res_pjsip_body_generator_types.h"
 #include "asterisk/module.h"
 #include "asterisk/logger.h"
 #include "asterisk/astobj2.h"
@@ -43,6 +44,10 @@ AO2_GLOBAL_OBJ_STATIC(unsolicited_mwi);
 
 #define STASIS_BUCKETS 13
 #define MWI_BUCKETS 53
+
+#define MWI_TYPE "application"
+#define MWI_SUBTYPE "simple-message-summary"
+
 static void mwi_subscription_shutdown(struct ast_sip_subscription *sub);
 static struct ast_sip_subscription *mwi_new_subscribe(struct ast_sip_endpoint *endpoint,
 		pjsip_rx_data *rdata);
@@ -58,8 +63,8 @@ static void mwi_to_ami(struct ast_sip_subscription *sub, struct ast_str **buf);
 
 static struct ast_sip_subscription_handler mwi_handler = {
 	.event_name = "message-summary",
-	.accept = { "application/simple-message-summary", },
-	.handles_default_accept = 1,
+	.accept = { MWI_TYPE"/"MWI_SUBTYPE, },
+	.default_accept =  MWI_TYPE"/"MWI_SUBTYPE,
 	.subscription_shutdown = mwi_subscription_shutdown,
 	.new_subscribe = mwi_new_subscribe,
 	.resubscribe = mwi_resubscribe,
@@ -223,17 +228,11 @@ static int mwi_sub_cmp(void *obj, void *arg, int flags)
 	return strcmp(mwi_sub1->id, mwi_sub2->id) ? 0 : CMP_MATCH;
 }
 
-struct message_accumulator {
-	int old_msgs;
-	int new_msgs;
-	const char *reason;
-};
-
 static int get_message_count(void *obj, void *arg, int flags)
 {
 	RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
 	struct mwi_stasis_subscription *mwi_stasis = obj;
-	struct message_accumulator *counter = arg;
+	struct ast_sip_message_accumulator *counter = arg;
 	struct ast_mwi_state *mwi_state;
 
 	msg = stasis_cache_get(ast_mwi_state_cache(), ast_mwi_state_type(), mwi_stasis->mailbox);
@@ -366,11 +365,7 @@ static void send_unsolicited_mwi_notify(struct mwi_subscription *sub, pjsip_evsu
 static void send_mwi_notify(struct mwi_subscription *sub, pjsip_evsub_state state, const char *reason)
 {
 	const pj_str_t *reason_str_ptr = NULL;
-	static pjsip_media_type mwi_type = {
-		.type = { "application", 11 },
-		.subtype = { "simple-message-summary", 22 },
-	};
-	struct message_accumulator counter = {
+	struct ast_sip_message_accumulator counter = {
 		.old_msgs = 0,
 		.new_msgs = 0,
 	};
@@ -378,6 +373,13 @@ static void send_mwi_notify(struct mwi_subscription *sub, pjsip_evsub_state stat
 	pjsip_tx_data *tdata;
 	pj_str_t reason_str;
 	pj_str_t pj_body;
+	const char *type = sub->is_solicited ?
+		ast_sip_subscription_get_body_type(sub->sip_sub) :
+		MWI_TYPE;
+	const char *subtype = sub->is_solicited ?
+		ast_sip_subscription_get_body_subtype(sub->sip_sub) :
+		MWI_SUBTYPE;
+	pjsip_media_type mwi_type = { { 0,}, };
 
 	ao2_callback(sub->stasis_subs, OBJ_NODATA, get_message_count, &counter);
 
@@ -385,11 +387,17 @@ static void send_mwi_notify(struct mwi_subscription *sub, pjsip_evsub_state stat
 		pj_cstr(&reason_str, reason);
 		reason_str_ptr = &reason_str;
 	}
-	ast_str_append(&body, 0, "Messages-Waiting: %s\r\n", counter.new_msgs ? "yes" : "no");
-	ast_str_append(&body, 0, "Voice-Message: %d/%d (0/0)\r\n", counter.new_msgs, counter.old_msgs);
+
+	if (ast_sip_pubsub_generate_body_content(type, subtype, &counter, &body)) {
+		ast_log(LOG_WARNING, "Unable to generate SIP MWI NOTIFY body.\n");
+		return;
+	}
+
 	pj_cstr(&pj_body, ast_str_buffer(body));
+	pj_cstr(&mwi_type.type, type);
+	pj_cstr(&mwi_type.subtype, subtype);
 
-	ast_debug(5, "Sending  %s MWI NOTIFY to endpoint %s, new messages: %d, old messages: %d\n",
+	ast_debug(5, "Sending %s MWI NOTIFY to endpoint %s, new messages: %d, old messages: %d\n",
 			sub->is_solicited ? "solicited" : "unsolicited", sub->id, counter.new_msgs,
 			counter.old_msgs);