[sr-dev] git:master: modules_k/rls: made rls_handle_notify() send SIP error responses when things go wrong

[Peter Dunkley]

Module: sip-router
Branch: master
Commit: 5c61d09717c7254d42458f549e02fb59d2d52162
URL:    http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=5c61d09717c7254d42458f549e02fb59d2d52162

Author: Peter Dunkley <peter.dunkley at crocodile-rcs.com>
Committer: Peter Dunkley <peter.dunkley at crocodile-rcs.com>
Date:   Fri Feb 10 16:24:09 2012 +0000

modules_k/rls: made rls_handle_notify() send SIP error responses when things go wrong

- Currently it just silently drops the request - leaving the far end with
  stuck dialogs.
- After this change 400/481/489/500 responses are returned as appropriate.
- Also downgraded the "no presence dialog record for non-TERM.." ERR to INFO.
  This was helpful when looking for holes and race-hazards, but it can also
  occur a lot when the system is overloaded - obscuring real problems.

  For example...

	RLS			Presence
	---			--------
	SUBSCRIBE	-->
			<--	200 OK
			<--	NOTIFY
	200 OK		-->
	un-SUBSCRIBE	-->
			<--	503 (overload) - un-SUBSCRIBE not processed

	...later...

			<--	NOTIFY
	481		-->
	("no presence dialog record for...")

- With the latest updates RLS, PUA, and Presence dialogs are correctly
  removed when error responses are received (and the error responses
  are sent at the correct times).  Some of these diagnostics are no longer
  errors, or even warnings.

---

 modules_k/rls/resource_notify.c |   41 ++++++++++++++++++++++++++++++++++----
 1 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/modules_k/rls/resource_notify.c b/modules_k/rls/resource_notify.c
index 378035c..382d8d9 100644
--- a/modules_k/rls/resource_notify.c
+++ b/modules_k/rls/resource_notify.c
@@ -47,6 +47,10 @@
  * winner: sol3
  * */
 static str su_200_rpl     = str_init("OK");
+static str pu_400_rpl     = str_init("Bad Request");
+static str pu_481_rpl     = str_init("Call/Transaction Does Not Exist");
+static str pu_489_rpl     = str_init("Bad Event");
+static str pu_500_rpl     = str_init("Server Internal Error");
 
 int parse_rlsubs_did(char* str_did, str* callid, str* from_tag, str* to_tag)
 {
@@ -506,24 +510,31 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 	struct hdr_field* hdr= NULL;
 	int n, expires= -1;
 	str content_type= {0, 0};
-
+	int reply_code = 500;
+	str reply_str = pu_500_rpl;
 
 	LM_DBG("start\n");
 	/* extract the dialog information and check if an existing dialog*/	
 	if( parse_headers(msg,HDR_EOH_F, 0)==-1 )
 	{
 		LM_ERR("parsing headers\n");
-		return -1;
+		reply_code = 400;
+		reply_str = pu_400_rpl;
+		goto error;
 	}
 	if((!msg->event ) ||(msg->event->body.len<=0))
 	{
 		LM_ERR("Missing event header field value\n");
-		return -1;
+		reply_code = 400;
+		reply_str = pu_400_rpl;
+		goto error;
 	}
 	if( msg->to==NULL || msg->to->body.s==NULL)
 	{
 		LM_ERR("cannot parse TO header\n");
-		return -1;
+		reply_code = 400;
+		reply_str = pu_400_rpl;
+		goto error;
 	}
 	if(msg->to->parsed != NULL)
 	{
@@ -537,6 +548,8 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 		if(TO.uri.len <= 0) 
 		{
 			LM_ERR(" 'To' header NOT parsed\n");
+			reply_code = 400;
+			reply_str = pu_400_rpl;
 			goto error;
 		}
 		pto = &TO;
@@ -546,12 +559,16 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 	if (pto->tag_value.s==NULL || pto->tag_value.len==0 )
 	{
 		LM_ERR("to tag value not parsed\n");
+		reply_code = 400;
+		reply_str = pu_400_rpl;
 		goto error;
 	}
 	dialog.from_tag= pto->tag_value;
 	if( msg->callid==NULL || msg->callid->body.s==NULL)
 	{
 		LM_ERR("cannot parse callid header\n");
+		reply_code = 400;
+		reply_str = pu_400_rpl;
 		goto error;
 	}
 	dialog.call_id = msg->callid->body;
@@ -559,6 +576,8 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 	if (!msg->from || !msg->from->body.s)
 	{
 		LM_ERR("cannot find 'from' header!\n");
+		reply_code = 400;
+		reply_str = pu_400_rpl;
 		goto error;
 	}
 	if (msg->from->parsed == NULL)
@@ -568,6 +587,8 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 		if ( parse_from_header( msg )<0 ) 
 		{
 			LM_ERR("cannot parse From header\n");
+			reply_code = 400;
+			reply_str = pu_400_rpl;
 			goto error;
 		}
 	}
@@ -577,6 +598,8 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 	if( pfrom->tag_value.s ==NULL || pfrom->tag_value.len == 0)
 	{
 		LM_ERR("no from tag value present\n");
+		reply_code = 400;
+		reply_str = pu_400_rpl;
 		goto error;
 	}
 	dialog.to_tag= pfrom->tag_value;
@@ -586,6 +609,8 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 	if(dialog.event< 0)
 	{
 		LM_ERR("unrecognized event package\n");
+		reply_code = 489;
+		reply_str = pu_489_rpl;
 		goto error;
 	}
 
@@ -628,8 +653,10 @@ int rls_handle_notify(struct sip_msg* msg, char* c1, char* c2)
 		 */
 		if(auth_flag==TERMINATED_STATE)
 			goto done;
-		LM_ERR("no presence dialog record for non-TERMINATED state uri pres_uri = %.*s watcher_uri = %.*s\n",
+		LM_INFO("no presence dialog record for non-TERMINATED state uri pres_uri = %.*s watcher_uri = %.*s\n",
                 dialog.pres_uri->len, dialog.pres_uri->s, dialog.watcher_uri->len, dialog.watcher_uri->s);
+		reply_code = 481;
+		reply_str = pu_481_rpl;
 		goto error;
 	}
 		
@@ -784,6 +811,10 @@ done:
 	return 1;
 
 error:
+	if(slb.freply(msg, reply_code, &reply_str) < 0)
+	{
+		LM_ERR("failed sending reply\n");
+	}
 	if(res_id!=NULL)
 	{
 		pkg_free(res_id->s);