presence: add a offset for allowed cseq difference

src/modules/presence/presence.c

@@ -142,6 +142,7 @@ char prefix='a';
 int startup_time=0;
 str db_url = {0, 0};
 int expires_offset = 0;
+int pres_cseq_offset = 0;
 uint32_t min_expires= 0;
 int min_expires_action= 1;
 uint32_t max_expires= 3600;
@@ -226,6 +227,7 @@ static param_export_t params[]={
 	{ "retrieve_order",         PARAM_INT, &pres_retrieve_order},
 	{ "retrieve_order_by",      PARAM_STR, &pres_retrieve_order_by},
 	{ "sip_uri_match",          PARAM_INT, &pres_uri_match},
+    { "cseq_offset",            PARAM_INT, &pres_cseq_offset},
 	{0,0,0}
 };
 

src/modules/presence/presence.h

@@ -71,6 +71,7 @@ extern int pid;
 extern int startup_time;
 extern char *to_tag_pref;
 extern int expires_offset;
+extern int pres_cseq_offset;
 extern str server_address;
 extern uint32_t min_expires;
 extern int min_expires_action;

src/modules/presence/subscribe.c

@@ -1666,7 +1666,7 @@ found_rec:
 
 	subs->local_cseq= s->local_cseq +1;
 
-	if(subs->remote_cseq<= s->remote_cseq)
+	if(subs->remote_cseq + pres_cseq_offset <= s->remote_cseq)
 	{
 		LM_ERR("wrong sequence number;received: %d - stored: %d\n",
 				subs->remote_cseq, s->remote_cseq);
@@ -1782,7 +1782,7 @@ int get_database_info(struct sip_msg* msg, subs_t* subs, int* reply_code, str* r
 	row_vals = ROW_VALUES(row);
 	remote_cseq= row_vals[remote_cseq_col].val.int_val;
 
-	if(subs->remote_cseq<= remote_cseq)
+	if(subs->remote_cseq + pres_cseq_offset <= remote_cseq)
 	{
 		LM_ERR("wrong sequence number received: %d - stored: %d\n",
 				subs->remote_cseq, remote_cseq);