implemented options_session_limit: SEMS-31 Special OPTIONS response if near session_limit

git-svn-id: http://svn.berlios.de/svnroot/repos/sems/trunk@1506 8eb893ce-cfd4-0310-b710-fb5ebe64c474

core/AmConfig.cpp

@@ -70,6 +70,10 @@ unsigned int AmConfig::SessionLimit            = 0;
 unsigned int AmConfig::SessionLimitErrCode     = 503;
 string       AmConfig::SessionLimitErrReason   = "Server overload";
 
+unsigned int AmConfig::OptionsSessionLimit            = 0;
+unsigned int AmConfig::OptionsSessionLimitErrCode     = 503;
+string       AmConfig::OptionsSessionLimitErrReason   = "Server overload";
+
 vector <string> AmConfig::CodecOrder;
 
 Dtmf::InbandDetectorType 
@@ -368,6 +372,18 @@ int AmConfig::readConfiguration()
     }
   }
 
+  if(cfg.hasParameter("options_session_limit")){ 
+    vector<string> limit = explode(cfg.getParameter("options_session_limit"), ";");
+    if (limit.size() != 3) {
+      ERROR("invalid options_session_limit specified.\n");
+    } else {
+      if (str2i(limit[0], OptionsSessionLimit) || str2i(limit[1], OptionsSessionLimitErrCode)) {
+	ERROR("invalid options_session_limit specified.\n");
+      }
+      OptionsSessionLimitErrReason = limit[2];
+    }
+  }
+
   return 0;
 }	
 

core/AmConfig.h

@@ -110,6 +110,10 @@ struct AmConfig
   static unsigned int SessionLimitErrCode;
   static string SessionLimitErrReason;
 
+  static unsigned int OptionsSessionLimit;
+  static unsigned int OptionsSessionLimitErrCode;
+  static string OptionsSessionLimitErrReason;
+
   /** Time of no RTP after which Session is regarded as dead, 0 for no Timeout */
   static unsigned int DeadRtpTime;
 

core/AmSipDispatcher.cpp

@@ -92,7 +92,15 @@ void AmSipDispatcher::handleSipMsg(AmSipRequest &req)
   else if(req.method == "OPTIONS"){
       
       // Basic OPTIONS support
-      AmSipDialog::reply_error(req,200,"OK");
+    if (!AmConfig::OptionsSessionLimit || 
+	(AmSession::getSessionNum() < AmConfig::OptionsSessionLimit)) {
+      AmSipDialog::reply_error(req, 200, "OK");
+    } else {
+      // return error code if near to overload
+      AmSipDialog::reply_error(req,
+			       AmConfig::OptionsSessionLimitErrCode, 
+			       AmConfig::OptionsSessionLimitErrReason);
+    }
       return;
 
   } else if( (req.method == "CANCEL") || 

core/etc/sems.conf.sample

@@ -244,6 +244,18 @@ loglevel=2
 # Example:
 #  session_limit="1000;503;Server overload"
 
+# optional parameter: options_session_limit=<limit>;<err code>;<err reason>
+# 
+# - this sets a custom response to OPTIONS, if the session count reaches
+#   a certain limit. This way health monitor could raise an alarm to syste
+#   administrator. 
+# 
+# Default: 0 (None)
+#
+# Example:
+#  options_session_limit="900;503;Warning, server soon overloaded"
+
+
 # optional parameter: dead_rtp_time=<unsigned int>
 #
 # - if != 0, after this time (in seconds) of no RTP