SST: retry INV/UPD on 422 Session Interval to low

apps/conference/etc/conference.conf

@@ -50,6 +50,10 @@ playout_type=adaptive_playout
 #
 # minimum_timer=90
 
+# -  maximum Timer value we want to accept
+#
+#maximum_timer=900
+
 # session refresh (Session Timer, RFC4028) method
 #
 # INVITE                 - use re-INVITE

apps/ivr/etc/ivr.conf

@@ -18,6 +18,10 @@ script_path=/usr/local/lib/sems/ivr/
 #
 # minimum_timer=90
 
+# -  maximum Timer value we want to accept
+#
+#maximum_timer=900
+
 # session refresh (Session Timer, RFC4028) method
 #
 # INVITE                 - use re-INVITE

apps/sbc/etc/prepaid.sbcprofile.conf

@@ -58,6 +58,7 @@ prepaid_acc_dest=$H(P-Acc-Dest)
 # default values
 #session_expires=120
 #minimum_timer=90
+#maximum_timer=900
 #session_refresh_method=UPDATE_FALLBACK_INVITE
 #accept_501_reply=yes
 

apps/sbc/etc/sst_b2b.sbcprofile.conf

@@ -47,9 +47,11 @@ enable_session_timer=yes
 # default values
 #session_expires=120
 #minimum_timer=90
+#maximum_timer=900
 #session_refresh_method=UPDATE_FALLBACK_INVITE
 #accept_501_reply=yes
 
+
 #
 #This application can be routed through for achieving 
 #two things: 

apps/webconference/etc/webconference.conf

@@ -157,6 +157,10 @@ stats_dir=/var/log/sems-webconference/
 #
 # minimum_timer=90
 
+# -  maximum Timer value we want to accept
+#
+#maximum_timer=900
+
 # session refresh (Session Timer, RFC4028) method
 #
 # INVITE                 - use re-INVITE

core/AmB2BSession.cpp

@@ -387,6 +387,17 @@ bool AmB2BSession::replaceConnectionAddress(const string& content_type,
   return true;
 }
 
+void AmB2BSession::updateUACTransCSeq(unsigned int old_cseq, unsigned int new_cseq) {
+  TransMap::iterator t = relayed_req.find(old_cseq);
+  if (t != relayed_req.end()) {
+    AmSipTransaction trans = t->second;
+    relayed_req.erase(t);
+    relayed_req[new_cseq] = trans;
+    DBG("updated relayed_req (UAC trans): CSeq %u -> %u\n", old_cseq, new_cseq);
+  }
+}
+
+
 void AmB2BSession::onSipReply(const AmSipReply& reply,
 			      int old_dlg_status,
 			      const string& trans_method)
@@ -437,6 +448,7 @@ void AmB2BSession::onInvite2xx(const AmSipReply& reply)
   TransMap::iterator it = relayed_req.find(reply.cseq);
   bool req_fwded = it != relayed_req.end();
   if(!req_fwded) {
+    DBG("req not fwded\n");
     AmSession::onInvite2xx(reply);
   } else {
     DBG("no 200 ACK now: waiting for the 200 ACK from the other side...\n");

core/AmB2BSession.h

@@ -175,7 +175,10 @@ class AmB2BSession: public AmSession
   /** Terminate the other leg and forget it.*/
   virtual void terminateOtherLeg();
 
+
   /** @see AmSession */
+  virtual void updateUACTransCSeq(unsigned int old_cseq, unsigned int new_cseq);
+
   void onSipRequest(const AmSipRequest& req);
   void onSipReply(const AmSipReply& reply,
 		  int old_dlg_status, const string& trans_method);

core/AmSession.h

@@ -376,6 +376,11 @@ public:
   /** set the session on/off hold */
   virtual void setOnHold(bool hold);
 
+  /** update UAC trans state reference from old_cseq to new_cseq
+      e.g. if uac_auth or session_timer have resent a UAC request
+   */
+  virtual void updateUACTransCSeq(unsigned int old_cseq, unsigned int new_cseq) { }
+
   /**
    * Destroy the session.
    * It causes the session to be erased from the active session list

core/AmSipDialog.cpp

@@ -185,6 +185,7 @@ int AmSipDialog::rel100OnRequestIn(const AmSipRequest& req)
 		      SIP_HDR_COLSP(SIP_HDR_UNSUPPORTED) SIP_EXT_100REL CRLF,
 		      next_hop_for_replies ? next_hop_ip : "",
 		      next_hop_for_replies ? next_hop_port : 0);
+	return 0;
         break;
 
       default:

core/plug-in/echo/etc/echo.conf

@@ -16,6 +16,10 @@
 #
 # minimum_timer=90
 
+# -  maximum Timer value we want to accept
+#
+#maximum_timer=900
+
 # session refresh (Session Timer, RFC4028) method
 #
 # INVITE                 - use re-INVITE

core/plug-in/session_timer/SessionTimer.cpp

@@ -80,6 +80,52 @@ bool SessionTimer::onSipRequest(const AmSipRequest& req)
 bool SessionTimer::onSipReply(const AmSipReply& reply, int old_dlg_status,
 			      const string& trans_method)
 {
+  if (session_timer_conf.getEnableSessionTimer() &&
+      (reply.code == 422) &&
+      ((trans_method == SIP_METH_INVITE) || (trans_method == SIP_METH_UPDATE))) {
+    std::map<unsigned int, SIPRequestInfo >::iterator ri =
+      sent_requests.find(reply.cseq);
+    if (ri != sent_requests.end()) {
+      SIPRequestInfo& orig_req = ri->second;
+
+      // get Min-SE
+      unsigned int i_minse;
+      string min_se_hdr = getHeader(reply.hdrs, SIP_HDR_MIN_SE, true);
+      if (!min_se_hdr.empty()) {
+	if (str2i(strip_header_params(min_se_hdr), i_minse)) {
+	  WARN("error while parsing " SIP_HDR_MIN_SE " header value '%s'\n",
+	       strip_header_params(min_se_hdr).c_str());
+	} else {
+
+	  if (i_minse <= session_timer_conf.getMaximumTimer()) {
+	    session_interval = i_minse;
+	    unsigned int new_cseq = s->dlg.cseq;
+	    // resend request with interval i_minse
+	    if (s->dlg.sendRequest(orig_req.method,orig_req.content_type,
+				    orig_req.body, orig_req.hdrs) == 0) {
+              DBG("request with new Session Interval %u successfully sent.\n", i_minse);
+	      // undo SIP dialog status change
+	      if (s->dlg.getStatus() != old_dlg_status)
+	        s->dlg.setStatus(old_dlg_status);
+
+	      s->updateUACTransCSeq(reply.cseq, new_cseq);
+	      // processed
+	      return true;
+            } else {
+              ERROR("failed to send request with new Session Interval.\n");
+            }
+	  } else {
+	    DBG("other side requests too high Min-SE: %u (our limit %u)\n",
+		i_minse, session_timer_conf.getMaximumTimer());
+	  }
+	}
+      }
+    } else {
+      WARN("request CSeq %u not found in sent requests; unable to retry after 422\n",
+	   reply.cseq);
+    }
+  }
+
   updateTimer(s,reply);
   return false;
 }
@@ -96,10 +142,22 @@ bool SessionTimer::onSendRequest(const string& method,
     return false;
   }
 
+  if (session_timer_conf.getEnableSessionTimer() &&
+      ((method == SIP_METH_INVITE) || (method == SIP_METH_UPDATE))) {
+    // save INVITE and UPDATE so we can resend on 422 reply
+    DBG("adding %d to list of sent requests.\n", cseq);
+    sent_requests[cseq] = SIPRequestInfo(method,
+					 content_type,
+					 body,
+					 hdrs);
+  }
+
   string m_hdrs = SIP_HDR_COLSP(SIP_HDR_SUPPORTED)  "timer"  CRLF;
   if  ((method != SIP_METH_INVITE) && (method != SIP_METH_UPDATE))
     goto end;
 
+  removeHeader(hdrs, SIP_HDR_SESSION_EXPIRES);
+  removeHeader(hdrs, SIP_HDR_MIN_SE);
   m_hdrs += SIP_HDR_COLSP(SIP_HDR_SESSION_EXPIRES) + int2str(session_interval) +CRLF
     + SIP_HDR_COLSP(SIP_HDR_MIN_SE) + int2str(min_se) + CRLF;
 
@@ -372,10 +430,11 @@ void SessionTimer::onTimeoutEvent(AmTimeoutEvent* timeout_ev)
 AmSessionTimerConfig::AmSessionTimerConfig()
   : EnableSessionTimer(DEFAULT_ENABLE_SESSION_TIMER), 
     SessionExpires(SESSION_EXPIRES), 
-    MinimumTimer(MINIMUM_TIMER)
+    MinimumTimer(MINIMUM_TIMER),
+    MaximumTimer(MAXIMUM_TIMER)
 {
-
 }
+
 AmSessionTimerConfig::~AmSessionTimerConfig() 
 {
 }
@@ -405,6 +464,18 @@ int AmSessionTimerConfig::readFromConfig(AmConfigReader& cfg)
       return -1;
     }
   }
+
+  if (cfg.hasParameter("maximum_timer")){
+    int maximum_timer = 0;
+    if (!str2int(cfg.getParameter("maximum_timer"), maximum_timer) ||
+	maximum_timer<=0) {
+      ERROR("invalid value for maximum_timer '%s'\n",
+	    cfg.getParameter("maximum_timer").c_str());
+      return -1;
+    }
+    MaximumTimer = (unsigned int) maximum_timer;
+  }
+
   return 0;
 }
 

core/plug-in/session_timer/SessionTimer.h

@@ -40,11 +40,12 @@ class AmTimeoutEvent;
 #define ID_SESSION_INTERVAL_TIMER -1
 #define ID_SESSION_REFRESH_TIMER  -2
 
-/* Session Timer defaul configuration: */
+/* Session Timer default configuration: */
 #define DEFAULT_ENABLE_SESSION_TIMER 1
 #define SESSION_EXPIRES              120  // seconds
-#define MINIMUM_TIMER                90   //seconds
+#define MINIMUM_TIMER                90   // seconds
 
+#define MAXIMUM_TIMER                900   // seconds - 15 min
 
 /** \brief Factory of the session timer event handler */
 class SessionTimerFactory: public AmSessionEventHandlerFactory
@@ -71,7 +72,9 @@ class AmSessionTimerConfig
   unsigned int SessionExpires;
   /** Session Timer: Minimum Session-Expires */
   unsigned int MinimumTimer;
-    
+
+  unsigned int MaximumTimer;
+
 public:
   AmSessionTimerConfig();
   ~AmSessionTimerConfig();
@@ -90,16 +93,22 @@ public:
   bool getEnableSessionTimer() { return EnableSessionTimer; }
   unsigned int getSessionExpires() { return SessionExpires; }
   unsigned int getMinimumTimer() { return MinimumTimer; }
+  unsigned int getMaximumTimer() { return MaximumTimer; }
 
   int readFromConfig(AmConfigReader& cfg);
 };
 
+struct SIPRequestInfo;
+
 /** \brief SessionEventHandler for implementing session timer logic for a session */
 class SessionTimer: public AmSessionEventHandler
 {
   AmSessionTimerConfig session_timer_conf;
   AmSession* s;
 
+  // map to save sent requests, so we can resent in case of 422
+  std::map<unsigned int, SIPRequestInfo> sent_requests;
+
   enum SessionRefresher {
     refresh_local,
     refresh_remote
@@ -161,4 +170,22 @@ class SessionTimer: public AmSessionEventHandler
 };
 
 
+/** \brief contains necessary information for UAC auth of a SIP request */
+struct SIPRequestInfo {
+  string method;
+  string content_type;
+  string body;
+  string hdrs;
+
+  SIPRequestInfo(const string& method,
+		 const string& content_type,
+		 const string& body,
+		 const string& hdrs)
+    : method(method), content_type(content_type),
+       body(body), hdrs(hdrs) { }
+
+  SIPRequestInfo() {}
+
+};
+
 #endif