sccp: Attempt to add timeout handling to the SCCP Connection.

Rename SCCPConnectionBase to SCCPConnectionState and subclass
to add timer handling on top of the State. The IT sending is
not implemented properly yet.

1 files changed, 147 insertions, 15 deletions

diff --git a/SCCPHandler.st b/SCCPHandler.st
index 6f57f63..4bba152 100644
--- a/SCCPHandler.st
+++ b/SCCPHandler.st
@@ -16,24 +16,26 @@
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 "
 
-PackageLoader fileInPackage: 'OsmoNetwork'.
+PackageLoader
+    fileInPackage: 'OsmoCore';
+    fileInPackage: 'OsmoNetwork'.
 
-Object subclass: SCCPConnectionBase [
+Object subclass: SCCPConnectionState [
     | src dst conManager confirmSem proc state sem |
 
-    SCCPConnectionBase class >> stateInitial   [ <category: 'state'> ^ 0 ]
-    SCCPConnectionBase class >> stateRequested [ <category: 'state'> ^ 1 ]
-    SCCPConnectionBase class >> stateConnected [ <category: 'state'> ^ 2 ]
-    SCCPConnectionBase class >> stateReleased  [ <category: 'state'> ^ 3 ]
-    SCCPConnectionBase class >> stateReleaseComplete  [ <category: 'state'> ^ 4 ]
-    SCCPConnectionBase class >> stateTimeout   [ <category: 'state'> ^ 5 ]
+    SCCPConnectionState class >> stateInitial   [ <category: 'state'> ^ 0 ]
+    SCCPConnectionState class >> stateRequested [ <category: 'state'> ^ 1 ]
+    SCCPConnectionState class >> stateConnected [ <category: 'state'> ^ 2 ]
+    SCCPConnectionState class >> stateReleased  [ <category: 'state'> ^ 3 ]
+    SCCPConnectionState class >> stateReleaseComplete  [ <category: 'state'> ^ 4 ]
+    SCCPConnectionState class >> stateTimeout   [ <category: 'state'> ^ 5 ]
 
-    SCCPConnectionBase class >> new [
+    SCCPConnectionState class >> new [
         <category: 'creation'>
         ^ self shouldNotImplement
     ]
 
-    SCCPConnectionBase class >> on: aHandler [
+    SCCPConnectionState class >> on: aHandler [
         <category: 'creation'>
         ^ super new
             initialize;
@@ -92,7 +94,7 @@ Object subclass: SCCPConnectionBase [
     changeState: newState do: aBlock [
         sem critical: [
             state := newState.
-            aBlock value
+            aBlock value.
         ]
     ]
 
@@ -102,6 +104,7 @@ Object subclass: SCCPConnectionBase [
         "Send the confirmation now"
 
         self changeState: self class stateRequested do: [
+            self startConnEstTimer.
             res := Osmo.SCCPConnectionRequest
                 initWith: (self srcRef) dest: (Osmo.SCCPAddress createWith: 254) data: aData.
             self nextPut: res toMessage.
@@ -113,6 +116,7 @@ Object subclass: SCCPConnectionBase [
 
         self changeState: self class stateConnected do: [
             self dstRef: aCC src.
+            self startConfirmTimer.
             confirmSem signal.
         ]
     ]
@@ -122,6 +126,7 @@ Object subclass: SCCPConnectionBase [
         <category: 'handling'>
 
         self changeState: self class stateReleased do: [
+            self startReleaseTimer.
             rlsd := Osmo.SCCPConnectionReleased initWithDst: self dstRef src: self srcRef cause: 0.
             self nextPut: rlsd toMessage.
         ]
@@ -132,7 +137,7 @@ Object subclass: SCCPConnectionBase [
         "TODO: verify that we are in the right state"
 
         self changeState: self class stateReleaseComplete do: [
-            self terminate.
+            self finish.
         ]
     ]
 
@@ -145,7 +150,7 @@ Object subclass: SCCPConnectionBase [
             rlc := Osmo.SCCPConnectionReleaseComplete
                         initWithDst: aRLSD src src: aRLSD dst.
             self nextPut: rlc toMessage.
-            self terminate.
+            self finish.
         ]
     ]
 
@@ -162,6 +167,126 @@ Object subclass: SCCPConnectionBase [
     ]
 ]
 
+SCCPConnectionState subclass: SCCPConnectionBase [
+    | t_conn_est t_ias t_iar t_rel t_repeat_rel t_int |
+    <category: 'OSMO-SCCP'>
+    <comment: 'I add timeout handling based on the SCCP Connection State.
+My timeout values can be seen in ITU Q.714 Annex C.4'>
+
+    SCCPConnectionBase class [
+        tconnEstTime [  <category: 'timeouts'> ^ 60 ]
+        tiasTime [ <category: 'timeouts'> ^ 5 * 60 ]
+        tiarTime [ <category: 'timeouts'> ^ 15 * 60 ]
+        trelTime [ <category: 'timeouts'> ^ 15 ]
+        trepeatRelTime [ <category: 'timeouts'> ^ 15 ]
+        tintTime [ <category: 'timeouts'> ^ 60 ]
+    ]
+
+    stopAllTimers [
+        <category: 'private'>
+
+        sem critical: [
+            t_conn_est ifNotNil: [t_conn_est cancel].
+            t_ias ifNotNil: [t_ias cancel].
+            t_iar ifNotNil: [t_iar cancel].
+            t_rel ifNotNil: [t_rel cancel].
+            t_repeat_rel ifNotNil: [t_repeat_rel cancel]
+        ]
+    ]
+
+    finish [
+        <category: 'wrap up'>
+
+        self
+            stopAllTimers;
+            terminate.
+    ]
+
+    schedule: aTime block: aBlock [
+        "I make sure that the SCCPConnManager and SCCPCon locks are held"
+        <category: 'private'>
+
+        ^ Osmo.TimerScheduler instance
+                scheduleInSeconds: aTime block: [
+                    conManager critical: [sem critical: [aBlock value]]].
+    ]
+
+    startConnEstTimer [
+        <category: 'conn-establishment'>
+        self stopAllTimers.
+        t_conn_est := self schedule: self class tconnEstTime block: [self conTimeout].
+    ]
+
+    conTimeout [
+        <category: 'conn-establishment'>
+        conManager connectionTimeout: self.
+    ]
+
+    startConfirmTimer [
+        <category: 'confirm-timer'>
+        t_conn_est ifNotNil: [t_conn_est cancel. t_conn_est := nil].
+
+        self startTias.
+        self startTiar.
+    ]
+
+    startTias [
+        <category: 'confirm-timer'>
+        t_ias ifNotNil: [t_ias cancel. t_ias := nil].
+        t_ias := self schedule: self class tiasTime block: [self sendInactivty].
+    ]
+
+    startTiar [
+        <category: 'confirm-timer'>
+        t_iar := self schedule: self class tiarTime block: [self sendRelease].
+    ]
+
+    sendInactivty [
+        <category: 'confirm-timer'>
+        self logError: 'IT sending is not implemented.' area: #sccp.
+    ]
+
+    sendRelease [
+        <category: 'confirm-timer'>
+        self logError: 'Releasing connection due inactivity.' area: #sccp.
+        self release.
+    ]
+
+    startReleaseTimer [
+        "We might be called multiple times and we use some variables to
+         figure out if we are the one or the other."
+        <category: 'release-timer'>
+
+        t_ias ifNotNil: [t_ias cancel].
+        t_iar ifNotNil: [t_iar cancel].
+
+        t_rel isNil
+            ifTrue: [
+                t_rel := self schedule: self class trelTime block: [self releaseTimeout]]
+            ifFalse: [
+                self startReleaseRepeatTimer.].
+    ]
+
+    releaseTimeout [
+        <category: 'release-timer'>
+        self logError: 'Release timeout.' area: #sccp.
+        t_int := self schedule: self class tintTime block: [self forceRelease].
+        self release.
+    ]
+
+    startReleaseRepeatTimer [
+        <category: 'release-timer'>
+        t_repeat_rel ifNotNil: [t_repeat_rel cancel. t_repeat_rel := nil].
+        t_repeat_rel := self schedule: self class trepeatRelTime block: [self release].
+    ]
+
+    forceRelease [
+        <category: 'release-timer'>
+        conManager addToFreezeList: self.
+        conManager connectionTimeout: self.
+    ]
+]
+
 SCCPConnectionBase subclass: SCCPConnection [
     data: aDT [
         "nothing implemented"
@@ -364,9 +489,16 @@ deadlocks should not occur.'>
         self connections remove: aConnection.
     ]
 
+    addToFreezeList: aConnection [
+        <category: 'private'>
+        "TODO: Implement the freeze list so some SCCP SRCREF will not be
+        assigned for a given time."
+    ]
+
     connectionTimeout: aConnection [
         <category: 'private'>
         self logError: 'SCCP Connection %1 timedout' % {aConnection srcRef} area: #sccp.
+        self doTerminate: aConnection.
         self removeConnection: aConnection.
     ]
 
@@ -451,9 +583,9 @@ deadlocks should not occur.'>
         "I kill the SCCP Connection."
 
         [
-            aCon terminate
+            aCon finish.
         ] on: Error do: [:each |
-            each logException: 'Failed to terminate %1' % {aCon srcRef} area: #sccp.
+            each logException: 'Failed to finish %1' % {aCon srcRef} area: #sccp.
         ]
     ]
 ]