emergency: Be able to set-up an emergency call

Re-use the GSMMOCall for the emergency call setup. Add a special
route for the emergency setup as there is no number.

Start.st

@@ -11,6 +11,7 @@ Eval [
         fileIn: 'src/GSMMOCall.st';
         fileIn: 'src/GSMLURequest.st';
         fileIn: 'src/GSMCMServiceRequest.st';
+        fileIn: 'src/GSMEmergencySetup.st';
         fileIn: 'src/BSCIPAConnection.st';
         fileIn: 'src/MSC.st';
         fileIn: 'src/SIPCall.st'.

package.xml

@@ -16,6 +16,7 @@
     <filein>src/GSMCMServiceRequest.st</filein>
     <filein>src/GSMMOCall.st</filein>
     <filein>src/GSMLURequest.st</filein>
+    <filein>src/GSMEmergencySetup.st</filein>
     <filein>src/BSCIPAConnection.st</filein>
     <filein>src/MSC.st</filein>
     <filein>src/SIPCall.st</filein>

src/GSMCMServiceRequest.st

@@ -37,6 +37,21 @@ OsmoGSM.GSM48MSG extend [
     ]
 ]
 
+OsmoGSM.GSM48CCEmergencySetup extend [
+    dispatchForCMOn: aCM [
+        | call |
+        <category: '*-OsmoMSC-GSM'>
+
+        "Start the Emergency Call"
+        call := (GSMEmergencyCall on: 0 with: self ti)
+                    con: aCM con; yourself.
+        aCM con openTransaction: call with: self.
+
+        "The CMServiceRequest transaction can go away now."
+        ^ true
+    ]
+]
+
 GSMTransaction subclass: GSMCMServiceRequest [
     | timeout service state |
     <category: 'OsmoMSC-GSM'>

src/GSMEmergencySetup.st

@@ -0,0 +1,33 @@
+"
+ (C) 2012 by Holger Hans Peter Freyther
+ All Rights Reserved
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Affero General Public License as
+ published by the Free Software Foundation, either version 3 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+"
+
+GSMMOCall subclass: GSMEmergencyCall [
+    <category: 'OsmoMSC-GSM'>
+    <comment: 'I handle emergency calls'>
+
+    selectAudioRoute: aCCMessage [
+        "select route for this call, or release the call"
+        remoteLeg := con selectAudioRouteForEmergency: self.
+        remoteLeg isNil ifTrue: [
+            self logError:
+                'GSMEmergencyCall(srcref:%1) failed to select audio route.'
+                    % {con srcRef} area: #bsc.
+            self releaseComplete.
+        ].
+    ]
+]

src/GSMMOCall.st

@@ -244,9 +244,7 @@ GSMTransaction subclass: GSMMOCall [
         con removeTransaction: self.
     ]
 
-    start: aCCMessage [
-        <category: 'transaction'>
-
+    selectAudioRoute: aCCMessage [
         "select route for this call, or release the call"
         remoteLeg := con selectAudioRoute: aCCMessage calledOrDefault leg: self.
         remoteLeg isNil ifTrue: [
@@ -254,8 +252,14 @@ GSMTransaction subclass: GSMMOCall [
                 'GSMMOCall(srcref:%1) failed to select audio route.'
                     % {con srcRef} area: #bsc.
             self releaseComplete.
-            ^ self
         ].
+    ]
+
+    start: aCCMessage [
+        <category: 'transaction'>
+
+        self selectAudioRoute: aCCMessage.
+        remoteLeg isNil ifTrue: [^self].
 
         "Failed to allocate an endpoint"
         con allocateEndpoint isNil ifTrue: [

src/GSMProcessor.st

@@ -99,6 +99,11 @@ GSM transaction on a given SAPI'>
         con := aCon.
     ]
 
+    con [
+        <category: 'creation'>
+        ^ con
+    ]
+
     assignmentFailure [
         "The audio assignment has failed."
     ]
@@ -444,6 +449,12 @@ hosting various transactions and dispatching to them.'>
         ^ conManager msc mgcpCallAgent
     ]
 
+    selectAudioRouteForEmergency: aLeg [
+        <category: 'call'>
+        ^ conManager msc
+            selectAudioRouteForEmergency: self leg: aLeg.
+    ]
+
     selectAudioRoute: aPlan leg: aLeg [
         <category: 'call'>
         ^ conManager msc

src/MSC.st

@@ -245,6 +245,18 @@ Object subclass: MSCApplication [
             sip]
     ]
 
+    selectAudioRouteForEmergency: aCon leg: aLeg [
+        ^ (SIPMTCall
+            fromUser: 'sip:1000@sip.zecke.osmocom.org'
+            host: '127.0.0.1'
+            port: 5060
+            to: 'sip:911@127.0.0.1'
+            on: self sipGateway)
+            remoteLeg: aLeg;
+            yourself
+    ]
+
+
     selectAudioRoute: aCon plan: aPlan leg: aLeg [
         | nr |
         "TODO: Very simple and hardcoded rule"