Bearer capability not provided during MO call using mncc-python, which results in GSM IE error (96) invalid mandatory information sent by Network -> MS (mncc-python)

Verified this error by GSMTAP using mncc-python interface OsmocomBB to network
Proposed Changes:
In case of MO call (_onmncc_setup_req) caller needs to provide bearer_cap speech version
Added mncc.bearer_cap in mncc_sock.py based on codecs = GSM48.AllCodecs
Added new field mncc.MNCC_F_BEARER_CAP in mncc.MNCC_SETUP_REQ, when call is initiated (MO) from MS -> network

Change-Id: If77851b86111d62d82221a886ed2391179080cca

gsm_call_fsm.py

@@ -14,7 +14,7 @@ import ctypes
 import pykka
 
 from fysom import Fysom
-from mncc_sock import mncc_msg, mncc_number, mncc_rtp_msg, mncc_bridge_msg
+from mncc_sock import mncc_msg, mncc_number, mncc_rtp_msg, mncc_bridge_msg, mncc_bearer_cap
 
 Uint32Array2 = mncc.uint32_t * 2
 
@@ -82,9 +82,10 @@ class GsmCallFsm(pykka.ThreadingActor):
 
     def _onmncc_setup_req(self, e):
         msg = mncc_msg(msg_type = mncc.MNCC_SETUP_REQ, callref = self.callref,
-                       fields = mncc.MNCC_F_CALLED | mncc.MNCC_F_CALLING,
+                       fields = mncc.MNCC_F_CALLED | mncc.MNCC_F_CALLING | mncc.MNCC_F_BEARER_CAP,
                        calling = mncc_number(self.calling),
-                       called = mncc_number(self.called))
+                       called = mncc_number(self.called),
+                       bearer_cap = mncc_bearer_cap(self.codecs_permitted))
         self.mncc_ref.tell({'type': 'send', 'msg': msg})
 
     def find_matching_codec(self, ms_codecs):

mncc_sock.py

@@ -52,6 +52,18 @@ def mncc_number(number, num_type = 0, num_plan = 0, num_present = 1, num_screen
                                 plan = num_plan, present = num_present,
                                 screen = num_screen)
 
+def mncc_bearer_cap(codecs_permitted):
+    speech_ver = ctypes.c_int * 8
+    speech_types = speech_ver()
+    index = 0
+
+    for codec in codecs_permitted:
+        speech_types[index] = codec
+        index = index + 1
+
+    speech_types[index] = -1
+    return mncc.gsm_mncc_bearer_cap(coding = 0, speech_ctm=0, radio = 1, speech_ver = speech_types, transfer = 0, mode = 0)
+
 class MnccSocketBase(object):
     def send(self, msg):
         return self.sock.sendall(msg.send())