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Improve Templated "find & replace" algorithm for IPSC packets

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This DECREASES the risk of a false positive replacing TGID and
Subscriber ID by 16,581,375 times.
This commit is contained in:
Cort Buffington 2018-03-13 08:25:13 -05:00
parent dccbe86fd3
commit 1e1a88fff0
2 changed files with 8 additions and 6 deletions
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14
dmr_utils/ambe_bridge.py
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@ -572,7 +572,7 @@ class AMBE_IPSC(AMBE_BASE):
def send_voice_term(self, _rx_slot): def send_voice_term(self, _rx_slot):
self.rewriteFrame(self._tempTerm, _rx_slot.slot, _rx_slot.dst_id, _rx_slot.rf_src, _rx_slot.repeater_id) self.rewriteFrame(self._tempTerm, _rx_slot.slot, _rx_slot.dst_id, _rx_slot.rf_src, _rx_slot.repeater_id)
pass pass
def rewriteFrame( self, _frame, _newSlot, _newGroup, _newSouceID, _newPeerID ): def rewriteFrame( self, _frame, _newSlot, _newGroup, _newSourceID, _newPeerID ):
_peerid = _frame[1:5] # int32 peer who is sending us a packet _peerid = _frame[1:5] # int32 peer who is sending us a packet
_src_sub = _frame[6:9] # int32 Id of source _src_sub = _frame[6:9] # int32 Id of source
@ -581,11 +581,13 @@ class AMBE_IPSC(AMBE_BASE):
######################################################################## ########################################################################
# re-Write the peer radio ID to that of this program # re-Write the peer radio ID to that of this program
_frame = _frame.replace(_peerid, _newPeerID) _frame = _frame.replace(_peerid, _newPeerID, 1)
# re-Write the source subscriber ID to that of this program # re-Write the source subscriber ID + destination Group ID combo in the IPSC Header
_frame = _frame.replace(_src_sub, _newSouceID) _frame = _frame.replace(_src_sub + _group, _newSourceID + _newGroup, 1)
# Re-Write the destination Group ID # Re-Write the destination Group ID + source subscriber ID combo in the decoded LCs
_frame = _frame.replace(_group, _newGroup) _frame = _frame.replace(_group + _src_sub, _newGroup + _newSourceID, 1)
_frame = _frame[:5] + struct.pack("i", self.ipsc_seq)[0] + _frame[6:] # ipsc sequence number increments on each transmission (stream id) _frame = _frame[:5] + struct.pack("i", self.ipsc_seq)[0] + _frame[6:] # ipsc sequence number increments on each transmission (stream id)
# Re-Write IPSC timeslot value # Re-Write IPSC timeslot value

0
dmr_utils/ambe_utils.py Normal file → Executable file
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