#2039 P25P2 bogus talkgroup and radio values showing in calls. Corrects message length error that was causing mis-aligned mac message parsing that contained bad/errant talkgroup and radio values to be included in the call metadata. Adds support for a new Moto feature discovery that appears to be announcing talkgroup member radios that are active on/tuned to the traffic channel. (#2042)

Co-authored-by: Dennis Sheirer <[email protected]>

Author: DSheirer

src/main/java/io/github/dsheirer/module/decode/p25/phase1/P25P1DecoderState.java

@@ -188,7 +188,7 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
     private final PatchGroupManager mPatchGroupManager = new PatchGroupManager();
     private final P25P1NetworkConfigurationMonitor mNetworkConfigurationMonitor;
     private final Listener<ChannelEvent> mChannelEventListener;
-    private P25TrafficChannelManager mTrafficChannelManager;
+    private final P25TrafficChannelManager mTrafficChannelManager;
     private ServiceOptions mCurrentServiceOptions;
 
     /**

src/main/java/io/github/dsheirer/module/decode/p25/phase2/P25P2DecoderState.java

@@ -465,9 +465,16 @@ private void processMacMessage(MacMessage message)
             case PHASE1_90_GROUP_REGROUP_VOICE_CHANNEL_USER_ABBREVIATED:
                 if(mac instanceof GroupRegroupVoiceChannelUserAbbreviated gr)
                 {
-                    mPatchGroupManager.addPatchGroup(gr.getPatchgroup(), message.getTimestamp());
+                    if(gr.hasPatchgroup())
+                    {
+                        mPatchGroupManager.addPatchGroup(gr.getPatchgroup(), message.getTimestamp());
+                    }
+
+                    if(gr.hasPatchgroup() || gr.hasRadio())
+                    {
+                        processChannelUser(message, mac);
+                    }
                 }
-                processChannelUser(message, mac);
                 break;
 
             /**

src/main/java/io/github/dsheirer/module/decode/p25/phase2/message/mac/MacMessageFactory.java

@@ -129,6 +129,9 @@
 import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.l3harris.L3HarrisUnknownOpcode143;
 import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.l3harris.UnknownOpcode136;
 import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaAcknowledgeResponse;
+import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaActiveGroupRadiosOpcode130_x82;
+import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaActiveGroupRadiosOpcode143_x8F;
+import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaActiveGroupRadiosOpcode191_xBF;
 import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaDenyResponse;
 import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaGroupRegroupAddCommand;
 import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola.MotorolaGroupRegroupChannelGrantExplicit;
@@ -578,12 +581,18 @@ public static MacStructure createMacStructure(CorrectedBinaryMessage message, in
                 return new MotorolaGroupRegroupVoiceChannelUserAbbreviated(message, offset);
             case MOTOROLA_81_GROUP_REGROUP_ADD:
                 return new MotorolaGroupRegroupAddCommand(message, offset);
+            case MOTOROLA_82_ACTIVE_GROUP_RADIOS_130:
+                return new MotorolaActiveGroupRadiosOpcode130_x82(message, offset);
             case MOTOROLA_83_GROUP_REGROUP_VOICE_CHANNEL_UPDATE:
                 return new MotorolaGroupRegroupVoiceChannelUpdate(message, offset);
             case MOTOROLA_84_GROUP_REGROUP_EXTENDED_FUNCTION_COMMAND:
                 return new MotorolaGroupRegroupExtendedFunctionCommand(message, offset);
             case MOTOROLA_89_GROUP_REGROUP_DELETE:
                 return new MotorolaGroupRegroupDeleteCommand(message, offset);
+            case MOTOROLA_8F_ACTIVE_GROUP_RADIOS_143:
+                return new MotorolaActiveGroupRadiosOpcode143_x8F(message, offset);
+            case MOTOROLA_BF_ACTIVE_GROUP_RADIOS_191:
+                return new MotorolaActiveGroupRadiosOpcode191_xBF(message, offset);
             case MOTOROLA_91_TALKER_ALIAS_HEADER:
                 return new MotorolaTalkerAliasHeader(message, offset);
             case MOTOROLA_95_TALKER_ALIAS_DATA_BLOCK:

src/main/java/io/github/dsheirer/module/decode/p25/phase2/message/mac/MacOpcode.java

@@ -115,12 +115,15 @@ public enum MacOpcode
 
     MOTOROLA_80_GROUP_REGROUP_VOICE_CHANNEL_USER_ABBREVIATED(Vendor.MOTOROLA, 128, "MOTOROLA GROUP REGROUP VOICE CHANNEL USER ABBREVIATED", 8),
     MOTOROLA_81_GROUP_REGROUP_ADD(Vendor.MOTOROLA, 129, "MOTOROLA GROUP REGROUP ADD", 17),
-    MOTOROLA_83_GROUP_REGROUP_VOICE_CHANNEL_UPDATE(Vendor.MOTOROLA, 131, "MOTOROLA INDIVIDUAL REGROUP ACTIVE", 8),
+    MOTOROLA_82_ACTIVE_GROUP_RADIOS_130(Vendor.MOTOROLA, 130, "MOTOROLA ACTIVE GROUP RADIOS 130", Integer.MIN_VALUE),
+    MOTOROLA_83_GROUP_REGROUP_VOICE_CHANNEL_UPDATE(Vendor.MOTOROLA, 131, "MOTOROLA INDIVIDUAL REGROUP ACTIVE", 7),
     MOTOROLA_84_GROUP_REGROUP_EXTENDED_FUNCTION_COMMAND(Vendor.MOTOROLA, 133, "MOTOROLA GROUP REGROUP", 11),
     MOTOROLA_89_GROUP_REGROUP_DELETE(Vendor.MOTOROLA, 137, "MOTOROLA GROUP REGROUP DELETE", 17),
+    MOTOROLA_8F_ACTIVE_GROUP_RADIOS_143(Vendor.MOTOROLA, 143, "MOTOROLA ACTIVE GROUP RADIOS 143", Integer.MIN_VALUE),
+    MOTOROLA_BF_ACTIVE_GROUP_RADIOS_191(Vendor.MOTOROLA, 191, "MOTOROLA ACTIVE GROUP RADIOS 191", Integer.MIN_VALUE),
     //Opcode 144 uses STANDARD vendor ID for some reason.
-    MOTOROLA_91_TALKER_ALIAS_HEADER(Vendor.MOTOROLA, 145, "MOTOROLA GROUP REGROUP UNKNOWN", 17),
-    MOTOROLA_95_TALKER_ALIAS_DATA_BLOCK(Vendor.MOTOROLA, 149, "MOTOROLA UNKNOWN 149", 17),
+    MOTOROLA_91_TALKER_ALIAS_HEADER(Vendor.MOTOROLA, 145, "MOTOROLA TALKER ALIAS HEADER", 17),
+    MOTOROLA_95_TALKER_ALIAS_DATA_BLOCK(Vendor.MOTOROLA, 149, "MOTOROLA TALKER ALIAS DATA BLOCK", 17),
     MOTOROLA_A0_GROUP_REGROUP_VOICE_CHANNEL_USER_EXTENDED(Vendor.MOTOROLA, 160, "MOTOROLA GROUP REGROUP VOICE CHANNEL USER EXTENDED", 16),
     MOTOROLA_A3_GROUP_REGROUP_CHANNEL_GRANT_IMPLICIT(Vendor.MOTOROLA, 163, "MOTOROLA GROUP REGROUP CHANNEL GRANT IMPLICIT", 11),
     MOTOROLA_A4_GROUP_REGROUP_CHANNEL_GRANT_EXPLICIT(Vendor.MOTOROLA, 164, "MOTOROLA GROUP REGROUP CHANNEL GRANT EXPLICIT", 13),

src/main/java/io/github/dsheirer/module/decode/p25/phase2/message/mac/structure/GroupRegroupVoiceChannelUserAbbreviated.java

@@ -29,7 +29,6 @@
 import io.github.dsheirer.module.decode.p25.identifier.radio.APCO25RadioIdentifier;
 import io.github.dsheirer.module.decode.p25.reference.ServiceOptions;
 import io.github.dsheirer.module.decode.p25.reference.VoiceServiceOptions;
-
 import java.util.ArrayList;
 import java.util.List;
 
@@ -64,11 +63,7 @@ public String toString()
         StringBuilder sb = new StringBuilder();
         sb.append("GROUP REGROUP VOICE CHANNEL USER ABBREVIATED");
         sb.append(" TALKGROUP:").append(getPatchgroup());
-        if(hasRadio())
-        {
-            sb.append(" TALKER RADIO:").append(getRadio());
-        }
-
+        sb.append(" TALKER RADIO:").append(getRadio());
         return sb.toString();
     }
 
@@ -91,6 +86,14 @@ public PatchGroupIdentifier getPatchgroup()
         return mPatchgroup;
     }
 
+    /**
+     * Indicates if this message has a non-zero patch group identifier.
+     */
+    public boolean hasPatchgroup()
+    {
+        return getInt(SUPERGROUP) > 0;
+    }
+
     /**
      * Talker radio identifier.
      */
@@ -118,7 +121,11 @@ public List<Identifier> getIdentifiers()
         if(mIdentifiers == null)
         {
             mIdentifiers = new ArrayList<>();
-            mIdentifiers.add(getPatchgroup());
+
+            if(hasPatchgroup())
+            {
+                mIdentifiers.add(getPatchgroup());
+            }
 
             if(hasRadio())
             {

src/main/java/io/github/dsheirer/module/decode/p25/phase2/message/mac/structure/motorola/MotorolaActiveGroupRadiosOpcode130_x82.java

@@ -0,0 +1,211 @@
+/*
+ * *****************************************************************************
+ * Copyright (C) 2014-2024 Dennis Sheirer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * ****************************************************************************
+ */
+
+package io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.motorola;
+
+import io.github.dsheirer.bits.CorrectedBinaryMessage;
+import io.github.dsheirer.bits.IntField;
+import io.github.dsheirer.identifier.Identifier;
+import io.github.dsheirer.identifier.radio.RadioIdentifier;
+import io.github.dsheirer.module.decode.p25.identifier.radio.APCO25RadioIdentifier;
+import io.github.dsheirer.module.decode.p25.phase2.message.mac.structure.MacStructureVendor;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Motorola Group Radios Active Feature.  Observed on NM-DTRS Phase 2 network.  My theory is that this lists the
+ * subset of talkgroup member radios that are currently active on the traffic channel.
+ *
+ * Opcodes 130 and 143 are almost the same, except 143 is mostly transmitted during an ACTIVE call state and 130 is
+ * mostly transmitted during the HANGTIME state.  I say mostly, because there are examples where both opcodes are seen
+ * in both channel states.
+ *
+ * Curiously: opcode 130 is in the middle of the message number sequence where GROUP REGROUP messages are allocated.
+ *
+ * Opcode 143 includes an additional 1-byte status field that seems to contain a 2-bit sequence counter that mostly
+ * cycles through all values, but sometimes it skips values or just toggles between two of the observed values.
+ * Examples: 0x00, 0x40, 0x80, 0xC0
+ * There doesn't seem to be any correlation between the value of this nibble and the radio IDs being transmitted.
+ *
+ * The lower nibble of this 1-byte field seems to have an additional flag bit that is sometimes transmitted:
+ * Examples: 0x08, 0x88
+ *
+ * Both opcode 130 and 143 employ up to 2x 1-byte fields that always transmit a 0x09 value.  The second field is only
+ * present when the message is sending 3 or 4 radio IDs.
+ *
+ * It seems that the complete list of active member radios is transmitted in a fixed sequence with zero to four of those
+ * radios transmitted per message.  The messages are transmitted when the talkgroup is first allocated to the channel
+ * and eventually the 130/143 messages stop listing radios and the empty 143 and the 191 messages are intermittently
+ * sent.  Occasionally there are radios listed in the message with all zeros values.
+ *
+ * Opcode 143 is transmitted with just the status byte and no radio IDs after the full sequence of radios has been
+ * sent and are no longer being sent.
+ *
+ * I'm not sure what Opcode 191 indicates.  It's always the same (3-bytes) value: BF9003.  It may be some kind of
+ * feature marker to let the listening radios/devices know that the feature is active on that traffic channel.
+ *
+ * These three opcodes seem to be used for this feature.
+ * Opcode 130/x82 - talkgroup member radios currently active - mostly transmitted during HANGTIME
+ * Opcode 143/x8F - talkgroup member radios currently active - mostly transmitted during ACTIVE call state
+ * Opcode 191/xBF - transmitted continuously while channel is allocated to a talkgroup - fixed value: 0xBF9003
+ */
+public class MotorolaActiveGroupRadiosOpcode130_x82 extends MacStructureVendor
+{
+    private static final IntField SEPARATOR_1 = IntField.length8(OCTET_4_BIT_24); //Value is always 0x09
+    private static final IntField RADIO_1 = IntField.length24(OCTET_5_BIT_32);
+    private static final IntField RADIO_2 = IntField.length24(OCTET_8_BIT_56);
+    private static final IntField SEPARATOR_2 = IntField.length8(OCTET_11_BIT_80); //Value is always 0x09
+    private static final IntField RADIO_3 = IntField.length24(OCTET_12_BIT_88);
+    private static final IntField RADIO_4 = IntField.length24(OCTET_15_BIT_112);
+    private RadioIdentifier mRadio1;
+    private RadioIdentifier mRadio2;
+    private RadioIdentifier mRadio3;
+    private RadioIdentifier mRadio4;
+
+    /**
+     * Constructs the message
+     *
+     * @param message containing the message bits
+     * @param offset into the message for this structure
+     */
+    public MotorolaActiveGroupRadiosOpcode130_x82(CorrectedBinaryMessage message, int offset)
+    {
+        super(message, offset);
+    }
+
+    /**
+     * Textual representation of this message
+     */
+    public String toString()
+    {
+        StringBuilder sb = new StringBuilder();
+        sb.append("MOTOROLA 130 ACTIVE GROUP RADIOS: ");
+        sb.append(getRadio1());
+
+        if(hasRadio2())
+        {
+            sb.append(", ").append(getRadio2());
+
+            if(hasRadio3())
+            {
+                sb.append(", ").append(getRadio3());
+
+                if(hasRadio4())
+                {
+                    sb.append(", ").append(getRadio4());
+                }
+            }
+        }
+
+        CorrectedBinaryMessage cbm = getMessage().getSubMessage(getOffset(), getOffset() + (getLength() * 8));
+        sb.append(" MSG:").append(cbm.toHexString());
+
+        return sb.toString();
+    }
+
+    /**
+     * Radio identifier or null if the message doesn't contain the value.
+     */
+    public RadioIdentifier getRadio1()
+    {
+        if(mRadio1 == null && hasRadio1())
+        {
+            mRadio1 = APCO25RadioIdentifier.createAny(getInt(RADIO_1));
+        }
+
+        return mRadio1;
+    }
+
+    /**
+     * Radio identifier or null if the message doesn't contain the value.
+     */
+    public RadioIdentifier getRadio2()
+    {
+        if(mRadio2 == null && hasRadio2())
+        {
+            mRadio2 = APCO25RadioIdentifier.createAny(getInt(RADIO_2));
+        }
+
+        return mRadio2;
+    }
+
+    /**
+     * Radio identifier or null if the message doesn't contain the value.
+     */
+    public RadioIdentifier getRadio3()
+    {
+        if(mRadio3 == null && hasRadio3())
+        {
+            mRadio3 = APCO25RadioIdentifier.createAny(getInt(RADIO_3));
+        }
+
+        return mRadio3;
+    }
+
+    /**
+     * Radio identifier or null if the message doesn't contain the value.
+     */
+    public RadioIdentifier getRadio4()
+    {
+        if(mRadio4 == null && hasRadio4())
+        {
+            mRadio4 = APCO25RadioIdentifier.createAny(getInt(RADIO_4));
+        }
+
+        return mRadio4;
+    }
+
+    /**
+     * Indicates if this message contains the radio value.
+     */
+    public boolean hasRadio1()
+    {
+        return getLength() > 4;
+    }
+
+    /**
+     * Indicates if this message contains the radio value.
+     */
+    public boolean hasRadio2()
+    {
+        return getLength() > 8;
+    }
+
+    /**
+     * Indicates if this message contains the radio value.
+     */
+    public boolean hasRadio3()
+    {
+        return getLength() > 11;
+    }
+
+    /**
+     * Indicates if this message contains the radio value.
+     */
+    public boolean hasRadio4()
+    {
+        return getLength() > 15;
+    }
+
+    @Override
+    public List<Identifier> getIdentifiers()
+    {
+        return Collections.emptyList();
+    }
+}