add option to disable deny responses in conventional for radios that are braindead and interpret an OSP_DENY as a ISP_EMERG because of opcode reuse (thanks TIA-102);

configs/config.example.yml

@@ -295,6 +295,11 @@ protocols:
         unitToUnitAvailCheck: false
         # Flag indicating explicit source ID support is enabled.
         allowExplicitSourceId: false
+        # Flag indicating whether or not the host will disable sending deny responses when operating in conventional.
+        #   (Some subscriber radios do not handle deny responses in conventional, and rather interpret them as
+        #   a emergency call trigger, this option allows the deny response to be disabled to prevent errant emergency
+        #   call triggers.)
+        disableDenyResponse: false
         # Flag indicating whether or not the host will respond to SNDCP data requests.
         sndcpSupport: false
         # BER/Error threshold for silencing voice packets. (0 or 1233 disables)

src/host/p25/Control.cpp

@@ -87,6 +87,7 @@ Control::Control(bool authoritative, uint32_t nac, uint32_t callHang, uint32_t q
     m_forceAllowTG0(false),
     m_immediateCallTerm(true),
     m_explicitTDUGrantRelease(true),
+    m_disableDenyResponse(false),
     m_defaultNetIdleTalkgroup(0U),
     m_idenTable(idenTable),
     m_ridLookup(ridLookup),
@@ -371,6 +372,7 @@ void Control::setOptions(yaml::Node& conf, bool supervisor, const std::string cw
 
     m_immediateCallTerm = p25Protocol["immediateCallTerm"].as<bool>(true);
     m_explicitTDUGrantRelease = p25Protocol["explicitTDUGrantRelease"].as<bool>(true);
+    m_disableDenyResponse = p25Protocol["disableDenyResponse"].as<bool>(false);
 
     /*
     ** Voice Silence and Frame Loss Thresholds

src/host/p25/Control.h

@@ -318,6 +318,7 @@ namespace p25
         bool m_forceAllowTG0;
         bool m_immediateCallTerm;
         bool m_explicitTDUGrantRelease;
+        bool m_disableDenyResponse;
 
         uint32_t m_defaultNetIdleTalkgroup;
 

src/host/p25/packet/ControlSignaling.cpp

@@ -2780,6 +2780,13 @@ void ControlSignaling::writeRF_TSDU_Deny(uint32_t srcId, uint32_t dstId, uint8_t
             osp->getSrcId(), osp->getDstId());
     }
 
+    // are deny responses disabled?
+    if (!m_p25->m_dedicatedControl && !m_p25->m_controlOnly && m_p25->m_disableDenyResponse) {
+        // at least ACK the request to try to silence the sender
+        writeRF_TSDU_ACK_FNE(srcId, service, aiv, false);
+        return;
+    }
+
     writeRF_TSDU_SBF_Imm(osp.get(), false);
 }