add support to transmit LC_FAILSOFT during conventional fallback (an option, no one uses yet...);

src/p25/Control.cpp

@@ -567,7 +567,8 @@ bool Control::processFrame(uint8_t* data, uint32_t len)
                 }
                 break;
             }
-            if (!m_dedicatedControl)
+
+            if (!m_dedicatedControl || m_trunk->m_convFallback)
                 ret = m_voice->process(data, len);
             else {
                 if (m_voiceOnControl && m_affiliations.isChBusy(m_siteData.channelNo())) {

src/p25/P25Defines.h

@@ -285,6 +285,9 @@ namespace p25
     const uint8_t   LC_NET_STS_BCAST = 0x24U;           // NET STS BCAST - Network Status Broadcast
     const uint8_t   LC_CONV_FALLBACK = 0x2AU;           // CONV FALLBACK - Conventional Fallback
 
+    // LDUx/TDULC Motorola Link Control Opcode(s)
+    const uint8_t   LC_FAILSOFT = 0x02U;                // FAILSOFT - Failsoft
+
     // TSBK ISP/OSP Shared Opcode(s)
     const uint8_t   TSBK_IOSP_GRP_VCH = 0x00U;          // GRP VCH REQ - Group Voice Channel Request (ISP), GRP VCH GRANT - Group Voice Channel Grant (OSP)
     const uint8_t   TSBK_IOSP_UU_VCH = 0x04U;           // UU VCH REQ - Unit-to-Unit Voice Channel Request (ISP), UU VCH GRANT - Unit-to-Unit Voice Channel Grant (OSP)

src/p25/lc/tdulc/LC_FAILSOFT.cpp

@@ -0,0 +1,80 @@
+/**
+* Digital Voice Modem - Host Software
+* GPLv2 Open Source. Use is subject to license terms.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* @package DVM / Host Software
+*
+*/
+/*
+*   Copyright (C) 2023 by Bryan Biedenkapp N2PLL
+*
+*   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 2 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, write to the Free Software
+*   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+#include "Defines.h"
+#include "p25/lc/tdulc/LC_FAILSOFT.h"
+#include "Log.h"
+#include "Utils.h"
+
+using namespace p25::lc::tdulc;
+using namespace p25::lc;
+using namespace p25;
+
+#include <cassert>
+#include <cmath>
+
+// ---------------------------------------------------------------------------
+//  Public Class Members
+// ---------------------------------------------------------------------------
+
+/// <summary>
+/// Initializes a new instance of the LC_FAILSOFT class.
+/// </summary>
+LC_FAILSOFT::LC_FAILSOFT() : TDULC()
+{
+    m_lco = p25::LC_FAILSOFT;
+    m_mfId = p25::P25_MFG_MOT;
+}
+
+/// <summary>
+/// Decode a terminator data unit w/ link control.
+/// </summary>
+/// <param name="data"></param>
+/// <returns>True, if TDULC was decoded, otherwise false.</returns>
+bool LC_FAILSOFT::decode(const uint8_t* data)
+{
+    assert(data != NULL);
+
+    /* stub */
+
+    return true;
+}
+
+/// <summary>
+/// Encode a terminator data unit w/ link control.
+/// </summary>
+/// <param name="data"></param>
+void LC_FAILSOFT::encode(uint8_t* data)
+{
+    assert(data != NULL);
+
+    ulong64_t rsValue = 0U;
+
+    rsValue = m_mfId;
+    rsValue = (rsValue << 56);
+
+    std::unique_ptr<uint8_t[]> rs = TDULC::fromValue(rsValue);
+    TDULC::encode(data, rs.get());
+}

src/p25/lc/tdulc/LC_FAILSOFT.h

@@ -0,0 +1,57 @@
+/**
+* Digital Voice Modem - Host Software
+* GPLv2 Open Source. Use is subject to license terms.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* @package DVM / Host Software
+*
+*/
+/*
+*   Copyright (C) 2023 by Bryan Biedenkapp N2PLL
+*
+*   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 2 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, write to the Free Software
+*   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+#if !defined(__P25_LC_TSBK__LC_FAILSOFT_H__)
+#define  __P25_LC_TSBK__LC_FAILSOFT_H__
+
+#include "Defines.h"
+#include "p25/lc/TDULC.h"
+
+namespace p25
+{
+    namespace lc
+    {
+        namespace tdulc
+        {
+            // ---------------------------------------------------------------------------
+            //  Class Declaration
+            //      Implements FAILSOFT - Failsoft
+            // ---------------------------------------------------------------------------
+
+            class HOST_SW_API LC_FAILSOFT : public TDULC {
+            public:
+                /// <summary>Initializes a new instance of the LC_FAILSOFT class.</summary>
+                LC_FAILSOFT();
+
+                /// <summary>Decode a terminator data unit w/ link control.</summary>
+                bool decode(const uint8_t* data);
+                /// <summary>Encode a terminator data unit w/ link control.</summary>
+                void encode(uint8_t* data);
+            };
+        } // namespace tdulc
+    } // namespace lc
+} // namespace p25
+
+#endif // __P25_LC_TSBK__LC_FAILSOFT_H__

src/p25/lc/tdulc/TDULCFactory.h

@@ -7,7 +7,7 @@
 *
 */
 /*
-*   Copyright (C) 2022 by Bryan Biedenkapp N2PLL
+*   Copyright (C) 2023 by Bryan Biedenkapp N2PLL
 *
 *   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
@@ -42,6 +42,8 @@
 #include "p25/lc/tdulc/LC_SYS_SRV_BCAST.h"
 #include "p25/lc/tdulc/LC_TEL_INT_VCH_USER.h"
 
+#include "p25/lc/tdulc/LC_FAILSOFT.h"
+
 namespace p25
 {
     namespace lc

src/p25/packet/Trunk.cpp

@@ -1316,10 +1316,9 @@ void Trunk::writeRF_ControlData(uint8_t frameCnt, uint8_t n, bool adjSS)
 
     if (m_convFallback) {
         bool fallbackTx = (frameCnt % 253U) == 0U;
-        if (fallbackTx && n == 7U) {
+        if (fallbackTx && n == 8U) {
             if (m_convFallbackPacketDelay >= CONV_FALLBACK_PACKET_DELAY) {
                 std::unique_ptr<lc::tdulc::LC_CONV_FALLBACK> lc = new_unique(lc::tdulc::LC_CONV_FALLBACK);
-
                 for (uint8_t i = 0U; i < 3U; i++) {
                     writeRF_TDULC(lc.get(), true);
                 }
@@ -1329,6 +1328,12 @@ void Trunk::writeRF_ControlData(uint8_t frameCnt, uint8_t n, bool adjSS)
                 m_convFallbackPacketDelay++;
             }
         }
+        else {
+            if (n == 8U) {
+                std::unique_ptr<lc::tdulc::LC_FAILSOFT> lc = new_unique(lc::tdulc::LC_FAILSOFT);
+                writeRF_TDULC(lc.get(), true);
+            }
+        }
 
         return;
     }