[NOTICE: this commit is *EXPERIMENTAL* and implements *very* early da…

…ta support, it is expected to be buggy, incomplete or broken] implement VTUN interface (fne0) on the dvmfne (this requires dvmfne to be run as root on Linux system [untested on non-Linux] to create the tun interface); implement VIFace random MAC generation; implement P25 TIA-102.BAEB SCEP ARP (SCEP is always used for conventional data) on dvmfne; refactor P25 packet status bits (this may break things else where, beware!); properly implement P25 status bit flipping on inbound channel activity; implement functionality in the P25 and DMR DataHeader classes to calculate the proper raw PDU frame length; implement dvmfne ARP table creation and maintainence (this is buggy and requires more implementation and test); implement dvmfne VTUN -> PDU and PDU -> VTUN IP traffic forwarding (this is incomplete and requires more implementation and test); correct several issues on dvmhost p25::packet::Data with overlapped buffers;

configs/fne-config.example.yml

@@ -225,4 +225,23 @@ system:
         # Full path to the white/blacklist file.
         file: peer_list.dat
         # Amount of time between updates of white/blacklist file. (minutes)
-        time: 2
+        time: 2
+
+#
+# Packet Data Virtual Network Tunnel Configuration
+#
+vtun:
+    # Flag indicating the virtual network tunnel is enabled.
+    # (If this is enabled, dvmfne must be run as root to create the TUN interface.)
+    enabled: false
+    # Operational mode for the network tunnel (dmr or p25).
+    digitalMode: p25
+
+    # Kernel Interface Name
+    interfaceName: fne0
+    # IP address of the tunnel network interface
+    address: 192.168.1.254
+    # Netmask of the tunnel network interface
+    netmask: 255.255.255.0
+    # Broadcast address of the tunnel network interface
+    broadcast: 192.168.1.255

src/common/dmr/data/DataHeader.cpp

@@ -418,6 +418,22 @@ uint32_t DataHeader::getPacketLength() const
     }
 }
 
+/* Gets the total length in bytes of entire PDU. */
+
+uint32_t DataHeader::getPDULength() const
+{
+    if (m_DPF == DPF::RESPONSE) {
+        return 0U; // responses have no packet length as they are header only
+    }
+
+    if (m_DPF == DPF::CONFIRMED_DATA) {
+        return DMR_PDU_CONFIRMED_DATA_LENGTH_BYTES * m_blocksToFollow;
+    }
+    else {
+        return DMR_PDU_UNCONFIRMED_LENGTH_BYTES * m_blocksToFollow;
+    }
+}
+
 /* Gets the raw header data. */
 
 uint32_t DataHeader::getData(uint8_t* buffer) const

src/common/dmr/data/DataHeader.h

@@ -75,6 +75,11 @@ namespace dmr
              * @returns uint32_t Total length of packet in bytes.
              */
             uint32_t getPacketLength() const;
+            /**
+             * @brief Gets the total length in bytes of entire PDU.
+             * @returns uint32_t Total length of PDU in bytes.
+             */
+            uint32_t getPDULength() const;
 
             /**
              * @brief Gets the raw header data.

src/common/network/viface/VIFace.cpp

@@ -19,6 +19,7 @@ using namespace network::viface;
 #include <sstream>
 #include <fstream>
 #include <iomanip>
+#include <random>
 
 #include <cassert>
 #include <cstring>
@@ -332,7 +333,7 @@ VIFace::VIFace(std::string name, bool tap, int id) :
         throw std::runtime_error("Unable to create IPv4 socket channel to the NET kernel.");
     }
 
-    // Set id
+    // set id
     if (id < 0) {
         m_id = m_idSeq;
         m_idSeq++;
@@ -543,6 +544,30 @@ bool VIFace::write(const uint8_t* buffer, uint32_t length, ssize_t* lenWritten)
     return result;
 }
 
+/* Set the MAC address of the virtual interface to a random value. */
+
+void VIFace::setRandomMAC()
+{
+    // generate random MAC
+    std::random_device rd;
+    std::mt19937 mt(rd());
+
+    std::ostringstream addr;
+    addr << std::hex << std::setfill('0');
+    for (int i = 0; i < 6; i++) {
+        uint8_t macByte = 0U;
+        std::uniform_int_distribution<uint8_t> dist(1U, 254U);
+        macByte = dist(mt);
+
+        addr << std::setw(2) << (uint8_t)(0xFFU & macByte);
+        if (i != 5) {
+            addr << ":";
+        }
+    }
+
+    m_mac = addr.str();
+}
+
 /* Set the MAC address of the virtual interface. */
 
 void VIFace::setMAC(std::string mac)
@@ -567,7 +592,7 @@ std::string VIFace::getMAC() const
     std::ostringstream addr;
     addr << std::hex << std::setfill('0');
     for (int i = 0; i < 6; i++) {
-        addr << std::setw(2) << (uint8_t)(0xFF & ifr.ifr_hwaddr.sa_data[i]);
+        addr << std::setw(2) << (uint8_t)(0xFFU & ifr.ifr_hwaddr.sa_data[i]);
         if (i != 5) {
             addr << ":";
         }

src/common/network/viface/VIFace.h

@@ -121,6 +121,10 @@ namespace network
              */
             bool write(const uint8_t* buffer, uint32_t length, ssize_t* lenWritten = nullptr);
 
+            /**
+             * @brief Set the MAC address of the virtual interface to a random value.
+             */
+            void setRandomMAC();
             /**
              * @brief Set the MAC address of the virtual interface.
              *

src/common/p25/P25Defines.h

@@ -92,6 +92,10 @@ namespace p25
         const uint32_t  P25_PDU_CONFIRMED_DATA_LENGTH_BYTES = 16U;
         const uint32_t  P25_PDU_UNCONFIRMED_LENGTH_BYTES = 12U;
 
+        const uint32_t  P25_PDU_ARP_PCKT_LENGTH = 22U;
+        const uint8_t   P25_PDU_ARP_HW_ADDR_LENGTH = 3U;
+        const uint8_t   P25_PDU_ARP_PROTO_ADDR_LENGTH = 4U;
+
         const uint32_t  P25_PDU_FEC_LENGTH_BYTES = 25U;
         const uint32_t  P25_PDU_FEC_LENGTH_BITS = P25_PDU_FEC_LENGTH_BYTES * 8U - 4U; // Trellis is actually 196 bits
 
@@ -169,6 +173,9 @@ namespace p25
         /** @brief All-call Talkgroup ID */
         const uint32_t  TGID_ALL = 0xFFFFU;
 
+        /** @brief ARP Hardware Type */
+        const uint16_t  P25_PDU_ARP_CAI_TYPE = 0x21U;
+
         /** @brief ARP Request */
         const uint8_t   P25_PDU_ARP_REQUEST = 0x01U;
         /** @brief ARP Reply */

src/common/p25/P25Utils.cpp

@@ -21,47 +21,70 @@ using namespace p25::defines;
 //  Static Class Members
 // ---------------------------------------------------------------------------
 
-/* Helper to set the busy status bits on P25 frame data. */
+/* Helper to set the status bits on P25 frame data. */
 
-void P25Utils::setBusyBits(uint8_t* data, uint32_t ssOffset, bool b1, bool b2)
+void P25Utils::setStatusBits(uint8_t* data, uint32_t ssOffset, bool b1, bool b2)
 {
     assert(data != nullptr);
 
     WRITE_BIT(data, ssOffset, b1);
     WRITE_BIT(data, ssOffset + 1U, b2);
 }
 
-/* Helper to add the busy status bits on P25 frame data. */
+/* Helper to add the status bits on P25 frame data. */
 
-void P25Utils::addBusyBits(uint8_t* data, uint32_t length, bool b1, bool b2)
+void P25Utils::addStatusBits(uint8_t* data, uint32_t length, bool inbound, bool control)
 {
     assert(data != nullptr);
 
     // insert the "10" (Unknown, use for inbound or outbound) status bits
     for (uint32_t ss0Pos = P25_SS0_START; ss0Pos < length; ss0Pos += P25_SS_INCREMENT) {
         uint32_t ss1Pos = ss0Pos + 1U;
-        WRITE_BIT(data, ss0Pos, true);  // 1
-        WRITE_BIT(data, ss1Pos, false); // 0
+        WRITE_BIT(data, ss0Pos, true);              // 1
+        WRITE_BIT(data, ss1Pos, false);             // 0
     }
 
     // interleave the requested status bits (every other)
     for (uint32_t ss0Pos = P25_SS0_START; ss0Pos < length; ss0Pos += (P25_SS_INCREMENT * 2U)) {
         uint32_t ss1Pos = ss0Pos + 1U;
-        WRITE_BIT(data, ss0Pos, b1);
-        WRITE_BIT(data, ss1Pos, b2);
+        if (inbound) {
+            WRITE_BIT(data, ss0Pos, false);         // 0
+            WRITE_BIT(data, ss1Pos, true);          // 1
+        } else {
+            if (control) {
+                WRITE_BIT(data, ss0Pos, true);      // 1
+                WRITE_BIT(data, ss1Pos, false);     // 0
+            } else {
+                WRITE_BIT(data, ss0Pos, true);      // 1
+                WRITE_BIT(data, ss1Pos, true);      // 1
+            }
+        }
     }
 }
 
 /* Helper to add the idle status bits on P25 frame data. */
 
-void P25Utils::addIdleBits(uint8_t* data, uint32_t length, bool b1, bool b2)
+void P25Utils::addIdleStatusBits(uint8_t* data, uint32_t length)
+{
+    assert(data != nullptr);
+
+    for (uint32_t ss0Pos = P25_SS0_START; ss0Pos < length; ss0Pos += (P25_SS_INCREMENT * 5U)) {
+        uint32_t ss1Pos = ss0Pos + 1U;
+        WRITE_BIT(data, ss0Pos, true);              // 1
+        WRITE_BIT(data, ss1Pos, false);             // 0
+    }
+}
+
+/* Helper to add the trunk start slot status bits on P25 frame data. */
+
+void P25Utils::addTrunkSlotStatusBits(uint8_t* data, uint32_t length)
 {
     assert(data != nullptr);
 
     for (uint32_t ss0Pos = P25_SS0_START; ss0Pos < length; ss0Pos += (P25_SS_INCREMENT * 5U)) {
         uint32_t ss1Pos = ss0Pos + 1U;
-        WRITE_BIT(data, ss0Pos, b1);
-        WRITE_BIT(data, ss1Pos, b2);
+        WRITE_BIT(data, ss0Pos, true);              // 1
+        WRITE_BIT(data, ss1Pos, true);              // 1
     }
 }
 

src/common/p25/P25Utils.h

@@ -118,29 +118,37 @@ namespace p25
         }
 
         /**
-         * @brief Helper to set the busy status bits on P25 frame data.
+         * @brief Helper to set the status bits on P25 frame data.
          * @param data P25 frame data buffer.
          * @param ssOffset 
          * @param b1 Status Bit 1
          * @param b2 Status Bit 2
          */
-        static void setBusyBits(uint8_t* data, uint32_t ssOffset, bool b1, bool b2);
+        static void setStatusBits(uint8_t* data, uint32_t ssOffset, bool b1, bool b2);
         /**
-         * @brief Helper to add the busy status bits on P25 frame data.
+         * @brief Helper to add the status bits on P25 frame data.
+         *  This appropriately sets the status bits for the P25 frame, starting with 1,0 and then
+         *  properly setting 0,1 for inbound traffic, or 1,1 for idle (or 1,0 for control channels).
          * @param data P25 frame data buffer.
          * @param length 
-         * @param b1 Status Bit 1
-         * @param b2 Status Bit 2
+         * @param inbound Flag indicating inbound channel is busy.
+         * @param control Flag indicating the channel is a control channel.
          */
-        static void addBusyBits(uint8_t* data, uint32_t length, bool b1, bool b2);
+        static void addStatusBits(uint8_t *data, uint32_t length, bool inbound, bool control = false);
         /**
          * @brief Helper to add the idle status bits on P25 frame data.
+         *  This sets the status bits to 1,0 interleaved every 5th status bit pair.
+         * @param data P25 frame data buffer.
+         * @param length
+         */
+        static void addIdleStatusBits(uint8_t* data, uint32_t length);
+        /**
+         * @brief Helper to add the trunk start slot status bits on P25 frame data.
+         *  This sets the status bits to 1,1 interleaved every 5th status bit pair.
          * @param data P25 frame data buffer.
          * @param length 
-         * @param b1 Status Bit 1
-         * @param b2 Status Bit 2
          */
-        static void addIdleBits(uint8_t* data, uint32_t length, bool b1, bool b2);
+        static void addTrunkSlotStatusBits(uint8_t* data, uint32_t length);
 
         /**
          * @brief Decode bit interleaving.

src/common/p25/data/DataHeader.cpp

@@ -430,6 +430,22 @@ uint32_t DataHeader::getPacketLength() const
     }
 }
 
+/* Gets the total length in bytes of entire PDU. */
+
+uint32_t DataHeader::getPDULength() const
+{
+    if (m_fmt == PDUFormatType::RSP) {
+        return 0U; // responses have no packet length as they are header only
+    }
+
+    if (m_fmt == PDUFormatType::CONFIRMED) {
+        return P25_PDU_CONFIRMED_DATA_LENGTH_BYTES * m_blocksToFollow;
+    }
+    else {
+        return P25_PDU_UNCONFIRMED_LENGTH_BYTES * m_blocksToFollow;
+    }
+}
+
 /* Gets the raw header data. */
 
 uint32_t DataHeader::getData(uint8_t* buffer) const
@@ -457,6 +473,14 @@ uint32_t DataHeader::getExtAddrData(uint8_t* buffer) const
 void DataHeader::calculateLength(uint32_t packetLength)
 {
     uint32_t len = packetLength + 4U; // packet length + CRC32
+    if (m_fmt == PDUFormatType::UNCONFIRMED && m_sap == PDUSAP::EXT_ADDR) {
+        len += P25_PDU_HEADER_LENGTH_BYTES;
+    }
+
+    if (m_fmt == PDUFormatType::CONFIRMED && m_sap == PDUSAP::EXT_ADDR) {
+        len += 4U;
+    }
+
     uint32_t blockLen = (m_fmt == PDUFormatType::CONFIRMED) ? P25_PDU_CONFIRMED_DATA_LENGTH_BYTES : P25_PDU_UNCONFIRMED_LENGTH_BYTES;
 
     if (len > blockLen) {

src/common/p25/data/DataHeader.h

@@ -86,6 +86,11 @@ namespace p25
              * @returns uint32_t Total length of packet in bytes.
              */
             uint32_t getPacketLength() const;
+            /**
+             * @brief Gets the total length in bytes of entire PDU.
+             * @returns uint32_t Total length of PDU in bytes.
+             */
+            uint32_t getPDULength() const;
 
             /**
              * @brief Gets the raw header data.