Restore the branch

AX25Control.cpp

@@ -0,0 +1,252 @@
+/*
+ *	Copyright (C) 2020 Jonathan Naylor, G4KLX
+ *
+ *	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; version 2 of the License.
+ *
+ *	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.
+ */
+
+#include "AX25Control.h"
+#include "AX25Defines.h"
+#include "Utils.h"
+#include "Log.h"
+
+#include <cstdio>
+#include <cassert>
+#include <cstring>
+#include <ctime>
+
+// #define	DUMP_AX25
+
+const unsigned char BIT_MASK_TABLE[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U };
+
+#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
+#define READ_BIT1(p,i)    (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
+
+CAX25Control::CAX25Control(CAX25Network* network, bool trace) :
+m_network(network),
+m_trace(trace),
+m_enabled(true),
+m_fp(NULL)
+{
+}
+
+CAX25Control::~CAX25Control()
+{
+}
+
+bool CAX25Control::writeModem(unsigned char *data, unsigned int len)
+{
+	assert(data != NULL);
+
+	if (!m_enabled)
+		return false;
+
+    if (m_trace)
+        decode(data, len);
+
+    CUtils::dump(1U, "AX.25 received packet", data, len);
+
+    if (m_network == NULL)
+        return true;
+
+    return m_network->write(data, len);
+}
+
+unsigned int CAX25Control::readModem(unsigned char* data)
+{
+    assert(data != NULL);
+
+    if (m_network == NULL)
+        return 0U;
+
+    if (!m_enabled)
+        return 0U;
+
+    unsigned int length = m_network->read(data, 500U);
+
+    if (length > 0U)
+        CUtils::dump(1U, "AX.25 transmitted packet", data, length);
+
+    return length;
+}
+
+bool CAX25Control::openFile()
+{
+	if (m_fp != NULL)
+		return true;
+
+	time_t t;
+	::time(&t);
+
+	struct tm* tm = ::localtime(&t);
+
+	char name[100U];
+	::sprintf(name, "AX25_%04d%02d%02d_%02d%02d%02d.ambe", tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	m_fp = ::fopen(name, "wb");
+	if (m_fp == NULL)
+		return false;
+
+	::fwrite("AX25", 1U, 4U, m_fp);
+
+	return true;
+}
+
+bool CAX25Control::writeFile(const unsigned char* data, unsigned int length)
+{
+	if (m_fp == NULL)
+		return false;
+
+	::fwrite(&length, 1U, sizeof(unsigned int), m_fp);
+	::fwrite(data, 1U, length, m_fp);
+
+	return true;
+}
+
+void CAX25Control::closeFile()
+{
+	if (m_fp != NULL) {
+		::fclose(m_fp);
+		m_fp = NULL;
+	}
+}
+
+void CAX25Control::enable(bool enabled)
+{
+	m_enabled = enabled;
+}
+
+void CAX25Control::decode(const unsigned char* data, unsigned int length)
+{
+    assert(data != NULL);
+    assert(length >= 15U);
+
+    std::string text;
+
+    bool more = decodeAddress(data + 7U, text);
+
+    text += '>';
+
+    decodeAddress(data + 0U, text);
+
+    unsigned int n = 14U;
+    while (more && n < length) {
+        text += ',';
+        more = decodeAddress(data + n, text, true);
+        n += 7U;
+    }
+
+    text += ' ';
+
+    if ((data[n] & 0x01U) == 0x00U) {
+        // I frame
+        char t[20U];
+        ::sprintf(t, "<I S%u R%u>", (data[n] >> 1) & 0x07U, (data[n] >> 5) & 0x07U);
+        text += t;
+    } else {
+        if ((data[n] & 0x02U) == 0x00U) {
+            // S frame
+            char t[20U];
+            switch (data[n] & 0x0FU) {
+            case 0x01U:
+                sprintf(t, "<RR R%u>", (data[n] >> 5) & 0x07U);
+                break;
+            case 0x05U:
+                sprintf(t, "<RNR R%u>", (data[n] >> 5) & 0x07U);
+                break;
+            case 0x09U:
+                sprintf(t, "<REJ R%u>", (data[n] >> 5) & 0x07U);
+                break;
+            case 0x0DU:
+                sprintf(t, "<SREJ R%u>", (data[n] >> 5) & 0x07U);
+                break;
+            default:
+                sprintf(t, "<Unknown R%u>", (data[n] >> 5) & 0x07U);
+                break;
+            }
+
+            text += t;
+            LogMessage("AX.25, %s", text.c_str());
+            return;
+        } else {
+            // U frame
+            switch (data[n] & 0xEFU) {
+            case 0x6FU:
+                text += "<SABME>";
+                break;
+            case 0x2FU:
+                text += "<SABM>";
+                break;
+            case 0x43U:
+                text += "<DISC>";
+                break;
+            case 0x0FU:
+                text += "<DM>";
+                break;
+            case 0x63U:
+                text += "<UA>";
+                break;
+            case 0x87U:
+                text += "<FRMR>";
+                break;
+            case 0x03U:
+                text += "<UI>";
+                break;
+            case 0xAFU:
+                text += "<XID>";
+                break;
+            case 0xE3U:
+                text += "<TEST>";
+                break;
+            default:
+                text += "<Unknown>";
+                break;
+            }
+
+            if ((data[n] & 0xEFU) != 0x03U) {
+                LogMessage("AX.25, %s", text.c_str());
+                return;
+            }
+        }
+    }
+
+    n += 2U;
+
+    LogMessage("AX.25, %s %.*s", text.c_str(), length - n, data + n);
+}
+
+bool CAX25Control::decodeAddress(const unsigned char* data, std::string& text, bool isDigi) const
+{
+	assert(data != NULL);
+
+	for (unsigned int i = 0U; i < 6U; i++) {
+		char c = data[i] >> 1;
+		if (c != ' ')
+			text += c;
+	}
+
+	unsigned char ssid = (data[6U] >> 1) & 0x0FU;
+	if (ssid > 0U) {
+		text += '-';
+		if (ssid >= 10U) {
+			text += '1';
+			text += '0' + ssid - 10U;
+		}
+		else {
+			text += '0' + ssid;
+		}
+	}
+
+	if (isDigi) {
+		if ((data[6U] & 0x80U) == 0x80U)
+			text += '*';
+	}
+
+	return (data[6U] & 0x01U) == 0x00U;
+}

AX25Control.h

@@ -0,0 +1,50 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   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(AX25Control_H)
+#define	AX25Control_H
+
+#include "AX25Network.h"
+
+#include <string>
+
+class CAX25Control {
+public:
+	CAX25Control(CAX25Network* network, bool trace);
+	~CAX25Control();
+
+	bool writeModem(unsigned char* data, unsigned int len);
+
+	unsigned int readModem(unsigned char* data);
+
+	void enable(bool enabled);
+
+private:
+	CAX25Network* m_network;
+	bool          m_trace;
+	bool          m_enabled;
+	FILE*         m_fp;
+
+	void decode(const unsigned char* data, unsigned int length);
+	bool decodeAddress(const unsigned char* data, std::string& text, bool isDigi = false) const;
+	bool openFile();
+	bool writeFile(const unsigned char* data, unsigned int length);
+	void closeFile();
+};
+
+#endif

AX25Defines.h

@@ -0,0 +1,39 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   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(AX25Defines_H)
+#define	AX25Defines_H
+
+const unsigned int AX25_CALLSIGN_TEXT_LENGTH = 6U;
+const unsigned int AX25_SSID_LENGTH          = 1U;
+const unsigned int AX25_CALLSIGN_LENGTH      = 7U;
+
+const unsigned int AX25_MAX_DIGIPEATERS = 6U;
+
+const unsigned char AX25_PID_NOL3       = 0xF0U;
+
+const unsigned int  AX25_MAX_FRAME_LENGTH_BYTES = 330U;     // Callsign (7) + Callsign (7) + 8 Digipeaters (56) +
+															// Control (1) + PID (1) + Data (256) + Checksum (2)
+const unsigned char AX25_KISS_DATA = 0x00U;
+
+const unsigned char AX25_FEND  = 0xC0U;
+const unsigned char AX25_FESC  = 0xDBU;
+const unsigned char AX25_TFEND = 0xDCU;
+const unsigned char AX25_TFESC = 0xDDU;
+
+#endif