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Commit bb513013 authored by echicken's avatar echicken
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Support for KISS-mode TNCs and partial support for the AX.25 protocol.

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exec/load/kissAX25lib.js 0 → 100644
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// kissAX25lib.js for Synchronet 3.15+
// echicken -at- bbs.electronicchicken.com (VE3XEC)
// Support for KISS TNCs and partial support for the AX.25 protocol.
load("ax25defs.js");
// Return a kissTNC object (see below) based on 'section' of ctrl/kiss.ini
function loadKISSInterface(section) {
var f = new File(system.ctrl_dir + "kiss.ini");
f.open("r");
if(!f.exists || !f.is_open) return false;
var kissINI = f.iniGetObject(section);
f.close();
var tnc = new kissTNC(section, kissINI.callsign, kissINI.ssid, kissINI.serialPort, Number(kissINI.baudRate));
return tnc;
}
// Load and configure all KISS TNCs, return an array of kissTNC objects (see below)
function loadKISSInterfaces() {
var f = new File(system.ctrl_dir + "kiss.ini");
f.open("r");
if(!f.exists || !f.is_open) return false;
var kissINI = f.iniGetAllObjects();
f.close();
var kissTNCs = new Array();
for(var i = 0; i < kissINI.length; i++) kissTNCs.push(new kissTNC(kissINI[i].name, kissINI[i].callsign, kissINI[i].ssid, kissINI[i].serialPort, Number(kissINI[i].baudRate)));
return kissTNCs;
}
// Create an object representing a KISS TNC, where object.handle is a COM object
function kissTNC(name, callsign, ssid, serialPort, baudRate) {
this.name = name;
this.callsign = callsign;
this.ssid = ssid;
this.handle = new COM(serialPort);
this.handle.baud_rate = parseInt(baudRate);
this.handle.open();
if(!this.handle.is_open) return false;
// Read a KISS frame from a TNC, return an AX.25 packet (array of bytes) less the flags and FCS
this.getKISSFrame = function() {
var escaped = false;
var kissByte = this.handle.readBin(2);
if(kissByte != (KISS_FEND<<8)) return false;
var kissFrame = new Array();
// To do: add a timeout to this loop
while(kissByte != KISS_FEND) {
kissByte = this.handle.readBin(1);
if(kissByte == -1) continue;
if((kissByte & KISS_FESC) == KISS_FESC) {
escaped = true;
continue;
}
if(escaped && (kissByte & KISS_TFESC) == KISS_TFESC) {
kissFrame.push(KISS_FESC);
} else if(escaped && (kissByte & KISS_TFEND) == KISS_TFEND) {
kissFrame.push(KISS_FEND);
} else if(kissByte != KISS_FEND) {
kissFrame.push(kissByte);
}
escaped = false;
}
return kissFrame;
}
// Write a KISS frame to a TNC where p is an AX.25 packet (array of bytes) less the flags and FCS
this.sendKISSFrame = function(p) {
var kissByte;
this.handle.writeBin((KISS_FEND<<8), 2);
for(var i = 0; i < p.length; i++) {
kissByte = p[i];
if(kissByte == KISS_FEND) {
this.handle.writeBin((KISS_FESC<<8)|KISS_TFEND, 2);
} else if(kissByte == KISS_FESC) {
this.handle.writeBin((KISS_FESC<<8)|KISS_TFESC, 2);
} else {
this.handle.writeBin(kissByte, 1);
}
}
this.handle.writeBin(KISS_FEND, 1);
}
}
function logByte(b) {
log(format("%d%d%d%d%d%d%d%d\r\n", (b & (1<<7)) ? 1 : 0, (b & (1<<6)) ? 1 : 0, (b & (1<<5)) ? 1 : 0, (b & (1<<4)) ? 1 : 0, (b & (1<<3)) ? 1 : 0, (b & (1<<2)) ? 1 : 0, (b & (1<<1)) ? 1 : 0, (b & (1<<0)) ? 1 : 0 ));
}
function ax25packet() {
this.assemble = function(destination, destinationSSID, source, sourceSSID, repeaters, control, pid, information) {
this.destination = destination;
this.destinationSSID = destinationSSID;
this.source = source;
this.sourceSSID = sourceSSID;
this.repeaters = repeaters;
this.control = control;
this.pid = pid;
this.information = information;
this.clientID = this.destination.replace(/\s/, "") + this.destinationSSID + this.source.replace(/\s/, "") + this.sourceSSID;
this.raw = new Array();
var dest = stringToByteArray(this.destination);
for(var i = 0; i < dest.length; i++) this.raw.push((dest[i]<<1));
this.raw.push((parseInt(this.destinationSSID)<<1));
var src = stringToByteArray(this.source);
for(var i = 0; i < src.length; i++) this.raw.push((src[i]<<1));
if(!repeaters) {
this.raw.push((parseInt(this.sourceSSID)<<1)|(1<<0));
} else {
this.raw.push((parseInt(this.sourceSSID)<<1));
for(var i = 0; i < this.repeaters.length; i++) {
var repeater = this.repeaters[i].split("-");
var repeaterCall = stringToByteArray(repeater[0]);
for(var j = 0; j < repeaterCall.length; j++) this.raw.push((repeaterCall[j]<<1));
var repeaterSSID = (parseInt(repeater[1])<<1);
if(i == this.repeaters.length - 1) repeaterSSID |= (1<<0);
this.raw.push(repeaterSSID);
}
}
this.raw.push(this.control);
if(this.pid !== undefined) this.raw.push(this.pid);
if(this.information !== undefined) {
for(var i = 0; i < this.information.length; i++) {
this.raw.push(this.information[i]);
}
this.ns = ((this.control & NS)>>>1);
}
if((this.control & I_FRAME) == I_FRAME || (this.control & S_FRAME) == S_FRAME) this.nr = ((this.control & NR)>>>5);
}
this.disassemble = function(p) {
this.raw = p;
this.destination = "";
for(var i = 0; i < 6; i++) this.destination += ascii((p[i]>>1));
this.destinationSSID = ((p[6] & A_SSID)>>1);
this.source = "";
for(var i = 7; i < 13; i++) this.source += ascii(p[i]>>1);
var i = 13;
this.sourceSSID = ((p[i] & A_SSID)>>1);
this.clientID = this.destination.replace(/\s/, "") + this.destinationSSID + this.source.replace(/\s/, "") + this.sourceSSID;
// Either the source callsign & SSID pair was the end of the address field, or we need to tack on a repeater path
if(p[i] & (1<<0)) {
this.repeaters = [0];
} else {
var repeater = "";
this.repeaters = new Array();
for(var i = 14; i <= 78; i++) {
if(repeater.length == 6) {
repeater += "-" + ((p[i] & A_SSID)>>1);
this.repeaters.push(repeater);
repeater = "";
} else {
repeater += ascii((p[i]>>1));
}
if(p[i] & (1<<0)) break;
}
}
this.control = p[i + 1]; // Implementation can compare this against bitmasks from ax25defs.js to determine frame type.
// A U frame or an I frame will have a PID octet and an information field
if((this.control & U_FRAME_UI) == U_FRAME_UI || (this.control & U_FRAME_FRMR) == U_FRAME_FRMR || (this.control & I_FRAME) == I_FRAME) {
this.pid = p[i + 2];
this.information = new Array();
for(var x = i + 3; x < p.length; x++) this.information.push(p[x]);
}
// An I frame will have N(S) (send-sequence) bits in the control octet
if((this.control & I_FRAME) == I_FRAME) this.ns = ((this.control & NS)>>>1);
// An I frame or an S frame will have N(R) (receive sequence) bits in the control octet
if((this.control & I_FRAME) == I_FRAME || (this.control & S_FRAME) == S_FRAME) this.nr = ((this.control & NR)>>>5);
}
this.logPacket = function() {
var x = "Unknown or unhandled frame type";
if((this.control & U_FRAME_SABM) == U_FRAME_SABM) {
x = "U_FRAME_SABM";
} else if((this.control & U_FRAME_UA) == U_FRAME_UA) {
x = "U_FRAME_UA";
} else if((this.control & U_FRAME_FRMR) == U_FRAME_FRMR) {
x = "U_FRAME_FRMR";
} else if((this.control & U_FRAME_DISC) == U_FRAME_DISC) {
x = "U_FRAME_DISC";
} else if((this.control & U_FRAME) == U_FRAME) {
x = "U_FRAME";
} else if((this.control & S_FRAME_REJ) == S_FRAME_REJ) {
x = "S_FRAME_REJ, N(R): " + this.nr;
} else if((this.control & S_FRAME_RNR) == S_FRAME_RNR) {
x = "S_FRAME_RNR, N(R): " + this.nr;
} else if((this.control & S_FRAME) == S_FRAME) {
x = "S_FRAME, N(R): " + this.nr;
} else if((this.control & I_FRAME) == I_FRAME) {
x = "I_FRAME, N(R): " + this.nr + ", N(S): " + this.ns;
}
log(LOG_DEBUG, this.source + "-" + this.sourceSSID + "->" + this.destination + "-" + this.destinationSSID + ": " + x);
}
}
// Turns a string into an array of ASCII character codes
function stringToByteArray(s) {
s = s.split("");
var r = new Array();
for(var i = 0; i < s.length; i++) r.push(ascii(s[i]));
return r;
}
// Turns an array of ASCII character codes into a string
function byteArrayToString(s) {
var r = "";
for(var i = 0; i < s.length; i++) r += ascii(s[i]);
return r;
}
// Create an AX.25 client object from an ax25packet() object
function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
this.kissTNC = k;
if(source == k.callsign && sourceSSID == k.ssid) {
this.callsign = destination;
this.ssid = destinationSSID;
} else {
this.callsign = source;
this.ssid = sourceSSID;
}
this.clientID = destination.replace(/\s/, "") + destinationSSID + source.replace(/\s/, "") + sourceSSID;
this.ssv = 0; // Send Sequence Variable
this.rsv = 0; // Receive Sequence Variable
this.ns = 0; // Client's last reported N(S)
this.nr = 0; // Client's last reported N(R)
this.t1 = 0; // Timer T1
this.t2 = 0; // Timer T2
this.t3 = 0; // Timer T3
this.resend = false;
this.reject = false;
this.connected = false;
this.sentIFrames = [];
this.lastPacket = false;
/* Process and respond to ax25packet object 'p', returning false unless
'p' is an I frame, in which case the I frame payload will be returned
as an array of bytes.
Argument 'p' is optional; if it is not supplied, this function will
try to read an AX.25 frame from the KISS interface associated with
this client. */
this.receive = function(p) {
if(p == undefined) {
var kissFrame = this.kissTNC.getKISSFrame();
if(!kissFrame) return false;
var p = new ax25packet();
p.disassemble(kissFrame);
if(p.destination != this.kissTNC.callsign || p.destinationSSID != this.kissTNC.ssid) return false;
}
p.logPacket();
var retval = false;
var a = new ax25packet;
if((p.control & U_FRAME_SABM) == U_FRAME_SABM) {
this.connected = true;
if(this.reject) {
this.reject = false;
} else {
this.rsv = 0;
this.ssv = 0;
}
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_UA);
log(LOG_INFO, this.kissTNC.callsign + "-" + this.kissTNC.ssid + ": Connection from " + this.callsign + "-" + this.ssid);
} else if((p.control & U_FRAME_DM) == U_FRAME_DM) {
this.connected = false;
} else if((p.control & U_FRAME_UA) == U_FRAME_UA) {
if((this.lastPacket.control & U_FRAME_SABM) == U_FRAME_SABM) this.connected = true;
if((this.lastPacket.control & U_FRAME_DISC) == U_FRAME_DISC) this.connected = false;
return retval;
} else if((p.control & U_FRAME_FRMR) == U_FRAME_FRMR && this.connected) {
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_SABM);
this.rsv = 0;
this.ssv = 0;
} else if((p.control & U_FRAME_DISC) == U_FRAME_DISC) {
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_UA);
this.connected = false;
this.reject = false;
} else if((p.control & U_FRAME) == U_FRAME) {
// Unnumbered Information fields should be processed, I guess.
return retval;
} else if(!this.connected) {
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_DM);
} else if((p.control & S_FRAME_REJ) == S_FRAME_REJ) {
this.resend = true;
a.raw = this.sentIFrames[p.nr - 1];
this.nr = p.nr;
} else if((p.control & S_FRAME_RNR) == S_FRAME_RNR) {
this.nr = p.nr;
} else if((p.control & S_FRAME) == S_FRAME) {
// This is a Receive-Ready and an acknowledgement of all frames in the sequence up to client's N(R)
this.nr = p.nr;
if(p.nr == 7 && this.sentIFrames.length == 7) {
this.sentIFrames = []; // Client acknowledges the entire sequence, we can ditch our stored sent packets
return retval;
} else if(p.nr == 7 && this.sentIFrames.length > 7) {
this.sentIFrames = this.sentIFrames.slice(7); // If we sent more I frames before they acknowledged our N(S)=7, we don't want to delete them yet.
return retval;
} else if(this.resend && p.nr < this.sentIFrames.length) {
a.raw = this.sentIFrames[p.nr - 1];
} else if(this.resend && p.nr >= this.sentIFrames.length) {
this.resend = false;
return retval;
} else {
return retval;
}
} else if((p.control & I_FRAME) == I_FRAME) {
this.ns = p.ns;
this.nr = p.nr;
if(p.ns != this.rsv) {
if(this.reject) return retval;
// Send a REJ, requesting retransmission of the frame whose N(S) value matches our current RSV
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, (S_FRAME_REJ|(this.rsv<<5)));
this.reject = true;
} else if(p.information.length <= 256) {
// This is an actual, good and expected I frame
this.rsv++;
if(this.rsv > 7) this.rsv = 0;
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, (S_FRAME_RR|(this.rsv<<5)));
if(p.hasOwnProperty("information") || p.information.length > 0) retval = p.information;
this.reject = false;
} else {
// Send a FRMR with the offending control field, our RSV and SSV, and the "Z" flag to indicate an invalid N(R)
var i = [p.control, (this.rsv<<5)|(this.ssv<<1), 0];
if(p.information.length > 256) i[2] = (1<<2);
if(p.nr != this.ssv) i[2]|=(1<<3);
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, (U_FRAME_FRMR), PID_NONE, i);
this.reject = true;
}
} else {
return retval;
}
this.sendPacket(a);
return retval;
}
// Send ax25Packet object 'a' to an ax25Client
this.sendPacket = function(a) {
this.lastPacket = a;
this.kissTNC.sendKISSFrame(a.raw);
a.logPacket();
}
// Send an I Frame to an ax25Client, with payload 'p'
this.send = function(p) {
var a = new ax25packet();
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, (I_FRAME|(this.rsv<<5)|(this.ssv<<1)), PID_NONE, p);
this.sendPacket(a);
this.ssv++;
if(this.ssv > 7) this.ssv = 0;
this.sentIFrames.push(a);
}
// Connect this client to an AX.25 host, 5 attempts at 3 second intervals
// (Attempts and intervals should probably be made configurable)
this.connect = function() {
var a = new ax25packet();
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_SABM);
var i = 0;
while(!c.connected && i < 5){
this.sendPacket(a);
mswait(3000);
this.receive();
i++;
}
if(c.connected) {
log(LOG_INFO, this.kissTNC.callsign + "-" + this.kissTNC.ssid + " connected to " + this.callsign + "-" + this.ssid);
} else {
log(LOG_INFO, this.kissTNC.callsign + "-" + this.kissTNC.ssid + " failed to connect to " + this.callsign + "-" + this.ssid);
}
}
// Disconnect this client, 5 attempts at 3 second intervals
// (Attempts and intervals should probably be made configurable)
this.disconnect = function() {
var a = new ax25packet();
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_DISC);
var i = 0;
while(c.connected && i < 5){
this.sendPacket(a);
mswait(3000);
this.receive();
i++;
}
if(c.connected) {
c.connected = false;
log(LOG_INFO, this.callsign + "-" + this.ssid + " failed to acknowledge U_FRAME_DISC from " + this.kissTNC.callsign + "-" + this.kissTNC.ssid);
} else {
log(LOG_INFO, this.callsign + "-" + this.ssid + " disconnected from " + this.kissTNC.callsign + "-" + this.kissTNC.ssid);
}
}
}
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