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Commit 6b84f5d9 authored by echicken's avatar echicken
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Some cleanup, a few additions, a few bugfixes, and much commenting. 

To do: timers, flow control improvements.
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exec/load/kissAX25lib.js
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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.
/* kissAX25lib.js for Synchronet 3.15+
echicken -at- bbs.electronicchicken.com (VE3XEC)
This library provides support for the KISS and AX.25 protocols. AX.25
support is partial and needs much improvement.
The following functions are available:
loadKISSInterface(section)
- 'section' is the name of a section from ctrl/kiss.ini
- Returns a kissTNC object
loadKISSInterfaces()
- Takes no arguments and loads all interfaces defined in ctrl/kiss.ini
- Returns an array of kissTNC objects
logbyte(b)
- Adds a representation of an eight-bit byte to the log (eg. 00111100)
- Occasionally useful for debugging
stringToByteArray(s)
- Converts string 's' into an array of ASCII values
- Returns an array with one element per character in 's'
byteArrayToString(s)
- Converts byte array 's' (as above) into a string and returns it
The following objects are available:
kissTNC(name, callsign, ssid, serialPort, baudRate)
Normally you'll use loadKISSInterface(section) to instantiate these,
however the arguments it accepts are obvious if you want to create
instances manually and bypass kiss.ini.
Properties:
'name'
A textual name for the TNC (a section heading from kiss.ini)
'callsign'
The callsign assigned to this TNC
'ssid'
The SSID assigned to this TNC
'handle'
A COM object representing the serial connection to the TNC. This
has its own methods for reading and writing data to and from the
TNC.
Methods:
getKISSFrame()
A bit of a misnomer. What it actually does is read a KISS frame
from the TNC and then returns an array representing the bytes of
the AX.25 packet contained therein.
sendKISSFrame(p)
Where 'p' is array containing the bytes of an AX.25 frame, this
will encapsulate that packet in a KISS frame and then send it to
the TNC for transmission.
beacon()
Causes the TNC to transmit a UI frame containing the value of
system.name (the name of your BBS.) I'll probably make the beacon
text configurable in kiss.ini later on.
ax25packet()
Represents a single AX.25 frame, but is mostly devoid of properties
until either the assemble() or disassemble() methods are called.
assemble(destination, destinationSSID, source, sourceSSID, repeaters, control, pid, information)
- 'repeaters' is the digipeater path, an array of 'callsign-ssid'
- 'control' is a control field octet from ax25defs.js, eg. U_FRAME
- 'pid' is a protocol ID octet from ax25defs.js (usually PID_NONE)
- 'information' is the payload of an I or UI frame, eg. the return
value of stringToByteArray(s)
disassemble(p)
'p' is an array containing the bytes of an AX.25 frame, eg. the
return value of kissTNC.getKISSFrame().
logPacket()
Writes some information about this packet to the log.
After assemble() or disassemble() has been called, your ax25packet
object will have the following properties:
'destination'
The remote callsign
'destinationSSID'
The remote SSID
'source'
The local callsign
'sourceSSID'
The local SSID
'repeaters'
An array of 'callsign-ssid' representing the digipeater path
'control'
The control octet, which can be compared bitwise against masks
defined in ax25defs.js
'pid'
The protocol ID octet, which can be compared bitwise against
masks defined in ax25defs.js
'information'
The payload if applicable (I or UI frames only,) good for use
with byteArrayToString(s)
'clientID'
A unique ID for the sender or recipient, for internal use
'raw'
An array representing the bytes of the frame, good for use
with kissTNC.sendKISSFrame(p)
ax25Client(destination, destinationSSID, source, sourceSSID, k)
Can represent a client that has called you, but can also be used to
represent an outgoing session that you have initiated.
All arguments but 'k' are self-explanatory. 'k' is a reference to a
kissTNC object (see above) and will be the interface through which all
traffic for this client shall pass.
Properties:
'kissTNC'
A reference to the kissTNC object representing the TNC through
which all traffic to and from this client passes
'callsign'
The local callsign
'ssid'
The local SSID
'clientID'
A unique ID for this client, for internal use, same as
ax25packet.clientID
'ssv'
The send-sequence variable
'rsv'
The receive-sequence variable
'ns'
Client's last reported N(S)
'nr'
Client's last reported N(R)
't1'
Timer T1 (Placeholder; not yet implemented)
't2'
Timer T2 (Placeholder; not yet implemented)
't3'
Timer T3 (Placeholder; not yet implemented)
'resend'
true/false, for internal use
'reject'
true/false, for internal use
'connected'
true/false, whether or not this client is connected
'sentIFrames'
An array of the last seven I frames that we have sent to this
client.
'lastPacket'
An ax25packet object representing the last packet that we sent to
this client.
Methods:
receive(p)
'p' is an optional ax25packet object; if omitted, an attempt will
be made to read an AX.25 frame from the KISS TNC associated with
this client. Returns false if there is no AX.25 frame waiting to
be received.
sendPacket(a)
'a' is an ax25packet object that will be sent to the client via
its associated KISS TNC.
send(p)
Sends an I frame to the client, where 'p' is the payload (eg. a
return value from stringToByteArray(s).
connect()
Makes five attempts to connect to the client, at three second
intervals. (Attempts and intervals to be made configurable at
some point.) To verify the connection state afterward, check
the value of ax25client.connected.
disconnect()
Makes five attempts to disconnect the client, at three second
intervals. (Attempts and intervals to be made configurable at
some point. To verify the connection state afterward, check the
value of ax25client.connected.
*/
load("ax25defs.js");
......@@ -8,7 +221,8 @@ load("ax25defs.js");
function loadKISSInterface(section) {
var f = new File(system.ctrl_dir + "kiss.ini");
f.open("r");
if(!f.exists || !f.is_open) return false;
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));
......@@ -19,11 +233,14 @@ function loadKISSInterface(section) {
function loadKISSInterfaces() {
var f = new File(system.ctrl_dir + "kiss.ini");
f.open("r");
if(!f.exists || !f.is_open) return false;
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)));
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;
}
......@@ -35,18 +252,21 @@ function kissTNC(name, callsign, ssid, serialPort, baudRate) {
this.handle = new COM(serialPort);
this.handle.baud_rate = parseInt(baudRate);
this.handle.open();
if(!this.handle.is_open) return false;
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;
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 == -1)
continue;
if((kissByte & KISS_FESC) == KISS_FESC) {
escaped = true;
continue;
......@@ -65,6 +285,7 @@ function kissTNC(name, callsign, ssid, serialPort, baudRate) {
// 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) {
if(p == undefined) return false;
var kissByte;
this.handle.writeBin((KISS_FEND<<8), 2);
for(var i = 0; i < p.length; i++) {
......@@ -79,6 +300,12 @@ function kissTNC(name, callsign, ssid, serialPort, baudRate) {
}
this.handle.writeBin(KISS_FEND, 1);
}
this.beacon = function() {
var a = new ax25packet();
a.assemble("BEACON", 0, this.callsign, this.ssid, false, U_FRAME_UI, PID_NONE, stringToByteArray(system.name));
this.sendKISSFrame(a.raw);
}
}
function logByte(b) {
......@@ -99,10 +326,14 @@ function ax25packet() {
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));
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));
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 {
......@@ -110,30 +341,39 @@ function ax25packet() {
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));
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);
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.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);
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));
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);
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;
......@@ -151,7 +391,8 @@ function ax25packet() {
} else {
repeater += ascii((p[i]>>1));
}
if(p[i] & (1<<0)) break;
if(p[i] & (1<<0))
break;
}
}
this.control = p[i + 1]; // Implementation can compare this against bitmasks from ax25defs.js to determine frame type.
......@@ -159,12 +400,16 @@ function ax25packet() {
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]);
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);
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);
if((this.control & I_FRAME) == I_FRAME || (this.control & S_FRAME) == S_FRAME)
this.nr = ((this.control & NR)>>>5);
}
this.logPacket = function() {
......@@ -196,14 +441,18 @@ function ax25packet() {
function stringToByteArray(s) {
s = s.split("");
var r = new Array();
for(var i = 0; i < s.length; i++) r.push(ascii(s[i]));
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]);
for(var i = 0; i < s.length; i++) {
r += ascii(s[i]);
}
return r;
}
......@@ -241,10 +490,12 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
this.receive = function(p) {
if(p == undefined) {
var kissFrame = this.kissTNC.getKISSFrame();
if(!kissFrame) return false;
if(!kissFrame)
return false;
var p = new ax25packet();
p.disassemble(kissFrame);
if(p.destination != this.kissTNC.callsign || p.destinationSSID != this.kissTNC.ssid) return false;
if(p.destination != this.kissTNC.callsign || p.destinationSSID != this.kissTNC.ssid)
return false;
}
p.logPacket();
var retval = false;
......@@ -262,8 +513,10 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
} 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;
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);
......@@ -274,7 +527,8 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
this.connected = false;
this.reject = false;
} else if((p.control & U_FRAME) == U_FRAME) {
if(p.hasOwnProperty("information") && p.information.length > 0) retval = p.information;
if(p.hasOwnProperty("information") && p.information.length > 0)
retval = p.information;
return retval;
} else if(!this.connected) {
a.assemble(this.callsign, this.ssid, this.kissTNC.callsign, this.kissTNC.ssid, false, U_FRAME_DM);
......@@ -283,7 +537,7 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
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;
this.nr = p.nr - 1;
} 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;
......@@ -305,22 +559,27 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
this.ns = p.ns;
this.nr = p.nr;
if(p.ns != this.rsv) {
if(this.reject) return retval;
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;
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;
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);
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;
}
......@@ -344,7 +603,8 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
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;
if(this.ssv > 7)
this.ssv = 0;
this.sentIFrames.push(a);
}
......@@ -354,13 +614,13 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
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){
while(!this.connected && i < 5){
this.sendPacket(a);
mswait(3000);
this.receive();
i++;
}
if(c.connected) {
if(this.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);
......@@ -373,14 +633,14 @@ function ax25Client(destination, destinationSSID, source, sourceSSID, k) {
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){
while(this.connected && i < 5){
this.sendPacket(a);
mswait(3000);
this.receive();
i++;
}
if(c.connected) {
c.connected = false;
if(this.connected) {
this.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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