zigbee-on-host
Version:
ZigBee stack designed to run on a host and communicate with a radio co-processor (RCP)
130 lines • 6.25 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.HDLC_TX_CHUNK_SIZE = exports.HDLC_GOOD_FCS = void 0;
exports.hdlcByteNeedsEscape = hdlcByteNeedsEscape;
exports.updateFcs = updateFcs;
exports.decodeHdlcFrame = decodeHdlcFrame;
exports.encodeByte = encodeByte;
exports.encodeHdlcFrame = encodeHdlcFrame;
/** Initial FCS value */
const HDLC_INIT_FCS = 0xffff;
/** Good FCS value. */
exports.HDLC_GOOD_FCS = 0xf0b8;
/** FCS size (number of bytes) */
const HDLC_FCS_SIZE = 2;
const HDLC_ESCAPE_XOR = 0x20;
exports.HDLC_TX_CHUNK_SIZE = 2048;
function hdlcByteNeedsEscape(aByte) {
return (aByte === 17 /* HdlcReservedByte.XON */ ||
aByte === 19 /* HdlcReservedByte.XOFF */ ||
aByte === 125 /* HdlcReservedByte.ESCAPE */ ||
aByte === 126 /* HdlcReservedByte.FLAG */ ||
aByte === 248 /* HdlcReservedByte.FLAG_SPECIAL */);
}
const HDLC_FCS_TABLE = [
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 0x1081, 0x0108,
0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 0x2102, 0x308b, 0x0210, 0x1399,
0x6726, 0x76af, 0x4434, 0x55bd, 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e,
0x54b5, 0x453c, 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 0xdecd, 0xcf44,
0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 0xef4e, 0xfec7, 0xcc5c, 0xddd5,
0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862,
0x9af9, 0x8b70, 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 0xa50a, 0xb483,
0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 0xb58b, 0xa402, 0x9699, 0x8710,
0xf3af, 0xe226, 0xd0bd, 0xc134, 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1,
0xa33a, 0xb2b3, 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 0x6b46, 0x7acf,
0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 0x7bc7, 0x6a4e, 0x58d5, 0x495c,
0x3de3, 0x2c6a, 0x1ef1, 0x0f78,
];
function updateFcs(aFcs, aByte) {
return ((aFcs >> 8) ^ HDLC_FCS_TABLE[(aFcs ^ aByte) & 0xff]) & 0xffff;
}
function decodeHdlcFrame(buffer) {
// sanity check
if (buffer.byteLength > exports.HDLC_TX_CHUNK_SIZE) {
throw new Error("HDLC frame too long");
}
const hdlcFrame = {
// data can only be smaller than incoming buffer (removed flags/escapes)
data: Buffer.alloc(buffer.byteLength),
length: 0,
fcs: HDLC_INIT_FCS,
};
let lastWasEscape = false;
for (let i = 0; i < buffer.byteLength; i++) {
const aByte = buffer[i];
if (aByte === 126 /* HdlcReservedByte.FLAG */) {
if (i > 0) {
if (hdlcFrame.length >= HDLC_FCS_SIZE && hdlcFrame.fcs === exports.HDLC_GOOD_FCS) {
// walk back the FCS writes by ignoring them from data length
hdlcFrame.length -= 2;
}
else {
throw new Error("HDLC parsing error");
}
}
}
else if (aByte === 125 /* HdlcReservedByte.ESCAPE */) {
lastWasEscape = true;
}
else {
if (lastWasEscape) {
const newByte = aByte ^ HDLC_ESCAPE_XOR;
hdlcFrame.fcs = updateFcs(hdlcFrame.fcs, newByte);
hdlcFrame.data[hdlcFrame.length] = newByte;
hdlcFrame.length += 1;
lastWasEscape = false;
}
else {
hdlcFrame.fcs = updateFcs(hdlcFrame.fcs, aByte);
hdlcFrame.data[hdlcFrame.length] = aByte;
hdlcFrame.length += 1;
}
}
}
return hdlcFrame;
}
/**
* @returns The new offset after encoded byte is added
*/
function encodeByte(hdlcFrame, aByte, dataOffset) {
if (hdlcByteNeedsEscape(aByte)) {
hdlcFrame.data[dataOffset] = 125 /* HdlcReservedByte.ESCAPE */;
dataOffset += 1;
hdlcFrame.data[dataOffset] = aByte ^ HDLC_ESCAPE_XOR;
dataOffset += 1;
}
else {
hdlcFrame.data[dataOffset] = aByte;
dataOffset += 1;
}
hdlcFrame.fcs = updateFcs(hdlcFrame.fcs, aByte);
return dataOffset;
}
function encodeHdlcFrame(buffer) {
// sanity check
if (buffer.byteLength > exports.HDLC_TX_CHUNK_SIZE) {
throw new Error("HDLC frame would be too long");
}
const hdlcFrame = {
// alloc to max possible size (as if each byte needs escaping)
data: Buffer.alloc(Math.min(buffer.byteLength * 2 + 6, exports.HDLC_TX_CHUNK_SIZE)),
length: 0,
fcs: HDLC_INIT_FCS,
};
hdlcFrame.data[hdlcFrame.length] = 126 /* HdlcReservedByte.FLAG */;
hdlcFrame.length += 1;
for (const aByte of buffer) {
hdlcFrame.length = encodeByte(hdlcFrame, aByte, hdlcFrame.length);
}
let fcs = hdlcFrame.fcs;
fcs ^= HDLC_INIT_FCS;
hdlcFrame.length = encodeByte(hdlcFrame, fcs & 0xff, hdlcFrame.length);
hdlcFrame.length = encodeByte(hdlcFrame, (fcs >> 8) & 0xff, hdlcFrame.length);
hdlcFrame.data[hdlcFrame.length] = 126 /* HdlcReservedByte.FLAG */;
hdlcFrame.length += 1;
return hdlcFrame;
}
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