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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/* globals ctypes */
// We are in a worker, wait for our message then execute the wanted method.
// These constants are luckily shared, but with different names
const NS_T_TXT = 16; // DNS_TYPE_TXT
const NS_T_SRV = 33; // DNS_TYPE_SRV
const NS_T_MX = 15; // DNS_TYPE_MX
/**
* DNS API for *nix.
*/
class load_libresolv {
library = null;
constructor(os) {
this._open(os);
}
/**
* Tries to find and load library.
*
* @param {string} os - Operating System.
*/
_open(os) {
function findLibrary() {
let lastException = null;
let candidates = [];
if (os == "FreeBSD") {
candidates = [{ name: "c", suffix: ".7" }];
} else if (os == "OpenBSD") {
candidates = [{ name: "c", suffix: "" }];
} else {
candidates = [
{ name: "resolv.9", suffix: "" },
{ name: "resolv", suffix: ".2" },
{ name: "resolv", suffix: "" },
];
}
const tried = [];
for (const candidate of candidates) {
try {
const libName = ctypes.libraryName(candidate.name) + candidate.suffix;
tried.push(libName);
return ctypes.open(libName);
} catch (ex) {
lastException = ex;
}
}
throw new Error(`Couldn't find libresolv; tried: ${tried}`, {
cause: lastException,
});
}
/**
* Declaring functions to be able to call them.
*
* @param {string[]} aSymbolNames - OS function names.
* @param {*} aArgs - Arguments to the call.
*/
function declare(aSymbolNames, ...aArgs) {
let lastException = null;
if (!Array.isArray(aSymbolNames)) {
aSymbolNames = [aSymbolNames];
}
for (const symbolName of aSymbolNames) {
try {
return library.declare(symbolName, ...aArgs);
} catch (ex) {
lastException = ex;
}
}
library.close();
throw new Error(`Failed to declare: ${aSymbolNames}`, {
cause: lastException,
});
}
const library = (this.library = findLibrary());
this.res_search = declare(
["res_9_search", "res_search", "__res_search"],
ctypes.default_abi,
ctypes.int,
ctypes.char.ptr,
ctypes.int,
ctypes.int,
ctypes.unsigned_char.ptr,
ctypes.int
);
this.res_query = declare(
["res_9_query", "res_query", "__res_query"],
ctypes.default_abi,
ctypes.int,
ctypes.char.ptr,
ctypes.int,
ctypes.int,
ctypes.unsigned_char.ptr,
ctypes.int
);
this.dn_expand = declare(
["res_9_dn_expand", "dn_expand", "__dn_expand"],
ctypes.default_abi,
ctypes.int,
ctypes.unsigned_char.ptr,
ctypes.unsigned_char.ptr,
ctypes.unsigned_char.ptr,
ctypes.char.ptr,
ctypes.int
);
this.dn_skipname = declare(
["res_9_dn_skipname", "dn_skipname", "__dn_skipname"],
ctypes.default_abi,
ctypes.int,
ctypes.unsigned_char.ptr,
ctypes.unsigned_char.ptr
);
this.ns_get16 = declare(
["res_9_ns_get16", "ns_get16", "_getshort"],
ctypes.default_abi,
ctypes.unsigned_int,
ctypes.unsigned_char.ptr
);
this.ns_get32 = declare(
["res_9_ns_get32", "ns_get32", "_getlong"],
ctypes.default_abi,
ctypes.unsigned_long,
ctypes.unsigned_char.ptr
);
this.QUERYBUF_SIZE = 1024;
this.NS_MAXCDNAME = 255;
this.NS_HFIXEDSZ = 12;
this.NS_QFIXEDSZ = 4;
this.NS_RRFIXEDSZ = 10;
this.NS_C_IN = 1;
}
close() {
this.library.close();
this.library = null;
}
/**
* Maps record to SRVRecord, TXTRecord, or MXRecord according to aTypeID and
* returns it.
*
* @param {integer} aTypeID - Type, like NS_T_MX/NS_T_SRV/NS_T_MX.
* @param {string} aAnswer - Data.
* @param {index} aIdx - Size, e.g. NS_HFIXEDSZ.
* @param {integer} aLength - Data length.
* @returns {SRVRecord|TXTRecord|MXRecord}
*/
_mapAnswer(aTypeID, aAnswer, aIdx, aLength) {
if (aTypeID == NS_T_SRV) {
const prio = this.ns_get16(aAnswer.addressOfElement(aIdx));
const weight = this.ns_get16(aAnswer.addressOfElement(aIdx + 2));
const port = this.ns_get16(aAnswer.addressOfElement(aIdx + 4));
const hostbuf = ctypes.char.array(this.NS_MAXCDNAME)();
const hostlen = this.dn_expand(
aAnswer.addressOfElement(0),
aAnswer.addressOfElement(aLength),
aAnswer.addressOfElement(aIdx + 6),
hostbuf,
this.NS_MAXCDNAME
);
const host = hostlen > -1 ? hostbuf.readString() : null;
return new SRVRecord(prio, weight, host, port);
}
if (aTypeID == NS_T_TXT) {
// TODO should only read dataLength characters.
const data = ctypes.unsigned_char.ptr(aAnswer.addressOfElement(aIdx + 1));
return new TXTRecord(data.readString());
}
if (aTypeID == NS_T_MX) {
const prio = this.ns_get16(aAnswer.addressOfElement(aIdx));
const hostbuf = ctypes.char.array(this.NS_MAXCDNAME)();
const hostlen = this.dn_expand(
aAnswer.addressOfElement(0),
aAnswer.addressOfElement(aLength),
aAnswer.addressOfElement(aIdx + 2),
hostbuf,
this.NS_MAXCDNAME
);
const host = hostlen > -1 ? hostbuf.readString() : null;
return new MXRecord(prio, host);
}
return null;
}
/**
* Performs a DNS query for aTypeID on a certain address (aName) and returns
* array of records of aTypeID.
*
* @param {string} aName - Address.
* @param {integer} aTypeID - Type, like NS_T_MX/NS_T_SRV/NS_T_MX.
* @returns {SRVRecord[]|TXTRecord[]|MXRecord[]}
*/
lookup(aName, aTypeID) {
const qname = ctypes.char.array()(aName);
const answer = ctypes.unsigned_char.array(this.QUERYBUF_SIZE)();
const length = this.res_search(
qname,
this.NS_C_IN,
aTypeID,
answer,
this.QUERYBUF_SIZE
);
// There is an error.
if (length < 0) {
return [];
}
const results = [];
let idx = this.NS_HFIXEDSZ;
const qdcount = this.ns_get16(answer.addressOfElement(4));
const ancount = this.ns_get16(answer.addressOfElement(6));
for (let qdidx = 0; qdidx < qdcount && idx < length; qdidx++) {
idx +=
this.NS_QFIXEDSZ +
this.dn_skipname(
answer.addressOfElement(idx),
answer.addressOfElement(length)
);
}
for (let anidx = 0; anidx < ancount && idx < length; anidx++) {
idx += this.dn_skipname(
answer.addressOfElement(idx),
answer.addressOfElement(length)
);
const rridx = idx;
const type = this.ns_get16(answer.addressOfElement(rridx));
const dataLength = this.ns_get16(answer.addressOfElement(rridx + 8));
idx += this.NS_RRFIXEDSZ;
if (type === aTypeID) {
const resource = this._mapAnswer(aTypeID, answer, idx, length);
resource.type = type;
resource.nsclass = this.ns_get16(answer.addressOfElement(rridx + 2));
resource.ttl = this.ns_get32(answer.addressOfElement(rridx + 4)) | 0;
results.push(resource);
}
idx += dataLength;
}
return results;
}
}
/**
* DNS API for Windows.
*/
class load_dnsapi {
library = null;
constructor() {
this._open();
}
/**
* Tries to find and load library.
*/
_open() {
function declare(aSymbolName, ...aArgs) {
try {
return library.declare(aSymbolName, ...aArgs);
} catch (ex) {
throw new Error(`Failed to declare: ${aSymbolName}`, { cause: ex });
}
}
const library = (this.library = ctypes.open(ctypes.libraryName("DnsAPI")));
this.DNS_SRV_DATA = ctypes.StructType("DNS_SRV_DATA", [
{ pNameTarget: ctypes.jschar.ptr },
{ wPriority: ctypes.unsigned_short },
{ wWeight: ctypes.unsigned_short },
{ wPort: ctypes.unsigned_short },
{ Pad: ctypes.unsigned_short },
]);
this.DNS_TXT_DATA = ctypes.StructType("DNS_TXT_DATA", [
{ dwStringCount: ctypes.unsigned_long },
{ pStringArray: ctypes.jschar.ptr.array(1) },
]);
this.DNS_MX_DATA = ctypes.StructType("DNS_MX_DATA", [
{ pNameTarget: ctypes.jschar.ptr },
{ wPriority: ctypes.unsigned_short },
{ Pad: ctypes.unsigned_short },
]);
this.DNS_RECORD = ctypes.StructType("_DnsRecord");
this.DNS_RECORD.define([
{ pNext: this.DNS_RECORD.ptr },
{ pName: ctypes.jschar.ptr },
{ wType: ctypes.unsigned_short },
{ wDataLength: ctypes.unsigned_short },
{ Flags: ctypes.unsigned_long },
{ dwTtl: ctypes.unsigned_long },
{ dwReserved: ctypes.unsigned_long },
{ Data: this.DNS_SRV_DATA }, // it's a union, can be cast to many things
]);
this.PDNS_RECORD = ctypes.PointerType(this.DNS_RECORD);
this.DnsQuery_W = declare(
"DnsQuery_W",
ctypes.winapi_abi,
ctypes.long,
ctypes.jschar.ptr,
ctypes.unsigned_short,
ctypes.unsigned_long,
ctypes.voidptr_t,
this.PDNS_RECORD.ptr,
ctypes.voidptr_t.ptr
);
this.DnsRecordListFree = declare(
"DnsRecordListFree",
ctypes.winapi_abi,
ctypes.void_t,
this.PDNS_RECORD,
ctypes.int
);
this.ERROR_SUCCESS = ctypes.Int64(0);
this.DNS_QUERY_STANDARD = 0;
this.DnsFreeRecordList = 1;
}
close() {
this.library.close();
this.library = null;
}
/**
* Maps record to SRVRecord, TXTRecord, or MXRecord according to aTypeID and
* returns it.
*
* @param {integer} aTypeID - Type, like NS_T_MX/NS_T_SRV/NS_T_MX.
* @param {object} aData - Raw data to map to a specific type.
* @returns {SRVRecord|TXTRecord|MXRecord}
*/
_mapAnswer(aTypeID, aData) {
if (aTypeID == NS_T_SRV) {
const srvdata = ctypes.cast(aData, this.DNS_SRV_DATA);
return new SRVRecord(
srvdata.wPriority,
srvdata.wWeight,
srvdata.pNameTarget.readString(),
srvdata.wPort
);
}
if (aTypeID == NS_T_TXT) {
const txtdata = ctypes.cast(aData, this.DNS_TXT_DATA);
if (txtdata.dwStringCount > 0) {
return new TXTRecord(txtdata.pStringArray[0].readString());
}
}
if (aTypeID == NS_T_MX) {
const mxdata = ctypes.cast(aData, this.DNS_MX_DATA);
return new MXRecord(mxdata.wPriority, mxdata.pNameTarget.readString());
}
return null;
}
/**
* Performs a DNS query for aTypeID on a certain address (aName) and returns
* array of records of aTypeID (e.g. SRVRecord, TXTRecord, or MXRecord).
*
* @param {string} aName - Address.
* @param {integer} aTypeID - Type, like NS_T_MX/NS_T_SRV/NS_T_MX.
* @returns {SRVRecord[]|TXTRecord[]|MXRecord[]}
*/
lookup(aName, aTypeID) {
const queryResultsSet = this.PDNS_RECORD();
const qname = ctypes.jschar.array()(aName);
const dnsStatus = this.DnsQuery_W(
qname,
aTypeID,
this.DNS_QUERY_STANDARD,
null,
queryResultsSet.address(),
null
);
// There is an error.
if (ctypes.Int64.compare(dnsStatus, this.ERROR_SUCCESS) != 0) {
return [];
}
const results = [];
for (
let presult = queryResultsSet;
presult && !presult.isNull();
presult = presult.contents.pNext
) {
const result = presult.contents;
if (result.wType == aTypeID) {
const resource = this._mapAnswer(aTypeID, result.Data);
resource.type = result.wType;
resource.nsclass = 0;
resource.ttl = result.dwTtl | 0;
results.push(resource);
}
}
this.DnsRecordListFree(queryResultsSet, this.DnsFreeRecordList);
return results;
}
}
/**
* Represents and SRV record.
* Used to make results of different libraries consistent for SRV queries.
*
* @param {integer} prio
* @param {integer} weight
* @param {string} host
* @param {?integer} port
*/
function SRVRecord(prio, weight, host, port) {
this.prio = prio;
this.weight = weight;
this.host = host.toLowerCase();
this.port = port;
}
/**
* Represents a TXT record.
* Used to make results of different libraries consistent for TXT queries.
*
* @param {string} data
*/
function TXTRecord(data) {
this.data = data;
}
/**
* Represents an MX record.
* Used to make results of different libraries consistent for MX queries.
*
* @param {integer} prio
* @param {string} host
*/
function MXRecord(prio, host) {
this.prio = prio;
this.host = host.toLowerCase();
}
const worker = new PromiseWorker.AbstractWorker();
worker.dispatch = (method, args = []) => {
return worker[method](...args); // Call worker.execute()
};
worker.execute = (os, method, args) => {
const DNS = os == "WINNT" ? new load_dnsapi() : new load_libresolv(os);
return DNS[method].apply(DNS, args);
};
worker.postMessage = function (...args) {
self.postMessage(...args);
};
worker.close = function () {
self.close();
};
self.addEventListener("message", msg => worker.handleMessage(msg));