dns: improve setServers() errors and performance · nodejs/node@65b9c42

// servers cares won't have any servers available for resolution

const orig = this._handle.getServers();

const newSet = [];

const IPv6RE = /\[(.*)\]/;

const IPv6RE = /^\[([^[\]]*)\]/;

const addrSplitRE = /(^.+?)(?::(\d+))?$/;

servers.forEach((serv) => {

}

}

const [, s, p] = serv.match(addrSplitRE);

ipVersion = isIP(s);

// addr::port

const addrSplitMatch = serv.match(addrSplitRE);

if (addrSplitMatch) {

const hostIP = addrSplitMatch[1];

const port = addrSplitMatch[2] || IANA_DNS_PORT;

if (ipVersion !== 0) {

return newSet.push([ipVersion, s, parseInt(p)]);

ipVersion = isIP(hostIP);

if (ipVersion !== 0) {

return newSet.push([ipVersion, hostIP, parseInt(port)]);

}

}

throw new ERR_INVALID_IP_ADDRESS(serv);

]);

}

{

// Various invalidities, all of which should throw a clean error.

const invalidServers = [

' ',

'\n',

'\0',

'1'.repeat(3 * 4),

// Check for REDOS issues.

':'.repeat(100000),

'['.repeat(100000),

'['.repeat(100000) + ']'.repeat(100000) + 'a'

];

invalidServers.forEach((serv) => {

assert.throws(

() => {

dns.setServers([serv]);

},

{

name: 'TypeError [ERR_INVALID_IP_ADDRESS]',

code: 'ERR_INVALID_IP_ADDRESS'

}

);

});

}

const goog = [

'8.8.8.8',

'8.8.4.4',