dns: add order option and support ipv6first

PR-URL: #52492
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>

doc/api/cli.md

@@ -588,16 +588,20 @@ added:
   - v16.4.0
   - v14.18.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52492
+    description: The `ipv6first` is supported now.
   - version: v17.0.0
     pr-url: https://github.com/nodejs/node/pull/39987
     description: Changed default value to `verbatim`.
 -->
 
-Set the default value of `verbatim` in [`dns.lookup()`][] and
+Set the default value of `order` in [`dns.lookup()`][] and
 [`dnsPromises.lookup()`][]. The value could be:
 
-* `ipv4first`: sets default `verbatim` `false`.
-* `verbatim`: sets default `verbatim` `true`.
+* `ipv4first`: sets default `order` to `ipv4first`.
+* `ipv6first`: sets default `order` to `ipv6first`.
+* `verbatim`: sets default `order` to `verbatim`.
 
 The default is `verbatim` and [`dns.setDefaultResultOrder()`][] have higher
 priority than `--dns-result-order`.

doc/api/dns.md

@@ -179,6 +179,9 @@ section if a custom port is used.
 <!-- YAML
 added: v0.1.90
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52492
+    description: The `verbatim` option is now deprecated in favor of the new `order` option.
   - version: v18.4.0
     pr-url: https://github.com/nodejs/node/pull/43054
     description: For compatibility with `node:net`, when passing an option
@@ -211,9 +214,18 @@ changes:
     flags may be passed by bitwise `OR`ing their values.
   * `all` {boolean} When `true`, the callback returns all resolved addresses in
     an array. Otherwise, returns a single address. **Default:** `false`.
+  * `order` {string} When `verbatim`, the resolved addresses are return
+    unsorted. When `ipv4first`, the resolved addresses are sorted by placing
+    IPv4 addresses before IPv6 addresses. When `ipv6first`, the resolved
+    addresses are sorted by placing IPv6 addresses before IPv4 addresses.
+    **Default:** `verbatim` (addresses are not reordered).
+    Default value is configurable using [`dns.setDefaultResultOrder()`][] or
+    [`--dns-result-order`][].
   * `verbatim` {boolean} When `true`, the callback receives IPv4 and IPv6
     addresses in the order the DNS resolver returned them. When `false`,
     IPv4 addresses are placed before IPv6 addresses.
+    This option will be deprecated in favor of `order`. When both are specified,
+    `order` has higher precedence. New code should only use `order`.
     **Default:** `true` (addresses are not reordered). Default value is
     configurable using [`dns.setDefaultResultOrder()`][] or
     [`--dns-result-order`][].
@@ -775,18 +787,22 @@ added:
   - v16.4.0
   - v14.18.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52492
+    description: The `ipv6first` value is supported now.
   - version: v17.0.0
     pr-url: https://github.com/nodejs/node/pull/39987
     description: Changed default value to `verbatim`.
 -->
 
-* `order` {string} must be `'ipv4first'` or `'verbatim'`.
+* `order` {string} must be `'ipv4first'`, `'ipv6first'` or `'verbatim'`.
 
-Set the default value of `verbatim` in [`dns.lookup()`][] and
+Set the default value of `order` in [`dns.lookup()`][] and
 [`dnsPromises.lookup()`][]. The value could be:
 
-* `ipv4first`: sets default `verbatim` `false`.
-* `verbatim`: sets default `verbatim` `true`.
+* `ipv4first`: sets default `order` to `ipv4first`.
+* `ipv6first`: sets default `order` to `ipv6first`.
+* `verbatim`: sets default `order` to `verbatim`.
 
 The default is `verbatim` and [`dns.setDefaultResultOrder()`][] have higher
 priority than [`--dns-result-order`][]. When using [worker threads][],
@@ -796,14 +812,21 @@ dns orders in workers.
 ## `dns.getDefaultResultOrder()`
 
 <!-- YAML
-added: v20.1.0
+added:
+  - v20.1.0
+  - v18.17.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52492
+    description: The `ipv6first` value is supported now.
 -->
 
-Get the default value for `verbatim` in [`dns.lookup()`][] and
+Get the default value for `order` in [`dns.lookup()`][] and
 [`dnsPromises.lookup()`][]. The value could be:
 
-* `ipv4first`: for `verbatim` defaulting to `false`.
-* `verbatim`: for `verbatim` defaulting to `true`.
+* `ipv4first`: for `order` defaulting to `ipv4first`.
+* `ipv6first`: for `order` defaulting to `ipv6first`.
+* `verbatim`: for `order` defaulting to `verbatim`.
 
 ## `dns.setServers(servers)`
 
@@ -947,6 +970,10 @@ section if a custom port is used.
 
 <!-- YAML
 added: v10.6.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52492
+    description: The `verbatim` option is now deprecated in favor of the new `order` option.
 -->
 
 * `hostname` {string}
@@ -959,13 +986,22 @@ added: v10.6.0
     flags may be passed by bitwise `OR`ing their values.
   * `all` {boolean} When `true`, the `Promise` is resolved with all addresses in
     an array. Otherwise, returns a single address. **Default:** `false`.
+  * `order` {string} When `verbatim`, the `Promise` is resolved with IPv4 and
+    IPv6 addresses in the order the DNS resolver returned them. When `ipv4first`,
+    IPv4 addresses are placed before IPv6 addresses. When `ipv6first`,
+    IPv6 addresses are placed before IPv4 addresses.
+    **Default:** `verbatim` (addresses are not reordered).
+    Default value is configurable using [`dns.setDefaultResultOrder()`][] or
+    [`--dns-result-order`][]. New code should use `{ order: 'verbatim' }`.
   * `verbatim` {boolean} When `true`, the `Promise` is resolved with IPv4 and
     IPv6 addresses in the order the DNS resolver returned them. When `false`,
     IPv4 addresses are placed before IPv6 addresses.
+    This option will be deprecated in favor of `order`. When both are specified,
+    `order` has higher precedence. New code should only use `order`.
     **Default:** currently `false` (addresses are reordered) but this is
     expected to change in the not too distant future. Default value is
     configurable using [`dns.setDefaultResultOrder()`][] or
-    [`--dns-result-order`][]. New code should use `{ verbatim: true }`.
+    [`--dns-result-order`][].
 
 Resolves a host name (e.g. `'nodejs.org'`) into the first found A (IPv4) or
 AAAA (IPv6) record. All `option` properties are optional. If `options` is an
@@ -1347,18 +1383,22 @@ added:
   - v16.4.0
   - v14.18.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/52492
+    description: The `ipv6first` value is supported now.
   - version: v17.0.0
     pr-url: https://github.com/nodejs/node/pull/39987
     description: Changed default value to `verbatim`.
 -->
 
-* `order` {string} must be `'ipv4first'` or `'verbatim'`.
+* `order` {string} must be `'ipv4first'`, `'ipv6first'` or `'verbatim'`.
 
-Set the default value of `verbatim` in [`dns.lookup()`][] and
+Set the default value of `order` in [`dns.lookup()`][] and
 [`dnsPromises.lookup()`][]. The value could be:
 
-* `ipv4first`: sets default `verbatim` `false`.
-* `verbatim`: sets default `verbatim` `true`.
+* `ipv4first`: sets default `order` to `ipv4first`.
+* `ipv6first`: sets default `order` to `ipv6first`.
+* `verbatim`: sets default `order` to `verbatim`.
 
 The default is `verbatim` and [`dnsPromises.setDefaultResultOrder()`][] have
 higher priority than [`--dns-result-order`][]. When using [worker threads][],

lib/dns.js

@@ -43,7 +43,6 @@ const {
   setDefaultResolver,
   validateHints,
   emitInvalidHostnameWarning,
-  getDefaultVerbatim,
   getDefaultResultOrder,
   setDefaultResultOrder,
   errorCodes: dnsErrorCodes,
@@ -89,6 +88,9 @@ const {
 const {
   GetAddrInfoReqWrap,
   GetNameInfoReqWrap,
+  DNS_ORDER_VERBATIM,
+  DNS_ORDER_IPV4_FIRST,
+  DNS_ORDER_IPV6_FIRST,
 } = cares;
 
 const kPerfHooksDnsLookupContext = Symbol('kPerfHooksDnsLookupContext');
@@ -141,7 +143,7 @@ function lookup(hostname, options, callback) {
   let hints = 0;
   let family = 0;
   let all = false;
-  let verbatim = getDefaultVerbatim();
+  let dnsOrder = getDefaultResultOrder();
 
   // Parse arguments
   if (hostname) {
@@ -187,7 +189,11 @@ function lookup(hostname, options, callback) {
     }
     if (options?.verbatim != null) {
       validateBoolean(options.verbatim, 'options.verbatim');
-      verbatim = options.verbatim;
+      dnsOrder = options.verbatim ? 'verbatim' : 'ipv4first';
+    }
+    if (options?.order != null) {
+      validateOneOf(options.order, 'options.order', ['ipv4first', 'ipv6first', 'verbatim']);
+      dnsOrder = options.dnsOrder;
     }
   }
 
@@ -218,8 +224,16 @@ function lookup(hostname, options, callback) {
   req.hostname = hostname;
   req.oncomplete = all ? onlookupall : onlookup;
 
+  let order = DNS_ORDER_VERBATIM;
+
+  if (dnsOrder === 'ipv4first') {
+    order = DNS_ORDER_IPV4_FIRST;
+  } else if (dnsOrder === 'ipv6first') {
+    order = DNS_ORDER_IPV6_FIRST;
+  }
+
   const err = cares.getaddrinfo(
-    req, hostname, family, hints, verbatim,
+    req, hostname, family, hints, order,
   );
   if (err) {
     process.nextTick(callback, new DNSException(err, 'getaddrinfo', hostname));
@@ -230,8 +244,10 @@ function lookup(hostname, options, callback) {
       hostname,
       family,
       hints,
-      verbatim,
+      verbatim: order === DNS_ORDER_VERBATIM,
+      order: dnsOrder,
     };
+
     startPerf(req, kPerfHooksDnsLookupContext, { type: 'dns', name: 'lookup', detail });
   }
   return req;

lib/internal/dns/promises.js

@@ -12,7 +12,6 @@ const {
   createResolverClass,
   validateHints,
   emitInvalidHostnameWarning,
-  getDefaultVerbatim,
   errorCodes: dnsErrorCodes,
   getDefaultResultOrder,
   setDefaultResultOrder,
@@ -53,6 +52,9 @@ const {
   GetAddrInfoReqWrap,
   GetNameInfoReqWrap,
   QueryReqWrap,
+  DNS_ORDER_VERBATIM,
+  DNS_ORDER_IPV4_FIRST,
+  DNS_ORDER_IPV6_FIRST,
 } = internalBinding('cares_wrap');
 const {
   ERR_INVALID_ARG_TYPE,
@@ -120,13 +122,13 @@ function onlookupall(err, addresses) {
  * @param {boolean} all - Whether to resolve with all IP addresses for the hostname.
  * @param {number} hints - One or more supported getaddrinfo flags (supply multiple via
  * bitwise OR).
- * @param {boolean} verbatim - Whether to use the hostname verbatim.
+ * @param {number} dnsOrder - How to sort results. Must be `ipv4first`, `ipv6first` or `verbatim`.
  * @returns {Promise<DNSLookupResult | DNSLookupResult[]>} The IP address(es) of the hostname.
  * @typedef {object} DNSLookupResult
  * @property {string} address - The IP address.
  * @property {0 | 4 | 6} family - The IP address type. 4 for IPv4 or 6 for IPv6, or 0 (for both).
  */
-function createLookupPromise(family, hostname, all, hints, verbatim) {
+function createLookupPromise(family, hostname, all, hints, dnsOrder) {
   return new Promise((resolve, reject) => {
     if (!hostname) {
       emitInvalidHostnameWarning(hostname);
@@ -150,7 +152,15 @@ function createLookupPromise(family, hostname, all, hints, verbatim) {
     req.resolve = resolve;
     req.reject = reject;
 
-    const err = getaddrinfo(req, hostname, family, hints, verbatim);
+    let order = DNS_ORDER_VERBATIM;
+
+    if (dnsOrder === 'ipv4first') {
+      order = DNS_ORDER_IPV4_FIRST;
+    } else if (dnsOrder === 'ipv6first') {
+      order = DNS_ORDER_IPV6_FIRST;
+    }
+
+    const err = getaddrinfo(req, hostname, family, hints, order);
 
     if (err) {
       reject(new DNSException(err, 'getaddrinfo', hostname));
@@ -159,7 +169,8 @@ function createLookupPromise(family, hostname, all, hints, verbatim) {
         hostname,
         family,
         hints,
-        verbatim,
+        verbatim: order === DNS_ORDER_VERBATIM,
+        order: dnsOrder,
       };
       startPerf(req, kPerfHooksDnsLookupContext, { type: 'dns', name: 'lookup', detail });
     }
@@ -175,14 +186,15 @@ const validFamilies = [0, 4, 6];
  * @param {0 | 4 | 6} [options.family=0] - The record family. Must be 4, 6, or 0 (for both).
  * @param {number} [options.hints] - One or more supported getaddrinfo flags (supply multiple via
  * bitwise OR).
- * @param {boolean} [options.verbatim=false] - Return results in same order DNS resolved them;
- * otherwise IPv4 then IPv6. New code should supply `true`.
+ * @param {string} [options.order='verbatim'] - Return results in same order DNS resolved them;
+ * Must be `ipv4first`, `ipv6first` or `verbatim`.
+ * New code should supply `verbatim`.
  */
 function lookup(hostname, options) {
   let hints = 0;
   let family = 0;
   let all = false;
-  let verbatim = getDefaultVerbatim();
+  let dnsOrder = getDefaultResultOrder();
 
   // Parse arguments
   if (hostname) {
@@ -210,11 +222,15 @@ function lookup(hostname, options) {
     }
     if (options?.verbatim != null) {
       validateBoolean(options.verbatim, 'options.verbatim');
-      verbatim = options.verbatim;
+      dnsOrder = options.verbatim ? 'verbatim' : 'ipv4first';
+    }
+    if (options?.order != null) {
+      validateOneOf(options.order, 'options.order', ['ipv4first', 'ipv6first', 'verbatim']);
+      dnsOrder = options.order;
     }
   }
 
-  return createLookupPromise(family, hostname, all, hints, verbatim);
+  return createLookupPromise(family, hostname, all, hints, dnsOrder);
 }
 
 

lib/internal/dns/utils.js

@@ -207,6 +207,7 @@ function initializeDns() {
     dnsOrder ??= 'verbatim';
   } else {
     // Allow the deserialized application to override order from CLI.
+    validateOneOf(orderFromCLI, '--dns-result-order', ['verbatim', 'ipv4first', 'ipv6first']);
     dnsOrder = orderFromCLI;
   }
 
@@ -277,12 +278,8 @@ function emitInvalidHostnameWarning(hostname) {
   }
 }
 
-function getDefaultVerbatim() {
-  return dnsOrder !== 'ipv4first';
-}
-
 function setDefaultResultOrder(value) {
-  validateOneOf(value, 'dnsOrder', ['verbatim', 'ipv4first']);
+  validateOneOf(value, 'dnsOrder', ['verbatim', 'ipv4first', 'ipv6first']);
   dnsOrder = value;
 }
 
@@ -351,7 +348,6 @@ module.exports = {
   validateTimeout,
   validateTries,
   emitInvalidHostnameWarning,
-  getDefaultVerbatim,
   getDefaultResultOrder,
   setDefaultResultOrder,
   errorCodes,

lib/internal/modules/esm/fetch_module.js

@@ -253,7 +253,7 @@ async function isLocalAddress(hostname) {
     ) {
       hostname = StringPrototypeSlice(hostname, 1, -1);
     }
-    const addr = await dnsLookup(hostname, { verbatim: true });
+    const addr = await dnsLookup(hostname, { order: 'verbatim' });
     const ipv = addr.family === 4 ? 'ipv4' : 'ipv6';
     return allowList.check(addr.address, ipv);
   } catch {