os: fix netmask format check condition in getCIDR function

Modified to check the format of the netmask instead of just checking that each part of the netmask is even PR-URL: #57324 Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Author: HBSPS

lib/internal/util.js

@@ -9,6 +9,7 @@ const {
  Error,
  ErrorCaptureStackTrace,
  FunctionPrototypeCall,
+ NumberParseInt,
  ObjectDefineProperties,
  ObjectDefineProperty,
  ObjectGetOwnPropertyDescriptor,
@@ -34,7 +35,9 @@ const {
  SafeSet,
  SafeWeakMap,
  SafeWeakRef,
+ StringPrototypeIncludes,
  StringPrototypeReplace,
+ StringPrototypeSlice,
  StringPrototypeToLowerCase,
  StringPrototypeToUpperCase,
  Symbol,
@@ -825,6 +828,59 @@ function setupCoverageHooks(dir) {
  return coverageDirectory;
 }
 
+// Returns the number of ones in the binary representation of the decimal
+// number.
+function countBinaryOnes(n) {
+ // Count the number of bits set in parallel, which is faster than looping
+ n = n - ((n >>> 1) & 0x55555555);
+ n = (n & 0x33333333) + ((n >>> 2) & 0x33333333);
+ return ((n + (n >>> 4) & 0xF0F0F0F) * 0x1010101) >>> 24;
+}
+
+function getCIDR(address, netmask, family) {
+ let ones = 0;
+ let split = '.';
+ let range = 10;
+ let groupLength = 8;
+ let hasZeros = false;
+ let lastPos = 0;
+
+ if (family === 'IPv6') {
+ split = ':';
+ range = 16;
+ groupLength = 16;
+ }
+
+ for (let i = 0; i < netmask.length; i++) {
+ if (netmask[i] !== split) {
+ if (i + 1 < netmask.length) {
+ continue;
+ }
+ i++;
+ }
+ const part = StringPrototypeSlice(netmask, lastPos, i);
+ lastPos = i + 1;
+ if (part !== '') {
+ if (hasZeros) {
+ if (part !== '0') {
+ return null;
+ }
+ } else {
+ const binary = NumberParseInt(part, range);
+ const binaryOnes = countBinaryOnes(binary);
+ ones += binaryOnes;
+ if (binaryOnes !== groupLength) {
+ if (StringPrototypeIncludes(binary.toString(2), '01')) {
+ return null;
+ }
+ hasZeros = true;
+ }
+ }
+ }
+ }
+
+ return `${address}/${ones}`;
+}
 
 const handleTypes = ['TCP', 'TTY', 'UDP', 'FILE', 'PIPE', 'UNKNOWN'];
 function guessHandleType(fd) {
@@ -889,6 +945,7 @@ module.exports = {
  filterDuplicateStrings,
  filterOwnProperties,
  getConstructorOf,
+ getCIDR,
  getCWDURL,
  getInternalGlobal,
  getStructuredStack,

lib/os.js

@@ -24,7 +24,6 @@
 const {
  ArrayPrototypePush,
  Float64Array,
- NumberParseInt,
  ObjectDefineProperties,
  StringPrototypeEndsWith,
  StringPrototypeSlice,
@@ -41,6 +40,7 @@ const {
  },
  hideStackFrames,
 } = require('internal/errors');
+const { getCIDR } = require('internal/util');
 const { validateInt32 } = require('internal/validators');
 
 const {
@@ -208,60 +208,6 @@ function endianness() {
 }
 endianness[SymbolToPrimitive] = () => kEndianness;
 
-// Returns the number of ones in the binary representation of the decimal
-// number.
-function countBinaryOnes(n) {
- // Count the number of bits set in parallel, which is faster than looping
- n = n - ((n >>> 1) & 0x55555555);
- n = (n & 0x33333333) + ((n >>> 2) & 0x33333333);
- return ((n + (n >>> 4) & 0xF0F0F0F) * 0x1010101) >>> 24;
-}
-
-function getCIDR(address, netmask, family) {
- let ones = 0;
- let split = '.';
- let range = 10;
- let groupLength = 8;
- let hasZeros = false;
- let lastPos = 0;
-
- if (family === 'IPv6') {
- split = ':';
- range = 16;
- groupLength = 16;
- }
-
- for (let i = 0; i < netmask.length; i++) {
- if (netmask[i] !== split) {
- if (i + 1 < netmask.length) {
- continue;
- }
- i++;
- }
- const part = StringPrototypeSlice(netmask, lastPos, i);
- lastPos = i + 1;
- if (part !== '') {
- if (hasZeros) {
- if (part !== '0') {
- return null;
- }
- } else {
- const binary = NumberParseInt(part, range);
- const binaryOnes = countBinaryOnes(binary);
- ones += binaryOnes;
- if (binaryOnes !== groupLength) {
- if ((binary & 1) !== 0) {
- return null;
- }
- hasZeros = true;
- }
- }
- }
- }
-
- return `${address}/${ones}`;
-}
-
 /**
  * @returns {Record<string, Array<{
  * address: string,

test/parallel/test-internal-util-getCIDR.js

@@ -0,0 +1,23 @@
+// Flags: --expose-internals
+'use strict';
+require('../common');
+
+// These are tests that verify that the subnetmask is used
+// to create the correct CIDR address.
+// Tests that it returns null if the subnetmask is not in the correct format.
+// (ref: https://www.rfc-editor.org/rfc/rfc1878)
+
+const assert = require('node:assert');
+const { getCIDR } = require('internal/util');
+
+assert.strictEqual(getCIDR('127.0.0.1', '255.0.0.0', 'IPv4'), '127.0.0.1/8');
+assert.strictEqual(getCIDR('127.0.0.1', '255.255.0.0', 'IPv4'), '127.0.0.1/16');
+
+// 242 = 11110010(2)
+assert.strictEqual(getCIDR('127.0.0.1', '242.0.0.0', 'IPv4'), null);
+
+assert.strictEqual(getCIDR('::1', 'ffff:ffff:ffff:ffff::', 'IPv6'), '::1/64');
+assert.strictEqual(getCIDR('::1', 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff', 'IPv6'), '::1/128');
+
+// ff00:ffff = 11111111 00000000 : 11111111 11111111(2)
+assert.strictEqual(getCIDR('::1', 'ffff:ff00:ffff::', 'IPv6'), null);