http: add IPv6 range support for NO_PROXY environment variable

Author: haramj

doc/api/http.md

@@ -4371,6 +4371,8 @@ The `NO_PROXY` environment variable supports several formats:
 * `*.example.com` - Wildcard domain match
 * `192.168.1.100` - Exact IP address match
 * `192.168.1.1-192.168.1.100` - IP address range
+* `::1` or `[::1]` - Exact IPv6 address match
+* `::1-::100` - IPv6 address range
 * `example.com:8080` - Hostname with specific port
 
 Multiple entries should be separated by commas.

lib/internal/http.js

@@ -1,6 +1,8 @@
 'use strict';
 
 const {
+  Array,
+  BigInt,
   Date,
   NumberParseInt,
   Symbol,
@@ -16,7 +18,7 @@ const {
 
 const { URL } = require('internal/url');
 const { Buffer } = require('buffer');
-const { isIPv4 } = require('internal/net');
+const { isIPv4, isIPv6 } = require('internal/net');
 const { ERR_PROXY_INVALID_CONFIG } = require('internal/errors').codes;
 let utcCache;
 
@@ -67,6 +69,35 @@ function ipToInt(ip) {
   return result >>> 0;
 }
 
+function ipv6ToBigInt(ip) {
+  const cleanIp = ip.startsWith('[') ? ip.slice(1, -1) : ip;
+
+  const parts = cleanIp.split('::');
+  let left = parts[0];
+  let right = parts[1] || '';
+
+  if (parts.length === 2) {
+    const leftParts = left.split(':').filter((p) => p.length > 0);
+    const rightParts = right.split(':').filter((p) => p.length > 0);
+    const missingParts = 8 - leftParts.length - rightParts.length;
+
+    left = leftParts.join(':');
+    right = Array(missingParts).fill('0').join(':') + (right ? ':' + rightParts.join(':') : '');
+  }
+
+  const fullAddress = (left + (right ? ':' + right : '')).replace(/^:|:$/g, '');
+  const hexParts = fullAddress.split(':');
+
+  let result = BigInt(0);
+  for (const hexVal of hexParts) {
+    if (hexVal) {
+      result = (result << BigInt(16)) + BigInt('0x' + hexVal);
+    }
+  }
+
+  return result;
+}
+
 // There are two factors in play when proxying the request:
 // 1. What the request protocol is, that is, whether users are sending it via
 //    http.request or https.request, or whether they are sending
@@ -162,15 +193,20 @@ class ProxyConfig {
 
       // Handle IP ranges (simple format like 192.168.1.0-192.168.1.255)
       // TODO(joyeecheung): support IPv6.
-      if (entry.includes('-') && isIPv4(host)) {
+      if (entry.includes('-')) {
         let { 0: startIP, 1: endIP } = entry.split('-');
         startIP = startIP.trim();
         endIP = endIP.trim();
-        if (startIP && endIP && isIPv4(startIP) && isIPv4(endIP)) {
+        if (isIPv4(startIP) && isIPv4(endIP) && isIPv4(host)) {
           const hostInt = ipToInt(host);
           const startInt = ipToInt(startIP);
           const endInt = ipToInt(endIP);
           if (hostInt >= startInt && hostInt <= endInt) return false;
+        } else if (isIPv6(startIP) && isIPv6(endIP) && isIPv6(host)) {
+          const hostInt = ipv6ToBigInt(host);
+          const startInt = ipv6ToBigInt(startIP);
+          const endInt = ipv6ToBigInt(endIP);
+          if (hostInt >= startInt && hostInt <= endInt) return false;
         }
       }
 

test/client-proxy/test-http-proxy-request-no-proxy-ipv6.mjs

@@ -0,0 +1,75 @@
+// This tests that NO_PROXY environment variable supports IPv6 ranges.
+
+import * as common from '../common/index.mjs';
+import assert from 'node:assert';
+import { once } from 'events';
+import http from 'node:http';
+import { runProxiedRequest } from '../common/proxy-server.js';
+
+// Start a server to process the final request.
+const server = http.createServer(common.mustCall((req, res) => {
+  res.writeHead(200, { 'Content-Type': 'text/plain' });
+  res.end('Hello IPv6\n');
+}, 1));
+server.on('error', common.mustNotCall((err) => { console.error('Server error', err); }));
+server.listen(0, '::1');
+await once(server, 'listening');
+
+// Start a proxy server that should be used.
+const proxy = http.createServer(common.mustCall((req, res) => {
+  res.writeHead(200, { 'Content-Type': 'text/plain' });
+  res.end('Proxied Hello IPv6\n');
+}, 2));
+proxy.listen(0, '::1');
+await once(proxy, 'listening');
+
+// Test NO_PROXY with IPv6 range (::1-::100 includes ::1)
+{
+  const { code, signal, stderr, stdout } = await runProxiedRequest({
+    NODE_USE_ENV_PROXY: 1,
+    REQUEST_URL: `http://[::1]:${server.address().port}/test`,
+    HTTP_PROXY: `http://[::1]:${proxy.address().port}`,
+    NO_PROXY: '::1-::100',
+  });
+  // The request should succeed and bypass proxy
+  assert.match(stdout, /Status Code: 200/);
+  assert.match(stdout, /Hello IPv6/);
+  assert.strictEqual(stderr.trim(), '');
+  assert.strictEqual(code, 0);
+  assert.strictEqual(signal, null);
+}
+
+// Test another IPv6 address within the range (::50)
+{
+  const { code, signal, stderr, stdout } = await runProxiedRequest({
+    NODE_USE_ENV_PROXY: 1,
+    REQUEST_URL: `http://[::1]:${server.address().port}/test`,
+    HTTP_PROXY: `http://localhost:${proxy.address().port}`,
+    NO_PROXY: '::50-::100',
+  });
+  // The request should succeed and bypass proxy
+  assert.match(stdout, /Status Code: 200/);
+  assert.match(stdout, /Hello IPv6/);
+  assert.strictEqual(stderr.trim(), '');
+  assert.strictEqual(code, 0);
+  assert.strictEqual(signal, null);
+}
+
+// Test NO_PROXY with an IPv6 address outside the range (::200)
+{
+  const { code, signal, stderr, stdout } = await runProxiedRequest({
+    NODE_USE_ENV_PROXY: 1,
+    REQUEST_URL: `http://[::200]:${server.address().port}/test`,
+    HTTP_PROXY: `http://[::1]:${proxy.address().port}`,
+    NO_PROXY: '::1-::100',
+  });
+  // The request should be proxied
+  assert.match(stdout, /Status Code: 200/);
+  assert.match(stdout, /Proxied Hello IPv6/);
+  assert.strictEqual(stderr.trim(), '');
+  assert.strictEqual(code, 0);
+  assert.strictEqual(signal, null);
+}
+
+proxy.close();
+server.close();