From 1d6ca80c7e8be42a74852047289e6151b467cffb Mon Sep 17 00:00:00 2001
From: Michael Dokolin <mikhail.dokolin@elastic.co>
Date: Wed, 25 Aug 2021 17:01:24 +0200
Subject: [PATCH] [Data] Fix CIDR mask to avoid using big integers (#109789)
 (#110045)

---
 .../search/aggs/buckets/lib/cidr_mask.ts      | 41 +++++++++----------
 .../search/aggs/utils/ip_address.test.ts      | 15 -------
 .../common/search/aggs/utils/ip_address.ts    | 12 ------
 3 files changed, 19 insertions(+), 49 deletions(-)

diff --git a/src/plugins/data/common/search/aggs/buckets/lib/cidr_mask.ts b/src/plugins/data/common/search/aggs/buckets/lib/cidr_mask.ts
index 93ccbffaeb89..482885861c65 100644
--- a/src/plugins/data/common/search/aggs/buckets/lib/cidr_mask.ts
+++ b/src/plugins/data/common/search/aggs/buckets/lib/cidr_mask.ts
@@ -10,44 +10,41 @@ import ipaddr from 'ipaddr.js';
 import { IpAddress } from '../../utils';
 
 export class CidrMask {
+  private static getNetmask(size: number, prefix: number) {
+    return new Array(size).fill(255).map((byte, index) => {
+      const bytePrefix = 8 - Math.min(Math.max(prefix - index * 8, 0), 8);
+
+      // eslint-disable-next-line no-bitwise
+      return (byte >> bytePrefix) << bytePrefix;
+    });
+  }
+
   private address: number[];
-  private netmask: number;
+  private netmask: number[];
+  private prefix: number;
 
   constructor(cidr: string) {
     try {
-      const [address, netmask] = ipaddr.parseCIDR(cidr);
+      const [address, prefix] = ipaddr.parseCIDR(cidr);
 
       this.address = address.toByteArray();
-      this.netmask = netmask;
+      this.netmask = CidrMask.getNetmask(this.address.length, prefix);
+      this.prefix = prefix;
     } catch {
       throw Error('Invalid CIDR mask: ' + cidr);
     }
   }
 
   private getBroadcastAddress() {
-    /* eslint-disable no-bitwise */
-    const netmask = (1n << BigInt(this.address.length * 8 - this.netmask)) - 1n;
-    const broadcast = this.address.map((byte, index) => {
-      const offset = BigInt(this.address.length - index - 1) * 8n;
-      const mask = Number((netmask >> offset) & 255n);
-
-      return byte | mask;
-    });
-    /* eslint-enable no-bitwise */
+    // eslint-disable-next-line no-bitwise
+    const broadcast = this.address.map((byte, index) => byte | (this.netmask[index] ^ 255));
 
     return new IpAddress(broadcast).toString();
   }
 
   private getNetworkAddress() {
-    /* eslint-disable no-bitwise */
-    const netmask = (1n << BigInt(this.address.length * 8 - this.netmask)) - 1n;
-    const network = this.address.map((byte, index) => {
-      const offset = BigInt(this.address.length - index - 1) * 8n;
-      const mask = Number((netmask >> offset) & 255n) ^ 255;
-
-      return byte & mask;
-    });
-    /* eslint-enable no-bitwise */
+    // eslint-disable-next-line no-bitwise
+    const network = this.address.map((byte, index) => byte & this.netmask[index]);
 
     return new IpAddress(network).toString();
   }
@@ -60,6 +57,6 @@ export class CidrMask {
   }
 
   toString() {
-    return `${new IpAddress(this.address)}/${this.netmask}`;
+    return `${new IpAddress(this.address)}/${this.prefix}`;
   }
 }
diff --git a/src/plugins/data/common/search/aggs/utils/ip_address.test.ts b/src/plugins/data/common/search/aggs/utils/ip_address.test.ts
index 966408cf6fe2..0d51714f114b 100644
--- a/src/plugins/data/common/search/aggs/utils/ip_address.test.ts
+++ b/src/plugins/data/common/search/aggs/utils/ip_address.test.ts
@@ -37,21 +37,6 @@ describe('IpAddress', () => {
     });
   });
 
-  describe('valueOf', () => {
-    it.each`
-      address            | expected
-      ${'0.0.0.0'}       | ${'0'}
-      ${'0.0.0.1'}       | ${'1'}
-      ${'126.45.211.34'} | ${'2116932386'}
-      ${'ffff::'}        | ${'340277174624079928635746076935438991360'}
-    `(
-      'should return $expected as a decimal representation of $address',
-      ({ address, expected }) => {
-        expect(new IpAddress(address).valueOf().toString()).toBe(expected);
-      }
-    );
-  });
-
   describe('toString()', () => {
     it.each`
       address                 | expected
diff --git a/src/plugins/data/common/search/aggs/utils/ip_address.ts b/src/plugins/data/common/search/aggs/utils/ip_address.ts
index 2fffbc468046..ba7972588c54 100644
--- a/src/plugins/data/common/search/aggs/utils/ip_address.ts
+++ b/src/plugins/data/common/search/aggs/utils/ip_address.ts
@@ -32,16 +32,4 @@ export class IpAddress {
 
     return this.value.toString();
   }
-
-  valueOf(): number | bigint {
-    const value = this.value
-      .toByteArray()
-      .reduce((result, octet) => result * 256n + BigInt(octet), 0n);
-
-    if (value > Number.MAX_SAFE_INTEGER) {
-      return value;
-    }
-
-    return Number(value);
-  }
 }