Fix ip picking from subnet in exclusion

This commit is contained in:
Owen 2025-03-27 22:13:39 -04:00
parent fbe7e0a427
commit 4b6985718a
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GPG key ID: 8271FDFFD9E0CCBD
2 changed files with 33 additions and 14 deletions

View file

@ -4,7 +4,14 @@ import { assertEquals } from "@test/assert";
// Test cases
function testFindNextAvailableCidr() {
console.log("Running findNextAvailableCidr tests...");
// Test 0: Basic IPv4 allocation with a subnet in the wrong range
{
const existing = ["100.90.130.1/30", "100.90.128.4/30"];
const result = findNextAvailableCidr(existing, 30, "100.90.130.1/24");
assertEquals(result, "100.90.130.4/30", "Basic IPv4 allocation failed");
}
// Test 1: Basic IPv4 allocation
{
const existing = ["10.0.0.0/16", "10.1.0.0/16"];
@ -26,6 +33,12 @@ function testFindNextAvailableCidr() {
assertEquals(result, null, "No available space test failed");
}
// Test 4: Empty existing
{
const existing: string[] = [];
const result = findNextAvailableCidr(existing, 30, "10.0.0.0/8");
assertEquals(result, "10.0.0.0/30", "Empty existing test failed");
}
// // Test 4: IPv6 allocation
// {
// const existing = ["2001:db8::/32", "2001:db8:1::/32"];

View file

@ -132,7 +132,6 @@ export function findNextAvailableCidr(
blockSize: number,
startCidr?: string
): string | null {
if (!startCidr && existingCidrs.length === 0) {
return null;
}
@ -150,40 +149,47 @@ export function findNextAvailableCidr(
existingCidrs.some(cidr => detectIpVersion(cidr.split('/')[0]) !== version)) {
throw new Error('All CIDRs must be of the same IP version');
}
// Extract the network part from startCidr to ensure we stay in the right subnet
const startCidrRange = cidrToRange(startCidr);
// Convert existing CIDRs to ranges and sort them
const existingRanges = existingCidrs
.map(cidr => cidrToRange(cidr))
.sort((a, b) => (a.start < b.start ? -1 : 1));
// Calculate block size
const maxPrefix = version === 4 ? 32 : 128;
const blockSizeBigInt = BigInt(1) << BigInt(maxPrefix - blockSize);
// Start from the beginning of the given CIDR
let current = cidrToRange(startCidr).start;
const maxIp = cidrToRange(startCidr).end;
let current = startCidrRange.start;
const maxIp = startCidrRange.end;
// Iterate through existing ranges
for (let i = 0; i <= existingRanges.length; i++) {
const nextRange = existingRanges[i];
// Align current to block size
const alignedCurrent = current + ((blockSizeBigInt - (current % blockSizeBigInt)) % blockSizeBigInt);
// Check if we've gone beyond the maximum allowed IP
if (alignedCurrent + blockSizeBigInt - BigInt(1) > maxIp) {
return null;
}
// If we're at the end of existing ranges or found a gap
if (!nextRange || alignedCurrent + blockSizeBigInt - BigInt(1) < nextRange.start) {
return `${bigIntToIp(alignedCurrent, version)}/${blockSize}`;
}
// Move current pointer to after the current range
current = nextRange.end + BigInt(1);
// If next range overlaps with our search space, move past it
if (nextRange.end >= startCidrRange.start && nextRange.start <= maxIp) {
// Move current pointer to after the current range
current = nextRange.end + BigInt(1);
}
}
return null;
}