matchIPv4Subnet

main_test.go

package main

import (
	"testing"
)

func matchIPv4Subnet(addr, cidrAddr, prefix uint32) bool {
	var mask uint32
	if prefix >= 32 {
		mask = 0xffffffff
	} else {
		mask = ^(0xffffffff >> prefix)
	}
	return (addr & mask) == (cidrAddr & mask)
}

func BenchmarkIPSubnetComparison(b *testing.B) {
	subnets := []struct {
		cidrAddr uint32
		prefix   uint32
	}{
		{0x5B6B3800, 22}, // 91.108.56.0/22
		{0x5B6B0400, 22}, // 91.108.4.0/22
		{0x5B6B0800, 22}, // 91.108.8.0/22
		{0x5B6B1000, 22}, // 91.108.16.0/22
		{0x5B6B0C00, 22}, // 91.108.12.0/22
		{0x959AA000, 20}, // 149.154.160.0/20
		{0x5B69C000, 23}, // 91.105.192.0/23
		{0x5B6B1400, 22}, // 91.108.20.0/22
		{0xB94C9700, 24}, // 185.76.151.0/24
	}

	addr := uint32(0x5B6B3B64)

	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		for _, subnet := range subnets {
			matchIPv4Subnet(addr, subnet.cidrAddr, subnet.prefix)
		}
	}
}

func main() {
	testing.Benchmark(BenchmarkIPSubnetComparison)
}