common/ip.go

package common

import "net"

func IsPrivateIP(ip net.IP) bool {
	if ip.IsLoopback() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
		return true
	}

	private := []net.IPNet{
		{IP: net.IPv4(10, 0, 0, 0), Mask: net.CIDRMask(8, 32)},
		{IP: net.IPv4(172, 16, 0, 0), Mask: net.CIDRMask(12, 32)},
		{IP: net.IPv4(192, 168, 0, 0), Mask: net.CIDRMask(16, 32)},
	}

	for _, privateNet := range private {
		if privateNet.Contains(ip) {
			return true
		}
	}
	return false
}