ginbump/request_address.go
func IsPublicIP(ip net.IP) bool {
	if !ip.IsGlobalUnicast() {
		return false
	}

	for _, mask := range privateMasks {
		if mask.Contains(ip) {
			return false
		}
	}

	return true
}
func IsPublicIP(ip net.IP) bool {
	if !ip.IsGlobalUnicast() {
		return false
	}

	for _, mask := range privateMasks {
		if mask.Contains(ip) {
			return false
		}
	}

	return true
}
// IsPublicIP returns true if the given IP can be routed on the Internet