package lncfg import ( "crypto/tls" "fmt" "net" "strconv" "strings" "time" "github.com/lightningnetwork/lnd/tor" ) var ( loopBackAddrs = []string{"localhost", "127.0.0.1", "[::1]"} ) type tcpResolver = func(network, addr string) (*net.TCPAddr, error) // NormalizeAddresses returns a new slice with all the passed addresses // normalized with the given default port and all duplicates removed. func NormalizeAddresses(addrs []string, defaultPort string, tcpResolver tcpResolver) ([]net.Addr, error) { result := make([]net.Addr, 0, len(addrs)) seen := map[string]struct{}{} for _, addr := range addrs { parsedAddr, err := ParseAddressString( addr, defaultPort, tcpResolver, ) if err != nil { return nil, err } if _, ok := seen[parsedAddr.String()]; !ok { result = append(result, parsedAddr) seen[parsedAddr.String()] = struct{}{} } } return result, nil } // EnforceSafeAuthentication enforces "safe" authentication taking into account // the interfaces that the RPC servers are listening on, and if macaroons are // activated or not. To protect users from using dangerous config combinations, // we'll prevent disabling authentication if the sever is listening on a public // interface. func EnforceSafeAuthentication(addrs []net.Addr, macaroonsActive bool) error { // We'll now examine all addresses that this RPC server is listening // on. If it's a localhost address, we'll skip it, otherwise, we'll // return an error if macaroons are inactive. for _, addr := range addrs { if IsLoopback(addr.String()) || IsUnix(addr) { continue } if !macaroonsActive { return fmt.Errorf("Detected RPC server listening on "+ "publicly reachable interface %v with "+ "authentication disabled! Refusing to start "+ "with --no-macaroons specified.", addr) } } return nil } // ListenOnAddress creates a listener that listens on the given address. func ListenOnAddress(addr net.Addr) (net.Listener, error) { return net.Listen(addr.Network(), addr.String()) } // TLSListenOnAddress creates a TLS listener that listens on the given address. func TLSListenOnAddress(addr net.Addr, config *tls.Config) (net.Listener, error) { return tls.Listen(addr.Network(), addr.String(), config) } // IsLoopback returns true if an address describes a loopback interface. func IsLoopback(addr string) bool { for _, loopback := range loopBackAddrs { if strings.Contains(addr, loopback) { return true } } return false } // IsUnix returns true if an address describes an Unix socket address. func IsUnix(addr net.Addr) bool { return strings.HasPrefix(addr.Network(), "unix") } // ParseAddressString converts an address in string format to a net.Addr that is // compatible with lnd. UDP is not supported because lnd needs reliable // connections. We accept a custom function to resolve any TCP addresses so // that caller is able control exactly how resolution is performed. func ParseAddressString(strAddress string, defaultPort string, tcpResolver tcpResolver) (net.Addr, error) { var parsedNetwork, parsedAddr string // Addresses can either be in network://address:port format, // network:address:port, address:port, or just port. We want to support // all possible types. if strings.Contains(strAddress, "://") { parts := strings.Split(strAddress, "://") parsedNetwork, parsedAddr = parts[0], parts[1] } else if strings.Contains(strAddress, ":") { parts := strings.Split(strAddress, ":") parsedNetwork = parts[0] parsedAddr = strings.Join(parts[1:], ":") } // Only TCP and Unix socket addresses are valid. We can't use IP or // UDP only connections for anything we do in lnd. switch parsedNetwork { case "unix", "unixpacket": return net.ResolveUnixAddr(parsedNetwork, parsedAddr) case "tcp", "tcp4", "tcp6": return tcpResolver( parsedNetwork, verifyPort(parsedAddr, defaultPort), ) case "ip", "ip4", "ip6", "udp", "udp4", "udp6", "unixgram": return nil, fmt.Errorf("only TCP or unix socket "+ "addresses are supported: %s", parsedAddr) default: // We'll now possibly apply the default port, use the local // host short circuit, or parse out an all interfaces listen. addrWithPort := verifyPort(strAddress, defaultPort) rawHost, rawPort, _ := net.SplitHostPort(addrWithPort) // If we reach this point, then we'll check to see if we have // an onion addresses, if so, we can directly pass the raw // address and port to create the proper address. if tor.IsOnionHost(rawHost) { portNum, err := strconv.Atoi(rawPort) if err != nil { return nil, err } return &tor.OnionAddr{ OnionService: rawHost, Port: portNum, }, nil } // Otherwise, we'll attempt the resolve the host. The Tor // resolver is unable to resolve local addresses, so we'll use // the system resolver instead. if rawHost == "" || IsLoopback(rawHost) { return net.ResolveTCPAddr("tcp", addrWithPort) } return tcpResolver("tcp", addrWithPort) } } // verifyPort makes sure that an address string has both a host and a port. If // there is no port found, the default port is appended. If the address is just // a port, then we'll assume that the user is using the short cut to specify a // localhost:port address. func verifyPort(address string, defaultPort string) string { host, port, err := net.SplitHostPort(address) if err != nil { // If the address itself is just an integer, then we'll assume // that we're mapping this directly to a localhost:port pair. // This ensures we maintain the legacy behavior. if _, err := strconv.Atoi(address); err == nil { return net.JoinHostPort("localhost", address) } // Otherwise, we'll assume that the address just failed to // attach its own port, so we'll use the default port. In the // case of IPv6 addresses, if the host is already surrounded by // brackets, then we'll avoid using the JoinHostPort function, // since it will always add a pair of brackets. if strings.HasPrefix(address, "[") { return address + ":" + defaultPort } return net.JoinHostPort(address, defaultPort) } // In the case that both the host and port are empty, we'll use the // default port. if host == "" && port == "" { return ":" + defaultPort } return address } // ClientAddressDialer creates a gRPC dialer that can also dial unix socket // addresses instead of just TCP addresses. func ClientAddressDialer(defaultPort string) func(string, time.Duration) (net.Conn, error) { return func(addr string, timeout time.Duration) (net.Conn, error) { parsedAddr, err := ParseAddressString( addr, defaultPort, net.ResolveTCPAddr, ) if err != nil { return nil, err } return net.DialTimeout( parsedAddr.Network(), parsedAddr.String(), timeout, ) } }