lnd.xprv/lncfg/address.go

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package lncfg
import (
"time"
"net"
"fmt"
"crypto/tls"
"strings"
)
var (
loopBackAddrs = []string{"localhost", "127.0.0.1", "[::1]"}
)
// 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) ([]net.Addr, error) {
result := make([]net.Addr, 0, len(addrs))
seen := map[string]struct{}{}
for _, strAddr := range addrs {
addr, err := ParseAddressString(strAddr, defaultPort)
if err != nil {
return nil, err
}
if _, ok := seen[addr.String()]; !ok {
result = append(result, addr)
seen[addr.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) || 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 net.Addr) bool {
for _, loopback := range loopBackAddrs {
if strings.Contains(addr.String(), 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.
func ParseAddressString(strAddress string,
defaultPort string) (net.Addr, error) {
var parsedNetwork, parsedAddr string
// Addresses can either be in network://address:port format or only
// address:port. We want to support both.
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 net.ResolveTCPAddr(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:
// There was no network specified, just try to parse as host
// and port.
return net.ResolveTCPAddr(
"tcp", verifyPort(strAddress, defaultPort),
)
}
}
// 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.
func verifyPort(strAddress string, defaultPort string) string {
host, port, err := net.SplitHostPort(strAddress)
if err != nil {
// If we already have an IPv6 address with brackets, don't use
// the JoinHostPort function, since it will always add a pair
// of brackets too.
if strings.HasPrefix(strAddress, "[") {
strAddress = strAddress + ":" + defaultPort
} else {
strAddress = net.JoinHostPort(strAddress, defaultPort)
}
} else if host == "" && port == "" {
// The string ':' is parsed as valid empty host and empty port.
// But in that case, we want the default port to be applied too.
strAddress = ":" + defaultPort
}
return strAddress
}
// 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)
if err != nil {
return nil, err
}
return net.DialTimeout(parsedAddr.Network(),
parsedAddr.String(), timeout)
}
}