// AddrMatch returns the Multiaddrs that match the protocol stack on addr
func AddrMatch(match ma.Multiaddr, addrs []ma.Multiaddr) []ma.Multiaddr {
// we should match transports entirely.
p1s := match.Protocols()
out := make([]ma.Multiaddr, 0, len(addrs))
for _, a := range addrs {
p2s := a.Protocols()
if len(p1s) != len(p2s) {
continue
}
match := true
for i, p2 := range p2s {
if p1s[i].Code != p2.Code {
match = false
break
}
}
if match {
out = append(out, a)
}
}
return out
}
// DialArgs is a convenience function returning arguments for use in net.Dial
func DialArgs(m ma.Multiaddr) (string, string, error) {
if !IsThinWaist(m) {
return "", "", fmt.Errorf("%s is not a 'thin waist' address", m)
}
str := m.String()
parts := strings.Split(str, "/")[1:]
if len(parts) == 2 { // only IP
return parts[0], parts[1], nil
}
network := parts[2]
if parts[2] == "udp" && len(parts) > 4 && parts[4] == "utp" {
network = parts[4]
}
var host string
switch parts[0] {
case "ip4":
network = network + "4"
host = strings.Join([]string{parts[1], parts[3]}, ":")
case "ip6":
network = network + "6"
host = fmt.Sprintf("[%s]:%s", parts[1], parts[3])
}
return network, host, nil
}
// IsIPLoopback returns whether a Multiaddr is a "Loopback" IP address
// This means either /ip4/127.0.0.1 or /ip6/::1
// TODO: differentiate IsIPLoopback and OverIPLoopback
func IsIPLoopback(m ma.Multiaddr) bool {
b := m.Bytes()
// /ip4/127 prefix (_entire_ /8 is loopback...)
if bytes.HasPrefix(b, []byte{ma.P_IP4, 127}) {
return true
}
// /ip6/::1
if IP6Loopback.Equal(m) || IP6LinkLocalLoopback.Equal(m) {
return true
}
return false
}
func outfmt(m ma.Multiaddr) string {
switch format {
case "string":
return m.String()
case "slice":
return fmt.Sprintf("%v", m.Bytes())
case "bytes":
return string(m.Bytes())
case "hex":
return "0x" + hex.EncodeToString(m.Bytes())
}
die("error: invalid format", format)
return ""
}
// IsThinWaist returns whether a Multiaddr starts with "Thin Waist" Protocols.
// This means: /{IP4, IP6}[/{TCP, UDP}]
func IsThinWaist(m ma.Multiaddr) bool {
p := m.Protocols()
// nothing? not even a waist.
if len(p) == 0 {
return false
}
if p[0].Code != ma.P_IP4 && p[0].Code != ma.P_IP6 {
return false
}
// only IP? still counts.
if len(p) == 1 {
return true
}
switch p[1].Code {
case ma.P_TCP, ma.P_UDP, ma.P_IP4, ma.P_IP6:
return true
default:
return false
}
}
// IP6 Link Local addresses are non routable. The prefix is technically
// fe80::/10, but we test fe80::/16 for simplicity (no need to mask).
// So far, no hardware interfaces exist long enough to use those 2 bits.
// Send a PR if there is.
func IsIP6LinkLocal(m ma.Multiaddr) bool {
return bytes.HasPrefix(m.Bytes(), []byte{ma.P_IP6, 0xfe, 0x80})
}