// ResolveUnspecifiedAddress expands an unspecified ip addresses (/ip4/0.0.0.0, /ip6/::) to
// use the known local interfaces. If ifaceAddr is nil, we request interface addresses
// from the network stack. (this is so you can provide a cached value if resolving many addrs)
func ResolveUnspecifiedAddress(resolve ma.Multiaddr, ifaceAddrs []ma.Multiaddr) ([]ma.Multiaddr, error) {
// split address into its components
split := ma.Split(resolve)
// if first component (ip) is not unspecified, use it as is.
if !manet.IsIPUnspecified(split[0]) {
return []ma.Multiaddr{resolve}, nil
}
out := make([]ma.Multiaddr, 0, len(ifaceAddrs))
for _, ia := range ifaceAddrs {
// must match the first protocol to be resolve.
if ia.Protocols()[0].Code != resolve.Protocols()[0].Code {
continue
}
split[0] = ia
joined := ma.Join(split...)
out = append(out, joined)
log.Debug("adding resolved addr:", resolve, joined, out)
}
if len(out) < 1 {
return nil, fmt.Errorf("failed to resolve: %s", resolve)
}
return out, nil
}
// AddrIsShareableOnWAN returns whether the given address should be shareable on the
// wide area network (wide internet).
func AddrIsShareableOnWAN(addr ma.Multiaddr) bool {
s := ma.Split(addr)
if len(s) < 1 {
return false
}
a := s[0]
if manet.IsIPLoopback(a) || manet.IsIP6LinkLocal(a) || manet.IsIPUnspecified(a) {
return false
}
return manet.IsThinWaist(a)
}