// 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
}
// 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
}
// MultiaddrProtocolsMatch returns whether two multiaddrs match in protocol stacks.
func MultiaddrProtocolsMatch(a, b ma.Multiaddr) bool {
ap := a.Protocols()
bp := b.Protocols()
if len(ap) != len(bp) {
return false
}
for i, api := range ap {
if api.Code != bp[i].Code {
return false
}
}
return true
}
// AddrUsable returns whether our network can use this addr.
// We only use the transports in SupportedTransportStrings,
// and we do not link local addresses. Loopback is ok
// as we need to be able to connect to multiple ipfs nodes
// in the same machine.
func AddrUsable(a ma.Multiaddr, partial bool) bool {
if a == nil {
return false
}
if !AddrOverNonLocalIP(a) {
return false
}
// test the address protocol list is in SupportedTransportProtocols
matches := func(supported, test []ma.Protocol) bool {
if len(test) > len(supported) {
return false
}
// when partial, it's ok if test < supported.
if !partial && len(supported) != len(test) {
return false
}
for i := range test {
if supported[i].Code != test[i].Code {
return false
}
}
return true
}
transport := a.Protocols()
for _, supported := range SupportedTransportProtocols {
if matches(supported, transport) {
return true
}
}
return false
}
// 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
}
}
func isTCPMultiaddr(a ma.Multiaddr) bool {
p := a.Protocols()
return len(p) == 2 && (p[0].Name == "ip4" || p[0].Name == "ip6") && p[1].Name == "tcp"
}
func IsUtpMultiaddr(a ma.Multiaddr) bool {
p := a.Protocols()
return len(p) == 3 && p[2].Name == "utp"
}