status-go/vendor/github.com/multiformats/go-multiaddr-net/ip.go

88 lines
2.2 KiB
Go

package manet
import (
"bytes"
ma "github.com/multiformats/go-multiaddr"
)
// Loopback Addresses
var (
// IP4Loopback is the ip4 loopback multiaddr
IP4Loopback = ma.StringCast("/ip4/127.0.0.1")
// IP6Loopback is the ip6 loopback multiaddr
IP6Loopback = ma.StringCast("/ip6/::1")
// IP6LinkLocalLoopback is the ip6 link-local loopback multiaddr
IP6LinkLocalLoopback = ma.StringCast("/ip6/fe80::1")
)
// Unspecified Addresses (used for )
var (
IP4Unspecified = ma.StringCast("/ip4/0.0.0.0")
IP6Unspecified = ma.StringCast("/ip6/::")
)
// Loopback multiaddr prefixes. Any multiaddr beginning with one of the
// following byte sequences is considered a loopback multiaddr.
var loopbackPrefixes = [][]byte{
{ma.P_IP4, 127}, // 127.*
IP6LinkLocalLoopback.Bytes(),
IP6Loopback.Bytes(),
}
// 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
}
}
// IsIPLoopback returns whether a Multiaddr is a "Loopback" IP address
// This means either /ip4/127.*.*.*, /ip6/::1, or /ip6/fe80::1
func IsIPLoopback(m ma.Multiaddr) bool {
b := m.Bytes()
for _, prefix := range loopbackPrefixes {
if bytes.HasPrefix(b, prefix) {
return true
}
}
return false
}
// IsIP6LinkLocal returns if a multiaddress is an IPv6 local link. These
// 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})
}
// IsIPUnspecified returns whether a Multiaddr is am Unspecified IP address
// This means either /ip4/0.0.0.0 or /ip6/::
func IsIPUnspecified(m ma.Multiaddr) bool {
return IP4Unspecified.Equal(m) || IP6Unspecified.Equal(m)
}