diff --git a/ip.go b/ip.go index e5054dc..ef39c71 100644 --- a/ip.go +++ b/ip.go @@ -1,7 +1,7 @@ package manet import ( - "bytes" + "net" ma "github.com/multiformats/go-multiaddr" ) @@ -24,14 +24,6 @@ var ( 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.* - {ma.P_IP6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 127}, // ::ffff:127.* - IP6Loopback.Bytes(), // ::1 -} - // IsThinWaist returns whether a Multiaddr starts with "Thin Waist" Protocols. // This means: /{IP4, IP6}[/{TCP, UDP}] func IsThinWaist(m ma.Multiaddr) bool { @@ -62,22 +54,41 @@ func IsThinWaist(m ma.Multiaddr) bool { // IsIPLoopback returns whether a Multiaddr is a "Loopback" IP address // This means either /ip4/127.*.*.*, /ip6/::1, or /ip6/::ffff:127.*.*.*.* func IsIPLoopback(m ma.Multiaddr) bool { - b := m.Bytes() - for _, prefix := range loopbackPrefixes { - if bytes.HasPrefix(b, prefix) { - return true - } + c, rest := ma.SplitFirst(m) + if rest != nil { + // Not *just* an IPv4 addr + return false + } + switch c.Protocol().Code { + case ma.P_IP4, ma.P_IP6: + return net.IP(c.RawValue()).IsLoopback() } 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. +// IsIP6LinkLocal returns if a an IPv6 link-local multiaddress (with zero or +// more leading zones). These addresses are non routable. func IsIP6LinkLocal(m ma.Multiaddr) bool { - return bytes.HasPrefix(m.Bytes(), []byte{ma.P_IP6, 0xfe, 0x80}) + matched := false + ma.ForEach(m, func(c ma.Component) bool { + // Too much. + if matched { + matched = false + return false + } + + switch c.Protocol().Code { + case ma.P_IP6ZONE: + return true + case ma.P_IP6: + ip := net.IP(c.RawValue()) + matched = ip.IsLinkLocalMulticast() || ip.IsLinkLocalUnicast() + return true + default: + return false + } + }) + return matched } // IsIPUnspecified returns whether a Multiaddr is am Unspecified IP address diff --git a/net_test.go b/net_test.go index 1e88462..cccdabc 100644 --- a/net_test.go +++ b/net_test.go @@ -322,6 +322,10 @@ func TestIPLoopback(t *testing.T) { t.Error("IsIPLoopback false positive (/ip4/112.123.11.1)") } + if IsIPLoopback(newMultiaddr(t, "/ip4/127.0.0.1/ip4/127.0.0.1")) { + t.Error("IsIPLoopback false positive (/ip4/127.0.0.1/127.0.0.1)") + } + if IsIPLoopback(newMultiaddr(t, "/ip4/192.168.0.1/ip6/::1")) { t.Error("IsIPLoopback false positive (/ip4/192.168.0.1/ip6/::1)") } @@ -363,7 +367,7 @@ func TestIPUnspecified(t *testing.T) { func TestIP6LinkLocal(t *testing.T) { for a := 0; a < 65536; a++ { - isLinkLocal := (a == 0xfe80) + isLinkLocal := (a&0xffc0 == 0xfe80 || a&0xff0f == 0xff02) m := newMultiaddr(t, fmt.Sprintf("/ip6/%x::1", a)) if IsIP6LinkLocal(m) != isLinkLocal { t.Errorf("IsIP6LinkLocal failed (%s != %v)", m, isLinkLocal)