From dff7fed63c6344ecec0f8b7bbffa84b9db628bbe Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Tue, 21 Dec 2021 12:29:45 +0400
Subject: [PATCH] remove wrong (and redundant) IsIpv6LinkLocal

---
 net/ip.go           | 12 ------------
 net/net_test.go     | 19 ++++++++++++++++++-
 net/resolve.go      |  2 +-
 net/resolve_test.go | 18 ------------------
 4 files changed, 19 insertions(+), 32 deletions(-)

diff --git a/net/ip.go b/net/ip.go
index fab5ee5..1cf9a77 100644
--- a/net/ip.go
+++ b/net/ip.go
@@ -95,18 +95,6 @@ func IsIPUnspecified(m ma.Multiaddr) bool {
 	return net.IP(c.RawValue()).IsUnspecified()
 }
 
-// IsIpv6LinkLocal returns whether the addr uses a non-local ip link
-func IsIpv6LinkLocal(a ma.Multiaddr) bool {
-	split := ma.Split(a)
-	if len(split) < 1 {
-		return false
-	}
-	if IsIP6LinkLocal(split[0]) {
-		return false
-	}
-	return true
-}
-
 // If m matches [zone,ip6,...], return [ip6,...]
 // else if m matches [], [zone], or [zone,...], return nil
 // else return m
diff --git a/net/net_test.go b/net/net_test.go
index 6483a9b..a2c13e2 100644
--- a/net/net_test.go
+++ b/net/net_test.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	ma "github.com/multiformats/go-multiaddr"
+	"github.com/stretchr/testify/require"
 )
 
 func newMultiaddr(t *testing.T, m string) ma.Multiaddr {
@@ -449,7 +450,7 @@ func TestIPUnspecified(t *testing.T) {
 
 func TestIP6LinkLocal(t *testing.T) {
 	for a := 0; a < 65536; a++ {
-		isLinkLocal := (a&0xffc0 == 0xfe80 || a&0xff0f == 0xff02)
+		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)
@@ -459,6 +460,22 @@ func TestIP6LinkLocal(t *testing.T) {
 	if !IsIP6LinkLocal(newMultiaddr(t, "/ip6zone/hello/ip6/fe80::9999")) {
 		t.Error("IsIP6LinkLocal failed (/ip6/fe80::9999)")
 	}
+
+	bad := []ma.Multiaddr{
+		newMultiaddr(t, "/ip6/fe80::1/tcp/1234"),   // link local
+		newMultiaddr(t, "/ip6/fe80::100/tcp/1234"), // link local
+	}
+	good := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234"),
+		newMultiaddr(t, "/ip6/::1/tcp/1234"),
+		newMultiaddr(t, "/ip4/1.2.3.4/udp/1234/utp"),
+	}
+	for _, addr := range bad {
+		require.True(t, IsIP6LinkLocal(addr), "%s is a link local addr", addr)
+	}
+	for _, addr := range good {
+		require.False(t, IsIP6LinkLocal(addr), "%s is not a link local addr", addr)
+	}
 }
 
 func TestConvertNetAddr(t *testing.T) {
diff --git a/net/resolve.go b/net/resolve.go
index d9d0a4d..a2478e7 100644
--- a/net/resolve.go
+++ b/net/resolve.go
@@ -74,7 +74,7 @@ func interfaceAddresses() ([]ma.Multiaddr, error) {
 
 	var out []ma.Multiaddr
 	for _, a := range maddrs {
-		if !IsIpv6LinkLocal(a) {
+		if IsIP6LinkLocal(a) {
 			continue
 		}
 		out = append(out, a)
diff --git a/net/resolve_test.go b/net/resolve_test.go
index f2472f8..387e70a 100644
--- a/net/resolve_test.go
+++ b/net/resolve_test.go
@@ -55,21 +55,3 @@ func TestResolvingAddrs(t *testing.T) {
 		t.Fatal("should have failed")
 	}
 }
-
-func TestAddrOverNonLocalIP(t *testing.T) {
-	bad := []ma.Multiaddr{
-		newMultiaddr(t, "/ip6/fe80::1/tcp/1234"),   // link local
-		newMultiaddr(t, "/ip6/fe80::100/tcp/1234"), // link local
-	}
-	good := []ma.Multiaddr{
-		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234"),
-		newMultiaddr(t, "/ip6/::1/tcp/1234"),
-		newMultiaddr(t, "/ip4/1.2.3.4/udp/1234/utp"),
-	}
-	for _, addr := range bad {
-		require.Falsef(t, IsIpv6LinkLocal(addr), "%s is a link local addr", addr)
-	}
-	for _, addr := range good {
-		require.Truef(t, IsIpv6LinkLocal(addr), "%s is not a link local addr", addr)
-	}
-}