Merge pull request #131 from libp2p/fix/no-dns

fix: avoid dialing/listening on dns addresses

p2p/transport/quic/transport.go

@@ -190,9 +190,12 @@ func (t *transport) Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (tp
 	}, nil
 }
 
+// Don't use mafmt.QUIC as we don't want to dial DNS addresses. Just /ip{4,6}/udp/quic
+var dialMatcher = mafmt.And(mafmt.IP, mafmt.Base(ma.P_UDP), mafmt.Base(ma.P_QUIC))
+
 // CanDial determines if we can dial to an address
 func (t *transport) CanDial(addr ma.Multiaddr) bool {
-	return mafmt.QUIC.Matches(addr)
+	return dialMatcher.Matches(addr)
 }
 
 // Listen listens for new QUIC connections on the passed multiaddr.

p2p/transport/quic/transport_test.go

@@ -24,6 +24,12 @@ var _ = Describe("Transport", func() {
 		Expect(t.CanDial(validAddr)).To(BeTrue())
 	})
 
+	It("says that it cannot dial /dns addresses", func() {
+		addr, err := ma.NewMultiaddr("/dns/google.com/udp/443/quic")
+		Expect(err).ToNot(HaveOccurred())
+		Expect(t.CanDial(addr)).To(BeFalse())
+	})
+
 	It("supports the QUIC protocol", func() {
 		protocols := t.Protocols()
 		Expect(protocols).To(HaveLen(1))