Fail DNS resolution if the result contains 127.0.53.53.

net/dns/host_resolver_impl_unittest.cc

Index: net/dns/host_resolver_impl_unittest.cc
diff --git a/net/dns/host_resolver_impl_unittest.cc b/net/dns/host_resolver_impl_unittest.cc
index 7a46a1c4dc4e3cfc1998858a5fb8bc75bd9b0fe7..770a57a21e2279185fee64f05900d6b4464d3ffb 100644
--- a/net/dns/host_resolver_impl_unittest.cc
+++ b/net/dns/host_resolver_impl_unittest.cc
@@ -1319,6 +1319,36 @@ TEST_F(HostResolverImplTest, MultipleAttempts) {
   EXPECT_EQ(resolver_proc->resolved_attempt_number(), kAttemptNumberToResolve);
 }
 
+// If a host resolves to a list that includes 127.0.53.53, this is treated as
+// an error. 127.0.53.53 is a localhost address, however it has been given a
+// special significance by ICANN to help surfance name collision resulting from
+// the new gTLDs.
+TEST_F(HostResolverImplTest, NameCollision127_0_53_53) {
+  proc_->AddRuleForAllFamilies("single", "127.0.53.53");
+  proc_->AddRuleForAllFamilies("multiple", "127.0.0.1,127.0.53.53");
+  proc_->AddRuleForAllFamilies("ipv6", "::127.0.53.53");
+  proc_->SignalMultiple(3u);
+
+  Request* request;
+
+  request = CreateRequest("single");
+  EXPECT_EQ(ERR_IO_PENDING, request->Resolve());
+  EXPECT_EQ(ERR_FAILED, request->WaitForResult());

[Ryan Sleevi, 2015/03/26 00:32:29]

We don't give a better error here? To ensure that it gets the ICANN flag?

[eroman, 2015/03/26 00:39:31]

d'oh, forgot to update the unittest after adding the error code.
Fixed.

+
+  request = CreateRequest("multiple");
+  EXPECT_EQ(ERR_IO_PENDING, request->Resolve());
+  EXPECT_EQ(ERR_FAILED, request->WaitForResult());
+
+  // Resolving an IP literal of 127.0.53.53 however is allowed.
+  EXPECT_EQ(OK, CreateRequest("127.0.53.53")->Resolve());
+
+  // Moreover the address should not be recognized when embedded in an IPv6
+  // address.
+  request = CreateRequest("ipv6");
+  EXPECT_EQ(ERR_IO_PENDING, request->Resolve());
+  EXPECT_EQ(OK, request->WaitForResult());
+}
+
 DnsConfig CreateValidDnsConfig() {
   IPAddressNumber dns_ip;
   bool rv = ParseIPLiteralToNumber("192.168.1.0", &dns_ip);