[net/dns] Terminate suffix search at NOERROR response even if it includes no addresses.

BUG=115054
TEST=./net_unittests --gtest_filter=DnsTransactionTest.SuffixSearchStop



Review URL: http://codereview.chromium.org/9787001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@127870 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 46 insertions, 12 deletions

diff --git a/net/dns/dns_response.cc b/net/dns/dns_response.cc
index 9518095..725629b 100644
--- a/net/dns/dns_response.cc
+++ b/net/dns/dns_response.cc
@@ -279,6 +279,7 @@ DnsResponse::Result DnsResponse::ParseToAddressList(
     }
   }
 
+  // TODO(szym): Extract TTL for NODATA results. http://crbug.com/115051
   if (ip_addresses.empty())
     return DNS_NO_ADDRESSES;
 
diff --git a/net/dns/dns_response_unittest.cc b/net/dns/dns_response_unittest.cc
index 6cbf6a1..1861f10 100644
--- a/net/dns/dns_response_unittest.cc
+++ b/net/dns/dns_response_unittest.cc
@@ -358,7 +358,7 @@ const uint8 kResponseNameMismatchInChain[] = {
   0x00, 0x00, 0x81, 0x80, 0x00, 0x01, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00,
   // Question: name = 'a', type = A (0x1)
   0x01,  'a', 0x00, 0x00, 0x01, 0x00, 0x01,
-  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = "b"
+  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = 'b'
   0x01,  'a', 0x00, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0xFF,
   0x00, 0x03, 0x01,  'b', 0x00,
   // Answer: name = 'b', type = A, TTL = 0xFF, RDATA = 10.10.10.10
@@ -387,7 +387,7 @@ const uint8 kResponseCNAMEAfterAddress[] = {
   // Answer: name = 'a', type = A, TTL = 0xFF, RDATA = 10.10.10.10.
   0x01,  'a', 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0xFF,
   0x00, 0x04, 0x0A, 0x0A, 0x0A, 0x0A,
-  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = "b"
+  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = 'b'
   0x01,  'a', 0x00, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0xFF,
   0x00, 0x03, 0x01,  'b', 0x00,
 };
@@ -397,7 +397,7 @@ const uint8 kResponseTTLMismatch[] = {
   0x00, 0x00, 0x81, 0x80, 0x00, 0x01, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00,
   // Question: name = 'a', type = A (0x1)
   0x01,  'a', 0x00, 0x00, 0x01, 0x00, 0x01,
-  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = "b"
+  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = 'b'
   0x01,  'a', 0x00, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0xFF,
   0x00, 0x03, 0x01,  'b', 0x00,
   // Answer: name = 'b', type = A, TTL = 0xFF, RDATA = 10.10.10.10
@@ -410,10 +410,10 @@ const uint8 kResponseTTLMismatch[] = {
 
 const uint8 kResponseNoAddresses[] = {
   // Header: 1 question, 1 answer RR, 1 authority RR
-  0x00, 0x00, 0x81, 0x80, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
+  0x00, 0x00, 0x81, 0x80, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
   // Question: name = 'a', type = A (0x1)
   0x01,  'a', 0x00, 0x00, 0x01, 0x00, 0x01,
-  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = "b"
+  // Answer: name = 'a', type = CNAME, TTL = 0xFF, RDATA = 'b'
   0x01,  'a', 0x00, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0xFF,
   0x00, 0x03, 0x01, 'b', 0x00,
   // Authority section
diff --git a/net/dns/dns_transaction.cc b/net/dns/dns_transaction.cc
index 8a0753f..77d1e59 100644
--- a/net/dns/dns_transaction.cc
+++ b/net/dns/dns_transaction.cc
@@ -219,12 +219,11 @@ class DnsUDPAttempt {
     }
     if (response_->flags() & dns_protocol::kFlagTC)
       return ERR_DNS_SERVER_REQUIRES_TCP;
-    if (response_->rcode() != dns_protocol::kRcodeNOERROR &&
-        response_->rcode() != dns_protocol::kRcodeNXDOMAIN) {
-      return ERR_DNS_SERVER_FAILED;
-    }
-    if (response_->answer_count() == 0)
+    // TODO(szym): Extract TTL for NXDOMAIN results. http://crbug.com/115051
+    if (response_->rcode() == dns_protocol::kRcodeNXDOMAIN)
       return ERR_NAME_NOT_RESOLVED;
+    if (response_->rcode() != dns_protocol::kRcodeNOERROR)
+      return ERR_DNS_SERVER_FAILED;
 
     return OK;
   }
diff --git a/net/dns/dns_transaction_unittest.cc b/net/dns/dns_transaction_unittest.cc
index 063c6ea..ded54be 100644
--- a/net/dns/dns_transaction_unittest.cc
+++ b/net/dns/dns_transaction_unittest.cc
@@ -150,8 +150,6 @@ class TransactionHelper {
       for (int i = 0; i < expected_answer_count_; ++i) {
         EXPECT_TRUE(parser.ReadRecord(&record));
       }
-      // Technically, there could be additional RRs, but not in our test data.
-      EXPECT_TRUE(parser.AtEnd());
     } else {
       EXPECT_EQ(expected_answer_count_, rv);
       EXPECT_EQ(NULL, response);
@@ -678,6 +676,42 @@ TEST_F(DnsTransactionTest, DontAppendToMultiLabelName) {
   EXPECT_TRUE(helper2.Run(transaction_factory_.get()));
 }
 
+const uint8 kResponseNoData[] = {
+  0x00, 0x00, 0x81, 0x80, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
+  // Question
+  0x01,  'x', 0x01,  'y', 0x01,  'z', 0x01,  'b', 0x00, 0x00, 0x01, 0x00, 0x01,
+  // Authority section, SOA record, TTL 0x3E6
+  0x01,  'z', 0x00, 0x00, 0x06, 0x00, 0x01, 0x00, 0x00, 0x03, 0xE6,
+  // Minimal RDATA, 18 bytes
+  0x00, 0x12,
+  0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+};
+
+TEST_F(DnsTransactionTest, SuffixSearchStop) {
+  config_.ndots = 2;
+  config_.search.push_back("a");
+  config_.search.push_back("b");
+  config_.search.push_back("c");
+  ConfigureFactory();
+
+  AddRcode("x.y.z", dns_protocol::kTypeA, dns_protocol::kRcodeNXDOMAIN);
+  AddRcode("x.y.z.a", dns_protocol::kTypeA, dns_protocol::kRcodeNXDOMAIN);
+  AddResponse("x.y.z.b",
+              dns_protocol::kTypeA,
+              0 /* id */,
+              reinterpret_cast<const char*>(kResponseNoData),
+              arraysize(kResponseNoData));
+  PrepareSockets();
+
+  TransactionHelper helper0("x.y.z", dns_protocol::kTypeA, 0 /* answers */);
+
+  EXPECT_TRUE(helper0.Run(transaction_factory_.get()));
+}
+
 }  // namespace
 
 }  // namespace net