Isolates generic DnsClient from AsyncHostResolver.

DnsClient provides a generic DNS client that allows fetching resource records. 
DnsClient is very lightweight and does not support aggregation, queuing or 
prioritization of requests. 

This is the first CL in a series to merge AsyncHostResolver into 
HostResolverImpl. 

Also introduces general-purpose BigEndianReader/Writer.

Removes DnsTransactionTest-related suppressions.

BUG=90881,80225,106688
TEST=./net_unittests


Review URL: http://codereview.chromium.org/8852009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113640 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 31 insertions, 72 deletions

diff --git a/net/dns/dns_query_unittest.cc b/net/dns/dns_query_unittest.cc
index d43cf8be..ffe02e7 100644
--- a/net/dns/dns_query_unittest.cc
+++ b/net/dns/dns_query_unittest.cc
@@ -5,58 +5,21 @@
 #include "net/dns/dns_query.h"
 
 #include "base/bind.h"
-#include "base/rand_util.h"
 #include "net/base/dns_util.h"
 #include "net/base/io_buffer.h"
+#include "net/dns/dns_protocol.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 
-// DNS query consists of a header followed by a question.  Header format
-// and question format are described below.  For the meaning of specific
-// fields, please see RFC 1035.
+namespace {
 
-// Header format.
-//                                  1  1  1  1  1  1
-//    0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                      ID                       |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                    QDCOUNT                    |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                    ANCOUNT                    |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                    NSCOUNT                    |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                    ARCOUNT                    |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-
-// Question format.
-//                                  1  1  1  1  1  1
-//    0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                                               |
-//  /                     QNAME                     /
-//  /                                               /
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                     QTYPE                     |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-//  |                     QCLASS                    |
-//  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-
-TEST(DnsQueryTest, ConstructorTest) {
-  std::string kQname("\003www\006google\003com", 16);
-  DnsQuery q1(kQname, kDNS_A, base::Bind(&base::RandInt));
-  EXPECT_EQ(kDNS_A, q1.qtype());
-
-  uint8 id_hi = q1.id() >> 8, id_lo = q1.id() & 0xff;
-
-  // See the top of the file for the description of a DNS query.
+TEST(DnsQueryTest, Constructor) {
+  // This includes \0 at the end.
+  const char qname_data[] = "\x03""www""\x07""example""\x03""com";
   const uint8 query_data[] = {
     // Header
-    id_hi, id_lo,
+    0xbe, 0xef,
     0x01, 0x00,               // Flags -- set RD (recursion desired) bit.
     0x00, 0x01,               // Set QDCOUNT (question count) to 1, all the
                               // rest are 0 for a query.
@@ -65,46 +28,42 @@ TEST(DnsQueryTest, ConstructorTest) {
     0x00, 0x00,
 
     // Question
-    0x03, 0x77, 0x77, 0x77,   // QNAME: www.google.com in DNS format.
-    0x06, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65,
-    0x03, 0x63, 0x6f, 0x6d, 0x00,
+    0x03, 'w', 'w', 'w',      // QNAME: www.example.com in DNS format.
+    0x07, 'e', 'x', 'a', 'm', 'p', 'l', 'e',
+    0x03, 'c', 'o', 'm',
+    0x00,
 
     0x00, 0x01,               // QTYPE: A query.
     0x00, 0x01,               // QCLASS: IN class.
   };
 
-  int expected_size = arraysize(query_data);
-  EXPECT_EQ(expected_size, q1.io_buffer()->size());
-  EXPECT_EQ(0, memcmp(q1.io_buffer()->data(), query_data, expected_size));
+  base::StringPiece qname(qname_data, sizeof(qname_data));
+  DnsQuery q1(0xbeef, qname, dns_protocol::kTypeA);
+  EXPECT_EQ(dns_protocol::kTypeA, q1.qtype());
+
+  ASSERT_EQ(static_cast<int>(sizeof(query_data)), q1.io_buffer()->size());
+  EXPECT_EQ(0, memcmp(q1.io_buffer()->data(), query_data, sizeof(query_data)));
+  EXPECT_EQ(qname, q1.qname());
+
+  base::StringPiece question(reinterpret_cast<const char*>(query_data) + 12,
+                             21);
+  EXPECT_EQ(question, q1.question());
 }
 
-TEST(DnsQueryTest, CloneTest) {
-  std::string kQname("\003www\006google\003com", 16);
-  DnsQuery q1(kQname, kDNS_A, base::Bind(&base::RandInt));
+TEST(DnsQueryTest, Clone) {
+  // This includes \0 at the end.
+  const char qname_data[] = "\x03""www""\x07""example""\x03""com";
+  base::StringPiece qname(qname_data, sizeof(qname_data));
 
-  scoped_ptr<DnsQuery> q2(q1.CloneWithNewId());
+  DnsQuery q1(0, qname, dns_protocol::kTypeA);
+  EXPECT_EQ(0, q1.id());
+  scoped_ptr<DnsQuery> q2(q1.CloneWithNewId(42));
+  EXPECT_EQ(42, q2->id());
   EXPECT_EQ(q1.io_buffer()->size(), q2->io_buffer()->size());
   EXPECT_EQ(q1.qtype(), q2->qtype());
-  EXPECT_EQ(q1.question_size(), q2->question_size());
-  EXPECT_EQ(0, memcmp(q1.question_data(), q2->question_data(),
-                      q1.question_size()));
+  EXPECT_EQ(q1.question(), q2->question());
 }
 
-TEST(DnsQueryTest, RandomIdTest) {
-  std::string kQname("\003www\006google\003com", 16);
-
-  // Since id fields are 16-bit values, we iterate to reduce the
-  // probability of collision, to avoid a flaky test.
-  bool ids_are_random = false;
-  for (int i = 0; i < 1000; ++i) {
-    DnsQuery q1(kQname, kDNS_A, base::Bind(&base::RandInt));
-    DnsQuery q2(kQname, kDNS_A, base::Bind(&base::RandInt));
-    scoped_ptr<DnsQuery> q3(q1.CloneWithNewId());
-    ids_are_random = q1.id () != q2.id() && q1.id() != q3->id();
-    if (ids_are_random)
-      break;
-  }
-  EXPECT_TRUE(ids_are_random);
-}
+}  // namespace
 
 }  // namespace net