[net/dns] Resolve AF_UNSPEC on dual-stacked systems. Sort addresses according to RFC3484.

net/dns/dns_test_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/dns/dns_test_util.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "base/sys_byteorder.h"
 #include "net/base/big_endian.h"
 #include "net/base/dns_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
+#include "net/dns/address_sorter.h"
 #include "net/dns/dns_client.h"
 #include "net/dns/dns_config_service.h"
 #include "net/dns/dns_protocol.h"
 #include "net/dns/dns_query.h"
 #include "net/dns/dns_response.h"
 #include "net/dns/dns_transaction.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 namespace {
 
-// A DnsTransaction which responds with loopback to all queries starting with
-// "ok", fails synchronously on all queries starting with "er", and NXDOMAIN to
-// all others.
+// A DnsTransaction which uses MockDnsClientRuleList to determine the response.
 class MockTransaction : public DnsTransaction,
                         public base::SupportsWeakPtr<MockTransaction> {
  public:
-  MockTransaction(const std::string& hostname,
+  MockTransaction(const MockDnsClientRuleList& rules,
+                  const std::string& hostname,
                   uint16 qtype,
                   const DnsTransactionFactory::CallbackType& callback)
-      : hostname_(hostname),
+      : result_(MockDnsClientRule::FAIL_SYNC),
+        hostname_(hostname),
         qtype_(qtype),
         callback_(callback),
         started_(false) {
+    // Find the relevant rule which matches |qtype| and prefix of |hostname|.
+    for (size_t i = 0; i < rules.size(); ++i) {
+      const std::string& prefix = rules[i].prefix;
+      if ((rules[i].qtype == qtype) &&
+          (hostname.size() >= prefix.size()) &&
+          (hostname.compare(0, prefix.size(), prefix) == 0)) {
+        result_ = rules[i].result;
+        break;
+      }
+    }
   }
 
   virtual const std::string& GetHostname() const OVERRIDE {
     return hostname_;
   }
 
   virtual uint16 GetType() const OVERRIDE {
     return qtype_;
   }
 
   virtual int Start() OVERRIDE {
     EXPECT_FALSE(started_);
     started_ = true;
-    if (hostname_.substr(0, 2) == "er")
+    if (MockDnsClientRule::FAIL_SYNC == result_)
       return ERR_NAME_NOT_RESOLVED;
     // Using WeakPtr to cleanly cancel when transaction is destroyed.
     MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(&MockTransaction::Finish, AsWeakPtr()));
     return ERR_IO_PENDING;
   }
 
  private:
   void Finish() {
-    if (hostname_.substr(0, 2) == "ok") {
-      std::string qname;
-      DNSDomainFromDot(hostname_, &qname);
-      DnsQuery query(0, qname, qtype_);
+    switch (result_) {
+      case MockDnsClientRule::EMPTY:
+      case MockDnsClientRule::OK: {
+        std::string qname;
+        DNSDomainFromDot(hostname_, &qname);
+        DnsQuery query(0, qname, qtype_);
 
-      DnsResponse response;
-      char* buffer = response.io_buffer()->data();
-      int nbytes = query.io_buffer()->size();
-      memcpy(buffer, query.io_buffer()->data(), nbytes);
+        DnsResponse response;
+        char* buffer = response.io_buffer()->data();
+        int nbytes = query.io_buffer()->size();
+        memcpy(buffer, query.io_buffer()->data(), nbytes);
+        dns_protocol::Header* header =
+            reinterpret_cast<dns_protocol::Header*>(buffer);
+        header->flags |= dns_protocol::kFlagResponse;
 
-      const uint16 kPointerToQueryName =
-          static_cast<uint16>(0xc000 | sizeof(net::dns_protocol::Header));
+        if (MockDnsClientRule::OK == result_) {
+          const uint16 kPointerToQueryName =
+              static_cast<uint16>(0xc000 | sizeof(*header));
 
-      const uint32 kTTL = 86400;  // One day.
+          const uint32 kTTL = 86400;  // One day.
 
-      // Size of RDATA which is a IPv4 or IPv6 address.
-      size_t rdata_size = qtype_ == net::dns_protocol::kTypeA ?
-                          net::kIPv4AddressSize : net::kIPv6AddressSize;
+          // Size of RDATA which is a IPv4 or IPv6 address.
+          size_t rdata_size = qtype_ == net::dns_protocol::kTypeA ?
+                              net::kIPv4AddressSize : net::kIPv6AddressSize;
 
-      // 12 is the sum of sizes of the compressed name reference, TYPE,
-      // CLASS, TTL and RDLENGTH.
-      size_t answer_size = 12 + rdata_size;
+          // 12 is the sum of sizes of the compressed name reference, TYPE,
+          // CLASS, TTL and RDLENGTH.
+          size_t answer_size = 12 + rdata_size;
 
-      // Write answer with loopback IP address.
-      reinterpret_cast<dns_protocol::Header*>(buffer)->ancount =
-          base::HostToNet16(1);
-      BigEndianWriter writer(buffer + nbytes, answer_size);
-      writer.WriteU16(kPointerToQueryName);
-      writer.WriteU16(qtype_);
-      writer.WriteU16(net::dns_protocol::kClassIN);
-      writer.WriteU32(kTTL);
-      writer.WriteU16(rdata_size);
-      if (qtype_ == net::dns_protocol::kTypeA) {
-        char kIPv4Loopback[] = { 0x7f, 0, 0, 1 };
-        writer.WriteBytes(kIPv4Loopback, sizeof(kIPv4Loopback));
-      } else {
-        char kIPv6Loopback[] = { 0, 0, 0, 0, 0, 0, 0, 0,
-                                 0, 0, 0, 0, 0, 0, 0, 1 };
-        writer.WriteBytes(kIPv6Loopback, sizeof(kIPv6Loopback));
-      }
-
-      EXPECT_TRUE(response.InitParse(nbytes + answer_size, query));
-      callback_.Run(this, OK, &response);
-    } else {
-      callback_.Run(this, ERR_NAME_NOT_RESOLVED, NULL);
+          // Write answer with loopback IP address.
+          header->ancount = base::HostToNet16(1);
+          BigEndianWriter writer(buffer + nbytes, answer_size);
+          writer.WriteU16(kPointerToQueryName);
+          writer.WriteU16(qtype_);
+          writer.WriteU16(net::dns_protocol::kClassIN);
+          writer.WriteU32(kTTL);
+          writer.WriteU16(rdata_size);
+          if (qtype_ == net::dns_protocol::kTypeA) {
+            char kIPv4Loopback[] = { 0x7f, 0, 0, 1 };
+            writer.WriteBytes(kIPv4Loopback, sizeof(kIPv4Loopback));
+          } else {
+            char kIPv6Loopback[] = { 0, 0, 0, 0, 0, 0, 0, 0,
+                                     0, 0, 0, 0, 0, 0, 0, 1 };
+            writer.WriteBytes(kIPv6Loopback, sizeof(kIPv6Loopback));
+          }
+          nbytes += answer_size;
+        }
+        EXPECT_TRUE(response.InitParse(nbytes, query));
+        callback_.Run(this, OK, &response);
+      } break;
+      case MockDnsClientRule::FAIL_ASYNC:
+        callback_.Run(this, ERR_NAME_NOT_RESOLVED, NULL);
+        break;
+      default:
+        NOTREACHED();
+        break;
     }
   }
 
+  MockDnsClientRule::Result result_;
   const std::string hostname_;
   const uint16 qtype_;
   DnsTransactionFactory::CallbackType callback_;
   bool started_;
 };
 
 
 // A DnsTransactionFactory which creates MockTransaction.
 class MockTransactionFactory : public DnsTransactionFactory {
  public:
-  MockTransactionFactory() {}
+  explicit MockTransactionFactory(const MockDnsClientRuleList& rules)
+      : rules_(rules) {}
   virtual ~MockTransactionFactory() {}
 
   virtual scoped_ptr<DnsTransaction> CreateTransaction(
       const std::string& hostname,
       uint16 qtype,
       const DnsTransactionFactory::CallbackType& callback,
       const BoundNetLog&) OVERRIDE {
     return scoped_ptr<DnsTransaction>(
-        new MockTransaction(hostname, qtype, callback));
+        new MockTransaction(rules_, hostname, qtype, callback));
+  }
+
+ private:
+  MockDnsClientRuleList rules_;
+};
+
+class MockAddressSorter : public AddressSorter {
+ public:
+  virtual ~MockAddressSorter() {}
+  virtual void Sort(const AddressList& list,
+                    const CallbackType& callback) const OVERRIDE {
+    // Do nothing.
+    callback.Run(true, list);
   }
 };
 
 // MockDnsClient provides MockTransactionFactory.
 class MockDnsClient : public DnsClient {
  public:
-  explicit MockDnsClient(const DnsConfig& config) : config_(config) {}
+  MockDnsClient(const DnsConfig& config,
+                const MockDnsClientRuleList& rules)
+      : config_(config), factory_(rules) {}
   virtual ~MockDnsClient() {}
 
   virtual void SetConfig(const DnsConfig& config) OVERRIDE {
     config_ = config;
   }
 
   virtual const DnsConfig* GetConfig() const OVERRIDE {
     return config_.IsValid() ? &config_ : NULL;
   }
 
   virtual DnsTransactionFactory* GetTransactionFactory() OVERRIDE {
     return config_.IsValid() ? &factory_ : NULL;
   }
 
+  virtual AddressSorter* GetAddressSorter() OVERRIDE {
+    return &address_sorter_;
+  }
+
  private:
   DnsConfig config_;
   MockTransactionFactory factory_;
+  MockAddressSorter address_sorter_;
 };
 
 }  // namespace
 
 // static
-scoped_ptr<DnsClient> CreateMockDnsClient(const DnsConfig& config) {
-  return scoped_ptr<DnsClient>(new MockDnsClient(config));
+scoped_ptr<DnsClient> CreateMockDnsClient(const DnsConfig& config,
+                                          const MockDnsClientRuleList& rules) {
+  return scoped_ptr<DnsClient>(new MockDnsClient(config, rules));
 }
 
 MockDnsConfigService::~MockDnsConfigService() {
 }
 
 void MockDnsConfigService::OnDNSChanged(unsigned detail) {
 }
 
 void MockDnsConfigService::ChangeConfig(const DnsConfig& config) {
   DnsConfigService::OnConfigRead(config);
 }
 
 void MockDnsConfigService::ChangeHosts(const DnsHosts& hosts) {
   DnsConfigService::OnHostsRead(hosts);
 }
 
 }  // namespace net