net/dns/dns_test_util.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/dns/dns_test_util.h"
   6
   7 #include <string>
   8
   9 #include "base/big_endian.h"
  10 #include "base/bind.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/sys_byteorder.h"
  14 #include "net/base/dns_util.h"
  15 #include "net/base/io_buffer.h"
  16 #include "net/base/net_errors.h"
  17 #include "net/dns/address_sorter.h"
  18 #include "net/dns/dns_query.h"
  19 #include "net/dns/dns_response.h"
  20 #include "net/dns/dns_transaction.h"
  21 #include "testing/gtest/include/gtest/gtest.h"
  22
  23 namespace net {
  24 namespace {
  25
  26 class MockAddressSorter : public AddressSorter {
  27  public:
  28   ~MockAddressSorter() override {}
  29   void Sort(const AddressList& list,
  30             const CallbackType& callback) const override {
  31     // Do nothing.
  32     callback.Run(true, list);
  33   }
  34 };
  35
  36 // A DnsTransaction which uses MockDnsClientRuleList to determine the response.
  37 class MockTransaction : public DnsTransaction,
  38                         public base::SupportsWeakPtr<MockTransaction> {
  39  public:
  40   MockTransaction(const MockDnsClientRuleList& rules,
  41                   const std::string& hostname,
  42                   uint16 qtype,
  43                   const DnsTransactionFactory::CallbackType& callback)
  44       : result_(MockDnsClientRule::FAIL),
  45         hostname_(hostname),
  46         qtype_(qtype),
  47         callback_(callback),
  48         started_(false),
  49         delayed_(false) {
  50     // Find the relevant rule which matches |qtype| and prefix of |hostname|.
  51     for (size_t i = 0; i < rules.size(); ++i) {
  52       const std::string& prefix = rules[i].prefix;
  53       if ((rules[i].qtype == qtype) &&
  54           (hostname.size() >= prefix.size()) &&
  55           (hostname.compare(0, prefix.size(), prefix) == 0)) {
  56         result_ = rules[i].result;
  57         delayed_ = rules[i].delay;
  58         break;
  59       }
  60     }
  61   }
  62
  63   virtual const std::string& GetHostname() const override {
  64     return hostname_;
  65   }
  66
  67   virtual uint16 GetType() const override {
  68     return qtype_;
  69   }
  70
  71   virtual void Start() override {
  72     EXPECT_FALSE(started_);
  73     started_ = true;
  74     if (delayed_)
  75       return;
  76     // Using WeakPtr to cleanly cancel when transaction is destroyed.
  77     base::MessageLoop::current()->PostTask(
  78         FROM_HERE, base::Bind(&MockTransaction::Finish, AsWeakPtr()));
  79   }
  80
  81   void FinishDelayedTransaction() {
  82     EXPECT_TRUE(delayed_);
  83     delayed_ = false;
  84     Finish();
  85   }
  86
  87   bool delayed() const { return delayed_; }
  88
  89  private:
  90   void Finish() {
  91     switch (result_) {
  92       case MockDnsClientRule::EMPTY:
  93       case MockDnsClientRule::OK: {
  94         std::string qname;
  95         DNSDomainFromDot(hostname_, &qname);
  96         DnsQuery query(0, qname, qtype_);
  97
  98         DnsResponse response;
  99         char* buffer = response.io_buffer()->data();
 100         int nbytes = query.io_buffer()->size();
 101         memcpy(buffer, query.io_buffer()->data(), nbytes);
 102         dns_protocol::Header* header =
 103             reinterpret_cast<dns_protocol::Header*>(buffer);
 104         header->flags |= dns_protocol::kFlagResponse;
 105
 106         if (MockDnsClientRule::OK == result_) {
 107           const uint16 kPointerToQueryName =
 108               static_cast<uint16>(0xc000 | sizeof(*header));
 109
 110           const uint32 kTTL = 86400;  // One day.
 111
 112           // Size of RDATA which is a IPv4 or IPv6 address.
 113           size_t rdata_size = qtype_ == net::dns_protocol::kTypeA ?
 114                               net::kIPv4AddressSize : net::kIPv6AddressSize;
 115
 116           // 12 is the sum of sizes of the compressed name reference, TYPE,
 117           // CLASS, TTL and RDLENGTH.
 118           size_t answer_size = 12 + rdata_size;
 119
 120           // Write answer with loopback IP address.
 121           header->ancount = base::HostToNet16(1);
 122           base::BigEndianWriter writer(buffer + nbytes, answer_size);
 123           writer.WriteU16(kPointerToQueryName);
 124           writer.WriteU16(qtype_);
 125           writer.WriteU16(net::dns_protocol::kClassIN);
 126           writer.WriteU32(kTTL);
 127           writer.WriteU16(rdata_size);
 128           if (qtype_ == net::dns_protocol::kTypeA) {
 129             char kIPv4Loopback[] = { 0x7f, 0, 0, 1 };
 130             writer.WriteBytes(kIPv4Loopback, sizeof(kIPv4Loopback));
 131           } else {
 132             char kIPv6Loopback[] = { 0, 0, 0, 0, 0, 0, 0, 0,
 133                                      0, 0, 0, 0, 0, 0, 0, 1 };
 134             writer.WriteBytes(kIPv6Loopback, sizeof(kIPv6Loopback));
 135           }
 136           nbytes += answer_size;
 137         }
 138         EXPECT_TRUE(response.InitParse(nbytes, query));
 139         callback_.Run(this, OK, &response);
 140       } break;
 141       case MockDnsClientRule::FAIL:
 142         callback_.Run(this, ERR_NAME_NOT_RESOLVED, NULL);
 143         break;
 144       case MockDnsClientRule::TIMEOUT:
 145         callback_.Run(this, ERR_DNS_TIMED_OUT, NULL);
 146         break;
 147       default:
 148         NOTREACHED();
 149         break;
 150     }
 151   }
 152
 153   MockDnsClientRule::Result result_;
 154   const std::string hostname_;
 155   const uint16 qtype_;
 156   DnsTransactionFactory::CallbackType callback_;
 157   bool started_;
 158   bool delayed_;
 159 };
 160
 161 }  // namespace
 162
 163 // A DnsTransactionFactory which creates MockTransaction.
 164 class MockTransactionFactory : public DnsTransactionFactory {
 165  public:
 166   explicit MockTransactionFactory(const MockDnsClientRuleList& rules)
 167       : rules_(rules) {}
 168
 169   ~MockTransactionFactory() override {}
 170
 171   scoped_ptr<DnsTransaction> CreateTransaction(
 172       const std::string& hostname,
 173       uint16 qtype,
 174       const DnsTransactionFactory::CallbackType& callback,
 175       const BoundNetLog&) override {
 176     MockTransaction* transaction =
 177         new MockTransaction(rules_, hostname, qtype, callback);
 178     if (transaction->delayed())
 179       delayed_transactions_.push_back(transaction->AsWeakPtr());
 180     return scoped_ptr<DnsTransaction>(transaction);
 181   }
 182
 183   void CompleteDelayedTransactions() {
 184     DelayedTransactionList old_delayed_transactions;
 185     old_delayed_transactions.swap(delayed_transactions_);
 186     for (DelayedTransactionList::iterator it = old_delayed_transactions.begin();
 187          it != old_delayed_transactions.end(); ++it) {
 188       if (it->get())
 189         (*it)->FinishDelayedTransaction();
 190     }
 191   }
 192
 193  private:
 194   typedef std::vector<base::WeakPtr<MockTransaction> > DelayedTransactionList;
 195
 196   MockDnsClientRuleList rules_;
 197   DelayedTransactionList delayed_transactions_;
 198 };
 199
 200 MockDnsClient::MockDnsClient(const DnsConfig& config,
 201                              const MockDnsClientRuleList& rules)
 202       : config_(config),
 203         factory_(new MockTransactionFactory(rules)),
 204         address_sorter_(new MockAddressSorter()) {
 205 }
 206
 207 MockDnsClient::~MockDnsClient() {}
 208
 209 void MockDnsClient::SetConfig(const DnsConfig& config) {
 210   config_ = config;
 211 }
 212
 213 const DnsConfig* MockDnsClient::GetConfig() const {
 214   return config_.IsValid() ? &config_ : NULL;
 215 }
 216
 217 DnsTransactionFactory* MockDnsClient::GetTransactionFactory() {
 218   return config_.IsValid() ? factory_.get() : NULL;
 219 }
 220
 221 AddressSorter* MockDnsClient::GetAddressSorter() {
 222   return address_sorter_.get();
 223 }
 224
 225 void MockDnsClient::CompleteDelayedTransactions() {
 226   factory_->CompleteDelayedTransactions();
 227 }
 228
 229 }  // namespace net