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

net/dns/address_sorter_posix_unittest.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/address_sorter_posix.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "net/base/net_errors.h"
+#include "net/base/net_util.h"
+#include "net/base/test_completion_callback.h"
+#include "net/socket/client_socket_factory.h"
+#include "net/udp/datagram_client_socket.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+namespace {
+
+// Used to map destination address to source address.
+typedef std::map<IPAddressNumber, IPAddressNumber> AddressMapping;
+
+IPAddressNumber ParseIP(const std::string& str) {
+  IPAddressNumber addr;
+  CHECK(ParseIPLiteralToNumber(str, &addr));
+  return addr;
+}
+
+// A mock socket which binds to source address according to AddressMapping.
+class TestUDPClientSocket : public DatagramClientSocket {
+ public:
+  explicit TestUDPClientSocket(const AddressMapping* mapping)
+      : mapping_(mapping), connected_(false)  {}
+
+  virtual ~TestUDPClientSocket() {}
+
+  virtual int Read(IOBuffer*, int, const CompletionCallback&) OVERRIDE {
+    NOTIMPLEMENTED();
+    return OK;
+  }
+  virtual int Write(IOBuffer*, int, const CompletionCallback&) OVERRIDE {
+    NOTIMPLEMENTED();
+    return OK;
+  }
+  virtual bool SetReceiveBufferSize(int32) OVERRIDE {
+    return true;
+  }
+  virtual bool SetSendBufferSize(int32) OVERRIDE {
+    return true;
+  }
+
+  virtual void Close() OVERRIDE {}
+  virtual int GetPeerAddress(IPEndPoint* address) const OVERRIDE {
+    NOTIMPLEMENTED();
+    return OK;
+  }
+  virtual int GetLocalAddress(IPEndPoint* address) const OVERRIDE {
+    if (!connected_)
+      return ERR_UNEXPECTED;
+    *address = local_endpoint_;
+    return OK;
+  }
+
+  virtual int Connect(const IPEndPoint& remote) OVERRIDE {
+    if (connected_)
+      return ERR_UNEXPECTED;
+    AddressMapping::const_iterator it = mapping_->find(remote.address());
+    if (it == mapping_->end())
+      return ERR_FAILED;
+    connected_ = true;
+    local_endpoint_ = IPEndPoint(it->second, 39874 /* arbitrary port */);
+    return OK;
+  }
+
+  virtual const BoundNetLog& NetLog() const OVERRIDE {
+    return net_log_;
+  }
+
+ private:
+  BoundNetLog net_log_;
+  const AddressMapping* mapping_;
+  bool connected_;
+  IPEndPoint local_endpoint_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestUDPClientSocket);
+};
+
+// Creates TestUDPClientSockets and maintains an AddressMapping.
+class TestSocketFactory : public ClientSocketFactory {
+ public:
+  TestSocketFactory() {}
+  virtual ~TestSocketFactory() {}
+
+  virtual DatagramClientSocket* CreateDatagramClientSocket(
+      DatagramSocket::BindType,
+      const RandIntCallback&,
+      NetLog*,
+      const NetLog::Source&) OVERRIDE {
+    return new TestUDPClientSocket(&mapping_);
+  }
+  virtual StreamSocket* CreateTransportClientSocket(
+      const AddressList&,
+      NetLog*,
+      const NetLog::Source&) OVERRIDE {
+    NOTIMPLEMENTED();
+    return NULL;
+  }
+  virtual SSLClientSocket* CreateSSLClientSocket(
+      ClientSocketHandle*,
+      const HostPortPair&,
+      const SSLConfig&,
+      const SSLClientSocketContext&) OVERRIDE {
+    NOTIMPLEMENTED();
+    return NULL;
+  }
+  virtual void ClearSSLSessionCache() OVERRIDE {
+    NOTIMPLEMENTED();
+  }
+
+  void AddMapping(const IPAddressNumber& dst, const IPAddressNumber& src) {
+    mapping_[dst] = src;
+  }
+
+ private:
+  AddressMapping mapping_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestSocketFactory);
+};
+
+void OnSortComplete(AddressList* result_buf,
+                    const CompletionCallback& callback,
+                    bool success,
+                    const AddressList& result) {
+  EXPECT_TRUE(success);
+  if (success)
+    *result_buf = result;
+  callback.Run(OK);
+}
+
+}  // namespace
+
+class AddressSorterPosixTest : public testing::Test {
+ protected:
+  AddressSorterPosixTest() : sorter_(&socket_factory_) {}
+
+  void AddMapping(const std::string& dst, const std::string& src) {
+    socket_factory_.AddMapping(ParseIP(dst), ParseIP(src));
+  }
+
+  SourceAddressInfo* GetSourceInfo(const std::string& addr) {
+    IPAddressNumber address = ParseIP(addr);
+    SourceAddressInfo* info = &sorter_.source_map_[address];
+    if (info->scope == SCOPE_UNDEFINED)
+      sorter_.FillPolicy(address, info);
+    return info;
+  }
+
+  // Verify that NULL-terminated |addresses| matches (-1)-terminated |order|
+  // after sorting.
+  void Verify(const char* addresses[], const int order[]) {
+    AddressList list;
+    for (const char** addr = addresses; *addr != NULL; ++addr)
+      list.push_back(IPEndPoint(ParseIP(*addr), 80));
+    for (size_t i = 0; order[i] >= 0; ++i)
+      CHECK_LT(order[i], static_cast<int>(list.size()));
+
+    AddressList result;
+    TestCompletionCallback callback;
+    sorter_.Sort(list, base::Bind(&OnSortComplete, &result,
+                                  callback.callback()));
+    callback.WaitForResult();
+
+    for (size_t i = 0; (i < result.size()) || (order[i] >= 0); ++i) {
+      IPEndPoint expected = order[i] >= 0 ? list[order[i]] : IPEndPoint();
+      IPEndPoint actual = i < result.size() ? result[i] : IPEndPoint();
+      EXPECT_TRUE(expected.address() == actual.address()) <<
+          "Address out of order at position " << i << "\n" <<
+          "  Actual: " << actual.ToStringWithoutPort() << "\n" <<
+          "Expected: " << expected.ToStringWithoutPort();
+    }
+  }
+
+  TestSocketFactory socket_factory_;
+  AddressSorterPosix sorter_;
+};
+
+// Rule 1: Avoid unusable destinations.
+TEST_F(AddressSorterPosixTest, Rule1) {
+  AddMapping("10.0.0.231", "10.0.0.1");
+  const char* addresses[] = { "::1", "10.0.0.231", "127.0.0.1", NULL };
+  const int order[] = { 1, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 2: Prefer matching scope.
+TEST_F(AddressSorterPosixTest, Rule2) {
+  AddMapping("3002::1", "4000::10");      // matching global
+  AddMapping("ff32::1", "fe81::10");      // matching link-local
+  AddMapping("fec1::1", "fec1::10");      // matching node-local
+  AddMapping("3002::2", "::1");           // global vs. link-local
+  AddMapping("fec1::2", "fe81::10");      // site-local vs. link-local
+  AddMapping("8.0.0.1", "169.254.0.10");  // global vs. link-local
+  // In all three cases, matching scope is preferred.
+  const int order[] = { 1, 0, -1 };
+  const char* addresses1[] = { "3002::2", "3002::1", NULL };
+  Verify(addresses1, order);
+  const char* addresses2[] = { "fec1::2", "ff32::1", NULL };
+  Verify(addresses2, order);
+  const char* addresses3[] = { "8.0.0.1", "fec1::1", NULL };
+  Verify(addresses3, order);
+}
+
+// Rule 3: Avoid deprecated addresses.
+TEST_F(AddressSorterPosixTest, Rule3) {
+  // Matching scope.
+  AddMapping("3002::1", "4000::10");
+  GetSourceInfo("4000::10")->deprecated = true;
+  AddMapping("3002::2", "4000::20");
+  const char* addresses[] = { "3002::1", "3002::2", NULL };
+  const int order[] = { 1, 0, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 4: Prefer home addresses.
+TEST_F(AddressSorterPosixTest, Rule4) {
+  AddMapping("3002::1", "4000::10");
+  AddMapping("3002::2", "4000::20");
+  GetSourceInfo("4000::20")->home = true;
+  const char* addresses[] = { "3002::1", "3002::2", NULL };
+  const int order[] = { 1, 0, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 5: Prefer matching label.
+TEST_F(AddressSorterPosixTest, Rule5) {
+  AddMapping("::1", "::1");                       // matching loopback
+  AddMapping("::ffff:1234:1", "::ffff:1234:10");  // matching IPv4-mapped
+  AddMapping("2001::1", "::ffff:1234:10");        // Teredo vs. IPv4-mapped
+  AddMapping("2002::1", "2001::10");              // 6to4 vs. Teredo
+  const int order[] = { 1, 0, -1 };
+  {
+    const char* addresses[] = { "2001::1", "::1", NULL };
+    Verify(addresses, order);
+  }
+  {
+    const char* addresses[] = { "2002::1", "::ffff:1234:1", NULL };
+    Verify(addresses, order);
+  }
+}
+
+// Rule 6: Prefer higher precedence.
+TEST_F(AddressSorterPosixTest, Rule6) {
+  AddMapping("::1", "::1");                       // loopback
+  AddMapping("ff32::1", "fe81::10");              // multicast
+  AddMapping("::ffff:1234:1", "::ffff:1234:10");  // IPv4-mapped
+  AddMapping("2001::1", "2001::10");              // Teredo
+  const char* addresses[] = { "2001::1", "::ffff:1234:1", "ff32::1", "::1",
+                              NULL };
+  const int order[] = { 3, 2, 1, 0, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 7: Prefer native transport.
+TEST_F(AddressSorterPosixTest, Rule7) {
+  AddMapping("3002::1", "4000::10");
+  AddMapping("3002::2", "4000::20");
+  GetSourceInfo("4000::20")->native = true;
+  const char* addresses[] = { "3002::1", "3002::2", NULL };
+  const int order[] = { 1, 0, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 8: Prefer smaller scope.
+TEST_F(AddressSorterPosixTest, Rule8) {
+  // Matching scope. Should precede the others by Rule 2.
+  AddMapping("fe81::1", "fe81::10");      // link-local
+  AddMapping("3000::1", "4000::10");      // global
+  // Mismatched scope.
+  AddMapping("ff32::1", "4000::10");      // link-local
+  AddMapping("ff35::1", "4000::10");      // site-local
+  AddMapping("ff38::1", "4000::10");      // org-local

[mmenke, 2012/08/13 20:11:50]

nit:  Two spaces before comments.

+  const char* addresses[] = { "ff38::1", "3000::1", "ff35::1", "ff32::1",
+                              "fe81::1", NULL };
+  const int order[] = { 4, 1, 3, 2, 0, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 9: Use longest matching prefix.
+TEST_F(AddressSorterPosixTest, Rule9) {
+  AddMapping("3000::1", "3000:ffff::10");  // 16 bit match
+  GetSourceInfo("3000:ffff::10")->prefix_length = 16;
+  AddMapping("4000::1", "4000::10");       // 123 bit match, limited to 15
+  GetSourceInfo("4000::10")->prefix_length = 15;
+  AddMapping("4002::1", "4000::10");       // 14 bit match
+  AddMapping("4080::1", "4000::10");       // 8 bit match
+  const char* addresses[] = { "4080::1", "4002::1", "4000::1", "3000::1",
+                              NULL };
+  const int order[] = { 3, 2, 1, 0, -1 };
+  Verify(addresses, order);
+}
+
+// Rule 10: Leave the order unchanged.
+TEST_F(AddressSorterPosixTest, Rule10) {
+  AddMapping("4000::1", "4000::10");
+  AddMapping("4000::2", "4000::10");
+  AddMapping("4000::3", "4000::10");
+  const char* addresses[] = { "4000::1", "4000::2", "4000::3", NULL };
+  const int order[] = { 0, 1, 2, -1 };
+  Verify(addresses, order);
+}
+
+TEST_F(AddressSorterPosixTest, MultipleRules) {
+  AddMapping("::1", "::1");           // loopback
+  AddMapping("ff32::1", "fe81::10");  // link-local multicast
+  AddMapping("ff3e::1", "4000::10");  // global multicast
+  AddMapping("4000::1", "4000::10");  // global unicast
+  AddMapping("ff32::2", "fe81::20");  // deprecated link-local multicast
+  GetSourceInfo("fe81::20")->deprecated = true;
+  const char* addresses[] = { "ff3e::1", "ff32::2", "4000::1", "ff32::1", "::1",
+                              "8.0.0.1", NULL };
+  const int order[] = { 4, 3, 0, 2, 1, -1 };
+  Verify(addresses, order);
+}
+
+}  // namespace net