Adds support for the DHCP portion of the WPAD (proxy auto-discovery) protocol.

net/proxy/dhcp_proxy_script_fetcher_win_unittest.cc

+// Copyright (c) 2011 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/proxy/dhcp_proxy_script_fetcher_win.h"
+
+#include <vector>
+
+#include "base/message_loop.h"
+#include "base/perftimer.h"
+#include "base/rand_util.h"
+#include "base/threading/platform_thread.h"
+#include "net/base/completion_callback.h"
+#include "net/proxy/dhcp_proxy_script_adapter_fetcher_win.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace {
+
+TEST(WindowsDhcpProxyScriptFetcher, AdapterNamesAndPacURLFromDhcp) {
+  // This tests our core Win32 implementation without any of the wrappers
+  // we layer on top to achieve asynchronous and parallel operations.
+  //
+  // We don't make assumptions about the environment this unit test is
+  // running in, so it just exercises the code to make sure there
+  // is no crash and no error returned, but does not assert on the number
+  // of interfaces or the information returned via DHCP.
+  std::set<std::string> adapter_names;
+  WindowsDhcpProxyScriptFetcher::GetCandidateAdapterNames(&adapter_names);
+  for (std::set<std::string>::iterator it = adapter_names.begin();

[eroman, 2011/05/17 04:39:39]

nit: const_iterator ?

[Jói, 2011/05/17 15:38:35]

Done.

+       it != adapter_names.end();
+       ++it) {
+    const std::string& adapter_name = *it;
+    std::string pac_url =
+        DhcpProxyScriptAdapterFetcher::GetPacURLFromDhcp(adapter_name);
+    printf("Adapter '%s' has PAC URL '%s' configured in DHCP.\n",
+           adapter_name.c_str(),
+           pac_url.c_str());
+  }
+}
+
+// Helper for RealFetch* tests below.
+class RealFetchTester {
+ public:
+  RealFetchTester()
+      : context_((new TestURLRequestContext())),
+        fetcher_(new WindowsDhcpProxyScriptFetcher(context_.get())),
+        finished_(false),
+        ALLOW_THIS_IN_INITIALIZER_LIST(
+            completion_callback_(this, &RealFetchTester::OnCompletion)),
+        on_completion_is_error_(false) {
+    // Make sure the test ends.
+    timeout_.Start(
+        base::TimeDelta::FromSeconds(5), this, &RealFetchTester::OnTimeout);
+  }
+
+  void RunTest() {
+    fetcher_->Fetch(&pac_text_, &completion_callback_);
+  }
+
+  void RunTestWithCancel() {
+    RunTest();
+    fetcher_->Cancel();
+  }
+
+  void RunTestWithDeferredCancel() {
+    RunTest();
+    cancel_timer_.Start(base::TimeDelta::FromMilliseconds(1),
+                        this, &RealFetchTester::OnCancelTimer);
+  }
+
+  void OnCompletion(int result) {
+    if (on_completion_is_error_) {
+      FAIL() << "Received completion for test in which this is error.";
+    }
+    finished_ = true;
+    printf("Result code %d PAC data length %d\n", result, pac_text_.size());
+  }
+
+  void OnTimeout() {
+    printf("Timeout!");
+    OnCompletion(0);
+  }
+
+  void OnCancelTimer() {
+    fetcher_->Cancel();
+    finished_ = true;
+  }
+
+  void WaitUntilDone() {
+    while (!finished_) {
+      MessageLoop::current()->RunAllPending();
+    }
+    MessageLoop::current()->RunAllPending();
+  }
+
+  // Attempts to give worker threads time to finish.  This is currently
+  // very simplistic as completion (via completion callback or cancellation)
+  // immediately "detaches" any worker threads, so the best we can do is give
+  // them a little time.  If we start running into Valgrind leaks, we can
+  // do something a bit more clever to track worker threads even when the
+  // WindowsDhcpProxyScriptFetcher state machine has finished.
+  void FinishTestAllowCleanup() {
+    base::PlatformThread::Sleep(30);
+  }
+
+  scoped_refptr<URLRequestContext> context_;
+  scoped_ptr<WindowsDhcpProxyScriptFetcher> fetcher_;
+  bool finished_;
+  string16 pac_text_;
+  CompletionCallbackImpl<RealFetchTester> completion_callback_;
+  base::OneShotTimer<RealFetchTester> timeout_;
+  base::OneShotTimer<RealFetchTester> cancel_timer_;
+  bool on_completion_is_error_;
+};
+
+TEST(WindowsDhcpProxyScriptFetcher, RealFetch) {
+  // This tests a call to Fetch() with no stubbing out of dependencies.
+  //
+  // We don't make assumptions about the environment this unit test is
+  // running in, so it just exercises the code to make sure there
+  // is no crash and no unexpected error returned, but does not assert on
+  // results beyond that.
+  RealFetchTester fetcher;
+  fetcher.RunTest();
+
+  fetcher.WaitUntilDone();
+  printf("PAC URL was %s\n",
+      fetcher.fetcher_->GetPacURL().possibly_invalid_spec().c_str());
+
+  fetcher.FinishTestAllowCleanup();
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, RealFetchWithCancel) {
+  // Does a Fetch() with an immediate cancel.  As before, just
+  // exercises the code without stubbing out dependencies.
+  RealFetchTester fetcher;
+  fetcher.RunTestWithCancel();
+  MessageLoop::current()->RunAllPending();
+
+  // Attempt to avoid Valgrind leak reports in case worker thread is
+  // still running.
+  fetcher.FinishTestAllowCleanup();
+}
+
+// For RealFetchWithDeferredCancel, below.
+class DelayingDhcpProxyScriptAdapterFetcher
+    : public DhcpProxyScriptAdapterFetcher {
+ public:
+  explicit DelayingDhcpProxyScriptAdapterFetcher(
+      URLRequestContext* url_request_context)
+      : DhcpProxyScriptAdapterFetcher(url_request_context) {
+  }
+
+  class DelayingWorkerThread : public WorkerThread {
+   public:
+    explicit DelayingWorkerThread(
+        const base::WeakPtr<DhcpProxyScriptAdapterFetcher>& owner)
+        : WorkerThread(owner) {
+    }
+
+    std::string ImplGetPacURLFromDhcp(
+        const std::string& adapter_name) OVERRIDE {
+      base::PlatformThread::Sleep(20);
+      return WorkerThread::ImplGetPacURLFromDhcp(adapter_name);
+    }
+  };
+
+  WorkerThread* ImplCreateWorkerThread(
+      const base::WeakPtr<DhcpProxyScriptAdapterFetcher>& owner) OVERRIDE {
+    return new DelayingWorkerThread(owner);
+  }
+};
+
+// For RealFetchWithDeferredCancel, below.
+class DelayingWindowsDhcpProxyScriptFetcher
+    : public WindowsDhcpProxyScriptFetcher {
+ public:
+  explicit DelayingWindowsDhcpProxyScriptFetcher(
+      URLRequestContext* context)
+      : WindowsDhcpProxyScriptFetcher(context) {
+  }
+
+  DhcpProxyScriptAdapterFetcher* ImplCreateAdapterFetcher() OVERRIDE {
+    return new DelayingDhcpProxyScriptAdapterFetcher(url_request_context_);
+  }
+};
+
+TEST(WindowsDhcpProxyScriptFetcher, RealFetchWithDeferredCancel) {
+  // Does a Fetch() with a slightly delayed cancel.  As before, just
+  // exercises the code without stubbing out dependencies, but
+  // introduces a guaranteed 20 ms delay on the worker threads so that
+  // the cancel is called before they complete.
+  RealFetchTester fetcher;
+  fetcher.fetcher_.reset(
+      new DelayingWindowsDhcpProxyScriptFetcher(fetcher.context_));
+  fetcher.on_completion_is_error_ = true;
+  fetcher.RunTestWithDeferredCancel();
+  fetcher.WaitUntilDone();
+}
+
+// The remaining tests are to exercise our state machine in various
+// situations, with actual network access fully stubbed out.
+
+class DummyDhcpProxyScriptAdapterFetcher
+    : public DhcpProxyScriptAdapterFetcher {
+ public:
+  DummyDhcpProxyScriptAdapterFetcher()
+      : DhcpProxyScriptAdapterFetcher(new TestURLRequestContext()),
+        did_finish_(false),
+        result_(OK),
+        pac_script_(L"bingo"),
+        fetch_delay_ms_(1),
+        client_callback_(NULL) {
+  }
+
+  void Fetch(const std::string& adapter_name,
+             CompletionCallback* callback) OVERRIDE {
+    client_callback_ = callback;
+    timer_.Start(base::TimeDelta::FromMilliseconds(fetch_delay_ms_),
+                 this, &DummyDhcpProxyScriptAdapterFetcher::OnTimer);
+  }
+
+  void Cancel() OVERRIDE {
+    timer_.Stop();
+  }
+
+  bool DidFinish() const OVERRIDE {
+    return did_finish_;
+  }
+
+  int GetResult() const OVERRIDE {
+    return result_;
+  }
+
+  string16 GetPacScript() const OVERRIDE {
+    return pac_script_;
+  }
+
+  void OnTimer() {
+    client_callback_->Run(result_);
+  }
+
+  void Configure(
+      bool did_finish, int result, string16 pac_script, int fetch_delay_ms) {
+    did_finish_ = did_finish;
+    result_ = result;
+    pac_script_ = pac_script;
+    fetch_delay_ms_ = fetch_delay_ms;
+  }
+
+ private:
+  bool did_finish_;
+  int result_;
+  string16 pac_script_;
+  int fetch_delay_ms_;
+  CompletionCallback* client_callback_;
+  base::OneShotTimer<DummyDhcpProxyScriptAdapterFetcher> timer_;
+};
+
+class MockWindowsDhcpProxyScriptFetcher : public WindowsDhcpProxyScriptFetcher {
+ public:
+  MockWindowsDhcpProxyScriptFetcher()
+      : WindowsDhcpProxyScriptFetcher(new TestURLRequestContext()),
+        next_adapter_fetcher_index_(0) {
+  }
+
+  // Adds a fetcher object to the queue of fetchers used by
+  // |ImplCreateAdapterFetcher()|, and its name to the list of adapters
+  // returned by ImplGetCandidateAdapterNames.
+  void PushBackAdapter(const std::string& adapter_name,
+                       DhcpProxyScriptAdapterFetcher* fetcher) {
+    adapter_names_.push_back(adapter_name);
+    adapter_fetchers_.push_back(fetcher);
+  }
+
+  void ConfigureAndPushBackAdapter(const std::string& adapter_name,
+                                   bool did_finish,
+                                   int result,
+                                   string16 pac_script,
+                                   int fetch_delay_ms) {
+    scoped_ptr<DummyDhcpProxyScriptAdapterFetcher> adapter_fetcher(
+        new DummyDhcpProxyScriptAdapterFetcher());
+    adapter_fetcher->Configure(did_finish, result, pac_script, fetch_delay_ms);
+    PushBackAdapter(adapter_name, adapter_fetcher.release());
+  }
+
+  DhcpProxyScriptAdapterFetcher* ImplCreateAdapterFetcher() OVERRIDE {
+    return adapter_fetchers_[next_adapter_fetcher_index_++];
+  }
+
+  bool ImplGetCandidateAdapterNames(
+      std::set<std::string>* adapter_names) OVERRIDE {
+    adapter_names->insert(adapter_names_.begin(), adapter_names_.end());
+    return true;
+  }
+
+  int ImplGetMaxWaitMs() OVERRIDE {
+    return 25;
+  }
+
+  void ResetTestState() {
+    next_adapter_fetcher_index_ = 0;
+    adapter_fetchers_.clear();
+    // String pointers contained herein will have been freed during test.
+    adapter_names_.clear();
+  }
+
+  int next_adapter_fetcher_index_;
+
+  // Ownership is not here; it gets transferred to the implementation
+  // class via ImplCreateAdapterFetcher.
+  std::vector<DhcpProxyScriptAdapterFetcher*> adapter_fetchers_;
+
+  std::vector<std::string> adapter_names_;
+};
+
+class FetcherClient {
+public:
+  FetcherClient()
+      : finished_(false),
+        result_(ERR_UNEXPECTED),
+        ALLOW_THIS_IN_INITIALIZER_LIST(
+            completion_callback_(this, &FetcherClient::OnCompletion)) {
+  }
+
+  void RunTest() {
+    int result = fetcher_.Fetch(&pac_text_, &completion_callback_);
+    ASSERT_EQ(ERR_IO_PENDING, result);
+  }
+
+  void RunImmediateReturnTest() {
+    int result = fetcher_.Fetch(&pac_text_, &completion_callback_);
+    ASSERT_EQ(ERR_PAC_NOT_IN_DHCP, result);
+  }
+
+  void RunMessageLoopUntilComplete() {
+    while (!finished_) {
+      MessageLoop::current()->RunAllPending();
+    }
+    MessageLoop::current()->RunAllPending();
+  }
+
+  void OnCompletion(int result) {
+    finished_ = true;
+    result_ = result;
+  }
+
+  void ResetTestState() {
+    finished_ = false;
+    result_ = ERR_UNEXPECTED;
+    pac_text_ = L"";
+    fetcher_.ResetTestState();
+  }
+
+  MockWindowsDhcpProxyScriptFetcher fetcher_;
+  bool finished_;
+  int result_;
+  string16 pac_text_;
+  CompletionCallbackImpl<FetcherClient> completion_callback_;
+};
+
+// We separate out each test's logic so that we can easily implement
+// the ReuseFetcher test at the bottom.
+void TestNormalCaseURLConfiguredOneAdapter(FetcherClient* client) {
+  scoped_ptr<DummyDhcpProxyScriptAdapterFetcher> adapter_fetcher(
+      new DummyDhcpProxyScriptAdapterFetcher());
+  adapter_fetcher->Configure(true, OK, L"bingo", 1);
+  client->fetcher_.PushBackAdapter("a", adapter_fetcher.release());
+  client->RunTest();
+  client->RunMessageLoopUntilComplete();
+  ASSERT_EQ(OK, client->result_);
+  ASSERT_EQ(L"bingo", client->pac_text_);
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, NormalCaseURLConfiguredOneAdapter) {
+  FetcherClient client;
+  TestNormalCaseURLConfiguredOneAdapter(&client);
+}
+
+void TestNormalCaseURLConfiguredMultipleAdapters(FetcherClient* client) {
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "most_preferred", true, ERR_PAC_NOT_IN_DHCP, L"", 1);
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "second", true, OK, L"bingo", 50);
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "third", true, OK, L"rocko", 1);
+  client->RunTest();
+  client->RunMessageLoopUntilComplete();
+  ASSERT_EQ(OK, client->result_);
+  ASSERT_EQ(L"bingo", client->pac_text_);
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, NormalCaseURLConfiguredMultipleAdapters) {
+  FetcherClient client;
+  TestNormalCaseURLConfiguredMultipleAdapters(&client);
+}
+
+void TestNormalCaseURLConfiguredMultipleAdaptersWithTimeout(
+    FetcherClient* client) {
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "most_preferred", true, ERR_PAC_NOT_IN_DHCP, L"", 1);
+  // This will time out.
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "second", false, ERR_IO_PENDING, L"bingo", 1000);
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "third", true, OK, L"rocko", 1);
+  client->RunTest();
+  client->RunMessageLoopUntilComplete();
+  ASSERT_EQ(OK, client->result_);
+  ASSERT_EQ(L"rocko", client->pac_text_);
+}
+
+TEST(WindowsDhcpProxyScriptFetcher,
+     NormalCaseURLConfiguredMultipleAdaptersWithTimeout) {
+  FetcherClient client;
+  TestNormalCaseURLConfiguredMultipleAdaptersWithTimeout(&client);
+}
+
+void TestFailureCaseURLConfiguredMultipleAdaptersWithTimeout(
+    FetcherClient* client) {
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "most_preferred", true, ERR_PAC_NOT_IN_DHCP, L"", 1);
+  // This will time out.
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "second", false, ERR_IO_PENDING, L"bingo", 1000);
+  // This is the first non-ERR_PAC_NOT_IN_DHCP error and as such
+  // should be chosen.
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "third", true, ERR_PAC_STATUS_NOT_OK, L"", 1);
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "fourth", true, ERR_NOT_IMPLEMENTED, L"", 1);
+  client->RunTest();
+  client->RunMessageLoopUntilComplete();
+  ASSERT_EQ(ERR_PAC_STATUS_NOT_OK, client->result_);
+  ASSERT_EQ(L"", client->pac_text_);
+}
+
+TEST(WindowsDhcpProxyScriptFetcher,
+     FailureCaseURLConfiguredMultipleAdaptersWithTimeout) {
+  FetcherClient client;
+  TestFailureCaseURLConfiguredMultipleAdaptersWithTimeout(&client);
+}
+
+void TestFailureCaseNoURLConfigured(FetcherClient* client) {
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "most_preferred", true, ERR_PAC_NOT_IN_DHCP, L"", 1);
+  // This will time out.
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "second", false, ERR_IO_PENDING, L"bingo", 1000);
+  // This is the first non-ERR_PAC_NOT_IN_DHCP error and as such
+  // should be chosen.
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "third", true, ERR_PAC_NOT_IN_DHCP, L"", 1);
+  client->RunTest();
+  client->RunMessageLoopUntilComplete();
+  ASSERT_EQ(ERR_PAC_NOT_IN_DHCP, client->result_);
+  ASSERT_EQ(L"", client->pac_text_);
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, FailureCaseNoURLConfigured) {
+  FetcherClient client;
+  TestFailureCaseNoURLConfigured(&client);
+}
+
+void TestFailureCaseNoDhcpAdapters(FetcherClient* client) {
+  client->RunImmediateReturnTest();
+  // In case there are any pending messages that get us in a bad state
+  // (there shouldn't be).
+  MessageLoop::current()->RunAllPending();
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, FailureCaseNoDhcpAdapters) {
+  FetcherClient client;
+  TestFailureCaseNoDhcpAdapters(&client);
+}
+
+void TestShortCircuitLessPreferredAdapters(FetcherClient* client) {

[eroman, 2011/05/17 04:39:39]

I did not have time to review this file thoroughly, hopefully I can give it a
more thorough pass later.

[Jói, 2011/05/17 15:38:35]

OK, thanks Eric.

+  // Here we have a bunch of adapters; the first reports no PAC in DHCP,
+  // the second responds quickly with a PAC file, the rest take a long
+  // time.  Verify that we complete quickly and do not wait for the slow
+  // adapters, i.e. we finish before timeout.
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "1", true, ERR_PAC_NOT_IN_DHCP, L"", 1);
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "2", true, OK, L"bingo", 1);
+  client->fetcher_.ConfigureAndPushBackAdapter(
+      "3", true, OK, L"wrongo", 1000);
+
+  PerfTimer timer;
+  client->RunTest();
+  client->RunMessageLoopUntilComplete();
+  // Assert that the time passed is just less than the wait timer
+  // timeout (which we have mocked out above to be 25 ms), to avoid
+  // flakiness but still get a strong signal that it was the shortcut
+  // mechanism (in OnFetcherDone) that kicked in.
+  ASSERT_GT(TimeDelta::FromMilliseconds(23), timer.Elapsed());
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, ShortCircuitLessPreferredAdapters) {
+  FetcherClient client;
+  TestShortCircuitLessPreferredAdapters(&client);
+}
+
+TEST(WindowsDhcpProxyScriptFetcher, ReuseFetcher) {
+  FetcherClient client;
+
+  // The ProxyScriptFetcher interface stipulates that only a single
+  // |Fetch()| may be in flight at once, but allows reuse, so test
+  // that the state transitions correctly from done to start in all
+  // cases we're testing.
+
+  typedef void (*FetcherClientTestFunction)(FetcherClient*);
+  typedef std::vector<FetcherClientTestFunction> TestVector;
+  TestVector test_functions;
+  test_functions.push_back(TestNormalCaseURLConfiguredOneAdapter);
+  test_functions.push_back(TestNormalCaseURLConfiguredMultipleAdapters);
+  test_functions.push_back(
+      TestNormalCaseURLConfiguredMultipleAdaptersWithTimeout);
+  test_functions.push_back(
+      TestFailureCaseURLConfiguredMultipleAdaptersWithTimeout);
+  test_functions.push_back(TestFailureCaseNoURLConfigured);
+  test_functions.push_back(TestFailureCaseNoDhcpAdapters);
+  test_functions.push_back(TestShortCircuitLessPreferredAdapters);
+
+  std::random_shuffle(test_functions.begin(),
+                      test_functions.end(),
+                      base::RandGenerator);
+  for (TestVector::iterator it = test_functions.begin();
+       it != test_functions.end();
+       ++it) {
+    (*it)(&client);
+    client.ResetTestState();
+  }
+
+  // Re-do the first test to make sure the last test that was run did
+  // not leave things in a bad state.
+  (*test_functions.begin())(&client);
+}
+
+}  // namespace
+
+}  // namespace net