Implement more of CrashpadClient on Windows

client/crashpad_client_win.cc

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "client/crashpad_client.h"
 
 #include <windows.h>
 
 #include "base/logging.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "client/crashpad_info.h"
+#include "client/registration_protocol_win.h"
+#include "util/file/file_io.h"
+#include "util/win/scoped_handle.h"
 
 namespace {
 // Time to wait for the handler to create a dump. This is tricky to figure out.
 const DWORD kMillisecondsUntilTerminate = 5000;
 
 // This is the exit code that the process will return to the system once the
-// crash has been handled by Crashpad. We don't want to clash with the 
+// crash has been handled by Crashpad. We don't want to clash with the
 // application-defined exit codes but we don't know them so we use one that is
 // unlikely to be used.
 const UINT kCrashExitCode = 0xffff7001;
 
 // These two handles to events are leaked.
 HANDLE g_signal_exception = nullptr;
 HANDLE g_wait_termination = nullptr;
 
 LONG WINAPI UnhandledExceptionHandler(EXCEPTION_POINTERS* exception_pointers) {
-  // TODO (cpu): Here write |exception_pointers| to g_crashpad_info.
+  crashpad::CrashpadInfo::GetCrashpadInfo()->set_exception_pointers(

[Mark Mentovai, 2015/08/13 13:38:53]

Is there a guarantee that this will only be called on one thread at a time?

[scottmg, 2015/08/13 22:41:45]

Good call. I went back and forth on this for a while, but I think what's here
now makes sense for multiple simultaneous crashes.

+      reinterpret_cast<crashpad::WinVMAddress>(exception_pointers));
   DWORD rv = SignalObjectAndWait(g_signal_exception,
                                  g_wait_termination,
                                  kMillisecondsUntilTerminate,
                                  FALSE);
   if (rv != WAIT_OBJECT_0) {
     // Something went wrong. It is likely that a dump has not been created.
     if (rv == WAIT_TIMEOUT) {
       LOG(WARNING) << "SignalObjectAndWait timed out";
     } else {
       PLOG(WARNING) << "SignalObjectAndWait error";
     }
   }
   // We don't want to generate more exceptions, so we take the fast route.
   TerminateProcess(GetCurrentProcess(), kCrashExitCode);
   return 0L;
 }
 
+// Returns a pipe handle connected to the RegistrationServer.
+crashpad::ScopedFileHANDLE Connect(const base::string16& pipe_name) {
+  crashpad::ScopedFileHANDLE pipe;
+  const int kMaxRetries = 5;

[Mark Mentovai, 2015/08/13 13:38:53]

Since the first try doesn’t count as a REtry, name these const int kMaxTries and
int try?

[scottmg, 2015/08/13 22:41:45]

Done. ("try" not so good in C++ :)

+  for (int retries = 0; !pipe.is_valid() && retries < kMaxRetries; ++retries) {
+    if (!WaitNamedPipe(pipe_name.c_str(), NMPWAIT_WAIT_FOREVER))
+      break;
+    pipe.reset(CreateFile(pipe_name.c_str(),
+                          GENERIC_READ | GENERIC_WRITE,
+                          0,
+                          NULL,

[Mark Mentovai, 2015/08/13 13:38:53]

nullptr, line 74 too.

[scottmg, 2015/08/13 22:41:45]

Done.

+                          OPEN_EXISTING,
+                          SECURITY_SQOS_PRESENT | SECURITY_ANONYMOUS,
+                          NULL));
+    if (pipe.is_valid()) {
+      DWORD mode = PIPE_READMODE_MESSAGE;
+      if (!SetNamedPipeHandleState(pipe.get(),
+                                   &mode,
+                                   nullptr,  // Don't set maximum bytes.
+                                   nullptr)) {  // Don't set maximum time.
+        pipe.reset();
+      }
+    }
+  }
+  if (!pipe.is_valid()) {
+    LOG(ERROR) << "Connect";

[Mark Mentovai, 2015/08/13 13:38:53]

There are three things that can fail above. Is it useful to know which one
failed and to get the reason for failure included with PLOG?

[scottmg, 2015/08/13 22:41:45]

Done.

+    return crashpad::ScopedFileHANDLE();
+  }
+  return pipe.Pass();
+}
+
 }  // namespace
 
 namespace crashpad {
 
 CrashpadClient::CrashpadClient() {
 }
 
 CrashpadClient::~CrashpadClient() {
 }
 
 bool CrashpadClient::StartHandler(
     const base::FilePath& handler,
     const base::FilePath& database,
     const std::string& url,
     const std::map<std::string, std::string>& annotations,
     const std::vector<std::string>& arguments) {
-  // TODO(cpu): Provide a reference implementation.
   return false;
 }
 
 bool CrashpadClient::SetHandler(const std::string& ipc_port) {
-  // TODO (cpu): Contact the handler and obtain g_signal_exception and
-  // g_wait_termination.
-  return false;
+  RegistrationRequest request = {0};
+  request.client_process_id = GetCurrentProcessId();
+  request.crashpad_info_address =
+      reinterpret_cast<WinVMAddress>(CrashpadInfo::GetCrashpadInfo());
+
+  RegistrationResponse response = {0};
+
+  ScopedFileHANDLE pipe = Connect(base::UTF8ToUTF16(ipc_port));
+  if (!pipe.is_valid())
+    return false;
+  bool result = LoggingWriteFile(pipe.get(), &request, sizeof(request)) &&
+                LoggingReadFile(pipe.get(), &response, sizeof(response));
+  if (!result)
+    return result;
+
+  // The server returns these already duplicated to be valid in this process.
+  g_signal_exception = reinterpret_cast<HANDLE>(response.request_report_event);
+  g_wait_termination =
+      reinterpret_cast<HANDLE>(response.report_complete_event);
+  return true;
 }
 
 bool CrashpadClient::UseHandler() {
   if (!g_signal_exception)
     return false;
   if (!g_wait_termination)
     return false;
   // In theory we could store the previous handler but it is not clear what
   // use we have for it.
   SetUnhandledExceptionFilter(&UnhandledExceptionHandler);
   return true;
 }
 
 }  // namespace crashpad