// Copyright 2017 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 "handler/fuchsia/crash_report_exception_handler.h"

#include <lib/zx/thread.h>
#include <zircon/syscalls/exception.h>

#include "base/fuchsia/fuchsia_logging.h"
#include "client/settings.h"
#include "minidump/minidump_file_writer.h"
#include "minidump/minidump_user_extension_stream_data_source.h"
#include "snapshot/fuchsia/process_snapshot_fuchsia.h"
#include "util/fuchsia/koid_utilities.h"

namespace crashpad {

namespace {

class ScopedThreadResumeAfterException {
 public:
  ScopedThreadResumeAfterException(const zx::thread& thread,
                                   const zx::unowned_port& exception_port)
      : thread_(thread), exception_port_(exception_port) {}
  ~ScopedThreadResumeAfterException() {
    DCHECK(thread_->is_valid());
    // Resuming with ZX_RESUME_TRY_NEXT chains to the next handler. In normal
    // operation, there won't be another beyond this one, which will result in
    // the kernel terminating the process.
    zx_status_t status =
        thread_->resume_from_exception(*exception_port_, ZX_RESUME_TRY_NEXT);
    ZX_LOG_IF(ERROR, status != ZX_OK, status)
        << "zx_task_resume_from_exception";
  }

 private:
  zx::unowned_thread thread_;
  const zx::unowned_port& exception_port_;

  DISALLOW_COPY_AND_ASSIGN(ScopedThreadResumeAfterException);
};

}  // namespace

CrashReportExceptionHandler::CrashReportExceptionHandler(
    CrashReportDatabase* database,
    CrashReportUploadThread* upload_thread,
    const std::map<std::string, std::string>* process_annotations,
    const std::map<std::string, base::FilePath>* process_attachments,
    const UserStreamDataSources* user_stream_data_sources)
    : database_(database),
      upload_thread_(upload_thread),
      process_annotations_(process_annotations),
      process_attachments_(process_attachments),
      user_stream_data_sources_(user_stream_data_sources) {}

CrashReportExceptionHandler::~CrashReportExceptionHandler() {}

bool CrashReportExceptionHandler::HandleException(
    uint64_t process_id,
    uint64_t thread_id,
    const zx::unowned_port& exception_port,
    UUID* local_report_id) {
  // TODO(scottmg): This function needs to be instrumented with metrics calls,
  // https://crashpad.chromium.org/bug/230.

  zx::process process(GetProcessFromKoid(process_id));
  if (!process.is_valid()) {
    // There's no way to resume the thread if the process retrieval fails.
    // Assume that the process has been already killed, and bail.
    return false;
  }

  zx::thread thread(GetThreadHandleByKoid(process, thread_id));
  if (!thread.is_valid()) {
    return false;
  }

  return HandleExceptionHandles(
      process, thread, exception_port, local_report_id);
}

bool CrashReportExceptionHandler::HandleExceptionHandles(
    const zx::process& process,
    const zx::thread& thread,
    const zx::unowned_port& exception_port,
    UUID* local_report_id) {
  // Now that the thread has been successfully retrieved, it is possible to
  // correctly call zx_task_resume_from_exception() to continue exception
  // processing, even if something else during this function fails.
  ScopedThreadResumeAfterException resume(thread, exception_port);

  ProcessSnapshotFuchsia process_snapshot;
  if (!process_snapshot.Initialize(process)) {
    return false;
  }

  CrashpadInfoClientOptions client_options;
  process_snapshot.GetCrashpadOptions(&client_options);

  if (client_options.crashpad_handler_behavior == TriState::kDisabled) {
    return true;
  }

  zx_exception_report_t report;
  zx_status_t status = thread.get_info(ZX_INFO_THREAD_EXCEPTION_REPORT,
                                       &report,
                                       sizeof(report),
                                       nullptr,
                                       nullptr);
  if (status != ZX_OK) {
    ZX_LOG(ERROR, status)
        << "zx_object_get_info ZX_INFO_THREAD_EXCEPTION_REPORT";
    return false;
  }

  zx_koid_t thread_id = GetKoidForHandle(thread);
  if (!process_snapshot.InitializeException(thread_id, report)) {
    return false;
  }

  UUID client_id;
  Settings* const settings = database_->GetSettings();
  if (settings) {
    // If GetSettings() or GetClientID() fails, something else will log a
    // message and client_id will be left at its default value, all zeroes,
    // which is appropriate.
    settings->GetClientID(&client_id);
  }

  process_snapshot.SetClientID(client_id);
  process_snapshot.SetAnnotationsSimpleMap(*process_annotations_);

  std::unique_ptr<CrashReportDatabase::NewReport> new_report;
  CrashReportDatabase::OperationStatus database_status =
      database_->PrepareNewCrashReport(&new_report);
  if (database_status != CrashReportDatabase::kNoError) {
    return false;
  }

  process_snapshot.SetReportID(new_report->ReportID());

  MinidumpFileWriter minidump;
  minidump.InitializeFromSnapshot(&process_snapshot);
  AddUserExtensionStreams(
      user_stream_data_sources_, &process_snapshot, &minidump);

  if (!minidump.WriteEverything(new_report->Writer())) {
    return false;
  }

  if (process_attachments_) {
    // Note that attachments are read at this point each time rather than once
    // so that if the contents of the file has changed it will be re-read for
    // each upload (e.g. in the case of a log file).
    for (const auto& it : *process_attachments_) {
      FileWriter* writer = new_report->AddAttachment(it.first);
      if (writer) {
        std::string contents;
        if (!LoggingReadEntireFile(it.second, &contents)) {
          // Not being able to read the file isn't considered fatal, and
          // should not prevent the report from being processed.
          continue;
        }
        writer->Write(contents.data(), contents.size());
      }
    }
  }

  UUID uuid;
  database_status =
      database_->FinishedWritingCrashReport(std::move(new_report), &uuid);
  if (database_status != CrashReportDatabase::kNoError) {
    return false;
  }
  if (local_report_id != nullptr) {
    *local_report_id = uuid;
  }

  if (upload_thread_) {
    upload_thread_->ReportPending(uuid);
  }

  return true;
}

}  // namespace crashpad