util/linux/exception_handler_protocol.h

// 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.

#ifndef CRASHPAD_UTIL_LINUX_EXCEPTION_HANDLER_PROTOCOL_H_
#define CRASHPAD_UTIL_LINUX_EXCEPTION_HANDLER_PROTOCOL_H_

#include <errno.h>
#include <stdint.h>
#include <sys/types.h>

#include "util/file/file_io.h"
#include "util/misc/address_types.h"

namespace crashpad {

#pragma pack(push, 1)

//! \brief The type used for error reporting.
using Errno = int32_t;
static_assert(sizeof(Errno) >= sizeof(errno), "Errno type is too small");

//! \brief A boolean status suitable for communication between processes.
enum Bool : char { kBoolFalse, kBoolTrue };

//! \brief Information about a client registered with an ExceptionHandlerServer.
struct ClientInformation {
  //! \brief Constructs this object.
  ClientInformation();

  //! \brief The address in the client's address space of an
  //!     ExceptionInformation struct.
  VMAddress exception_information_address;

  //! \brief The address in the client's address space of a
  //!     SanitizationInformation struct, or 0 if there is no such struct.
  VMAddress sanitization_information_address;
};

//! \brief The message passed from client to server.
struct ClientToServerMessage {
  static constexpr int32_t kVersion = 1;

  //! \brief Constructs this object.
  ClientToServerMessage();

  //! \brief Indicates what message version is being used.
  int32_t version;

  enum Type : uint32_t {
    //! \brief Used to request a crash dump for the sending client.
    kCrashDumpRequest
  } type;

  union {
    //! \brief Valid for type == kCrashDumpRequest
    ClientInformation client_info;
  };
};

//! \brief The message passed from server to client.
struct ServerToClientMessage {
  enum Type : uint32_t {
    //! \brief Indicates that the client should fork a PtraceBroker process.
    kTypeForkBroker,

    //! \brief Inidicates that the client should set allow the handler to trace
    //!     it using PR_SET_PTRACER.
    kTypeSetPtracer,

    //! \brief Indicates that the handler has completed a requested crash dump.
    kTypeCrashDumpComplete,

    //! \brief Indicicates that the handler was unable to produce a crash dump.
    kTypeCrashDumpFailed
  } type;

  //! \brief The handler's process ID. Valid for kTypeSetPtracer.
  pid_t pid;
};

#pragma pack(pop)

}  // namespace crashpad

#endif  // CRASHPAD_UTIL_LINUX_EXCEPTION_HANDLER_PROTOCOL_H_