| // Copyright 2014 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. |
| |
| #ifndef SANDBOX_LINUX_SYSCALL_BROKER_BROKER_COMMON_H_ |
| #define SANDBOX_LINUX_SYSCALL_BROKER_BROKER_COMMON_H_ |
| |
| #include <fcntl.h> |
| #include <stddef.h> |
| |
| namespace sandbox { |
| |
| namespace syscall_broker { |
| |
| const size_t kMaxMessageLength = 4096; |
| |
| // Some flags are local to the current process and cannot be sent over a Unix |
| // socket. They need special treatment from the client. |
| // O_CLOEXEC is tricky because in theory another thread could call execve() |
| // before special treatment is made on the client, so a client needs to call |
| // recvmsg(2) with MSG_CMSG_CLOEXEC. |
| // To make things worse, there are two CLOEXEC related flags, FD_CLOEXEC (see |
| // F_GETFD in fcntl(2)) and O_CLOEXEC (see F_GETFL in fcntl(2)). O_CLOEXEC |
| // doesn't affect the semantics on execve(), it's merely a note that the |
| // descriptor was originally opened with O_CLOEXEC as a flag. And it is sent |
| // over unix sockets just fine, so a receiver that would (incorrectly) look at |
| // O_CLOEXEC instead of FD_CLOEXEC may be tricked in thinking that the file |
| // descriptor will or won't be closed on execve(). |
| const int kCurrentProcessOpenFlagsMask = O_CLOEXEC; |
| |
| enum IPCCommand { |
| COMMAND_INVALID = 0, |
| COMMAND_OPEN, |
| COMMAND_ACCESS, |
| }; |
| |
| } // namespace syscall_broker |
| |
| } // namespace sandbox |
| |
| #endif // SANDBOX_LINUX_SYSCALL_BROKER_BROKER_COMMON_H_ |