| // Copyright (c) 2012 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 "ipc/ipc_channel.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <limits> |
| |
| #include "base/atomic_sequence_num.h" |
| #include "base/rand_util.h" |
| #include "base/strings/stringprintf.h" |
| #include "build/build_config.h" |
| |
| namespace { |
| |
| // Global atomic used to guarantee channel IDs are unique. |
| base::AtomicSequenceNumber g_last_id; |
| |
| } // namespace |
| |
| namespace IPC { |
| |
| // static |
| constexpr size_t Channel::kMaximumMessageSize; |
| |
| // static |
| std::string Channel::GenerateUniqueRandomChannelID() { |
| // Note: the string must start with the current process id, this is how |
| // some child processes determine the pid of the parent. |
| // |
| // This is composed of a unique incremental identifier, the process ID of |
| // the creator, an identifier for the child instance, and a strong random |
| // component. The strong random component prevents other processes from |
| // hijacking or squatting on predictable channel names. |
| int process_id = base::GetCurrentProcId(); |
| return base::StringPrintf("%d.%u.%d", |
| process_id, |
| g_last_id.GetNext(), |
| base::RandInt(0, std::numeric_limits<int32_t>::max())); |
| } |
| |
| } // namespace IPC |