Make IPC channels track their peer process ID

ipc/ipc_channel_posix.h

 // 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.
 
 #ifndef IPC_IPC_CHANNEL_POSIX_H_
 #define IPC_IPC_CHANNEL_POSIX_H_
 #pragma once
 
 #include "ipc/ipc_channel.h"
 
 #include <sys/socket.h>  // for CMSG macros
 
 #include <queue>
 #include <string>
 #include <vector>
 
 #include "base/message_loop.h"
+#include "base/process.h"
 #include "ipc/file_descriptor_set_posix.h"
 #include "ipc/ipc_channel_reader.h"
 
 #if !defined(OS_MACOSX)
 // On Linux, the seccomp sandbox makes it very expensive to call
 // recvmsg() and sendmsg(). The restriction on calling read() and write(), which
 // are cheap, is that we can't pass file descriptors over them.
 //
 // As we cannot anticipate when the sender will provide us with file
 // descriptors, we have to make the decision about whether we call read() or
@@ skipping 30 matching lines @@
   bool Connect();
   void Close();
   bool Send(Message* message);
   int GetClientFileDescriptor();
   int TakeClientFileDescriptor();
   void CloseClientFileDescriptor();
   bool AcceptsConnections() const;
   bool HasAcceptedConnection() const;
   bool GetClientEuid(uid_t* client_euid) const;
   void ResetToAcceptingConnectionState();
+  base::ProcessId peer_pid() const { return peer_pid_; }
   static bool IsNamedServerInitialized(const std::string& channel_id);
 #if defined(OS_LINUX)
   static void SetGlobalPid(int pid);
 #endif  // OS_LINUX
 
  private:
   bool CreatePipe(const IPC::ChannelHandle& channel_handle);
 
   bool ProcessOutgoingMessages();
 
@@ skipping 28 matching lines @@
   // Closes all handles in the input_fds_ list and clears the list. This is
   // used to clean up handles in error conditions to avoid leaking the handles.
   void ClearInputFDs();
 
   // MessageLoopForIO::Watcher implementation.
   virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
   virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
 
   Mode mode_;
 
+  base::ProcessId peer_pid_;
+
   // After accepting one client connection on our server socket we want to
   // stop listening.
   MessageLoopForIO::FileDescriptorWatcher server_listen_connection_watcher_;
   MessageLoopForIO::FileDescriptorWatcher read_watcher_;
   MessageLoopForIO::FileDescriptorWatcher write_watcher_;
 
   // Indicates whether we're currently blocked waiting for a write to complete.
   bool is_blocked_on_write_;
   bool waiting_connect_;
 
@@ skipping 64 matching lines @@
 
 // The maximum length of the name of a pipe for MODE_NAMED_SERVER or
 // MODE_NAMED_CLIENT if you want to pass in your own socket.
 // The standard size on linux is 108, mac is 104. To maintain consistency
 // across platforms we standardize on the smaller value.
 static const size_t kMaxPipeNameLength = 104;
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_POSIX_H_