Get rid of the ChildProcessInfo class. It was carrying unnecessary data, and the fact that some p...

content/common/child_process_host.cc

 // Copyright (c) 2011 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 "content/common/child_process_host.h"
 
+#include <limits>
+
+#include "base/atomicops.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
+#include "base/rand_util.h"
+#include "base/stringprintf.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
-#include "content/common/child_process_info.h"
 #include "content/common/child_process_messages.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
 #include "ipc/ipc_logging.h"
 
 #if defined(OS_LINUX)
 #include "base/linux_util.h"
 #elif defined(OS_WIN)
 #include "content/common/font_cache_dispatcher_win.h"
 #endif  // OS_LINUX
@@ skipping 109 matching lines @@
 #endif
 
   return child_path;
 }
 
 void ChildProcessHost::ForceShutdown() {
   Send(new ChildProcessMsg_Shutdown());
 }
 
 bool ChildProcessHost::CreateChannel() {
-  channel_id_ = ChildProcessInfo::GenerateRandomChannelID(this);
+  channel_id_ = GenerateRandomChannelID(this);
   channel_.reset(new IPC::Channel(
       channel_id_, IPC::Channel::MODE_SERVER, &listener_));
   if (!channel_->Connect())
     return false;
 
   for (size_t i = 0; i < filters_.size(); ++i)
     filters_[i]->OnFilterAdded(channel_.get());
 
   // Make sure these messages get sent first.
 #if defined(IPC_MESSAGE_LOG_ENABLED)
@@ skipping 31 matching lines @@
       base::SharedMemoryHandle* shared_memory_handle) {
   base::SharedMemory shared_buf;
   if (!shared_buf.CreateAndMapAnonymous(buffer_size)) {
     *shared_memory_handle = base::SharedMemory::NULLHandle();
     NOTREACHED() << "Cannot map shared memory buffer";
     return;
   }
   shared_buf.GiveToProcess(child_process_handle, shared_memory_handle);
 }
 
+std::string ChildProcessHost::GenerateRandomChannelID(void* instance) {
+  // Note: the string must start with the current process id, this is how
+  // child processes determine the pid of the parent.
+  // Build the channel ID.  This is composed of a unique identifier for the
+  // parent browser process, an identifier for the child instance, and a random
+  // component. We use a random component so that a hacked child process can't
+  // cause denial of service by causing future named pipe creation to fail.
+  return base::StringPrintf("%d.%p.%d",
+                            base::GetCurrentProcId(), instance,
+                            base::RandInt(0, std::numeric_limits<int>::max()));
+}
+
+int ChildProcessHost::GenerateChildProcessUniqueId() {
+  // This function must be threadsafe.
+  static base::subtle::Atomic32 last_unique_child_id = 0;
+  return base::subtle::NoBarrier_AtomicIncrement(&last_unique_child_id, 1);
+}
+
+
 void ChildProcessHost::OnChildDied() {
   delete this;
 }
 
 void ChildProcessHost::OnChildDisconnected() {
   OnChildDied();
 }
 
 void ChildProcessHost::ShutdownStarted() {
 }
@@ skipping 89 matching lines @@
     uint32 buffer_size,
     base::SharedMemoryHandle* handle) {
   ChildProcessHost::OnAllocateSharedMemory(
       buffer_size, peer_handle_, handle);
 }
 
 void ChildProcessHost::ListenerHook::OnShutdownRequest() {
   if (host_->CanShutdown())
     host_->Send(new ChildProcessMsg_Shutdown());
 }