[Mac] Remove base::LaunchSynchronize and rewrite content::MachBroker.

content/browser/mach_broker_mac.mm

Index: content/browser/mach_broker_mac.mm
diff --git a/content/browser/mach_broker_mac.cc b/content/browser/mach_broker_mac.mm
similarity index 48%
rename from content/browser/mach_broker_mac.cc
rename to content/browser/mach_broker_mac.mm
index b25563586884c818f2dcbc0bd76d736d99a0325f..d765cf5d9e2e40705b1a059710e35fdd9482691f 100644
--- a/content/browser/mach_broker_mac.cc
+++ b/content/browser/mach_broker_mac.mm
@@ -4,11 +4,14 @@
 
 #include "content/browser/mach_broker_mac.h"
 
+#include <bsm/libbsm.h>
+
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
+#include "base/mac/scoped_mach_port.h"
 #include "base/mach_ipc_mac.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
@@ -24,83 +27,163 @@
 namespace content {
 
 namespace {
+
 // Prints a string representation of a Mach error code.
 std::string MachErrorCode(kern_return_t err) {
   return base::StringPrintf("0x%x %s", err, mach_error_string(err));
 }
+
+// Mach message structure used in the child as a sending message.
+struct MachBroker_ChildSendMsg {
+  mach_msg_header_t header;
+  mach_msg_body_t body;
+  mach_msg_port_descriptor_t child_task_port;
+};
+
+// Complement to the ChildSendMsg, this is used in the parent for receiving
+// a message. Contains a message trailer with audit information.
+struct MachBroker_ParentRecvMsg : public MachBroker_ChildSendMsg {
+  mach_msg_audit_trailer_t trailer;
+};
+
 }  // namespace
 
 class MachListenerThreadDelegate : public base::PlatformThread::Delegate {
  public:
-  MachListenerThreadDelegate(MachBroker* broker) : broker_(broker) {
+  explicit MachListenerThreadDelegate(MachBroker* broker)
+      : broker_(broker),
+        server_port_(MACH_PORT_NULL) {
     DCHECK(broker_);
-    std::string port_name = MachBroker::GetMachPortName();
+  }
+
+  bool Init() {
+    DCHECK(server_port_ == MACH_PORT_NULL);
+
+    mach_port_t port;
+    kern_return_t kr = mach_port_allocate(mach_task_self(),
+                                          MACH_PORT_RIGHT_RECEIVE,
+                                          &port);
+    if (kr != KERN_SUCCESS) {
+      LOG(ERROR) << "Failed to allocate MachBroker server port: "
+                 << MachErrorCode(kr);
+      return false;
+    }
+
+    // Allocate a send right for the server port.
+    kr = mach_port_insert_right(
+        mach_task_self(), port, port, MACH_MSG_TYPE_MAKE_SEND);
+    if (kr != KERN_SUCCESS) {
+      LOG(ERROR) << "Failed to insert send right for MachBroker server port: "
+                 << MachErrorCode(kr);
+      return false;
+    }
 
-    // Create the receive port in the constructor, not in ThreadMain().  It is
-    // important to create and register the receive port before starting the
-    // thread so that child processes will always have someone who's listening.
-    receive_port_.reset(new base::ReceivePort(port_name.c_str()));
+    server_port_.reset(port);
+
+    // Register the port with the bootstrap server. Because bootstrap_register
+    // is deprecated, this has to be wraped in an ObjC interface.
+    NSPort* ns_port = [NSMachPort portWithMachPort:port
+                                           options:NSMachPortDeallocateNone];
+    NSString* name = base::SysUTF8ToNSString(broker_->GetMachPortName());
+    return [[NSMachBootstrapServer sharedInstance] registerPort:ns_port
+                                                           name:name];
   }
 
   // Implement |PlatformThread::Delegate|.
   virtual void ThreadMain() OVERRIDE {
-    base::MachReceiveMessage message;
-    kern_return_t err;
-    while ((err = receive_port_->WaitForMessage(&message,
-                                                MACH_MSG_TIMEOUT_NONE)) ==
-           KERN_SUCCESS) {
-      // 0 was the secret message id.  Reject any messages that don't have it.
-      if (message.GetMessageID() != 0) {
-        LOG(ERROR) << "Received message with incorrect id: "
-                   << message.GetMessageID();
-        continue;
-      }
-
-      const task_t child_task = message.GetTranslatedPort(0);
-      if (child_task == MACH_PORT_NULL) {
-        LOG(ERROR) << "parent GetTranslatedPort(0) failed.";
-        continue;
+    MachBroker_ParentRecvMsg msg;
+    bzero(&msg, sizeof(msg));
+    msg.header.msgh_size = sizeof(msg);
+    msg.header.msgh_local_port = server_port_.get();
+
+    kern_return_t kr;
+    do {
+      // Use the kernel audit information to make sure this message is from
+      // a task that this process spawned. The kernel audit token contains the
+      // unspoofable pid of the task that sent the message.
+      mach_msg_option_t options = MACH_RCV_MSG |
+          MACH_RCV_TRAILER_TYPE(MACH_RCV_TRAILER_AUDIT) |
+          MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AUDIT);
+
+      kr = mach_msg(&msg.header, options, 0, sizeof(msg), server_port_,
+          MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+      if (kr == KERN_SUCCESS) {
+        // TODO(rsesek): In the 10.7 SDK, there's audit_token_to_pid().
+        pid_t child_pid;
+        audit_token_to_au32(msg.trailer.msgh_audit,
+            NULL, NULL, NULL, NULL, NULL, &child_pid, NULL, NULL);
+
+        mach_port_t child_task_port = msg.child_task_port.name;
+
+        // Take the lock and update the broker information.
+        base::AutoLock lock(broker_->GetLock());
+        broker_->FinalizePid(child_pid, child_task_port);
       }
+    } while (kr == KERN_SUCCESS);
 
-      // It is possible for the child process to die after the call to
-      // |pid_for_task()| but before the call to |FinalizePid()|.  To prevent
-      // leaking MachBroker map entries in this case, lock around both these
-      // calls.  If the child dies, the death notification will be processed
-      // after the call to FinalizePid(), ensuring proper cleanup.
-      base::AutoLock lock(broker_->GetLock());
-
-      int pid;
-      err = pid_for_task(child_task, &pid);
-      if (err == KERN_SUCCESS) {
-        broker_->FinalizePid(pid,
-                             MachBroker::MachInfo().SetTask(child_task));
-      } else {
-        LOG(ERROR) << "Error getting pid for task " << child_task
-                   << ": " << MachErrorCode(err);
-      }
-    }
-
-    LOG(ERROR) << "Mach listener thread exiting; "
-               << "parent WaitForMessage() likely failed: "
-               << MachErrorCode(err);
+    LOG(ERROR) << "MachBroker thread exiting; mach_msg() likely failed: "
+               << MachErrorCode(kr);
   }
 
  private:
-  // The Mach port to listen on.  Created on thread startup.
-  scoped_ptr<base::ReceivePort> receive_port_;
-
   // The MachBroker to use when new child task rights are received.  Can be
   // NULL.
   MachBroker* broker_;  // weak
 
+  base::mac::ScopedMachPort server_port_;
+
   DISALLOW_COPY_AND_ASSIGN(MachListenerThreadDelegate);
 };
 
-// Returns the global MachBroker.
+bool MachBroker::ChildSendTaskPortToParent() {
+  // Look up the named MachBroker port that's been registered with the
+  // bootstrap server.
+  mach_port_t bootstrap_port;
+  kern_return_t kr = task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
+  if (kr != KERN_SUCCESS) {
+    LOG(ERROR) << "Failed to look up bootstrap port: " << MachErrorCode(kr);
+    return false;
+  }
+
+  mach_port_t parent_port;
+  kr = bootstrap_look_up(bootstrap_port,
+      const_cast<char*>(GetMachPortName().c_str()), &parent_port);
+  if (kr != KERN_SUCCESS) {
+    LOG(ERROR) << "Failed to look up named parent port: " << MachErrorCode(kr);
+    return false;
+  }
+
+  // Create the check in message. This will copy a send right on this process'
+  // (the child's) task port and send it to the parent.
+  MachBroker_ChildSendMsg msg;
+  bzero(&msg, sizeof(msg));
+  msg.header.msgh_bits = MACH_MSGH_BITS_REMOTE(MACH_MSG_TYPE_COPY_SEND) |
+                         MACH_MSGH_BITS_COMPLEX;
+  msg.header.msgh_remote_port = parent_port;
+  msg.header.msgh_size = sizeof(msg);
+  msg.body.msgh_descriptor_count = 1;
+  msg.child_task_port.name = mach_task_self();
+  msg.child_task_port.disposition = MACH_MSG_TYPE_PORT_SEND;
+  msg.child_task_port.type = MACH_MSG_PORT_DESCRIPTOR;
+
+  kr = mach_msg(&msg.header, MACH_SEND_MSG | MACH_SEND_TIMEOUT, sizeof(msg),
+      0, MACH_PORT_NULL, 100 /*milliseconds*/, MACH_PORT_NULL);
+  if (kr != KERN_SUCCESS) {
+    LOG(ERROR) << "Failed to send task port to parent: " << MachErrorCode(kr);
+    return false;
+  }
+
+  return true;
+}
+
 MachBroker* MachBroker::GetInstance() {
   return Singleton<MachBroker, LeakySingletonTraits<MachBroker> >::get();
 }
 
+base::Lock& MachBroker::GetLock() {
+  return lock_;
+}
+
 void MachBroker::EnsureRunning() {
   lock_.AssertAcquired();
 
@@ -112,64 +195,28 @@ void MachBroker::EnsureRunning() {
         base::Bind(&MachBroker::RegisterNotifications, base::Unretained(this)));
 
     // Intentional leak.  This thread is never joined or reaped.
-    base::PlatformThread::CreateNonJoinable(
-        0, new MachListenerThreadDelegate(this));
+    MachListenerThreadDelegate* thread = new MachListenerThreadDelegate(this);
+    if (thread->Init()) {
+      base::PlatformThread::CreateNonJoinable(0, thread);
+    } else {
+      LOG(ERROR) << "Failed to initialize the MachListenerThreadDelegate";
+    }
   }
 }
 
-// Adds a placeholder to the map for the given pid with MACH_PORT_NULL.
 void MachBroker::AddPlaceholderForPid(base::ProcessHandle pid) {
   lock_.AssertAcquired();
 
-  MachInfo mach_info;
   DCHECK_EQ(0u, mach_map_.count(pid));
-  mach_map_[pid] = mach_info;
+  mach_map_[pid] = MACH_PORT_NULL;
 }
 
-// Updates the mapping for |pid| to include the given |mach_info|.
-void MachBroker::FinalizePid(base::ProcessHandle pid,
-                             const MachInfo& mach_info) {
-  lock_.AssertAcquired();
-
-  const int count = mach_map_.count(pid);
-  if (count == 0) {
-    // Do nothing for unknown pids.
-    LOG(ERROR) << "Unknown process " << pid << " is sending Mach IPC messages!";
-    return;
-  }
-
-  DCHECK_EQ(1, count);
-  DCHECK(mach_map_[pid].mach_task_ == MACH_PORT_NULL);
-  if (mach_map_[pid].mach_task_ == MACH_PORT_NULL)
-    mach_map_[pid] = mach_info;
-}
-
-// Removes all mappings belonging to |pid| from the broker.
-void MachBroker::InvalidatePid(base::ProcessHandle pid) {
-  base::AutoLock lock(lock_);
-  MachBroker::MachMap::iterator it = mach_map_.find(pid);
-  if (it == mach_map_.end())
-    return;
-
-  kern_return_t kr = mach_port_deallocate(mach_task_self(),
-                                          it->second.mach_task_);
-  LOG_IF(WARNING, kr != KERN_SUCCESS)
-     << "Failed to mach_port_deallocate mach task " << it->second.mach_task_
-     << ", error " << MachErrorCode(kr);
-  mach_map_.erase(it);
-}
-
-base::Lock& MachBroker::GetLock() {
-  return lock_;
-}
-
-// Returns the mach task belonging to |pid|.
 mach_port_t MachBroker::TaskForPid(base::ProcessHandle pid) const {
   base::AutoLock lock(lock_);
   MachBroker::MachMap::const_iterator it = mach_map_.find(pid);
   if (it == mach_map_.end())
     return MACH_PORT_NULL;
-  return it->second.mach_task_;
+  return it->second;
 }
 
 void MachBroker::BrowserChildProcessHostDisconnected(
@@ -203,6 +250,41 @@ void MachBroker::Observe(int type,
   InvalidatePid(handle);
 }
 
+MachBroker::MachBroker() : listener_thread_started_(false) {
+}
+
+MachBroker::~MachBroker() {}
+
+void MachBroker::FinalizePid(base::ProcessHandle pid,
+                             mach_port_t task_port) {
+  lock_.AssertAcquired();
+
+  MachMap::iterator it = mach_map_.find(pid);
+  if (it == mach_map_.end()) {
+    // Do nothing for unknown pids.
+    LOG(ERROR) << "Unknown process " << pid << " is sending Mach IPC messages!";
+    return;
+  }
+
+  DCHECK(it->second == MACH_PORT_NULL);
+  if (it->second == MACH_PORT_NULL)
+    it->second = task_port;
+}
+
+void MachBroker::InvalidatePid(base::ProcessHandle pid) {
+  base::AutoLock lock(lock_);
+  MachBroker::MachMap::iterator it = mach_map_.find(pid);
+  if (it == mach_map_.end())
+    return;
+
+  kern_return_t kr = mach_port_deallocate(mach_task_self(),
+                                          it->second);
+  LOG_IF(WARNING, kr != KERN_SUCCESS)
+     << "Failed to mach_port_deallocate mach task " << it->second
+     << ", error " << MachErrorCode(kr);
+  mach_map_.erase(it);
+}
+
 // static
 std::string MachBroker::GetMachPortName() {
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
@@ -213,11 +295,6 @@ std::string MachBroker::GetMachPortName() {
   return base::StringPrintf("%s.rohitfork.%d", base::mac::BaseBundleID(), pid);
 }
 
-MachBroker::MachBroker() : listener_thread_started_(false) {
-}
-
-MachBroker::~MachBroker() {}
-
 void MachBroker::RegisterNotifications() {
   registrar_.Add(this, NOTIFICATION_RENDERER_PROCESS_CLOSED,
                  NotificationService::AllBrowserContextsAndSources());