Start all children in their own PID namespace.

sandbox/linux/services/credentials.cc

 // Copyright (c) 2013 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 "sandbox/linux/services/credentials.h"
 
 #include <errno.h>
 #include <signal.h>
 #include <stdio.h>
 #include <sys/capability.h>
@@ skipping 130 matching lines @@
   CHECK(!HasAnyCapability());
   // We never let this function fail.
   return true;
 }
 
 bool Credentials::DropAllCapabilities() {
   base::ScopedFD proc_fd(ProcUtil::OpenProc());
   return Credentials::DropAllCapabilities(proc_fd.get());
 }
 
+// static
+bool Credentials::SetCapabilities(int proc_fd,
+                                  const std::vector<cap_value_t>& caps) {
+  DCHECK_LE(0, proc_fd);
+  CHECK(ThreadHelpers::IsSingleThreaded(proc_fd));
+
+  sandbox::ScopedCap cap(cap_init());
+  PCHECK(cap != nullptr);
+  cap_flag_t flags[] = {CAP_EFFECTIVE, CAP_PERMITTED};
+  for (const cap_flag_t flag : flags) {
+    PCHECK(cap_set_flag(cap.get(), flag, caps.size(), &caps[0], CAP_SET) == 0);
+  }
+  return cap_set_proc(cap.get()) == 0;
+}
+
 bool Credentials::HasAnyCapability() {
   ScopedCap current_cap(cap_get_proc());
   CHECK(current_cap);
   ScopedCap empty_cap(cap_init());
   CHECK(empty_cap);
   return cap_compare(current_cap.get(), empty_cap.get()) != 0;
 }
 
 scoped_ptr<std::string> Credentials::GetCurrentCapString() {
   ScopedCap current_cap(cap_get_proc());
@@ skipping 73 matching lines @@
   CHECK_LE(0, proc_fd);
 
   CHECK(ChrootToSafeEmptyDir());
   CHECK(!base::DirectoryExists(base::FilePath("/proc")));
   CHECK(!ProcUtil::HasOpenDirectory(proc_fd));
   // We never let this function fail.
   return true;
 }
 
 }  // namespace sandbox.