content/browser/renderer_host/pepper/pepper_security_helper.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/renderer_host/pepper/pepper_security_helper.h"
   6
   7 #include "base/logging.h"
   8 #include "content/browser/child_process_security_policy_impl.h"
   9 #include "ppapi/c/ppb_file_io.h"
  10
  11 namespace content {
  12
  13 namespace {
  14
  15 template <typename CanRead, typename CanWrite,
  16           typename CanCreate, typename CanCreateReadWrite,
  17           typename FileID>
  18 bool CanOpenFileWithPepperFlags(CanRead can_read,
  19                                 CanWrite can_write,
  20                                 CanCreate can_create,
  21                                 CanCreateReadWrite can_create_read_write,
  22                                 int pp_open_flags,
  23                                 int child_id,
  24                                 const FileID& file) {
  25   ChildProcessSecurityPolicyImpl* policy =
  26       ChildProcessSecurityPolicyImpl::GetInstance();
  27
  28   bool pp_read = !!(pp_open_flags & PP_FILEOPENFLAG_READ);
  29   bool pp_write = !!(pp_open_flags & PP_FILEOPENFLAG_WRITE);
  30   bool pp_create = !!(pp_open_flags & PP_FILEOPENFLAG_CREATE);
  31   bool pp_truncate = !!(pp_open_flags & PP_FILEOPENFLAG_TRUNCATE);
  32   bool pp_exclusive = !!(pp_open_flags & PP_FILEOPENFLAG_EXCLUSIVE);
  33   bool pp_append = !!(pp_open_flags & PP_FILEOPENFLAG_APPEND);
  34
  35   if (pp_read && !(policy->*can_read)(child_id, file))
  36     return false;
  37
  38   if (pp_write && !(policy->*can_write)(child_id, file))
  39     return false;
  40
  41   // TODO(tommycli): Maybe tighten up required permission. crbug.com/284792
  42   if (pp_append && !(policy->*can_create_read_write)(child_id, file))
  43     return false;
  44
  45   if (pp_truncate && !pp_write)
  46     return false;
  47
  48   if (pp_create) {
  49     if (pp_exclusive) {
  50       return (policy->*can_create)(child_id, file);
  51     } else {
  52       // Asks for too much, but this is the only grant that allows overwrite.
  53       return (policy->*can_create_read_write)(child_id, file);
  54     }
  55   } else if (pp_truncate) {
  56     return (policy->*can_create_read_write)(child_id, file);
  57   }
  58
  59   return true;
  60 }
  61
  62 }
  63
  64 bool CanOpenWithPepperFlags(int pp_open_flags, int child_id,
  65                             const base::FilePath& file) {
  66   return CanOpenFileWithPepperFlags(
  67       &ChildProcessSecurityPolicyImpl::CanReadFile,
  68       &ChildProcessSecurityPolicyImpl::CanCreateReadWriteFile,
  69       &ChildProcessSecurityPolicyImpl::CanCreateReadWriteFile,
  70       &ChildProcessSecurityPolicyImpl::CanCreateReadWriteFile,
  71       pp_open_flags, child_id, file);
  72 }
  73
  74 bool CanOpenFileSystemURLWithPepperFlags(int pp_open_flags, int child_id,
  75                                          const fileapi::FileSystemURL& url) {
  76   return CanOpenFileWithPepperFlags(
  77       &ChildProcessSecurityPolicyImpl::CanReadFileSystemFile,
  78       &ChildProcessSecurityPolicyImpl::CanWriteFileSystemFile,
  79       &ChildProcessSecurityPolicyImpl::CanCreateFileSystemFile,
  80       &ChildProcessSecurityPolicyImpl::CanCreateReadWriteFileSystemFile,
  81       pp_open_flags, child_id, url);
  82 }
  83
  84 }  // namespace content