dom/filesystem/FileSystemSecurity.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "FileSystemSecurity.h"
   8 #include "FileSystemUtils.h"
   9 #include "mozilla/ClearOnShutdown.h"
  10 #include "mozilla/ipc/BackgroundParent.h"
  11 #include "mozilla/StaticPtr.h"
  12
  13 namespace mozilla::dom {
  14
  15 namespace {
  16
  17 StaticRefPtr<FileSystemSecurity> gFileSystemSecurity;
  18
  19 }  // namespace
  20
  21 /* static */
  22 already_AddRefed<FileSystemSecurity> FileSystemSecurity::Get() {
  23   MOZ_ASSERT(NS_IsMainThread());
  24   mozilla::ipc::AssertIsInMainProcess();
  25
  26   RefPtr<FileSystemSecurity> service = gFileSystemSecurity.get();
  27   return service.forget();
  28 }
  29
  30 /* static */
  31 already_AddRefed<FileSystemSecurity> FileSystemSecurity::GetOrCreate() {
  32   MOZ_ASSERT(NS_IsMainThread());
  33   mozilla::ipc::AssertIsInMainProcess();
  34
  35   if (!gFileSystemSecurity) {
  36     gFileSystemSecurity = new FileSystemSecurity();
  37     ClearOnShutdown(&gFileSystemSecurity);
  38   }
  39
  40   RefPtr<FileSystemSecurity> service = gFileSystemSecurity.get();
  41   return service.forget();
  42 }
  43
  44 FileSystemSecurity::FileSystemSecurity() {
  45   MOZ_ASSERT(NS_IsMainThread());
  46   mozilla::ipc::AssertIsInMainProcess();
  47 }
  48
  49 FileSystemSecurity::~FileSystemSecurity() {
  50   MOZ_ASSERT(NS_IsMainThread());
  51   mozilla::ipc::AssertIsInMainProcess();
  52 }
  53
  54 void FileSystemSecurity::GrantAccessToContentProcess(
  55     ContentParentId aId, const nsAString& aDirectoryPath) {
  56   MOZ_ASSERT(NS_IsMainThread());
  57   mozilla::ipc::AssertIsInMainProcess();
  58
  59   mPaths.WithEntryHandle(aId, [&](auto&& entry) {
  60     if (entry && entry.Data()->Contains(aDirectoryPath)) {
  61       return;
  62     }
  63
  64     entry.OrInsertWith([] { return MakeUnique<nsTArray<nsString>>(); })
  65         ->AppendElement(aDirectoryPath);
  66   });
  67 }
  68
  69 void FileSystemSecurity::Forget(ContentParentId aId) {
  70   MOZ_ASSERT(NS_IsMainThread());
  71   mozilla::ipc::AssertIsInMainProcess();
  72
  73   mPaths.Remove(aId);
  74 }
  75
  76 bool FileSystemSecurity::ContentProcessHasAccessTo(ContentParentId aId,
  77                                                    const nsAString& aPath) {
  78   MOZ_ASSERT(NS_IsMainThread());
  79   mozilla::ipc::AssertIsInMainProcess();
  80
  81 #if defined(XP_WIN)
  82   if (StringBeginsWith(aPath, u"..\\"_ns) ||
  83       FindInReadable(u"\\..\\"_ns, aPath)) {
  84     return false;
  85   }
  86 #elif defined(XP_UNIX)
  87   if (StringBeginsWith(aPath, u"../"_ns) || FindInReadable(u"/../"_ns, aPath)) {
  88     return false;
  89   }
  90 #endif
  91
  92   nsTArray<nsString>* paths;
  93   if (!mPaths.Get(aId, &paths)) {
  94     return false;
  95   }
  96
  97   for (uint32_t i = 0, len = paths->Length(); i < len; ++i) {
  98     if (FileSystemUtils::IsDescendantPath(paths->ElementAt(i), aPath)) {
  99       return true;
 100     }
 101   }
 102
 103   return false;
 104 }
 105
 106 }  // namespace mozilla::dom