caps/SystemPrincipal.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* The privileged system principal. */
   7
   8 #include "nscore.h"
   9 #include "SystemPrincipal.h"
  10 #include "mozilla/ClearOnShutdown.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsReadableUtils.h"
  13 #include "nsCRT.h"
  14 #include "nsString.h"
  15 #include "nsIClassInfoImpl.h"
  16 #include "pratom.h"
  17
  18 using namespace mozilla;
  19
  20 NS_IMPL_CLASSINFO(SystemPrincipal, nullptr, nsIClassInfo::SINGLETON,
  21                   NS_SYSTEMPRINCIPAL_CID)
  22 NS_IMPL_QUERY_INTERFACE_CI(SystemPrincipal, nsIPrincipal, nsISerializable)
  23 NS_IMPL_CI_INTERFACE_GETTER(SystemPrincipal, nsIPrincipal, nsISerializable)
  24
  25 static constexpr nsLiteralCString kSystemPrincipalSpec =
  26     "[System Principal]"_ns;
  27
  28 SystemPrincipal::SystemPrincipal()
  29     : BasePrincipal(eSystemPrincipal, kSystemPrincipalSpec,
  30                     OriginAttributes()) {}
  31
  32 static StaticMutex sSystemPrincipalMutex;
  33 static StaticRefPtr<SystemPrincipal> sSystemPrincipal
  34     MOZ_GUARDED_BY(sSystemPrincipalMutex);
  35
  36 already_AddRefed<SystemPrincipal> SystemPrincipal::Get() {
  37   StaticMutexAutoLock lock(sSystemPrincipalMutex);
  38   return do_AddRef(sSystemPrincipal);
  39 }
  40
  41 already_AddRefed<SystemPrincipal> SystemPrincipal::Init() {
  42   AssertIsOnMainThread();
  43   StaticMutexAutoLock lock(sSystemPrincipalMutex);
  44   if (MOZ_UNLIKELY(sSystemPrincipal)) {
  45     MOZ_ASSERT_UNREACHABLE("SystemPrincipal::Init() may only be called once");
  46   } else {
  47     sSystemPrincipal = new SystemPrincipal();
  48   }
  49   return do_AddRef(sSystemPrincipal);
  50 }
  51
  52 void SystemPrincipal::Shutdown() {
  53   AssertIsOnMainThread();
  54   StaticMutexAutoLock lock(sSystemPrincipalMutex);
  55   MOZ_ASSERT(sSystemPrincipal);
  56   sSystemPrincipal = nullptr;
  57 }
  58
  59 nsresult SystemPrincipal::GetScriptLocation(nsACString& aStr) {
  60   aStr.Assign(kSystemPrincipalSpec);
  61   return NS_OK;
  62 }
  63
  64 ///////////////////////////////////////
  65 // Methods implementing nsIPrincipal //
  66 ///////////////////////////////////////
  67
  68 uint32_t SystemPrincipal::GetHashValue() { return NS_PTR_TO_INT32(this); }
  69
  70 NS_IMETHODIMP
  71 SystemPrincipal::GetURI(nsIURI** aURI) {
  72   *aURI = nullptr;
  73   return NS_OK;
  74 }
  75
  76 NS_IMETHODIMP
  77 SystemPrincipal::GetIsOriginPotentiallyTrustworthy(bool* aResult) {
  78   *aResult = true;
  79   return NS_OK;
  80 }
  81
  82 NS_IMETHODIMP
  83 SystemPrincipal::GetDomain(nsIURI** aDomain) {
  84   *aDomain = nullptr;
  85   return NS_OK;
  86 }
  87
  88 NS_IMETHODIMP
  89 SystemPrincipal::SetDomain(nsIURI* aDomain) { return NS_OK; }
  90
  91 NS_IMETHODIMP
  92 SystemPrincipal::GetBaseDomain(nsACString& aBaseDomain) {
  93   // No base domain for chrome.
  94   return NS_OK;
  95 }
  96
  97 NS_IMETHODIMP
  98 SystemPrincipal::GetAddonId(nsAString& aAddonId) {
  99   aAddonId.Truncate();
 100   return NS_OK;
 101 };
 102
 103 //////////////////////////////////////////
 104 // Methods implementing nsISerializable //
 105 //////////////////////////////////////////
 106
 107 NS_IMETHODIMP
 108 SystemPrincipal::Read(nsIObjectInputStream* aStream) {
 109   // no-op: CID is sufficient to identify the mSystemPrincipal singleton
 110   return NS_OK;
 111 }
 112
 113 NS_IMETHODIMP
 114 SystemPrincipal::Write(nsIObjectOutputStream* aStream) {
 115   // Read is used still for legacy principals
 116   MOZ_RELEASE_ASSERT(false, "Old style serialization is removed");
 117   return NS_OK;
 118 }