dom/locks/LockManager.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   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 "mozilla/dom/LockManager.h"
   8 #include "mozilla/dom/AutoEntryScript.h"
   9 #include "mozilla/dom/WorkerCommon.h"
  10 #include "mozilla/dom/locks/LockManagerChild.h"
  11 #include "mozilla/dom/locks/LockRequestChild.h"
  12 #include "mozilla/Assertions.h"
  13 #include "mozilla/ErrorResult.h"
  14 #include "mozilla/dom/LockManagerBinding.h"
  15 #include "mozilla/dom/Promise.h"
  16 #include "mozilla/dom/locks/PLockManager.h"
  17 #include "mozilla/ipc/BackgroundChild.h"
  18 #include "mozilla/ipc/BackgroundUtils.h"
  19 #include "mozilla/ipc/PBackgroundChild.h"
  20
  21 namespace mozilla::dom {
  22
  23 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(LockManager, mOwner)
  24 NS_IMPL_CYCLE_COLLECTING_ADDREF(LockManager)
  25 NS_IMPL_CYCLE_COLLECTING_RELEASE(LockManager)
  26 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(LockManager)
  27   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  28   NS_INTERFACE_MAP_ENTRY(nsISupports)
  29 NS_INTERFACE_MAP_END
  30
  31 JSObject* LockManager::WrapObject(JSContext* aCx,
  32                                   JS::Handle<JSObject*> aGivenProto) {
  33   return LockManager_Binding::Wrap(aCx, this, aGivenProto);
  34 }
  35
  36 LockManager::LockManager(nsIGlobalObject* aGlobal) : mOwner(aGlobal) {
  37   Maybe<ClientInfo> clientInfo = aGlobal->GetClientInfo();
  38   if (!clientInfo) {
  39     // Pass the nonworking object and let request()/query() throw.
  40     return;
  41   }
  42
  43   nsCOMPtr<nsIPrincipal> principal =
  44       clientInfo->GetPrincipal().unwrapOr(nullptr);
  45   if (!principal || !principal->GetIsContentPrincipal()) {
  46     // Same, the methods will throw instead of the constructor.
  47     return;
  48   }
  49
  50   mozilla::ipc::PBackgroundChild* backgroundActor =
  51       mozilla::ipc::BackgroundChild::GetOrCreateForCurrentThread();
  52   mActor = new locks::LockManagerChild(aGlobal);
  53
  54   if (!backgroundActor->SendPLockManagerConstructor(
  55           mActor, WrapNotNull(principal), clientInfo->Id())) {
  56     // Failed to construct the actor. Pass the nonworking object and let the
  57     // methods throw.
  58     mActor = nullptr;
  59     return;
  60   }
  61 }
  62
  63 already_AddRefed<LockManager> LockManager::Create(nsIGlobalObject& aGlobal) {
  64   RefPtr<LockManager> manager = new LockManager(&aGlobal);
  65
  66   if (!NS_IsMainThread()) {
  67     // Grabbing WorkerRef may fail and that will cause the methods throw later.
  68     manager->mWorkerRef =
  69         WeakWorkerRef::Create(GetCurrentThreadWorkerPrivate(), [manager]() {
  70           // Others may grab a strong reference and block immediate destruction.
  71           // Shutdown early as we don't have to wait for them.
  72           manager->Shutdown();
  73           manager->mWorkerRef = nullptr;
  74         });
  75   }
  76
  77   return manager.forget();
  78 }
  79
  80 static bool ValidateRequestArguments(const nsAString& name,
  81                                      const LockOptions& options,
  82                                      ErrorResult& aRv) {
  83   if (name.Length() > 0 && name.First() == u'-') {
  84     aRv.ThrowNotSupportedError("Names starting with `-` are reserved");
  85     return false;
  86   }
  87   if (options.mSteal) {
  88     if (options.mIfAvailable) {
  89       aRv.ThrowNotSupportedError(
  90           "`steal` and `ifAvailable` cannot be used together");
  91       return false;
  92     }
  93     if (options.mMode != LockMode::Exclusive) {
  94       aRv.ThrowNotSupportedError(
  95           "`steal` is only supported for exclusive lock requests");
  96       return false;
  97     }
  98   }
  99   if (options.mSignal.WasPassed()) {
 100     if (options.mSteal) {
 101       aRv.ThrowNotSupportedError(
 102           "`steal` and `signal` cannot be used together");
 103       return false;
 104     }
 105     if (options.mIfAvailable) {
 106       aRv.ThrowNotSupportedError(
 107           "`ifAvailable` and `signal` cannot be used together");
 108       return false;
 109     }
 110     if (options.mSignal.Value().Aborted()) {
 111       AutoJSAPI jsapi;
 112       if (!jsapi.Init(options.mSignal.Value().GetParentObject())) {
 113         aRv.ThrowNotSupportedError("Signal's realm isn't active anymore.");
 114         return false;
 115       }
 116
 117       JSContext* cx = jsapi.cx();
 118       JS::Rooted<JS::Value> reason(cx);
 119       options.mSignal.Value().GetReason(cx, &reason);
 120       aRv.MightThrowJSException();
 121       aRv.ThrowJSException(cx, reason);
 122       return false;
 123     }
 124   }
 125   return true;
 126 }
 127
 128 already_AddRefed<Promise> LockManager::Request(const nsAString& aName,
 129                                                LockGrantedCallback& aCallback,
 130                                                ErrorResult& aRv) {
 131   return Request(aName, LockOptions(), aCallback, aRv);
 132 };
 133 already_AddRefed<Promise> LockManager::Request(const nsAString& aName,
 134                                                const LockOptions& aOptions,
 135                                                LockGrantedCallback& aCallback,
 136                                                ErrorResult& aRv) {
 137   if (!mOwner->GetClientInfo()) {
 138     // We do have nsPIDOMWindowInner::IsFullyActive for this kind of check,
 139     // but this should be sufficient here as unloaded iframe is the only
 140     // non-fully-active case that Web Locks should worry about (since it does
 141     // not enter bfcache).
 142     aRv.ThrowInvalidStateError(
 143         "The document of the lock manager is not fully active");
 144     return nullptr;
 145   }
 146
 147   const StorageAccess access = mOwner->GetStorageAccess();
 148   bool allowed =
 149       access > StorageAccess::eDeny ||
 150       (StaticPrefs::
 151            privacy_partition_always_partition_third_party_non_cookie_storage() &&
 152        ShouldPartitionStorage(access));
 153   if (!allowed) {
 154     // Step 4: If origin is an opaque origin, then return a promise rejected
 155     // with a "SecurityError" DOMException.
 156     // But per https://w3c.github.io/web-locks/#lock-managers this really means
 157     // whether it has storage access.
 158     aRv.ThrowSecurityError("request() is not allowed in this context");
 159     return nullptr;
 160   }
 161
 162   if (!mActor) {
 163     aRv.ThrowNotSupportedError(
 164         "Web Locks API is not enabled for this kind of document");
 165     return nullptr;
 166   }
 167
 168   if (!NS_IsMainThread() && !mWorkerRef) {
 169     aRv.ThrowInvalidStateError("request() is not allowed at this point");
 170     return nullptr;
 171   }
 172
 173   if (!ValidateRequestArguments(aName, aOptions, aRv)) {
 174     return nullptr;
 175   }
 176
 177   RefPtr<Promise> promise = Promise::Create(mOwner, aRv);
 178   if (aRv.Failed()) {
 179     return nullptr;
 180   }
 181
 182   mActor->RequestLock({nsString(aName), promise, &aCallback}, aOptions);
 183   return promise.forget();
 184 };
 185
 186 already_AddRefed<Promise> LockManager::Query(ErrorResult& aRv) {
 187   if (!mOwner->GetClientInfo()) {
 188     aRv.ThrowInvalidStateError(
 189         "The document of the lock manager is not fully active");
 190     return nullptr;
 191   }
 192
 193   if (mOwner->GetStorageAccess() <= StorageAccess::eDeny) {
 194     aRv.ThrowSecurityError("query() is not allowed in this context");
 195     return nullptr;
 196   }
 197
 198   if (!mActor) {
 199     aRv.ThrowNotSupportedError(
 200         "Web Locks API is not enabled for this kind of document");
 201     return nullptr;
 202   }
 203
 204   if (!NS_IsMainThread() && !mWorkerRef) {
 205     aRv.ThrowInvalidStateError("query() is not allowed at this point");
 206     return nullptr;
 207   }
 208
 209   RefPtr<Promise> promise = Promise::Create(mOwner, aRv);
 210   if (aRv.Failed()) {
 211     return nullptr;
 212   }
 213
 214   mActor->SendQuery()->Then(
 215       GetCurrentSerialEventTarget(), __func__,
 216       [promise](locks::LockManagerChild::QueryPromise::ResolveOrRejectValue&&
 217                     aResult) {
 218         if (aResult.IsResolve()) {
 219           promise->MaybeResolve(aResult.ResolveValue());
 220         } else {
 221           promise->MaybeRejectWithUnknownError("Query failed");
 222         }
 223       });
 224   return promise.forget();
 225 };
 226
 227 void LockManager::Shutdown() {
 228   if (mActor) {
 229     locks::PLockManagerChild::Send__delete__(mActor);
 230     mActor = nullptr;
 231   }
 232 }
 233
 234 }  // namespace mozilla::dom