tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

HTMLDNSPrefetch.h (4967B)

      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 #ifndef mozilla_dom_HTMLDNSPrefetch_h___
      8 #define mozilla_dom_HTMLDNSPrefetch_h___
      9 
     10 #include "nsCOMPtr.h"
     11 #include "nsIDNSService.h"
     12 #include "nsIRequest.h"
     13 #include "nsString.h"
     14 
     15 class nsITimer;
     16 class nsIURI;
     17 namespace mozilla {
     18 
     19 class OriginAttributes;
     20 
     21 namespace net {
     22 class NeckoParent;
     23 }  // namespace net
     24 
     25 namespace dom {
     26 class Document;
     27 class Element;
     28 
     29 class SupportsDNSPrefetch;
     30 
     31 class HTMLDNSPrefetch {
     32 public:
     33  // The required aDocument parameter is the context requesting the prefetch -
     34  // under certain circumstances (e.g. headers, or security context) associated
     35  // with the context the prefetch will not be performed.
     36  static bool IsAllowed(Document* aDocument);
     37 
     38  static nsresult Initialize();
     39  static nsresult Shutdown();
     40 
     41  // Call one of the Prefetch* methods to start the lookup.
     42  //
     43  // The URI versions will defer DNS lookup until pageload is
     44  // complete, while the string versions submit the lookup to
     45  // the DNS system immediately. The URI version is somewhat lighter
     46  // weight, but its request is also more likely to be dropped due to a
     47  // full queue and it may only be used from the main thread.
     48  //
     49  // If you are planning to use the methods with the OriginAttributes param, be
     50  // sure that you pass a partitioned one. See StoragePrincipalHelper.h to know
     51  // more.
     52 
     53  enum class Priority {
     54    Low,
     55    Medium,
     56    High,
     57  };
     58  enum class PrefetchSource {
     59    LinkDnsPrefetch,
     60    AnchorSpeculativePrefetch,
     61  };
     62  static nsresult DeferPrefetch(SupportsDNSPrefetch& aSupports,
     63                                Element& aElement, Priority aPriority);
     64  static void SendRequest(Element& aElement, nsIDNSService::DNSFlags aFlags);
     65  static nsresult Prefetch(
     66      const nsAString& host, bool isHttps,
     67      const OriginAttributes& aPartitionedPrincipalOriginAttributes,
     68      nsIRequest::TRRMode aTRRMode, Priority);
     69  static nsresult CancelPrefetch(
     70      const nsAString& host, bool isHttps,
     71      const OriginAttributes& aPartitionedPrincipalOriginAttributes,
     72      nsIRequest::TRRMode aTRRMode, Priority, nsresult aReason);
     73  static nsresult CancelPrefetch(SupportsDNSPrefetch&, Element&, Priority,
     74                                 nsresult aReason);
     75  static void ElementDestroyed(Element&, SupportsDNSPrefetch&);
     76 
     77  static nsIDNSService::DNSFlags PriorityToDNSServiceFlags(Priority);
     78 
     79 private:
     80  static nsresult Prefetch(
     81      const nsAString& host, bool isHttps,
     82      const OriginAttributes& aPartitionedPrincipalOriginAttributes,
     83      nsIDNSService::DNSFlags flags);
     84  static nsresult CancelPrefetch(
     85      const nsAString& hostname, bool isHttps,
     86      const OriginAttributes& aPartitionedPrincipalOriginAttributes,
     87      nsIDNSService::DNSFlags flags, nsresult aReason);
     88 
     89  friend class net::NeckoParent;
     90 };
     91 
     92 // Elements that support DNS prefetch are expected to subclass this.
     93 class SupportsDNSPrefetch {
     94 public:
     95  bool IsInDNSPrefetch() { return mInDNSPrefetch; }
     96  void SetIsInDNSPrefetch() { mInDNSPrefetch = true; }
     97  void ClearIsInDNSPrefetch() { mInDNSPrefetch = false; }
     98 
     99  void DNSPrefetchRequestStarted() {
    100    mDNSPrefetchDeferred = false;
    101    mDNSPrefetchRequested = true;
    102  }
    103 
    104  void DNSPrefetchRequestDeferred() {
    105    mDNSPrefetchDeferred = true;
    106    mDNSPrefetchRequested = false;
    107  }
    108 
    109  bool IsDNSPrefetchRequestDeferred() const { return mDNSPrefetchDeferred; }
    110 
    111  // This could be a virtual function or something like that, but that would
    112  // cause our subclasses to grow by two pointers, rather than just 1 byte at
    113  // most.
    114  nsIURI* GetURIForDNSPrefetch(Element& aOwner);
    115 
    116 protected:
    117  SupportsDNSPrefetch()
    118      : mInDNSPrefetch(false),
    119        mDNSPrefetchRequested(false),
    120        mDNSPrefetchDeferred(false),
    121        mDestroyedCalled(false) {}
    122 
    123  void CancelDNSPrefetch(Element& aOwner);
    124  void TryDNSPrefetch(Element& aOwner, HTMLDNSPrefetch::PrefetchSource aSource);
    125 
    126  // This MUST be called on the destructor of the Element subclass.
    127  // Our own destructor ensures that.
    128  void Destroyed(Element& aOwner) {
    129    MOZ_DIAGNOSTIC_ASSERT(!mDestroyedCalled,
    130                          "Multiple calls to SupportsDNSPrefetch::Destroyed?");
    131    mDestroyedCalled = true;
    132    if (mInDNSPrefetch) {
    133      HTMLDNSPrefetch::ElementDestroyed(aOwner, *this);
    134    }
    135  }
    136 
    137  ~SupportsDNSPrefetch() {
    138    MOZ_DIAGNOSTIC_ASSERT(mDestroyedCalled,
    139                          "Need to call SupportsDNSPrefetch::Destroyed "
    140                          "from the owner element");
    141  }
    142 
    143 private:
    144  bool mInDNSPrefetch : 1;
    145  bool mDNSPrefetchRequested : 1;
    146  bool mDNSPrefetchDeferred : 1;
    147  bool mDestroyedCalled : 1;
    148 };
    149 
    150 }  // namespace dom
    151 }  // namespace mozilla
    152 
    153 #endif