dom/html/HTMLSharedElement.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 "mozilla/dom/HTMLSharedElement.h"
   8 #include "mozilla/dom/BindContext.h"
   9 #include "mozilla/dom/HTMLBaseElementBinding.h"
  10 #include "mozilla/dom/HTMLDirectoryElementBinding.h"
  11 #include "mozilla/dom/HTMLHeadElementBinding.h"
  12 #include "mozilla/dom/HTMLHtmlElementBinding.h"
  13 #include "mozilla/dom/HTMLParamElementBinding.h"
  14 #include "mozilla/dom/HTMLQuoteElementBinding.h"
  15
  16 #include "mozilla/AsyncEventDispatcher.h"
  17 #include "nsContentUtils.h"
  18 #include "nsIContentSecurityPolicy.h"
  19 #include "nsIURI.h"
  20
  21 NS_IMPL_NS_NEW_HTML_ELEMENT(Shared)
  22
  23 namespace mozilla::dom {
  24
  25 HTMLSharedElement::~HTMLSharedElement() = default;
  26
  27 NS_IMPL_ELEMENT_CLONE(HTMLSharedElement)
  28
  29 void HTMLSharedElement::GetHref(nsAString& aValue) {
  30   MOZ_ASSERT(mNodeInfo->Equals(nsGkAtoms::base),
  31              "This should only get called for <base> elements");
  32   nsAutoString href;
  33   GetAttr(nsGkAtoms::href, href);
  34
  35   nsCOMPtr<nsIURI> uri;
  36   Document* doc = OwnerDoc();
  37   nsContentUtils::NewURIWithDocumentCharset(getter_AddRefs(uri), href, doc,
  38                                             doc->GetFallbackBaseURI());
  39
  40   if (!uri) {
  41     aValue = href;
  42     return;
  43   }
  44
  45   nsAutoCString spec;
  46   uri->GetSpec(spec);
  47   CopyUTF8toUTF16(spec, aValue);
  48 }
  49
  50 void HTMLSharedElement::DoneAddingChildren(bool aHaveNotified) {
  51   if (mNodeInfo->Equals(nsGkAtoms::head)) {
  52     if (nsCOMPtr<Document> doc = GetUncomposedDoc()) {
  53       doc->OnL10nResourceContainerParsed();
  54       if (!doc->IsLoadedAsData()) {
  55         RefPtr<AsyncEventDispatcher> asyncDispatcher =
  56             new AsyncEventDispatcher(this, u"DOMHeadElementParsed"_ns,
  57                                      CanBubble::eYes, ChromeOnlyDispatch::eYes);
  58         // Always run async in order to avoid running script when the content
  59         // sink isn't expecting it.
  60         asyncDispatcher->PostDOMEvent();
  61       }
  62     }
  63   }
  64 }
  65
  66 static void SetBaseURIUsingFirstBaseWithHref(Document* aDocument,
  67                                              nsIContent* aMustMatch) {
  68   MOZ_ASSERT(aDocument, "Need a document!");
  69
  70   for (nsIContent* child = aDocument->GetFirstChild(); child;
  71        child = child->GetNextNode()) {
  72     if (child->IsHTMLElement(nsGkAtoms::base) &&
  73         child->AsElement()->HasAttr(nsGkAtoms::href)) {
  74       if (aMustMatch && child != aMustMatch) {
  75         return;
  76       }
  77
  78       // Resolve the <base> element's href relative to our document's
  79       // fallback base URI.
  80       nsAutoString href;
  81       child->AsElement()->GetAttr(nsGkAtoms::href, href);
  82
  83       nsCOMPtr<nsIURI> newBaseURI;
  84       nsContentUtils::NewURIWithDocumentCharset(
  85           getter_AddRefs(newBaseURI), href, aDocument,
  86           aDocument->GetFallbackBaseURI());
  87
  88       // Vaguely based on
  89       // <https://html.spec.whatwg.org/multipage/semantics.html#set-the-frozen-base-url>
  90
  91       if (newBaseURI && (newBaseURI->SchemeIs("data") ||
  92                          newBaseURI->SchemeIs("javascript"))) {
  93         newBaseURI = nullptr;
  94       }
  95
  96       // Check if CSP allows this base-uri
  97       nsCOMPtr<nsIContentSecurityPolicy> csp = aDocument->GetCsp();
  98       if (csp && newBaseURI) {
  99         // base-uri is only enforced if explicitly defined in the
 100         // policy - do *not* consult default-src, see:
 101         // http://www.w3.org/TR/CSP2/#directive-default-src
 102         bool cspPermitsBaseURI = true;
 103         nsresult rv = csp->Permits(
 104             child->AsElement(), nullptr /* nsICSPEventListener */, newBaseURI,
 105             nsIContentSecurityPolicy::BASE_URI_DIRECTIVE, true /* aSpecific */,
 106             true /* aSendViolationReports */, &cspPermitsBaseURI);
 107         if (NS_FAILED(rv) || !cspPermitsBaseURI) {
 108           newBaseURI = nullptr;
 109         }
 110       }
 111
 112       aDocument->SetBaseURI(newBaseURI);
 113       aDocument->SetChromeXHRDocBaseURI(nullptr);
 114       return;
 115     }
 116   }
 117
 118   aDocument->SetBaseURI(nullptr);
 119 }
 120
 121 static void SetBaseTargetUsingFirstBaseWithTarget(Document* aDocument,
 122                                                   nsIContent* aMustMatch) {
 123   MOZ_ASSERT(aDocument, "Need a document!");
 124
 125   for (nsIContent* child = aDocument->GetFirstChild(); child;
 126        child = child->GetNextNode()) {
 127     if (child->IsHTMLElement(nsGkAtoms::base) &&
 128         child->AsElement()->HasAttr(nsGkAtoms::target)) {
 129       if (aMustMatch && child != aMustMatch) {
 130         return;
 131       }
 132
 133       nsString target;
 134       child->AsElement()->GetAttr(nsGkAtoms::target, target);
 135       aDocument->SetBaseTarget(target);
 136       return;
 137     }
 138   }
 139
 140   aDocument->SetBaseTarget(u""_ns);
 141 }
 142
 143 void HTMLSharedElement::AfterSetAttr(int32_t aNamespaceID, nsAtom* aName,
 144                                      const nsAttrValue* aValue,
 145                                      const nsAttrValue* aOldValue,
 146                                      nsIPrincipal* aSubjectPrincipal,
 147                                      bool aNotify) {
 148   if (aNamespaceID == kNameSpaceID_None) {
 149     if (aName == nsGkAtoms::href) {
 150       // If the href attribute of a <base> tag is changing, we may need to
 151       // update the document's base URI, which will cause all the links on the
 152       // page to be re-resolved given the new base.
 153       // If the href is being unset (aValue is null), we will need to find a new
 154       // <base>.
 155       if (mNodeInfo->Equals(nsGkAtoms::base) && IsInUncomposedDoc()) {
 156         SetBaseURIUsingFirstBaseWithHref(GetUncomposedDoc(),
 157                                          aValue ? this : nullptr);
 158       }
 159     } else if (aName == nsGkAtoms::target) {
 160       // The target attribute is in pretty much the same situation as the href
 161       // attribute, above.
 162       if (mNodeInfo->Equals(nsGkAtoms::base) && IsInUncomposedDoc()) {
 163         SetBaseTargetUsingFirstBaseWithTarget(GetUncomposedDoc(),
 164                                               aValue ? this : nullptr);
 165       }
 166     }
 167   }
 168
 169   return nsGenericHTMLElement::AfterSetAttr(
 170       aNamespaceID, aName, aValue, aOldValue, aSubjectPrincipal, aNotify);
 171 }
 172
 173 nsresult HTMLSharedElement::BindToTree(BindContext& aContext,
 174                                        nsINode& aParent) {
 175   nsresult rv = nsGenericHTMLElement::BindToTree(aContext, aParent);
 176   NS_ENSURE_SUCCESS(rv, rv);
 177
 178   // The document stores a pointer to its base URI and base target, which we may
 179   // need to update here.
 180   if (mNodeInfo->Equals(nsGkAtoms::base) && IsInUncomposedDoc()) {
 181     if (HasAttr(nsGkAtoms::href)) {
 182       SetBaseURIUsingFirstBaseWithHref(&aContext.OwnerDoc(), this);
 183     }
 184     if (HasAttr(nsGkAtoms::target)) {
 185       SetBaseTargetUsingFirstBaseWithTarget(&aContext.OwnerDoc(), this);
 186     }
 187   }
 188
 189   return NS_OK;
 190 }
 191
 192 void HTMLSharedElement::UnbindFromTree(UnbindContext& aContext) {
 193   Document* doc = GetUncomposedDoc();
 194
 195   nsGenericHTMLElement::UnbindFromTree(aContext);
 196
 197   // If we're removing a <base> from a document, we may need to update the
 198   // document's base URI and base target
 199   if (doc && mNodeInfo->Equals(nsGkAtoms::base)) {
 200     if (HasAttr(nsGkAtoms::href)) {
 201       SetBaseURIUsingFirstBaseWithHref(doc, nullptr);
 202     }
 203     if (HasAttr(nsGkAtoms::target)) {
 204       SetBaseTargetUsingFirstBaseWithTarget(doc, nullptr);
 205     }
 206   }
 207 }
 208
 209 JSObject* HTMLSharedElement::WrapNode(JSContext* aCx,
 210                                       JS::Handle<JSObject*> aGivenProto) {
 211   if (mNodeInfo->Equals(nsGkAtoms::param)) {
 212     return HTMLParamElement_Binding::Wrap(aCx, this, aGivenProto);
 213   }
 214   if (mNodeInfo->Equals(nsGkAtoms::base)) {
 215     return HTMLBaseElement_Binding::Wrap(aCx, this, aGivenProto);
 216   }
 217   if (mNodeInfo->Equals(nsGkAtoms::dir)) {
 218     return HTMLDirectoryElement_Binding::Wrap(aCx, this, aGivenProto);
 219   }
 220   if (mNodeInfo->Equals(nsGkAtoms::q) ||
 221       mNodeInfo->Equals(nsGkAtoms::blockquote)) {
 222     return HTMLQuoteElement_Binding::Wrap(aCx, this, aGivenProto);
 223   }
 224   if (mNodeInfo->Equals(nsGkAtoms::head)) {
 225     return HTMLHeadElement_Binding::Wrap(aCx, this, aGivenProto);
 226   }
 227   MOZ_ASSERT(mNodeInfo->Equals(nsGkAtoms::html));
 228   return HTMLHtmlElement_Binding::Wrap(aCx, this, aGivenProto);
 229 }
 230
 231 }  // namespace mozilla::dom