Migrating MediaSession messages to mojo

third_party/WebKit/Source/modules/mediasession/MediaMetadataSanitizer.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/mediasession/MediaMetadataSanitizer.h"
+
+#include "modules/mediasession/MediaArtwork.h"
+#include "modules/mediasession/MediaMetadata.h"
+#include "modules/mediasession/MojoMediaMetadata.h"
+#include "public/platform/WebIconSizesParser.h"
+#include "public/platform/WebString.h"
+#include "url/url_constants.h"
+
+namespace blink {
+
+namespace {
+
+// Constants used by the sanitizer, must be consistent with
+// content::MediaMetdataSanitizer.
+
+// Maximum length of all strings inside MediaMetadata when it is sent over mojo.
+const size_t kMaxStringLength = 4 * 1024;
+
+// Maximum type length of MediaArtwork, which conforms to RFC 4288
+// (https://tools.ietf.org/html/rfc4288).
+const size_t kMaxArtworkTypeLength = 2 * 127 + 1;
+
+// Maximum number of artwork images inside the MediaMetadata.
+const size_t kMaxNumberOfArtworkImages = 10;
+
+// Maximum of sizes in an artwork image.
+const size_t kMaxNumberOfArtworkSizes = 10;
+
+bool checkArtworkSrcSanity(const KURL& src) {
+  if (!src.isValid())
+    return false;
+  if (!src.protocolIs(url::kHttpScheme) && !src.protocolIs(url::kHttpsScheme) &&
+      !src.protocolIs(url::kDataScheme)) {
+    return false;
+  }
+  DCHECK(src.getString().is8Bit());
+  if (src.getString().length() > url::kMaxURLChars)
+    return false;
+  return true;
+}
+
+Optional<MojoMediaArtwork> sanitizeArtworkAndConvertToMojo(
+    const MediaArtwork* artwork) {
+  DCHECK(artwork);
+
+  KURL url = KURL(ParsedURLString, artwork->src());
+
+  if (!checkArtworkSrcSanity(url))
+    return WTF::nullopt;
+
+  MojoMediaArtwork mojoArtwork;
+  mojoArtwork.src = url;
+  mojoArtwork.type = artwork->type().left(kMaxArtworkTypeLength);
+  for (const auto& webSize :
+       WebIconSizesParser::parseIconSizes(artwork->sizes())) {
+    mojoArtwork.sizes.append(webSize);
+    if (mojoArtwork.sizes.size() == kMaxNumberOfArtworkSizes)
+      break;
+  }
+  return mojoArtwork;
+}
+
+}  // anonymous namespace
+
+Optional<MojoMediaMetadata> MediaMetadataSanitizer::sanitizeAndConvertToMojo(
+    const MediaMetadata* metadata) {
+  if (!metadata)
+    return WTF::nullopt;
+
+  MojoMediaMetadata mojoMetadata;
+
+  mojoMetadata.title = metadata->title().left(kMaxStringLength);
+  mojoMetadata.artist = metadata->artist().left(kMaxStringLength);
+  mojoMetadata.album = metadata->album().left(kMaxStringLength);
+
+  for (const auto artwork : metadata->artwork()) {
+    Optional<MojoMediaArtwork> mojoArtwork =
+        sanitizeArtworkAndConvertToMojo(artwork.get());
+    if (mojoArtwork.has_value())
+      mojoMetadata.artwork.append(mojoArtwork.value());
+    if (mojoMetadata.artwork.size() == kMaxNumberOfArtworkImages)
+      break;
+  }
+  return mojoMetadata;
+}
+
+}  // namespace blink