diff --git a/app/lib/link_details_extractor.rb b/app/lib/link_details_extractor.rb
new file mode 100644
index 00000000000..9df8a132075
--- /dev/null
+++ b/app/lib/link_details_extractor.rb
@@ -0,0 +1,200 @@
+# frozen_string_literal: true
+
+class LinkDetailsExtractor
+ include ActionView::Helpers::TagHelper
+
+ class StructuredData
+ def initialize(data)
+ @data = data
+ end
+
+ def headline
+ json['headline']
+ end
+
+ def description
+ json['description']
+ end
+
+ def image
+ obj = first_of_value(json['image'])
+
+ return obj['url'] if obj.is_a?(Hash)
+
+ obj
+ end
+
+ def date_published
+ json['datePublished']
+ end
+
+ def date_modified
+ json['dateModified']
+ end
+
+ def author_name
+ author['name']
+ end
+
+ def author_url
+ author['url']
+ end
+
+ def publisher_name
+ publisher['name']
+ end
+
+ private
+
+ def author
+ first_of_value(json['author']) || {}
+ end
+
+ def publisher
+ first_of_value(json['publisher']) || {}
+ end
+
+ def first_of_value(arr)
+ arr.is_a?(Array) ? arr.first : arr
+ end
+
+ def json
+ @json ||= Oj.load(@data)
+ end
+ end
+
+ def initialize(original_url, html, html_charset)
+ @original_url = Addressable::URI.parse(original_url)
+ @html = html
+ @html_charset = html_charset
+ end
+
+ def to_preview_card_attributes
+ {
+ title: title || '',
+ description: description || '',
+ image_remote_url: image,
+ type: type,
+ width: width || 0,
+ height: height || 0,
+ html: html || '',
+ provider_name: provider_name || '',
+ provider_url: provider_url || '',
+ author_name: author_name || '',
+ author_url: author_url || '',
+ embed_url: embed_url || '',
+ }
+ end
+
+ def type
+ player_url.present? ? :video : :link
+ end
+
+ def html
+ player_url.present? ? content_tag(:iframe, src: player_url, width: width, height: height, allowtransparency: 'true', scrolling: 'no', frameborder: '0') : nil
+ end
+
+ def width
+ opengraph_tag('twitter:player:width')
+ end
+
+ def height
+ opengraph_tag('twitter:player:height')
+ end
+
+ def title
+ structured_data&.headline || opengraph_tag('og:title') || document.xpath('//title').map(&:content).first
+ end
+
+ def description
+ structured_data&.description || opengraph_tag('og:description') || meta_tag('description')
+ end
+
+ def image
+ valid_url_or_nil(opengraph_tag('og:image'))
+ end
+
+ def canonical_url
+ valid_url_or_nil(opengraph_tag('og:url') || link_tag('canonical'), same_origin_only: true) || @original_url.to_s
+ end
+
+ def provider_name
+ structured_data&.publisher_name || opengraph_tag('og:site_name')
+ end
+
+ def provider_url
+ valid_url_or_nil(host_to_url(opengraph_tag('og:site')))
+ end
+
+ def author_name
+ structured_data&.author_name || opengraph_tag('og:author') || opengraph_tag('og:author:username')
+ end
+
+ def author_url
+ structured_data&.author_url
+ end
+
+ def embed_url
+ valid_url_or_nil(opengraph_tag('twitter:player:stream'))
+ end
+
+ private
+
+ def player_url
+ valid_url_or_nil(opengraph_tag('twitter:player'))
+ end
+
+ def host_to_url(str)
+ return if str.blank?
+
+ str.start_with?(/https?:\/\//) ? str : "http://#{str}"
+ end
+
+ def valid_url_or_nil(str, same_origin_only: false)
+ return if str.blank?
+
+ url = @original_url + Addressable::URI.parse(str)
+
+ return if url.host.blank? || !%w(http https).include?(url.scheme) || (same_origin_only && url.host != @original_url.host)
+
+ url.to_s
+ rescue Addressable::URI::InvalidURIError
+ nil
+ end
+
+ def link_tag(name)
+ document.xpath("//link[@rel=\"#{name}\"]").map { |link| link['href'] }.first
+ end
+
+ def opengraph_tag(name)
+ document.xpath("//meta[@property=\"#{name}\" or @name=\"#{name}\"]").map { |meta| meta['content'] }.first
+ end
+
+ def meta_tag(name)
+ document.xpath("//meta[@name=\"#{name}\"]").map { |meta| meta['content'] }.first
+ end
+
+ def structured_data
+ @structured_data ||= begin
+ json_ld = document.xpath('//script[@type="application/ld+json"]').map(&:content).first
+ json_ld.present? ? StructuredData.new(json_ld) : nil
+ end
+ end
+
+ def document
+ @document ||= Nokogiri::HTML(@html, nil, encoding)
+ end
+
+ def encoding
+ @encoding ||= begin
+ guess = detector.detect(@html, @html_charset)
+ guess&.fetch(:confidence, 0).to_i > 60 ? guess&.fetch(:encoding, nil) : nil
+ end
+ end
+
+ def detector
+ @detector ||= CharlockHolmes::EncodingDetector.new.tap do |detector|
+ detector.strip_tags = true
+ end
+ end
+end
diff --git a/app/lib/request.rb b/app/lib/request.rb
index 125dee3ea70..4289da9333d 100644
--- a/app/lib/request.rb
+++ b/app/lib/request.rb
@@ -94,7 +94,7 @@ class Request
end
def http_client
- HTTP.use(:auto_inflate).timeout(TIMEOUT.dup).follow(max_hops: 2)
+ HTTP.use(:auto_inflate).timeout(TIMEOUT.dup).follow(max_hops: 3)
end
end
diff --git a/app/services/fetch_link_card_service.rb b/app/services/fetch_link_card_service.rb
index 5732ce8ace4..51956ce7e07 100644
--- a/app/services/fetch_link_card_service.rb
+++ b/app/services/fetch_link_card_service.rb
@@ -13,12 +13,12 @@ class FetchLinkCardService < BaseService
}iox
def call(status)
- @status = status
- @url = parse_urls
+ @status = status
+ @original_url = parse_urls
- return if @url.nil? || @status.preview_cards.any?
+ return if @original_url.nil? || @status.preview_cards.any?
- @url = @url.to_s
+ @url = @original_url.to_s
RedisLock.acquire(lock_options) do |lock|
if lock.acquired?
@@ -31,7 +31,7 @@ class FetchLinkCardService < BaseService
attach_card if @card&.persisted?
rescue HTTP::Error, OpenSSL::SSL::SSLError, Addressable::URI::InvalidURIError, Mastodon::HostValidationError, Mastodon::LengthValidationError => e
- Rails.logger.debug "Error fetching link #{@url}: #{e}"
+ Rails.logger.debug "Error fetching link #{@original_url}: #{e}"
nil
end
@@ -47,6 +47,12 @@ class FetchLinkCardService < BaseService
return @html if defined?(@html)
Request.new(:get, @url).add_headers('Accept' => 'text/html', 'User-Agent' => Mastodon::Version.user_agent + ' Bot').perform do |res|
+ # We follow redirects, and ideally we want to save the preview card for
+ # the destination URL and not any link shortener in-between, so here
+ # we set the URL to the one of the last response in the redirect chain
+ @url = res.request.uri.to_s.to_s
+ @card = PreviewCard.find_or_initialize_by(url: @url) if @card.url != @url
+
if res.code == 200 && res.mime_type == 'text/html'
@html_charset = res.charset
@html = res.body_with_limit
@@ -63,12 +69,15 @@ class FetchLinkCardService < BaseService
end
def parse_urls
- if @status.local?
- urls = @status.text.scan(URL_PATTERN).map { |array| Addressable::URI.parse(array[1]).normalize }
- else
- html = Nokogiri::HTML(@status.text)
- links = html.css('a')
- urls = links.filter_map { |a| Addressable::URI.parse(a['href']) unless skip_link?(a) }.filter_map(&:normalize)
+ urls = begin
+ if @status.local?
+ @status.text.scan(URL_PATTERN).map { |array| Addressable::URI.parse(array[1]).normalize }
+ else
+ document = Nokogiri::HTML(@status.text)
+ links = document.css('a')
+
+ links.filter_map { |a| Addressable::URI.parse(a['href']) unless skip_link?(a) }.filter_map(&:normalize)
+ end
end
urls.reject { |uri| bad_url?(uri) }.first
@@ -79,18 +88,16 @@ class FetchLinkCardService < BaseService
uri.host.blank? || TagManager.instance.local_url?(uri.to_s) || !%w(http https).include?(uri.scheme)
end
- # rubocop:disable Naming/MethodParameterName
- def mention_link?(a)
+ def mention_link?(anchor)
@status.mentions.any? do |mention|
- a['href'] == ActivityPub::TagManager.instance.url_for(mention.account)
+ anchor['href'] == ActivityPub::TagManager.instance.url_for(mention.account)
end
end
- def skip_link?(a)
+ def skip_link?(anchor)
# Avoid links for hashtags and mentions (microformats)
- a['rel']&.include?('tag') || a['class']&.match?(/u-url|h-card/) || mention_link?(a)
+ anchor['rel']&.include?('tag') || anchor['class']&.match?(/u-url|h-card/) || mention_link?(anchor)
end
- # rubocop:enable Naming/MethodParameterName
def attempt_oembed
service = FetchOEmbedService.new
@@ -139,42 +146,14 @@ class FetchLinkCardService < BaseService
def attempt_opengraph
return if html.nil?
- detector = CharlockHolmes::EncodingDetector.new
- detector.strip_tags = true
+ link_details_extractor = LinkDetailsExtractor.new(@url, @html, @html_charset)
- guess = detector.detect(@html, @html_charset)
- encoding = guess&.fetch(:confidence, 0).to_i > 60 ? guess&.fetch(:encoding, nil) : nil
- page = Nokogiri::HTML(@html, nil, encoding)
- player_url = meta_property(page, 'twitter:player')
-
- if player_url && !bad_url?(Addressable::URI.parse(player_url))
- @card.type = :video
- @card.width = meta_property(page, 'twitter:player:width') || 0
- @card.height = meta_property(page, 'twitter:player:height') || 0
- @card.html = content_tag(:iframe, nil, src: player_url,
- width: @card.width,
- height: @card.height,
- allowtransparency: 'true',
- scrolling: 'no',
- frameborder: '0')
- else
- @card.type = :link
- end
-
- @card.title = meta_property(page, 'og:title').presence || page.at_xpath('//title')&.content || ''
- @card.description = meta_property(page, 'og:description').presence || meta_property(page, 'description') || ''
- @card.image_remote_url = (Addressable::URI.parse(@url) + meta_property(page, 'og:image')).to_s if meta_property(page, 'og:image')
-
- return if @card.title.blank? && @card.html.blank?
-
- @card.save_with_optional_image!
- end
-
- def meta_property(page, property)
- page.at_xpath("//meta[contains(concat(' ', normalize-space(@property), ' '), ' #{property} ')]")&.attribute('content')&.value || page.at_xpath("//meta[@name=\"#{property}\"]")&.attribute('content')&.value
+ @card = PreviewCard.find_or_initialize_by(url: link_details_extractor.canonical_url) if link_details_extractor.canonical_url != @card.url
+ @card.assign_attributes(link_details_extractor.to_preview_card_attributes)
+ @card.save_with_optional_image! unless @card.title.blank? && @card.html.blank?
end
def lock_options
- { redis: Redis.current, key: "fetch:#{@url}", autorelease: 15.minutes.seconds }
+ { redis: Redis.current, key: "fetch:#{@original_url}", autorelease: 15.minutes.seconds }
end
end
diff --git a/spec/lib/link_details_extractor_spec.rb b/spec/lib/link_details_extractor_spec.rb
new file mode 100644
index 00000000000..850857b2dd1
--- /dev/null
+++ b/spec/lib/link_details_extractor_spec.rb
@@ -0,0 +1,29 @@
+require 'rails_helper'
+
+RSpec.describe LinkDetailsExtractor do
+ let(:original_url) { '' }
+ let(:html) { '' }
+ let(:html_charset) { nil }
+
+ subject { described_class.new(original_url, html, html_charset) }
+
+ describe '#canonical_url' do
+ let(:original_url) { 'https://foo.com/article?bar=baz123' }
+
+ context 'when canonical URL points to another host' do
+ let(:html) { '' }
+
+ it 'ignores the canonical URLs' do
+ expect(subject.canonical_url).to eq original_url
+ end
+ end
+
+ context 'when canonical URL points to the same host' do
+ let(:html) { '' }
+
+ it 'ignores the canonical URLs' do
+ expect(subject.canonical_url).to eq 'https://foo.com/article'
+ end
+ end
+ end
+end
diff --git a/spec/services/fetch_link_card_service_spec.rb b/spec/services/fetch_link_card_service_spec.rb
index 736a6078dd6..4914c275326 100644
--- a/spec/services/fetch_link_card_service_spec.rb
+++ b/spec/services/fetch_link_card_service_spec.rb
@@ -1,7 +1,7 @@
require 'rails_helper'
RSpec.describe FetchLinkCardService, type: :service do
- subject { FetchLinkCardService.new }
+ subject { described_class.new }
before do
stub_request(:get, 'http://example.xn--fiqs8s/').to_return(request_fixture('idn.txt'))