discourse/lib/oneboxer.rb
jbrw da9b837da0
DEV: More robust processing of URLs (#11361)
* DEV: More robust processing of URLs

The previous `UrlHelper.encode_component(CGI.unescapeHTML(UrlHelper.unencode(uri))` method would naively process URLs, which could result in a badly formed response.

`Addressable::URI.normalized_encode(uri)` appears to deal with these edge-cases in a more robust way.

* DEV: onebox should use UrlHelper

* DEV: fix spec

* DEV: Escape output when rendering local links
2020-12-03 17:16:01 -05:00

416 lines
13 KiB
Ruby

# frozen_string_literal: true
require 'uri'
Dir["#{Rails.root}/lib/onebox/engine/*_onebox.rb"].sort.each { |f| require f }
module Oneboxer
ONEBOX_CSS_CLASS = "onebox"
AUDIO_REGEX = /^\.(mp3|og[ga]|opus|wav|m4[abpr]|aac|flac)$/i
VIDEO_REGEX = /^\.(mov|mp4|webm|m4v|3gp|ogv|avi|mpeg|ogv)$/i
# keep reloaders happy
unless defined? Oneboxer::Result
Result = Struct.new(:doc, :changed) do
def to_html
doc.to_html
end
def changed?
changed
end
end
end
def self.ignore_redirects
@ignore_redirects ||= ['http://www.dropbox.com', 'http://store.steampowered.com', 'http://vimeo.com', Discourse.base_url]
end
def self.force_get_hosts
@force_get_hosts ||= ['http://us.battle.net', 'https://news.yahoo.com/']
end
def self.force_custom_user_agent_hosts
SiteSetting.force_custom_user_agent_hosts.split('|')
end
def self.allowed_post_types
@allowed_post_types ||= [Post.types[:regular], Post.types[:moderator_action]]
end
def self.preview(url, options = nil)
options ||= {}
invalidate(url) if options[:invalidate_oneboxes]
onebox_raw(url, options)[:preview]
end
def self.onebox(url, options = nil)
options ||= {}
invalidate(url) if options[:invalidate_oneboxes]
onebox_raw(url, options)[:onebox]
end
def self.cached_onebox(url)
if c = Discourse.cache.read(onebox_cache_key(url))
c[:onebox]
end
rescue => e
invalidate(url)
Rails.logger.warn("invalid cached onebox for #{url} #{e}")
""
end
def self.cached_preview(url)
if c = Discourse.cache.read(onebox_cache_key(url))
c[:preview]
end
rescue => e
invalidate(url)
Rails.logger.warn("invalid cached preview for #{url} #{e}")
""
end
def self.invalidate(url)
Discourse.cache.delete(onebox_cache_key(url))
Discourse.cache.delete(onebox_failed_cache_key(url))
end
# Parse URLs out of HTML, returning the document when finished.
def self.each_onebox_link(string_or_doc, extra_paths: [])
doc = string_or_doc
doc = Nokogiri::HTML5::fragment(doc) if doc.is_a?(String)
onebox_links = doc.css("a.#{ONEBOX_CSS_CLASS}", *extra_paths)
if onebox_links.present?
onebox_links.each do |link|
yield(link['href'], link) if link['href'].present?
end
end
doc
end
HTML5_BLOCK_ELEMENTS ||= %w{address article aside blockquote canvas center dd div dl dt fieldset figcaption figure footer form h1 h2 h3 h4 h5 h6 header hgroup hr li main nav noscript ol output p pre section table tfoot ul video}
def self.apply(string_or_doc, extra_paths: nil)
doc = string_or_doc
doc = Nokogiri::HTML5::fragment(doc) if doc.is_a?(String)
changed = false
each_onebox_link(doc, extra_paths: extra_paths) do |url, element|
onebox, _ = yield(url, element)
if onebox
parsed_onebox = Nokogiri::HTML5::fragment(onebox)
next unless parsed_onebox.children.count > 0
if element&.parent&.node_name&.downcase == "p" &&
element.parent.children.count == 1 &&
HTML5_BLOCK_ELEMENTS.include?(parsed_onebox.children[0].node_name.downcase)
element = element.parent
end
changed = true
element.swap parsed_onebox.to_html
end
end
# strip empty <p> elements
doc.css("p").each do |p|
if p.children.empty? && doc.children.count > 1
p.remove
end
end
Result.new(doc, changed)
end
def self.is_previewing?(user_id)
Discourse.redis.get(preview_key(user_id)) == "1"
end
def self.preview_onebox!(user_id)
Discourse.redis.setex(preview_key(user_id), 1.minute, "1")
end
def self.onebox_previewed!(user_id)
Discourse.redis.del(preview_key(user_id))
end
def self.engine(url)
Onebox::Matcher.new(url, {
allowed_iframe_regexes: Onebox::Engine.origins_to_regexes(allowed_iframe_origins)
}).oneboxed
end
def self.recently_failed?(url)
Discourse.cache.read(onebox_failed_cache_key(url)).present?
end
def self.cache_failed!(url)
Discourse.cache.write(onebox_failed_cache_key(url), true, expires_in: 1.hour)
end
private
def self.preview_key(user_id)
"onebox:preview:#{user_id}"
end
def self.blank_onebox
{ preview: "", onebox: "" }
end
def self.onebox_cache_key(url)
"onebox__#{url}"
end
def self.onebox_failed_cache_key(url)
"onebox_failed__#{url}"
end
def self.onebox_raw(url, opts = {})
url = UrlHelper.escape_uri(url).to_s
local_onebox(url, opts) || external_onebox(url)
rescue => e
# no point warning here, just cause we have an issue oneboxing a url
# we can later hunt for failed oneboxes by searching logs if needed
Rails.logger.info("Failed to onebox #{url} #{e} #{e.backtrace}")
# return a blank hash, so rest of the code works
blank_onebox
end
def self.local_onebox(url, opts = {})
return unless route = Discourse.route_for(url)
html =
case route[:controller]
when "uploads" then local_upload_html(url)
when "topics" then local_topic_html(url, route, opts)
when "users" then local_user_html(url, route)
when "list" then local_category_html(url, route)
end
html = html.presence || "<a href='#{URI(url).to_s}'>#{URI(url).to_s}</a>"
{ onebox: html, preview: html }
end
def self.local_upload_html(url)
case File.extname(URI(url).path || "")
when VIDEO_REGEX
<<~HTML
<div class="onebox video-onebox">
<video width="100%" height="100%" controls="">
<source src='#{url}'>
<a href='#{url}'>#{url}</a>
</video>
</div>
HTML
when AUDIO_REGEX
"<audio controls><source src='#{url}'><a href='#{url}'>#{url}</a></audio>"
end
end
def self.local_topic(url, route, opts)
if current_user = User.find_by(id: opts[:user_id])
if current_category = Category.find_by(id: opts[:category_id])
return unless Guardian.new(current_user).can_see_category?(current_category)
end
if current_topic = Topic.find_by(id: opts[:topic_id])
return unless Guardian.new(current_user).can_see_topic?(current_topic)
end
end
return unless topic = Topic.find_by(id: route[:id] || route[:topic_id])
return if topic.private_message?
if current_category.blank? || current_category.id != topic.category_id
return unless Guardian.new.can_see_topic?(topic)
end
topic
end
def self.local_topic_html(url, route, opts)
return unless topic = local_topic(url, route, opts)
post_number = route[:post_number].to_i
post = post_number > 1 ?
topic.posts.where(post_number: post_number).first :
topic.ordered_posts.first
return if !post || post.hidden || !allowed_post_types.include?(post.post_type)
if post_number > 1 && opts[:topic_id] == topic.id
excerpt = post.excerpt(SiteSetting.post_onebox_maxlength)
excerpt.gsub!(/[\r\n]+/, " ")
excerpt.gsub!("[/quote]", "[quote]") # don't break my quote
quote = "[quote=\"#{post.user.username}, topic:#{topic.id}, post:#{post.post_number}\"]\n#{excerpt}\n[/quote]"
PrettyText.cook(quote)
else
args = {
topic_id: topic.id,
post_number: post.post_number,
avatar: PrettyText.avatar_img(post.user.avatar_template, "tiny"),
original_url: url,
title: PrettyText.unescape_emoji(CGI::escapeHTML(topic.title)),
category_html: CategoryBadge.html_for(topic.category),
quote: PrettyText.unescape_emoji(post.excerpt(SiteSetting.post_onebox_maxlength)),
}
template = template("discourse_topic_onebox")
Mustache.render(template, args)
end
end
def self.local_user_html(url, route)
username = route[:username] || ""
if user = User.find_by(username_lower: username.downcase)
name = user.name if SiteSetting.enable_names
args = {
user_id: user.id,
username: user.username,
avatar: PrettyText.avatar_img(user.avatar_template, "extra_large"),
name: name,
bio: user.user_profile.bio_excerpt(230),
location: Onebox::Helpers.sanitize(user.user_profile.location),
joined: I18n.t('joined'),
created_at: user.created_at.strftime(I18n.t('datetime_formats.formats.date_only')),
website: user.user_profile.website,
website_name: UserSerializer.new(user).website_name,
original_url: url
}
Mustache.render(template("discourse_user_onebox"), args)
else
nil
end
end
def self.local_category_html(url, route)
return unless route[:category_slug_path_with_id]
category = Category.find_by_slug_path_with_id(route[:category_slug_path_with_id])
if Guardian.new.can_see_category?(category)
args = {
url: category.url,
name: category.name,
color: category.color,
logo_url: category.uploaded_logo&.url,
description: category.description,
has_subcategories: category.subcategories.present?,
subcategories: category.subcategories.collect { |sc| { name: sc.name, color: sc.color, url: sc.url } }
}
Mustache.render(template("discourse_category_onebox"), args)
end
end
def self.blocked_domains
SiteSetting.blocked_onebox_domains.split("|")
end
def self.preserve_fragment_url_hosts
@preserve_fragment_url_hosts ||= ['http://github.com']
end
def self.allowed_iframe_origins
allowed = SiteSetting.allowed_onebox_iframes.split("|")
if allowed.include?("*")
allowed = Onebox::Engine.all_iframe_origins
end
allowed += SiteSetting.allowed_iframes.split("|")
end
def self.external_onebox(url)
Discourse.cache.fetch(onebox_cache_key(url), expires_in: 1.day) do
fd = FinalDestination.new(url,
ignore_redirects: ignore_redirects,
ignore_hostnames: blocked_domains,
force_get_hosts: force_get_hosts,
force_custom_user_agent_hosts: force_custom_user_agent_hosts,
preserve_fragment_url_hosts: preserve_fragment_url_hosts)
uri = fd.resolve
if fd.status != :resolved
args = { link: url }
if fd.status == :invalid_address
args[:error_message] = I18n.t("errors.onebox.invalid_address", hostname: fd.hostname)
elsif fd.status_code
args[:error_message] = I18n.t("errors.onebox.error_response", status_code: fd.status_code)
end
error_box = blank_onebox
error_box[:preview] = preview_error_onebox(args)
return error_box
end
return blank_onebox if uri.blank? || blocked_domains.map { |hostname| uri.hostname.match?(hostname) }.any?
options = {
max_width: 695,
sanitize_config: Onebox::DiscourseOneboxSanitizeConfig::Config::DISCOURSE_ONEBOX,
allowed_iframe_origins: allowed_iframe_origins,
hostname: GlobalSetting.hostname,
facebook_app_access_token: SiteSetting.facebook_app_access_token,
}
options[:cookie] = fd.cookie if fd.cookie
r = Onebox.preview(uri.to_s, options)
result = { onebox: r.to_s, preview: r&.placeholder_html.to_s }
# NOTE: Call r.errors after calling placeholder_html
if r.errors.any?
missing_attributes = r.errors.keys.map(&:to_s).sort.join(I18n.t("word_connector.comma"))
error_message = I18n.t("errors.onebox.missing_data", missing_attributes: missing_attributes, count: r.errors.keys.size)
args = r.data.merge(error_message: error_message)
if result[:preview].blank?
result[:preview] = preview_error_onebox(args)
else
doc = Nokogiri::HTML5::fragment(result[:preview])
aside = doc.at('aside')
if aside
# Add an error message to the preview that was returned
error_fragment = preview_error_onebox_fragment(args)
aside.add_child(error_fragment)
result[:preview] = doc.to_html
end
end
end
result
end
end
def self.preview_error_onebox(args, is_fragment = false)
args[:title] ||= args[:link] if args[:link]
args[:error_message] = PrettyText.unescape_emoji(args[:error_message]) if args[:error_message]
template_name = is_fragment ? "preview_error_fragment_onebox" : "preview_error_onebox"
Mustache.render(template(template_name), args)
end
def self.preview_error_onebox_fragment(args)
preview_error_onebox(args, true)
end
def self.template(template_name)
@template_cache ||= {}
@template_cache[template_name] ||= begin
full_path = "#{Rails.root}/lib/onebox/templates/#{template_name}.mustache"
File.read(full_path)
end
end
end