discourse/app/models/embeddable_host.rb

# frozen_string_literal: true

class EmbeddableHost < ActiveRecord::Base
  validate :host_must_be_valid
  belongs_to :category
  after_destroy :reset_embedding_settings

  before_validation do
    self.host.sub!(/^https?:\/\//, '')
    self.host.sub!(/\/.*$/, '')
  end

  # TODO(2021-07-23): Remove
  self.ignored_columns = ["path_whitelist"]

  def self.record_for_url(uri)
    if uri.is_a?(String)
      uri = begin
        URI(UrlHelper.escape_uri(uri))
      rescue URI::Error, Addressable::URI::InvalidURIError
      end
    end

    return false unless uri.present?

    host = uri.host
    return false unless host.present?

    if uri.port.present? && uri.port != 80 && uri.port != 443
      host << ":#{uri.port}"
    end

    path = uri.path
    path << "?" << uri.query if uri.query.present?

    where("lower(host) = ?", host).each do |eh|
      return eh if eh.allowed_paths.blank?

      path_regexp = Regexp.new(eh.allowed_paths)
      return eh if path_regexp.match(path) || path_regexp.match(UrlHelper.unencode(path))
    end

    nil
  end

  def self.url_allowed?(url)
    return false if url.nil?

    # Work around IFRAME reload on WebKit where the referer will be set to the Forum URL
    return true if url&.starts_with?(Discourse.base_url) && EmbeddableHost.exists?

    uri = begin
      URI(UrlHelper.escape_uri(url))
    rescue URI::Error
    end

    uri.present? && record_for_url(uri).present?
  end

  private

  def reset_embedding_settings
    unless EmbeddableHost.exists?
      Embedding.settings.each { |s| SiteSetting.set(s.to_s, SiteSetting.defaults[s]) }
    end
  end

  def host_must_be_valid
    if host !~ /\A[a-z0-9]+([\-\.]+{1}[a-z0-9]+)*\.[a-z]{2,24}(:[0-9]{1,5})?(\/.*)?\Z/i &&
       host !~ /\A(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})(:[0-9]{1,5})?(\/.*)?\Z/ &&
       host !~ /\A([a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.)?localhost(\:[0-9]{1,5})?(\/.*)?\Z/i
      errors.add(:host, I18n.t('errors.messages.invalid'))
    end
  end
end

# == Schema Information
#
# Table name: embeddable_hosts
#
#  id            :integer          not null, primary key
#  host          :string           not null
#  category_id   :integer          not null
#  created_at    :datetime         not null
#  updated_at    :datetime         not null
#  class_name    :string
#  allowed_paths :string
#