discourse/lib/final_destination/http.rb

# frozen_string_literal: true

class FinalDestination::HTTP < Net::HTTP
  def connect
    original_open_timeout = @open_timeout
    return super if @ipaddr

    timeout_at = current_time + @open_timeout

    # This iteration through addresses would normally happen in Socket#tcp
    # We do it here because we're tightly controlling addresses rather than
    # handing Socket#tcp a hostname
    ips = FinalDestination::SSRFDetector.lookup_and_filter_ips(@address, timeout: @connect_timeout)

    ips.each_with_index do |ip, index|
      debug "[FinalDestination] Attempting connection to #{ip}..."
      self.ipaddr = ip

      remaining_time = timeout_at - current_time
      if remaining_time <= 0
        raise Net::OpenTimeout.new("Operation timed out - FinalDestination::HTTP")
      end

      @open_timeout = remaining_time
      return super
    rescue SystemCallError, Net::OpenTimeout => e
      debug "[FinalDestination] Error connecting to #{ip}... #{e.message}"
      was_last_attempt = index == ips.length - 1
      raise if was_last_attempt
    end
  ensure
    @open_timeout = original_open_timeout
  end

  private

  def current_time
    Process.clock_gettime(Process::CLOCK_MONOTONIC)
  end
end