# File lib/action_dispatch/middleware/remote_ip.rb, line 35 def initialize(env, middleware) @env = env @middleware = middleware @calculated_ip = false end
Determines originating IP address. REMOTE_ADDR is the standard but will be wrong if the user is behind a proxy. Proxies will set HTTP_CLIENT_IP and/or HTTP_X_FORWARDED_FOR, so we prioritize those. HTTP_X_FORWARDED_FOR may be a comma-delimited list in the case of multiple chained proxies. The last address which is not a known proxy will be the originating IP.
# File lib/action_dispatch/middleware/remote_ip.rb, line 47 def calculate_ip client_ip = @env['HTTP_CLIENT_IP'] forwarded_ips = ips_from('HTTP_X_FORWARDED_FOR') remote_addrs = ips_from('REMOTE_ADDR') check_ip = client_ip && forwarded_ips.present? && @middleware.check_ip if check_ip && !forwarded_ips.include?(client_ip) # We don't know which came from the proxy, and which from the user raise IpSpoofAttackError, "IP spoofing attack?!" "HTTP_CLIENT_IP=#{@env['HTTP_CLIENT_IP'].inspect}" "HTTP_X_FORWARDED_FOR=#{@env['HTTP_X_FORWARDED_FOR'].inspect}" end not_proxy = client_ip || forwarded_ips.last || remote_addrs.first # Return first REMOTE_ADDR if there are no other options not_proxy || ips_from('REMOTE_ADDR', :allow_proxies).first end
# File lib/action_dispatch/middleware/remote_ip.rb, line 66 def to_s return @ip if @calculated_ip @calculated_ip = true @ip = calculate_ip end
# File lib/action_dispatch/middleware/remote_ip.rb, line 74 def ips_from(header, allow_proxies = false) ips = @env[header] ? @env[header].strip.split(/[,\s]+/) : [] allow_proxies ? ips : ips.reject{|ip| ip =~ @middleware.proxies } end