analytics/lib/plausible_web/remote_ip.ex
2022-01-15 08:57:25 -06:00

52 lines
1.6 KiB
Elixir

defmodule PlausibleWeb.RemoteIp do
def get(conn) do
cf_connecting_ip = List.first(Plug.Conn.get_req_header(conn, "cf-connecting-ip"))
x_forwarded_for = List.first(Plug.Conn.get_req_header(conn, "x-forwarded-for"))
b_forwarded_for = List.first(Plug.Conn.get_req_header(conn, "b-forwarded-for"))
forwarded = List.first(Plug.Conn.get_req_header(conn, "forwarded"))
cond do
cf_connecting_ip ->
clean_ip(cf_connecting_ip)
b_forwarded_for ->
parse_forwarded_for(b_forwarded_for)
x_forwarded_for ->
parse_forwarded_for(x_forwarded_for)
forwarded ->
Regex.named_captures(~r/for=(?<for>[^;,]+).*$/, forwarded)
|> Map.get("for")
# IPv6 addresses are enclosed in quote marks and square brackets: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Forwarded
|> String.trim("\"")
|> clean_ip
true ->
to_string(:inet_parse.ntoa(conn.remote_ip))
end
end
# Removes port from both IPv4 and IPv6 addresses. From https://regexr.com/3hpvt
# Removes surrounding [] of an IPv6 address
@port_regex ~r/((\.\d+)|(\]))(?<port>:[0-9]+)$/
defp clean_ip(ip_and_port) do
ip =
case Regex.named_captures(@port_regex, ip_and_port) do
%{"port" => port} -> String.trim_trailing(ip_and_port, port)
_ -> ip_and_port
end
ip
|> String.trim_leading("[")
|> String.trim_trailing("]")
end
defp parse_forwarded_for(header) do
String.split(header, ",")
|> Enum.map(&String.trim/1)
|> List.first()
|> clean_ip
end
end