View Source RemoteIp.Parser behaviour (remote_ip v1.1.0)
Defines the interface for parsing headers into IP addresses.
RemoteIp.Headers.parse/1 dynamically dispatches to different parser modules
depending on the name of the header. For example, the "forwarded" header is
parsed by RemoteIp.Parsers.Forwarded, which implements this behaviour.
Link to this section Summary
Types
Any module that implements the RemoteIp.Parser behaviour.
Callbacks
Parses the specific header's value into a list of IP addresses.
Link to this section Types
@type t() :: module()
Any module that implements the RemoteIp.Parser behaviour.
Link to this section Callbacks
@callback parse(header :: binary()) :: [:inet.ip_address()]
Parses the specific header's value into a list of IP addresses.
This callback should be error-safe. For instance, if the header's value is invalid, it should return an empty list.
The actual work of converting an individual IP address string into the tuple
type should typically be done using :inet functions such as
:inet.parse_strict_address/1.
Note that a header may also contain more than one IP address. The order of
the list is important because it's interpreted as routing information.
Conceptually, the leftmost IP is the source of the request (the client), the
rightmost IP is the destination (your server), and anything in the middle
lists the proxy hops in order. However, in reality, there may be bad actors
or strange routing that makes this more complicated. It's the job of
RemoteIp to sort that out. This callback should only be concerned with
faithfully parsing the literal order given by the header.