FixAlchemy.Server.Logon (FIXAlchemy v0.3.0)

Matching an inbound Logon to one of an acceptor's configured sessions.

An acceptor learns who is calling from the Logon itself, so the first message on a new connection decides which session the connection becomes, or that it becomes none and is refused. establish/3 makes that decision and performs no IO, so it can be exercised on its own.

Comp ids are read from the initiator's point of view: the Logon's SenderCompID (49) is the session's :target_comp_id, and its TargetCompID (56) is the session's :sender_comp_id.

Session configuration

Each entry of sessions is a keyword list or map carrying at least :sender_comp_id and :target_comp_id. Everything else it holds is returned untouched in match.session, so a caller can put :connection_id, :handlers or any other per-session setting there.

Declaring :username and :password on a session requires the Logon to carry matching Username (553) and Password (554). Passing an :authenticate function in opts replaces that check for every session; it receives the session and the Logon's fields and returns :ok or {:error, text}.

Summary

Types

match()

session()

Functions

establish(fields, sessions, opts)

Decide whether a Logon may open a session.

Types

match()

@type match() :: %{
  session: session(),
  heartbeat_interval: pos_integer(),
  msg_seq_num: pos_integer(),
  reset_sequence?: boolean()
}

session()

@type session() :: keyword() | map()

Functions

establish(fields, sessions, opts)

@spec establish([{binary(), binary()}], [session()], keyword()) ::
  {:ok, match()} | {:reject, binary()}

Decide whether a Logon may open a session.

fields is the Logon as FixAlchemy.Parser.split_fields/1 returns it.

Options

:fix_version - the BeginString the acceptor speaks; when set, a Logon carrying any other is refused
:authenticate - a two-argument function replacing credential checking

Returns {:ok, match}, or {:reject, text} carrying the Text (58) to send in the refusing Logout.