Packages

erlang_ws

0.1.1
0.3.0 0.2.0 0.1.1 0.1.0

WebSocket protocol library for Erlang (RFC 6455 / RFC 8441 / RFC 9220)

HexDocs

Current section

Files

Jump to
Readme
4 Versions
0 Dependencies
Dependants
Files
Activity
erlang_ws src ws_close.erl
Raw

src/ws_close.erl 

%% Copyright 2026 Benoit Chesneau

%%

%% Licensed under the Apache License, Version 2.0 (the "License");

%% you may not use this file except in compliance with the License.

%% You may obtain a copy of the License at

%%

%%     http://www.apache.org/licenses/LICENSE-2.0

%%

%% Unless required by applicable law or agreed to in writing, software

%% distributed under the License is distributed on an "AS IS" BASIS,

%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

%% See the License for the specific language governing permissions and

%% limitations under the License.



%% @doc Close-code classification and validation (RFC 6455 §7.4).

%%

%% 1000..1003, 1007..1011 are defined.

%% 1004 is reserved; 1005, 1006, 1015 MUST NOT appear on the wire.

%% 3000..3999 are reserved for registration.

%% 4000..4999 are free for application use.

-module(ws_close).



-export([valid_on_wire/1]).

-export([reason_name/1]).



-include("../include/ws.hrl").



-type code() :: 1000..4999.

-export_type([code/0]).



%% @doc True if Code is allowed to appear in a close frame on the wire.

-spec valid_on_wire(integer()) -> boolean().

valid_on_wire(Code) when is_integer(Code) ->

    if

        Code < 1000 -> false;

        Code =:= 1004 -> false;

        Code =:= 1005 -> false;

        Code =:= 1006 -> false;

        Code =:= 1015 -> false;

        Code =< 1011 -> true;

        Code < 3000 -> false;

        Code =< 4999 -> true;

        true -> false

    end;

valid_on_wire(_) ->

    false.



%% @doc Human-readable label for a standard close code. Returns `undefined'

%% for application-range codes the library does not know about.

-spec reason_name(integer()) -> atom().

reason_name(?WS_CLOSE_NORMAL)          -> normal;

reason_name(?WS_CLOSE_GOING_AWAY)      -> going_away;

reason_name(?WS_CLOSE_PROTOCOL_ERROR)  -> protocol_error;

reason_name(?WS_CLOSE_UNSUPPORTED)     -> unsupported_data;

reason_name(?WS_CLOSE_NO_STATUS)       -> no_status;

reason_name(?WS_CLOSE_ABNORMAL)        -> abnormal;

reason_name(?WS_CLOSE_INVALID_UTF8)    -> invalid_utf8;

reason_name(?WS_CLOSE_POLICY)          -> policy_violation;

reason_name(?WS_CLOSE_TOO_BIG)         -> message_too_big;

reason_name(?WS_CLOSE_EXT_NEGOTIATION) -> extension_required;

reason_name(?WS_CLOSE_INTERNAL_ERROR)  -> internal_error;

reason_name(?WS_CLOSE_TLS_HANDSHAKE)   -> tls_handshake;

reason_name(_)                         -> undefined.