mitigate SSL and emfile related conditions per #138
diff --git a/CHANGES.md b/CHANGES.md
index 673d759..19f96d1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,12 @@
+Version 2.11.0 released 2015-01-12
+
+* Perform SSL handshake after releasing acceptor back into the pool,
+ and slow accept rate when file descriptors are not available,
+ to mitigate a potential DoS attack. Adds new mochiweb_socket
+ functions transport_accept/1 and finish_accept/1 which should be
+ used in preference to the now deprecated accept/1 function.
+ https://github.com/mochi/mochiweb/issues/138
+
Version 2.10.1 released 2015-01-11
* Fixes issue with SSL and mochiweb_websocket. Note that
diff --git a/src/mochiweb.app.src b/src/mochiweb.app.src
index ccad5bc..4754266 100644
--- a/src/mochiweb.app.src
+++ b/src/mochiweb.app.src
@@ -1,7 +1,7 @@
%% This is generated from src/mochiweb.app.src
{application, mochiweb,
[{description, "MochiMedia Web Server"},
- {vsn, "2.10.1"},
+ {vsn, "2.11.0"},
{modules, []},
{registered, []},
{env, []},
diff --git a/src/mochiweb_acceptor.erl b/src/mochiweb_acceptor.erl
index 208f861..8a58fcf 100644
--- a/src/mochiweb_acceptor.erl
+++ b/src/mochiweb_acceptor.erl
@@ -10,25 +10,44 @@
-export([start_link/3, start_link/4, init/4]).
+-define(EMFILE_SLEEP_MSEC, 100).
+
start_link(Server, Listen, Loop) ->
start_link(Server, Listen, Loop, []).
start_link(Server, Listen, Loop, Opts) ->
proc_lib:spawn_link(?MODULE, init, [Server, Listen, Loop, Opts]).
-init(Server, Listen, Loop, Opts) ->
+do_accept(Server, Listen) ->
T1 = os:timestamp(),
- case catch mochiweb_socket:accept(Listen) of
+ case mochiweb_socket:transport_accept(Listen) of
{ok, Socket} ->
gen_server:cast(Server, {accepted, self(), timer:now_diff(os:timestamp(), T1)}),
+ mochiweb_socket:finish_accept(Socket);
+ Other ->
+ Other
+ end.
+
+init(Server, Listen, Loop, Opts) ->
+ case catch do_accept(Server, Listen) of
+ {ok, Socket} ->
call_loop(Loop, Socket, Opts);
- {error, closed} ->
- exit(normal);
- {error, timeout} ->
- init(Server, Listen, Loop, Opts);
- {error, esslaccept} ->
+ {error, Err} when Err =:= closed orelse
+ Err =:= esslaccept orelse
+ Err =:= timeout ->
exit(normal);
Other ->
+ %% Mitigate out of file descriptor scenario by sleeping for a
+ %% short time to slow error rate
+ case Other of
+ {error, emfile} ->
+ receive
+ after ?EMFILE_SLEEP_MSEC ->
+ ok
+ end;
+ _ ->
+ ok
+ end,
error_logger:error_report(
[{application, mochiweb},
"Accept failed error",
@@ -44,10 +63,3 @@
erlang:apply(M, F, [Socket, Opts | A]);
call_loop(Loop, Socket, Opts) ->
Loop(Socket, Opts).
-
-%%
-%% Tests
-%%
--ifdef(TEST).
--include_lib("eunit/include/eunit.hrl").
--endif.
diff --git a/src/mochiweb_socket.erl b/src/mochiweb_socket.erl
index f4b8bfb..1e35e15 100644
--- a/src/mochiweb_socket.erl
+++ b/src/mochiweb_socket.erl
@@ -4,7 +4,9 @@
-module(mochiweb_socket).
--export([listen/4, accept/1, recv/3, send/2, close/1, port/1, peername/1,
+-export([listen/4,
+ accept/1, transport_accept/1, finish_accept/1,
+ recv/3, send/2, close/1, port/1, peername/1,
setopts/2, getopts/2, type/1]).
-define(ACCEPT_TIMEOUT, 2000).
@@ -66,27 +68,35 @@
end,
Versions).
-
-accept({ssl, ListenSocket}) ->
- % There's a bug in ssl:transport_accept/2 at the moment, which is the
- % reason for the try...catch block. Should be fixed in OTP R14.
- try ssl:transport_accept(ListenSocket, ?SSL_TIMEOUT) of
+%% Provided for backwards compatibility only
+accept(ListenSocket) ->
+ case transport_accept(ListenSocket) of
{ok, Socket} ->
- case ssl:ssl_accept(Socket, ?SSL_HANDSHAKE_TIMEOUT) of
- ok ->
- {ok, {ssl, Socket}};
- {error, _} = Err ->
- Err
- end;
+ finish_accept(Socket);
{error, _} = Err ->
Err
- catch
- error:{badmatch, {error, Reason}} ->
- {error, Reason}
+ end.
+
+transport_accept({ssl, ListenSocket}) ->
+ case ssl:transport_accept(ListenSocket, ?SSL_TIMEOUT) of
+ {ok, Socket} ->
+ {ok, {ssl, Socket}};
+ {error, _} = Err ->
+ Err
end;
-accept(ListenSocket) ->
+transport_accept(ListenSocket) ->
gen_tcp:accept(ListenSocket, ?ACCEPT_TIMEOUT).
+finish_accept({ssl, Socket}) ->
+ case ssl:ssl_accept(Socket, ?SSL_HANDSHAKE_TIMEOUT) of
+ ok ->
+ {ok, {ssl, Socket}};
+ {error, _} = Err ->
+ Err
+ end;
+finish_accept(Socket) ->
+ {ok, Socket}.
+
recv({ssl, Socket}, Length, Timeout) ->
ssl:recv(Socket, Length, Timeout);
recv(Socket, Length, Timeout) ->
