Improve robustness of external authentication backends

Now all external ports are attached to supervising processes
and requests are balanced in round-robin manner until the pool
is exhausted.

The commit also deprecates `extauth_instances` option and introduces
`extauth_pool_size` option instead, with the default value of a number
of logical processors (i.e. CPU cores).

Fixes #2403
This commit is contained in:
Evgeniy Khramtsov 2018-05-07 19:27:18 +03:00
parent b1a03cc346
commit b23d5754e8
4 changed files with 338 additions and 136 deletions

View File

@ -69,6 +69,7 @@
-callback start(binary()) -> any().
-callback stop(binary()) -> any().
-callback reload(binary()) -> any().
-callback plain_password_required(binary()) -> boolean().
-callback store_type(binary()) -> plain | external | scram.
-callback set_password(binary(), binary(), binary()) -> ok | {error, atom()}.
@ -82,7 +83,8 @@
-callback use_cache(binary()) -> boolean().
-callback cache_nodes(binary()) -> boolean().
-optional_callbacks([set_password/3,
-optional_callbacks([reload/1,
set_password/3,
remove_user/2,
user_exists/2,
check_password/4,
@ -130,14 +132,16 @@ handle_cast({host_down, Host}, #state{host_modules = HostModules} = State) ->
init_cache(NewHostModules),
{noreply, State#state{host_modules = NewHostModules}};
handle_cast(config_reloaded, #state{host_modules = HostModules} = State) ->
NewHostModules = lists:foldl(
fun(Host, Acc) ->
OldModules = maps:get(Host, HostModules, []),
NewModules = auth_modules(Host),
start(Host, NewModules -- OldModules),
stop(Host, OldModules -- NewModules),
maps:put(Host, NewModules, Acc)
end, HostModules, ?MYHOSTS),
NewHostModules =
lists:foldl(
fun(Host, Acc) ->
OldModules = maps:get(Host, HostModules, []),
NewModules = auth_modules(Host),
start(Host, NewModules -- OldModules),
stop(Host, OldModules -- NewModules),
reload(Host, lists_intersection(OldModules, NewModules)),
maps:put(Host, NewModules, Acc)
end, HostModules, ?MYHOSTS),
init_cache(NewHostModules),
{noreply, State#state{host_modules = NewHostModules}};
handle_cast(Msg, State) ->
@ -165,6 +169,15 @@ start(Host, Modules) ->
stop(Host, Modules) ->
lists:foreach(fun(M) -> M:stop(Host) end, Modules).
reload(Host, Modules) ->
lists:foreach(
fun(M) ->
case erlang:function_exported(M, reload, 1) of
true -> M:reload(Host);
false -> ok
end
end, Modules).
host_up(Host) ->
gen_server:cast(?MODULE, {host_up, Host}).
@ -559,7 +572,9 @@ db_user_exists(User, Server, Mod) ->
{ok, _} ->
true;
error ->
false
false;
{error, _} = Err ->
Err
end;
{external, false} ->
Mod:user_exists(User, Server);
@ -816,6 +831,12 @@ validate_credentials(User, Server, Password) ->
end
end.
lists_intersection(L1, L2) ->
lists:filter(
fun(E) ->
lists:member(E, L2)
end, L1).
import_info() ->
[{<<"users">>, 3}].

View File

@ -31,7 +31,7 @@
-behaviour(ejabberd_auth).
-export([start/1, stop/1, set_password/3, check_password/4,
-export([start/1, stop/1, reload/1, set_password/3, check_password/4,
try_register/3, user_exists/2, remove_user/2,
store_type/1, plain_password_required/1, opt_type/1]).
@ -42,12 +42,14 @@
%%% API
%%%----------------------------------------------------------------------
start(Host) ->
Cmd = ejabberd_config:get_option({extauth_program, Host}, "extauth"),
extauth:start(Host, Cmd).
extauth:start(Host).
stop(Host) ->
extauth:stop(Host).
reload(Host) ->
extauth:reload(Host).
plain_password_required(_) -> true.
store_type(_) -> external.
@ -61,37 +63,47 @@ check_password(User, AuthzId, Server, Password) ->
set_password(User, Server, Password) ->
case extauth:set_password(User, Server, Password) of
true -> ok;
_ -> {error, db_failure}
Res when is_boolean(Res) -> ok;
{error, Reason} -> failure(Reason)
end.
try_register(User, Server, Password) ->
extauth:try_register(User, Server, Password).
case extauth:try_register(User, Server, Password) of
true -> ok;
false -> {error, not_allowed};
{error, Reason} -> failure(Reason)
end.
user_exists(User, Server) ->
try extauth:user_exists(User, Server) of
Res -> Res
catch
_:Error ->
?ERROR_MSG("external authentication program failure: ~p",
[Error]),
{error, db_failure}
case extauth:user_exists(User, Server) of
Res when is_boolean(Res) -> Res;
{error, Reason} -> failure(Reason)
end.
remove_user(User, Server) ->
case extauth:remove_user(User, Server) of
false -> {error, not_allowed};
true -> ok
true -> ok;
{error, Reason} -> failure(Reason)
end.
check_password_extauth(User, _AuthzId, Server, Password) ->
extauth:check_password(User, Server, Password) andalso
Password /= <<"">>.
if Password /= <<"">> ->
case extauth:check_password(User, Server, Password) of
Res when is_boolean(Res) -> Res;
{error, Reason} ->
failure(Reason),
false
end;
true ->
false
end.
-spec failure(any()) -> {error, db_failure}.
failure(Reason) ->
?ERROR_MSG("External authentication program failure: ~p", [Reason]),
{error, db_failure}.
-spec opt_type(extauth_cache) -> fun((false | non_neg_integer()) ->
false | non_neg_integer());
(extauth_program) -> fun((binary()) -> string());
(atom()) -> [atom()].
opt_type(extauth_cache) ->
?WARNING_MSG("option 'extauth_cache' is deprecated and has no effect, "
"use authentication or global cache configuration "
@ -100,6 +112,15 @@ opt_type(extauth_cache) ->
fun (false) -> false;
(I) when is_integer(I), I >= 0 -> I
end;
opt_type(extauth_instances) ->
?WARNING_MSG("option 'extauth_instances' is deprecated and has no effect, "
"use 'extauth_pool_size'", []),
fun (V) when is_integer(V), V > 0 -> V end;
opt_type(extauth_program) ->
fun (V) -> binary_to_list(iolist_to_binary(V)) end;
opt_type(_) -> [extauth_cache, extauth_program].
opt_type(extauth_pool_size) ->
fun(I) when is_integer(I), I>0 -> I end;
opt_type(_) ->
[extauth_program, extauth_pool_size,
%% Deprecated:
extauth_cache, extauth_instances].

View File

@ -1,8 +1,5 @@
%%%----------------------------------------------------------------------
%%% File : extauth.erl
%%% Author : Leif Johansson <leifj@it.su.se>
%%% Purpose : External authentication using a simple port-driver
%%% Created : 30 Jul 2004 by Leif Johansson <leifj@it.su.se>
%%%-------------------------------------------------------------------
%%% Created : 7 May 2018 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2018 ProcessOne
@ -21,54 +18,45 @@
%%% with this program; if not, write to the Free Software Foundation, Inc.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%----------------------------------------------------------------------
%%%-------------------------------------------------------------------
-module(extauth).
-behaviour(ejabberd_config).
-ifndef(GEN_SERVER).
-define(GEN_SERVER, gen_server).
-endif.
-behaviour(?GEN_SERVER).
-author('leifj@it.su.se').
-define(CALL_TIMEOUT, timer:seconds(30)).
-export([start/2, stop/1, init/2, check_password/3,
set_password/3, try_register/3, remove_user/2,
remove_user/3, user_exists/2, opt_type/1]).
%% API
-export([start/1, stop/1, reload/1, start_link/2]).
-export([check_password/3, set_password/3, try_register/3, remove_user/2,
remove_user/3, user_exists/2]).
-export([prog_name/1, pool_name/1, worker_name/2, pool_size/1]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-include("ejabberd.hrl").
-include("logger.hrl").
-define(INIT_TIMEOUT, 60000).
-record(state, {port :: port(),
prog :: string(),
start_time :: integer(),
os_pid :: integer() | undefined}).
-define(CALL_TIMEOUT, 10000).
start(Host, ExtPrg) ->
lists:foreach(fun (This) ->
start_instance(get_process_name(Host, This), ExtPrg)
end,
lists:seq(0, get_instances(Host) - 1)).
start_instance(ProcessName, ExtPrg) ->
spawn(?MODULE, init, [ProcessName, ExtPrg]).
restart_instance(ProcessName, ExtPrg) ->
unregister(ProcessName),
start_instance(ProcessName, ExtPrg).
init(ProcessName, ExtPrg) ->
register(ProcessName, self()),
process_flag(trap_exit, true),
Port = open_port({spawn, ExtPrg}, [{packet, 2}]),
loop(Port, ?INIT_TIMEOUT, ProcessName, ExtPrg).
%%%===================================================================
%%% API
%%%===================================================================
start(Host) ->
extauth_sup:start(Host).
stop(Host) ->
lists:foreach(fun (This) ->
get_process_name(Host, This) ! stop
end,
lists:seq(0, get_instances(Host) - 1)).
extauth_sup:stop(Host).
get_process_name(Host, Integer) ->
gen_mod:get_module_proc(iolist_to_binary([Host,
integer_to_list(Integer)]),
eauth).
reload(Host) ->
extauth_sup:reload(Host).
start_link(Name, Prog) ->
?GEN_SERVER:start_link({local, Name}, ?MODULE, [Prog], []).
check_password(User, Server, Password) ->
call_port(Server, [<<"auth">>, User, Server, Password]).
@ -80,82 +68,144 @@ set_password(User, Server, Password) ->
call_port(Server, [<<"setpass">>, User, Server, Password]).
try_register(User, Server, Password) ->
case call_port(Server,
[<<"tryregister">>, User, Server, Password])
of
true -> ok;
false -> {error, not_allowed}
end.
call_port(Server, [<<"tryregister">>, User, Server, Password]).
remove_user(User, Server) ->
call_port(Server, [<<"removeuser">>, User, Server]).
remove_user(User, Server, Password) ->
call_port(Server,
[<<"removeuser3">>, User, Server, Password]).
call_port(Server, [<<"removeuser3">>, User, Server, Password]).
call_port(Server, Msg) ->
LServer = jid:nameprep(Server),
ProcessName = get_process_name(LServer,
random_instance(get_instances(LServer))),
ProcessName ! {call, self(), Msg},
receive {eauth, Result} -> Result end.
-spec prog_name(binary()) -> string() | undefined.
prog_name(Host) ->
ejabberd_config:get_option({extauth_program, Host}).
random_instance(MaxNum) ->
randoms:uniform(MaxNum) - 1.
-spec pool_name(binary()) -> atom().
pool_name(Host) ->
list_to_atom("extauth_pool_" ++ binary_to_list(Host)).
get_instances(Server) ->
ejabberd_config:get_option({extauth_instances, Server}, 1).
-spec worker_name(atom(), integer()) -> atom().
worker_name(Pool, N) ->
list_to_atom(atom_to_list(Pool) ++ "_" ++ integer_to_list(N)).
loop(Port, Timeout, ProcessName, ExtPrg) ->
receive
{call, Caller, Msg} ->
port_command(Port, encode(Msg)),
receive
{Port, {data, Data}} ->
?DEBUG("extauth call '~p' received data response:~n~p",
[Msg, Data]),
Caller ! {eauth, decode(Data)},
loop(Port, ?CALL_TIMEOUT, ProcessName, ExtPrg);
{Port, Other} ->
?ERROR_MSG("extauth call '~p' received strange response:~n~p",
[Msg, Other]),
Caller ! {eauth, false},
loop(Port, ?CALL_TIMEOUT, ProcessName, ExtPrg)
-spec pool_size(binary()) -> pos_integer().
pool_size(Host) ->
case ejabberd_config:get_option({extauth_pool_size, Host}) of
undefined ->
try erlang:system_info(logical_processors)
catch _:_ -> 1
end;
Size ->
Size
end.
%%%===================================================================
%%% gen_server callbacks
%%%===================================================================
init([Prog]) ->
process_flag(trap_exit, true),
{Port, OSPid} = start_port(Prog),
Time = curr_time(),
{ok, #state{port = Port, start_time = Time,
prog = Prog, os_pid = OSPid}}.
handle_call({cmd, Cmd, EndTime}, _From, State) ->
Timeout = EndTime - curr_time(),
if Timeout > 0 ->
Port = State#state.port,
port_command(Port, Cmd),
receive
{Port, {data, [0, N] = Data}} when N == 0; N == 1 ->
?DEBUG("Received response from external authentication "
"program: ~p", [Data]),
{reply, decode_bool(N), State};
{Port, Data} ->
?ERROR_MSG("Received unexpected response from external "
"authentication program '~s': ~p "
"(port = ~p, pid = ~w)",
[State#state.prog, Data, Port, State#state.os_pid]),
{reply, {error, unexpected_response}, State};
{'EXIT', Port, Reason} ->
handle_info({'EXIT', Port, Reason}, State)
after Timeout ->
?ERROR_MSG("extauth call '~p' didn't receive response",
[Msg]),
Caller ! {eauth, false},
Pid = restart_instance(ProcessName, ExtPrg),
flush_buffer_and_forward_messages(Pid),
exit(port_terminated)
end;
stop ->
Port ! {self(), close},
receive {Port, closed} -> exit(normal) end;
{'EXIT', Port, Reason} ->
?CRITICAL_MSG("extauth script has exitted abruptly "
"with reason '~p'",
[Reason]),
Pid = restart_instance(ProcessName, ExtPrg),
flush_buffer_and_forward_messages(Pid),
exit(port_terminated)
{stop, extauth_program_timeout, State}
end;
true ->
{stop, extauth_program_timeout, State}
end.
flush_buffer_and_forward_messages(Pid) ->
receive
Message ->
Pid ! Message, flush_buffer_and_forward_messages(Pid)
after 0 -> true
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({'EXIT', Port, _Reason}, #state{port = Port,
start_time = Time} = State) ->
case curr_time() - Time of
Diff when Diff < 1000 ->
?ERROR_MSG("Failed to start external authentication program '~s'",
[State#state.prog]),
{stop, normal, State};
_ ->
?ERROR_MSG("External authentication program '~s' has terminated "
"unexpectedly (pid=~w), restarting via supervisor...",
[State#state.prog, State#state.os_pid]),
{stop, extauth_program_failure, State}
end;
handle_info(Info, State) ->
?WARNING_MSG("Unexpected info: ~p", [Info]),
{noreply, State}.
terminate(_Reason, State) ->
catch port_close(State#state.port),
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%%===================================================================
%%% Internal functions
%%%===================================================================
-spec curr_time() -> non_neg_integer().
curr_time() ->
p1_time_compat:monotonic_time(milli_seconds).
-spec start_port(string()) -> {port(), integer() | undefined}.
start_port(Path) ->
Port = open_port({spawn, Path}, [{packet, 2}]),
link(Port),
case erlang:port_info(Port, os_pid) of
{os_pid, OSPid} ->
{Port, OSPid};
undefined ->
{Port, undefined}
end.
encode(L) -> str:join(L, <<":">>).
call_port(Server, Args) ->
call_port(Server, Args, ?CALL_TIMEOUT).
decode([0, 0]) -> false;
decode([0, 1]) -> true.
call_port(Server, Args, Timeout) ->
StartTime = p1_time_compat:monotonic_time(milli_seconds),
Pool = pool_name(Server),
PoolSize = pool_size(Server),
I = randoms:round_robin(PoolSize),
Cmd = str:join(Args, <<":">>),
do_call(Cmd, I, I + PoolSize, Pool, PoolSize,
StartTime + Timeout, StartTime).
-spec opt_type(extauth_instances) -> fun((pos_integer()) -> pos_integer());
(atom()) -> [atom()].
opt_type(extauth_instances) ->
fun (V) when is_integer(V), V > 0 -> V end;
opt_type(_) -> [extauth_instances].
do_call(_, Max, Max, _, _, _, _) ->
{error, disconnected};
do_call(Cmd, I, Max, Pool, PoolSize, EndTime, CurrTime) ->
Timeout = EndTime - CurrTime,
if Timeout > 0 ->
Proc = worker_name(Pool, (I rem PoolSize) + 1),
try ?GEN_SERVER:call(Proc, {cmd, Cmd, EndTime}, Timeout)
catch exit:{timeout, {?GEN_SERVER, call, _}} ->
{error, timeout};
exit:{_, {?GEN_SERVER, call, _}} ->
do_call(Cmd, I+1, Max, Pool, PoolSize, EndTime, curr_time())
end;
true ->
{error, timeout}
end.
decode_bool(0) -> false;
decode_bool(1) -> true.

110
src/extauth_sup.erl Normal file
View File

@ -0,0 +1,110 @@
%%%-------------------------------------------------------------------
%%% Created : 7 May 2018 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2018 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License along
%%% with this program; if not, write to the Free Software Foundation, Inc.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%-------------------------------------------------------------------
-module(extauth_sup).
-behaviour(supervisor).
%% API
-export([start/1, stop/1, reload/1, start_link/3]).
%% Supervisor callbacks
-export([init/1]).
-include("logger.hrl").
%%%===================================================================
%%% API functions
%%%===================================================================
start(Host) ->
case extauth:prog_name(Host) of
undefined ->
?ERROR_MSG("Option 'extauth_program' is not set for '~s'",
[Host]),
ignore;
Prog ->
Pool = extauth:pool_name(Host),
ChildSpec = {Pool, {?MODULE, start_link, [Host, Prog, Pool]},
transient, infinity, supervisor, [?MODULE]},
supervisor:start_child(ejabberd_backend_sup, ChildSpec)
end.
stop(Host) ->
Pool = extauth:pool_name(Host),
supervisor:terminate_child(ejabberd_backend_sup, Pool),
supervisor:delete_child(ejabberd_backend_sup, Pool).
reload(Host) ->
Pool = extauth:pool_name(Host),
Prog = extauth:prog_name(Host),
PoolSize = extauth:pool_size(Host),
try process_info(whereis(Pool), dictionary) of
{dictionary, Dict} ->
case proplists:get_value(extauth_program, Dict) of
Prog ->
OldPoolSize = try supervisor:which_children(Pool) of
Children -> length(Children)
catch _:_ -> PoolSize
end,
if OldPoolSize > PoolSize ->
lists:foreach(
fun(I) ->
Worker = extauth:worker_name(Pool, I),
supervisor:terminate_child(Pool, Worker),
supervisor:delete_child(Pool, Worker)
end, lists:seq(PoolSize+1, OldPoolSize));
OldPoolSize < PoolSize ->
lists:foreach(
fun(I) ->
Spec = worker_spec(Pool, Prog, I),
supervisor:start_child(Pool, Spec)
end, lists:seq(OldPoolSize+1, PoolSize));
OldPoolSize == PoolSize ->
ok
end;
_ ->
stop(Host),
start(Host)
end
catch _:badarg ->
ok
end.
start_link(Host, Prog, Pool) ->
supervisor:start_link({local, Pool}, ?MODULE, [Host, Prog, Pool]).
%%%===================================================================
%%% Supervisor callbacks
%%%===================================================================
init([Host, Prog, Pool]) ->
PoolSize = extauth:pool_size(Host),
Children = lists:map(
fun(I) ->
worker_spec(Pool, Prog, I)
end, lists:seq(1, PoolSize)),
put(extauth_program, Prog),
{ok, {{one_for_one, PoolSize, 1}, Children}}.
%%%===================================================================
%%% Internal functions
%%%===================================================================
worker_spec(Pool, Prog, I) ->
Worker = extauth:worker_name(Pool, I),
{Worker, {extauth, start_link, [Worker, Prog]},
permanent, 5000, worker, [extauth]}.