%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
%%
%% 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.
%%
%% %CopyrightEnd%
%%
-module(os_sup).
-behaviour(gen_server).
%% API
-export([start_link/1, start/0, stop/0]).
-export([error_report/2]).
-export([enable/0, enable/2, disable/0, disable/2]).
-export([param_type/2, param_default/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-record(state, {port, mfa, config, path, conf}).
%%----------------------------------------------------------------------
%% API
%%----------------------------------------------------------------------
start_link({win32, _OSname}) ->
Identifier = os_sup,
MFA = os_mon:get_env(os_sup, os_sup_mfa),
gen_server:start_link({local, os_sup_server}, nteventlog,
[Identifier, MFA], []);
start_link(_OS) ->
gen_server:start_link({local, os_sup_server}, os_sup, [], []).
start() -> % for testing
gen_server:start({local, os_sup_server}, os_sup, [], []).
stop() ->
gen_server:call(os_sup_server, stop).
error_report(LogData, Tag) ->
error_logger:error_report(Tag, LogData).
enable() ->
command(enable).
enable(Path, Conf) ->
command(enable, Path, Conf).
disable() ->
command(disable).
disable(Path, Conf) ->
command(disable, Path, Conf).
param_type(os_sup_errortag, Val) when is_atom(Val) -> true;
param_type(os_sup_own, Val) -> io_lib:printable_list(Val);
param_type(os_sup_syslogconf, Val) -> io_lib:printable_list(Val);
param_type(os_sup_enable, Val) when Val==true; Val==false -> true;
param_type(os_sup_mfa, {Mod,Func,Args}) when is_atom(Mod),
is_atom(Func),
is_list(Args) -> true;
param_type(_Param, _Val) -> false.
param_default(os_sup_errortag) -> std_error;
param_default(os_sup_own) -> "/etc";
param_default(os_sup_syslogconf) -> "/etc/syslog.conf";
param_default(os_sup_enable) -> true;
param_default(os_sup_mfa) -> {os_sup, error_report, [std_error]}.
%%----------------------------------------------------------------------
%% gen_server callbacks
%%----------------------------------------------------------------------
init([]) ->
process_flag(trap_exit, true),
process_flag(priority, low),
case os:type() of
{unix, sunos} ->
init2();
OS -> {stop, {unsupported_os, OS}}
end.
init2() -> % Enable service if configured to do so
ConfigP = os_mon:get_env(os_sup, os_sup_enable),
case ConfigP of
true -> % ..yes -- do enable
Path = os_mon:get_env(os_sup, os_sup_own),
Conf = os_mon:get_env(os_sup, os_sup_syslogconf),
case enable(Path, Conf) of
ok ->
init3(#state{config=ConfigP, path=Path, conf=Conf});
{error, Error} ->
{stop, {mod_syslog, Error}}
end;
false -> % ..no -- skip directly to init3/1
init3(#state{config=ConfigP})
end.
init3(State0) ->
Port = start_portprogram(),
%% Read the values of some configuration parameters
MFA = case os_mon:get_env(os_sup, os_sup_mfa) of
{os_sup, error_report, _} ->
Tag = os_mon:get_env(os_sup, os_sup_errortag),
{os_sup, error_report, [Tag]};
MFA0 ->
MFA0
end,
{ok, State0#state{port=Port, mfa=MFA}}.
handle_call(stop, _From, State) ->
{stop, normal, ok, State}.
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({_Port, {data, Data}}, #state{mfa={M,F,A}} = State) ->
apply(M, F, [Data | A]),
{noreply, State};
handle_info({'EXIT', _Port, Reason}, State) ->
{stop, {port_died, Reason}, State#state{port=not_used}};
handle_info(_Info, State) ->
{noreply, State}.
terminate(_Reason, #state{port=Port} = State) ->
case State#state.config of
true when is_port(Port) ->
Port ! {self(), {command, "only_stdin"}},
Res = disable(State#state.path, State#state.conf),
port_close(Port),
if
Res/="0" -> exit({mod_syslog, Res});
true -> ok
end;
true ->
Res = disable(State#state.path, State#state.conf),
if
Res/="0" -> exit({mod_syslog, Res});
true -> ok
end;
false when is_port(Port) ->
Port ! {self(), {command, "only_stdin"}},
port_close(Port);
false ->
ok
end.
%% os_mon-2.0
%% For live downgrade to/upgrade from os_mon-1.8[.1]
code_change(Vsn, PrevState, "1.8") ->
case Vsn of
%% Downgrade from this version
{down, _Vsn} ->
%% Find out the error tag used
{DefM, DefF, _} = param_default(os_sup_mfa),
Tag = case PrevState#state.mfa of
%% Default callback function is used, then use
%% the corresponding tag
{DefM, DefF, [Tag0]} ->
Tag0;
%% Default callback function is *not* used
%% (before the downgrade, that is)
%% -- check the configuration parameter
_ ->
case application:get_env(os_mon,
os_sup_errortag) of
{ok, Tag1} ->
Tag1;
%% (actually, if it has no value,
%% the process should terminate
%% according to 1.8.1 version, but that
%% seems too harsh here)
_ ->
std_error
end
end,
%% Downgrade to old state record
State = {state, PrevState#state.port, Tag},
{ok, State};
%% Upgrade to this version
_Vsn ->
{state, Port, Tag} = PrevState,
{DefM, DefF, _} = param_default(os_sup_mfa),
MFA = {DefM, DefF, [Tag]},
%% We can safely assume the following configuration
%% parameters are defined, otherwise os_sup would never had
%% started in the first place.
%% (We can *not* safely assume they haven't been changed,
%% but that's a weakness inherited from the 1.8.1 version)
Path = application:get_env(os_mon, os_sup_own),
Conf = application:get_env(os_mon, os_sup_syslogconf),
%% Upgrade to this state record
State = #state{port=Port, mfa=MFA, config=true,
path=Path, conf=Conf},
{ok, State}
end;
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%----------------------------------------------------------------------
%% Internal functions
%%----------------------------------------------------------------------
start_portprogram() ->
OwnPath = os_mon:get_env(os_sup, os_sup_own),
Command =
"\"" ++ filename:join([code:priv_dir(os_mon), "bin", "ferrule"]) ++
"\" " ++ OwnPath,
open_port({spawn, Command}, [{packet, 2}]).
%% os:cmd(cmd_str(enable)) should be done BEFORE starting os_sup
%% os:cmd(cmd_str(disable)) should be done AFTER os_sup is terminated
%% Both commands return "0" if successful
command(Mode) ->
command(Mode, "/etc", "/etc/syslog.conf").
command(Mode, Path, Conf) ->
case os:cmd(cmd_str(Mode, Path, Conf)) of
"0" ->
ok;
Error ->
{error, Error}
end.
cmd_str(Mode, Path, Conf) ->
%% modpgm modesw ownpath syslogconf
PrivDir = code:priv_dir(os_mon),
ModeSw =
case Mode of
enable ->
" otp ";
disable ->
" nootp "
end,
PrivDir ++ "/bin/mod_syslog" ++ ModeSw ++ Path ++ " " ++ Conf.
