%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2016. 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%
%%
%% A simple boot_server at a CP.
%%
%% This server should know about which slaves (DP's or whatever) to boot.
%% File's (with absolute path name) will be fetched.
%%
-module(erl_boot_server).
-include("inet_boot.hrl").
-behaviour(gen_server).
%% API functions.
-export([start/1, start_link/1, add_slave/1, delete_slave/1,
add_subnet/2, delete_subnet/2,
which_slaves/0]).
%% Exports for testing (dont't remove; tests suites depend on them).
-export([would_be_booted/1]).
%% Internal exports
-export([init/1,handle_call/3,handle_cast/2,handle_info/2,terminate/2]).
-export([code_change/3]).
-export([boot_init/1, boot_accept/3]).
-record(state,
{
priority = 0, %% priority of this server
version = "" :: string(), %% Version handled i.e "4.5.3" etc
udp_sock, %% listen port for broadcase requests
udp_port, %% port number must be ?EBOOT_PORT!
listen_sock, %% listen sock for incoming file requests
listen_port, %% listen port number
slaves, %% list of accepted ip addresses
bootp :: pid(), %% boot process
prim_state %% state for efile code loader
}).
-type state() :: #state{}.
-define(single_addr_mask, {255, 255, 255, 255}).
-type ip4_address() :: {0..255,0..255,0..255,0..255}.
-spec start(Slaves) -> {'ok', Pid} | {'error', What} when
Slaves :: [Host],
Host :: atom(),
Pid :: pid(),
What :: any().
start(Slaves) ->
case check_arg(Slaves) of
{ok, AL} ->
gen_server:start({local,boot_server}, erl_boot_server, AL, []);
_ ->
{error, {badarg, Slaves}}
end.
-spec start_link(Slaves) -> {'ok', Pid} | {'error', What} when
Slaves :: [Host],
Host :: atom(),
Pid :: pid(),
What :: any().
start_link(Slaves) ->
case check_arg(Slaves) of
{ok, AL} ->
gen_server:start_link({local,boot_server},
erl_boot_server, AL, []);
_ ->
{error, {badarg, Slaves}}
end.
check_arg(Slaves) ->
check_arg(Slaves, []).
check_arg([Slave|Rest], Result) ->
case inet:getaddr(Slave, inet) of
{ok, IP} ->
check_arg(Rest, [{?single_addr_mask, IP}|Result]);
_ ->
error
end;
check_arg([], Result) ->
{ok, Result};
check_arg(_, _Result) ->
error.
-spec add_slave(Slave) -> 'ok' | {'error', What} when
Slave :: Host,
Host :: atom(),
What :: any().
add_slave(Slave) ->
case inet:getaddr(Slave, inet) of
{ok,IP} ->
gen_server:call(boot_server, {add, {?single_addr_mask, IP}});
_ ->
{error, {badarg, Slave}}
end.
-spec delete_slave(Slave) -> 'ok' | {'error', What} when
Slave :: Host,
Host :: atom(),
What :: any().
delete_slave(Slave) ->
case inet:getaddr(Slave, inet) of
{ok,IP} ->
gen_server:call(boot_server, {delete, {?single_addr_mask, IP}});
_ ->
{error, {badarg, Slave}}
end.
-spec add_subnet(Mask :: ip4_address(), Addr :: ip4_address()) ->
'ok' | {'error', any()}.
add_subnet(Mask, Addr) when is_tuple(Mask), is_tuple(Addr) ->
case member_address(Addr, [{Mask, Addr}]) of
true ->
gen_server:call(boot_server, {add, {Mask, Addr}});
false ->
{error, empty_subnet}
end.
-spec delete_subnet(Mask :: ip4_address(), Addr :: ip4_address()) -> 'ok'.
delete_subnet(Mask, Addr) when is_tuple(Mask), is_tuple(Addr) ->
gen_server:call(boot_server, {delete, {Mask, Addr}}).
-spec which_slaves() -> Slaves when
Slaves :: [Host],
Host :: atom().
which_slaves() ->
gen_server:call(boot_server, which).
%% Given a host name or IP address, returns true if a host
%% having that IP address would be accepted for booting, and
%% false otherwise. (Convenient for testing.)
would_be_booted(Addr) ->
{ok, IP} = inet:getaddr(Addr, inet),
member_address(IP, which_slaves()).
int16(X) when is_integer(X) ->
[(X bsr 8) band 16#ff, (X) band 16#ff].
%% Check if an address is a member
member_address(IP, [{{MA, MB, MC, MD}, {EA, EB, EC, ED}}|Rest]) ->
{A, B, C, D} = IP,
if A band MA =:= EA,
B band MB =:= EB,
C band MC =:= EC,
D band MD =:= ED ->
true;
true ->
member_address(IP, Rest)
end;
member_address(_, []) ->
false.
%% ------------------------------------------------------------
%% call-back functions.
%% ------------------------------------------------------------
-spec init([atom()]) -> {'ok', state()}.
init(Slaves) ->
{ok, U} = gen_udp:open(?EBOOT_PORT, []),
{ok, L} = gen_tcp:listen(0, [binary,{packet,4}]),
{ok, Port} = inet:port(L),
{ok, UPort} = inet:port(U),
Ref = make_ref(),
Pid = proc_lib:spawn_link(?MODULE, boot_init, [Ref]),
ok = gen_tcp:controlling_process(L, Pid),
Pid ! {Ref, L},
%% We trap exit inorder to restart boot_init and udp_port
process_flag(trap_exit, true),
{ok, #state{priority = 0,
version = erlang:system_info(version),
udp_sock = U,
udp_port = UPort,
listen_sock = L,
listen_port = Port,
slaves = ordsets:from_list(Slaves),
bootp = Pid
}}.
-spec handle_call('which' | {'add',atom()} | {'delete',atom()}, _, state()) ->
{'reply', 'ok' | [atom()], state()}.
handle_call({add,Address}, _, S0) ->
Slaves = ordsets:add_element(Address, S0#state.slaves),
S0#state.bootp ! {slaves, Slaves},
{reply, ok, S0#state{slaves = Slaves}};
handle_call({delete,Address}, _, S0) ->
Slaves = ordsets:del_element(Address, S0#state.slaves),
S0#state.bootp ! {slaves, Slaves},
{reply, ok, S0#state{slaves = Slaves}};
handle_call(which, _, S0) ->
{reply, ordsets:to_list(S0#state.slaves), S0}.
-spec handle_cast(term(), [atom()]) -> {'noreply', [atom()]}.
handle_cast(_, Slaves) ->
{noreply, Slaves}.
-spec handle_info(term(), state()) -> {'noreply', state()}.
handle_info({udp, U, IP, Port, Data}, S0) ->
Token = ?EBOOT_REQUEST ++ S0#state.version,
Valid = member_address(IP, ordsets:to_list(S0#state.slaves)),
%% check that the connecting node is valid and has the same
%% erlang version as the boot server node
case {Valid,Data,Token} of
{true,Token,Token} ->
case gen_udp:send(U,IP,Port,[?EBOOT_REPLY,S0#state.priority,
int16(S0#state.listen_port),
S0#state.version])
of
ok -> ok;
{error, not_owner} ->
error_logger:error_msg("** Illegal boot server connection attempt: "
"not owner of ~w ** ~n", [U]);
{error, Reason} ->
Err = file:format_error(Reason),
error_logger:error_msg("** Illegal boot server connection attempt: "
"~w POSIX error ** ~n", [U, Err])
end,
{noreply,S0};
{false,_,_} ->
error_logger:error_msg("** Illegal boot server connection attempt: "
"~w is not a valid address ** ~n", [IP]),
{noreply,S0};
{true,_,_} ->
case catch string:substr(Data, 1, length(?EBOOT_REQUEST)) of
?EBOOT_REQUEST ->
Vsn = string:substr(Data, length(?EBOOT_REQUEST)+1, length(Data)),
error_logger:error_msg("** Illegal boot server connection attempt: "
"client version is ~s ** ~n", [Vsn]);
_ ->
error_logger:error_msg("** Illegal boot server connection attempt: "
"unrecognizable request ** ~n", [])
end,
{noreply,S0}
end;
handle_info(_Info, S0) ->
{noreply,S0}.
-spec terminate(term(), state()) -> 'ok'.
terminate(_Reason, _S0) ->
ok.
-spec code_change(term(), state(), term()) -> {'ok', state()}.
code_change(_Vsn, State, _Extra) ->
{ok, State}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Boot server
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec boot_init(reference()) -> no_return().
boot_init(Tag) ->
receive
{Tag, Listen} ->
process_flag(trap_exit, true),
boot_main(Listen)
end.
boot_main(Listen) ->
Tag = make_ref(),
Pid = proc_lib:spawn_link(?MODULE, boot_accept, [self(), Listen, Tag]),
boot_main(Listen, Tag, Pid).
boot_main(Listen, Tag, Pid) ->
receive
{Tag, _} ->
boot_main(Listen);
{'EXIT', Pid, _} ->
boot_main(Listen);
{'EXIT', _, Reason} ->
exit(Pid, kill),
exit(Reason);
{tcp_closed, Listen} ->
exit(closed)
end.
boot_accept(Server, Listen, Tag) ->
Reply = gen_tcp:accept(Listen),
unlink(Server),
Server ! {Tag, continue},
case Reply of
{ok, Socket} ->
{ok, {IP, _Port}} = inet:peername(Socket),
true = member_address(IP, which_slaves()),
PS = erl_prim_loader:prim_init(),
boot_loop(Socket, PS)
end.
boot_loop(Socket, PS) ->
receive
{tcp, Socket, Data} ->
PS2 = handle_command(Socket, PS, Data),
boot_loop(Socket, PS2);
{tcp_closed, Socket} ->
true
end.
handle_command(S, PS, Msg) ->
case catch binary_to_term(Msg) of
{get,File} ->
{Res, PS2} = erl_prim_loader:prim_get_file(PS, File),
send_file_result(S, get, Res),
PS2;
{list_dir,Dir} ->
{Res, PS2} = erl_prim_loader:prim_list_dir(PS, Dir),
send_file_result(S, list_dir, Res),
PS2;
{read_file_info,File} ->
{Res, PS2} = erl_prim_loader:prim_read_file_info(PS, File, true),
send_file_result(S, read_file_info, Res),
PS2;
{read_link_info,File} ->
{Res, PS2} = erl_prim_loader:prim_read_file_info(PS, File, false),
send_file_result(S, read_link_info, Res),
PS2;
get_cwd ->
{Res, PS2} = erl_prim_loader:prim_get_cwd(PS, []),
send_file_result(S, get_cwd, Res),
PS2;
{get_cwd,Drive} ->
{Res, PS2} = erl_prim_loader:prim_get_cwd(PS, [Drive]),
send_file_result(S, get_cwd, Res),
PS2;
{'EXIT',Reason} ->
send_result(S, {error,Reason}),
PS;
_Other ->
send_result(S, {error,unknown_command}),
PS
end.
send_file_result(S, Cmd, Result) ->
send_result(S, {Cmd,Result}).
send_result(S, Term) ->
case gen_tcp:send(S, term_to_binary(Term)) of
ok ->
ok;
Error ->
error_logger:error_msg("** Boot server could not send result "
"to socket: ~w** ~n", [Error]),
ok
end.
