%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2018. 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(inet_tcp_dist).
%% Handles the connection setup phase with other Erlang nodes.
-export([listen/1, accept/1, accept_connection/5,
setup/5, close/1, select/1, is_node_name/1]).
%% Optional
-export([setopts/2, getopts/2]).
%% Generalized dist API
-export([gen_listen/2, gen_accept/2, gen_accept_connection/6,
gen_setup/6, gen_select/2]).
%% internal exports
-export([accept_loop/3,do_accept/7,do_setup/7,getstat/1,tick/2]).
-import(error_logger,[error_msg/2]).
-include("net_address.hrl").
-include("dist.hrl").
-include("dist_util.hrl").
%% ------------------------------------------------------------
%% Select this protocol based on node name
%% select(Node) => Bool
%% ------------------------------------------------------------
select(Node) ->
gen_select(inet_tcp, Node).
gen_select(Driver, Node) ->
case split_node(atom_to_list(Node), $@, []) of
[_, Host] ->
case inet:getaddr(Host, Driver:family()) of
{ok,_} -> true;
_ -> false
end;
_ -> false
end.
%% ------------------------------------------------------------
%% Create the listen socket, i.e. the port that this erlang
%% node is accessible through.
%% ------------------------------------------------------------
listen(Name) ->
gen_listen(inet_tcp, Name).
gen_listen(Driver, Name) ->
case do_listen(Driver, [{active, false}, {packet,2}, {reuseaddr, true}]) of
{ok, Socket} ->
TcpAddress = get_tcp_address(Driver, Socket),
{_,Port} = TcpAddress#net_address.address,
ErlEpmd = net_kernel:epmd_module(),
case ErlEpmd:register_node(Name, Port, Driver) of
{ok, Creation} ->
{ok, {Socket, TcpAddress, Creation}};
Error ->
Error
end;
Error ->
Error
end.
do_listen(Driver, Options) ->
{First,Last} = case application:get_env(kernel,inet_dist_listen_min) of
{ok,N} when is_integer(N) ->
case application:get_env(kernel,
inet_dist_listen_max) of
{ok,M} when is_integer(M) ->
{N,M};
_ ->
{N,N}
end;
_ ->
{0,0}
end,
do_listen(Driver, First, Last, listen_options([{backlog,128}|Options])).
do_listen(_Driver, First,Last,_) when First > Last ->
{error,eaddrinuse};
do_listen(Driver, First,Last,Options) ->
case Driver:listen(First, Options) of
{error, eaddrinuse} ->
do_listen(Driver, First+1,Last,Options);
Other ->
Other
end.
listen_options(Opts0) ->
Opts1 =
case application:get_env(kernel, inet_dist_use_interface) of
{ok, Ip} ->
[{ip, Ip} | Opts0];
_ ->
Opts0
end,
case application:get_env(kernel, inet_dist_listen_options) of
{ok,ListenOpts} ->
ListenOpts ++ Opts1;
_ ->
Opts1
end.
%% ------------------------------------------------------------
%% Accepts new connection attempts from other Erlang nodes.
%% ------------------------------------------------------------
accept(Listen) ->
gen_accept(inet_tcp, Listen).
gen_accept(Driver, Listen) ->
spawn_opt(?MODULE, accept_loop, [Driver, self(), Listen], [link, {priority, max}]).
accept_loop(Driver, Kernel, Listen) ->
case Driver:accept(Listen) of
{ok, Socket} ->
Kernel ! {accept,self(),Socket,Driver:family(),tcp},
_ = controller(Driver, Kernel, Socket),
accept_loop(Driver, Kernel, Listen);
Error ->
exit(Error)
end.
controller(Driver, Kernel, Socket) ->
receive
{Kernel, controller, Pid} ->
flush_controller(Pid, Socket),
Driver:controlling_process(Socket, Pid),
flush_controller(Pid, Socket),
Pid ! {self(), controller};
{Kernel, unsupported_protocol} ->
exit(unsupported_protocol)
end.
flush_controller(Pid, Socket) ->
receive
{tcp, Socket, Data} ->
Pid ! {tcp, Socket, Data},
flush_controller(Pid, Socket);
{tcp_closed, Socket} ->
Pid ! {tcp_closed, Socket},
flush_controller(Pid, Socket)
after 0 ->
ok
end.
%% ------------------------------------------------------------
%% Accepts a new connection attempt from another Erlang node.
%% Performs the handshake with the other side.
%% ------------------------------------------------------------
accept_connection(AcceptPid, Socket, MyNode, Allowed, SetupTime) ->
gen_accept_connection(inet_tcp, AcceptPid, Socket, MyNode, Allowed, SetupTime).
gen_accept_connection(Driver, AcceptPid, Socket, MyNode, Allowed, SetupTime) ->
spawn_opt(?MODULE, do_accept,
[Driver, self(), AcceptPid, Socket, MyNode, Allowed, SetupTime],
[link, {priority, max}]).
do_accept(Driver, Kernel, AcceptPid, Socket, MyNode, Allowed, SetupTime) ->
receive
{AcceptPid, controller} ->
Timer = dist_util:start_timer(SetupTime),
case check_ip(Driver, Socket) of
true ->
HSData = #hs_data{
kernel_pid = Kernel,
this_node = MyNode,
socket = Socket,
timer = Timer,
this_flags = 0,
allowed = Allowed,
f_send = fun Driver:send/2,
f_recv = fun Driver:recv/3,
f_setopts_pre_nodeup =
fun(S) ->
inet:setopts(S,
[{active, false},
{packet, 4},
nodelay()])
end,
f_setopts_post_nodeup =
fun(S) ->
inet:setopts(S,
[{active, true},
{deliver, port},
{packet, 4},
nodelay()])
end,
f_getll = fun(S) ->
inet:getll(S)
end,
f_address = fun(S, Node) -> get_remote_id(Driver, S, Node) end,
mf_tick = fun(S) -> ?MODULE:tick(Driver, S) end,
mf_getstat = fun ?MODULE:getstat/1,
mf_setopts = fun ?MODULE:setopts/2,
mf_getopts = fun ?MODULE:getopts/2
},
dist_util:handshake_other_started(HSData);
{false,IP} ->
error_msg("** Connection attempt from "
"disallowed IP ~w ** ~n", [IP]),
?shutdown(no_node)
end
end.
%% we may not always want the nodelay behaviour
%% for performance reasons
nodelay() ->
case application:get_env(kernel, dist_nodelay) of
undefined ->
{nodelay, true};
{ok, true} ->
{nodelay, true};
{ok, false} ->
{nodelay, false};
_ ->
{nodelay, true}
end.
%% ------------------------------------------------------------
%% Get remote information about a Socket.
%% ------------------------------------------------------------
get_remote_id(Driver, Socket, Node) ->
case inet:peername(Socket) of
{ok,Address} ->
case split_node(atom_to_list(Node), $@, []) of
[_,Host] ->
#net_address{address=Address,host=Host,
protocol=tcp,family=Driver:family()};
_ ->
%% No '@' or more than one '@' in node name.
?shutdown(no_node)
end;
{error, _Reason} ->
?shutdown(no_node)
end.
%% ------------------------------------------------------------
%% Setup a new connection to another Erlang node.
%% Performs the handshake with the other side.
%% ------------------------------------------------------------
setup(Node, Type, MyNode, LongOrShortNames,SetupTime) ->
gen_setup(inet_tcp, Node, Type, MyNode, LongOrShortNames, SetupTime).
gen_setup(Driver, Node, Type, MyNode, LongOrShortNames, SetupTime) ->
spawn_opt(?MODULE, do_setup,
[Driver, self(), Node, Type, MyNode, LongOrShortNames, SetupTime],
[link, {priority, max}]).
do_setup(Driver, Kernel, Node, Type, MyNode, LongOrShortNames, SetupTime) ->
?trace("~p~n",[{inet_tcp_dist,self(),setup,Node}]),
[Name, Address] = splitnode(Driver, Node, LongOrShortNames),
AddressFamily = Driver:family(),
ErlEpmd = net_kernel:epmd_module(),
{ARMod, ARFun} = get_address_resolver(ErlEpmd),
Timer = dist_util:start_timer(SetupTime),
case ARMod:ARFun(Name, Address, AddressFamily) of
{ok, Ip, TcpPort, Version} ->
?trace("address_please(~p) -> version ~p~n",
[Node,Version]),
do_setup_connect(Driver, Kernel, Node, Address, AddressFamily,
Ip, TcpPort, Version, Type, MyNode, Timer);
{ok, Ip} ->
case ErlEpmd:port_please(Name, Ip) of
{port, TcpPort, Version} ->
?trace("port_please(~p) -> version ~p~n",
[Node,Version]),
do_setup_connect(Driver, Kernel, Node, Address, AddressFamily,
Ip, TcpPort, Version, Type, MyNode, Timer);
_ ->
?trace("port_please (~p) "
"failed.~n", [Node]),
?shutdown(Node)
end;
_Other ->
?trace("inet_getaddr(~p) "
"failed (~p).~n", [Node,_Other]),
?shutdown(Node)
end.
%%
%% Actual setup of connection
%%
do_setup_connect(Driver, Kernel, Node, Address, AddressFamily,
Ip, TcpPort, Version, Type, MyNode, Timer) ->
dist_util:reset_timer(Timer),
case
Driver:connect(
Ip, TcpPort,
connect_options([{active, false}, {packet, 2}]))
of
{ok, Socket} ->
HSData = #hs_data{
kernel_pid = Kernel,
other_node = Node,
this_node = MyNode,
socket = Socket,
timer = Timer,
this_flags = 0,
other_version = Version,
f_send = fun Driver:send/2,
f_recv = fun Driver:recv/3,
f_setopts_pre_nodeup =
fun(S) ->
inet:setopts
(S,
[{active, false},
{packet, 4},
nodelay()])
end,
f_setopts_post_nodeup =
fun(S) ->
inet:setopts
(S,
[{active, true},
{deliver, port},
{packet, 4},
nodelay()])
end,
f_getll = fun inet:getll/1,
f_address =
fun(_,_) ->
#net_address{
address = {Ip,TcpPort},
host = Address,
protocol = tcp,
family = AddressFamily}
end,
mf_tick = fun(S) -> ?MODULE:tick(Driver, S) end,
mf_getstat = fun ?MODULE:getstat/1,
request_type = Type,
mf_setopts = fun ?MODULE:setopts/2,
mf_getopts = fun ?MODULE:getopts/2
},
dist_util:handshake_we_started(HSData);
_ ->
%% Other Node may have closed since
%% discovery !
?trace("other node (~p) "
"closed since discovery (port_please).~n",
[Node]),
?shutdown(Node)
end.
connect_options(Opts) ->
case application:get_env(kernel, inet_dist_connect_options) of
{ok,ConnectOpts} ->
ConnectOpts ++ Opts;
_ ->
Opts
end.
%%
%% Close a socket.
%%
close(Socket) ->
inet_tcp:close(Socket).
%% If Node is illegal terminate the connection setup!!
splitnode(Driver, Node, LongOrShortNames) ->
case split_node(atom_to_list(Node), $@, []) of
[Name|Tail] when Tail =/= [] ->
Host = lists:append(Tail),
case split_node(Host, $., []) of
[_] when LongOrShortNames =:= longnames ->
case Driver:parse_address(Host) of
{ok, _} ->
[Name, Host];
_ ->
error_msg("** System running to use "
"fully qualified "
"hostnames **~n"
"** Hostname ~ts is illegal **~n",
[Host]),
?shutdown(Node)
end;
L when length(L) > 1, LongOrShortNames =:= shortnames ->
error_msg("** System NOT running to use fully qualified "
"hostnames **~n"
"** Hostname ~ts is illegal **~n",
[Host]),
?shutdown(Node);
_ ->
[Name, Host]
end;
[_] ->
error_msg("** Nodename ~p illegal, no '@' character **~n",
[Node]),
?shutdown(Node);
_ ->
error_msg("** Nodename ~p illegal **~n", [Node]),
?shutdown(Node)
end.
split_node([Chr|T], Chr, Ack) -> [lists:reverse(Ack)|split_node(T, Chr, [])];
split_node([H|T], Chr, Ack) -> split_node(T, Chr, [H|Ack]);
split_node([], _, Ack) -> [lists:reverse(Ack)].
%% ------------------------------------------------------------
%% Fetch local information about a Socket.
%% ------------------------------------------------------------
get_tcp_address(Driver, Socket) ->
{ok, Address} = inet:sockname(Socket),
{ok, Host} = inet:gethostname(),
#net_address {
address = Address,
host = Host,
protocol = tcp,
family = Driver:family()
}.
%% ------------------------------------------------------------
%% Determine if EPMD module supports address resolving. Default
%% is to use inet:getaddr/2.
%% ------------------------------------------------------------
get_address_resolver(EpmdModule) ->
case erlang:function_exported(EpmdModule, address_please, 3) of
true -> {EpmdModule, address_please};
_ -> {inet, getaddr}
end.
%% ------------------------------------------------------------
%% Do only accept new connection attempts from nodes at our
%% own LAN, if the check_ip environment parameter is true.
%% ------------------------------------------------------------
check_ip(Driver, Socket) ->
case application:get_env(check_ip) of
{ok, true} ->
case get_ifs(Socket) of
{ok, IFs, IP} ->
check_ip(Driver, IFs, IP);
_ ->
?shutdown(no_node)
end;
_ ->
true
end.
get_ifs(Socket) ->
case inet:peername(Socket) of
{ok, {IP, _}} ->
case inet:getif(Socket) of
{ok, IFs} -> {ok, IFs, IP};
Error -> Error
end;
Error ->
Error
end.
check_ip(Driver, [{OwnIP, _, Netmask}|IFs], PeerIP) ->
case {Driver:mask(Netmask, PeerIP), Driver:mask(Netmask, OwnIP)} of
{M, M} -> true;
_ -> check_ip(Driver, IFs, PeerIP)
end;
check_ip(_Driver, [], PeerIP) ->
{false, PeerIP}.
is_node_name(Node) when is_atom(Node) ->
case split_node(atom_to_list(Node), $@, []) of
[_, _Host] -> true;
_ -> false
end;
is_node_name(_Node) ->
false.
tick(Driver, Socket) ->
case Driver:send(Socket, [], [force]) of
{error, closed} ->
self() ! {tcp_closed, Socket},
{error, closed};
R ->
R
end.
getstat(Socket) ->
case inet:getstat(Socket, [recv_cnt, send_cnt, send_pend]) of
{ok, Stat} ->
split_stat(Stat,0,0,0);
Error ->
Error
end.
split_stat([{recv_cnt, R}|Stat], _, W, P) ->
split_stat(Stat, R, W, P);
split_stat([{send_cnt, W}|Stat], R, _, P) ->
split_stat(Stat, R, W, P);
split_stat([{send_pend, P}|Stat], R, W, _) ->
split_stat(Stat, R, W, P);
split_stat([], R, W, P) ->
{ok, R, W, P}.
setopts(S, Opts) ->
case [Opt || {K,_}=Opt <- Opts,
K =:= active orelse K =:= deliver orelse K =:= packet] of
[] -> inet:setopts(S,Opts);
Opts1 -> {error, {badopts,Opts1}}
end.
getopts(S, Opts) ->
inet:getopts(S, Opts).
