%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2011. 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_udp).
-export([open/1, open/2, close/1]).
-export([send/2, send/4, recv/2, recv/3, connect/3]).
-export([controlling_process/2]).
-export([fdopen/2]).
-export([getserv/1, getaddr/1, getaddr/2]).
-include("inet_int.hrl").
-define(RECBUF, (8*1024)).
%% inet_udp port lookup
getserv(Port) when is_integer(Port) -> {ok, Port};
getserv(Name) when is_atom(Name) -> inet:getservbyname(Name,udp).
%% inet_udp address lookup
getaddr(Address) -> inet:getaddr(Address, inet).
getaddr(Address,Timer) -> inet:getaddr_tm(Address, inet, Timer).
-spec open(_) -> {ok, inet:socket()} | {error, atom()}.
open(Port) -> open(Port, []).
-spec open(_, _) -> {ok, inet:socket()} | {error, atom()}.
open(Port, Opts) ->
case inet:udp_options(
[{port,Port}, {recbuf, ?RECBUF} | Opts],
inet) of
{error, Reason} -> exit(Reason);
{ok, #udp_opts{fd=Fd,
ifaddr=BAddr={A,B,C,D},
port=BPort,
opts=SockOpts}} when ?ip(A,B,C,D), ?port(BPort) ->
inet:open(Fd,BAddr,BPort,SockOpts,udp,inet,dgram,?MODULE);
{ok, _} -> exit(badarg)
end.
send(S,{A,B,C,D},P,Data) when ?ip(A,B,C,D), ?port(P) ->
prim_inet:sendto(S, {A,B,C,D}, P, Data).
send(S, Data) ->
prim_inet:sendto(S, {0,0,0,0}, 0, Data).
connect(S, {A,B,C,D}, P) when ?ip(A,B,C,D), ?port(P) ->
prim_inet:connect(S, {A,B,C,D}, P).
recv(S,Len) ->
prim_inet:recvfrom(S, Len).
recv(S,Len,Time) ->
prim_inet:recvfrom(S, Len, Time).
-spec close(inet:socket()) -> ok.
close(S) ->
inet:udp_close(S).
%%
%% Set controlling process:
%% 1) First sync socket into a known state
%% 2) Move all messages onto the new owners message queue
%% 3) Commit the owner
%% 4) Wait for ack of new Owner (since socket does some link and unlink)
%%
controlling_process(Socket, NewOwner) ->
inet:udp_controlling_process(Socket, NewOwner).
%%
%% Create a port/socket from a file descriptor
%%
fdopen(Fd, Opts) ->
inet:fdopen(Fd,
optuniquify([{recbuf, ?RECBUF} | Opts]),
udp, inet, dgram, ?MODULE).
%% Remove all duplicate options from an option list.
%% The last occurring duplicate is used, and the order is preserved.
%%
%% Here's how:
%% Reverse the list.
%% For each head option go through the tail and remove
%% all occurences of the same option from the tail.
%% Store that head option and iterate using the new tail.
%% Return the list of stored head options.
optuniquify(List) ->
optuniquify(lists:reverse(List), []).
optuniquify([], Result) ->
Result;
optuniquify([Opt | Tail], Result) ->
%% Remove all occurences of Opt in Tail,
%% prepend Opt to Result,
%% then iterate back here.
optuniquify(Opt, Tail, [], Result).
%% All duplicates of current option are now removed
optuniquify(Opt, [], Rest, Result) ->
%% Store unique option
optuniquify(lists:reverse(Rest), [Opt | Result]);
%% Duplicate option tuple
optuniquify(Opt0, [Opt1 | Tail], Rest, Result)
when tuple_size(Opt0) =:= tuple_size(Opt1),
element(1, Opt0) =:= element(1, Opt1) ->
%% Waste duplicate
optuniquify(Opt0, Tail, Rest, Result);
%% Duplicate option atom or other term
optuniquify(Opt, [Opt | Tail], Rest, Result) ->
%% Waste duplicate
optuniquify(Opt, Tail, Rest, Result);
%% Non-duplicate option
optuniquify(Opt, [X | Tail], Rest, Result) ->
%% Keep non-duplicate
optuniquify(Opt, Tail, [X | Rest], Result).
