%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2007-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%% SCTP protocol contribution by Leonid Timochouk and Serge Aleynikov.
%% See also: $ERL_TOP/lib/kernel/AUTHORS
%%
-module(inet_sctp).
%% This module provides functions for communicating with
%% sockets using the SCTP protocol. The implementation assumes that
%% the OS kernel supports SCTP providing user-level SCTP Socket API:
%% http://tools.ietf.org/html/draft-ietf-tsvwg-sctpsocket-13
-include("inet_sctp.hrl").
-include("inet_int.hrl").
-define(FAMILY, inet).
-export([getserv/1,getaddr/1,getaddr/2,translate_ip/1]).
-export([open/1,close/1,listen/2,connect/5,sendmsg/3,recv/2]).
getserv(Port) when is_integer(Port) -> {ok, Port};
getserv(Name) when is_atom(Name) ->
inet:getservbyname(Name, sctp);
getserv(_) ->
{error,einval}.
getaddr(Address) ->
inet:getaddr(Address, ?FAMILY).
getaddr(Address, Timer) ->
inet:getaddr_tm(Address, ?FAMILY, Timer).
translate_ip(IP) ->
inet:translate_ip(IP, ?FAMILY).
open(Opts) ->
case inet:sctp_options(Opts, ?MODULE) of
{ok,#sctp_opts{fd=Fd,ifaddr=Addr,port=Port,opts=SOs}} ->
inet:open(Fd, Addr, Port, SOs, sctp, ?FAMILY, ?MODULE);
Error -> Error
end.
close(S) ->
prim_inet:close(S).
listen(S, Flag) ->
prim_inet:listen(S, Flag).
%% A non-blocking connect is implemented when the initial call is to
%% gen_sctp:connect_init which passes the value nowait as the Timer
connect(S, Addr, Port, Opts, Timer) ->
case prim_inet:chgopts(S, Opts) of
ok ->
case prim_inet:getopt(S, active) of
{ok,Active} ->
Timeout = if Timer =:= nowait ->
infinity; %% don't start driver timer in inet_drv
true ->
inet:timeout(Timer)
end,
case prim_inet:connect(S, Addr, Port, Timeout) of
ok when Timer =/= nowait ->
connect_get_assoc(S, Addr, Port, Active, Timer);
OkOrErr1 -> OkOrErr1
end;
Err2 -> Err2
end;
Err3 -> Err3
end.
%% XXX race condition problem
%%
%% If an incoming #sctp_assoc_change{} arrives after
%% prim_inet:getopt(S, alive) above but before the
%% #sctp_assoc_change{state=comm_up} originating from
%% prim_inet:connect(S, Addr, Port, Timeout) above,
%% connect_get_assoc/5 below mistakes it for an invalid response
%% for a socket in {active,false} or {active,once} modes.
%%
%% In {active,true} mode the window of time for the race is smaller,
%% but it is possible and also it is a blocking connect that is
%% implemented even for {active,true}, and that may be a
%% shortcoming.
connect_get_assoc(S, Addr, Port, false, Timer) ->
case recv(S, inet:timeout(Timer)) of
{ok, {Addr, Port, [], #sctp_assoc_change{state=St}=Ev}} ->
if St =:= comm_up ->
%% Yes, successfully connected, return the whole
%% sctp_assoc_change event (containing, in particular,
%% the AssocID).
%% NB: we consider the connection to be successful
%% even if the number of OutStreams is not the same
%% as requested by the user:
{ok,Ev};
true ->
{error,Ev}
end;
%% Any other event: Error:
{ok, Msg} ->
{error, Msg};
{error,_}=Error ->
Error
end;
connect_get_assoc(S, Addr, Port, Active, Timer) ->
Timeout = inet:timeout(Timer),
receive
{sctp,S,Addr,Port,{[],#sctp_assoc_change{state=St}=Ev}} ->
case Active of
once ->
prim_inet:setopt(S, active, once);
_ -> ok
end,
if St =:= comm_up ->
{ok,Ev};
true ->
{error,Ev}
end
after Timeout ->
{error,timeout}
end.
sendmsg(S, SRI, Data) ->
prim_inet:sendmsg(S, SRI, Data).
recv(S, Timeout) ->
prim_inet:recvfrom(S, 0, Timeout).
