/erts/preloaded/src/prim_inet.erl

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%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 2000-2017. 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%
%%
%% The SCTP protocol was added 2006
%% by Leonid Timochouk <l.timochouk@gmail.com>
%% and Serge Aleynikov  <saleyn@gmail.com>
%% at IDT Corp. Adapted by the OTP team at Ericsson AB.
%%
-module(prim_inet).

%% Primitive inet_drv interface

-export([open/3, open/4, fdopen/4, fdopen/5, close/1]).
-export([bind/3, listen/1, listen/2, peeloff/2]).
-export([connect/3, connect/4, async_connect/4]).
-export([accept/1, accept/2, async_accept/2]).
-export([shutdown/2]).
-export([send/2, send/3, sendto/4, sendmsg/3, sendfile/4]).
-export([recv/2, recv/3, async_recv/3]).
-export([unrecv/2]).
-export([recvfrom/2, recvfrom/3]).
-export([setopt/3, setopts/2, getopt/2, getopts/2, is_sockopt_val/2]).
-export([chgopt/3, chgopts/2]).
-export([getstat/2, getfd/1, ignorefd/2,
	 getindex/1, getstatus/1, gettype/1,
	 getifaddrs/1, getiflist/1, ifget/3, ifset/3,
	 gethostname/1]).
-export([getservbyname/3, getservbyport/3]).
-export([peername/1, setpeername/2, peernames/1, peernames/2]).
-export([sockname/1, setsockname/2, socknames/1, socknames/2]).
-export([attach/1, detach/1]).

-include("inet_sctp.hrl").
-include("inet_int.hrl").

%-define(DEBUG, 1).
-ifdef(DEBUG).
-define(DBG_FORMAT(Format, Args), (io:format((Format), (Args)))).
-else.
-define(DBG_FORMAT(Format, Args), ok).
-endif.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% OPEN(tcp | udp | sctp, inet | inet6, stream | dgram | seqpacket)  ->
%%       {ok, insock()} |
%%       {error, Reason}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

open(Protocol, Family, Type) ->
    open(Protocol, Family, Type, [], ?INET_REQ_OPEN, []).

open(Protocol, Family, Type, Opts) ->
    open(Protocol, Family, Type, Opts, ?INET_REQ_OPEN, []).

%% FDOPEN(tcp|udp|sctp, inet|inet6|local, stream|dgram|seqpacket, integer())

fdopen(Protocol, Family, Type, Fd) when is_integer(Fd) ->
    fdopen(Protocol, Family, Type, Fd, true).

fdopen(Protocol, Family, Type, Fd, Bound)
  when is_integer(Fd), is_boolean(Bound) ->
    open(Protocol, Family, Type, [], ?INET_REQ_FDOPEN,
         [?int32(Fd), enc_value_2(bool, Bound)]).

open(Protocol, Family, Type, Opts, Req, Data) ->
    Drv = protocol2drv(Protocol),
    AF = enc_family(Family),
    T = enc_type(Type),
    try erlang:open_port({spawn_driver,Drv}, [binary]) of
	S ->
	    case setopts(S, Opts) of
		ok ->
		    case ctl_cmd(S, Req, [AF,T,Data]) of
			{ok,_} -> {ok,S};
			{error,_}=E1 ->
			    close(S),
			    E1
		    end;
		{error,_}=E2 ->
		    close(S),
		    E2
	    end
    catch
	%% The only (?) way to get here is to try to open
	%% the sctp driver when it does not exist (badarg)
	error:badarg       -> {error, eprotonosupport};
	%% system_limit if out of port slots
	error:system_limit -> {error, system_limit}
    end.

enc_family(inet)  -> ?INET_AF_INET;
enc_family(inet6) -> ?INET_AF_INET6;
enc_family(local) -> ?INET_AF_LOCAL.

enc_type(stream) -> ?INET_TYPE_STREAM;
enc_type(dgram) -> ?INET_TYPE_DGRAM;
enc_type(seqpacket) -> ?INET_TYPE_SEQPACKET.

protocol2drv(tcp)  -> "tcp_inet";
protocol2drv(udp)  -> "udp_inet";
protocol2drv(sctp) -> "sctp_inet".

drv2protocol("tcp_inet")  -> tcp;
drv2protocol("udp_inet")  -> udp;
drv2protocol("sctp_inet") -> sctp;
drv2protocol(_)           -> undefined.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Shutdown(insock(), atom()) -> ok
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% TODO: shutdown equivalent for SCTP
%%
shutdown(S, read) when is_port(S) ->
    shutdown_1(S, 0);
shutdown(S, write) when is_port(S) ->
    shutdown_1(S, 1);
shutdown(S, read_write) when is_port(S) ->
    shutdown_1(S, 2).

shutdown_1(S, How) ->
    case ctl_cmd(S, ?TCP_REQ_SHUTDOWN, [How]) of
	{ok, []} -> ok;
	{error,_}=Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% CLOSE(insock()) -> ok
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

close(S) when is_port(S) ->
    case getopt(S, linger) of
    	{ok,{true,0}} -> 
	    close_port(S);
	_ ->
	    case subscribe(S, [subs_empty_out_q]) of
		{ok, [{subs_empty_out_q,N}]} when N > 0 ->
		    close_pend_loop(S, N);   %% wait for pending output to be sent
		_ ->
		    close_port(S)
	    end
    end.

close_pend_loop(S, N) ->
    receive
	{empty_out_q,S} ->
	    close_port(S)
    after ?INET_CLOSE_TIMEOUT ->
	    case getstat(S, [send_pend]) of
                {ok, [{send_pend,N1}]} ->
                    if
			N1 =:= N ->
			    close_port(S);
                       true ->
			    close_pend_loop(S, N1)
                    end;
		_ ->
		    close_port(S)
	    end
    end.

close_port(S) ->
    catch erlang:port_close(S),
    receive {'EXIT',S,_} -> ok after 0 -> ok end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% BIND(insock(), IP, Port) -> {ok, integer()} | {error, Reason}
%%
%% bind the insock() to the interface address given by IP and Port
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% Multi-homed "bind": sctp_bindx(). The Op is 'add' or 'remove'.
%% If no addrs are specified, it just does nothing.
%% Function returns {ok, S} on success, unlike TCP/UDP "bind":
bind(S, add, Addrs) when is_port(S), is_list(Addrs) ->
    bindx(S, 1, Addrs);
bind(S, remove, Addrs) when is_port(S), is_list(Addrs) ->
    bindx(S, 0, Addrs);
bind(S, Addr, _) when is_port(S), tuple_size(Addr) =:= 2 ->
    case type_value(set, addr, Addr) of
	true ->
	    case ctl_cmd(S,?INET_REQ_BIND,enc_value(set, addr, Addr)) of
		{ok, [P1,P0]} -> {ok, ?u16(P1, P0)};
		{error, _} = Error -> Error
	    end;
	false ->
	    {error, einval}
    end;
bind(S, IP, Port) ->
    bind(S, {IP, Port}, 0).

bindx(S, AddFlag, Addrs) ->
    case getprotocol(S) of
	sctp ->
	    case bindx_check_addrs(Addrs) of
		true ->
		    %% Really multi-homed "bindx". Stringified args:
		    %% [AddFlag, (AddrBytes see enc_value_2(addr,X))+]:
		    Args =
			[?int8(AddFlag)|
			 [enc_value(set, addr, Addr) || Addr <- Addrs]],
		    case ctl_cmd(S, ?SCTP_REQ_BINDX, Args) of
			{ok, _} -> {ok, S};
			{error, _}=Error  -> Error
		    end;
		false ->
		    {error, einval}
	    end;
	_ ->
	    {error, einval}
    end.

bindx_check_addrs([Addr|Addrs]) ->
    type_value(set, addr, Addr) andalso bindx_check_addrs(Addrs);
bindx_check_addrs([]) ->
    true.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% CONNECT(insock(), IP, Port [,Timeout]) -> ok | {error, Reason}
%%
%% connect the insock() to the address given by IP and Port
%% if timeout is given:
%%       timeout < 0  -> infinity
%%                 0  -> immediate connect (mostly works for loopback)
%%               > 0  -> wait for timeout ms if not connected then 
%%                       return {error, timeout} 
%%
%% ASYNC_CONNECT(insock(), IP, Port, Timeout) -> {ok, S, Ref} | {error, Reason}
%%
%%  a {inet_async,S,Ref,Status} will be sent on socket condition
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% For TCP, UDP or SCTP sockets.
%%

connect(S, IP, Port) ->
    connect(S, IP, Port, infinity).
%%
connect(S, Addr, _, Time) when is_port(S), tuple_size(Addr) =:= 2 ->
    case type_value(set, addr, Addr) of
	true when Time =:= infinity ->
	    connect0(S, Addr, -1);
	true when is_integer(Time) ->
	    connect0(S, Addr, Time);
	false ->
	    {error, einval}
    end;
connect(S, IP, Port, Time) ->
    connect(S, {IP, Port}, 0, Time).

connect0(S, Addr, Time) ->
    case async_connect0(S, Addr, Time) of
	{ok, S, Ref} ->
	    receive
		{inet_async, S, Ref, Status} ->
		    Status
	    end;
	Error -> Error
    end.


async_connect(S, Addr, _, Time) when is_port(S), tuple_size(Addr) =:= 2 ->
    case type_value(set, addr, Addr) of
	true when Time =:= infinity ->
	    async_connect0(S, Addr, -1);
	true when is_integer(Time) ->
	    async_connect0(S, Addr, Time);
	false ->
	    {error, einval}
    end;
%%
async_connect(S, IP, Port, Time) ->
    async_connect(S, {IP, Port}, 0, Time).

async_connect0(S, Addr, Time) ->
    case ctl_cmd(
	   S, ?INET_REQ_CONNECT,
	   [enc_time(Time),enc_value(set, addr, Addr)])
    of
	{ok, [R1,R0]} -> {ok, S, ?u16(R1,R0)};
	{error, _}=Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% ACCEPT(insock() [,Timeout] ) -> {ok,insock()} | {error, Reason}
%%
%% accept incoming connection on listen socket 
%% if timeout is given:
%%       timeout < 0  -> infinity
%%                 0  -> immediate accept (poll)
%%               > 0  -> wait for timeout ms for accept if no accept then 
%%                       return {error, timeout}
%%
%% ASYNC_ACCEPT(insock(), Timeout)
%%
%%  async accept. return {ok,S,Ref} or {error, Reason}
%%  the owner of socket S will receive an {inet_async,S,Ref,Status} on 
%%  socket condition
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% For TCP sockets only.
%%
accept(L)            -> accept0(L, -1).

accept(L, infinity)  -> accept0(L, -1);
accept(L, Time)      -> accept0(L, Time).

accept0(L, Time) when is_port(L), is_integer(Time) ->
    case async_accept(L, Time) of
	{ok, Ref} ->
	    receive 
		{inet_async, L, Ref, {ok,S}} ->
		    accept_opts(L, S);
		{inet_async, L, Ref, Error} ->
		    Error
	    end;
	Error -> Error
    end.

%% setup options from listen socket on the connected socket
accept_opts(L, S) ->
    case getopts(L, [active, nodelay, keepalive, delay_send, priority, tos]) of
	{ok, Opts} ->
	    case setopts(S, Opts) of
		ok ->
		    case getopts(L, [tclass]) of
			{ok, []} ->
			    {ok, S};
			{ok, TClassOpts} ->
			    case setopts(S, TClassOpts) of
				ok ->
				    {ok, S};
				Error -> close(S), Error
			    end
		    end;
		Error -> close(S), Error
	    end;
	Error ->
	    close(S), Error
    end.

async_accept(L, Time) ->
    case ctl_cmd(L,?INET_REQ_ACCEPT, [enc_time(Time)]) of
	{ok, [R1,R0]} -> {ok, ?u16(R1,R0)};
	{error,_}=Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% LISTEN(insock() [,Backlog]) -> ok | {error, Reason}
%%
%% set listen mode on socket
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% For TCP or SCTP sockets. For SCTP, Boolean backlog value (enable/disable
%% listening) is also accepted:

listen(S) -> listen(S, ?LISTEN_BACKLOG).

listen(S, true) -> listen(S, ?LISTEN_BACKLOG);
listen(S, false) -> listen(S, 0);
listen(S, BackLog) when is_port(S), is_integer(BackLog) ->
    case ctl_cmd(S, ?INET_REQ_LISTEN, [?int16(BackLog)]) of
	{ok, _} -> ok;
	{error,_}=Error   -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% PEELOFF(insock(), AssocId) -> {ok,outsock()} | {error, Reason}
%%
%% SCTP: Peel off one association into a type stream socket
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

peeloff(S, AssocId) ->
    case ctl_cmd(S, ?SCTP_REQ_PEELOFF, [?int32(AssocId)]) of
	inet_reply ->
	    receive
		{inet_reply,S,Res} -> Res
	    end;
	{error,_}=Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SEND(insock(), Data) -> ok | {error, Reason}
%%
%% send Data on the socket (io-list)
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% This is a generic "port_command" interface used by TCP, UDP, SCTP, depending
%% on the driver it is mapped to, and the "Data". It actually sends out data,--
%% NOT delegating this task to any back-end.  For SCTP, this function MUST NOT
%% be called directly -- use "sendmsg" instead:
%%
send(S, Data, OptList) when is_port(S), is_list(OptList) ->
    ?DBG_FORMAT("prim_inet:send(~p, ~p)~n", [S,Data]),
    try erlang:port_command(S, Data, OptList) of
	false -> % Port busy and nosuspend option passed
	    ?DBG_FORMAT("prim_inet:send() -> {error,busy}~n", []),
	    {error,busy};
	true ->
	    receive
		{inet_reply,S,Status} ->
		    ?DBG_FORMAT("prim_inet:send() -> ~p~n", [Status]),
		    Status
	    end
    catch
	error:_Error ->
	    ?DBG_FORMAT("prim_inet:send() -> {error,einval}~n", []),
	     {error,einval}
    end.

send(S, Data) ->
    send(S, Data, []).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SENDTO(insock(), IP, Port, Data) -> ok | {error, Reason}
%%
%% send Datagram to the IP at port (Should add sync send!)
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% "sendto" is for UDP. IP and Port are set by the caller to 0 if the socket
%% is known to be connected.

sendto(S, Addr, _, Data) when is_port(S), tuple_size(Addr) =:= 2 ->
    case type_value(set, addr, Addr) of
	true ->
	    ?DBG_FORMAT("prim_inet:sendto(~p, ~p, ~p)~n", [S,Addr,Data]),
	    try
		erlang:port_command(S, [enc_value(set, addr, Addr),Data])
	    of
		true ->
		    receive
			{inet_reply,S,Reply} ->
			    ?DBG_FORMAT(
			       "prim_inet:sendto() -> ~p~n", [Reply]),
			    Reply
		    end
	    catch
		error:_ ->
		    ?DBG_FORMAT(
		       "prim_inet:sendto() -> {error,einval}~n", []),
		    {error,einval}
	    end;
	false ->
	    ?DBG_FORMAT(
	       "prim_inet:sendto() -> {error,einval}~n", []),
	    {error,einval}
    end;
sendto(S, IP, Port, Data) ->
    sendto(S, {IP, Port}, 0, Data).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SENDMSG(insock(), IP, Port, InitMsg, Data)   or
%% SENDMSG(insock(), SndRcvInfo,        Data)   -> ok | {error, Reason}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% SCTP: Sending data over an existing association: no need for a destination
%% addr; uses SndRcvInfo:
%%
sendmsg(S, #sctp_sndrcvinfo{}=SRI, Data) when is_port(S) ->
    Type = type_opt(set, sctp_default_send_param),
    try type_value(set, Type, SRI) of
	true ->
	    send(S, [enc_value(set, Type, SRI)|Data]);
	false -> {error,einval}
    catch
	Reason -> {error,Reason}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SENDFILE(outsock(), Fd, Offset, Length) -> {ok,BytesSent} | {error, Reason}
%%
%% send Length data bytes from a file handle, to a socket, starting at Offset
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% "sendfile" is for TCP:

sendfile(S, FileHandle, Offset, Length)
        when not is_port(S);
             not is_binary(FileHandle);
             not is_integer(Offset);
             not is_integer(Length) ->
    {error, badarg};
sendfile(S, FileHandle, Offset, Length) ->
    case erlang:port_info(S, connected) of
        {connected, Pid} when Pid =:= self() ->
            sendfile_1(S, FileHandle, Offset, Length);
        {connected, Pid} when Pid =/= self() ->
            {error, not_owner};
        _Other ->
            {error, einval}
    end.

sendfile_1(S, FileHandle, Offset, 0) ->
    sendfile_1(S, FileHandle, Offset, (1 bsl 63) - 1);
sendfile_1(_S, _FileHandle, Offset, Length) when
         Offset < 0; Offset > ((1 bsl 63) - 1);
         Length < 0; Length > ((1 bsl 63) - 1) ->
    {error, einval};
sendfile_1(S, FileHandle, Offset, Length) ->
    Args = [FileHandle,
            ?int64(Offset),
            ?int64(Length)],
    case ctl_cmd(S, ?TCP_REQ_SENDFILE, Args) of
        {ok, []} ->
            receive
                {sendfile, S, {ok, SentLow, SentHigh}} ->
                    {ok, SentLow bor (SentHigh bsl 32)};
                {sendfile, S, {error, Reason}} ->
                    {error, Reason};
                {'EXIT', S, _Reason} ->
                    {error, closed}
            end;
        {error, Reason} ->
            {error, Reason}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% RECV(insock(), Length, [Timeout]) -> {ok,Data} | {error, Reason}
%%
%% receive Length data bytes from a socket
%% if 0 is given then a Data packet is requested (see setopt (packet))
%%    N read N bytes
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% "recv" is for TCP:

recv(S, Length) -> recv0(S, Length, -1).

recv(S, Length, infinity) -> recv0(S, Length,-1);

recv(S, Length, Time) when is_integer(Time) -> recv0(S, Length, Time).

recv0(S, Length, Time) when is_port(S), is_integer(Length), Length >= 0 ->
    case async_recv(S, Length, Time) of
	{ok, Ref} ->
	    receive
		{inet_async, S, Ref, Status} -> Status;
		{'EXIT', S, _Reason} ->
		    {error, closed}
	    end;
	Error -> Error
    end.
	     

async_recv(S, Length, Time) ->
    case ctl_cmd(S, ?TCP_REQ_RECV, [enc_time(Time), ?int32(Length)]) of
	{ok,[R1,R0]} -> {ok, ?u16(R1,R0)};
	{error,_}=Error -> Error
    end.	    

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% RECVFROM(insock(), Lenth [Timeout]) -> {ok,{IP,Port,Data}} | {error, Reason}
%%                           For SCTP: -> {ok,{IP,Port,[AncData],Data}}
%%                                                            | {error, Reason}
%% receive Length data bytes from a datagram socket sent from IP at Port
%% if 0 is given then a Data packet is requested (see setopt (packet))
%%    N read N bytes
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% "recvfrom" is for both UDP and SCTP.
%% NB: "Length" is actually ignored for these protocols, since they are msg-
%% oriented: preserved here only for API compatibility.
%%
recvfrom(S, Length) ->
    recvfrom(S, Length, infinity).

recvfrom(S, Length, infinity) when is_port(S) ->
    recvfrom0(S, Length, -1);
recvfrom(S, Length, Time) when is_port(S) ->
    if
	is_integer(Time), 0 =< Time, Time < 16#ffffffff ->
	    recvfrom0(S, Length, Time);
	true ->
	    {error, einval}
    end.

recvfrom0(S, Length, Time)
  when is_integer(Length), 0 =< Length, Length =< 16#ffffffff ->
    case ctl_cmd(S, ?PACKET_REQ_RECV,[enc_time(Time),?int32(Length)]) of
	{ok,[R1,R0]} ->
	    Ref = ?u16(R1,R0),
	    receive
		% Success, UDP:
		{inet_async, S, Ref, {ok, [F | AddrData]}} ->
		    case get_addr(F, AddrData) of
			{{Family, _} = Addr, Data} when is_atom(Family) ->
			    {ok, {Addr, 0, Data}};
			{{IP, Port}, Data} ->
			    {ok, {IP, Port, Data}}
		    end;

		% Success, SCTP:
		{inet_async, S, Ref, {ok, {[F,P1,P0 | Addr], AncData, DE}}} ->
		    {IP, _} = get_ip(F, Addr),
		    {ok, {IP, ?u16(P1, P0), AncData, DE}};

		% Back-end error:
		{inet_async, S, Ref, Error={error, _}} ->
		    Error
	    end;
	{error,_}=Error ->
	    Error % Front-end error
    end;
recvfrom0(_, _, _) -> {error,einval}.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% PEERNAME(insock()) -> {ok, {IP, Port}} | {error, Reason}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

peername(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_PEER, []) of
	{ok, [F | Addr]} ->
	    {A, _} = get_addr(F, Addr),
	    {ok, A};
	{error, _} = Error -> Error
    end.

setpeername(S, undefined) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_SETPEER, []) of
	{ok, []} -> ok;
	{error, _} = Error -> Error
    end;
setpeername(S, Addr) when is_port(S) ->
    case type_value(set, addr, Addr) of
	true ->
	    case ctl_cmd(S, ?INET_REQ_SETPEER, enc_value(set, addr, Addr)) of
		{ok, []} -> ok;
		{error, _} = Error -> Error
	    end;
	false ->
	    {error, einval}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% PEERNAMES(insock()) -> {ok, [{IP, Port}, ...]} | {error, Reason}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

peernames(S) when is_port(S) ->
    peernames(S, undefined).

peernames(S, #sctp_assoc_change{assoc_id=AssocId}) when is_port(S) ->
    peernames(S, AssocId);
peernames(S, AssocId)
  when is_port(S), is_integer(AssocId);
       is_port(S), AssocId =:= undefined ->
    Q = get,
    Type = [[sctp_assoc_id,0]],
    case type_value(Q, Type, AssocId) of
	true ->
	    case ctl_cmd
		(S, ?INET_REQ_GETPADDRS,
		 enc_value(Q, Type, AssocId)) of
		{ok,Addrs} ->
		    {ok,get_addrs(Addrs)};
		Error ->
		    Error
	    end;
	false ->
	    {error,einval}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SOCKNAME(insock()) -> {ok, {IP, Port}} | {error, Reason}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

sockname(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_NAME, []) of
	{ok, [F | Addr]} ->
	    {A, _} = get_addr(F, Addr),
	    {ok, A};
	{error, _} = Error -> Error
    end.

setsockname(S, undefined) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_SETNAME, []) of
	{ok, []} -> ok;
	{error, _} = Error -> Error
    end;
setsockname(S, Addr) when is_port(S) ->
    case type_value(set, addr, Addr) of
	true ->
	    case
		ctl_cmd(S, ?INET_REQ_SETNAME, enc_value(set, addr, Addr))
	    of
		{ok, []} -> ok;
		{error, _} = Error -> Error
	    end;
	false ->
	    {error, einval}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SOCKNAMES(insock()) -> {ok, [{IP, Port}, ...]} | {error, Reason}
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

socknames(S) when is_port(S) ->
    socknames(S, undefined).

socknames(S, #sctp_assoc_change{assoc_id=AssocId}) when is_port(S) ->
    socknames(S, AssocId);
socknames(S, AssocId)
  when is_port(S), is_integer(AssocId);
       is_port(S), AssocId =:= undefined ->
    Q = get,
    Type = [[sctp_assoc_id,0]],
    case type_value(Q, Type, AssocId) of
	true ->
	    case ctl_cmd
		(S, ?INET_REQ_GETLADDRS,
		 enc_value(Q, Type, AssocId)) of
		{ok,Addrs} ->
		    {ok,get_addrs(Addrs)};
		Error ->
		    Error
	    end;
	false ->
	    {error,einval}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% SETOPT(insock(), Opt, Value) -> ok | {error, Reason}
%% SETOPTS(insock(), [{Opt,Value}]) -> ok | {error, Reason}
%%
%% set socket, ip and driver option
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

setopt(S, Opt, Value) when is_port(S) -> 
    setopts(S, [{Opt,Value}]).

setopts(S, Opts) when is_port(S) ->
    case encode_opt_val(Opts) of
	{ok, Buf} ->
	    case ctl_cmd(S, ?INET_REQ_SETOPTS, Buf) of
		{ok, _} -> ok;
		{error,_}=Error -> Error
	    end;
	Error  -> Error
    end.	    

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETOPT(insock(), Opt) -> {ok,Value} | {error, Reason}
%% GETOPTS(insock(), [Opt]) -> {ok, [{Opt,Value}]} | {error, Reason}
%% get socket, ip and driver option
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getopt(S, Opt) when is_port(S), is_atom(Opt) ->
    case getopts(S, [Opt]) of
	{ok,[{_,Value}]} -> {ok, Value};
	Error -> Error
    end.

getopts(S, Opts) when is_port(S), is_list(Opts) ->
    case encode_opts(Opts) of
	{ok,Buf} ->
	    case ctl_cmd(S, ?INET_REQ_GETOPTS, Buf) of
		{ok,Rep} ->
		    %% Non-SCTP: "Rep" contains the encoded option vals:
		    decode_opt_val(Rep);
		inet_reply ->
		    %% SCTP: Need to receive the full value:
		    receive
			{inet_reply,S,Res} -> Res
		    end;
		{error,_}=Error -> Error
	    end;
	Error -> Error
    end.
    
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% CHGOPT(insock(), Opt) -> {ok,Value} | {error, Reason}
%% CHGOPTS(insock(), [Opt]) -> {ok, [{Opt,Value}]} | {error, Reason}
%% change socket, ip and driver option
%%
%% Same as setopts except for record value options where undefined
%% fields are read with getopts before setting.
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

chgopt(S, Opt, Value) when is_port(S) -> 
    chgopts(S, [{Opt,Value}]).

chgopts(S, Opts) when is_port(S), is_list(Opts) ->
    case getopts(S, need_template(Opts)) of
	{ok,Templates} ->
	    try merge_options(Opts, Templates) of
		NewOpts ->
		    setopts(S, NewOpts)
	    catch
		Reason -> {error,Reason}
	    end;
	Error -> Error
    end.
    
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% getifaddrs(insock()) -> {ok,IfAddrsList} | {error, Reason}
%%
%%   IfAddrsList = [{Name,[Opts]}]
%%   Name = string()
%%   Opts = {flags,[Flag]} | {addr,Addr} | {netmask,Addr} | {broadaddr,Addr}
%%        | {dstaddr,Addr} | {hwaddr,HwAddr} | {mtu,integer()}
%%   Flag = up | broadcast | loopback | running | multicast
%%   Addr = ipv4addr() | ipv6addr()
%%   HwAddr = ethernet_addr()
%%
%% get interface name and addresses list
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getifaddrs(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_GETIFADDRS, []) of
	{ok, Data} ->
	    {ok, comp_ifaddrs(build_ifaddrs(Data), ktree_empty())};
	{error,enotsup} ->
	    case getiflist(S) of
		{ok, IFs} ->
		    {ok, getifaddrs_ifget(S, IFs)};
		Err1 -> Err1
	    end;
	Err2 -> Err2
    end.

%% Restructure interface properties per interface and remove duplicates

comp_ifaddrs([{If,Opts}|IfOpts], T) ->
    case ktree_is_defined(If, T) of
	true ->
	    OptSet = comp_ifaddrs_add(ktree_get(If, T), Opts),
	    comp_ifaddrs(IfOpts, ktree_update(If, OptSet, T));
	false ->
	    OptSet = comp_ifaddrs_add(ktree_empty(), Opts),
	    comp_ifaddrs(IfOpts, ktree_insert(If, OptSet, T))
     end;
comp_ifaddrs([], T) ->
    [{If,ktree_keys(ktree_get(If, T))} || If <- ktree_keys(T)].

comp_ifaddrs_add(OptSet, [Opt|Opts]) ->
    case ktree_is_defined(Opt, OptSet) of
	true
	  when element(1, Opt) =:= flags;
	       element(1, Opt) =:= hwaddr ->
	    comp_ifaddrs_add(OptSet, Opts);
	_ ->
	    comp_ifaddrs_add(ktree_insert(Opt, undefined, OptSet), Opts)
    end;
comp_ifaddrs_add(OptSet, []) -> OptSet.

%% Legacy emulation of getifaddrs

getifaddrs_ifget(_, []) -> [];
getifaddrs_ifget(S, [IF|IFs]) ->
    case ifget(S, IF, [flags]) of
	{ok,[{flags,Flags}]=FlagsVals} ->
	    BroadOpts =
		case member(broadcast, Flags) of
		    true ->
			[broadaddr,hwaddr];
		    false ->
			[hwaddr]
		end,
	    P2POpts =
		case member(pointtopoint, Flags) of
		    true ->
			[dstaddr|BroadOpts];
		    false ->
			BroadOpts
		end,
	    getifaddrs_ifget(S, IFs, IF, FlagsVals, [addr,netmask|P2POpts]);
	_ ->
	    getifaddrs_ifget(S, IFs, IF, [], [addr,netmask,hwaddr])
    end.

getifaddrs_ifget(S, IFs, IF, FlagsVals, Opts) ->
    OptVals =
	case ifget(S, IF, Opts) of
	    {ok,OVs} -> OVs;
	    _ -> []
	end,
    [{IF,FlagsVals++OptVals}|getifaddrs_ifget(S, IFs)].

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% getiflist(insock()) -> {ok,IfNameList} | {error, Reason}
%%
%% get interface name list
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getiflist(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_GETIFLIST, []) of
	{ok, Data} -> {ok, build_iflist(Data)};
	{error,_}=Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% ifget(insock(), IFOpts) -> {ok,IfNameList} | {error, Reason}
%%
%% get interface name list
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

ifget(S, Name, Opts) ->
    case encode_ifname(Name) of
	{ok, Buf1} ->
	    case encode_ifopts(Opts,[]) of
		{ok, Buf2} ->
		    case ctl_cmd(S, ?INET_REQ_IFGET, [Buf1,Buf2]) of
			{ok, Data} -> decode_ifopts(Data,[]);
			{error,_}=Error -> Error
		    end;
		Error -> Error
	    end;
	Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% ifset(insock(), Name, IFOptVals) -> {ok,IfNameList} | {error, Reason}
%%
%% set interface parameters
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

ifset(S, Name, Opts) ->
    case encode_ifname(Name) of
	{ok, Buf1} ->
	    case encode_ifopt_val(Opts,[]) of
		{ok, Buf2} ->
		    case ctl_cmd(S, ?INET_REQ_IFSET, [Buf1,Buf2]) of
			{ok, _} -> ok;
			{error,_}=Error -> Error
		    end;
		Error -> Error
	    end;
	Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% subscribe(insock(), SubsList) -> {ok,StatReply} | {error, Reason}
%%
%% Subscribe on socket events (from driver)
%%
%% Available event subscriptions:
%%   subs_empty_out_q: StatReply = [{subs_empty_out_q, N}], where N
%%                     is current queue length. When the queue becomes empty
%%                     a {empty_out_q, insock()} message will be sent to
%%                     subscribing process and the subscription will be
%%                     removed. If N = 0, the queue is empty and no
%%                     subscription is made.
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

subscribe(S, Sub) when is_port(S), is_list(Sub) ->
    case encode_subs(Sub) of
	{ok, Bytes} ->
	    case ctl_cmd(S, ?INET_REQ_SUBSCRIBE, Bytes) of
		{ok, Data} -> decode_subs(Data);
		{error,_}=Error -> Error
	    end;
	Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETSTAT(insock(), StatList) -> {ok,StatReply} | {error, Reason}
%%
%% get socket statistics (from driver)
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getstat(S, Stats) when is_port(S), is_list(Stats) ->
    case encode_stats(Stats) of
	{ok, Bytes} ->
	    case ctl_cmd(S, ?INET_REQ_GETSTAT, Bytes) of
		{ok, Data} -> decode_stats(Data);
		{error,_}=Error -> Error
	    end;
	Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETFD(insock()) -> {ok,integer()} | {error, Reason}
%%
%% get internal file descriptor
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getfd(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_GETFD, []) of
	{ok, [S3,S2,S1,S0]} -> {ok, ?u32(S3,S2,S1,S0)};
	{error,_}=Error -> Error
    end.        

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% IGNOREFD(insock(),boolean()) -> {ok,integer()} | {error, Reason}
%%
%% steal internal file descriptor
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

ignorefd(S,Bool) when is_port(S) ->
    Val = if Bool -> 1; true -> 0 end,
    case ctl_cmd(S, ?INET_REQ_IGNOREFD, [Val]) of
	{ok, _} -> ok;
	Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETIX(insock()) -> {ok,integer()} | {error, Reason}
%%
%% get internal socket index
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getindex(S) when is_port(S) ->
    %% NOT USED ANY MORE
    {error, einval}.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETTYPE(insock()) -> {ok,{Family,Type}} | {error, Reason}
%%
%% get family/type of a socket
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

gettype(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_GETTYPE, []) of
	{ok, [F3,F2,F1,F0,T3,T2,T1,T0]} ->
	    Family = case ?u32(F3,F2,F1,F0) of
			 ?INET_AF_INET  ->  inet;
			 ?INET_AF_INET6 ->  inet6;
			 _ -> undefined
		     end,
	    Type = case ?u32(T3,T2,T1,T0) of
			?INET_TYPE_STREAM    -> stream;
			?INET_TYPE_DGRAM     -> dgram;
			?INET_TYPE_SEQPACKET -> seqpacket;
			_		     -> undefined
		   end,
	    {ok, {Family, Type}};
	{error,_}=Error -> Error
    end.

getprotocol(S) when is_port(S) ->
    {name,Drv} = erlang:port_info(S, name),
    drv2protocol(Drv).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%  IS_SCTP(insock()) -> true | false
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% is_sctp(S) when is_port(S) ->
%%     case gettype(S) of
%% 	{ok, {_, seqpacket}} -> true;
%% 	_		     -> false
%%     end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETSTATUS(insock()) -> {ok,Status} | {error, Reason}
%%
%% get socket status
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getstatus(S) when is_port(S) ->
    case ctl_cmd(S, ?INET_REQ_GETSTATUS, []) of
	{ok, [S3,S2,S1,S0]} ->	
	    {ok, dec_status(?u32(S3,S2,S1,S0))};
	{error,_}=Error -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETHOSTNAME(insock()) -> {ok,HostName} | {error, Reason}
%%
%% get host name
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

gethostname(S) when is_port(S) ->
    ctl_cmd(S, ?INET_REQ_GETHOSTNAME, []).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETSERVBYNAME(insock(),Name,Proto) -> {ok,Port} | {error, Reason}
%%
%% get service port
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getservbyname(S,Name,Proto) when is_port(S), is_atom(Name), is_atom(Proto) ->
    getservbyname1(S, atom_to_list(Name), atom_to_list(Proto));
getservbyname(S,Name,Proto) when is_port(S), is_atom(Name), is_list(Proto) ->
    getservbyname1(S, atom_to_list(Name), Proto);
getservbyname(S,Name,Proto) when is_port(S), is_list(Name), is_atom(Proto) ->
    getservbyname1(S, Name, atom_to_list(Proto));
getservbyname(S,Name,Proto) when is_port(S), is_list(Name), is_list(Proto) ->
    getservbyname1(S, Name, Proto);
getservbyname(_,_, _) ->
    {error, einval}.

getservbyname1(S,Name,Proto) ->
    L1 = length(Name),
    L2 = length(Proto),
    if L1 > 255 -> {error, einval};
       L2 > 255 -> {error, einval};
       true ->
	    case ctl_cmd(S, ?INET_REQ_GETSERVBYNAME, [L1,Name,L2,Proto]) of
		{ok, [P1,P0]} ->
		    {ok, ?u16(P1,P0)};
		{error,_}=Error ->
		    Error
	    end
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% GETSERVBYPORT(insock(),Port,Proto) -> {ok,Port} | {error, Reason}
%%
%% get service port from portnumber and protocol
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

getservbyport(S,Port,Proto) when is_port(S), is_atom(Proto) ->
    getservbyport1(S, Port, atom_to_list(Proto));
getservbyport(S,Port,Proto) when is_port(S), is_list(Proto) ->
    getservbyport1(S, Port, Proto);
getservbyport(_, _, _) ->
    {error, einval}.

getservbyport1(S,Port,Proto) ->
    L = length(Proto),
    if Port < 0 -> {error, einval};
       Port > 16#ffff -> {error, einval};
       L > 255 -> {error, einval};
       true ->
	    case ctl_cmd(S, ?INET_REQ_GETSERVBYPORT, [?int16(Port),L,Proto]) of
		{ok, Name} -> {ok, Name};
		{error,_}=Error -> Error
	    end
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% 
%% UNRECV(insock(), data) -> ok | {error, Reason}
%%
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

unrecv(S, Data) ->
    case ctl_cmd(S, ?TCP_REQ_UNRECV, Data) of
	{ok, _} -> ok;
	{error,_}=Error  -> Error
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% DETACH(insock()) -> ok
%%
%%   unlink from a socket 
%%
%% ATTACH(insock()) -> ok | {error, Reason}
%%
%%   link and connect to a socket 
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

detach(S) when is_port(S) ->
    unlink(S),
    ok.

attach(S) when is_port(S) ->
    try erlang:port_connect(S, self()) of
	true -> link(S), ok
    catch
	error:Reason -> {error,Reason}
    end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% INTERNAL FUNCTIONS
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

is_sockopt_val(Opt, Val) ->
    Type = type_opt(set, Opt),
    try type_value(set, Type, Val)
    catch
	_ -> false
    end.

%%
%% Socket options processing: Encoding option NAMES:
%%
enc_opt(reuseaddr)       -> ?INET_OPT_REUSEADDR;
enc_opt(keepalive)       -> ?INET_OPT_KEEPALIVE;
enc_opt(dontroute)       -> ?INET_OPT_DONTROUTE;
enc_opt(linger)          -> ?INET_OPT_LINGER;
enc_opt(broadcast)       -> ?INET_OPT_BROADCAST;
enc_opt(sndbuf)          -> ?INET_OPT_SNDBUF;
enc_opt(recbuf)          -> ?INET_OPT_RCVBUF;
enc_opt(priority)        -> ?INET_OPT_PRIORITY;
enc_opt(tos)             -> ?INET_OPT_TOS;
enc_opt(tclass)          -> ?INET_OPT_TCLASS;
enc_opt(nodelay)         -> ?TCP_OPT_NODELAY;
enc_opt(multicast_if)    -> ?UDP_OPT_MULTICAST_IF;
enc_opt(multicast_ttl)   -> ?UDP_OPT_MULTICAST_TTL;
enc_opt(multicast_loop)  -> ?UDP_OPT_MULTICAST_LOOP;
enc_opt(add_membership)  -> ?UDP_OPT_ADD_MEMBERSHIP;
enc_opt(drop_membership) -> ?UDP_OPT_DROP_MEMBERSHIP;
enc_opt(ipv6_v6only)     -> ?INET_OPT_IPV6_V6ONLY;
enc_opt(buffer)          -> ?INET_LOPT_BUFFER;
enc_opt(header)          -> ?INET_LOPT_HEADER;
enc_opt(active)          -> ?INET_LOPT_ACTIVE;
enc_opt(packet)          -> ?INET_LOPT_PACKET;
enc_opt(mode)            -> ?INET_LOPT_MODE;
enc_opt(deliver)         -> ?INET_LOPT_DELIVER;
enc_opt(exit_on_close)   -> ?INET_LOPT_EXITONCLOSE;
enc_opt(high_watermark)  -> ?INET_LOPT_TCP_HIWTRMRK;
enc_opt(low_watermark)   -> ?INET_LOPT_TCP_LOWTRMRK;
enc_opt(high_msgq_watermark)  -> ?INET_LOPT_MSGQ_HIWTRMRK;
enc_opt(low_msgq_watermark)   -> ?INET_LOPT_MSGQ_LOWTRMRK;
enc_opt(send_timeout)    -> ?INET_LOPT_TCP_SEND_TIMEOUT;
enc_opt(send_timeout_close) -> ?INET_LOPT_TCP_SEND_TIMEOUT_CLOSE;
enc_opt(delay_send)      -> ?INET_LOPT_TCP_DELAY_SEND;
enc_opt(packet_size)     -> ?INET_LOPT_PACKET_SIZE;
enc_opt(read_packets)    -> ?INET_LOPT_READ_PACKETS;
enc_opt(netns)           -> ?INET_LOPT_NETNS;
enc_opt(show_econnreset) -> ?INET_LOPT_TCP_SHOW_ECONNRESET;
enc_opt(line_delimiter)  -> ?INET_LOPT_LINE_DELIM;
enc_opt(raw)             -> ?INET_OPT_RAW;
enc_opt(bind_to_device)  -> ?INET_OPT_BIND_TO_DEVICE;
% Names of SCTP opts:
enc_opt(sctp_rtoinfo)	 	   -> ?SCTP_OPT_RTOINFO;
enc_opt(sctp_associnfo)	 	   -> ?SCTP_OPT_ASSOCINFO;
enc_opt(sctp_initmsg)	 	   -> ?SCTP_OPT_INITMSG;
enc_opt(sctp_autoclose)	 	   -> ?SCTP_OPT_AUTOCLOSE;
enc_opt(sctp_nodelay)		   -> ?SCTP_OPT_NODELAY;
enc_opt(sctp_disable_fragments)	   -> ?SCTP_OPT_DISABLE_FRAGMENTS;
enc_opt(sctp_i_want_mapped_v4_addr)-> ?SCTP_OPT_I_WANT_MAPPED_V4_ADDR;
enc_opt(sctp_maxseg)		   -> ?SCTP_OPT_MAXSEG;
enc_opt(sctp_set_peer_primary_addr)-> ?SCTP_OPT_SET_PEER_PRIMARY_ADDR;
enc_opt(sctp_primary_addr)	   -> ?SCTP_OPT_PRIMARY_ADDR;
enc_opt(sctp_adaptation_layer)	   -> ?SCTP_OPT_ADAPTATION_LAYER;
enc_opt(sctp_peer_addr_params)	   -> ?SCTP_OPT_PEER_ADDR_PARAMS;
enc_opt(sctp_default_send_param)   -> ?SCTP_OPT_DEFAULT_SEND_PARAM;
enc_opt(sctp_events)		   -> ?SCTP_OPT_EVENTS;
enc_opt(sctp_delayed_ack_time)	   -> ?SCTP_OPT_DELAYED_ACK_TIME;
enc_opt(sctp_status)		   -> ?SCTP_OPT_STATUS;
enc_opt(sctp_get_peer_addr_info)   -> ?SCTP_OPT_GET_PEER_ADDR_INFO.
%%

%%
%% Decoding option NAMES:
%%
dec_opt(?INET_OPT_REUSEADDR)      -> reuseaddr;
dec_opt(?INET_OPT_KEEPALIVE)      -> keepalive;
dec_opt(?INET_OPT_DONTROUTE)      -> dontroute;
dec_opt(?INET_OPT_LINGER)         -> linger;
dec_opt(?INET_OPT_BROADCAST)      -> broadcast;
dec_opt(?INET_OPT_SNDBUF)         -> sndbuf;
dec_opt(?INET_OPT_RCVBUF)         -> recbuf;
dec_opt(?INET_OPT_PRIORITY)       -> priority;
dec_opt(?INET_OPT_TOS)            -> tos;
dec_opt(?INET_OPT_TCLASS)         -> tclass;
dec_opt(?TCP_OPT_NODELAY)         -> nodelay;
dec_opt(?UDP_OPT_MULTICAST_IF)    -> multicast_if;
dec_opt(?UDP_OPT_MULTICAST_TTL)   -> multicast_ttl;
dec_opt(?UDP_OPT_MULTICAST_LOOP)  -> multicast_loop;
dec_opt(?UDP_OPT_ADD_MEMBERSHIP)  -> add_membership;
dec_opt(?UDP_OPT_DROP_MEMBERSHIP) -> drop_membership;
dec_opt(?INET_OPT_IPV6_V6ONLY)    -> ipv6_v6only;
dec_opt(?INET_LOPT_BUFFER)        -> buffer;
dec_opt(?INET_LOPT_HEADER)        -> header;
dec_opt(?INET_LOPT_ACTIVE)        -> active;
dec_opt(?INET_LOPT_PACKET)        -> packet;
dec_opt(?INET_LOPT_MODE)          -> mode;
dec_opt(?INET_LOPT_DELIVER)       -> deliver;
dec_opt(?INET_LOPT_EXITONCLOSE)   -> exit_on_close;
dec_opt(?INET_LOPT_TCP_HIWTRMRK)  -> high_watermark;
dec_opt(?INET_LOPT_TCP_LOWTRMRK)  -> low_watermark;
dec_opt(?INET_LOPT_MSGQ_HIWTRMRK)  -> high_msgq_watermark;
dec_opt(?INET_LOPT_MSGQ_LOWTRMRK)  -> low_msgq_watermark;
dec_opt(?INET_LOPT_TCP_SEND_TIMEOUT) -> send_timeout;
dec_opt(?INET_LOPT_TCP_SEND_TIMEOUT_CLOSE) -> send_timeout_close;
dec_opt(?INET_LOPT_TCP_DELAY_SEND)   -> delay_send;
dec_opt(?INET_LOPT_PACKET_SIZE)      -> packet_size;
dec_opt(?INET_LOPT_READ_PACKETS)     -> read_packets;
dec_opt(?INET_LOPT_NETNS)           -> netns;
dec_opt(?INET_LOPT_TCP_SHOW_ECONNRESET) -> show_econnreset;
dec_opt(?INET_LOPT_LINE_DELIM)      -> line_delimiter;
dec_opt(?INET_OPT_RAW)              -> raw;
dec_opt(?INET_OPT_BIND_TO_DEVICE) -> bind_to_device;
dec_opt(I) when is_integer(I)     -> undefined.



%% Metatypes:
%% []              Value must be 'undefined' or nonexistent
%%                 for setopts and getopts.
%% [Type]          Value required for setopts and getopts,
%%                 will be encoded for both.
%% [Type,Default]  Default used if value is 'undefined'.
%% [[Type,Default]] A combination of the two above.
%% Type            Value must be 'undefined' or nonexistent for getops,
%%                 required for setopts.
%%
%% The use of [] and [[Type,Default]] is commented out in enc_value/2
%% and type_value/2 below since they are only used in record fields.
%% And record fields does not call enc_value/2 nor type_value/2.
%% Anyone introducing these metatypes otherwhere will have to activate
%% those clauses in enc_value/2 and type_value/2. You have been warned!

type_opt(get, raw) -> [{[int],[int],[binary_or_uint]}];
type_opt(_,   raw) -> {int,int,binary};
%% NB: "sctp_status" and "sctp_get_peer_addr_info" are read-only options,
%% so they should not be NOT encoded for use with "setopt".
type_opt(get, sctp_status) ->
    [{record,#sctp_status{
	assoc_id = [sctp_assoc_id],
	_        = []}}];
type_opt(get, sctp_get_peer_addr_info) ->
    [{record,#sctp_paddrinfo{
	assoc_id = [[sctp_assoc_id,0]],
	address  = [[addr,{any,0}]],
	_        = []}}];
type_opt(_,   Opt) ->
    type_opt_1(Opt).

%% Types of option values, by option name:
%%
type_opt_1(reuseaddr)       -> bool;
type_opt_1(keepalive)       -> bool;
type_opt_1(dontroute)       -> bool;
type_opt_1(linger)          -> {bool,int};
type_opt_1(broadcast)       -> bool;
type_opt_1(sndbuf)          -> int;
type_opt_1(recbuf)          -> int;
type_opt_1(priority)        -> int;
type_opt_1(tos)             -> int;
type_opt_1(tclass)          -> int;
type_opt_1(nodelay)         -> bool;
type_opt_1(ipv6_v6only)     -> bool;
%% multicast
type_opt_1(multicast_ttl)   -> int;
type_opt_1(multicast_loop)  -> bool;
type_opt_1(multicast_if)    -> ip;
type_opt_1(add_membership)  -> {ip,ip};
type_opt_1(drop_membership) -> {ip,ip};
%% driver options
type_opt_1(header)          -> uint;
type_opt_1(buffer)          -> int;
type_opt_1(active) ->
    {enum,[{false, ?INET_PASSIVE}, 
	   {true, ?INET_ACTIVE}, 
	   {once, ?INET_ONCE},
           {multi, ?INET_MULTI}]};
type_opt_1(packet) -> 
    {enum,[{0, ?TCP_PB_RAW},
	   {1, ?TCP_PB_1},
	   {2, ?TCP_PB_2},
	   {4, ?TCP_PB_4},
	   {raw,?TCP_PB_RAW},
	   {sunrm, ?TCP_PB_RM},
	   {asn1, ?TCP_PB_ASN1},
	   {cdr, ?TCP_PB_CDR},
	   {fcgi, ?TCP_PB_FCGI},
	   {line, ?TCP_PB_LINE_LF},
	   {tpkt, ?TCP_PB_TPKT},
	   {http, ?TCP_PB_HTTP},
	   {httph,?TCP_PB_HTTPH},
	   {http_bin, ?TCP_PB_HTTP_BIN},
	   {httph_bin,?TCP_PB_HTTPH_BIN},
	   {ssl, ?TCP_PB_SSL_TLS}, % obsolete
	   {ssl_tls, ?TCP_PB_SSL_TLS}]};
type_opt_1(line_delimiter)  -> int;
type_opt_1(mode) ->
    {enum,[{list, ?INET_MODE_LIST},
	   {binary, ?INET_MODE_BINARY}]};
type_opt_1(deliver) ->
    {enum,[{port, ?INET_DELIVER_PORT},
	   {term, ?INET_DELIVER_TERM}]};
type_opt_1(exit_on_close)   -> bool;
type_opt_1(low_watermark)   -> int;
type_opt_1(high_watermark)  -> int;
type_opt_1(low_msgq_watermark)   -> int;
type_opt_1(high_msgq_watermark)  -> int;
type_opt_1(send_timeout)    -> time;
type_opt_1(send_timeout_close) -> bool;
type_opt_1(delay_send)      -> bool;
type_opt_1(packet_size)     -> uint;
type_opt_1(read_packets)    -> uint;
type_opt_1(netns)           -> binary;
type_opt_1(show_econnreset) -> bool;
type_opt_1(bind_to_device)  -> binary;
%% 
%% SCTP options (to be set). If the type is a record type, the corresponding
%% record signature is returned, otherwise, an "elementary" type tag 
%% is returned:
%% 
%% for SCTP_OPT_RTOINFO
type_opt_1(sctp_rtoinfo) ->
    [{record,#sctp_rtoinfo{
	assoc_id = [[sctp_assoc_id,0]],
	initial  = [uint32,0],
	max      = [uint32,0],
	min      = [uint32,0]}}];
%% for SCTP_OPT_ASSOCINFO
type_opt_1(sctp_associnfo) ->
    [{record,#sctp_assocparams{
	assoc_id                 = [[sctp_assoc_id,0]],
	asocmaxrxt               = [uint16,0],
	number_peer_destinations = [uint16,0],
	peer_rwnd                = [uint32,0],
	local_rwnd               = [uint32,0],
	cookie_life              = [uint32,0]}}];
%% for SCTP_OPT_INITMSG and SCTP_TAG_SEND_ANC_INITMSG (send*)
type_opt_1(sctp_initmsg) ->
    [{record,#sctp_initmsg{
	num_ostreams   = [uint16,0],
	max_instreams  = [uint16,0],
	max_attempts   = [uint16,0],
	max_init_timeo = [uint16,0]}}];
%%
type_opt_1(sctp_nodelay)	       -> bool;
type_opt_1(sctp_autoclose)	       -> uint;
type_opt_1(sctp_disable_fragments)     -> bool;
type_opt_1(sctp_i_want_mapped_v4_addr) -> bool;
type_opt_1(sctp_maxseg)		       -> uint;
%% for SCTP_OPT_PRIMARY_ADDR
type_opt_1(sctp_primary_addr) ->
    [{record,#sctp_prim{
	assoc_id = [sctp_assoc_id],
	addr     = addr}}];
%% for SCTP_OPT_SET_PEER_PRIMARY_ADDR
type_opt_1(sctp_set_peer_primary_addr) ->
    [{record,#sctp_setpeerprim{
	assoc_id = [sctp_assoc_id],
	addr     = addr}}];
%% for SCTP_OPT_ADAPTATION_LAYER
type_opt_1(sctp_adaptation_layer) ->
    [{record,#sctp_setadaptation{
	adaptation_ind = [uint32,0]}}];
%% for SCTP_OPT_PEER_ADDR_PARAMS
type_opt_1(sctp_peer_addr_params) ->
    [{record,#sctp_paddrparams{
	assoc_id          = [[sctp_assoc_id,0]],
	address           = [[addr,{any,0}]],
	hbinterval        = [uint32,0],
	pathmaxrxt        = [uint16,0],
	pathmtu           = [uint32,0],
	sackdelay         = [uint32,0],
	flags             =
	[{bitenumlist,
	  [{hb_enable,         ?SCTP_FLAG_HB_ENABLE},
	   {hb_disable,        ?SCTP_FLAG_HB_DISABLE},
	   {hb_demand,         ?SCTP_FLAG_HB_DEMAND},
	   {pmtud_enable,      ?SCTP_FLAG_PMTUD_ENABLE},
	   {pmtud_disable,     ?SCTP_FLAG_PMTUD_DISABLE},
	   {sackdelay_enable,  ?SCTP_FLAG_SACKDELAY_ENABLE},
	   {sackdelay_disable, ?SCTP_FLAG_SACKDELAY_DISABLE}],
	  uint32},[]]}}];
%% for SCTP_OPT_DEFAULT_SEND_PARAM and SCTP_TAG_SEND_ANC_PARAMS (on send*)
type_opt_1(sctp_default_send_param) ->
    [{record,#sctp_sndrcvinfo{
	stream            = [uint16,0],
	ssn               = [],
	flags             =
	[{bitenumlist,
	  [{unordered,  ?SCTP_FLAG_UNORDERED},
	   {addr_over,  ?SCTP_FLAG_ADDR_OVER},
	   {abort,      ?SCTP_FLAG_ABORT},
	   {eof,        ?SCTP_FLAG_EOF}],
	  uint16},[]],
	ppid              = [uint32,0],
	context           = [uint32,0],
	timetolive        = [uint32,0],
	tsn               = [],
	cumtsn            = [],
	assoc_id          = [[sctp_assoc_id,0]]}}];
%% for SCTP_OPT_EVENTS
type_opt_1(sctp_events) ->
    [{record,#sctp_event_subscribe{
	data_io_event          = [bool8,true],
        association_event      = [bool8,true], 
	address_event          = [bool8,true], 
	send_failure_event     = [bool8,true], 
	peer_error_event       = [bool8,true], 
	shutdown_event         = [bool8,true], 
	partial_delivery_event = [bool8,true], 
	adaptation_layer_event = [bool8,false],
	authentication_event   = [bool8,false]}}];
%% for SCTP_OPT_DELAYED_ACK_TIME
type_opt_1(sctp_delayed_ack_time) ->
    [{record,#sctp_assoc_value{
	assoc_id    = [[sctp_assoc_id,0]],
	assoc_value = [uint32,0]}}];
%%
type_opt_1(undefined)         -> undefined;
type_opt_1(O) when is_atom(O) -> undefined.



%% Get. No supplied value.
type_value(get, undefined)        -> false; % Undefined type
%% These two clauses can not happen since they are only used
%% in record fields - from record fields they must have a
%% value though it might be 'undefined', so record fields
%% calls type_value/3, not type_value/2.
%% type_value(get, [])               -> true;  % Ignored
%% type_value(get, [[Type,Default]]) ->        % Required field, default value
%%     type_value(get, Type, Default);
type_value(get, [{record,Types}]) ->        % Implied default value for record
    type_value_record(get, Types, 
		      erlang:make_tuple(tuple_size(Types), undefined), 2);
type_value(get, [_])              -> false; % Required value missing
type_value(get, _)                -> true.  % Field is supposed to be undefined

%% Get and set. Value supplied.
type_value(_, undefined, _)   -> false;     % Undefined type
type_value(_, [], undefined)  -> true;      % Ignored
type_value(_, [], _)          -> false;     % Value should not be supplied
type_value(Q, [Type], Value)  ->            % Required field, proceed
    type_value_default(Q, Type, Value);
type_value(set, Type, Value)  ->            % Required for setopts
    type_value…