Merge branch 'raimo/uds-support/OTP-13643'

* raimo/uds-support/OTP-13643:
  Update test cases after daily builds
  Return eafnosupport when not supported
  Add AF_LOCAL test cases
  Handle 'undefined' in fdopen

4 files changed, 429 insertions, 46 deletions

diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl
index 9fc685e728..a91a6ed517 100644
--- a/lib/kernel/src/inet.erl
+++ b/lib/kernel/src/inet.erl
@@ -1344,18 +1344,12 @@ open(FdO, Addr, Port, Opts, Protocol, Family, Type, Module)
     case prim_inet:open(Protocol, Family, Type, OpenOpts) of
 	{ok,S} ->
 	    case prim_inet:setopts(S, Opts) of
+		ok when Addr =:= undefined ->
+		    inet_db:register_socket(S, Module),
+		    {ok,S};
 		ok ->
-		    case
-			case Addr of
-			    undefined ->
-				{ok, undefined};
-			    _ when is_list(Addr) ->
-				bindx(S, Addr, Port);
-			    _ ->
-				prim_inet:bind(S, Addr, Port)
-			end
-		    of
-			{ok, _} -> 
+		    case bind(S, Addr, Port) of
+			{ok, _} ->
 			    inet_db:register_socket(S, Module),
 			    {ok,S};
 			Error  ->
@@ -1373,6 +1367,11 @@ open(Fd, Addr, Port, Opts, Protocol, Family, Type, Module)
   when is_integer(Fd) ->
     fdopen(Fd, Addr, Port, Opts, Protocol, Family, Type, Module).
 
+bind(S, Addr, Port) when is_list(Addr) ->
+    bindx(S, Addr, Port);
+bind(S, Addr, Port) ->
+    prim_inet:bind(S, Addr, Port).
+
 bindx(S, [Addr], Port0) ->
     {IP, Port} = set_bindx_port(Addr, Port0),
     prim_inet:bind(S, IP, Port);
@@ -1413,34 +1412,36 @@ fdopen(Fd, Opts, Protocol, Family, Type, Module) ->
     fdopen(Fd, any, 0, Opts, Protocol, Family, Type, Module).
 
 fdopen(Fd, Addr, Port, Opts, Protocol, Family, Type, Module) ->
-    IsAnyAddr = (Addr == {0,0,0,0} orelse Addr == {0,0,0,0,0,0,0,0} 
-                 orelse Addr == any),
-    Bound = Port == 0 andalso IsAnyAddr,
+    Bound =
+	%% We do not do any binding if default port+addr options
+	%% were given, in order to keep backwards compatability
+	%% with pre Erlang/OTP 17
+	case Addr of
+	    {0,0,0,0} when Port =:= 0 -> true;
+	    {0,0,0,0,0,0,0,0} when Port =:= 0 -> true;
+	    any when Port =:= 0 -> true;
+	    _ -> false
+	end,
     case prim_inet:fdopen(Protocol, Family, Type, Fd, Bound) of
 	{ok, S} ->
 	    case prim_inet:setopts(S, Opts) of
+		ok
+		  when Addr =:= undefined;
+		       Bound ->
+		    inet_db:register_socket(S, Module),
+		    {ok, S};
 		ok ->
-                    case if
-                             Bound ->
-                                 %% We do not do any binding if default
-                                 %% port+addr options where given in order
-                                 %% to keep backwards compatability with
-                                 %% pre Erlang/TOP 17
-                                 {ok, ok};
-                             is_list(Addr) ->
-                                 bindx(S, Addr, Port);
-                             true ->
-                                 prim_inet:bind(S, Addr, Port)
-                         end of
-                        {ok, _} ->
-                            inet_db:register_socket(S, Module),
-                            {ok, S};
-                        Error  ->
-                            prim_inet:close(S),
-                            Error
+		    case bind(S, Addr, Port) of
+			{ok, _} ->
+			    inet_db:register_socket(S, Module),
+			    {ok, S};
+			Error  ->
+			    prim_inet:close(S),
+			    Error
                     end;
 		Error ->
-		    prim_inet:close(S), Error
+		    prim_inet:close(S),
+		    Error
 	    end;
 	Error -> Error
     end.
diff --git a/lib/kernel/src/local_tcp.erl b/lib/kernel/src/local_tcp.erl
index e3c67dfbb7..90e0fa2162 100644
--- a/lib/kernel/src/local_tcp.erl
+++ b/lib/kernel/src/local_tcp.erl
@@ -175,4 +175,4 @@ accept(L, Timeout) ->
 %% Create a port/socket from a file descriptor
 %%
 fdopen(Fd, Opts) ->
-    inet:fdopen(Fd, Opts, ?PROTO, ?FAMILY, ?TYPE, ?MODULE).
+    inet:open(Fd, undefined, 0, Opts, ?PROTO, ?FAMILY, ?TYPE, ?MODULE).
diff --git a/lib/kernel/test/gen_tcp_api_SUITE.erl b/lib/kernel/test/gen_tcp_api_SUITE.erl
index 54298e6309..026cbf8b28 100644
--- a/lib/kernel/test/gen_tcp_api_SUITE.erl
+++ b/lib/kernel/test/gen_tcp_api_SUITE.erl
@@ -34,7 +34,11 @@
 	 t_recv_timeout/1, t_recv_eof/1, t_recv_delim/1,
 	 t_shutdown_write/1, t_shutdown_both/1, t_shutdown_error/1,
 	 t_shutdown_async/1,
-	 t_fdopen/1, t_fdconnect/1, t_implicit_inet6/1]).
+	 t_fdopen/1, t_fdconnect/1, t_implicit_inet6/1,
+	 t_local_basic/1, t_local_unbound/1, t_local_fdopen/1,
+	 t_local_fdopen_listen/1, t_local_fdopen_listen_unbound/1,
+	 t_local_fdopen_connect/1, t_local_fdopen_connect_unbound/1,
+	 t_local_abstract/1]).
 
 -export([getsockfd/0,closesockfd/1]).
 
@@ -45,12 +49,18 @@ suite() ->
 all() -> 
     [{group, t_accept}, {group, t_connect}, {group, t_recv},
      t_shutdown_write, t_shutdown_both, t_shutdown_error,
-     t_shutdown_async, t_fdopen, t_fdconnect, t_implicit_inet6].
+     t_shutdown_async, t_fdopen, t_fdconnect, t_implicit_inet6,
+     {group, t_local}].
 
 groups() -> 
     [{t_accept, [], [t_accept_timeout]},
      {t_connect, [], [t_connect_timeout, t_connect_bad]},
-     {t_recv, [], [t_recv_timeout, t_recv_eof, t_recv_delim]}].
+     {t_recv, [], [t_recv_timeout, t_recv_eof, t_recv_delim]},
+     {t_local, [],
+      [t_local_basic, t_local_unbound, t_local_fdopen,
+       t_local_fdopen_listen, t_local_fdopen_listen_unbound,
+       t_local_fdopen_connect, t_local_fdopen_connect_unbound,
+       t_local_abstract]}].
 
 
 
@@ -60,17 +70,36 @@ init_per_suite(Config) ->
 end_per_suite(_Config) ->
     ok.
 
+init_per_group(t_local, Config) ->
+    case gen_tcp:connect({local,<<"/">>}, 0, []) of
+	{error,eafnosupport} ->
+	    {skip, "AF_LOCAL not supported"};
+	{error,_} ->
+	    Config
+    end;
 init_per_group(_GroupName, Config) ->
     Config.
 
-end_per_group(_,_Config) ->
+end_per_group(t_local, _Config) ->
+    delete_local_filenames();
+end_per_group(_, _Config) ->
     ok.
 
+
+init_per_testcase(Func, Config)
+  when Func =:= undefined -> % Insert your testcase name here
+    dbg:tracer(),
+    dbg:p(self(), c),
+    dbg:tpl(prim_inet, cx),
+    dbg:tpl(local_tcp, cx),
+    dbg:tpl(inet, cx),
+    dbg:tpl(gen_tcp, cx),
+    Config;
 init_per_testcase(_Func, Config) ->
     Config.
 
 end_per_testcase(_Func, _Config) ->
-    ok.
+    dbg:stop().
 
 %%% gen_tcp:accept/1,2
 
@@ -308,6 +337,192 @@ implicit_inet6(S, Addr) ->
     ok = gen_tcp:close(S1).
 
 
+
+t_local_basic(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    CFile = local_filename(client),
+    CAddr = {local,bin_filename(CFile)},
+    _ = file:delete(SFile),
+    _ = file:delete(CFile),
+    %%
+    L =
+	ok(
+	  gen_tcp:listen(0, [{ifaddr,{local,SFile}},{active,false}])),
+    C =
+	ok(
+	  gen_tcp:connect(
+	    {local,SFile}, 0, [{ifaddr,{local,CFile}},{active,false}])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, CAddr),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    %%
+    ok = file:delete(SFile),
+    ok = file:delete(CFile),
+    ok.
+
+t_local_unbound(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    %%
+    L = ok(gen_tcp:listen(0, [{ifaddr,SAddr},{active,false}])),
+    C = ok(gen_tcp:connect(SAddr, 0, [{active,false}])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, {local,<<>>}),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    ok = file:delete(SFile),
+    ok.
+
+t_local_fdopen(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    %%
+    L = ok(gen_tcp:listen(0, [{ifaddr,SAddr},{active,false}])),
+    C0 = ok(gen_tcp:connect(SAddr, 0, [{active,false}])),
+    Fd = ok(prim_inet:getfd(C0)),
+    ok = prim_inet:ignorefd(C0, true),
+    C = ok(gen_tcp:fdopen(Fd, [local])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, {local,<<>>}),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    ok = gen_tcp:close(C0),
+    ok = file:delete(SFile),
+    ok.
+
+t_local_fdopen_listen(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    L0 = ok(gen_tcp:listen(0, [{ifaddr,SAddr},{active,false}])),
+    Fd = ok(prim_inet:getfd(L0)),
+    L = ok(gen_tcp:listen(0, [{fd,Fd},local,{active,false}])),
+    C = ok(gen_tcp:connect(SAddr, 0, [{active,false}])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, {local,<<>>}),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(L0),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    ok = file:delete(SFile),
+    ok.
+
+t_local_fdopen_listen_unbound(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    P = ok(prim_inet:open(tcp, local, stream)),
+    Fd = ok(prim_inet:getfd(P)),
+    L =
+	ok(gen_tcp:listen(
+	     0, [{fd,Fd},{ifaddr,SAddr},{active,false}])),
+    C = ok(gen_tcp:connect(SAddr, 0, [{active,false}])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, {local,<<>>}),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(P),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    ok = file:delete(SFile),
+    ok.
+
+t_local_fdopen_connect(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    CFile = local_filename(client),
+    CAddr = {local,bin_filename(CFile)},
+    _ = file:delete(SFile),
+    _ = file:delete(CFile),
+    L = ok(gen_tcp:listen(0, [{ifaddr,SAddr},{active,false}])),
+    P = ok(prim_inet:open(tcp, local, stream)),
+    Fd = ok(prim_inet:getfd(P)),
+    C =
+	ok(gen_tcp:connect(
+	     SAddr, 0, [{fd,Fd},{ifaddr,CAddr},{active,false}])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, CAddr),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    ok = gen_tcp:close(P),
+    ok = file:delete(SFile),
+    ok.
+
+t_local_fdopen_connect_unbound(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    L = ok(gen_tcp:listen(0, [{ifaddr,SAddr},{active,false}])),
+    P = ok(prim_inet:open(tcp, local, stream)),
+    Fd = ok(prim_inet:getfd(P)),
+    C =	ok(gen_tcp:connect(SAddr, 0, [{fd,Fd},{active,false}])),
+    S = ok(gen_tcp:accept(L)),
+    SAddr = ok(inet:sockname(L)),
+    {error,enotconn} = inet:peername(L),
+    local_handshake(S, SAddr, C, {local,<<>>}),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:close(S),
+    ok = gen_tcp:close(C),
+    ok = gen_tcp:close(P),
+    ok = file:delete(SFile),
+    ok.
+
+t_local_abstract(_Config) ->
+    case os:type() of
+	{unix,linux} ->
+	    AbstAddr = {local,<<>>},
+	    L =
+		ok(gen_tcp:listen(
+		     0, [{ifaddr,AbstAddr},{active,false}])),
+	    {local,_} = SAddr = ok(inet:sockname(L)),
+	    C =
+		ok(gen_tcp:connect(
+		     SAddr, 0, [{ifaddr,AbstAddr},{active,false}])),
+	    {local,_} = CAddr = ok(inet:sockname(C)),
+	    S = ok(gen_tcp:accept(L)),
+	    {error,enotconn} = inet:peername(L),
+	    local_handshake(S, SAddr, C, CAddr),
+	    ok = gen_tcp:close(L),
+	    ok = gen_tcp:close(S),
+	    ok = gen_tcp:close(C),
+	    ok;
+	_ ->
+	    {skip,"AF_LOCAL Abstract Addresses only supported on Linux"}
+    end.
+
+
+local_handshake(S, SAddr, C, CAddr) ->
+    SData = "9876543210",
+    CData = "0123456789",
+    SAddr = ok(inet:sockname(S)),
+    CAddr = ok(inet:sockname(C)),
+    CAddr = ok(inet:peername(S)),
+    SAddr = ok(inet:peername(C)),
+    ok = gen_tcp:send(C, CData),
+    ok = gen_tcp:send(S, SData),
+    CData = ok(gen_tcp:recv(S, length(CData))),
+    SData = ok(gen_tcp:recv(C, length(SData))),
+    ok.
+
 %%% Utilities
 
 %% Calls M:F/length(A), which should return a timeout error, and complete
@@ -369,8 +584,28 @@ unused_ip(A, B, C, D) ->
 	{error, _} -> {ok, {A, B, C, D}}
     end.
 
-ok({ok,V}) -> V.
-
+ok({ok,V}) -> V;
+ok(NotOk) ->
+    try throw(not_ok)
+    catch
+	Thrown ->
+	    erlang:raise(
+	      error, {Thrown, NotOk}, tl(erlang:get_stacktrace()))
+    end.
 
 getsockfd() -> undefined.
 closesockfd(_FD) -> undefined.
+
+local_filename(Tag) ->
+    "/tmp/" ?MODULE_STRING "_" ++ os:getpid() ++ "_" ++ atom_to_list(Tag).
+
+bin_filename(String) ->
+    unicode:characters_to_binary(String, file:native_name_encoding()).
+
+delete_local_filenames() ->
+    _ =
+	[file:delete(F) ||
+	    F <-
+		filelib:wildcard(
+		  "/tmp/" ?MODULE_STRING "_" ++ os:getpid() ++ "_*")],
+    ok.
diff --git a/lib/kernel/test/gen_udp_SUITE.erl b/lib/kernel/test/gen_udp_SUITE.erl
index 44539bf44c..db4e174374 100644
--- a/lib/kernel/test/gen_udp_SUITE.erl
+++ b/lib/kernel/test/gen_udp_SUITE.erl
@@ -35,7 +35,9 @@
 
 -export([send_to_closed/1, active_n/1,
 	 buffer_size/1, binary_passive_recv/1, bad_address/1,
-	 read_packets/1, open_fd/1, connect/1, implicit_inet6/1]).
+	 read_packets/1, open_fd/1, connect/1, implicit_inet6/1,
+	 local_basic/1, local_unbound/1,
+	 local_fdopen/1, local_fdopen_unbound/1, local_abstract/1]).
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
@@ -44,10 +46,13 @@ suite() ->
 all() -> 
     [send_to_closed, buffer_size, binary_passive_recv,
      bad_address, read_packets, open_fd, connect,
-     implicit_inet6, active_n].
+     implicit_inet6, active_n,
+     {group, local}].
 
 groups() -> 
-    [].
+    [{local, [],
+      [local_basic, local_unbound,
+       local_fdopen, local_fdopen_unbound, local_abstract]}].
 
 init_per_suite(Config) ->
     Config.
@@ -55,9 +60,19 @@ init_per_suite(Config) ->
 end_per_suite(_Config) ->
     ok.
 
+init_per_group(local, Config) ->
+    case gen_udp:open(0, [local]) of
+	{ok,S} ->
+	    ok = gen_udp:close(S),
+	    Config;
+	{error,eafnosupport} ->
+	    {skip, "AF_LOCAL not supported"}
+    end;
 init_per_group(_GroupName, Config) ->
     Config.
 
+end_per_group(local, _Config) ->
+    delete_local_filenames();
 end_per_group(_GroupName, Config) ->
     Config.
 
@@ -65,7 +80,7 @@ end_per_group(_GroupName, Config) ->
 init_per_testcase(_Case, Config) ->
     Config.
 
-end_per_testcase(_Case, Config) ->
+end_per_testcase(_Case, _Config) ->
     ok.
 
 %%-------------------------------------------------------------
@@ -550,6 +565,116 @@ active_n(Config) when is_list(Config) ->
     ok = gen_udp:close(S1),
     ok.
 
+
+local_basic(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    CFile = local_filename(client),
+    CAddr = {local,bin_filename(CFile)},
+    _ = file:delete(SFile),
+    _ = file:delete(CFile),
+    %%
+    S = ok(gen_udp:open(0, [{ifaddr,{local,SFile}},{active,false}])),
+    C = ok(gen_udp:open(0, [{ifaddr,{local,CFile}},{active,false}])),
+    SAddr = ok(inet:sockname(S)),
+    CAddr = ok(inet:sockname(C)),
+    local_handshake(S, SAddr, C, CAddr),
+    ok = gen_udp:close(S),
+    ok = gen_udp:close(C),
+    %%
+    ok = file:delete(SFile),
+    ok = file:delete(CFile),
+    ok.
+
+local_unbound(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    %%
+    S = ok(gen_udp:open(0, [{ifaddr,SAddr},{active,false}])),
+    C = ok(gen_udp:open(0, [local,{active,false}])),
+    SAddr = ok(inet:sockname(S)),
+    local_handshake(S, SAddr, C, undefined),
+    ok = gen_udp:close(S),
+    ok = gen_udp:close(C),
+    %%
+    ok = file:delete(SFile),
+    ok.
+
+local_fdopen(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    CFile = local_filename(client),
+    CAddr = {local,bin_filename(CFile)},
+    _ = file:delete(SFile),
+    _ = file:delete(CFile),
+    %%
+    S0 = ok(gen_udp:open(0, [{ifaddr,SAddr},{active,false}])),
+    C = ok(gen_udp:open(0, [{ifaddr,{local,CFile}},{active,false}])),
+    SAddr = ok(inet:sockname(S0)),
+    CAddr = ok(inet:sockname(C)),
+    Fd = ok(prim_inet:getfd(S0)),
+    S = ok(gen_udp:open(0, [{fd,Fd},local,{active,false}])),
+    SAddr = ok(inet:sockname(S)),
+    local_handshake(S, SAddr, C, CAddr),
+    ok = gen_udp:close(S),
+    ok = gen_udp:close(S0),
+    ok = gen_udp:close(C),
+    %%
+    ok = file:delete(SFile),
+    ok = file:delete(CFile),
+    ok.
+
+local_fdopen_unbound(_Config) ->
+    SFile = local_filename(server),
+    SAddr = {local,bin_filename(SFile)},
+    _ = file:delete(SFile),
+    %%
+    S = ok(gen_udp:open(0, [{ifaddr,SAddr},{active,false}])),
+    C0 = ok(gen_udp:open(0, [local,{active,false}])),
+    SAddr = ok(inet:sockname(S)),
+    Fd = ok(prim_inet:getfd(C0)),
+    C = ok(gen_udp:open(0, [{fd,Fd},local,{active,false}])),
+    local_handshake(S, SAddr, C, undefined),
+    ok = gen_udp:close(S),
+    ok = gen_udp:close(C),
+    ok = gen_udp:close(C0),
+    %%
+    ok = file:delete(SFile),
+    ok.
+
+local_abstract(_Config) ->
+    case os:type() of
+	{unix,linux} ->
+	    S = ok(gen_udp:open(0, [{ifaddr,{local,<<>>}},{active,false}])),
+	    C = ok(gen_udp:open(0, [{ifaddr,{local,<<>>}},{active,false}])),
+	    {local,_} = SAddr = ok(inet:sockname(S)),
+	    {local,_} = CAddr = ok(inet:sockname(C)),
+	    local_handshake(S, SAddr, C, CAddr),
+	    ok = gen_udp:close(S),
+	    ok = gen_udp:close(C),
+	    ok;
+	_ ->
+	    {skip,"AF_LOCAL Abstract Addresses only supported on Linux"}
+    end.
+
+
+local_handshake(S, SAddr, C, CAddr) ->
+    SData = "9876543210",
+    CData = "0123456789",
+    ok = gen_udp:send(C, SAddr, 0, CData),
+    case ok(gen_tcp:recv(S, 112)) of
+	{{unspec,<<>>}, 0, CData} when CAddr =:= undefined ->
+	    ok;
+	{{local,<<>>}, 0, CData} when CAddr =:= undefined ->
+	    ok;
+	{CAddr, 0, CData} when CAddr =/= undefined ->
+	    ok = gen_udp:send(S, CAddr, 0, SData),
+	    {SAddr, 0, SData} = ok(gen_tcp:recv(C, 112)),
+	    ok
+
+    end.
+
 %%
 %% Utils
 %%
@@ -630,4 +755,26 @@ implicit_inet6(S1, Active, Addr) ->
     {Addr,P2,"pong"} = ok(gen_udp:recv(S1, 1024)),
     ok = gen_udp:close(S2).
 
-ok({ok,V}) -> V.
+ok({ok,V}) -> V;
+ok(NotOk) ->
+    try throw(not_ok)
+    catch
+	Thrown ->
+	    erlang:raise(
+	      error, {Thrown, NotOk}, tl(erlang:get_stacktrace()))
+    end.
+
+
+local_filename(Tag) ->
+    "/tmp/" ?MODULE_STRING "_" ++ os:getpid() ++ "_" ++ atom_to_list(Tag).
+
+bin_filename(String) ->
+    unicode:characters_to_binary(String, file:native_name_encoding()).
+
+delete_local_filenames() ->
+    _ =
+	[file:delete(F) ||
+	    F <-
+		filelib:wildcard(
+		  "/tmp/" ?MODULE_STRING "_" ++ os:getpid() ++ "_*")],
+    ok.