Merge branch 'nybek/fix_so_linger_zero__simple'

* nybek/fix_so_linger_zero__simple:
  Update prim_inet.beam
  Fix socket option {linger, {true, 0}} to abort TCP connections
  Apply 'show_econnreset' socket option to send errors as well
  Add 'show_econnreset' TCP socket option

5 files changed, 352 insertions, 3 deletions

diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml
index 77a8caaaf6..4dd9e0e221 100644
--- a/lib/kernel/doc/src/inet.xml
+++ b/lib/kernel/doc/src/inet.xml
@@ -1037,6 +1037,36 @@ setcap cap_sys_admin,cap_sys_ptrace,cap_dac_read_search+epi beam.smp
 			<marker id="option-sndbuf"></marker>
           </item>
 
+          <tag><c>{show_econnreset, Boolean}</c>(TCP/IP sockets)</tag>
+          <item>
+            <p>When this option is set to <c>false</c>, as it is by
+              default, an RST that is received from the TCP peer is treated
+              as a normal close (as though a FIN was sent). A caller
+              to <seealso marker="gen_tcp#recv/2">gen_tcp:recv/2</seealso>
+              will get <c>{error, closed}</c>. In active
+              mode the controlling process will receive a
+              <c>{tcp_close, Socket}</c> message, indicating that the
+              peer has closed the connection.</p>
+            <p>Setting this option to <c>true</c> will allow you to
+              distinguish between a connection that was closed normally,
+              and one which was aborted (intentionally or unintentionally)
+              by the TCP peer. A call to
+              <seealso marker="gen_tcp#recv/2">gen_tcp:recv/2</seealso>
+              will return <c>{error, econnreset}</c>. In
+              active mode, the controlling process will receive a
+              <c>{tcp_error, Socket, econnreset}</c> message
+              before the usual <c>{tcp_closed, Socket}</c>, as is
+              the case for any other socket error. Calls to
+              <seealso marker="gen_tcp#send/2">gen_tcp:send/2</seealso>
+              will also return <c>{error, econnreset}</c> when it
+              is detected that a TCP peer has sent an RST.</p>
+            <p>A connected socket returned from
+              <seealso marker="gen_tcp#accept/1">gen_tcp:accept/1</seealso>
+              will inherit the <c>show_econnreset</c> setting from the
+              listening socket.</p>
+			<marker id="option-show_econnreset"></marker>
+          </item>
+
           <tag><c>{sndbuf, Size}</c></tag>
           <item>
             <p>The minimum size of the send buffer to use for the socket.
diff --git a/lib/kernel/src/gen_tcp.erl b/lib/kernel/src/gen_tcp.erl
index bc8ffbe5e3..86251fc8f1 100644
--- a/lib/kernel/src/gen_tcp.erl
+++ b/lib/kernel/src/gen_tcp.erl
@@ -58,6 +58,7 @@
         {reuseaddr,       boolean()} |
         {send_timeout,    non_neg_integer() | infinity} |
         {send_timeout_close, boolean()} |
+        {show_econnreset, boolean()} |
         {sndbuf,          non_neg_integer()} |
         {tos,             non_neg_integer()} |
 	{ipv6_v6only,     boolean()}.
@@ -89,6 +90,7 @@
         reuseaddr |
         send_timeout |
         send_timeout_close |
+        show_econnreset |
         sndbuf |
         tos |
 	ipv6_v6only.
diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl
index d668738109..1ae90aaf0c 100644
--- a/lib/kernel/src/inet.erl
+++ b/lib/kernel/src/inet.erl
@@ -654,7 +654,7 @@ options() ->
      multicast_if, multicast_ttl, multicast_loop,
      exit_on_close, high_watermark, low_watermark,
      high_msgq_watermark, low_msgq_watermark,
-     send_timeout, send_timeout_close
+     send_timeout, send_timeout_close, show_econnreset
     ].
 
 %% Return a list of statistics options
@@ -672,7 +672,8 @@ connect_options() ->
     [tos, priority, reuseaddr, keepalive, linger, sndbuf, recbuf, nodelay,
      header, active, packet, packet_size, buffer, mode, deliver,
      exit_on_close, high_watermark, low_watermark, high_msgq_watermark,
-     low_msgq_watermark, send_timeout, send_timeout_close, delay_send, raw].
+     low_msgq_watermark, send_timeout, send_timeout_close, delay_send, raw,
+     show_econnreset].
     
 connect_options(Opts, Family) ->
     BaseOpts = 
@@ -740,7 +741,7 @@ listen_options() ->
      header, active, packet, buffer, mode, deliver, backlog, ipv6_v6only,
      exit_on_close, high_watermark, low_watermark, high_msgq_watermark,
      low_msgq_watermark, send_timeout, send_timeout_close, delay_send,
-     packet_size, raw].
+     packet_size, raw, show_econnreset].
 
 listen_options(Opts, Family) ->
     BaseOpts = 
diff --git a/lib/kernel/src/inet_int.hrl b/lib/kernel/src/inet_int.hrl
index 889b596a22..7bd973af99 100644
--- a/lib/kernel/src/inet_int.hrl
+++ b/lib/kernel/src/inet_int.hrl
@@ -147,6 +147,7 @@
 -define(INET_LOPT_MSGQ_HIWTRMRK,  36).
 -define(INET_LOPT_MSGQ_LOWTRMRK,  37).
 -define(INET_LOPT_NETNS,          38).
+-define(INET_LOPT_TCP_SHOW_ECONNRESET, 39).
 % Specific SCTP options: separate range:
 -define(SCTP_OPT_RTOINFO,	 	100).
 -define(SCTP_OPT_ASSOCINFO,	 	101).
diff --git a/lib/kernel/test/gen_tcp_misc_SUITE.erl b/lib/kernel/test/gen_tcp_misc_SUITE.erl
index 76a9708a58..44e7984401 100644
--- a/lib/kernel/test/gen_tcp_misc_SUITE.erl
+++ b/lib/kernel/test/gen_tcp_misc_SUITE.erl
@@ -31,6 +31,11 @@
 	 init_per_testcase/2, end_per_testcase/2,
 	 otp_3924/1, otp_3924_sender/4, closed_socket/1,
 	 shutdown_active/1, shutdown_passive/1, shutdown_pending/1,
+	 show_econnreset_active/1, show_econnreset_active_once/1,
+	 show_econnreset_passive/1, econnreset_after_sync_send/1,
+	 econnreset_after_async_send_active/1,
+	 econnreset_after_async_send_active_once/1,
+	 econnreset_after_async_send_passive/1, linger_zero/1,
 	 default_options/1, http_bad_packet/1, 
 	 busy_send/1, busy_disconnect_passive/1, busy_disconnect_active/1,
 	 fill_sendq/1, partial_recv_and_close/1, 
@@ -94,6 +99,11 @@ all() ->
      iter_max_socks, passive_sockets, active_n,
      accept_closed_by_other_process, otp_3924, closed_socket,
      shutdown_active, shutdown_passive, shutdown_pending,
+     show_econnreset_active, show_econnreset_active_once,
+     show_econnreset_passive, econnreset_after_sync_send,
+     econnreset_after_async_send_active,
+     econnreset_after_async_send_active_once,
+     econnreset_after_async_send_passive, linger_zero,
      default_options, http_bad_packet, busy_send,
      busy_disconnect_passive, busy_disconnect_active,
      fill_sendq, partial_recv_and_close,
@@ -1079,6 +1089,311 @@ shutdown_pending(Config) when is_list(Config) ->
 	     gen_tcp:close(S)
      end.
 
+%%
+%% Test 'show_econnreset' option
+%%
+
+show_econnreset_active(Config) when is_list(Config) ->
+    %% First confirm everything works with option turned off.
+    {ok, L} = gen_tcp:listen(0, []),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port, [{active, false}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    ok = inet:setopts(Client, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(Client),
+    receive
+       {tcp_closed, S} ->
+	   ok;
+       Other ->
+	   ?t:fail({unexpected1, Other})
+    after 1000 ->
+	?t:fail({timeout, {server, no_tcp_closed}})
+    end,
+
+    %% Now test with option switched on.
+    %% Note: We are also testing that the show_econnreset option is
+    %% inherited from the listening socket by the accepting socket.
+    {ok, L1} = gen_tcp:listen(0, [{show_econnreset, true}]),
+    {ok, Port1} = inet:port(L1),
+    {ok, Client1} = gen_tcp:connect(localhost, Port1, [{active, false}]),
+    {ok, S1} = gen_tcp:accept(L1),
+    ok = gen_tcp:close(L1),
+    ok = inet:setopts(Client1, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(Client1),
+    receive
+	{tcp_error, S1, econnreset} ->
+	    receive
+		{tcp_closed, S1} ->
+		    ok;
+		Other1 ->
+		    ?t:fail({unexpected2, Other1})
+	    after 1 ->
+		?t:fail({timeout, {server, no_tcp_closed}})
+	    end;
+	Other2 ->
+	    ?t:fail({unexpected3, Other2})
+    after 1000 ->
+	?t:fail({timeout, {server, no_tcp_error}})
+    end.
+
+show_econnreset_active_once(Config) when is_list(Config) ->
+    %% Now test using {active, once}
+    {ok, L} = gen_tcp:listen(0,
+			   [{active, false},
+			    {show_econnreset, true}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port, [{active, false}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    ok = inet:setopts(Client, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(Client),
+    ok = ?t:sleep(20),
+    ok = receive Msg -> {unexpected_msg, Msg} after 0 -> ok end,
+    ok = inet:setopts(S, [{active, once}]),
+    receive
+	{tcp_error, S, econnreset} ->
+	    receive
+		{tcp_closed, S} ->
+		    ok;
+		Other1 ->
+		    ?t:fail({unexpected1, Other1})
+	    after 1 ->
+		?t:fail({timeout, {server, no_tcp_closed}})
+	    end;
+	Other2 ->
+	    ?t:fail({unexpected2, Other2})
+    after 1000 ->
+	?t:fail({timeout, {server, no_tcp_error}})
+    end.
+
+show_econnreset_passive(Config) when is_list(Config) ->
+    %% First confirm everything works with option turned off.
+    {ok, L} = gen_tcp:listen(0, [{active, false}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port, [{active, false}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    ok = inet:setopts(S, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S),
+    ok = ?t:sleep(1),
+    {error, closed} = gen_tcp:recv(Client, 0),
+
+    %% Now test with option switched on.
+    {ok, L1} = gen_tcp:listen(0, [{active, false}]),
+    {ok, Port1} = inet:port(L1),
+    {ok, Client1} = gen_tcp:connect(localhost, Port1,
+				 [{active, false},
+				  {show_econnreset, true}]),
+    {ok, S1} = gen_tcp:accept(L1),
+    ok = gen_tcp:close(L1),
+    ok = inet:setopts(S1, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S1),
+    ok = ?t:sleep(1),
+    {error, econnreset} = gen_tcp:recv(Client1, 0).
+
+econnreset_after_sync_send(Config) when is_list(Config) ->
+    %% First confirm everything works with option turned off.
+    {ok, L} = gen_tcp:listen(0, [{active, false}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port, [{active, false}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    ok = inet:setopts(S, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S),
+    ok = ?t:sleep(20),
+    {error, closed} = gen_tcp:send(Client, "Whatever"),
+
+    %% Now test with option switched on.
+    {ok, L1} = gen_tcp:listen(0, [{active, false}]),
+    {ok, Port1} = inet:port(L1),
+    {ok, Client1} = gen_tcp:connect(localhost, Port1,
+          			  [{active, false},
+          			   {show_econnreset, true}]),
+    {ok, S1} = gen_tcp:accept(L1),
+    ok = gen_tcp:close(L1),
+    ok = inet:setopts(S1, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S1),
+    ok = ?t:sleep(20),
+    {error, econnreset} = gen_tcp:send(Client1, "Whatever").
+
+econnreset_after_async_send_active(Config) when is_list(Config) ->
+    {OS, _} = os:type(),
+    Payload = lists:duplicate(1024 * 1024, $.),
+
+    %% First confirm everything works with option turned off.
+    {ok, L} = gen_tcp:listen(0, [{active, false}, {recbuf, 4096}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port, [{sndbuf, 4096}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    ok = gen_tcp:send(Client, Payload),
+    case erlang:port_info(Client, queue_size) of
+	{queue_size, N} when N > 0 -> ok;
+	{queue_size, 0} when OS =:= win32 -> ok;
+	{queue_size, 0} = T -> ?t:fail(T)
+    end,
+    ok = gen_tcp:send(S, "Whatever"),
+    ok = ?t:sleep(20),
+    ok = inet:setopts(S, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S),
+    ok = ?t:sleep(20),
+    receive
+	{tcp, Client, "Whatever"} ->
+	    receive
+		{tcp_closed, Client} ->
+		    ok;
+		Other1 ->
+		    ?t:fail({unexpected1, Other1})
+	    end;
+	Other2 ->
+	    ?t:fail({unexpected2, Other2})
+    end,
+
+    %% Now test with option switched on.
+    {ok, L1} = gen_tcp:listen(0, [{active, false}, {recbuf, 4096}]),
+    {ok, Port1} = inet:port(L1),
+    {ok, Client1} = gen_tcp:connect(localhost, Port1,
+				  [{sndbuf, 4096},
+				   {show_econnreset, true}]),
+    {ok, S1} = gen_tcp:accept(L1),
+    ok = gen_tcp:close(L1),
+    ok = gen_tcp:send(Client1, Payload),
+    case erlang:port_info(Client1, queue_size) of
+	{queue_size, N1} when N1 > 0 -> ok;
+	{queue_size, 0} when OS =:= win32 -> ok;
+	{queue_size, 0} = T1 -> ?t:fail(T1)
+    end,
+    ok = gen_tcp:send(S1, "Whatever"),
+    ok = ?t:sleep(20),
+    ok = inet:setopts(S1, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S1),
+    ok = ?t:sleep(20),
+    receive
+	{tcp, Client1, "Whatever"} ->
+	    receive
+		{tcp_error, Client1, econnreset} ->
+		    receive
+			{tcp_closed, Client1} ->
+			    ok;
+			Other3 ->
+			    ?t:fail({unexpected3, Other3})
+		    end;
+		Other4 ->
+		    ?t:fail({unexpected4, Other4})
+	    end;
+	Other5 ->
+	    ?t:fail({unexpected5, Other5})
+    end.
+
+econnreset_after_async_send_active_once(Config) when is_list(Config) ->
+    {OS, _} = os:type(),
+    {ok, L} = gen_tcp:listen(0, [{active, false}, {recbuf, 4096}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port,
+				   [{active, false},
+				    {sndbuf, 4096},
+				    {show_econnreset, true}]),
+    {ok,S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    Payload = lists:duplicate(1024 * 1024, $.),
+    ok = gen_tcp:send(Client, Payload),
+    case erlang:port_info(Client, queue_size) of
+	{queue_size, N} when N > 0 -> ok;
+	{queue_size, 0} when OS =:= win32 -> ok;
+	{queue_size, 0} = T -> ?t:fail(T)
+    end,
+    ok = gen_tcp:send(S, "Whatever"),
+    ok = ?t:sleep(20),
+    ok = inet:setopts(S, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(S),
+    ok = ?t:sleep(20),
+    ok = receive Msg -> {unexpected_msg, Msg} after 0 -> ok end,
+    ok = inet:setopts(Client, [{active, once}]),
+    receive
+	{tcp_error, Client, econnreset} ->
+	    receive
+		{tcp_closed, Client} ->
+		    ok;
+		Other ->
+		    ?t:fail({unexpected1, Other})
+	    end;
+	Other ->
+	    ?t:fail({unexpected2, Other})
+    end.
+
+econnreset_after_async_send_passive(Config) when is_list(Config) ->
+    {OS, _} = os:type(),
+    Payload = lists:duplicate(1024 * 1024, $.),
+
+    %% First confirm everything works with option turned off.
+    {ok, L} = gen_tcp:listen(0, [{active, false}, {recbuf, 4096}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port,
+					 [{active, false},
+					  {sndbuf, 4096}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    ok = inet:setopts(S, [{linger, {true, 0}}]),
+    ok = gen_tcp:send(S, "Whatever"),
+    ok = gen_tcp:send(Client, Payload),
+    case erlang:port_info(Client, queue_size) of
+	{queue_size, N} when N > 0 -> ok;
+	{queue_size, 0} when OS =:= win32 -> ok;
+	{queue_size, 0} = T -> ?t:fail(T)
+    end,
+    ok = gen_tcp:close(S),
+    ok = ?t:sleep(20),
+    {error, closed} = gen_tcp:recv(Client, 0),
+
+    %% Now test with option switched on.
+    {ok, L1} = gen_tcp:listen(0, [{active, false}, {recbuf, 4096}]),
+    {ok, Port1} = inet:port(L1),
+    {ok, Client1} = gen_tcp:connect(localhost, Port1,
+				   [{active, false},
+				    {sndbuf, 4096},
+				    {show_econnreset, true}]),
+    {ok, S1} = gen_tcp:accept(L1),
+    ok = gen_tcp:close(L1),
+    ok = inet:setopts(S1, [{linger, {true, 0}}]),
+    ok = gen_tcp:send(S1, "Whatever"),
+    ok = gen_tcp:send(Client1, Payload),
+    ok = gen_tcp:close(S1),
+    ok = ?t:sleep(20),
+    {error, econnreset} = gen_tcp:recv(Client1, 0).
+
+%%
+%% Test {linger {true, 0}} aborts a connection
+%%
+
+linger_zero(Config) when is_list(Config) ->
+    %% All the econnreset tests will prove that {linger, {true, 0}} aborts
+    %% a connection when the driver queue is empty. We will test here
+    %% that it also works when the driver queue is not empty.
+    {OS, _} = os:type(),
+    {ok, L} = gen_tcp:listen(0, [{active, false},
+				 {recbuf, 4096},
+				 {show_econnreset, true}]),
+    {ok, Port} = inet:port(L),
+    {ok, Client} = gen_tcp:connect(localhost, Port,
+				   [{active, false},
+				    {sndbuf, 4096}]),
+    {ok, S} = gen_tcp:accept(L),
+    ok = gen_tcp:close(L),
+    PayloadSize = 1024 * 1024,
+    Payload = lists:duplicate(PayloadSize, $.),
+    ok = gen_tcp:send(Client, Payload),
+    case erlang:port_info(Client, queue_size) of
+	{queue_size, N} when N > 0 -> ok;
+	{queue_size, 0} when OS =:= win32 -> ok;
+	{queue_size, 0} = T -> ?t:fail(T)
+    end,
+    ok = inet:setopts(Client, [{linger, {true, 0}}]),
+    ok = gen_tcp:close(Client),
+    ok = ?t:sleep(1),
+    undefined = erlang:port_info(Client, connected),
+    {error, econnreset} = gen_tcp:recv(S, PayloadSize).
+
 
 %% Thanks to Luke Gorrie. Tests for a very specific problem with 
 %% corrupt data. The testcase will be killed by the timetrap timeout