[socket-nif|test] Updated test case for connect timeout

The connect timeout test case uses the listen backlog argument
to test connect timeout (its set to 1). The idea is that when
the server backlog is full, it should not reply. The client attempting
to connect will then get a timeout.
But as it turns out, this behaviour is not "set in stone". On FreeBSD
11.2, the result is instead a 'econnreset'.

It should also be noted that this local connections. That is, both end
of the connection is on the same machine.

So, test case has been updated to also accept a econnreset (even
though that is not what it is testing).

OTP-14831

1 files changed, 17 insertions, 1 deletions

diff --git a/lib/kernel/test/socket_SUITE.erl b/lib/kernel/test/socket_SUITE.erl
index d4cd144168..f3a7d84e81 100644
--- a/lib/kernel/test/socket_SUITE.erl
+++ b/lib/kernel/test/socket_SUITE.erl
@@ -203,7 +203,15 @@ api_b_open_and_close(Domain, Type, Proto) ->
                  {error, Reason} ->
                      ?FAIL({open, Reason})
              end,
-    {ok, Domain} = socket:getopt(Socket, socket, domain),
+    %% Domain is not available on all platforms: 
+    case socket:getopt(Socket, socket, domain) of
+	{ok, Domain} ->
+	    ok;
+	{error, einval} ->
+	    ok;
+	Else ->
+	    ?FAIL({getopt, domain, Else})
+    end,
     {ok, Type}   = socket:getopt(Socket, socket, type),
     {ok, Proto}  = socket:getopt(Socket, socket, protocol),
     Self = self(),
@@ -558,6 +566,11 @@ api_to_connect_tcp6(_Config) when is_list(_Config) ->
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% We use the backlog (listen) argument to test this.
+%% Note that the behaviour of the TCP "server side" can vary when 
+%% a client connect to a "busy" server (full backlog).
+%% For instance, on FreeBSD (11.2) the reponse when the backlog is full
+%% is a econreset.
 
 api_to_connect_tcp(Domain) ->
     process_flag(trap_exit, true),
@@ -621,6 +634,9 @@ api_to_connect_tcp_await_timeout([Sock|Socks], ServerSA, ID) ->
         {error, timeout} ->
             p("expected timeout (~w)", [ID]),
             ok;
+        {error, econnreset = Reason} ->
+            p("failed connecting: ~p - giving up", [Reason]),
+            ok;
         {error, Reason} ->
             p("failed connecting: ~p", [Reason]),
             ?FAIL({recv, Reason});