[esock] Update the supports functions to also display local

The socket:supports/0,1 now also displays local (Unix Domain Socket).

OTP-15822

3 files changed, 38 insertions, 8 deletions

diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
index a62914d730..c1c72e525f 100644
--- a/erts/emulator/nifs/common/socket_nif.c
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -659,6 +659,7 @@ typedef union {
 #define SOCKET_SUPPORTS_OPTIONS 0x0001
 #define SOCKET_SUPPORTS_SCTP    0x0002
 #define SOCKET_SUPPORTS_IPV6    0x0003
+#define SOCKET_SUPPORTS_LOCAL   0x0004
 
 #define ESOCK_WHICH_PROTO_ERROR -1
 #define ESOCK_WHICH_PROTO_UNSUP -2
@@ -998,6 +999,7 @@ static ERL_NIF_TERM nsupports_options_udp(ErlNifEnv* env);
 static ERL_NIF_TERM nsupports_options_sctp(ErlNifEnv* env);
 static ERL_NIF_TERM nsupports_sctp(ErlNifEnv* env);
 static ERL_NIF_TERM nsupports_ipv6(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_local(ErlNifEnv* env);
 
 static ERL_NIF_TERM nopen(ErlNifEnv* env,
                           int        domain,
@@ -3053,6 +3055,9 @@ ERL_NIF_TERM nif_info(ErlNifEnv*         env,
  *                  {tcp,    [{Opt, boolean()}]},
  *                  {udp,    [{Opt, boolean()}]},
  *                  {sctp,   [{Opt, boolean()}]}]
+ * sctp            boolean()
+ * ipv6            boolean()
+ * local           boolean()
  */
 
 static
@@ -3080,13 +3085,10 @@ ERL_NIF_TERM nif_supports(ErlNifEnv*         env,
 
 
 
-/* nopen - create an endpoint for communication
- *
- * Assumes the input has been validated.
+/* nsupports - what features do we support
  *
- * Normally we want debugging on (individual) sockets to be controlled
- * by the sockets own debug flag. But since we don't even have a socket
- * yet, we must use the global debug flag.
+ * This is to prove information about what features actually
+ * work on the current platform.
  */
 #if !defined(__WIN32__)
 static
@@ -3109,6 +3111,10 @@ ERL_NIF_TERM nsupports(ErlNifEnv* env, int key)
         result = nsupports_ipv6(env);
         break;
 
+    case SOCKET_SUPPORTS_LOCAL:
+        result = nsupports_local(env);
+        break;
+
     default:
         result = esock_atom_false;
         break;
@@ -4331,6 +4337,24 @@ ERL_NIF_TERM nsupports_ipv6(ErlNifEnv* env)
 
 
 
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_local(ErlNifEnv* env)
+{
+    ERL_NIF_TERM supports;
+
+#if defined(AF_LOCAL)
+    supports = esock_atom_true;
+#else
+    supports = esock_atom_false;
+#endif
+
+    return supports;
+}
+#endif
+
+
+
 /* ----------------------------------------------------------------------
  * nif_open
  *
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
index 198dd08036..266adbd6f1 100644
--- a/erts/preloaded/ebin/socket.beam
+++ b/erts/preloaded/ebin/socket.beam
diff --git a/erts/preloaded/src/socket.erl b/erts/preloaded/src/socket.erl
index 9fc73a11de..03107d22b1 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -821,6 +821,7 @@
 -define(SOCKET_SUPPORTS_OPTIONS, 16#0001).
 -define(SOCKET_SUPPORTS_SCTP,    16#0002).
 -define(SOCKET_SUPPORTS_IPV6,    16#0003).
+-define(SOCKET_SUPPORTS_LOCAL,   16#0004).
 
 
 %% ===========================================================================
@@ -876,18 +877,21 @@ info() ->
 
 -spec supports() -> [{options, supports_options()} | 
                      {sctp,    boolean()} |
-                     {ipv6,    boolean()}].
+                     {ipv6,    boolean()} |
+                     {local,   boolean()}].
 
 supports() ->
     [{options, supports(options)},
      {sctp,    supports(sctp)},
-     {ipv6,    supports(ipv6)}].
+     {ipv6,    supports(ipv6)},
+     {local,   supports(local)}].
 
 
 -dialyzer({nowarn_function, supports/1}).
 -spec supports(options) -> supports_options();
               (sctp)    -> boolean();
               (ipv6)    -> boolean();
+              (local)   -> boolean();
               (Key1)    -> false when
       Key1 :: term().
                         
@@ -897,6 +901,8 @@ supports(sctp) ->
     nif_supports(?SOCKET_SUPPORTS_SCTP);
 supports(ipv6) ->
     nif_supports(?SOCKET_SUPPORTS_IPV6);
+supports(local) ->
+    nif_supports(?SOCKET_SUPPORTS_LOCAL);
 supports(_Key1) ->
     false.