[socket-nif] Add support for socket (level ip) option transparent

Added support for ip level socket option TRANSPARENT.

OTP-14831

4 files changed, 81 insertions, 4 deletions

diff --git a/erts/doc/src/socket_usage.xml b/erts/doc/src/socket_usage.xml
index 443d4edec7..b1fe22b231 100644
--- a/erts/doc/src/socket_usage.xml
+++ b/erts/doc/src/socket_usage.xml
@@ -412,7 +412,14 @@
 	<cell>ip_tos()</cell>
 	<cell>yes</cell>
 	<cell>yes</cell>
-	<cell>none</cell>
+	<cell>may require admin capability</cell>
+      </row>
+      <row>
+	<cell>transparent</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>require admin capability</cell>
       </row>
       <row>
 	<cell>ttl</cell>
diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
index f4da7cdbb0..9e9ac333e7 100644
--- a/erts/emulator/nifs/common/socket_nif.c
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -538,6 +538,7 @@ typedef union {
 #define SOCKET_OPT_IP_RECVTTL                26
 #define SOCKET_OPT_IP_ROUTER_ALERT           28
 #define SOCKET_OPT_IP_TOS                    30
+#define SOCKET_OPT_IP_TRANSPARENT            31
 #define SOCKET_OPT_IP_TTL                    32
 #define SOCKET_OPT_IP_UNBLOCK_SOURCE         33
 
@@ -1204,6 +1205,11 @@ static ERL_NIF_TERM nsetopt_lvl_ip_tos(ErlNifEnv*        env,
                                        SocketDescriptor* descP,
                                        ERL_NIF_TERM      eVal);
 #endif
+#if defined(IP_TRANSPARENT)
+static ERL_NIF_TERM nsetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
 #if defined(IP_TTL)
 static ERL_NIF_TERM nsetopt_lvl_ip_ttl(ErlNifEnv*        env,
                                        SocketDescriptor* descP,
@@ -1608,6 +1614,10 @@ static ERL_NIF_TERM ngetopt_lvl_ip_router_alert(ErlNifEnv*        env,
 static ERL_NIF_TERM ngetopt_lvl_ip_tos(ErlNifEnv*        env,
                                        SocketDescriptor* descP);
 #endif
+#if defined(IP_TRANSPARENT)
+static ERL_NIF_TERM ngetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
 #if defined(IP_TTL)
 static ERL_NIF_TERM ngetopt_lvl_ip_ttl(ErlNifEnv*        env,
                                        SocketDescriptor* descP);
@@ -5073,6 +5083,12 @@ ERL_NIF_TERM nsetopt_lvl_ip(ErlNifEnv*        env,
         break;
 #endif
 
+#if defined(IP_TRANSPARENT)
+    case SOCKET_OPT_IP_TRANSPARENT:
+        result = nsetopt_lvl_ip_transparent(env, descP, eVal);
+        break;
+#endif
+
 #if defined(IP_TTL)
     case SOCKET_OPT_IP_TTL:
         result = nsetopt_lvl_ip_ttl(env, descP, eVal);
@@ -5086,10 +5102,16 @@ ERL_NIF_TERM nsetopt_lvl_ip(ErlNifEnv*        env,
 #endif
 
     default:
+        SSDBG( descP, ("SOCKET", "nsetopt_lvl_ip -> unknown opt (%d)\r\n", eOpt) );
         result = esock_make_error(env, esock_atom_einval);
         break;
     }
 
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ip -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
     return result;
 }
 
@@ -5714,6 +5736,26 @@ ERL_NIF_TERM nsetopt_lvl_ip_tos(ErlNifEnv*        env,
 #endif
 
 
+/* nsetopt_lvl_ip_transparent - Level IP TRANSPARENT option
+ */
+#if defined(IP_TRANSPARENT)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_TRANSPARENT, eVal);
+}
+#endif
+
+
+
 /* nsetopt_lvl_ip_ttl - Level IP TTL option
  */
 #if defined(IP_TTL)
@@ -8259,6 +8301,12 @@ ERL_NIF_TERM ngetopt_lvl_ip(ErlNifEnv*        env,
         break;
 #endif
 
+#if defined(IP_TRANSPARENT)
+    case SOCKET_OPT_IP_TRANSPARENT:
+        result = ngetopt_lvl_ip_transparent(env, descP);
+        break;
+#endif
+
 #if defined(IP_TTL)
     case SOCKET_OPT_IP_TTL:
         result = ngetopt_lvl_ip_ttl(env, descP);
@@ -8651,6 +8699,25 @@ ERL_NIF_TERM ngetopt_lvl_ip_tos(ErlNifEnv*        env,
 #endif
 
 
+/* ngetopt_lvl_ip_transparent - Level IP TRANSPARENT option
+ */
+#if defined(IP_TRANSPARENT)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_TRANSPARENT);
+}
+#endif
+
+
+
 /* ngetopt_lvl_ip_ttl - Level IP TTL option
  */
 #if defined(IP_TTL)
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
index b5b18e1c3a..960a465fb6 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 28931e4ed0..c7589cbd48 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -644,7 +644,7 @@
 -define(SOCKET_OPT_IP_ROUTER_ALERT,          28).
 %% -define(SOCKET_OPT_IP_SNDSRCADDR,            29).
 -define(SOCKET_OPT_IP_TOS,                   30).
-%% -define(SOCKET_OPT_IP_TRANSPARENT,           31).
+-define(SOCKET_OPT_IP_TRANSPARENT,           31).
 -define(SOCKET_OPT_IP_TTL,                   32).
 -define(SOCKET_OPT_IP_UNBLOCK_SOURCE,           33).
 
@@ -2274,6 +2274,9 @@ enc_setopt_value(ip, tos, V, _D, _T, _P)
        (V =:= mincost)     orelse
        is_integer(V) ->
     V;
+enc_setopt_value(ip, transparent, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
 enc_setopt_value(ip, ttl, V, _D, _T, _P)
   when is_integer(V) ->
     V;
@@ -2731,8 +2734,8 @@ enc_sockopt_key(ip, router_alert = _Opt, _Dir, _D, raw = _T, _P) ->
 %% No such condition on linux (in the man page)...
 enc_sockopt_key(ip, tos = _Opt, _Dir, _D, _T, _P) ->
     ?SOCKET_OPT_IP_TOS;
-enc_sockopt_key(ip = L, transparent = Opt, _Dir, _D, _T, _P) ->
-    not_supported({L, Opt});
+enc_sockopt_key(ip = _L, transparent = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_TRANSPARENT;
 enc_sockopt_key(ip, ttl = _Opt, _Dir, _D, _T, _P) ->
     ?SOCKET_OPT_IP_TTL;
 enc_sockopt_key(ip = _L, unblock_source = _Opt, set = _Dir, _D, _T, _P) ->