[socket-nif] Add support for socket (level ipv6) option rthdr

Added support for the IPv6 socket option RTHDR.
On FreeBSD this option requires superuser privileges to update.
There is no mention of this on linux, but its still not possible
to update (einval), so I assume that its the same there.

OTP-14831.

4 files changed, 82 insertions, 7 deletions

diff --git a/erts/doc/src/socket_usage.xml b/erts/doc/src/socket_usage.xml
index 78662e7d0d..b3ee38dbcb 100644
--- a/erts/doc/src/socket_usage.xml
+++ b/erts/doc/src/socket_usage.xml
@@ -475,6 +475,13 @@
 	<cell>type = dgram | raw</cell>
       </row>
       <row>
+	<cell>rthdr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, requires superuser privileges to update</cell>
+      </row>
+      <row>
 	<cell>v6only</cell>
 	<cell>boolean()</cell>
 	<cell>yes</cell>
diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
index 35997c359d..f4ac43a9cd 100644
--- a/erts/emulator/nifs/common/socket_nif.c
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -544,6 +544,7 @@ typedef union {
 #define SOCKET_OPT_IPV6_MULTICAST_IF         20
 #define SOCKET_OPT_IPV6_MULTICAST_LOOP       21
 #define SOCKET_OPT_IPV6_RECVPKTINFO          25 // PKTINFO on FreeBSD
+#define SOCKET_OPT_IPV6_RTHDR                28
 #define SOCKET_OPT_IPV6_V6ONLY               32
 
 #define SOCKET_OPT_TCP_CONGESTION   1
@@ -1240,6 +1241,11 @@ static ERL_NIF_TERM nsetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
                                                  SocketDescriptor* descP,
                                                  ERL_NIF_TERM      eVal);
 #endif
+#if defined(IPV6_RTHDR)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
 #if defined(IPV6_V6ONLY)
 static ERL_NIF_TERM nsetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
                                             SocketDescriptor* descP,
@@ -1545,6 +1551,10 @@ static ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_loop(ErlNifEnv*        env,
 static ERL_NIF_TERM ngetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
                                                  SocketDescriptor* descP);
 #endif
+#if defined(IPV6_RTHDR)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
 #if defined(IPV6_V6ONLY)
 static ERL_NIF_TERM ngetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
                                             SocketDescriptor* descP);
@@ -4323,9 +4333,10 @@ ERL_NIF_TERM nsetopt_native(ErlNifEnv*        env,
 
     SSDBG( descP,
            ("SOCKET", "nsetopt_native -> entry with"
-            "\r\n   opt:  %d"
-            "\r\n   eVal: %T"
-            "\r\n", opt, eVal) );
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n   eVal:  %T"
+            "\r\n", level, opt, eVal) );
 
     if (GET_BIN(env, eVal, &val)) {
         int res = socket_setopt(descP->sock, level, opt,
@@ -4338,6 +4349,11 @@ ERL_NIF_TERM nsetopt_native(ErlNifEnv*        env,
         result = esock_make_error(env, esock_atom_einval);
     }
 
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_native -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
     return result;
 }
 
@@ -4393,10 +4409,17 @@ ERL_NIF_TERM nsetopt_level(ErlNifEnv*        env,
 #endif
 
     default:
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_level -> unknown level (%d)\r\n", level) );
         result = esock_make_error(env, esock_atom_einval);
         break;
     }
 
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_level -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
     return result;
 }
 
@@ -4527,6 +4550,8 @@ ERL_NIF_TERM nsetopt_lvl_socket(ErlNifEnv*        env,
 #endif
 
     default:
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_lvl_socket -> unknown opt (%d)\r\n", eOpt) );
         result = esock_make_error(env, esock_atom_einval);
         break;
     }
@@ -5572,6 +5597,12 @@ ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
         break;
 #endif
 
+#if defined(IPV6_RTHDR)
+    case SOCKET_OPT_IPV6_RTHDR:
+        result = nsetopt_lvl_ipv6_rthdr(env, descP, eVal);
+        break;
+#endif
+
 #if defined(IPV6_V6ONLY)
     case SOCKET_OPT_IPV6_V6ONLY:
         result = nsetopt_lvl_ipv6_v6only(env, descP, eVal);
@@ -5579,10 +5610,17 @@ ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
 #endif
 
     default:
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_lvl_ipv6 -> unknown opt (%d)\r\n", eOpt) );
         result = esock_make_error(env, esock_atom_einval);
         break;
     }
 
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6 -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
     return result;
 }
 
@@ -5721,6 +5759,17 @@ ERL_NIF_TERM nsetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
 #endif
 
 
+#if defined(IPV6_RTHDR)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_IPV6, IPV6_RTHDR, eVal);
+}
+#endif
+
+
 #if defined(IPV6_V6ONLY)
 static
 ERL_NIF_TERM nsetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
@@ -8090,6 +8139,12 @@ ERL_NIF_TERM ngetopt_lvl_ipv6(ErlNifEnv*        env,
         break;
 #endif
 
+#if defined(IPV6_RTHDR)
+    case SOCKET_OPT_IPV6_RTHDR:
+        result = ngetopt_lvl_ipv6_rthdr(env, descP);
+        break;
+#endif
+
 #if defined(IPV6_V6ONLY)
     case SOCKET_OPT_IPV6_V6ONLY:
         result = ngetopt_lvl_ipv6_v6only(env, descP);
@@ -8205,6 +8260,16 @@ ERL_NIF_TERM ngetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
 #endif
 
 
+#if defined(IPV6_RTHDR)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_IPV6, IPV6_RTHDR);
+}
+#endif
+
+
 #if defined(IPV6_V6ONLY)
 static
 ERL_NIF_TERM ngetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
index 15bc762ae9..1873289486 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 7e9b61ba8f..d2267192e5 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -657,7 +657,7 @@
 -define(SOCKET_OPT_IPV6_RECVPKTINFO,       25). % On FreeBSD: PKTINFO
 %% -define(SOCKET_OPT_IPV6_RECVTCLASS,        26).
 %% -define(SOCKET_OPT_IPV6_ROUTER_ALERT,      27).
-%% -define(SOCKET_OPT_IPV6_RTHDR,             28).
+-define(SOCKET_OPT_IPV6_RTHDR,             28).
 %% -define(SOCKET_OPT_IPV6_TCLASS,            29).
 %% -define(SOCKET_OPT_IPV6_UNICAST_HOPS,      30).
 %% -define(SOCKET_OPT_IPV6_USE_MIN_MTU,       31).
@@ -2282,6 +2282,9 @@ enc_setopt_value(ipv6, Opt, V, _D, _T, _P)
   when ((Opt =:= recvpktinfo) orelse (Opt =:= pktinfo)) andalso 
        is_boolean(V) ->
     V;
+enc_setopt_value(ipv6, rthdr, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
 enc_setopt_value(ipv6, v6only, V, _D, _T, _P) when is_boolean(V) ->
     V;
 enc_setopt_value(ipv6 = L, Opt, V, _D, _T, _P) ->
@@ -2727,9 +2730,9 @@ enc_sockopt_key(ipv6 = L, recvtclass = Opt, _Dir, _D, _T, _P) ->
     not_supported({L, Opt});
 enc_sockopt_key(ipv6 = L, router_alert = Opt, _Dir, _D, _T, _P) ->
     not_supported({L, Opt});
-enc_sockopt_key(ipv6 = L, rthdr = Opt, set = _Dir, _D, T, _P) 
+enc_sockopt_key(ipv6 = _L, rthdr = _Opt, _Dir, _D, T, _P) 
   when ((T =:= dgram) orelse (T =:= raw)) ->
-    not_supported({L, Opt});
+    ?SOCKET_OPT_IPV6_RTHDR;
 enc_sockopt_key(ipv6 = L, tclass = Opt, _Dir, _D, _T, _P) ->
     not_supported({L, Opt});
 enc_sockopt_key(ipv6 = L, unicast_hops = Opt, _Dir, _D, _T, _P) ->
@@ -2739,7 +2742,7 @@ enc_sockopt_key(ipv6 = L, use_min_mtu = Opt, _Dir, _D, _T, _P) ->
 enc_sockopt_key(ipv6 = _L, v6only = _Opt, _Dir, _D, _T, _P) ->
     ?SOCKET_OPT_IPV6_V6ONLY;
 enc_sockopt_key(ipv6 = L, UnknownOpt, _Dir, _D, _T, _P) ->
-    unknown({L, UnknownOpt});
+    unknown({L, UnknownOpt, _Dir, _D, _T, _P});
 
 %% TCP socket options
 %% There are other options that would be useful; info,