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

Added support for the IPv6 socket option UNICAST_HOPS.

OTP-14831.

4 files changed, 60 insertions, 3 deletions

diff --git a/erts/doc/src/socket_usage.xml b/erts/doc/src/socket_usage.xml
index 09a65c7152..383aebdab1 100644
--- a/erts/doc/src/socket_usage.xml
+++ b/erts/doc/src/socket_usage.xml
@@ -510,6 +510,13 @@
 	<cell>type = dgram | raw, requires superuser privileges to update</cell>
       </row>
       <row>
+	<cell>unicast_hops</cell>
+	<cell>default | uint8()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</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 6a2904f75f..5aba0bca03 100644
--- a/erts/emulator/nifs/common/socket_nif.c
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -549,6 +549,7 @@ typedef union {
 #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_UNICAST_HOPS         30
 #define SOCKET_OPT_IPV6_V6ONLY               32
 
 #define SOCKET_OPT_TCP_CONGESTION   1
@@ -1270,6 +1271,11 @@ static ERL_NIF_TERM nsetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
                                            SocketDescriptor* descP,
                                            ERL_NIF_TERM      eVal);
 #endif
+#if defined(IPV6_UNICAST_HOPS)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_unicast_hops(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,
@@ -1595,6 +1601,10 @@ static ERL_NIF_TERM ngetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
 static ERL_NIF_TERM ngetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
                                            SocketDescriptor* descP);
 #endif
+#if defined(IPV6_UNICAST_HOPS)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
 #if defined(IPV6_V6ONLY)
 static ERL_NIF_TERM ngetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
                                             SocketDescriptor* descP);
@@ -5667,6 +5677,12 @@ ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
         break;
 #endif
 
+#if defined(IPV6_UNICAST_HOPS)
+    case SOCKET_OPT_IPV6_UNICAST_HOPS:
+        result = nsetopt_lvl_ipv6_unicast_hops(env, descP, eVal);
+        break;
+#endif
+
 #if defined(IPV6_V6ONLY)
     case SOCKET_OPT_IPV6_V6ONLY:
         result = nsetopt_lvl_ipv6_v6only(env, descP, eVal);
@@ -5878,6 +5894,18 @@ ERL_NIF_TERM nsetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
 #endif
 
 
+#if defined(IPV6_UNICAST_HOPS)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_IPV6, IPV6_UNICAST_HOPS, eVal);
+}
+#endif
+
+
+
 #if defined(IPV6_V6ONLY)
 static
 ERL_NIF_TERM nsetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
@@ -8277,6 +8305,12 @@ ERL_NIF_TERM ngetopt_lvl_ipv6(ErlNifEnv*        env,
         break;
 #endif
 
+#if defined(IPV6_UNICAST_HOPS)
+    case SOCKET_OPT_IPV6_UNICAST_HOPS:
+        result = ngetopt_lvl_ipv6_unicast_hops(env, descP);
+        break;
+#endif
+
 #if defined(IPV6_V6ONLY)
     case SOCKET_OPT_IPV6_V6ONLY:
         result = ngetopt_lvl_ipv6_v6only(env, descP);
@@ -8442,6 +8476,16 @@ ERL_NIF_TERM ngetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
 #endif
 
 
+#if defined(IPV6_UNICAST_HOPS)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                             SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_IPV6, IPV6_UNICAST_HOPS);
+}
+#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 f0788f2378..5ab64f442f 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 95bd5ce094..3bc3c7dc28 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -659,7 +659,7 @@
 %% -define(SOCKET_OPT_IPV6_ROUTER_ALERT,      27).
 -define(SOCKET_OPT_IPV6_RTHDR,             28).
 %% -define(SOCKET_OPT_IPV6_TCLASS,            29).
-%% -define(SOCKET_OPT_IPV6_UNICAST_HOPS,      30).
+-define(SOCKET_OPT_IPV6_UNICAST_HOPS,      30).
 %% -define(SOCKET_OPT_IPV6_USE_MIN_MTU,       31).
 -define(SOCKET_OPT_IPV6_V6ONLY,            32).
 
@@ -2300,6 +2300,12 @@ enc_setopt_value(ipv6, Opt, V, _D, _T, _P)
 enc_setopt_value(ipv6, rthdr, V, _D, T, _P)
   when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
     V;
+enc_setopt_value(ipv6, unicast_hops, V, _D, _T, _P)
+  when (V =:= default) ->
+    -1;
+enc_setopt_value(ipv6, unicast_hops, V, _D, _T, _P)
+  when is_integer(V) andalso (V >= 0) andalso (V =< 255) ->
+    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) ->
@@ -2750,8 +2756,8 @@ enc_sockopt_key(ipv6 = _L, rthdr = _Opt, _Dir, _D, T, _P)
     ?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) ->
-    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, unicast_hops = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_UNICAST_HOPS;
 enc_sockopt_key(ipv6 = L, use_min_mtu = Opt, _Dir, _D, _T, _P) ->
     not_supported({L, Opt});
 enc_sockopt_key(ipv6 = _L, v6only = _Opt, _Dir, _D, _T, _P) ->