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

Added support for the IPv6 socket option ADDRFORM.
Only allowed for IPv6 sockets that are connected and bound to a
v4-mapped-on-v6 address.

OTP-14831.

4 files changed, 67 insertions, 3 deletions

diff --git a/erts/doc/src/socket_usage.xml b/erts/doc/src/socket_usage.xml
index 1423571f5c..8480af315e 100644
--- a/erts/doc/src/socket_usage.xml
+++ b/erts/doc/src/socket_usage.xml
@@ -412,6 +412,14 @@
 	<cell><em>Other</em></cell>
       </row>
       <row>
+	<cell>addrform</cell>
+	<cell>inet</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>allowed only for IPv6 sockets that are connected and bound to a
+	v4-mapped-on-v6 address</cell>
+      </row>
+      <row>
 	<cell>add_membership</cell>
 	<cell>ipv6_mreq()</cell>
 	<cell>yes</cell>
diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
index 4d78e89a4f..f7053d77fa 100644
--- a/erts/emulator/nifs/common/socket_nif.c
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -537,6 +537,7 @@ typedef union {
 #define SOCKET_OPT_IP_TTL                    32
 #define SOCKET_OPT_IP_UNBLOCK_SOURCE         33
 
+#define SOCKET_OPT_IPV6_ADDRFORM              1
 #define SOCKET_OPT_IPV6_ADD_MEMBERSHIP        2
 #define SOCKET_OPT_IPV6_AUTHHDR               3
 #define SOCKET_OPT_IPV6_DROP_MEMBERSHIP       6
@@ -1204,6 +1205,11 @@ static ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
                                      SocketDescriptor* descP,
                                      int               eOpt,
                                      ERL_NIF_TERM      eVal);
+#if defined(IPV6_ADDRFORM)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_addrform(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
 #if defined(IPV6_ADD_MEMBERSHIP)
 static ERL_NIF_TERM nsetopt_lvl_ipv6_add_membership(ErlNifEnv*        env,
                                                     SocketDescriptor* descP,
@@ -5607,6 +5613,12 @@ ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
             "\r\n", eOpt) );
 
     switch (eOpt) {
+#if defined(IPV6_ADDRFORM)
+    case SOCKET_OPT_IPV6_ADDRFORM:
+        result = nsetopt_lvl_ipv6_addrform(env, descP, eVal);
+        break;
+#endif
+
 #if defined(IPV6_ADD_MEMBERSHIP)
     case SOCKET_OPT_IPV6_ADD_MEMBERSHIP:
         result = nsetopt_lvl_ipv6_add_membership(env, descP, eVal);
@@ -5725,6 +5737,48 @@ ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
 }
 
 
+#if defined(IPV6_ADDRFORM)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_addrform(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+    int          res, edomain, domain;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6_addrform -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    if (!GET_INT(env, eVal, &edomain))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6_addrform -> decode"
+            "\r\n   edomain: %d"
+            "\r\n", edomain) );
+
+    if (!edomain2domain(edomain, &domain))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP, ("SOCKET", "nsetopt_lvl_ipv6_addrform -> try set opt to %d\r\n",
+                   domain) );
+    
+    res = socket_setopt(descP->sock,
+                        SOL_IPV6, IPV6_ADDRFORM,
+                        &domain, sizeof(domain));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
 #if defined(IPV6_ADD_MEMBERSHIP)
 static
 ERL_NIF_TERM nsetopt_lvl_ipv6_add_membership(ErlNifEnv*        env,
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
index cdc403055b..20f2cf659b 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 82a51ee245..0c3a17b54d 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -635,7 +635,7 @@
 -define(SOCKET_OPT_IP_TTL,                   32).
 -define(SOCKET_OPT_IP_UNBLOCK_SOURCE,           33).
 
-%% -define(SOCKET_OPT_IPV6_ADDFORM,            1).
+-define(SOCKET_OPT_IPV6_ADDRFORM,           1).
 -define(SOCKET_OPT_IPV6_ADD_MEMBERSHIP,     2).
 -define(SOCKET_OPT_IPV6_AUTHHDR,            3). % Obsolete?
 %% -define(SOCKET_OPT_IPV6_AUTH_LEVEL,         4).
@@ -2254,6 +2254,8 @@ enc_setopt_value(ip, unblock_source, #{multiaddr  := MA,
 enc_setopt_value(ip = L, Opt, V, _D, _T, _P) ->
     not_supported({L, Opt, V});
 
+enc_setopt_value(ipv6, addrform, inet = V, _D, _T, _P) ->
+    enc_domain(V);
 enc_setopt_value(ipv6, add_membership, #{multiaddr := MA,
                                          interface := IF} = V, _D, _T, _P)
   when ((is_tuple(MA) andalso (size(MA) =:= 8)) andalso
@@ -2704,8 +2706,8 @@ enc_sockopt_key(ip = L, UnknownOpt, _Dir, _D, _T, _P) ->
     unknown({L, UnknownOpt});
 
 %% IPv6 socket options
-enc_sockopt_key(ipv6 = L, addrform = Opt, set = _Dir, _D, _T, _P) ->
-    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, addrform = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_ADDRFORM;
 enc_sockopt_key(ipv6, add_membership = _Opt, set = _Dir, _D, _T, _P) ->
     ?SOCKET_OPT_IPV6_ADD_MEMBERSHIP;
 enc_sockopt_key(ipv6 = _L, authhdr = _Opt, _Dir, _D, T, _P)