Merge branch 'netmask6' into next

This branch is a follow-up on 9ceed0926a
with clean solution. Read on for details...

The data type `ip6-prefix` used to hold what it was named for - an IPv6
prefix:

    [user@mikrotik] > :put 2001:db8::dead:beef/32
    2001:db8::/32

This changed with RouterOS 6.21beta2, which now allows that exact same
data type to hold something like "address with prefix length attached":

    [user@mikrotik] > :put 2001:db8::dead:beef/32
    2001:db8::dead:beef/32

My scripts (namely `fw-addr-lists`) relied on the old behaviour and broke.
The commit mentioned above was just a quick workaround, with rough edges,
and it could still fail.

Sadly RouterOS does not support bit shifting on IPv6 data types, so a
(completely) mathematical solution is out of scope.

This branch implements a new and better workaround, see the first commit
of branch (6ad6f9aa08) for details.

I opened a support ticket / feature request on this topic, let's see
what results it brings...

https://help.mikrotik.com/servicedesk/servicedesk/customer/portal/1/SUP-201881

fw-addr-lists.rsc

@@ -26,8 +26,8 @@
   :global LogPrint;
   :global LogPrintOnce;
   :global LogPrintVerbose;
-  :global MIN;
   :global NetMask4;
+  :global NetMask6;
   :global ScriptLock;
   :global WaitFullyConnected;
 
@@ -130,13 +130,13 @@
           }
           :if ($Address ~ "^[0-9a-zA-Z]*:[0-9a-zA-Z:\\.]+(/[0-9]{1,3})?\$") do={
             :local Net $Address;
-            :local Cidr 64;
+            :local CIDR 128;
             :local Slash [ :find $Address "/" ];
             :if ([ :typeof $Slash ] = "num") do={
               :set Net [ :toip6 [ :pick $Address 0 $Slash ] ]
-              :set Cidr [ $MIN [ :pick $Address ($Slash + 1) [ :len $Address ] ] 64 ];
+              :set CIDR [ :pick $Address ($Slash + 1) [ :len $Address ] ];
             }
-            :set Address (([ :toip6 $Net ] & ffff:ffff:ffff:ffff::) . "/" . $Cidr);
+            :set Address (([ :toip6 $Net ] & [ $NetMask6 $CIDR ]) . "/" . $CIDR);
             :set Branch [ $GetBranch $Address ];
             :set ($IPv6Addresses->$Branch->$Address) $TimeOut;
             :error true;

global-functions.rsc

@@ -62,6 +62,7 @@
 :global MIN;
 :global MkDir;
 :global NetMask4;
+:global NetMask6;
 :global NotificationFunctions;
 :global ParseDate;
 :global ParseKeyValueStore;
@@ -998,6 +999,36 @@
   :return ((255.255.255.255 << (32 - $CIDR)) & 255.255.255.255);
 }
 
+# return an IPv6 netmask for CIDR
+:set NetMask6 do={
+  :local FuncName $0;
+  :local CIDR [ :tostr $1 ];
+
+  :global IfThenElse;
+  :global MAX;
+  :global MIN;
+
+  :global NetMask6Cache;
+
+  :if ([ :typeof ($NetMask6Cache->$CIDR) ] = "ip6") do={
+    :return ($NetMask6Cache->$CIDR);
+  }
+
+  :if ([ :typeof $NetMask6Cache ] = "nothing") do={
+    :set NetMask6Cache ({});
+  }
+
+  :local Mask "";
+  :for I from=0 to=7 do={
+    :set Mask ($Mask . \
+      [ :convert from=num to=hex (0xffff - (0xffff >> [ :tonum [ $MIN [ $MAX ($CIDR - (16 * $I)) 0 ] 16 ] ])) ] . \
+      [ $IfThenElse ($I < 7) ":" ]);
+  }
+  :set Mask [ :toip6 $Mask ];
+  :set ($NetMask6Cache->$CIDR) $Mask;
+  :return $Mask;
+}
+
 # prepare NotificationFunctions array
 :if ([ :typeof $NotificationFunctions ] != "array") do={
   :set NotificationFunctions ({});

mod/ipcalc.rsc

@@ -36,21 +36,32 @@
   :local Input [ :tostr $1 ];
 
   :global NetMask4;
+  :global NetMask6;
 
-  :local Address [ :toip [ :pick $Input 0 [ :find $Input "/" ] ] ];
+  :local Address [ :pick $Input 0 [ :find $Input "/" ] ];
   :local Bits [ :tonum [ :pick $Input ([ :find $Input "/" ] + 1) [ :len $Input ] ] ];
-  :local Mask [ $NetMask4 $Bits ];
+  :local Mask;
+  :local One;
+  :if ([ :typeof [ :toip $Address ] ] = "ip") do={
+    :set Address [ :toip $Address ];
+    :set Mask [ $NetMask4 $Bits ];
+    :set One 0.0.0.1;
+  } else={
+    :set Address [ :toip6 $Address ];
+    :set Mask [ $NetMask6 $Bits ];
+    :set One ::1;
+  }
 
-  :local Return {
+  :local Return ({
     "address"=$Address;
     "netmask"=$Mask;
     "networkaddress"=($Address & $Mask);
     "networkbits"=$Bits;
     "network"=(($Address & $Mask) . "/" . $Bits);
-    "hostmin"=(($Address & $Mask) | 0.0.0.1);
-    "hostmax"=(($Address | ~$Mask) ^ 0.0.0.1);
+    "hostmin"=(($Address & $Mask) | $One);
+    "hostmax"=(($Address | ~$Mask) ^ $One);
     "broadcast"=($Address | ~$Mask);
-  }
+  });
 
   :return $Return;
 }