modules/dns64: allow configuring by a table

Backward compatible.  It will be useful when adding further features.
Also improve config error traces.

diff --git a/modules/dns64/dns64.lua b/modules/dns64/dns64.lua
index a389b7837276b4af37d03f7b4e6435081f045075..7f84d82e70ad2b57af75daa201ac19121fd90295 100644 (file)
--- a/modules/dns64/dns64.lua
+++ b/modules/dns64/dns64.lua
@@ -19,9 +19,14 @@ Missing parts of the RFC:
 ]]
 
 -- Config
-function M.config (confstr)
-       M.proxy = kres.str2ip(confstr or '64:ff9b::')
-       if M.proxy == nil then error('[dns64] "'..confstr..'" is not a valid address') end
+function M.config(conf)
+       if type(conf) ~= 'table' then
+               conf = { prefix = conf }
+       end
+       M.proxy = kres.str2ip(tostring(conf.prefix or '64:ff9b::'))
+       if M.proxy == nil or #M.proxy ~= 16 then
+               error(string.format('[dns64] %q is not a valid IPv6 address', conf.prefix), 2)
+       end
 end
 
 -- Layers