Wildcard (subnet) ban support for IPv4 & IPv6 with trailing * notation (#28)

This enables banning entire subnets or address groups, with documentation and usage examples updated in the README. No changes to command structure or database, all bans work with standard xban commands.

init.lua

@@ -49,25 +49,29 @@ local function concat_keys(t, sep)
 	return table.concat(keys, sep)
 end
 
-function xban.find_entry(player, create) --> entry, index
-	for index, e in ipairs(db) do
-		for name in pairs(e.names) do
-			if name == player then
-				return e, index
-			end
-		end
-	end
-	if create then
-		print(("Created new entry for `%s'"):format(player))
-		local e = {
-			names = { [player]=true },
-			banned = false,
-			record = { },
-		}
-		table.insert(db, e)
-		return e, #db
-	end
-	return nil
+-- supports wildcard IP pattern (both IPv4 and IPv6)
+function xban.find_entry(key, create)
+    -- exact match (player or IP)
+    for i, e in ipairs(xban.db) do
+        if e.names[key] then return e, i end
+    end
+    -- wildcard pattern match for IPs
+    if key and key:find("[.:]") then
+        for i, e in ipairs(xban.db) do
+            for name in pairs(e.names) do
+	            local wildcard_prefix = name:match("(.+[.:])%*$")
+	            if wildcard_prefix and key:sub(1, #wildcard_prefix) == wildcard_prefix then
+	                return e, i
+	            end
+	        end
+        end
+    end
+    if create then
+        local e = { names = { [key] = true }, bans = {} }
+        table.insert(xban.db, e)
+        return e, #xban.db
+    end
+    return nil
 end
 
 function xban.get_info(player) --> ip_name_list, banned, last_record