libs/web: relax validation for hostnames to allow names like _kerberos._udp.EXAMPLE.COM

[project/luci.git] / libs / web / luasrc / cbi / datatypes.lua

diff --git a/libs/web/luasrc/cbi/datatypes.lua b/libs/web/luasrc/cbi/datatypes.lua
index 4858619..32530c4 100644 (file)
--- a/libs/web/luasrc/cbi/datatypes.lua
+++ b/libs/web/luasrc/cbi/datatypes.lua
@@ -179,8 +179,8 @@ end
 
 function hostname(val)
        if val and (#val < 254) and (
-          val:match("^[a-zA-Z]+$") or
-          (val:match("^[a-zA-Z0-9][a-zA-Z0-9%-%.]*[a-zA-Z0-9]$") and
+          val:match("^[a-zA-Z_]+$") or
+          (val:match("^[a-zA-Z0-9_][a-zA-Z0-9_%-%.]*[a-zA-Z0-9]$") and
            val:match("[^0-9%.]"))
        ) then
                return true