diff options
Diffstat (limited to 'core/dnsserver/onstartup.go')
| -rw-r--r-- | core/dnsserver/onstartup.go | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/core/dnsserver/onstartup.go b/core/dnsserver/onstartup.go index 113bf15e5..b016f1ee5 100644 --- a/core/dnsserver/onstartup.go +++ b/core/dnsserver/onstartup.go @@ -2,9 +2,22 @@ package dnsserver import ( "fmt" + "regexp" "sort" + + "github.com/coredns/coredns/plugin/pkg/dnsutil" ) +// checkZoneSyntax() checks whether the given string match 1035 Preferred Syntax or not. +// The root zone, and all reverse zones always return true even though they technically don't meet 1035 Preferred Syntax +func checkZoneSyntax(zone string) bool { + if zone == "." || dnsutil.IsReverse(zone) != 0 { + return true + } + regex1035PreferredSyntax, _ := regexp.MatchString(`^(([A-Za-z]([A-Za-z0-9-]*[A-Za-z0-9])?)\.)+$`, zone) + return regex1035PreferredSyntax +} + // startUpZones creates the text that we show when starting up: // grpc://example.com.:1055 // example.com.:1053 on 127.0.0.1 @@ -13,6 +26,7 @@ func startUpZones(protocol, addr string, zones map[string]*Config) string { keys := make([]string, len(zones)) i := 0 + for k := range zones { keys[i] = k i++ @@ -20,6 +34,9 @@ func startUpZones(protocol, addr string, zones map[string]*Config) string { sort.Strings(keys) for _, zone := range keys { + if !checkZoneSyntax(zone) { + s += fmt.Sprintf("Warning: Domain %q does not follow RFC1035 preferred syntax\n", zone) + } // split addr into protocol, IP and Port _, ip, port, err := SplitProtocolHostPort(addr) |