diff options
| -rw-r--r-- | plugin/cache/item.go | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/plugin/cache/item.go b/plugin/cache/item.go index 3071f1512..e3da5bb14 100644 --- a/plugin/cache/item.go +++ b/plugin/cache/item.go @@ -49,7 +49,12 @@ func newItem(m *dns.Msg, now time.Time, d time.Duration) *item { } // toMsg turns i into a message, it tailors the reply to m. -// The Authoritative bit is always set to 0, because the answer is from the cache. +// The Authoritative bit should be set to 0, but some client stub resolver implementations, most notably, +// on some legacy systems(e.g. ubuntu 14.04 with glib version 2.20), low-level glibc function `getaddrinfo` +// useb by Python/Ruby/etc.. will discard answers that do not have this bit set. +// So we're forced to always set this to 1; regardless if the answer came from the cache or not. +// On newer systems(e.g. ubuntu 16.04 with glib version 2.23), this issue is resolved. +// So we may set this bit back to 0 in the future ? func (i *item) toMsg(m *dns.Msg, now time.Time) *dns.Msg { m1 := new(dns.Msg) m1.SetReply(m) |