If we try to fetch a record from cache and need to look into
hints database we assume that the resolver is not primed and
start dns_resolver_prime(). Priming query is supposed to return
NSes for "." in ANSWER section and glue records for them in
ADDITIONAL section, so that we can fill that info in 'regular'
cache and not use hints db anymore.
However, if we're using a forwarder the priming query goes through
it, and if it's configured to return minimal answers we won't get
the addresses of root servers in ADDITIONAL section. Since the
only records for root servers we have are in hints database we'll
try to prime the resolver with every single query.
This patch adds a DNS_FETCHOPT_NOFORWARD flag which avoids using
forwarders if possible (that is if we have forward-first policy).
Using this flag on priming fetch fixes the problem as we get the
proper glue. With forward-only policy the problem is non-existent,
as we'll never ask for root server addresses because we'll never
have a need to query them.
Also added a test to confirm priming queries are not forwarded.
(cherry picked from commit b49310ac06)
(cherry picked from commit f8963ad70e)
Since following a delegation resets most fetch context state, address
marks (FCTX_ADDRINFO_MARK) set inside lib/dns/resolver.c are not
preserved when a delegation is followed. This is fine for full
recursive resolution but when named is configured with "forward first;"
and one of the specified forwarders times out, triggering a fallback to
full recursive resolution, that forwarder should no longer be consulted
at each delegation point subsequently reached within a given fetch
context.
Add a new badnstype_t enum value, badns_forwarder, and use it to mark a
forwarder as bad when it times out in a "forward first;" configuration.
Since the bad server list is not cleaned when a fetch context follows a
delegation, this prevents a forwarder from being queried again after
falling back to full recursive resolution. Yet, as each fetch context
maintains its own list of bad servers, this change does not cause a
forwarder timeout to prevent that forwarder from being used by other
fetch contexts.
(cherry picked from commit 33350626f9)
dnssec-signzone should sign a zonefile that contains a DNSKEY record
with an unsupported algorithm. Current behavior is that it will
fail, hitting a fatal error. The fix detects unsupported algorithms
and will not try to add it to the keylist.
Also when determining the maximum iterations for NSEC3, don't take
into account DNSKEY records in the zonefile with an unsupported
algorithm.
(cherry picked from commit 1dd11fc754)
