In case when a zone fails to load because the file does not exist
or is malformed, we should not run the callback that updates the
zone database when the load is done. This is achieved by
unregistering the callbacks if at zone load end if the result
indicates something else than success.
As pointed out in !813 db_registered is sort of redundant. It is
set to `true` only in `dns_zone_rpz_enable_db()` right before the
`dns_rpz_dbupdate_callback()` callback is registered. It is only
required in that callback and it is the only place that the callback
is registered. Therefore there is no path that that `REQUIRE` can
fail.
The `db_registered` variable is only set to `false` in
`dns_rpz_new_zone`, so it is not like the variable is unset again
later.
The only other place where `db_registered` is checked is in
`rpz_detach()`. If `true`, it will call
`dns_db_updatenotify_unregister()`. However if that happens, the
`db_registered` is not set back to `false` thus this implies that
this may happen multiple times. If called a second time, most
likely the unregister function will return `ISC_R_NOTFOUND`, but
the return value is not checked anyway. So it can do without the
`db_registered` check.
This may happen when loading an RPZ failed and the code path skips
calling dns_db_endload(). The dns_rpz_zone_t object is still kept
marked as having registered db. So when this object is finally
destroyed in rpz_detach(), this code will incorrectly call
`dns_db_updatenotify_unregister()`:
if (rpz->db_registered)
dns_db_updatenotify_unregister(rpz->db,
dns_rpz_dbupdate_callback, rpz);
and trigger this assertion failure:
REQUIRE(db != NULL);
To fix this, only call `dns_db_updatenotify_unregister()` when
`rpz->db` is not NULL.
If `dns_dnssec_keyfromrdata` failed we don't need to call
`dst_key_free` because no `dstkey` was created. Doing so
nevertheless will result in an assertion failure.
This can happen if the key uses an unsupported algorithm.
When a mirror zone is verified, the 'ignore_kskflag' argument passed to
dns_zoneverify_dnssec() is set to false. This means that in order for
its verification to succeed, a mirror zone needs to have at least one
key with the SEP bit set configured as a trust anchor. This brings no
security benefit and prevents zones signed only using keys without the
SEP bit set from being mirrored, so change the value of the
'ignore_kskflag' argument passed to dns_zoneverify_dnssec() to true.
The "mirror" system test checks whether log messages announcing a mirror
zone coming into effect are emitted properly. However, the helper
functions responsible for waiting for zone transfers and zone loading to
complete do not wait for these exact log messages, but rather for other
ones preceding them, which introduces a possibility of false positives.
This problem cannot be addressed by just changing the log message to
look for because the test still needs to discern between transferring a
zone and loading a zone.
Add two new log messages at debug level 99 (which is what named
instances used in system tests are configured with) that are to be
emitted after the log messages announcing a mirror zone coming into
effect. Tweak the aforementioned helper functions to only return once
the log messages they originally looked for are followed by the newly
added log messages. This reliably prevents races when looking for
"mirror zone is now in use" log messages and also enables a workaround
previously put into place in the "mirror" system test to be reverted.
- there was a memory leak when using negotiated TSIG keys.
- TKEY responses could only be signed when using a newly negotiated
key; if an existent matching TSIG was found in in the keyring it
would not be used.
This adds a test for rndc dumpdb to ensure the correct "stale
comment" is printed. It also adds a test for non-stale data to
ensure no "stale comment" is printed for active RRsets.
In addition, the serve-stale tests are hardened with more accurate
grep calls.
This change makes rndc dumpdb correctly print the "; stale" line.
It also provides extra information on how long this data may still
be served to clients (in other words how long the stale RRset may
still be used).
up until now, message->tsigkey could only be set during parsing
of the request, but gss-tsig allows one to be created afterward.
this commit adds a new flag to the message structure, `new_tsigkey`,
which indicates that in this case it's okay for `dns_message_settsigkey()`
to be run on a message after parsing, without hitting any assertions due
to the lack of a TSIG in the request. this allows us to keep the current
restriction in place generally, but add an exception for TKEY processing.
it's probably better to just remove the restriction entirely (see next
commit).
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.
go back to regular resolution. When this happens the fetch timer is
already running, and we might end up in a situation where we we create
a fetch for qname-minimized query and after that the timer is triggered
and the query is retried (fctx_try) - which causes relaunching of
qname-minimization fetch - and since we already have a qmin fetch
for this fctx - assertion failure.
This fix stops the timer when doing qname minimization - qmin fetch
internal timer should take care of all the possible timeouts.
Log a message if a mirror zone becomes unusable for the resolver (most
usually due to the zone's expiration timer firing). Ensure that
verification failures do not cause a mirror zone to be unloaded
(instead, its last successfully verified version should be served if it
is available).
Log a message when a mirror zone is successfully loaded from disk and
subsequently verified.
This could have been implemented in a simpler manner, e.g. by modifying
an earlier code branch inside zone_postload() which checks whether the
zone already has a database attached and calls attachdb() if it does
not, but that would cause the resulting logs to indicate that a mirror
zone comes into effect before the "loaded serial ..." message is logged,
which would be confusing.
Tweak some existing sed commands used in the "mirror" system test to
ensure that separate test cases comprising it do not break each other.
Log a message when a mirror zone is successfully transferred and
verified, but only if no database for that zone was yet loaded at the
time the transfer was initiated.
This could have been implemented in a simpler manner, e.g. by modifying
zone_replacedb(), but (due to the calling order of the functions
involved in finalizing a zone transfer) that would cause the resulting
logs to suggest that a mirror zone comes into effect before its transfer
is finished, which would be confusing given the nature of mirror zones
and the fact that no message is logged upon successful mirror zone
verification.
Once the dns_zone_replacedb() call in axfr_finalize() is made, it
becomes impossible to determine whether the transferred zone had a
database attached before the transfer was started. Thus, that check is
instead performed when the transfer context is first created and the
result of this check is passed around in a field of the transfer context
structure. If it turns out to be desired, the relevant log message is
then emitted just before the transfer context is freed.
Taking this approach means that the log message added by this commit is
not timed precisely, i.e. mirror zone data may be used before this
message is logged. However, that can only be fixed by logging the
message inside zone_replacedb(), which causes arguably more dire issues
discussed above.
dns_zone_isloaded() is not used to double-check that transferred zone
data was correctly loaded since the 'shutdown_result' field of the zone
transfer context will not be set to ISC_R_SUCCESS unless axfr_finalize()
succeeds (and that in turn will not happen unless dns_zone_replacedb()
succeeds).
Mark AndrewsandEvan Hunt
Matthijs MekkingandMatthijs Mekking
Michał Kępień
Tinderbox User
Tony FinchandEvan Hunt
Ondřej Surý
Witold KręcickiandEvan Hunt
Petr MenšíkandMark Andrews