If we have a CDS or CDNSKEY we at least need to have a DNSKEY with the
same algorithm published and signing the CDS RRset. Same for CDNSKEY
of course.
This relaxes the zone_cdscheck function, because before the CDS or
CDNSKEY had to match a DNSKEY, now only the algorithm has to match.
This allows a provider in a multisigner model to update the CDS/CDNSKEY
RRset in the zone that is served by the other provider.
The old approach where each zone structure has its own mutex that
a thread needs to obtain multiple locks to do safe keyfile I/O
operations lead to a race condition ending in a possible deadlock.
Consider a zone in two views. Each such zone is stored in a separate
zone structure. A thread that needs to read or write the key files for
this zone needs to obtain both mutexes in seperate structures. If
another thread is working on the same zone in a different view, they
race to get the locks. It would be possible that thread1 grabs the
lock of the zone in view1, while thread2 wins the race for the lock
of the zone in view2. Now both threads try to get the other lock, both
of them are already locked.
Ideally, when a thread wants to do key file operations, it only needs
to lock a single mutex. This commit introduces a key management hash
table, stored in the zonemgr structure. Each time a zone is being
managed, an object is added to the hash table (and removed when the
zone is being released). This object is identified by the zone name
and contains a mutex that needs to be locked prior to reading or
writing key files.
(cherry-picked from commit ef4619366d49efd46f9fae5f75c4a67c246ba2e6)
Similar to notify, add code to send and keep track of checkds requests.
On every zone_rekey event, we will check the DS at parental agents
(but we will only actually query parental agents if theree is a DS
scheduled to be published/withdrawn).
On a zone_rekey event, we will first clear the ongoing checkds requests.
Reset the counter, to avoid continuing KSK rollover premature.
This has the risk that if zone_rekey events happen too soon after each
other, there are redundant DS queries to the parental agents. But
if TTLs and the configured durations in the dnssec-policy are sane (as
in not ridiculous short) the chance of this happening is low.
This code gathers DNSSEC keys from key files and from the DNSKEY RRset.
It is used for the 'rndc dnssec -status' command, but will also be
needed for "checkds". Turn it into a function.
When performing the 'setnsec3param' task, zones that are not loaded will have
their task rescheduled. We should do this only if the zone load is still
pending, this prevents zones that failed to load get stuck in a busy wait and
causing a hang on shutdown.
When locking key files for a zone, we iterate over all the views and
lock a mutex inside the zone structure. However, if we envounter an
in-view zone, we will try to lock the key files twice, one time for
the home view and one time for the in-view view. This will lead to
a deadlock because one thread is trying to get the same lock twice.
Instead of checking the value of the variable modified two lines earlier
(the number of SOA records present at the apex of the old version of the
zone), one of the RUNTIME_CHECK() assertions in zone_postload() checks
the number of SOA records present at the apex of the new version of the
zone, which is already checked before. Fix the assertion by making it
check the correct variable.
When named restarts, it will examine signed zones and checks if the
current denial of existence strategy matches the dnssec-policy. If not,
it will schedule to create a new NSEC(3) chain.
However, on startup the zone database may not be read yet, fooling
BIND that the denial of existence chain needs to be created. This
results in a replacement of the previous NSEC(3) chain.
Change the code such that if the NSEC3PARAM lookup failed (the result
did not return in ISC_R_SUCCESS or ISC_R_NOTFOUND), we will try
again later. The nsec3param structure has additional variables to
signal if the lookup is postponed. We also need to save the signal
if an explicit resalt was requested.
In addition to the two added boolean variables, we add a variable to
store the NSEC3PARAM rdata. This may have a yet to be determined salt
value. We can't create the private data yet because there may be a
mismatch in salt length and the NULL salt value.
Previously, dumping the zones to the files were quantized, so it doesn't
slow down network IO processing. With the introduction of network
manager asynchronous threadpools, we can move the IO intensive work to
use that API and we don't have to quantize the work anymore as it the
file IO won't block anything except other zone dumping processes.
configuring with --enable-mutex-atomics flagged these incorrectly
initialised variables on systems where pthread_mutex_init doesn't
just zero out the structure.
Previously, as a way of reducing the contention between threads a
clientmgr object would be created for each interface/IP address.
We tasks being more strictly bound to netmgr workers, this is no longer
needed and we can just create clientmgr object per worker queue (ncpus).
Each clientmgr object than would have a single task and single memory
context.
dns_message_gettempname() now returns a pointer to an initialized
name associated with a dns_fixedname_t object. it is no longer
necessary to allocate a buffer for temporary names associated with
the message object.
This function has never been used since it was added to the source tree
by commit 686b27bfd3 back in 1999. As
the dns_zoneflg_t type is only defined in lib/dns/zone.c, no function
external to that file would be able to use dns_zone_setflag() properly
anyway - the DNS_ZONE_SETFLAG() and DNS_ZONE_CLRFLAG() macros should be
used instead. Zone options that can be set from outside zone.c are set
using dns_zone_setoption().
all zone loading tasks have the privileged flag, but we only want
them to run as privileged tasks when the server is being initialized;
if we privilege them the rest of the time, the server may hang for a
long time after a reload/reconfig. so now we call isc_taskmgr_setmode()
to turn privileged execution mode on or off in the task manager.
isc_task_privileged() returns true if the task's privilege flag is
set *and* the taskmgr is in privileged execution mode. this is used
to determine in which netmgr event queue the task should be run.
When we introduced "dnssec-policy insecure" we could have removed the
'strcmp' check for "none", because if it was set to "none", the 'kasp'
variable would have been set to NULL.
BIND 9 is smart about when to sign with what key. If a key is offline,
BIND will delete the old signature anyway if there is another key to
sign the RRset with.
With KASP we don't want to fallback to the KSK if the ZSK is missing,
only for the SOA RRset. If the KSK is missing, but we do have a ZSK,
deleting the signature is fine. Otherwise it depends on if we use KASP
or not. Update the 'delsig_ok' function to reflect that.
When checking the current DNSSEC state against the policy, consider
offline keys. If we didn't found an active key, check if the key is
offline by checking the public key list. If there is a match in the
public key list (the key data is retrieved from the .key and the
.state files), treat the key as offline and don't create a successor
key for it.
Add a new built-in policy "insecure", to be used to gracefully unsign
a zone. Previously you could just remove the 'dnssec-policy'
configuration from your zone statement, or remove it.
The built-in policy "none" (or not configured) now actually means
no DNSSEC maintenance for the corresponding zone. So if you
immediately reconfigure your zone from whatever policy to "none",
your zone will temporarily be seen as bogus by validating resolvers.
This means we can remove the functions 'dns_zone_use_kasp()' and
'dns_zone_secure_to_insecure()' again. We also no longer have to
check for the existence of key state files to figure out if a zone
is transitioning to insecure.
If a zone transfer results in a zone not having any NS records, named
stops serving it because such a zone is broken. Do the same if an
incoming zone transfer results in a zone lacking an SOA record at the
apex or containing more than one SOA record.
If there happens to be a RRSIG(SOA) that is not at the zone apex
for any reason it should not be considered as a stopping condition
for incremental zone signing.
This commit changes the taskmgr to run the individual tasks on the
netmgr internal workers. While an effort has been put into keeping the
taskmgr interface intact, couple of changes have been made:
* The taskmgr has no concept of universal privileged mode - rather the
tasks are either privileged or unprivileged (normal). The privileged
tasks are run as a first thing when the netmgr is unpaused. There
are now four different queues in in the netmgr:
1. priority queue - netievent on the priority queue are run even when
the taskmgr enter exclusive mode and netmgr is paused. This is
needed to properly start listening on the interfaces, free
resources and resume.
2. privileged task queue - only privileged tasks are queued here and
this is the first queue that gets processed when network manager
is unpaused using isc_nm_resume(). All netmgr workers need to
clean the privileged task queue before they all proceed normal
operation. Both task queues are processed when the workers are
finished.
3. task queue - only (traditional) task are scheduled here and this
queue along with privileged task queues are process when the
netmgr workers are finishing. This is needed to process the task
shutdown events.
4. normal queue - this is the queue with netmgr events, e.g. reading,
sending, callbacks and pretty much everything is processed here.
* The isc_taskmgr_create() now requires initialized netmgr (isc_nm_t)
object.
* The isc_nm_destroy() function now waits for indefinite time, but it
will print out the active objects when in tracing mode
(-DNETMGR_TRACE=1 and -DNETMGR_TRACE_VERBOSE=1), the netmgr has been
made a little bit more asynchronous and it might take longer time to
shutdown all the active networking connections.
* Previously, the isc_nm_stoplistening() was a synchronous operation.
This has been changed and the isc_nm_stoplistening() just schedules
the child sockets to stop listening and exits. This was needed to
prevent a deadlock as the the (traditional) tasks are now executed on
the netmgr threads.
* The socket selection logic in isc__nm_udp_send() was flawed, but
fortunatelly, it was broken, so we never hit the problem where we
created uvreq_t on a socket from nmhandle_t, but then a different
socket could be picked up and then we were trying to run the send
callback on a socket that had different threadid than currently
running.
When setnsec3param() is schedule from zone_postload() there's no
guarantee that `zone->db` is not `NULL` yet. Thus when the
setnsec3param() is called, we need to check for `zone->db` existence and
reschedule the task, because calling `rss_post()` on a zone with empty
`.db` ends up with no-op (the function just returns).
Too much logic was cramped inside the dns_journal_rollforward() that
made it harder to follow. The dns_journal_rollforward() was refactored
to work over already opened journal and some of the previous logic was
moved to new static zone_journal_rollforward() that separates the
journal "rollforward" logic from the "zone" logic.
when dns_journal_rollforward returned ISC_R_RECOVERABLE the distintion
between 'up to date' and 'success' was lost, as a consequence
zone_needdump() was called writing out the zone file when it shouldn't
have been. This change restores that distintion. Adjust system
test to reflect visible changes.
The draft says that the NSEC(3) TTL must have the same TTL value
as the minimum of the SOA MINIMUM field and the SOA TTL. This was
always the intended behaviour.
Update the zone structure to also track the SOA TTL. Whenever we
use the MINIMUM value to determine the NSEC(3) TTL, use the minimum
of MINIMUM and SOA TTL instead.
There is no specific test for this, however two tests need adjusting
because otherwise they failed: They were testing for NSEC3 records
including the TTL. Update these checks to use 600 (the SOA TTL),
rather than 3600 (the SOA MINIMUM).
Fix race between zone_maintenance and dns_zone_notifyreceive functions,
zone_maintenance was attempting to read a zone flag calling
DNS_ZONE_FLAG(zone, flag) while dns_zone_notifyreceive was updating
a flag in the same zone calling DNS_ZONE_SETFLAG(zone, ...).
The code reading the flag in zone_maintenance was not protected by the
zone's lock, to avoid a race the zone's lock is now being acquired
before an attempt to read the zone flag is made.
CDS/CDNSKEY DELETE records are only useful if they are signed,
otherwise the parent cannot verify these RRsets anyway. So once the DS
has been removed (and signaled to BIND), we can remove the DNSKEY and
RRSIG records, and at this point we can also remove the CDS/CDNSKEY
records.
Dynamic zones with dnssec-policy could not be thawed because KASP
zones were considered always dynamic. But a dynamic KASP zone should
also check whether updates are disabled.
The transport should also be detached when we skip a master, otherwise
named will crash when sending a SOA query to the next master over TLS,
because the transport must be NULL when we enter
'dns_view_gettransport'.
- use a value less than 2^32 for DNS_ZONEFLG_FIXJOURNAL; a larger value
could cause problems in some build environments. the zone flag
DNS_ZONEFLG_DIFFONRELOAD, which was no longer in use, has now been
deleted and its value reused for _FIXJOURNAL.
when the 'max-ixfr-ratio' option was added, journal transaction
headers were revised to include a count of RR's in each transaction.
this made it impossible to read old journal files after an upgrade.
this branch restores the ability to read version 1 transaction
headers. when rolling forward, printing journal contents, if
the wrong transaction header format is found, we can switch.
when dns_journal_rollforward() detects a version 1 transaction
header, it returns DNS_R_RECOVERABLE. this triggers zone_postload()
to force a rewrite of the journal file in the new format, and
also to schedule a dump of the zone database with minimal delay.
journal repair is done by dns_journal_compact(), which rewrites
the entire journal, ignoring 'max-journal-size'. journal size is
corrected later.
newly created journal files now have "BIND LOG V9.2" in their headers
instead of "BIND LOG V9". files with the new version string cannot be
read using the old transaction header format. note that this means
newly created journal files will be rejected by older versions of named.
named-journalprint now takes a "-x" option, causing it to print
transaction header information before each delta, including its
format version.
When applying dnssec-policy on a dynamic zone (e.g. that allows Dynamic
Updates), the NSEC3 parameters were put on the queue, but they were
not being processed (until a reload of the zone or reconfiguration).
Process the NSEC3PARAM queue on zone postload when handling a
dynamic zone.
