Use a zone's 'type' field instead of the value of its DNS_ZONEOPT_MIRROR
option for checking whether it is a mirror zone. This makes said zone
option and its associated helper function, dns_zone_mirror(), redundant,
so remove them. Remove a check specific to mirror zones from
named_zone_reusable() since another check in that function ensures that
changing a zone's type prevents it from being reused during
reconfiguration.
Rather than overloading dns_zone_slave and discerning between a slave
zone and a mirror zone using a zone option, define a separate enum
value, dns_zone_mirror, to be used exclusively by mirror zones. Update
code handling slave zones to ensure it also handles mirror zones where
applicable.
Zone loading happens in a different task (zone->loadtask) than other
zone actions (zone->task). Thus, when zone_postload() is called in the
context of zone->loadtask, it may cause zone maintenance to be queued in
zone->task and another thread can then execute zone_maintenance() before
zone_postload() gets a chance to finish its work in the first thread.
This would not be a problem if zone_maintenance() accounted for this
possibility by locking the zone before checking the state of its
DNS_ZONEFLG_LOADPENDING flag. However, the zone is currently not locked
before the state of that flag is checked, which may prevent zone
maintenance from happening despite zone_postload() scheduling it. Fix
by locking the zone in zone_maintenance() before checking the state of
the zone's DNS_ZONEFLG_LOADPENDING flag.
This properly orders clearing the freed pointer and calling isc_refcount_destroy
as early as possible to have ability to put proper memory barrier when cleaning
up reference counting.
While "rndc reload" causes dns_zone_asyncload() to be called for the
signed version of an inline-signed zone, the subsequent zone_load() call
causes the raw version to be reloaded from storage. This means that
DNS_ZONEFLG_LOADPENDING gets set for the signed version of the zone by
dns_zone_asyncload() before the reload is attempted, but zone_postload()
is only called for the raw version and thus DNS_ZONEFLG_LOADPENDING is
cleared for the raw version, but not for the signed version. This in
turn prevents zone maintenance from happening for the signed version of
the zone.
Until commit 29b7efdd9f8ce9b49371809498744c4b076dc3ee, this problem
remained dormant because DNS_ZONEFLG_LOADPENDING was previously
immediately, unconditionally cleared after zone loading was started
(whereas it should only be cleared when zone loading is finished or an
error occurs). This behavior caused other issues [1] and thus had to be
changed.
Fix reloading inline-signed zones by clearing DNS_ZONEFLG_LOADPENDING
for the signed version of the zone once the raw version reload
completes. Take care not to clear it prematurely during initial zone
load. Also make sure that DNS_ZONEFLG_LOADPENDING gets cleared when
zone_postload() encounters an error or returns early, to prevent other
scenarios from resulting in the same problem. Add comments aiming to
help explain code flow.
[1] see RT #47076
When an inline-signed zone is loaded, the master file for its signed
version is loaded and then a rollforward of the journal for the signed
version of the zone is performed. If DNS_JOURNALOPT_RESIGN is not set
during the latter phase, signatures loaded from the journal for the
signed version of the zone will not be scheduled for refresh. Fix the
conditional expression determining which flags should be used for the
dns_journal_rollforward() call so that DNS_JOURNALOPT_RESIGN is set when
zone_postload() is called for the signed version of an inline-signed
zone.
Extend bin/tests/system/stop.pl so that it can use "rndc halt" instead
of "rndc stop" as the former allows master file flushing upon shutdown
to be suppressed.
If "rndc signing -nsec3param ..." is ran for a zone which has not yet
been loaded or transferred (i.e. its "db" field is NULL), it will be
silently ignored by named despite rndc logging an "nsec3param request
queued" message, which is misleading. Prevent this by keeping a
per-zone queue of NSEC3PARAM change requests which arrive before a zone
is loaded or transferred and processing that queue once the raw version
of an inline-signed zone becomes available.
If transferring or loading a mirror zone fails, resolution should still
succeed by means of falling back to regular recursive queries.
Currently, though, if a slave zone is present in the zone table and not
loaded, a SERVFAIL response is generated. Thus, mirror zones need
special handling in this regard.
Add a new dns_zt_find() flag, DNS_ZTFIND_MIRROR, and set it every time a
domain name is looked up rather than a zone itself. Handle that flag in
dns_zt_find() in such a way that a mirror zone which is expired or not
yet loaded is ignored when looking up domain names, but still possible
to find when the caller wants to know whether the zone is configured.
This causes a fallback to recursion when mirror zone data is unavailable
without making unloaded mirror zones invisible to code checking a zone's
existence.
Update axfr_commit() so that all incoming versions of a mirror zone
transferred using AXFR are verified before being used. If zone
verification fails, discard the received version of the zone, wait until
the next refresh and retry.
Add a function for determining whether the supplied version of a mirror
zone passes DNSSEC validation and is signed using a trusted key. Define
a new libdns result signifying a zone verification failure.
Add a new slave-only boolean configuration option, "mirror", along with
its corresponding dns_zoneopt_t enum and a helper function for checking
whether that option was set for a given zone. This commit does not
introduce any behavior changes yet.
Add a new libdns function, dns_zone_logv(), which takes a single va_list
argument rather than a variable number of arguments and can be used as a
base for implementing more specific zone logging functions.
This commit reverts the previous change to use system provided
entropy, as (SYS_)getrandom is very slow on Linux because it is
a syscall.
The change introduced in this commit adds a new call isc_nonce_buf
that uses CSPRNG from cryptographic library provider to generate
secure data that can be and must be used for generating nonces.
Example usage would be DNS cookies.
The isc_random() API has been changed to use fast PRNG that is not
cryptographically secure, but runs entirely in user space. Two
contestants have been considered xoroshiro family of the functions
by Villa&Blackman and PCG by O'Neill. After a consideration the
xoshiro128starstar function has been used as uint32_t random number
provider because it is very fast and has good enough properties
for our usage pattern.
The other change introduced in the commit is the more extensive usage
of isc_random_uniform in places where the usage pattern was
isc_random() % n to prevent modulo bias. For usage patterns where
only 16 or 8 bits are needed (DNS Message ID), the isc_random()
functions has been renamed to isc_random32(), and isc_random16() and
isc_random8() functions have been introduced by &-ing the
isc_random32() output with 0xffff and 0xff. Please note that the
functions that uses stripped down bit count doesn't pass our
NIST SP 800-22 based random test.
- mark the 'geoip-use-ecs' option obsolete; warn when it is used
in named.conf
- prohibit 'ecs' ACL tags in named.conf; note that this is a fatal error
since simply ignoring the tags could make ACLs behave unpredictably
- re-simplify the radix and iptable code
- clean up dns_acl_match(), dns_aclelement_match(), dns_acl_allowed()
and dns_geoip_match() so they no longer take ecs options
- remove the ECS-specific unit and system test cases
- remove references to ECS from the ARM
The three functions has been modeled after the arc4random family of
functions, and they will always return random bytes.
The isc_random family of functions internally use these CSPRNG (if available):
1. getrandom() libc call (might be available on Linux and Solaris)
2. SYS_getrandom syscall (might be available on Linux, detected at runtime)
3. arc4random(), arc4random_buf() and arc4random_uniform() (available on BSDs and Mac OS X)
4. crypto library function:
4a. RAND_bytes in case OpenSSL
4b. pkcs_C_GenerateRandom() in case PKCS#11 library
Replace the outer for loop with a while loop to emphasize it keeps
processing the first element of diff->tuples, which changes on each
iteration due to tuples being removed from diff->tuples by
move_matching_tuples().
The ENSURE assertion at the end of dns_diff_appendminimal() is not
needed because it is placed right after code which resets *tuplep to
NULL if it is not NULL already.
The INSIST assertion in move_matching_tuples() checks the same pointer
again.
Extract the portion of the do-while loop responsible for finding the
next tuple with the same name and type into a separate function to
improve code clarity.
The do-while loop in dns__zone_updatesigs() is hard to follow due to
heavy nesting and the 'tuple' variable also being used in the outer for
loop. Add a comment to explain the purpose of the do-while loop.
Extract it into a separate function to decrease indentation and prevent
using 'tuple' in two different loops.
Rename find_zone_keys() to dns__zone_findkeys() and move it to
lib/dns/zone_p.h, so that it can be used in unit tests. Add a comment
describing the purpose of this function.
Rename update_sigs() to dns__zone_updatesigs() and move it to
lib/dns/zone_p.h, so that it can be unit tested. Add a comment
describing the purpose of this function.
Rename zonediff_t to dns__zonediff_t and move it to lib/dns/zone_p.h, so
that unit tests can be written for functions taking pointers to
structures of this type as arguments.
Add a new private header file, lib/dns/zone_p.h, which will hold type
definitions and function prototypes not meant to be exported by libdns,
but required by zone-related unit tests.
When inline signing is enabled for a zone without creating signing keys
for it, changes subsequently applied to the raw zone will not be
reflected in the secure zone due to the dns_update_signaturesinc() call
inside receive_secure_serial() failing. Given that an inline zone will
be served (without any signatures) even with no associated signing keys
being present, keep applying raw zone deltas to the secure zone until
keys become available in an attempt to follow the principle of least
astonishment.
If a raw zone is modified, but the dns_update_signaturesinc() call in
receive_secure_serial() fails, the corresponding secure zone's database
will not be modified, even though by that time a message containing the
bumped signed serial will already have been logged. This creates
confusion, because a different secure zone version will be served than
the one announced in the logs. Move the relevant dns_zone_log() call so
that it is only performed if the secure zone's database is modified.
