use the ISC_LIST_FOREACH pattern in places where lists had
been iterated using a different pattern from the typical
`for` loop: for example, `while (!ISC_LIST_EMPTY(...))` or
`while ((e = ISC_LIST_HEAD(...)) != NULL)`.
the pattern `for (x = ISC_LIST_HEAD(...); x != NULL; ISC_LIST_NEXT(...)`
has been changed to `ISC_LIST_FOREACH` throughout BIND, except in a few
cases where the change would be excessively complex.
in most cases this was a straightforward change. in some places,
however, the list element variable was referenced after the loop
ended, and the code was refactored to avoid this necessity.
also, because `ISC_LIST_FOREACH` uses typeof(list.head) to declare
the list elements, compilation failures can occur if the list object
has a `const` qualifier. some `const` qualifiers have been removed
from function parameters to avoid this problem, and where that was not
possible, `UNCONST` was used.
ISC_LIST_FOREACH and related macros now use 'typeof(list.head)' to
declare the list elements automatically; the caller no longer needs
to do so.
ISC_LIST_FOREACH_SAFE also now implicitly declares its own 'next'
pointer, so it only needs three parameters instead of four.
In the code base it is very common to iterate over all names in a message
section and all rdatasets for each name, but various idioms are used for
iteration.
This commit standardizes them as much as possible to a single idiom,
using the macro MSG_SECTION_FOREACH, similar to the existing
ISC_LIST_FOREACH.
the code in query_dns64() that applies the dns64 prefixes to
an A rdataset has been moved into the dns_dns64 module, and
dns_dns64_destroy() now unlinks the dns64 object from its
containing list. with these changes, we no longer need the
list-manipulation API calls dns_dns64_next() and
dns_dns64_unlink().
This is the core implementation of the SIEVE algorithm described in the
following paper:
Zhang, Yazhuo, Juncheng Yang, Yao Yue, Ymir Vigfusson, and K V
Rashmi. “SIEVE Is Simpler than LRU: An Efficient Turn-Key Eviction
Algorithm for Web Caches,” n.d.. available online from
https://junchengyang.com/publication/nsdi24-SIEVE.pdf
In QPcache, there were two places that tried to upgrade the lock. In
clean_stale_header(), the code would try to upgrade the lock and cleanup
the header, and in qpzonode_release(), the tree lock would be optionally
upgraded, so we can cleanup the node directly if empty. These
optimizations are not needed and they have no effect on the performance.
All DNSKEY keys are able to authenticate. The DNS_KEYTYPE_NOAUTH
(and DNS_KEYTYPE_NOCONF) flags were defined for the KEY rdata type,
and are not applicable to DNSKEY.
Previously, because the DNSKEY implementation was built on top of
KEY, the NOAUTH flag prevented authentication in DNSKEYs as well.
This has been corrected.
Use enums for DNS_KEYFLAG_, DNS_KEYTYPE_, DNS_KEYOWNER_, DNS_KEYALG_,
and DNS_KEYPROTO_ values.
Remove values that are never used.
Eliminate the obsolete DNS_KEYFLAG_SIGNATORYMASK. Instead, add three
more RESERVED bits for the key flag values that it covered but which
were never used.
when sending a query to a forwarder for a name within a secure domain,
the first query is now sent with CD=0. when the forwarder itself
is validating, this will give it a chance to detect bogus data and
replace it with valid data before answering. this reduces our chances
of being stuck with data that can't be validated.
if the forwarder returns SERVFAIL to the initial query, the query
will be repeated with CD=1, to allow for the possibility that the
forwarder's validator is faulty or that the bogus answer is covered
by an NTA.
note: previously, CD=1 was only sent when the query name was in a
secure domain. today, validating servers have a trust anchor at the
root by default, so virtually all queries are in a secure domain.
therefore, the code has been simplified. as long as validation is
enabled, any forward query that receives a SERVFAIL response will be
retried with CD=1.
This can be set at the option, view and server levels and causes
named to add an EDNS ZONEVERSION option to requests. Replies are
logged to the 'zoneversion' category.
when searching a DNSKEY or KEY rrset for the key that matches
a particular algorithm and ID, it's a waste of time to convert
every key into a dst_key object; it's faster to compute the key
ID by checksumming the region, and then only do the full key
conversion once we know we've found the correct key.
this optimization was already in use in the validator, but it's
been refactored for code clarity, and is now also used in query.c
and message.c.
dns_zonekey_iszonekey() was the only function defined in the
dns_zonekey module, and was only called from one place. it
makes more sense to group this with dns_dnssec functions.
Only set the next time the keymgr should run if the value is non zero.
Otherwise we default back to one hour. This may happen if there is one
or more key with an unlimited lifetime.
The keymgr never set the expected timing metadata when CDS/CDNSKEY
records for the corresponding key will be removed from the zone. This
is not troublesome, as key states dictate when this happens, but with
the new pytest we use the timing metadata to determine if the CDS and/or
CDNSKEY for the given key needs to be published.
There are a couple of cases where the safety intervals are added
inappropriately:
1. When setting the PublishCDS/SyncPublish timing metadata, we don't
need to add the publish-safety value if we are calculating the time
when the zone is completely signed for the first time. This value
is for when the DNSKEY has been published and we add a safety
interval before considering the DNSKEY omnipresent.
2. The retire-safety value should only be added to ZSK rollovers if
there is an actual rollover happening, similar to adding the sign
delay.
3. The retire-safety value should only be added to KSK rollovers if
there is an actual rollover happening. We consider the new DS
omnipresent a bit later, so that we are forced to keep the old DS
a bit longer.
While converting the kasp system test to pytest, I encountered a small
bug in the keymgr code. We retire keys when there is more than one
key matching a 'keys' line from the dnssec-policy. But if there are
multiple identical 'keys' lines, as is the case for the test zone
'checkds-doubleksk.kasp', we retire one of the two keys that have the
same properties.
Fix this by checking if there are double matches. This is not fool proof
because there may be many keys for a few identical 'keys' lines, but it
is good enough for now. In practice it makes no sense to have a policy
that dictates multiple keys with identical properties.
The fetch context that held these values could be freed while there
were still active pointers to the memory. Using a reference counted
pointer avoids this.
When a response times out the fctx_cancelquery() function
incorrectly calculates it in the 'dns_resstatscounter_queryrtt5'
counter (i.e. >=1600 ms). To avoid this, the rctx_timedout()
function should make sure that 'rctx->finish' is NULL. And in order
to adjust the RTT values for the timed out server, 'rctx->no_response'
should be true. Update the rctx_timedout() function to make those
changes.
The resquery_response() function increases the response counter without
checking if the response was successful. Increase the counter only when
the result indicates success.
There were kludges to help process responses from authoritative servers
giving RRs in wrong sections (mentioning BIND 8). These should just go
away and such responses should not be processed.
Add missing locks in dns_zone_getxfrsource4 et al. Addresses CID
468706, 468708, 468741, 468742, 468785 and 468778.
Cleanup dns_zone_setxfrsource4 et al to now return void.
Remove double copies with dns_zone_getprimaryaddr and dns_zone_getsourceaddr.
- dns_rdatatype_ismulti() returns true if a given type can have
multiple answers: ANY, RRSIG, or SIG.
- dns_rdatatype_issig() returns true for a signature: RRSIG or SIG.
- dns_rdatatype_isaddr() returns true for an address: A or AAAA.
- dns_rdatatype_isalias() returns true for an alias: CNAME or DNAME.
the step() function (used for stepping to the prececessor or
successor of a database node) could overlook a node because
there was an rdataset marked IGNORE because it had been rolled
back, covering an active rdataset under it.
when a key is revoked its key ID changes, due to the inclusion
of the "revoke" flag. a collision between this changed key ID and
that of an unrelated public-only key could cause a crash in
dnssec-signzone.
When performing QNAME minimization, named now sends an NS
query for the original QNAME, to prevent the parent zone from
receiving the QTYPE.
For example, when looking up example.com/A, we now send NS queries
for both com and example.com before sending the A query to the
servers for example.com. Previously, an A query for example.com
would have been sent to the servers for com.
Several system tests needed to be adjusted for the new query pattern:
- Some queries in the serve-stale test were sent to the wrong server.
- The synthfromdnssec test could fail due to timing issues; this
has been addressed by adding a 1-second delay.
- The cookie test could fail due to the a change in the count of
TSIG records received in the "check that missing COOKIE with a
valid TSIG signed response does not trigger TCP fallback" test case.
- The GL #4652 regression test case in the chain system test depends
on a particular query order, which no longer occurs when QNAME
minimization is active. We now disable qname-minimization
for that test.
If a timeout occurs when sending a QMIN query, QNAME
minimization should be disabled. This now causes a hard
failure in strict mode, or a fallback to non-minimized queries
in relaxed mode.
The calling fetch has already called fcount_incr() for this zone;
calling it again for a QMIN query results in double counting.
When resuming after a QMIN query is answered, however, we do now
ensure before continuing that the fetches-per-zone limit has not
been exceeded.
Extended DNS Error messages EDE 7 (expired key) and EDE 8 (validity
period of the key not yet started) are now sent in case of such DNSSEC
validation failures.
Refactor the existing validator extended error APIs in order to make it
easy to have a consisdent extra info (with domain/type) in the various
use case (i.e. when the EDE depends on validator state,
validate_extendederror or when the EDE doesn't depend of any state but
can be called directly in a specific flow).
ZONEMD needs to be able to digest SIG and RRSIG records. The signer
field can be compressed in SIG so we need to call dns_name_digest().
While for RRSIG the records the signer field is not compressed the
canonical form has the signer field downcased (RFC 4034, 6.2). This
also implies that compare_rrsig needs to downcase the signer field
during comparison.
