Ondřej Surý [Tue, 22 Jun 2021 11:08:17 +0000 (13:08 +0200)]
Use POSIX tolower(), toupper() and isupper() functions
In the code that rdataset_setownercase() and rdataset_getownercase() we
now use tolower()/toupper()/isupper() functions appropriately instead of
rolling our own code.
Ondřej Surý [Tue, 22 Jun 2021 11:05:15 +0000 (13:05 +0200)]
Don't set locale globally, just use it when needed
Previously, we would set the locale on a global level and that could
possibly lead to different behaviour in underlying functions. In this
commit, we change to code to use the system locale only when calling the
libidn2 functions and reset the locale back to "POSIX" when exiting the
libidn2 code.
Michał Kępień [Tue, 22 Jun 2021 20:45:39 +0000 (22:45 +0200)]
Improve description of mirror zone validation
Expand the description of mirror zones in the ARM by adding a brief
discussion of how the validation process works for AXFR and IXFR. Move
the paragraph mentioning the "file" option higher up. Apply minor
stylistic and whitespace-related tweaks to the relevant section of the
ARM.
Michał Kępień [Tue, 22 Jun 2021 20:26:46 +0000 (22:26 +0200)]
Tweak descriptions of buffering-related options
Apply minor stylistical and whitespace-related tweaks to the
descriptions of the "tcp-receive-buffer", "udp-receive-buffer",
"tcp-send-buffer", and "udp-send-buffer" options in the ARM.
Petr Špaček [Tue, 15 Jun 2021 08:01:59 +0000 (10:01 +0200)]
Rework description of the "max-cache-size" option
Improve the description of the "max-cache-size" option in the ARM by
focusing on its meaning for multiple views and default values.
Add mention of a hash table preallocation.
Artem Boldariev [Tue, 22 Jun 2021 10:32:24 +0000 (13:32 +0300)]
System tests to check named behaviour for unexpected opcodes
This commit adds a set of tests to verify that BIND will not crash
when some opcodes are sent over DoT or DoH, leading to marking network
handle in question as sequential.
Ondřej Surý [Tue, 22 Jun 2021 10:24:44 +0000 (12:24 +0200)]
Replace netmgr per-protocol sequential function with a common one
Previously, each protocol (TCPDNS, TLSDNS) has specified own function to
disable pipelining on the connection. An oversight would lead to
assertion failure when opcode is not query over non-TCPDNS protocol
because the isc_nm_tcpdns_sequential() function would be called over
non-TCPDNS socket. This commit removes the per-protocol functions and
refactors the code to have and use common isc_nm_sequential() function
that would either disable the pipelining on the socket or would handle
the request in per specific manner. Currently it ignores the call for
HTTP sockets and causes assertion failure for protocols where it doesn't
make sense to call the function at all.
Michał Kępień [Tue, 22 Jun 2021 13:28:31 +0000 (15:28 +0200)]
Hardcode "max-cache-size" for the "_bind" view
The built-in "_bind" view does not allow recursion and therefore does
not need a large cache database. However, as "max-cache-size" is not
explicitly set for that view in the default configuration, it inherits
that setting from global options. Set "max-cache-size" for the built-in
"_bind" view to a fixed value (2 MB, i.e. the smallest allowed value) to
prevent needlessly preallocating memory for its cache RBT hash table.
Michał Kępień [Tue, 22 Jun 2021 13:28:31 +0000 (15:28 +0200)]
Use minimal-sized caches for non-recursive views
Currently the implicit default for the "max-cache-size" option is "90%".
As this option is inherited by all configured views, using multiple
views can lead to memory exhaustion over time due to overcommitment.
The "max-cache-size 90%;" default also causes cache RBT hash tables to
be preallocated for every configured view, which does not really make
sense for views which do not allow recursion.
To limit this problem's potential for causing operational issues, use a
minimal-sized cache for views which do not allow recursion and do not
have "max-cache-size" explicitly set (either in global configuration or
in view configuration).
For configurations which include multiple views allowing recursion,
adjusting "max-cache-size" appropriately is still left to the operator.
Matthijs Mekking [Mon, 21 Jun 2021 09:36:50 +0000 (11:36 +0200)]
Fix deadlock issue with key-directory and in-view
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.
Michał Kępień [Thu, 17 Jun 2021 15:09:37 +0000 (17:09 +0200)]
Allow resetting hash table size limits for DNS DBs
When "max-cache-size" is changed to "unlimited" (or "0") for a running
named instance (using "rndc reconfig"), the hash table size limit for
each affected cache DB is not reset to the maximum possible value,
preventing those hash tables from being allowed to grow as a result of
new nodes being added.
Extend dns_rbt_adjusthashsize() to interpret "size" set to 0 as a signal
to remove any previously imposed limits on the hash table size. Adjust
API documentation for dns_db_adjusthashsize() accordingly. Move the
call to dns_db_adjusthashsize() from dns_cache_setcachesize() so that it
also happens when "size" is set to 0.
Michał Kępień [Thu, 17 Jun 2021 15:09:37 +0000 (17:09 +0200)]
Allow hash tables for cache RBTs to be grown
Upon creation, each dns_rbt_t structure has its "maxhashbits" field
initialized to the value of the RBT_HASH_MAX_BITS preprocessor macro,
i.e. 32. When the dns_rbt_adjusthashsize() function is called for the
first time for a given RBT (for cache RBTs, this happens when they are
first created, i.e. upon named startup), it lowers the value of the
"maxhashbits" field to the number of bits required to index the
requested number of hash table slots. When a larger hash table size is
subsequently requested, the value of the "maxhashbits" field should be
increased accordingly, up to RBT_HASH_MAX_BITS. However, the loop in
the rehash_bits() function currently ensures that the number of bits
necessary to index the resized hash table will not be larger than
rbt->maxhashbits instead of RBT_HASH_MAX_BITS, preventing the hash table
from being grown once the "maxhashbits" field of a given dns_rbt_t
structure is set to any value lower than RBT_HASH_MAX_BITS.
Fix by tweaking the loop guard condition in the rehash_bits() function
so that it compares the new number of bits used for indexing the hash
table against RBT_HASH_MAX_BITS rather than rbt->maxhashbits.
Michał Kępień [Thu, 17 Jun 2021 10:39:32 +0000 (12:39 +0200)]
Increase timeout in the rndc deadlock test
The timeout originally picked for "rndc status" invocations (2 seconds)
in the test attempting to reproduce a deadlock caused by running
multiple "rndc addzone", "rndc modzone", and "rndc delzone" commands
concurrently causes intermittent failures of the "addzone" system test
in GitLab CI. Increase the timeout to 10 seconds to make such failures
less probable. Adjust code comments accordingly.
Ondřej Surý [Thu, 3 Jun 2021 06:00:22 +0000 (08:00 +0200)]
Drop support for clang atomic and gcc __sync builtins
The requirements for BIND 9.17+ now requires C11 support from the
compiler, so we can safely drop most of the stdatomic.h shims from
lib/isc/unix/include/stdatomic.h.
This commit removes support for clang atomic builtins (clang >= 3.6.0
includes stdatomic.h header) and for Gcc __sync builtins.
The only compatibility shim that remains is support for __atomic
builtins for Gcc >= 4.7.0 since CentOS 7 still includes only Gcc 4.8.1
and the proper stdatomic.h header was only introduced in Gcc >= 4.9.
Artem Boldariev [Mon, 7 Jun 2021 14:46:08 +0000 (17:46 +0300)]
Set sock->iface and sock->peer properly for layered connection types
This change sets the mentioned fields properly and gets rid of klusges
added in the times when we were keeping pointers to isc_sockaddr_t
instead of copies. Among other things it helps to avoid a situation
when garbage instead of an address appears in dig output.
Artem Boldariev [Mon, 7 Jun 2021 13:38:39 +0000 (16:38 +0300)]
Make BIND refuse to serve XFRs over DoH
We cannot use DoH for zone transfers. According to RFC8484 a DoH
request contains exactly one DNS message (see Section 6: Definition of
the "application/dns-message" Media Type,
https://datatracker.ietf.org/doc/html/rfc8484#section-6). This makes
DoH unsuitable for zone transfers as often (and usually!) these need
more than one DNS message, especially for larger zones.
As zone transfers over DoH are not (yet) standardised, nor discussed
in RFC8484, the best thing we can do is to return "not implemented."
Technically DoH can be used to transfer small zones which fit in one
message, but that is not enough for the generic case.
Also, this commit makes the server-side DoH code ensure that no
multiple responses could be attempted to be sent over one HTTP/2
stream. In HTTP/2 one stream is mapped to one request/response
transaction. Now the write callback will be called with failure error
code in such a case.
Artem Boldariev [Fri, 4 Jun 2021 14:39:58 +0000 (17:39 +0300)]
Fix a crash in the client-side DoH code (header processing callback)
Support a situation in header processing callback when client side
code could receive a belated response or part of it. That could
happen when the HTTP/2 session was already closed, but there were some
response data from server in flight. Other client-side nghttp2
callbacks code already handled this case.
The bug became apparent after HTTP/2 write buffering was supported,
leading to rare unit test failures.
Artem Boldariev [Thu, 3 Jun 2021 13:12:01 +0000 (16:12 +0300)]
Nullify connect.cstream in time and keep track of all client streams
This commit ensures that sock->h2.connect.cstream gets nullified when
the object in question is deleted. This fixes a nasty crash in dig
exposed when receiving large responses leading to double free()ing.
Also, it refactors how the client-side code keeps track of client
streams (hopefully) preventing from similar errors appearing in the
future.
Michał Kępień [Thu, 10 Jun 2021 08:13:23 +0000 (10:13 +0200)]
Fix "no DS" proofs for wildcard+CNAME delegations
When answering a query requires wildcard expansion, the AUTHORITY
section of the response needs to include NSEC(3) record(s) proving that
the QNAME does not exist.
When a response to a query is an insecure delegation, the AUTHORITY
section needs to include an NSEC(3) proof that no DS record exists at
the parent side of the zone cut.
These two conditions combined trip up the NSEC part of the logic
contained in query_addds(), which expects the NS RRset to be owned by
the first name found in the AUTHORITY section of a delegation response.
This may not always be true, for example if wildcard expansion causes an
NSEC record proving QNAME nonexistence to be added to the AUTHORITY
section before the delegation is added to the response. In such a case,
named incorrectly omits the NSEC record proving nonexistence of QNAME
from the AUTHORITY section.
The same block of code is affected by another flaw: if the same NSEC
record proves nonexistence of both the QNAME and the DS record at the
parent side of the zone cut, this NSEC record will be added to the
AUTHORITY section twice.
Fix by looking for the NS RRset in the entire AUTHORITY section and
adding the NSEC record to the delegation using query_addrrset() (which
handles duplicate RRset detection).
Michał Kępień [Thu, 10 Jun 2021 08:13:23 +0000 (10:13 +0200)]
Add AUTHORITY tests for CNAME-sourced delegations
Add a set of system tests which check the contents of the AUTHORITY
section for signed, insecure delegation responses constructed from CNAME
records and wildcards, both for zones using NSEC and NSEC3.
Mark Andrews [Thu, 25 Feb 2021 03:44:44 +0000 (14:44 +1100)]
Fix the variable checked by a post-load assertion
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.
Ondřej Surý [Thu, 20 May 2021 13:53:50 +0000 (15:53 +0200)]
Completely remove BIND 9 Windows support
The Windows support has been completely removed from the source tree
and BIND 9 now no longer supports native compilation on Windows.
We might consider reviewing mingw-w64 port if contributed by external
party, but no development efforts will be put into making BIND 9 compile
and run on Windows again.
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.
Add a test case where 'named' is restarted and ensure that an already
signed zone does not change its NSEC3 parameters.
The test case first tests the current zone and saves the used salt
value. Then after restart it checks if the salt (and other parameters)
are the same as before the restart.
This test case changes 'set_nsec3param'. This will now reset the salt
value, and when checking for NSEC3PARAM we will store the salt and
use it when testing the NXDOMAIN response. This does mean that for
every test case we now have to call 'set_nsec3param' explicitly (and
can not omit it because it is the same as the previous zone).
Finally, slightly changed some echo output to make debugging friendlier.
projects / thirdparty / bind9.git / log
