This test works as follow:
- Query for data.example rrset.
- Sleep until its TTL expires (2 secs).
- Disable authoritative server.
- Query for data.example again.
- Since server is down, answer come from stale cache, which has
a configured stale-answer-ttl of 3 seconds.
- Enable authoritative server.
- Query for data.example again
- Since last query before activating authoritative server failed, and
since 'stale-refresh-time' seconds hasn't elapsed yet, answer should
come from stale cache and not from the authoritative server.
Before the stale-refresh-time feature, the system test for ancient rrset
was somewhat based on the average time the previous tests and queries
were taking, thus not very precise.
After the addition of stale-refresh-time the system test for ancient
rrset started to fail since the queries for stale records (low
max-stale-ttl) were not taking the time to do a full resolution
anymore, since the answers now were coming from the cache (because the
rrset were stale and within stale-refresh-time window after the
previous resolution failure).
To handle this, the correct time to wait before rrset become ancient is
calculated from max-stale-ttl configuration plus the TTL set in the
rrset used in the tests (ans2/ans.pl).
Then before sending queries for ancient rrset, we check if we need to
sleep enough to ensure those rrset will be marked as ancient.
RFC 8767 recommends that attempts to refresh to be done no more
frequently than every 30 seconds.
Added check into named-checkconf, which will warn if values below the
default are found in configuration.
BIND will also log the warning during loading of configuration in the
same fashion.
Before this update, BIND would attempt to do a full recursive resolution
process for each query received if the requested rrset had its ttl
expired. If the resolution fails for any reason, only then BIND would
check for stale rrset in cache (if 'stale-cache-enable' and
'stale-answer-enable' is on).
The problem with this approach is that if an authoritative server is
unreachable or is failing to respond, it is very unlikely that the
problem will be fixed in the next seconds.
A better approach to improve performance in those cases, is to mark the
moment in which a resolution failed, and if new queries arrive for that
same rrset, try to respond directly from the stale cache, and do that
for a window of time configured via 'stale-refresh-time'.
Only when this interval expires we then try to do a normal refresh of
the rrset.
The logic behind this commit is as following:
- In query.c / query_gotanswer(), if the test of 'result' variable falls
to the default case, an error is assumed to have happened, and a call
to 'query_usestale()' is made to check if serving of stale rrset is
enabled in configuration.
- If serving of stale answers is enabled, a flag will be turned on in
the query context to look for stale records:
query.c:6839
qctx->client->query.dboptions |= DNS_DBFIND_STALEOK;
- A call to query_lookup() will be made again, inside it a call to
'dns_db_findext()' is made, which in turn will invoke rbdb.c /
cache_find().
- In rbtdb.c / cache_find() the important bits of this change is the
call to 'check_stale_header()', which is a function that yields true
if we should skip the stale entry, or false if we should consider it.
- In check_stale_header() we now check if the DNS_DBFIND_STALEOK option
is set, if that is the case we know that this new search for stale
records was made due to a failure in a normal resolution, so we keep
track of the time in which the failured occured in rbtdb.c:4559:
header->last_refresh_fail_ts = search->now;
- In check_stale_header(), if DNS_DBFIND_STALEOK is not set, then we
know this is a normal lookup, if the record is stale and the query
time is between last failure time + stale-refresh-time window, then
we return false so cache_find() knows it can consider this stale
rrset entry to return as a response.
The last additions are two new methods to the database interface:
- setservestale_refresh
- getservestale_refresh
Those were added so rbtdb can be aware of the value set in configuration
option, since in that level we have no access to the view object.
The SOA lookup for edns512 could succeed if the negative response
for ns.edns512/AAAA completed before all the edns512/SOA query
attempts are made. The ns.edns512/AAAA lookup returns tc=1 and
the SOA record is cached after processing the NODATA response.
Lookup a TXT record at edns512 and look it up instead of the
SOA record.
Removed 'checking that TCP failures do not influence EDNS statistics
in the ADB' as it is no longer appropriate.
This commit extends the perl Configure script to also check for libssl
in addition to libcrypto and change the vcxproj source files to link
with both libcrypto and libssl.
one of the tests in the resolver system test depends on dig
getting no response to its first two query attempts, and SERVFAIL
on the third after resolution times out.
using a 5-second retry timer in dig means the SERVFAIL response
could occur while dig is discarding the second query and preparing
to send the third. in this case the server's response could be
missed. shortening the retry interval to 4 seconds ensures that
dig has already sent the third query when the SERVFAIL response
arrives.
also, the serve-stale system test could fail due to a race in which
it timed out after waiting ten seconds for a file to be written, and
the dig timeout was just a bit longer. this is addressed by extending
the dig timeout to 11 seconds for this test.
The network manager does not support returning UDP datagrams to
clients from unexpected sources; it is therefore not possible for
dig to accept them. The "+[no]unexpected" option has therefore
been removed from the dig command and its documentation.
In order for a "fast-expire/IN: response-policy zone expired" message to
be logged in ns3/named.run, the "fast-expire" zone must first be
transferred in by that server. However, with unfavorable timing, ns3
may be stopped before it manages to fetch the "fast-expire" zone from
ns5 and after the latter has been reconfigured to no longer serve that
zone. In such a case, the "rpz" system test will report a false
positive for the relevant check. Prevent that from happening by
ensuring ns3 manages to transfer the "fast-expire" zone before getting
shut down.
Some setup scripts uses DEFAULT_ALGORITHM in their dnssec-policy
and/or initial signing. The tests still used the literal values
13, ECDSAP256SHA256, and 256. Replace those occurrences where
appropriate.
ans10 simulates a local anycast server which has both signed and
unsigned instances of a zone. 'A' queries get answered from the
signed instance. Everything else gets answered from the unsigned
instance. The resulting answer should be insecure.
"tcp-only" was not being tested correctly in the RPZ system test
because the option to the "digcmd" function that causes queries to
be sent via TCP was misspelled in one case, and was being interpreted
as a query name.
the "ckresult" function has also been changed to be case sensitive
for consistency with "digcmd".
While libltdl is a feature-rich library, BIND 9 code only uses its basic
capabilities, which are also provided by libuv and which BIND 9 already
uses for other purposes. As libuv's cross-platform shared library
handling interface is modeled after the POSIX dlopen() interface,
converting code using the latter to the former is simple. Replace
libltdl function calls with their libuv counterparts, refactoring the
code as necessary. Remove all use of libltdl from the BIND 9 source
tree.
The double equal sign ('==') is a Bash-specific string comparison
operator. Ensure the single equal sign ('=') is used in all POSIX shell
scripts in the system test suite in order to retain their portability.
On Linux core dump contains absolute path to crashed binary
Core was generated by `/home/newman/isc/ws/bind9/bin/named/.libs/lt-named -D glue-ns1 -X named.lock -m'.
However, on OpenBSD there's only a basename
Core was generated by `named'.
This commit adds support for the latter, retains the former.
Some non-POSIX shells, like /bin/csh on FreeBSD, are unable to execute
the config.guess file:
+ /bin/csh /var/tmp/gitlab_runner/builds/YdCaoq4b/0/mnowak/bind9/config.guess
timestamp=2018-02-24: Command not found.
me=config.guess: Command not found.
Unmatched '"'.
When ./configure is run, it attempts to locate a POSIX-compliant shell.
Use the result of that search in the bin/tests/system/ifconfig.sh
script.
This test is very simple, two nameserver instances are created:
- ns4: master, with 'minimal-responses yes', authoritative
for example. zone
- ns5: slave, stub zone
The first thing verified is the transfer of zone data from master
to slave, which should be saved in ns5/example.db.
After that, a query is issued to ns5 asking for target.example.
TXT, a record present in the master database with the "test" string
as content.
If that query works, it means stub zone successfully request
nameserver addresses from master, ns4.example. A/AAAA
The presence of both A/AAAA records for ns4 is also verified in the
stub zone local file, ns5/example.db.
This commit ensures that dnstap output files captured
by fstrm_capture are properly flushed before any attempt
on reading them with dnstap-read is done.
By reading fstrm-capture source code it was noticed that
signal SIGHUP is used to flush the capture file.
When networking statistics was added to the netmgr (in commit
5234a8e00a), two lines were added that
increment the 'STATID_RECVFAIL' statistic: One if 'uv_read_start'
fails and one at the end of the 'read_cb'. The latter happens
if 'nread < 0'.
According to the libuv documentation, I/O read callbacks (such as for
files and sockets) are passed a parameter 'nread'. If 'nread' is less
than 0, there was an error and 'UV_EOF' is the end of file error, which
you may want to handle differently.
In other words, we should not treat EOF as a RECVFAIL error.
Add a +burst option to mdig so that we have a second to setup the
mdig calls then they run at the start of the next second.
RRL uses 'queries in a second' as a approximation to
'queries per second'. Getting the bursts of traffic to all happen in
the same second should prevent false negatives in the system test.
We now have a second to setup the traffic in. Then the traffic should
be sent at the start of the next second. If that still fails we
should move to +burst=<now+2> (further extend mdig) instead of the
implicit <now+1> as the trigger second.
* the legacy test with -T maxudp512 will just fail, e.g. if the packets
larger than 512 octets are dropped along the path, the proper response
is to fail
* digdelv test was just expecting default server EDNS buffer size to be
4096, the test needed only slight adjustment
While working on 'rndc dnssec -rollover' I noticed the following
(small) issues:
- The key files where updated with hints set to "-when" and that
should always be "now.
- The kasp system test did not properly update the test number when
calling 'rndc dnssec -checkds' (and ensuring that works).
- There was a missing ']' in the rndc.c help output.
This command is similar in arguments as -checkds so refactor the
'named_server_dnssec' function accordingly. The only difference
are that:
- It does not take a "publish" or "withdrawn" argument.
- It requires the key id to be set (add a check to make sure).
Add tests that will trigger rollover immediately and one that
schedules a test in the future.
Sometimes, not all keys have been created in time before 'check_keys'
is called. Run a 'retry_quiet' on checking the number of keys before
continuing checking the key data.
Use the testcrypto script to see if these algorithms are supported by
openssl. If so, add the specific configuration to the named.conf file
and touch a file to indicate support. If the file exists, the
corresponding setup and tests are performed.
Make sure "order none" RRset ordering rules are tested in the
"rrsetorder" system test just like all other rule types are. As the
check for the case of no "rrset-order" rule matching a given RRset also
tests "order none" (rather than "order random", as the test code may
suggest at first glance), replace the test code for that case so that it
matches other "order none" tests.
The dns_message_create() function cannot soft fail (as all memory
allocations either succeed or cause abort), so we change the function to
return void and cleanup the calls.
