The current isc_time_now uses CLOCK_REALTIME_COARSE which only updates
on a timer tick. This clock is generally fine for millisecond accuracy,
but on servers with 100hz clocks, this clock is nowhere near accurate
enough for microsecond accuracy.
This commit adds a new isc_time_now_hires function that uses
CLOCK_REALTIME, which gives the current time, though it is somewhat
expensive to call. When microsecond accuracy is required, it may be
required to use extra resources for higher accuracy.
In CMocka versions << 1.1.3, the skip() function would cause the whole
unit test to abort when CMOCKA_TEST_ABORT is set. As this is problem
only in Debian 9 Stretch and Ubuntu 16.04 Xenial, we just require the
CMocka >= 1.1.3 and disable the unit testing on Debian 9 Stretch until
we can pull the libcmocka-dev from stretch-backports and remove the
Ubuntu 16.04 Xenial from the CI as it is reaching End of Standard
Support at the end of April 2021.
When NETMGR_TRACE(_VERBOSE) is enabled, the build would fail on some
non-Linux non-glibc platforms because:
* Use <stdint.h> print macros because uint_fast32_t is not always
unsigned long
* The header <execinfo.h> is not available on non-glibc, thus commit
adds dummy backtrace() and backtrace_symbols_fd() functions for
platforms without HAVE_BACKTRACE
The netmgr unit tests were designed to push the system limits to maximum
by sending as many queries as possible in the busy loop from multiple
threads. This mostly works with UDP, but in the stateful protocol where
establishing the connection takes more time, it failed quite often in
the CI. On FreeBSD, this happened more often, because the socket() call
would fail spuriosly making the problem even worse.
This commit does several things to improve reliability:
* return value of isc_nm_<proto>connect() is always checked and retried
when scheduling the connection fails
* The busy while loop has been slowed down with usleep(1000); so the
netmgr threads could schedule the work and get executed.
* The isc_thread_yield() was replaced with usleep(1000); also to allow
the other threads to do any work.
* Instead of waiting on just one variable, we wait for multiple
variables to reach the final value
* We are wrapping the netmgr operations (connects, reads, writes,
accepts) with reference counting and waiting for all the callbacks to
be accounted for.
This has two effects:
a) the isc_nm_t is always clean of active sockets and handles when
destroyed, so it will prevent the spurious INSIST(references == 1)
from isc_nm_destroy()
b) the unit test now ensures that all the callbacks are always called
when they should be called, so any stuck test means that there was
a missing callback call and it is always a real bug
These changes allows us to remove the workaround that would not run
certain tests on systems without port load-balancing.
In tls_error(), we now call isc__nm_tlsdns_failed_read() instead of just
stopping timer and reading from the socket. This allows us to properly
cleanup any pending operation on the socket.
When shutting down, calling the isc__nm_failed_connect_cb() was delayed
until the connect callback would be called. It turned out that the
connect callback might not get called at all when the socket is being
shut down. Call the failed_connect_cb() directly in the
tlsdns_shutdown() instead of waiting for the connect callback to call it.
After a partial write the tls.senddata buffer would be rearranged to
contain only the data tha wasn't sent and the len part would be made
shorter, which would lead to attempt to free only part of a socket's
tls.senddata buffer.
The tlsdns_cycle() might call uv_write() to write data to the socket,
when this happens and the socket is shutdown before the callback
completes, the uvreq structure was not freed because the callback would
be called with non-zero status code.
The RFC7828 specifies the keepalive interval to be 16-bit, specified in
units of 100 milliseconds and the configuration options tcp-*-timeouts
are following the suit. The units of 100 milliseconds are very
unintuitive and while we can't change the configuration and presentation
format, we should not follow this weird unit in the API.
This commit changes the isc_nm_(get|set)timeouts() functions to work
with milliseconds and convert the values to milliseconds before passing
them to the function, not just internally.
The udp, tcpdns and tlsdns contained lot of cut&paste code or code that
was very similar making the stack harder to maintain as any change to
one would have to be copied to the the other protocols.
In this commit, we merge the common parts into the common functions
under isc__nm_<foo> namespace and just keep the little differences based
on the socket type.
After the TCPDNS refactoring the initial and idle timers were broken and
only the tcp-initial-timeout was always applied on the whole TCP
connection.
This broke any TCP connection that took longer than tcp-initial-timeout,
most often this would affect large zone AXFRs.
This commit changes the timeout logic in this way:
* On TCP connection accept the tcp-initial-timeout is applied
and the timer is started
* When we are processing and/or sending any DNS message the timer is
stopped
* When we stop processing all DNS messages, the tcp-idle-timeout
is applied and the timer is started again
The system tests were missing a test that would test tcp-initial-timeout
and tcp-idle-timeout.
This commit adds new "timeouts" system test that adds:
* Test that waits longer than tcp-initial-timeout and then checks
whether the socket was closed
* Test that sends and receives DNS message then waits longer than
tcp-initial-timeout but shorter time than tcp-idle-timeout than
sends DNS message again than waits longer than tcp-idle-timeout
and checks whether the socket was closed
* Similar test, but bursting 25 DNS messages than waiting longer than
tcp-initial-timeout and shorter than tcp-idle-timeout than do second
25 DNS message burst
* Check whether transfer longer than tcp-initial-timeout succeeds
Add a test for freezing, manually updating, and then thawing a dynamic
zone with "dnssec-policy". In the kasp system test we add parameters
to the "update_is_signed" check to signal the indicated IP addresses
for the labels "a" and "d". If set to '-', the test is skipped.
After nsupdating the dynamic.kasp zone, we revert the update (with
nsupdate) and update the zone again, but now with the freeze/thaw
approach.
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.
This commit fixes loading the certificate chain files so that the full
chain could be sent to the clients which require that for
verification. Before that fix only the top most certificate would be
loaded from the chain and sent to clients preventing some of them to
perform certificate validation (e.g. Windows 10 DoH client).
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'.
