Performing server setup checks using "+tries=3 +time=5" is redundant as
a single query is arguably good enough for determining whether a given
named instance was set up properly. Only use multiple queries with a
long timeout for resolution checks in the "legacy" system test, in order
to significantly reduce its run time (on a contemporary machine, from
about 1m45s to 0m40s).
In the "legacy" system test, in order to make server setup checks more
consistent with each other, add further checks for either presence or
absence of the EDNS OPT pseudo-RR in the responses returned by the
tested named instances.
Extract repeated dig and grep calls into two helper shell functions,
resolution_succeeds() and resolution_fails(), in order to reduce code
duplication in the "legacy" system test, emphasize the similarity
between all the resolution checks in that test, and make the conditions
for success and failure uniform for all resolution checks in that test.
When testing named instances which are configured to drop outgoing UDP
responses larger than 512 bytes, querying with DO=1 may be used instead
of querying for large TXT records as the effect achieved will be
identical: an unsigned response for a SOA query will be below 512 bytes
in size while a signed response for the same query will be over 512
bytes in size. Doing this makes all resolution checks in the "legacy"
system test more similar. Add checks for the TC flag being set in UDP
responses which are expected to be truncated to further make sure that
tested named instances behave as expected.
Sending TCP queries to test named instances with TCP support disabled
should cause dig output to contain the phrase "connection refused", not
"connection timed out", as such instances never open the relevant
sockets. Make sure that the "legacy" system test fails if the expected
phrase is not found in any of the relevant files containing dig output.
On some systems (namely Debian buster armhf) the readdir() call fails
with `Value too large for defined data type` unless the
_FILE_OFFSET_BITS=64 is defined. The correct way to fix this is to
get the appropriate compilation parameters from getconf system
interface.
Each network thread holds an array of locks, indexed by a hash
of fd. When we accept a connection we hold a lock in accepting thread.
We then generate the thread number and lock bucket for the new
connection socket - if we hit the same thread and lock bucket as
accepting socket we get a deadlock. Avoid this by checking if we're
in the same thread/lock bucket and not locking in this case.
5235. [cleanup] Refactor lib/isc/app.c to be thread-safe, unused
parts of the API has been removed and the
isc_appctx_t data type has been changed to be
fully opaque. [GL #1023]
