This variable will report the maximum number of simultaneous tcp clients
that BIND has served while running.
It can be verified by running rndc status, then inspect "tcp high-water:
count", or by generating statistics file, rndc stats, then inspect the
line with "TCP connection high-water" text.
The tcp-highwater variable is atomically updated based on an existing
tcp-quota system handled in ns/client.c.
Related scan-build report:
dnstap_test.c:169:2: warning: Value stored to 'result' is never read
result = dns_test_makeview("test", &view);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
dnstap_test.c:193:2: warning: Value stored to 'result' is never read
result = dns_compress_init(&cctx, -1, dt_mctx);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 warnings generated.
The named_g_defaultdnstap was never used as the dnstap requires
explicit configuration of the output file.
Related scan-build report:
./server.c:3476:14: warning: Value stored to 'dpath' during its initialization is never read
const char *dpath = named_g_defaultdnstap;
^~~~~ ~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
And add a note to the man page that `rndc validation` flushes the
cache when the validation state is changed. (It is necessary to flush
the cache when turning on validation, to avoid continuing to use
cryptographically invalid data. It is probably wise to flush the cache
when turning off validation to recover from lameness problems.)
The implementation of `rndc validation status` iterates over all the
views to print their validation status. It takes care to print newlines
in between, but it also used put a nul byte at the end of the first view
which truncated the output.
After this change, the nul byte is added at the end so that it prints
the validation status in all views. The `_bind` view is skipped
because its validation status is irrelevant.
Portion of the digdelv test are skipped on IPv6 due to extra quotes
around $TESTSOCK6: "I:digdelv:IPv6 unavailable; skipping".
Researched by @michal.
Regressed with 351efd8812560c97e1bc7f6142b80ac5798d6ded.
If a TCP connection fails while attempting to send a query to a server,
the fetch context will be restarted without marking the target server as
a bad one. If this happens for a server which:
- was already marked with the DNS_FETCHOPT_EDNS512 flag,
- responds to EDNS queries with the UDP payload size set to 512 bytes,
- does not send response packets larger than 512 bytes,
and the response for the query being sent is larger than 512 byes, then
named will pointlessly alternate between sending UDP queries with EDNS
UDP payload size set to 512 bytes (which are responded to with truncated
answers) and TCP connections until the fetch context retry limit is
reached. Prevent such query loops by marking the server as bad for a
given fetch context if the advertised EDNS UDP payload size for that
server gets reduced to 512 bytes and it is impossible to reach it using
TCP.
