3938. [func] Added quotas to be used in recursive resolvers
that are under high query load for names in zones
whose authoritative servers are nonresponsive or
are experiencing a denial of service attack.
- "fetches-per-server" limits the number of
simultaneous queries that can be sent to any
single authoritative server. The configured
value is a starting point; it is automatically
adjusted downward if the server is partially or
completely non-responsive. The algorithm used to
adjust the quota can be configured via the
"fetch-quota-params" option.
- "fetches-per-zone" limits the number of
simultaneous queries that can be sent for names
within a single domain. (Note: Unlike
"fetches-per-server", this value is not
self-tuning.)
- New stats counters have been added to count
queries spilled due to these quotas.
These options are not available by default;
use "configure --enable-fetchlimit" (or
--enable-developer) to include them in the build.
See the ARM for details of these options. [RT #37125]
4006. [security] A flaw in delegation handling could be exploited
to put named into an infinite loop. This has
been addressed by placing limits on the number
of levels of recursion named will allow (default 7),
and the number of iterative queries that it will
send (default 50) before terminating a recursive
query (CVE-2014-8500).
The recursion depth limit is configured via the
"max-recursion-depth" option. [RT #35780]
acl count_acl_elements could have a short count leading
to a assertion failure. Also zero out new acl elements
in dns_acl_merge. [RT #36675]
(cherry picked from commit 3e90f6c373)
3731. [func] Added a "no-case-compress" ACL, which causes
named to use case-insensitive compression
(disabling change #3645) for specified
clients. (This is useful when dealing
with broken client implementations that
use case-sensitive name comparisons,
rejecting responses that fail to match the
capitalization of the query that was sent.)
[RT #35300]
(cherry picked from commit 166341d554)
This incorporates the following changes, plus a new configure
option "--enable-rrl" to turn them on:
3575. [func] Changed the logging category for RRL events from
'queries' to 'query-errors'. [RT #33540]
3554. [bug] RRL failed to correctly rate-limit upward
referrals and failed to count dropped error
responses in the statistics. [RT #33225]
3545. [bug] RRL slip behavior was incorrect when set to 1.
[RT #33111]
3518. [bug] Increase the size of dns_rrl_key.s.rtype by one bit
so that all dns_rrl_rtype_t enum values fit regardless
of whether it is teated as signed or unsigned by
the compiler. [RT #32792]
3494. [func] DNS RRL: Blunt the impact of DNS reflection and
amplification attacks by rate-limiting substantially-
identical responses. To enable, use "configure
--enable-rrl". [RT #28130]
