Sometimes it is useful to set a 'floor' on the TTL for records
to be cached. Some sites like to use ridiculously low TTLs for
some reason, and that often is not compatible with slow links.
Signed-off-by: Michael Milligan <milli@acmeps.com>
Signed-off-by: LaMont Jones <lamont@debian.org>
To minimize the effort required to set up IANA root zone mirroring,
define a default master server list for the root zone and use it when
that zone is to be mirrored and no master server list was explicitly
specified. Contents of that list are taken from RFC 7706 and are
subject to change in future releases.
Since the static get_masters_def() function in bin/named/config.c does
exactly what named_zone_configure() in bin/named/zoneconf.c needs to do,
make the former non-static and use it in the latter to prevent code
duplication.
Rather than overloading dns_zone_slave and discerning between a slave
zone and a mirror zone using a zone option, define a separate enum
value, dns_zone_mirror, to be used exclusively by mirror zones. Update
code handling slave zones to ensure it also handles mirror zones where
applicable.
- make qname-minimization option tristate {strict,relaxed,disabled}
- go straight for the record if we hit NXDOMAIN in relaxed mode
- go straight for the record after 3 labels without new delegation or 7 labels total
- use start of fetch (and not time of response) as 'now' time for querying cache for
zonecut when following delegation.
- the default setting for dnssec-validation is now "auto", which
activates DNSSEC validation using the IANA root key. The old behavior
can be restored by explicitly setting "dnssec-validation yes", which
"yes", which activates DNSSEC validation only if keys are explicitly
configured in named.conf.
- the ARM has been updated to describe the new behavior
The three functions has been modeled after the arc4random family of
functions, and they will always return random bytes.
The isc_random family of functions internally use these CSPRNG (if available):
1. getrandom() libc call (might be available on Linux and Solaris)
2. SYS_getrandom syscall (might be available on Linux, detected at runtime)
3. arc4random(), arc4random_buf() and arc4random_uniform() (available on BSDs and Mac OS X)
4. crypto library function:
4a. RAND_bytes in case OpenSSL
4b. pkcs_C_GenerateRandom() in case PKCS#11 library
4749. [func] The ISC DLV service has been shut down, and all
DLV records have been removed from dlv.isc.org.
- Removed references to ISC DLV in documentation
- Removed DLV key from bind.keys
- No longer use ISC DLV by default in delv
[RT #46155]
4724. [func] By default, BIND now uses the random number
functions provided by the crypto library (i.e.,
OpenSSL or a PKCS#11 provider) as a source of
randomness rather than /dev/random. This is
suitable for virtual machine environments
which have limited entropy pools and lack
hardware random number generators.
This can be overridden by specifying another
entropy source via the "random-device" option
in named.conf, or via the -r command line option;
however, for functions requiring full cryptographic
strength, such as DNSSEC key generation, this
cannot be overridden. In particular, the -r
command line option no longer has any effect on
dnssec-keygen.
This can be disabled by building with
"configure --disable-crypto-rand".
[RT #31459] [RT #46047]
4708. [cleanup] Legacy Windows builds (i.e. for XP and earlier)
are no longer supported. [RT #45186]
4707. [func] The lightweight resolver daemon and library (lwresd
and liblwres) have been removed. [RT #45186]
4706. [func] Code implementing name server query processing has
been moved from bin/named to a new library "libns".
Functions remaining in bin/named are now prefixed
with "named_" rather than "ns_". This will make it
easier to write unit tests for name server code, or
link name server functionality into new tools.
[RT #45186]
allows named to provide stale cached answers when
the authoritative server is under attack.
See max-stale-ttl, stale-answer-enable,
stale-answer-ttl. [RT #44790]
4664. [func] Add a "glue-cache" option to enable or disable the
glue cache. The default is "no" to reduce memory
usage, but enabling this option will improve
performance in delegation-heavy zones. [RT #45125]
4613. [func] By default, the maximum size of a zone journal file
is now twice the size of the zone's contents (there
is little benefit to a journal larger than this).
This can be overridden by setting "max-journal-size"
to "unlimited" or to an explicit value up to 2G.
Thanks to Tony Finch. [RT #38324]
4549. [func] Added support for the EDNS TCP Keepalive option
(RFC 7828). [RT #42126]
4548. [func] Added support for the EDNS Padding option (RFC 7830).
[RT #42094]
to provide feedback to the trust-anchor administrators
about how key rollovers are progressing as per
draft-ietf-dnsop-edns-key-tag-02. This can be
disabled using 'trust-anchor-telemetry no;'.
[RT #40583]
provisioning secondary servers in which a list of
zones to be served is stored in a DNS zone and can
be propagated to slaves via AXFR/IXFR. [RT #41581]
4375. [func] Add support for automatic reallocation of isc_buffer
to isc_buffer_put* functions. [RT #42394]
4371. [func] New "minimal-any" option reduces the size of UDP
responses for qtype ANY by returning a single
arbitrarily selected RRset instead of all RRsets.
Thanks to Tony Finch. [RT #41615]
