The AES algorithm for DNS cookies was being kept for legacy reasons, and
it can be safely removed in the next major release. Remove both the AES
usage for DNS cookies and the AES implementation itself.
Commit 42d43aa075 made --with-liburcu
depend on --enable-developer. This broke pairwise testing as this new
dependency was not codified in configure.ac. Since the --with-liburcu
option is currently just a convenience for developers, there is no need
to test building against all possible RCU variants in GitLab CI until
they actually work with BIND 9. Update the pairwise testing
"configuration" in configure.ac so that builds with non-standard RCU
variants are not tested.
The Userspace-RCU variants other than membarrier is untested and at
least in QSBR case it's broken. Allow changing the Userspace-RCU
variant only in the developer's mode.
Read the Docs is capable of building the PDF version of the BIND 9 ARM
using just the contents of the doc/arm/ directory - it does not need the
build system to facilitate that. Since the BIND 9 ARM is also built in
other formats when "make doc" is run, drop the parts of the build system
that enable building the PDF version as they pull in complexity without
bringing much added value in return. Update related files accordingly.
The autoconf and named -V now prints used version of jemalloc. This
doesn't work with system supplied jemalloc, so in it prints `system`
instead in the autoconf and nothing in named -V output.
This adds support for User Statically Defined Tracing (USDT). On
Linux, this uses the header from SystemTap and dtrace utility, but the
support is universal as long as dtrace is available.
Also add the required infrastructure to add probes to libisc, libdns and
libns libraries, where most of the probes will be.
The dns_badcache unit had (yet another) own locked hashtable
implementation. Replace the hashtable used by dns_badcache with
lock-free cds_lfht implementation from liburcu.
In some cases, the inlined version rcu_dereference() would not compile
when working on pointer to opaque struct (namely Ubuntu Jammy). Detect
such condition in the autoconf and disable the inlining of the small
functions if it breaks the build.
Since we don't use networking directly but rather via libuv, these
configure options were no-op. Remove the configure checks for epoll
(Linux), kqueue (BSDs) and /dev/poll (Solaris).
Utilize developers' muscle memory to incentivize using the pytest runner
instead of the legacy one. The script also serves as basic examples of
how to run the pyest command to achieve the same results as the legacy
runner.
Invoking pytest directly should be the end goal, since it offers many
potentially useful options (refer to pytest --help).
The Userspace-RCU headers are now needed for more parts of the libisc
and libdns, thus we need to add it globally to prevent compilation
failures on systems with non-standard Userspace-RCU installation path.
Instead of having a global hashtable with a global rwlock for the GLUE
cache, move the glue_list directly into rdatasetheader and use
Userspace-RCU to update the pointer when the glue_list is empty.
Additionally, the cached glue_lists needs to be stored in the RBTDB
version for early cleaning, otherwise the circular dependencies between
nodes and glue_lists will prevent nodes to be ever cleaned up.
`UINT64_C(UINT64_MAX)' is redundant and leads to a compilation error
since UINT64_C involves token concatenation, causing the check to fail.
This change fixes that by using UINT64_MAX directly, and including the
appropriate header.
Signed-off-by: Arjun Shankar <arjun@redhat.com>
This commit allows BIND 9 to be compiled with different flavours of
Userspace RCU, and improves the integration between Userspace RCU and
our event loop:
- In the RCU QSBR, the thread is put offline when polling and online
when rcu_dereference, rcu_assign_pointer (or friends) are called.
- In other RCU modes, we check that we are not reading when reaching the
quiescent callback in the event loop.
- We register the thread before uv_work_run() callback is called and
after it has finished. The rcu_(un)register_thread() has a large
overhead, but that's fine in this case.
The spinlock is small (atomic_uint_fast32_t at most), lightweight
synchronization primitive and should only be used for short-lived and
most of the time a isc_mutex should be used.
Add a isc_spinlock unit which is either (most of the time) a think
wrapper around pthread_spin API or an efficient shim implementation of
the simple spinlock.
This is an adaptation of my `hg64` experiments for use in BIND.
As well as renaming everything according to ISC style, I have
written some more extensive tests that ensure the edge cases are
correct and the fenceposts are in the right places.
I have added utility functions for working with precision in terms of
decimal significant figures as well as this code's native binary.
for testing purposes, we need to be able to specify a library path from
which to load the dnsrps implementation. this can now be done with the
"dnsrps-library" option.
DNSRPS can now be enabled in configure regardless of whether librpz.so
is currently installed on the system.
BIND needs a collection of standard lock-free data structures,
which we can find in liburcu, along with its RCU safe memory
reclamation machinery. We will use liburcu's QSBR variant instead
of the home-grown isc_qsbr.
Completely remove the TKEY Mode 2 (Diffie-Hellman Exchanged Keying) from
BIND 9 (from named, named.conf and all the tools). The TKEY usage is
fringe at best and in all known cases, GSSAPI is being used as it should.
The draft-eastlake-dnsop-rfc2930bis-tkey specifies that:
4.2 Diffie-Hellman Exchanged Keying (Deprecated)
The use of this mode (#2) is NOT RECOMMENDED for the following two
reasons but the specification is still included in Appendix A in case
an implementation is needed for compatibility with old TKEY
implementations. See Section 4.6 on ECDH Exchanged Keying.
The mixing function used does not meet current cryptographic
standards because it uses MD5 [RFC6151].
RSA keys must be excessively long to achieve levels of security
required by current standards.
We might optionally implement Elliptic Curve Diffie-Hellman (ECDH) key
exchange mode 6 if the draft ever reaches the RFC status. Meanwhile the
insecure DH mode needs to be removed.
`libirs` used to be a reference implementation of `getaddrinfo` and
related modern resolver APIs. It was stripped down in BIND 9.18
leaving only the `irs_resconf` module, which parses
`/etc/resolv.conf`. I have kept its include path and namespace prefix,
so it remains a little fragment of libirs now embedded in libdns.
Some compilers have a built-in definition of the _FORTIFY_SOURCE macro
that differs from BIND's preferred setting. This causes errors like
the one quoted below. The solution is to undefine the macro before
defining it. A similar fix was recently committed to glibc.
<command line>: error: '_FORTIFY_SOURCE' macro redefined
#define _FORTIFY_SOURCE 2
^
<built-in>: note: previous definition is here
#define _FORTIFY_SOURCE 0
^
https://sourceware.org/git/glibc.git/commitdiff/35bcb08eaa953c9b
Unfortunately, C still lacks a standard function for pause (x86,
sparc) or yeild (arm) instructions, for use in spin lock or CAS loops.
BIND has its own based on vendor intrinsics or inline asm.
Previously, it was buried in the `isc_rwlock` implementation. This
commit renames `isc_rwlock_pause()` to `isc_pause()` and moves
it into <isc/pause.h>.
This commit also fixes the configure script so that it detects ARM
yield support on systems that identify as `aarch*` instead of `arm*`.
On 64-bit ARM systems we now use the ISB (instruction synchronization
barrier) instruction in preference to yield. The ISB instruction
pauses the CPU for longer, several nanoseconds, which is more like the
x86 pause instruction. There are more details in a Rust pull request,
which also refers to MySQL making the same change:
https://github.com/rust-lang/rust/pull/84725
