nbdkit-release-notes-1.28 - Man Page

release notes for nbdkit 1.28

Description

These are the release notes for nbdkit stable release 1.28. This describes the major changes since 1.26.

nbdkit 1.28.0 was released on 23 September 2021.

Security

CVE-2021-3716 reset structured replies on starttls

nbdkit was vulnerable to injected plaintext when upgrading to a secure connection.  For the full announcement see https://www.redhat.com/archives/libguestfs/2021-August/msg00083.html (Eric Blake).

All past security issues and information about how to report new ones can be found in nbdkit-security(1).

Plugins

nbdkit-data-plugin(1) has new le<NN>: and be<NN>: prefixes for little and big endian words.  Also the plugin tries much harder to optimize expressions.  The test suite has been greatly expanded to catch potential regressions.

nbdkit-floppy-plugin(1) now allows you to reserve free space (Nolan Leake).

nbdkit-ssh-plugin(1) no longer references SHA1 host keys as part of the effort to remove insecure algorithms (Daniel Berrangé).

nbdkit-vddk-plugin(1) reports can_flush and can_fua based on what the version of VDDK supports.  New debug flag -D vddk.stats=1 prints the amount of time spent in VDDK calls on exit which can be useful for profiling performance.

Filters

nbdkit-cow-filter(1) and nbdkit-cache-filter(1) no longer break up large read requests into page-sized requests.  In addition the default block size for both filters is now 64K.  Both changes greatly improve performance.

nbdkit-cache-filter(1) has a new cache-on-read=/PATH parameter allowing callers to enable and disable the cache-on-read feature at runtime.  Also there is a new cache-min-block-size parameter letting you select the block size at runtime (thanks Martin Kletzander).

nbdkit-cow-filter(1) has a new cow-on-read parameter which works similarly to the corresponding cache filter feature.  The new cow-block-size parameter lets you select the block size at runtime.

nbdkit-cow-filter(1) has less verbose debugging.  To restore the old debug output use -D cow.verbose=1

nbdkit-delay-filter(1) has new delay-open and delay-close parameters to inject delays when clients connect and disconnect. Delay filter parameters are now parsed more accurately (thanks Ming Xie).

Language bindings

The OCaml bindings now call caml_shutdown when unloading the plugin.  This causes Stdlib.at_exit handlers to run correctly, closes file descriptors, releases dependent shared libraries and frees memory.  Valgrind on OCaml plugins should not show any false positives about leaked memory.

OCaml and Python bindings may now use the .cleanup method.

References to Python 2 in nbdkit-python-plugin(3) have been removed.

Server

Fix captive nbdkit $uri variable so when TLS is used the URI is constructed with the nbds: prefix.  Additionally add a new variable $tls which can be used by the subprocess to tell if TLS is enabled.

Debug messages are now printed atomically.  This means that debug messages are no longer broken up across multiple lines if there are other processes writing to stderr at the same time (which often happened when using captive nbdkit).

Enhanced valgrind support (./configure --enable-valgrind) can now be enabled safely and with no performance impact even in production builds (Eric Blake).

API

Plugins or filters using nbdkit_nanosleep now don't hang if the client closes the socket abruptly (thanks Ming Xie).

Bug fixes

nbdkit-data-plugin(1) and nbdkit-memory-plugin(1) using allocator=malloc no longer crash because of memory corruption in some corner cases (only seen on s390x, but could happen on other architectures).  Meanwhile allocator=zstd no longer crashes when zeroing unallocated space.

Tests

Tests now use the new GLIBC_TUNABLES feature, replacing MALLOC_CHECK_ on glibc ≥ 2.34 (thanks Eric Blake, Siddhesh Poyarekar).

Build

configure.ac now uses spaces consistently, and has been modernized to support the latest autotools (Eric Blake).

podwrapper.pl has been unified (almost) with the copy in libnbd.

Continue fuzzing using AFL++.  Updated the fuzzing documentation.

See Also

nbdkit(1).

Authors

Authors of nbdkit 1.28:

Daniel P. Berrangé

Eric Blake

Martin Kletzander

Nolan Leake

Richard W.M. Jones

License

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Info

2021-09-23 nbdkit-1.28.0