Security

There were no security issues found. All past security issues and information about how to report new ones can be found in nbdkit-security(1).

Server

The server and a subset of the plugins and filters have been ported to Windows using the Win32 API. Only the mingw-w64 toolchain is supported for building nbdkit (not MSVC). You can also cross-compile from Linux and test under Wine. Some features are missing although it is very usable.

New -D nbdkit.tls.log and -D nbdkit.tls.session debug flags which enable additional debugging for TLS sessions.

The server now responds to "NBD_INFO_NAME" (Eric Blake).

Options --run and --vsock may now be used together.

In --run, $nbd is now a synonym for $uri instead of having confusing magical properties.

Plugins

New nbdkit-S3-plugin(1) to access disks stored on AWS S3 and Ceph.

New nbdkit-sparse-random-plugin(1) which generates large disks sparsely filled with random blocks of data. These look like virtual disk images and can be used to benchmark copying tools.

nbdkit-data-plugin(1) has been greatly enhanced. New features include: "(...)[N:M]" (slice syntax), assignments, comments, variables, "<(SCRIPT)" (inlined shell script). In addition a parse tree is built, allowing optimizations and other enhancements. The plugin is now 64 bit clean allowing patterns larger than 2^32 bytes to work correctly.

nbdkit-random-plugin(1) can now be used to test copying tools.

nbdkit-vddk-plugin(1) supports enabling compression between VDDK and the VMware server which in some situations can improve performance.

Filters

New nbdkit-exportname-filter(1) can be used to extend, mask and modify the exports exposed by a plugin (Eric Blake).

New nbdkit-exitwhen-filter(1) allowing the server to gracefully exit on various events including external scripts.

New nbdkit-checkwrite-filter(1) can be used to benchmark copying tools.

nbdkit-ip-filter(1) now supports filtering clients by PID, user ID or group ID, for clients connected over a Unix domain socket. Also you can filter clients using "AF_VSOCK" and vsock port number.

nbdkit-log-filter(1) now logs "get_ready", "after_fork" and "preconnect" methods, and there is a new "logscript" feature allowing scripts to be run on logging events.

nbdkit-ext2-filter(1) new option "ext2file=exportname" can be used to allow the client to select which file to see from the filesystem using the NBD export name (Eric Blake).

Language bindings

Python style cleanups (Eric Blake).

The OCaml plugin now correctly acquires and releases the GC lock on all paths in and out.

There is a new OCaml "NBDKit.version" function returning the version of nbdkit that the plugin was compiled against.

Multiple enhancements to the Rust plugin (Alan Somers).

API

New ".list_exports", ".default_export" and ".export_description" plugin methods allowing plugins to be queried about what export names they support, and give additional descriptions of exports. New "nbdkit_use_default_export" helper function (Eric Blake).

New "nbdkit_strdup_intern", "nbdkit_strndup_intern" "nbdkit_printf_intern" and "nbdkit_vprintf_intern" functions which allow you to allocate a string in a plugin without worrying about freeing it (Eric Blake).

New "nbdkit_peer_pid", "nbdkit_peer_uid" and "nbdkit_peer_gid" allows plugins and filters to read the client’s credentials, for clients connected over a Unix domain socket.

Tests

Many tests now use libnbd(3), nbdsh(1), nbdinfo(1) and nbdcopy(1) as lighter weight replacements for qemu tools.

Fix compatibility with qemu > 5.2.0.

Build

Downstream packagers can now use this to add extra downstream information which is printed in version strings etc:
./configure --with-extra=...

If ocamldoc(1) is installed at build time, then it will be used to build the NBDKit(3) manual page for OCaml documentation.