freebsd

Crystal bindings for FreeBSD system libraries — opt-in by sub-library.

Each sub-library is a separate require. require "freebsd" alone pulls in nothing but the FreeBSD::VERSION constant — no C libraries are linked until you explicitly require the sub-library you need:

require "freebsd/pkg"       # libpkg — package management
require "freebsd/capsicum"  # Capsicum — capability mode sandboxing
require "freebsd/casper"    # libcasper — privilege-separated services
require "freebsd/nvlist"    # libnv — named-value lists
require "freebsd/privdrop"  # setuid/setgid/chroot helpers
require "freebsd/audit"     # libbsm — BSM audit event writer

Mix and match only what your application needs.

• freebsd/pkg — libpkg package management. Query installed packages, search repository catalogs, install/remove/upgrade packages via the jobs API, manage annotations and locks, register event callbacks for progress reporting.

• freebsd/capsicum — Capsicum kernel capability mode (cap_enter, fd rights, pdfork process descriptors). Use this alone when you only need sandboxing without the libcasper service framework.

• freebsd/casper — libcasper services built on top of freebsd/capsicum: DNS, file, net, syslog, pwd/grp/sysctl, and a pure-Crystal audit helper for capsicum-safe BSM writes. Lets a sandboxed process delegate privileged work to a trusted helper. Includes transparent integrations for Crystal's stdlib (Socket::Addrinfo, File, Log).

• freebsd/nvlist — libnv encoder/decoder. Named-value lists used internally by libcasper and the FreeBSD kernel for structured data exchange.

• freebsd/privdrop — privilege-drop helpers (setuid, setgid, setgroups, initgroups, chroot) with correct-ordering documentation and environment scrubbing. Use before entering capability mode to relinquish root cleanly.

• freebsd/audit — libbsm / OpenBSM audit event writer. Lets Crystal applications emit structured BSM audit records to FreeBSD's audit subsystem. Event types are mapped directly from OCSF class UIDs (bsm = ocsf_uid + 40000), with per-class activity enums and a write_activity API that resolves the event class automatically from the activity value.

Platform: FreeBSD primary, DragonFlyBSD best-effort. On other platforms the shard compiles cleanly but any call raises UnsupportedPlatformError.

Versioning

Versions follow <freebsd_major>.<minor>.<update> — the first number tracks the FreeBSD major release the bindings target (e.g. 15.x.x for FreeBSD 15), the second is a feature increment, and the third is this shard's own update counter (bug fixes, lint/tooling changes, etc.), not a FreeBSD point-release number. The initial release for a given FreeBSD major version starts at <major>.0.0 (e.g. 15.0.0 = first release targeting FreeBSD 15.0-RELEASE).

Installation

Add to shard.yml:

dependencies:
  freebsd:
    github: threez/freebsd.cr

then shards install.

Sub-libraries

See each sub-library's README for full API documentation and examples:

• freebsd/pkg
• freebsd/capsicum
• freebsd/casper
• freebsd/nvlist
• freebsd/privdrop
• freebsd/audit

Development

shards install
crystal spec

On non-FreeBSD hosts most specs are marked pending. To exercise the real bindings, run the suite on a FreeBSD 14/15 host or VM (FreeBSD 15 is used in development; FreeBSD 14 is also supported).

Contributing

1. Fork it (https://github.com/threez/freebsd.cr/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Open a Pull Request

Contributors

• Vincent Landgraf — creator and maintainer