Migrate all sandbox and VM driver network policy enforcement from
iptables to nftables. nftables provides atomic ruleset loading, a
cleaner rule syntax, and is the standard netfilter interface in modern
kernels.
Sandbox bypass enforcement (openshell-sandbox):
- Replace iptables chain of individual rule insertions with a single
atomic nftables ruleset load via nft -f
- New nft_ruleset module with pure functions for ruleset generation
and unit tests
- Combine log and reject rules in one inet family table (handles both
IPv4 and IPv6 in a single ruleset)
- Fall back to reject-only ruleset when kernel lacks nft_log support
- Enable net.netfilter.nf_log_all_netns so log rules work from
non-init network namespaces
- Use temp file for nft ruleset loading instead of stdin for
compatibility with minimal VM guest environments
VM TAP networking (openshell-driver-vm):
- Replace iptables NAT/forwarding rules with nftables equivalents
- New nft_ruleset module for TAP network rule generation with unit
tests
- Atomic table-per-TAP-device lifecycle (create/destroy)
- Host-side rules provide NAT infrastructure and defense-in-depth
isolation (input chain restricts VM to gateway port only, forward
chain blocks unsolicited inbound); primary security enforcement
happens inside the VM guest via the sandbox supervisor's own rules
VM init script:
- Load nft kernel modules at sandbox init
- Enable nf_log_all_netns sysctl for bypass detection logging
OCSF / docs:
- Update firewall rule engine references from iptables to nftables
- Document host firewall interaction model and two-layer enforcement
architecture in VM driver README and compute drivers reference
Closes#1335
Signed-off-by: Russell Bryant <rbryant@redhat.com>
On Linux non-root hosts, virtiofs maps guest root to the host user,
so chown inside the VM is denied. This causes the init script to
abort under set -e, preventing the sandbox from starting.
Make the chown best-effort: if it fails, log a warning and continue.
The supervisor's own filesystem preparation handles ownership for the
paths that matter, so the sandbox works correctly without it.
This is a pragmatic workaround — anything that would break due to
the failed chown will still break, just later and with a clearer
error rather than a cryptic boot failure. In practice the sandbox
functions normally because the supervisor sets up its own working
directories.
Signed-off-by: Russell Bryant <russell.bryant@gmail.com>
When the VM driver extracts OCI image layers on a non-root host (e.g.
macOS UID 501), fs::copy and tar::unpack create files owned by the host
user. The sandbox user inside the VM then cannot write to its own home
directory.
Add a conditional chown in the VM init script that detects the mismatch
and fixes ownership before the supervisor starts. The check is skipped
when ownership is already correct (e.g. Linux-as-root extraction).
Signed-off-by: Florent Benoit <fbenoit@redhat.com>
* Adding qemu vm driver support with GPU pass-through
Signed-off-by: Vincent Caux-Brisebois <vcauxbrisebo@nvidia.com>
* Add GPU rootfs variant, harden VFIO binding, and fix networking and supervisor reliability issues discovered during GPU VM bring-up.
Signed-off-by: Vincent Caux-Brisebois <vcauxbrisebo@nvidia.com>
---------
Signed-off-by: Vincent Caux-Brisebois <vcauxbrisebo@nvidia.com>
bornav