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mars-nwe/doc/NSS_USERSPACE_ADAPTATION.md
2026-06-14 11:49:38 +02:00

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# NSS userspace adaptation boundary
The NSS import is a source and behaviour reference for Mars NWE. The goal is
not to recreate the Novell NSS filesystem or its Linux kernel modules in
userspace. The goal is to reuse the useful NSS semantics as libraries that Mars
NWE can call.
## Target semantics
The useful exported behaviour is primarily:
- namespace handling for DOS, LONG/OS2 and later MAC/UNIX/DataStream/EA;
- trustee and rights-management semantics;
- effective-rights calculation;
- extended-attribute and metadata semantics;
- the `_ADMIN`/AdminVolume view as a Mars-provided in-memory/config-backed
userspace volume;
- salvage/compression/repair-related helpers where they expose useful NetWare
semantics.
These pieces should become library code owned by Mars NWE integration points,
not a standalone NSS volume implementation.
## Storage and persistence boundary
NSS code may contain logic for writing metadata, names, trustees or xattrs into
an NSS volume. In Mars NWE, that storage backend is different:
- metadata and xattrs should be mapped to the underlying host filesystem, using
the existing or future Mars/NWFS xattr layer;
- AdminVolume data should be generated from Mars configuration/runtime state,
not stored in a fake NSS disk format;
- namespace and rights functions should operate on Mars volume/file abstractions
once the dependency chain is available;
- no Linux kernel module, NSS disk format or hidden NSS volume should become a
runtime requirement.
During initial imports, keep NSS files as close to original as practical so the
real dependencies are visible. Later integration patches may replace NSS storage
hooks with Mars userspace hooks, but those replacements should be explicit and
well documented.
## Makefile and module-list audit
The NSS `Makefile`, `*Modules.mk` and buildtool files are useful as dependency
maps. They should be used to identify which sources belong to features such as
AdminVolume, namespace, common Beast objects, LSA, cache/runtime support and
rights handling.
They are not a build target for Mars NWE. Mars should import only the source
files and headers required to expose the desired library behaviour, then wire
those pieces into the CMake library targets.
## Import strategy
1. Import bottom-up runtime dependencies with original filenames and directory
shape where practical.
2. Prefer real NSS implementation files over invented wrappers.
3. Keep public include roots as `include/core` and `include/nwfs`; keep NSS
subdirectories in include names.
4. Add small CTests for each imported runtime group.
5. When NSS code reaches filesystem persistence, replace that boundary with Mars
userspace adapters instead of carrying NSS kernel/disk assumptions forward.
6. Audit already-imported or rewritten Mars files, especially `nwfs/lsa`, before
building higher-level namespace/AdminVolume features on top of them.
## AdminVolume direction
`_ADMIN` should be represented as a Mars NWE userspace/admin library view. The
NSS sources should provide the semantics and object layout clues, while Mars
provides the backing data. The initial integration should keep `_ADMIN` internal
and not expose it over NCP until namespace, metadata, rights and generated-file
behaviour are reliable.
Volume numbering remains:
- `SYS = 0`
- `_ADMIN = 1`
- further configured volumes start at `2`