Clean up for public release: docs, zero warnings, no hardcoded paths
Documentation: - docs/aacs.md — AACS encryption (1.0 + 2.0), key resolution, decrypt - docs/udf.md — UDF 2.50 filesystem with metadata partitions - docs/mpls.md — MPLS playlist format, STN stream table - docs/clpi.md — CLPI clip info, EP map, sector extents - docs/architecture.md — library module map, design principles - docs/drive-access.md — drive sessions, SCSI transport, unlock Code cleanup: - Zero compiler warnings - Removed all debug eprintln from library code - No hardcoded private paths — KEYDB tests use KEYDB_PATH env var - KEYDB search locations as named constants - drive.rs: extracted create_platform(), deduplicated open methods - lib.rs: updated doc examples to show Disc::scan() API - Fixed UDF file reads (partition_start, not metadata_start) - Exported KeySource from disc module
This commit is contained in:
MattJackson
@@ -0,0 +1,180 @@
|
||||
# libfreemkv Architecture
|
||||
|
||||
Open source optical drive access library for 4K UHD Blu-ray, Blu-ray, and DVD.
|
||||
Rust library with no external dependencies at runtime -- profiles are bundled,
|
||||
AACS keys are derived internally, and all SCSI communication is handled in-process.
|
||||
|
||||
**Repository:** <https://github.com/freemkv/libfreemkv>
|
||||
**License:** AGPL-3.0-only
|
||||
|
||||
---
|
||||
|
||||
## Design Principles
|
||||
|
||||
1. **CLI is dumb.** All drive communication, disc parsing, AACS decryption, and
|
||||
format handling live in the library. CLI binaries are thin wrappers that call
|
||||
`DriveSession::open()` and `Disc::scan()`.
|
||||
|
||||
2. **No external files.** 206 drive profiles are compiled into the binary via
|
||||
`include_str!`. No configuration directory, no runtime file lookups for drive
|
||||
support.
|
||||
|
||||
3. **Transparent AACS.** The `ContentReader` decrypts on the fly when keys are
|
||||
available. Callers read cleartext sectors without knowing whether the disc
|
||||
was encrypted.
|
||||
|
||||
4. **Structured errors, no English.** Every error has a numeric code (E1000-E7000).
|
||||
The library never formats user-facing messages -- applications do that.
|
||||
|
||||
5. **Library-agnostic.** No concept of "supported" vs "unsupported" drives at a
|
||||
policy level. If a profile exists, the library uses it.
|
||||
|
||||
---
|
||||
|
||||
## Module Map
|
||||
|
||||
```
|
||||
libfreemkv (lib.rs)
|
||||
│
|
||||
├── Drive Access
|
||||
│ ├── drive DriveSession — open, identify, unlock, read
|
||||
│ ├── scsi ScsiTransport trait + SG_IO implementation
|
||||
│ ├── platform/ Platform trait — per-chipset command handlers
|
||||
│ │ └── mt1959 MediaTek MT1959 driver (LG, ASUS, hp)
|
||||
│ ├── profile DriveProfile loading, matching, bundled JSON
|
||||
│ ├── identity DriveId from INQUIRY + GET_CONFIG 010C
|
||||
│ └── speed DriveSpeed enum, SET CD SPEED CDB builder
|
||||
│
|
||||
├── Disc Scanning
|
||||
│ ├── disc Disc::scan() — titles, streams, extents, AACS setup
|
||||
│ ├── udf UDF 2.50 filesystem reader (metadata partitions)
|
||||
│ ├── mpls MPLS playlist parser — clips, streams, STN table
|
||||
│ ├── clpi CLPI clip info parser — EP map, sector extents
|
||||
│ └── jar BD-J JAR label extraction (audio/subtitle names)
|
||||
│
|
||||
├── Encryption
|
||||
│ ├── aacs KEYDB parsing, VUK lookup, MKB processing, unit decryption
|
||||
│ └── aacs_handshake ECDH bus authentication, Volume ID, Read Data Key
|
||||
│
|
||||
└── error Error enum with numeric codes E1000-E7000
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## Drive Access Flow
|
||||
|
||||
```
|
||||
DriveSession::open("/dev/sr0")
|
||||
│
|
||||
├─ scsi::open() Open /dev/sr0 via SG_IO
|
||||
├─ DriveId::from_drive() INQUIRY + GET_CONFIG 010C
|
||||
├─ profile::find_by_drive_id() Match against 206 bundled profiles
|
||||
├─ Platform::new() Instantiate chipset driver (Mt1959)
|
||||
└─ Platform::unlock() Activate raw disc access mode
|
||||
```
|
||||
|
||||
After open, the session provides:
|
||||
- `read_sectors(lba, count, buf)` -- raw sector reads (through platform driver)
|
||||
- `read_disc(lba, count, buf)` -- standard READ(10) for filesystem data
|
||||
- `scsi_execute(cdb, dir, buf, timeout)` -- arbitrary SCSI commands
|
||||
- `status()`, `calibrate()`, `read_config()`, `read_register()`
|
||||
|
||||
---
|
||||
|
||||
## Disc Scanning Flow
|
||||
|
||||
```
|
||||
Disc::scan(&mut session, &ScanOptions)
|
||||
│
|
||||
├─ READ CAPACITY Get disc size in sectors
|
||||
├─ udf::read_filesystem() Parse UDF 2.50 (AVDP → VDS → metadata → FSD → root)
|
||||
├─ For each BDMV/PLAYLIST/*.mpls:
|
||||
│ ├─ mpls::parse() Extract play items, STN streams
|
||||
│ └─ For each clip:
|
||||
│ └─ clpi::parse() EP map → sector extents for the clip's time range
|
||||
├─ Detect AACS Check for /AACS directory on disc
|
||||
└─ Disc::setup_aacs() Handshake + KEYDB → VUK → unit keys (if encrypted)
|
||||
```
|
||||
|
||||
The result is a `Disc` with:
|
||||
- `titles: Vec<Title>` -- sorted by duration, each with streams and sector extents
|
||||
- `aacs: Option<AacsState>` -- decryption keys if available
|
||||
- `encrypted: bool` -- whether the disc uses AACS
|
||||
|
||||
---
|
||||
|
||||
## AACS Decryption
|
||||
|
||||
Four key resolution paths, tried in order:
|
||||
|
||||
| Path | Method | Speed |
|
||||
|------|--------|-------|
|
||||
| 1 | VUK lookup by disc hash in KEYDB.cfg | Instant |
|
||||
| 2 | Media Key + Volume ID from KEYDB → derive VUK | Fast |
|
||||
| 3 | Processing Keys + MKB → Media Key → VUK | Medium |
|
||||
| 4 | Device Keys + MKB subset-difference tree → VUK | Slow |
|
||||
|
||||
The AACS handshake (`aacs_handshake`) performs ECDH key agreement over the
|
||||
AACS 1.0 160-bit elliptic curve to obtain:
|
||||
- **Volume ID** -- needed for VUK derivation (paths 2-4)
|
||||
- **Read Data Key** -- needed for AACS 2.0 (UHD) bus decryption
|
||||
|
||||
Content decryption uses AES-128-CBC on 6144-byte aligned units. The
|
||||
`ContentReader` handles this transparently.
|
||||
|
||||
---
|
||||
|
||||
## Error Codes
|
||||
|
||||
All errors carry a numeric code for programmatic handling. No user-facing text
|
||||
is baked into the library.
|
||||
|
||||
| Range | Category | Examples |
|
||||
|-------|----------|----------|
|
||||
| E1xxx | Device errors | `DeviceNotFound`, `DevicePermission` |
|
||||
| E2xxx | Profile errors | `UnsupportedDrive`, `ProfileNotFound`, `ProfileParse` |
|
||||
| E3xxx | Unlock errors | `UnlockFailed`, `SignatureMismatch`, `NotUnlocked`, `NotCalibrated` |
|
||||
| E4xxx | SCSI errors | `ScsiError`, `ScsiTimeout` |
|
||||
| E5xxx | I/O errors | `IoError` (wraps `std::io::Error`) |
|
||||
| E6xxx | Disc format errors | `DiscError` (UDF, MPLS, CLPI parse failures) |
|
||||
| E7xxx | AACS errors | `AacsError` (key resolution, handshake, decryption) |
|
||||
|
||||
---
|
||||
|
||||
## Platform Support
|
||||
|
||||
| Platform | Transport | Status |
|
||||
|----------|-----------|--------|
|
||||
| Linux | SG_IO ioctl on `/dev/sr*` | Implemented |
|
||||
| macOS | IOKit SCSI passthrough | Planned |
|
||||
| Windows | SPTI (`IOCTL_SCSI_PASS_THROUGH_DIRECT`) | Planned |
|
||||
|
||||
The `ScsiTransport` trait abstracts the platform. Adding a new platform requires
|
||||
implementing `execute()` for that OS and wiring it into `scsi::open()`.
|
||||
|
||||
---
|
||||
|
||||
## Chipset Support
|
||||
|
||||
| Chipset | Drives | Status |
|
||||
|---------|--------|--------|
|
||||
| MediaTek MT1959 | LG, ASUS, hp | Implemented (206 profiles) |
|
||||
| Renesas RS8xxx/RS9xxx | Pioneer, some HL-DT-ST | Planned |
|
||||
|
||||
The `Platform` trait abstracts chipset-specific commands. Each chipset implements
|
||||
10 handlers (unlock, config, register, calibrate, keepalive, status, probe,
|
||||
read_sectors, timing). All handlers are accessed via SCSI READ BUFFER with
|
||||
chipset-specific mode and buffer ID bytes.
|
||||
|
||||
---
|
||||
|
||||
## Build
|
||||
|
||||
```
|
||||
cargo build --release
|
||||
```
|
||||
|
||||
Linux builds produce a static library and two binaries (`freemkv-info`,
|
||||
`freemkv-test`). The `libc` dependency is Linux-only. On non-Linux platforms,
|
||||
the library compiles but `scsi::open()` returns a platform-not-supported error
|
||||
until the IOKit/SPTI backends are implemented.
|
||||
Reference in New Issue
Block a user