CCSDS Synchronization and Channel Coding (131.0-B, 231.0-B)
Add 8 new CCSDS/RFC protocol packages
- ocaml-rice: CCSDS 121.0-B lossless compression (Rice/Golomb)
- ocaml-udpcl: RFC 7122 UDP convergence layer for Bundle Protocol
- ocaml-erasure: CCSDS 131.5-B erasure correcting codes (GF(2^8))
- ocaml-short-ldpc: CCSDS 131.4-B short block-length LDPC
- ocaml-opm: CCSDS 502.0-B Orbit Parameter Message (KVN)
- ocaml-aem: CCSDS 504.0-B Attitude Ephemeris Message (KVN)
- ocaml-tdm: CCSDS 503.0-B Tracking Data Message (KVN)
- ocaml-rdm: CCSDS 508.1-B Re-entry Data Message (KVN)
+44
-15
+44
-15
fuzz/fuzz_sync.ml
+44
-15
fuzz/fuzz_sync.ml
···
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let prefix = Bytes.sub data 0 frame_len in
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if prefix <> frame then fail "roundtrip mismatch: prefix differs"
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-
(** Crash safety: random bytes -> Scc.Sync.decode -> should not crash. *)
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-
let test_decode_crash buf =
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let _ = Scc.Sync.Cltu.decode (Bytes.of_string buf) in
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-
()
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+
(** CLTU decode invariants: if decode succeeds, the decoded data must be
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non-empty and a multiple of 7 bytes (one codeblock = 7 data bytes). *)
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let test_decode_invariants buf =
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match Scc.Sync.Cltu.decode (Bytes.of_string buf) with
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| Ok (data, _remaining) ->
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let len = Bytes.length data in
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if len = 0 then fail "decode returned Ok with empty data";
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if len mod 7 <> 0 then
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fail
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(Fmt.str "decoded length %d is not a multiple of 7 (codeblock size)"
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len)
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| Error _ ->
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(* Error is fine for arbitrary input *)
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()
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(** BCH parity: random 7-byte block -> compute parity -> verify syndrome. *)
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let test_bch_parity buf =
···
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| Error e -> fail (Fmt.str "ASM decode failed: %a" Scc.Sync.pp_error e)
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| Ok (decoded, _) -> if decoded <> frame then fail "ASM roundtrip mismatch"
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-
(** ASM decode crash safety. *)
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let test_asm_decode_crash buf =
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let _ = Scc.Sync.Asm.decode (Bytes.of_string buf) in
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-
()
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+
(** ASM decode invariants: if decode succeeds, the decoded frame must be
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non-empty and shorter than the input (ASM prefix was stripped). *)
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let test_asm_decode_invariants buf =
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match Scc.Sync.Asm.decode (Bytes.of_string buf) with
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| Ok (decoded, _) ->
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if Bytes.length decoded = 0 && String.length buf > Scc.Sync.Asm.marker_len
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then fail "ASM decode returned Ok with empty frame"
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| Error _ ->
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(* Error is fine for arbitrary input *)
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()
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-
(** Cltu_sync crash safety: feed random bytes to sync parser. *)
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-
let test_cltu_sync_crash buf =
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(** Cltu_sync invariants: feed random bytes to sync parser. If a CLTU is found,
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the decoded frame must be non-empty and a multiple of 7 bytes. *)
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let test_cltu_sync_invariants buf =
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let state = Scc.Sync.Cltu_sync.init () in
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let _ = Scc.Sync.Cltu_sync.feed state (Bytes.of_string buf) in
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()
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let _state, result = Scc.Sync.Cltu_sync.feed state (Bytes.of_string buf) in
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match result with
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| Some (Ok decoded) ->
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let len = Bytes.length decoded in
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if len = 0 then fail "Cltu_sync found CLTU with empty decoded data";
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if len mod 7 <> 0 then
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fail
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(Fmt.str
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"Cltu_sync decoded length %d is not a multiple of 7 (codeblock \
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size)"
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len)
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| Some (Error _) | None ->
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(* Error or no complete CLTU is fine for arbitrary input *)
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()
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let suite =
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( "cltu",
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[
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test_case "CLTU roundtrip" [ bytes ] test_roundtrip;
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test_case "CLTU decode crash safety" [ bytes ] test_decode_crash;
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test_case "CLTU decode invariants" [ bytes ] test_decode_invariants;
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test_case "BCH parity" [ bytes ] test_bch_parity;
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test_case "ASM roundtrip" [ bytes ] test_asm_roundtrip;
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test_case "ASM decode crash safety" [ bytes ] test_asm_decode_crash;
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test_case "Cltu_sync crash safety" [ bytes ] test_cltu_sync_crash;
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test_case "ASM decode invariants" [ bytes ] test_asm_decode_invariants;
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test_case "Cltu_sync invariants" [ bytes ] test_cltu_sync_invariants;
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] )