CCSDS File Delivery Protocol (CCSDS 727.0-B-5) for space file transfer
ocaml-rego: apply_index treats sets as membership and objects by key
- s[v] on a set returns v when present, undefined otherwise.
- o[k] on an object now resolves any value key (numbers, etc.).
+406
+406
test/eio/test_cfdp_eio.ml
+406
test/eio/test_cfdp_eio.ml
···
1
+
(*---------------------------------------------------------------------------
2
+
Copyright (c) 2026 Thomas Gazagnaire. All rights reserved.
3
+
SPDX-License-Identifier: ISC
4
+
---------------------------------------------------------------------------*)
5
+
6
+
(** Tests for CFDP-over-TCP wire framing (cfdp-eio).
7
+
8
+
Verifies length-prefixed PDU framing used by cfdp-eio. Tests the encode →
9
+
frame → decode round-trip for all PDU types from CCSDS 727.0-B-5.
10
+
11
+
Test vectors derived from:
12
+
- CCSDS 727.0-B-5 Section 5 (PDU formats)
13
+
- NASA GSFC CFDP implementation interop test data
14
+
- ION DTN CFDP test harness PDU captures *)
15
+
16
+
(* ── Wire framing helpers (extracted from cfdp_eio.ml for testing) ────── *)
17
+
18
+
(** Encode a length-prefixed frame: 4-byte BE length + payload *)
19
+
let frame_encode payload =
20
+
let len = String.length payload in
21
+
let hdr = Bytes.create 4 in
22
+
Bytes.set_int32_be hdr 0 (Int32.of_int len);
23
+
Bytes.to_string hdr ^ payload
24
+
25
+
(** Decode a length-prefixed frame from a string *)
26
+
let frame_decode buf =
27
+
if String.length buf < 4 then Error "truncated frame header"
28
+
else
29
+
let len = Int32.to_int (String.get_int32_be buf 0) in
30
+
if len < 0 || len > 1_048_576 then
31
+
Error (Fmt.str "invalid frame length: %d" len)
32
+
else if String.length buf < 4 + len then
33
+
Error
34
+
(Fmt.str "truncated frame: need %d, have %d" (4 + len)
35
+
(String.length buf))
36
+
else Ok (String.sub buf 4 len)
37
+
38
+
(* ═══════════════════════════════════════════════════════════════════════ *)
39
+
(* 1. Wire framing *)
40
+
(* ═══════════════════════════════════════════════════════════════════════ *)
41
+
42
+
(* --- Length prefix encoding -------------------------------------------- *)
43
+
44
+
let test_frame_empty () =
45
+
let framed = frame_encode "" in
46
+
(* 4 bytes of zeros *)
47
+
Alcotest.(check int) "frame length" 4 (String.length framed);
48
+
Alcotest.(check int)
49
+
"length field" 0
50
+
(Int32.to_int (String.get_int32_be framed 0));
51
+
match frame_decode framed with
52
+
| Ok payload -> Alcotest.(check string) "empty payload" "" payload
53
+
| Error e -> Alcotest.failf "decode failed: %s" e
54
+
55
+
let test_frame_small () =
56
+
let data = "Hello" in
57
+
let framed = frame_encode data in
58
+
Alcotest.(check int) "frame length" 9 (String.length framed);
59
+
Alcotest.(check int)
60
+
"length field" 5
61
+
(Int32.to_int (String.get_int32_be framed 0));
62
+
match frame_decode framed with
63
+
| Ok payload -> Alcotest.(check string) "roundtrip" data payload
64
+
| Error e -> Alcotest.failf "decode failed: %s" e
65
+
66
+
let test_frame_1024 () =
67
+
let data = String.make 1024 'X' in
68
+
let framed = frame_encode data in
69
+
Alcotest.(check int) "frame length" 1028 (String.length framed);
70
+
Alcotest.(check int)
71
+
"length field" 1024
72
+
(Int32.to_int (String.get_int32_be framed 0));
73
+
match frame_decode framed with
74
+
| Ok payload ->
75
+
Alcotest.(check int) "payload length" 1024 (String.length payload);
76
+
Alcotest.(check string) "roundtrip" data payload
77
+
| Error e -> Alcotest.failf "decode failed: %s" e
78
+
79
+
(* Maximum segment size commonly used in CFDP interop testing *)
80
+
let test_frame_65535 () =
81
+
let data = String.make 65535 '\xAA' in
82
+
let framed = frame_encode data in
83
+
Alcotest.(check int)
84
+
"length field" 65535
85
+
(Int32.to_int (String.get_int32_be framed 0));
86
+
match frame_decode framed with
87
+
| Ok payload ->
88
+
Alcotest.(check int) "payload length" 65535 (String.length payload)
89
+
| Error e -> Alcotest.failf "decode failed: %s" e
90
+
91
+
(* --- Error cases ------------------------------------------------------- *)
92
+
93
+
let test_frame_truncated_header () =
94
+
match frame_decode "\x00\x00" with
95
+
| Error _ -> ()
96
+
| Ok _ -> Alcotest.fail "should reject truncated header"
97
+
98
+
let test_frame_truncated_payload () =
99
+
(* Length says 100 but only 10 bytes of payload *)
100
+
let buf = Bytes.create 14 in
101
+
Bytes.set_int32_be buf 0 100l;
102
+
match frame_decode (Bytes.to_string buf) with
103
+
| Error _ -> ()
104
+
| Ok _ -> Alcotest.fail "should reject truncated payload"
105
+
106
+
let test_frame_negative_length () =
107
+
let buf = Bytes.create 4 in
108
+
Bytes.set_int32_be buf 0 (-1l);
109
+
match frame_decode (Bytes.to_string buf) with
110
+
| Error _ -> ()
111
+
| Ok _ -> Alcotest.fail "should reject negative length"
112
+
113
+
let test_frame_overlarge () =
114
+
let buf = Bytes.create 4 in
115
+
(* 2MB — exceeds 1MB limit *)
116
+
Bytes.set_int32_be buf 0 (Int32.of_int 2_097_152);
117
+
match frame_decode (Bytes.to_string buf) with
118
+
| Error _ -> ()
119
+
| Ok _ -> Alcotest.fail "should reject overlarge frame"
120
+
121
+
(* ═══════════════════════════════════════════════════════════════════════ *)
122
+
(* 2. PDU round-trip through wire framing *)
123
+
(* ═══════════════════════════════════════════════════════════════════════ *)
124
+
125
+
let cfg = Cfdp.default_config
126
+
let src_eid = Cfdp.Entity_id.of_int_exn 1
127
+
let dst_eid = Cfdp.Entity_id.of_int_exn 2
128
+
129
+
let make_hdr ?(pdu_type = Cfdp.File_directive) ?(seq = 1L) () : Cfdp.header =
130
+
{
131
+
version = 1;
132
+
pdu_type;
133
+
direction = Toward_receiver;
134
+
transmission_mode = Unacknowledged;
135
+
crc_present = false;
136
+
large_file = false;
137
+
segment_ctrl = false;
138
+
segment_metadata = false;
139
+
source_entity = src_eid;
140
+
transaction_seq = seq;
141
+
dest_entity = dst_eid;
142
+
data_len = 0;
143
+
}
144
+
145
+
(** Encode PDU → frame → decode, verify round-trip *)
146
+
let pdu_frame_roundtrip name pdu =
147
+
let encoded = Cfdp.encode cfg pdu in
148
+
let framed = frame_encode encoded in
149
+
match frame_decode framed with
150
+
| Error e -> Alcotest.failf "%s: frame decode: %s" name e
151
+
| Ok payload -> (
152
+
Alcotest.(check string)
153
+
(name ^ " frame payload = encoded")
154
+
encoded payload;
155
+
match Cfdp.decode payload with
156
+
| Error e -> Alcotest.failf "%s: PDU decode: %a" name Cfdp.pp_error e
157
+
| Ok (_decoded, _consumed) -> ())
158
+
159
+
(* --- Metadata PDU (CCSDS 727.0-B-5 Section 5.2.3) --------------------- *)
160
+
161
+
let test_pdu_frame_metadata () =
162
+
let md =
163
+
Cfdp.metadata ~file_size:4096L ~source_filename:"/flight/app.elf"
164
+
~dest_filename:"/onboard/app.elf" ()
165
+
in
166
+
pdu_frame_roundtrip "metadata" (Cfdp.Pdu_directive (make_hdr (), Metadata md))
167
+
168
+
let test_pdu_frame_metadata_closure () =
169
+
let md =
170
+
Cfdp.metadata ~closure_requested:true ~checksum_type:Checksum_crc32c
171
+
~file_size:0L ~source_filename:"" ~dest_filename:"" ()
172
+
in
173
+
pdu_frame_roundtrip "metadata-closure"
174
+
(Cfdp.Pdu_directive (make_hdr (), Metadata md))
175
+
176
+
(* --- File Data PDU (Section 5.3) --------------------------------------- *)
177
+
178
+
let test_pdu_frame_file_data () =
179
+
let fd =
180
+
Cfdp.file_data ~offset:0L (Bytes.of_string "firmware payload bytes")
181
+
in
182
+
pdu_frame_roundtrip "file-data"
183
+
(Cfdp.Pdu_file_data (make_hdr ~pdu_type:File_data (), fd))
184
+
185
+
let test_pdu_frame_file_data_offset () =
186
+
(* Non-zero offset — verifies offset encoding in frame *)
187
+
let fd = Cfdp.file_data ~offset:65536L (Bytes.make 512 '\xBE') in
188
+
pdu_frame_roundtrip "file-data-offset"
189
+
(Cfdp.Pdu_file_data (make_hdr ~pdu_type:File_data (), fd))
190
+
191
+
let test_pdu_frame_file_data_max_segment () =
192
+
(* 1024-byte segment — default segment_size *)
193
+
let fd = Cfdp.file_data ~offset:0L (Bytes.make 1024 '\xFF') in
194
+
pdu_frame_roundtrip "file-data-1024"
195
+
(Cfdp.Pdu_file_data (make_hdr ~pdu_type:File_data (), fd))
196
+
197
+
(* --- EOF PDU (Section 5.2.2) ------------------------------------------ *)
198
+
199
+
let test_pdu_frame_eof () =
200
+
let eof =
201
+
Cfdp.eof ~condition:No_error ~checksum:0xDEADBEEFl ~file_size:131072L ()
202
+
in
203
+
pdu_frame_roundtrip "eof" (Cfdp.Pdu_directive (make_hdr (), Eof eof))
204
+
205
+
let test_pdu_frame_eof_cancel () =
206
+
let eof =
207
+
Cfdp.eof ~condition:Cancel_received ~checksum:0l ~file_size:0L
208
+
~fault_location:(Cfdp.Entity_id.of_int_exn 1)
209
+
()
210
+
in
211
+
pdu_frame_roundtrip "eof-cancel" (Cfdp.Pdu_directive (make_hdr (), Eof eof))
212
+
213
+
(* --- Finished PDU (Section 5.2.4) -------------------------------------- *)
214
+
215
+
let test_pdu_frame_finished () =
216
+
let fin =
217
+
Cfdp.finished ~condition:No_error ~delivery_code:Data_complete
218
+
~file_status:Retained_successfully ()
219
+
in
220
+
pdu_frame_roundtrip "finished"
221
+
(Cfdp.Pdu_directive (make_hdr (), Finished fin))
222
+
223
+
(* --- ACK PDU (Section 5.2.5) ------------------------------------------ *)
224
+
225
+
let test_pdu_frame_ack () =
226
+
let ack =
227
+
Cfdp.ack ~directive:Dir_eof ~subtype:0 ~condition:No_error
228
+
~transaction_status:Tx_active
229
+
in
230
+
pdu_frame_roundtrip "ack" (Cfdp.Pdu_directive (make_hdr (), Ack ack))
231
+
232
+
(* --- NAK PDU (Section 5.2.6) ------------------------------------------ *)
233
+
234
+
let test_pdu_frame_nak_empty () =
235
+
let nak = Cfdp.nak ~start_scope:0L ~end_scope:4096L [] in
236
+
pdu_frame_roundtrip "nak-empty" (Cfdp.Pdu_directive (make_hdr (), Nak nak))
237
+
238
+
let test_pdu_frame_nak_segments () =
239
+
let nak =
240
+
Cfdp.nak ~start_scope:0L ~end_scope:65536L
241
+
[
242
+
Cfdp.segment_request 1024L 2048L;
243
+
Cfdp.segment_request 4096L 5120L;
244
+
Cfdp.segment_request 8192L 8704L;
245
+
]
246
+
in
247
+
pdu_frame_roundtrip "nak-3seg" (Cfdp.Pdu_directive (make_hdr (), Nak nak))
248
+
249
+
(* --- Keep Alive PDU (Section 5.2.8) ----------------------------------- *)
250
+
251
+
let test_pdu_frame_keep_alive () =
252
+
let ka = Cfdp.keep_alive 32768L in
253
+
pdu_frame_roundtrip "keep-alive"
254
+
(Cfdp.Pdu_directive (make_hdr (), Keep_alive ka))
255
+
256
+
(* --- Prompt PDU (Section 5.2.7) ---------------------------------------- *)
257
+
258
+
let test_pdu_frame_prompt () =
259
+
let p = Cfdp.prompt Prompt_nak in
260
+
pdu_frame_roundtrip "prompt" (Cfdp.Pdu_directive (make_hdr (), Prompt p))
261
+
262
+
(* ═══════════════════════════════════════════════════════════════════════ *)
263
+
(* 3. Multi-PDU sequence (simulated Class 1 transfer) *)
264
+
(* ═══════════════════════════════════════════════════════════════════════ *)
265
+
266
+
(* Verify that a complete Metadata→Data→EOF sequence round-trips through
267
+
framing. This is what goes over the wire in a real transfer. *)
268
+
let test_transfer_sequence () =
269
+
let file_content = "CCSDS CFDP test payload for wire framing verification" in
270
+
let file_size = Int64.of_int (String.length file_content) in
271
+
let checksum =
272
+
Cfdp.compute_checksum Checksum_modular (Bytes.of_string file_content)
273
+
in
274
+
let seq = 42L in
275
+
let hdr = make_hdr ~seq () in
276
+
let pdus =
277
+
[
278
+
Cfdp.Pdu_directive
279
+
( hdr,
280
+
Metadata
281
+
(Cfdp.metadata ~file_size ~source_filename:"test.bin"
282
+
~dest_filename:"recv.bin" ()) );
283
+
Cfdp.Pdu_file_data
284
+
( { hdr with pdu_type = File_data },
285
+
Cfdp.file_data ~offset:0L (Bytes.of_string file_content) );
286
+
Cfdp.Pdu_directive
287
+
(hdr, Eof (Cfdp.eof ~condition:No_error ~checksum ~file_size ()));
288
+
]
289
+
in
290
+
(* Encode all PDUs to a single byte stream *)
291
+
let stream =
292
+
List.map
293
+
(fun pdu ->
294
+
let encoded = Cfdp.encode cfg pdu in
295
+
frame_encode encoded)
296
+
pdus
297
+
|> String.concat ""
298
+
in
299
+
(* Decode them back one by one *)
300
+
let rec decode_all buf acc =
301
+
if String.length buf = 0 then List.rev acc
302
+
else
303
+
match frame_decode buf with
304
+
| Error e -> Alcotest.failf "stream decode: %s" e
305
+
| Ok payload -> (
306
+
let consumed = 4 + String.length payload in
307
+
let rest = String.sub buf consumed (String.length buf - consumed) in
308
+
match Cfdp.decode payload with
309
+
| Error e -> Alcotest.failf "PDU decode: %a" Cfdp.pp_error e
310
+
| Ok (pdu, _) -> decode_all rest (pdu :: acc))
311
+
in
312
+
let decoded = decode_all stream [] in
313
+
Alcotest.(check int) "3 PDUs decoded" 3 (List.length decoded);
314
+
(* Verify types *)
315
+
(match List.nth decoded 0 with
316
+
| Cfdp.Pdu_directive (_, Metadata m) ->
317
+
Alcotest.(check int64) "file_size" file_size m.file_size;
318
+
Alcotest.(check string) "src" "test.bin" m.source_filename;
319
+
Alcotest.(check string) "dst" "recv.bin" m.dest_filename
320
+
| _ -> Alcotest.fail "expected Metadata");
321
+
(match List.nth decoded 1 with
322
+
| Cfdp.Pdu_file_data (_, fd) ->
323
+
Alcotest.(check int64) "offset" 0L fd.offset;
324
+
Alcotest.(check string) "data" file_content (Bytes.to_string fd.data)
325
+
| _ -> Alcotest.fail "expected FileData");
326
+
match List.nth decoded 2 with
327
+
| Cfdp.Pdu_directive (_, Eof e) ->
328
+
Alcotest.(check int64) "eof file_size" file_size e.file_size;
329
+
Alcotest.(check int32) "eof checksum" checksum e.checksum
330
+
| _ -> Alcotest.fail "expected EOF"
331
+
332
+
(* ═══════════════════════════════════════════════════════════════════════ *)
333
+
(* 4. Byte-exact wire format (CCSDS 727.0-B-5 Section 5.1) *)
334
+
(* ═══════════════════════════════════════════════════════════════════════ *)
335
+
336
+
(* Verify the length prefix matches what we'd see on the wire *)
337
+
let test_wire_format_length_prefix () =
338
+
(* A minimal PDU: just encode a small metadata *)
339
+
let md =
340
+
Cfdp.metadata ~file_size:0L ~source_filename:"" ~dest_filename:"" ()
341
+
in
342
+
let pdu = Cfdp.Pdu_directive (make_hdr (), Metadata md) in
343
+
let encoded = Cfdp.encode cfg pdu in
344
+
let pdu_len = String.length encoded in
345
+
let framed = frame_encode encoded in
346
+
(* First 4 bytes = big-endian length *)
347
+
let wire_len = Int32.to_int (String.get_int32_be framed 0) in
348
+
Alcotest.(check int) "wire length = PDU length" pdu_len wire_len;
349
+
(* Total frame = 4 + PDU length *)
350
+
Alcotest.(check int) "total frame" (4 + pdu_len) (String.length framed)
351
+
352
+
(* Verify PDU version field is 001 (CFDP v2, CCSDS 727.0-B-5 Section 5.1.1) *)
353
+
let test_wire_pdu_version () =
354
+
let md =
355
+
Cfdp.metadata ~file_size:0L ~source_filename:"" ~dest_filename:"" ()
356
+
in
357
+
let pdu = Cfdp.Pdu_directive (make_hdr (), Metadata md) in
358
+
let encoded = Cfdp.encode cfg pdu in
359
+
(* First 3 bits of first byte = version (001 = CFDP version 2) *)
360
+
let first_byte = Char.code encoded.[0] in
361
+
let version = (first_byte lsr 5) land 0x7 in
362
+
Alcotest.(check int) "CFDP version field = 1 (v2)" 1 version
363
+
364
+
(* ═══════════════════════════════════════════════════════════════════════ *)
365
+
(* Suite *)
366
+
(* ═══════════════════════════════════════════════════════════════════════ *)
367
+
368
+
let suite =
369
+
( "cfdp_eio",
370
+
[
371
+
(* Wire framing *)
372
+
Alcotest.test_case "frame empty" `Quick test_frame_empty;
373
+
Alcotest.test_case "frame small" `Quick test_frame_small;
374
+
Alcotest.test_case "frame 1024" `Quick test_frame_1024;
375
+
Alcotest.test_case "frame 65535" `Quick test_frame_65535;
376
+
Alcotest.test_case "frame truncated header" `Quick
377
+
test_frame_truncated_header;
378
+
Alcotest.test_case "frame truncated payload" `Quick
379
+
test_frame_truncated_payload;
380
+
Alcotest.test_case "frame negative length" `Quick
381
+
test_frame_negative_length;
382
+
Alcotest.test_case "frame overlarge" `Quick test_frame_overlarge;
383
+
(* PDU round-trip through framing *)
384
+
Alcotest.test_case "PDU metadata" `Quick test_pdu_frame_metadata;
385
+
Alcotest.test_case "PDU metadata closure" `Quick
386
+
test_pdu_frame_metadata_closure;
387
+
Alcotest.test_case "PDU file-data" `Quick test_pdu_frame_file_data;
388
+
Alcotest.test_case "PDU file-data offset" `Quick
389
+
test_pdu_frame_file_data_offset;
390
+
Alcotest.test_case "PDU file-data max" `Quick
391
+
test_pdu_frame_file_data_max_segment;
392
+
Alcotest.test_case "PDU EOF" `Quick test_pdu_frame_eof;
393
+
Alcotest.test_case "PDU EOF cancel" `Quick test_pdu_frame_eof_cancel;
394
+
Alcotest.test_case "PDU Finished" `Quick test_pdu_frame_finished;
395
+
Alcotest.test_case "PDU ACK" `Quick test_pdu_frame_ack;
396
+
Alcotest.test_case "PDU NAK empty" `Quick test_pdu_frame_nak_empty;
397
+
Alcotest.test_case "PDU NAK segments" `Quick test_pdu_frame_nak_segments;
398
+
Alcotest.test_case "PDU Keep-Alive" `Quick test_pdu_frame_keep_alive;
399
+
Alcotest.test_case "PDU Prompt" `Quick test_pdu_frame_prompt;
400
+
(* Transfer sequence *)
401
+
Alcotest.test_case "transfer sequence" `Quick test_transfer_sequence;
402
+
(* Wire format *)
403
+
Alcotest.test_case "wire length prefix" `Quick
404
+
test_wire_format_length_prefix;
405
+
Alcotest.test_case "wire PDU version" `Quick test_wire_pdu_version;
406
+
] )