-
Notifications
You must be signed in to change notification settings - Fork 0
/
eti2wireshark.py
executable file
·1130 lines (1023 loc) · 42.6 KB
/
eti2wireshark.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#!/usr/bin/env python3
# Generate Wireshark Dissectors for eletronic trading/market data
# protocols such as ETI/EOBI.
#
# Targets Wireshark 3.5 or later.
#
# SPDX-FileCopyrightText: © 2021 Georg Sauthoff <mail@gms.tf>
# SPDX-License-Identifier: GPL-2.0-or-later
import argparse
import itertools
import re
import sys
import xml.etree.ElementTree as ET
from etimodel import get_min_sizes, get_max_sizes
def get_used_types(st):
xs = set(y.get('type') for _, x in st.items() for y in x)
return xs
def get_data_types(d):
r = d.getroot()
x = r.find('DataTypes')
h = {}
for e in x:
h[e.get('name')] = e
return h
def get_structs(d):
r = d.getroot()
x = r.find('Structures')
h = {}
for e in x:
h[e.get('name')] = e
return h
def get_templates(st):
ts = []
for k, v in st.items():
if v.get('type') == 'Message':
ts.append((int(v.get('numericID')), k))
ts.sort()
return ts
def gen_header(proto, desc, o=sys.stdout):
if proto.startswith('eti') or proto.startswith('xti'):
ph = '#include "packet-tcp.h" // tcp_dissect_pdus()'
else:
ph = '#include "packet-udp.h" // udp_dissect_pdus()'
print(f'''// auto-generated by Georg Sauthoff's eti2wireshark.py
/* packet-eti.c
* Routines for {proto.upper()} dissection
* Copyright 2021, Georg Sauthoff <mail@gms.tf>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* The {desc} ({proto.upper()}) is an electronic trading protocol
* that is used by a few exchanges (Eurex, Xetra, ...).
*
* It's a Length-Tag based protocol consisting of mostly fix sized
* request/response messages.
*
* Links:
* https://en.wikipedia.org/wiki/List_of_electronic_trading_protocols#Europe
* https://github.com/gsauthof/python-eti#protocol-descriptions
* https://github.com/gsauthof/python-eti#protocol-introduction
*
*/
#include <config.h>
#include <epan/packet.h> // Should be first Wireshark include (other than config.h)
{ph}
#include <epan/expert.h> // expert info
#include <inttypes.h>
#include <stdio.h> // snprintf()
/* Prototypes */
/* (Required to prevent [-Wmissing-prototypes] warnings */
void proto_reg_handoff_{proto}(void);
void proto_register_{proto}(void);
''', file=o)
def name2ident(name):
ll = True
xs = []
for i, c in enumerate(name):
if c.isupper():
if i > 0 and ll:
xs.append('_')
xs.append(c.lower())
ll = False
else:
xs.append(c)
ll = True
return ''.join(xs)
def gen_enums(dt, ts, o=sys.stdout):
print('static const value_string template_id_vals[] = { // TemplateID', file=o)
min_tid, max_tid = ts[0][0], ts[-1][0]
xs = [None] * (max_tid - min_tid + 1)
for tid, name in ts:
xs[tid-min_tid] = name
for i, name in enumerate(xs):
if name is None:
print(f' {{ {min_tid + i}, "Unknown" }},', file=o)
else:
print(f' {{ {min_tid + i}, "{name}" }},', file=o)
print(''' { 0, NULL }
};
static value_string_ext template_id_vals_ext = VALUE_STRING_EXT_INIT(template_id_vals);''', file=o)
name2access = { 'TemplateID': '&template_id_vals_ext' }
dedup = {}
for name, e in dt.items():
vs = [ (x.get('value'), x.get('name')) for x in e.findall('ValidValue') ]
if not vs:
continue
if e.get('rootType') == 'String' and e.get('size') != '1':
continue
ident = name2ident(name)
nv = e.get('noValue')
ws = [ v[0] for v in vs ]
if nv not in ws:
if nv.startswith('0x0') and e.get('rootType') == 'String':
nv = '\0'
vs.append( (nv, 'NO_VALUE') )
if e.get('type') == 'int':
vs.sort(key = lambda x : int(x[0], 0))
else:
vs.sort(key = lambda x : ord(x[0]))
s = '-'.join(f'{v[0]}:{v[1]}' for v in vs)
x = dedup.get(s)
if x is None:
dedup[s] = name
else:
name2access[name] = name2access[x]
print(f'// {name} aliased by {x}', file=o)
continue
print(f'static const value_string {ident}_vals[] = {{ // {name}', file=o)
for i, v in enumerate(vs):
if e.get('rootType') == 'String':
k = f"'{v[0]}'" if ord(v[0]) != 0 else '0'
print(f''' {{ {k}, "{v[1]}" }},''', file=o)
else:
print(f' {{ {v[0]}, "{v[1]}" }},', file=o)
print(''' { 0, NULL }
};''', file=o)
if len(vs) > 7:
print(f'static value_string_ext {ident}_vals_ext = VALUE_STRING_EXT_INIT({ident}_vals);', file=o)
name2access[name] = f'&{ident}_vals_ext'
else:
name2access[name] = f'VALS({ident}_vals)'
return name2access
def get_fields(st, dt):
seen = {}
for name, e in st.items():
for m in e:
t = dt.get(m.get('type'))
if is_padding(t):
continue
if not (is_int(t) or is_fixed_string(t) or is_var_string(t)):
continue
name = m.get('name')
if name in seen:
if seen[name] != t:
raise RuntimeError(f'Mismatching type for: {name}')
else:
seen[name] = t
vs = list(seen.items())
vs.sort()
return vs
def gen_field_handles(st, dt, proto, o=sys.stdout):
print(f'''static expert_field ei_{proto}_counter_overflow = EI_INIT;
static expert_field ei_{proto}_invalid_template = EI_INIT;
static expert_field ei_{proto}_invalid_length = EI_INIT;''', file=o)
if not proto.startswith('eobi'):
print(f'static expert_field ei_{proto}_unaligned = EI_INIT;', file=o)
print(f'''static expert_field ei_{proto}_missing = EI_INIT;
static expert_field ei_{proto}_overused = EI_INIT;
''', file=o)
vs = get_fields(st, dt)
s = ', '.join('-1' for i in range(len(vs)))
print(f'static int hf_{proto}[] = {{ {s} }};', file=o)
print(f'''static int hf_{proto}_dscp_exec_summary = -1;
static int hf_{proto}_dscp_improved = -1;
static int hf_{proto}_dscp_widened = -1;''', file=o)
print('enum Field_Handle_Index {', file=o)
for i, (name, _) in enumerate(vs):
c = ' ' if i == 0 else ','
print(f' {c} {name.upper()}_FH_IDX', file=o)
print('};', file=o)
def type2ft(t):
if is_timestamp_ns(t):
return 'FT_ABSOLUTE_TIME'
if is_dscp(t):
return 'FT_UINT8'
if is_int(t):
if t.get('rootType') == 'String':
return 'FT_CHAR'
u = 'U' if is_unsigned(t) else ''
if t.get('size') is None:
raise RuntimeError(f'None size: {t.get("name")}')
size = int(t.get('size')) * 8
return f'FT_{u}INT{size}'
if is_fixed_string(t) or is_var_string(t):
# NB: technically, ETI fixed-strings are blank-padded,
# unless they are marked NO_VALUE, in that case
# the first byte is zero, followed by unspecified content.
# Also, some fixed-strings are zero-terminated, where again
# the bytes following the terminator are unspecified.
return 'FT_STRINGZTRUNC'
raise RuntimeError('unexpected type')
def type2enc(t):
if is_timestamp_ns(t):
return 'ABSOLUTE_TIME_UTC'
if is_dscp(t):
return 'BASE_HEX'
if is_int(t):
if t.get('rootType') == 'String':
# NB: basically only used when enum and value is unknown
return 'BASE_HEX'
else:
return 'BASE_DEC'
if is_fixed_string(t) or is_var_string(t):
# previously 'STR_ASCII', which was removed upstream
# cf. 19dcb725b61e384f665ad4b955f3b78f63e626d9
return 'BASE_NONE'
raise RuntimeError('unexpected type')
def gen_field_info(st, dt, n2enum, proto='eti', o=sys.stdout):
print(' static hf_register_info hf[] ={', file=o)
vs = get_fields(st, dt)
for i, (name, t) in enumerate(vs):
c = ' ' if i == 0 else ','
ft = type2ft(t)
enc = type2enc(t)
if is_enum(t) and not is_dscp(t):
vals = n2enum[t.get('name')]
if vals.startswith('&'):
extra_enc = '| BASE_EXT_STRING'
else:
extra_enc = ''
else:
vals = 'NULL'
extra_enc = ''
print(f''' {c} {{ &hf_{proto}[{name.upper()}_FH_IDX],
{{ "{name}", "{proto}.{name.lower()}",
{ft}, {enc}{extra_enc}, {vals}, 0x0,
NULL, HFILL }}
}}''', file=o)
print(f''' , {{ &hf_{proto}_dscp_exec_summary,
{{ "DSCP_ExecSummary", "{proto}.dscp_execsummary",
FT_BOOLEAN, 8, NULL, 0x10,
NULL, HFILL }}
}}
, {{ &hf_{proto}_dscp_improved,
{{ "DSCP_Improved", "{proto}.dscp_improved",
FT_BOOLEAN, 8, NULL, 0x20,
NULL, HFILL }}
}}
, {{ &hf_{proto}_dscp_widened,
{{ "DSCP_Widened", "{proto}.dscp_widened",
FT_BOOLEAN, 8, NULL, 0x40,
NULL, HFILL }}
}}''', file=o)
print(' };', file=o)
def gen_subtree_handles(st, proto='eti', o=sys.stdout):
ns = [ name for name, e in st.items() if e.get('type') != 'Message' ]
ns.sort()
s = ', '.join('-1' for i in range(len(ns) + 1))
h = dict( (n, i) for i, n in enumerate(ns, 1) )
print(f'static gint ett_{proto}[] = {{ {s} }};', file=o)
print(f'static gint ett_{proto}_dscp = -1;', file=o)
return h
def gen_subtree_array(st, proto='eti', o=sys.stdout):
n = sum(1 for name, e in st.items() if e.get('type') != 'Message')
n += 1
s = ', '.join(f'&ett_{proto}[{i}]' for i in range(n))
print(f' static gint * const ett[] = {{ {s}, &ett_{proto}_dscp }};', file=o)
def gen_fields_table(st, dt, sh, o=sys.stdout):
name2off = {}
off = 0
names = []
for name, e in st.items():
if e.get('type') == 'Message':
continue
if name.endswith('Comp'):
s = name[:-4]
name2off[name] = off
off += len(s) + 1
names.append(s)
s = '\\0'.join(names)
print(f' static const char struct_names[] = "{s}";', file=o)
xs = [ x for x in st.items() if x[1].get('type') != 'Message' ]
xs += [ x for x in st.items() if x[1].get('type') == 'Message' ]
print(' static const struct ETI_Field fields[] = {', file=o)
i = 0
fields2idx = {}
for name, e in xs:
fields2idx[name] = i
print(f' // {name}@{i}', file=o)
counters = {}
cnt = 0
for m in e:
t = dt.get(m.get('type'))
c = ' ' if i == 0 else ','
typ = ''
size = int(t.get('size')) if t is not None else 0
rep = ''
fh = f'{m.get("name").upper()}_FH_IDX'
sub = ''
if is_padding(t):
print(f' {c} {{ ETI_PADDING, 0, {size}, 0, 0 }}', file=o)
elif is_fixed_point(t):
if size != 8:
raise RuntimeError('only supporting 8 byte fixed point')
fraction = int(t.get('precision'))
if fraction > 16:
raise RuntimeError('unusual high precisio in fixed point')
print(f' {c} {{ ETI_FIXED_POINT, {fraction}, {size}, {fh}, 0 }}', file=o)
elif is_timestamp_ns(t):
if size != 8:
raise RuntimeError('only supporting timestamps')
print(f' {c} {{ ETI_TIMESTAMP_NS, 0, {size}, {fh}, 0 }}', file=o)
elif is_dscp(t):
print(f' {c} {{ ETI_DSCP, 0, {size}, {fh}, 0 }}', file=o)
elif is_int(t):
u = 'U' if is_unsigned(t) else ''
if t.get('rootType') == 'String':
typ = 'ETI_CHAR'
else:
typ = f'ETI_{u}INT'
if is_enum(t):
typ += '_ENUM'
if t.get('type') == 'Counter':
counters[m.get('name')] = cnt
suf = f' // <- counter@{cnt}'
if cnt > 7:
raise RuntimeError(f'too many counters in message: {name}')
rep = cnt
cnt += 1
if typ != 'ETI_UINT':
raise RuntimeError('only unsigned counters supported')
if size > 2:
raise RuntimeError('only smaller counters supported')
typ = 'ETI_COUNTER'
ett_idx = t.get('maxValue')
else:
rep = 0
suf = ''
ett_idx = 0
print(f' {c} {{ {typ}, {rep}, {size}, {fh}, {ett_idx} }}{suf}', file=o)
elif is_fixed_string(t):
print(f' {c} {{ ETI_STRING, 0, {size}, {fh}, 0 }}', file=o)
elif is_var_string(t):
k = m.get('counter')
x = counters[k]
print(f' {c} {{ ETI_VAR_STRING, {x}, {size}, {fh}, 0 }}', file=o)
else:
a = m.get('type')
fields_idx = fields2idx[a]
k = m.get('counter')
if k:
counter_off = counters[k]
typ = 'ETI_VAR_STRUCT'
else:
counter_off = 0
typ = 'ETI_STRUCT'
names_off = name2off[m.get('type')]
ett_idx = sh[a]
print(f' {c} {{ {typ}, {counter_off}, {names_off}, {fields_idx}, {ett_idx} }} // {m.get("name")}', file=o)
i += 1
print(' , { ETI_EOF, 0, 0, 0, 0 }', file=o)
i += 1
print(' };', file=o)
return fields2idx
def gen_template_table(min_templateid, n, ts, fields2idx, o=sys.stdout):
xs = [ '-1' ] * n
for tid, name in ts:
xs[tid - min_templateid] = f'{fields2idx[name]} /* {name} */'
s = '\n , '.join(xs)
print(f' static const int16_t tid2fidx[] = {{\n {s}\n }};', file=o)
def gen_sizes_table(min_templateid, n, st, dt, ts, proto, o=sys.stdout):
is_eobi = proto.startswith('eobi')
xs = [ '0' if is_eobi else '{ 0, 0}' ] * n
min_s = get_min_sizes(st, dt)
max_s = get_max_sizes(st, dt)
if is_eobi:
for tid, name in ts:
xs[tid - min_templateid] = f'{max_s[name]} /* {name} */'
else:
for tid, name in ts:
xs[tid - min_templateid] = f'{{ {min_s[name]}, {max_s[name]} }} /* {name} */'
s = '\n , '.join(xs)
if is_eobi:
print(f' static const uint32_t tid2size[] = {{\n {s}\n }};', file=o)
else:
print(f' static const uint32_t tid2size[{n}][2] = {{\n {s}\n }};', file=o)
# yes, usage attribute of single fields depends on the context
# otherwise, we could just put the information into the fields table
# Example: EOBI.PacketHeader.MessageHeader.MsgSeqNum is unused whereas
# it's required in the EOBI ExecutionSummary and other messages
def gen_usage_table(min_templateid, n, ts, ams, o=sys.stdout):
def map_usage(m):
x = m.get('usage')
if x == 'mandatory':
return 0
elif x == 'optional':
return 1
elif x == 'unused':
return 2
else:
raise RuntimeError(f'unknown usage value: {x}')
h = {}
i = 0
print(' static const unsigned char usages[] = {', file=o)
for am in ams:
name = am.get("name")
tid = int(am.get('numericID'))
print(f' // {name}', file=o)
h[tid] = i
for e in am:
if e.tag == 'Group':
print(f' //// {e.get("type")}', file=o)
for m in e:
if m.get('hidden') == 'true' or pad_re.match(m.get('name')):
continue
k = ' ' if i == 0 else ','
print(f' {k} {map_usage(m)} // {m.get("name")}#{i}', file=o)
i += 1
print(' ///', file=o)
else:
if e.get('hidden') == 'true' or pad_re.match(e.get('name')):
continue
k = ' ' if i == 0 else ','
print(f' {k} {map_usage(e)} // {e.get("name")}#{i}', file=o)
i += 1
# NB: the last element is a filler to simplify the out-of-bounds check
# (cf. the uidx DISSECTOR_ASSER_CMPUINIT() before the switch statement)
# when the ETI_EOF of the message whose usage information comes last
# is reached
print(f' , 0 // filler', file=o)
print(' };', file=o)
xs = [ '-1' ] * n
t2n = dict(ts)
for tid, uidx in h.items():
name = t2n[tid]
xs[tid - min_templateid] = f'{uidx} /* {name} */'
s = '\n , '.join(xs)
print(f' static const int16_t tid2uidx[] = {{\n {s}\n }};', file=o)
def gen_dscp_table(proto, o=sys.stdout):
print(f''' static int * const dscp_bits[] = {{
&hf_{proto}_dscp_exec_summary,
&hf_{proto}_dscp_improved,
&hf_{proto}_dscp_widened,
NULL
}};''', file=o)
def mk_int_case(size, signed, proto):
signed_str = 'i' if signed else ''
unsigned_str = '' if signed else 'u'
fmt_str = 'i' if signed else 'u'
if size == 2:
size_str = 's'
elif size == 4:
size_str = 'l'
elif size == 8:
size_str = '64'
type_str = f'g{unsigned_str}int{size * 8}'
no_value_str = f'INT{size * 8}_MIN' if signed else f'UINT{size * 8}_MAX'
pt_size = '64' if size == 8 else ''
if signed:
hex_str = '0x80' + '00' * (size - 1)
else:
hex_str = '0x' + 'ff' * size
if size == 1:
fn = f'tvb_get_g{unsigned_str}int8'
else:
fn = f'tvb_get_letoh{signed_str}{size_str}'
s = f'''case {size}:
{{
{type_str} x = {fn}(tvb, off);
if (x == {no_value_str}) {{
proto_item *e = proto_tree_add_{unsigned_str}int{pt_size}_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "NO_VALUE ({hex_str})");
if (!usages[uidx])
expert_add_info_format(pinfo, e, &ei_{proto}_missing, "required value is missing");
}} else {{
proto_item *e = proto_tree_add_{unsigned_str}int{pt_size}_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "%" PRI{fmt_str}{size * 8}, x);
if (usages[uidx] == 2)
expert_add_info_format(pinfo, e, &ei_{proto}_overused, "unused value is set");
}}
}}
break;'''
return s
def gen_dissect_structs(o=sys.stdout):
print('''
enum ETI_Type {
ETI_EOF,
ETI_PADDING,
ETI_UINT,
ETI_INT,
ETI_UINT_ENUM,
ETI_INT_ENUM,
ETI_COUNTER,
ETI_FIXED_POINT,
ETI_TIMESTAMP_NS,
ETI_CHAR,
ETI_STRING,
ETI_VAR_STRING,
ETI_STRUCT,
ETI_VAR_STRUCT,
ETI_DSCP
};
struct ETI_Field {
uint8_t type;
uint8_t counter_off; // offset into counter array
// if ETI_COUNTER => storage
// if ETI_VAR_STRING or ETI_VAR_STRUCT => load
// to get length or repeat count
// if ETI_FIXED_POINT: #fractional digits
uint16_t size; // or offset into struct_names if ETI_STRUCT/ETI_VAR_STRUCT
uint16_t field_handle_idx; // or index into fields array if ETI_STRUCT/ETI_VAR_STRUT
uint16_t ett_idx; // index into ett array if ETI_STRUCT/ETI_VAR_STRUCT
// or max value if ETI_COUNTER
};
''', file=o)
def gen_dissect_fn(st, dt, ts, sh, ams, proto, o=sys.stdout):
if proto.startswith('eti') or proto.startswith('xti'):
bl_fn = 'tvb_get_letohl'
template_off = 4
else:
bl_fn = 'tvb_get_letohs'
template_off = 2
print(f'''/* This method dissects fully reassembled messages */
static int
dissect_{proto}_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{{
col_set_str(pinfo->cinfo, COL_PROTOCOL, "{proto.upper()}");
col_clear(pinfo->cinfo, COL_INFO);
guint16 templateid = tvb_get_letohs(tvb, {template_off});
const char *template_str = val_to_str_ext(templateid, &template_id_vals_ext, "Unknown {proto.upper()} template: 0x%04x");
col_add_fstr(pinfo->cinfo, COL_INFO, "%s", template_str);
/* create display subtree for the protocol */
proto_item *ti = proto_tree_add_item(tree, proto_{proto}, tvb, 0, -1, ENC_NA);
guint32 bodylen= {bl_fn}(tvb, 0);
proto_item_append_text(ti, ", %s (%" PRIu16 "), BodyLen: %u", template_str, templateid, bodylen);
proto_tree *root = proto_item_add_subtree(ti, ett_{proto}[0]);
''', file=o)
min_templateid = ts[0][0]
max_templateid = ts[-1][0]
n = max_templateid - min_templateid + 1
fields2idx = gen_fields_table(st, dt, sh, o)
gen_template_table(min_templateid, n, ts, fields2idx, o)
gen_sizes_table(min_templateid, n, st, dt, ts, proto, o)
gen_usage_table(min_templateid, n, ts, ams, o)
gen_dscp_table(proto, o)
print(f''' if (templateid < {min_templateid} || templateid > {max_templateid}) {{
proto_tree_add_expert_format(root, pinfo, &ei_{proto}_invalid_template, tvb, {template_off}, 4,
"Template ID out of range: %" PRIu16, templateid);
return tvb_captured_length(tvb);
}}
int fidx = tid2fidx[templateid - {min_templateid}];
if (fidx == -1) {{
proto_tree_add_expert_format(root, pinfo, &ei_{proto}_invalid_template, tvb, {template_off}, 4,
"Unallocated Template ID: %" PRIu16, templateid);
return tvb_captured_length(tvb);
}}''', file=o)
if proto.startswith('eobi'):
print(f''' if (bodylen != tid2size[templateid - {min_templateid}]) {{
proto_tree_add_expert_format(root, pinfo, &ei_{proto}_invalid_length, tvb, 0, {template_off},
"Unexpected BodyLen value of %" PRIu32 ", expected: %" PRIu32, bodylen, tid2size[templateid - {min_templateid}]);
}}''', file=o)
else:
print(f''' if (bodylen < tid2size[templateid - {min_templateid}][0] || bodylen > tid2size[templateid - {min_templateid}][1]) {{
if (tid2size[templateid - {min_templateid}][0] != tid2size[templateid - {min_templateid}][1])
proto_tree_add_expert_format(root, pinfo, &ei_{proto}_invalid_length, tvb, 0, {template_off},
"Unexpected BodyLen value of %" PRIu32 ", expected: %" PRIu32 "..%" PRIu32, bodylen, tid2size[templateid - {min_templateid}][0], tid2size[templateid - {min_templateid}][1]);
else
proto_tree_add_expert_format(root, pinfo, &ei_{proto}_invalid_length, tvb, 0, {template_off},
"Unexpected BodyLen value of %" PRIu32 ", expected: %" PRIu32, bodylen, tid2size[templateid - {min_templateid}][0]);
}}
if (bodylen % 8)
proto_tree_add_expert_format(root, pinfo, &ei_{proto}_unaligned, tvb, 0, {template_off},
"BodyLen value of %" PRIu32 " is not divisible by 8", bodylen);
''', file=o)
print(f''' int uidx = tid2uidx[templateid - {min_templateid}];
DISSECTOR_ASSERT_CMPINT(uidx, >=, 0);
DISSECTOR_ASSERT_CMPUINT(((size_t)uidx), <, (sizeof usages / sizeof usages[0]));
''', file=o)
print(f''' int old_fidx = 0;
int old_uidx = 0;
unsigned top = 1;
unsigned counter[8] = {{0}};
unsigned off = 0;
unsigned struct_off = 0;
unsigned repeats = 0;
proto_tree *t = root;
while (top) {{
DISSECTOR_ASSERT_CMPINT(fidx, >=, 0);
DISSECTOR_ASSERT_CMPUINT(((size_t)fidx), <, (sizeof fields / sizeof fields[0]));
DISSECTOR_ASSERT_CMPINT(uidx, >=, 0);
DISSECTOR_ASSERT_CMPUINT(((size_t)uidx), <, (sizeof usages / sizeof usages[0]));
switch (fields[fidx].type) {{
case ETI_EOF:
DISSECTOR_ASSERT_CMPUINT(top, >=, 1);
DISSECTOR_ASSERT_CMPUINT(top, <=, 2);
if (t != root)
proto_item_set_len(t, off - struct_off);
if (repeats) {{
--repeats;
fidx = fields[old_fidx].field_handle_idx;
uidx = old_uidx;
t = proto_tree_add_subtree(root, tvb, off, -1, ett_{proto}[fields[old_fidx].ett_idx], NULL, &struct_names[fields[old_fidx].size]);
struct_off = off;
}} else {{
fidx = old_fidx + 1;
t = root;
--top;
}}
break;
case ETI_VAR_STRUCT:
case ETI_STRUCT:
DISSECTOR_ASSERT_CMPUINT(fields[fidx].counter_off, <, sizeof counter / sizeof counter[0]);
repeats = fields[fidx].type == ETI_VAR_STRUCT ? counter[fields[fidx].counter_off] : 1;
if (repeats) {{
--repeats;
t = proto_tree_add_subtree(root, tvb, off, -1, ett_{proto}[fields[fidx].ett_idx], NULL, &struct_names[fields[fidx].size]);
struct_off = off;
old_fidx = fidx;
old_uidx = uidx;
fidx = fields[fidx].field_handle_idx;
DISSECTOR_ASSERT_CMPUINT(top, ==, 1);
++top;
}} else {{
++fidx;
}}
break;
case ETI_PADDING:
off += fields[fidx].size;
++fidx;
break;
case ETI_CHAR:
proto_tree_add_item(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, ENC_ASCII);
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_STRING:
{{
guint8 c = tvb_get_guint8(tvb, off);
if (c)
proto_tree_add_item(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, ENC_ASCII);
else {{
proto_item *e = proto_tree_add_string(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, "NO_VALUE ('0x00...')");
if (!usages[uidx])
expert_add_info_format(pinfo, e, &ei_{proto}_missing, "required value is missing");
}}
}}
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_VAR_STRING:
DISSECTOR_ASSERT_CMPUINT(fields[fidx].counter_off, <, sizeof counter / sizeof counter[0]);
proto_tree_add_item(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, counter[fields[fidx].counter_off], ENC_ASCII);
off += counter[fields[fidx].counter_off];
++fidx;
++uidx;
break;
case ETI_COUNTER:
DISSECTOR_ASSERT_CMPUINT(fields[fidx].counter_off, <, sizeof counter / sizeof counter[0]);
DISSECTOR_ASSERT_CMPUINT(fields[fidx].size, <=, 2);
{{
switch (fields[fidx].size) {{
case 1:
{{
guint8 x = tvb_get_guint8(tvb, off);
if (x == UINT8_MAX) {{
proto_tree_add_uint_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "NO_VALUE (0xff)");
counter[fields[fidx].counter_off] = 0;
}} else {{
proto_item *e = proto_tree_add_uint_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "%" PRIu8, x);
if (x > fields[fidx].ett_idx) {{
counter[fields[fidx].counter_off] = fields[fidx].ett_idx;
expert_add_info_format(pinfo, e, &ei_{proto}_counter_overflow, "Counter overflow: %" PRIu8 " > %" PRIu16, x, fields[fidx].ett_idx);
}} else {{
counter[fields[fidx].counter_off] = x;
}}
}}
}}
break;
case 2:
{{
guint16 x = tvb_get_letohs(tvb, off);
if (x == UINT16_MAX) {{
proto_tree_add_uint_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "NO_VALUE (0xffff)");
counter[fields[fidx].counter_off] = 0;
}} else {{
proto_item *e = proto_tree_add_uint_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "%" PRIu16, x);
if (x > fields[fidx].ett_idx) {{
counter[fields[fidx].counter_off] = fields[fidx].ett_idx;
expert_add_info_format(pinfo, e, &ei_{proto}_counter_overflow, "Counter overflow: %" PRIu16 " > %" PRIu16, x, fields[fidx].ett_idx);
}} else {{
counter[fields[fidx].counter_off] = x;
}}
}}
}}
break;
}}
}}
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_UINT:
switch (fields[fidx].size) {{
{mk_int_case(1, False, proto)}
{mk_int_case(2, False, proto)}
{mk_int_case(4, False, proto)}
{mk_int_case(8, False, proto)}
}}
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_INT:
switch (fields[fidx].size) {{
{mk_int_case(1, True, proto)}
{mk_int_case(2, True, proto)}
{mk_int_case(4, True, proto)}
{mk_int_case(8, True, proto)}
}}
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_UINT_ENUM:
case ETI_INT_ENUM:
proto_tree_add_item(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, ENC_LITTLE_ENDIAN);
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_FIXED_POINT:
DISSECTOR_ASSERT_CMPUINT(fields[fidx].size, ==, 8);
DISSECTOR_ASSERT_CMPUINT(fields[fidx].counter_off, >, 0);
DISSECTOR_ASSERT_CMPUINT(fields[fidx].counter_off, <=, 16);
{{
gint64 x = tvb_get_letohi64(tvb, off);
if (x == INT64_MIN) {{
proto_item *e = proto_tree_add_int64_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "NO_VALUE (0x8000000000000000)");
if (!usages[uidx])
expert_add_info_format(pinfo, e, &ei_{proto}_missing, "required value is missing");
}} else {{
unsigned slack = fields[fidx].counter_off + 1;
if (x < 0)
slack += 1;
char s[21];
int n = snprintf(s, sizeof s, "%0*" PRIi64, slack, x);
DISSECTOR_ASSERT_CMPUINT(n, >, 0);
unsigned k = n - fields[fidx].counter_off;
proto_tree_add_int64_format_value(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, x, "%.*s.%s", k, s, s + k);
}}
}}
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_TIMESTAMP_NS:
DISSECTOR_ASSERT_CMPUINT(fields[fidx].size, ==, 8);
proto_tree_add_item(t, hf_{proto}[fields[fidx].field_handle_idx], tvb, off, fields[fidx].size, ENC_LITTLE_ENDIAN | ENC_TIME_NSECS);
off += fields[fidx].size;
++fidx;
++uidx;
break;
case ETI_DSCP:
DISSECTOR_ASSERT_CMPUINT(fields[fidx].size, ==, 1);
proto_tree_add_bitmask(t, tvb, off, hf_{proto}[fields[fidx].field_handle_idx], ett_{proto}_dscp, dscp_bits, ENC_LITTLE_ENDIAN);
off += fields[fidx].size;
++fidx;
++uidx;
break;
}}
}}
''', file=o)
print(''' return tvb_captured_length(tvb);
}
''', file=o)
print(f'''/* determine PDU length of protocol {proto.upper()} */
static guint
get_{proto}_message_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
{{
return (guint){bl_fn}(tvb, offset);
}}
''', file=o)
if proto.startswith('eobi'):
print(f'''static int
dissect_{proto}(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
void *data)
{{
return udp_dissect_pdus(tvb, pinfo, tree, 4, NULL,
get_{proto}_message_len, dissect_{proto}_message, data);
}}
''', file=o)
else:
print(f'''static int
dissect_{proto}(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
void *data)
{{
tcp_dissect_pdus(tvb, pinfo, tree, TRUE, 4 /* bytes to read for bodylen */,
get_{proto}_message_len, dissect_{proto}_message, data);
return tvb_captured_length(tvb);
}}
''', file=o)
def gen_register_fn(st, dt, n2enum, proto, desc, o=sys.stdout):
print(f'''void
proto_register_{proto}(void)
{{''', file=o)
gen_field_info(st, dt, n2enum, proto, o)
print(f''' static ei_register_info ei[] = {{
{{
&ei_{proto}_counter_overflow,
{{ "{proto}.counter_overflow", PI_PROTOCOL, PI_WARN, "Counter Overflow", EXPFILL }}
}},
{{
&ei_{proto}_invalid_template,
{{ "{proto}.invalid_template", PI_PROTOCOL, PI_ERROR, "Invalid Template ID", EXPFILL }}
}},
{{
&ei_{proto}_invalid_length,
{{ "{proto}.invalid_length", PI_PROTOCOL, PI_ERROR, "Invalid Body Length", EXPFILL }}
}},''', file=o)
if not proto.startswith('eobi'):
print(f''' {{
&ei_{proto}_unaligned,
{{ "{proto}.unaligned", PI_PROTOCOL, PI_ERROR, "A Body Length not divisible by 8 leads to unaligned followup messages", EXPFILL }}
}},''', file=o)
print(f''' {{
&ei_{proto}_missing,
{{ "{proto}.missing", PI_PROTOCOL, PI_WARN, "A required value is missing", EXPFILL }}
}},
{{
&ei_{proto}_overused,
{{ "{proto}.overused", PI_PROTOCOL, PI_WARN, "An unused value is set", EXPFILL }}
}}
}};''', file=o)
print(f''' proto_{proto} = proto_register_protocol("{desc}",
"{proto.upper()}", "{proto}");''', file=o)
print(f''' expert_module_t *expert_{proto} = expert_register_protocol(proto_{proto});
expert_register_field_array(expert_{proto}, ei, array_length(ei));''', file=o)
print(f' proto_register_field_array(proto_{proto}, hf, array_length(hf));',
file=o)
gen_subtree_array(st, proto, o)
print(' proto_register_subtree_array(ett, array_length(ett));', file=o)
print('}\n', file=o)
def gen_handoff_fn(proto, o=sys.stdout):
print(f'''void
proto_reg_handoff_{proto}(void)
{{
dissector_handle_t {proto}_handle = create_dissector_handle(dissect_{proto},
proto_{proto});
// cf. N7 Network Access Guide, e.g.
// https://www.xetra.com/xetra-en/technology/t7/system-documentation/release10-0/Release-10.0-2692700?frag=2692724
// https://www.xetra.com/resource/blob/2762078/388b727972b5122945eedf0e63c36920/data/N7-Network-Access-Guide-v2.0.59.pdf
''', file=o)
if proto.startswith('eti'):
print(f''' // NB: can only be called once for a port/handle pair ...
// dissector_add_uint_with_preference("tcp.port", 19006 /* LF PROD */, eti_handle);
dissector_add_uint("tcp.port", 19006 /* LF PROD */, {proto}_handle);
dissector_add_uint("tcp.port", 19043 /* PS PROD */, {proto}_handle);
dissector_add_uint("tcp.port", 19506 /* LF SIMU */, {proto}_handle);
dissector_add_uint("tcp.port", 19543 /* PS SIMU */, {proto}_handle);''', file=o)
elif proto.startswith('xti'):
print(f''' // NB: unfortunately, Cash-ETI shares the same ports as Derivatives-ETI ...
// We thus can't really add a well-know port for XTI.
// Use Wireshark's `Decode As...` or tshark's `-d tcp.port=19043,xti` feature
// to switch from ETI to XTI dissection.
dissector_add_uint_with_preference("tcp.port", 19042 /* dummy */, {proto}_handle);''', file=o)
else:
print(f''' static const int ports[] = {{
59000, // Snapshot EUREX US-allowed PROD
59001, // Incremental EUREX US-allowed PROD
59032, // Snapshot EUREX US-restricted PROD
59033, // Incremental EUREX US-restricted PROD
59500, // Snapshot EUREX US-allowed SIMU
59501, // Incremental EUREX US-allowed SIMU
59532, // Snapshot EUREX US-restricted SIMU
59533, // Incremental EUREX US-restricted SIMU
57000, // Snapshot FX US-allowed PROD
57001, // Incremental FX US-allowed PROD
57032, // Snapshot FX US-restricted PROD
57033, // Incremental FX US-restricted PROD
57500, // Snapshot FX US-allowed SIMU
57501, // Incremental FX US-allowed SIMU
57532, // Snapshot FX US-restricted SIMU
57533, // Incremental FX US-restricted SIMU
59000, // Snapshot Xetra PROD
59001, // Incremental Xetra PROD
59500, // Snapshot Xetra SIMU
59501, // Incremental Xetra SIMU
56000, // Snapshot Boerse Frankfurt PROD
56001, // Incremental Boerse Frankfurt PROD
56500, // Snapshot Boerse Frankfurt SIMU
56501 // Incremental Boerse Frankfurt SIMU
}};
for (unsigned i = 0; i < sizeof ports / sizeof ports[0]; ++i)
dissector_add_uint("udp.port", ports[i], {proto}_handle);''', file=o)
print('}', file=o)
def is_int(t):
if t is not None:
r = t.get('rootType')
return r in ('int', 'floatDecimal') or (r == 'String' and t.get('size') == '1')
return False
def is_enum(t):
if t is not None:
r = t.get('rootType')
if r == 'int' or (r == 'String' and t.get('size') == '1'):
return t.find('ValidValue') is not None
return False
def is_fixed_point(t):
return t is not None and t.get('rootType') == 'floatDecimal'