summaryrefslogtreecommitdiffstats
path: root/src/vpp-api/lua/vpp-lapi.lua
blob: ebfd032b0962173076cae651c55695cae4fdf10b (plain)
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
--[[
/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
]]

-- json decode/encode from https://gist.github.com/tylerneylon/59f4bcf316be525b30ab
-- licensed by the author tylerneylon into public domain. Thanks!

local json = {}

-- Internal functions.

local function kind_of(obj)
  if type(obj) ~= 'table' then return type(obj) end
  local i = 1
  for _ in pairs(obj) do
    if obj[i] ~= nil then i = i + 1 else return 'table' end
  end
  if i == 1 then return 'table' else return 'array' end
end

local function escape_str(s)
  local in_char  = {'\\', '"', '/', '\b', '\f', '\n', '\r', '\t'}
  local out_char = {'\\', '"', '/',  'b',  'f',  'n',  'r',  't'}
  for i, c in ipairs(in_char) do
    s = s:gsub(c, '\\' .. out_char[i])
  end
  return s
end

-- Returns pos, did_find; there are two cases:
-- 1. Delimiter found: pos = pos after leading space + delim; did_find = true.
-- 2. Delimiter not found: pos = pos after leading space;     did_find = false.
-- This throws an error if err_if_missing is true and the delim is not found.
local function skip_delim(str, pos, delim, err_if_missing)
  pos = pos + #str:match('^%s*', pos)
  if str:sub(pos, pos) ~= delim then
    if err_if_missing then
      error('Expected ' .. delim .. ' near position ' .. pos)
    end
    return pos, false
  end
  return pos + 1, true
end

-- Expects the given pos to be the first character after the opening quote.
-- Returns val, pos; the returned pos is after the closing quote character.
local function parse_str_val(str, pos, val)
  val = val or ''
  local early_end_error = 'End of input found while parsing string.'
  if pos > #str then error(early_end_error) end
  local c = str:sub(pos, pos)
  if c == '"'  then return val, pos + 1 end
  if c ~= '\\' then return parse_str_val(str, pos + 1, val .. c) end
  -- We must have a \ character.
  local esc_map = {b = '\b', f = '\f', n = '\n', r = '\r', t = '\t'}
  local nextc = str:sub(pos + 1, pos + 1)
  if not nextc then error(early_end_error) end
  return parse_str_val(str, pos + 2, val .. (esc_map[nextc] or nextc))
end

-- Returns val, pos; the returned pos is after the number's final character.
local function parse_num_val(str, pos)
  local num_str = str:match('^-?%d+%.?%d*[eE]?[+-]?%d*', pos)
  local val = tonumber(num_str)
  if not val then error('Error parsing number at position ' .. pos .. '.') end
  return val, pos + #num_str
end


-- Public values and functions.

function json.stringify(obj, as_key)
  local s = {}  -- We'll build the string as an array of strings to be concatenated.
  local kind = kind_of(obj)  -- This is 'array' if it's an array or type(obj) otherwise.
  if kind == 'array' then
    if as_key then error('Can\'t encode array as key.') end
    s[#s + 1] = '['
    for i, val in ipairs(obj) do
      if i > 1 then s[#s + 1] = ', ' end
      s[#s + 1] = json.stringify(val)
    end
    s[#s + 1] = ']'
  elseif kind == 'table' then
    if as_key then error('Can\'t encode table as key.') end
    s[#s + 1] = '{'
    for k, v in pairs(obj) do
      if #s > 1 then s[#s + 1] = ', ' end
      s[#s + 1] = json.stringify(k, true)
      s[#s + 1] = ':'
      s[#s + 1] = json.stringify(v)
    end
    s[#s + 1] = '}'
  elseif kind == 'string' then
    return '"' .. escape_str(obj) .. '"'
  elseif kind == 'number' then
    if as_key then return '"' .. tostring(obj) .. '"' end
    return tostring(obj)
  elseif kind == 'boolean' then
    return tostring(obj)
  elseif kind == 'nil' then
    return 'null'
  else
    error('Unjsonifiable type: ' .. kind .. '.')
  end
  return table.concat(s)
end

json.null = {}  -- This is a one-off table to represent the null value.

function json.parse(str, pos, end_delim)
  pos = pos or 1
  if pos > #str then error('Reached unexpected end of input.') end
  local pos = pos + #str:match('^%s*', pos)  -- Skip whitespace.
  local first = str:sub(pos, pos)
  if first == '{' then  -- Parse an object.
    local obj, key, delim_found = {}, true, true
    pos = pos + 1
    while true do
      key, pos = json.parse(str, pos, '}')
      if key == nil then return obj, pos end
      if not delim_found then error('Comma missing between object items.') end
      pos = skip_delim(str, pos, ':', true)  -- true -> error if missing.
      obj[key], pos = json.parse(str, pos)
      pos, delim_found = skip_delim(str, pos, ',')
    end
  elseif first == '[' then  -- Parse an array.
    local arr, val, delim_found = {}, true, true
    pos = pos + 1
    while true do
      val, pos = json.parse(str, pos, ']')
      if val == nil then return arr, pos end
      if not delim_found then error('Comma missing between array items.') end
      arr[#arr + 1] = val
      pos, delim_found = skip_delim(str, pos, ',')
    end
  elseif first == '"' then  -- Parse a string.
    return parse_str_val(str, pos + 1)
  elseif first == '-' or first:match('%d') then  -- Parse a number.
    return parse_num_val(str, pos)
  elseif first == end_delim then  -- End of an object or array.
    return nil, pos + 1
  else  -- Parse true, false, or null.
    local literals = {['true'] = true, ['false'] = false, ['null'] = json.null}
    for lit_str, lit_val in pairs(literals) do
      local lit_end = pos + #lit_str - 1
      if str:sub(pos, lit_end) == lit_str then return lit_val, lit_end + 1 end
    end
    local pos_info_str = 'position ' .. pos .. ': ' .. str:sub(pos, pos + 10)
    error('Invalid json syntax starting at ' .. pos_info_str)
  end
end


local vpp = {}

local ffi = require("ffi")

--[[

The basic type definitions. A bit of weird gymnastic with
unionization of the hton* and ntoh* functions results
is to make handling of signed and unsigned types a bit cleaner,
essentially building typecasting into a C union.

The vl_api_opaque_message_t is a synthetic type assumed to have
enough storage to hold the entire API message regardless of the type.
During the operation it is casted to the specific message struct types.

]]


ffi.cdef([[

typedef uint8_t u8;
typedef int8_t i8;
typedef uint16_t u16;
typedef int16_t i16;
typedef uint32_t u32;
typedef int32_t i32;
typedef uint64_t u64;
typedef int64_t i64;
typedef double f64;
typedef float f32;

#pragma pack(1)
typedef union {
  u16 u16;
  i16 i16;
} lua_ui16t;

#pragma pack(1)
typedef union {
  u32 u32;
  i32 i32;
} lua_ui32t;

u16 ntohs(uint16_t hostshort);
u16 htons(uint16_t hostshort);
u32 htonl(uint32_t along);
u32 ntohl(uint32_t along);
void *memset(void *s, int c, size_t n);
void *memcpy(void *dest, void *src, size_t n);

#pragma pack(1)
typedef struct _vl_api_opaque_message {
  u16 _vl_msg_id;
  u8  data[65536];
} vl_api_opaque_message_t;
]])


-- CRC-based version stuff

local crc32c_table = ffi.new('const uint32_t[256]',
  { 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
  0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
  0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
  0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
  0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
  0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
  0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
  0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
  0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
  0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
  0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
  0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
  0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
  0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
  0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
  0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
  0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
  0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
  0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
  0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
  0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
  0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
  0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
  0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
  0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
  0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
  0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
  0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
  0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
  0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
  0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
  0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
  0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
  0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
  0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
  0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
  0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
  0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
  0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
  0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
  0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
  0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
  0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
  0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
  0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
  0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
  0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
  0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
  0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
  0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
  0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
  0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
  0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
  0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
  0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
  0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
  0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
  0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
  0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
  0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
  0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
  0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
  0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
  0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351 }
);

local function CRC8(crc, d)
  return bit.bxor(bit.rshift(crc, 8), crc32c_table[bit.band(0xff, bit.bxor(crc, d))])
end

local function CRC16(crc, d)
  crc = CRC8(crc, bit.band(d, 0xFF))
  d = bit.rshift(d, 8)
  crc = CRC8(crc, bit.band(d, 0xFF))
  return crc
end

local function string_crc(str, crc)
  for i=1,#str do
    -- print("S", i, string.byte(str, i), string.char(string.byte(str, i)))
    crc = CRC8(crc, string.byte(str, i))
  end
  return crc
end

local tokens = {
  { ["match"] =' ', ["act"]             = { }  },
  { ["match"] ='\n', ["act"]             = { }  },
  { ["match"] ="manual_endian", ["act"]  = { "NODE_MANUAL_ENDIAN", "MANUAL_ENDIAN",    276 } },
  { ["match"] ="define", ["act"]         = { "NODE_DEFINE",        "DEFINE",           267 } },
  { ["match"] ="dont_trace", ["act"]     = { "NODE_DONT_TRACE",    "DONT_TRACE",       279 } },
  { ["match"] ="f64", ["act"]            = { "NODE_F64",           "PRIMTYPE",         string_crc } },
  { ["match"] ="i16", ["act"]            = { "NODE_I16",           "PRIMTYPE",         string_crc } },
  { ["match"] ="i32", ["act"]            = { "NODE_I32",           "PRIMTYPE",         string_crc } },
  { ["match"] ="i64", ["act"]            = { "NODE_I64",           "PRIMTYPE",         string_crc } },
  { ["match"] ="i8", ["act"]             = { "NODE_I8",            "PRIMTYPE",         string_crc } },
  { ["match"] ="manual_print", ["act"]   = { "NODE_MANUAL_PRINT",  "MANUAL_PRINT",     275 } },
  { ["match"] ="noversion", ["act"]      = { "NODE_NOVERSION",     "NOVERSION",        274 } },
  { ["match"] ="packed", ["act"]         = { "NODE_PACKED",        "TPACKED",          266 } },
  { ["match"] ="typeonly", ["act"]       = { "NODE_TYPEONLY",      "TYPEONLY",         278 } },
  { ["match"] ="u16", ["act"]            = { "NODE_U16",           "PRIMTYPE",         string_crc } },
  { ["match"] ="u32", ["act"]            = { "NODE_U32",           "PRIMTYPE",         string_crc } },
  { ["match"] ="u64", ["act"]            = { "NODE_U64",           "PRIMTYPE",         string_crc } },
  { ["match"] ="u8", ["act"]             = { "NODE_U8",            "PRIMTYPE",         string_crc } },
  { ["match"] ="union", ["act"]          = { "NODE_UNION",         "UNION",            271 } },
  { ["match"] ="uword", ["act"]          = { "NODE_UWORD",         "PRIMTYPE",         string_crc } },
  { ["match"] ="%(", ["act"]             = { "NODE_LPAR",          "LPAR",             259 } },
  { ["match"] ="%)", ["act"]             = { "NODE_RPAR",          "RPAR",             258 } },
  { ["match"] =";", ["act"]              = { "NODE_SEMI",          "SEMI",             260 } },
  { ["match"] ="%[", ["act"]             = { "NODE_LBRACK",        "LBRACK",           261 } },
  { ["match"] ="%]", ["act"]             = { "NODE_RBRACK",        "RBRACK",           262 } },
  { ["match"] ="%{", ["act"]             = { "NODE_LCURLY",        "LCURLY",           268 } },
  { ["match"] ="%}", ["act"]             = { "NODE_RCURLY",        "RCURLY",           269 } },
  { ["match"] ='%b""', ["act"]           = { "NODE_STRING",        "STRING",           string_crc } },
  { ["match"] ='%b@@', ["act"]           = { "NODE_HELPER",        "HELPER_STRING",    string_crc } },
  -- TODO: \ must be consumed
  { ["match"] ='[_a-zA-Z][_a-zA-Z0-9]*',
                       ["act"]           = { "NODE_NAME",          "NAME",             string_crc } },
  { ["match"] ='[0-9]+', ["act"]         = { "NODE_NUMBER",        "NUMBER",           string_crc } },
  { ["match"] ='#[^\n]+', ["act"]            = { "NODE_PRAGMA",        "PRAGMA",           nil } },
}


function vpp.crc_version_string(data)
  local input_crc = 0
  -- Get rid of comments
  data = data:gsub("/%*.-%*/", "")
  data = data:gsub("//[^\n]+", "")
  -- print(data)
  idx = 1
  while (true) do
    local matched = nil
    for k, v in ipairs(tokens) do
      if not matched then
        local x, y, cap = string.find(data, v["match"], idx)
        if x == idx then
          matched = { ["node"] = v["act"], ["x"] = x, ["y"] = y, ["cap"] = cap, ["chars"] = string.sub(data, x, y)  }
          -- print(k, v, x, y, cap, matched.chars, matched.node[0] )
        end
      end
    end
    if matched then
      idx = idx + (matched.y - matched.x + 1)
      if matched.node[1] then
        local act = matched.node[3]
        if type(act) == "function" then
          input_crc = act(matched.chars, input_crc)
        elseif type(act) == "number" then
          input_crc = CRC16(input_crc, act)
        end
        -- print(vpp.dump(matched))
      end
    else
      -- print("NOT MATCHED!")
      local crc = CRC16(input_crc, 0xFFFFFFFF)
      return string.sub(string.format("%x", crc), -8)
    end
  end
end


function vpp.dump(o)
   if type(o) == 'table' then
      local s = '{ '
      for k,v in pairs(o) do
         if type(k) ~= 'number' then k = '"'..k..'"' end
         s = s .. '['..k..'] = ' .. vpp.dump(v) .. ','
      end
      return s .. '} '
   else
      return tostring(o)
   end
end

function vpp.hex_dump(buf)
  local ret = {}
  for i=1,math.ceil(#buf/16) * 16 do
    if (i-1) % 16 == 0 then table.insert(ret, string.format('%08X  ', i-1)) end
    table.insert(ret, ( i > #buf and '   ' or string.format('%02X ', buf:byte(i)) ))
    if i %  8 == 0 then table.insert(ret, ' ') end
    if i % 16 == 0 then table.insert(ret, buf:sub(i-16+1, i):gsub('%c','.')..'\n' ) end
  end
  return table.concat(ret)
end


function vpp.c_str(text_in)
  local text = text_in -- \000 will be helpfully added by ffi.copy
  local c_str = ffi.new("char[?]", #text+1)
  ffi.copy(c_str, text)
  return c_str
end


function vpp.init(vpp, args)
  local pneum_api = args.pneum_api or [[
 int cough_pneum_attach(char *pneum_path, char *cough_path);
 int pneum_connect(char *name, char *chroot_prefix, void *cb);
 int pneum_disconnect(void);
 int pneum_read(char **data, int *l);
 int pneum_write(char *data, int len);
 void pneum_free(char *data);
 uint32_t pneum_get_msg_index(unsigned char * name);
]]

  vpp.pneum_path = args.pneum_path
  ffi.cdef(pneum_api)
  local init_res = 0
  vpp.pneum = ffi.load(vpp.pneum_path)
  if (init_res < 0) then
    return nil
  end

  vpp.next_msg_num = 1
  vpp.msg_name_to_number = {}
  vpp.msg_name_to_fields = {}
  vpp.msg_number_to_name = {}
  vpp.msg_number_to_type = {}
  vpp.msg_number_to_pointer_type = {}
  vpp.msg_name_to_crc = {}
  vpp.c_type_to_fields = {}
  vpp.events = {}
  vpp.plugin_version = {}
  vpp.is_connected = false


  vpp.t_lua2c = {}
  vpp.t_c2lua = {}
  vpp.t_lua2c["u8"] = function(c_type, src, dst_c_ptr)
    if type(src) == "string" then
      -- ffi.copy adds a zero byte at the end. Grrr.
      -- ffi.copy(dst_c_ptr, src)
      ffi.C.memcpy(dst_c_ptr, vpp.c_str(src), #src)
      return(#src)
    elseif type(src) == "table" then
      for i,v in ipairs(src) do
        ffi.cast("u8 *", dst_c_ptr)[i-1] = v
      end
      return(#src)
    else
      return 1, src -- ffi.cast("u8", src)
    end
  end
  vpp.t_c2lua["u8"] = function(c_type, src_ptr, src_len)
    if src_len then
      return ffi.string(src_ptr, src_len)
    else
      return (tonumber(src_ptr))
    end
  end

  vpp.t_lua2c["u16"] = function(c_type, src, dst_c_ptr)
    if type(src) == "table" then
      for i,v in ipairs(src) do
        ffi.cast("u16 *", dst_c_ptr)[i-1] = ffi.C.htons(v)
      end
      return(2 * #src)
    else
      return 2, (ffi.C.htons(src))
    end
  end
  vpp.t_c2lua["u16"] = function(c_type, src_ptr, src_len)
    if src_len then
      local out = {}
      for i = 0,src_len-1 do
        out[i+1] = tonumber(ffi.C.ntohs(src_ptr[i]))
      end
      return out
    else
      return (tonumber(ffi.C.ntohs(src_ptr)))
    end
  end

  vpp.t_lua2c["u32"] = function(c_type, src, dst_c_ptr)
    if type(src) == "table" then
      for i,v in ipairs(src) do
        ffi.cast("u32 *", dst_c_ptr)[i-1] = ffi.C.htonl(v)
      end
      return(4 * #src)
    else
      return 4, (ffi.C.htonl(src))
    end
  end
  vpp.t_c2lua["u32"] = function(c_type, src_ptr, src_len)
    if src_len then
      local out = {}
      for i = 0,src_len-1 do
        out[i+1] = tonumber(ffi.C.ntohl(src_ptr[i]))
      end
      return out
    else
      return (tonumber(ffi.C.ntohl(src_ptr)))
    end
  end
  vpp.t_lua2c["i32"] = function(c_type, src, dst_c_ptr)
    if type(src) == "table" then
      for i,v in ipairs(src) do
        ffi.cast("i32 *", dst_c_ptr)[i-1] = ffi.C.htonl(v)
      end
      return(4 * #src)
    else
      return 4, (ffi.C.htonl(src))
    end
  end
  vpp.t_c2lua["i32"] = function(c_type, src_ptr, src_len)
    local ntohl = function(src)
      local u32val = ffi.cast("u32", src)
      local ntohlval = (ffi.C.ntohl(u32val))
      local out = tonumber(ffi.cast("i32", ntohlval + 0LL))
      return out
    end
    if src_len then
      local out = {}
      for i = 0,src_len-1 do
        out[i+1] = tonumber(ntohl(src_ptr[i]))
      end
    else
      return (tonumber(ntohl(src_ptr)))
    end
  end

  vpp.t_lua2c["u64"] = function(c_type, src, dst_c_ptr)
    if type(src) == "table" then
      for i,v in ipairs(src) do
        ffi.cast("u64 *", dst_c_ptr)[i-1] = v --- FIXME ENDIAN
      end
      return(8 * #src)
    else
      return 8, ffi.cast("u64", src) --- FIXME ENDIAN
    end
  end
  vpp.t_c2lua["u64"] = function(c_type, src_ptr, src_len)
    if src_len then
      local out = {}
      for i = 0,src_len-1 do
        out[i+1] = tonumber(src_ptr[i]) -- FIXME ENDIAN
      end
      return out
    else
      return (tonumber(src_ptr)) --FIXME ENDIAN
    end
  end




  vpp.t_lua2c["__MSG__"] = function(c_type, src, dst_c_ptr)
    local dst = ffi.cast(c_type .. " *", dst_c_ptr)
    local additional_len = 0
    local fields_info = vpp.c_type_to_fields[c_type]
    -- print("__MSG__ type: " .. tostring(c_type))
    ffi.C.memset(dst_c_ptr, 0, ffi.sizeof(dst[0]))
    -- print(vpp.dump(fields_info))
    -- print(vpp.dump(src))
    for k,v in pairs(src) do
      local field = fields_info[k]
      if not field then
        print("ERROR: field " .. tostring(k) .. " in message " .. tostring(c_type) .. " is unknown")
      end
      local lua2c = vpp.t_lua2c[field.c_type]
      -- print("__MSG__ field " .. tostring(k) .. " : " .. vpp.dump(field))
      -- if the field is not an array type, try to coerce the argument to a number
      if not field.array and type(v) == "string" then
        v = tonumber(v)
      end
      if not lua2c then
        print("__MSG__ " .. tostring(c_type) .. " t_lua2c: can not store field " .. field.name ..
              " type " .. field.c_type .. " dst " .. tostring(dst[k]))
        return 0
      end
      local len = 0
      local val = nil
      if field.array and (type(v) == "table") then
        -- print("NTFY: field " .. tostring(k) .. " in message " .. tostring(c_type) .. " is an array")
        for field_i, field_v in ipairs(v) do
          -- print("NTFY: setting member#" .. tostring(field_i) .. " to value " .. vpp.dump(field_v))
          local field_len, field_val = lua2c(field.c_type, field_v, dst[k][field_i-1])
          len = len + field_len
        end
      else
        len, val = lua2c(field.c_type, v, dst[k])
      end
      if not field.array then
        dst[k] = val
      else
        if 0 == field.array then
          additional_len = additional_len + len
          -- print("Adding " .. tostring(len) .. " bytes due to field " .. tostring(field.name))
          -- If there is a variable storing the length
          -- and the input table does not set it, do magic
          if field.array_size and not src[field.array_size] then
            local size_field = fields_info[field.array_size]
            if size_field then
              dst[field.array_size] = vpp.t_c2lua[size_field.c_type](size_field.c_type, len)
            end
          end
        end
      end
      -- print("Full message:\n" .. vpp.hex_dump(ffi.string(ffi.cast('void *', req_store_cache), 64)))
    end
    return (ffi.sizeof(dst[0])+additional_len)
  end

  vpp.t_c2lua["__MSG__"] = function(c_type, src_ptr, src_len)
    local out = {}
    local reply_typed_ptr = ffi.cast(c_type .. " *", src_ptr)
    local field_desc = vpp.c_type_to_fields[c_type]
    if src_len then
      for i = 0,src_len-1 do
        out[i+1] = vpp.t_c2lua[c_type](c_type, src_ptr[i])
      end
      return out
    end

    for k, v in pairs(field_desc) do
      local v_c2lua = vpp.t_c2lua[v.c_type]
      if v_c2lua then
        local len = v.array
        -- print(dump(v))
        if len then
          local len_field_name = k .. "_length"
          local len_field = field_desc[len_field_name]
          if (len_field) then
            local real_len = vpp.t_c2lua[len_field.c_type](len_field.c_type, reply_typed_ptr[len_field_name])
            out[k] =  v_c2lua(v.c_type, reply_typed_ptr[k], real_len)
          elseif len == 0 then
            -- check if len = 0, then must be a field which contains the size
            len_field =  field_desc[v.array_size]
            local real_len = vpp.t_c2lua[len_field.c_type](len_field.c_type, reply_typed_ptr[v.array_size])
            -- print("REAL length: " .. vpp.dump(v) .. " : " .. tostring(real_len))
            out[k] = v_c2lua(v.c_type, reply_typed_ptr[k], real_len)
          else
            -- alas, just stuff the entire array
            out[k] = v_c2lua(v.c_type, reply_typed_ptr[k], len)
          end
        else
          out[k] =  v_c2lua(v.c_type, reply_typed_ptr[k])
        end
      else
        out[k] = "<no accessor function for type " .. tostring(v.c_type) .. ">"
      end
      -- print(k, out[k])
    end
    return out
  end

  return vpp
end

function vpp.resolve_message_number(msgname)
  local name = msgname .. "_" .. vpp.msg_name_to_crc[msgname]
  local idx = vpp.pneum.pneum_get_msg_index(vpp.c_str(name))
  if vpp.debug_dump then
    print("Index for " .. tostring(name) .. " is " .. tostring(idx))
  end
  vpp.msg_name_to_number[msgname] = idx
  vpp.msg_number_to_name[idx] = msgname
  vpp.msg_number_to_type[idx] = "vl_api_" .. msgname .. "_t"
  vpp.msg_number_to_pointer_type[idx] = vpp.msg_number_to_type[idx] .. " *"
  ffi.cdef("\n\n enum { vl_msg_" .. msgname .. " = " .. idx .. " };\n\n")
end

function vpp.connect(vpp, client_name)
    local name = "lua_client"
    if client_name then
      name = client_name
    end
    local ret = vpp.pneum.pneum_connect(vpp.c_str(client_name), nil, nil)
    if tonumber(ret) == 0 then
      vpp.is_connected = true
    end
    for k, v in pairs(vpp.msg_name_to_number) do
      vpp.resolve_message_number(k)
    end
  end

function vpp.disconnect(vpp)
    vpp.pneum.pneum_disconnect()
  end

function vpp.json_api(vpp, path, plugin_name)
    -- print("Consuming the VPP api from "..path)
    local ffii = {}
    local f = io.open(path, "r")
    if not f then
      print("Could not open " .. path)
      return nil
    end
    local data = f:read("*all")
    local json = json.parse(data)
    if not (json.types or json.messages) then
      print("Can not parse " .. path)
      return nil
    end

    local all_types = {}

    for i, v in ipairs(json.types) do
      table.insert(all_types, { typeonly = 1, desc = v })
    end
    for i, v in ipairs(json.messages) do
      table.insert(all_types, { typeonly = 0, desc = v })
    end
    for i, v in ipairs(all_types) do
      local typeonly = v.typeonly
      local name = v.desc[1]
      local c_type = "vl_api_" .. name .. "_t"

      local fields = {}
      -- vpp.msg_name_to_fields[name] = fields
      -- print("CTYPE " .. c_type)
      vpp.c_type_to_fields[c_type] = fields
      vpp.t_lua2c[c_type] = vpp.t_lua2c["__MSG__"]
      vpp.t_c2lua[c_type] = vpp.t_c2lua["__MSG__"]

      local cdef = { "\n\n#pragma pack(1)\ntypedef struct _vl_api_", name, " {\n" }
      for ii, vv in ipairs(v.desc) do
        if type(vv) == "table" then
          if vv.crc then
            vpp.msg_name_to_crc[name] = string.sub(vv.crc, 3) -- strip the leading 0x
          else
            local fieldtype = vv[1]
            local fieldname = vv[2]
            local fieldcount = vv[3]
            local fieldcountvar = vv[4]
            local fieldrec = { name = fieldname, c_type = fieldtype, array = fieldcount, array_size = fieldcountvar }
            if fieldcount then
              table.insert(cdef, "  " .. fieldtype .. " " .. fieldname .. "[" .. fieldcount .. "];\n")
              if fieldtype == "u8" then
                -- any array of bytes is treated as a string
              elseif vpp.t_lua2c[fieldtype] then
                -- print("Array of " .. fieldtype .. " is ok!")
              else
                print("Unknown array type: ", name,  " : " , fieldname, " : ", fieldtype, ":", fieldcount, ":", fieldcountvar)
              end
            else
              table.insert(cdef, "  " .. fieldtype .. " " .. fieldname .. ";\n")
            end
            fields[fieldname] = fieldrec
          end
        end
      end

      table.insert(cdef, "} vl_api_" .. name .. "_t;")
      table.insert(ffii, table.concat(cdef))

      if typeonly == 0 then
        -- we will want to resolve this later
        if vpp.debug_dump then
          print("Remember to resolve " .. name)
        end
        vpp.msg_name_to_number[name] = -1
        if vpp.is_connected then
          vpp.resolve_message_number(name)
        end
      end

    end
    local cdef_full = table.concat(ffii)
    ffi.cdef(cdef_full)
end

function vpp.consume_api(vpp, path, plugin_name)
    -- print("Consuming the VPP api from "..path)
    local ffii = {}
    local f = io.open(path, "r")
    if not f then
      print("Could not open " .. path)
      return nil
    end
    local data = f:read("*all")
    -- Remove all C comments
    data = data:gsub("/%*.-%*/", "")
    if vpp.is_connected and not plugin_name then
      print(path .. ": must specify plugin name!")
      return
    end
    if plugin_name then
      vpp.plugin_version[plugin_name] = vpp.crc_version_string(data)
      local full_plugin_name = plugin_name .. "_" .. vpp.plugin_version[plugin_name]
      local reply = vpp:api_call("get_first_msg_id", { name = full_plugin_name } )
      vpp.next_msg_num = tonumber(reply[1].first_msg_id)
      print("Plugin " .. full_plugin_name .. " first message is " .. tostring(vpp.next_msg_num))
    end
    -- print ("data len: ", #data)
    data = data:gsub("\n(.-)(%S+)%s*{([^}]*)}", function (preamble, name, members)
      local _, typeonly = preamble:gsub("typeonly", "")
      local maybe_msg_id_field = { [0] = "u16 _vl_msg_id;", "" }
      local onedef = "\n\n#pragma pack(1)\ntypedef struct _vl_api_"..name.. " {\n" ..
	   -- "   u16 _vl_msg_id;" ..
           maybe_msg_id_field[typeonly] ..
	   members:gsub("%[[a-zA-Z_]+]", "[0]") ..
	   "} vl_api_" .. name .. "_t;"

      local c_type = "vl_api_" .. name .. "_t"

      local fields = {}
      -- vpp.msg_name_to_fields[name] = fields
      -- print("CTYPE " .. c_type)
      vpp.c_type_to_fields[c_type] = fields
      vpp.t_lua2c[c_type] = vpp.t_lua2c["__MSG__"]
      vpp.t_c2lua[c_type] = vpp.t_c2lua["__MSG__"]
      local mirec = { name = "_vl_msg_id", c_type = "u16", array = nil, array_size = nil }
      if typeonly == 0 then
        fields[mirec.name] = mirec
      end

      -- populate the field reflection table for the message
      -- sets the various type information as well as the accessors for lua<->C conversion
      members:gsub("(%S+)%s+(%S+);", function (fieldtype, fieldname)
          local fieldcount = nil
          local fieldcountvar = nil
          -- data = data:gsub("%[[a-zA-Z_]+]", "[0]")
          fieldname = fieldname:gsub("(%b[])", function(cnt)
              fieldcount = tonumber(cnt:sub(2, -2));
              if not fieldcount then
                fieldcount = 0
                fieldcountvar = cnt:sub(2, -2)
              end
              return ""
            end)
	  local fieldrec = { name = fieldname, c_type = fieldtype, array = fieldcount, array_size = fieldcountvar }
          if fieldcount then
            if fieldtype == "u8" then
              -- any array of bytes is treated as a string
            elseif vpp.t_lua2c[fieldtype] then
              -- print("Array of " .. fieldtype .. " is ok!")
            else
              print("Unknown array type: ", name,  " : " , fieldname, " : ", fieldtype, ":", fieldcount, ":", fieldcountvar)
            end
          end
	  fields[fieldname] = fieldrec
	end)

      -- print(dump(fields))

      if typeonly == 0 then
	local this_message_number = vpp.next_msg_num
	vpp.next_msg_num = vpp.next_msg_num + 1
	vpp.msg_name_to_number[name] = this_message_number
	vpp.msg_number_to_name[this_message_number] = name
	vpp.msg_number_to_type[this_message_number] = "vl_api_" .. name .. "_t"
	vpp.msg_number_to_pointer_type[this_message_number] = vpp.msg_number_to_type[this_message_number] .. " *"
	onedef = onedef .. "\n\n enum { vl_msg_" .. name .. " = " .. this_message_number .. " };\n\n"
      end
      table.insert(ffii, onedef);
      return "";
      end)
    local cdef = table.concat(ffii)
    -- print(cdef)
    ffi.cdef(cdef)
  end


function vpp.lua2c(vpp, c_type, src, dst_c_ptr)
  -- returns the number of bytes written to memory pointed by dst
  local lua2c = vpp.t_lua2c[c_type]
  if lua2c then
    return(lua2c(c_type, src, dst_c_ptr))
  else
    print("vpp.lua2c: do not know how to store type " .. tostring(c_type))
    local x = "a" .. nil
    return 0
  end
end

function vpp.c2lua(vpp, c_type, src_ptr, src_len)
  -- returns the lua data structure
  local c2lua = vpp.t_c2lua[c_type]
  if c2lua then
    return(c2lua(c_type, src_ptr, src_len))
  else
    print("vpp.c2lua: do not know how to load type " .. c_type)
    return nil
  end
end

local req_store_cache = ffi.new("vl_api_opaque_message_t[1]")

function vpp.api_write(vpp, api_name, req_table)
    local msg_num = vpp.msg_name_to_number[api_name]
    if not msg_num then
      print ("API call "..api_name.." is not known")
      return nil
    end

    if not req_table then
      req_table = {}
    end
    req_table._vl_msg_id = msg_num

    local packed_len = vpp:lua2c(vpp.msg_number_to_type[msg_num], req_table, req_store_cache)
    if vpp.debug_dump then
      print("Write Message length: " .. tostring(packed_len) .. "\n" .. vpp.hex_dump(ffi.string(ffi.cast('void *', req_store_cache), packed_len)))
    end

    res = vpp.pneum.pneum_write(ffi.cast('void *', req_store_cache), packed_len)
    return res
  end

local rep_store_cache = ffi.new("vl_api_opaque_message_t *[1]")
local rep_len_cache = ffi.new("int[1]")

function vpp.api_read(vpp)
    local rep_type = "vl_api_opaque_message_t"
    local rep = rep_store_cache
    local replen = rep_len_cache
    res = vpp.pneum.pneum_read(ffi.cast("void *", rep), replen)
    if vpp.debug_dump then
      print("Read Message length: " .. tostring(replen[0]) .. "\n" .. vpp.hex_dump(ffi.string(ffi.cast('void *', rep[0]), replen[0])))
    end

    local reply_msg_num = ffi.C.ntohs(rep[0]._vl_msg_id)
    local reply_msg_name = vpp.msg_number_to_name[reply_msg_num]

    local reply_typed_ptr = ffi.cast(vpp.msg_number_to_pointer_type[reply_msg_num], rep[0])
    local out = vpp:c2lua(vpp.msg_number_to_type[reply_msg_num], rep[0], nil, replen[0])
    if type(out) == "table" then
      out["luaapi_message_name"] = reply_msg_name
    end

    vpp.pneum.pneum_free(ffi.cast('void *',rep[0]))

    return reply_msg_name, out
  end

function vpp.api_call(vpp, api_name, req_table, options_in)
    local msg_num = vpp.msg_name_to_number[api_name]
    local end_message_name = api_name .."_reply"
    local replies = {}
    local cstruct = ""
    local options = options_in or {}
    if msg_num then
      if vpp.debug_dump then
        print("Message #" .. tostring(msg_num) .. " for name " .. tostring(api_name))
      end
      vpp:api_write(api_name, req_table)
      if not vpp.msg_name_to_number[end_message_name] or options.force_ping then
        end_message_name = "control_ping_reply"
        vpp:api_write("control_ping")
      end
      repeat
        reply_message_name, reply = vpp:api_read()
        if reply and not reply.context then
          -- there may be async events inbetween
          table.insert(vpp.events, reply)
        else
          if reply_message_name ~= "control_ping_reply" then
            -- do not insert the control ping encapsulation
            table.insert(replies, reply)
          end
        end
        -- print(reply)
      until reply_message_name == end_message_name
    else
      print(api_name .. " is an unknown API call")
      return nil
    end
    return replies
  end

return vpp