aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/drivers/common/zlib_drv.c
blob: 364048174ceda97e9bb5e6111bbebfec64e93cff (plain) (blame)
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
/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 2003-2013. All Rights Reserved.
 *
 * 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.
 *
 * %CopyrightEnd%
 */

/*
 * ZLib interface for erlang
 *
 */
#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif
#include <stdio.h>
#include <zlib.h>
#include <errno.h>
#include <string.h>

#include "erl_driver.h"


#define DEFLATE_INIT    1
#define DEFLATE_INIT2   2
#define DEFLATE_SETDICT 3
#define DEFLATE_RESET   4
#define DEFLATE_END     5
#define DEFLATE_PARAMS  6
#define DEFLATE         7

#define INFLATE_INIT    8
#define INFLATE_INIT2   9
#define INFLATE_SETDICT 10
#define INFLATE_SYNC    11
#define INFLATE_RESET   12
#define INFLATE_END     13
#define INFLATE         14

#define CRC32_0         15
#define CRC32_1         16
#define CRC32_2         17

#define SET_BUFSZ       18
#define GET_BUFSZ       19
#define GET_QSIZE       20

#define ADLER32_1       21
#define ADLER32_2       22

#define CRC32_COMBINE   23
#define ADLER32_COMBINE 24

#define INFLATE_CHUNK   25


#define DEFAULT_BUFSZ   4000

/* This flag is used in the same places, where zlib return codes
 * (Z_OK, Z_STREAM_END, Z_NEED_DICT) are. So, we need to set it to
 * relatively large value to avoid possible value clashes in future.
 * */
#define INFLATE_HAS_MORE 100

static int zlib_init(void);
static ErlDrvData zlib_start(ErlDrvPort port, char* buf);
static void zlib_stop(ErlDrvData e);
static void zlib_flush(ErlDrvData e);
static ErlDrvSSizeT zlib_ctl(ErlDrvData drv_data, unsigned int command, char *buf,
			     ErlDrvSizeT len, char **rbuf, ErlDrvSizeT rlen);
static void zlib_outputv(ErlDrvData drv_data, ErlIOVec *ev);

ErlDrvEntry zlib_driver_entry = {
    zlib_init,
    zlib_start,
    zlib_stop,
    NULL,                           /* output */
    NULL,                           /* ready_input */
    NULL,                           /* ready_output */
    "zlib_drv",
    NULL,                           /* finish */
    NULL,                           /* handle */
    zlib_ctl,
    NULL,                           /* timeout */
    zlib_outputv,
    NULL,                           /* read_async */
    zlib_flush,
    NULL,                           /* call */
    NULL,                           /* event */
    ERL_DRV_EXTENDED_MARKER,
    ERL_DRV_EXTENDED_MAJOR_VERSION,
    ERL_DRV_EXTENDED_MINOR_VERSION,
    ERL_DRV_FLAG_USE_PORT_LOCKING,
    NULL,                           /* handle2 */
    NULL,                           /* process_exit */
};

typedef enum {
    ST_NONE    = 0,
    ST_DEFLATE = 1,
    ST_INFLATE = 2
} ZLibState;


typedef struct {
    z_stream s;
    ZLibState state;
    ErlDrvBinary* bin;
    int binsz;
    int binsz_need;
    uLong crc;
    int inflate_eos_seen;
    int want_crc;       /* 1 if crc is calculated on clear text */
    ErlDrvPort port;    /* the associcated port */
} ZLibData;

static int zlib_inflate(ZLibData* d, int flush);
static int zlib_deflate(ZLibData* d, int flush);

#if defined(__WIN32__)
static int i32(char* buf)
#else
static __inline__ int i32(char* buf)
#endif
{
    return (int) (
		  (((int)((unsigned char*)buf)[0]) << 24) |
		  (((int)((unsigned char*)buf)[1]) << 16) |
		  (((int)((unsigned char*)buf)[2]) << 8) |
		  (((int)((unsigned char*)buf)[3]) << 0));
}

static char* zlib_reason(int code, int* err)
{
    switch(code) {
    case Z_OK:
	*err = 0;
	return "ok";
    case Z_STREAM_END:
	*err = 0;
	return "stream_end"; 
    case Z_ERRNO:
	*err = 1;
	return erl_errno_id(errno);
    case Z_STREAM_ERROR:
	*err = 1;
	return "stream_error";
    case Z_DATA_ERROR:
	*err = 1;
	return "data_error";
    case Z_MEM_ERROR:
	*err = 1;
	return "mem_error";
    case Z_BUF_ERROR:
	*err = 1;
	return "buf_error";
    case Z_VERSION_ERROR:
	*err = 1;
	return "version_error";
    default:
	*err = 1;
	return "unknown_error";
    }
}


static ErlDrvSSizeT zlib_return(int code, char** rbuf, ErlDrvSizeT rlen)
{
    int msg_code = 0; /* 0=ok, 1=error */
    char* dst = *rbuf;
    char* src;
    ErlDrvSizeT len = 0;

    src = zlib_reason(code, &msg_code);
    *dst++ = msg_code;
    rlen--;
    len = 1;

    while((rlen > 0) && *src) {
	*dst++ = *src++;
	rlen--;
	len++;
    }
    return len;
}

static ErlDrvSSizeT zlib_value2(int msg_code, int value,
				char** rbuf, ErlDrvSizeT rlen)
{
    char* dst = *rbuf;

    if (rlen  < 5) {
	return -1;
    }
    *dst++ = msg_code;
    *dst++ = (value >> 24) & 0xff;
    *dst++ = (value >> 16) & 0xff;
    *dst++ = (value >> 8) & 0xff;
    *dst++ = value & 0xff;
    return 5;
}

static ErlDrvSSizeT zlib_value(int value, char** rbuf, ErlDrvSizeT rlen)
{
    return zlib_value2(2, value, rbuf, rlen);
}

static int zlib_output_init(ZLibData* d)
{
    if (d->bin != NULL)
	driver_free_binary(d->bin);
    if ((d->bin = driver_alloc_binary(d->binsz_need)) == NULL)
	return -1;
    d->binsz = d->binsz_need;
    d->s.next_out = (unsigned char*)d->bin->orig_bytes;
    d->s.avail_out = d->binsz;
    return 0;
}

/*
 * Send compressed or uncompressed data
 * and restart output procesing
 */
static int zlib_output(ZLibData* d)
{
    if (d->bin != NULL) {
	int len = d->binsz - d->s.avail_out;
	if (len > 0) {
	    if (driver_output_binary(d->port, NULL, 0, d->bin, 0, len) < 0) 
		return -1;
	}
	driver_free_binary(d->bin);
	d->bin = NULL;
	d->binsz = 0;
    }
    return zlib_output_init(d);
}

static int zlib_inflate(ZLibData* d, int flush)
{
    int res = Z_OK;

    if ((d->bin == NULL) && (zlib_output_init(d) < 0)) {
	errno = ENOMEM;
	return Z_ERRNO;
    }

    while ((driver_sizeq(d->port) > 0) && (res != Z_STREAM_END)) {
	int vlen;
	SysIOVec* iov = driver_peekq(d->port, &vlen);
	int len;
	int possibly_more_output = 0;

	d->s.next_in = iov[0].iov_base;
	d->s.avail_in = iov[0].iov_len;
	while((possibly_more_output || (d->s.avail_in > 0)) && (res != Z_STREAM_END)) {
	    res = inflate(&d->s, Z_NO_FLUSH);
	    if (res == Z_NEED_DICT) {
		/* Essential to eat the header bytes that zlib has looked at */
		len = iov[0].iov_len - d->s.avail_in;
		driver_deq(d->port, len);
		return res;
	    }
	    if (res == Z_BUF_ERROR) {
		/* Was possible more output, but actually not */
		res = Z_OK;
	    }
	    else if (res < 0) {
		return res;
	    }
	    if (d->s.avail_out != 0) {
		possibly_more_output = 0;
	    } else {
		if (d->want_crc)
		    d->crc = crc32(d->crc, (unsigned char*)d->bin->orig_bytes,
				   d->binsz - d->s.avail_out);
		zlib_output(d);
		possibly_more_output = 1;
	    }
	}
	len = iov[0].iov_len - d->s.avail_in;
	driver_deq(d->port, len);
    }

    if (d->want_crc) {
       d->crc = crc32(d->crc, (unsigned char*) d->bin->orig_bytes,
		      d->binsz - d->s.avail_out);
    }
    zlib_output(d);
    if (res == Z_STREAM_END) {       
       d->inflate_eos_seen = 1;
    }
    return res;
}

static int zlib_inflate_chunk(ZLibData* d)
{
    int res = Z_OK;

    if ((d->bin == NULL) && (zlib_output_init(d) < 0)) {
	errno = ENOMEM;
	return Z_ERRNO;
    }

    while ((driver_sizeq(d->port) > 0) && (d->s.avail_out > 0) &&
           (res != Z_STREAM_END)) {
	int vlen;
	SysIOVec* iov = driver_peekq(d->port, &vlen);
	int len;

	d->s.next_in = iov[0].iov_base;
	d->s.avail_in = iov[0].iov_len;
	while((d->s.avail_in > 0) && (d->s.avail_out > 0) && (res != Z_STREAM_END)) {
	    res = inflate(&d->s, Z_NO_FLUSH);
	    if (res == Z_NEED_DICT) {
		/* Essential to eat the header bytes that zlib has looked at */
		len = iov[0].iov_len - d->s.avail_in;
		driver_deq(d->port, len);
		return res;
	    }
	    if (res == Z_BUF_ERROR) {
		/* Was possible more output, but actually not */
		res = Z_OK;
	    }
	    else if (res < 0) {
		return res;
	    }
	}
	len = iov[0].iov_len - d->s.avail_in;
	driver_deq(d->port, len);
    }

    /* We are here because all input was consumed or EOS reached or output
     * buffer is full */
    if (d->want_crc) {
       d->crc = crc32(d->crc, (unsigned char*) d->bin->orig_bytes,
		      d->binsz - d->s.avail_out);
    }
    zlib_output(d);
    if ((res == Z_OK) && (d->s.avail_in > 0))
       res = INFLATE_HAS_MORE;
    else if (res == Z_STREAM_END) {
       d->inflate_eos_seen = 1;
    }
    return res;
}

static int zlib_deflate(ZLibData* d, int flush)
{
    int res = Z_OK;

    if ((d->bin == NULL) && (zlib_output_init(d) < 0)) {
	errno = ENOMEM;
	return Z_ERRNO;
    }

    while ((driver_sizeq(d->port) > 0) && (res != Z_STREAM_END)) {
	int vlen;
	SysIOVec* iov = driver_peekq(d->port, &vlen);
	int len;

	d->s.next_in = iov[0].iov_base;
	d->s.avail_in = iov[0].iov_len;

	while((d->s.avail_in > 0) && (res != Z_STREAM_END)) {
	    if ((res = deflate(&d->s, Z_NO_FLUSH)) < 0) {
		return res;
	    }
	    if (d->s.avail_out == 0) {
		zlib_output(d);
	    }
	}
	len = iov[0].iov_len - d->s.avail_in;
	if (d->want_crc) {
	    d->crc = crc32(d->crc, iov[0].iov_base, len);
	}
	driver_deq(d->port, len);
    }

    if (flush != Z_NO_FLUSH) {
	if ((res = deflate(&d->s, flush)) < 0) {
	    return res;
	}
	if (flush == Z_FINISH) {
	    while (d->s.avail_out < d->binsz) {
		zlib_output(d);
		if (res == Z_STREAM_END) {
		    break;
		}
		if ((res = deflate(&d->s, flush)) < 0) {
		    return res;
		}
	    }
	} else {
	    while (d->s.avail_out == 0) {
	       zlib_output(d);
	       if ((res = deflate(&d->s, flush)) < 0) {
		  return res;
	       }
	    }
	    if (d->s.avail_out < d->binsz) {
	       zlib_output(d);
	    }
	}
    }
    return res;
}



static void* zlib_alloc(void* data, unsigned int items, unsigned int size)
{
    return (void*) driver_alloc(items*size);
}

static void zlib_free(void* data, void* addr)
{
    driver_free(addr);
}

static int zlib_init()
{
    return 0;
}

static ErlDrvData zlib_start(ErlDrvPort port, char* buf)
{
    ZLibData* d;

    if ((d = (ZLibData*) driver_alloc(sizeof(ZLibData))) == NULL)
        return ERL_DRV_ERROR_GENERAL;

    memset(&d->s, 0, sizeof(z_stream));

    d->s.zalloc = zlib_alloc;
    d->s.zfree  = zlib_free;
    d->s.opaque = d;
    d->s.data_type = Z_BINARY;

    d->port      = port;
    d->state     = ST_NONE;
    d->bin       = NULL;
    d->binsz     = 0;
    d->binsz_need = DEFAULT_BUFSZ;
    d->crc       = crc32(0L, Z_NULL, 0);
    d->inflate_eos_seen = 0;
    d->want_crc  = 0;
    return (ErlDrvData)d;
}


static void zlib_stop(ErlDrvData e)
{
    ZLibData* d = (ZLibData*)e;

    if (d->state == ST_DEFLATE)
	deflateEnd(&d->s);
    else if (d->state == ST_INFLATE)
	inflateEnd(&d->s);

    if (d->bin != NULL)
	driver_free_binary(d->bin);

    driver_free(d);
}

static void zlib_flush(ErlDrvData drv_data)
{
    ZLibData* d = (ZLibData*) drv_data;

    driver_deq(d->port, driver_sizeq(d->port));
}

static ErlDrvSSizeT zlib_ctl(ErlDrvData drv_data, unsigned int command, char *buf,
			     ErlDrvSizeT len, char **rbuf, ErlDrvSizeT rlen)
{
    ZLibData* d = (ZLibData*)drv_data;
    int res;

    switch(command) {
    case DEFLATE_INIT:
	if (len != 4) goto badarg;
	if (d->state != ST_NONE) goto badarg;
	res = deflateInit(&d->s, i32(buf));
	if (res == Z_OK) {
	    d->state = ST_DEFLATE;
	    d->want_crc = 0;
	    d->crc = crc32(0L, Z_NULL, 0);
	}
	return zlib_return(res, rbuf, rlen);

    case DEFLATE_INIT2: {
	int wbits;

	if (len != 20) goto badarg;
	if (d->state != ST_NONE) goto badarg;
	wbits = i32(buf+8);
	res = deflateInit2(&d->s, i32(buf), i32(buf+4), wbits, 
			   i32(buf+12), i32(buf+16));
	if (res == Z_OK) {
	    d->state = ST_DEFLATE;
	    d->want_crc = (wbits < 0);
	    d->crc = crc32(0L, Z_NULL, 0);
	}
	return zlib_return(res, rbuf, rlen);
    }
	
    case DEFLATE_SETDICT:
	if (d->state != ST_DEFLATE) goto badarg;
	res = deflateSetDictionary(&d->s, (unsigned char*)buf, len);
	if (res == Z_OK) {
	    return zlib_value(d->s.adler, rbuf, rlen);
	} else {
	    return zlib_return(res, rbuf, rlen);
	}

    case DEFLATE_RESET:
	if (len != 0) goto badarg;
	if (d->state != ST_DEFLATE) goto badarg;
	driver_deq(d->port, driver_sizeq(d->port));
	res = deflateReset(&d->s);
	return zlib_return(res, rbuf, rlen);	
	
    case DEFLATE_END:
	if (len != 0) goto badarg;
	if (d->state != ST_DEFLATE) goto badarg;
	driver_deq(d->port, driver_sizeq(d->port));
	res = deflateEnd(&d->s);
	d->state = ST_NONE;
	return zlib_return(res, rbuf, rlen);

    case DEFLATE_PARAMS:
	if (len != 8) goto badarg;
	if (d->state != ST_DEFLATE) goto badarg;
	res = deflateParams(&d->s, i32(buf), i32(buf+4));
	return zlib_return(res, rbuf, rlen);

    case DEFLATE:
	if (d->state != ST_DEFLATE) goto badarg;
	if (len != 4) goto badarg;
	res = zlib_deflate(d, i32(buf));
	return zlib_return(res, rbuf, rlen);

    case INFLATE_INIT:
	if (len != 0) goto badarg;
	if (d->state != ST_NONE) goto badarg;
	res = inflateInit(&d->s);
	if (res == Z_OK) {
	    d->state = ST_INFLATE;
	    d->inflate_eos_seen = 0;
	    d->want_crc = 0;
	    d->crc = crc32(0L, Z_NULL, 0);
	}
	return zlib_return(res, rbuf, rlen);	
	
    case INFLATE_INIT2: {
	int wbits;

	if (len != 4) goto badarg;	
	if (d->state != ST_NONE) goto badarg;
	wbits = i32(buf);
	res = inflateInit2(&d->s, wbits);
	if (res == Z_OK) {
	    d->state = ST_INFLATE;
	    d->inflate_eos_seen = 0;
	    d->want_crc = (wbits < 0);
	    d->crc = crc32(0L, Z_NULL, 0);
	}
	return zlib_return(res, rbuf, rlen);
    }
	
    case INFLATE_SETDICT:
	if (d->state != ST_INFLATE) goto badarg;
	res = inflateSetDictionary(&d->s, (unsigned char*)buf, len);
	return zlib_return(res, rbuf, rlen);

    case INFLATE_SYNC:
	if (d->state != ST_INFLATE) goto badarg;
	if (len != 0) goto badarg;
	if (driver_sizeq(d->port) == 0) {
	    res = Z_BUF_ERROR;
	} else {
	    int vlen;
	    SysIOVec* iov = driver_peekq(d->port, &vlen);

	    d->s.next_in = iov[0].iov_base;
	    d->s.avail_in = iov[0].iov_len;
	    res = inflateSync(&d->s);
	}
	return zlib_return(res, rbuf, rlen);

    case INFLATE_RESET:
	if (d->state != ST_INFLATE) goto badarg;
	if (len != 0) goto badarg;
	driver_deq(d->port, driver_sizeq(d->port));
	res = inflateReset(&d->s);
	d->inflate_eos_seen = 0;
	return zlib_return(res, rbuf, rlen);

    case INFLATE_END:
	if (d->state != ST_INFLATE) goto badarg;
	if (len != 0) goto badarg;
	driver_deq(d->port, driver_sizeq(d->port));
	res = inflateEnd(&d->s);
	if (res == Z_OK && d->inflate_eos_seen == 0) {
	    res = Z_DATA_ERROR;
	}
	d->state = ST_NONE;
	return zlib_return(res, rbuf, rlen);

    case INFLATE:
	if (d->state != ST_INFLATE) goto badarg;
	if (len != 4) goto badarg;
	res = zlib_inflate(d, i32(buf));
	if (res == Z_NEED_DICT) {
	    return zlib_value2(3, d->s.adler, rbuf, rlen);
	} else {
	    return zlib_return(res, rbuf, rlen);
	}

    case INFLATE_CHUNK:
	if (d->state != ST_INFLATE) goto badarg;
	if (len != 0) goto badarg;
	res = zlib_inflate_chunk(d);
	if (res == INFLATE_HAS_MORE) {
	    return zlib_value2(4, 0, rbuf, rlen);
	} else if (res == Z_NEED_DICT) {
	    return zlib_value2(3, d->s.adler, rbuf, rlen);
	} else {
	    return zlib_return(res, rbuf, rlen);
	}

    case GET_QSIZE:
	return zlib_value(driver_sizeq(d->port), rbuf, rlen);

    case GET_BUFSZ:
	return zlib_value(d->binsz_need, rbuf, rlen);

    case SET_BUFSZ: {
	int need;
	if (len != 4) goto badarg;
	need = i32(buf);
	if ((need < 16) || (need > 0x00ffffff))
	    goto badarg;
	if (d->binsz_need != need) {
	    d->binsz_need = need;
	    if (d->bin != NULL) {
		if (d->s.avail_out == d->binsz) {
		    driver_free_binary(d->bin);
		    d->bin = NULL;
		    d->binsz = 0;
		}
		else
		    zlib_output(d);
	    }
	}
	return zlib_return(Z_OK, rbuf, rlen);
    }

    case CRC32_0:
	return zlib_value(d->crc, rbuf, rlen);

    case CRC32_1: {
	uLong crc = crc32(0L, Z_NULL, 0);
	crc = crc32(crc, (unsigned char*) buf, len);
	return zlib_value(crc, rbuf, rlen);
    }
	
    case CRC32_2: {
	uLong crc;
	if (len < 4) goto badarg;
	crc = (unsigned int) i32(buf);
	crc = crc32(crc, (unsigned char*) buf+4, len-4);
	return zlib_value(crc, rbuf, rlen);
    }

    case ADLER32_1: {
	uLong adler = adler32(0L, Z_NULL, 0);
	adler = adler32(adler, (unsigned char*) buf, len);
	return zlib_value(adler, rbuf, rlen);
    }
	
    case ADLER32_2: {
       uLong adler;
       if (len < 4) goto badarg;
       adler = (unsigned int) i32(buf);
       adler = adler32(adler, (unsigned char*) buf+4, len-4);
       return zlib_value(adler, rbuf, rlen);
    }

    case CRC32_COMBINE: {
       uLong crc, crc1, crc2, len2;
       if (len != 12) goto badarg;
       crc1 = (unsigned int) i32(buf);
       crc2 = (unsigned int) i32(buf+4);
       len2 = (unsigned int) i32(buf+8);
       crc = crc32_combine(crc1, crc2, len2);
       return zlib_value(crc, rbuf, rlen);
    }

    case ADLER32_COMBINE: {
       uLong adler, adler1, adler2, len2;
       if (len != 12) goto badarg;
       adler1 = (unsigned int) i32(buf);
       adler2 = (unsigned int) i32(buf+4);
       len2   = (unsigned int) i32(buf+8);
       adler  = adler32_combine(adler1, adler2, len2);
       return zlib_value(adler, rbuf, rlen);
    }       
    }

 badarg:
    errno = EINVAL;
    return zlib_return(Z_ERRNO, rbuf, rlen);
}



static void zlib_outputv(ErlDrvData drv_data, ErlIOVec *ev)
{
    ZLibData* d = (ZLibData*) drv_data;

    driver_enqv(d->port, ev, 0);
}