summaryrefslogtreecommitdiff
path: root/src/scsi_id/scsi_serial.c
blob: c3f957db71042380f21fde1f06952e60b9c3da6b (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
/*
 * Copyright (C) IBM Corp. 2003
 *
 * Author: Patrick Mansfield<patmans@us.ibm.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <time.h>
#include <inttypes.h>
#include <scsi/scsi.h>
#include <scsi/sg.h>
#include <linux/types.h>
#include <linux/bsg.h>

#include "libudev.h"
#include "libudev-private.h"
#include "scsi.h"
#include "scsi_id.h"

/*
 * A priority based list of id, naa, and binary/ascii for the identifier
 * descriptor in VPD page 0x83.
 *
 * Brute force search for a match starting with the first value in the
 * following id_search_list. This is not a performance issue, since there
 * is normally one or some small number of descriptors.
 */
static const struct scsi_id_search_values id_search_list[] = {
        { SCSI_ID_TGTGROUP,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_BINARY },
        { SCSI_ID_NAA,        SCSI_ID_NAA_IEEE_REG_EXTENDED,        SCSI_ID_BINARY },
        { SCSI_ID_NAA,        SCSI_ID_NAA_IEEE_REG_EXTENDED,        SCSI_ID_ASCII },
        { SCSI_ID_NAA,        SCSI_ID_NAA_IEEE_REG,        SCSI_ID_BINARY },
        { SCSI_ID_NAA,        SCSI_ID_NAA_IEEE_REG,        SCSI_ID_ASCII },
        /*
         * Devices already exist using NAA values that are now marked
         * reserved. These should not conflict with other values, or it is
         * a bug in the device. As long as we find the IEEE extended one
         * first, we really don't care what other ones are used. Using
         * don't care here means that a device that returns multiple
         * non-IEEE descriptors in a random order will get different
         * names.
         */
        { SCSI_ID_NAA,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_BINARY },
        { SCSI_ID_NAA,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_ASCII },
        { SCSI_ID_EUI_64,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_BINARY },
        { SCSI_ID_EUI_64,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_ASCII },
        { SCSI_ID_T10_VENDOR,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_BINARY },
        { SCSI_ID_T10_VENDOR,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_ASCII },
        { SCSI_ID_VENDOR_SPECIFIC,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_BINARY },
        { SCSI_ID_VENDOR_SPECIFIC,        SCSI_ID_NAA_DONT_CARE,        SCSI_ID_ASCII },
};

static const char hex_str[]="0123456789abcdef";

/*
 * Values returned in the result/status, only the ones used by the code
 * are used here.
 */

#define DID_NO_CONNECT                        0x01        /* Unable to connect before timeout */
#define DID_BUS_BUSY                        0x02        /* Bus remain busy until timeout */
#define DID_TIME_OUT                        0x03        /* Timed out for some other reason */
#define DRIVER_TIMEOUT                        0x06
#define DRIVER_SENSE                        0x08        /* Sense_buffer has been set */

/* The following "category" function returns one of the following */
#define SG_ERR_CAT_CLEAN                0        /* No errors or other information */
#define SG_ERR_CAT_MEDIA_CHANGED        1        /* interpreted from sense buffer */
#define SG_ERR_CAT_RESET                2        /* interpreted from sense buffer */
#define SG_ERR_CAT_TIMEOUT                3
#define SG_ERR_CAT_RECOVERED                4        /* Successful command after recovered err */
#define SG_ERR_CAT_NOTSUPPORTED                5        /* Illegal / unsupported command */
#define SG_ERR_CAT_SENSE                98        /* Something else in the sense buffer */
#define SG_ERR_CAT_OTHER                99        /* Some other error/warning */

static int do_scsi_page80_inquiry(struct udev *udev,
                                  struct scsi_id_device *dev_scsi, int fd,
                                  char *serial, char *serial_short, int max_len);

static int sg_err_category_new(struct udev *udev,
                               int scsi_status, int msg_status, int
                               host_status, int driver_status, const
                               unsigned char *sense_buffer, int sb_len)
{
        scsi_status &= 0x7e;

        /*
         * XXX change to return only two values - failed or OK.
         */

        if (!scsi_status && !host_status && !driver_status)
                return SG_ERR_CAT_CLEAN;

        if ((scsi_status == SCSI_CHECK_CONDITION) ||
            (scsi_status == SCSI_COMMAND_TERMINATED) ||
            ((driver_status & 0xf) == DRIVER_SENSE)) {
                if (sense_buffer && (sb_len > 2)) {
                        int sense_key;
                        unsigned char asc;

                        if (sense_buffer[0] & 0x2) {
                                sense_key = sense_buffer[1] & 0xf;
                                asc = sense_buffer[2];
                        } else {
                                sense_key = sense_buffer[2] & 0xf;
                                asc = (sb_len > 12) ? sense_buffer[12] : 0;
                        }

                        if (sense_key == RECOVERED_ERROR)
                                return SG_ERR_CAT_RECOVERED;
                        else if (sense_key == UNIT_ATTENTION) {
                                if (0x28 == asc)
                                        return SG_ERR_CAT_MEDIA_CHANGED;
                                if (0x29 == asc)
                                        return SG_ERR_CAT_RESET;
                        } else if (sense_key == ILLEGAL_REQUEST) {
                                return SG_ERR_CAT_NOTSUPPORTED;
                        }
                }
                return SG_ERR_CAT_SENSE;
        }
        if (host_status) {
                if ((host_status == DID_NO_CONNECT) ||
                    (host_status == DID_BUS_BUSY) ||
                    (host_status == DID_TIME_OUT))
                        return SG_ERR_CAT_TIMEOUT;
        }
        if (driver_status) {
                if (driver_status == DRIVER_TIMEOUT)
                        return SG_ERR_CAT_TIMEOUT;
        }
        return SG_ERR_CAT_OTHER;
}

static int sg_err_category3(struct udev *udev, struct sg_io_hdr *hp)
{
        return sg_err_category_new(udev,
                                   hp->status, hp->msg_status,
                                   hp->host_status, hp->driver_status,
                                   hp->sbp, hp->sb_len_wr);
}

static int sg_err_category4(struct udev *udev, struct sg_io_v4 *hp)
{
        return sg_err_category_new(udev, hp->device_status, 0,
                                   hp->transport_status, hp->driver_status,
                                   (unsigned char *)(uintptr_t)hp->response,
                                   hp->response_len);
}

static int scsi_dump_sense(struct udev *udev,
                           struct scsi_id_device *dev_scsi,
                           unsigned char *sense_buffer, int sb_len)
{
        int s;
        int code;
        int sense_class;
        int sense_key;
        int asc, ascq;
#ifdef DUMP_SENSE
        char out_buffer[256];
        int i, j;
#endif

        /*
         * Figure out and print the sense key, asc and ascq.
         *
         * If you want to suppress these for a particular drive model, add
         * a black list entry in the scsi_id config file.
         *
         * XXX We probably need to: lookup the sense/asc/ascq in a retry
         * table, and if found return 1 (after dumping the sense, asc, and
         * ascq). So, if/when we get something like a power on/reset,
         * we'll retry the command.
         */

        if (sb_len < 1) {
                log_debug("%s: sense buffer empty", dev_scsi->kernel);
                return -1;
        }

        sense_class = (sense_buffer[0] >> 4) & 0x07;
        code = sense_buffer[0] & 0xf;

        if (sense_class == 7) {
                /*
                 * extended sense data.
                 */
                s = sense_buffer[7] + 8;
                if (sb_len < s) {
                        log_debug("%s: sense buffer too small %d bytes, %d bytes too short",
                            dev_scsi->kernel, sb_len, s - sb_len);
                        return -1;
                }
                if ((code == 0x0) || (code == 0x1)) {
                        sense_key = sense_buffer[2] & 0xf;
                        if (s < 14) {
                                /*
                                 * Possible?
                                 */
                                log_debug("%s: sense result too" " small %d bytes",
                                    dev_scsi->kernel, s);
                                return -1;
                        }
                        asc = sense_buffer[12];
                        ascq = sense_buffer[13];
                } else if ((code == 0x2) || (code == 0x3)) {
                        sense_key = sense_buffer[1] & 0xf;
                        asc = sense_buffer[2];
                        ascq = sense_buffer[3];
                } else {
                        log_debug("%s: invalid sense code 0x%x",
                            dev_scsi->kernel, code);
                        return -1;
                }
                log_debug("%s: sense key 0x%x ASC 0x%x ASCQ 0x%x",
                    dev_scsi->kernel, sense_key, asc, ascq);
        } else {
                if (sb_len < 4) {
                        log_debug("%s: sense buffer too small %d bytes, %d bytes too short",
                            dev_scsi->kernel, sb_len, 4 - sb_len);
                        return -1;
                }

                if (sense_buffer[0] < 15)
                        log_debug("%s: old sense key: 0x%x", dev_scsi->kernel, sense_buffer[0] & 0x0f);
                else
                        log_debug("%s: sense = %2x %2x",
                            dev_scsi->kernel, sense_buffer[0], sense_buffer[2]);
                log_debug("%s: non-extended sense class %d code 0x%0x",
                    dev_scsi->kernel, sense_class, code);

        }

#ifdef DUMP_SENSE
        for (i = 0, j = 0; (i < s) && (j < 254); i++) {
                out_buffer[j++] = hex_str[(sense_buffer[i] & 0xf0) >> 4];
                out_buffer[j++] = hex_str[sense_buffer[i] & 0x0f];
                out_buffer[j++] = ' ';
        }
        out_buffer[j] = '\0';
        log_debug("%s: sense dump:", dev_scsi->kernel);
        log_debug("%s: %s", dev_scsi->kernel, out_buffer);

#endif
        return -1;
}

static int scsi_dump(struct udev *udev,
                     struct scsi_id_device *dev_scsi, struct sg_io_hdr *io)
{
        if (!io->status && !io->host_status && !io->msg_status &&
            !io->driver_status) {
                /*
                 * Impossible, should not be called.
                 */
                log_debug("%s: called with no error", __FUNCTION__);
                return -1;
        }

        log_debug("%s: sg_io failed status 0x%x 0x%x 0x%x 0x%x",
            dev_scsi->kernel, io->driver_status, io->host_status, io->msg_status, io->status);
        if (io->status == SCSI_CHECK_CONDITION)
                return scsi_dump_sense(udev, dev_scsi, io->sbp, io->sb_len_wr);
        else
                return -1;
}

static int scsi_dump_v4(struct udev *udev,
                        struct scsi_id_device *dev_scsi, struct sg_io_v4 *io)
{
        if (!io->device_status && !io->transport_status &&
            !io->driver_status) {
                /*
                 * Impossible, should not be called.
                 */
                log_debug("%s: called with no error", __FUNCTION__);
                return -1;
        }

        log_debug("%s: sg_io failed status 0x%x 0x%x 0x%x",
            dev_scsi->kernel, io->driver_status, io->transport_status,
             io->device_status);
        if (io->device_status == SCSI_CHECK_CONDITION)
                return scsi_dump_sense(udev, dev_scsi, (unsigned char *)(uintptr_t)io->response,
                                       io->response_len);
        else
                return -1;
}

static int scsi_inquiry(struct udev *udev,
                        struct scsi_id_device *dev_scsi, int fd,
                        unsigned char evpd, unsigned char page,
                        unsigned char *buf, unsigned int buflen)
{
        unsigned char inq_cmd[INQUIRY_CMDLEN] =
                { INQUIRY_CMD, evpd, page, 0, buflen, 0 };
        unsigned char sense[SENSE_BUFF_LEN];
        void *io_buf;
        struct sg_io_v4 io_v4;
        struct sg_io_hdr io_hdr;
        int retry = 3; /* rather random */
        int retval;

        if (buflen > SCSI_INQ_BUFF_LEN) {
                log_debug("buflen %d too long", buflen);
                return -1;
        }

resend:
        if (dev_scsi->use_sg == 4) {
                memzero(&io_v4, sizeof(struct sg_io_v4));
                io_v4.guard = 'Q';
                io_v4.protocol = BSG_PROTOCOL_SCSI;
                io_v4.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
                io_v4.request_len = sizeof(inq_cmd);
                io_v4.request = (uintptr_t)inq_cmd;
                io_v4.max_response_len = sizeof(sense);
                io_v4.response = (uintptr_t)sense;
                io_v4.din_xfer_len = buflen;
                io_v4.din_xferp = (uintptr_t)buf;
                io_buf = (void *)&io_v4;
        } else {
                memzero(&io_hdr, sizeof(struct sg_io_hdr));
                io_hdr.interface_id = 'S';
                io_hdr.cmd_len = sizeof(inq_cmd);
                io_hdr.mx_sb_len = sizeof(sense);
                io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
                io_hdr.dxfer_len = buflen;
                io_hdr.dxferp = buf;
                io_hdr.cmdp = inq_cmd;
                io_hdr.sbp = sense;
                io_hdr.timeout = DEF_TIMEOUT;
                io_buf = (void *)&io_hdr;
        }

        retval = ioctl(fd, SG_IO, io_buf);
        if (retval < 0) {
                if ((errno == EINVAL || errno == ENOSYS) && dev_scsi->use_sg == 4) {
                        dev_scsi->use_sg = 3;
                        goto resend;
                }
                log_debug("%s: ioctl failed: %m", dev_scsi->kernel);
                goto error;
        }

        if (dev_scsi->use_sg == 4)
                retval = sg_err_category4(udev, io_buf);
        else
                retval = sg_err_category3(udev, io_buf);

        switch (retval) {
                case SG_ERR_CAT_NOTSUPPORTED:
                        buf[1] = 0;
                        /* Fallthrough */
                case SG_ERR_CAT_CLEAN:
                case SG_ERR_CAT_RECOVERED:
                        retval = 0;
                        break;

                default:
                        if (dev_scsi->use_sg == 4)
                                retval = scsi_dump_v4(udev, dev_scsi, io_buf);
                        else
                                retval = scsi_dump(udev, dev_scsi, io_buf);
        }

        if (!retval) {
                retval = buflen;
        } else if (retval > 0) {
                if (--retry > 0)
                        goto resend;
                retval = -1;
        }

error:
        if (retval < 0)
                log_debug("%s: Unable to get INQUIRY vpd %d page 0x%x.",
                    dev_scsi->kernel, evpd, page);

        return retval;
}

/* Get list of supported EVPD pages */
static int do_scsi_page0_inquiry(struct udev *udev,
                                 struct scsi_id_device *dev_scsi, int fd,
                                 unsigned char *buffer, unsigned int len)
{
        int retval;

        memzero(buffer, len);
        retval = scsi_inquiry(udev, dev_scsi, fd, 1, 0x0, buffer, len);
        if (retval < 0)
                return 1;

        if (buffer[1] != 0) {
                log_debug("%s: page 0 not available.", dev_scsi->kernel);
                return 1;
        }
        if (buffer[3] > len) {
                log_debug("%s: page 0 buffer too long %d", dev_scsi->kernel,         buffer[3]);
                return 1;
        }

        /*
         * Following check is based on code once included in the 2.5.x
         * kernel.
         *
         * Some ill behaved devices return the standard inquiry here
         * rather than the evpd data, snoop the data to verify.
         */
        if (buffer[3] > MODEL_LENGTH) {
                /*
                 * If the vendor id appears in the page assume the page is
                 * invalid.
                 */
                if (strneq((char *)&buffer[VENDOR_LENGTH], dev_scsi->vendor, VENDOR_LENGTH)) {
                        log_debug("%s: invalid page0 data", dev_scsi->kernel);
                        return 1;
                }
        }
        return 0;
}

/*
 * The caller checks that serial is long enough to include the vendor +
 * model.
 */
static int prepend_vendor_model(struct udev *udev,
                                struct scsi_id_device *dev_scsi, char *serial)
{
        int ind;

        strncpy(serial, dev_scsi->vendor, VENDOR_LENGTH);
        strncat(serial, dev_scsi->model, MODEL_LENGTH);
        ind = strlen(serial);

        /*
         * This is not a complete check, since we are using strncat/cpy
         * above, ind will never be too large.
         */
        if (ind != (VENDOR_LENGTH + MODEL_LENGTH)) {
                log_debug("%s: expected length %d, got length %d",
                     dev_scsi->kernel, (VENDOR_LENGTH + MODEL_LENGTH), ind);
                return -1;
        }
        return ind;
}

/*
 * check_fill_0x83_id - check the page 0x83 id, if OK allocate and fill
 * serial number.
 */
static int check_fill_0x83_id(struct udev *udev,
                              struct scsi_id_device *dev_scsi,
                              unsigned char *page_83,
                              const struct scsi_id_search_values
                              *id_search, char *serial, char *serial_short,
                              int max_len, char *wwn,
                              char *wwn_vendor_extension, char *tgpt_group)
{
        int i, j, s, len;

        /*
         * ASSOCIATION must be with the device (value 0)
         * or with the target port for SCSI_ID_TGTPORT
         */
        if ((page_83[1] & 0x30) == 0x10) {
                if (id_search->id_type != SCSI_ID_TGTGROUP)
                        return 1;
        } else if ((page_83[1] & 0x30) != 0) {
                return 1;
        }

        if ((page_83[1] & 0x0f) != id_search->id_type)
                return 1;

        /*
         * Possibly check NAA sub-type.
         */
        if ((id_search->naa_type != SCSI_ID_NAA_DONT_CARE) &&
            (id_search->naa_type != (page_83[4] & 0xf0) >> 4))
                return 1;

        /*
         * Check for matching code set - ASCII or BINARY.
         */
        if ((page_83[0] & 0x0f) != id_search->code_set)
                return 1;

        /*
         * page_83[3]: identifier length
         */
        len = page_83[3];
        if ((page_83[0] & 0x0f) != SCSI_ID_ASCII)
                /*
                 * If not ASCII, use two bytes for each binary value.
                 */
                len *= 2;

        /*
         * Add one byte for the NUL termination, and one for the id_type.
         */
        len += 2;
        if (id_search->id_type == SCSI_ID_VENDOR_SPECIFIC)
                len += VENDOR_LENGTH + MODEL_LENGTH;

        if (max_len < len) {
                log_debug("%s: length %d too short - need %d",
                    dev_scsi->kernel, max_len, len);
                return 1;
        }

        if (id_search->id_type == SCSI_ID_TGTGROUP && tgpt_group != NULL) {
                unsigned int group;

                group = ((unsigned int)page_83[6] << 8) | page_83[7];
                sprintf(tgpt_group,"%x", group);
                return 1;
        }

        serial[0] = hex_str[id_search->id_type];

        /*
         * For SCSI_ID_VENDOR_SPECIFIC prepend the vendor and model before
         * the id since it is not unique across all vendors and models,
         * this differs from SCSI_ID_T10_VENDOR, where the vendor is
         * included in the identifier.
         */
        if (id_search->id_type == SCSI_ID_VENDOR_SPECIFIC)
                if (prepend_vendor_model(udev, dev_scsi, &serial[1]) < 0)
                        return 1;

        i = 4; /* offset to the start of the identifier */
        s = j = strlen(serial);
        if ((page_83[0] & 0x0f) == SCSI_ID_ASCII) {
                /*
                 * ASCII descriptor.
                 */
                while (i < (4 + page_83[3]))
                        serial[j++] = page_83[i++];
        } else {
                /*
                 * Binary descriptor, convert to ASCII, using two bytes of
                 * ASCII for each byte in the page_83.
                 */
                while (i < (4 + page_83[3])) {
                        serial[j++] = hex_str[(page_83[i] & 0xf0) >> 4];
                        serial[j++] = hex_str[page_83[i] & 0x0f];
                        i++;
                }
        }

        strcpy(serial_short, &serial[s]);

        if (id_search->id_type == SCSI_ID_NAA && wwn != NULL) {
                strncpy(wwn, &serial[s], 16);
                if (wwn_vendor_extension != NULL) {
                        strncpy(wwn_vendor_extension, &serial[s + 16], 16);
                }
        }

        return 0;
}

/* Extract the raw binary from VPD 0x83 pre-SPC devices */
static int check_fill_0x83_prespc3(struct udev *udev,
                                   struct scsi_id_device *dev_scsi,
                                   unsigned char *page_83,
                                   const struct scsi_id_search_values
                                   *id_search, char *serial, char *serial_short, int max_len)
{
        int i, j;

        serial[0] = hex_str[id_search->id_type];
        /* serial has been memset to zero before */
        j = strlen(serial);        /* j = 1; */

        for (i = 0; (i < page_83[3]) && (j < max_len-3); ++i) {
                serial[j++] = hex_str[(page_83[4+i] & 0xf0) >> 4];
                serial[j++] = hex_str[ page_83[4+i] & 0x0f];
        }
        serial[max_len-1] = 0;
        strncpy(serial_short, serial, max_len-1);
        return 0;
}


/* Get device identification VPD page */
static int do_scsi_page83_inquiry(struct udev *udev,
                                  struct scsi_id_device *dev_scsi, int fd,
                                  char *serial, char *serial_short, int len,
                                  char *unit_serial_number, char *wwn,
                                  char *wwn_vendor_extension, char *tgpt_group)
{
        int retval;
        unsigned int id_ind, j;
        unsigned char page_83[SCSI_INQ_BUFF_LEN];

        /* also pick up the page 80 serial number */
        do_scsi_page80_inquiry(udev, dev_scsi, fd, NULL, unit_serial_number, MAX_SERIAL_LEN);

        memzero(page_83, SCSI_INQ_BUFF_LEN);
        retval = scsi_inquiry(udev, dev_scsi, fd, 1, PAGE_83, page_83,
                              SCSI_INQ_BUFF_LEN);
        if (retval < 0)
                return 1;

        if (page_83[1] != PAGE_83) {
                log_debug("%s: Invalid page 0x83", dev_scsi->kernel);
                return 1;
        }

        /*
         * XXX Some devices (IBM 3542) return all spaces for an identifier if
         * the LUN is not actually configured. This leads to identifiers of
         * the form: "1            ".
         */

        /*
         * Model 4, 5, and (some) model 6 EMC Symmetrix devices return
         * a page 83 reply according to SCSI-2 format instead of SPC-2/3.
         *
         * The SCSI-2 page 83 format returns an IEEE WWN in binary
         * encoded hexi-decimal in the 16 bytes following the initial
         * 4-byte page 83 reply header.
         *
         * Both the SPC-2 and SPC-3 formats return an IEEE WWN as part
         * of an Identification descriptor.  The 3rd byte of the first
         * Identification descriptor is a reserved (BSZ) byte field.
         *
         * Reference the 7th byte of the page 83 reply to determine
         * whether the reply is compliant with SCSI-2 or SPC-2/3
         * specifications.  A zero value in the 7th byte indicates
         * an SPC-2/3 conformant reply, (i.e., the reserved field of the
         * first Identification descriptor).  This byte will be non-zero
         * for a SCSI-2 conformant page 83 reply from these EMC
         * Symmetrix models since the 7th byte of the reply corresponds
         * to the 4th and 5th nibbles of the 6-byte OUI for EMC, that is,
         * 0x006048.
         */

        if (page_83[6] != 0)
                return check_fill_0x83_prespc3(udev,
                                               dev_scsi, page_83, id_search_list,
                                               serial, serial_short, len);

        /*
         * Search for a match in the prioritized id_search_list - since WWN ids
         * come first we can pick up the WWN in check_fill_0x83_id().
         */
        for (id_ind = 0;
             id_ind < sizeof(id_search_list)/sizeof(id_search_list[0]);
             id_ind++) {
                /*
                 * Examine each descriptor returned. There is normally only
                 * one or a small number of descriptors.
                 */
                for (j = 4; j <= (unsigned int)page_83[3] + 3; j += page_83[j + 3] + 4) {
                        retval = check_fill_0x83_id(udev,
                                                    dev_scsi, &page_83[j],
                                                    &id_search_list[id_ind],
                                                    serial, serial_short, len,
                                                    wwn, wwn_vendor_extension,
                                                    tgpt_group);
                        if (!retval)
                                return retval;
                        else if (retval < 0)
                                return retval;
                }
        }
        return 1;
}

/*
 * Get device identification VPD page for older SCSI-2 device which is not
 * compliant with either SPC-2 or SPC-3 format.
 *
 * Return the hard coded error code value 2 if the page 83 reply is not
 * conformant to the SCSI-2 format.
 */
static int do_scsi_page83_prespc3_inquiry(struct udev *udev,
                                          struct scsi_id_device *dev_scsi, int fd,
                                          char *serial, char *serial_short, int len)
{
        int retval;
        int i, j;
        unsigned char page_83[SCSI_INQ_BUFF_LEN];

        memzero(page_83, SCSI_INQ_BUFF_LEN);
        retval = scsi_inquiry(udev, dev_scsi, fd, 1, PAGE_83, page_83, SCSI_INQ_BUFF_LEN);
        if (retval < 0)
                return 1;

        if (page_83[1] != PAGE_83) {
                log_debug("%s: Invalid page 0x83", dev_scsi->kernel);
                return 1;
        }
        /*
         * Model 4, 5, and (some) model 6 EMC Symmetrix devices return
         * a page 83 reply according to SCSI-2 format instead of SPC-2/3.
         *
         * The SCSI-2 page 83 format returns an IEEE WWN in binary
         * encoded hexi-decimal in the 16 bytes following the initial
         * 4-byte page 83 reply header.
         *
         * Both the SPC-2 and SPC-3 formats return an IEEE WWN as part
         * of an Identification descriptor.  The 3rd byte of the first
         * Identification descriptor is a reserved (BSZ) byte field.
         *
         * Reference the 7th byte of the page 83 reply to determine
         * whether the reply is compliant with SCSI-2 or SPC-2/3
         * specifications.  A zero value in the 7th byte indicates
         * an SPC-2/3 conformant reply, (i.e., the reserved field of the
         * first Identification descriptor).  This byte will be non-zero
         * for a SCSI-2 conformant page 83 reply from these EMC
         * Symmetrix models since the 7th byte of the reply corresponds
         * to the 4th and 5th nibbles of the 6-byte OUI for EMC, that is,
         * 0x006048.
         */
        if (page_83[6] == 0)
                return 2;

        serial[0] = hex_str[id_search_list[0].id_type];
        /*
         * The first four bytes contain data, not a descriptor.
         */
        i = 4;
        j = strlen(serial);
        /*
         * Binary descriptor, convert to ASCII,
         * using two bytes of ASCII for each byte
         * in the page_83.
         */
        while (i < (page_83[3]+4)) {
                serial[j++] = hex_str[(page_83[i] & 0xf0) >> 4];
                serial[j++] = hex_str[page_83[i] & 0x0f];
                i++;
        }
        return 0;
}

/* Get unit serial number VPD page */
static int do_scsi_page80_inquiry(struct udev *udev,
                                  struct scsi_id_device *dev_scsi, int fd,
                                  char *serial, char *serial_short, int max_len)
{
        int retval;
        int ser_ind;
        int i;
        int len;
        unsigned char buf[SCSI_INQ_BUFF_LEN];

        memzero(buf, SCSI_INQ_BUFF_LEN);
        retval = scsi_inquiry(udev, dev_scsi, fd, 1, PAGE_80, buf, SCSI_INQ_BUFF_LEN);
        if (retval < 0)
                return retval;

        if (buf[1] != PAGE_80) {
                log_debug("%s: Invalid page 0x80", dev_scsi->kernel);
                return 1;
        }

        len = 1 + VENDOR_LENGTH + MODEL_LENGTH + buf[3];
        if (max_len < len) {
                log_debug("%s: length %d too short - need %d",
                     dev_scsi->kernel, max_len, len);
                return 1;
        }
        /*
         * Prepend 'S' to avoid unlikely collision with page 0x83 vendor
         * specific type where we prepend '0' + vendor + model.
         */
        len = buf[3];
        if (serial != NULL) {
                serial[0] = 'S';
                ser_ind = prepend_vendor_model(udev, dev_scsi, &serial[1]);
                if (ser_ind < 0)
                        return 1;
                ser_ind++; /* for the leading 'S' */
                for (i = 4; i < len + 4; i++, ser_ind++)
                        serial[ser_ind] = buf[i];
        }
        if (serial_short != NULL) {
                memcpy(serial_short, &buf[4], len);
                serial_short[len] = '\0';
        }
        return 0;
}

int scsi_std_inquiry(struct udev *udev,
                     struct scsi_id_device *dev_scsi, const char *devname)
{
        int fd;
        unsigned char buf[SCSI_INQ_BUFF_LEN];
        struct stat statbuf;
        int err = 0;

        fd = open(devname, O_RDONLY | O_NONBLOCK | O_CLOEXEC);
        if (fd < 0) {
                log_debug("scsi_id: cannot open %s: %m", devname);
                return 1;
        }

        if (fstat(fd, &statbuf) < 0) {
                log_debug("scsi_id: cannot stat %s: %m", devname);
                err = 2;
                goto out;
        }
        sprintf(dev_scsi->kernel,"%d:%d", major(statbuf.st_rdev),
                minor(statbuf.st_rdev));

        memzero(buf, SCSI_INQ_BUFF_LEN);
        err = scsi_inquiry(udev, dev_scsi, fd, 0, 0, buf, SCSI_INQ_BUFF_LEN);
        if (err < 0)
                goto out;

        err = 0;
        memcpy(dev_scsi->vendor, buf + 8, 8);
        dev_scsi->vendor[8] = '\0';
        memcpy(dev_scsi->model, buf + 16, 16);
        dev_scsi->model[16] = '\0';
        memcpy(dev_scsi->revision, buf + 32, 4);
        dev_scsi->revision[4] = '\0';
        sprintf(dev_scsi->type,"%x", buf[0] & 0x1f);

out:
        close(fd);
        return err;
}

int scsi_get_serial(struct udev *udev,
                    struct scsi_id_device *dev_scsi, const char *devname,
                    int page_code, int len)
{
        unsigned char page0[SCSI_INQ_BUFF_LEN];
        int fd = -1;
        int cnt;
        int ind;
        int retval;

        memzero(dev_scsi->serial, len);
        srand((unsigned int)getpid());
        for (cnt = 20; cnt > 0; cnt--) {
                struct timespec duration;

                fd = open(devname, O_RDONLY | O_NONBLOCK | O_CLOEXEC);
                if (fd >= 0 || errno != EBUSY)
                        break;
                duration.tv_sec = 0;
                duration.tv_nsec = (200 * 1000 * 1000) + (rand() % 100 * 1000 * 1000);
                nanosleep(&duration, NULL);
        }
        if (fd < 0)
                return 1;

        if (page_code == PAGE_80) {
                if (do_scsi_page80_inquiry(udev, dev_scsi, fd, dev_scsi->serial, dev_scsi->serial_short, len)) {
                        retval = 1;
                        goto completed;
                } else  {
                        retval = 0;
                        goto completed;
                }
        } else if (page_code == PAGE_83) {
                if (do_scsi_page83_inquiry(udev, dev_scsi, fd, dev_scsi->serial, dev_scsi->serial_short, len, dev_scsi->unit_serial_number, dev_scsi->wwn, dev_scsi->wwn_vendor_extension, dev_scsi->tgpt_group)) {
                        retval = 1;
                        goto completed;
                } else  {
                        retval = 0;
                        goto completed;
                }
        } else if (page_code == PAGE_83_PRE_SPC3) {
                retval = do_scsi_page83_prespc3_inquiry(udev, dev_scsi, fd, dev_scsi->serial, dev_scsi->serial_short, len);
                if (retval) {
                        /*
                         * Fallback to servicing a SPC-2/3 compliant page 83
                         * inquiry if the page 83 reply format does not
                         * conform to pre-SPC3 expectations.
                         */
                        if (retval == 2) {
                                if (do_scsi_page83_inquiry(udev, dev_scsi, fd, dev_scsi->serial, dev_scsi->serial_short, len, dev_scsi->unit_serial_number, dev_scsi->wwn, dev_scsi->wwn_vendor_extension, dev_scsi->tgpt_group)) {
                                        retval = 1;
                                        goto completed;
                                } else  {
                                        retval = 0;
                                        goto completed;
                                }
                        }
                        else {
                                retval = 1;
                                goto completed;
                        }
                } else  {
                        retval = 0;
                        goto completed;
                }
        } else if (page_code != 0x00) {
                log_debug("%s: unsupported page code 0x%d", dev_scsi->kernel, page_code);
                retval = 1;
                goto completed;
        }

        /*
         * Get page 0, the page of the pages. By default, try from best to
         * worst of supported pages: 0x83 then 0x80.
         */
        if (do_scsi_page0_inquiry(udev, dev_scsi, fd, page0, SCSI_INQ_BUFF_LEN)) {
                /*
                 * Don't try anything else. Black list if a specific page
                 * should be used for this vendor+model, or maybe have an
                 * optional fall-back to page 0x80 or page 0x83.
                 */
                retval = 1;
                goto completed;
        }

        for (ind = 4; ind <= page0[3] + 3; ind++)
                if (page0[ind] == PAGE_83)
                        if (!do_scsi_page83_inquiry(udev, dev_scsi, fd,
                                                    dev_scsi->serial, dev_scsi->serial_short, len, dev_scsi->unit_serial_number, dev_scsi->wwn, dev_scsi->wwn_vendor_extension, dev_scsi->tgpt_group)) {
                                /*
                                 * Success
                                 */
                                retval = 0;
                                goto completed;
                        }

        for (ind = 4; ind <= page0[3] + 3; ind++)
                if (page0[ind] == PAGE_80)
                        if (!do_scsi_page80_inquiry(udev, dev_scsi, fd,
                                                    dev_scsi->serial, dev_scsi->serial_short, len)) {
                                /*
                                 * Success
                                 */
                                retval = 0;
                                goto completed;
                        }
        retval = 1;

completed:
        close(fd);
        return retval;
}