summaryrefslogtreecommitdiffstats
path: root/unix/tclUnixCompat.c
blob: 74b4bf38dfd2e1d4fc5191ec1c0b53cb80f39690 (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
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
/*
 * tclUnixCompat.c
 *
 * Written by: Zoran Vasiljevic (vasiljevic@users.sourceforge.net).
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclInt.h"
#include <pwd.h>
#include <grp.h>
#include <errno.h>
#include <string.h>

/*
 * See also: SC_BLOCKING_STYLE in unix/tcl.m4
 */

#ifdef	USE_FIONBIO
#   ifdef HAVE_SYS_FILIO_H
#	include	<sys/filio.h>	/* For FIONBIO. */
#   endif
#   ifdef HAVE_SYS_IOCTL_H
#	include	<sys/ioctl.h>
#   endif
#endif	/* USE_FIONBIO */

/*
 * Used to pad structures at size'd boundaries
 *
 * This macro assumes that the pointer 'buffer' was created from an aligned
 * pointer by adding the 'length'. If this 'length' was not a multiple of the
 * 'size' the result is unaligned and PadBuffer corrects both the pointer,
 * _and_ the 'length'. The latter means that future increments of 'buffer' by
 * 'length' stay aligned.
 */

#define PadBuffer(buffer, length, size)			\
    if (((length) % (size))) {				\
	(buffer) += ((size) - ((length) % (size)));	\
	(length) += ((size) - ((length) % (size)));	\
    }

/*
 * Per-thread private storage used to store values returned from MT-unsafe
 * library calls.
 */

#if TCL_THREADS

typedef struct {
    struct passwd pwd;
#if defined(HAVE_GETPWNAM_R_5) || defined(HAVE_GETPWUID_R_5)
#define NEED_PW_CLEANER 1
    char *pbuf;
    int pbuflen;
#else
    char pbuf[2048];
#endif

    struct group grp;
#if defined(HAVE_GETGRNAM_R_5) || defined(HAVE_GETGRGID_R_5)
#define NEED_GR_CLEANER 1
    char *gbuf;
    int gbuflen;
#else
    char gbuf[2048];
#endif

#if !defined(HAVE_MTSAFE_GETHOSTBYNAME) || !defined(HAVE_MTSAFE_GETHOSTBYADDR)
    struct hostent hent;
    char hbuf[2048];
#endif
}  ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;

#if ((!defined(HAVE_GETHOSTBYNAME_R) || !defined(HAVE_GETHOSTBYADDR_R)) && \
     (!defined(HAVE_MTSAFE_GETHOSTBYNAME) || \
      !defined(HAVE_MTSAFE_GETHOSTBYADDR))) || \
      !defined(HAVE_GETPWNAM_R) || !defined(HAVE_GETPWUID_R) || \
      !defined(HAVE_GETGRNAM_R) || !defined(HAVE_GETGRGID_R)
/*
 * Mutex to lock access to MT-unsafe calls. This is just to protect our own
 * usage. It does not protect us from others calling the same functions
 * without (or using some different) lock.
 */

static Tcl_Mutex compatLock;

/*
 * Helper function declarations. Note that these are only used if needed and
 * only defined if used (via the NEED_* macros).
 */

#undef NEED_COPYARRAY
#undef NEED_COPYGRP
#undef NEED_COPYHOSTENT
#undef NEED_COPYPWD
#undef NEED_COPYSTRING

#if !defined(HAVE_GETGRNAM_R_5) && !defined(HAVE_GETGRNAM_R_4)
#define NEED_COPYGRP 1
static int		CopyGrp(struct group *tgtPtr, char *buf, int buflen);
#endif

#if !defined(HAVE_GETPWNAM_R_5) && !defined(HAVE_GETPWNAM_R_4)
#define NEED_COPYPWD 1
static int		CopyPwd(struct passwd *tgtPtr, char *buf, int buflen);
#endif

static int		CopyArray(char **src, int elsize, char *buf,
			    int buflen);
static int		CopyHostent(struct hostent *tgtPtr, char *buf,
			    int buflen);
static int		CopyString(const char *src, char *buf, int buflen);

#endif

#ifdef NEED_PW_CLEANER
static void		FreePwBuf(ClientData dummy);
#endif
#ifdef NEED_GR_CLEANER
static void		FreeGrBuf(ClientData dummy);
#endif
#endif /* TCL_THREADS */

/*
 *---------------------------------------------------------------------------
 *
 * TclUnixSetBlockingMode --
 *
 *	Set the blocking mode of a file descriptor.
 *
 * Results:
 *
 *	0 on success, -1 (with errno set) on error.
 *
 *---------------------------------------------------------------------------
 */

int
TclUnixSetBlockingMode(
    int fd,			/* File descriptor */
    int mode)			/* Either TCL_MODE_BLOCKING or
				 * TCL_MODE_NONBLOCKING. */
{
#ifndef USE_FIONBIO
    int flags = fcntl(fd, F_GETFL);

    if (mode == TCL_MODE_BLOCKING) {
	flags &= ~O_NONBLOCK;
    } else {
	flags |= O_NONBLOCK;
    }
    return fcntl(fd, F_SETFL, flags);
#else /* USE_FIONBIO */
    int state = (mode == TCL_MODE_NONBLOCKING);

    return ioctl(fd, FIONBIO, &state);
#endif /* !USE_FIONBIO */
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetPwNam --
 *
 *      Thread-safe wrappers for getpwnam(). See "man getpwnam" for more
 *      details.
 *
 * Results:
 *      Pointer to struct passwd on success or NULL on error.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

struct passwd *
TclpGetPwNam(
    const char *name)
{
#if !TCL_THREADS
    return getpwnam(name);
#else
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

#if defined(HAVE_GETPWNAM_R_5)
    struct passwd *pwPtr = NULL;

    /*
     * How to allocate a buffer of the right initial size. If you want the
     * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt
     * and weep.
     */

    if (tsdPtr->pbuf == NULL) {
	tsdPtr->pbuflen = (int) sysconf(_SC_GETPW_R_SIZE_MAX);
	if (tsdPtr->pbuflen < 1) {
	    tsdPtr->pbuflen = 1024;
	}
	tsdPtr->pbuf = (char *)ckalloc(tsdPtr->pbuflen);
	Tcl_CreateThreadExitHandler(FreePwBuf, NULL);
    }
    while (1) {
	int e = getpwnam_r(name, &tsdPtr->pwd, tsdPtr->pbuf, tsdPtr->pbuflen,
		&pwPtr);

	if (e == 0) {
	    break;
	} else if (e != ERANGE) {
	    return NULL;
	}
	tsdPtr->pbuflen *= 2;
	tsdPtr->pbuf = (char *)ckrealloc(tsdPtr->pbuf, tsdPtr->pbuflen);
    }
    return (pwPtr != NULL ? &tsdPtr->pwd : NULL);

#elif defined(HAVE_GETPWNAM_R_4)
    return getpwnam_r(name, &tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf));

#else
    struct passwd *pwPtr;

    Tcl_MutexLock(&compatLock);
    pwPtr = getpwnam(name);
    if (pwPtr != NULL) {
	tsdPtr->pwd = *pwPtr;
	pwPtr = &tsdPtr->pwd;
	if (CopyPwd(&tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf)) == -1) {
	    pwPtr = NULL;
	}
    }
    Tcl_MutexUnlock(&compatLock);
    return pwPtr;
#endif

    return NULL;		/* Not reached. */
#endif /* TCL_THREADS */
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetPwUid --
 *
 *      Thread-safe wrappers for getpwuid(). See "man getpwuid" for more
 *      details.
 *
 * Results:
 *      Pointer to struct passwd on success or NULL on error.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

struct passwd *
TclpGetPwUid(
    uid_t uid)
{
#if !TCL_THREADS
    return getpwuid(uid);
#else
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

#if defined(HAVE_GETPWUID_R_5)
    struct passwd *pwPtr = NULL;

    /*
     * How to allocate a buffer of the right initial size. If you want the
     * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt
     * and weep.
     */

    if (tsdPtr->pbuf == NULL) {
	tsdPtr->pbuflen = (int) sysconf(_SC_GETPW_R_SIZE_MAX);
	if (tsdPtr->pbuflen < 1) {
	    tsdPtr->pbuflen = 1024;
	}
	tsdPtr->pbuf = (char *)ckalloc(tsdPtr->pbuflen);
	Tcl_CreateThreadExitHandler(FreePwBuf, NULL);
    }
    while (1) {
	int e = getpwuid_r(uid, &tsdPtr->pwd, tsdPtr->pbuf, tsdPtr->pbuflen,
		&pwPtr);

	if (e == 0) {
	    break;
	} else if (e != ERANGE) {
	    return NULL;
	}
	tsdPtr->pbuflen *= 2;
	tsdPtr->pbuf = (char *)ckrealloc(tsdPtr->pbuf, tsdPtr->pbuflen);
    }
    return (pwPtr != NULL ? &tsdPtr->pwd : NULL);

#elif defined(HAVE_GETPWUID_R_4)
    return getpwuid_r(uid, &tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf));

#else
    struct passwd *pwPtr;

    Tcl_MutexLock(&compatLock);
    pwPtr = getpwuid(uid);
    if (pwPtr != NULL) {
	tsdPtr->pwd = *pwPtr;
	pwPtr = &tsdPtr->pwd;
	if (CopyPwd(&tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf)) == -1) {
	    pwPtr = NULL;
	}
    }
    Tcl_MutexUnlock(&compatLock);
    return pwPtr;
#endif

    return NULL;		/* Not reached. */
#endif /* TCL_THREADS */
}

/*
 *---------------------------------------------------------------------------
 *
 * FreePwBuf --
 *
 *	Helper that is used to dispose of space allocated and referenced from
 *	the ThreadSpecificData for user entries. (Darn that baroque POSIX
 *	reentrant interface.)
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_PW_CLEANER
static void
FreePwBuf(
    TCL_UNUSED(ClientData))
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    ckfree(tsdPtr->pbuf);
}
#endif /* NEED_PW_CLEANER */

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetGrNam --
 *
 *      Thread-safe wrappers for getgrnam(). See "man getgrnam" for more
 *      details.
 *
 * Results:
 *      Pointer to struct group on success or NULL on error.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

struct group *
TclpGetGrNam(
    const char *name)
{
#if !TCL_THREADS
    return getgrnam(name);
#else
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

#if defined(HAVE_GETGRNAM_R_5)
    struct group *grPtr = NULL;

    /*
     * How to allocate a buffer of the right initial size. If you want the
     * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt
     * and weep.
     */

    if (tsdPtr->gbuf == NULL) {
	tsdPtr->gbuflen = (int) sysconf(_SC_GETGR_R_SIZE_MAX);
	if (tsdPtr->gbuflen < 1) {
	    tsdPtr->gbuflen = 1024;
	}
	tsdPtr->gbuf = (char *)ckalloc(tsdPtr->gbuflen);
	Tcl_CreateThreadExitHandler(FreeGrBuf, NULL);
    }
    while (1) {
	int e = getgrnam_r(name, &tsdPtr->grp, tsdPtr->gbuf, tsdPtr->gbuflen,
		&grPtr);

	if (e == 0) {
	    break;
	} else if (e != ERANGE) {
	    return NULL;
	}
	tsdPtr->gbuflen *= 2;
	tsdPtr->gbuf = (char *)ckrealloc(tsdPtr->gbuf, tsdPtr->gbuflen);
    }
    return (grPtr != NULL ? &tsdPtr->grp : NULL);

#elif defined(HAVE_GETGRNAM_R_4)
    return getgrnam_r(name, &tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf));

#else
    struct group *grPtr;

    Tcl_MutexLock(&compatLock);
    grPtr = getgrnam(name);
    if (grPtr != NULL) {
	tsdPtr->grp = *grPtr;
	grPtr = &tsdPtr->grp;
	if (CopyGrp(&tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf)) == -1) {
	    grPtr = NULL;
	}
    }
    Tcl_MutexUnlock(&compatLock);
    return grPtr;
#endif

    return NULL;		/* Not reached. */
#endif /* TCL_THREADS */
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetGrGid --
 *
 *      Thread-safe wrappers for getgrgid(). See "man getgrgid" for more
 *      details.
 *
 * Results:
 *      Pointer to struct group on success or NULL on error.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

struct group *
TclpGetGrGid(
    gid_t gid)
{
#if !TCL_THREADS
    return getgrgid(gid);
#else
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

#if defined(HAVE_GETGRGID_R_5)
    struct group *grPtr = NULL;

    /*
     * How to allocate a buffer of the right initial size. If you want the
     * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt
     * and weep.
     */

    if (tsdPtr->gbuf == NULL) {
	tsdPtr->gbuflen = (int) sysconf(_SC_GETGR_R_SIZE_MAX);
	if (tsdPtr->gbuflen < 1) {
	    tsdPtr->gbuflen = 1024;
	}
	tsdPtr->gbuf = (char *)ckalloc(tsdPtr->gbuflen);
	Tcl_CreateThreadExitHandler(FreeGrBuf, NULL);
    }
    while (1) {
	int e = getgrgid_r(gid, &tsdPtr->grp, tsdPtr->gbuf, tsdPtr->gbuflen,
		&grPtr);

	if (e == 0) {
	    break;
	} else if (e != ERANGE) {
	    return NULL;
	}
	tsdPtr->gbuflen *= 2;
	tsdPtr->gbuf = (char *)ckrealloc(tsdPtr->gbuf, tsdPtr->gbuflen);
    }
    return (grPtr != NULL ? &tsdPtr->grp : NULL);

#elif defined(HAVE_GETGRGID_R_4)
    return getgrgid_r(gid, &tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf));

#else
    struct group *grPtr;

    Tcl_MutexLock(&compatLock);
    grPtr = getgrgid(gid);
    if (grPtr != NULL) {
	tsdPtr->grp = *grPtr;
	grPtr = &tsdPtr->grp;
	if (CopyGrp(&tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf)) == -1) {
	    grPtr = NULL;
	}
    }
    Tcl_MutexUnlock(&compatLock);
    return grPtr;
#endif

    return NULL;		/* Not reached. */
#endif /* TCL_THREADS */
}

/*
 *---------------------------------------------------------------------------
 *
 * FreeGrBuf --
 *
 *	Helper that is used to dispose of space allocated and referenced from
 *	the ThreadSpecificData for group entries. (Darn that baroque POSIX
 *	reentrant interface.)
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_GR_CLEANER
static void
FreeGrBuf(
    TCL_UNUSED(ClientData))
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    ckfree(tsdPtr->gbuf);
}
#endif /* NEED_GR_CLEANER */

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetHostByName --
 *
 *      Thread-safe wrappers for gethostbyname(). See "man gethostbyname" for
 *      more details.
 *
 * Results:
 *      Pointer to struct hostent on success or NULL on error.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

struct hostent *
TclpGetHostByName(
    const char *name)
{
#if !TCL_THREADS || defined(HAVE_MTSAFE_GETHOSTBYNAME)
    return gethostbyname(name);
#else
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

#if defined(HAVE_GETHOSTBYNAME_R_5)
    int local_errno;

    return gethostbyname_r(name, &tsdPtr->hent, tsdPtr->hbuf,
			   sizeof(tsdPtr->hbuf), &local_errno);

#elif defined(HAVE_GETHOSTBYNAME_R_6)
    struct hostent *hePtr = NULL;
    int local_errno, result;

    result = gethostbyname_r(name, &tsdPtr->hent, tsdPtr->hbuf,
	    sizeof(tsdPtr->hbuf), &hePtr, &local_errno);
    return (result == 0) ? hePtr : NULL;

#elif defined(HAVE_GETHOSTBYNAME_R_3)
    struct hostent_data data;

    return (gethostbyname_r(name, &tsdPtr->hent, &data) == 0)
	    ? &tsdPtr->hent : NULL;

#else
#define NEED_COPYHOSTENT 1
    struct hostent *hePtr;

    Tcl_MutexLock(&compatLock);
    hePtr = gethostbyname(name);
    if (hePtr != NULL) {
	tsdPtr->hent = *hePtr;
	hePtr = &tsdPtr->hent;
	if (CopyHostent(&tsdPtr->hent, tsdPtr->hbuf,
		sizeof(tsdPtr->hbuf)) == -1) {
	    hePtr = NULL;
	}
    }
    Tcl_MutexUnlock(&compatLock);
    return hePtr;
#endif

    return NULL;		/* Not reached. */
#endif /* TCL_THREADS */
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetHostByAddr --
 *
 *      Thread-safe wrappers for gethostbyaddr(). See "man gethostbyaddr" for
 *      more details.
 *
 * Results:
 *      Pointer to struct hostent on success or NULL on error.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

struct hostent *
TclpGetHostByAddr(
    const char *addr,
    int length,
    int type)
{
#if !TCL_THREADS || defined(HAVE_MTSAFE_GETHOSTBYADDR)
    return gethostbyaddr(addr, length, type);
#else
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

#if defined(HAVE_GETHOSTBYADDR_R_7)
    int local_errno;

    return gethostbyaddr_r(addr, length, type, &tsdPtr->hent, tsdPtr->hbuf,
	    sizeof(tsdPtr->hbuf), &local_errno);

#elif defined(HAVE_GETHOSTBYADDR_R_8)
    struct hostent *hePtr;
    int local_errno;

    return (gethostbyaddr_r(addr, length, type, &tsdPtr->hent, tsdPtr->hbuf,
		sizeof(tsdPtr->hbuf), &hePtr, &local_errno) == 0)
	    ? &tsdPtr->hent : NULL;
#else
#define NEED_COPYHOSTENT 1
    struct hostent *hePtr;

    Tcl_MutexLock(&compatLock);
    hePtr = gethostbyaddr(addr, length, type);
    if (hePtr != NULL) {
	tsdPtr->hent = *hePtr;
	hePtr = &tsdPtr->hent;
	if (CopyHostent(&tsdPtr->hent, tsdPtr->hbuf,
		sizeof(tsdPtr->hbuf)) == -1) {
	    hePtr = NULL;
	}
    }
    Tcl_MutexUnlock(&compatLock);
    return hePtr;
#endif

    return NULL;		/* Not reached. */
#endif /* TCL_THREADS */
}

/*
 *---------------------------------------------------------------------------
 *
 * CopyGrp --
 *
 *      Copies string fields of the group structure to the private buffer,
 *      honouring the size of the buffer.
 *
 * Results:
 *      0 on success or -1 on error (errno = ERANGE).
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_COPYGRP
#define NEED_COPYARRAY 1
#define NEED_COPYSTRING 1

static int
CopyGrp(
    struct group *tgtPtr,
    char *buf,
    int buflen)
{
    char *p = buf;
    int copied, len = 0;

    /*
     * Copy username.
     */

    copied = CopyString(tgtPtr->gr_name, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->gr_name = (copied > 0) ? p : NULL;
    len += copied;
    p = buf + len;

    /*
     * Copy password.
     */

    copied = CopyString(tgtPtr->gr_passwd, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->gr_passwd = (copied > 0) ? p : NULL;
    len += copied;
    p = buf + len;

    /*
     * Copy group members.
     */

    PadBuffer(p, len, sizeof(char *));
    copied = CopyArray((char **)tgtPtr->gr_mem, -1, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->gr_mem = (copied > 0) ? (char **)p : NULL;

    return 0;

  range:
    errno = ERANGE;
    return -1;
}
#endif /* NEED_COPYGRP */

/*
 *---------------------------------------------------------------------------
 *
 * CopyHostent --
 *
 *      Copies string fields of the hostnent structure to the private buffer,
 *      honouring the size of the buffer.
 *
 * Results:
 *      Number of bytes copied on success or -1 on error (errno = ERANGE)
 *
 * Side effects:
 *      None
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_COPYHOSTENT
#define NEED_COPYSTRING 1
#define NEED_COPYARRAY 1

static int
CopyHostent(
    struct hostent *tgtPtr,
    char *buf,
    int buflen)
{
    char *p = buf;
    int copied, len = 0;

    copied = CopyString(tgtPtr->h_name, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->h_name = (copied > 0) ? p : NULL;
    len += copied;
    p = buf + len;

    PadBuffer(p, len, sizeof(char *));
    copied = CopyArray(tgtPtr->h_aliases, -1, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->h_aliases = (copied > 0) ? (char **)p : NULL;
    len += copied;
    p += len;

    PadBuffer(p, len, sizeof(char *));
    copied = CopyArray(tgtPtr->h_addr_list, tgtPtr->h_length, p, buflen-len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->h_addr_list = (copied > 0) ? (char **)p : NULL;

    return 0;

  range:
    errno = ERANGE;
    return -1;
}
#endif /* NEED_COPYHOSTENT */

/*
 *---------------------------------------------------------------------------
 *
 * CopyPwd --
 *
 *      Copies string fields of the passwd structure to the private buffer,
 *      honouring the size of the buffer.
 *
 * Results:
 *      0 on success or -1 on error (errno = ERANGE).
 *
 * Side effects:
 *      We are not copying the gecos field as it may not be supported on all
 *      platforms.
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_COPYPWD
#define NEED_COPYSTRING 1

static int
CopyPwd(
    struct passwd *tgtPtr,
    char *buf,
    int buflen)
{
    char *p = buf;
    int copied, len = 0;

    copied = CopyString(tgtPtr->pw_name, p, buflen - len);
    if (copied == -1) {
    range:
	errno = ERANGE;
	return -1;
    }
    tgtPtr->pw_name = (copied > 0) ? p : NULL;
    len += copied;
    p = buf + len;

    copied = CopyString(tgtPtr->pw_passwd, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->pw_passwd = (copied > 0) ? p : NULL;
    len += copied;
    p = buf + len;

    copied = CopyString(tgtPtr->pw_dir, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->pw_dir = (copied > 0) ? p : NULL;
    len += copied;
    p = buf + len;

    copied = CopyString(tgtPtr->pw_shell, p, buflen - len);
    if (copied == -1) {
	goto range;
    }
    tgtPtr->pw_shell = (copied > 0) ? p : NULL;

    return 0;
}
#endif /* NEED_COPYPWD */

/*
 *---------------------------------------------------------------------------
 *
 * CopyArray --
 *
 *      Copies array of NULL-terminated or fixed-length strings to the private
 *      buffer, honouring the size of the buffer.
 *
 * Results:
 *      Number of bytes copied on success or -1 on error (errno = ERANGE)
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_COPYARRAY
static int
CopyArray(
    char **src,			/* Array of elements to copy. */
    int elsize,			/* Size of each element, or -1 to indicate
				 * that they are C strings of dynamic
				 * length. */
    char *buf,			/* Buffer to copy into. */
    int buflen)			/* Size of buffer. */
{
    int i, j, len = 0;
    char *p, **newBuffer;

    if (src == NULL) {
	return 0;
    }

    for (i = 0; src[i] != NULL; i++) {
	/*
	 * Empty loop to count how many.
	 */
    }
    len = sizeof(char *) * (i + 1);	/* Leave place for the array. */
    if (len >  buflen) {
	return -1;
    }

    newBuffer = (char **)buf;
    p = buf + len;

    for (j = 0; j < i; j++) {
	int sz = (elsize<0 ? (int) strlen(src[j]) + 1 : elsize);

	len += sz;
	if (len > buflen) {
	    return -1;
	}
	memcpy(p, src[j], sz);
	newBuffer[j] = p;
	p = buf + len;
    }
    newBuffer[j] = NULL;

    return len;
}
#endif /* NEED_COPYARRAY */

/*
 *---------------------------------------------------------------------------
 *
 * CopyString --
 *
 *      Copies a NULL-terminated string to the private buffer, honouring the
 *      size of the buffer
 *
 * Results:
 *      0 success or -1 on error (errno = ERANGE)
 *
 * Side effects:
 *      None
 *
 *---------------------------------------------------------------------------
 */

#ifdef NEED_COPYSTRING
static int
CopyString(
    const char *src,		/* String to copy. */
    char *buf,			/* Buffer to copy into. */
    int buflen)			/* Size of buffer. */
{
    int len = 0;

    if (src != NULL) {
	len = strlen(src) + 1;
	if (len > buflen) {
	    return -1;
	}
	memcpy(buf, src, len);
    }

    return len;
}
#endif /* NEED_COPYSTRING */

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */

/*
 *------------------------------------------------------------------------
 *
 * TclWinCPUID --
 *
 *	Get CPU ID information on an Intel box under UNIX (either Linux or Cygwin)
 *
 * Results:
 *	Returns TCL_OK if successful, TCL_ERROR if CPUID is not supported.
 *
 * Side effects:
 *	If successful, stores EAX, EBX, ECX and EDX registers after the CPUID
 *	instruction in the four integers designated by 'regsPtr'
 *
 *----------------------------------------------------------------------
 */

int
TclWinCPUID(
    int index,		/* Which CPUID value to retrieve. */
    int *regsPtr)	/* Registers after the CPUID. */
{
    int status = TCL_ERROR;

    /* See: <http://en.wikipedia.org/wiki/CPUID> */
#if defined(HAVE_CPUID)
#if defined(__x86_64__) || defined(_M_AMD64) || defined (_M_X64)
    __asm__ __volatile__("movq %%rbx, %%rsi     \n\t" /* save %rbx */
                 "cpuid            \n\t"
                 "xchgq %%rsi, %%rbx   \n\t" /* restore the old %rbx */
                 : "=a"(regsPtr[0]), "=S"(regsPtr[1]), "=c"(regsPtr[2]), "=d"(regsPtr[3])
                 : "a"(index));
#else
    __asm__ __volatile__("mov %%ebx, %%esi     \n\t" /* save %ebx */
                 "cpuid            \n\t"
                 "xchg %%esi, %%ebx   \n\t" /* restore the old %ebx */
                 : "=a"(regsPtr[0]), "=S"(regsPtr[1]), "=c"(regsPtr[2]), "=d"(regsPtr[3])
                 : "a"(index));
#endif
    status = TCL_OK;
#endif
    return status;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */