File: util.c

package info (click to toggle)
polipo 1.1.1-5~bpo70+1
  • links: PTS, VCS
  • area: main
  • in suites: wheezy-backports
  • size: 1,204 kB
  • sloc: ansic: 20,882; python: 238; sh: 234; makefile: 139
file content (858 lines) | stat: -rw-r--r-- 18,577 bytes parent folder | download | duplicates (4)
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
/*
Copyright (c) 2003-2007 by Juliusz Chroboczek

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#include "polipo.h"

/* Note that this is different from GNU's strndup(3). */
char *
strdup_n(const char *restrict buf, int n)
{
    char *s;
    s = malloc(n + 1);
    if(s == NULL)
        return NULL;
    memcpy(s, buf, n);
    s[n] = '\0';
    return s;
}

int
snnprintf(char *restrict buf, int n, int len, const char *format, ...)
{
    va_list args;
    int rc;
    va_start(args, format);
    rc = snnvprintf(buf, n, len, format, args);
    va_end(args);
    return rc;
}

int
snnvprintf(char *restrict buf, int n, int len, const char *format, va_list args)
{
    int rc = -1;
    va_list args_copy;

    if(n < 0) return -2;
    if(n < len) {
        va_copy(args_copy, args);
        rc = vsnprintf(buf + n, len - n, format, args_copy);
        va_end(args_copy);
    }
    if(rc >= 0 && n + rc <= len)
        return n + rc;
    else
        return -1;
}

int
snnprint_n(char *restrict buf, int n, int len, const char *s, int slen)
{
    int i = 0;
    if(n < 0) return -2;
    while(i < slen && n < len)
        buf[n++] = s[i++];
    if(n < len)
        return n;
    else
        return -1;
}

int
strcmp_n(const char *string, const char *buf, int n)
{
    int i;
    i = 0;
    while(string[i] != '\0' && i < n) {
        if(string[i] < buf[i])
            return -1;
        else if(string[i] > buf[i])
            return 1;
        i++;
    }
    if(string[i] == '\0' || i == n)
        return 0;
    else if(i == n)
        return 1;
    else
        return -1;
}

int 
letter(char c)
{
    if(c >= 'A' && c <= 'Z') return 1;
    if(c >= 'a' && c <= 'z') return 1;
    return 0;
}

int
digit(char c)
{
    if(c >= '0' && c <= '9')
        return 1;
    return 0;
}

char
lwr(char a)
{
    if(a >= 'A' && a <= 'Z')
        return a | 0x20;
    else
        return a;
}

char *
lwrcpy(char *restrict dst, const char *restrict src, int n)
{
    int i;
    for(i = 0; i < n; i++)
        dst[i] = lwr(src[i]);
    return dst;
}

int
lwrcmp(const char *as, const char *bs, int n)
{
    int i;
    for(i = 0; i < n; i++) {
        char a = lwr(as[i]), b = lwr(bs[i]);
        if(a < b)
            return -1;
        else if(a > b)
            return 1;
    }
    return 0;
}

int
strcasecmp_n(const char *string, const char *buf, int n)
{
    int i;
    i = 0;
    while(string[i] != '\0' && i < n) {
        char a = lwr(string[i]), b = lwr(buf[i]);
        if(a < b)
            return -1;
        else if(a > b)
            return 1;
        i++;
    }
    if(string[i] == '\0' && i == n)
        return 0;
    else if(i == n)
        return 1;
    else
        return -1;
}

int
atoi_n(const char *restrict string, int n, int len, int *value_return)
{
    int i = n;
    int val = 0;

    if(i >= len || !digit(string[i]))
        return -1;

    while(i < len && digit(string[i])) {
        val = val * 10 + (string[i] - '0');
        i++;
    }
    *value_return = val;
    return i;
}

int 
isWhitespace(const char *string)
{
    while(*string != '\0') {
        if(*string == ' ' || *string == '\t')
            string++;
        else
            return 0;
    }
    return 1;
}

#ifndef HAVE_MEMRCHR
void *
memrchr(const void *s, int c, size_t n)
{
    const unsigned char *ss = s;
    unsigned char cc = c;
    size_t i;
    for(i = 1; i <= n; i++)
        if(ss[n - i] == cc)
            return (void*)(ss + n - i);
    return NULL;
}
#endif

int
h2i(char h) 
{
    if(h >= '0' && h <= '9')
        return h - '0';
    else if(h >= 'a' && h <= 'f')
        return h - 'a' + 10;
    else if(h >= 'A' && h <= 'F')
        return h - 'A' + 10;
    else
        return -1;
}
    
char
i2h(int i)
{
    if(i < 0 || i >= 16)
        return '?';
    if(i < 10)
        return i + '0';
    else
        return i - 10 + 'A';
}

/* floor(log2(x)) */
int
log2_floor(int x) 
{
    int i, j;

    assert(x > 0);

    i = 0;
    j = 1;
    while(2 * j <= x) {
        i++;
        j *= 2;
    }
    return i;
}

/* ceil(log2(x)) */
int
log2_ceil(int x) 
{
    int i, j;

    assert(x > 0);

    i = 0;
    j = 1;
    while(j < x) {
        i++;
        j *= 2;
    }
    return i;
}

#ifdef HAVE_ASPRINTF
char *
vsprintf_a(const char *f, va_list args)
{
    char *r;
    int rc;
    va_list args_copy;

    va_copy(args_copy, args);
    rc = vasprintf(&r, f, args_copy);
    va_end(args_copy);
    if(rc < 0)
        return NULL;
    return r;
    
}

#else

char*
vsprintf_a(const char *f, va_list args)
{
    int n, size;
    char buf[64];
    char *string;
    va_list args_copy;

    va_copy(args_copy, args);
    n = vsnprintf(buf, 64, f, args_copy);
    va_end(args_copy);
    if(n >= 0 && n < 64) {
        return strdup_n(buf, n);
    }
    if(n >= 64)
        size = n + 1;
    else
        size = 96;

    while(1) {
        string = malloc(size);
        if(!string)
            return NULL;
        va_copy(args_copy, args);
        n = vsnprintf(string, size, f, args_copy);
        va_end(args_copy);
        if(n >= 0 && n < size) {
            return string;
        } else if(n >= size)
            size = n + 1;
        else
            size = size * 3 / 2;
        free(string);
        if(size > 16 * 1024)
            return NULL;
    }
    /* NOTREACHED */
}
#endif

char*
sprintf_a(const char *f, ...)
{
    char *s;
    va_list args;
    va_start(args, f);
    s = vsprintf_a(f, args);
    va_end(args);
    return s;
}    

unsigned int
hash(unsigned int seed, const void *restrict key, int key_size,
     unsigned int hash_size)
{
    int i;
    unsigned int h;

    h = seed;
    for(i = 0; i < key_size; i++)
        h = (h << 5) + (h >> (hash_size - 5)) +
            ((unsigned char*)key)[i];
    return h & ((1 << hash_size) - 1);
}

char *
pstrerror(int e)
{
    char *s;
    static char buf[20];

    switch(e) {
    case EDOSHUTDOWN: s = "Immediate shutdown requested"; break;
    case EDOGRACEFUL: s = "Graceful shutdown requested"; break;
    case EDOTIMEOUT: s = "Timeout"; break;
    case ECLIENTRESET: s = "Connection reset by client"; break;
    case ESYNTAX: s = "Incorrect syntax"; break;
    case EREDIRECTOR: s = "Redirector error"; break;
    case EDNS_HOST_NOT_FOUND: s = "Host not found"; break;
    case EDNS_NO_ADDRESS: s = "No address"; break;
    case EDNS_NO_RECOVERY: s = "Permanent name server failure"; break;
    case EDNS_TRY_AGAIN: s = "Temporary name server failure"; break;
    case EDNS_INVALID: s = "Invalid reply from name server"; break;
    case EDNS_UNSUPPORTED: s = "Unsupported DNS reply"; break;
    case EDNS_FORMAT: s = "Invalid DNS query"; break;
    case EDNS_REFUSED: s = "DNS query refused by server"; break;
    case EDNS_CNAME_LOOP: s = "DNS CNAME loop"; break;
#ifndef NO_SOCKS
    case ESOCKS_PROTOCOL: s = "SOCKS protocol error"; break;
    case ESOCKS_REJECT_FAIL: s = "SOCKS request rejected or failed"; break;
    case ESOCKS_REJECT_IDENTD: s = "SOCKS request rejected: "
                                   "server couldn't connect to identd";
        break;
    case ESOCKS_REJECT_UID_MISMATCH: s = "SOCKS request rejected: "
                                         "uid mismatch";
        break;
    case ESOCKS5_BASE: s = "SOCKS success"; break;
    case ESOCKS5_BASE + 1: s = "General SOCKS server failure"; break;
    case ESOCKS5_BASE + 2: s = "SOCKS connection not allowed"; break;
    case ESOCKS5_BASE + 3: s = "SOCKS error: network unreachable"; break;
    case ESOCKS5_BASE + 4: s = "SOCKS error: host unreachable"; break;
    case ESOCKS5_BASE + 5: s = "SOCKS error: connection refused"; break;
    case ESOCKS5_BASE + 6: s = "SOCKS error: TTL expired"; break;
    case ESOCKS5_BASE + 7: s = "SOCKS command not supported"; break;
    case ESOCKS5_BASE + 8: s = "SOCKS error: address type not supported";
        break;
#endif
    case EUNKNOWN: s = "Unknown error"; break;
    default: s = NULL; break;
    }
    if(!s) s = strerror(e);
#ifdef WIN32 /*MINGW*/
    if(!s) {
        if(e >= WSABASEERR && e <= WSABASEERR + 2000) {
            /* This should be okay, as long as the caller discards the
               pointer before another error occurs. */
            snprintf(buf, 20, "Winsock error %d", e);
            s = buf;
        }
    }
#endif
    if(!s) {
        snprintf(buf, 20, "Unknown error %d", e);
        s = buf;
    }
    return s;
}

/* Like mktime(3), but UTC rather than local time */
#if defined(HAVE_TIMEGM)
time_t
mktime_gmt(struct tm *tm)
{
    return timegm(tm);
}
#elif defined(HAVE_MKGMTIME)
time_t
mktime_gmt(struct tm *tm)
{
    return _mkgmtime(tm);
}
#elif defined(HAVE_TM_GMTOFF)
time_t
mktime_gmt(struct tm *tm)
{
    time_t t;
    struct tm *ltm;

    t = mktime(tm);
    if(t < 0)
        return -1;
    ltm = localtime(&t);
    if(ltm == NULL)
        return -1;
    return t + ltm->tm_gmtoff;
}
#elif defined(HAVE_TZSET)
#ifdef HAVE_SETENV
/* Taken from the Linux timegm(3) man page. */
time_t
mktime_gmt(struct tm *tm)
{
    time_t t;
    char *tz;

    tz = getenv("TZ");
    setenv("TZ", "GMT", 1);
    tzset();
    t = mktime(tm);
    if(tz)
        setenv("TZ", tz, 1);
    else
        unsetenv("TZ");
    tzset();
    return t;
}
#else
time_t
mktime_gmt(struct tm *tm)
{
    time_t t;
    char *tz;
    static char *old_tz = NULL;

    tz = getenv("TZ");
    putenv("TZ=GMT");
    tzset();
    t = mktime(tm);
    if(old_tz)
        free(old_tz);
    if(tz)
        old_tz = sprintf_a("TZ=%s", tz);
    else
        old_tz = strdup("TZ");  /* XXX - non-portable? */
    if(old_tz)
        putenv(old_tz);
    tzset();
    return t;
}
#endif
#else
#error no mktime_gmt implementation on this platform
#endif


AtomPtr
expandTilde(AtomPtr filename)
{
    char *buf;
    char *home;
    int len;
    AtomPtr ret;

    if(filename == NULL || filename->length < 1 ||
       filename->string[0] != '~' || filename->string[1] != '/')
        return filename;
    
    home = getenv("HOME");
    if(home == NULL) {
        return NULL;
    }
    len = strlen(home);
    buf = malloc(len + 1 + 1 + filename->length - 2);
    if(buf == NULL) {
        do_log(L_ERROR, "Could not allocate buffer.\n");
        return NULL;
    }

    memcpy(buf, home, len);
    if(buf[len - 1] != '/')
        buf[len++] = '/';
    memcpy(buf + len, filename->string + 2, filename->length - 2);
    len += filename->length - 2;
    ret = internAtomN(buf, len);
    free(buf);
    if(ret != NULL)
        releaseAtom(filename);
    return ret;
}

#ifdef HAVE_FORK
void
do_daemonise(int noclose)
{
    int rc;

    fflush(stdout);
    fflush(stderr);

    rc = fork();
    if(rc < 0) {
        do_log_error(L_ERROR, errno, "Couldn't fork");
        exit(1);
    }

    if(rc > 0)
        exit(0);

    if(!noclose) {
        int fd;
        close(0);
        close(1);
        close(2);
        /* Leaving the default file descriptors free is not a good
           idea, as it will cause library functions such as abort to
           thrash the on-disk cache. */
        fd = open("/dev/null", O_RDONLY);
        if(fd > 0) {
            dup2(fd, 0);
            close(fd);
        }
        fd = open("/dev/null", O_WRONLY);
        if(fd >= 0) {
            if(fd != 1)
                dup2(fd, 1);
            if(fd != 2)
                dup2(fd, 2);
            if(fd != 1 && fd != 2)
                close(fd);
        }
    }
    rc = setsid();
    if(rc < 0) {
        do_log_error(L_ERROR, errno, "Couldn't create new session");
        exit(1);
    }
}

#elif defined(WIN32)

void
do_daemonise(int noclose)
{
	do_log(L_INFO, "Detaching console");
	FreeConsole();
}

#else

void
do_daemonise(int noclose)
{
    do_log(L_ERROR, "Cannot daemonise on this platform");
    exit(1);
}
#endif


void
writePid(char *pidfile)
{
    int fd, n, rc;
    char buf[16];

    fd = open(pidfile, O_WRONLY | O_CREAT | O_EXCL, 0666);
    if(fd < 0) {
        do_log_error(L_ERROR, errno, 
                     "Couldn't create pid file %s", pidfile);
        exit(1);
    }
    n = snprintf(buf, 16, "%ld\n", (long)getpid());
    if(n < 0 || n >= 16) {
        close(fd);
        unlink(pidfile);
        do_log(L_ERROR, "Couldn't format pid.\n");
        exit(1);
    }
    rc = write(fd, buf, n);
    if(rc != n) {
        close(fd);
        unlink(pidfile);
        do_log_error(L_ERROR, errno, "Couldn't write pid");
        exit(1);
    }

    close(fd);
    return;
}

static const char b64[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

/* "/" replaced with "-" */
static const char b64fss[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-";

int
b64cpy(char *restrict dst, const char *restrict src, int n, int fss)
{
    const char *b = fss ? b64fss: b64;
    int i, j;

    j = 0;
    for(i = 0; i < n; i += 3) {
        unsigned char a0, a1, a2;
        a0 = src[i];
        a1 = i < n - 1 ? src[i + 1] : 0;
        a2 = i < n - 2 ? src[i + 2] : 0;
        dst[j++] = b[(a0 >> 2) & 0x3F];
        dst[j++] = b[((a0 << 4) & 0x30) | ((a1 >> 4) & 0x0F)];
        if(i < n - 1)
            dst[j++] = b[((a1 << 2) & 0x3C) | ((a2 >> 6) & 0x03)];
        else
            dst[j++] = '=';
        if(i < n - 2)
            dst[j++] = b[a2 & 0x3F];
        else
            dst[j++] = '=';
    }
    return j;
}

int
b64cmp(const char *restrict a, int an, const char *restrict b, int bn)
{
    char *buf;
    int r;

    if(an % 4 != 0)
        return -1;
    if((bn + 2) / 3 != an / 4)
        return -1;
    buf = malloc(an);
    if(buf == NULL)
        return -1;
    b64cpy(buf, b, bn, 0);
    r = memcmp(buf, a, an);
    free(buf);
    return r;
}

IntListPtr
makeIntList(int size)
{
    IntListPtr list;
    if(size <= 0)
        size = 4;

    list = malloc(sizeof(IntListRec));
    if(list == NULL)
        return NULL;

    list->ranges = malloc(size * sizeof(IntRangeRec));
    if(list->ranges == NULL) {
        free(list);
        return NULL;
    }

    list->length = 0;
    list->size = size;
    return list;
}

void
destroyIntList(IntListPtr list)
{
    free(list->ranges);
    free(list);
}

int
intListMember(int n, IntListPtr list)
{
    int lo = 0, hi = list->length - 1;
    int mid;
    while(hi >= lo) {
        mid = (hi + lo) / 2;
        if(list->ranges[mid].from > n)
            hi = mid - 1;
        else if(list->ranges[mid].to < n)
            lo = mid + 1;
        else
            return 1;
    }
    return 0;
}

static int
deleteRange(IntListPtr list, int i)
{
    assert(list->length > i);
    if(list->length > i + 1)
        memmove(list->ranges + i, list->ranges + i + 1,
                (list->length - i - 1) * sizeof(IntRangeRec));
    list->length--;
    return 1;
}

static int
insertRange(int from, int to, IntListPtr list, int i)
{
    assert(i >= 0 && i <= list->length);
    assert(i == 0 || list->ranges[i - 1].to < from - 1);
    assert(i == list->length || list->ranges[i].from > to + 1);

    if(list->length >= list->size) {
        int newsize = list->size * 2 + 1;
        IntRangePtr newranges = 
            realloc(list->ranges, newsize * sizeof(IntRangeRec));
        if(newranges == NULL)
            return -1;
        list->size = newsize;
        list->ranges = newranges;
    }

    if(i < list->length)
        memmove(list->ranges + i + 1, list->ranges + i,
                list->length - i);
    list->length++;
    list->ranges[i].from = from;
    list->ranges[i].to = to;
    return 1;
}

static int
maybeMergeRanges(IntListPtr list, int i)
{
    int rc;

    while(i > 0 && list->ranges[i].from <= list->ranges[i - 1].to + 1) {
            list->ranges[i - 1].from = 
                MIN(list->ranges[i - 1].from, list->ranges[i].from);
            list->ranges[i - 1].to =
                MAX(list->ranges[i - 1].to, list->ranges[i].to);
            rc = deleteRange(list, i);
            if(rc < 0) return -1;
            i--;
    }

    while(i < list->length - 1 && 
          list->ranges[i].to >= list->ranges[i + 1].from - 1) {
            list->ranges[i + 1].from = 
                MIN(list->ranges[i + 1].from, list->ranges[i].from);
            list->ranges[i - 1].to =
                MAX(list->ranges[i + 1].to, list->ranges[i].to);
            rc = deleteRange(list, i);
            if(rc < 0) return -1;
    }
    return 1;
}

int
intListCons(int from, int to, IntListPtr list)
{
    int i;

    /* Don't bother with the dichotomy. */
    for(i = 0; i < list->length; i++) {
        if(list->ranges[i].to >= from - 1)
            break;
    }

    if(i < list->length && 
       (from >= list->ranges[i].from - 1 || to <= list->ranges[i].to + 1)) {
        if(from <= list->ranges[i].from)
            list->ranges[i].from = from;
        if(to >= list->ranges[i].to)
            list->ranges[i].to = to;
        return maybeMergeRanges(list, i);
    }
    return insertRange(from, to, list, i);
}

/* Return the amount of physical memory on the box, -1 if unknown or
   over two gigs. */
#if defined(__linux__)

#include <sys/sysinfo.h>
int
physicalMemory()
{
    int rc;
    struct sysinfo info;

    rc = sysinfo(&info);
    if(rc < 0)
        return -1;

    if(info.totalram <= 0x7fffffff / info.mem_unit)
        return (int)(info.totalram * info.mem_unit);

    return -1;
}

#elif defined(__FreeBSD__)

#include <sys/sysctl.h>
int
physicalMemory()
{
    unsigned long membytes;
    size_t len;
    int res;

    len = sizeof(membytes);
    res = sysctlbyname("hw.physmem", &membytes, &len, NULL, 0);
    if (res || membytes > INT_MAX)
        return -1;

    return (int)membytes;
}

#else

int
physicalMemory()
{
    return -1;
}
#endif