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      1 /*	$NetBSD: zutil.c,v 1.5 2024/09/22 19:12:28 christos Exp $	*/
      2 
      3 /* zutil.c -- target dependent utility functions for the compression library
      4  * Copyright (C) 1995-2017 Jean-loup Gailly
      5  * For conditions of distribution and use, see copyright notice in zlib.h
      6  */
      7 
      8 /* @(#) Id */
      9 
     10 #include "zutil.h"
     11 #ifndef Z_SOLO
     12 #  include "gzguts.h"
     13 #endif
     14 
     15 z_const char * const z_errmsg[10] = {
     16     __UNCONST("need dictionary"),     /* Z_NEED_DICT       2  */
     17     __UNCONST("stream end"),          /* Z_STREAM_END      1  */
     18     __UNCONST(""),                    /* Z_OK              0  */
     19     __UNCONST("file error"),          /* Z_ERRNO         (-1) */
     20     __UNCONST("stream error"),        /* Z_STREAM_ERROR  (-2) */
     21     __UNCONST("data error"),          /* Z_DATA_ERROR    (-3) */
     22     __UNCONST("insufficient memory"), /* Z_MEM_ERROR     (-4) */
     23     __UNCONST("buffer error"),        /* Z_BUF_ERROR     (-5) */
     24     __UNCONST("incompatible version"),/* Z_VERSION_ERROR (-6) */
     25     __UNCONST(""),
     26 };
     27 
     28 
     29 const char * ZEXPORT zlibVersion(void) {
     30     return ZLIB_VERSION;
     31 }
     32 
     33 uLong ZEXPORT zlibCompileFlags(void) {
     34     uLong flags;
     35 
     36     flags = 0;
     37     switch ((int)(sizeof(uInt))) {
     38     case 2:     break;
     39     case 4:     flags += 1;     break;
     40     case 8:     flags += 2;     break;
     41     default:    flags += 3;
     42     }
     43     switch ((int)(sizeof(uLong))) {
     44     case 2:     break;
     45     case 4:     flags += 1 << 2;        break;
     46     case 8:     flags += 2 << 2;        break;
     47     default:    flags += 3 << 2;
     48     }
     49     switch ((int)(sizeof(voidpf))) {
     50     case 2:     break;
     51     case 4:     flags += 1 << 4;        break;
     52     case 8:     flags += 2 << 4;        break;
     53     default:    flags += 3 << 4;
     54     }
     55     switch ((int)(sizeof(z_off_t))) {
     56     case 2:     break;
     57     case 4:     flags += 1 << 6;        break;
     58     case 8:     flags += 2 << 6;        break;
     59     default:    flags += 3 << 6;
     60     }
     61 #ifdef ZLIB_DEBUG
     62     flags += 1 << 8;
     63 #endif
     64     /*
     65 #if defined(ASMV) || defined(ASMINF)
     66     flags += 1 << 9;
     67 #endif
     68      */
     69 #ifdef ZLIB_WINAPI
     70     flags += 1 << 10;
     71 #endif
     72 #ifdef BUILDFIXED
     73     flags += 1 << 12;
     74 #endif
     75 #ifdef DYNAMIC_CRC_TABLE
     76     flags += 1 << 13;
     77 #endif
     78 #ifdef NO_GZCOMPRESS
     79     flags += 1L << 16;
     80 #endif
     81 #ifdef NO_GZIP
     82     flags += 1L << 17;
     83 #endif
     84 #ifdef PKZIP_BUG_WORKAROUND
     85     flags += 1L << 20;
     86 #endif
     87 #ifdef FASTEST
     88     flags += 1L << 21;
     89 #endif
     90 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
     91 #  ifdef NO_vsnprintf
     92     flags += 1L << 25;
     93 #    ifdef HAS_vsprintf_void
     94     flags += 1L << 26;
     95 #    endif
     96 #  else
     97 #    ifdef HAS_vsnprintf_void
     98     flags += 1L << 26;
     99 #    endif
    100 #  endif
    101 #else
    102     flags += 1L << 24;
    103 #  ifdef NO_snprintf
    104     flags += 1L << 25;
    105 #    ifdef HAS_sprintf_void
    106     flags += 1L << 26;
    107 #    endif
    108 #  else
    109 #    ifdef HAS_snprintf_void
    110     flags += 1L << 26;
    111 #    endif
    112 #  endif
    113 #endif
    114     return flags;
    115 }
    116 
    117 #ifdef ZLIB_DEBUG
    118 #include <stdlib.h>
    119 #  ifndef verbose
    120 #    define verbose 0
    121 #  endif
    122 int ZLIB_INTERNAL z_verbose = verbose;
    123 
    124 void ZLIB_INTERNAL z_error(char *m) {
    125     fprintf(stderr, "%s\n", m);
    126     exit(1);
    127 }
    128 #endif
    129 
    130 /* exported to allow conversion of error code to string for compress() and
    131  * uncompress()
    132  */
    133 const char * ZEXPORT zError(int err) {
    134     return ERR_MSG(err);
    135 }
    136 
    137 #if defined(_WIN32_WCE) && _WIN32_WCE < 0x800
    138     /* The older Microsoft C Run-Time Library for Windows CE doesn't have
    139      * errno.  We define it as a global variable to simplify porting.
    140      * Its value is always 0 and should not be used.
    141      */
    142     int errno = 0;
    143 #endif
    144 
    145 #ifndef HAVE_MEMCPY
    146 
    147 void ZLIB_INTERNAL zmemcpy(Bytef* dest, const Bytef* source, uInt len) {
    148     if (len == 0) return;
    149     do {
    150         *dest++ = *source++; /* ??? to be unrolled */
    151     } while (--len != 0);
    152 }
    153 
    154 int ZLIB_INTERNAL zmemcmp(const Bytef* s1, const Bytef* s2, uInt len) {
    155     uInt j;
    156 
    157     for (j = 0; j < len; j++) {
    158         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
    159     }
    160     return 0;
    161 }
    162 
    163 void ZLIB_INTERNAL zmemzero(Bytef* dest, uInt len) {
    164     if (len == 0) return;
    165     do {
    166         *dest++ = 0;  /* ??? to be unrolled */
    167     } while (--len != 0);
    168 }
    169 #endif
    170 
    171 #ifndef Z_SOLO
    172 
    173 #ifdef SYS16BIT
    174 
    175 #ifdef __TURBOC__
    176 /* Turbo C in 16-bit mode */
    177 
    178 #  define MY_ZCALLOC
    179 
    180 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
    181  * and farmalloc(64K) returns a pointer with an offset of 8, so we
    182  * must fix the pointer. Warning: the pointer must be put back to its
    183  * original form in order to free it, use zcfree().
    184  */
    185 
    186 #define MAX_PTR 10
    187 /* 10*64K = 640K */
    188 
    189 local int next_ptr = 0;
    190 
    191 typedef struct ptr_table_s {
    192     voidpf org_ptr;
    193     voidpf new_ptr;
    194 } ptr_table;
    195 
    196 local ptr_table table[MAX_PTR];
    197 /* This table is used to remember the original form of pointers
    198  * to large buffers (64K). Such pointers are normalized with a zero offset.
    199  * Since MSDOS is not a preemptive multitasking OS, this table is not
    200  * protected from concurrent access. This hack doesn't work anyway on
    201  * a protected system like OS/2. Use Microsoft C instead.
    202  */
    203 
    204 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
    205     voidpf buf;
    206     ulg bsize = (ulg)items*size;
    207 
    208     (void)opaque;
    209 
    210     /* If we allocate less than 65520 bytes, we assume that farmalloc
    211      * will return a usable pointer which doesn't have to be normalized.
    212      */
    213     if (bsize < 65520L) {
    214         buf = farmalloc(bsize);
    215         if (*(ush*)&buf != 0) return buf;
    216     } else {
    217         buf = farmalloc(bsize + 16L);
    218     }
    219     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
    220     table[next_ptr].org_ptr = buf;
    221 
    222     /* Normalize the pointer to seg:0 */
    223     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
    224     *(ush*)&buf = 0;
    225     table[next_ptr++].new_ptr = buf;
    226     return buf;
    227 }
    228 
    229 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
    230     int n;
    231 
    232     (void)opaque;
    233 
    234     if (*(ush*)&ptr != 0) { /* object < 64K */
    235         farfree(ptr);
    236         return;
    237     }
    238     /* Find the original pointer */
    239     for (n = 0; n < next_ptr; n++) {
    240         if (ptr != table[n].new_ptr) continue;
    241 
    242         farfree(table[n].org_ptr);
    243         while (++n < next_ptr) {
    244             table[n-1] = table[n];
    245         }
    246         next_ptr--;
    247         return;
    248     }
    249     Assert(0, "zcfree: ptr not found");
    250 }
    251 
    252 #endif /* __TURBOC__ */
    253 
    254 
    255 #ifdef M_I86
    256 /* Microsoft C in 16-bit mode */
    257 
    258 #  define MY_ZCALLOC
    259 
    260 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
    261 #  define _halloc  halloc
    262 #  define _hfree   hfree
    263 #endif
    264 
    265 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size) {
    266     (void)opaque;
    267     return _halloc((long)items, size);
    268 }
    269 
    270 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
    271     (void)opaque;
    272     _hfree(ptr);
    273 }
    274 
    275 #endif /* M_I86 */
    276 
    277 #endif /* SYS16BIT */
    278 
    279 
    280 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
    281 
    282 #ifndef STDC
    283 extern voidp malloc(uInt size);
    284 extern voidp calloc(uInt items, uInt size);
    285 extern void free(voidpf ptr);
    286 #endif
    287 
    288 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
    289     (void)opaque;
    290     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
    291                               (voidpf)calloc(items, size);
    292 }
    293 
    294 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
    295     (void)opaque;
    296     free(ptr);
    297 }
    298 
    299 #endif /* MY_ZCALLOC */
    300 
    301 #endif /* !Z_SOLO */
    302