1 // SPDX-License-Identifier: Zlib
2 /* zutil.c -- target dependent utility functions for the compression library
3  * Copyright (C) 1995-2017 Jean-loup Gailly
4  * For conditions of distribution and use, see copyright notice in zlib.h
5  */
6 
7 /* @(#) $Id$ */
8 
9 #include "zutil.h"
10 #ifndef Z_SOLO
11 #  include "gzguts.h"
12 #endif
13 
14 z_const char * const z_errmsg[10] = {
15     (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
16     (z_const char *)"stream end",          /* Z_STREAM_END      1  */
17     (z_const char *)"",                    /* Z_OK              0  */
18     (z_const char *)"file error",          /* Z_ERRNO         (-1) */
19     (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
20     (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
21     (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
22     (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
23     (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
24     (z_const char *)""
25 };
26 
27 
zlibVersion()28 const char * ZEXPORT zlibVersion()
29 {
30     return ZLIB_VERSION;
31 }
32 
zlibCompileFlags()33 uLong ZEXPORT zlibCompileFlags()
34 {
35     uLong flags;
36 
37     flags = 0;
38     switch ((int)(sizeof(uInt))) {
39     case 2:     break;
40     case 4:     flags += 1;     break;
41     case 8:     flags += 2;     break;
42     default:    flags += 3;
43     }
44     switch ((int)(sizeof(uLong))) {
45     case 2:     break;
46     case 4:     flags += 1 << 2;        break;
47     case 8:     flags += 2 << 2;        break;
48     default:    flags += 3 << 2;
49     }
50     switch ((int)(sizeof(voidpf))) {
51     case 2:     break;
52     case 4:     flags += 1 << 4;        break;
53     case 8:     flags += 2 << 4;        break;
54     default:    flags += 3 << 4;
55     }
56     switch ((int)(sizeof(z_off_t))) {
57     case 2:     break;
58     case 4:     flags += 1 << 6;        break;
59     case 8:     flags += 2 << 6;        break;
60     default:    flags += 3 << 6;
61     }
62 #ifdef ZLIB_DEBUG
63     flags += 1 << 8;
64 #endif
65 #if defined(ASMV) || defined(ASMINF)
66     flags += 1 << 9;
67 #endif
68 #ifdef ZLIB_WINAPI
69     flags += 1 << 10;
70 #endif
71 #ifdef BUILDFIXED
72     flags += 1 << 12;
73 #endif
74 #ifdef DYNAMIC_CRC_TABLE
75     flags += 1 << 13;
76 #endif
77 #ifdef NO_GZCOMPRESS
78     flags += 1L << 16;
79 #endif
80 #ifdef NO_GZIP
81     flags += 1L << 17;
82 #endif
83 #ifdef PKZIP_BUG_WORKAROUND
84     flags += 1L << 20;
85 #endif
86 #ifdef FASTEST
87     flags += 1L << 21;
88 #endif
89 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
90 #  ifdef NO_vsnprintf
91     flags += 1L << 25;
92 #    ifdef HAS_vsprintf_void
93     flags += 1L << 26;
94 #    endif
95 #  else
96 #    ifdef HAS_vsnprintf_void
97     flags += 1L << 26;
98 #    endif
99 #  endif
100 #else
101     flags += 1L << 24;
102 #  ifdef NO_snprintf
103     flags += 1L << 25;
104 #    ifdef HAS_sprintf_void
105     flags += 1L << 26;
106 #    endif
107 #  else
108 #    ifdef HAS_snprintf_void
109     flags += 1L << 26;
110 #    endif
111 #  endif
112 #endif
113     return flags;
114 }
115 
116 #ifdef ZLIB_DEBUG
117 #include <stdlib.h>
118 #  ifndef verbose
119 #    define verbose 0
120 #  endif
121 int ZLIB_INTERNAL z_verbose = verbose;
122 
z_error(m)123 void ZLIB_INTERNAL z_error (m)
124     char *m;
125 {
126     fprintf(stderr, "%s\n", m);
127     exit(1);
128 }
129 #endif
130 
131 /* exported to allow conversion of error code to string for compress() and
132  * uncompress()
133  */
zError(err)134 const char * ZEXPORT zError(err)
135     int err;
136 {
137     return ERR_MSG(err);
138 }
139 
140 #if defined(_WIN32_WCE)
141     /* The Microsoft C Run-Time Library for Windows CE doesn't have
142      * errno.  We define it as a global variable to simplify porting.
143      * Its value is always 0 and should not be used.
144      */
145     int errno = 0;
146 #endif
147 
148 #ifndef HAVE_MEMCPY
149 
zmemcpy(dest,source,len)150 void ZLIB_INTERNAL zmemcpy(dest, source, len)
151     Bytef* dest;
152     const Bytef* source;
153     uInt  len;
154 {
155     if (len == 0) return;
156     do {
157         *dest++ = *source++; /* ??? to be unrolled */
158     } while (--len != 0);
159 }
160 
zmemcmp(s1,s2,len)161 int ZLIB_INTERNAL zmemcmp(s1, s2, len)
162     const Bytef* s1;
163     const Bytef* s2;
164     uInt  len;
165 {
166     uInt j;
167 
168     for (j = 0; j < len; j++) {
169         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
170     }
171     return 0;
172 }
173 
zmemzero(dest,len)174 void ZLIB_INTERNAL zmemzero(dest, len)
175     Bytef* dest;
176     uInt  len;
177 {
178     if (len == 0) return;
179     do {
180         *dest++ = 0;  /* ??? to be unrolled */
181     } while (--len != 0);
182 }
183 #endif
184 
185 #ifndef Z_SOLO
186 
187 #ifdef SYS16BIT
188 
189 #ifdef __TURBOC__
190 /* Turbo C in 16-bit mode */
191 
192 #  define MY_ZCALLOC
193 
194 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
195  * and farmalloc(64K) returns a pointer with an offset of 8, so we
196  * must fix the pointer. Warning: the pointer must be put back to its
197  * original form in order to free it, use zcfree().
198  */
199 
200 #define MAX_PTR 10
201 /* 10*64K = 640K */
202 
203 local int next_ptr = 0;
204 
205 typedef struct ptr_table_s {
206     voidpf org_ptr;
207     voidpf new_ptr;
208 } ptr_table;
209 
210 local ptr_table table[MAX_PTR];
211 /* This table is used to remember the original form of pointers
212  * to large buffers (64K). Such pointers are normalized with a zero offset.
213  * Since MSDOS is not a preemptive multitasking OS, this table is not
214  * protected from concurrent access. This hack doesn't work anyway on
215  * a protected system like OS/2. Use Microsoft C instead.
216  */
217 
zcalloc(voidpf opaque,unsigned items,unsigned size)218 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
219 {
220     voidpf buf;
221     ulg bsize = (ulg)items*size;
222 
223     (void)opaque;
224 
225     /* If we allocate less than 65520 bytes, we assume that farmalloc
226      * will return a usable pointer which doesn't have to be normalized.
227      */
228     if (bsize < 65520L) {
229         buf = farmalloc(bsize);
230         if (*(ush*)&buf != 0) return buf;
231     } else {
232         buf = farmalloc(bsize + 16L);
233     }
234     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
235     table[next_ptr].org_ptr = buf;
236 
237     /* Normalize the pointer to seg:0 */
238     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
239     *(ush*)&buf = 0;
240     table[next_ptr++].new_ptr = buf;
241     return buf;
242 }
243 
zcfree(voidpf opaque,voidpf ptr)244 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
245 {
246     int n;
247 
248     (void)opaque;
249 
250     if (*(ush*)&ptr != 0) { /* object < 64K */
251         farfree(ptr);
252         return;
253     }
254     /* Find the original pointer */
255     for (n = 0; n < next_ptr; n++) {
256         if (ptr != table[n].new_ptr) continue;
257 
258         farfree(table[n].org_ptr);
259         while (++n < next_ptr) {
260             table[n-1] = table[n];
261         }
262         next_ptr--;
263         return;
264     }
265     Assert(0, "zcfree: ptr not found");
266 }
267 
268 #endif /* __TURBOC__ */
269 
270 
271 #ifdef M_I86
272 /* Microsoft C in 16-bit mode */
273 
274 #  define MY_ZCALLOC
275 
276 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
277 #  define _halloc  halloc
278 #  define _hfree   hfree
279 #endif
280 
zcalloc(voidpf opaque,uInt items,uInt size)281 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
282 {
283     (void)opaque;
284     return _halloc((long)items, size);
285 }
286 
zcfree(voidpf opaque,voidpf ptr)287 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
288 {
289     (void)opaque;
290     _hfree(ptr);
291 }
292 
293 #endif /* M_I86 */
294 
295 #endif /* SYS16BIT */
296 
297 
298 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
299 
300 #ifndef STDC
301 extern voidp  malloc OF((uInt size));
302 extern voidp  calloc OF((uInt items, uInt size));
303 extern void   free   OF((voidpf ptr));
304 #endif
305 
zcalloc(opaque,items,size)306 voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
307     voidpf opaque;
308     unsigned items;
309     unsigned size;
310 {
311     (void)opaque;
312     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
313                               (voidpf)calloc(items, size);
314 }
315 
zcfree(opaque,ptr)316 void ZLIB_INTERNAL zcfree (opaque, ptr)
317     voidpf opaque;
318     voidpf ptr;
319 {
320     (void)opaque;
321     free(ptr);
322 }
323 
324 #endif /* MY_ZCALLOC */
325 
326 #endif /* !Z_SOLO */
327