1 /* zutil.c -- target dependent utility functions for the compression library
2  * Copyright (C) 1995-2017 Jean-loup Gailly
3  * For conditions of distribution and use, see copyright notice in zlib.h
4  */
5 
6 /* @(#) $Id$ */
7 
8 #include "zutil.h"
9 #ifndef Z_SOLO
10 #  include "gzguts.h"
11 #endif
12 
13 z_const char * const z_errmsg[10] = {
14     (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
15     (z_const char *)"stream end",          /* Z_STREAM_END      1  */
16     (z_const char *)"",                    /* Z_OK              0  */
17     (z_const char *)"file error",          /* Z_ERRNO         (-1) */
18     (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
19     (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
20     (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
21     (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
22     (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
23     (z_const char *)""
24 };
25 
26 
zlibVersion(void)27 const char * ZEXPORT zlibVersion(void)
28 {
29     return ZLIB_VERSION;
30 }
31 
zlibCompileFlags(void)32 uLong ZEXPORT zlibCompileFlags(void)
33 {
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 
z_error(char *m)124 void ZLIB_INTERNAL z_error(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(int err)134 const char * ZEXPORT zError(int err)
135 {
136     return ERR_MSG(err);
137 }
138 
139 #if defined(_WIN32_WCE) && _WIN32_WCE < 0x800
140     /* The older Microsoft C Run-Time Library for Windows CE doesn't have
141      * errno.  We define it as a global variable to simplify porting.
142      * Its value is always 0 and should not be used.
143      */
144     int errno = 0;
145 #endif
146 
147 #ifndef HAVE_MEMCPY
148 
zmemcpy(Bytef* dest, const Bytef* source, uInt len)149 void ZLIB_INTERNAL zmemcpy(Bytef* dest, const Bytef* source, uInt len)
150 {
151     if (len == 0) return;
152     do {
153         *dest++ = *source++; /* ??? to be unrolled */
154     } while (--len != 0);
155 }
156 
zmemcmp(const Bytef* s1, const Bytef* s2, uInt len)157 int ZLIB_INTERNAL zmemcmp(const Bytef* s1, const Bytef* s2, uInt len)
158 {
159     uInt j;
160 
161     for (j = 0; j < len; j++) {
162         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
163     }
164     return 0;
165 }
166 
zmemzero(Bytef* dest, uInt len)167 void ZLIB_INTERNAL zmemzero(Bytef* dest, uInt len)
168 {
169     if (len == 0) return;
170     do {
171         *dest++ = 0;  /* ??? to be unrolled */
172     } while (--len != 0);
173 }
174 #endif
175 
176 #ifndef Z_SOLO
177 
178 #ifdef SYS16BIT
179 
180 #ifdef __TURBOC__
181 /* Turbo C in 16-bit mode */
182 
183 #  define MY_ZCALLOC
184 
185 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
186  * and farmalloc(64K) returns a pointer with an offset of 8, so we
187  * must fix the pointer. Warning: the pointer must be put back to its
188  * original form in order to free it, use zcfree().
189  */
190 
191 #define MAX_PTR 10
192 /* 10*64K = 640K */
193 
194 local int next_ptr = 0;
195 
196 typedef struct ptr_table_s {
197     voidpf org_ptr;
198     voidpf new_ptr;
199 } ptr_table;
200 
201 local ptr_table table[MAX_PTR];
202 /* This table is used to remember the original form of pointers
203  * to large buffers (64K). Such pointers are normalized with a zero offset.
204  * Since MSDOS is not a preemptive multitasking OS, this table is not
205  * protected from concurrent access. This hack doesn't work anyway on
206  * a protected system like OS/2. Use Microsoft C instead.
207  */
208 
zcalloc(voidpf opaque, unsigned items, unsigned size)209 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size)
210 {
211     voidpf buf;
212     ulg bsize = (ulg)items*size;
213 
214     (void)opaque;
215 
216     /* If we allocate less than 65520 bytes, we assume that farmalloc
217      * will return a usable pointer which doesn't have to be normalized.
218      */
219     if (bsize < 65520L) {
220         buf = farmalloc(bsize);
221         if (*(ush*)&buf != 0) return buf;
222     } else {
223         buf = farmalloc(bsize + 16L);
224     }
225     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
226     table[next_ptr].org_ptr = buf;
227 
228     /* Normalize the pointer to seg:0 */
229     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
230     *(ush*)&buf = 0;
231     table[next_ptr++].new_ptr = buf;
232     return buf;
233 }
234 
zcfree(voidpf opaque, voidpf ptr)235 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
236 {
237     int n;
238 
239     (void)opaque;
240 
241     if (*(ush*)&ptr != 0) { /* object < 64K */
242         farfree(ptr);
243         return;
244     }
245     /* Find the original pointer */
246     for (n = 0; n < next_ptr; n++) {
247         if (ptr != table[n].new_ptr) continue;
248 
249         farfree(table[n].org_ptr);
250         while (++n < next_ptr) {
251             table[n-1] = table[n];
252         }
253         next_ptr--;
254         return;
255     }
256     Assert(0, "zcfree: ptr not found");
257 }
258 
259 #endif /* __TURBOC__ */
260 
261 
262 #ifdef M_I86
263 /* Microsoft C in 16-bit mode */
264 
265 #  define MY_ZCALLOC
266 
267 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
268 #  define _halloc  halloc
269 #  define _hfree   hfree
270 #endif
271 
zcalloc(voidpf opaque, uInt items, uInt size)272 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size)
273 {
274     (void)opaque;
275     return _halloc((long)items, size);
276 }
277 
zcfree(voidpf opaque, voidpf ptr)278 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
279 {
280     (void)opaque;
281     _hfree(ptr);
282 }
283 
284 #endif /* M_I86 */
285 
286 #endif /* SYS16BIT */
287 
288 
289 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
290 
291 #ifndef STDC
292 extern voidp malloc(uInt size);
293 extern voidp calloc(uInt items, uInt size);
294 extern void free(voidpf ptr);
295 #endif
296 
zcalloc(voidpf opaque, unsigned items, unsigned size)297 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size)
298 {
299     (void)opaque;
300     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
301                               (voidpf)calloc(items, size);
302 }
303 
zcfree(voidpf opaque, voidpf ptr)304 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
305 {
306     (void)opaque;
307     free(ptr);
308 }
309 
310 #endif /* MY_ZCALLOC */
311 
312 #endif /* !Z_SOLO */
313