xref: /openbsd-src/lib/libz/zutil.c (revision 4e1ee0786f11cc571bd0be17d38e46f635c719fc)
1 /*	$OpenBSD: zutil.c,v 1.10 2021/07/04 14:24:49 tb Exp $ */
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 #include "zutil.h"
8 #ifndef Z_SOLO
9 #  include "gzguts.h"
10 #endif
11 
12 z_const char * const z_errmsg[10] = {
13     (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
14     (z_const char *)"stream end",          /* Z_STREAM_END      1  */
15     (z_const char *)"",                    /* Z_OK              0  */
16     (z_const char *)"file error",          /* Z_ERRNO         (-1) */
17     (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
18     (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
19     (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
20     (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
21     (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
22     (z_const char *)""
23 };
24 
25 
26 const char * ZEXPORT zlibVersion()
27 {
28     return ZLIB_VERSION;
29 }
30 
31 uLong ZEXPORT zlibCompileFlags()
32 {
33     uLong flags;
34 
35     flags = 0;
36     switch ((int)(sizeof(uInt))) {
37     case 2:     break;
38     case 4:     flags += 1;     break;
39     case 8:     flags += 2;     break;
40     default:    flags += 3;
41     }
42     switch ((int)(sizeof(uLong))) {
43     case 2:     break;
44     case 4:     flags += 1 << 2;        break;
45     case 8:     flags += 2 << 2;        break;
46     default:    flags += 3 << 2;
47     }
48     switch ((int)(sizeof(voidpf))) {
49     case 2:     break;
50     case 4:     flags += 1 << 4;        break;
51     case 8:     flags += 2 << 4;        break;
52     default:    flags += 3 << 4;
53     }
54     switch ((int)(sizeof(z_off_t))) {
55     case 2:     break;
56     case 4:     flags += 1 << 6;        break;
57     case 8:     flags += 2 << 6;        break;
58     default:    flags += 3 << 6;
59     }
60 #ifdef ZLIB_DEBUG
61     flags += 1 << 8;
62 #endif
63 #if defined(ASMV) || defined(ASMINF)
64     flags += 1 << 9;
65 #endif
66 #ifdef ZLIB_WINAPI
67     flags += 1 << 10;
68 #endif
69 #ifdef BUILDFIXED
70     flags += 1 << 12;
71 #endif
72 #ifdef DYNAMIC_CRC_TABLE
73     flags += 1 << 13;
74 #endif
75 #ifdef NO_GZCOMPRESS
76     flags += 1L << 16;
77 #endif
78 #ifdef NO_GZIP
79     flags += 1L << 17;
80 #endif
81 #ifdef PKZIP_BUG_WORKAROUND
82     flags += 1L << 20;
83 #endif
84 #ifdef FASTEST
85     flags += 1L << 21;
86 #endif
87 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
88 #  ifdef NO_vsnprintf
89     flags += 1L << 25;
90 #    ifdef HAS_vsprintf_void
91     flags += 1L << 26;
92 #    endif
93 #  else
94 #    ifdef HAS_vsnprintf_void
95     flags += 1L << 26;
96 #    endif
97 #  endif
98 #else
99     flags += 1L << 24;
100 #  ifdef NO_snprintf
101     flags += 1L << 25;
102 #    ifdef HAS_sprintf_void
103     flags += 1L << 26;
104 #    endif
105 #  else
106 #    ifdef HAS_snprintf_void
107     flags += 1L << 26;
108 #    endif
109 #  endif
110 #endif
111     return flags;
112 }
113 
114 #ifdef ZLIB_DEBUG
115 #include <stdlib.h>
116 #  ifndef verbose
117 #    define verbose 0
118 #  endif
119 int ZLIB_INTERNAL z_verbose = verbose;
120 
121 void ZLIB_INTERNAL z_error (m)
122     char *m;
123 {
124     fprintf(stderr, "%s\n", m);
125     exit(1);
126 }
127 #endif
128 
129 /* exported to allow conversion of error code to string for compress() and
130  * uncompress()
131  */
132 const char * ZEXPORT zError(err)
133     int err;
134 {
135     return ERR_MSG(err);
136 }
137 
138 #if defined(_WIN32_WCE)
139     /* The Microsoft C Run-Time Library for Windows CE doesn't have
140      * errno.  We define it as a global variable to simplify porting.
141      * Its value is always 0 and should not be used.
142      */
143     int errno = 0;
144 #endif
145 
146 #ifndef HAVE_MEMCPY
147 
148 void ZLIB_INTERNAL zmemcpy(dest, source, len)
149     Bytef* dest;
150     const Bytef* source;
151     uInt  len;
152 {
153     if (len == 0) return;
154     do {
155         *dest++ = *source++; /* ??? to be unrolled */
156     } while (--len != 0);
157 }
158 
159 int ZLIB_INTERNAL zmemcmp(s1, s2, len)
160     const Bytef* s1;
161     const Bytef* s2;
162     uInt  len;
163 {
164     uInt j;
165 
166     for (j = 0; j < len; j++) {
167         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
168     }
169     return 0;
170 }
171 
172 void ZLIB_INTERNAL zmemzero(dest, len)
173     Bytef* dest;
174     uInt  len;
175 {
176     if (len == 0) return;
177     do {
178         *dest++ = 0;  /* ??? to be unrolled */
179     } while (--len != 0);
180 }
181 #endif
182 
183 #ifndef Z_SOLO
184 
185 #ifdef SYS16BIT
186 
187 #ifdef __TURBOC__
188 /* Turbo C in 16-bit mode */
189 
190 #  define MY_ZCALLOC
191 
192 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
193  * and farmalloc(64K) returns a pointer with an offset of 8, so we
194  * must fix the pointer. Warning: the pointer must be put back to its
195  * original form in order to free it, use zcfree().
196  */
197 
198 #define MAX_PTR 10
199 /* 10*64K = 640K */
200 
201 local int next_ptr = 0;
202 
203 typedef struct ptr_table_s {
204     voidpf org_ptr;
205     voidpf new_ptr;
206 } ptr_table;
207 
208 local ptr_table table[MAX_PTR];
209 /* This table is used to remember the original form of pointers
210  * to large buffers (64K). Such pointers are normalized with a zero offset.
211  * Since MSDOS is not a preemptive multitasking OS, this table is not
212  * protected from concurrent access. This hack doesn't work anyway on
213  * a protected system like OS/2. Use Microsoft C instead.
214  */
215 
216 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
217 {
218     voidpf buf;
219     ulg bsize = (ulg)items*size;
220 
221     (void)opaque;
222 
223     /* If we allocate less than 65520 bytes, we assume that farmalloc
224      * will return a usable pointer which doesn't have to be normalized.
225      */
226     if (bsize < 65520L) {
227         buf = farmalloc(bsize);
228         if (*(ush*)&buf != 0) return buf;
229     } else {
230         buf = farmalloc(bsize + 16L);
231     }
232     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
233     table[next_ptr].org_ptr = buf;
234 
235     /* Normalize the pointer to seg:0 */
236     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
237     *(ush*)&buf = 0;
238     table[next_ptr++].new_ptr = buf;
239     return buf;
240 }
241 
242 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
243 {
244     int n;
245 
246     (void)opaque;
247 
248     if (*(ush*)&ptr != 0) { /* object < 64K */
249         farfree(ptr);
250         return;
251     }
252     /* Find the original pointer */
253     for (n = 0; n < next_ptr; n++) {
254         if (ptr != table[n].new_ptr) continue;
255 
256         farfree(table[n].org_ptr);
257         while (++n < next_ptr) {
258             table[n-1] = table[n];
259         }
260         next_ptr--;
261         return;
262     }
263     Assert(0, "zcfree: ptr not found");
264 }
265 
266 #endif /* __TURBOC__ */
267 
268 
269 #ifdef M_I86
270 /* Microsoft C in 16-bit mode */
271 
272 #  define MY_ZCALLOC
273 
274 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
275 #  define _halloc  halloc
276 #  define _hfree   hfree
277 #endif
278 
279 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
280 {
281     (void)opaque;
282     return _halloc((long)items, size);
283 }
284 
285 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
286 {
287     (void)opaque;
288     _hfree(ptr);
289 }
290 
291 #endif /* M_I86 */
292 
293 #endif /* SYS16BIT */
294 
295 
296 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
297 
298 #ifndef STDC
299 extern voidp  malloc OF((uInt size));
300 extern voidp  calloc OF((uInt items, uInt size));
301 extern void   free   OF((voidpf ptr));
302 #endif
303 
304 voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
305     voidpf opaque;
306     unsigned items;
307     unsigned size;
308 {
309     (void)opaque;
310     if (items == 0 || size == 0)
311         return (NULL);
312     return reallocarray(NULL, items, size);
313 }
314 
315 void ZLIB_INTERNAL zcfree (opaque, ptr)
316     voidpf opaque;
317     voidpf ptr;
318 {
319     (void)opaque;
320     free(ptr);
321 }
322 
323 #endif /* MY_ZCALLOC */
324 
325 #endif /* !Z_SOLO */
326