xref: /openbsd/sys/lib/libz/zutil.c (revision 4bdff4be)
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 #include "zutil.h"
7 
8 #ifndef _KERNEL
9 #ifndef Z_SOLO
10 #  include "gzguts.h"
11 #endif
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 
28 const char * ZEXPORT zlibVersion(void) {
29     return ZLIB_VERSION;
30 }
31 
32 uLong ZEXPORT zlibCompileFlags(void) {
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     /*
64 #if defined(ASMV) || defined(ASMINF)
65     flags += 1 << 9;
66 #endif
67      */
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 
123 void ZLIB_INTERNAL z_error(char *m) {
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(int err) {
133     return ERR_MSG(err);
134 }
135 
136 #if defined(_WIN32_WCE) && _WIN32_WCE < 0x800
137     /* The older Microsoft C Run-Time Library for Windows CE doesn't have
138      * errno.  We define it as a global variable to simplify porting.
139      * Its value is always 0 and should not be used.
140      */
141     int errno = 0;
142 #endif
143 
144 #ifndef HAVE_MEMCPY
145 
146 void ZLIB_INTERNAL zmemcpy(Bytef* dest, const Bytef* source, uInt len) {
147     if (len == 0) return;
148     do {
149         *dest++ = *source++; /* ??? to be unrolled */
150     } while (--len != 0);
151 }
152 
153 int ZLIB_INTERNAL zmemcmp(const Bytef* s1, const Bytef* s2, uInt len) {
154     uInt j;
155 
156     for (j = 0; j < len; j++) {
157         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
158     }
159     return 0;
160 }
161 
162 void ZLIB_INTERNAL zmemzero(Bytef* dest, uInt len) {
163     if (len == 0) return;
164     do {
165         *dest++ = 0;  /* ??? to be unrolled */
166     } while (--len != 0);
167 }
168 #endif
169 
170 #ifndef Z_SOLO
171 
172 #ifdef SYS16BIT
173 
174 #ifdef __TURBOC__
175 /* Turbo C in 16-bit mode */
176 
177 #  define MY_ZCALLOC
178 
179 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
180  * and farmalloc(64K) returns a pointer with an offset of 8, so we
181  * must fix the pointer. Warning: the pointer must be put back to its
182  * original form in order to free it, use zcfree().
183  */
184 
185 #define MAX_PTR 10
186 /* 10*64K = 640K */
187 
188 local int next_ptr = 0;
189 
190 typedef struct ptr_table_s {
191     voidpf org_ptr;
192     voidpf new_ptr;
193 } ptr_table;
194 
195 local ptr_table table[MAX_PTR];
196 /* This table is used to remember the original form of pointers
197  * to large buffers (64K). Such pointers are normalized with a zero offset.
198  * Since MSDOS is not a preemptive multitasking OS, this table is not
199  * protected from concurrent access. This hack doesn't work anyway on
200  * a protected system like OS/2. Use Microsoft C instead.
201  */
202 
203 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
204     voidpf buf;
205     ulg bsize = (ulg)items*size;
206 
207     (void)opaque;
208 
209     /* If we allocate less than 65520 bytes, we assume that farmalloc
210      * will return a usable pointer which doesn't have to be normalized.
211      */
212     if (bsize < 65520L) {
213         buf = farmalloc(bsize);
214         if (*(ush*)&buf != 0) return buf;
215     } else {
216         buf = farmalloc(bsize + 16L);
217     }
218     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
219     table[next_ptr].org_ptr = buf;
220 
221     /* Normalize the pointer to seg:0 */
222     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
223     *(ush*)&buf = 0;
224     table[next_ptr++].new_ptr = buf;
225     return buf;
226 }
227 
228 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
229     int n;
230 
231     (void)opaque;
232 
233     if (*(ush*)&ptr != 0) { /* object < 64K */
234         farfree(ptr);
235         return;
236     }
237     /* Find the original pointer */
238     for (n = 0; n < next_ptr; n++) {
239         if (ptr != table[n].new_ptr) continue;
240 
241         farfree(table[n].org_ptr);
242         while (++n < next_ptr) {
243             table[n-1] = table[n];
244         }
245         next_ptr--;
246         return;
247     }
248     Assert(0, "zcfree: ptr not found");
249 }
250 
251 #endif /* __TURBOC__ */
252 
253 
254 #ifdef M_I86
255 /* Microsoft C in 16-bit mode */
256 
257 #  define MY_ZCALLOC
258 
259 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
260 #  define _halloc  halloc
261 #  define _hfree   hfree
262 #endif
263 
264 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size) {
265     (void)opaque;
266     return _halloc((long)items, size);
267 }
268 
269 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
270     (void)opaque;
271     _hfree(ptr);
272 }
273 
274 #endif /* M_I86 */
275 
276 #endif /* SYS16BIT */
277 
278 
279 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
280 
281 #ifndef STDC
282 extern voidp malloc(uInt size);
283 extern voidp calloc(uInt items, uInt size);
284 extern void free(voidpf ptr);
285 #endif
286 
287 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
288     (void)opaque;
289     if (items == 0 || size == 0)
290         return (NULL);
291     return reallocarray(NULL, 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