xref: /openbsd-src/lib/libz/zutil.c (revision a04ea15dafe6974ae5a5b91b1adc9d00183fc2e9)
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 #ifndef Z_SOLO
8 #  include "gzguts.h"
9 #endif
10 
11 z_const char * const z_errmsg[10] = {
12     (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
13     (z_const char *)"stream end",          /* Z_STREAM_END      1  */
14     (z_const char *)"",                    /* Z_OK              0  */
15     (z_const char *)"file error",          /* Z_ERRNO         (-1) */
16     (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
17     (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
18     (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
19     (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
20     (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
21     (z_const char *)""
22 };
23 
24 
zlibVersion(void)25 const char * ZEXPORT zlibVersion(void) {
26     return ZLIB_VERSION;
27 }
28 
zlibCompileFlags(void)29 uLong ZEXPORT zlibCompileFlags(void) {
30     uLong flags;
31 
32     flags = 0;
33     switch ((int)(sizeof(uInt))) {
34     case 2:     break;
35     case 4:     flags += 1;     break;
36     case 8:     flags += 2;     break;
37     default:    flags += 3;
38     }
39     switch ((int)(sizeof(uLong))) {
40     case 2:     break;
41     case 4:     flags += 1 << 2;        break;
42     case 8:     flags += 2 << 2;        break;
43     default:    flags += 3 << 2;
44     }
45     switch ((int)(sizeof(voidpf))) {
46     case 2:     break;
47     case 4:     flags += 1 << 4;        break;
48     case 8:     flags += 2 << 4;        break;
49     default:    flags += 3 << 4;
50     }
51     switch ((int)(sizeof(z_off_t))) {
52     case 2:     break;
53     case 4:     flags += 1 << 6;        break;
54     case 8:     flags += 2 << 6;        break;
55     default:    flags += 3 << 6;
56     }
57 #ifdef ZLIB_DEBUG
58     flags += 1 << 8;
59 #endif
60     /*
61 #if defined(ASMV) || defined(ASMINF)
62     flags += 1 << 9;
63 #endif
64      */
65 #ifdef ZLIB_WINAPI
66     flags += 1 << 10;
67 #endif
68 #ifdef BUILDFIXED
69     flags += 1 << 12;
70 #endif
71 #ifdef DYNAMIC_CRC_TABLE
72     flags += 1 << 13;
73 #endif
74 #ifdef NO_GZCOMPRESS
75     flags += 1L << 16;
76 #endif
77 #ifdef NO_GZIP
78     flags += 1L << 17;
79 #endif
80 #ifdef PKZIP_BUG_WORKAROUND
81     flags += 1L << 20;
82 #endif
83 #ifdef FASTEST
84     flags += 1L << 21;
85 #endif
86 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
87 #  ifdef NO_vsnprintf
88     flags += 1L << 25;
89 #    ifdef HAS_vsprintf_void
90     flags += 1L << 26;
91 #    endif
92 #  else
93 #    ifdef HAS_vsnprintf_void
94     flags += 1L << 26;
95 #    endif
96 #  endif
97 #else
98     flags += 1L << 24;
99 #  ifdef NO_snprintf
100     flags += 1L << 25;
101 #    ifdef HAS_sprintf_void
102     flags += 1L << 26;
103 #    endif
104 #  else
105 #    ifdef HAS_snprintf_void
106     flags += 1L << 26;
107 #    endif
108 #  endif
109 #endif
110     return flags;
111 }
112 
113 #ifdef ZLIB_DEBUG
114 #include <stdlib.h>
115 #  ifndef verbose
116 #    define verbose 0
117 #  endif
118 int ZLIB_INTERNAL z_verbose = verbose;
119 
z_error(char * m)120 void ZLIB_INTERNAL z_error(char *m) {
121     fprintf(stderr, "%s\n", m);
122     exit(1);
123 }
124 #endif
125 
126 /* exported to allow conversion of error code to string for compress() and
127  * uncompress()
128  */
zError(int err)129 const char * ZEXPORT zError(int err) {
130     return ERR_MSG(err);
131 }
132 
133 #if defined(_WIN32_WCE) && _WIN32_WCE < 0x800
134     /* The older Microsoft C Run-Time Library for Windows CE doesn't have
135      * errno.  We define it as a global variable to simplify porting.
136      * Its value is always 0 and should not be used.
137      */
138     int errno = 0;
139 #endif
140 
141 #ifndef HAVE_MEMCPY
142 
zmemcpy(Bytef * dest,const Bytef * source,uInt len)143 void ZLIB_INTERNAL zmemcpy(Bytef* dest, const Bytef* source, uInt len) {
144     if (len == 0) return;
145     do {
146         *dest++ = *source++; /* ??? to be unrolled */
147     } while (--len != 0);
148 }
149 
zmemcmp(const Bytef * s1,const Bytef * s2,uInt len)150 int ZLIB_INTERNAL zmemcmp(const Bytef* s1, const Bytef* s2, uInt len) {
151     uInt j;
152 
153     for (j = 0; j < len; j++) {
154         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
155     }
156     return 0;
157 }
158 
zmemzero(Bytef * dest,uInt len)159 void ZLIB_INTERNAL zmemzero(Bytef* dest, uInt len) {
160     if (len == 0) return;
161     do {
162         *dest++ = 0;  /* ??? to be unrolled */
163     } while (--len != 0);
164 }
165 #endif
166 
167 #ifndef Z_SOLO
168 
169 #ifdef SYS16BIT
170 
171 #ifdef __TURBOC__
172 /* Turbo C in 16-bit mode */
173 
174 #  define MY_ZCALLOC
175 
176 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
177  * and farmalloc(64K) returns a pointer with an offset of 8, so we
178  * must fix the pointer. Warning: the pointer must be put back to its
179  * original form in order to free it, use zcfree().
180  */
181 
182 #define MAX_PTR 10
183 /* 10*64K = 640K */
184 
185 local int next_ptr = 0;
186 
187 typedef struct ptr_table_s {
188     voidpf org_ptr;
189     voidpf new_ptr;
190 } ptr_table;
191 
192 local ptr_table table[MAX_PTR];
193 /* This table is used to remember the original form of pointers
194  * to large buffers (64K). Such pointers are normalized with a zero offset.
195  * Since MSDOS is not a preemptive multitasking OS, this table is not
196  * protected from concurrent access. This hack doesn't work anyway on
197  * a protected system like OS/2. Use Microsoft C instead.
198  */
199 
zcalloc(voidpf opaque,unsigned items,unsigned size)200 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
201     voidpf buf;
202     ulg bsize = (ulg)items*size;
203 
204     (void)opaque;
205 
206     /* If we allocate less than 65520 bytes, we assume that farmalloc
207      * will return a usable pointer which doesn't have to be normalized.
208      */
209     if (bsize < 65520L) {
210         buf = farmalloc(bsize);
211         if (*(ush*)&buf != 0) return buf;
212     } else {
213         buf = farmalloc(bsize + 16L);
214     }
215     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
216     table[next_ptr].org_ptr = buf;
217 
218     /* Normalize the pointer to seg:0 */
219     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
220     *(ush*)&buf = 0;
221     table[next_ptr++].new_ptr = buf;
222     return buf;
223 }
224 
zcfree(voidpf opaque,voidpf ptr)225 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
226     int n;
227 
228     (void)opaque;
229 
230     if (*(ush*)&ptr != 0) { /* object < 64K */
231         farfree(ptr);
232         return;
233     }
234     /* Find the original pointer */
235     for (n = 0; n < next_ptr; n++) {
236         if (ptr != table[n].new_ptr) continue;
237 
238         farfree(table[n].org_ptr);
239         while (++n < next_ptr) {
240             table[n-1] = table[n];
241         }
242         next_ptr--;
243         return;
244     }
245     Assert(0, "zcfree: ptr not found");
246 }
247 
248 #endif /* __TURBOC__ */
249 
250 
251 #ifdef M_I86
252 /* Microsoft C in 16-bit mode */
253 
254 #  define MY_ZCALLOC
255 
256 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
257 #  define _halloc  halloc
258 #  define _hfree   hfree
259 #endif
260 
zcalloc(voidpf opaque,uInt items,uInt size)261 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size) {
262     (void)opaque;
263     return _halloc((long)items, size);
264 }
265 
zcfree(voidpf opaque,voidpf ptr)266 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
267     (void)opaque;
268     _hfree(ptr);
269 }
270 
271 #endif /* M_I86 */
272 
273 #endif /* SYS16BIT */
274 
275 
276 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
277 
278 #ifndef STDC
279 extern voidp malloc(uInt size);
280 extern voidp calloc(uInt items, uInt size);
281 extern void free(voidpf ptr);
282 #endif
283 
zcalloc(voidpf opaque,unsigned items,unsigned size)284 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
285     (void)opaque;
286     if (items == 0 || size == 0)
287         return (NULL);
288     return reallocarray(NULL, items, size);
289 }
290 
zcfree(voidpf opaque,voidpf ptr)291 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
292     (void)opaque;
293     free(ptr);
294 }
295 
296 #endif /* MY_ZCALLOC */
297 
298 #endif /* !Z_SOLO */
299