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 "zbuild.h"
7 #include "zutil_p.h"
8 #include "zutil.h"
9 
10 z_const char * const PREFIX(z_errmsg)[10] = {
11     (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
12     (z_const char *)"stream end",          /* Z_STREAM_END      1  */
13     (z_const char *)"",                    /* Z_OK              0  */
14     (z_const char *)"file error",          /* Z_ERRNO         (-1) */
15     (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
16     (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
17     (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
18     (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
19     (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
20     (z_const char *)""
21 };
22 
23 const char zlibng_string[] =
24     " zlib-ng 2.1.0.devel forked from zlib";
25 
26 #ifdef ZLIB_COMPAT
zlibVersion(void)27 const char * Z_EXPORT zlibVersion(void) {
28     return ZLIB_VERSION;
29 }
30 #endif
31 
zlibng_version(void)32 const char * Z_EXPORT zlibng_version(void) {
33     return ZLIBNG_VERSION;
34 }
35 
PREFIX(zlibCompileFlags)36 unsigned long Z_EXPORT PREFIX(zlibCompileFlags)(void) {
37     unsigned long flags;
38 
39     flags = 0;
40     switch ((int)(sizeof(unsigned int))) {
41     case 2:     break;
42     case 4:     flags += 1;     break;
43     case 8:     flags += 2;     break;
44     default:    flags += 3;
45     }
46     switch ((int)(sizeof(unsigned long))) {
47     case 2:     break;
48     case 4:     flags += 1 << 2;        break;
49     case 8:     flags += 2 << 2;        break;
50     default:    flags += 3 << 2;
51     }
52     switch ((int)(sizeof(void *))) {
53     case 2:     break;
54     case 4:     flags += 1 << 4;        break;
55     case 8:     flags += 2 << 4;        break;
56     default:    flags += 3 << 4;
57     }
58     switch ((int)(sizeof(z_off_t))) {
59     case 2:     break;
60     case 4:     flags += 1 << 6;        break;
61     case 8:     flags += 2 << 6;        break;
62     default:    flags += 3 << 6;
63     }
64 #ifdef ZLIB_DEBUG
65     flags += 1 << 8;
66 #endif
67 #ifdef ZLIB_WINAPI
68     flags += 1 << 10;
69 #endif
70     /* Bit 13 reserved for DYNAMIC_CRC_TABLE */
71 #ifdef NO_GZCOMPRESS
72     flags += 1L << 16;
73 #endif
74 #ifdef NO_GZIP
75     flags += 1L << 17;
76 #endif
77 #ifdef PKZIP_BUG_WORKAROUND
78     flags += 1L << 20;
79 #endif
80     return flags;
81 }
82 
83 #ifdef ZLIB_DEBUG
84 #  include <stdlib.h>
85 #  ifndef verbose
86 #    define verbose 0
87 #  endif
88 int Z_INTERNAL z_verbose = verbose;
89 
z_error(char * m)90 void Z_INTERNAL z_error(char *m) {
91     fprintf(stderr, "%s\n", m);
92     exit(1);
93 }
94 #endif
95 
96 /* exported to allow conversion of error code to string for compress() and
97  * uncompress()
98  */
PREFIX(zError)99 const char * Z_EXPORT PREFIX(zError)(int err) {
100     return ERR_MSG(err);
101 }
102 
zng_calloc(void * opaque,unsigned items,unsigned size)103 void Z_INTERNAL *zng_calloc(void *opaque, unsigned items, unsigned size) {
104     Z_UNUSED(opaque);
105     return zng_alloc((size_t)items * (size_t)size);
106 }
107 
zng_cfree(void * opaque,void * ptr)108 void Z_INTERNAL zng_cfree(void *opaque, void *ptr) {
109     Z_UNUSED(opaque);
110     zng_free(ptr);
111 }
112 
113 /* Since we support custom memory allocators, some which might not align memory as we expect,
114  * we have to ask for extra memory and return an aligned pointer. */
zng_alloc_aligned(zng_calloc_func zalloc,void * opaque,unsigned items,unsigned size,unsigned align)115 void Z_INTERNAL *zng_alloc_aligned(zng_calloc_func zalloc, void *opaque, unsigned items, unsigned size, unsigned align) {
116     uintptr_t return_ptr, original_ptr;
117     uint32_t alloc_size, align_diff;
118     void *ptr;
119 
120     /* If no custom calloc function used then call zlib-ng's aligned calloc */
121     if (zalloc == zng_calloc)
122         return zng_calloc(opaque, items, size);
123 
124     /* Allocate enough memory for proper alignment and to store the original memory pointer */
125     alloc_size = sizeof(void *) + (items * size) + align;
126     ptr = zalloc(opaque, 1, alloc_size);
127     if (!ptr)
128         return NULL;
129 
130     /* Calculate return pointer address with space enough to store original pointer */
131     align_diff = align - ((uintptr_t)ptr % align);
132     return_ptr = (uintptr_t)ptr + align_diff;
133     if (align_diff < sizeof(void *))
134         return_ptr += align;
135 
136     /* Store the original pointer for free() */
137     original_ptr = return_ptr - sizeof(void *);
138     memcpy((void *)original_ptr, &ptr, sizeof(void *));
139 
140     /* Return properly aligned pointer in allocation */
141     return (void *)return_ptr;
142 }
143 
zng_free_aligned(zng_cfree_func zfree,void * opaque,void * ptr)144 void Z_INTERNAL zng_free_aligned(zng_cfree_func zfree, void *opaque, void *ptr) {
145     /* If no custom cfree function used then call zlib-ng's aligned cfree */
146     if (zfree == zng_cfree) {
147         zng_cfree(opaque, ptr);
148         return;
149     }
150     if (!ptr)
151         return;
152 
153     /* Calculate offset to original memory allocation pointer */
154     void *original_ptr = (void *)((uintptr_t)ptr - sizeof(void *));
155     void *free_ptr = *(void **)original_ptr;
156 
157     /* Free original memory allocation */
158     zfree(opaque, free_ptr);
159 }
160