xref: /openbsd/lib/libz/gzguts.h (revision d62e7792)
1 /* gzguts.h -- zlib internal header definitions for gz* operations
2  * Copyright (C) 2004-2024 Mark Adler
3  * For conditions of distribution and use, see copyright notice in zlib.h
4  */
5 
6 #ifdef _LARGEFILE64_SOURCE
7 #  ifndef _LARGEFILE_SOURCE
8 #    define _LARGEFILE_SOURCE 1
9 #  endif
10 #  undef _FILE_OFFSET_BITS
11 #  undef _TIME_BITS
12 #endif
13 
14 #ifdef HAVE_HIDDEN
15 #  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
16 #else
17 #  define ZLIB_INTERNAL
18 #endif
19 
20 #if defined(_WIN32)
21 #  ifndef WIN32_LEAN_AND_MEAN
22 #    define WIN32_LEAN_AND_MEAN
23 #  endif
24 #  ifndef _CRT_SECURE_NO_WARNINGS
25 #    define _CRT_SECURE_NO_WARNINGS
26 #  endif
27 #  ifndef _CRT_NONSTDC_NO_DEPRECATE
28 #    define _CRT_NONSTDC_NO_DEPRECATE
29 #  endif
30 #endif
31 
32 #include <stdio.h>
33 #include "zlib.h"
34 #ifdef STDC
35 #  include <string.h>
36 #  include <stdlib.h>
37 #  include <limits.h>
38 #endif
39 
40 #ifndef _POSIX_C_SOURCE
41 #  define _POSIX_C_SOURCE 200112L
42 #endif
43 #include <fcntl.h>
44 
45 #ifdef _WIN32
46 #  include <stddef.h>
47 #endif
48 
49 #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
50 #  include <io.h>
51 #  include <sys/stat.h>
52 #endif
53 
54 #if defined(_WIN32) && !defined(WIDECHAR)
55 #  define WIDECHAR
56 #endif
57 
58 #ifdef NO_DEFLATE       /* for compatibility with old definition */
59 #  define NO_GZCOMPRESS
60 #endif
61 
62 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
63 #  ifndef HAVE_VSNPRINTF
64 #    define HAVE_VSNPRINTF
65 #  endif
66 #endif
67 
68 #if defined(__CYGWIN__)
69 #  ifndef HAVE_VSNPRINTF
70 #    define HAVE_VSNPRINTF
71 #  endif
72 #endif
73 
74 #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
75 #  ifndef HAVE_VSNPRINTF
76 #    define HAVE_VSNPRINTF
77 #  endif
78 #endif
79 
80 #ifndef HAVE_VSNPRINTF
81 #  if !defined(NO_vsnprintf) && \
82       (defined(MSDOS) || defined(__TURBOC__) || defined(__SASC) || \
83        defined(VMS) || defined(__OS400) || defined(__MVS__))
84 /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
85    but for now we just assume it doesn't. */
86 #    define NO_vsnprintf
87 #  endif
88 #  ifdef WIN32
89 /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
90 #    if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
91 #      ifndef vsnprintf
92 #        define vsnprintf _vsnprintf
93 #      endif
94 #    endif
95 #  elif !defined(__STDC_VERSION__) || __STDC_VERSION__-0 < 199901L
96 /* Otherwise if C89/90, assume no C99 snprintf() or vsnprintf() */
97 #    ifndef NO_snprintf
98 #      define NO_snprintf
99 #    endif
100 #    ifndef NO_vsnprintf
101 #      define NO_vsnprintf
102 #    endif
103 #  endif
104 #endif
105 
106 /* unlike snprintf (which is required in C99), _snprintf does not guarantee
107    null termination of the result -- however this is only used in gzlib.c where
108    the result is assured to fit in the space provided */
109 #if defined(_MSC_VER) && _MSC_VER < 1900
110 #  define snprintf _snprintf
111 #endif
112 
113 #ifndef local
114 #  define local static
115 #endif
116 /* since "static" is used to mean two completely different things in C, we
117    define "local" for the non-static meaning of "static", for readability
118    (compile with -Dlocal if your debugger can't find static symbols) */
119 
120 /* gz* functions always use library allocation functions */
121 #ifndef STDC
122   extern voidp  malloc(uInt size);
123   extern void   free(voidpf ptr);
124 #endif
125 
126 /* get errno and strerror definition */
127 #if defined UNDER_CE
128 #  include <windows.h>
129 #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
130 #else
131 #  ifndef NO_STRERROR
132 #    include <errno.h>
133 #    define zstrerror() strerror(errno)
134 #  else
135 #    define zstrerror() "stdio error (consult errno)"
136 #  endif
137 #endif
138 
139 /* provide prototypes for these when building zlib without LFS */
140 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
141     ZEXTERN gzFile ZEXPORT gzopen64(const char *, const char *);
142     ZEXTERN z_off64_t ZEXPORT gzseek64(gzFile, z_off64_t, int);
143     ZEXTERN z_off64_t ZEXPORT gztell64(gzFile);
144     ZEXTERN z_off64_t ZEXPORT gzoffset64(gzFile);
145 #endif
146 
147 /* default memLevel */
148 #if MAX_MEM_LEVEL >= 8
149 #  define DEF_MEM_LEVEL 8
150 #else
151 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
152 #endif
153 
154 /* default i/o buffer size -- double this for output when reading (this and
155    twice this must be able to fit in an unsigned type) */
156 #define GZBUFSIZE 8192
157 
158 /* gzip modes, also provide a little integrity check on the passed structure */
159 #define GZ_NONE 0
160 #define GZ_READ 7247
161 #define GZ_WRITE 31153
162 #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
163 
164 /* values for gz_state how */
165 #define LOOK 0      /* look for a gzip header */
166 #define COPY 1      /* copy input directly */
167 #define GZIP 2      /* decompress a gzip stream */
168 
169 /* internal gzip file state data structure */
170 typedef struct {
171         /* exposed contents for gzgetc() macro */
172     struct gzFile_s x;      /* "x" for exposed */
173                             /* x.have: number of bytes available at x.next */
174                             /* x.next: next output data to deliver or write */
175                             /* x.pos: current position in uncompressed data */
176         /* used for both reading and writing */
177     int mode;               /* see gzip modes above */
178     int fd;                 /* file descriptor */
179     char *path;             /* path or fd for error messages */
180     unsigned size;          /* buffer size, zero if not allocated yet */
181     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
182     unsigned char *in;      /* input buffer (double-sized when writing) */
183     unsigned char *out;     /* output buffer (double-sized when reading) */
184     int direct;             /* 0 if processing gzip, 1 if transparent */
185         /* just for reading */
186     int how;                /* 0: get header, 1: copy, 2: decompress */
187     z_off64_t start;        /* where the gzip data started, for rewinding */
188     int eof;                /* true if end of input file reached */
189     int past;               /* true if read requested past end */
190         /* just for writing */
191     int level;              /* compression level */
192     int strategy;           /* compression strategy */
193     int reset;              /* true if a reset is pending after a Z_FINISH */
194         /* seek request */
195     z_off64_t skip;         /* amount to skip (already rewound if backwards) */
196     int seek;               /* true if seek request pending */
197         /* error information */
198     int err;                /* error code */
199     char *msg;              /* error message */
200         /* zlib inflate or deflate stream */
201     z_stream strm;          /* stream structure in-place (not a pointer) */
202 } gz_state;
203 typedef gz_state FAR *gz_statep;
204 
205 /* shared functions */
206 void ZLIB_INTERNAL gz_error(gz_statep, int, const char *);
207 #if defined UNDER_CE
208 char ZLIB_INTERNAL *gz_strwinerror(DWORD error);
209 #endif
210 
211 /* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
212    value -- needed when comparing unsigned to z_off64_t, which is signed
213    (possible z_off64_t types off_t, off64_t, and long are all signed) */
214 unsigned ZLIB_INTERNAL gz_intmax(void);
215 #define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
216