xref: /freebsd/sys/contrib/zlib/gzguts.h (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
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 #include <stdio.h>
21 #include "zlib.h"
22 #ifdef STDC
23 #  include <string.h>
24 #  include <stdlib.h>
25 #  include <limits.h>
26 #endif
27 
28 #ifndef _POSIX_SOURCE
29 #  define _POSIX_SOURCE
30 #endif
31 #include <fcntl.h>
32 
33 #ifdef _WIN32
34 #  include <stddef.h>
35 #endif
36 
37 #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
38 #  include <io.h>
39 #endif
40 
41 #if defined(_WIN32)
42 #  define WIDECHAR
43 #endif
44 
45 #ifdef WINAPI_FAMILY
46 #  define open _open
47 #  define read _read
48 #  define write _write
49 #  define close _close
50 #endif
51 
52 #ifdef NO_DEFLATE       /* for compatibility with old definition */
53 #  define NO_GZCOMPRESS
54 #endif
55 
56 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
57 #  ifndef HAVE_VSNPRINTF
58 #    define HAVE_VSNPRINTF
59 #  endif
60 #endif
61 
62 #if defined(__CYGWIN__)
63 #  ifndef HAVE_VSNPRINTF
64 #    define HAVE_VSNPRINTF
65 #  endif
66 #endif
67 
68 #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
69 #  ifndef HAVE_VSNPRINTF
70 #    define HAVE_VSNPRINTF
71 #  endif
72 #endif
73 
74 #ifndef HAVE_VSNPRINTF
75 #  ifdef MSDOS
76 /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
77    but for now we just assume it doesn't. */
78 #    define NO_vsnprintf
79 #  endif
80 #  ifdef __TURBOC__
81 #    define NO_vsnprintf
82 #  endif
83 #  ifdef WIN32
84 /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
85 #    if !defined(vsnprintf) && !defined(NO_vsnprintf)
86 #      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
87 #         define vsnprintf _vsnprintf
88 #      endif
89 #    endif
90 #  endif
91 #  ifdef __SASC
92 #    define NO_vsnprintf
93 #  endif
94 #  ifdef VMS
95 #    define NO_vsnprintf
96 #  endif
97 #  ifdef __OS400__
98 #    define NO_vsnprintf
99 #  endif
100 #  ifdef __MVS__
101 #    define NO_vsnprintf
102 #  endif
103 #endif
104 
105 /* unlike snprintf (which is required in C99), _snprintf does not guarantee
106    null termination of the result -- however this is only used in gzlib.c where
107    the result is assured to fit in the space provided */
108 #if defined(_MSC_VER) && _MSC_VER < 1900
109 #  define snprintf _snprintf
110 #endif
111 
112 #ifndef local
113 #  define local static
114 #endif
115 /* since "static" is used to mean two completely different things in C, we
116    define "local" for the non-static meaning of "static", for readability
117    (compile with -Dlocal if your debugger can't find static symbols) */
118 
119 /* gz* functions always use library allocation functions */
120 #ifndef STDC
121   extern voidp  malloc(uInt size);
122   extern void   free(voidpf ptr);
123 #endif
124 
125 /* get errno and strerror definition */
126 #if defined UNDER_CE
127 #  include <windows.h>
128 #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
129 #else
130 #  ifndef NO_STRERROR
131 #    include <errno.h>
132 #    define zstrerror() strerror(errno)
133 #  else
134 #    define zstrerror() "stdio error (consult errno)"
135 #  endif
136 #endif
137 
138 /* provide prototypes for these when building zlib without LFS */
139 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
140     ZEXTERN gzFile ZEXPORT gzopen64(const char *, const char *);
141     ZEXTERN z_off64_t ZEXPORT gzseek64(gzFile, z_off64_t, int);
142     ZEXTERN z_off64_t ZEXPORT gztell64(gzFile);
143     ZEXTERN z_off64_t ZEXPORT gzoffset64(gzFile);
144 #endif
145 
146 /* default memLevel */
147 #if MAX_MEM_LEVEL >= 8
148 #  define DEF_MEM_LEVEL 8
149 #else
150 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
151 #endif
152 
153 /* default i/o buffer size -- double this for output when reading (this and
154    twice this must be able to fit in an unsigned type) */
155 #define GZBUFSIZE 8192
156 
157 /* gzip modes, also provide a little integrity check on the passed structure */
158 #define GZ_NONE 0
159 #define GZ_READ 7247
160 #define GZ_WRITE 31153
161 #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
162 
163 /* values for gz_state how */
164 #define LOOK 0      /* look for a gzip header */
165 #define COPY 1      /* copy input directly */
166 #define GZIP 2      /* decompress a gzip stream */
167 
168 /* internal gzip file state data structure */
169 typedef struct {
170         /* exposed contents for gzgetc() macro */
171     struct gzFile_s x;      /* "x" for exposed */
172                             /* x.have: number of bytes available at x.next */
173                             /* x.next: next output data to deliver or write */
174                             /* x.pos: current position in uncompressed data */
175         /* used for both reading and writing */
176     int mode;               /* see gzip modes above */
177     int fd;                 /* file descriptor */
178     char *path;             /* path or fd for error messages */
179     unsigned size;          /* buffer size, zero if not allocated yet */
180     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
181     unsigned char *in;      /* input buffer (double-sized when writing) */
182     unsigned char *out;     /* output buffer (double-sized when reading) */
183     int direct;             /* 0 if processing gzip, 1 if transparent */
184         /* just for reading */
185     int how;                /* 0: get header, 1: copy, 2: decompress */
186     z_off64_t start;        /* where the gzip data started, for rewinding */
187     int eof;                /* true if end of input file reached */
188     int past;               /* true if read requested past end */
189         /* just for writing */
190     int level;              /* compression level */
191     int strategy;           /* compression strategy */
192     int reset;              /* true if a reset is pending after a Z_FINISH */
193         /* seek request */
194     z_off64_t skip;         /* amount to skip (already rewound if backwards) */
195     int seek;               /* true if seek request pending */
196         /* error information */
197     int err;                /* error code */
198     char *msg;              /* error message */
199         /* zlib inflate or deflate stream */
200     z_stream strm;          /* stream structure in-place (not a pointer) */
201 } gz_state;
202 typedef gz_state FAR *gz_statep;
203 
204 /* shared functions */
205 void ZLIB_INTERNAL gz_error(gz_statep, int, const char *);
206 #if defined UNDER_CE
207 char ZLIB_INTERNAL *gz_strwinerror(DWORD error);
208 #endif
209 
210 /* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
211    value -- needed when comparing unsigned to z_off64_t, which is signed
212    (possible z_off64_t types off_t, off64_t, and long are all signed) */
213 unsigned ZLIB_INTERNAL gz_intmax(void);
214 #define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
215