1 /* SPDX-License-Identifier: Zlib */
2 /* gzguts.h -- zlib internal header definitions for gz* operations
3  * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
4  * For conditions of distribution and use, see copyright notice in zlib.h
5  */
6 
7 #ifdef _LARGEFILE64_SOURCE
8 #  ifndef _LARGEFILE_SOURCE
9 #    define _LARGEFILE_SOURCE 1
10 #  endif
11 #  ifdef _FILE_OFFSET_BITS
12 #    undef _FILE_OFFSET_BITS
13 #  endif
14 #endif
15 
16 #ifdef HAVE_HIDDEN
17 #  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
18 #else
19 #  define ZLIB_INTERNAL
20 #endif
21 
22 #include <stdio.h>
23 #include "zlib.h"
24 #ifdef STDC
25 #  include <string.h>
26 #  include <stdlib.h>
27 #  include <limits.h>
28 #endif
29 
30 #ifndef _POSIX_SOURCE
31 #  define _POSIX_SOURCE
32 #endif
33 #include <fcntl.h>
34 
35 #ifdef _WIN32
36 #  include <stddef.h>
37 #endif
38 
39 #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
40 #  include <io.h>
41 #endif
42 
43 #if defined(_WIN32) || defined(__CYGWIN__)
44 #  define WIDECHAR
45 #endif
46 
47 #ifdef WINAPI_FAMILY
48 #  define open _open
49 #  define read _read
50 #  define write _write
51 #  define close _close
52 #endif
53 
54 #ifdef NO_DEFLATE       /* for compatibility with old definition */
55 #  define NO_GZCOMPRESS
56 #endif
57 
58 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
59 #  ifndef HAVE_VSNPRINTF
60 #    define HAVE_VSNPRINTF
61 #  endif
62 #endif
63 
64 #if defined(__CYGWIN__)
65 #  ifndef HAVE_VSNPRINTF
66 #    define HAVE_VSNPRINTF
67 #  endif
68 #endif
69 
70 #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
71 #  ifndef HAVE_VSNPRINTF
72 #    define HAVE_VSNPRINTF
73 #  endif
74 #endif
75 
76 #ifndef HAVE_VSNPRINTF
77 #  ifdef MSDOS
78 /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
79    but for now we just assume it doesn't. */
80 #    define NO_vsnprintf
81 #  endif
82 #  ifdef __TURBOC__
83 #    define NO_vsnprintf
84 #  endif
85 #  ifdef WIN32
86 /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
87 #    if !defined(vsnprintf) && !defined(NO_vsnprintf)
88 #      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
89 #         define vsnprintf _vsnprintf
90 #      endif
91 #    endif
92 #  endif
93 #  ifdef __SASC
94 #    define NO_vsnprintf
95 #  endif
96 #  ifdef VMS
97 #    define NO_vsnprintf
98 #  endif
99 #  ifdef __OS400__
100 #    define NO_vsnprintf
101 #  endif
102 #  ifdef __MVS__
103 #    define NO_vsnprintf
104 #  endif
105 #endif
106 
107 /* unlike snprintf (which is required in C99), _snprintf does not guarantee
108    null termination of the result -- however this is only used in gzlib.c where
109    the result is assured to fit in the space provided */
110 #if defined(_MSC_VER) && _MSC_VER < 1900
111 #  define snprintf _snprintf
112 #endif
113 
114 #ifndef local
115 #  define local static
116 #endif
117 /* since "static" is used to mean two completely different things in C, we
118    define "local" for the non-static meaning of "static", for readability
119    (compile with -Dlocal if your debugger can't find static symbols) */
120 
121 /* gz* functions always use library allocation functions */
122 #ifndef STDC
123   extern voidp  malloc OF((uInt size));
124   extern void   free   OF((voidpf ptr));
125 #endif
126 
127 /* get errno and strerror definition */
128 #if defined UNDER_CE
129 #  include <windows.h>
130 #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
131 #else
132 #  ifndef NO_STRERROR
133 #    include <errno.h>
134 #    define zstrerror() strerror(errno)
135 #  else
136 #    define zstrerror() "stdio error (consult errno)"
137 #  endif
138 #endif
139 
140 /* provide prototypes for these when building zlib without LFS */
141 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
142     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
143     ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
144     ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
145     ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
146 #endif
147 
148 /* default memLevel */
149 #if MAX_MEM_LEVEL >= 8
150 #  define DEF_MEM_LEVEL 8
151 #else
152 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
153 #endif
154 
155 /* default i/o buffer size -- double this for output when reading (this and
156    twice this must be able to fit in an unsigned type) */
157 #define GZBUFSIZE 8192
158 
159 /* gzip modes, also provide a little integrity check on the passed structure */
160 #define GZ_NONE 0
161 #define GZ_READ 7247
162 #define GZ_WRITE 31153
163 #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
164 
165 /* values for gz_state how */
166 #define LOOK 0      /* look for a gzip header */
167 #define COPY 1      /* copy input directly */
168 #define GZIP 2      /* decompress a gzip stream */
169 
170 /* internal gzip file state data structure */
171 typedef struct {
172         /* exposed contents for gzgetc() macro */
173     struct gzFile_s x;      /* "x" for exposed */
174                             /* x.have: number of bytes available at x.next */
175                             /* x.next: next output data to deliver or write */
176                             /* x.pos: current position in uncompressed data */
177         /* used for both reading and writing */
178     int mode;               /* see gzip modes above */
179     int fd;                 /* file descriptor */
180     char *path;             /* path or fd for error messages */
181     unsigned size;          /* buffer size, zero if not allocated yet */
182     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
183     unsigned char *in;      /* input buffer (double-sized when writing) */
184     unsigned char *out;     /* output buffer (double-sized when reading) */
185     int direct;             /* 0 if processing gzip, 1 if transparent */
186         /* just for reading */
187     int how;                /* 0: get header, 1: copy, 2: decompress */
188     z_off64_t start;        /* where the gzip data started, for rewinding */
189     int eof;                /* true if end of input file reached */
190     int past;               /* true if read requested past end */
191         /* just for writing */
192     int level;              /* compression level */
193     int strategy;           /* compression strategy */
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 OF((gz_statep, int, const char *));
207 #if defined UNDER_CE
208 char ZLIB_INTERNAL *gz_strwinerror OF((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 #ifdef INT_MAX
215 #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
216 #else
217 unsigned ZLIB_INTERNAL gz_intmax OF((void));
218 #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
219 #endif
220