xref: /openbsd-src/lib/libz/gzguts.h (revision 4e1ee0786f11cc571bd0be17d38e46f635c719fc)
1 /*	$OpenBSD: gzguts.h,v 1.2 2021/07/04 17:41:23 tb Exp $ */
2 
3 /* gzguts.h -- zlib internal header definitions for gz* operations
4  * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
5  * For conditions of distribution and use, see copyright notice in zlib.h
6  */
7 
8 #ifdef _LARGEFILE64_SOURCE
9 #  ifndef _LARGEFILE_SOURCE
10 #    define _LARGEFILE_SOURCE 1
11 #  endif
12 #  ifdef _FILE_OFFSET_BITS
13 #    undef _FILE_OFFSET_BITS
14 #  endif
15 #endif
16 
17 #ifdef HAVE_HIDDEN
18 #  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
19 #else
20 #  define ZLIB_INTERNAL
21 #endif
22 
23 #include <stdio.h>
24 #include "zlib.h"
25 #ifdef STDC
26 #  include <string.h>
27 #  include <stdlib.h>
28 #  include <limits.h>
29 #endif
30 
31 #ifndef _POSIX_SOURCE
32 #  define _POSIX_SOURCE
33 #endif
34 #include <fcntl.h>
35 
36 #ifdef _WIN32
37 #  include <stddef.h>
38 #endif
39 
40 #if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
41 #  include <io.h>
42 #endif
43 
44 #if defined(_WIN32) || defined(__CYGWIN__)
45 #  define WIDECHAR
46 #endif
47 
48 #ifdef WINAPI_FAMILY
49 #  define open _open
50 #  define read _read
51 #  define write _write
52 #  define close _close
53 #endif
54 
55 #ifdef NO_DEFLATE       /* for compatibility with old definition */
56 #  define NO_GZCOMPRESS
57 #endif
58 
59 #if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
60 #  ifndef HAVE_VSNPRINTF
61 #    define HAVE_VSNPRINTF
62 #  endif
63 #endif
64 
65 #if defined(__CYGWIN__)
66 #  ifndef HAVE_VSNPRINTF
67 #    define HAVE_VSNPRINTF
68 #  endif
69 #endif
70 
71 #if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
72 #  ifndef HAVE_VSNPRINTF
73 #    define HAVE_VSNPRINTF
74 #  endif
75 #endif
76 
77 #ifndef HAVE_VSNPRINTF
78 #  ifdef MSDOS
79 /* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
80    but for now we just assume it doesn't. */
81 #    define NO_vsnprintf
82 #  endif
83 #  ifdef __TURBOC__
84 #    define NO_vsnprintf
85 #  endif
86 #  ifdef WIN32
87 /* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
88 #    if !defined(vsnprintf) && !defined(NO_vsnprintf)
89 #      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
90 #         define vsnprintf _vsnprintf
91 #      endif
92 #    endif
93 #  endif
94 #  ifdef __SASC
95 #    define NO_vsnprintf
96 #  endif
97 #  ifdef VMS
98 #    define NO_vsnprintf
99 #  endif
100 #  ifdef __OS400__
101 #    define NO_vsnprintf
102 #  endif
103 #  ifdef __MVS__
104 #    define NO_vsnprintf
105 #  endif
106 #endif
107 
108 /* unlike snprintf (which is required in C99), _snprintf does not guarantee
109    null termination of the result -- however this is only used in gzlib.c where
110    the result is assured to fit in the space provided */
111 #if defined(_MSC_VER) && _MSC_VER < 1900
112 #  define snprintf _snprintf
113 #endif
114 
115 #ifndef local
116 #  define local static
117 #endif
118 /* since "static" is used to mean two completely different things in C, we
119    define "local" for the non-static meaning of "static", for readability
120    (compile with -Dlocal if your debugger can't find static symbols) */
121 
122 /* gz* functions always use library allocation functions */
123 #ifndef STDC
124   extern voidp  malloc OF((uInt size));
125   extern void   free   OF((voidpf ptr));
126 #endif
127 
128 /* get errno and strerror definition */
129 #if defined UNDER_CE
130 #  include <windows.h>
131 #  define zstrerror() gz_strwinerror((DWORD)GetLastError())
132 #else
133 #  ifndef NO_STRERROR
134 #    include <errno.h>
135 #    define zstrerror() strerror(errno)
136 #  else
137 #    define zstrerror() "stdio error (consult errno)"
138 #  endif
139 #endif
140 
141 /* provide prototypes for these when building zlib without LFS */
142 #if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
143     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
144     ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
145     ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
146     ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
147 #endif
148 
149 /* default memLevel */
150 #if MAX_MEM_LEVEL >= 8
151 #  define DEF_MEM_LEVEL 8
152 #else
153 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
154 #endif
155 
156 /* default i/o buffer size -- double this for output when reading (this and
157    twice this must be able to fit in an unsigned type) */
158 #define GZBUFSIZE 8192
159 
160 /* gzip modes, also provide a little integrity check on the passed structure */
161 #define GZ_NONE 0
162 #define GZ_READ 7247
163 #define GZ_WRITE 31153
164 #define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
165 
166 /* values for gz_state how */
167 #define LOOK 0      /* look for a gzip header */
168 #define COPY 1      /* copy input directly */
169 #define GZIP 2      /* decompress a gzip stream */
170 
171 /* internal gzip file state data structure */
172 typedef struct {
173         /* exposed contents for gzgetc() macro */
174     struct gzFile_s x;      /* "x" for exposed */
175                             /* x.have: number of bytes available at x.next */
176                             /* x.next: next output data to deliver or write */
177                             /* x.pos: current position in uncompressed data */
178         /* used for both reading and writing */
179     int mode;               /* see gzip modes above */
180     int fd;                 /* file descriptor */
181     char *path;             /* path or fd for error messages */
182     unsigned size;          /* buffer size, zero if not allocated yet */
183     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
184     unsigned char *in;      /* input buffer (double-sized when writing) */
185     unsigned char *out;     /* output buffer (double-sized when reading) */
186     int direct;             /* 0 if processing gzip, 1 if transparent */
187         /* just for reading */
188     int how;                /* 0: get header, 1: copy, 2: decompress */
189     z_off64_t start;        /* where the gzip data started, for rewinding */
190     int eof;                /* true if end of input file reached */
191     int past;               /* true if read requested past end */
192         /* just for writing */
193     int level;              /* compression level */
194     int strategy;           /* compression strategy */
195         /* seek request */
196     z_off64_t skip;         /* amount to skip (already rewound if backwards) */
197     int seek;               /* true if seek request pending */
198         /* error information */
199     int err;                /* error code */
200     char *msg;              /* error message */
201         /* zlib inflate or deflate stream */
202     z_stream strm;          /* stream structure in-place (not a pointer) */
203 } gz_state;
204 typedef gz_state FAR *gz_statep;
205 
206 /* shared functions */
207 void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
208 #if defined UNDER_CE
209 char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
210 #endif
211 
212 /* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
213    value -- needed when comparing unsigned to z_off64_t, which is signed
214    (possible z_off64_t types off_t, off64_t, and long are all signed) */
215 #ifdef INT_MAX
216 #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
217 #else
218 unsigned ZLIB_INTERNAL gz_intmax OF((void));
219 #  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
220 #endif
221