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1
2 #ifndef MC__VFS_TAR_INTERNAL_H
3 #define MC__VFS_TAR_INTERNAL_H
4
5 #include <inttypes.h> /* (u)intmax_t */
6 #include <limits.h> /* CHAR_BIT, INT_MAX, etc */
7 #include <sys/stat.h>
8 #include <sys/types.h>
9
10 #ifdef HAVE_STDCKDINT_H
11 #include <stdckdint.h>
12 #else
13 #include "lib/stdckdint.h"
14 #endif
15 #include "lib/intprops.h"
16 #include "lib/idx.h"
17 #include "lib/vfs/xdirentry.h" /* vfs_s_super */
18
19 /*** typedefs(not structures) and defined constants **********************************************/
20
21 /* tar files are made in basic blocks of this size. */
22 #define BLOCKSIZE 512
23
24 #define DEFAULT_BLOCKING 20
25
26 /* Sparse files are not supported in POSIX ustar format. For sparse files
27 with a POSIX header, a GNU extra header is provided which holds overall
28 sparse information and a few sparse descriptors. When an old GNU header
29 replaces both the POSIX header and the GNU extra header, it holds some
30 sparse descriptors too. Whether POSIX or not, if more sparse descriptors
31 are still needed, they are put into as many successive sparse headers as
32 necessary. The following constants tell how many sparse descriptors fit
33 in each kind of header able to hold them. */
34
35 #define SPARSES_IN_EXTRA_HEADER 16
36 #define SPARSES_IN_OLDGNU_HEADER 4
37 #define SPARSES_IN_SPARSE_HEADER 21
38
39 #define SPARSES_IN_STAR_HEADER 4
40 #define SPARSES_IN_STAR_EXT_HEADER 21
41
42 /* *BEWARE* *BEWARE* *BEWARE* that the following information is still
43 boiling, and may change. Even if the OLDGNU format description should be
44 accurate, the so-called GNU format is not yet fully decided. It is
45 surely meant to use only extensions allowed by POSIX, but the sketch
46 below repeats some ugliness from the OLDGNU format, which should rather
47 go away. Sparse files should be saved in such a way that they do *not*
48 require two passes at archive creation time. Huge files get some POSIX
49 fields to overflow, alternate solutions have to be sought for this. */
50
51 /* This is a dir entry that contains the names of files that were in the
52 dir at the time the dump was made. */
53 #define GNUTYPE_DUMPDIR 'D'
54
55 /* Identifies the *next* file on the tape as having a long linkname. */
56 #define GNUTYPE_LONGLINK 'K'
57
58 /* Identifies the *next* file on the tape as having a long name. */
59 #define GNUTYPE_LONGNAME 'L'
60
61 /* Solaris extended header */
62 #define SOLARIS_XHDTYPE 'X'
63
64 #define GNUTYPE_SPARSE 'S'
65
66
67 #define OFF_FROM_HEADER(where) off_from_header (where, sizeof (where))
68
69 /*** enums ***************************************************************************************/
70
71 /*** structures declarations (and typedefs of structures)*****************************************/
72
73 /* *INDENT-OFF* */
74
75 /* POSIX header */
76 struct posix_header
77 { /* byte offset */
78 char name[100]; /* 0 */
79 char mode[8]; /* 100 */
80 char uid[8]; /* 108 */
81 char gid[8]; /* 116 */
82 char size[12]; /* 124 */
83 char mtime[12]; /* 136 */
84 char chksum[8]; /* 148 */
85 char typeflag; /* 156 */
86 char linkname[100]; /* 157 */
87 char magic[6]; /* 257 */
88 char version[2]; /* 263 */
89 char uname[32]; /* 265 */
90 char gname[32]; /* 297 */
91 char devmajor[8]; /* 329 */
92 char devminor[8]; /* 337 */
93 char prefix[155]; /* 345 */
94 /* 500 */
95 };
96
97 /* Descriptor for a single file hole */
98 struct sparse
99 { /* byte offset */
100 /* cppcheck-suppress unusedStructMember */
101 char offset[12]; /* 0 */
102 /* cppcheck-suppress unusedStructMember */
103 char numbytes[12]; /* 12 */
104 /* 24 */
105 };
106
107 /* Extension header for sparse files, used immediately after the GNU extra
108 header, and used only if all sparse information cannot fit into that
109 extra header. There might even be many such extension headers, one after
110 the other, until all sparse information has been recorded. */
111 struct sparse_header
112 { /* byte offset */
113 struct sparse sp[SPARSES_IN_SPARSE_HEADER];
114 /* 0 */
115 char isextended; /* 504 */
116 /* 505 */
117 };
118
119 /* The old GNU format header conflicts with POSIX format in such a way that
120 POSIX archives may fool old GNU tar's, and POSIX tar's might well be
121 fooled by old GNU tar archives. An old GNU format header uses the space
122 used by the prefix field in a POSIX header, and cumulates information
123 normally found in a GNU extra header. With an old GNU tar header, we
124 never see any POSIX header nor GNU extra header. Supplementary sparse
125 headers are allowed, however. */
126 struct oldgnu_header
127 { /* byte offset */
128 char unused_pad1[345]; /* 0 */
129 char atime[12]; /* 345 Incr. archive: atime of the file */
130 char ctime[12]; /* 357 Incr. archive: ctime of the file */
131 char offset[12]; /* 369 Multivolume archive: the offset of start of this volume */
132 char longnames[4]; /* 381 Not used */
133 char unused_pad2; /* 385 */
134 struct sparse sp[SPARSES_IN_OLDGNU_HEADER];
135 /* 386 */
136 char isextended; /* 482 Sparse file: Extension sparse header follows */
137 char realsize[12]; /* 483 Sparse file: Real size */
138 /* 495 */
139 };
140
141 /* J@"org Schilling star header */
142 struct star_header
143 { /* byte offset */
144 char name[100]; /* 0 */
145 char mode[8]; /* 100 */
146 char uid[8]; /* 108 */
147 char gid[8]; /* 116 */
148 char size[12]; /* 124 */
149 char mtime[12]; /* 136 */
150 char chksum[8]; /* 148 */
151 char typeflag; /* 156 */
152 char linkname[100]; /* 157 */
153 char magic[6]; /* 257 */
154 char version[2]; /* 263 */
155 char uname[32]; /* 265 */
156 char gname[32]; /* 297 */
157 char devmajor[8]; /* 329 */
158 char devminor[8]; /* 337 */
159 char prefix[131]; /* 345 */
160 char atime[12]; /* 476 */
161 char ctime[12]; /* 488 */
162 /* 500 */
163 };
164
165 struct star_in_header
166 {
167 char fill[345]; /* 0 Everything that is before t_prefix */
168 char prefix[1]; /* 345 t_name prefix */
169 char fill2; /* 346 */
170 char fill3[8]; /* 347 */
171 char isextended; /* 355 */
172 struct sparse sp[SPARSES_IN_STAR_HEADER]; /* 356 */
173 char realsize[12]; /* 452 Actual size of the file */
174 char offset[12]; /* 464 Offset of multivolume contents */
175 char atime[12]; /* 476 */
176 char ctime[12]; /* 488 */
177 char mfill[8]; /* 500 */
178 char xmagic[4]; /* 508 "tar" */
179 };
180
181 struct star_ext_header
182 {
183 struct sparse sp[SPARSES_IN_STAR_EXT_HEADER];
184 char isextended;
185 };
186
187 /* *INDENT-ON* */
188
189 /* tar Header Block, overall structure */
190 union block
191 {
192 char buffer[BLOCKSIZE];
193 struct posix_header header;
194 struct star_header star_header;
195 struct oldgnu_header oldgnu_header;
196 struct sparse_header sparse_header;
197 struct star_in_header star_in_header;
198 struct star_ext_header star_ext_header;
199 };
200
201 /* Information about a sparse file */
202 struct sp_array
203 {
204 off_t offset; /* chunk offset in file */
205 off_t numbytes; /* length of chunk */
206 off_t arch_offset; /* chunk offset in archive */
207 };
208
209 enum dump_status
210 {
211 dump_status_ok,
212 dump_status_short,
213 dump_status_fail,
214 dump_status_not_implemented
215 };
216
217 enum archive_format
218 {
219 TAR_UNKNOWN = 0, /**< format to be decided later */
220 TAR_V7, /**< old V7 tar format */
221 TAR_OLDGNU, /**< GNU format as per before tar 1.12 */
222 TAR_USTAR, /**< POSIX.1-1988 (ustar) format */
223 TAR_POSIX, /**< POSIX.1-2001 format */
224 TAR_STAR, /**< star format defined in 1994 */
225 TAR_GNU /**< almost same as OLDGNU_FORMAT */
226 };
227
228 typedef struct
229 {
230 struct vfs_s_super base; /* base class */
231
232 int fd;
233 struct stat st;
234 enum archive_format type; /**< type of the archive */
235 union block *record_start; /**< start of record of archive */
236 } tar_super_t;
237
238 struct xheader
239 {
240 size_t size;
241 char *buffer;
242 };
243
244 struct tar_stat_info
245 {
246 char *orig_file_name; /**< name of file read from the archive header */
247 char *file_name; /**< name of file for the current archive entry after being normalized */
248 char *link_name; /**< name of link for the current archive entry */
249 #if 0
250 char *uname; /**< user name of owner */
251 char *gname; /**< group name of owner */
252 #endif
253 struct stat stat; /**< regular filesystem stat */
254
255 /* stat() doesn't always have access, data modification, and status
256 change times in a convenient form, so store them separately. */
257 struct timespec atime;
258 struct timespec mtime;
259 struct timespec ctime;
260
261 off_t archive_file_size; /**< size of file as stored in the archive.
262 Equals stat.st_size for non-sparse files */
263 gboolean is_sparse; /**< is the file sparse */
264
265 /* For sparse files */
266 intmax_t sparse_major;
267 intmax_t sparse_minor;
268 GArray *sparse_map; /**< array of struct sp_array */
269
270 off_t real_size; /**< real size of sparse file */
271 gboolean real_size_set; /**< TRUE when GNU.sparse.realsize is set in archived file */
272
273 gboolean sparse_name_done; /**< TRUE if 'GNU.sparse.name' header was processed pax header parsing.
274 Following 'path' header (lower priority) will be ignored. */
275
276 /* Extended headers */
277 struct xheader xhdr;
278
279 /* For dumpdirs */
280 gboolean is_dumpdir; /**< is the member a dumpdir? */
281 gboolean skipped; /**< the member contents is already read (for GNUTYPE_DUMPDIR) */
282 char *dumpdir; /**< contents of the dump directory */
283 };
284
285 /*** global variables defined in .c file *********************************************************/
286
287 extern const idx_t blocking_factor;
288 extern const idx_t record_size;
289
290 extern union block *record_end; /* last+1 block of archive record */
291 extern union block *current_block; /* current block of archive */
292 extern off_t record_start_block; /* block ordinal at record_start */
293
294 extern union block *current_header;
295
296 /* Have we hit EOF yet? */
297 extern gboolean hit_eof;
298
299 extern struct tar_stat_info current_stat_info;
300
301 /*** declarations of public functions ************************************************************/
302
303 /* tar-internal.c */
304 gboolean is_octal_digit (char c);
305 void tar_assign_string (char **string, char *value);
306 void tar_assign_string_dup (char **string, const char *value);
307 void tar_assign_string_dup_n (char **string, const char *value, size_t n);
308 intmax_t stoint (const char *arg, char **arglim, gboolean *overflow, intmax_t minval,
309 uintmax_t maxval);
310 intmax_t tar_from_header (const char *where0, size_t digs, char const *type, intmax_t minval,
311 uintmax_t maxval, gboolean octal_only);
312 off_t off_from_header (const char *p, size_t s);
313 union block *tar_find_next_block (tar_super_t * archive);
314 gboolean tar_set_next_block_after (union block *block);
315 off_t tar_current_block_ordinal (const tar_super_t * archive);
316 gboolean tar_skip_file (tar_super_t * archive, off_t size);
317
318 /* tar-sparse.c */
319 gboolean tar_sparse_member_p (tar_super_t * archive, struct tar_stat_info *st);
320 gboolean tar_sparse_fixup_header (tar_super_t * archive, struct tar_stat_info *st);
321 enum dump_status tar_sparse_skip_file (tar_super_t * archive, struct tar_stat_info *st);
322
323 /* tar-xheader.c */
324 gboolean tar_xheader_decode (struct tar_stat_info *st);
325 gboolean tar_xheader_read (tar_super_t * archive, struct xheader *xhdr, union block *header,
326 off_t size);
327 gboolean tar_xheader_decode_global (struct xheader *xhdr);
328 void tar_xheader_destroy (struct xheader *xhdr);
329
330 /*** inline functions ****************************************************************************/
331
332 /**
333 * Represent @n using a signed integer I such that (uintmax_t) I == @n.
334 With a good optimizing compiler, this is equivalent to (intmax_t) i
335 and requires zero machine instructions. */
336 #if !(UINTMAX_MAX / 2 <= INTMAX_MAX)
337 #error "tar_represent_uintmax() returns intmax_t to represent uintmax_t"
338 #endif
339 static inline intmax_t
340 tar_represent_uintmax (uintmax_t n)
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*/
341 {
342 intmax_t nd;
343
344 if (n <= INTMAX_MAX)
345 return n;
346
347 /* Avoid signed integer overflow on picky platforms. */
348 nd = n - INTMAX_MIN;
349 return nd + INTMAX_MIN;
350 }
351
352 #endif /* MC__VFS_TAR_INTERNAL_H */
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