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diff --git a/src/vfs/tar/tar-internal.h b/src/vfs/tar/tar-internal.h
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+
+#ifndef MC__VFS_TAR_INTERNAL_H
+#define MC__VFS_TAR_INTERNAL_H
+
+#include <inttypes.h> /* (u)intmax_t */
+#include <limits.h> /* CHAR_BIT, INT_MAX, etc */
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "lib/vfs/xdirentry.h" /* vfs_s_super */
+
+/*** typedefs(not structures) and defined constants **********************************************/
+
+/* tar files are made in basic blocks of this size. */
+#define BLOCKSIZE 512
+
+#define DEFAULT_BLOCKING 20
+
+/* Sparse files are not supported in POSIX ustar format. For sparse files
+ with a POSIX header, a GNU extra header is provided which holds overall
+ sparse information and a few sparse descriptors. When an old GNU header
+ replaces both the POSIX header and the GNU extra header, it holds some
+ sparse descriptors too. Whether POSIX or not, if more sparse descriptors
+ are still needed, they are put into as many successive sparse headers as
+ necessary. The following constants tell how many sparse descriptors fit
+ in each kind of header able to hold them. */
+
+#define SPARSES_IN_EXTRA_HEADER 16
+#define SPARSES_IN_OLDGNU_HEADER 4
+#define SPARSES_IN_SPARSE_HEADER 21
+
+#define SPARSES_IN_STAR_HEADER 4
+#define SPARSES_IN_STAR_EXT_HEADER 21
+
+/* *BEWARE* *BEWARE* *BEWARE* that the following information is still
+ boiling, and may change. Even if the OLDGNU format description should be
+ accurate, the so-called GNU format is not yet fully decided. It is
+ surely meant to use only extensions allowed by POSIX, but the sketch
+ below repeats some ugliness from the OLDGNU format, which should rather
+ go away. Sparse files should be saved in such a way that they do *not*
+ require two passes at archive creation time. Huge files get some POSIX
+ fields to overflow, alternate solutions have to be sought for this. */
+
+/* This is a dir entry that contains the names of files that were in the
+ dir at the time the dump was made. */
+#define GNUTYPE_DUMPDIR 'D'
+
+/* Identifies the *next* file on the tape as having a long linkname. */
+#define GNUTYPE_LONGLINK 'K'
+
+/* Identifies the *next* file on the tape as having a long name. */
+#define GNUTYPE_LONGNAME 'L'
+
+/* Solaris extended header */
+#define SOLARIS_XHDTYPE 'X'
+
+#define GNUTYPE_SPARSE 'S'
+
+
+/* These macros work even on ones'-complement hosts (!).
+ The extra casts work around some compiler bugs. */
+#define TYPE_SIGNED(t) (!((t) 0 < (t) (-1)))
+#define TYPE_MINIMUM(t) (TYPE_SIGNED (t) ? ~(t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)
+#define TYPE_MAXIMUM(t) (~(t) 0 - TYPE_MINIMUM (t))
+
+#define OFF_FROM_HEADER(where) off_from_header (where, sizeof (where))
+
+#define isodigit(c) ( ((c) >= '0') && ((c) <= '7') )
+
+/*** enums ***************************************************************************************/
+
+/*** structures declarations (and typedefs of structures)*****************************************/
+
+/* *INDENT-OFF* */
+
+/* POSIX header */
+struct posix_header
+{ /* byte offset */
+ char name[100]; /* 0 */
+ char mode[8]; /* 100 */
+ char uid[8]; /* 108 */
+ char gid[8]; /* 116 */
+ char size[12]; /* 124 */
+ char mtime[12]; /* 136 */
+ char chksum[8]; /* 148 */
+ char typeflag; /* 156 */
+ char linkname[100]; /* 157 */
+ char magic[6]; /* 257 */
+ char version[2]; /* 263 */
+ char uname[32]; /* 265 */
+ char gname[32]; /* 297 */
+ char devmajor[8]; /* 329 */
+ char devminor[8]; /* 337 */
+ char prefix[155]; /* 345 */
+ /* 500 */
+};
+
+/* Descriptor for a single file hole */
+struct sparse
+{ /* byte offset */
+ /* cppcheck-suppress unusedStructMember */
+ char offset[12]; /* 0 */
+ /* cppcheck-suppress unusedStructMember */
+ char numbytes[12]; /* 12 */
+ /* 24 */
+};
+
+/* Extension header for sparse files, used immediately after the GNU extra
+ header, and used only if all sparse information cannot fit into that
+ extra header. There might even be many such extension headers, one after
+ the other, until all sparse information has been recorded. */
+struct sparse_header
+{ /* byte offset */
+ struct sparse sp[SPARSES_IN_SPARSE_HEADER];
+ /* 0 */
+ char isextended; /* 504 */
+ /* 505 */
+};
+
+/* The old GNU format header conflicts with POSIX format in such a way that
+ POSIX archives may fool old GNU tar's, and POSIX tar's might well be
+ fooled by old GNU tar archives. An old GNU format header uses the space
+ used by the prefix field in a POSIX header, and cumulates information
+ normally found in a GNU extra header. With an old GNU tar header, we
+ never see any POSIX header nor GNU extra header. Supplementary sparse
+ headers are allowed, however. */
+struct oldgnu_header
+{ /* byte offset */
+ char unused_pad1[345]; /* 0 */
+ char atime[12]; /* 345 Incr. archive: atime of the file */
+ char ctime[12]; /* 357 Incr. archive: ctime of the file */
+ char offset[12]; /* 369 Multivolume archive: the offset of start of this volume */
+ char longnames[4]; /* 381 Not used */
+ char unused_pad2; /* 385 */
+ struct sparse sp[SPARSES_IN_OLDGNU_HEADER];
+ /* 386 */
+ char isextended; /* 482 Sparse file: Extension sparse header follows */
+ char realsize[12]; /* 483 Sparse file: Real size */
+ /* 495 */
+};
+
+/* J@"org Schilling star header */
+struct star_header
+{ /* byte offset */
+ char name[100]; /* 0 */
+ char mode[8]; /* 100 */
+ char uid[8]; /* 108 */
+ char gid[8]; /* 116 */
+ char size[12]; /* 124 */
+ char mtime[12]; /* 136 */
+ char chksum[8]; /* 148 */
+ char typeflag; /* 156 */
+ char linkname[100]; /* 157 */
+ char magic[6]; /* 257 */
+ char version[2]; /* 263 */
+ char uname[32]; /* 265 */
+ char gname[32]; /* 297 */
+ char devmajor[8]; /* 329 */
+ char devminor[8]; /* 337 */
+ char prefix[131]; /* 345 */
+ char atime[12]; /* 476 */
+ char ctime[12]; /* 488 */
+ /* 500 */
+};
+
+struct star_in_header
+{
+ char fill[345]; /* 0 Everything that is before t_prefix */
+ char prefix[1]; /* 345 t_name prefix */
+ char fill2; /* 346 */
+ char fill3[8]; /* 347 */
+ char isextended; /* 355 */
+ struct sparse sp[SPARSES_IN_STAR_HEADER]; /* 356 */
+ char realsize[12]; /* 452 Actual size of the file */
+ char offset[12]; /* 464 Offset of multivolume contents */
+ char atime[12]; /* 476 */
+ char ctime[12]; /* 488 */
+ char mfill[8]; /* 500 */
+ char xmagic[4]; /* 508 "tar" */
+};
+
+struct star_ext_header
+{
+ struct sparse sp[SPARSES_IN_STAR_EXT_HEADER];
+ char isextended;
+};
+
+/* *INDENT-ON* */
+
+/* tar Header Block, overall structure */
+union block
+{
+ char buffer[BLOCKSIZE];
+ struct posix_header header;
+ struct star_header star_header;
+ struct oldgnu_header oldgnu_header;
+ struct sparse_header sparse_header;
+ struct star_in_header star_in_header;
+ struct star_ext_header star_ext_header;
+};
+
+/* Information about a sparse file */
+struct sp_array
+{
+ off_t offset; /* chunk offset in file */
+ off_t numbytes; /* length of chunk */
+ off_t arch_offset; /* chunk offset in archive */
+};
+
+enum dump_status
+{
+ dump_status_ok,
+ dump_status_short,
+ dump_status_fail,
+ dump_status_not_implemented
+};
+
+enum archive_format
+{
+ TAR_UNKNOWN = 0, /**< format to be decided later */
+ TAR_V7, /**< old V7 tar format */
+ TAR_OLDGNU, /**< GNU format as per before tar 1.12 */
+ TAR_USTAR, /**< POSIX.1-1988 (ustar) format */
+ TAR_POSIX, /**< POSIX.1-2001 format */
+ TAR_STAR, /**< star format defined in 1994 */
+ TAR_GNU /**< almost same as OLDGNU_FORMAT */
+};
+
+typedef struct
+{
+ struct vfs_s_super base; /* base class */
+
+ int fd;
+ struct stat st;
+ enum archive_format type; /**< type of the archive */
+ union block *record_start; /**< start of record of archive */
+} tar_super_t;
+
+struct xheader
+{
+ size_t size;
+ char *buffer;
+};
+
+struct tar_stat_info
+{
+ char *orig_file_name; /**< name of file read from the archive header */
+ char *file_name; /**< name of file for the current archive entry after being normalized */
+ char *link_name; /**< name of link for the current archive entry */
+#if 0
+ char *uname; /**< user name of owner */
+ char *gname; /**< group name of owner */
+#endif
+ struct stat stat; /**< regular filesystem stat */
+
+ /* stat() doesn't always have access, data modification, and status
+ change times in a convenient form, so store them separately. */
+ struct timespec atime;
+ struct timespec mtime;
+ struct timespec ctime;
+
+ off_t archive_file_size; /**< size of file as stored in the archive.
+ Equals stat.st_size for non-sparse files */
+ gboolean is_sparse; /**< is the file sparse */
+
+ /* For sparse files */
+ unsigned int sparse_major;
+ unsigned int sparse_minor;
+ GArray *sparse_map; /**< array of struct sp_array */
+
+ off_t real_size; /**< real size of sparse file */
+ gboolean real_size_set; /**< TRUE when GNU.sparse.realsize is set in archived file */
+
+ gboolean sparse_name_done; /**< TRUE if 'GNU.sparse.name' header was processed pax header parsing.
+ Following 'path' header (lower priority) will be ignored. */
+
+ /* Extended headers */
+ struct xheader xhdr;
+
+ /* For dumpdirs */
+ gboolean is_dumpdir; /**< is the member a dumpdir? */
+ gboolean skipped; /**< the member contents is already read (for GNUTYPE_DUMPDIR) */
+ char *dumpdir; /**< contents of the dump directory */
+};
+
+/*** global variables defined in .c file *********************************************************/
+
+extern const int blocking_factor;
+extern const size_t record_size;
+
+extern union block *record_end; /* last+1 block of archive record */
+extern union block *current_block; /* current block of archive */
+extern off_t record_start_block; /* block ordinal at record_start */
+
+extern union block *current_header;
+
+/* Have we hit EOF yet? */
+extern gboolean hit_eof;
+
+extern struct tar_stat_info current_stat_info;
+
+/*** declarations of public functions ************************************************************/
+
+/* tar-internal.c */
+void tar_base64_init (void);
+void tar_assign_string (char **string, char *value);
+void tar_assign_string_dup (char **string, const char *value);
+void tar_assign_string_dup_n (char **string, const char *value, size_t n);
+intmax_t tar_from_header (const char *where0, size_t digs, char const *type, intmax_t minval,
+ uintmax_t maxval, gboolean octal_only);
+off_t off_from_header (const char *p, size_t s);
+union block *tar_find_next_block (tar_super_t * archive);
+gboolean tar_set_next_block_after (union block *block);
+off_t tar_current_block_ordinal (const tar_super_t * archive);
+gboolean tar_skip_file (tar_super_t * archive, off_t size);
+
+/* tar-sparse.c */
+gboolean tar_sparse_member_p (tar_super_t * archive, struct tar_stat_info *st);
+gboolean tar_sparse_fixup_header (tar_super_t * archive, struct tar_stat_info *st);
+enum dump_status tar_sparse_skip_file (tar_super_t * archive, struct tar_stat_info *st);
+
+/* tar-xheader.c */
+gboolean tar_xheader_decode (struct tar_stat_info *st);
+gboolean tar_xheader_read (tar_super_t * archive, struct xheader *xhdr, union block *header,
+ off_t size);
+gboolean tar_xheader_decode_global (struct xheader *xhdr);
+void tar_xheader_destroy (struct xheader *xhdr);
+
+/*** inline functions ****************************************************************************/
+
+/**
+ * Represent @n using a signed integer I such that (uintmax_t) I == @n.
+ With a good optimizing compiler, this is equivalent to (intmax_t) i
+ and requires zero machine instructions. */
+#if !(UINTMAX_MAX / 2 <= INTMAX_MAX)
+#error "tar_represent_uintmax() returns intmax_t to represent uintmax_t"
+#endif
+static inline intmax_t
+tar_represent_uintmax (uintmax_t n)
+{
+ intmax_t nd;
+
+ if (n <= INTMAX_MAX)
+ return n;
+
+ /* Avoid signed integer overflow on picky platforms. */
+ nd = n - INTMAX_MIN;
+ return nd + INTMAX_MIN;
+}
+
+#endif /* MC__VFS_TAR_INTERNAL_H */
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