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Diffstat (limited to 'src/vfs/tar/tar-sparse.c')
| -rw-r--r-- | src/vfs/tar/tar-sparse.c | 777 |
1 files changed, 777 insertions, 0 deletions
diff --git a/src/vfs/tar/tar-sparse.c b/src/vfs/tar/tar-sparse.c new file mode 100644 index 0000000..0bc169b --- /dev/null +++ b/src/vfs/tar/tar-sparse.c @@ -0,0 +1,777 @@ +/* + Virtual File System: GNU Tar file system. + + Copyright (C) 2003-2023 + Free Software Foundation, Inc. + + Written by: + Andrew Borodin <aborodin@vmail.ru>, 2023 + + This file is part of the Midnight Commander. + + The Midnight Commander is free software: you can redistribute it + and/or modify it under the terms of the GNU General Public License as + published by the Free Software Foundation, either version 3 of the License, + or (at your option) any later version. + + The Midnight Commander is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/** + * \file + * \brief Source: Virtual File System: GNU Tar file system + */ + +/* + * Avoid following error: + * comparison of unsigned expression < 0 is always false [-Werror=type-limits] + * + * https://www.boost.org/doc/libs/1_55_0/libs/integer/test/cstdint_test.cpp + * We can't suppress this warning on the command line as not all GCC versions support -Wno-type-limits + */ +#if defined(__GNUC__) && (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 4)) +#pragma GCC diagnostic ignored "-Wtype-limits" +#endif + +#include <config.h> + +#include <ctype.h> /* isdigit() */ +#include <errno.h> +#include <inttypes.h> /* uintmax_t */ + +#include "lib/global.h" + +#include "tar-internal.h" + +/* Old GNU Format. + The sparse file information is stored in the oldgnu_header in the following manner: + + The header is marked with type 'S'. Its 'size' field contains the cumulative size + of all non-empty blocks of the file. The actual file size is stored in `realsize' + member of oldgnu_header. + + The map of the file is stored in a list of 'struct sparse'. Each struct contains + offset to the block of data and its size (both as octal numbers). The first file + header contains at most 4 such structs (SPARSES_IN_OLDGNU_HEADER). If the map + contains more structs, then the field 'isextended' of the main header is set to + 1 (binary) and the 'struct sparse_header' header follows, containing at most + 21 following structs (SPARSES_IN_SPARSE_HEADER). If more structs follow, 'isextended' + field of the extended header is set and next next extension header follows, etc... + */ + +/*** global variables ****************************************************************************/ + +/*** file scope macro definitions ****************************************************************/ + +/* The width in bits of the integer type or expression T. + Do not evaluate T. T must not be a bit-field expression. + Padding bits are not supported; this is checked at compile-time below. */ +#define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT) + +/* Bound on length of the string representing an unsigned integer + value representable in B bits. log10 (2.0) < 146/485. The + smallest value of B where this bound is not tight is 2621. */ +#define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485) + +/* Does the __typeof__ keyword work? This could be done by + 'configure', but for now it's easier to do it by hand. */ +#if (2 <= __GNUC__ \ + || (4 <= __clang_major__) \ + || (1210 <= __IBMC__ && defined __IBM__TYPEOF__) \ + || (0x5110 <= __SUNPRO_C && !__STDC__)) +#define _GL_HAVE___TYPEOF__ 1 +#else +#define _GL_HAVE___TYPEOF__ 0 +#endif + +/* Return 1 if the integer type or expression T might be signed. Return 0 + if it is definitely unsigned. T must not be a bit-field expression. + This macro does not evaluate its argument, and expands to an + integer constant expression. */ +#if _GL_HAVE___TYPEOF__ +#define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t)) +#else +#define _GL_SIGNED_TYPE_OR_EXPR(t) 1 +#endif + +/* Return a value with the common real type of E and V and the value of V. + Do not evaluate E. */ +#define _GL_INT_CONVERT(e, v) ((1 ? 0 : (e)) + (v)) + +/* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see + <https://lists.gnu.org/r/bug-gnulib/2011-05/msg00406.html>. */ +#define _GL_INT_NEGATE_CONVERT(e, v) ((1 ? 0 : (e)) - (v)) + +/* Return 1 if the real expression E, after promotion, has a + signed or floating type. Do not evaluate E. */ +#define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0) + +#define _GL_SIGNED_INT_MAXIMUM(e) \ + (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH (+ (e)) - 2)) - 1) * 2 + 1) + +/* The maximum and minimum values for the type of the expression E, + after integer promotion. E is not evaluated. */ +#define _GL_INT_MINIMUM(e) \ + (EXPR_SIGNED (e) \ + ? ~_GL_SIGNED_INT_MAXIMUM (e) \ + : _GL_INT_CONVERT (e, 0)) +#define _GL_INT_MAXIMUM(e) \ + (EXPR_SIGNED (e) \ + ? _GL_SIGNED_INT_MAXIMUM (e) \ + : _GL_INT_NEGATE_CONVERT (e, 1)) + +/* Return 1 if the expression A <op> B would overflow, + where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test, + assuming MIN and MAX are the minimum and maximum for the result type. + Arguments should be free of side effects. */ +#define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \ + op_result_overflow (a, b, \ + _GL_INT_MINIMUM (_GL_INT_CONVERT (a, b)), \ + _GL_INT_MAXIMUM (_GL_INT_CONVERT (a, b))) + +#define INT_ADD_RANGE_OVERFLOW(a, b, min, max) \ + ((b) < 0 \ + ? (a) < (min) - (b) \ + : (max) - (b) < (a)) + + +/* True if __builtin_add_overflow_p (A, B, C) works, and similarly for + __builtin_sub_overflow_p and __builtin_mul_overflow_p. */ +#if defined __clang__ || defined __ICC +/* Clang 11 lacks __builtin_mul_overflow_p, and even if it did it + would presumably run afoul of Clang bug 16404. ICC 2021.1's + __builtin_add_overflow_p etc. are not treated as integral constant + expressions even when all arguments are. */ +#define _GL_HAS_BUILTIN_OVERFLOW_P 0 +#elif defined __has_builtin +#define _GL_HAS_BUILTIN_OVERFLOW_P __has_builtin (__builtin_mul_overflow_p) +#else +#define _GL_HAS_BUILTIN_OVERFLOW_P (7 <= __GNUC__) +#endif + +/* The _GL*_OVERFLOW macros have the same restrictions as the + *_RANGE_OVERFLOW macros, except that they do not assume that operands + (e.g., A and B) have the same type as MIN and MAX. Instead, they assume + that the result (e.g., A + B) has that type. */ +#if _GL_HAS_BUILTIN_OVERFLOW_P +#define _GL_ADD_OVERFLOW(a, b, min, max) \ + __builtin_add_overflow_p (a, b, (__typeof__ ((a) + (b))) 0) +#else +#define _GL_ADD_OVERFLOW(a, b, min, max) \ + ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \ + : (a) < 0 ? (b) <= (a) + (b) \ + : (b) < 0 ? (a) <= (a) + (b) \ + : (a) + (b) < (b)) +#endif + +/* Bound on length of the string representing an integer type or expression T. + T must not be a bit-field expression. + + Subtract 1 for the sign bit if T is signed, and then add 1 more for + a minus sign if needed. + + Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 1 when its argument is + unsigned, this macro may overestimate the true bound by one byte when + applied to unsigned types of size 2, 4, 16, ... bytes. */ +#define INT_STRLEN_BOUND(t) \ + (INT_BITS_STRLEN_BOUND (TYPE_WIDTH (t) - _GL_SIGNED_TYPE_OR_EXPR (t)) \ + + _GL_SIGNED_TYPE_OR_EXPR (t)) + +/* Bound on buffer size needed to represent an integer type or expression T, + including the terminating null. T must not be a bit-field expression. */ +#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) + +#define UINTMAX_STRSIZE_BOUND INT_BUFSIZE_BOUND (uintmax_t) + +#define INT_ADD_OVERFLOW(a, b) \ + _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW) + +#define SPARSES_INIT_COUNT SPARSES_IN_SPARSE_HEADER + +#define COPY_BUF(arch,b,buf,src) \ +do \ +{ \ + char *endp = b->buffer + BLOCKSIZE; \ + char *dst = buf; \ + do \ + { \ + if (dst == buf + UINTMAX_STRSIZE_BOUND - 1) \ + /* numeric overflow in sparse archive member */ \ + return FALSE; \ + if (src == endp) \ + { \ + tar_set_next_block_after (b); \ + b = tar_find_next_block (arch); \ + if (b == NULL) \ + /* unexpected EOF in archive */ \ + return FALSE; \ + src = b->buffer; \ + endp = b->buffer + BLOCKSIZE; \ + } \ + *dst = *src++; \ + } \ + while (*dst++ != '\n'); \ + dst[-1] = '\0'; \ +} \ +while (FALSE) + +/*** file scope type declarations ****************************************************************/ + +struct tar_sparse_file; + +struct tar_sparse_optab +{ + gboolean (*init) (struct tar_sparse_file * file); + gboolean (*done) (struct tar_sparse_file * file); + gboolean (*sparse_member_p) (struct tar_sparse_file * file); + gboolean (*fixup_header) (struct tar_sparse_file * file); + gboolean (*decode_header) (tar_super_t * archive, struct tar_sparse_file * file); +}; + +struct tar_sparse_file +{ + int fd; /**< File descriptor */ + off_t dumped_size; /**< Number of bytes actually written to the archive */ + struct tar_stat_info *stat_info; /**< Information about the file */ + struct tar_sparse_optab const *optab; + void *closure; /**< Any additional data optab calls might reqiure */ +}; + +enum oldgnu_add_status +{ + add_ok, + add_finish, + add_fail +}; + +/*** forward declarations (file scope functions) *************************************************/ + +static gboolean oldgnu_sparse_member_p (struct tar_sparse_file *file); +static gboolean oldgnu_fixup_header (struct tar_sparse_file *file); +static gboolean oldgnu_get_sparse_info (tar_super_t * archive, struct tar_sparse_file *file); + +static gboolean star_sparse_member_p (struct tar_sparse_file *file); +static gboolean star_fixup_header (struct tar_sparse_file *file); +static gboolean star_get_sparse_info (tar_super_t * archive, struct tar_sparse_file *file); + +static gboolean pax_sparse_member_p (struct tar_sparse_file *file); +static gboolean pax_decode_header (tar_super_t * archive, struct tar_sparse_file *file); + +/*** file scope variables ************************************************************************/ + +/* *INDENT-OFF* */ +static struct tar_sparse_optab const oldgnu_optab = +{ + .init = NULL, /* No init function */ + .done = NULL, /* No done function */ + .sparse_member_p = oldgnu_sparse_member_p, + .fixup_header = oldgnu_fixup_header, + .decode_header = oldgnu_get_sparse_info +}; +/* *INDENT-ON* */ + +/* *INDENT-OFF* */ +static struct tar_sparse_optab const star_optab = +{ + .init = NULL, /* No init function */ + .done = NULL, /* No done function */ + .sparse_member_p = star_sparse_member_p, + .fixup_header = star_fixup_header, + .decode_header = star_get_sparse_info +}; +/* *INDENT-ON* */ + +/* GNU PAX sparse file format. There are several versions: + * 0.0 + + The initial version of sparse format used by tar 1.14-1.15.1. + The sparse file map is stored in x header: + + GNU.sparse.size Real size of the stored file + GNU.sparse.numblocks Number of blocks in the sparse map repeat numblocks time + GNU.sparse.offset Offset of the next data block + GNU.sparse.numbytes Size of the next data block end repeat + + This has been reported as conflicting with the POSIX specs. The reason is + that offsets and sizes of non-zero data blocks were stored in multiple instances + of GNU.sparse.offset/GNU.sparse.numbytes variables, whereas POSIX requires the + latest occurrence of the variable to override all previous occurrences. + + To avoid this incompatibility two following versions were introduced. + + * 0.1 + + Used by tar 1.15.2 -- 1.15.91 (alpha releases). + + The sparse file map is stored in x header: + + GNU.sparse.size Real size of the stored file + GNU.sparse.numblocks Number of blocks in the sparse map + GNU.sparse.map Map of non-null data chunks. A string consisting of comma-separated + values "offset,size[,offset,size]..." + + The resulting GNU.sparse.map string can be *very* long. While POSIX does not impose + any limit on the length of a x header variable, this can confuse some tars. + + * 1.0 + + Starting from this version, the exact sparse format version is specified explicitly + in the header using the following variables: + + GNU.sparse.major Major version + GNU.sparse.minor Minor version + + X header keeps the following variables: + + GNU.sparse.name Real file name of the sparse file + GNU.sparse.realsize Real size of the stored file (corresponds to the old GNU.sparse.size + variable) + + The name field of the ustar header is constructed using the pattern "%d/GNUSparseFile.%p/%f". + + The sparse map itself is stored in the file data block, preceding the actual file data. + It consists of a series of octal numbers of arbitrary length, delimited by newlines. + The map is padded with nulls to the nearest block boundary. + + The first number gives the number of entries in the map. Following are map entries, each one + consisting of two numbers giving the offset and size of the data block it describes. + + The format is designed in such a way that non-posix aware tars and tars not supporting + GNU.sparse.* keywords will extract each sparse file in its condensed form with the file map + attached and will place it into a separate directory. Then, using a simple program it would be + possible to expand the file to its original form even without GNU tar. + + Bu default, v.1.0 archives are created. To use other formats, --sparse-version option is provided. + Additionally, v.0.0 can be obtained by deleting GNU.sparse.map from 0.1 format: + --sparse-version 0.1 --pax-option delete=GNU.sparse.map + */ + +static struct tar_sparse_optab const pax_optab = { + .init = NULL, /* No init function */ + .done = NULL, /* No done function */ + .sparse_member_p = pax_sparse_member_p, + .fixup_header = NULL, /* No fixup_header function */ + .decode_header = pax_decode_header +}; + +/* --------------------------------------------------------------------------------------------- */ +/*** file scope functions ************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +decode_num (uintmax_t * num, const char *arg, uintmax_t maxval) +{ + uintmax_t u; + char *arg_lim; + + if (!isdigit (*arg)) + return FALSE; + + errno = 0; + u = (uintmax_t) g_ascii_strtoll (arg, &arg_lim, 10); + + if (!(u <= maxval && errno != ERANGE) || *arg_lim != '\0') + return FALSE; + + *num = u; + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +sparse_select_optab (const tar_super_t * archive, struct tar_sparse_file *file) +{ + switch (archive->type) + { + case TAR_V7: + case TAR_USTAR: + return FALSE; + + case TAR_OLDGNU: + case TAR_GNU: /* FIXME: This one should disappear? */ + file->optab = &oldgnu_optab; + break; + + case TAR_POSIX: + file->optab = &pax_optab; + break; + + case TAR_STAR: + file->optab = &star_optab; + break; + + default: + return FALSE; + } + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +sparse_init (tar_super_t * archive, struct tar_sparse_file *file) +{ + memset (file, 0, sizeof (*file)); + + if (!sparse_select_optab (archive, file)) + return FALSE; + + if (file->optab->init != NULL) + return file->optab->init (file); + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +sparse_done (struct tar_sparse_file *file) +{ + if (file->optab->done != NULL) + return file->optab->done (file); + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +sparse_member_p (struct tar_sparse_file *file) +{ + if (file->optab->sparse_member_p != NULL) + return file->optab->sparse_member_p (file); + + return FALSE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +sparse_fixup_header (struct tar_sparse_file *file) +{ + if (file->optab->fixup_header != NULL) + return file->optab->fixup_header (file); + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +sparse_decode_header (tar_super_t * archive, struct tar_sparse_file *file) +{ + if (file->optab->decode_header != NULL) + return file->optab->decode_header (archive, file); + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static inline void +sparse_add_map (struct tar_stat_info *st, struct sp_array *sp) +{ + if (st->sparse_map == NULL) + st->sparse_map = g_array_sized_new (FALSE, FALSE, sizeof (struct sp_array), 1); + g_array_append_val (st->sparse_map, *sp); +} + +/* --------------------------------------------------------------------------------------------- */ + +/** + * Add a sparse item to the sparse file + */ +static enum oldgnu_add_status +oldgnu_add_sparse (struct tar_sparse_file *file, struct sparse *s) +{ + struct sp_array sp; + + if (s->numbytes[0] == '\0') + return add_finish; + + sp.offset = OFF_FROM_HEADER (s->offset); + sp.numbytes = OFF_FROM_HEADER (s->numbytes); + + if (sp.offset < 0 || sp.numbytes < 0 + || INT_ADD_OVERFLOW (sp.offset, sp.numbytes) + || file->stat_info->stat.st_size < sp.offset + sp.numbytes + || file->stat_info->archive_file_size < 0) + return add_fail; + + sparse_add_map (file->stat_info, &sp); + + return add_ok; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +oldgnu_sparse_member_p (struct tar_sparse_file *file) +{ + (void) file; + + return current_header->header.typeflag == GNUTYPE_SPARSE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +oldgnu_fixup_header (struct tar_sparse_file *file) +{ + /* NOTE! st_size was initialized from the header which actually contains archived size. + The following fixes it */ + off_t realsize; + + realsize = OFF_FROM_HEADER (current_header->oldgnu_header.realsize); + file->stat_info->archive_file_size = file->stat_info->stat.st_size; + file->stat_info->stat.st_size = MAX (0, realsize); + + return (realsize >= 0); +} + +/* --------------------------------------------------------------------------------------------- */ + +/** + * Convert old GNU format sparse data to internal representation. + */ +static gboolean +oldgnu_get_sparse_info (tar_super_t * archive, struct tar_sparse_file *file) +{ + size_t i; + union block *h = current_header; + int ext_p; + enum oldgnu_add_status rc; + + if (file->stat_info->sparse_map != NULL) + g_array_set_size (file->stat_info->sparse_map, 0); + + for (i = 0; i < SPARSES_IN_OLDGNU_HEADER; i++) + { + rc = oldgnu_add_sparse (file, &h->oldgnu_header.sp[i]); + if (rc != add_ok) + break; + } + + for (ext_p = h->oldgnu_header.isextended ? 1 : 0; rc == add_ok && ext_p != 0; + ext_p = h->sparse_header.isextended ? 1 : 0) + { + h = tar_find_next_block (archive); + if (h == NULL) + return FALSE; + + tar_set_next_block_after (h); + + for (i = 0; i < SPARSES_IN_SPARSE_HEADER && rc == add_ok; i++) + rc = oldgnu_add_sparse (file, &h->sparse_header.sp[i]); + } + + return (rc != add_fail); +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +star_sparse_member_p (struct tar_sparse_file *file) +{ + (void) file; + + return current_header->header.typeflag == GNUTYPE_SPARSE; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +star_fixup_header (struct tar_sparse_file *file) +{ + /* NOTE! st_size was initialized from the header which actually contains archived size. + The following fixes it */ + off_t realsize; + + realsize = OFF_FROM_HEADER (current_header->star_in_header.realsize); + file->stat_info->archive_file_size = file->stat_info->stat.st_size; + file->stat_info->stat.st_size = MAX (0, realsize); + + return (realsize >= 0); +} + +/* --------------------------------------------------------------------------------------------- */ + +/** + * Convert STAR format sparse data to internal representation + */ +static gboolean +star_get_sparse_info (tar_super_t * archive, struct tar_sparse_file *file) +{ + size_t i; + union block *h = current_header; + int ext_p = 1; + enum oldgnu_add_status rc = add_ok; + + if (file->stat_info->sparse_map != NULL) + g_array_set_size (file->stat_info->sparse_map, 0); + + if (h->star_in_header.prefix[0] == '\0' && h->star_in_header.sp[0].offset[10] != '\0') + { + /* Old star format */ + for (i = 0; i < SPARSES_IN_STAR_HEADER; i++) + { + rc = oldgnu_add_sparse (file, &h->star_in_header.sp[i]); + if (rc != add_ok) + break; + } + + ext_p = h->star_in_header.isextended ? 1 : 0; + } + + for (; rc == add_ok && ext_p != 0; ext_p = h->star_ext_header.isextended ? 1 : 0) + { + h = tar_find_next_block (archive); + if (h == NULL) + return FALSE; + + tar_set_next_block_after (h); + + for (i = 0; i < SPARSES_IN_STAR_EXT_HEADER && rc == add_ok; i++) + rc = oldgnu_add_sparse (file, &h->star_ext_header.sp[i]); + + file->dumped_size += BLOCKSIZE; + } + + return (rc != add_fail); +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +pax_sparse_member_p (struct tar_sparse_file *file) +{ + return file->stat_info->sparse_map != NULL && file->stat_info->sparse_map->len > 0 + && file->stat_info->sparse_major > 0; +} + +/* --------------------------------------------------------------------------------------------- */ + +static gboolean +pax_decode_header (tar_super_t * archive, struct tar_sparse_file *file) +{ + if (file->stat_info->sparse_major > 0) + { + uintmax_t u; + char nbuf[UINTMAX_STRSIZE_BOUND]; + union block *blk; + char *p; + size_t sparse_map_len; + size_t i; + off_t start; + + start = tar_current_block_ordinal (archive); + tar_set_next_block_after (current_header); + blk = tar_find_next_block (archive); + if (blk == NULL) + /* unexpected EOF in archive */ + return FALSE; + p = blk->buffer; + COPY_BUF (archive, blk, nbuf, p); + + if (!decode_num (&u, nbuf, TYPE_MAXIMUM (size_t))) + { + /* malformed sparse archive member */ + return FALSE; + } + + if (file->stat_info->sparse_map == NULL) + file->stat_info->sparse_map = + g_array_sized_new (FALSE, FALSE, sizeof (struct sp_array), u); + else + g_array_set_size (file->stat_info->sparse_map, u); + + sparse_map_len = u; + + for (i = 0; i < sparse_map_len; i++) + { + struct sp_array sp; + + COPY_BUF (archive, blk, nbuf, p); + if (!decode_num (&u, nbuf, TYPE_MAXIMUM (off_t))) + { + /* malformed sparse archive member */ + return FALSE; + } + sp.offset = u; + COPY_BUF (archive, blk, nbuf, p); + if (!decode_num (&u, nbuf, TYPE_MAXIMUM (size_t)) || INT_ADD_OVERFLOW (sp.offset, u) + || (uintmax_t) file->stat_info->stat.st_size < sp.offset + u) + { + /* malformed sparse archive member */ + return FALSE; + } + sp.numbytes = u; + sparse_add_map (file->stat_info, &sp); + } + + tar_set_next_block_after (blk); + + file->dumped_size += BLOCKSIZE * (tar_current_block_ordinal (archive) - start); + } + + return TRUE; +} + +/* --------------------------------------------------------------------------------------------- */ +/*** public functions ****************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ + +gboolean +tar_sparse_member_p (tar_super_t * archive, struct tar_stat_info * st) +{ + struct tar_sparse_file file; + + if (!sparse_init (archive, &file)) + return FALSE; + + file.stat_info = st; + return sparse_member_p (&file); +} + +/* --------------------------------------------------------------------------------------------- */ + +gboolean +tar_sparse_fixup_header (tar_super_t * archive, struct tar_stat_info * st) +{ + struct tar_sparse_file file; + + if (!sparse_init (archive, &file)) + return FALSE; + + file.stat_info = st; + return sparse_fixup_header (&file); +} + +/* --------------------------------------------------------------------------------------------- */ + +enum dump_status +tar_sparse_skip_file (tar_super_t * archive, struct tar_stat_info *st) +{ + gboolean rc = TRUE; + struct tar_sparse_file file; + + if (!sparse_init (archive, &file)) + return dump_status_not_implemented; + + file.stat_info = st; + file.fd = -1; + + rc = sparse_decode_header (archive, &file); + (void) tar_skip_file (archive, file.stat_info->archive_file_size - file.dumped_size); + return (sparse_done (&file) && rc) ? dump_status_ok : dump_status_short; +} + +/* --------------------------------------------------------------------------------------------- */ |