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tar: optional autodetection of gz/bz2 compressed tarballs.

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+130 bytes. Closes bug 992.
This commit is contained in:
Denis Vlasenko
2008-02-19 11:26:28 +00:00
parent a37e7134f7
commit 431a7c9c53
3 changed files with 94 additions and 33 deletions
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52
archival/libunarchive/get_header_tar.c
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@@ -46,6 +46,9 @@ void BUG_tar_header_size(void);
char get_header_tar(archive_handle_t *archive_handle)
{
static smallint end;
#if ENABLE_FEATURE_TAR_AUTODETECT
static smallint not_first;
#endif
file_header_t *file_header = archive_handle->file_header;
struct {
@@ -115,7 +118,7 @@ char get_header_tar(archive_handle_t *archive_handle)
* Read until the end to empty the pipe from gz or bz2
*/
while (full_read(archive_handle->src_fd, &tar, 512) == 512)
/* repeat */;
continue;
return EXIT_FAILURE;
}
end = 1;
@@ -123,16 +126,49 @@ char get_header_tar(archive_handle_t *archive_handle)
}
end = 0;
/* Check header has valid magic, "ustar" is for the proper tar
* 0's are for the old tar format
*/
if (strncmp(tar.magic, "ustar", 5) != 0) {
#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
if (memcmp(tar.magic, "\0\0\0\0", 5) != 0)
/* Check header has valid magic, "ustar" is for the proper tar,
* five NULs are for the old tar format */
if (strncmp(tar.magic, "ustar", 5) != 0
&& (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
|| memcmp(tar.magic, "\0\0\0\0", 5) != 0)
) {
#if ENABLE_FEATURE_TAR_AUTODETECT
char (*get_header_ptr)(archive_handle_t *);
/* tar gz/bz autodetect: check for gz/bz2 magic.
* If it is the very first block, and we see the magic,
* we can switch to get_header_tar_gz/bz2/lzma().
* Needs seekable fd. I wish recv(MSG_PEEK) would work
* on any fd... */
if (not_first)
goto err;
#if ENABLE_FEATURE_TAR_GZIP
if (tar.name[0] == 0x1f && tar.name[1] == 0x8b) { /* gzip */
get_header_ptr = get_header_tar_gz;
} else
#endif
bb_error_msg_and_die("invalid tar magic");
#if ENABLE_FEATURE_TAR_BZIP2
if (tar.name[0] == 'B' && tar.name[1] == 'Z'
&& tar.name[2] == 'h' && isdigit(tar.name[3])
) { /* bzip2 */
get_header_ptr = get_header_tar_bz2;
} else
#endif
goto err;
if (lseek(archive_handle->src_fd, -512, SEEK_CUR) != 0)
goto err;
while (get_header_ptr(archive_handle) == EXIT_SUCCESS)
continue;
return EXIT_FAILURE;
err:
#endif /* FEATURE_TAR_AUTODETECT */
bb_error_msg_and_die("invalid tar magic");
}
#if ENABLE_FEATURE_TAR_AUTODETECT
not_first = 1;
#endif
/* Do checksum on headers.
* POSIX says that checksum is done on unsigned bytes, but
* Sun and HP-UX gets it wrong... more details in