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tar: add support for --strip-components=N

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function                                             old     new   delta
data_extract_all                                     882     995    +113
tar_longopts                                         290     309     +19
tar_main                                             938     942      +4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 136/0)             Total: 136 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2015-10-22 01:07:13 +02:00
parent c47917865d
commit 6c563e370d
5 changed files with 156 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

108
archival/libarchive/data_extract_all.c
View File

@@ -8,9 +8,17 @@
void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
{
file_header_t *file_header = archive_handle->file_header;
int dst_fd;
int res;
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
char *dst_name;
char *dst_link;
#else
# define dst_name (file_header->name)
# define dst_link (file_header->link_target)
#endif
#if ENABLE_FEATURE_TAR_SELINUX
char *sctx = archive_handle->tar__sctx[PAX_NEXT_FILE];
@@ -23,11 +31,47 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
}
#endif
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
dst_name = file_header->name;
dst_link = file_header->link_target;
if (archive_handle->tar__strip_components) {
unsigned n = archive_handle->tar__strip_components;
do {
dst_name = strchr(dst_name, '/');
if (!dst_name || dst_name[1] == '\0') {
data_skip(archive_handle);
return;
}
dst_name++;
/*
* Link target is shortened only for hardlinks:
* softlinks restored unchanged.
*/
if (S_ISREG(file_header->mode)
&& file_header->size == 0
&& dst_link
) {
// GNU tar 1.26 does not check that we reached end of link name:
// if "dir/hardlink" is hardlinked to "file",
// tar xvf a.tar --strip-components=1 says:
// tar: hardlink: Cannot hard link to '': No such file or directory
// and continues processing. We silently skip such entries.
dst_link = strchr(dst_link, '/');
if (!dst_link || dst_link[1] == '\0') {
data_skip(archive_handle);
return;
}
dst_link++;
}
} while (--n != 0);
}
#endif
if (archive_handle->ah_flags & ARCHIVE_CREATE_LEADING_DIRS) {
char *slash = strrchr(file_header->name, '/');
char *slash = strrchr(dst_name, '/');
if (slash) {
*slash = '\0';
bb_make_directory(file_header->name, -1, FILEUTILS_RECUR);
bb_make_directory(dst_name, -1, FILEUTILS_RECUR);
*slash = '/';
}
}
@@ -38,8 +82,8 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
/* Is it hardlink?
* We encode hard links as regular files of size 0 with a symlink */
if (S_ISREG(file_header->mode)
&& file_header->link_target
&& file_header->size == 0
&& dst_link
) {
/* Ugly special case:
* tar cf t.tar hardlink1 hardlink2 hardlink1
@@ -48,22 +92,22 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
* hardlink2 -> hardlink1
* hardlink1 -> hardlink1 <== !!!
*/
if (strcmp(file_header->link_target, file_header->name) == 0)
if (strcmp(dst_link, dst_name) == 0)
goto ret;
}
/* Proceed with deleting */
if (unlink(file_header->name) == -1
if (unlink(dst_name) == -1
&& errno != ENOENT
) {
bb_perror_msg_and_die("can't remove old file %s",
file_header->name);
dst_name);
}
}
}
else if (archive_handle->ah_flags & ARCHIVE_EXTRACT_NEWER) {
/* Remove the existing entry if its older than the extracted entry */
struct stat existing_sb;
if (lstat(file_header->name, &existing_sb) == -1) {
if (lstat(dst_name, &existing_sb) == -1) {
if (errno != ENOENT) {
bb_perror_msg_and_die("can't stat old file");
}
@@ -73,30 +117,30 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
&& !S_ISDIR(file_header->mode)
) {
bb_error_msg("%s not created: newer or "
"same age file exists", file_header->name);
"same age file exists", dst_name);
}
data_skip(archive_handle);
goto ret;
}
else if ((unlink(file_header->name) == -1) && (errno != EISDIR)) {
else if ((unlink(dst_name) == -1) && (errno != EISDIR)) {
bb_perror_msg_and_die("can't remove old file %s",
file_header->name);
dst_name);
}
}
/* Handle hard links separately
* We encode hard links as regular files of size 0 with a symlink */
if (S_ISREG(file_header->mode)
&& file_header->link_target
&& file_header->size == 0
&& dst_link
) {
/* hard link */
res = link(file_header->link_target, file_header->name);
if ((res == -1) && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
/* Hard link */
res = link(dst_link, dst_name);
if (res != 0 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
bb_perror_msg("can't create %slink "
"from %s to %s", "hard",
file_header->name,
file_header->link_target);
dst_name,
dst_link);
}
/* Hardlinks have no separate mode/ownership, skip chown/chmod */
goto ret;
@@ -106,17 +150,17 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
switch (file_header->mode & S_IFMT) {
case S_IFREG: {
/* Regular file */
char *dst_name;
char *dst_nameN;
int flags = O_WRONLY | O_CREAT | O_EXCL;
if (archive_handle->ah_flags & ARCHIVE_O_TRUNC)
flags = O_WRONLY | O_CREAT | O_TRUNC;
dst_name = file_header->name;
dst_nameN = dst_name;
#ifdef ARCHIVE_REPLACE_VIA_RENAME
if (archive_handle->ah_flags & ARCHIVE_REPLACE_VIA_RENAME)
/* rpm-style temp file name */
dst_name = xasprintf("%s;%x", dst_name, (int)getpid());
dst_nameN = xasprintf("%s;%x", dst_name, (int)getpid());
#endif
dst_fd = xopen3(dst_name,
dst_fd = xopen3(dst_nameN,
flags,
file_header->mode
);
@@ -124,32 +168,32 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
close(dst_fd);
#ifdef ARCHIVE_REPLACE_VIA_RENAME
if (archive_handle->ah_flags & ARCHIVE_REPLACE_VIA_RENAME) {
xrename(dst_name, file_header->name);
free(dst_name);
xrename(dst_nameN, dst_name);
free(dst_nameN);
}
#endif
break;
}
case S_IFDIR:
res = mkdir(file_header->name, file_header->mode);
res = mkdir(dst_name, file_header->mode);
if ((res == -1)
&& (errno != EISDIR) /* btw, Linux doesn't return this */
&& (errno != EEXIST)
&& !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
) {
bb_perror_msg("can't make dir %s", file_header->name);
bb_perror_msg("can't make dir %s", dst_name);
}
break;
case S_IFLNK:
/* Symlink */
//TODO: what if file_header->link_target == NULL (say, corrupted tarball?)
res = symlink(file_header->link_target, file_header->name);
if ((res == -1)
res = symlink(file_header->link_target, dst_name);
if (res != 0
&& !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
) {
bb_perror_msg("can't create %slink "
"from %s to %s", "sym",
file_header->name,
dst_name,
file_header->link_target);
}
break;
@@ -157,11 +201,11 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
case S_IFBLK:
case S_IFCHR:
case S_IFIFO:
res = mknod(file_header->name, file_header->mode, file_header->device);
res = mknod(dst_name, file_header->mode, file_header->device);
if ((res == -1)
&& !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
) {
bb_perror_msg("can't create node %s", file_header->name);
bb_perror_msg("can't create node %s", dst_name);
}
break;
default:
@@ -186,20 +230,20 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
}
#endif
/* GNU tar 1.15.1 uses chown, not lchown */
chown(file_header->name, uid, gid);
chown(dst_name, uid, gid);
}
/* uclibc has no lchmod, glibc is even stranger -
* it has lchmod which seems to do nothing!
* so we use chmod... */
if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_PERM)) {
chmod(file_header->name, file_header->mode);
chmod(dst_name, file_header->mode);
}
if (archive_handle->ah_flags & ARCHIVE_RESTORE_DATE) {
struct timeval t[2];
t[1].tv_sec = t[0].tv_sec = file_header->mtime;
t[1].tv_usec = t[0].tv_usec = 0;
utimes(file_header->name, t);
utimes(dst_name, t);
}
}