tar: fix interaction of delayed symlink and hardlink creation

function                                             old     new   delta
create_or_remember_link                                -     106    +106
create_links_from_list                                 -      93     +93
find_applet_by_name                                  124     128      +4
unzip_main                                          2724    2726      +2
data_extract_all                                     891     873     -18
create_symlinks_from_list                             64       -     -64
create_or_remember_symlink                            94       -     -94
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 2/1 up/down: 205/-176)           Total: 29 bytes

Signed-off-by: Harald van Dijk <harald@gigawatt.nl>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Harald van Dijk 2018-05-22 17:34:31 +02:00 committed by Denys Vlasenko
parent a40a661d97
commit 8c24af9dcf
8 changed files with 47 additions and 30 deletions

View File

@ -508,7 +508,7 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
continue;
create_symlinks_from_list(archive_handle->symlink_placeholders);
create_links_from_list(archive_handle->link_placeholders);
if (archive_handle->cpio__blocks != (off_t)-1
&& !(opt & OPT_QUIET)

View File

@ -122,13 +122,10 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
/* Handle hard links separately */
if (hard_link) {
res = link(hard_link, dst_name);
if (res != 0) {
/* shared message */
bb_perror_msg("can't create %slink '%s' to '%s'",
"hard", dst_name, hard_link
);
}
create_or_remember_link(&archive_handle->link_placeholders,
hard_link,
dst_name,
1);
/* Hardlinks have no separate mode/ownership, skip chown/chmod */
goto ret;
}
@ -195,9 +192,10 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
*
* Untarring bug.tar would otherwise place evil.py in '/tmp'.
*/
create_or_remember_symlink(&archive_handle->symlink_placeholders,
create_or_remember_link(&archive_handle->link_placeholders,
file_header->link_target,
dst_name);
dst_name,
0);
break;
case S_IFSOCK:
case S_IFBLK:

View File

@ -126,7 +126,7 @@ char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
struct archive_handle_t *sa = archive_handle->dpkg__sub_archive;
while (archive_handle->dpkg__action_data_subarchive(sa) == EXIT_SUCCESS)
continue;
create_symlinks_from_list(sa->symlink_placeholders);
create_links_from_list(sa->link_placeholders);
} else
#endif
archive_handle->action_data(archive_handle);

View File

@ -5,13 +5,14 @@
#include "libbb.h"
#include "bb_archive.h"
void FAST_FUNC create_or_remember_symlink(llist_t **symlink_placeholders,
void FAST_FUNC create_or_remember_link(llist_t **link_placeholders,
const char *target,
const char *linkname)
const char *linkname,
int hard_link)
{
if (target[0] == '/' || strstr(target, "..")) {
llist_add_to(symlink_placeholders,
xasprintf("%s%c%s", linkname, '\0', target)
if (hard_link || target[0] == '/' || strstr(target, "..")) {
llist_add_to_end(link_placeholders,
xasprintf("%c%s%c%s", hard_link, linkname, '\0', target)
);
return;
}
@ -23,17 +24,17 @@ void FAST_FUNC create_or_remember_symlink(llist_t **symlink_placeholders,
}
}
void FAST_FUNC create_symlinks_from_list(llist_t *list)
void FAST_FUNC create_links_from_list(llist_t *list)
{
while (list) {
char *target;
target = list->data + strlen(list->data) + 1;
if (symlink(target, list->data)) {
target = list->data + 1 + strlen(list->data + 1) + 1;
if ((*list->data ? link : symlink) (target, list->data + 1)) {
/* shared message */
bb_error_msg_and_die("can't create %slink '%s' to '%s'",
"sym",
list->data, target
*list->data ? "hard" : "sym",
list->data + 1, target
);
}
list = list->link;

View File

@ -1244,7 +1244,7 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
while (get_header_tar(tar_handle) == EXIT_SUCCESS)
bb_got_signal = EXIT_SUCCESS; /* saw at least one header, good */
create_symlinks_from_list(tar_handle->symlink_placeholders);
create_links_from_list(tar_handle->link_placeholders);
/* Check that every file that should have been extracted was */
while (tar_handle->accept) {

View File

@ -372,9 +372,10 @@ static void unzip_extract_symlink(llist_t **symlink_placeholders,
target[xstate.mem_output_size] = '\0';
#endif
}
create_or_remember_symlink(symlink_placeholders,
create_or_remember_link(symlink_placeholders,
target,
dst_fn);
dst_fn,
0);
free(target);
}
#endif
@ -990,7 +991,7 @@ int unzip_main(int argc, char **argv)
}
#if ENABLE_FEATURE_UNZIP_CDF
create_symlinks_from_list(symlink_placeholders);
create_links_from_list(symlink_placeholders);
#endif
if ((opts & OPT_l) && quiet <= 1) {

View File

@ -64,8 +64,8 @@ typedef struct archive_handle_t {
/* Currently processed file's header */
file_header_t *file_header;
/* List of symlink placeholders */
llist_t *symlink_placeholders;
/* List of link placeholders */
llist_t *link_placeholders;
/* Process the header component, e.g. tar -t */
void FAST_FUNC (*action_header)(const file_header_t *);
@ -203,10 +203,11 @@ void seek_by_jump(int fd, off_t amount) FAST_FUNC;
void seek_by_read(int fd, off_t amount) FAST_FUNC;
const char *strip_unsafe_prefix(const char *str) FAST_FUNC;
void create_or_remember_symlink(llist_t **symlink_placeholders,
void create_or_remember_link(llist_t **link_placeholders,
const char *target,
const char *linkname) FAST_FUNC;
void create_symlinks_from_list(llist_t *list) FAST_FUNC;
const char *linkname,
int hard_link) FAST_FUNC;
void create_links_from_list(llist_t *list) FAST_FUNC;
void data_align(archive_handle_t *archive_handle, unsigned boundary) FAST_FUNC;
const llist_t *find_list_entry(const llist_t *list, const char *filename) FAST_FUNC;

View File

@ -365,4 +365,20 @@ n8fYaKlioCTzL2oXYczyUUIP4u5IpwoSEwWdtoA=
SKIP=
cd .. || exit 1; rm -rf tar.tempdir 2>/dev/null
mkdir tar.tempdir && cd tar.tempdir || exit 1
testing "Symlinks and hardlinks coexist" '\
mkdir dir
>dir/a
ln -s ../dir/a dir/b
ln dir/b dir/c
mkdir new
tar cf - dir/* | tar -C new -xvf - 2>&1
' "\
dir/a
dir/b
dir/c
" \
"" ""
cd .. || exit 1; rm -rf tar.tempdir 2>/dev/null
exit $FAILCOUNT