busybox/archival/libunarchive/get_header_cpio.c
Denis Vlasenko 1af00eda92 cpio: fix a bug where we do not extract zero-sized hardlinks
(spotted at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=466771).
Add testsuite entry for that, and another one for another bug:
we do not list hardlinks in cpio -t (not fixed).

function                                             old     new   delta
get_header_cpio                                      884     909     +25
static.saved_hardlinks_created                         -       4      +4
static.pending_hardlinks                               4       -      -4
static.inode                                           4       -      -4
cpio_main                                           1122    1060     -62
2008-04-05 02:44:30 +00:00

169 lines
4.9 KiB
C

/* vi: set sw=4 ts=4: */
/* Copyright 2002 Laurence Anderson
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
typedef struct hardlinks_s {
struct hardlinks_s *next;
int inode; /* TODO: must match maj/min too! */
int mode ;
int mtime; /* These three are useful only in corner case */
int uid ; /* of hardlinks with zero size body */
int gid ;
char name[1];
} hardlinks_t;
char get_header_cpio(archive_handle_t *archive_handle)
{
static hardlinks_t *saved_hardlinks = NULL;
static hardlinks_t *saved_hardlinks_created = NULL;
file_header_t *file_header = archive_handle->file_header;
char cpio_header[110];
char dummy[16];
int namesize;
int major, minor, nlink, mode, inode;
unsigned size, uid, gid, mtime;
/* There can be padding before archive header */
data_align(archive_handle, 4);
if (archive_xread_all_eof(archive_handle, (unsigned char*)cpio_header, 110) == 0) {
goto create_hardlinks;
}
archive_handle->offset += 110;
if (strncmp(&cpio_header[0], "07070", 5) != 0
|| (cpio_header[5] != '1' && cpio_header[5] != '2')
) {
bb_error_msg_and_die("unsupported cpio format, use newc or crc");
}
sscanf(cpio_header + 6,
"%8x" "%8x" "%8x" "%8x"
"%8x" "%8x" "%8x" /*maj,min:*/ "%16c"
/*rmaj,rmin:*/"%8x" "%8x" "%8x" /*chksum:*/ "%8c",
&inode, &mode, &uid, &gid,
&nlink, &mtime, &size, dummy,
&major, &minor, &namesize, dummy);
file_header->mode = mode;
file_header->uid = uid;
file_header->gid = gid;
file_header->mtime = mtime;
file_header->size = size;
file_header->name = xzalloc(namesize + 1);
/* Read in filename */
xread(archive_handle->src_fd, file_header->name, namesize);
archive_handle->offset += namesize;
/* Update offset amount and skip padding before file contents */
data_align(archive_handle, 4);
if (strcmp(file_header->name, "TRAILER!!!") == 0) {
/* Always round up. ">> 9" divides by 512 */
printf("%"OFF_FMT"u blocks\n", (archive_handle->offset + 511) >> 9);
goto create_hardlinks;
}
if (S_ISLNK(file_header->mode)) {
file_header->link_target = xzalloc(file_header->size + 1);
xread(archive_handle->src_fd, file_header->link_target, file_header->size);
archive_handle->offset += file_header->size;
file_header->size = 0; /* Stop possible seeks in future */
} else {
file_header->link_target = NULL;
}
// TODO: data_extract_all can't deal with hardlinks to non-files...
// (should be !S_ISDIR instead of S_ISREG here)
if (nlink > 1 && S_ISREG(file_header->mode)) {
hardlinks_t *new = xmalloc(sizeof(*new) + namesize);
new->inode = inode;
new->mode = mode ;
new->mtime = mtime;
new->uid = uid ;
new->gid = gid ;
strcpy(new->name, file_header->name);
/* Put file on a linked list for later */
if (size == 0) {
new->next = saved_hardlinks;
saved_hardlinks = new;
return EXIT_SUCCESS; /* Skip this one */
/* TODO: this breaks cpio -t (it does not show hardlinks) */
}
new->next = saved_hardlinks_created;
saved_hardlinks_created = new;
}
file_header->device = makedev(major, minor);
if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
archive_handle->action_data(archive_handle);
archive_handle->action_header(file_header);
} else {
data_skip(archive_handle);
}
archive_handle->offset += file_header->size;
free(file_header->link_target);
free(file_header->name);
file_header->link_target = NULL;
file_header->name = NULL;
return EXIT_SUCCESS;
create_hardlinks:
free(file_header->link_target);
free(file_header->name);
while (saved_hardlinks) {
hardlinks_t *cur;
hardlinks_t *make_me = saved_hardlinks;
saved_hardlinks = make_me->next;
memset(file_header, 0, sizeof(*file_header));
file_header->name = make_me->name;
file_header->mode = make_me->mode;
/*file_header->size = 0;*/
/* Try to find a file we are hardlinked to */
cur = saved_hardlinks_created;
while (cur) {
/* TODO: must match maj/min too! */
if (cur->inode == make_me->inode) {
file_header->link_target = cur->name;
/* link_target != NULL, size = 0: "I am a hardlink" */
if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
archive_handle->action_data(archive_handle);
free(make_me);
goto next_link;
}
}
/* Oops... no file with such inode was created... do it now
* (happens when hardlinked files are empty (zero length)) */
file_header->mtime = make_me->mtime;
file_header->uid = make_me->uid ;
file_header->gid = make_me->gid ;
if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
archive_handle->action_data(archive_handle);
/* Move to the list of created hardlinked files */
make_me->next = saved_hardlinks_created;
saved_hardlinks_created = make_me;
next_link: ;
}
while (saved_hardlinks_created) {
hardlinks_t *p = saved_hardlinks_created;
saved_hardlinks_created = p->next;
free(p);
}
return EXIT_FAILURE; /* "No more files to process" */
}