hush/archival/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

273 lines
6.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini cpio implementation for busybox
*
* Copyright (C) 2001 by Glenn McGrath
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
* Limitations:
* Doesn't check CRC's
* Only supports new ASCII and CRC formats
*
*/
#include "libbb.h"
#include "unarchive.h"
enum {
CPIO_OPT_EXTRACT = (1 << 0),
CPIO_OPT_TEST = (1 << 1),
CPIO_OPT_UNCONDITIONAL = (1 << 2),
CPIO_OPT_VERBOSE = (1 << 3),
CPIO_OPT_FILE = (1 << 4),
CPIO_OPT_CREATE_LEADING_DIR = (1 << 5),
CPIO_OPT_PRESERVE_MTIME = (1 << 6),
CPIO_OPT_CREATE = (1 << 7),
CPIO_OPT_FORMAT = (1 << 8),
};
#if ENABLE_FEATURE_CPIO_O
static off_t cpio_pad4(off_t size)
{
int i;
i = (- size) & 3;
size += i;
while (--i >= 0)
bb_putchar('\0');
return size;
}
/* Return value will become exit code.
* It's ok to exit instead of return. */
static int cpio_o(void)
{
struct name_s {
struct name_s *next;
char name[1];
};
struct inodes_s {
struct inodes_s *next;
struct name_s *names;
struct stat st;
};
struct inodes_s *links = NULL;
off_t bytes = 0; /* output bytes count */
while (1) {
const char *name;
char *line;
struct stat st;
line = xmalloc_fgetline(stdin);
if (line) {
/* Strip leading "./[./]..." from the filename */
name = line;
while (name[0] == '.' && name[1] == '/') {
while (*++name == '/')
continue;
}
if (!*name) { /* line is empty */
free(line);
continue;
}
if (lstat(name, &st)) {
abort_cpio_o:
bb_simple_perror_msg_and_die(name);
}
if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
st.st_size = 0; /* paranoia */
/* Store hardlinks for later processing, dont output them */
if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
struct name_s *n;
struct inodes_s *l;
/* Do we have this hardlink remembered? */
l = links;
while (1) {
if (l == NULL) {
/* Not found: add new item to "links" list */
l = xzalloc(sizeof(*l));
l->st = st;
l->next = links;
links = l;
break;
}
if (l->st.st_ino == st.st_ino) {
/* found */
break;
}
l = l->next;
}
/* Add new name to "l->names" list */
n = xmalloc(sizeof(*n) + strlen(name));
strcpy(n->name, name);
n->next = l->names;
l->names = n;
free(line);
continue;
}
} else { /* line == NULL: EOF */
next_link:
if (links) {
/* Output hardlink's data */
st = links->st;
name = links->names->name;
links->names = links->names->next;
/* GNU cpio is reported to emit file data
* only for the last instance. Mimic that. */
if (links->names == NULL)
links = links->next;
else
st.st_size = 0;
/* NB: we leak links->names and/or links,
* this is intended (we exit soon anyway) */
} else {
/* If no (more) hardlinks to output,
* output "trailer" entry */
name = "TRAILER!!!";
/* st.st_size == 0 is a must, but for uniformity
* in the output, we zero out everything */
memset(&st, 0, sizeof(st));
/* st.st_nlink = 1; - GNU cpio does this */
}
}
bytes += printf("070701"
"%08X%08X%08X%08X%08X%08X%08X"
"%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
/* strlen+1: */ "%08X"
/* chksum: */ "00000000" /* (only for "070702" files) */
/* name,NUL: */ "%s%c",
(unsigned)(uint32_t) st.st_ino,
(unsigned)(uint32_t) st.st_mode,
(unsigned)(uint32_t) st.st_uid,
(unsigned)(uint32_t) st.st_gid,
(unsigned)(uint32_t) st.st_nlink,
(unsigned)(uint32_t) st.st_mtime,
(unsigned)(uint32_t) st.st_size,
(unsigned)(uint32_t) major(st.st_dev),
(unsigned)(uint32_t) minor(st.st_dev),
(unsigned)(uint32_t) major(st.st_rdev),
(unsigned)(uint32_t) minor(st.st_rdev),
(unsigned)(strlen(name) + 1),
name, '\0');
bytes = cpio_pad4(bytes);
if (st.st_size) {
if (S_ISLNK(st.st_mode)) {
char *lpath = xmalloc_readlink_or_warn(name);
if (!lpath)
goto abort_cpio_o;
bytes += printf("%s", lpath);
free(lpath);
} else { /* S_ISREG */
int fd = xopen(name, O_RDONLY);
fflush(stdout);
/* We must abort if file got shorter too! */
bb_copyfd_exact_size(fd, STDOUT_FILENO, st.st_size);
bytes += st.st_size;
close(fd);
}
bytes = cpio_pad4(bytes);
}
if (!line) {
if (links)
goto next_link;
/* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
return EXIT_SUCCESS;
}
free(line);
} /* end of "while (1)" */
}
#endif
int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cpio_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
archive_handle_t *archive_handle;
char *cpio_filename;
#if ENABLE_FEATURE_CPIO_O
const char *cpio_fmt = "";
#endif
unsigned opt;
/* Initialize */
archive_handle = init_handle();
archive_handle->src_fd = STDIN_FILENO;
archive_handle->seek = seek_by_read;
archive_handle->flags = ARCHIVE_EXTRACT_NEWER | ARCHIVE_PRESERVE_DATE;
#if ENABLE_FEATURE_CPIO_O
opt = getopt32(argv, "ituvF:dmoH:", &cpio_filename, &cpio_fmt);
if (opt & CPIO_OPT_CREATE) {
if (*cpio_fmt != 'n')
bb_show_usage();
if (opt & CPIO_OPT_FILE) {
fclose(stdout);
stdout = fopen(cpio_filename, "w");
/* Paranoia: I don't trust libc that much */
xdup2(fileno(stdout), STDOUT_FILENO);
}
return cpio_o();
}
#else
opt = getopt32(argv, "ituvF:dm", &cpio_filename);
#endif
argv += optind;
/* One of either extract or test options must be given */
if ((opt & (CPIO_OPT_TEST | CPIO_OPT_EXTRACT)) == 0) {
bb_show_usage();
}
if (opt & CPIO_OPT_TEST) {
/* if both extract and test options are given, ignore extract option */
if (opt & CPIO_OPT_EXTRACT) {
opt &= ~CPIO_OPT_EXTRACT;
}
archive_handle->action_header = header_list;
}
if (opt & CPIO_OPT_EXTRACT) {
archive_handle->action_data = data_extract_all;
}
if (opt & CPIO_OPT_UNCONDITIONAL) {
archive_handle->flags |= ARCHIVE_EXTRACT_UNCONDITIONAL;
archive_handle->flags &= ~ARCHIVE_EXTRACT_NEWER;
}
if (opt & CPIO_OPT_VERBOSE) {
if (archive_handle->action_header == header_list) {
archive_handle->action_header = header_verbose_list;
} else {
archive_handle->action_header = header_list;
}
}
if (opt & CPIO_OPT_FILE) { /* -F */
archive_handle->src_fd = xopen(cpio_filename, O_RDONLY);
archive_handle->seek = seek_by_jump;
}
if (opt & CPIO_OPT_CREATE_LEADING_DIR) {
archive_handle->flags |= ARCHIVE_CREATE_LEADING_DIRS;
}
while (*argv) {
archive_handle->filter = filter_accept_list;
llist_add_to(&(archive_handle->accept), *argv);
argv++;
}
while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
continue;
return EXIT_SUCCESS;
}