busybox/archival/cpio.c

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/* 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"
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#include "unarchive.h"
/* GNU cpio 2.9 --help (abridged):
Modes:
-t, --list List the archive
-i, --extract Extract files from an archive
-o, --create Create the archive
-p, --pass-through Copy-pass mode [was ist das?!]
Options valid in any mode:
--block-size=SIZE I/O block size = SIZE * 512 bytes
-B I/O block size = 5120 bytes
-c Use the old portable (ASCII) archive format
-C, --io-size=NUMBER I/O block size in bytes
-f, --nonmatching Only copy files that do not match given pattern
-F, --file=FILE Use FILE instead of standard input or output
-H, --format=FORMAT Use given archive FORMAT
-M, --message=STRING Print STRING when the end of a volume of the
backup media is reached
-n, --numeric-uid-gid If -v, show numeric UID and GID
--quiet Do not print the number of blocks copied
--rsh-command=COMMAND Use remote COMMAND instead of rsh
-v, --verbose Verbosely list the files processed
-V, --dot Print a "." for each file processed
-W, --warning=FLAG Control warning display: 'none','truncate','all';
multiple options accumulate
Options valid only in --extract mode:
-b, --swap Swap both halfwords of words and bytes of
halfwords in the data (equivalent to -sS)
-r, --rename Interactively rename files
-s, --swap-bytes Swap the bytes of each halfword in the files
-S, --swap-halfwords Swap the halfwords of each word (4 bytes)
--to-stdout Extract files to standard output
-E, --pattern-file=FILE Read additional patterns specifying filenames to
extract or list from FILE
--only-verify-crc Verify CRC's, don't actually extract the files
Options valid only in --create mode:
-A, --append Append to an existing archive
-O FILE File to use instead of standard output
Options valid only in --pass-through mode:
-l, --link Link files instead of copying them, when possible
Options valid in --extract and --create modes:
--absolute-filenames Do not strip file system prefix components from
the file names
--no-absolute-filenames Create all files relative to the current dir
Options valid in --create and --pass-through modes:
-0, --null A list of filenames is terminated by a NUL
-a, --reset-access-time Reset the access times of files after reading them
-I FILE File to use instead of standard input
-L, --dereference Dereference symbolic links (copy the files
that they point to instead of copying the links)
-R, --owner=[USER][:.][GROUP] Set owner of created files
Options valid in --extract and --pass-through modes:
-d, --make-directories Create leading directories where needed
-m, --preserve-modification-time Retain mtime when creating files
--no-preserve-owner Do not change the ownership of the files
--sparse Write files with blocks of zeros as sparse files
-u, --unconditional Replace all files unconditionally
*/
enum {
CPIO_OPT_EXTRACT = (1 << 0),
CPIO_OPT_TEST = (1 << 1),
CPIO_OPT_NUL_TERMINATED = (1 << 2),
CPIO_OPT_UNCONDITIONAL = (1 << 3),
CPIO_OPT_VERBOSE = (1 << 4),
CPIO_OPT_CREATE_LEADING_DIR = (1 << 5),
CPIO_OPT_PRESERVE_MTIME = (1 << 6),
CPIO_OPT_DEREF = (1 << 7),
CPIO_OPT_FILE = (1 << 8),
CPIO_OPT_CREATE = (1 << 9) * ENABLE_FEATURE_CPIO_O,
CPIO_OPT_FORMAT = (1 << 10) * ENABLE_FEATURE_CPIO_O,
CPIO_OPT_PASSTHROUGH = (1 << 11) * ENABLE_FEATURE_CPIO_P,
};
#define OPTION_STR "it0uvdmLF:"
#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)
{
static const char trailer[] ALIGN1 = "TRAILER!!!";
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 = (option_mask32 & CPIO_OPT_NUL_TERMINATED)
? bb_get_chunk_from_file(stdin, NULL)
: 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 ((option_mask32 & CPIO_OPT_DEREF)
? stat(name, &st)
: 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 (name != trailer)
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;
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int cpio_main(int argc UNUSED_PARAM, char **argv)
{
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archive_handle_t *archive_handle;
char *cpio_filename;
IF_FEATURE_CPIO_O(const char *cpio_fmt = "";)
unsigned opt;
#if ENABLE_LONG_OPTS
applet_long_options =
"extract\0" No_argument "i"
"list\0" No_argument "t"
#if ENABLE_FEATURE_CPIO_O
"create\0" No_argument "o"
"format\0" Required_argument "H"
#if ENABLE_FEATURE_CPIO_P
"pass-through\0" No_argument "p"
#endif
#endif
;
#endif
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/* As of now we do not enforce this: */
/* -i,-t,-o,-p are mutually exclusive */
/* -u,-d,-m make sense only with -i or -p */
/* -L makes sense only with -o or -p */
#if !ENABLE_FEATURE_CPIO_O
opt = getopt32(argv, OPTION_STR, &cpio_filename);
#else
opt = getopt32(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"), &cpio_filename, &cpio_fmt);
if (opt & CPIO_OPT_PASSTHROUGH) {
pid_t pid;
struct fd_pair pp;
if (argv[optind] == NULL)
bb_show_usage();
if (opt & CPIO_OPT_CREATE_LEADING_DIR)
mkdir(argv[optind], 0777);
/* Crude existence check:
* close(xopen(argv[optind], O_RDONLY | O_DIRECTORY));
* We can also xopen, fstat, IS_DIR, later fchdir.
* This would check for existence earlier and cleaner.
* As it stands now, if we fail xchdir later,
* child dies on EPIPE, unless it caught
* a diffrerent problem earlier.
* This is good enough for now.
*/
#if !BB_MMU
pp.rd = 3;
pp.wr = 4;
if (!re_execed) {
close(3);
close(4);
xpiped_pair(pp);
}
#else
xpiped_pair(pp);
#endif
pid = fork_or_rexec(argv);
if (pid == 0) { /* child */
close(pp.rd);
xmove_fd(pp.wr, STDOUT_FILENO);
goto dump;
}
/* parent */
xchdir(argv[optind++]);
close(pp.wr);
xmove_fd(pp.rd, STDIN_FILENO);
opt &= ~CPIO_OPT_PASSTHROUGH;
opt |= CPIO_OPT_EXTRACT;
goto skip;
}
/* -o */
if (opt & CPIO_OPT_CREATE) {
if (*cpio_fmt != 'n') /* we _require_ "-H newc" */
bb_show_usage();
if (opt & CPIO_OPT_FILE) {
fclose(stdout);
stdout = fopen_for_write(cpio_filename);
/* Paranoia: I don't trust libc that much */
xdup2(fileno(stdout), STDOUT_FILENO);
}
dump:
return cpio_o();
}
skip:
#endif
argv += optind;
archive_handle = init_handle();
archive_handle->src_fd = STDIN_FILENO;
archive_handle->seek = seek_by_read;
archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
/* 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 */
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->ah_flags |= ARCHIVE_EXTRACT_UNCONDITIONAL;
archive_handle->ah_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->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
}
if (opt & CPIO_OPT_PRESERVE_MTIME) {
archive_handle->ah_flags |= ARCHIVE_PRESERVE_DATE;
}
while (*argv) {
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archive_handle->filter = filter_accept_list;
llist_add_to(&(archive_handle->accept), *argv);
argv++;
}
/* see get_header_cpio */
archive_handle->ah_priv[2] = (void*) ~(ptrdiff_t)0;
while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
continue;
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if (archive_handle->ah_priv[2] != (void*) ~(ptrdiff_t)0)
printf("%lu blocks\n", (unsigned long)(ptrdiff_t)(archive_handle->ah_priv[2]));
return EXIT_SUCCESS;
}