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busybox/archival/cpio.c
Denys Vlasenko b1a2762ecf cpio: fix "cpio -d -p A/B/C" 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-06-03 20:26:30 +02:00

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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 source tree.
*
* Limitations:
* Doesn't check CRC's
* Only supports new ASCII and CRC formats
*/
//config:config CPIO
//config: bool "cpio (15 kb)"
//config: default y
//config: help
//config: cpio is an archival utility program used to create, modify, and
//config: extract contents from archives.
//config: cpio has 110 bytes of overheads for every stored file.
//config:
//config: This implementation of cpio can extract cpio archives created in the
//config: "newc" or "crc" format.
//config:
//config: Unless you have a specific application which requires cpio, you
//config: should probably say N here.
//config:
//config:config FEATURE_CPIO_O
//config: bool "Support archive creation"
//config: default y
//config: depends on CPIO
//config: help
//config: This implementation of cpio can create cpio archives in the "newc"
//config: format only.
//config:
//config:config FEATURE_CPIO_P
//config: bool "Support passthrough mode"
//config: default y
//config: depends on FEATURE_CPIO_O
//config: help
//config: Passthrough mode. Rarely used.
//applet:IF_CPIO(APPLET(cpio, BB_DIR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_CPIO) += cpio.o
//usage:#define cpio_trivial_usage
//usage: "[-dmvu] [-F FILE] [-R USER[:GRP]]" IF_FEATURE_CPIO_O(" [-H newc]")
//usage: " [-ti"IF_FEATURE_CPIO_O("o")"]" IF_FEATURE_CPIO_P(" [-p DIR]")
//usage: " [EXTR_FILE]..."
//usage:#define cpio_full_usage "\n\n"
//usage: "Extract (-i) or list (-t) files from a cpio archive"
//usage: IF_FEATURE_CPIO_O(", or"
//usage: "\ntake file list from stdin and create an archive (-o)"
//usage: IF_FEATURE_CPIO_P(" or copy files (-p)")
//usage: )
//usage: "\n"
//usage: "\nMain operation mode:"
//usage: "\n -t List"
//usage: "\n -i Extract EXTR_FILEs (or all)"
//usage: IF_FEATURE_CPIO_O(
//usage: "\n -o Create (requires -H newc)"
//usage: )
//usage: IF_FEATURE_CPIO_P(
//usage: "\n -p DIR Copy files to DIR"
//usage: )
//usage: "\nOptions:"
//usage: IF_FEATURE_CPIO_O(
//usage: "\n -H newc Archive format"
//usage: )
//usage: "\n -d Make leading directories"
//usage: "\n -m Restore mtime"
//usage: "\n -v Verbose"
//usage: "\n -u Overwrite"
//usage: "\n -F FILE Input (-t,-i,-p) or output (-o) file"
//usage: "\n -R USER[:GRP] Set owner of created files"
//usage: "\n -L Dereference symlinks"
//usage: "\n -0 Input is separated by NULs"
/* 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
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][:.][GRP] 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
*/
#include "libbb.h"
#include "common_bufsiz.h"
#include "bb_archive.h"
enum {
OPT_EXTRACT = (1 << 0),
OPT_TEST = (1 << 1),
OPT_NUL_TERMINATED = (1 << 2),
OPT_UNCONDITIONAL = (1 << 3),
OPT_VERBOSE = (1 << 4),
OPT_CREATE_LEADING_DIR = (1 << 5),
OPT_PRESERVE_MTIME = (1 << 6),
OPT_DEREF = (1 << 7),
OPT_FILE = (1 << 8),
OPT_OWNER = (1 << 9),
OPTBIT_OWNER = 9,
IF_FEATURE_CPIO_O(OPTBIT_CREATE ,)
IF_FEATURE_CPIO_O(OPTBIT_FORMAT ,)
IF_FEATURE_CPIO_P(OPTBIT_PASSTHROUGH,)
IF_LONG_OPTS( OPTBIT_QUIET ,)
IF_LONG_OPTS( OPTBIT_2STDOUT ,)
OPT_CREATE = IF_FEATURE_CPIO_O((1 << OPTBIT_CREATE )) + 0,
OPT_FORMAT = IF_FEATURE_CPIO_O((1 << OPTBIT_FORMAT )) + 0,
OPT_PASSTHROUGH = IF_FEATURE_CPIO_P((1 << OPTBIT_PASSTHROUGH)) + 0,
OPT_QUIET = IF_LONG_OPTS( (1 << OPTBIT_QUIET )) + 0,
OPT_2STDOUT = IF_LONG_OPTS( (1 << OPTBIT_2STDOUT )) + 0,
};
#define OPTION_STR "it0uvdmLF:R:"
struct globals {
struct bb_uidgid_t owner_ugid;
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
void BUG_cpio_globals_too_big(void);
#define INIT_G() do { \
setup_common_bufsiz(); \
G.owner_ugid.uid = -1L; \
G.owner_ugid.gid = -1L; \
} while (0)
#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 NOINLINE 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 = (option_mask32 & 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 & OPT_DEREF)
? stat(name, &st)
: lstat(name, &st)
) {
abort_cpio_o:
bb_simple_perror_msg_and_die(name);
}
if (G.owner_ugid.uid != (uid_t)-1L)
st.st_uid = G.owner_ugid.uid;
if (G.owner_ugid.gid != (gid_t)-1L)
st.st_gid = G.owner_ugid.gid;
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 = cpio_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_all();
/* 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 != cpio_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;
int cpio_main(int argc UNUSED_PARAM, char **argv)
{
archive_handle_t *archive_handle;
char *cpio_filename;
char *cpio_owner;
IF_FEATURE_CPIO_O(const char *cpio_fmt = "";)
unsigned opt;
#if ENABLE_LONG_OPTS
const char *long_opts =
"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
"owner\0" Required_argument "R"
"verbose\0" No_argument "v"
"null\0" No_argument "0"
"quiet\0" No_argument "\xff"
"to-stdout\0" No_argument "\xfe"
;
#endif
INIT_G();
archive_handle = init_handle();
/* archive_handle->src_fd = STDIN_FILENO; - done by init_handle */
archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
/* 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 = getopt32long(argv, OPTION_STR, long_opts, &cpio_filename, &cpio_owner);
#else
opt = getopt32long(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"), long_opts,
&cpio_filename, &cpio_owner, &cpio_fmt);
#endif
argv += optind;
if (opt & OPT_OWNER) { /* -R */
parse_chown_usergroup_or_die(&G.owner_ugid, cpio_owner);
archive_handle->cpio__owner = G.owner_ugid;
}
#if !ENABLE_FEATURE_CPIO_O
if (opt & OPT_FILE) { /* -F */
xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
}
#else
if ((opt & (OPT_FILE|OPT_CREATE)) == OPT_FILE) { /* -F without -o */
xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
}
if (opt & OPT_PASSTHROUGH) {
pid_t pid;
struct fd_pair pp;
if (argv[0] == NULL)
bb_show_usage();
if (opt & OPT_CREATE_LEADING_DIR)
/* GNU cpio 2.13: "cpio -d -p a/b/c" works */
bb_make_directory(argv[0], -1, FILEUTILS_RECUR);
/* Crude existence check:
* close(xopen(argv[0], 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.
*/
//FIXME: GNU cpio -d -p DIR does not immediately create DIR -
//it just prepends "DIR/" to the names of files to be created.
//The first file (fails to) be copied, and then the -d logic
//triggers and creates all necessary directories.
//IOW: bare "cpio -d -p DIR" + ^C shouldn't create anything.
#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 - optind);
if (pid == 0) { /* child */
close(pp.rd);
xmove_fd(pp.wr, STDOUT_FILENO);
goto dump;
}
/* parent */
USE_FOR_NOMMU(argv[-optind][0] &= 0x7f); /* undo fork_or_rexec() damage */
xchdir(*argv++);
close(pp.wr);
xmove_fd(pp.rd, STDIN_FILENO);
//opt &= ~OPT_PASSTHROUGH;
opt |= OPT_EXTRACT;
goto skip;
}
/* -o */
if (opt & OPT_CREATE) {
if (cpio_fmt[0] != 'n') /* we _require_ "-H newc" */
bb_show_usage();
if (opt & OPT_FILE) {
xmove_fd(xopen(cpio_filename, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
}
dump:
return cpio_o();
}
skip:
#endif
/* One of either extract or test options must be given */
if ((opt & (OPT_TEST | OPT_EXTRACT)) == 0) {
bb_show_usage();
}
if (opt & OPT_TEST) {
/* if both extract and test options are given, ignore extract option */
opt &= ~OPT_EXTRACT;
archive_handle->action_header = header_list;
}
if (opt & OPT_EXTRACT) {
archive_handle->action_data = data_extract_all;
if (opt & OPT_2STDOUT)
archive_handle->action_data = data_extract_to_stdout;
}
if (opt & OPT_UNCONDITIONAL) {
archive_handle->ah_flags |= ARCHIVE_UNLINK_OLD;
archive_handle->ah_flags &= ~ARCHIVE_EXTRACT_NEWER;
}
if (opt & 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 & OPT_CREATE_LEADING_DIR) {
archive_handle->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
}
if (opt & OPT_PRESERVE_MTIME) {
archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
}
while (*argv) {
archive_handle->filter = filter_accept_list;
llist_add_to(&archive_handle->accept, *argv);
argv++;
}
/* see get_header_cpio */
archive_handle->cpio__blocks = (off_t)-1;
while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
continue;
create_links_from_list(archive_handle->link_placeholders);
if (archive_handle->cpio__blocks != (off_t)-1
&& !(opt & OPT_QUIET)
) {
fflush_all();
fprintf(stderr, "%"OFF_FMT"u blocks\n", archive_handle->cpio__blocks);
}
return EXIT_SUCCESS;
}
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