LXR busybox/archival/cpio.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Mini cpio implementation for busybox
   4 *
   5 * Copyright (C) 2001 by Glenn McGrath
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8 *
   9 * Limitations:
  10 * Doesn't check CRC's
  11 * Only supports new ASCII and CRC formats
  12 */
  13//config:config CPIO
  14//config:       bool "cpio (15 kb)"
  15//config:       default y
  16//config:       help
  17//config:       cpio is an archival utility program used to create, modify, and
  18//config:       extract contents from archives.
  19//config:       cpio has 110 bytes of overheads for every stored file.
  20//config:
  21//config:       This implementation of cpio can extract cpio archives created in the
  22//config:       "newc" or "crc" format.
  23//config:
  24//config:       Unless you have a specific application which requires cpio, you
  25//config:       should probably say N here.
  26//config:
  27//config:config FEATURE_CPIO_O
  28//config:       bool "Support archive creation"
  29//config:       default y
  30//config:       depends on CPIO
  31//config:       help
  32//config:       This implementation of cpio can create cpio archives in the "newc"
  33//config:       format only.
  34//config:
  35//config:config FEATURE_CPIO_P
  36//config:       bool "Support passthrough mode"
  37//config:       default y
  38//config:       depends on FEATURE_CPIO_O
  39//config:       help
  40//config:       Passthrough mode. Rarely used.
  41
  42//applet:IF_CPIO(APPLET(cpio, BB_DIR_BIN, BB_SUID_DROP))
  43
  44//kbuild:lib-$(CONFIG_CPIO) += cpio.o
  45
  46//usage:#define cpio_trivial_usage
  47//usage:       "[-dmvu] [-F FILE] [-R USER[:GRP]]" IF_FEATURE_CPIO_O(" [-H newc]")
  48//usage:       " [-ti"IF_FEATURE_CPIO_O("o")"]" IF_FEATURE_CPIO_P(" [-p DIR]")
  49//usage:       " [EXTR_FILE]..."
  50//usage:#define cpio_full_usage "\n\n"
  51//usage:       "Extract (-i) or list (-t) files from a cpio archive"
  52//usage:        IF_FEATURE_CPIO_O(", or"
  53//usage:     "\ntake file list from stdin and create an archive (-o)"
  54//usage:                IF_FEATURE_CPIO_P(" or copy files (-p)")
  55//usage:        )
  56//usage:     "\n"
  57//usage:     "\nMain operation mode:"
  58//usage:     "\n        -t      List"
  59//usage:     "\n        -i      Extract EXTR_FILEs (or all)"
  60//usage:        IF_FEATURE_CPIO_O(
  61//usage:     "\n        -o      Create (requires -H newc)"
  62//usage:        )
  63//usage:        IF_FEATURE_CPIO_P(
  64//usage:     "\n        -p DIR  Copy files to DIR"
  65//usage:        )
  66//usage:     "\nOptions:"
  67//usage:        IF_FEATURE_CPIO_O(
  68//usage:     "\n        -H newc Archive format"
  69//usage:        )
  70//usage:     "\n        -d      Make leading directories"
  71//usage:     "\n        -m      Preserve mtime"
  72//usage:     "\n        -v      Verbose"
  73//usage:     "\n        -u      Overwrite"
  74//usage:     "\n        -F FILE Input (-t,-i,-p) or output (-o) file"
  75//usage:     "\n        -R USER[:GRP]   Set owner of created files"
  76//usage:     "\n        -L      Dereference symlinks"
  77//usage:     "\n        -0      Input is separated by NULs"
  78
  79/* GNU cpio 2.9 --help (abridged):
  80
  81 Modes:
  82  -t, --list                 List the archive
  83  -i, --extract              Extract files from an archive
  84  -o, --create               Create the archive
  85  -p, --pass-through         Copy-pass mode
  86
  87 Options valid in any mode:
  88      --block-size=SIZE      I/O block size = SIZE * 512 bytes
  89  -B                         I/O block size = 5120 bytes
  90  -c                         Use the old portable (ASCII) archive format
  91  -C, --io-size=NUMBER       I/O block size in bytes
  92  -f, --nonmatching          Only copy files that do not match given pattern
  93  -F, --file=FILE            Use FILE instead of standard input or output
  94  -H, --format=FORMAT        Use given archive FORMAT
  95  -M, --message=STRING       Print STRING when the end of a volume of the
  96                             backup media is reached
  97  -n, --numeric-uid-gid      If -v, show numeric UID and GID
  98      --quiet                Do not print the number of blocks copied
  99      --rsh-command=COMMAND  Use remote COMMAND instead of rsh
 100  -v, --verbose              Verbosely list the files processed
 101  -V, --dot                  Print a "." for each file processed
 102  -W, --warning=FLAG         Control warning display: 'none','truncate','all';
 103                             multiple options accumulate
 104
 105 Options valid only in --extract mode:
 106  -b, --swap                 Swap both halfwords of words and bytes of
 107                             halfwords in the data (equivalent to -sS)
 108  -r, --rename               Interactively rename files
 109  -s, --swap-bytes           Swap the bytes of each halfword in the files
 110  -S, --swap-halfwords       Swap the halfwords of each word (4 bytes)
 111      --to-stdout            Extract files to standard output
 112  -E, --pattern-file=FILE    Read additional patterns specifying filenames to
 113                             extract or list from FILE
 114      --only-verify-crc      Verify CRC's, don't actually extract the files
 115
 116 Options valid only in --create mode:
 117  -A, --append               Append to an existing archive
 118  -O FILE                    File to use instead of standard output
 119
 120 Options valid only in --pass-through mode:
 121  -l, --link                 Link files instead of copying them, when possible
 122
 123 Options valid in --extract and --create modes:
 124      --absolute-filenames   Do not strip file system prefix components from
 125                             the file names
 126      --no-absolute-filenames Create all files relative to the current dir
 127
 128 Options valid in --create and --pass-through modes:
 129  -0, --null                 A list of filenames is terminated by a NUL
 130  -a, --reset-access-time    Reset the access times of files after reading them
 131  -I FILE                    File to use instead of standard input
 132  -L, --dereference          Dereference symbolic links (copy the files
 133                             that they point to instead of copying the links)
 134  -R, --owner=[USER][:.][GRP] Set owner of created files
 135
 136 Options valid in --extract and --pass-through modes:
 137  -d, --make-directories     Create leading directories where needed
 138  -m, --preserve-modification-time  Retain mtime when creating files
 139      --no-preserve-owner    Do not change the ownership of the files
 140      --sparse               Write files with blocks of zeros as sparse files
 141  -u, --unconditional        Replace all files unconditionally
 142 */
 143
 144#include "libbb.h"
 145#include "common_bufsiz.h"
 146#include "bb_archive.h"
 147
 148enum {
 149        OPT_EXTRACT            = (1 << 0),
 150        OPT_TEST               = (1 << 1),
 151        OPT_NUL_TERMINATED     = (1 << 2),
 152        OPT_UNCONDITIONAL      = (1 << 3),
 153        OPT_VERBOSE            = (1 << 4),
 154        OPT_CREATE_LEADING_DIR = (1 << 5),
 155        OPT_PRESERVE_MTIME     = (1 << 6),
 156        OPT_DEREF              = (1 << 7),
 157        OPT_FILE               = (1 << 8),
 158        OPT_OWNER              = (1 << 9),
 159        OPTBIT_OWNER = 9,
 160        IF_FEATURE_CPIO_O(OPTBIT_CREATE     ,)
 161        IF_FEATURE_CPIO_O(OPTBIT_FORMAT     ,)
 162        IF_FEATURE_CPIO_P(OPTBIT_PASSTHROUGH,)
 163        IF_LONG_OPTS(     OPTBIT_QUIET      ,)
 164        IF_LONG_OPTS(     OPTBIT_2STDOUT    ,)
 165        OPT_CREATE             = IF_FEATURE_CPIO_O((1 << OPTBIT_CREATE     )) + 0,
 166        OPT_FORMAT             = IF_FEATURE_CPIO_O((1 << OPTBIT_FORMAT     )) + 0,
 167        OPT_PASSTHROUGH        = IF_FEATURE_CPIO_P((1 << OPTBIT_PASSTHROUGH)) + 0,
 168        OPT_QUIET              = IF_LONG_OPTS(     (1 << OPTBIT_QUIET      )) + 0,
 169        OPT_2STDOUT            = IF_LONG_OPTS(     (1 << OPTBIT_2STDOUT    )) + 0,
 170};
 171
 172#define OPTION_STR "it0uvdmLF:R:"
 173
 174struct globals {
 175        struct bb_uidgid_t owner_ugid;
 176} FIX_ALIASING;
 177#define G (*(struct globals*)bb_common_bufsiz1)
 178void BUG_cpio_globals_too_big(void);
 179#define INIT_G() do { \
 180        setup_common_bufsiz(); \
 181        G.owner_ugid.uid = -1L; \
 182        G.owner_ugid.gid = -1L; \
 183} while (0)
 184
 185#if ENABLE_FEATURE_CPIO_O
 186static off_t cpio_pad4(off_t size)
 187{
 188        int i;
 189
 190        i = (- size) & 3;
 191        size += i;
 192        while (--i >= 0)
 193                bb_putchar('\0');
 194        return size;
 195}
 196
 197/* Return value will become exit code.
 198 * It's ok to exit instead of return. */
 199static NOINLINE int cpio_o(void)
 200{
 201        struct name_s {
 202                struct name_s *next;
 203                char name[1];
 204        };
 205        struct inodes_s {
 206                struct inodes_s *next;
 207                struct name_s *names;
 208                struct stat st;
 209        };
 210
 211        struct inodes_s *links = NULL;
 212        off_t bytes = 0; /* output bytes count */
 213
 214        while (1) {
 215                const char *name;
 216                char *line;
 217                struct stat st;
 218
 219                line = (option_mask32 & OPT_NUL_TERMINATED)
 220                                ? bb_get_chunk_from_file(stdin, NULL)
 221                                : xmalloc_fgetline(stdin);
 222
 223                if (line) {
 224                        /* Strip leading "./[./]..." from the filename */
 225                        name = line;
 226                        while (name[0] == '.' && name[1] == '/') {
 227                                while (*++name == '/')
 228                                        continue;
 229                        }
 230                        if (!*name) { /* line is empty */
 231                                free(line);
 232                                continue;
 233                        }
 234                        if ((option_mask32 & OPT_DEREF)
 235                                        ? stat(name, &st)
 236                                        : lstat(name, &st)
 237                        ) {
 238 abort_cpio_o:
 239                                bb_simple_perror_msg_and_die(name);
 240                        }
 241
 242                        if (G.owner_ugid.uid != (uid_t)-1L)
 243                                st.st_uid = G.owner_ugid.uid;
 244                        if (G.owner_ugid.gid != (gid_t)-1L)
 245                                st.st_gid = G.owner_ugid.gid;
 246
 247                        if (!(S_ISLNK(st.st_mode) || S_ISREG(st.st_mode)))
 248                                st.st_size = 0; /* paranoia */
 249
 250                        /* Store hardlinks for later processing, dont output them */
 251                        if (!S_ISDIR(st.st_mode) && st.st_nlink > 1) {
 252                                struct name_s *n;
 253                                struct inodes_s *l;
 254
 255                                /* Do we have this hardlink remembered? */
 256                                l = links;
 257                                while (1) {
 258                                        if (l == NULL) {
 259                                                /* Not found: add new item to "links" list */
 260                                                l = xzalloc(sizeof(*l));
 261                                                l->st = st;
 262                                                l->next = links;
 263                                                links = l;
 264                                                break;
 265                                        }
 266                                        if (l->st.st_ino == st.st_ino) {
 267                                                /* found */
 268                                                break;
 269                                        }
 270                                        l = l->next;
 271                                }
 272                                /* Add new name to "l->names" list */
 273                                n = xmalloc(sizeof(*n) + strlen(name));
 274                                strcpy(n->name, name);
 275                                n->next = l->names;
 276                                l->names = n;
 277
 278                                free(line);
 279                                continue;
 280                        }
 281                } else { /* line == NULL: EOF */
 282 next_link:
 283                        if (links) {
 284                                /* Output hardlink's data */
 285                                st = links->st;
 286                                name = links->names->name;
 287                                links->names = links->names->next;
 288                                /* GNU cpio is reported to emit file data
 289                                 * only for the last instance. Mimic that. */
 290                                if (links->names == NULL)
 291                                        links = links->next;
 292                                else
 293                                        st.st_size = 0;
 294                                /* NB: we leak links->names and/or links,
 295                                 * this is intended (we exit soon anyway) */
 296                        } else {
 297                                /* If no (more) hardlinks to output,
 298                                 * output "trailer" entry */
 299                                name = cpio_TRAILER;
 300                                /* st.st_size == 0 is a must, but for uniformity
 301                                 * in the output, we zero out everything */
 302                                memset(&st, 0, sizeof(st));
 303                                /* st.st_nlink = 1; - GNU cpio does this */
 304                        }
 305                }
 306
 307                bytes += printf("070701"
 308                                "%08X%08X%08X%08X%08X%08X%08X"
 309                                "%08X%08X%08X%08X" /* GNU cpio uses uppercase hex */
 310                                /* strlen+1: */ "%08X"
 311                                /* chksum: */   "00000000" /* (only for "070702" files) */
 312                                /* name,NUL: */ "%s%c",
 313                                (unsigned)(uint32_t) st.st_ino,
 314                                (unsigned)(uint32_t) st.st_mode,
 315                                (unsigned)(uint32_t) st.st_uid,
 316                                (unsigned)(uint32_t) st.st_gid,
 317                                (unsigned)(uint32_t) st.st_nlink,
 318                                (unsigned)(uint32_t) st.st_mtime,
 319                                (unsigned)(uint32_t) st.st_size,
 320                                (unsigned)(uint32_t) major(st.st_dev),
 321                                (unsigned)(uint32_t) minor(st.st_dev),
 322                                (unsigned)(uint32_t) major(st.st_rdev),
 323                                (unsigned)(uint32_t) minor(st.st_rdev),
 324                                (unsigned)(strlen(name) + 1),
 325                                name, '\0');
 326                bytes = cpio_pad4(bytes);
 327
 328                if (st.st_size) {
 329                        if (S_ISLNK(st.st_mode)) {
 330                                char *lpath = xmalloc_readlink_or_warn(name);
 331                                if (!lpath)
 332                                        goto abort_cpio_o;
 333                                bytes += printf("%s", lpath);
 334                                free(lpath);
 335                        } else { /* S_ISREG */
 336                                int fd = xopen(name, O_RDONLY);
 337                                fflush_all();
 338                                /* We must abort if file got shorter too! */
 339                                bb_copyfd_exact_size(fd, STDOUT_FILENO, st.st_size);
 340                                bytes += st.st_size;
 341                                close(fd);
 342                        }
 343                        bytes = cpio_pad4(bytes);
 344                }
 345
 346                if (!line) {
 347                        if (name != cpio_TRAILER)
 348                                goto next_link;
 349                        /* TODO: GNU cpio pads trailer to 512 bytes, do we want that? */
 350                        return EXIT_SUCCESS;
 351                }
 352
 353                free(line);
 354        } /* end of "while (1)" */
 355}
 356#endif
 357
 358int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 359int cpio_main(int argc UNUSED_PARAM, char **argv)
 360{
 361        archive_handle_t *archive_handle;
 362        char *cpio_filename;
 363        char *cpio_owner;
 364        IF_FEATURE_CPIO_O(const char *cpio_fmt = "";)
 365        unsigned opt;
 366#if ENABLE_LONG_OPTS
 367        const char *long_opts =
 368                "extract\0"      No_argument       "i"
 369                "list\0"         No_argument       "t"
 370#if ENABLE_FEATURE_CPIO_O
 371                "create\0"       No_argument       "o"
 372                "format\0"       Required_argument "H"
 373#if ENABLE_FEATURE_CPIO_P
 374                "pass-through\0" No_argument       "p"
 375#endif
 376#endif
 377                "owner\0"        Required_argument "R"
 378                "verbose\0"      No_argument       "v"
 379                "null\0"         No_argument       "0"
 380                "quiet\0"        No_argument       "\xff"
 381                "to-stdout\0"    No_argument       "\xfe"
 382                ;
 383#endif
 384
 385        INIT_G();
 386        archive_handle = init_handle();
 387        /* archive_handle->src_fd = STDIN_FILENO; - done by init_handle */
 388        archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
 389
 390        /* As of now we do not enforce this: */
 391        /* -i,-t,-o,-p are mutually exclusive */
 392        /* -u,-d,-m make sense only with -i or -p */
 393        /* -L makes sense only with -o or -p */
 394
 395#if !ENABLE_FEATURE_CPIO_O
 396        opt = getopt32long(argv, OPTION_STR, long_opts, &cpio_filename, &cpio_owner);
 397#else
 398        opt = getopt32long(argv, OPTION_STR "oH:" IF_FEATURE_CPIO_P("p"), long_opts,
 399                       &cpio_filename, &cpio_owner, &cpio_fmt);
 400#endif
 401        argv += optind;
 402        if (opt & OPT_OWNER) { /* -R */
 403                parse_chown_usergroup_or_die(&G.owner_ugid, cpio_owner);
 404                archive_handle->cpio__owner = G.owner_ugid;
 405        }
 406#if !ENABLE_FEATURE_CPIO_O
 407        if (opt & OPT_FILE) { /* -F */
 408                xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
 409        }
 410#else
 411        if ((opt & (OPT_FILE|OPT_CREATE)) == OPT_FILE) { /* -F without -o */
 412                xmove_fd(xopen(cpio_filename, O_RDONLY), STDIN_FILENO);
 413        }
 414        if (opt & OPT_PASSTHROUGH) {
 415                pid_t pid;
 416                struct fd_pair pp;
 417
 418                if (argv[0] == NULL)
 419                        bb_show_usage();
 420                if (opt & OPT_CREATE_LEADING_DIR)
 421                        mkdir(argv[0], 0777);
 422                /* Crude existence check:
 423                 * close(xopen(argv[0], O_RDONLY | O_DIRECTORY));
 424                 * We can also xopen, fstat, IS_DIR, later fchdir.
 425                 * This would check for existence earlier and cleaner.
 426                 * As it stands now, if we fail xchdir later,
 427                 * child dies on EPIPE, unless it caught
 428                 * a diffrerent problem earlier.
 429                 * This is good enough for now.
 430                 */
 431#if !BB_MMU
 432                pp.rd = 3;
 433                pp.wr = 4;
 434                if (!re_execed) {
 435                        close(3);
 436                        close(4);
 437                        xpiped_pair(pp);
 438                }
 439#else
 440                xpiped_pair(pp);
 441#endif
 442                pid = fork_or_rexec(argv - optind);
 443                if (pid == 0) { /* child */
 444                        close(pp.rd);
 445                        xmove_fd(pp.wr, STDOUT_FILENO);
 446                        goto dump;
 447                }
 448                /* parent */
 449                USE_FOR_NOMMU(argv[-optind][0] &= 0x7f); /* undo fork_or_rexec() damage */
 450                xchdir(*argv++);
 451                close(pp.wr);
 452                xmove_fd(pp.rd, STDIN_FILENO);
 453                //opt &= ~OPT_PASSTHROUGH;
 454                opt |= OPT_EXTRACT;
 455                goto skip;
 456        }
 457        /* -o */
 458        if (opt & OPT_CREATE) {
 459                if (cpio_fmt[0] != 'n') /* we _require_ "-H newc" */
 460                        bb_show_usage();
 461                if (opt & OPT_FILE) {
 462                        xmove_fd(xopen(cpio_filename, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
 463                }
 464 dump:
 465                return cpio_o();
 466        }
 467 skip:
 468#endif
 469
 470        /* One of either extract or test options must be given */
 471        if ((opt & (OPT_TEST | OPT_EXTRACT)) == 0) {
 472                bb_show_usage();
 473        }
 474
 475        if (opt & OPT_TEST) {
 476                /* if both extract and test options are given, ignore extract option */
 477                opt &= ~OPT_EXTRACT;
 478                archive_handle->action_header = header_list;
 479        }
 480        if (opt & OPT_EXTRACT) {
 481                archive_handle->action_data = data_extract_all;
 482                if (opt & OPT_2STDOUT)
 483                        archive_handle->action_data = data_extract_to_stdout;
 484        }
 485        if (opt & OPT_UNCONDITIONAL) {
 486                archive_handle->ah_flags |= ARCHIVE_UNLINK_OLD;
 487                archive_handle->ah_flags &= ~ARCHIVE_EXTRACT_NEWER;
 488        }
 489        if (opt & OPT_VERBOSE) {
 490                if (archive_handle->action_header == header_list) {
 491                        archive_handle->action_header = header_verbose_list;
 492                } else {
 493                        archive_handle->action_header = header_list;
 494                }
 495        }
 496        if (opt & OPT_CREATE_LEADING_DIR) {
 497                archive_handle->ah_flags |= ARCHIVE_CREATE_LEADING_DIRS;
 498        }
 499        if (opt & OPT_PRESERVE_MTIME) {
 500                archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
 501        }
 502
 503        while (*argv) {
 504                archive_handle->filter = filter_accept_list;
 505                llist_add_to(&archive_handle->accept, *argv);
 506                argv++;
 507        }
 508
 509        /* see get_header_cpio */
 510        archive_handle->cpio__blocks = (off_t)-1;
 511        while (get_header_cpio(archive_handle) == EXIT_SUCCESS)
 512                continue;
 513
 514        create_links_from_list(archive_handle->link_placeholders);
 515
 516        if (archive_handle->cpio__blocks != (off_t)-1
 517         && !(opt & OPT_QUIET)
 518        ) {
 519                fprintf(stderr, "%"OFF_FMT"u blocks\n", archive_handle->cpio__blocks);
 520        }
 521
 522        return EXIT_SUCCESS;
 523}
 524