vfs/cpio.c

   1 /* Virtual File System: GNU Tar file system.
   2    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007
   3    Free Software Foundation, Inc.
   4
   5    Written by: 2000 Jan Hudec
   6
   7    This program is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Library General Public License
   9    as published by the Free Software Foundation; either version 2 of
  10    the License, or (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU Library General Public License for more details.
  16
  17    You should have received a copy of the GNU Library General Public
  18    License along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  20
  21 /** \file
  22  *  \brief Source: Virtual File System: GNU Tar file system.
  23  *  \author Jan Hudec
  24  *  \date 2000
  25  */
  26
  27 #include <config.h>
  28
  29 #include <errno.h>
  30 #include <fcntl.h>
  31
  32 #include "../src/global.h"
  33
  34 #include "../src/wtools.h"      /* message() */
  35 #include "../src/main.h"        /* print_vfs_message */
  36 #include "../src/unixcompat.h"
  37
  38 #include "utilvfs.h"
  39 #include "vfs-impl.h"
  40 #include "gc.h"                 /* vfs_rmstamp */
  41 #include "xdirentry.h"
  42
  43 enum {
  44     STATUS_START,
  45     STATUS_OK,
  46     STATUS_TRAIL,
  47     STATUS_FAIL,
  48     STATUS_EOF
  49 };
  50
  51 enum {
  52     CPIO_UNKNOWN = 0, /* Not determined yet */
  53     CPIO_BIN,         /* Binary format */
  54     CPIO_BINRE,       /* Binary format, reverse endianity */
  55     CPIO_OLDC,        /* Old ASCII format */
  56     CPIO_NEWC,        /* New ASCII format */
  57     CPIO_CRC          /* New ASCII format + CRC */
  58 };
  59
  60 static struct vfs_class vfs_cpiofs_ops;
  61
  62 struct old_cpio_header
  63 {
  64   unsigned short c_magic;
  65   short c_dev;
  66   unsigned short c_ino;
  67   unsigned short c_mode;
  68   unsigned short c_uid;
  69   unsigned short c_gid;
  70   unsigned short c_nlink;
  71   short c_rdev;
  72   unsigned short c_mtimes[2];
  73   unsigned short c_namesize;
  74   unsigned short c_filesizes[2];
  75 };
  76
  77 struct new_cpio_header
  78 {
  79   unsigned short c_magic;
  80   unsigned long c_ino;
  81   unsigned long c_mode;
  82   unsigned long c_uid;
  83   unsigned long c_gid;
  84   unsigned long c_nlink;
  85   unsigned long c_mtime;
  86   unsigned long c_filesize;
  87   long c_dev;
  88   long c_devmin;
  89   long c_rdev;
  90   long c_rdevmin;
  91   unsigned long c_namesize;
  92   unsigned long c_chksum;
  93 };
  94
  95 struct defer_inode {
  96     struct defer_inode *next;
  97     unsigned long inumber;
  98     unsigned short device;
  99     struct vfs_s_inode *inode;
 100 };
 101
 102 /* FIXME: should be off_t instead of int. */
 103 static int cpio_position;
 104
 105 static int cpio_find_head(struct vfs_class *me, struct vfs_s_super *super);
 106 static int cpio_create_entry(struct vfs_class *me, struct vfs_s_super *super, struct stat *, char *name);
 107 static ssize_t cpio_read_bin_head(struct vfs_class *me, struct vfs_s_super *super);
 108 static ssize_t cpio_read_oldc_head(struct vfs_class *me, struct vfs_s_super *super);
 109 static ssize_t cpio_read_crc_head(struct vfs_class *me, struct vfs_s_super *super);
 110 static ssize_t cpio_read(void *fh, char *buffer, int count);
 111
 112 #define CPIO_POS(super) cpio_position
 113 /* If some time reentrancy should be needed change it to */
 114 /* #define CPIO_POS(super) (super)->u.arch.fd */
 115
 116 #define CPIO_SEEK_SET(super, where) mc_lseek((super)->u.arch.fd, CPIO_POS(super) = (where), SEEK_SET)
 117 #define CPIO_SEEK_CUR(super, where) mc_lseek((super)->u.arch.fd, CPIO_POS(super) += (where), SEEK_SET)
 118
 119 static struct defer_inode *
 120 cpio_defer_find (struct defer_inode *l, struct defer_inode *i)
 121 {
 122     while (l && (l->inumber != i->inumber || l->device != i->device))
 123         l = l->next;
 124     return l;
 125 }
 126
 127 static int cpio_skip_padding(struct vfs_s_super *super)
 128 {
 129     switch(super->u.arch.type) {
 130     case CPIO_BIN:
 131     case CPIO_BINRE:
 132         return CPIO_SEEK_CUR(super, (2 - (CPIO_POS(super) % 2)) % 2);
 133     case CPIO_NEWC:
 134     case CPIO_CRC:
 135         return CPIO_SEEK_CUR(super, (4 - (CPIO_POS(super) % 4)) % 4);
 136     case CPIO_OLDC:
 137         return CPIO_POS(super);
 138     default:
 139         g_assert_not_reached();
 140         return 42; /* & the compiler is happy :-) */
 141     }
 142 }
 143
 144 static void cpio_free_archive(struct vfs_class *me, struct vfs_s_super *super)
 145 {
 146     struct defer_inode *l, *lnext;
 147
 148     (void) me;
 149
 150     if(super->u.arch.fd != -1)
 151         mc_close(super->u.arch.fd);
 152         super->u.arch.fd = -1;
 153     for (l = super->u.arch.deferred; l; l = lnext) {
 154         lnext = l->next;
 155         g_free (l);
 156     }
 157     super->u.arch.deferred = NULL;
 158 }
 159
 160 static int
 161 cpio_open_cpio_file (struct vfs_class *me, struct vfs_s_super *super,
 162                      const char *name)
 163 {
 164     int fd, type;
 165     mode_t mode;
 166     struct vfs_s_inode *root;
 167
 168     if ((fd = mc_open (name, O_RDONLY)) == -1) {
 169         message (D_ERROR, MSG_ERROR, _("Cannot open cpio archive\n%s"), name);
 170         return -1;
 171     }
 172
 173     super->name = g_strdup (name);
 174     super->u.arch.fd = -1;      /* for now */
 175     mc_stat (name, &(super->u.arch.st));
 176     super->u.arch.type = CPIO_UNKNOWN;
 177
 178     type = get_compression_type (fd);
 179     if (type != COMPRESSION_NONE) {
 180         char *s;
 181
 182         mc_close (fd);
 183         s = g_strconcat (name, decompress_extension (type), (char *) NULL);
 184         if ((fd = mc_open (s, O_RDONLY)) == -1) {
 185             message (D_ERROR, MSG_ERROR, _("Cannot open cpio archive\n%s"), s);
 186             g_free (s);
 187             return -1;
 188         }
 189         g_free (s);
 190     }
 191
 192     super->u.arch.fd = fd;
 193     mode = super->u.arch.st.st_mode & 07777;
 194     mode |= (mode & 0444) >> 2; /* set eXec where Read is */
 195     mode |= S_IFDIR;
 196
 197     root = vfs_s_new_inode (me, super, &(super->u.arch.st));
 198     root->st.st_mode = mode;
 199     root->data_offset = -1;
 200     root->st.st_nlink++;
 201     root->st.st_dev = MEDATA->rdev++;
 202
 203     super->root = root;
 204
 205     CPIO_SEEK_SET (super, 0);
 206
 207     return fd;
 208 }
 209
 210 static ssize_t cpio_read_head(struct vfs_class *me, struct vfs_s_super *super)
 211 {
 212     switch(cpio_find_head(me, super)) {
 213     case CPIO_UNKNOWN:
 214         return -1;
 215     case CPIO_BIN:
 216     case CPIO_BINRE:
 217         return cpio_read_bin_head(me, super);
 218     case CPIO_OLDC:
 219         return cpio_read_oldc_head(me, super);
 220     case CPIO_NEWC:
 221     case CPIO_CRC:
 222         return cpio_read_crc_head(me, super);
 223     default:
 224         g_assert_not_reached();
 225         return 42; /* & the compiler is happy :-) */
 226     }
 227 }
 228
 229 #define MAGIC_LENGTH (6) /* How many bytes we have to read ahead */
 230 #define SEEKBACK CPIO_SEEK_CUR(super, ptr - top)
 231 #define RETURN(x) return(super->u.arch.type = (x))
 232 #define TYPEIS(x) ((super->u.arch.type == CPIO_UNKNOWN) || (super->u.arch.type == (x)))
 233 static int cpio_find_head(struct vfs_class *me, struct vfs_s_super *super)
 234 {
 235     char buf[256];
 236     int ptr = 0;
 237     int top;
 238     int tmp;
 239
 240     top = mc_read (super->u.arch.fd, buf, 256);
 241     if (top > 0)
 242         CPIO_POS (super) += top;
 243     for(;;) {
 244         if(ptr + MAGIC_LENGTH >= top) {
 245             if(top > 128) {
 246                 memmove(buf, buf + top - 128, 128);
 247                 ptr -= top - 128;
 248                 top = 128;
 249             }
 250             if((tmp = mc_read(super->u.arch.fd, buf, top)) == 0 || tmp == -1) {
 251                 message (D_ERROR, MSG_ERROR, _("Premature end of cpio archive\n%s"), super->name);
 252                 cpio_free_archive(me, super);
 253                 return CPIO_UNKNOWN;
 254             }
 255             top += tmp;
 256         }
 257         if(TYPEIS(CPIO_BIN) && ((*(unsigned short *)(buf + ptr)) == 070707)) {
 258             SEEKBACK; RETURN(CPIO_BIN);
 259         } else if(TYPEIS(CPIO_BINRE) && ((*(unsigned short *)(buf + ptr)) == GUINT16_SWAP_LE_BE_CONSTANT(070707))) {
 260             SEEKBACK; RETURN(CPIO_BINRE);
 261         } else if(TYPEIS(CPIO_OLDC) && (!strncmp(buf + ptr, "070707", 6))) {
 262             SEEKBACK; RETURN(CPIO_OLDC);
 263         } else if(TYPEIS(CPIO_NEWC) && (!strncmp(buf + ptr, "070701", 6))) {
 264             SEEKBACK; RETURN(CPIO_NEWC);
 265         } else if(TYPEIS(CPIO_CRC) && (!strncmp(buf + ptr, "070702", 6))) {
 266             SEEKBACK; RETURN(CPIO_CRC);
 267         };
 268         ptr++;
 269     }
 270 }
 271 #undef RETURN
 272 #undef SEEKBACK
 273
 274 #define HEAD_LENGTH (26)
 275 static ssize_t cpio_read_bin_head(struct vfs_class *me, struct vfs_s_super *super)
 276 {
 277     union {
 278         struct old_cpio_header buf;
 279         short shorts[HEAD_LENGTH >> 1];
 280     } u;
 281     int len;
 282     char *name;
 283     struct stat st;
 284
 285     if((len = mc_read(super->u.arch.fd, (char *)&u.buf, HEAD_LENGTH)) < HEAD_LENGTH)
 286         return STATUS_EOF;
 287     CPIO_POS(super) += len;
 288     if(super->u.arch.type == CPIO_BINRE) {
 289         int i;
 290         for(i = 0; i < (HEAD_LENGTH >> 1); i++)
 291             u.shorts[i] = GUINT16_SWAP_LE_BE_CONSTANT(u.shorts[i]);
 292     }
 293     g_assert(u.buf.c_magic == 070707);
 294
 295     if (u.buf.c_namesize == 0 || u.buf.c_namesize > MC_MAXPATHLEN) {
 296         message (D_ERROR, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"),
 297                 super->name);
 298         return STATUS_FAIL;
 299     }
 300     name = g_malloc(u.buf.c_namesize);
 301     if((len = mc_read(super->u.arch.fd, name, u.buf.c_namesize)) < u.buf.c_namesize) {
 302         g_free(name);
 303         return STATUS_EOF;
 304     }
 305     name[u.buf.c_namesize - 1] = '\0';
 306     CPIO_POS(super) += len;
 307     cpio_skip_padding(super);
 308
 309     if(!strcmp("TRAILER!!!", name)) { /* We got to the last record */
 310         g_free(name);
 311         return STATUS_TRAIL;
 312     }
 313
 314     st.st_dev = u.buf.c_dev;
 315     st.st_ino = u.buf.c_ino;
 316     st.st_mode = u.buf.c_mode;
 317     st.st_nlink = u.buf.c_nlink;
 318     st.st_uid = u.buf.c_uid;
 319     st.st_gid = u.buf.c_gid;
 320     st.st_rdev = u.buf.c_rdev;
 321     st.st_size = (u.buf.c_filesizes[0] << 16) | u.buf.c_filesizes[1];
 322     st.st_atime = st.st_mtime = st.st_ctime = (u.buf.c_mtimes[0] << 16) | u.buf.c_mtimes[1];
 323
 324     return cpio_create_entry(me, super, &st, name);
 325 }
 326 #undef HEAD_LENGTH
 327
 328 #define HEAD_LENGTH (76)
 329 static ssize_t cpio_read_oldc_head(struct vfs_class *me, struct vfs_s_super *super)
 330 {
 331     struct new_cpio_header hd;
 332     union {
 333         struct stat st;
 334         char buf[HEAD_LENGTH + 1];
 335     } u;
 336     int len;
 337     char *name;
 338
 339     if (mc_read (super->u.arch.fd, u.buf, HEAD_LENGTH) != HEAD_LENGTH)
 340         return STATUS_EOF;
 341     CPIO_POS (super) += HEAD_LENGTH;
 342     u.buf[HEAD_LENGTH] = 0;
 343
 344     if (sscanf (u.buf, "070707%6lo%6lo%6lo%6lo%6lo%6lo%6lo%11lo%6lo%11lo",
 345               (unsigned long *)&hd.c_dev, &hd.c_ino, &hd.c_mode, &hd.c_uid, &hd.c_gid,
 346               &hd.c_nlink, (unsigned long *)&hd.c_rdev, &hd.c_mtime,
 347               &hd.c_namesize, &hd.c_filesize) < 10) {
 348         message (D_ERROR, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"),
 349                     super->name);
 350         return STATUS_FAIL;
 351     }
 352
 353     if (hd.c_namesize == 0 || hd.c_namesize > MC_MAXPATHLEN) {
 354         message (D_ERROR, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"),
 355                     super->name);
 356         return STATUS_FAIL;
 357     }
 358     name = g_malloc(hd.c_namesize);
 359     if((len = mc_read(super->u.arch.fd, name, hd.c_namesize)) == -1 ||
 360        (unsigned long) len < hd.c_namesize) {
 361         g_free (name);
 362         return STATUS_EOF;
 363     }
 364     name[hd.c_namesize - 1] = '\0';
 365     CPIO_POS(super) +=  len;
 366     cpio_skip_padding(super);
 367
 368     if(!strcmp("TRAILER!!!", name)) { /* We got to the last record */
 369         g_free(name);
 370         return STATUS_TRAIL;
 371     }
 372
 373     u.st.st_dev = hd.c_dev;
 374     u.st.st_ino = hd.c_ino;
 375     u.st.st_mode = hd.c_mode;
 376     u.st.st_nlink = hd.c_nlink;
 377     u.st.st_uid = hd.c_uid;
 378     u.st.st_gid = hd.c_gid;
 379     u.st.st_rdev = hd.c_rdev;
 380     u.st.st_size = hd.c_filesize;
 381     u.st.st_atime = u.st.st_mtime = u.st.st_ctime = hd.c_mtime;
 382
 383     return cpio_create_entry (me, super, &u.st, name);
 384 }
 385 #undef HEAD_LENGTH
 386
 387 #define HEAD_LENGTH (110)
 388 static ssize_t cpio_read_crc_head(struct vfs_class *me, struct vfs_s_super *super)
 389 {
 390     struct new_cpio_header hd;
 391     union {
 392         struct stat st;
 393         char buf[HEAD_LENGTH + 1];
 394     } u;
 395     int len;
 396     char *name;
 397
 398     if (mc_read (super->u.arch.fd, u.buf, HEAD_LENGTH) != HEAD_LENGTH)
 399         return STATUS_EOF;
 400     CPIO_POS (super) += HEAD_LENGTH;
 401     u.buf[HEAD_LENGTH] = 0;
 402
 403     if (sscanf (u.buf, "%6ho%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx",
 404               &hd.c_magic, &hd.c_ino, &hd.c_mode, &hd.c_uid, &hd.c_gid,
 405               &hd.c_nlink,  &hd.c_mtime, &hd.c_filesize,
 406               (unsigned long *)&hd.c_dev, (unsigned long *)&hd.c_devmin, (unsigned long *)&hd.c_rdev, (unsigned long *)&hd.c_rdevmin,
 407               &hd.c_namesize, &hd.c_chksum) < 14) {
 408         message (D_ERROR, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"),
 409                    super->name);
 410         return STATUS_FAIL;
 411     }
 412
 413     if((super->u.arch.type == CPIO_NEWC && hd.c_magic != 070701) ||
 414        (super->u.arch.type == CPIO_CRC && hd.c_magic != 070702))
 415         return STATUS_FAIL;
 416
 417     if (hd.c_namesize == 0 || hd.c_namesize > MC_MAXPATHLEN) {
 418         message (D_ERROR, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"),
 419                     super->name);
 420         return STATUS_FAIL;
 421     }
 422
 423     name = g_malloc(hd.c_namesize);
 424     if((len = mc_read (super->u.arch.fd, name, hd.c_namesize)) == -1 ||
 425        (unsigned long) len < hd.c_namesize) {
 426         g_free (name);
 427         return STATUS_EOF;
 428     }
 429     name[hd.c_namesize - 1] = '\0';
 430     CPIO_POS(super) += len;
 431     cpio_skip_padding(super);
 432
 433     if(!strcmp("TRAILER!!!", name)) { /* We got to the last record */
 434         g_free(name);
 435         return STATUS_TRAIL;
 436     }
 437
 438     u.st.st_dev = makedev (hd.c_dev, hd.c_devmin);
 439     u.st.st_ino = hd.c_ino;
 440     u.st.st_mode = hd.c_mode;
 441     u.st.st_nlink = hd.c_nlink;
 442     u.st.st_uid = hd.c_uid;
 443     u.st.st_gid = hd.c_gid;
 444     u.st.st_rdev = makedev (hd.c_rdev, hd.c_rdevmin);
 445     u.st.st_size = hd.c_filesize;
 446     u.st.st_atime = u.st.st_mtime = u.st.st_ctime = hd.c_mtime;
 447
 448     return cpio_create_entry (me, super, &u.st, name);
 449 }
 450
 451 static int
 452 cpio_create_entry (struct vfs_class *me, struct vfs_s_super *super,
 453                    struct stat *st, char *name)
 454 {
 455     struct vfs_s_inode *inode = NULL;
 456     struct vfs_s_inode *root = super->root;
 457     struct vfs_s_entry *entry = NULL;
 458     char *tn;
 459
 460     switch (st->st_mode & S_IFMT) {     /* For case of HP/UX archives */
 461     case S_IFCHR:
 462     case S_IFBLK:
 463 #ifdef S_IFSOCK
 464     case S_IFSOCK:
 465 #endif
 466 #ifdef S_IFIFO
 467     case S_IFIFO:
 468 #endif
 469 #ifdef S_IFNAM
 470     case S_IFNAM:
 471 #endif
 472         if ((st->st_size != 0) && (st->st_rdev == 0x0001)) {
 473             /* FIXME: representation of major/minor differs between */
 474             /* different operating systems. */
 475             st->st_rdev = (unsigned) st->st_size;
 476             st->st_size = 0;
 477         }
 478         break;
 479     default:
 480         break;
 481     }
 482
 483     if ((st->st_nlink > 1) && (super->u.arch.type == CPIO_NEWC || super->u.arch.type == CPIO_CRC)) {    /* For case of hardlinked files */
 484         struct defer_inode i, *l;
 485         i.inumber = st->st_ino;
 486         i.device = st->st_dev;
 487         i.inode = NULL;
 488         if ((l = cpio_defer_find (super->u.arch.deferred, &i)) != NULL) {
 489             inode = l->inode;
 490             if (inode->st.st_size && st->st_size
 491                 && (inode->st.st_size != st->st_size)) {
 492                 message (D_ERROR, MSG_ERROR,
 493                          _
 494                          ("Inconsistent hardlinks of\n%s\nin cpio archive\n%s"),
 495                          name, super->name);
 496                 inode = NULL;
 497             } else if (!inode->st.st_size)
 498                 inode->st.st_size = st->st_size;
 499         }
 500     }
 501
 502     for (tn = name + strlen (name) - 1; tn >= name && *tn == PATH_SEP; tn--)
 503         *tn = 0;
 504     if ((tn = strrchr (name, PATH_SEP))) {
 505         *tn = 0;
 506         root = vfs_s_find_inode (me, super, name, LINK_FOLLOW, FL_MKDIR);
 507         *tn = PATH_SEP;
 508         tn++;
 509     } else
 510         tn = name;
 511
 512     entry = MEDATA->find_entry (me, root, tn, LINK_FOLLOW, FL_NONE);    /* In case entry is already there */
 513
 514     if (entry) {                /* This shouldn't happen! (well, it can happen if there is a record for a
 515                                    file and than a record for a directory it is in; cpio would die with
 516                                    'No such file or directory' is such case) */
 517
 518         if (!S_ISDIR (entry->ino->st.st_mode)) {        /* This can be considered archive inconsistency */
 519             message (D_ERROR, MSG_ERROR,
 520                      _("%s contains duplicate entries! Skipping!"),
 521                      super->name);
 522         } else {
 523             entry->ino->st.st_mode = st->st_mode;
 524             entry->ino->st.st_uid = st->st_uid;
 525             entry->ino->st.st_gid = st->st_gid;
 526             entry->ino->st.st_atime = st->st_atime;
 527             entry->ino->st.st_mtime = st->st_mtime;
 528             entry->ino->st.st_ctime = st->st_ctime;
 529         }
 530
 531     } else {                    /* !entry */
 532
 533         if (!inode) {
 534             inode = vfs_s_new_inode (me, super, st);
 535             if ((st->st_nlink > 0) && (super->u.arch.type == CPIO_NEWC || super->u.arch.type == CPIO_CRC)) {    /* For case of hardlinked files */
 536                 struct defer_inode *i;
 537                 i = g_new (struct defer_inode, 1);
 538                 i->inumber = st->st_ino;
 539                 i->device = st->st_dev;
 540                 i->inode = inode;
 541                 i->next = super->u.arch.deferred;
 542                 super->u.arch.deferred = i;
 543             }
 544         }
 545
 546         if (st->st_size)
 547             inode->data_offset = CPIO_POS (super);
 548
 549         entry = vfs_s_new_entry (me, tn, inode);
 550         vfs_s_insert_entry (me, root, entry);
 551
 552         if (S_ISLNK (st->st_mode)) {
 553             inode->linkname = g_malloc (st->st_size + 1);
 554             if (mc_read (super->u.arch.fd, inode->linkname, st->st_size)
 555                 < st->st_size) {
 556                 inode->linkname[0] = 0;
 557                 g_free (name);
 558                 return STATUS_EOF;
 559             }
 560             inode->linkname[st->st_size] = 0;   /* Linkname stored without terminating \0 !!! */
 561             CPIO_POS (super) += st->st_size;
 562             cpio_skip_padding (super);
 563         } else {
 564             CPIO_SEEK_CUR (super, st->st_size);
 565         }
 566
 567     }                           /* !entry */
 568
 569     g_free (name);
 570     return STATUS_OK;
 571 }
 572
 573 /* Need to CPIO_SEEK_CUR to skip the file at the end of add entry!!!! */
 574
 575 static int
 576 cpio_open_archive (struct vfs_class *me, struct vfs_s_super *super,
 577                    const char *name, char *op)
 578 {
 579     int status = STATUS_START;
 580
 581     (void) op;
 582
 583     if (cpio_open_cpio_file (me, super, name) == -1)
 584         return -1;
 585
 586     for (;;) {
 587         status = cpio_read_head (me, super);
 588
 589         switch (status) {
 590         case STATUS_EOF:
 591             message (D_ERROR, MSG_ERROR, _("Unexpected end of file\n%s"), name);
 592             return 0;
 593         case STATUS_OK:
 594             continue;
 595         case STATUS_TRAIL:
 596             break;
 597         }
 598         break;
 599     }
 600
 601     return 0;
 602 }
 603
 604 /* Remaining functions are exactly same as for tarfs (and were in fact just copied) */
 605 static void *
 606 cpio_super_check (struct vfs_class *me, const char *archive_name, char *op)
 607 {
 608     static struct stat sb;
 609
 610     (void) me;
 611     (void) op;
 612
 613     if (mc_stat (archive_name, &sb))
 614         return NULL;
 615     return &sb;
 616 }
 617
 618 static int
 619 cpio_super_same (struct vfs_class *me, struct vfs_s_super *parc,
 620                  const char *archive_name, char *op, void *cookie)
 621 {
 622     struct stat *archive_stat = cookie; /* stat of main archive */
 623
 624     (void) me;
 625     (void) op;
 626
 627     if (strcmp (parc->name, archive_name))
 628         return 0;
 629
 630     /* Has the cached archive been changed on the disk? */
 631     if (parc->u.arch.st.st_mtime < archive_stat->st_mtime) {
 632         /* Yes, reload! */
 633         (*vfs_cpiofs_ops.free) ((vfsid) parc);
 634         vfs_rmstamp (&vfs_cpiofs_ops, (vfsid) parc);
 635         return 2;
 636     }
 637     /* Hasn't been modified, give it a new timeout */
 638     vfs_stamp (&vfs_cpiofs_ops, (vfsid) parc);
 639     return 1;
 640 }
 641
 642 static ssize_t cpio_read(void *fh, char *buffer, int count)
 643 {
 644     off_t begin = FH->ino->data_offset;
 645     int fd = FH_SUPER->u.arch.fd;
 646     struct vfs_class *me = FH_SUPER->me;
 647
 648     if (mc_lseek (fd, begin + FH->pos, SEEK_SET) !=
 649         begin + FH->pos) ERRNOR (EIO, -1);
 650
 651     count = MIN(count, FH->ino->st.st_size - FH->pos);
 652
 653     if ((count = mc_read (fd, buffer, count)) == -1) ERRNOR (errno, -1);
 654
 655     FH->pos += count;
 656     return count;
 657 }
 658
 659 static int cpio_fh_open(struct vfs_class *me, struct vfs_s_fh *fh, int flags, int mode)
 660 {
 661     (void) fh;
 662     (void) mode;
 663
 664     if ((flags & O_ACCMODE) != O_RDONLY) ERRNOR (EROFS, -1);
 665     return 0;
 666 }
 667
 668 void
 669 init_cpiofs (void)
 670 {
 671     static struct vfs_s_subclass cpio_subclass;
 672
 673     cpio_subclass.flags = VFS_S_READONLY;
 674     cpio_subclass.archive_check = cpio_super_check;
 675     cpio_subclass.archive_same = cpio_super_same;
 676     cpio_subclass.open_archive = cpio_open_archive;
 677     cpio_subclass.free_archive = cpio_free_archive;
 678     cpio_subclass.fh_open = cpio_fh_open;
 679
 680     vfs_s_init_class (&vfs_cpiofs_ops, &cpio_subclass);
 681     vfs_cpiofs_ops.name = "cpiofs";
 682     vfs_cpiofs_ops.prefix = "ucpio";
 683     vfs_cpiofs_ops.read = cpio_read;
 684     vfs_cpiofs_ops.setctl = NULL;
 685     vfs_register_class (&vfs_cpiofs_ops);
 686 }