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fsck.cramfs.c

/*
 * cramfsck - check a cramfs file system
 *
 * Copyright (C) 2000-2001 Transmeta Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * 1999/12/03: Linus Torvalds (cramfs tester and unarchive program)
 * 2000/06/03: Daniel Quinlan (CRC and length checking program)
 * 2000/06/04: Daniel Quinlan (merged programs, added options, support
 *                            for special files, preserve permissions and
 *                            ownership, cramfs superblock v2, bogus mode
 *                            test, pathname length test, etc.)
 * 2000/06/06: Daniel Quinlan (support for holes, pretty-printing,
 *                            symlink size test)
 * 2000/07/11: Daniel Quinlan (file length tests, start at offset 0 or 512,
 *                            fsck-compatible exit codes)
 * 2000/07/15: Daniel Quinlan (initial support for block devices)
 */

/* compile-time options */
#define INCLUDE_FS_TESTS      /* include cramfs checking and extraction */

#include <stdio.h>
#include <unistd.h>
#include <dirent.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <getopt.h>
#include <utime.h>
#include <fcntl.h>
#include <zlib.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/sysmacros.h>    /* for major, minor */

#include "cramfs.h"
#include "../defines.h"       /* for HAVE_lchown */
#include "nls.h"

#define BLKGETSIZE _IO(0x12,96) /* return device size */

static const char *progname = "cramfsck";

static int fd;                /* ROM image file descriptor */
static char *filename;        /* ROM image filename */
struct cramfs_super *super;   /* just find the cramfs superblock once */
static int opt_verbose = 0;   /* 1 = verbose (-v), 2+ = very verbose (-vv) */

#ifdef INCLUDE_FS_TESTS
static int opt_extract = 0;   /* extract cramfs (-x) */
char *extract_dir = NULL;     /* extraction directory (-x) */

unsigned long start_inode = 1 << 28;      /* start of first non-root inode */
unsigned long end_inode = 0;        /* end of the directory structure */
unsigned long start_data = 1 << 28; /* start of the data (256 MB = max) */
unsigned long end_data = 0;         /* end of the data */
/* true?  cramfs_super < start_inode < end_inode <= start_data <= end_data */
static uid_t euid;                  /* effective UID */

#define PAD_SIZE 512

#include <asm/page.h>
#ifdef PAGE_SIZE
#define PAGE_CACHE_SIZE ((int) PAGE_SIZE)
#elif defined __ia64__
#define PAGE_CACHE_SIZE (16384)
#elif defined __alpha__
#define PAGE_CACHE_SIZE (8192)
#else
#define PAGE_CACHE_SIZE (4096)
#endif

/* Guarantee access to at least 8kB at a time */
#define ROMBUFFER_BITS  13
#define ROMBUFFERSIZE   (1 << ROMBUFFER_BITS)
#define ROMBUFFERMASK   (ROMBUFFERSIZE-1)
static char read_buffer[ROMBUFFERSIZE * 2];
static unsigned long read_buffer_block = ~0UL;

/* Uncompressing data structures... */
static char outbuffer[PAGE_CACHE_SIZE*2];
z_stream stream;

#endif /* INCLUDE_FS_TESTS */

/* Input status of 0 to print help and exit without an error. */
static void usage(int status)
{
      FILE *stream = status ? stderr : stdout;

      fprintf(stream, _("usage: %s [-hv] [-x dir] file\n"
            " -h         print this help\n"
            " -x dir     extract into dir\n"
            " -v         be more verbose\n"
            " file       file to test\n"), progname);

      exit(status);
}

#ifdef INCLUDE_FS_TESTS
static void print_node(char type, struct cramfs_inode *i, char *name)
{
      char info[10];

      if (S_ISCHR(i->mode) || (S_ISBLK(i->mode))) {
            /* major/minor numbers can be as high as 2^12 or 4096 */
            snprintf(info, 10, "%4d,%4d", major(i->size), minor(i->size));
      }
      else {
            /* size be as high as 2^24 or 16777216 */
            snprintf(info, 10, "%9d", i->size);
      }

      printf("%c %04o %s %5d:%-3d %s\n",
             type, i->mode & ~S_IFMT, info, i->uid, i->gid, name);
}

/*
 * Create a fake "blocked" access
 */
static void *romfs_read(unsigned long offset)
{
      unsigned int block = offset >> ROMBUFFER_BITS;
      if (block != read_buffer_block) {
            read_buffer_block = block;
            lseek(fd, block << ROMBUFFER_BITS, SEEK_SET);
            read(fd, read_buffer, ROMBUFFERSIZE * 2);
      }
      return read_buffer + (offset & ROMBUFFERMASK);
}

static struct cramfs_inode *cramfs_iget(struct cramfs_inode * i)
{
      struct cramfs_inode *inode = malloc(sizeof(struct cramfs_inode));
      *inode = *i;
      return inode;
}

static struct cramfs_inode *iget(unsigned int ino)
{
      return cramfs_iget(romfs_read(ino));
}

#if 0
static void iput(struct cramfs_inode *inode)
{
      free(inode);
}
#endif

/*
 * Return the offset of the root directory,
 * or 0 if none.
 */
static struct cramfs_inode *read_super(void)
{
      unsigned long offset;

      offset = super->root.offset << 2;
      if (super->magic != CRAMFS_MAGIC)
            return NULL;
      if (memcmp(super->signature, CRAMFS_SIGNATURE, sizeof(super->signature)) != 0)
            return NULL;
      if (offset < sizeof(super))
            return NULL;
      return cramfs_iget(&super->root);
}

static int uncompress_block(void *src, int len)
{
      int err;

      stream.next_in = src;
      stream.avail_in = len;

      stream.next_out = (unsigned char *) outbuffer;
      stream.avail_out = PAGE_CACHE_SIZE*2;

      inflateReset(&stream);

      err = inflate(&stream, Z_FINISH);
      if (err != Z_STREAM_END) {
            fprintf(stderr,
                  _("%s: error %d while decompressing! %p(%d)\n"),
                  filename, err, src, len);
            exit(4);
      }
      return stream.total_out;
}

#ifdef HAVE_lchown
#define my_lchown lchown
#else
#define my_lchown chown
#endif

static void change_file_status(char *path, struct cramfs_inode *i)
{
      struct utimbuf epoch = { 0, 0 };

      if (euid == 0) {
            if (my_lchown(path, i->uid, i->gid) < 0) {
                  perror(path);
                  exit(8);
            }
            if (S_ISLNK(i->mode))
                  return;
            if ((S_ISUID | S_ISGID) & i->mode) {
                  if (chmod(path, i->mode) < 0) {
                        perror(path);
                        exit(8);
                  }
            }
      }
      if (S_ISLNK(i->mode))
            return;
      if (utime(path, &epoch) < 0) {
            perror(path);
            exit(8);
      }
}

static void do_symlink(char *path, struct cramfs_inode *i)
{
      unsigned long offset = i->offset << 2;
      unsigned long curr = offset + 4;
      unsigned long next = *(u32 *) romfs_read(offset);
      unsigned long size;

      if (next > end_data) {
            end_data = next;
      }

      size = uncompress_block(romfs_read(curr), next - curr);
      if (size != i->size) {
            fprintf(stderr, _("%s: size error in symlink `%s'\n"),
                  filename, path);
            exit(4);
      }
      outbuffer[size] = 0;
      if (opt_verbose) {
            char *str;

            str = malloc(strlen(outbuffer) + strlen(path) + 5);
            strcpy(str, path);
            strncat(str, " -> ", 4);
            strncat(str, outbuffer, size);

            print_node('l', i, str);
            if (opt_verbose > 1) {
                  printf(_("  uncompressing block at %ld "
                         "to %ld (%ld)\n"),
                         curr, next, next - curr);
            }
      }
      if (opt_extract) {
            symlink(outbuffer, path);
            change_file_status(path, i);
      }
}

static void do_special_inode(char *path, struct cramfs_inode *i)
{
      dev_t devtype = 0;
      char type;

      if (S_ISCHR(i->mode)) {
            devtype = i->size;
            type = 'c';
      }
      else if (S_ISBLK(i->mode)) {
            devtype = i->size;
            type = 'b';
      }
      else if (S_ISFIFO(i->mode))
            type = 'p';
      else if (S_ISSOCK(i->mode))
            type = 's';
      else {
            fprintf(stderr, _("%s: bogus mode on `%s' (%o)\n"),
                  filename, path, i->mode);
            exit(4);
      }

      if (opt_verbose) {
            print_node(type, i, path);
      }

      if (opt_extract) {
            if (mknod(path, i->mode, devtype) < 0) {
                  perror(path);
                  exit(8);
            }
            change_file_status(path, i);
      }
}

static void do_uncompress(int fd, unsigned long offset, unsigned long size)
{
      unsigned long curr = offset + 4 * ((size + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE);

      do {
            unsigned long out = PAGE_CACHE_SIZE;
            unsigned long next = *(u32 *) romfs_read(offset);

            if (next > end_data)
                  end_data = next;

            offset += 4;
            if (curr == next) {
                  if (opt_verbose > 1) {
                        printf(_("  hole at %ld (%d)\n"),
                               curr, PAGE_CACHE_SIZE);
                  }
                  if (size < PAGE_CACHE_SIZE)
                        out = size;
                  memset(outbuffer, 0x00, out);
            }
            else {
                  if (opt_verbose > 1) {
                        printf(_("  uncompressing block at %ld "
                               "to %ld (%ld)\n"),
                               curr, next, next - curr);
                  }
                  out = uncompress_block(romfs_read(curr), next - curr);
            }
            if (size >= PAGE_CACHE_SIZE) {
                  if (out != PAGE_CACHE_SIZE) {
                        fprintf(stderr,
                              _("%s: Non-block (%ld) bytes\n"),
                              filename, out);
                        exit(4);
                  }
            } else {
                  if (out != size) {
                        fprintf(stderr, _("%s: Non-size (%ld vs %ld) "
                                      "bytes\n"),
                              filename, out, size);
                        exit(4);
                  }
            }
            size -= out;
            if (opt_extract) {
                  write(fd, outbuffer, out);
            }
            curr = next;
      } while (size);
}

static void expand_fs(int pathlen, char *path, struct cramfs_inode *inode)
{
      if (S_ISDIR(inode->mode)) {
            int count = inode->size;
            unsigned long offset = inode->offset << 2;
            char *newpath = malloc(pathlen + 256);

            if (count > 0 && offset < start_inode) {
                  start_inode = offset;
            }
            /* XXX - need to check end_inode for empty case? */
            memcpy(newpath, path, pathlen);
            newpath[pathlen] = '/';
            pathlen++;
            if (opt_verbose) {
                  print_node('d', inode, path);
            }
            if (opt_extract) {
                  mkdir(path, inode->mode);
                  change_file_status(path, inode);
            }
            while (count > 0) {
                  struct cramfs_inode *child = iget(offset);
                  int size;
                  int newlen = child->namelen << 2;

                  size = sizeof(struct cramfs_inode) + newlen;
                  count -= size;

                  offset += sizeof(struct cramfs_inode);

                  memcpy(newpath + pathlen, romfs_read(offset), newlen);
                  newpath[pathlen + newlen] = 0;
                  if ((pathlen + newlen) - strlen(newpath) > 3) {
                        fprintf(stderr,
                              _("%s: invalid cramfs--bad "
                                "path length\n"),
                              filename);
                        exit(4);
                  }
                  expand_fs(strlen(newpath), newpath, child);

                  offset += newlen;

                  if (offset > end_inode) {
                        end_inode = offset;
                  }
            }
            return;
      }
      if (S_ISREG(inode->mode)) {
            int fd = 0;
            unsigned long offset = inode->offset << 2;

            if (offset > 0 && offset < start_data) {
                  start_data = offset;
            }
            if (opt_verbose) {
                  print_node('f', inode, path);
            }
            if (opt_extract) {
                  fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, inode->mode);
            }
            if (inode->size) {
                  do_uncompress(fd, offset, inode->size);
            }
            if (opt_extract) {
                  close(fd);
                  change_file_status(path, inode);
            }
            return;
      }
      if (S_ISLNK(inode->mode)) {
            unsigned long offset = inode->offset << 2;

            if (offset < start_data) {
                  start_data = offset;
            }
            do_symlink(path, inode);
            return;
      }
      else {
            do_special_inode(path, inode);
            return;
      }
}
#endif /* INCLUDE_FS_TESTS */

int main(int argc, char **argv)
{
      void *buf;
      size_t length;
      struct stat st;
      u32 crc_old, crc_new;
#ifdef INCLUDE_FS_TESTS
      struct cramfs_inode *root;
#endif /* INCLUDE_FS_TESTS */
      int c;                  /* for getopt */
      int start = 0;

      if (argc)
            progname = argv[0];

      /* command line options */
      while ((c = getopt(argc, argv, "hx:v")) != EOF) {
            switch (c) {
            case 'h':
                  usage(0);
            case 'x':
#ifdef INCLUDE_FS_TESTS
                  opt_extract = 1;
                  extract_dir = malloc(strlen(optarg) + 1);
                  strcpy(extract_dir, optarg);
                  break;
#else /*  not INCLUDE_FS_TESTS */
                  fprintf(stderr, _("%s: compiled without -x support\n"),
                        progname);
                  exit(16);
#endif /* not INCLUDE_FS_TESTS */
            case 'v':
                  opt_verbose++;
                  break;
            }
      }

      if ((argc - optind) != 1)
            usage(16);
      filename = argv[optind];

      /* find the physical size of the file or block device */
      if (lstat(filename, &st) < 0) {
            perror(filename);
            exit(8);
      }
      fd = open(filename, O_RDONLY);
      if (fd < 0) {
            perror(filename);
            exit(8);
      }
      if (S_ISBLK(st.st_mode)) {
            if (ioctl(fd, BLKGETSIZE, &length) < 0) {
                  fprintf(stderr, _("%s: warning--unable to determine "
                                "filesystem size \n"), filename);
                  exit(4);
            }
            length = length * 512;
      }
      else if (S_ISREG(st.st_mode)) {
            length = st.st_size;
      }
      else {
            fprintf(stderr, _("%s is not a block device or file\n"),
                  filename);
            exit(8);
      }

      if (length < sizeof(struct cramfs_super)) {
            fprintf(stderr, _("%s: invalid cramfs--file length "
                          "too short\n"), filename);
            exit(4);
      }

      if (S_ISBLK(st.st_mode)) {
            /* nasty because mmap of block devices fails */
            buf = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
            read(fd, buf, length);
      }
      else {
            /* nice and easy */
            buf = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
      }

      /* XXX - this could be cleaner... */
      if (((struct cramfs_super *) buf)->magic == CRAMFS_MAGIC) {
            start = 0;
            super = (struct cramfs_super *) buf;
      }
      else if (length >= (PAD_SIZE + sizeof(struct cramfs_super)) &&
             ((((struct cramfs_super *) (buf + PAD_SIZE))->magic == CRAMFS_MAGIC)))
      {
            start = PAD_SIZE;
            super = (struct cramfs_super *) (buf + PAD_SIZE);
      }
      else {
            fprintf(stderr, _("%s: invalid cramfs--wrong magic\n"),
                  filename);
            exit(4);
      }

      if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) {
            /* length test */
            if (length < super->size) {
                  fprintf(stderr, _("%s: invalid cramfs--file length "
                                "too short\n"), filename);
                  exit(4);
            }
            else if (length > super->size) {
                  fprintf(stderr, _("%s: warning--file length too long, "
                                "padded image?\n"), filename);
            }

            /* CRC test */
            crc_old = super->fsid.crc;
            super->fsid.crc = crc32(0L, Z_NULL, 0);
            crc_new = crc32(0L, Z_NULL, 0);
            crc_new = crc32(crc_new, (unsigned char *) buf+start, super->size - start);
            if (crc_new != crc_old) {
                  fprintf(stderr, _("%s: invalid cramfs--crc error\n"),
                        filename);
                  exit(4);
            }
      }
      else {
            fprintf(stderr, _("%s: warning--old cramfs image, no CRC\n"),
                  filename);
      }

#ifdef INCLUDE_FS_TESTS
      super = (struct cramfs_super *) malloc(sizeof(struct cramfs_super));
      if (((struct cramfs_super *) buf)->magic == CRAMFS_MAGIC) {
            memcpy(super, buf, sizeof(struct cramfs_super));
      }
      else if (length >= (PAD_SIZE + sizeof(struct cramfs_super)) &&
             ((((struct cramfs_super *) (buf + PAD_SIZE))->magic == CRAMFS_MAGIC)))
      {
            memcpy(super, (buf + PAD_SIZE), sizeof(struct cramfs_super));
      }

      munmap(buf, length);

      /* file format test, uses fake "blocked" accesses */
      root = read_super();
      umask(0);
      euid = geteuid();
      if (!root) {
            fprintf(stderr, _("%s: invalid cramfs--bad superblock\n"),
                  filename);
            exit(4);
      }
      stream.next_in = NULL;
      stream.avail_in = 0;
      inflateInit(&stream);

      if (!extract_dir)
            extract_dir = "root";

      expand_fs(strlen(extract_dir), extract_dir, root);
      inflateEnd(&stream);

      if (start_data != 1 << 28  && end_inode != start_data) {
            fprintf(stderr,
                  _("%s: invalid cramfs--directory data end "
                    "(%ld) != file data start (%ld)\n"),
                  filename, end_inode, start_data);
            exit(4);
      }
      if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) {
            if (end_data > super->size) {
                  fprintf(stderr,
                        _("%s: invalid cramfs--invalid file "
                          "data offset\n"),
                        filename);
                  exit(4);
            }
      }
#endif /* INCLUDE_FS_TESTS */

      exit(0);
}

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