lib/ext2fs/dir_iterate.c

   1 /*
   2  * dir_iterate.c --- ext2fs directory iteration operations
   3  *
   4  * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #if HAVE_ERRNO_H
  18 #include <errno.h>
  19 #endif
  20
  21 #if EXT2_FLAT_INCLUDES
  22 #include "ext2_fs.h"
  23 #else
  24 #include <linux/ext2_fs.h>
  25 #endif
  26
  27 #include "ext2fsP.h"
  28
  29 errcode_t ext2fs_dir_iterate(ext2_filsys fs,
  30                              ino_t dir,
  31                              int flags,
  32                              char *block_buf,
  33                              int (*func)(struct ext2_dir_entry *dirent,
  34                                          int    offset,
  35                                          int    blocksize,
  36                                          char   *buf,
  37                                          void   *priv_data),
  38                              void *priv_data)
  39 {
  40         struct          dir_context     ctx;
  41         errcode_t       retval;
  42
  43         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  44
  45         retval = ext2fs_check_directory(fs, dir);
  46         if (retval)
  47                 return retval;
  48
  49         ctx.dir = dir;
  50         ctx.flags = flags;
  51         if (block_buf)
  52                 ctx.buf = block_buf;
  53         else {
  54                 retval = ext2fs_get_mem(fs->blocksize, (void **) &ctx.buf);
  55                 if (retval)
  56                         return retval;
  57         }
  58         ctx.func = func;
  59         ctx.func2 = 0;
  60         ctx.priv_data = priv_data;
  61         ctx.errcode = 0;
  62         retval = ext2fs_block_iterate2(fs, dir, 0, 0,
  63                                        ext2fs_process_dir_block, &ctx);
  64         if (!block_buf)
  65                 ext2fs_free_mem((void **) &ctx.buf);
  66         if (retval)
  67                 return retval;
  68         return ctx.errcode;
  69 }
  70
  71 /*
  72  * Helper function which is private to this module.  Used by
  73  * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate()
  74  */
  75 extern int ext2fs_process_dir_block(ext2_filsys         fs,
  76                                     blk_t               *blocknr,
  77                                     e2_blkcnt_t         blockcnt,
  78                                     blk_t               ref_block,
  79                                     int                 ref_offset,
  80                                     void                *priv_data)
  81 {
  82         struct dir_context *ctx = (struct dir_context *) priv_data;
  83         int             offset = 0;
  84         int             ret = 0;
  85         int             changed = 0;
  86         int             do_abort = 0;
  87         int             entry;
  88         struct ext2_dir_entry *dirent;
  89
  90         if (blockcnt < 0)
  91                 return 0;
  92
  93         entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
  94
  95         ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);
  96         if (ctx->errcode)
  97                 return BLOCK_ABORT;
  98
  99         while (offset < fs->blocksize) {
 100                 dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
 101                 if (!dirent->inode &&
 102                     !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
 103                         goto next;
 104
 105                 if (ctx->func)
 106                         ret = (ctx->func)(dirent, offset, fs->blocksize,
 107                                           ctx->buf, ctx->priv_data);
 108                 else if (ctx->func2) {
 109                         ret = (ctx->func2)(ctx->dir, entry, dirent, offset,
 110                                            fs->blocksize, ctx->buf,
 111                                            ctx->priv_data);
 112                         if (entry < DIRENT_OTHER_FILE)
 113                                 entry++;
 114                 }
 115
 116                 if (ret & DIRENT_CHANGED)
 117                         changed++;
 118                 if (ret & DIRENT_ABORT) {
 119                         do_abort++;
 120                         break;
 121                 }
 122 next:
 123                 if (((offset + dirent->rec_len) > fs->blocksize) ||
 124                     (dirent->rec_len < 8) ||
 125                     (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {
 126                         ctx->errcode = EXT2_ET_DIR_CORRUPTED;
 127                         return BLOCK_ABORT;
 128                 }
 129                 offset += dirent->rec_len;
 130         }
 131
 132         if (changed) {
 133                 ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);
 134                 if (ctx->errcode)
 135                         return BLOCK_ABORT;
 136         }
 137         if (do_abort)
 138                 return BLOCK_ABORT;
 139         return 0;
 140 }
 141