release/src/router/busybox/e2fsprogs/ext2fs/get_pathname.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * get_pathname.c --- do directry/inode -> name translation
   4  *
   5  * Copyright (C) 1993, 1994, 1995 Theodore Ts'o.
   6  *
   7  * %Begin-Header%
   8  * This file may be redistributed under the terms of the GNU Public
   9  * License.
  10  * %End-Header%
  11  *
  12  *      ext2fs_get_pathname(fs, dir, ino, name)
  13  *
  14  *      This function translates takes two inode numbers into a
  15  *      string, placing the result in <name>.  <dir> is the containing
  16  *      directory inode, and <ino> is the inode number itself.  If
  17  *      <ino> is zero, then ext2fs_get_pathname will return pathname
  18  *      of the directory <dir>.
  19  *
  20  */
  21
  22 #include <stdio.h>
  23 #include <string.h>
  24 #if HAVE_UNISTD_H
  25 #include <unistd.h>
  26 #endif
  27
  28 #include "ext2_fs.h"
  29 #include "ext2fs.h"
  30
  31 struct get_pathname_struct {
  32         ext2_ino_t      search_ino;
  33         ext2_ino_t      parent;
  34         char            *name;
  35         errcode_t       errcode;
  36 };
  37
  38 #ifdef __TURBOC__
  39 # pragma argsused
  40 #endif
  41 static int get_pathname_proc(struct ext2_dir_entry *dirent,
  42                              int        offset EXT2FS_ATTR((unused)),
  43                              int        blocksize EXT2FS_ATTR((unused)),
  44                              char       *buf EXT2FS_ATTR((unused)),
  45                              void       *priv_data)
  46 {
  47         struct get_pathname_struct      *gp;
  48         errcode_t                       retval;
  49
  50         gp = (struct get_pathname_struct *) priv_data;
  51
  52         if (((dirent->name_len & 0xFF) == 2) &&
  53             !strncmp(dirent->name, "..", 2))
  54                 gp->parent = dirent->inode;
  55         if (dirent->inode == gp->search_ino) {
  56                 retval = ext2fs_get_mem((dirent->name_len & 0xFF) + 1,
  57                                         &gp->name);
  58                 if (retval) {
  59                         gp->errcode = retval;
  60                         return DIRENT_ABORT;
  61                 }
  62                 strncpy(gp->name, dirent->name, (dirent->name_len & 0xFF));
  63                 gp->name[dirent->name_len & 0xFF] = '\0';
  64                 return DIRENT_ABORT;
  65         }
  66         return 0;
  67 }
  68
  69 static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ext2_ino_t dir,
  70                                          ext2_ino_t ino, int maxdepth,
  71                                          char *buf, char **name)
  72 {
  73         struct get_pathname_struct gp;
  74         char    *parent_name, *ret;
  75         errcode_t       retval;
  76
  77         if (dir == ino) {
  78                 retval = ext2fs_get_mem(2, name);
  79                 if (retval)
  80                         return retval;
  81                 strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
  82                 return 0;
  83         }
  84
  85         if (!dir || (maxdepth < 0)) {
  86                 retval = ext2fs_get_mem(4, name);
  87                 if (retval)
  88                         return retval;
  89                 strcpy(*name, "...");
  90                 return 0;
  91         }
  92
  93         gp.search_ino = ino;
  94         gp.parent = 0;
  95         gp.name = 0;
  96         gp.errcode = 0;
  97
  98         retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
  99         if (retval)
 100                 goto cleanup;
 101         if (gp.errcode) {
 102                 retval = gp.errcode;
 103                 goto cleanup;
 104         }
 105
 106         retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
 107                                          buf, &parent_name);
 108         if (retval)
 109                 goto cleanup;
 110         if (!ino) {
 111                 *name = parent_name;
 112                 return 0;
 113         }
 114
 115         if (gp.name)
 116                 retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
 117                                         &ret);
 118         else
 119                 retval = ext2fs_get_mem(strlen(parent_name)+5, &ret);
 120         if (retval)
 121                 goto cleanup;
 122
 123         ret[0] = 0;
 124         if (parent_name[1])
 125                 strcat(ret, parent_name);
 126         strcat(ret, "/");
 127         if (gp.name)
 128                 strcat(ret, gp.name);
 129         else
 130                 strcat(ret, "???");
 131         *name = ret;
 132         ext2fs_free_mem(&parent_name);
 133         retval = 0;
 134
 135 cleanup:
 136         ext2fs_free_mem(&gp.name);
 137         return retval;
 138 }
 139
 140 errcode_t ext2fs_get_pathname(ext2_filsys fs, ext2_ino_t dir, ext2_ino_t ino,
 141                               char **name)
 142 {
 143         char    *buf;
 144         errcode_t       retval;
 145
 146         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 147
 148         retval = ext2fs_get_mem(fs->blocksize, &buf);
 149         if (retval)
 150                 return retval;
 151         if (dir == ino)
 152                 ino = 0;
 153         retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
 154         ext2fs_free_mem(&buf);
 155         return retval;
 156 }