lib/ext2fs/get_pathname.c

   1 /*
   2  * get_pathname.c --- do directry/inode -> name translation
   3  *
   4  * Copyright (C) 1993, 1994, 1995 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  *      ext2fs_get_pathname(fs, dir, ino, name)
  12  *
  13  *      This function translates takes two inode numbers into a
  14  *      string, placing the result in <name>.  <dir> is the containing
  15  *      directory inode, and <ino> is the inode number itself.  If
  16  *      <ino> is zero, then ext2fs_get_pathname will return pathname
  17  *      of the the directory <dir>.
  18  *
  19  */
  20
  21 #include <stdio.h>
  22 #include <string.h>
  23 #if HAVE_UNISTD_H
  24 #include <unistd.h>
  25 #endif
  26
  27 #include "ext2_fs.h"
  28 #include "ext2fs.h"
  29
  30 struct get_pathname_struct {
  31         ext2_ino_t      search_ino;
  32         ext2_ino_t      parent;
  33         char            *name;
  34         errcode_t       errcode;
  35 };
  36
  37 #ifdef __TURBOC__
  38  #pragma argsused
  39 #endif
  40 static int get_pathname_proc(struct ext2_dir_entry *dirent,
  41                              int        offset EXT2FS_ATTR((unused)),
  42                              int        blocksize EXT2FS_ATTR((unused)),
  43                              char       *buf EXT2FS_ATTR((unused)),
  44                              void       *priv_data)
  45 {
  46         struct get_pathname_struct      *gp;
  47         errcode_t                       retval;
  48
  49         gp = (struct get_pathname_struct *) priv_data;
  50
  51         if (((dirent->name_len & 0xFF) == 2) &&
  52             !strncmp(dirent->name, "..", 2))
  53                 gp->parent = dirent->inode;
  54         if (dirent->inode == gp->search_ino) {
  55                 retval = ext2fs_get_mem((dirent->name_len & 0xFF) + 1,
  56                                         &gp->name);
  57                 if (retval) {
  58                         gp->errcode = retval;
  59                         return DIRENT_ABORT;
  60                 }
  61                 strncpy(gp->name, dirent->name, (dirent->name_len & 0xFF));
  62                 gp->name[dirent->name_len & 0xFF] = '\0';
  63                 return DIRENT_ABORT;
  64         }
  65         return 0;
  66 }
  67
  68 static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ext2_ino_t dir,
  69                                          ext2_ino_t ino, int maxdepth,
  70                                          char *buf, char **name)
  71 {
  72         struct get_pathname_struct gp;
  73         char    *parent_name, *ret;
  74         errcode_t       retval;
  75
  76         if (dir == ino) {
  77                 retval = ext2fs_get_mem(2, name);
  78                 if (retval)
  79                         return retval;
  80                 strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
  81                 return 0;
  82         }
  83
  84         if (!dir || (maxdepth < 0)) {
  85                 retval = ext2fs_get_mem(4, name);
  86                 if (retval)
  87                         return retval;
  88                 strcpy(*name, "...");
  89                 return 0;
  90         }
  91
  92         gp.search_ino = ino;
  93         gp.parent = 0;
  94         gp.name = 0;
  95         gp.errcode = 0;
  96
  97         retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
  98         if (retval)
  99                 goto cleanup;
 100         if (gp.errcode) {
 101                 retval = gp.errcode;
 102                 goto cleanup;
 103         }
 104
 105         retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
 106                                          buf, &parent_name);
 107         if (retval)
 108                 goto cleanup;
 109         if (!ino) {
 110                 *name = parent_name;
 111                 return 0;
 112         }
 113
 114         if (gp.name)
 115                 retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
 116                                         &ret);
 117         else
 118                 retval = ext2fs_get_mem(strlen(parent_name)+5, &ret);
 119         if (retval)
 120                 goto cleanup;
 121
 122         ret[0] = 0;
 123         if (parent_name[1])
 124                 strcat(ret, parent_name);
 125         strcat(ret, "/");
 126         if (gp.name)
 127                 strcat(ret, gp.name);
 128         else
 129                 strcat(ret, "???");
 130         *name = ret;
 131         ext2fs_free_mem(&parent_name);
 132         retval = 0;
 133
 134 cleanup:
 135         if (gp.name)
 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
 157 }