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 #include <stdlib.h>
  27
  28 #include <linux/ext2_fs.h>
  29
  30 #include "ext2fs.h"
  31
  32 struct get_pathname_struct {
  33         ino_t           search_ino;
  34         ino_t           parent;
  35         char            *name;
  36         errcode_t       errcode;
  37 };
  38
  39 #ifdef __TURBOC__
  40 #pragma argsused
  41 #endif
  42 static int get_pathname_proc(struct ext2_dir_entry *dirent,
  43                              int        offset,
  44                              int        blocksize,
  45                              char       *buf,
  46                              void       *private)
  47 {
  48         struct get_pathname_struct      *gp;
  49         errcode_t                       retval;
  50
  51         gp = (struct get_pathname_struct *) private;
  52
  53         if ((dirent->name_len == 2) &&
  54             !strncmp(dirent->name, "..", 2))
  55                 gp->parent = dirent->inode;
  56         if (dirent->inode == gp->search_ino) {
  57                 retval = ext2fs_get_mem(dirent->name_len + 1,
  58                                         (void **) &gp->name);
  59                 if (!gp->name) {
  60                         gp->errcode = EXT2_NO_MEMORY;
  61                         return DIRENT_ABORT;
  62                 }
  63                 strncpy(gp->name, dirent->name, dirent->name_len);
  64                 gp->name[dirent->name_len] = '\0';
  65                 return DIRENT_ABORT;
  66         }
  67         return 0;
  68 }
  69
  70 static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ino_t dir, ino_t ino,
  71                                          int maxdepth, 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, (void **)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, (void **)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                                         (void **) &ret);
 118         else
 119                 retval = ext2fs_get_mem(strlen(parent_name)+5,
 120                                         (void **) &ret);
 121         if (retval)
 122                 goto cleanup;
 123
 124         ret[0] = 0;
 125         if (parent_name[1])
 126                 strcat(ret, parent_name);
 127         strcat(ret, "/");
 128         if (gp.name)
 129                 strcat(ret, gp.name);
 130         else
 131                 strcat(ret, "???");
 132         *name = ret;
 133         ext2fs_free_mem((void **) &parent_name);
 134         retval = 0;
 135
 136 cleanup:
 137         if (gp.name)
 138                 ext2fs_free_mem((void **) &gp.name);
 139         return retval;
 140 }
 141
 142 errcode_t ext2fs_get_pathname(ext2_filsys fs, ino_t dir, ino_t ino,
 143                               char **name)
 144 {
 145         char    *buf;
 146         errcode_t       retval;
 147
 148         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 149
 150         retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
 151         if (retval)
 152                 return retval;
 153         if (dir == ino)
 154                 ino = 0;
 155         retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
 156         ext2fs_free_mem((void **) &buf);
 157         return retval;
 158
 159 }