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 <linux/ext2_fs.h>
  28
  29 #include "ext2fs.h"
  30
  31 struct get_pathname_struct {
  32         ino_t           search_ino;
  33         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,
  43                              int        blocksize,
  44                              char       *buf,
  45                              void       *private)
  46 {
  47         struct get_pathname_struct      *gp;
  48         errcode_t                       retval;
  49
  50         gp = (struct get_pathname_struct *) private;
  51
  52         if ((dirent->name_len == 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 + 1,
  57                                         (void **) &gp->name);
  58                 if (!gp->name) {
  59                         gp->errcode = EXT2_ET_NO_MEMORY;
  60                         return DIRENT_ABORT;
  61                 }
  62                 strncpy(gp->name, dirent->name, dirent->name_len);
  63                 gp->name[dirent->name_len] = '\0';
  64                 return DIRENT_ABORT;
  65         }
  66         return 0;
  67 }
  68
  69 static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ino_t dir, ino_t ino,
  70                                          int maxdepth, 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, (void **)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, (void **)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                                         (void **) &ret);
 117         else
 118                 retval = ext2fs_get_mem(strlen(parent_name)+5,
 119                                         (void **) &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((void **) &parent_name);
 133         retval = 0;
 134
 135 cleanup:
 136         if (gp.name)
 137                 ext2fs_free_mem((void **) &gp.name);
 138         return retval;
 139 }
 140
 141 errcode_t ext2fs_get_pathname(ext2_filsys fs, ino_t dir, ino_t ino,
 142                               char **name)
 143 {
 144         char    *buf;
 145         errcode_t       retval;
 146
 147         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 148
 149         retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
 150         if (retval)
 151                 return retval;
 152         if (dir == ino)
 153                 ino = 0;
 154         retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
 155         ext2fs_free_mem((void **) &buf);
 156         return retval;
 157
 158 }