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 #if EXT2_FLAT_INCLUDES
  28 #include "ext2_fs.h"
  29 #else
  30 #include <linux/ext2_fs.h>
  31 #endif
  32
  33 #include "ext2fs.h"
  34
  35 struct get_pathname_struct {
  36         ino_t           search_ino;
  37         ino_t           parent;
  38         char            *name;
  39         errcode_t       errcode;
  40 };
  41
  42 #ifdef __TURBOC__
  43 #pragma argsused
  44 #endif
  45 static int get_pathname_proc(struct ext2_dir_entry *dirent,
  46                              int        offset,
  47                              int        blocksize,
  48                              char       *buf,
  49                              void       *priv_data)
  50 {
  51         struct get_pathname_struct      *gp;
  52         errcode_t                       retval;
  53
  54         gp = (struct get_pathname_struct *) priv_data;
  55
  56         if (((dirent->name_len & 0xFF) == 2) &&
  57             !strncmp(dirent->name, "..", 2))
  58                 gp->parent = dirent->inode;
  59         if (dirent->inode == gp->search_ino) {
  60                 retval = ext2fs_get_mem((dirent->name_len & 0xFF) + 1,
  61                                         (void **) &gp->name);
  62                 if (retval) {
  63                         gp->errcode = retval;
  64                         return DIRENT_ABORT;
  65                 }
  66                 strncpy(gp->name, dirent->name, (dirent->name_len & 0xFF));
  67                 gp->name[dirent->name_len & 0xFF] = '\0';
  68                 return DIRENT_ABORT;
  69         }
  70         return 0;
  71 }
  72
  73 static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ino_t dir, ino_t ino,
  74                                          int maxdepth, char *buf, char **name)
  75 {
  76         struct get_pathname_struct gp;
  77         char    *parent_name, *ret;
  78         errcode_t       retval;
  79
  80         if (dir == ino) {
  81                 retval = ext2fs_get_mem(2, (void **)name);
  82                 if (retval)
  83                         return retval;
  84                 strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
  85                 return 0;
  86         }
  87
  88         if (!dir || (maxdepth < 0)) {
  89                 retval = ext2fs_get_mem(4, (void **)name);
  90                 if (retval)
  91                         return retval;
  92                 strcpy(*name, "...");
  93                 return 0;
  94         }
  95
  96         gp.search_ino = ino;
  97         gp.parent = 0;
  98         gp.name = 0;
  99         gp.errcode = 0;
 100
 101         retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
 102         if (retval)
 103                 goto cleanup;
 104         if (gp.errcode) {
 105                 retval = gp.errcode;
 106                 goto cleanup;
 107         }
 108
 109         retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
 110                                          buf, &parent_name);
 111         if (retval)
 112                 goto cleanup;
 113         if (!ino) {
 114                 *name = parent_name;
 115                 return 0;
 116         }
 117
 118         if (gp.name)
 119                 retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
 120                                         (void **) &ret);
 121         else
 122                 retval = ext2fs_get_mem(strlen(parent_name)+5,
 123                                         (void **) &ret);
 124         if (retval)
 125                 goto cleanup;
 126
 127         ret[0] = 0;
 128         if (parent_name[1])
 129                 strcat(ret, parent_name);
 130         strcat(ret, "/");
 131         if (gp.name)
 132                 strcat(ret, gp.name);
 133         else
 134                 strcat(ret, "???");
 135         *name = ret;
 136         ext2fs_free_mem((void **) &parent_name);
 137         retval = 0;
 138
 139 cleanup:
 140         if (gp.name)
 141                 ext2fs_free_mem((void **) &gp.name);
 142         return retval;
 143 }
 144
 145 errcode_t ext2fs_get_pathname(ext2_filsys fs, ino_t dir, ino_t ino,
 146                               char **name)
 147 {
 148         char    *buf;
 149         errcode_t       retval;
 150
 151         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 152
 153         retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
 154         if (retval)
 155                 return retval;
 156         if (dir == ino)
 157                 ino = 0;
 158         retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
 159         ext2fs_free_mem((void **) &buf);
 160         return retval;
 161
 162 }