firmware/common/dir_uncached.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id: dir.c 13741 2007-06-30 02:08:27Z jethead71 $
   9  *
  10  * Copyright (C) 2002 by Björn Stenberg
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include <stdio.h>
  22 #include <errno.h>
  23 #include <string.h>
  24 #include <stdbool.h>
  25 #include <stdlib.h>
  26 #include "fat.h"
  27 #include "dir.h"
  28 #include "debug.h"
  29 #include "filefuncs.h"
  30
  31 #if ((defined(MEMORYSIZE) && (MEMORYSIZE > 8)) || MEM > 8)
  32 #define MAX_OPEN_DIRS 12
  33 #else
  34 #define MAX_OPEN_DIRS 8
  35 #endif
  36
  37 static DIR_UNCACHED opendirs[MAX_OPEN_DIRS];
  38
  39 #ifdef HAVE_HOTSWAP
  40 // release all dir handles on a given volume "by force", to avoid leaks
  41 int release_dirs(int volume)
  42 {
  43     DIR_UNCACHED* pdir = opendirs;
  44     int dd;
  45     int closed = 0;
  46     for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)
  47     {
  48 #ifdef HAVE_MULTIVOLUME
  49         if (pdir->fatdir.file.volume == volume)
  50 #else
  51         (void)volume;
  52 #endif
  53         {
  54             pdir->busy = false; /* mark as available, no further action */
  55             closed++;
  56         }
  57     }
  58     return closed; /* return how many we did */
  59 }
  60 #endif /* #ifdef HAVE_HOTSWAP */
  61
  62 DIR_UNCACHED* opendir_uncached(const char* name)
  63 {
  64     char namecopy[MAX_PATH];
  65     char* part;
  66     char* end;
  67     struct fat_direntry entry;
  68     int dd;
  69     DIR_UNCACHED* pdir = opendirs;
  70 #ifdef HAVE_MULTIVOLUME
  71     int volume;
  72 #endif
  73
  74     if ( name[0] != '/' ) {
  75         DEBUGF("Only absolute paths supported right now\n");
  76         return NULL;
  77     }
  78
  79     /* find a free dir descriptor */
  80     for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)
  81         if ( !pdir->busy )
  82             break;
  83
  84     if ( dd == MAX_OPEN_DIRS ) {
  85         DEBUGF("Too many dirs open\n");
  86         errno = EMFILE;
  87         return NULL;
  88     }
  89
  90     pdir->busy = true;
  91
  92 #ifdef HAVE_MULTIVOLUME
  93     /* try to extract a heading volume name, if present */
  94     volume = strip_volume(name, namecopy);
  95     pdir->volumecounter = 0;
  96 #else
  97     strlcpy(namecopy, name, sizeof(namecopy)); /* just copy */
  98 #endif
  99
 100     if ( fat_opendir(IF_MV2(volume,) &pdir->fatdir, 0, NULL) < 0 ) {
 101         DEBUGF("Failed opening root dir\n");
 102         pdir->busy = false;
 103         return NULL;
 104     }
 105
 106     for ( part = strtok_r(namecopy, "/", &end); part;
 107           part = strtok_r(NULL, "/", &end)) {
 108         /* scan dir for name */
 109         while (1) {
 110             if ((fat_getnext(&pdir->fatdir,&entry) < 0) ||
 111                 (!entry.name[0])) {
 112                 pdir->busy = false;
 113                 return NULL;
 114             }
 115             if ( (entry.attr & FAT_ATTR_DIRECTORY) &&
 116                  (!strcasecmp(part, entry.name)) ) {
 117                 /* In reality, the parent_dir parameter of fat_opendir seems
 118                  * useless because it's sole purpose it to have a way to
 119                  * update the file metadata, but here we are only reading
 120                  * a directory so there's no need for that kind of stuff.
 121                  * However, the rmdir_uncached function uses a ugly hack to
 122                  * avoid opening a directory twice when deleting it and thus
 123                  * needs those information. That's why we pass pdir->fatdir both
 124                  * as the parent directory and the resulting one (this is safe,
 125                  * in doubt, check fat_open(dir) code) which will allow this kind of
 126                  * (ugly) things */
 127                 if ( fat_opendir(IF_MV2(volume,)
 128                                  &pdir->fatdir,
 129                                  entry.firstcluster,
 130                                  &pdir->fatdir) < 0 ) {
 131                     DEBUGF("Failed opening dir '%s' (%ld)\n",
 132                            part, entry.firstcluster);
 133                     pdir->busy = false;
 134                     return NULL;
 135                 }
 136 #ifdef HAVE_MULTIVOLUME
 137                 pdir->volumecounter = -1; /* n.a. to subdirs */
 138 #endif
 139                 break;
 140             }
 141         }
 142     }
 143
 144     return pdir;
 145 }
 146
 147 int closedir_uncached(DIR_UNCACHED* dir)
 148 {
 149     dir->busy=false;
 150     return 0;
 151 }
 152
 153 struct dirent_uncached* readdir_uncached(DIR_UNCACHED* dir)
 154 {
 155     struct fat_direntry entry;
 156     struct dirent_uncached* theent = &(dir->theent);
 157
 158     if (!dir->busy)
 159         return NULL;
 160
 161 #ifdef HAVE_MULTIVOLUME
 162     /* Volumes (secondary file systems) get inserted into the root directory
 163         of the first volume, since we have no separate top level. */
 164     if (dir->volumecounter >= 0 /* on a root dir */
 165      && dir->volumecounter < NUM_VOLUMES /* in range */
 166      && dir->fatdir.file.volume == 0) /* at volume 0 */
 167     {   /* fake special directories, which don't really exist, but
 168            will get redirected upon opendir_uncached() */
 169         while (++dir->volumecounter < NUM_VOLUMES)
 170         {
 171             if (fat_ismounted(dir->volumecounter))
 172             {
 173                 memset(theent, 0, sizeof(*theent));
 174                 theent->attribute = FAT_ATTR_DIRECTORY | FAT_ATTR_VOLUME;
 175                 snprintf(theent->d_name, sizeof(theent->d_name),
 176                          VOL_NAMES, dir->volumecounter);
 177                 return theent;
 178             }
 179         }
 180     }
 181 #endif
 182     /* normal directory entry fetching follows here */
 183     if (fat_getnext(&(dir->fatdir),&entry) < 0)
 184         return NULL;
 185
 186     if ( !entry.name[0] )
 187         return NULL;
 188
 189     strlcpy(theent->d_name, entry.name, sizeof(theent->d_name));
 190     theent->attribute = entry.attr;
 191     theent->size = entry.filesize;
 192     theent->startcluster = entry.firstcluster;
 193     theent->wrtdate = entry.wrtdate;
 194     theent->wrttime = entry.wrttime;
 195
 196     return theent;
 197 }
 198
 199 int mkdir_uncached(const char *name)
 200 {
 201     DIR_UNCACHED *dir;
 202     char namecopy[MAX_PATH];
 203     char* end;
 204     char *basename;
 205     char *parent;
 206     struct dirent_uncached *entry;
 207     struct fat_dir newdir;
 208     int rc;
 209
 210     if ( name[0] != '/' ) {
 211         DEBUGF("mkdir: Only absolute paths supported right now\n");
 212         return -1;
 213     }
 214
 215     strlcpy(namecopy, name, sizeof(namecopy));
 216
 217     /* Split the base name and the path */
 218     end = strrchr(namecopy, '/');
 219     *end = 0;
 220     basename = end+1;
 221
 222     if(namecopy == end) /* Root dir? */
 223         parent = "/";
 224     else
 225         parent = namecopy;
 226
 227     DEBUGF("mkdir: parent: %s, name: %s\n", parent, basename);
 228
 229     dir = opendir_uncached(parent);
 230
 231     if(!dir) {
 232         DEBUGF("mkdir: can't open parent dir\n");
 233         return -2;
 234     }
 235
 236     if(basename[0] == 0) {
 237         DEBUGF("mkdir: Empty dir name\n");
 238         errno = EINVAL;
 239         return -3;
 240     }
 241
 242     /* Now check if the name already exists */
 243     while ((entry = readdir_uncached(dir))) {
 244         if ( !strcasecmp(basename, entry->d_name) ) {
 245             DEBUGF("mkdir error: file exists\n");
 246             errno = EEXIST;
 247             closedir_uncached(dir);
 248             return - 4;
 249         }
 250     }
 251
 252     memset(&newdir, 0, sizeof(struct fat_dir));
 253
 254     rc = fat_create_dir(basename, &newdir, &(dir->fatdir));
 255     closedir_uncached(dir);
 256
 257     return rc;
 258 }
 259
 260 int rmdir_uncached(const char* name)
 261 {
 262     int rc;
 263     DIR_UNCACHED* dir;
 264     struct dirent_uncached* entry;
 265
 266     dir = opendir_uncached(name);
 267     if (!dir)
 268     {
 269         errno = ENOENT; /* open error */
 270         return -1;
 271     }
 272
 273     /* check if the directory is empty */
 274     while ((entry = readdir_uncached(dir)))
 275     {
 276         if (strcmp(entry->d_name, ".") &&
 277             strcmp(entry->d_name, ".."))
 278         {
 279             DEBUGF("rmdir error: not empty\n");
 280             errno = ENOTEMPTY;
 281             closedir_uncached(dir);
 282             return -2;
 283         }
 284     }
 285
 286     rc = fat_remove(&(dir->fatdir.file));
 287     if ( rc < 0 ) {
 288         DEBUGF("Failed removing dir: %d\n", rc);
 289         errno = EIO;
 290         rc = rc * 10 - 3;
 291     }
 292
 293     closedir_uncached(dir);
 294     return rc;
 295 }