rockbox/apps/open_plugin.h
William Wilgus e1553d860d Open_Plugin add checksum on struct offsets
Adding a checksum over the struct offset will allow checking
for compatibility across machines rather than using packed structs
to ensure compability

For any file created by the user from the device  this isn't really a concern

But for files between machines, across installs (sim v device),
possibly even across compilers this at least will alert the user
rather than returning junk data

Change-Id: Id0531bbaa7013dce24dece270849f0a10ac99c20
2021-10-18 23:30:27 -04:00

89 lines
3.1 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2020 by William Wilgus
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef OPEN_PLUGIN_H
#define OPEN_PLUGIN_H
/* Open_plugin module
* OP stores and retrieves plugin path and parameters by key
* from a dictionary file
*
* plugins can load other plugins
* return rb->plugin_open(path, parameter);
*/
#ifndef __PCTOOL__
/* open_plugin path lookup */
#define OPEN_PLUGIN_DAT PLUGIN_DIR "/plugin.dat"
#define OPEN_RBPLUGIN_DAT PLUGIN_DIR "/rb_plugins.dat"
#define OPEN_PLUGIN_BUFSZ MAX_PATH
#define OPEN_PLUGIN_NAMESZ 32
enum {
OPEN_PLUGIN_LANG_INVALID = (-1),
OPEN_PLUGIN_LANG_IGNORE = (-2),
OPEN_PLUGIN_LANG_IGNOREALL = (-3),
OPEN_PLUGIN_NOT_FOUND = (-1),
OPEN_PLUGIN_NEEDS_FLUSHED = (-2),
};
struct open_plugin_entry_t
{
/* hash lang_id checksum need to be the first items */
uint32_t hash;
int32_t lang_id;
uint32_t checksum;
char name[OPEN_PLUGIN_NAMESZ+1];
/*char key[OPEN_PLUGIN_BUFSZ+1];*/
char path[OPEN_PLUGIN_BUFSZ+1];
char param[OPEN_PLUGIN_BUFSZ+1];
};
#define OPEN_PLUGIN_CHECKSUM (uint32_t) \
( \
(sizeof(struct open_plugin_entry_t) << 16) + \
offsetof(struct open_plugin_entry_t, hash) + \
offsetof(struct open_plugin_entry_t, lang_id) + \
offsetof(struct open_plugin_entry_t, checksum) + \
offsetof(struct open_plugin_entry_t, name) + \
/*offsetof(struct open_plugin_entry_t, key)+*/ \
offsetof(struct open_plugin_entry_t, path) + \
offsetof(struct open_plugin_entry_t, param))
inline static void open_plugin_get_hash(const char *key, uint32_t *hash)
{
/* Calculate modified FNV1a hash of string */
const uint32_t p = 16777619;
*hash = 0x811C9DC5; //seed, 2166136261;
while(*key)
*hash = (*key++ ^ *hash) * p;
}
#ifndef PLUGIN
extern struct open_plugin_entry_t open_plugin_entry;
uint32_t open_plugin_add_path(const char *key, const char *plugin, const char *parameter);
int open_plugin_get_entry(const char *key, struct open_plugin_entry_t *entry);
void open_plugin_browse(const char *key);
int open_plugin_run(const char *key);
void open_plugin_cache_flush(void); /* flush to disk */
#endif
#endif /*ndef __PCTOOL__ */
#endif /* OPEN_PLUGIN_H */