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/*
 * Copyright (c) 2008 Jakub Jermar 
 * Copyright (c) 2008 Martin Decky 
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup fs
 * @{
 */ 

/**
 * @file    tmpfs_dump.c
 * @brief   Support for loading TMPFS file system dump.
 */

#include "tmpfs.h"
#include "../../vfs/vfs.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <as.h>
#include <libblock.h>
#include <byteorder.h>

#define TMPFS_BLOCK_SIZE    1024

struct rdentry {
    uint8_t type;
    uint32_t len;
} __attribute__((packed));

static bool
tmpfs_restore_recursion(int dev, off_t *bufpos, size_t *buflen, off_t *pos,
    tmpfs_dentry_t *parent)
{
    struct rdentry entry;
    libfs_ops_t *ops = &tmpfs_libfs_ops;
    
    do {
        char *fname;
        tmpfs_dentry_t *node;
        uint32_t size;
        
        if (block_read(dev, bufpos, buflen, pos, &entry, sizeof(entry),
            TMPFS_BLOCK_SIZE) != EOK)
            return false;
        
        entry.len = uint32_t_le2host(entry.len);
        
        switch (entry.type) {
        case TMPFS_NONE:
            break;
        case TMPFS_FILE:
            fname = malloc(entry.len + 1);
            if (fname == NULL)
                return false;
            
            node = (tmpfs_dentry_t *) ops->create(L_FILE);
            if (node == NULL) {
                free(fname);
                return false;
            }
            
            if (block_read(dev, bufpos, buflen, pos, fname,
                entry.len, TMPFS_BLOCK_SIZE) != EOK) {
                ops->destroy((void *) node);
                free(fname);
                return false;
            }
            fname[entry.len] = 0;
            
            if (!ops->link((void *) parent, (void *) node, fname)) {
                ops->destroy((void *) node);
                free(fname);
                return false;
            }
            free(fname);
            
            if (block_read(dev, bufpos, buflen, pos, &size,
                sizeof(size), TMPFS_BLOCK_SIZE) != EOK)
                return false;
            
            size = uint32_t_le2host(size);
            
            node->data = malloc(size);
            if (node->data == NULL)
                return false;
            
            node->size = size;
            if (block_read(dev, bufpos, buflen, pos, node->data,
                size, TMPFS_BLOCK_SIZE) != EOK)
                return false;
            
            break;
        case TMPFS_DIRECTORY:
            fname = malloc(entry.len + 1);
            if (fname == NULL)
                return false;
            
            node = (tmpfs_dentry_t *) ops->create(L_DIRECTORY);
            if (node == NULL) {
                free(fname);
                return false;
            }
            
            if (block_read(dev, bufpos, buflen, pos, fname,
                entry.len, TMPFS_BLOCK_SIZE) != EOK) {
                ops->destroy((void *) node);
                free(fname);
                return false;
            }
            fname[entry.len] = 0;
            
            if (!ops->link((void *) parent, (void *) node, fname)) {
                ops->destroy((void *) node);
                free(fname);
                return false;
            }
            free(fname);
            
            if (!tmpfs_restore_recursion(dev, bufpos, buflen, pos,
                node))
                return false;
            
            break;
        default:
            return false;
        }
    } while (entry.type != TMPFS_NONE);
    
    return true;
}

bool tmpfs_restore(dev_handle_t dev)
{
    libfs_ops_t *ops = &tmpfs_libfs_ops;
    int rc;

    rc = block_init(dev, TMPFS_BLOCK_SIZE);
    if (rc != EOK)
        return false; 
    
    off_t bufpos = 0;
    size_t buflen = 0;
    off_t pos = 0;
    
    char tag[6];
    if (block_read(dev, &bufpos, &buflen, &pos, tag, 5,
        TMPFS_BLOCK_SIZE) != EOK)
        goto error;
    
    tag[5] = 0;
    if (strcmp(tag, "TMPFS") != 0)
        goto error;
    
    if (!tmpfs_restore_recursion(dev, &bufpos, &buflen, &pos,
        ops->root_get(dev)))
        goto error;
        
    block_fini(dev);
    return true;
    
error:
    block_fini(dev);
    return false;
}

/**
 * @}
 */