Subversion Repositories HelenOS

/*
 * 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 <ipc/ipc.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <as.h>
#include <libfs.h>
#include <ipc/services.h>
#include <ipc/devmap.h>
#include <sys/mman.h>
#include <byteorder.h>

#define BLOCK_SIZE          1024    // FIXME
#define RD_BASE             1024    // FIXME
#define RD_READ_BLOCK   (RD_BASE + 1)

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

static bool 
tmpfs_blockread(int phone, void *buffer, size_t *bufpos, size_t *buflen,
    size_t *pos, void *dst, size_t size)
{
    size_t offset = 0;
    size_t left = size;
    
    while (left > 0) {
        size_t rd;
        
        if (*bufpos + left < *buflen)
            rd = left;
        else
            rd = *buflen - *bufpos;
        
        if (rd > 0) {
            memcpy(dst + offset, buffer + *bufpos, rd);
            offset += rd;
            *bufpos += rd;
            *pos += rd;
            left -= rd;
        }
        
        if (*bufpos == *buflen) {
            ipcarg_t retval;
            int rc = ipc_call_sync_2_1(phone, RD_READ_BLOCK,
                *pos / BLOCK_SIZE, BLOCK_SIZE,
                &retval);
            if ((rc != EOK) || (retval != EOK))
                return false;
            
            *bufpos = 0;
            *buflen = BLOCK_SIZE;
        }
    }
    
    return true;
}

static bool
tmpfs_restore_recursion(int phone, void *block, size_t *bufpos, size_t *buflen,
    size_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 (!tmpfs_blockread(phone, block, bufpos, buflen, pos, &entry,
            sizeof(entry)))
            return false;
        
        entry.len = uint32_t_le2host(entry.len);
        
        switch (entry.type) {
        case 0:
            break;
        case 1:
            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 (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                fname, entry.len)) {
                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_blockread(phone, block, bufpos, buflen, pos,
                &size, sizeof(size)))
                return false;
            
            size = uint32_t_le2host(size);
            
            node->data = malloc(size);
            if (node->data == NULL)
                return false;
            
            node->size = size;
            if (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                node->data, size))
                return false;
            
            break;
        case 2:
            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 (!tmpfs_blockread(phone, block, bufpos, buflen, pos,
                fname, entry.len)) {
                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(phone, block, bufpos,
                buflen, pos, node))
                return false;
            
            break;
        default:
            return false;
        }
    } while (entry.type != 0);
    
    return true;
}

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

    void *block = mmap(NULL, BLOCK_SIZE,
        PROTO_READ | PROTO_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
    
    if (block == NULL)
        return false;
    
    int phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
        DEVMAP_CONNECT_TO_DEVICE, dev);

    if (phone < 0) {
        munmap(block, BLOCK_SIZE);
        return false;
    }
    
    if (ipc_share_out_start(phone, block, AS_AREA_READ | AS_AREA_WRITE) !=
        EOK)
        goto error;
    
    size_t bufpos = 0;
    size_t buflen = 0;
    size_t pos = 0;
    
    char tag[6];
    if (!tmpfs_blockread(phone, block, &bufpos, &buflen, &pos, tag, 5))
        goto error;
    
    tag[5] = 0;
    if (strcmp(tag, "TMPFS") != 0)
        goto error;
    
    if (!tmpfs_restore_recursion(phone, block, &bufpos, &buflen, &pos,
        ops->root_get(dev)))
        goto error;
        
    ipc_hangup(phone);
    munmap(block, BLOCK_SIZE);
    return true;
    
error:
    ipc_hangup(phone);
    munmap(block, BLOCK_SIZE);
    return false;
}

/**
 * @}
 */