Ext2Symlink.cc

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "Ext2Symlink.h"
#include "Ext2Filesystem.h"
#include "ext2.h"
#include "pedigree/kernel/Log.h"
#include "pedigree/kernel/processor/types.h"
#include "pedigree/kernel/utilities/utility.h"

class File;
class Filesystem;

Ext2Symlink::Ext2Symlink(
    const String &name, uintptr_t inode_num, Inode *inode, Ext2Filesystem *pFs,
    File *pParent)
    : Symlink(
          name, LITTLE_TO_HOST32(inode->i_atime),
          LITTLE_TO_HOST32(inode->i_mtime), LITTLE_TO_HOST32(inode->i_ctime),
          inode_num, static_cast<Filesystem *>(pFs),
          LITTLE_TO_HOST32(inode->i_size),  
          pParent),
      Ext2Node(inode_num, inode, pFs)
{
    uint32_t mode = LITTLE_TO_HOST32(inode->i_mode);
    setPermissionsOnly(modeToPermissions(mode));
    setUidOnly(LITTLE_TO_HOST16(inode->i_uid));
    setGidOnly(LITTLE_TO_HOST16(inode->i_gid));
}

Ext2Symlink::~Ext2Symlink()
{
}

uint64_t Ext2Symlink::readBytewise(
    uint64_t location, uint64_t size, uintptr_t buffer, bool canBlock)
{
    if (location >= getSize())
        return 0;
    if ((location + size) >= getSize())
        size = getSize() - location;
    if (!size)
        return 0;

    if (getSize() && Ext2Node::getInode()->i_blocks == 0)
    {
        MemoryCopy(
            reinterpret_cast<void *>(buffer),
            adjust_pointer(m_pInode->i_block, location), size);
        return size;
    }

    if (getSize() > m_pExt2Fs->m_BlockSize)
    {
        WARNING("Ext2: rather large symlink found, not handled yet");
        return 0;
    }

    uintptr_t block = Ext2Node::readBlock(location);
    size_t offset = location % m_pExt2Fs->m_BlockSize;
    MemoryCopy(
        reinterpret_cast<void *>(buffer),
        reinterpret_cast<void *>(block + offset), size);
    m_Size = m_nSize;
    return size;
}

uint64_t Ext2Symlink::writeBytewise(
    uint64_t location, uint64_t size, uintptr_t buffer, bool canBlock)
{
    Ext2Node::extend(size);
    m_Size = m_nSize;

    if (getSize() > m_pExt2Fs->m_BlockSize)
    {
        WARNING("Ext2: rather large symlink found, not handled yet");
        return 0;
    }

    uintptr_t block = Ext2Node::readBlock(location);
    size_t offset = location % m_pExt2Fs->m_BlockSize;
    MemoryCopy(
        adjust_pointer(reinterpret_cast<void *>(block), offset),
        reinterpret_cast<void *>(buffer), size);
    Ext2Node::writeBlock(location);
    return size;
}

void Ext2Symlink::truncate()
{
    Ext2Node::wipe();
    m_Size = m_nSize;
}

void Ext2Symlink::fileAttributeChanged()
{
    static_cast<Ext2Node *>(this)->fileAttributeChanged(
        m_Size, m_AccessedTime, m_ModifiedTime, m_CreationTime);
    static_cast<Ext2Node *>(this)->updateMetadata(
        getUid(), getGid(), permissionsToMode(getPermissions()));
}