ro_file_impl.h

/*
 * (c) 2010 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *          Alexander Warg <warg@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU General Public License 2.
 * Please see the COPYING-GPL-2 file for details.
 *
 * As a special exception, you may use this file as part of a free software
 * library without restriction.  Specifically, if other files instantiate
 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
 * file does not by itself cause the resulting executable to be covered by
 * the GNU General Public License.  This exception does not however
 * invalidate any other reasons why the executable file might be covered by
 * the GNU General Public License.
 */
 
#include "ro_file.h"
 
#include <sys/ioctl.h>
 
#include <l4/re/env>
 
namespace L4Re { namespace Core {
 
Ro_file::~Ro_file() noexcept
{
  if (_addr)
    L4Re::Env::env()->rm()->detach(l4_addr_t(_addr), 0);
 
  L4Re::virt_cap_alloc->release(_ds);
}
 
int
Ro_file::fstat64(struct stat64 *buf) const noexcept
{
  static int fake = 0;
 
  memset(buf, 0, sizeof(*buf));
  buf->st_size = _size;
  buf->st_mode = S_IFREG | 0644;
  buf->st_dev = _ds.cap();
  buf->st_ino = ++fake;
  buf->st_blksize = L4_PAGESIZE;
  buf->st_blocks = l4_round_page(_size);
  return 0;
}
 
ssize_t
Ro_file::read_single(const struct iovec *vec, off64_t pos) noexcept
{
  off64_t l = vec->iov_len;
  if (_size - pos < l)
    l = _size - pos;
 
  if (l > 0)
    {
      Vfs_config::memcpy(vec->iov_base, _addr + pos, l);
      return l;
    }
 
  return 0;
}
 
ssize_t
Ro_file::preadv(const struct iovec *vec, int cnt, off64_t offset) noexcept
{
  if (!_addr)
    {
      void const *file = reinterpret_cast<void*>(L4_PAGESIZE);
      long err = L4Re::Env::env()->rm()->attach(&file, _size,
                                                Rm::F::Search_addr | Rm::F::R,
                                                _ds, 0);
 
      if (err < 0)
        return err;
 
      _addr = static_cast<char const *>(file);
    }
 
  ssize_t l = 0;
 
  while (cnt > 0)
    {
      ssize_t r = read_single(vec, offset);
      offset += r;
      l += r;
 
      if (static_cast<size_t>(r) < vec->iov_len)
        return l;
 
      ++vec;
      --cnt;
    }
  return l;
}
 
ssize_t
Ro_file::pwritev(const struct iovec *, int, off64_t) noexcept
{
  return -EROFS;
}
 
int
Ro_file::ioctl(unsigned long v, va_list args) noexcept
{
  switch (v)
    {
    case FIONREAD: // return amount of data still available
      int *available = va_arg(args, int *);
      *available = _size - pos();
      return 0;
    };
  return -ENOTTY;
}
 
}}