glibc/hurd/fd-read.c
2012-02-09 23:18:22 +00:00

55 lines
1.6 KiB
C

/* Copyright (C) 1993,94,95,97,99,2002,2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <string.h>
error_t
_hurd_fd_read (struct hurd_fd *fd, void *buf, size_t *nbytes, loff_t offset)
{
error_t err;
char *data;
mach_msg_type_number_t nread;
error_t readfd (io_t port)
{
return __io_read (port, &data, &nread, offset, *nbytes);
}
data = buf;
nread = *nbytes;
if (err = HURD_FD_PORT_USE (fd, _hurd_ctty_input (port, ctty, readfd)))
return err;
if (data != buf)
{
if (nread > *nbytes) /* Sanity check for bogus server. */
{
__vm_deallocate (__mach_task_self (), (vm_address_t) data, nread);
return EGRATUITOUS;
}
memcpy (buf, data, nread);
__vm_deallocate (__mach_task_self (), (vm_address_t) data, nread);
}
*nbytes = nread;
return 0;
}