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/* File channel backend.
Copyright (C) 1995, 1996, 1997, 1998, 2001, 2002, 2007
Free Software Foundation, Inc.
Written by Miles Bader <miles@gnu.org>
Reworked for libchannel by Carl Fredrik Hammar <hammy.lite@gmail.com>
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
The GNU Hurd 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <hurd.h>
#include <hurd/io.h>
#include <hurd/fs.h>
#include "channel.h"
static error_t
file_read (struct channel *channel, size_t amount, void **buf, size_t *len)
{
return io_read ((mach_port_t)channel->class_hook,
(char **)buf, len, -1, amount);
}
static error_t
file_write (struct channel *channel, void *buf, size_t len,
size_t *amount)
{
return io_write ((mach_port_t)channel->class_hook, buf, len, -1, amount);
}
static error_t
file_flush (struct channel *channel)
{
return file_sync ((mach_port_t)channel->class_hook, 0, 1);
}
static error_t
file_open (struct channel *channel, int flags)
{
struct channel_hub *hub = channel->hub;
file_t file;
error_t err;
if (flags & CHANNEL_READONLY)
file = file_name_lookup (hub->name, O_READ, 0);
else if (flags & CHANNEL_WRITEONLY)
file = file_name_lookup (hub->name, O_WRITE, 0);
else
{
file = file_name_lookup (hub->name, O_RDWR, 0);
if (file == MACH_PORT_NULL
&& (errno == EACCES || errno == EROFS))
{
file = file_name_lookup (hub->name, O_READ, 0);
if (file != MACH_PORT_NULL)
flags |= CHANNEL_READONLY;
}
if (file == MACH_PORT_NULL
&& (errno == EACCES || errno == EROFS))
{
file = file_name_lookup (hub->name, O_WRITE, 0);
if (file != MACH_PORT_NULL)
flags |= CHANNEL_WRITEONLY;
}
}
err = file == MACH_PORT_NULL ? errno : 0;
if (err)
return err;
channel->flags = flags;
channel->class_hook = (void*) file;
return 0;
}
static void
file_close (struct channel *channel)
{
mach_port_deallocate (mach_task_self (),
(mach_port_t)channel->class_hook);
}
/* XXX implement control_demuxer. */
const struct channel_class
channel_file_class =
{
name: "file",
read: file_read,
write: file_write,
flush: file_flush,
open: file_open,
close: file_close,
create_hub: channel_create_file_hub
};
CHANNEL_STD_CLASS (file);
/* Create and return in HUB a hub that creates channels that does file i/o
with the file specified by NAME. */
error_t
channel_create_file_hub (const char *name, int flags,
const struct channel_class *const *classes,
struct channel_hub **hub)
{
return channel_alloc_hub (&channel_file_class, name, flags, hub);
}
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