linux/fs/9p/trans_fd.c

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/*
* linux/fs/9p/trans_fd.c
*
* Fd transport layer. Includes deprecated socket layer.
*
* Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
* Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004-2005 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program 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:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/in.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/un.h>
#include <asm/uaccess.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
#include "debug.h"
#include "v9fs.h"
#include "transport.h"
#define V9FS_PORT 564
struct v9fs_trans_fd {
struct file *rd;
struct file *wr;
};
/**
* v9fs_fd_read- read from a fd
* @v9ses: session information
* @v: buffer to receive data into
* @len: size of receive buffer
*
*/
static int v9fs_fd_read(struct v9fs_transport *trans, void *v, int len)
{
int ret;
struct v9fs_trans_fd *ts;
if (!trans || trans->status == Disconnected || !(ts = trans->priv))
return -EREMOTEIO;
if (!(ts->rd->f_flags & O_NONBLOCK))
dprintk(DEBUG_ERROR, "blocking read ...\n");
ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
trans->status = Disconnected;
return ret;
}
/**
* v9fs_fd_write - write to a socket
* @v9ses: session information
* @v: buffer to send data from
* @len: size of send buffer
*
*/
static int v9fs_fd_write(struct v9fs_transport *trans, void *v, int len)
{
int ret;
mm_segment_t oldfs;
struct v9fs_trans_fd *ts;
if (!trans || trans->status == Disconnected || !(ts = trans->priv))
return -EREMOTEIO;
if (!(ts->wr->f_flags & O_NONBLOCK))
dprintk(DEBUG_ERROR, "blocking write ...\n");
oldfs = get_fs();
set_fs(get_ds());
/* The cast to a user pointer is valid due to the set_fs() */
ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
set_fs(oldfs);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
trans->status = Disconnected;
return ret;
}
static unsigned int
v9fs_fd_poll(struct v9fs_transport *trans, struct poll_table_struct *pt)
{
int ret, n;
struct v9fs_trans_fd *ts;
mm_segment_t oldfs;
if (!trans || trans->status != Connected || !(ts = trans->priv))
return -EREMOTEIO;
if (!ts->rd->f_op || !ts->rd->f_op->poll)
return -EIO;
if (!ts->wr->f_op || !ts->wr->f_op->poll)
return -EIO;
oldfs = get_fs();
set_fs(get_ds());
ret = ts->rd->f_op->poll(ts->rd, pt);
if (ret < 0)
goto end;
if (ts->rd != ts->wr) {
n = ts->wr->f_op->poll(ts->wr, pt);
if (n < 0) {
ret = n;
goto end;
}
ret = (ret & ~POLLOUT) | (n & ~POLLIN);
}
end:
set_fs(oldfs);
return ret;
}
static int v9fs_fd_open(struct v9fs_session_info *v9ses, int rfd, int wfd)
{
struct v9fs_transport *trans = v9ses->transport;
struct v9fs_trans_fd *ts = kmalloc(sizeof(struct v9fs_trans_fd),
GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->rd = fget(rfd);
ts->wr = fget(wfd);
if (!ts->rd || !ts->wr) {
if (ts->rd)
fput(ts->rd);
if (ts->wr)
fput(ts->wr);
kfree(ts);
return -EIO;
}
trans->priv = ts;
trans->status = Connected;
return 0;
}
static int v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr,
char *data)
{
if (v9ses->rfdno == ~0 || v9ses->wfdno == ~0) {
printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
return -ENOPROTOOPT;
}
return v9fs_fd_open(v9ses, v9ses->rfdno, v9ses->wfdno);
}
static int v9fs_socket_open(struct v9fs_session_info *v9ses,
struct socket *csocket)
{
int fd, ret;
csocket->sk->sk_allocation = GFP_NOIO;
if ((fd = sock_map_fd(csocket)) < 0) {
eprintk(KERN_ERR, "v9fs_socket_open: failed to map fd\n");
ret = fd;
release_csocket:
sock_release(csocket);
return ret;
}
if ((ret = v9fs_fd_open(v9ses, fd, fd)) < 0) {
sockfd_put(csocket);
eprintk(KERN_ERR, "v9fs_socket_open: failed to open fd\n");
goto release_csocket;
}
((struct v9fs_trans_fd *)v9ses->transport->priv)->rd->f_flags |=
O_NONBLOCK;
return 0;
}
static int v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr,
char *data)
{
int ret;
struct socket *csocket = NULL;
struct sockaddr_in sin_server;
sin_server.sin_family = AF_INET;
sin_server.sin_addr.s_addr = in_aton(addr);
sin_server.sin_port = htons(v9ses->port);
sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
if (!csocket) {
eprintk(KERN_ERR, "v9fs_trans_tcp: problem creating socket\n");
return -1;
}
ret = csocket->ops->connect(csocket,
(struct sockaddr *)&sin_server,
sizeof(struct sockaddr_in), 0);
if (ret < 0) {
eprintk(KERN_ERR,
"v9fs_trans_tcp: problem connecting socket to %s\n",
addr);
return ret;
}
return v9fs_socket_open(v9ses, csocket);
}
static int
v9fs_unix_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
{
int ret;
struct socket *csocket;
struct sockaddr_un sun_server;
if (strlen(addr) > UNIX_PATH_MAX) {
eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
addr);
return -ENAMETOOLONG;
}
sun_server.sun_family = PF_UNIX;
strcpy(sun_server.sun_path, addr);
sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
ret = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
sizeof(struct sockaddr_un) - 1, 0);
if (ret < 0) {
eprintk(KERN_ERR,
"v9fs_trans_unix: problem connecting socket: %s: %d\n",
addr, ret);
return ret;
}
return v9fs_socket_open(v9ses, csocket);
}
/**
* v9fs_sock_close - shutdown socket
* @trans: private socket structure
*
*/
static void v9fs_fd_close(struct v9fs_transport *trans)
{
struct v9fs_trans_fd *ts;
if (!trans)
return;
ts = xchg(&trans->priv, NULL);
if (!ts)
return;
trans->status = Disconnected;
if (ts->rd)
fput(ts->rd);
if (ts->wr)
fput(ts->wr);
kfree(ts);
}
struct v9fs_transport v9fs_trans_fd = {
.init = v9fs_fd_init,
.write = v9fs_fd_write,
.read = v9fs_fd_read,
.close = v9fs_fd_close,
.poll = v9fs_fd_poll,
};
struct v9fs_transport v9fs_trans_tcp = {
.init = v9fs_tcp_init,
.write = v9fs_fd_write,
.read = v9fs_fd_read,
.close = v9fs_fd_close,
.poll = v9fs_fd_poll,
};
struct v9fs_transport v9fs_trans_unix = {
.init = v9fs_unix_init,
.write = v9fs_fd_write,
.read = v9fs_fd_read,
.close = v9fs_fd_close,
.poll = v9fs_fd_poll,
};