linux-sg2042/net/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 <linux/uaccess.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
#include <net/9p/9p.h>
#include <net/9p/transport.h>
#define P9_PORT 564
struct p9_trans_fd {
struct file *rd;
struct file *wr;
};
static int p9_socket_open(struct p9_transport *trans, struct socket *csocket);
static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd);
static int p9_fd_read(struct p9_transport *trans, void *v, int len);
static int p9_fd_write(struct p9_transport *trans, void *v, int len);
static unsigned int p9_fd_poll(struct p9_transport *trans,
struct poll_table_struct *pt);
static void p9_fd_close(struct p9_transport *trans);
struct p9_transport *p9_trans_create_tcp(const char *addr, int port)
{
int err;
struct p9_transport *trans;
struct socket *csocket;
struct sockaddr_in sin_server;
csocket = NULL;
trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
if (!trans)
return ERR_PTR(-ENOMEM);
trans->write = p9_fd_write;
trans->read = p9_fd_read;
trans->close = p9_fd_close;
trans->poll = p9_fd_poll;
sin_server.sin_family = AF_INET;
sin_server.sin_addr.s_addr = in_aton(addr);
sin_server.sin_port = htons(port);
sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
if (!csocket) {
P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
err = -EIO;
goto error;
}
err = csocket->ops->connect(csocket,
(struct sockaddr *)&sin_server,
sizeof(struct sockaddr_in), 0);
if (err < 0) {
P9_EPRINTK(KERN_ERR,
"p9_trans_tcp: problem connecting socket to %s\n",
addr);
goto error;
}
err = p9_socket_open(trans, csocket);
if (err < 0)
goto error;
return trans;
error:
if (csocket)
sock_release(csocket);
kfree(trans);
return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_trans_create_tcp);
struct p9_transport *p9_trans_create_unix(const char *addr)
{
int err;
struct socket *csocket;
struct sockaddr_un sun_server;
struct p9_transport *trans;
csocket = NULL;
trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
if (!trans)
return ERR_PTR(-ENOMEM);
trans->write = p9_fd_write;
trans->read = p9_fd_read;
trans->close = p9_fd_close;
trans->poll = p9_fd_poll;
if (strlen(addr) > UNIX_PATH_MAX) {
P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
addr);
err = -ENAMETOOLONG;
goto error;
}
sun_server.sun_family = PF_UNIX;
strcpy(sun_server.sun_path, addr);
sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
sizeof(struct sockaddr_un) - 1, 0);
if (err < 0) {
P9_EPRINTK(KERN_ERR,
"p9_trans_unix: problem connecting socket: %s: %d\n",
addr, err);
goto error;
}
err = p9_socket_open(trans, csocket);
if (err < 0)
goto error;
return trans;
error:
if (csocket)
sock_release(csocket);
kfree(trans);
return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_trans_create_unix);
struct p9_transport *p9_trans_create_fd(int rfd, int wfd)
{
int err;
struct p9_transport *trans;
if (rfd == ~0 || wfd == ~0) {
printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
return ERR_PTR(-ENOPROTOOPT);
}
trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
if (!trans)
return ERR_PTR(-ENOMEM);
trans->write = p9_fd_write;
trans->read = p9_fd_read;
trans->close = p9_fd_close;
trans->poll = p9_fd_poll;
err = p9_fd_open(trans, rfd, wfd);
if (err < 0)
goto error;
return trans;
error:
kfree(trans);
return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_trans_create_fd);
static int p9_socket_open(struct p9_transport *trans, struct socket *csocket)
{
int fd, ret;
csocket->sk->sk_allocation = GFP_NOIO;
fd = sock_map_fd(csocket);
if (fd < 0) {
P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
return fd;
}
ret = p9_fd_open(trans, fd, fd);
if (ret < 0) {
P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
sockfd_put(csocket);
return ret;
}
((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;
return 0;
}
static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd)
{
struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_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;
}
/**
* p9_fd_read- read from a fd
* @v9ses: session information
* @v: buffer to receive data into
* @len: size of receive buffer
*
*/
static int p9_fd_read(struct p9_transport *trans, void *v, int len)
{
int ret;
struct p9_trans_fd *ts = NULL;
if (trans && trans->status != Disconnected)
ts = trans->priv;
if (!ts)
return -EREMOTEIO;
if (!(ts->rd->f_flags & O_NONBLOCK))
P9_DPRINTK(P9_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;
}
/**
* p9_fd_write - write to a socket
* @v9ses: session information
* @v: buffer to send data from
* @len: size of send buffer
*
*/
static int p9_fd_write(struct p9_transport *trans, void *v, int len)
{
int ret;
mm_segment_t oldfs;
struct p9_trans_fd *ts = NULL;
if (trans && trans->status != Disconnected)
ts = trans->priv;
if (!ts)
return -EREMOTEIO;
if (!(ts->wr->f_flags & O_NONBLOCK))
P9_DPRINTK(P9_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
p9_fd_poll(struct p9_transport *trans, struct poll_table_struct *pt)
{
int ret, n;
struct p9_trans_fd *ts = NULL;
mm_segment_t oldfs;
if (trans && trans->status == Connected)
ts = trans->priv;
if (!ts)
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;
}
/**
* p9_sock_close - shutdown socket
* @trans: private socket structure
*
*/
static void p9_fd_close(struct p9_transport *trans)
{
struct p9_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);
}