text: /*
   * linux/fs/9p/trans_socket.c
   *
   * Socket Transport Layer
   *
   *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
   *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
   *  Copyright (C) 1995, 1996 by Olaf Kirch <okir@monad.swb.de>
   *
   *  This program 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 of the License, or
   *  (at your option) any later version.
   *
   *  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/config.h>
  #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_sock {
  	struct socket *s;
  	struct file *filp;
  };
  
  /**
   * v9fs_sock_recv - receive from a socket
   * @v9ses: session information
   * @v: buffer to receive data into
   * @len: size of receive buffer
   *
   */
  
  static int v9fs_sock_recv(struct v9fs_transport *trans, void *v, int len)
  {
  	int ret;
  	struct v9fs_trans_sock *ts;
  
  	if (!trans || trans->status == Disconnected) {
  		dprintk(DEBUG_ERROR, "disconnected ...\n");
  		return -EREMOTEIO;
  	}
  
  	ts = trans->priv;
  
  	if (!(ts->filp->f_flags & O_NONBLOCK))
  		dprintk(DEBUG_ERROR, "blocking read ...\n");
  
  	ret = kernel_read(ts->filp, ts->filp->f_pos, v, len);
  	if (ret <= 0) {
  		if (ret != -ERESTARTSYS && ret != -EAGAIN)
  			trans->status = Disconnected;
  	}
  
  	return ret;
  }
  
  /**
   * v9fs_sock_send - send to a socket
   * @v9ses: session information
   * @v: buffer to send data from
   * @len: size of send buffer
   *
   */
  
  static int v9fs_sock_send(struct v9fs_transport *trans, void *v, int len)
  {
  	int ret;
  	mm_segment_t oldfs;
  	struct v9fs_trans_sock *ts;
  
  	if (!trans || trans->status == Disconnected) {
  		dprintk(DEBUG_ERROR, "disconnected ...\n");
  		return -EREMOTEIO;
  	}
  
  	ts = trans->priv;
  	if (!ts) {
  		dprintk(DEBUG_ERROR, "no transport ...\n");
  		return -EREMOTEIO;
  	}
  
  	if (!(ts->filp->f_flags & O_NONBLOCK))
  		dprintk(DEBUG_ERROR, "blocking write ...\n");
  
  	oldfs = get_fs();
  	set_fs(get_ds());
  	ret = vfs_write(ts->filp, (void __user *)v, len, &ts->filp->f_pos);
  	set_fs(oldfs);
  
  	if (ret < 0) {
  		if (ret != -ERESTARTSYS)
  			trans->status = Disconnected;
  	}
  
  	return ret;
  }
  
  static unsigned int v9fs_sock_poll(struct v9fs_transport *trans,
  	struct poll_table_struct *pt) {
  
  	int ret;
  	struct v9fs_trans_sock *ts;
  	mm_segment_t oldfs;
  
  	if (!trans) {
  		dprintk(DEBUG_ERROR, "no transport\n");
  		return -EIO;
  	}
  
  	ts = trans->priv;
  	if (trans->status != Connected || !ts) {
  		dprintk(DEBUG_ERROR, "transport disconnected: %d\n", trans->status);
  		return -EIO;
  	}
  
  	oldfs = get_fs();
  	set_fs(get_ds());
  
  	if (!ts->filp->f_op || !ts->filp->f_op->poll) {
  		dprintk(DEBUG_ERROR, "no poll operation\n");
  		ret = -EIO;
  		goto end;
  	}
  
  	ret = ts->filp->f_op->poll(ts->filp, pt);
  
  end:
  	set_fs(oldfs);
  	return ret;
  }
  
  
  /**
   * v9fs_tcp_init - initialize TCP socket
   * @v9ses: session information
   * @addr: address of server to mount
   * @data: mount options
   *
   */
  
  static int
  v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
  {
  	struct socket *csocket = NULL;
  	struct sockaddr_in sin_server;
  	int rc = 0;
  	struct v9fs_trans_sock *ts = NULL;
  	struct v9fs_transport *trans = v9ses->transport;
  	int fd;
  
  	trans->status = Disconnected;
  
  	ts = kmalloc(sizeof(struct v9fs_trans_sock), GFP_KERNEL);
  
  	if (!ts)
  		return -ENOMEM;
  
  	trans->priv = ts;
  	ts->s = NULL;
  	ts->filp = NULL;
  
  	if (!addr)
  		return -EINVAL;
  
  	dprintk(DEBUG_TRANS, "Connecting to %s\n", addr);
  
  	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);
  	rc = csocket->ops->connect(csocket,
  				   (struct sockaddr *)&sin_server,
  				   sizeof(struct sockaddr_in), 0);
  	if (rc < 0) {
  		eprintk(KERN_ERR,
  			"v9fs_trans_tcp: problem connecting socket to %s\n",
  			addr);
  		return rc;
  	}
  	csocket->sk->sk_allocation = GFP_NOIO;
  
  	fd = sock_map_fd(csocket);
  	if (fd < 0) {
  		sock_release(csocket);
  		kfree(ts);
  		trans->priv = NULL;
  		return fd;
  	}
  
  	ts->s = csocket;
  	ts->filp = fget(fd);
  	ts->filp->f_flags |= O_NONBLOCK;
  	trans->status = Connected;
  
  	return 0;
  }
  
  /**
   * v9fs_unix_init - initialize UNIX domain socket
   * @v9ses: session information
   * @dev_name: path to named pipe
   * @data: mount options
   *
   */
  
  static int
  v9fs_unix_init(struct v9fs_session_info *v9ses, const char *dev_name,
  	       char *data)
  {
  	int rc, fd;
  	struct socket *csocket;
  	struct sockaddr_un sun_server;
  	struct v9fs_transport *trans;
  	struct v9fs_trans_sock *ts;
  
  	rc = 0;
  	csocket = NULL;
  	trans = v9ses->transport;
  
  	trans->status = Disconnected;
  
  	if (strlen(dev_name) > UNIX_PATH_MAX) {
  		eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
  			dev_name);
  		return -ENOMEM;
  	}
  
  	ts = kmalloc(sizeof(struct v9fs_trans_sock), GFP_KERNEL);
  	if (!ts)
  		return -ENOMEM;
  
  	trans->priv = ts;
  	ts->s = NULL;
  	ts->filp = NULL;
  
  	sun_server.sun_family = PF_UNIX;
  	strcpy(sun_server.sun_path, dev_name);
  	sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
  	rc = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
  		sizeof(struct sockaddr_un) - 1, 0);	/* -1 *is* important */
  	if (rc < 0) {
  		eprintk(KERN_ERR,
  			"v9fs_trans_unix: problem connecting socket: %s: %d\n",
  			dev_name, rc);
  		return rc;
  	}
  	csocket->sk->sk_allocation = GFP_NOIO;
  
  	fd = sock_map_fd(csocket);
  	if (fd < 0) {
  		sock_release(csocket);
  		kfree(ts);
  		trans->priv = NULL;
  		return fd;
  	}
  
  	ts->s = csocket;
  	ts->filp = fget(fd);
  	ts->filp->f_flags |= O_NONBLOCK;
  	trans->status = Connected;
  
  	return 0;
  }
  
  /**
   * v9fs_sock_close - shutdown socket
   * @trans: private socket structure
   *
   */
  
  static void v9fs_sock_close(struct v9fs_transport *trans)
  {
  	struct v9fs_trans_sock *ts;
  
  	if (!trans)
  		return;
  
  	ts = trans->priv;
  
  	if ((ts) && (ts->filp)) {
  		fput(ts->filp);
  		ts->filp = NULL;
  		ts->s = NULL;
  		trans->status = Disconnected;
  	}
  
  	kfree(ts);
  
  	trans->priv = NULL;
  }
  
  struct v9fs_transport v9fs_trans_tcp = {
  	.init = v9fs_tcp_init,
  	.write = v9fs_sock_send,
  	.read = v9fs_sock_recv,
  	.close = v9fs_sock_close,
  	.poll = v9fs_sock_poll,
  };
  
  struct v9fs_transport v9fs_trans_unix = {
  	.init = v9fs_unix_init,
  	.write = v9fs_sock_send,
  	.read = v9fs_sock_recv,
  	.close = v9fs_sock_close,
  	.poll = v9fs_sock_poll,
  };
  