/*
* 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) 2004-2008 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/kthread.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 <linux/parser.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include <linux/syscalls.h> /* killme */
#define P9_PORT 564
#define MAX_SOCK_BUF (64*1024)
#define MAXPOLLWADDR 2
/**
* struct p9_fd_opts - per-transport options
* @rfd: file descriptor for reading (trans=fd)
* @wfd: file descriptor for writing (trans=fd)
* @port: port to connect to (trans=tcp)
*
*/
struct p9_fd_opts {
int rfd;
int wfd;
u16 port;
};
/**
* struct p9_trans_fd - transport state
* @rd: reference to file to read from
* @wr: reference of file to write to
* @conn: connection state reference
*
*/
struct p9_trans_fd {
struct file *rd;
struct file *wr;
struct p9_conn *conn;
};
/*
* Option Parsing (code inspired by NFS code)
* - a little lazy - parse all fd-transport options
*/
enum {
/* Options that take integer arguments */
Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
};
static const match_table_t tokens = {
{Opt_port, "port=%u"},
{Opt_rfdno, "rfdno=%u"},
{Opt_wfdno, "wfdno=%u"},
{Opt_err, NULL},
};
enum {
Rworksched = 1, /* read work scheduled or running */
Rpending = 2, /* can read */
Wworksched = 4, /* write work scheduled or running */
Wpending = 8, /* can write */
};
struct p9_poll_wait {
struct p9_conn *conn;
wait_queue_t wait;
wait_queue_head_t *wait_addr;
};
/**
* struct p9_conn - fd mux connection state information
* @mux_list: list link for mux to manage multiple connections (?)
* @client: reference to client instance for this connection
* @err: error state
* @req_list: accounting for requests which have been sent
* @unsent_req_list: accounting for requests that haven't been sent
* @req: current request being processed (if any)
* @tmp_buf: temporary buffer to read in header
* @rsize: amount to read for current frame
* @rpos: read position in current frame
* @rbuf: current read buffer
* @wpos: write position for current frame
* @wsize: amount of data to write for current frame
* @wbuf: current write buffer
* @poll_pending_link: pending links to be polled per conn
* @poll_wait: array of wait_q's for various worker threads
* @pt: poll state
* @rq: current read work
* @wq: current write work
* @wsched: ????
*
*/
struct p9_conn {
struct list_head mux_list;
struct p9_client *client;
int err;
struct list_head req_list;
struct list_head unsent_req_list;
struct p9_req_t *req;
char tmp_buf[7];
int rsize;
int rpos;
char *rbuf;
int wpos;
int wsize;
char *wbuf;
struct list_head poll_pending_link;
struct p9_poll_wait poll_wait[MAXPOLLWADDR];
poll_table pt;
struct work_struct rq;
struct work_struct wq;
unsigned long wsched;
};
static DEFINE_SPINLOCK(p9_poll_lock);
static LIST_HEAD(p9_poll_pending_list);
static struct workqueue_struct *p9_mux_wq;
static struct task_struct *p9_poll_task;
static void p9_mux_poll_stop(struct p9_conn *m)
{
unsigned long flags;
int i;
for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
struct p9_poll_wait *pwait = &m->poll_wait[i];
if (pwait->wait_addr) {
remove_wait_queue(pwait->wait_addr, &pwait->wait);
pwait->wait_addr = NULL;
}
}
spin_lock_irqsave(&p9_poll_lock, flags);
list_del_init(&m->poll_pending_link);
spin_unlock_irqrestore(&p9_poll_lock, flags);
}
/**
* p9_conn_cancel - cancel all pending requests with error
* @m: mux data
* @err: error code
*
*/
static void