incubator-nuttx/drivers/usrsock/usrsock_dev.c

551 lines
13 KiB
C

/****************************************************************************
* drivers/usrsock/usrsock_dev.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET_USRSOCK_DEVICE)
#include <sys/types.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <poll.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <arch/irq.h>
#include <nuttx/random.h>
#include <nuttx/fs/fs.h>
#include <nuttx/mutex.h>
#include <nuttx/net/net.h>
#include <nuttx/net/usrsock.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_NET_USRSOCKDEV_NPOLLWAITERS
# define CONFIG_NET_USRSOCKDEV_NPOLLWAITERS 1
#endif
/****************************************************************************
* Private Types
****************************************************************************/
struct usrsockdev_s
{
mutex_t devlock; /* Lock for device node */
uint8_t ocount; /* The number of times the device has been opened */
struct
{
FAR const struct iovec *iov; /* Pending request buffers */
int iovcnt; /* Number of request buffers */
size_t pos; /* Reader position on request buffer */
} req;
FAR struct pollfd *pollfds[CONFIG_NET_USRSOCKDEV_NPOLLWAITERS];
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Character driver methods */
static ssize_t usrsockdev_read(FAR struct file *filep, FAR char *buffer,
size_t len);
static ssize_t usrsockdev_write(FAR struct file *filep,
FAR const char *buffer, size_t len);
static off_t usrsockdev_seek(FAR struct file *filep, off_t offset,
int whence);
static int usrsockdev_open(FAR struct file *filep);
static int usrsockdev_close(FAR struct file *filep);
static int usrsockdev_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_usrsockdevops =
{
usrsockdev_open, /* open */
usrsockdev_close, /* close */
usrsockdev_read, /* read */
usrsockdev_write, /* write */
usrsockdev_seek, /* seek */
NULL, /* ioctl */
NULL, /* mmap */
NULL, /* truncate */
usrsockdev_poll /* poll */
};
static struct usrsockdev_s g_usrsockdev =
{
NXMUTEX_INITIALIZER
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: usrsockdev_is_opened
****************************************************************************/
static bool usrsockdev_is_opened(FAR struct usrsockdev_s *dev)
{
bool ret = true;
if (dev->ocount == 0)
{
ret = false; /* No usrsock daemon running. */
}
return ret;
}
/****************************************************************************
* Name: usrsockdev_read
****************************************************************************/
static ssize_t usrsockdev_read(FAR struct file *filep, FAR char *buffer,
size_t len)
{
FAR struct inode *inode = filep->f_inode;
FAR struct usrsockdev_s *dev;
int ret;
if (len == 0)
{
return 0;
}
if (buffer == NULL)
{
return -EINVAL;
}
DEBUGASSERT(inode);
dev = inode->i_private;
DEBUGASSERT(dev);
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
/* Is request available? */
if (dev->req.iov)
{
ssize_t rlen;
/* Copy request to user-space. */
rlen = usrsock_iovec_get(buffer, len, dev->req.iov, dev->req.iovcnt,
dev->req.pos, NULL);
if (rlen < 0)
{
/* Tried reading beyond buffer. */
len = 0;
}
else
{
dev->req.pos += rlen;
len = rlen;
}
}
else
{
len = 0;
}
nxmutex_unlock(&dev->devlock);
return len;
}
/****************************************************************************
* Name: usrsockdev_seek
****************************************************************************/
static off_t usrsockdev_seek(FAR struct file *filep, off_t offset,
int whence)
{
FAR struct inode *inode = filep->f_inode;
FAR struct usrsockdev_s *dev;
off_t pos;
int ret;
if (whence != SEEK_CUR && whence != SEEK_SET)
{
return -EINVAL;
}
DEBUGASSERT(inode);
dev = inode->i_private;
DEBUGASSERT(dev);
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
/* Is request available? */
if (dev->req.iov)
{
ssize_t rlen;
if (whence == SEEK_CUR)
{
pos = dev->req.pos + offset;
}
else
{
pos = offset;
}
/* Copy request to user-space. */
rlen = usrsock_iovec_get(NULL, 0, dev->req.iov, dev->req.iovcnt,
pos, NULL);
if (rlen < 0)
{
/* Tried seek beyond buffer. */
pos = -EINVAL;
}
else
{
dev->req.pos = pos;
}
}
else
{
pos = 0;
}
nxmutex_unlock(&dev->devlock);
return pos;
}
/****************************************************************************
* Name: usrsockdev_write
****************************************************************************/
static ssize_t usrsockdev_write(FAR struct file *filep,
FAR const char *buffer, size_t len)
{
FAR struct inode *inode = filep->f_inode;
FAR struct usrsockdev_s *dev;
bool req_done = false;
ssize_t ret = 0;
if (len == 0)
{
return 0;
}
if (buffer == NULL)
{
return -EINVAL;
}
DEBUGASSERT(inode);
dev = inode->i_private;
DEBUGASSERT(dev);
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
ret = usrsock_response(buffer, len, &req_done);
if (req_done && dev->req.iov)
{
dev->req.iov = NULL;
dev->req.pos = 0;
dev->req.iovcnt = 0;
}
nxmutex_unlock(&dev->devlock);
return ret;
}
/****************************************************************************
* Name: usrsockdev_open
****************************************************************************/
static int usrsockdev_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct usrsockdev_s *dev;
int ret;
int tmp;
DEBUGASSERT(inode);
dev = inode->i_private;
DEBUGASSERT(dev);
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
ninfo("opening /dev/usrsock\n");
/* Increment the count of references to the device. */
tmp = dev->ocount + 1;
if (tmp > 1)
{
/* Only one reference is allowed. */
nwarn("failed to open\n");
ret = -EPERM;
}
else
{
dev->ocount = tmp;
ret = OK;
}
nxmutex_unlock(&dev->devlock);
return ret;
}
/****************************************************************************
* Name: usrsockdev_close
****************************************************************************/
static int usrsockdev_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct usrsockdev_s *dev;
int ret;
DEBUGASSERT(inode);
dev = inode->i_private;
DEBUGASSERT(dev);
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
ninfo("closing /dev/usrsock\n");
/* Decrement the references to the driver. */
dev->ocount--;
DEBUGASSERT(dev->ocount == 0);
ret = OK;
dev->req.iov = NULL;
dev->req.iovcnt = 0;
dev->req.pos = 0;
nxmutex_unlock(&dev->devlock);
usrsock_abort();
return ret;
}
/****************************************************************************
* Name: usrsockdev_poll
****************************************************************************/
static int usrsockdev_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup)
{
FAR struct inode *inode = filep->f_inode;
FAR struct usrsockdev_s *dev;
pollevent_t eventset;
int ret;
int i;
DEBUGASSERT(inode);
dev = inode->i_private;
DEBUGASSERT(dev);
/* Some sanity checking */
if (!dev || !fds)
{
return -ENODEV;
}
/* Are we setting up the poll? Or tearing it down? */
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
if (setup)
{
/* This is a request to set up the poll. Find an available
* slot for the poll structure reference
*/
for (i = 0; i < nitems(dev->pollfds); i++)
{
/* Find an available slot */
if (!dev->pollfds[i])
{
/* Bind the poll structure and this slot */
dev->pollfds[i] = fds;
fds->priv = &dev->pollfds[i];
break;
}
}
if (i >= nitems(dev->pollfds))
{
fds->priv = NULL;
ret = -EBUSY;
goto errout;
}
/* Should immediately notify on any of the requested events? */
eventset = 0;
/* Notify the POLLIN event if pending request. */
if (dev->req.iov != NULL &&
!(usrsock_iovec_get(NULL, 0, dev->req.iov,
dev->req.iovcnt, dev->req.pos, NULL) < 0))
{
eventset |= POLLIN;
}
poll_notify(dev->pollfds, nitems(dev->pollfds), eventset);
}
else
{
/* This is a request to tear down the poll. */
FAR struct pollfd **slot = (FAR struct pollfd **)fds->priv;
if (!slot)
{
ret = -EIO;
goto errout;
}
/* Remove all memory of the poll setup */
*slot = NULL;
fds->priv = NULL;
}
errout:
nxmutex_unlock(&dev->devlock);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: usrsock_request
****************************************************************************/
int usrsock_request(FAR struct iovec *iov, unsigned int iovcnt)
{
FAR struct usrsockdev_s *dev = &g_usrsockdev;
int ret = 0;
/* Set outstanding request for daemon to handle. */
net_mutex_lock(&dev->devlock);
if (usrsockdev_is_opened(dev))
{
DEBUGASSERT(dev->req.iov == NULL);
dev->req.iov = iov;
dev->req.pos = 0;
dev->req.iovcnt = iovcnt;
/* Notify daemon of new request. */
poll_notify(dev->pollfds, nitems(dev->pollfds), POLLIN);
}
else
{
ninfo("daemon abruptly closed /dev/usrsock.\n");
ret = -ENETDOWN;
}
nxmutex_unlock(&dev->devlock);
return ret;
}
/****************************************************************************
* Name: usrsock_register
*
* Description:
* Register /dev/usrsock
*
****************************************************************************/
void usrsock_register(void)
{
register_driver("/dev/usrsock", &g_usrsockdevops, 0666,
&g_usrsockdev);
}
#endif /* CONFIG_NET_USRSOCK_DEVICE */