incubator-nuttx/net/icmp/icmp_netpoll.c

290 lines
7.3 KiB
C

/****************************************************************************
* net/icmp/icmp_netpoll.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>
#include <stdint.h>
#include <poll.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/net.h>
#include "devif/devif.h"
#include "netdev/netdev.h"
#include "icmp/icmp.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_poll_eventhandler
*
* Description:
* This function is called to perform the actual UDP receive operation
* via the device interface layer.
*
* Input Parameters:
* dev The structure of the network driver that caused the event
* pvpriv An instance of struct icmp_poll_s cast to void*
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* None
*
* Assumptions:
* This function must be called with the network locked.
*
****************************************************************************/
static uint16_t icmp_poll_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
FAR struct icmp_poll_s *info = pvpriv;
FAR struct icmp_conn_s *conn;
FAR struct socket *psock;
pollevent_t eventset;
ninfo("flags: %04x\n", flags);
DEBUGASSERT(info == NULL || info->fds != NULL);
/* 'priv' might be null in some race conditions (?). Only process the
* the event if this poll is from the same device that the request was
* sent out on.
*/
if (info != NULL)
{
/* Is this a response on the same device that we sent the request out
* on?
*/
psock = info->psock;
conn = psock->s_conn;
if (dev != conn->dev)
{
ninfo("Wrong device\n");
return flags;
}
/* Check for data or connection availability events. */
eventset = 0;
if ((flags & ICMP_NEWDATA) != 0)
{
eventset |= POLLIN;
}
/* Check for loss of connection events. */
if ((flags & NETDEV_DOWN) != 0)
{
eventset |= (POLLHUP | POLLERR);
}
/* Awaken the caller of poll() is requested event occurred. */
poll_notify(&info->fds, 1, eventset);
}
return flags;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_pollsetup
*
* Description:
* Setup to monitor events on one ICMP socket
*
* Input Parameters:
* psock - The IPPROTO_ICMP socket of interest
* fds - The structure describing the events to be monitored, OR NULL if
* this is a request to stop monitoring events.
*
* Returned Value:
* 0: Success; Negated errno on failure
*
****************************************************************************/
int icmp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds)
{
FAR struct icmp_conn_s *conn;
FAR struct icmp_poll_s *info;
FAR struct devif_callback_s *cb;
pollevent_t eventset = 0;
int ret = OK;
/* Some of the following must be atomic */
net_lock();
conn = psock->s_conn;
/* Sanity check */
if (!conn || !fds)
{
ret = -EINVAL;
goto errout_with_lock;
}
/* Find a container to hold the poll information */
info = conn->pollinfo;
while (info->psock != NULL)
{
if (++info >= &conn->pollinfo[CONFIG_NET_ICMP_NPOLLWAITERS])
{
ret = -ENOMEM;
goto errout_with_lock;
}
}
/* Allocate a ICMP callback structure */
cb = icmp_callback_alloc(conn->dev, conn);
if (cb == NULL)
{
ret = -EBUSY;
goto errout_with_lock;
}
/* Initialize the poll info container */
info->psock = psock;
info->dev = conn->dev;
info->fds = fds;
info->cb = cb;
/* Initialize the callback structure. Save the reference to the info
* structure as callback private data so that it will be available during
* callback processing.
*/
cb->flags = NETDEV_DOWN;
cb->priv = info;
cb->event = icmp_poll_eventhandler;
if ((fds->events & POLLIN) != 0)
{
cb->flags |= ICMP_NEWDATA;
}
/* Save the reference in the poll info structure as fds private as well
* for use during poll teardown as well.
*/
fds->priv = info;
/* Check for read data availability now */
if (!IOB_QEMPTY(&conn->readahead))
{
/* Normal data may be read without blocking. */
eventset |= POLLRDNORM;
}
/* Always report POLLWRNORM if caller request it because we don't utilize
* IOB buffer for sending.
*/
eventset |= POLLWRNORM;
/* Check if any requested events are already in effect */
poll_notify(&fds, 1, eventset);
errout_with_lock:
net_unlock();
return ret;
}
/****************************************************************************
* Name: icmp_pollteardown
*
* Description:
* Teardown monitoring of events on an ICMP socket
*
* Input Parameters:
* psock - The IPPROTO_ICMP socket of interest
* fds - The structure describing the events to be monitored, OR NULL if
* this is a request to stop monitoring events.
*
* Returned Value:
* 0: Success; Negated errno on failure
*
****************************************************************************/
int icmp_pollteardown(FAR struct socket *psock, FAR struct pollfd *fds)
{
FAR struct icmp_conn_s *conn;
FAR struct icmp_poll_s *info;
/* Some of the following must be atomic */
net_lock();
conn = psock->s_conn;
/* Sanity check */
if (!conn || !fds->priv)
{
net_unlock();
return -EINVAL;
}
/* Recover the socket descriptor poll state info from the poll structure */
info = (FAR struct icmp_poll_s *)fds->priv;
DEBUGASSERT(info->fds != NULL && info->cb != NULL);
if (info != NULL)
{
/* Release the callback */
icmp_callback_free(info->dev, conn, info->cb);
/* Release the poll/select data slot */
info->fds->priv = NULL;
/* Then free the poll info container */
info->psock = NULL;
}
net_unlock();
return OK;
}