/****************************************************************************
* net/can/can_sendmsg.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) && defined(CONFIG_NET_CAN)
#include <sys/types.h>
#include <sys/socket.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <arch/irq.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/net.h>
#include <nuttx/net/ip.h>
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "socket/socket.h"
#include "can/can.h"
#include <sys/time.h>
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure holds the state of the send operation until it can be
* operated upon by the event handler.
*/
struct send_s
{
FAR struct devif_callback_s *snd_cb; /* Reference to callback instance */
sem_t snd_sem; /* Used to wake up the waiting thread */
FAR const uint8_t *snd_buffer; /* Points to the buffer of data to send */
size_t snd_buflen; /* Number of bytes in the buffer to send */
size_t pr_msglen; /* Length of msg buffer */
FAR uint8_t *pr_msgbuf; /* Pointer to msg buffer */
ssize_t snd_sent; /* The number of bytes sent */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: psock_send_eventhandler
****************************************************************************/
static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
FAR struct send_s *pstate = pvpriv;
if (pstate)
{
/* Check if the outgoing packet is available. It may have been claimed
* by a send event handler serving a different thread -OR- if the
* output buffer currently contains unprocessed incoming data. In
* these cases we will just have to wait for the next polling cycle.
*/
if (dev->d_sndlen > 0 || (flags & CAN_NEWDATA) != 0)
{
/* Another thread has beat us sending data or the buffer is busy,
* Check for a timeout. If not timed out, wait for the next
* polling cycle and check again.
*/
/* No timeout. Just wait for the next polling cycle */
return flags;
}
/* It looks like we are good to send the data */
else
{
/* Copy the packet data into the device packet buffer and send it */
int ret = devif_send(dev, pstate->snd_buffer,
pstate->snd_buflen, 0);
dev->d_len = dev->d_sndlen;
if (ret <= 0)
{
pstate->snd_sent = ret;
goto end_wait;
}
pstate->snd_sent = pstate->snd_buflen;
if (pstate->pr_msglen > 0) /* concat cmsg data after packet */
{
memcpy(dev->d_buf + pstate->snd_buflen, pstate->pr_msgbuf,
pstate->pr_msglen);
dev->d_sndlen = pstate->snd_buflen + pstate->pr_msglen;
}
}
end_wait:
/* Don't allow any further call backs. */
pstate->snd_cb->flags = 0;
pstate->snd_cb->priv = NULL;
pstate->snd_cb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->snd_sem);
}
return flags;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: can_sendmsg
*
* Description:
* The can_sendmsg() call may be used only when the packet socket is
* in a connected state (so that the intended recipient is known).
*
* Input Parameters:
* psock An instance of the internal socket structure.
* msg CAN frame and optional CMSG
* flags Send flags (ignored)
*
* Returned Value:
* On success, returns the number of characters sent. On error,
* a negated errno value is retruend. See sendmsg() for the complete list
* of return values.
*
****************************************************************************/
ssize_t can_sendmsg(FAR struct socket *psock, FAR struct msghdr *msg,
int flags)
{
FAR struct net_driver_s *dev;
FAR struct can_conn_s *conn;
struct send_s state;
int ret = OK;
/* Verify that the sockfd corresponds to valid, allocated socket */
if (psock == NULL || psock->s_conn == NULL)
{
return -EBADF;
}
/* Only SOCK_RAW is supported */
if (psock->s_type != SOCK_RAW)
{
/* EDESTADDRREQ. Signifies that the socket is not connection-mode and
* no peer address is set.
*/
return -EDESTADDRREQ;
}
conn = psock->s_conn;
/* Get the device driver that will service this transfer */
dev = conn->dev;
if (dev == NULL)
{
return -ENODEV;
}
#if defined(CONFIG_NET_CANPROTO_OPTIONS) && defined(CONFIG_NET_CAN_CANFD)
if (conn->fd_frames)
{
if (msg->msg_iov->iov_len != CANFD_MTU &&
msg->msg_iov->iov_len != CAN_MTU)
{
return -EINVAL;
}
}
else
#endif
{
if (msg->msg_iov->iov_len != CAN_MTU)
{
return -EINVAL;
}
}
/* Perform the send operation */
/* Initialize the state structure. This is done with the network locked
* because we don't want anything to happen until we are ready.
*/
net_lock();
memset(&state, 0, sizeof(struct send_s));
nxsem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */
state.snd_buflen = msg->msg_iov->iov_len; /* bytes to send */
state.snd_buffer = msg->msg_iov->iov_base; /* Buffer to send from */
#ifdef CONFIG_NET_CAN_RAW_TX_DEADLINE
if (msg->msg_controllen > sizeof(struct cmsghdr))
{
FAR struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
if (conn->tx_deadline &&
cmsg->cmsg_level == SOL_CAN_RAW &&
cmsg->cmsg_type == CAN_RAW_TX_DEADLINE &&
cmsg->cmsg_len == sizeof(struct timeval))
{
state.pr_msgbuf = CMSG_DATA(cmsg); /* Buffer to cmsg data */
state.pr_msglen = cmsg->cmsg_len; /* len of cmsg data */
}
}
#endif
/* Allocate resource to receive a callback */
state.snd_cb = can_callback_alloc(dev, conn);
if (state.snd_cb)
{
/* Set up the callback in the connection */
state.snd_cb->flags = CAN_POLL;
state.snd_cb->priv = (FAR void *)&state;
state.snd_cb->event = psock_send_eventhandler;
/* Notify the device driver that new TX data is available. */
netdev_txnotify_dev(dev);
/* Wait for the send to complete or an error to occur.
* net_sem_timedwait will also terminate if a signal is received.
*/
if (_SS_ISNONBLOCK(conn->sconn.s_flags) || (flags & MSG_DONTWAIT) != 0)
{
ret = net_sem_timedwait(&state.snd_sem, 0);
}
else
{
ret = net_sem_timedwait(&state.snd_sem, UINT_MAX);
}
/* Make sure that no further events are processed */
can_callback_free(dev, conn, state.snd_cb);
}
nxsem_destroy(&state.snd_sem);
net_unlock();
/* Check for a errors, Errors are signalled by negative errno values
* for the send length
*/
if (state.snd_sent < 0)
{
return state.snd_sent;
}
/* If net_sem_wait failed, then we were probably reawakened by a signal.
* In this case, net_sem_wait will have returned negated errno
* appropriately.
*/
if (ret < 0)
{
return ret;
}
/* Return the number of bytes actually sent */
return state.snd_sent;
}
/****************************************************************************
* Name: psock_can_cansend
*
* Description:
* psock_can_cansend() returns a value indicating if a write to the socket
* would block. No space in the buffer is actually reserved, so it is
* possible that the write may still block if the buffer is filled by
* another means.
*
* Input Parameters:
* psock An instance of the internal socket structure.
*
* Returned Value:
* OK
* At least one byte of data could be successfully written.
* -EWOULDBLOCK
* There is no room in the output buffer.
* -EBADF
* An invalid descriptor was specified.
*
****************************************************************************/
int psock_can_cansend(FAR struct socket *psock)
{
/* Verify that we received a valid socket */
if (psock == NULL || psock->s_conn == NULL)
{
nerr("ERROR: Invalid socket\n");
return -EBADF;
}
/* TODO Query CAN driver mailboxes to see if there's mailbox available */
return OK;
}
#endif /* CONFIG_NET && CONFIG_NET_CAN */