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apache / nuttx / aa8fb9ae2e9d22ae71976db5e3d82b55a25b8c1b / . / net / can / can_recvmsg.c
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/****************************************************************************
* net/can/can_recvmsg.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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>
#ifdef CONFIG_NET_CAN
#include <sys/types.h>
#include <sys/socket.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <assert.h>
#include <arch/irq.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "can/can.h"
#include "socket/socket.h"
#include <netpacket/packet.h>
#ifdef CONFIG_NET_TIMESTAMP
#include <sys/time.h>
#include <utils/utils.h>
#endif
/****************************************************************************
* Private Types
****************************************************************************/
struct can_recvfrom_s
{
FAR struct can_conn_s *pr_conn; /* Connection associated with the socket */
FAR struct devif_callback_s *pr_cb; /* Reference to callback instance */
sem_t pr_sem; /* Semaphore signals recv completion */
size_t pr_buflen; /* Length of receive buffer */
FAR uint8_t *pr_buffer; /* Pointer to receive buffer */
ssize_t pr_recvlen; /* The received length */
size_t pr_msglen; /* Length of msg buffer */
FAR uint8_t *pr_msgbuf; /* Pointer to msg buffer */
int pr_result; /* Success:OK, failure:negated errno */
};
/****************************************************************************
* Private Functions
****************************************************************************/
#ifdef CONFIG_NET_CANPROTO_OPTIONS
static int can_recv_filter(FAR struct can_conn_s *conn, canid_t id);
#endif
/****************************************************************************
* Name: can_add_recvlen
*
* Description:
* Update information about space available for new data and update size
* of data in buffer, This logic accounts for the case where
* recvfrom_udpreadahead() sets state.pr_recvlen == -1 .
*
* Input Parameters:
* pstate recvfrom state structure
* recvlen size of new data appended to buffer
*
* Returned Value:
* None
*
****************************************************************************/
static inline void can_add_recvlen(FAR struct can_recvfrom_s *pstate,
size_t recvlen)
{
if (pstate->pr_recvlen < 0)
{
pstate->pr_recvlen = 0;
}
pstate->pr_recvlen += recvlen;
pstate->pr_buffer += recvlen;
pstate->pr_buflen -= recvlen;
}
/****************************************************************************
* Name: can_recvfrom_newdata
*
* Description:
* Copy the read data from the packet
*
* Input Parameters:
* dev The structure of the network driver that caused the event.
* pstate recvfrom state structure
*
* Returned Value:
* None.
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static size_t can_recvfrom_newdata(FAR struct net_driver_s *dev,
FAR struct can_recvfrom_s *pstate)
{
unsigned int offset;
size_t recvlen;
#ifdef CONFIG_NET_TIMESTAMP
FAR struct can_conn_s *conn = pstate->pr_conn;
if (_SO_GETOPT(conn->sconn.s_options, SO_TIMESTAMP) &&
pstate->pr_msglen == sizeof(struct timeval))
{
iob_copyout(pstate->pr_msgbuf, dev->d_iob, sizeof(struct timeval),
-CONFIG_NET_LL_GUARDSIZE);
}
#endif
if (dev->d_len > pstate->pr_buflen)
{
recvlen = pstate->pr_buflen;
}
else
{
recvlen = dev->d_len;
}
/* Copy the new packet data into the user buffer */
offset = (dev->d_appdata - dev->d_iob->io_data) - dev->d_iob->io_offset;
recvlen = iob_copyout(pstate->pr_buffer, dev->d_iob, recvlen, offset);
/* Trim the copied buffers */
dev->d_iob = iob_trimhead(dev->d_iob, recvlen + offset);
/* Update the accumulated size of the data read */
can_add_recvlen(pstate, recvlen);
return recvlen;
}
/****************************************************************************
* Name: can_newdata
*
* Description:
* Copy the read data from the packet
*
* Input Parameters:
* dev The structure of the network driver that generated the event
* pstate recvfrom state structure
*
* Returned Value:
* None.
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static inline void can_newdata(FAR struct net_driver_s *dev,
FAR struct can_recvfrom_s *pstate)
{
/* Take as much data from the packet as we can */
size_t recvlen = can_recvfrom_newdata(dev, pstate);
/* If there is more data left in the packet that we could not buffer, then
* add it to the read-ahead buffers.
*/
if (recvlen < dev->d_len)
{
if (can_datahandler(dev, pstate->pr_conn) < dev->d_len)
{
ninfo("Dropped %d bytes\n", dev->d_len);
#ifdef CONFIG_NET_STATISTICS
g_netstats.can.drop++;
#endif
}
}
/* Indicate no data in the buffer */
dev->d_len = 0;
}
/****************************************************************************
* Name: can_readahead
*
* Description:
* Copy the read-ahead data from the packet
*
* Input Parameters:
* pstate recvfrom state structure
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static inline int can_readahead(struct can_recvfrom_s *pstate)
{
FAR struct can_conn_s *conn = pstate->pr_conn;
FAR struct iob_s *iob;
int recvlen;
/* Check there is any CAN data already buffered in a read-ahead
* buffer.
*/
pstate->pr_recvlen = -1;
if (pstate->pr_buflen > 0 &&
(iob = iob_remove_queue(&conn->readahead)) != NULL)
{
DEBUGASSERT(iob->io_pktlen > 0);
#ifdef CONFIG_NET_CANPROTO_OPTIONS
/* Check receive filters */
canid_t can_id;
iob_copyout((uint8_t *)&can_id, iob, sizeof(canid_t), 0);
if (can_recv_filter(conn, can_id) == 0)
{
/* Free the I/O buffer chain */
iob_free_chain(iob);
return 0;
}
#endif
#ifdef CONFIG_NET_TIMESTAMP
if (_SO_GETOPT(conn->sconn.s_options, SO_TIMESTAMP) &&
pstate->pr_msglen == sizeof(struct timeval))
{
iob_copyout(pstate->pr_msgbuf, iob, sizeof(struct timeval),
-CONFIG_NET_LL_GUARDSIZE);
}
#endif
/* Transfer that buffered data from the I/O buffer chain into
* the user buffer.
*/
recvlen = iob_copyout(pstate->pr_buffer, iob, pstate->pr_buflen, 0);
/* We should have taken all of the data from the I/O buffer chain,
* so release it. There is no trimming needed, since One CAN/CANFD
* frame can always fit in one IOB.
*/
static_assert(sizeof(struct can_frame) <= CONFIG_IOB_BUFSIZE);
/* Free the I/O buffer chain */
iob_free_chain(iob);
/* do not pass frames with DLC > 8 to a legacy socket */
#if defined(CONFIG_NET_CANPROTO_OPTIONS) && defined(CONFIG_NET_CAN_CANFD)
if (!_SO_GETOPT(conn->sconn.s_options, CAN_RAW_FD_FRAMES))
#endif
{
if (recvlen > sizeof(struct can_frame))
{
return 0;
}
}
return recvlen;
}
return 0;
}
#ifdef CONFIG_NET_CANPROTO_OPTIONS
static int can_recv_filter(FAR struct can_conn_s *conn, canid_t id)
{
uint32_t i;
#ifdef CONFIG_NET_CAN_ERRORS
/* error message frame */
if ((id & CAN_ERR_FLAG) != 0)
{
return id & conn->err_mask ? 1 : 0;
}
#endif
for (i = 0; i < conn->filter_count; i++)
{
if (conn->filters[i].can_id & CAN_INV_FILTER)
{
if ((id & conn->filters[i].can_mask) !=
((conn->filters[i].can_id & ~CAN_INV_FILTER) &
conn->filters[i].can_mask))
{
return 1;
}
}
else
{
if ((id & conn->filters[i].can_mask) ==
(conn->filters[i].can_id & conn->filters[i].can_mask))
{
return 1;
}
}
}
return 0;
}
#endif
static uint16_t can_recvfrom_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
struct can_recvfrom_s *pstate = pvpriv;
/* 'priv' might be null in some race conditions (?) */
if (pstate)
{
#if defined(CONFIG_NET_CANPROTO_OPTIONS) || defined(CONFIG_NET_TIMESTAMP)
struct can_conn_s *conn = pstate->pr_conn;
#endif
if ((flags & CAN_NEWDATA) != 0)
{
/* If a new packet is available, check receive filters
* when is valid then complete the read action.
*/
#ifdef CONFIG_NET_CANPROTO_OPTIONS
canid_t can_id;
memcpy(&can_id, dev->d_appdata, sizeof(canid_t));
if (can_recv_filter(conn, can_id) == 0)
{
flags &= ~CAN_NEWDATA;
return flags;
}
#endif
/* do not pass frames with DLC > 8 to a legacy socket */
#if defined(CONFIG_NET_CANPROTO_OPTIONS) && defined(CONFIG_NET_CAN_CANFD)
if (!_SO_GETOPT(conn->sconn.s_options, CAN_RAW_FD_FRAMES))
#endif
{
#ifdef CONFIG_NET_TIMESTAMP
if ((_SO_GETOPT(conn->sconn.s_options, SO_TIMESTAMP) &&
dev->d_len > sizeof(struct can_frame) +
sizeof(struct timeval)) ||
(!_SO_GETOPT(conn->sconn.s_options, SO_TIMESTAMP) &&
dev->d_len > sizeof(struct can_frame)))
#else
if (dev->d_len > sizeof(struct can_frame))
#endif
{
/* DO WE NEED TO CLEAR FLAGS?? */
flags &= ~CAN_NEWDATA;
return flags;
}
}
/* Copy the packet */
can_newdata(dev, pstate);
/* We are finished. */
/* Don't allow any further call backs. */
pstate->pr_cb->flags = 0;
pstate->pr_cb->priv = NULL;
pstate->pr_cb->event = NULL;
/* indicate that the data has been consumed */
flags &= ~CAN_NEWDATA;
/* Wake up the waiting thread, returning the number of bytes
* actually read.
*/
nxsem_post(&pstate->pr_sem);
}
}
return flags;
}
/****************************************************************************
* Name: can_recvfrom_result
*
* Description:
* Evaluate the result of the recv operations
*
* Input Parameters:
* result The result of the net_sem_wait operation (may indicate EINTR)
* pstate A pointer to the state structure to be initialized
*
* Returned Value:
* The result of the recv operation with errno set appropriately
*
* Assumptions:
*
****************************************************************************/
static ssize_t can_recvfrom_result(int result,
FAR struct can_recvfrom_s *pstate)
{
/* Check for a error/timeout detected by the event handler. Errors are
* signaled by negative errno values for the rcv length
*/
if (pstate->pr_result < 0)
{
/* This might return EAGAIN on a timeout */
return pstate->pr_result;
}
/* 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 (result < 0)
{
return result;
}
return pstate->pr_recvlen;
}
/****************************************************************************
* Name: can_recvmsg
*
* Description:
* recvmsg() receives messages from a socket, and may be used to receive
* data on a socket whether or not it is connection-oriented.
*
* If from is not NULL, and the underlying protocol provides the source
* address, this source address is filled in. The argument 'msg_namelen'
* initialized to the size of the buffer associated with from, and modified
* on return to indicate the actual size of the address stored there.
*
* Input Parameters:
* psock A pointer to a NuttX-specific, internal socket structure
* msg Buffer to receive the message
* flags Receive flags (ignored)
*
****************************************************************************/
ssize_t can_recvmsg(FAR struct socket *psock, FAR struct msghdr *msg,
int flags)
{
FAR struct can_conn_s *conn;
FAR struct net_driver_s *dev;
struct can_recvfrom_s state;
int ret;
conn = psock->s_conn;
if (psock->s_type != SOCK_RAW)
{
nerr("ERROR: Unsupported socket type: %d\n", psock->s_type);
return -ENOSYS;
}
if (msg->msg_iovlen != 1)
{
return -ENOTSUP;
}
net_lock();
/* Initialize the state structure. */
memset(&state, 0, sizeof(struct can_recvfrom_s));
nxsem_init(&state.pr_sem, 0, 0); /* Doesn't really fail */
state.pr_buflen = msg->msg_iov->iov_len;
state.pr_buffer = msg->msg_iov->iov_base;
#ifdef CONFIG_NET_TIMESTAMP
if (_SO_GETOPT(conn->sconn.s_options, SO_TIMESTAMP))
{
state.pr_msgbuf = cmsg_append(msg, SOL_SOCKET, SO_TIMESTAMP,
NULL, sizeof(struct timeval));
if (state.pr_msgbuf != NULL)
{
state.pr_msglen = sizeof(struct timeval);
}
}
#endif
state.pr_conn = conn;
/* Handle any any CAN data already buffered in a read-ahead buffer. NOTE
* that there may be read-ahead data to be retrieved even after the
* socket has been disconnected.
*/
ret = can_readahead(&state);
if (ret > 0)
{
goto errout_with_state;
}
ret = state.pr_recvlen;
/* Handle non-blocking CAN sockets */
if (_SS_ISNONBLOCK(conn->sconn.s_flags) || (flags & MSG_DONTWAIT) != 0)
{
/* Return the number of bytes read from the read-ahead buffer if
* something was received (already in 'ret'); EAGAIN if not.
*/
if (ret < 0)
{
/* Nothing was received */
ret = -EAGAIN;
goto errout_with_state;
}
}
/* Get the device driver that will service this transfer */
dev = conn->dev;
if (dev == NULL)
{
ret = -ENODEV;
goto errout_with_state;
}
/* Set up the callback in the connection */
state.pr_cb = can_callback_alloc(dev, conn);
if (state.pr_cb)
{
state.pr_cb->flags = (CAN_NEWDATA | CAN_POLL);
state.pr_cb->priv = (FAR void *)&state;
state.pr_cb->event = can_recvfrom_eventhandler;
/* Wait for either the receive to complete or for an error/timeout to
* occur. NOTES: (1) net_sem_wait will also terminate if a signal
* is received, (2) the network is locked! It will be un-locked while
* the task sleeps and automatically re-locked when the task restarts.
*/
ret = net_sem_wait(&state.pr_sem);
/* Make sure that no further events are processed */
can_callback_free(dev, conn, state.pr_cb);
ret = can_recvfrom_result(ret, &state);
}
else
{
ret = -EBUSY;
}
errout_with_state:
net_unlock();
nxsem_destroy(&state.pr_sem);
return ret;
}
#endif /* CONFIG_NET_CAN */