/**************************************************************************** * net/can/can_callback.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 #if defined(CONFIG_NET) && defined(CONFIG_NET_CAN) #include #include #include #include #include #include "devif/devif.h" #include "can/can.h" #ifdef CONFIG_NET_TIMESTAMP #include #endif /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: can_data_event * * Description: * Handle data that is not accepted by the application because there is no * listener in place ready to receive the data. * * Assumptions: * - The caller has checked that CAN_NEWDATA is set in flags and that is no * other handler available to process the incoming data. * - This function must be called with the network locked. * ****************************************************************************/ static inline uint16_t can_data_event(FAR struct net_driver_s *dev, FAR struct can_conn_s *conn, uint16_t flags) { int buflen = dev->d_len; uint16_t recvlen; uint16_t ret; ret = (flags & ~CAN_NEWDATA); /* Save as the packet data as in the read-ahead buffer. NOTE that * partial packets will not be buffered. */ recvlen = can_datahandler(dev, conn); if (recvlen < buflen) { /* There is no handler to receive new data and there are no free * read-ahead buffers to retain the data -- drop the packet. */ ninfo("Dropped %d bytes\n", dev->d_len); #ifdef CONFIG_NET_STATISTICS /* No support CAN net statistics yet */ /* g_netstats.tcp.drop++; */ #endif } /* In any event, the new data has now been handled */ dev->d_len = 0; return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: can_callback * * Description: * Inform the application holding the packet socket of a change in state. * * Returned Value: * OK if packet has been processed, otherwise ERROR. * * Assumptions: * This function can be called from an interrupt. * ****************************************************************************/ uint16_t can_callback(FAR struct net_driver_s *dev, FAR struct can_conn_s *conn, uint16_t flags) { /* Some sanity checking */ if (conn) { /* Try to lock the network when successful send data to the listener */ if (net_trylock() == OK) { flags = devif_conn_event(dev, flags, conn->sconn.list); net_unlock(); } /* Either we did not get the lock or there is no application listening * If we did not get a lock we store the frame in the read-ahead buffer */ if ((flags & CAN_NEWDATA) != 0) { #ifdef CONFIG_NET_TIMESTAMP /* TIMESTAMP sockopt is activated, * create timestamp and copy to iob */ if (conn->timestamp) { struct timeval tv; FAR struct timespec *ts = (FAR struct timespec *)&tv; int len; clock_systime_timespec(ts); tv.tv_usec = ts->tv_nsec / 1000; len = iob_trycopyin(dev->d_iob, (FAR uint8_t *)&tv, sizeof(struct timeval), -CONFIG_NET_LL_GUARDSIZE, false); if (len != sizeof(struct timeval)) { dev->d_len = 0; return flags & ~CAN_NEWDATA; } else { dev->d_len += len; } } #endif /* Data was not handled.. dispose of it appropriately */ flags = can_data_event(dev, conn, flags); } } return flags; } /**************************************************************************** * Name: can_datahandler * * Description: * Handle data that is not accepted by the application. This may be called * either (1) from the data receive logic if it cannot buffer the data, or * (2) from the CAN event logic is there is no listener in place ready to * receive the data. * * Input Parameters: * dev - The device which as active when the event was detected. * conn - A pointer to the CAN connection structure * * Returned Value: * The number of bytes actually buffered is returned. This will be either * zero or equal to buflen; partial packets are not buffered. * * Assumptions: * - The caller has checked that CAN_NEWDATA is set in flags and that is no * other handler available to process the incoming data. * - This function must be called with the network locked. * ****************************************************************************/ uint16_t can_datahandler(FAR struct net_driver_s *dev, FAR struct can_conn_s *conn) { FAR struct iob_s *iob = dev->d_iob; int ret; /* Concat the iob to readahead */ ret = iob_tryadd_queue(iob, &conn->readahead); if (ret >= 0) { #ifdef CONFIG_NET_CAN_NOTIFIER /* Provide notification(s) that additional CAN read-ahead data is * available. */ can_readahead_signal(conn); #endif ret = iob->io_pktlen; /* Device buffer has been enqueued, clear the handle */ netdev_iob_clear(dev); } else { nerr("ERROR: Failed to queue the I/O buffer chain: %d\n", ret); netdev_iob_release(dev); } return ret; } #endif /* CONFIG_NET && CONFIG_NET_CAN */