/**************************************************************************** * 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 #if defined(CONFIG_NET) && defined(CONFIG_NET_CAN) #include #include #include #include #include #include #include #include #include #include #include #include #include "netdev/netdev.h" #include "devif/devif.h" #include "socket/socket.h" #include "can/can.h" #include /**************************************************************************** * 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 socket *snd_sock; /* Points to the parent socket structure */ 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 *pvconn, FAR void *pvpriv, uint16_t flags) { FAR struct send_s *pstate = (FAR struct send_s *)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 */ devif_can_send(dev, pstate->snd_buffer, pstate->snd_buflen); 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; } } /* 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 = (FAR struct can_conn_s *)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)); /* This semaphore is used for signaling and, hence, should not have * priority inheritance enabled. */ nxsem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */ nxsem_set_protocol(&state.snd_sem, SEM_PRIO_NONE); state.snd_sock = psock; /* Socket descriptor */ 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)) { 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_timedwait will also terminate if a signal is received. */ if (_SS_ISNONBLOCK(conn->sconn.s_flags) || (flags & MSG_DONTWAIT) != 0) { ret = net_timedwait(&state.snd_sem, 0); } else { ret = net_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_lockedwait failed, then we were probably reawakened by a signal. * In this case, net_lockedwait 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 */