/**************************************************************************** * net/pkt/pkt_recvfrom.c * * Copyright (C) 2007-2009, 2011-2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #ifdef CONFIG_NET #include #include #include #include #include #include #include #include #include #include #include #include #include "netdev/netdev.h" #include "devif/devif.h" #include "pkt/pkt.h" #include "socket/socket.h" #include /**************************************************************************** * Private Types ****************************************************************************/ struct pkt_recvfrom_s { 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 */ uint8_t *pr_buffer; /* Pointer to receive buffer */ ssize_t pr_recvlen; /* The received length */ int pr_result; /* Success:OK, failure:negated errno */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: pkt_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 pkt_add_recvlen(FAR struct pkt_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: pkt_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 void pkt_recvfrom_newdata(FAR struct net_driver_s *dev, FAR struct pkt_recvfrom_s *pstate) { size_t recvlen; 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 */ memcpy(pstate->pr_buffer, dev->d_buf, recvlen); ninfo("Received %d bytes (of %d)\n", (int)recvlen, (int)dev->d_len); /* Update the accumulated size of the data read */ pkt_add_recvlen(pstate, recvlen); } /**************************************************************************** * Name: pkt_recvfrom_sender * * Description: * * Input Parameters: * * Returned Value: * * Assumptions: * ****************************************************************************/ static inline void pkt_recvfrom_sender(FAR struct net_driver_s *dev, FAR struct pkt_recvfrom_s *pstate) { } /**************************************************************************** * Name: pkt_recvfrom_eventhandler * * Description: * * Input Parameters: * * Returned Value: * * Assumptions: * ****************************************************************************/ static uint16_t pkt_recvfrom_eventhandler(FAR struct net_driver_s *dev, FAR void *pvconn, FAR void *pvpriv, uint16_t flags) { struct pkt_recvfrom_s *pstate = (struct pkt_recvfrom_s *)pvpriv; ninfo("flags: %04x\n", flags); /* 'priv' might be null in some race conditions (?) */ if (pstate) { /* If a new packet is available, then complete the read action. */ if ((flags & PKT_NEWDATA) != 0) { /* Copy the packet */ pkt_recvfrom_newdata(dev, pstate); /* We are finished. */ ninfo("PKT done\n"); /* Don't allow any further call backs. */ pstate->pr_cb->flags = 0; pstate->pr_cb->priv = NULL; pstate->pr_cb->event = NULL; /* Save the sender's address in the caller's 'from' location */ pkt_recvfrom_sender(dev, pstate); /* indicate that the data has been consumed */ flags &= ~PKT_NEWDATA; /* Wake up the waiting thread, returning the number of bytes * actually read. */ nxsem_post(&pstate->pr_sem); } } return flags; } /**************************************************************************** * Name: pkt_recvfrom_initialize * * Description: * Initialize the state structure * * Input Parameters: * psock Pointer to the socket structure for the socket * buf Buffer to receive data * len Length of buffer * pstate A pointer to the state structure to be initialized * * Returned Value: * None * * Assumptions: * ****************************************************************************/ static void pkt_recvfrom_initialize(FAR struct socket *psock, FAR void *buf, size_t len, FAR struct sockaddr *infrom, FAR socklen_t *fromlen, FAR struct pkt_recvfrom_s *pstate) { /* Initialize the state structure. */ memset(pstate, 0, sizeof(struct pkt_recvfrom_s)); /* This semaphore is used for signaling and, hence, should not have * priority inheritance enabled. */ nxsem_init(&pstate->pr_sem, 0, 0); /* Doesn't really fail */ nxsem_setprotocol(&pstate->pr_sem, SEM_PRIO_NONE); pstate->pr_buflen = len; pstate->pr_buffer = buf; } /* The only un-initialization that has to be performed is destroying the * semaphore. */ #define pkt_recvfrom_uninitialize(s) nxsem_destroy(&(s)->pr_sem) /**************************************************************************** * Name: pkt_recvfrom_result * * Description: * Evaluate the result of the recv operations * * Input Parameters: * result The result of the net_lockedwait 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 pkt_recvfrom_result(int result, struct pkt_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 or ENOTCONN on loss of * connection (TCP only) */ return pstate->pr_result; } /* If net_lockedwait failed, then we were probably reawakened by a signal. In * this case, net_lockedwait will have returned negated errno appropriately. */ if (result < 0) { return result; } return pstate->pr_recvlen; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: pkt_recvfrom * * Description: * Implements the socket recvfrom interface for the case of the AF_INET * and AF_INET6 address families. pkt_recvfrom() 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 'fromlen' is * 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 * buf Buffer to receive data * len Length of buffer * flags Receive flags * from Address of source (may be NULL) * fromlen The length of the address structure * * Returned Value: * On success, returns the number of characters received. If no data is * available to be received and the peer has performed an orderly shutdown, * recv() will return 0. Otherwise, on errors, a negated errno value is * returned (see recvfrom() for the list of appropriate error values). * ****************************************************************************/ ssize_t pkt_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len, int flags, FAR struct sockaddr *from, FAR socklen_t *fromlen) { FAR struct pkt_conn_s *conn = (FAR struct pkt_conn_s *)psock->s_conn; FAR struct net_driver_s *dev; struct pkt_recvfrom_s state; ssize_t ret; /* If a 'from' address has been provided, verify that it is large * enough to hold this address family. */ if (from != NULL && *fromlen < sizeof(sa_family_t)) { return -EINVAL; } if (psock->s_type != SOCK_RAW) { nerr("ERROR: Unsupported socket type: %d\n", psock->s_type); ret = -ENOSYS; } /* Perform the packet recvfrom() 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(); pkt_recvfrom_initialize(psock, buf, len, from, fromlen, &state); /* Get the device driver that will service this transfer */ dev = pkt_find_device(conn); if (dev == NULL) { ret = -ENODEV; goto errout_with_state; } /* TODO pkt_recvfrom_initialize() expects from to be of type sockaddr_in, but * in our case is sockaddr_ll */ #if 0 ret = pkt_connect(conn, NULL); if (ret < 0) { goto errout_with_state; } #endif /* Set up the callback in the connection */ state.pr_cb = pkt_callback_alloc(dev, conn); if (state.pr_cb) { state.pr_cb->flags = (PKT_NEWDATA | PKT_POLL); state.pr_cb->priv = (FAR void *)&state; state.pr_cb->event = pkt_recvfrom_eventhandler; /* Wait for either the receive to complete or for an error/timeout to * occur. NOTES: (1) net_lockedwait 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_lockedwait(&state.pr_sem); /* Make sure that no further events are processed */ pkt_callback_free(dev, conn, state.pr_cb); ret = pkt_recvfrom_result(ret, &state); } else { ret = -EBUSY; } errout_with_state: net_unlock(); pkt_recvfrom_uninitialize(&state); return ret; } #endif /* CONFIG_NET */