/**************************************************************************** * net/udp/udp_recvfrom.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_UDP) #include #include #include #include #include #include #include #include #include #include #include "netdev/netdev.h" #include "devif/devif.h" #include "udp/udp.h" #include "socket/socket.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define IPv4BUF ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)]) #define IPv6BUF ((FAR struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)]) #define UDPIPv4BUF ((FAR struct udp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN]) #define UDPIPv6BUF ((FAR struct udp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN]) /**************************************************************************** * Private Types ****************************************************************************/ struct udp_recvfrom_s { FAR struct udp_conn_s *ir_conn; /* Connection associated with the socket */ FAR struct devif_callback_s *ir_cb; /* Reference to callback instance */ sem_t ir_sem; /* Semaphore signals recv completion */ size_t ir_buflen; /* Length of receive buffer */ uint8_t *ir_buffer; /* Pointer to receive buffer */ FAR struct sockaddr *ir_from; /* Address of sender */ FAR socklen_t *ir_fromlen; /* Number of bytes allocated for address of sender */ ssize_t ir_recvlen; /* The received length */ int ir_result; /* Success:OK, failure:negated errno */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: udp_update_recvlen * * Description: * Update information about space available for new data and update size * of data in buffer, This logic accounts for the case where * udp_readahead() sets state.ir_recvlen == -1 . * * Input Parameters: * pstate recvfrom state structure * recvlen size of new data appended to buffer * * Returned Value: * None * ****************************************************************************/ static inline void udp_update_recvlen(FAR struct udp_recvfrom_s *pstate, size_t recvlen) { if (pstate->ir_recvlen < 0) { pstate->ir_recvlen = 0; } pstate->ir_recvlen += recvlen; pstate->ir_buffer += recvlen; pstate->ir_buflen -= recvlen; } /**************************************************************************** * Name: udp_recvfrom_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: * The number of bytes taken from the packet. * * Assumptions: * The network is locked. * ****************************************************************************/ static size_t udp_recvfrom_newdata(FAR struct net_driver_s *dev, FAR struct udp_recvfrom_s *pstate) { size_t recvlen; /* Get the length of the data to return */ if (dev->d_len > pstate->ir_buflen) { recvlen = pstate->ir_buflen; } else { recvlen = dev->d_len; } /* Copy the new appdata into the user buffer */ memcpy(pstate->ir_buffer, dev->d_appdata, recvlen); ninfo("Received %d bytes (of %d)\n", (int)recvlen, (int)dev->d_len); /* Update the accumulated size of the data read */ udp_update_recvlen(pstate, recvlen); return recvlen; } /**************************************************************************** * Name: udp_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 udp_newdata(FAR struct net_driver_s *dev, FAR struct udp_recvfrom_s *pstate) { /* Take as much data from the packet as we can */ udp_recvfrom_newdata(dev, pstate); /* Indicate no data in the buffer */ dev->d_len = 0; } static inline void udp_readahead(struct udp_recvfrom_s *pstate) { FAR struct udp_conn_s *conn = pstate->ir_conn; FAR struct iob_s *iob; int recvlen; /* Check there is any UDP datagram already buffered in a read-ahead * buffer. */ pstate->ir_recvlen = -1; if ((iob = iob_peek_queue(&conn->readahead)) != NULL) { FAR struct iob_s *tmp; uint8_t src_addr_size; DEBUGASSERT(iob->io_pktlen > 0); /* Transfer that buffered data from the I/O buffer chain into * the user buffer. */ recvlen = iob_copyout(&src_addr_size, iob, sizeof(uint8_t), 0); if (recvlen != sizeof(uint8_t)) { goto out; } if (0 #ifdef CONFIG_NET_IPv6 || src_addr_size == sizeof(struct sockaddr_in6) #endif #ifdef CONFIG_NET_IPv4 || src_addr_size == sizeof(struct sockaddr_in) #endif ) { if (pstate->ir_from) { socklen_t len = *pstate->ir_fromlen; len = (socklen_t) src_addr_size > len ? len : (socklen_t)src_addr_size; recvlen = iob_copyout((FAR uint8_t *)pstate->ir_from, iob, len, sizeof(uint8_t)); if (recvlen != len) { goto out; } } } if (pstate->ir_buflen > 0) { recvlen = iob_copyout(pstate->ir_buffer, iob, pstate->ir_buflen, src_addr_size + sizeof(uint8_t)); ninfo("Received %d bytes (of %d)\n", recvlen, iob->io_pktlen); /* Update the accumulated size of the data read */ pstate->ir_recvlen = recvlen; pstate->ir_buffer += recvlen; pstate->ir_buflen -= recvlen; *pstate->ir_fromlen = src_addr_size; } else { pstate->ir_recvlen = 0; } out: /* Remove the I/O buffer chain from the head of the read-ahead * buffer queue. */ tmp = iob_remove_queue(&conn->readahead); DEBUGASSERT(tmp == iob); UNUSED(tmp); /* And free the I/O buffer chain */ iob_free_chain(iob); } } /**************************************************************************** * Name: udp_sender * * Description: * Getting the sender's address from the UDP packet * * Input Parameters: * dev - The device driver data structure * pstate - the recvfrom state structure * * Returned Value: * None * * Assumptions: * The network is locked. * ****************************************************************************/ static inline void udp_sender(FAR struct net_driver_s *dev, FAR struct udp_recvfrom_s *pstate) { /* Get the family from the packet type, IP address from the IP header, and * the port number from the UDP header. */ #ifdef CONFIG_NET_IPv6 #ifdef CONFIG_NET_IPv4 if (IFF_IS_IPv6(dev->d_flags)) #endif { FAR struct sockaddr_in6 *infrom = (FAR struct sockaddr_in6 *)pstate->ir_from; FAR socklen_t *fromlen = pstate->ir_fromlen; if (infrom) { FAR struct udp_hdr_s *udp = UDPIPv6BUF; FAR struct ipv6_hdr_s *ipv6 = IPv6BUF; infrom->sin6_family = AF_INET6; infrom->sin6_port = udp->srcport; *fromlen = sizeof(struct sockaddr_in6); net_ipv6addr_copy(infrom->sin6_addr.s6_addr, ipv6->srcipaddr); } } #endif /* CONFIG_NET_IPv6 */ #ifdef CONFIG_NET_IPv4 #ifdef CONFIG_NET_IPv6 else #endif { FAR struct sockaddr_in *infrom = (FAR struct sockaddr_in *)pstate->ir_from; FAR socklen_t *fromlen = pstate->ir_fromlen; if (infrom) { #ifdef CONFIG_NET_IPv6 FAR struct udp_conn_s *conn = pstate->ir_conn; /* Hybrid dual-stack IPv6/IPv4 implementations recognize a special * class of addresses, the IPv4-mapped IPv6 addresses. */ if (conn->domain == PF_INET6) { FAR struct sockaddr_in6 *infrom6 = (FAR struct sockaddr_in6 *)infrom; FAR struct udp_hdr_s *udp = UDPIPv6BUF; FAR struct ipv6_hdr_s *ipv6 = IPv6BUF; in_addr_t ipv4addr; /* Encode the IPv4 address as an IPv4-mapped IPv6 address */ infrom6->sin6_family = AF_INET6; infrom6->sin6_port = udp->srcport; *fromlen = sizeof(struct sockaddr_in6); ipv4addr = net_ip4addr_conv32(ipv6->srcipaddr); ip6_map_ipv4addr(ipv4addr, infrom6->sin6_addr.s6_addr16); } else #endif { FAR struct udp_hdr_s *udp = UDPIPv4BUF; FAR struct ipv4_hdr_s *ipv4 = IPv4BUF; infrom->sin_family = AF_INET; infrom->sin_port = udp->srcport; *fromlen = sizeof(struct sockaddr_in); net_ipv4addr_copy(infrom->sin_addr.s_addr, net_ip4addr_conv32(ipv4->srcipaddr)); memset(infrom->sin_zero, 0, sizeof(infrom->sin_zero)); } } } #endif /* CONFIG_NET_IPv4 */ } /**************************************************************************** * Name: udp_terminate * * Description: * Terminate the UDP transfer. * * Input Parameters: * pstate - The recvfrom state structure * result - The result of the operation * * Returned Value: * None * ****************************************************************************/ static void udp_terminate(FAR struct udp_recvfrom_s *pstate, int result) { /* Don't allow any further UDP call backs. */ pstate->ir_cb->flags = 0; pstate->ir_cb->priv = NULL; pstate->ir_cb->event = NULL; /* Save the result of the transfer */ pstate->ir_result = result; /* Wake up the waiting thread, returning the number of bytes * actually read. */ nxsem_post(&pstate->ir_sem); } /**************************************************************************** * Name: udp_eventhandler * * Description: * This function is called with the network locked to perform the actual * UDP receive operation via by the lower, device interfacing layer. * * Input Parameters: * dev The structure of the network driver that generated the event. * pvconn The connection structure associated with the socket * flags Set of events describing why the callback was invoked * * Returned Value: * None * * Assumptions: * The network is locked. * ****************************************************************************/ static uint16_t udp_eventhandler(FAR struct net_driver_s *dev, FAR void *pvconn, FAR void *pvpriv, uint16_t flags) { FAR struct udp_recvfrom_s *pstate = (FAR struct udp_recvfrom_s *)pvpriv; ninfo("flags: %04x\n", flags); /* 'priv' might be null in some race conditions (?) */ if (pstate) { /* If the network device has gone down, then we will have terminate * the wait now with an error. */ if ((flags & NETDEV_DOWN) != 0) { /* Terminate the transfer with an error. */ nerr("ERROR: Network is down\n"); udp_terminate(pstate, -ENETUNREACH); } /* If new data is available, then complete the read action. */ else if ((flags & UDP_NEWDATA) != 0) { /* Copy the data from the packet */ udp_newdata(dev, pstate); /* We are finished. */ ninfo("UDP done\n"); /* Save the sender's address in the caller's 'from' location */ udp_sender(dev, pstate); /* Don't allow any further UDP call backs. */ udp_terminate(pstate, OK); /* Indicate that the data has been consumed */ flags &= ~UDP_NEWDATA; } } return flags; } /**************************************************************************** * Name: udp_recvfrom_initialize * * Description: * Initialize the state structure * * Input Parameters: * conn The UDP connection of interest * 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 udp_recvfrom_initialize(FAR struct udp_conn_s *conn, FAR void *buf, size_t len, FAR struct sockaddr *infrom, FAR socklen_t *fromlen, FAR struct udp_recvfrom_s *pstate) { /* Initialize the state structure. */ memset(pstate, 0, sizeof(struct udp_recvfrom_s)); /* This semaphore is used for signaling and, hence, should not have * priority inheritance enabled. */ nxsem_init(&pstate->ir_sem, 0, 0); /* Doesn't really fail */ nxsem_set_protocol(&pstate->ir_sem, SEM_PRIO_NONE); pstate->ir_buflen = len; pstate->ir_buffer = buf; pstate->ir_from = infrom; pstate->ir_fromlen = fromlen; /* Set up the start time for the timeout */ pstate->ir_conn = conn; } /* The only un-initialization that has to be performed is destroying the * semaphore. */ #define udp_recvfrom_uninitialize(s) nxsem_destroy(&(s)->ir_sem) /**************************************************************************** * Name: udp_recvfrom_result * * Description: * Evaluate the result of the recv operations * * Input Parameters: * result The result of the net_timedwait 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 udp_recvfrom_result(int result, struct udp_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->ir_result < 0) { /* This might return EAGAIN on a timeout or ENOTCONN on loss of * connection (TCP only) */ return pstate->ir_result; } /* If net_timedwait failed, then we were probably reawakened by a signal. * In this case, net_timedwait will have returned negated errno * appropriately. */ if (result < 0) { return result; } return pstate->ir_recvlen; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: psock_udp_recvfrom * * Description: * Perform the recvfrom operation for a UDP SOCK_DGRAM * * Input Parameters: * psock Pointer to the socket structure for the SOCK_DRAM socket * buf Buffer to receive data * len Length of buffer * from INET address of source (may be NULL) * * Returned Value: * On success, returns the number of characters received. On error, * -errno is returned (see recvfrom for list of errnos). * * Assumptions: * ****************************************************************************/ ssize_t psock_udp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len, int flags, FAR struct sockaddr *from, FAR socklen_t *fromlen) { FAR struct udp_conn_s *conn = (FAR struct udp_conn_s *)psock->s_conn; FAR struct net_driver_s *dev; struct udp_recvfrom_s state; int ret; /* Perform the UDP 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(); udp_recvfrom_initialize(conn, buf, len, from, fromlen, &state); /* Copy the read-ahead data from the packet */ udp_readahead(&state); /* The default return value is the number of bytes that we just copied * into the user buffer. We will return this if the socket has become * disconnected or if the user request was completely satisfied with * data from the readahead buffers. */ ret = state.ir_recvlen; /* Handle non-blocking UDP 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; } } /* It is okay to block if we need to. If there is space to receive * anything more, then we will wait to receive the data. Otherwise * return the number of bytes read from the read-ahead buffer * (already in 'ret'). * * NOTE: that udp_readahead() may set state.ir_recvlen == -1. */ else if (state.ir_recvlen <= 0) { /* Get the device that will handle the packet transfers. This may be * NULL if the UDP socket is bound to INADDR_ANY. In that case, no * NETDEV_DOWN notifications will be received. */ dev = udp_find_laddr_device(conn); /* Set up the callback in the connection */ state.ir_cb = udp_callback_alloc(dev, conn); if (state.ir_cb) { /* Set up the callback in the connection */ state.ir_cb->flags = (UDP_NEWDATA | NETDEV_DOWN); state.ir_cb->priv = (FAR void *)&state; state.ir_cb->event = udp_eventhandler; /* Wait for either the receive to complete or for an error/timeout * to occur. net_timedwait will also terminate if a signal is * received. */ ret = net_timedwait(&state.ir_sem, _SO_TIMEOUT(conn->sconn.s_rcvtimeo)); if (ret == -ETIMEDOUT) { ret = -EAGAIN; } /* Make sure that no further events are processed */ udp_callback_free(dev, conn, state.ir_cb); ret = udp_recvfrom_result(ret, &state); } else { ret = -EBUSY; } } net_unlock(); udp_recvfrom_uninitialize(&state); return ret; } #endif /* CONFIG_NET && CONFIG_NET_UDP */