/**************************************************************************** * 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 #include "netdev/netdev.h" #include "devif/devif.h" #include "udp/udp.h" #include "socket/socket.h" /**************************************************************************** * 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 */ FAR struct msghdr *ir_msg; /* Receive info and buffer */ sem_t ir_sem; /* Semaphore signals recv completion */ ssize_t ir_recvlen; /* The received length */ int ir_result; /* Success:OK, failure:negated errno */ }; /**************************************************************************** * Private Functions ****************************************************************************/ static void udp_recvpktinfo(FAR struct udp_recvfrom_s *pstate, FAR void *srcaddr, uint8_t ifindex) { FAR struct msghdr *msg = pstate->ir_msg; FAR struct udp_conn_s *conn = pstate->ir_conn; FAR struct cmsghdr *control = msg->msg_control; size_t cmsg_len = 0; if (!(conn->flags & _UDP_FLAG_PKTINFO)) { goto out; } #ifdef CONFIG_NET_IPv4 if (conn->domain == PF_INET) { FAR struct sockaddr_in *infrom = srcaddr; FAR struct in_pktinfo *pkt_info = CMSG_DATA(control); if (msg->msg_controllen < CMSG_LEN(sizeof(struct in_pktinfo))) { goto out; } cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); control->cmsg_level = IPPROTO_IP; control->cmsg_type = IP_PKTINFO; control->cmsg_len = cmsg_len; pkt_info->ipi_ifindex = ifindex; pkt_info->ipi_addr.s_addr = infrom->sin_addr.s_addr; pkt_info->ipi_spec_dst.s_addr = conn->u.ipv4.laddr; } #endif #ifdef CONFIG_NET_IPv6 if (conn->domain == PF_INET6) { FAR struct sockaddr_in6 *infrom = srcaddr; FAR struct in6_pktinfo *pkt_info = CMSG_DATA(control); if (msg->msg_controllen < CMSG_LEN(sizeof(struct in6_pktinfo))) { goto out; } cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); control->cmsg_level = IPPROTO_IPV6; control->cmsg_type = IPV6_PKTINFO; control->cmsg_len = cmsg_len; pkt_info->ipi6_ifindex = ifindex; net_ipv6addr_copy(&pkt_info->ipi6_addr, infrom->sin6_addr.s6_addr); } #endif out: msg->msg_controllen = cmsg_len; } /**************************************************************************** * 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: * None. * * Assumptions: * The network is locked. * ****************************************************************************/ static inline 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_msg->msg_iov->iov_len) { recvlen = pstate->ir_msg->msg_iov->iov_len; } else { recvlen = dev->d_len; } /* Copy the new appdata into the user buffer */ recvlen = iob_copyout(pstate->ir_msg->msg_iov->iov_base, dev->d_iob, recvlen, dev->d_appdata - dev->d_iob->io_data - dev->d_iob->io_offset); /* Update the size of the data read */ pstate->ir_recvlen = recvlen; dev->d_len = 0; return recvlen; } static inline void udp_readahead(struct udp_recvfrom_s *pstate) { FAR struct udp_conn_s *conn = pstate->ir_conn; FAR struct iob_s *iob; /* 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) { int recvlen = pstate->ir_msg->msg_iov->iov_len; uint8_t src_addr_size; uint8_t offset = 0; FAR void *srcaddr; uint8_t ifindex; DEBUGASSERT(iob->io_pktlen > 0); /* Unflatten saved connection information */ #ifdef CONFIG_NETDEV_IFINDEX ifindex = iob->io_data[offset++]; #else ifindex = 0; #endif src_addr_size = iob->io_data[offset++]; srcaddr = &iob->io_data[offset]; /* Copy to user */ recvlen = iob_copyout(pstate->ir_msg->msg_iov->iov_base, iob, recvlen, 0); /* Update the accumulated size of the data read */ pstate->ir_recvlen = recvlen; ninfo("Received %d bytes (of %d)\n", recvlen, iob->io_pktlen); if (pstate->ir_msg->msg_name) { pstate->ir_msg->msg_namelen = src_addr_size > pstate->ir_msg->msg_namelen ? pstate->ir_msg->msg_namelen : src_addr_size; memcpy(pstate->ir_msg->msg_name, srcaddr, pstate->ir_msg->msg_namelen); } udp_recvpktinfo(pstate, srcaddr, ifindex); /* Remove the I/O buffer chain from the head of the read-ahead * buffer queue. */ iob_remove_queue(&conn->readahead); /* 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) { #ifdef CONFIG_NET_IPv6 uint8_t srcaddr[sizeof(struct sockaddr_in6)]; #else uint8_t srcaddr[sizeof(struct sockaddr_in)]; #endif socklen_t fromlen = 0; /* 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 *)srcaddr; 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 { #ifdef CONFIG_NET_IPv6 FAR struct udp_conn_s *conn = pstate->ir_conn; if (conn->domain == PF_INET6) { /* Hybrid dual-stack IPv6/IPv4 implementations recognize a special * class of addresses, the IPv4-mapped IPv6 addresses. */ FAR struct sockaddr_in6 *infrom6 = (FAR struct sockaddr_in6 *)srcaddr; 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 sockaddr_in *infrom = (FAR struct sockaddr_in *)srcaddr; 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 */ if (pstate->ir_msg->msg_name) { pstate->ir_msg->msg_namelen = fromlen > pstate->ir_msg->msg_namelen ? pstate->ir_msg->msg_namelen : fromlen; memcpy(pstate->ir_msg->msg_name, srcaddr, pstate->ir_msg->msg_namelen); } #ifdef CONFIG_NETDEV_IFINDEX udp_recvpktinfo(pstate, srcaddr, dev->d_ifindex); #else udp_recvpktinfo(pstate, srcaddr, 0); #endif } /**************************************************************************** * 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. * pvpriv An instance of struct udp_recvfrom_s cast to void* * 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 *pvpriv, uint16_t flags) { FAR struct udp_recvfrom_s *pstate = 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) { /* Save the sender's address in the caller's 'from' location */ udp_sender(dev, pstate); /* Copy the data from the packet */ udp_recvfrom_newdata(dev, pstate); /* We are finished. */ ninfo("UDP done\n"); /* Don't allow any further UDP call backs. */ udp_terminate(pstate, OK); /* Indicate that the data has been consumed */ flags &= ~UDP_NEWDATA; /* Indicate no data in the buffer */ netdev_iob_release(dev); } } return flags; } /**************************************************************************** * Name: udp_recvfrom_initialize * * Description: * Initialize the state structure * * Input Parameters: * conn The UDP connection of interest * msg Receive info and buffer for receive data * 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 struct msghdr *msg, FAR struct udp_recvfrom_s *pstate) { /* Initialize the state structure. */ memset(pstate, 0, sizeof(struct udp_recvfrom_s)); nxsem_init(&pstate->ir_sem, 0, 0); /* Doesn't really fail */ pstate->ir_msg = msg; /* 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_sem_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_sem_timedwait failed, then we were probably reawakened by a * signal. In this case, net_sem_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 * msg Receive info and buffer for receive data * * 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 struct msghdr *msg, int flags) { 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, msg, &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_sem_timedwait will also terminate if a signal is * received. */ ret = net_sem_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 */