/**************************************************************************** * net/icmp/icmp_recvmsg.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 #include #include #include #include #include #include #include #include "devif/devif.h" #include "socket/socket.h" #include "icmp/icmp.h" #ifdef CONFIG_NET_ICMP_SOCKET /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define IPv4BUF ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)]) #define ICMPBUF ((FAR struct icmp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN]) #define ICMPSIZE ((dev)->d_len - IPv4_HDRLEN) /**************************************************************************** * Private Types ****************************************************************************/ struct icmp_recvfrom_s { FAR struct devif_callback_s *recv_cb; /* Reference to callback instance */ FAR struct socket *recv_sock; /* IPPROTO_ICMP socket structure */ sem_t recv_sem; /* Use to manage the wait for the * response */ in_addr_t recv_from; /* The peer we received the request * from */ FAR uint8_t *recv_buf; /* Location to return the response */ uint16_t recv_buflen; /* Size of the response */ int16_t recv_result; /* >=0: receive size on success; * <0: negated errno on fail */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: recvfrom_eventhandler * * Description: * This function is called with the network locked to perform the actual * ECHO request and/or ECHO reply actions when polled by the lower, device * interfacing layer. * * Input Parameters: * dev The structure of the network driver that generated the * event. * conn The received packet, cast to (void *) * pvpriv An instance of struct icmp_recvfrom_s cast to void* * flags Set of events describing why the callback was invoked * * Returned Value: * Modified value of the input flags * * Assumptions: * The network is locked. * ****************************************************************************/ static uint16_t recvfrom_eventhandler(FAR struct net_driver_s *dev, FAR void *pvconn, FAR void *pvpriv, uint16_t flags) { FAR struct icmp_recvfrom_s *pstate = (struct icmp_recvfrom_s *)pvpriv; FAR struct socket *psock; FAR struct icmp_conn_s *conn; FAR struct ipv4_hdr_s *ipv4; FAR struct icmp_hdr_s *icmp; ninfo("flags: %04x\n", flags); if (pstate != NULL) { /* Check if the network is still up */ if ((flags & NETDEV_DOWN) != 0) { nerr("ERROR: Interface is down\n"); pstate->recv_result = -ENETUNREACH; goto end_wait; } /* Is this a response on the same device that we sent the request out * on? */ psock = pstate->recv_sock; DEBUGASSERT(psock != NULL && psock->s_conn != NULL); conn = psock->s_conn; if (dev != conn->dev) { ninfo("Wrong device\n"); return flags; } /* Check if we have just received a ICMP ECHO reply. */ if ((flags & ICMP_NEWDATA) != 0) /* No incoming data */ { unsigned int recvsize; /* Check if it is for us */ icmp = ICMPBUF; if (conn->id != icmp->id) { ninfo("Wrong ID: %u vs %u\n", icmp->id, conn->id); return flags; } ninfo("Received ICMP reply\n"); /* What should we do if the received reply is larger that the * buffer that the caller of sendto provided? Truncate? Error * out? */ recvsize = ICMPSIZE; if (recvsize > pstate->recv_buflen) { recvsize = pstate->recv_buflen; } /* Copy the ICMP ECHO reply to the user provided buffer */ memcpy(pstate->recv_buf, ICMPBUF, recvsize); /* Return the size of the returned data */ DEBUGASSERT(recvsize <= INT16_MAX); pstate->recv_result = recvsize; /* Return the IPv4 address of the sender from the IPv4 header */ ipv4 = IPv4BUF; net_ipv4addr_hdrcopy(&pstate->recv_from, ipv4->srcipaddr); /* Decrement the count of outstanding requests. I suppose this * could have already been decremented of there were multiple * threads calling sendto() or recvfrom(). If there finds, we * may have to beef up the design. */ DEBUGASSERT(conn->nreqs > 0); conn->nreqs--; /* Indicate that the data has been consumed */ flags &= ~ICMP_NEWDATA; dev->d_len = 0; goto end_wait; } /* Continue waiting */ } return flags; end_wait: ninfo("Resuming\n"); /* Do not allow any further callbacks */ pstate->recv_cb->flags = 0; pstate->recv_cb->priv = NULL; pstate->recv_cb->event = NULL; /* Wake up the waiting thread */ nxsem_post(&pstate->recv_sem); return flags; } /**************************************************************************** * Name: icmp_readahead * * Description: * Copy the buffered read-ahead data to the user buffer. * * Input Parameters: * conn - IPPROTO_ICMP socket connection structure containing the read- * ahead data. * dev The structure of the network driver that generated the event. * pstate recvfrom state structure * * Returned Value: * Number of bytes copied to the user buffer * * Assumptions: * The network is locked. * ****************************************************************************/ static inline ssize_t icmp_readahead(FAR struct icmp_conn_s *conn, FAR void *buf, size_t buflen, FAR struct sockaddr_in *from, FAR socklen_t *fromlen) { FAR struct sockaddr_in bitbucket; FAR struct iob_s *iob; ssize_t ret = -ENODATA; int recvlen; /* Check there is any ICMP replies already buffered in a read-ahead * buffer. */ if ((iob = iob_peek_queue(&conn->readahead)) != NULL) { FAR struct iob_s *tmp; uint16_t offset; uint8_t addrsize; DEBUGASSERT(iob->io_pktlen > 0); /* Transfer that buffered data from the I/O buffer chain into * the user buffer. */ /* First get the size of the address */ recvlen = iob_copyout(&addrsize, iob, sizeof(uint8_t), 0); if (recvlen != sizeof(uint8_t)) { ret = -EIO; goto out; } offset = sizeof(uint8_t); if (addrsize > sizeof(struct sockaddr_in)) { ret = -EINVAL; goto out; } /* Then get address */ if (from == NULL) { from = &bitbucket; } recvlen = iob_copyout((FAR uint8_t *)from, iob, addrsize, offset); if (recvlen != addrsize) { ret = -EIO; goto out; } if (fromlen != NULL) { *fromlen = addrsize; } offset += addrsize; /* And finally, get the buffered data */ ret = (ssize_t)iob_copyout(buf, iob, buflen, offset); ninfo("Received %ld bytes (of %u)\n", (long)ret, iob->io_pktlen); 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, IOBUSER_NET_SOCK_ICMP); } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: icmp_recvmsg * * Description: * Implements the socket recvfrom interface for the case of the AF_INET * data gram socket with the IPPROTO_ICMP protocol. icmp_recvmsg() * receives ICMP ECHO replies for the a socket. * * If msg_name is not NULL, and the underlying protocol provides the source * address, this source address is filled in. The argument 'msg_namelen' is * initialized to the size of the buffer associated with msg_name, 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 * msg Buffer to receive the message * flags Receive flags * * 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, * recvmsg() will return 0. Otherwise, on errors, a negated errno value is * returned (see recvmsg() for the list of appropriate error values). * ****************************************************************************/ ssize_t icmp_recvmsg(FAR struct socket *psock, FAR struct msghdr *msg, int flags) { FAR void *buf = msg->msg_iov->iov_base; size_t len = msg->msg_iov->iov_len; FAR struct sockaddr *from = msg->msg_name; FAR socklen_t *fromlen = &msg->msg_namelen; FAR struct sockaddr_in *inaddr; FAR struct icmp_conn_s *conn; FAR struct net_driver_s *dev; struct icmp_recvfrom_s state; ssize_t ret; /* Some sanity checks */ DEBUGASSERT(psock != NULL && psock->s_conn != NULL && buf != NULL); if (len < ICMP_HDRLEN) { return -EINVAL; } /* If a 'from' address has been provided, verify that it is large * enough to hold the AF_INET address. */ if (from != NULL) { if (fromlen == NULL || *fromlen < sizeof(struct sockaddr_in)) { return -EINVAL; } } net_lock(); /* We cannot receive a response from a device until a request has been * sent to the devivce. */ conn = psock->s_conn; if (conn->nreqs < 1) { ret = -EPROTO; goto errout; } /* Get the device that was used to send the ICMP request. */ dev = conn->dev; DEBUGASSERT(dev != NULL); if (dev == NULL) { ret = -EPROTO; goto errout; } /* Check if there is buffered read-ahead data for this socket. We may have * already received the response to previous command. */ if (!IOB_QEMPTY(&conn->readahead)) { ret = icmp_readahead(conn, buf, len, (FAR struct sockaddr_in *)from, fromlen); } else if (_SS_ISNONBLOCK(conn->sconn.s_flags) || (flags & MSG_DONTWAIT) != 0) { /* Handle non-blocking ICMP sockets */ ret = -EAGAIN; } else { /* Initialize the state structure */ memset(&state, 0, sizeof(struct icmp_recvfrom_s)); /* This semaphore is used for signaling and, hence, should not have * priority inheritance enabled. */ nxsem_init(&state.recv_sem, 0, 0); nxsem_set_protocol(&state.recv_sem, SEM_PRIO_NONE); state.recv_sock = psock; /* The IPPROTO_ICMP socket instance */ state.recv_result = -ENOMEM; /* Assume allocation failure */ state.recv_buf = buf; /* Location to return the response */ state.recv_buflen = len; /* Size of the response */ /* Set up the callback */ state.recv_cb = icmp_callback_alloc(dev, conn); if (state.recv_cb != NULL) { state.recv_cb->flags = (ICMP_NEWDATA | NETDEV_DOWN); state.recv_cb->priv = (FAR void *)&state; state.recv_cb->event = recvfrom_eventhandler; /* Wait for either the response to be received or for timeout to * occur. net_timedwait will also terminate if a signal is * received. */ ret = net_timedwait(&state.recv_sem, _SO_TIMEOUT(psock->s_rcvtimeo)); if (ret < 0) { state.recv_result = ret; } icmp_callback_free(dev, conn, state.recv_cb); } /* Return the negated error number in the event of a failure, or the * number of bytes received on success. */ if (state.recv_result < 0) { nerr("ERROR: Return error=%d\n", state.recv_result); ret = state.recv_result; goto errout; } if (from != NULL) { inaddr = (FAR struct sockaddr_in *)from; inaddr->sin_family = AF_INET; inaddr->sin_port = 0; net_ipv4addr_copy(inaddr->sin_addr.s_addr, state.recv_from); } ret = state.recv_result; /* If there a no further outstanding requests, * make sure that the request struct is left pristine. */ errout: if (conn->nreqs < 1) { conn->id = 0; conn->nreqs = 0; conn->dev = NULL; iob_free_queue(&conn->readahead, IOBUSER_NET_SOCK_ICMP); } } net_unlock(); return ret; } #endif /* CONFIG_NET_ICMP_SOCKET */