/**************************************************************************** * net/arp/arp_send.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 #include #include "netdev/netdev.h" #include "devif/devif.h" #include "route/route.h" #include "arp/arp.h" #ifdef CONFIG_NET_ARP_SEND /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: arp_send_terminate ****************************************************************************/ static void arp_send_terminate(FAR struct arp_send_s *state, int result) { /* Don't allow any further call backs. */ state->snd_sent = true; state->snd_result = (int16_t)result; state->snd_cb->flags = 0; state->snd_cb->priv = NULL; state->snd_cb->event = NULL; /* Wake up the waiting thread */ nxsem_post(&state->snd_sem); } /**************************************************************************** * Name: arp_send_eventhandler ****************************************************************************/ static uint16_t arp_send_eventhandler(FAR struct net_driver_s *dev, FAR void *pvconn, FAR void *priv, uint16_t flags) { FAR struct arp_send_s *state = (FAR struct arp_send_s *)priv; ninfo("flags: %04x sent: %d\n", flags, state->snd_sent); if (state) { /* Is this the device that we need to route this request? */ if (strncmp((FAR const char *)dev->d_ifname, (FAR const char *)state->snd_ifname, IFNAMSIZ) != 0) { /* No... pass on this one and wait for the device that we want */ return flags; } /* Check if the network is still up */ if ((flags & NETDEV_DOWN) != 0) { nerr("ERROR: Interface is down\n"); arp_send_terminate(state, -ENETUNREACH); return flags; } /* 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 & PKT_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. */ /* REVISIT: No timeout. Just wait for the next polling cycle */ return flags; } /* It looks like we are good to send the data. * * Copy the packet data into the device packet buffer and send it. */ arp_format(dev, state->snd_ipaddr); /* Make sure no ARP request overwrites this ARP request. This * flag will be cleared in arp_out(). */ IFF_SET_NOARP(dev->d_flags); /* Don't allow any further call backs. */ arp_send_terminate(state, OK); } return flags; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: arp_send * * Description: * The arp_send() call may be to send an ARP request to resolve an IP * address. This function first checks if the IP address is already in * ARP table. If so, then it returns success immediately. * * If the requested IP address in not in the ARP table, then this function * will send an ARP request, delay, then check if the IP address is now in * the ARP table. It will repeat this sequence until either (1) the IP * address mapping is now in the ARP table, or (2) a configurable number * of timeouts occur without receiving the ARP replay. * * Input Parameters: * ipaddr The IP address to be queried (in network order). * * Returned Value: * Zero (OK) is returned on success and the IP address mapping can now be * found in the ARP table. On error a negated errno value is returned: * * -ETIMEDOUT: The number or retry counts has been exceed. * -EHOSTUNREACH: Could not find a route to the host * * Assumptions: * This function is called from the normal tasking context. * ****************************************************************************/ int arp_send(in_addr_t ipaddr) { FAR struct net_driver_s *dev; struct arp_notify_s notify; struct arp_send_s state; int ret; /* First check if destination is a local broadcast. */ if (ipaddr == INADDR_BROADCAST) { /* We don't need to send the ARP request */ return OK; } #ifdef CONFIG_NET_IGMP /* Check if the destination address is a multicast address * * - IPv4: multicast addresses lie in the class D group -- The address * range 224.0.0.0 to 239.255.255.255 (224.0.0.0/4) * * - IPv6 multicast addresses are have the high-order octet of the * addresses=0xff (ff00::/8.) */ if (NTOHL(ipaddr) >= 0xe0000000 && NTOHL(ipaddr) <= 0xefffffff) { /* We don't need to send the ARP request */ return OK; } #endif /* Get the device that can route this request */ dev = netdev_findby_ripv4addr(INADDR_ANY, ipaddr); if (!dev) { nerr("ERROR: Unreachable: %08lx\n", (unsigned long)ipaddr); ret = -EHOSTUNREACH; goto errout; } /* ARP support is only built if the Ethernet link layer is supported. * Continue and send the ARP request only if this device uses the * Ethernet link layer protocol. */ if (dev->d_lltype != NET_LL_ETHERNET && dev->d_lltype != NET_LL_IEEE80211) { return OK; } /* Check if the destination address is on the local network. */ if (!net_ipv4addr_maskcmp(ipaddr, dev->d_ipaddr, dev->d_netmask)) { in_addr_t dripaddr; /* Destination address is not on the local network */ #ifdef CONFIG_NET_ROUTE /* We have a routing table.. find the correct router to use in * this case (or, as a fall-back, use the device's default router * address). We will use the router IP address instead of the * destination address when determining the MAC address. */ netdev_ipv4_router(dev, ipaddr, &dripaddr); #else /* Use the device's default router IP address instead of the * destination address when determining the MAC address. */ net_ipv4addr_copy(dripaddr, dev->d_draddr); #endif ipaddr = dripaddr; } /* The destination address is on the local network. Check if it is * the sub-net broadcast address. */ else if (net_ipv4addr_broadcast(ipaddr, dev->d_netmask)) { /* Yes.. We don't need to send the ARP request */ return OK; } /* Allocate resources to receive a callback. This and the following * initialization is performed with the network lock because we don't * want anything to happen until we are ready. */ net_lock(); state.snd_cb = arp_callback_alloc(dev); if (!state.snd_cb) { nerr("ERROR: Failed to allocate a callback\n"); ret = -ENOMEM; goto errout_with_lock; } /* 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_retries = 0; /* No retries yet */ state.snd_ipaddr = ipaddr; /* IP address to query */ /* Remember the routing device name */ strncpy((FAR char *)state.snd_ifname, (FAR const char *)dev->d_ifname, IFNAMSIZ); /* Now loop, testing if the address mapping is in the ARP table and re- * sending the ARP request if it is not. */ ret = -ETIMEDOUT; /* Assume a timeout failure */ while (state.snd_retries < CONFIG_ARP_SEND_MAXTRIES) { /* Check if the address mapping is present in the ARP table. This * is only really meaningful on the first time through the loop. * * NOTE: If the ARP table is large than this could be a performance * issue. */ if (arp_find(ipaddr, NULL) >= 0) { /* We have it! Break out with success */ ret = OK; break; } /* Set up the ARP response wait BEFORE we send the ARP request */ arp_wait_setup(ipaddr, ¬ify); /* Arm/re-arm the callback */ state.snd_sent = false; state.snd_result = -EBUSY; state.snd_cb->flags = (ARP_POLL | NETDEV_DOWN); state.snd_cb->priv = (FAR void *)&state; state.snd_cb->event = arp_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_lockedwait will also terminate if a signal is received. */ do { ret = net_timedwait_uninterruptible(&state.snd_sem, CONFIG_ARP_SEND_DELAYMSEC); if (ret == -ETIMEDOUT) { arp_wait_cancel(¬ify); goto timeout; } } while (!state.snd_sent); /* Check the result of the send operation */ ret = state.snd_result; if (ret < 0) { /* Break out on a send failure */ nerr("ERROR: Send failed: %d\n", ret); arp_wait_cancel(¬ify); break; } /* Now wait for response to the ARP response to be received. */ ret = arp_wait(¬ify, CONFIG_ARP_SEND_DELAYMSEC); /* arp_wait will return OK if and only if the matching ARP response * is received. Otherwise, it will return -ETIMEDOUT. */ if (ret >= OK) { /* Break out if arp_wait() fails */ break; } timeout: /* Increment the retry count */ state.snd_retries++; nerr("ERROR: arp_wait failed: %d\n", ret); } nxsem_destroy(&state.snd_sem); arp_callback_free(dev, state.snd_cb); errout_with_lock: net_unlock(); errout: return ret; } #endif /* CONFIG_NET_ARP_SEND */