216 lines
7.5 KiB
C
216 lines
7.5 KiB
C
/****************************************************************************
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* net/arp/arp_input.c
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (C) 2007-2011, 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Based on uIP which also has a BSD style license:
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*
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* Author: Adam Dunkels <adam@dunkels.com>
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* Copyright (c) 2001-2003, Adam Dunkels.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <string.h>
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#include <debug.h>
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#include <netinet/in.h>
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#include <nuttx/net/netdev.h>
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#include "arp/arp.h"
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#include "devif/devif.h"
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#ifdef CONFIG_NET_ARP
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: arp_in
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*
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* Description:
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* This function should be called by the Ethernet device driver when an
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* ARP packet has been received. The function will act differently
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* depending on the ARP packet type: if it is a reply for a request
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* that we previously sent out, the ARP cache will be filled in with
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* the values from the ARP reply. If the incoming ARP packet is an ARP
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* request for our IP address, an ARP reply packet is created and put
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* into the d_buf buffer.
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*
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* On entry, this function expects that an ARP packet with a prepended
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* Ethernet header is present in the d_buf buffer and that the length of
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* the packet is set in the d_len field.
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*
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* When the function returns, the value of the field d_len indicates
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* whether the device driver should send out the ARP reply packet or not.
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* If d_len is zero, no packet should be sent; If d_len is non-zero, it
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* contains the length of the outbound packet that is present in the
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* d_buf buffer.
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*
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****************************************************************************/
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static int arp_in(FAR struct net_driver_s *dev)
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{
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FAR struct arp_hdr_s *arp = ARPBUF;
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in_addr_t ipaddr;
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if (dev->d_len < (sizeof(struct arp_hdr_s) + ETH_HDRLEN))
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{
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nerr("ERROR: Packet Too small\n");
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dev->d_len = 0;
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return -EINVAL;
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}
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dev->d_len = 0;
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ipaddr = net_ip4addr_conv32(arp->ah_dipaddr);
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#ifdef CONFIG_NET_ARP_ACD
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arp_acd_update(dev);
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#endif /* CONFIG_NET_ARP_ACD */
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switch (arp->ah_opcode)
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{
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case HTONS(ARP_REQUEST):
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ninfo("ARP request for IP %04lx\n", (unsigned long)ipaddr);
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/* ARP request. If it asked for our address, we send out a reply. */
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if (net_ipv4addr_cmp(ipaddr, dev->d_ipaddr))
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{
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FAR struct eth_hdr_s *eth = ETHBUF;
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/* First, we register the one who made the request in our ARP
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* table, since it is likely that we will do more communication
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* with this host in the future.
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*/
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arp_hdr_update(dev, arp->ah_sipaddr, arp->ah_shwaddr);
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arp->ah_opcode = HTONS(ARP_REPLY);
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memcpy(arp->ah_dhwaddr, arp->ah_shwaddr, ETHER_ADDR_LEN);
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memcpy(arp->ah_shwaddr, dev->d_mac.ether.ether_addr_octet,
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ETHER_ADDR_LEN);
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memcpy(eth->src, dev->d_mac.ether.ether_addr_octet,
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ETHER_ADDR_LEN);
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memcpy(eth->dest, arp->ah_dhwaddr, ETHER_ADDR_LEN);
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arp->ah_dipaddr[0] = arp->ah_sipaddr[0];
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arp->ah_dipaddr[1] = arp->ah_sipaddr[1];
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net_ipv4addr_hdrcopy(arp->ah_sipaddr, &dev->d_ipaddr);
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arp_dump(arp);
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eth->type = HTONS(ETHTYPE_ARP);
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dev->d_len = sizeof(struct arp_hdr_s) + ETH_HDRLEN;
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}
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break;
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case HTONS(ARP_REPLY):
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ninfo("ARP reply for IP %04lx\n", (unsigned long)ipaddr);
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/* ARP reply. We insert or update the ARP table if it was meant
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* for us.
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*/
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if (net_ipv4addr_cmp(ipaddr, dev->d_ipaddr))
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{
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/* Yes... Insert the address mapping in the ARP table */
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arp_hdr_update(dev, arp->ah_sipaddr, arp->ah_shwaddr);
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/* Then notify any logic waiting for the ARP result */
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arp_notify(net_ip4addr_conv32(arp->ah_sipaddr));
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}
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break;
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}
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return OK;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: arp_input
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*
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* Description:
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* This function should be called by the Ethernet device driver when an
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* ARP packet has been received. The function will act differently
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* depending on the ARP packet type: if it is a reply for a request
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* that we previously sent out, the ARP cache will be filled in with
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* the values from the ARP reply. If the incoming ARP packet is an ARP
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* request for our IP address, an ARP reply packet is created and put
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* into the d_buf buffer.
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*
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* On entry, this function expects that an ARP packet with a prepended
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* Ethernet header is present in the d_buf buffer and that the length of
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* the packet is set in the d_len field.
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*
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* When the function returns, the value of the field d_len indicates
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* whether the device driver should send out the ARP reply packet or not.
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* If d_len is zero, no packet should be sent; If d_len is non-zero, it
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* contains the length of the outbound packet that is present in the
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* d_buf buffer.
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*
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****************************************************************************/
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void arp_input(FAR struct net_driver_s *dev)
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{
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FAR uint8_t *buf;
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if (dev->d_iob != NULL)
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{
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buf = dev->d_buf;
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/* Set the device buffer to l2 */
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dev->d_buf = NETLLBUF;
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arp_in(dev);
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dev->d_buf = buf;
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return;
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}
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netdev_input(dev, arp_in, true);
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}
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#endif /* CONFIG_NET_ARP */
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