281 lines
9.3 KiB
C
281 lines
9.3 KiB
C
/****************************************************************************
|
|
* net/arp/arp_out.c
|
|
*
|
|
* Copyright (C) 2007-2011, 2014-2015, 2017-2018 Gregory Nutt. All rights
|
|
* reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* Based on uIP which also has a BSD style license:
|
|
*
|
|
* Author: Adam Dunkels <adam@dunkels.com>
|
|
* Copyright (c) 2001-2003, Adam Dunkels.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. The name of the author may not be used to endorse or promote
|
|
* products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
|
|
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
|
|
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
|
|
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
|
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <string.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/net/netdev.h>
|
|
#include <nuttx/net/arp.h>
|
|
|
|
#include "route/route.h"
|
|
#include "arp/arp.h"
|
|
|
|
#ifdef CONFIG_NET_ARP
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define ETHBUF ((struct eth_hdr_s *)&dev->d_buf[0])
|
|
#define ARPBUF ((struct arp_hdr_s *)&dev->d_buf[ETH_HDRLEN])
|
|
#define IPBUF ((struct arp_iphdr_s *)&dev->d_buf[ETH_HDRLEN])
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
/* Support for broadcast address */
|
|
|
|
static const struct ether_addr g_broadcast_ethaddr =
|
|
{
|
|
{
|
|
0xff, 0xff, 0xff, 0xff, 0xff, 0xff
|
|
}
|
|
};
|
|
|
|
static const uint16_t g_broadcast_ipaddr[2] =
|
|
{
|
|
0xffff, 0xffff
|
|
};
|
|
|
|
/* Support for IGMP multicast addresses.
|
|
*
|
|
* Well-known ethernet multicast address:
|
|
*
|
|
* ADDRESS TYPE USAGE
|
|
* 01-00-0c-cc-cc-cc 0x0802 CDP (Cisco Discovery Protocol), VTP (Virtual Trunking Protocol)
|
|
* 01-00-0c-cc-cc-cd 0x0802 Cisco Shared Spanning Tree Protocol Address
|
|
* 01-80-c2-00-00-00 0x0802 Spanning Tree Protocol (for bridges) IEEE 802.1D
|
|
* 01-80-c2-00-00-02 0x0809 Ethernet OAM Protocol IEEE 802.3ah
|
|
* 01-00-5e-xx-xx-xx 0x0800 IPv4 IGMP Multicast Address
|
|
* 33-33-00-00-00-00 0x86DD IPv6 Neighbor Discovery
|
|
* 33-33-xx-xx-xx-xx 0x86DD IPv6 Multicast Address (RFC3307)
|
|
*
|
|
* The following is the first three octects of the IGMP address:
|
|
*/
|
|
|
|
#ifdef CONFIG_NET_IGMP
|
|
static const uint8_t g_multicast_ethaddr[3] =
|
|
{
|
|
0x01, 0x00, 0x5e
|
|
};
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: arp_out
|
|
*
|
|
* Description:
|
|
* This function should be called before sending out an IP packet. The
|
|
* function checks the destination IP address of the IP packet to see
|
|
* what Ethernet MAC address that should be used as a destination MAC
|
|
* address on the Ethernet.
|
|
*
|
|
* If the destination IP address is in the local network (determined
|
|
* by logical ANDing of netmask and our IP address), the function
|
|
* checks the ARP cache to see if an entry for the destination IP
|
|
* address is found. If so, an Ethernet header is pre-pended at the
|
|
* beginning of the packet and the function returns.
|
|
*
|
|
* If no ARP cache entry is found for the destination IP address, the
|
|
* packet in the d_buf is replaced by an ARP request packet for the
|
|
* IP address. The IP packet is dropped and it is assumed that the
|
|
* higher level protocols (e.g., TCP) eventually will retransmit the
|
|
* dropped packet.
|
|
*
|
|
* Upon return in either the case, a packet to be sent is present in the
|
|
* d_buf buffer and the d_len field holds the length of the Ethernet
|
|
* frame that should be transmitted.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void arp_out(FAR struct net_driver_s *dev)
|
|
{
|
|
struct ether_addr ethaddr;
|
|
FAR struct eth_hdr_s *peth = ETHBUF;
|
|
FAR struct arp_iphdr_s *pip = IPBUF;
|
|
in_addr_t ipaddr;
|
|
in_addr_t destipaddr;
|
|
int ret;
|
|
|
|
#if defined(CONFIG_NET_PKT) || defined(CONFIG_NET_ARP_SEND)
|
|
/* Skip sending ARP requests when the frame to be transmitted was
|
|
* written into a packet socket.
|
|
*/
|
|
|
|
if (IFF_IS_NOARP(dev->d_flags))
|
|
{
|
|
/* Clear the indication and let the packet continue on its way. */
|
|
|
|
IFF_CLR_NOARP(dev->d_flags);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
/* Find the destination IP address in the ARP table and construct
|
|
* the Ethernet header. If the destination IP address isn't on the
|
|
* local network, we use the default router's IP address instead.
|
|
*
|
|
* If not ARP table entry is found, we overwrite the original IP
|
|
* packet with an ARP request for the IP address.
|
|
*/
|
|
|
|
/* First check if destination is a local broadcast. */
|
|
|
|
if (net_ipv4addr_hdrcmp(pip->eh_destipaddr, g_broadcast_ipaddr))
|
|
{
|
|
memcpy(peth->dest, g_broadcast_ethaddr.ether_addr_octet, ETHER_ADDR_LEN);
|
|
goto finish_header;
|
|
}
|
|
|
|
#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 (NTOHS(pip->eh_destipaddr[0]) >= 0xe000 &&
|
|
NTOHS(pip->eh_destipaddr[0]) <= 0xefff)
|
|
{
|
|
/* Build the well-known IPv4 IGMP Ethernet address. The first
|
|
* three bytes are fixed; the final three variable come from the
|
|
* last three bytes of the IPv4 address (network order).
|
|
*
|
|
* Address range : 01:00:5e:00:00:00 to 01:00:5e:7f:ff:ff
|
|
*/
|
|
|
|
FAR const uint8_t *ip = (FAR uint8_t *)pip->eh_destipaddr;
|
|
|
|
peth->dest[0] = g_multicast_ethaddr[0];
|
|
peth->dest[1] = g_multicast_ethaddr[1];
|
|
peth->dest[2] = g_multicast_ethaddr[2];
|
|
peth->dest[3] = ip[1] & 0x7f;
|
|
peth->dest[4] = ip[2];
|
|
peth->dest[5] = ip[3];
|
|
|
|
goto finish_header;
|
|
}
|
|
#endif
|
|
|
|
/* Check if the destination address is on the local network. */
|
|
|
|
destipaddr = net_ip4addr_conv32(pip->eh_destipaddr);
|
|
if (!net_ipv4addr_maskcmp(destipaddr, dev->d_ipaddr, dev->d_netmask))
|
|
{
|
|
/* 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, destipaddr, &ipaddr);
|
|
#else
|
|
/* Use the device's default router IP address instead of the
|
|
* destination address when determining the MAC address.
|
|
*/
|
|
|
|
net_ipv4addr_copy(ipaddr, dev->d_draddr);
|
|
#endif
|
|
}
|
|
|
|
/* The destination address is on the local network. Check if it is
|
|
* the sub-net broadcast address.
|
|
*/
|
|
|
|
else if (net_ipv4addr_broadcast(destipaddr, dev->d_netmask))
|
|
{
|
|
/* Yes.. then we won't need to know the destination MAC address */
|
|
|
|
memcpy(peth->dest, g_broadcast_ethaddr.ether_addr_octet, ETHER_ADDR_LEN);
|
|
goto finish_header;
|
|
}
|
|
else
|
|
{
|
|
/* Else, we use the destination IP address. */
|
|
|
|
net_ipv4addr_copy(ipaddr, destipaddr);
|
|
}
|
|
|
|
/* Check if we already have this destination address in the ARP table */
|
|
|
|
ret = arp_find(ipaddr, ðaddr);
|
|
if (ret < 0)
|
|
{
|
|
ninfo("ARP request for IP %08lx\n", (unsigned long)ipaddr);
|
|
|
|
/* The destination address was not in our ARP table, so we overwrite
|
|
* the IP packet with an ARP request.
|
|
*/
|
|
|
|
arp_format(dev, ipaddr);
|
|
arp_dump(ARPBUF);
|
|
return;
|
|
}
|
|
|
|
/* Build an Ethernet header. */
|
|
|
|
memcpy(peth->dest, ethaddr.ether_addr_octet, ETHER_ADDR_LEN);
|
|
|
|
/* Finish populating the Ethernet header */
|
|
|
|
finish_header:
|
|
memcpy(peth->src, dev->d_mac.ether.ether_addr_octet, ETHER_ADDR_LEN);
|
|
peth->type = HTONS(ETHTYPE_IP);
|
|
dev->d_len += ETH_HDRLEN;
|
|
}
|
|
|
|
#endif /* CONFIG_NET_ARP */
|