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;
}
void neighbor_out(FAR struct net_driver_s *dev)
{
FAR const struct neighbor_addr_s *naddr;
FAR struct eth_hdr_s *eth = ETHBUF;
FAR struct ipv6_hdr_s *ip = IPv6BUF;
net_ipv6addr_t ipaddr;
/* Skip sending Neighbor Solicitations when the frame to be transmitted was
* written into a packet socket or if we are sending certain Neighbor
* messages (solicitation, advertisement, echo request).
*/
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;
}
/* Find the destination IPv6 address in the Neighbor Table and construct
* the Ethernet header. If the destination IPv6 address isn't on the local
* network, we use the default router's IPv6 address instead.
*
* If no Neighbor Table entry is found, we overwrite the original IPv6
* packet with an Neighbor Solicitation Request for the IPv6 address.
*/
/* First check if destination is a IPv6 multicast address. IPv6
* multicast addresses in IPv6 have the prefix ff00::/8
*
* Bits 120-127: Prefix
* Bits 116-119: Flags (1, 2, or 3 defined)
* Bits 112-115: Scope
*
* REVISIT: Need to revisit IPv6 broadcast support. Broadcast
* IP addresses are not used with IPv6; multicast is used instead.
* Does this mean that all multicast address should go to the
* broadcast Ethernet address?
*/
if ((ip->destipaddr[0] & HTONS(0xff00)) == HTONS(0xff00))
{
memcpy(eth->dest, g_broadcast_ethaddr.ether_addr_octet,
ETHER_ADDR_LEN);
}
#ifdef CONFIG_NET_IGMP
/* Check if the destination address is a multicast address
*
* IPv6 multicast addresses are have the high-order octet of the
* addresses=0xff (ff00::/8.)
*
* REVISIT: See comments above. How do we distinguish broadcast
* from IGMP multicast?
*/
#warning Missing logic
#endif
else
{
/* Check if the destination address is on the local network. */
if (!net_ipv6addr_maskcmp(ip->destipaddr, dev->d_ipv6addr,
dev->d_ipv6netmask))
{
/* 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 IPv6 address instead of the
* destination address when determining the MAC address.
*/
netdev_ipv6_router(dev, ip->destipaddr, ipaddr);
#else
/* Use the device's default router IPv6 address instead of the
* destination address when determining the MAC address.
*/
net_ipv6addr_copy(ipaddr, dev->d_ipv6draddr);
#endif
}
else
{
/* Else, we use the destination IPv6 address. */
net_ipv6addr_copy(ipaddr, ip->destipaddr);
}
/* Check if we already have this destination address in the Neighbor Table */
naddr = neighbor_lookup(ipaddr);
if (!naddr)
{
nllvdbg("IPv6 Neighbor solicitation for IPv6\n");
/* The destination address was not in our Neighbor Table, so we
* overwrite the IPv6 packet with an ICMDv6 Neighbor Solicitation
* message.
*/
icmpv6_solicit(dev, ipaddr);
return;
}
/* Build an Ethernet header. */
memcpy(eth->dest, naddr->na_addr.ether_addr_octet, ETHER_ADDR_LEN);
}
/* Finish populating the Ethernet header */
memcpy(eth->src, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
eth->type = HTONS(ETHTYPE_IP6);
/* Add the size of the layer layer header to the total size of the
* outgoing packet.
*/
dev->d_len += netdev_ipv6_hdrlen(dev);
nllvdbg("Outgoing IPv6 Packet length: %d (%d)\n",
dev->d_len, (ip->len[0] << 8) | ip->len[1]);
}