/**
* Resolve and fill-in Ethernet address header for outgoing IPv6 packet.
*
* For IPv6 multicast, corresponding Ethernet addresses
* are selected and the packet is transmitted on the link.
*
* For unicast addresses, ...
*
* @todo anycast addresses
*
* @param netif The lwIP network interface which the IP packet will be sent on.
* @param q The pbuf(s) containing the IP packet to be sent.
* @param ip6addr The IP address of the packet destination.
*
* @return
* - ERR_RTE No route to destination (no gateway to external networks),
* or the return type of either nd6_queue_packet() or ethernet_output().
*/
err_t
ethip6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
{
struct eth_addr dest;
s8_t i;
/* multicast destination IP address? */
if (ip6_addr_ismulticast(ip6addr)) {
/* Hash IP multicast address to MAC address.*/
dest.addr[0] = 0x33;
dest.addr[1] = 0x33;
dest.addr[2] = ((const u8_t *)(&(ip6addr->addr[3])))[0];
dest.addr[3] = ((const u8_t *)(&(ip6addr->addr[3])))[1];
dest.addr[4] = ((const u8_t *)(&(ip6addr->addr[3])))[2];
dest.addr[5] = ((const u8_t *)(&(ip6addr->addr[3])))[3];
/* Send out. */
return ethernet_output(netif, q, (struct eth_addr*)(netif->hwaddr), &dest, ETHTYPE_IPV6);
}
/* We have a unicast destination IP address */
/* @todo anycast? */
/* Get next hop record. */
i = nd6_get_next_hop_entry(ip6addr, netif);
if (i < 0) {
/* failed to get a next hop neighbor record. */
return ERR_MEM;
}
/* Now that we have a destination record, send or queue the packet. */
if (neighbor_cache[i].state == ND6_STALE) {
/* Switch to delay state. */
neighbor_cache[i].state = ND6_DELAY;
neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME / ND6_TMR_INTERVAL;
}
/* @todo should we send or queue if PROBE? send for now, to let unicast NS pass. */
if ((neighbor_cache[i].state == ND6_REACHABLE) ||
(neighbor_cache[i].state == ND6_DELAY) ||
(neighbor_cache[i].state == ND6_PROBE)) {
/* Send out. */
SMEMCPY(dest.addr, neighbor_cache[i].lladdr, 6);
return ethernet_output(netif, q, (struct eth_addr*)(netif->hwaddr), &dest, ETHTYPE_IPV6);
}
/* We should queue packet on this interface. */
return nd6_queue_packet(i, q);
}
/**
* Update (or insert) a IP/MAC address pair in the ARP cache.
*
* If a pending entry is resolved, any queued packets will be sent
* at this point.
*
* @param netif netif related to this entry (used for NETIF_ADDRHINT)
* @param ipaddr IP address of the inserted ARP entry.
* @param ethaddr Ethernet address of the inserted ARP entry.
* @param flags See @ref etharp_state
*
* @return
* - ERR_OK Successfully updated ARP cache.
* - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set.
* - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
*
* @see pbuf_free()
*/
static err_t
etharp_update_arp_entry(struct netif *netif, const ip4_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags)
{
s8_t i;
LWIP_ASSERT("netif->hwaddr_len == ETH_HWADDR_LEN", netif->hwaddr_len == ETH_HWADDR_LEN);
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n",
ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
(u16_t)ethaddr->addr[0], (u16_t)ethaddr->addr[1], (u16_t)ethaddr->addr[2],
(u16_t)ethaddr->addr[3], (u16_t)ethaddr->addr[4], (u16_t)ethaddr->addr[5]));
/* non-unicast address? */
if (ip4_addr_isany(ipaddr) ||
ip4_addr_isbroadcast(ipaddr, netif) ||
ip4_addr_ismulticast(ipaddr)) {
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: will not add non-unicast IP address to ARP cache\n"));
return ERR_ARG;
}
/* find or create ARP entry */
i = etharp_find_entry(ipaddr, flags, netif);
/* bail out if no entry could be found */
if (i < 0) {
return (err_t)i;
}
#if ETHARP_SUPPORT_STATIC_ENTRIES
if (flags & ETHARP_FLAG_STATIC_ENTRY) {
/* record static type */
arp_table[i].state = ETHARP_STATE_STATIC;
} else if (arp_table[i].state == ETHARP_STATE_STATIC) {
/* found entry is a static type, don't overwrite it */
return ERR_VAL;
} else
#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
{
/* mark it stable */
arp_table[i].state = ETHARP_STATE_STABLE;
}
/* record network interface */
arp_table[i].netif = netif;
/* insert in SNMP ARP index tree */
mib2_add_arp_entry(netif, &arp_table[i].ipaddr);
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i));
/* update address */
ETHADDR32_COPY(&arp_table[i].ethaddr, ethaddr);
/* reset time stamp */
arp_table[i].ctime = 0;
/* this is where we will send out queued packets! */
#if ARP_QUEUEING
while (arp_table[i].q != NULL) {
struct pbuf *p;
/* remember remainder of queue */
struct etharp_q_entry *q = arp_table[i].q;
/* pop first item off the queue */
arp_table[i].q = q->next;
/* get the packet pointer */
p = q->p;
/* now queue entry can be freed */
memp_free(MEMP_ARP_QUEUE, q);
#else /* ARP_QUEUEING */
if (arp_table[i].q != NULL) {
struct pbuf *p = arp_table[i].q;
arp_table[i].q = NULL;
#endif /* ARP_QUEUEING */
/* send the queued IP packet */
ethernet_output(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr, ETHTYPE_IP);
/* free the queued IP packet */
pbuf_free(p);
}
return ERR_OK;
}
#if ETHARP_SUPPORT_STATIC_ENTRIES
/** Add a new static entry to the ARP table. If an entry exists for the
* specified IP address, this entry is overwritten.
* If packets are queued for the specified IP address, they are sent out.
*
* @param ipaddr IP address for the new static entry
* @param ethaddr ethernet address for the new static entry
* @return See return values of etharp_add_static_entry
*/
err_t
etharp_add_static_entry(const ip4_addr_t *ipaddr, struct eth_addr *ethaddr)
{
struct netif *netif;
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_add_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n",
ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
(u16_t)ethaddr->addr[0], (u16_t)ethaddr->addr[1], (u16_t)ethaddr->addr[2],
(u16_t)ethaddr->addr[3], (u16_t)ethaddr->addr[4], (u16_t)ethaddr->addr[5]));
netif = ip4_route(ipaddr);
if (netif == NULL) {
return ERR_RTE;
}
return etharp_update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD | ETHARP_FLAG_STATIC_ENTRY);
}
/** Remove a static entry from the ARP table previously added with a call to
* etharp_add_static_entry.
*
* @param ipaddr IP address of the static entry to remove
* @return ERR_OK: entry removed
* ERR_MEM: entry wasn't found
* ERR_ARG: entry wasn't a static entry but a dynamic one
*/
err_t
etharp_remove_static_entry(const ip4_addr_t *ipaddr)
{
s8_t i;
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
/* find or create ARP entry */
i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY, NULL);
/* bail out if no entry could be found */
if (i < 0) {
return (err_t)i;
}
if (arp_table[i].state != ETHARP_STATE_STATIC) {
/* entry wasn't a static entry, cannot remove it */
return ERR_ARG;
}
/* entry found, free it */
etharp_free_entry(i);
return ERR_OK;
}
