/************************************************************************
* NAME: fnet_netif_set_pmtu
* RETURS: None.
* DESCRIPTION: Sets PMTU of the interface.
*************************************************************************/
void fnet_netif_set_pmtu(fnet_netif_t *netif, unsigned long pmtu)
{
/* Set Path MTU for the link. */
netif->pmtu = pmtu;
netif->pmtu_timestamp = fnet_timer_ms();
}
/************************************************************************
* NAME: fnet_nd6_dad_timer
* RETURS: None.
* DESCRIPTION: Timer routine used to detect increase of PMTU
*************************************************************************/
static void fnet_netif_pmtu_timer( void *cookie )
{
fnet_netif_t *netif = (fnet_netif_t *)cookie;
if( fnet_timer_get_interval(netif->pmtu_timestamp, fnet_timer_ms()) > FNET_NETIF_PMTU_TIMEOUT)
{
fnet_netif_set_pmtu(netif, netif->mtu);
}
}
/************************************************************************
* NAME: fnet_eth_output_ip6
*
* DESCRIPTION: Ethernet IPv6 output function.
*************************************************************************/
void fnet_eth_output_ip6(fnet_netif_t *netif, const fnet_ip6_addr_t *src_ip_addr, const fnet_ip6_addr_t *dest_ip_addr, fnet_netbuf_t *nb)
{
fnet_mac_addr_t dest_mac_addr; /* 48-bit destination address */
fnet_uint8_t *dest_mac_addr_ptr;
/********************************************
* Multicast.
********************************************/
if (FNET_IP6_ADDR_IS_MULTICAST(dest_ip_addr))
{
FNET_ETH_MULTICAST_IP6_TO_MAC(dest_ip_addr, dest_mac_addr);
dest_mac_addr_ptr = (fnet_uint8_t *)dest_mac_addr;
}
/********************************************
* Unicast.
********************************************/
else
{
fnet_nd6_neighbor_entry_t *neighbor;
/* Possible redirection.*/
fnet_nd6_redirect_addr(netif, &dest_ip_addr);
/* Check Neigbor cache.*/
neighbor = fnet_nd6_neighbor_cache_get(netif, dest_ip_addr);
/* RFC4861 7.2.2: When a node has a unicast packet to send to a neighbor, but does not
* know the neighbor’s link-layer address, it performs address resolution.
* For multicast-capable interfaces, this entails creating a
* Neighbor Cache entry in the INCOMPLETE state and transmitting a
* Neighbor Solicitation message targeted at the neighbor. The
* solicitation is sent to the solicited-node multicast address
* corresponding to the target address.
*/
if(neighbor == FNET_NULL)
{
/* RFC4861 7.2.Address resolution is performed only on addresses that are determined to be
* on-link and for which the sender does not know the corresponding link-layer address.
* Address resolution is never performed on multicast addresses.*/
if(fnet_nd6_addr_is_onlink(netif, dest_ip_addr) == FNET_TRUE)
/* Destimnation is ON local-link.*/
{
/* Creating a Neighbor Cache entry in the INCOMPLETE state. */
neighbor = fnet_nd6_neighbor_cache_add(netif, dest_ip_addr, FNET_NULL, FNET_ND6_NEIGHBOR_STATE_INCOMPLETE);
neighbor->state_time = fnet_timer_ms();
neighbor->solicitation_send_counter = 0u;
FNET_IP6_ADDR_COPY(src_ip_addr, &neighbor->solicitation_src_ip_addr); /* Save src address for later usage.*/
/* AR: Transmitting a Neighbor Solicitation message targeted at the neighbor.*/
fnet_nd6_neighbor_solicitation_send(netif, src_ip_addr, FNET_NULL /* NULL for AR */, dest_ip_addr);
}
/* Destination is OFF local-link.*/
else
{
/* Try to use the router, if exists.*/
neighbor = fnet_nd6_default_router_get(netif);
if(neighbor == FNET_NULL)
/* No Router exists.*/
{
fnet_netbuf_free_chain(nb); /* Discard datagram */
goto EXIT;
}
dest_ip_addr = &neighbor->ip_addr; /* Chage destination address to the router one */
}
}
/* Link -layer address is not initialized.*/
if((neighbor->state != FNET_ND6_NEIGHBOR_STATE_INCOMPLETE)
&& (neighbor->ll_addr[0] == 0U) && (neighbor->ll_addr[1] == 0U) && (neighbor->ll_addr[2] == 0U)
&& (neighbor->ll_addr[3] == 0U) && (neighbor->ll_addr[4] == 0U) && (neighbor->ll_addr[5] == 0U) )
{
neighbor->state = FNET_ND6_NEIGHBOR_STATE_INCOMPLETE;
neighbor->state_time = fnet_timer_ms();
neighbor->solicitation_send_counter = 0u;
FNET_IP6_ADDR_COPY(src_ip_addr, &neighbor->solicitation_src_ip_addr); /* Save src address for later usage.*/
/* AR: Transmitting a Neighbor Solicitation message targeted at the neighbor.*/
fnet_nd6_neighbor_solicitation_send(netif, src_ip_addr, FNET_NULL /* NULL for AR */, dest_ip_addr);
}
if(neighbor->state == FNET_ND6_NEIGHBOR_STATE_INCOMPLETE)
/* Queue packet for later transmit.
*/
{
fnet_nd6_neighbor_enqueue_waiting_netbuf(neighbor, nb);
goto EXIT;
}
if(neighbor->state == FNET_ND6_NEIGHBOR_STATE_STALE)
/* RFC4861 7.3.3: The first time a node sends a packet to a neighbor whose entry is
* STALE, the sender changes the state to DELAY and sets a timer to
* expire in DELAY_FIRST_PROBE_TIME seconds.
*/
{
neighbor->state = FNET_ND6_NEIGHBOR_STATE_DELAY;
neighbor->state_time = fnet_timer_ms();
}
/* Get destination MAC/HW address.*/
dest_mac_addr_ptr = (fnet_uint8_t *)(&neighbor->ll_addr[0]);
}
/* Send Ethernet frame. */
fnet_eth_output(netif, FNET_ETH_TYPE_IP6, dest_mac_addr_ptr, nb);
EXIT:
return;
}
