nd6: add LWIP_HOOK_ND6_GET_GW hook
diff --git a/src/core/ipv6/nd6.c b/src/core/ipv6/nd6.c
index 82394f6..e555321 100644
--- a/src/core/ipv6/nd6.c
+++ b/src/core/ipv6/nd6.c
@@ -1524,6 +1524,9 @@
s8_t
nd6_get_next_hop_entry(const ip6_addr_t *ip6addr, struct netif *netif)
{
+#ifdef LWIP_HOOK_ND6_GET_GW
+ const ip6_addr_t *next_hop_addr;
+#endif /* LWIP_HOOK_ND6_GET_GW */
s8_t i;
#if LWIP_NETIF_HWADDRHINT
@@ -1567,6 +1570,12 @@
/* Destination in local link. */
destination_cache[nd6_cached_destination_index].pmtu = netif->mtu;
ip6_addr_copy(destination_cache[nd6_cached_destination_index].next_hop_addr, destination_cache[nd6_cached_destination_index].destination_addr);
+#ifdef LWIP_HOOK_ND6_GET_GW
+ } else if ((next_hop_addr = LWIP_HOOK_ND6_GET_GW(netif, ip6addr)) != NULL) {
+ /* Next hop for destination provided by hook function. */
+ destination_cache[nd6_cached_destination_index].pmtu = netif->mtu;
+ ip6_addr_set(&destination_cache[nd6_cached_destination_index].next_hop_addr, next_hop_addr);
+#endif /* LWIP_HOOK_ND6_GET_GW */
} else {
/* We need to select a router. */
i = nd6_select_router(ip6addr, netif);
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 304609b..336b77e 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -2470,6 +2470,22 @@
#endif
/**
+ * LWIP_HOOK_ND6_GET_GW(netif, dest):
+ * - called from nd6_get_next_hop_entry() (IPv6)
+ * - netif: the netif used for sending
+ * - dest: the destination IPv6 address
+ * Returns the IPv6 address of the next hop to handle the specified destination
+ * IPv6 address. If NULL is returned, a NDP-discovered router is used instead.
+ * The returned address MUST be reachable on the specified netif!
+ * This function is meant to implement advanced IPv6 routing together with
+ * LWIP_HOOK_IP6_ROUTE(). The actual routing/gateway table implementation is
+ * not part of lwIP but can e.g. be hidden in the netif's state argument.
+*/
+#ifdef __DOXYGEN__
+#define LWIP_HOOK_ND6_GET_GW(netif, dest)
+#endif
+
+/**
* LWIP_HOOK_VLAN_CHECK(netif, eth_hdr, vlan_hdr):
* - called from ethernet_input() if VLAN support is enabled
* - netif: struct netif on which the packet has been received
