From 4ffab13eeb6ab72a21557797c0343df7961a80db Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sun, 10 Dec 2017 06:55:28 -0800
Subject: [PATCH] Routing API: drop_route

---
 os/net/ipv6/tcpip.c                      | 25 +++++-------------------
 os/net/ipv6/uip-ds6-route.h              |  1 -
 os/net/routing/nullrouting/nullrouting.c |  6 ++++++
 os/net/routing/routing.h                 |  6 ++++++
 os/net/routing/rpl-classic/rpl.c         | 13 ++++++++++++
 os/net/routing/rpl-lite/rpl.c            |  7 +++++++
 6 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/os/net/ipv6/tcpip.c b/os/net/ipv6/tcpip.c
index 903498532..eec3068ad 100644
--- a/os/net/ipv6/tcpip.c
+++ b/os/net/ipv6/tcpip.c
@@ -476,23 +476,6 @@ output_fallback(void)
 }
 /*---------------------------------------------------------------------------*/
 static void
-drop_route(uip_ds6_route_t *route)
-{
-#if UIP_CONF_IPV6_RPL && (UIP_CONF_IPV6_RPL_LITE == 0)
-
-  /* If we are running RPL, and if we are the root of the
-     network, we'll trigger a global repair before we remove
-     the route. */
-  rpl_dag_t *dag;
-  dag = (rpl_dag_t *)route->state.dag;
-  if(dag != NULL && dag->instance != NULL) {
-    rpl_repair_root(dag->instance->instance_id);
-  }
-#endif /* UIP_CONF_IPV6_RPL && (UIP_CONF_IPV6_RPL_LITE == 0) */
-  uip_ds6_route_rm(route);
-}
-/*---------------------------------------------------------------------------*/
-static void
 annotate_transmission(uip_ipaddr_t *nexthop)
 {
 #if TCPIP_CONF_ANNOTATE_TRANSMISSIONS
@@ -558,9 +541,11 @@ get_nexthop(uip_ipaddr_t *addr)
        never responded to link-layer acks, we drop its route. */
     if(nexthop == NULL) {
       LOG_ERR("output: found dead route\n");
-      drop_route(route);
-      /* We don't have a nexthop to send the packet to, so we drop
-         it. */
+      /* Notifiy the routing protocol that we are about to remove the route */
+      NETSTACK_ROUTING.drop_route(route);
+      /* Remove the route */
+      uip_ds6_route_rm(route);
+      /* We don't have a nexthop to send the packet to, so we drop it. */
     } else {
       LOG_INFO("output: found next hop from routing table: ");
       LOG_INFO_6ADDR(nexthop);
diff --git a/os/net/ipv6/uip-ds6-route.h b/os/net/ipv6/uip-ds6-route.h
index 8f2bc377d..663f0ad50 100644
--- a/os/net/ipv6/uip-ds6-route.h
+++ b/os/net/ipv6/uip-ds6-route.h
@@ -44,7 +44,6 @@
 #include "net/nbr-table.h"
 #include "sys/stimer.h"
 #include "lib/list.h"
-#include "net/routing/routing.h"
 
 #ifdef UIP_CONF_MAX_ROUTES
 #define UIP_MAX_ROUTES UIP_CONF_MAX_ROUTES
diff --git a/os/net/routing/nullrouting/nullrouting.c b/os/net/routing/nullrouting/nullrouting.c
index 5707143b1..e341225f9 100644
--- a/os/net/routing/nullrouting/nullrouting.c
+++ b/os/net/routing/nullrouting/nullrouting.c
@@ -103,6 +103,11 @@ link_callback(const linkaddr_t *addr, int status, int numtx)
 {
 }
 /*---------------------------------------------------------------------------*/
+static void
+drop_route(uip_ds6_route_t *route)
+{
+}
+/*---------------------------------------------------------------------------*/
 const struct routing_driver nullrouting_driver = {
   "Null Routing",
   init,
@@ -116,6 +121,7 @@ const struct routing_driver nullrouting_driver = {
   ext_header_srh_update,
   ext_header_srh_get_next_hop,
   link_callback,
+  drop_route,
 };
 /*---------------------------------------------------------------------------*/
 
diff --git a/os/net/routing/routing.h b/os/net/routing/routing.h
index fa0e301af..330269826 100644
--- a/os/net/routing/routing.h
+++ b/os/net/routing/routing.h
@@ -118,6 +118,12 @@ struct routing_driver {
    * \param numtx The total number of transmission attempts
    */
   void (* link_callback)(const linkaddr_t *addr, int status, int numtx);
+  /**
+   * Called by uIP if it has decided to drop a route because
+   *
+   * \param route The route that will be dropped after this function returns
+   */
+  void (* drop_route)(uip_ds6_route_t *route);
 };
 
 #endif /* ROUTING_H_ */
diff --git a/os/net/routing/rpl-classic/rpl.c b/os/net/routing/rpl-classic/rpl.c
index 6fa041eba..a649e247c 100644
--- a/os/net/routing/rpl-classic/rpl.c
+++ b/os/net/routing/rpl-classic/rpl.c
@@ -371,6 +371,18 @@ local_repair(const char *str)
   }
 }
 /*---------------------------------------------------------------------------*/
+static void
+drop_route(uip_ds6_route_t *route)
+{
+  /* If we are the root of the network, trigger a global repair before
+  the route gets removed */
+  rpl_dag_t *dag;
+  dag = (rpl_dag_t *)route->state.dag;
+  if(dag != NULL && dag->instance != NULL) {
+    rpl_repair_root(dag->instance->instance_id);
+  }
+}
+/*---------------------------------------------------------------------------*/
 const struct routing_driver rpl_classic_driver = {
   "RPL Classic",
   init,
@@ -384,6 +396,7 @@ const struct routing_driver rpl_classic_driver = {
   rpl_ext_header_srh_update,
   rpl_ext_header_srh_get_next_hop,
   rpl_link_callback,
+  drop_route,
 };
 /*---------------------------------------------------------------------------*/
 
diff --git a/os/net/routing/rpl-lite/rpl.c b/os/net/routing/rpl-lite/rpl.c
index fe4f87684..dc1c123f2 100644
--- a/os/net/routing/rpl-lite/rpl.c
+++ b/os/net/routing/rpl-lite/rpl.c
@@ -193,6 +193,12 @@ init(void)
   rpl_ns_init();
 }
 /*---------------------------------------------------------------------------*/
+static void
+drop_route(uip_ds6_route_t *route)
+{
+  /* Do nothing. RPL-lite only supports non-storing mode, i.e. no routes */
+}
+/*---------------------------------------------------------------------------*/
 const struct routing_driver rpl_lite_driver = {
   "RPL Lite",
   init,
@@ -206,6 +212,7 @@ const struct routing_driver rpl_lite_driver = {
   rpl_ext_header_srh_update,
   rpl_ext_header_srh_get_next_hop,
   rpl_link_callback,
+  drop_route,
 };
 /*---------------------------------------------------------------------------*/