nl_l3::del_l3_unicast_route(): delete nh_unreach notifications

When deleting a route, we need to make sure to also remove any
next unreachable notifications we did, else we may call del_l3_neigh too
often.

Fixes: 590c33d ("nl_l3: handle neigh unreachable * Adds nh unreachable container to track nexthop unreachability changes * In case that nexthop is not anymore reachable, update route that has nexthop to point to controller and delete the reference * Thus, when NH becomes again reachable, we can update the egress reference and the route")
Signed-off-by: Jonas Gorski <jonas.gorski@bisdn.de>

src/netlink/nl_l3.cc

@@ -2022,7 +2022,6 @@ int nl_l3::del_l3_unicast_route(rtnl_route *r, bool keep_route) {
       auto vid = vlan->get_vid(link.get());
 
       struct nl_addr *s_mac = rtnl_link_get_addr(link.get());
-      struct nl_addr *d_mac = rtnl_neigh_get_lladdr(n);
 
       // For the Bridge SVI, the l3 interface already exists
       // so we can just get that one
@@ -2055,6 +2054,20 @@ int nl_l3::del_l3_unicast_route(rtnl_route *r, bool keep_route) {
 
   // remove egress references
   for (auto n : neighs) {
+    int ifindex = rtnl_neigh_get_ifindex(n);
+    struct nl_addr *addr = rtnl_neigh_get_dst(n);
+
+    auto it =
+        std::find_if(nh_unreach_callbacks.begin(), nh_unreach_callbacks.end(),
+                     [&](std::pair<nh_unreachable *, nh_params> &cb) {
+                       return cb.first == this &&
+                              cb.second.nh.ifindex == ifindex &&
+                              !nl_addr_cmp(cb.second.nh.nh, addr) &&
+                              !nl_addr_cmp(cb.second.np.addr, dst);
+                     });
+
+    if (it != nh_unreach_callbacks.end())
+      nh_unreach_callbacks.erase(it);
     rv = del_l3_neigh_egress(n);
 
     if (rv < 0 and rv != -EEXIST) {