commit e8d3d2991f72613edb76dea244a8c8e4684873dd
author Christian Franke <chris@opensourcerouting.org> Fri Jul 05 15:35:39 2013 +0000
committer David Lamparter <equinox@opensourcerouting.org> Thu Sep 19 18:04:40 2013 +0200
tree d02f768800ebaac51439368ff3d851e63ed6359e
parent 48a53dc71cb422e619859b79d5069e02fcd867d0

zebra: implement NEXTHOP_FLAG_ONLINK

On Linux, the kernel will only allow for a route to be installed when
its gateway is directly attached according the kernel fib.

There are cases when this restriction by the kernel is too strong, in
those cases, we deploy the RTNH_F_ONLINK netlink flag.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

zebra/rt_netlink.c

diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index b0ade05..7a820bf 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -1443,8 +1443,11 @@
         int bytelen,
         struct nexthop *nexthop,
         struct nlmsghdr *nlmsg,
+        struct rtmsg *rtmsg,
         size_t req_size)
 {
+  if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ONLINK))
+    rtmsg->rtm_flags |= RTNH_F_ONLINK;
   if (nexthop->type == NEXTHOP_TYPE_IPV4
       || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX)
     {
@@ -1534,6 +1537,9 @@
   rtnh->rtnh_hops = 0;
   rta->rta_len += rtnh->rtnh_len;
 
+  if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ONLINK))
+    rtnh->rtnh_flags |= RTNH_F_ONLINK;
+
   if (nexthop->type == NEXTHOP_TYPE_IPV4
       || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX)
     {
@@ -1733,7 +1739,8 @@
 
               _netlink_route_debug(cmd, p, nexthop, routedesc, family);
               _netlink_route_build_singlepath(routedesc, bytelen,
-                                              nexthop, &req.n, sizeof req);
+                                              nexthop, &req.n, &req.r,
+                                              sizeof req);
 
               if (cmd == RTM_NEWROUTE)
                 SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);