Merge tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...

[deliverable/linux.git] / net / ipv4 / fib_semantics.c

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 2b68418c7198009e2477961c4b34503dc1439526..539fa264e67d71148364c9fc0e694c78fd35e69b 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -479,6 +479,9 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
                if (!rtnh_ok(rtnh, remaining))
                        return -EINVAL;
 
+               if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
+                       return -EINVAL;
+
                nexthop_nh->nh_flags =
                        (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
                nexthop_nh->nh_oif = rtnh->rtnh_ifindex;
@@ -1003,6 +1006,9 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
        if (fib_props[cfg->fc_type].scope > cfg->fc_scope)
                goto err_inval;
 
+       if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
+               goto err_inval;
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
        if (cfg->fc_mp) {
                nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len);
@@ -1561,21 +1567,45 @@ int fib_sync_up(struct net_device *dev, unsigned int nh_flags)
 }
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
+static bool fib_good_nh(const struct fib_nh *nh)
+{
+       int state = NUD_REACHABLE;
+
+       if (nh->nh_scope == RT_SCOPE_LINK) {
+               struct neighbour *n;
+
+               rcu_read_lock_bh();
+
+               n = __ipv4_neigh_lookup_noref(nh->nh_dev, nh->nh_gw);
+               if (n)
+                       state = n->nud_state;
+
+               rcu_read_unlock_bh();
+       }
+
+       return !!(state & NUD_VALID);
+}
 
 void fib_select_multipath(struct fib_result *res, int hash)
 {
        struct fib_info *fi = res->fi;
+       struct net *net = fi->fib_net;
+       bool first = false;
 
        for_nexthops(fi) {
                if (hash > atomic_read(&nh->nh_upper_bound))
                        continue;
 
-               res->nh_sel = nhsel;
-               return;
+               if (!net->ipv4.sysctl_fib_multipath_use_neigh ||
+                   fib_good_nh(nh)) {
+                       res->nh_sel = nhsel;
+                       return;
+               }
+               if (!first) {
+                       res->nh_sel = nhsel;
+                       first = true;
+               }
        } endfor_nexthops(fi);
-
-       /* Race condition: route has just become dead. */
-       res->nh_sel = 0;
 }
 #endif