Re: [PATCH net] net: ipv4: Multipath needs to handle unreachable nexthops
From: Eric Dumazet <hidden>
Date: 2016-03-24 16:45:36
On Thu, 2016-03-24 at 08:25 -0700, David Ahern wrote:
Multipath route lookups should consider knowledge about next hops and not select a hop that is known to be failed.
Does not look a net candidate to me.
quoted hunk ↗ jump to hunk
Signed-off-by: David Ahern <redacted> --- net/ipv4/fib_semantics.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-)diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index d97268e8ff10..28fc6700c2b1 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c@@ -1563,13 +1563,43 @@ int fib_sync_up(struct net_device *dev, unsigned int nh_flags) void fib_select_multipath(struct fib_result *res, int hash) { struct fib_info *fi = res->fi; + struct neighbour *n; + int state; for_nexthops(fi) { if (hash > atomic_read(&nh->nh_upper_bound)) continue; - res->nh_sel = nhsel; - return; + state = NUD_NONE; + n = neigh_lookup(&arp_tbl, &nh->nh_gw, fi->fib_dev); + if (n) { + state = n->nud_state; + neigh_release(n); + }
This looks like something that could use RCU to avoid expensive refcounting ?