Hello,
I believe that there is a bug in neigh_create in linux-2.4.28 introduced by
neighbor cache backport from v2.6.9.
New neigh entry hash_val was calculated before possible hash growth. So it got
inserted in wrong place, making ARP entry (that was inserted immediately after
hash growth)
unresolvable until entry timeout.
It looked like this. The host did not answer to pings from some random host,
but it could ping it after that with no problems. And vice versa.
Raivis Bucis
diff -uNr linux-2.4.28.org/net/core/neighbour.c
linux-2.4.28/net/core/neighbour.c
--- linux-2.4.28.org/net/core/neighbour.c 2004-11-17 13:54:22.000000000 +0200
+++ linux-2.4.28/net/core/neighbour.c 2005-01-07 14:11:57.000000000 +0200
@@ -427,11 +427,12 @@
n->confirmed = jiffies - (n->parms->base_reachable_time<<1);
- hash_val = tbl->hash(pkey, dev) & tbl->hash_mask;
-
write_lock_bh(&tbl->lock);
if (atomic_read(&tbl->entries) > (tbl->hash_mask + 1))
neigh_hash_grow(tbl, (tbl->hash_mask + 1) << 1);
+
+ hash_val = tbl->hash(pkey, dev) & tbl->hash_mask;
+
for (n1 = tbl->hash_buckets[hash_val]; n1; n1 = n1->next) {
if (dev == n1->dev &&
memcmp(n1->primary_key, pkey, key_len) == 0) {
|