From 4ab6ad136b62add35598f3c354231701b7c14c65 Mon Sep 17 00:00:00 2001 From: Klement Sekera Date: Fri, 17 Dec 2021 12:47:51 +0000 Subject: ip: SVR fix race condition There could be a race condition where two fragments of one chain end up at the same time on different workers, one overwriting others hash entry. Add a check for that and restart processing on the unlucky worker who ends up being second from hash table POV. This will then result in a proper handover to worker now owning this reassembly. Type: fix Fixes: de34c35fc73226943538149fae9dbc5cfbdc6e75 Signed-off-by: Klement Sekera Change-Id: I9eb29c5cb1ffe3b5eb1d5a638e17ab7ba2628d28 --- src/vnet/ip/reass/ip6_sv_reass.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'src/vnet/ip/reass/ip6_sv_reass.c') diff --git a/src/vnet/ip/reass/ip6_sv_reass.c b/src/vnet/ip/reass/ip6_sv_reass.c index 58c7d8d8433..23ae6784127 100644 --- a/src/vnet/ip/reass/ip6_sv_reass.c +++ b/src/vnet/ip/reass/ip6_sv_reass.c @@ -311,6 +311,8 @@ ip6_sv_reass_find_or_create (vlib_main_t *vm, ip6_sv_reass_main_t *rm, ip6_sv_reass_t *reass = NULL; f64 now = vlib_time_now (vm); +again: + if (!clib_bihash_search_48_8 (&rm->hash, &kv->kv, &kv->kv)) { if (vm->thread_index != kv->v.thread_index) @@ -370,10 +372,14 @@ ip6_sv_reass_find_or_create (vlib_main_t *vm, ip6_sv_reass_main_t *rm, kv->v.thread_index = vm->thread_index; reass->last_heard = now; - if (clib_bihash_add_del_48_8 (&rm->hash, &kv->kv, 1)) + int rv = clib_bihash_add_del_48_8 (&rm->hash, &kv->kv, 2); + if (rv) { ip6_sv_reass_free (vm, rm, rt, reass); reass = NULL; + // if other worker created a context already work with the other copy + if (-2 == rv) + goto again; } return reass; -- cgit 1.2.3-korg