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authorRitaro Takenaka <ritarot634@gmail.com>2022-05-17 13:55:30 +0300
committerPablo Neira Ayuso <pablo@netfilter.org>2022-05-18 18:34:26 +0300
commit2738d9d963bd1f06d5114c2b4fa5771a95703991 (patch)
treea7d192ce684e8e9b070cc62fc936388647d27e41 /net
parente5eaac2beb54f0a16ff851125082d9faeb475572 (diff)
downloadlinux-2738d9d963bd1f06d5114c2b4fa5771a95703991.tar.xz
netfilter: flowtable: move dst_check to packet path
Fixes sporadic IPv6 packet loss when flow offloading is enabled. IPv6 route GC and flowtable GC are not synchronized. When dst_cache becomes stale and a packet passes through the flow before the flowtable GC teardowns it, the packet can be dropped. So, it is necessary to check dst every time in packet path. Fixes: 227e1e4d0d6c ("netfilter: nf_flowtable: skip device lookup from interface index") Signed-off-by: Ritaro Takenaka <ritarot634@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_flow_table_core.c23
-rw-r--r--net/netfilter/nf_flow_table_ip.c19
2 files changed, 20 insertions, 22 deletions
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index ebdf5332e838..f2def06d1070 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -421,32 +421,11 @@ nf_flow_table_iterate(struct nf_flowtable *flow_table,
return err;
}
-static bool flow_offload_stale_dst(struct flow_offload_tuple *tuple)
-{
- struct dst_entry *dst;
-
- if (tuple->xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
- tuple->xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
- dst = tuple->dst_cache;
- if (!dst_check(dst, tuple->dst_cookie))
- return true;
- }
-
- return false;
-}
-
-static bool nf_flow_has_stale_dst(struct flow_offload *flow)
-{
- return flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple) ||
- flow_offload_stale_dst(&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple);
-}
-
static void nf_flow_offload_gc_step(struct nf_flowtable *flow_table,
struct flow_offload *flow, void *data)
{
if (nf_flow_has_expired(flow) ||
- nf_ct_is_dying(flow->ct) ||
- nf_flow_has_stale_dst(flow))
+ nf_ct_is_dying(flow->ct))
flow_offload_teardown(flow);
if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 32c0eb1b4821..b350fe9d00b0 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -248,6 +248,15 @@ static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
return true;
}
+static inline bool nf_flow_dst_check(struct flow_offload_tuple *tuple)
+{
+ if (tuple->xmit_type != FLOW_OFFLOAD_XMIT_NEIGH &&
+ tuple->xmit_type != FLOW_OFFLOAD_XMIT_XFRM)
+ return true;
+
+ return dst_check(tuple->dst_cache, tuple->dst_cookie);
+}
+
static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb,
const struct nf_hook_state *state,
struct dst_entry *dst)
@@ -367,6 +376,11 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
if (nf_flow_state_check(flow, iph->protocol, skb, thoff))
return NF_ACCEPT;
+ if (!nf_flow_dst_check(&tuplehash->tuple)) {
+ flow_offload_teardown(flow);
+ return NF_ACCEPT;
+ }
+
if (skb_try_make_writable(skb, thoff + hdrsize))
return NF_DROP;
@@ -624,6 +638,11 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
if (nf_flow_state_check(flow, ip6h->nexthdr, skb, thoff))
return NF_ACCEPT;
+ if (!nf_flow_dst_check(&tuplehash->tuple)) {
+ flow_offload_teardown(flow);
+ return NF_ACCEPT;
+ }
+
if (skb_try_make_writable(skb, thoff + hdrsize))
return NF_DROP;