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author | Ritaro Takenaka <ritarot634@gmail.com> | 2022-05-17 12:55:30 +0200 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-05-18 17:34:26 +0200 |
commit | 2738d9d963bd1f06d5114c2b4fa5771a95703991 (patch) | |
tree | a7d192ce684e8e9b070cc62fc936388647d27e41 /net/netfilter/nf_flow_table_ip.c | |
parent | e5eaac2beb54f0a16ff851125082d9faeb475572 (diff) | |
download | linux-2738d9d963bd1f06d5114c2b4fa5771a95703991.tar.gz linux-2738d9d963bd1f06d5114c2b4fa5771a95703991.tar.bz2 linux-2738d9d963bd1f06d5114c2b4fa5771a95703991.zip |
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/netfilter/nf_flow_table_ip.c')
-rw-r--r-- | net/netfilter/nf_flow_table_ip.c | 19 |
1 files changed, 19 insertions, 0 deletions
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; |