Move dst_check() to the garbage collector path. Stale routes trigger the
flow entry teardown state which makes affected flows go back to the
classic forwarding path to re-evaluate flow offloading.
IPv6 requires the dst cookie to work, store it in the flow_tuple,
otherwise dst_check() always fails.
Fixes: e5075c0badaa ("netfilter: flowtable: call dst_check() to fall back to classic forwarding")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_flow_table.h | 5 +++-
net/netfilter/nf_flow_table_core.c | 37 ++++++++++++++++++++++++++-
net/netfilter/nf_flow_table_ip.c | 22 +++-------------
3 files changed, 44 insertions(+), 20 deletions(-)
diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 4d991c1e93ef..583b327d8fc0 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -129,7 +129,10 @@ struct flow_offload_tuple {
in_vlan_ingress:2;
u16 mtu;
union {
- struct dst_entry *dst_cache;
+ struct {
+ struct dst_entry *dst_cache;
+ u32 dst_cookie;
+ };
struct {
u32 ifidx;
u32 hw_ifidx;
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 1bce1d2805c4..76573bae6664 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -74,6 +74,18 @@ struct flow_offload *flow_offload_alloc(struct nf_conn *ct)
}
EXPORT_SYMBOL_GPL(flow_offload_alloc);
+static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
+{
+ const struct rt6_info *rt;
+
+ if (flow_tuple->l3proto == NFPROTO_IPV6) {
+ rt = (const struct rt6_info *)flow_tuple->dst_cache;
+ return rt6_get_cookie(rt);
+ }
+
+ return 0;
+}
+
static int flow_offload_fill_route(struct flow_offload *flow,
const struct nf_flow_route *route,
enum flow_offload_tuple_dir dir)
@@ -116,6 +128,7 @@ static int flow_offload_fill_route(struct flow_offload *flow,
return -1;
flow_tuple->dst_cache = dst;
+ flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
break;
}
flow_tuple->xmit_type = route->tuple[dir].xmit_type;
@@ -390,11 +403,33 @@ 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 flow_offload *flow, void *data)
{
struct nf_flowtable *flow_table = data;
- if (nf_flow_has_expired(flow) || nf_ct_is_dying(flow->ct))
+ if (nf_flow_has_expired(flow) ||
+ nf_ct_is_dying(flow->ct) ||
+ nf_flow_has_stale_dst(flow))
set_bit(NF_FLOW_TEARDOWN, &flow->flags);
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 12cb0cc6958c..889cf88d3dba 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -364,15 +364,6 @@ 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 (tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
- tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
- rt = (struct rtable *)tuplehash->tuple.dst_cache;
- if (!dst_check(&rt->dst, 0)) {
- flow_offload_teardown(flow);
- return NF_ACCEPT;
- }
- }
-
if (skb_try_make_writable(skb, thoff + hdrsize))
return NF_DROP;
@@ -391,6 +382,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
+ rt = (struct rtable *)tuplehash->tuple.dst_cache;
memset(skb->cb, 0, sizeof(struct inet_skb_parm));
IPCB(skb)->iif = skb->dev->ifindex;
IPCB(skb)->flags = IPSKB_FORWARDED;
@@ -399,6 +391,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
switch (tuplehash->tuple.xmit_type) {
case FLOW_OFFLOAD_XMIT_NEIGH:
+ rt = (struct rtable *)tuplehash->tuple.dst_cache;
outdev = rt->dst.dev;
skb->dev = outdev;
nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
@@ -607,15 +600,6 @@ 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 (tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
- tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM) {
- rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
- if (!dst_check(&rt->dst, 0)) {
- flow_offload_teardown(flow);
- return NF_ACCEPT;
- }
- }
-
if (skb_try_make_writable(skb, thoff + hdrsize))
return NF_DROP;
@@ -633,6 +617,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
+ rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
IP6CB(skb)->iif = skb->dev->ifindex;
IP6CB(skb)->flags = IP6SKB_FORWARDED;
@@ -641,6 +626,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
switch (tuplehash->tuple.xmit_type) {
case FLOW_OFFLOAD_XMIT_NEIGH:
+ rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
outdev = rt->dst.dev;
skb->dev = outdev;
nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
--
2.30.2
