[PATCH AUTOSEL 4.20 049/105] netfilter: nft_flow_offload: fix interaction with vrf slave device

Sasha Levin
2019-02-13T03:02:42Z

From: wenxu <wenxu@ucloud.cn>

[ Upstream commit 10f4e765879e514e1ce7f52ed26603047af196e2 ]

In the forward chain, the iif is changed from slave device to master vrf
device. Thus, flow offload does not find a match on the lower slave
device.

This patch uses the cached route, ie. dst->dev, to update the iif and
oif fields in the flow entry.

After this patch, the following example works fine:

# ip addr add dev eth0 1.1.1.1/24
# ip addr add dev eth1 10.0.0.1/24
# ip link add user1 type vrf table 1
# ip l set user1 up
# ip l set dev eth0 master user1
# ip l set dev eth1 master user1

# nft add table firewall
# nft add flowtable f fb1 { hook ingress priority 0 \; devices = { eth0, eth1 } \; }
# nft add chain f ftb-all {type filter hook forward priority 0 \; policy accept \; }
# nft add rule f ftb-all ct zone 1 ip protocol tcp flow offload @fb1
# nft add rule f ftb-all ct zone 1 ip protocol udp flow offload @fb1

Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/netfilter/nf_flow_table.h | 1 -
net/netfilter/nf_flow_table_core.c | 5 +++--
net/netfilter/nft_flow_offload.c | 4 ++--
3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 77e2761d4f2f..ff4eb9869e5b 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -84,7 +84,6 @@ struct flow_offload {
struct nf_flow_route {
struct {
struct dst_entry *dst;
- int ifindex;
} tuple[FLOW_OFFLOAD_DIR_MAX];
};

diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index b7a4816add76..cc91b4d6aa22 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -28,6 +28,7 @@ flow_offload_fill_dir(struct flow_offload *flow, struct nf_conn *ct,
{
struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
struct nf_conntrack_tuple *ctt = &ct->tuplehash[dir].tuple;
+ struct dst_entry *other_dst = route->tuple[!dir].dst;
struct dst_entry *dst = route->tuple[dir].dst;

ft->dir = dir;
@@ -50,8 +51,8 @@ flow_offload_fill_dir(struct flow_offload *flow, struct nf_conn *ct,
ft->src_port = ctt->src.u.tcp.port;
ft->dst_port = ctt->dst.u.tcp.port;

- ft->iifidx = route->tuple[dir].ifindex;
- ft->oifidx = route->tuple[!dir].ifindex;
+ ft->iifidx = other_dst->dev->ifindex;
+ ft->oifidx = dst->dev->ifindex;
ft->dst_cache = dst;
}

diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index ccdb8f5ababb..188c6bbf4e16 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -30,9 +30,11 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
switch (nft_pf(pkt)) {
case NFPROTO_IPV4:
fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
+ fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
break;
case NFPROTO_IPV6:
fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
+ fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
break;
}

@@ -41,9 +43,7 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
return -ENOENT;

route->tuple[dir].dst = this_dst;
- route->tuple[dir].ifindex = nft_in(pkt)->ifindex;
route->tuple[!dir].dst = other_dst;
- route->tuple[!dir].ifindex = nft_out(pkt)->ifindex;

return 0;
}
--
2.19.1