[PATCH v3] net: netfilter: Fix rpfilter dropping vrf packets by mistake

[linmiaohe]

From: Miaohe Lin <linmia...@huawei.com>

When firewalld is enabled with ipv4/ipv6 rpfilter, vrf
ipv4/ipv6 packets will be dropped because in device is
vrf but out device is an enslaved device. So failed with
the check of the rpfilter.

Signed-off-by: Miaohe Lin <linmia...@huawei.com>
---
 net/ipv4/netfilter/ipt_rpfilter.c  |  1 +
 net/ipv6/netfilter/ip6t_rpfilter.c | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/netfilter/ipt_rpfilter.c 
b/net/ipv4/netfilter/ipt_rpfilter.c
index 0b10d8812828..6e07cd0ecbec 100644
--- a/net/ipv4/netfilter/ipt_rpfilter.c
+++ b/net/ipv4/netfilter/ipt_rpfilter.c
@@ -81,6 +81,7 @@ static bool rpfilter_mt(const struct sk_buff *skb, struct 
xt_action_param *par)
        flow.flowi4_mark = info->flags & XT_RPFILTER_VALID_MARK ? skb->mark : 0;
        flow.flowi4_tos = RT_TOS(iph->tos);
        flow.flowi4_scope = RT_SCOPE_UNIVERSE;
+       flow.flowi4_oif = l3mdev_master_ifindex_rcu(xt_in(par));

        return rpfilter_lookup_reverse(xt_net(par), &flow, xt_in(par), 
info->flags) ^ invert;
 }
diff --git a/net/ipv6/netfilter/ip6t_rpfilter.c 
b/net/ipv6/netfilter/ip6t_rpfilter.c
index c3c6b09acdc4..a28c81322148 100644
--- a/net/ipv6/netfilter/ip6t_rpfilter.c
+++ b/net/ipv6/netfilter/ip6t_rpfilter.c
@@ -58,7 +58,9 @@ static bool rpfilter_lookup_reverse6(struct net *net, const 
struct sk_buff *skb,
        if (rpfilter_addr_linklocal(&iph->saddr)) {
                lookup_flags |= RT6_LOOKUP_F_IFACE;
                fl6.flowi6_oif = dev->ifindex;
-       } else if ((flags & XT_RPFILTER_LOOSE) == 0)
+       } else if (((flags & XT_RPFILTER_LOOSE) == 0) ||
+                  (netif_is_l3_master(dev)) ||
+                  (netif_is_l3_slave(dev)))
                fl6.flowi6_oif = dev->ifindex;

        rt = (void *)ip6_route_lookup(net, &fl6, skb, lookup_flags);
@@ -73,6 +75,12 @@ static bool rpfilter_lookup_reverse6(struct net *net, const 
struct sk_buff *skb,
                goto out;
        }

+       if (netif_is_l3_master(dev)) {
+               dev = dev_get_by_index_rcu(dev_net(dev), IP6CB(skb)->iif);
+               if (!dev)
+                       goto out;
+       }
+
        if (rt->rt6i_idev->dev == dev || (flags & XT_RPFILTER_LOOSE))
                ret = true;
  out:
-- 
2.19.1