target/linux/generic/backport-4.14/372-netfilter-nft_flow_offload-fix-interaction-with-vrf-.patch

   1 From: wenxu <wenxu@ucloud.cn>
   2 Date: Thu, 10 Jan 2019 14:51:35 +0800
   3 Subject: [PATCH] netfilter: nft_flow_offload: fix interaction with vrf slave
   4  device
   5
   6 In the forward chain, the iif is changed from slave device to master vrf
   7 device. Thus, flow offload does not find a match on the lower slave
   8 device.
   9
  10 This patch uses the cached route, ie. dst->dev, to update the iif and
  11 oif fields in the flow entry.
  12
  13 After this patch, the following example works fine:
  14
  15  # ip addr add dev eth0 1.1.1.1/24
  16  # ip addr add dev eth1 10.0.0.1/24
  17  # ip link add user1 type vrf table 1
  18  # ip l set user1 up
  19  # ip l set dev eth0 master user1
  20  # ip l set dev eth1 master user1
  21
  22  # nft add table firewall
  23  # nft add flowtable f fb1 { hook ingress priority 0 \; devices = { eth0, eth1 } \; }
  24  # nft add chain f ftb-all {type filter hook forward priority 0 \; policy accept \; }
  25  # nft add rule f ftb-all ct zone 1 ip protocol tcp flow offload @fb1
  26  # nft add rule f ftb-all ct zone 1 ip protocol udp flow offload @fb1
  27
  28 Signed-off-by: wenxu <wenxu@ucloud.cn>
  29 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  30 ---
  31
  32 --- a/include/net/netfilter/nf_flow_table.h
  33 +++ b/include/net/netfilter/nf_flow_table.h
  34 @@ -84,7 +84,6 @@ struct flow_offload {
  35  struct nf_flow_route {
  36         struct {
  37                 struct dst_entry        *dst;
  38 -               int                     ifindex;
  39         } tuple[FLOW_OFFLOAD_DIR_MAX];
  40  };
  41
  42 --- a/net/netfilter/nf_flow_table_core.c
  43 +++ b/net/netfilter/nf_flow_table_core.c
  44 @@ -28,6 +28,7 @@ flow_offload_fill_dir(struct flow_offloa
  45  {
  46         struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
  47         struct nf_conntrack_tuple *ctt = &ct->tuplehash[dir].tuple;
  48 +       struct dst_entry *other_dst = route->tuple[!dir].dst;
  49         struct dst_entry *dst = route->tuple[dir].dst;
  50
  51         ft->dir = dir;
  52 @@ -50,8 +51,8 @@ flow_offload_fill_dir(struct flow_offloa
  53         ft->src_port = ctt->src.u.tcp.port;
  54         ft->dst_port = ctt->dst.u.tcp.port;
  55
  56 -       ft->iifidx = route->tuple[dir].ifindex;
  57 -       ft->oifidx = route->tuple[!dir].ifindex;
  58 +       ft->iifidx = other_dst->dev->ifindex;
  59 +       ft->oifidx = dst->dev->ifindex;
  60         ft->dst_cache = dst;
  61  }
  62
  63 --- a/net/netfilter/nft_flow_offload.c
  64 +++ b/net/netfilter/nft_flow_offload.c
  65 @@ -30,9 +30,11 @@ static int nft_flow_route(const struct n
  66         switch (nft_pf(pkt)) {
  67         case NFPROTO_IPV4:
  68                 fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
  69 +               fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
  70                 break;
  71         case NFPROTO_IPV6:
  72                 fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
  73 +               fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
  74                 break;
  75         }
  76
  77 @@ -41,9 +43,7 @@ static int nft_flow_route(const struct n
  78                 return -ENOENT;
  79
  80         route->tuple[dir].dst           = this_dst;
  81 -       route->tuple[dir].ifindex       = nft_in(pkt)->ifindex;
  82         route->tuple[!dir].dst          = other_dst;
  83 -       route->tuple[!dir].ifindex      = nft_out(pkt)->ifindex;
  84
  85         return 0;
  86  }