target/linux/generic/backport-4.14/351-v4.18-netfilter-nf_flow_table-cache-mtu-in-struct-flow_off.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Fri, 16 Feb 2018 10:57:23 +0100
   3 Subject: [PATCH] netfilter: nf_flow_table: cache mtu in struct
   4  flow_offload_tuple
   5
   6 Reduces the number of cache lines touched in the offload forwarding path
   7
   8 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   9 ---
  10
  11 --- a/include/net/netfilter/nf_flow_table.h
  12 +++ b/include/net/netfilter/nf_flow_table.h
  13 @@ -55,6 +55,8 @@ struct flow_offload_tuple {
  14
  15         int                             oifidx;
  16
  17 +       u16                             mtu;
  18 +
  19         struct dst_entry                *dst_cache;
  20  };
  21
  22 --- a/net/ipv4/netfilter/nf_flow_table_ipv4.c
  23 +++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c
  24 @@ -177,7 +177,7 @@ static int nf_flow_tuple_ip(struct sk_bu
  25  }
  26
  27  /* Based on ip_exceeds_mtu(). */
  28 -static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
  29 +static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
  30  {
  31         if (skb->len <= mtu)
  32                 return false;
  33 @@ -191,17 +191,6 @@ static bool __nf_flow_exceeds_mtu(const
  34         return true;
  35  }
  36
  37 -static bool nf_flow_exceeds_mtu(struct sk_buff *skb, const struct rtable *rt)
  38 -{
  39 -       u32 mtu;
  40 -
  41 -       mtu = ip_dst_mtu_maybe_forward(&rt->dst, true);
  42 -       if (__nf_flow_exceeds_mtu(skb, mtu))
  43 -               return true;
  44 -
  45 -       return false;
  46 -}
  47 -
  48  unsigned int
  49  nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
  50                         const struct nf_hook_state *state)
  51 @@ -232,9 +221,9 @@ nf_flow_offload_ip_hook(void *priv, stru
  52
  53         dir = tuplehash->tuple.dir;
  54         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
  55 -
  56         rt = (const struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
  57 -       if (unlikely(nf_flow_exceeds_mtu(skb, rt)))
  58 +
  59 +       if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
  60                 return NF_ACCEPT;
  61
  62         if (skb_try_make_writable(skb, sizeof(*iph)))
  63 --- a/net/ipv6/netfilter/nf_flow_table_ipv6.c
  64 +++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c
  65 @@ -173,7 +173,7 @@ static int nf_flow_tuple_ipv6(struct sk_
  66  }
  67
  68  /* Based on ip_exceeds_mtu(). */
  69 -static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
  70 +static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
  71  {
  72         if (skb->len <= mtu)
  73                 return false;
  74 @@ -184,17 +184,6 @@ static bool __nf_flow_exceeds_mtu(const
  75         return true;
  76  }
  77
  78 -static bool nf_flow_exceeds_mtu(struct sk_buff *skb, const struct rt6_info *rt)
  79 -{
  80 -       u32 mtu;
  81 -
  82 -       mtu = ip6_dst_mtu_forward(&rt->dst);
  83 -       if (__nf_flow_exceeds_mtu(skb, mtu))
  84 -               return true;
  85 -
  86 -       return false;
  87 -}
  88 -
  89  unsigned int
  90  nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
  91                           const struct nf_hook_state *state)
  92 @@ -225,9 +214,9 @@ nf_flow_offload_ipv6_hook(void *priv, st
  93
  94         dir = tuplehash->tuple.dir;
  95         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
  96 -
  97         rt = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache;
  98 -       if (unlikely(nf_flow_exceeds_mtu(skb, rt)))
  99 +
 100 +       if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
 101                 return NF_ACCEPT;
 102
 103         if (skb_try_make_writable(skb, sizeof(*ip6h)))
 104 --- a/net/netfilter/nf_flow_table.c
 105 +++ b/net/netfilter/nf_flow_table.c
 106 @@ -4,6 +4,8 @@
 107  #include <linux/netfilter.h>
 108  #include <linux/rhashtable.h>
 109  #include <linux/netdevice.h>
 110 +#include <net/ip.h>
 111 +#include <net/ip6_route.h>
 112  #include <net/netfilter/nf_tables.h>
 113  #include <net/netfilter/nf_flow_table.h>
 114  #include <net/netfilter/nf_conntrack.h>
 115 @@ -23,6 +25,7 @@ flow_offload_fill_dir(struct flow_offloa
 116  {
 117         struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
 118         struct nf_conntrack_tuple *ctt = &ct->tuplehash[dir].tuple;
 119 +       struct dst_entry *dst = route->tuple[dir].dst;
 120
 121         ft->dir = dir;
 122
 123 @@ -30,10 +33,12 @@ flow_offload_fill_dir(struct flow_offloa
 124         case NFPROTO_IPV4:
 125                 ft->src_v4 = ctt->src.u3.in;
 126                 ft->dst_v4 = ctt->dst.u3.in;
 127 +               ft->mtu = ip_dst_mtu_maybe_forward(dst, true);
 128                 break;
 129         case NFPROTO_IPV6:
 130                 ft->src_v6 = ctt->src.u3.in6;
 131                 ft->dst_v6 = ctt->dst.u3.in6;
 132 +               ft->mtu = ip6_dst_mtu_forward(dst);
 133                 break;
 134         }
 135
 136 @@ -44,8 +49,7 @@ flow_offload_fill_dir(struct flow_offloa
 137
 138         ft->iifidx = route->tuple[dir].ifindex;
 139         ft->oifidx = route->tuple[!dir].ifindex;
 140 -
 141 -       ft->dst_cache = route->tuple[dir].dst;
 142 +       ft->dst_cache = dst;
 143  }
 144
 145  struct flow_offload *