target/linux/generic/backport-4.14/294-v4.16-netfilter-reduce-hook-array-sizes-to-what-is-needed.patch

   1 From ef57170bbfdd6958281011332b1fd237712f69f0 Mon Sep 17 00:00:00 2001
   2 From: Florian Westphal <fw@strlen.de>
   3 Date: Thu, 7 Dec 2017 16:28:24 +0100
   4 Subject: [PATCH 06/11] netfilter: reduce hook array sizes to what is needed
   5
   6 Not all families share the same hook count, adjust sizes to what is
   7 needed.
   8
   9 struct net before:
  10 /* size: 6592, cachelines: 103, members: 46 */
  11 after:
  12 /* size: 5952, cachelines: 93, members: 46 */
  13
  14 Signed-off-by: Florian Westphal <fw@strlen.de>
  15 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  16 ---
  17  include/net/netns/netfilter.h | 10 +++++-----
  18  net/netfilter/core.c          | 24 +++++++++++++++++-------
  19  2 files changed, 22 insertions(+), 12 deletions(-)
  20
  21 --- a/include/net/netns/netfilter.h
  22 +++ b/include/net/netns/netfilter.h
  23 @@ -17,11 +17,11 @@ struct netns_nf {
  24  #ifdef CONFIG_SYSCTL
  25         struct ctl_table_header *nf_log_dir_header;
  26  #endif
  27 -       struct nf_hook_entries __rcu *hooks_ipv4[NF_MAX_HOOKS];
  28 -       struct nf_hook_entries __rcu *hooks_ipv6[NF_MAX_HOOKS];
  29 -       struct nf_hook_entries __rcu *hooks_arp[NF_MAX_HOOKS];
  30 -       struct nf_hook_entries __rcu *hooks_bridge[NF_MAX_HOOKS];
  31 -       struct nf_hook_entries __rcu *hooks_decnet[NF_MAX_HOOKS];
  32 +       struct nf_hook_entries __rcu *hooks_ipv4[NF_INET_NUMHOOKS];
  33 +       struct nf_hook_entries __rcu *hooks_ipv6[NF_INET_NUMHOOKS];
  34 +       struct nf_hook_entries __rcu *hooks_arp[NF_ARP_NUMHOOKS];
  35 +       struct nf_hook_entries __rcu *hooks_bridge[NF_INET_NUMHOOKS];
  36 +       struct nf_hook_entries __rcu *hooks_decnet[NF_DN_NUMHOOKS];
  37  #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
  38         bool                    defrag_ipv4;
  39  #endif
  40 --- a/net/netfilter/core.c
  41 +++ b/net/netfilter/core.c
  42 @@ -268,14 +268,24 @@ static struct nf_hook_entries __rcu **nf
  43         case NFPROTO_NETDEV:
  44                 break;
  45         case NFPROTO_ARP:
  46 +               if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_arp) <= reg->hooknum))
  47 +                       return NULL;
  48                 return net->nf.hooks_arp + reg->hooknum;
  49         case NFPROTO_BRIDGE:
  50 +               if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_bridge) <= reg->hooknum))
  51 +                       return NULL;
  52                 return net->nf.hooks_bridge + reg->hooknum;
  53         case NFPROTO_IPV4:
  54 +               if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv4) <= reg->hooknum))
  55 +                       return NULL;
  56                 return net->nf.hooks_ipv4 + reg->hooknum;
  57         case NFPROTO_IPV6:
  58 +               if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv6) <= reg->hooknum))
  59 +                       return NULL;
  60                 return net->nf.hooks_ipv6 + reg->hooknum;
  61         case NFPROTO_DECNET:
  62 +               if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_decnet) <= reg->hooknum))
  63 +                       return NULL;
  64                 return net->nf.hooks_decnet + reg->hooknum;
  65         default:
  66                 WARN_ON_ONCE(1);
  67 @@ -549,21 +559,21 @@ void (*nf_nat_decode_session_hook)(struc
  68  EXPORT_SYMBOL(nf_nat_decode_session_hook);
  69  #endif
  70
  71 -static void __net_init __netfilter_net_init(struct nf_hook_entries *e[NF_MAX_HOOKS])
  72 +static void __net_init __netfilter_net_init(struct nf_hook_entries **e, int max)
  73  {
  74         int h;
  75
  76 -       for (h = 0; h < NF_MAX_HOOKS; h++)
  77 +       for (h = 0; h < max; h++)
  78                 RCU_INIT_POINTER(e[h], NULL);
  79  }
  80
  81  static int __net_init netfilter_net_init(struct net *net)
  82  {
  83 -       __netfilter_net_init(net->nf.hooks_ipv4);
  84 -       __netfilter_net_init(net->nf.hooks_ipv6);
  85 -       __netfilter_net_init(net->nf.hooks_arp);
  86 -       __netfilter_net_init(net->nf.hooks_bridge);
  87 -       __netfilter_net_init(net->nf.hooks_decnet);
  88 +       __netfilter_net_init(net->nf.hooks_ipv4, ARRAY_SIZE(net->nf.hooks_ipv4));
  89 +       __netfilter_net_init(net->nf.hooks_ipv6, ARRAY_SIZE(net->nf.hooks_ipv6));
  90 +       __netfilter_net_init(net->nf.hooks_arp, ARRAY_SIZE(net->nf.hooks_arp));
  91 +       __netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge));
  92 +       __netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet));
  93
  94  #ifdef CONFIG_PROC_FS
  95         net->nf.proc_netfilter = proc_net_mkdir(net, "netfilter",