target/linux/generic/backport-4.14/291-v4.16-netfilter-core-remove-synchronize_net-call-if-nfqueu.patch

   1 From 26888dfd7e7454686b8d3ea9ba5045d5f236e4d7 Mon Sep 17 00:00:00 2001
   2 From: Florian Westphal <fw@strlen.de>
   3 Date: Fri, 1 Dec 2017 00:21:03 +0100
   4 Subject: [PATCH 03/11] netfilter: core: remove synchronize_net call if nfqueue
   5  is used
   6
   7 since commit 960632ece6949b ("netfilter: convert hook list to an array")
   8 nfqueue no longer stores a pointer to the hook that caused the packet
   9 to be queued.  Therefore no extra synchronize_net() call is needed after
  10 dropping the packets enqueued by the old rule blob.
  11
  12 Signed-off-by: Florian Westphal <fw@strlen.de>
  13 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  14 ---
  15  include/net/netfilter/nf_queue.h | 2 +-
  16  net/netfilter/core.c             | 6 +-----
  17  net/netfilter/nf_internals.h     | 2 +-
  18  net/netfilter/nf_queue.c         | 7 ++-----
  19  net/netfilter/nfnetlink_queue.c  | 9 ++-------
  20  5 files changed, 7 insertions(+), 19 deletions(-)
  21
  22 --- a/include/net/netfilter/nf_queue.h
  23 +++ b/include/net/netfilter/nf_queue.h
  24 @@ -25,7 +25,7 @@ struct nf_queue_entry {
  25  struct nf_queue_handler {
  26         int             (*outfn)(struct nf_queue_entry *entry,
  27                                  unsigned int queuenum);
  28 -       unsigned int    (*nf_hook_drop)(struct net *net);
  29 +       void            (*nf_hook_drop)(struct net *net);
  30  };
  31
  32  void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
  33 --- a/net/netfilter/core.c
  34 +++ b/net/netfilter/core.c
  35 @@ -342,7 +342,6 @@ void nf_unregister_net_hook(struct net *
  36  {
  37         struct nf_hook_entries __rcu **pp;
  38         struct nf_hook_entries *p;
  39 -       unsigned int nfq;
  40
  41         pp = nf_hook_entry_head(net, reg);
  42         if (!pp)
  43 @@ -365,10 +364,7 @@ void nf_unregister_net_hook(struct net *
  44
  45         synchronize_net();
  46
  47 -       /* other cpu might still process nfqueue verdict that used reg */
  48 -       nfq = nf_queue_nf_hook_drop(net);
  49 -       if (nfq)
  50 -               synchronize_net();
  51 +       nf_queue_nf_hook_drop(net);
  52         kvfree(p);
  53  }
  54  EXPORT_SYMBOL(nf_unregister_net_hook);
  55 --- a/net/netfilter/nf_internals.h
  56 +++ b/net/netfilter/nf_internals.h
  57 @@ -10,7 +10,7 @@
  58  int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
  59              const struct nf_hook_entries *entries, unsigned int index,
  60              unsigned int verdict);
  61 -unsigned int nf_queue_nf_hook_drop(struct net *net);
  62 +void nf_queue_nf_hook_drop(struct net *net);
  63
  64  /* nf_log.c */
  65  int __init netfilter_log_init(void);
  66 --- a/net/netfilter/nf_queue.c
  67 +++ b/net/netfilter/nf_queue.c
  68 @@ -109,18 +109,15 @@ bool nf_queue_entry_get_refs(struct nf_q
  69  }
  70  EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs);
  71
  72 -unsigned int nf_queue_nf_hook_drop(struct net *net)
  73 +void nf_queue_nf_hook_drop(struct net *net)
  74  {
  75         const struct nf_queue_handler *qh;
  76 -       unsigned int count = 0;
  77
  78         rcu_read_lock();
  79         qh = rcu_dereference(net->nf.queue_handler);
  80         if (qh)
  81 -               count = qh->nf_hook_drop(net);
  82 +               qh->nf_hook_drop(net);
  83         rcu_read_unlock();
  84 -
  85 -       return count;
  86  }
  87  EXPORT_SYMBOL_GPL(nf_queue_nf_hook_drop);
  88
  89 --- a/net/netfilter/nfnetlink_queue.c
  90 +++ b/net/netfilter/nfnetlink_queue.c
  91 @@ -953,23 +953,18 @@ static struct notifier_block nfqnl_dev_n
  92         .notifier_call  = nfqnl_rcv_dev_event,
  93  };
  94
  95 -static unsigned int nfqnl_nf_hook_drop(struct net *net)
  96 +static void nfqnl_nf_hook_drop(struct net *net)
  97  {
  98         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
  99 -       unsigned int instances = 0;
 100         int i;
 101
 102         for (i = 0; i < INSTANCE_BUCKETS; i++) {
 103                 struct nfqnl_instance *inst;
 104                 struct hlist_head *head = &q->instance_table[i];
 105
 106 -               hlist_for_each_entry_rcu(inst, head, hlist) {
 107 +               hlist_for_each_entry_rcu(inst, head, hlist)
 108                         nfqnl_flush(inst, NULL, 0);
 109 -                       instances++;
 110 -               }
 111         }
 112 -
 113 -       return instances;
 114  }
 115
 116  static int