kernel/net/netfilter/nft_counter.c

   1 /*
   2  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Development of this code funded by Astaro AG (http://www.astaro.com/)
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/seqlock.h>
  15 #include <linux/netlink.h>
  16 #include <linux/netfilter.h>
  17 #include <linux/netfilter/nf_tables.h>
  18 #include <net/netfilter/nf_tables.h>
  19
  20 struct nft_counter {
  21         seqlock_t       lock;
  22         u64             bytes;
  23         u64             packets;
  24 };
  25
  26 static void nft_counter_eval(const struct nft_expr *expr,
  27                              struct nft_regs *regs,
  28                              const struct nft_pktinfo *pkt)
  29 {
  30         struct nft_counter *priv = nft_expr_priv(expr);
  31
  32         write_seqlock_bh(&priv->lock);
  33         priv->bytes += pkt->skb->len;
  34         priv->packets++;
  35         write_sequnlock_bh(&priv->lock);
  36 }
  37
  38 static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
  39 {
  40         struct nft_counter *priv = nft_expr_priv(expr);
  41         unsigned int seq;
  42         u64 bytes;
  43         u64 packets;
  44
  45         do {
  46                 seq = read_seqbegin(&priv->lock);
  47                 bytes   = priv->bytes;
  48                 packets = priv->packets;
  49         } while (read_seqretry(&priv->lock, seq));
  50
  51         if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(bytes)))
  52                 goto nla_put_failure;
  53         if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(packets)))
  54                 goto nla_put_failure;
  55         return 0;
  56
  57 nla_put_failure:
  58         return -1;
  59 }
  60
  61 static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
  62         [NFTA_COUNTER_PACKETS]  = { .type = NLA_U64 },
  63         [NFTA_COUNTER_BYTES]    = { .type = NLA_U64 },
  64 };
  65
  66 static int nft_counter_init(const struct nft_ctx *ctx,
  67                             const struct nft_expr *expr,
  68                             const struct nlattr * const tb[])
  69 {
  70         struct nft_counter *priv = nft_expr_priv(expr);
  71
  72         if (tb[NFTA_COUNTER_PACKETS])
  73                 priv->packets = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
  74         if (tb[NFTA_COUNTER_BYTES])
  75                 priv->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
  76
  77         seqlock_init(&priv->lock);
  78         return 0;
  79 }
  80
  81 static struct nft_expr_type nft_counter_type;
  82 static const struct nft_expr_ops nft_counter_ops = {
  83         .type           = &nft_counter_type,
  84         .size           = NFT_EXPR_SIZE(sizeof(struct nft_counter)),
  85         .eval           = nft_counter_eval,
  86         .init           = nft_counter_init,
  87         .dump           = nft_counter_dump,
  88 };
  89
  90 static struct nft_expr_type nft_counter_type __read_mostly = {
  91         .name           = "counter",
  92         .ops            = &nft_counter_ops,
  93         .policy         = nft_counter_policy,
  94         .maxattr        = NFTA_COUNTER_MAX,
  95         .flags          = NFT_EXPR_STATEFUL,
  96         .owner          = THIS_MODULE,
  97 };
  98
  99 static int __init nft_counter_module_init(void)
 100 {
 101         return nft_register_expr(&nft_counter_type);
 102 }
 103
 104 static void __exit nft_counter_module_exit(void)
 105 {
 106         nft_unregister_expr(&nft_counter_type);
 107 }
 108
 109 module_init(nft_counter_module_init);
 110 module_exit(nft_counter_module_exit);
 111
 112 MODULE_LICENSE("GPL");
 113 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 114 MODULE_ALIAS_NFT_EXPR("counter");