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         u64             bytes;
  22         u64             packets;
  23 };
  24
  25 struct nft_counter_percpu {
  26         struct nft_counter      counter;
  27         struct u64_stats_sync   syncp;
  28 };
  29
  30 struct nft_counter_percpu_priv {
  31         struct nft_counter_percpu __percpu *counter;
  32 };
  33
  34 static void nft_counter_eval(const struct nft_expr *expr,
  35                              struct nft_regs *regs,
  36                              const struct nft_pktinfo *pkt)
  37 {
  38         struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
  39         struct nft_counter_percpu *this_cpu;
  40
  41         local_bh_disable();
  42         this_cpu = this_cpu_ptr(priv->counter);
  43         u64_stats_update_begin(&this_cpu->syncp);
  44         this_cpu->counter.bytes += pkt->skb->len;
  45         this_cpu->counter.packets++;
  46         u64_stats_update_end(&this_cpu->syncp);
  47         local_bh_enable();
  48 }
  49
  50 static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
  51 {
  52         struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
  53         struct nft_counter_percpu *cpu_stats;
  54         struct nft_counter total;
  55         u64 bytes, packets;
  56         unsigned int seq;
  57         int cpu;
  58
  59         memset(&total, 0, sizeof(total));
  60         for_each_possible_cpu(cpu) {
  61                 cpu_stats = per_cpu_ptr(priv->counter, cpu);
  62                 do {
  63                         seq     = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
  64                         bytes   = cpu_stats->counter.bytes;
  65                         packets = cpu_stats->counter.packets;
  66                 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq));
  67
  68                 total.packets += packets;
  69                 total.bytes += bytes;
  70         }
  71
  72         if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes)) ||
  73             nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets)))
  74                 goto nla_put_failure;
  75         return 0;
  76
  77 nla_put_failure:
  78         return -1;
  79 }
  80
  81 static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
  82         [NFTA_COUNTER_PACKETS]  = { .type = NLA_U64 },
  83         [NFTA_COUNTER_BYTES]    = { .type = NLA_U64 },
  84 };
  85
  86 static int nft_counter_init(const struct nft_ctx *ctx,
  87                             const struct nft_expr *expr,
  88                             const struct nlattr * const tb[])
  89 {
  90         struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
  91         struct nft_counter_percpu __percpu *cpu_stats;
  92         struct nft_counter_percpu *this_cpu;
  93
  94         cpu_stats = netdev_alloc_pcpu_stats(struct nft_counter_percpu);
  95         if (cpu_stats == NULL)
  96                 return ENOMEM;
  97
  98         preempt_disable();
  99         this_cpu = this_cpu_ptr(cpu_stats);
 100         if (tb[NFTA_COUNTER_PACKETS]) {
 101                 this_cpu->counter.packets =
 102                         be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
 103         }
 104         if (tb[NFTA_COUNTER_BYTES]) {
 105                 this_cpu->counter.bytes =
 106                         be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
 107         }
 108         preempt_enable();
 109         priv->counter = cpu_stats;
 110         return 0;
 111 }
 112
 113 static void nft_counter_destroy(const struct nft_ctx *ctx,
 114                                 const struct nft_expr *expr)
 115 {
 116         struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
 117
 118         free_percpu(priv->counter);
 119 }
 120
 121 static struct nft_expr_type nft_counter_type;
 122 static const struct nft_expr_ops nft_counter_ops = {
 123         .type           = &nft_counter_type,
 124         .size           = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
 125         .eval           = nft_counter_eval,
 126         .init           = nft_counter_init,
 127         .destroy        = nft_counter_destroy,
 128         .dump           = nft_counter_dump,
 129 };
 130
 131 static struct nft_expr_type nft_counter_type __read_mostly = {
 132         .name           = "counter",
 133         .ops            = &nft_counter_ops,
 134         .policy         = nft_counter_policy,
 135         .maxattr        = NFTA_COUNTER_MAX,
 136         .flags          = NFT_EXPR_STATEFUL,
 137         .owner          = THIS_MODULE,
 138 };
 139
 140 static int __init nft_counter_module_init(void)
 141 {
 142         return nft_register_expr(&nft_counter_type);
 143 }
 144
 145 static void __exit nft_counter_module_exit(void)
 146 {
 147         nft_unregister_expr(&nft_counter_type);
 148 }
 149
 150 module_init(nft_counter_module_init);
 151 module_exit(nft_counter_module_exit);
 152
 153 MODULE_LICENSE("GPL");
 154 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 155 MODULE_ALIAS_NFT_EXPR("counter");