nf_conntrack_acct.c

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/* Accouting handling for netfilter. */

/*
 * (C) 2008 Krzysztof Piotr Oledzki <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/netfilter.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/export.h>

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_acct.h>

static bool nf_ct_acct __read_mostly;

module_param_named(acct, nf_ct_acct, bool, 0644);
MODULE_PARM_DESC(acct, "Enable connection tracking flow accounting.");

#ifdef CONFIG_SYSCTL
static struct ctl_table acct_sysctl_table[] = {
    {
        .procname   = "nf_conntrack_acct",
        .data       = &init_net.ct.sysctl_acct,
        .maxlen     = sizeof(unsigned int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec,
    },
    {}
};
#endif /* CONFIG_SYSCTL */

unsigned int
seq_print_acct(struct seq_file *s, const struct nf_conn *ct, int dir)
{
    struct nf_conn_counter *acct;

    acct = nf_conn_acct_find(ct);
    if (!acct)
        return 0;

    return seq_printf(s, "packets=%llu bytes=%llu ",
              (unsigned long long)atomic64_read(&acct[dir].packets),
              (unsigned long long)atomic64_read(&acct[dir].bytes));
};
EXPORT_SYMBOL_GPL(seq_print_acct);

static struct nf_ct_ext_type acct_extend __read_mostly = {
    .len    = sizeof(struct nf_conn_counter[IP_CT_DIR_MAX]),
    .align  = __alignof__(struct nf_conn_counter[IP_CT_DIR_MAX]),
    .id = NF_CT_EXT_ACCT,
};

#ifdef CONFIG_SYSCTL
static int nf_conntrack_acct_init_sysctl(struct net *net)
{
    struct ctl_table *table;

    table = kmemdup(acct_sysctl_table, sizeof(acct_sysctl_table),
            GFP_KERNEL);
    if (!table)
        goto out;

    table[0].data = &net->ct.sysctl_acct;

    net->ct.acct_sysctl_header = register_net_sysctl(net, "net/netfilter",
                             table);
    if (!net->ct.acct_sysctl_header) {
        printk(KERN_ERR "nf_conntrack_acct: can't register to sysctl.\n");
        goto out_register;
    }
    return 0;

out_register:
    kfree(table);
out:
    return -ENOMEM;
}

static void nf_conntrack_acct_fini_sysctl(struct net *net)
{
    struct ctl_table *table;

    table = net->ct.acct_sysctl_header->ctl_table_arg;
    unregister_net_sysctl_table(net->ct.acct_sysctl_header);
    kfree(table);
}
#else
static int nf_conntrack_acct_init_sysctl(struct net *net)
{
    return 0;
}

static void nf_conntrack_acct_fini_sysctl(struct net *net)
{
}
#endif

int nf_conntrack_acct_init(struct net *net)
{
    int ret;

    net->ct.sysctl_acct = nf_ct_acct;

    if (net_eq(net, &init_net)) {
        ret = nf_ct_extend_register(&acct_extend);
        if (ret < 0) {
            printk(KERN_ERR "nf_conntrack_acct: Unable to register extension\n");
            goto out_extend_register;
        }
    }

    ret = nf_conntrack_acct_init_sysctl(net);
    if (ret < 0)
        goto out_sysctl;

    return 0;

out_sysctl:
    if (net_eq(net, &init_net))
        nf_ct_extend_unregister(&acct_extend);
out_extend_register:
    return ret;
}

void nf_conntrack_acct_fini(struct net *net)
{
    nf_conntrack_acct_fini_sysctl(net);
    if (net_eq(net, &init_net))
        nf_ct_extend_unregister(&acct_extend);
}