nf_conntrack_standalone.c

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/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <[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/types.h>
#include <linux/netfilter.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/percpu.h>
#include <linux/netdevice.h>
#include <linux/security.h>
#include <net/net_namespace.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_conntrack_timestamp.h>
#include <linux/rculist_nulls.h>

MODULE_LICENSE("GPL");

#ifdef CONFIG_NF_CONNTRACK_PROCFS
int
print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
            const struct nf_conntrack_l3proto *l3proto,
            const struct nf_conntrack_l4proto *l4proto)
{
    return l3proto->print_tuple(s, tuple) || l4proto->print_tuple(s, tuple);
}
EXPORT_SYMBOL_GPL(print_tuple);

struct ct_iter_state {
    struct seq_net_private p;
    unsigned int bucket;
    u_int64_t time_now;
};

static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
{
    struct net *net = seq_file_net(seq);
    struct ct_iter_state *st = seq->private;
    struct hlist_nulls_node *n;

    for (st->bucket = 0;
         st->bucket < net->ct.htable_size;
         st->bucket++) {
        n = rcu_dereference(hlist_nulls_first_rcu(&net->ct.hash[st->bucket]));
        if (!is_a_nulls(n))
            return n;
    }
    return NULL;
}

static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
                      struct hlist_nulls_node *head)
{
    struct net *net = seq_file_net(seq);
    struct ct_iter_state *st = seq->private;

    head = rcu_dereference(hlist_nulls_next_rcu(head));
    while (is_a_nulls(head)) {
        if (likely(get_nulls_value(head) == st->bucket)) {
            if (++st->bucket >= net->ct.htable_size)
                return NULL;
        }
        head = rcu_dereference(
                hlist_nulls_first_rcu(
                    &net->ct.hash[st->bucket]));
    }
    return head;
}

static struct hlist_nulls_node *ct_get_idx(struct seq_file *seq, loff_t pos)
{
    struct hlist_nulls_node *head = ct_get_first(seq);

    if (head)
        while (pos && (head = ct_get_next(seq, head)))
            pos--;
    return pos ? NULL : head;
}

static void *ct_seq_start(struct seq_file *seq, loff_t *pos)
    __acquires(RCU)
{
    struct ct_iter_state *st = seq->private;

    st->time_now = ktime_to_ns(ktime_get_real());
    rcu_read_lock();
    return ct_get_idx(seq, *pos);
}

static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
    (*pos)++;
    return ct_get_next(s, v);
}

static void ct_seq_stop(struct seq_file *s, void *v)
    __releases(RCU)
{
    rcu_read_unlock();
}

#ifdef CONFIG_NF_CONNTRACK_SECMARK
static int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
{
    int ret;
    u32 len;
    char *secctx;

    ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
    if (ret)
        return 0;

    ret = seq_printf(s, "secctx=%s ", secctx);

    security_release_secctx(secctx, len);
    return ret;
}
#else
static inline int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
{
    return 0;
}
#endif

#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
static int ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
{
    struct ct_iter_state *st = s->private;
    struct nf_conn_tstamp *tstamp;
    s64 delta_time;

    tstamp = nf_conn_tstamp_find(ct);
    if (tstamp) {
        delta_time = st->time_now - tstamp->start;
        if (delta_time > 0)
            delta_time = div_s64(delta_time, NSEC_PER_SEC);
        else
            delta_time = 0;

        return seq_printf(s, "delta-time=%llu ",
                  (unsigned long long)delta_time);
    }
    return 0;
}
#else
static inline int
ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
{
    return 0;
}
#endif

/* return 0 on success, 1 in case of error */
static int ct_seq_show(struct seq_file *s, void *v)
{
    struct nf_conntrack_tuple_hash *hash = v;
    struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
    const struct nf_conntrack_l3proto *l3proto;
    const struct nf_conntrack_l4proto *l4proto;
    int ret = 0;

    NF_CT_ASSERT(ct);
    if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
        return 0;

    /* we only want to print DIR_ORIGINAL */
    if (NF_CT_DIRECTION(hash))
        goto release;

    l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
    NF_CT_ASSERT(l3proto);
    l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
    NF_CT_ASSERT(l4proto);

    ret = -ENOSPC;
    if (seq_printf(s, "%-8s %u %-8s %u %ld ",
               l3proto->name, nf_ct_l3num(ct),
               l4proto->name, nf_ct_protonum(ct),
               timer_pending(&ct->timeout)
               ? (long)(ct->timeout.expires - jiffies)/HZ : 0) != 0)
        goto release;

    if (l4proto->print_conntrack && l4proto->print_conntrack(s, ct))
        goto release;

    if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
            l3proto, l4proto))
        goto release;

    if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
        goto release;

    if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
        if (seq_printf(s, "[UNREPLIED] "))
            goto release;

    if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
            l3proto, l4proto))
        goto release;

    if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
        goto release;

    if (test_bit(IPS_ASSURED_BIT, &ct->status))
        if (seq_printf(s, "[ASSURED] "))
            goto release;

#if defined(CONFIG_NF_CONNTRACK_MARK)
    if (seq_printf(s, "mark=%u ", ct->mark))
        goto release;
#endif

    if (ct_show_secctx(s, ct))
        goto release;

#ifdef CONFIG_NF_CONNTRACK_ZONES
    if (seq_printf(s, "zone=%u ", nf_ct_zone(ct)))
        goto release;
#endif

    if (ct_show_delta_time(s, ct))
        goto release;

    if (seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use)))
        goto release;

    ret = 0;
release:
    nf_ct_put(ct);
    return ret;
}

static const struct seq_operations ct_seq_ops = {
    .start = ct_seq_start,
    .next  = ct_seq_next,
    .stop  = ct_seq_stop,
    .show  = ct_seq_show
};

static int ct_open(struct inode *inode, struct file *file)
{
    return seq_open_net(inode, file, &ct_seq_ops,
            sizeof(struct ct_iter_state));
}

static const struct file_operations ct_file_ops = {
    .owner   = THIS_MODULE,
    .open    = ct_open,
    .read    = seq_read,
    .llseek  = seq_lseek,
    .release = seq_release_net,
};

static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
{
    struct net *net = seq_file_net(seq);
    int cpu;

    if (*pos == 0)
        return SEQ_START_TOKEN;

    for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
        if (!cpu_possible(cpu))
            continue;
        *pos = cpu + 1;
        return per_cpu_ptr(net->ct.stat, cpu);
    }

    return NULL;
}

static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
    struct net *net = seq_file_net(seq);
    int cpu;

    for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
        if (!cpu_possible(cpu))
            continue;
        *pos = cpu + 1;
        return per_cpu_ptr(net->ct.stat, cpu);
    }

    return NULL;
}

static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
{
}

static int ct_cpu_seq_show(struct seq_file *seq, void *v)
{
    struct net *net = seq_file_net(seq);
    unsigned int nr_conntracks = atomic_read(&net->ct.count);
    const struct ip_conntrack_stat *st = v;

    if (v == SEQ_START_TOKEN) {
        seq_printf(seq, "entries  searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error  expect_new expect_create expect_delete search_restart\n");
        return 0;
    }

    seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
            "%08x %08x %08x %08x %08x  %08x %08x %08x %08x\n",
           nr_conntracks,
           st->searched,
           st->found,
           st->new,
           st->invalid,
           st->ignore,
           st->delete,
           st->delete_list,
           st->insert,
           st->insert_failed,
           st->drop,
           st->early_drop,
           st->error,

           st->expect_new,
           st->expect_create,
           st->expect_delete,
           st->search_restart
        );
    return 0;
}

static const struct seq_operations ct_cpu_seq_ops = {
    .start  = ct_cpu_seq_start,
    .next   = ct_cpu_seq_next,
    .stop   = ct_cpu_seq_stop,
    .show   = ct_cpu_seq_show,
};

static int ct_cpu_seq_open(struct inode *inode, struct file *file)
{
    return seq_open_net(inode, file, &ct_cpu_seq_ops,
                sizeof(struct seq_net_private));
}

static const struct file_operations ct_cpu_seq_fops = {
    .owner   = THIS_MODULE,
    .open    = ct_cpu_seq_open,
    .read    = seq_read,
    .llseek  = seq_lseek,
    .release = seq_release_net,
};

static int nf_conntrack_standalone_init_proc(struct net *net)
{
    struct proc_dir_entry *pde;

    pde = proc_net_fops_create(net, "nf_conntrack", 0440, &ct_file_ops);
    if (!pde)
        goto out_nf_conntrack;

    pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,
              &ct_cpu_seq_fops);
    if (!pde)
        goto out_stat_nf_conntrack;
    return 0;

out_stat_nf_conntrack:
    proc_net_remove(net, "nf_conntrack");
out_nf_conntrack:
    return -ENOMEM;
}

static void nf_conntrack_standalone_fini_proc(struct net *net)
{
    remove_proc_entry("nf_conntrack", net->proc_net_stat);
    proc_net_remove(net, "nf_conntrack");
}
#else
static int nf_conntrack_standalone_init_proc(struct net *net)
{
    return 0;
}

static void nf_conntrack_standalone_fini_proc(struct net *net)
{
}
#endif /* CONFIG_NF_CONNTRACK_PROCFS */

/* Sysctl support */

#ifdef CONFIG_SYSCTL
/* Log invalid packets of a given protocol */
static int log_invalid_proto_min = 0;
static int log_invalid_proto_max = 255;

static struct ctl_table_header *nf_ct_netfilter_header;

static ctl_table nf_ct_sysctl_table[] = {
    {
        .procname   = "nf_conntrack_max",
        .data       = &nf_conntrack_max,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec,
    },
    {
        .procname   = "nf_conntrack_count",
        .data       = &init_net.ct.count,
        .maxlen     = sizeof(int),
        .mode       = 0444,
        .proc_handler   = proc_dointvec,
    },
    {
        .procname       = "nf_conntrack_buckets",
        .data           = &init_net.ct.htable_size,
        .maxlen         = sizeof(unsigned int),
        .mode           = 0444,
        .proc_handler   = proc_dointvec,
    },
    {
        .procname   = "nf_conntrack_checksum",
        .data       = &init_net.ct.sysctl_checksum,
        .maxlen     = sizeof(unsigned int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec,
    },
    {
        .procname   = "nf_conntrack_log_invalid",
        .data       = &init_net.ct.sysctl_log_invalid,
        .maxlen     = sizeof(unsigned int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec_minmax,
        .extra1     = &log_invalid_proto_min,
        .extra2     = &log_invalid_proto_max,
    },
    {
        .procname   = "nf_conntrack_expect_max",
        .data       = &nf_ct_expect_max,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec,
    },
    { }
};

#define NET_NF_CONNTRACK_MAX 2089

static ctl_table nf_ct_netfilter_table[] = {
    {
        .procname   = "nf_conntrack_max",
        .data       = &nf_conntrack_max,
        .maxlen     = sizeof(int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec,
    },
    { }
};

static int nf_conntrack_standalone_init_sysctl(struct net *net)
{
    struct ctl_table *table;

    if (net_eq(net, &init_net)) {
        nf_ct_netfilter_header =
               register_net_sysctl(&init_net, "net", nf_ct_netfilter_table);
        if (!nf_ct_netfilter_header)
            goto out;
    }

    table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
            GFP_KERNEL);
    if (!table)
        goto out_kmemdup;

    table[1].data = &net->ct.count;
    table[2].data = &net->ct.htable_size;
    table[3].data = &net->ct.sysctl_checksum;
    table[4].data = &net->ct.sysctl_log_invalid;

    net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
    if (!net->ct.sysctl_header)
        goto out_unregister_netfilter;

    return 0;

out_unregister_netfilter:
    kfree(table);
out_kmemdup:
    if (net_eq(net, &init_net))
        unregister_net_sysctl_table(nf_ct_netfilter_header);
out:
    printk(KERN_ERR "nf_conntrack: can't register to sysctl.\n");
    return -ENOMEM;
}

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

    if (net_eq(net, &init_net))
        unregister_net_sysctl_table(nf_ct_netfilter_header);
    table = net->ct.sysctl_header->ctl_table_arg;
    unregister_net_sysctl_table(net->ct.sysctl_header);
    kfree(table);
}
#else
static int nf_conntrack_standalone_init_sysctl(struct net *net)
{
    return 0;
}

static void nf_conntrack_standalone_fini_sysctl(struct net *net)
{
}
#endif /* CONFIG_SYSCTL */

static int nf_conntrack_net_init(struct net *net)
{
    int ret;

    ret = nf_conntrack_init(net);
    if (ret < 0)
        goto out_init;
    ret = nf_conntrack_standalone_init_proc(net);
    if (ret < 0)
        goto out_proc;
    net->ct.sysctl_checksum = 1;
    net->ct.sysctl_log_invalid = 0;
    ret = nf_conntrack_standalone_init_sysctl(net);
    if (ret < 0)
        goto out_sysctl;
    return 0;

out_sysctl:
    nf_conntrack_standalone_fini_proc(net);
out_proc:
    nf_conntrack_cleanup(net);
out_init:
    return ret;
}

static void nf_conntrack_net_exit(struct net *net)
{
    nf_conntrack_standalone_fini_sysctl(net);
    nf_conntrack_standalone_fini_proc(net);
    nf_conntrack_cleanup(net);
}

static struct pernet_operations nf_conntrack_net_ops = {
    .init = nf_conntrack_net_init,
    .exit = nf_conntrack_net_exit,
};

static int __init nf_conntrack_standalone_init(void)
{
    return register_pernet_subsys(&nf_conntrack_net_ops);
}

static void __exit nf_conntrack_standalone_fini(void)
{
    unregister_pernet_subsys(&nf_conntrack_net_ops);
}

module_init(nf_conntrack_standalone_init);
module_exit(nf_conntrack_standalone_fini);

/* Some modules need us, but don't depend directly on any symbol.
   They should call this. */
void need_conntrack(void)
{
}
EXPORT_SYMBOL_GPL(need_conntrack);