Release 4.15 net/netfilter/xt_connbytes.c

/* Kernel module to match connection tracking byte counter.
 * GPL (C) 2002 Martin Devera (devik@cdi.cz).
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/skbuff.h>
#include <linux/math64.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_connbytes.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_acct.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("Xtables: Number of packets/bytes per connection matching");
MODULE_ALIAS("ipt_connbytes");
MODULE_ALIAS("ip6t_connbytes");


static bool

connbytes_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct xt_connbytes_info *sinfo = par->matchinfo;
	const struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	u_int64_t what = 0;	/* initialize to make gcc happy */
	u_int64_t bytes = 0;
	u_int64_t pkts = 0;
	const struct nf_conn_acct *acct;
	const struct nf_conn_counter *counters;

	ct = nf_ct_get(skb, &ctinfo);
	if (!ct)
		return false;

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

	counters = acct->counter;
	switch (sinfo->what) {
	case XT_CONNBYTES_PKTS:
		switch (sinfo->direction) {
		case XT_CONNBYTES_DIR_ORIGINAL:
			what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets);
			break;
		case XT_CONNBYTES_DIR_REPLY:
			what = atomic64_read(&counters[IP_CT_DIR_REPLY].packets);
			break;
		case XT_CONNBYTES_DIR_BOTH:
			what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets);
			what += atomic64_read(&counters[IP_CT_DIR_REPLY].packets);
			break;
		}
		break;
	case XT_CONNBYTES_BYTES:
		switch (sinfo->direction) {
		case XT_CONNBYTES_DIR_ORIGINAL:
			what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes);
			break;
		case XT_CONNBYTES_DIR_REPLY:
			what = atomic64_read(&counters[IP_CT_DIR_REPLY].bytes);
			break;
		case XT_CONNBYTES_DIR_BOTH:
			what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes);
			what += atomic64_read(&counters[IP_CT_DIR_REPLY].bytes);
			break;
		}
		break;
	case XT_CONNBYTES_AVGPKT:
		switch (sinfo->direction) {
		case XT_CONNBYTES_DIR_ORIGINAL:
			bytes = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes);
			pkts  = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets);
			break;
		case XT_CONNBYTES_DIR_REPLY:
			bytes = atomic64_read(&counters[IP_CT_DIR_REPLY].bytes);
			pkts  = atomic64_read(&counters[IP_CT_DIR_REPLY].packets);
			break;
		case XT_CONNBYTES_DIR_BOTH:
			bytes = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes) +
				atomic64_read(&counters[IP_CT_DIR_REPLY].bytes);
			pkts  = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets) +
				atomic64_read(&counters[IP_CT_DIR_REPLY].packets);
			break;
		}
		if (pkts != 0)
			what = div64_u64(bytes, pkts);
		break;
	}

	if (sinfo->count.to >= sinfo->count.from)
		return what <= sinfo->count.to && what >= sinfo->count.from;
	else /* inverted */
		return what < sinfo->count.to || what > sinfo->count.from;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Harald Welte
286
63.13%
2
13.33%
Eric Dumazet
64
14.13%
1
6.67%
Patrick McHardy
48
10.60%
2
13.33%
Florian Westphal
16
3.53%
1
6.67%
Holger Eitzenberger
14
3.09%
1
6.67%
Krzysztof Piotr Oledzki
11
2.43%
1
6.67%
Jan Engelhardt
8
1.77%
5
33.33%
Yasuyuki Kozakai
5
1.10%
1
6.67%
Roman Zippel
1
0.22%
1
6.67%
Total
453
100.00%
15
100.00%



static int connbytes_mt_check(const struct xt_mtchk_param *par)
{
	const struct xt_connbytes_info *sinfo = par->matchinfo;
	int ret;

	if (sinfo->what != XT_CONNBYTES_PKTS &&
	    sinfo->what != XT_CONNBYTES_BYTES &&
	    sinfo->what != XT_CONNBYTES_AVGPKT)
		return -EINVAL;

	if (sinfo->direction != XT_CONNBYTES_DIR_ORIGINAL &&
	    sinfo->direction != XT_CONNBYTES_DIR_REPLY &&
	    sinfo->direction != XT_CONNBYTES_DIR_BOTH)
		return -EINVAL;

	ret = nf_ct_netns_get(par->net, par->family);
	if (ret < 0)
		pr_info("cannot load conntrack support for proto=%u\n",
			par->family);

	/*
         * This filter cannot function correctly unless connection tracking
         * accounting is enabled, so complain in the hope that someone notices.
         */
	if (!nf_ct_acct_enabled(par->net)) {
		pr_warn("Forcing CT accounting to be enabled\n");
		nf_ct_set_acct(par->net, true);
	}

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Harald Welte
57
43.51%
2
15.38%
Jan Engelhardt
26
19.85%
6
46.15%
Tim Gardner
26
19.85%
1
7.69%
Yasuyuki Kozakai
14
10.69%
1
7.69%
Florian Westphal
5
3.82%
1
7.69%
Patrick McHardy
2
1.53%
1
7.69%
Joe Perches
1
0.76%
1
7.69%
Total
131
100.00%
13
100.00%



static void connbytes_mt_destroy(const struct xt_mtdtor_param *par)
{
	nf_ct_netns_put(par->net, par->family);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Yasuyuki Kozakai
13
56.52%
1
25.00%
Florian Westphal
5
21.74%
1
25.00%
Jan Engelhardt
5
21.74%
2
50.00%
Total
23
100.00%
4
100.00%


static struct xt_match connbytes_mt_reg __read_mostly = {
	.name       = "connbytes",
	.revision   = 0,
	.family     = NFPROTO_UNSPEC,
	.checkentry = connbytes_mt_check,
	.match      = connbytes_mt,
	.destroy    = connbytes_mt_destroy,
	.matchsize  = sizeof(struct xt_connbytes_info),
	.me         = THIS_MODULE,
};



static int __init connbytes_mt_init(void)
{
	return xt_register_match(&connbytes_mt_reg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Harald Welte
11
68.75%
2
40.00%
Jan Engelhardt
4
25.00%
2
40.00%
Patrick McHardy
1
6.25%
1
20.00%
Total
16
100.00%
5
100.00%



static void __exit connbytes_mt_exit(void)
{
	xt_unregister_match(&connbytes_mt_reg);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Harald Welte
10
66.67%
1
25.00%
Jan Engelhardt
4
26.67%
2
50.00%
Patrick McHardy
1
6.67%
1
25.00%
Total
15
100.00%
4
100.00%


module_init(connbytes_mt_init);

module_exit(connbytes_mt_exit);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Harald Welte
431
56.94%
2
5.88%
Patrick McHardy
69
9.11%
7
20.59%
Jan Engelhardt
69
9.11%
14
41.18%
Eric Dumazet
64
8.45%
1
2.94%
Yasuyuki Kozakai
36
4.76%
2
5.88%
Tim Gardner
26
3.43%
1
2.94%
Florian Westphal
26
3.43%
2
5.88%
Holger Eitzenberger
14
1.85%
1
2.94%
Krzysztof Piotr Oledzki
14
1.85%
1
2.94%
Roman Zippel
5
0.66%
1
2.94%
Jiri Slaby
2
0.26%
1
2.94%
Joe Perches
1
0.13%
1
2.94%
Total
757
100.00%
34
100.00%
Directory: net/netfilter

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