// SPDX-License-Identifier: GPL-2.0/* Kernel module to match connection tracking byte counter. *  (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 boolconnbytes_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;} 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_ratelimited("cannot load conntrack support for proto=%u\n",				    par->family);		return ret;	} 	/*	 * 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;} static void connbytes_mt_destroy(const struct xt_mtdtor_param *par){	nf_ct_netns_put(par->net, par->family);} 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);} static void __exit connbytes_mt_exit(void){	xt_unregister_match(&connbytes_mt_reg);} module_init(connbytes_mt_init);module_exit(connbytes_mt_exit);