// SPDX-License-Identifier: GPL-2.0-only/* *	xt_ipvs - kernel module to match IPVS connection properties * *	Author: Hannes Eder <heder@google.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h>#include <linux/moduleparam.h>#include <linux/spinlock.h>#include <linux/skbuff.h>#ifdef CONFIG_IP_VS_IPV6#include <net/ipv6.h>#endif#include <linux/ip_vs.h>#include <linux/types.h>#include <linux/netfilter/x_tables.h>#include <linux/netfilter/xt_ipvs.h>#include <net/netfilter/nf_conntrack.h> #include <net/ip_vs.h> MODULE_AUTHOR("Hannes Eder <heder@google.com>");MODULE_DESCRIPTION("Xtables: match IPVS connection properties");MODULE_LICENSE("GPL");MODULE_ALIAS("ipt_ipvs");MODULE_ALIAS("ip6t_ipvs"); /* borrowed from xt_conntrack */static bool ipvs_mt_addrcmp(const union nf_inet_addr *kaddr,			    const union nf_inet_addr *uaddr,			    const union nf_inet_addr *umask,			    unsigned int l3proto){	if (l3proto == NFPROTO_IPV4)		return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0;#ifdef CONFIG_IP_VS_IPV6	else if (l3proto == NFPROTO_IPV6)		return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6,		       &uaddr->in6) == 0;#endif	else		return false;} static boolipvs_mt(const struct sk_buff *skb, struct xt_action_param *par){	const struct xt_ipvs_mtinfo *data = par->matchinfo;	struct netns_ipvs *ipvs = net_ipvs(xt_net(par));	/* ipvs_mt_check ensures that family is only NFPROTO_IPV[46]. */	const u_int8_t family = xt_family(par);	struct ip_vs_iphdr iph;	struct ip_vs_protocol *pp;	struct ip_vs_conn *cp;	bool match = true; 	if (data->bitmask == XT_IPVS_IPVS_PROPERTY) {		match = skb->ipvs_property ^			!!(data->invert & XT_IPVS_IPVS_PROPERTY);		goto out;	} 	/* other flags than XT_IPVS_IPVS_PROPERTY are set */	if (!skb->ipvs_property) {		match = false;		goto out;	} 	ip_vs_fill_iph_skb(family, skb, true, &iph); 	if (data->bitmask & XT_IPVS_PROTO)		if ((iph.protocol == data->l4proto) ^		    !(data->invert & XT_IPVS_PROTO)) {			match = false;			goto out;		} 	pp = ip_vs_proto_get(iph.protocol);	if (unlikely(!pp)) {		match = false;		goto out;	} 	/*	 * Check if the packet belongs to an existing entry	 */	cp = pp->conn_out_get(ipvs, family, skb, &iph);	if (unlikely(cp == NULL)) {		match = false;		goto out;	} 	/*	 * We found a connection, i.e. ct != 0, make sure to call	 * __ip_vs_conn_put before returning.  In our case jump to out_put_con.	 */ 	if (data->bitmask & XT_IPVS_VPORT)		if ((cp->vport == data->vport) ^		    !(data->invert & XT_IPVS_VPORT)) {			match = false;			goto out_put_cp;		} 	if (data->bitmask & XT_IPVS_VPORTCTL)		if ((cp->control != NULL &&		     cp->control->vport == data->vportctl) ^		    !(data->invert & XT_IPVS_VPORTCTL)) {			match = false;			goto out_put_cp;		} 	if (data->bitmask & XT_IPVS_DIR) {		enum ip_conntrack_info ctinfo;		struct nf_conn *ct = nf_ct_get(skb, &ctinfo); 		if (ct == NULL) {			match = false;			goto out_put_cp;		} 		if ((ctinfo >= IP_CT_IS_REPLY) ^		    !!(data->invert & XT_IPVS_DIR)) {			match = false;			goto out_put_cp;		}	} 	if (data->bitmask & XT_IPVS_METHOD)		if (((cp->flags & IP_VS_CONN_F_FWD_MASK) == data->fwd_method) ^		    !(data->invert & XT_IPVS_METHOD)) {			match = false;			goto out_put_cp;		} 	if (data->bitmask & XT_IPVS_VADDR) {		if (ipvs_mt_addrcmp(&cp->vaddr, &data->vaddr,				    &data->vmask, family) ^		    !(data->invert & XT_IPVS_VADDR)) {			match = false;			goto out_put_cp;		}	} out_put_cp:	__ip_vs_conn_put(cp);out:	return match;} static int ipvs_mt_check(const struct xt_mtchk_param *par){	if (par->family != NFPROTO_IPV4#ifdef CONFIG_IP_VS_IPV6	    && par->family != NFPROTO_IPV6#endif		) {		pr_info_ratelimited("protocol family %u not supported\n",				    par->family);		return -EINVAL;	} 	return 0;} static struct xt_match xt_ipvs_mt_reg __read_mostly = {	.name       = "ipvs",	.revision   = 0,	.family     = NFPROTO_UNSPEC,	.match      = ipvs_mt,	.checkentry = ipvs_mt_check,	.matchsize  = XT_ALIGN(sizeof(struct xt_ipvs_mtinfo)),	.me         = THIS_MODULE,}; static int __init ipvs_mt_init(void){	return xt_register_match(&xt_ipvs_mt_reg);} static void __exit ipvs_mt_exit(void){	xt_unregister_match(&xt_ipvs_mt_reg);} module_init(ipvs_mt_init);module_exit(ipvs_mt_exit);