1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * net/sched/em_ipset.c	ipset ematch
  4 *
  5 * Copyright (c) 2012 Florian Westphal <fw@strlen.de>
  6 */
  7
  8#include <linux/gfp.h>
  9#include <linux/module.h>
 10#include <linux/types.h>
 11#include <linux/kernel.h>
 12#include <linux/string.h>
 13#include <linux/skbuff.h>
 14#include <linux/netfilter/xt_set.h>
 15#include <linux/ipv6.h>
 16#include <net/ip.h>
 17#include <net/pkt_cls.h>
 18
 19static int em_ipset_change(struct net *net, void *data, int data_len,
 20			   struct tcf_ematch *em)
 21{
 22	struct xt_set_info *set = data;
 23	ip_set_id_t index;
 24
 25	if (data_len != sizeof(*set))
 26		return -EINVAL;
 27
 28	index = ip_set_nfnl_get_byindex(net, set->index);
 29	if (index == IPSET_INVALID_ID)
 30		return -ENOENT;
 31
 32	em->datalen = sizeof(*set);
 33	em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
 34	if (em->data)
 35		return 0;
 36
 37	ip_set_nfnl_put(net, index);
 38	return -ENOMEM;
 39}
 40
 41static void em_ipset_destroy(struct tcf_ematch *em)
 42{
 43	const struct xt_set_info *set = (const void *) em->data;
 44	if (set) {
 45		ip_set_nfnl_put(em->net, set->index);
 46		kfree((void *) em->data);
 47	}
 48}
 49
 50static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
 51			  struct tcf_pkt_info *info)
 52{
 53	struct ip_set_adt_opt opt;
 54	struct xt_action_param acpar;
 55	const struct xt_set_info *set = (const void *) em->data;
 56	struct net_device *dev, *indev = NULL;
 57	struct nf_hook_state state = {
 58		.net	= em->net,
 59	};
 60	int ret, network_offset;
 61
 62	switch (tc_skb_protocol(skb)) {
 63	case htons(ETH_P_IP):
 64		state.pf = NFPROTO_IPV4;
 65		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
 66			return 0;
 67		acpar.thoff = ip_hdrlen(skb);
 68		break;
 69	case htons(ETH_P_IPV6):
 70		state.pf = NFPROTO_IPV6;
 71		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
 72			return 0;
 73		/* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
 74		acpar.thoff = sizeof(struct ipv6hdr);
 75		break;
 76	default:
 77		return 0;
 78	}
 79
 80	opt.family = state.pf;
 81	opt.dim = set->dim;
 82	opt.flags = set->flags;
 83	opt.cmdflags = 0;
 84	opt.ext.timeout = ~0u;
 85
 86	network_offset = skb_network_offset(skb);
 87	skb_pull(skb, network_offset);
 88
 89	dev = skb->dev;
 90
 91	rcu_read_lock();
 92
 93	if (skb->skb_iif)
 94		indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
 95
 96	state.in      = indev ? indev : dev;
 97	state.out     = dev;
 98	acpar.state   = &state;
 99
100	ret = ip_set_test(set->index, skb, &acpar, &opt);
101
102	rcu_read_unlock();
103
104	skb_push(skb, network_offset);
105	return ret;
106}
107
108static struct tcf_ematch_ops em_ipset_ops = {
109	.kind	  = TCF_EM_IPSET,
110	.change	  = em_ipset_change,
111	.destroy  = em_ipset_destroy,
112	.match	  = em_ipset_match,
113	.owner	  = THIS_MODULE,
114	.link	  = LIST_HEAD_INIT(em_ipset_ops.link)
115};
116
117static int __init init_em_ipset(void)
118{
119	return tcf_em_register(&em_ipset_ops);
120}
121
122static void __exit exit_em_ipset(void)
123{
124	tcf_em_unregister(&em_ipset_ops);
125}
126
127MODULE_LICENSE("GPL");
128MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
129MODULE_DESCRIPTION("TC extended match for IP sets");
130
131module_init(init_em_ipset);
132module_exit(exit_em_ipset);
133
134MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);