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
19 static 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
41 static 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
50 static 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 (skb_protocol(skb, true)) {
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
108 static 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
117 static int __init init_em_ipset(void)
118 {
119 return tcf_em_register(&em_ipset_ops);
120 }
121
122 static void __exit exit_em_ipset(void)
123 {
124 tcf_em_unregister(&em_ipset_ops);
125 }
126
127 MODULE_LICENSE("GPL");
128 MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
129 MODULE_DESCRIPTION("TC extended match for IP sets");
130
131 module_init(init_em_ipset);
132 module_exit(exit_em_ipset);
133
134 MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);
135
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