Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
em_ipset.c
Go to the documentation of this file.
1 /*
2  * net/sched/em_ipset.c ipset ematch
3  *
4  * Copyright (c) 2012 Florian Westphal <[email protected]>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * version 2 as published by the Free Software Foundation.
9  */
10 
11 #include <linux/gfp.h>
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/skbuff.h>
17 #include <linux/netfilter/xt_set.h>
18 #include <linux/ipv6.h>
19 #include <net/ip.h>
20 #include <net/pkt_cls.h>
21 
22 static int em_ipset_change(struct tcf_proto *tp, void *data, int data_len,
23  struct tcf_ematch *em)
24 {
25  struct xt_set_info *set = data;
27 
28  if (data_len != sizeof(*set))
29  return -EINVAL;
30 
31  index = ip_set_nfnl_get_byindex(set->index);
32  if (index == IPSET_INVALID_ID)
33  return -ENOENT;
34 
35  em->datalen = sizeof(*set);
36  em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
37  if (em->data)
38  return 0;
39 
40  ip_set_nfnl_put(index);
41  return -ENOMEM;
42 }
43 
44 static void em_ipset_destroy(struct tcf_proto *p, struct tcf_ematch *em)
45 {
46  const struct xt_set_info *set = (const void *) em->data;
47  if (set) {
48  ip_set_nfnl_put(set->index);
49  kfree((void *) em->data);
50  }
51 }
52 
53 static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
54  struct tcf_pkt_info *info)
55 {
56  struct ip_set_adt_opt opt;
57  struct xt_action_param acpar;
58  const struct xt_set_info *set = (const void *) em->data;
59  struct net_device *dev, *indev = NULL;
60  int ret, network_offset;
61 
62  switch (skb->protocol) {
63  case htons(ETH_P_IP):
64  acpar.family = 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  acpar.family = 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  acpar.hooknum = 0;
81 
82  opt.family = acpar.family;
83  opt.dim = set->dim;
84  opt.flags = set->flags;
85  opt.cmdflags = 0;
86  opt.timeout = ~0u;
87 
88  network_offset = skb_network_offset(skb);
89  skb_pull(skb, network_offset);
90 
91  dev = skb->dev;
92 
93  rcu_read_lock();
94 
95  if (dev && skb->skb_iif)
96  indev = dev_get_by_index_rcu(dev_net(dev), skb->skb_iif);
97 
98  acpar.in = indev ? indev : dev;
99  acpar.out = dev;
100 
101  ret = ip_set_test(set->index, skb, &acpar, &opt);
102 
103  rcu_read_unlock();
104 
105  skb_push(skb, network_offset);
106  return ret;
107 }
108 
109 static struct tcf_ematch_ops em_ipset_ops = {
110  .kind = TCF_EM_IPSET,
111  .change = em_ipset_change,
112  .destroy = em_ipset_destroy,
113  .match = em_ipset_match,
114  .owner = THIS_MODULE,
115  .link = LIST_HEAD_INIT(em_ipset_ops.link)
116 };
117 
118 static int __init init_em_ipset(void)
119 {
120  return tcf_em_register(&em_ipset_ops);
121 }
122 
123 static void __exit exit_em_ipset(void)
124 {
125  tcf_em_unregister(&em_ipset_ops);
126 }
127 
128 MODULE_LICENSE("GPL");
129 MODULE_AUTHOR("Florian Westphal <[email protected]>");
130 MODULE_DESCRIPTION("TC extended match for IP sets");
131 
132 module_init(init_em_ipset);
133 module_exit(exit_em_ipset);
134