net/ipv4/netfilter/nf_tables_ipv4.c

   1 /*
   2  * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
   3  * Copyright (c) 2012-2013 Pablo Neira Ayuso <pablo@netfilter.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Development of this code funded by Astaro AG (http://www.astaro.com/)
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/ip.h>
  15 #include <linux/netfilter_ipv4.h>
  16 #include <net/netfilter/nf_tables.h>
  17 #include <net/net_namespace.h>
  18 #include <net/ip.h>
  19 #include <net/netfilter/nf_tables_ipv4.h>
  20
  21 static unsigned int nft_do_chain_ipv4(const struct nf_hook_ops *ops,
  22                                       struct sk_buff *skb,
  23                                       const struct net_device *in,
  24                                       const struct net_device *out,
  25                                       int (*okfn)(struct sk_buff *))
  26 {
  27         struct nft_pktinfo pkt;
  28
  29         nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
  30
  31         return nft_do_chain_pktinfo(&pkt, ops);
  32 }
  33
  34 static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
  35                                     struct sk_buff *skb,
  36                                     const struct net_device *in,
  37                                     const struct net_device *out,
  38                                     int (*okfn)(struct sk_buff *))
  39 {
  40         if (unlikely(skb->len < sizeof(struct iphdr) ||
  41                      ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
  42                 if (net_ratelimit())
  43                         pr_info("nf_tables_ipv4: ignoring short SOCK_RAW "
  44                                 "packet\n");
  45                 return NF_ACCEPT;
  46         }
  47
  48         return nft_do_chain_ipv4(ops, skb, in, out, okfn);
  49 }
  50
  51 struct nft_af_info nft_af_ipv4 __read_mostly = {
  52         .family         = NFPROTO_IPV4,
  53         .nhooks         = NF_INET_NUMHOOKS,
  54         .owner          = THIS_MODULE,
  55         .nops           = 1,
  56         .hooks          = {
  57                 [NF_INET_LOCAL_IN]      = nft_do_chain_ipv4,
  58                 [NF_INET_LOCAL_OUT]     = nft_ipv4_output,
  59                 [NF_INET_FORWARD]       = nft_do_chain_ipv4,
  60                 [NF_INET_PRE_ROUTING]   = nft_do_chain_ipv4,
  61                 [NF_INET_POST_ROUTING]  = nft_do_chain_ipv4,
  62         },
  63 };
  64 EXPORT_SYMBOL_GPL(nft_af_ipv4);
  65
  66 static int nf_tables_ipv4_init_net(struct net *net)
  67 {
  68         net->nft.ipv4 = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
  69         if (net->nft.ipv4 == NULL)
  70                 return -ENOMEM;
  71
  72         memcpy(net->nft.ipv4, &nft_af_ipv4, sizeof(nft_af_ipv4));
  73
  74         if (nft_register_afinfo(net, net->nft.ipv4) < 0)
  75                 goto err;
  76
  77         return 0;
  78 err:
  79         kfree(net->nft.ipv4);
  80         return -ENOMEM;
  81 }
  82
  83 static void nf_tables_ipv4_exit_net(struct net *net)
  84 {
  85         nft_unregister_afinfo(net->nft.ipv4);
  86         kfree(net->nft.ipv4);
  87 }
  88
  89 static struct pernet_operations nf_tables_ipv4_net_ops = {
  90         .init   = nf_tables_ipv4_init_net,
  91         .exit   = nf_tables_ipv4_exit_net,
  92 };
  93
  94 static const struct nf_chain_type filter_ipv4 = {
  95         .name           = "filter",
  96         .type           = NFT_CHAIN_T_DEFAULT,
  97         .family         = NFPROTO_IPV4,
  98         .owner          = THIS_MODULE,
  99         .hook_mask      = (1 << NF_INET_LOCAL_IN) |
 100                           (1 << NF_INET_LOCAL_OUT) |
 101                           (1 << NF_INET_FORWARD) |
 102                           (1 << NF_INET_PRE_ROUTING) |
 103                           (1 << NF_INET_POST_ROUTING),
 104 };
 105
 106 static int __init nf_tables_ipv4_init(void)
 107 {
 108         nft_register_chain_type(&filter_ipv4);
 109         return register_pernet_subsys(&nf_tables_ipv4_net_ops);
 110 }
 111
 112 static void __exit nf_tables_ipv4_exit(void)
 113 {
 114         unregister_pernet_subsys(&nf_tables_ipv4_net_ops);
 115         nft_unregister_chain_type(&filter_ipv4);
 116 }
 117
 118 module_init(nf_tables_ipv4_init);
 119 module_exit(nf_tables_ipv4_exit);
 120
 121 MODULE_LICENSE("GPL");
 122 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 123 MODULE_ALIAS_NFT_FAMILY(AF_INET);