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_ipv4_output(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         if (unlikely(skb->len < sizeof(struct iphdr) ||
  30                      ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
  31                 if (net_ratelimit())
  32                         pr_info("nf_tables_ipv4: ignoring short SOCK_RAW "
  33                                 "packet\n");
  34                 return NF_ACCEPT;
  35         }
  36         nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
  37
  38         return nft_do_chain_pktinfo(&pkt, ops);
  39 }
  40
  41 static struct nft_af_info nft_af_ipv4 __read_mostly = {
  42         .family         = NFPROTO_IPV4,
  43         .nhooks         = NF_INET_NUMHOOKS,
  44         .owner          = THIS_MODULE,
  45         .hooks          = {
  46                 [NF_INET_LOCAL_OUT]     = nft_ipv4_output,
  47         },
  48 };
  49
  50 static int nf_tables_ipv4_init_net(struct net *net)
  51 {
  52         net->nft.ipv4 = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
  53         if (net->nft.ipv4 == NULL)
  54                 return -ENOMEM;
  55
  56         memcpy(net->nft.ipv4, &nft_af_ipv4, sizeof(nft_af_ipv4));
  57
  58         if (nft_register_afinfo(net, net->nft.ipv4) < 0)
  59                 goto err;
  60
  61         return 0;
  62 err:
  63         kfree(net->nft.ipv4);
  64         return -ENOMEM;
  65 }
  66
  67 static void nf_tables_ipv4_exit_net(struct net *net)
  68 {
  69         nft_unregister_afinfo(net->nft.ipv4);
  70         kfree(net->nft.ipv4);
  71 }
  72
  73 static struct pernet_operations nf_tables_ipv4_net_ops = {
  74         .init   = nf_tables_ipv4_init_net,
  75         .exit   = nf_tables_ipv4_exit_net,
  76 };
  77
  78 static unsigned int
  79 nft_do_chain_ipv4(const struct nf_hook_ops *ops,
  80                   struct sk_buff *skb,
  81                   const struct net_device *in,
  82                   const struct net_device *out,
  83                   int (*okfn)(struct sk_buff *))
  84 {
  85         struct nft_pktinfo pkt;
  86
  87         nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
  88
  89         return nft_do_chain_pktinfo(&pkt, ops);
  90 }
  91
  92 static struct nf_chain_type filter_ipv4 = {
  93         .family         = NFPROTO_IPV4,
  94         .name           = "filter",
  95         .type           = NFT_CHAIN_T_DEFAULT,
  96         .hook_mask      = (1 << NF_INET_LOCAL_IN) |
  97                           (1 << NF_INET_LOCAL_OUT) |
  98                           (1 << NF_INET_FORWARD) |
  99                           (1 << NF_INET_PRE_ROUTING) |
 100                           (1 << NF_INET_POST_ROUTING),
 101         .fn             = {
 102                 [NF_INET_LOCAL_IN]      = nft_do_chain_ipv4,
 103                 [NF_INET_LOCAL_OUT]     = nft_ipv4_output,
 104                 [NF_INET_FORWARD]       = nft_do_chain_ipv4,
 105                 [NF_INET_PRE_ROUTING]   = nft_do_chain_ipv4,
 106                 [NF_INET_POST_ROUTING]  = nft_do_chain_ipv4,
 107         },
 108 };
 109
 110 static int __init nf_tables_ipv4_init(void)
 111 {
 112         nft_register_chain_type(&filter_ipv4);
 113         return register_pernet_subsys(&nf_tables_ipv4_net_ops);
 114 }
 115
 116 static void __exit nf_tables_ipv4_exit(void)
 117 {
 118         unregister_pernet_subsys(&nf_tables_ipv4_net_ops);
 119         nft_unregister_chain_type(&filter_ipv4);
 120 }
 121
 122 module_init(nf_tables_ipv4_init);
 123 module_exit(nf_tables_ipv4_exit);
 124
 125 MODULE_LICENSE("GPL");
 126 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 127 MODULE_ALIAS_NFT_FAMILY(AF_INET);