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 nf_hook_state *state)
  24 {
  25         struct nft_pktinfo pkt;
  26
  27         nft_set_pktinfo_ipv4(&pkt, ops, skb, state);
  28
  29         return nft_do_chain(&pkt, ops);
  30 }
  31
  32 static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
  33                                     struct sk_buff *skb,
  34                                     const struct nf_hook_state *state)
  35 {
  36         if (unlikely(skb->len < sizeof(struct iphdr) ||
  37                      ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
  38                 if (net_ratelimit())
  39                         pr_info("nf_tables_ipv4: ignoring short SOCK_RAW "
  40                                 "packet\n");
  41                 return NF_ACCEPT;
  42         }
  43
  44         return nft_do_chain_ipv4(ops, skb, state);
  45 }
  46
  47 struct nft_af_info nft_af_ipv4 __read_mostly = {
  48         .family         = NFPROTO_IPV4,
  49         .nhooks         = NF_INET_NUMHOOKS,
  50         .owner          = THIS_MODULE,
  51         .nops           = 1,
  52         .hooks          = {
  53                 [NF_INET_LOCAL_IN]      = nft_do_chain_ipv4,
  54                 [NF_INET_LOCAL_OUT]     = nft_ipv4_output,
  55                 [NF_INET_FORWARD]       = nft_do_chain_ipv4,
  56                 [NF_INET_PRE_ROUTING]   = nft_do_chain_ipv4,
  57                 [NF_INET_POST_ROUTING]  = nft_do_chain_ipv4,
  58         },
  59 };
  60 EXPORT_SYMBOL_GPL(nft_af_ipv4);
  61
  62 static int nf_tables_ipv4_init_net(struct net *net)
  63 {
  64         net->nft.ipv4 = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
  65         if (net->nft.ipv4 == NULL)
  66                 return -ENOMEM;
  67
  68         memcpy(net->nft.ipv4, &nft_af_ipv4, sizeof(nft_af_ipv4));
  69
  70         if (nft_register_afinfo(net, net->nft.ipv4) < 0)
  71                 goto err;
  72
  73         return 0;
  74 err:
  75         kfree(net->nft.ipv4);
  76         return -ENOMEM;
  77 }
  78
  79 static void nf_tables_ipv4_exit_net(struct net *net)
  80 {
  81         nft_unregister_afinfo(net->nft.ipv4);
  82         kfree(net->nft.ipv4);
  83 }
  84
  85 static struct pernet_operations nf_tables_ipv4_net_ops = {
  86         .init   = nf_tables_ipv4_init_net,
  87         .exit   = nf_tables_ipv4_exit_net,
  88 };
  89
  90 static const struct nf_chain_type filter_ipv4 = {
  91         .name           = "filter",
  92         .type           = NFT_CHAIN_T_DEFAULT,
  93         .family         = NFPROTO_IPV4,
  94         .owner          = THIS_MODULE,
  95         .hook_mask      = (1 << NF_INET_LOCAL_IN) |
  96                           (1 << NF_INET_LOCAL_OUT) |
  97                           (1 << NF_INET_FORWARD) |
  98                           (1 << NF_INET_PRE_ROUTING) |
  99                           (1 << NF_INET_POST_ROUTING),
 100 };
 101
 102 static int __init nf_tables_ipv4_init(void)
 103 {
 104         int ret;
 105
 106         nft_register_chain_type(&filter_ipv4);
 107         ret = register_pernet_subsys(&nf_tables_ipv4_net_ops);
 108         if (ret < 0)
 109                 nft_unregister_chain_type(&filter_ipv4);
 110
 111         return ret;
 112 }
 113
 114 static void __exit nf_tables_ipv4_exit(void)
 115 {
 116         unregister_pernet_subsys(&nf_tables_ipv4_net_ops);
 117         nft_unregister_chain_type(&filter_ipv4);
 118 }
 119
 120 module_init(nf_tables_ipv4_init);
 121 module_exit(nf_tables_ipv4_exit);
 122
 123 MODULE_LICENSE("GPL");
 124 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 125 MODULE_ALIAS_NFT_FAMILY(AF_INET);