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/net_namespace.h>
  20 #include <net/netfilter/nf_tables_ipv4.h>
  21
  22 static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
  23                                     struct sk_buff *skb,
  24                                     const struct net_device *in,
  25                                     const struct net_device *out,
  26                                     int (*okfn)(struct sk_buff *))
  27 {
  28         struct nft_pktinfo pkt;
  29
  30         if (unlikely(skb->len < sizeof(struct iphdr) ||
  31                      ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
  32                 if (net_ratelimit())
  33                         pr_info("nf_tables_ipv4: ignoring short SOCK_RAW "
  34                                 "packet\n");
  35                 return NF_ACCEPT;
  36         }
  37         nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
  38
  39         return nft_do_chain_pktinfo(&pkt, ops);
  40 }
  41
  42 static struct nft_af_info nft_af_ipv4 __read_mostly = {
  43         .family         = NFPROTO_IPV4,
  44         .nhooks         = NF_INET_NUMHOOKS,
  45         .owner          = THIS_MODULE,
  46         .hooks          = {
  47                 [NF_INET_LOCAL_OUT]     = nft_ipv4_output,
  48         },
  49 };
  50
  51 static int nf_tables_ipv4_init_net(struct net *net)
  52 {
  53         net->nft.ipv4 = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
  54         if (net->nft.ipv4 == NULL)
  55                 return -ENOMEM;
  56
  57         memcpy(net->nft.ipv4, &nft_af_ipv4, sizeof(nft_af_ipv4));
  58
  59         if (nft_register_afinfo(net, net->nft.ipv4) < 0)
  60                 goto err;
  61
  62         return 0;
  63 err:
  64         kfree(net->nft.ipv4);
  65         return -ENOMEM;
  66 }
  67
  68 static void nf_tables_ipv4_exit_net(struct net *net)
  69 {
  70         nft_unregister_afinfo(net->nft.ipv4);
  71         kfree(net->nft.ipv4);
  72 }
  73
  74 static struct pernet_operations nf_tables_ipv4_net_ops = {
  75         .init   = nf_tables_ipv4_init_net,
  76         .exit   = nf_tables_ipv4_exit_net,
  77 };
  78
  79 static unsigned int
  80 nft_do_chain_ipv4(const struct nf_hook_ops *ops,
  81                   struct sk_buff *skb,
  82                   const struct net_device *in,
  83                   const struct net_device *out,
  84                   int (*okfn)(struct sk_buff *))
  85 {
  86         struct nft_pktinfo pkt;
  87
  88         nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
  89
  90         return nft_do_chain_pktinfo(&pkt, ops);
  91 }
  92
  93 static struct nf_chain_type filter_ipv4 = {
  94         .family         = NFPROTO_IPV4,
  95         .name           = "filter",
  96         .type           = NFT_CHAIN_T_DEFAULT,
  97         .hook_mask      = (1 << NF_INET_LOCAL_IN) |
  98                           (1 << NF_INET_LOCAL_OUT) |
  99                           (1 << NF_INET_FORWARD) |
 100                           (1 << NF_INET_PRE_ROUTING) |
 101                           (1 << NF_INET_POST_ROUTING),
 102         .fn             = {
 103                 [NF_INET_LOCAL_IN]      = nft_do_chain_ipv4,
 104                 [NF_INET_LOCAL_OUT]     = nft_ipv4_output,
 105                 [NF_INET_FORWARD]       = nft_do_chain_ipv4,
 106                 [NF_INET_PRE_ROUTING]   = nft_do_chain_ipv4,
 107                 [NF_INET_POST_ROUTING]  = nft_do_chain_ipv4,
 108         },
 109 };
 110
 111 static int __init nf_tables_ipv4_init(void)
 112 {
 113         nft_register_chain_type(&filter_ipv4);
 114         return register_pernet_subsys(&nf_tables_ipv4_net_ops);
 115 }
 116
 117 static void __exit nf_tables_ipv4_exit(void)
 118 {
 119         unregister_pernet_subsys(&nf_tables_ipv4_net_ops);
 120         nft_unregister_chain_type(&filter_ipv4);
 121 }
 122
 123 module_init(nf_tables_ipv4_init);
 124 module_exit(nf_tables_ipv4_exit);
 125
 126 MODULE_LICENSE("GPL");
 127 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 128 MODULE_ALIAS_NFT_FAMILY(AF_INET);