netfilter: nf_tables: add "inet" table for IPv4/IPv6

This patch adds a new table family and a new filter chain that you can
use to attach IPv4 and IPv6 rules. This should help to simplify
rule-set maintainance in dual-stack setups.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

5 files changed, 110 insertions, 2 deletions

diff --git a/net/ipv4/netfilter/nf_tables_ipv4.c b/net/ipv4/netfilter/nf_tables_ipv4.c
index 177c3bceb7ca..da927dc9f636 100644
--- a/net/ipv4/netfilter/nf_tables_ipv4.c
+++ b/net/ipv4/netfilter/nf_tables_ipv4.c
@@ -48,7 +48,7 @@ static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
         return nft_do_chain_ipv4(ops, skb, in, out, okfn);
 }
 
-static struct nft_af_info nft_af_ipv4 __read_mostly = {
+struct nft_af_info nft_af_ipv4 __read_mostly = {
         .family         = NFPROTO_IPV4,
         .nhooks         = NF_INET_NUMHOOKS,
         .owner          = THIS_MODULE,
@@ -61,6 +61,7 @@ static struct nft_af_info nft_af_ipv4 __read_mostly = {
                 [NF_INET_POST_ROUTING]  = nft_do_chain_ipv4,
         },
 };
+EXPORT_SYMBOL_GPL(nft_af_ipv4);
 
 static int nf_tables_ipv4_init_net(struct net *net)
 {
diff --git a/net/ipv6/netfilter/nf_tables_ipv6.c b/net/ipv6/netfilter/nf_tables_ipv6.c
index 642280e44b65..025e7f4e8ac5 100644
--- a/net/ipv6/netfilter/nf_tables_ipv6.c
+++ b/net/ipv6/netfilter/nf_tables_ipv6.c
@@ -47,7 +47,7 @@ static unsigned int nft_ipv6_output(const struct nf_hook_ops *ops,
         return nft_do_chain_ipv6(ops, skb, in, out, okfn);
 }
 
-static struct nft_af_info nft_af_ipv6 __read_mostly = {
+struct nft_af_info nft_af_ipv6 __read_mostly = {
         .family         = NFPROTO_IPV6,
         .nhooks         = NF_INET_NUMHOOKS,
         .owner          = THIS_MODULE,
@@ -60,6 +60,7 @@ static struct nft_af_info nft_af_ipv6 __read_mostly = {
                 [NF_INET_POST_ROUTING]  = nft_do_chain_ipv6,
         },
 };
+EXPORT_SYMBOL_GPL(nft_af_ipv6);
 
 static int nf_tables_ipv6_init_net(struct net *net)
 {
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index c3b3b26c4c4e..37d2092705a7 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -428,6 +428,14 @@ config NF_TABLES
 
           To compile it as a module, choose M here.
 
+config NF_TABLES_INET
+        depends on NF_TABLES
+        select NF_TABLES_IPV4
+        select NF_TABLES_IPV6
+        tristate "Netfilter nf_tables mixed IPv4/IPv6 tables support"
+        help
+          This option enables support for a mixed IPv4/IPv6 "inet" table.
+
 config NFT_EXTHDR
         depends on NF_TABLES
         tristate "Netfilter nf_tables IPv6 exthdr module"
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 78b4e1c9c595..74c066109334 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -70,6 +70,7 @@ nf_tables-objs += nft_immediate.o nft_cmp.o nft_lookup.o
 nf_tables-objs += nft_bitwise.o nft_byteorder.o nft_payload.o
 
 obj-$(CONFIG_NF_TABLES)         += nf_tables.o
+obj-$(CONFIG_NF_TABLES_INET)    += nf_tables_inet.o
 obj-$(CONFIG_NFT_COMPAT)        += nft_compat.o
 obj-$(CONFIG_NFT_EXTHDR)        += nft_exthdr.o
 obj-$(CONFIG_NFT_META)          += nft_meta.o
diff --git a/net/netfilter/nf_tables_inet.c b/net/netfilter/nf_tables_inet.c
new file mode 100644
index 000000000000..ac0edcb549de
--- /dev/null
+++ b/net/netfilter/nf_tables_inet.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2012-2014 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/ip.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_ipv4.h>
+#include <net/netfilter/nf_tables_ipv6.h>
+#include <net/ip.h>
+
+static void nft_inet_hook_ops_init(struct nf_hook_ops *ops, unsigned int n)
+{
+        struct nft_af_info *afi;
+
+        if (n == 1)
+                afi = &nft_af_ipv4;
+        else
+                afi = &nft_af_ipv6;
+
+        ops->pf = afi->family;
+        if (afi->hooks[ops->hooknum])
+                ops->hook = afi->hooks[ops->hooknum];
+}
+
+static struct nft_af_info nft_af_inet __read_mostly = {
+        .family         = NFPROTO_INET,
+        .nhooks         = NF_INET_NUMHOOKS,
+        .owner          = THIS_MODULE,
+        .nops           = 2,
+        .hook_ops_init  = nft_inet_hook_ops_init,
+};
+
+static int __net_init nf_tables_inet_init_net(struct net *net)
+{
+        net->nft.inet = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
+        if (net->nft.inet == NULL)
+                return -ENOMEM;
+        memcpy(net->nft.inet, &nft_af_inet, sizeof(nft_af_inet));
+
+        if (nft_register_afinfo(net, net->nft.inet) < 0)
+                goto err;
+
+        return 0;
+
+err:
+        kfree(net->nft.inet);
+        return -ENOMEM;
+}
+
+static void __net_exit nf_tables_inet_exit_net(struct net *net)
+{
+        nft_unregister_afinfo(net->nft.inet);
+        kfree(net->nft.inet);
+}
+
+static struct pernet_operations nf_tables_inet_net_ops = {
+        .init   = nf_tables_inet_init_net,
+        .exit   = nf_tables_inet_exit_net,
+};
+
+static struct nf_chain_type filter_inet = {
+        .family         = NFPROTO_INET,
+        .name           = "filter",
+        .type           = NFT_CHAIN_T_DEFAULT,
+        .hook_mask      = (1 << NF_INET_LOCAL_IN) |
+                          (1 << NF_INET_LOCAL_OUT) |
+                          (1 << NF_INET_FORWARD) |
+                          (1 << NF_INET_PRE_ROUTING) |
+                          (1 << NF_INET_POST_ROUTING),
+};
+
+static int __init nf_tables_inet_init(void)
+{
+        nft_register_chain_type(&filter_inet);
+        return register_pernet_subsys(&nf_tables_inet_net_ops);
+}
+
+static void __exit nf_tables_inet_exit(void)
+{
+        unregister_pernet_subsys(&nf_tables_inet_net_ops);
+        nft_unregister_chain_type(&filter_inet);
+}
+
+module_init(nf_tables_inet_init);
+module_exit(nf_tables_inet_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS_NFT_FAMILY(1);