netfilter: nf_tables: build-in filter chain type

One module per supported filter chain family type takes too much memory
for very little code - too much modularization - place all chain filter
definitions in one single file.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 398 insertions, 0 deletions

diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c
new file mode 100644
index 000000000000..84c902477a91
--- /dev/null
+++ b/net/netfilter/nft_chain_filter.c
@@ -0,0 +1,398 @@
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <net/net_namespace.h>
+#include <net/netfilter/nf_tables.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter_bridge.h>
+#include <linux/netfilter_arp.h>
+#include <net/netfilter/nf_tables_ipv4.h>
+#include <net/netfilter/nf_tables_ipv6.h>
+
+#ifdef CONFIG_NF_TABLES_IPV4
+static unsigned int nft_do_chain_ipv4(void *priv,
+				      struct sk_buff *skb,
+				      const struct nf_hook_state *state)
+{
+	struct nft_pktinfo pkt;
+
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_ipv4(&pkt, skb);
+
+	return nft_do_chain(&pkt, priv);
+}
+
+static const struct nft_chain_type nft_chain_filter_ipv4 = {
+	.name		= "filter",
+	.type		= NFT_CHAIN_T_DEFAULT,
+	.family		= NFPROTO_IPV4,
+	.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),
+	.hooks		= {
+		[NF_INET_LOCAL_IN]	= nft_do_chain_ipv4,
+		[NF_INET_LOCAL_OUT]	= nft_do_chain_ipv4,
+		[NF_INET_FORWARD]	= nft_do_chain_ipv4,
+		[NF_INET_PRE_ROUTING]	= nft_do_chain_ipv4,
+		[NF_INET_POST_ROUTING]	= nft_do_chain_ipv4,
+	},
+};
+
+static void nft_chain_filter_ipv4_init(void)
+{
+	nft_register_chain_type(&nft_chain_filter_ipv4);
+}
+static void nft_chain_filter_ipv4_fini(void)
+{
+	nft_unregister_chain_type(&nft_chain_filter_ipv4);
+}
+
+#else
+static inline void nft_chain_filter_ipv4_init(void) {}
+static inline void nft_chain_filter_ipv4_fini(void) {}
+#endif /* CONFIG_NF_TABLES_IPV4 */
+
+#ifdef CONFIG_NF_TABLES_ARP
+static unsigned int nft_do_chain_arp(void *priv, struct sk_buff *skb,
+				     const struct nf_hook_state *state)
+{
+	struct nft_pktinfo pkt;
+
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_unspec(&pkt, skb);
+
+	return nft_do_chain(&pkt, priv);
+}
+
+static const struct nft_chain_type nft_chain_filter_arp = {
+	.name		= "filter",
+	.type		= NFT_CHAIN_T_DEFAULT,
+	.family		= NFPROTO_ARP,
+	.owner		= THIS_MODULE,
+	.hook_mask	= (1 << NF_ARP_IN) |
+			  (1 << NF_ARP_OUT),
+	.hooks		= {
+		[NF_ARP_IN]		= nft_do_chain_arp,
+		[NF_ARP_OUT]		= nft_do_chain_arp,
+	},
+};
+
+static void nft_chain_filter_arp_init(void)
+{
+	nft_register_chain_type(&nft_chain_filter_arp);
+}
+
+static void nft_chain_filter_arp_fini(void)
+{
+	nft_unregister_chain_type(&nft_chain_filter_arp);
+}
+#else
+static inline void nft_chain_filter_arp_init(void) {}
+static inline void nft_chain_filter_arp_fini(void) {}
+#endif /* CONFIG_NF_TABLES_ARP */
+
+#ifdef CONFIG_NF_TABLES_IPV6
+static unsigned int nft_do_chain_ipv6(void *priv,
+				      struct sk_buff *skb,
+				      const struct nf_hook_state *state)
+{
+	struct nft_pktinfo pkt;
+
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_ipv6(&pkt, skb);
+
+	return nft_do_chain(&pkt, priv);
+}
+
+static const struct nft_chain_type nft_chain_filter_ipv6 = {
+	.name		= "filter",
+	.type		= NFT_CHAIN_T_DEFAULT,
+	.family		= NFPROTO_IPV6,
+	.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),
+	.hooks		= {
+		[NF_INET_LOCAL_IN]	= nft_do_chain_ipv6,
+		[NF_INET_LOCAL_OUT]	= nft_do_chain_ipv6,
+		[NF_INET_FORWARD]	= nft_do_chain_ipv6,
+		[NF_INET_PRE_ROUTING]	= nft_do_chain_ipv6,
+		[NF_INET_POST_ROUTING]	= nft_do_chain_ipv6,
+	},
+};
+
+static void nft_chain_filter_ipv6_init(void)
+{
+	nft_register_chain_type(&nft_chain_filter_ipv6);
+}
+
+static void nft_chain_filter_ipv6_fini(void)
+{
+	nft_unregister_chain_type(&nft_chain_filter_ipv6);
+}
+#else
+static inline void nft_chain_filter_ipv6_init(void) {}
+static inline void nft_chain_filter_ipv6_fini(void) {}
+#endif /* CONFIG_NF_TABLES_IPV6 */
+
+#ifdef CONFIG_NF_TABLES_INET
+static unsigned int nft_do_chain_inet(void *priv, struct sk_buff *skb,
+				      const struct nf_hook_state *state)
+{
+	struct nft_pktinfo pkt;
+
+	nft_set_pktinfo(&pkt, skb, state);
+
+	switch (state->pf) {
+	case NFPROTO_IPV4:
+		nft_set_pktinfo_ipv4(&pkt, skb);
+		break;
+	case NFPROTO_IPV6:
+		nft_set_pktinfo_ipv6(&pkt, skb);
+		break;
+	default:
+		break;
+	}
+
+	return nft_do_chain(&pkt, priv);
+}
+
+static const struct nft_chain_type nft_chain_filter_inet = {
+	.name		= "filter",
+	.type		= NFT_CHAIN_T_DEFAULT,
+	.family		= NFPROTO_INET,
+	.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),
+	.hooks		= {
+		[NF_INET_LOCAL_IN]	= nft_do_chain_inet,
+		[NF_INET_LOCAL_OUT]	= nft_do_chain_inet,
+		[NF_INET_FORWARD]	= nft_do_chain_inet,
+		[NF_INET_PRE_ROUTING]	= nft_do_chain_inet,
+		[NF_INET_POST_ROUTING]	= nft_do_chain_inet,
+        },
+};
+
+static void nft_chain_filter_inet_init(void)
+{
+	nft_register_chain_type(&nft_chain_filter_inet);
+}
+
+static void nft_chain_filter_inet_fini(void)
+{
+	nft_unregister_chain_type(&nft_chain_filter_inet);
+}
+#else
+static inline void nft_chain_filter_inet_init(void) {}
+static inline void nft_chain_filter_inet_fini(void) {}
+#endif /* CONFIG_NF_TABLES_IPV6 */
+
+#ifdef CONFIG_NF_TABLES_BRIDGE
+static unsigned int
+nft_do_chain_bridge(void *priv,
+		    struct sk_buff *skb,
+		    const struct nf_hook_state *state)
+{
+	struct nft_pktinfo pkt;
+
+	nft_set_pktinfo(&pkt, skb, state);
+
+	switch (eth_hdr(skb)->h_proto) {
+	case htons(ETH_P_IP):
+		nft_set_pktinfo_ipv4_validate(&pkt, skb);
+		break;
+	case htons(ETH_P_IPV6):
+		nft_set_pktinfo_ipv6_validate(&pkt, skb);
+		break;
+	default:
+		nft_set_pktinfo_unspec(&pkt, skb);
+		break;
+	}
+
+	return nft_do_chain(&pkt, priv);
+}
+
+static const struct nft_chain_type nft_chain_filter_bridge = {
+	.name		= "filter",
+	.type		= NFT_CHAIN_T_DEFAULT,
+	.family		= NFPROTO_BRIDGE,
+	.hook_mask	= (1 << NF_BR_PRE_ROUTING) |
+			  (1 << NF_BR_LOCAL_IN) |
+			  (1 << NF_BR_FORWARD) |
+			  (1 << NF_BR_LOCAL_OUT) |
+			  (1 << NF_BR_POST_ROUTING),
+	.hooks		= {
+		[NF_BR_PRE_ROUTING]	= nft_do_chain_bridge,
+		[NF_BR_LOCAL_IN]	= nft_do_chain_bridge,
+		[NF_BR_FORWARD]		= nft_do_chain_bridge,
+		[NF_BR_LOCAL_OUT]	= nft_do_chain_bridge,
+		[NF_BR_POST_ROUTING]	= nft_do_chain_bridge,
+	},
+};
+
+static void nft_chain_filter_bridge_init(void)
+{
+	nft_register_chain_type(&nft_chain_filter_bridge);
+}
+
+static void nft_chain_filter_bridge_fini(void)
+{
+	nft_unregister_chain_type(&nft_chain_filter_bridge);
+}
+#else
+static inline void nft_chain_filter_bridge_init(void) {}
+static inline void nft_chain_filter_bridge_fini(void) {}
+#endif /* CONFIG_NF_TABLES_BRIDGE */
+
+#ifdef CONFIG_NF_TABLES_NETDEV
+static unsigned int nft_do_chain_netdev(void *priv, struct sk_buff *skb,
+					const struct nf_hook_state *state)
+{
+	struct nft_pktinfo pkt;
+
+	nft_set_pktinfo(&pkt, skb, state);
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		nft_set_pktinfo_ipv4_validate(&pkt, skb);
+		break;
+	case htons(ETH_P_IPV6):
+		nft_set_pktinfo_ipv6_validate(&pkt, skb);
+		break;
+	default:
+		nft_set_pktinfo_unspec(&pkt, skb);
+		break;
+	}
+
+	return nft_do_chain(&pkt, priv);
+}
+
+static const struct nft_chain_type nft_chain_filter_netdev = {
+	.name		= "filter",
+	.type		= NFT_CHAIN_T_DEFAULT,
+	.family		= NFPROTO_NETDEV,
+	.hook_mask	= (1 << NF_NETDEV_INGRESS),
+	.hooks		= {
+		[NF_NETDEV_INGRESS]	= nft_do_chain_netdev,
+	},
+};
+
+static void nft_netdev_event(unsigned long event, struct net_device *dev,
+			     struct nft_ctx *ctx)
+{
+	struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
+
+	switch (event) {
+	case NETDEV_UNREGISTER:
+		if (strcmp(basechain->dev_name, dev->name) != 0)
+			return;
+
+		__nft_release_basechain(ctx);
+		break;
+	case NETDEV_CHANGENAME:
+		if (dev->ifindex != basechain->ops.dev->ifindex)
+			return;
+
+		strncpy(basechain->dev_name, dev->name, IFNAMSIZ);
+		break;
+	}
+}
+
+static int nf_tables_netdev_event(struct notifier_block *this,
+				  unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct nft_table *table;
+	struct nft_chain *chain, *nr;
+	struct nft_ctx ctx = {
+		.net	= dev_net(dev),
+	};
+
+	if (event != NETDEV_UNREGISTER &&
+	    event != NETDEV_CHANGENAME)
+		return NOTIFY_DONE;
+
+	nfnl_lock(NFNL_SUBSYS_NFTABLES);
+	list_for_each_entry(table, &ctx.net->nft.tables, list) {
+		if (table->family != NFPROTO_NETDEV)
+			continue;
+
+		ctx.family = table->family;
+		ctx.table = table;
+		list_for_each_entry_safe(chain, nr, &table->chains, list) {
+			if (!nft_is_base_chain(chain))
+				continue;
+
+			ctx.chain = chain;
+			nft_netdev_event(event, dev, &ctx);
+		}
+	}
+	nfnl_unlock(NFNL_SUBSYS_NFTABLES);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nf_tables_netdev_notifier = {
+	.notifier_call	= nf_tables_netdev_event,
+};
+
+static int nft_chain_filter_netdev_init(void)
+{
+	int err;
+
+	nft_register_chain_type(&nft_chain_filter_netdev);
+
+	err = register_netdevice_notifier(&nf_tables_netdev_notifier);
+	if (err)
+		goto err_register_netdevice_notifier;
+
+	return 0;
+
+err_register_netdevice_notifier:
+	nft_unregister_chain_type(&nft_chain_filter_netdev);
+
+	return err;
+}
+
+static void nft_chain_filter_netdev_fini(void)
+{
+	nft_unregister_chain_type(&nft_chain_filter_netdev);
+	unregister_netdevice_notifier(&nf_tables_netdev_notifier);
+}
+#else
+static inline int nft_chain_filter_netdev_init(void) { return 0; }
+static inline void nft_chain_filter_netdev_fini(void) {}
+#endif /* CONFIG_NF_TABLES_NETDEV */
+
+int __init nft_chain_filter_init(void)
+{
+	int err;
+
+	err = nft_chain_filter_netdev_init();
+	if (err < 0)
+		return err;
+
+	nft_chain_filter_ipv4_init();
+	nft_chain_filter_ipv6_init();
+	nft_chain_filter_arp_init();
+	nft_chain_filter_inet_init();
+	nft_chain_filter_bridge_init();
+
+	return 0;
+}
+
+void __exit nft_chain_filter_fini(void)
+{
+	nft_chain_filter_bridge_fini();
+	nft_chain_filter_inet_fini();
+	nft_chain_filter_arp_fini();
+	nft_chain_filter_ipv6_fini();
+	nft_chain_filter_ipv4_fini();
+	nft_chain_filter_netdev_fini();
+}