use nf_tables and nf_tables compatibility interface

This patch adds the following utilities:

* xtables
* xtables-restore
* xtables-save
* xtables-config

They all use Patrick's nf_tables infrastructure plus my compatibility
layer.

xtables, xtables-restore and xtables-save are syntax compatible with
ip[6]tables, ip[6]tables-restore and ip[6]tables-save.

Semantics aims to be similar, still the main exception is that there
is no commit operation. Thus, we incrementally add/delete rules without
entire table locking.

The following options are also not yet implemented:

-Z (this requires adding expr->ops->reset(...) so nft_counters can reset
    internal state of expressions while dumping it)

-R and -E (this requires adding this feature to nf_tables)

-f (can be implemented with expressions: payload 6 (2-bytes) + bitwise a&b^!b + cmp neq 0)

-IPv6 support.

But those are a matter of time to get them done.

A new utility, xtables-config, is available to register tables and
chains. By default there is a configuration file that adds backward
compatible tables and chains under iptables/etc/xtables.conf. You have
to call this utility first to register tables and chains.

However, it would be possible to automagically register tables and
chains while using xtables and xtables-restore to get similar operation
than with iptables.

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

1 files changed, 62 insertions, 0 deletions

diff --git a/iptables/nft.h b/iptables/nft.h
new file mode 100644
index 00000000..f5a9efb8
--- /dev/null
+++ b/iptables/nft.h
@@ -0,0 +1,62 @@
+#ifndef _NFT_H_
+#define _NFT_H_
+
+#include "xshared.h"
+
+struct nft_handle {
+	struct mnl_socket	*nl;
+	uint32_t		portid;
+	uint32_t		seq;
+};
+
+int nft_init(struct nft_handle *h);
+void nft_fini(struct nft_handle *h);
+
+/*
+ * Operations with tables.
+ */
+struct nft_table;
+
+int nft_table_add(struct nft_handle *h, const struct nft_table *t);
+int nft_for_each_table(struct nft_handle *h, int (*func)(struct nft_handle *h, const char *tablename, bool counters), bool counters);
+bool nft_table_find(struct nft_handle *h, const char *tablename);
+
+/*
+ * Operations with chains.
+ */
+struct nft_chain;
+
+int nft_chain_add(struct nft_handle *h, const struct nft_chain *c);
+int nft_chain_set(struct nft_handle *h, const char *table, const char *chain, const char *policy, const struct xt_counters *counters);
+struct nft_chain_list *nft_chain_dump(struct nft_handle *h);
+int nft_chain_save(struct nft_handle *h, struct nft_chain_list *list, const char *table);
+int nft_chain_user_add(struct nft_handle *h, const char *chain, const char *table);
+int nft_chain_user_del(struct nft_handle *h, const char *chain, const char *table);
+int nft_chain_user_rename(struct nft_handle *h, const char *chain, const char *table, const char *newname);
+
+/*
+ * Operations with rule-set.
+ */
+struct nft_rule;
+
+int nft_rule_add(struct nft_handle *h, const char *chain, const char *table, struct iptables_command_state *cmd, bool append, bool verbose);
+int nft_rule_check(struct nft_handle *h, const char *chain, const char *table, struct iptables_command_state *cmd, bool verbose);
+int nft_rule_delete(struct nft_handle *h, const char *chain, const char *table, struct iptables_command_state *cmd, bool verbose);
+int nft_rule_delete_num(struct nft_handle *h, const char *chain, const char *table, int rulenum, bool verbose);
+int nft_rule_replace(struct nft_handle *h, const char *chain, const char *table, struct iptables_command_state *cmd, int rulenum, bool verbose);
+int nft_rule_list(struct nft_handle *h, const char *chain, const char *table, int rulenum, unsigned int format);
+int nft_rule_list_save(struct nft_handle *h, const char *chain, const char *table, int rulenum, int counters);
+int nft_rule_save(struct nft_handle *h, const char *table, bool counters);
+int nft_rule_flush(struct nft_handle *h, const char *chain, const char *table);
+
+/*
+ * revision compatibility.
+ */
+int nft_compatible_revision(const char *name, uint8_t rev, int opt);
+
+/*
+ * Error reporting.
+ */
+const char *nft_strerror(int err);
+
+#endif