[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables
This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables. In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.
o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
are now implemented as xt_FOOBAR.c files and provide module aliases
to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
around the xt_FOOBAR.h headers
Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
new file mode 100644
index 0000000..472f048
--- /dev/null
+++ b/include/linux/netfilter/x_tables.h
@@ -0,0 +1,224 @@
+#ifndef _X_TABLES_H
+#define _X_TABLES_H
+
+#define XT_FUNCTION_MAXNAMELEN 30
+#define XT_TABLE_MAXNAMELEN 32
+
+/* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
+ * kernel supports, if >= revision. */
+struct xt_get_revision
+{
+ char name[XT_FUNCTION_MAXNAMELEN-1];
+
+ u_int8_t revision;
+};
+
+/* CONTINUE verdict for targets */
+#define XT_CONTINUE 0xFFFFFFFF
+
+/* For standard target */
+#define XT_RETURN (-NF_REPEAT - 1)
+
+#define XT_ALIGN(s) (((s) + (__alignof__(void *)-1)) & ~(__alignof__(void *)-1))
+
+/* Standard return verdict, or do jump. */
+#define XT_STANDARD_TARGET ""
+/* Error verdict. */
+#define XT_ERROR_TARGET "ERROR"
+
+/*
+ * New IP firewall options for [gs]etsockopt at the RAW IP level.
+ * Unlike BSD Linux inherits IP options so you don't have to use a raw
+ * socket for this. Instead we check rights in the calls. */
+#define XT_BASE_CTL 64 /* base for firewall socket options */
+
+#define XT_SO_SET_REPLACE (XT_BASE_CTL)
+#define XT_SO_SET_ADD_COUNTERS (XT_BASE_CTL + 1)
+#define XT_SO_SET_MAX XT_SO_SET_ADD_COUNTERS
+
+#define XT_SO_GET_INFO (XT_BASE_CTL)
+#define XT_SO_GET_ENTRIES (XT_BASE_CTL + 1)
+#define XT_SO_GET_REVISION_MATCH (XT_BASE_CTL + 2)
+#define XT_SO_GET_REVISION_TARGET (XT_BASE_CTL + 3)
+#define XT_SO_GET_MAX XT_SO_GET_REVISION_TARGET
+
+#define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
+#define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
+
+struct xt_counters
+{
+ u_int64_t pcnt, bcnt; /* Packet and byte counters */
+};
+
+/* The argument to IPT_SO_ADD_COUNTERS. */
+struct xt_counters_info
+{
+ /* Which table. */
+ char name[XT_TABLE_MAXNAMELEN];
+
+ unsigned int num_counters;
+
+ /* The counters (actually `number' of these). */
+ struct xt_counters counters[0];
+};
+
+#define XT_INV_PROTO 0x40 /* Invert the sense of PROTO. */
+
+#ifdef __KERNEL__
+
+#include <linux/netdevice.h>
+
+#define ASSERT_READ_LOCK(x)
+#define ASSERT_WRITE_LOCK(x)
+#include <linux/netfilter_ipv4/listhelp.h>
+
+struct xt_match
+{
+ struct list_head list;
+
+ const char name[XT_FUNCTION_MAXNAMELEN-1];
+
+ u_int8_t revision;
+
+ /* Return true or false: return FALSE and set *hotdrop = 1 to
+ force immediate packet drop. */
+ /* Arguments changed since 2.6.9, as this must now handle
+ non-linear skb, using skb_header_pointer and
+ skb_ip_make_writable. */
+ int (*match)(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop);
+
+ /* Called when user tries to insert an entry of this type. */
+ /* Should return true or false. */
+ int (*checkentry)(const char *tablename,
+ const void *ip,
+ void *matchinfo,
+ unsigned int matchinfosize,
+ unsigned int hook_mask);
+
+ /* Called when entry of this type deleted. */
+ void (*destroy)(void *matchinfo, unsigned int matchinfosize);
+
+ /* Set this to THIS_MODULE if you are a module, otherwise NULL */
+ struct module *me;
+};
+
+/* Registration hooks for targets. */
+struct xt_target
+{
+ struct list_head list;
+
+ const char name[XT_FUNCTION_MAXNAMELEN-1];
+
+ u_int8_t revision;
+
+ /* Returns verdict. Argument order changed since 2.6.9, as this
+ must now handle non-linear skbs, using skb_copy_bits and
+ skb_ip_make_writable. */
+ unsigned int (*target)(struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const void *targinfo,
+ void *userdata);
+
+ /* Called when user tries to insert an entry of this type:
+ hook_mask is a bitmask of hooks from which it can be
+ called. */
+ /* Should return true or false. */
+ int (*checkentry)(const char *tablename,
+ const void *entry,
+ void *targinfo,
+ unsigned int targinfosize,
+ unsigned int hook_mask);
+
+ /* Called when entry of this type deleted. */
+ void (*destroy)(void *targinfo, unsigned int targinfosize);
+
+ /* Set this to THIS_MODULE if you are a module, otherwise NULL */
+ struct module *me;
+};
+
+/* Furniture shopping... */
+struct xt_table
+{
+ struct list_head list;
+
+ /* A unique name... */
+ char name[XT_TABLE_MAXNAMELEN];
+
+ /* What hooks you will enter on */
+ unsigned int valid_hooks;
+
+ /* Lock for the curtain */
+ rwlock_t lock;
+
+ /* Man behind the curtain... */
+ //struct ip6t_table_info *private;
+ void *private;
+
+ /* Set this to THIS_MODULE if you are a module, otherwise NULL */
+ struct module *me;
+
+ int af; /* address/protocol family */
+};
+
+#include <linux/netfilter_ipv4.h>
+
+/* The table itself */
+struct xt_table_info
+{
+ /* Size per table */
+ unsigned int size;
+ /* Number of entries: FIXME. --RR */
+ unsigned int number;
+ /* Initial number of entries. Needed for module usage count */
+ unsigned int initial_entries;
+
+ /* Entry points and underflows */
+ unsigned int hook_entry[NF_IP_NUMHOOKS];
+ unsigned int underflow[NF_IP_NUMHOOKS];
+
+ /* ipt_entry tables: one per CPU */
+ char *entries[NR_CPUS];
+};
+
+extern int xt_register_target(int af, struct xt_target *target);
+extern void xt_unregister_target(int af, struct xt_target *target);
+extern int xt_register_match(int af, struct xt_match *target);
+extern void xt_unregister_match(int af, struct xt_match *target);
+
+extern int xt_register_table(struct xt_table *table,
+ struct xt_table_info *bootstrap,
+ struct xt_table_info *newinfo);
+extern void *xt_unregister_table(struct xt_table *table);
+
+extern struct xt_table_info *xt_replace_table(struct xt_table *table,
+ unsigned int num_counters,
+ struct xt_table_info *newinfo,
+ int *error);
+
+extern struct xt_match *xt_find_match(int af, const char *name, u8 revision);
+extern struct xt_target *xt_find_target(int af, const char *name, u8 revision);
+extern struct xt_target *xt_request_find_target(int af, const char *name,
+ u8 revision);
+extern int xt_find_revision(int af, const char *name, u8 revision, int target,
+ int *err);
+
+extern struct xt_table *xt_find_table_lock(int af, const char *name);
+extern void xt_table_unlock(struct xt_table *t);
+
+extern int xt_proto_init(int af);
+extern void xt_proto_fini(int af);
+
+extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
+extern void xt_free_table_info(struct xt_table_info *info);
+
+#endif /* __KERNEL__ */
+
+#endif /* _X_TABLES_H */