#ifndef _X_TABLES_H
#define _X_TABLES_H
#include <linux/kernel.h>
#include <linux/types.h>
#define XT_FUNCTION_MAXNAMELEN 30
#define XT_EXTENSION_MAXNAMELEN 29
#define XT_TABLE_MAXNAMELEN 32
struct xt_entry_match {
union {
struct {
__u16 match_size;
/* Used by userspace */
char name[XT_EXTENSION_MAXNAMELEN];
__u8 revision;
} user;
struct {
__u16 match_size;
/* Used inside the kernel */
struct xt_match *match;
} kernel;
/* Total length */
__u16 match_size;
} u;
unsigned char data[0];
};
struct xt_entry_target {
union {
struct {
__u16 target_size;
/* Used by userspace */
char name[XT_EXTENSION_MAXNAMELEN];
__u8 revision;
} user;
struct {
__u16 target_size;
/* Used inside the kernel */
struct xt_target *target;
} kernel;
/* Total length */
__u16 target_size;
} u;
unsigned char data[0];
};
#define XT_TARGET_INIT(__name, __size) \
{ \
.target.u.user = { \
.target_size = XT_ALIGN(__size), \
.name = __name, \
}, \
}
struct xt_standard_target {
struct xt_entry_target target;
int verdict;
};
struct xt_error_target {
struct xt_entry_target target;
char errorname[XT_FUNCTION_MAXNAMELEN];
};
/* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
* kernel supports, if >= revision. */
struct xt_get_revision {
char name[XT_EXTENSION_MAXNAMELEN];
__u8 revision;
};
/* CONTINUE verdict for targets */
#define XT_CONTINUE 0xFFFFFFFF
/* For standard target */
#define XT_RETURN (-NF_REPEAT - 1)
/* this is a dummy structure to find out the alignment requirement for a struct
* containing all the fundamental data types that are used in ipt_entry,
* ip6t_entry and arpt_entry. This sucks, and it is a hack. It will be my
* personal pleasure to remove it -HW
*/
struct _xt_align {
__u8 u8;
__u16 u16;
__u32 u32;
__u64 u64;
};
#define XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _xt_align))
/* Standard return verdict, or do jump. */
#define XT_STANDARD_TARGET ""
/* Error verdict. */
#define XT_ERROR_TARGET "ERROR"
#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 {
__u64 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. */
#ifndef __KERNEL__
/* fn returns 0 to continue iteration */
#define XT_MATCH_ITERATE(type, e, fn, args...) \
({ \
unsigned int __i; \
int __ret = 0; \
struct xt_entry_match *__m; \
\
for (__i = sizeof(type); \
__i < (e)->target_offset; \
__i += __m->u.match_size) { \
__m = (void *)e + __i; \
\
__ret = fn(__m , ## args); \
if (__ret != 0) \
break; \
} \
__ret; \
})
/* fn returns 0 to continue iteration */
#define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
({ \
unsigned int __i, __n; \
int __ret = 0; \
type *__entry; \
\
for (__i = 0, __n = 0; __i < (size); \
__i += __entry->next_offset, __n++) { \
__entry = (void *)(entries) + __i; \
if (__n < n) \
continue; \
\
__ret = fn(__entry , ## args); \
if (__ret != 0) \
break; \
} \
__ret; \
})
/* fn returns 0 to continue iteration */
#define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
#endif /* !__KERNEL__ */
/* pos is normally a struct ipt_entry/ip6t_entry/etc. */
#define xt_entry_foreach(pos, ehead, esize) \
for ((pos) = (typeof(pos))(ehead); \
(pos) < (typeof(pos))((char *)(ehead) + (esize)); \
(pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
/* can only be xt_entry_match, so no use of typeof here */
#define xt_ematch_foreach(pos, entry) \
for ((pos) = (struct xt_entry_match *)entry->elems; \
(pos) < (struct xt_entry_match *)((char *)(entry) + \
(entry)->target_offset); \
(pos) = (struct xt_entry_match *)((char *)(pos) + \
(pos)->u.match_size))
#ifdef __KERNEL__
#include <linux/netdevice.h>
/**
* struct xt_action_param - parameters for matches/targets
*
* @match: the match extension
* @target: the target extension
* @matchinfo: per-match data
* @targetinfo: per-target data
* @in: input netdevice
* @out: output netdevice
* @fragoff: packet is a fragment, this is the data offset
* @thoff: position of transport header relative to skb->data
* @hook: hook number given packet came from
* @family: Actual NFPROTO_* through which the function is invoked
* (helpful when match->family == NFPROTO_UNSPEC)
*
* Fields written to by extensions:
*
* @hotdrop: drop packet if we had inspection problems
* Network namespace obtainable using dev_net(in/out)
*/
struct xt_action_param {
union {
const struct xt_match *match;
const struct xt_target *target;
};
union {
const void *matchinfo, *targinfo;
};
const struct net_device *in, *out;
int fragoff;
unsigned int thoff;
unsigned int hooknum;
u_int8_t family;
bool hotdrop;
};
/**
* struct xt_mtchk_param - parameters for match extensions'
* checkentry functions
*
* @net: network namespace through which the check was invoked
* @table: table the rule is tried to be inserted into
* @entryinfo: the family-specific rule data
* (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
* @match: struct xt_match through which this function was invoked
* @matchinfo: per-match data
* @hook_mask: via which hooks the new rule is reachable
* Other fields as above.
*/
struct xt_mtchk_param {
struct net *net;
const char *table;
const void *entryinfo;
const struct xt_match *match;
void *matchinfo;
unsigned int hook_mask;
u_int8_t family;
};
/**
* struct xt_mdtor_param - match destructor parameters
* Fields as above.
*/
struct xt_mtdtor_param {
struct net *net;
const struct xt_match *match;
void *matchinfo;
u_int8_t family;
};
/**
* struct xt_tgchk_param - parameters for target extensions'
* checkentry functions
*
* @entryinfo: the family-specific rule data
* (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
*
* Other fields see above.
*/
struct xt_tgchk_param {
struct net *net;
const char *table;
const void *entryinfo;
const struct xt_target *target;
void *targinfo;
unsigned int hook_mask;
u_int8_t family;
};
/* Target destructor parameters */
struct xt_tgdtor_param {
struct net *net;
const struct xt_target *target;
void *targinfo;
u_int8_t family;
};
struct xt_match {
struct list_head list;
const char name[XT_EXTENSION_MAXNAMELEN];
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. */
bool (*match)(const struct sk_buff *skb,
struct xt_action_param *);
/* Called when user tries to insert an entry of this type. */
int (*checkentry)(const struct xt_mtchk_param *);
/* Called when entry of this type deleted. */
void (*destroy)(const struct xt_mtdtor_param *);
#ifdef CONFIG_COMPAT
/* Called when userspace align differs from kernel space one */
void (*compat_from_user)(void *dst, const void *src);
int (*compat_to_user)(void __user *dst, const void *src);
#endif
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
const char *table;
unsigned int matchsize;
#ifdef CONFIG_COMPAT
unsigned int compatsize;
#endif
unsigned int hooks;
unsigned short proto;
unsigned short family;
};
/* Registration hooks for targets. */
struct xt_target {
struct list_head list;
const char name[XT_EXTENSION_MAXNAMELEN];
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 *skb,
const struct xt_action_param *);
/* 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 0 on success or an error code otherwise (-Exxxx). */
int (*checkentry)(const struct xt_tgchk_param *);
/* Called when entry of this type deleted. */
void (*destroy)(const struct xt_tgdtor_param *);
#ifdef CONFIG_COMPAT
/* Called when userspace align differs from kernel space one */
void (*compat_from_user)(void *dst, const void *src);
int (*compat_to_user)(void __user *dst, const void *src);
#endif
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
const char *table;
unsigned int targetsize;
#ifdef CONFIG_COMPAT
unsigned int compatsize;
#endif
unsigned int hooks;
unsigned short proto;
unsigned short family;
};
/* Furniture shopping... */
struct xt_table {
struct list_head list;
/* What hooks you will enter on */
unsigned int valid_hooks;
/* Man behind the curtain... */
struct xt_table_info *private;
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
u_int8_t af; /* address/protocol family */
int priority; /* hook order */
/* A unique name... */
const char name[XT_TABLE_MAXNAMELEN];
};
#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_INET_NUMHOOKS];
unsigned int underflow[NF_INET_NUMHOOKS];
/*
* Number of user chains. Since tables cannot have loops, at most
* @stacksize jumps (number of user chains) can possibly be made.
*/
unsigned int stacksize;
unsigned int __percpu *stackptr;
void ***jumpstack;
/* ipt_entry tables: one per CPU */
/* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
void *entries[1];
};
#define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
+ nr_cpu_ids * sizeof(char *))
extern int xt_register_target(struct xt_target *target);
extern void xt_unregister_target(struct xt_target *target);
extern int xt_register_targets(struct xt_target *target, unsigned int n);
extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
extern int xt_register_match(struct xt_match *target);
extern void xt_unregister_match(struct xt_match *target);
extern int xt_register_matches(struct xt_match *match, unsigned int n);
extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
extern int xt_check_match(struct xt_mtchk_param *,
unsigned int size, u_int8_t proto, bool inv_proto);
extern int xt_check_target(struct xt_tgchk_param *,
unsigned int size, u_int8_t proto, bool inv_proto);
extern struct xt_table *xt_register_table(struct net *net,
const 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(u8 af, const char *name, u8 revision);
extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
extern struct xt_match *xt_request_find_match(u8 af, const char *name,
u8 revision);
extern struct xt_target *xt_request_find_target(u8 af, const char *name,
u8 revision);
extern int xt_find_revision(u8 af, const char *name, u8 revision,
int target, int *err);
extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
const char *name);
extern void xt_table_unlock(struct xt_table *t);
extern int xt_proto_init(struct net *net, u_int8_t af);
extern void xt_proto_fini(struct net *net, u_int8_t af);
extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
extern void xt_free_table_info(struct xt_table_info *info);
/*
* Per-CPU spinlock associated with per-cpu table entries, and
* with a counter for the "reading" side that allows a recursive
* reader to avoid taking the lock and deadlocking.
*
* "reading" is used by ip/arp/ip6 tables rule processing which runs per-cpu.
* It needs to ensure that the rules are not being changed while the packet
* is being processed. In some cases, the read lock will be acquired
* twice on the same CPU; this is okay because of the count.
*
* "writing" is used when reading counters.
* During replace any readers that are using the old tables have to complete
* before freeing the old table. This is handled by the write locking
* necessary for reading the counters.
*/
struct xt_info_lock {
seqlock_t lock;
unsigned char readers;
};
DECLARE_PER_CPU(struct xt_info_lock, xt_info_locks);
/*
* Note: we need to ensure that preemption is disabled before acquiring
* the per-cpu-variable, so we do it as a two step process rather than
* using "spin_lock_bh()".
*
* We _also_ need to disable bottom half processing before updating our
* nesting count, to make sure that the only kind of re-entrancy is this
* code being called by itself: since the count+lock is not an atomic
* operation, we can allow no races.
*
* _Only_ that special combination of being per-cpu and never getting
* re-entered asynchronously means that the count is safe.
*/
static inline void xt_info_rdlock_bh(void)
{
struct xt_info_lock *lock;
local_bh_disable();
lock = &__get_cpu_var(xt_info_locks);
if (likely(!lock->readers++))
write_seqlock(&lock->lock);
}
static inline void xt_info_rdunlock_bh(void)
{
struct xt_info_lock *lock = &__get_cpu_var(xt_info_locks);
if (likely(!--lock->readers))
write_sequnlock(&lock->lock);
local_bh_enable();
}
/*
* The "writer" side needs to get exclusive access to the lock,
* regardless of readers. This must be called with bottom half
* processing (and thus also preemption) disabled.
*/
static inline void xt_info_wrlock(unsigned int cpu)
{
write_seqlock(&per_cpu(xt_info_locks, cpu).lock);
}
static inline void xt_info_wrunlock(unsigned int cpu)
{
write_sequnlock(&per_cpu(xt_info_locks, cpu).lock);
}
/*
* This helper is performance critical and must be inlined
*/
static inline unsigned long ifname_compare_aligned(const char *_a,
const char *_b,
const char *_mask)
{
const unsigned long *a = (const unsigned long *)_a;
const unsigned long *b = (const unsigned long *)_b;
const unsigned long *mask = (const unsigned long *)_mask;
unsigned long ret;
ret = (a[0] ^ b[0]) & mask[0];
if (IFNAMSIZ > sizeof(unsigned long))
ret |= (a[1] ^ b[1]) & mask[1];
if (IFNAMSIZ > 2 * sizeof(unsigned long))
ret |= (a[2] ^ b[2]) & mask[2];
if (IFNAMSIZ > 3 * sizeof(unsigned long))
ret |= (a[3] ^ b[3]) & mask[3];
BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
return ret;
}
extern struct nf_hook_ops *xt_hook_link(const struct xt_table *, nf_hookfn *);
extern void xt_hook_unlink(const struct xt_table *, struct nf_hook_ops *);
#ifdef CONFIG_COMPAT
#include <net/compat.h>
struct compat_xt_entry_match {
union {
struct {
u_int16_t match_size;
char name[XT_FUNCTION_MAXNAMELEN - 1];
u_int8_t revision;
} user;
struct {
u_int16_t match_size;
compat_uptr_t match;
} kernel;
u_int16_t match_size;
} u;
unsigned char data[0];
};
struct compat_xt_entry_target {
union {
struct {
u_int16_t target_size;
char name[XT_FUNCTION_MAXNAMELEN - 1];
u_int8_t revision;
} user;
struct {
u_int16_t target_size;
compat_uptr_t target;
} kernel;
u_int16_t target_size;
} u;
unsigned char data[0];
};
/* FIXME: this works only on 32 bit tasks
* need to change whole approach in order to calculate align as function of
* current task alignment */
struct compat_xt_counters {
compat_u64 pcnt, bcnt; /* Packet and byte counters */
};
struct compat_xt_counters_info {
char name[XT_TABLE_MAXNAMELEN];
compat_uint_t num_counters;
struct compat_xt_counters counters[0];
};
struct _compat_xt_align {
__u8 u8;
__u16 u16;
__u32 u32;
compat_u64 u64;
};
#define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
extern void xt_compat_lock(u_int8_t af);
extern void xt_compat_unlock(u_int8_t af);
extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
extern void xt_compat_flush_offsets(u_int8_t af);
extern void xt_compat_init_offsets(u_int8_t af, unsigned int number);
extern int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
extern int xt_compat_match_offset(const struct xt_match *match);
extern int xt_compat_match_from_user(struct xt_entry_match *m,
void **dstptr, unsigned int *size);
extern int xt_compat_match_to_user(const struct xt_entry_match *m,
void __user **dstptr, unsigned int *size);
extern int xt_compat_target_offset(const struct xt_target *target);
extern void xt_compat_target_from_user(struct xt_entry_target *t,
void **dstptr, unsigned int *size);
extern int xt_compat_target_to_user(const struct xt_entry_target *t,
void __user **dstptr, unsigned int *size);
#endif /* CONFIG_COMPAT */
#endif /* __KERNEL__ */
#endif /* _X_TABLES_H */