#ifndef _X_TABLES_H
#define _X_TABLES_H
#include <linux/netdevice.h>
#include <uapi/linux/netfilter/x_tables.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);
/**
* xt_recseq - recursive seqcount for netfilter use
*
* Packet processing changes the seqcount only if no recursion happened
* get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
* because we use the normal seqcount convention :
* Low order bit set to 1 if a writer is active.
*/
DECLARE_PER_CPU(seqcount_t, xt_recseq);
/**
* xt_write_recseq_begin - start of a write section
*
* Begin packet processing : all readers must wait the end
* 1) Must be called with preemption disabled
* 2) softirqs must be disabled too (or we should use this_cpu_add())
* Returns :
* 1 if no recursion on this cpu
* 0 if recursion detected
*/
static inline unsigned int xt_write_recseq_begin(void)
{
unsigned int addend;
/*
* Low order bit of sequence is set if we already
* called xt_write_recseq_begin().
*/
addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1;
/*
* This is kind of a write_seqcount_begin(), but addend is 0 or 1
* We dont check addend value to avoid a test and conditional jump,
* since addend is most likely 1
*/
__this_cpu_add(xt_recseq.sequence, addend);
smp_wmb();
return addend;
}
/**
* xt_write_recseq_end - end of a write section
* @addend: return value from previous xt_write_recseq_begin()
*
* End packet processing : all readers can proceed
* 1) Must be called with preemption disabled
* 2) softirqs must be disabled too (or we should use this_cpu_add())
*/
static inline void xt_write_recseq_end(unsigned int addend)
{
/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
smp_wmb();
__this_cpu_add(xt_recseq.sequence, addend);
}
/*
* 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 /* _X_TABLES_H */