/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _X_TABLES_H
#define _X_TABLES_H
#include <linux/netdevice.h>
#include <linux/static_key.h>
#include <linux/netfilter.h>
#include <uapi/linux/netfilter/x_tables.h>
/* Test a struct->invflags and a boolean for inequality */
#define NF_INVF(ptr, flag, boolean) \
((boolean) ^ !!((ptr)->invflags & (flag)))
/**
* struct xt_action_param - parameters for matches/targets
*
* @match: the match extension
* @target: the target extension
* @matchinfo: per-match data
* @targetinfo: per-target data
* @state: pointer to hook state this packet came from
* @fragoff: packet is a fragment, this is the data offset
* @thoff: position of transport header relative to skb->data
*
* Fields written to by extensions:
*
* @hotdrop: drop packet if we had inspection problems
*/
struct xt_action_param {
union {
const struct xt_match *match;
const struct xt_target *target;
};
union {
const void *matchinfo, *targinfo;
};
const struct nf_hook_state *state;
unsigned int thoff;
u16 fragoff;
bool hotdrop;
};
static inline struct net *xt_net(const struct xt_action_param *par)
{
return par->state->net;
}
static inline struct net_device *xt_in(const struct xt_action_param *par)
{
return par->state->in;
}
static inline const char *xt_inname(const struct xt_action_param *par)
{
return par->state->in->name;
}
static inline struct net_device *xt_out(const struct xt_action_param *par)
{
return par->state->out;
}
static inline const char *xt_outname(const struct xt_action_param *par)
{
return par->state->out->name;
}
static inline unsigned int xt_hooknum(const struct xt_action_param *par)
{
return par->state->hook;
}
static inline u_int8_t xt_family(const struct xt_action_param *par)
{
return par->state->pf;
}
/**
* 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;
bool nft_compat;
};
/**
* 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;
bool nft_compat;
};
/* 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_NETFILTER_XTABLES_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;
unsigned int usersize;
#ifdef CONFIG_NETFILTER_XTABLES_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_NETFILTER_XTABLES_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;
unsigned int usersize;
#ifdef CONFIG_NETFILTER_XTABLES_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;
/* hook ops that register the table with the netfilter core */
struct nf_hook_ops *ops;
/* 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;
void ***jumpstack;
unsigned char entries[] __aligned(8);
};
int xt_register_target(struct xt_target *target);
void xt_unregister_target(struct xt_target *target);
int xt_register_targets(struct xt_target *target, unsigned int n);
void xt_unregister_targets(struct xt_target *target, unsigned int n);
int xt_register_match(struct xt_match *target);
void xt_unregister_match(struct xt_match *target);
int xt_register_matches(struct xt_match *match, unsigned int n);
void xt_unregister_matches(struct xt_match *match, unsigned int n);
int xt_check_entry_offsets(const void *base, const char *elems,
unsigned int target_offset,
unsigned int next_offset);
int xt_check_table_hooks(const struct xt_table_info *info, unsigned int valid_hooks);
unsigned int *xt_alloc_entry_offsets(unsigned int size);
bool xt_find_jump_offset(const unsigned int *offsets,
unsigned int target, unsigned int size);
int xt_check_proc_name(const char *name, unsigned int size);
int xt_check_match(struct xt_mtchk_param *, unsigned int size, u16 proto,
bool inv_proto);
int xt_check_target(struct xt_tgchk_param *, unsigned int size, u16 proto,
bool inv_proto);
int xt_match_to_user(const struct xt_entry_match *m,
struct xt_entry_match __user *u);
int xt_target_to_user(const struct xt_entry_target *t,
struct xt_entry_target __user *u);
int xt_data_to_user(void __user *dst, const void *src,
int usersize, int size, int aligned_size);
void *xt_copy_counters(sockptr_t arg, unsigned int len,
struct xt_counters_info *info);
struct xt_counters *xt_counters_alloc(unsigned int counters);
struct xt_table *xt_register_table(struct net *net,
const struct xt_table *table,
struct xt_table_info *bootstrap,
struct xt_table_info *newinfo);
void *xt_unregister_table(struct xt_table *table);
struct xt_table_info *xt_replace_table(struct xt_table *table,
unsigned int num_counters,
struct xt_table_info *newinfo,
int *error);
struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
int xt_find_revision(u8 af, const char *name, u8 revision, int target,
int *err);
struct xt_table *xt_find_table(struct net *net, u8 af, const char *name);
struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
const char *name);
struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af,
const char *name);
void xt_table_unlock(struct xt_table *t);
int xt_proto_init(struct net *net, u_int8_t af);
void xt_proto_fini(struct net *net, u_int8_t af);
struct xt_table_info *xt_alloc_table_info(unsigned int size);
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_tee_enabled - true if x_tables needs to handle reentrancy
*
* Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
*/
extern struct static_key xt_tee_enabled;
/**
* 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_mb();
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;
}
struct xt_percpu_counter_alloc_state {
unsigned int off;
const char __percpu *mem;
};
bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
struct xt_counters *counter);
void xt_percpu_counter_free(struct xt_counters *cnt);
static inline struct xt_counters *
xt_get_this_cpu_counter(struct xt_counters *cnt)
{
if (nr_cpu_ids > 1)
return this_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt);
return cnt;
}
static inline struct xt_counters *
xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu)
{
if (nr_cpu_ids > 1)
return per_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt, cpu);
return cnt;
}
struct nf_hook_ops *xt_hook_ops_alloc(const struct xt_table *, nf_hookfn *);
int xt_register_template(const struct xt_table *t, int(*table_init)(struct net *net));
void xt_unregister_template(const struct xt_table *t);
#ifdef CONFIG_NETFILTER_XTABLES_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[];
};
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[];
};
/* 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[];
};
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))
void xt_compat_lock(u_int8_t af);
void xt_compat_unlock(u_int8_t af);
int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
void xt_compat_flush_offsets(u_int8_t af);
int xt_compat_init_offsets(u8 af, unsigned int number);
int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
int xt_compat_match_offset(const struct xt_match *match);
void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
unsigned int *size);
int xt_compat_match_to_user(const struct xt_entry_match *m,
void __user **dstptr, unsigned int *size);
int xt_compat_target_offset(const struct xt_target *target);
void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
unsigned int *size);
int xt_compat_target_to_user(const struct xt_entry_target *t,
void __user **dstptr, unsigned int *size);
int xt_compat_check_entry_offsets(const void *base, const char *elems,
unsigned int target_offset,
unsigned int next_offset);
#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
#endif /* _X_TABLES_H */
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