/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _X_TABLES_H
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#define _X_TABLES_H
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#include <linux/netdevice.h>
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#include <linux/static_key.h>
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#include <linux/netfilter.h>
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#include <uapi/linux/netfilter/x_tables.h>
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/* Test a struct->invflags and a boolean for inequality */
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#define NF_INVF(ptr, flag, boolean) \
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((boolean) ^ !!((ptr)->invflags & (flag)))
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/**
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* struct xt_action_param - parameters for matches/targets
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*
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* @match: the match extension
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* @target: the target extension
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* @matchinfo: per-match data
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* @targetinfo: per-target data
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* @state: pointer to hook state this packet came from
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* @fragoff: packet is a fragment, this is the data offset
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* @thoff: position of transport header relative to skb->data
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*
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* Fields written to by extensions:
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*
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* @hotdrop: drop packet if we had inspection problems
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*/
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struct xt_action_param {
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union {
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const struct xt_match *match;
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const struct xt_target *target;
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};
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union {
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const void *matchinfo, *targinfo;
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};
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const struct nf_hook_state *state;
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int fragoff;
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unsigned int thoff;
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bool hotdrop;
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};
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static inline struct net *xt_net(const struct xt_action_param *par)
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{
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return par->state->net;
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}
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static inline struct net_device *xt_in(const struct xt_action_param *par)
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{
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return par->state->in;
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}
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static inline const char *xt_inname(const struct xt_action_param *par)
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{
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return par->state->in->name;
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}
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static inline struct net_device *xt_out(const struct xt_action_param *par)
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{
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return par->state->out;
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}
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static inline const char *xt_outname(const struct xt_action_param *par)
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{
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return par->state->out->name;
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}
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static inline unsigned int xt_hooknum(const struct xt_action_param *par)
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{
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return par->state->hook;
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}
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static inline u_int8_t xt_family(const struct xt_action_param *par)
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{
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return par->state->pf;
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}
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/**
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* struct xt_mtchk_param - parameters for match extensions'
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* checkentry functions
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*
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* @net: network namespace through which the check was invoked
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* @table: table the rule is tried to be inserted into
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* @entryinfo: the family-specific rule data
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* (struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
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* @match: struct xt_match through which this function was invoked
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* @matchinfo: per-match data
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* @hook_mask: via which hooks the new rule is reachable
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* Other fields as above.
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*/
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struct xt_mtchk_param {
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struct net *net;
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const char *table;
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const void *entryinfo;
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const struct xt_match *match;
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void *matchinfo;
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unsigned int hook_mask;
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u_int8_t family;
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bool nft_compat;
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};
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/**
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* struct xt_mdtor_param - match destructor parameters
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* Fields as above.
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*/
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struct xt_mtdtor_param {
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struct net *net;
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const struct xt_match *match;
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void *matchinfo;
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u_int8_t family;
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};
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/**
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* struct xt_tgchk_param - parameters for target extensions'
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* checkentry functions
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*
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* @entryinfo: the family-specific rule data
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* (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
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*
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* Other fields see above.
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*/
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struct xt_tgchk_param {
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struct net *net;
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const char *table;
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const void *entryinfo;
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const struct xt_target *target;
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void *targinfo;
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unsigned int hook_mask;
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u_int8_t family;
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bool nft_compat;
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};
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/* Target destructor parameters */
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struct xt_tgdtor_param {
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struct net *net;
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const struct xt_target *target;
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void *targinfo;
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u_int8_t family;
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};
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struct xt_match {
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struct list_head list;
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const char name[XT_EXTENSION_MAXNAMELEN];
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u_int8_t revision;
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/* Return true or false: return FALSE and set *hotdrop = 1 to
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force immediate packet drop. */
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/* Arguments changed since 2.6.9, as this must now handle
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non-linear skb, using skb_header_pointer and
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skb_ip_make_writable. */
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bool (*match)(const struct sk_buff *skb,
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struct xt_action_param *);
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/* Called when user tries to insert an entry of this type. */
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int (*checkentry)(const struct xt_mtchk_param *);
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/* Called when entry of this type deleted. */
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void (*destroy)(const struct xt_mtdtor_param *);
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#ifdef CONFIG_COMPAT
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/* Called when userspace align differs from kernel space one */
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void (*compat_from_user)(void *dst, const void *src);
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int (*compat_to_user)(void __user *dst, const void *src);
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#endif
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/* Set this to THIS_MODULE if you are a module, otherwise NULL */
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struct module *me;
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const char *table;
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unsigned int matchsize;
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unsigned int usersize;
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#ifdef CONFIG_COMPAT
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unsigned int compatsize;
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#endif
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unsigned int hooks;
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unsigned short proto;
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unsigned short family;
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};
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/* Registration hooks for targets. */
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struct xt_target {
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struct list_head list;
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const char name[XT_EXTENSION_MAXNAMELEN];
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u_int8_t revision;
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/* Returns verdict. Argument order changed since 2.6.9, as this
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must now handle non-linear skbs, using skb_copy_bits and
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skb_ip_make_writable. */
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unsigned int (*target)(struct sk_buff *skb,
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const struct xt_action_param *);
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/* Called when user tries to insert an entry of this type:
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hook_mask is a bitmask of hooks from which it can be
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called. */
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/* Should return 0 on success or an error code otherwise (-Exxxx). */
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int (*checkentry)(const struct xt_tgchk_param *);
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/* Called when entry of this type deleted. */
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void (*destroy)(const struct xt_tgdtor_param *);
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#ifdef CONFIG_COMPAT
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/* Called when userspace align differs from kernel space one */
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void (*compat_from_user)(void *dst, const void *src);
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int (*compat_to_user)(void __user *dst, const void *src);
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#endif
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/* Set this to THIS_MODULE if you are a module, otherwise NULL */
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struct module *me;
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const char *table;
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unsigned int targetsize;
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unsigned int usersize;
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#ifdef CONFIG_COMPAT
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unsigned int compatsize;
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#endif
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unsigned int hooks;
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unsigned short proto;
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unsigned short family;
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};
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/* Furniture shopping... */
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struct xt_table {
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struct list_head list;
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/* What hooks you will enter on */
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unsigned int valid_hooks;
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/* Man behind the curtain... */
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struct xt_table_info *private;
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/* Set this to THIS_MODULE if you are a module, otherwise NULL */
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struct module *me;
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u_int8_t af; /* address/protocol family */
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int priority; /* hook order */
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/* called when table is needed in the given netns */
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int (*table_init)(struct net *net);
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/* A unique name... */
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const char name[XT_TABLE_MAXNAMELEN];
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};
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#include <linux/netfilter_ipv4.h>
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/* The table itself */
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struct xt_table_info {
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/* Size per table */
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unsigned int size;
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/* Number of entries: FIXME. --RR */
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unsigned int number;
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/* Initial number of entries. Needed for module usage count */
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unsigned int initial_entries;
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/* Entry points and underflows */
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unsigned int hook_entry[NF_INET_NUMHOOKS];
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unsigned int underflow[NF_INET_NUMHOOKS];
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/*
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* Number of user chains. Since tables cannot have loops, at most
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* @stacksize jumps (number of user chains) can possibly be made.
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*/
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unsigned int stacksize;
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void ***jumpstack;
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unsigned char entries[] __aligned(8);
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};
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int xt_register_target(struct xt_target *target);
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void xt_unregister_target(struct xt_target *target);
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int xt_register_targets(struct xt_target *target, unsigned int n);
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void xt_unregister_targets(struct xt_target *target, unsigned int n);
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int xt_register_match(struct xt_match *target);
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void xt_unregister_match(struct xt_match *target);
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int xt_register_matches(struct xt_match *match, unsigned int n);
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void xt_unregister_matches(struct xt_match *match, unsigned int n);
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int xt_check_entry_offsets(const void *base, const char *elems,
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unsigned int target_offset,
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unsigned int next_offset);
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int xt_check_table_hooks(const struct xt_table_info *info, unsigned int valid_hooks);
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unsigned int *xt_alloc_entry_offsets(unsigned int size);
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bool xt_find_jump_offset(const unsigned int *offsets,
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unsigned int target, unsigned int size);
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int xt_check_proc_name(const char *name, unsigned int size);
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int xt_check_match(struct xt_mtchk_param *, unsigned int size, u16 proto,
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bool inv_proto);
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int xt_check_target(struct xt_tgchk_param *, unsigned int size, u16 proto,
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bool inv_proto);
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int xt_match_to_user(const struct xt_entry_match *m,
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struct xt_entry_match __user *u);
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int xt_target_to_user(const struct xt_entry_target *t,
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struct xt_entry_target __user *u);
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int xt_data_to_user(void __user *dst, const void *src,
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int usersize, int size, int aligned_size);
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void *xt_copy_counters(sockptr_t arg, unsigned int len,
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struct xt_counters_info *info);
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struct xt_counters *xt_counters_alloc(unsigned int counters);
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struct xt_table *xt_register_table(struct net *net,
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const struct xt_table *table,
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struct xt_table_info *bootstrap,
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struct xt_table_info *newinfo);
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void *xt_unregister_table(struct xt_table *table);
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struct xt_table_info *xt_replace_table(struct xt_table *table,
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unsigned int num_counters,
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struct xt_table_info *newinfo,
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int *error);
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struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
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struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
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struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
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int xt_find_revision(u8 af, const char *name, u8 revision, int target,
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int *err);
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struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
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const char *name);
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struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af,
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const char *name);
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void xt_table_unlock(struct xt_table *t);
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int xt_proto_init(struct net *net, u_int8_t af);
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void xt_proto_fini(struct net *net, u_int8_t af);
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struct xt_table_info *xt_alloc_table_info(unsigned int size);
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void xt_free_table_info(struct xt_table_info *info);
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/**
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* xt_recseq - recursive seqcount for netfilter use
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*
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* Packet processing changes the seqcount only if no recursion happened
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* get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
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* because we use the normal seqcount convention :
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* Low order bit set to 1 if a writer is active.
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*/
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DECLARE_PER_CPU(seqcount_t, xt_recseq);
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/* xt_tee_enabled - true if x_tables needs to handle reentrancy
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*
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* Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
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*/
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extern struct static_key xt_tee_enabled;
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/**
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* xt_write_recseq_begin - start of a write section
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*
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* Begin packet processing : all readers must wait the end
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* 1) Must be called with preemption disabled
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* 2) softirqs must be disabled too (or we should use this_cpu_add())
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* Returns :
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* 1 if no recursion on this cpu
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* 0 if recursion detected
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*/
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static inline unsigned int xt_write_recseq_begin(void)
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{
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unsigned int addend;
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/*
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* Low order bit of sequence is set if we already
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* called xt_write_recseq_begin().
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*/
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addend = (__this_cpu_read(xt_recseq.sequence) + 1) & 1;
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/*
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* This is kind of a write_seqcount_begin(), but addend is 0 or 1
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* We dont check addend value to avoid a test and conditional jump,
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* since addend is most likely 1
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*/
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__this_cpu_add(xt_recseq.sequence, addend);
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smp_mb();
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return addend;
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}
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/**
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* xt_write_recseq_end - end of a write section
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* @addend: return value from previous xt_write_recseq_begin()
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*
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* End packet processing : all readers can proceed
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* 1) Must be called with preemption disabled
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* 2) softirqs must be disabled too (or we should use this_cpu_add())
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*/
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static inline void xt_write_recseq_end(unsigned int addend)
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{
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/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
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smp_wmb();
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__this_cpu_add(xt_recseq.sequence, addend);
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}
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/*
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* This helper is performance critical and must be inlined
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*/
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static inline unsigned long ifname_compare_aligned(const char *_a,
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const char *_b,
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const char *_mask)
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{
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const unsigned long *a = (const unsigned long *)_a;
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const unsigned long *b = (const unsigned long *)_b;
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const unsigned long *mask = (const unsigned long *)_mask;
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unsigned long ret;
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ret = (a[0] ^ b[0]) & mask[0];
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if (IFNAMSIZ > sizeof(unsigned long))
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ret |= (a[1] ^ b[1]) & mask[1];
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if (IFNAMSIZ > 2 * sizeof(unsigned long))
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ret |= (a[2] ^ b[2]) & mask[2];
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if (IFNAMSIZ > 3 * sizeof(unsigned long))
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ret |= (a[3] ^ b[3]) & mask[3];
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BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
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return ret;
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}
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struct xt_percpu_counter_alloc_state {
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unsigned int off;
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const char __percpu *mem;
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};
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bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
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struct xt_counters *counter);
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void xt_percpu_counter_free(struct xt_counters *cnt);
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static inline struct xt_counters *
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xt_get_this_cpu_counter(struct xt_counters *cnt)
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{
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if (nr_cpu_ids > 1)
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return this_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt);
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return cnt;
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}
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static inline struct xt_counters *
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xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu)
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{
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if (nr_cpu_ids > 1)
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return per_cpu_ptr((void __percpu *) (unsigned long) cnt->pcnt, cpu);
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return cnt;
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}
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struct nf_hook_ops *xt_hook_ops_alloc(const struct xt_table *, nf_hookfn *);
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#ifdef CONFIG_COMPAT
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#include <net/compat.h>
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struct compat_xt_entry_match {
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union {
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struct {
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u_int16_t match_size;
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char name[XT_FUNCTION_MAXNAMELEN - 1];
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u_int8_t revision;
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} user;
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struct {
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u_int16_t match_size;
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compat_uptr_t match;
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} kernel;
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u_int16_t match_size;
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} u;
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unsigned char data[];
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};
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struct compat_xt_entry_target {
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union {
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struct {
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u_int16_t target_size;
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char name[XT_FUNCTION_MAXNAMELEN - 1];
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u_int8_t revision;
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} user;
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struct {
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u_int16_t target_size;
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compat_uptr_t target;
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} kernel;
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u_int16_t target_size;
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} u;
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unsigned char data[];
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};
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/* FIXME: this works only on 32 bit tasks
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* need to change whole approach in order to calculate align as function of
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* current task alignment */
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struct compat_xt_counters {
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compat_u64 pcnt, bcnt; /* Packet and byte counters */
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};
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struct compat_xt_counters_info {
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char name[XT_TABLE_MAXNAMELEN];
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compat_uint_t num_counters;
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struct compat_xt_counters counters[];
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};
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struct _compat_xt_align {
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__u8 u8;
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__u16 u16;
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__u32 u32;
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compat_u64 u64;
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};
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#define COMPAT_XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _compat_xt_align))
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void xt_compat_lock(u_int8_t af);
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void xt_compat_unlock(u_int8_t af);
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int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
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void xt_compat_flush_offsets(u_int8_t af);
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int xt_compat_init_offsets(u8 af, unsigned int number);
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int xt_compat_calc_jump(u_int8_t af, unsigned int offset);
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int xt_compat_match_offset(const struct xt_match *match);
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void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
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unsigned int *size);
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int xt_compat_match_to_user(const struct xt_entry_match *m,
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void __user **dstptr, unsigned int *size);
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int xt_compat_target_offset(const struct xt_target *target);
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void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
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unsigned int *size);
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int xt_compat_target_to_user(const struct xt_entry_target *t,
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void __user **dstptr, unsigned int *size);
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int xt_compat_check_entry_offsets(const void *base, const char *elems,
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unsigned int target_offset,
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unsigned int next_offset);
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#endif /* CONFIG_COMPAT */
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#endif /* _X_TABLES_H */
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