LXR linux/include/linux/netfilter

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 *  ebtables
   4 *
   5 *      Authors:
   6 *      Bart De Schuymer                <bdschuym@pandora.be>
   7 *
   8 *  ebtables.c,v 2.0, April, 2002
   9 *
  10 *  This code is strongly inspired by the iptables code which is
  11 *  Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
  12 */
  13#ifndef __LINUX_BRIDGE_EFF_H
  14#define __LINUX_BRIDGE_EFF_H
  15
  16#include <linux/if.h>
  17#include <linux/if_ether.h>
  18#include <uapi/linux/netfilter_bridge/ebtables.h>
  19
  20/* return values for match() functions */
  21#define EBT_MATCH 0
  22#define EBT_NOMATCH 1
  23
  24struct ebt_match {
  25        struct list_head list;
  26        const char name[EBT_FUNCTION_MAXNAMELEN];
  27        bool (*match)(const struct sk_buff *skb, const struct net_device *in,
  28                const struct net_device *out, const struct xt_match *match,
  29                const void *matchinfo, int offset, unsigned int protoff,
  30                bool *hotdrop);
  31        bool (*checkentry)(const char *table, const void *entry,
  32                const struct xt_match *match, void *matchinfo,
  33                unsigned int hook_mask);
  34        void (*destroy)(const struct xt_match *match, void *matchinfo);
  35        unsigned int matchsize;
  36        u_int8_t revision;
  37        u_int8_t family;
  38        struct module *me;
  39};
  40
  41struct ebt_watcher {
  42        struct list_head list;
  43        const char name[EBT_FUNCTION_MAXNAMELEN];
  44        unsigned int (*target)(struct sk_buff *skb,
  45                const struct net_device *in, const struct net_device *out,
  46                unsigned int hook_num, const struct xt_target *target,
  47                const void *targinfo);
  48        bool (*checkentry)(const char *table, const void *entry,
  49                const struct xt_target *target, void *targinfo,
  50                unsigned int hook_mask);
  51        void (*destroy)(const struct xt_target *target, void *targinfo);
  52        unsigned int targetsize;
  53        u_int8_t revision;
  54        u_int8_t family;
  55        struct module *me;
  56};
  57
  58struct ebt_target {
  59        struct list_head list;
  60        const char name[EBT_FUNCTION_MAXNAMELEN];
  61        /* returns one of the standard EBT_* verdicts */
  62        unsigned int (*target)(struct sk_buff *skb,
  63                const struct net_device *in, const struct net_device *out,
  64                unsigned int hook_num, const struct xt_target *target,
  65                const void *targinfo);
  66        bool (*checkentry)(const char *table, const void *entry,
  67                const struct xt_target *target, void *targinfo,
  68                unsigned int hook_mask);
  69        void (*destroy)(const struct xt_target *target, void *targinfo);
  70        unsigned int targetsize;
  71        u_int8_t revision;
  72        u_int8_t family;
  73        struct module *me;
  74};
  75
  76/* used for jumping from and into user defined chains (udc) */
  77struct ebt_chainstack {
  78        struct ebt_entries *chaininfo; /* pointer to chain data */
  79        struct ebt_entry *e; /* pointer to entry data */
  80        unsigned int n; /* n'th entry */
  81};
  82
  83struct ebt_table_info {
  84        /* total size of the entries */
  85        unsigned int entries_size;
  86        unsigned int nentries;
  87        /* pointers to the start of the chains */
  88        struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
  89        /* room to maintain the stack used for jumping from and into udc */
  90        struct ebt_chainstack **chainstack;
  91        char *entries;
  92        struct ebt_counter counters[0] ____cacheline_aligned;
  93};
  94
  95struct ebt_table {
  96        struct list_head list;
  97        char name[EBT_TABLE_MAXNAMELEN];
  98        struct ebt_replace_kernel *table;
  99        unsigned int valid_hooks;
 100        rwlock_t lock;
 101        /* e.g. could be the table explicitly only allows certain
 102         * matches, targets, ... 0 == let it in */
 103        int (*check)(const struct ebt_table_info *info,
 104           unsigned int valid_hooks);
 105        /* the data used by the kernel */
 106        struct ebt_table_info *private;
 107        struct module *me;
 108};
 109
 110#define EBT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) & \
 111                     ~(__alignof__(struct _xt_align)-1))
 112extern int ebt_register_table(struct net *net,
 113                              const struct ebt_table *table,
 114                              const struct nf_hook_ops *ops,
 115                              struct ebt_table **res);
 116extern void ebt_unregister_table(struct net *net, struct ebt_table *table,
 117                                 const struct nf_hook_ops *);
 118extern unsigned int ebt_do_table(struct sk_buff *skb,
 119                                 const struct nf_hook_state *state,
 120                                 struct ebt_table *table);
 121
 122/* True if the hook mask denotes that the rule is in a base chain,
 123 * used in the check() functions */
 124#define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
 125/* Clear the bit in the hook mask that tells if the rule is on a base chain */
 126#define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
 127
 128static inline bool ebt_invalid_target(int target)
 129{
 130        return (target < -NUM_STANDARD_TARGETS || target >= 0);
 131}
 132
 133#endif
 134