include/linux/netfilter_bridge/ebtables.h

   1 /*
   2  *  ebtables
   3  *
   4  *      Authors:
   5  *      Bart De Schuymer                <bdschuym@pandora.be>
   6  *
   7  *  ebtables.c,v 2.0, April, 2002
   8  *
   9  *  This code is strongly inspired by the iptables code which is
  10  *  Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
  11  */
  12 #ifndef __LINUX_BRIDGE_EFF_H
  13 #define __LINUX_BRIDGE_EFF_H
  14
  15 #include <linux/if.h>
  16 #include <linux/if_ether.h>
  17 #include <uapi/linux/netfilter_bridge/ebtables.h>
  18
  19 /* return values for match() functions */
  20 #define EBT_MATCH 0
  21 #define EBT_NOMATCH 1
  22
  23 struct ebt_match {
  24         struct list_head list;
  25         const char name[EBT_FUNCTION_MAXNAMELEN];
  26         bool (*match)(const struct sk_buff *skb, const struct net_device *in,
  27                 const struct net_device *out, const struct xt_match *match,
  28                 const void *matchinfo, int offset, unsigned int protoff,
  29                 bool *hotdrop);
  30         bool (*checkentry)(const char *table, const void *entry,
  31                 const struct xt_match *match, void *matchinfo,
  32                 unsigned int hook_mask);
  33         void (*destroy)(const struct xt_match *match, void *matchinfo);
  34         unsigned int matchsize;
  35         u_int8_t revision;
  36         u_int8_t family;
  37         struct module *me;
  38 };
  39
  40 struct ebt_watcher {
  41         struct list_head list;
  42         const char name[EBT_FUNCTION_MAXNAMELEN];
  43         unsigned int (*target)(struct sk_buff *skb,
  44                 const struct net_device *in, const struct net_device *out,
  45                 unsigned int hook_num, const struct xt_target *target,
  46                 const void *targinfo);
  47         bool (*checkentry)(const char *table, const void *entry,
  48                 const struct xt_target *target, void *targinfo,
  49                 unsigned int hook_mask);
  50         void (*destroy)(const struct xt_target *target, void *targinfo);
  51         unsigned int targetsize;
  52         u_int8_t revision;
  53         u_int8_t family;
  54         struct module *me;
  55 };
  56
  57 struct ebt_target {
  58         struct list_head list;
  59         const char name[EBT_FUNCTION_MAXNAMELEN];
  60         /* returns one of the standard EBT_* verdicts */
  61         unsigned int (*target)(struct sk_buff *skb,
  62                 const struct net_device *in, const struct net_device *out,
  63                 unsigned int hook_num, const struct xt_target *target,
  64                 const void *targinfo);
  65         bool (*checkentry)(const char *table, const void *entry,
  66                 const struct xt_target *target, void *targinfo,
  67                 unsigned int hook_mask);
  68         void (*destroy)(const struct xt_target *target, void *targinfo);
  69         unsigned int targetsize;
  70         u_int8_t revision;
  71         u_int8_t family;
  72         struct module *me;
  73 };
  74
  75 /* used for jumping from and into user defined chains (udc) */
  76 struct ebt_chainstack {
  77         struct ebt_entries *chaininfo; /* pointer to chain data */
  78         struct ebt_entry *e; /* pointer to entry data */
  79         unsigned int n; /* n'th entry */
  80 };
  81
  82 struct ebt_table_info {
  83         /* total size of the entries */
  84         unsigned int entries_size;
  85         unsigned int nentries;
  86         /* pointers to the start of the chains */
  87         struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
  88         /* room to maintain the stack used for jumping from and into udc */
  89         struct ebt_chainstack **chainstack;
  90         char *entries;
  91         struct ebt_counter counters[0] ____cacheline_aligned;
  92 };
  93
  94 struct ebt_table {
  95         struct list_head list;
  96         char name[EBT_TABLE_MAXNAMELEN];
  97         struct ebt_replace_kernel *table;
  98         unsigned int valid_hooks;
  99         rwlock_t lock;
 100         /* e.g. could be the table explicitly only allows certain
 101          * matches, targets, ... 0 == let it in */
 102         int (*check)(const struct ebt_table_info *info,
 103            unsigned int valid_hooks);
 104         /* the data used by the kernel */
 105         struct ebt_table_info *private;
 106         struct module *me;
 107 };
 108
 109 #define EBT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) & \
 110                      ~(__alignof__(struct _xt_align)-1))
 111 extern struct ebt_table *ebt_register_table(struct net *net,
 112                                             const struct ebt_table *table);
 113 extern void ebt_unregister_table(struct net *net, struct ebt_table *table);
 114 extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb,
 115    const struct net_device *in, const struct net_device *out,
 116    struct ebt_table *table);
 117
 118 /* Used in the kernel match() functions */
 119 #define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
 120 /* True if the hook mask denotes that the rule is in a base chain,
 121  * used in the check() functions */
 122 #define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
 123 /* Clear the bit in the hook mask that tells if the rule is on a base chain */
 124 #define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
 125 /* True if the target is not a standard target */
 126 #define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0)
 127
 128 #endif