include/linux/netfilter_arp/arp_tables.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *      Format of an ARP firewall descriptor
   4  *
   5  *      src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in
   6  *      network byte order.
   7  *      flags are stored in host byte order (of course).
   8  */
   9 #ifndef _ARPTABLES_H
  10 #define _ARPTABLES_H
  11
  12 #include <linux/if.h>
  13 #include <linux/in.h>
  14 #include <linux/if_arp.h>
  15 #include <linux/skbuff.h>
  16 #include <uapi/linux/netfilter_arp/arp_tables.h>
  17
  18 /* Standard entry. */
  19 struct arpt_standard {
  20         struct arpt_entry entry;
  21         struct xt_standard_target target;
  22 };
  23
  24 struct arpt_error {
  25         struct arpt_entry entry;
  26         struct xt_error_target target;
  27 };
  28
  29 #define ARPT_ENTRY_INIT(__size)                                                \
  30 {                                                                              \
  31         .target_offset  = sizeof(struct arpt_entry),                           \
  32         .next_offset    = (__size),                                            \
  33 }
  34
  35 #define ARPT_STANDARD_INIT(__verdict)                                          \
  36 {                                                                              \
  37         .entry          = ARPT_ENTRY_INIT(sizeof(struct arpt_standard)),       \
  38         .target         = XT_TARGET_INIT(XT_STANDARD_TARGET,                   \
  39                                          sizeof(struct xt_standard_target)), \
  40         .target.verdict = -(__verdict) - 1,                                    \
  41 }
  42
  43 #define ARPT_ERROR_INIT                                                        \
  44 {                                                                              \
  45         .entry          = ARPT_ENTRY_INIT(sizeof(struct arpt_error)),          \
  46         .target         = XT_TARGET_INIT(XT_ERROR_TARGET,                      \
  47                                          sizeof(struct xt_error_target)),      \
  48         .target.errorname = "ERROR",                                           \
  49 }
  50
  51 extern void *arpt_alloc_initial_table(const struct xt_table *);
  52 int arpt_register_table(struct net *net, const struct xt_table *table,
  53                         const struct arpt_replace *repl,
  54                         const struct nf_hook_ops *ops, struct xt_table **res);
  55 void arpt_unregister_table(struct net *net, struct xt_table *table,
  56                            const struct nf_hook_ops *ops);
  57 extern unsigned int arpt_do_table(struct sk_buff *skb,
  58                                   const struct nf_hook_state *state,
  59                                   struct xt_table *table);
  60
  61 #ifdef CONFIG_COMPAT
  62 #include <net/compat.h>
  63
  64 struct compat_arpt_entry {
  65         struct arpt_arp arp;
  66         __u16 target_offset;
  67         __u16 next_offset;
  68         compat_uint_t comefrom;
  69         struct compat_xt_counters counters;
  70         unsigned char elems[0];
  71 };
  72
  73 static inline struct xt_entry_target *
  74 compat_arpt_get_target(struct compat_arpt_entry *e)
  75 {
  76         return (void *)e + e->target_offset;
  77 }
  78
  79 #endif /* CONFIG_COMPAT */
  80 #endif /* _ARPTABLES_H */