include/linux/netfilter_ipv4/ip_tables.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * 25-Jul-1998 Major changes to allow for ip chain table
   4  *
   5  * 3-Jan-2000 Named tables to allow packet selection for different uses.
   6  */
   7
   8 /*
   9  *      Format of an IP firewall descriptor
  10  *
  11  *      src, dst, src_mask, dst_mask are always stored in network byte order.
  12  *      flags are stored in host byte order (of course).
  13  *      Port numbers are stored in HOST byte order.
  14  */
  15 #ifndef _IPTABLES_H
  16 #define _IPTABLES_H
  17
  18 #include <linux/if.h>
  19 #include <linux/in.h>
  20 #include <linux/ip.h>
  21 #include <linux/skbuff.h>
  22
  23 #include <linux/init.h>
  24 #include <uapi/linux/netfilter_ipv4/ip_tables.h>
  25
  26 extern void ipt_init(void) __init;
  27
  28 int ipt_register_table(struct net *net, const struct xt_table *table,
  29                        const struct ipt_replace *repl,
  30                        const struct nf_hook_ops *ops, struct xt_table **res);
  31 void ipt_unregister_table(struct net *net, struct xt_table *table,
  32                           const struct nf_hook_ops *ops);
  33
  34 /* Standard entry. */
  35 struct ipt_standard {
  36         struct ipt_entry entry;
  37         struct xt_standard_target target;
  38 };
  39
  40 struct ipt_error {
  41         struct ipt_entry entry;
  42         struct xt_error_target target;
  43 };
  44
  45 #define IPT_ENTRY_INIT(__size)                                                 \
  46 {                                                                              \
  47         .target_offset  = sizeof(struct ipt_entry),                            \
  48         .next_offset    = (__size),                                            \
  49 }
  50
  51 #define IPT_STANDARD_INIT(__verdict)                                           \
  52 {                                                                              \
  53         .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_standard)),         \
  54         .target         = XT_TARGET_INIT(XT_STANDARD_TARGET,                   \
  55                                          sizeof(struct xt_standard_target)),   \
  56         .target.verdict = -(__verdict) - 1,                                    \
  57 }
  58
  59 #define IPT_ERROR_INIT                                                         \
  60 {                                                                              \
  61         .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_error)),            \
  62         .target         = XT_TARGET_INIT(XT_ERROR_TARGET,                      \
  63                                          sizeof(struct xt_error_target)),      \
  64         .target.errorname = "ERROR",                                           \
  65 }
  66
  67 extern void *ipt_alloc_initial_table(const struct xt_table *);
  68 extern unsigned int ipt_do_table(struct sk_buff *skb,
  69                                  const struct nf_hook_state *state,
  70                                  struct xt_table *table);
  71
  72 #ifdef CONFIG_COMPAT
  73 #include <net/compat.h>
  74
  75 struct compat_ipt_entry {
  76         struct ipt_ip ip;
  77         compat_uint_t nfcache;
  78         __u16 target_offset;
  79         __u16 next_offset;
  80         compat_uint_t comefrom;
  81         struct compat_xt_counters counters;
  82         unsigned char elems[0];
  83 };
  84
  85 /* Helper functions */
  86 static inline struct xt_entry_target *
  87 compat_ipt_get_target(struct compat_ipt_entry *e)
  88 {
  89         return (void *)e + e->target_offset;
  90 }
  91
  92 #endif /* CONFIG_COMPAT */
  93 #endif /* _IPTABLES_H */