include/linux/netfilter/x_tables.h

   1 #ifndef _X_TABLES_H
   2 #define _X_TABLES_H
   3 #include <linux/kernel.h>
   4 #include <linux/types.h>
   5
   6 #define XT_FUNCTION_MAXNAMELEN 30
   7 #define XT_EXTENSION_MAXNAMELEN 29
   8 #define XT_TABLE_MAXNAMELEN 32
   9
  10 struct xt_entry_match {
  11         union {
  12                 struct {
  13                         __u16 match_size;
  14
  15                         /* Used by userspace */
  16                         char name[XT_EXTENSION_MAXNAMELEN];
  17                         __u8 revision;
  18                 } user;
  19                 struct {
  20                         __u16 match_size;
  21
  22                         /* Used inside the kernel */
  23                         struct xt_match *match;
  24                 } kernel;
  25
  26                 /* Total length */
  27                 __u16 match_size;
  28         } u;
  29
  30         unsigned char data[0];
  31 };
  32
  33 struct xt_entry_target {
  34         union {
  35                 struct {
  36                         __u16 target_size;
  37
  38                         /* Used by userspace */
  39                         char name[XT_EXTENSION_MAXNAMELEN];
  40                         __u8 revision;
  41                 } user;
  42                 struct {
  43                         __u16 target_size;
  44
  45                         /* Used inside the kernel */
  46                         struct xt_target *target;
  47                 } kernel;
  48
  49                 /* Total length */
  50                 __u16 target_size;
  51         } u;
  52
  53         unsigned char data[0];
  54 };
  55
  56 #define XT_TARGET_INIT(__name, __size)                                         \
  57 {                                                                              \
  58         .target.u.user = {                                                     \
  59                 .target_size    = XT_ALIGN(__size),                            \
  60                 .name           = __name,                                      \
  61         },                                                                     \
  62 }
  63
  64 struct xt_standard_target {
  65         struct xt_entry_target target;
  66         int verdict;
  67 };
  68
  69 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  70  * kernel supports, if >= revision. */
  71 struct xt_get_revision {
  72         char name[XT_EXTENSION_MAXNAMELEN];
  73         __u8 revision;
  74 };
  75
  76 /* CONTINUE verdict for targets */
  77 #define XT_CONTINUE 0xFFFFFFFF
  78
  79 /* For standard target */
  80 #define XT_RETURN (-NF_REPEAT - 1)
  81
  82 /* this is a dummy structure to find out the alignment requirement for a struct
  83  * containing all the fundamental data types that are used in ipt_entry,
  84  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  85  * personal pleasure to remove it -HW
  86  */
  87 struct _xt_align {
  88         __u8 u8;
  89         __u16 u16;
  90         __u32 u32;
  91         __u64 u64;
  92 };
  93
  94 #define XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _xt_align))
  95
  96 /* Standard return verdict, or do jump. */
  97 #define XT_STANDARD_TARGET ""
  98 /* Error verdict. */
  99 #define XT_ERROR_TARGET "ERROR"
 100
 101 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
 102 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
 103
 104 struct xt_counters {
 105         __u64 pcnt, bcnt;                       /* Packet and byte counters */
 106 };
 107
 108 /* The argument to IPT_SO_ADD_COUNTERS. */
 109 struct xt_counters_info {
 110         /* Which table. */
 111         char name[XT_TABLE_MAXNAMELEN];
 112
 113         unsigned int num_counters;
 114
 115         /* The counters (actually `number' of these). */
 116         struct xt_counters counters[0];
 117 };
 118
 119 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 120
 121 /* fn returns 0 to continue iteration */
 122 #define XT_MATCH_ITERATE(type, e, fn, args...)                  \
 123 ({                                                              \
 124         unsigned int __i;                                       \
 125         int __ret = 0;                                          \
 126         struct xt_entry_match *__m;                             \
 127                                                                 \
 128         for (__i = sizeof(type);                                \
 129              __i < (e)->target_offset;                          \
 130              __i += __m->u.match_size) {                        \
 131                 __m = (void *)e + __i;                          \
 132                                                                 \
 133                 __ret = fn(__m , ## args);                      \
 134                 if (__ret != 0)                                 \
 135                         break;                                  \
 136         }                                                       \
 137         __ret;                                                  \
 138 })
 139
 140 /* fn returns 0 to continue iteration */
 141 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
 142 ({                                                              \
 143         unsigned int __i, __n;                                  \
 144         int __ret = 0;                                          \
 145         type *__entry;                                          \
 146                                                                 \
 147         for (__i = 0, __n = 0; __i < (size);                    \
 148              __i += __entry->next_offset, __n++) {              \
 149                 __entry = (void *)(entries) + __i;              \
 150                 if (__n < n)                                    \
 151                         continue;                               \
 152                                                                 \
 153                 __ret = fn(__entry , ## args);                  \
 154                 if (__ret != 0)                                 \
 155                         break;                                  \
 156         }                                                       \
 157         __ret;                                                  \
 158 })
 159
 160 /* fn returns 0 to continue iteration */
 161 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
 162         XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
 163
 164
 165 /* pos is normally a struct ipt_entry/ip6t_entry/etc. */
 166 #define xt_entry_foreach(pos, ehead, esize) \
 167         for ((pos) = (typeof(pos))(ehead); \
 168              (pos) < (typeof(pos))((char *)(ehead) + (esize)); \
 169              (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
 170
 171 /* can only be xt_entry_match, so no use of typeof here */
 172 #define xt_ematch_foreach(pos, entry) \
 173         for ((pos) = (struct xt_entry_match *)entry->elems; \
 174              (pos) < (struct xt_entry_match *)((char *)(entry) + \
 175                      (entry)->target_offset); \
 176              (pos) = (struct xt_entry_match *)((char *)(pos) + \
 177                      (pos)->u.match_size))
 178
 179
 180 #endif /* _X_TABLES_H */