include/linux/netfilter/x_tables.h

   1 #ifndef _X_TABLES_H
   2 #define _X_TABLES_H
   3
   4 #define XT_FUNCTION_MAXNAMELEN 30
   5 #define XT_TABLE_MAXNAMELEN 32
   6
   7 struct xt_entry_match
   8 {
   9         union {
  10                 struct {
  11                         u_int16_t match_size;
  12
  13                         /* Used by userspace */
  14                         char name[XT_FUNCTION_MAXNAMELEN-1];
  15
  16                         u_int8_t revision;
  17                 } user;
  18                 struct {
  19                         u_int16_t match_size;
  20
  21                         /* Used inside the kernel */
  22                         struct xt_match *match;
  23                 } kernel;
  24
  25                 /* Total length */
  26                 u_int16_t match_size;
  27         } u;
  28
  29         unsigned char data[0];
  30 };
  31
  32 struct xt_entry_target
  33 {
  34         union {
  35                 struct {
  36                         u_int16_t target_size;
  37
  38                         /* Used by userspace */
  39                         char name[XT_FUNCTION_MAXNAMELEN-1];
  40
  41                         u_int8_t revision;
  42                 } user;
  43                 struct {
  44                         u_int16_t target_size;
  45
  46                         /* Used inside the kernel */
  47                         struct xt_target *target;
  48                 } kernel;
  49
  50                 /* Total length */
  51                 u_int16_t target_size;
  52         } u;
  53
  54         unsigned char data[0];
  55 };
  56
  57 #define XT_TARGET_INIT(__name, __size)                                         \
  58 {                                                                              \
  59         .target.u.user = {                                                     \
  60                 .target_size    = XT_ALIGN(__size),                            \
  61                 .name           = __name,                                      \
  62         },                                                                     \
  63 }
  64
  65 struct xt_standard_target
  66 {
  67         struct xt_entry_target target;
  68         int verdict;
  69 };
  70
  71 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  72  * kernel supports, if >= revision. */
  73 struct xt_get_revision
  74 {
  75         char name[XT_FUNCTION_MAXNAMELEN-1];
  76
  77         u_int8_t revision;
  78 };
  79
  80 /* CONTINUE verdict for targets */
  81 #define XT_CONTINUE 0xFFFFFFFF
  82
  83 /* For standard target */
  84 #define XT_RETURN (-NF_REPEAT - 1)
  85
  86 /* this is a dummy structure to find out the alignment requirement for a struct
  87  * containing all the fundamental data types that are used in ipt_entry,
  88  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  89  * personal pleasure to remove it -HW
  90  */
  91 struct _xt_align
  92 {
  93         u_int8_t u8;
  94         u_int16_t u16;
  95         u_int32_t u32;
  96         u_int64_t u64;
  97 };
  98
  99 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1))  \
 100                         & ~(__alignof__(struct _xt_align)-1))
 101
 102 /* Standard return verdict, or do jump. */
 103 #define XT_STANDARD_TARGET ""
 104 /* Error verdict. */
 105 #define XT_ERROR_TARGET "ERROR"
 106
 107 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
 108 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
 109
 110 struct xt_counters
 111 {
 112         u_int64_t pcnt, bcnt;                   /* Packet and byte counters */
 113 };
 114
 115 /* The argument to IPT_SO_ADD_COUNTERS. */
 116 struct xt_counters_info
 117 {
 118         /* Which table. */
 119         char name[XT_TABLE_MAXNAMELEN];
 120
 121         unsigned int num_counters;
 122
 123         /* The counters (actually `number' of these). */
 124         struct xt_counters counters[0];
 125 };
 126
 127 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 128
 129 #ifdef __KERNEL__
 130
 131 #include <linux/netdevice.h>
 132
 133 struct xt_match
 134 {
 135         struct list_head list;
 136
 137         const char name[XT_FUNCTION_MAXNAMELEN-1];
 138
 139         /* Return true or false: return FALSE and set *hotdrop = 1 to
 140            force immediate packet drop. */
 141         /* Arguments changed since 2.6.9, as this must now handle
 142            non-linear skb, using skb_header_pointer and
 143            skb_ip_make_writable. */
 144         bool (*match)(const struct sk_buff *skb,
 145                       const struct net_device *in,
 146                       const struct net_device *out,
 147                       const struct xt_match *match,
 148                       const void *matchinfo,
 149                       int offset,
 150                       unsigned int protoff,
 151                       bool *hotdrop);
 152
 153         /* Called when user tries to insert an entry of this type. */
 154         /* Should return true or false. */
 155         bool (*checkentry)(const char *tablename,
 156                            const void *ip,
 157                            const struct xt_match *match,
 158                            void *matchinfo,
 159                            unsigned int hook_mask);
 160
 161         /* Called when entry of this type deleted. */
 162         void (*destroy)(const struct xt_match *match, void *matchinfo);
 163
 164         /* Called when userspace align differs from kernel space one */
 165         void (*compat_from_user)(void *dst, void *src);
 166         int (*compat_to_user)(void __user *dst, void *src);
 167
 168         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 169         struct module *me;
 170
 171         /* Free to use by each match */
 172         unsigned long data;
 173
 174         char *table;
 175         unsigned int matchsize;
 176         unsigned int compatsize;
 177         unsigned int hooks;
 178         unsigned short proto;
 179
 180         unsigned short family;
 181         u_int8_t revision;
 182 };
 183
 184 /* Registration hooks for targets. */
 185 struct xt_target
 186 {
 187         struct list_head list;
 188
 189         const char name[XT_FUNCTION_MAXNAMELEN-1];
 190
 191         /* Returns verdict. Argument order changed since 2.6.9, as this
 192            must now handle non-linear skbs, using skb_copy_bits and
 193            skb_ip_make_writable. */
 194         unsigned int (*target)(struct sk_buff *skb,
 195                                const struct net_device *in,
 196                                const struct net_device *out,
 197                                unsigned int hooknum,
 198                                const struct xt_target *target,
 199                                const void *targinfo);
 200
 201         /* Called when user tries to insert an entry of this type:
 202            hook_mask is a bitmask of hooks from which it can be
 203            called. */
 204         /* Should return true or false. */
 205         bool (*checkentry)(const char *tablename,
 206                            const void *entry,
 207                            const struct xt_target *target,
 208                            void *targinfo,
 209                            unsigned int hook_mask);
 210
 211         /* Called when entry of this type deleted. */
 212         void (*destroy)(const struct xt_target *target, void *targinfo);
 213
 214         /* Called when userspace align differs from kernel space one */
 215         void (*compat_from_user)(void *dst, void *src);
 216         int (*compat_to_user)(void __user *dst, void *src);
 217
 218         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 219         struct module *me;
 220
 221         char *table;
 222         unsigned int targetsize;
 223         unsigned int compatsize;
 224         unsigned int hooks;
 225         unsigned short proto;
 226
 227         unsigned short family;
 228         u_int8_t revision;
 229 };
 230
 231 /* Furniture shopping... */
 232 struct xt_table
 233 {
 234         struct list_head list;
 235
 236         /* A unique name... */
 237         char name[XT_TABLE_MAXNAMELEN];
 238
 239         /* What hooks you will enter on */
 240         unsigned int valid_hooks;
 241
 242         /* Lock for the curtain */
 243         rwlock_t lock;
 244
 245         /* Man behind the curtain... */
 246         //struct ip6t_table_info *private;
 247         void *private;
 248
 249         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 250         struct module *me;
 251
 252         int af;         /* address/protocol family */
 253 };
 254
 255 #include <linux/netfilter_ipv4.h>
 256
 257 /* The table itself */
 258 struct xt_table_info
 259 {
 260         /* Size per table */
 261         unsigned int size;
 262         /* Number of entries: FIXME. --RR */
 263         unsigned int number;
 264         /* Initial number of entries. Needed for module usage count */
 265         unsigned int initial_entries;
 266
 267         /* Entry points and underflows */
 268         unsigned int hook_entry[NF_INET_NUMHOOKS];
 269         unsigned int underflow[NF_INET_NUMHOOKS];
 270
 271         /* ipt_entry tables: one per CPU */
 272         char *entries[NR_CPUS];
 273 };
 274
 275 extern int xt_register_target(struct xt_target *target);
 276 extern void xt_unregister_target(struct xt_target *target);
 277 extern int xt_register_targets(struct xt_target *target, unsigned int n);
 278 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
 279
 280 extern int xt_register_match(struct xt_match *target);
 281 extern void xt_unregister_match(struct xt_match *target);
 282 extern int xt_register_matches(struct xt_match *match, unsigned int n);
 283 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
 284
 285 extern int xt_check_match(const struct xt_match *match, unsigned short family,
 286                           unsigned int size, const char *table, unsigned int hook,
 287                           unsigned short proto, int inv_proto);
 288 extern int xt_check_target(const struct xt_target *target, unsigned short family,
 289                            unsigned int size, const char *table, unsigned int hook,
 290                            unsigned short proto, int inv_proto);
 291
 292 extern int xt_register_table(struct xt_table *table,
 293                              struct xt_table_info *bootstrap,
 294                              struct xt_table_info *newinfo);
 295 extern void *xt_unregister_table(struct xt_table *table);
 296
 297 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
 298                                               unsigned int num_counters,
 299                                               struct xt_table_info *newinfo,
 300                                               int *error);
 301
 302 extern struct xt_match *xt_find_match(int af, const char *name, u8 revision);
 303 extern struct xt_target *xt_find_target(int af, const char *name, u8 revision);
 304 extern struct xt_target *xt_request_find_target(int af, const char *name,
 305                                                 u8 revision);
 306 extern int xt_find_revision(int af, const char *name, u8 revision, int target,
 307                             int *err);
 308
 309 extern struct xt_table *xt_find_table_lock(int af, const char *name);
 310 extern void xt_table_unlock(struct xt_table *t);
 311
 312 extern int xt_proto_init(int af);
 313 extern void xt_proto_fini(int af);
 314
 315 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
 316 extern void xt_free_table_info(struct xt_table_info *info);
 317
 318 #ifdef CONFIG_COMPAT
 319 #include <net/compat.h>
 320
 321 struct compat_xt_entry_match
 322 {
 323         union {
 324                 struct {
 325                         u_int16_t match_size;
 326                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 327                         u_int8_t revision;
 328                 } user;
 329                 struct {
 330                         u_int16_t match_size;
 331                         compat_uptr_t match;
 332                 } kernel;
 333                 u_int16_t match_size;
 334         } u;
 335         unsigned char data[0];
 336 };
 337
 338 struct compat_xt_entry_target
 339 {
 340         union {
 341                 struct {
 342                         u_int16_t target_size;
 343                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 344                         u_int8_t revision;
 345                 } user;
 346                 struct {
 347                         u_int16_t target_size;
 348                         compat_uptr_t target;
 349                 } kernel;
 350                 u_int16_t target_size;
 351         } u;
 352         unsigned char data[0];
 353 };
 354
 355 /* FIXME: this works only on 32 bit tasks
 356  * need to change whole approach in order to calculate align as function of
 357  * current task alignment */
 358
 359 struct compat_xt_counters
 360 {
 361 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
 362         u_int32_t cnt[4];
 363 #else
 364         u_int64_t cnt[2];
 365 #endif
 366 };
 367
 368 struct compat_xt_counters_info
 369 {
 370         char name[XT_TABLE_MAXNAMELEN];
 371         compat_uint_t num_counters;
 372         struct compat_xt_counters counters[0];
 373 };
 374
 375 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
 376                 & ~(__alignof__(struct compat_xt_counters)-1))
 377
 378 extern void xt_compat_lock(int af);
 379 extern void xt_compat_unlock(int af);
 380
 381 extern int xt_compat_match_offset(struct xt_match *match);
 382 extern void xt_compat_match_from_user(struct xt_entry_match *m,
 383                                       void **dstptr, int *size);
 384 extern int xt_compat_match_to_user(struct xt_entry_match *m,
 385                                    void __user **dstptr, int *size);
 386
 387 extern int xt_compat_target_offset(struct xt_target *target);
 388 extern void xt_compat_target_from_user(struct xt_entry_target *t,
 389                                        void **dstptr, int *size);
 390 extern int xt_compat_target_to_user(struct xt_entry_target *t,
 391                                     void __user **dstptr, int *size);
 392
 393 #endif /* CONFIG_COMPAT */
 394 #endif /* __KERNEL__ */
 395
 396 #endif /* _X_TABLES_H */