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 struct xt_standard_target
  58 {
  59         struct xt_entry_target target;
  60         int verdict;
  61 };
  62
  63 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  64  * kernel supports, if >= revision. */
  65 struct xt_get_revision
  66 {
  67         char name[XT_FUNCTION_MAXNAMELEN-1];
  68
  69         u_int8_t revision;
  70 };
  71
  72 /* CONTINUE verdict for targets */
  73 #define XT_CONTINUE 0xFFFFFFFF
  74
  75 /* For standard target */
  76 #define XT_RETURN (-NF_REPEAT - 1)
  77
  78 /* this is a dummy structure to find out the alignment requirement for a struct
  79  * containing all the fundamental data types that are used in ipt_entry,
  80  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  81  * personal pleasure to remove it -HW
  82  */
  83 struct _xt_align
  84 {
  85         u_int8_t u8;
  86         u_int16_t u16;
  87         u_int32_t u32;
  88         u_int64_t u64;
  89 };
  90
  91 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1))  \
  92                         & ~(__alignof__(struct _xt_align)-1))
  93
  94 /* Standard return verdict, or do jump. */
  95 #define XT_STANDARD_TARGET ""
  96 /* Error verdict. */
  97 #define XT_ERROR_TARGET "ERROR"
  98
  99 /*
 100  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 101  * Unlike BSD Linux inherits IP options so you don't have to use a raw
 102  * socket for this. Instead we check rights in the calls. */
 103 #define XT_BASE_CTL             64      /* base for firewall socket options */
 104
 105 #define XT_SO_SET_REPLACE       (XT_BASE_CTL)
 106 #define XT_SO_SET_ADD_COUNTERS  (XT_BASE_CTL + 1)
 107 #define XT_SO_SET_MAX           XT_SO_SET_ADD_COUNTERS
 108
 109 #define XT_SO_GET_INFO                  (XT_BASE_CTL)
 110 #define XT_SO_GET_ENTRIES               (XT_BASE_CTL + 1)
 111 #define XT_SO_GET_REVISION_MATCH        (XT_BASE_CTL + 2)
 112 #define XT_SO_GET_REVISION_TARGET       (XT_BASE_CTL + 3)
 113 #define XT_SO_GET_MAX                   XT_SO_GET_REVISION_TARGET
 114
 115 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
 116 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
 117
 118 struct xt_counters
 119 {
 120         u_int64_t pcnt, bcnt;                   /* Packet and byte counters */
 121 };
 122
 123 /* The argument to IPT_SO_ADD_COUNTERS. */
 124 struct xt_counters_info
 125 {
 126         /* Which table. */
 127         char name[XT_TABLE_MAXNAMELEN];
 128
 129         unsigned int num_counters;
 130
 131         /* The counters (actually `number' of these). */
 132         struct xt_counters counters[0];
 133 };
 134
 135 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 136
 137 #ifdef __KERNEL__
 138
 139 #include <linux/netdevice.h>
 140
 141 struct xt_match
 142 {
 143         struct list_head list;
 144
 145         const char name[XT_FUNCTION_MAXNAMELEN-1];
 146
 147         /* Return true or false: return FALSE and set *hotdrop = 1 to
 148            force immediate packet drop. */
 149         /* Arguments changed since 2.6.9, as this must now handle
 150            non-linear skb, using skb_header_pointer and
 151            skb_ip_make_writable. */
 152         int (*match)(const struct sk_buff *skb,
 153                      const struct net_device *in,
 154                      const struct net_device *out,
 155                      const struct xt_match *match,
 156                      const void *matchinfo,
 157                      int offset,
 158                      unsigned int protoff,
 159                      int *hotdrop);
 160
 161         /* Called when user tries to insert an entry of this type. */
 162         /* Should return true or false. */
 163         int (*checkentry)(const char *tablename,
 164                           const void *ip,
 165                           const struct xt_match *match,
 166                           void *matchinfo,
 167                           unsigned int hook_mask);
 168
 169         /* Called when entry of this type deleted. */
 170         void (*destroy)(const struct xt_match *match, void *matchinfo);
 171
 172         /* Called when userspace align differs from kernel space one */
 173         void (*compat_from_user)(void *dst, void *src);
 174         int (*compat_to_user)(void __user *dst, void *src);
 175
 176         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 177         struct module *me;
 178
 179         /* Free to use by each match */
 180         unsigned long data;
 181
 182         char *table;
 183         unsigned int matchsize;
 184         unsigned int compatsize;
 185         unsigned int hooks;
 186         unsigned short proto;
 187
 188         unsigned short family;
 189         u_int8_t revision;
 190 };
 191
 192 /* Registration hooks for targets. */
 193 struct xt_target
 194 {
 195         struct list_head list;
 196
 197         const char name[XT_FUNCTION_MAXNAMELEN-1];
 198
 199         /* Returns verdict. Argument order changed since 2.6.9, as this
 200            must now handle non-linear skbs, using skb_copy_bits and
 201            skb_ip_make_writable. */
 202         unsigned int (*target)(struct sk_buff **pskb,
 203                                const struct net_device *in,
 204                                const struct net_device *out,
 205                                unsigned int hooknum,
 206                                const struct xt_target *target,
 207                                const void *targinfo);
 208
 209         /* Called when user tries to insert an entry of this type:
 210            hook_mask is a bitmask of hooks from which it can be
 211            called. */
 212         /* Should return true or false. */
 213         int (*checkentry)(const char *tablename,
 214                           const void *entry,
 215                           const struct xt_target *target,
 216                           void *targinfo,
 217                           unsigned int hook_mask);
 218
 219         /* Called when entry of this type deleted. */
 220         void (*destroy)(const struct xt_target *target, void *targinfo);
 221
 222         /* Called when userspace align differs from kernel space one */
 223         void (*compat_from_user)(void *dst, void *src);
 224         int (*compat_to_user)(void __user *dst, void *src);
 225
 226         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 227         struct module *me;
 228
 229         char *table;
 230         unsigned int targetsize;
 231         unsigned int compatsize;
 232         unsigned int hooks;
 233         unsigned short proto;
 234
 235         unsigned short family;
 236         u_int8_t revision;
 237 };
 238
 239 /* Furniture shopping... */
 240 struct xt_table
 241 {
 242         struct list_head list;
 243
 244         /* A unique name... */
 245         char name[XT_TABLE_MAXNAMELEN];
 246
 247         /* What hooks you will enter on */
 248         unsigned int valid_hooks;
 249
 250         /* Lock for the curtain */
 251         rwlock_t lock;
 252
 253         /* Man behind the curtain... */
 254         //struct ip6t_table_info *private;
 255         void *private;
 256
 257         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 258         struct module *me;
 259
 260         int af;         /* address/protocol family */
 261 };
 262
 263 #include <linux/netfilter_ipv4.h>
 264
 265 /* The table itself */
 266 struct xt_table_info
 267 {
 268         /* Size per table */
 269         unsigned int size;
 270         /* Number of entries: FIXME. --RR */
 271         unsigned int number;
 272         /* Initial number of entries. Needed for module usage count */
 273         unsigned int initial_entries;
 274
 275         /* Entry points and underflows */
 276         unsigned int hook_entry[NF_IP_NUMHOOKS];
 277         unsigned int underflow[NF_IP_NUMHOOKS];
 278
 279         /* ipt_entry tables: one per CPU */
 280         char *entries[NR_CPUS];
 281 };
 282
 283 extern int xt_register_target(struct xt_target *target);
 284 extern void xt_unregister_target(struct xt_target *target);
 285 extern int xt_register_targets(struct xt_target *target, unsigned int n);
 286 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
 287
 288 extern int xt_register_match(struct xt_match *target);
 289 extern void xt_unregister_match(struct xt_match *target);
 290 extern int xt_register_matches(struct xt_match *match, unsigned int n);
 291 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
 292
 293 extern int xt_check_match(const struct xt_match *match, unsigned short family,
 294                           unsigned int size, const char *table, unsigned int hook,
 295                           unsigned short proto, int inv_proto);
 296 extern int xt_check_target(const struct xt_target *target, unsigned short family,
 297                            unsigned int size, const char *table, unsigned int hook,
 298                            unsigned short proto, int inv_proto);
 299
 300 extern int xt_register_table(struct xt_table *table,
 301                              struct xt_table_info *bootstrap,
 302                              struct xt_table_info *newinfo);
 303 extern void *xt_unregister_table(struct xt_table *table);
 304
 305 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
 306                                               unsigned int num_counters,
 307                                               struct xt_table_info *newinfo,
 308                                               int *error);
 309
 310 extern struct xt_match *xt_find_match(int af, const char *name, u8 revision);
 311 extern struct xt_target *xt_find_target(int af, const char *name, u8 revision);
 312 extern struct xt_target *xt_request_find_target(int af, const char *name,
 313                                                 u8 revision);
 314 extern int xt_find_revision(int af, const char *name, u8 revision, int target,
 315                             int *err);
 316
 317 extern struct xt_table *xt_find_table_lock(int af, const char *name);
 318 extern void xt_table_unlock(struct xt_table *t);
 319
 320 extern int xt_proto_init(int af);
 321 extern void xt_proto_fini(int af);
 322
 323 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
 324 extern void xt_free_table_info(struct xt_table_info *info);
 325
 326 #ifdef CONFIG_COMPAT
 327 #include <net/compat.h>
 328
 329 struct compat_xt_entry_match
 330 {
 331         union {
 332                 struct {
 333                         u_int16_t match_size;
 334                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 335                         u_int8_t revision;
 336                 } user;
 337                 struct {
 338                         u_int16_t match_size;
 339                         compat_uptr_t match;
 340                 } kernel;
 341                 u_int16_t match_size;
 342         } u;
 343         unsigned char data[0];
 344 };
 345
 346 struct compat_xt_entry_target
 347 {
 348         union {
 349                 struct {
 350                         u_int16_t target_size;
 351                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 352                         u_int8_t revision;
 353                 } user;
 354                 struct {
 355                         u_int16_t target_size;
 356                         compat_uptr_t target;
 357                 } kernel;
 358                 u_int16_t target_size;
 359         } u;
 360         unsigned char data[0];
 361 };
 362
 363 /* FIXME: this works only on 32 bit tasks
 364  * need to change whole approach in order to calculate align as function of
 365  * current task alignment */
 366
 367 struct compat_xt_counters
 368 {
 369 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
 370         u_int32_t cnt[4];
 371 #else
 372         u_int64_t cnt[2];
 373 #endif
 374 };
 375
 376 struct compat_xt_counters_info
 377 {
 378         char name[XT_TABLE_MAXNAMELEN];
 379         compat_uint_t num_counters;
 380         struct compat_xt_counters counters[0];
 381 };
 382
 383 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
 384                 & ~(__alignof__(struct compat_xt_counters)-1))
 385
 386 extern void xt_compat_lock(int af);
 387 extern void xt_compat_unlock(int af);
 388
 389 extern int xt_compat_match_offset(struct xt_match *match);
 390 extern void xt_compat_match_from_user(struct xt_entry_match *m,
 391                                       void **dstptr, int *size);
 392 extern int xt_compat_match_to_user(struct xt_entry_match *m,
 393                                    void __user **dstptr, int *size);
 394
 395 extern int xt_compat_target_offset(struct xt_target *target);
 396 extern void xt_compat_target_from_user(struct xt_entry_target *t,
 397                                        void **dstptr, int *size);
 398 extern int xt_compat_target_to_user(struct xt_entry_target *t,
 399                                     void __user **dstptr, int *size);
 400
 401 #endif /* CONFIG_COMPAT */
 402 #endif /* __KERNEL__ */
 403
 404 #endif /* _X_TABLES_H */