include/linux/netfilter/x_tables.h

   1 #ifndef _X_TABLES_H
   2 #define _X_TABLES_H
   3
   4 #include <linux/types.h>
   5
   6 #define XT_FUNCTION_MAXNAMELEN 30
   7 #define XT_TABLE_MAXNAMELEN 32
   8
   9 struct xt_entry_match
  10 {
  11         union {
  12                 struct {
  13                         __u16 match_size;
  14
  15                         /* Used by userspace */
  16                         char name[XT_FUNCTION_MAXNAMELEN-1];
  17
  18                         __u8 revision;
  19                 } user;
  20                 struct {
  21                         __u16 match_size;
  22
  23                         /* Used inside the kernel */
  24                         struct xt_match *match;
  25                 } kernel;
  26
  27                 /* Total length */
  28                 __u16 match_size;
  29         } u;
  30
  31         unsigned char data[0];
  32 };
  33
  34 struct xt_entry_target
  35 {
  36         union {
  37                 struct {
  38                         __u16 target_size;
  39
  40                         /* Used by userspace */
  41                         char name[XT_FUNCTION_MAXNAMELEN-1];
  42
  43                         __u8 revision;
  44                 } user;
  45                 struct {
  46                         __u16 target_size;
  47
  48                         /* Used inside the kernel */
  49                         struct xt_target *target;
  50                 } kernel;
  51
  52                 /* Total length */
  53                 __u16 target_size;
  54         } u;
  55
  56         unsigned char data[0];
  57 };
  58
  59 #define XT_TARGET_INIT(__name, __size)                                         \
  60 {                                                                              \
  61         .target.u.user = {                                                     \
  62                 .target_size    = XT_ALIGN(__size),                            \
  63                 .name           = __name,                                      \
  64         },                                                                     \
  65 }
  66
  67 struct xt_standard_target
  68 {
  69         struct xt_entry_target target;
  70         int verdict;
  71 };
  72
  73 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  74  * kernel supports, if >= revision. */
  75 struct xt_get_revision
  76 {
  77         char name[XT_FUNCTION_MAXNAMELEN-1];
  78
  79         __u8 revision;
  80 };
  81
  82 /* CONTINUE verdict for targets */
  83 #define XT_CONTINUE 0xFFFFFFFF
  84
  85 /* For standard target */
  86 #define XT_RETURN (-NF_REPEAT - 1)
  87
  88 /* this is a dummy structure to find out the alignment requirement for a struct
  89  * containing all the fundamental data types that are used in ipt_entry,
  90  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  91  * personal pleasure to remove it -HW
  92  */
  93 struct _xt_align
  94 {
  95         __u8 u8;
  96         __u16 u16;
  97         __u32 u32;
  98         __u64 u64;
  99 };
 100
 101 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1))  \
 102                         & ~(__alignof__(struct _xt_align)-1))
 103
 104 /* Standard return verdict, or do jump. */
 105 #define XT_STANDARD_TARGET ""
 106 /* Error verdict. */
 107 #define XT_ERROR_TARGET "ERROR"
 108
 109 #define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
 110 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
 111
 112 struct xt_counters
 113 {
 114         __u64 pcnt, bcnt;                       /* Packet and byte counters */
 115 };
 116
 117 /* The argument to IPT_SO_ADD_COUNTERS. */
 118 struct xt_counters_info
 119 {
 120         /* Which table. */
 121         char name[XT_TABLE_MAXNAMELEN];
 122
 123         unsigned int num_counters;
 124
 125         /* The counters (actually `number' of these). */
 126         struct xt_counters counters[0];
 127 };
 128
 129 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 130
 131 /* fn returns 0 to continue iteration */
 132 #define XT_MATCH_ITERATE(type, e, fn, args...)                  \
 133 ({                                                              \
 134         unsigned int __i;                                       \
 135         int __ret = 0;                                          \
 136         struct xt_entry_match *__m;                             \
 137                                                                 \
 138         for (__i = sizeof(type);                                \
 139              __i < (e)->target_offset;                          \
 140              __i += __m->u.match_size) {                        \
 141                 __m = (void *)e + __i;                          \
 142                                                                 \
 143                 __ret = fn(__m , ## args);                      \
 144                 if (__ret != 0)                                 \
 145                         break;                                  \
 146         }                                                       \
 147         __ret;                                                  \
 148 })
 149
 150 /* fn returns 0 to continue iteration */
 151 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
 152 ({                                                              \
 153         unsigned int __i, __n;                                  \
 154         int __ret = 0;                                          \
 155         type *__entry;                                          \
 156                                                                 \
 157         for (__i = 0, __n = 0; __i < (size);                    \
 158              __i += __entry->next_offset, __n++) {              \
 159                 __entry = (void *)(entries) + __i;              \
 160                 if (__n < n)                                    \
 161                         continue;                               \
 162                                                                 \
 163                 __ret = fn(__entry , ## args);                  \
 164                 if (__ret != 0)                                 \
 165                         break;                                  \
 166         }                                                       \
 167         __ret;                                                  \
 168 })
 169
 170 /* fn returns 0 to continue iteration */
 171 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
 172         XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
 173
 174 #ifdef __KERNEL__
 175
 176 #include <linux/netdevice.h>
 177
 178 /**
 179  * struct xt_match_param - parameters for match extensions' match functions
 180  *
 181  * @in:         input netdevice
 182  * @out:        output netdevice
 183  * @match:      struct xt_match through which this function was invoked
 184  * @matchinfo:  per-match data
 185  * @fragoff:    packet is a fragment, this is the data offset
 186  * @thoff:      position of transport header relative to skb->data
 187  * @hotdrop:    drop packet if we had inspection problems
 188  * @family:     Actual NFPROTO_* through which the function is invoked
 189  *              (helpful when match->family == NFPROTO_UNSPEC)
 190  */
 191 struct xt_match_param {
 192         const struct net_device *in, *out;
 193         const struct xt_match *match;
 194         const void *matchinfo;
 195         int fragoff;
 196         unsigned int thoff;
 197         bool *hotdrop;
 198         u_int8_t family;
 199 };
 200
 201 /**
 202  * struct xt_mtchk_param - parameters for match extensions'
 203  * checkentry functions
 204  *
 205  * @table:      table the rule is tried to be inserted into
 206  * @entryinfo:  the family-specific rule data
 207  *              (struct ipt_ip, ip6t_ip, ebt_entry)
 208  * @match:      struct xt_match through which this function was invoked
 209  * @matchinfo:  per-match data
 210  * @hook_mask:  via which hooks the new rule is reachable
 211  */
 212 struct xt_mtchk_param {
 213         const char *table;
 214         const void *entryinfo;
 215         const struct xt_match *match;
 216         void *matchinfo;
 217         unsigned int hook_mask;
 218         u_int8_t family;
 219 };
 220
 221 /* Match destructor parameters */
 222 struct xt_mtdtor_param {
 223         const struct xt_match *match;
 224         void *matchinfo;
 225         u_int8_t family;
 226 };
 227
 228 /**
 229  * struct xt_target_param - parameters for target extensions' target functions
 230  *
 231  * @hooknum:    hook through which this target was invoked
 232  * @target:     struct xt_target through which this function was invoked
 233  * @targinfo:   per-target data
 234  *
 235  * Other fields see above.
 236  */
 237 struct xt_target_param {
 238         const struct net_device *in, *out;
 239         unsigned int hooknum;
 240         const struct xt_target *target;
 241         const void *targinfo;
 242         u_int8_t family;
 243 };
 244
 245 /**
 246  * struct xt_tgchk_param - parameters for target extensions'
 247  * checkentry functions
 248  *
 249  * @entryinfo:  the family-specific rule data
 250  *              (struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
 251  *
 252  * Other fields see above.
 253  */
 254 struct xt_tgchk_param {
 255         const char *table;
 256         const void *entryinfo;
 257         const struct xt_target *target;
 258         void *targinfo;
 259         unsigned int hook_mask;
 260         u_int8_t family;
 261 };
 262
 263 /* Target destructor parameters */
 264 struct xt_tgdtor_param {
 265         const struct xt_target *target;
 266         void *targinfo;
 267         u_int8_t family;
 268 };
 269
 270 struct xt_match
 271 {
 272         struct list_head list;
 273
 274         const char name[XT_FUNCTION_MAXNAMELEN-1];
 275         u_int8_t revision;
 276
 277         /* Return true or false: return FALSE and set *hotdrop = 1 to
 278            force immediate packet drop. */
 279         /* Arguments changed since 2.6.9, as this must now handle
 280            non-linear skb, using skb_header_pointer and
 281            skb_ip_make_writable. */
 282         bool (*match)(const struct sk_buff *skb,
 283                       const struct xt_match_param *);
 284
 285         /* Called when user tries to insert an entry of this type. */
 286         bool (*checkentry)(const struct xt_mtchk_param *);
 287
 288         /* Called when entry of this type deleted. */
 289         void (*destroy)(const struct xt_mtdtor_param *);
 290
 291         /* Called when userspace align differs from kernel space one */
 292         void (*compat_from_user)(void *dst, void *src);
 293         int (*compat_to_user)(void __user *dst, void *src);
 294
 295         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 296         struct module *me;
 297
 298         /* Free to use by each match */
 299         unsigned long data;
 300
 301         const char *table;
 302         unsigned int matchsize;
 303         unsigned int compatsize;
 304         unsigned int hooks;
 305         unsigned short proto;
 306
 307         unsigned short family;
 308 };
 309
 310 /* Registration hooks for targets. */
 311 struct xt_target
 312 {
 313         struct list_head list;
 314
 315         const char name[XT_FUNCTION_MAXNAMELEN-1];
 316
 317         /* Returns verdict. Argument order changed since 2.6.9, as this
 318            must now handle non-linear skbs, using skb_copy_bits and
 319            skb_ip_make_writable. */
 320         unsigned int (*target)(struct sk_buff *skb,
 321                                const struct xt_target_param *);
 322
 323         /* Called when user tries to insert an entry of this type:
 324            hook_mask is a bitmask of hooks from which it can be
 325            called. */
 326         /* Should return true or false. */
 327         bool (*checkentry)(const struct xt_tgchk_param *);
 328
 329         /* Called when entry of this type deleted. */
 330         void (*destroy)(const struct xt_tgdtor_param *);
 331
 332         /* Called when userspace align differs from kernel space one */
 333         void (*compat_from_user)(void *dst, void *src);
 334         int (*compat_to_user)(void __user *dst, void *src);
 335
 336         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 337         struct module *me;
 338
 339         const char *table;
 340         unsigned int targetsize;
 341         unsigned int compatsize;
 342         unsigned int hooks;
 343         unsigned short proto;
 344
 345         unsigned short family;
 346         u_int8_t revision;
 347 };
 348
 349 /* Furniture shopping... */
 350 struct xt_table
 351 {
 352         struct list_head list;
 353
 354         /* A unique name... */
 355         const char name[XT_TABLE_MAXNAMELEN];
 356
 357         /* What hooks you will enter on */
 358         unsigned int valid_hooks;
 359
 360         /* Lock for the curtain */
 361         rwlock_t lock;
 362
 363         /* Man behind the curtain... */
 364         //struct ip6t_table_info *private;
 365         void *private;
 366
 367         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 368         struct module *me;
 369
 370         u_int8_t af;            /* address/protocol family */
 371 };
 372
 373 #include <linux/netfilter_ipv4.h>
 374
 375 /* The table itself */
 376 struct xt_table_info
 377 {
 378         /* Size per table */
 379         unsigned int size;
 380         /* Number of entries: FIXME. --RR */
 381         unsigned int number;
 382         /* Initial number of entries. Needed for module usage count */
 383         unsigned int initial_entries;
 384
 385         /* Entry points and underflows */
 386         unsigned int hook_entry[NF_INET_NUMHOOKS];
 387         unsigned int underflow[NF_INET_NUMHOOKS];
 388
 389         /* ipt_entry tables: one per CPU */
 390         /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
 391         char *entries[1];
 392 };
 393
 394 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
 395                           + nr_cpu_ids * sizeof(char *))
 396 extern int xt_register_target(struct xt_target *target);
 397 extern void xt_unregister_target(struct xt_target *target);
 398 extern int xt_register_targets(struct xt_target *target, unsigned int n);
 399 extern void xt_unregister_targets(struct xt_target *target, unsigned int n);
 400
 401 extern int xt_register_match(struct xt_match *target);
 402 extern void xt_unregister_match(struct xt_match *target);
 403 extern int xt_register_matches(struct xt_match *match, unsigned int n);
 404 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
 405
 406 extern int xt_check_match(struct xt_mtchk_param *,
 407                           unsigned int size, u_int8_t proto, bool inv_proto);
 408 extern int xt_check_target(struct xt_tgchk_param *,
 409                            unsigned int size, u_int8_t proto, bool inv_proto);
 410
 411 extern struct xt_table *xt_register_table(struct net *net,
 412                                           struct xt_table *table,
 413                                           struct xt_table_info *bootstrap,
 414                                           struct xt_table_info *newinfo);
 415 extern void *xt_unregister_table(struct xt_table *table);
 416
 417 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
 418                                               unsigned int num_counters,
 419                                               struct xt_table_info *newinfo,
 420                                               int *error);
 421
 422 extern struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
 423 extern struct xt_target *xt_find_target(u8 af, const char *name, u8 revision);
 424 extern struct xt_target *xt_request_find_target(u8 af, const char *name,
 425                                                 u8 revision);
 426 extern int xt_find_revision(u8 af, const char *name, u8 revision,
 427                             int target, int *err);
 428
 429 extern struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
 430                                            const char *name);
 431 extern void xt_table_unlock(struct xt_table *t);
 432
 433 extern int xt_proto_init(struct net *net, u_int8_t af);
 434 extern void xt_proto_fini(struct net *net, u_int8_t af);
 435
 436 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
 437 extern void xt_free_table_info(struct xt_table_info *info);
 438
 439 #ifdef CONFIG_COMPAT
 440 #include <net/compat.h>
 441
 442 struct compat_xt_entry_match
 443 {
 444         union {
 445                 struct {
 446                         u_int16_t match_size;
 447                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 448                         u_int8_t revision;
 449                 } user;
 450                 struct {
 451                         u_int16_t match_size;
 452                         compat_uptr_t match;
 453                 } kernel;
 454                 u_int16_t match_size;
 455         } u;
 456         unsigned char data[0];
 457 };
 458
 459 struct compat_xt_entry_target
 460 {
 461         union {
 462                 struct {
 463                         u_int16_t target_size;
 464                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 465                         u_int8_t revision;
 466                 } user;
 467                 struct {
 468                         u_int16_t target_size;
 469                         compat_uptr_t target;
 470                 } kernel;
 471                 u_int16_t target_size;
 472         } u;
 473         unsigned char data[0];
 474 };
 475
 476 /* FIXME: this works only on 32 bit tasks
 477  * need to change whole approach in order to calculate align as function of
 478  * current task alignment */
 479
 480 struct compat_xt_counters
 481 {
 482 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
 483         u_int32_t cnt[4];
 484 #else
 485         u_int64_t cnt[2];
 486 #endif
 487 };
 488
 489 struct compat_xt_counters_info
 490 {
 491         char name[XT_TABLE_MAXNAMELEN];
 492         compat_uint_t num_counters;
 493         struct compat_xt_counters counters[0];
 494 };
 495
 496 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
 497                 & ~(__alignof__(struct compat_xt_counters)-1))
 498
 499 extern void xt_compat_lock(u_int8_t af);
 500 extern void xt_compat_unlock(u_int8_t af);
 501
 502 extern int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta);
 503 extern void xt_compat_flush_offsets(u_int8_t af);
 504 extern short xt_compat_calc_jump(u_int8_t af, unsigned int offset);
 505
 506 extern int xt_compat_match_offset(const struct xt_match *match);
 507 extern int xt_compat_match_from_user(struct xt_entry_match *m,
 508                                      void **dstptr, unsigned int *size);
 509 extern int xt_compat_match_to_user(struct xt_entry_match *m,
 510                                    void __user **dstptr, unsigned int *size);
 511
 512 extern int xt_compat_target_offset(const struct xt_target *target);
 513 extern void xt_compat_target_from_user(struct xt_entry_target *t,
 514                                        void **dstptr, unsigned int *size);
 515 extern int xt_compat_target_to_user(struct xt_entry_target *t,
 516                                     void __user **dstptr, unsigned int *size);
 517
 518 #endif /* CONFIG_COMPAT */
 519 #endif /* __KERNEL__ */
 520
 521 #endif /* _X_TABLES_H */