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 #define ASSERT_READ_LOCK(x)
 142 #define ASSERT_WRITE_LOCK(x)
 143 #include <linux/netfilter_ipv4/listhelp.h>
 144
 145 #ifdef CONFIG_COMPAT
 146 #define COMPAT_TO_USER          1
 147 #define COMPAT_FROM_USER        -1
 148 #define COMPAT_CALC_SIZE        0
 149 #endif
 150
 151 struct xt_match
 152 {
 153         struct list_head list;
 154
 155         const char name[XT_FUNCTION_MAXNAMELEN-1];
 156
 157         /* Return true or false: return FALSE and set *hotdrop = 1 to
 158            force immediate packet drop. */
 159         /* Arguments changed since 2.6.9, as this must now handle
 160            non-linear skb, using skb_header_pointer and
 161            skb_ip_make_writable. */
 162         int (*match)(const struct sk_buff *skb,
 163                      const struct net_device *in,
 164                      const struct net_device *out,
 165                      const struct xt_match *match,
 166                      const void *matchinfo,
 167                      int offset,
 168                      unsigned int protoff,
 169                      int *hotdrop);
 170
 171         /* Called when user tries to insert an entry of this type. */
 172         /* Should return true or false. */
 173         int (*checkentry)(const char *tablename,
 174                           const void *ip,
 175                           const struct xt_match *match,
 176                           void *matchinfo,
 177                           unsigned int matchinfosize,
 178                           unsigned int hook_mask);
 179
 180         /* Called when entry of this type deleted. */
 181         void (*destroy)(const struct xt_match *match, void *matchinfo,
 182                         unsigned int matchinfosize);
 183
 184         /* Called when userspace align differs from kernel space one */
 185         int (*compat)(void *match, void **dstptr, int *size, int convert);
 186
 187         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 188         struct module *me;
 189
 190         char *table;
 191         unsigned int matchsize;
 192         unsigned int hooks;
 193         unsigned short proto;
 194
 195         unsigned short family;
 196         u_int8_t revision;
 197 };
 198
 199 /* Registration hooks for targets. */
 200 struct xt_target
 201 {
 202         struct list_head list;
 203
 204         const char name[XT_FUNCTION_MAXNAMELEN-1];
 205
 206         /* Returns verdict. Argument order changed since 2.6.9, as this
 207            must now handle non-linear skbs, using skb_copy_bits and
 208            skb_ip_make_writable. */
 209         unsigned int (*target)(struct sk_buff **pskb,
 210                                const struct net_device *in,
 211                                const struct net_device *out,
 212                                unsigned int hooknum,
 213                                const struct xt_target *target,
 214                                const void *targinfo,
 215                                void *userdata);
 216
 217         /* Called when user tries to insert an entry of this type:
 218            hook_mask is a bitmask of hooks from which it can be
 219            called. */
 220         /* Should return true or false. */
 221         int (*checkentry)(const char *tablename,
 222                           const void *entry,
 223                           const struct xt_target *target,
 224                           void *targinfo,
 225                           unsigned int targinfosize,
 226                           unsigned int hook_mask);
 227
 228         /* Called when entry of this type deleted. */
 229         void (*destroy)(const struct xt_target *target, void *targinfo,
 230                         unsigned int targinfosize);
 231
 232         /* Called when userspace align differs from kernel space one */
 233         int (*compat)(void *target, void **dstptr, int *size, int convert);
 234
 235         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 236         struct module *me;
 237
 238         char *table;
 239         unsigned int targetsize;
 240         unsigned int hooks;
 241         unsigned short proto;
 242
 243         unsigned short family;
 244         u_int8_t revision;
 245 };
 246
 247 /* Furniture shopping... */
 248 struct xt_table
 249 {
 250         struct list_head list;
 251
 252         /* A unique name... */
 253         char name[XT_TABLE_MAXNAMELEN];
 254
 255         /* What hooks you will enter on */
 256         unsigned int valid_hooks;
 257
 258         /* Lock for the curtain */
 259         rwlock_t lock;
 260
 261         /* Man behind the curtain... */
 262         //struct ip6t_table_info *private;
 263         void *private;
 264
 265         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 266         struct module *me;
 267
 268         int af;         /* address/protocol family */
 269 };
 270
 271 #include <linux/netfilter_ipv4.h>
 272
 273 /* The table itself */
 274 struct xt_table_info
 275 {
 276         /* Size per table */
 277         unsigned int size;
 278         /* Number of entries: FIXME. --RR */
 279         unsigned int number;
 280         /* Initial number of entries. Needed for module usage count */
 281         unsigned int initial_entries;
 282
 283         /* Entry points and underflows */
 284         unsigned int hook_entry[NF_IP_NUMHOOKS];
 285         unsigned int underflow[NF_IP_NUMHOOKS];
 286
 287         /* ipt_entry tables: one per CPU */
 288         char *entries[NR_CPUS];
 289 };
 290
 291 extern int xt_register_target(struct xt_target *target);
 292 extern void xt_unregister_target(struct xt_target *target);
 293 extern int xt_register_match(struct xt_match *target);
 294 extern void xt_unregister_match(struct xt_match *target);
 295
 296 extern int xt_check_match(const struct xt_match *match, unsigned short family,
 297                           unsigned int size, const char *table, unsigned int hook,
 298                           unsigned short proto, int inv_proto);
 299 extern int xt_check_target(const struct xt_target *target, unsigned short family,
 300                            unsigned int size, const char *table, unsigned int hook,
 301                            unsigned short proto, int inv_proto);
 302
 303 extern int xt_register_table(struct xt_table *table,
 304                              struct xt_table_info *bootstrap,
 305                              struct xt_table_info *newinfo);
 306 extern void *xt_unregister_table(struct xt_table *table);
 307
 308 extern struct xt_table_info *xt_replace_table(struct xt_table *table,
 309                                               unsigned int num_counters,
 310                                               struct xt_table_info *newinfo,
 311                                               int *error);
 312
 313 extern struct xt_match *xt_find_match(int af, const char *name, u8 revision);
 314 extern struct xt_target *xt_find_target(int af, const char *name, u8 revision);
 315 extern struct xt_target *xt_request_find_target(int af, const char *name,
 316                                                 u8 revision);
 317 extern int xt_find_revision(int af, const char *name, u8 revision, int target,
 318                             int *err);
 319
 320 extern struct xt_table *xt_find_table_lock(int af, const char *name);
 321 extern void xt_table_unlock(struct xt_table *t);
 322
 323 extern int xt_proto_init(int af);
 324 extern void xt_proto_fini(int af);
 325
 326 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
 327 extern void xt_free_table_info(struct xt_table_info *info);
 328
 329 #ifdef CONFIG_COMPAT
 330 #include <net/compat.h>
 331
 332 struct compat_xt_entry_match
 333 {
 334         union {
 335                 struct {
 336                         u_int16_t match_size;
 337                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 338                         u_int8_t revision;
 339                 } user;
 340                 u_int16_t match_size;
 341         } u;
 342         unsigned char data[0];
 343 };
 344
 345 struct compat_xt_entry_target
 346 {
 347         union {
 348                 struct {
 349                         u_int16_t target_size;
 350                         char name[XT_FUNCTION_MAXNAMELEN - 1];
 351                         u_int8_t revision;
 352                 } user;
 353                 u_int16_t target_size;
 354         } u;
 355         unsigned char data[0];
 356 };
 357
 358 /* FIXME: this works only on 32 bit tasks
 359  * need to change whole approach in order to calculate align as function of
 360  * current task alignment */
 361
 362 struct compat_xt_counters
 363 {
 364         u_int32_t cnt[4];
 365 };
 366
 367 struct compat_xt_counters_info
 368 {
 369         char name[XT_TABLE_MAXNAMELEN];
 370         compat_uint_t num_counters;
 371         struct compat_xt_counters counters[0];
 372 };
 373
 374 #define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
 375                 & ~(__alignof__(struct compat_xt_counters)-1))
 376
 377 extern void xt_compat_lock(int af);
 378 extern void xt_compat_unlock(int af);
 379 extern int xt_compat_match(void *match, void **dstptr, int *size, int convert);
 380 extern int xt_compat_target(void *target, void **dstptr, int *size,
 381                 int convert);
 382
 383 #endif /* CONFIG_COMPAT */
 384 #endif /* __KERNEL__ */
 385
 386 #endif /* _X_TABLES_H */