include/linux/netfilter_ipv6/ip6_tables.h

   1 /*
   2  * 25-Jul-1998 Major changes to allow for ip chain table
   3  *
   4  * 3-Jan-2000 Named tables to allow packet selection for different uses.
   5  */
   6
   7 /*
   8  *      Format of an IP6 firewall descriptor
   9  *
  10  *      src, dst, src_mask, dst_mask are always stored in network byte order.
  11  *      flags are stored in host byte order (of course).
  12  *      Port numbers are stored in HOST byte order.
  13  */
  14
  15 #ifndef _IP6_TABLES_H
  16 #define _IP6_TABLES_H
  17
  18 #ifdef __KERNEL__
  19 #include <linux/if.h>
  20 #include <linux/types.h>
  21 #include <linux/in6.h>
  22 #include <linux/ipv6.h>
  23 #include <linux/skbuff.h>
  24 #endif
  25 #include <linux/compiler.h>
  26 #include <linux/netfilter_ipv6.h>
  27
  28 #define IP6T_FUNCTION_MAXNAMELEN 30
  29 #define IP6T_TABLE_MAXNAMELEN 32
  30
  31 /* Yes, Virginia, you have to zero the padding. */
  32 struct ip6t_ip6 {
  33         /* Source and destination IP6 addr */
  34         struct in6_addr src, dst;
  35         /* Mask for src and dest IP6 addr */
  36         struct in6_addr smsk, dmsk;
  37         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  38         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  39
  40         /* ARGH, HopByHop uses 0, so can't do 0 = ANY,
  41            instead IP6T_F_NOPROTO must be set */
  42         u_int16_t proto;
  43         /* TOS to match iff flags & IP6T_F_TOS */
  44         u_int8_t tos;
  45
  46         /* Flags word */
  47         u_int8_t flags;
  48         /* Inverse flags */
  49         u_int8_t invflags;
  50 };
  51
  52 /* FIXME: If alignment in kernel different from userspace? --RR */
  53 struct ip6t_entry_match
  54 {
  55         union {
  56                 struct {
  57                         u_int16_t match_size;
  58
  59                         /* Used by userspace */
  60                         char name[IP6T_FUNCTION_MAXNAMELEN];
  61                 } user;
  62                 struct {
  63                         u_int16_t match_size;
  64
  65                         /* Used inside the kernel */
  66                         struct ip6t_match *match;
  67                 } kernel;
  68
  69                 /* Total length */
  70                 u_int16_t match_size;
  71         } u;
  72
  73         unsigned char data[0];
  74 };
  75
  76 struct ip6t_entry_target
  77 {
  78         union {
  79                 struct {
  80                         u_int16_t target_size;
  81
  82                         /* Used by userspace */
  83                         char name[IP6T_FUNCTION_MAXNAMELEN];
  84                 } user;
  85                 struct {
  86                         u_int16_t target_size;
  87
  88                         /* Used inside the kernel */
  89                         struct ip6t_target *target;
  90                 } kernel;
  91
  92                 /* Total length */
  93                 u_int16_t target_size;
  94         } u;
  95
  96         unsigned char data[0];
  97 };
  98
  99 struct ip6t_standard_target
 100 {
 101         struct ip6t_entry_target target;
 102         int verdict;
 103 };
 104
 105 struct ip6t_counters
 106 {
 107         u_int64_t pcnt, bcnt;                   /* Packet and byte counters */
 108 };
 109
 110 /* Values for "flag" field in struct ip6t_ip6 (general ip6 structure). */
 111 #define IP6T_F_PROTO            0x01    /* Set if rule cares about upper
 112                                            protocols */
 113 #define IP6T_F_TOS              0x02    /* Match the TOS. */
 114 #define IP6T_F_MASK             0x03    /* All possible flag bits mask. */
 115
 116 /* Values for "inv" field in struct ip6t_ip6. */
 117 #define IP6T_INV_VIA_IN         0x01    /* Invert the sense of IN IFACE. */
 118 #define IP6T_INV_VIA_OUT                0x02    /* Invert the sense of OUT IFACE */
 119 #define IP6T_INV_TOS            0x04    /* Invert the sense of TOS. */
 120 #define IP6T_INV_SRCIP          0x08    /* Invert the sense of SRC IP. */
 121 #define IP6T_INV_DSTIP          0x10    /* Invert the sense of DST OP. */
 122 #define IP6T_INV_FRAG           0x20    /* Invert the sense of FRAG. */
 123 #define IP6T_INV_PROTO          0x40    /* Invert the sense of PROTO. */
 124 #define IP6T_INV_MASK           0x7F    /* All possible flag bits mask. */
 125
 126 /* This structure defines each of the firewall rules.  Consists of 3
 127    parts which are 1) general IP header stuff 2) match specific
 128    stuff 3) the target to perform if the rule matches */
 129 struct ip6t_entry
 130 {
 131         struct ip6t_ip6 ipv6;
 132
 133         /* Mark with fields that we care about. */
 134         unsigned int nfcache;
 135
 136         /* Size of ipt_entry + matches */
 137         u_int16_t target_offset;
 138         /* Size of ipt_entry + matches + target */
 139         u_int16_t next_offset;
 140
 141         /* Back pointer */
 142         unsigned int comefrom;
 143
 144         /* Packet and byte counters. */
 145         struct ip6t_counters counters;
 146
 147         /* The matches (if any), then the target. */
 148         unsigned char elems[0];
 149 };
 150
 151 /*
 152  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 153  * Unlike BSD Linux inherits IP options so you don't have to use
 154  * a raw socket for this. Instead we check rights in the calls. */
 155 #define IP6T_BASE_CTL                   64      /* base for firewall socket options */
 156
 157 #define IP6T_SO_SET_REPLACE             (IP6T_BASE_CTL)
 158 #define IP6T_SO_SET_ADD_COUNTERS        (IP6T_BASE_CTL + 1)
 159 #define IP6T_SO_SET_MAX                 IP6T_SO_SET_ADD_COUNTERS
 160
 161 #define IP6T_SO_GET_INFO                (IP6T_BASE_CTL)
 162 #define IP6T_SO_GET_ENTRIES             (IP6T_BASE_CTL + 1)
 163 #define IP6T_SO_GET_MAX                 IP6T_SO_GET_ENTRIES
 164
 165 /* CONTINUE verdict for targets */
 166 #define IP6T_CONTINUE 0xFFFFFFFF
 167
 168 /* For standard target */
 169 #define IP6T_RETURN (-NF_REPEAT - 1)
 170
 171 /* TCP matching stuff */
 172 struct ip6t_tcp
 173 {
 174         u_int16_t spts[2];                      /* Source port range. */
 175         u_int16_t dpts[2];                      /* Destination port range. */
 176         u_int8_t option;                        /* TCP Option iff non-zero*/
 177         u_int8_t flg_mask;                      /* TCP flags mask byte */
 178         u_int8_t flg_cmp;                       /* TCP flags compare byte */
 179         u_int8_t invflags;                      /* Inverse flags */
 180 };
 181
 182 /* Values for "inv" field in struct ipt_tcp. */
 183 #define IP6T_TCP_INV_SRCPT      0x01    /* Invert the sense of source ports. */
 184 #define IP6T_TCP_INV_DSTPT      0x02    /* Invert the sense of dest ports. */
 185 #define IP6T_TCP_INV_FLAGS      0x04    /* Invert the sense of TCP flags. */
 186 #define IP6T_TCP_INV_OPTION     0x08    /* Invert the sense of option test. */
 187 #define IP6T_TCP_INV_MASK       0x0F    /* All possible flags. */
 188
 189 /* UDP matching stuff */
 190 struct ip6t_udp
 191 {
 192         u_int16_t spts[2];                      /* Source port range. */
 193         u_int16_t dpts[2];                      /* Destination port range. */
 194         u_int8_t invflags;                      /* Inverse flags */
 195 };
 196
 197 /* Values for "invflags" field in struct ipt_udp. */
 198 #define IP6T_UDP_INV_SRCPT      0x01    /* Invert the sense of source ports. */
 199 #define IP6T_UDP_INV_DSTPT      0x02    /* Invert the sense of dest ports. */
 200 #define IP6T_UDP_INV_MASK       0x03    /* All possible flags. */
 201
 202 /* ICMP matching stuff */
 203 struct ip6t_icmp
 204 {
 205         u_int8_t type;                          /* type to match */
 206         u_int8_t code[2];                       /* range of code */
 207         u_int8_t invflags;                      /* Inverse flags */
 208 };
 209
 210 /* Values for "inv" field for struct ipt_icmp. */
 211 #define IP6T_ICMP_INV   0x01    /* Invert the sense of type/code test */
 212
 213 /* The argument to IP6T_SO_GET_INFO */
 214 struct ip6t_getinfo
 215 {
 216         /* Which table: caller fills this in. */
 217         char name[IP6T_TABLE_MAXNAMELEN];
 218
 219         /* Kernel fills these in. */
 220         /* Which hook entry points are valid: bitmask */
 221         unsigned int valid_hooks;
 222
 223         /* Hook entry points: one per netfilter hook. */
 224         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 225
 226         /* Underflow points. */
 227         unsigned int underflow[NF_IP6_NUMHOOKS];
 228
 229         /* Number of entries */
 230         unsigned int num_entries;
 231
 232         /* Size of entries. */
 233         unsigned int size;
 234 };
 235
 236 /* The argument to IP6T_SO_SET_REPLACE. */
 237 struct ip6t_replace
 238 {
 239         /* Which table. */
 240         char name[IP6T_TABLE_MAXNAMELEN];
 241
 242         /* Which hook entry points are valid: bitmask.  You can't
 243            change this. */
 244         unsigned int valid_hooks;
 245
 246         /* Number of entries */
 247         unsigned int num_entries;
 248
 249         /* Total size of new entries */
 250         unsigned int size;
 251
 252         /* Hook entry points. */
 253         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 254
 255         /* Underflow points. */
 256         unsigned int underflow[NF_IP6_NUMHOOKS];
 257
 258         /* Information about old entries: */
 259         /* Number of counters (must be equal to current number of entries). */
 260         unsigned int num_counters;
 261         /* The old entries' counters. */
 262         struct ip6t_counters __user *counters;
 263
 264         /* The entries (hang off end: not really an array). */
 265         struct ip6t_entry entries[0];
 266 };
 267
 268 /* The argument to IP6T_SO_ADD_COUNTERS. */
 269 struct ip6t_counters_info
 270 {
 271         /* Which table. */
 272         char name[IP6T_TABLE_MAXNAMELEN];
 273
 274         unsigned int num_counters;
 275
 276         /* The counters (actually `number' of these). */
 277         struct ip6t_counters counters[0];
 278 };
 279
 280 /* The argument to IP6T_SO_GET_ENTRIES. */
 281 struct ip6t_get_entries
 282 {
 283         /* Which table: user fills this in. */
 284         char name[IP6T_TABLE_MAXNAMELEN];
 285
 286         /* User fills this in: total entry size. */
 287         unsigned int size;
 288
 289         /* The entries. */
 290         struct ip6t_entry entrytable[0];
 291 };
 292
 293 /* Standard return verdict, or do jump. */
 294 #define IP6T_STANDARD_TARGET ""
 295 /* Error verdict. */
 296 #define IP6T_ERROR_TARGET "ERROR"
 297
 298 /* Helper functions */
 299 static __inline__ struct ip6t_entry_target *
 300 ip6t_get_target(struct ip6t_entry *e)
 301 {
 302         return (void *)e + e->target_offset;
 303 }
 304
 305 /* fn returns 0 to continue iteration */
 306 #define IP6T_MATCH_ITERATE(e, fn, args...)      \
 307 ({                                              \
 308         unsigned int __i;                       \
 309         int __ret = 0;                          \
 310         struct ip6t_entry_match *__m;           \
 311                                                 \
 312         for (__i = sizeof(struct ip6t_entry);   \
 313              __i < (e)->target_offset;          \
 314              __i += __m->u.match_size) {        \
 315                 __m = (void *)(e) + __i;        \
 316                                                 \
 317                 __ret = fn(__m , ## args);      \
 318                 if (__ret != 0)                 \
 319                         break;                  \
 320         }                                       \
 321         __ret;                                  \
 322 })
 323
 324 /* fn returns 0 to continue iteration */
 325 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...)          \
 326 ({                                                              \
 327         unsigned int __i;                                       \
 328         int __ret = 0;                                          \
 329         struct ip6t_entry *__e;                                 \
 330                                                                 \
 331         for (__i = 0; __i < (size); __i += __e->next_offset) {  \
 332                 __e = (void *)(entries) + __i;                  \
 333                                                                 \
 334                 __ret = fn(__e , ## args);                      \
 335                 if (__ret != 0)                                 \
 336                         break;                                  \
 337         }                                                       \
 338         __ret;                                                  \
 339 })
 340
 341 /*
 342  *      Main firewall chains definitions and global var's definitions.
 343  */
 344
 345 #ifdef __KERNEL__
 346
 347 #include <linux/init.h>
 348 extern void ip6t_init(void) __init;
 349
 350 struct ip6t_match
 351 {
 352         struct list_head list;
 353
 354         const char name[IP6T_FUNCTION_MAXNAMELEN];
 355
 356         /* Return true or false: return FALSE and set *hotdrop = 1 to
 357            force immediate packet drop. */
 358         /* Arguments changed since 2.6.9, as this must now handle
 359            non-linear skb, using skb_header_pointer and
 360            skb_ip_make_writable. */
 361         int (*match)(const struct sk_buff *skb,
 362                      const struct net_device *in,
 363                      const struct net_device *out,
 364                      const void *matchinfo,
 365                      int offset,
 366                      unsigned int protoff,
 367                      int *hotdrop);
 368
 369         /* Called when user tries to insert an entry of this type. */
 370         /* Should return true or false. */
 371         int (*checkentry)(const char *tablename,
 372                           const struct ip6t_ip6 *ip,
 373                           void *matchinfo,
 374                           unsigned int matchinfosize,
 375                           unsigned int hook_mask);
 376
 377         /* Called when entry of this type deleted. */
 378         void (*destroy)(void *matchinfo, unsigned int matchinfosize);
 379
 380         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 381         struct module *me;
 382 };
 383
 384 /* Registration hooks for targets. */
 385 struct ip6t_target
 386 {
 387         struct list_head list;
 388
 389         const char name[IP6T_FUNCTION_MAXNAMELEN];
 390
 391         /* Returns verdict. Argument order changed since 2.6.9, as this
 392            must now handle non-linear skbs, using skb_copy_bits and
 393            skb_ip_make_writable. */
 394         unsigned int (*target)(struct sk_buff **pskb,
 395                                const struct net_device *in,
 396                                const struct net_device *out,
 397                                unsigned int hooknum,
 398                                const void *targinfo,
 399                                void *userdata);
 400
 401         /* Called when user tries to insert an entry of this type:
 402            hook_mask is a bitmask of hooks from which it can be
 403            called. */
 404         /* Should return true or false. */
 405         int (*checkentry)(const char *tablename,
 406                           const struct ip6t_entry *e,
 407                           void *targinfo,
 408                           unsigned int targinfosize,
 409                           unsigned int hook_mask);
 410
 411         /* Called when entry of this type deleted. */
 412         void (*destroy)(void *targinfo, unsigned int targinfosize);
 413
 414         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 415         struct module *me;
 416 };
 417
 418 extern int ip6t_register_target(struct ip6t_target *target);
 419 extern void ip6t_unregister_target(struct ip6t_target *target);
 420
 421 extern int ip6t_register_match(struct ip6t_match *match);
 422 extern void ip6t_unregister_match(struct ip6t_match *match);
 423
 424 /* Furniture shopping... */
 425 struct ip6t_table
 426 {
 427         struct list_head list;
 428
 429         /* A unique name... */
 430         char name[IP6T_TABLE_MAXNAMELEN];
 431
 432         /* What hooks you will enter on */
 433         unsigned int valid_hooks;
 434
 435         /* Lock for the curtain */
 436         rwlock_t lock;
 437
 438         /* Man behind the curtain... */
 439         struct ip6t_table_info *private;
 440
 441         /* Set this to THIS_MODULE if you are a module, otherwise NULL */
 442         struct module *me;
 443 };
 444
 445 extern int ip6t_register_table(struct ip6t_table *table,
 446                                const struct ip6t_replace *repl);
 447 extern void ip6t_unregister_table(struct ip6t_table *table);
 448 extern unsigned int ip6t_do_table(struct sk_buff **pskb,
 449                                   unsigned int hook,
 450                                   const struct net_device *in,
 451                                   const struct net_device *out,
 452                                   struct ip6t_table *table,
 453                                   void *userdata);
 454
 455 /* Check for an extension */
 456 extern int ip6t_ext_hdr(u8 nexthdr);
 457
 458 #define IP6T_ALIGN(s) (((s) + (__alignof__(struct ip6t_entry)-1)) & ~(__alignof__(struct ip6t_entry)-1))
 459
 460 #endif /*__KERNEL__*/
 461 #endif /* _IP6_TABLES_H */