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 #include <linux/netfilter/x_tables.h>
  29
  30 #define IP6T_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  31 #define IP6T_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
  32
  33 #define ip6t_match xt_match
  34 #define ip6t_target xt_target
  35 #define ip6t_table xt_table
  36 #define ip6t_get_revision xt_get_revision
  37
  38 /* Yes, Virginia, you have to zero the padding. */
  39 struct ip6t_ip6 {
  40         /* Source and destination IP6 addr */
  41         struct in6_addr src, dst;
  42         /* Mask for src and dest IP6 addr */
  43         struct in6_addr smsk, dmsk;
  44         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  45         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  46
  47         /* Upper protocol number
  48          * - The allowed value is 0 (any) or protocol number of last parsable
  49          *   header, which is 50 (ESP), 59 (No Next Header), 135 (MH), or
  50          *   the non IPv6 extension headers.
  51          * - The protocol numbers of IPv6 extension headers except of ESP and
  52          *   MH do not match any packets.
  53          * - You also need to set IP6T_FLAGS_PROTO to "flags" to check protocol.
  54          */
  55         u_int16_t proto;
  56         /* TOS to match iff flags & IP6T_F_TOS */
  57         u_int8_t tos;
  58
  59         /* Flags word */
  60         u_int8_t flags;
  61         /* Inverse flags */
  62         u_int8_t invflags;
  63 };
  64
  65 #define ip6t_entry_match xt_entry_match
  66 #define ip6t_entry_target xt_entry_target
  67 #define ip6t_standard_target xt_standard_target
  68
  69 #define ip6t_counters   xt_counters
  70
  71 /* Values for "flag" field in struct ip6t_ip6 (general ip6 structure). */
  72 #define IP6T_F_PROTO            0x01    /* Set if rule cares about upper
  73                                            protocols */
  74 #define IP6T_F_TOS              0x02    /* Match the TOS. */
  75 #define IP6T_F_GOTO             0x04    /* Set if jump is a goto */
  76 #define IP6T_F_MASK             0x07    /* All possible flag bits mask. */
  77
  78 /* Values for "inv" field in struct ip6t_ip6. */
  79 #define IP6T_INV_VIA_IN         0x01    /* Invert the sense of IN IFACE. */
  80 #define IP6T_INV_VIA_OUT                0x02    /* Invert the sense of OUT IFACE */
  81 #define IP6T_INV_TOS            0x04    /* Invert the sense of TOS. */
  82 #define IP6T_INV_SRCIP          0x08    /* Invert the sense of SRC IP. */
  83 #define IP6T_INV_DSTIP          0x10    /* Invert the sense of DST OP. */
  84 #define IP6T_INV_FRAG           0x20    /* Invert the sense of FRAG. */
  85 #define IP6T_INV_PROTO          XT_INV_PROTO
  86 #define IP6T_INV_MASK           0x7F    /* All possible flag bits mask. */
  87
  88 /* This structure defines each of the firewall rules.  Consists of 3
  89    parts which are 1) general IP header stuff 2) match specific
  90    stuff 3) the target to perform if the rule matches */
  91 struct ip6t_entry
  92 {
  93         struct ip6t_ip6 ipv6;
  94
  95         /* Mark with fields that we care about. */
  96         unsigned int nfcache;
  97
  98         /* Size of ipt_entry + matches */
  99         u_int16_t target_offset;
 100         /* Size of ipt_entry + matches + target */
 101         u_int16_t next_offset;
 102
 103         /* Back pointer */
 104         unsigned int comefrom;
 105
 106         /* Packet and byte counters. */
 107         struct xt_counters counters;
 108
 109         /* The matches (if any), then the target. */
 110         unsigned char elems[0];
 111 };
 112
 113 /* Standard entry */
 114 struct ip6t_standard
 115 {
 116         struct ip6t_entry entry;
 117         struct ip6t_standard_target target;
 118 };
 119
 120 struct ip6t_error_target
 121 {
 122         struct ip6t_entry_target target;
 123         char errorname[IP6T_FUNCTION_MAXNAMELEN];
 124 };
 125
 126 struct ip6t_error
 127 {
 128         struct ip6t_entry entry;
 129         struct ip6t_error_target target;
 130 };
 131
 132 #define IP6T_ENTRY_INIT(__size)                                                \
 133 {                                                                              \
 134         .target_offset  = sizeof(struct ip6t_entry),                           \
 135         .next_offset    = (__size),                                            \
 136 }
 137
 138 #define IP6T_STANDARD_INIT(__verdict)                                          \
 139 {                                                                              \
 140         .entry          = IP6T_ENTRY_INIT(sizeof(struct ip6t_standard)),       \
 141         .target         = XT_TARGET_INIT(IP6T_STANDARD_TARGET,                 \
 142                                          sizeof(struct ip6t_standard_target)), \
 143         .target.verdict = -(__verdict) - 1,                                    \
 144 }
 145
 146 #define IP6T_ERROR_INIT                                                        \
 147 {                                                                              \
 148         .entry          = IP6T_ENTRY_INIT(sizeof(struct ip6t_error)),          \
 149         .target         = XT_TARGET_INIT(IP6T_ERROR_TARGET,                    \
 150                                          sizeof(struct ip6t_error_target)),    \
 151         .target.errorname = "ERROR",                                           \
 152 }
 153
 154 /*
 155  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 156  * Unlike BSD Linux inherits IP options so you don't have to use
 157  * a raw socket for this. Instead we check rights in the calls.
 158  *
 159  * ATTENTION: check linux/in6.h before adding new number here.
 160  */
 161 #define IP6T_BASE_CTL                   64
 162
 163 #define IP6T_SO_SET_REPLACE             (IP6T_BASE_CTL)
 164 #define IP6T_SO_SET_ADD_COUNTERS        (IP6T_BASE_CTL + 1)
 165 #define IP6T_SO_SET_MAX                 IP6T_SO_SET_ADD_COUNTERS
 166
 167 #define IP6T_SO_GET_INFO                (IP6T_BASE_CTL)
 168 #define IP6T_SO_GET_ENTRIES             (IP6T_BASE_CTL + 1)
 169 #define IP6T_SO_GET_REVISION_MATCH      (IP6T_BASE_CTL + 4)
 170 #define IP6T_SO_GET_REVISION_TARGET     (IP6T_BASE_CTL + 5)
 171 #define IP6T_SO_GET_MAX                 IP6T_SO_GET_REVISION_TARGET
 172
 173 /* CONTINUE verdict for targets */
 174 #define IP6T_CONTINUE XT_CONTINUE
 175
 176 /* For standard target */
 177 #define IP6T_RETURN XT_RETURN
 178
 179 /* TCP/UDP matching stuff */
 180 #include <linux/netfilter/xt_tcpudp.h>
 181
 182 #define ip6t_tcp xt_tcp
 183 #define ip6t_udp xt_udp
 184
 185 /* Values for "inv" field in struct ipt_tcp. */
 186 #define IP6T_TCP_INV_SRCPT      XT_TCP_INV_SRCPT
 187 #define IP6T_TCP_INV_DSTPT      XT_TCP_INV_DSTPT
 188 #define IP6T_TCP_INV_FLAGS      XT_TCP_INV_FLAGS
 189 #define IP6T_TCP_INV_OPTION     XT_TCP_INV_OPTION
 190 #define IP6T_TCP_INV_MASK       XT_TCP_INV_MASK
 191
 192 /* Values for "invflags" field in struct ipt_udp. */
 193 #define IP6T_UDP_INV_SRCPT      XT_UDP_INV_SRCPT
 194 #define IP6T_UDP_INV_DSTPT      XT_UDP_INV_DSTPT
 195 #define IP6T_UDP_INV_MASK       XT_UDP_INV_MASK
 196
 197 /* ICMP matching stuff */
 198 struct ip6t_icmp
 199 {
 200         u_int8_t type;                          /* type to match */
 201         u_int8_t code[2];                       /* range of code */
 202         u_int8_t invflags;                      /* Inverse flags */
 203 };
 204
 205 /* Values for "inv" field for struct ipt_icmp. */
 206 #define IP6T_ICMP_INV   0x01    /* Invert the sense of type/code test */
 207
 208 /* The argument to IP6T_SO_GET_INFO */
 209 struct ip6t_getinfo
 210 {
 211         /* Which table: caller fills this in. */
 212         char name[IP6T_TABLE_MAXNAMELEN];
 213
 214         /* Kernel fills these in. */
 215         /* Which hook entry points are valid: bitmask */
 216         unsigned int valid_hooks;
 217
 218         /* Hook entry points: one per netfilter hook. */
 219         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 220
 221         /* Underflow points. */
 222         unsigned int underflow[NF_IP6_NUMHOOKS];
 223
 224         /* Number of entries */
 225         unsigned int num_entries;
 226
 227         /* Size of entries. */
 228         unsigned int size;
 229 };
 230
 231 /* The argument to IP6T_SO_SET_REPLACE. */
 232 struct ip6t_replace
 233 {
 234         /* Which table. */
 235         char name[IP6T_TABLE_MAXNAMELEN];
 236
 237         /* Which hook entry points are valid: bitmask.  You can't
 238            change this. */
 239         unsigned int valid_hooks;
 240
 241         /* Number of entries */
 242         unsigned int num_entries;
 243
 244         /* Total size of new entries */
 245         unsigned int size;
 246
 247         /* Hook entry points. */
 248         unsigned int hook_entry[NF_IP6_NUMHOOKS];
 249
 250         /* Underflow points. */
 251         unsigned int underflow[NF_IP6_NUMHOOKS];
 252
 253         /* Information about old entries: */
 254         /* Number of counters (must be equal to current number of entries). */
 255         unsigned int num_counters;
 256         /* The old entries' counters. */
 257         struct xt_counters __user *counters;
 258
 259         /* The entries (hang off end: not really an array). */
 260         struct ip6t_entry entries[0];
 261 };
 262
 263 /* The argument to IP6T_SO_ADD_COUNTERS. */
 264 #define ip6t_counters_info xt_counters_info
 265
 266 /* The argument to IP6T_SO_GET_ENTRIES. */
 267 struct ip6t_get_entries
 268 {
 269         /* Which table: user fills this in. */
 270         char name[IP6T_TABLE_MAXNAMELEN];
 271
 272         /* User fills this in: total entry size. */
 273         unsigned int size;
 274
 275         /* The entries. */
 276         struct ip6t_entry entrytable[0];
 277 };
 278
 279 /* Standard return verdict, or do jump. */
 280 #define IP6T_STANDARD_TARGET XT_STANDARD_TARGET
 281 /* Error verdict. */
 282 #define IP6T_ERROR_TARGET XT_ERROR_TARGET
 283
 284 /* Helper functions */
 285 static __inline__ struct ip6t_entry_target *
 286 ip6t_get_target(struct ip6t_entry *e)
 287 {
 288         return (void *)e + e->target_offset;
 289 }
 290
 291 /* fn returns 0 to continue iteration */
 292 #define IP6T_MATCH_ITERATE(e, fn, args...)      \
 293 ({                                              \
 294         unsigned int __i;                       \
 295         int __ret = 0;                          \
 296         struct ip6t_entry_match *__m;           \
 297                                                 \
 298         for (__i = sizeof(struct ip6t_entry);   \
 299              __i < (e)->target_offset;          \
 300              __i += __m->u.match_size) {        \
 301                 __m = (void *)(e) + __i;        \
 302                                                 \
 303                 __ret = fn(__m , ## args);      \
 304                 if (__ret != 0)                 \
 305                         break;                  \
 306         }                                       \
 307         __ret;                                  \
 308 })
 309
 310 /* fn returns 0 to continue iteration */
 311 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...)          \
 312 ({                                                              \
 313         unsigned int __i;                                       \
 314         int __ret = 0;                                          \
 315         struct ip6t_entry *__e;                                 \
 316                                                                 \
 317         for (__i = 0; __i < (size); __i += __e->next_offset) {  \
 318                 __e = (void *)(entries) + __i;                  \
 319                                                                 \
 320                 __ret = fn(__e , ## args);                      \
 321                 if (__ret != 0)                                 \
 322                         break;                                  \
 323         }                                                       \
 324         __ret;                                                  \
 325 })
 326
 327 /*
 328  *      Main firewall chains definitions and global var's definitions.
 329  */
 330
 331 #ifdef __KERNEL__
 332
 333 #include <linux/init.h>
 334 extern void ip6t_init(void) __init;
 335
 336 extern int ip6t_register_table(struct xt_table *table,
 337                                const struct ip6t_replace *repl);
 338 extern void ip6t_unregister_table(struct xt_table *table);
 339 extern unsigned int ip6t_do_table(struct sk_buff *skb,
 340                                   unsigned int hook,
 341                                   const struct net_device *in,
 342                                   const struct net_device *out,
 343                                   struct xt_table *table);
 344
 345 /* Check for an extension */
 346 extern int ip6t_ext_hdr(u8 nexthdr);
 347 /* find specified header and get offset to it */
 348 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 349                          int target, unsigned short *fragoff);
 350
 351 extern int ip6_masked_addrcmp(const struct in6_addr *addr1,
 352                               const struct in6_addr *mask,
 353                               const struct in6_addr *addr2);
 354
 355 #define IP6T_ALIGN(s) (((s) + (__alignof__(struct ip6t_entry)-1)) & ~(__alignof__(struct ip6t_entry)-1))
 356
 357 #endif /*__KERNEL__*/
 358 #endif /* _IP6_TABLES_H */