include/linux/netfilter_ipv4/ip_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 IP 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 _IPTABLES_H
  16 #define _IPTABLES_H
  17
  18 #ifdef __KERNEL__
  19 #include <linux/if.h>
  20 #include <linux/types.h>
  21 #include <linux/in.h>
  22 #include <linux/ip.h>
  23 #include <linux/skbuff.h>
  24 #endif
  25 #include <linux/compiler.h>
  26 #include <linux/netfilter_ipv4.h>
  27
  28 #include <linux/netfilter/x_tables.h>
  29
  30 #define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  31 #define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
  32 #define ipt_match xt_match
  33 #define ipt_target xt_target
  34 #define ipt_table xt_table
  35 #define ipt_get_revision xt_get_revision
  36
  37 /* Yes, Virginia, you have to zero the padding. */
  38 struct ipt_ip {
  39         /* Source and destination IP addr */
  40         struct in_addr src, dst;
  41         /* Mask for src and dest IP addr */
  42         struct in_addr smsk, dmsk;
  43         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  44         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  45
  46         /* Protocol, 0 = ANY */
  47         u_int16_t proto;
  48
  49         /* Flags word */
  50         u_int8_t flags;
  51         /* Inverse flags */
  52         u_int8_t invflags;
  53 };
  54
  55 #define ipt_entry_match xt_entry_match
  56 #define ipt_entry_target xt_entry_target
  57 #define ipt_standard_target xt_standard_target
  58
  59 #define ipt_counters xt_counters
  60
  61 /* Values for "flag" field in struct ipt_ip (general ip structure). */
  62 #define IPT_F_FRAG              0x01    /* Set if rule is a fragment rule */
  63 #define IPT_F_GOTO              0x02    /* Set if jump is a goto */
  64 #define IPT_F_MASK              0x03    /* All possible flag bits mask. */
  65
  66 /* Values for "inv" field in struct ipt_ip. */
  67 #define IPT_INV_VIA_IN          0x01    /* Invert the sense of IN IFACE. */
  68 #define IPT_INV_VIA_OUT         0x02    /* Invert the sense of OUT IFACE */
  69 #define IPT_INV_TOS             0x04    /* Invert the sense of TOS. */
  70 #define IPT_INV_SRCIP           0x08    /* Invert the sense of SRC IP. */
  71 #define IPT_INV_DSTIP           0x10    /* Invert the sense of DST OP. */
  72 #define IPT_INV_FRAG            0x20    /* Invert the sense of FRAG. */
  73 #define IPT_INV_PROTO           XT_INV_PROTO
  74 #define IPT_INV_MASK            0x7F    /* All possible flag bits mask. */
  75
  76 /* This structure defines each of the firewall rules.  Consists of 3
  77    parts which are 1) general IP header stuff 2) match specific
  78    stuff 3) the target to perform if the rule matches */
  79 struct ipt_entry
  80 {
  81         struct ipt_ip ip;
  82
  83         /* Mark with fields that we care about. */
  84         unsigned int nfcache;
  85
  86         /* Size of ipt_entry + matches */
  87         u_int16_t target_offset;
  88         /* Size of ipt_entry + matches + target */
  89         u_int16_t next_offset;
  90
  91         /* Back pointer */
  92         unsigned int comefrom;
  93
  94         /* Packet and byte counters. */
  95         struct xt_counters counters;
  96
  97         /* The matches (if any), then the target. */
  98         unsigned char elems[0];
  99 };
 100
 101 /*
 102  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 103  * Unlike BSD Linux inherits IP options so you don't have to use a raw
 104  * socket for this. Instead we check rights in the calls.
 105  *
 106  * ATTENTION: check linux/in.h before adding new number here.
 107  */
 108 #define IPT_BASE_CTL            64
 109
 110 #define IPT_SO_SET_REPLACE      (IPT_BASE_CTL)
 111 #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
 112 #define IPT_SO_SET_MAX          IPT_SO_SET_ADD_COUNTERS
 113
 114 #define IPT_SO_GET_INFO                 (IPT_BASE_CTL)
 115 #define IPT_SO_GET_ENTRIES              (IPT_BASE_CTL + 1)
 116 #define IPT_SO_GET_REVISION_MATCH       (IPT_BASE_CTL + 2)
 117 #define IPT_SO_GET_REVISION_TARGET      (IPT_BASE_CTL + 3)
 118 #define IPT_SO_GET_MAX                  IPT_SO_GET_REVISION_TARGET
 119
 120 #define IPT_CONTINUE XT_CONTINUE
 121 #define IPT_RETURN XT_RETURN
 122
 123 #include <linux/netfilter/xt_tcpudp.h>
 124 #define ipt_udp xt_udp
 125 #define ipt_tcp xt_tcp
 126
 127 #define IPT_TCP_INV_SRCPT       XT_TCP_INV_SRCPT
 128 #define IPT_TCP_INV_DSTPT       XT_TCP_INV_DSTPT
 129 #define IPT_TCP_INV_FLAGS       XT_TCP_INV_FLAGS
 130 #define IPT_TCP_INV_OPTION      XT_TCP_INV_OPTION
 131 #define IPT_TCP_INV_MASK        XT_TCP_INV_MASK
 132
 133 #define IPT_UDP_INV_SRCPT       XT_UDP_INV_SRCPT
 134 #define IPT_UDP_INV_DSTPT       XT_UDP_INV_DSTPT
 135 #define IPT_UDP_INV_MASK        XT_UDP_INV_MASK
 136
 137 /* ICMP matching stuff */
 138 struct ipt_icmp
 139 {
 140         u_int8_t type;                          /* type to match */
 141         u_int8_t code[2];                       /* range of code */
 142         u_int8_t invflags;                      /* Inverse flags */
 143 };
 144
 145 /* Values for "inv" field for struct ipt_icmp. */
 146 #define IPT_ICMP_INV    0x01    /* Invert the sense of type/code test */
 147
 148 /* The argument to IPT_SO_GET_INFO */
 149 struct ipt_getinfo
 150 {
 151         /* Which table: caller fills this in. */
 152         char name[IPT_TABLE_MAXNAMELEN];
 153
 154         /* Kernel fills these in. */
 155         /* Which hook entry points are valid: bitmask */
 156         unsigned int valid_hooks;
 157
 158         /* Hook entry points: one per netfilter hook. */
 159         unsigned int hook_entry[NF_INET_NUMHOOKS];
 160
 161         /* Underflow points. */
 162         unsigned int underflow[NF_INET_NUMHOOKS];
 163
 164         /* Number of entries */
 165         unsigned int num_entries;
 166
 167         /* Size of entries. */
 168         unsigned int size;
 169 };
 170
 171 /* The argument to IPT_SO_SET_REPLACE. */
 172 struct ipt_replace
 173 {
 174         /* Which table. */
 175         char name[IPT_TABLE_MAXNAMELEN];
 176
 177         /* Which hook entry points are valid: bitmask.  You can't
 178            change this. */
 179         unsigned int valid_hooks;
 180
 181         /* Number of entries */
 182         unsigned int num_entries;
 183
 184         /* Total size of new entries */
 185         unsigned int size;
 186
 187         /* Hook entry points. */
 188         unsigned int hook_entry[NF_INET_NUMHOOKS];
 189
 190         /* Underflow points. */
 191         unsigned int underflow[NF_INET_NUMHOOKS];
 192
 193         /* Information about old entries: */
 194         /* Number of counters (must be equal to current number of entries). */
 195         unsigned int num_counters;
 196         /* The old entries' counters. */
 197         struct xt_counters __user *counters;
 198
 199         /* The entries (hang off end: not really an array). */
 200         struct ipt_entry entries[0];
 201 };
 202
 203 /* The argument to IPT_SO_ADD_COUNTERS. */
 204 #define ipt_counters_info xt_counters_info
 205
 206 /* The argument to IPT_SO_GET_ENTRIES. */
 207 struct ipt_get_entries
 208 {
 209         /* Which table: user fills this in. */
 210         char name[IPT_TABLE_MAXNAMELEN];
 211
 212         /* User fills this in: total entry size. */
 213         unsigned int size;
 214
 215         /* The entries. */
 216         struct ipt_entry entrytable[0];
 217 };
 218
 219 /* Standard return verdict, or do jump. */
 220 #define IPT_STANDARD_TARGET XT_STANDARD_TARGET
 221 /* Error verdict. */
 222 #define IPT_ERROR_TARGET XT_ERROR_TARGET
 223
 224 /* Helper functions */
 225 static __inline__ struct ipt_entry_target *
 226 ipt_get_target(struct ipt_entry *e)
 227 {
 228         return (void *)e + e->target_offset;
 229 }
 230
 231 /* fn returns 0 to continue iteration */
 232 #define IPT_MATCH_ITERATE(e, fn, args...) \
 233         XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
 234
 235 /* fn returns 0 to continue iteration */
 236 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
 237         XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
 238
 239 /*
 240  *      Main firewall chains definitions and global var's definitions.
 241  */
 242 #ifdef __KERNEL__
 243
 244 #include <linux/init.h>
 245 extern void ipt_init(void) __init;
 246
 247 extern struct xt_table *ipt_register_table(struct net *net,
 248                                            struct xt_table *table,
 249                                            const struct ipt_replace *repl);
 250 extern void ipt_unregister_table(struct xt_table *table);
 251
 252 /* Standard entry. */
 253 struct ipt_standard
 254 {
 255         struct ipt_entry entry;
 256         struct ipt_standard_target target;
 257 };
 258
 259 struct ipt_error_target
 260 {
 261         struct ipt_entry_target target;
 262         char errorname[IPT_FUNCTION_MAXNAMELEN];
 263 };
 264
 265 struct ipt_error
 266 {
 267         struct ipt_entry entry;
 268         struct ipt_error_target target;
 269 };
 270
 271 #define IPT_ENTRY_INIT(__size)                                                 \
 272 {                                                                              \
 273         .target_offset  = sizeof(struct ipt_entry),                            \
 274         .next_offset    = (__size),                                            \
 275 }
 276
 277 #define IPT_STANDARD_INIT(__verdict)                                           \
 278 {                                                                              \
 279         .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_standard)),         \
 280         .target         = XT_TARGET_INIT(IPT_STANDARD_TARGET,                  \
 281                                          sizeof(struct xt_standard_target)),   \
 282         .target.verdict = -(__verdict) - 1,                                    \
 283 }
 284
 285 #define IPT_ERROR_INIT                                                         \
 286 {                                                                              \
 287         .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_error)),            \
 288         .target         = XT_TARGET_INIT(IPT_ERROR_TARGET,                     \
 289                                          sizeof(struct ipt_error_target)),     \
 290         .target.errorname = "ERROR",                                           \
 291 }
 292
 293 extern unsigned int ipt_do_table(struct sk_buff *skb,
 294                                  unsigned int hook,
 295                                  const struct net_device *in,
 296                                  const struct net_device *out,
 297                                  struct xt_table *table);
 298
 299 #define IPT_ALIGN(s) XT_ALIGN(s)
 300
 301 #ifdef CONFIG_COMPAT
 302 #include <net/compat.h>
 303
 304 struct compat_ipt_entry
 305 {
 306         struct ipt_ip ip;
 307         compat_uint_t nfcache;
 308         u_int16_t target_offset;
 309         u_int16_t next_offset;
 310         compat_uint_t comefrom;
 311         struct compat_xt_counters counters;
 312         unsigned char elems[0];
 313 };
 314
 315 /* Helper functions */
 316 static inline struct ipt_entry_target *
 317 compat_ipt_get_target(struct compat_ipt_entry *e)
 318 {
 319         return (void *)e + e->target_offset;
 320 }
 321
 322 #define COMPAT_IPT_ALIGN(s)     COMPAT_XT_ALIGN(s)
 323
 324 /* fn returns 0 to continue iteration */
 325 #define COMPAT_IPT_MATCH_ITERATE(e, fn, args...) \
 326         XT_MATCH_ITERATE(struct compat_ipt_entry, e, fn, ## args)
 327
 328 /* fn returns 0 to continue iteration */
 329 #define COMPAT_IPT_ENTRY_ITERATE(entries, size, fn, args...) \
 330         XT_ENTRY_ITERATE(struct compat_ipt_entry, entries, size, fn, ## args)
 331
 332 /* fn returns 0 to continue iteration */
 333 #define COMPAT_IPT_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
 334         XT_ENTRY_ITERATE_CONTINUE(struct compat_ipt_entry, entries, size, n, \
 335                                   fn, ## args)
 336
 337 #endif /* CONFIG_COMPAT */
 338 #endif /*__KERNEL__*/
 339 #endif /* _IPTABLES_H */