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/in.h>
  21 #include <linux/ip.h>
  22 #include <linux/skbuff.h>
  23 #endif
  24 #include <linux/types.h>
  25 #include <linux/compiler.h>
  26 #include <linux/netfilter_ipv4.h>
  27
  28 #include <linux/netfilter/x_tables.h>
  29
  30 #ifndef __KERNEL__
  31 #define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
  32 #define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
  33 #define ipt_match xt_match
  34 #define ipt_target xt_target
  35 #define ipt_table xt_table
  36 #define ipt_get_revision xt_get_revision
  37 #define ipt_entry_match xt_entry_match
  38 #define ipt_entry_target xt_entry_target
  39 #define ipt_standard_target xt_standard_target
  40 #define ipt_error_target xt_error_target
  41 #define ipt_counters xt_counters
  42 #define IPT_CONTINUE XT_CONTINUE
  43 #define IPT_RETURN XT_RETURN
  44
  45 /* This group is older than old (iptables < v1.4.0-rc1~89) */
  46 #include <linux/netfilter/xt_tcpudp.h>
  47 #define ipt_udp xt_udp
  48 #define ipt_tcp xt_tcp
  49 #define IPT_TCP_INV_SRCPT       XT_TCP_INV_SRCPT
  50 #define IPT_TCP_INV_DSTPT       XT_TCP_INV_DSTPT
  51 #define IPT_TCP_INV_FLAGS       XT_TCP_INV_FLAGS
  52 #define IPT_TCP_INV_OPTION      XT_TCP_INV_OPTION
  53 #define IPT_TCP_INV_MASK        XT_TCP_INV_MASK
  54 #define IPT_UDP_INV_SRCPT       XT_UDP_INV_SRCPT
  55 #define IPT_UDP_INV_DSTPT       XT_UDP_INV_DSTPT
  56 #define IPT_UDP_INV_MASK        XT_UDP_INV_MASK
  57
  58 /* The argument to IPT_SO_ADD_COUNTERS. */
  59 #define ipt_counters_info xt_counters_info
  60 /* Standard return verdict, or do jump. */
  61 #define IPT_STANDARD_TARGET XT_STANDARD_TARGET
  62 /* Error verdict. */
  63 #define IPT_ERROR_TARGET XT_ERROR_TARGET
  64
  65 /* fn returns 0 to continue iteration */
  66 #define IPT_MATCH_ITERATE(e, fn, args...) \
  67         XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
  68
  69 /* fn returns 0 to continue iteration */
  70 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
  71         XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
  72 #endif
  73
  74 /* Yes, Virginia, you have to zero the padding. */
  75 struct ipt_ip {
  76         /* Source and destination IP addr */
  77         struct in_addr src, dst;
  78         /* Mask for src and dest IP addr */
  79         struct in_addr smsk, dmsk;
  80         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
  81         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
  82
  83         /* Protocol, 0 = ANY */
  84         u_int16_t proto;
  85
  86         /* Flags word */
  87         u_int8_t flags;
  88         /* Inverse flags */
  89         u_int8_t invflags;
  90 };
  91
  92 /* Values for "flag" field in struct ipt_ip (general ip structure). */
  93 #define IPT_F_FRAG              0x01    /* Set if rule is a fragment rule */
  94 #define IPT_F_GOTO              0x02    /* Set if jump is a goto */
  95 #define IPT_F_MASK              0x03    /* All possible flag bits mask. */
  96
  97 /* Values for "inv" field in struct ipt_ip. */
  98 #define IPT_INV_VIA_IN          0x01    /* Invert the sense of IN IFACE. */
  99 #define IPT_INV_VIA_OUT         0x02    /* Invert the sense of OUT IFACE */
 100 #define IPT_INV_TOS             0x04    /* Invert the sense of TOS. */
 101 #define IPT_INV_SRCIP           0x08    /* Invert the sense of SRC IP. */
 102 #define IPT_INV_DSTIP           0x10    /* Invert the sense of DST OP. */
 103 #define IPT_INV_FRAG            0x20    /* Invert the sense of FRAG. */
 104 #define IPT_INV_PROTO           XT_INV_PROTO
 105 #define IPT_INV_MASK            0x7F    /* All possible flag bits mask. */
 106
 107 /* This structure defines each of the firewall rules.  Consists of 3
 108    parts which are 1) general IP header stuff 2) match specific
 109    stuff 3) the target to perform if the rule matches */
 110 struct ipt_entry {
 111         struct ipt_ip ip;
 112
 113         /* Mark with fields that we care about. */
 114         unsigned int nfcache;
 115
 116         /* Size of ipt_entry + matches */
 117         u_int16_t target_offset;
 118         /* Size of ipt_entry + matches + target */
 119         u_int16_t next_offset;
 120
 121         /* Back pointer */
 122         unsigned int comefrom;
 123
 124         /* Packet and byte counters. */
 125         struct xt_counters counters;
 126
 127         /* The matches (if any), then the target. */
 128         unsigned char elems[0];
 129 };
 130
 131 /*
 132  * New IP firewall options for [gs]etsockopt at the RAW IP level.
 133  * Unlike BSD Linux inherits IP options so you don't have to use a raw
 134  * socket for this. Instead we check rights in the calls.
 135  *
 136  * ATTENTION: check linux/in.h before adding new number here.
 137  */
 138 #define IPT_BASE_CTL            64
 139
 140 #define IPT_SO_SET_REPLACE      (IPT_BASE_CTL)
 141 #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
 142 #define IPT_SO_SET_MAX          IPT_SO_SET_ADD_COUNTERS
 143
 144 #define IPT_SO_GET_INFO                 (IPT_BASE_CTL)
 145 #define IPT_SO_GET_ENTRIES              (IPT_BASE_CTL + 1)
 146 #define IPT_SO_GET_REVISION_MATCH       (IPT_BASE_CTL + 2)
 147 #define IPT_SO_GET_REVISION_TARGET      (IPT_BASE_CTL + 3)
 148 #define IPT_SO_GET_MAX                  IPT_SO_GET_REVISION_TARGET
 149
 150 /* ICMP matching stuff */
 151 struct ipt_icmp {
 152         u_int8_t type;                          /* type to match */
 153         u_int8_t code[2];                       /* range of code */
 154         u_int8_t invflags;                      /* Inverse flags */
 155 };
 156
 157 /* Values for "inv" field for struct ipt_icmp. */
 158 #define IPT_ICMP_INV    0x01    /* Invert the sense of type/code test */
 159
 160 /* The argument to IPT_SO_GET_INFO */
 161 struct ipt_getinfo {
 162         /* Which table: caller fills this in. */
 163         char name[XT_TABLE_MAXNAMELEN];
 164
 165         /* Kernel fills these in. */
 166         /* Which hook entry points are valid: bitmask */
 167         unsigned int valid_hooks;
 168
 169         /* Hook entry points: one per netfilter hook. */
 170         unsigned int hook_entry[NF_INET_NUMHOOKS];
 171
 172         /* Underflow points. */
 173         unsigned int underflow[NF_INET_NUMHOOKS];
 174
 175         /* Number of entries */
 176         unsigned int num_entries;
 177
 178         /* Size of entries. */
 179         unsigned int size;
 180 };
 181
 182 /* The argument to IPT_SO_SET_REPLACE. */
 183 struct ipt_replace {
 184         /* Which table. */
 185         char name[XT_TABLE_MAXNAMELEN];
 186
 187         /* Which hook entry points are valid: bitmask.  You can't
 188            change this. */
 189         unsigned int valid_hooks;
 190
 191         /* Number of entries */
 192         unsigned int num_entries;
 193
 194         /* Total size of new entries */
 195         unsigned int size;
 196
 197         /* Hook entry points. */
 198         unsigned int hook_entry[NF_INET_NUMHOOKS];
 199
 200         /* Underflow points. */
 201         unsigned int underflow[NF_INET_NUMHOOKS];
 202
 203         /* Information about old entries: */
 204         /* Number of counters (must be equal to current number of entries). */
 205         unsigned int num_counters;
 206         /* The old entries' counters. */
 207         struct xt_counters __user *counters;
 208
 209         /* The entries (hang off end: not really an array). */
 210         struct ipt_entry entries[0];
 211 };
 212
 213 /* The argument to IPT_SO_GET_ENTRIES. */
 214 struct ipt_get_entries {
 215         /* Which table: user fills this in. */
 216         char name[XT_TABLE_MAXNAMELEN];
 217
 218         /* User fills this in: total entry size. */
 219         unsigned int size;
 220
 221         /* The entries. */
 222         struct ipt_entry entrytable[0];
 223 };
 224
 225 /* Helper functions */
 226 static __inline__ struct xt_entry_target *
 227 ipt_get_target(struct ipt_entry *e)
 228 {
 229         return (void *)e + e->target_offset;
 230 }
 231
 232 /*
 233  *      Main firewall chains definitions and global var's definitions.
 234  */
 235 #ifdef __KERNEL__
 236
 237 #include <linux/init.h>
 238 extern void ipt_init(void) __init;
 239
 240 extern struct xt_table *ipt_register_table(struct net *net,
 241                                            const struct xt_table *table,
 242                                            const struct ipt_replace *repl);
 243 extern void ipt_unregister_table(struct net *net, struct xt_table *table);
 244
 245 /* Standard entry. */
 246 struct ipt_standard {
 247         struct ipt_entry entry;
 248         struct xt_standard_target target;
 249 };
 250
 251 struct ipt_error {
 252         struct ipt_entry entry;
 253         struct xt_error_target target;
 254 };
 255
 256 #define IPT_ENTRY_INIT(__size)                                                 \
 257 {                                                                              \
 258         .target_offset  = sizeof(struct ipt_entry),                            \
 259         .next_offset    = (__size),                                            \
 260 }
 261
 262 #define IPT_STANDARD_INIT(__verdict)                                           \
 263 {                                                                              \
 264         .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_standard)),         \
 265         .target         = XT_TARGET_INIT(XT_STANDARD_TARGET,                   \
 266                                          sizeof(struct xt_standard_target)),   \
 267         .target.verdict = -(__verdict) - 1,                                    \
 268 }
 269
 270 #define IPT_ERROR_INIT                                                         \
 271 {                                                                              \
 272         .entry          = IPT_ENTRY_INIT(sizeof(struct ipt_error)),            \
 273         .target         = XT_TARGET_INIT(XT_ERROR_TARGET,                      \
 274                                          sizeof(struct xt_error_target)),      \
 275         .target.errorname = "ERROR",                                           \
 276 }
 277
 278 extern void *ipt_alloc_initial_table(const struct xt_table *);
 279 extern unsigned int ipt_do_table(struct sk_buff *skb,
 280                                  unsigned int hook,
 281                                  const struct net_device *in,
 282                                  const struct net_device *out,
 283                                  struct xt_table *table);
 284
 285 #ifdef CONFIG_COMPAT
 286 #include <net/compat.h>
 287
 288 struct compat_ipt_entry {
 289         struct ipt_ip ip;
 290         compat_uint_t nfcache;
 291         u_int16_t target_offset;
 292         u_int16_t next_offset;
 293         compat_uint_t comefrom;
 294         struct compat_xt_counters counters;
 295         unsigned char elems[0];
 296 };
 297
 298 /* Helper functions */
 299 static inline struct xt_entry_target *
 300 compat_ipt_get_target(struct compat_ipt_entry *e)
 301 {
 302         return (void *)e + e->target_offset;
 303 }
 304
 305 #endif /* CONFIG_COMPAT */
 306 #endif /*__KERNEL__*/
 307 #endif /* _IPTABLES_H */