ip_tables.h revision ab322673298bd0b8927cdd9d11f3d36af5941b93
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#include <linux/types.h> 19 20#include <linux/netfilter_ipv4.h> 21 22#include <linux/netfilter/x_tables.h> 23 24#define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN 25#define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN 26#define ipt_match xt_match 27#define ipt_target xt_target 28#define ipt_table xt_table 29#define ipt_get_revision xt_get_revision 30 31/* Yes, Virginia, you have to zero the padding. */ 32struct ipt_ip { 33 /* Source and destination IP addr */ 34 struct in_addr src, dst; 35 /* Mask for src and dest IP addr */ 36 struct in_addr smsk, dmsk; 37 char iniface[IFNAMSIZ], outiface[IFNAMSIZ]; 38 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ]; 39 40 /* Protocol, 0 = ANY */ 41 u_int16_t proto; 42 43 /* Flags word */ 44 u_int8_t flags; 45 /* Inverse flags */ 46 u_int8_t invflags; 47}; 48 49#define ipt_entry_match xt_entry_match 50#define ipt_entry_target xt_entry_target 51#define ipt_standard_target xt_standard_target 52 53#define ipt_counters xt_counters 54 55/* Values for "flag" field in struct ipt_ip (general ip structure). */ 56#define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */ 57#define IPT_F_GOTO 0x02 /* Set if jump is a goto */ 58#define IPT_F_MASK 0x03 /* All possible flag bits mask. */ 59 60/* Values for "inv" field in struct ipt_ip. */ 61#define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */ 62#define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */ 63#define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */ 64#define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */ 65#define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */ 66#define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */ 67#define IPT_INV_PROTO XT_INV_PROTO 68#define IPT_INV_MASK 0x7F /* All possible flag bits mask. */ 69 70/* This structure defines each of the firewall rules. Consists of 3 71 parts which are 1) general IP header stuff 2) match specific 72 stuff 3) the target to perform if the rule matches */ 73struct ipt_entry { 74 struct ipt_ip ip; 75 76 /* Mark with fields that we care about. */ 77 unsigned int nfcache; 78 79 /* Size of ipt_entry + matches */ 80 u_int16_t target_offset; 81 /* Size of ipt_entry + matches + target */ 82 u_int16_t next_offset; 83 84 /* Back pointer */ 85 unsigned int comefrom; 86 87 /* Packet and byte counters. */ 88 struct xt_counters counters; 89 90 /* The matches (if any), then the target. */ 91 unsigned char elems[0]; 92}; 93 94/* 95 * New IP firewall options for [gs]etsockopt at the RAW IP level. 96 * Unlike BSD Linux inherits IP options so you don't have to use a raw 97 * socket for this. Instead we check rights in the calls. 98 * 99 * ATTENTION: check linux/in.h before adding new number here. 100 */ 101#define IPT_BASE_CTL 64 102 103#define IPT_SO_SET_REPLACE (IPT_BASE_CTL) 104#define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1) 105#define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS 106 107#define IPT_SO_GET_INFO (IPT_BASE_CTL) 108#define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1) 109#define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2) 110#define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3) 111#define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET 112 113#define IPT_CONTINUE XT_CONTINUE 114#define IPT_RETURN XT_RETURN 115 116#include <linux/netfilter/xt_tcpudp.h> 117#define ipt_udp xt_udp 118#define ipt_tcp xt_tcp 119 120#define IPT_TCP_INV_SRCPT XT_TCP_INV_SRCPT 121#define IPT_TCP_INV_DSTPT XT_TCP_INV_DSTPT 122#define IPT_TCP_INV_FLAGS XT_TCP_INV_FLAGS 123#define IPT_TCP_INV_OPTION XT_TCP_INV_OPTION 124#define IPT_TCP_INV_MASK XT_TCP_INV_MASK 125 126#define IPT_UDP_INV_SRCPT XT_UDP_INV_SRCPT 127#define IPT_UDP_INV_DSTPT XT_UDP_INV_DSTPT 128#define IPT_UDP_INV_MASK XT_UDP_INV_MASK 129 130/* ICMP matching stuff */ 131struct ipt_icmp { 132 u_int8_t type; /* type to match */ 133 u_int8_t code[2]; /* range of code */ 134 u_int8_t invflags; /* Inverse flags */ 135}; 136 137/* Values for "inv" field for struct ipt_icmp. */ 138#define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */ 139 140/* The argument to IPT_SO_GET_INFO */ 141struct ipt_getinfo { 142 /* Which table: caller fills this in. */ 143 char name[IPT_TABLE_MAXNAMELEN]; 144 145 /* Kernel fills these in. */ 146 /* Which hook entry points are valid: bitmask */ 147 unsigned int valid_hooks; 148 149 /* Hook entry points: one per netfilter hook. */ 150 unsigned int hook_entry[NF_INET_NUMHOOKS]; 151 152 /* Underflow points. */ 153 unsigned int underflow[NF_INET_NUMHOOKS]; 154 155 /* Number of entries */ 156 unsigned int num_entries; 157 158 /* Size of entries. */ 159 unsigned int size; 160}; 161 162/* The argument to IPT_SO_SET_REPLACE. */ 163struct ipt_replace { 164 /* Which table. */ 165 char name[IPT_TABLE_MAXNAMELEN]; 166 167 /* Which hook entry points are valid: bitmask. You can't 168 change this. */ 169 unsigned int valid_hooks; 170 171 /* Number of entries */ 172 unsigned int num_entries; 173 174 /* Total size of new entries */ 175 unsigned int size; 176 177 /* Hook entry points. */ 178 unsigned int hook_entry[NF_INET_NUMHOOKS]; 179 180 /* Underflow points. */ 181 unsigned int underflow[NF_INET_NUMHOOKS]; 182 183 /* Information about old entries: */ 184 /* Number of counters (must be equal to current number of entries). */ 185 unsigned int num_counters; 186 /* The old entries' counters. */ 187 struct xt_counters *counters; 188 189 /* The entries (hang off end: not really an array). */ 190 struct ipt_entry entries[0]; 191}; 192 193/* The argument to IPT_SO_ADD_COUNTERS. */ 194#define ipt_counters_info xt_counters_info 195 196/* The argument to IPT_SO_GET_ENTRIES. */ 197struct ipt_get_entries { 198 /* Which table: user fills this in. */ 199 char name[IPT_TABLE_MAXNAMELEN]; 200 201 /* User fills this in: total entry size. */ 202 unsigned int size; 203 204 /* The entries. */ 205 struct ipt_entry entrytable[0]; 206}; 207 208/* Standard return verdict, or do jump. */ 209#define IPT_STANDARD_TARGET XT_STANDARD_TARGET 210/* Error verdict. */ 211#define IPT_ERROR_TARGET XT_ERROR_TARGET 212 213/* Helper functions */ 214static __inline__ struct ipt_entry_target * 215ipt_get_target(struct ipt_entry *e) 216{ 217 return (void *)e + e->target_offset; 218} 219 220/* fn returns 0 to continue iteration */ 221#define IPT_MATCH_ITERATE(e, fn, args...) \ 222 XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args) 223 224/* fn returns 0 to continue iteration */ 225#define IPT_ENTRY_ITERATE(entries, size, fn, args...) \ 226 XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args) 227 228/* 229 * Main firewall chains definitions and global var's definitions. 230 */ 231#endif /* _IPTABLES_H */ 232