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