1 /* 2 * Format of an ARP firewall descriptor 3 * 4 * src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in 5 * network byte order. 6 * flags are stored in host byte order (of course). 7 */ 8 9 #ifndef _ARPTABLES_H 10 #define _ARPTABLES_H 11 12 #include <linux/types.h> 13 14 #include <linux/netfilter_arp.h> 15 16 #include <linux/netfilter/x_tables.h> 17 18 #define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN 19 #define ARPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN 20 #define arpt_entry_target xt_entry_target 21 #define arpt_standard_target xt_standard_target 22 #define arpt_error_target xt_error_target 23 #define ARPT_CONTINUE XT_CONTINUE 24 #define ARPT_RETURN XT_RETURN 25 #define arpt_counters_info xt_counters_info 26 #define arpt_counters xt_counters 27 #define ARPT_STANDARD_TARGET XT_STANDARD_TARGET 28 #define ARPT_ERROR_TARGET XT_ERROR_TARGET 29 #define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \ 30 XT_ENTRY_ITERATE(struct arpt_entry, entries, size, fn, ## args) 31 32 #define ARPT_DEV_ADDR_LEN_MAX 16 33 34 struct arpt_devaddr_info { 35 char addr[ARPT_DEV_ADDR_LEN_MAX]; 36 char mask[ARPT_DEV_ADDR_LEN_MAX]; 37 }; 38 39 /* Yes, Virginia, you have to zero the padding. */ 40 struct arpt_arp { 41 /* Source and target IP addr */ 42 struct in_addr src, tgt; 43 /* Mask for src and target IP addr */ 44 struct in_addr smsk, tmsk; 45 46 /* Device hw address length, src+target device addresses */ 47 __u8 arhln, arhln_mask; 48 struct arpt_devaddr_info src_devaddr; 49 struct arpt_devaddr_info tgt_devaddr; 50 51 /* ARP operation code. */ 52 __be16 arpop, arpop_mask; 53 54 /* ARP hardware address and protocol address format. */ 55 __be16 arhrd, arhrd_mask; 56 __be16 arpro, arpro_mask; 57 58 /* The protocol address length is only accepted if it is 4 59 * so there is no use in offering a way to do filtering on it. 60 */ 61 62 char iniface[IFNAMSIZ], outiface[IFNAMSIZ]; 63 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ]; 64 65 /* Flags word */ 66 __u8 flags; 67 /* Inverse flags */ 68 __u16 invflags; 69 }; 70 71 /* Values for "flag" field in struct arpt_ip (general arp structure). 72 * No flags defined yet. 73 */ 74 #define ARPT_F_MASK 0x00 /* All possible flag bits mask. */ 75 76 /* Values for "inv" field in struct arpt_arp. */ 77 #define ARPT_INV_VIA_IN 0x0001 /* Invert the sense of IN IFACE. */ 78 #define ARPT_INV_VIA_OUT 0x0002 /* Invert the sense of OUT IFACE */ 79 #define ARPT_INV_SRCIP 0x0004 /* Invert the sense of SRC IP. */ 80 #define ARPT_INV_TGTIP 0x0008 /* Invert the sense of TGT IP. */ 81 #define ARPT_INV_SRCDEVADDR 0x0010 /* Invert the sense of SRC DEV ADDR. */ 82 #define ARPT_INV_TGTDEVADDR 0x0020 /* Invert the sense of TGT DEV ADDR. */ 83 #define ARPT_INV_ARPOP 0x0040 /* Invert the sense of ARP OP. */ 84 #define ARPT_INV_ARPHRD 0x0080 /* Invert the sense of ARP HRD. */ 85 #define ARPT_INV_ARPPRO 0x0100 /* Invert the sense of ARP PRO. */ 86 #define ARPT_INV_ARPHLN 0x0200 /* Invert the sense of ARP HLN. */ 87 #define ARPT_INV_MASK 0x03FF /* All possible flag bits mask. */ 88 89 /* This structure defines each of the firewall rules. Consists of 3 90 parts which are 1) general ARP header stuff 2) match specific 91 stuff 3) the target to perform if the rule matches */ 92 struct arpt_entry 93 { 94 struct arpt_arp arp; 95 96 /* Size of arpt_entry + matches */ 97 __u16 target_offset; 98 /* Size of arpt_entry + matches + target */ 99 __u16 next_offset; 100 101 /* Back pointer */ 102 unsigned int comefrom; 103 104 /* Packet and byte counters. */ 105 struct xt_counters counters; 106 107 /* The matches (if any), then the target. */ 108 unsigned char elems[0]; 109 }; 110 111 /* 112 * New IP firewall options for [gs]etsockopt at the RAW IP level. 113 * Unlike BSD Linux inherits IP options so you don't have to use a raw 114 * socket for this. Instead we check rights in the calls. 115 * 116 * ATTENTION: check linux/in.h before adding new number here. 117 */ 118 #define ARPT_BASE_CTL 96 119 120 #define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL) 121 #define ARPT_SO_SET_ADD_COUNTERS (ARPT_BASE_CTL + 1) 122 #define ARPT_SO_SET_MAX ARPT_SO_SET_ADD_COUNTERS 123 124 #define ARPT_SO_GET_INFO (ARPT_BASE_CTL) 125 #define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1) 126 /* #define ARPT_SO_GET_REVISION_MATCH (APRT_BASE_CTL + 2) */ 127 #define ARPT_SO_GET_REVISION_TARGET (ARPT_BASE_CTL + 3) 128 #define ARPT_SO_GET_MAX (ARPT_SO_GET_REVISION_TARGET) 129 130 /* The argument to ARPT_SO_GET_INFO */ 131 struct arpt_getinfo { 132 /* Which table: caller fills this in. */ 133 char name[XT_TABLE_MAXNAMELEN]; 134 135 /* Kernel fills these in. */ 136 /* Which hook entry points are valid: bitmask */ 137 unsigned int valid_hooks; 138 139 /* Hook entry points: one per netfilter hook. */ 140 unsigned int hook_entry[NF_ARP_NUMHOOKS]; 141 142 /* Underflow points. */ 143 unsigned int underflow[NF_ARP_NUMHOOKS]; 144 145 /* Number of entries */ 146 unsigned int num_entries; 147 148 /* Size of entries. */ 149 unsigned int size; 150 }; 151 152 /* The argument to ARPT_SO_SET_REPLACE. */ 153 struct arpt_replace { 154 /* Which table. */ 155 char name[XT_TABLE_MAXNAMELEN]; 156 157 /* Which hook entry points are valid: bitmask. You can't 158 change this. */ 159 unsigned int valid_hooks; 160 161 /* Number of entries */ 162 unsigned int num_entries; 163 164 /* Total size of new entries */ 165 unsigned int size; 166 167 /* Hook entry points. */ 168 unsigned int hook_entry[NF_ARP_NUMHOOKS]; 169 170 /* Underflow points. */ 171 unsigned int underflow[NF_ARP_NUMHOOKS]; 172 173 /* Information about old entries: */ 174 /* Number of counters (must be equal to current number of entries). */ 175 unsigned int num_counters; 176 /* The old entries' counters. */ 177 struct xt_counters *counters; 178 179 /* The entries (hang off end: not really an array). */ 180 struct arpt_entry entries[0]; 181 }; 182 183 /* The argument to ARPT_SO_GET_ENTRIES. */ 184 struct arpt_get_entries { 185 /* Which table: user fills this in. */ 186 char name[XT_TABLE_MAXNAMELEN]; 187 188 /* User fills this in: total entry size. */ 189 unsigned int size; 190 191 /* The entries. */ 192 struct arpt_entry entrytable[0]; 193 }; 194 195 /* Helper functions */ 196 static __inline__ struct xt_entry_target *arpt_get_target(struct arpt_entry *e) 197 { 198 return (void *)e + e->target_offset; 199 } 200 201 /* 202 * Main firewall chains definitions and global var's definitions. 203 */ 204 #endif /* _ARPTABLES_H */ 205
