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001: /*
002:  *      Format of an ARP firewall descriptor
003:  *
004:  *      src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in
005:  *      network byte order.
006:  *      flags are stored in host byte order (of course).
007:  */
008: 
009: #ifndef _ARPTABLES_H
010: #define _ARPTABLES_H
011: 
012: #include <linux/types.h>
013: 
014: #include <linux/netfilter_arp.h>
015: 
016: #include <linux/netfilter/x_tables.h>
017: 
018: #define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
019: #define ARPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
020: #define arpt_entry_target xt_entry_target
021: #define arpt_standard_target xt_standard_target
022: #define arpt_error_target xt_error_target
023: #define ARPT_CONTINUE XT_CONTINUE
024: #define ARPT_RETURN XT_RETURN
025: #define arpt_counters_info xt_counters_info
026: #define arpt_counters xt_counters
027: #define ARPT_STANDARD_TARGET XT_STANDARD_TARGET
028: #define ARPT_ERROR_TARGET XT_ERROR_TARGET
029: #define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
030:         XT_ENTRY_ITERATE(struct arpt_entry, entries, size, fn, ## args)
031: 
032: #define ARPT_DEV_ADDR_LEN_MAX 16
033: 
034: struct arpt_devaddr_info {
035:         char addr[ARPT_DEV_ADDR_LEN_MAX];
036:         char mask[ARPT_DEV_ADDR_LEN_MAX];
037: };
038: 
039: /* Yes, Virginia, you have to zero the padding. */
040: struct arpt_arp {
041:         /* Source and target IP addr */
042:         struct in_addr src, tgt;
043:         /* Mask for src and target IP addr */
044:         struct in_addr smsk, tmsk;
045: 
046:         /* Device hw address length, src+target device addresses */
047:         __u8 arhln, arhln_mask;
048:         struct arpt_devaddr_info src_devaddr;
049:         struct arpt_devaddr_info tgt_devaddr;
050: 
051:         /* ARP operation code. */
052:         __be16 arpop, arpop_mask;
053: 
054:         /* ARP hardware address and protocol address format. */
055:         __be16 arhrd, arhrd_mask;
056:         __be16 arpro, arpro_mask;
057: 
058:         /* The protocol address length is only accepted if it is 4
059:          * so there is no use in offering a way to do filtering on it.
060:          */
061: 
062:         char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
063:         unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
064: 
065:         /* Flags word */
066:         __u8 flags;
067:         /* Inverse flags */
068:         __u16 invflags;
069: };
070: 
071: /* Values for "flag" field in struct arpt_ip (general arp structure).
072:  * No flags defined yet.
073:  */
074: #define ARPT_F_MASK             0x00    /* All possible flag bits mask. */
075: 
076: /* Values for "inv" field in struct arpt_arp. */
077: #define ARPT_INV_VIA_IN         0x0001  /* Invert the sense of IN IFACE. */
078: #define ARPT_INV_VIA_OUT        0x0002  /* Invert the sense of OUT IFACE */
079: #define ARPT_INV_SRCIP          0x0004  /* Invert the sense of SRC IP. */
080: #define ARPT_INV_TGTIP          0x0008  /* Invert the sense of TGT IP. */
081: #define ARPT_INV_SRCDEVADDR     0x0010  /* Invert the sense of SRC DEV ADDR. */
082: #define ARPT_INV_TGTDEVADDR     0x0020  /* Invert the sense of TGT DEV ADDR. */
083: #define ARPT_INV_ARPOP          0x0040  /* Invert the sense of ARP OP. */
084: #define ARPT_INV_ARPHRD         0x0080  /* Invert the sense of ARP HRD. */
085: #define ARPT_INV_ARPPRO         0x0100  /* Invert the sense of ARP PRO. */
086: #define ARPT_INV_ARPHLN         0x0200  /* Invert the sense of ARP HLN. */
087: #define ARPT_INV_MASK           0x03FF  /* All possible flag bits mask. */
088: 
089: /* This structure defines each of the firewall rules.  Consists of 3
090:    parts which are 1) general ARP header stuff 2) match specific
091:    stuff 3) the target to perform if the rule matches */
092: struct arpt_entry
093: {
094:         struct arpt_arp arp;
095: 
096:         /* Size of arpt_entry + matches */
097:         __u16 target_offset;
098:         /* Size of arpt_entry + matches + target */
099:         __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: 

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