1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * Format of an ARP firewall descriptor
4 *
5 * src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in
6 * network byte order.
7 * flags are stored in host byte order (of course).
8 */
9
10#ifndef _UAPI_ARPTABLES_H
11#define _UAPI_ARPTABLES_H
12
13#include <linux/types.h>
14#include <linux/compiler.h>
15#include <linux/if.h>
16#include <linux/netfilter_arp.h>
17
18#include <linux/netfilter/x_tables.h>
19
20#ifndef __KERNEL__
21#define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
22#define ARPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
23#define arpt_entry_target xt_entry_target
24#define arpt_standard_target xt_standard_target
25#define arpt_error_target xt_error_target
26#define ARPT_CONTINUE XT_CONTINUE
27#define ARPT_RETURN XT_RETURN
28#define arpt_counters_info xt_counters_info
29#define arpt_counters xt_counters
30#define ARPT_STANDARD_TARGET XT_STANDARD_TARGET
31#define ARPT_ERROR_TARGET XT_ERROR_TARGET
32#define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
33 XT_ENTRY_ITERATE(struct arpt_entry, entries, size, fn, ## args)
34#endif
35
36#define ARPT_DEV_ADDR_LEN_MAX 16
37
38struct arpt_devaddr_info {
39 char addr[ARPT_DEV_ADDR_LEN_MAX];
40 char mask[ARPT_DEV_ADDR_LEN_MAX];
41};
42
43/* Yes, Virginia, you have to zero the padding. */
44struct arpt_arp {
45 /* Source and target IP addr */
46 struct in_addr src, tgt;
47 /* Mask for src and target IP addr */
48 struct in_addr smsk, tmsk;
49
50 /* Device hw address length, src+target device addresses */
51 __u8 arhln, arhln_mask;
52 struct arpt_devaddr_info src_devaddr;
53 struct arpt_devaddr_info tgt_devaddr;
54
55 /* ARP operation code. */
56 __be16 arpop, arpop_mask;
57
58 /* ARP hardware address and protocol address format. */
59 __be16 arhrd, arhrd_mask;
60 __be16 arpro, arpro_mask;
61
62 /* The protocol address length is only accepted if it is 4
63 * so there is no use in offering a way to do filtering on it.
64 */
65
66 char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
67 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
68
69 /* Flags word */
70 __u8 flags;
71 /* Inverse flags */
72 __u16 invflags;
73};
74
75/* Values for "flag" field in struct arpt_ip (general arp structure).
76 * No flags defined yet.
77 */
78#define ARPT_F_MASK 0x00 /* All possible flag bits mask. */
79
80/* Values for "inv" field in struct arpt_arp. */
81#define ARPT_INV_VIA_IN 0x0001 /* Invert the sense of IN IFACE. */
82#define ARPT_INV_VIA_OUT 0x0002 /* Invert the sense of OUT IFACE */
83#define ARPT_INV_SRCIP 0x0004 /* Invert the sense of SRC IP. */
84#define ARPT_INV_TGTIP 0x0008 /* Invert the sense of TGT IP. */
85#define ARPT_INV_SRCDEVADDR 0x0010 /* Invert the sense of SRC DEV ADDR. */
86#define ARPT_INV_TGTDEVADDR 0x0020 /* Invert the sense of TGT DEV ADDR. */
87#define ARPT_INV_ARPOP 0x0040 /* Invert the sense of ARP OP. */
88#define ARPT_INV_ARPHRD 0x0080 /* Invert the sense of ARP HRD. */
89#define ARPT_INV_ARPPRO 0x0100 /* Invert the sense of ARP PRO. */
90#define ARPT_INV_ARPHLN 0x0200 /* Invert the sense of ARP HLN. */
91#define ARPT_INV_MASK 0x03FF /* All possible flag bits mask. */
92
93/* This structure defines each of the firewall rules. Consists of 3
94 parts which are 1) general ARP header stuff 2) match specific
95 stuff 3) the target to perform if the rule matches */
96struct arpt_entry
97{
98 struct arpt_arp arp;
99
100 /* Size of arpt_entry + matches */
101 __u16 target_offset;
102 /* Size of arpt_entry + matches + target */
103 __u16 next_offset;
104
105 /* Back pointer */
106 unsigned int comefrom;
107
108 /* Packet and byte counters. */
109 struct xt_counters counters;
110
111 /* The matches (if any), then the target. */
112 unsigned char elems[0];
113};
114
115/*
116 * New IP firewall options for [gs]etsockopt at the RAW IP level.
117 * Unlike BSD Linux inherits IP options so you don't have to use a raw
118 * socket for this. Instead we check rights in the calls.
119 *
120 * ATTENTION: check linux/in.h before adding new number here.
121 */
122#define ARPT_BASE_CTL 96
123
124#define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL)
125#define ARPT_SO_SET_ADD_COUNTERS (ARPT_BASE_CTL + 1)
126#define ARPT_SO_SET_MAX ARPT_SO_SET_ADD_COUNTERS
127
128#define ARPT_SO_GET_INFO (ARPT_BASE_CTL)
129#define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1)
130/* #define ARPT_SO_GET_REVISION_MATCH (APRT_BASE_CTL + 2) */
131#define ARPT_SO_GET_REVISION_TARGET (ARPT_BASE_CTL + 3)
132#define ARPT_SO_GET_MAX (ARPT_SO_GET_REVISION_TARGET)
133
134/* The argument to ARPT_SO_GET_INFO */
135struct arpt_getinfo {
136 /* Which table: caller fills this in. */
137 char name[XT_TABLE_MAXNAMELEN];
138
139 /* Kernel fills these in. */
140 /* Which hook entry points are valid: bitmask */
141 unsigned int valid_hooks;
142
143 /* Hook entry points: one per netfilter hook. */
144 unsigned int hook_entry[NF_ARP_NUMHOOKS];
145
146 /* Underflow points. */
147 unsigned int underflow[NF_ARP_NUMHOOKS];
148
149 /* Number of entries */
150 unsigned int num_entries;
151
152 /* Size of entries. */
153 unsigned int size;
154};
155
156/* The argument to ARPT_SO_SET_REPLACE. */
157struct arpt_replace {
158 /* Which table. */
159 char name[XT_TABLE_MAXNAMELEN];
160
161 /* Which hook entry points are valid: bitmask. You can't
162 change this. */
163 unsigned int valid_hooks;
164
165 /* Number of entries */
166 unsigned int num_entries;
167
168 /* Total size of new entries */
169 unsigned int size;
170
171 /* Hook entry points. */
172 unsigned int hook_entry[NF_ARP_NUMHOOKS];
173
174 /* Underflow points. */
175 unsigned int underflow[NF_ARP_NUMHOOKS];
176
177 /* Information about old entries: */
178 /* Number of counters (must be equal to current number of entries). */
179 unsigned int num_counters;
180 /* The old entries' counters. */
181 struct xt_counters __user *counters;
182
183 /* The entries (hang off end: not really an array). */
184 struct arpt_entry entries[0];
185};
186
187/* The argument to ARPT_SO_GET_ENTRIES. */
188struct arpt_get_entries {
189 /* Which table: user fills this in. */
190 char name[XT_TABLE_MAXNAMELEN];
191
192 /* User fills this in: total entry size. */
193 unsigned int size;
194
195 /* The entries. */
196 struct arpt_entry entrytable[0];
197};
198
199/* Helper functions */
200static __inline__ struct xt_entry_target *arpt_get_target(struct arpt_entry *e)
201{
202 return (void *)e + e->target_offset;
203}
204
205/*
206 * Main firewall chains definitions and global var's definitions.
207 */
208#endif /* _UAPI_ARPTABLES_H */
209