1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3  * 25-Jul-1998 Major changes to allow for ip chain table
4  *
5  * 3-Jan-2000 Named tables to allow packet selection for different uses.
6  */
7 
8 /*
9  * 	Format of an IP6 firewall descriptor
10  *
11  * 	src, dst, src_mask, dst_mask are always stored in network byte order.
12  * 	flags are stored in host byte order (of course).
13  * 	Port numbers are stored in HOST byte order.
14  */
15 
16 #ifndef _IP6_TABLES_H
17 #define _IP6_TABLES_H
18 
19 #include <linux/types.h>
20 
21 #include <linux/if.h>
22 #include <linux/netfilter_ipv6.h>
23 
24 #include <linux/netfilter/x_tables.h>
25 
26 #define IP6T_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
27 #define IP6T_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
28 #define ip6t_match xt_match
29 #define ip6t_target xt_target
30 #define ip6t_table xt_table
31 #define ip6t_get_revision xt_get_revision
32 #define ip6t_entry_match xt_entry_match
33 #define ip6t_entry_target xt_entry_target
34 #define ip6t_standard_target xt_standard_target
35 #define ip6t_error_target xt_error_target
36 #define ip6t_counters xt_counters
37 #define IP6T_CONTINUE XT_CONTINUE
38 #define IP6T_RETURN XT_RETURN
39 
40 /* Pre-iptables-1.4.0 */
41 #include <linux/netfilter/xt_tcpudp.h>
42 #define ip6t_tcp xt_tcp
43 #define ip6t_udp xt_udp
44 #define IP6T_TCP_INV_SRCPT	XT_TCP_INV_SRCPT
45 #define IP6T_TCP_INV_DSTPT	XT_TCP_INV_DSTPT
46 #define IP6T_TCP_INV_FLAGS	XT_TCP_INV_FLAGS
47 #define IP6T_TCP_INV_OPTION	XT_TCP_INV_OPTION
48 #define IP6T_TCP_INV_MASK	XT_TCP_INV_MASK
49 #define IP6T_UDP_INV_SRCPT	XT_UDP_INV_SRCPT
50 #define IP6T_UDP_INV_DSTPT	XT_UDP_INV_DSTPT
51 #define IP6T_UDP_INV_MASK	XT_UDP_INV_MASK
52 
53 #define ip6t_counters_info xt_counters_info
54 #define IP6T_STANDARD_TARGET XT_STANDARD_TARGET
55 #define IP6T_ERROR_TARGET XT_ERROR_TARGET
56 #define IP6T_MATCH_ITERATE(e, fn, args...) \
57 	XT_MATCH_ITERATE(struct ip6t_entry, e, fn, ## args)
58 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...) \
59 	XT_ENTRY_ITERATE(struct ip6t_entry, entries, size, fn, ## args)
60 
61 /* Yes, Virginia, you have to zero the padding. */
62 struct ip6t_ip6 {
63 	/* Source and destination IP6 addr */
64 	struct in6_addr src, dst;
65 	/* Mask for src and dest IP6 addr */
66 	struct in6_addr smsk, dmsk;
67 	char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
68 	unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
69 
70 	/* Upper protocol number
71 	 * - The allowed value is 0 (any) or protocol number of last parsable
72 	 *   header, which is 50 (ESP), 59 (No Next Header), 135 (MH), or
73 	 *   the non IPv6 extension headers.
74 	 * - The protocol numbers of IPv6 extension headers except of ESP and
75 	 *   MH do not match any packets.
76 	 * - You also need to set IP6T_FLAGS_PROTO to "flags" to check protocol.
77 	 */
78 	__u16 proto;
79 	/* TOS to match iff flags & IP6T_F_TOS */
80 	__u8 tos;
81 
82 	/* Flags word */
83 	__u8 flags;
84 	/* Inverse flags */
85 	__u8 invflags;
86 };
87 
88 /* Values for "flag" field in struct ip6t_ip6 (general ip6 structure). */
89 #define IP6T_F_PROTO		0x01	/* Set if rule cares about upper
90 					   protocols */
91 #define IP6T_F_TOS		0x02	/* Match the TOS. */
92 #define IP6T_F_GOTO		0x04	/* Set if jump is a goto */
93 #define IP6T_F_MASK		0x07	/* All possible flag bits mask. */
94 
95 /* Values for "inv" field in struct ip6t_ip6. */
96 #define IP6T_INV_VIA_IN		0x01	/* Invert the sense of IN IFACE. */
97 #define IP6T_INV_VIA_OUT		0x02	/* Invert the sense of OUT IFACE */
98 #define IP6T_INV_TOS		0x04	/* Invert the sense of TOS. */
99 #define IP6T_INV_SRCIP		0x08	/* Invert the sense of SRC IP. */
100 #define IP6T_INV_DSTIP		0x10	/* Invert the sense of DST OP. */
101 #define IP6T_INV_FRAG		0x20	/* Invert the sense of FRAG. */
102 #define IP6T_INV_PROTO		XT_INV_PROTO
103 #define IP6T_INV_MASK		0x7F	/* All possible flag bits mask. */
104 
105 /* This structure defines each of the firewall rules.  Consists of 3
106    parts which are 1) general IP header stuff 2) match specific
107    stuff 3) the target to perform if the rule matches */
108 struct ip6t_entry {
109 	struct ip6t_ip6 ipv6;
110 
111 	/* Mark with fields that we care about. */
112 	unsigned int nfcache;
113 
114 	/* Size of ipt_entry + matches */
115 	__u16 target_offset;
116 	/* Size of ipt_entry + matches + target */
117 	__u16 next_offset;
118 
119 	/* Back pointer */
120 	unsigned int comefrom;
121 
122 	/* Packet and byte counters. */
123 	struct xt_counters counters;
124 
125 	/* The matches (if any), then the target. */
126 	unsigned char elems[0];
127 };
128 
129 /* Standard entry */
130 struct ip6t_standard {
131 	struct ip6t_entry entry;
132 	struct xt_standard_target target;
133 };
134 
135 struct ip6t_error {
136 	struct ip6t_entry entry;
137 	struct xt_error_target target;
138 };
139 
140 #define IP6T_ENTRY_INIT(__size)						       \
141 {									       \
142 	.target_offset	= sizeof(struct ip6t_entry),			       \
143 	.next_offset	= (__size),					       \
144 }
145 
146 #define IP6T_STANDARD_INIT(__verdict)					       \
147 {									       \
148 	.entry		= IP6T_ENTRY_INIT(sizeof(struct ip6t_standard)),       \
149 	.target		= XT_TARGET_INIT(XT_STANDARD_TARGET,		       \
150 					 sizeof(struct xt_standard_target)),   \
151 	.target.verdict	= -(__verdict) - 1,				       \
152 }
153 
154 #define IP6T_ERROR_INIT							       \
155 {									       \
156 	.entry		= IP6T_ENTRY_INIT(sizeof(struct ip6t_error)),	       \
157 	.target		= XT_TARGET_INIT(XT_ERROR_TARGET,		       \
158 					 sizeof(struct xt_error_target)),      \
159 	.target.errorname = "ERROR",					       \
160 }
161 
162 /*
163  * New IP firewall options for [gs]etsockopt at the RAW IP level.
164  * Unlike BSD Linux inherits IP options so you don't have to use
165  * a raw socket for this. Instead we check rights in the calls.
166  *
167  * ATTENTION: check linux/in6.h before adding new number here.
168  */
169 #define IP6T_BASE_CTL			64
170 
171 #define IP6T_SO_SET_REPLACE		(IP6T_BASE_CTL)
172 #define IP6T_SO_SET_ADD_COUNTERS	(IP6T_BASE_CTL + 1)
173 #define IP6T_SO_SET_MAX			IP6T_SO_SET_ADD_COUNTERS
174 
175 #define IP6T_SO_GET_INFO		(IP6T_BASE_CTL)
176 #define IP6T_SO_GET_ENTRIES		(IP6T_BASE_CTL + 1)
177 #define IP6T_SO_GET_REVISION_MATCH	(IP6T_BASE_CTL + 4)
178 #define IP6T_SO_GET_REVISION_TARGET	(IP6T_BASE_CTL + 5)
179 #define IP6T_SO_GET_MAX			IP6T_SO_GET_REVISION_TARGET
180 
181 /* obtain original address if REDIRECT'd connection */
182 #define IP6T_SO_ORIGINAL_DST            80
183 
184 /* ICMP matching stuff */
185 struct ip6t_icmp {
186 	__u8 type;				/* type to match */
187 	__u8 code[2];				/* range of code */
188 	__u8 invflags;				/* Inverse flags */
189 };
190 
191 /* Values for "inv" field for struct ipt_icmp. */
192 #define IP6T_ICMP_INV	0x01	/* Invert the sense of type/code test */
193 
194 /* The argument to IP6T_SO_GET_INFO */
195 struct ip6t_getinfo {
196 	/* Which table: caller fills this in. */
197 	char name[XT_TABLE_MAXNAMELEN];
198 
199 	/* Kernel fills these in. */
200 	/* Which hook entry points are valid: bitmask */
201 	unsigned int valid_hooks;
202 
203 	/* Hook entry points: one per netfilter hook. */
204 	unsigned int hook_entry[NF_INET_NUMHOOKS];
205 
206 	/* Underflow points. */
207 	unsigned int underflow[NF_INET_NUMHOOKS];
208 
209 	/* Number of entries */
210 	unsigned int num_entries;
211 
212 	/* Size of entries. */
213 	unsigned int size;
214 };
215 
216 /* The argument to IP6T_SO_SET_REPLACE. */
217 struct ip6t_replace {
218 	/* Which table. */
219 	char name[XT_TABLE_MAXNAMELEN];
220 
221 	/* Which hook entry points are valid: bitmask.  You can't
222            change this. */
223 	unsigned int valid_hooks;
224 
225 	/* Number of entries */
226 	unsigned int num_entries;
227 
228 	/* Total size of new entries */
229 	unsigned int size;
230 
231 	/* Hook entry points. */
232 	unsigned int hook_entry[NF_INET_NUMHOOKS];
233 
234 	/* Underflow points. */
235 	unsigned int underflow[NF_INET_NUMHOOKS];
236 
237 	/* Information about old entries: */
238 	/* Number of counters (must be equal to current number of entries). */
239 	unsigned int num_counters;
240 	/* The old entries' counters. */
241 	struct xt_counters *counters;
242 
243 	/* The entries (hang off end: not really an array). */
244 	struct ip6t_entry entries[0];
245 };
246 
247 /* The argument to IP6T_SO_GET_ENTRIES. */
248 struct ip6t_get_entries {
249 	/* Which table: user fills this in. */
250 	char name[XT_TABLE_MAXNAMELEN];
251 
252 	/* User fills this in: total entry size. */
253 	unsigned int size;
254 
255 	/* The entries. */
256 	struct ip6t_entry entrytable[0];
257 };
258 
259 /* Helper functions */
260 static __inline__ struct xt_entry_target *
ip6t_get_target(struct ip6t_entry * e)261 ip6t_get_target(struct ip6t_entry *e)
262 {
263 	return (struct xt_entry_target *)((char *)e + e->target_offset);
264 }
265 
266 /*
267  *	Main firewall chains definitions and global var's definitions.
268  */
269 
270 #endif /* _IP6_TABLES_H */