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/types.h>
19 #include <linux/netfilter_ipv4.h>
20
21 #include <linux/netfilter/x_tables.h>
22
23 #define IPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN
24 #define IPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN
25 #define ipt_match xt_match
26 #define ipt_target xt_target
27 #define ipt_table xt_table
28 #define ipt_get_revision xt_get_revision
29
30 /* Yes, Virginia, you have to zero the padding. */
31 struct ipt_ip {
32 /* Source and destination IP addr */
33 struct in_addr src, dst;
34 /* Mask for src and dest IP addr */
35 struct in_addr smsk, dmsk;
36 char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
37 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
38
39 /* Protocol, 0 = ANY */
40 u_int16_t proto;
41
42 /* Flags word */
43 u_int8_t flags;
44 /* Inverse flags */
45 u_int8_t invflags;
46 };
47
48 #define ipt_entry_match xt_entry_match
49 #define ipt_entry_target xt_entry_target
50 #define ipt_standard_target xt_standard_target
51
52 #define ipt_counters xt_counters
53
54 /* Values for "flag" field in struct ipt_ip (general ip structure). */
55 #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
56 #define IPT_F_GOTO 0x02 /* Set if jump is a goto */
57 #define IPT_F_MASK 0x03 /* All possible flag bits mask. */
58
59 /* Values for "inv" field in struct ipt_ip. */
60 #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
61 #define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */
62 #define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */
63 #define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */
64 #define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */
65 #define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */
66 #define IPT_INV_PROTO XT_INV_PROTO
67 #define IPT_INV_MASK 0x7F /* All possible flag bits mask. */
68
69 /* This structure defines each of the firewall rules. Consists of 3
70 parts which are 1) general IP header stuff 2) match specific
71 stuff 3) the target to perform if the rule matches */
72 struct ipt_entry
73 {
74 struct ipt_ip ip;
75
76 /* Mark with fields that we care about. */
77 unsigned int nfcache;
78
79 /* Size of ipt_entry + matches */
80 u_int16_t target_offset;
81 /* Size of ipt_entry + matches + target */
82 u_int16_t next_offset;
83
84 /* Back pointer */
85 unsigned int comefrom;
86
87 /* Packet and byte counters. */
88 struct xt_counters counters;
89
90 /* The matches (if any), then the target. */
91 unsigned char elems[0];
92 };
93
94 /*
95 * New IP firewall options for [gs]etsockopt at the RAW IP level.
96 * Unlike BSD Linux inherits IP options so you don't have to use a raw
97 * socket for this. Instead we check rights in the calls.
98 *
99 * ATTENTION: check linux/in.h before adding new number here.
100 */
101 #define IPT_BASE_CTL 64
102
103 #define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
104 #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
105 #define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS
106
107 #define IPT_SO_GET_INFO (IPT_BASE_CTL)
108 #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)
109 #define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2)
110 #define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3)
111 #define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET
112
113 #define IPT_CONTINUE XT_CONTINUE
114 #define IPT_RETURN XT_RETURN
115
116 #include <linux/netfilter/xt_tcpudp.h>
117 #define ipt_udp xt_udp
118 #define ipt_tcp xt_tcp
119
120 #define IPT_TCP_INV_SRCPT XT_TCP_INV_SRCPT
121 #define IPT_TCP_INV_DSTPT XT_TCP_INV_DSTPT
122 #define IPT_TCP_INV_FLAGS XT_TCP_INV_FLAGS
123 #define IPT_TCP_INV_OPTION XT_TCP_INV_OPTION
124 #define IPT_TCP_INV_MASK XT_TCP_INV_MASK
125
126 #define IPT_UDP_INV_SRCPT XT_UDP_INV_SRCPT
127 #define IPT_UDP_INV_DSTPT XT_UDP_INV_DSTPT
128 #define IPT_UDP_INV_MASK XT_UDP_INV_MASK
129
130 /* ICMP matching stuff */
131 struct ipt_icmp
132 {
133 u_int8_t type; /* type to match */
134 u_int8_t code[2]; /* range of code */
135 u_int8_t invflags; /* Inverse flags */
136 };
137
138 /* Values for "inv" field for struct ipt_icmp. */
139 #define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */
140
141 /* The argument to IPT_SO_GET_INFO */
142 struct ipt_getinfo
143 {
144 /* Which table: caller fills this in. */
145 char name[IPT_TABLE_MAXNAMELEN];
146
147 /* Kernel fills these in. */
148 /* Which hook entry points are valid: bitmask */
149 unsigned int valid_hooks;
150
151 /* Hook entry points: one per netfilter hook. */
152 unsigned int hook_entry[NF_INET_NUMHOOKS];
153
154 /* Underflow points. */
155 unsigned int underflow[NF_INET_NUMHOOKS];
156
157 /* Number of entries */
158 unsigned int num_entries;
159
160 /* Size of entries. */
161 unsigned int size;
162 };
163
164 /* The argument to IPT_SO_SET_REPLACE. */
165 struct ipt_replace
166 {
167 /* Which table. */
168 char name[IPT_TABLE_MAXNAMELEN];
169
170 /* Which hook entry points are valid: bitmask. You can't
171 change this. */
172 unsigned int valid_hooks;
173
174 /* Number of entries */
175 unsigned int num_entries;
176
177 /* Total size of new entries */
178 unsigned int size;
179
180 /* Hook entry points. */
181 unsigned int hook_entry[NF_INET_NUMHOOKS];
182
183 /* Underflow points. */
184 unsigned int underflow[NF_INET_NUMHOOKS];
185
186 /* Information about old entries: */
187 /* Number of counters (must be equal to current number of entries). */
188 unsigned int num_counters;
189 /* The old entries' counters. */
190 struct xt_counters *counters;
191
192 /* The entries (hang off end: not really an array). */
193 struct ipt_entry entries[0];
194 };
195
196 /* The argument to IPT_SO_ADD_COUNTERS. */
197 #define ipt_counters_info xt_counters_info
198
199 /* The argument to IPT_SO_GET_ENTRIES. */
200 struct ipt_get_entries
201 {
202 /* Which table: user fills this in. */
203 char name[IPT_TABLE_MAXNAMELEN];
204
205 /* User fills this in: total entry size. */
206 unsigned int size;
207
208 /* The entries. */
209 struct ipt_entry entrytable[0];
210 };
211
212 /* Standard return verdict, or do jump. */
213 #define IPT_STANDARD_TARGET XT_STANDARD_TARGET
214 /* Error verdict. */
215 #define IPT_ERROR_TARGET XT_ERROR_TARGET
216
217 /* Helper functions */
218 static __inline__ struct ipt_entry_target *
ipt_get_target(struct ipt_entry * e)219 ipt_get_target(struct ipt_entry *e)
220 {
221 return (void *)e + e->target_offset;
222 }
223
224 /* fn returns 0 to continue iteration */
225 #define IPT_MATCH_ITERATE(e, fn, args...) \
226 XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
227
228 /* fn returns 0 to continue iteration */
229 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
230 XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
231
232 /*
233 * Main firewall chains definitions and global var's definitions.
234 */
235 #endif /* _IPTABLES_H */
236