2 * 25-Jul-1998 Major changes to allow for ip chain table
4 * 3-Jan-2000 Named tables to allow packet selection for different uses.
8 * Format of an IP firewall descriptor
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.
18 #include <linux/compiler.h>
19 #include <linux/netfilter_ipv4.h>
21 #define IPT_FUNCTION_MAXNAMELEN 30
22 #define IPT_TABLE_MAXNAMELEN 32
24 /* Yes, Virginia, you have to zero the padding. */
26 /* Source and destination IP addr */
27 struct in_addr src, dst;
28 /* Mask for src and dest IP addr */
29 struct in_addr smsk, dmsk;
30 char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
31 unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
33 /* Protocol, 0 = ANY */
42 struct ipt_entry_match
48 /* Used by userspace */
49 char name[IPT_FUNCTION_MAXNAMELEN-1];
56 /* Used inside the kernel */
57 struct ipt_match *match;
64 unsigned char data[0];
67 struct ipt_entry_target
71 u_int16_t target_size;
73 /* Used by userspace */
74 char name[IPT_FUNCTION_MAXNAMELEN-1];
79 u_int16_t target_size;
81 /* Used inside the kernel */
82 struct ipt_target *target;
86 u_int16_t target_size;
89 unsigned char data[0];
92 struct ipt_standard_target
94 struct ipt_entry_target target;
100 u_int64_t pcnt, bcnt; /* Packet and byte counters */
103 /* Values for "flag" field in struct ipt_ip (general ip structure). */
104 #define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
105 #define IPT_F_MASK 0x01 /* All possible flag bits mask. */
107 /* Values for "inv" field in struct ipt_ip. */
108 #define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
109 #define IPT_INV_VIA_OUT 0x02 /* Invert the sense of OUT IFACE */
110 #define IPT_INV_TOS 0x04 /* Invert the sense of TOS. */
111 #define IPT_INV_SRCIP 0x08 /* Invert the sense of SRC IP. */
112 #define IPT_INV_DSTIP 0x10 /* Invert the sense of DST OP. */
113 #define IPT_INV_FRAG 0x20 /* Invert the sense of FRAG. */
114 #define IPT_INV_PROTO 0x40 /* Invert the sense of PROTO. */
115 #define IPT_INV_MASK 0x7F /* All possible flag bits mask. */
117 /* This structure defines each of the firewall rules. Consists of 3
118 parts which are 1) general IP header stuff 2) match specific
119 stuff 3) the target to perform if the rule matches */
124 /* Mark with fields that we care about. */
125 unsigned int nfcache;
127 /* Size of ipt_entry + matches */
128 u_int16_t target_offset;
129 /* Size of ipt_entry + matches + target */
130 u_int16_t next_offset;
133 unsigned int comefrom;
135 /* Packet and byte counters. */
136 struct ipt_counters counters;
138 /* The matches (if any), then the target. */
139 unsigned char elems[0];
143 * New IP firewall options for [gs]etsockopt at the RAW IP level.
144 * Unlike BSD Linux inherits IP options so you don't have to use a raw
145 * socket for this. Instead we check rights in the calls. */
146 #define IPT_BASE_CTL 64 /* base for firewall socket options */
148 #define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
149 #define IPT_SO_SET_ADD_COUNTERS (IPT_BASE_CTL + 1)
150 #define IPT_SO_SET_MAX IPT_SO_SET_ADD_COUNTERS
152 #define IPT_SO_GET_INFO (IPT_BASE_CTL)
153 #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)
154 #define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2)
155 #define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3)
156 #define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET
158 /* CONTINUE verdict for targets */
159 #define IPT_CONTINUE 0xFFFFFFFF
161 /* For standard target */
162 #define IPT_RETURN (-NF_MAX_VERDICT - 1)
164 /* TCP matching stuff */
167 u_int16_t spts[2]; /* Source port range. */
168 u_int16_t dpts[2]; /* Destination port range. */
169 u_int8_t option; /* TCP Option iff non-zero*/
170 u_int8_t flg_mask; /* TCP flags mask byte */
171 u_int8_t flg_cmp; /* TCP flags compare byte */
172 u_int8_t invflags; /* Inverse flags */
175 /* Values for "inv" field in struct ipt_tcp. */
176 #define IPT_TCP_INV_SRCPT 0x01 /* Invert the sense of source ports. */
177 #define IPT_TCP_INV_DSTPT 0x02 /* Invert the sense of dest ports. */
178 #define IPT_TCP_INV_FLAGS 0x04 /* Invert the sense of TCP flags. */
179 #define IPT_TCP_INV_OPTION 0x08 /* Invert the sense of option test. */
180 #define IPT_TCP_INV_MASK 0x0F /* All possible flags. */
182 /* UDP matching stuff */
185 u_int16_t spts[2]; /* Source port range. */
186 u_int16_t dpts[2]; /* Destination port range. */
187 u_int8_t invflags; /* Inverse flags */
190 /* Values for "invflags" field in struct ipt_udp. */
191 #define IPT_UDP_INV_SRCPT 0x01 /* Invert the sense of source ports. */
192 #define IPT_UDP_INV_DSTPT 0x02 /* Invert the sense of dest ports. */
193 #define IPT_UDP_INV_MASK 0x03 /* All possible flags. */
195 /* ICMP matching stuff */
198 u_int8_t type; /* type to match */
199 u_int8_t code[2]; /* range of code */
200 u_int8_t invflags; /* Inverse flags */
203 /* Values for "inv" field for struct ipt_icmp. */
204 #define IPT_ICMP_INV 0x01 /* Invert the sense of type/code test */
206 /* The argument to IPT_SO_GET_INFO */
209 /* Which table: caller fills this in. */
210 char name[IPT_TABLE_MAXNAMELEN];
212 /* Kernel fills these in. */
213 /* Which hook entry points are valid: bitmask */
214 unsigned int valid_hooks;
216 /* Hook entry points: one per netfilter hook. */
217 unsigned int hook_entry[NF_IP_NUMHOOKS];
219 /* Underflow points. */
220 unsigned int underflow[NF_IP_NUMHOOKS];
222 /* Number of entries */
223 unsigned int num_entries;
225 /* Size of entries. */
229 /* The argument to IPT_SO_SET_REPLACE. */
233 char name[IPT_TABLE_MAXNAMELEN];
235 /* Which hook entry points are valid: bitmask. You can't
237 unsigned int valid_hooks;
239 /* Number of entries */
240 unsigned int num_entries;
242 /* Total size of new entries */
245 /* Hook entry points. */
246 unsigned int hook_entry[NF_IP_NUMHOOKS];
248 /* Underflow points. */
249 unsigned int underflow[NF_IP_NUMHOOKS];
251 /* Information about old entries: */
252 /* Number of counters (must be equal to current number of entries). */
253 unsigned int num_counters;
255 /* The old entries' counters. */
256 struct ipt_counters *counters;
258 /* The entries (hang off end: not really an array). */
259 struct ipt_entry entries[0];
262 /* The argument to IPT_SO_ADD_COUNTERS. */
263 struct ipt_counters_info
266 char name[IPT_TABLE_MAXNAMELEN];
268 unsigned int num_counters;
270 /* The counters (actually `number' of these). */
271 struct ipt_counters counters[0];
274 /* The argument to IPT_SO_GET_ENTRIES. */
275 struct ipt_get_entries
277 /* Which table: user fills this in. */
278 char name[IPT_TABLE_MAXNAMELEN];
280 /* User fills this in: total entry size. */
284 struct ipt_entry entrytable[0];
287 /* The argument to IPT_SO_GET_REVISION_*. Returns highest revision
288 * kernel supports, if >= revision. */
289 struct ipt_get_revision
291 char name[IPT_FUNCTION_MAXNAMELEN-1];
296 /* Standard return verdict, or do jump. */
297 #define IPT_STANDARD_TARGET ""
299 #define IPT_ERROR_TARGET "ERROR"
301 /* Helper functions */
302 static __inline__ struct ipt_entry_target *
303 ipt_get_target(struct ipt_entry *e)
305 return (void *)e + e->target_offset;
308 /* fn returns 0 to continue iteration */
309 #define IPT_MATCH_ITERATE(e, fn, args...) \
313 struct ipt_entry_match *__match; \
315 for (__i = sizeof(struct ipt_entry); \
316 __i < (e)->target_offset; \
317 __i += __match->u.match_size) { \
318 __match = (void *)(e) + __i; \
320 __ret = fn(__match , ## args); \
327 /* fn returns 0 to continue iteration */
328 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
332 struct ipt_entry *__entry; \
334 for (__i = 0; __i < (size); __i += __entry->next_offset) { \
335 __entry = (void *)(entries) + __i; \
337 __ret = fn(__entry , ## args); \
345 * Main firewall chains definitions and global var's definitions.
347 #endif /* _IPTABLES_H */