xref: /freebsd/sys/netinet/ip_fw.h (revision 641a6cfb86023499caafe26a4d821a0b885cf00b)
1 /*-
2  * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 
28 #ifndef _IPFW2_H
29 #define _IPFW2_H
30 
31 /*
32  * The default rule number.  By the design of ip_fw, the default rule
33  * is the last one, so its number can also serve as the highest number
34  * allowed for a rule.  The ip_fw code relies on both meanings of this
35  * constant.
36  */
37 #define	IPFW_DEFAULT_RULE	65535
38 
39 /*
40  * Default number of ipfw tables.
41  */
42 #define	IPFW_TABLES_MAX		65535
43 #define	IPFW_TABLES_DEFAULT	128
44 
45 /*
46  * Most commands (queue, pipe, tag, untag, limit...) can have a 16-bit
47  * argument between 1 and 65534. The value 0 is unused, the value
48  * 65535 (IP_FW_TABLEARG) is used to represent 'tablearg', i.e. the
49  * can be 1..65534, or 65535 to indicate the use of a 'tablearg'
50  * result of the most recent table() lookup.
51  * Note that 16bit is only a historical limit, resulting from
52  * the use of a 16-bit fields for that value. In reality, we can have
53  * 2^32 pipes, queues, tag values and so on, and use 0 as a tablearg.
54  */
55 #define	IPFW_ARG_MIN		1
56 #define	IPFW_ARG_MAX		65534
57 #define IP_FW_TABLEARG		65535	/* XXX should use 0 */
58 
59 /*
60  * Number of entries in the call stack of the call/return commands.
61  * Call stack currently is an uint16_t array with rule numbers.
62  */
63 #define	IPFW_CALLSTACK_SIZE	16
64 
65 /* IP_FW3 header/opcodes */
66 typedef struct _ip_fw3_opheader {
67 	uint16_t opcode;	/* Operation opcode */
68 	uint16_t reserved[3];	/* Align to 64-bit boundary */
69 } ip_fw3_opheader;
70 
71 
72 /* IPFW extented tables support */
73 #define	IP_FW_TABLE_XADD	86	/* add entry */
74 #define	IP_FW_TABLE_XDEL	87	/* delete entry */
75 #define	IP_FW_TABLE_XGETSIZE	88	/* get table size */
76 #define	IP_FW_TABLE_XLIST	89	/* list table contents */
77 
78 /*
79  * The kernel representation of ipfw rules is made of a list of
80  * 'instructions' (for all practical purposes equivalent to BPF
81  * instructions), which specify which fields of the packet
82  * (or its metadata) should be analysed.
83  *
84  * Each instruction is stored in a structure which begins with
85  * "ipfw_insn", and can contain extra fields depending on the
86  * instruction type (listed below).
87  * Note that the code is written so that individual instructions
88  * have a size which is a multiple of 32 bits. This means that, if
89  * such structures contain pointers or other 64-bit entities,
90  * (there is just one instance now) they may end up unaligned on
91  * 64-bit architectures, so the must be handled with care.
92  *
93  * "enum ipfw_opcodes" are the opcodes supported. We can have up
94  * to 256 different opcodes. When adding new opcodes, they should
95  * be appended to the end of the opcode list before O_LAST_OPCODE,
96  * this will prevent the ABI from being broken, otherwise users
97  * will have to recompile ipfw(8) when they update the kernel.
98  */
99 
100 enum ipfw_opcodes {		/* arguments (4 byte each)	*/
101 	O_NOP,
102 
103 	O_IP_SRC,		/* u32 = IP			*/
104 	O_IP_SRC_MASK,		/* ip = IP/mask			*/
105 	O_IP_SRC_ME,		/* none				*/
106 	O_IP_SRC_SET,		/* u32=base, arg1=len, bitmap	*/
107 
108 	O_IP_DST,		/* u32 = IP			*/
109 	O_IP_DST_MASK,		/* ip = IP/mask			*/
110 	O_IP_DST_ME,		/* none				*/
111 	O_IP_DST_SET,		/* u32=base, arg1=len, bitmap	*/
112 
113 	O_IP_SRCPORT,		/* (n)port list:mask 4 byte ea	*/
114 	O_IP_DSTPORT,		/* (n)port list:mask 4 byte ea	*/
115 	O_PROTO,		/* arg1=protocol		*/
116 
117 	O_MACADDR2,		/* 2 mac addr:mask		*/
118 	O_MAC_TYPE,		/* same as srcport		*/
119 
120 	O_LAYER2,		/* none				*/
121 	O_IN,			/* none				*/
122 	O_FRAG,			/* none				*/
123 
124 	O_RECV,			/* none				*/
125 	O_XMIT,			/* none				*/
126 	O_VIA,			/* none				*/
127 
128 	O_IPOPT,		/* arg1 = 2*u8 bitmap		*/
129 	O_IPLEN,		/* arg1 = len			*/
130 	O_IPID,			/* arg1 = id			*/
131 
132 	O_IPTOS,		/* arg1 = id			*/
133 	O_IPPRECEDENCE,		/* arg1 = precedence << 5	*/
134 	O_IPTTL,		/* arg1 = TTL			*/
135 
136 	O_IPVER,		/* arg1 = version		*/
137 	O_UID,			/* u32 = id			*/
138 	O_GID,			/* u32 = id			*/
139 	O_ESTAB,		/* none (tcp established)	*/
140 	O_TCPFLAGS,		/* arg1 = 2*u8 bitmap		*/
141 	O_TCPWIN,		/* arg1 = desired win		*/
142 	O_TCPSEQ,		/* u32 = desired seq.		*/
143 	O_TCPACK,		/* u32 = desired seq.		*/
144 	O_ICMPTYPE,		/* u32 = icmp bitmap		*/
145 	O_TCPOPTS,		/* arg1 = 2*u8 bitmap		*/
146 
147 	O_VERREVPATH,		/* none				*/
148 	O_VERSRCREACH,		/* none				*/
149 
150 	O_PROBE_STATE,		/* none				*/
151 	O_KEEP_STATE,		/* none				*/
152 	O_LIMIT,		/* ipfw_insn_limit		*/
153 	O_LIMIT_PARENT,		/* dyn_type, not an opcode.	*/
154 
155 	/*
156 	 * These are really 'actions'.
157 	 */
158 
159 	O_LOG,			/* ipfw_insn_log		*/
160 	O_PROB,			/* u32 = match probability	*/
161 
162 	O_CHECK_STATE,		/* none				*/
163 	O_ACCEPT,		/* none				*/
164 	O_DENY,			/* none 			*/
165 	O_REJECT,		/* arg1=icmp arg (same as deny)	*/
166 	O_COUNT,		/* none				*/
167 	O_SKIPTO,		/* arg1=next rule number	*/
168 	O_PIPE,			/* arg1=pipe number		*/
169 	O_QUEUE,		/* arg1=queue number		*/
170 	O_DIVERT,		/* arg1=port number		*/
171 	O_TEE,			/* arg1=port number		*/
172 	O_FORWARD_IP,		/* fwd sockaddr			*/
173 	O_FORWARD_MAC,		/* fwd mac			*/
174 	O_NAT,                  /* nope                         */
175 	O_REASS,                /* none                         */
176 
177 	/*
178 	 * More opcodes.
179 	 */
180 	O_IPSEC,		/* has ipsec history 		*/
181 	O_IP_SRC_LOOKUP,	/* arg1=table number, u32=value	*/
182 	O_IP_DST_LOOKUP,	/* arg1=table number, u32=value	*/
183 	O_ANTISPOOF,		/* none				*/
184 	O_JAIL,			/* u32 = id			*/
185 	O_ALTQ,			/* u32 = altq classif. qid	*/
186 	O_DIVERTED,		/* arg1=bitmap (1:loop, 2:out)	*/
187 	O_TCPDATALEN,		/* arg1 = tcp data len		*/
188 	O_IP6_SRC,		/* address without mask		*/
189 	O_IP6_SRC_ME,		/* my addresses			*/
190 	O_IP6_SRC_MASK,		/* address with the mask	*/
191 	O_IP6_DST,
192 	O_IP6_DST_ME,
193 	O_IP6_DST_MASK,
194 	O_FLOW6ID,		/* for flow id tag in the ipv6 pkt */
195 	O_ICMP6TYPE,		/* icmp6 packet type filtering	*/
196 	O_EXT_HDR,		/* filtering for ipv6 extension header */
197 	O_IP6,
198 
199 	/*
200 	 * actions for ng_ipfw
201 	 */
202 	O_NETGRAPH,		/* send to ng_ipfw		*/
203 	O_NGTEE,		/* copy to ng_ipfw		*/
204 
205 	O_IP4,
206 
207 	O_UNREACH6,		/* arg1=icmpv6 code arg (deny)  */
208 
209 	O_TAG,   		/* arg1=tag number */
210 	O_TAGGED,		/* arg1=tag number */
211 
212 	O_SETFIB,		/* arg1=FIB number */
213 	O_FIB,			/* arg1=FIB desired fib number */
214 
215 	O_SOCKARG,		/* socket argument */
216 
217 	O_CALLRETURN,		/* arg1=called rule number */
218 
219 	O_FORWARD_IP6,		/* fwd sockaddr_in6             */
220 
221 	O_LAST_OPCODE		/* not an opcode!		*/
222 };
223 
224 
225 /*
226  * The extension header are filtered only for presence using a bit
227  * vector with a flag for each header.
228  */
229 #define EXT_FRAGMENT	0x1
230 #define EXT_HOPOPTS	0x2
231 #define EXT_ROUTING	0x4
232 #define EXT_AH		0x8
233 #define EXT_ESP		0x10
234 #define EXT_DSTOPTS	0x20
235 #define EXT_RTHDR0		0x40
236 #define EXT_RTHDR2		0x80
237 
238 /*
239  * Template for instructions.
240  *
241  * ipfw_insn is used for all instructions which require no operands,
242  * a single 16-bit value (arg1), or a couple of 8-bit values.
243  *
244  * For other instructions which require different/larger arguments
245  * we have derived structures, ipfw_insn_*.
246  *
247  * The size of the instruction (in 32-bit words) is in the low
248  * 6 bits of "len". The 2 remaining bits are used to implement
249  * NOT and OR on individual instructions. Given a type, you can
250  * compute the length to be put in "len" using F_INSN_SIZE(t)
251  *
252  * F_NOT	negates the match result of the instruction.
253  *
254  * F_OR		is used to build or blocks. By default, instructions
255  *		are evaluated as part of a logical AND. An "or" block
256  *		{ X or Y or Z } contains F_OR set in all but the last
257  *		instruction of the block. A match will cause the code
258  *		to skip past the last instruction of the block.
259  *
260  * NOTA BENE: in a couple of places we assume that
261  *	sizeof(ipfw_insn) == sizeof(u_int32_t)
262  * this needs to be fixed.
263  *
264  */
265 typedef struct	_ipfw_insn {	/* template for instructions */
266 	u_int8_t 	opcode;
267 	u_int8_t	len;	/* number of 32-bit words */
268 #define	F_NOT		0x80
269 #define	F_OR		0x40
270 #define	F_LEN_MASK	0x3f
271 #define	F_LEN(cmd)	((cmd)->len & F_LEN_MASK)
272 
273 	u_int16_t	arg1;
274 } ipfw_insn;
275 
276 /*
277  * The F_INSN_SIZE(type) computes the size, in 4-byte words, of
278  * a given type.
279  */
280 #define	F_INSN_SIZE(t)	((sizeof (t))/sizeof(u_int32_t))
281 
282 /*
283  * This is used to store an array of 16-bit entries (ports etc.)
284  */
285 typedef struct	_ipfw_insn_u16 {
286 	ipfw_insn o;
287 	u_int16_t ports[2];	/* there may be more */
288 } ipfw_insn_u16;
289 
290 /*
291  * This is used to store an array of 32-bit entries
292  * (uid, single IPv4 addresses etc.)
293  */
294 typedef struct	_ipfw_insn_u32 {
295 	ipfw_insn o;
296 	u_int32_t d[1];	/* one or more */
297 } ipfw_insn_u32;
298 
299 /*
300  * This is used to store IP addr-mask pairs.
301  */
302 typedef struct	_ipfw_insn_ip {
303 	ipfw_insn o;
304 	struct in_addr	addr;
305 	struct in_addr	mask;
306 } ipfw_insn_ip;
307 
308 /*
309  * This is used to forward to a given address (ip).
310  */
311 typedef struct  _ipfw_insn_sa {
312 	ipfw_insn o;
313 	struct sockaddr_in sa;
314 } ipfw_insn_sa;
315 
316 /*
317  * This is used to forward to a given address (ipv6).
318  */
319 typedef struct _ipfw_insn_sa6 {
320 	ipfw_insn o;
321 	struct sockaddr_in6 sa;
322 } ipfw_insn_sa6;
323 
324 /*
325  * This is used for MAC addr-mask pairs.
326  */
327 typedef struct	_ipfw_insn_mac {
328 	ipfw_insn o;
329 	u_char addr[12];	/* dst[6] + src[6] */
330 	u_char mask[12];	/* dst[6] + src[6] */
331 } ipfw_insn_mac;
332 
333 /*
334  * This is used for interface match rules (recv xx, xmit xx).
335  */
336 typedef struct	_ipfw_insn_if {
337 	ipfw_insn o;
338 	union {
339 		struct in_addr ip;
340 		int glob;
341 	} p;
342 	char name[IFNAMSIZ];
343 } ipfw_insn_if;
344 
345 /*
346  * This is used for storing an altq queue id number.
347  */
348 typedef struct _ipfw_insn_altq {
349 	ipfw_insn	o;
350 	u_int32_t	qid;
351 } ipfw_insn_altq;
352 
353 /*
354  * This is used for limit rules.
355  */
356 typedef struct	_ipfw_insn_limit {
357 	ipfw_insn o;
358 	u_int8_t _pad;
359 	u_int8_t limit_mask;	/* combination of DYN_* below	*/
360 #define	DYN_SRC_ADDR	0x1
361 #define	DYN_SRC_PORT	0x2
362 #define	DYN_DST_ADDR	0x4
363 #define	DYN_DST_PORT	0x8
364 
365 	u_int16_t conn_limit;
366 } ipfw_insn_limit;
367 
368 /*
369  * This is used for log instructions.
370  */
371 typedef struct  _ipfw_insn_log {
372         ipfw_insn o;
373 	u_int32_t max_log;	/* how many do we log -- 0 = all */
374 	u_int32_t log_left;	/* how many left to log 	*/
375 } ipfw_insn_log;
376 
377 /*
378  * Data structures required by both ipfw(8) and ipfw(4) but not part of the
379  * management API are protected by IPFW_INTERNAL.
380  */
381 #ifdef IPFW_INTERNAL
382 /* Server pool support (LSNAT). */
383 struct cfg_spool {
384 	LIST_ENTRY(cfg_spool)   _next;          /* chain of spool instances */
385 	struct in_addr          addr;
386 	u_short                 port;
387 };
388 #endif
389 
390 /* Redirect modes id. */
391 #define REDIR_ADDR      0x01
392 #define REDIR_PORT      0x02
393 #define REDIR_PROTO     0x04
394 
395 #ifdef IPFW_INTERNAL
396 /* Nat redirect configuration. */
397 struct cfg_redir {
398 	LIST_ENTRY(cfg_redir)   _next;          /* chain of redir instances */
399 	u_int16_t               mode;           /* type of redirect mode */
400 	struct in_addr	        laddr;          /* local ip address */
401 	struct in_addr	        paddr;          /* public ip address */
402 	struct in_addr	        raddr;          /* remote ip address */
403 	u_short                 lport;          /* local port */
404 	u_short                 pport;          /* public port */
405 	u_short                 rport;          /* remote port  */
406 	u_short                 pport_cnt;      /* number of public ports */
407 	u_short                 rport_cnt;      /* number of remote ports */
408 	int                     proto;          /* protocol: tcp/udp */
409 	struct alias_link       **alink;
410 	/* num of entry in spool chain */
411 	u_int16_t               spool_cnt;
412 	/* chain of spool instances */
413 	LIST_HEAD(spool_chain, cfg_spool) spool_chain;
414 };
415 #endif
416 
417 #ifdef IPFW_INTERNAL
418 /* Nat configuration data struct. */
419 struct cfg_nat {
420 	/* chain of nat instances */
421 	LIST_ENTRY(cfg_nat)     _next;
422 	int                     id;                     /* nat id */
423 	struct in_addr          ip;                     /* nat ip address */
424 	char                    if_name[IF_NAMESIZE];   /* interface name */
425 	int                     mode;                   /* aliasing mode */
426 	struct libalias	        *lib;                   /* libalias instance */
427 	/* number of entry in spool chain */
428 	int                     redir_cnt;
429 	/* chain of redir instances */
430 	LIST_HEAD(redir_chain, cfg_redir) redir_chain;
431 };
432 #endif
433 
434 #define SOF_NAT         sizeof(struct cfg_nat)
435 #define SOF_REDIR       sizeof(struct cfg_redir)
436 #define SOF_SPOOL       sizeof(struct cfg_spool)
437 
438 /* Nat command. */
439 typedef struct	_ipfw_insn_nat {
440  	ipfw_insn	o;
441  	struct cfg_nat *nat;
442 } ipfw_insn_nat;
443 
444 /* Apply ipv6 mask on ipv6 addr */
445 #define APPLY_MASK(addr,mask)                          \
446     (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \
447     (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \
448     (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \
449     (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3];
450 
451 /* Structure for ipv6 */
452 typedef struct _ipfw_insn_ip6 {
453        ipfw_insn o;
454        struct in6_addr addr6;
455        struct in6_addr mask6;
456 } ipfw_insn_ip6;
457 
458 /* Used to support icmp6 types */
459 typedef struct _ipfw_insn_icmp6 {
460        ipfw_insn o;
461        uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h
462                        *     define ICMP6_MAXTYPE
463                        *     as follows: n = ICMP6_MAXTYPE/32 + 1
464                         *     Actually is 203
465                        */
466 } ipfw_insn_icmp6;
467 
468 /*
469  * Here we have the structure representing an ipfw rule.
470  *
471  * It starts with a general area (with link fields and counters)
472  * followed by an array of one or more instructions, which the code
473  * accesses as an array of 32-bit values.
474  *
475  * Given a rule pointer  r:
476  *
477  *  r->cmd		is the start of the first instruction.
478  *  ACTION_PTR(r)	is the start of the first action (things to do
479  *			once a rule matched).
480  *
481  * When assembling instruction, remember the following:
482  *
483  *  + if a rule has a "keep-state" (or "limit") option, then the
484  *	first instruction (at r->cmd) MUST BE an O_PROBE_STATE
485  *  + if a rule has a "log" option, then the first action
486  *	(at ACTION_PTR(r)) MUST be O_LOG
487  *  + if a rule has an "altq" option, it comes after "log"
488  *  + if a rule has an O_TAG option, it comes after "log" and "altq"
489  *
490  * NOTE: we use a simple linked list of rules because we never need
491  * 	to delete a rule without scanning the list. We do not use
492  *	queue(3) macros for portability and readability.
493  */
494 
495 struct ip_fw {
496 	struct ip_fw	*x_next;	/* linked list of rules		*/
497 	struct ip_fw	*next_rule;	/* ptr to next [skipto] rule	*/
498 	/* 'next_rule' is used to pass up 'set_disable' status		*/
499 
500 	uint16_t	act_ofs;	/* offset of action in 32-bit units */
501 	uint16_t	cmd_len;	/* # of 32-bit words in cmd	*/
502 	uint16_t	rulenum;	/* rule number			*/
503 	uint8_t	set;		/* rule set (0..31)		*/
504 #define	RESVD_SET	31	/* set for default and persistent rules */
505 	uint8_t		_pad;		/* padding			*/
506 	uint32_t	id;		/* rule id */
507 
508 	/* These fields are present in all rules.			*/
509 	uint64_t	pcnt;		/* Packet counter		*/
510 	uint64_t	bcnt;		/* Byte counter			*/
511 	uint32_t	timestamp;	/* tv_sec of last match		*/
512 
513 	ipfw_insn	cmd[1];		/* storage for commands		*/
514 };
515 
516 #define ACTION_PTR(rule)				\
517 	(ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) )
518 
519 #define RULESIZE(rule)  (sizeof(struct ip_fw) + \
520 	((struct ip_fw *)(rule))->cmd_len * 4 - 4)
521 
522 #if 1 // should be moved to in.h
523 /*
524  * This structure is used as a flow mask and a flow id for various
525  * parts of the code.
526  * addr_type is used in userland and kernel to mark the address type.
527  * fib is used in the kernel to record the fib in use.
528  * _flags is used in the kernel to store tcp flags for dynamic rules.
529  */
530 struct ipfw_flow_id {
531 	uint32_t	dst_ip;
532 	uint32_t	src_ip;
533 	uint16_t	dst_port;
534 	uint16_t	src_port;
535 	uint8_t		fib;
536 	uint8_t		proto;
537 	uint8_t		_flags;	/* protocol-specific flags */
538 	uint8_t		addr_type; /* 4=ip4, 6=ip6, 1=ether ? */
539 	struct in6_addr dst_ip6;
540 	struct in6_addr src_ip6;
541 	uint32_t	flow_id6;
542 	uint32_t	extra; /* queue/pipe or frag_id */
543 };
544 #endif
545 
546 #define IS_IP6_FLOW_ID(id)	((id)->addr_type == 6)
547 
548 /*
549  * Dynamic ipfw rule.
550  */
551 typedef struct _ipfw_dyn_rule ipfw_dyn_rule;
552 
553 struct _ipfw_dyn_rule {
554 	ipfw_dyn_rule	*next;		/* linked list of rules.	*/
555 	struct ip_fw *rule;		/* pointer to rule		*/
556 	/* 'rule' is used to pass up the rule number (from the parent)	*/
557 
558 	ipfw_dyn_rule *parent;		/* pointer to parent rule	*/
559 	u_int64_t	pcnt;		/* packet match counter		*/
560 	u_int64_t	bcnt;		/* byte match counter		*/
561 	struct ipfw_flow_id id;		/* (masked) flow id		*/
562 	u_int32_t	expire;		/* expire time			*/
563 	u_int32_t	bucket;		/* which bucket in hash table	*/
564 	u_int32_t	state;		/* state of this rule (typically a
565 					 * combination of TCP flags)
566 					 */
567 	u_int32_t	ack_fwd;	/* most recent ACKs in forward	*/
568 	u_int32_t	ack_rev;	/* and reverse directions (used	*/
569 					/* to generate keepalives)	*/
570 	u_int16_t	dyn_type;	/* rule type			*/
571 	u_int16_t	count;		/* refcount			*/
572 };
573 
574 /*
575  * Definitions for IP option names.
576  */
577 #define	IP_FW_IPOPT_LSRR	0x01
578 #define	IP_FW_IPOPT_SSRR	0x02
579 #define	IP_FW_IPOPT_RR		0x04
580 #define	IP_FW_IPOPT_TS		0x08
581 
582 /*
583  * Definitions for TCP option names.
584  */
585 #define	IP_FW_TCPOPT_MSS	0x01
586 #define	IP_FW_TCPOPT_WINDOW	0x02
587 #define	IP_FW_TCPOPT_SACK	0x04
588 #define	IP_FW_TCPOPT_TS		0x08
589 #define	IP_FW_TCPOPT_CC		0x10
590 
591 #define	ICMP_REJECT_RST		0x100	/* fake ICMP code (send a TCP RST) */
592 #define	ICMP6_UNREACH_RST	0x100	/* fake ICMPv6 code (send a TCP RST) */
593 
594 /*
595  * These are used for lookup tables.
596  */
597 
598 #define	IPFW_TABLE_CIDR		1	/* Table for holding IPv4/IPv6 prefixes */
599 #define	IPFW_TABLE_INTERFACE	2	/* Table for holding interface names */
600 #define	IPFW_TABLE_MAXTYPE	2	/* Maximum valid number */
601 
602 typedef struct	_ipfw_table_entry {
603 	in_addr_t	addr;		/* network address		*/
604 	u_int32_t	value;		/* value			*/
605 	u_int16_t	tbl;		/* table number			*/
606 	u_int8_t	masklen;	/* mask length			*/
607 } ipfw_table_entry;
608 
609 typedef struct	_ipfw_table_xentry {
610 	uint16_t	len;		/* Total entry length		*/
611 	uint8_t		type;		/* entry type			*/
612 	uint8_t		masklen;	/* mask length			*/
613 	uint16_t	tbl;		/* table number			*/
614 	uint32_t	value;		/* value			*/
615 	union {
616 		/* Longest field needs to be aligned by 4-byte boundary	*/
617 		struct in6_addr	addr6;	/* IPv6 address 		*/
618 		char	iface[IF_NAMESIZE];	/* interface name	*/
619 	} k;
620 } ipfw_table_xentry;
621 
622 typedef struct	_ipfw_table {
623 	u_int32_t	size;		/* size of entries in bytes	*/
624 	u_int32_t	cnt;		/* # of entries			*/
625 	u_int16_t	tbl;		/* table number			*/
626 	ipfw_table_entry ent[0];	/* entries			*/
627 } ipfw_table;
628 
629 typedef struct	_ipfw_xtable {
630 	ip_fw3_opheader	opheader;	/* eXtended tables are controlled via IP_FW3 */
631 	uint32_t	size;		/* size of entries in bytes	*/
632 	uint32_t	cnt;		/* # of entries			*/
633 	uint16_t	tbl;		/* table number			*/
634 	uint8_t		type;		/* table type			*/
635 	ipfw_table_xentry xent[0];	/* entries			*/
636 } ipfw_xtable;
637 
638 #endif /* _IPFW2_H */
639