xref: /freebsd/sys/netinet/ip_fw.h (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e)
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_DSCP,			/* 2 u32 = DSCP mask */
222 	O_SETDSCP,		/* arg1=DSCP value */
223 
224 	O_LAST_OPCODE		/* not an opcode!		*/
225 };
226 
227 
228 /*
229  * The extension header are filtered only for presence using a bit
230  * vector with a flag for each header.
231  */
232 #define EXT_FRAGMENT	0x1
233 #define EXT_HOPOPTS	0x2
234 #define EXT_ROUTING	0x4
235 #define EXT_AH		0x8
236 #define EXT_ESP		0x10
237 #define EXT_DSTOPTS	0x20
238 #define EXT_RTHDR0		0x40
239 #define EXT_RTHDR2		0x80
240 
241 /*
242  * Template for instructions.
243  *
244  * ipfw_insn is used for all instructions which require no operands,
245  * a single 16-bit value (arg1), or a couple of 8-bit values.
246  *
247  * For other instructions which require different/larger arguments
248  * we have derived structures, ipfw_insn_*.
249  *
250  * The size of the instruction (in 32-bit words) is in the low
251  * 6 bits of "len". The 2 remaining bits are used to implement
252  * NOT and OR on individual instructions. Given a type, you can
253  * compute the length to be put in "len" using F_INSN_SIZE(t)
254  *
255  * F_NOT	negates the match result of the instruction.
256  *
257  * F_OR		is used to build or blocks. By default, instructions
258  *		are evaluated as part of a logical AND. An "or" block
259  *		{ X or Y or Z } contains F_OR set in all but the last
260  *		instruction of the block. A match will cause the code
261  *		to skip past the last instruction of the block.
262  *
263  * NOTA BENE: in a couple of places we assume that
264  *	sizeof(ipfw_insn) == sizeof(u_int32_t)
265  * this needs to be fixed.
266  *
267  */
268 typedef struct	_ipfw_insn {	/* template for instructions */
269 	u_int8_t 	opcode;
270 	u_int8_t	len;	/* number of 32-bit words */
271 #define	F_NOT		0x80
272 #define	F_OR		0x40
273 #define	F_LEN_MASK	0x3f
274 #define	F_LEN(cmd)	((cmd)->len & F_LEN_MASK)
275 
276 	u_int16_t	arg1;
277 } ipfw_insn;
278 
279 /*
280  * The F_INSN_SIZE(type) computes the size, in 4-byte words, of
281  * a given type.
282  */
283 #define	F_INSN_SIZE(t)	((sizeof (t))/sizeof(u_int32_t))
284 
285 /*
286  * This is used to store an array of 16-bit entries (ports etc.)
287  */
288 typedef struct	_ipfw_insn_u16 {
289 	ipfw_insn o;
290 	u_int16_t ports[2];	/* there may be more */
291 } ipfw_insn_u16;
292 
293 /*
294  * This is used to store an array of 32-bit entries
295  * (uid, single IPv4 addresses etc.)
296  */
297 typedef struct	_ipfw_insn_u32 {
298 	ipfw_insn o;
299 	u_int32_t d[1];	/* one or more */
300 } ipfw_insn_u32;
301 
302 /*
303  * This is used to store IP addr-mask pairs.
304  */
305 typedef struct	_ipfw_insn_ip {
306 	ipfw_insn o;
307 	struct in_addr	addr;
308 	struct in_addr	mask;
309 } ipfw_insn_ip;
310 
311 /*
312  * This is used to forward to a given address (ip).
313  */
314 typedef struct  _ipfw_insn_sa {
315 	ipfw_insn o;
316 	struct sockaddr_in sa;
317 } ipfw_insn_sa;
318 
319 /*
320  * This is used to forward to a given address (ipv6).
321  */
322 typedef struct _ipfw_insn_sa6 {
323 	ipfw_insn o;
324 	struct sockaddr_in6 sa;
325 } ipfw_insn_sa6;
326 
327 /*
328  * This is used for MAC addr-mask pairs.
329  */
330 typedef struct	_ipfw_insn_mac {
331 	ipfw_insn o;
332 	u_char addr[12];	/* dst[6] + src[6] */
333 	u_char mask[12];	/* dst[6] + src[6] */
334 } ipfw_insn_mac;
335 
336 /*
337  * This is used for interface match rules (recv xx, xmit xx).
338  */
339 typedef struct	_ipfw_insn_if {
340 	ipfw_insn o;
341 	union {
342 		struct in_addr ip;
343 		int glob;
344 	} p;
345 	char name[IFNAMSIZ];
346 } ipfw_insn_if;
347 
348 /*
349  * This is used for storing an altq queue id number.
350  */
351 typedef struct _ipfw_insn_altq {
352 	ipfw_insn	o;
353 	u_int32_t	qid;
354 } ipfw_insn_altq;
355 
356 /*
357  * This is used for limit rules.
358  */
359 typedef struct	_ipfw_insn_limit {
360 	ipfw_insn o;
361 	u_int8_t _pad;
362 	u_int8_t limit_mask;	/* combination of DYN_* below	*/
363 #define	DYN_SRC_ADDR	0x1
364 #define	DYN_SRC_PORT	0x2
365 #define	DYN_DST_ADDR	0x4
366 #define	DYN_DST_PORT	0x8
367 
368 	u_int16_t conn_limit;
369 } ipfw_insn_limit;
370 
371 /*
372  * This is used for log instructions.
373  */
374 typedef struct  _ipfw_insn_log {
375         ipfw_insn o;
376 	u_int32_t max_log;	/* how many do we log -- 0 = all */
377 	u_int32_t log_left;	/* how many left to log 	*/
378 } ipfw_insn_log;
379 
380 /*
381  * Data structures required by both ipfw(8) and ipfw(4) but not part of the
382  * management API are protected by IPFW_INTERNAL.
383  */
384 #ifdef IPFW_INTERNAL
385 /* Server pool support (LSNAT). */
386 struct cfg_spool {
387 	LIST_ENTRY(cfg_spool)   _next;          /* chain of spool instances */
388 	struct in_addr          addr;
389 	u_short                 port;
390 };
391 #endif
392 
393 /* Redirect modes id. */
394 #define REDIR_ADDR      0x01
395 #define REDIR_PORT      0x02
396 #define REDIR_PROTO     0x04
397 
398 #ifdef IPFW_INTERNAL
399 /* Nat redirect configuration. */
400 struct cfg_redir {
401 	LIST_ENTRY(cfg_redir)   _next;          /* chain of redir instances */
402 	u_int16_t               mode;           /* type of redirect mode */
403 	struct in_addr	        laddr;          /* local ip address */
404 	struct in_addr	        paddr;          /* public ip address */
405 	struct in_addr	        raddr;          /* remote ip address */
406 	u_short                 lport;          /* local port */
407 	u_short                 pport;          /* public port */
408 	u_short                 rport;          /* remote port  */
409 	u_short                 pport_cnt;      /* number of public ports */
410 	u_short                 rport_cnt;      /* number of remote ports */
411 	int                     proto;          /* protocol: tcp/udp */
412 	struct alias_link       **alink;
413 	/* num of entry in spool chain */
414 	u_int16_t               spool_cnt;
415 	/* chain of spool instances */
416 	LIST_HEAD(spool_chain, cfg_spool) spool_chain;
417 };
418 #endif
419 
420 #ifdef IPFW_INTERNAL
421 /* Nat configuration data struct. */
422 struct cfg_nat {
423 	/* chain of nat instances */
424 	LIST_ENTRY(cfg_nat)     _next;
425 	int                     id;                     /* nat id */
426 	struct in_addr          ip;                     /* nat ip address */
427 	char                    if_name[IF_NAMESIZE];   /* interface name */
428 	int                     mode;                   /* aliasing mode */
429 	struct libalias	        *lib;                   /* libalias instance */
430 	/* number of entry in spool chain */
431 	int                     redir_cnt;
432 	/* chain of redir instances */
433 	LIST_HEAD(redir_chain, cfg_redir) redir_chain;
434 };
435 #endif
436 
437 #define SOF_NAT         sizeof(struct cfg_nat)
438 #define SOF_REDIR       sizeof(struct cfg_redir)
439 #define SOF_SPOOL       sizeof(struct cfg_spool)
440 
441 /* Nat command. */
442 typedef struct	_ipfw_insn_nat {
443  	ipfw_insn	o;
444  	struct cfg_nat *nat;
445 } ipfw_insn_nat;
446 
447 /* Apply ipv6 mask on ipv6 addr */
448 #define APPLY_MASK(addr,mask)                          \
449     (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \
450     (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \
451     (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \
452     (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3];
453 
454 /* Structure for ipv6 */
455 typedef struct _ipfw_insn_ip6 {
456        ipfw_insn o;
457        struct in6_addr addr6;
458        struct in6_addr mask6;
459 } ipfw_insn_ip6;
460 
461 /* Used to support icmp6 types */
462 typedef struct _ipfw_insn_icmp6 {
463        ipfw_insn o;
464        uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h
465                        *     define ICMP6_MAXTYPE
466                        *     as follows: n = ICMP6_MAXTYPE/32 + 1
467                         *     Actually is 203
468                        */
469 } ipfw_insn_icmp6;
470 
471 /*
472  * Here we have the structure representing an ipfw rule.
473  *
474  * It starts with a general area (with link fields and counters)
475  * followed by an array of one or more instructions, which the code
476  * accesses as an array of 32-bit values.
477  *
478  * Given a rule pointer  r:
479  *
480  *  r->cmd		is the start of the first instruction.
481  *  ACTION_PTR(r)	is the start of the first action (things to do
482  *			once a rule matched).
483  *
484  * When assembling instruction, remember the following:
485  *
486  *  + if a rule has a "keep-state" (or "limit") option, then the
487  *	first instruction (at r->cmd) MUST BE an O_PROBE_STATE
488  *  + if a rule has a "log" option, then the first action
489  *	(at ACTION_PTR(r)) MUST be O_LOG
490  *  + if a rule has an "altq" option, it comes after "log"
491  *  + if a rule has an O_TAG option, it comes after "log" and "altq"
492  *
493  * NOTE: we use a simple linked list of rules because we never need
494  * 	to delete a rule without scanning the list. We do not use
495  *	queue(3) macros for portability and readability.
496  */
497 
498 struct ip_fw {
499 	struct ip_fw	*x_next;	/* linked list of rules		*/
500 	struct ip_fw	*next_rule;	/* ptr to next [skipto] rule	*/
501 	/* 'next_rule' is used to pass up 'set_disable' status		*/
502 
503 	uint16_t	act_ofs;	/* offset of action in 32-bit units */
504 	uint16_t	cmd_len;	/* # of 32-bit words in cmd	*/
505 	uint16_t	rulenum;	/* rule number			*/
506 	uint8_t	set;		/* rule set (0..31)		*/
507 #define	RESVD_SET	31	/* set for default and persistent rules */
508 	uint8_t		_pad;		/* padding			*/
509 	uint32_t	id;		/* rule id */
510 
511 	/* These fields are present in all rules.			*/
512 	uint64_t	pcnt;		/* Packet counter		*/
513 	uint64_t	bcnt;		/* Byte counter			*/
514 	uint32_t	timestamp;	/* tv_sec of last match		*/
515 
516 	ipfw_insn	cmd[1];		/* storage for commands		*/
517 };
518 
519 #define ACTION_PTR(rule)				\
520 	(ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) )
521 
522 #define RULESIZE(rule)  (sizeof(struct ip_fw) + \
523 	((struct ip_fw *)(rule))->cmd_len * 4 - 4)
524 
525 #if 1 // should be moved to in.h
526 /*
527  * This structure is used as a flow mask and a flow id for various
528  * parts of the code.
529  * addr_type is used in userland and kernel to mark the address type.
530  * fib is used in the kernel to record the fib in use.
531  * _flags is used in the kernel to store tcp flags for dynamic rules.
532  */
533 struct ipfw_flow_id {
534 	uint32_t	dst_ip;
535 	uint32_t	src_ip;
536 	uint16_t	dst_port;
537 	uint16_t	src_port;
538 	uint8_t		fib;
539 	uint8_t		proto;
540 	uint8_t		_flags;	/* protocol-specific flags */
541 	uint8_t		addr_type; /* 4=ip4, 6=ip6, 1=ether ? */
542 	struct in6_addr dst_ip6;
543 	struct in6_addr src_ip6;
544 	uint32_t	flow_id6;
545 	uint32_t	extra; /* queue/pipe or frag_id */
546 };
547 #endif
548 
549 #define IS_IP6_FLOW_ID(id)	((id)->addr_type == 6)
550 
551 /*
552  * Dynamic ipfw rule.
553  */
554 typedef struct _ipfw_dyn_rule ipfw_dyn_rule;
555 
556 struct _ipfw_dyn_rule {
557 	ipfw_dyn_rule	*next;		/* linked list of rules.	*/
558 	struct ip_fw *rule;		/* pointer to rule		*/
559 	/* 'rule' is used to pass up the rule number (from the parent)	*/
560 
561 	ipfw_dyn_rule *parent;		/* pointer to parent rule	*/
562 	u_int64_t	pcnt;		/* packet match counter		*/
563 	u_int64_t	bcnt;		/* byte match counter		*/
564 	struct ipfw_flow_id id;		/* (masked) flow id		*/
565 	u_int32_t	expire;		/* expire time			*/
566 	u_int32_t	bucket;		/* which bucket in hash table	*/
567 	u_int32_t	state;		/* state of this rule (typically a
568 					 * combination of TCP flags)
569 					 */
570 	u_int32_t	ack_fwd;	/* most recent ACKs in forward	*/
571 	u_int32_t	ack_rev;	/* and reverse directions (used	*/
572 					/* to generate keepalives)	*/
573 	u_int16_t	dyn_type;	/* rule type			*/
574 	u_int16_t	count;		/* refcount			*/
575 };
576 
577 /*
578  * Definitions for IP option names.
579  */
580 #define	IP_FW_IPOPT_LSRR	0x01
581 #define	IP_FW_IPOPT_SSRR	0x02
582 #define	IP_FW_IPOPT_RR		0x04
583 #define	IP_FW_IPOPT_TS		0x08
584 
585 /*
586  * Definitions for TCP option names.
587  */
588 #define	IP_FW_TCPOPT_MSS	0x01
589 #define	IP_FW_TCPOPT_WINDOW	0x02
590 #define	IP_FW_TCPOPT_SACK	0x04
591 #define	IP_FW_TCPOPT_TS		0x08
592 #define	IP_FW_TCPOPT_CC		0x10
593 
594 #define	ICMP_REJECT_RST		0x100	/* fake ICMP code (send a TCP RST) */
595 #define	ICMP6_UNREACH_RST	0x100	/* fake ICMPv6 code (send a TCP RST) */
596 
597 /*
598  * These are used for lookup tables.
599  */
600 
601 #define	IPFW_TABLE_CIDR		1	/* Table for holding IPv4/IPv6 prefixes */
602 #define	IPFW_TABLE_INTERFACE	2	/* Table for holding interface names */
603 #define	IPFW_TABLE_MAXTYPE	2	/* Maximum valid number */
604 
605 typedef struct	_ipfw_table_entry {
606 	in_addr_t	addr;		/* network address		*/
607 	u_int32_t	value;		/* value			*/
608 	u_int16_t	tbl;		/* table number			*/
609 	u_int8_t	masklen;	/* mask length			*/
610 } ipfw_table_entry;
611 
612 typedef struct	_ipfw_table_xentry {
613 	uint16_t	len;		/* Total entry length		*/
614 	uint8_t		type;		/* entry type			*/
615 	uint8_t		masklen;	/* mask length			*/
616 	uint16_t	tbl;		/* table number			*/
617 	uint32_t	value;		/* value			*/
618 	union {
619 		/* Longest field needs to be aligned by 4-byte boundary	*/
620 		struct in6_addr	addr6;	/* IPv6 address 		*/
621 		char	iface[IF_NAMESIZE];	/* interface name	*/
622 	} k;
623 } ipfw_table_xentry;
624 
625 typedef struct	_ipfw_table {
626 	u_int32_t	size;		/* size of entries in bytes	*/
627 	u_int32_t	cnt;		/* # of entries			*/
628 	u_int16_t	tbl;		/* table number			*/
629 	ipfw_table_entry ent[0];	/* entries			*/
630 } ipfw_table;
631 
632 typedef struct	_ipfw_xtable {
633 	ip_fw3_opheader	opheader;	/* eXtended tables are controlled via IP_FW3 */
634 	uint32_t	size;		/* size of entries in bytes	*/
635 	uint32_t	cnt;		/* # of entries			*/
636 	uint16_t	tbl;		/* table number			*/
637 	uint8_t		type;		/* table type			*/
638 	ipfw_table_xentry xent[0];	/* entries			*/
639 } ipfw_xtable;
640 
641 #endif /* _IPFW2_H */
642