xref: /freebsd/sys/netinet/ip_fw.h (revision 9517e866259191fcd39434a97ad849a9b59b9b9f)
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  * The number of ipfw tables.  The maximum allowed table number is the
41  * (IPFW_TABLES_MAX - 1).
42  */
43 #define	IPFW_TABLES_MAX		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  * The kernel representation of ipfw rules is made of a list of
61  * 'instructions' (for all practical purposes equivalent to BPF
62  * instructions), which specify which fields of the packet
63  * (or its metadata) should be analysed.
64  *
65  * Each instruction is stored in a structure which begins with
66  * "ipfw_insn", and can contain extra fields depending on the
67  * instruction type (listed below).
68  * Note that the code is written so that individual instructions
69  * have a size which is a multiple of 32 bits. This means that, if
70  * such structures contain pointers or other 64-bit entities,
71  * (there is just one instance now) they may end up unaligned on
72  * 64-bit architectures, so the must be handled with care.
73  *
74  * "enum ipfw_opcodes" are the opcodes supported. We can have up
75  * to 256 different opcodes. When adding new opcodes, they should
76  * be appended to the end of the opcode list before O_LAST_OPCODE,
77  * this will prevent the ABI from being broken, otherwise users
78  * will have to recompile ipfw(8) when they update the kernel.
79  */
80 
81 enum ipfw_opcodes {		/* arguments (4 byte each)	*/
82 	O_NOP,
83 
84 	O_IP_SRC,		/* u32 = IP			*/
85 	O_IP_SRC_MASK,		/* ip = IP/mask			*/
86 	O_IP_SRC_ME,		/* none				*/
87 	O_IP_SRC_SET,		/* u32=base, arg1=len, bitmap	*/
88 
89 	O_IP_DST,		/* u32 = IP			*/
90 	O_IP_DST_MASK,		/* ip = IP/mask			*/
91 	O_IP_DST_ME,		/* none				*/
92 	O_IP_DST_SET,		/* u32=base, arg1=len, bitmap	*/
93 
94 	O_IP_SRCPORT,		/* (n)port list:mask 4 byte ea	*/
95 	O_IP_DSTPORT,		/* (n)port list:mask 4 byte ea	*/
96 	O_PROTO,		/* arg1=protocol		*/
97 
98 	O_MACADDR2,		/* 2 mac addr:mask		*/
99 	O_MAC_TYPE,		/* same as srcport		*/
100 
101 	O_LAYER2,		/* none				*/
102 	O_IN,			/* none				*/
103 	O_FRAG,			/* none				*/
104 
105 	O_RECV,			/* none				*/
106 	O_XMIT,			/* none				*/
107 	O_VIA,			/* none				*/
108 
109 	O_IPOPT,		/* arg1 = 2*u8 bitmap		*/
110 	O_IPLEN,		/* arg1 = len			*/
111 	O_IPID,			/* arg1 = id			*/
112 
113 	O_IPTOS,		/* arg1 = id			*/
114 	O_IPPRECEDENCE,		/* arg1 = precedence << 5	*/
115 	O_IPTTL,		/* arg1 = TTL			*/
116 
117 	O_IPVER,		/* arg1 = version		*/
118 	O_UID,			/* u32 = id			*/
119 	O_GID,			/* u32 = id			*/
120 	O_ESTAB,		/* none (tcp established)	*/
121 	O_TCPFLAGS,		/* arg1 = 2*u8 bitmap		*/
122 	O_TCPWIN,		/* arg1 = desired win		*/
123 	O_TCPSEQ,		/* u32 = desired seq.		*/
124 	O_TCPACK,		/* u32 = desired seq.		*/
125 	O_ICMPTYPE,		/* u32 = icmp bitmap		*/
126 	O_TCPOPTS,		/* arg1 = 2*u8 bitmap		*/
127 
128 	O_VERREVPATH,		/* none				*/
129 	O_VERSRCREACH,		/* none				*/
130 
131 	O_PROBE_STATE,		/* none				*/
132 	O_KEEP_STATE,		/* none				*/
133 	O_LIMIT,		/* ipfw_insn_limit		*/
134 	O_LIMIT_PARENT,		/* dyn_type, not an opcode.	*/
135 
136 	/*
137 	 * These are really 'actions'.
138 	 */
139 
140 	O_LOG,			/* ipfw_insn_log		*/
141 	O_PROB,			/* u32 = match probability	*/
142 
143 	O_CHECK_STATE,		/* none				*/
144 	O_ACCEPT,		/* none				*/
145 	O_DENY,			/* none 			*/
146 	O_REJECT,		/* arg1=icmp arg (same as deny)	*/
147 	O_COUNT,		/* none				*/
148 	O_SKIPTO,		/* arg1=next rule number	*/
149 	O_PIPE,			/* arg1=pipe number		*/
150 	O_QUEUE,		/* arg1=queue number		*/
151 	O_DIVERT,		/* arg1=port number		*/
152 	O_TEE,			/* arg1=port number		*/
153 	O_FORWARD_IP,		/* fwd sockaddr			*/
154 	O_FORWARD_MAC,		/* fwd mac			*/
155 	O_NAT,                  /* nope                         */
156 	O_REASS,                /* none                         */
157 
158 	/*
159 	 * More opcodes.
160 	 */
161 	O_IPSEC,		/* has ipsec history 		*/
162 	O_IP_SRC_LOOKUP,	/* arg1=table number, u32=value	*/
163 	O_IP_DST_LOOKUP,	/* arg1=table number, u32=value	*/
164 	O_ANTISPOOF,		/* none				*/
165 	O_JAIL,			/* u32 = id			*/
166 	O_ALTQ,			/* u32 = altq classif. qid	*/
167 	O_DIVERTED,		/* arg1=bitmap (1:loop, 2:out)	*/
168 	O_TCPDATALEN,		/* arg1 = tcp data len		*/
169 	O_IP6_SRC,		/* address without mask		*/
170 	O_IP6_SRC_ME,		/* my addresses			*/
171 	O_IP6_SRC_MASK,		/* address with the mask	*/
172 	O_IP6_DST,
173 	O_IP6_DST_ME,
174 	O_IP6_DST_MASK,
175 	O_FLOW6ID,		/* for flow id tag in the ipv6 pkt */
176 	O_ICMP6TYPE,		/* icmp6 packet type filtering	*/
177 	O_EXT_HDR,		/* filtering for ipv6 extension header */
178 	O_IP6,
179 
180 	/*
181 	 * actions for ng_ipfw
182 	 */
183 	O_NETGRAPH,		/* send to ng_ipfw		*/
184 	O_NGTEE,		/* copy to ng_ipfw		*/
185 
186 	O_IP4,
187 
188 	O_UNREACH6,		/* arg1=icmpv6 code arg (deny)  */
189 
190 	O_TAG,   		/* arg1=tag number */
191 	O_TAGGED,		/* arg1=tag number */
192 
193 	O_SETFIB,		/* arg1=FIB number */
194 	O_FIB,			/* arg1=FIB desired fib number */
195 
196 	O_LAST_OPCODE		/* not an opcode!		*/
197 };
198 
199 /*
200  * The extension header are filtered only for presence using a bit
201  * vector with a flag for each header.
202  */
203 #define EXT_FRAGMENT	0x1
204 #define EXT_HOPOPTS	0x2
205 #define EXT_ROUTING	0x4
206 #define EXT_AH		0x8
207 #define EXT_ESP		0x10
208 #define EXT_DSTOPTS	0x20
209 #define EXT_RTHDR0		0x40
210 #define EXT_RTHDR2		0x80
211 
212 /*
213  * Template for instructions.
214  *
215  * ipfw_insn is used for all instructions which require no operands,
216  * a single 16-bit value (arg1), or a couple of 8-bit values.
217  *
218  * For other instructions which require different/larger arguments
219  * we have derived structures, ipfw_insn_*.
220  *
221  * The size of the instruction (in 32-bit words) is in the low
222  * 6 bits of "len". The 2 remaining bits are used to implement
223  * NOT and OR on individual instructions. Given a type, you can
224  * compute the length to be put in "len" using F_INSN_SIZE(t)
225  *
226  * F_NOT	negates the match result of the instruction.
227  *
228  * F_OR		is used to build or blocks. By default, instructions
229  *		are evaluated as part of a logical AND. An "or" block
230  *		{ X or Y or Z } contains F_OR set in all but the last
231  *		instruction of the block. A match will cause the code
232  *		to skip past the last instruction of the block.
233  *
234  * NOTA BENE: in a couple of places we assume that
235  *	sizeof(ipfw_insn) == sizeof(u_int32_t)
236  * this needs to be fixed.
237  *
238  */
239 typedef struct	_ipfw_insn {	/* template for instructions */
240 	enum ipfw_opcodes	opcode:8;
241 	u_int8_t	len;	/* number of 32-bit words */
242 #define	F_NOT		0x80
243 #define	F_OR		0x40
244 #define	F_LEN_MASK	0x3f
245 #define	F_LEN(cmd)	((cmd)->len & F_LEN_MASK)
246 
247 	u_int16_t	arg1;
248 } ipfw_insn;
249 
250 /*
251  * The F_INSN_SIZE(type) computes the size, in 4-byte words, of
252  * a given type.
253  */
254 #define	F_INSN_SIZE(t)	((sizeof (t))/sizeof(u_int32_t))
255 
256 /*
257  * This is used to store an array of 16-bit entries (ports etc.)
258  */
259 typedef struct	_ipfw_insn_u16 {
260 	ipfw_insn o;
261 	u_int16_t ports[2];	/* there may be more */
262 } ipfw_insn_u16;
263 
264 /*
265  * This is used to store an array of 32-bit entries
266  * (uid, single IPv4 addresses etc.)
267  */
268 typedef struct	_ipfw_insn_u32 {
269 	ipfw_insn o;
270 	u_int32_t d[1];	/* one or more */
271 } ipfw_insn_u32;
272 
273 /*
274  * This is used to store IP addr-mask pairs.
275  */
276 typedef struct	_ipfw_insn_ip {
277 	ipfw_insn o;
278 	struct in_addr	addr;
279 	struct in_addr	mask;
280 } ipfw_insn_ip;
281 
282 /*
283  * This is used to forward to a given address (ip).
284  */
285 typedef struct  _ipfw_insn_sa {
286 	ipfw_insn o;
287 	struct sockaddr_in sa;
288 } ipfw_insn_sa;
289 
290 /*
291  * This is used for MAC addr-mask pairs.
292  */
293 typedef struct	_ipfw_insn_mac {
294 	ipfw_insn o;
295 	u_char addr[12];	/* dst[6] + src[6] */
296 	u_char mask[12];	/* dst[6] + src[6] */
297 } ipfw_insn_mac;
298 
299 /*
300  * This is used for interface match rules (recv xx, xmit xx).
301  */
302 typedef struct	_ipfw_insn_if {
303 	ipfw_insn o;
304 	union {
305 		struct in_addr ip;
306 		int glob;
307 	} p;
308 	char name[IFNAMSIZ];
309 } ipfw_insn_if;
310 
311 /*
312  * This is used for storing an altq queue id number.
313  */
314 typedef struct _ipfw_insn_altq {
315 	ipfw_insn	o;
316 	u_int32_t	qid;
317 } ipfw_insn_altq;
318 
319 /*
320  * This is used for limit rules.
321  */
322 typedef struct	_ipfw_insn_limit {
323 	ipfw_insn o;
324 	u_int8_t _pad;
325 	u_int8_t limit_mask;	/* combination of DYN_* below	*/
326 #define	DYN_SRC_ADDR	0x1
327 #define	DYN_SRC_PORT	0x2
328 #define	DYN_DST_ADDR	0x4
329 #define	DYN_DST_PORT	0x8
330 
331 	u_int16_t conn_limit;
332 } ipfw_insn_limit;
333 
334 /*
335  * This is used for log instructions.
336  */
337 typedef struct  _ipfw_insn_log {
338         ipfw_insn o;
339 	u_int32_t max_log;	/* how many do we log -- 0 = all */
340 	u_int32_t log_left;	/* how many left to log 	*/
341 } ipfw_insn_log;
342 
343 /*
344  * Data structures required by both ipfw(8) and ipfw(4) but not part of the
345  * management API are protected by IPFW_INTERNAL.
346  */
347 #ifdef IPFW_INTERNAL
348 /* Server pool support (LSNAT). */
349 struct cfg_spool {
350 	LIST_ENTRY(cfg_spool)   _next;          /* chain of spool instances */
351 	struct in_addr          addr;
352 	u_short                 port;
353 };
354 #endif
355 
356 /* Redirect modes id. */
357 #define REDIR_ADDR      0x01
358 #define REDIR_PORT      0x02
359 #define REDIR_PROTO     0x04
360 
361 #ifdef IPFW_INTERNAL
362 /* Nat redirect configuration. */
363 struct cfg_redir {
364 	LIST_ENTRY(cfg_redir)   _next;          /* chain of redir instances */
365 	u_int16_t               mode;           /* type of redirect mode */
366 	struct in_addr	        laddr;          /* local ip address */
367 	struct in_addr	        paddr;          /* public ip address */
368 	struct in_addr	        raddr;          /* remote ip address */
369 	u_short                 lport;          /* local port */
370 	u_short                 pport;          /* public port */
371 	u_short                 rport;          /* remote port  */
372 	u_short                 pport_cnt;      /* number of public ports */
373 	u_short                 rport_cnt;      /* number of remote ports */
374 	int                     proto;          /* protocol: tcp/udp */
375 	struct alias_link       **alink;
376 	/* num of entry in spool chain */
377 	u_int16_t               spool_cnt;
378 	/* chain of spool instances */
379 	LIST_HEAD(spool_chain, cfg_spool) spool_chain;
380 };
381 #endif
382 
383 #define NAT_BUF_LEN     1024
384 
385 #ifdef IPFW_INTERNAL
386 /* Nat configuration data struct. */
387 struct cfg_nat {
388 	/* chain of nat instances */
389 	LIST_ENTRY(cfg_nat)     _next;
390 	int                     id;                     /* nat id */
391 	struct in_addr          ip;                     /* nat ip address */
392 	char                    if_name[IF_NAMESIZE];   /* interface name */
393 	int                     mode;                   /* aliasing mode */
394 	struct libalias	        *lib;                   /* libalias instance */
395 	/* number of entry in spool chain */
396 	int                     redir_cnt;
397 	/* chain of redir instances */
398 	LIST_HEAD(redir_chain, cfg_redir) redir_chain;
399 };
400 #endif
401 
402 #define SOF_NAT         sizeof(struct cfg_nat)
403 #define SOF_REDIR       sizeof(struct cfg_redir)
404 #define SOF_SPOOL       sizeof(struct cfg_spool)
405 
406 /* Nat command. */
407 typedef struct	_ipfw_insn_nat {
408  	ipfw_insn	o;
409  	struct cfg_nat *nat;
410 } ipfw_insn_nat;
411 
412 /* Apply ipv6 mask on ipv6 addr */
413 #define APPLY_MASK(addr,mask)                          \
414     (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \
415     (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \
416     (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \
417     (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3];
418 
419 /* Structure for ipv6 */
420 typedef struct _ipfw_insn_ip6 {
421        ipfw_insn o;
422        struct in6_addr addr6;
423        struct in6_addr mask6;
424 } ipfw_insn_ip6;
425 
426 /* Used to support icmp6 types */
427 typedef struct _ipfw_insn_icmp6 {
428        ipfw_insn o;
429        uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h
430                        *     define ICMP6_MAXTYPE
431                        *     as follows: n = ICMP6_MAXTYPE/32 + 1
432                         *     Actually is 203
433                        */
434 } ipfw_insn_icmp6;
435 
436 /*
437  * Here we have the structure representing an ipfw rule.
438  *
439  * It starts with a general area (with link fields and counters)
440  * followed by an array of one or more instructions, which the code
441  * accesses as an array of 32-bit values.
442  *
443  * Given a rule pointer  r:
444  *
445  *  r->cmd		is the start of the first instruction.
446  *  ACTION_PTR(r)	is the start of the first action (things to do
447  *			once a rule matched).
448  *
449  * When assembling instruction, remember the following:
450  *
451  *  + if a rule has a "keep-state" (or "limit") option, then the
452  *	first instruction (at r->cmd) MUST BE an O_PROBE_STATE
453  *  + if a rule has a "log" option, then the first action
454  *	(at ACTION_PTR(r)) MUST be O_LOG
455  *  + if a rule has an "altq" option, it comes after "log"
456  *  + if a rule has an O_TAG option, it comes after "log" and "altq"
457  *
458  * NOTE: we use a simple linked list of rules because we never need
459  * 	to delete a rule without scanning the list. We do not use
460  *	queue(3) macros for portability and readability.
461  */
462 
463 struct ip_fw {
464 	struct ip_fw	*next;		/* linked list of rules		*/
465 	struct ip_fw	*next_rule;	/* ptr to next [skipto] rule	*/
466 	/* 'next_rule' is used to pass up 'set_disable' status		*/
467 
468 	uint16_t	act_ofs;	/* offset of action in 32-bit units */
469 	uint16_t	cmd_len;	/* # of 32-bit words in cmd	*/
470 	uint16_t	rulenum;	/* rule number			*/
471 	uint8_t	set;		/* rule set (0..31)		*/
472 #define	RESVD_SET	31	/* set for default and persistent rules */
473 	uint8_t		_pad;		/* padding			*/
474 	uint32_t	id;		/* rule id */
475 
476 	/* These fields are present in all rules.			*/
477 	uint64_t	pcnt;		/* Packet counter		*/
478 	uint64_t	bcnt;		/* Byte counter			*/
479 	uint32_t	timestamp;	/* tv_sec of last match		*/
480 
481 	ipfw_insn	cmd[1];		/* storage for commands		*/
482 };
483 
484 #define ACTION_PTR(rule)				\
485 	(ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) )
486 
487 #define RULESIZE(rule)  (sizeof(struct ip_fw) + \
488 	((struct ip_fw *)(rule))->cmd_len * 4 - 4)
489 
490 /*
491  * This structure is used as a flow mask and a flow id for various
492  * parts of the code.
493  */
494 struct ipfw_flow_id {
495 	u_int32_t	dst_ip;
496 	u_int32_t	src_ip;
497 	u_int16_t	dst_port;
498 	u_int16_t	src_port;
499 	u_int8_t	fib;
500 	u_int8_t	proto;
501 	u_int8_t	flags;	/* protocol-specific flags */
502 	uint8_t		addr_type; /* 4 = ipv4, 6 = ipv6, 1=ether ? */
503 	struct in6_addr dst_ip6;	/* could also store MAC addr! */
504 	struct in6_addr src_ip6;
505 	u_int32_t	flow_id6;
506 	u_int32_t	frag_id6;
507 };
508 
509 #define IS_IP6_FLOW_ID(id)	((id)->addr_type == 6)
510 
511 /*
512  * Dynamic ipfw rule.
513  */
514 typedef struct _ipfw_dyn_rule ipfw_dyn_rule;
515 
516 struct _ipfw_dyn_rule {
517 	ipfw_dyn_rule	*next;		/* linked list of rules.	*/
518 	struct ip_fw *rule;		/* pointer to rule		*/
519 	/* 'rule' is used to pass up the rule number (from the parent)	*/
520 
521 	ipfw_dyn_rule *parent;		/* pointer to parent rule	*/
522 	u_int64_t	pcnt;		/* packet match counter		*/
523 	u_int64_t	bcnt;		/* byte match counter		*/
524 	struct ipfw_flow_id id;		/* (masked) flow id		*/
525 	u_int32_t	expire;		/* expire time			*/
526 	u_int32_t	bucket;		/* which bucket in hash table	*/
527 	u_int32_t	state;		/* state of this rule (typically a
528 					 * combination of TCP flags)
529 					 */
530 	u_int32_t	ack_fwd;	/* most recent ACKs in forward	*/
531 	u_int32_t	ack_rev;	/* and reverse directions (used	*/
532 					/* to generate keepalives)	*/
533 	u_int16_t	dyn_type;	/* rule type			*/
534 	u_int16_t	count;		/* refcount			*/
535 };
536 
537 /*
538  * Definitions for IP option names.
539  */
540 #define	IP_FW_IPOPT_LSRR	0x01
541 #define	IP_FW_IPOPT_SSRR	0x02
542 #define	IP_FW_IPOPT_RR		0x04
543 #define	IP_FW_IPOPT_TS		0x08
544 
545 /*
546  * Definitions for TCP option names.
547  */
548 #define	IP_FW_TCPOPT_MSS	0x01
549 #define	IP_FW_TCPOPT_WINDOW	0x02
550 #define	IP_FW_TCPOPT_SACK	0x04
551 #define	IP_FW_TCPOPT_TS		0x08
552 #define	IP_FW_TCPOPT_CC		0x10
553 
554 #define	ICMP_REJECT_RST		0x100	/* fake ICMP code (send a TCP RST) */
555 #define	ICMP6_UNREACH_RST	0x100	/* fake ICMPv6 code (send a TCP RST) */
556 
557 /*
558  * These are used for lookup tables.
559  */
560 typedef struct	_ipfw_table_entry {
561 	in_addr_t	addr;		/* network address		*/
562 	u_int32_t	value;		/* value			*/
563 	u_int16_t	tbl;		/* table number			*/
564 	u_int8_t	masklen;	/* mask length			*/
565 } ipfw_table_entry;
566 
567 typedef struct	_ipfw_table {
568 	u_int32_t	size;		/* size of entries in bytes	*/
569 	u_int32_t	cnt;		/* # of entries			*/
570 	u_int16_t	tbl;		/* table number			*/
571 	ipfw_table_entry ent[0];	/* entries			*/
572 } ipfw_table;
573 
574 /*
575  * Main firewall chains definitions and global var's definitions.
576  */
577 #ifdef _KERNEL
578 
579 #define MTAG_IPFW	1148380143	/* IPFW-tagged cookie */
580 
581 /* Return values from ipfw_chk() */
582 enum {
583 	IP_FW_PASS = 0,
584 	IP_FW_DENY,
585 	IP_FW_DIVERT,
586 	IP_FW_TEE,
587 	IP_FW_DUMMYNET,
588 	IP_FW_NETGRAPH,
589 	IP_FW_NGTEE,
590 	IP_FW_NAT,
591 	IP_FW_REASS,
592 };
593 
594 /* flags for divert mtag */
595 #define	IP_FW_DIVERT_LOOPBACK_FLAG	0x00080000
596 #define	IP_FW_DIVERT_OUTPUT_FLAG	0x00100000
597 
598 /*
599  * Structure for collecting parameters to dummynet for ip6_output forwarding
600  */
601 struct _ip6dn_args {
602        struct ip6_pktopts *opt_or;
603        struct route_in6 ro_or;
604        int flags_or;
605        struct ip6_moptions *im6o_or;
606        struct ifnet *origifp_or;
607        struct ifnet *ifp_or;
608        struct sockaddr_in6 dst_or;
609        u_long mtu_or;
610        struct route_in6 ro_pmtu_or;
611 };
612 
613 /*
614  * Arguments for calling ipfw_chk() and dummynet_io(). We put them
615  * all into a structure because this way it is easier and more
616  * efficient to pass variables around and extend the interface.
617  */
618 struct ip_fw_args {
619 	struct mbuf	*m;		/* the mbuf chain		*/
620 	struct ifnet	*oif;		/* output interface		*/
621 	struct sockaddr_in *next_hop;	/* forward address		*/
622 	struct ip_fw	*rule;		/* matching rule		*/
623 	uint32_t	rule_id;	/* matching rule id */
624 	uint32_t	chain_id;	/* ruleset id */
625 	struct ether_header *eh;	/* for bridged packets		*/
626 
627 	struct ipfw_flow_id f_id;	/* grabbed from IP header	*/
628 	uint32_t	cookie;		/* a cookie depending on rule action */
629 	struct inpcb	*inp;
630 
631 	struct _ip6dn_args	dummypar; /* dummynet->ip6_output */
632 	struct sockaddr_in hopstore;	/* store here if cannot use a pointer */
633 };
634 
635 /*
636  * Function definitions.
637  */
638 
639 /* Firewall hooks */
640 struct sockopt;
641 struct dn_flow_set;
642 
643 int ipfw_check_in(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp);
644 int ipfw_check_out(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp);
645 
646 int ipfw_chk(struct ip_fw_args *);
647 
648 int ipfw_init(void);
649 void ipfw_destroy(void);
650 #ifdef NOTYET
651 void ipfw_nat_destroy(void);
652 #endif
653 
654 VNET_DECLARE(int, fw_one_pass);
655 VNET_DECLARE(int, fw_enable);
656 #define	V_fw_one_pass		VNET(fw_one_pass)
657 #define	V_fw_enable		VNET(fw_enable)
658 
659 #ifdef INET6
660 VNET_DECLARE(int, fw6_enable);
661 #define	V_fw6_enable		VNET(fw6_enable)
662 #endif
663 
664 struct ip_fw_chain {
665 	struct ip_fw	*rules;		/* list of rules */
666 	struct ip_fw	*reap;		/* list of rules to reap */
667 	LIST_HEAD(, cfg_nat) nat;       /* list of nat entries */
668 	struct radix_node_head *tables[IPFW_TABLES_MAX];
669 	struct rwlock	rwmtx;
670 	uint32_t	id;		/* ruleset id */
671 };
672 
673 #ifdef IPFW_INTERNAL
674 
675 #define	IPFW_LOCK_INIT(_chain) \
676 	rw_init(&(_chain)->rwmtx, "IPFW static rules")
677 #define	IPFW_LOCK_DESTROY(_chain)	rw_destroy(&(_chain)->rwmtx)
678 #define	IPFW_WLOCK_ASSERT(_chain)	rw_assert(&(_chain)->rwmtx, RA_WLOCKED)
679 
680 #define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx)
681 #define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx)
682 #define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx)
683 #define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx)
684 
685 #define LOOKUP_NAT(l, i, p) do {					\
686 		LIST_FOREACH((p), &(l.nat), _next) {			\
687 			if ((p)->id == (i)) {				\
688 				break;					\
689 			} 						\
690 		}							\
691 	} while (0)
692 
693 typedef int ipfw_nat_t(struct ip_fw_args *, struct cfg_nat *, struct mbuf *);
694 typedef int ipfw_nat_cfg_t(struct sockopt *);
695 #endif
696 
697 VNET_DECLARE(struct ip_fw_chain, layer3_chain);
698 #define	V_layer3_chain		VNET(layer3_chain)
699 
700 #endif /* _KERNEL */
701 #endif /* _IPFW2_H */
702