xref: /freebsd/sys/netinet/ip_fw.h (revision 10f0bcab61ef441cb5af32fb706688d8cbd55dc0)
1 /*-
2  * Copyright (c) 2002 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 kernel representation of ipfw rules is made of a list of
33  * 'instructions' (for all practical purposes equivalent to BPF
34  * instructions), which specify which fields of the packet
35  * (or its metadata) should be analysed.
36  *
37  * Each instruction is stored in a structure which begins with
38  * "ipfw_insn", and can contain extra fields depending on the
39  * instruction type (listed below).
40  * Note that the code is written so that individual instructions
41  * have a size which is a multiple of 32 bits. This means that, if
42  * such structures contain pointers or other 64-bit entities,
43  * (there is just one instance now) they may end up unaligned on
44  * 64-bit architectures, so the must be handled with care.
45  *
46  * "enum ipfw_opcodes" are the opcodes supported. We can have up
47  * to 256 different opcodes. When adding new opcodes, they should
48  * be appended to the end of the opcode list before O_LAST_OPCODE,
49  * this will prevent the ABI from being broken, otherwise users
50  * will have to recompile ipfw(8) when they update the kernel.
51  */
52 
53 enum ipfw_opcodes {		/* arguments (4 byte each)	*/
54 	O_NOP,
55 
56 	O_IP_SRC,		/* u32 = IP			*/
57 	O_IP_SRC_MASK,		/* ip = IP/mask			*/
58 	O_IP_SRC_ME,		/* none				*/
59 	O_IP_SRC_SET,		/* u32=base, arg1=len, bitmap	*/
60 
61 	O_IP_DST,		/* u32 = IP			*/
62 	O_IP_DST_MASK,		/* ip = IP/mask			*/
63 	O_IP_DST_ME,		/* none				*/
64 	O_IP_DST_SET,		/* u32=base, arg1=len, bitmap	*/
65 
66 	O_IP_SRCPORT,		/* (n)port list:mask 4 byte ea	*/
67 	O_IP_DSTPORT,		/* (n)port list:mask 4 byte ea	*/
68 	O_PROTO,		/* arg1=protocol		*/
69 
70 	O_MACADDR2,		/* 2 mac addr:mask		*/
71 	O_MAC_TYPE,		/* same as srcport		*/
72 
73 	O_LAYER2,		/* none				*/
74 	O_IN,			/* none				*/
75 	O_FRAG,			/* none				*/
76 
77 	O_RECV,			/* none				*/
78 	O_XMIT,			/* none				*/
79 	O_VIA,			/* none				*/
80 
81 	O_IPOPT,		/* arg1 = 2*u8 bitmap		*/
82 	O_IPLEN,		/* arg1 = len			*/
83 	O_IPID,			/* arg1 = id			*/
84 
85 	O_IPTOS,		/* arg1 = id			*/
86 	O_IPPRECEDENCE,		/* arg1 = precedence << 5	*/
87 	O_IPTTL,		/* arg1 = TTL			*/
88 
89 	O_IPVER,		/* arg1 = version		*/
90 	O_UID,			/* u32 = id			*/
91 	O_GID,			/* u32 = id			*/
92 	O_ESTAB,		/* none (tcp established)	*/
93 	O_TCPFLAGS,		/* arg1 = 2*u8 bitmap		*/
94 	O_TCPWIN,		/* arg1 = desired win		*/
95 	O_TCPSEQ,		/* u32 = desired seq.		*/
96 	O_TCPACK,		/* u32 = desired seq.		*/
97 	O_ICMPTYPE,		/* u32 = icmp bitmap		*/
98 	O_TCPOPTS,		/* arg1 = 2*u8 bitmap		*/
99 
100 	O_VERREVPATH,		/* none				*/
101 	O_VERSRCREACH,		/* none				*/
102 
103 	O_PROBE_STATE,		/* none				*/
104 	O_KEEP_STATE,		/* none				*/
105 	O_LIMIT,		/* ipfw_insn_limit		*/
106 	O_LIMIT_PARENT,		/* dyn_type, not an opcode.	*/
107 
108 	/*
109 	 * These are really 'actions'.
110 	 */
111 
112 	O_LOG,			/* ipfw_insn_log		*/
113 	O_PROB,			/* u32 = match probability	*/
114 
115 	O_CHECK_STATE,		/* none				*/
116 	O_ACCEPT,		/* none				*/
117 	O_DENY,			/* none 			*/
118 	O_REJECT,		/* arg1=icmp arg (same as deny)	*/
119 	O_COUNT,		/* none				*/
120 	O_SKIPTO,		/* arg1=next rule number	*/
121 	O_PIPE,			/* arg1=pipe number		*/
122 	O_QUEUE,		/* arg1=queue number		*/
123 	O_DIVERT,		/* arg1=port number		*/
124 	O_TEE,			/* arg1=port number		*/
125 	O_FORWARD_IP,		/* fwd sockaddr			*/
126 	O_FORWARD_MAC,		/* fwd mac			*/
127 	O_NAT,                  /* nope                         */
128 
129 	/*
130 	 * More opcodes.
131 	 */
132 	O_IPSEC,		/* has ipsec history 		*/
133 	O_IP_SRC_LOOKUP,	/* arg1=table number, u32=value	*/
134 	O_IP_DST_LOOKUP,	/* arg1=table number, u32=value	*/
135 	O_ANTISPOOF,		/* none				*/
136 	O_JAIL,			/* u32 = id			*/
137 	O_ALTQ,			/* u32 = altq classif. qid	*/
138 	O_DIVERTED,		/* arg1=bitmap (1:loop, 2:out)	*/
139 	O_TCPDATALEN,		/* arg1 = tcp data len		*/
140 	O_IP6_SRC,		/* address without mask		*/
141 	O_IP6_SRC_ME,		/* my addresses			*/
142 	O_IP6_SRC_MASK,		/* address with the mask	*/
143 	O_IP6_DST,
144 	O_IP6_DST_ME,
145 	O_IP6_DST_MASK,
146 	O_FLOW6ID,		/* for flow id tag in the ipv6 pkt */
147 	O_ICMP6TYPE,		/* icmp6 packet type filtering	*/
148 	O_EXT_HDR,		/* filtering for ipv6 extension header */
149 	O_IP6,
150 
151 	/*
152 	 * actions for ng_ipfw
153 	 */
154 	O_NETGRAPH,		/* send to ng_ipfw		*/
155 	O_NGTEE,		/* copy to ng_ipfw		*/
156 
157 	O_IP4,
158 
159 	O_UNREACH6,		/* arg1=icmpv6 code arg (deny)  */
160 
161 	O_TAG,   		/* arg1=tag number */
162 	O_TAGGED,		/* arg1=tag number */
163 
164 	O_LAST_OPCODE		/* not an opcode!		*/
165 };
166 
167 /*
168  * The extension header are filtered only for presence using a bit
169  * vector with a flag for each header.
170  */
171 #define EXT_FRAGMENT	0x1
172 #define EXT_HOPOPTS	0x2
173 #define EXT_ROUTING	0x4
174 #define EXT_AH		0x8
175 #define EXT_ESP		0x10
176 #define EXT_DSTOPTS	0x20
177 #define EXT_RTHDR0		0x40
178 #define EXT_RTHDR2		0x80
179 
180 /*
181  * Template for instructions.
182  *
183  * ipfw_insn is used for all instructions which require no operands,
184  * a single 16-bit value (arg1), or a couple of 8-bit values.
185  *
186  * For other instructions which require different/larger arguments
187  * we have derived structures, ipfw_insn_*.
188  *
189  * The size of the instruction (in 32-bit words) is in the low
190  * 6 bits of "len". The 2 remaining bits are used to implement
191  * NOT and OR on individual instructions. Given a type, you can
192  * compute the length to be put in "len" using F_INSN_SIZE(t)
193  *
194  * F_NOT	negates the match result of the instruction.
195  *
196  * F_OR		is used to build or blocks. By default, instructions
197  *		are evaluated as part of a logical AND. An "or" block
198  *		{ X or Y or Z } contains F_OR set in all but the last
199  *		instruction of the block. A match will cause the code
200  *		to skip past the last instruction of the block.
201  *
202  * NOTA BENE: in a couple of places we assume that
203  *	sizeof(ipfw_insn) == sizeof(u_int32_t)
204  * this needs to be fixed.
205  *
206  */
207 typedef struct	_ipfw_insn {	/* template for instructions */
208 	enum ipfw_opcodes	opcode:8;
209 	u_int8_t	len;	/* numer of 32-byte words */
210 #define	F_NOT		0x80
211 #define	F_OR		0x40
212 #define	F_LEN_MASK	0x3f
213 #define	F_LEN(cmd)	((cmd)->len & F_LEN_MASK)
214 
215 	u_int16_t	arg1;
216 } ipfw_insn;
217 
218 /*
219  * The F_INSN_SIZE(type) computes the size, in 4-byte words, of
220  * a given type.
221  */
222 #define	F_INSN_SIZE(t)	((sizeof (t))/sizeof(u_int32_t))
223 
224 #define MTAG_IPFW	1148380143	/* IPFW-tagged cookie */
225 
226 /*
227  * This is used to store an array of 16-bit entries (ports etc.)
228  */
229 typedef struct	_ipfw_insn_u16 {
230 	ipfw_insn o;
231 	u_int16_t ports[2];	/* there may be more */
232 } ipfw_insn_u16;
233 
234 /*
235  * This is used to store an array of 32-bit entries
236  * (uid, single IPv4 addresses etc.)
237  */
238 typedef struct	_ipfw_insn_u32 {
239 	ipfw_insn o;
240 	u_int32_t d[1];	/* one or more */
241 } ipfw_insn_u32;
242 
243 /*
244  * This is used to store IP addr-mask pairs.
245  */
246 typedef struct	_ipfw_insn_ip {
247 	ipfw_insn o;
248 	struct in_addr	addr;
249 	struct in_addr	mask;
250 } ipfw_insn_ip;
251 
252 /*
253  * This is used to forward to a given address (ip).
254  */
255 typedef struct  _ipfw_insn_sa {
256 	ipfw_insn o;
257 	struct sockaddr_in sa;
258 } ipfw_insn_sa;
259 
260 /*
261  * This is used for MAC addr-mask pairs.
262  */
263 typedef struct	_ipfw_insn_mac {
264 	ipfw_insn o;
265 	u_char addr[12];	/* dst[6] + src[6] */
266 	u_char mask[12];	/* dst[6] + src[6] */
267 } ipfw_insn_mac;
268 
269 /*
270  * This is used for interface match rules (recv xx, xmit xx).
271  */
272 typedef struct	_ipfw_insn_if {
273 	ipfw_insn o;
274 	union {
275 		struct in_addr ip;
276 		int glob;
277 	} p;
278 	char name[IFNAMSIZ];
279 } ipfw_insn_if;
280 
281 /*
282  * This is used for storing an altq queue id number.
283  */
284 typedef struct _ipfw_insn_altq {
285 	ipfw_insn	o;
286 	u_int32_t	qid;
287 } ipfw_insn_altq;
288 
289 /*
290  * This is used for limit rules.
291  */
292 typedef struct	_ipfw_insn_limit {
293 	ipfw_insn o;
294 	u_int8_t _pad;
295 	u_int8_t limit_mask;	/* combination of DYN_* below	*/
296 #define	DYN_SRC_ADDR	0x1
297 #define	DYN_SRC_PORT	0x2
298 #define	DYN_DST_ADDR	0x4
299 #define	DYN_DST_PORT	0x8
300 
301 	u_int16_t conn_limit;
302 } ipfw_insn_limit;
303 
304 /*
305  * This is used for log instructions.
306  */
307 typedef struct  _ipfw_insn_log {
308         ipfw_insn o;
309 	u_int32_t max_log;	/* how many do we log -- 0 = all */
310 	u_int32_t log_left;	/* how many left to log 	*/
311 } ipfw_insn_log;
312 
313 /*
314  * Data structures required by both ipfw(8) and ipfw(4) but not part of the
315  * management API are protcted by IPFW_INTERNAL.
316  */
317 #ifdef IPFW_INTERNAL
318 /* Server pool support (LSNAT). */
319 struct cfg_spool {
320 	LIST_ENTRY(cfg_spool)   _next;          /* chain of spool instances */
321 	struct in_addr          addr;
322 	u_short                 port;
323 };
324 #endif
325 
326 /* Redirect modes id. */
327 #define REDIR_ADDR      0x01
328 #define REDIR_PORT      0x02
329 #define REDIR_PROTO     0x04
330 
331 #ifdef IPFW_INTERNAL
332 /* Nat redirect configuration. */
333 struct cfg_redir {
334 	LIST_ENTRY(cfg_redir)   _next;          /* chain of redir instances */
335 	u_int16_t               mode;           /* type of redirect mode */
336 	struct in_addr	        laddr;          /* local ip address */
337 	struct in_addr	        paddr;          /* public ip address */
338 	struct in_addr	        raddr;          /* remote ip address */
339 	u_short                 lport;          /* local port */
340 	u_short                 pport;          /* public port */
341 	u_short                 rport;          /* remote port  */
342 	u_short                 pport_cnt;      /* number of public ports */
343 	u_short                 rport_cnt;      /* number of remote ports */
344 	int                     proto;          /* protocol: tcp/udp */
345 	struct alias_link       **alink;
346 	/* num of entry in spool chain */
347 	u_int16_t               spool_cnt;
348 	/* chain of spool instances */
349 	LIST_HEAD(spool_chain, cfg_spool) spool_chain;
350 };
351 #endif
352 
353 #define NAT_BUF_LEN     1024
354 
355 #ifdef IPFW_INTERNAL
356 /* Nat configuration data struct. */
357 struct cfg_nat {
358 	/* chain of nat instances */
359 	LIST_ENTRY(cfg_nat)     _next;
360 	int                     id;                     /* nat id */
361 	struct in_addr          ip;                     /* nat ip address */
362 	char                    if_name[IF_NAMESIZE];   /* interface name */
363 	int                     mode;                   /* aliasing mode */
364 	struct libalias	        *lib;                   /* libalias instance */
365 	/* number of entry in spool chain */
366 	int                     redir_cnt;
367 	/* chain of redir instances */
368 	LIST_HEAD(redir_chain, cfg_redir) redir_chain;
369 };
370 #endif
371 
372 #define SOF_NAT         sizeof(struct cfg_nat)
373 #define SOF_REDIR       sizeof(struct cfg_redir)
374 #define SOF_SPOOL       sizeof(struct cfg_spool)
375 
376 /* Nat command. */
377 typedef struct	_ipfw_insn_nat {
378  	ipfw_insn	o;
379  	struct cfg_nat *nat;
380 } ipfw_insn_nat;
381 
382 /* Apply ipv6 mask on ipv6 addr */
383 #define APPLY_MASK(addr,mask)                          \
384     (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \
385     (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \
386     (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \
387     (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3];
388 
389 /* Structure for ipv6 */
390 typedef struct _ipfw_insn_ip6 {
391        ipfw_insn o;
392        struct in6_addr addr6;
393        struct in6_addr mask6;
394 } ipfw_insn_ip6;
395 
396 /* Used to support icmp6 types */
397 typedef struct _ipfw_insn_icmp6 {
398        ipfw_insn o;
399        uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h
400                        *     define ICMP6_MAXTYPE
401                        *     as follows: n = ICMP6_MAXTYPE/32 + 1
402                         *     Actually is 203
403                        */
404 } ipfw_insn_icmp6;
405 
406 /*
407  * Here we have the structure representing an ipfw rule.
408  *
409  * It starts with a general area (with link fields and counters)
410  * followed by an array of one or more instructions, which the code
411  * accesses as an array of 32-bit values.
412  *
413  * Given a rule pointer  r:
414  *
415  *  r->cmd		is the start of the first instruction.
416  *  ACTION_PTR(r)	is the start of the first action (things to do
417  *			once a rule matched).
418  *
419  * When assembling instruction, remember the following:
420  *
421  *  + if a rule has a "keep-state" (or "limit") option, then the
422  *	first instruction (at r->cmd) MUST BE an O_PROBE_STATE
423  *  + if a rule has a "log" option, then the first action
424  *	(at ACTION_PTR(r)) MUST be O_LOG
425  *  + if a rule has an "altq" option, it comes after "log"
426  *  + if a rule has an O_TAG option, it comes after "log" and "altq"
427  *
428  * NOTE: we use a simple linked list of rules because we never need
429  * 	to delete a rule without scanning the list. We do not use
430  *	queue(3) macros for portability and readability.
431  */
432 
433 struct ip_fw {
434 	struct ip_fw	*next;		/* linked list of rules		*/
435 	struct ip_fw	*next_rule;	/* ptr to next [skipto] rule	*/
436 	/* 'next_rule' is used to pass up 'set_disable' status		*/
437 
438 	u_int16_t	act_ofs;	/* offset of action in 32-bit units */
439 	u_int16_t	cmd_len;	/* # of 32-bit words in cmd	*/
440 	u_int16_t	rulenum;	/* rule number			*/
441 	u_int8_t	set;		/* rule set (0..31)		*/
442 #define	RESVD_SET	31	/* set for default and persistent rules */
443 	u_int8_t	_pad;		/* padding			*/
444 
445 	/* These fields are present in all rules.			*/
446 	u_int64_t	pcnt;		/* Packet counter		*/
447 	u_int64_t	bcnt;		/* Byte counter			*/
448 	u_int32_t	timestamp;	/* tv_sec of last match		*/
449 
450 	ipfw_insn	cmd[1];		/* storage for commands		*/
451 };
452 
453 #define ACTION_PTR(rule)				\
454 	(ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) )
455 
456 #define RULESIZE(rule)  (sizeof(struct ip_fw) + \
457 	((struct ip_fw *)(rule))->cmd_len * 4 - 4)
458 
459 /*
460  * This structure is used as a flow mask and a flow id for various
461  * parts of the code.
462  */
463 struct ipfw_flow_id {
464 	u_int32_t	dst_ip;
465 	u_int32_t	src_ip;
466 	u_int16_t	dst_port;
467 	u_int16_t	src_port;
468 	u_int8_t	proto;
469 	u_int8_t	flags;	/* protocol-specific flags */
470 	uint8_t		addr_type; /* 4 = ipv4, 6 = ipv6, 1=ether ? */
471 	struct in6_addr dst_ip6;	/* could also store MAC addr! */
472 	struct in6_addr src_ip6;
473 	u_int32_t	flow_id6;
474 	u_int32_t	frag_id6;
475 };
476 
477 #define IS_IP6_FLOW_ID(id)	((id)->addr_type == 6)
478 
479 /*
480  * Dynamic ipfw rule.
481  */
482 typedef struct _ipfw_dyn_rule ipfw_dyn_rule;
483 
484 struct _ipfw_dyn_rule {
485 	ipfw_dyn_rule	*next;		/* linked list of rules.	*/
486 	struct ip_fw *rule;		/* pointer to rule		*/
487 	/* 'rule' is used to pass up the rule number (from the parent)	*/
488 
489 	ipfw_dyn_rule *parent;		/* pointer to parent rule	*/
490 	u_int64_t	pcnt;		/* packet match counter		*/
491 	u_int64_t	bcnt;		/* byte match counter		*/
492 	struct ipfw_flow_id id;		/* (masked) flow id		*/
493 	u_int32_t	expire;		/* expire time			*/
494 	u_int32_t	bucket;		/* which bucket in hash table	*/
495 	u_int32_t	state;		/* state of this rule (typically a
496 					 * combination of TCP flags)
497 					 */
498 	u_int32_t	ack_fwd;	/* most recent ACKs in forward	*/
499 	u_int32_t	ack_rev;	/* and reverse directions (used	*/
500 					/* to generate keepalives)	*/
501 	u_int16_t	dyn_type;	/* rule type			*/
502 	u_int16_t	count;		/* refcount			*/
503 };
504 
505 /*
506  * Definitions for IP option names.
507  */
508 #define	IP_FW_IPOPT_LSRR	0x01
509 #define	IP_FW_IPOPT_SSRR	0x02
510 #define	IP_FW_IPOPT_RR		0x04
511 #define	IP_FW_IPOPT_TS		0x08
512 
513 /*
514  * Definitions for TCP option names.
515  */
516 #define	IP_FW_TCPOPT_MSS	0x01
517 #define	IP_FW_TCPOPT_WINDOW	0x02
518 #define	IP_FW_TCPOPT_SACK	0x04
519 #define	IP_FW_TCPOPT_TS		0x08
520 #define	IP_FW_TCPOPT_CC		0x10
521 
522 #define	ICMP_REJECT_RST		0x100	/* fake ICMP code (send a TCP RST) */
523 #define	ICMP6_UNREACH_RST	0x100	/* fake ICMPv6 code (send a TCP RST) */
524 
525 /*
526  * These are used for lookup tables.
527  */
528 typedef struct	_ipfw_table_entry {
529 	in_addr_t	addr;		/* network address		*/
530 	u_int32_t	value;		/* value			*/
531 	u_int16_t	tbl;		/* table number			*/
532 	u_int8_t	masklen;	/* mask length			*/
533 } ipfw_table_entry;
534 
535 typedef struct	_ipfw_table {
536 	u_int32_t	size;		/* size of entries in bytes	*/
537 	u_int32_t	cnt;		/* # of entries			*/
538 	u_int16_t	tbl;		/* table number			*/
539 	ipfw_table_entry ent[0];	/* entries			*/
540 } ipfw_table;
541 
542 #define IP_FW_TABLEARG	65535
543 
544 /*
545  * Main firewall chains definitions and global var's definitions.
546  */
547 #ifdef _KERNEL
548 
549 /* Return values from ipfw_chk() */
550 enum {
551 	IP_FW_PASS = 0,
552 	IP_FW_DENY,
553 	IP_FW_DIVERT,
554 	IP_FW_TEE,
555 	IP_FW_DUMMYNET,
556 	IP_FW_NETGRAPH,
557 	IP_FW_NGTEE,
558 	IP_FW_NAT,
559 };
560 
561 /* flags for divert mtag */
562 #define	IP_FW_DIVERT_LOOPBACK_FLAG	0x00080000
563 #define	IP_FW_DIVERT_OUTPUT_FLAG	0x00100000
564 
565 /*
566  * Structure for collecting parameters to dummynet for ip6_output forwarding
567  */
568 struct _ip6dn_args {
569        struct ip6_pktopts *opt_or;
570        struct route_in6 ro_or;
571        int flags_or;
572        struct ip6_moptions *im6o_or;
573        struct ifnet *origifp_or;
574        struct ifnet *ifp_or;
575        struct sockaddr_in6 dst_or;
576        u_long mtu_or;
577        struct route_in6 ro_pmtu_or;
578 };
579 
580 /*
581  * Arguments for calling ipfw_chk() and dummynet_io(). We put them
582  * all into a structure because this way it is easier and more
583  * efficient to pass variables around and extend the interface.
584  */
585 struct ip_fw_args {
586 	struct mbuf	*m;		/* the mbuf chain		*/
587 	struct ifnet	*oif;		/* output interface		*/
588 	struct sockaddr_in *next_hop;	/* forward address		*/
589 	struct ip_fw	*rule;		/* matching rule		*/
590 	struct ether_header *eh;	/* for bridged packets		*/
591 
592 	struct ipfw_flow_id f_id;	/* grabbed from IP header	*/
593 	u_int32_t	cookie;		/* a cookie depending on rule action */
594 	struct inpcb	*inp;
595 
596 	struct _ip6dn_args	dummypar; /* dummynet->ip6_output */
597 	struct sockaddr_in hopstore;	/* store here if cannot use a pointer */
598 };
599 
600 /*
601  * Function definitions.
602  */
603 
604 /* Firewall hooks */
605 struct sockopt;
606 struct dn_flow_set;
607 
608 int ipfw_check_in(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp);
609 int ipfw_check_out(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp);
610 
611 int ipfw_chk(struct ip_fw_args *);
612 
613 int ipfw_init(void);
614 void ipfw_destroy(void);
615 
616 typedef int ip_fw_ctl_t(struct sockopt *);
617 extern ip_fw_ctl_t *ip_fw_ctl_ptr;
618 extern int fw_one_pass;
619 extern int fw_enable;
620 #ifdef INET6
621 extern int fw6_enable;
622 #endif
623 
624 /* For kernel ipfw_ether and ipfw_bridge. */
625 typedef	int ip_fw_chk_t(struct ip_fw_args *args);
626 extern	ip_fw_chk_t	*ip_fw_chk_ptr;
627 #define	IPFW_LOADED	(ip_fw_chk_ptr != NULL)
628 
629 #ifdef IPFW_INTERNAL
630 
631 #define	IPFW_TABLES_MAX		128
632 struct ip_fw_chain {
633 	struct ip_fw	*rules;		/* list of rules */
634 	struct ip_fw	*reap;		/* list of rules to reap */
635 	LIST_HEAD(, cfg_nat) nat;       /* list of nat entries */
636 	struct radix_node_head *tables[IPFW_TABLES_MAX];
637 	struct rwlock	rwmtx;
638 };
639 #define	IPFW_LOCK_INIT(_chain) \
640 	rw_init(&(_chain)->rwmtx, "IPFW static rules")
641 #define	IPFW_LOCK_DESTROY(_chain)	rw_destroy(&(_chain)->rwmtx)
642 #define	IPFW_WLOCK_ASSERT(_chain)	rw_assert(&(_chain)->rwmtx, RA_WLOCKED)
643 
644 #define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx)
645 #define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx)
646 #define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx)
647 #define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx)
648 
649 #define LOOKUP_NAT(l, i, p) do {					\
650 		LIST_FOREACH((p), &(l.nat), _next) {			\
651 			if ((p)->id == (i)) {				\
652 				break;					\
653 			} 						\
654 		}							\
655 	} while (0)
656 
657 typedef int ipfw_nat_t(struct ip_fw_args *, struct cfg_nat *, struct mbuf *);
658 typedef int ipfw_nat_cfg_t(struct sockopt *);
659 #endif
660 
661 #endif /* _KERNEL */
662 #endif /* _IPFW2_H */
663