xref: /freebsd/sys/netinet/ip_fw.h (revision 721351876cd4d3a8a700f62d2061331fa951a488)
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_SETFIB,		/* arg1=FIB number */
165 	O_FIB,			/* arg1=FIB desired fib number */
166 
167 	O_LAST_OPCODE		/* not an opcode!		*/
168 };
169 
170 /*
171  * The extension header are filtered only for presence using a bit
172  * vector with a flag for each header.
173  */
174 #define EXT_FRAGMENT	0x1
175 #define EXT_HOPOPTS	0x2
176 #define EXT_ROUTING	0x4
177 #define EXT_AH		0x8
178 #define EXT_ESP		0x10
179 #define EXT_DSTOPTS	0x20
180 #define EXT_RTHDR0		0x40
181 #define EXT_RTHDR2		0x80
182 
183 /*
184  * Template for instructions.
185  *
186  * ipfw_insn is used for all instructions which require no operands,
187  * a single 16-bit value (arg1), or a couple of 8-bit values.
188  *
189  * For other instructions which require different/larger arguments
190  * we have derived structures, ipfw_insn_*.
191  *
192  * The size of the instruction (in 32-bit words) is in the low
193  * 6 bits of "len". The 2 remaining bits are used to implement
194  * NOT and OR on individual instructions. Given a type, you can
195  * compute the length to be put in "len" using F_INSN_SIZE(t)
196  *
197  * F_NOT	negates the match result of the instruction.
198  *
199  * F_OR		is used to build or blocks. By default, instructions
200  *		are evaluated as part of a logical AND. An "or" block
201  *		{ X or Y or Z } contains F_OR set in all but the last
202  *		instruction of the block. A match will cause the code
203  *		to skip past the last instruction of the block.
204  *
205  * NOTA BENE: in a couple of places we assume that
206  *	sizeof(ipfw_insn) == sizeof(u_int32_t)
207  * this needs to be fixed.
208  *
209  */
210 typedef struct	_ipfw_insn {	/* template for instructions */
211 	enum ipfw_opcodes	opcode:8;
212 	u_int8_t	len;	/* numer of 32-byte words */
213 #define	F_NOT		0x80
214 #define	F_OR		0x40
215 #define	F_LEN_MASK	0x3f
216 #define	F_LEN(cmd)	((cmd)->len & F_LEN_MASK)
217 
218 	u_int16_t	arg1;
219 } ipfw_insn;
220 
221 /*
222  * The F_INSN_SIZE(type) computes the size, in 4-byte words, of
223  * a given type.
224  */
225 #define	F_INSN_SIZE(t)	((sizeof (t))/sizeof(u_int32_t))
226 
227 #define MTAG_IPFW	1148380143	/* IPFW-tagged cookie */
228 
229 /*
230  * This is used to store an array of 16-bit entries (ports etc.)
231  */
232 typedef struct	_ipfw_insn_u16 {
233 	ipfw_insn o;
234 	u_int16_t ports[2];	/* there may be more */
235 } ipfw_insn_u16;
236 
237 /*
238  * This is used to store an array of 32-bit entries
239  * (uid, single IPv4 addresses etc.)
240  */
241 typedef struct	_ipfw_insn_u32 {
242 	ipfw_insn o;
243 	u_int32_t d[1];	/* one or more */
244 } ipfw_insn_u32;
245 
246 /*
247  * This is used to store IP addr-mask pairs.
248  */
249 typedef struct	_ipfw_insn_ip {
250 	ipfw_insn o;
251 	struct in_addr	addr;
252 	struct in_addr	mask;
253 } ipfw_insn_ip;
254 
255 /*
256  * This is used to forward to a given address (ip).
257  */
258 typedef struct  _ipfw_insn_sa {
259 	ipfw_insn o;
260 	struct sockaddr_in sa;
261 } ipfw_insn_sa;
262 
263 /*
264  * This is used for MAC addr-mask pairs.
265  */
266 typedef struct	_ipfw_insn_mac {
267 	ipfw_insn o;
268 	u_char addr[12];	/* dst[6] + src[6] */
269 	u_char mask[12];	/* dst[6] + src[6] */
270 } ipfw_insn_mac;
271 
272 /*
273  * This is used for interface match rules (recv xx, xmit xx).
274  */
275 typedef struct	_ipfw_insn_if {
276 	ipfw_insn o;
277 	union {
278 		struct in_addr ip;
279 		int glob;
280 	} p;
281 	char name[IFNAMSIZ];
282 } ipfw_insn_if;
283 
284 /*
285  * This is used for storing an altq queue id number.
286  */
287 typedef struct _ipfw_insn_altq {
288 	ipfw_insn	o;
289 	u_int32_t	qid;
290 } ipfw_insn_altq;
291 
292 /*
293  * This is used for limit rules.
294  */
295 typedef struct	_ipfw_insn_limit {
296 	ipfw_insn o;
297 	u_int8_t _pad;
298 	u_int8_t limit_mask;	/* combination of DYN_* below	*/
299 #define	DYN_SRC_ADDR	0x1
300 #define	DYN_SRC_PORT	0x2
301 #define	DYN_DST_ADDR	0x4
302 #define	DYN_DST_PORT	0x8
303 
304 	u_int16_t conn_limit;
305 } ipfw_insn_limit;
306 
307 /*
308  * This is used for log instructions.
309  */
310 typedef struct  _ipfw_insn_log {
311         ipfw_insn o;
312 	u_int32_t max_log;	/* how many do we log -- 0 = all */
313 	u_int32_t log_left;	/* how many left to log 	*/
314 } ipfw_insn_log;
315 
316 /*
317  * Data structures required by both ipfw(8) and ipfw(4) but not part of the
318  * management API are protected by IPFW_INTERNAL.
319  */
320 #ifdef IPFW_INTERNAL
321 /* Server pool support (LSNAT). */
322 struct cfg_spool {
323 	LIST_ENTRY(cfg_spool)   _next;          /* chain of spool instances */
324 	struct in_addr          addr;
325 	u_short                 port;
326 };
327 #endif
328 
329 /* Redirect modes id. */
330 #define REDIR_ADDR      0x01
331 #define REDIR_PORT      0x02
332 #define REDIR_PROTO     0x04
333 
334 #ifdef IPFW_INTERNAL
335 /* Nat redirect configuration. */
336 struct cfg_redir {
337 	LIST_ENTRY(cfg_redir)   _next;          /* chain of redir instances */
338 	u_int16_t               mode;           /* type of redirect mode */
339 	struct in_addr	        laddr;          /* local ip address */
340 	struct in_addr	        paddr;          /* public ip address */
341 	struct in_addr	        raddr;          /* remote ip address */
342 	u_short                 lport;          /* local port */
343 	u_short                 pport;          /* public port */
344 	u_short                 rport;          /* remote port  */
345 	u_short                 pport_cnt;      /* number of public ports */
346 	u_short                 rport_cnt;      /* number of remote ports */
347 	int                     proto;          /* protocol: tcp/udp */
348 	struct alias_link       **alink;
349 	/* num of entry in spool chain */
350 	u_int16_t               spool_cnt;
351 	/* chain of spool instances */
352 	LIST_HEAD(spool_chain, cfg_spool) spool_chain;
353 };
354 #endif
355 
356 #define NAT_BUF_LEN     1024
357 
358 #ifdef IPFW_INTERNAL
359 /* Nat configuration data struct. */
360 struct cfg_nat {
361 	/* chain of nat instances */
362 	LIST_ENTRY(cfg_nat)     _next;
363 	int                     id;                     /* nat id */
364 	struct in_addr          ip;                     /* nat ip address */
365 	char                    if_name[IF_NAMESIZE];   /* interface name */
366 	int                     mode;                   /* aliasing mode */
367 	struct libalias	        *lib;                   /* libalias instance */
368 	/* number of entry in spool chain */
369 	int                     redir_cnt;
370 	/* chain of redir instances */
371 	LIST_HEAD(redir_chain, cfg_redir) redir_chain;
372 };
373 #endif
374 
375 #define SOF_NAT         sizeof(struct cfg_nat)
376 #define SOF_REDIR       sizeof(struct cfg_redir)
377 #define SOF_SPOOL       sizeof(struct cfg_spool)
378 
379 /* Nat command. */
380 typedef struct	_ipfw_insn_nat {
381  	ipfw_insn	o;
382  	struct cfg_nat *nat;
383 } ipfw_insn_nat;
384 
385 /* Apply ipv6 mask on ipv6 addr */
386 #define APPLY_MASK(addr,mask)                          \
387     (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \
388     (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \
389     (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \
390     (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3];
391 
392 /* Structure for ipv6 */
393 typedef struct _ipfw_insn_ip6 {
394        ipfw_insn o;
395        struct in6_addr addr6;
396        struct in6_addr mask6;
397 } ipfw_insn_ip6;
398 
399 /* Used to support icmp6 types */
400 typedef struct _ipfw_insn_icmp6 {
401        ipfw_insn o;
402        uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h
403                        *     define ICMP6_MAXTYPE
404                        *     as follows: n = ICMP6_MAXTYPE/32 + 1
405                         *     Actually is 203
406                        */
407 } ipfw_insn_icmp6;
408 
409 /*
410  * Here we have the structure representing an ipfw rule.
411  *
412  * It starts with a general area (with link fields and counters)
413  * followed by an array of one or more instructions, which the code
414  * accesses as an array of 32-bit values.
415  *
416  * Given a rule pointer  r:
417  *
418  *  r->cmd		is the start of the first instruction.
419  *  ACTION_PTR(r)	is the start of the first action (things to do
420  *			once a rule matched).
421  *
422  * When assembling instruction, remember the following:
423  *
424  *  + if a rule has a "keep-state" (or "limit") option, then the
425  *	first instruction (at r->cmd) MUST BE an O_PROBE_STATE
426  *  + if a rule has a "log" option, then the first action
427  *	(at ACTION_PTR(r)) MUST be O_LOG
428  *  + if a rule has an "altq" option, it comes after "log"
429  *  + if a rule has an O_TAG option, it comes after "log" and "altq"
430  *
431  * NOTE: we use a simple linked list of rules because we never need
432  * 	to delete a rule without scanning the list. We do not use
433  *	queue(3) macros for portability and readability.
434  */
435 
436 struct ip_fw {
437 	struct ip_fw	*next;		/* linked list of rules		*/
438 	struct ip_fw	*next_rule;	/* ptr to next [skipto] rule	*/
439 	/* 'next_rule' is used to pass up 'set_disable' status		*/
440 
441 	u_int16_t	act_ofs;	/* offset of action in 32-bit units */
442 	u_int16_t	cmd_len;	/* # of 32-bit words in cmd	*/
443 	u_int16_t	rulenum;	/* rule number			*/
444 	u_int8_t	set;		/* rule set (0..31)		*/
445 #define	RESVD_SET	31	/* set for default and persistent rules */
446 	u_int8_t	_pad;		/* padding			*/
447 
448 	/* These fields are present in all rules.			*/
449 	u_int64_t	pcnt;		/* Packet counter		*/
450 	u_int64_t	bcnt;		/* Byte counter			*/
451 	u_int32_t	timestamp;	/* tv_sec of last match		*/
452 
453 	ipfw_insn	cmd[1];		/* storage for commands		*/
454 };
455 
456 #define ACTION_PTR(rule)				\
457 	(ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) )
458 
459 #define RULESIZE(rule)  (sizeof(struct ip_fw) + \
460 	((struct ip_fw *)(rule))->cmd_len * 4 - 4)
461 
462 /*
463  * This structure is used as a flow mask and a flow id for various
464  * parts of the code.
465  */
466 struct ipfw_flow_id {
467 	u_int32_t	dst_ip;
468 	u_int32_t	src_ip;
469 	u_int16_t	dst_port;
470 	u_int16_t	src_port;
471 	u_int8_t	fib;
472 	u_int8_t	proto;
473 	u_int8_t	flags;	/* protocol-specific flags */
474 	uint8_t		addr_type; /* 4 = ipv4, 6 = ipv6, 1=ether ? */
475 	struct in6_addr dst_ip6;	/* could also store MAC addr! */
476 	struct in6_addr src_ip6;
477 	u_int32_t	flow_id6;
478 	u_int32_t	frag_id6;
479 };
480 
481 #define IS_IP6_FLOW_ID(id)	((id)->addr_type == 6)
482 
483 /*
484  * Dynamic ipfw rule.
485  */
486 typedef struct _ipfw_dyn_rule ipfw_dyn_rule;
487 
488 struct _ipfw_dyn_rule {
489 	ipfw_dyn_rule	*next;		/* linked list of rules.	*/
490 	struct ip_fw *rule;		/* pointer to rule		*/
491 	/* 'rule' is used to pass up the rule number (from the parent)	*/
492 
493 	ipfw_dyn_rule *parent;		/* pointer to parent rule	*/
494 	u_int64_t	pcnt;		/* packet match counter		*/
495 	u_int64_t	bcnt;		/* byte match counter		*/
496 	struct ipfw_flow_id id;		/* (masked) flow id		*/
497 	u_int32_t	expire;		/* expire time			*/
498 	u_int32_t	bucket;		/* which bucket in hash table	*/
499 	u_int32_t	state;		/* state of this rule (typically a
500 					 * combination of TCP flags)
501 					 */
502 	u_int32_t	ack_fwd;	/* most recent ACKs in forward	*/
503 	u_int32_t	ack_rev;	/* and reverse directions (used	*/
504 					/* to generate keepalives)	*/
505 	u_int16_t	dyn_type;	/* rule type			*/
506 	u_int16_t	count;		/* refcount			*/
507 };
508 
509 /*
510  * Definitions for IP option names.
511  */
512 #define	IP_FW_IPOPT_LSRR	0x01
513 #define	IP_FW_IPOPT_SSRR	0x02
514 #define	IP_FW_IPOPT_RR		0x04
515 #define	IP_FW_IPOPT_TS		0x08
516 
517 /*
518  * Definitions for TCP option names.
519  */
520 #define	IP_FW_TCPOPT_MSS	0x01
521 #define	IP_FW_TCPOPT_WINDOW	0x02
522 #define	IP_FW_TCPOPT_SACK	0x04
523 #define	IP_FW_TCPOPT_TS		0x08
524 #define	IP_FW_TCPOPT_CC		0x10
525 
526 #define	ICMP_REJECT_RST		0x100	/* fake ICMP code (send a TCP RST) */
527 #define	ICMP6_UNREACH_RST	0x100	/* fake ICMPv6 code (send a TCP RST) */
528 
529 /*
530  * These are used for lookup tables.
531  */
532 typedef struct	_ipfw_table_entry {
533 	in_addr_t	addr;		/* network address		*/
534 	u_int32_t	value;		/* value			*/
535 	u_int16_t	tbl;		/* table number			*/
536 	u_int8_t	masklen;	/* mask length			*/
537 } ipfw_table_entry;
538 
539 typedef struct	_ipfw_table {
540 	u_int32_t	size;		/* size of entries in bytes	*/
541 	u_int32_t	cnt;		/* # of entries			*/
542 	u_int16_t	tbl;		/* table number			*/
543 	ipfw_table_entry ent[0];	/* entries			*/
544 } ipfw_table;
545 
546 #define IP_FW_TABLEARG	65535
547 
548 /*
549  * Main firewall chains definitions and global var's definitions.
550  */
551 #ifdef _KERNEL
552 
553 /* Return values from ipfw_chk() */
554 enum {
555 	IP_FW_PASS = 0,
556 	IP_FW_DENY,
557 	IP_FW_DIVERT,
558 	IP_FW_TEE,
559 	IP_FW_DUMMYNET,
560 	IP_FW_NETGRAPH,
561 	IP_FW_NGTEE,
562 	IP_FW_NAT,
563 };
564 
565 /* flags for divert mtag */
566 #define	IP_FW_DIVERT_LOOPBACK_FLAG	0x00080000
567 #define	IP_FW_DIVERT_OUTPUT_FLAG	0x00100000
568 
569 /*
570  * Structure for collecting parameters to dummynet for ip6_output forwarding
571  */
572 struct _ip6dn_args {
573        struct ip6_pktopts *opt_or;
574        struct route_in6 ro_or;
575        int flags_or;
576        struct ip6_moptions *im6o_or;
577        struct ifnet *origifp_or;
578        struct ifnet *ifp_or;
579        struct sockaddr_in6 dst_or;
580        u_long mtu_or;
581        struct route_in6 ro_pmtu_or;
582 };
583 
584 /*
585  * Arguments for calling ipfw_chk() and dummynet_io(). We put them
586  * all into a structure because this way it is easier and more
587  * efficient to pass variables around and extend the interface.
588  */
589 struct ip_fw_args {
590 	struct mbuf	*m;		/* the mbuf chain		*/
591 	struct ifnet	*oif;		/* output interface		*/
592 	struct sockaddr_in *next_hop;	/* forward address		*/
593 	struct ip_fw	*rule;		/* matching rule		*/
594 	struct ether_header *eh;	/* for bridged packets		*/
595 
596 	struct ipfw_flow_id f_id;	/* grabbed from IP header	*/
597 	u_int32_t	cookie;		/* a cookie depending on rule action */
598 	struct inpcb	*inp;
599 
600 	struct _ip6dn_args	dummypar; /* dummynet->ip6_output */
601 	struct sockaddr_in hopstore;	/* store here if cannot use a pointer */
602 };
603 
604 /*
605  * Function definitions.
606  */
607 
608 /* Firewall hooks */
609 struct sockopt;
610 struct dn_flow_set;
611 
612 int ipfw_check_in(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp);
613 int ipfw_check_out(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp);
614 
615 int ipfw_chk(struct ip_fw_args *);
616 
617 int ipfw_init(void);
618 void ipfw_destroy(void);
619 
620 typedef int ip_fw_ctl_t(struct sockopt *);
621 extern ip_fw_ctl_t *ip_fw_ctl_ptr;
622 extern int fw_one_pass;
623 extern int fw_enable;
624 #ifdef INET6
625 extern int fw6_enable;
626 #endif
627 
628 /* For kernel ipfw_ether and ipfw_bridge. */
629 typedef	int ip_fw_chk_t(struct ip_fw_args *args);
630 extern	ip_fw_chk_t	*ip_fw_chk_ptr;
631 #define	IPFW_LOADED	(ip_fw_chk_ptr != NULL)
632 
633 #ifdef IPFW_INTERNAL
634 
635 #define	IPFW_TABLES_MAX		128
636 struct ip_fw_chain {
637 	struct ip_fw	*rules;		/* list of rules */
638 	struct ip_fw	*reap;		/* list of rules to reap */
639 	LIST_HEAD(, cfg_nat) nat;       /* list of nat entries */
640 	struct radix_node_head *tables[IPFW_TABLES_MAX];
641 	struct rwlock	rwmtx;
642 };
643 #define	IPFW_LOCK_INIT(_chain) \
644 	rw_init(&(_chain)->rwmtx, "IPFW static rules")
645 #define	IPFW_LOCK_DESTROY(_chain)	rw_destroy(&(_chain)->rwmtx)
646 #define	IPFW_WLOCK_ASSERT(_chain)	rw_assert(&(_chain)->rwmtx, RA_WLOCKED)
647 
648 #define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx)
649 #define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx)
650 #define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx)
651 #define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx)
652 
653 #define LOOKUP_NAT(l, i, p) do {					\
654 		LIST_FOREACH((p), &(l.nat), _next) {			\
655 			if ((p)->id == (i)) {				\
656 				break;					\
657 			} 						\
658 		}							\
659 	} while (0)
660 
661 typedef int ipfw_nat_t(struct ip_fw_args *, struct cfg_nat *, struct mbuf *);
662 typedef int ipfw_nat_cfg_t(struct sockopt *);
663 #endif
664 
665 #endif /* _KERNEL */
666 #endif /* _IPFW2_H */
667