1 /*	$FreeBSD: stable/9/sys/contrib/ipfilter/netinet/ip_nat.h 180778 2008-07-24 12:35:05Z darrenr $	*/
2 
3 /*
4  * Copyright (C) 1995-2001, 2003 by Darren Reed.
5  *
6  * See the IPFILTER.LICENCE file for details on licencing.
7  *
8  * @(#)ip_nat.h	1.5 2/4/96
9  * $FreeBSD: stable/9/sys/contrib/ipfilter/netinet/ip_nat.h 180778 2008-07-24 12:35:05Z darrenr $
10  * Id: ip_nat.h,v 2.90.2.20 2007/09/25 08:27:32 darrenr Exp $
11  */
12 
13 #ifndef	__IP_NAT_H__
14 #define	__IP_NAT_H__
15 
16 #ifndef SOLARIS
17 #define	SOLARIS	(defined(sun) && (defined(__svr4__) || defined(__SVR4)))
18 #endif
19 
20 #if defined(__STDC__) || defined(__GNUC__) || defined(_AIX51)
21 #define	SIOCADNAT	_IOW('r', 60, struct ipfobj)
22 #define	SIOCRMNAT	_IOW('r', 61, struct ipfobj)
23 #define	SIOCGNATS	_IOWR('r', 62, struct ipfobj)
24 #define	SIOCGNATL	_IOWR('r', 63, struct ipfobj)
25 #else
26 #define	SIOCADNAT	_IOW(r, 60, struct ipfobj)
27 #define	SIOCRMNAT	_IOW(r, 61, struct ipfobj)
28 #define	SIOCGNATS	_IOWR(r, 62, struct ipfobj)
29 #define	SIOCGNATL	_IOWR(r, 63, struct ipfobj)
30 #endif
31 
32 #undef	LARGE_NAT	/* define	this if you're setting up a system to NAT
33 			 * LARGE numbers of networks/hosts - i.e. in the
34 			 * hundreds or thousands.  In such a case, you should
35 			 * also change the RDR_SIZE and NAT_SIZE below to more
36 			 * appropriate sizes.  The figures below were used for
37 			 * a setup with 1000-2000 networks to NAT.
38 			 */
39 #ifndef NAT_SIZE
40 # ifdef LARGE_NAT
41 #  define	NAT_SIZE	2047
42 # else
43 #  define	NAT_SIZE	127
44 # endif
45 #endif
46 #ifndef RDR_SIZE
47 # ifdef LARGE_NAT
48 #  define	RDR_SIZE	2047
49 # else
50 #  define	RDR_SIZE	127
51 # endif
52 #endif
53 #ifndef HOSTMAP_SIZE
54 # ifdef LARGE_NAT
55 #  define	HOSTMAP_SIZE	8191
56 # else
57 #  define	HOSTMAP_SIZE	2047
58 # endif
59 #endif
60 #ifndef NAT_TABLE_MAX
61 /*
62  * This is newly introduced and for the sake of "least surprise", the numbers
63  * present aren't what we'd normally use for creating a proper hash table.
64  */
65 # ifdef	LARGE_NAT
66 #  define	NAT_TABLE_MAX	180000
67 # else
68 #  define	NAT_TABLE_MAX	30000
69 # endif
70 #endif
71 #ifndef NAT_TABLE_SZ
72 # ifdef LARGE_NAT
73 #  define	NAT_TABLE_SZ	16383
74 # else
75 #  define	NAT_TABLE_SZ	2047
76 # endif
77 #endif
78 #ifndef	APR_LABELLEN
79 #define	APR_LABELLEN	16
80 #endif
81 #define	NAT_HW_CKSUM	0x80000000
82 
83 #define	DEF_NAT_AGE	1200     /* 10 minutes (600 seconds) */
84 
85 struct ipstate;
86 struct ap_session;
87 
88 typedef	struct	nat	{
89 	ipfmutex_t	nat_lock;
90 	struct	nat	*nat_next;
91 	struct	nat	**nat_pnext;
92 	struct	nat	*nat_hnext[2];
93 	struct	nat	**nat_phnext[2];
94 	struct	hostmap	*nat_hm;
95 	void		*nat_data;
96 	struct	nat	**nat_me;
97 	struct	ipstate	*nat_state;
98 	struct	ap_session	*nat_aps;		/* proxy session */
99 	frentry_t	*nat_fr;	/* filter rule ptr if appropriate */
100 	struct	ipnat	*nat_ptr;	/* pointer back to the rule */
101 	void		*nat_ifps[2];
102 	void		*nat_sync;
103 	ipftqent_t	nat_tqe;
104 	u_32_t		nat_flags;
105 	u_32_t		nat_sumd[2];	/* ip checksum delta for data segment*/
106 	u_32_t		nat_ipsumd;	/* ip checksum delta for ip header */
107 	u_32_t		nat_mssclamp;	/* if != zero clamp MSS to this */
108 	i6addr_t	nat_inip6;
109 	i6addr_t	nat_outip6;
110 	i6addr_t	nat_oip6;		/* other ip */
111 	U_QUAD_T	nat_pkts[2];
112 	U_QUAD_T	nat_bytes[2];
113 	union	{
114 		udpinfo_t	nat_unu;
115 		tcpinfo_t	nat_unt;
116 		icmpinfo_t	nat_uni;
117 		greinfo_t	nat_ugre;
118 	} nat_un;
119 	u_short		nat_oport;		/* other port */
120 	u_short		nat_use;
121 	u_char		nat_p;			/* protocol for NAT */
122 	int		nat_dir;
123 	int		nat_ref;		/* reference count */
124 	int		nat_hv[2];
125 	char		nat_ifnames[2][LIFNAMSIZ];
126 	int		nat_rev;		/* 0 = forward, 1 = reverse */
127 	int		nat_redir;		/* copy of in_redir */
128 	u_32_t		nat_seqnext[2];
129 } nat_t;
130 
131 #define	nat_inip	nat_inip6.in4
132 #define	nat_outip	nat_outip6.in4
133 #define	nat_oip		nat_oip6.in4
134 #define	nat_age		nat_tqe.tqe_die
135 #define	nat_inport	nat_un.nat_unt.ts_sport
136 #define	nat_outport	nat_un.nat_unt.ts_dport
137 #define	nat_type	nat_un.nat_uni.ici_type
138 #define	nat_seq		nat_un.nat_uni.ici_seq
139 #define	nat_id		nat_un.nat_uni.ici_id
140 #define	nat_tcpstate	nat_tqe.tqe_state
141 #define	nat_die		nat_tqe.tqe_die
142 #define	nat_touched	nat_tqe.tqe_touched
143 
144 /*
145  * Values for nat_dir
146  */
147 #define	NAT_INBOUND	0
148 #define	NAT_OUTBOUND	1
149 
150 /*
151  * Definitions for nat_flags
152  */
153 #define	NAT_TCP		0x0001	/* IPN_TCP */
154 #define	NAT_UDP		0x0002	/* IPN_UDP */
155 #define	NAT_ICMPERR	0x0004	/* IPN_ICMPERR */
156 #define	NAT_ICMPQUERY	0x0008	/* IPN_ICMPQUERY */
157 #define	NAT_SEARCH	0x0010
158 #define	NAT_SLAVE	0x0020	/* Slave connection for a proxy */
159 #define	NAT_NOTRULEPORT	0x0040	/* Don't use the port # in the NAT rule */
160 
161 #define	NAT_TCPUDP	(NAT_TCP|NAT_UDP)
162 #define	NAT_TCPUDPICMP	(NAT_TCP|NAT_UDP|NAT_ICMPERR)
163 #define	NAT_TCPUDPICMPQ	(NAT_TCP|NAT_UDP|NAT_ICMPQUERY)
164 #define	NAT_FROMRULE	(NAT_TCP|NAT_UDP)
165 
166 /* 0x0100 reserved for FI_W_SPORT */
167 /* 0x0200 reserved for FI_W_DPORT */
168 /* 0x0400 reserved for FI_W_SADDR */
169 /* 0x0800 reserved for FI_W_DADDR */
170 /* 0x1000 reserved for FI_W_NEWFR */
171 /* 0x2000 reserved for SI_CLONE */
172 /* 0x4000 reserved for SI_CLONED */
173 /* 0x8000 reserved for SI_IGNOREPKT */
174 
175 #define	NAT_DEBUG	0x800000
176 
177 typedef	struct	ipnat	{
178 	ipfmutex_t	in_lock;
179 	struct	ipnat	*in_next;		/* NAT rule list next */
180 	struct	ipnat	*in_rnext;		/* rdr rule hash next */
181 	struct	ipnat	**in_prnext;		/* prior rdr next ptr */
182 	struct	ipnat	*in_mnext;		/* map rule hash next */
183 	struct	ipnat	**in_pmnext;		/* prior map next ptr */
184 	struct	ipftq	*in_tqehead[2];
185 	void		*in_ifps[2];
186 	void		*in_apr;
187 	char		*in_comment;
188 	i6addr_t	in_next6;
189 	u_long		in_space;
190 	u_long		in_hits;
191 	u_int		in_use;
192 	u_int		in_hv;
193 	int		in_flineno;		/* conf. file line number */
194 	u_short		in_pnext;
195 	u_char		in_v;
196 	u_char		in_xxx;
197 	/* From here to the end is covered by IPN_CMPSIZ */
198 	u_32_t		in_flags;
199 	u_32_t		in_mssclamp;		/* if != 0 clamp MSS to this */
200 	u_int		in_age[2];
201 	int		in_redir;		/* see below for values */
202 	int		in_p;			/* protocol. */
203 	i6addr_t	in_in[2];
204 	i6addr_t	in_out[2];
205 	i6addr_t	in_src[2];
206 	frtuc_t		in_tuc;
207 	u_short		in_port[2];
208 	u_short		in_ppip;		/* ports per IP. */
209 	u_short		in_ippip;		/* IP #'s per IP# */
210 	char		in_ifnames[2][LIFNAMSIZ];
211 	char		in_plabel[APR_LABELLEN];	/* proxy label. */
212 	ipftag_t	in_tag;
213 } ipnat_t;
214 
215 #define	in_pmin		in_port[0]	/* Also holds static redir port */
216 #define	in_pmax		in_port[1]
217 #define	in_nextip	in_next6.in4
218 #define	in_nip		in_next6.in4.s_addr
219 #define	in_inip		in_in[0].in4.s_addr
220 #define	in_inmsk	in_in[1].in4.s_addr
221 #define	in_outip	in_out[0].in4.s_addr
222 #define	in_outmsk	in_out[1].in4.s_addr
223 #define	in_srcip	in_src[0].in4.s_addr
224 #define	in_srcmsk	in_src[1].in4.s_addr
225 #define	in_scmp		in_tuc.ftu_scmp
226 #define	in_dcmp		in_tuc.ftu_dcmp
227 #define	in_stop		in_tuc.ftu_stop
228 #define	in_dtop		in_tuc.ftu_dtop
229 #define	in_sport	in_tuc.ftu_sport
230 #define	in_dport	in_tuc.ftu_dport
231 
232 /*
233  * Bit definitions for in_flags
234  */
235 #define	IPN_ANY		0x00000
236 #define	IPN_TCP		0x00001
237 #define	IPN_UDP		0x00002
238 #define	IPN_TCPUDP	(IPN_TCP|IPN_UDP)
239 #define	IPN_ICMPERR	0x00004
240 #define	IPN_TCPUDPICMP	(IPN_TCP|IPN_UDP|IPN_ICMPERR)
241 #define	IPN_ICMPQUERY	0x00008
242 #define	IPN_TCPUDPICMPQ	(IPN_TCP|IPN_UDP|IPN_ICMPQUERY)
243 #define	IPN_RF		(IPN_TCPUDP|IPN_DELETE|IPN_ICMPERR)
244 #define	IPN_AUTOPORTMAP	0x00010
245 #define	IPN_IPRANGE	0x00020
246 #define	IPN_FILTER	0x00040
247 #define	IPN_SPLIT	0x00080
248 #define	IPN_ROUNDR	0x00100
249 #define	IPN_NOTSRC	0x04000
250 #define	IPN_NOTDST	0x08000
251 #define	IPN_DYNSRCIP	0x10000	/* dynamic src IP# */
252 #define	IPN_DYNDSTIP	0x20000	/* dynamic dst IP# */
253 #define	IPN_DELETE	0x40000
254 #define	IPN_STICKY	0x80000
255 #define	IPN_FRAG	0x100000
256 #define	IPN_FIXEDDPORT	0x200000
257 #define	IPN_FINDFORWARD	0x400000
258 #define	IPN_IN		0x800000
259 #define	IPN_SEQUENTIAL	0x1000000
260 #define	IPN_USERFLAGS	(IPN_TCPUDP|IPN_AUTOPORTMAP|IPN_IPRANGE|IPN_SPLIT|\
261 			 IPN_ROUNDR|IPN_FILTER|IPN_NOTSRC|IPN_NOTDST|\
262 			 IPN_FRAG|IPN_STICKY|IPN_FIXEDDPORT|IPN_ICMPQUERY|\
263 			 IPN_SEQUENTIAL)
264 
265 /*
266  * Values for in_redir
267  */
268 #define	NAT_MAP		0x01
269 #define	NAT_REDIRECT	0x02
270 #define	NAT_BIMAP	(NAT_MAP|NAT_REDIRECT)
271 #define	NAT_MAPBLK	0x04
272 
273 #define	MAPBLK_MINPORT	1024	/* don't use reserved ports for src port */
274 #define	USABLE_PORTS	(65536 - MAPBLK_MINPORT)
275 
276 #define	IPN_CMPSIZ	(sizeof(ipnat_t) - offsetof(ipnat_t, in_flags))
277 
278 typedef	struct	natlookup {
279 	struct	in_addr	nl_inip;
280 	struct	in_addr	nl_outip;
281 	struct	in_addr	nl_realip;
282 	int	nl_flags;
283 	u_short	nl_inport;
284 	u_short	nl_outport;
285 	u_short	nl_realport;
286 } natlookup_t;
287 
288 
289 typedef struct  nat_save    {
290 	void	*ipn_next;
291 	struct	nat	ipn_nat;
292 	struct	ipnat	ipn_ipnat;
293 	struct	frentry ipn_fr;
294 	int	ipn_dsize;
295 	char	ipn_data[4];
296 } nat_save_t;
297 
298 #define	ipn_rule	ipn_nat.nat_fr
299 
300 typedef	struct	natget	{
301 	void	*ng_ptr;
302 	int	ng_sz;
303 } natget_t;
304 
305 
306 /*
307  * This structure gets used to help NAT sessions keep the same NAT rule (and
308  * thus translation for IP address) when:
309  * (a) round-robin redirects are in use
310  * (b) different IP add
311  */
312 typedef	struct	hostmap	{
313 	struct	hostmap	*hm_hnext;
314 	struct	hostmap	**hm_phnext;
315 	struct	hostmap	*hm_next;
316 	struct	hostmap	**hm_pnext;
317 	struct	ipnat	*hm_ipnat;
318 	struct	in_addr	hm_srcip;
319 	struct	in_addr	hm_dstip;
320 	struct	in_addr	hm_mapip;
321 	u_32_t		hm_port;
322 	int		hm_ref;
323 } hostmap_t;
324 
325 
326 /*
327  * Structure used to pass information in to nat_newmap and nat_newrdr.
328  */
329 typedef struct	natinfo	{
330 	ipnat_t		*nai_np;
331 	u_32_t		nai_sum1;
332 	u_32_t		nai_sum2;
333 	u_32_t		nai_nflags;
334 	u_32_t		nai_flags;
335 	struct	in_addr	nai_ip;
336 	u_short		nai_port;
337 	u_short		nai_nport;
338 	u_short		nai_sport;
339 	u_short		nai_dport;
340 } natinfo_t;
341 
342 
343 typedef	struct	natstat	{
344 	u_long	ns_mapped[2];
345 	u_long	ns_rules;
346 	u_long	ns_added;
347 	u_long	ns_expire;
348 	u_long	ns_inuse;
349 	u_long	ns_logged;
350 	u_long	ns_logfail;
351 	u_long	ns_memfail;
352 	u_long	ns_badnat;
353 	u_long	ns_addtrpnt;
354 	nat_t	**ns_table[2];
355 	hostmap_t **ns_maptable;
356 	ipnat_t	*ns_list;
357 	void	*ns_apslist;
358 	u_int	ns_wilds;
359 	u_int	ns_nattab_sz;
360 	u_int	ns_nattab_max;
361 	u_int	ns_rultab_sz;
362 	u_int	ns_rdrtab_sz;
363 	u_int	ns_trpntab_sz;
364 	u_int	ns_hostmap_sz;
365 	nat_t	*ns_instances;
366 	hostmap_t *ns_maplist;
367 	u_long	*ns_bucketlen[2];
368 	u_long	ns_ticks;
369 	u_int	ns_orphans;
370 } natstat_t;
371 
372 typedef	struct	natlog {
373 	struct	in_addr	nl_origip;
374 	struct	in_addr	nl_outip;
375 	struct	in_addr	nl_inip;
376 	u_short	nl_origport;
377 	u_short	nl_outport;
378 	u_short	nl_inport;
379 	u_short	nl_type;
380 	int	nl_rule;
381 	U_QUAD_T	nl_pkts[2];
382 	U_QUAD_T	nl_bytes[2];
383 	u_char	nl_p;
384 } natlog_t;
385 
386 
387 #define	NL_NEWMAP	NAT_MAP
388 #define	NL_NEWRDR	NAT_REDIRECT
389 #define	NL_NEWBIMAP	NAT_BIMAP
390 #define	NL_NEWBLOCK	NAT_MAPBLK
391 #define	NL_DESTROY	0xfffc
392 #define	NL_CLONE	0xfffd
393 #define	NL_FLUSH	0xfffe
394 #define	NL_EXPIRE	0xffff
395 
396 #define	NAT_HASH_FN(k,l,m)	(((k) + ((k) >> 12) + l) % (m))
397 
398 #define	LONG_SUM(in)	(((in) & 0xffff) + ((in) >> 16))
399 
400 #define	CALC_SUMD(s1, s2, sd) { \
401 			    (s1) = ((s1) & 0xffff) + ((s1) >> 16); \
402 			    (s2) = ((s2) & 0xffff) + ((s2) >> 16); \
403 			    /* Do it twice */ \
404 			    (s1) = ((s1) & 0xffff) + ((s1) >> 16); \
405 			    (s2) = ((s2) & 0xffff) + ((s2) >> 16); \
406 			    /* Because ~1 == -2, We really need ~1 == -1 */ \
407 			    if ((s1) > (s2)) (s2)--; \
408 			    (sd) = (s2) - (s1); \
409 			    (sd) = ((sd) & 0xffff) + ((sd) >> 16); }
410 
411 #define	NAT_SYSSPACE		0x80000000
412 #define	NAT_LOCKHELD		0x40000000
413 
414 
415 extern	u_int	ipf_nattable_sz;
416 extern	u_int	ipf_nattable_max;
417 extern	u_int	ipf_natrules_sz;
418 extern	u_int	ipf_rdrrules_sz;
419 extern	u_int	ipf_hostmap_sz;
420 extern	u_int	fr_nat_maxbucket;
421 extern	u_int	fr_nat_maxbucket_reset;
422 extern	int	fr_nat_lock;
423 extern	int	fr_nat_doflush;
424 extern	void	fr_natsync __P((void *));
425 extern	u_long	fr_defnatage;
426 extern	u_long	fr_defnaticmpage;
427 extern	u_long	fr_defnatipage;
428 	/* nat_table[0] -> hashed list sorted by inside (ip, port) */
429 	/* nat_table[1] -> hashed list sorted by outside (ip, port) */
430 extern	nat_t	**nat_table[2];
431 extern	nat_t	*nat_instances;
432 extern	ipnat_t	*nat_list;
433 extern	ipnat_t	**nat_rules;
434 extern	ipnat_t	**rdr_rules;
435 extern	ipftq_t	*nat_utqe;
436 extern	natstat_t	nat_stats;
437 
438 #if defined(__OpenBSD__)
439 extern	void	nat_ifdetach __P((void *));
440 #endif
441 extern	int	fr_nat_ioctl __P((caddr_t, ioctlcmd_t, int, int, void *));
442 extern	int	fr_natinit __P((void));
443 extern	nat_t	*nat_new __P((fr_info_t *, ipnat_t *, nat_t **, u_int, int));
444 extern	nat_t	*nat_outlookup __P((fr_info_t *, u_int, u_int, struct in_addr,
445 				 struct in_addr));
446 extern	void	fix_datacksum __P((u_short *, u_32_t));
447 extern	nat_t	*nat_inlookup __P((fr_info_t *, u_int, u_int, struct in_addr,
448 				struct in_addr));
449 extern	nat_t	*nat_tnlookup __P((fr_info_t *, int));
450 extern	nat_t	*nat_maplookup __P((void *, u_int, struct in_addr,
451 				struct in_addr));
452 extern	nat_t	*nat_lookupredir __P((natlookup_t *));
453 extern	nat_t	*nat_icmperrorlookup __P((fr_info_t *, int));
454 extern	nat_t	*nat_icmperror __P((fr_info_t *, u_int *, int));
455 extern	void	nat_delete __P((struct nat *, int));
456 extern	int	nat_insert __P((nat_t *, int));
457 
458 extern	int	fr_checknatout __P((fr_info_t *, u_32_t *));
459 extern	int	fr_natout __P((fr_info_t *, nat_t *, int, u_32_t));
460 extern	int	fr_checknatin __P((fr_info_t *, u_32_t *));
461 extern	int	fr_natin __P((fr_info_t *, nat_t *, int, u_32_t));
462 extern	void	fr_natunload __P((void));
463 extern	void	fr_natexpire __P((void));
464 extern	void	nat_log __P((struct nat *, u_int));
465 extern	void	fix_incksum __P((fr_info_t *, u_short *, u_32_t));
466 extern	void	fix_outcksum __P((fr_info_t *, u_short *, u_32_t));
467 extern	void	fr_ipnatderef __P((ipnat_t **));
468 extern	void	fr_natderef __P((nat_t **));
469 extern	u_short	*nat_proto __P((fr_info_t *, nat_t *, u_int));
470 extern	void	nat_update __P((fr_info_t *, nat_t *, ipnat_t *));
471 extern	void	fr_setnatqueue __P((nat_t *, int));
472 extern	void	fr_hostmapdel __P((hostmap_t **));
473 
474 #endif /* __IP_NAT_H__ */
475