xref: /freebsd/sys/netpfil/pf/pf_lb.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2001 Daniel Hartmeier
5  * Copyright (c) 2002 - 2008 Henning Brauer
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  *    - Redistributions of source code must retain the above copyright
13  *      notice, this list of conditions and the following disclaimer.
14  *    - Redistributions in binary form must reproduce the above
15  *      copyright notice, this list of conditions and the following
16  *      disclaimer in the documentation and/or other materials provided
17  *      with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
25  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
27  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
29  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  *
32  * Effort sponsored in part by the Defense Advanced Research Projects
33  * Agency (DARPA) and Air Force Research Laboratory, Air Force
34  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
35  *
36  *	$OpenBSD: pf_lb.c,v 1.2 2009/02/12 02:13:15 sthen Exp $
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "opt_pf.h"
43 #include "opt_inet.h"
44 #include "opt_inet6.h"
45 
46 #include <sys/param.h>
47 #include <sys/lock.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.h>
50 #include <sys/sysctl.h>
51 
52 #include <net/if.h>
53 #include <net/vnet.h>
54 #include <net/pfvar.h>
55 #include <net/if_pflog.h>
56 
57 #define DPFPRINTF(n, x)	if (V_pf_status.debug >= (n)) printf x
58 
59 static void		 pf_hash(struct pf_addr *, struct pf_addr *,
60 			    struct pf_poolhashkey *, sa_family_t);
61 static struct pf_krule	*pf_match_translation(struct pf_pdesc *, struct mbuf *,
62 			    int, int, struct pfi_kkif *,
63 			    struct pf_addr *, u_int16_t, struct pf_addr *,
64 			    uint16_t, int, struct pf_kanchor_stackframe *);
65 static int pf_get_sport(sa_family_t, uint8_t, struct pf_krule *,
66     struct pf_addr *, uint16_t, struct pf_addr *, uint16_t, struct pf_addr *,
67     uint16_t *, uint16_t, uint16_t, struct pf_ksrc_node **);
68 
69 #define mix(a,b,c) \
70 	do {					\
71 		a -= b; a -= c; a ^= (c >> 13);	\
72 		b -= c; b -= a; b ^= (a << 8);	\
73 		c -= a; c -= b; c ^= (b >> 13);	\
74 		a -= b; a -= c; a ^= (c >> 12);	\
75 		b -= c; b -= a; b ^= (a << 16);	\
76 		c -= a; c -= b; c ^= (b >> 5);	\
77 		a -= b; a -= c; a ^= (c >> 3);	\
78 		b -= c; b -= a; b ^= (a << 10);	\
79 		c -= a; c -= b; c ^= (b >> 15);	\
80 	} while (0)
81 
82 /*
83  * hash function based on bridge_hash in if_bridge.c
84  */
85 static void
86 pf_hash(struct pf_addr *inaddr, struct pf_addr *hash,
87     struct pf_poolhashkey *key, sa_family_t af)
88 {
89 	u_int32_t	a = 0x9e3779b9, b = 0x9e3779b9, c = key->key32[0];
90 
91 	switch (af) {
92 #ifdef INET
93 	case AF_INET:
94 		a += inaddr->addr32[0];
95 		b += key->key32[1];
96 		mix(a, b, c);
97 		hash->addr32[0] = c + key->key32[2];
98 		break;
99 #endif /* INET */
100 #ifdef INET6
101 	case AF_INET6:
102 		a += inaddr->addr32[0];
103 		b += inaddr->addr32[2];
104 		mix(a, b, c);
105 		hash->addr32[0] = c;
106 		a += inaddr->addr32[1];
107 		b += inaddr->addr32[3];
108 		c += key->key32[1];
109 		mix(a, b, c);
110 		hash->addr32[1] = c;
111 		a += inaddr->addr32[2];
112 		b += inaddr->addr32[1];
113 		c += key->key32[2];
114 		mix(a, b, c);
115 		hash->addr32[2] = c;
116 		a += inaddr->addr32[3];
117 		b += inaddr->addr32[0];
118 		c += key->key32[3];
119 		mix(a, b, c);
120 		hash->addr32[3] = c;
121 		break;
122 #endif /* INET6 */
123 	}
124 }
125 
126 static struct pf_krule *
127 pf_match_translation(struct pf_pdesc *pd, struct mbuf *m, int off,
128     int direction, struct pfi_kkif *kif, struct pf_addr *saddr, u_int16_t sport,
129     struct pf_addr *daddr, uint16_t dport, int rs_num,
130     struct pf_kanchor_stackframe *anchor_stack)
131 {
132 	struct pf_krule		*r, *rm = NULL;
133 	struct pf_kruleset	*ruleset = NULL;
134 	int			 tag = -1;
135 	int			 rtableid = -1;
136 	int			 asd = 0;
137 
138 	r = TAILQ_FIRST(pf_main_ruleset.rules[rs_num].active.ptr);
139 	while (r && rm == NULL) {
140 		struct pf_rule_addr	*src = NULL, *dst = NULL;
141 		struct pf_addr_wrap	*xdst = NULL;
142 
143 		if (r->action == PF_BINAT && direction == PF_IN) {
144 			src = &r->dst;
145 			if (r->rpool.cur != NULL)
146 				xdst = &r->rpool.cur->addr;
147 		} else {
148 			src = &r->src;
149 			dst = &r->dst;
150 		}
151 
152 		counter_u64_add(r->evaluations, 1);
153 		if (pfi_kkif_match(r->kif, kif) == r->ifnot)
154 			r = r->skip[PF_SKIP_IFP].ptr;
155 		else if (r->direction && r->direction != direction)
156 			r = r->skip[PF_SKIP_DIR].ptr;
157 		else if (r->af && r->af != pd->af)
158 			r = r->skip[PF_SKIP_AF].ptr;
159 		else if (r->proto && r->proto != pd->proto)
160 			r = r->skip[PF_SKIP_PROTO].ptr;
161 		else if (PF_MISMATCHAW(&src->addr, saddr, pd->af,
162 		    src->neg, kif, M_GETFIB(m)))
163 			r = r->skip[src == &r->src ? PF_SKIP_SRC_ADDR :
164 			    PF_SKIP_DST_ADDR].ptr;
165 		else if (src->port_op && !pf_match_port(src->port_op,
166 		    src->port[0], src->port[1], sport))
167 			r = r->skip[src == &r->src ? PF_SKIP_SRC_PORT :
168 			    PF_SKIP_DST_PORT].ptr;
169 		else if (dst != NULL &&
170 		    PF_MISMATCHAW(&dst->addr, daddr, pd->af, dst->neg, NULL,
171 		    M_GETFIB(m)))
172 			r = r->skip[PF_SKIP_DST_ADDR].ptr;
173 		else if (xdst != NULL && PF_MISMATCHAW(xdst, daddr, pd->af,
174 		    0, NULL, M_GETFIB(m)))
175 			r = TAILQ_NEXT(r, entries);
176 		else if (dst != NULL && dst->port_op &&
177 		    !pf_match_port(dst->port_op, dst->port[0],
178 		    dst->port[1], dport))
179 			r = r->skip[PF_SKIP_DST_PORT].ptr;
180 		else if (r->match_tag && !pf_match_tag(m, r, &tag,
181 		    pd->pf_mtag ? pd->pf_mtag->tag : 0))
182 			r = TAILQ_NEXT(r, entries);
183 		else if (r->os_fingerprint != PF_OSFP_ANY && (pd->proto !=
184 		    IPPROTO_TCP || !pf_osfp_match(pf_osfp_fingerprint(pd, m,
185 		    off, pd->hdr.tcp), r->os_fingerprint)))
186 			r = TAILQ_NEXT(r, entries);
187 		else {
188 			if (r->tag)
189 				tag = r->tag;
190 			if (r->rtableid >= 0)
191 				rtableid = r->rtableid;
192 			if (r->anchor == NULL) {
193 				rm = r;
194 			} else
195 				pf_step_into_anchor(anchor_stack, &asd,
196 				    &ruleset, rs_num, &r, NULL, NULL);
197 		}
198 		if (r == NULL)
199 			pf_step_out_of_anchor(anchor_stack, &asd, &ruleset,
200 			    rs_num, &r, NULL, NULL);
201 	}
202 
203 	if (tag > 0 && pf_tag_packet(m, pd, tag))
204 		return (NULL);
205 	if (rtableid >= 0)
206 		M_SETFIB(m, rtableid);
207 
208 	if (rm != NULL && (rm->action == PF_NONAT ||
209 	    rm->action == PF_NORDR || rm->action == PF_NOBINAT))
210 		return (NULL);
211 	return (rm);
212 }
213 
214 static int
215 pf_get_sport(sa_family_t af, u_int8_t proto, struct pf_krule *r,
216     struct pf_addr *saddr, uint16_t sport, struct pf_addr *daddr,
217     uint16_t dport, struct pf_addr *naddr, uint16_t *nport, uint16_t low,
218     uint16_t high, struct pf_ksrc_node **sn)
219 {
220 	struct pf_state_key_cmp	key;
221 	struct pf_addr		init_addr;
222 
223 	bzero(&init_addr, sizeof(init_addr));
224 	if (pf_map_addr(af, r, saddr, naddr, &init_addr, sn))
225 		return (1);
226 
227 	bzero(&key, sizeof(key));
228 	key.af = af;
229 	key.proto = proto;
230 	key.port[0] = dport;
231 	PF_ACPY(&key.addr[0], daddr, key.af);
232 
233 	do {
234 		PF_ACPY(&key.addr[1], naddr, key.af);
235 
236 		/*
237 		 * port search; start random, step;
238 		 * similar 2 portloop in in_pcbbind
239 		 */
240 		if (!(proto == IPPROTO_TCP || proto == IPPROTO_UDP ||
241 		    proto == IPPROTO_ICMP) || (low == 0 && high == 0)) {
242 			/*
243 			 * XXX bug: icmp states don't use the id on both sides.
244 			 * (traceroute -I through nat)
245 			 */
246 			key.port[1] = sport;
247 			if (pf_find_state_all(&key, PF_IN, NULL) == NULL) {
248 				*nport = sport;
249 				return (0);
250 			}
251 		} else if (low == high) {
252 			key.port[1] = htons(low);
253 			if (pf_find_state_all(&key, PF_IN, NULL) == NULL) {
254 				*nport = htons(low);
255 				return (0);
256 			}
257 		} else {
258 			uint32_t tmp;
259 			uint16_t cut;
260 
261 			if (low > high) {
262 				tmp = low;
263 				low = high;
264 				high = tmp;
265 			}
266 			/* low < high */
267 			cut = arc4random() % (1 + high - low) + low;
268 			/* low <= cut <= high */
269 			for (tmp = cut; tmp <= high && tmp <= 0xffff; ++tmp) {
270 				key.port[1] = htons(tmp);
271 				if (pf_find_state_all(&key, PF_IN, NULL) ==
272 				    NULL) {
273 					*nport = htons(tmp);
274 					return (0);
275 				}
276 			}
277 			tmp = cut;
278 			for (tmp -= 1; tmp >= low && tmp <= 0xffff; --tmp) {
279 				key.port[1] = htons(tmp);
280 				if (pf_find_state_all(&key, PF_IN, NULL) ==
281 				    NULL) {
282 					*nport = htons(tmp);
283 					return (0);
284 				}
285 			}
286 		}
287 
288 		switch (r->rpool.opts & PF_POOL_TYPEMASK) {
289 		case PF_POOL_RANDOM:
290 		case PF_POOL_ROUNDROBIN:
291 			/*
292 			 * pick a different source address since we're out
293 			 * of free port choices for the current one.
294 			 */
295 			if (pf_map_addr(af, r, saddr, naddr, &init_addr, sn))
296 				return (1);
297 			break;
298 		case PF_POOL_NONE:
299 		case PF_POOL_SRCHASH:
300 		case PF_POOL_BITMASK:
301 		default:
302 			return (1);
303 		}
304 	} while (! PF_AEQ(&init_addr, naddr, af) );
305 	return (1);					/* none available */
306 }
307 
308 static int
309 pf_get_mape_sport(sa_family_t af, u_int8_t proto, struct pf_krule *r,
310     struct pf_addr *saddr, uint16_t sport, struct pf_addr *daddr,
311     uint16_t dport, struct pf_addr *naddr, uint16_t *nport,
312     struct pf_ksrc_node **sn)
313 {
314 	uint16_t psmask, low, highmask;
315 	uint16_t i, ahigh, cut;
316 	int ashift, psidshift;
317 
318 	ashift = 16 - r->rpool.mape.offset;
319 	psidshift = ashift - r->rpool.mape.psidlen;
320 	psmask = r->rpool.mape.psid & ((1U << r->rpool.mape.psidlen) - 1);
321 	psmask = psmask << psidshift;
322 	highmask = (1U << psidshift) - 1;
323 
324 	ahigh = (1U << r->rpool.mape.offset) - 1;
325 	cut = arc4random() & ahigh;
326 	if (cut == 0)
327 		cut = 1;
328 
329 	for (i = cut; i <= ahigh; i++) {
330 		low = (i << ashift) | psmask;
331 		if (!pf_get_sport(af, proto, r, saddr, sport, daddr, dport,
332 		    naddr, nport, low, low | highmask, sn))
333 			return (0);
334 	}
335 	for (i = cut - 1; i > 0; i--) {
336 		low = (i << ashift) | psmask;
337 		if (!pf_get_sport(af, proto, r, saddr, sport, daddr, dport,
338 		    naddr, nport, low, low | highmask, sn))
339 			return (0);
340 	}
341 	return (1);
342 }
343 
344 int
345 pf_map_addr(sa_family_t af, struct pf_krule *r, struct pf_addr *saddr,
346     struct pf_addr *naddr, struct pf_addr *init_addr, struct pf_ksrc_node **sn)
347 {
348 	struct pf_kpool		*rpool = &r->rpool;
349 	struct pf_addr		*raddr = NULL, *rmask = NULL;
350 
351 	/* Try to find a src_node if none was given and this
352 	   is a sticky-address rule. */
353 	if (*sn == NULL && r->rpool.opts & PF_POOL_STICKYADDR &&
354 	    (r->rpool.opts & PF_POOL_TYPEMASK) != PF_POOL_NONE)
355 		*sn = pf_find_src_node(saddr, r, af, 0);
356 
357 	/* If a src_node was found or explicitly given and it has a non-zero
358 	   route address, use this address. A zeroed address is found if the
359 	   src node was created just a moment ago in pf_create_state and it
360 	   needs to be filled in with routing decision calculated here. */
361 	if (*sn != NULL && !PF_AZERO(&(*sn)->raddr, af)) {
362 		/* If the supplied address is the same as the current one we've
363 		 * been asked before, so tell the caller that there's no other
364 		 * address to be had. */
365 		if (PF_AEQ(naddr, &(*sn)->raddr, af))
366 			return (1);
367 
368 		PF_ACPY(naddr, &(*sn)->raddr, af);
369 		if (V_pf_status.debug >= PF_DEBUG_MISC) {
370 			printf("pf_map_addr: src tracking maps ");
371 			pf_print_host(saddr, 0, af);
372 			printf(" to ");
373 			pf_print_host(naddr, 0, af);
374 			printf("\n");
375 		}
376 		return (0);
377 	}
378 
379 	/* Find the route using chosen algorithm. Store the found route
380 	   in src_node if it was given or found. */
381 	if (rpool->cur->addr.type == PF_ADDR_NOROUTE)
382 		return (1);
383 	if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
384 		switch (af) {
385 #ifdef INET
386 		case AF_INET:
387 			if (rpool->cur->addr.p.dyn->pfid_acnt4 < 1 &&
388 			    (rpool->opts & PF_POOL_TYPEMASK) !=
389 			    PF_POOL_ROUNDROBIN)
390 				return (1);
391 			 raddr = &rpool->cur->addr.p.dyn->pfid_addr4;
392 			 rmask = &rpool->cur->addr.p.dyn->pfid_mask4;
393 			break;
394 #endif /* INET */
395 #ifdef INET6
396 		case AF_INET6:
397 			if (rpool->cur->addr.p.dyn->pfid_acnt6 < 1 &&
398 			    (rpool->opts & PF_POOL_TYPEMASK) !=
399 			    PF_POOL_ROUNDROBIN)
400 				return (1);
401 			raddr = &rpool->cur->addr.p.dyn->pfid_addr6;
402 			rmask = &rpool->cur->addr.p.dyn->pfid_mask6;
403 			break;
404 #endif /* INET6 */
405 		}
406 	} else if (rpool->cur->addr.type == PF_ADDR_TABLE) {
407 		if ((rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_ROUNDROBIN)
408 			return (1); /* unsupported */
409 	} else {
410 		raddr = &rpool->cur->addr.v.a.addr;
411 		rmask = &rpool->cur->addr.v.a.mask;
412 	}
413 
414 	switch (rpool->opts & PF_POOL_TYPEMASK) {
415 	case PF_POOL_NONE:
416 		PF_ACPY(naddr, raddr, af);
417 		break;
418 	case PF_POOL_BITMASK:
419 		PF_POOLMASK(naddr, raddr, rmask, saddr, af);
420 		break;
421 	case PF_POOL_RANDOM:
422 		if (init_addr != NULL && PF_AZERO(init_addr, af)) {
423 			switch (af) {
424 #ifdef INET
425 			case AF_INET:
426 				rpool->counter.addr32[0] = htonl(arc4random());
427 				break;
428 #endif /* INET */
429 #ifdef INET6
430 			case AF_INET6:
431 				if (rmask->addr32[3] != 0xffffffff)
432 					rpool->counter.addr32[3] =
433 					    htonl(arc4random());
434 				else
435 					break;
436 				if (rmask->addr32[2] != 0xffffffff)
437 					rpool->counter.addr32[2] =
438 					    htonl(arc4random());
439 				else
440 					break;
441 				if (rmask->addr32[1] != 0xffffffff)
442 					rpool->counter.addr32[1] =
443 					    htonl(arc4random());
444 				else
445 					break;
446 				if (rmask->addr32[0] != 0xffffffff)
447 					rpool->counter.addr32[0] =
448 					    htonl(arc4random());
449 				break;
450 #endif /* INET6 */
451 			}
452 			PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
453 			PF_ACPY(init_addr, naddr, af);
454 
455 		} else {
456 			PF_AINC(&rpool->counter, af);
457 			PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
458 		}
459 		break;
460 	case PF_POOL_SRCHASH:
461 	    {
462 		unsigned char hash[16];
463 
464 		pf_hash(saddr, (struct pf_addr *)&hash, &rpool->key, af);
465 		PF_POOLMASK(naddr, raddr, rmask, (struct pf_addr *)&hash, af);
466 		break;
467 	    }
468 	case PF_POOL_ROUNDROBIN:
469 	    {
470 		struct pf_kpooladdr *acur = rpool->cur;
471 
472 		/*
473 		 * XXXGL: in the round-robin case we need to store
474 		 * the round-robin machine state in the rule, thus
475 		 * forwarding thread needs to modify rule.
476 		 *
477 		 * This is done w/o locking, because performance is assumed
478 		 * more important than round-robin precision.
479 		 *
480 		 * In the simpliest case we just update the "rpool->cur"
481 		 * pointer. However, if pool contains tables or dynamic
482 		 * addresses, then "tblidx" is also used to store machine
483 		 * state. Since "tblidx" is int, concurrent access to it can't
484 		 * lead to inconsistence, only to lost of precision.
485 		 *
486 		 * Things get worse, if table contains not hosts, but
487 		 * prefixes. In this case counter also stores machine state,
488 		 * and for IPv6 address, counter can't be updated atomically.
489 		 * Probably, using round-robin on a table containing IPv6
490 		 * prefixes (or even IPv4) would cause a panic.
491 		 */
492 
493 		if (rpool->cur->addr.type == PF_ADDR_TABLE) {
494 			if (!pfr_pool_get(rpool->cur->addr.p.tbl,
495 			    &rpool->tblidx, &rpool->counter, af))
496 				goto get_addr;
497 		} else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
498 			if (!pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
499 			    &rpool->tblidx, &rpool->counter, af))
500 				goto get_addr;
501 		} else if (pf_match_addr(0, raddr, rmask, &rpool->counter, af))
502 			goto get_addr;
503 
504 	try_next:
505 		if (TAILQ_NEXT(rpool->cur, entries) == NULL)
506 			rpool->cur = TAILQ_FIRST(&rpool->list);
507 		else
508 			rpool->cur = TAILQ_NEXT(rpool->cur, entries);
509 		if (rpool->cur->addr.type == PF_ADDR_TABLE) {
510 			rpool->tblidx = -1;
511 			if (pfr_pool_get(rpool->cur->addr.p.tbl,
512 			    &rpool->tblidx, &rpool->counter, af)) {
513 				/* table contains no address of type 'af' */
514 				if (rpool->cur != acur)
515 					goto try_next;
516 				return (1);
517 			}
518 		} else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
519 			rpool->tblidx = -1;
520 			if (pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
521 			    &rpool->tblidx, &rpool->counter, af)) {
522 				/* table contains no address of type 'af' */
523 				if (rpool->cur != acur)
524 					goto try_next;
525 				return (1);
526 			}
527 		} else {
528 			raddr = &rpool->cur->addr.v.a.addr;
529 			rmask = &rpool->cur->addr.v.a.mask;
530 			PF_ACPY(&rpool->counter, raddr, af);
531 		}
532 
533 	get_addr:
534 		PF_ACPY(naddr, &rpool->counter, af);
535 		if (init_addr != NULL && PF_AZERO(init_addr, af))
536 			PF_ACPY(init_addr, naddr, af);
537 		PF_AINC(&rpool->counter, af);
538 		break;
539 	    }
540 	}
541 	if (*sn != NULL)
542 		PF_ACPY(&(*sn)->raddr, naddr, af);
543 
544 	if (V_pf_status.debug >= PF_DEBUG_MISC &&
545 	    (rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_NONE) {
546 		printf("pf_map_addr: selected address ");
547 		pf_print_host(naddr, 0, af);
548 		printf("\n");
549 	}
550 
551 	return (0);
552 }
553 
554 struct pf_krule *
555 pf_get_translation(struct pf_pdesc *pd, struct mbuf *m, int off, int direction,
556     struct pfi_kkif *kif, struct pf_ksrc_node **sn,
557     struct pf_state_key **skp, struct pf_state_key **nkp,
558     struct pf_addr *saddr, struct pf_addr *daddr,
559     uint16_t sport, uint16_t dport, struct pf_kanchor_stackframe *anchor_stack)
560 {
561 	struct pf_krule	*r = NULL;
562 	struct pf_addr	*naddr;
563 	uint16_t	*nport;
564 	uint16_t	 low, high;
565 
566 	PF_RULES_RASSERT();
567 	KASSERT(*skp == NULL, ("*skp not NULL"));
568 	KASSERT(*nkp == NULL, ("*nkp not NULL"));
569 
570 	if (direction == PF_OUT) {
571 		r = pf_match_translation(pd, m, off, direction, kif, saddr,
572 		    sport, daddr, dport, PF_RULESET_BINAT, anchor_stack);
573 		if (r == NULL)
574 			r = pf_match_translation(pd, m, off, direction, kif,
575 			    saddr, sport, daddr, dport, PF_RULESET_NAT,
576 			    anchor_stack);
577 	} else {
578 		r = pf_match_translation(pd, m, off, direction, kif, saddr,
579 		    sport, daddr, dport, PF_RULESET_RDR, anchor_stack);
580 		if (r == NULL)
581 			r = pf_match_translation(pd, m, off, direction, kif,
582 			    saddr, sport, daddr, dport, PF_RULESET_BINAT,
583 			    anchor_stack);
584 	}
585 
586 	if (r == NULL)
587 		return (NULL);
588 
589 	switch (r->action) {
590 	case PF_NONAT:
591 	case PF_NOBINAT:
592 	case PF_NORDR:
593 		return (NULL);
594 	}
595 
596 	*skp = pf_state_key_setup(pd, saddr, daddr, sport, dport);
597 	if (*skp == NULL)
598 		return (NULL);
599 	*nkp = pf_state_key_clone(*skp);
600 	if (*nkp == NULL) {
601 		uma_zfree(V_pf_state_key_z, *skp);
602 		*skp = NULL;
603 		return (NULL);
604 	}
605 
606 	/* XXX We only modify one side for now. */
607 	naddr = &(*nkp)->addr[1];
608 	nport = &(*nkp)->port[1];
609 
610 	switch (r->action) {
611 	case PF_NAT:
612 		if (pd->proto == IPPROTO_ICMP) {
613 			low  = 1;
614 			high = 65535;
615 		} else {
616 			low  = r->rpool.proxy_port[0];
617 			high = r->rpool.proxy_port[1];
618 		}
619 		if (r->rpool.mape.offset > 0) {
620 			if (pf_get_mape_sport(pd->af, pd->proto, r, saddr,
621 			    sport, daddr, dport, naddr, nport, sn)) {
622 				DPFPRINTF(PF_DEBUG_MISC,
623 				    ("pf: MAP-E port allocation (%u/%u/%u)"
624 				    " failed\n",
625 				    r->rpool.mape.offset,
626 				    r->rpool.mape.psidlen,
627 				    r->rpool.mape.psid));
628 				goto notrans;
629 			}
630 		} else if (pf_get_sport(pd->af, pd->proto, r, saddr, sport,
631 		    daddr, dport, naddr, nport, low, high, sn)) {
632 			DPFPRINTF(PF_DEBUG_MISC,
633 			    ("pf: NAT proxy port allocation (%u-%u) failed\n",
634 			    r->rpool.proxy_port[0], r->rpool.proxy_port[1]));
635 			goto notrans;
636 		}
637 		break;
638 	case PF_BINAT:
639 		switch (direction) {
640 		case PF_OUT:
641 			if (r->rpool.cur->addr.type == PF_ADDR_DYNIFTL){
642 				switch (pd->af) {
643 #ifdef INET
644 				case AF_INET:
645 					if (r->rpool.cur->addr.p.dyn->
646 					    pfid_acnt4 < 1)
647 						goto notrans;
648 					PF_POOLMASK(naddr,
649 					    &r->rpool.cur->addr.p.dyn->
650 					    pfid_addr4,
651 					    &r->rpool.cur->addr.p.dyn->
652 					    pfid_mask4, saddr, AF_INET);
653 					break;
654 #endif /* INET */
655 #ifdef INET6
656 				case AF_INET6:
657 					if (r->rpool.cur->addr.p.dyn->
658 					    pfid_acnt6 < 1)
659 						goto notrans;
660 					PF_POOLMASK(naddr,
661 					    &r->rpool.cur->addr.p.dyn->
662 					    pfid_addr6,
663 					    &r->rpool.cur->addr.p.dyn->
664 					    pfid_mask6, saddr, AF_INET6);
665 					break;
666 #endif /* INET6 */
667 				}
668 			} else
669 				PF_POOLMASK(naddr,
670 				    &r->rpool.cur->addr.v.a.addr,
671 				    &r->rpool.cur->addr.v.a.mask, saddr,
672 				    pd->af);
673 			break;
674 		case PF_IN:
675 			if (r->src.addr.type == PF_ADDR_DYNIFTL) {
676 				switch (pd->af) {
677 #ifdef INET
678 				case AF_INET:
679 					if (r->src.addr.p.dyn-> pfid_acnt4 < 1)
680 						goto notrans;
681 					PF_POOLMASK(naddr,
682 					    &r->src.addr.p.dyn->pfid_addr4,
683 					    &r->src.addr.p.dyn->pfid_mask4,
684 					    daddr, AF_INET);
685 					break;
686 #endif /* INET */
687 #ifdef INET6
688 				case AF_INET6:
689 					if (r->src.addr.p.dyn->pfid_acnt6 < 1)
690 						goto notrans;
691 					PF_POOLMASK(naddr,
692 					    &r->src.addr.p.dyn->pfid_addr6,
693 					    &r->src.addr.p.dyn->pfid_mask6,
694 					    daddr, AF_INET6);
695 					break;
696 #endif /* INET6 */
697 				}
698 			} else
699 				PF_POOLMASK(naddr, &r->src.addr.v.a.addr,
700 				    &r->src.addr.v.a.mask, daddr, pd->af);
701 			break;
702 		}
703 		break;
704 	case PF_RDR: {
705 		if (pf_map_addr(pd->af, r, saddr, naddr, NULL, sn))
706 			goto notrans;
707 		if ((r->rpool.opts & PF_POOL_TYPEMASK) == PF_POOL_BITMASK)
708 			PF_POOLMASK(naddr, naddr, &r->rpool.cur->addr.v.a.mask,
709 			    daddr, pd->af);
710 
711 		if (r->rpool.proxy_port[1]) {
712 			uint32_t	tmp_nport;
713 
714 			tmp_nport = ((ntohs(dport) - ntohs(r->dst.port[0])) %
715 			    (r->rpool.proxy_port[1] - r->rpool.proxy_port[0] +
716 			    1)) + r->rpool.proxy_port[0];
717 
718 			/* Wrap around if necessary. */
719 			if (tmp_nport > 65535)
720 				tmp_nport -= 65535;
721 			*nport = htons((uint16_t)tmp_nport);
722 		} else if (r->rpool.proxy_port[0])
723 			*nport = htons(r->rpool.proxy_port[0]);
724 		break;
725 	}
726 	default:
727 		panic("%s: unknown action %u", __func__, r->action);
728 	}
729 
730 	/* Return success only if translation really happened. */
731 	if (bcmp(*skp, *nkp, sizeof(struct pf_state_key_cmp)))
732 		return (r);
733 
734 notrans:
735 	uma_zfree(V_pf_state_key_z, *nkp);
736 	uma_zfree(V_pf_state_key_z, *skp);
737 	*skp = *nkp = NULL;
738 	*sn = NULL;
739 
740 	return (NULL);
741 }
742