xref: /freebsd/sys/netpfil/pf/pf_lb.c (revision 5bb3134a8c21cb87b30e135ef168483f0333dabb)
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 		pf_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_exists(&key, PF_IN)) {
248 				*nport = sport;
249 				return (0);
250 			}
251 		} else if (low == high) {
252 			key.port[1] = htons(low);
253 			if (!pf_find_state_all_exists(&key, PF_IN)) {
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_exists(&key, PF_IN)) {
272 					*nport = htons(tmp);
273 					return (0);
274 				}
275 			}
276 			tmp = cut;
277 			for (tmp -= 1; tmp >= low && tmp <= 0xffff; --tmp) {
278 				key.port[1] = htons(tmp);
279 				if (!pf_find_state_all_exists(&key, PF_IN)) {
280 					*nport = htons(tmp);
281 					return (0);
282 				}
283 			}
284 		}
285 
286 		switch (r->rpool.opts & PF_POOL_TYPEMASK) {
287 		case PF_POOL_RANDOM:
288 		case PF_POOL_ROUNDROBIN:
289 			/*
290 			 * pick a different source address since we're out
291 			 * of free port choices for the current one.
292 			 */
293 			if (pf_map_addr(af, r, saddr, naddr, &init_addr, sn))
294 				return (1);
295 			break;
296 		case PF_POOL_NONE:
297 		case PF_POOL_SRCHASH:
298 		case PF_POOL_BITMASK:
299 		default:
300 			return (1);
301 		}
302 	} while (! PF_AEQ(&init_addr, naddr, af) );
303 	return (1);					/* none available */
304 }
305 
306 static int
307 pf_get_mape_sport(sa_family_t af, u_int8_t proto, struct pf_krule *r,
308     struct pf_addr *saddr, uint16_t sport, struct pf_addr *daddr,
309     uint16_t dport, struct pf_addr *naddr, uint16_t *nport,
310     struct pf_ksrc_node **sn)
311 {
312 	uint16_t psmask, low, highmask;
313 	uint16_t i, ahigh, cut;
314 	int ashift, psidshift;
315 
316 	ashift = 16 - r->rpool.mape.offset;
317 	psidshift = ashift - r->rpool.mape.psidlen;
318 	psmask = r->rpool.mape.psid & ((1U << r->rpool.mape.psidlen) - 1);
319 	psmask = psmask << psidshift;
320 	highmask = (1U << psidshift) - 1;
321 
322 	ahigh = (1U << r->rpool.mape.offset) - 1;
323 	cut = arc4random() & ahigh;
324 	if (cut == 0)
325 		cut = 1;
326 
327 	for (i = cut; i <= ahigh; i++) {
328 		low = (i << ashift) | psmask;
329 		if (!pf_get_sport(af, proto, r, saddr, sport, daddr, dport,
330 		    naddr, nport, low, low | highmask, sn))
331 			return (0);
332 	}
333 	for (i = cut - 1; i > 0; i--) {
334 		low = (i << ashift) | psmask;
335 		if (!pf_get_sport(af, proto, r, saddr, sport, daddr, dport,
336 		    naddr, nport, low, low | highmask, sn))
337 			return (0);
338 	}
339 	return (1);
340 }
341 
342 int
343 pf_map_addr(sa_family_t af, struct pf_krule *r, struct pf_addr *saddr,
344     struct pf_addr *naddr, struct pf_addr *init_addr, struct pf_ksrc_node **sn)
345 {
346 	struct pf_kpool		*rpool = &r->rpool;
347 	struct pf_addr		*raddr = NULL, *rmask = NULL;
348 
349 	/* Try to find a src_node if none was given and this
350 	   is a sticky-address rule. */
351 	if (*sn == NULL && r->rpool.opts & PF_POOL_STICKYADDR &&
352 	    (r->rpool.opts & PF_POOL_TYPEMASK) != PF_POOL_NONE)
353 		*sn = pf_find_src_node(saddr, r, af, 0);
354 
355 	/* If a src_node was found or explicitly given and it has a non-zero
356 	   route address, use this address. A zeroed address is found if the
357 	   src node was created just a moment ago in pf_create_state and it
358 	   needs to be filled in with routing decision calculated here. */
359 	if (*sn != NULL && !PF_AZERO(&(*sn)->raddr, af)) {
360 		/* If the supplied address is the same as the current one we've
361 		 * been asked before, so tell the caller that there's no other
362 		 * address to be had. */
363 		if (PF_AEQ(naddr, &(*sn)->raddr, af))
364 			return (1);
365 
366 		PF_ACPY(naddr, &(*sn)->raddr, af);
367 		if (V_pf_status.debug >= PF_DEBUG_NOISY) {
368 			printf("pf_map_addr: src tracking maps ");
369 			pf_print_host(saddr, 0, af);
370 			printf(" to ");
371 			pf_print_host(naddr, 0, af);
372 			printf("\n");
373 		}
374 		return (0);
375 	}
376 
377 	/* Find the route using chosen algorithm. Store the found route
378 	   in src_node if it was given or found. */
379 	if (rpool->cur->addr.type == PF_ADDR_NOROUTE)
380 		return (1);
381 	if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
382 		switch (af) {
383 #ifdef INET
384 		case AF_INET:
385 			if (rpool->cur->addr.p.dyn->pfid_acnt4 < 1 &&
386 			    (rpool->opts & PF_POOL_TYPEMASK) !=
387 			    PF_POOL_ROUNDROBIN)
388 				return (1);
389 			 raddr = &rpool->cur->addr.p.dyn->pfid_addr4;
390 			 rmask = &rpool->cur->addr.p.dyn->pfid_mask4;
391 			break;
392 #endif /* INET */
393 #ifdef INET6
394 		case AF_INET6:
395 			if (rpool->cur->addr.p.dyn->pfid_acnt6 < 1 &&
396 			    (rpool->opts & PF_POOL_TYPEMASK) !=
397 			    PF_POOL_ROUNDROBIN)
398 				return (1);
399 			raddr = &rpool->cur->addr.p.dyn->pfid_addr6;
400 			rmask = &rpool->cur->addr.p.dyn->pfid_mask6;
401 			break;
402 #endif /* INET6 */
403 		}
404 	} else if (rpool->cur->addr.type == PF_ADDR_TABLE) {
405 		if ((rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_ROUNDROBIN)
406 			return (1); /* unsupported */
407 	} else {
408 		raddr = &rpool->cur->addr.v.a.addr;
409 		rmask = &rpool->cur->addr.v.a.mask;
410 	}
411 
412 	switch (rpool->opts & PF_POOL_TYPEMASK) {
413 	case PF_POOL_NONE:
414 		PF_ACPY(naddr, raddr, af);
415 		break;
416 	case PF_POOL_BITMASK:
417 		PF_POOLMASK(naddr, raddr, rmask, saddr, af);
418 		break;
419 	case PF_POOL_RANDOM:
420 		if (init_addr != NULL && PF_AZERO(init_addr, af)) {
421 			switch (af) {
422 #ifdef INET
423 			case AF_INET:
424 				rpool->counter.addr32[0] = htonl(arc4random());
425 				break;
426 #endif /* INET */
427 #ifdef INET6
428 			case AF_INET6:
429 				if (rmask->addr32[3] != 0xffffffff)
430 					rpool->counter.addr32[3] =
431 					    htonl(arc4random());
432 				else
433 					break;
434 				if (rmask->addr32[2] != 0xffffffff)
435 					rpool->counter.addr32[2] =
436 					    htonl(arc4random());
437 				else
438 					break;
439 				if (rmask->addr32[1] != 0xffffffff)
440 					rpool->counter.addr32[1] =
441 					    htonl(arc4random());
442 				else
443 					break;
444 				if (rmask->addr32[0] != 0xffffffff)
445 					rpool->counter.addr32[0] =
446 					    htonl(arc4random());
447 				break;
448 #endif /* INET6 */
449 			}
450 			PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
451 			PF_ACPY(init_addr, naddr, af);
452 
453 		} else {
454 			PF_AINC(&rpool->counter, af);
455 			PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
456 		}
457 		break;
458 	case PF_POOL_SRCHASH:
459 	    {
460 		unsigned char hash[16];
461 
462 		pf_hash(saddr, (struct pf_addr *)&hash, &rpool->key, af);
463 		PF_POOLMASK(naddr, raddr, rmask, (struct pf_addr *)&hash, af);
464 		break;
465 	    }
466 	case PF_POOL_ROUNDROBIN:
467 	    {
468 		struct pf_kpooladdr *acur = rpool->cur;
469 
470 		/*
471 		 * XXXGL: in the round-robin case we need to store
472 		 * the round-robin machine state in the rule, thus
473 		 * forwarding thread needs to modify rule.
474 		 *
475 		 * This is done w/o locking, because performance is assumed
476 		 * more important than round-robin precision.
477 		 *
478 		 * In the simpliest case we just update the "rpool->cur"
479 		 * pointer. However, if pool contains tables or dynamic
480 		 * addresses, then "tblidx" is also used to store machine
481 		 * state. Since "tblidx" is int, concurrent access to it can't
482 		 * lead to inconsistence, only to lost of precision.
483 		 *
484 		 * Things get worse, if table contains not hosts, but
485 		 * prefixes. In this case counter also stores machine state,
486 		 * and for IPv6 address, counter can't be updated atomically.
487 		 * Probably, using round-robin on a table containing IPv6
488 		 * prefixes (or even IPv4) would cause a panic.
489 		 */
490 
491 		if (rpool->cur->addr.type == PF_ADDR_TABLE) {
492 			if (!pfr_pool_get(rpool->cur->addr.p.tbl,
493 			    &rpool->tblidx, &rpool->counter, af))
494 				goto get_addr;
495 		} else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
496 			if (!pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
497 			    &rpool->tblidx, &rpool->counter, af))
498 				goto get_addr;
499 		} else if (pf_match_addr(0, raddr, rmask, &rpool->counter, af))
500 			goto get_addr;
501 
502 	try_next:
503 		if (TAILQ_NEXT(rpool->cur, entries) == NULL)
504 			rpool->cur = TAILQ_FIRST(&rpool->list);
505 		else
506 			rpool->cur = TAILQ_NEXT(rpool->cur, entries);
507 		if (rpool->cur->addr.type == PF_ADDR_TABLE) {
508 			rpool->tblidx = -1;
509 			if (pfr_pool_get(rpool->cur->addr.p.tbl,
510 			    &rpool->tblidx, &rpool->counter, af)) {
511 				/* table contains no address of type 'af' */
512 				if (rpool->cur != acur)
513 					goto try_next;
514 				return (1);
515 			}
516 		} else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
517 			rpool->tblidx = -1;
518 			if (pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
519 			    &rpool->tblidx, &rpool->counter, af)) {
520 				/* table contains no address of type 'af' */
521 				if (rpool->cur != acur)
522 					goto try_next;
523 				return (1);
524 			}
525 		} else {
526 			raddr = &rpool->cur->addr.v.a.addr;
527 			rmask = &rpool->cur->addr.v.a.mask;
528 			PF_ACPY(&rpool->counter, raddr, af);
529 		}
530 
531 	get_addr:
532 		PF_ACPY(naddr, &rpool->counter, af);
533 		if (init_addr != NULL && PF_AZERO(init_addr, af))
534 			PF_ACPY(init_addr, naddr, af);
535 		PF_AINC(&rpool->counter, af);
536 		break;
537 	    }
538 	}
539 	if (*sn != NULL)
540 		PF_ACPY(&(*sn)->raddr, naddr, af);
541 
542 	if (V_pf_status.debug >= PF_DEBUG_NOISY &&
543 	    (rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_NONE) {
544 		printf("pf_map_addr: selected address ");
545 		pf_print_host(naddr, 0, af);
546 		printf("\n");
547 	}
548 
549 	return (0);
550 }
551 
552 struct pf_krule *
553 pf_get_translation(struct pf_pdesc *pd, struct mbuf *m, int off, int direction,
554     struct pfi_kkif *kif, struct pf_ksrc_node **sn,
555     struct pf_state_key **skp, struct pf_state_key **nkp,
556     struct pf_addr *saddr, struct pf_addr *daddr,
557     uint16_t sport, uint16_t dport, struct pf_kanchor_stackframe *anchor_stack)
558 {
559 	struct pf_krule	*r = NULL;
560 	struct pf_addr	*naddr;
561 	uint16_t	*nport;
562 	uint16_t	 low, high;
563 
564 	PF_RULES_RASSERT();
565 	KASSERT(*skp == NULL, ("*skp not NULL"));
566 	KASSERT(*nkp == NULL, ("*nkp not NULL"));
567 
568 	if (direction == PF_OUT) {
569 		r = pf_match_translation(pd, m, off, direction, kif, saddr,
570 		    sport, daddr, dport, PF_RULESET_BINAT, anchor_stack);
571 		if (r == NULL)
572 			r = pf_match_translation(pd, m, off, direction, kif,
573 			    saddr, sport, daddr, dport, PF_RULESET_NAT,
574 			    anchor_stack);
575 	} else {
576 		r = pf_match_translation(pd, m, off, direction, kif, saddr,
577 		    sport, daddr, dport, PF_RULESET_RDR, anchor_stack);
578 		if (r == NULL)
579 			r = pf_match_translation(pd, m, off, direction, kif,
580 			    saddr, sport, daddr, dport, PF_RULESET_BINAT,
581 			    anchor_stack);
582 	}
583 
584 	if (r == NULL)
585 		return (NULL);
586 
587 	switch (r->action) {
588 	case PF_NONAT:
589 	case PF_NOBINAT:
590 	case PF_NORDR:
591 		return (NULL);
592 	}
593 
594 	*skp = pf_state_key_setup(pd, saddr, daddr, sport, dport);
595 	if (*skp == NULL)
596 		return (NULL);
597 	*nkp = pf_state_key_clone(*skp);
598 	if (*nkp == NULL) {
599 		uma_zfree(V_pf_state_key_z, *skp);
600 		*skp = NULL;
601 		return (NULL);
602 	}
603 
604 	/* XXX We only modify one side for now. */
605 	naddr = &(*nkp)->addr[1];
606 	nport = &(*nkp)->port[1];
607 
608 	switch (r->action) {
609 	case PF_NAT:
610 		if (pd->proto == IPPROTO_ICMP) {
611 			low  = 1;
612 			high = 65535;
613 		} else {
614 			low  = r->rpool.proxy_port[0];
615 			high = r->rpool.proxy_port[1];
616 		}
617 		if (r->rpool.mape.offset > 0) {
618 			if (pf_get_mape_sport(pd->af, pd->proto, r, saddr,
619 			    sport, daddr, dport, naddr, nport, sn)) {
620 				DPFPRINTF(PF_DEBUG_MISC,
621 				    ("pf: MAP-E port allocation (%u/%u/%u)"
622 				    " failed\n",
623 				    r->rpool.mape.offset,
624 				    r->rpool.mape.psidlen,
625 				    r->rpool.mape.psid));
626 				goto notrans;
627 			}
628 		} else if (pf_get_sport(pd->af, pd->proto, r, saddr, sport,
629 		    daddr, dport, naddr, nport, low, high, sn)) {
630 			DPFPRINTF(PF_DEBUG_MISC,
631 			    ("pf: NAT proxy port allocation (%u-%u) failed\n",
632 			    r->rpool.proxy_port[0], r->rpool.proxy_port[1]));
633 			goto notrans;
634 		}
635 		break;
636 	case PF_BINAT:
637 		switch (direction) {
638 		case PF_OUT:
639 			if (r->rpool.cur->addr.type == PF_ADDR_DYNIFTL){
640 				switch (pd->af) {
641 #ifdef INET
642 				case AF_INET:
643 					if (r->rpool.cur->addr.p.dyn->
644 					    pfid_acnt4 < 1)
645 						goto notrans;
646 					PF_POOLMASK(naddr,
647 					    &r->rpool.cur->addr.p.dyn->
648 					    pfid_addr4,
649 					    &r->rpool.cur->addr.p.dyn->
650 					    pfid_mask4, saddr, AF_INET);
651 					break;
652 #endif /* INET */
653 #ifdef INET6
654 				case AF_INET6:
655 					if (r->rpool.cur->addr.p.dyn->
656 					    pfid_acnt6 < 1)
657 						goto notrans;
658 					PF_POOLMASK(naddr,
659 					    &r->rpool.cur->addr.p.dyn->
660 					    pfid_addr6,
661 					    &r->rpool.cur->addr.p.dyn->
662 					    pfid_mask6, saddr, AF_INET6);
663 					break;
664 #endif /* INET6 */
665 				}
666 			} else
667 				PF_POOLMASK(naddr,
668 				    &r->rpool.cur->addr.v.a.addr,
669 				    &r->rpool.cur->addr.v.a.mask, saddr,
670 				    pd->af);
671 			break;
672 		case PF_IN:
673 			if (r->src.addr.type == PF_ADDR_DYNIFTL) {
674 				switch (pd->af) {
675 #ifdef INET
676 				case AF_INET:
677 					if (r->src.addr.p.dyn-> pfid_acnt4 < 1)
678 						goto notrans;
679 					PF_POOLMASK(naddr,
680 					    &r->src.addr.p.dyn->pfid_addr4,
681 					    &r->src.addr.p.dyn->pfid_mask4,
682 					    daddr, AF_INET);
683 					break;
684 #endif /* INET */
685 #ifdef INET6
686 				case AF_INET6:
687 					if (r->src.addr.p.dyn->pfid_acnt6 < 1)
688 						goto notrans;
689 					PF_POOLMASK(naddr,
690 					    &r->src.addr.p.dyn->pfid_addr6,
691 					    &r->src.addr.p.dyn->pfid_mask6,
692 					    daddr, AF_INET6);
693 					break;
694 #endif /* INET6 */
695 				}
696 			} else
697 				PF_POOLMASK(naddr, &r->src.addr.v.a.addr,
698 				    &r->src.addr.v.a.mask, daddr, pd->af);
699 			break;
700 		}
701 		break;
702 	case PF_RDR: {
703 		if (pf_map_addr(pd->af, r, saddr, naddr, NULL, sn))
704 			goto notrans;
705 		if ((r->rpool.opts & PF_POOL_TYPEMASK) == PF_POOL_BITMASK)
706 			PF_POOLMASK(naddr, naddr, &r->rpool.cur->addr.v.a.mask,
707 			    daddr, pd->af);
708 
709 		if (r->rpool.proxy_port[1]) {
710 			uint32_t	tmp_nport;
711 
712 			tmp_nport = ((ntohs(dport) - ntohs(r->dst.port[0])) %
713 			    (r->rpool.proxy_port[1] - r->rpool.proxy_port[0] +
714 			    1)) + r->rpool.proxy_port[0];
715 
716 			/* Wrap around if necessary. */
717 			if (tmp_nport > 65535)
718 				tmp_nport -= 65535;
719 			*nport = htons((uint16_t)tmp_nport);
720 		} else if (r->rpool.proxy_port[0])
721 			*nport = htons(r->rpool.proxy_port[0]);
722 		break;
723 	}
724 	default:
725 		panic("%s: unknown action %u", __func__, r->action);
726 	}
727 
728 	/* Return success only if translation really happened. */
729 	if (bcmp(*skp, *nkp, sizeof(struct pf_state_key_cmp)))
730 		return (r);
731 
732 notrans:
733 	uma_zfree(V_pf_state_key_z, *nkp);
734 	uma_zfree(V_pf_state_key_z, *skp);
735 	*skp = *nkp = NULL;
736 	*sn = NULL;
737 
738 	return (NULL);
739 }
740