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 #include "opt_pf.h"
41 #include "opt_inet.h"
42 #include "opt_inet6.h"
43
44 #include <sys/param.h>
45 #include <sys/lock.h>
46 #include <sys/mbuf.h>
47 #include <sys/socket.h>
48 #include <sys/sysctl.h>
49
50 #include <net/if.h>
51 #include <net/vnet.h>
52 #include <net/pfvar.h>
53 #include <net/if_pflog.h>
54
55 /*
56 * Limit the amount of work we do to find a free source port for redirects that
57 * introduce a state conflict.
58 */
59 #define V_pf_rdr_srcport_rewrite_tries VNET(pf_rdr_srcport_rewrite_tries)
60 VNET_DEFINE_STATIC(int, pf_rdr_srcport_rewrite_tries) = 16;
61
62 #define DPFPRINTF(n, x) if (V_pf_status.debug >= (n)) printf x
63
64 static void pf_hash(struct pf_addr *, struct pf_addr *,
65 struct pf_poolhashkey *, sa_family_t);
66 static struct pf_krule *pf_match_translation(struct pf_pdesc *,
67 struct pf_addr *, u_int16_t,
68 struct pf_addr *, uint16_t, int,
69 struct pf_kanchor_stackframe *);
70 static int pf_get_sport(sa_family_t, uint8_t, struct pf_krule *,
71 struct pf_addr *, uint16_t, struct pf_addr *, uint16_t, struct pf_addr *,
72 uint16_t *, uint16_t, uint16_t, struct pf_ksrc_node **, struct pf_srchash**,
73 struct pf_udp_mapping **);
74 static bool pf_islinklocal(const sa_family_t, const struct pf_addr *);
75
76 #define mix(a,b,c) \
77 do { \
78 a -= b; a -= c; a ^= (c >> 13); \
79 b -= c; b -= a; b ^= (a << 8); \
80 c -= a; c -= b; c ^= (b >> 13); \
81 a -= b; a -= c; a ^= (c >> 12); \
82 b -= c; b -= a; b ^= (a << 16); \
83 c -= a; c -= b; c ^= (b >> 5); \
84 a -= b; a -= c; a ^= (c >> 3); \
85 b -= c; b -= a; b ^= (a << 10); \
86 c -= a; c -= b; c ^= (b >> 15); \
87 } while (0)
88
89 /*
90 * hash function based on bridge_hash in if_bridge.c
91 */
92 static void
pf_hash(struct pf_addr * inaddr,struct pf_addr * hash,struct pf_poolhashkey * key,sa_family_t af)93 pf_hash(struct pf_addr *inaddr, struct pf_addr *hash,
94 struct pf_poolhashkey *key, sa_family_t af)
95 {
96 u_int32_t a = 0x9e3779b9, b = 0x9e3779b9, c = key->key32[0];
97
98 switch (af) {
99 #ifdef INET
100 case AF_INET:
101 a += inaddr->addr32[0];
102 b += key->key32[1];
103 mix(a, b, c);
104 hash->addr32[0] = c + key->key32[2];
105 break;
106 #endif /* INET */
107 #ifdef INET6
108 case AF_INET6:
109 a += inaddr->addr32[0];
110 b += inaddr->addr32[2];
111 mix(a, b, c);
112 hash->addr32[0] = c;
113 a += inaddr->addr32[1];
114 b += inaddr->addr32[3];
115 c += key->key32[1];
116 mix(a, b, c);
117 hash->addr32[1] = c;
118 a += inaddr->addr32[2];
119 b += inaddr->addr32[1];
120 c += key->key32[2];
121 mix(a, b, c);
122 hash->addr32[2] = c;
123 a += inaddr->addr32[3];
124 b += inaddr->addr32[0];
125 c += key->key32[3];
126 mix(a, b, c);
127 hash->addr32[3] = c;
128 break;
129 #endif /* INET6 */
130 }
131 }
132
133 static struct pf_krule *
pf_match_translation(struct pf_pdesc * pd,struct pf_addr * saddr,u_int16_t sport,struct pf_addr * daddr,uint16_t dport,int rs_num,struct pf_kanchor_stackframe * anchor_stack)134 pf_match_translation(struct pf_pdesc *pd,
135 struct pf_addr *saddr, u_int16_t sport,
136 struct pf_addr *daddr, uint16_t dport, int rs_num,
137 struct pf_kanchor_stackframe *anchor_stack)
138 {
139 struct pf_krule *r, *rm = NULL;
140 struct pf_kruleset *ruleset = NULL;
141 int tag = -1;
142 int rtableid = -1;
143 int asd = 0;
144
145 r = TAILQ_FIRST(pf_main_ruleset.rules[rs_num].active.ptr);
146 while (r != NULL) {
147 struct pf_rule_addr *src = NULL, *dst = NULL;
148 struct pf_addr_wrap *xdst = NULL;
149
150 if (r->action == PF_BINAT && pd->dir == PF_IN) {
151 src = &r->dst;
152 if (r->rpool.cur != NULL)
153 xdst = &r->rpool.cur->addr;
154 } else {
155 src = &r->src;
156 dst = &r->dst;
157 }
158
159 pf_counter_u64_add(&r->evaluations, 1);
160 if (pfi_kkif_match(r->kif, pd->kif) == r->ifnot)
161 r = r->skip[PF_SKIP_IFP];
162 else if (r->direction && r->direction != pd->dir)
163 r = r->skip[PF_SKIP_DIR];
164 else if (r->af && r->af != pd->af)
165 r = r->skip[PF_SKIP_AF];
166 else if (r->proto && r->proto != pd->proto)
167 r = r->skip[PF_SKIP_PROTO];
168 else if (PF_MISMATCHAW(&src->addr, saddr, pd->af,
169 src->neg, pd->kif, M_GETFIB(pd->m)))
170 r = r->skip[src == &r->src ? PF_SKIP_SRC_ADDR :
171 PF_SKIP_DST_ADDR];
172 else if (src->port_op && !pf_match_port(src->port_op,
173 src->port[0], src->port[1], sport))
174 r = r->skip[src == &r->src ? PF_SKIP_SRC_PORT :
175 PF_SKIP_DST_PORT];
176 else if (dst != NULL &&
177 PF_MISMATCHAW(&dst->addr, daddr, pd->af, dst->neg, NULL,
178 M_GETFIB(pd->m)))
179 r = r->skip[PF_SKIP_DST_ADDR];
180 else if (xdst != NULL && PF_MISMATCHAW(xdst, daddr, pd->af,
181 0, NULL, M_GETFIB(pd->m)))
182 r = TAILQ_NEXT(r, entries);
183 else if (dst != NULL && dst->port_op &&
184 !pf_match_port(dst->port_op, dst->port[0],
185 dst->port[1], dport))
186 r = r->skip[PF_SKIP_DST_PORT];
187 else if (r->match_tag && !pf_match_tag(pd->m, r, &tag,
188 pd->pf_mtag ? pd->pf_mtag->tag : 0))
189 r = TAILQ_NEXT(r, entries);
190 else if (r->os_fingerprint != PF_OSFP_ANY && (pd->proto !=
191 IPPROTO_TCP || !pf_osfp_match(pf_osfp_fingerprint(pd,
192 &pd->hdr.tcp), r->os_fingerprint)))
193 r = TAILQ_NEXT(r, entries);
194 else {
195 if (r->tag)
196 tag = r->tag;
197 if (r->rtableid >= 0)
198 rtableid = r->rtableid;
199 if (r->anchor == NULL) {
200 rm = r;
201 if (rm->action == PF_NONAT ||
202 rm->action == PF_NORDR ||
203 rm->action == PF_NOBINAT) {
204 rm = NULL;
205 }
206 break;
207 } else
208 pf_step_into_anchor(anchor_stack, &asd,
209 &ruleset, rs_num, &r, NULL, NULL);
210 }
211 if (r == NULL)
212 pf_step_out_of_anchor(anchor_stack, &asd, &ruleset,
213 rs_num, &r, NULL, NULL);
214 }
215
216 if (tag > 0 && pf_tag_packet(pd, tag))
217 return (NULL);
218 if (rtableid >= 0)
219 M_SETFIB(pd->m, rtableid);
220
221 return (rm);
222 }
223
224 static int
pf_get_sport(sa_family_t af,u_int8_t proto,struct pf_krule * r,struct pf_addr * saddr,uint16_t sport,struct pf_addr * daddr,uint16_t dport,struct pf_addr * naddr,uint16_t * nport,uint16_t low,uint16_t high,struct pf_ksrc_node ** sn,struct pf_srchash ** sh,struct pf_udp_mapping ** udp_mapping)225 pf_get_sport(sa_family_t af, u_int8_t proto, struct pf_krule *r,
226 struct pf_addr *saddr, uint16_t sport, struct pf_addr *daddr,
227 uint16_t dport, struct pf_addr *naddr, uint16_t *nport, uint16_t low,
228 uint16_t high, struct pf_ksrc_node **sn, struct pf_srchash **sh,
229 struct pf_udp_mapping **udp_mapping)
230 {
231 struct pf_state_key_cmp key;
232 struct pf_addr init_addr;
233
234 bzero(&init_addr, sizeof(init_addr));
235
236 MPASS(*udp_mapping == NULL);
237
238 /*
239 * If we are UDP and have an existing mapping we can get source port
240 * from the mapping. In this case we have to look up the src_node as
241 * pf_map_addr would.
242 */
243 if (proto == IPPROTO_UDP && (r->rpool.opts & PF_POOL_ENDPI)) {
244 struct pf_udp_endpoint_cmp udp_source;
245
246 bzero(&udp_source, sizeof(udp_source));
247 udp_source.af = af;
248 PF_ACPY(&udp_source.addr, saddr, af);
249 udp_source.port = sport;
250 *udp_mapping = pf_udp_mapping_find(&udp_source);
251 if (*udp_mapping) {
252 PF_ACPY(naddr, &(*udp_mapping)->endpoints[1].addr, af);
253 *nport = (*udp_mapping)->endpoints[1].port;
254 /* Try to find a src_node as per pf_map_addr(). */
255 if (*sn == NULL && r->rpool.opts & PF_POOL_STICKYADDR &&
256 (r->rpool.opts & PF_POOL_TYPEMASK) != PF_POOL_NONE)
257 *sn = pf_find_src_node(saddr, r, af, sh, false);
258 if (*sn != NULL)
259 PF_SRC_NODE_UNLOCK(*sn);
260 return (0);
261 } else {
262 *udp_mapping = pf_udp_mapping_create(af, saddr, sport, &init_addr, 0);
263 if (*udp_mapping == NULL)
264 return (1);
265 }
266 }
267
268 if (pf_map_addr_sn(af, r, saddr, naddr, NULL, &init_addr, sn, sh))
269 goto failed;
270
271 if (proto == IPPROTO_ICMP) {
272 if (*nport == htons(ICMP_ECHO)) {
273 low = 1;
274 high = 65535;
275 } else
276 return (0); /* Don't try to modify non-echo ICMP */
277 }
278 #ifdef INET6
279 if (proto == IPPROTO_ICMPV6) {
280 if (*nport == htons(ICMP6_ECHO_REQUEST)) {
281 low = 1;
282 high = 65535;
283 } else
284 return (0); /* Don't try to modify non-echo ICMP */
285 }
286 #endif /* INET6 */
287
288 bzero(&key, sizeof(key));
289 key.af = af;
290 key.proto = proto;
291 key.port[0] = dport;
292 PF_ACPY(&key.addr[0], daddr, key.af);
293
294 do {
295 PF_ACPY(&key.addr[1], naddr, key.af);
296 if (*udp_mapping)
297 PF_ACPY(&(*udp_mapping)->endpoints[1].addr, naddr, af);
298
299 /*
300 * port search; start random, step;
301 * similar 2 portloop in in_pcbbind
302 */
303 if (proto == IPPROTO_SCTP) {
304 key.port[1] = sport;
305 if (!pf_find_state_all_exists(&key, PF_IN)) {
306 *nport = sport;
307 return (0);
308 } else {
309 return (1); /* Fail mapping. */
310 }
311 } else if (!(proto == IPPROTO_TCP || proto == IPPROTO_UDP ||
312 proto == IPPROTO_ICMP) || (low == 0 && high == 0)) {
313 /*
314 * XXX bug: icmp states don't use the id on both sides.
315 * (traceroute -I through nat)
316 */
317 key.port[1] = sport;
318 if (!pf_find_state_all_exists(&key, PF_IN)) {
319 *nport = sport;
320 return (0);
321 }
322 } else if (low == high) {
323 key.port[1] = htons(low);
324 if (!pf_find_state_all_exists(&key, PF_IN)) {
325 if (*udp_mapping != NULL) {
326 (*udp_mapping)->endpoints[1].port = htons(low);
327 if (pf_udp_mapping_insert(*udp_mapping) == 0) {
328 *nport = htons(low);
329 return (0);
330 }
331 } else {
332 *nport = htons(low);
333 return (0);
334 }
335 }
336 } else {
337 uint32_t tmp;
338 uint16_t cut;
339
340 if (low > high) {
341 tmp = low;
342 low = high;
343 high = tmp;
344 }
345 /* low < high */
346 cut = arc4random() % (1 + high - low) + low;
347 /* low <= cut <= high */
348 for (tmp = cut; tmp <= high && tmp <= 0xffff; ++tmp) {
349 if (*udp_mapping != NULL) {
350 (*udp_mapping)->endpoints[1].port = htons(tmp);
351 if (pf_udp_mapping_insert(*udp_mapping) == 0) {
352 *nport = htons(tmp);
353 return (0);
354 }
355 } else {
356 key.port[1] = htons(tmp);
357 if (!pf_find_state_all_exists(&key, PF_IN)) {
358 *nport = htons(tmp);
359 return (0);
360 }
361 }
362 }
363 tmp = cut;
364 for (tmp -= 1; tmp >= low && tmp <= 0xffff; --tmp) {
365 if (proto == IPPROTO_UDP &&
366 (r->rpool.opts & PF_POOL_ENDPI)) {
367 (*udp_mapping)->endpoints[1].port = htons(tmp);
368 if (pf_udp_mapping_insert(*udp_mapping) == 0) {
369 *nport = htons(tmp);
370 return (0);
371 }
372 } else {
373 key.port[1] = htons(tmp);
374 if (!pf_find_state_all_exists(&key, PF_IN)) {
375 *nport = htons(tmp);
376 return (0);
377 }
378 }
379 }
380 }
381
382 switch (r->rpool.opts & PF_POOL_TYPEMASK) {
383 case PF_POOL_RANDOM:
384 case PF_POOL_ROUNDROBIN:
385 /*
386 * pick a different source address since we're out
387 * of free port choices for the current one.
388 */
389 (*sn) = NULL;
390 if (pf_map_addr_sn(af, r, saddr, naddr, NULL, &init_addr, sn, sh))
391 return (1);
392 break;
393 case PF_POOL_NONE:
394 case PF_POOL_SRCHASH:
395 case PF_POOL_BITMASK:
396 default:
397 return (1);
398 }
399 } while (! PF_AEQ(&init_addr, naddr, af) );
400
401 failed:
402 uma_zfree(V_pf_udp_mapping_z, *udp_mapping);
403 *udp_mapping = NULL;
404 return (1); /* none available */
405 }
406
407 static bool
pf_islinklocal(const sa_family_t af,const struct pf_addr * addr)408 pf_islinklocal(const sa_family_t af, const struct pf_addr *addr)
409 {
410 if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL(&addr->v6))
411 return (true);
412 return (false);
413 }
414
415 static int
pf_get_mape_sport(sa_family_t af,u_int8_t proto,struct pf_krule * r,struct pf_addr * saddr,uint16_t sport,struct pf_addr * daddr,uint16_t dport,struct pf_addr * naddr,uint16_t * nport,struct pf_ksrc_node ** sn,struct pf_srchash ** sh,struct pf_udp_mapping ** udp_mapping)416 pf_get_mape_sport(sa_family_t af, u_int8_t proto, struct pf_krule *r,
417 struct pf_addr *saddr, uint16_t sport, struct pf_addr *daddr,
418 uint16_t dport, struct pf_addr *naddr, uint16_t *nport,
419 struct pf_ksrc_node **sn, struct pf_srchash **sh,
420 struct pf_udp_mapping **udp_mapping)
421 {
422 uint16_t psmask, low, highmask;
423 uint16_t i, ahigh, cut;
424 int ashift, psidshift;
425
426 ashift = 16 - r->rpool.mape.offset;
427 psidshift = ashift - r->rpool.mape.psidlen;
428 psmask = r->rpool.mape.psid & ((1U << r->rpool.mape.psidlen) - 1);
429 psmask = psmask << psidshift;
430 highmask = (1U << psidshift) - 1;
431
432 ahigh = (1U << r->rpool.mape.offset) - 1;
433 cut = arc4random() & ahigh;
434 if (cut == 0)
435 cut = 1;
436
437 for (i = cut; i <= ahigh; i++) {
438 low = (i << ashift) | psmask;
439 if (!pf_get_sport(af, proto, r, saddr, sport, daddr, dport,
440 naddr, nport, low, low | highmask, sn, sh, udp_mapping))
441 return (0);
442 }
443 for (i = cut - 1; i > 0; i--) {
444 low = (i << ashift) | psmask;
445 if (!pf_get_sport(af, proto, r, saddr, sport, daddr, dport,
446 naddr, nport, low, low | highmask, sn, sh, udp_mapping))
447 return (0);
448 }
449 return (1);
450 }
451
452 u_short
pf_map_addr(sa_family_t af,struct pf_krule * r,struct pf_addr * saddr,struct pf_addr * naddr,struct pfi_kkif ** nkif,struct pf_addr * init_addr)453 pf_map_addr(sa_family_t af, struct pf_krule *r, struct pf_addr *saddr,
454 struct pf_addr *naddr, struct pfi_kkif **nkif, struct pf_addr *init_addr)
455 {
456 u_short reason = PFRES_MATCH;
457 struct pf_kpool *rpool = &r->rpool;
458 struct pf_addr *raddr = NULL, *rmask = NULL;
459
460 mtx_lock(&rpool->mtx);
461 /* Find the route using chosen algorithm. Store the found route
462 in src_node if it was given or found. */
463 if (rpool->cur->addr.type == PF_ADDR_NOROUTE) {
464 reason = PFRES_MAPFAILED;
465 goto done_pool_mtx;
466 }
467 if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
468 switch (af) {
469 #ifdef INET
470 case AF_INET:
471 if (rpool->cur->addr.p.dyn->pfid_acnt4 < 1 &&
472 (rpool->opts & PF_POOL_TYPEMASK) !=
473 PF_POOL_ROUNDROBIN) {
474 reason = PFRES_MAPFAILED;
475 goto done_pool_mtx;
476 }
477 raddr = &rpool->cur->addr.p.dyn->pfid_addr4;
478 rmask = &rpool->cur->addr.p.dyn->pfid_mask4;
479 break;
480 #endif /* INET */
481 #ifdef INET6
482 case AF_INET6:
483 if (rpool->cur->addr.p.dyn->pfid_acnt6 < 1 &&
484 (rpool->opts & PF_POOL_TYPEMASK) !=
485 PF_POOL_ROUNDROBIN) {
486 reason = PFRES_MAPFAILED;
487 goto done_pool_mtx;
488 }
489 raddr = &rpool->cur->addr.p.dyn->pfid_addr6;
490 rmask = &rpool->cur->addr.p.dyn->pfid_mask6;
491 break;
492 #endif /* INET6 */
493 }
494 } else if (rpool->cur->addr.type == PF_ADDR_TABLE) {
495 if ((rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_ROUNDROBIN) {
496 reason = PFRES_MAPFAILED;
497 goto done_pool_mtx; /* unsupported */
498 }
499 } else {
500 raddr = &rpool->cur->addr.v.a.addr;
501 rmask = &rpool->cur->addr.v.a.mask;
502 }
503
504 switch (rpool->opts & PF_POOL_TYPEMASK) {
505 case PF_POOL_NONE:
506 PF_ACPY(naddr, raddr, af);
507 break;
508 case PF_POOL_BITMASK:
509 PF_POOLMASK(naddr, raddr, rmask, saddr, af);
510 break;
511 case PF_POOL_RANDOM:
512 if (init_addr != NULL && PF_AZERO(init_addr, af)) {
513 switch (af) {
514 #ifdef INET
515 case AF_INET:
516 rpool->counter.addr32[0] = htonl(arc4random());
517 break;
518 #endif /* INET */
519 #ifdef INET6
520 case AF_INET6:
521 if (rmask->addr32[3] != 0xffffffff)
522 rpool->counter.addr32[3] =
523 htonl(arc4random());
524 else
525 break;
526 if (rmask->addr32[2] != 0xffffffff)
527 rpool->counter.addr32[2] =
528 htonl(arc4random());
529 else
530 break;
531 if (rmask->addr32[1] != 0xffffffff)
532 rpool->counter.addr32[1] =
533 htonl(arc4random());
534 else
535 break;
536 if (rmask->addr32[0] != 0xffffffff)
537 rpool->counter.addr32[0] =
538 htonl(arc4random());
539 break;
540 #endif /* INET6 */
541 }
542 PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
543 PF_ACPY(init_addr, naddr, af);
544
545 } else {
546 PF_AINC(&rpool->counter, af);
547 PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
548 }
549 break;
550 case PF_POOL_SRCHASH:
551 {
552 unsigned char hash[16];
553
554 pf_hash(saddr, (struct pf_addr *)&hash, &rpool->key, af);
555 PF_POOLMASK(naddr, raddr, rmask, (struct pf_addr *)&hash, af);
556 break;
557 }
558 case PF_POOL_ROUNDROBIN:
559 {
560 struct pf_kpooladdr *acur = rpool->cur;
561
562 if (rpool->cur->addr.type == PF_ADDR_TABLE) {
563 if (!pfr_pool_get(rpool->cur->addr.p.tbl,
564 &rpool->tblidx, &rpool->counter, af, NULL))
565 goto get_addr;
566 } else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
567 if (!pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
568 &rpool->tblidx, &rpool->counter, af, pf_islinklocal))
569 goto get_addr;
570 } else if (pf_match_addr(0, raddr, rmask, &rpool->counter, af))
571 goto get_addr;
572
573 try_next:
574 if (TAILQ_NEXT(rpool->cur, entries) == NULL)
575 rpool->cur = TAILQ_FIRST(&rpool->list);
576 else
577 rpool->cur = TAILQ_NEXT(rpool->cur, entries);
578 if (rpool->cur->addr.type == PF_ADDR_TABLE) {
579 rpool->tblidx = -1;
580 if (pfr_pool_get(rpool->cur->addr.p.tbl,
581 &rpool->tblidx, &rpool->counter, af, NULL)) {
582 /* table contains no address of type 'af' */
583 if (rpool->cur != acur)
584 goto try_next;
585 reason = PFRES_MAPFAILED;
586 goto done_pool_mtx;
587 }
588 } else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
589 rpool->tblidx = -1;
590 if (pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
591 &rpool->tblidx, &rpool->counter, af, pf_islinklocal)) {
592 /* table contains no address of type 'af' */
593 if (rpool->cur != acur)
594 goto try_next;
595 reason = PFRES_MAPFAILED;
596 goto done_pool_mtx;
597 }
598 } else {
599 raddr = &rpool->cur->addr.v.a.addr;
600 rmask = &rpool->cur->addr.v.a.mask;
601 PF_ACPY(&rpool->counter, raddr, af);
602 }
603
604 get_addr:
605 PF_ACPY(naddr, &rpool->counter, af);
606 if (init_addr != NULL && PF_AZERO(init_addr, af))
607 PF_ACPY(init_addr, naddr, af);
608 PF_AINC(&rpool->counter, af);
609 break;
610 }
611 }
612
613 if (nkif)
614 *nkif = rpool->cur->kif;
615
616 done_pool_mtx:
617 mtx_unlock(&rpool->mtx);
618
619 if (reason) {
620 counter_u64_add(V_pf_status.counters[reason], 1);
621 }
622
623 return (reason);
624 }
625
626 u_short
pf_map_addr_sn(sa_family_t af,struct pf_krule * r,struct pf_addr * saddr,struct pf_addr * naddr,struct pfi_kkif ** nkif,struct pf_addr * init_addr,struct pf_ksrc_node ** sn,struct pf_srchash ** sh)627 pf_map_addr_sn(sa_family_t af, struct pf_krule *r, struct pf_addr *saddr,
628 struct pf_addr *naddr, struct pfi_kkif **nkif, struct pf_addr *init_addr,
629 struct pf_ksrc_node **sn, struct pf_srchash **sh)
630 {
631 u_short reason = 0;
632 struct pf_kpool *rpool = &r->rpool;
633
634 KASSERT(*sn == NULL, ("*sn not NULL"));
635
636 /*
637 * If this is a sticky-address rule, try to find an existing src_node.
638 * Request the sh to be unlocked if sn was not found, as we never
639 * insert a new sn when parsing the ruleset.
640 */
641 if (r->rpool.opts & PF_POOL_STICKYADDR &&
642 (r->rpool.opts & PF_POOL_TYPEMASK) != PF_POOL_NONE)
643 *sn = pf_find_src_node(saddr, r, af, sh, false);
644
645 if (*sn != NULL) {
646 PF_SRC_NODE_LOCK_ASSERT(*sn);
647
648 /* If the supplied address is the same as the current one we've
649 * been asked before, so tell the caller that there's no other
650 * address to be had. */
651 if (PF_AEQ(naddr, &(*sn)->raddr, af)) {
652 reason = PFRES_MAPFAILED;
653 goto done;
654 }
655
656 PF_ACPY(naddr, &(*sn)->raddr, af);
657 if (nkif)
658 *nkif = (*sn)->rkif;
659 if (V_pf_status.debug >= PF_DEBUG_NOISY) {
660 printf("pf_map_addr: src tracking maps ");
661 pf_print_host(saddr, 0, af);
662 printf(" to ");
663 pf_print_host(naddr, 0, af);
664 if (nkif)
665 printf("@%s", (*nkif)->pfik_name);
666 printf("\n");
667 }
668 goto done;
669 }
670
671 /*
672 * Source node has not been found. Find a new address and store it
673 * in variables given by the caller.
674 */
675 if (pf_map_addr(af, r, saddr, naddr, nkif, init_addr) != 0) {
676 /* pf_map_addr() sets reason counters on its own */
677 goto done;
678 }
679
680 if (V_pf_status.debug >= PF_DEBUG_NOISY &&
681 (rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_NONE) {
682 printf("pf_map_addr: selected address ");
683 pf_print_host(naddr, 0, af);
684 if (nkif)
685 printf("@%s", (*nkif)->pfik_name);
686 printf("\n");
687 }
688
689 done:
690 if ((*sn) != NULL)
691 PF_SRC_NODE_UNLOCK(*sn);
692
693 if (reason) {
694 counter_u64_add(V_pf_status.counters[reason], 1);
695 }
696
697 return (reason);
698 }
699
700 u_short
pf_get_translation(struct pf_pdesc * pd,int off,struct pf_state_key ** skp,struct pf_state_key ** nkp,struct pf_addr * saddr,struct pf_addr * daddr,uint16_t sport,uint16_t dport,struct pf_kanchor_stackframe * anchor_stack,struct pf_krule ** rp,struct pf_udp_mapping ** udp_mapping)701 pf_get_translation(struct pf_pdesc *pd, int off,
702 struct pf_state_key **skp, struct pf_state_key **nkp, struct pf_addr *saddr,
703 struct pf_addr *daddr, uint16_t sport, uint16_t dport,
704 struct pf_kanchor_stackframe *anchor_stack, struct pf_krule **rp,
705 struct pf_udp_mapping **udp_mapping)
706 {
707 struct pf_krule *r = NULL;
708 struct pf_addr *naddr;
709 struct pf_ksrc_node *sn = NULL;
710 struct pf_srchash *sh = NULL;
711 uint16_t *nportp;
712 uint16_t low, high;
713 u_short reason;
714
715 PF_RULES_RASSERT();
716 KASSERT(*skp == NULL, ("*skp not NULL"));
717 KASSERT(*nkp == NULL, ("*nkp not NULL"));
718
719 *rp = NULL;
720
721 if (pd->dir == PF_OUT) {
722 r = pf_match_translation(pd, saddr,
723 sport, daddr, dport, PF_RULESET_BINAT, anchor_stack);
724 if (r == NULL)
725 r = pf_match_translation(pd,
726 saddr, sport, daddr, dport, PF_RULESET_NAT,
727 anchor_stack);
728 } else {
729 r = pf_match_translation(pd, saddr,
730 sport, daddr, dport, PF_RULESET_RDR, anchor_stack);
731 if (r == NULL)
732 r = pf_match_translation(pd,
733 saddr, sport, daddr, dport, PF_RULESET_BINAT,
734 anchor_stack);
735 }
736
737 if (r == NULL)
738 return (PFRES_MAX);
739
740 switch (r->action) {
741 case PF_NONAT:
742 case PF_NOBINAT:
743 case PF_NORDR:
744 return (PFRES_MAX);
745 }
746
747 *skp = pf_state_key_setup(pd, saddr, daddr, sport, dport);
748 if (*skp == NULL)
749 return (PFRES_MEMORY);
750 *nkp = pf_state_key_clone(*skp);
751 if (*nkp == NULL) {
752 uma_zfree(V_pf_state_key_z, *skp);
753 *skp = NULL;
754 return (PFRES_MEMORY);
755 }
756
757 naddr = &(*nkp)->addr[1];
758 nportp = &(*nkp)->port[1];
759
760 switch (r->action) {
761 case PF_NAT:
762 if (pd->proto == IPPROTO_ICMP) {
763 low = 1;
764 high = 65535;
765 } else {
766 low = r->rpool.proxy_port[0];
767 high = r->rpool.proxy_port[1];
768 }
769 if (r->rpool.mape.offset > 0) {
770 if (pf_get_mape_sport(pd->af, pd->proto, r, saddr,
771 sport, daddr, dport, naddr, nportp, &sn, &sh,
772 udp_mapping)) {
773 DPFPRINTF(PF_DEBUG_MISC,
774 ("pf: MAP-E port allocation (%u/%u/%u)"
775 " failed\n",
776 r->rpool.mape.offset,
777 r->rpool.mape.psidlen,
778 r->rpool.mape.psid));
779 reason = PFRES_MAPFAILED;
780 goto notrans;
781 }
782 } else if (pf_get_sport(pd->af, pd->proto, r, saddr, sport,
783 daddr, dport, naddr, nportp, low, high, &sn, &sh,
784 udp_mapping)) {
785 DPFPRINTF(PF_DEBUG_MISC,
786 ("pf: NAT proxy port allocation (%u-%u) failed\n",
787 r->rpool.proxy_port[0], r->rpool.proxy_port[1]));
788 reason = PFRES_MAPFAILED;
789 goto notrans;
790 }
791 break;
792 case PF_BINAT:
793 switch (pd->dir) {
794 case PF_OUT:
795 if (r->rpool.cur->addr.type == PF_ADDR_DYNIFTL){
796 switch (pd->af) {
797 #ifdef INET
798 case AF_INET:
799 if (r->rpool.cur->addr.p.dyn->
800 pfid_acnt4 < 1) {
801 reason = PFRES_MAPFAILED;
802 goto notrans;
803 }
804 PF_POOLMASK(naddr,
805 &r->rpool.cur->addr.p.dyn->
806 pfid_addr4,
807 &r->rpool.cur->addr.p.dyn->
808 pfid_mask4, saddr, AF_INET);
809 break;
810 #endif /* INET */
811 #ifdef INET6
812 case AF_INET6:
813 if (r->rpool.cur->addr.p.dyn->
814 pfid_acnt6 < 1) {
815 reason = PFRES_MAPFAILED;
816 goto notrans;
817 }
818 PF_POOLMASK(naddr,
819 &r->rpool.cur->addr.p.dyn->
820 pfid_addr6,
821 &r->rpool.cur->addr.p.dyn->
822 pfid_mask6, saddr, AF_INET6);
823 break;
824 #endif /* INET6 */
825 }
826 } else
827 PF_POOLMASK(naddr,
828 &r->rpool.cur->addr.v.a.addr,
829 &r->rpool.cur->addr.v.a.mask, saddr,
830 pd->af);
831 break;
832 case PF_IN:
833 if (r->src.addr.type == PF_ADDR_DYNIFTL) {
834 switch (pd->af) {
835 #ifdef INET
836 case AF_INET:
837 if (r->src.addr.p.dyn->pfid_acnt4 < 1) {
838 reason = PFRES_MAPFAILED;
839 goto notrans;
840 }
841 PF_POOLMASK(naddr,
842 &r->src.addr.p.dyn->pfid_addr4,
843 &r->src.addr.p.dyn->pfid_mask4,
844 daddr, AF_INET);
845 break;
846 #endif /* INET */
847 #ifdef INET6
848 case AF_INET6:
849 if (r->src.addr.p.dyn->pfid_acnt6 < 1) {
850 reason = PFRES_MAPFAILED;
851 goto notrans;
852 }
853 PF_POOLMASK(naddr,
854 &r->src.addr.p.dyn->pfid_addr6,
855 &r->src.addr.p.dyn->pfid_mask6,
856 daddr, AF_INET6);
857 break;
858 #endif /* INET6 */
859 }
860 } else
861 PF_POOLMASK(naddr, &r->src.addr.v.a.addr,
862 &r->src.addr.v.a.mask, daddr, pd->af);
863 break;
864 }
865 break;
866 case PF_RDR: {
867 struct pf_state_key_cmp key;
868 int tries;
869 uint16_t cut, low, high, nport;
870
871 reason = pf_map_addr_sn(pd->af, r, saddr, naddr, NULL, NULL, &sn, &sh);
872 if (reason != 0)
873 goto notrans;
874 if ((r->rpool.opts & PF_POOL_TYPEMASK) == PF_POOL_BITMASK)
875 PF_POOLMASK(naddr, naddr, &r->rpool.cur->addr.v.a.mask,
876 daddr, pd->af);
877
878 /* Do not change SCTP ports. */
879 if (pd->proto == IPPROTO_SCTP)
880 break;
881
882 if (r->rpool.proxy_port[1]) {
883 uint32_t tmp_nport;
884
885 tmp_nport = ((ntohs(dport) - ntohs(r->dst.port[0])) %
886 (r->rpool.proxy_port[1] - r->rpool.proxy_port[0] +
887 1)) + r->rpool.proxy_port[0];
888
889 /* Wrap around if necessary. */
890 if (tmp_nport > 65535)
891 tmp_nport -= 65535;
892 nport = htons((uint16_t)tmp_nport);
893 } else if (r->rpool.proxy_port[0])
894 nport = htons(r->rpool.proxy_port[0]);
895 else
896 nport = dport;
897
898 /*
899 * Update the destination port.
900 */
901 *nportp = nport;
902
903 /*
904 * Do we have a source port conflict in the stack state? Try to
905 * modulate the source port if so. Note that this is racy since
906 * the state lookup may not find any matches here but will once
907 * pf_create_state() actually instantiates the state.
908 */
909 bzero(&key, sizeof(key));
910 key.af = pd->af;
911 key.proto = pd->proto;
912 key.port[0] = sport;
913 PF_ACPY(&key.addr[0], saddr, key.af);
914 key.port[1] = nport;
915 PF_ACPY(&key.addr[1], naddr, key.af);
916
917 if (!pf_find_state_all_exists(&key, PF_OUT))
918 break;
919
920 tries = 0;
921
922 low = 50001; /* XXX-MJ PF_NAT_PROXY_PORT_LOW/HIGH */
923 high = 65535;
924 cut = arc4random() % (1 + high - low) + low;
925 for (uint32_t tmp = cut;
926 tmp <= high && tmp <= UINT16_MAX &&
927 tries < V_pf_rdr_srcport_rewrite_tries;
928 tmp++, tries++) {
929 key.port[0] = htons(tmp);
930 if (!pf_find_state_all_exists(&key, PF_OUT)) {
931 /* Update the source port. */
932 (*nkp)->port[0] = htons(tmp);
933 goto out;
934 }
935 }
936 for (uint32_t tmp = cut - 1;
937 tmp >= low && tries < V_pf_rdr_srcport_rewrite_tries;
938 tmp--, tries++) {
939 key.port[0] = htons(tmp);
940 if (!pf_find_state_all_exists(&key, PF_OUT)) {
941 /* Update the source port. */
942 (*nkp)->port[0] = htons(tmp);
943 goto out;
944 }
945 }
946
947 /*
948 * We failed to find a match. Push on ahead anyway, let
949 * pf_state_insert() be the arbiter of whether the state
950 * conflict is tolerable. In particular, with TCP connections
951 * the state may be reused if the TCP state is terminal.
952 */
953 DPFPRINTF(PF_DEBUG_MISC,
954 ("pf: RDR source port allocation failed\n"));
955 break;
956
957 out:
958 DPFPRINTF(PF_DEBUG_MISC,
959 ("pf: RDR source port allocation %u->%u\n",
960 ntohs(sport), ntohs((*nkp)->port[0])));
961 break;
962 }
963 default:
964 panic("%s: unknown action %u", __func__, r->action);
965 }
966
967 /* Return success only if translation really happened. */
968 if (bcmp(*skp, *nkp, sizeof(struct pf_state_key_cmp))) {
969 *rp = r;
970 return (PFRES_MATCH);
971 }
972
973 reason = PFRES_MAX;
974 notrans:
975 uma_zfree(V_pf_state_key_z, *nkp);
976 uma_zfree(V_pf_state_key_z, *skp);
977 *skp = *nkp = NULL;
978
979 return (reason);
980 }
981