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