2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2001 Daniel Hartmeier
5 * Copyright (c) 2002 - 2008 Henning Brauer
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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.
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.
36 * $OpenBSD: pf_lb.c,v 1.2 2009/02/12 02:13:15 sthen Exp $
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
44 #include "opt_inet6.h"
46 #include <sys/param.h>
49 #include <sys/socket.h>
50 #include <sys/sysctl.h>
54 #include <net/pfvar.h>
55 #include <net/if_pflog.h>
57 #define DPFPRINTF(n, x) if (V_pf_status.debug >= (n)) printf x
59 static void pf_hash(struct pf_addr *, struct pf_addr *,
60 struct pf_poolhashkey *, sa_family_t);
61 static struct pf_rule *pf_match_translation(struct pf_pdesc *, struct mbuf *,
62 int, int, struct pfi_kif *,
63 struct pf_addr *, u_int16_t, struct pf_addr *,
64 uint16_t, int, struct pf_anchor_stackframe *);
65 static int pf_get_sport(sa_family_t, uint8_t, struct pf_rule *,
66 struct pf_addr *, uint16_t, struct pf_addr *, uint16_t, struct pf_addr *,
67 uint16_t *, uint16_t, uint16_t, struct pf_src_node **);
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); \
83 * hash function based on bridge_hash in if_bridge.c
86 pf_hash(struct pf_addr *inaddr, struct pf_addr *hash,
87 struct pf_poolhashkey *key, sa_family_t af)
89 u_int32_t a = 0x9e3779b9, b = 0x9e3779b9, c = key->key32[0];
94 a += inaddr->addr32[0];
97 hash->addr32[0] = c + key->key32[2];
102 a += inaddr->addr32[0];
103 b += inaddr->addr32[2];
106 a += inaddr->addr32[1];
107 b += inaddr->addr32[3];
111 a += inaddr->addr32[2];
112 b += inaddr->addr32[1];
116 a += inaddr->addr32[3];
117 b += inaddr->addr32[0];
126 static struct pf_rule *
127 pf_match_translation(struct pf_pdesc *pd, struct mbuf *m, int off,
128 int direction, struct pfi_kif *kif, struct pf_addr *saddr, u_int16_t sport,
129 struct pf_addr *daddr, uint16_t dport, int rs_num,
130 struct pf_anchor_stackframe *anchor_stack)
132 struct pf_rule *r, *rm = NULL;
133 struct pf_ruleset *ruleset = NULL;
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;
143 if (r->action == PF_BINAT && direction == PF_IN) {
145 if (r->rpool.cur != NULL)
146 xdst = &r->rpool.cur->addr;
153 if (pfi_kif_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,
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);
190 if (r->rtableid >= 0)
191 rtableid = r->rtableid;
192 if (r->anchor == NULL) {
195 pf_step_into_anchor(anchor_stack, &asd,
196 &ruleset, rs_num, &r, NULL, NULL);
199 pf_step_out_of_anchor(anchor_stack, &asd, &ruleset,
200 rs_num, &r, NULL, NULL);
203 if (tag > 0 && pf_tag_packet(m, pd, tag))
206 M_SETFIB(m, rtableid);
208 if (rm != NULL && (rm->action == PF_NONAT ||
209 rm->action == PF_NORDR || rm->action == PF_NOBINAT))
215 pf_get_sport(sa_family_t af, u_int8_t proto, struct pf_rule *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_src_node **sn)
220 struct pf_state_key_cmp key;
221 struct pf_addr init_addr;
223 bzero(&init_addr, sizeof(init_addr));
224 if (pf_map_addr(af, r, saddr, naddr, &init_addr, sn))
227 if (proto == IPPROTO_ICMP) {
232 bzero(&key, sizeof(key));
236 PF_ACPY(&key.addr[0], daddr, key.af);
239 PF_ACPY(&key.addr[1], naddr, key.af);
242 * port search; start random, step;
243 * similar 2 portloop in in_pcbbind
245 if (!(proto == IPPROTO_TCP || proto == IPPROTO_UDP ||
246 proto == IPPROTO_ICMP) || (low == 0 && high == 0)) {
248 * XXX bug: icmp states don't use the id on both sides.
249 * (traceroute -I through nat)
252 if (pf_find_state_all(&key, PF_IN, NULL) == NULL) {
256 } else if (low == high) {
257 key.port[1] = htons(low);
258 if (pf_find_state_all(&key, PF_IN, NULL) == NULL) {
272 cut = arc4random() % (1 + high - low) + low;
273 /* low <= cut <= high */
274 for (tmp = cut; tmp <= high && tmp <= 0xffff; ++tmp) {
275 key.port[1] = htons(tmp);
276 if (pf_find_state_all(&key, PF_IN, NULL) ==
283 for (tmp -= 1; tmp >= low && tmp <= 0xffff; --tmp) {
284 key.port[1] = htons(tmp);
285 if (pf_find_state_all(&key, PF_IN, NULL) ==
293 switch (r->rpool.opts & PF_POOL_TYPEMASK) {
295 case PF_POOL_ROUNDROBIN:
296 if (pf_map_addr(af, r, saddr, naddr, &init_addr, sn))
300 case PF_POOL_SRCHASH:
301 case PF_POOL_BITMASK:
305 } while (! PF_AEQ(&init_addr, naddr, af) );
306 return (1); /* none available */
310 pf_map_addr(sa_family_t af, struct pf_rule *r, struct pf_addr *saddr,
311 struct pf_addr *naddr, struct pf_addr *init_addr, struct pf_src_node **sn)
313 struct pf_pool *rpool = &r->rpool;
314 struct pf_addr *raddr = NULL, *rmask = NULL;
316 /* Try to find a src_node if none was given and this
317 is a sticky-address rule. */
318 if (*sn == NULL && r->rpool.opts & PF_POOL_STICKYADDR &&
319 (r->rpool.opts & PF_POOL_TYPEMASK) != PF_POOL_NONE)
320 *sn = pf_find_src_node(saddr, r, af, 0);
322 /* If a src_node was found or explicitly given and it has a non-zero
323 route address, use this address. A zeroed address is found if the
324 src node was created just a moment ago in pf_create_state and it
325 needs to be filled in with routing decision calculated here. */
326 if (*sn != NULL && !PF_AZERO(&(*sn)->raddr, af)) {
327 PF_ACPY(naddr, &(*sn)->raddr, af);
328 if (V_pf_status.debug >= PF_DEBUG_MISC) {
329 printf("pf_map_addr: src tracking maps ");
330 pf_print_host(saddr, 0, af);
332 pf_print_host(naddr, 0, af);
338 /* Find the route using chosen algorithm. Store the found route
339 in src_node if it was given or found. */
340 if (rpool->cur->addr.type == PF_ADDR_NOROUTE)
342 if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
346 if (rpool->cur->addr.p.dyn->pfid_acnt4 < 1 &&
347 (rpool->opts & PF_POOL_TYPEMASK) !=
350 raddr = &rpool->cur->addr.p.dyn->pfid_addr4;
351 rmask = &rpool->cur->addr.p.dyn->pfid_mask4;
356 if (rpool->cur->addr.p.dyn->pfid_acnt6 < 1 &&
357 (rpool->opts & PF_POOL_TYPEMASK) !=
360 raddr = &rpool->cur->addr.p.dyn->pfid_addr6;
361 rmask = &rpool->cur->addr.p.dyn->pfid_mask6;
365 } else if (rpool->cur->addr.type == PF_ADDR_TABLE) {
366 if ((rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_ROUNDROBIN)
367 return (1); /* unsupported */
369 raddr = &rpool->cur->addr.v.a.addr;
370 rmask = &rpool->cur->addr.v.a.mask;
373 switch (rpool->opts & PF_POOL_TYPEMASK) {
375 PF_ACPY(naddr, raddr, af);
377 case PF_POOL_BITMASK:
378 PF_POOLMASK(naddr, raddr, rmask, saddr, af);
381 if (init_addr != NULL && PF_AZERO(init_addr, af)) {
385 rpool->counter.addr32[0] = htonl(arc4random());
390 if (rmask->addr32[3] != 0xffffffff)
391 rpool->counter.addr32[3] =
395 if (rmask->addr32[2] != 0xffffffff)
396 rpool->counter.addr32[2] =
400 if (rmask->addr32[1] != 0xffffffff)
401 rpool->counter.addr32[1] =
405 if (rmask->addr32[0] != 0xffffffff)
406 rpool->counter.addr32[0] =
411 PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
412 PF_ACPY(init_addr, naddr, af);
415 PF_AINC(&rpool->counter, af);
416 PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
419 case PF_POOL_SRCHASH:
421 unsigned char hash[16];
423 pf_hash(saddr, (struct pf_addr *)&hash, &rpool->key, af);
424 PF_POOLMASK(naddr, raddr, rmask, (struct pf_addr *)&hash, af);
427 case PF_POOL_ROUNDROBIN:
429 struct pf_pooladdr *acur = rpool->cur;
432 * XXXGL: in the round-robin case we need to store
433 * the round-robin machine state in the rule, thus
434 * forwarding thread needs to modify rule.
436 * This is done w/o locking, because performance is assumed
437 * more important than round-robin precision.
439 * In the simpliest case we just update the "rpool->cur"
440 * pointer. However, if pool contains tables or dynamic
441 * addresses, then "tblidx" is also used to store machine
442 * state. Since "tblidx" is int, concurrent access to it can't
443 * lead to inconsistence, only to lost of precision.
445 * Things get worse, if table contains not hosts, but
446 * prefixes. In this case counter also stores machine state,
447 * and for IPv6 address, counter can't be updated atomically.
448 * Probably, using round-robin on a table containing IPv6
449 * prefixes (or even IPv4) would cause a panic.
452 if (rpool->cur->addr.type == PF_ADDR_TABLE) {
453 if (!pfr_pool_get(rpool->cur->addr.p.tbl,
454 &rpool->tblidx, &rpool->counter, af))
456 } else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
457 if (!pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
458 &rpool->tblidx, &rpool->counter, af))
460 } else if (pf_match_addr(0, raddr, rmask, &rpool->counter, af))
464 if (TAILQ_NEXT(rpool->cur, entries) == NULL)
465 rpool->cur = TAILQ_FIRST(&rpool->list);
467 rpool->cur = TAILQ_NEXT(rpool->cur, entries);
468 if (rpool->cur->addr.type == PF_ADDR_TABLE) {
470 if (pfr_pool_get(rpool->cur->addr.p.tbl,
471 &rpool->tblidx, &rpool->counter, af)) {
472 /* table contains no address of type 'af' */
473 if (rpool->cur != acur)
477 } else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
479 if (pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
480 &rpool->tblidx, &rpool->counter, af)) {
481 /* table contains no address of type 'af' */
482 if (rpool->cur != acur)
487 raddr = &rpool->cur->addr.v.a.addr;
488 rmask = &rpool->cur->addr.v.a.mask;
489 PF_ACPY(&rpool->counter, raddr, af);
493 PF_ACPY(naddr, &rpool->counter, af);
494 if (init_addr != NULL && PF_AZERO(init_addr, af))
495 PF_ACPY(init_addr, naddr, af);
496 PF_AINC(&rpool->counter, af);
501 PF_ACPY(&(*sn)->raddr, naddr, af);
503 if (V_pf_status.debug >= PF_DEBUG_MISC &&
504 (rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_NONE) {
505 printf("pf_map_addr: selected address ");
506 pf_print_host(naddr, 0, af);
514 pf_get_translation(struct pf_pdesc *pd, struct mbuf *m, int off, int direction,
515 struct pfi_kif *kif, struct pf_src_node **sn,
516 struct pf_state_key **skp, struct pf_state_key **nkp,
517 struct pf_addr *saddr, struct pf_addr *daddr,
518 uint16_t sport, uint16_t dport, struct pf_anchor_stackframe *anchor_stack)
520 struct pf_rule *r = NULL;
521 struct pf_addr *naddr;
525 KASSERT(*skp == NULL, ("*skp not NULL"));
526 KASSERT(*nkp == NULL, ("*nkp not NULL"));
528 if (direction == PF_OUT) {
529 r = pf_match_translation(pd, m, off, direction, kif, saddr,
530 sport, daddr, dport, PF_RULESET_BINAT, anchor_stack);
532 r = pf_match_translation(pd, m, off, direction, kif,
533 saddr, sport, daddr, dport, PF_RULESET_NAT,
536 r = pf_match_translation(pd, m, off, direction, kif, saddr,
537 sport, daddr, dport, PF_RULESET_RDR, anchor_stack);
539 r = pf_match_translation(pd, m, off, direction, kif,
540 saddr, sport, daddr, dport, PF_RULESET_BINAT,
554 *skp = pf_state_key_setup(pd, saddr, daddr, sport, dport);
557 *nkp = pf_state_key_clone(*skp);
559 uma_zfree(V_pf_state_key_z, *skp);
564 /* XXX We only modify one side for now. */
565 naddr = &(*nkp)->addr[1];
566 nport = &(*nkp)->port[1];
570 if (pf_get_sport(pd->af, pd->proto, r, saddr, sport, daddr,
571 dport, naddr, nport, r->rpool.proxy_port[0],
572 r->rpool.proxy_port[1], sn)) {
573 DPFPRINTF(PF_DEBUG_MISC,
574 ("pf: NAT proxy port allocation (%u-%u) failed\n",
575 r->rpool.proxy_port[0], r->rpool.proxy_port[1]));
582 if (r->rpool.cur->addr.type == PF_ADDR_DYNIFTL){
586 if (r->rpool.cur->addr.p.dyn->
590 &r->rpool.cur->addr.p.dyn->
592 &r->rpool.cur->addr.p.dyn->
593 pfid_mask4, saddr, AF_INET);
598 if (r->rpool.cur->addr.p.dyn->
602 &r->rpool.cur->addr.p.dyn->
604 &r->rpool.cur->addr.p.dyn->
605 pfid_mask6, saddr, AF_INET6);
611 &r->rpool.cur->addr.v.a.addr,
612 &r->rpool.cur->addr.v.a.mask, saddr,
616 if (r->src.addr.type == PF_ADDR_DYNIFTL) {
620 if (r->src.addr.p.dyn-> pfid_acnt4 < 1)
623 &r->src.addr.p.dyn->pfid_addr4,
624 &r->src.addr.p.dyn->pfid_mask4,
630 if (r->src.addr.p.dyn->pfid_acnt6 < 1)
633 &r->src.addr.p.dyn->pfid_addr6,
634 &r->src.addr.p.dyn->pfid_mask6,
640 PF_POOLMASK(naddr, &r->src.addr.v.a.addr,
641 &r->src.addr.v.a.mask, daddr, pd->af);
646 if (pf_map_addr(pd->af, r, saddr, naddr, NULL, sn))
648 if ((r->rpool.opts & PF_POOL_TYPEMASK) == PF_POOL_BITMASK)
649 PF_POOLMASK(naddr, naddr, &r->rpool.cur->addr.v.a.mask,
652 if (r->rpool.proxy_port[1]) {
655 tmp_nport = ((ntohs(dport) - ntohs(r->dst.port[0])) %
656 (r->rpool.proxy_port[1] - r->rpool.proxy_port[0] +
657 1)) + r->rpool.proxy_port[0];
659 /* Wrap around if necessary. */
660 if (tmp_nport > 65535)
662 *nport = htons((uint16_t)tmp_nport);
663 } else if (r->rpool.proxy_port[0])
664 *nport = htons(r->rpool.proxy_port[0]);
668 panic("%s: unknown action %u", __func__, r->action);
671 /* Return success only if translation really happened. */
672 if (bcmp(*skp, *nkp, sizeof(struct pf_state_key_cmp)))
676 uma_zfree(V_pf_state_key_z, *nkp);
677 uma_zfree(V_pf_state_key_z, *skp);