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:
297 * pick a different source address since we're out
298 * of free port choices for the current one.
300 if (pf_map_addr(af, r, saddr, naddr, &init_addr, sn))
304 case PF_POOL_SRCHASH:
305 case PF_POOL_BITMASK:
309 } while (! PF_AEQ(&init_addr, naddr, af) );
310 return (1); /* none available */
314 pf_map_addr(sa_family_t af, struct pf_rule *r, struct pf_addr *saddr,
315 struct pf_addr *naddr, struct pf_addr *init_addr, struct pf_src_node **sn)
317 struct pf_pool *rpool = &r->rpool;
318 struct pf_addr *raddr = NULL, *rmask = NULL;
320 /* Try to find a src_node if none was given and this
321 is a sticky-address rule. */
322 if (*sn == NULL && r->rpool.opts & PF_POOL_STICKYADDR &&
323 (r->rpool.opts & PF_POOL_TYPEMASK) != PF_POOL_NONE)
324 *sn = pf_find_src_node(saddr, r, af, 0);
326 /* If a src_node was found or explicitly given and it has a non-zero
327 route address, use this address. A zeroed address is found if the
328 src node was created just a moment ago in pf_create_state and it
329 needs to be filled in with routing decision calculated here. */
330 if (*sn != NULL && !PF_AZERO(&(*sn)->raddr, af)) {
331 /* If the supplied address is the same as the current one we've
332 * been asked before, so tell the caller that there's no other
333 * address to be had. */
334 if (PF_AEQ(naddr, &(*sn)->raddr, af))
337 PF_ACPY(naddr, &(*sn)->raddr, af);
338 if (V_pf_status.debug >= PF_DEBUG_MISC) {
339 printf("pf_map_addr: src tracking maps ");
340 pf_print_host(saddr, 0, af);
342 pf_print_host(naddr, 0, af);
348 /* Find the route using chosen algorithm. Store the found route
349 in src_node if it was given or found. */
350 if (rpool->cur->addr.type == PF_ADDR_NOROUTE)
352 if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
356 if (rpool->cur->addr.p.dyn->pfid_acnt4 < 1 &&
357 (rpool->opts & PF_POOL_TYPEMASK) !=
360 raddr = &rpool->cur->addr.p.dyn->pfid_addr4;
361 rmask = &rpool->cur->addr.p.dyn->pfid_mask4;
366 if (rpool->cur->addr.p.dyn->pfid_acnt6 < 1 &&
367 (rpool->opts & PF_POOL_TYPEMASK) !=
370 raddr = &rpool->cur->addr.p.dyn->pfid_addr6;
371 rmask = &rpool->cur->addr.p.dyn->pfid_mask6;
375 } else if (rpool->cur->addr.type == PF_ADDR_TABLE) {
376 if ((rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_ROUNDROBIN)
377 return (1); /* unsupported */
379 raddr = &rpool->cur->addr.v.a.addr;
380 rmask = &rpool->cur->addr.v.a.mask;
383 switch (rpool->opts & PF_POOL_TYPEMASK) {
385 PF_ACPY(naddr, raddr, af);
387 case PF_POOL_BITMASK:
388 PF_POOLMASK(naddr, raddr, rmask, saddr, af);
391 if (init_addr != NULL && PF_AZERO(init_addr, af)) {
395 rpool->counter.addr32[0] = htonl(arc4random());
400 if (rmask->addr32[3] != 0xffffffff)
401 rpool->counter.addr32[3] =
405 if (rmask->addr32[2] != 0xffffffff)
406 rpool->counter.addr32[2] =
410 if (rmask->addr32[1] != 0xffffffff)
411 rpool->counter.addr32[1] =
415 if (rmask->addr32[0] != 0xffffffff)
416 rpool->counter.addr32[0] =
421 PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
422 PF_ACPY(init_addr, naddr, af);
425 PF_AINC(&rpool->counter, af);
426 PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af);
429 case PF_POOL_SRCHASH:
431 unsigned char hash[16];
433 pf_hash(saddr, (struct pf_addr *)&hash, &rpool->key, af);
434 PF_POOLMASK(naddr, raddr, rmask, (struct pf_addr *)&hash, af);
437 case PF_POOL_ROUNDROBIN:
439 struct pf_pooladdr *acur = rpool->cur;
442 * XXXGL: in the round-robin case we need to store
443 * the round-robin machine state in the rule, thus
444 * forwarding thread needs to modify rule.
446 * This is done w/o locking, because performance is assumed
447 * more important than round-robin precision.
449 * In the simpliest case we just update the "rpool->cur"
450 * pointer. However, if pool contains tables or dynamic
451 * addresses, then "tblidx" is also used to store machine
452 * state. Since "tblidx" is int, concurrent access to it can't
453 * lead to inconsistence, only to lost of precision.
455 * Things get worse, if table contains not hosts, but
456 * prefixes. In this case counter also stores machine state,
457 * and for IPv6 address, counter can't be updated atomically.
458 * Probably, using round-robin on a table containing IPv6
459 * prefixes (or even IPv4) would cause a panic.
462 if (rpool->cur->addr.type == PF_ADDR_TABLE) {
463 if (!pfr_pool_get(rpool->cur->addr.p.tbl,
464 &rpool->tblidx, &rpool->counter, af))
466 } else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
467 if (!pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
468 &rpool->tblidx, &rpool->counter, af))
470 } else if (pf_match_addr(0, raddr, rmask, &rpool->counter, af))
474 if (TAILQ_NEXT(rpool->cur, entries) == NULL)
475 rpool->cur = TAILQ_FIRST(&rpool->list);
477 rpool->cur = TAILQ_NEXT(rpool->cur, entries);
478 if (rpool->cur->addr.type == PF_ADDR_TABLE) {
480 if (pfr_pool_get(rpool->cur->addr.p.tbl,
481 &rpool->tblidx, &rpool->counter, af)) {
482 /* table contains no address of type 'af' */
483 if (rpool->cur != acur)
487 } else if (rpool->cur->addr.type == PF_ADDR_DYNIFTL) {
489 if (pfr_pool_get(rpool->cur->addr.p.dyn->pfid_kt,
490 &rpool->tblidx, &rpool->counter, af)) {
491 /* table contains no address of type 'af' */
492 if (rpool->cur != acur)
497 raddr = &rpool->cur->addr.v.a.addr;
498 rmask = &rpool->cur->addr.v.a.mask;
499 PF_ACPY(&rpool->counter, raddr, af);
503 PF_ACPY(naddr, &rpool->counter, af);
504 if (init_addr != NULL && PF_AZERO(init_addr, af))
505 PF_ACPY(init_addr, naddr, af);
506 PF_AINC(&rpool->counter, af);
511 PF_ACPY(&(*sn)->raddr, naddr, af);
513 if (V_pf_status.debug >= PF_DEBUG_MISC &&
514 (rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_NONE) {
515 printf("pf_map_addr: selected address ");
516 pf_print_host(naddr, 0, af);
524 pf_get_translation(struct pf_pdesc *pd, struct mbuf *m, int off, int direction,
525 struct pfi_kif *kif, struct pf_src_node **sn,
526 struct pf_state_key **skp, struct pf_state_key **nkp,
527 struct pf_addr *saddr, struct pf_addr *daddr,
528 uint16_t sport, uint16_t dport, struct pf_anchor_stackframe *anchor_stack)
530 struct pf_rule *r = NULL;
531 struct pf_addr *naddr;
535 KASSERT(*skp == NULL, ("*skp not NULL"));
536 KASSERT(*nkp == NULL, ("*nkp not NULL"));
538 if (direction == PF_OUT) {
539 r = pf_match_translation(pd, m, off, direction, kif, saddr,
540 sport, daddr, dport, PF_RULESET_BINAT, anchor_stack);
542 r = pf_match_translation(pd, m, off, direction, kif,
543 saddr, sport, daddr, dport, PF_RULESET_NAT,
546 r = pf_match_translation(pd, m, off, direction, kif, saddr,
547 sport, daddr, dport, PF_RULESET_RDR, anchor_stack);
549 r = pf_match_translation(pd, m, off, direction, kif,
550 saddr, sport, daddr, dport, PF_RULESET_BINAT,
564 *skp = pf_state_key_setup(pd, saddr, daddr, sport, dport);
567 *nkp = pf_state_key_clone(*skp);
569 uma_zfree(V_pf_state_key_z, *skp);
574 /* XXX We only modify one side for now. */
575 naddr = &(*nkp)->addr[1];
576 nport = &(*nkp)->port[1];
580 if (pf_get_sport(pd->af, pd->proto, r, saddr, sport, daddr,
581 dport, naddr, nport, r->rpool.proxy_port[0],
582 r->rpool.proxy_port[1], sn)) {
583 DPFPRINTF(PF_DEBUG_MISC,
584 ("pf: NAT proxy port allocation (%u-%u) failed\n",
585 r->rpool.proxy_port[0], r->rpool.proxy_port[1]));
592 if (r->rpool.cur->addr.type == PF_ADDR_DYNIFTL){
596 if (r->rpool.cur->addr.p.dyn->
600 &r->rpool.cur->addr.p.dyn->
602 &r->rpool.cur->addr.p.dyn->
603 pfid_mask4, saddr, AF_INET);
608 if (r->rpool.cur->addr.p.dyn->
612 &r->rpool.cur->addr.p.dyn->
614 &r->rpool.cur->addr.p.dyn->
615 pfid_mask6, saddr, AF_INET6);
621 &r->rpool.cur->addr.v.a.addr,
622 &r->rpool.cur->addr.v.a.mask, saddr,
626 if (r->src.addr.type == PF_ADDR_DYNIFTL) {
630 if (r->src.addr.p.dyn-> pfid_acnt4 < 1)
633 &r->src.addr.p.dyn->pfid_addr4,
634 &r->src.addr.p.dyn->pfid_mask4,
640 if (r->src.addr.p.dyn->pfid_acnt6 < 1)
643 &r->src.addr.p.dyn->pfid_addr6,
644 &r->src.addr.p.dyn->pfid_mask6,
650 PF_POOLMASK(naddr, &r->src.addr.v.a.addr,
651 &r->src.addr.v.a.mask, daddr, pd->af);
656 if (pf_map_addr(pd->af, r, saddr, naddr, NULL, sn))
658 if ((r->rpool.opts & PF_POOL_TYPEMASK) == PF_POOL_BITMASK)
659 PF_POOLMASK(naddr, naddr, &r->rpool.cur->addr.v.a.mask,
662 if (r->rpool.proxy_port[1]) {
665 tmp_nport = ((ntohs(dport) - ntohs(r->dst.port[0])) %
666 (r->rpool.proxy_port[1] - r->rpool.proxy_port[0] +
667 1)) + r->rpool.proxy_port[0];
669 /* Wrap around if necessary. */
670 if (tmp_nport > 65535)
672 *nport = htons((uint16_t)tmp_nport);
673 } else if (r->rpool.proxy_port[0])
674 *nport = htons(r->rpool.proxy_port[0]);
678 panic("%s: unknown action %u", __func__, r->action);
681 /* Return success only if translation really happened. */
682 if (bcmp(*skp, *nkp, sizeof(struct pf_state_key_cmp)))
686 uma_zfree(V_pf_state_key_z, *nkp);
687 uma_zfree(V_pf_state_key_z, *skp);