1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004 Andre Oppermann, Internet Business Solutions AG
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #include "opt_ipfw.h"
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 #ifndef INET
34 #error IPFIREWALL requires INET.
35 #endif /* INET */
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/module.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/rwlock.h>
45 #include <sys/socket.h>
46 #include <sys/sysctl.h>
47
48 #include <net/if.h>
49 #include <net/if_var.h>
50 #include <net/route.h>
51 #include <net/ethernet.h>
52 #include <net/pfil.h>
53 #include <net/vnet.h>
54
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/ip_fw.h>
60 #ifdef INET6
61 #include <netinet/ip6.h>
62 #include <netinet6/ip6_var.h>
63 #include <netinet6/scope6_var.h>
64 #endif
65
66 #include <netgraph/ng_ipfw.h>
67
68 #include <netpfil/ipfw/ip_fw_private.h>
69
70 #include <machine/in_cksum.h>
71
72 VNET_DEFINE_STATIC(int, fw_enable) = 1;
73 #define V_fw_enable VNET(fw_enable)
74
75 #ifdef INET6
76 VNET_DEFINE_STATIC(int, fw6_enable) = 1;
77 #define V_fw6_enable VNET(fw6_enable)
78 #endif
79
80 VNET_DEFINE_STATIC(int, fwlink_enable) = 0;
81 #define V_fwlink_enable VNET(fwlink_enable)
82
83 int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
84
85 /* Forward declarations. */
86 static int ipfw_divert(struct mbuf **, struct ip_fw_args *, bool);
87
88 #ifdef SYSCTL_NODE
89
90 SYSBEGIN(f1)
91
92 SYSCTL_DECL(_net_inet_ip_fw);
93 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable,
94 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_SECURE3 |
95 CTLFLAG_NEEDGIANT, &VNET_NAME(fw_enable), 0, ipfw_chg_hook, "I",
96 "Enable ipfw");
97 #ifdef INET6
98 SYSCTL_DECL(_net_inet6_ip6_fw);
99 SYSCTL_PROC(_net_inet6_ip6_fw, OID_AUTO, enable,
100 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_SECURE3 |
101 CTLFLAG_NEEDGIANT, &VNET_NAME(fw6_enable), 0, ipfw_chg_hook, "I",
102 "Enable ipfw+6");
103 #endif /* INET6 */
104
105 SYSCTL_DECL(_net_link_ether);
106 SYSCTL_PROC(_net_link_ether, OID_AUTO, ipfw,
107 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_SECURE3 |
108 CTLFLAG_NEEDGIANT, &VNET_NAME(fwlink_enable), 0, ipfw_chg_hook, "I",
109 "Pass ether pkts through firewall");
110
111 SYSEND
112
113 #endif /* SYSCTL_NODE */
114
115 /*
116 * The pfilter hook to pass packets to ipfw_chk and then to
117 * dummynet, divert, netgraph or other modules.
118 * The packet may be consumed.
119 */
120 static pfil_return_t
ipfw_check_packet(struct mbuf ** m0,struct ifnet * ifp,int flags,void * ruleset __unused,struct inpcb * inp)121 ipfw_check_packet(struct mbuf **m0, struct ifnet *ifp, int flags,
122 void *ruleset __unused, struct inpcb *inp)
123 {
124 struct ip_fw_args args;
125 struct m_tag *tag;
126 pfil_return_t ret;
127 int ipfw;
128
129 args.flags = (flags & PFIL_IN) ? IPFW_ARGS_IN : IPFW_ARGS_OUT;
130 args.rule.pkt_mark = 0;
131 again:
132 /*
133 * extract and remove the tag if present. If we are left
134 * with onepass, optimize the outgoing path.
135 */
136 tag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
137 if (tag != NULL) {
138 args.rule = *((struct ipfw_rule_ref *)(tag+1));
139 m_tag_delete(*m0, tag);
140 if (args.rule.info & IPFW_ONEPASS)
141 return (PFIL_PASS);
142 args.flags |= IPFW_ARGS_REF;
143 }
144
145 args.m = *m0;
146 args.ifp = ifp;
147 args.inp = inp;
148
149 ipfw = ipfw_chk(&args);
150 *m0 = args.m;
151
152 KASSERT(*m0 != NULL || ipfw == IP_FW_DENY ||
153 ipfw == IP_FW_NAT64, ("%s: m0 is NULL", __func__));
154
155 ret = PFIL_PASS;
156 switch (ipfw) {
157 case IP_FW_PASS:
158 /* next_hop may be set by ipfw_chk */
159 if ((args.flags & (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR |
160 IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) == 0)
161 break;
162 #if (!defined(INET6) && !defined(INET))
163 ret = PFIL_DROPPED;
164 #else
165 {
166 void *psa;
167 size_t len;
168 #ifdef INET
169 if (args.flags & (IPFW_ARGS_NH4 | IPFW_ARGS_NH4PTR)) {
170 MPASS((args.flags & (IPFW_ARGS_NH4 |
171 IPFW_ARGS_NH4PTR)) != (IPFW_ARGS_NH4 |
172 IPFW_ARGS_NH4PTR));
173 MPASS((args.flags & (IPFW_ARGS_NH6 |
174 IPFW_ARGS_NH6PTR)) == 0);
175 len = sizeof(struct sockaddr_in);
176 psa = (args.flags & IPFW_ARGS_NH4) ?
177 &args.hopstore : args.next_hop;
178 if (in_localip(satosin(psa)->sin_addr))
179 (*m0)->m_flags |= M_FASTFWD_OURS;
180 (*m0)->m_flags |= M_IP_NEXTHOP;
181 }
182 #endif /* INET */
183 #ifdef INET6
184 if (args.flags & (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) {
185 MPASS((args.flags & (IPFW_ARGS_NH6 |
186 IPFW_ARGS_NH6PTR)) != (IPFW_ARGS_NH6 |
187 IPFW_ARGS_NH6PTR));
188 MPASS((args.flags & (IPFW_ARGS_NH4 |
189 IPFW_ARGS_NH4PTR)) == 0);
190 len = sizeof(struct sockaddr_in6);
191 psa = args.next_hop6;
192 (*m0)->m_flags |= M_IP6_NEXTHOP;
193 }
194 #endif /* INET6 */
195 /*
196 * Incoming packets should not be tagged so we do not
197 * m_tag_find. Outgoing packets may be tagged, so we
198 * reuse the tag if present.
199 */
200 tag = (flags & PFIL_IN) ? NULL :
201 m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
202 if (tag != NULL) {
203 m_tag_unlink(*m0, tag);
204 } else {
205 tag = m_tag_get(PACKET_TAG_IPFORWARD, len,
206 M_NOWAIT);
207 if (tag == NULL) {
208 ret = PFIL_DROPPED;
209 break;
210 }
211 }
212 if ((args.flags & IPFW_ARGS_NH6) == 0)
213 bcopy(psa, tag + 1, len);
214 m_tag_prepend(*m0, tag);
215 ret = PFIL_PASS;
216 #ifdef INET6
217 /* IPv6 next hop needs additional handling */
218 if (args.flags & (IPFW_ARGS_NH6 | IPFW_ARGS_NH6PTR)) {
219 struct sockaddr_in6 *sa6;
220
221 sa6 = satosin6(tag + 1);
222 if (args.flags & IPFW_ARGS_NH6) {
223 sa6->sin6_family = AF_INET6;
224 sa6->sin6_len = sizeof(*sa6);
225 sa6->sin6_addr = args.hopstore6.sin6_addr;
226 sa6->sin6_port = args.hopstore6.sin6_port;
227 sa6->sin6_scope_id =
228 args.hopstore6.sin6_scope_id;
229 }
230 /*
231 * If nh6 address is link-local we should convert
232 * it to kernel internal form before doing any
233 * comparisons.
234 */
235 if (sa6_embedscope(sa6, V_ip6_use_defzone) != 0) {
236 ret = PFIL_DROPPED;
237 break;
238 }
239 if (in6_localip(&sa6->sin6_addr))
240 (*m0)->m_flags |= M_FASTFWD_OURS;
241 }
242 #endif /* INET6 */
243 }
244 #endif /* INET || INET6 */
245 break;
246
247 case IP_FW_DENY:
248 ret = PFIL_DROPPED;
249 break;
250
251 case IP_FW_DUMMYNET:
252 if (ip_dn_io_ptr == NULL) {
253 ret = PFIL_DROPPED;
254 break;
255 }
256 MPASS(args.flags & IPFW_ARGS_REF);
257 if (args.flags & (IPFW_ARGS_IP4 | IPFW_ARGS_IP6))
258 (void )ip_dn_io_ptr(m0, &args);
259 else {
260 ret = PFIL_DROPPED;
261 break;
262 }
263 /*
264 * XXX should read the return value.
265 * dummynet normally eats the packet and sets *m0=NULL
266 * unless the packet can be sent immediately. In this
267 * case args is updated and we should re-run the
268 * check without clearing args.
269 */
270 if (*m0 != NULL)
271 goto again;
272 ret = PFIL_CONSUMED;
273 break;
274
275 case IP_FW_TEE:
276 case IP_FW_DIVERT:
277 if (ip_divert_ptr == NULL) {
278 ret = PFIL_DROPPED;
279 break;
280 }
281 MPASS(args.flags & IPFW_ARGS_REF);
282 (void )ipfw_divert(m0, &args, ipfw == IP_FW_TEE);
283 /* continue processing for the original packet (tee). */
284 if (*m0)
285 goto again;
286 ret = PFIL_CONSUMED;
287 break;
288
289 case IP_FW_NGTEE:
290 case IP_FW_NETGRAPH:
291 if (ng_ipfw_input_p == NULL) {
292 ret = PFIL_DROPPED;
293 break;
294 }
295 MPASS(args.flags & IPFW_ARGS_REF);
296 (void )ng_ipfw_input_p(m0, &args, ipfw == IP_FW_NGTEE);
297 if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */
298 goto again; /* continue with packet */
299 ret = PFIL_CONSUMED;
300 break;
301
302 case IP_FW_NAT:
303 /* honor one-pass in case of successful nat */
304 if (V_fw_one_pass)
305 break;
306 goto again;
307
308 case IP_FW_REASS:
309 goto again; /* continue with packet */
310
311 case IP_FW_NAT64:
312 ret = PFIL_CONSUMED;
313 break;
314
315 default:
316 KASSERT(0, ("%s: unknown retval", __func__));
317 }
318
319 if (ret != PFIL_PASS) {
320 if (*m0)
321 FREE_PKT(*m0);
322 *m0 = NULL;
323 }
324
325 return (ret);
326 }
327
328 /*
329 * ipfw processing for ethernet packets (in and out), mbuf version.
330 */
331 static pfil_return_t
ipfw_check_frame_mbuf(struct mbuf ** m0,struct ifnet * ifp,const int flags,void * ruleset __unused,struct inpcb * inp)332 ipfw_check_frame_mbuf(struct mbuf **m0, struct ifnet *ifp, const int flags,
333 void *ruleset __unused, struct inpcb *inp)
334 {
335 struct ip_fw_args args = {
336 .flags = IPFW_ARGS_ETHER |
337 ((flags & PFIL_IN) ? IPFW_ARGS_IN : IPFW_ARGS_OUT),
338 .ifp = ifp,
339 .inp = inp,
340 };
341 struct m_tag *mtag;
342 pfil_return_t ret;
343 int ipfw;
344
345 again:
346 /*
347 * Fetch start point from rule, if any.
348 * Remove the tag if present.
349 */
350 mtag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
351 if (mtag != NULL) {
352 args.rule = *((struct ipfw_rule_ref *)(mtag+1));
353 m_tag_delete(*m0, mtag);
354 if (args.rule.info & IPFW_ONEPASS)
355 return (PFIL_PASS);
356 args.flags |= IPFW_ARGS_REF;
357 }
358 args.m = *m0;
359
360 ipfw = ipfw_chk(&args);
361 *m0 = args.m;
362
363 ret = PFIL_PASS;
364 switch (ipfw) {
365 case IP_FW_PASS:
366 break;
367
368 case IP_FW_DENY:
369 ret = PFIL_DROPPED;
370 break;
371
372 case IP_FW_DUMMYNET:
373 if (ip_dn_io_ptr == NULL) {
374 ret = PFIL_DROPPED;
375 break;
376 }
377 MPASS(args.flags & IPFW_ARGS_REF);
378 ip_dn_io_ptr(m0, &args);
379 return (PFIL_CONSUMED);
380
381 case IP_FW_NGTEE:
382 case IP_FW_NETGRAPH:
383 if (ng_ipfw_input_p == NULL) {
384 ret = PFIL_DROPPED;
385 break;
386 }
387 MPASS(args.flags & IPFW_ARGS_REF);
388 (void )ng_ipfw_input_p(m0, &args, ipfw == IP_FW_NGTEE);
389 if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */
390 goto again; /* continue with packet */
391 ret = PFIL_CONSUMED;
392 break;
393
394 default:
395 KASSERT(0, ("%s: unknown retval", __func__));
396 }
397
398 if (ret != PFIL_PASS) {
399 if (*m0)
400 FREE_PKT(*m0);
401 *m0 = NULL;
402 }
403
404 return (ret);
405 }
406
407 /*
408 * ipfw processing for ethernet packets (in and out), memory pointer version,
409 * two in/out accessors.
410 */
411 static pfil_return_t
ipfw_check_frame_mem(void * mem,u_int len,int flags,struct ifnet * ifp,void * ruleset __unused,struct mbuf ** m)412 ipfw_check_frame_mem(void *mem, u_int len, int flags, struct ifnet *ifp,
413 void *ruleset __unused, struct mbuf **m)
414 {
415 struct ip_fw_args args = {
416 .flags = len | IPFW_ARGS_ETHER |
417 ((flags & PFIL_IN) ? IPFW_ARGS_IN : IPFW_ARGS_OUT),
418 .ifp = ifp,
419 .mem = mem,
420 };
421 pfil_return_t ret;
422 int ipfw;
423
424 *m = NULL;
425 again:
426 ipfw = ipfw_chk(&args);
427
428 ret = PFIL_PASS;
429 switch (ipfw) {
430 case IP_FW_PASS:
431 break;
432
433 case IP_FW_DENY:
434 ret = PFIL_DROPPED;
435 break;
436
437 case IP_FW_DUMMYNET:
438 if (ip_dn_io_ptr == NULL) {
439 ret = PFIL_DROPPED;
440 break;
441 }
442 *m = m_devget(mem, len, 0, ifp, NULL);
443 if (*m == NULL) {
444 ret = PFIL_DROPPED;
445 break;
446 }
447 MPASS(args.flags & IPFW_ARGS_REF);
448 ip_dn_io_ptr(m, &args);
449 return (PFIL_CONSUMED);
450
451 case IP_FW_NGTEE:
452 case IP_FW_NETGRAPH:
453 if (ng_ipfw_input_p == NULL) {
454 ret = PFIL_DROPPED;
455 break;
456 }
457 *m = m_devget(mem, len, 0, ifp, NULL);
458 if (*m == NULL) {
459 ret = PFIL_DROPPED;
460 break;
461 }
462 MPASS(args.flags & IPFW_ARGS_REF);
463 (void )ng_ipfw_input_p(m, &args, ipfw == IP_FW_NGTEE);
464 if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */
465 goto again; /* continue with packet */
466 ret = PFIL_CONSUMED;
467 break;
468
469 default:
470 KASSERT(0, ("%s: unknown retval", __func__));
471 }
472
473 if (*m != NULL && ret == PFIL_PASS)
474 ret = PFIL_REALLOCED;
475
476 return (ret);
477 }
478
479 /* do the divert, return 1 on error 0 on success */
480 static int
ipfw_divert(struct mbuf ** m0,struct ip_fw_args * args,bool tee)481 ipfw_divert(struct mbuf **m0, struct ip_fw_args *args, bool tee)
482 {
483 /*
484 * ipfw_chk() has already tagged the packet with the divert tag.
485 * If tee is set, copy packet and return original.
486 * If not tee, consume packet and send it to divert socket.
487 */
488 struct mbuf *clone;
489 struct ip *ip = mtod(*m0, struct ip *);
490 struct m_tag *tag;
491
492 /* Cloning needed for tee? */
493 if (tee == false) {
494 clone = *m0; /* use the original mbuf */
495 *m0 = NULL;
496 } else {
497 clone = m_dup(*m0, M_NOWAIT);
498 /* If we cannot duplicate the mbuf, we sacrifice the divert
499 * chain and continue with the tee-ed packet.
500 */
501 if (clone == NULL)
502 return 1;
503 }
504
505 /*
506 * Divert listeners can normally handle non-fragmented packets,
507 * but we can only reass in the non-tee case.
508 * This means that listeners on a tee rule may get fragments,
509 * and have to live with that.
510 * Note that we now have the 'reass' ipfw option so if we care
511 * we can do it before a 'tee'.
512 */
513 if (tee == false) switch (ip->ip_v) {
514 case IPVERSION:
515 if (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) {
516 int hlen;
517 struct mbuf *reass;
518
519 reass = ip_reass(clone); /* Reassemble packet. */
520 if (reass == NULL)
521 return 0; /* not an error */
522 /* if reass = NULL then it was consumed by ip_reass */
523 /*
524 * IP header checksum fixup after reassembly and leave header
525 * in network byte order.
526 */
527 ip = mtod(reass, struct ip *);
528 hlen = ip->ip_hl << 2;
529 ip->ip_sum = 0;
530 if (hlen == sizeof(struct ip))
531 ip->ip_sum = in_cksum_hdr(ip);
532 else
533 ip->ip_sum = in_cksum(reass, hlen);
534 clone = reass;
535 }
536 break;
537 #ifdef INET6
538 case IPV6_VERSION >> 4:
539 {
540 struct ip6_hdr *const ip6 = mtod(clone, struct ip6_hdr *);
541
542 if (ip6->ip6_nxt == IPPROTO_FRAGMENT) {
543 int nxt, off;
544
545 off = sizeof(struct ip6_hdr);
546 nxt = frag6_input(&clone, &off, 0);
547 if (nxt == IPPROTO_DONE)
548 return (0);
549 }
550 break;
551 }
552 #endif
553 }
554
555 /* attach a tag to the packet with the reinject info */
556 tag = m_tag_alloc(MTAG_IPFW_RULE, 0,
557 sizeof(struct ipfw_rule_ref), M_NOWAIT);
558 if (tag == NULL) {
559 FREE_PKT(clone);
560 return 1;
561 }
562 *((struct ipfw_rule_ref *)(tag+1)) = args->rule;
563 m_tag_prepend(clone, tag);
564
565 /* Do the dirty job... */
566 ip_divert_ptr(clone, args->flags & IPFW_ARGS_IN);
567 return 0;
568 }
569
570 /*
571 * attach or detach hooks for a given protocol family
572 */
573 VNET_DEFINE_STATIC(pfil_hook_t, ipfw_inet_hook);
574 #define V_ipfw_inet_hook VNET(ipfw_inet_hook)
575 #ifdef INET6
576 VNET_DEFINE_STATIC(pfil_hook_t, ipfw_inet6_hook);
577 #define V_ipfw_inet6_hook VNET(ipfw_inet6_hook)
578 #endif
579 VNET_DEFINE_STATIC(pfil_hook_t, ipfw_link_hook);
580 #define V_ipfw_link_hook VNET(ipfw_link_hook)
581
582 static void
ipfw_hook(int pf)583 ipfw_hook(int pf)
584 {
585 struct pfil_hook_args pha = {
586 .pa_version = PFIL_VERSION,
587 .pa_flags = PFIL_IN | PFIL_OUT,
588 .pa_modname = "ipfw",
589 };
590 pfil_hook_t *h;
591
592 switch (pf) {
593 case AF_INET:
594 pha.pa_mbuf_chk = ipfw_check_packet;
595 pha.pa_type = PFIL_TYPE_IP4;
596 pha.pa_rulname = "default";
597 h = &V_ipfw_inet_hook;
598 break;
599 #ifdef INET6
600 case AF_INET6:
601 pha.pa_mbuf_chk = ipfw_check_packet;
602 pha.pa_type = PFIL_TYPE_IP6;
603 pha.pa_rulname = "default6";
604 h = &V_ipfw_inet6_hook;
605 break;
606 #endif
607 case AF_LINK:
608 pha.pa_mbuf_chk = ipfw_check_frame_mbuf;
609 pha.pa_mem_chk = ipfw_check_frame_mem;
610 pha.pa_type = PFIL_TYPE_ETHERNET;
611 pha.pa_rulname = "default-link";
612 h = &V_ipfw_link_hook;
613 break;
614 }
615
616 *h = pfil_add_hook(&pha);
617 }
618
619 static void
ipfw_unhook(int pf)620 ipfw_unhook(int pf)
621 {
622
623 switch (pf) {
624 case AF_INET:
625 pfil_remove_hook(V_ipfw_inet_hook);
626 break;
627 #ifdef INET6
628 case AF_INET6:
629 pfil_remove_hook(V_ipfw_inet6_hook);
630 break;
631 #endif
632 case AF_LINK:
633 pfil_remove_hook(V_ipfw_link_hook);
634 break;
635 }
636 }
637
638 static int
ipfw_link(int pf,bool unlink)639 ipfw_link(int pf, bool unlink)
640 {
641 struct pfil_link_args pla;
642
643 pla.pa_version = PFIL_VERSION;
644 pla.pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR;
645 if (unlink)
646 pla.pa_flags |= PFIL_UNLINK;
647
648 switch (pf) {
649 case AF_INET:
650 pla.pa_head = V_inet_pfil_head;
651 pla.pa_hook = V_ipfw_inet_hook;
652 break;
653 #ifdef INET6
654 case AF_INET6:
655 pla.pa_head = V_inet6_pfil_head;
656 pla.pa_hook = V_ipfw_inet6_hook;
657 break;
658 #endif
659 case AF_LINK:
660 pla.pa_head = V_link_pfil_head;
661 pla.pa_hook = V_ipfw_link_hook;
662 break;
663 }
664
665 return (pfil_link(&pla));
666 }
667
668 int
ipfw_attach_hooks(void)669 ipfw_attach_hooks(void)
670 {
671 int error = 0;
672
673 ipfw_hook(AF_INET);
674 TUNABLE_INT_FETCH("net.inet.ip.fw.enable", &V_fw_enable);
675 if (V_fw_enable && (error = ipfw_link(AF_INET, false)) != 0)
676 printf("ipfw_hook() error\n");
677 #ifdef INET6
678 ipfw_hook(AF_INET6);
679 TUNABLE_INT_FETCH("net.inet6.ip6.fw.enable", &V_fw6_enable);
680 if (V_fw6_enable && (error = ipfw_link(AF_INET6, false)) != 0)
681 printf("ipfw6_hook() error\n");
682 #endif
683 ipfw_hook(AF_LINK);
684 TUNABLE_INT_FETCH("net.link.ether.ipfw", &V_fwlink_enable);
685 if (V_fwlink_enable && (error = ipfw_link(AF_LINK, false)) != 0)
686 printf("ipfw_link_hook() error\n");
687
688 return (error);
689 }
690
691 void
ipfw_detach_hooks(void)692 ipfw_detach_hooks(void)
693 {
694
695 ipfw_unhook(AF_INET);
696 #ifdef INET6
697 ipfw_unhook(AF_INET6);
698 #endif
699 ipfw_unhook(AF_LINK);
700 }
701
702 int
ipfw_chg_hook(SYSCTL_HANDLER_ARGS)703 ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
704 {
705 int newval;
706 int error;
707 int af;
708
709 if (arg1 == &V_fw_enable)
710 af = AF_INET;
711 #ifdef INET6
712 else if (arg1 == &V_fw6_enable)
713 af = AF_INET6;
714 #endif
715 else if (arg1 == &V_fwlink_enable)
716 af = AF_LINK;
717 else
718 return (EINVAL);
719
720 newval = *(int *)arg1;
721 /* Handle sysctl change */
722 error = sysctl_handle_int(oidp, &newval, 0, req);
723
724 if (error)
725 return (error);
726
727 /* Formalize new value */
728 newval = (newval) ? 1 : 0;
729
730 if (*(int *)arg1 == newval)
731 return (0);
732
733 error = ipfw_link(af, newval == 0 ? true : false);
734 if (error)
735 return (error);
736 *(int *)arg1 = newval;
737
738 return (0);
739 }
740 /* end of file */
741