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