107#define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs)
108
109#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
110static int default_to_accept = 1;
111#else
112static int default_to_accept;
113#endif
114
115VNET_DEFINE(int, autoinc_step);
116
117/*
118 * Each rule belongs to one of 32 different sets (0..31).
119 * The variable set_disable contains one bit per set.
120 * If the bit is set, all rules in the corresponding set
121 * are disabled. Set RESVD_SET(31) is reserved for the default rule
122 * and rules that are not deleted by the flush command,
123 * and CANNOT be disabled.
124 * Rules in set RESVD_SET can only be deleted individually.
125 */
126VNET_DEFINE(u_int32_t, set_disable);
127#define V_set_disable VNET(set_disable)
128
129VNET_DEFINE(int, fw_verbose);
130/* counter for ipfw_log(NULL...) */
131VNET_DEFINE(u_int64_t, norule_counter);
132VNET_DEFINE(int, verbose_limit);
133
134/* layer3_chain contains the list of rules for layer 3 */
135VNET_DEFINE(struct ip_fw_chain, layer3_chain);
136
137ipfw_nat_t *ipfw_nat_ptr = NULL;
138struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
139ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
140ipfw_nat_cfg_t *ipfw_nat_del_ptr;
141ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
142ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
143
144#ifdef SYSCTL_NODE
145uint32_t dummy_def = IPFW_DEFAULT_RULE;
146uint32_t dummy_tables_max = IPFW_TABLES_MAX;
147
148SYSBEGIN(f3)
149
150SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
151SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
152 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
153 "Only do a single pass through ipfw when using dummynet(4)");
154SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
155 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
156 "Rule number auto-increment step");
157SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose,
158 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
159 "Log matches to ipfw rules");
160SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
161 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
162 "Set upper limit of matches of ipfw rules logged");
163SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
164 &dummy_def, 0,
165 "The default/max possible rule number.");
166SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_RD,
167 &dummy_tables_max, 0,
168 "The maximum number of tables.");
169SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
170 &default_to_accept, 0,
171 "Make the default rule accept all packets.");
172TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept);
173SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count,
174 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
175 "Number of static rules");
176
177#ifdef INET6
178SYSCTL_DECL(_net_inet6_ip6);
179SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
180SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
181 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0,
182 "Deny packets with unknown IPv6 Extension Headers");
183#endif /* INET6 */
184
185SYSEND
186
187#endif /* SYSCTL_NODE */
188
189
190/*
191 * Some macros used in the various matching options.
192 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
193 * Other macros just cast void * into the appropriate type
194 */
195#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
196#define TCP(p) ((struct tcphdr *)(p))
197#define SCTP(p) ((struct sctphdr *)(p))
198#define UDP(p) ((struct udphdr *)(p))
199#define ICMP(p) ((struct icmphdr *)(p))
200#define ICMP6(p) ((struct icmp6_hdr *)(p))
201
202static __inline int
203icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
204{
205 int type = icmp->icmp_type;
206
207 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
208}
209
210#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
211 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
212
213static int
214is_icmp_query(struct icmphdr *icmp)
215{
216 int type = icmp->icmp_type;
217
218 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
219}
220#undef TT
221
222/*
223 * The following checks use two arrays of 8 or 16 bits to store the
224 * bits that we want set or clear, respectively. They are in the
225 * low and high half of cmd->arg1 or cmd->d[0].
226 *
227 * We scan options and store the bits we find set. We succeed if
228 *
229 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
230 *
231 * The code is sometimes optimized not to store additional variables.
232 */
233
234static int
235flags_match(ipfw_insn *cmd, u_int8_t bits)
236{
237 u_char want_clear;
238 bits = ~bits;
239
240 if ( ((cmd->arg1 & 0xff) & bits) != 0)
241 return 0; /* some bits we want set were clear */
242 want_clear = (cmd->arg1 >> 8) & 0xff;
243 if ( (want_clear & bits) != want_clear)
244 return 0; /* some bits we want clear were set */
245 return 1;
246}
247
248static int
249ipopts_match(struct ip *ip, ipfw_insn *cmd)
250{
251 int optlen, bits = 0;
252 u_char *cp = (u_char *)(ip + 1);
253 int x = (ip->ip_hl << 2) - sizeof (struct ip);
254
255 for (; x > 0; x -= optlen, cp += optlen) {
256 int opt = cp[IPOPT_OPTVAL];
257
258 if (opt == IPOPT_EOL)
259 break;
260 if (opt == IPOPT_NOP)
261 optlen = 1;
262 else {
263 optlen = cp[IPOPT_OLEN];
264 if (optlen <= 0 || optlen > x)
265 return 0; /* invalid or truncated */
266 }
267 switch (opt) {
268
269 default:
270 break;
271
272 case IPOPT_LSRR:
273 bits |= IP_FW_IPOPT_LSRR;
274 break;
275
276 case IPOPT_SSRR:
277 bits |= IP_FW_IPOPT_SSRR;
278 break;
279
280 case IPOPT_RR:
281 bits |= IP_FW_IPOPT_RR;
282 break;
283
284 case IPOPT_TS:
285 bits |= IP_FW_IPOPT_TS;
286 break;
287 }
288 }
289 return (flags_match(cmd, bits));
290}
291
292static int
293tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
294{
295 int optlen, bits = 0;
296 u_char *cp = (u_char *)(tcp + 1);
297 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
298
299 for (; x > 0; x -= optlen, cp += optlen) {
300 int opt = cp[0];
301 if (opt == TCPOPT_EOL)
302 break;
303 if (opt == TCPOPT_NOP)
304 optlen = 1;
305 else {
306 optlen = cp[1];
307 if (optlen <= 0)
308 break;
309 }
310
311 switch (opt) {
312
313 default:
314 break;
315
316 case TCPOPT_MAXSEG:
317 bits |= IP_FW_TCPOPT_MSS;
318 break;
319
320 case TCPOPT_WINDOW:
321 bits |= IP_FW_TCPOPT_WINDOW;
322 break;
323
324 case TCPOPT_SACK_PERMITTED:
325 case TCPOPT_SACK:
326 bits |= IP_FW_TCPOPT_SACK;
327 break;
328
329 case TCPOPT_TIMESTAMP:
330 bits |= IP_FW_TCPOPT_TS;
331 break;
332
333 }
334 }
335 return (flags_match(cmd, bits));
336}
337
338static int
339iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
340{
341 if (ifp == NULL) /* no iface with this packet, match fails */
342 return 0;
343 /* Check by name or by IP address */
344 if (cmd->name[0] != '\0') { /* match by name */
345 /* Check name */
346 if (cmd->p.glob) {
347 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
348 return(1);
349 } else {
350 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
351 return(1);
352 }
353 } else {
354#ifdef __FreeBSD__ /* and OSX too ? */
355 struct ifaddr *ia;
356
357 if_addr_rlock(ifp);
358 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
359 if (ia->ifa_addr->sa_family != AF_INET)
360 continue;
361 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
362 (ia->ifa_addr))->sin_addr.s_addr) {
363 if_addr_runlock(ifp);
364 return(1); /* match */
365 }
366 }
367 if_addr_runlock(ifp);
368#endif /* __FreeBSD__ */
369 }
370 return(0); /* no match, fail ... */
371}
372
373/*
374 * The verify_path function checks if a route to the src exists and
375 * if it is reachable via ifp (when provided).
376 *
377 * The 'verrevpath' option checks that the interface that an IP packet
378 * arrives on is the same interface that traffic destined for the
379 * packet's source address would be routed out of.
380 * The 'versrcreach' option just checks that the source address is
381 * reachable via any route (except default) in the routing table.
382 * These two are a measure to block forged packets. This is also
383 * commonly known as "anti-spoofing" or Unicast Reverse Path
384 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
385 * is purposely reminiscent of the Cisco IOS command,
386 *
387 * ip verify unicast reverse-path
388 * ip verify unicast source reachable-via any
389 *
390 * which implements the same functionality. But note that the syntax
391 * is misleading, and the check may be performed on all IP packets
392 * whether unicast, multicast, or broadcast.
393 */
394static int
395verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
396{
397#ifndef __FreeBSD__
398 return 0;
399#else
400 struct route ro;
401 struct sockaddr_in *dst;
402
403 bzero(&ro, sizeof(ro));
404
405 dst = (struct sockaddr_in *)&(ro.ro_dst);
406 dst->sin_family = AF_INET;
407 dst->sin_len = sizeof(*dst);
408 dst->sin_addr = src;
409 in_rtalloc_ign(&ro, 0, fib);
410
411 if (ro.ro_rt == NULL)
412 return 0;
413
414 /*
415 * If ifp is provided, check for equality with rtentry.
416 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
417 * in order to pass packets injected back by if_simloop():
418 * if useloopback == 1 routing entry (via lo0) for our own address
419 * may exist, so we need to handle routing assymetry.
420 */
421 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
422 RTFREE(ro.ro_rt);
423 return 0;
424 }
425
426 /* if no ifp provided, check if rtentry is not default route */
427 if (ifp == NULL &&
428 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
429 RTFREE(ro.ro_rt);
430 return 0;
431 }
432
433 /* or if this is a blackhole/reject route */
434 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
435 RTFREE(ro.ro_rt);
436 return 0;
437 }
438
439 /* found valid route */
440 RTFREE(ro.ro_rt);
441 return 1;
442#endif /* __FreeBSD__ */
443}
444
445#ifdef INET6
446/*
447 * ipv6 specific rules here...
448 */
449static __inline int
450icmp6type_match (int type, ipfw_insn_u32 *cmd)
451{
452 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
453}
454
455static int
456flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
457{
458 int i;
459 for (i=0; i <= cmd->o.arg1; ++i )
460 if (curr_flow == cmd->d[i] )
461 return 1;
462 return 0;
463}
464
465/* support for IP6_*_ME opcodes */
466static int
467search_ip6_addr_net (struct in6_addr * ip6_addr)
468{
469 struct ifnet *mdc;
470 struct ifaddr *mdc2;
471 struct in6_ifaddr *fdm;
472 struct in6_addr copia;
473
474 TAILQ_FOREACH(mdc, &V_ifnet, if_link) {
475 if_addr_rlock(mdc);
476 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) {
477 if (mdc2->ifa_addr->sa_family == AF_INET6) {
478 fdm = (struct in6_ifaddr *)mdc2;
479 copia = fdm->ia_addr.sin6_addr;
480 /* need for leaving scope_id in the sock_addr */
481 in6_clearscope(&copia);
482 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) {
483 if_addr_runlock(mdc);
484 return 1;
485 }
486 }
487 }
488 if_addr_runlock(mdc);
489 }
490 return 0;
491}
492
493static int
494verify_path6(struct in6_addr *src, struct ifnet *ifp)
495{
496 struct route_in6 ro;
497 struct sockaddr_in6 *dst;
498
499 bzero(&ro, sizeof(ro));
500
501 dst = (struct sockaddr_in6 * )&(ro.ro_dst);
502 dst->sin6_family = AF_INET6;
503 dst->sin6_len = sizeof(*dst);
504 dst->sin6_addr = *src;
505 /* XXX MRT 0 for ipv6 at this time */
506 rtalloc_ign((struct route *)&ro, 0);
507
508 if (ro.ro_rt == NULL)
509 return 0;
510
511 /*
512 * if ifp is provided, check for equality with rtentry
513 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
514 * to support the case of sending packets to an address of our own.
515 * (where the former interface is the first argument of if_simloop()
516 * (=ifp), the latter is lo0)
517 */
518 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
519 RTFREE(ro.ro_rt);
520 return 0;
521 }
522
523 /* if no ifp provided, check if rtentry is not default route */
524 if (ifp == NULL &&
525 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
526 RTFREE(ro.ro_rt);
527 return 0;
528 }
529
530 /* or if this is a blackhole/reject route */
531 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
532 RTFREE(ro.ro_rt);
533 return 0;
534 }
535
536 /* found valid route */
537 RTFREE(ro.ro_rt);
538 return 1;
539
540}
541
542static int
543is_icmp6_query(int icmp6_type)
544{
545 if ((icmp6_type <= ICMP6_MAXTYPE) &&
546 (icmp6_type == ICMP6_ECHO_REQUEST ||
547 icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
548 icmp6_type == ICMP6_WRUREQUEST ||
549 icmp6_type == ICMP6_FQDN_QUERY ||
550 icmp6_type == ICMP6_NI_QUERY))
551 return (1);
552
553 return (0);
554}
555
556static void
557send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
558{
559 struct mbuf *m;
560
561 m = args->m;
562 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
563 struct tcphdr *tcp;
564 tcp = (struct tcphdr *)((char *)ip6 + hlen);
565
566 if ((tcp->th_flags & TH_RST) == 0) {
567 struct mbuf *m0;
568 m0 = ipfw_send_pkt(args->m, &(args->f_id),
569 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
570 tcp->th_flags | TH_RST);
571 if (m0 != NULL)
572 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
573 NULL);
574 }
575 FREE_PKT(m);
576 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
577#if 0
578 /*
579 * Unlike above, the mbufs need to line up with the ip6 hdr,
580 * as the contents are read. We need to m_adj() the
581 * needed amount.
582 * The mbuf will however be thrown away so we can adjust it.
583 * Remember we did an m_pullup on it already so we
584 * can make some assumptions about contiguousness.
585 */
586 if (args->L3offset)
587 m_adj(m, args->L3offset);
588#endif
589 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
590 } else
591 FREE_PKT(m);
592
593 args->m = NULL;
594}
595
596#endif /* INET6 */
597
598
599/*
600 * sends a reject message, consuming the mbuf passed as an argument.
601 */
602static void
603send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
604{
605
606#if 0
607 /* XXX When ip is not guaranteed to be at mtod() we will
608 * need to account for this */
609 * The mbuf will however be thrown away so we can adjust it.
610 * Remember we did an m_pullup on it already so we
611 * can make some assumptions about contiguousness.
612 */
613 if (args->L3offset)
614 m_adj(m, args->L3offset);
615#endif
616 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
617 /* We need the IP header in host order for icmp_error(). */
618 SET_HOST_IPLEN(ip);
619 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
620 } else if (args->f_id.proto == IPPROTO_TCP) {
621 struct tcphdr *const tcp =
622 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
623 if ( (tcp->th_flags & TH_RST) == 0) {
624 struct mbuf *m;
625 m = ipfw_send_pkt(args->m, &(args->f_id),
626 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
627 tcp->th_flags | TH_RST);
628 if (m != NULL)
629 ip_output(m, NULL, NULL, 0, NULL, NULL);
630 }
631 FREE_PKT(args->m);
632 } else
633 FREE_PKT(args->m);
634 args->m = NULL;
635}
636
637/*
638 * Support for uid/gid/jail lookup. These tests are expensive
639 * (because we may need to look into the list of active sockets)
640 * so we cache the results. ugid_lookupp is 0 if we have not
641 * yet done a lookup, 1 if we succeeded, and -1 if we tried
642 * and failed. The function always returns the match value.
643 * We could actually spare the variable and use *uc, setting
644 * it to '(void *)check_uidgid if we have no info, NULL if
645 * we tried and failed, or any other value if successful.
646 */
647static int
648check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif,
649 struct in_addr dst_ip, u_int16_t dst_port, struct in_addr src_ip,
650 u_int16_t src_port, int *ugid_lookupp,
651 struct ucred **uc, struct inpcb *inp)
652{
653#ifndef __FreeBSD__
654 return cred_check(insn, proto, oif,
655 dst_ip, dst_port, src_ip, src_port,
656 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
657#else /* FreeBSD */
658 struct inpcbinfo *pi;
659 int wildcard;
660 struct inpcb *pcb;
661 int match;
662
663 /*
664 * Check to see if the UDP or TCP stack supplied us with
665 * the PCB. If so, rather then holding a lock and looking
666 * up the PCB, we can use the one that was supplied.
667 */
668 if (inp && *ugid_lookupp == 0) {
669 INP_LOCK_ASSERT(inp);
670 if (inp->inp_socket != NULL) {
671 *uc = crhold(inp->inp_cred);
672 *ugid_lookupp = 1;
673 } else
674 *ugid_lookupp = -1;
675 }
676 /*
677 * If we have already been here and the packet has no
678 * PCB entry associated with it, then we can safely
679 * assume that this is a no match.
680 */
681 if (*ugid_lookupp == -1)
682 return (0);
683 if (proto == IPPROTO_TCP) {
684 wildcard = 0;
685 pi = &V_tcbinfo;
686 } else if (proto == IPPROTO_UDP) {
687 wildcard = INPLOOKUP_WILDCARD;
688 pi = &V_udbinfo;
689 } else
690 return 0;
691 match = 0;
692 if (*ugid_lookupp == 0) {
693 INP_INFO_RLOCK(pi);
694 pcb = (oif) ?
695 in_pcblookup_hash(pi,
696 dst_ip, htons(dst_port),
697 src_ip, htons(src_port),
698 wildcard, oif) :
699 in_pcblookup_hash(pi,
700 src_ip, htons(src_port),
701 dst_ip, htons(dst_port),
702 wildcard, NULL);
703 if (pcb != NULL) {
704 *uc = crhold(pcb->inp_cred);
705 *ugid_lookupp = 1;
706 }
707 INP_INFO_RUNLOCK(pi);
708 if (*ugid_lookupp == 0) {
709 /*
710 * We tried and failed, set the variable to -1
711 * so we will not try again on this packet.
712 */
713 *ugid_lookupp = -1;
714 return (0);
715 }
716 }
717 if (insn->o.opcode == O_UID)
718 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
719 else if (insn->o.opcode == O_GID)
720 match = groupmember((gid_t)insn->d[0], *uc);
721 else if (insn->o.opcode == O_JAIL)
722 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
723 return match;
724#endif /* __FreeBSD__ */
725}
726
727/*
728 * Helper function to set args with info on the rule after the matching
729 * one. slot is precise, whereas we guess rule_id as they are
730 * assigned sequentially.
731 */
732static inline void
733set_match(struct ip_fw_args *args, int slot,
734 struct ip_fw_chain *chain)
735{
736 args->rule.chain_id = chain->id;
737 args->rule.slot = slot + 1; /* we use 0 as a marker */
738 args->rule.rule_id = 1 + chain->map[slot]->id;
739 args->rule.rulenum = chain->map[slot]->rulenum;
740}
741
742/*
743 * The main check routine for the firewall.
744 *
745 * All arguments are in args so we can modify them and return them
746 * back to the caller.
747 *
748 * Parameters:
749 *
750 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
751 * Starts with the IP header.
752 * args->eh (in) Mac header if present, NULL for layer3 packet.
753 * args->L3offset Number of bytes bypassed if we came from L2.
754 * e.g. often sizeof(eh) ** NOTYET **
755 * args->oif Outgoing interface, NULL if packet is incoming.
756 * The incoming interface is in the mbuf. (in)
757 * args->divert_rule (in/out)
758 * Skip up to the first rule past this rule number;
759 * upon return, non-zero port number for divert or tee.
760 *
761 * args->rule Pointer to the last matching rule (in/out)
762 * args->next_hop Socket we are forwarding to (out).
763 * args->f_id Addresses grabbed from the packet (out)
764 * args->rule.info a cookie depending on rule action
765 *
766 * Return value:
767 *
768 * IP_FW_PASS the packet must be accepted
769 * IP_FW_DENY the packet must be dropped
770 * IP_FW_DIVERT divert packet, port in m_tag
771 * IP_FW_TEE tee packet, port in m_tag
772 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie
773 * IP_FW_NETGRAPH into netgraph, cookie args->cookie
774 * args->rule contains the matching rule,
775 * args->rule.info has additional information.
776 *
777 */
778int
779ipfw_chk(struct ip_fw_args *args)
780{
781
782 /*
783 * Local variables holding state while processing a packet:
784 *
785 * IMPORTANT NOTE: to speed up the processing of rules, there
786 * are some assumption on the values of the variables, which
787 * are documented here. Should you change them, please check
788 * the implementation of the various instructions to make sure
789 * that they still work.
790 *
791 * args->eh The MAC header. It is non-null for a layer2
792 * packet, it is NULL for a layer-3 packet.
793 * **notyet**
794 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
795 *
796 * m | args->m Pointer to the mbuf, as received from the caller.
797 * It may change if ipfw_chk() does an m_pullup, or if it
798 * consumes the packet because it calls send_reject().
799 * XXX This has to change, so that ipfw_chk() never modifies
800 * or consumes the buffer.
801 * ip is the beginning of the ip(4 or 6) header.
802 * Calculated by adding the L3offset to the start of data.
803 * (Until we start using L3offset, the packet is
804 * supposed to start with the ip header).
805 */
806 struct mbuf *m = args->m;
807 struct ip *ip = mtod(m, struct ip *);
808
809 /*
810 * For rules which contain uid/gid or jail constraints, cache
811 * a copy of the users credentials after the pcb lookup has been
812 * executed. This will speed up the processing of rules with
813 * these types of constraints, as well as decrease contention
814 * on pcb related locks.
815 */
816#ifndef __FreeBSD__
817 struct bsd_ucred ucred_cache;
818#else
819 struct ucred *ucred_cache = NULL;
820#endif
821 int ucred_lookup = 0;
822
823 /*
824 * oif | args->oif If NULL, ipfw_chk has been called on the
825 * inbound path (ether_input, ip_input).
826 * If non-NULL, ipfw_chk has been called on the outbound path
827 * (ether_output, ip_output).
828 */
829 struct ifnet *oif = args->oif;
830
831 int f_pos = 0; /* index of current rule in the array */
832 int retval = 0;
833
834 /*
835 * hlen The length of the IP header.
836 */
837 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
838
839 /*
840 * offset The offset of a fragment. offset != 0 means that
841 * we have a fragment at this offset of an IPv4 packet.
842 * offset == 0 means that (if this is an IPv4 packet)
843 * this is the first or only fragment.
844 * For IPv6 offset == 0 means there is no Fragment Header.
845 * If offset != 0 for IPv6 always use correct mask to
846 * get the correct offset because we add IP6F_MORE_FRAG
847 * to be able to dectect the first fragment which would
848 * otherwise have offset = 0.
849 */
850 u_short offset = 0;
851
852 /*
853 * Local copies of addresses. They are only valid if we have
854 * an IP packet.
855 *
856 * proto The protocol. Set to 0 for non-ip packets,
857 * or to the protocol read from the packet otherwise.
858 * proto != 0 means that we have an IPv4 packet.
859 *
860 * src_port, dst_port port numbers, in HOST format. Only
861 * valid for TCP and UDP packets.
862 *
863 * src_ip, dst_ip ip addresses, in NETWORK format.
864 * Only valid for IPv4 packets.
865 */
866 uint8_t proto;
867 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */
868 struct in_addr src_ip, dst_ip; /* NOTE: network format */
869 uint16_t iplen=0;
870 int pktlen;
871 uint16_t etype = 0; /* Host order stored ether type */
872
873 /*
874 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
875 * MATCH_NONE when checked and not matched (q = NULL),
876 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
877 */
878 int dyn_dir = MATCH_UNKNOWN;
879 ipfw_dyn_rule *q = NULL;
880 struct ip_fw_chain *chain = &V_layer3_chain;
881
882 /*
883 * We store in ulp a pointer to the upper layer protocol header.
884 * In the ipv4 case this is easy to determine from the header,
885 * but for ipv6 we might have some additional headers in the middle.
886 * ulp is NULL if not found.
887 */
888 void *ulp = NULL; /* upper layer protocol pointer. */
889
890 /* XXX ipv6 variables */
891 int is_ipv6 = 0;
892 uint8_t icmp6_type = 0;
893 uint16_t ext_hd = 0; /* bits vector for extension header filtering */
894 /* end of ipv6 variables */
895
896 int is_ipv4 = 0;
897
898 int done = 0; /* flag to exit the outer loop */
899
900 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
901 return (IP_FW_PASS); /* accept */
902
903 dst_ip.s_addr = 0; /* make sure it is initialized */
904 src_ip.s_addr = 0; /* make sure it is initialized */
905 pktlen = m->m_pkthdr.len;
906 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
907 proto = args->f_id.proto = 0; /* mark f_id invalid */
908 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
909
910/*
911 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
912 * then it sets p to point at the offset "len" in the mbuf. WARNING: the
913 * pointer might become stale after other pullups (but we never use it
914 * this way).
915 */
916#define PULLUP_TO(_len, p, T) \
917do { \
918 int x = (_len) + sizeof(T); \
919 if ((m)->m_len < x) { \
920 args->m = m = m_pullup(m, x); \
921 if (m == NULL) \
922 goto pullup_failed; \
923 } \
924 p = (mtod(m, char *) + (_len)); \
925} while (0)
926
927 /*
928 * if we have an ether header,
929 */
930 if (args->eh)
931 etype = ntohs(args->eh->ether_type);
932
933 /* Identify IP packets and fill up variables. */
934 if (pktlen >= sizeof(struct ip6_hdr) &&
935 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
936 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
937 is_ipv6 = 1;
938 args->f_id.addr_type = 6;
939 hlen = sizeof(struct ip6_hdr);
940 proto = ip6->ip6_nxt;
941
942 /* Search extension headers to find upper layer protocols */
943 while (ulp == NULL) {
944 switch (proto) {
945 case IPPROTO_ICMPV6:
946 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
947 icmp6_type = ICMP6(ulp)->icmp6_type;
948 break;
949
950 case IPPROTO_TCP:
951 PULLUP_TO(hlen, ulp, struct tcphdr);
952 dst_port = TCP(ulp)->th_dport;
953 src_port = TCP(ulp)->th_sport;
954 /* save flags for dynamic rules */
955 args->f_id._flags = TCP(ulp)->th_flags;
956 break;
957
958 case IPPROTO_SCTP:
959 PULLUP_TO(hlen, ulp, struct sctphdr);
960 src_port = SCTP(ulp)->src_port;
961 dst_port = SCTP(ulp)->dest_port;
962 break;
963
964 case IPPROTO_UDP:
965 PULLUP_TO(hlen, ulp, struct udphdr);
966 dst_port = UDP(ulp)->uh_dport;
967 src_port = UDP(ulp)->uh_sport;
968 break;
969
970 case IPPROTO_HOPOPTS: /* RFC 2460 */
971 PULLUP_TO(hlen, ulp, struct ip6_hbh);
972 ext_hd |= EXT_HOPOPTS;
973 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
974 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
975 ulp = NULL;
976 break;
977
978 case IPPROTO_ROUTING: /* RFC 2460 */
979 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
980 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
981 case 0:
982 ext_hd |= EXT_RTHDR0;
983 break;
984 case 2:
985 ext_hd |= EXT_RTHDR2;
986 break;
987 default:
988 printf("IPFW2: IPV6 - Unknown Routing "
989 "Header type(%d)\n",
990 ((struct ip6_rthdr *)ulp)->ip6r_type);
991 if (V_fw_deny_unknown_exthdrs)
992 return (IP_FW_DENY);
993 break;
994 }
995 ext_hd |= EXT_ROUTING;
996 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
997 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
998 ulp = NULL;
999 break;
1000
1001 case IPPROTO_FRAGMENT: /* RFC 2460 */
1002 PULLUP_TO(hlen, ulp, struct ip6_frag);
1003 ext_hd |= EXT_FRAGMENT;
1004 hlen += sizeof (struct ip6_frag);
1005 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1006 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1007 IP6F_OFF_MASK;
1008 /* Add IP6F_MORE_FRAG for offset of first
1009 * fragment to be != 0. */
1010 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg &
1011 IP6F_MORE_FRAG;
1012 if (offset == 0) {
1013 printf("IPFW2: IPV6 - Invalid Fragment "
1014 "Header\n");
1015 if (V_fw_deny_unknown_exthdrs)
1016 return (IP_FW_DENY);
1017 break;
1018 }
1019 args->f_id.extra =
1020 ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1021 ulp = NULL;
1022 break;
1023
1024 case IPPROTO_DSTOPTS: /* RFC 2460 */
1025 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1026 ext_hd |= EXT_DSTOPTS;
1027 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1028 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1029 ulp = NULL;
1030 break;
1031
1032 case IPPROTO_AH: /* RFC 2402 */
1033 PULLUP_TO(hlen, ulp, struct ip6_ext);
1034 ext_hd |= EXT_AH;
1035 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1036 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1037 ulp = NULL;
1038 break;
1039
1040 case IPPROTO_ESP: /* RFC 2406 */
1041 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1042 /* Anything past Seq# is variable length and
1043 * data past this ext. header is encrypted. */
1044 ext_hd |= EXT_ESP;
1045 break;
1046
1047 case IPPROTO_NONE: /* RFC 2460 */
1048 /*
1049 * Packet ends here, and IPv6 header has
1050 * already been pulled up. If ip6e_len!=0
1051 * then octets must be ignored.
1052 */
1053 ulp = ip; /* non-NULL to get out of loop. */
1054 break;
1055
1056 case IPPROTO_OSPFIGP:
1057 /* XXX OSPF header check? */
1058 PULLUP_TO(hlen, ulp, struct ip6_ext);
1059 break;
1060
1061 case IPPROTO_PIM:
1062 /* XXX PIM header check? */
1063 PULLUP_TO(hlen, ulp, struct pim);
1064 break;
1065
1066 case IPPROTO_CARP:
1067 PULLUP_TO(hlen, ulp, struct carp_header);
1068 if (((struct carp_header *)ulp)->carp_version !=
1069 CARP_VERSION)
1070 return (IP_FW_DENY);
1071 if (((struct carp_header *)ulp)->carp_type !=
1072 CARP_ADVERTISEMENT)
1073 return (IP_FW_DENY);
1074 break;
1075
1076 case IPPROTO_IPV6: /* RFC 2893 */
1077 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1078 break;
1079
1080 case IPPROTO_IPV4: /* RFC 2893 */
1081 PULLUP_TO(hlen, ulp, struct ip);
1082 break;
1083
1084 default:
1085 printf("IPFW2: IPV6 - Unknown Extension "
1086 "Header(%d), ext_hd=%x\n", proto, ext_hd);
1087 if (V_fw_deny_unknown_exthdrs)
1088 return (IP_FW_DENY);
1089 PULLUP_TO(hlen, ulp, struct ip6_ext);
1090 break;
1091 } /*switch */
1092 }
1093 ip = mtod(m, struct ip *);
1094 ip6 = (struct ip6_hdr *)ip;
1095 args->f_id.src_ip6 = ip6->ip6_src;
1096 args->f_id.dst_ip6 = ip6->ip6_dst;
1097 args->f_id.src_ip = 0;
1098 args->f_id.dst_ip = 0;
1099 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1100 } else if (pktlen >= sizeof(struct ip) &&
1101 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1102 is_ipv4 = 1;
1103 hlen = ip->ip_hl << 2;
1104 args->f_id.addr_type = 4;
1105
1106 /*
1107 * Collect parameters into local variables for faster matching.
1108 */
1109 proto = ip->ip_p;
1110 src_ip = ip->ip_src;
1111 dst_ip = ip->ip_dst;
1112 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1113 iplen = ntohs(ip->ip_len);
1114 pktlen = iplen < pktlen ? iplen : pktlen;
1115
1116 if (offset == 0) {
1117 switch (proto) {
1118 case IPPROTO_TCP:
1119 PULLUP_TO(hlen, ulp, struct tcphdr);
1120 dst_port = TCP(ulp)->th_dport;
1121 src_port = TCP(ulp)->th_sport;
1122 /* save flags for dynamic rules */
1123 args->f_id._flags = TCP(ulp)->th_flags;
1124 break;
1125
1126 case IPPROTO_UDP:
1127 PULLUP_TO(hlen, ulp, struct udphdr);
1128 dst_port = UDP(ulp)->uh_dport;
1129 src_port = UDP(ulp)->uh_sport;
1130 break;
1131
1132 case IPPROTO_ICMP:
1133 PULLUP_TO(hlen, ulp, struct icmphdr);
1134 //args->f_id.flags = ICMP(ulp)->icmp_type;
1135 break;
1136
1137 default:
1138 break;
1139 }
1140 }
1141
1142 ip = mtod(m, struct ip *);
1143 args->f_id.src_ip = ntohl(src_ip.s_addr);
1144 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1145 }
1146#undef PULLUP_TO
1147 if (proto) { /* we may have port numbers, store them */
1148 args->f_id.proto = proto;
1149 args->f_id.src_port = src_port = ntohs(src_port);
1150 args->f_id.dst_port = dst_port = ntohs(dst_port);
1151 }
1152
1153 IPFW_RLOCK(chain);
1154 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1155 IPFW_RUNLOCK(chain);
1156 return (IP_FW_PASS); /* accept */
1157 }
1158 if (args->rule.slot) {
1159 /*
1160 * Packet has already been tagged as a result of a previous
1161 * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1162 * REASS, NETGRAPH, DIVERT/TEE...)
1163 * Validate the slot and continue from the next one
1164 * if still present, otherwise do a lookup.
1165 */
1166 f_pos = (args->rule.chain_id == chain->id) ?
1167 args->rule.slot :
1168 ipfw_find_rule(chain, args->rule.rulenum,
1169 args->rule.rule_id);
1170 } else {
1171 f_pos = 0;
1172 }
1173
1174 /*
1175 * Now scan the rules, and parse microinstructions for each rule.
1176 * We have two nested loops and an inner switch. Sometimes we
1177 * need to break out of one or both loops, or re-enter one of
1178 * the loops with updated variables. Loop variables are:
1179 *
1180 * f_pos (outer loop) points to the current rule.
1181 * On output it points to the matching rule.
1182 * done (outer loop) is used as a flag to break the loop.
1183 * l (inner loop) residual length of current rule.
1184 * cmd points to the current microinstruction.
1185 *
1186 * We break the inner loop by setting l=0 and possibly
1187 * cmdlen=0 if we don't want to advance cmd.
1188 * We break the outer loop by setting done=1
1189 * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1190 * as needed.
1191 */
1192 for (; f_pos < chain->n_rules; f_pos++) {
1193 ipfw_insn *cmd;
1194 uint32_t tablearg = 0;
1195 int l, cmdlen, skip_or; /* skip rest of OR block */
1196 struct ip_fw *f;
1197
1198 f = chain->map[f_pos];
1199 if (V_set_disable & (1 << f->set) )
1200 continue;
1201
1202 skip_or = 0;
1203 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1204 l -= cmdlen, cmd += cmdlen) {
1205 int match;
1206
1207 /*
1208 * check_body is a jump target used when we find a
1209 * CHECK_STATE, and need to jump to the body of
1210 * the target rule.
1211 */
1212
1213/* check_body: */
1214 cmdlen = F_LEN(cmd);
1215 /*
1216 * An OR block (insn_1 || .. || insn_n) has the
1217 * F_OR bit set in all but the last instruction.
1218 * The first match will set "skip_or", and cause
1219 * the following instructions to be skipped until
1220 * past the one with the F_OR bit clear.
1221 */
1222 if (skip_or) { /* skip this instruction */
1223 if ((cmd->len & F_OR) == 0)
1224 skip_or = 0; /* next one is good */
1225 continue;
1226 }
1227 match = 0; /* set to 1 if we succeed */
1228
1229 switch (cmd->opcode) {
1230 /*
1231 * The first set of opcodes compares the packet's
1232 * fields with some pattern, setting 'match' if a
1233 * match is found. At the end of the loop there is
1234 * logic to deal with F_NOT and F_OR flags associated
1235 * with the opcode.
1236 */
1237 case O_NOP:
1238 match = 1;
1239 break;
1240
1241 case O_FORWARD_MAC:
1242 printf("ipfw: opcode %d unimplemented\n",
1243 cmd->opcode);
1244 break;
1245
1246 case O_GID:
1247 case O_UID:
1248 case O_JAIL:
1249 /*
1250 * We only check offset == 0 && proto != 0,
1251 * as this ensures that we have a
1252 * packet with the ports info.
1253 */
1254 if (offset!=0)
1255 break;
1256 if (is_ipv6) /* XXX to be fixed later */
1257 break;
1258 if (proto == IPPROTO_TCP ||
1259 proto == IPPROTO_UDP)
1260 match = check_uidgid(
1261 (ipfw_insn_u32 *)cmd,
1262 proto, oif,
1263 dst_ip, dst_port,
1264 src_ip, src_port, &ucred_lookup,
1265#ifdef __FreeBSD__
1266 &ucred_cache, args->inp);
1267#else
1268 (void *)&ucred_cache,
1269 (struct inpcb *)args->m);
1270#endif
1271 break;
1272
1273 case O_RECV:
1274 match = iface_match(m->m_pkthdr.rcvif,
1275 (ipfw_insn_if *)cmd);
1276 break;
1277
1278 case O_XMIT:
1279 match = iface_match(oif, (ipfw_insn_if *)cmd);
1280 break;
1281
1282 case O_VIA:
1283 match = iface_match(oif ? oif :
1284 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1285 break;
1286
1287 case O_MACADDR2:
1288 if (args->eh != NULL) { /* have MAC header */
1289 u_int32_t *want = (u_int32_t *)
1290 ((ipfw_insn_mac *)cmd)->addr;
1291 u_int32_t *mask = (u_int32_t *)
1292 ((ipfw_insn_mac *)cmd)->mask;
1293 u_int32_t *hdr = (u_int32_t *)args->eh;
1294
1295 match =
1296 ( want[0] == (hdr[0] & mask[0]) &&
1297 want[1] == (hdr[1] & mask[1]) &&
1298 want[2] == (hdr[2] & mask[2]) );
1299 }
1300 break;
1301
1302 case O_MAC_TYPE:
1303 if (args->eh != NULL) {
1304 u_int16_t *p =
1305 ((ipfw_insn_u16 *)cmd)->ports;
1306 int i;
1307
1308 for (i = cmdlen - 1; !match && i>0;
1309 i--, p += 2)
1310 match = (etype >= p[0] &&
1311 etype <= p[1]);
1312 }
1313 break;
1314
1315 case O_FRAG:
1316 match = (offset != 0);
1317 break;
1318
1319 case O_IN: /* "out" is "not in" */
1320 match = (oif == NULL);
1321 break;
1322
1323 case O_LAYER2:
1324 match = (args->eh != NULL);
1325 break;
1326
1327 case O_DIVERTED:
1328 {
1329 /* For diverted packets, args->rule.info
1330 * contains the divert port (in host format)
1331 * reason and direction.
1332 */
1333 uint32_t i = args->rule.info;
1334 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1335 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1336 }
1337 break;
1338
1339 case O_PROTO:
1340 /*
1341 * We do not allow an arg of 0 so the
1342 * check of "proto" only suffices.
1343 */
1344 match = (proto == cmd->arg1);
1345 break;
1346
1347 case O_IP_SRC:
1348 match = is_ipv4 &&
1349 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1350 src_ip.s_addr);
1351 break;
1352
1353 case O_IP_SRC_LOOKUP:
1354 case O_IP_DST_LOOKUP:
1355 if (is_ipv4) {
1356 uint32_t key =
1357 (cmd->opcode == O_IP_DST_LOOKUP) ?
1358 dst_ip.s_addr : src_ip.s_addr;
1359 uint32_t v = 0;
1360
1361 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1362 /* generic lookup. The key must be
1363 * in 32bit big-endian format.
1364 */
1365 v = ((ipfw_insn_u32 *)cmd)->d[1];
1366 if (v == 0)
1367 key = dst_ip.s_addr;
1368 else if (v == 1)
1369 key = src_ip.s_addr;
1370 else if (v == 6) /* dscp */
1371 key = (ip->ip_tos >> 2) & 0x3f;
1372 else if (offset != 0)
1373 break;
1374 else if (proto != IPPROTO_TCP &&
1375 proto != IPPROTO_UDP)
1376 break;
1377 else if (v == 2)
1378 key = htonl(dst_port);
1379 else if (v == 3)
1380 key = htonl(src_port);
1381 else if (v == 4 || v == 5) {
1382 check_uidgid(
1383 (ipfw_insn_u32 *)cmd,
1384 proto, oif,
1385 dst_ip, dst_port,
1386 src_ip, src_port, &ucred_lookup,
1387#ifdef __FreeBSD__
1388 &ucred_cache, args->inp);
1389 if (v == 4 /* O_UID */)
1390 key = ucred_cache->cr_uid;
1391 else if (v == 5 /* O_JAIL */)
1392 key = ucred_cache->cr_prison->pr_id;
1393#else /* !__FreeBSD__ */
1394 (void *)&ucred_cache,
1395 (struct inpcb *)args->m);
1396 if (v ==4 /* O_UID */)
1397 key = ucred_cache.uid;
1398 else if (v == 5 /* O_JAIL */)
1399 key = ucred_cache.xid;
1400#endif /* !__FreeBSD__ */
1401 key = htonl(key);
1402 } else
1403 break;
1404 }
1405 match = ipfw_lookup_table(chain,
1406 cmd->arg1, key, &v);
1407 if (!match)
1408 break;
1409 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1410 match =
1411 ((ipfw_insn_u32 *)cmd)->d[0] == v;
1412 else
1413 tablearg = v;
1414 }
1415 break;
1416
1417 case O_IP_SRC_MASK:
1418 case O_IP_DST_MASK:
1419 if (is_ipv4) {
1420 uint32_t a =
1421 (cmd->opcode == O_IP_DST_MASK) ?
1422 dst_ip.s_addr : src_ip.s_addr;
1423 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1424 int i = cmdlen-1;
1425
1426 for (; !match && i>0; i-= 2, p+= 2)
1427 match = (p[0] == (a & p[1]));
1428 }
1429 break;
1430
1431 case O_IP_SRC_ME:
1432 if (is_ipv4) {
1433 struct ifnet *tif;
1434
1435 INADDR_TO_IFP(src_ip, tif);
1436 match = (tif != NULL);
1437 break;
1438 }
1439#ifdef INET6
1440 /* FALLTHROUGH */
1441 case O_IP6_SRC_ME:
1442 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
1443#endif
1444 break;
1445
1446 case O_IP_DST_SET:
1447 case O_IP_SRC_SET:
1448 if (is_ipv4) {
1449 u_int32_t *d = (u_int32_t *)(cmd+1);
1450 u_int32_t addr =
1451 cmd->opcode == O_IP_DST_SET ?
1452 args->f_id.dst_ip :
1453 args->f_id.src_ip;
1454
1455 if (addr < d[0])
1456 break;
1457 addr -= d[0]; /* subtract base */
1458 match = (addr < cmd->arg1) &&
1459 ( d[ 1 + (addr>>5)] &
1460 (1<<(addr & 0x1f)) );
1461 }
1462 break;
1463
1464 case O_IP_DST:
1465 match = is_ipv4 &&
1466 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1467 dst_ip.s_addr);
1468 break;
1469
1470 case O_IP_DST_ME:
1471 if (is_ipv4) {
1472 struct ifnet *tif;
1473
1474 INADDR_TO_IFP(dst_ip, tif);
1475 match = (tif != NULL);
1476 break;
1477 }
1478#ifdef INET6
1479 /* FALLTHROUGH */
1480 case O_IP6_DST_ME:
1481 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
1482#endif
1483 break;
1484
1485
1486 case O_IP_SRCPORT:
1487 case O_IP_DSTPORT:
1488 /*
1489 * offset == 0 && proto != 0 is enough
1490 * to guarantee that we have a
1491 * packet with port info.
1492 */
1493 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1494 && offset == 0) {
1495 u_int16_t x =
1496 (cmd->opcode == O_IP_SRCPORT) ?
1497 src_port : dst_port ;
1498 u_int16_t *p =
1499 ((ipfw_insn_u16 *)cmd)->ports;
1500 int i;
1501
1502 for (i = cmdlen - 1; !match && i>0;
1503 i--, p += 2)
1504 match = (x>=p[0] && x<=p[1]);
1505 }
1506 break;
1507
1508 case O_ICMPTYPE:
1509 match = (offset == 0 && proto==IPPROTO_ICMP &&
1510 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1511 break;
1512
1513#ifdef INET6
1514 case O_ICMP6TYPE:
1515 match = is_ipv6 && offset == 0 &&
1516 proto==IPPROTO_ICMPV6 &&
1517 icmp6type_match(
1518 ICMP6(ulp)->icmp6_type,
1519 (ipfw_insn_u32 *)cmd);
1520 break;
1521#endif /* INET6 */
1522
1523 case O_IPOPT:
1524 match = (is_ipv4 &&
1525 ipopts_match(ip, cmd) );
1526 break;
1527
1528 case O_IPVER:
1529 match = (is_ipv4 &&
1530 cmd->arg1 == ip->ip_v);
1531 break;
1532
1533 case O_IPID:
1534 case O_IPLEN:
1535 case O_IPTTL:
1536 if (is_ipv4) { /* only for IP packets */
1537 uint16_t x;
1538 uint16_t *p;
1539 int i;
1540
1541 if (cmd->opcode == O_IPLEN)
1542 x = iplen;
1543 else if (cmd->opcode == O_IPTTL)
1544 x = ip->ip_ttl;
1545 else /* must be IPID */
1546 x = ntohs(ip->ip_id);
1547 if (cmdlen == 1) {
1548 match = (cmd->arg1 == x);
1549 break;
1550 }
1551 /* otherwise we have ranges */
1552 p = ((ipfw_insn_u16 *)cmd)->ports;
1553 i = cmdlen - 1;
1554 for (; !match && i>0; i--, p += 2)
1555 match = (x >= p[0] && x <= p[1]);
1556 }
1557 break;
1558
1559 case O_IPPRECEDENCE:
1560 match = (is_ipv4 &&
1561 (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1562 break;
1563
1564 case O_IPTOS:
1565 match = (is_ipv4 &&
1566 flags_match(cmd, ip->ip_tos));
1567 break;
1568
1569 case O_TCPDATALEN:
1570 if (proto == IPPROTO_TCP && offset == 0) {
1571 struct tcphdr *tcp;
1572 uint16_t x;
1573 uint16_t *p;
1574 int i;
1575
1576 tcp = TCP(ulp);
1577 x = iplen -
1578 ((ip->ip_hl + tcp->th_off) << 2);
1579 if (cmdlen == 1) {
1580 match = (cmd->arg1 == x);
1581 break;
1582 }
1583 /* otherwise we have ranges */
1584 p = ((ipfw_insn_u16 *)cmd)->ports;
1585 i = cmdlen - 1;
1586 for (; !match && i>0; i--, p += 2)
1587 match = (x >= p[0] && x <= p[1]);
1588 }
1589 break;
1590
1591 case O_TCPFLAGS:
1592 match = (proto == IPPROTO_TCP && offset == 0 &&
1593 flags_match(cmd, TCP(ulp)->th_flags));
1594 break;
1595
1596 case O_TCPOPTS:
1597 match = (proto == IPPROTO_TCP && offset == 0 &&
1598 tcpopts_match(TCP(ulp), cmd));
1599 break;
1600
1601 case O_TCPSEQ:
1602 match = (proto == IPPROTO_TCP && offset == 0 &&
1603 ((ipfw_insn_u32 *)cmd)->d[0] ==
1604 TCP(ulp)->th_seq);
1605 break;
1606
1607 case O_TCPACK:
1608 match = (proto == IPPROTO_TCP && offset == 0 &&
1609 ((ipfw_insn_u32 *)cmd)->d[0] ==
1610 TCP(ulp)->th_ack);
1611 break;
1612
1613 case O_TCPWIN:
1614 match = (proto == IPPROTO_TCP && offset == 0 &&
1615 cmd->arg1 == TCP(ulp)->th_win);
1616 break;
1617
1618 case O_ESTAB:
1619 /* reject packets which have SYN only */
1620 /* XXX should i also check for TH_ACK ? */
1621 match = (proto == IPPROTO_TCP && offset == 0 &&
1622 (TCP(ulp)->th_flags &
1623 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1624 break;
1625
1626 case O_ALTQ: {
1627 struct pf_mtag *at;
1628 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1629
1630 match = 1;
1631 at = pf_find_mtag(m);
1632 if (at != NULL && at->qid != 0)
1633 break;
1634 at = pf_get_mtag(m);
1635 if (at == NULL) {
1636 /*
1637 * Let the packet fall back to the
1638 * default ALTQ.
1639 */
1640 break;
1641 }
1642 at->qid = altq->qid;
1643 if (is_ipv4)
1644 at->af = AF_INET;
1645 else
1646 at->af = AF_LINK;
1647 at->hdr = ip;
1648 break;
1649 }
1650
1651 case O_LOG:
1652 ipfw_log(f, hlen, args, m,
1653 oif, offset, tablearg, ip);
1654 match = 1;
1655 break;
1656
1657 case O_PROB:
1658 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1659 break;
1660
1661 case O_VERREVPATH:
1662 /* Outgoing packets automatically pass/match */
1663 match = ((oif != NULL) ||
1664 (m->m_pkthdr.rcvif == NULL) ||
1665 (
1666#ifdef INET6
1667 is_ipv6 ?
1668 verify_path6(&(args->f_id.src_ip6),
1669 m->m_pkthdr.rcvif) :
1670#endif
1671 verify_path(src_ip, m->m_pkthdr.rcvif,
1672 args->f_id.fib)));
1673 break;
1674
1675 case O_VERSRCREACH:
1676 /* Outgoing packets automatically pass/match */
1677 match = (hlen > 0 && ((oif != NULL) ||
1678#ifdef INET6
1679 is_ipv6 ?
1680 verify_path6(&(args->f_id.src_ip6),
1681 NULL) :
1682#endif
1683 verify_path(src_ip, NULL, args->f_id.fib)));
1684 break;
1685
1686 case O_ANTISPOOF:
1687 /* Outgoing packets automatically pass/match */
1688 if (oif == NULL && hlen > 0 &&
1689 ( (is_ipv4 && in_localaddr(src_ip))
1690#ifdef INET6
1691 || (is_ipv6 &&
1692 in6_localaddr(&(args->f_id.src_ip6)))
1693#endif
1694 ))
1695 match =
1696#ifdef INET6
1697 is_ipv6 ? verify_path6(
1698 &(args->f_id.src_ip6),
1699 m->m_pkthdr.rcvif) :
1700#endif
1701 verify_path(src_ip,
1702 m->m_pkthdr.rcvif,
1703 args->f_id.fib);
1704 else
1705 match = 1;
1706 break;
1707
1708 case O_IPSEC:
1709#ifdef IPSEC
1710 match = (m_tag_find(m,
1711 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1712#endif
1713 /* otherwise no match */
1714 break;
1715
1716#ifdef INET6
1717 case O_IP6_SRC:
1718 match = is_ipv6 &&
1719 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1720 &((ipfw_insn_ip6 *)cmd)->addr6);
1721 break;
1722
1723 case O_IP6_DST:
1724 match = is_ipv6 &&
1725 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1726 &((ipfw_insn_ip6 *)cmd)->addr6);
1727 break;
1728 case O_IP6_SRC_MASK:
1729 case O_IP6_DST_MASK:
1730 if (is_ipv6) {
1731 int i = cmdlen - 1;
1732 struct in6_addr p;
1733 struct in6_addr *d =
1734 &((ipfw_insn_ip6 *)cmd)->addr6;
1735
1736 for (; !match && i > 0; d += 2,
1737 i -= F_INSN_SIZE(struct in6_addr)
1738 * 2) {
1739 p = (cmd->opcode ==
1740 O_IP6_SRC_MASK) ?
1741 args->f_id.src_ip6:
1742 args->f_id.dst_ip6;
1743 APPLY_MASK(&p, &d[1]);
1744 match =
1745 IN6_ARE_ADDR_EQUAL(&d[0],
1746 &p);
1747 }
1748 }
1749 break;
1750
1751 case O_FLOW6ID:
1752 match = is_ipv6 &&
1753 flow6id_match(args->f_id.flow_id6,
1754 (ipfw_insn_u32 *) cmd);
1755 break;
1756
1757 case O_EXT_HDR:
1758 match = is_ipv6 &&
1759 (ext_hd & ((ipfw_insn *) cmd)->arg1);
1760 break;
1761
1762 case O_IP6:
1763 match = is_ipv6;
1764 break;
1765#endif
1766
1767 case O_IP4:
1768 match = is_ipv4;
1769 break;
1770
1771 case O_TAG: {
1772 struct m_tag *mtag;
1773 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1774 tablearg : cmd->arg1;
1775
1776 /* Packet is already tagged with this tag? */
1777 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1778
1779 /* We have `untag' action when F_NOT flag is
1780 * present. And we must remove this mtag from
1781 * mbuf and reset `match' to zero (`match' will
1782 * be inversed later).
1783 * Otherwise we should allocate new mtag and
1784 * push it into mbuf.
1785 */
1786 if (cmd->len & F_NOT) { /* `untag' action */
1787 if (mtag != NULL)
1788 m_tag_delete(m, mtag);
1789 match = 0;
1790 } else if (mtag == NULL) {
1791 if ((mtag = m_tag_alloc(MTAG_IPFW,
1792 tag, 0, M_NOWAIT)) != NULL)
1793 m_tag_prepend(m, mtag);
1794 match = 1;
1795 }
1796 break;
1797 }
1798
1799 case O_FIB: /* try match the specified fib */
1800 if (args->f_id.fib == cmd->arg1)
1801 match = 1;
1802 break;
1803
1804 case O_SOCKARG: {
1805 struct inpcb *inp = args->inp;
1806 struct inpcbinfo *pi;
1807
1808 if (is_ipv6) /* XXX can we remove this ? */
1809 break;
1810
1811 if (proto == IPPROTO_TCP)
1812 pi = &V_tcbinfo;
1813 else if (proto == IPPROTO_UDP)
1814 pi = &V_udbinfo;
1815 else
1816 break;
1817
1818 /* For incomming packet, lookup up the
1819 inpcb using the src/dest ip/port tuple */
1820 if (inp == NULL) {
1821 INP_INFO_RLOCK(pi);
1822 inp = in_pcblookup_hash(pi,
1823 src_ip, htons(src_port),
1824 dst_ip, htons(dst_port),
1825 0, NULL);
1826 INP_INFO_RUNLOCK(pi);
1827 }
1828
1829 if (inp && inp->inp_socket) {
1830 tablearg = inp->inp_socket->so_user_cookie;
1831 if (tablearg)
1832 match = 1;
1833 }
1834 break;
1835 }
1836
1837 case O_TAGGED: {
1838 struct m_tag *mtag;
1839 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1840 tablearg : cmd->arg1;
1841
1842 if (cmdlen == 1) {
1843 match = m_tag_locate(m, MTAG_IPFW,
1844 tag, NULL) != NULL;
1845 break;
1846 }
1847
1848 /* we have ranges */
1849 for (mtag = m_tag_first(m);
1850 mtag != NULL && !match;
1851 mtag = m_tag_next(m, mtag)) {
1852 uint16_t *p;
1853 int i;
1854
1855 if (mtag->m_tag_cookie != MTAG_IPFW)
1856 continue;
1857
1858 p = ((ipfw_insn_u16 *)cmd)->ports;
1859 i = cmdlen - 1;
1860 for(; !match && i > 0; i--, p += 2)
1861 match =
1862 mtag->m_tag_id >= p[0] &&
1863 mtag->m_tag_id <= p[1];
1864 }
1865 break;
1866 }
1867
1868 /*
1869 * The second set of opcodes represents 'actions',
1870 * i.e. the terminal part of a rule once the packet
1871 * matches all previous patterns.
1872 * Typically there is only one action for each rule,
1873 * and the opcode is stored at the end of the rule
1874 * (but there are exceptions -- see below).
1875 *
1876 * In general, here we set retval and terminate the
1877 * outer loop (would be a 'break 3' in some language,
1878 * but we need to set l=0, done=1)
1879 *
1880 * Exceptions:
1881 * O_COUNT and O_SKIPTO actions:
1882 * instead of terminating, we jump to the next rule
1883 * (setting l=0), or to the SKIPTO target (setting
1884 * f/f_len, cmd and l as needed), respectively.
1885 *
1886 * O_TAG, O_LOG and O_ALTQ action parameters:
1887 * perform some action and set match = 1;
1888 *
1889 * O_LIMIT and O_KEEP_STATE: these opcodes are
1890 * not real 'actions', and are stored right
1891 * before the 'action' part of the rule.
1892 * These opcodes try to install an entry in the
1893 * state tables; if successful, we continue with
1894 * the next opcode (match=1; break;), otherwise
1895 * the packet must be dropped (set retval,
1896 * break loops with l=0, done=1)
1897 *
1898 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1899 * cause a lookup of the state table, and a jump
1900 * to the 'action' part of the parent rule
1901 * if an entry is found, or
1902 * (CHECK_STATE only) a jump to the next rule if
1903 * the entry is not found.
1904 * The result of the lookup is cached so that
1905 * further instances of these opcodes become NOPs.
1906 * The jump to the next rule is done by setting
1907 * l=0, cmdlen=0.
1908 */
1909 case O_LIMIT:
1910 case O_KEEP_STATE:
1911 if (ipfw_install_state(f,
1912 (ipfw_insn_limit *)cmd, args, tablearg)) {
1913 /* error or limit violation */
1914 retval = IP_FW_DENY;
1915 l = 0; /* exit inner loop */
1916 done = 1; /* exit outer loop */
1917 }
1918 match = 1;
1919 break;
1920
1921 case O_PROBE_STATE:
1922 case O_CHECK_STATE:
1923 /*
1924 * dynamic rules are checked at the first
1925 * keep-state or check-state occurrence,
1926 * with the result being stored in dyn_dir.
1927 * The compiler introduces a PROBE_STATE
1928 * instruction for us when we have a
1929 * KEEP_STATE (because PROBE_STATE needs
1930 * to be run first).
1931 */
1932 if (dyn_dir == MATCH_UNKNOWN &&
1933 (q = ipfw_lookup_dyn_rule(&args->f_id,
1934 &dyn_dir, proto == IPPROTO_TCP ?
1935 TCP(ulp) : NULL))
1936 != NULL) {
1937 /*
1938 * Found dynamic entry, update stats
1939 * and jump to the 'action' part of
1940 * the parent rule by setting
1941 * f, cmd, l and clearing cmdlen.
1942 */
1943 q->pcnt++;
1944 q->bcnt += pktlen;
1945 /* XXX we would like to have f_pos
1946 * readily accessible in the dynamic
1947 * rule, instead of having to
1948 * lookup q->rule.
1949 */
1950 f = q->rule;
1951 f_pos = ipfw_find_rule(chain,
1952 f->rulenum, f->id);
1953 cmd = ACTION_PTR(f);
1954 l = f->cmd_len - f->act_ofs;
1955 ipfw_dyn_unlock();
1956 cmdlen = 0;
1957 match = 1;
1958 break;
1959 }
1960 /*
1961 * Dynamic entry not found. If CHECK_STATE,
1962 * skip to next rule, if PROBE_STATE just
1963 * ignore and continue with next opcode.
1964 */
1965 if (cmd->opcode == O_CHECK_STATE)
1966 l = 0; /* exit inner loop */
1967 match = 1;
1968 break;
1969
1970 case O_ACCEPT:
1971 retval = 0; /* accept */
1972 l = 0; /* exit inner loop */
1973 done = 1; /* exit outer loop */
1974 break;
1975
1976 case O_PIPE:
1977 case O_QUEUE:
1978 set_match(args, f_pos, chain);
1979 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
1980 tablearg : cmd->arg1;
1981 if (cmd->opcode == O_PIPE)
1982 args->rule.info |= IPFW_IS_PIPE;
1983 if (V_fw_one_pass)
1984 args->rule.info |= IPFW_ONEPASS;
1985 retval = IP_FW_DUMMYNET;
1986 l = 0; /* exit inner loop */
1987 done = 1; /* exit outer loop */
1988 break;
1989
1990 case O_DIVERT:
1991 case O_TEE:
1992 if (args->eh) /* not on layer 2 */
1993 break;
1994 /* otherwise this is terminal */
1995 l = 0; /* exit inner loop */
1996 done = 1; /* exit outer loop */
1997 retval = (cmd->opcode == O_DIVERT) ?
1998 IP_FW_DIVERT : IP_FW_TEE;
1999 set_match(args, f_pos, chain);
2000 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2001 tablearg : cmd->arg1;
2002 break;
2003
2004 case O_COUNT:
2005 f->pcnt++; /* update stats */
2006 f->bcnt += pktlen;
2007 f->timestamp = time_uptime;
2008 l = 0; /* exit inner loop */
2009 break;
2010
2011 case O_SKIPTO:
2012 f->pcnt++; /* update stats */
2013 f->bcnt += pktlen;
2014 f->timestamp = time_uptime;
2015 /* If possible use cached f_pos (in f->next_rule),
2016 * whose version is written in f->next_rule
2017 * (horrible hacks to avoid changing the ABI).
2018 */
2019 if (cmd->arg1 != IP_FW_TABLEARG &&
2020 (uintptr_t)f->x_next == chain->id) {
2021 f_pos = (uintptr_t)f->next_rule;
2022 } else {
2023 int i = (cmd->arg1 == IP_FW_TABLEARG) ?
2024 tablearg : cmd->arg1;
2025 /* make sure we do not jump backward */
2026 if (i <= f->rulenum)
2027 i = f->rulenum + 1;
2028 f_pos = ipfw_find_rule(chain, i, 0);
2029 /* update the cache */
2030 if (cmd->arg1 != IP_FW_TABLEARG) {
2031 f->next_rule =
2032 (void *)(uintptr_t)f_pos;
2033 f->x_next =
2034 (void *)(uintptr_t)chain->id;
2035 }
2036 }
2037 /*
2038 * Skip disabled rules, and re-enter
2039 * the inner loop with the correct
2040 * f_pos, f, l and cmd.
2041 * Also clear cmdlen and skip_or
2042 */
2043 for (; f_pos < chain->n_rules - 1 &&
2044 (V_set_disable &
2045 (1 << chain->map[f_pos]->set));
2046 f_pos++)
2047 ;
2048 /* Re-enter the inner loop at the skipto rule. */
2049 f = chain->map[f_pos];
2050 l = f->cmd_len;
2051 cmd = f->cmd;
2052 match = 1;
2053 cmdlen = 0;
2054 skip_or = 0;
2055 continue;
2056 break; /* not reached */
2057
2058 case O_REJECT:
2059 /*
2060 * Drop the packet and send a reject notice
2061 * if the packet is not ICMP (or is an ICMP
2062 * query), and it is not multicast/broadcast.
2063 */
2064 if (hlen > 0 && is_ipv4 && offset == 0 &&
2065 (proto != IPPROTO_ICMP ||
2066 is_icmp_query(ICMP(ulp))) &&
2067 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2068 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2069 send_reject(args, cmd->arg1, iplen, ip);
2070 m = args->m;
2071 }
2072 /* FALLTHROUGH */
2073#ifdef INET6
2074 case O_UNREACH6:
2075 if (hlen > 0 && is_ipv6 &&
2076 ((offset & IP6F_OFF_MASK) == 0) &&
2077 (proto != IPPROTO_ICMPV6 ||
2078 (is_icmp6_query(icmp6_type) == 1)) &&
2079 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2080 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2081 send_reject6(
2082 args, cmd->arg1, hlen,
2083 (struct ip6_hdr *)ip);
2084 m = args->m;
2085 }
2086 /* FALLTHROUGH */
2087#endif
2088 case O_DENY:
2089 retval = IP_FW_DENY;
2090 l = 0; /* exit inner loop */
2091 done = 1; /* exit outer loop */
2092 break;
2093
2094 case O_FORWARD_IP:
2095 if (args->eh) /* not valid on layer2 pkts */
2096 break;
2097 if (!q || dyn_dir == MATCH_FORWARD) {
2098 struct sockaddr_in *sa;
2099 sa = &(((ipfw_insn_sa *)cmd)->sa);
2100 if (sa->sin_addr.s_addr == INADDR_ANY) {
2101 bcopy(sa, &args->hopstore,
2102 sizeof(*sa));
2103 args->hopstore.sin_addr.s_addr =
2104 htonl(tablearg);
2105 args->next_hop = &args->hopstore;
2106 } else {
2107 args->next_hop = sa;
2108 }
2109 }
2110 retval = IP_FW_PASS;
2111 l = 0; /* exit inner loop */
2112 done = 1; /* exit outer loop */
2113 break;
2114
2115 case O_NETGRAPH:
2116 case O_NGTEE:
2117 set_match(args, f_pos, chain);
2118 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2119 tablearg : cmd->arg1;
2120 if (V_fw_one_pass)
2121 args->rule.info |= IPFW_ONEPASS;
2122 retval = (cmd->opcode == O_NETGRAPH) ?
2123 IP_FW_NETGRAPH : IP_FW_NGTEE;
2124 l = 0; /* exit inner loop */
2125 done = 1; /* exit outer loop */
2126 break;
2127
2128 case O_SETFIB:
2129 f->pcnt++; /* update stats */
2130 f->bcnt += pktlen;
2131 f->timestamp = time_uptime;
2132 M_SETFIB(m, cmd->arg1);
2133 args->f_id.fib = cmd->arg1;
2134 l = 0; /* exit inner loop */
2135 break;
2136
2137 case O_NAT:
2138 if (!IPFW_NAT_LOADED) {
2139 retval = IP_FW_DENY;
2140 } else {
2141 struct cfg_nat *t;
2142 int nat_id;
2143
2144 set_match(args, f_pos, chain);
2145 t = ((ipfw_insn_nat *)cmd)->nat;
2146 if (t == NULL) {
2147 nat_id = (cmd->arg1 == IP_FW_TABLEARG) ?
2148 tablearg : cmd->arg1;
2149 t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2150
2151 if (t == NULL) {
2152 retval = IP_FW_DENY;
2153 l = 0; /* exit inner loop */
2154 done = 1; /* exit outer loop */
2155 break;
2156 }
2157 if (cmd->arg1 != IP_FW_TABLEARG)
2158 ((ipfw_insn_nat *)cmd)->nat = t;
2159 }
2160 retval = ipfw_nat_ptr(args, t, m);
2161 }
2162 l = 0; /* exit inner loop */
2163 done = 1; /* exit outer loop */
2164 break;
2165
2166 case O_REASS: {
2167 int ip_off;
2168
2169 f->pcnt++;
2170 f->bcnt += pktlen;
2171 l = 0; /* in any case exit inner loop */
2172 ip_off = ntohs(ip->ip_off);
2173
2174 /* if not fragmented, go to next rule */
2175 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2176 break;
2177 /*
2178 * ip_reass() expects len & off in host
2179 * byte order.
2180 */
2181 SET_HOST_IPLEN(ip);
2182
2183 args->m = m = ip_reass(m);
2184
2185 /*
2186 * do IP header checksum fixup.
2187 */
2188 if (m == NULL) { /* fragment got swallowed */
2189 retval = IP_FW_DENY;
2190 } else { /* good, packet complete */
2191 int hlen;
2192
2193 ip = mtod(m, struct ip *);
2194 hlen = ip->ip_hl << 2;
2195 SET_NET_IPLEN(ip);
2196 ip->ip_sum = 0;
2197 if (hlen == sizeof(struct ip))
2198 ip->ip_sum = in_cksum_hdr(ip);
2199 else
2200 ip->ip_sum = in_cksum(m, hlen);
2201 retval = IP_FW_REASS;
2202 set_match(args, f_pos, chain);
2203 }
2204 done = 1; /* exit outer loop */
2205 break;
2206 }
2207
2208 default:
2209 panic("-- unknown opcode %d\n", cmd->opcode);
2210 } /* end of switch() on opcodes */
2211 /*
2212 * if we get here with l=0, then match is irrelevant.
2213 */
2214
2215 if (cmd->len & F_NOT)
2216 match = !match;
2217
2218 if (match) {
2219 if (cmd->len & F_OR)
2220 skip_or = 1;
2221 } else {
2222 if (!(cmd->len & F_OR)) /* not an OR block, */
2223 break; /* try next rule */
2224 }
2225
2226 } /* end of inner loop, scan opcodes */
2227
2228 if (done)
2229 break;
2230
2231/* next_rule:; */ /* try next rule */
2232
2233 } /* end of outer for, scan rules */
2234
2235 if (done) {
2236 struct ip_fw *rule = chain->map[f_pos];
2237 /* Update statistics */
2238 rule->pcnt++;
2239 rule->bcnt += pktlen;
2240 rule->timestamp = time_uptime;
2241 } else {
2242 retval = IP_FW_DENY;
2243 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2244 }
2245 IPFW_RUNLOCK(chain);
2246#ifdef __FreeBSD__
2247 if (ucred_cache != NULL)
2248 crfree(ucred_cache);
2249#endif
2250 return (retval);
2251
2252pullup_failed:
2253 if (V_fw_verbose)
2254 printf("ipfw: pullup failed\n");
2255 return (IP_FW_DENY);
2256}
2257
2258/*
2259 * Module and VNET glue
2260 */
2261
2262/*
2263 * Stuff that must be initialised only on boot or module load
2264 */
2265static int
2266ipfw_init(void)
2267{
2268 int error = 0;
2269
2270 ipfw_dyn_attach();
2271 /*
2272 * Only print out this stuff the first time around,
2273 * when called from the sysinit code.
2274 */
2275 printf("ipfw2 "
2276#ifdef INET6
2277 "(+ipv6) "
2278#endif
2279 "initialized, divert %s, nat %s, "
2280 "rule-based forwarding "
2281#ifdef IPFIREWALL_FORWARD
2282 "enabled, "
2283#else
2284 "disabled, "
2285#endif
2286 "default to %s, logging ",
2287#ifdef IPDIVERT
2288 "enabled",
2289#else
2290 "loadable",
2291#endif
2292#ifdef IPFIREWALL_NAT
2293 "enabled",
2294#else
2295 "loadable",
2296#endif
2297 default_to_accept ? "accept" : "deny");
2298
2299 /*
2300 * Note: V_xxx variables can be accessed here but the vnet specific
2301 * initializer may not have been called yet for the VIMAGE case.
2302 * Tuneables will have been processed. We will print out values for
2303 * the default vnet.
2304 * XXX This should all be rationalized AFTER 8.0
2305 */
2306 if (V_fw_verbose == 0)
2307 printf("disabled\n");
2308 else if (V_verbose_limit == 0)
2309 printf("unlimited\n");
2310 else
2311 printf("limited to %d packets/entry by default\n",
2312 V_verbose_limit);
2313
2314 ipfw_log_bpf(1); /* init */
2315 return (error);
2316}
2317
2318/*
2319 * Called for the removal of the last instance only on module unload.
2320 */
2321static void
2322ipfw_destroy(void)
2323{
2324
2325 ipfw_log_bpf(0); /* uninit */
2326 ipfw_dyn_detach();
2327 printf("IP firewall unloaded\n");
2328}
2329
2330/*
2331 * Stuff that must be initialized for every instance
2332 * (including the first of course).
2333 */
2334static int
2335vnet_ipfw_init(const void *unused)
2336{
2337 int error;
2338 struct ip_fw *rule = NULL;
2339 struct ip_fw_chain *chain;
2340
2341 chain = &V_layer3_chain;
2342
2343 /* First set up some values that are compile time options */
2344 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
2345 V_fw_deny_unknown_exthdrs = 1;
2346#ifdef IPFIREWALL_VERBOSE
2347 V_fw_verbose = 1;
2348#endif
2349#ifdef IPFIREWALL_VERBOSE_LIMIT
2350 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2351#endif
2352#ifdef IPFIREWALL_NAT
2353 LIST_INIT(&chain->nat);
2354#endif
2355
2356 /* insert the default rule and create the initial map */
2357 chain->n_rules = 1;
2358 chain->static_len = sizeof(struct ip_fw);
2359 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_NOWAIT | M_ZERO);
2360 if (chain->map)
2361 rule = malloc(chain->static_len, M_IPFW, M_NOWAIT | M_ZERO);
2362 if (rule == NULL) {
2363 if (chain->map)
2364 free(chain->map, M_IPFW);
2365 printf("ipfw2: ENOSPC initializing default rule "
2366 "(support disabled)\n");
2367 return (ENOSPC);
2368 }
2369 error = ipfw_init_tables(chain);
2370 if (error) {
2371 panic("init_tables"); /* XXX Marko fix this ! */
2372 }
2373
2374 /* fill and insert the default rule */
2375 rule->act_ofs = 0;
2376 rule->rulenum = IPFW_DEFAULT_RULE;
2377 rule->cmd_len = 1;
2378 rule->set = RESVD_SET;
2379 rule->cmd[0].len = 1;
2380 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2381 chain->rules = chain->default_rule = chain->map[0] = rule;
2382 chain->id = rule->id = 1;
2383
2384 IPFW_LOCK_INIT(chain);
2385 ipfw_dyn_init();
2386
2387 /* First set up some values that are compile time options */
2388 V_ipfw_vnet_ready = 1; /* Open for business */
2389
2390 /*
2391 * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr)
2392 * and pfil hooks for ipv4 and ipv6. Even if the latter two fail
2393 * we still keep the module alive because the sockopt and
2394 * layer2 paths are still useful.
2395 * ipfw[6]_hook return 0 on success, ENOENT on failure,
2396 * so we can ignore the exact return value and just set a flag.
2397 *
2398 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2399 * changes in the underlying (per-vnet) variables trigger
2400 * immediate hook()/unhook() calls.
2401 * In layer2 we have the same behaviour, except that V_ether_ipfw
2402 * is checked on each packet because there are no pfil hooks.
2403 */
2404 V_ip_fw_ctl_ptr = ipfw_ctl;
2405 V_ip_fw_chk_ptr = ipfw_chk;
2406 error = ipfw_attach_hooks(1);
2407 return (error);
2408}
2409
2410/*
2411 * Called for the removal of each instance.
2412 */
2413static int
2414vnet_ipfw_uninit(const void *unused)
2415{
2416 struct ip_fw *reap, *rule;
2417 struct ip_fw_chain *chain = &V_layer3_chain;
2418 int i;
2419
2420 V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2421 /*
2422 * disconnect from ipv4, ipv6, layer2 and sockopt.
2423 * Then grab, release and grab again the WLOCK so we make
2424 * sure the update is propagated and nobody will be in.
2425 */
2426 (void)ipfw_attach_hooks(0 /* detach */);
2427 V_ip_fw_chk_ptr = NULL;
2428 V_ip_fw_ctl_ptr = NULL;
2429 IPFW_UH_WLOCK(chain);
2430 IPFW_UH_WUNLOCK(chain);
2431 IPFW_UH_WLOCK(chain);
2432
2433 IPFW_WLOCK(chain);
2434 IPFW_WUNLOCK(chain);
2435 IPFW_WLOCK(chain);
2436
2437 ipfw_dyn_uninit(0); /* run the callout_drain */
2438 ipfw_destroy_tables(chain);
2439 reap = NULL;
2440 for (i = 0; i < chain->n_rules; i++) {
2441 rule = chain->map[i];
2442 rule->x_next = reap;
2443 reap = rule;
2444 }
2445 if (chain->map)
2446 free(chain->map, M_IPFW);
2447 IPFW_WUNLOCK(chain);
2448 IPFW_UH_WUNLOCK(chain);
2449 if (reap != NULL)
2450 ipfw_reap_rules(reap);
2451 IPFW_LOCK_DESTROY(chain);
2452 ipfw_dyn_uninit(1); /* free the remaining parts */
2453 return 0;
2454}
2455
2456/*
2457 * Module event handler.
2458 * In general we have the choice of handling most of these events by the
2459 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2460 * use the SYSINIT handlers as they are more capable of expressing the
2461 * flow of control during module and vnet operations, so this is just
2462 * a skeleton. Note there is no SYSINIT equivalent of the module
2463 * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2464 */
2465static int
2466ipfw_modevent(module_t mod, int type, void *unused)
2467{
2468 int err = 0;
2469
2470 switch (type) {
2471 case MOD_LOAD:
2472 /* Called once at module load or
2473 * system boot if compiled in. */
2474 break;
2475 case MOD_QUIESCE:
2476 /* Called before unload. May veto unloading. */
2477 break;
2478 case MOD_UNLOAD:
2479 /* Called during unload. */
2480 break;
2481 case MOD_SHUTDOWN:
2482 /* Called during system shutdown. */
2483 break;
2484 default:
2485 err = EOPNOTSUPP;
2486 break;
2487 }
2488 return err;
2489}
2490
2491static moduledata_t ipfwmod = {
2492 "ipfw",
2493 ipfw_modevent,
2494 0
2495};
2496
2497/* Define startup order. */
2498#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN
2499#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */
2500#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2501#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2502
2503DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2504MODULE_VERSION(ipfw, 2);
2505/* should declare some dependencies here */
2506
2507/*
2508 * Starting up. Done in order after ipfwmod() has been called.
2509 * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2510 */
2511SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2512 ipfw_init, NULL);
2513VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2514 vnet_ipfw_init, NULL);
2515
2516/*
2517 * Closing up shop. These are done in REVERSE ORDER, but still
2518 * after ipfwmod() has been called. Not called on reboot.
2519 * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2520 * or when the module is unloaded.
2521 */
2522SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2523 ipfw_destroy, NULL);
2524VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2525 vnet_ipfw_uninit, NULL);
2526/* end of file */
| 107#define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs)
108
109#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
110static int default_to_accept = 1;
111#else
112static int default_to_accept;
113#endif
114
115VNET_DEFINE(int, autoinc_step);
116
117/*
118 * Each rule belongs to one of 32 different sets (0..31).
119 * The variable set_disable contains one bit per set.
120 * If the bit is set, all rules in the corresponding set
121 * are disabled. Set RESVD_SET(31) is reserved for the default rule
122 * and rules that are not deleted by the flush command,
123 * and CANNOT be disabled.
124 * Rules in set RESVD_SET can only be deleted individually.
125 */
126VNET_DEFINE(u_int32_t, set_disable);
127#define V_set_disable VNET(set_disable)
128
129VNET_DEFINE(int, fw_verbose);
130/* counter for ipfw_log(NULL...) */
131VNET_DEFINE(u_int64_t, norule_counter);
132VNET_DEFINE(int, verbose_limit);
133
134/* layer3_chain contains the list of rules for layer 3 */
135VNET_DEFINE(struct ip_fw_chain, layer3_chain);
136
137ipfw_nat_t *ipfw_nat_ptr = NULL;
138struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
139ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
140ipfw_nat_cfg_t *ipfw_nat_del_ptr;
141ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
142ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
143
144#ifdef SYSCTL_NODE
145uint32_t dummy_def = IPFW_DEFAULT_RULE;
146uint32_t dummy_tables_max = IPFW_TABLES_MAX;
147
148SYSBEGIN(f3)
149
150SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
151SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
152 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
153 "Only do a single pass through ipfw when using dummynet(4)");
154SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
155 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
156 "Rule number auto-increment step");
157SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose,
158 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
159 "Log matches to ipfw rules");
160SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
161 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
162 "Set upper limit of matches of ipfw rules logged");
163SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
164 &dummy_def, 0,
165 "The default/max possible rule number.");
166SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_RD,
167 &dummy_tables_max, 0,
168 "The maximum number of tables.");
169SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
170 &default_to_accept, 0,
171 "Make the default rule accept all packets.");
172TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept);
173SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count,
174 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
175 "Number of static rules");
176
177#ifdef INET6
178SYSCTL_DECL(_net_inet6_ip6);
179SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
180SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
181 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0,
182 "Deny packets with unknown IPv6 Extension Headers");
183#endif /* INET6 */
184
185SYSEND
186
187#endif /* SYSCTL_NODE */
188
189
190/*
191 * Some macros used in the various matching options.
192 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
193 * Other macros just cast void * into the appropriate type
194 */
195#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
196#define TCP(p) ((struct tcphdr *)(p))
197#define SCTP(p) ((struct sctphdr *)(p))
198#define UDP(p) ((struct udphdr *)(p))
199#define ICMP(p) ((struct icmphdr *)(p))
200#define ICMP6(p) ((struct icmp6_hdr *)(p))
201
202static __inline int
203icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
204{
205 int type = icmp->icmp_type;
206
207 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
208}
209
210#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
211 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
212
213static int
214is_icmp_query(struct icmphdr *icmp)
215{
216 int type = icmp->icmp_type;
217
218 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
219}
220#undef TT
221
222/*
223 * The following checks use two arrays of 8 or 16 bits to store the
224 * bits that we want set or clear, respectively. They are in the
225 * low and high half of cmd->arg1 or cmd->d[0].
226 *
227 * We scan options and store the bits we find set. We succeed if
228 *
229 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
230 *
231 * The code is sometimes optimized not to store additional variables.
232 */
233
234static int
235flags_match(ipfw_insn *cmd, u_int8_t bits)
236{
237 u_char want_clear;
238 bits = ~bits;
239
240 if ( ((cmd->arg1 & 0xff) & bits) != 0)
241 return 0; /* some bits we want set were clear */
242 want_clear = (cmd->arg1 >> 8) & 0xff;
243 if ( (want_clear & bits) != want_clear)
244 return 0; /* some bits we want clear were set */
245 return 1;
246}
247
248static int
249ipopts_match(struct ip *ip, ipfw_insn *cmd)
250{
251 int optlen, bits = 0;
252 u_char *cp = (u_char *)(ip + 1);
253 int x = (ip->ip_hl << 2) - sizeof (struct ip);
254
255 for (; x > 0; x -= optlen, cp += optlen) {
256 int opt = cp[IPOPT_OPTVAL];
257
258 if (opt == IPOPT_EOL)
259 break;
260 if (opt == IPOPT_NOP)
261 optlen = 1;
262 else {
263 optlen = cp[IPOPT_OLEN];
264 if (optlen <= 0 || optlen > x)
265 return 0; /* invalid or truncated */
266 }
267 switch (opt) {
268
269 default:
270 break;
271
272 case IPOPT_LSRR:
273 bits |= IP_FW_IPOPT_LSRR;
274 break;
275
276 case IPOPT_SSRR:
277 bits |= IP_FW_IPOPT_SSRR;
278 break;
279
280 case IPOPT_RR:
281 bits |= IP_FW_IPOPT_RR;
282 break;
283
284 case IPOPT_TS:
285 bits |= IP_FW_IPOPT_TS;
286 break;
287 }
288 }
289 return (flags_match(cmd, bits));
290}
291
292static int
293tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
294{
295 int optlen, bits = 0;
296 u_char *cp = (u_char *)(tcp + 1);
297 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
298
299 for (; x > 0; x -= optlen, cp += optlen) {
300 int opt = cp[0];
301 if (opt == TCPOPT_EOL)
302 break;
303 if (opt == TCPOPT_NOP)
304 optlen = 1;
305 else {
306 optlen = cp[1];
307 if (optlen <= 0)
308 break;
309 }
310
311 switch (opt) {
312
313 default:
314 break;
315
316 case TCPOPT_MAXSEG:
317 bits |= IP_FW_TCPOPT_MSS;
318 break;
319
320 case TCPOPT_WINDOW:
321 bits |= IP_FW_TCPOPT_WINDOW;
322 break;
323
324 case TCPOPT_SACK_PERMITTED:
325 case TCPOPT_SACK:
326 bits |= IP_FW_TCPOPT_SACK;
327 break;
328
329 case TCPOPT_TIMESTAMP:
330 bits |= IP_FW_TCPOPT_TS;
331 break;
332
333 }
334 }
335 return (flags_match(cmd, bits));
336}
337
338static int
339iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
340{
341 if (ifp == NULL) /* no iface with this packet, match fails */
342 return 0;
343 /* Check by name or by IP address */
344 if (cmd->name[0] != '\0') { /* match by name */
345 /* Check name */
346 if (cmd->p.glob) {
347 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
348 return(1);
349 } else {
350 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
351 return(1);
352 }
353 } else {
354#ifdef __FreeBSD__ /* and OSX too ? */
355 struct ifaddr *ia;
356
357 if_addr_rlock(ifp);
358 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
359 if (ia->ifa_addr->sa_family != AF_INET)
360 continue;
361 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
362 (ia->ifa_addr))->sin_addr.s_addr) {
363 if_addr_runlock(ifp);
364 return(1); /* match */
365 }
366 }
367 if_addr_runlock(ifp);
368#endif /* __FreeBSD__ */
369 }
370 return(0); /* no match, fail ... */
371}
372
373/*
374 * The verify_path function checks if a route to the src exists and
375 * if it is reachable via ifp (when provided).
376 *
377 * The 'verrevpath' option checks that the interface that an IP packet
378 * arrives on is the same interface that traffic destined for the
379 * packet's source address would be routed out of.
380 * The 'versrcreach' option just checks that the source address is
381 * reachable via any route (except default) in the routing table.
382 * These two are a measure to block forged packets. This is also
383 * commonly known as "anti-spoofing" or Unicast Reverse Path
384 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
385 * is purposely reminiscent of the Cisco IOS command,
386 *
387 * ip verify unicast reverse-path
388 * ip verify unicast source reachable-via any
389 *
390 * which implements the same functionality. But note that the syntax
391 * is misleading, and the check may be performed on all IP packets
392 * whether unicast, multicast, or broadcast.
393 */
394static int
395verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
396{
397#ifndef __FreeBSD__
398 return 0;
399#else
400 struct route ro;
401 struct sockaddr_in *dst;
402
403 bzero(&ro, sizeof(ro));
404
405 dst = (struct sockaddr_in *)&(ro.ro_dst);
406 dst->sin_family = AF_INET;
407 dst->sin_len = sizeof(*dst);
408 dst->sin_addr = src;
409 in_rtalloc_ign(&ro, 0, fib);
410
411 if (ro.ro_rt == NULL)
412 return 0;
413
414 /*
415 * If ifp is provided, check for equality with rtentry.
416 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
417 * in order to pass packets injected back by if_simloop():
418 * if useloopback == 1 routing entry (via lo0) for our own address
419 * may exist, so we need to handle routing assymetry.
420 */
421 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
422 RTFREE(ro.ro_rt);
423 return 0;
424 }
425
426 /* if no ifp provided, check if rtentry is not default route */
427 if (ifp == NULL &&
428 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
429 RTFREE(ro.ro_rt);
430 return 0;
431 }
432
433 /* or if this is a blackhole/reject route */
434 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
435 RTFREE(ro.ro_rt);
436 return 0;
437 }
438
439 /* found valid route */
440 RTFREE(ro.ro_rt);
441 return 1;
442#endif /* __FreeBSD__ */
443}
444
445#ifdef INET6
446/*
447 * ipv6 specific rules here...
448 */
449static __inline int
450icmp6type_match (int type, ipfw_insn_u32 *cmd)
451{
452 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
453}
454
455static int
456flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
457{
458 int i;
459 for (i=0; i <= cmd->o.arg1; ++i )
460 if (curr_flow == cmd->d[i] )
461 return 1;
462 return 0;
463}
464
465/* support for IP6_*_ME opcodes */
466static int
467search_ip6_addr_net (struct in6_addr * ip6_addr)
468{
469 struct ifnet *mdc;
470 struct ifaddr *mdc2;
471 struct in6_ifaddr *fdm;
472 struct in6_addr copia;
473
474 TAILQ_FOREACH(mdc, &V_ifnet, if_link) {
475 if_addr_rlock(mdc);
476 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) {
477 if (mdc2->ifa_addr->sa_family == AF_INET6) {
478 fdm = (struct in6_ifaddr *)mdc2;
479 copia = fdm->ia_addr.sin6_addr;
480 /* need for leaving scope_id in the sock_addr */
481 in6_clearscope(&copia);
482 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) {
483 if_addr_runlock(mdc);
484 return 1;
485 }
486 }
487 }
488 if_addr_runlock(mdc);
489 }
490 return 0;
491}
492
493static int
494verify_path6(struct in6_addr *src, struct ifnet *ifp)
495{
496 struct route_in6 ro;
497 struct sockaddr_in6 *dst;
498
499 bzero(&ro, sizeof(ro));
500
501 dst = (struct sockaddr_in6 * )&(ro.ro_dst);
502 dst->sin6_family = AF_INET6;
503 dst->sin6_len = sizeof(*dst);
504 dst->sin6_addr = *src;
505 /* XXX MRT 0 for ipv6 at this time */
506 rtalloc_ign((struct route *)&ro, 0);
507
508 if (ro.ro_rt == NULL)
509 return 0;
510
511 /*
512 * if ifp is provided, check for equality with rtentry
513 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
514 * to support the case of sending packets to an address of our own.
515 * (where the former interface is the first argument of if_simloop()
516 * (=ifp), the latter is lo0)
517 */
518 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
519 RTFREE(ro.ro_rt);
520 return 0;
521 }
522
523 /* if no ifp provided, check if rtentry is not default route */
524 if (ifp == NULL &&
525 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
526 RTFREE(ro.ro_rt);
527 return 0;
528 }
529
530 /* or if this is a blackhole/reject route */
531 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
532 RTFREE(ro.ro_rt);
533 return 0;
534 }
535
536 /* found valid route */
537 RTFREE(ro.ro_rt);
538 return 1;
539
540}
541
542static int
543is_icmp6_query(int icmp6_type)
544{
545 if ((icmp6_type <= ICMP6_MAXTYPE) &&
546 (icmp6_type == ICMP6_ECHO_REQUEST ||
547 icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
548 icmp6_type == ICMP6_WRUREQUEST ||
549 icmp6_type == ICMP6_FQDN_QUERY ||
550 icmp6_type == ICMP6_NI_QUERY))
551 return (1);
552
553 return (0);
554}
555
556static void
557send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
558{
559 struct mbuf *m;
560
561 m = args->m;
562 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
563 struct tcphdr *tcp;
564 tcp = (struct tcphdr *)((char *)ip6 + hlen);
565
566 if ((tcp->th_flags & TH_RST) == 0) {
567 struct mbuf *m0;
568 m0 = ipfw_send_pkt(args->m, &(args->f_id),
569 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
570 tcp->th_flags | TH_RST);
571 if (m0 != NULL)
572 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
573 NULL);
574 }
575 FREE_PKT(m);
576 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
577#if 0
578 /*
579 * Unlike above, the mbufs need to line up with the ip6 hdr,
580 * as the contents are read. We need to m_adj() the
581 * needed amount.
582 * The mbuf will however be thrown away so we can adjust it.
583 * Remember we did an m_pullup on it already so we
584 * can make some assumptions about contiguousness.
585 */
586 if (args->L3offset)
587 m_adj(m, args->L3offset);
588#endif
589 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
590 } else
591 FREE_PKT(m);
592
593 args->m = NULL;
594}
595
596#endif /* INET6 */
597
598
599/*
600 * sends a reject message, consuming the mbuf passed as an argument.
601 */
602static void
603send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
604{
605
606#if 0
607 /* XXX When ip is not guaranteed to be at mtod() we will
608 * need to account for this */
609 * The mbuf will however be thrown away so we can adjust it.
610 * Remember we did an m_pullup on it already so we
611 * can make some assumptions about contiguousness.
612 */
613 if (args->L3offset)
614 m_adj(m, args->L3offset);
615#endif
616 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
617 /* We need the IP header in host order for icmp_error(). */
618 SET_HOST_IPLEN(ip);
619 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
620 } else if (args->f_id.proto == IPPROTO_TCP) {
621 struct tcphdr *const tcp =
622 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
623 if ( (tcp->th_flags & TH_RST) == 0) {
624 struct mbuf *m;
625 m = ipfw_send_pkt(args->m, &(args->f_id),
626 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
627 tcp->th_flags | TH_RST);
628 if (m != NULL)
629 ip_output(m, NULL, NULL, 0, NULL, NULL);
630 }
631 FREE_PKT(args->m);
632 } else
633 FREE_PKT(args->m);
634 args->m = NULL;
635}
636
637/*
638 * Support for uid/gid/jail lookup. These tests are expensive
639 * (because we may need to look into the list of active sockets)
640 * so we cache the results. ugid_lookupp is 0 if we have not
641 * yet done a lookup, 1 if we succeeded, and -1 if we tried
642 * and failed. The function always returns the match value.
643 * We could actually spare the variable and use *uc, setting
644 * it to '(void *)check_uidgid if we have no info, NULL if
645 * we tried and failed, or any other value if successful.
646 */
647static int
648check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif,
649 struct in_addr dst_ip, u_int16_t dst_port, struct in_addr src_ip,
650 u_int16_t src_port, int *ugid_lookupp,
651 struct ucred **uc, struct inpcb *inp)
652{
653#ifndef __FreeBSD__
654 return cred_check(insn, proto, oif,
655 dst_ip, dst_port, src_ip, src_port,
656 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
657#else /* FreeBSD */
658 struct inpcbinfo *pi;
659 int wildcard;
660 struct inpcb *pcb;
661 int match;
662
663 /*
664 * Check to see if the UDP or TCP stack supplied us with
665 * the PCB. If so, rather then holding a lock and looking
666 * up the PCB, we can use the one that was supplied.
667 */
668 if (inp && *ugid_lookupp == 0) {
669 INP_LOCK_ASSERT(inp);
670 if (inp->inp_socket != NULL) {
671 *uc = crhold(inp->inp_cred);
672 *ugid_lookupp = 1;
673 } else
674 *ugid_lookupp = -1;
675 }
676 /*
677 * If we have already been here and the packet has no
678 * PCB entry associated with it, then we can safely
679 * assume that this is a no match.
680 */
681 if (*ugid_lookupp == -1)
682 return (0);
683 if (proto == IPPROTO_TCP) {
684 wildcard = 0;
685 pi = &V_tcbinfo;
686 } else if (proto == IPPROTO_UDP) {
687 wildcard = INPLOOKUP_WILDCARD;
688 pi = &V_udbinfo;
689 } else
690 return 0;
691 match = 0;
692 if (*ugid_lookupp == 0) {
693 INP_INFO_RLOCK(pi);
694 pcb = (oif) ?
695 in_pcblookup_hash(pi,
696 dst_ip, htons(dst_port),
697 src_ip, htons(src_port),
698 wildcard, oif) :
699 in_pcblookup_hash(pi,
700 src_ip, htons(src_port),
701 dst_ip, htons(dst_port),
702 wildcard, NULL);
703 if (pcb != NULL) {
704 *uc = crhold(pcb->inp_cred);
705 *ugid_lookupp = 1;
706 }
707 INP_INFO_RUNLOCK(pi);
708 if (*ugid_lookupp == 0) {
709 /*
710 * We tried and failed, set the variable to -1
711 * so we will not try again on this packet.
712 */
713 *ugid_lookupp = -1;
714 return (0);
715 }
716 }
717 if (insn->o.opcode == O_UID)
718 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
719 else if (insn->o.opcode == O_GID)
720 match = groupmember((gid_t)insn->d[0], *uc);
721 else if (insn->o.opcode == O_JAIL)
722 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
723 return match;
724#endif /* __FreeBSD__ */
725}
726
727/*
728 * Helper function to set args with info on the rule after the matching
729 * one. slot is precise, whereas we guess rule_id as they are
730 * assigned sequentially.
731 */
732static inline void
733set_match(struct ip_fw_args *args, int slot,
734 struct ip_fw_chain *chain)
735{
736 args->rule.chain_id = chain->id;
737 args->rule.slot = slot + 1; /* we use 0 as a marker */
738 args->rule.rule_id = 1 + chain->map[slot]->id;
739 args->rule.rulenum = chain->map[slot]->rulenum;
740}
741
742/*
743 * The main check routine for the firewall.
744 *
745 * All arguments are in args so we can modify them and return them
746 * back to the caller.
747 *
748 * Parameters:
749 *
750 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
751 * Starts with the IP header.
752 * args->eh (in) Mac header if present, NULL for layer3 packet.
753 * args->L3offset Number of bytes bypassed if we came from L2.
754 * e.g. often sizeof(eh) ** NOTYET **
755 * args->oif Outgoing interface, NULL if packet is incoming.
756 * The incoming interface is in the mbuf. (in)
757 * args->divert_rule (in/out)
758 * Skip up to the first rule past this rule number;
759 * upon return, non-zero port number for divert or tee.
760 *
761 * args->rule Pointer to the last matching rule (in/out)
762 * args->next_hop Socket we are forwarding to (out).
763 * args->f_id Addresses grabbed from the packet (out)
764 * args->rule.info a cookie depending on rule action
765 *
766 * Return value:
767 *
768 * IP_FW_PASS the packet must be accepted
769 * IP_FW_DENY the packet must be dropped
770 * IP_FW_DIVERT divert packet, port in m_tag
771 * IP_FW_TEE tee packet, port in m_tag
772 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie
773 * IP_FW_NETGRAPH into netgraph, cookie args->cookie
774 * args->rule contains the matching rule,
775 * args->rule.info has additional information.
776 *
777 */
778int
779ipfw_chk(struct ip_fw_args *args)
780{
781
782 /*
783 * Local variables holding state while processing a packet:
784 *
785 * IMPORTANT NOTE: to speed up the processing of rules, there
786 * are some assumption on the values of the variables, which
787 * are documented here. Should you change them, please check
788 * the implementation of the various instructions to make sure
789 * that they still work.
790 *
791 * args->eh The MAC header. It is non-null for a layer2
792 * packet, it is NULL for a layer-3 packet.
793 * **notyet**
794 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
795 *
796 * m | args->m Pointer to the mbuf, as received from the caller.
797 * It may change if ipfw_chk() does an m_pullup, or if it
798 * consumes the packet because it calls send_reject().
799 * XXX This has to change, so that ipfw_chk() never modifies
800 * or consumes the buffer.
801 * ip is the beginning of the ip(4 or 6) header.
802 * Calculated by adding the L3offset to the start of data.
803 * (Until we start using L3offset, the packet is
804 * supposed to start with the ip header).
805 */
806 struct mbuf *m = args->m;
807 struct ip *ip = mtod(m, struct ip *);
808
809 /*
810 * For rules which contain uid/gid or jail constraints, cache
811 * a copy of the users credentials after the pcb lookup has been
812 * executed. This will speed up the processing of rules with
813 * these types of constraints, as well as decrease contention
814 * on pcb related locks.
815 */
816#ifndef __FreeBSD__
817 struct bsd_ucred ucred_cache;
818#else
819 struct ucred *ucred_cache = NULL;
820#endif
821 int ucred_lookup = 0;
822
823 /*
824 * oif | args->oif If NULL, ipfw_chk has been called on the
825 * inbound path (ether_input, ip_input).
826 * If non-NULL, ipfw_chk has been called on the outbound path
827 * (ether_output, ip_output).
828 */
829 struct ifnet *oif = args->oif;
830
831 int f_pos = 0; /* index of current rule in the array */
832 int retval = 0;
833
834 /*
835 * hlen The length of the IP header.
836 */
837 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
838
839 /*
840 * offset The offset of a fragment. offset != 0 means that
841 * we have a fragment at this offset of an IPv4 packet.
842 * offset == 0 means that (if this is an IPv4 packet)
843 * this is the first or only fragment.
844 * For IPv6 offset == 0 means there is no Fragment Header.
845 * If offset != 0 for IPv6 always use correct mask to
846 * get the correct offset because we add IP6F_MORE_FRAG
847 * to be able to dectect the first fragment which would
848 * otherwise have offset = 0.
849 */
850 u_short offset = 0;
851
852 /*
853 * Local copies of addresses. They are only valid if we have
854 * an IP packet.
855 *
856 * proto The protocol. Set to 0 for non-ip packets,
857 * or to the protocol read from the packet otherwise.
858 * proto != 0 means that we have an IPv4 packet.
859 *
860 * src_port, dst_port port numbers, in HOST format. Only
861 * valid for TCP and UDP packets.
862 *
863 * src_ip, dst_ip ip addresses, in NETWORK format.
864 * Only valid for IPv4 packets.
865 */
866 uint8_t proto;
867 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */
868 struct in_addr src_ip, dst_ip; /* NOTE: network format */
869 uint16_t iplen=0;
870 int pktlen;
871 uint16_t etype = 0; /* Host order stored ether type */
872
873 /*
874 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
875 * MATCH_NONE when checked and not matched (q = NULL),
876 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
877 */
878 int dyn_dir = MATCH_UNKNOWN;
879 ipfw_dyn_rule *q = NULL;
880 struct ip_fw_chain *chain = &V_layer3_chain;
881
882 /*
883 * We store in ulp a pointer to the upper layer protocol header.
884 * In the ipv4 case this is easy to determine from the header,
885 * but for ipv6 we might have some additional headers in the middle.
886 * ulp is NULL if not found.
887 */
888 void *ulp = NULL; /* upper layer protocol pointer. */
889
890 /* XXX ipv6 variables */
891 int is_ipv6 = 0;
892 uint8_t icmp6_type = 0;
893 uint16_t ext_hd = 0; /* bits vector for extension header filtering */
894 /* end of ipv6 variables */
895
896 int is_ipv4 = 0;
897
898 int done = 0; /* flag to exit the outer loop */
899
900 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
901 return (IP_FW_PASS); /* accept */
902
903 dst_ip.s_addr = 0; /* make sure it is initialized */
904 src_ip.s_addr = 0; /* make sure it is initialized */
905 pktlen = m->m_pkthdr.len;
906 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
907 proto = args->f_id.proto = 0; /* mark f_id invalid */
908 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
909
910/*
911 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
912 * then it sets p to point at the offset "len" in the mbuf. WARNING: the
913 * pointer might become stale after other pullups (but we never use it
914 * this way).
915 */
916#define PULLUP_TO(_len, p, T) \
917do { \
918 int x = (_len) + sizeof(T); \
919 if ((m)->m_len < x) { \
920 args->m = m = m_pullup(m, x); \
921 if (m == NULL) \
922 goto pullup_failed; \
923 } \
924 p = (mtod(m, char *) + (_len)); \
925} while (0)
926
927 /*
928 * if we have an ether header,
929 */
930 if (args->eh)
931 etype = ntohs(args->eh->ether_type);
932
933 /* Identify IP packets and fill up variables. */
934 if (pktlen >= sizeof(struct ip6_hdr) &&
935 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
936 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
937 is_ipv6 = 1;
938 args->f_id.addr_type = 6;
939 hlen = sizeof(struct ip6_hdr);
940 proto = ip6->ip6_nxt;
941
942 /* Search extension headers to find upper layer protocols */
943 while (ulp == NULL) {
944 switch (proto) {
945 case IPPROTO_ICMPV6:
946 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
947 icmp6_type = ICMP6(ulp)->icmp6_type;
948 break;
949
950 case IPPROTO_TCP:
951 PULLUP_TO(hlen, ulp, struct tcphdr);
952 dst_port = TCP(ulp)->th_dport;
953 src_port = TCP(ulp)->th_sport;
954 /* save flags for dynamic rules */
955 args->f_id._flags = TCP(ulp)->th_flags;
956 break;
957
958 case IPPROTO_SCTP:
959 PULLUP_TO(hlen, ulp, struct sctphdr);
960 src_port = SCTP(ulp)->src_port;
961 dst_port = SCTP(ulp)->dest_port;
962 break;
963
964 case IPPROTO_UDP:
965 PULLUP_TO(hlen, ulp, struct udphdr);
966 dst_port = UDP(ulp)->uh_dport;
967 src_port = UDP(ulp)->uh_sport;
968 break;
969
970 case IPPROTO_HOPOPTS: /* RFC 2460 */
971 PULLUP_TO(hlen, ulp, struct ip6_hbh);
972 ext_hd |= EXT_HOPOPTS;
973 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
974 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
975 ulp = NULL;
976 break;
977
978 case IPPROTO_ROUTING: /* RFC 2460 */
979 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
980 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
981 case 0:
982 ext_hd |= EXT_RTHDR0;
983 break;
984 case 2:
985 ext_hd |= EXT_RTHDR2;
986 break;
987 default:
988 printf("IPFW2: IPV6 - Unknown Routing "
989 "Header type(%d)\n",
990 ((struct ip6_rthdr *)ulp)->ip6r_type);
991 if (V_fw_deny_unknown_exthdrs)
992 return (IP_FW_DENY);
993 break;
994 }
995 ext_hd |= EXT_ROUTING;
996 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
997 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
998 ulp = NULL;
999 break;
1000
1001 case IPPROTO_FRAGMENT: /* RFC 2460 */
1002 PULLUP_TO(hlen, ulp, struct ip6_frag);
1003 ext_hd |= EXT_FRAGMENT;
1004 hlen += sizeof (struct ip6_frag);
1005 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1006 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1007 IP6F_OFF_MASK;
1008 /* Add IP6F_MORE_FRAG for offset of first
1009 * fragment to be != 0. */
1010 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg &
1011 IP6F_MORE_FRAG;
1012 if (offset == 0) {
1013 printf("IPFW2: IPV6 - Invalid Fragment "
1014 "Header\n");
1015 if (V_fw_deny_unknown_exthdrs)
1016 return (IP_FW_DENY);
1017 break;
1018 }
1019 args->f_id.extra =
1020 ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1021 ulp = NULL;
1022 break;
1023
1024 case IPPROTO_DSTOPTS: /* RFC 2460 */
1025 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1026 ext_hd |= EXT_DSTOPTS;
1027 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1028 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1029 ulp = NULL;
1030 break;
1031
1032 case IPPROTO_AH: /* RFC 2402 */
1033 PULLUP_TO(hlen, ulp, struct ip6_ext);
1034 ext_hd |= EXT_AH;
1035 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1036 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1037 ulp = NULL;
1038 break;
1039
1040 case IPPROTO_ESP: /* RFC 2406 */
1041 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1042 /* Anything past Seq# is variable length and
1043 * data past this ext. header is encrypted. */
1044 ext_hd |= EXT_ESP;
1045 break;
1046
1047 case IPPROTO_NONE: /* RFC 2460 */
1048 /*
1049 * Packet ends here, and IPv6 header has
1050 * already been pulled up. If ip6e_len!=0
1051 * then octets must be ignored.
1052 */
1053 ulp = ip; /* non-NULL to get out of loop. */
1054 break;
1055
1056 case IPPROTO_OSPFIGP:
1057 /* XXX OSPF header check? */
1058 PULLUP_TO(hlen, ulp, struct ip6_ext);
1059 break;
1060
1061 case IPPROTO_PIM:
1062 /* XXX PIM header check? */
1063 PULLUP_TO(hlen, ulp, struct pim);
1064 break;
1065
1066 case IPPROTO_CARP:
1067 PULLUP_TO(hlen, ulp, struct carp_header);
1068 if (((struct carp_header *)ulp)->carp_version !=
1069 CARP_VERSION)
1070 return (IP_FW_DENY);
1071 if (((struct carp_header *)ulp)->carp_type !=
1072 CARP_ADVERTISEMENT)
1073 return (IP_FW_DENY);
1074 break;
1075
1076 case IPPROTO_IPV6: /* RFC 2893 */
1077 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1078 break;
1079
1080 case IPPROTO_IPV4: /* RFC 2893 */
1081 PULLUP_TO(hlen, ulp, struct ip);
1082 break;
1083
1084 default:
1085 printf("IPFW2: IPV6 - Unknown Extension "
1086 "Header(%d), ext_hd=%x\n", proto, ext_hd);
1087 if (V_fw_deny_unknown_exthdrs)
1088 return (IP_FW_DENY);
1089 PULLUP_TO(hlen, ulp, struct ip6_ext);
1090 break;
1091 } /*switch */
1092 }
1093 ip = mtod(m, struct ip *);
1094 ip6 = (struct ip6_hdr *)ip;
1095 args->f_id.src_ip6 = ip6->ip6_src;
1096 args->f_id.dst_ip6 = ip6->ip6_dst;
1097 args->f_id.src_ip = 0;
1098 args->f_id.dst_ip = 0;
1099 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1100 } else if (pktlen >= sizeof(struct ip) &&
1101 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1102 is_ipv4 = 1;
1103 hlen = ip->ip_hl << 2;
1104 args->f_id.addr_type = 4;
1105
1106 /*
1107 * Collect parameters into local variables for faster matching.
1108 */
1109 proto = ip->ip_p;
1110 src_ip = ip->ip_src;
1111 dst_ip = ip->ip_dst;
1112 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1113 iplen = ntohs(ip->ip_len);
1114 pktlen = iplen < pktlen ? iplen : pktlen;
1115
1116 if (offset == 0) {
1117 switch (proto) {
1118 case IPPROTO_TCP:
1119 PULLUP_TO(hlen, ulp, struct tcphdr);
1120 dst_port = TCP(ulp)->th_dport;
1121 src_port = TCP(ulp)->th_sport;
1122 /* save flags for dynamic rules */
1123 args->f_id._flags = TCP(ulp)->th_flags;
1124 break;
1125
1126 case IPPROTO_UDP:
1127 PULLUP_TO(hlen, ulp, struct udphdr);
1128 dst_port = UDP(ulp)->uh_dport;
1129 src_port = UDP(ulp)->uh_sport;
1130 break;
1131
1132 case IPPROTO_ICMP:
1133 PULLUP_TO(hlen, ulp, struct icmphdr);
1134 //args->f_id.flags = ICMP(ulp)->icmp_type;
1135 break;
1136
1137 default:
1138 break;
1139 }
1140 }
1141
1142 ip = mtod(m, struct ip *);
1143 args->f_id.src_ip = ntohl(src_ip.s_addr);
1144 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1145 }
1146#undef PULLUP_TO
1147 if (proto) { /* we may have port numbers, store them */
1148 args->f_id.proto = proto;
1149 args->f_id.src_port = src_port = ntohs(src_port);
1150 args->f_id.dst_port = dst_port = ntohs(dst_port);
1151 }
1152
1153 IPFW_RLOCK(chain);
1154 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1155 IPFW_RUNLOCK(chain);
1156 return (IP_FW_PASS); /* accept */
1157 }
1158 if (args->rule.slot) {
1159 /*
1160 * Packet has already been tagged as a result of a previous
1161 * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1162 * REASS, NETGRAPH, DIVERT/TEE...)
1163 * Validate the slot and continue from the next one
1164 * if still present, otherwise do a lookup.
1165 */
1166 f_pos = (args->rule.chain_id == chain->id) ?
1167 args->rule.slot :
1168 ipfw_find_rule(chain, args->rule.rulenum,
1169 args->rule.rule_id);
1170 } else {
1171 f_pos = 0;
1172 }
1173
1174 /*
1175 * Now scan the rules, and parse microinstructions for each rule.
1176 * We have two nested loops and an inner switch. Sometimes we
1177 * need to break out of one or both loops, or re-enter one of
1178 * the loops with updated variables. Loop variables are:
1179 *
1180 * f_pos (outer loop) points to the current rule.
1181 * On output it points to the matching rule.
1182 * done (outer loop) is used as a flag to break the loop.
1183 * l (inner loop) residual length of current rule.
1184 * cmd points to the current microinstruction.
1185 *
1186 * We break the inner loop by setting l=0 and possibly
1187 * cmdlen=0 if we don't want to advance cmd.
1188 * We break the outer loop by setting done=1
1189 * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1190 * as needed.
1191 */
1192 for (; f_pos < chain->n_rules; f_pos++) {
1193 ipfw_insn *cmd;
1194 uint32_t tablearg = 0;
1195 int l, cmdlen, skip_or; /* skip rest of OR block */
1196 struct ip_fw *f;
1197
1198 f = chain->map[f_pos];
1199 if (V_set_disable & (1 << f->set) )
1200 continue;
1201
1202 skip_or = 0;
1203 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1204 l -= cmdlen, cmd += cmdlen) {
1205 int match;
1206
1207 /*
1208 * check_body is a jump target used when we find a
1209 * CHECK_STATE, and need to jump to the body of
1210 * the target rule.
1211 */
1212
1213/* check_body: */
1214 cmdlen = F_LEN(cmd);
1215 /*
1216 * An OR block (insn_1 || .. || insn_n) has the
1217 * F_OR bit set in all but the last instruction.
1218 * The first match will set "skip_or", and cause
1219 * the following instructions to be skipped until
1220 * past the one with the F_OR bit clear.
1221 */
1222 if (skip_or) { /* skip this instruction */
1223 if ((cmd->len & F_OR) == 0)
1224 skip_or = 0; /* next one is good */
1225 continue;
1226 }
1227 match = 0; /* set to 1 if we succeed */
1228
1229 switch (cmd->opcode) {
1230 /*
1231 * The first set of opcodes compares the packet's
1232 * fields with some pattern, setting 'match' if a
1233 * match is found. At the end of the loop there is
1234 * logic to deal with F_NOT and F_OR flags associated
1235 * with the opcode.
1236 */
1237 case O_NOP:
1238 match = 1;
1239 break;
1240
1241 case O_FORWARD_MAC:
1242 printf("ipfw: opcode %d unimplemented\n",
1243 cmd->opcode);
1244 break;
1245
1246 case O_GID:
1247 case O_UID:
1248 case O_JAIL:
1249 /*
1250 * We only check offset == 0 && proto != 0,
1251 * as this ensures that we have a
1252 * packet with the ports info.
1253 */
1254 if (offset!=0)
1255 break;
1256 if (is_ipv6) /* XXX to be fixed later */
1257 break;
1258 if (proto == IPPROTO_TCP ||
1259 proto == IPPROTO_UDP)
1260 match = check_uidgid(
1261 (ipfw_insn_u32 *)cmd,
1262 proto, oif,
1263 dst_ip, dst_port,
1264 src_ip, src_port, &ucred_lookup,
1265#ifdef __FreeBSD__
1266 &ucred_cache, args->inp);
1267#else
1268 (void *)&ucred_cache,
1269 (struct inpcb *)args->m);
1270#endif
1271 break;
1272
1273 case O_RECV:
1274 match = iface_match(m->m_pkthdr.rcvif,
1275 (ipfw_insn_if *)cmd);
1276 break;
1277
1278 case O_XMIT:
1279 match = iface_match(oif, (ipfw_insn_if *)cmd);
1280 break;
1281
1282 case O_VIA:
1283 match = iface_match(oif ? oif :
1284 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1285 break;
1286
1287 case O_MACADDR2:
1288 if (args->eh != NULL) { /* have MAC header */
1289 u_int32_t *want = (u_int32_t *)
1290 ((ipfw_insn_mac *)cmd)->addr;
1291 u_int32_t *mask = (u_int32_t *)
1292 ((ipfw_insn_mac *)cmd)->mask;
1293 u_int32_t *hdr = (u_int32_t *)args->eh;
1294
1295 match =
1296 ( want[0] == (hdr[0] & mask[0]) &&
1297 want[1] == (hdr[1] & mask[1]) &&
1298 want[2] == (hdr[2] & mask[2]) );
1299 }
1300 break;
1301
1302 case O_MAC_TYPE:
1303 if (args->eh != NULL) {
1304 u_int16_t *p =
1305 ((ipfw_insn_u16 *)cmd)->ports;
1306 int i;
1307
1308 for (i = cmdlen - 1; !match && i>0;
1309 i--, p += 2)
1310 match = (etype >= p[0] &&
1311 etype <= p[1]);
1312 }
1313 break;
1314
1315 case O_FRAG:
1316 match = (offset != 0);
1317 break;
1318
1319 case O_IN: /* "out" is "not in" */
1320 match = (oif == NULL);
1321 break;
1322
1323 case O_LAYER2:
1324 match = (args->eh != NULL);
1325 break;
1326
1327 case O_DIVERTED:
1328 {
1329 /* For diverted packets, args->rule.info
1330 * contains the divert port (in host format)
1331 * reason and direction.
1332 */
1333 uint32_t i = args->rule.info;
1334 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1335 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1336 }
1337 break;
1338
1339 case O_PROTO:
1340 /*
1341 * We do not allow an arg of 0 so the
1342 * check of "proto" only suffices.
1343 */
1344 match = (proto == cmd->arg1);
1345 break;
1346
1347 case O_IP_SRC:
1348 match = is_ipv4 &&
1349 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1350 src_ip.s_addr);
1351 break;
1352
1353 case O_IP_SRC_LOOKUP:
1354 case O_IP_DST_LOOKUP:
1355 if (is_ipv4) {
1356 uint32_t key =
1357 (cmd->opcode == O_IP_DST_LOOKUP) ?
1358 dst_ip.s_addr : src_ip.s_addr;
1359 uint32_t v = 0;
1360
1361 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1362 /* generic lookup. The key must be
1363 * in 32bit big-endian format.
1364 */
1365 v = ((ipfw_insn_u32 *)cmd)->d[1];
1366 if (v == 0)
1367 key = dst_ip.s_addr;
1368 else if (v == 1)
1369 key = src_ip.s_addr;
1370 else if (v == 6) /* dscp */
1371 key = (ip->ip_tos >> 2) & 0x3f;
1372 else if (offset != 0)
1373 break;
1374 else if (proto != IPPROTO_TCP &&
1375 proto != IPPROTO_UDP)
1376 break;
1377 else if (v == 2)
1378 key = htonl(dst_port);
1379 else if (v == 3)
1380 key = htonl(src_port);
1381 else if (v == 4 || v == 5) {
1382 check_uidgid(
1383 (ipfw_insn_u32 *)cmd,
1384 proto, oif,
1385 dst_ip, dst_port,
1386 src_ip, src_port, &ucred_lookup,
1387#ifdef __FreeBSD__
1388 &ucred_cache, args->inp);
1389 if (v == 4 /* O_UID */)
1390 key = ucred_cache->cr_uid;
1391 else if (v == 5 /* O_JAIL */)
1392 key = ucred_cache->cr_prison->pr_id;
1393#else /* !__FreeBSD__ */
1394 (void *)&ucred_cache,
1395 (struct inpcb *)args->m);
1396 if (v ==4 /* O_UID */)
1397 key = ucred_cache.uid;
1398 else if (v == 5 /* O_JAIL */)
1399 key = ucred_cache.xid;
1400#endif /* !__FreeBSD__ */
1401 key = htonl(key);
1402 } else
1403 break;
1404 }
1405 match = ipfw_lookup_table(chain,
1406 cmd->arg1, key, &v);
1407 if (!match)
1408 break;
1409 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1410 match =
1411 ((ipfw_insn_u32 *)cmd)->d[0] == v;
1412 else
1413 tablearg = v;
1414 }
1415 break;
1416
1417 case O_IP_SRC_MASK:
1418 case O_IP_DST_MASK:
1419 if (is_ipv4) {
1420 uint32_t a =
1421 (cmd->opcode == O_IP_DST_MASK) ?
1422 dst_ip.s_addr : src_ip.s_addr;
1423 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1424 int i = cmdlen-1;
1425
1426 for (; !match && i>0; i-= 2, p+= 2)
1427 match = (p[0] == (a & p[1]));
1428 }
1429 break;
1430
1431 case O_IP_SRC_ME:
1432 if (is_ipv4) {
1433 struct ifnet *tif;
1434
1435 INADDR_TO_IFP(src_ip, tif);
1436 match = (tif != NULL);
1437 break;
1438 }
1439#ifdef INET6
1440 /* FALLTHROUGH */
1441 case O_IP6_SRC_ME:
1442 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
1443#endif
1444 break;
1445
1446 case O_IP_DST_SET:
1447 case O_IP_SRC_SET:
1448 if (is_ipv4) {
1449 u_int32_t *d = (u_int32_t *)(cmd+1);
1450 u_int32_t addr =
1451 cmd->opcode == O_IP_DST_SET ?
1452 args->f_id.dst_ip :
1453 args->f_id.src_ip;
1454
1455 if (addr < d[0])
1456 break;
1457 addr -= d[0]; /* subtract base */
1458 match = (addr < cmd->arg1) &&
1459 ( d[ 1 + (addr>>5)] &
1460 (1<<(addr & 0x1f)) );
1461 }
1462 break;
1463
1464 case O_IP_DST:
1465 match = is_ipv4 &&
1466 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1467 dst_ip.s_addr);
1468 break;
1469
1470 case O_IP_DST_ME:
1471 if (is_ipv4) {
1472 struct ifnet *tif;
1473
1474 INADDR_TO_IFP(dst_ip, tif);
1475 match = (tif != NULL);
1476 break;
1477 }
1478#ifdef INET6
1479 /* FALLTHROUGH */
1480 case O_IP6_DST_ME:
1481 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
1482#endif
1483 break;
1484
1485
1486 case O_IP_SRCPORT:
1487 case O_IP_DSTPORT:
1488 /*
1489 * offset == 0 && proto != 0 is enough
1490 * to guarantee that we have a
1491 * packet with port info.
1492 */
1493 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1494 && offset == 0) {
1495 u_int16_t x =
1496 (cmd->opcode == O_IP_SRCPORT) ?
1497 src_port : dst_port ;
1498 u_int16_t *p =
1499 ((ipfw_insn_u16 *)cmd)->ports;
1500 int i;
1501
1502 for (i = cmdlen - 1; !match && i>0;
1503 i--, p += 2)
1504 match = (x>=p[0] && x<=p[1]);
1505 }
1506 break;
1507
1508 case O_ICMPTYPE:
1509 match = (offset == 0 && proto==IPPROTO_ICMP &&
1510 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1511 break;
1512
1513#ifdef INET6
1514 case O_ICMP6TYPE:
1515 match = is_ipv6 && offset == 0 &&
1516 proto==IPPROTO_ICMPV6 &&
1517 icmp6type_match(
1518 ICMP6(ulp)->icmp6_type,
1519 (ipfw_insn_u32 *)cmd);
1520 break;
1521#endif /* INET6 */
1522
1523 case O_IPOPT:
1524 match = (is_ipv4 &&
1525 ipopts_match(ip, cmd) );
1526 break;
1527
1528 case O_IPVER:
1529 match = (is_ipv4 &&
1530 cmd->arg1 == ip->ip_v);
1531 break;
1532
1533 case O_IPID:
1534 case O_IPLEN:
1535 case O_IPTTL:
1536 if (is_ipv4) { /* only for IP packets */
1537 uint16_t x;
1538 uint16_t *p;
1539 int i;
1540
1541 if (cmd->opcode == O_IPLEN)
1542 x = iplen;
1543 else if (cmd->opcode == O_IPTTL)
1544 x = ip->ip_ttl;
1545 else /* must be IPID */
1546 x = ntohs(ip->ip_id);
1547 if (cmdlen == 1) {
1548 match = (cmd->arg1 == x);
1549 break;
1550 }
1551 /* otherwise we have ranges */
1552 p = ((ipfw_insn_u16 *)cmd)->ports;
1553 i = cmdlen - 1;
1554 for (; !match && i>0; i--, p += 2)
1555 match = (x >= p[0] && x <= p[1]);
1556 }
1557 break;
1558
1559 case O_IPPRECEDENCE:
1560 match = (is_ipv4 &&
1561 (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1562 break;
1563
1564 case O_IPTOS:
1565 match = (is_ipv4 &&
1566 flags_match(cmd, ip->ip_tos));
1567 break;
1568
1569 case O_TCPDATALEN:
1570 if (proto == IPPROTO_TCP && offset == 0) {
1571 struct tcphdr *tcp;
1572 uint16_t x;
1573 uint16_t *p;
1574 int i;
1575
1576 tcp = TCP(ulp);
1577 x = iplen -
1578 ((ip->ip_hl + tcp->th_off) << 2);
1579 if (cmdlen == 1) {
1580 match = (cmd->arg1 == x);
1581 break;
1582 }
1583 /* otherwise we have ranges */
1584 p = ((ipfw_insn_u16 *)cmd)->ports;
1585 i = cmdlen - 1;
1586 for (; !match && i>0; i--, p += 2)
1587 match = (x >= p[0] && x <= p[1]);
1588 }
1589 break;
1590
1591 case O_TCPFLAGS:
1592 match = (proto == IPPROTO_TCP && offset == 0 &&
1593 flags_match(cmd, TCP(ulp)->th_flags));
1594 break;
1595
1596 case O_TCPOPTS:
1597 match = (proto == IPPROTO_TCP && offset == 0 &&
1598 tcpopts_match(TCP(ulp), cmd));
1599 break;
1600
1601 case O_TCPSEQ:
1602 match = (proto == IPPROTO_TCP && offset == 0 &&
1603 ((ipfw_insn_u32 *)cmd)->d[0] ==
1604 TCP(ulp)->th_seq);
1605 break;
1606
1607 case O_TCPACK:
1608 match = (proto == IPPROTO_TCP && offset == 0 &&
1609 ((ipfw_insn_u32 *)cmd)->d[0] ==
1610 TCP(ulp)->th_ack);
1611 break;
1612
1613 case O_TCPWIN:
1614 match = (proto == IPPROTO_TCP && offset == 0 &&
1615 cmd->arg1 == TCP(ulp)->th_win);
1616 break;
1617
1618 case O_ESTAB:
1619 /* reject packets which have SYN only */
1620 /* XXX should i also check for TH_ACK ? */
1621 match = (proto == IPPROTO_TCP && offset == 0 &&
1622 (TCP(ulp)->th_flags &
1623 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1624 break;
1625
1626 case O_ALTQ: {
1627 struct pf_mtag *at;
1628 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1629
1630 match = 1;
1631 at = pf_find_mtag(m);
1632 if (at != NULL && at->qid != 0)
1633 break;
1634 at = pf_get_mtag(m);
1635 if (at == NULL) {
1636 /*
1637 * Let the packet fall back to the
1638 * default ALTQ.
1639 */
1640 break;
1641 }
1642 at->qid = altq->qid;
1643 if (is_ipv4)
1644 at->af = AF_INET;
1645 else
1646 at->af = AF_LINK;
1647 at->hdr = ip;
1648 break;
1649 }
1650
1651 case O_LOG:
1652 ipfw_log(f, hlen, args, m,
1653 oif, offset, tablearg, ip);
1654 match = 1;
1655 break;
1656
1657 case O_PROB:
1658 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1659 break;
1660
1661 case O_VERREVPATH:
1662 /* Outgoing packets automatically pass/match */
1663 match = ((oif != NULL) ||
1664 (m->m_pkthdr.rcvif == NULL) ||
1665 (
1666#ifdef INET6
1667 is_ipv6 ?
1668 verify_path6(&(args->f_id.src_ip6),
1669 m->m_pkthdr.rcvif) :
1670#endif
1671 verify_path(src_ip, m->m_pkthdr.rcvif,
1672 args->f_id.fib)));
1673 break;
1674
1675 case O_VERSRCREACH:
1676 /* Outgoing packets automatically pass/match */
1677 match = (hlen > 0 && ((oif != NULL) ||
1678#ifdef INET6
1679 is_ipv6 ?
1680 verify_path6(&(args->f_id.src_ip6),
1681 NULL) :
1682#endif
1683 verify_path(src_ip, NULL, args->f_id.fib)));
1684 break;
1685
1686 case O_ANTISPOOF:
1687 /* Outgoing packets automatically pass/match */
1688 if (oif == NULL && hlen > 0 &&
1689 ( (is_ipv4 && in_localaddr(src_ip))
1690#ifdef INET6
1691 || (is_ipv6 &&
1692 in6_localaddr(&(args->f_id.src_ip6)))
1693#endif
1694 ))
1695 match =
1696#ifdef INET6
1697 is_ipv6 ? verify_path6(
1698 &(args->f_id.src_ip6),
1699 m->m_pkthdr.rcvif) :
1700#endif
1701 verify_path(src_ip,
1702 m->m_pkthdr.rcvif,
1703 args->f_id.fib);
1704 else
1705 match = 1;
1706 break;
1707
1708 case O_IPSEC:
1709#ifdef IPSEC
1710 match = (m_tag_find(m,
1711 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1712#endif
1713 /* otherwise no match */
1714 break;
1715
1716#ifdef INET6
1717 case O_IP6_SRC:
1718 match = is_ipv6 &&
1719 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1720 &((ipfw_insn_ip6 *)cmd)->addr6);
1721 break;
1722
1723 case O_IP6_DST:
1724 match = is_ipv6 &&
1725 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1726 &((ipfw_insn_ip6 *)cmd)->addr6);
1727 break;
1728 case O_IP6_SRC_MASK:
1729 case O_IP6_DST_MASK:
1730 if (is_ipv6) {
1731 int i = cmdlen - 1;
1732 struct in6_addr p;
1733 struct in6_addr *d =
1734 &((ipfw_insn_ip6 *)cmd)->addr6;
1735
1736 for (; !match && i > 0; d += 2,
1737 i -= F_INSN_SIZE(struct in6_addr)
1738 * 2) {
1739 p = (cmd->opcode ==
1740 O_IP6_SRC_MASK) ?
1741 args->f_id.src_ip6:
1742 args->f_id.dst_ip6;
1743 APPLY_MASK(&p, &d[1]);
1744 match =
1745 IN6_ARE_ADDR_EQUAL(&d[0],
1746 &p);
1747 }
1748 }
1749 break;
1750
1751 case O_FLOW6ID:
1752 match = is_ipv6 &&
1753 flow6id_match(args->f_id.flow_id6,
1754 (ipfw_insn_u32 *) cmd);
1755 break;
1756
1757 case O_EXT_HDR:
1758 match = is_ipv6 &&
1759 (ext_hd & ((ipfw_insn *) cmd)->arg1);
1760 break;
1761
1762 case O_IP6:
1763 match = is_ipv6;
1764 break;
1765#endif
1766
1767 case O_IP4:
1768 match = is_ipv4;
1769 break;
1770
1771 case O_TAG: {
1772 struct m_tag *mtag;
1773 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1774 tablearg : cmd->arg1;
1775
1776 /* Packet is already tagged with this tag? */
1777 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1778
1779 /* We have `untag' action when F_NOT flag is
1780 * present. And we must remove this mtag from
1781 * mbuf and reset `match' to zero (`match' will
1782 * be inversed later).
1783 * Otherwise we should allocate new mtag and
1784 * push it into mbuf.
1785 */
1786 if (cmd->len & F_NOT) { /* `untag' action */
1787 if (mtag != NULL)
1788 m_tag_delete(m, mtag);
1789 match = 0;
1790 } else if (mtag == NULL) {
1791 if ((mtag = m_tag_alloc(MTAG_IPFW,
1792 tag, 0, M_NOWAIT)) != NULL)
1793 m_tag_prepend(m, mtag);
1794 match = 1;
1795 }
1796 break;
1797 }
1798
1799 case O_FIB: /* try match the specified fib */
1800 if (args->f_id.fib == cmd->arg1)
1801 match = 1;
1802 break;
1803
1804 case O_SOCKARG: {
1805 struct inpcb *inp = args->inp;
1806 struct inpcbinfo *pi;
1807
1808 if (is_ipv6) /* XXX can we remove this ? */
1809 break;
1810
1811 if (proto == IPPROTO_TCP)
1812 pi = &V_tcbinfo;
1813 else if (proto == IPPROTO_UDP)
1814 pi = &V_udbinfo;
1815 else
1816 break;
1817
1818 /* For incomming packet, lookup up the
1819 inpcb using the src/dest ip/port tuple */
1820 if (inp == NULL) {
1821 INP_INFO_RLOCK(pi);
1822 inp = in_pcblookup_hash(pi,
1823 src_ip, htons(src_port),
1824 dst_ip, htons(dst_port),
1825 0, NULL);
1826 INP_INFO_RUNLOCK(pi);
1827 }
1828
1829 if (inp && inp->inp_socket) {
1830 tablearg = inp->inp_socket->so_user_cookie;
1831 if (tablearg)
1832 match = 1;
1833 }
1834 break;
1835 }
1836
1837 case O_TAGGED: {
1838 struct m_tag *mtag;
1839 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1840 tablearg : cmd->arg1;
1841
1842 if (cmdlen == 1) {
1843 match = m_tag_locate(m, MTAG_IPFW,
1844 tag, NULL) != NULL;
1845 break;
1846 }
1847
1848 /* we have ranges */
1849 for (mtag = m_tag_first(m);
1850 mtag != NULL && !match;
1851 mtag = m_tag_next(m, mtag)) {
1852 uint16_t *p;
1853 int i;
1854
1855 if (mtag->m_tag_cookie != MTAG_IPFW)
1856 continue;
1857
1858 p = ((ipfw_insn_u16 *)cmd)->ports;
1859 i = cmdlen - 1;
1860 for(; !match && i > 0; i--, p += 2)
1861 match =
1862 mtag->m_tag_id >= p[0] &&
1863 mtag->m_tag_id <= p[1];
1864 }
1865 break;
1866 }
1867
1868 /*
1869 * The second set of opcodes represents 'actions',
1870 * i.e. the terminal part of a rule once the packet
1871 * matches all previous patterns.
1872 * Typically there is only one action for each rule,
1873 * and the opcode is stored at the end of the rule
1874 * (but there are exceptions -- see below).
1875 *
1876 * In general, here we set retval and terminate the
1877 * outer loop (would be a 'break 3' in some language,
1878 * but we need to set l=0, done=1)
1879 *
1880 * Exceptions:
1881 * O_COUNT and O_SKIPTO actions:
1882 * instead of terminating, we jump to the next rule
1883 * (setting l=0), or to the SKIPTO target (setting
1884 * f/f_len, cmd and l as needed), respectively.
1885 *
1886 * O_TAG, O_LOG and O_ALTQ action parameters:
1887 * perform some action and set match = 1;
1888 *
1889 * O_LIMIT and O_KEEP_STATE: these opcodes are
1890 * not real 'actions', and are stored right
1891 * before the 'action' part of the rule.
1892 * These opcodes try to install an entry in the
1893 * state tables; if successful, we continue with
1894 * the next opcode (match=1; break;), otherwise
1895 * the packet must be dropped (set retval,
1896 * break loops with l=0, done=1)
1897 *
1898 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1899 * cause a lookup of the state table, and a jump
1900 * to the 'action' part of the parent rule
1901 * if an entry is found, or
1902 * (CHECK_STATE only) a jump to the next rule if
1903 * the entry is not found.
1904 * The result of the lookup is cached so that
1905 * further instances of these opcodes become NOPs.
1906 * The jump to the next rule is done by setting
1907 * l=0, cmdlen=0.
1908 */
1909 case O_LIMIT:
1910 case O_KEEP_STATE:
1911 if (ipfw_install_state(f,
1912 (ipfw_insn_limit *)cmd, args, tablearg)) {
1913 /* error or limit violation */
1914 retval = IP_FW_DENY;
1915 l = 0; /* exit inner loop */
1916 done = 1; /* exit outer loop */
1917 }
1918 match = 1;
1919 break;
1920
1921 case O_PROBE_STATE:
1922 case O_CHECK_STATE:
1923 /*
1924 * dynamic rules are checked at the first
1925 * keep-state or check-state occurrence,
1926 * with the result being stored in dyn_dir.
1927 * The compiler introduces a PROBE_STATE
1928 * instruction for us when we have a
1929 * KEEP_STATE (because PROBE_STATE needs
1930 * to be run first).
1931 */
1932 if (dyn_dir == MATCH_UNKNOWN &&
1933 (q = ipfw_lookup_dyn_rule(&args->f_id,
1934 &dyn_dir, proto == IPPROTO_TCP ?
1935 TCP(ulp) : NULL))
1936 != NULL) {
1937 /*
1938 * Found dynamic entry, update stats
1939 * and jump to the 'action' part of
1940 * the parent rule by setting
1941 * f, cmd, l and clearing cmdlen.
1942 */
1943 q->pcnt++;
1944 q->bcnt += pktlen;
1945 /* XXX we would like to have f_pos
1946 * readily accessible in the dynamic
1947 * rule, instead of having to
1948 * lookup q->rule.
1949 */
1950 f = q->rule;
1951 f_pos = ipfw_find_rule(chain,
1952 f->rulenum, f->id);
1953 cmd = ACTION_PTR(f);
1954 l = f->cmd_len - f->act_ofs;
1955 ipfw_dyn_unlock();
1956 cmdlen = 0;
1957 match = 1;
1958 break;
1959 }
1960 /*
1961 * Dynamic entry not found. If CHECK_STATE,
1962 * skip to next rule, if PROBE_STATE just
1963 * ignore and continue with next opcode.
1964 */
1965 if (cmd->opcode == O_CHECK_STATE)
1966 l = 0; /* exit inner loop */
1967 match = 1;
1968 break;
1969
1970 case O_ACCEPT:
1971 retval = 0; /* accept */
1972 l = 0; /* exit inner loop */
1973 done = 1; /* exit outer loop */
1974 break;
1975
1976 case O_PIPE:
1977 case O_QUEUE:
1978 set_match(args, f_pos, chain);
1979 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
1980 tablearg : cmd->arg1;
1981 if (cmd->opcode == O_PIPE)
1982 args->rule.info |= IPFW_IS_PIPE;
1983 if (V_fw_one_pass)
1984 args->rule.info |= IPFW_ONEPASS;
1985 retval = IP_FW_DUMMYNET;
1986 l = 0; /* exit inner loop */
1987 done = 1; /* exit outer loop */
1988 break;
1989
1990 case O_DIVERT:
1991 case O_TEE:
1992 if (args->eh) /* not on layer 2 */
1993 break;
1994 /* otherwise this is terminal */
1995 l = 0; /* exit inner loop */
1996 done = 1; /* exit outer loop */
1997 retval = (cmd->opcode == O_DIVERT) ?
1998 IP_FW_DIVERT : IP_FW_TEE;
1999 set_match(args, f_pos, chain);
2000 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2001 tablearg : cmd->arg1;
2002 break;
2003
2004 case O_COUNT:
2005 f->pcnt++; /* update stats */
2006 f->bcnt += pktlen;
2007 f->timestamp = time_uptime;
2008 l = 0; /* exit inner loop */
2009 break;
2010
2011 case O_SKIPTO:
2012 f->pcnt++; /* update stats */
2013 f->bcnt += pktlen;
2014 f->timestamp = time_uptime;
2015 /* If possible use cached f_pos (in f->next_rule),
2016 * whose version is written in f->next_rule
2017 * (horrible hacks to avoid changing the ABI).
2018 */
2019 if (cmd->arg1 != IP_FW_TABLEARG &&
2020 (uintptr_t)f->x_next == chain->id) {
2021 f_pos = (uintptr_t)f->next_rule;
2022 } else {
2023 int i = (cmd->arg1 == IP_FW_TABLEARG) ?
2024 tablearg : cmd->arg1;
2025 /* make sure we do not jump backward */
2026 if (i <= f->rulenum)
2027 i = f->rulenum + 1;
2028 f_pos = ipfw_find_rule(chain, i, 0);
2029 /* update the cache */
2030 if (cmd->arg1 != IP_FW_TABLEARG) {
2031 f->next_rule =
2032 (void *)(uintptr_t)f_pos;
2033 f->x_next =
2034 (void *)(uintptr_t)chain->id;
2035 }
2036 }
2037 /*
2038 * Skip disabled rules, and re-enter
2039 * the inner loop with the correct
2040 * f_pos, f, l and cmd.
2041 * Also clear cmdlen and skip_or
2042 */
2043 for (; f_pos < chain->n_rules - 1 &&
2044 (V_set_disable &
2045 (1 << chain->map[f_pos]->set));
2046 f_pos++)
2047 ;
2048 /* Re-enter the inner loop at the skipto rule. */
2049 f = chain->map[f_pos];
2050 l = f->cmd_len;
2051 cmd = f->cmd;
2052 match = 1;
2053 cmdlen = 0;
2054 skip_or = 0;
2055 continue;
2056 break; /* not reached */
2057
2058 case O_REJECT:
2059 /*
2060 * Drop the packet and send a reject notice
2061 * if the packet is not ICMP (or is an ICMP
2062 * query), and it is not multicast/broadcast.
2063 */
2064 if (hlen > 0 && is_ipv4 && offset == 0 &&
2065 (proto != IPPROTO_ICMP ||
2066 is_icmp_query(ICMP(ulp))) &&
2067 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2068 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2069 send_reject(args, cmd->arg1, iplen, ip);
2070 m = args->m;
2071 }
2072 /* FALLTHROUGH */
2073#ifdef INET6
2074 case O_UNREACH6:
2075 if (hlen > 0 && is_ipv6 &&
2076 ((offset & IP6F_OFF_MASK) == 0) &&
2077 (proto != IPPROTO_ICMPV6 ||
2078 (is_icmp6_query(icmp6_type) == 1)) &&
2079 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2080 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2081 send_reject6(
2082 args, cmd->arg1, hlen,
2083 (struct ip6_hdr *)ip);
2084 m = args->m;
2085 }
2086 /* FALLTHROUGH */
2087#endif
2088 case O_DENY:
2089 retval = IP_FW_DENY;
2090 l = 0; /* exit inner loop */
2091 done = 1; /* exit outer loop */
2092 break;
2093
2094 case O_FORWARD_IP:
2095 if (args->eh) /* not valid on layer2 pkts */
2096 break;
2097 if (!q || dyn_dir == MATCH_FORWARD) {
2098 struct sockaddr_in *sa;
2099 sa = &(((ipfw_insn_sa *)cmd)->sa);
2100 if (sa->sin_addr.s_addr == INADDR_ANY) {
2101 bcopy(sa, &args->hopstore,
2102 sizeof(*sa));
2103 args->hopstore.sin_addr.s_addr =
2104 htonl(tablearg);
2105 args->next_hop = &args->hopstore;
2106 } else {
2107 args->next_hop = sa;
2108 }
2109 }
2110 retval = IP_FW_PASS;
2111 l = 0; /* exit inner loop */
2112 done = 1; /* exit outer loop */
2113 break;
2114
2115 case O_NETGRAPH:
2116 case O_NGTEE:
2117 set_match(args, f_pos, chain);
2118 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2119 tablearg : cmd->arg1;
2120 if (V_fw_one_pass)
2121 args->rule.info |= IPFW_ONEPASS;
2122 retval = (cmd->opcode == O_NETGRAPH) ?
2123 IP_FW_NETGRAPH : IP_FW_NGTEE;
2124 l = 0; /* exit inner loop */
2125 done = 1; /* exit outer loop */
2126 break;
2127
2128 case O_SETFIB:
2129 f->pcnt++; /* update stats */
2130 f->bcnt += pktlen;
2131 f->timestamp = time_uptime;
2132 M_SETFIB(m, cmd->arg1);
2133 args->f_id.fib = cmd->arg1;
2134 l = 0; /* exit inner loop */
2135 break;
2136
2137 case O_NAT:
2138 if (!IPFW_NAT_LOADED) {
2139 retval = IP_FW_DENY;
2140 } else {
2141 struct cfg_nat *t;
2142 int nat_id;
2143
2144 set_match(args, f_pos, chain);
2145 t = ((ipfw_insn_nat *)cmd)->nat;
2146 if (t == NULL) {
2147 nat_id = (cmd->arg1 == IP_FW_TABLEARG) ?
2148 tablearg : cmd->arg1;
2149 t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2150
2151 if (t == NULL) {
2152 retval = IP_FW_DENY;
2153 l = 0; /* exit inner loop */
2154 done = 1; /* exit outer loop */
2155 break;
2156 }
2157 if (cmd->arg1 != IP_FW_TABLEARG)
2158 ((ipfw_insn_nat *)cmd)->nat = t;
2159 }
2160 retval = ipfw_nat_ptr(args, t, m);
2161 }
2162 l = 0; /* exit inner loop */
2163 done = 1; /* exit outer loop */
2164 break;
2165
2166 case O_REASS: {
2167 int ip_off;
2168
2169 f->pcnt++;
2170 f->bcnt += pktlen;
2171 l = 0; /* in any case exit inner loop */
2172 ip_off = ntohs(ip->ip_off);
2173
2174 /* if not fragmented, go to next rule */
2175 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2176 break;
2177 /*
2178 * ip_reass() expects len & off in host
2179 * byte order.
2180 */
2181 SET_HOST_IPLEN(ip);
2182
2183 args->m = m = ip_reass(m);
2184
2185 /*
2186 * do IP header checksum fixup.
2187 */
2188 if (m == NULL) { /* fragment got swallowed */
2189 retval = IP_FW_DENY;
2190 } else { /* good, packet complete */
2191 int hlen;
2192
2193 ip = mtod(m, struct ip *);
2194 hlen = ip->ip_hl << 2;
2195 SET_NET_IPLEN(ip);
2196 ip->ip_sum = 0;
2197 if (hlen == sizeof(struct ip))
2198 ip->ip_sum = in_cksum_hdr(ip);
2199 else
2200 ip->ip_sum = in_cksum(m, hlen);
2201 retval = IP_FW_REASS;
2202 set_match(args, f_pos, chain);
2203 }
2204 done = 1; /* exit outer loop */
2205 break;
2206 }
2207
2208 default:
2209 panic("-- unknown opcode %d\n", cmd->opcode);
2210 } /* end of switch() on opcodes */
2211 /*
2212 * if we get here with l=0, then match is irrelevant.
2213 */
2214
2215 if (cmd->len & F_NOT)
2216 match = !match;
2217
2218 if (match) {
2219 if (cmd->len & F_OR)
2220 skip_or = 1;
2221 } else {
2222 if (!(cmd->len & F_OR)) /* not an OR block, */
2223 break; /* try next rule */
2224 }
2225
2226 } /* end of inner loop, scan opcodes */
2227
2228 if (done)
2229 break;
2230
2231/* next_rule:; */ /* try next rule */
2232
2233 } /* end of outer for, scan rules */
2234
2235 if (done) {
2236 struct ip_fw *rule = chain->map[f_pos];
2237 /* Update statistics */
2238 rule->pcnt++;
2239 rule->bcnt += pktlen;
2240 rule->timestamp = time_uptime;
2241 } else {
2242 retval = IP_FW_DENY;
2243 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2244 }
2245 IPFW_RUNLOCK(chain);
2246#ifdef __FreeBSD__
2247 if (ucred_cache != NULL)
2248 crfree(ucred_cache);
2249#endif
2250 return (retval);
2251
2252pullup_failed:
2253 if (V_fw_verbose)
2254 printf("ipfw: pullup failed\n");
2255 return (IP_FW_DENY);
2256}
2257
2258/*
2259 * Module and VNET glue
2260 */
2261
2262/*
2263 * Stuff that must be initialised only on boot or module load
2264 */
2265static int
2266ipfw_init(void)
2267{
2268 int error = 0;
2269
2270 ipfw_dyn_attach();
2271 /*
2272 * Only print out this stuff the first time around,
2273 * when called from the sysinit code.
2274 */
2275 printf("ipfw2 "
2276#ifdef INET6
2277 "(+ipv6) "
2278#endif
2279 "initialized, divert %s, nat %s, "
2280 "rule-based forwarding "
2281#ifdef IPFIREWALL_FORWARD
2282 "enabled, "
2283#else
2284 "disabled, "
2285#endif
2286 "default to %s, logging ",
2287#ifdef IPDIVERT
2288 "enabled",
2289#else
2290 "loadable",
2291#endif
2292#ifdef IPFIREWALL_NAT
2293 "enabled",
2294#else
2295 "loadable",
2296#endif
2297 default_to_accept ? "accept" : "deny");
2298
2299 /*
2300 * Note: V_xxx variables can be accessed here but the vnet specific
2301 * initializer may not have been called yet for the VIMAGE case.
2302 * Tuneables will have been processed. We will print out values for
2303 * the default vnet.
2304 * XXX This should all be rationalized AFTER 8.0
2305 */
2306 if (V_fw_verbose == 0)
2307 printf("disabled\n");
2308 else if (V_verbose_limit == 0)
2309 printf("unlimited\n");
2310 else
2311 printf("limited to %d packets/entry by default\n",
2312 V_verbose_limit);
2313
2314 ipfw_log_bpf(1); /* init */
2315 return (error);
2316}
2317
2318/*
2319 * Called for the removal of the last instance only on module unload.
2320 */
2321static void
2322ipfw_destroy(void)
2323{
2324
2325 ipfw_log_bpf(0); /* uninit */
2326 ipfw_dyn_detach();
2327 printf("IP firewall unloaded\n");
2328}
2329
2330/*
2331 * Stuff that must be initialized for every instance
2332 * (including the first of course).
2333 */
2334static int
2335vnet_ipfw_init(const void *unused)
2336{
2337 int error;
2338 struct ip_fw *rule = NULL;
2339 struct ip_fw_chain *chain;
2340
2341 chain = &V_layer3_chain;
2342
2343 /* First set up some values that are compile time options */
2344 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
2345 V_fw_deny_unknown_exthdrs = 1;
2346#ifdef IPFIREWALL_VERBOSE
2347 V_fw_verbose = 1;
2348#endif
2349#ifdef IPFIREWALL_VERBOSE_LIMIT
2350 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2351#endif
2352#ifdef IPFIREWALL_NAT
2353 LIST_INIT(&chain->nat);
2354#endif
2355
2356 /* insert the default rule and create the initial map */
2357 chain->n_rules = 1;
2358 chain->static_len = sizeof(struct ip_fw);
2359 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_NOWAIT | M_ZERO);
2360 if (chain->map)
2361 rule = malloc(chain->static_len, M_IPFW, M_NOWAIT | M_ZERO);
2362 if (rule == NULL) {
2363 if (chain->map)
2364 free(chain->map, M_IPFW);
2365 printf("ipfw2: ENOSPC initializing default rule "
2366 "(support disabled)\n");
2367 return (ENOSPC);
2368 }
2369 error = ipfw_init_tables(chain);
2370 if (error) {
2371 panic("init_tables"); /* XXX Marko fix this ! */
2372 }
2373
2374 /* fill and insert the default rule */
2375 rule->act_ofs = 0;
2376 rule->rulenum = IPFW_DEFAULT_RULE;
2377 rule->cmd_len = 1;
2378 rule->set = RESVD_SET;
2379 rule->cmd[0].len = 1;
2380 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2381 chain->rules = chain->default_rule = chain->map[0] = rule;
2382 chain->id = rule->id = 1;
2383
2384 IPFW_LOCK_INIT(chain);
2385 ipfw_dyn_init();
2386
2387 /* First set up some values that are compile time options */
2388 V_ipfw_vnet_ready = 1; /* Open for business */
2389
2390 /*
2391 * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr)
2392 * and pfil hooks for ipv4 and ipv6. Even if the latter two fail
2393 * we still keep the module alive because the sockopt and
2394 * layer2 paths are still useful.
2395 * ipfw[6]_hook return 0 on success, ENOENT on failure,
2396 * so we can ignore the exact return value and just set a flag.
2397 *
2398 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2399 * changes in the underlying (per-vnet) variables trigger
2400 * immediate hook()/unhook() calls.
2401 * In layer2 we have the same behaviour, except that V_ether_ipfw
2402 * is checked on each packet because there are no pfil hooks.
2403 */
2404 V_ip_fw_ctl_ptr = ipfw_ctl;
2405 V_ip_fw_chk_ptr = ipfw_chk;
2406 error = ipfw_attach_hooks(1);
2407 return (error);
2408}
2409
2410/*
2411 * Called for the removal of each instance.
2412 */
2413static int
2414vnet_ipfw_uninit(const void *unused)
2415{
2416 struct ip_fw *reap, *rule;
2417 struct ip_fw_chain *chain = &V_layer3_chain;
2418 int i;
2419
2420 V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2421 /*
2422 * disconnect from ipv4, ipv6, layer2 and sockopt.
2423 * Then grab, release and grab again the WLOCK so we make
2424 * sure the update is propagated and nobody will be in.
2425 */
2426 (void)ipfw_attach_hooks(0 /* detach */);
2427 V_ip_fw_chk_ptr = NULL;
2428 V_ip_fw_ctl_ptr = NULL;
2429 IPFW_UH_WLOCK(chain);
2430 IPFW_UH_WUNLOCK(chain);
2431 IPFW_UH_WLOCK(chain);
2432
2433 IPFW_WLOCK(chain);
2434 IPFW_WUNLOCK(chain);
2435 IPFW_WLOCK(chain);
2436
2437 ipfw_dyn_uninit(0); /* run the callout_drain */
2438 ipfw_destroy_tables(chain);
2439 reap = NULL;
2440 for (i = 0; i < chain->n_rules; i++) {
2441 rule = chain->map[i];
2442 rule->x_next = reap;
2443 reap = rule;
2444 }
2445 if (chain->map)
2446 free(chain->map, M_IPFW);
2447 IPFW_WUNLOCK(chain);
2448 IPFW_UH_WUNLOCK(chain);
2449 if (reap != NULL)
2450 ipfw_reap_rules(reap);
2451 IPFW_LOCK_DESTROY(chain);
2452 ipfw_dyn_uninit(1); /* free the remaining parts */
2453 return 0;
2454}
2455
2456/*
2457 * Module event handler.
2458 * In general we have the choice of handling most of these events by the
2459 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2460 * use the SYSINIT handlers as they are more capable of expressing the
2461 * flow of control during module and vnet operations, so this is just
2462 * a skeleton. Note there is no SYSINIT equivalent of the module
2463 * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2464 */
2465static int
2466ipfw_modevent(module_t mod, int type, void *unused)
2467{
2468 int err = 0;
2469
2470 switch (type) {
2471 case MOD_LOAD:
2472 /* Called once at module load or
2473 * system boot if compiled in. */
2474 break;
2475 case MOD_QUIESCE:
2476 /* Called before unload. May veto unloading. */
2477 break;
2478 case MOD_UNLOAD:
2479 /* Called during unload. */
2480 break;
2481 case MOD_SHUTDOWN:
2482 /* Called during system shutdown. */
2483 break;
2484 default:
2485 err = EOPNOTSUPP;
2486 break;
2487 }
2488 return err;
2489}
2490
2491static moduledata_t ipfwmod = {
2492 "ipfw",
2493 ipfw_modevent,
2494 0
2495};
2496
2497/* Define startup order. */
2498#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN
2499#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */
2500#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2501#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2502
2503DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2504MODULE_VERSION(ipfw, 2);
2505/* should declare some dependencies here */
2506
2507/*
2508 * Starting up. Done in order after ipfwmod() has been called.
2509 * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2510 */
2511SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2512 ipfw_init, NULL);
2513VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2514 vnet_ipfw_init, NULL);
2515
2516/*
2517 * Closing up shop. These are done in REVERSE ORDER, but still
2518 * after ipfwmod() has been called. Not called on reboot.
2519 * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2520 * or when the module is unloaded.
2521 */
2522SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2523 ipfw_destroy, NULL);
2524VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2525 vnet_ipfw_uninit, NULL);
2526/* end of file */
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