2 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * $FreeBSD: src/sys/netinet/ip_fw2.c,v 1.6.2.12 2003/04/08 10:42:32 maxim Exp $
26 * $DragonFly: src/sys/net/ipfw/ip_fw2.c,v 1.12 2004/06/02 14:42:58 eirikn Exp $
33 * Implement IP packet firewall (new version)
36 #if !defined(KLD_MODULE)
39 #include "opt_ipdivert.h"
42 #error IPFIREWALL requires INET.
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/malloc.h>
51 #include <sys/kernel.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/sysctl.h>
56 #include <sys/syslog.h>
57 #include <sys/ucred.h>
58 #include <sys/in_cksum.h>
60 #include <net/route.h>
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/in_var.h>
64 #include <netinet/in_pcb.h>
65 #include <netinet/ip.h>
66 #include <netinet/ip_var.h>
67 #include <netinet/ip_icmp.h>
69 #include <net/dummynet/ip_dummynet.h>
70 #include <netinet/tcp.h>
71 #include <netinet/tcp_timer.h>
72 #include <netinet/tcp_var.h>
73 #include <netinet/tcpip.h>
74 #include <netinet/udp.h>
75 #include <netinet/udp_var.h>
77 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
80 * XXX This one should go in sys/mbuf.h. It is used to avoid that
81 * a firewall-generated packet loops forever through the firewall.
83 #ifndef M_SKIP_FIREWALL
84 #define M_SKIP_FIREWALL 0x4000
88 * set_disable contains one bit per set value (0..31).
89 * If the bit is set, all rules with the corresponding set
90 * are disabled. Set 31 is reserved for the default rule
91 * and CANNOT be disabled.
93 static u_int32_t set_disable;
95 static int fw_verbose;
96 static int verbose_limit;
98 static struct callout_handle ipfw_timeout_h;
99 #define IPFW_DEFAULT_RULE 65535
102 * list of rules for layer 3
104 static struct ip_fw *layer3_chain;
106 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
108 static int fw_debug = 1;
109 static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
112 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
113 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_RW,
114 &fw_enable, 0, "Enable ipfw");
115 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW,
116 &autoinc_step, 0, "Rule number autincrement step");
117 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
119 "Only do a single pass through ipfw when using dummynet(4)");
120 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
121 &fw_debug, 0, "Enable printing of debug ip_fw statements");
122 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
123 &fw_verbose, 0, "Log matches to ipfw rules");
124 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
125 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
128 * Description of dynamic rules.
130 * Dynamic rules are stored in lists accessed through a hash table
131 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
132 * be modified through the sysctl variable dyn_buckets which is
133 * updated when the table becomes empty.
135 * XXX currently there is only one list, ipfw_dyn.
137 * When a packet is received, its address fields are first masked
138 * with the mask defined for the rule, then hashed, then matched
139 * against the entries in the corresponding list.
140 * Dynamic rules can be used for different purposes:
142 * + enforcing limits on the number of sessions;
143 * + in-kernel NAT (not implemented yet)
145 * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
146 * measured in seconds and depending on the flags.
148 * The total number of dynamic rules is stored in dyn_count.
149 * The max number of dynamic rules is dyn_max. When we reach
150 * the maximum number of rules we do not create anymore. This is
151 * done to avoid consuming too much memory, but also too much
152 * time when searching on each packet (ideally, we should try instead
153 * to put a limit on the length of the list on each bucket...).
155 * Each dynamic rule holds a pointer to the parent ipfw rule so
156 * we know what action to perform. Dynamic rules are removed when
157 * the parent rule is deleted. XXX we should make them survive.
159 * There are some limitations with dynamic rules -- we do not
160 * obey the 'randomized match', and we do not do multiple
161 * passes through the firewall. XXX check the latter!!!
163 static ipfw_dyn_rule **ipfw_dyn_v = NULL;
164 static u_int32_t dyn_buckets = 256; /* must be power of 2 */
165 static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */
168 * Timeouts for various events in handing dynamic rules.
170 static u_int32_t dyn_ack_lifetime = 300;
171 static u_int32_t dyn_syn_lifetime = 20;
172 static u_int32_t dyn_fin_lifetime = 1;
173 static u_int32_t dyn_rst_lifetime = 1;
174 static u_int32_t dyn_udp_lifetime = 10;
175 static u_int32_t dyn_short_lifetime = 5;
178 * Keepalives are sent if dyn_keepalive is set. They are sent every
179 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
180 * seconds of lifetime of a rule.
181 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
182 * than dyn_keepalive_period.
185 static u_int32_t dyn_keepalive_interval = 20;
186 static u_int32_t dyn_keepalive_period = 5;
187 static u_int32_t dyn_keepalive = 1; /* do send keepalives */
189 static u_int32_t static_count; /* # of static rules */
190 static u_int32_t static_len; /* size in bytes of static rules */
191 static u_int32_t dyn_count; /* # of dynamic rules */
192 static u_int32_t dyn_max = 4096; /* max # of dynamic rules */
194 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
195 &dyn_buckets, 0, "Number of dyn. buckets");
196 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
197 &curr_dyn_buckets, 0, "Current Number of dyn. buckets");
198 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
199 &dyn_count, 0, "Number of dyn. rules");
200 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
201 &dyn_max, 0, "Max number of dyn. rules");
202 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
203 &static_count, 0, "Number of static rules");
204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
205 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
206 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
207 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
208 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
209 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
210 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
211 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
212 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
213 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
214 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
215 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
216 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
217 &dyn_keepalive, 0, "Enable keepalives for dyn. rules");
219 #endif /* SYSCTL_NODE */
222 static ip_fw_chk_t ipfw_chk;
224 ip_dn_ruledel_t *ip_dn_ruledel_ptr = NULL; /* hook into dummynet */
227 * This macro maps an ip pointer into a layer3 header pointer of type T
229 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
232 icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd)
234 int type = L3HDR(struct icmp,ip)->icmp_type;
236 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
239 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
240 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
243 is_icmp_query(struct ip *ip)
245 int type = L3HDR(struct icmp, ip)->icmp_type;
246 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
251 * The following checks use two arrays of 8 or 16 bits to store the
252 * bits that we want set or clear, respectively. They are in the
253 * low and high half of cmd->arg1 or cmd->d[0].
255 * We scan options and store the bits we find set. We succeed if
257 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
259 * The code is sometimes optimized not to store additional variables.
263 flags_match(ipfw_insn *cmd, u_int8_t bits)
268 if ( ((cmd->arg1 & 0xff) & bits) != 0)
269 return 0; /* some bits we want set were clear */
270 want_clear = (cmd->arg1 >> 8) & 0xff;
271 if ( (want_clear & bits) != want_clear)
272 return 0; /* some bits we want clear were set */
277 ipopts_match(struct ip *ip, ipfw_insn *cmd)
279 int optlen, bits = 0;
280 u_char *cp = (u_char *)(ip + 1);
281 int x = (ip->ip_hl << 2) - sizeof (struct ip);
283 for (; x > 0; x -= optlen, cp += optlen) {
284 int opt = cp[IPOPT_OPTVAL];
286 if (opt == IPOPT_EOL)
288 if (opt == IPOPT_NOP)
291 optlen = cp[IPOPT_OLEN];
292 if (optlen <= 0 || optlen > x)
293 return 0; /* invalid or truncated */
301 bits |= IP_FW_IPOPT_LSRR;
305 bits |= IP_FW_IPOPT_SSRR;
309 bits |= IP_FW_IPOPT_RR;
313 bits |= IP_FW_IPOPT_TS;
317 return (flags_match(cmd, bits));
321 tcpopts_match(struct ip *ip, ipfw_insn *cmd)
323 int optlen, bits = 0;
324 struct tcphdr *tcp = L3HDR(struct tcphdr,ip);
325 u_char *cp = (u_char *)(tcp + 1);
326 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
328 for (; x > 0; x -= optlen, cp += optlen) {
330 if (opt == TCPOPT_EOL)
332 if (opt == TCPOPT_NOP)
346 bits |= IP_FW_TCPOPT_MSS;
350 bits |= IP_FW_TCPOPT_WINDOW;
353 case TCPOPT_SACK_PERMITTED:
355 bits |= IP_FW_TCPOPT_SACK;
358 case TCPOPT_TIMESTAMP:
359 bits |= IP_FW_TCPOPT_TS;
365 bits |= IP_FW_TCPOPT_CC;
369 return (flags_match(cmd, bits));
373 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
375 if (ifp == NULL) /* no iface with this packet, match fails */
377 /* Check by name or by IP address */
378 if (cmd->name[0] != '\0') { /* match by name */
381 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
384 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
390 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
391 if (ia->ifa_addr == NULL)
393 if (ia->ifa_addr->sa_family != AF_INET)
395 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
396 (ia->ifa_addr))->sin_addr.s_addr)
397 return(1); /* match */
400 return(0); /* no match, fail ... */
403 static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */
405 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
406 #define SNP(buf) buf, sizeof(buf)
409 * We enter here when we have a rule with O_LOG.
410 * XXX this function alone takes about 2Kbytes of code!
413 ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh,
414 struct mbuf *m, struct ifnet *oif)
417 int limit_reached = 0;
418 char action2[40], proto[48], fragment[28];
423 if (f == NULL) { /* bogus pkt */
424 if (verbose_limit != 0 && norule_counter >= verbose_limit)
427 if (norule_counter == verbose_limit)
428 limit_reached = verbose_limit;
430 } else { /* O_LOG is the first action, find the real one */
431 ipfw_insn *cmd = ACTION_PTR(f);
432 ipfw_insn_log *l = (ipfw_insn_log *)cmd;
434 if (l->max_log != 0 && l->log_left == 0)
437 if (l->log_left == 0)
438 limit_reached = l->max_log;
439 cmd += F_LEN(cmd); /* point to first action */
440 if (cmd->opcode == O_PROB)
444 switch (cmd->opcode) {
450 if (cmd->arg1==ICMP_REJECT_RST)
452 else if (cmd->arg1==ICMP_UNREACH_HOST)
455 snprintf(SNPARGS(action2, 0), "Unreach %d",
466 snprintf(SNPARGS(action2, 0), "Divert %d",
470 snprintf(SNPARGS(action2, 0), "Tee %d",
474 snprintf(SNPARGS(action2, 0), "SkipTo %d",
478 snprintf(SNPARGS(action2, 0), "Pipe %d",
482 snprintf(SNPARGS(action2, 0), "Queue %d",
486 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
489 len = snprintf(SNPARGS(action2, 0), "Forward to %s",
490 inet_ntoa(sa->sa.sin_addr));
492 snprintf(SNPARGS(action2, len), ":%d",
502 if (hlen == 0) { /* non-ip */
503 snprintf(SNPARGS(proto, 0), "MAC");
505 struct ip *ip = mtod(m, struct ip *);
506 /* these three are all aliases to the same thing */
507 struct icmp *const icmp = L3HDR(struct icmp, ip);
508 struct tcphdr *const tcp = (struct tcphdr *)icmp;
509 struct udphdr *const udp = (struct udphdr *)icmp;
511 int ip_off, offset, ip_len;
515 if (eh != NULL) { /* layer 2 packets are as on the wire */
516 ip_off = ntohs(ip->ip_off);
517 ip_len = ntohs(ip->ip_len);
522 offset = ip_off & IP_OFFMASK;
525 len = snprintf(SNPARGS(proto, 0), "TCP %s",
526 inet_ntoa(ip->ip_src));
528 snprintf(SNPARGS(proto, len), ":%d %s:%d",
529 ntohs(tcp->th_sport),
530 inet_ntoa(ip->ip_dst),
531 ntohs(tcp->th_dport));
533 snprintf(SNPARGS(proto, len), " %s",
534 inet_ntoa(ip->ip_dst));
538 len = snprintf(SNPARGS(proto, 0), "UDP %s",
539 inet_ntoa(ip->ip_src));
541 snprintf(SNPARGS(proto, len), ":%d %s:%d",
542 ntohs(udp->uh_sport),
543 inet_ntoa(ip->ip_dst),
544 ntohs(udp->uh_dport));
546 snprintf(SNPARGS(proto, len), " %s",
547 inet_ntoa(ip->ip_dst));
552 len = snprintf(SNPARGS(proto, 0),
554 icmp->icmp_type, icmp->icmp_code);
556 len = snprintf(SNPARGS(proto, 0), "ICMP ");
557 len += snprintf(SNPARGS(proto, len), "%s",
558 inet_ntoa(ip->ip_src));
559 snprintf(SNPARGS(proto, len), " %s",
560 inet_ntoa(ip->ip_dst));
564 len = snprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
565 inet_ntoa(ip->ip_src));
566 snprintf(SNPARGS(proto, len), " %s",
567 inet_ntoa(ip->ip_dst));
571 if (ip_off & (IP_MF | IP_OFFMASK))
572 snprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)",
573 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
575 (ip_off & IP_MF) ? "+" : "");
577 if (oif || m->m_pkthdr.rcvif)
578 log(LOG_SECURITY | LOG_INFO,
579 "ipfw: %d %s %s %s via %s%s\n",
581 action, proto, oif ? "out" : "in",
582 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
585 log(LOG_SECURITY | LOG_INFO,
586 "ipfw: %d %s %s [no if info]%s\n",
588 action, proto, fragment);
590 log(LOG_SECURITY | LOG_NOTICE,
591 "ipfw: limit %d reached on entry %d\n",
592 limit_reached, f ? f->rulenum : -1);
596 * IMPORTANT: the hash function for dynamic rules must be commutative
597 * in source and destination (ip,port), because rules are bidirectional
598 * and we want to find both in the same bucket.
601 hash_packet(struct ipfw_flow_id *id)
605 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
606 i &= (curr_dyn_buckets - 1);
611 * unlink a dynamic rule from a chain. prev is a pointer to
612 * the previous one, q is a pointer to the rule to delete,
613 * head is a pointer to the head of the queue.
614 * Modifies q and potentially also head.
616 #define UNLINK_DYN_RULE(prev, head, q) { \
617 ipfw_dyn_rule *old_q = q; \
619 /* remove a refcount to the parent */ \
620 if (q->dyn_type == O_LIMIT) \
621 q->parent->count--; \
622 DEB(printf("-- unlink entry 0x%08x %d -> 0x%08x %d, %d left\n", \
623 (q->id.src_ip), (q->id.src_port), \
624 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \
626 prev->next = q = q->next; \
628 head = q = q->next; \
630 free(old_q, M_IPFW); }
632 #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
635 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
637 * If keep_me == NULL, rules are deleted even if not expired,
638 * otherwise only expired rules are removed.
640 * The value of the second parameter is also used to point to identify
641 * a rule we absolutely do not want to remove (e.g. because we are
642 * holding a reference to it -- this is the case with O_LIMIT_PARENT
643 * rules). The pointer is only used for comparison, so any non-null
647 remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
649 static u_int32_t last_remove = 0;
651 #define FORCE (keep_me == NULL)
653 ipfw_dyn_rule *prev, *q;
654 int i, pass = 0, max_pass = 0;
656 if (ipfw_dyn_v == NULL || dyn_count == 0)
658 /* do not expire more than once per second, it is useless */
659 if (!FORCE && last_remove == time_second)
661 last_remove = time_second;
664 * because O_LIMIT refer to parent rules, during the first pass only
665 * remove child and mark any pending LIMIT_PARENT, and remove
666 * them in a second pass.
669 for (i = 0 ; i < curr_dyn_buckets ; i++) {
670 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) {
672 * Logic can become complex here, so we split tests.
676 if (rule != NULL && rule != q->rule)
677 goto next; /* not the one we are looking for */
678 if (q->dyn_type == O_LIMIT_PARENT) {
680 * handle parent in the second pass,
681 * record we need one.
686 if (FORCE && q->count != 0 ) {
687 /* XXX should not happen! */
688 printf( "OUCH! cannot remove rule,"
689 " count %d\n", q->count);
693 !TIME_LEQ( q->expire, time_second ))
696 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
703 if (pass++ < max_pass)
709 * lookup a dynamic rule.
711 static ipfw_dyn_rule *
712 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
716 * stateful ipfw extensions.
717 * Lookup into dynamic session queue
719 #define MATCH_REVERSE 0
720 #define MATCH_FORWARD 1
722 #define MATCH_UNKNOWN 3
723 int i, dir = MATCH_NONE;
724 ipfw_dyn_rule *prev, *q=NULL;
726 if (ipfw_dyn_v == NULL)
727 goto done; /* not found */
728 i = hash_packet( pkt );
729 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) {
730 if (q->dyn_type == O_LIMIT_PARENT)
732 if (TIME_LEQ( q->expire, time_second)) { /* expire entry */
733 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
736 if ( pkt->proto == q->id.proto) {
737 if (pkt->src_ip == q->id.src_ip &&
738 pkt->dst_ip == q->id.dst_ip &&
739 pkt->src_port == q->id.src_port &&
740 pkt->dst_port == q->id.dst_port ) {
744 if (pkt->src_ip == q->id.dst_ip &&
745 pkt->dst_ip == q->id.src_ip &&
746 pkt->src_port == q->id.dst_port &&
747 pkt->dst_port == q->id.src_port ) {
757 goto done; /* q = NULL, not found */
759 if ( prev != NULL) { /* found and not in front */
760 prev->next = q->next;
761 q->next = ipfw_dyn_v[i];
764 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
765 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
767 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
768 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
769 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
771 case TH_SYN: /* opening */
772 q->expire = time_second + dyn_syn_lifetime;
775 case BOTH_SYN: /* move to established */
776 case BOTH_SYN | TH_FIN : /* one side tries to close */
777 case BOTH_SYN | (TH_FIN << 8) :
779 #define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0)
780 u_int32_t ack = ntohl(tcp->th_ack);
781 if (dir == MATCH_FORWARD) {
782 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd))
784 else { /* ignore out-of-sequence */
788 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev))
790 else { /* ignore out-of-sequence */
795 q->expire = time_second + dyn_ack_lifetime;
798 case BOTH_SYN | BOTH_FIN: /* both sides closed */
799 if (dyn_fin_lifetime >= dyn_keepalive_period)
800 dyn_fin_lifetime = dyn_keepalive_period - 1;
801 q->expire = time_second + dyn_fin_lifetime;
807 * reset or some invalid combination, but can also
808 * occur if we use keep-state the wrong way.
810 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
811 printf("invalid state: 0x%x\n", q->state);
813 if (dyn_rst_lifetime >= dyn_keepalive_period)
814 dyn_rst_lifetime = dyn_keepalive_period - 1;
815 q->expire = time_second + dyn_rst_lifetime;
818 } else if (pkt->proto == IPPROTO_UDP) {
819 q->expire = time_second + dyn_udp_lifetime;
821 /* other protocols */
822 q->expire = time_second + dyn_short_lifetime;
826 *match_direction = dir;
831 realloc_dynamic_table(void)
834 * Try reallocation, make sure we have a power of 2 and do
835 * not allow more than 64k entries. In case of overflow,
839 if (dyn_buckets > 65536)
841 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */
842 dyn_buckets = curr_dyn_buckets; /* reset */
845 curr_dyn_buckets = dyn_buckets;
846 if (ipfw_dyn_v != NULL)
847 free(ipfw_dyn_v, M_IPFW);
849 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
850 M_IPFW, M_WAITOK | M_ZERO);
851 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
853 curr_dyn_buckets /= 2;
858 * Install state of type 'type' for a dynamic session.
859 * The hash table contains two type of rules:
860 * - regular rules (O_KEEP_STATE)
861 * - rules for sessions with limited number of sess per user
862 * (O_LIMIT). When they are created, the parent is
863 * increased by 1, and decreased on delete. In this case,
864 * the third parameter is the parent rule and not the chain.
865 * - "parent" rules for the above (O_LIMIT_PARENT).
867 static ipfw_dyn_rule *
868 add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule)
873 if (ipfw_dyn_v == NULL ||
874 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
875 realloc_dynamic_table();
876 if (ipfw_dyn_v == NULL)
877 return NULL; /* failed ! */
881 r = malloc(sizeof *r, M_IPFW, M_WAITOK | M_ZERO);
883 printf ("sorry cannot allocate state\n");
887 /* increase refcount on parent, and set pointer */
888 if (dyn_type == O_LIMIT) {
889 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
890 if ( parent->dyn_type != O_LIMIT_PARENT)
891 panic("invalid parent");
898 r->expire = time_second + dyn_syn_lifetime;
900 r->dyn_type = dyn_type;
901 r->pcnt = r->bcnt = 0;
905 r->next = ipfw_dyn_v[i];
908 DEB(printf("-- add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
910 (r->id.src_ip), (r->id.src_port),
911 (r->id.dst_ip), (r->id.dst_port),
917 * lookup dynamic parent rule using pkt and rule as search keys.
918 * If the lookup fails, then install one.
920 static ipfw_dyn_rule *
921 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
927 i = hash_packet( pkt );
928 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next)
929 if (q->dyn_type == O_LIMIT_PARENT &&
931 pkt->proto == q->id.proto &&
932 pkt->src_ip == q->id.src_ip &&
933 pkt->dst_ip == q->id.dst_ip &&
934 pkt->src_port == q->id.src_port &&
935 pkt->dst_port == q->id.dst_port) {
936 q->expire = time_second + dyn_short_lifetime;
937 DEB(printf("lookup_dyn_parent found 0x%p\n",q);)
941 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
945 * Install dynamic state for rule type cmd->o.opcode
947 * Returns 1 (failure) if state is not installed because of errors or because
948 * session limitations are enforced.
951 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
952 struct ip_fw_args *args)
958 DEB(printf("-- install state type %d 0x%08x %u -> 0x%08x %u\n",
960 (args->f_id.src_ip), (args->f_id.src_port),
961 (args->f_id.dst_ip), (args->f_id.dst_port) );)
963 q = lookup_dyn_rule(&args->f_id, NULL, NULL);
965 if (q != NULL) { /* should never occur */
966 if (last_log != time_second) {
967 last_log = time_second;
968 printf(" install_state: entry already present, done\n");
973 if (dyn_count >= dyn_max)
975 * Run out of slots, try to remove any expired rule.
977 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1);
979 if (dyn_count >= dyn_max) {
980 if (last_log != time_second) {
981 last_log = time_second;
982 printf("install_state: Too many dynamic rules\n");
984 return 1; /* cannot install, notify caller */
987 switch (cmd->o.opcode) {
988 case O_KEEP_STATE: /* bidir rule */
989 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule);
992 case O_LIMIT: /* limit number of sessions */
994 u_int16_t limit_mask = cmd->limit_mask;
995 struct ipfw_flow_id id;
996 ipfw_dyn_rule *parent;
998 DEB(printf("installing dyn-limit rule %d\n", cmd->conn_limit);)
1000 id.dst_ip = id.src_ip = 0;
1001 id.dst_port = id.src_port = 0;
1002 id.proto = args->f_id.proto;
1004 if (limit_mask & DYN_SRC_ADDR)
1005 id.src_ip = args->f_id.src_ip;
1006 if (limit_mask & DYN_DST_ADDR)
1007 id.dst_ip = args->f_id.dst_ip;
1008 if (limit_mask & DYN_SRC_PORT)
1009 id.src_port = args->f_id.src_port;
1010 if (limit_mask & DYN_DST_PORT)
1011 id.dst_port = args->f_id.dst_port;
1012 parent = lookup_dyn_parent(&id, rule);
1013 if (parent == NULL) {
1014 printf("add parent failed\n");
1017 if (parent->count >= cmd->conn_limit) {
1019 * See if we can remove some expired rule.
1021 remove_dyn_rule(rule, parent);
1022 if (parent->count >= cmd->conn_limit) {
1023 if (fw_verbose && last_log != time_second) {
1024 last_log = time_second;
1025 log(LOG_SECURITY | LOG_DEBUG,
1026 "drop session, too many entries\n");
1031 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent);
1035 printf("unknown dynamic rule type %u\n", cmd->o.opcode);
1038 lookup_dyn_rule(&args->f_id, NULL, NULL); /* XXX just set lifetime */
1043 * Transmit a TCP packet, containing either a RST or a keepalive.
1044 * When flags & TH_RST, we are sending a RST packet, because of a
1045 * "reset" action matched the packet.
1046 * Otherwise we are sending a keepalive, and flags & TH_
1049 send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags)
1054 struct route sro; /* fake route */
1056 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1059 m->m_pkthdr.rcvif = (struct ifnet *)0;
1060 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
1061 m->m_data += max_linkhdr;
1063 ip = mtod(m, struct ip *);
1064 bzero(ip, m->m_len);
1065 tcp = (struct tcphdr *)(ip + 1); /* no IP options */
1066 ip->ip_p = IPPROTO_TCP;
1069 * Assume we are sending a RST (or a keepalive in the reverse
1070 * direction), swap src and destination addresses and ports.
1072 ip->ip_src.s_addr = htonl(id->dst_ip);
1073 ip->ip_dst.s_addr = htonl(id->src_ip);
1074 tcp->th_sport = htons(id->dst_port);
1075 tcp->th_dport = htons(id->src_port);
1076 if (flags & TH_RST) { /* we are sending a RST */
1077 if (flags & TH_ACK) {
1078 tcp->th_seq = htonl(ack);
1079 tcp->th_ack = htonl(0);
1080 tcp->th_flags = TH_RST;
1084 tcp->th_seq = htonl(0);
1085 tcp->th_ack = htonl(seq);
1086 tcp->th_flags = TH_RST | TH_ACK;
1090 * We are sending a keepalive. flags & TH_SYN determines
1091 * the direction, forward if set, reverse if clear.
1092 * NOTE: seq and ack are always assumed to be correct
1093 * as set by the caller. This may be confusing...
1095 if (flags & TH_SYN) {
1097 * we have to rewrite the correct addresses!
1099 ip->ip_dst.s_addr = htonl(id->dst_ip);
1100 ip->ip_src.s_addr = htonl(id->src_ip);
1101 tcp->th_dport = htons(id->dst_port);
1102 tcp->th_sport = htons(id->src_port);
1104 tcp->th_seq = htonl(seq);
1105 tcp->th_ack = htonl(ack);
1106 tcp->th_flags = TH_ACK;
1109 * set ip_len to the payload size so we can compute
1110 * the tcp checksum on the pseudoheader
1111 * XXX check this, could save a couple of words ?
1113 ip->ip_len = htons(sizeof(struct tcphdr));
1114 tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
1116 * now fill fields left out earlier
1118 ip->ip_ttl = ip_defttl;
1119 ip->ip_len = m->m_pkthdr.len;
1120 bzero (&sro, sizeof (sro));
1121 ip_rtaddr(ip->ip_dst, &sro);
1122 m->m_flags |= M_SKIP_FIREWALL;
1123 ip_output(m, NULL, &sro, 0, NULL, NULL);
1129 * sends a reject message, consuming the mbuf passed as an argument.
1132 send_reject(struct ip_fw_args *args, int code, int offset, int ip_len)
1135 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
1136 /* We need the IP header in host order for icmp_error(). */
1137 if (args->eh != NULL) {
1138 struct ip *ip = mtod(args->m, struct ip *);
1139 ip->ip_len = ntohs(ip->ip_len);
1140 ip->ip_off = ntohs(ip->ip_off);
1142 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
1143 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
1144 struct tcphdr *const tcp =
1145 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
1146 if ( (tcp->th_flags & TH_RST) == 0)
1147 send_pkt(&(args->f_id), ntohl(tcp->th_seq),
1149 tcp->th_flags | TH_RST);
1158 * Given an ip_fw *, lookup_next_rule will return a pointer
1159 * to the next rule, which can be either the jump
1160 * target (for skipto instructions) or the next one in the list (in
1161 * all other cases including a missing jump target).
1162 * The result is also written in the "next_rule" field of the rule.
1163 * Backward jumps are not allowed, so start looking from the next
1166 * This never returns NULL -- in case we do not have an exact match,
1167 * the next rule is returned. When the ruleset is changed,
1168 * pointers are flushed so we are always correct.
1171 static struct ip_fw *
1172 lookup_next_rule(struct ip_fw *me)
1174 struct ip_fw *rule = NULL;
1177 /* look for action, in case it is a skipto */
1178 cmd = ACTION_PTR(me);
1179 if (cmd->opcode == O_LOG)
1181 if ( cmd->opcode == O_SKIPTO )
1182 for (rule = me->next; rule ; rule = rule->next)
1183 if (rule->rulenum >= cmd->arg1)
1185 if (rule == NULL) /* failure or not a skipto */
1187 me->next_rule = rule;
1192 * The main check routine for the firewall.
1194 * All arguments are in args so we can modify them and return them
1195 * back to the caller.
1199 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
1200 * Starts with the IP header.
1201 * args->eh (in) Mac header if present, or NULL for layer3 packet.
1202 * args->oif Outgoing interface, or NULL if packet is incoming.
1203 * The incoming interface is in the mbuf. (in)
1204 * args->divert_rule (in/out)
1205 * Skip up to the first rule past this rule number;
1206 * upon return, non-zero port number for divert or tee.
1208 * args->rule Pointer to the last matching rule (in/out)
1209 * args->next_hop Socket we are forwarding to (out).
1210 * args->f_id Addresses grabbed from the packet (out)
1214 * IP_FW_PORT_DENY_FLAG the packet must be dropped.
1215 * 0 The packet is to be accepted and routed normally OR
1216 * the packet was denied/rejected and has been dropped;
1217 * in the latter case, *m is equal to NULL upon return.
1218 * port Divert the packet to port, with these caveats:
1220 * - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead
1221 * of diverting it (ie, 'ipfw tee').
1223 * - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower
1224 * 16 bits as a dummynet pipe number instead of diverting
1228 ipfw_chk(struct ip_fw_args *args)
1231 * Local variables hold state during the processing of a packet.
1233 * IMPORTANT NOTE: to speed up the processing of rules, there
1234 * are some assumption on the values of the variables, which
1235 * are documented here. Should you change them, please check
1236 * the implementation of the various instructions to make sure
1237 * that they still work.
1239 * args->eh The MAC header. It is non-null for a layer2
1240 * packet, it is NULL for a layer-3 packet.
1242 * m | args->m Pointer to the mbuf, as received from the caller.
1243 * It may change if ipfw_chk() does an m_pullup, or if it
1244 * consumes the packet because it calls send_reject().
1245 * XXX This has to change, so that ipfw_chk() never modifies
1246 * or consumes the buffer.
1247 * ip is simply an alias of the value of m, and it is kept
1248 * in sync with it (the packet is supposed to start with
1251 struct mbuf *m = args->m;
1252 struct ip *ip = mtod(m, struct ip *);
1255 * oif | args->oif If NULL, ipfw_chk has been called on the
1256 * inbound path (ether_input, bdg_forward, ip_input).
1257 * If non-NULL, ipfw_chk has been called on the outbound path
1258 * (ether_output, ip_output).
1260 struct ifnet *oif = args->oif;
1262 struct ip_fw *f = NULL; /* matching rule */
1266 * hlen The length of the IPv4 header.
1267 * hlen >0 means we have an IPv4 packet.
1269 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
1272 * offset The offset of a fragment. offset != 0 means that
1273 * we have a fragment at this offset of an IPv4 packet.
1274 * offset == 0 means that (if this is an IPv4 packet)
1275 * this is the first or only fragment.
1280 * Local copies of addresses. They are only valid if we have
1283 * proto The protocol. Set to 0 for non-ip packets,
1284 * or to the protocol read from the packet otherwise.
1285 * proto != 0 means that we have an IPv4 packet.
1287 * src_port, dst_port port numbers, in HOST format. Only
1288 * valid for TCP and UDP packets.
1290 * src_ip, dst_ip ip addresses, in NETWORK format.
1291 * Only valid for IPv4 packets.
1294 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */
1295 struct in_addr src_ip, dst_ip; /* NOTE: network format */
1297 int dyn_dir = MATCH_UNKNOWN;
1298 ipfw_dyn_rule *q = NULL;
1300 if (m->m_flags & M_SKIP_FIREWALL)
1301 return 0; /* accept */
1303 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
1304 * MATCH_NONE when checked and not matched (q = NULL),
1305 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
1308 if (args->eh == NULL || /* layer 3 packet */
1309 ( m->m_pkthdr.len >= sizeof(struct ip) &&
1310 ntohs(args->eh->ether_type) == ETHERTYPE_IP))
1311 hlen = ip->ip_hl << 2;
1314 * Collect parameters into local variables for faster matching.
1316 if (hlen == 0) { /* do not grab addresses for non-ip pkts */
1317 proto = args->f_id.proto = 0; /* mark f_id invalid */
1318 goto after_ip_checks;
1321 proto = args->f_id.proto = ip->ip_p;
1322 src_ip = ip->ip_src;
1323 dst_ip = ip->ip_dst;
1324 if (args->eh != NULL) { /* layer 2 packets are as on the wire */
1325 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1326 ip_len = ntohs(ip->ip_len);
1328 offset = ip->ip_off & IP_OFFMASK;
1329 ip_len = ip->ip_len;
1332 #define PULLUP_TO(len) \
1334 if ((m)->m_len < (len)) { \
1335 args->m = m = m_pullup(m, (len)); \
1337 goto pullup_failed; \
1338 ip = mtod(m, struct ip *); \
1348 PULLUP_TO(hlen + sizeof(struct tcphdr));
1349 tcp = L3HDR(struct tcphdr, ip);
1350 dst_port = tcp->th_dport;
1351 src_port = tcp->th_sport;
1352 args->f_id.flags = tcp->th_flags;
1360 PULLUP_TO(hlen + sizeof(struct udphdr));
1361 udp = L3HDR(struct udphdr, ip);
1362 dst_port = udp->uh_dport;
1363 src_port = udp->uh_sport;
1368 PULLUP_TO(hlen + 4); /* type, code and checksum. */
1369 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type;
1378 args->f_id.src_ip = ntohl(src_ip.s_addr);
1379 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1380 args->f_id.src_port = src_port = ntohs(src_port);
1381 args->f_id.dst_port = dst_port = ntohs(dst_port);
1386 * Packet has already been tagged. Look for the next rule
1387 * to restart processing.
1389 * If fw_one_pass != 0 then just accept it.
1390 * XXX should not happen here, but optimized out in
1396 f = args->rule->next_rule;
1398 f = lookup_next_rule(args->rule);
1401 * Find the starting rule. It can be either the first
1402 * one, or the one after divert_rule if asked so.
1404 int skipto = args->divert_rule;
1407 if (args->eh == NULL && skipto != 0) {
1408 if (skipto >= IPFW_DEFAULT_RULE)
1409 return(IP_FW_PORT_DENY_FLAG); /* invalid */
1410 while (f && f->rulenum <= skipto)
1412 if (f == NULL) /* drop packet */
1413 return(IP_FW_PORT_DENY_FLAG);
1416 args->divert_rule = 0; /* reset to avoid confusion later */
1419 * Now scan the rules, and parse microinstructions for each rule.
1421 for (; f; f = f->next) {
1424 int skip_or; /* skip rest of OR block */
1427 if (set_disable & (1 << f->set) )
1431 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1432 l -= cmdlen, cmd += cmdlen) {
1436 * check_body is a jump target used when we find a
1437 * CHECK_STATE, and need to jump to the body of
1442 cmdlen = F_LEN(cmd);
1444 * An OR block (insn_1 || .. || insn_n) has the
1445 * F_OR bit set in all but the last instruction.
1446 * The first match will set "skip_or", and cause
1447 * the following instructions to be skipped until
1448 * past the one with the F_OR bit clear.
1450 if (skip_or) { /* skip this instruction */
1451 if ((cmd->len & F_OR) == 0)
1452 skip_or = 0; /* next one is good */
1455 match = 0; /* set to 1 if we succeed */
1457 switch (cmd->opcode) {
1459 * The first set of opcodes compares the packet's
1460 * fields with some pattern, setting 'match' if a
1461 * match is found. At the end of the loop there is
1462 * logic to deal with F_NOT and F_OR flags associated
1470 printf("ipfw: opcode %d unimplemented\n",
1477 * We only check offset == 0 && proto != 0,
1478 * as this ensures that we have an IPv4
1479 * packet with the ports info.
1484 struct inpcbinfo *pi;
1488 if (proto == IPPROTO_TCP) {
1490 pi = &tcbinfo[mycpu->gd_cpuid];
1491 } else if (proto == IPPROTO_UDP) {
1498 in_pcblookup_hash(pi,
1499 dst_ip, htons(dst_port),
1500 src_ip, htons(src_port),
1502 in_pcblookup_hash(pi,
1503 src_ip, htons(src_port),
1504 dst_ip, htons(dst_port),
1507 if (pcb == NULL || pcb->inp_socket == NULL)
1509 #if defined(__DragonFly__) || (defined(__FreeBSD__) && __FreeBSD_version < 500034)
1510 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b))
1512 if (cmd->opcode == O_UID) {
1514 !socheckuid(pcb->inp_socket,
1515 (uid_t)((ipfw_insn_u32 *)cmd)->d[0]);
1517 match = groupmember(
1518 (uid_t)((ipfw_insn_u32 *)cmd)->d[0],
1519 pcb->inp_socket->so_cred);
1525 match = iface_match(m->m_pkthdr.rcvif,
1526 (ipfw_insn_if *)cmd);
1530 match = iface_match(oif, (ipfw_insn_if *)cmd);
1534 match = iface_match(oif ? oif :
1535 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1539 if (args->eh != NULL) { /* have MAC header */
1540 u_int32_t *want = (u_int32_t *)
1541 ((ipfw_insn_mac *)cmd)->addr;
1542 u_int32_t *mask = (u_int32_t *)
1543 ((ipfw_insn_mac *)cmd)->mask;
1544 u_int32_t *hdr = (u_int32_t *)args->eh;
1547 ( want[0] == (hdr[0] & mask[0]) &&
1548 want[1] == (hdr[1] & mask[1]) &&
1549 want[2] == (hdr[2] & mask[2]) );
1554 if (args->eh != NULL) {
1556 ntohs(args->eh->ether_type);
1558 ((ipfw_insn_u16 *)cmd)->ports;
1561 for (i = cmdlen - 1; !match && i>0;
1563 match = (t>=p[0] && t<=p[1]);
1568 match = (hlen > 0 && offset != 0);
1571 case O_IN: /* "out" is "not in" */
1572 match = (oif == NULL);
1576 match = (args->eh != NULL);
1581 * We do not allow an arg of 0 so the
1582 * check of "proto" only suffices.
1584 match = (proto == cmd->arg1);
1588 match = (hlen > 0 &&
1589 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1594 match = (hlen > 0 &&
1595 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1597 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1604 INADDR_TO_IFP(src_ip, tif);
1605 match = (tif != NULL);
1612 u_int32_t *d = (u_int32_t *)(cmd+1);
1614 cmd->opcode == O_IP_DST_SET ?
1620 addr -= d[0]; /* subtract base */
1621 match = (addr < cmd->arg1) &&
1622 ( d[ 1 + (addr>>5)] &
1623 (1<<(addr & 0x1f)) );
1628 match = (hlen > 0 &&
1629 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1634 match = (hlen > 0) &&
1635 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1637 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1644 INADDR_TO_IFP(dst_ip, tif);
1645 match = (tif != NULL);
1652 * offset == 0 && proto != 0 is enough
1653 * to guarantee that we have an IPv4
1654 * packet with port info.
1656 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1659 (cmd->opcode == O_IP_SRCPORT) ?
1660 src_port : dst_port ;
1662 ((ipfw_insn_u16 *)cmd)->ports;
1665 for (i = cmdlen - 1; !match && i>0;
1667 match = (x>=p[0] && x<=p[1]);
1672 match = (offset == 0 && proto==IPPROTO_ICMP &&
1673 icmptype_match(ip, (ipfw_insn_u32 *)cmd) );
1677 match = (hlen > 0 && ipopts_match(ip, cmd) );
1681 match = (hlen > 0 && cmd->arg1 == ip->ip_v);
1685 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl);
1689 match = (hlen > 0 &&
1690 cmd->arg1 == ntohs(ip->ip_id));
1694 match = (hlen > 0 && cmd->arg1 == ip_len);
1697 case O_IPPRECEDENCE:
1698 match = (hlen > 0 &&
1699 (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1703 match = (hlen > 0 &&
1704 flags_match(cmd, ip->ip_tos));
1708 match = (proto == IPPROTO_TCP && offset == 0 &&
1710 L3HDR(struct tcphdr,ip)->th_flags));
1714 match = (proto == IPPROTO_TCP && offset == 0 &&
1715 tcpopts_match(ip, cmd));
1719 match = (proto == IPPROTO_TCP && offset == 0 &&
1720 ((ipfw_insn_u32 *)cmd)->d[0] ==
1721 L3HDR(struct tcphdr,ip)->th_seq);
1725 match = (proto == IPPROTO_TCP && offset == 0 &&
1726 ((ipfw_insn_u32 *)cmd)->d[0] ==
1727 L3HDR(struct tcphdr,ip)->th_ack);
1731 match = (proto == IPPROTO_TCP && offset == 0 &&
1733 L3HDR(struct tcphdr,ip)->th_win);
1737 /* reject packets which have SYN only */
1738 /* XXX should i also check for TH_ACK ? */
1739 match = (proto == IPPROTO_TCP && offset == 0 &&
1740 (L3HDR(struct tcphdr,ip)->th_flags &
1741 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1746 ipfw_log(f, hlen, args->eh, m, oif);
1751 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1755 * The second set of opcodes represents 'actions',
1756 * i.e. the terminal part of a rule once the packet
1757 * matches all previous patterns.
1758 * Typically there is only one action for each rule,
1759 * and the opcode is stored at the end of the rule
1760 * (but there are exceptions -- see below).
1762 * In general, here we set retval and terminate the
1763 * outer loop (would be a 'break 3' in some language,
1764 * but we need to do a 'goto done').
1767 * O_COUNT and O_SKIPTO actions:
1768 * instead of terminating, we jump to the next rule
1769 * ('goto next_rule', equivalent to a 'break 2'),
1770 * or to the SKIPTO target ('goto again' after
1771 * having set f, cmd and l), respectively.
1773 * O_LIMIT and O_KEEP_STATE: these opcodes are
1774 * not real 'actions', and are stored right
1775 * before the 'action' part of the rule.
1776 * These opcodes try to install an entry in the
1777 * state tables; if successful, we continue with
1778 * the next opcode (match=1; break;), otherwise
1779 * the packet * must be dropped
1780 * ('goto done' after setting retval);
1782 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1783 * cause a lookup of the state table, and a jump
1784 * to the 'action' part of the parent rule
1785 * ('goto check_body') if an entry is found, or
1786 * (CHECK_STATE only) a jump to the next rule if
1787 * the entry is not found ('goto next_rule').
1788 * The result of the lookup is cached to make
1789 * further instances of these opcodes are
1794 if (install_state(f,
1795 (ipfw_insn_limit *)cmd, args)) {
1796 retval = IP_FW_PORT_DENY_FLAG;
1797 goto done; /* error/limit violation */
1805 * dynamic rules are checked at the first
1806 * keep-state or check-state occurrence,
1807 * with the result being stored in dyn_dir.
1808 * The compiler introduces a PROBE_STATE
1809 * instruction for us when we have a
1810 * KEEP_STATE (because PROBE_STATE needs
1813 if (dyn_dir == MATCH_UNKNOWN &&
1814 (q = lookup_dyn_rule(&args->f_id,
1815 &dyn_dir, proto == IPPROTO_TCP ?
1816 L3HDR(struct tcphdr, ip) : NULL))
1819 * Found dynamic entry, update stats
1820 * and jump to the 'action' part of
1826 cmd = ACTION_PTR(f);
1827 l = f->cmd_len - f->act_ofs;
1831 * Dynamic entry not found. If CHECK_STATE,
1832 * skip to next rule, if PROBE_STATE just
1833 * ignore and continue with next opcode.
1835 if (cmd->opcode == O_CHECK_STATE)
1841 retval = 0; /* accept */
1846 args->rule = f; /* report matching rule */
1847 retval = cmd->arg1 | IP_FW_PORT_DYNT_FLAG;
1852 if (args->eh) /* not on layer 2 */
1854 args->divert_rule = f->rulenum;
1855 retval = (cmd->opcode == O_DIVERT) ?
1857 cmd->arg1 | IP_FW_PORT_TEE_FLAG;
1862 f->pcnt++; /* update stats */
1864 f->timestamp = time_second;
1865 if (cmd->opcode == O_COUNT)
1868 if (f->next_rule == NULL)
1869 lookup_next_rule(f);
1875 * Drop the packet and send a reject notice
1876 * if the packet is not ICMP (or is an ICMP
1877 * query), and it is not multicast/broadcast.
1880 (proto != IPPROTO_ICMP ||
1881 is_icmp_query(ip)) &&
1882 !(m->m_flags & (M_BCAST|M_MCAST)) &&
1883 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
1884 send_reject(args, cmd->arg1,
1890 retval = IP_FW_PORT_DENY_FLAG;
1894 if (args->eh) /* not valid on layer2 pkts */
1896 if (!q || dyn_dir == MATCH_FORWARD)
1898 &((ipfw_insn_sa *)cmd)->sa;
1903 panic("-- unknown opcode %d\n", cmd->opcode);
1904 } /* end of switch() on opcodes */
1906 if (cmd->len & F_NOT)
1910 if (cmd->len & F_OR)
1913 if (!(cmd->len & F_OR)) /* not an OR block, */
1914 break; /* try next rule */
1917 } /* end of inner for, scan opcodes */
1919 next_rule:; /* try next rule */
1921 } /* end of outer for, scan rules */
1922 printf("+++ ipfw: ouch!, skip past end of rules, denying packet\n");
1923 return(IP_FW_PORT_DENY_FLAG);
1926 /* Update statistics */
1929 f->timestamp = time_second;
1934 printf("pullup failed\n");
1935 return(IP_FW_PORT_DENY_FLAG);
1939 * When a rule is added/deleted, clear the next_rule pointers in all rules.
1940 * These will be reconstructed on the fly as packets are matched.
1941 * Must be called at splimp().
1944 flush_rule_ptrs(void)
1948 for (rule = layer3_chain; rule; rule = rule->next)
1949 rule->next_rule = NULL;
1953 * When pipes/queues are deleted, clear the "pipe_ptr" pointer to a given
1954 * pipe/queue, or to all of them (match == NULL).
1955 * Must be called at splimp().
1958 flush_pipe_ptrs(struct dn_flow_set *match)
1962 for (rule = layer3_chain; rule; rule = rule->next) {
1963 ipfw_insn_pipe *cmd = (ipfw_insn_pipe *)ACTION_PTR(rule);
1965 if (cmd->o.opcode != O_PIPE && cmd->o.opcode != O_QUEUE)
1967 if (match == NULL || cmd->pipe_ptr == match)
1968 cmd->pipe_ptr = NULL;
1973 * Add a new rule to the list. Copy the rule into a malloc'ed area, then
1974 * possibly create a rule number and add the rule to the list.
1975 * Update the rule_number in the input struct so the caller knows it as well.
1978 add_rule(struct ip_fw **head, struct ip_fw *input_rule)
1980 struct ip_fw *rule, *f, *prev;
1982 int l = RULESIZE(input_rule);
1984 if (*head == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE)
1987 rule = malloc(l, M_IPFW, M_WAITOK | M_ZERO);
1991 bcopy(input_rule, rule, l);
1994 rule->next_rule = NULL;
1998 rule->timestamp = 0;
2002 if (*head == NULL) { /* default rule */
2008 * If rulenum is 0, find highest numbered rule before the
2009 * default rule, and add autoinc_step
2011 if (autoinc_step < 1)
2013 else if (autoinc_step > 1000)
2014 autoinc_step = 1000;
2015 if (rule->rulenum == 0) {
2017 * locate the highest numbered rule before default
2019 for (f = *head; f; f = f->next) {
2020 if (f->rulenum == IPFW_DEFAULT_RULE)
2022 rule->rulenum = f->rulenum;
2024 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step)
2025 rule->rulenum += autoinc_step;
2026 input_rule->rulenum = rule->rulenum;
2030 * Now insert the new rule in the right place in the sorted list.
2032 for (prev = NULL, f = *head; f; prev = f, f = f->next) {
2033 if (f->rulenum > rule->rulenum) { /* found the location */
2037 } else { /* head insert */
2049 DEB(printf("++ installed rule %d, static count now %d\n",
2050 rule->rulenum, static_count);)
2055 * Free storage associated with a static rule (including derived
2057 * The caller is in charge of clearing rule pointers to avoid
2058 * dangling pointers.
2059 * @return a pointer to the next entry.
2060 * Arguments are not checked, so they better be correct.
2061 * Must be called at splimp().
2063 static struct ip_fw *
2064 delete_rule(struct ip_fw **head, struct ip_fw *prev, struct ip_fw *rule)
2067 int l = RULESIZE(rule);
2070 remove_dyn_rule(rule, NULL /* force removal */);
2078 if (DUMMYNET_LOADED)
2079 ip_dn_ruledel_ptr(rule);
2085 * Deletes all rules from a chain (including the default rule
2086 * if the second argument is set).
2087 * Must be called at splimp().
2090 free_chain(struct ip_fw **chain, int kill_default)
2094 flush_rule_ptrs(); /* more efficient to do outside the loop */
2096 while ( (rule = *chain) != NULL &&
2097 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE) )
2098 delete_rule(chain, NULL, rule);
2102 * Remove all rules with given number, and also do set manipulation.
2104 * The argument is an u_int32_t. The low 16 bit are the rule or set number,
2105 * the next 8 bits are the new set, the top 8 bits are the command:
2107 * 0 delete rules with given number
2108 * 1 delete rules with given set number
2109 * 2 move rules with given number to new set
2110 * 3 move rules with given set number to new set
2111 * 4 swap sets with given numbers
2114 del_entry(struct ip_fw **chain, u_int32_t arg)
2116 struct ip_fw *prev, *rule;
2119 u_int8_t cmd, new_set;
2121 rulenum = arg & 0xffff;
2122 cmd = (arg >> 24) & 0xff;
2123 new_set = (arg >> 16) & 0xff;
2129 if (cmd == 0 || cmd == 2) {
2130 if (rulenum == IPFW_DEFAULT_RULE)
2138 case 0: /* delete rules with given number */
2140 * locate first rule to delete
2142 for (prev = NULL, rule = *chain;
2143 rule && rule->rulenum < rulenum;
2144 prev = rule, rule = rule->next)
2146 if (rule->rulenum != rulenum)
2149 s = splimp(); /* no access to rules while removing */
2151 * flush pointers outside the loop, then delete all matching
2152 * rules. prev remains the same throughout the cycle.
2155 while (rule && rule->rulenum == rulenum)
2156 rule = delete_rule(chain, prev, rule);
2160 case 1: /* delete all rules with given set number */
2163 for (prev = NULL, rule = *chain; rule ; )
2164 if (rule->set == rulenum)
2165 rule = delete_rule(chain, prev, rule);
2173 case 2: /* move rules with given number to new set */
2175 for (rule = *chain; rule ; rule = rule->next)
2176 if (rule->rulenum == rulenum)
2177 rule->set = new_set;
2181 case 3: /* move rules with given set number to new set */
2183 for (rule = *chain; rule ; rule = rule->next)
2184 if (rule->set == rulenum)
2185 rule->set = new_set;
2189 case 4: /* swap two sets */
2191 for (rule = *chain; rule ; rule = rule->next)
2192 if (rule->set == rulenum)
2193 rule->set = new_set;
2194 else if (rule->set == new_set)
2195 rule->set = rulenum;
2203 * Clear counters for a specific rule.
2206 clear_counters(struct ip_fw *rule, int log_only)
2208 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
2210 if (log_only == 0) {
2211 rule->bcnt = rule->pcnt = 0;
2212 rule->timestamp = 0;
2214 if (l->o.opcode == O_LOG)
2215 l->log_left = l->max_log;
2219 * Reset some or all counters on firewall rules.
2220 * @arg frwl is null to clear all entries, or contains a specific
2222 * @arg log_only is 1 if we only want to reset logs, zero otherwise.
2225 zero_entry(int rulenum, int log_only)
2234 for (rule = layer3_chain; rule; rule = rule->next)
2235 clear_counters(rule, log_only);
2237 msg = log_only ? "ipfw: All logging counts reset.\n" :
2238 "ipfw: Accounting cleared.\n";
2242 * We can have multiple rules with the same number, so we
2243 * need to clear them all.
2245 for (rule = layer3_chain; rule; rule = rule->next)
2246 if (rule->rulenum == rulenum) {
2248 while (rule && rule->rulenum == rulenum) {
2249 clear_counters(rule, log_only);
2256 if (!cleared) /* we did not find any matching rules */
2258 msg = log_only ? "ipfw: Entry %d logging count reset.\n" :
2259 "ipfw: Entry %d cleared.\n";
2262 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
2267 * Check validity of the structure before insert.
2268 * Fortunately rules are simple, so this mostly need to check rule sizes.
2271 check_ipfw_struct(struct ip_fw *rule, int size)
2277 if (size < sizeof(*rule)) {
2278 printf("ipfw: rule too short\n");
2281 /* first, check for valid size */
2284 printf("ipfw: size mismatch (have %d want %d)\n", size, l);
2288 * Now go for the individual checks. Very simple ones, basically only
2289 * instruction sizes.
2291 for (l = rule->cmd_len, cmd = rule->cmd ;
2292 l > 0 ; l -= cmdlen, cmd += cmdlen) {
2293 cmdlen = F_LEN(cmd);
2295 printf("ipfw: opcode %d size truncated\n",
2299 DEB(printf("ipfw: opcode %d\n", cmd->opcode);)
2300 switch (cmd->opcode) {
2314 case O_IPPRECEDENCE:
2321 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2333 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
2338 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
2343 if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
2346 ((ipfw_insn_log *)cmd)->log_left =
2347 ((ipfw_insn_log *)cmd)->max_log;
2353 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip))
2355 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) {
2356 printf("ipfw: opcode %d, useless rule\n",
2364 if (cmd->arg1 == 0 || cmd->arg1 > 256) {
2365 printf("ipfw: invalid set size %d\n",
2369 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
2375 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
2381 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
2382 if (cmdlen < 2 || cmdlen > 31)
2389 if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
2395 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
2400 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
2404 case O_FORWARD_MAC: /* XXX not implemented yet */
2413 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2417 printf("ipfw: opcode %d, multiple actions"
2424 printf("ipfw: opcode %d, action must be"
2431 printf("ipfw: opcode %d, unknown opcode\n",
2436 if (have_action == 0) {
2437 printf("ipfw: missing action\n");
2443 printf("ipfw: opcode %d size %d wrong\n",
2444 cmd->opcode, cmdlen);
2450 * {set|get}sockopt parser.
2453 ipfw_ctl(struct sockopt *sopt)
2455 int error, s, rulenum;
2457 struct ip_fw *bp , *buf, *rule;
2459 static u_int32_t rule_buf[255]; /* we copy the data here */
2462 * Disallow modifications in really-really secure mode, but still allow
2463 * the logging counters to be reset.
2465 if (sopt->sopt_name == IP_FW_ADD ||
2466 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) {
2467 #if defined(__FreeBSD__) && __FreeBSD_version >= 500034
2468 error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
2471 #else /* FreeBSD 4.x */
2472 if (securelevel >= 3)
2479 switch (sopt->sopt_name) {
2482 * pass up a copy of the current rules. Static rules
2483 * come first (the last of which has number IPFW_DEFAULT_RULE),
2484 * followed by a possibly empty list of dynamic rule.
2485 * The last dynamic rule has NULL in the "next" field.
2488 size = static_len; /* size of static rules */
2489 if (ipfw_dyn_v) /* add size of dyn.rules */
2490 size += (dyn_count * sizeof(ipfw_dyn_rule));
2493 * XXX todo: if the user passes a short length just to know
2494 * how much room is needed, do not bother filling up the
2495 * buffer, just jump to the sooptcopyout.
2497 buf = malloc(size, M_TEMP, M_WAITOK);
2500 for (rule = layer3_chain; rule ; rule = rule->next) {
2501 int i = RULESIZE(rule);
2504 * abuse 'next_rule' to store the set_disable word
2506 (u_int32_t)(((struct ip_fw *)bp)->next_rule) =
2508 bp = (struct ip_fw *)((char *)bp + i);
2512 ipfw_dyn_rule *p, *dst, *last = NULL;
2514 dst = (ipfw_dyn_rule *)bp;
2515 for (i = 0 ; i < curr_dyn_buckets ; i++ )
2516 for ( p = ipfw_dyn_v[i] ; p != NULL ;
2517 p = p->next, dst++ ) {
2518 bcopy(p, dst, sizeof *p);
2519 (int)dst->rule = p->rule->rulenum ;
2521 * store a non-null value in "next".
2522 * The userland code will interpret a
2523 * NULL here as a marker
2524 * for the last dynamic rule.
2529 TIME_LEQ(dst->expire, time_second) ?
2530 0 : dst->expire - time_second ;
2532 if (last != NULL) /* mark last dynamic rule */
2537 error = sooptcopyout(sopt, buf, size);
2543 * Normally we cannot release the lock on each iteration.
2544 * We could do it here only because we start from the head all
2545 * the times so there is no risk of missing some entries.
2546 * On the other hand, the risk is that we end up with
2547 * a very inconsistent ruleset, so better keep the lock
2548 * around the whole cycle.
2550 * XXX this code can be improved by resetting the head of
2551 * the list to point to the default rule, and then freeing
2552 * the old list without the need for a lock.
2556 free_chain(&layer3_chain, 0 /* keep default rule */);
2561 rule = (struct ip_fw *)rule_buf; /* XXX do a malloc */
2562 error = sooptcopyin(sopt, rule, sizeof(rule_buf),
2563 sizeof(struct ip_fw) );
2564 size = sopt->sopt_valsize;
2565 if (error || (error = check_ipfw_struct(rule, size)))
2568 error = add_rule(&layer3_chain, rule);
2569 size = RULESIZE(rule);
2570 if (!error && sopt->sopt_dir == SOPT_GET)
2571 error = sooptcopyout(sopt, rule, size);
2576 * IP_FW_DEL is used for deleting single rules or sets,
2577 * and (ab)used to atomically manipulate sets. Argument size
2578 * is used to distinguish between the two:
2580 * delete single rule or set of rules,
2581 * or reassign rules (or sets) to a different set.
2582 * 2*sizeof(u_int32_t)
2583 * atomic disable/enable sets.
2584 * first u_int32_t contains sets to be disabled,
2585 * second u_int32_t contains sets to be enabled.
2587 error = sooptcopyin(sopt, rule_buf,
2588 2*sizeof(u_int32_t), sizeof(u_int32_t));
2591 size = sopt->sopt_valsize;
2592 if (size == sizeof(u_int32_t)) /* delete or reassign */
2593 error = del_entry(&layer3_chain, rule_buf[0]);
2594 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */
2596 (set_disable | rule_buf[0]) & ~rule_buf[1] &
2597 ~(1<<31); /* set 31 always enabled */
2603 case IP_FW_RESETLOG: /* argument is an int, the rule number */
2606 if (sopt->sopt_val != 0) {
2607 error = sooptcopyin(sopt, &rulenum,
2608 sizeof(int), sizeof(int));
2612 error = zero_entry(rulenum, sopt->sopt_name == IP_FW_RESETLOG);
2616 printf("ipfw_ctl invalid option %d\n", sopt->sopt_name);
2624 * dummynet needs a reference to the default rule, because rules can be
2625 * deleted while packets hold a reference to them. When this happens,
2626 * dummynet changes the reference to the default rule (it could well be a
2627 * NULL pointer, but this way we do not need to check for the special
2628 * case, plus here he have info on the default behaviour).
2630 struct ip_fw *ip_fw_default_rule;
2633 * This procedure is only used to handle keepalives. It is invoked
2634 * every dyn_keepalive_period
2637 ipfw_tick(void * __unused unused)
2643 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0)
2647 for (i = 0 ; i < curr_dyn_buckets ; i++) {
2648 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) {
2649 if (q->dyn_type == O_LIMIT_PARENT)
2651 if (q->id.proto != IPPROTO_TCP)
2653 if ( (q->state & BOTH_SYN) != BOTH_SYN)
2655 if (TIME_LEQ( time_second+dyn_keepalive_interval,
2657 continue; /* too early */
2658 if (TIME_LEQ(q->expire, time_second))
2659 continue; /* too late, rule expired */
2661 send_pkt(&(q->id), q->ack_rev - 1, q->ack_fwd, TH_SYN);
2662 send_pkt(&(q->id), q->ack_fwd - 1, q->ack_rev, 0);
2667 ipfw_timeout_h = timeout(ipfw_tick, NULL, dyn_keepalive_period*hz);
2673 struct ip_fw default_rule;
2675 ip_fw_chk_ptr = ipfw_chk;
2676 ip_fw_ctl_ptr = ipfw_ctl;
2677 layer3_chain = NULL;
2679 bzero(&default_rule, sizeof default_rule);
2681 default_rule.act_ofs = 0;
2682 default_rule.rulenum = IPFW_DEFAULT_RULE;
2683 default_rule.cmd_len = 1;
2684 default_rule.set = 31;
2686 default_rule.cmd[0].len = 1;
2687 default_rule.cmd[0].opcode =
2688 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
2693 add_rule(&layer3_chain, &default_rule);
2695 ip_fw_default_rule = layer3_chain;
2696 printf("ipfw2 initialized, divert %s, "
2697 "rule-based forwarding enabled, default to %s, logging ",
2703 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny");
2705 #ifdef IPFIREWALL_VERBOSE
2708 #ifdef IPFIREWALL_VERBOSE_LIMIT
2709 verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2711 if (fw_verbose == 0)
2712 printf("disabled\n");
2713 else if (verbose_limit == 0)
2714 printf("unlimited\n");
2716 printf("limited to %d packets/entry by default\n",
2718 bzero(&ipfw_timeout_h, sizeof(struct callout_handle));
2719 ipfw_timeout_h = timeout(ipfw_tick, NULL, hz);
2723 ipfw_modevent(module_t mod, int type, void *unused)
2733 printf("IP firewall already loaded\n");
2742 #if !defined(KLD_MODULE)
2743 printf("ipfw statically compiled, cannot unload\n");
2747 untimeout(ipfw_tick, NULL, ipfw_timeout_h);
2748 ip_fw_chk_ptr = NULL;
2749 ip_fw_ctl_ptr = NULL;
2750 free_chain(&layer3_chain, 1 /* kill default rule */);
2752 printf("IP firewall unloaded\n");
2761 static moduledata_t ipfwmod = {
2766 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2767 MODULE_VERSION(ipfw, 1);