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 1.6 2004/02/13 17:45:51 joerg 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>
59 #include <net/route.h>
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/in_var.h>
63 #include <netinet/in_pcb.h>
64 #include <netinet/ip.h>
65 #include <netinet/ip_var.h>
66 #include <netinet/ip_icmp.h>
68 #include <net/dummynet/ip_dummynet.h>
69 #include <netinet/tcp.h>
70 #include <netinet/tcp_timer.h>
71 #include <netinet/tcp_var.h>
72 #include <netinet/tcpip.h>
73 #include <netinet/udp.h>
74 #include <netinet/udp_var.h>
76 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
78 #include <machine/in_cksum.h> /* XXX for in_cksum */
81 * XXX This one should go in sys/mbuf.h. It is used to avoid that
82 * a firewall-generated packet loops forever through the firewall.
84 #ifndef M_SKIP_FIREWALL
85 #define M_SKIP_FIREWALL 0x4000
89 * set_disable contains one bit per set value (0..31).
90 * If the bit is set, all rules with the corresponding set
91 * are disabled. Set 31 is reserved for the default rule
92 * and CANNOT be disabled.
94 static u_int32_t set_disable;
96 static int fw_verbose;
97 static int verbose_limit;
99 static struct callout_handle ipfw_timeout_h;
100 #define IPFW_DEFAULT_RULE 65535
103 * list of rules for layer 3
105 static struct ip_fw *layer3_chain;
107 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
109 static int fw_debug = 1;
110 static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
113 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
114 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_RW,
115 &fw_enable, 0, "Enable ipfw");
116 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW,
117 &autoinc_step, 0, "Rule number autincrement step");
118 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
120 "Only do a single pass through ipfw when using dummynet(4)");
121 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
122 &fw_debug, 0, "Enable printing of debug ip_fw statements");
123 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
124 &fw_verbose, 0, "Log matches to ipfw rules");
125 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
126 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
129 * Description of dynamic rules.
131 * Dynamic rules are stored in lists accessed through a hash table
132 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
133 * be modified through the sysctl variable dyn_buckets which is
134 * updated when the table becomes empty.
136 * XXX currently there is only one list, ipfw_dyn.
138 * When a packet is received, its address fields are first masked
139 * with the mask defined for the rule, then hashed, then matched
140 * against the entries in the corresponding list.
141 * Dynamic rules can be used for different purposes:
143 * + enforcing limits on the number of sessions;
144 * + in-kernel NAT (not implemented yet)
146 * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
147 * measured in seconds and depending on the flags.
149 * The total number of dynamic rules is stored in dyn_count.
150 * The max number of dynamic rules is dyn_max. When we reach
151 * the maximum number of rules we do not create anymore. This is
152 * done to avoid consuming too much memory, but also too much
153 * time when searching on each packet (ideally, we should try instead
154 * to put a limit on the length of the list on each bucket...).
156 * Each dynamic rule holds a pointer to the parent ipfw rule so
157 * we know what action to perform. Dynamic rules are removed when
158 * the parent rule is deleted. XXX we should make them survive.
160 * There are some limitations with dynamic rules -- we do not
161 * obey the 'randomized match', and we do not do multiple
162 * passes through the firewall. XXX check the latter!!!
164 static ipfw_dyn_rule **ipfw_dyn_v = NULL;
165 static u_int32_t dyn_buckets = 256; /* must be power of 2 */
166 static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */
169 * Timeouts for various events in handing dynamic rules.
171 static u_int32_t dyn_ack_lifetime = 300;
172 static u_int32_t dyn_syn_lifetime = 20;
173 static u_int32_t dyn_fin_lifetime = 1;
174 static u_int32_t dyn_rst_lifetime = 1;
175 static u_int32_t dyn_udp_lifetime = 10;
176 static u_int32_t dyn_short_lifetime = 5;
179 * Keepalives are sent if dyn_keepalive is set. They are sent every
180 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
181 * seconds of lifetime of a rule.
182 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
183 * than dyn_keepalive_period.
186 static u_int32_t dyn_keepalive_interval = 20;
187 static u_int32_t dyn_keepalive_period = 5;
188 static u_int32_t dyn_keepalive = 1; /* do send keepalives */
190 static u_int32_t static_count; /* # of static rules */
191 static u_int32_t static_len; /* size in bytes of static rules */
192 static u_int32_t dyn_count; /* # of dynamic rules */
193 static u_int32_t dyn_max = 4096; /* max # of dynamic rules */
195 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
196 &dyn_buckets, 0, "Number of dyn. buckets");
197 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
198 &curr_dyn_buckets, 0, "Current Number of dyn. buckets");
199 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
200 &dyn_count, 0, "Number of dyn. rules");
201 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
202 &dyn_max, 0, "Max number of dyn. rules");
203 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
204 &static_count, 0, "Number of static rules");
205 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
206 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
207 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
208 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
209 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
210 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
211 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
212 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
213 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
214 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
215 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
216 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
217 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
218 &dyn_keepalive, 0, "Enable keepalives for dyn. rules");
220 #endif /* SYSCTL_NODE */
223 static ip_fw_chk_t ipfw_chk;
225 ip_dn_ruledel_t *ip_dn_ruledel_ptr = NULL; /* hook into dummynet */
228 * This macro maps an ip pointer into a layer3 header pointer of type T
230 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
233 icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd)
235 int type = L3HDR(struct icmp,ip)->icmp_type;
237 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
240 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
241 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
244 is_icmp_query(struct ip *ip)
246 int type = L3HDR(struct icmp, ip)->icmp_type;
247 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
252 * The following checks use two arrays of 8 or 16 bits to store the
253 * bits that we want set or clear, respectively. They are in the
254 * low and high half of cmd->arg1 or cmd->d[0].
256 * We scan options and store the bits we find set. We succeed if
258 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
260 * The code is sometimes optimized not to store additional variables.
264 flags_match(ipfw_insn *cmd, u_int8_t bits)
269 if ( ((cmd->arg1 & 0xff) & bits) != 0)
270 return 0; /* some bits we want set were clear */
271 want_clear = (cmd->arg1 >> 8) & 0xff;
272 if ( (want_clear & bits) != want_clear)
273 return 0; /* some bits we want clear were set */
278 ipopts_match(struct ip *ip, ipfw_insn *cmd)
280 int optlen, bits = 0;
281 u_char *cp = (u_char *)(ip + 1);
282 int x = (ip->ip_hl << 2) - sizeof (struct ip);
284 for (; x > 0; x -= optlen, cp += optlen) {
285 int opt = cp[IPOPT_OPTVAL];
287 if (opt == IPOPT_EOL)
289 if (opt == IPOPT_NOP)
292 optlen = cp[IPOPT_OLEN];
293 if (optlen <= 0 || optlen > x)
294 return 0; /* invalid or truncated */
302 bits |= IP_FW_IPOPT_LSRR;
306 bits |= IP_FW_IPOPT_SSRR;
310 bits |= IP_FW_IPOPT_RR;
314 bits |= IP_FW_IPOPT_TS;
318 return (flags_match(cmd, bits));
322 tcpopts_match(struct ip *ip, ipfw_insn *cmd)
324 int optlen, bits = 0;
325 struct tcphdr *tcp = L3HDR(struct tcphdr,ip);
326 u_char *cp = (u_char *)(tcp + 1);
327 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
329 for (; x > 0; x -= optlen, cp += optlen) {
331 if (opt == TCPOPT_EOL)
333 if (opt == TCPOPT_NOP)
347 bits |= IP_FW_TCPOPT_MSS;
351 bits |= IP_FW_TCPOPT_WINDOW;
354 case TCPOPT_SACK_PERMITTED:
356 bits |= IP_FW_TCPOPT_SACK;
359 case TCPOPT_TIMESTAMP:
360 bits |= IP_FW_TCPOPT_TS;
366 bits |= IP_FW_TCPOPT_CC;
370 return (flags_match(cmd, bits));
374 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
376 if (ifp == NULL) /* no iface with this packet, match fails */
378 /* Check by name or by IP address */
379 if (cmd->name[0] != '\0') { /* match by name */
382 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
385 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
391 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
392 if (ia->ifa_addr == NULL)
394 if (ia->ifa_addr->sa_family != AF_INET)
396 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
397 (ia->ifa_addr))->sin_addr.s_addr)
398 return(1); /* match */
401 return(0); /* no match, fail ... */
404 static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */
406 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
407 #define SNP(buf) buf, sizeof(buf)
410 * We enter here when we have a rule with O_LOG.
411 * XXX this function alone takes about 2Kbytes of code!
414 ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh,
415 struct mbuf *m, struct ifnet *oif)
418 int limit_reached = 0;
419 char action2[40], proto[48], fragment[28];
424 if (f == NULL) { /* bogus pkt */
425 if (verbose_limit != 0 && norule_counter >= verbose_limit)
428 if (norule_counter == verbose_limit)
429 limit_reached = verbose_limit;
431 } else { /* O_LOG is the first action, find the real one */
432 ipfw_insn *cmd = ACTION_PTR(f);
433 ipfw_insn_log *l = (ipfw_insn_log *)cmd;
435 if (l->max_log != 0 && l->log_left == 0)
438 if (l->log_left == 0)
439 limit_reached = l->max_log;
440 cmd += F_LEN(cmd); /* point to first action */
441 if (cmd->opcode == O_PROB)
445 switch (cmd->opcode) {
451 if (cmd->arg1==ICMP_REJECT_RST)
453 else if (cmd->arg1==ICMP_UNREACH_HOST)
456 snprintf(SNPARGS(action2, 0), "Unreach %d",
467 snprintf(SNPARGS(action2, 0), "Divert %d",
471 snprintf(SNPARGS(action2, 0), "Tee %d",
475 snprintf(SNPARGS(action2, 0), "SkipTo %d",
479 snprintf(SNPARGS(action2, 0), "Pipe %d",
483 snprintf(SNPARGS(action2, 0), "Queue %d",
487 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
490 len = snprintf(SNPARGS(action2, 0), "Forward to %s",
491 inet_ntoa(sa->sa.sin_addr));
493 snprintf(SNPARGS(action2, len), ":%d",
503 if (hlen == 0) { /* non-ip */
504 snprintf(SNPARGS(proto, 0), "MAC");
506 struct ip *ip = mtod(m, struct ip *);
507 /* these three are all aliases to the same thing */
508 struct icmp *const icmp = L3HDR(struct icmp, ip);
509 struct tcphdr *const tcp = (struct tcphdr *)icmp;
510 struct udphdr *const udp = (struct udphdr *)icmp;
512 int ip_off, offset, ip_len;
516 if (eh != NULL) { /* layer 2 packets are as on the wire */
517 ip_off = ntohs(ip->ip_off);
518 ip_len = ntohs(ip->ip_len);
523 offset = ip_off & IP_OFFMASK;
526 len = snprintf(SNPARGS(proto, 0), "TCP %s",
527 inet_ntoa(ip->ip_src));
529 snprintf(SNPARGS(proto, len), ":%d %s:%d",
530 ntohs(tcp->th_sport),
531 inet_ntoa(ip->ip_dst),
532 ntohs(tcp->th_dport));
534 snprintf(SNPARGS(proto, len), " %s",
535 inet_ntoa(ip->ip_dst));
539 len = snprintf(SNPARGS(proto, 0), "UDP %s",
540 inet_ntoa(ip->ip_src));
542 snprintf(SNPARGS(proto, len), ":%d %s:%d",
543 ntohs(udp->uh_sport),
544 inet_ntoa(ip->ip_dst),
545 ntohs(udp->uh_dport));
547 snprintf(SNPARGS(proto, len), " %s",
548 inet_ntoa(ip->ip_dst));
553 len = snprintf(SNPARGS(proto, 0),
555 icmp->icmp_type, icmp->icmp_code);
557 len = snprintf(SNPARGS(proto, 0), "ICMP ");
558 len += snprintf(SNPARGS(proto, len), "%s",
559 inet_ntoa(ip->ip_src));
560 snprintf(SNPARGS(proto, len), " %s",
561 inet_ntoa(ip->ip_dst));
565 len = snprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
566 inet_ntoa(ip->ip_src));
567 snprintf(SNPARGS(proto, len), " %s",
568 inet_ntoa(ip->ip_dst));
572 if (ip_off & (IP_MF | IP_OFFMASK))
573 snprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)",
574 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
576 (ip_off & IP_MF) ? "+" : "");
578 if (oif || m->m_pkthdr.rcvif)
579 log(LOG_SECURITY | LOG_INFO,
580 "ipfw: %d %s %s %s via %s%s\n",
582 action, proto, oif ? "out" : "in",
583 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
586 log(LOG_SECURITY | LOG_INFO,
587 "ipfw: %d %s %s [no if info]%s\n",
589 action, proto, fragment);
591 log(LOG_SECURITY | LOG_NOTICE,
592 "ipfw: limit %d reached on entry %d\n",
593 limit_reached, f ? f->rulenum : -1);
597 * IMPORTANT: the hash function for dynamic rules must be commutative
598 * in source and destination (ip,port), because rules are bidirectional
599 * and we want to find both in the same bucket.
602 hash_packet(struct ipfw_flow_id *id)
606 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
607 i &= (curr_dyn_buckets - 1);
612 * unlink a dynamic rule from a chain. prev is a pointer to
613 * the previous one, q is a pointer to the rule to delete,
614 * head is a pointer to the head of the queue.
615 * Modifies q and potentially also head.
617 #define UNLINK_DYN_RULE(prev, head, q) { \
618 ipfw_dyn_rule *old_q = q; \
620 /* remove a refcount to the parent */ \
621 if (q->dyn_type == O_LIMIT) \
622 q->parent->count--; \
623 DEB(printf("-- unlink entry 0x%08x %d -> 0x%08x %d, %d left\n", \
624 (q->id.src_ip), (q->id.src_port), \
625 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \
627 prev->next = q = q->next; \
629 head = q = q->next; \
631 free(old_q, M_IPFW); }
633 #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
636 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
638 * If keep_me == NULL, rules are deleted even if not expired,
639 * otherwise only expired rules are removed.
641 * The value of the second parameter is also used to point to identify
642 * a rule we absolutely do not want to remove (e.g. because we are
643 * holding a reference to it -- this is the case with O_LIMIT_PARENT
644 * rules). The pointer is only used for comparison, so any non-null
648 remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
650 static u_int32_t last_remove = 0;
652 #define FORCE (keep_me == NULL)
654 ipfw_dyn_rule *prev, *q;
655 int i, pass = 0, max_pass = 0;
657 if (ipfw_dyn_v == NULL || dyn_count == 0)
659 /* do not expire more than once per second, it is useless */
660 if (!FORCE && last_remove == time_second)
662 last_remove = time_second;
665 * because O_LIMIT refer to parent rules, during the first pass only
666 * remove child and mark any pending LIMIT_PARENT, and remove
667 * them in a second pass.
670 for (i = 0 ; i < curr_dyn_buckets ; i++) {
671 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) {
673 * Logic can become complex here, so we split tests.
677 if (rule != NULL && rule != q->rule)
678 goto next; /* not the one we are looking for */
679 if (q->dyn_type == O_LIMIT_PARENT) {
681 * handle parent in the second pass,
682 * record we need one.
687 if (FORCE && q->count != 0 ) {
688 /* XXX should not happen! */
689 printf( "OUCH! cannot remove rule,"
690 " count %d\n", q->count);
694 !TIME_LEQ( q->expire, time_second ))
697 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
704 if (pass++ < max_pass)
710 * lookup a dynamic rule.
712 static ipfw_dyn_rule *
713 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
717 * stateful ipfw extensions.
718 * Lookup into dynamic session queue
720 #define MATCH_REVERSE 0
721 #define MATCH_FORWARD 1
723 #define MATCH_UNKNOWN 3
724 int i, dir = MATCH_NONE;
725 ipfw_dyn_rule *prev, *q=NULL;
727 if (ipfw_dyn_v == NULL)
728 goto done; /* not found */
729 i = hash_packet( pkt );
730 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) {
731 if (q->dyn_type == O_LIMIT_PARENT)
733 if (TIME_LEQ( q->expire, time_second)) { /* expire entry */
734 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
737 if ( pkt->proto == q->id.proto) {
738 if (pkt->src_ip == q->id.src_ip &&
739 pkt->dst_ip == q->id.dst_ip &&
740 pkt->src_port == q->id.src_port &&
741 pkt->dst_port == q->id.dst_port ) {
745 if (pkt->src_ip == q->id.dst_ip &&
746 pkt->dst_ip == q->id.src_ip &&
747 pkt->src_port == q->id.dst_port &&
748 pkt->dst_port == q->id.src_port ) {
758 goto done; /* q = NULL, not found */
760 if ( prev != NULL) { /* found and not in front */
761 prev->next = q->next;
762 q->next = ipfw_dyn_v[i];
765 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
766 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
768 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
769 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
770 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
772 case TH_SYN: /* opening */
773 q->expire = time_second + dyn_syn_lifetime;
776 case BOTH_SYN: /* move to established */
777 case BOTH_SYN | TH_FIN : /* one side tries to close */
778 case BOTH_SYN | (TH_FIN << 8) :
780 #define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0)
781 u_int32_t ack = ntohl(tcp->th_ack);
782 if (dir == MATCH_FORWARD) {
783 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd))
785 else { /* ignore out-of-sequence */
789 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev))
791 else { /* ignore out-of-sequence */
796 q->expire = time_second + dyn_ack_lifetime;
799 case BOTH_SYN | BOTH_FIN: /* both sides closed */
800 if (dyn_fin_lifetime >= dyn_keepalive_period)
801 dyn_fin_lifetime = dyn_keepalive_period - 1;
802 q->expire = time_second + dyn_fin_lifetime;
808 * reset or some invalid combination, but can also
809 * occur if we use keep-state the wrong way.
811 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
812 printf("invalid state: 0x%x\n", q->state);
814 if (dyn_rst_lifetime >= dyn_keepalive_period)
815 dyn_rst_lifetime = dyn_keepalive_period - 1;
816 q->expire = time_second + dyn_rst_lifetime;
819 } else if (pkt->proto == IPPROTO_UDP) {
820 q->expire = time_second + dyn_udp_lifetime;
822 /* other protocols */
823 q->expire = time_second + dyn_short_lifetime;
827 *match_direction = dir;
832 realloc_dynamic_table(void)
835 * Try reallocation, make sure we have a power of 2 and do
836 * not allow more than 64k entries. In case of overflow,
840 if (dyn_buckets > 65536)
842 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */
843 dyn_buckets = curr_dyn_buckets; /* reset */
846 curr_dyn_buckets = dyn_buckets;
847 if (ipfw_dyn_v != NULL)
848 free(ipfw_dyn_v, M_IPFW);
850 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
851 M_IPFW, M_NOWAIT | M_ZERO);
852 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
854 curr_dyn_buckets /= 2;
859 * Install state of type 'type' for a dynamic session.
860 * The hash table contains two type of rules:
861 * - regular rules (O_KEEP_STATE)
862 * - rules for sessions with limited number of sess per user
863 * (O_LIMIT). When they are created, the parent is
864 * increased by 1, and decreased on delete. In this case,
865 * the third parameter is the parent rule and not the chain.
866 * - "parent" rules for the above (O_LIMIT_PARENT).
868 static ipfw_dyn_rule *
869 add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule)
874 if (ipfw_dyn_v == NULL ||
875 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
876 realloc_dynamic_table();
877 if (ipfw_dyn_v == NULL)
878 return NULL; /* failed ! */
882 r = malloc(sizeof *r, M_IPFW, M_NOWAIT | M_ZERO);
884 printf ("sorry cannot allocate state\n");
888 /* increase refcount on parent, and set pointer */
889 if (dyn_type == O_LIMIT) {
890 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
891 if ( parent->dyn_type != O_LIMIT_PARENT)
892 panic("invalid parent");
899 r->expire = time_second + dyn_syn_lifetime;
901 r->dyn_type = dyn_type;
902 r->pcnt = r->bcnt = 0;
906 r->next = ipfw_dyn_v[i];
909 DEB(printf("-- add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
911 (r->id.src_ip), (r->id.src_port),
912 (r->id.dst_ip), (r->id.dst_port),
918 * lookup dynamic parent rule using pkt and rule as search keys.
919 * If the lookup fails, then install one.
921 static ipfw_dyn_rule *
922 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
928 i = hash_packet( pkt );
929 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next)
930 if (q->dyn_type == O_LIMIT_PARENT &&
932 pkt->proto == q->id.proto &&
933 pkt->src_ip == q->id.src_ip &&
934 pkt->dst_ip == q->id.dst_ip &&
935 pkt->src_port == q->id.src_port &&
936 pkt->dst_port == q->id.dst_port) {
937 q->expire = time_second + dyn_short_lifetime;
938 DEB(printf("lookup_dyn_parent found 0x%p\n",q);)
942 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
946 * Install dynamic state for rule type cmd->o.opcode
948 * Returns 1 (failure) if state is not installed because of errors or because
949 * session limitations are enforced.
952 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
953 struct ip_fw_args *args)
959 DEB(printf("-- install state type %d 0x%08x %u -> 0x%08x %u\n",
961 (args->f_id.src_ip), (args->f_id.src_port),
962 (args->f_id.dst_ip), (args->f_id.dst_port) );)
964 q = lookup_dyn_rule(&args->f_id, NULL, NULL);
966 if (q != NULL) { /* should never occur */
967 if (last_log != time_second) {
968 last_log = time_second;
969 printf(" install_state: entry already present, done\n");
974 if (dyn_count >= dyn_max)
976 * Run out of slots, try to remove any expired rule.
978 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1);
980 if (dyn_count >= dyn_max) {
981 if (last_log != time_second) {
982 last_log = time_second;
983 printf("install_state: Too many dynamic rules\n");
985 return 1; /* cannot install, notify caller */
988 switch (cmd->o.opcode) {
989 case O_KEEP_STATE: /* bidir rule */
990 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule);
993 case O_LIMIT: /* limit number of sessions */
995 u_int16_t limit_mask = cmd->limit_mask;
996 struct ipfw_flow_id id;
997 ipfw_dyn_rule *parent;
999 DEB(printf("installing dyn-limit rule %d\n", cmd->conn_limit);)
1001 id.dst_ip = id.src_ip = 0;
1002 id.dst_port = id.src_port = 0;
1003 id.proto = args->f_id.proto;
1005 if (limit_mask & DYN_SRC_ADDR)
1006 id.src_ip = args->f_id.src_ip;
1007 if (limit_mask & DYN_DST_ADDR)
1008 id.dst_ip = args->f_id.dst_ip;
1009 if (limit_mask & DYN_SRC_PORT)
1010 id.src_port = args->f_id.src_port;
1011 if (limit_mask & DYN_DST_PORT)
1012 id.dst_port = args->f_id.dst_port;
1013 parent = lookup_dyn_parent(&id, rule);
1014 if (parent == NULL) {
1015 printf("add parent failed\n");
1018 if (parent->count >= cmd->conn_limit) {
1020 * See if we can remove some expired rule.
1022 remove_dyn_rule(rule, parent);
1023 if (parent->count >= cmd->conn_limit) {
1024 if (fw_verbose && last_log != time_second) {
1025 last_log = time_second;
1026 log(LOG_SECURITY | LOG_DEBUG,
1027 "drop session, too many entries\n");
1032 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent);
1036 printf("unknown dynamic rule type %u\n", cmd->o.opcode);
1039 lookup_dyn_rule(&args->f_id, NULL, NULL); /* XXX just set lifetime */
1044 * Transmit a TCP packet, containing either a RST or a keepalive.
1045 * When flags & TH_RST, we are sending a RST packet, because of a
1046 * "reset" action matched the packet.
1047 * Otherwise we are sending a keepalive, and flags & TH_
1050 send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags)
1055 struct route sro; /* fake route */
1057 MGETHDR(m, M_DONTWAIT, MT_HEADER);
1060 m->m_pkthdr.rcvif = (struct ifnet *)0;
1061 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
1062 m->m_data += max_linkhdr;
1064 ip = mtod(m, struct ip *);
1065 bzero(ip, m->m_len);
1066 tcp = (struct tcphdr *)(ip + 1); /* no IP options */
1067 ip->ip_p = IPPROTO_TCP;
1070 * Assume we are sending a RST (or a keepalive in the reverse
1071 * direction), swap src and destination addresses and ports.
1073 ip->ip_src.s_addr = htonl(id->dst_ip);
1074 ip->ip_dst.s_addr = htonl(id->src_ip);
1075 tcp->th_sport = htons(id->dst_port);
1076 tcp->th_dport = htons(id->src_port);
1077 if (flags & TH_RST) { /* we are sending a RST */
1078 if (flags & TH_ACK) {
1079 tcp->th_seq = htonl(ack);
1080 tcp->th_ack = htonl(0);
1081 tcp->th_flags = TH_RST;
1085 tcp->th_seq = htonl(0);
1086 tcp->th_ack = htonl(seq);
1087 tcp->th_flags = TH_RST | TH_ACK;
1091 * We are sending a keepalive. flags & TH_SYN determines
1092 * the direction, forward if set, reverse if clear.
1093 * NOTE: seq and ack are always assumed to be correct
1094 * as set by the caller. This may be confusing...
1096 if (flags & TH_SYN) {
1098 * we have to rewrite the correct addresses!
1100 ip->ip_dst.s_addr = htonl(id->dst_ip);
1101 ip->ip_src.s_addr = htonl(id->src_ip);
1102 tcp->th_dport = htons(id->dst_port);
1103 tcp->th_sport = htons(id->src_port);
1105 tcp->th_seq = htonl(seq);
1106 tcp->th_ack = htonl(ack);
1107 tcp->th_flags = TH_ACK;
1110 * set ip_len to the payload size so we can compute
1111 * the tcp checksum on the pseudoheader
1112 * XXX check this, could save a couple of words ?
1114 ip->ip_len = htons(sizeof(struct tcphdr));
1115 tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
1117 * now fill fields left out earlier
1119 ip->ip_ttl = ip_defttl;
1120 ip->ip_len = m->m_pkthdr.len;
1121 bzero (&sro, sizeof (sro));
1122 ip_rtaddr(ip->ip_dst, &sro);
1123 m->m_flags |= M_SKIP_FIREWALL;
1124 ip_output(m, NULL, &sro, 0, NULL, NULL);
1130 * sends a reject message, consuming the mbuf passed as an argument.
1133 send_reject(struct ip_fw_args *args, int code, int offset, int ip_len)
1136 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
1137 /* We need the IP header in host order for icmp_error(). */
1138 if (args->eh != NULL) {
1139 struct ip *ip = mtod(args->m, struct ip *);
1140 ip->ip_len = ntohs(ip->ip_len);
1141 ip->ip_off = ntohs(ip->ip_off);
1143 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
1144 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
1145 struct tcphdr *const tcp =
1146 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
1147 if ( (tcp->th_flags & TH_RST) == 0)
1148 send_pkt(&(args->f_id), ntohl(tcp->th_seq),
1150 tcp->th_flags | TH_RST);
1159 * Given an ip_fw *, lookup_next_rule will return a pointer
1160 * to the next rule, which can be either the jump
1161 * target (for skipto instructions) or the next one in the list (in
1162 * all other cases including a missing jump target).
1163 * The result is also written in the "next_rule" field of the rule.
1164 * Backward jumps are not allowed, so start looking from the next
1167 * This never returns NULL -- in case we do not have an exact match,
1168 * the next rule is returned. When the ruleset is changed,
1169 * pointers are flushed so we are always correct.
1172 static struct ip_fw *
1173 lookup_next_rule(struct ip_fw *me)
1175 struct ip_fw *rule = NULL;
1178 /* look for action, in case it is a skipto */
1179 cmd = ACTION_PTR(me);
1180 if (cmd->opcode == O_LOG)
1182 if ( cmd->opcode == O_SKIPTO )
1183 for (rule = me->next; rule ; rule = rule->next)
1184 if (rule->rulenum >= cmd->arg1)
1186 if (rule == NULL) /* failure or not a skipto */
1188 me->next_rule = rule;
1193 * The main check routine for the firewall.
1195 * All arguments are in args so we can modify them and return them
1196 * back to the caller.
1200 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
1201 * Starts with the IP header.
1202 * args->eh (in) Mac header if present, or NULL for layer3 packet.
1203 * args->oif Outgoing interface, or NULL if packet is incoming.
1204 * The incoming interface is in the mbuf. (in)
1205 * args->divert_rule (in/out)
1206 * Skip up to the first rule past this rule number;
1207 * upon return, non-zero port number for divert or tee.
1209 * args->rule Pointer to the last matching rule (in/out)
1210 * args->next_hop Socket we are forwarding to (out).
1211 * args->f_id Addresses grabbed from the packet (out)
1215 * IP_FW_PORT_DENY_FLAG the packet must be dropped.
1216 * 0 The packet is to be accepted and routed normally OR
1217 * the packet was denied/rejected and has been dropped;
1218 * in the latter case, *m is equal to NULL upon return.
1219 * port Divert the packet to port, with these caveats:
1221 * - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead
1222 * of diverting it (ie, 'ipfw tee').
1224 * - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower
1225 * 16 bits as a dummynet pipe number instead of diverting
1229 ipfw_chk(struct ip_fw_args *args)
1232 * Local variables hold state during the processing of a packet.
1234 * IMPORTANT NOTE: to speed up the processing of rules, there
1235 * are some assumption on the values of the variables, which
1236 * are documented here. Should you change them, please check
1237 * the implementation of the various instructions to make sure
1238 * that they still work.
1240 * args->eh The MAC header. It is non-null for a layer2
1241 * packet, it is NULL for a layer-3 packet.
1243 * m | args->m Pointer to the mbuf, as received from the caller.
1244 * It may change if ipfw_chk() does an m_pullup, or if it
1245 * consumes the packet because it calls send_reject().
1246 * XXX This has to change, so that ipfw_chk() never modifies
1247 * or consumes the buffer.
1248 * ip is simply an alias of the value of m, and it is kept
1249 * in sync with it (the packet is supposed to start with
1252 struct mbuf *m = args->m;
1253 struct ip *ip = mtod(m, struct ip *);
1256 * oif | args->oif If NULL, ipfw_chk has been called on the
1257 * inbound path (ether_input, bdg_forward, ip_input).
1258 * If non-NULL, ipfw_chk has been called on the outbound path
1259 * (ether_output, ip_output).
1261 struct ifnet *oif = args->oif;
1263 struct ip_fw *f = NULL; /* matching rule */
1267 * hlen The length of the IPv4 header.
1268 * hlen >0 means we have an IPv4 packet.
1270 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
1273 * offset The offset of a fragment. offset != 0 means that
1274 * we have a fragment at this offset of an IPv4 packet.
1275 * offset == 0 means that (if this is an IPv4 packet)
1276 * this is the first or only fragment.
1281 * Local copies of addresses. They are only valid if we have
1284 * proto The protocol. Set to 0 for non-ip packets,
1285 * or to the protocol read from the packet otherwise.
1286 * proto != 0 means that we have an IPv4 packet.
1288 * src_port, dst_port port numbers, in HOST format. Only
1289 * valid for TCP and UDP packets.
1291 * src_ip, dst_ip ip addresses, in NETWORK format.
1292 * Only valid for IPv4 packets.
1295 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */
1296 struct in_addr src_ip, dst_ip; /* NOTE: network format */
1298 int dyn_dir = MATCH_UNKNOWN;
1299 ipfw_dyn_rule *q = NULL;
1301 if (m->m_flags & M_SKIP_FIREWALL)
1302 return 0; /* accept */
1304 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
1305 * MATCH_NONE when checked and not matched (q = NULL),
1306 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
1309 if (args->eh == NULL || /* layer 3 packet */
1310 ( m->m_pkthdr.len >= sizeof(struct ip) &&
1311 ntohs(args->eh->ether_type) == ETHERTYPE_IP))
1312 hlen = ip->ip_hl << 2;
1315 * Collect parameters into local variables for faster matching.
1317 if (hlen == 0) { /* do not grab addresses for non-ip pkts */
1318 proto = args->f_id.proto = 0; /* mark f_id invalid */
1319 goto after_ip_checks;
1322 proto = args->f_id.proto = ip->ip_p;
1323 src_ip = ip->ip_src;
1324 dst_ip = ip->ip_dst;
1325 if (args->eh != NULL) { /* layer 2 packets are as on the wire */
1326 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1327 ip_len = ntohs(ip->ip_len);
1329 offset = ip->ip_off & IP_OFFMASK;
1330 ip_len = ip->ip_len;
1333 #define PULLUP_TO(len) \
1335 if ((m)->m_len < (len)) { \
1336 args->m = m = m_pullup(m, (len)); \
1338 goto pullup_failed; \
1339 ip = mtod(m, struct ip *); \
1349 PULLUP_TO(hlen + sizeof(struct tcphdr));
1350 tcp = L3HDR(struct tcphdr, ip);
1351 dst_port = tcp->th_dport;
1352 src_port = tcp->th_sport;
1353 args->f_id.flags = tcp->th_flags;
1361 PULLUP_TO(hlen + sizeof(struct udphdr));
1362 udp = L3HDR(struct udphdr, ip);
1363 dst_port = udp->uh_dport;
1364 src_port = udp->uh_sport;
1369 PULLUP_TO(hlen + 4); /* type, code and checksum. */
1370 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type;
1379 args->f_id.src_ip = ntohl(src_ip.s_addr);
1380 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1381 args->f_id.src_port = src_port = ntohs(src_port);
1382 args->f_id.dst_port = dst_port = ntohs(dst_port);
1387 * Packet has already been tagged. Look for the next rule
1388 * to restart processing.
1390 * If fw_one_pass != 0 then just accept it.
1391 * XXX should not happen here, but optimized out in
1397 f = args->rule->next_rule;
1399 f = lookup_next_rule(args->rule);
1402 * Find the starting rule. It can be either the first
1403 * one, or the one after divert_rule if asked so.
1405 int skipto = args->divert_rule;
1408 if (args->eh == NULL && skipto != 0) {
1409 if (skipto >= IPFW_DEFAULT_RULE)
1410 return(IP_FW_PORT_DENY_FLAG); /* invalid */
1411 while (f && f->rulenum <= skipto)
1413 if (f == NULL) /* drop packet */
1414 return(IP_FW_PORT_DENY_FLAG);
1417 args->divert_rule = 0; /* reset to avoid confusion later */
1420 * Now scan the rules, and parse microinstructions for each rule.
1422 for (; f; f = f->next) {
1425 int skip_or; /* skip rest of OR block */
1428 if (set_disable & (1 << f->set) )
1432 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1433 l -= cmdlen, cmd += cmdlen) {
1437 * check_body is a jump target used when we find a
1438 * CHECK_STATE, and need to jump to the body of
1443 cmdlen = F_LEN(cmd);
1445 * An OR block (insn_1 || .. || insn_n) has the
1446 * F_OR bit set in all but the last instruction.
1447 * The first match will set "skip_or", and cause
1448 * the following instructions to be skipped until
1449 * past the one with the F_OR bit clear.
1451 if (skip_or) { /* skip this instruction */
1452 if ((cmd->len & F_OR) == 0)
1453 skip_or = 0; /* next one is good */
1456 match = 0; /* set to 1 if we succeed */
1458 switch (cmd->opcode) {
1460 * The first set of opcodes compares the packet's
1461 * fields with some pattern, setting 'match' if a
1462 * match is found. At the end of the loop there is
1463 * logic to deal with F_NOT and F_OR flags associated
1471 printf("ipfw: opcode %d unimplemented\n",
1478 * We only check offset == 0 && proto != 0,
1479 * as this ensures that we have an IPv4
1480 * packet with the ports info.
1485 struct inpcbinfo *pi;
1489 if (proto == IPPROTO_TCP) {
1492 } else if (proto == IPPROTO_UDP) {
1499 in_pcblookup_hash(pi,
1500 dst_ip, htons(dst_port),
1501 src_ip, htons(src_port),
1503 in_pcblookup_hash(pi,
1504 src_ip, htons(src_port),
1505 dst_ip, htons(dst_port),
1508 if (pcb == NULL || pcb->inp_socket == NULL)
1510 #if defined(__DragonFly__) || (defined(__FreeBSD__) && __FreeBSD_version < 500034)
1511 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b))
1513 if (cmd->opcode == O_UID) {
1515 !socheckuid(pcb->inp_socket,
1516 (uid_t)((ipfw_insn_u32 *)cmd)->d[0]);
1518 match = groupmember(
1519 (uid_t)((ipfw_insn_u32 *)cmd)->d[0],
1520 pcb->inp_socket->so_cred);
1526 match = iface_match(m->m_pkthdr.rcvif,
1527 (ipfw_insn_if *)cmd);
1531 match = iface_match(oif, (ipfw_insn_if *)cmd);
1535 match = iface_match(oif ? oif :
1536 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1540 if (args->eh != NULL) { /* have MAC header */
1541 u_int32_t *want = (u_int32_t *)
1542 ((ipfw_insn_mac *)cmd)->addr;
1543 u_int32_t *mask = (u_int32_t *)
1544 ((ipfw_insn_mac *)cmd)->mask;
1545 u_int32_t *hdr = (u_int32_t *)args->eh;
1548 ( want[0] == (hdr[0] & mask[0]) &&
1549 want[1] == (hdr[1] & mask[1]) &&
1550 want[2] == (hdr[2] & mask[2]) );
1555 if (args->eh != NULL) {
1557 ntohs(args->eh->ether_type);
1559 ((ipfw_insn_u16 *)cmd)->ports;
1562 for (i = cmdlen - 1; !match && i>0;
1564 match = (t>=p[0] && t<=p[1]);
1569 match = (hlen > 0 && offset != 0);
1572 case O_IN: /* "out" is "not in" */
1573 match = (oif == NULL);
1577 match = (args->eh != NULL);
1582 * We do not allow an arg of 0 so the
1583 * check of "proto" only suffices.
1585 match = (proto == cmd->arg1);
1589 match = (hlen > 0 &&
1590 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1595 match = (hlen > 0 &&
1596 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1598 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1605 INADDR_TO_IFP(src_ip, tif);
1606 match = (tif != NULL);
1613 u_int32_t *d = (u_int32_t *)(cmd+1);
1615 cmd->opcode == O_IP_DST_SET ?
1621 addr -= d[0]; /* subtract base */
1622 match = (addr < cmd->arg1) &&
1623 ( d[ 1 + (addr>>5)] &
1624 (1<<(addr & 0x1f)) );
1629 match = (hlen > 0 &&
1630 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1635 match = (hlen > 0) &&
1636 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1638 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1645 INADDR_TO_IFP(dst_ip, tif);
1646 match = (tif != NULL);
1653 * offset == 0 && proto != 0 is enough
1654 * to guarantee that we have an IPv4
1655 * packet with port info.
1657 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1660 (cmd->opcode == O_IP_SRCPORT) ?
1661 src_port : dst_port ;
1663 ((ipfw_insn_u16 *)cmd)->ports;
1666 for (i = cmdlen - 1; !match && i>0;
1668 match = (x>=p[0] && x<=p[1]);
1673 match = (offset == 0 && proto==IPPROTO_ICMP &&
1674 icmptype_match(ip, (ipfw_insn_u32 *)cmd) );
1678 match = (hlen > 0 && ipopts_match(ip, cmd) );
1682 match = (hlen > 0 && cmd->arg1 == ip->ip_v);
1686 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl);
1690 match = (hlen > 0 &&
1691 cmd->arg1 == ntohs(ip->ip_id));
1695 match = (hlen > 0 && cmd->arg1 == ip_len);
1698 case O_IPPRECEDENCE:
1699 match = (hlen > 0 &&
1700 (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1704 match = (hlen > 0 &&
1705 flags_match(cmd, ip->ip_tos));
1709 match = (proto == IPPROTO_TCP && offset == 0 &&
1711 L3HDR(struct tcphdr,ip)->th_flags));
1715 match = (proto == IPPROTO_TCP && offset == 0 &&
1716 tcpopts_match(ip, cmd));
1720 match = (proto == IPPROTO_TCP && offset == 0 &&
1721 ((ipfw_insn_u32 *)cmd)->d[0] ==
1722 L3HDR(struct tcphdr,ip)->th_seq);
1726 match = (proto == IPPROTO_TCP && offset == 0 &&
1727 ((ipfw_insn_u32 *)cmd)->d[0] ==
1728 L3HDR(struct tcphdr,ip)->th_ack);
1732 match = (proto == IPPROTO_TCP && offset == 0 &&
1734 L3HDR(struct tcphdr,ip)->th_win);
1738 /* reject packets which have SYN only */
1739 /* XXX should i also check for TH_ACK ? */
1740 match = (proto == IPPROTO_TCP && offset == 0 &&
1741 (L3HDR(struct tcphdr,ip)->th_flags &
1742 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1747 ipfw_log(f, hlen, args->eh, m, oif);
1752 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1756 * The second set of opcodes represents 'actions',
1757 * i.e. the terminal part of a rule once the packet
1758 * matches all previous patterns.
1759 * Typically there is only one action for each rule,
1760 * and the opcode is stored at the end of the rule
1761 * (but there are exceptions -- see below).
1763 * In general, here we set retval and terminate the
1764 * outer loop (would be a 'break 3' in some language,
1765 * but we need to do a 'goto done').
1768 * O_COUNT and O_SKIPTO actions:
1769 * instead of terminating, we jump to the next rule
1770 * ('goto next_rule', equivalent to a 'break 2'),
1771 * or to the SKIPTO target ('goto again' after
1772 * having set f, cmd and l), respectively.
1774 * O_LIMIT and O_KEEP_STATE: these opcodes are
1775 * not real 'actions', and are stored right
1776 * before the 'action' part of the rule.
1777 * These opcodes try to install an entry in the
1778 * state tables; if successful, we continue with
1779 * the next opcode (match=1; break;), otherwise
1780 * the packet * must be dropped
1781 * ('goto done' after setting retval);
1783 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1784 * cause a lookup of the state table, and a jump
1785 * to the 'action' part of the parent rule
1786 * ('goto check_body') if an entry is found, or
1787 * (CHECK_STATE only) a jump to the next rule if
1788 * the entry is not found ('goto next_rule').
1789 * The result of the lookup is cached to make
1790 * further instances of these opcodes are
1795 if (install_state(f,
1796 (ipfw_insn_limit *)cmd, args)) {
1797 retval = IP_FW_PORT_DENY_FLAG;
1798 goto done; /* error/limit violation */
1806 * dynamic rules are checked at the first
1807 * keep-state or check-state occurrence,
1808 * with the result being stored in dyn_dir.
1809 * The compiler introduces a PROBE_STATE
1810 * instruction for us when we have a
1811 * KEEP_STATE (because PROBE_STATE needs
1814 if (dyn_dir == MATCH_UNKNOWN &&
1815 (q = lookup_dyn_rule(&args->f_id,
1816 &dyn_dir, proto == IPPROTO_TCP ?
1817 L3HDR(struct tcphdr, ip) : NULL))
1820 * Found dynamic entry, update stats
1821 * and jump to the 'action' part of
1827 cmd = ACTION_PTR(f);
1828 l = f->cmd_len - f->act_ofs;
1832 * Dynamic entry not found. If CHECK_STATE,
1833 * skip to next rule, if PROBE_STATE just
1834 * ignore and continue with next opcode.
1836 if (cmd->opcode == O_CHECK_STATE)
1842 retval = 0; /* accept */
1847 args->rule = f; /* report matching rule */
1848 retval = cmd->arg1 | IP_FW_PORT_DYNT_FLAG;
1853 if (args->eh) /* not on layer 2 */
1855 args->divert_rule = f->rulenum;
1856 retval = (cmd->opcode == O_DIVERT) ?
1858 cmd->arg1 | IP_FW_PORT_TEE_FLAG;
1863 f->pcnt++; /* update stats */
1865 f->timestamp = time_second;
1866 if (cmd->opcode == O_COUNT)
1869 if (f->next_rule == NULL)
1870 lookup_next_rule(f);
1876 * Drop the packet and send a reject notice
1877 * if the packet is not ICMP (or is an ICMP
1878 * query), and it is not multicast/broadcast.
1881 (proto != IPPROTO_ICMP ||
1882 is_icmp_query(ip)) &&
1883 !(m->m_flags & (M_BCAST|M_MCAST)) &&
1884 !IN_MULTICAST(dst_ip.s_addr)) {
1885 send_reject(args, cmd->arg1,
1891 retval = IP_FW_PORT_DENY_FLAG;
1895 if (args->eh) /* not valid on layer2 pkts */
1897 if (!q || dyn_dir == MATCH_FORWARD)
1899 &((ipfw_insn_sa *)cmd)->sa;
1904 panic("-- unknown opcode %d\n", cmd->opcode);
1905 } /* end of switch() on opcodes */
1907 if (cmd->len & F_NOT)
1911 if (cmd->len & F_OR)
1914 if (!(cmd->len & F_OR)) /* not an OR block, */
1915 break; /* try next rule */
1918 } /* end of inner for, scan opcodes */
1920 next_rule:; /* try next rule */
1922 } /* end of outer for, scan rules */
1923 printf("+++ ipfw: ouch!, skip past end of rules, denying packet\n");
1924 return(IP_FW_PORT_DENY_FLAG);
1927 /* Update statistics */
1930 f->timestamp = time_second;
1935 printf("pullup failed\n");
1936 return(IP_FW_PORT_DENY_FLAG);
1940 * When a rule is added/deleted, clear the next_rule pointers in all rules.
1941 * These will be reconstructed on the fly as packets are matched.
1942 * Must be called at splimp().
1945 flush_rule_ptrs(void)
1949 for (rule = layer3_chain; rule; rule = rule->next)
1950 rule->next_rule = NULL;
1954 * When pipes/queues are deleted, clear the "pipe_ptr" pointer to a given
1955 * pipe/queue, or to all of them (match == NULL).
1956 * Must be called at splimp().
1959 flush_pipe_ptrs(struct dn_flow_set *match)
1963 for (rule = layer3_chain; rule; rule = rule->next) {
1964 ipfw_insn_pipe *cmd = (ipfw_insn_pipe *)ACTION_PTR(rule);
1966 if (cmd->o.opcode != O_PIPE && cmd->o.opcode != O_QUEUE)
1968 if (match == NULL || cmd->pipe_ptr == match)
1969 cmd->pipe_ptr = NULL;
1974 * Add a new rule to the list. Copy the rule into a malloc'ed area, then
1975 * possibly create a rule number and add the rule to the list.
1976 * Update the rule_number in the input struct so the caller knows it as well.
1979 add_rule(struct ip_fw **head, struct ip_fw *input_rule)
1981 struct ip_fw *rule, *f, *prev;
1983 int l = RULESIZE(input_rule);
1985 if (*head == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE)
1988 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO);
1992 bcopy(input_rule, rule, l);
1995 rule->next_rule = NULL;
1999 rule->timestamp = 0;
2003 if (*head == NULL) { /* default rule */
2009 * If rulenum is 0, find highest numbered rule before the
2010 * default rule, and add autoinc_step
2012 if (autoinc_step < 1)
2014 else if (autoinc_step > 1000)
2015 autoinc_step = 1000;
2016 if (rule->rulenum == 0) {
2018 * locate the highest numbered rule before default
2020 for (f = *head; f; f = f->next) {
2021 if (f->rulenum == IPFW_DEFAULT_RULE)
2023 rule->rulenum = f->rulenum;
2025 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step)
2026 rule->rulenum += autoinc_step;
2027 input_rule->rulenum = rule->rulenum;
2031 * Now insert the new rule in the right place in the sorted list.
2033 for (prev = NULL, f = *head; f; prev = f, f = f->next) {
2034 if (f->rulenum > rule->rulenum) { /* found the location */
2038 } else { /* head insert */
2050 DEB(printf("++ installed rule %d, static count now %d\n",
2051 rule->rulenum, static_count);)
2056 * Free storage associated with a static rule (including derived
2058 * The caller is in charge of clearing rule pointers to avoid
2059 * dangling pointers.
2060 * @return a pointer to the next entry.
2061 * Arguments are not checked, so they better be correct.
2062 * Must be called at splimp().
2064 static struct ip_fw *
2065 delete_rule(struct ip_fw **head, struct ip_fw *prev, struct ip_fw *rule)
2068 int l = RULESIZE(rule);
2071 remove_dyn_rule(rule, NULL /* force removal */);
2079 if (DUMMYNET_LOADED)
2080 ip_dn_ruledel_ptr(rule);
2086 * Deletes all rules from a chain (including the default rule
2087 * if the second argument is set).
2088 * Must be called at splimp().
2091 free_chain(struct ip_fw **chain, int kill_default)
2095 flush_rule_ptrs(); /* more efficient to do outside the loop */
2097 while ( (rule = *chain) != NULL &&
2098 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE) )
2099 delete_rule(chain, NULL, rule);
2103 * Remove all rules with given number, and also do set manipulation.
2105 * The argument is an u_int32_t. The low 16 bit are the rule or set number,
2106 * the next 8 bits are the new set, the top 8 bits are the command:
2108 * 0 delete rules with given number
2109 * 1 delete rules with given set number
2110 * 2 move rules with given number to new set
2111 * 3 move rules with given set number to new set
2112 * 4 swap sets with given numbers
2115 del_entry(struct ip_fw **chain, u_int32_t arg)
2117 struct ip_fw *prev, *rule;
2120 u_int8_t cmd, new_set;
2122 rulenum = arg & 0xffff;
2123 cmd = (arg >> 24) & 0xff;
2124 new_set = (arg >> 16) & 0xff;
2130 if (cmd == 0 || cmd == 2) {
2131 if (rulenum == IPFW_DEFAULT_RULE)
2139 case 0: /* delete rules with given number */
2141 * locate first rule to delete
2143 for (prev = NULL, rule = *chain;
2144 rule && rule->rulenum < rulenum;
2145 prev = rule, rule = rule->next)
2147 if (rule->rulenum != rulenum)
2150 s = splimp(); /* no access to rules while removing */
2152 * flush pointers outside the loop, then delete all matching
2153 * rules. prev remains the same throughout the cycle.
2156 while (rule && rule->rulenum == rulenum)
2157 rule = delete_rule(chain, prev, rule);
2161 case 1: /* delete all rules with given set number */
2164 for (prev = NULL, rule = *chain; rule ; )
2165 if (rule->set == rulenum)
2166 rule = delete_rule(chain, prev, rule);
2174 case 2: /* move rules with given number to new set */
2176 for (rule = *chain; rule ; rule = rule->next)
2177 if (rule->rulenum == rulenum)
2178 rule->set = new_set;
2182 case 3: /* move rules with given set number to new set */
2184 for (rule = *chain; rule ; rule = rule->next)
2185 if (rule->set == rulenum)
2186 rule->set = new_set;
2190 case 4: /* swap two sets */
2192 for (rule = *chain; rule ; rule = rule->next)
2193 if (rule->set == rulenum)
2194 rule->set = new_set;
2195 else if (rule->set == new_set)
2196 rule->set = rulenum;
2204 * Clear counters for a specific rule.
2207 clear_counters(struct ip_fw *rule, int log_only)
2209 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
2211 if (log_only == 0) {
2212 rule->bcnt = rule->pcnt = 0;
2213 rule->timestamp = 0;
2215 if (l->o.opcode == O_LOG)
2216 l->log_left = l->max_log;
2220 * Reset some or all counters on firewall rules.
2221 * @arg frwl is null to clear all entries, or contains a specific
2223 * @arg log_only is 1 if we only want to reset logs, zero otherwise.
2226 zero_entry(int rulenum, int log_only)
2235 for (rule = layer3_chain; rule; rule = rule->next)
2236 clear_counters(rule, log_only);
2238 msg = log_only ? "ipfw: All logging counts reset.\n" :
2239 "ipfw: Accounting cleared.\n";
2243 * We can have multiple rules with the same number, so we
2244 * need to clear them all.
2246 for (rule = layer3_chain; rule; rule = rule->next)
2247 if (rule->rulenum == rulenum) {
2249 while (rule && rule->rulenum == rulenum) {
2250 clear_counters(rule, log_only);
2257 if (!cleared) /* we did not find any matching rules */
2259 msg = log_only ? "ipfw: Entry %d logging count reset.\n" :
2260 "ipfw: Entry %d cleared.\n";
2263 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
2268 * Check validity of the structure before insert.
2269 * Fortunately rules are simple, so this mostly need to check rule sizes.
2272 check_ipfw_struct(struct ip_fw *rule, int size)
2278 if (size < sizeof(*rule)) {
2279 printf("ipfw: rule too short\n");
2282 /* first, check for valid size */
2285 printf("ipfw: size mismatch (have %d want %d)\n", size, l);
2289 * Now go for the individual checks. Very simple ones, basically only
2290 * instruction sizes.
2292 for (l = rule->cmd_len, cmd = rule->cmd ;
2293 l > 0 ; l -= cmdlen, cmd += cmdlen) {
2294 cmdlen = F_LEN(cmd);
2296 printf("ipfw: opcode %d size truncated\n",
2300 DEB(printf("ipfw: opcode %d\n", cmd->opcode);)
2301 switch (cmd->opcode) {
2315 case O_IPPRECEDENCE:
2322 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2334 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
2339 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
2344 if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
2347 ((ipfw_insn_log *)cmd)->log_left =
2348 ((ipfw_insn_log *)cmd)->max_log;
2354 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip))
2356 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) {
2357 printf("ipfw: opcode %d, useless rule\n",
2365 if (cmd->arg1 == 0 || cmd->arg1 > 256) {
2366 printf("ipfw: invalid set size %d\n",
2370 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
2376 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
2382 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
2383 if (cmdlen < 2 || cmdlen > 31)
2390 if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
2396 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
2401 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
2405 case O_FORWARD_MAC: /* XXX not implemented yet */
2414 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2418 printf("ipfw: opcode %d, multiple actions"
2425 printf("ipfw: opcode %d, action must be"
2432 printf("ipfw: opcode %d, unknown opcode\n",
2437 if (have_action == 0) {
2438 printf("ipfw: missing action\n");
2444 printf("ipfw: opcode %d size %d wrong\n",
2445 cmd->opcode, cmdlen);
2451 * {set|get}sockopt parser.
2454 ipfw_ctl(struct sockopt *sopt)
2456 int error, s, rulenum;
2458 struct ip_fw *bp , *buf, *rule;
2460 static u_int32_t rule_buf[255]; /* we copy the data here */
2463 * Disallow modifications in really-really secure mode, but still allow
2464 * the logging counters to be reset.
2466 if (sopt->sopt_name == IP_FW_ADD ||
2467 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) {
2468 #if defined(__FreeBSD__) && __FreeBSD_version >= 500034
2469 error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
2472 #else /* FreeBSD 4.x */
2473 if (securelevel >= 3)
2480 switch (sopt->sopt_name) {
2483 * pass up a copy of the current rules. Static rules
2484 * come first (the last of which has number IPFW_DEFAULT_RULE),
2485 * followed by a possibly empty list of dynamic rule.
2486 * The last dynamic rule has NULL in the "next" field.
2489 size = static_len; /* size of static rules */
2490 if (ipfw_dyn_v) /* add size of dyn.rules */
2491 size += (dyn_count * sizeof(ipfw_dyn_rule));
2494 * XXX todo: if the user passes a short length just to know
2495 * how much room is needed, do not bother filling up the
2496 * buffer, just jump to the sooptcopyout.
2498 buf = malloc(size, M_TEMP, M_WAITOK);
2506 for (rule = layer3_chain; rule ; rule = rule->next) {
2507 int i = RULESIZE(rule);
2510 * abuse 'next_rule' to store the set_disable word
2512 (u_int32_t)(((struct ip_fw *)bp)->next_rule) =
2514 bp = (struct ip_fw *)((char *)bp + i);
2518 ipfw_dyn_rule *p, *dst, *last = NULL;
2520 dst = (ipfw_dyn_rule *)bp;
2521 for (i = 0 ; i < curr_dyn_buckets ; i++ )
2522 for ( p = ipfw_dyn_v[i] ; p != NULL ;
2523 p = p->next, dst++ ) {
2524 bcopy(p, dst, sizeof *p);
2525 (int)dst->rule = p->rule->rulenum ;
2527 * store a non-null value in "next".
2528 * The userland code will interpret a
2529 * NULL here as a marker
2530 * for the last dynamic rule.
2535 TIME_LEQ(dst->expire, time_second) ?
2536 0 : dst->expire - time_second ;
2538 if (last != NULL) /* mark last dynamic rule */
2543 error = sooptcopyout(sopt, buf, size);
2549 * Normally we cannot release the lock on each iteration.
2550 * We could do it here only because we start from the head all
2551 * the times so there is no risk of missing some entries.
2552 * On the other hand, the risk is that we end up with
2553 * a very inconsistent ruleset, so better keep the lock
2554 * around the whole cycle.
2556 * XXX this code can be improved by resetting the head of
2557 * the list to point to the default rule, and then freeing
2558 * the old list without the need for a lock.
2562 free_chain(&layer3_chain, 0 /* keep default rule */);
2567 rule = (struct ip_fw *)rule_buf; /* XXX do a malloc */
2568 error = sooptcopyin(sopt, rule, sizeof(rule_buf),
2569 sizeof(struct ip_fw) );
2570 size = sopt->sopt_valsize;
2571 if (error || (error = check_ipfw_struct(rule, size)))
2574 error = add_rule(&layer3_chain, rule);
2575 size = RULESIZE(rule);
2576 if (!error && sopt->sopt_dir == SOPT_GET)
2577 error = sooptcopyout(sopt, rule, size);
2582 * IP_FW_DEL is used for deleting single rules or sets,
2583 * and (ab)used to atomically manipulate sets. Argument size
2584 * is used to distinguish between the two:
2586 * delete single rule or set of rules,
2587 * or reassign rules (or sets) to a different set.
2588 * 2*sizeof(u_int32_t)
2589 * atomic disable/enable sets.
2590 * first u_int32_t contains sets to be disabled,
2591 * second u_int32_t contains sets to be enabled.
2593 error = sooptcopyin(sopt, rule_buf,
2594 2*sizeof(u_int32_t), sizeof(u_int32_t));
2597 size = sopt->sopt_valsize;
2598 if (size == sizeof(u_int32_t)) /* delete or reassign */
2599 error = del_entry(&layer3_chain, rule_buf[0]);
2600 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */
2602 (set_disable | rule_buf[0]) & ~rule_buf[1] &
2603 ~(1<<31); /* set 31 always enabled */
2609 case IP_FW_RESETLOG: /* argument is an int, the rule number */
2612 if (sopt->sopt_val != 0) {
2613 error = sooptcopyin(sopt, &rulenum,
2614 sizeof(int), sizeof(int));
2618 error = zero_entry(rulenum, sopt->sopt_name == IP_FW_RESETLOG);
2622 printf("ipfw_ctl invalid option %d\n", sopt->sopt_name);
2630 * dummynet needs a reference to the default rule, because rules can be
2631 * deleted while packets hold a reference to them. When this happens,
2632 * dummynet changes the reference to the default rule (it could well be a
2633 * NULL pointer, but this way we do not need to check for the special
2634 * case, plus here he have info on the default behaviour).
2636 struct ip_fw *ip_fw_default_rule;
2639 * This procedure is only used to handle keepalives. It is invoked
2640 * every dyn_keepalive_period
2643 ipfw_tick(void * __unused unused)
2649 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0)
2653 for (i = 0 ; i < curr_dyn_buckets ; i++) {
2654 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) {
2655 if (q->dyn_type == O_LIMIT_PARENT)
2657 if (q->id.proto != IPPROTO_TCP)
2659 if ( (q->state & BOTH_SYN) != BOTH_SYN)
2661 if (TIME_LEQ( time_second+dyn_keepalive_interval,
2663 continue; /* too early */
2664 if (TIME_LEQ(q->expire, time_second))
2665 continue; /* too late, rule expired */
2667 send_pkt(&(q->id), q->ack_rev - 1, q->ack_fwd, TH_SYN);
2668 send_pkt(&(q->id), q->ack_fwd - 1, q->ack_rev, 0);
2673 ipfw_timeout_h = timeout(ipfw_tick, NULL, dyn_keepalive_period*hz);
2679 struct ip_fw default_rule;
2681 ip_fw_chk_ptr = ipfw_chk;
2682 ip_fw_ctl_ptr = ipfw_ctl;
2683 layer3_chain = NULL;
2685 bzero(&default_rule, sizeof default_rule);
2687 default_rule.act_ofs = 0;
2688 default_rule.rulenum = IPFW_DEFAULT_RULE;
2689 default_rule.cmd_len = 1;
2690 default_rule.set = 31;
2692 default_rule.cmd[0].len = 1;
2693 default_rule.cmd[0].opcode =
2694 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
2699 add_rule(&layer3_chain, &default_rule);
2701 ip_fw_default_rule = layer3_chain;
2702 printf("ipfw2 initialized, divert %s, "
2703 "rule-based forwarding enabled, default to %s, logging ",
2709 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny");
2711 #ifdef IPFIREWALL_VERBOSE
2714 #ifdef IPFIREWALL_VERBOSE_LIMIT
2715 verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2717 if (fw_verbose == 0)
2718 printf("disabled\n");
2719 else if (verbose_limit == 0)
2720 printf("unlimited\n");
2722 printf("limited to %d packets/entry by default\n",
2724 bzero(&ipfw_timeout_h, sizeof(struct callout_handle));
2725 ipfw_timeout_h = timeout(ipfw_tick, NULL, hz);
2729 ipfw_modevent(module_t mod, int type, void *unused)
2739 printf("IP firewall already loaded\n");
2748 #if !defined(KLD_MODULE)
2749 printf("ipfw statically compiled, cannot unload\n");
2753 untimeout(ipfw_tick, NULL, ipfw_timeout_h);
2754 ip_fw_chk_ptr = NULL;
2755 ip_fw_ctl_ptr = NULL;
2756 free_chain(&layer3_chain, 1 /* kill default rule */);
2758 printf("IP firewall unloaded\n");
2767 static moduledata_t ipfwmod = {
2772 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2773 MODULE_VERSION(ipfw, 1);