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 1.23 2006/09/30 20:23:05 swildner 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/thread2.h>
58 #include <sys/ucred.h>
59 #include <sys/in_cksum.h>
61 #include <net/route.h>
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/in_var.h>
65 #include <netinet/in_pcb.h>
66 #include <netinet/ip.h>
67 #include <netinet/ip_var.h>
68 #include <netinet/ip_icmp.h>
70 #include <net/dummynet/ip_dummynet.h>
71 #include <netinet/tcp.h>
72 #include <netinet/tcp_timer.h>
73 #include <netinet/tcp_var.h>
74 #include <netinet/tcpip.h>
75 #include <netinet/udp.h>
76 #include <netinet/udp_var.h>
78 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
81 * set_disable contains one bit per set value (0..31).
82 * If the bit is set, all rules with the corresponding set
83 * are disabled. Set 31 is reserved for the default rule
84 * and CANNOT be disabled.
86 static u_int32_t set_disable;
88 static int fw_verbose;
89 static int verbose_limit;
91 static struct callout ipfw_timeout_h;
92 #define IPFW_DEFAULT_RULE 65535
95 * list of rules for layer 3
97 static struct ip_fw *layer3_chain;
99 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
101 static int fw_debug = 1;
102 static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
105 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
106 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_RW,
107 &fw_enable, 0, "Enable ipfw");
108 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW,
109 &autoinc_step, 0, "Rule number autincrement step");
110 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
112 "Only do a single pass through ipfw when using dummynet(4)");
113 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
114 &fw_debug, 0, "Enable printing of debug ip_fw statements");
115 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
116 &fw_verbose, 0, "Log matches to ipfw rules");
117 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
118 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
121 * Description of dynamic rules.
123 * Dynamic rules are stored in lists accessed through a hash table
124 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
125 * be modified through the sysctl variable dyn_buckets which is
126 * updated when the table becomes empty.
128 * XXX currently there is only one list, ipfw_dyn.
130 * When a packet is received, its address fields are first masked
131 * with the mask defined for the rule, then hashed, then matched
132 * against the entries in the corresponding list.
133 * Dynamic rules can be used for different purposes:
135 * + enforcing limits on the number of sessions;
136 * + in-kernel NAT (not implemented yet)
138 * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
139 * measured in seconds and depending on the flags.
141 * The total number of dynamic rules is stored in dyn_count.
142 * The max number of dynamic rules is dyn_max. When we reach
143 * the maximum number of rules we do not create anymore. This is
144 * done to avoid consuming too much memory, but also too much
145 * time when searching on each packet (ideally, we should try instead
146 * to put a limit on the length of the list on each bucket...).
148 * Each dynamic rule holds a pointer to the parent ipfw rule so
149 * we know what action to perform. Dynamic rules are removed when
150 * the parent rule is deleted. XXX we should make them survive.
152 * There are some limitations with dynamic rules -- we do not
153 * obey the 'randomized match', and we do not do multiple
154 * passes through the firewall. XXX check the latter!!!
156 static ipfw_dyn_rule **ipfw_dyn_v = NULL;
157 static u_int32_t dyn_buckets = 256; /* must be power of 2 */
158 static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */
161 * Timeouts for various events in handing dynamic rules.
163 static u_int32_t dyn_ack_lifetime = 300;
164 static u_int32_t dyn_syn_lifetime = 20;
165 static u_int32_t dyn_fin_lifetime = 1;
166 static u_int32_t dyn_rst_lifetime = 1;
167 static u_int32_t dyn_udp_lifetime = 10;
168 static u_int32_t dyn_short_lifetime = 5;
171 * Keepalives are sent if dyn_keepalive is set. They are sent every
172 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
173 * seconds of lifetime of a rule.
174 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
175 * than dyn_keepalive_period.
178 static u_int32_t dyn_keepalive_interval = 20;
179 static u_int32_t dyn_keepalive_period = 5;
180 static u_int32_t dyn_keepalive = 1; /* do send keepalives */
182 static u_int32_t static_count; /* # of static rules */
183 static u_int32_t static_len; /* size in bytes of static rules */
184 static u_int32_t dyn_count; /* # of dynamic rules */
185 static u_int32_t dyn_max = 4096; /* max # of dynamic rules */
187 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
188 &dyn_buckets, 0, "Number of dyn. buckets");
189 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
190 &curr_dyn_buckets, 0, "Current Number of dyn. buckets");
191 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
192 &dyn_count, 0, "Number of dyn. rules");
193 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
194 &dyn_max, 0, "Max number of dyn. rules");
195 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
196 &static_count, 0, "Number of static rules");
197 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
198 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
199 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
200 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
201 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
202 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
203 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
204 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
205 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
206 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
207 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
208 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
209 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
210 &dyn_keepalive, 0, "Enable keepalives for dyn. rules");
212 #endif /* SYSCTL_NODE */
215 static ip_fw_chk_t ipfw_chk;
217 ip_dn_ruledel_t *ip_dn_ruledel_ptr = NULL; /* hook into dummynet */
220 * This macro maps an ip pointer into a layer3 header pointer of type T
222 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
225 icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd)
227 int type = L3HDR(struct icmp,ip)->icmp_type;
229 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
232 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
233 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
236 is_icmp_query(struct ip *ip)
238 int type = L3HDR(struct icmp, ip)->icmp_type;
239 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
244 * The following checks use two arrays of 8 or 16 bits to store the
245 * bits that we want set or clear, respectively. They are in the
246 * low and high half of cmd->arg1 or cmd->d[0].
248 * We scan options and store the bits we find set. We succeed if
250 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
252 * The code is sometimes optimized not to store additional variables.
256 flags_match(ipfw_insn *cmd, u_int8_t bits)
261 if ( ((cmd->arg1 & 0xff) & bits) != 0)
262 return 0; /* some bits we want set were clear */
263 want_clear = (cmd->arg1 >> 8) & 0xff;
264 if ( (want_clear & bits) != want_clear)
265 return 0; /* some bits we want clear were set */
270 ipopts_match(struct ip *ip, ipfw_insn *cmd)
272 int optlen, bits = 0;
273 u_char *cp = (u_char *)(ip + 1);
274 int x = (ip->ip_hl << 2) - sizeof (struct ip);
276 for (; x > 0; x -= optlen, cp += optlen) {
277 int opt = cp[IPOPT_OPTVAL];
279 if (opt == IPOPT_EOL)
281 if (opt == IPOPT_NOP)
284 optlen = cp[IPOPT_OLEN];
285 if (optlen <= 0 || optlen > x)
286 return 0; /* invalid or truncated */
294 bits |= IP_FW_IPOPT_LSRR;
298 bits |= IP_FW_IPOPT_SSRR;
302 bits |= IP_FW_IPOPT_RR;
306 bits |= IP_FW_IPOPT_TS;
310 return (flags_match(cmd, bits));
314 tcpopts_match(struct ip *ip, ipfw_insn *cmd)
316 int optlen, bits = 0;
317 struct tcphdr *tcp = L3HDR(struct tcphdr,ip);
318 u_char *cp = (u_char *)(tcp + 1);
319 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
321 for (; x > 0; x -= optlen, cp += optlen) {
323 if (opt == TCPOPT_EOL)
325 if (opt == TCPOPT_NOP)
339 bits |= IP_FW_TCPOPT_MSS;
343 bits |= IP_FW_TCPOPT_WINDOW;
346 case TCPOPT_SACK_PERMITTED:
348 bits |= IP_FW_TCPOPT_SACK;
351 case TCPOPT_TIMESTAMP:
352 bits |= IP_FW_TCPOPT_TS;
358 bits |= IP_FW_TCPOPT_CC;
362 return (flags_match(cmd, bits));
366 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
368 if (ifp == NULL) /* no iface with this packet, match fails */
370 /* Check by name or by IP address */
371 if (cmd->name[0] != '\0') { /* match by name */
374 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
377 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
383 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
384 if (ia->ifa_addr == NULL)
386 if (ia->ifa_addr->sa_family != AF_INET)
388 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
389 (ia->ifa_addr))->sin_addr.s_addr)
390 return(1); /* match */
393 return(0); /* no match, fail ... */
396 static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */
398 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
399 #define SNP(buf) buf, sizeof(buf)
402 * We enter here when we have a rule with O_LOG.
403 * XXX this function alone takes about 2Kbytes of code!
406 ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh,
407 struct mbuf *m, struct ifnet *oif)
410 int limit_reached = 0;
411 char action2[40], proto[48], fragment[28];
416 if (f == NULL) { /* bogus pkt */
417 if (verbose_limit != 0 && norule_counter >= verbose_limit)
420 if (norule_counter == verbose_limit)
421 limit_reached = verbose_limit;
423 } else { /* O_LOG is the first action, find the real one */
424 ipfw_insn *cmd = ACTION_PTR(f);
425 ipfw_insn_log *l = (ipfw_insn_log *)cmd;
427 if (l->max_log != 0 && l->log_left == 0)
430 if (l->log_left == 0)
431 limit_reached = l->max_log;
432 cmd += F_LEN(cmd); /* point to first action */
433 if (cmd->opcode == O_PROB)
437 switch (cmd->opcode) {
443 if (cmd->arg1==ICMP_REJECT_RST)
445 else if (cmd->arg1==ICMP_UNREACH_HOST)
448 snprintf(SNPARGS(action2, 0), "Unreach %d",
459 snprintf(SNPARGS(action2, 0), "Divert %d",
463 snprintf(SNPARGS(action2, 0), "Tee %d",
467 snprintf(SNPARGS(action2, 0), "SkipTo %d",
471 snprintf(SNPARGS(action2, 0), "Pipe %d",
475 snprintf(SNPARGS(action2, 0), "Queue %d",
479 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
482 len = snprintf(SNPARGS(action2, 0), "Forward to %s",
483 inet_ntoa(sa->sa.sin_addr));
485 snprintf(SNPARGS(action2, len), ":%d",
495 if (hlen == 0) { /* non-ip */
496 snprintf(SNPARGS(proto, 0), "MAC");
498 struct ip *ip = mtod(m, struct ip *);
499 /* these three are all aliases to the same thing */
500 struct icmp *const icmp = L3HDR(struct icmp, ip);
501 struct tcphdr *const tcp = (struct tcphdr *)icmp;
502 struct udphdr *const udp = (struct udphdr *)icmp;
504 int ip_off, offset, ip_len;
508 if (eh != NULL) { /* layer 2 packets are as on the wire */
509 ip_off = ntohs(ip->ip_off);
510 ip_len = ntohs(ip->ip_len);
515 offset = ip_off & IP_OFFMASK;
518 len = snprintf(SNPARGS(proto, 0), "TCP %s",
519 inet_ntoa(ip->ip_src));
521 snprintf(SNPARGS(proto, len), ":%d %s:%d",
522 ntohs(tcp->th_sport),
523 inet_ntoa(ip->ip_dst),
524 ntohs(tcp->th_dport));
526 snprintf(SNPARGS(proto, len), " %s",
527 inet_ntoa(ip->ip_dst));
531 len = snprintf(SNPARGS(proto, 0), "UDP %s",
532 inet_ntoa(ip->ip_src));
534 snprintf(SNPARGS(proto, len), ":%d %s:%d",
535 ntohs(udp->uh_sport),
536 inet_ntoa(ip->ip_dst),
537 ntohs(udp->uh_dport));
539 snprintf(SNPARGS(proto, len), " %s",
540 inet_ntoa(ip->ip_dst));
545 len = snprintf(SNPARGS(proto, 0),
547 icmp->icmp_type, icmp->icmp_code);
549 len = snprintf(SNPARGS(proto, 0), "ICMP ");
550 len += snprintf(SNPARGS(proto, len), "%s",
551 inet_ntoa(ip->ip_src));
552 snprintf(SNPARGS(proto, len), " %s",
553 inet_ntoa(ip->ip_dst));
557 len = snprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
558 inet_ntoa(ip->ip_src));
559 snprintf(SNPARGS(proto, len), " %s",
560 inet_ntoa(ip->ip_dst));
564 if (ip_off & (IP_MF | IP_OFFMASK))
565 snprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)",
566 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
568 (ip_off & IP_MF) ? "+" : "");
570 if (oif || m->m_pkthdr.rcvif)
571 log(LOG_SECURITY | LOG_INFO,
572 "ipfw: %d %s %s %s via %s%s\n",
574 action, proto, oif ? "out" : "in",
575 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
578 log(LOG_SECURITY | LOG_INFO,
579 "ipfw: %d %s %s [no if info]%s\n",
581 action, proto, fragment);
583 log(LOG_SECURITY | LOG_NOTICE,
584 "ipfw: limit %d reached on entry %d\n",
585 limit_reached, f ? f->rulenum : -1);
589 * IMPORTANT: the hash function for dynamic rules must be commutative
590 * in source and destination (ip,port), because rules are bidirectional
591 * and we want to find both in the same bucket.
594 hash_packet(struct ipfw_flow_id *id)
598 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
599 i &= (curr_dyn_buckets - 1);
604 * unlink a dynamic rule from a chain. prev is a pointer to
605 * the previous one, q is a pointer to the rule to delete,
606 * head is a pointer to the head of the queue.
607 * Modifies q and potentially also head.
609 #define UNLINK_DYN_RULE(prev, head, q) { \
610 ipfw_dyn_rule *old_q = q; \
612 /* remove a refcount to the parent */ \
613 if (q->dyn_type == O_LIMIT) \
614 q->parent->count--; \
615 DEB(printf("-- unlink entry 0x%08x %d -> 0x%08x %d, %d left\n", \
616 (q->id.src_ip), (q->id.src_port), \
617 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \
619 prev->next = q = q->next; \
621 head = q = q->next; \
623 kfree(old_q, M_IPFW); }
625 #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
628 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
630 * If keep_me == NULL, rules are deleted even if not expired,
631 * otherwise only expired rules are removed.
633 * The value of the second parameter is also used to point to identify
634 * a rule we absolutely do not want to remove (e.g. because we are
635 * holding a reference to it -- this is the case with O_LIMIT_PARENT
636 * rules). The pointer is only used for comparison, so any non-null
640 remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
642 static u_int32_t last_remove = 0;
644 #define FORCE (keep_me == NULL)
646 ipfw_dyn_rule *prev, *q;
647 int i, pass = 0, max_pass = 0;
649 if (ipfw_dyn_v == NULL || dyn_count == 0)
651 /* do not expire more than once per second, it is useless */
652 if (!FORCE && last_remove == time_second)
654 last_remove = time_second;
657 * because O_LIMIT refer to parent rules, during the first pass only
658 * remove child and mark any pending LIMIT_PARENT, and remove
659 * them in a second pass.
662 for (i = 0 ; i < curr_dyn_buckets ; i++) {
663 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) {
665 * Logic can become complex here, so we split tests.
669 if (rule != NULL && rule != q->rule)
670 goto next; /* not the one we are looking for */
671 if (q->dyn_type == O_LIMIT_PARENT) {
673 * handle parent in the second pass,
674 * record we need one.
679 if (FORCE && q->count != 0 ) {
680 /* XXX should not happen! */
681 printf( "OUCH! cannot remove rule,"
682 " count %d\n", q->count);
686 !TIME_LEQ( q->expire, time_second ))
689 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
696 if (pass++ < max_pass)
702 * lookup a dynamic rule.
704 static ipfw_dyn_rule *
705 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
709 * stateful ipfw extensions.
710 * Lookup into dynamic session queue
712 #define MATCH_REVERSE 0
713 #define MATCH_FORWARD 1
715 #define MATCH_UNKNOWN 3
716 int i, dir = MATCH_NONE;
717 ipfw_dyn_rule *prev, *q=NULL;
719 if (ipfw_dyn_v == NULL)
720 goto done; /* not found */
721 i = hash_packet( pkt );
722 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) {
723 if (q->dyn_type == O_LIMIT_PARENT)
725 if (TIME_LEQ( q->expire, time_second)) { /* expire entry */
726 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
729 if ( pkt->proto == q->id.proto) {
730 if (pkt->src_ip == q->id.src_ip &&
731 pkt->dst_ip == q->id.dst_ip &&
732 pkt->src_port == q->id.src_port &&
733 pkt->dst_port == q->id.dst_port ) {
737 if (pkt->src_ip == q->id.dst_ip &&
738 pkt->dst_ip == q->id.src_ip &&
739 pkt->src_port == q->id.dst_port &&
740 pkt->dst_port == q->id.src_port ) {
750 goto done; /* q = NULL, not found */
752 if ( prev != NULL) { /* found and not in front */
753 prev->next = q->next;
754 q->next = ipfw_dyn_v[i];
757 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
758 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
760 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
761 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
762 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
764 case TH_SYN: /* opening */
765 q->expire = time_second + dyn_syn_lifetime;
768 case BOTH_SYN: /* move to established */
769 case BOTH_SYN | TH_FIN : /* one side tries to close */
770 case BOTH_SYN | (TH_FIN << 8) :
772 #define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0)
773 u_int32_t ack = ntohl(tcp->th_ack);
774 if (dir == MATCH_FORWARD) {
775 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd))
777 else { /* ignore out-of-sequence */
781 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev))
783 else { /* ignore out-of-sequence */
788 q->expire = time_second + dyn_ack_lifetime;
791 case BOTH_SYN | BOTH_FIN: /* both sides closed */
792 if (dyn_fin_lifetime >= dyn_keepalive_period)
793 dyn_fin_lifetime = dyn_keepalive_period - 1;
794 q->expire = time_second + dyn_fin_lifetime;
800 * reset or some invalid combination, but can also
801 * occur if we use keep-state the wrong way.
803 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
804 printf("invalid state: 0x%x\n", q->state);
806 if (dyn_rst_lifetime >= dyn_keepalive_period)
807 dyn_rst_lifetime = dyn_keepalive_period - 1;
808 q->expire = time_second + dyn_rst_lifetime;
811 } else if (pkt->proto == IPPROTO_UDP) {
812 q->expire = time_second + dyn_udp_lifetime;
814 /* other protocols */
815 q->expire = time_second + dyn_short_lifetime;
819 *match_direction = dir;
824 realloc_dynamic_table(void)
827 * Try reallocation, make sure we have a power of 2 and do
828 * not allow more than 64k entries. In case of overflow,
832 if (dyn_buckets > 65536)
834 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */
835 dyn_buckets = curr_dyn_buckets; /* reset */
838 curr_dyn_buckets = dyn_buckets;
839 if (ipfw_dyn_v != NULL)
840 kfree(ipfw_dyn_v, M_IPFW);
842 ipfw_dyn_v = kmalloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
843 M_IPFW, M_WAITOK | M_ZERO);
844 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
846 curr_dyn_buckets /= 2;
851 * Install state of type 'type' for a dynamic session.
852 * The hash table contains two type of rules:
853 * - regular rules (O_KEEP_STATE)
854 * - rules for sessions with limited number of sess per user
855 * (O_LIMIT). When they are created, the parent is
856 * increased by 1, and decreased on delete. In this case,
857 * the third parameter is the parent rule and not the chain.
858 * - "parent" rules for the above (O_LIMIT_PARENT).
860 static ipfw_dyn_rule *
861 add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule)
866 if (ipfw_dyn_v == NULL ||
867 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
868 realloc_dynamic_table();
869 if (ipfw_dyn_v == NULL)
870 return NULL; /* failed ! */
874 r = kmalloc(sizeof *r, M_IPFW, M_WAITOK | M_ZERO);
876 printf ("sorry cannot allocate state\n");
880 /* increase refcount on parent, and set pointer */
881 if (dyn_type == O_LIMIT) {
882 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
883 if ( parent->dyn_type != O_LIMIT_PARENT)
884 panic("invalid parent");
891 r->expire = time_second + dyn_syn_lifetime;
893 r->dyn_type = dyn_type;
894 r->pcnt = r->bcnt = 0;
898 r->next = ipfw_dyn_v[i];
901 DEB(printf("-- add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
903 (r->id.src_ip), (r->id.src_port),
904 (r->id.dst_ip), (r->id.dst_port),
910 * lookup dynamic parent rule using pkt and rule as search keys.
911 * If the lookup fails, then install one.
913 static ipfw_dyn_rule *
914 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
920 i = hash_packet( pkt );
921 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next)
922 if (q->dyn_type == O_LIMIT_PARENT &&
924 pkt->proto == q->id.proto &&
925 pkt->src_ip == q->id.src_ip &&
926 pkt->dst_ip == q->id.dst_ip &&
927 pkt->src_port == q->id.src_port &&
928 pkt->dst_port == q->id.dst_port) {
929 q->expire = time_second + dyn_short_lifetime;
930 DEB(printf("lookup_dyn_parent found 0x%p\n",q);)
934 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
938 * Install dynamic state for rule type cmd->o.opcode
940 * Returns 1 (failure) if state is not installed because of errors or because
941 * session limitations are enforced.
944 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
945 struct ip_fw_args *args)
951 DEB(printf("-- install state type %d 0x%08x %u -> 0x%08x %u\n",
953 (args->f_id.src_ip), (args->f_id.src_port),
954 (args->f_id.dst_ip), (args->f_id.dst_port) );)
956 q = lookup_dyn_rule(&args->f_id, NULL, NULL);
958 if (q != NULL) { /* should never occur */
959 if (last_log != time_second) {
960 last_log = time_second;
961 printf(" install_state: entry already present, done\n");
966 if (dyn_count >= dyn_max)
968 * Run out of slots, try to remove any expired rule.
970 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1);
972 if (dyn_count >= dyn_max) {
973 if (last_log != time_second) {
974 last_log = time_second;
975 printf("install_state: Too many dynamic rules\n");
977 return 1; /* cannot install, notify caller */
980 switch (cmd->o.opcode) {
981 case O_KEEP_STATE: /* bidir rule */
982 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule);
985 case O_LIMIT: /* limit number of sessions */
987 u_int16_t limit_mask = cmd->limit_mask;
988 struct ipfw_flow_id id;
989 ipfw_dyn_rule *parent;
991 DEB(printf("installing dyn-limit rule %d\n", cmd->conn_limit);)
993 id.dst_ip = id.src_ip = 0;
994 id.dst_port = id.src_port = 0;
995 id.proto = args->f_id.proto;
997 if (limit_mask & DYN_SRC_ADDR)
998 id.src_ip = args->f_id.src_ip;
999 if (limit_mask & DYN_DST_ADDR)
1000 id.dst_ip = args->f_id.dst_ip;
1001 if (limit_mask & DYN_SRC_PORT)
1002 id.src_port = args->f_id.src_port;
1003 if (limit_mask & DYN_DST_PORT)
1004 id.dst_port = args->f_id.dst_port;
1005 parent = lookup_dyn_parent(&id, rule);
1006 if (parent == NULL) {
1007 printf("add parent failed\n");
1010 if (parent->count >= cmd->conn_limit) {
1012 * See if we can remove some expired rule.
1014 remove_dyn_rule(rule, parent);
1015 if (parent->count >= cmd->conn_limit) {
1016 if (fw_verbose && last_log != time_second) {
1017 last_log = time_second;
1018 log(LOG_SECURITY | LOG_DEBUG,
1019 "drop session, too many entries\n");
1024 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent);
1028 printf("unknown dynamic rule type %u\n", cmd->o.opcode);
1031 lookup_dyn_rule(&args->f_id, NULL, NULL); /* XXX just set lifetime */
1036 * Transmit a TCP packet, containing either a RST or a keepalive.
1037 * When flags & TH_RST, we are sending a RST packet, because of a
1038 * "reset" action matched the packet.
1039 * Otherwise we are sending a keepalive, and flags & TH_
1042 send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags)
1047 struct route sro; /* fake route */
1049 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1052 m->m_pkthdr.rcvif = (struct ifnet *)0;
1053 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
1054 m->m_data += max_linkhdr;
1056 ip = mtod(m, struct ip *);
1057 bzero(ip, m->m_len);
1058 tcp = (struct tcphdr *)(ip + 1); /* no IP options */
1059 ip->ip_p = IPPROTO_TCP;
1062 * Assume we are sending a RST (or a keepalive in the reverse
1063 * direction), swap src and destination addresses and ports.
1065 ip->ip_src.s_addr = htonl(id->dst_ip);
1066 ip->ip_dst.s_addr = htonl(id->src_ip);
1067 tcp->th_sport = htons(id->dst_port);
1068 tcp->th_dport = htons(id->src_port);
1069 if (flags & TH_RST) { /* we are sending a RST */
1070 if (flags & TH_ACK) {
1071 tcp->th_seq = htonl(ack);
1072 tcp->th_ack = htonl(0);
1073 tcp->th_flags = TH_RST;
1077 tcp->th_seq = htonl(0);
1078 tcp->th_ack = htonl(seq);
1079 tcp->th_flags = TH_RST | TH_ACK;
1083 * We are sending a keepalive. flags & TH_SYN determines
1084 * the direction, forward if set, reverse if clear.
1085 * NOTE: seq and ack are always assumed to be correct
1086 * as set by the caller. This may be confusing...
1088 if (flags & TH_SYN) {
1090 * we have to rewrite the correct addresses!
1092 ip->ip_dst.s_addr = htonl(id->dst_ip);
1093 ip->ip_src.s_addr = htonl(id->src_ip);
1094 tcp->th_dport = htons(id->dst_port);
1095 tcp->th_sport = htons(id->src_port);
1097 tcp->th_seq = htonl(seq);
1098 tcp->th_ack = htonl(ack);
1099 tcp->th_flags = TH_ACK;
1102 * set ip_len to the payload size so we can compute
1103 * the tcp checksum on the pseudoheader
1104 * XXX check this, could save a couple of words ?
1106 ip->ip_len = htons(sizeof(struct tcphdr));
1107 tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
1109 * now fill fields left out earlier
1111 ip->ip_ttl = ip_defttl;
1112 ip->ip_len = m->m_pkthdr.len;
1113 bzero (&sro, sizeof (sro));
1114 ip_rtaddr(ip->ip_dst, &sro);
1115 m->m_pkthdr.fw_flags |= IPFW_MBUF_SKIP_FIREWALL;
1116 ip_output(m, NULL, &sro, 0, NULL, NULL);
1122 * sends a reject message, consuming the mbuf passed as an argument.
1125 send_reject(struct ip_fw_args *args, int code, int offset, int ip_len)
1128 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
1129 /* We need the IP header in host order for icmp_error(). */
1130 if (args->eh != NULL) {
1131 struct ip *ip = mtod(args->m, struct ip *);
1132 ip->ip_len = ntohs(ip->ip_len);
1133 ip->ip_off = ntohs(ip->ip_off);
1135 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
1136 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
1137 struct tcphdr *const tcp =
1138 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
1139 if ( (tcp->th_flags & TH_RST) == 0)
1140 send_pkt(&(args->f_id), ntohl(tcp->th_seq),
1142 tcp->th_flags | TH_RST);
1151 * Given an ip_fw *, lookup_next_rule will return a pointer
1152 * to the next rule, which can be either the jump
1153 * target (for skipto instructions) or the next one in the list (in
1154 * all other cases including a missing jump target).
1155 * The result is also written in the "next_rule" field of the rule.
1156 * Backward jumps are not allowed, so start looking from the next
1159 * This never returns NULL -- in case we do not have an exact match,
1160 * the next rule is returned. When the ruleset is changed,
1161 * pointers are flushed so we are always correct.
1164 static struct ip_fw *
1165 lookup_next_rule(struct ip_fw *me)
1167 struct ip_fw *rule = NULL;
1170 /* look for action, in case it is a skipto */
1171 cmd = ACTION_PTR(me);
1172 if (cmd->opcode == O_LOG)
1174 if ( cmd->opcode == O_SKIPTO )
1175 for (rule = me->next; rule ; rule = rule->next)
1176 if (rule->rulenum >= cmd->arg1)
1178 if (rule == NULL) /* failure or not a skipto */
1180 me->next_rule = rule;
1185 * The main check routine for the firewall.
1187 * All arguments are in args so we can modify them and return them
1188 * back to the caller.
1192 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
1193 * Starts with the IP header.
1194 * args->eh (in) Mac header if present, or NULL for layer3 packet.
1195 * args->oif Outgoing interface, or NULL if packet is incoming.
1196 * The incoming interface is in the mbuf. (in)
1198 * args->rule Pointer to the last matching rule (in/out)
1199 * args->next_hop Socket we are forwarding to (out).
1200 * args->f_id Addresses grabbed from the packet (out)
1204 * IP_FW_PORT_DENY_FLAG the packet must be dropped.
1205 * 0 The packet is to be accepted and routed normally OR
1206 * the packet was denied/rejected and has been dropped;
1207 * in the latter case, *m is equal to NULL upon return.
1208 * port Divert the packet to port, with these caveats:
1210 * - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead
1211 * of diverting it (ie, 'ipfw tee').
1213 * - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower
1214 * 16 bits as a dummynet pipe number instead of diverting
1218 ipfw_chk(struct ip_fw_args *args)
1221 * Local variables hold state during the processing of a packet.
1223 * IMPORTANT NOTE: to speed up the processing of rules, there
1224 * are some assumption on the values of the variables, which
1225 * are documented here. Should you change them, please check
1226 * the implementation of the various instructions to make sure
1227 * that they still work.
1229 * args->eh The MAC header. It is non-null for a layer2
1230 * packet, it is NULL for a layer-3 packet.
1232 * m | args->m Pointer to the mbuf, as received from the caller.
1233 * It may change if ipfw_chk() does an m_pullup, or if it
1234 * consumes the packet because it calls send_reject().
1235 * XXX This has to change, so that ipfw_chk() never modifies
1236 * or consumes the buffer.
1237 * ip is simply an alias of the value of m, and it is kept
1238 * in sync with it (the packet is supposed to start with
1241 struct mbuf *m = args->m;
1242 struct ip *ip = mtod(m, struct ip *);
1245 * oif | args->oif If NULL, ipfw_chk has been called on the
1246 * inbound path (ether_input, ip_input).
1247 * If non-NULL, ipfw_chk has been called on the outbound path
1248 * (ether_output, ip_output).
1250 struct ifnet *oif = args->oif;
1252 struct ip_fw *f = NULL; /* matching rule */
1257 * hlen The length of the IPv4 header.
1258 * hlen >0 means we have an IPv4 packet.
1260 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
1263 * offset The offset of a fragment. offset != 0 means that
1264 * we have a fragment at this offset of an IPv4 packet.
1265 * offset == 0 means that (if this is an IPv4 packet)
1266 * this is the first or only fragment.
1271 * Local copies of addresses. They are only valid if we have
1274 * proto The protocol. Set to 0 for non-ip packets,
1275 * or to the protocol read from the packet otherwise.
1276 * proto != 0 means that we have an IPv4 packet.
1278 * src_port, dst_port port numbers, in HOST format. Only
1279 * valid for TCP and UDP packets.
1281 * src_ip, dst_ip ip addresses, in NETWORK format.
1282 * Only valid for IPv4 packets.
1285 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */
1286 struct in_addr src_ip, dst_ip; /* NOTE: network format */
1288 int dyn_dir = MATCH_UNKNOWN;
1289 ipfw_dyn_rule *q = NULL;
1291 if (m->m_pkthdr.fw_flags & IPFW_MBUF_SKIP_FIREWALL)
1292 return 0; /* accept */
1294 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
1295 * MATCH_NONE when checked and not matched (q = NULL),
1296 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
1299 if (args->eh == NULL || /* layer 3 packet */
1300 ( m->m_pkthdr.len >= sizeof(struct ip) &&
1301 ntohs(args->eh->ether_type) == ETHERTYPE_IP))
1302 hlen = ip->ip_hl << 2;
1305 * Collect parameters into local variables for faster matching.
1307 if (hlen == 0) { /* do not grab addresses for non-ip pkts */
1308 proto = args->f_id.proto = 0; /* mark f_id invalid */
1309 goto after_ip_checks;
1312 proto = args->f_id.proto = ip->ip_p;
1313 src_ip = ip->ip_src;
1314 dst_ip = ip->ip_dst;
1315 if (args->eh != NULL) { /* layer 2 packets are as on the wire */
1316 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1317 ip_len = ntohs(ip->ip_len);
1319 offset = ip->ip_off & IP_OFFMASK;
1320 ip_len = ip->ip_len;
1323 #define PULLUP_TO(len) \
1325 if ((m)->m_len < (len)) { \
1326 args->m = m = m_pullup(m, (len)); \
1328 goto pullup_failed; \
1329 ip = mtod(m, struct ip *); \
1339 PULLUP_TO(hlen + sizeof(struct tcphdr));
1340 tcp = L3HDR(struct tcphdr, ip);
1341 dst_port = tcp->th_dport;
1342 src_port = tcp->th_sport;
1343 args->f_id.flags = tcp->th_flags;
1351 PULLUP_TO(hlen + sizeof(struct udphdr));
1352 udp = L3HDR(struct udphdr, ip);
1353 dst_port = udp->uh_dport;
1354 src_port = udp->uh_sport;
1359 PULLUP_TO(hlen + 4); /* type, code and checksum. */
1360 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type;
1369 args->f_id.src_ip = ntohl(src_ip.s_addr);
1370 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1371 args->f_id.src_port = src_port = ntohs(src_port);
1372 args->f_id.dst_port = dst_port = ntohs(dst_port);
1377 * Packet has already been tagged. Look for the next rule
1378 * to restart processing.
1380 * If fw_one_pass != 0 then just accept it.
1381 * XXX should not happen here, but optimized out in
1387 f = args->rule->next_rule;
1389 f = lookup_next_rule(args->rule);
1392 * Find the starting rule. It can be either the first
1393 * one, or the one after divert_rule if asked so.
1397 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
1399 skipto = *(u_int16_t *)m_tag_data(mtag);
1404 if (args->eh == NULL && skipto != 0) {
1405 if (skipto >= IPFW_DEFAULT_RULE)
1406 return(IP_FW_PORT_DENY_FLAG); /* invalid */
1407 while (f && f->rulenum <= skipto)
1409 if (f == NULL) /* drop packet */
1410 return(IP_FW_PORT_DENY_FLAG);
1413 if ((mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL)
1414 m_tag_delete(m, mtag);
1417 * Now scan the rules, and parse microinstructions for each rule.
1419 for (; f; f = f->next) {
1422 int skip_or; /* skip rest of OR block */
1425 if (set_disable & (1 << f->set) )
1429 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1430 l -= cmdlen, cmd += cmdlen) {
1434 * check_body is a jump target used when we find a
1435 * CHECK_STATE, and need to jump to the body of
1440 cmdlen = F_LEN(cmd);
1442 * An OR block (insn_1 || .. || insn_n) has the
1443 * F_OR bit set in all but the last instruction.
1444 * The first match will set "skip_or", and cause
1445 * the following instructions to be skipped until
1446 * past the one with the F_OR bit clear.
1448 if (skip_or) { /* skip this instruction */
1449 if ((cmd->len & F_OR) == 0)
1450 skip_or = 0; /* next one is good */
1453 match = 0; /* set to 1 if we succeed */
1455 switch (cmd->opcode) {
1457 * The first set of opcodes compares the packet's
1458 * fields with some pattern, setting 'match' if a
1459 * match is found. At the end of the loop there is
1460 * logic to deal with F_NOT and F_OR flags associated
1468 printf("ipfw: opcode %d unimplemented\n",
1475 * We only check offset == 0 && proto != 0,
1476 * as this ensures that we have an IPv4
1477 * packet with the ports info.
1482 struct inpcbinfo *pi;
1486 if (proto == IPPROTO_TCP) {
1488 pi = &tcbinfo[mycpu->gd_cpuid];
1489 } else if (proto == IPPROTO_UDP) {
1496 in_pcblookup_hash(pi,
1497 dst_ip, htons(dst_port),
1498 src_ip, htons(src_port),
1500 in_pcblookup_hash(pi,
1501 src_ip, htons(src_port),
1502 dst_ip, htons(dst_port),
1505 if (pcb == NULL || pcb->inp_socket == NULL)
1507 #if defined(__DragonFly__) || (defined(__FreeBSD__) && __FreeBSD_version < 500034)
1508 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b))
1510 if (cmd->opcode == O_UID) {
1512 !socheckuid(pcb->inp_socket,
1513 (uid_t)((ipfw_insn_u32 *)cmd)->d[0]);
1515 match = groupmember(
1516 (uid_t)((ipfw_insn_u32 *)cmd)->d[0],
1517 pcb->inp_socket->so_cred);
1523 match = iface_match(m->m_pkthdr.rcvif,
1524 (ipfw_insn_if *)cmd);
1528 match = iface_match(oif, (ipfw_insn_if *)cmd);
1532 match = iface_match(oif ? oif :
1533 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1537 if (args->eh != NULL) { /* have MAC header */
1538 u_int32_t *want = (u_int32_t *)
1539 ((ipfw_insn_mac *)cmd)->addr;
1540 u_int32_t *mask = (u_int32_t *)
1541 ((ipfw_insn_mac *)cmd)->mask;
1542 u_int32_t *hdr = (u_int32_t *)args->eh;
1545 ( want[0] == (hdr[0] & mask[0]) &&
1546 want[1] == (hdr[1] & mask[1]) &&
1547 want[2] == (hdr[2] & mask[2]) );
1552 if (args->eh != NULL) {
1554 ntohs(args->eh->ether_type);
1556 ((ipfw_insn_u16 *)cmd)->ports;
1559 for (i = cmdlen - 1; !match && i>0;
1561 match = (t>=p[0] && t<=p[1]);
1566 match = (hlen > 0 && offset != 0);
1569 case O_IN: /* "out" is "not in" */
1570 match = (oif == NULL);
1574 match = (args->eh != NULL);
1579 * We do not allow an arg of 0 so the
1580 * check of "proto" only suffices.
1582 match = (proto == cmd->arg1);
1586 match = (hlen > 0 &&
1587 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1592 match = (hlen > 0 &&
1593 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1595 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1602 INADDR_TO_IFP(src_ip, tif);
1603 match = (tif != NULL);
1610 u_int32_t *d = (u_int32_t *)(cmd+1);
1612 cmd->opcode == O_IP_DST_SET ?
1618 addr -= d[0]; /* subtract base */
1619 match = (addr < cmd->arg1) &&
1620 ( d[ 1 + (addr>>5)] &
1621 (1<<(addr & 0x1f)) );
1626 match = (hlen > 0 &&
1627 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1632 match = (hlen > 0) &&
1633 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1635 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1642 INADDR_TO_IFP(dst_ip, tif);
1643 match = (tif != NULL);
1650 * offset == 0 && proto != 0 is enough
1651 * to guarantee that we have an IPv4
1652 * packet with port info.
1654 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1657 (cmd->opcode == O_IP_SRCPORT) ?
1658 src_port : dst_port ;
1660 ((ipfw_insn_u16 *)cmd)->ports;
1663 for (i = cmdlen - 1; !match && i>0;
1665 match = (x>=p[0] && x<=p[1]);
1670 match = (offset == 0 && proto==IPPROTO_ICMP &&
1671 icmptype_match(ip, (ipfw_insn_u32 *)cmd) );
1675 match = (hlen > 0 && ipopts_match(ip, cmd) );
1679 match = (hlen > 0 && cmd->arg1 == ip->ip_v);
1683 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl);
1687 match = (hlen > 0 &&
1688 cmd->arg1 == ntohs(ip->ip_id));
1692 match = (hlen > 0 && cmd->arg1 == ip_len);
1695 case O_IPPRECEDENCE:
1696 match = (hlen > 0 &&
1697 (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1701 match = (hlen > 0 &&
1702 flags_match(cmd, ip->ip_tos));
1706 match = (proto == IPPROTO_TCP && offset == 0 &&
1708 L3HDR(struct tcphdr,ip)->th_flags));
1712 match = (proto == IPPROTO_TCP && offset == 0 &&
1713 tcpopts_match(ip, cmd));
1717 match = (proto == IPPROTO_TCP && offset == 0 &&
1718 ((ipfw_insn_u32 *)cmd)->d[0] ==
1719 L3HDR(struct tcphdr,ip)->th_seq);
1723 match = (proto == IPPROTO_TCP && offset == 0 &&
1724 ((ipfw_insn_u32 *)cmd)->d[0] ==
1725 L3HDR(struct tcphdr,ip)->th_ack);
1729 match = (proto == IPPROTO_TCP && offset == 0 &&
1731 L3HDR(struct tcphdr,ip)->th_win);
1735 /* reject packets which have SYN only */
1736 /* XXX should i also check for TH_ACK ? */
1737 match = (proto == IPPROTO_TCP && offset == 0 &&
1738 (L3HDR(struct tcphdr,ip)->th_flags &
1739 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1744 ipfw_log(f, hlen, args->eh, m, oif);
1749 match = (krandom() <
1750 ((ipfw_insn_u32 *)cmd)->d[0]);
1754 * The second set of opcodes represents 'actions',
1755 * i.e. the terminal part of a rule once the packet
1756 * matches all previous patterns.
1757 * Typically there is only one action for each rule,
1758 * and the opcode is stored at the end of the rule
1759 * (but there are exceptions -- see below).
1761 * In general, here we set retval and terminate the
1762 * outer loop (would be a 'break 3' in some language,
1763 * but we need to do a 'goto done').
1766 * O_COUNT and O_SKIPTO actions:
1767 * instead of terminating, we jump to the next rule
1768 * ('goto next_rule', equivalent to a 'break 2'),
1769 * or to the SKIPTO target ('goto again' after
1770 * having set f, cmd and l), respectively.
1772 * O_LIMIT and O_KEEP_STATE: these opcodes are
1773 * not real 'actions', and are stored right
1774 * before the 'action' part of the rule.
1775 * These opcodes try to install an entry in the
1776 * state tables; if successful, we continue with
1777 * the next opcode (match=1; break;), otherwise
1778 * the packet * must be dropped
1779 * ('goto done' after setting retval);
1781 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1782 * cause a lookup of the state table, and a jump
1783 * to the 'action' part of the parent rule
1784 * ('goto check_body') if an entry is found, or
1785 * (CHECK_STATE only) a jump to the next rule if
1786 * the entry is not found ('goto next_rule').
1787 * The result of the lookup is cached to make
1788 * further instances of these opcodes are
1793 if (install_state(f,
1794 (ipfw_insn_limit *)cmd, args)) {
1795 retval = IP_FW_PORT_DENY_FLAG;
1796 goto done; /* error/limit violation */
1804 * dynamic rules are checked at the first
1805 * keep-state or check-state occurrence,
1806 * with the result being stored in dyn_dir.
1807 * The compiler introduces a PROBE_STATE
1808 * instruction for us when we have a
1809 * KEEP_STATE (because PROBE_STATE needs
1812 if (dyn_dir == MATCH_UNKNOWN &&
1813 (q = lookup_dyn_rule(&args->f_id,
1814 &dyn_dir, proto == IPPROTO_TCP ?
1815 L3HDR(struct tcphdr, ip) : NULL))
1818 * Found dynamic entry, update stats
1819 * and jump to the 'action' part of
1825 cmd = ACTION_PTR(f);
1826 l = f->cmd_len - f->act_ofs;
1830 * Dynamic entry not found. If CHECK_STATE,
1831 * skip to next rule, if PROBE_STATE just
1832 * ignore and continue with next opcode.
1834 if (cmd->opcode == O_CHECK_STATE)
1840 retval = 0; /* accept */
1845 args->rule = f; /* report matching rule */
1846 retval = cmd->arg1 | IP_FW_PORT_DYNT_FLAG;
1851 if (args->eh) /* not on layer 2 */
1854 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT,
1855 sizeof(u_int16_t), M_NOWAIT);
1857 retval = IP_FW_PORT_DENY_FLAG;
1860 *(u_int16_t *)m_tag_data(mtag) = f->rulenum;
1861 m_tag_prepend(m, mtag);
1862 retval = (cmd->opcode == O_DIVERT) ?
1864 cmd->arg1 | IP_FW_PORT_TEE_FLAG;
1869 f->pcnt++; /* update stats */
1871 f->timestamp = time_second;
1872 if (cmd->opcode == O_COUNT)
1875 if (f->next_rule == NULL)
1876 lookup_next_rule(f);
1882 * Drop the packet and send a reject notice
1883 * if the packet is not ICMP (or is an ICMP
1884 * query), and it is not multicast/broadcast.
1887 (proto != IPPROTO_ICMP ||
1888 is_icmp_query(ip)) &&
1889 !(m->m_flags & (M_BCAST|M_MCAST)) &&
1890 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
1891 send_reject(args, cmd->arg1,
1897 retval = IP_FW_PORT_DENY_FLAG;
1901 if (args->eh) /* not valid on layer2 pkts */
1903 if (!q || dyn_dir == MATCH_FORWARD)
1905 &((ipfw_insn_sa *)cmd)->sa;
1910 panic("-- unknown opcode %d\n", cmd->opcode);
1911 } /* end of switch() on opcodes */
1913 if (cmd->len & F_NOT)
1917 if (cmd->len & F_OR)
1920 if (!(cmd->len & F_OR)) /* not an OR block, */
1921 break; /* try next rule */
1924 } /* end of inner for, scan opcodes */
1926 next_rule:; /* try next rule */
1928 } /* end of outer for, scan rules */
1929 printf("+++ ipfw: ouch!, skip past end of rules, denying packet\n");
1930 return(IP_FW_PORT_DENY_FLAG);
1933 /* Update statistics */
1936 f->timestamp = time_second;
1941 printf("pullup failed\n");
1942 return(IP_FW_PORT_DENY_FLAG);
1946 * When a rule is added/deleted, clear the next_rule pointers in all rules.
1947 * These will be reconstructed on the fly as packets are matched.
1948 * Must be called at splimp().
1951 flush_rule_ptrs(void)
1955 for (rule = layer3_chain; rule; rule = rule->next)
1956 rule->next_rule = NULL;
1960 * When pipes/queues are deleted, clear the "pipe_ptr" pointer to a given
1961 * pipe/queue, or to all of them (match == NULL).
1962 * Must be called at splimp().
1965 flush_pipe_ptrs(struct dn_flow_set *match)
1969 for (rule = layer3_chain; rule; rule = rule->next) {
1970 ipfw_insn_pipe *cmd = (ipfw_insn_pipe *)ACTION_PTR(rule);
1972 if (cmd->o.opcode != O_PIPE && cmd->o.opcode != O_QUEUE)
1974 if (match == NULL || cmd->pipe_ptr == match)
1975 cmd->pipe_ptr = NULL;
1980 * Add a new rule to the list. Copy the rule into a malloc'ed area, then
1981 * possibly create a rule number and add the rule to the list.
1982 * Update the rule_number in the input struct so the caller knows it as well.
1985 add_rule(struct ip_fw **head, struct ip_fw *input_rule)
1987 struct ip_fw *rule, *f, *prev;
1988 int l = RULESIZE(input_rule);
1990 if (*head == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE)
1993 rule = kmalloc(l, M_IPFW, M_WAITOK | M_ZERO);
1997 bcopy(input_rule, rule, l);
2000 rule->next_rule = NULL;
2004 rule->timestamp = 0;
2008 if (*head == NULL) { /* default rule */
2014 * If rulenum is 0, find highest numbered rule before the
2015 * default rule, and add autoinc_step
2017 if (autoinc_step < 1)
2019 else if (autoinc_step > 1000)
2020 autoinc_step = 1000;
2021 if (rule->rulenum == 0) {
2023 * locate the highest numbered rule before default
2025 for (f = *head; f; f = f->next) {
2026 if (f->rulenum == IPFW_DEFAULT_RULE)
2028 rule->rulenum = f->rulenum;
2030 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step)
2031 rule->rulenum += autoinc_step;
2032 input_rule->rulenum = rule->rulenum;
2036 * Now insert the new rule in the right place in the sorted list.
2038 for (prev = NULL, f = *head; f; prev = f, f = f->next) {
2039 if (f->rulenum > rule->rulenum) { /* found the location */
2043 } else { /* head insert */
2055 DEB(printf("++ installed rule %d, static count now %d\n",
2056 rule->rulenum, static_count);)
2061 * Free storage associated with a static rule (including derived
2063 * The caller is in charge of clearing rule pointers to avoid
2064 * dangling pointers.
2065 * @return a pointer to the next entry.
2066 * Arguments are not checked, so they better be correct.
2067 * Must be called at splimp().
2069 static struct ip_fw *
2070 delete_rule(struct ip_fw **head, struct ip_fw *prev, struct ip_fw *rule)
2073 int l = RULESIZE(rule);
2076 remove_dyn_rule(rule, NULL /* force removal */);
2084 if (DUMMYNET_LOADED)
2085 ip_dn_ruledel_ptr(rule);
2086 kfree(rule, M_IPFW);
2091 * Deletes all rules from a chain (including the default rule
2092 * if the second argument is set).
2093 * Must be called at splimp().
2096 free_chain(struct ip_fw **chain, int kill_default)
2100 flush_rule_ptrs(); /* more efficient to do outside the loop */
2102 while ( (rule = *chain) != NULL &&
2103 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE) )
2104 delete_rule(chain, NULL, rule);
2108 * Remove all rules with given number, and also do set manipulation.
2110 * The argument is an u_int32_t. The low 16 bit are the rule or set number,
2111 * the next 8 bits are the new set, the top 8 bits are the command:
2113 * 0 delete rules with given number
2114 * 1 delete rules with given set number
2115 * 2 move rules with given number to new set
2116 * 3 move rules with given set number to new set
2117 * 4 swap sets with given numbers
2120 del_entry(struct ip_fw **chain, u_int32_t arg)
2122 struct ip_fw *prev, *rule;
2124 u_int8_t cmd, new_set;
2126 rulenum = arg & 0xffff;
2127 cmd = (arg >> 24) & 0xff;
2128 new_set = (arg >> 16) & 0xff;
2134 if (cmd == 0 || cmd == 2) {
2135 if (rulenum == IPFW_DEFAULT_RULE)
2143 case 0: /* delete rules with given number */
2145 * locate first rule to delete
2147 for (prev = NULL, rule = *chain;
2148 rule && rule->rulenum < rulenum;
2149 prev = rule, rule = rule->next)
2151 if (rule->rulenum != rulenum)
2154 crit_enter(); /* no access to rules while removing */
2156 * flush pointers outside the loop, then delete all matching
2157 * rules. prev remains the same throughout the cycle.
2160 while (rule && rule->rulenum == rulenum)
2161 rule = delete_rule(chain, prev, rule);
2165 case 1: /* delete all rules with given set number */
2168 for (prev = NULL, rule = *chain; rule ; )
2169 if (rule->set == rulenum)
2170 rule = delete_rule(chain, prev, rule);
2178 case 2: /* move rules with given number to new set */
2180 for (rule = *chain; rule ; rule = rule->next)
2181 if (rule->rulenum == rulenum)
2182 rule->set = new_set;
2186 case 3: /* move rules with given set number to new set */
2188 for (rule = *chain; rule ; rule = rule->next)
2189 if (rule->set == rulenum)
2190 rule->set = new_set;
2194 case 4: /* swap two sets */
2196 for (rule = *chain; rule ; rule = rule->next)
2197 if (rule->set == rulenum)
2198 rule->set = new_set;
2199 else if (rule->set == new_set)
2200 rule->set = rulenum;
2208 * Clear counters for a specific rule.
2211 clear_counters(struct ip_fw *rule, int log_only)
2213 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
2215 if (log_only == 0) {
2216 rule->bcnt = rule->pcnt = 0;
2217 rule->timestamp = 0;
2219 if (l->o.opcode == O_LOG)
2220 l->log_left = l->max_log;
2224 * Reset some or all counters on firewall rules.
2225 * @arg frwl is null to clear all entries, or contains a specific
2227 * @arg log_only is 1 if we only want to reset logs, zero otherwise.
2230 zero_entry(int rulenum, int log_only)
2238 for (rule = layer3_chain; rule; rule = rule->next)
2239 clear_counters(rule, log_only);
2241 msg = log_only ? "ipfw: All logging counts reset.\n" :
2242 "ipfw: Accounting cleared.\n";
2246 * We can have multiple rules with the same number, so we
2247 * need to clear them all.
2249 for (rule = layer3_chain; rule; rule = rule->next)
2250 if (rule->rulenum == rulenum) {
2252 while (rule && rule->rulenum == rulenum) {
2253 clear_counters(rule, log_only);
2260 if (!cleared) /* we did not find any matching rules */
2262 msg = log_only ? "ipfw: Entry %d logging count reset.\n" :
2263 "ipfw: Entry %d cleared.\n";
2266 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
2271 * Check validity of the structure before insert.
2272 * Fortunately rules are simple, so this mostly need to check rule sizes.
2275 check_ipfw_struct(struct ip_fw *rule, int size)
2281 if (size < sizeof(*rule)) {
2282 printf("ipfw: rule too short\n");
2285 /* first, check for valid size */
2288 printf("ipfw: size mismatch (have %d want %d)\n", size, l);
2292 * Now go for the individual checks. Very simple ones, basically only
2293 * instruction sizes.
2295 for (l = rule->cmd_len, cmd = rule->cmd ;
2296 l > 0 ; l -= cmdlen, cmd += cmdlen) {
2297 cmdlen = F_LEN(cmd);
2299 printf("ipfw: opcode %d size truncated\n",
2303 DEB(printf("ipfw: opcode %d\n", cmd->opcode);)
2304 switch (cmd->opcode) {
2318 case O_IPPRECEDENCE:
2325 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2337 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
2342 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
2347 if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
2350 ((ipfw_insn_log *)cmd)->log_left =
2351 ((ipfw_insn_log *)cmd)->max_log;
2357 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip))
2359 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) {
2360 printf("ipfw: opcode %d, useless rule\n",
2368 if (cmd->arg1 == 0 || cmd->arg1 > 256) {
2369 printf("ipfw: invalid set size %d\n",
2373 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
2379 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
2385 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
2386 if (cmdlen < 2 || cmdlen > 31)
2393 if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
2399 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
2404 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
2408 case O_FORWARD_MAC: /* XXX not implemented yet */
2417 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2421 printf("ipfw: opcode %d, multiple actions"
2428 printf("ipfw: opcode %d, action must be"
2435 printf("ipfw: opcode %d, unknown opcode\n",
2440 if (have_action == 0) {
2441 printf("ipfw: missing action\n");
2447 printf("ipfw: opcode %d size %d wrong\n",
2448 cmd->opcode, cmdlen);
2454 * {set|get}sockopt parser.
2457 ipfw_ctl(struct sockopt *sopt)
2461 struct ip_fw *bp , *buf, *rule;
2463 static u_int32_t rule_buf[255]; /* we copy the data here */
2466 * Disallow modifications in really-really secure mode, but still allow
2467 * the logging counters to be reset.
2469 if (sopt->sopt_name == IP_FW_ADD ||
2470 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) {
2471 #if defined(__FreeBSD__) && __FreeBSD_version >= 500034
2472 error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
2475 #else /* FreeBSD 4.x */
2476 if (securelevel >= 3)
2483 switch (sopt->sopt_name) {
2486 * pass up a copy of the current rules. Static rules
2487 * come first (the last of which has number IPFW_DEFAULT_RULE),
2488 * followed by a possibly empty list of dynamic rule.
2489 * The last dynamic rule has NULL in the "next" field.
2492 size = static_len; /* size of static rules */
2493 if (ipfw_dyn_v) /* add size of dyn.rules */
2494 size += (dyn_count * sizeof(ipfw_dyn_rule));
2497 * XXX todo: if the user passes a short length just to know
2498 * how much room is needed, do not bother filling up the
2499 * buffer, just jump to the sooptcopyout.
2501 buf = kmalloc(size, M_TEMP, M_WAITOK);
2504 for (rule = layer3_chain; rule ; rule = rule->next) {
2505 int i = RULESIZE(rule);
2508 * abuse 'next_rule' to store the set_disable word
2510 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule),
2511 sizeof(set_disable));
2512 bp = (struct ip_fw *)((char *)bp + i);
2516 ipfw_dyn_rule *p, *dst, *last = NULL;
2518 dst = (ipfw_dyn_rule *)bp;
2519 for (i = 0 ; i < curr_dyn_buckets ; i++ )
2520 for ( p = ipfw_dyn_v[i] ; p != NULL ;
2521 p = p->next, dst++ ) {
2522 bcopy(p, dst, sizeof *p);
2523 bcopy(&(p->rule->rulenum), &(dst->rule),
2524 sizeof(p->rule->rulenum));
2526 * store a non-null value in "next".
2527 * The userland code will interpret a
2528 * NULL here as a marker
2529 * for the last dynamic rule.
2534 TIME_LEQ(dst->expire, time_second) ?
2535 0 : dst->expire - time_second ;
2537 if (last != NULL) /* mark last dynamic rule */
2542 error = sooptcopyout(sopt, buf, size);
2548 * Normally we cannot release the lock on each iteration.
2549 * We could do it here only because we start from the head all
2550 * the times so there is no risk of missing some entries.
2551 * On the other hand, the risk is that we end up with
2552 * a very inconsistent ruleset, so better keep the lock
2553 * around the whole cycle.
2555 * XXX this code can be improved by resetting the head of
2556 * the list to point to the default rule, and then freeing
2557 * the old list without the need for a lock.
2561 free_chain(&layer3_chain, 0 /* keep default rule */);
2566 rule = (struct ip_fw *)rule_buf; /* XXX do a malloc */
2567 error = sooptcopyin(sopt, rule, sizeof(rule_buf),
2568 sizeof(struct ip_fw) );
2569 size = sopt->sopt_valsize;
2570 if (error || (error = check_ipfw_struct(rule, size)))
2573 error = add_rule(&layer3_chain, rule);
2574 size = RULESIZE(rule);
2575 if (!error && sopt->sopt_dir == SOPT_GET)
2576 error = sooptcopyout(sopt, rule, size);
2581 * IP_FW_DEL is used for deleting single rules or sets,
2582 * and (ab)used to atomically manipulate sets. Argument size
2583 * is used to distinguish between the two:
2585 * delete single rule or set of rules,
2586 * or reassign rules (or sets) to a different set.
2587 * 2*sizeof(u_int32_t)
2588 * atomic disable/enable sets.
2589 * first u_int32_t contains sets to be disabled,
2590 * second u_int32_t contains sets to be enabled.
2592 error = sooptcopyin(sopt, rule_buf,
2593 2*sizeof(u_int32_t), sizeof(u_int32_t));
2596 size = sopt->sopt_valsize;
2597 if (size == sizeof(u_int32_t)) /* delete or reassign */
2598 error = del_entry(&layer3_chain, rule_buf[0]);
2599 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */
2601 (set_disable | rule_buf[0]) & ~rule_buf[1] &
2602 ~(1<<31); /* set 31 always enabled */
2608 case IP_FW_RESETLOG: /* argument is an int, the rule number */
2611 if (sopt->sopt_val != 0) {
2612 error = sooptcopyin(sopt, &rulenum,
2613 sizeof(int), sizeof(int));
2617 error = zero_entry(rulenum, sopt->sopt_name == IP_FW_RESETLOG);
2621 printf("ipfw_ctl invalid option %d\n", sopt->sopt_name);
2629 * dummynet needs a reference to the default rule, because rules can be
2630 * deleted while packets hold a reference to them. When this happens,
2631 * dummynet changes the reference to the default rule (it could well be a
2632 * NULL pointer, but this way we do not need to check for the special
2633 * case, plus here he have info on the default behaviour).
2635 struct ip_fw *ip_fw_default_rule;
2638 * This procedure is only used to handle keepalives. It is invoked
2639 * every dyn_keepalive_period
2642 ipfw_tick(void * __unused unused)
2647 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0)
2651 for (i = 0 ; i < curr_dyn_buckets ; i++) {
2652 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) {
2653 if (q->dyn_type == O_LIMIT_PARENT)
2655 if (q->id.proto != IPPROTO_TCP)
2657 if ( (q->state & BOTH_SYN) != BOTH_SYN)
2659 if (TIME_LEQ( time_second+dyn_keepalive_interval,
2661 continue; /* too early */
2662 if (TIME_LEQ(q->expire, time_second))
2663 continue; /* too late, rule expired */
2665 send_pkt(&(q->id), q->ack_rev - 1, q->ack_fwd, TH_SYN);
2666 send_pkt(&(q->id), q->ack_fwd - 1, q->ack_rev, 0);
2671 callout_reset(&ipfw_timeout_h, dyn_keepalive_period * hz,
2678 struct ip_fw default_rule;
2680 ip_fw_chk_ptr = ipfw_chk;
2681 ip_fw_ctl_ptr = ipfw_ctl;
2682 layer3_chain = NULL;
2684 bzero(&default_rule, sizeof default_rule);
2686 default_rule.act_ofs = 0;
2687 default_rule.rulenum = IPFW_DEFAULT_RULE;
2688 default_rule.cmd_len = 1;
2689 default_rule.set = 31;
2691 default_rule.cmd[0].len = 1;
2692 default_rule.cmd[0].opcode =
2693 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
2698 add_rule(&layer3_chain, &default_rule);
2700 ip_fw_default_rule = layer3_chain;
2701 printf("ipfw2 initialized, divert %s, "
2702 "rule-based forwarding enabled, default to %s, logging ",
2708 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny");
2710 #ifdef IPFIREWALL_VERBOSE
2713 #ifdef IPFIREWALL_VERBOSE_LIMIT
2714 verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2716 if (fw_verbose == 0)
2717 printf("disabled\n");
2718 else if (verbose_limit == 0)
2719 printf("unlimited\n");
2721 printf("limited to %d packets/entry by default\n",
2723 callout_init(&ipfw_timeout_h);
2724 callout_reset(&ipfw_timeout_h, hz, ipfw_tick, NULL);
2728 ipfw_modevent(module_t mod, int type, void *unused)
2737 printf("IP firewall already loaded\n");
2746 #if !defined(KLD_MODULE)
2747 printf("ipfw statically compiled, cannot unload\n");
2751 callout_stop(&ipfw_timeout_h);
2752 ip_fw_chk_ptr = NULL;
2753 ip_fw_ctl_ptr = NULL;
2754 free_chain(&layer3_chain, 1 /* kill default rule */);
2756 printf("IP firewall unloaded\n");
2765 static moduledata_t ipfwmod = {
2770 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2771 MODULE_VERSION(ipfw, 1);