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 1.65 2008/08/03 03:26:22 sephe Exp $
33 * Implement IP packet firewall (new version)
39 #include "opt_ipdivert.h"
42 #error IPFIREWALL requires INET.
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/malloc.h>
50 #include <sys/kernel.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/syslog.h>
56 #include <sys/thread2.h>
57 #include <sys/ucred.h>
58 #include <sys/in_cksum.h>
61 #include <net/route.h>
62 #include <net/netmsg2.h>
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/in_var.h>
67 #include <netinet/in_pcb.h>
68 #include <netinet/ip.h>
69 #include <netinet/ip_var.h>
70 #include <netinet/ip_icmp.h>
72 #include <net/dummynet/ip_dummynet.h>
73 #include <netinet/tcp.h>
74 #include <netinet/tcp_timer.h>
75 #include <netinet/tcp_var.h>
76 #include <netinet/tcpip.h>
77 #include <netinet/udp.h>
78 #include <netinet/udp_var.h>
80 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
82 #define IPFW_AUTOINC_STEP_MIN 1
83 #define IPFW_AUTOINC_STEP_MAX 1000
84 #define IPFW_AUTOINC_STEP_DEF 100
87 * set_disable contains one bit per set value (0..31).
88 * If the bit is set, all rules with the corresponding set
89 * are disabled. Set 31 is reserved for the default rule
90 * and CANNOT be disabled.
92 static uint32_t set_disable;
94 static int fw_verbose;
95 static int verbose_limit;
98 static int ipfw_refcnt;
101 static struct callout ipfw_timeout_h;
102 #define IPFW_DEFAULT_RULE 65535
105 * list of rules for layer 3
107 static struct ip_fw *layer3_chain;
109 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
111 static int fw_debug = 1;
112 static int autoinc_step = IPFW_AUTOINC_STEP_DEF;
115 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
116 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_RW,
117 &fw_enable, 0, "Enable ipfw");
118 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW,
119 &autoinc_step, 0, "Rule number autincrement step");
120 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
122 "Only do a single pass through ipfw when using dummynet(4)");
123 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
124 &fw_debug, 0, "Enable printing of debug ip_fw statements");
125 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
126 &fw_verbose, 0, "Log matches to ipfw rules");
127 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
128 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
131 * Description of dynamic rules.
133 * Dynamic rules are stored in lists accessed through a hash table
134 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
135 * be modified through the sysctl variable dyn_buckets which is
136 * updated when the table becomes empty.
138 * XXX currently there is only one list, ipfw_dyn.
140 * When a packet is received, its address fields are first masked
141 * with the mask defined for the rule, then hashed, then matched
142 * against the entries in the corresponding list.
143 * Dynamic rules can be used for different purposes:
145 * + enforcing limits on the number of sessions;
146 * + in-kernel NAT (not implemented yet)
148 * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
149 * measured in seconds and depending on the flags.
151 * The total number of dynamic rules is stored in dyn_count.
152 * The max number of dynamic rules is dyn_max. When we reach
153 * the maximum number of rules we do not create anymore. This is
154 * done to avoid consuming too much memory, but also too much
155 * time when searching on each packet (ideally, we should try instead
156 * to put a limit on the length of the list on each bucket...).
158 * Each dynamic rule holds a pointer to the parent ipfw rule so
159 * we know what action to perform. Dynamic rules are removed when
160 * the parent rule is deleted. XXX we should make them survive.
162 * There are some limitations with dynamic rules -- we do not
163 * obey the 'randomized match', and we do not do multiple
164 * passes through the firewall. XXX check the latter!!!
166 static ipfw_dyn_rule **ipfw_dyn_v = NULL;
167 static uint32_t dyn_buckets = 256; /* must be power of 2 */
168 static uint32_t curr_dyn_buckets = 256; /* must be power of 2 */
169 static uint32_t dyn_buckets_gen; /* generation of dyn buckets array */
172 * Timeouts for various events in handing dynamic rules.
174 static uint32_t dyn_ack_lifetime = 300;
175 static uint32_t dyn_syn_lifetime = 20;
176 static uint32_t dyn_fin_lifetime = 1;
177 static uint32_t dyn_rst_lifetime = 1;
178 static uint32_t dyn_udp_lifetime = 10;
179 static uint32_t dyn_short_lifetime = 5;
182 * Keepalives are sent if dyn_keepalive is set. They are sent every
183 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
184 * seconds of lifetime of a rule.
185 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
186 * than dyn_keepalive_period.
189 static uint32_t dyn_keepalive_interval = 20;
190 static uint32_t dyn_keepalive_period = 5;
191 static uint32_t dyn_keepalive = 1; /* do send keepalives */
193 static uint32_t static_count; /* # of static rules */
194 static uint32_t static_ioc_len; /* bytes of static rules */
195 static uint32_t dyn_count; /* # of dynamic rules */
196 static uint32_t dyn_max = 4096; /* max # of dynamic rules */
198 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
199 &dyn_buckets, 0, "Number of dyn. buckets");
200 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
201 &curr_dyn_buckets, 0, "Current Number of dyn. buckets");
202 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
203 &dyn_count, 0, "Number of dyn. rules");
204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
205 &dyn_max, 0, "Max number of dyn. rules");
206 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
207 &static_count, 0, "Number of static rules");
208 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
209 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
210 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
211 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
212 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
213 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
214 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
215 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
216 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
217 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
218 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
219 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
220 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
221 &dyn_keepalive, 0, "Enable keepalives for dyn. rules");
223 #endif /* SYSCTL_NODE */
225 static struct ip_fw *ip_fw_default_rule;
227 static ip_fw_chk_t ipfw_chk;
230 ipfw_free_rule(struct ip_fw *rule)
232 KASSERT(rule->refcnt > 0, ("invalid refcnt %u\n", rule->refcnt));
233 atomic_subtract_int(&rule->refcnt, 1);
234 if (atomic_cmpset_int(&rule->refcnt, 0, 1)) {
242 ipfw_unref_rule(void *priv)
244 ipfw_free_rule(priv);
246 atomic_subtract_int(&ipfw_refcnt, 1);
251 ipfw_ref_rule(struct ip_fw *rule)
254 atomic_add_int(&ipfw_refcnt, 1);
256 atomic_add_int(&rule->refcnt, 1);
260 * This macro maps an ip pointer into a layer3 header pointer of type T
262 #define L3HDR(T, ip) ((T *)((uint32_t *)(ip) + (ip)->ip_hl))
265 icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd)
267 int type = L3HDR(struct icmp,ip)->icmp_type;
269 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1 << type)));
272 #define TT ((1 << ICMP_ECHO) | \
273 (1 << ICMP_ROUTERSOLICIT) | \
274 (1 << ICMP_TSTAMP) | \
279 is_icmp_query(struct ip *ip)
281 int type = L3HDR(struct icmp, ip)->icmp_type;
283 return (type <= ICMP_MAXTYPE && (TT & (1 << type)));
289 * The following checks use two arrays of 8 or 16 bits to store the
290 * bits that we want set or clear, respectively. They are in the
291 * low and high half of cmd->arg1 or cmd->d[0].
293 * We scan options and store the bits we find set. We succeed if
295 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
297 * The code is sometimes optimized not to store additional variables.
301 flags_match(ipfw_insn *cmd, uint8_t bits)
306 if (((cmd->arg1 & 0xff) & bits) != 0)
307 return 0; /* some bits we want set were clear */
309 want_clear = (cmd->arg1 >> 8) & 0xff;
310 if ((want_clear & bits) != want_clear)
311 return 0; /* some bits we want clear were set */
316 ipopts_match(struct ip *ip, ipfw_insn *cmd)
318 int optlen, bits = 0;
319 u_char *cp = (u_char *)(ip + 1);
320 int x = (ip->ip_hl << 2) - sizeof(struct ip);
322 for (; x > 0; x -= optlen, cp += optlen) {
323 int opt = cp[IPOPT_OPTVAL];
325 if (opt == IPOPT_EOL)
328 if (opt == IPOPT_NOP) {
331 optlen = cp[IPOPT_OLEN];
332 if (optlen <= 0 || optlen > x)
333 return 0; /* invalid or truncated */
338 bits |= IP_FW_IPOPT_LSRR;
342 bits |= IP_FW_IPOPT_SSRR;
346 bits |= IP_FW_IPOPT_RR;
350 bits |= IP_FW_IPOPT_TS;
357 return (flags_match(cmd, bits));
361 tcpopts_match(struct ip *ip, ipfw_insn *cmd)
363 int optlen, bits = 0;
364 struct tcphdr *tcp = L3HDR(struct tcphdr,ip);
365 u_char *cp = (u_char *)(tcp + 1);
366 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
368 for (; x > 0; x -= optlen, cp += optlen) {
371 if (opt == TCPOPT_EOL)
374 if (opt == TCPOPT_NOP) {
384 bits |= IP_FW_TCPOPT_MSS;
388 bits |= IP_FW_TCPOPT_WINDOW;
391 case TCPOPT_SACK_PERMITTED:
393 bits |= IP_FW_TCPOPT_SACK;
396 case TCPOPT_TIMESTAMP:
397 bits |= IP_FW_TCPOPT_TS;
403 bits |= IP_FW_TCPOPT_CC;
410 return (flags_match(cmd, bits));
414 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
416 if (ifp == NULL) /* no iface with this packet, match fails */
419 /* Check by name or by IP address */
420 if (cmd->name[0] != '\0') { /* match by name */
423 if (kfnmatch(cmd->name, ifp->if_xname, 0) == 0)
426 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
430 struct ifaddr_container *ifac;
432 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
433 struct ifaddr *ia = ifac->ifa;
435 if (ia->ifa_addr == NULL)
437 if (ia->ifa_addr->sa_family != AF_INET)
439 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
440 (ia->ifa_addr))->sin_addr.s_addr)
441 return(1); /* match */
444 return(0); /* no match, fail ... */
447 static uint64_t norule_counter; /* counter for ipfw_log(NULL...) */
449 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
452 * We enter here when we have a rule with O_LOG.
453 * XXX this function alone takes about 2Kbytes of code!
456 ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh,
457 struct mbuf *m, struct ifnet *oif)
460 int limit_reached = 0;
461 char action2[40], proto[48], fragment[28];
466 if (f == NULL) { /* bogus pkt */
467 if (verbose_limit != 0 && norule_counter >= verbose_limit)
470 if (norule_counter == verbose_limit)
471 limit_reached = verbose_limit;
473 } else { /* O_LOG is the first action, find the real one */
474 ipfw_insn *cmd = ACTION_PTR(f);
475 ipfw_insn_log *l = (ipfw_insn_log *)cmd;
477 if (l->max_log != 0 && l->log_left == 0)
480 if (l->log_left == 0)
481 limit_reached = l->max_log;
482 cmd += F_LEN(cmd); /* point to first action */
483 if (cmd->opcode == O_PROB)
487 switch (cmd->opcode) {
493 if (cmd->arg1==ICMP_REJECT_RST) {
495 } else if (cmd->arg1==ICMP_UNREACH_HOST) {
498 ksnprintf(SNPARGS(action2, 0), "Unreach %d",
512 ksnprintf(SNPARGS(action2, 0), "Divert %d", cmd->arg1);
516 ksnprintf(SNPARGS(action2, 0), "Tee %d", cmd->arg1);
520 ksnprintf(SNPARGS(action2, 0), "SkipTo %d", cmd->arg1);
524 ksnprintf(SNPARGS(action2, 0), "Pipe %d", cmd->arg1);
528 ksnprintf(SNPARGS(action2, 0), "Queue %d", cmd->arg1);
533 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
536 len = ksnprintf(SNPARGS(action2, 0),
538 inet_ntoa(sa->sa.sin_addr));
539 if (sa->sa.sin_port) {
540 ksnprintf(SNPARGS(action2, len), ":%d",
552 if (hlen == 0) { /* non-ip */
553 ksnprintf(SNPARGS(proto, 0), "MAC");
555 struct ip *ip = mtod(m, struct ip *);
556 /* these three are all aliases to the same thing */
557 struct icmp *const icmp = L3HDR(struct icmp, ip);
558 struct tcphdr *const tcp = (struct tcphdr *)icmp;
559 struct udphdr *const udp = (struct udphdr *)icmp;
561 int ip_off, offset, ip_len;
564 if (eh != NULL) { /* layer 2 packets are as on the wire */
565 ip_off = ntohs(ip->ip_off);
566 ip_len = ntohs(ip->ip_len);
571 offset = ip_off & IP_OFFMASK;
574 len = ksnprintf(SNPARGS(proto, 0), "TCP %s",
575 inet_ntoa(ip->ip_src));
577 ksnprintf(SNPARGS(proto, len), ":%d %s:%d",
578 ntohs(tcp->th_sport),
579 inet_ntoa(ip->ip_dst),
580 ntohs(tcp->th_dport));
582 ksnprintf(SNPARGS(proto, len), " %s",
583 inet_ntoa(ip->ip_dst));
588 len = ksnprintf(SNPARGS(proto, 0), "UDP %s",
589 inet_ntoa(ip->ip_src));
591 ksnprintf(SNPARGS(proto, len), ":%d %s:%d",
592 ntohs(udp->uh_sport),
593 inet_ntoa(ip->ip_dst),
594 ntohs(udp->uh_dport));
596 ksnprintf(SNPARGS(proto, len), " %s",
597 inet_ntoa(ip->ip_dst));
603 len = ksnprintf(SNPARGS(proto, 0),
608 len = ksnprintf(SNPARGS(proto, 0), "ICMP ");
610 len += ksnprintf(SNPARGS(proto, len), "%s",
611 inet_ntoa(ip->ip_src));
612 ksnprintf(SNPARGS(proto, len), " %s",
613 inet_ntoa(ip->ip_dst));
617 len = ksnprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
618 inet_ntoa(ip->ip_src));
619 ksnprintf(SNPARGS(proto, len), " %s",
620 inet_ntoa(ip->ip_dst));
624 if (ip_off & (IP_MF | IP_OFFMASK)) {
625 ksnprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)",
626 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
627 offset << 3, (ip_off & IP_MF) ? "+" : "");
631 if (oif || m->m_pkthdr.rcvif) {
632 log(LOG_SECURITY | LOG_INFO,
633 "ipfw: %d %s %s %s via %s%s\n",
635 action, proto, oif ? "out" : "in",
636 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
639 log(LOG_SECURITY | LOG_INFO,
640 "ipfw: %d %s %s [no if info]%s\n",
642 action, proto, fragment);
646 log(LOG_SECURITY | LOG_NOTICE,
647 "ipfw: limit %d reached on entry %d\n",
648 limit_reached, f ? f->rulenum : -1);
655 * IMPORTANT: the hash function for dynamic rules must be commutative
656 * in source and destination (ip,port), because rules are bidirectional
657 * and we want to find both in the same bucket.
660 hash_packet(struct ipfw_flow_id *id)
664 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
665 i &= (curr_dyn_buckets - 1);
670 * unlink a dynamic rule from a chain. prev is a pointer to
671 * the previous one, q is a pointer to the rule to delete,
672 * head is a pointer to the head of the queue.
673 * Modifies q and potentially also head.
675 #define UNLINK_DYN_RULE(prev, head, q) \
677 ipfw_dyn_rule *old_q = q; \
679 /* remove a refcount to the parent */ \
680 if (q->dyn_type == O_LIMIT) \
681 q->parent->count--; \
682 DEB(kprintf("-- unlink entry 0x%08x %d -> 0x%08x %d, %d left\n", \
683 (q->id.src_ip), (q->id.src_port), \
684 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \
686 prev->next = q = q->next; \
688 head = q = q->next; \
689 KASSERT(dyn_count > 0, ("invalid dyn count %u\n", dyn_count)); \
691 kfree(old_q, M_IPFW); \
694 #define TIME_LEQ(a, b) ((int)((a) - (b)) <= 0)
697 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
699 * If keep_me == NULL, rules are deleted even if not expired,
700 * otherwise only expired rules are removed.
702 * The value of the second parameter is also used to point to identify
703 * a rule we absolutely do not want to remove (e.g. because we are
704 * holding a reference to it -- this is the case with O_LIMIT_PARENT
705 * rules). The pointer is only used for comparison, so any non-null
709 remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
711 static uint32_t last_remove = 0;
713 #define FORCE (keep_me == NULL)
715 ipfw_dyn_rule *prev, *q;
716 int i, pass = 0, max_pass = 0, unlinked = 0;
718 if (ipfw_dyn_v == NULL || dyn_count == 0)
720 /* do not expire more than once per second, it is useless */
721 if (!FORCE && last_remove == time_second)
723 last_remove = time_second;
726 * because O_LIMIT refer to parent rules, during the first pass only
727 * remove child and mark any pending LIMIT_PARENT, and remove
728 * them in a second pass.
731 for (i = 0; i < curr_dyn_buckets; i++) {
732 for (prev = NULL, q = ipfw_dyn_v[i]; q;) {
734 * Logic can become complex here, so we split tests.
738 if (rule != NULL && rule != q->rule)
739 goto next; /* not the one we are looking for */
740 if (q->dyn_type == O_LIMIT_PARENT) {
742 * handle parent in the second pass,
743 * record we need one.
748 if (FORCE && q->count != 0) {
749 /* XXX should not happen! */
750 kprintf("OUCH! cannot remove rule, "
751 "count %d\n", q->count);
754 if (!FORCE && !TIME_LEQ(q->expire, time_second))
758 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
765 if (pass++ < max_pass)
776 * lookup a dynamic rule.
778 static ipfw_dyn_rule *
779 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
783 * stateful ipfw extensions.
784 * Lookup into dynamic session queue
786 #define MATCH_REVERSE 0
787 #define MATCH_FORWARD 1
789 #define MATCH_UNKNOWN 3
790 int i, dir = MATCH_NONE, changed = 0;
791 ipfw_dyn_rule *prev, *q=NULL;
793 if (ipfw_dyn_v == NULL)
794 goto done; /* not found */
796 i = hash_packet(pkt);
797 for (prev = NULL, q = ipfw_dyn_v[i]; q != NULL;) {
798 if (q->dyn_type == O_LIMIT_PARENT)
801 if (TIME_LEQ( q->expire, time_second)) { /* expire entry */
803 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
806 if (pkt->proto == q->id.proto) {
807 if (pkt->src_ip == q->id.src_ip &&
808 pkt->dst_ip == q->id.dst_ip &&
809 pkt->src_port == q->id.src_port &&
810 pkt->dst_port == q->id.dst_port) {
814 if (pkt->src_ip == q->id.dst_ip &&
815 pkt->dst_ip == q->id.src_ip &&
816 pkt->src_port == q->id.dst_port &&
817 pkt->dst_port == q->id.src_port) {
827 goto done; /* q = NULL, not found */
829 if (prev != NULL) { /* found and not in front */
830 prev->next = q->next;
831 q->next = ipfw_dyn_v[i];
836 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
837 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
839 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
840 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
842 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
844 case TH_SYN: /* opening */
845 q->expire = time_second + dyn_syn_lifetime;
848 case BOTH_SYN: /* move to established */
849 case BOTH_SYN | TH_FIN : /* one side tries to close */
850 case BOTH_SYN | (TH_FIN << 8) :
852 uint32_t ack = ntohl(tcp->th_ack);
854 #define _SEQ_GE(a, b) ((int)(a) - (int)(b) >= 0)
856 if (dir == MATCH_FORWARD) {
857 if (q->ack_fwd == 0 ||
858 _SEQ_GE(ack, q->ack_fwd))
860 else /* ignore out-of-sequence */
863 if (q->ack_rev == 0 ||
864 _SEQ_GE(ack, q->ack_rev))
866 else /* ignore out-of-sequence */
871 q->expire = time_second + dyn_ack_lifetime;
874 case BOTH_SYN | BOTH_FIN: /* both sides closed */
875 if (dyn_fin_lifetime >= dyn_keepalive_period)
876 dyn_fin_lifetime = dyn_keepalive_period - 1;
877 q->expire = time_second + dyn_fin_lifetime;
883 * reset or some invalid combination, but can also
884 * occur if we use keep-state the wrong way.
886 if ((q->state & ((TH_RST << 8) | TH_RST)) == 0)
887 kprintf("invalid state: 0x%x\n", q->state);
889 if (dyn_rst_lifetime >= dyn_keepalive_period)
890 dyn_rst_lifetime = dyn_keepalive_period - 1;
891 q->expire = time_second + dyn_rst_lifetime;
894 } else if (pkt->proto == IPPROTO_UDP) {
895 q->expire = time_second + dyn_udp_lifetime;
897 /* other protocols */
898 q->expire = time_second + dyn_short_lifetime;
904 *match_direction = dir;
909 realloc_dynamic_table(void)
911 ipfw_dyn_rule **old_dyn_v;
912 uint32_t old_curr_dyn_buckets;
915 * Try reallocation, make sure we have a power of 2 and do
916 * not allow more than 64k entries. In case of overflow,
919 if (dyn_buckets > 65536)
921 if ((dyn_buckets & (dyn_buckets - 1)) != 0) {
923 * Not a power of 2; reset
925 dyn_buckets = curr_dyn_buckets;
926 if (ipfw_dyn_v != NULL)
930 /* Save the current buckets array for later error recovery */
931 old_dyn_v = ipfw_dyn_v;
932 old_curr_dyn_buckets = curr_dyn_buckets;
934 curr_dyn_buckets = dyn_buckets;
936 ipfw_dyn_v = kmalloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
937 M_IPFW, M_NOWAIT | M_ZERO);
938 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
941 curr_dyn_buckets /= 2;
942 if (curr_dyn_buckets <= old_curr_dyn_buckets &&
945 * Don't try allocating smaller buckets array, reuse
946 * the old one, which alreay contains enough buckets
952 if (ipfw_dyn_v != NULL) {
953 if (old_dyn_v != NULL)
954 kfree(old_dyn_v, M_IPFW);
956 /* Allocation failed, restore old buckets array */
957 ipfw_dyn_v = old_dyn_v;
958 curr_dyn_buckets = old_curr_dyn_buckets;
961 if (ipfw_dyn_v != NULL)
966 * Install state of type 'type' for a dynamic session.
967 * The hash table contains two type of rules:
968 * - regular rules (O_KEEP_STATE)
969 * - rules for sessions with limited number of sess per user
970 * (O_LIMIT). When they are created, the parent is
971 * increased by 1, and decreased on delete. In this case,
972 * the third parameter is the parent rule and not the chain.
973 * - "parent" rules for the above (O_LIMIT_PARENT).
975 static ipfw_dyn_rule *
976 add_dyn_rule(struct ipfw_flow_id *id, uint8_t dyn_type, struct ip_fw *rule)
981 if (ipfw_dyn_v == NULL ||
982 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
983 realloc_dynamic_table();
984 if (ipfw_dyn_v == NULL)
985 return NULL; /* failed ! */
989 r = kmalloc(sizeof(*r), M_IPFW, M_NOWAIT | M_ZERO);
991 kprintf ("sorry cannot allocate state\n");
995 /* increase refcount on parent, and set pointer */
996 if (dyn_type == O_LIMIT) {
997 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
999 if (parent->dyn_type != O_LIMIT_PARENT)
1000 panic("invalid parent");
1003 rule = parent->rule;
1007 r->expire = time_second + dyn_syn_lifetime;
1009 r->dyn_type = dyn_type;
1010 r->pcnt = r->bcnt = 0;
1014 r->next = ipfw_dyn_v[i];
1018 DEB(kprintf("-- add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
1020 (r->id.src_ip), (r->id.src_port),
1021 (r->id.dst_ip), (r->id.dst_port),
1027 * lookup dynamic parent rule using pkt and rule as search keys.
1028 * If the lookup fails, then install one.
1030 static ipfw_dyn_rule *
1031 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
1037 i = hash_packet(pkt);
1038 for (q = ipfw_dyn_v[i]; q != NULL; q = q->next) {
1039 if (q->dyn_type == O_LIMIT_PARENT &&
1041 pkt->proto == q->id.proto &&
1042 pkt->src_ip == q->id.src_ip &&
1043 pkt->dst_ip == q->id.dst_ip &&
1044 pkt->src_port == q->id.src_port &&
1045 pkt->dst_port == q->id.dst_port) {
1046 q->expire = time_second + dyn_short_lifetime;
1047 DEB(kprintf("lookup_dyn_parent found 0x%p\n",q);)
1052 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
1056 * Install dynamic state for rule type cmd->o.opcode
1058 * Returns 1 (failure) if state is not installed because of errors or because
1059 * session limitations are enforced.
1062 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
1063 struct ip_fw_args *args)
1065 static int last_log;
1069 DEB(kprintf("-- install state type %d 0x%08x %u -> 0x%08x %u\n",
1071 (args->f_id.src_ip), (args->f_id.src_port),
1072 (args->f_id.dst_ip), (args->f_id.dst_port) );)
1074 q = lookup_dyn_rule(&args->f_id, NULL, NULL);
1075 if (q != NULL) { /* should never occur */
1076 if (last_log != time_second) {
1077 last_log = time_second;
1078 kprintf(" install_state: entry already present, done\n");
1083 if (dyn_count >= dyn_max) {
1085 * Run out of slots, try to remove any expired rule.
1087 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1);
1090 if (dyn_count >= dyn_max) {
1091 if (last_log != time_second) {
1092 last_log = time_second;
1093 kprintf("install_state: Too many dynamic rules\n");
1095 return 1; /* cannot install, notify caller */
1098 switch (cmd->o.opcode) {
1099 case O_KEEP_STATE: /* bidir rule */
1100 if (add_dyn_rule(&args->f_id, O_KEEP_STATE, rule) == NULL)
1104 case O_LIMIT: /* limit number of sessions */
1106 uint16_t limit_mask = cmd->limit_mask;
1107 struct ipfw_flow_id id;
1108 ipfw_dyn_rule *parent;
1110 DEB(kprintf("installing dyn-limit rule %d\n",
1113 id.dst_ip = id.src_ip = 0;
1114 id.dst_port = id.src_port = 0;
1115 id.proto = args->f_id.proto;
1117 if (limit_mask & DYN_SRC_ADDR)
1118 id.src_ip = args->f_id.src_ip;
1119 if (limit_mask & DYN_DST_ADDR)
1120 id.dst_ip = args->f_id.dst_ip;
1121 if (limit_mask & DYN_SRC_PORT)
1122 id.src_port = args->f_id.src_port;
1123 if (limit_mask & DYN_DST_PORT)
1124 id.dst_port = args->f_id.dst_port;
1126 parent = lookup_dyn_parent(&id, rule);
1127 if (parent == NULL) {
1128 kprintf("add parent failed\n");
1132 if (parent->count >= cmd->conn_limit) {
1134 * See if we can remove some expired rule.
1136 remove_dyn_rule(rule, parent);
1137 if (parent->count >= cmd->conn_limit) {
1139 last_log != time_second) {
1140 last_log = time_second;
1141 log(LOG_SECURITY | LOG_DEBUG,
1143 "too many entries\n");
1148 if (add_dyn_rule(&args->f_id, O_LIMIT,
1149 (struct ip_fw *)parent) == NULL)
1154 kprintf("unknown dynamic rule type %u\n", cmd->o.opcode);
1157 lookup_dyn_rule(&args->f_id, NULL, NULL); /* XXX just set lifetime */
1162 * Transmit a TCP packet, containing either a RST or a keepalive.
1163 * When flags & TH_RST, we are sending a RST packet, because of a
1164 * "reset" action matched the packet.
1165 * Otherwise we are sending a keepalive, and flags & TH_
1168 send_pkt(struct ipfw_flow_id *id, uint32_t seq, uint32_t ack, int flags)
1173 struct route sro; /* fake route */
1175 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1178 m->m_pkthdr.rcvif = NULL;
1179 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
1180 m->m_data += max_linkhdr;
1182 ip = mtod(m, struct ip *);
1183 bzero(ip, m->m_len);
1184 tcp = (struct tcphdr *)(ip + 1); /* no IP options */
1185 ip->ip_p = IPPROTO_TCP;
1189 * Assume we are sending a RST (or a keepalive in the reverse
1190 * direction), swap src and destination addresses and ports.
1192 ip->ip_src.s_addr = htonl(id->dst_ip);
1193 ip->ip_dst.s_addr = htonl(id->src_ip);
1194 tcp->th_sport = htons(id->dst_port);
1195 tcp->th_dport = htons(id->src_port);
1196 if (flags & TH_RST) { /* we are sending a RST */
1197 if (flags & TH_ACK) {
1198 tcp->th_seq = htonl(ack);
1199 tcp->th_ack = htonl(0);
1200 tcp->th_flags = TH_RST;
1204 tcp->th_seq = htonl(0);
1205 tcp->th_ack = htonl(seq);
1206 tcp->th_flags = TH_RST | TH_ACK;
1210 * We are sending a keepalive. flags & TH_SYN determines
1211 * the direction, forward if set, reverse if clear.
1212 * NOTE: seq and ack are always assumed to be correct
1213 * as set by the caller. This may be confusing...
1215 if (flags & TH_SYN) {
1217 * we have to rewrite the correct addresses!
1219 ip->ip_dst.s_addr = htonl(id->dst_ip);
1220 ip->ip_src.s_addr = htonl(id->src_ip);
1221 tcp->th_dport = htons(id->dst_port);
1222 tcp->th_sport = htons(id->src_port);
1224 tcp->th_seq = htonl(seq);
1225 tcp->th_ack = htonl(ack);
1226 tcp->th_flags = TH_ACK;
1230 * set ip_len to the payload size so we can compute
1231 * the tcp checksum on the pseudoheader
1232 * XXX check this, could save a couple of words ?
1234 ip->ip_len = htons(sizeof(struct tcphdr));
1235 tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
1238 * now fill fields left out earlier
1240 ip->ip_ttl = ip_defttl;
1241 ip->ip_len = m->m_pkthdr.len;
1243 bzero(&sro, sizeof(sro));
1244 ip_rtaddr(ip->ip_dst, &sro);
1246 m->m_pkthdr.fw_flags |= IPFW_MBUF_GENERATED;
1247 ip_output(m, NULL, &sro, 0, NULL, NULL);
1253 * sends a reject message, consuming the mbuf passed as an argument.
1256 send_reject(struct ip_fw_args *args, int code, int offset, int ip_len)
1258 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
1259 /* We need the IP header in host order for icmp_error(). */
1260 if (args->eh != NULL) {
1261 struct ip *ip = mtod(args->m, struct ip *);
1263 ip->ip_len = ntohs(ip->ip_len);
1264 ip->ip_off = ntohs(ip->ip_off);
1266 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
1267 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
1268 struct tcphdr *const tcp =
1269 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
1271 if ((tcp->th_flags & TH_RST) == 0) {
1272 send_pkt(&args->f_id, ntohl(tcp->th_seq),
1273 ntohl(tcp->th_ack), tcp->th_flags | TH_RST);
1284 * Given an ip_fw *, lookup_next_rule will return a pointer
1285 * to the next rule, which can be either the jump
1286 * target (for skipto instructions) or the next one in the list (in
1287 * all other cases including a missing jump target).
1288 * The result is also written in the "next_rule" field of the rule.
1289 * Backward jumps are not allowed, so start looking from the next
1292 * This never returns NULL -- in case we do not have an exact match,
1293 * the next rule is returned. When the ruleset is changed,
1294 * pointers are flushed so we are always correct.
1297 static struct ip_fw *
1298 lookup_next_rule(struct ip_fw *me)
1300 struct ip_fw *rule = NULL;
1303 /* look for action, in case it is a skipto */
1304 cmd = ACTION_PTR(me);
1305 if (cmd->opcode == O_LOG)
1307 if (cmd->opcode == O_SKIPTO) {
1308 for (rule = me->next; rule; rule = rule->next) {
1309 if (rule->rulenum >= cmd->arg1)
1313 if (rule == NULL) /* failure or not a skipto */
1315 me->next_rule = rule;
1320 * The main check routine for the firewall.
1322 * All arguments are in args so we can modify them and return them
1323 * back to the caller.
1327 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
1328 * Starts with the IP header.
1329 * args->eh (in) Mac header if present, or NULL for layer3 packet.
1330 * args->oif Outgoing interface, or NULL if packet is incoming.
1331 * The incoming interface is in the mbuf. (in)
1333 * args->rule Pointer to the last matching rule (in/out)
1334 * args->next_hop Socket we are forwarding to (out).
1335 * args->f_id Addresses grabbed from the packet (out)
1339 * IP_FW_PORT_DENY_FLAG the packet must be dropped.
1340 * 0 The packet is to be accepted and routed normally OR
1341 * the packet was denied/rejected and has been dropped;
1342 * in the latter case, *m is equal to NULL upon return.
1343 * port Divert the packet to port, with these caveats:
1345 * - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead
1346 * of diverting it (ie, 'ipfw tee').
1348 * - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower
1349 * 16 bits as a dummynet pipe number instead of diverting
1353 ipfw_chk(struct ip_fw_args *args)
1356 * Local variables hold state during the processing of a packet.
1358 * IMPORTANT NOTE: to speed up the processing of rules, there
1359 * are some assumption on the values of the variables, which
1360 * are documented here. Should you change them, please check
1361 * the implementation of the various instructions to make sure
1362 * that they still work.
1364 * args->eh The MAC header. It is non-null for a layer2
1365 * packet, it is NULL for a layer-3 packet.
1367 * m | args->m Pointer to the mbuf, as received from the caller.
1368 * It may change if ipfw_chk() does an m_pullup, or if it
1369 * consumes the packet because it calls send_reject().
1370 * XXX This has to change, so that ipfw_chk() never modifies
1371 * or consumes the buffer.
1372 * ip is simply an alias of the value of m, and it is kept
1373 * in sync with it (the packet is supposed to start with
1376 struct mbuf *m = args->m;
1377 struct ip *ip = mtod(m, struct ip *);
1380 * oif | args->oif If NULL, ipfw_chk has been called on the
1381 * inbound path (ether_input, ip_input).
1382 * If non-NULL, ipfw_chk has been called on the outbound path
1383 * (ether_output, ip_output).
1385 struct ifnet *oif = args->oif;
1387 struct ip_fw *f = NULL; /* matching rule */
1392 * hlen The length of the IPv4 header.
1393 * hlen >0 means we have an IPv4 packet.
1395 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
1398 * offset The offset of a fragment. offset != 0 means that
1399 * we have a fragment at this offset of an IPv4 packet.
1400 * offset == 0 means that (if this is an IPv4 packet)
1401 * this is the first or only fragment.
1406 * Local copies of addresses. They are only valid if we have
1409 * proto The protocol. Set to 0 for non-ip packets,
1410 * or to the protocol read from the packet otherwise.
1411 * proto != 0 means that we have an IPv4 packet.
1413 * src_port, dst_port port numbers, in HOST format. Only
1414 * valid for TCP and UDP packets.
1416 * src_ip, dst_ip ip addresses, in NETWORK format.
1417 * Only valid for IPv4 packets.
1420 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */
1421 struct in_addr src_ip, dst_ip; /* NOTE: network format */
1422 uint16_t ip_len = 0;
1423 int dyn_dir = MATCH_UNKNOWN;
1424 ipfw_dyn_rule *q = NULL;
1426 if (m->m_pkthdr.fw_flags & IPFW_MBUF_GENERATED)
1427 return 0; /* accept */
1429 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
1430 * MATCH_NONE when checked and not matched (q = NULL),
1431 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
1434 if (args->eh == NULL || /* layer 3 packet */
1435 (m->m_pkthdr.len >= sizeof(struct ip) &&
1436 ntohs(args->eh->ether_type) == ETHERTYPE_IP))
1437 hlen = ip->ip_hl << 2;
1440 * Collect parameters into local variables for faster matching.
1442 if (hlen == 0) { /* do not grab addresses for non-ip pkts */
1443 proto = args->f_id.proto = 0; /* mark f_id invalid */
1444 goto after_ip_checks;
1447 proto = args->f_id.proto = ip->ip_p;
1448 src_ip = ip->ip_src;
1449 dst_ip = ip->ip_dst;
1450 if (args->eh != NULL) { /* layer 2 packets are as on the wire */
1451 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1452 ip_len = ntohs(ip->ip_len);
1454 offset = ip->ip_off & IP_OFFMASK;
1455 ip_len = ip->ip_len;
1458 #define PULLUP_TO(len) \
1460 if (m->m_len < (len)) { \
1461 args->m = m = m_pullup(m, (len));\
1463 goto pullup_failed; \
1464 ip = mtod(m, struct ip *); \
1474 PULLUP_TO(hlen + sizeof(struct tcphdr));
1475 tcp = L3HDR(struct tcphdr, ip);
1476 dst_port = tcp->th_dport;
1477 src_port = tcp->th_sport;
1478 args->f_id.flags = tcp->th_flags;
1486 PULLUP_TO(hlen + sizeof(struct udphdr));
1487 udp = L3HDR(struct udphdr, ip);
1488 dst_port = udp->uh_dport;
1489 src_port = udp->uh_sport;
1494 PULLUP_TO(hlen + 4); /* type, code and checksum. */
1495 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type;
1505 args->f_id.src_ip = ntohl(src_ip.s_addr);
1506 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1507 args->f_id.src_port = src_port = ntohs(src_port);
1508 args->f_id.dst_port = dst_port = ntohs(dst_port);
1513 * Packet has already been tagged. Look for the next rule
1514 * to restart processing.
1516 * If fw_one_pass != 0 then just accept it.
1517 * XXX should not happen here, but optimized out in
1523 /* This rule was deleted */
1524 if (args->rule->rule_flags & IPFW_RULE_F_INVALID)
1525 return IP_FW_PORT_DENY_FLAG;
1527 f = args->rule->next_rule;
1529 f = lookup_next_rule(args->rule);
1532 * Find the starting rule. It can be either the first
1533 * one, or the one after divert_rule if asked so.
1537 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
1539 skipto = *(uint16_t *)m_tag_data(mtag);
1544 if (args->eh == NULL && skipto != 0) {
1545 if (skipto >= IPFW_DEFAULT_RULE)
1546 return(IP_FW_PORT_DENY_FLAG); /* invalid */
1547 while (f && f->rulenum <= skipto)
1549 if (f == NULL) /* drop packet */
1550 return(IP_FW_PORT_DENY_FLAG);
1553 if ((mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL)
1554 m_tag_delete(m, mtag);
1557 * Now scan the rules, and parse microinstructions for each rule.
1559 for (; f; f = f->next) {
1562 int skip_or; /* skip rest of OR block */
1565 if (set_disable & (1 << f->set))
1569 for (l = f->cmd_len, cmd = f->cmd; l > 0;
1570 l -= cmdlen, cmd += cmdlen) {
1574 * check_body is a jump target used when we find a
1575 * CHECK_STATE, and need to jump to the body of
1580 cmdlen = F_LEN(cmd);
1582 * An OR block (insn_1 || .. || insn_n) has the
1583 * F_OR bit set in all but the last instruction.
1584 * The first match will set "skip_or", and cause
1585 * the following instructions to be skipped until
1586 * past the one with the F_OR bit clear.
1588 if (skip_or) { /* skip this instruction */
1589 if ((cmd->len & F_OR) == 0)
1590 skip_or = 0; /* next one is good */
1593 match = 0; /* set to 1 if we succeed */
1595 switch (cmd->opcode) {
1597 * The first set of opcodes compares the packet's
1598 * fields with some pattern, setting 'match' if a
1599 * match is found. At the end of the loop there is
1600 * logic to deal with F_NOT and F_OR flags associated
1608 kprintf("ipfw: opcode %d unimplemented\n",
1615 * We only check offset == 0 && proto != 0,
1616 * as this ensures that we have an IPv4
1617 * packet with the ports info.
1622 struct inpcbinfo *pi;
1626 if (proto == IPPROTO_TCP) {
1628 pi = &tcbinfo[mycpu->gd_cpuid];
1629 } else if (proto == IPPROTO_UDP) {
1636 in_pcblookup_hash(pi,
1637 dst_ip, htons(dst_port),
1638 src_ip, htons(src_port),
1640 in_pcblookup_hash(pi,
1641 src_ip, htons(src_port),
1642 dst_ip, htons(dst_port),
1645 if (pcb == NULL || pcb->inp_socket == NULL)
1648 if (cmd->opcode == O_UID) {
1649 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b))
1651 !socheckuid(pcb->inp_socket,
1652 (uid_t)((ipfw_insn_u32 *)cmd)->d[0]);
1655 match = groupmember(
1656 (uid_t)((ipfw_insn_u32 *)cmd)->d[0],
1657 pcb->inp_socket->so_cred);
1663 match = iface_match(m->m_pkthdr.rcvif,
1664 (ipfw_insn_if *)cmd);
1668 match = iface_match(oif, (ipfw_insn_if *)cmd);
1672 match = iface_match(oif ? oif :
1673 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1677 if (args->eh != NULL) { /* have MAC header */
1678 uint32_t *want = (uint32_t *)
1679 ((ipfw_insn_mac *)cmd)->addr;
1680 uint32_t *mask = (uint32_t *)
1681 ((ipfw_insn_mac *)cmd)->mask;
1682 uint32_t *hdr = (uint32_t *)args->eh;
1685 (want[0] == (hdr[0] & mask[0]) &&
1686 want[1] == (hdr[1] & mask[1]) &&
1687 want[2] == (hdr[2] & mask[2]));
1692 if (args->eh != NULL) {
1694 ntohs(args->eh->ether_type);
1696 ((ipfw_insn_u16 *)cmd)->ports;
1699 /* Special vlan handling */
1700 if (m->m_flags & M_VLANTAG)
1703 for (i = cmdlen - 1; !match && i > 0;
1706 (t >= p[0] && t <= p[1]);
1712 match = (hlen > 0 && offset != 0);
1715 case O_IN: /* "out" is "not in" */
1716 match = (oif == NULL);
1720 match = (args->eh != NULL);
1725 * We do not allow an arg of 0 so the
1726 * check of "proto" only suffices.
1728 match = (proto == cmd->arg1);
1732 match = (hlen > 0 &&
1733 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1738 match = (hlen > 0 &&
1739 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1741 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1748 tif = INADDR_TO_IFP(&src_ip);
1749 match = (tif != NULL);
1756 uint32_t *d = (uint32_t *)(cmd + 1);
1758 cmd->opcode == O_IP_DST_SET ?
1764 addr -= d[0]; /* subtract base */
1766 (addr < cmd->arg1) &&
1767 (d[1 + (addr >> 5)] &
1768 (1 << (addr & 0x1f)));
1773 match = (hlen > 0 &&
1774 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
1779 match = (hlen > 0) &&
1780 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1782 ((ipfw_insn_ip *)cmd)->mask.s_addr));
1789 tif = INADDR_TO_IFP(&dst_ip);
1790 match = (tif != NULL);
1797 * offset == 0 && proto != 0 is enough
1798 * to guarantee that we have an IPv4
1799 * packet with port info.
1801 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1804 (cmd->opcode == O_IP_SRCPORT) ?
1805 src_port : dst_port ;
1807 ((ipfw_insn_u16 *)cmd)->ports;
1810 for (i = cmdlen - 1; !match && i > 0;
1813 (x >= p[0] && x <= p[1]);
1819 match = (offset == 0 && proto==IPPROTO_ICMP &&
1820 icmptype_match(ip, (ipfw_insn_u32 *)cmd));
1824 match = (hlen > 0 && ipopts_match(ip, cmd));
1828 match = (hlen > 0 && cmd->arg1 == ip->ip_v);
1832 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl);
1836 match = (hlen > 0 &&
1837 cmd->arg1 == ntohs(ip->ip_id));
1841 match = (hlen > 0 && cmd->arg1 == ip_len);
1844 case O_IPPRECEDENCE:
1845 match = (hlen > 0 &&
1846 (cmd->arg1 == (ip->ip_tos & 0xe0)));
1850 match = (hlen > 0 &&
1851 flags_match(cmd, ip->ip_tos));
1855 match = (proto == IPPROTO_TCP && offset == 0 &&
1857 L3HDR(struct tcphdr,ip)->th_flags));
1861 match = (proto == IPPROTO_TCP && offset == 0 &&
1862 tcpopts_match(ip, cmd));
1866 match = (proto == IPPROTO_TCP && offset == 0 &&
1867 ((ipfw_insn_u32 *)cmd)->d[0] ==
1868 L3HDR(struct tcphdr,ip)->th_seq);
1872 match = (proto == IPPROTO_TCP && offset == 0 &&
1873 ((ipfw_insn_u32 *)cmd)->d[0] ==
1874 L3HDR(struct tcphdr,ip)->th_ack);
1878 match = (proto == IPPROTO_TCP && offset == 0 &&
1880 L3HDR(struct tcphdr,ip)->th_win);
1884 /* reject packets which have SYN only */
1885 /* XXX should i also check for TH_ACK ? */
1886 match = (proto == IPPROTO_TCP && offset == 0 &&
1887 (L3HDR(struct tcphdr,ip)->th_flags &
1888 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1893 ipfw_log(f, hlen, args->eh, m, oif);
1898 match = (krandom() <
1899 ((ipfw_insn_u32 *)cmd)->d[0]);
1903 * The second set of opcodes represents 'actions',
1904 * i.e. the terminal part of a rule once the packet
1905 * matches all previous patterns.
1906 * Typically there is only one action for each rule,
1907 * and the opcode is stored at the end of the rule
1908 * (but there are exceptions -- see below).
1910 * In general, here we set retval and terminate the
1911 * outer loop (would be a 'break 3' in some language,
1912 * but we need to do a 'goto done').
1915 * O_COUNT and O_SKIPTO actions:
1916 * instead of terminating, we jump to the next rule
1917 * ('goto next_rule', equivalent to a 'break 2'),
1918 * or to the SKIPTO target ('goto again' after
1919 * having set f, cmd and l), respectively.
1921 * O_LIMIT and O_KEEP_STATE: these opcodes are
1922 * not real 'actions', and are stored right
1923 * before the 'action' part of the rule.
1924 * These opcodes try to install an entry in the
1925 * state tables; if successful, we continue with
1926 * the next opcode (match=1; break;), otherwise
1927 * the packet * must be dropped
1928 * ('goto done' after setting retval);
1930 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1931 * cause a lookup of the state table, and a jump
1932 * to the 'action' part of the parent rule
1933 * ('goto check_body') if an entry is found, or
1934 * (CHECK_STATE only) a jump to the next rule if
1935 * the entry is not found ('goto next_rule').
1936 * The result of the lookup is cached to make
1937 * further instances of these opcodes are
1942 if (install_state(f,
1943 (ipfw_insn_limit *)cmd, args)) {
1944 retval = IP_FW_PORT_DENY_FLAG;
1945 goto done; /* error/limit violation */
1953 * dynamic rules are checked at the first
1954 * keep-state or check-state occurrence,
1955 * with the result being stored in dyn_dir.
1956 * The compiler introduces a PROBE_STATE
1957 * instruction for us when we have a
1958 * KEEP_STATE (because PROBE_STATE needs
1961 if (dyn_dir == MATCH_UNKNOWN &&
1962 (q = lookup_dyn_rule(&args->f_id,
1963 &dyn_dir, proto == IPPROTO_TCP ?
1964 L3HDR(struct tcphdr, ip) : NULL))
1967 * Found dynamic entry, update stats
1968 * and jump to the 'action' part of
1974 cmd = ACTION_PTR(f);
1975 l = f->cmd_len - f->act_ofs;
1979 * Dynamic entry not found. If CHECK_STATE,
1980 * skip to next rule, if PROBE_STATE just
1981 * ignore and continue with next opcode.
1983 if (cmd->opcode == O_CHECK_STATE)
1989 retval = 0; /* accept */
1994 args->rule = f; /* report matching rule */
1995 retval = cmd->arg1 | IP_FW_PORT_DYNT_FLAG;
2000 if (args->eh) /* not on layer 2 */
2003 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT,
2004 sizeof(uint16_t), MB_DONTWAIT);
2006 retval = IP_FW_PORT_DENY_FLAG;
2009 *(uint16_t *)m_tag_data(mtag) = f->rulenum;
2010 m_tag_prepend(m, mtag);
2011 retval = (cmd->opcode == O_DIVERT) ?
2013 cmd->arg1 | IP_FW_PORT_TEE_FLAG;
2018 f->pcnt++; /* update stats */
2020 f->timestamp = time_second;
2021 if (cmd->opcode == O_COUNT)
2024 if (f->next_rule == NULL)
2025 lookup_next_rule(f);
2031 * Drop the packet and send a reject notice
2032 * if the packet is not ICMP (or is an ICMP
2033 * query), and it is not multicast/broadcast.
2036 (proto != IPPROTO_ICMP ||
2037 is_icmp_query(ip)) &&
2038 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2039 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2040 send_reject(args, cmd->arg1,
2046 retval = IP_FW_PORT_DENY_FLAG;
2050 if (args->eh) /* not valid on layer2 pkts */
2052 if (!q || dyn_dir == MATCH_FORWARD) {
2054 &((ipfw_insn_sa *)cmd)->sa;
2060 panic("-- unknown opcode %d\n", cmd->opcode);
2061 } /* end of switch() on opcodes */
2063 if (cmd->len & F_NOT)
2067 if (cmd->len & F_OR)
2070 if (!(cmd->len & F_OR)) /* not an OR block, */
2071 break; /* try next rule */
2074 } /* end of inner for, scan opcodes */
2076 next_rule:; /* try next rule */
2078 } /* end of outer for, scan rules */
2079 kprintf("+++ ipfw: ouch!, skip past end of rules, denying packet\n");
2080 return(IP_FW_PORT_DENY_FLAG);
2083 /* Update statistics */
2086 f->timestamp = time_second;
2091 kprintf("pullup failed\n");
2092 return(IP_FW_PORT_DENY_FLAG);
2096 ipfw_dummynet_io(struct mbuf *m, int pipe_nr, int dir, struct ip_fw_args *fwa)
2101 const struct ipfw_flow_id *id;
2102 struct dn_flow_id *fid;
2106 mtag = m_tag_get(PACKET_TAG_DUMMYNET, sizeof(*pkt), MB_DONTWAIT);
2111 m_tag_prepend(m, mtag);
2113 pkt = m_tag_data(mtag);
2114 bzero(pkt, sizeof(*pkt));
2116 cmd = fwa->rule->cmd + fwa->rule->act_ofs;
2117 if (cmd->opcode == O_LOG)
2119 KASSERT(cmd->opcode == O_PIPE || cmd->opcode == O_QUEUE,
2120 ("Rule is not PIPE or QUEUE, opcode %d\n", cmd->opcode));
2123 pkt->dn_flags = (dir & DN_FLAGS_DIR_MASK);
2124 pkt->ifp = fwa->oif;
2125 pkt->cpuid = mycpu->gd_cpuid;
2126 pkt->pipe_nr = pipe_nr;
2130 fid->fid_dst_ip = id->dst_ip;
2131 fid->fid_src_ip = id->src_ip;
2132 fid->fid_dst_port = id->dst_port;
2133 fid->fid_src_port = id->src_port;
2134 fid->fid_proto = id->proto;
2135 fid->fid_flags = id->flags;
2137 ipfw_ref_rule(fwa->rule);
2138 pkt->dn_priv = fwa->rule;
2139 pkt->dn_unref_priv = ipfw_unref_rule;
2141 if (cmd->opcode == O_PIPE)
2142 pkt->dn_flags |= DN_FLAGS_IS_PIPE;
2144 if (dir == DN_TO_IP_OUT) {
2146 * We need to copy *ro because for ICMP pkts (and maybe
2147 * others) the caller passed a pointer into the stack;
2148 * dst might also be a pointer into *ro so it needs to
2151 pkt->ro = *(fwa->ro);
2153 fwa->ro->ro_rt->rt_refcnt++;
2154 if (fwa->dst == (struct sockaddr_in *)&fwa->ro->ro_dst) {
2155 /* 'dst' points into 'ro' */
2156 fwa->dst = (struct sockaddr_in *)&(pkt->ro.ro_dst);
2158 pkt->dn_dst = fwa->dst;
2159 pkt->flags = fwa->flags;
2162 m->m_pkthdr.fw_flags |= DUMMYNET_MBUF_TAGGED;
2167 * When a rule is added/deleted, clear the next_rule pointers in all rules.
2168 * These will be reconstructed on the fly as packets are matched.
2169 * Must be called at splimp().
2172 flush_rule_ptrs(void)
2176 for (rule = layer3_chain; rule; rule = rule->next)
2177 rule->next_rule = NULL;
2180 static __inline void
2181 ipfw_inc_static_count(struct ip_fw *rule)
2183 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
2186 static_ioc_len += IOC_RULESIZE(rule);
2189 static __inline void
2190 ipfw_dec_static_count(struct ip_fw *rule)
2192 int l = IOC_RULESIZE(rule);
2194 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
2196 KASSERT(static_count > 0, ("invalid static count %u\n", static_count));
2199 KASSERT(static_ioc_len >= l,
2200 ("invalid static len %u\n", static_ioc_len));
2201 static_ioc_len -= l;
2204 static struct ip_fw *
2205 ipfw_create_rule(const struct ipfw_ioc_rule *ioc_rule)
2209 rule = kmalloc(RULESIZE(ioc_rule), M_IPFW, M_WAITOK | M_ZERO);
2211 rule->act_ofs = ioc_rule->act_ofs;
2212 rule->cmd_len = ioc_rule->cmd_len;
2213 rule->rulenum = ioc_rule->rulenum;
2214 rule->set = ioc_rule->set;
2215 rule->usr_flags = ioc_rule->usr_flags;
2217 bcopy(ioc_rule->cmd, rule->cmd, rule->cmd_len * 4 /* XXX */);
2225 * Add a new rule to the list. Copy the rule into a malloc'ed area,
2226 * then possibly create a rule number and add the rule to the list.
2227 * Update the rule_number in the input struct so the caller knows
2231 ipfw_add_rule(struct ip_fw **head, struct ipfw_ioc_rule *ioc_rule)
2233 struct ip_fw *rule, *f, *prev;
2235 KKASSERT(*head != NULL);
2236 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
2238 rule = ipfw_create_rule(ioc_rule);
2243 * If rulenum is 0, find highest numbered rule before the
2244 * default rule, and add rule number incremental step
2246 if (rule->rulenum == 0) {
2247 int step = autoinc_step;
2250 * Make sure that rule number incremental step
2253 if (step < IPFW_AUTOINC_STEP_MIN)
2254 step = IPFW_AUTOINC_STEP_MIN;
2255 else if (step > IPFW_AUTOINC_STEP_MAX)
2256 step = IPFW_AUTOINC_STEP_MAX;
2259 * Locate the highest numbered rule before default
2261 for (f = *head; f; f = f->next) {
2262 if (f->rulenum == IPFW_DEFAULT_RULE)
2264 rule->rulenum = f->rulenum;
2266 if (rule->rulenum < IPFW_DEFAULT_RULE - step)
2267 rule->rulenum += step;
2269 /* Update the input structure */
2270 ioc_rule->rulenum = rule->rulenum;
2274 * Now insert the new rule in the right place in the sorted list.
2276 for (prev = NULL, f = *head; f; prev = f, f = f->next) {
2277 if (f->rulenum > rule->rulenum) {
2278 /* Found the location */
2291 ipfw_inc_static_count(rule);
2295 DEB(kprintf("++ installed rule %d, static count now %d\n",
2296 rule->rulenum, static_count);)
2300 * Free storage associated with a static rule (including derived
2302 * The caller is in charge of clearing rule pointers to avoid
2303 * dangling pointers.
2304 * @return a pointer to the next entry.
2305 * Arguments are not checked, so they better be correct.
2306 * Must be called at splimp().
2308 static struct ip_fw *
2309 delete_rule(struct ip_fw **head, struct ip_fw *prev, struct ip_fw *rule)
2314 remove_dyn_rule(rule, NULL /* force removal */);
2319 ipfw_dec_static_count(rule);
2321 /* Mark the rule as invalid */
2322 rule->rule_flags |= IPFW_RULE_F_INVALID;
2323 rule->next_rule = NULL;
2325 /* Try to free this rule */
2326 ipfw_free_rule(rule);
2332 * Deletes all rules from a chain (including the default rule
2333 * if the second argument is set).
2334 * Must be called at splimp().
2337 free_chain(struct ip_fw **chain, int kill_default)
2341 flush_rule_ptrs(); /* more efficient to do outside the loop */
2343 while ((rule = *chain) != NULL &&
2344 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE))
2345 delete_rule(chain, NULL, rule);
2347 KASSERT(dyn_count == 0, ("%u dyn rule remains\n", dyn_count));
2350 ip_fw_default_rule = NULL; /* Reset default rule */
2352 if (ipfw_dyn_v != NULL) {
2354 * Free dynamic rules(state) hash table
2356 kfree(ipfw_dyn_v, M_IPFW);
2360 KASSERT(static_count == 0,
2361 ("%u static rules remains\n", static_count));
2362 KASSERT(static_ioc_len == 0,
2363 ("%u bytes of static rules remains\n", static_ioc_len));
2365 KASSERT(static_count == 1,
2366 ("%u static rules remains\n", static_count));
2367 KASSERT(static_ioc_len == IOC_RULESIZE(ip_fw_default_rule),
2368 ("%u bytes of static rules remains, should be %u\n",
2369 static_ioc_len, IOC_RULESIZE(ip_fw_default_rule)));
2374 * Remove all rules with given number, and also do set manipulation.
2376 * The argument is an uint32_t. The low 16 bit are the rule or set number,
2377 * the next 8 bits are the new set, the top 8 bits are the command:
2379 * 0 delete rules with given number
2380 * 1 delete rules with given set number
2381 * 2 move rules with given number to new set
2382 * 3 move rules with given set number to new set
2383 * 4 swap sets with given numbers
2386 del_entry(struct ip_fw **chain, uint32_t arg)
2388 struct ip_fw *prev, *rule;
2390 uint8_t cmd, new_set;
2392 rulenum = arg & 0xffff;
2393 cmd = (arg >> 24) & 0xff;
2394 new_set = (arg >> 16) & 0xff;
2400 if (cmd == 0 || cmd == 2) {
2401 if (rulenum == IPFW_DEFAULT_RULE)
2409 case 0: /* delete rules with given number */
2411 * locate first rule to delete
2413 for (prev = NULL, rule = *chain;
2414 rule && rule->rulenum < rulenum;
2415 prev = rule, rule = rule->next)
2417 if (rule->rulenum != rulenum)
2420 crit_enter(); /* no access to rules while removing */
2422 * flush pointers outside the loop, then delete all matching
2423 * rules. prev remains the same throughout the cycle.
2426 while (rule && rule->rulenum == rulenum)
2427 rule = delete_rule(chain, prev, rule);
2431 case 1: /* delete all rules with given set number */
2434 for (prev = NULL, rule = *chain; rule;) {
2435 if (rule->set == rulenum) {
2436 rule = delete_rule(chain, prev, rule);
2445 case 2: /* move rules with given number to new set */
2447 for (rule = *chain; rule; rule = rule->next) {
2448 if (rule->rulenum == rulenum)
2449 rule->set = new_set;
2454 case 3: /* move rules with given set number to new set */
2456 for (rule = *chain; rule; rule = rule->next) {
2457 if (rule->set == rulenum)
2458 rule->set = new_set;
2463 case 4: /* swap two sets */
2465 for (rule = *chain; rule; rule = rule->next) {
2466 if (rule->set == rulenum)
2467 rule->set = new_set;
2468 else if (rule->set == new_set)
2469 rule->set = rulenum;
2478 * Clear counters for a specific rule.
2481 clear_counters(struct ip_fw *rule, int log_only)
2483 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
2485 if (log_only == 0) {
2486 rule->bcnt = rule->pcnt = 0;
2487 rule->timestamp = 0;
2489 if (l->o.opcode == O_LOG)
2490 l->log_left = l->max_log;
2494 * Reset some or all counters on firewall rules.
2495 * @arg frwl is null to clear all entries, or contains a specific
2497 * @arg log_only is 1 if we only want to reset logs, zero otherwise.
2500 zero_entry(int rulenum, int log_only)
2508 for (rule = layer3_chain; rule; rule = rule->next)
2509 clear_counters(rule, log_only);
2511 msg = log_only ? "ipfw: All logging counts reset.\n"
2512 : "ipfw: Accounting cleared.\n";
2517 * We can have multiple rules with the same number, so we
2518 * need to clear them all.
2520 for (rule = layer3_chain; rule; rule = rule->next) {
2521 if (rule->rulenum == rulenum) {
2523 while (rule && rule->rulenum == rulenum) {
2524 clear_counters(rule, log_only);
2532 if (!cleared) /* we did not find any matching rules */
2534 msg = log_only ? "ipfw: Entry %d logging count reset.\n"
2535 : "ipfw: Entry %d cleared.\n";
2538 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
2543 * Check validity of the structure before insert.
2544 * Fortunately rules are simple, so this mostly need to check rule sizes.
2547 ipfw_ctl_check_rule(struct ipfw_ioc_rule *rule, int size)
2550 int have_action = 0;
2553 /* Check for valid size */
2554 if (size < sizeof(*rule)) {
2555 kprintf("ipfw: rule too short\n");
2558 l = IOC_RULESIZE(rule);
2560 kprintf("ipfw: size mismatch (have %d want %d)\n", size, l);
2565 * Now go for the individual checks. Very simple ones, basically only
2566 * instruction sizes.
2568 for (l = rule->cmd_len, cmd = rule->cmd; l > 0;
2569 l -= cmdlen, cmd += cmdlen) {
2570 cmdlen = F_LEN(cmd);
2572 kprintf("ipfw: opcode %d size truncated\n",
2576 DEB(kprintf("ipfw: opcode %d\n", cmd->opcode);)
2577 switch (cmd->opcode) {
2591 case O_IPPRECEDENCE:
2598 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2610 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
2615 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
2620 if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
2623 ((ipfw_insn_log *)cmd)->log_left =
2624 ((ipfw_insn_log *)cmd)->max_log;
2630 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip))
2632 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) {
2633 kprintf("ipfw: opcode %d, useless rule\n",
2641 if (cmd->arg1 == 0 || cmd->arg1 > 256) {
2642 kprintf("ipfw: invalid set size %d\n",
2646 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
2652 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
2658 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
2659 if (cmdlen < 2 || cmdlen > 31)
2666 if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
2672 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
2677 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
2681 case O_FORWARD_MAC: /* XXX not implemented yet */
2690 if (cmdlen != F_INSN_SIZE(ipfw_insn))
2694 kprintf("ipfw: opcode %d, multiple actions"
2701 kprintf("ipfw: opcode %d, action must be"
2708 kprintf("ipfw: opcode %d, unknown opcode\n",
2713 if (have_action == 0) {
2714 kprintf("ipfw: missing action\n");
2720 kprintf("ipfw: opcode %d size %d wrong\n",
2721 cmd->opcode, cmdlen);
2726 ipfw_ctl_add_rule(struct sockopt *sopt)
2728 struct ipfw_ioc_rule *ioc_rule;
2732 size = sopt->sopt_valsize;
2733 if (size > (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX) ||
2734 size < sizeof(*ioc_rule)) {
2737 if (size != (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX)) {
2738 sopt->sopt_val = krealloc(sopt->sopt_val, sizeof(uint32_t) *
2739 IPFW_RULE_SIZE_MAX, M_TEMP, M_WAITOK);
2741 ioc_rule = sopt->sopt_val;
2743 error = ipfw_ctl_check_rule(ioc_rule, size);
2747 ipfw_add_rule(&layer3_chain, ioc_rule);
2749 if (sopt->sopt_dir == SOPT_GET)
2750 sopt->sopt_valsize = IOC_RULESIZE(ioc_rule);
2755 ipfw_copy_rule(const struct ip_fw *rule, struct ipfw_ioc_rule *ioc_rule)
2757 ioc_rule->act_ofs = rule->act_ofs;
2758 ioc_rule->cmd_len = rule->cmd_len;
2759 ioc_rule->rulenum = rule->rulenum;
2760 ioc_rule->set = rule->set;
2761 ioc_rule->usr_flags = rule->usr_flags;
2763 ioc_rule->set_disable = set_disable;
2764 ioc_rule->static_count = static_count;
2765 ioc_rule->static_len = static_ioc_len;
2767 ioc_rule->pcnt = rule->pcnt;
2768 ioc_rule->bcnt = rule->bcnt;
2769 ioc_rule->timestamp = rule->timestamp;
2771 bcopy(rule->cmd, ioc_rule->cmd, ioc_rule->cmd_len * 4 /* XXX */);
2773 return ((uint8_t *)ioc_rule + IOC_RULESIZE(ioc_rule));
2777 ipfw_copy_state(const ipfw_dyn_rule *dyn_rule,
2778 struct ipfw_ioc_state *ioc_state)
2780 const struct ipfw_flow_id *id;
2781 struct ipfw_ioc_flowid *ioc_id;
2783 ioc_state->expire = TIME_LEQ(dyn_rule->expire, time_second) ?
2784 0 : dyn_rule->expire - time_second;
2785 ioc_state->pcnt = dyn_rule->pcnt;
2786 ioc_state->bcnt = dyn_rule->bcnt;
2788 ioc_state->dyn_type = dyn_rule->dyn_type;
2789 ioc_state->count = dyn_rule->count;
2791 ioc_state->rulenum = dyn_rule->rule->rulenum;
2794 ioc_id = &ioc_state->id;
2796 ioc_id->type = ETHERTYPE_IP;
2797 ioc_id->u.ip.dst_ip = id->dst_ip;
2798 ioc_id->u.ip.src_ip = id->src_ip;
2799 ioc_id->u.ip.dst_port = id->dst_port;
2800 ioc_id->u.ip.src_port = id->src_port;
2801 ioc_id->u.ip.proto = id->proto;
2805 ipfw_ctl_get_rules(struct sockopt *sopt)
2812 * pass up a copy of the current rules. Static rules
2813 * come first (the last of which has number IPFW_DEFAULT_RULE),
2814 * followed by a possibly empty list of dynamic rule.
2818 size = static_ioc_len; /* size of static rules */
2819 if (ipfw_dyn_v) /* add size of dyn.rules */
2820 size += (dyn_count * sizeof(struct ipfw_ioc_state));
2822 if (sopt->sopt_valsize < size) {
2823 /* short length, no need to return incomplete rules */
2824 /* XXX: if superuser, no need to zero buffer */
2825 bzero(sopt->sopt_val, sopt->sopt_valsize);
2828 bp = sopt->sopt_val;
2830 for (rule = layer3_chain; rule; rule = rule->next)
2831 bp = ipfw_copy_rule(rule, bp);
2834 struct ipfw_ioc_state *ioc_state;
2838 for (i = 0; i < curr_dyn_buckets; i++) {
2841 for (p = ipfw_dyn_v[i]; p != NULL;
2842 p = p->next, ioc_state++)
2843 ipfw_copy_state(p, ioc_state);
2849 sopt->sopt_valsize = size;
2854 * {set|get}sockopt parser.
2857 ipfw_ctl(struct sockopt *sopt)
2865 switch (sopt->sopt_name) {
2867 error = ipfw_ctl_get_rules(sopt);
2872 * Normally we cannot release the lock on each iteration.
2873 * We could do it here only because we start from the head all
2874 * the times so there is no risk of missing some entries.
2875 * On the other hand, the risk is that we end up with
2876 * a very inconsistent ruleset, so better keep the lock
2877 * around the whole cycle.
2879 * XXX this code can be improved by resetting the head of
2880 * the list to point to the default rule, and then freeing
2881 * the old list without the need for a lock.
2885 free_chain(&layer3_chain, 0 /* keep default rule */);
2890 error = ipfw_ctl_add_rule(sopt);
2895 * IP_FW_DEL is used for deleting single rules or sets,
2896 * and (ab)used to atomically manipulate sets. Argument size
2897 * is used to distinguish between the two:
2899 * delete single rule or set of rules,
2900 * or reassign rules (or sets) to a different set.
2901 * 2*sizeof(uint32_t)
2902 * atomic disable/enable sets.
2903 * first uint32_t contains sets to be disabled,
2904 * second uint32_t contains sets to be enabled.
2906 masks = sopt->sopt_val;
2907 size = sopt->sopt_valsize;
2908 if (size == sizeof(*masks)) {
2910 * Delete or reassign static rule
2912 error = del_entry(&layer3_chain, masks[0]);
2913 } else if (size == (2 * sizeof(*masks))) {
2915 * Set enable/disable
2920 (set_disable | masks[0]) & ~masks[1] &
2921 ~(1 << 31); /* set 31 always enabled */
2930 case IP_FW_RESETLOG: /* argument is an int, the rule number */
2933 if (sopt->sopt_val != 0) {
2934 error = soopt_to_kbuf(sopt, &rulenum,
2935 sizeof(int), sizeof(int));
2939 error = zero_entry(rulenum, sopt->sopt_name == IP_FW_RESETLOG);
2943 kprintf("ipfw_ctl invalid option %d\n", sopt->sopt_name);
2950 * This procedure is only used to handle keepalives. It is invoked
2951 * every dyn_keepalive_period
2954 ipfw_tick(void *unused __unused)
2960 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0)
2965 keep_alive = time_second;
2967 gen = dyn_buckets_gen;
2968 for (i = 0; i < curr_dyn_buckets; i++) {
2971 for (q = ipfw_dyn_v[i]; q; q = q->next) {
2972 uint32_t ack_rev, ack_fwd;
2973 struct ipfw_flow_id id;
2975 if (q->dyn_type == O_LIMIT_PARENT)
2977 if (q->id.proto != IPPROTO_TCP)
2979 if ((q->state & BOTH_SYN) != BOTH_SYN)
2981 if (TIME_LEQ(time_second + dyn_keepalive_interval,
2983 continue; /* too early */
2984 if (TIME_LEQ(q->expire, time_second))
2985 continue; /* too late, rule expired */
2986 if (q->keep_alive == keep_alive)
2987 continue; /* alreay done */
2990 * Save necessary information, so that they could
2991 * survive after possible blocking in send_pkt()
2994 ack_rev = q->ack_rev;
2995 ack_fwd = q->ack_fwd;
2997 /* Sending has been started */
2998 q->keep_alive = keep_alive;
3000 send_pkt(&id, ack_rev - 1, ack_fwd, TH_SYN);
3001 send_pkt(&id, ack_fwd - 1, ack_rev, 0);
3003 if (gen != dyn_buckets_gen) {
3005 * Dyn bucket array has been changed during
3006 * the above two sending; reiterate.
3014 callout_reset(&ipfw_timeout_h, dyn_keepalive_period * hz,
3019 ipfw_init_default_rule(struct ip_fw **head)
3021 struct ip_fw *def_rule;
3023 KKASSERT(*head == NULL);
3025 def_rule = kmalloc(sizeof(*def_rule), M_IPFW, M_WAITOK | M_ZERO);
3027 def_rule->act_ofs = 0;
3028 def_rule->rulenum = IPFW_DEFAULT_RULE;
3029 def_rule->cmd_len = 1;
3032 def_rule->cmd[0].len = 1;
3033 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
3034 def_rule->cmd[0].opcode = O_ACCEPT;
3036 def_rule->cmd[0].opcode = O_DENY;
3039 def_rule->refcnt = 1;
3042 ipfw_inc_static_count(def_rule);
3044 /* Install the default rule */
3045 ip_fw_default_rule = def_rule;
3049 ipfw_init_dispatch(struct netmsg *nmsg)
3056 kprintf("IP firewall already loaded\n");
3061 ip_fw_chk_ptr = ipfw_chk;
3062 ip_fw_ctl_ptr = ipfw_ctl;
3063 ip_fw_dn_io_ptr = ipfw_dummynet_io;
3065 layer3_chain = NULL;
3066 ipfw_init_default_rule(&layer3_chain);
3068 kprintf("ipfw2 initialized, divert %s, "
3069 "rule-based forwarding enabled, default to %s, logging ",
3075 ip_fw_default_rule->cmd[0].opcode == O_ACCEPT ?
3078 #ifdef IPFIREWALL_VERBOSE
3081 #ifdef IPFIREWALL_VERBOSE_LIMIT
3082 verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
3084 if (fw_verbose == 0) {
3085 kprintf("disabled\n");
3086 } else if (verbose_limit == 0) {
3087 kprintf("unlimited\n");
3089 kprintf("limited to %d packets/entry by default\n",
3092 callout_init(&ipfw_timeout_h);
3095 callout_reset(&ipfw_timeout_h, hz, ipfw_tick, NULL);
3098 lwkt_replymsg(&nmsg->nm_lmsg, error);
3106 netmsg_init(&smsg, &curthread->td_msgport, 0, ipfw_init_dispatch);
3107 return lwkt_domsg(IPFW_CFGPORT, &smsg.nm_lmsg, 0);
3113 ipfw_fini_dispatch(struct netmsg *nmsg)
3119 if (ipfw_refcnt != 0) {
3124 callout_stop(&ipfw_timeout_h);
3127 netmsg_service_sync();
3129 ip_fw_chk_ptr = NULL;
3130 ip_fw_ctl_ptr = NULL;
3131 ip_fw_dn_io_ptr = NULL;
3132 free_chain(&layer3_chain, 1 /* kill default rule */);
3134 kprintf("IP firewall unloaded\n");
3137 lwkt_replymsg(&nmsg->nm_lmsg, error);
3145 netmsg_init(&smsg, &curthread->td_msgport, 0, ipfw_fini_dispatch);
3146 return lwkt_domsg(IPFW_CFGPORT, &smsg.nm_lmsg, 0);
3149 #endif /* KLD_MODULE */
3152 ipfw_modevent(module_t mod, int type, void *unused)
3163 kprintf("ipfw statically compiled, cannot unload\n");
3175 static moduledata_t ipfwmod = {
3180 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_END, SI_ORDER_ANY);
3181 MODULE_VERSION(ipfw, 1);