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
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
33 * Dynamic rule support for ipfw
39 #error IPFIREWALL requires INET.
41 #include "opt_inet6.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/malloc.h>
47 #include <sys/kernel.h>
50 #include <sys/rmlock.h>
51 #include <sys/socket.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <net/ethernet.h> /* for ETHERTYPE_IP */
56 #include <net/if_var.h>
60 #include <netinet/in.h>
61 #include <netinet/ip.h>
62 #include <netinet/ip_var.h> /* ip_defttl */
63 #include <netinet/ip_fw.h>
64 #include <netinet/tcp_var.h>
65 #include <netinet/udp.h>
67 #include <netinet/ip6.h> /* IN6_ARE_ADDR_EQUAL */
69 #include <netinet6/in6_var.h>
70 #include <netinet6/ip6_var.h>
73 #include <netpfil/ipfw/ip_fw_private.h>
75 #include <machine/in_cksum.h> /* XXX for in_cksum */
78 #include <security/mac/mac_framework.h>
82 * Description of dynamic rules.
84 * Dynamic rules are stored in lists accessed through a hash table
85 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
86 * be modified through the sysctl variable dyn_buckets which is
87 * updated when the table becomes empty.
89 * XXX currently there is only one list, ipfw_dyn.
91 * When a packet is received, its address fields are first masked
92 * with the mask defined for the rule, then hashed, then matched
93 * against the entries in the corresponding list.
94 * Dynamic rules can be used for different purposes:
96 * + enforcing limits on the number of sessions;
97 * + in-kernel NAT (not implemented yet)
99 * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
100 * measured in seconds and depending on the flags.
102 * The total number of dynamic rules is equal to UMA zone items count.
103 * The max number of dynamic rules is dyn_max. When we reach
104 * the maximum number of rules we do not create anymore. This is
105 * done to avoid consuming too much memory, but also too much
106 * time when searching on each packet (ideally, we should try instead
107 * to put a limit on the length of the list on each bucket...).
109 * Each dynamic rule holds a pointer to the parent ipfw rule so
110 * we know what action to perform. Dynamic rules are removed when
111 * the parent rule is deleted. This can be changed by dyn_keep_states
114 * There are some limitations with dynamic rules -- we do not
115 * obey the 'randomized match', and we do not do multiple
116 * passes through the firewall. XXX check the latter!!!
119 struct ipfw_dyn_bucket {
120 struct mtx mtx; /* Bucket protecting lock */
121 ipfw_dyn_rule *head; /* Pointer to first rule */
125 * Static variables followed by global ones
127 static VNET_DEFINE(struct ipfw_dyn_bucket *, ipfw_dyn_v);
128 static VNET_DEFINE(u_int32_t, dyn_buckets_max);
129 static VNET_DEFINE(u_int32_t, curr_dyn_buckets);
130 static VNET_DEFINE(struct callout, ipfw_timeout);
131 #define V_ipfw_dyn_v VNET(ipfw_dyn_v)
132 #define V_dyn_buckets_max VNET(dyn_buckets_max)
133 #define V_curr_dyn_buckets VNET(curr_dyn_buckets)
134 #define V_ipfw_timeout VNET(ipfw_timeout)
136 static VNET_DEFINE(uma_zone_t, ipfw_dyn_rule_zone);
137 #define V_ipfw_dyn_rule_zone VNET(ipfw_dyn_rule_zone)
139 #define IPFW_BUCK_LOCK_INIT(b) \
140 mtx_init(&(b)->mtx, "IPFW dynamic bucket", NULL, MTX_DEF)
141 #define IPFW_BUCK_LOCK_DESTROY(b) \
142 mtx_destroy(&(b)->mtx)
143 #define IPFW_BUCK_LOCK(i) mtx_lock(&V_ipfw_dyn_v[(i)].mtx)
144 #define IPFW_BUCK_UNLOCK(i) mtx_unlock(&V_ipfw_dyn_v[(i)].mtx)
145 #define IPFW_BUCK_ASSERT(i) mtx_assert(&V_ipfw_dyn_v[(i)].mtx, MA_OWNED)
148 static VNET_DEFINE(int, dyn_keep_states);
149 #define V_dyn_keep_states VNET(dyn_keep_states)
152 * Timeouts for various events in handing dynamic rules.
154 static VNET_DEFINE(u_int32_t, dyn_ack_lifetime);
155 static VNET_DEFINE(u_int32_t, dyn_syn_lifetime);
156 static VNET_DEFINE(u_int32_t, dyn_fin_lifetime);
157 static VNET_DEFINE(u_int32_t, dyn_rst_lifetime);
158 static VNET_DEFINE(u_int32_t, dyn_udp_lifetime);
159 static VNET_DEFINE(u_int32_t, dyn_short_lifetime);
161 #define V_dyn_ack_lifetime VNET(dyn_ack_lifetime)
162 #define V_dyn_syn_lifetime VNET(dyn_syn_lifetime)
163 #define V_dyn_fin_lifetime VNET(dyn_fin_lifetime)
164 #define V_dyn_rst_lifetime VNET(dyn_rst_lifetime)
165 #define V_dyn_udp_lifetime VNET(dyn_udp_lifetime)
166 #define V_dyn_short_lifetime VNET(dyn_short_lifetime)
169 * Keepalives are sent if dyn_keepalive is set. They are sent every
170 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
171 * seconds of lifetime of a rule.
172 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
173 * than dyn_keepalive_period.
176 static VNET_DEFINE(u_int32_t, dyn_keepalive_interval);
177 static VNET_DEFINE(u_int32_t, dyn_keepalive_period);
178 static VNET_DEFINE(u_int32_t, dyn_keepalive);
179 static VNET_DEFINE(time_t, dyn_keepalive_last);
181 #define V_dyn_keepalive_interval VNET(dyn_keepalive_interval)
182 #define V_dyn_keepalive_period VNET(dyn_keepalive_period)
183 #define V_dyn_keepalive VNET(dyn_keepalive)
184 #define V_dyn_keepalive_last VNET(dyn_keepalive_last)
186 static VNET_DEFINE(u_int32_t, dyn_max); /* max # of dynamic rules */
188 #define DYN_COUNT uma_zone_get_cur(V_ipfw_dyn_rule_zone)
189 #define V_dyn_max VNET(dyn_max)
191 /* for userspace, we emulate the uma_zone_counter with ipfw_dyn_count */
192 static int ipfw_dyn_count; /* number of objects */
194 #ifdef USERSPACE /* emulation of UMA object counters for userspace */
195 #define uma_zone_get_cur(x) ipfw_dyn_count
196 #endif /* USERSPACE */
198 static int last_log; /* Log ratelimiting */
200 static void ipfw_dyn_tick(void *vnetx);
201 static void check_dyn_rules(struct ip_fw_chain *, ipfw_range_tlv *, int, int);
204 static int sysctl_ipfw_dyn_count(SYSCTL_HANDLER_ARGS);
205 static int sysctl_ipfw_dyn_max(SYSCTL_HANDLER_ARGS);
209 SYSCTL_DECL(_net_inet_ip_fw);
210 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_buckets,
211 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_buckets_max), 0,
212 "Max number of dyn. buckets");
213 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets,
214 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0,
215 "Current Number of dyn. buckets");
216 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_count,
217 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RD, 0, 0, sysctl_ipfw_dyn_count, "IU",
218 "Number of dyn. rules");
219 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max,
220 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_dyn_max, "IU",
221 "Max number of dyn. rules");
222 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime,
223 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0,
224 "Lifetime of dyn. rules for acks");
225 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime,
226 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0,
227 "Lifetime of dyn. rules for syn");
228 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime,
229 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0,
230 "Lifetime of dyn. rules for fin");
231 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime,
232 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0,
233 "Lifetime of dyn. rules for rst");
234 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime,
235 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0,
236 "Lifetime of dyn. rules for UDP");
237 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime,
238 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0,
239 "Lifetime of dyn. rules for other situations");
240 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive,
241 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0,
242 "Enable keepalives for dyn. rules");
243 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, dyn_keep_states,
244 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0,
245 "Do not flush dynamic states on rule deletion");
249 #endif /* SYSCTL_NODE */
254 hash_packet6(struct ipfw_flow_id *id)
257 i = (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^
258 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^
259 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^
260 (id->src_ip6.__u6_addr.__u6_addr32[3]);
266 * IMPORTANT: the hash function for dynamic rules must be commutative
267 * in source and destination (ip,port), because rules are bidirectional
268 * and we want to find both in the same bucket.
271 hash_packet(struct ipfw_flow_id *id, int buckets)
276 if (IS_IP6_FLOW_ID(id))
277 i = hash_packet6(id);
280 i = (id->dst_ip) ^ (id->src_ip);
281 i ^= (id->dst_port) ^ (id->src_port);
282 return (i & (buckets - 1));
286 #define DYN_DEBUG(fmt, ...) do { \
287 printf("%s: " fmt "\n", __func__, __VA_ARGS__); \
290 #define DYN_DEBUG(fmt, ...)
293 static char *default_state_name = "default";
294 struct dyn_state_obj {
295 struct named_object no;
299 #define DYN_STATE_OBJ(ch, cmd) \
300 ((struct dyn_state_obj *)SRV_OBJECT(ch, (cmd)->arg1))
302 * Classifier callback.
303 * Return 0 if opcode contains object that should be referenced
307 dyn_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
310 DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
311 /* Don't rewrite "check-state any" */
312 if (cmd->arg1 == 0 &&
313 cmd->opcode == O_CHECK_STATE)
322 dyn_update(ipfw_insn *cmd, uint16_t idx)
326 DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
330 dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
331 struct named_object **pno)
336 DYN_DEBUG("uidx %d", ti->uidx);
338 if (ti->tlvs == NULL)
340 /* Search ntlv in the buffer provided by user */
341 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
342 IPFW_TLV_STATE_NAME);
347 name = default_state_name;
349 * Search named object with corresponding name.
350 * Since states objects are global - ignore the set value
351 * and use zero instead.
353 *pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0,
354 IPFW_TLV_STATE_NAME, name);
356 * We always return success here.
357 * The caller will check *pno and mark object as unresolved,
358 * then it will automatically create "default" object.
363 static struct named_object *
364 dyn_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
367 DYN_DEBUG("kidx %d", idx);
368 return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx));
372 dyn_create(struct ip_fw_chain *ch, struct tid_info *ti,
375 struct namedobj_instance *ni;
376 struct dyn_state_obj *obj;
377 struct named_object *no;
381 DYN_DEBUG("uidx %d", ti->uidx);
383 if (ti->tlvs == NULL)
385 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
386 IPFW_TLV_STATE_NAME);
391 name = default_state_name;
393 ni = CHAIN_TO_SRV(ch);
394 obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO);
395 obj->no.name = obj->name;
396 obj->no.etlv = IPFW_TLV_STATE_NAME;
397 strlcpy(obj->name, name, sizeof(obj->name));
400 no = ipfw_objhash_lookup_name_type(ni, 0,
401 IPFW_TLV_STATE_NAME, name);
404 * Object is already created.
405 * Just return its kidx and bump refcount.
411 DYN_DEBUG("\tfound kidx %d", *pkidx);
414 if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) {
415 DYN_DEBUG("\talloc_idx failed for %s", name);
420 ipfw_objhash_add(ni, &obj->no);
422 SRV_OBJECT(ch, obj->no.kidx) = obj;
425 *pkidx = obj->no.kidx;
427 DYN_DEBUG("\tcreated kidx %d", *pkidx);
432 dyn_destroy(struct ip_fw_chain *ch, struct named_object *no)
434 struct dyn_state_obj *obj;
436 IPFW_UH_WLOCK_ASSERT(ch);
438 KASSERT(no->refcnt == 1,
439 ("Destroying object '%s' (type %u, idx %u) with refcnt %u",
440 no->name, no->etlv, no->kidx, no->refcnt));
442 DYN_DEBUG("kidx %d", no->kidx);
444 obj = SRV_OBJECT(ch, no->kidx);
445 SRV_OBJECT(ch, no->kidx) = NULL;
447 ipfw_objhash_del(CHAIN_TO_SRV(ch), no);
448 ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx);
453 static struct opcode_obj_rewrite dyn_opcodes[] = {
455 O_KEEP_STATE, IPFW_TLV_STATE_NAME,
456 dyn_classify, dyn_update,
457 dyn_findbyname, dyn_findbykidx,
458 dyn_create, dyn_destroy
461 O_CHECK_STATE, IPFW_TLV_STATE_NAME,
462 dyn_classify, dyn_update,
463 dyn_findbyname, dyn_findbykidx,
464 dyn_create, dyn_destroy
467 O_PROBE_STATE, IPFW_TLV_STATE_NAME,
468 dyn_classify, dyn_update,
469 dyn_findbyname, dyn_findbykidx,
470 dyn_create, dyn_destroy
473 O_LIMIT, IPFW_TLV_STATE_NAME,
474 dyn_classify, dyn_update,
475 dyn_findbyname, dyn_findbykidx,
476 dyn_create, dyn_destroy
480 * Print customizable flow id description via log(9) facility.
483 print_dyn_rule_flags(struct ipfw_flow_id *id, int dyn_type, int log_flags,
484 char *prefix, char *postfix)
488 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
490 char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN];
494 if (IS_IP6_FLOW_ID(id)) {
495 ip6_sprintf(src, &id->src_ip6);
496 ip6_sprintf(dst, &id->dst_ip6);
500 da.s_addr = htonl(id->src_ip);
501 inet_ntop(AF_INET, &da, src, sizeof(src));
502 da.s_addr = htonl(id->dst_ip);
503 inet_ntop(AF_INET, &da, dst, sizeof(dst));
505 log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n",
506 prefix, dyn_type, src, id->src_port, dst,
507 id->dst_port, DYN_COUNT, postfix);
510 #define print_dyn_rule(id, dtype, prefix, postfix) \
511 print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix)
513 #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
514 #define TIME_LE(a,b) ((int)((a)-(b)) < 0)
517 dyn_update_proto_state(ipfw_dyn_rule *q, const struct ipfw_flow_id *id,
518 const struct tcphdr *tcp, int dir)
523 if (id->proto == IPPROTO_TCP) {
524 flags = id->_flags & (TH_FIN | TH_SYN | TH_RST);
525 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
526 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
527 #define TCP_FLAGS (TH_FLAGS | (TH_FLAGS << 8))
528 #define ACK_FWD 0x10000 /* fwd ack seen */
529 #define ACK_REV 0x20000 /* rev ack seen */
531 q->state |= (dir == MATCH_FORWARD) ? flags : (flags << 8);
532 switch (q->state & TCP_FLAGS) {
533 case TH_SYN: /* opening */
534 q->expire = time_uptime + V_dyn_syn_lifetime;
537 case BOTH_SYN: /* move to established */
538 case BOTH_SYN | TH_FIN: /* one side tries to close */
539 case BOTH_SYN | (TH_FIN << 8):
540 #define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0)
544 ack = ntohl(tcp->th_ack);
545 if (dir == MATCH_FORWARD) {
546 if (q->ack_fwd == 0 ||
547 _SEQ_GE(ack, q->ack_fwd)) {
552 if (q->ack_rev == 0 ||
553 _SEQ_GE(ack, q->ack_rev)) {
558 if ((q->state & (ACK_FWD | ACK_REV)) ==
559 (ACK_FWD | ACK_REV)) {
560 q->expire = time_uptime + V_dyn_ack_lifetime;
561 q->state &= ~(ACK_FWD | ACK_REV);
565 case BOTH_SYN | BOTH_FIN: /* both sides closed */
566 if (V_dyn_fin_lifetime >= V_dyn_keepalive_period)
568 V_dyn_keepalive_period - 1;
569 q->expire = time_uptime + V_dyn_fin_lifetime;
575 * reset or some invalid combination, but can also
576 * occur if we use keep-state the wrong way.
578 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
579 printf("invalid state: 0x%x\n", q->state);
581 if (V_dyn_rst_lifetime >= V_dyn_keepalive_period)
583 V_dyn_keepalive_period - 1;
584 q->expire = time_uptime + V_dyn_rst_lifetime;
587 } else if (id->proto == IPPROTO_UDP) {
588 q->expire = time_uptime + V_dyn_udp_lifetime;
590 /* other protocols */
591 q->expire = time_uptime + V_dyn_short_lifetime;
596 * Lookup a dynamic rule, locked version.
598 static ipfw_dyn_rule *
599 lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int i, int *match_direction,
600 struct tcphdr *tcp, uint16_t kidx)
603 * Stateful ipfw extensions.
604 * Lookup into dynamic session queue.
606 ipfw_dyn_rule *prev, *q = NULL;
612 for (prev = NULL, q = V_ipfw_dyn_v[i].head; q; prev = q, q = q->next) {
613 if (q->dyn_type == O_LIMIT_PARENT)
616 if (pkt->proto != q->id.proto)
619 if (kidx != 0 && kidx != q->kidx)
622 if (IS_IP6_FLOW_ID(pkt)) {
623 if (IN6_ARE_ADDR_EQUAL(&pkt->src_ip6, &q->id.src_ip6) &&
624 IN6_ARE_ADDR_EQUAL(&pkt->dst_ip6, &q->id.dst_ip6) &&
625 pkt->src_port == q->id.src_port &&
626 pkt->dst_port == q->id.dst_port) {
630 if (IN6_ARE_ADDR_EQUAL(&pkt->src_ip6, &q->id.dst_ip6) &&
631 IN6_ARE_ADDR_EQUAL(&pkt->dst_ip6, &q->id.src_ip6) &&
632 pkt->src_port == q->id.dst_port &&
633 pkt->dst_port == q->id.src_port) {
638 if (pkt->src_ip == q->id.src_ip &&
639 pkt->dst_ip == q->id.dst_ip &&
640 pkt->src_port == q->id.src_port &&
641 pkt->dst_port == q->id.dst_port) {
645 if (pkt->src_ip == q->id.dst_ip &&
646 pkt->dst_ip == q->id.src_ip &&
647 pkt->src_port == q->id.dst_port &&
648 pkt->dst_port == q->id.src_port) {
655 goto done; /* q = NULL, not found */
657 if (prev != NULL) { /* found and not in front */
658 prev->next = q->next;
659 q->next = V_ipfw_dyn_v[i].head;
660 V_ipfw_dyn_v[i].head = q;
663 /* update state according to flags */
664 dyn_update_proto_state(q, pkt, tcp, dir);
666 if (match_direction != NULL)
667 *match_direction = dir;
672 ipfw_lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
673 struct tcphdr *tcp, uint16_t kidx)
678 i = hash_packet(pkt, V_curr_dyn_buckets);
681 q = lookup_dyn_rule_locked(pkt, i, match_direction, tcp, kidx);
684 /* NB: return table locked when q is not NULL */
690 * @p - pointer to dynamic rule
693 ipfw_dyn_unlock(ipfw_dyn_rule *q)
696 IPFW_BUCK_UNLOCK(q->bucket);
700 resize_dynamic_table(struct ip_fw_chain *chain, int nbuckets)
702 int i, k, nbuckets_old;
704 struct ipfw_dyn_bucket *dyn_v, *dyn_v_old;
706 /* Check if given number is power of 2 and less than 64k */
707 if ((nbuckets > 65536) || (!powerof2(nbuckets)))
710 CTR3(KTR_NET, "%s: resize dynamic hash: %d -> %d", __func__,
711 V_curr_dyn_buckets, nbuckets);
713 /* Allocate and initialize new hash */
714 dyn_v = malloc(nbuckets * sizeof(*dyn_v), M_IPFW,
717 for (i = 0 ; i < nbuckets; i++)
718 IPFW_BUCK_LOCK_INIT(&dyn_v[i]);
721 * Call upper half lock, as get_map() do to ease
722 * read-only access to dynamic rules hash from sysctl
724 IPFW_UH_WLOCK(chain);
727 * Acquire chain write lock to permit hash access
728 * for main traffic path without additional locks
732 /* Save old values */
733 nbuckets_old = V_curr_dyn_buckets;
734 dyn_v_old = V_ipfw_dyn_v;
736 /* Skip relinking if array is not set up */
737 if (V_ipfw_dyn_v == NULL)
738 V_curr_dyn_buckets = 0;
740 /* Re-link all dynamic states */
741 for (i = 0 ; i < V_curr_dyn_buckets ; i++) {
742 while (V_ipfw_dyn_v[i].head != NULL) {
743 /* Remove from current chain */
744 q = V_ipfw_dyn_v[i].head;
745 V_ipfw_dyn_v[i].head = q->next;
747 /* Get new hash value */
748 k = hash_packet(&q->id, nbuckets);
750 /* Add to the new head */
751 q->next = dyn_v[k].head;
756 /* Update current pointers/buckets values */
757 V_curr_dyn_buckets = nbuckets;
758 V_ipfw_dyn_v = dyn_v;
762 IPFW_UH_WUNLOCK(chain);
764 /* Start periodic callout on initial creation */
765 if (dyn_v_old == NULL) {
766 callout_reset_on(&V_ipfw_timeout, hz, ipfw_dyn_tick, curvnet, 0);
770 /* Destroy all mutexes */
771 for (i = 0 ; i < nbuckets_old ; i++)
772 IPFW_BUCK_LOCK_DESTROY(&dyn_v_old[i]);
775 free(dyn_v_old, M_IPFW);
781 * Install state of type 'type' for a dynamic session.
782 * The hash table contains two type of rules:
783 * - regular rules (O_KEEP_STATE)
784 * - rules for sessions with limited number of sess per user
785 * (O_LIMIT). When they are created, the parent is
786 * increased by 1, and decreased on delete. In this case,
787 * the third parameter is the parent rule and not the chain.
788 * - "parent" rules for the above (O_LIMIT_PARENT).
790 static ipfw_dyn_rule *
791 add_dyn_rule(struct ipfw_flow_id *id, int i, uint8_t dyn_type,
792 struct ip_fw *rule, uint16_t kidx)
798 r = uma_zalloc(V_ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO);
800 if (last_log != time_uptime) {
801 last_log = time_uptime;
803 "ipfw: Cannot allocate dynamic state, "
804 "consider increasing net.inet.ip.fw.dyn_max\n");
811 * refcount on parent is already incremented, so
812 * it is safe to use parent unlocked.
814 if (dyn_type == O_LIMIT) {
815 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
816 if ( parent->dyn_type != O_LIMIT_PARENT)
817 panic("invalid parent");
823 r->expire = time_uptime + V_dyn_syn_lifetime;
825 r->dyn_type = dyn_type;
826 IPFW_ZERO_DYN_COUNTER(r);
830 r->next = V_ipfw_dyn_v[i].head;
831 V_ipfw_dyn_v[i].head = r;
832 DEB(print_dyn_rule(id, dyn_type, "add dyn entry", "total");)
837 * lookup dynamic parent rule using pkt and rule as search keys.
838 * If the lookup fails, then install one.
840 static ipfw_dyn_rule *
841 lookup_dyn_parent(struct ipfw_flow_id *pkt, int *pindex, struct ip_fw *rule,
847 is_v6 = IS_IP6_FLOW_ID(pkt);
848 i = hash_packet( pkt, V_curr_dyn_buckets );
851 for (q = V_ipfw_dyn_v[i].head ; q != NULL ; q=q->next)
852 if (q->dyn_type == O_LIMIT_PARENT &&
855 pkt->proto == q->id.proto &&
856 pkt->src_port == q->id.src_port &&
857 pkt->dst_port == q->id.dst_port &&
860 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6),
862 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6),
863 &(q->id.dst_ip6))) ||
865 pkt->src_ip == q->id.src_ip &&
866 pkt->dst_ip == q->id.dst_ip)
869 q->expire = time_uptime + V_dyn_short_lifetime;
870 DEB(print_dyn_rule(pkt, q->dyn_type,
871 "lookup_dyn_parent found", "");)
875 /* Add virtual limiting rule */
876 return add_dyn_rule(pkt, i, O_LIMIT_PARENT, rule, kidx);
880 * Install dynamic state for rule type cmd->o.opcode
882 * Returns 1 (failure) if state is not installed because of errors or because
883 * session limitations are enforced.
886 ipfw_install_state(struct ip_fw_chain *chain, struct ip_fw *rule,
887 ipfw_insn_limit *cmd, struct ip_fw_args *args, uint32_t tablearg)
892 DEB(print_dyn_rule(&args->f_id, cmd->o.opcode, "install_state",
893 (cmd->o.arg1 == 0 ? "": DYN_STATE_OBJ(chain, &cmd->o)->name));)
895 i = hash_packet(&args->f_id, V_curr_dyn_buckets);
899 q = lookup_dyn_rule_locked(&args->f_id, i, NULL, NULL, cmd->o.arg1);
900 if (q != NULL) { /* should never occur */
902 if (last_log != time_uptime) {
903 last_log = time_uptime;
904 printf("ipfw: %s: entry already present, done\n",
912 * State limiting is done via uma(9) zone limiting.
913 * Save pointer to newly-installed rule and reject
914 * packet if add_dyn_rule() returned NULL.
915 * Note q is currently set to NULL.
918 switch (cmd->o.opcode) {
919 case O_KEEP_STATE: /* bidir rule */
920 q = add_dyn_rule(&args->f_id, i, O_KEEP_STATE, rule,
924 case O_LIMIT: { /* limit number of sessions */
925 struct ipfw_flow_id id;
926 ipfw_dyn_rule *parent;
928 uint16_t limit_mask = cmd->limit_mask;
931 conn_limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit);
934 if (cmd->conn_limit == IP_FW_TARG)
935 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u "
936 "(tablearg)\n", __func__, conn_limit);
938 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u\n",
939 __func__, conn_limit);
942 id.dst_ip = id.src_ip = id.dst_port = id.src_port = 0;
943 id.proto = args->f_id.proto;
944 id.addr_type = args->f_id.addr_type;
945 id.fib = M_GETFIB(args->m);
947 if (IS_IP6_FLOW_ID (&(args->f_id))) {
948 bzero(&id.src_ip6, sizeof(id.src_ip6));
949 bzero(&id.dst_ip6, sizeof(id.dst_ip6));
951 if (limit_mask & DYN_SRC_ADDR)
952 id.src_ip6 = args->f_id.src_ip6;
953 if (limit_mask & DYN_DST_ADDR)
954 id.dst_ip6 = args->f_id.dst_ip6;
956 if (limit_mask & DYN_SRC_ADDR)
957 id.src_ip = args->f_id.src_ip;
958 if (limit_mask & DYN_DST_ADDR)
959 id.dst_ip = args->f_id.dst_ip;
961 if (limit_mask & DYN_SRC_PORT)
962 id.src_port = args->f_id.src_port;
963 if (limit_mask & DYN_DST_PORT)
964 id.dst_port = args->f_id.dst_port;
967 * We have to release lock for previous bucket to
968 * avoid possible deadlock
972 parent = lookup_dyn_parent(&id, &pindex, rule, cmd->o.arg1);
973 if (parent == NULL) {
974 printf("ipfw: %s: add parent failed\n", __func__);
975 IPFW_BUCK_UNLOCK(pindex);
979 if (parent->count >= conn_limit) {
980 if (V_fw_verbose && last_log != time_uptime) {
982 last_log = time_uptime;
983 snprintf(sbuf, sizeof(sbuf),
985 parent->rule->rulenum);
986 print_dyn_rule_flags(&args->f_id,
988 LOG_SECURITY | LOG_DEBUG,
989 sbuf, "too many entries");
991 IPFW_BUCK_UNLOCK(pindex);
994 /* Increment counter on parent */
996 IPFW_BUCK_UNLOCK(pindex);
999 q = add_dyn_rule(&args->f_id, i, O_LIMIT,
1000 (struct ip_fw *)parent, cmd->o.arg1);
1002 /* Decrement index and notify caller */
1003 IPFW_BUCK_UNLOCK(i);
1004 IPFW_BUCK_LOCK(pindex);
1006 IPFW_BUCK_UNLOCK(pindex);
1012 printf("ipfw: %s: unknown dynamic rule type %u\n",
1013 __func__, cmd->o.opcode);
1017 IPFW_BUCK_UNLOCK(i);
1018 return (1); /* Notify caller about failure */
1021 dyn_update_proto_state(q, &args->f_id, NULL, MATCH_FORWARD);
1022 IPFW_BUCK_UNLOCK(i);
1027 * Generate a TCP packet, containing either a RST or a keepalive.
1028 * When flags & TH_RST, we are sending a RST packet, because of a
1029 * "reset" action matched the packet.
1030 * Otherwise we are sending a keepalive, and flags & TH_
1031 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required
1032 * so that MAC can label the reply appropriately.
1035 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq,
1036 u_int32_t ack, int flags)
1038 struct mbuf *m = NULL; /* stupid compiler */
1040 struct ip *h = NULL; /* stupid compiler */
1042 struct ip6_hdr *h6 = NULL;
1044 struct tcphdr *th = NULL;
1046 MGETHDR(m, M_NOWAIT, MT_DATA);
1050 M_SETFIB(m, id->fib);
1052 if (replyto != NULL)
1053 mac_netinet_firewall_reply(replyto, m);
1055 mac_netinet_firewall_send(m);
1057 (void)replyto; /* don't warn about unused arg */
1060 switch (id->addr_type) {
1062 len = sizeof(struct ip) + sizeof(struct tcphdr);
1066 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1070 /* XXX: log me?!? */
1074 dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN);
1076 m->m_data += max_linkhdr;
1077 m->m_flags |= M_SKIP_FIREWALL;
1078 m->m_pkthdr.len = m->m_len = len;
1079 m->m_pkthdr.rcvif = NULL;
1080 bzero(m->m_data, len);
1082 switch (id->addr_type) {
1084 h = mtod(m, struct ip *);
1086 /* prepare for checksum */
1087 h->ip_p = IPPROTO_TCP;
1088 h->ip_len = htons(sizeof(struct tcphdr));
1090 h->ip_src.s_addr = htonl(id->src_ip);
1091 h->ip_dst.s_addr = htonl(id->dst_ip);
1093 h->ip_src.s_addr = htonl(id->dst_ip);
1094 h->ip_dst.s_addr = htonl(id->src_ip);
1097 th = (struct tcphdr *)(h + 1);
1101 h6 = mtod(m, struct ip6_hdr *);
1103 /* prepare for checksum */
1104 h6->ip6_nxt = IPPROTO_TCP;
1105 h6->ip6_plen = htons(sizeof(struct tcphdr));
1107 h6->ip6_src = id->src_ip6;
1108 h6->ip6_dst = id->dst_ip6;
1110 h6->ip6_src = id->dst_ip6;
1111 h6->ip6_dst = id->src_ip6;
1114 th = (struct tcphdr *)(h6 + 1);
1120 th->th_sport = htons(id->src_port);
1121 th->th_dport = htons(id->dst_port);
1123 th->th_sport = htons(id->dst_port);
1124 th->th_dport = htons(id->src_port);
1126 th->th_off = sizeof(struct tcphdr) >> 2;
1128 if (flags & TH_RST) {
1129 if (flags & TH_ACK) {
1130 th->th_seq = htonl(ack);
1131 th->th_flags = TH_RST;
1135 th->th_ack = htonl(seq);
1136 th->th_flags = TH_RST | TH_ACK;
1140 * Keepalive - use caller provided sequence numbers
1142 th->th_seq = htonl(seq);
1143 th->th_ack = htonl(ack);
1144 th->th_flags = TH_ACK;
1147 switch (id->addr_type) {
1149 th->th_sum = in_cksum(m, len);
1151 /* finish the ip header */
1153 h->ip_hl = sizeof(*h) >> 2;
1154 h->ip_tos = IPTOS_LOWDELAY;
1155 h->ip_off = htons(0);
1156 h->ip_len = htons(len);
1157 h->ip_ttl = V_ip_defttl;
1162 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6),
1163 sizeof(struct tcphdr));
1165 /* finish the ip6 header */
1166 h6->ip6_vfc |= IPV6_VERSION;
1167 h6->ip6_hlim = IPV6_DEFHLIM;
1176 * Queue keepalive packets for given dynamic rule
1178 static struct mbuf **
1179 ipfw_dyn_send_ka(struct mbuf **mtailp, ipfw_dyn_rule *q)
1181 struct mbuf *m_rev, *m_fwd;
1183 m_rev = (q->state & ACK_REV) ? NULL :
1184 ipfw_send_pkt(NULL, &(q->id), q->ack_rev - 1, q->ack_fwd, TH_SYN);
1185 m_fwd = (q->state & ACK_FWD) ? NULL :
1186 ipfw_send_pkt(NULL, &(q->id), q->ack_fwd - 1, q->ack_rev, 0);
1188 if (m_rev != NULL) {
1190 mtailp = &(*mtailp)->m_nextpkt;
1192 if (m_fwd != NULL) {
1194 mtailp = &(*mtailp)->m_nextpkt;
1201 * This procedure is used to perform various maintenance
1202 * on dynamic hash list. Currently it is called every second.
1205 ipfw_dyn_tick(void * vnetx)
1207 struct ip_fw_chain *chain;
1210 struct vnet *vp = vnetx;
1215 chain = &V_layer3_chain;
1217 /* Run keepalive checks every keepalive_period iff ka is enabled */
1218 if ((V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) &&
1219 (V_dyn_keepalive != 0)) {
1220 V_dyn_keepalive_last = time_uptime;
1224 check_dyn_rules(chain, NULL, check_ka, 1);
1226 callout_reset_on(&V_ipfw_timeout, hz, ipfw_dyn_tick, vnetx, 0);
1233 * Walk through all dynamic states doing generic maintenance:
1234 * 1) free expired states
1235 * 2) free all states based on deleted rule / set
1236 * 3) send keepalives for states if needed
1238 * @chain - pointer to current ipfw rules chain
1239 * @rule - delete all states originated by given rule if != NULL
1240 * @set - delete all states originated by any rule in set @set if != RESVD_SET
1241 * @check_ka - perform checking/sending keepalives
1242 * @timer - indicate call from timer routine.
1244 * Timer routine must call this function unlocked to permit
1245 * sending keepalives/resizing table.
1247 * Others has to call function with IPFW_UH_WLOCK held.
1248 * Additionally, function assume that dynamic rule/set is
1249 * ALREADY deleted so no new states can be generated by
1252 * Write lock is needed to ensure that unused parent rules
1253 * are not freed by other instance (see stage 2, 3)
1256 check_dyn_rules(struct ip_fw_chain *chain, ipfw_range_tlv *rt,
1257 int check_ka, int timer)
1259 struct mbuf *m0, *m, *mnext, **mtailp;
1261 int i, dyn_count, new_buckets = 0, max_buckets;
1262 int expired = 0, expired_limits = 0, parents = 0, total = 0;
1263 ipfw_dyn_rule *q, *q_prev, *q_next;
1264 ipfw_dyn_rule *exp_head, **exptailp;
1265 ipfw_dyn_rule *exp_lhead, **expltailp;
1267 KASSERT(V_ipfw_dyn_v != NULL, ("%s: dynamic table not allocated",
1270 /* Avoid possible LOR */
1271 KASSERT(!check_ka || timer, ("%s: keepalive check with lock held",
1275 * Do not perform any checks if we currently have no dynamic states
1280 /* Expired states */
1282 exptailp = &exp_head;
1284 /* Expired limit states */
1286 expltailp = &exp_lhead;
1289 * We make a chain of packets to go out here -- not deferring
1290 * until after we drop the IPFW dynamic rule lock would result
1291 * in a lock order reversal with the normal packet input -> ipfw
1297 /* Protect from hash resizing */
1299 IPFW_UH_WLOCK(chain);
1301 IPFW_UH_WLOCK_ASSERT(chain);
1303 #define NEXT_RULE() { q_prev = q; q = q->next ; continue; }
1305 /* Stage 1: perform requested deletion */
1306 for (i = 0 ; i < V_curr_dyn_buckets ; i++) {
1308 for (q = V_ipfw_dyn_v[i].head, q_prev = q; q ; ) {
1309 /* account every rule */
1312 /* Skip parent rules at all */
1313 if (q->dyn_type == O_LIMIT_PARENT) {
1319 * Remove rules which are:
1321 * 2) matches deletion range
1323 if ((TIME_LEQ(q->expire, time_uptime)) ||
1324 (rt != NULL && ipfw_match_range(q->rule, rt))) {
1325 if (TIME_LE(time_uptime, q->expire) &&
1326 q->dyn_type == O_KEEP_STATE &&
1327 V_dyn_keep_states != 0) {
1329 * Do not delete state if
1330 * it is not expired and
1331 * dyn_keep_states is ON.
1332 * However we need to re-link it
1333 * to any other stable rule
1335 q->rule = chain->default_rule;
1339 /* Unlink q from current list */
1341 if (q == V_ipfw_dyn_v[i].head)
1342 V_ipfw_dyn_v[i].head = q_next;
1344 q_prev->next = q_next;
1348 /* queue q to expire list */
1349 if (q->dyn_type != O_LIMIT) {
1351 exptailp = &(*exptailp)->next;
1352 DEB(print_dyn_rule(&q->id, q->dyn_type,
1353 "unlink entry", "left");
1356 /* Separate list for limit rules */
1358 expltailp = &(*expltailp)->next;
1360 DEB(print_dyn_rule(&q->id, q->dyn_type,
1361 "unlink limit entry", "left");
1371 * Check if we need to send keepalive:
1372 * we need to ensure if is time to do KA,
1373 * this is established TCP session, and
1374 * expire time is within keepalive interval
1376 if ((check_ka != 0) && (q->id.proto == IPPROTO_TCP) &&
1377 ((q->state & BOTH_SYN) == BOTH_SYN) &&
1378 (TIME_LEQ(q->expire, time_uptime +
1379 V_dyn_keepalive_interval)))
1380 mtailp = ipfw_dyn_send_ka(mtailp, q);
1384 IPFW_BUCK_UNLOCK(i);
1387 /* Stage 2: decrement counters from O_LIMIT parents */
1388 if (expired_limits != 0) {
1390 * XXX: Note that deleting set with more than one
1391 * heavily-used LIMIT rules can result in overwhelming
1392 * locking due to lack of per-hash value sorting
1394 * We should probably think about:
1395 * 1) pre-allocating hash of size, say,
1396 * MAX(16, V_curr_dyn_buckets / 1024)
1397 * 2) checking if expired_limits is large enough
1398 * 3) If yes, init hash (or its part), re-link
1399 * current list and start decrementing procedure in
1400 * each bucket separately
1404 * Small optimization: do not unlock bucket until
1405 * we see the next item resides in different bucket
1407 if (exp_lhead != NULL) {
1408 i = exp_lhead->parent->bucket;
1411 for (q = exp_lhead; q != NULL; q = q->next) {
1412 if (i != q->parent->bucket) {
1413 IPFW_BUCK_UNLOCK(i);
1414 i = q->parent->bucket;
1418 /* Decrease parent refcount */
1421 if (exp_lhead != NULL)
1422 IPFW_BUCK_UNLOCK(i);
1426 * We protectet ourselves from unused parent deletion
1427 * (from the timer function) by holding UH write lock.
1430 /* Stage 3: remove unused parent rules */
1431 if ((parents != 0) && (expired != 0)) {
1432 for (i = 0 ; i < V_curr_dyn_buckets ; i++) {
1434 for (q = V_ipfw_dyn_v[i].head, q_prev = q ; q ; ) {
1435 if (q->dyn_type != O_LIMIT_PARENT)
1441 /* Parent rule without consumers */
1443 /* Unlink q from current list */
1445 if (q == V_ipfw_dyn_v[i].head)
1446 V_ipfw_dyn_v[i].head = q_next;
1448 q_prev->next = q_next;
1452 /* Add to expired list */
1454 exptailp = &(*exptailp)->next;
1456 DEB(print_dyn_rule(&q->id, q->dyn_type,
1457 "unlink parent entry", "left");
1464 IPFW_BUCK_UNLOCK(i);
1472 * Check if we need to resize hash:
1473 * if current number of states exceeds number of buckes in hash,
1474 * grow hash size to the minimum power of 2 which is bigger than
1475 * current states count. Limit hash size by 64k.
1477 max_buckets = (V_dyn_buckets_max > 65536) ?
1478 65536 : V_dyn_buckets_max;
1480 dyn_count = DYN_COUNT;
1482 if ((dyn_count > V_curr_dyn_buckets * 2) &&
1483 (dyn_count < max_buckets)) {
1484 new_buckets = V_curr_dyn_buckets;
1485 while (new_buckets < dyn_count) {
1488 if (new_buckets >= max_buckets)
1493 IPFW_UH_WUNLOCK(chain);
1496 /* Finally delete old states ad limits if any */
1497 for (q = exp_head; q != NULL; q = q_next) {
1499 uma_zfree(V_ipfw_dyn_rule_zone, q);
1503 for (q = exp_lhead; q != NULL; q = q_next) {
1505 uma_zfree(V_ipfw_dyn_rule_zone, q);
1510 * The rest code MUST be called from timer routine only
1511 * without holding any locks
1516 /* Send keepalive packets if any */
1517 for (m = m0; m != NULL; m = mnext) {
1518 mnext = m->m_nextpkt;
1519 m->m_nextpkt = NULL;
1520 h = mtod(m, struct ip *);
1522 ip_output(m, NULL, NULL, 0, NULL, NULL);
1525 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
1529 /* Run table resize without holding any locks */
1530 if (new_buckets != 0)
1531 resize_dynamic_table(chain, new_buckets);
1535 * Deletes all dynamic rules originated by given rule or all rules in
1536 * given set. Specify RESVD_SET to indicate set should not be used.
1537 * @chain - pointer to current ipfw rules chain
1538 * @rr - delete all states originated by rules in matched range.
1540 * Function has to be called with IPFW_UH_WLOCK held.
1541 * Additionally, function assume that dynamic rule/set is
1542 * ALREADY deleted so no new states can be generated by
1546 ipfw_expire_dyn_rules(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
1549 check_dyn_rules(chain, rt, 0, 0);
1553 * Check if rule contains at least one dynamic opcode.
1555 * Returns 1 if such opcode is found, 0 otherwise.
1558 ipfw_is_dyn_rule(struct ip_fw *rule)
1566 for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) {
1567 cmdlen = F_LEN(cmd);
1569 switch (cmd->opcode) {
1582 ipfw_dyn_init(struct ip_fw_chain *chain)
1585 V_ipfw_dyn_v = NULL;
1586 V_dyn_buckets_max = 256; /* must be power of 2 */
1587 V_curr_dyn_buckets = 256; /* must be power of 2 */
1589 V_dyn_ack_lifetime = 300;
1590 V_dyn_syn_lifetime = 20;
1591 V_dyn_fin_lifetime = 1;
1592 V_dyn_rst_lifetime = 1;
1593 V_dyn_udp_lifetime = 10;
1594 V_dyn_short_lifetime = 5;
1596 V_dyn_keepalive_interval = 20;
1597 V_dyn_keepalive_period = 5;
1598 V_dyn_keepalive = 1; /* do send keepalives */
1599 V_dyn_keepalive_last = time_uptime;
1601 V_dyn_max = 16384; /* max # of dynamic rules */
1603 V_ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule",
1604 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL,
1607 /* Enforce limit on dynamic rules */
1608 uma_zone_set_max(V_ipfw_dyn_rule_zone, V_dyn_max);
1610 callout_init(&V_ipfw_timeout, 1);
1613 * This can potentially be done on first dynamic rule
1614 * being added to chain.
1616 resize_dynamic_table(chain, V_curr_dyn_buckets);
1617 IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
1621 ipfw_dyn_uninit(int pass)
1626 callout_drain(&V_ipfw_timeout);
1629 IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
1631 if (V_ipfw_dyn_v != NULL) {
1633 * Skip deleting all dynamic states -
1634 * uma_zdestroy() does this more efficiently;
1637 /* Destroy all mutexes */
1638 for (i = 0 ; i < V_curr_dyn_buckets ; i++)
1639 IPFW_BUCK_LOCK_DESTROY(&V_ipfw_dyn_v[i]);
1640 free(V_ipfw_dyn_v, M_IPFW);
1641 V_ipfw_dyn_v = NULL;
1644 uma_zdestroy(V_ipfw_dyn_rule_zone);
1649 * Get/set maximum number of dynamic states in given VNET instance.
1652 sysctl_ipfw_dyn_max(SYSCTL_HANDLER_ARGS)
1655 unsigned int nstates;
1657 nstates = V_dyn_max;
1659 error = sysctl_handle_int(oidp, &nstates, 0, req);
1660 /* Read operation or some error */
1661 if ((error != 0) || (req->newptr == NULL))
1664 V_dyn_max = nstates;
1665 uma_zone_set_max(V_ipfw_dyn_rule_zone, V_dyn_max);
1671 * Get current number of dynamic states in given VNET instance.
1674 sysctl_ipfw_dyn_count(SYSCTL_HANDLER_ARGS)
1677 unsigned int nstates;
1679 nstates = DYN_COUNT;
1681 error = sysctl_handle_int(oidp, &nstates, 0, req);
1688 * Returns size of dynamic states in legacy format
1694 return (V_ipfw_dyn_v == NULL) ? 0 :
1695 (DYN_COUNT * sizeof(ipfw_dyn_rule));
1699 * Returns number of dynamic states.
1700 * Used by dump format v1 (current).
1703 ipfw_dyn_get_count(void)
1706 return (V_ipfw_dyn_v == NULL) ? 0 : DYN_COUNT;
1710 export_dyn_rule(ipfw_dyn_rule *src, ipfw_dyn_rule *dst)
1714 rulenum = (uint16_t)src->rule->rulenum;
1715 memcpy(dst, src, sizeof(*src));
1716 memcpy(&dst->rule, &rulenum, sizeof(rulenum));
1718 * store set number into high word of
1719 * dst->rule pointer.
1721 memcpy((char *)&dst->rule + sizeof(rulenum), &src->rule->set,
1722 sizeof(src->rule->set));
1724 * store a non-null value in "next".
1725 * The userland code will interpret a
1726 * NULL here as a marker
1727 * for the last dynamic rule.
1729 memcpy(&dst->next, &dst, sizeof(dst));
1730 dst->expire = TIME_LEQ(dst->expire, time_uptime) ? 0:
1731 dst->expire - time_uptime;
1735 * Fills int buffer given by @sd with dynamic states.
1736 * Used by dump format v1 (current).
1738 * Returns 0 on success.
1741 ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd)
1744 ipfw_obj_dyntlv *dst, *last;
1745 ipfw_obj_ctlv *ctlv;
1749 if (V_ipfw_dyn_v == NULL)
1752 IPFW_UH_RLOCK_ASSERT(chain);
1754 ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
1757 sz = sizeof(ipfw_obj_dyntlv);
1758 ctlv->head.type = IPFW_TLV_DYNSTATE_LIST;
1762 for (i = 0 ; i < V_curr_dyn_buckets; i++) {
1764 for (p = V_ipfw_dyn_v[i].head ; p != NULL; p = p->next) {
1765 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd, sz);
1767 IPFW_BUCK_UNLOCK(i);
1771 export_dyn_rule(p, &dst->state);
1772 dst->head.length = sz;
1773 dst->head.type = IPFW_TLV_DYN_ENT;
1776 IPFW_BUCK_UNLOCK(i);
1779 if (last != NULL) /* mark last dynamic rule */
1780 last->head.flags = IPFW_DF_LAST;
1786 * Fill given buffer with dynamic states (legacy format).
1787 * IPFW_UH_RLOCK has to be held while calling.
1790 ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep)
1792 ipfw_dyn_rule *p, *last = NULL;
1796 if (V_ipfw_dyn_v == NULL)
1800 IPFW_UH_RLOCK_ASSERT(chain);
1802 for (i = 0 ; i < V_curr_dyn_buckets; i++) {
1804 for (p = V_ipfw_dyn_v[i].head ; p != NULL; p = p->next) {
1805 if (bp + sizeof *p <= ep) {
1806 ipfw_dyn_rule *dst =
1807 (ipfw_dyn_rule *)bp;
1809 export_dyn_rule(p, dst);
1811 bp += sizeof(ipfw_dyn_rule);
1814 IPFW_BUCK_UNLOCK(i);
1817 if (last != NULL) /* mark last dynamic rule */
1818 bzero(&last->next, sizeof(last));