1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2017-2018 Yandex LLC
5 * Copyright (c) 2017-2018 Andrey V. Elsukov <ae@FreeBSD.org>
6 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 #include "opt_ipfw.h"
36 #ifndef INET
37 #error IPFIREWALL requires INET.
38 #endif /* INET */
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/hash.h>
43 #include <sys/mbuf.h>
44 #include <sys/kernel.h>
45 #include <sys/lock.h>
46 #include <sys/pcpu.h>
47 #include <sys/queue.h>
48 #include <sys/rmlock.h>
49 #include <sys/smp.h>
50 #include <sys/socket.h>
51 #include <sys/sysctl.h>
52 #include <sys/syslog.h>
53 #include <net/ethernet.h>
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <net/vnet.h>
57
58 #include <netinet/in.h>
59 #include <netinet/ip.h>
60 #include <netinet/ip_var.h>
61 #include <netinet/ip_fw.h>
62 #include <netinet/udp.h>
63 #include <netinet/tcp.h>
64
65 #include <netinet/ip6.h> /* IN6_ARE_ADDR_EQUAL */
66 #ifdef INET6
67 #include <netinet6/in6_var.h>
68 #include <netinet6/ip6_var.h>
69 #include <netinet6/scope6_var.h>
70 #endif
71
72 #include <netpfil/ipfw/ip_fw_private.h>
73
74 #include <machine/in_cksum.h> /* XXX for in_cksum */
75
76 #ifdef MAC
77 #include <security/mac/mac_framework.h>
78 #endif
79
80 /*
81 * Description of dynamic states.
82 *
83 * Dynamic states are stored in lists accessed through a hash tables
84 * whose size is curr_dyn_buckets. This value can be modified through
85 * the sysctl variable dyn_buckets.
86 *
87 * Currently there are four tables: dyn_ipv4, dyn_ipv6, dyn_ipv4_parent,
88 * and dyn_ipv6_parent.
89 *
90 * When a packet is received, its address fields hashed, then matched
91 * against the entries in the corresponding list by addr_type.
92 * Dynamic states can be used for different purposes:
93 * + stateful rules;
94 * + enforcing limits on the number of sessions;
95 * + in-kernel NAT (not implemented yet)
96 *
97 * The lifetime of dynamic states is regulated by dyn_*_lifetime,
98 * measured in seconds and depending on the flags.
99 *
100 * The total number of dynamic states is equal to UMA zone items count.
101 * The max number of dynamic states is dyn_max. When we reach
102 * the maximum number of rules we do not create anymore. This is
103 * done to avoid consuming too much memory, but also too much
104 * time when searching on each packet (ideally, we should try instead
105 * to put a limit on the length of the list on each bucket...).
106 *
107 * Each state holds a pointer to the parent ipfw rule so we know what
108 * action to perform. Dynamic rules are removed when the parent rule is
109 * deleted.
110 *
111 * There are some limitations with dynamic rules -- we do not
112 * obey the 'randomized match', and we do not do multiple
113 * passes through the firewall. XXX check the latter!!!
114 */
115
116 /* By default use jenkins hash function */
117 #define IPFIREWALL_JENKINSHASH
118
119 #define DYN_COUNTER_INC(d, dir, pktlen) do { \
120 (d)->pcnt_ ## dir++; \
121 (d)->bcnt_ ## dir += pktlen; \
122 } while (0)
123
124 #define DYN_REFERENCED 0x01
125 /*
126 * DYN_REFERENCED flag is used to show that state keeps reference to named
127 * object, and this reference should be released when state becomes expired.
128 */
129
130 struct dyn_data {
131 void *parent; /* pointer to parent rule */
132 uint32_t chain_id; /* cached ruleset id */
133 uint32_t f_pos; /* cached rule index */
134
135 uint32_t hashval; /* hash value used for hash resize */
136 uint16_t fibnum; /* fib used to send keepalives */
137 uint8_t _pad[3];
138 uint8_t flags; /* internal flags */
139 uint16_t rulenum; /* parent rule number */
140 uint32_t ruleid; /* parent rule id */
141
142 uint32_t state; /* TCP session state and flags */
143 uint32_t ack_fwd; /* most recent ACKs in forward */
144 uint32_t ack_rev; /* and reverse direction (used */
145 /* to generate keepalives) */
146 uint32_t sync; /* synchronization time */
147 uint32_t expire; /* expire time */
148
149 uint64_t pcnt_fwd; /* bytes counter in forward */
150 uint64_t bcnt_fwd; /* packets counter in forward */
151 uint64_t pcnt_rev; /* bytes counter in reverse */
152 uint64_t bcnt_rev; /* packets counter in reverse */
153 };
154
155 #define DPARENT_COUNT_DEC(p) do { \
156 MPASS(p->count > 0); \
157 ck_pr_dec_32(&(p)->count); \
158 } while (0)
159 #define DPARENT_COUNT_INC(p) ck_pr_inc_32(&(p)->count)
160 #define DPARENT_COUNT(p) ck_pr_load_32(&(p)->count)
161 struct dyn_parent {
162 void *parent; /* pointer to parent rule */
163 uint32_t count; /* number of linked states */
164 uint8_t _pad[2];
165 uint16_t rulenum; /* parent rule number */
166 uint32_t ruleid; /* parent rule id */
167 uint32_t hashval; /* hash value used for hash resize */
168 uint32_t expire; /* expire time */
169 };
170
171 struct dyn_ipv4_state {
172 uint8_t type; /* State type */
173 uint8_t proto; /* UL Protocol */
174 uint16_t kidx; /* named object index */
175 uint16_t sport, dport; /* ULP source and destination ports */
176 in_addr_t src, dst; /* IPv4 source and destination */
177
178 union {
179 struct dyn_data *data;
180 struct dyn_parent *limit;
181 };
182 CK_SLIST_ENTRY(dyn_ipv4_state) entry;
183 SLIST_ENTRY(dyn_ipv4_state) expired;
184 };
185 CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state);
186 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4);
187 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4_parent);
188
189 SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state);
190 VNET_DEFINE_STATIC(struct dyn_ipv4_slist, dyn_expired_ipv4);
191 #define V_dyn_ipv4 VNET(dyn_ipv4)
192 #define V_dyn_ipv4_parent VNET(dyn_ipv4_parent)
193 #define V_dyn_expired_ipv4 VNET(dyn_expired_ipv4)
194
195 #ifdef INET6
196 struct dyn_ipv6_state {
197 uint8_t type; /* State type */
198 uint8_t proto; /* UL Protocol */
199 uint16_t kidx; /* named object index */
200 uint16_t sport, dport; /* ULP source and destination ports */
201 struct in6_addr src, dst; /* IPv6 source and destination */
202 uint32_t zoneid; /* IPv6 scope zone id */
203 union {
204 struct dyn_data *data;
205 struct dyn_parent *limit;
206 };
207 CK_SLIST_ENTRY(dyn_ipv6_state) entry;
208 SLIST_ENTRY(dyn_ipv6_state) expired;
209 };
210 CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state);
211 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6);
212 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6_parent);
213
214 SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state);
215 VNET_DEFINE_STATIC(struct dyn_ipv6_slist, dyn_expired_ipv6);
216 #define V_dyn_ipv6 VNET(dyn_ipv6)
217 #define V_dyn_ipv6_parent VNET(dyn_ipv6_parent)
218 #define V_dyn_expired_ipv6 VNET(dyn_expired_ipv6)
219 #endif /* INET6 */
220
221 /*
222 * Per-CPU pointer indicates that specified state is currently in use
223 * and must not be reclaimed by expiration callout.
224 */
225 static void **dyn_hp_cache;
226 DPCPU_DEFINE_STATIC(void *, dyn_hp);
227 #define DYNSTATE_GET(cpu) ck_pr_load_ptr(DPCPU_ID_PTR((cpu), dyn_hp))
228 #define DYNSTATE_PROTECT(v) ck_pr_store_ptr(DPCPU_PTR(dyn_hp), (v))
229 #define DYNSTATE_RELEASE() DYNSTATE_PROTECT(NULL)
230 #define DYNSTATE_CRITICAL_ENTER() critical_enter()
231 #define DYNSTATE_CRITICAL_EXIT() do { \
232 DYNSTATE_RELEASE(); \
233 critical_exit(); \
234 } while (0);
235
236 /*
237 * We keep two version numbers, one is updated when new entry added to
238 * the list. Second is updated when an entry deleted from the list.
239 * Versions are updated under bucket lock.
240 *
241 * Bucket "add" version number is used to know, that in the time between
242 * state lookup (i.e. ipfw_dyn_lookup_state()) and the followed state
243 * creation (i.e. ipfw_dyn_install_state()) another concurrent thread did
244 * not install some state in this bucket. Using this info we can avoid
245 * additional state lookup, because we are sure that we will not install
246 * the state twice.
247 *
248 * Also doing the tracking of bucket "del" version during lookup we can
249 * be sure, that state entry was not unlinked and freed in time between
250 * we read the state pointer and protect it with hazard pointer.
251 *
252 * An entry unlinked from CK list keeps unchanged until it is freed.
253 * Unlinked entries are linked into expired lists using "expired" field.
254 */
255
256 /*
257 * dyn_expire_lock is used to protect access to dyn_expired_xxx lists.
258 * dyn_bucket_lock is used to get write access to lists in specific bucket.
259 * Currently one dyn_bucket_lock is used for all ipv4, ipv4_parent, ipv6,
260 * and ipv6_parent lists.
261 */
262 VNET_DEFINE_STATIC(struct mtx, dyn_expire_lock);
263 VNET_DEFINE_STATIC(struct mtx *, dyn_bucket_lock);
264 #define V_dyn_expire_lock VNET(dyn_expire_lock)
265 #define V_dyn_bucket_lock VNET(dyn_bucket_lock)
266
267 /*
268 * Bucket's add/delete generation versions.
269 */
270 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_add);
271 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_del);
272 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_add);
273 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_del);
274 #define V_dyn_ipv4_add VNET(dyn_ipv4_add)
275 #define V_dyn_ipv4_del VNET(dyn_ipv4_del)
276 #define V_dyn_ipv4_parent_add VNET(dyn_ipv4_parent_add)
277 #define V_dyn_ipv4_parent_del VNET(dyn_ipv4_parent_del)
278
279 #ifdef INET6
280 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_add);
281 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_del);
282 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_add);
283 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_del);
284 #define V_dyn_ipv6_add VNET(dyn_ipv6_add)
285 #define V_dyn_ipv6_del VNET(dyn_ipv6_del)
286 #define V_dyn_ipv6_parent_add VNET(dyn_ipv6_parent_add)
287 #define V_dyn_ipv6_parent_del VNET(dyn_ipv6_parent_del)
288 #endif /* INET6 */
289
290 #define DYN_BUCKET(h, b) ((h) & (b - 1))
291 #define DYN_BUCKET_VERSION(b, v) ck_pr_load_32(&V_dyn_ ## v[(b)])
292 #define DYN_BUCKET_VERSION_BUMP(b, v) ck_pr_inc_32(&V_dyn_ ## v[(b)])
293
294 #define DYN_BUCKET_LOCK_INIT(lock, b) \
295 mtx_init(&lock[(b)], "IPFW dynamic bucket", NULL, MTX_DEF)
296 #define DYN_BUCKET_LOCK_DESTROY(lock, b) mtx_destroy(&lock[(b)])
297 #define DYN_BUCKET_LOCK(b) mtx_lock(&V_dyn_bucket_lock[(b)])
298 #define DYN_BUCKET_UNLOCK(b) mtx_unlock(&V_dyn_bucket_lock[(b)])
299 #define DYN_BUCKET_ASSERT(b) mtx_assert(&V_dyn_bucket_lock[(b)], MA_OWNED)
300
301 #define DYN_EXPIRED_LOCK_INIT() \
302 mtx_init(&V_dyn_expire_lock, "IPFW expired states list", NULL, MTX_DEF)
303 #define DYN_EXPIRED_LOCK_DESTROY() mtx_destroy(&V_dyn_expire_lock)
304 #define DYN_EXPIRED_LOCK() mtx_lock(&V_dyn_expire_lock)
305 #define DYN_EXPIRED_UNLOCK() mtx_unlock(&V_dyn_expire_lock)
306
307 VNET_DEFINE_STATIC(uint32_t, dyn_buckets_max);
308 VNET_DEFINE_STATIC(uint32_t, curr_dyn_buckets);
309 VNET_DEFINE_STATIC(struct callout, dyn_timeout);
310 #define V_dyn_buckets_max VNET(dyn_buckets_max)
311 #define V_curr_dyn_buckets VNET(curr_dyn_buckets)
312 #define V_dyn_timeout VNET(dyn_timeout)
313
314 /* Maximum length of states chain in a bucket */
315 VNET_DEFINE_STATIC(uint32_t, curr_max_length);
316 #define V_curr_max_length VNET(curr_max_length)
317
318 VNET_DEFINE_STATIC(uint32_t, dyn_keep_states);
319 #define V_dyn_keep_states VNET(dyn_keep_states)
320
321 VNET_DEFINE_STATIC(uma_zone_t, dyn_data_zone);
322 VNET_DEFINE_STATIC(uma_zone_t, dyn_parent_zone);
323 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv4_zone);
324 #ifdef INET6
325 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv6_zone);
326 #define V_dyn_ipv6_zone VNET(dyn_ipv6_zone)
327 #endif /* INET6 */
328 #define V_dyn_data_zone VNET(dyn_data_zone)
329 #define V_dyn_parent_zone VNET(dyn_parent_zone)
330 #define V_dyn_ipv4_zone VNET(dyn_ipv4_zone)
331
332 /*
333 * Timeouts for various events in handing dynamic rules.
334 */
335 VNET_DEFINE_STATIC(uint32_t, dyn_ack_lifetime);
336 VNET_DEFINE_STATIC(uint32_t, dyn_syn_lifetime);
337 VNET_DEFINE_STATIC(uint32_t, dyn_fin_lifetime);
338 VNET_DEFINE_STATIC(uint32_t, dyn_rst_lifetime);
339 VNET_DEFINE_STATIC(uint32_t, dyn_udp_lifetime);
340 VNET_DEFINE_STATIC(uint32_t, dyn_short_lifetime);
341
342 #define V_dyn_ack_lifetime VNET(dyn_ack_lifetime)
343 #define V_dyn_syn_lifetime VNET(dyn_syn_lifetime)
344 #define V_dyn_fin_lifetime VNET(dyn_fin_lifetime)
345 #define V_dyn_rst_lifetime VNET(dyn_rst_lifetime)
346 #define V_dyn_udp_lifetime VNET(dyn_udp_lifetime)
347 #define V_dyn_short_lifetime VNET(dyn_short_lifetime)
348
349 /*
350 * Keepalives are sent if dyn_keepalive is set. They are sent every
351 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
352 * seconds of lifetime of a rule.
353 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
354 * than dyn_keepalive_period.
355 */
356 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_interval);
357 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_period);
358 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive);
359 VNET_DEFINE_STATIC(time_t, dyn_keepalive_last);
360
361 #define V_dyn_keepalive_interval VNET(dyn_keepalive_interval)
362 #define V_dyn_keepalive_period VNET(dyn_keepalive_period)
363 #define V_dyn_keepalive VNET(dyn_keepalive)
364 #define V_dyn_keepalive_last VNET(dyn_keepalive_last)
365
366 VNET_DEFINE_STATIC(uint32_t, dyn_max); /* max # of dynamic states */
367 VNET_DEFINE_STATIC(uint32_t, dyn_count); /* number of states */
368 VNET_DEFINE_STATIC(uint32_t, dyn_parent_max); /* max # of parent states */
369 VNET_DEFINE_STATIC(uint32_t, dyn_parent_count); /* number of parent states */
370
371 #define V_dyn_max VNET(dyn_max)
372 #define V_dyn_count VNET(dyn_count)
373 #define V_dyn_parent_max VNET(dyn_parent_max)
374 #define V_dyn_parent_count VNET(dyn_parent_count)
375
376 #define DYN_COUNT_DEC(name) do { \
377 MPASS((V_ ## name) > 0); \
378 ck_pr_dec_32(&(V_ ## name)); \
379 } while (0)
380 #define DYN_COUNT_INC(name) ck_pr_inc_32(&(V_ ## name))
381 #define DYN_COUNT(name) ck_pr_load_32(&(V_ ## name))
382
383 static time_t last_log; /* Log ratelimiting */
384
385 /*
386 * Get/set maximum number of dynamic states in given VNET instance.
387 */
388 static int
389 sysctl_dyn_max(SYSCTL_HANDLER_ARGS)
390 {
391 uint32_t nstates;
392 int error;
393
394 nstates = V_dyn_max;
395 error = sysctl_handle_32(oidp, &nstates, 0, req);
396 /* Read operation or some error */
397 if ((error != 0) || (req->newptr == NULL))
398 return (error);
399
400 V_dyn_max = nstates;
401 uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
402 return (0);
403 }
404
405 static int
406 sysctl_dyn_parent_max(SYSCTL_HANDLER_ARGS)
407 {
408 uint32_t nstates;
409 int error;
410
411 nstates = V_dyn_parent_max;
412 error = sysctl_handle_32(oidp, &nstates, 0, req);
413 /* Read operation or some error */
414 if ((error != 0) || (req->newptr == NULL))
415 return (error);
416
417 V_dyn_parent_max = nstates;
418 uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
419 return (0);
420 }
421
422 static int
423 sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS)
424 {
425 uint32_t nbuckets;
426 int error;
427
428 nbuckets = V_dyn_buckets_max;
429 error = sysctl_handle_32(oidp, &nbuckets, 0, req);
430 /* Read operation or some error */
431 if ((error != 0) || (req->newptr == NULL))
432 return (error);
433
434 if (nbuckets > 256)
435 V_dyn_buckets_max = 1 << fls(nbuckets - 1);
436 else
437 return (EINVAL);
438 return (0);
439 }
440
441 SYSCTL_DECL(_net_inet_ip_fw);
442
443 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_count,
444 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_count), 0,
445 "Current number of dynamic states.");
446 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_parent_count,
447 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_parent_count), 0,
448 "Current number of parent states. ");
449 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets,
450 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0,
451 "Current number of buckets for states hash table.");
452 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_max_length,
453 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_max_length), 0,
454 "Current maximum length of states chains in hash buckets.");
455 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets,
456 CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
457 0, 0, sysctl_dyn_buckets, "IU",
458 "Max number of buckets for dynamic states hash table.");
459 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max,
460 CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
461 0, 0, sysctl_dyn_max, "IU",
462 "Max number of dynamic states.");
463 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_parent_max,
464 CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
465 0, 0, sysctl_dyn_parent_max, "IU",
466 "Max number of parent dynamic states.");
467 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime,
468 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0,
469 "Lifetime of dynamic states for TCP ACK.");
470 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime,
471 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0,
472 "Lifetime of dynamic states for TCP SYN.");
473 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime,
474 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0,
475 "Lifetime of dynamic states for TCP FIN.");
476 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime,
477 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0,
478 "Lifetime of dynamic states for TCP RST.");
479 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime,
480 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0,
481 "Lifetime of dynamic states for UDP.");
482 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime,
483 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0,
484 "Lifetime of dynamic states for other situations.");
485 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keepalive,
486 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0,
487 "Enable keepalives for dynamic states.");
488 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keep_states,
489 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0,
490 "Do not flush dynamic states on rule deletion");
491
492 #ifdef IPFIREWALL_DYNDEBUG
493 #define DYN_DEBUG(fmt, ...) do { \
494 printf("%s: " fmt "\n", __func__, __VA_ARGS__); \
495 } while (0)
496 #else
497 #define DYN_DEBUG(fmt, ...)
498 #endif /* !IPFIREWALL_DYNDEBUG */
499
500 #ifdef INET6
501 /* Functions to work with IPv6 states */
502 static struct dyn_ipv6_state *dyn_lookup_ipv6_state(
503 const struct ipfw_flow_id *, uint32_t, const void *,
504 struct ipfw_dyn_info *, int);
505 static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *,
506 uint32_t, const void *, int, uint32_t, uint16_t);
507 static struct dyn_ipv6_state *dyn_alloc_ipv6_state(
508 const struct ipfw_flow_id *, uint32_t, uint16_t, uint8_t);
509 static int dyn_add_ipv6_state(void *, uint32_t, uint16_t,
510 const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t,
511 struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
512 static void dyn_export_ipv6_state(const struct dyn_ipv6_state *,
513 ipfw_dyn_rule *);
514
515 static uint32_t dyn_getscopeid(const struct ip_fw_args *);
516 static void dyn_make_keepalive_ipv6(struct mbuf *, const struct in6_addr *,
517 const struct in6_addr *, uint32_t, uint32_t, uint32_t, uint16_t,
518 uint16_t);
519 static void dyn_enqueue_keepalive_ipv6(struct mbufq *,
520 const struct dyn_ipv6_state *);
521 static void dyn_send_keepalive_ipv6(struct ip_fw_chain *);
522
523 static struct dyn_ipv6_state *dyn_lookup_ipv6_parent(
524 const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
525 uint32_t);
526 static struct dyn_ipv6_state *dyn_lookup_ipv6_parent_locked(
527 const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
528 uint32_t);
529 static struct dyn_ipv6_state *dyn_add_ipv6_parent(void *, uint32_t, uint16_t,
530 const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t, uint16_t);
531 #endif /* INET6 */
532
533 /* Functions to work with limit states */
534 static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t,
535 struct ip_fw *, uint32_t, uint32_t, uint16_t);
536 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent(
537 const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
538 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked(
539 const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
540 static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint16_t,
541 uint32_t);
542 static struct dyn_ipv4_state *dyn_add_ipv4_parent(void *, uint32_t, uint16_t,
543 const struct ipfw_flow_id *, uint32_t, uint32_t, uint16_t);
544
545 static void dyn_tick(void *);
546 static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *);
547 static void dyn_free_states(struct ip_fw_chain *);
548 static void dyn_export_parent(const struct dyn_parent *, uint16_t, uint8_t,
549 ipfw_dyn_rule *);
550 static void dyn_export_data(const struct dyn_data *, uint16_t, uint8_t,
551 uint8_t, ipfw_dyn_rule *);
552 static uint32_t dyn_update_tcp_state(struct dyn_data *,
553 const struct ipfw_flow_id *, const struct tcphdr *, int);
554 static void dyn_update_proto_state(struct dyn_data *,
555 const struct ipfw_flow_id *, const void *, int, int);
556
557 /* Functions to work with IPv4 states */
558 struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *,
559 const void *, struct ipfw_dyn_info *, int);
560 static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *,
561 const void *, int, uint32_t, uint16_t);
562 static struct dyn_ipv4_state *dyn_alloc_ipv4_state(
563 const struct ipfw_flow_id *, uint16_t, uint8_t);
564 static int dyn_add_ipv4_state(void *, uint32_t, uint16_t,
565 const struct ipfw_flow_id *, const void *, int, uint32_t,
566 struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
567 static void dyn_export_ipv4_state(const struct dyn_ipv4_state *,
568 ipfw_dyn_rule *);
569
570 /*
571 * Named states support.
572 */
573 static char *default_state_name = "default";
574 struct dyn_state_obj {
575 struct named_object no;
576 char name[64];
577 };
578
579 #define DYN_STATE_OBJ(ch, cmd) \
580 ((struct dyn_state_obj *)SRV_OBJECT(ch, (cmd)->arg1))
581 /*
582 * Classifier callback.
583 * Return 0 if opcode contains object that should be referenced
584 * or rewritten.
585 */
586 static int
587 dyn_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
588 {
589
590 DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
591 /* Don't rewrite "check-state any" */
592 if (cmd->arg1 == 0 &&
593 cmd->opcode == O_CHECK_STATE)
594 return (1);
595
596 *puidx = cmd->arg1;
597 *ptype = 0;
598 return (0);
599 }
600
601 static void
602 dyn_update(ipfw_insn *cmd, uint16_t idx)
603 {
604
605 cmd->arg1 = idx;
606 DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
607 }
608
609 static int
610 dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
611 struct named_object **pno)
612 {
613 ipfw_obj_ntlv *ntlv;
614 const char *name;
615
616 DYN_DEBUG("uidx %d", ti->uidx);
617 if (ti->uidx != 0) {
618 if (ti->tlvs == NULL)
619 return (EINVAL);
620 /* Search ntlv in the buffer provided by user */
621 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
622 IPFW_TLV_STATE_NAME);
623 if (ntlv == NULL)
624 return (EINVAL);
625 name = ntlv->name;
626 } else
627 name = default_state_name;
628 /*
629 * Search named object with corresponding name.
630 * Since states objects are global - ignore the set value
631 * and use zero instead.
632 */
633 *pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0,
634 IPFW_TLV_STATE_NAME, name);
635 /*
636 * We always return success here.
637 * The caller will check *pno and mark object as unresolved,
638 * then it will automatically create "default" object.
639 */
640 return (0);
641 }
642
643 static struct named_object *
644 dyn_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
645 {
646
647 DYN_DEBUG("kidx %d", idx);
648 return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx));
649 }
650
651 static int
652 dyn_create(struct ip_fw_chain *ch, struct tid_info *ti,
653 uint16_t *pkidx)
654 {
655 struct namedobj_instance *ni;
656 struct dyn_state_obj *obj;
657 struct named_object *no;
658 ipfw_obj_ntlv *ntlv;
659 char *name;
660
661 DYN_DEBUG("uidx %d", ti->uidx);
662 if (ti->uidx != 0) {
663 if (ti->tlvs == NULL)
664 return (EINVAL);
665 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
666 IPFW_TLV_STATE_NAME);
667 if (ntlv == NULL)
668 return (EINVAL);
669 name = ntlv->name;
670 } else
671 name = default_state_name;
672
673 ni = CHAIN_TO_SRV(ch);
674 obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO);
675 obj->no.name = obj->name;
676 obj->no.etlv = IPFW_TLV_STATE_NAME;
677 strlcpy(obj->name, name, sizeof(obj->name));
678
679 IPFW_UH_WLOCK(ch);
680 no = ipfw_objhash_lookup_name_type(ni, 0,
681 IPFW_TLV_STATE_NAME, name);
682 if (no != NULL) {
683 /*
684 * Object is already created.
685 * Just return its kidx and bump refcount.
686 */
687 *pkidx = no->kidx;
688 no->refcnt++;
689 IPFW_UH_WUNLOCK(ch);
690 free(obj, M_IPFW);
691 DYN_DEBUG("\tfound kidx %d", *pkidx);
692 return (0);
693 }
694 if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) {
695 DYN_DEBUG("\talloc_idx failed for %s", name);
696 IPFW_UH_WUNLOCK(ch);
697 free(obj, M_IPFW);
698 return (ENOSPC);
699 }
700 ipfw_objhash_add(ni, &obj->no);
701 SRV_OBJECT(ch, obj->no.kidx) = obj;
702 obj->no.refcnt++;
703 *pkidx = obj->no.kidx;
704 IPFW_UH_WUNLOCK(ch);
705 DYN_DEBUG("\tcreated kidx %d", *pkidx);
706 return (0);
707 }
708
709 static void
710 dyn_destroy(struct ip_fw_chain *ch, struct named_object *no)
711 {
712 struct dyn_state_obj *obj;
713
714 IPFW_UH_WLOCK_ASSERT(ch);
715
716 KASSERT(no->etlv == IPFW_TLV_STATE_NAME,
717 ("%s: wrong object type %u", __func__, no->etlv));
718 KASSERT(no->refcnt == 1,
719 ("Destroying object '%s' (type %u, idx %u) with refcnt %u",
720 no->name, no->etlv, no->kidx, no->refcnt));
721 DYN_DEBUG("kidx %d", no->kidx);
722 obj = SRV_OBJECT(ch, no->kidx);
723 SRV_OBJECT(ch, no->kidx) = NULL;
724 ipfw_objhash_del(CHAIN_TO_SRV(ch), no);
725 ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx);
726
727 free(obj, M_IPFW);
728 }
729
730 static struct opcode_obj_rewrite dyn_opcodes[] = {
731 {
732 O_KEEP_STATE, IPFW_TLV_STATE_NAME,
733 dyn_classify, dyn_update,
734 dyn_findbyname, dyn_findbykidx,
735 dyn_create, dyn_destroy
736 },
737 {
738 O_CHECK_STATE, IPFW_TLV_STATE_NAME,
739 dyn_classify, dyn_update,
740 dyn_findbyname, dyn_findbykidx,
741 dyn_create, dyn_destroy
742 },
743 {
744 O_PROBE_STATE, IPFW_TLV_STATE_NAME,
745 dyn_classify, dyn_update,
746 dyn_findbyname, dyn_findbykidx,
747 dyn_create, dyn_destroy
748 },
749 {
750 O_LIMIT, IPFW_TLV_STATE_NAME,
751 dyn_classify, dyn_update,
752 dyn_findbyname, dyn_findbykidx,
753 dyn_create, dyn_destroy
754 },
755 };
756
757 /*
758 * IMPORTANT: the hash function for dynamic rules must be commutative
759 * in source and destination (ip,port), because rules are bidirectional
760 * and we want to find both in the same bucket.
761 */
762 #ifndef IPFIREWALL_JENKINSHASH
763 static __inline uint32_t
764 hash_packet(const struct ipfw_flow_id *id)
765 {
766 uint32_t i;
767
768 #ifdef INET6
769 if (IS_IP6_FLOW_ID(id))
770 i = ntohl((id->dst_ip6.__u6_addr.__u6_addr32[2]) ^
771 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^
772 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^
773 (id->src_ip6.__u6_addr.__u6_addr32[3]));
774 else
775 #endif /* INET6 */
776 i = (id->dst_ip) ^ (id->src_ip);
777 i ^= (id->dst_port) ^ (id->src_port);
778 return (i);
779 }
780
781 static __inline uint32_t
782 hash_parent(const struct ipfw_flow_id *id, const void *rule)
783 {
784
785 return (hash_packet(id) ^ ((uintptr_t)rule));
786 }
787
788 #else /* IPFIREWALL_JENKINSHASH */
789
790 VNET_DEFINE_STATIC(uint32_t, dyn_hashseed);
791 #define V_dyn_hashseed VNET(dyn_hashseed)
792
793 static __inline int
794 addrcmp4(const struct ipfw_flow_id *id)
795 {
796
797 if (id->src_ip < id->dst_ip)
798 return (0);
799 if (id->src_ip > id->dst_ip)
800 return (1);
801 if (id->src_port <= id->dst_port)
802 return (0);
803 return (1);
804 }
805
806 #ifdef INET6
807 static __inline int
808 addrcmp6(const struct ipfw_flow_id *id)
809 {
810 int ret;
811
812 ret = memcmp(&id->src_ip6, &id->dst_ip6, sizeof(struct in6_addr));
813 if (ret < 0)
814 return (0);
815 if (ret > 0)
816 return (1);
817 if (id->src_port <= id->dst_port)
818 return (0);
819 return (1);
820 }
821
822 static __inline uint32_t
823 hash_packet6(const struct ipfw_flow_id *id)
824 {
825 struct tuple6 {
826 struct in6_addr addr[2];
827 uint16_t port[2];
828 } t6;
829
830 if (addrcmp6(id) == 0) {
831 t6.addr[0] = id->src_ip6;
832 t6.addr[1] = id->dst_ip6;
833 t6.port[0] = id->src_port;
834 t6.port[1] = id->dst_port;
835 } else {
836 t6.addr[0] = id->dst_ip6;
837 t6.addr[1] = id->src_ip6;
838 t6.port[0] = id->dst_port;
839 t6.port[1] = id->src_port;
840 }
841 return (jenkins_hash32((const uint32_t *)&t6,
842 sizeof(t6) / sizeof(uint32_t), V_dyn_hashseed));
843 }
844 #endif
845
846 static __inline uint32_t
847 hash_packet(const struct ipfw_flow_id *id)
848 {
849 struct tuple4 {
850 in_addr_t addr[2];
851 uint16_t port[2];
852 } t4;
853
854 if (IS_IP4_FLOW_ID(id)) {
855 /* All fields are in host byte order */
856 if (addrcmp4(id) == 0) {
857 t4.addr[0] = id->src_ip;
858 t4.addr[1] = id->dst_ip;
859 t4.port[0] = id->src_port;
860 t4.port[1] = id->dst_port;
861 } else {
862 t4.addr[0] = id->dst_ip;
863 t4.addr[1] = id->src_ip;
864 t4.port[0] = id->dst_port;
865 t4.port[1] = id->src_port;
866 }
867 return (jenkins_hash32((const uint32_t *)&t4,
868 sizeof(t4) / sizeof(uint32_t), V_dyn_hashseed));
869 } else
870 #ifdef INET6
871 if (IS_IP6_FLOW_ID(id))
872 return (hash_packet6(id));
873 #endif
874 return (0);
875 }
876
877 static __inline uint32_t
878 hash_parent(const struct ipfw_flow_id *id, const void *rule)
879 {
880
881 return (jenkins_hash32((const uint32_t *)&rule,
882 sizeof(rule) / sizeof(uint32_t), hash_packet(id)));
883 }
884 #endif /* IPFIREWALL_JENKINSHASH */
885
886 /*
887 * Print customizable flow id description via log(9) facility.
888 */
889 static void
890 print_dyn_rule_flags(const struct ipfw_flow_id *id, int dyn_type,
891 int log_flags, char *prefix, char *postfix)
892 {
893 struct in_addr da;
894 #ifdef INET6
895 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
896 #else
897 char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN];
898 #endif
899
900 #ifdef INET6
901 if (IS_IP6_FLOW_ID(id)) {
902 ip6_sprintf(src, &id->src_ip6);
903 ip6_sprintf(dst, &id->dst_ip6);
904 } else
905 #endif
906 {
907 da.s_addr = htonl(id->src_ip);
908 inet_ntop(AF_INET, &da, src, sizeof(src));
909 da.s_addr = htonl(id->dst_ip);
910 inet_ntop(AF_INET, &da, dst, sizeof(dst));
911 }
912 log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n",
913 prefix, dyn_type, src, id->src_port, dst,
914 id->dst_port, V_dyn_count, postfix);
915 }
916
917 #define print_dyn_rule(id, dtype, prefix, postfix) \
918 print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix)
919
920 #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
921 #define TIME_LE(a,b) ((int)((a)-(b)) < 0)
922 #define _SEQ_GE(a,b) ((int)((a)-(b)) >= 0)
923 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
924 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
925 #define TCP_FLAGS (TH_FLAGS | (TH_FLAGS << 8))
926 #define ACK_FWD 0x00010000 /* fwd ack seen */
927 #define ACK_REV 0x00020000 /* rev ack seen */
928 #define ACK_BOTH (ACK_FWD | ACK_REV)
929
930 static uint32_t
931 dyn_update_tcp_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
932 const struct tcphdr *tcp, int dir)
933 {
934 uint32_t ack, expire;
935 uint32_t state, old;
936 uint8_t th_flags;
937
938 expire = data->expire;
939 old = state = data->state;
940 th_flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST);
941 state |= (dir == MATCH_FORWARD) ? th_flags: (th_flags << 8);
942 switch (state & TCP_FLAGS) {
943 case TH_SYN: /* opening */
944 expire = time_uptime + V_dyn_syn_lifetime;
945 break;
946
947 case BOTH_SYN: /* move to established */
948 case BOTH_SYN | TH_FIN: /* one side tries to close */
949 case BOTH_SYN | (TH_FIN << 8):
950 if (tcp == NULL)
951 break;
952 ack = ntohl(tcp->th_ack);
953 if (dir == MATCH_FORWARD) {
954 if (data->ack_fwd == 0 ||
955 _SEQ_GE(ack, data->ack_fwd)) {
956 state |= ACK_FWD;
957 if (data->ack_fwd != ack)
958 ck_pr_store_32(&data->ack_fwd, ack);
959 }
960 } else {
961 if (data->ack_rev == 0 ||
962 _SEQ_GE(ack, data->ack_rev)) {
963 state |= ACK_REV;
964 if (data->ack_rev != ack)
965 ck_pr_store_32(&data->ack_rev, ack);
966 }
967 }
968 if ((state & ACK_BOTH) == ACK_BOTH) {
969 /*
970 * Set expire time to V_dyn_ack_lifetime only if
971 * we got ACKs for both directions.
972 * We use XOR here to avoid possible state
973 * overwriting in concurrent thread.
974 */
975 expire = time_uptime + V_dyn_ack_lifetime;
976 ck_pr_xor_32(&data->state, ACK_BOTH);
977 } else if ((data->state & ACK_BOTH) != (state & ACK_BOTH))
978 ck_pr_or_32(&data->state, state & ACK_BOTH);
979 break;
980
981 case BOTH_SYN | BOTH_FIN: /* both sides closed */
982 if (V_dyn_fin_lifetime >= V_dyn_keepalive_period)
983 V_dyn_fin_lifetime = V_dyn_keepalive_period - 1;
984 expire = time_uptime + V_dyn_fin_lifetime;
985 break;
986
987 default:
988 if (V_dyn_keepalive != 0 &&
989 V_dyn_rst_lifetime >= V_dyn_keepalive_period)
990 V_dyn_rst_lifetime = V_dyn_keepalive_period - 1;
991 expire = time_uptime + V_dyn_rst_lifetime;
992 }
993 /* Save TCP state if it was changed */
994 if ((state & TCP_FLAGS) != (old & TCP_FLAGS))
995 ck_pr_or_32(&data->state, state & TCP_FLAGS);
996 return (expire);
997 }
998
999 /*
1000 * Update ULP specific state.
1001 * For TCP we keep sequence numbers and flags. For other protocols
1002 * currently we update only expire time. Packets and bytes counters
1003 * are also updated here.
1004 */
1005 static void
1006 dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
1007 const void *ulp, int pktlen, int dir)
1008 {
1009 uint32_t expire;
1010
1011 /* NOTE: we are in critical section here. */
1012 switch (pkt->proto) {
1013 case IPPROTO_UDP:
1014 case IPPROTO_UDPLITE:
1015 expire = time_uptime + V_dyn_udp_lifetime;
1016 break;
1017 case IPPROTO_TCP:
1018 expire = dyn_update_tcp_state(data, pkt, ulp, dir);
1019 break;
1020 default:
1021 expire = time_uptime + V_dyn_short_lifetime;
1022 }
1023 /*
1024 * Expiration timer has the per-second granularity, no need to update
1025 * it every time when state is matched.
1026 */
1027 if (data->expire != expire)
1028 ck_pr_store_32(&data->expire, expire);
1029
1030 if (dir == MATCH_FORWARD)
1031 DYN_COUNTER_INC(data, fwd, pktlen);
1032 else
1033 DYN_COUNTER_INC(data, rev, pktlen);
1034 }
1035
1036 /*
1037 * Lookup IPv4 state.
1038 * Must be called in critical section.
1039 */
1040 struct dyn_ipv4_state *
1041 dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp,
1042 struct ipfw_dyn_info *info, int pktlen)
1043 {
1044 struct dyn_ipv4_state *s;
1045 uint32_t version, bucket;
1046
1047 bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
1048 info->version = DYN_BUCKET_VERSION(bucket, ipv4_add);
1049 restart:
1050 version = DYN_BUCKET_VERSION(bucket, ipv4_del);
1051 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
1052 DYNSTATE_PROTECT(s);
1053 if (version != DYN_BUCKET_VERSION(bucket, ipv4_del))
1054 goto restart;
1055 if (s->proto != pkt->proto)
1056 continue;
1057 if (info->kidx != 0 && s->kidx != info->kidx)
1058 continue;
1059 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1060 s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1061 info->direction = MATCH_FORWARD;
1062 break;
1063 }
1064 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1065 s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
1066 info->direction = MATCH_REVERSE;
1067 break;
1068 }
1069 }
1070
1071 if (s != NULL)
1072 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
1073 info->direction);
1074 return (s);
1075 }
1076
1077 /*
1078 * Lookup IPv4 state.
1079 * Simplifed version is used to check that matching state doesn't exist.
1080 */
1081 static int
1082 dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt,
1083 const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
1084 {
1085 struct dyn_ipv4_state *s;
1086 int dir;
1087
1088 dir = MATCH_NONE;
1089 DYN_BUCKET_ASSERT(bucket);
1090 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
1091 if (s->proto != pkt->proto ||
1092 s->kidx != kidx)
1093 continue;
1094 if (s->sport == pkt->src_port &&
1095 s->dport == pkt->dst_port &&
1096 s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1097 dir = MATCH_FORWARD;
1098 break;
1099 }
1100 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1101 s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
1102 dir = MATCH_REVERSE;
1103 break;
1104 }
1105 }
1106 if (s != NULL)
1107 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
1108 return (s != NULL);
1109 }
1110
1111 struct dyn_ipv4_state *
1112 dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule,
1113 uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
1114 {
1115 struct dyn_ipv4_state *s;
1116 uint32_t version, bucket;
1117
1118 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1119 restart:
1120 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del);
1121 CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
1122 DYNSTATE_PROTECT(s);
1123 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del))
1124 goto restart;
1125 /*
1126 * NOTE: we do not need to check kidx, because parent rule
1127 * can not create states with different kidx.
1128 * And parent rule always created for forward direction.
1129 */
1130 if (s->limit->parent == rule &&
1131 s->limit->ruleid == ruleid &&
1132 s->limit->rulenum == rulenum &&
1133 s->proto == pkt->proto &&
1134 s->sport == pkt->src_port &&
1135 s->dport == pkt->dst_port &&
1136 s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1137 if (s->limit->expire != time_uptime +
1138 V_dyn_short_lifetime)
1139 ck_pr_store_32(&s->limit->expire,
1140 time_uptime + V_dyn_short_lifetime);
1141 break;
1142 }
1143 }
1144 return (s);
1145 }
1146
1147 static struct dyn_ipv4_state *
1148 dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt,
1149 const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
1150 {
1151 struct dyn_ipv4_state *s;
1152
1153 DYN_BUCKET_ASSERT(bucket);
1154 CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
1155 if (s->limit->parent == rule &&
1156 s->limit->ruleid == ruleid &&
1157 s->limit->rulenum == rulenum &&
1158 s->proto == pkt->proto &&
1159 s->sport == pkt->src_port &&
1160 s->dport == pkt->dst_port &&
1161 s->src == pkt->src_ip && s->dst == pkt->dst_ip)
1162 break;
1163 }
1164 return (s);
1165 }
1166
1167 #ifdef INET6
1168 static uint32_t
1169 dyn_getscopeid(const struct ip_fw_args *args)
1170 {
1171
1172 /*
1173 * If source or destination address is an scopeid address, we need
1174 * determine the scope zone id to resolve address scope ambiguity.
1175 */
1176 if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) ||
1177 IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6))
1178 return (in6_getscopezone(args->ifp, IPV6_ADDR_SCOPE_LINKLOCAL));
1179
1180 return (0);
1181 }
1182
1183 /*
1184 * Lookup IPv6 state.
1185 * Must be called in critical section.
1186 */
1187 static struct dyn_ipv6_state *
1188 dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1189 const void *ulp, struct ipfw_dyn_info *info, int pktlen)
1190 {
1191 struct dyn_ipv6_state *s;
1192 uint32_t version, bucket;
1193
1194 bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
1195 info->version = DYN_BUCKET_VERSION(bucket, ipv6_add);
1196 restart:
1197 version = DYN_BUCKET_VERSION(bucket, ipv6_del);
1198 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
1199 DYNSTATE_PROTECT(s);
1200 if (version != DYN_BUCKET_VERSION(bucket, ipv6_del))
1201 goto restart;
1202 if (s->proto != pkt->proto || s->zoneid != zoneid)
1203 continue;
1204 if (info->kidx != 0 && s->kidx != info->kidx)
1205 continue;
1206 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1207 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1208 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1209 info->direction = MATCH_FORWARD;
1210 break;
1211 }
1212 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1213 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
1214 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
1215 info->direction = MATCH_REVERSE;
1216 break;
1217 }
1218 }
1219 if (s != NULL)
1220 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
1221 info->direction);
1222 return (s);
1223 }
1224
1225 /*
1226 * Lookup IPv6 state.
1227 * Simplifed version is used to check that matching state doesn't exist.
1228 */
1229 static int
1230 dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1231 const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
1232 {
1233 struct dyn_ipv6_state *s;
1234 int dir;
1235
1236 dir = MATCH_NONE;
1237 DYN_BUCKET_ASSERT(bucket);
1238 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
1239 if (s->proto != pkt->proto || s->kidx != kidx ||
1240 s->zoneid != zoneid)
1241 continue;
1242 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1243 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1244 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1245 dir = MATCH_FORWARD;
1246 break;
1247 }
1248 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1249 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
1250 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
1251 dir = MATCH_REVERSE;
1252 break;
1253 }
1254 }
1255 if (s != NULL)
1256 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
1257 return (s != NULL);
1258 }
1259
1260 static struct dyn_ipv6_state *
1261 dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1262 const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
1263 {
1264 struct dyn_ipv6_state *s;
1265 uint32_t version, bucket;
1266
1267 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1268 restart:
1269 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del);
1270 CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
1271 DYNSTATE_PROTECT(s);
1272 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del))
1273 goto restart;
1274 /*
1275 * NOTE: we do not need to check kidx, because parent rule
1276 * can not create states with different kidx.
1277 * Also parent rule always created for forward direction.
1278 */
1279 if (s->limit->parent == rule &&
1280 s->limit->ruleid == ruleid &&
1281 s->limit->rulenum == rulenum &&
1282 s->proto == pkt->proto &&
1283 s->sport == pkt->src_port &&
1284 s->dport == pkt->dst_port && s->zoneid == zoneid &&
1285 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1286 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1287 if (s->limit->expire != time_uptime +
1288 V_dyn_short_lifetime)
1289 ck_pr_store_32(&s->limit->expire,
1290 time_uptime + V_dyn_short_lifetime);
1291 break;
1292 }
1293 }
1294 return (s);
1295 }
1296
1297 static struct dyn_ipv6_state *
1298 dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1299 const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
1300 {
1301 struct dyn_ipv6_state *s;
1302
1303 DYN_BUCKET_ASSERT(bucket);
1304 CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
1305 if (s->limit->parent == rule &&
1306 s->limit->ruleid == ruleid &&
1307 s->limit->rulenum == rulenum &&
1308 s->proto == pkt->proto &&
1309 s->sport == pkt->src_port &&
1310 s->dport == pkt->dst_port && s->zoneid == zoneid &&
1311 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1312 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6))
1313 break;
1314 }
1315 return (s);
1316 }
1317
1318 #endif /* INET6 */
1319
1320 /*
1321 * Lookup dynamic state.
1322 * pkt - filled by ipfw_chk() ipfw_flow_id;
1323 * ulp - determined by ipfw_chk() upper level protocol header;
1324 * dyn_info - info about matched state to return back;
1325 * Returns pointer to state's parent rule and dyn_info. If there is
1326 * no state, NULL is returned.
1327 * On match ipfw_dyn_lookup() updates state's counters.
1328 */
1329 struct ip_fw *
1330 ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp,
1331 int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info)
1332 {
1333 struct dyn_data *data;
1334 struct ip_fw *rule;
1335
1336 IPFW_RLOCK_ASSERT(&V_layer3_chain);
1337
1338 data = NULL;
1339 rule = NULL;
1340 info->kidx = cmd->arg1;
1341 info->direction = MATCH_NONE;
1342 info->hashval = hash_packet(&args->f_id);
1343
1344 DYNSTATE_CRITICAL_ENTER();
1345 if (IS_IP4_FLOW_ID(&args->f_id)) {
1346 struct dyn_ipv4_state *s;
1347
1348 s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen);
1349 if (s != NULL) {
1350 /*
1351 * Dynamic states are created using the same 5-tuple,
1352 * so it is assumed, that parent rule for O_LIMIT
1353 * state has the same address family.
1354 */
1355 data = s->data;
1356 if (s->type == O_LIMIT) {
1357 s = data->parent;
1358 rule = s->limit->parent;
1359 } else
1360 rule = data->parent;
1361 }
1362 }
1363 #ifdef INET6
1364 else if (IS_IP6_FLOW_ID(&args->f_id)) {
1365 struct dyn_ipv6_state *s;
1366
1367 s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args),
1368 ulp, info, pktlen);
1369 if (s != NULL) {
1370 data = s->data;
1371 if (s->type == O_LIMIT) {
1372 s = data->parent;
1373 rule = s->limit->parent;
1374 } else
1375 rule = data->parent;
1376 }
1377 }
1378 #endif
1379 if (data != NULL) {
1380 /*
1381 * If cached chain id is the same, we can avoid rule index
1382 * lookup. Otherwise do lookup and update chain_id and f_pos.
1383 * It is safe even if there is concurrent thread that want
1384 * update the same state, because chain->id can be changed
1385 * only under IPFW_WLOCK().
1386 */
1387 if (data->chain_id != V_layer3_chain.id) {
1388 data->f_pos = ipfw_find_rule(&V_layer3_chain,
1389 data->rulenum, data->ruleid);
1390 /*
1391 * Check that found state has not orphaned.
1392 * When chain->id being changed the parent
1393 * rule can be deleted. If found rule doesn't
1394 * match the parent pointer, consider this
1395 * result as MATCH_NONE and return NULL.
1396 *
1397 * This will lead to creation of new similar state
1398 * that will be added into head of this bucket.
1399 * And the state that we currently have matched
1400 * should be deleted by dyn_expire_states().
1401 *
1402 * In case when dyn_keep_states is enabled, return
1403 * pointer to deleted rule and f_pos value
1404 * corresponding to penultimate rule.
1405 * When we have enabled V_dyn_keep_states, states
1406 * that become orphaned will get the DYN_REFERENCED
1407 * flag and rule will keep around. So we can return
1408 * it. But since it is not in the rules map, we need
1409 * return such f_pos value, so after the state
1410 * handling if the search will continue, the next rule
1411 * will be the last one - the default rule.
1412 */
1413 if (V_layer3_chain.map[data->f_pos] == rule) {
1414 data->chain_id = V_layer3_chain.id;
1415 info->f_pos = data->f_pos;
1416 } else if (V_dyn_keep_states != 0) {
1417 /*
1418 * The original rule pointer is still usable.
1419 * So, we return it, but f_pos need to be
1420 * changed to point to the penultimate rule.
1421 */
1422 MPASS(V_layer3_chain.n_rules > 1);
1423 data->chain_id = V_layer3_chain.id;
1424 data->f_pos = V_layer3_chain.n_rules - 2;
1425 info->f_pos = data->f_pos;
1426 } else {
1427 rule = NULL;
1428 info->direction = MATCH_NONE;
1429 DYN_DEBUG("rule %p [%u, %u] is considered "
1430 "invalid in data %p", rule, data->ruleid,
1431 data->rulenum, data);
1432 /* info->f_pos doesn't matter here. */
1433 }
1434 } else
1435 info->f_pos = data->f_pos;
1436 }
1437 DYNSTATE_CRITICAL_EXIT();
1438 #if 0
1439 /*
1440 * Return MATCH_NONE if parent rule is in disabled set.
1441 * This will lead to creation of new similar state that
1442 * will be added into head of this bucket.
1443 *
1444 * XXXAE: we need to be able update state's set when parent
1445 * rule set is changed.
1446 */
1447 if (rule != NULL && (V_set_disable & (1 << rule->set))) {
1448 rule = NULL;
1449 info->direction = MATCH_NONE;
1450 }
1451 #endif
1452 return (rule);
1453 }
1454
1455 static struct dyn_parent *
1456 dyn_alloc_parent(void *parent, uint32_t ruleid, uint16_t rulenum,
1457 uint32_t hashval)
1458 {
1459 struct dyn_parent *limit;
1460
1461 limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO);
1462 if (limit == NULL) {
1463 if (last_log != time_uptime) {
1464 last_log = time_uptime;
1465 log(LOG_DEBUG,
1466 "ipfw: Cannot allocate parent dynamic state, "
1467 "consider increasing "
1468 "net.inet.ip.fw.dyn_parent_max\n");
1469 }
1470 return (NULL);
1471 }
1472
1473 limit->parent = parent;
1474 limit->ruleid = ruleid;
1475 limit->rulenum = rulenum;
1476 limit->hashval = hashval;
1477 limit->expire = time_uptime + V_dyn_short_lifetime;
1478 return (limit);
1479 }
1480
1481 static struct dyn_data *
1482 dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint16_t rulenum,
1483 const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
1484 uint32_t hashval, uint16_t fibnum)
1485 {
1486 struct dyn_data *data;
1487
1488 data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO);
1489 if (data == NULL) {
1490 if (last_log != time_uptime) {
1491 last_log = time_uptime;
1492 log(LOG_DEBUG,
1493 "ipfw: Cannot allocate dynamic state, "
1494 "consider increasing net.inet.ip.fw.dyn_max\n");
1495 }
1496 return (NULL);
1497 }
1498
1499 data->parent = parent;
1500 data->ruleid = ruleid;
1501 data->rulenum = rulenum;
1502 data->fibnum = fibnum;
1503 data->hashval = hashval;
1504 data->expire = time_uptime + V_dyn_syn_lifetime;
1505 dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD);
1506 return (data);
1507 }
1508
1509 static struct dyn_ipv4_state *
1510 dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint16_t kidx,
1511 uint8_t type)
1512 {
1513 struct dyn_ipv4_state *s;
1514
1515 s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO);
1516 if (s == NULL)
1517 return (NULL);
1518
1519 s->type = type;
1520 s->kidx = kidx;
1521 s->proto = pkt->proto;
1522 s->sport = pkt->src_port;
1523 s->dport = pkt->dst_port;
1524 s->src = pkt->src_ip;
1525 s->dst = pkt->dst_ip;
1526 return (s);
1527 }
1528
1529 /*
1530 * Add IPv4 parent state.
1531 * Returns pointer to parent state. When it is not NULL we are in
1532 * critical section and pointer protected by hazard pointer.
1533 * When some error occurs, it returns NULL and exit from critical section
1534 * is not needed.
1535 */
1536 static struct dyn_ipv4_state *
1537 dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
1538 const struct ipfw_flow_id *pkt, uint32_t hashval, uint32_t version,
1539 uint16_t kidx)
1540 {
1541 struct dyn_ipv4_state *s;
1542 struct dyn_parent *limit;
1543 uint32_t bucket;
1544
1545 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1546 DYN_BUCKET_LOCK(bucket);
1547 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) {
1548 /*
1549 * Bucket version has been changed since last lookup,
1550 * do lookup again to be sure that state does not exist.
1551 */
1552 s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid,
1553 rulenum, bucket);
1554 if (s != NULL) {
1555 /*
1556 * Simultaneous thread has already created this
1557 * state. Just return it.
1558 */
1559 DYNSTATE_CRITICAL_ENTER();
1560 DYNSTATE_PROTECT(s);
1561 DYN_BUCKET_UNLOCK(bucket);
1562 return (s);
1563 }
1564 }
1565
1566 limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval);
1567 if (limit == NULL) {
1568 DYN_BUCKET_UNLOCK(bucket);
1569 return (NULL);
1570 }
1571
1572 s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT);
1573 if (s == NULL) {
1574 DYN_BUCKET_UNLOCK(bucket);
1575 uma_zfree(V_dyn_parent_zone, limit);
1576 return (NULL);
1577 }
1578
1579 s->limit = limit;
1580 CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry);
1581 DYN_COUNT_INC(dyn_parent_count);
1582 DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add);
1583 DYNSTATE_CRITICAL_ENTER();
1584 DYNSTATE_PROTECT(s);
1585 DYN_BUCKET_UNLOCK(bucket);
1586 return (s);
1587 }
1588
1589 static int
1590 dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint16_t rulenum,
1591 const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
1592 uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum,
1593 uint16_t kidx, uint8_t type)
1594 {
1595 struct dyn_ipv4_state *s;
1596 void *data;
1597 uint32_t bucket;
1598
1599 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1600 DYN_BUCKET_LOCK(bucket);
1601 if (info->direction == MATCH_UNKNOWN ||
1602 info->kidx != kidx ||
1603 info->hashval != hashval ||
1604 info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) {
1605 /*
1606 * Bucket version has been changed since last lookup,
1607 * do lookup again to be sure that state does not exist.
1608 */
1609 if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen,
1610 bucket, kidx) != 0) {
1611 DYN_BUCKET_UNLOCK(bucket);
1612 return (EEXIST);
1613 }
1614 }
1615
1616 data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp,
1617 pktlen, hashval, fibnum);
1618 if (data == NULL) {
1619 DYN_BUCKET_UNLOCK(bucket);
1620 return (ENOMEM);
1621 }
1622
1623 s = dyn_alloc_ipv4_state(pkt, kidx, type);
1624 if (s == NULL) {
1625 DYN_BUCKET_UNLOCK(bucket);
1626 uma_zfree(V_dyn_data_zone, data);
1627 return (ENOMEM);
1628 }
1629
1630 s->data = data;
1631 CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry);
1632 DYN_COUNT_INC(dyn_count);
1633 DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add);
1634 DYN_BUCKET_UNLOCK(bucket);
1635 return (0);
1636 }
1637
1638 #ifdef INET6
1639 static struct dyn_ipv6_state *
1640 dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1641 uint16_t kidx, uint8_t type)
1642 {
1643 struct dyn_ipv6_state *s;
1644
1645 s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO);
1646 if (s == NULL)
1647 return (NULL);
1648
1649 s->type = type;
1650 s->kidx = kidx;
1651 s->zoneid = zoneid;
1652 s->proto = pkt->proto;
1653 s->sport = pkt->src_port;
1654 s->dport = pkt->dst_port;
1655 s->src = pkt->src_ip6;
1656 s->dst = pkt->dst_ip6;
1657 return (s);
1658 }
1659
1660 /*
1661 * Add IPv6 parent state.
1662 * Returns pointer to parent state. When it is not NULL we are in
1663 * critical section and pointer protected by hazard pointer.
1664 * When some error occurs, it return NULL and exit from critical section
1665 * is not needed.
1666 */
1667 static struct dyn_ipv6_state *
1668 dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
1669 const struct ipfw_flow_id *pkt, uint32_t zoneid, uint32_t hashval,
1670 uint32_t version, uint16_t kidx)
1671 {
1672 struct dyn_ipv6_state *s;
1673 struct dyn_parent *limit;
1674 uint32_t bucket;
1675
1676 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1677 DYN_BUCKET_LOCK(bucket);
1678 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) {
1679 /*
1680 * Bucket version has been changed since last lookup,
1681 * do lookup again to be sure that state does not exist.
1682 */
1683 s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid,
1684 rulenum, bucket);
1685 if (s != NULL) {
1686 /*
1687 * Simultaneous thread has already created this
1688 * state. Just return it.
1689 */
1690 DYNSTATE_CRITICAL_ENTER();
1691 DYNSTATE_PROTECT(s);
1692 DYN_BUCKET_UNLOCK(bucket);
1693 return (s);
1694 }
1695 }
1696
1697 limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval);
1698 if (limit == NULL) {
1699 DYN_BUCKET_UNLOCK(bucket);
1700 return (NULL);
1701 }
1702
1703 s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT);
1704 if (s == NULL) {
1705 DYN_BUCKET_UNLOCK(bucket);
1706 uma_zfree(V_dyn_parent_zone, limit);
1707 return (NULL);
1708 }
1709
1710 s->limit = limit;
1711 CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry);
1712 DYN_COUNT_INC(dyn_parent_count);
1713 DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add);
1714 DYNSTATE_CRITICAL_ENTER();
1715 DYNSTATE_PROTECT(s);
1716 DYN_BUCKET_UNLOCK(bucket);
1717 return (s);
1718 }
1719
1720 static int
1721 dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint16_t rulenum,
1722 const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp,
1723 int pktlen, uint32_t hashval, struct ipfw_dyn_info *info,
1724 uint16_t fibnum, uint16_t kidx, uint8_t type)
1725 {
1726 struct dyn_ipv6_state *s;
1727 struct dyn_data *data;
1728 uint32_t bucket;
1729
1730 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1731 DYN_BUCKET_LOCK(bucket);
1732 if (info->direction == MATCH_UNKNOWN ||
1733 info->kidx != kidx ||
1734 info->hashval != hashval ||
1735 info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) {
1736 /*
1737 * Bucket version has been changed since last lookup,
1738 * do lookup again to be sure that state does not exist.
1739 */
1740 if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen,
1741 bucket, kidx) != 0) {
1742 DYN_BUCKET_UNLOCK(bucket);
1743 return (EEXIST);
1744 }
1745 }
1746
1747 data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp,
1748 pktlen, hashval, fibnum);
1749 if (data == NULL) {
1750 DYN_BUCKET_UNLOCK(bucket);
1751 return (ENOMEM);
1752 }
1753
1754 s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type);
1755 if (s == NULL) {
1756 DYN_BUCKET_UNLOCK(bucket);
1757 uma_zfree(V_dyn_data_zone, data);
1758 return (ENOMEM);
1759 }
1760
1761 s->data = data;
1762 CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry);
1763 DYN_COUNT_INC(dyn_count);
1764 DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add);
1765 DYN_BUCKET_UNLOCK(bucket);
1766 return (0);
1767 }
1768 #endif /* INET6 */
1769
1770 static void *
1771 dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1772 struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint16_t kidx)
1773 {
1774 char sbuf[24];
1775 struct dyn_parent *p;
1776 void *ret;
1777 uint32_t bucket, version;
1778
1779 p = NULL;
1780 ret = NULL;
1781 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1782 DYNSTATE_CRITICAL_ENTER();
1783 if (IS_IP4_FLOW_ID(pkt)) {
1784 struct dyn_ipv4_state *s;
1785
1786 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add);
1787 s = dyn_lookup_ipv4_parent(pkt, rule, rule->id,
1788 rule->rulenum, bucket);
1789 if (s == NULL) {
1790 /*
1791 * Exit from critical section because dyn_add_parent()
1792 * will acquire bucket lock.
1793 */
1794 DYNSTATE_CRITICAL_EXIT();
1795
1796 s = dyn_add_ipv4_parent(rule, rule->id,
1797 rule->rulenum, pkt, hashval, version, kidx);
1798 if (s == NULL)
1799 return (NULL);
1800 /* Now we are in critical section again. */
1801 }
1802 ret = s;
1803 p = s->limit;
1804 }
1805 #ifdef INET6
1806 else if (IS_IP6_FLOW_ID(pkt)) {
1807 struct dyn_ipv6_state *s;
1808
1809 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add);
1810 s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id,
1811 rule->rulenum, bucket);
1812 if (s == NULL) {
1813 /*
1814 * Exit from critical section because dyn_add_parent()
1815 * can acquire bucket mutex.
1816 */
1817 DYNSTATE_CRITICAL_EXIT();
1818
1819 s = dyn_add_ipv6_parent(rule, rule->id,
1820 rule->rulenum, pkt, zoneid, hashval, version,
1821 kidx);
1822 if (s == NULL)
1823 return (NULL);
1824 /* Now we are in critical section again. */
1825 }
1826 ret = s;
1827 p = s->limit;
1828 }
1829 #endif
1830 else {
1831 DYNSTATE_CRITICAL_EXIT();
1832 return (NULL);
1833 }
1834
1835 /* Check the limit */
1836 if (DPARENT_COUNT(p) >= limit) {
1837 DYNSTATE_CRITICAL_EXIT();
1838 if (V_fw_verbose && last_log != time_uptime) {
1839 last_log = time_uptime;
1840 snprintf(sbuf, sizeof(sbuf), "%u drop session",
1841 rule->rulenum);
1842 print_dyn_rule_flags(pkt, O_LIMIT,
1843 LOG_SECURITY | LOG_DEBUG, sbuf,
1844 "too many entries");
1845 }
1846 return (NULL);
1847 }
1848
1849 /* Take new session into account. */
1850 DPARENT_COUNT_INC(p);
1851 /*
1852 * We must exit from critical section because the following code
1853 * can acquire bucket mutex.
1854 * We rely on the 'count' field. The state will not expire
1855 * until it has some child states, i.e. 'count' field is not zero.
1856 * Return state pointer, it will be used by child states as parent.
1857 */
1858 DYNSTATE_CRITICAL_EXIT();
1859 return (ret);
1860 }
1861
1862 static int
1863 dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1864 uint16_t fibnum, const void *ulp, int pktlen, struct ip_fw *rule,
1865 struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask,
1866 uint16_t kidx, uint8_t type)
1867 {
1868 struct ipfw_flow_id id;
1869 uint32_t hashval, parent_hashval, ruleid, rulenum;
1870 int ret;
1871
1872 MPASS(type == O_LIMIT || type == O_KEEP_STATE);
1873
1874 ruleid = rule->id;
1875 rulenum = rule->rulenum;
1876 if (type == O_LIMIT) {
1877 /* Create masked flow id and calculate bucket */
1878 id.addr_type = pkt->addr_type;
1879 id.proto = pkt->proto;
1880 id.fib = fibnum; /* unused */
1881 id.src_port = (limit_mask & DYN_SRC_PORT) ?
1882 pkt->src_port: 0;
1883 id.dst_port = (limit_mask & DYN_DST_PORT) ?
1884 pkt->dst_port: 0;
1885 if (IS_IP4_FLOW_ID(pkt)) {
1886 id.src_ip = (limit_mask & DYN_SRC_ADDR) ?
1887 pkt->src_ip: 0;
1888 id.dst_ip = (limit_mask & DYN_DST_ADDR) ?
1889 pkt->dst_ip: 0;
1890 }
1891 #ifdef INET6
1892 else if (IS_IP6_FLOW_ID(pkt)) {
1893 if (limit_mask & DYN_SRC_ADDR)
1894 id.src_ip6 = pkt->src_ip6;
1895 else
1896 memset(&id.src_ip6, 0, sizeof(id.src_ip6));
1897 if (limit_mask & DYN_DST_ADDR)
1898 id.dst_ip6 = pkt->dst_ip6;
1899 else
1900 memset(&id.dst_ip6, 0, sizeof(id.dst_ip6));
1901 }
1902 #endif
1903 else
1904 return (EAFNOSUPPORT);
1905
1906 parent_hashval = hash_parent(&id, rule);
1907 rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval,
1908 limit, kidx);
1909 if (rule == NULL) {
1910 #if 0
1911 if (V_fw_verbose && last_log != time_uptime) {
1912 last_log = time_uptime;
1913 snprintf(sbuf, sizeof(sbuf),
1914 "%u drop session", rule->rulenum);
1915 print_dyn_rule_flags(pkt, O_LIMIT,
1916 LOG_SECURITY | LOG_DEBUG, sbuf,
1917 "too many entries");
1918 }
1919 #endif
1920 return (EACCES);
1921 }
1922 /*
1923 * Limit is not reached, create new state.
1924 * Now rule points to parent state.
1925 */
1926 }
1927
1928 hashval = hash_packet(pkt);
1929 if (IS_IP4_FLOW_ID(pkt))
1930 ret = dyn_add_ipv4_state(rule, ruleid, rulenum, pkt,
1931 ulp, pktlen, hashval, info, fibnum, kidx, type);
1932 #ifdef INET6
1933 else if (IS_IP6_FLOW_ID(pkt))
1934 ret = dyn_add_ipv6_state(rule, ruleid, rulenum, pkt,
1935 zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type);
1936 #endif /* INET6 */
1937 else
1938 ret = EAFNOSUPPORT;
1939
1940 if (type == O_LIMIT) {
1941 if (ret != 0) {
1942 /*
1943 * We failed to create child state for O_LIMIT
1944 * opcode. Since we already counted it in the parent,
1945 * we must revert counter back. The 'rule' points to
1946 * parent state, use it to get dyn_parent.
1947 *
1948 * XXXAE: it should be safe to use 'rule' pointer
1949 * without extra lookup, parent state is referenced
1950 * and should not be freed.
1951 */
1952 if (IS_IP4_FLOW_ID(&id))
1953 DPARENT_COUNT_DEC(
1954 ((struct dyn_ipv4_state *)rule)->limit);
1955 #ifdef INET6
1956 else if (IS_IP6_FLOW_ID(&id))
1957 DPARENT_COUNT_DEC(
1958 ((struct dyn_ipv6_state *)rule)->limit);
1959 #endif
1960 }
1961 }
1962 /*
1963 * EEXIST means that simultaneous thread has created this
1964 * state. Consider this as success.
1965 *
1966 * XXXAE: should we invalidate 'info' content here?
1967 */
1968 if (ret == EEXIST)
1969 return (0);
1970 return (ret);
1971 }
1972
1973 /*
1974 * Install dynamic state.
1975 * chain - ipfw's instance;
1976 * rule - the parent rule that installs the state;
1977 * cmd - opcode that installs the state;
1978 * args - ipfw arguments;
1979 * ulp - upper level protocol header;
1980 * pktlen - packet length;
1981 * info - dynamic state lookup info;
1982 * tablearg - tablearg id.
1983 *
1984 * Returns non-zero value (failure) if state is not installed because
1985 * of errors or because session limitations are enforced.
1986 */
1987 int
1988 ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule,
1989 const ipfw_insn_limit *cmd, const struct ip_fw_args *args,
1990 const void *ulp, int pktlen, struct ipfw_dyn_info *info,
1991 uint32_t tablearg)
1992 {
1993 uint32_t limit;
1994 uint16_t limit_mask;
1995
1996 if (cmd->o.opcode == O_LIMIT) {
1997 limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit);
1998 limit_mask = cmd->limit_mask;
1999 } else {
2000 limit = 0;
2001 limit_mask = 0;
2002 }
2003 return (dyn_install_state(&args->f_id,
2004 #ifdef INET6
2005 IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args):
2006 #endif
2007 0, M_GETFIB(args->m), ulp, pktlen, rule, info, limit,
2008 limit_mask, cmd->o.arg1, cmd->o.opcode));
2009 }
2010
2011 /*
2012 * Free safe to remove state entries from expired lists.
2013 */
2014 static void
2015 dyn_free_states(struct ip_fw_chain *chain)
2016 {
2017 struct dyn_ipv4_state *s4, *s4n;
2018 #ifdef INET6
2019 struct dyn_ipv6_state *s6, *s6n;
2020 #endif
2021 int cached_count, i;
2022
2023 /*
2024 * We keep pointers to objects that are in use on each CPU
2025 * in the per-cpu dyn_hp pointer. When object is going to be
2026 * removed, first of it is unlinked from the corresponding
2027 * list. This leads to changing of dyn_bucket_xxx_delver version.
2028 * Unlinked objects is placed into corresponding dyn_expired_xxx
2029 * list. Reader that is going to dereference object pointer checks
2030 * dyn_bucket_xxx_delver version before and after storing pointer
2031 * into dyn_hp. If version is the same, the object is protected
2032 * from freeing and it is safe to dereference. Othervise reader
2033 * tries to iterate list again from the beginning, but this object
2034 * now unlinked and thus will not be accessible.
2035 *
2036 * Copy dyn_hp pointers for each CPU into dyn_hp_cache array.
2037 * It does not matter that some pointer can be changed in
2038 * time while we are copying. We need to check, that objects
2039 * removed in the previous pass are not in use. And if dyn_hp
2040 * pointer does not contain it in the time when we are copying,
2041 * it will not appear there, because it is already unlinked.
2042 * And for new pointers we will not free objects that will be
2043 * unlinked in this pass.
2044 */
2045 cached_count = 0;
2046 CPU_FOREACH(i) {
2047 dyn_hp_cache[cached_count] = DYNSTATE_GET(i);
2048 if (dyn_hp_cache[cached_count] != NULL)
2049 cached_count++;
2050 }
2051
2052 /*
2053 * Free expired states that are safe to free.
2054 * Check each entry from previous pass in the dyn_expired_xxx
2055 * list, if pointer to the object is in the dyn_hp_cache array,
2056 * keep it until next pass. Otherwise it is safe to free the
2057 * object.
2058 *
2059 * XXXAE: optimize this to use SLIST_REMOVE_AFTER.
2060 */
2061 #define DYN_FREE_STATES(s, next, name) do { \
2062 s = SLIST_FIRST(&V_dyn_expired_ ## name); \
2063 while (s != NULL) { \
2064 next = SLIST_NEXT(s, expired); \
2065 for (i = 0; i < cached_count; i++) \
2066 if (dyn_hp_cache[i] == s) \
2067 break; \
2068 if (i == cached_count) { \
2069 if (s->type == O_LIMIT_PARENT && \
2070 s->limit->count != 0) { \
2071 s = next; \
2072 continue; \
2073 } \
2074 SLIST_REMOVE(&V_dyn_expired_ ## name, \
2075 s, dyn_ ## name ## _state, expired); \
2076 if (s->type == O_LIMIT_PARENT) \
2077 uma_zfree(V_dyn_parent_zone, s->limit); \
2078 else \
2079 uma_zfree(V_dyn_data_zone, s->data); \
2080 uma_zfree(V_dyn_ ## name ## _zone, s); \
2081 } \
2082 s = next; \
2083 } \
2084 } while (0)
2085
2086 /*
2087 * Protect access to expired lists with DYN_EXPIRED_LOCK.
2088 * Userland can invoke ipfw_expire_dyn_states() to delete
2089 * specific states, this will lead to modification of expired
2090 * lists.
2091 *
2092 * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use
2093 * IPFW_UH_WLOCK to protect access to these lists.
2094 */
2095 DYN_EXPIRED_LOCK();
2096 DYN_FREE_STATES(s4, s4n, ipv4);
2097 #ifdef INET6
2098 DYN_FREE_STATES(s6, s6n, ipv6);
2099 #endif
2100 DYN_EXPIRED_UNLOCK();
2101 #undef DYN_FREE_STATES
2102 }
2103
2104 /*
2105 * Returns:
2106 * 0 when state is not matched by specified range;
2107 * 1 when state is matched by specified range;
2108 * 2 when state is matched by specified range and requested deletion of
2109 * dynamic states.
2110 */
2111 static int
2112 dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt)
2113 {
2114
2115 MPASS(rt != NULL);
2116 /* flush all states */
2117 if (rt->flags & IPFW_RCFLAG_ALL) {
2118 if (rt->flags & IPFW_RCFLAG_DYNAMIC)
2119 return (2); /* forced */
2120 return (1);
2121 }
2122 if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set)
2123 return (0);
2124 if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 &&
2125 (rulenum < rt->start_rule || rulenum > rt->end_rule))
2126 return (0);
2127 if (rt->flags & IPFW_RCFLAG_DYNAMIC)
2128 return (2);
2129 return (1);
2130 }
2131
2132 static void
2133 dyn_acquire_rule(struct ip_fw_chain *ch, struct dyn_data *data,
2134 struct ip_fw *rule, uint16_t kidx)
2135 {
2136 struct dyn_state_obj *obj;
2137
2138 /*
2139 * Do not acquire reference twice.
2140 * This can happen when rule deletion executed for
2141 * the same range, but different ruleset id.
2142 */
2143 if (data->flags & DYN_REFERENCED)
2144 return;
2145
2146 IPFW_UH_WLOCK_ASSERT(ch);
2147 MPASS(kidx != 0);
2148
2149 data->flags |= DYN_REFERENCED;
2150 /* Reference the named object */
2151 obj = SRV_OBJECT(ch, kidx);
2152 obj->no.refcnt++;
2153 MPASS(obj->no.etlv == IPFW_TLV_STATE_NAME);
2154
2155 /* Reference the parent rule */
2156 rule->refcnt++;
2157 }
2158
2159 static void
2160 dyn_release_rule(struct ip_fw_chain *ch, struct dyn_data *data,
2161 struct ip_fw *rule, uint16_t kidx)
2162 {
2163 struct dyn_state_obj *obj;
2164
2165 IPFW_UH_WLOCK_ASSERT(ch);
2166 MPASS(kidx != 0);
2167
2168 obj = SRV_OBJECT(ch, kidx);
2169 if (obj->no.refcnt == 1)
2170 dyn_destroy(ch, &obj->no);
2171 else
2172 obj->no.refcnt--;
2173
2174 if (--rule->refcnt == 1)
2175 ipfw_free_rule(rule);
2176 }
2177
2178 /*
2179 * We do not keep O_LIMIT_PARENT states when V_dyn_keep_states is enabled.
2180 * O_LIMIT state is created when new connection is going to be established
2181 * and there is no matching state. So, since the old parent rule was deleted
2182 * we can't create new states with old parent, and thus we can not account
2183 * new connections with already established connections, and can not do
2184 * proper limiting.
2185 */
2186 static int
2187 dyn_match_ipv4_state(struct ip_fw_chain *ch, struct dyn_ipv4_state *s,
2188 const ipfw_range_tlv *rt)
2189 {
2190 struct ip_fw *rule;
2191 int ret;
2192
2193 if (s->type == O_LIMIT_PARENT) {
2194 rule = s->limit->parent;
2195 return (dyn_match_range(s->limit->rulenum, rule->set, rt));
2196 }
2197
2198 rule = s->data->parent;
2199 if (s->type == O_LIMIT)
2200 rule = ((struct dyn_ipv4_state *)rule)->limit->parent;
2201
2202 ret = dyn_match_range(s->data->rulenum, rule->set, rt);
2203 if (ret == 0 || V_dyn_keep_states == 0 || ret > 1)
2204 return (ret);
2205
2206 dyn_acquire_rule(ch, s->data, rule, s->kidx);
2207 return (0);
2208 }
2209
2210 #ifdef INET6
2211 static int
2212 dyn_match_ipv6_state(struct ip_fw_chain *ch, struct dyn_ipv6_state *s,
2213 const ipfw_range_tlv *rt)
2214 {
2215 struct ip_fw *rule;
2216 int ret;
2217
2218 if (s->type == O_LIMIT_PARENT) {
2219 rule = s->limit->parent;
2220 return (dyn_match_range(s->limit->rulenum, rule->set, rt));
2221 }
2222
2223 rule = s->data->parent;
2224 if (s->type == O_LIMIT)
2225 rule = ((struct dyn_ipv6_state *)rule)->limit->parent;
2226
2227 ret = dyn_match_range(s->data->rulenum, rule->set, rt);
2228 if (ret == 0 || V_dyn_keep_states == 0 || ret > 1)
2229 return (ret);
2230
2231 dyn_acquire_rule(ch, s->data, rule, s->kidx);
2232 return (0);
2233 }
2234 #endif
2235
2236 /*
2237 * Unlink expired entries from states lists.
2238 * @rt can be used to specify the range of states for deletion.
2239 */
2240 static void
2241 dyn_expire_states(struct ip_fw_chain *ch, ipfw_range_tlv *rt)
2242 {
2243 struct dyn_ipv4_slist expired_ipv4;
2244 #ifdef INET6
2245 struct dyn_ipv6_slist expired_ipv6;
2246 struct dyn_ipv6_state *s6, *s6n, *s6p;
2247 #endif
2248 struct dyn_ipv4_state *s4, *s4n, *s4p;
2249 void *rule;
2250 int bucket, removed, length, max_length;
2251
2252 IPFW_UH_WLOCK_ASSERT(ch);
2253
2254 /*
2255 * Unlink expired states from each bucket.
2256 * With acquired bucket lock iterate entries of each lists:
2257 * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time
2258 * and unlink entry from the list, link entry into temporary
2259 * expired_xxx lists then bump "del" bucket version.
2260 *
2261 * When an entry is removed, corresponding states counter is
2262 * decremented. If entry has O_LIMIT type, parent's reference
2263 * counter is decremented.
2264 *
2265 * NOTE: this function can be called from userspace context
2266 * when user deletes rules. In this case all matched states
2267 * will be forcedly unlinked. O_LIMIT_PARENT states will be kept
2268 * in the expired lists until reference counter become zero.
2269 */
2270 #define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra) do { \
2271 length = 0; \
2272 removed = 0; \
2273 prev = NULL; \
2274 s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]); \
2275 while (s != NULL) { \
2276 next = CK_SLIST_NEXT(s, entry); \
2277 if ((TIME_LEQ((s)->exp, time_uptime) && extra) || \
2278 (rt != NULL && \
2279 dyn_match_ ## af ## _state(ch, s, rt))) { \
2280 if (prev != NULL) \
2281 CK_SLIST_REMOVE_AFTER(prev, entry); \
2282 else \
2283 CK_SLIST_REMOVE_HEAD( \
2284 &V_dyn_ ## name [bucket], entry); \
2285 removed++; \
2286 SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \
2287 if (s->type == O_LIMIT_PARENT) \
2288 DYN_COUNT_DEC(dyn_parent_count); \
2289 else { \
2290 DYN_COUNT_DEC(dyn_count); \
2291 if (s->data->flags & DYN_REFERENCED) { \
2292 rule = s->data->parent; \
2293 if (s->type == O_LIMIT) \
2294 rule = ((__typeof(s)) \
2295 rule)->limit->parent;\
2296 dyn_release_rule(ch, s->data, \
2297 rule, s->kidx); \
2298 } \
2299 if (s->type == O_LIMIT) { \
2300 s = s->data->parent; \
2301 DPARENT_COUNT_DEC(s->limit); \
2302 } \
2303 } \
2304 } else { \
2305 prev = s; \
2306 length++; \
2307 } \
2308 s = next; \
2309 } \
2310 if (removed != 0) \
2311 DYN_BUCKET_VERSION_BUMP(bucket, name ## _del); \
2312 if (length > max_length) \
2313 max_length = length; \
2314 } while (0)
2315
2316 SLIST_INIT(&expired_ipv4);
2317 #ifdef INET6
2318 SLIST_INIT(&expired_ipv6);
2319 #endif
2320 max_length = 0;
2321 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2322 DYN_BUCKET_LOCK(bucket);
2323 DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1);
2324 DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4,
2325 ipv4_parent, (s4->limit->count == 0));
2326 #ifdef INET6
2327 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1);
2328 DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6,
2329 ipv6_parent, (s6->limit->count == 0));
2330 #endif
2331 DYN_BUCKET_UNLOCK(bucket);
2332 }
2333 /* Update curr_max_length for statistics. */
2334 V_curr_max_length = max_length;
2335 /*
2336 * Concatenate temporary lists with global expired lists.
2337 */
2338 DYN_EXPIRED_LOCK();
2339 SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4,
2340 dyn_ipv4_state, expired);
2341 #ifdef INET6
2342 SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6,
2343 dyn_ipv6_state, expired);
2344 #endif
2345 DYN_EXPIRED_UNLOCK();
2346 #undef DYN_UNLINK_STATES
2347 #undef DYN_UNREF_STATES
2348 }
2349
2350 static struct mbuf *
2351 dyn_mgethdr(int len, uint16_t fibnum)
2352 {
2353 struct mbuf *m;
2354
2355 m = m_gethdr(M_NOWAIT, MT_DATA);
2356 if (m == NULL)
2357 return (NULL);
2358 #ifdef MAC
2359 mac_netinet_firewall_send(m);
2360 #endif
2361 M_SETFIB(m, fibnum);
2362 m->m_data += max_linkhdr;
2363 m->m_flags |= M_SKIP_FIREWALL;
2364 m->m_len = m->m_pkthdr.len = len;
2365 bzero(m->m_data, len);
2366 return (m);
2367 }
2368
2369 static void
2370 dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst,
2371 uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport)
2372 {
2373 struct tcphdr *tcp;
2374 struct ip *ip;
2375
2376 ip = mtod(m, struct ip *);
2377 ip->ip_v = 4;
2378 ip->ip_hl = sizeof(*ip) >> 2;
2379 ip->ip_tos = IPTOS_LOWDELAY;
2380 ip->ip_len = htons(m->m_len);
2381 ip->ip_off |= htons(IP_DF);
2382 ip->ip_ttl = V_ip_defttl;
2383 ip->ip_p = IPPROTO_TCP;
2384 ip->ip_src.s_addr = htonl(src);
2385 ip->ip_dst.s_addr = htonl(dst);
2386
2387 tcp = mtodo(m, sizeof(struct ip));
2388 tcp->th_sport = htons(sport);
2389 tcp->th_dport = htons(dport);
2390 tcp->th_off = sizeof(struct tcphdr) >> 2;
2391 tcp->th_seq = htonl(seq);
2392 tcp->th_ack = htonl(ack);
2393 tcp->th_flags = TH_ACK;
2394 tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
2395 htons(sizeof(struct tcphdr) + IPPROTO_TCP));
2396
2397 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2398 m->m_pkthdr.csum_flags = CSUM_TCP;
2399 }
2400
2401 static void
2402 dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s)
2403 {
2404 struct mbuf *m;
2405
2406 if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
2407 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
2408 s->data->fibnum);
2409 if (m != NULL) {
2410 dyn_make_keepalive_ipv4(m, s->dst, s->src,
2411 s->data->ack_fwd - 1, s->data->ack_rev,
2412 s->dport, s->sport);
2413 if (mbufq_enqueue(q, m)) {
2414 m_freem(m);
2415 log(LOG_DEBUG, "ipfw: limit for IPv4 "
2416 "keepalive queue is reached.\n");
2417 return;
2418 }
2419 }
2420 }
2421
2422 if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
2423 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
2424 s->data->fibnum);
2425 if (m != NULL) {
2426 dyn_make_keepalive_ipv4(m, s->src, s->dst,
2427 s->data->ack_rev - 1, s->data->ack_fwd,
2428 s->sport, s->dport);
2429 if (mbufq_enqueue(q, m)) {
2430 m_freem(m);
2431 log(LOG_DEBUG, "ipfw: limit for IPv4 "
2432 "keepalive queue is reached.\n");
2433 return;
2434 }
2435 }
2436 }
2437 }
2438
2439 /*
2440 * Prepare and send keep-alive packets.
2441 */
2442 static void
2443 dyn_send_keepalive_ipv4(struct ip_fw_chain *chain)
2444 {
2445 struct mbufq q;
2446 struct mbuf *m;
2447 struct dyn_ipv4_state *s;
2448 uint32_t bucket;
2449
2450 mbufq_init(&q, INT_MAX);
2451 IPFW_UH_RLOCK(chain);
2452 /*
2453 * It is safe to not use hazard pointer and just do lockless
2454 * access to the lists, because states entries can not be deleted
2455 * while we hold IPFW_UH_RLOCK.
2456 */
2457 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2458 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
2459 /*
2460 * Only established TCP connections that will
2461 * become expired withing dyn_keepalive_interval.
2462 */
2463 if (s->proto != IPPROTO_TCP ||
2464 (s->data->state & BOTH_SYN) != BOTH_SYN ||
2465 TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
2466 s->data->expire))
2467 continue;
2468 dyn_enqueue_keepalive_ipv4(&q, s);
2469 }
2470 }
2471 IPFW_UH_RUNLOCK(chain);
2472 while ((m = mbufq_dequeue(&q)) != NULL)
2473 ip_output(m, NULL, NULL, 0, NULL, NULL);
2474 }
2475
2476 #ifdef INET6
2477 static void
2478 dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src,
2479 const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack,
2480 uint16_t sport, uint16_t dport)
2481 {
2482 struct tcphdr *tcp;
2483 struct ip6_hdr *ip6;
2484
2485 ip6 = mtod(m, struct ip6_hdr *);
2486 ip6->ip6_vfc |= IPV6_VERSION;
2487 ip6->ip6_plen = htons(sizeof(struct tcphdr));
2488 ip6->ip6_nxt = IPPROTO_TCP;
2489 ip6->ip6_hlim = IPV6_DEFHLIM;
2490 ip6->ip6_src = *src;
2491 if (IN6_IS_ADDR_LINKLOCAL(src))
2492 ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff);
2493 ip6->ip6_dst = *dst;
2494 if (IN6_IS_ADDR_LINKLOCAL(dst))
2495 ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff);
2496
2497 tcp = mtodo(m, sizeof(struct ip6_hdr));
2498 tcp->th_sport = htons(sport);
2499 tcp->th_dport = htons(dport);
2500 tcp->th_off = sizeof(struct tcphdr) >> 2;
2501 tcp->th_seq = htonl(seq);
2502 tcp->th_ack = htonl(ack);
2503 tcp->th_flags = TH_ACK;
2504 tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr),
2505 IPPROTO_TCP, 0);
2506
2507 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2508 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
2509 }
2510
2511 static void
2512 dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s)
2513 {
2514 struct mbuf *m;
2515
2516 if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
2517 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
2518 sizeof(struct tcphdr), s->data->fibnum);
2519 if (m != NULL) {
2520 dyn_make_keepalive_ipv6(m, &s->dst, &s->src,
2521 s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev,
2522 s->dport, s->sport);
2523 if (mbufq_enqueue(q, m)) {
2524 m_freem(m);
2525 log(LOG_DEBUG, "ipfw: limit for IPv6 "
2526 "keepalive queue is reached.\n");
2527 return;
2528 }
2529 }
2530 }
2531
2532 if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
2533 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
2534 sizeof(struct tcphdr), s->data->fibnum);
2535 if (m != NULL) {
2536 dyn_make_keepalive_ipv6(m, &s->src, &s->dst,
2537 s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd,
2538 s->sport, s->dport);
2539 if (mbufq_enqueue(q, m)) {
2540 m_freem(m);
2541 log(LOG_DEBUG, "ipfw: limit for IPv6 "
2542 "keepalive queue is reached.\n");
2543 return;
2544 }
2545 }
2546 }
2547 }
2548
2549 static void
2550 dyn_send_keepalive_ipv6(struct ip_fw_chain *chain)
2551 {
2552 struct mbufq q;
2553 struct mbuf *m;
2554 struct dyn_ipv6_state *s;
2555 uint32_t bucket;
2556
2557 mbufq_init(&q, INT_MAX);
2558 IPFW_UH_RLOCK(chain);
2559 /*
2560 * It is safe to not use hazard pointer and just do lockless
2561 * access to the lists, because states entries can not be deleted
2562 * while we hold IPFW_UH_RLOCK.
2563 */
2564 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2565 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
2566 /*
2567 * Only established TCP connections that will
2568 * become expired withing dyn_keepalive_interval.
2569 */
2570 if (s->proto != IPPROTO_TCP ||
2571 (s->data->state & BOTH_SYN) != BOTH_SYN ||
2572 TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
2573 s->data->expire))
2574 continue;
2575 dyn_enqueue_keepalive_ipv6(&q, s);
2576 }
2577 }
2578 IPFW_UH_RUNLOCK(chain);
2579 while ((m = mbufq_dequeue(&q)) != NULL)
2580 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
2581 }
2582 #endif /* INET6 */
2583
2584 static void
2585 dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new, int flags)
2586 {
2587 #ifdef INET6
2588 struct dyn_ipv6ck_slist *ipv6, *ipv6_parent;
2589 uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del;
2590 struct dyn_ipv6_state *s6;
2591 #endif
2592 struct dyn_ipv4ck_slist *ipv4, *ipv4_parent;
2593 uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del;
2594 struct dyn_ipv4_state *s4;
2595 struct mtx *bucket_lock;
2596 void *tmp;
2597 uint32_t bucket;
2598
2599 MPASS(powerof2(new));
2600 DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new);
2601 /*
2602 * Allocate and initialize new lists.
2603 */
2604 bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW,
2605 flags | M_ZERO);
2606 if (bucket_lock == NULL)
2607 return;
2608
2609 ipv4 = ipv4_parent = NULL;
2610 ipv4_add = ipv4_del = ipv4_parent_add = ipv4_parent_del = NULL;
2611 #ifdef INET6
2612 ipv6 = ipv6_parent = NULL;
2613 ipv6_add = ipv6_del = ipv6_parent_add = ipv6_parent_del = NULL;
2614 #endif
2615
2616 ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
2617 flags | M_ZERO);
2618 if (ipv4 == NULL)
2619 goto bad;
2620 ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
2621 flags | M_ZERO);
2622 if (ipv4_parent == NULL)
2623 goto bad;
2624 ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
2625 if (ipv4_add == NULL)
2626 goto bad;
2627 ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
2628 if (ipv4_del == NULL)
2629 goto bad;
2630 ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
2631 flags | M_ZERO);
2632 if (ipv4_parent_add == NULL)
2633 goto bad;
2634 ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
2635 flags | M_ZERO);
2636 if (ipv4_parent_del == NULL)
2637 goto bad;
2638 #ifdef INET6
2639 ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
2640 flags | M_ZERO);
2641 if (ipv6 == NULL)
2642 goto bad;
2643 ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
2644 flags | M_ZERO);
2645 if (ipv6_parent == NULL)
2646 goto bad;
2647 ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
2648 if (ipv6_add == NULL)
2649 goto bad;
2650 ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
2651 if (ipv6_del == NULL)
2652 goto bad;
2653 ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
2654 flags | M_ZERO);
2655 if (ipv6_parent_add == NULL)
2656 goto bad;
2657 ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
2658 flags | M_ZERO);
2659 if (ipv6_parent_del == NULL)
2660 goto bad;
2661 #endif
2662 for (bucket = 0; bucket < new; bucket++) {
2663 DYN_BUCKET_LOCK_INIT(bucket_lock, bucket);
2664 CK_SLIST_INIT(&ipv4[bucket]);
2665 CK_SLIST_INIT(&ipv4_parent[bucket]);
2666 #ifdef INET6
2667 CK_SLIST_INIT(&ipv6[bucket]);
2668 CK_SLIST_INIT(&ipv6_parent[bucket]);
2669 #endif
2670 }
2671
2672 #define DYN_RELINK_STATES(s, hval, i, head, ohead) do { \
2673 while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) { \
2674 CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry); \
2675 CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)], \
2676 s, entry); \
2677 } \
2678 } while (0)
2679 /*
2680 * Prevent rules changing from userland.
2681 */
2682 IPFW_UH_WLOCK(chain);
2683 /*
2684 * Hold traffic processing until we finish resize to
2685 * prevent access to states lists.
2686 */
2687 IPFW_WLOCK(chain);
2688 /* Re-link all dynamic states */
2689 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2690 DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4);
2691 DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent,
2692 ipv4_parent);
2693 #ifdef INET6
2694 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6);
2695 DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent,
2696 ipv6_parent);
2697 #endif
2698 }
2699
2700 #define DYN_SWAP_PTR(old, new, tmp) do { \
2701 tmp = old; \
2702 old = new; \
2703 new = tmp; \
2704 } while (0)
2705 /* Swap pointers */
2706 DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp);
2707 DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp);
2708 DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp);
2709 DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp);
2710 DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp);
2711 DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp);
2712 DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp);
2713
2714 #ifdef INET6
2715 DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp);
2716 DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp);
2717 DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp);
2718 DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp);
2719 DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp);
2720 DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp);
2721 #endif
2722 bucket = V_curr_dyn_buckets;
2723 V_curr_dyn_buckets = new;
2724
2725 IPFW_WUNLOCK(chain);
2726 IPFW_UH_WUNLOCK(chain);
2727
2728 /* Release old resources */
2729 while (bucket-- != 0)
2730 DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket);
2731 bad:
2732 free(bucket_lock, M_IPFW);
2733 free(ipv4, M_IPFW);
2734 free(ipv4_parent, M_IPFW);
2735 free(ipv4_add, M_IPFW);
2736 free(ipv4_parent_add, M_IPFW);
2737 free(ipv4_del, M_IPFW);
2738 free(ipv4_parent_del, M_IPFW);
2739 #ifdef INET6
2740 free(ipv6, M_IPFW);
2741 free(ipv6_parent, M_IPFW);
2742 free(ipv6_add, M_IPFW);
2743 free(ipv6_parent_add, M_IPFW);
2744 free(ipv6_del, M_IPFW);
2745 free(ipv6_parent_del, M_IPFW);
2746 #endif
2747 }
2748
2749 /*
2750 * This function is used to perform various maintenance
2751 * on dynamic hash lists. Currently it is called every second.
2752 */
2753 static void
2754 dyn_tick(void *vnetx)
2755 {
2756 struct epoch_tracker et;
2757 uint32_t buckets;
2758
2759 CURVNET_SET((struct vnet *)vnetx);
2760 /*
2761 * First free states unlinked in previous passes.
2762 */
2763 dyn_free_states(&V_layer3_chain);
2764 /*
2765 * Now unlink others expired states.
2766 * We use IPFW_UH_WLOCK to avoid concurrent call of
2767 * dyn_expire_states(). It is the only function that does
2768 * deletion of state entries from states lists.
2769 */
2770 IPFW_UH_WLOCK(&V_layer3_chain);
2771 dyn_expire_states(&V_layer3_chain, NULL);
2772 IPFW_UH_WUNLOCK(&V_layer3_chain);
2773 /*
2774 * Send keepalives if they are enabled and the time has come.
2775 */
2776 if (V_dyn_keepalive != 0 &&
2777 V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) {
2778 V_dyn_keepalive_last = time_uptime;
2779 NET_EPOCH_ENTER(et);
2780 dyn_send_keepalive_ipv4(&V_layer3_chain);
2781 #ifdef INET6
2782 dyn_send_keepalive_ipv6(&V_layer3_chain);
2783 #endif
2784 NET_EPOCH_EXIT(et);
2785 }
2786 /*
2787 * Check if we need to resize the hash:
2788 * if current number of states exceeds number of buckets in hash,
2789 * and dyn_buckets_max permits to grow the number of buckets, then
2790 * do it. Grow hash size to the minimum power of 2 which is bigger
2791 * than current states count.
2792 */
2793 if (V_curr_dyn_buckets < V_dyn_buckets_max &&
2794 (V_curr_dyn_buckets < V_dyn_count / 2 || (
2795 V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) {
2796 buckets = 1 << fls(V_dyn_count);
2797 if (buckets > V_dyn_buckets_max)
2798 buckets = V_dyn_buckets_max;
2799 dyn_grow_hashtable(&V_layer3_chain, buckets, M_NOWAIT);
2800 }
2801
2802 callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0);
2803 CURVNET_RESTORE();
2804 }
2805
2806 void
2807 ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
2808 {
2809 /*
2810 * Do not perform any checks if we currently have no dynamic states
2811 */
2812 if (V_dyn_count == 0)
2813 return;
2814
2815 IPFW_UH_WLOCK_ASSERT(chain);
2816 dyn_expire_states(chain, rt);
2817 }
2818
2819 /*
2820 * Pass through all states and reset eaction for orphaned rules.
2821 */
2822 void
2823 ipfw_dyn_reset_eaction(struct ip_fw_chain *ch, uint16_t eaction_id,
2824 uint16_t default_id, uint16_t instance_id)
2825 {
2826 #ifdef INET6
2827 struct dyn_ipv6_state *s6;
2828 #endif
2829 struct dyn_ipv4_state *s4;
2830 struct ip_fw *rule;
2831 uint32_t bucket;
2832
2833 #define DYN_RESET_EACTION(s, h, b) \
2834 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \
2835 if ((s->data->flags & DYN_REFERENCED) == 0) \
2836 continue; \
2837 rule = s->data->parent; \
2838 if (s->type == O_LIMIT) \
2839 rule = ((__typeof(s))rule)->limit->parent; \
2840 ipfw_reset_eaction(ch, rule, eaction_id, \
2841 default_id, instance_id); \
2842 }
2843
2844 IPFW_UH_WLOCK_ASSERT(ch);
2845 if (V_dyn_count == 0)
2846 return;
2847 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2848 DYN_RESET_EACTION(s4, ipv4, bucket);
2849 #ifdef INET6
2850 DYN_RESET_EACTION(s6, ipv6, bucket);
2851 #endif
2852 }
2853 }
2854
2855 /*
2856 * Returns size of dynamic states in legacy format
2857 */
2858 int
2859 ipfw_dyn_len(void)
2860 {
2861
2862 return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule));
2863 }
2864
2865 /*
2866 * Returns number of dynamic states.
2867 * Marks every named object index used by dynamic states with bit in @bmask.
2868 * Returns number of named objects accounted in bmask via @nocnt.
2869 * Used by dump format v1 (current).
2870 */
2871 uint32_t
2872 ipfw_dyn_get_count(uint32_t *bmask, int *nocnt)
2873 {
2874 #ifdef INET6
2875 struct dyn_ipv6_state *s6;
2876 #endif
2877 struct dyn_ipv4_state *s4;
2878 uint32_t bucket;
2879
2880 #define DYN_COUNT_OBJECTS(s, h, b) \
2881 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \
2882 MPASS(s->kidx != 0); \
2883 if (ipfw_mark_object_kidx(bmask, IPFW_TLV_STATE_NAME, \
2884 s->kidx) != 0) \
2885 (*nocnt)++; \
2886 }
2887
2888 IPFW_UH_RLOCK_ASSERT(&V_layer3_chain);
2889
2890 /* No need to pass through all the buckets. */
2891 *nocnt = 0;
2892 if (V_dyn_count + V_dyn_parent_count == 0)
2893 return (0);
2894
2895 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2896 DYN_COUNT_OBJECTS(s4, ipv4, bucket);
2897 #ifdef INET6
2898 DYN_COUNT_OBJECTS(s6, ipv6, bucket);
2899 #endif
2900 }
2901
2902 return (V_dyn_count + V_dyn_parent_count);
2903 }
2904
2905 /*
2906 * Check if rule contains at least one dynamic opcode.
2907 *
2908 * Returns 1 if such opcode is found, 0 otherwise.
2909 */
2910 int
2911 ipfw_is_dyn_rule(struct ip_fw *rule)
2912 {
2913 int cmdlen, l;
2914 ipfw_insn *cmd;
2915
2916 l = rule->cmd_len;
2917 cmd = rule->cmd;
2918 cmdlen = 0;
2919 for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) {
2920 cmdlen = F_LEN(cmd);
2921
2922 switch (cmd->opcode) {
2923 case O_LIMIT:
2924 case O_KEEP_STATE:
2925 case O_PROBE_STATE:
2926 case O_CHECK_STATE:
2927 return (1);
2928 }
2929 }
2930
2931 return (0);
2932 }
2933
2934 static void
2935 dyn_export_parent(const struct dyn_parent *p, uint16_t kidx, uint8_t set,
2936 ipfw_dyn_rule *dst)
2937 {
2938
2939 dst->dyn_type = O_LIMIT_PARENT;
2940 dst->kidx = kidx;
2941 dst->count = (uint16_t)DPARENT_COUNT(p);
2942 dst->expire = TIME_LEQ(p->expire, time_uptime) ? 0:
2943 p->expire - time_uptime;
2944
2945 /* 'rule' is used to pass up the rule number and set */
2946 memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum));
2947
2948 /* store set number into high word of dst->rule pointer. */
2949 memcpy((char *)&dst->rule + sizeof(p->rulenum), &set, sizeof(set));
2950
2951 /* unused fields */
2952 dst->pcnt = 0;
2953 dst->bcnt = 0;
2954 dst->parent = NULL;
2955 dst->state = 0;
2956 dst->ack_fwd = 0;
2957 dst->ack_rev = 0;
2958 dst->bucket = p->hashval;
2959 /*
2960 * The legacy userland code will interpret a NULL here as a marker
2961 * for the last dynamic rule.
2962 */
2963 dst->next = (ipfw_dyn_rule *)1;
2964 }
2965
2966 static void
2967 dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type,
2968 uint8_t set, ipfw_dyn_rule *dst)
2969 {
2970
2971 dst->dyn_type = type;
2972 dst->kidx = kidx;
2973 dst->pcnt = data->pcnt_fwd + data->pcnt_rev;
2974 dst->bcnt = data->bcnt_fwd + data->bcnt_rev;
2975 dst->expire = TIME_LEQ(data->expire, time_uptime) ? 0:
2976 data->expire - time_uptime;
2977
2978 /* 'rule' is used to pass up the rule number and set */
2979 memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum));
2980
2981 /* store set number into high word of dst->rule pointer. */
2982 memcpy((char *)&dst->rule + sizeof(data->rulenum), &set, sizeof(set));
2983
2984 dst->state = data->state;
2985 if (data->flags & DYN_REFERENCED)
2986 dst->state |= IPFW_DYN_ORPHANED;
2987
2988 /* unused fields */
2989 dst->parent = NULL;
2990 dst->ack_fwd = data->ack_fwd;
2991 dst->ack_rev = data->ack_rev;
2992 dst->count = 0;
2993 dst->bucket = data->hashval;
2994 /*
2995 * The legacy userland code will interpret a NULL here as a marker
2996 * for the last dynamic rule.
2997 */
2998 dst->next = (ipfw_dyn_rule *)1;
2999 }
3000
3001 static void
3002 dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst)
3003 {
3004 struct ip_fw *rule;
3005
3006 switch (s->type) {
3007 case O_LIMIT_PARENT:
3008 rule = s->limit->parent;
3009 dyn_export_parent(s->limit, s->kidx, rule->set, dst);
3010 break;
3011 default:
3012 rule = s->data->parent;
3013 if (s->type == O_LIMIT)
3014 rule = ((struct dyn_ipv4_state *)rule)->limit->parent;
3015 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst);
3016 }
3017
3018 dst->id.dst_ip = s->dst;
3019 dst->id.src_ip = s->src;
3020 dst->id.dst_port = s->dport;
3021 dst->id.src_port = s->sport;
3022 dst->id.fib = s->data->fibnum;
3023 dst->id.proto = s->proto;
3024 dst->id._flags = 0;
3025 dst->id.addr_type = 4;
3026
3027 memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6));
3028 memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6));
3029 dst->id.flow_id6 = dst->id.extra = 0;
3030 }
3031
3032 #ifdef INET6
3033 static void
3034 dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst)
3035 {
3036 struct ip_fw *rule;
3037
3038 switch (s->type) {
3039 case O_LIMIT_PARENT:
3040 rule = s->limit->parent;
3041 dyn_export_parent(s->limit, s->kidx, rule->set, dst);
3042 break;
3043 default:
3044 rule = s->data->parent;
3045 if (s->type == O_LIMIT)
3046 rule = ((struct dyn_ipv6_state *)rule)->limit->parent;
3047 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst);
3048 }
3049
3050 dst->id.src_ip6 = s->src;
3051 dst->id.dst_ip6 = s->dst;
3052 dst->id.dst_port = s->dport;
3053 dst->id.src_port = s->sport;
3054 dst->id.fib = s->data->fibnum;
3055 dst->id.proto = s->proto;
3056 dst->id._flags = 0;
3057 dst->id.addr_type = 6;
3058
3059 dst->id.dst_ip = dst->id.src_ip = 0;
3060 dst->id.flow_id6 = dst->id.extra = 0;
3061 }
3062 #endif /* INET6 */
3063
3064 /*
3065 * Fills the buffer given by @sd with dynamic states.
3066 * Used by dump format v1 (current).
3067 *
3068 * Returns 0 on success.
3069 */
3070 int
3071 ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd)
3072 {
3073 #ifdef INET6
3074 struct dyn_ipv6_state *s6;
3075 #endif
3076 struct dyn_ipv4_state *s4;
3077 ipfw_obj_dyntlv *dst, *last;
3078 ipfw_obj_ctlv *ctlv;
3079 uint32_t bucket;
3080
3081 if (V_dyn_count == 0)
3082 return (0);
3083
3084 /*
3085 * IPFW_UH_RLOCK garantees that another userland request
3086 * and callout thread will not delete entries from states
3087 * lists.
3088 */
3089 IPFW_UH_RLOCK_ASSERT(chain);
3090
3091 ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
3092 if (ctlv == NULL)
3093 return (ENOMEM);
3094 ctlv->head.type = IPFW_TLV_DYNSTATE_LIST;
3095 ctlv->objsize = sizeof(ipfw_obj_dyntlv);
3096 last = NULL;
3097
3098 #define DYN_EXPORT_STATES(s, af, h, b) \
3099 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \
3100 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd, \
3101 sizeof(ipfw_obj_dyntlv)); \
3102 if (dst == NULL) \
3103 return (ENOMEM); \
3104 dyn_export_ ## af ## _state(s, &dst->state); \
3105 dst->head.length = sizeof(ipfw_obj_dyntlv); \
3106 dst->head.type = IPFW_TLV_DYN_ENT; \
3107 last = dst; \
3108 }
3109
3110 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
3111 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
3112 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
3113 #ifdef INET6
3114 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
3115 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
3116 #endif /* INET6 */
3117 }
3118
3119 /* mark last dynamic rule */
3120 if (last != NULL)
3121 last->head.flags = IPFW_DF_LAST; /* XXX: unused */
3122 return (0);
3123 #undef DYN_EXPORT_STATES
3124 }
3125
3126 /*
3127 * Fill given buffer with dynamic states (legacy format).
3128 * IPFW_UH_RLOCK has to be held while calling.
3129 */
3130 void
3131 ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep)
3132 {
3133 #ifdef INET6
3134 struct dyn_ipv6_state *s6;
3135 #endif
3136 struct dyn_ipv4_state *s4;
3137 ipfw_dyn_rule *p, *last = NULL;
3138 char *bp;
3139 uint32_t bucket;
3140
3141 if (V_dyn_count == 0)
3142 return;
3143 bp = *pbp;
3144
3145 IPFW_UH_RLOCK_ASSERT(chain);
3146
3147 #define DYN_EXPORT_STATES(s, af, head, b) \
3148 CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) { \
3149 if (bp + sizeof(*p) > ep) \
3150 break; \
3151 p = (ipfw_dyn_rule *)bp; \
3152 dyn_export_ ## af ## _state(s, p); \
3153 last = p; \
3154 bp += sizeof(*p); \
3155 }
3156
3157 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
3158 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
3159 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
3160 #ifdef INET6
3161 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
3162 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
3163 #endif /* INET6 */
3164 }
3165
3166 if (last != NULL) /* mark last dynamic rule */
3167 last->next = NULL;
3168 *pbp = bp;
3169 #undef DYN_EXPORT_STATES
3170 }
3171
3172 void
3173 ipfw_dyn_init(struct ip_fw_chain *chain)
3174 {
3175
3176 #ifdef IPFIREWALL_JENKINSHASH
3177 V_dyn_hashseed = arc4random();
3178 #endif
3179 V_dyn_max = 16384; /* max # of states */
3180 V_dyn_parent_max = 4096; /* max # of parent states */
3181 V_dyn_buckets_max = 8192; /* must be power of 2 */
3182
3183 V_dyn_ack_lifetime = 300;
3184 V_dyn_syn_lifetime = 20;
3185 V_dyn_fin_lifetime = 1;
3186 V_dyn_rst_lifetime = 1;
3187 V_dyn_udp_lifetime = 10;
3188 V_dyn_short_lifetime = 5;
3189
3190 V_dyn_keepalive_interval = 20;
3191 V_dyn_keepalive_period = 5;
3192 V_dyn_keepalive = 1; /* send keepalives */
3193 V_dyn_keepalive_last = time_uptime;
3194
3195 V_dyn_data_zone = uma_zcreate("IPFW dynamic states data",
3196 sizeof(struct dyn_data), NULL, NULL, NULL, NULL,
3197 UMA_ALIGN_PTR, 0);
3198 uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
3199
3200 V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states",
3201 sizeof(struct dyn_parent), NULL, NULL, NULL, NULL,
3202 UMA_ALIGN_PTR, 0);
3203 uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
3204
3205 SLIST_INIT(&V_dyn_expired_ipv4);
3206 V_dyn_ipv4 = NULL;
3207 V_dyn_ipv4_parent = NULL;
3208 V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states",
3209 sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL,
3210 UMA_ALIGN_PTR, 0);
3211
3212 #ifdef INET6
3213 SLIST_INIT(&V_dyn_expired_ipv6);
3214 V_dyn_ipv6 = NULL;
3215 V_dyn_ipv6_parent = NULL;
3216 V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states",
3217 sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL,
3218 UMA_ALIGN_PTR, 0);
3219 #endif
3220
3221 /* Initialize buckets. */
3222 V_curr_dyn_buckets = 0;
3223 V_dyn_bucket_lock = NULL;
3224 dyn_grow_hashtable(chain, 256, M_WAITOK);
3225
3226 if (IS_DEFAULT_VNET(curvnet))
3227 dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW,
3228 M_WAITOK | M_ZERO);
3229
3230 DYN_EXPIRED_LOCK_INIT();
3231 callout_init(&V_dyn_timeout, 1);
3232 callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet);
3233 IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
3234 }
3235
3236 void
3237 ipfw_dyn_uninit(int pass)
3238 {
3239 #ifdef INET6
3240 struct dyn_ipv6_state *s6;
3241 #endif
3242 struct dyn_ipv4_state *s4;
3243 int bucket;
3244
3245 if (pass == 0) {
3246 callout_drain(&V_dyn_timeout);
3247 return;
3248 }
3249 IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
3250 DYN_EXPIRED_LOCK_DESTROY();
3251
3252 #define DYN_FREE_STATES_FORCED(CK, s, af, name, en) do { \
3253 while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) { \
3254 CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en); \
3255 if (s->type == O_LIMIT_PARENT) \
3256 uma_zfree(V_dyn_parent_zone, s->limit); \
3257 else \
3258 uma_zfree(V_dyn_data_zone, s->data); \
3259 uma_zfree(V_dyn_ ## af ## _zone, s); \
3260 } \
3261 } while (0)
3262 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
3263 DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket);
3264
3265 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry);
3266 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket],
3267 entry);
3268 #ifdef INET6
3269 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry);
3270 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket],
3271 entry);
3272 #endif /* INET6 */
3273 }
3274 DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired);
3275 #ifdef INET6
3276 DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired);
3277 #endif
3278 #undef DYN_FREE_STATES_FORCED
3279
3280 uma_zdestroy(V_dyn_ipv4_zone);
3281 uma_zdestroy(V_dyn_data_zone);
3282 uma_zdestroy(V_dyn_parent_zone);
3283 #ifdef INET6
3284 uma_zdestroy(V_dyn_ipv6_zone);
3285 free(V_dyn_ipv6, M_IPFW);
3286 free(V_dyn_ipv6_parent, M_IPFW);
3287 free(V_dyn_ipv6_add, M_IPFW);
3288 free(V_dyn_ipv6_parent_add, M_IPFW);
3289 free(V_dyn_ipv6_del, M_IPFW);
3290 free(V_dyn_ipv6_parent_del, M_IPFW);
3291 #endif
3292 free(V_dyn_bucket_lock, M_IPFW);
3293 free(V_dyn_ipv4, M_IPFW);
3294 free(V_dyn_ipv4_parent, M_IPFW);
3295 free(V_dyn_ipv4_add, M_IPFW);
3296 free(V_dyn_ipv4_parent_add, M_IPFW);
3297 free(V_dyn_ipv4_del, M_IPFW);
3298 free(V_dyn_ipv4_parent_del, M_IPFW);
3299 if (IS_DEFAULT_VNET(curvnet))
3300 free(dyn_hp_cache, M_IPFW);
3301 }
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