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Some mdoc fixes in various places.
[dragonfly.git] / sys / net / ipfw / ip_fw2.c
blobafbc59be3e080bf776bb341dbf41418f15b32928
1 /*
2 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD: src/sys/netinet/ip_fw2.c,v 1.6.2.12 2003/04/08 10:42:32 maxim Exp $
26 * $DragonFly: src/sys/net/ipfw/ip_fw2.c,v 1.100 2008/11/22 11:03:35 sephe Exp $
27 */
28
29 /*
30 * Implement IP packet firewall (new version)
31 */
32
33 #include "opt_ipfw.h"
34 #include "opt_inet.h"
35 #ifndef INET
36 #error IPFIREWALL requires INET.
37 #endif /* INET */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/kernel.h>
44 #include <sys/proc.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/sysctl.h>
48 #include <sys/syslog.h>
49 #include <sys/thread2.h>
50 #include <sys/ucred.h>
51 #include <sys/in_cksum.h>
52 #include <sys/lock.h>
53
54 #include <net/if.h>
55 #include <net/route.h>
56 #include <net/netmsg2.h>
57 #include <net/pfil.h>
58 #include <net/dummynet/ip_dummynet.h>
59
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/in_var.h>
63 #include <netinet/in_pcb.h>
64 #include <netinet/ip.h>
65 #include <netinet/ip_var.h>
66 #include <netinet/ip_icmp.h>
67 #include <netinet/tcp.h>
68 #include <netinet/tcp_timer.h>
69 #include <netinet/tcp_var.h>
70 #include <netinet/tcpip.h>
71 #include <netinet/udp.h>
72 #include <netinet/udp_var.h>
73 #include <netinet/ip_divert.h>
74 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
75
76 #include <net/ipfw/ip_fw2.h>
77
78 #ifdef IPFIREWALL_DEBUG
79 #define DPRINTF(fmt, ...) \
80 do { \
81 if (fw_debug > 0) \
82 kprintf(fmt, __VA_ARGS__); \
83 } while (0)
84 #else
85 #define DPRINTF(fmt, ...) ((void)0)
86 #endif
87
88 /*
89 * Description about per-CPU rule duplication:
90 *
91 * Module loading/unloading and all ioctl operations are serialized
92 * by netisr0, so we don't have any ordering or locking problems.
93 *
94 * Following graph shows how operation on per-CPU rule list is
95 * performed [2 CPU case]:
96 *
97 * CPU0 CPU1
98 *
99 * netisr0 <------------------------------------+
100 * domsg |
101 * | |
102 * | netmsg |
103 * | |
104 * V |
105 * ifnet0 |
106 * : | netmsg
107 * :(delete/add...) |
108 * : |
109 * : netmsg |
110 * forwardmsg---------->ifnet1 |
111 * : |
112 * :(delete/add...) |
113 * : |
114 * : |
115 * replymsg--------------+
116 *
117 *
118 *
119 *
120 * Rules which will not create states (dyn rules) [2 CPU case]
121 *
122 * CPU0 CPU1
123 * layer3_chain layer3_chain
124 * | |
125 * V V
126 * +-------+ sibling +-------+ sibling
127 * | rule1 |--------->| rule1 |--------->NULL
128 * +-------+ +-------+
129 * | |
130 * |next |next
131 * V V
132 * +-------+ sibling +-------+ sibling
133 * | rule2 |--------->| rule2 |--------->NULL
134 * +-------+ +-------+
135 *
136 * ip_fw.sibling:
137 * 1) Ease statistics calculation during IP_FW_GET. We only need to
138 * iterate layer3_chain on CPU0; the current rule's duplication on
139 * the other CPUs could safely be read-only accessed by using
140 * ip_fw.sibling
141 * 2) Accelerate rule insertion and deletion, e.g. rule insertion:
142 * a) In netisr0 (on CPU0) rule3 is determined to be inserted between
143 * rule1 and rule2. To make this decision we need to iterate the
144 * layer3_chain on CPU0. The netmsg, which is used to insert the
145 * rule, will contain rule1 on CPU0 as prev_rule and rule2 on CPU0
146 * as next_rule
147 * b) After the insertion on CPU0 is done, we will move on to CPU1.
148 * But instead of relocating the rule3's position on CPU1 by
149 * iterating the layer3_chain on CPU1, we set the netmsg's prev_rule
150 * to rule1->sibling and next_rule to rule2->sibling before the
151 * netmsg is forwarded to CPU1 from CPU0
152 *
153 *
154 *
155 * Rules which will create states (dyn rules) [2 CPU case]
156 * (unnecessary parts are omitted; they are same as in the previous figure)
157 *
158 * CPU0 CPU1
159 *
160 * +-------+ +-------+
161 * | rule1 | | rule1 |
162 * +-------+ +-------+
163 * ^ | | ^
164 * | |stub stub| |
165 * | | | |
166 * | +----+ +----+ |
167 * | | | |
168 * | V V |
169 * | +--------------------+ |
170 * | | rule_stub | |
171 * | | (read-only shared) | |
172 * | | | |
173 * | | back pointer array | |
174 * | | (indexed by cpuid) | |
175 * | | | |
176 * +----|---------[0] | |
177 * | [1]--------|----+
178 * | |
179 * +--------------------+
180 * ^ ^
181 * | |
182 * ........|............|............
183 * : | | :
184 * : |stub |stub :
185 * : | | :
186 * : +---------+ +---------+ :
187 * : | state1a | | state1b | .... :
188 * : +---------+ +---------+ :
189 * : :
190 * : states table :
191 * : (shared) :
192 * : (protected by dyn_lock) :
193 * ..................................
194 *
195 * [state1a and state1b are states created by rule1]
196 *
197 * ip_fw_stub:
198 * This structure is introduced so that shared (locked) state table could
199 * work with per-CPU (duplicated) static rules. It mainly bridges states
200 * and static rules and serves as static rule's place holder (a read-only
201 * shared part of duplicated rules) from states point of view.
202 *
203 * IPFW_RULE_F_STATE (only for rules which create states):
204 * o During rule installation, this flag is turned on after rule's
205 * duplications reach all CPUs, to avoid at least following race:
206 * 1) rule1 is duplicated on CPU0 and is not duplicated on CPU1 yet
207 * 2) rule1 creates state1
208 * 3) state1 is located on CPU1 by check-state
209 * But rule1 is not duplicated on CPU1 yet
210 * o During rule deletion, this flag is turned off before deleting states
211 * created by the rule and before deleting the rule itself, so no
212 * more states will be created by the to-be-deleted rule even when its
213 * duplication on certain CPUs are not eliminated yet.
214 */
215
216 #define IPFW_AUTOINC_STEP_MIN 1
217 #define IPFW_AUTOINC_STEP_MAX 1000
218 #define IPFW_AUTOINC_STEP_DEF 100
219
220 #define IPFW_DEFAULT_RULE 65535 /* rulenum for the default rule */
221 #define IPFW_DEFAULT_SET 31 /* set number for the default rule */
222
223 struct netmsg_ipfw {
224 struct netmsg nmsg;
225 const struct ipfw_ioc_rule *ioc_rule;
226 struct ip_fw *next_rule;
227 struct ip_fw *prev_rule;
228 struct ip_fw *sibling;
229 struct ip_fw_stub *stub;
230 };
231
232 struct netmsg_del {
233 struct netmsg nmsg;
234 struct ip_fw *start_rule;
235 struct ip_fw *prev_rule;
236 uint16_t rulenum;
237 uint8_t from_set;
238 uint8_t to_set;
239 };
240
241 struct netmsg_zent {
242 struct netmsg nmsg;
243 struct ip_fw *start_rule;
244 uint16_t rulenum;
245 uint16_t log_only;
246 };
247
248 struct ipfw_context {
249 struct ip_fw *ipfw_layer3_chain; /* list of rules for layer3 */
250 struct ip_fw *ipfw_default_rule; /* default rule */
251 uint64_t ipfw_norule_counter; /* counter for ipfw_log(NULL) */
252
253 /*
254 * ipfw_set_disable contains one bit per set value (0..31).
255 * If the bit is set, all rules with the corresponding set
256 * are disabled. Set IPDW_DEFAULT_SET is reserved for the
257 * default rule and CANNOT be disabled.
258 */
259 uint32_t ipfw_set_disable;
260 uint32_t ipfw_gen; /* generation of rule list */
261 };
262
263 static struct ipfw_context *ipfw_ctx[MAXCPU];
264
265 #ifdef KLD_MODULE
266 /*
267 * Module can not be unloaded, if there are references to
268 * certains rules of ipfw(4), e.g. dummynet(4)
269 */
270 static int ipfw_refcnt;
271 #endif
272
273 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
274
275 /*
276 * Following two global variables are accessed and
277 * updated only on CPU0
278 */
279 static uint32_t static_count; /* # of static rules */
280 static uint32_t static_ioc_len; /* bytes of static rules */
281
282 /*
283 * If 1, then ipfw static rules are being flushed,
284 * ipfw_chk() will skip to the default rule.
285 */
286 static int ipfw_flushing;
287
288 static int fw_verbose;
289 static int verbose_limit;
290
291 static int fw_debug;
292 static int autoinc_step = IPFW_AUTOINC_STEP_DEF;
293
294 static int ipfw_sysctl_enable(SYSCTL_HANDLER_ARGS);
295 static int ipfw_sysctl_autoinc_step(SYSCTL_HANDLER_ARGS);
296 static int ipfw_sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS);
297 static int ipfw_sysctl_dyn_fin(SYSCTL_HANDLER_ARGS);
298 static int ipfw_sysctl_dyn_rst(SYSCTL_HANDLER_ARGS);
299
300 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
301 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW,
302 &fw_enable, 0, ipfw_sysctl_enable, "I", "Enable ipfw");
303 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLTYPE_INT | CTLFLAG_RW,
304 &autoinc_step, 0, ipfw_sysctl_autoinc_step, "I",
305 "Rule number autincrement step");
306 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
307 &fw_one_pass, 0,
308 "Only do a single pass through ipfw when using dummynet(4)");
309 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
310 &fw_debug, 0, "Enable printing of debug ip_fw statements");
311 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
312 &fw_verbose, 0, "Log matches to ipfw rules");
313 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
314 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
315
316 /*
317 * Description of dynamic rules.
318 *
319 * Dynamic rules are stored in lists accessed through a hash table
320 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
321 * be modified through the sysctl variable dyn_buckets which is
322 * updated when the table becomes empty.
323 *
324 * XXX currently there is only one list, ipfw_dyn.
325 *
326 * When a packet is received, its address fields are first masked
327 * with the mask defined for the rule, then hashed, then matched
328 * against the entries in the corresponding list.
329 * Dynamic rules can be used for different purposes:
330 * + stateful rules;
331 * + enforcing limits on the number of sessions;
332 * + in-kernel NAT (not implemented yet)
333 *
334 * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
335 * measured in seconds and depending on the flags.
336 *
337 * The total number of dynamic rules is stored in dyn_count.
338 * The max number of dynamic rules is dyn_max. When we reach
339 * the maximum number of rules we do not create anymore. This is
340 * done to avoid consuming too much memory, but also too much
341 * time when searching on each packet (ideally, we should try instead
342 * to put a limit on the length of the list on each bucket...).
343 *
344 * Each dynamic rule holds a pointer to the parent ipfw rule so
345 * we know what action to perform. Dynamic rules are removed when
346 * the parent rule is deleted. XXX we should make them survive.
347 *
348 * There are some limitations with dynamic rules -- we do not
349 * obey the 'randomized match', and we do not do multiple
350 * passes through the firewall. XXX check the latter!!!
351 *
352 * NOTE about the SHARED LOCKMGR LOCK during dynamic rule looking up:
353 * Only TCP state transition will change dynamic rule's state and ack
354 * sequences, while all packets of one TCP connection only goes through
355 * one TCP thread, so it is safe to use shared lockmgr lock during dynamic
356 * rule looking up. The keep alive callout uses exclusive lockmgr lock
357 * when it tries to find suitable dynamic rules to send keep alive, so
358 * it will not see half updated state and ack sequences. Though the expire
359 * field updating looks racy for other protocols, the resolution (second)
360 * of expire field makes this kind of race harmless.
361 * XXX statistics' updating is _not_ MPsafe!!!
362 * XXX once UDP output path is fixed, we could use lockless dynamic rule
363 * hash table
364 */
365 static ipfw_dyn_rule **ipfw_dyn_v = NULL;
366 static uint32_t dyn_buckets = 256; /* must be power of 2 */
367 static uint32_t curr_dyn_buckets = 256; /* must be power of 2 */
368 static uint32_t dyn_buckets_gen; /* generation of dyn buckets array */
369 static struct lock dyn_lock; /* dynamic rules' hash table lock */
370
371 static struct netmsg ipfw_timeout_netmsg; /* schedule ipfw timeout */
372 static struct callout ipfw_timeout_h;
373
374 /*
375 * Timeouts for various events in handing dynamic rules.
376 */
377 static uint32_t dyn_ack_lifetime = 300;
378 static uint32_t dyn_syn_lifetime = 20;
379 static uint32_t dyn_fin_lifetime = 1;
380 static uint32_t dyn_rst_lifetime = 1;
381 static uint32_t dyn_udp_lifetime = 10;
382 static uint32_t dyn_short_lifetime = 5;
383
384 /*
385 * Keepalives are sent if dyn_keepalive is set. They are sent every
386 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
387 * seconds of lifetime of a rule.
388 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
389 * than dyn_keepalive_period.
390 */
391
392 static uint32_t dyn_keepalive_interval = 20;
393 static uint32_t dyn_keepalive_period = 5;
394 static uint32_t dyn_keepalive = 1; /* do send keepalives */
395
396 static uint32_t dyn_count; /* # of dynamic rules */
397 static uint32_t dyn_max = 4096; /* max # of dynamic rules */
398
399 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLTYPE_INT | CTLFLAG_RW,
400 &dyn_buckets, 0, ipfw_sysctl_dyn_buckets, "I", "Number of dyn. buckets");
401 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
402 &curr_dyn_buckets, 0, "Current Number of dyn. buckets");
403 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
404 &dyn_count, 0, "Number of dyn. rules");
405 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
406 &dyn_max, 0, "Max number of dyn. rules");
407 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
408 &static_count, 0, "Number of static rules");
409 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
410 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
411 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
412 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
413 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime,
414 CTLTYPE_INT | CTLFLAG_RW, &dyn_fin_lifetime, 0, ipfw_sysctl_dyn_fin, "I",
415 "Lifetime of dyn. rules for fin");
416 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime,
417 CTLTYPE_INT | CTLFLAG_RW, &dyn_rst_lifetime, 0, ipfw_sysctl_dyn_rst, "I",
418 "Lifetime of dyn. rules for rst");
419 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
420 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
421 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
422 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
423 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
424 &dyn_keepalive, 0, "Enable keepalives for dyn. rules");
425
426 static ip_fw_chk_t ipfw_chk;
427 static void ipfw_tick(void *);
428
429 static __inline int
430 ipfw_free_rule(struct ip_fw *rule)
431 {
432 KASSERT(rule->cpuid == mycpuid, ("rule freed on cpu%d\n", mycpuid));
433 KASSERT(rule->refcnt > 0, ("invalid refcnt %u\n", rule->refcnt));
434 rule->refcnt--;
435 if (rule->refcnt == 0) {
436 kfree(rule, M_IPFW);
437 return 1;
438 }
439 return 0;
440 }
441
442 static void
443 ipfw_unref_rule(void *priv)
444 {
445 ipfw_free_rule(priv);
446 #ifdef KLD_MODULE
447 atomic_subtract_int(&ipfw_refcnt, 1);
448 #endif
449 }
450
451 static __inline void
452 ipfw_ref_rule(struct ip_fw *rule)
453 {
454 KASSERT(rule->cpuid == mycpuid, ("rule used on cpu%d\n", mycpuid));
455 #ifdef KLD_MODULE
456 atomic_add_int(&ipfw_refcnt, 1);
457 #endif
458 rule->refcnt++;
459 }
460
461 /*
462 * This macro maps an ip pointer into a layer3 header pointer of type T
463 */
464 #define L3HDR(T, ip) ((T *)((uint32_t *)(ip) + (ip)->ip_hl))
465
466 static __inline int
467 icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd)
468 {
469 int type = L3HDR(struct icmp,ip)->icmp_type;
470
471 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1 << type)));
472 }
473
474 #define TT ((1 << ICMP_ECHO) | \
475 (1 << ICMP_ROUTERSOLICIT) | \
476 (1 << ICMP_TSTAMP) | \
477 (1 << ICMP_IREQ) | \
478 (1 << ICMP_MASKREQ))
479
480 static int
481 is_icmp_query(struct ip *ip)
482 {
483 int type = L3HDR(struct icmp, ip)->icmp_type;
484
485 return (type <= ICMP_MAXTYPE && (TT & (1 << type)));
486 }
487
488 #undef TT
489
490 /*
491 * The following checks use two arrays of 8 or 16 bits to store the
492 * bits that we want set or clear, respectively. They are in the
493 * low and high half of cmd->arg1 or cmd->d[0].
494 *
495 * We scan options and store the bits we find set. We succeed if
496 *
497 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
498 *
499 * The code is sometimes optimized not to store additional variables.
500 */
501
502 static int
503 flags_match(ipfw_insn *cmd, uint8_t bits)
504 {
505 u_char want_clear;
506 bits = ~bits;
507
508 if (((cmd->arg1 & 0xff) & bits) != 0)
509 return 0; /* some bits we want set were clear */
510
511 want_clear = (cmd->arg1 >> 8) & 0xff;
512 if ((want_clear & bits) != want_clear)
513 return 0; /* some bits we want clear were set */
514 return 1;
515 }
516
517 static int
518 ipopts_match(struct ip *ip, ipfw_insn *cmd)
519 {
520 int optlen, bits = 0;
521 u_char *cp = (u_char *)(ip + 1);
522 int x = (ip->ip_hl << 2) - sizeof(struct ip);
523
524 for (; x > 0; x -= optlen, cp += optlen) {
525 int opt = cp[IPOPT_OPTVAL];
526
527 if (opt == IPOPT_EOL)
528 break;
529
530 if (opt == IPOPT_NOP) {
531 optlen = 1;
532 } else {
533 optlen = cp[IPOPT_OLEN];
534 if (optlen <= 0 || optlen > x)
535 return 0; /* invalid or truncated */
536 }
537
538 switch (opt) {
539 case IPOPT_LSRR:
540 bits |= IP_FW_IPOPT_LSRR;
541 break;
542
543 case IPOPT_SSRR:
544 bits |= IP_FW_IPOPT_SSRR;
545 break;
546
547 case IPOPT_RR:
548 bits |= IP_FW_IPOPT_RR;
549 break;
550
551 case IPOPT_TS:
552 bits |= IP_FW_IPOPT_TS;
553 break;
554
555 default:
556 break;
557 }
558 }
559 return (flags_match(cmd, bits));
560 }
561
562 static int
563 tcpopts_match(struct ip *ip, ipfw_insn *cmd)
564 {
565 int optlen, bits = 0;
566 struct tcphdr *tcp = L3HDR(struct tcphdr,ip);
567 u_char *cp = (u_char *)(tcp + 1);
568 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
569
570 for (; x > 0; x -= optlen, cp += optlen) {
571 int opt = cp[0];
572
573 if (opt == TCPOPT_EOL)
574 break;
575
576 if (opt == TCPOPT_NOP) {
577 optlen = 1;
578 } else {
579 optlen = cp[1];
580 if (optlen <= 0)
581 break;
582 }
583
584 switch (opt) {
585 case TCPOPT_MAXSEG:
586 bits |= IP_FW_TCPOPT_MSS;
587 break;
588
589 case TCPOPT_WINDOW:
590 bits |= IP_FW_TCPOPT_WINDOW;
591 break;
592
593 case TCPOPT_SACK_PERMITTED:
594 case TCPOPT_SACK:
595 bits |= IP_FW_TCPOPT_SACK;
596 break;
597
598 case TCPOPT_TIMESTAMP:
599 bits |= IP_FW_TCPOPT_TS;
600 break;
601
602 case TCPOPT_CC:
603 case TCPOPT_CCNEW:
604 case TCPOPT_CCECHO:
605 bits |= IP_FW_TCPOPT_CC;
606 break;
607
608 default:
609 break;
610 }
611 }
612 return (flags_match(cmd, bits));
613 }
614
615 static int
616 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
617 {
618 if (ifp == NULL) /* no iface with this packet, match fails */
619 return 0;
620
621 /* Check by name or by IP address */
622 if (cmd->name[0] != '\0') { /* match by name */
623 /* Check name */
624 if (cmd->p.glob) {
625 if (kfnmatch(cmd->name, ifp->if_xname, 0) == 0)
626 return(1);
627 } else {
628 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
629 return(1);
630 }
631 } else {
632 struct ifaddr_container *ifac;
633
634 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
635 struct ifaddr *ia = ifac->ifa;
636
637 if (ia->ifa_addr == NULL)
638 continue;
639 if (ia->ifa_addr->sa_family != AF_INET)
640 continue;
641 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
642 (ia->ifa_addr))->sin_addr.s_addr)
643 return(1); /* match */
644 }
645 }
646 return(0); /* no match, fail ... */
647 }
648
649 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
650
651 /*
652 * We enter here when we have a rule with O_LOG.
653 * XXX this function alone takes about 2Kbytes of code!
654 */
655 static void
656 ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh,
657 struct mbuf *m, struct ifnet *oif)
658 {
659 char *action;
660 int limit_reached = 0;
661 char action2[40], proto[48], fragment[28];
662
663 fragment[0] = '\0';
664 proto[0] = '\0';
665
666 if (f == NULL) { /* bogus pkt */
667 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
668
669 if (verbose_limit != 0 &&
670 ctx->ipfw_norule_counter >= verbose_limit)
671 return;
672 ctx->ipfw_norule_counter++;
673 if (ctx->ipfw_norule_counter == verbose_limit)
674 limit_reached = verbose_limit;
675 action = "Refuse";
676 } else { /* O_LOG is the first action, find the real one */
677 ipfw_insn *cmd = ACTION_PTR(f);
678 ipfw_insn_log *l = (ipfw_insn_log *)cmd;
679
680 if (l->max_log != 0 && l->log_left == 0)
681 return;
682 l->log_left--;
683 if (l->log_left == 0)
684 limit_reached = l->max_log;
685 cmd += F_LEN(cmd); /* point to first action */
686 if (cmd->opcode == O_PROB)
687 cmd += F_LEN(cmd);
688
689 action = action2;
690 switch (cmd->opcode) {
691 case O_DENY:
692 action = "Deny";
693 break;
694
695 case O_REJECT:
696 if (cmd->arg1==ICMP_REJECT_RST) {
697 action = "Reset";
698 } else if (cmd->arg1==ICMP_UNREACH_HOST) {
699 action = "Reject";
700 } else {
701 ksnprintf(SNPARGS(action2, 0), "Unreach %d",
702 cmd->arg1);
703 }
704 break;
705
706 case O_ACCEPT:
707 action = "Accept";
708 break;
709
710 case O_COUNT:
711 action = "Count";
712 break;
713
714 case O_DIVERT:
715 ksnprintf(SNPARGS(action2, 0), "Divert %d", cmd->arg1);
716 break;
717
718 case O_TEE:
719 ksnprintf(SNPARGS(action2, 0), "Tee %d", cmd->arg1);
720 break;
721
722 case O_SKIPTO:
723 ksnprintf(SNPARGS(action2, 0), "SkipTo %d", cmd->arg1);
724 break;
725
726 case O_PIPE:
727 ksnprintf(SNPARGS(action2, 0), "Pipe %d", cmd->arg1);
728 break;
729
730 case O_QUEUE:
731 ksnprintf(SNPARGS(action2, 0), "Queue %d", cmd->arg1);
732 break;
733
734 case O_FORWARD_IP:
735 {
736 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
737 int len;
738
739 len = ksnprintf(SNPARGS(action2, 0),
740 "Forward to %s",
741 inet_ntoa(sa->sa.sin_addr));
742 if (sa->sa.sin_port) {
743 ksnprintf(SNPARGS(action2, len), ":%d",
744 sa->sa.sin_port);
745 }
746 }
747 break;
748
749 default:
750 action = "UNKNOWN";
751 break;
752 }
753 }
754
755 if (hlen == 0) { /* non-ip */
756 ksnprintf(SNPARGS(proto, 0), "MAC");
757 } else {
758 struct ip *ip = mtod(m, struct ip *);
759 /* these three are all aliases to the same thing */
760 struct icmp *const icmp = L3HDR(struct icmp, ip);
761 struct tcphdr *const tcp = (struct tcphdr *)icmp;
762 struct udphdr *const udp = (struct udphdr *)icmp;
763
764 int ip_off, offset, ip_len;
765 int len;
766
767 if (eh != NULL) { /* layer 2 packets are as on the wire */
768 ip_off = ntohs(ip->ip_off);
769 ip_len = ntohs(ip->ip_len);
770 } else {
771 ip_off = ip->ip_off;
772 ip_len = ip->ip_len;
773 }
774 offset = ip_off & IP_OFFMASK;
775 switch (ip->ip_p) {
776 case IPPROTO_TCP:
777 len = ksnprintf(SNPARGS(proto, 0), "TCP %s",
778 inet_ntoa(ip->ip_src));
779 if (offset == 0) {
780 ksnprintf(SNPARGS(proto, len), ":%d %s:%d",
781 ntohs(tcp->th_sport),
782 inet_ntoa(ip->ip_dst),
783 ntohs(tcp->th_dport));
784 } else {
785 ksnprintf(SNPARGS(proto, len), " %s",
786 inet_ntoa(ip->ip_dst));
787 }
788 break;
789
790 case IPPROTO_UDP:
791 len = ksnprintf(SNPARGS(proto, 0), "UDP %s",
792 inet_ntoa(ip->ip_src));
793 if (offset == 0) {
794 ksnprintf(SNPARGS(proto, len), ":%d %s:%d",
795 ntohs(udp->uh_sport),
796 inet_ntoa(ip->ip_dst),
797 ntohs(udp->uh_dport));
798 } else {
799 ksnprintf(SNPARGS(proto, len), " %s",
800 inet_ntoa(ip->ip_dst));
801 }
802 break;
803
804 case IPPROTO_ICMP:
805 if (offset == 0) {
806 len = ksnprintf(SNPARGS(proto, 0),
807 "ICMP:%u.%u ",
808 icmp->icmp_type,
809 icmp->icmp_code);
810 } else {
811 len = ksnprintf(SNPARGS(proto, 0), "ICMP ");
812 }
813 len += ksnprintf(SNPARGS(proto, len), "%s",
814 inet_ntoa(ip->ip_src));
815 ksnprintf(SNPARGS(proto, len), " %s",
816 inet_ntoa(ip->ip_dst));
817 break;
818
819 default:
820 len = ksnprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
821 inet_ntoa(ip->ip_src));
822 ksnprintf(SNPARGS(proto, len), " %s",
823 inet_ntoa(ip->ip_dst));
824 break;
825 }
826
827 if (ip_off & (IP_MF | IP_OFFMASK)) {
828 ksnprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)",
829 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
830 offset << 3, (ip_off & IP_MF) ? "+" : "");
831 }
832 }
833
834 if (oif || m->m_pkthdr.rcvif) {
835 log(LOG_SECURITY | LOG_INFO,
836 "ipfw: %d %s %s %s via %s%s\n",
837 f ? f->rulenum : -1,
838 action, proto, oif ? "out" : "in",
839 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
840 fragment);
841 } else {
842 log(LOG_SECURITY | LOG_INFO,
843 "ipfw: %d %s %s [no if info]%s\n",
844 f ? f->rulenum : -1,
845 action, proto, fragment);
846 }
847
848 if (limit_reached) {
849 log(LOG_SECURITY | LOG_NOTICE,
850 "ipfw: limit %d reached on entry %d\n",
851 limit_reached, f ? f->rulenum : -1);
852 }
853 }
854
855 #undef SNPARGS
856
857 /*
858 * IMPORTANT: the hash function for dynamic rules must be commutative
859 * in source and destination (ip,port), because rules are bidirectional
860 * and we want to find both in the same bucket.
861 */
862 static __inline int
863 hash_packet(struct ipfw_flow_id *id)
864 {
865 uint32_t i;
866
867 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
868 i &= (curr_dyn_buckets - 1);
869 return i;
870 }
871
872 /**
873 * unlink a dynamic rule from a chain. prev is a pointer to
874 * the previous one, q is a pointer to the rule to delete,
875 * head is a pointer to the head of the queue.
876 * Modifies q and potentially also head.
877 */
878 #define UNLINK_DYN_RULE(prev, head, q) \
879 do { \
880 ipfw_dyn_rule *old_q = q; \
881 \
882 /* remove a refcount to the parent */ \
883 if (q->dyn_type == O_LIMIT) \
884 q->parent->count--; \
885 DPRINTF("-- unlink entry 0x%08x %d -> 0x%08x %d, %d left\n", \
886 q->id.src_ip, q->id.src_port, \
887 q->id.dst_ip, q->id.dst_port, dyn_count - 1); \
888 if (prev != NULL) \
889 prev->next = q = q->next; \
890 else \
891 head = q = q->next; \
892 KASSERT(dyn_count > 0, ("invalid dyn count %u\n", dyn_count)); \
893 dyn_count--; \
894 kfree(old_q, M_IPFW); \
895 } while (0)
896
897 #define TIME_LEQ(a, b) ((int)((a) - (b)) <= 0)
898
899 /**
900 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
901 *
902 * If keep_me == NULL, rules are deleted even if not expired,
903 * otherwise only expired rules are removed.
904 *
905 * The value of the second parameter is also used to point to identify
906 * a rule we absolutely do not want to remove (e.g. because we are
907 * holding a reference to it -- this is the case with O_LIMIT_PARENT
908 * rules). The pointer is only used for comparison, so any non-null
909 * value will do.
910 */
911 static void
912 remove_dyn_rule_locked(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
913 {
914 static uint32_t last_remove = 0; /* XXX */
915
916 #define FORCE (keep_me == NULL)
917
918 ipfw_dyn_rule *prev, *q;
919 int i, pass = 0, max_pass = 0, unlinked = 0;
920
921 if (ipfw_dyn_v == NULL || dyn_count == 0)
922 return;
923 /* do not expire more than once per second, it is useless */
924 if (!FORCE && last_remove == time_second)
925 return;
926 last_remove = time_second;
927
928 /*
929 * because O_LIMIT refer to parent rules, during the first pass only
930 * remove child and mark any pending LIMIT_PARENT, and remove
931 * them in a second pass.
932 */
933 next_pass:
934 for (i = 0; i < curr_dyn_buckets; i++) {
935 for (prev = NULL, q = ipfw_dyn_v[i]; q;) {
936 /*
937 * Logic can become complex here, so we split tests.
938 */
939 if (q == keep_me)
940 goto next;
941 if (rule != NULL && rule->stub != q->stub)
942 goto next; /* not the one we are looking for */
943 if (q->dyn_type == O_LIMIT_PARENT) {
944 /*
945 * handle parent in the second pass,
946 * record we need one.
947 */
948 max_pass = 1;
949 if (pass == 0)
950 goto next;
951 if (FORCE && q->count != 0) {
952 /* XXX should not happen! */
953 kprintf("OUCH! cannot remove rule, "
954 "count %d\n", q->count);
955 }
956 } else {
957 if (!FORCE && !TIME_LEQ(q->expire, time_second))
958 goto next;
959 }
960 unlinked = 1;
961 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
962 continue;
963 next:
964 prev = q;
965 q = q->next;
966 }
967 }
968 if (pass++ < max_pass)
969 goto next_pass;
970
971 if (unlinked)
972 ++dyn_buckets_gen;
973
974 #undef FORCE
975 }
976
977 /**
978 * lookup a dynamic rule.
979 */
980 static ipfw_dyn_rule *
981 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
982 struct tcphdr *tcp)
983 {
984 /*
985 * stateful ipfw extensions.
986 * Lookup into dynamic session queue
987 */
988 #define MATCH_REVERSE 0
989 #define MATCH_FORWARD 1
990 #define MATCH_NONE 2
991 #define MATCH_UNKNOWN 3
992 int i, dir = MATCH_NONE;
993 ipfw_dyn_rule *prev, *q=NULL;
994
995 if (ipfw_dyn_v == NULL)
996 goto done; /* not found */
997
998 i = hash_packet(pkt);
999 for (prev = NULL, q = ipfw_dyn_v[i]; q != NULL;) {
1000 if (q->dyn_type == O_LIMIT_PARENT)
1001 goto next;
1002
1003 if (TIME_LEQ(q->expire, time_second)) {
1004 /*
1005 * Entry expired; skip.
1006 * Let ipfw_tick() take care of it
1007 */
1008 goto next;
1009 }
1010
1011 if (pkt->proto == q->id.proto) {
1012 if (pkt->src_ip == q->id.src_ip &&
1013 pkt->dst_ip == q->id.dst_ip &&
1014 pkt->src_port == q->id.src_port &&
1015 pkt->dst_port == q->id.dst_port) {
1016 dir = MATCH_FORWARD;
1017 break;
1018 }
1019 if (pkt->src_ip == q->id.dst_ip &&
1020 pkt->dst_ip == q->id.src_ip &&
1021 pkt->src_port == q->id.dst_port &&
1022 pkt->dst_port == q->id.src_port) {
1023 dir = MATCH_REVERSE;
1024 break;
1025 }
1026 }
1027 next:
1028 prev = q;
1029 q = q->next;
1030 }
1031 if (q == NULL)
1032 goto done; /* q = NULL, not found */
1033
1034 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
1035 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
1036
1037 #define BOTH_SYN (TH_SYN | (TH_SYN << 8))
1038 #define BOTH_FIN (TH_FIN | (TH_FIN << 8))
1039
1040 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
1041 switch (q->state) {
1042 case TH_SYN: /* opening */
1043 q->expire = time_second + dyn_syn_lifetime;
1044 break;
1045
1046 case BOTH_SYN: /* move to established */
1047 case BOTH_SYN | TH_FIN : /* one side tries to close */
1048 case BOTH_SYN | (TH_FIN << 8) :
1049 if (tcp) {
1050 uint32_t ack = ntohl(tcp->th_ack);
1051
1052 #define _SEQ_GE(a, b) ((int)(a) - (int)(b) >= 0)
1053
1054 if (dir == MATCH_FORWARD) {
1055 if (q->ack_fwd == 0 ||
1056 _SEQ_GE(ack, q->ack_fwd))
1057 q->ack_fwd = ack;
1058 else /* ignore out-of-sequence */
1059 break;
1060 } else {
1061 if (q->ack_rev == 0 ||
1062 _SEQ_GE(ack, q->ack_rev))
1063 q->ack_rev = ack;
1064 else /* ignore out-of-sequence */
1065 break;
1066 }
1067 #undef _SEQ_GE
1068 }
1069 q->expire = time_second + dyn_ack_lifetime;
1070 break;
1071
1072 case BOTH_SYN | BOTH_FIN: /* both sides closed */
1073 KKASSERT(dyn_fin_lifetime < dyn_keepalive_period);
1074 q->expire = time_second + dyn_fin_lifetime;
1075 break;
1076
1077 default:
1078 #if 0
1079 /*
1080 * reset or some invalid combination, but can also
1081 * occur if we use keep-state the wrong way.
1082 */
1083 if ((q->state & ((TH_RST << 8) | TH_RST)) == 0)
1084 kprintf("invalid state: 0x%x\n", q->state);
1085 #endif
1086 KKASSERT(dyn_rst_lifetime < dyn_keepalive_period);
1087 q->expire = time_second + dyn_rst_lifetime;
1088 break;
1089 }
1090 } else if (pkt->proto == IPPROTO_UDP) {
1091 q->expire = time_second + dyn_udp_lifetime;
1092 } else {
1093 /* other protocols */
1094 q->expire = time_second + dyn_short_lifetime;
1095 }
1096 done:
1097 if (match_direction)
1098 *match_direction = dir;
1099 return q;
1100 }
1101
1102 static struct ip_fw *
1103 lookup_rule(struct ipfw_flow_id *pkt, int *match_direction, struct tcphdr *tcp,
1104 uint16_t len, int *deny)
1105 {
1106 struct ip_fw *rule = NULL;
1107 ipfw_dyn_rule *q;
1108 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
1109 uint32_t gen;
1110
1111 *deny = 0;
1112 gen = ctx->ipfw_gen;
1113
1114 lockmgr(&dyn_lock, LK_SHARED);
1115
1116 if (ctx->ipfw_gen != gen) {
1117 /*
1118 * Static rules had been change when we were waiting
1119 * for the dynamic hash table lock; deny this packet,
1120 * since it is _not_ known whether it is safe to keep
1121 * iterating the static rules.
1122 */
1123 *deny = 1;
1124 goto back;
1125 }
1126
1127 q = lookup_dyn_rule(pkt, match_direction, tcp);
1128 if (q == NULL) {
1129 rule = NULL;
1130 } else {
1131 rule = q->stub->rule[mycpuid];
1132 KKASSERT(rule->stub == q->stub && rule->cpuid == mycpuid);
1133
1134 /* XXX */
1135 q->pcnt++;
1136 q->bcnt += len;
1137 }
1138 back:
1139 lockmgr(&dyn_lock, LK_RELEASE);
1140 return rule;
1141 }
1142
1143 static void
1144 realloc_dynamic_table(void)
1145 {
1146 ipfw_dyn_rule **old_dyn_v;
1147 uint32_t old_curr_dyn_buckets;
1148
1149 KASSERT(dyn_buckets <= 65536 && (dyn_buckets & (dyn_buckets - 1)) == 0,
1150 ("invalid dyn_buckets %d\n", dyn_buckets));
1151
1152 /* Save the current buckets array for later error recovery */
1153 old_dyn_v = ipfw_dyn_v;
1154 old_curr_dyn_buckets = curr_dyn_buckets;
1155
1156 curr_dyn_buckets = dyn_buckets;
1157 for (;;) {
1158 ipfw_dyn_v = kmalloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
1159 M_IPFW, M_NOWAIT | M_ZERO);
1160 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
1161 break;
1162
1163 curr_dyn_buckets /= 2;
1164 if (curr_dyn_buckets <= old_curr_dyn_buckets &&
1165 old_dyn_v != NULL) {
1166 /*
1167 * Don't try allocating smaller buckets array, reuse
1168 * the old one, which alreay contains enough buckets
1169 */
1170 break;
1171 }
1172 }
1173
1174 if (ipfw_dyn_v != NULL) {
1175 if (old_dyn_v != NULL)
1176 kfree(old_dyn_v, M_IPFW);
1177 } else {
1178 /* Allocation failed, restore old buckets array */
1179 ipfw_dyn_v = old_dyn_v;
1180 curr_dyn_buckets = old_curr_dyn_buckets;
1181 }
1182
1183 if (ipfw_dyn_v != NULL)
1184 ++dyn_buckets_gen;
1185 }
1186
1187 /**
1188 * Install state of type 'type' for a dynamic session.
1189 * The hash table contains two type of rules:
1190 * - regular rules (O_KEEP_STATE)
1191 * - rules for sessions with limited number of sess per user
1192 * (O_LIMIT). When they are created, the parent is
1193 * increased by 1, and decreased on delete. In this case,
1194 * the third parameter is the parent rule and not the chain.
1195 * - "parent" rules for the above (O_LIMIT_PARENT).
1196 */
1197 static ipfw_dyn_rule *
1198 add_dyn_rule(struct ipfw_flow_id *id, uint8_t dyn_type, struct ip_fw *rule)
1199 {
1200 ipfw_dyn_rule *r;
1201 int i;
1202
1203 if (ipfw_dyn_v == NULL ||
1204 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
1205 realloc_dynamic_table();
1206 if (ipfw_dyn_v == NULL)
1207 return NULL; /* failed ! */
1208 }
1209 i = hash_packet(id);
1210
1211 r = kmalloc(sizeof(*r), M_IPFW, M_NOWAIT | M_ZERO);
1212 if (r == NULL) {
1213 kprintf ("sorry cannot allocate state\n");
1214 return NULL;
1215 }
1216
1217 /* increase refcount on parent, and set pointer */
1218 if (dyn_type == O_LIMIT) {
1219 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
1220
1221 if (parent->dyn_type != O_LIMIT_PARENT)
1222 panic("invalid parent");
1223 parent->count++;
1224 r->parent = parent;
1225 rule = parent->stub->rule[mycpuid];
1226 KKASSERT(rule->stub == parent->stub);
1227 }
1228 KKASSERT(rule->cpuid == mycpuid && rule->stub != NULL);
1229
1230 r->id = *id;
1231 r->expire = time_second + dyn_syn_lifetime;
1232 r->stub = rule->stub;
1233 r->dyn_type = dyn_type;
1234 r->pcnt = r->bcnt = 0;
1235 r->count = 0;
1236
1237 r->bucket = i;
1238 r->next = ipfw_dyn_v[i];
1239 ipfw_dyn_v[i] = r;
1240 dyn_count++;
1241 dyn_buckets_gen++;
1242 DPRINTF("-- add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
1243 dyn_type,
1244 r->id.src_ip, r->id.src_port,
1245 r->id.dst_ip, r->id.dst_port, dyn_count);
1246 return r;
1247 }
1248
1249 /**
1250 * lookup dynamic parent rule using pkt and rule as search keys.
1251 * If the lookup fails, then install one.
1252 */
1253 static ipfw_dyn_rule *
1254 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
1255 {
1256 ipfw_dyn_rule *q;
1257 int i;
1258
1259 if (ipfw_dyn_v) {
1260 i = hash_packet(pkt);
1261 for (q = ipfw_dyn_v[i]; q != NULL; q = q->next) {
1262 if (q->dyn_type == O_LIMIT_PARENT &&
1263 rule->stub == q->stub &&
1264 pkt->proto == q->id.proto &&
1265 pkt->src_ip == q->id.src_ip &&
1266 pkt->dst_ip == q->id.dst_ip &&
1267 pkt->src_port == q->id.src_port &&
1268 pkt->dst_port == q->id.dst_port) {
1269 q->expire = time_second + dyn_short_lifetime;
1270 DPRINTF("lookup_dyn_parent found 0x%p\n", q);
1271 return q;
1272 }
1273 }
1274 }
1275 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
1276 }
1277
1278 /**
1279 * Install dynamic state for rule type cmd->o.opcode
1280 *
1281 * Returns 1 (failure) if state is not installed because of errors or because
1282 * session limitations are enforced.
1283 */
1284 static int
1285 install_state_locked(struct ip_fw *rule, ipfw_insn_limit *cmd,
1286 struct ip_fw_args *args)
1287 {
1288 static int last_log; /* XXX */
1289
1290 ipfw_dyn_rule *q;
1291
1292 DPRINTF("-- install state type %d 0x%08x %u -> 0x%08x %u\n",
1293 cmd->o.opcode,
1294 args->f_id.src_ip, args->f_id.src_port,
1295 args->f_id.dst_ip, args->f_id.dst_port);
1296
1297 q = lookup_dyn_rule(&args->f_id, NULL, NULL);
1298 if (q != NULL) { /* should never occur */
1299 if (last_log != time_second) {
1300 last_log = time_second;
1301 kprintf(" install_state: entry already present, done\n");
1302 }
1303 return 0;
1304 }
1305
1306 if (dyn_count >= dyn_max) {
1307 /*
1308 * Run out of slots, try to remove any expired rule.
1309 */
1310 remove_dyn_rule_locked(NULL, (ipfw_dyn_rule *)1);
1311 if (dyn_count >= dyn_max) {
1312 if (last_log != time_second) {
1313 last_log = time_second;
1314 kprintf("install_state: "
1315 "Too many dynamic rules\n");
1316 }
1317 return 1; /* cannot install, notify caller */
1318 }
1319 }
1320
1321 switch (cmd->o.opcode) {
1322 case O_KEEP_STATE: /* bidir rule */
1323 if (add_dyn_rule(&args->f_id, O_KEEP_STATE, rule) == NULL)
1324 return 1;
1325 break;
1326
1327 case O_LIMIT: /* limit number of sessions */
1328 {
1329 uint16_t limit_mask = cmd->limit_mask;
1330 struct ipfw_flow_id id;
1331 ipfw_dyn_rule *parent;
1332
1333 DPRINTF("installing dyn-limit rule %d\n",
1334 cmd->conn_limit);
1335
1336 id.dst_ip = id.src_ip = 0;
1337 id.dst_port = id.src_port = 0;
1338 id.proto = args->f_id.proto;
1339
1340 if (limit_mask & DYN_SRC_ADDR)
1341 id.src_ip = args->f_id.src_ip;
1342 if (limit_mask & DYN_DST_ADDR)
1343 id.dst_ip = args->f_id.dst_ip;
1344 if (limit_mask & DYN_SRC_PORT)
1345 id.src_port = args->f_id.src_port;
1346 if (limit_mask & DYN_DST_PORT)
1347 id.dst_port = args->f_id.dst_port;
1348
1349 parent = lookup_dyn_parent(&id, rule);
1350 if (parent == NULL) {
1351 kprintf("add parent failed\n");
1352 return 1;
1353 }
1354
1355 if (parent->count >= cmd->conn_limit) {
1356 /*
1357 * See if we can remove some expired rule.
1358 */
1359 remove_dyn_rule_locked(rule, parent);
1360 if (parent->count >= cmd->conn_limit) {
1361 if (fw_verbose &&
1362 last_log != time_second) {
1363 last_log = time_second;
1364 log(LOG_SECURITY | LOG_DEBUG,
1365 "drop session, "
1366 "too many entries\n");
1367 }
1368 return 1;
1369 }
1370 }
1371 if (add_dyn_rule(&args->f_id, O_LIMIT,
1372 (struct ip_fw *)parent) == NULL)
1373 return 1;
1374 }
1375 break;
1376 default:
1377 kprintf("unknown dynamic rule type %u\n", cmd->o.opcode);
1378 return 1;
1379 }
1380 lookup_dyn_rule(&args->f_id, NULL, NULL); /* XXX just set lifetime */
1381 return 0;
1382 }
1383
1384 static int
1385 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
1386 struct ip_fw_args *args, int *deny)
1387 {
1388 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
1389 uint32_t gen;
1390 int ret = 0;
1391
1392 *deny = 0;
1393 gen = ctx->ipfw_gen;
1394
1395 lockmgr(&dyn_lock, LK_EXCLUSIVE);
1396 if (ctx->ipfw_gen != gen) {
1397 /* See the comment in lookup_rule() */
1398 *deny = 1;
1399 } else {
1400 ret = install_state_locked(rule, cmd, args);
1401 }
1402 lockmgr(&dyn_lock, LK_RELEASE);
1403
1404 return ret;
1405 }
1406
1407 /*
1408 * Transmit a TCP packet, containing either a RST or a keepalive.
1409 * When flags & TH_RST, we are sending a RST packet, because of a
1410 * "reset" action matched the packet.
1411 * Otherwise we are sending a keepalive, and flags & TH_
1412 */
1413 static void
1414 send_pkt(struct ipfw_flow_id *id, uint32_t seq, uint32_t ack, int flags)
1415 {
1416 struct mbuf *m;
1417 struct ip *ip;
1418 struct tcphdr *tcp;
1419 struct route sro; /* fake route */
1420
1421 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1422 if (m == NULL)
1423 return;
1424 m->m_pkthdr.rcvif = NULL;
1425 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
1426 m->m_data += max_linkhdr;
1427
1428 ip = mtod(m, struct ip *);
1429 bzero(ip, m->m_len);
1430 tcp = (struct tcphdr *)(ip + 1); /* no IP options */
1431 ip->ip_p = IPPROTO_TCP;
1432 tcp->th_off = 5;
1433
1434 /*
1435 * Assume we are sending a RST (or a keepalive in the reverse
1436 * direction), swap src and destination addresses and ports.
1437 */
1438 ip->ip_src.s_addr = htonl(id->dst_ip);
1439 ip->ip_dst.s_addr = htonl(id->src_ip);
1440 tcp->th_sport = htons(id->dst_port);
1441 tcp->th_dport = htons(id->src_port);
1442 if (flags & TH_RST) { /* we are sending a RST */
1443 if (flags & TH_ACK) {
1444 tcp->th_seq = htonl(ack);
1445 tcp->th_ack = htonl(0);
1446 tcp->th_flags = TH_RST;
1447 } else {
1448 if (flags & TH_SYN)
1449 seq++;
1450 tcp->th_seq = htonl(0);
1451 tcp->th_ack = htonl(seq);
1452 tcp->th_flags = TH_RST | TH_ACK;
1453 }
1454 } else {
1455 /*
1456 * We are sending a keepalive. flags & TH_SYN determines
1457 * the direction, forward if set, reverse if clear.
1458 * NOTE: seq and ack are always assumed to be correct
1459 * as set by the caller. This may be confusing...
1460 */
1461 if (flags & TH_SYN) {
1462 /*
1463 * we have to rewrite the correct addresses!
1464 */
1465 ip->ip_dst.s_addr = htonl(id->dst_ip);
1466 ip->ip_src.s_addr = htonl(id->src_ip);
1467 tcp->th_dport = htons(id->dst_port);
1468 tcp->th_sport = htons(id->src_port);
1469 }
1470 tcp->th_seq = htonl(seq);
1471 tcp->th_ack = htonl(ack);
1472 tcp->th_flags = TH_ACK;
1473 }
1474
1475 /*
1476 * set ip_len to the payload size so we can compute
1477 * the tcp checksum on the pseudoheader
1478 * XXX check this, could save a couple of words ?
1479 */
1480 ip->ip_len = htons(sizeof(struct tcphdr));
1481 tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
1482
1483 /*
1484 * now fill fields left out earlier
1485 */
1486 ip->ip_ttl = ip_defttl;
1487 ip->ip_len = m->m_pkthdr.len;
1488
1489 bzero(&sro, sizeof(sro));
1490 ip_rtaddr(ip->ip_dst, &sro);
1491
1492 m->m_pkthdr.fw_flags |= IPFW_MBUF_GENERATED;
1493 ip_output(m, NULL, &sro, 0, NULL, NULL);
1494 if (sro.ro_rt)
1495 RTFREE(sro.ro_rt);
1496 }
1497
1498 /*
1499 * sends a reject message, consuming the mbuf passed as an argument.
1500 */
1501 static void
1502 send_reject(struct ip_fw_args *args, int code, int offset, int ip_len)
1503 {
1504 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
1505 /* We need the IP header in host order for icmp_error(). */
1506 if (args->eh != NULL) {
1507 struct ip *ip = mtod(args->m, struct ip *);
1508
1509 ip->ip_len = ntohs(ip->ip_len);
1510 ip->ip_off = ntohs(ip->ip_off);
1511 }
1512 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
1513 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
1514 struct tcphdr *const tcp =
1515 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
1516
1517 if ((tcp->th_flags & TH_RST) == 0) {
1518 send_pkt(&args->f_id, ntohl(tcp->th_seq),
1519 ntohl(tcp->th_ack), tcp->th_flags | TH_RST);
1520 }
1521 m_freem(args->m);
1522 } else {
1523 m_freem(args->m);
1524 }
1525 args->m = NULL;
1526 }
1527
1528 /**
1529 *
1530 * Given an ip_fw *, lookup_next_rule will return a pointer
1531 * to the next rule, which can be either the jump
1532 * target (for skipto instructions) or the next one in the list (in
1533 * all other cases including a missing jump target).
1534 * The result is also written in the "next_rule" field of the rule.
1535 * Backward jumps are not allowed, so start looking from the next
1536 * rule...
1537 *
1538 * This never returns NULL -- in case we do not have an exact match,
1539 * the next rule is returned. When the ruleset is changed,
1540 * pointers are flushed so we are always correct.
1541 */
1542
1543 static struct ip_fw *
1544 lookup_next_rule(struct ip_fw *me)
1545 {
1546 struct ip_fw *rule = NULL;
1547 ipfw_insn *cmd;
1548
1549 /* look for action, in case it is a skipto */
1550 cmd = ACTION_PTR(me);
1551 if (cmd->opcode == O_LOG)
1552 cmd += F_LEN(cmd);
1553 if (cmd->opcode == O_SKIPTO) {
1554 for (rule = me->next; rule; rule = rule->next) {
1555 if (rule->rulenum >= cmd->arg1)
1556 break;
1557 }
1558 }
1559 if (rule == NULL) /* failure or not a skipto */
1560 rule = me->next;
1561 me->next_rule = rule;
1562 return rule;
1563 }
1564
1565 static int
1566 _ipfw_match_uid(const struct ipfw_flow_id *fid, struct ifnet *oif,
1567 enum ipfw_opcodes opcode, uid_t uid)
1568 {
1569 struct in_addr src_ip, dst_ip;
1570 struct inpcbinfo *pi;
1571 int wildcard;
1572 struct inpcb *pcb;
1573
1574 if (fid->proto == IPPROTO_TCP) {
1575 wildcard = 0;
1576 pi = &tcbinfo[mycpuid];
1577 } else if (fid->proto == IPPROTO_UDP) {
1578 wildcard = 1;
1579 pi = &udbinfo;
1580 } else {
1581 return 0;
1582 }
1583
1584 /*
1585 * Values in 'fid' are in host byte order
1586 */
1587 dst_ip.s_addr = htonl(fid->dst_ip);
1588 src_ip.s_addr = htonl(fid->src_ip);
1589 if (oif) {
1590 pcb = in_pcblookup_hash(pi,
1591 dst_ip, htons(fid->dst_port),
1592 src_ip, htons(fid->src_port),
1593 wildcard, oif);
1594 } else {
1595 pcb = in_pcblookup_hash(pi,
1596 src_ip, htons(fid->src_port),
1597 dst_ip, htons(fid->dst_port),
1598 wildcard, NULL);
1599 }
1600 if (pcb == NULL || pcb->inp_socket == NULL)
1601 return 0;
1602
1603 if (opcode == O_UID) {
1604 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b))
1605 return !socheckuid(pcb->inp_socket, uid);
1606 #undef socheckuid
1607 } else {
1608 return groupmember(uid, pcb->inp_socket->so_cred);
1609 }
1610 }
1611
1612 static int
1613 ipfw_match_uid(const struct ipfw_flow_id *fid, struct ifnet *oif,
1614 enum ipfw_opcodes opcode, uid_t uid, int *deny)
1615 {
1616 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
1617 uint32_t gen;
1618 int match = 0;
1619
1620 *deny = 0;
1621 gen = ctx->ipfw_gen;
1622
1623 get_mplock();
1624 if (gen != ctx->ipfw_gen) {
1625 /* See the comment in lookup_rule() */
1626 *deny = 1;
1627 } else {
1628 match = _ipfw_match_uid(fid, oif, opcode, uid);
1629 }
1630 rel_mplock();
1631 return match;
1632 }
1633
1634 /*
1635 * The main check routine for the firewall.
1636 *
1637 * All arguments are in args so we can modify them and return them
1638 * back to the caller.
1639 *
1640 * Parameters:
1641 *
1642 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
1643 * Starts with the IP header.
1644 * args->eh (in) Mac header if present, or NULL for layer3 packet.
1645 * args->oif Outgoing interface, or NULL if packet is incoming.
1646 * The incoming interface is in the mbuf. (in)
1647 *
1648 * args->rule Pointer to the last matching rule (in/out)
1649 * args->f_id Addresses grabbed from the packet (out)
1650 *
1651 * Return value:
1652 *
1653 * If the packet was denied/rejected and has been dropped, *m is equal
1654 * to NULL upon return.
1655 *
1656 * IP_FW_DENY the packet must be dropped.
1657 * IP_FW_PASS The packet is to be accepted and routed normally.
1658 * IP_FW_DIVERT Divert the packet to port (args->cookie)
1659 * IP_FW_TEE Tee the packet to port (args->cookie)
1660 * IP_FW_DUMMYNET Send the packet to pipe/queue (args->cookie)
1661 */
1662
1663 static int
1664 ipfw_chk(struct ip_fw_args *args)
1665 {
1666 /*
1667 * Local variables hold state during the processing of a packet.
1668 *
1669 * IMPORTANT NOTE: to speed up the processing of rules, there
1670 * are some assumption on the values of the variables, which
1671 * are documented here. Should you change them, please check
1672 * the implementation of the various instructions to make sure
1673 * that they still work.
1674 *
1675 * args->eh The MAC header. It is non-null for a layer2
1676 * packet, it is NULL for a layer-3 packet.
1677 *
1678 * m | args->m Pointer to the mbuf, as received from the caller.
1679 * It may change if ipfw_chk() does an m_pullup, or if it
1680 * consumes the packet because it calls send_reject().
1681 * XXX This has to change, so that ipfw_chk() never modifies
1682 * or consumes the buffer.
1683 * ip is simply an alias of the value of m, and it is kept
1684 * in sync with it (the packet is supposed to start with
1685 * the ip header).
1686 */
1687 struct mbuf *m = args->m;
1688 struct ip *ip = mtod(m, struct ip *);
1689
1690 /*
1691 * oif | args->oif If NULL, ipfw_chk has been called on the
1692 * inbound path (ether_input, ip_input).
1693 * If non-NULL, ipfw_chk has been called on the outbound path
1694 * (ether_output, ip_output).
1695 */
1696 struct ifnet *oif = args->oif;
1697
1698 struct ip_fw *f = NULL; /* matching rule */
1699 int retval = IP_FW_PASS;
1700 struct m_tag *mtag;
1701 struct divert_info *divinfo;
1702
1703 /*
1704 * hlen The length of the IPv4 header.
1705 * hlen >0 means we have an IPv4 packet.
1706 */
1707 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
1708
1709 /*
1710 * offset The offset of a fragment. offset != 0 means that
1711 * we have a fragment at this offset of an IPv4 packet.
1712 * offset == 0 means that (if this is an IPv4 packet)
1713 * this is the first or only fragment.
1714 */
1715 u_short offset = 0;
1716
1717 /*
1718 * Local copies of addresses. They are only valid if we have
1719 * an IP packet.
1720 *
1721 * proto The protocol. Set to 0 for non-ip packets,
1722 * or to the protocol read from the packet otherwise.
1723 * proto != 0 means that we have an IPv4 packet.
1724 *
1725 * src_port, dst_port port numbers, in HOST format. Only
1726 * valid for TCP and UDP packets.
1727 *
1728 * src_ip, dst_ip ip addresses, in NETWORK format.
1729 * Only valid for IPv4 packets.
1730 */
1731 uint8_t proto;
1732 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */
1733 struct in_addr src_ip, dst_ip; /* NOTE: network format */
1734 uint16_t ip_len = 0;
1735
1736 /*
1737 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
1738 * MATCH_NONE when checked and not matched (dyn_f = NULL),
1739 * MATCH_FORWARD or MATCH_REVERSE otherwise (dyn_f != NULL)
1740 */
1741 int dyn_dir = MATCH_UNKNOWN;
1742 struct ip_fw *dyn_f = NULL;
1743 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
1744
1745 if (m->m_pkthdr.fw_flags & IPFW_MBUF_GENERATED)
1746 return IP_FW_PASS; /* accept */
1747
1748 if (args->eh == NULL || /* layer 3 packet */
1749 (m->m_pkthdr.len >= sizeof(struct ip) &&
1750 ntohs(args->eh->ether_type) == ETHERTYPE_IP))
1751 hlen = ip->ip_hl << 2;
1752
1753 /*
1754 * Collect parameters into local variables for faster matching.
1755 */
1756 if (hlen == 0) { /* do not grab addresses for non-ip pkts */
1757 proto = args->f_id.proto = 0; /* mark f_id invalid */
1758 goto after_ip_checks;
1759 }
1760
1761 proto = args->f_id.proto = ip->ip_p;
1762 src_ip = ip->ip_src;
1763 dst_ip = ip->ip_dst;
1764 if (args->eh != NULL) { /* layer 2 packets are as on the wire */
1765 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1766 ip_len = ntohs(ip->ip_len);
1767 } else {
1768 offset = ip->ip_off & IP_OFFMASK;
1769 ip_len = ip->ip_len;
1770 }
1771
1772 #define PULLUP_TO(len) \
1773 do { \
1774 if (m->m_len < (len)) { \
1775 args->m = m = m_pullup(m, (len));\
1776 if (m == NULL) \
1777 goto pullup_failed; \
1778 ip = mtod(m, struct ip *); \
1779 } \
1780 } while (0)
1781
1782 if (offset == 0) {
1783 switch (proto) {
1784 case IPPROTO_TCP:
1785 {
1786 struct tcphdr *tcp;
1787
1788 PULLUP_TO(hlen + sizeof(struct tcphdr));
1789 tcp = L3HDR(struct tcphdr, ip);
1790 dst_port = tcp->th_dport;
1791 src_port = tcp->th_sport;
1792 args->f_id.flags = tcp->th_flags;
1793 }
1794 break;
1795
1796 case IPPROTO_UDP:
1797 {
1798 struct udphdr *udp;
1799
1800 PULLUP_TO(hlen + sizeof(struct udphdr));
1801 udp = L3HDR(struct udphdr, ip);
1802 dst_port = udp->uh_dport;
1803 src_port = udp->uh_sport;
1804 }
1805 break;
1806
1807 case IPPROTO_ICMP:
1808 PULLUP_TO(hlen + 4); /* type, code and checksum. */
1809 args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type;
1810 break;
1811
1812 default:
1813 break;
1814 }
1815 }
1816
1817 #undef PULLUP_TO
1818
1819 args->f_id.src_ip = ntohl(src_ip.s_addr);
1820 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1821 args->f_id.src_port = src_port = ntohs(src_port);
1822 args->f_id.dst_port = dst_port = ntohs(dst_port);
1823
1824 after_ip_checks:
1825 if (args->rule) {
1826 /*
1827 * Packet has already been tagged. Look for the next rule
1828 * to restart processing.
1829 *
1830 * If fw_one_pass != 0 then just accept it.
1831 * XXX should not happen here, but optimized out in
1832 * the caller.
1833 */
1834 if (fw_one_pass)
1835 return IP_FW_PASS;
1836
1837 /* This rule is being/has been flushed */
1838 if (ipfw_flushing)
1839 return IP_FW_DENY;
1840
1841 KASSERT(args->rule->cpuid == mycpuid,
1842 ("rule used on cpu%d\n", mycpuid));
1843
1844 /* This rule was deleted */
1845 if (args->rule->rule_flags & IPFW_RULE_F_INVALID)
1846 return IP_FW_DENY;
1847
1848 f = args->rule->next_rule;
1849 if (f == NULL)
1850 f = lookup_next_rule(args->rule);
1851 } else {
1852 /*
1853 * Find the starting rule. It can be either the first
1854 * one, or the one after divert_rule if asked so.
1855 */
1856 int skipto;
1857
1858 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
1859 if (mtag != NULL) {
1860 divinfo = m_tag_data(mtag);
1861 skipto = divinfo->skipto;
1862 } else {
1863 skipto = 0;
1864 }
1865
1866 f = ctx->ipfw_layer3_chain;
1867 if (args->eh == NULL && skipto != 0) {
1868 /* No skipto during rule flushing */
1869 if (ipfw_flushing)
1870 return IP_FW_DENY;
1871
1872 if (skipto >= IPFW_DEFAULT_RULE)
1873 return IP_FW_DENY; /* invalid */
1874
1875 while (f && f->rulenum <= skipto)
1876 f = f->next;
1877 if (f == NULL) /* drop packet */
1878 return IP_FW_DENY;
1879 } else if (ipfw_flushing) {
1880 /* Rules are being flushed; skip to default rule */
1881 f = ctx->ipfw_default_rule;
1882 }
1883 }
1884 if ((mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL)
1885 m_tag_delete(m, mtag);
1886
1887 /*
1888 * Now scan the rules, and parse microinstructions for each rule.
1889 */
1890 for (; f; f = f->next) {
1891 int l, cmdlen;
1892 ipfw_insn *cmd;
1893 int skip_or; /* skip rest of OR block */
1894
1895 again:
1896 if (ctx->ipfw_set_disable & (1 << f->set))
1897 continue;
1898
1899 skip_or = 0;
1900 for (l = f->cmd_len, cmd = f->cmd; l > 0;
1901 l -= cmdlen, cmd += cmdlen) {
1902 int match, deny;
1903
1904 /*
1905 * check_body is a jump target used when we find a
1906 * CHECK_STATE, and need to jump to the body of
1907 * the target rule.
1908 */
1909
1910 check_body:
1911 cmdlen = F_LEN(cmd);
1912 /*
1913 * An OR block (insn_1 || .. || insn_n) has the
1914 * F_OR bit set in all but the last instruction.
1915 * The first match will set "skip_or", and cause
1916 * the following instructions to be skipped until
1917 * past the one with the F_OR bit clear.
1918 */
1919 if (skip_or) { /* skip this instruction */
1920 if ((cmd->len & F_OR) == 0)
1921 skip_or = 0; /* next one is good */
1922 continue;
1923 }
1924 match = 0; /* set to 1 if we succeed */
1925
1926 switch (cmd->opcode) {
1927 /*
1928 * The first set of opcodes compares the packet's
1929 * fields with some pattern, setting 'match' if a
1930 * match is found. At the end of the loop there is
1931 * logic to deal with F_NOT and F_OR flags associated
1932 * with the opcode.
1933 */
1934 case O_NOP:
1935 match = 1;
1936 break;
1937
1938 case O_FORWARD_MAC:
1939 kprintf("ipfw: opcode %d unimplemented\n",
1940 cmd->opcode);
1941 break;
1942
1943 case O_GID:
1944 case O_UID:
1945 /*
1946 * We only check offset == 0 && proto != 0,
1947 * as this ensures that we have an IPv4
1948 * packet with the ports info.
1949 */
1950 if (offset!=0)
1951 break;
1952
1953 match = ipfw_match_uid(&args->f_id, oif,
1954 cmd->opcode,
1955 (uid_t)((ipfw_insn_u32 *)cmd)->d[0],
1956 &deny);
1957 if (deny)
1958 return IP_FW_DENY;
1959 break;
1960
1961 case O_RECV:
1962 match = iface_match(m->m_pkthdr.rcvif,
1963 (ipfw_insn_if *)cmd);
1964 break;
1965
1966 case O_XMIT:
1967 match = iface_match(oif, (ipfw_insn_if *)cmd);
1968 break;
1969
1970 case O_VIA:
1971 match = iface_match(oif ? oif :
1972 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1973 break;
1974
1975 case O_MACADDR2:
1976 if (args->eh != NULL) { /* have MAC header */
1977 uint32_t *want = (uint32_t *)
1978 ((ipfw_insn_mac *)cmd)->addr;
1979 uint32_t *mask = (uint32_t *)
1980 ((ipfw_insn_mac *)cmd)->mask;
1981 uint32_t *hdr = (uint32_t *)args->eh;
1982
1983 match =
1984 (want[0] == (hdr[0] & mask[0]) &&
1985 want[1] == (hdr[1] & mask[1]) &&
1986 want[2] == (hdr[2] & mask[2]));
1987 }
1988 break;
1989
1990 case O_MAC_TYPE:
1991 if (args->eh != NULL) {
1992 uint16_t t =
1993 ntohs(args->eh->ether_type);
1994 uint16_t *p =
1995 ((ipfw_insn_u16 *)cmd)->ports;
1996 int i;
1997
1998 /* Special vlan handling */
1999 if (m->m_flags & M_VLANTAG)
2000 t = ETHERTYPE_VLAN;
2001
2002 for (i = cmdlen - 1; !match && i > 0;
2003 i--, p += 2) {
2004 match =
2005 (t >= p[0] && t <= p[1]);
2006 }
2007 }
2008 break;
2009
2010 case O_FRAG:
2011 match = (hlen > 0 && offset != 0);
2012 break;
2013
2014 case O_IN: /* "out" is "not in" */
2015 match = (oif == NULL);
2016 break;
2017
2018 case O_LAYER2:
2019 match = (args->eh != NULL);
2020 break;
2021
2022 case O_PROTO:
2023 /*
2024 * We do not allow an arg of 0 so the
2025 * check of "proto" only suffices.
2026 */
2027 match = (proto == cmd->arg1);
2028 break;
2029
2030 case O_IP_SRC:
2031 match = (hlen > 0 &&
2032 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
2033 src_ip.s_addr);
2034 break;
2035
2036 case O_IP_SRC_MASK:
2037 match = (hlen > 0 &&
2038 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
2039 (src_ip.s_addr &
2040 ((ipfw_insn_ip *)cmd)->mask.s_addr));
2041 break;
2042
2043 case O_IP_SRC_ME:
2044 if (hlen > 0) {
2045 struct ifnet *tif;
2046
2047 tif = INADDR_TO_IFP(&src_ip);
2048 match = (tif != NULL);
2049 }
2050 break;
2051
2052 case O_IP_DST_SET:
2053 case O_IP_SRC_SET:
2054 if (hlen > 0) {
2055 uint32_t *d = (uint32_t *)(cmd + 1);
2056 uint32_t addr =
2057 cmd->opcode == O_IP_DST_SET ?
2058 args->f_id.dst_ip :
2059 args->f_id.src_ip;
2060
2061 if (addr < d[0])
2062 break;
2063 addr -= d[0]; /* subtract base */
2064 match =
2065 (addr < cmd->arg1) &&
2066 (d[1 + (addr >> 5)] &
2067 (1 << (addr & 0x1f)));
2068 }
2069 break;
2070
2071 case O_IP_DST:
2072 match = (hlen > 0 &&
2073 ((ipfw_insn_ip *)cmd)->addr.s_addr ==
2074 dst_ip.s_addr);
2075 break;
2076
2077 case O_IP_DST_MASK:
2078 match = (hlen > 0) &&
2079 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
2080 (dst_ip.s_addr &
2081 ((ipfw_insn_ip *)cmd)->mask.s_addr));
2082 break;
2083
2084 case O_IP_DST_ME:
2085 if (hlen > 0) {
2086 struct ifnet *tif;
2087
2088 tif = INADDR_TO_IFP(&dst_ip);
2089 match = (tif != NULL);
2090 }
2091 break;
2092
2093 case O_IP_SRCPORT:
2094 case O_IP_DSTPORT:
2095 /*
2096 * offset == 0 && proto != 0 is enough
2097 * to guarantee that we have an IPv4
2098 * packet with port info.
2099 */
2100 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
2101 && offset == 0) {
2102 uint16_t x =
2103 (cmd->opcode == O_IP_SRCPORT) ?
2104 src_port : dst_port ;
2105 uint16_t *p =
2106 ((ipfw_insn_u16 *)cmd)->ports;
2107 int i;
2108
2109 for (i = cmdlen - 1; !match && i > 0;
2110 i--, p += 2) {
2111 match =
2112 (x >= p[0] && x <= p[1]);
2113 }
2114 }
2115 break;
2116
2117 case O_ICMPTYPE:
2118 match = (offset == 0 && proto==IPPROTO_ICMP &&
2119 icmptype_match(ip, (ipfw_insn_u32 *)cmd));
2120 break;
2121
2122 case O_IPOPT:
2123 match = (hlen > 0 && ipopts_match(ip, cmd));
2124 break;
2125
2126 case O_IPVER:
2127 match = (hlen > 0 && cmd->arg1 == ip->ip_v);
2128 break;
2129
2130 case O_IPTTL:
2131 match = (hlen > 0 && cmd->arg1 == ip->ip_ttl);
2132 break;
2133
2134 case O_IPID:
2135 match = (hlen > 0 &&
2136 cmd->arg1 == ntohs(ip->ip_id));
2137 break;
2138
2139 case O_IPLEN:
2140 match = (hlen > 0 && cmd->arg1 == ip_len);
2141 break;
2142
2143 case O_IPPRECEDENCE:
2144 match = (hlen > 0 &&
2145 (cmd->arg1 == (ip->ip_tos & 0xe0)));
2146 break;
2147
2148 case O_IPTOS:
2149 match = (hlen > 0 &&
2150 flags_match(cmd, ip->ip_tos));
2151 break;
2152
2153 case O_TCPFLAGS:
2154 match = (proto == IPPROTO_TCP && offset == 0 &&
2155 flags_match(cmd,
2156 L3HDR(struct tcphdr,ip)->th_flags));
2157 break;
2158
2159 case O_TCPOPTS:
2160 match = (proto == IPPROTO_TCP && offset == 0 &&
2161 tcpopts_match(ip, cmd));
2162 break;
2163
2164 case O_TCPSEQ:
2165 match = (proto == IPPROTO_TCP && offset == 0 &&
2166 ((ipfw_insn_u32 *)cmd)->d[0] ==
2167 L3HDR(struct tcphdr,ip)->th_seq);
2168 break;
2169
2170 case O_TCPACK:
2171 match = (proto == IPPROTO_TCP && offset == 0 &&
2172 ((ipfw_insn_u32 *)cmd)->d[0] ==
2173 L3HDR(struct tcphdr,ip)->th_ack);
2174 break;
2175
2176 case O_TCPWIN:
2177 match = (proto == IPPROTO_TCP && offset == 0 &&
2178 cmd->arg1 ==
2179 L3HDR(struct tcphdr,ip)->th_win);
2180 break;
2181
2182 case O_ESTAB:
2183 /* reject packets which have SYN only */
2184 /* XXX should i also check for TH_ACK ? */
2185 match = (proto == IPPROTO_TCP && offset == 0 &&
2186 (L3HDR(struct tcphdr,ip)->th_flags &
2187 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
2188 break;
2189
2190 case O_LOG:
2191 if (fw_verbose)
2192 ipfw_log(f, hlen, args->eh, m, oif);
2193 match = 1;
2194 break;
2195
2196 case O_PROB:
2197 match = (krandom() <
2198 ((ipfw_insn_u32 *)cmd)->d[0]);
2199 break;
2200
2201 /*
2202 * The second set of opcodes represents 'actions',
2203 * i.e. the terminal part of a rule once the packet
2204 * matches all previous patterns.
2205 * Typically there is only one action for each rule,
2206 * and the opcode is stored at the end of the rule
2207 * (but there are exceptions -- see below).
2208 *
2209 * In general, here we set retval and terminate the
2210 * outer loop (would be a 'break 3' in some language,
2211 * but we need to do a 'goto done').
2212 *
2213 * Exceptions:
2214 * O_COUNT and O_SKIPTO actions:
2215 * instead of terminating, we jump to the next rule
2216 * ('goto next_rule', equivalent to a 'break 2'),
2217 * or to the SKIPTO target ('goto again' after
2218 * having set f, cmd and l), respectively.
2219 *
2220 * O_LIMIT and O_KEEP_STATE: these opcodes are
2221 * not real 'actions', and are stored right
2222 * before the 'action' part of the rule.
2223 * These opcodes try to install an entry in the
2224 * state tables; if successful, we continue with
2225 * the next opcode (match=1; break;), otherwise
2226 * the packet must be dropped ('goto done' after
2227 * setting retval). If static rules are changed
2228 * during the state installation, the packet will
2229 * be dropped and rule's stats will not beupdated
2230 * ('return IP_FW_DENY').
2231 *
2232 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
2233 * cause a lookup of the state table, and a jump
2234 * to the 'action' part of the parent rule
2235 * ('goto check_body') if an entry is found, or
2236 * (CHECK_STATE only) a jump to the next rule if
2237 * the entry is not found ('goto next_rule').
2238 * The result of the lookup is cached to make
2239 * further instances of these opcodes are
2240 * effectively NOPs. If static rules are changed
2241 * during the state looking up, the packet will
2242 * be dropped and rule's stats will not be updated
2243 * ('return IP_FW_DENY').
2244 */
2245 case O_LIMIT:
2246 case O_KEEP_STATE:
2247 if (!(f->rule_flags & IPFW_RULE_F_STATE)) {
2248 kprintf("%s rule (%d) is not ready "
2249 "on cpu%d\n",
2250 cmd->opcode == O_LIMIT ?
2251 "limit" : "keep state",
2252 f->rulenum, f->cpuid);
2253 goto next_rule;
2254 }
2255 if (install_state(f,
2256 (ipfw_insn_limit *)cmd, args, &deny)) {
2257 if (deny)
2258 return IP_FW_DENY;
2259
2260 retval = IP_FW_DENY;
2261 goto done; /* error/limit violation */
2262 }
2263 if (deny)
2264 return IP_FW_DENY;
2265 match = 1;
2266 break;
2267
2268 case O_PROBE_STATE:
2269 case O_CHECK_STATE:
2270 /*
2271 * dynamic rules are checked at the first
2272 * keep-state or check-state occurrence,
2273 * with the result being stored in dyn_dir.
2274 * The compiler introduces a PROBE_STATE
2275 * instruction for us when we have a
2276 * KEEP_STATE (because PROBE_STATE needs
2277 * to be run first).
2278 */
2279 if (dyn_dir == MATCH_UNKNOWN) {
2280 dyn_f = lookup_rule(&args->f_id,
2281 &dyn_dir,
2282 proto == IPPROTO_TCP ?
2283 L3HDR(struct tcphdr, ip) : NULL,
2284 ip_len, &deny);
2285 if (deny)
2286 return IP_FW_DENY;
2287 if (dyn_f != NULL) {
2288 /*
2289 * Found a rule from a dynamic
2290 * entry; jump to the 'action'
2291 * part of the rule.
2292 */
2293 f = dyn_f;
2294 cmd = ACTION_PTR(f);
2295 l = f->cmd_len - f->act_ofs;
2296 goto check_body;
2297 }
2298 }
2299 /*
2300 * Dynamic entry not found. If CHECK_STATE,
2301 * skip to next rule, if PROBE_STATE just
2302 * ignore and continue with next opcode.
2303 */
2304 if (cmd->opcode == O_CHECK_STATE)
2305 goto next_rule;
2306 else if (!(f->rule_flags & IPFW_RULE_F_STATE))
2307 goto next_rule; /* not ready yet */
2308 match = 1;
2309 break;
2310
2311 case O_ACCEPT:
2312 retval = IP_FW_PASS; /* accept */
2313 goto done;
2314
2315 case O_PIPE:
2316 case O_QUEUE:
2317 args->rule = f; /* report matching rule */
2318 args->cookie = cmd->arg1;
2319 retval = IP_FW_DUMMYNET;
2320 goto done;
2321
2322 case O_DIVERT:
2323 case O_TEE:
2324 if (args->eh) /* not on layer 2 */
2325 break;
2326
2327 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT,
2328 sizeof(*divinfo), MB_DONTWAIT);
2329 if (mtag == NULL) {
2330 retval = IP_FW_DENY;
2331 goto done;
2332 }
2333 divinfo = m_tag_data(mtag);
2334
2335 divinfo->skipto = f->rulenum;
2336 divinfo->port = cmd->arg1;
2337 divinfo->tee = (cmd->opcode == O_TEE);
2338 m_tag_prepend(m, mtag);
2339
2340 args->cookie = cmd->arg1;
2341 retval = (cmd->opcode == O_DIVERT) ?
2342 IP_FW_DIVERT : IP_FW_TEE;
2343 goto done;
2344
2345 case O_COUNT:
2346 case O_SKIPTO:
2347 f->pcnt++; /* update stats */
2348 f->bcnt += ip_len;
2349 f->timestamp = time_second;
2350 if (cmd->opcode == O_COUNT)
2351 goto next_rule;
2352 /* handle skipto */
2353 if (f->next_rule == NULL)
2354 lookup_next_rule(f);
2355 f = f->next_rule;
2356 goto again;
2357
2358 case O_REJECT:
2359 /*
2360 * Drop the packet and send a reject notice
2361 * if the packet is not ICMP (or is an ICMP
2362 * query), and it is not multicast/broadcast.
2363 */
2364 if (hlen > 0 &&
2365 (proto != IPPROTO_ICMP ||
2366 is_icmp_query(ip)) &&
2367 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2368 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2369 /*
2370 * Update statistics before the possible
2371 * blocking 'send_reject'
2372 */
2373 f->pcnt++;
2374 f->bcnt += ip_len;
2375 f->timestamp = time_second;
2376
2377 send_reject(args, cmd->arg1,
2378 offset,ip_len);
2379 m = args->m;
2380
2381 /*
2382 * Return directly here, rule stats
2383 * have been updated above.
2384 */
2385 return IP_FW_DENY;
2386 }
2387 /* FALLTHROUGH */
2388 case O_DENY:
2389 retval = IP_FW_DENY;
2390 goto done;
2391
2392 case O_FORWARD_IP:
2393 if (args->eh) /* not valid on layer2 pkts */
2394 break;
2395 if (!dyn_f || dyn_dir == MATCH_FORWARD) {
2396 struct sockaddr_in *sin;
2397
2398 mtag = m_tag_get(PACKET_TAG_IPFORWARD,
2399 sizeof(*sin), MB_DONTWAIT);
2400 if (mtag == NULL) {
2401 retval = IP_FW_DENY;
2402 goto done;
2403 }
2404 sin = m_tag_data(mtag);
2405
2406 /* Structure copy */
2407 *sin = ((ipfw_insn_sa *)cmd)->sa;
2408
2409 m_tag_prepend(m, mtag);
2410 m->m_pkthdr.fw_flags |=
2411 IPFORWARD_MBUF_TAGGED;
2412 }
2413 retval = IP_FW_PASS;
2414 goto done;
2415
2416 default:
2417 panic("-- unknown opcode %d\n", cmd->opcode);
2418 } /* end of switch() on opcodes */
2419
2420 if (cmd->len & F_NOT)
2421 match = !match;
2422
2423 if (match) {
2424 if (cmd->len & F_OR)
2425 skip_or = 1;
2426 } else {
2427 if (!(cmd->len & F_OR)) /* not an OR block, */
2428 break; /* try next rule */
2429 }
2430
2431 } /* end of inner for, scan opcodes */
2432
2433 next_rule:; /* try next rule */
2434
2435 } /* end of outer for, scan rules */
2436 kprintf("+++ ipfw: ouch!, skip past end of rules, denying packet\n");
2437 return IP_FW_DENY;
2438
2439 done:
2440 /* Update statistics */
2441 f->pcnt++;
2442 f->bcnt += ip_len;
2443 f->timestamp = time_second;
2444 return retval;
2445
2446 pullup_failed:
2447 if (fw_verbose)
2448 kprintf("pullup failed\n");
2449 return IP_FW_DENY;
2450 }
2451
2452 static void
2453 ipfw_dummynet_io(struct mbuf *m, int pipe_nr, int dir, struct ip_fw_args *fwa)
2454 {
2455 struct m_tag *mtag;
2456 struct dn_pkt *pkt;
2457 ipfw_insn *cmd;
2458 const struct ipfw_flow_id *id;
2459 struct dn_flow_id *fid;
2460
2461 M_ASSERTPKTHDR(m);
2462
2463 mtag = m_tag_get(PACKET_TAG_DUMMYNET, sizeof(*pkt), MB_DONTWAIT);
2464 if (mtag == NULL) {
2465 m_freem(m);
2466 return;
2467 }
2468 m_tag_prepend(m, mtag);
2469
2470 pkt = m_tag_data(mtag);
2471 bzero(pkt, sizeof(*pkt));
2472
2473 cmd = fwa->rule->cmd + fwa->rule->act_ofs;
2474 if (cmd->opcode == O_LOG)
2475 cmd += F_LEN(cmd);
2476 KASSERT(cmd->opcode == O_PIPE || cmd->opcode == O_QUEUE,
2477 ("Rule is not PIPE or QUEUE, opcode %d\n", cmd->opcode));
2478
2479 pkt->dn_m = m;
2480 pkt->dn_flags = (dir & DN_FLAGS_DIR_MASK);
2481 pkt->ifp = fwa->oif;
2482 pkt->pipe_nr = pipe_nr;
2483
2484 pkt->cpuid = mycpuid;
2485 pkt->msgport = curnetport;
2486
2487 id = &fwa->f_id;
2488 fid = &pkt->id;
2489 fid->fid_dst_ip = id->dst_ip;
2490 fid->fid_src_ip = id->src_ip;
2491 fid->fid_dst_port = id->dst_port;
2492 fid->fid_src_port = id->src_port;
2493 fid->fid_proto = id->proto;
2494 fid->fid_flags = id->flags;
2495
2496 ipfw_ref_rule(fwa->rule);
2497 pkt->dn_priv = fwa->rule;
2498 pkt->dn_unref_priv = ipfw_unref_rule;
2499
2500 if (cmd->opcode == O_PIPE)
2501 pkt->dn_flags |= DN_FLAGS_IS_PIPE;
2502
2503 m->m_pkthdr.fw_flags |= DUMMYNET_MBUF_TAGGED;
2504 }
2505
2506 /*
2507 * When a rule is added/deleted, clear the next_rule pointers in all rules.
2508 * These will be reconstructed on the fly as packets are matched.
2509 * Must be called at splimp().
2510 */
2511 static void
2512 ipfw_flush_rule_ptrs(struct ipfw_context *ctx)
2513 {
2514 struct ip_fw *rule;
2515
2516 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next)
2517 rule->next_rule = NULL;
2518 }
2519
2520 static __inline void
2521 ipfw_inc_static_count(struct ip_fw *rule)
2522 {
2523 /* Static rule's counts are updated only on CPU0 */
2524 KKASSERT(mycpuid == 0);
2525
2526 static_count++;
2527 static_ioc_len += IOC_RULESIZE(rule);
2528 }
2529
2530 static __inline void
2531 ipfw_dec_static_count(struct ip_fw *rule)
2532 {
2533 int l = IOC_RULESIZE(rule);
2534
2535 /* Static rule's counts are updated only on CPU0 */
2536 KKASSERT(mycpuid == 0);
2537
2538 KASSERT(static_count > 0, ("invalid static count %u\n", static_count));
2539 static_count--;
2540
2541 KASSERT(static_ioc_len >= l,
2542 ("invalid static len %u\n", static_ioc_len));
2543 static_ioc_len -= l;
2544 }
2545
2546 static void
2547 ipfw_link_sibling(struct netmsg_ipfw *fwmsg, struct ip_fw *rule)
2548 {
2549 if (fwmsg->sibling != NULL) {
2550 KKASSERT(mycpuid > 0 && fwmsg->sibling->cpuid == mycpuid - 1);
2551 fwmsg->sibling->sibling = rule;
2552 }
2553 fwmsg->sibling = rule;
2554 }
2555
2556 static struct ip_fw *
2557 ipfw_create_rule(const struct ipfw_ioc_rule *ioc_rule, struct ip_fw_stub *stub)
2558 {
2559 struct ip_fw *rule;
2560
2561 rule = kmalloc(RULESIZE(ioc_rule), M_IPFW, M_WAITOK | M_ZERO);
2562
2563 rule->act_ofs = ioc_rule->act_ofs;
2564 rule->cmd_len = ioc_rule->cmd_len;
2565 rule->rulenum = ioc_rule->rulenum;
2566 rule->set = ioc_rule->set;
2567 rule->usr_flags = ioc_rule->usr_flags;
2568
2569 bcopy(ioc_rule->cmd, rule->cmd, rule->cmd_len * 4 /* XXX */);
2570
2571 rule->refcnt = 1;
2572 rule->cpuid = mycpuid;
2573
2574 rule->stub = stub;
2575 if (stub != NULL)
2576 stub->rule[mycpuid] = rule;
2577
2578 return rule;
2579 }
2580
2581 static void
2582 ipfw_add_rule_dispatch(struct netmsg *nmsg)
2583 {
2584 struct netmsg_ipfw *fwmsg = (struct netmsg_ipfw *)nmsg;
2585 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2586 struct ip_fw *rule;
2587
2588 rule = ipfw_create_rule(fwmsg->ioc_rule, fwmsg->stub);
2589
2590 /*
2591 * Bump generation after ipfw_create_rule(),
2592 * since this function is blocking
2593 */
2594 ctx->ipfw_gen++;
2595
2596 /*
2597 * Insert rule into the pre-determined position
2598 */
2599 if (fwmsg->prev_rule != NULL) {
2600 struct ip_fw *prev, *next;
2601
2602 prev = fwmsg->prev_rule;
2603 KKASSERT(prev->cpuid == mycpuid);
2604
2605 next = fwmsg->next_rule;
2606 KKASSERT(next->cpuid == mycpuid);
2607
2608 rule->next = next;
2609 prev->next = rule;
2610
2611 /*
2612 * Move to the position on the next CPU
2613 * before the msg is forwarded.
2614 */
2615 fwmsg->prev_rule = prev->sibling;
2616 fwmsg->next_rule = next->sibling;
2617 } else {
2618 KKASSERT(fwmsg->next_rule == NULL);
2619 rule->next = ctx->ipfw_layer3_chain;
2620 ctx->ipfw_layer3_chain = rule;
2621 }
2622
2623 /* Link rule CPU sibling */
2624 ipfw_link_sibling(fwmsg, rule);
2625
2626 ipfw_flush_rule_ptrs(ctx);
2627
2628 if (mycpuid == 0) {
2629 /* Statistics only need to be updated once */
2630 ipfw_inc_static_count(rule);
2631
2632 /* Return the rule on CPU0 */
2633 nmsg->nm_lmsg.u.ms_resultp = rule;
2634 }
2635
2636 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
2637 }
2638
2639 static void
2640 ipfw_enable_state_dispatch(struct netmsg *nmsg)
2641 {
2642 struct lwkt_msg *lmsg = &nmsg->nm_lmsg;
2643 struct ip_fw *rule = lmsg->u.ms_resultp;
2644 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2645
2646 ctx->ipfw_gen++;
2647
2648 KKASSERT(rule->cpuid == mycpuid);
2649 KKASSERT(rule->stub != NULL && rule->stub->rule[mycpuid] == rule);
2650 KKASSERT(!(rule->rule_flags & IPFW_RULE_F_STATE));
2651 rule->rule_flags |= IPFW_RULE_F_STATE;
2652 lmsg->u.ms_resultp = rule->sibling;
2653
2654 ifnet_forwardmsg(lmsg, mycpuid + 1);
2655 }
2656
2657 /*
2658 * Add a new rule to the list. Copy the rule into a malloc'ed area,
2659 * then possibly create a rule number and add the rule to the list.
2660 * Update the rule_number in the input struct so the caller knows
2661 * it as well.
2662 */
2663 static void
2664 ipfw_add_rule(struct ipfw_ioc_rule *ioc_rule, uint32_t rule_flags)
2665 {
2666 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2667 struct netmsg_ipfw fwmsg;
2668 struct netmsg *nmsg;
2669 struct ip_fw *f, *prev, *rule;
2670 struct ip_fw_stub *stub;
2671
2672 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
2673
2674 /*
2675 * If rulenum is 0, find highest numbered rule before the
2676 * default rule, and add rule number incremental step.
2677 */
2678 if (ioc_rule->rulenum == 0) {
2679 int step = autoinc_step;
2680
2681 KKASSERT(step >= IPFW_AUTOINC_STEP_MIN &&
2682 step <= IPFW_AUTOINC_STEP_MAX);
2683
2684 /*
2685 * Locate the highest numbered rule before default
2686 */
2687 for (f = ctx->ipfw_layer3_chain; f; f = f->next) {
2688 if (f->rulenum == IPFW_DEFAULT_RULE)
2689 break;
2690 ioc_rule->rulenum = f->rulenum;
2691 }
2692 if (ioc_rule->rulenum < IPFW_DEFAULT_RULE - step)
2693 ioc_rule->rulenum += step;
2694 }
2695 KASSERT(ioc_rule->rulenum != IPFW_DEFAULT_RULE &&
2696 ioc_rule->rulenum != 0,
2697 ("invalid rule num %d\n", ioc_rule->rulenum));
2698
2699 /*
2700 * Now find the right place for the new rule in the sorted list.
2701 */
2702 for (prev = NULL, f = ctx->ipfw_layer3_chain; f;
2703 prev = f, f = f->next) {
2704 if (f->rulenum > ioc_rule->rulenum) {
2705 /* Found the location */
2706 break;
2707 }
2708 }
2709 KASSERT(f != NULL, ("no default rule?!\n"));
2710
2711 if (rule_flags & IPFW_RULE_F_STATE) {
2712 int size;
2713
2714 /*
2715 * If the new rule will create states, then allocate
2716 * a rule stub, which will be referenced by states
2717 * (dyn rules)
2718 */
2719 size = sizeof(*stub) + ((ncpus - 1) * sizeof(struct ip_fw *));
2720 stub = kmalloc(size, M_IPFW, M_WAITOK | M_ZERO);
2721 } else {
2722 stub = NULL;
2723 }
2724
2725 /*
2726 * Duplicate the rule onto each CPU.
2727 * The rule duplicated on CPU0 will be returned.
2728 */
2729 bzero(&fwmsg, sizeof(fwmsg));
2730 nmsg = &fwmsg.nmsg;
2731 netmsg_init(nmsg, &curthread->td_msgport, 0, ipfw_add_rule_dispatch);
2732 fwmsg.ioc_rule = ioc_rule;
2733 fwmsg.prev_rule = prev;
2734 fwmsg.next_rule = prev == NULL ? NULL : f;
2735 fwmsg.stub = stub;
2736
2737 ifnet_domsg(&nmsg->nm_lmsg, 0);
2738 KKASSERT(fwmsg.prev_rule == NULL && fwmsg.next_rule == NULL);
2739
2740 rule = nmsg->nm_lmsg.u.ms_resultp;
2741 KKASSERT(rule != NULL && rule->cpuid == mycpuid);
2742
2743 if (rule_flags & IPFW_RULE_F_STATE) {
2744 /*
2745 * Turn on state flag, _after_ everything on all
2746 * CPUs have been setup.
2747 */
2748 bzero(nmsg, sizeof(*nmsg));
2749 netmsg_init(nmsg, &curthread->td_msgport, 0,
2750 ipfw_enable_state_dispatch);
2751 nmsg->nm_lmsg.u.ms_resultp = rule;
2752
2753 ifnet_domsg(&nmsg->nm_lmsg, 0);
2754 KKASSERT(nmsg->nm_lmsg.u.ms_resultp == NULL);
2755 }
2756
2757 DPRINTF("++ installed rule %d, static count now %d\n",
2758 rule->rulenum, static_count);
2759 }
2760
2761 /**
2762 * Free storage associated with a static rule (including derived
2763 * dynamic rules).
2764 * The caller is in charge of clearing rule pointers to avoid
2765 * dangling pointers.
2766 * @return a pointer to the next entry.
2767 * Arguments are not checked, so they better be correct.
2768 * Must be called at splimp().
2769 */
2770 static struct ip_fw *
2771 ipfw_delete_rule(struct ipfw_context *ctx,
2772 struct ip_fw *prev, struct ip_fw *rule)
2773 {
2774 struct ip_fw *n;
2775 struct ip_fw_stub *stub;
2776
2777 ctx->ipfw_gen++;
2778
2779 /* STATE flag should have been cleared before we reach here */
2780 KKASSERT((rule->rule_flags & IPFW_RULE_F_STATE) == 0);
2781
2782 stub = rule->stub;
2783 n = rule->next;
2784 if (prev == NULL)
2785 ctx->ipfw_layer3_chain = n;
2786 else
2787 prev->next = n;
2788
2789 /* Mark the rule as invalid */
2790 rule->rule_flags |= IPFW_RULE_F_INVALID;
2791 rule->next_rule = NULL;
2792 rule->sibling = NULL;
2793 rule->stub = NULL;
2794 #ifdef foo
2795 /* Don't reset cpuid here; keep various assertion working */
2796 rule->cpuid = -1;
2797 #endif
2798
2799 /* Statistics only need to be updated once */
2800 if (mycpuid == 0)
2801 ipfw_dec_static_count(rule);
2802
2803 /* Free 'stub' on the last CPU */
2804 if (stub != NULL && mycpuid == ncpus - 1)
2805 kfree(stub, M_IPFW);
2806
2807 /* Try to free this rule */
2808 ipfw_free_rule(rule);
2809
2810 /* Return the next rule */
2811 return n;
2812 }
2813
2814 static void
2815 ipfw_flush_dispatch(struct netmsg *nmsg)
2816 {
2817 struct lwkt_msg *lmsg = &nmsg->nm_lmsg;
2818 int kill_default = lmsg->u.ms_result;
2819 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2820 struct ip_fw *rule;
2821
2822 ipfw_flush_rule_ptrs(ctx); /* more efficient to do outside the loop */
2823
2824 while ((rule = ctx->ipfw_layer3_chain) != NULL &&
2825 (kill_default || rule->rulenum != IPFW_DEFAULT_RULE))
2826 ipfw_delete_rule(ctx, NULL, rule);
2827
2828 ifnet_forwardmsg(lmsg, mycpuid + 1);
2829 }
2830
2831 static void
2832 ipfw_disable_rule_state_dispatch(struct netmsg *nmsg)
2833 {
2834 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
2835 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2836 struct ip_fw *rule;
2837
2838 ctx->ipfw_gen++;
2839
2840 rule = dmsg->start_rule;
2841 if (rule != NULL) {
2842 KKASSERT(rule->cpuid == mycpuid);
2843
2844 /*
2845 * Move to the position on the next CPU
2846 * before the msg is forwarded.
2847 */
2848 dmsg->start_rule = rule->sibling;
2849 } else {
2850 KKASSERT(dmsg->rulenum == 0);
2851 rule = ctx->ipfw_layer3_chain;
2852 }
2853
2854 while (rule != NULL) {
2855 if (dmsg->rulenum && rule->rulenum != dmsg->rulenum)
2856 break;
2857 rule->rule_flags &= ~IPFW_RULE_F_STATE;
2858 rule = rule->next;
2859 }
2860
2861 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
2862 }
2863
2864 /*
2865 * Deletes all rules from a chain (including the default rule
2866 * if the second argument is set).
2867 * Must be called at splimp().
2868 */
2869 static void
2870 ipfw_flush(int kill_default)
2871 {
2872 struct netmsg_del dmsg;
2873 struct netmsg nmsg;
2874 struct lwkt_msg *lmsg;
2875 struct ip_fw *rule;
2876 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2877
2878 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
2879
2880 /*
2881 * If 'kill_default' then caller has done the necessary
2882 * msgport syncing; unnecessary to do it again.
2883 */
2884 if (!kill_default) {
2885 /*
2886 * Let ipfw_chk() know the rules are going to
2887 * be flushed, so it could jump directly to
2888 * the default rule.
2889 */
2890 ipfw_flushing = 1;
2891 netmsg_service_sync();
2892 }
2893
2894 /*
2895 * Clear STATE flag on rules, so no more states (dyn rules)
2896 * will be created.
2897 */
2898 bzero(&dmsg, sizeof(dmsg));
2899 netmsg_init(&dmsg.nmsg, &curthread->td_msgport, 0,
2900 ipfw_disable_rule_state_dispatch);
2901 ifnet_domsg(&dmsg.nmsg.nm_lmsg, 0);
2902
2903 /*
2904 * This actually nukes all states (dyn rules)
2905 */
2906 lockmgr(&dyn_lock, LK_EXCLUSIVE);
2907 for (rule = ctx->ipfw_layer3_chain; rule != NULL; rule = rule->next) {
2908 /*
2909 * Can't check IPFW_RULE_F_STATE here,
2910 * since it has been cleared previously.
2911 * Check 'stub' instead.
2912 */
2913 if (rule->stub != NULL) {
2914 /* Force removal */
2915 remove_dyn_rule_locked(rule, NULL);
2916 }
2917 }
2918 lockmgr(&dyn_lock, LK_RELEASE);
2919
2920 /*
2921 * Press the 'flush' button
2922 */
2923 bzero(&nmsg, sizeof(nmsg));
2924 netmsg_init(&nmsg, &curthread->td_msgport, 0, ipfw_flush_dispatch);
2925 lmsg = &nmsg.nm_lmsg;
2926 lmsg->u.ms_result = kill_default;
2927 ifnet_domsg(lmsg, 0);
2928
2929 KASSERT(dyn_count == 0, ("%u dyn rule remains\n", dyn_count));
2930
2931 if (kill_default) {
2932 if (ipfw_dyn_v != NULL) {
2933 /*
2934 * Free dynamic rules(state) hash table
2935 */
2936 kfree(ipfw_dyn_v, M_IPFW);
2937 ipfw_dyn_v = NULL;
2938 }
2939
2940 KASSERT(static_count == 0,
2941 ("%u static rules remains\n", static_count));
2942 KASSERT(static_ioc_len == 0,
2943 ("%u bytes of static rules remains\n", static_ioc_len));
2944 } else {
2945 KASSERT(static_count == 1,
2946 ("%u static rules remains\n", static_count));
2947 KASSERT(static_ioc_len == IOC_RULESIZE(ctx->ipfw_default_rule),
2948 ("%u bytes of static rules remains, should be %u\n",
2949 static_ioc_len, IOC_RULESIZE(ctx->ipfw_default_rule)));
2950 }
2951
2952 /* Flush is done */
2953 ipfw_flushing = 0;
2954 }
2955
2956 static void
2957 ipfw_alt_delete_rule_dispatch(struct netmsg *nmsg)
2958 {
2959 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
2960 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2961 struct ip_fw *rule, *prev;
2962
2963 rule = dmsg->start_rule;
2964 KKASSERT(rule->cpuid == mycpuid);
2965 dmsg->start_rule = rule->sibling;
2966
2967 prev = dmsg->prev_rule;
2968 if (prev != NULL) {
2969 KKASSERT(prev->cpuid == mycpuid);
2970
2971 /*
2972 * Move to the position on the next CPU
2973 * before the msg is forwarded.
2974 */
2975 dmsg->prev_rule = prev->sibling;
2976 }
2977
2978 /*
2979 * flush pointers outside the loop, then delete all matching
2980 * rules. 'prev' remains the same throughout the cycle.
2981 */
2982 ipfw_flush_rule_ptrs(ctx);
2983 while (rule && rule->rulenum == dmsg->rulenum)
2984 rule = ipfw_delete_rule(ctx, prev, rule);
2985
2986 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
2987 }
2988
2989 static int
2990 ipfw_alt_delete_rule(uint16_t rulenum)
2991 {
2992 struct ip_fw *prev, *rule, *f;
2993 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
2994 struct netmsg_del dmsg;
2995 struct netmsg *nmsg;
2996 int state;
2997
2998 /*
2999 * Locate first rule to delete
3000 */
3001 for (prev = NULL, rule = ctx->ipfw_layer3_chain;
3002 rule && rule->rulenum < rulenum;
3003 prev = rule, rule = rule->next)
3004 ; /* EMPTY */
3005 if (rule->rulenum != rulenum)
3006 return EINVAL;
3007
3008 /*
3009 * Check whether any rules with the given number will
3010 * create states.
3011 */
3012 state = 0;
3013 for (f = rule; f && f->rulenum == rulenum; f = f->next) {
3014 if (f->rule_flags & IPFW_RULE_F_STATE) {
3015 state = 1;
3016 break;
3017 }
3018 }
3019
3020 if (state) {
3021 /*
3022 * Clear the STATE flag, so no more states will be
3023 * created based the rules numbered 'rulenum'.
3024 */
3025 bzero(&dmsg, sizeof(dmsg));
3026 nmsg = &dmsg.nmsg;
3027 netmsg_init(nmsg, &curthread->td_msgport, 0,
3028 ipfw_disable_rule_state_dispatch);
3029 dmsg.start_rule = rule;
3030 dmsg.rulenum = rulenum;
3031
3032 ifnet_domsg(&nmsg->nm_lmsg, 0);
3033 KKASSERT(dmsg.start_rule == NULL);
3034
3035 /*
3036 * Nuke all related states
3037 */
3038 lockmgr(&dyn_lock, LK_EXCLUSIVE);
3039 for (f = rule; f && f->rulenum == rulenum; f = f->next) {
3040 /*
3041 * Can't check IPFW_RULE_F_STATE here,
3042 * since it has been cleared previously.
3043 * Check 'stub' instead.
3044 */
3045 if (f->stub != NULL) {
3046 /* Force removal */
3047 remove_dyn_rule_locked(f, NULL);
3048 }
3049 }
3050 lockmgr(&dyn_lock, LK_RELEASE);
3051 }
3052
3053 /*
3054 * Get rid of the rule duplications on all CPUs
3055 */
3056 bzero(&dmsg, sizeof(dmsg));
3057 nmsg = &dmsg.nmsg;
3058 netmsg_init(nmsg, &curthread->td_msgport, 0,
3059 ipfw_alt_delete_rule_dispatch);
3060 dmsg.prev_rule = prev;
3061 dmsg.start_rule = rule;
3062 dmsg.rulenum = rulenum;
3063
3064 ifnet_domsg(&nmsg->nm_lmsg, 0);
3065 KKASSERT(dmsg.prev_rule == NULL && dmsg.start_rule == NULL);
3066 return 0;
3067 }
3068
3069 static void
3070 ipfw_alt_delete_ruleset_dispatch(struct netmsg *nmsg)
3071 {
3072 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
3073 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3074 struct ip_fw *prev, *rule;
3075 #ifdef INVARIANTS
3076 int del = 0;
3077 #endif
3078
3079 ipfw_flush_rule_ptrs(ctx);
3080
3081 prev = NULL;
3082 rule = ctx->ipfw_layer3_chain;
3083 while (rule != NULL) {
3084 if (rule->set == dmsg->from_set) {
3085 rule = ipfw_delete_rule(ctx, prev, rule);
3086 #ifdef INVARIANTS
3087 del = 1;
3088 #endif
3089 } else {
3090 prev = rule;
3091 rule = rule->next;
3092 }
3093 }
3094 KASSERT(del, ("no match set?!\n"));
3095
3096 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
3097 }
3098
3099 static void
3100 ipfw_disable_ruleset_state_dispatch(struct netmsg *nmsg)
3101 {
3102 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
3103 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3104 struct ip_fw *rule;
3105 #ifdef INVARIANTS
3106 int cleared = 0;
3107 #endif
3108
3109 ctx->ipfw_gen++;
3110
3111 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) {
3112 if (rule->set == dmsg->from_set) {
3113 #ifdef INVARIANTS
3114 cleared = 1;
3115 #endif
3116 rule->rule_flags &= ~IPFW_RULE_F_STATE;
3117 }
3118 }
3119 KASSERT(cleared, ("no match set?!\n"));
3120
3121 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
3122 }
3123
3124 static int
3125 ipfw_alt_delete_ruleset(uint8_t set)
3126 {
3127 struct netmsg_del dmsg;
3128 struct netmsg *nmsg;
3129 int state, del;
3130 struct ip_fw *rule;
3131 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3132
3133 /*
3134 * Check whether the 'set' exists. If it exists,
3135 * then check whether any rules within the set will
3136 * try to create states.
3137 */
3138 state = 0;
3139 del = 0;
3140 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) {
3141 if (rule->set == set) {
3142 del = 1;
3143 if (rule->rule_flags & IPFW_RULE_F_STATE) {
3144 state = 1;
3145 break;
3146 }
3147 }
3148 }
3149 if (!del)
3150 return 0; /* XXX EINVAL? */
3151
3152 if (state) {
3153 /*
3154 * Clear the STATE flag, so no more states will be
3155 * created based the rules in this set.
3156 */
3157 bzero(&dmsg, sizeof(dmsg));
3158 nmsg = &dmsg.nmsg;
3159 netmsg_init(nmsg, &curthread->td_msgport, 0,
3160 ipfw_disable_ruleset_state_dispatch);
3161 dmsg.from_set = set;
3162
3163 ifnet_domsg(&nmsg->nm_lmsg, 0);
3164
3165 /*
3166 * Nuke all related states
3167 */
3168 lockmgr(&dyn_lock, LK_EXCLUSIVE);
3169 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) {
3170 if (rule->set != set)
3171 continue;
3172
3173 /*
3174 * Can't check IPFW_RULE_F_STATE here,
3175 * since it has been cleared previously.
3176 * Check 'stub' instead.
3177 */
3178 if (rule->stub != NULL) {
3179 /* Force removal */
3180 remove_dyn_rule_locked(rule, NULL);
3181 }
3182 }
3183 lockmgr(&dyn_lock, LK_RELEASE);
3184 }
3185
3186 /*
3187 * Delete this set
3188 */
3189 bzero(&dmsg, sizeof(dmsg));
3190 nmsg = &dmsg.nmsg;
3191 netmsg_init(nmsg, &curthread->td_msgport, 0,
3192 ipfw_alt_delete_ruleset_dispatch);
3193 dmsg.from_set = set;
3194
3195 ifnet_domsg(&nmsg->nm_lmsg, 0);
3196 return 0;
3197 }
3198
3199 static void
3200 ipfw_alt_move_rule_dispatch(struct netmsg *nmsg)
3201 {
3202 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
3203 struct ip_fw *rule;
3204
3205 rule = dmsg->start_rule;
3206 KKASSERT(rule->cpuid == mycpuid);
3207
3208 /*
3209 * Move to the position on the next CPU
3210 * before the msg is forwarded.
3211 */
3212 dmsg->start_rule = rule->sibling;
3213
3214 while (rule && rule->rulenum <= dmsg->rulenum) {
3215 if (rule->rulenum == dmsg->rulenum)
3216 rule->set = dmsg->to_set;
3217 rule = rule->next;
3218 }
3219 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
3220 }
3221
3222 static int
3223 ipfw_alt_move_rule(uint16_t rulenum, uint8_t set)
3224 {
3225 struct netmsg_del dmsg;
3226 struct netmsg *nmsg;
3227 struct ip_fw *rule;
3228 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3229
3230 /*
3231 * Locate first rule to move
3232 */
3233 for (rule = ctx->ipfw_layer3_chain; rule && rule->rulenum <= rulenum;
3234 rule = rule->next) {
3235 if (rule->rulenum == rulenum && rule->set != set)
3236 break;
3237 }
3238 if (rule == NULL || rule->rulenum > rulenum)
3239 return 0; /* XXX error? */
3240
3241 bzero(&dmsg, sizeof(dmsg));
3242 nmsg = &dmsg.nmsg;
3243 netmsg_init(nmsg, &curthread->td_msgport, 0,
3244 ipfw_alt_move_rule_dispatch);
3245 dmsg.start_rule = rule;
3246 dmsg.rulenum = rulenum;
3247 dmsg.to_set = set;
3248
3249 ifnet_domsg(&nmsg->nm_lmsg, 0);
3250 KKASSERT(dmsg.start_rule == NULL);
3251 return 0;
3252 }
3253
3254 static void
3255 ipfw_alt_move_ruleset_dispatch(struct netmsg *nmsg)
3256 {
3257 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
3258 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3259 struct ip_fw *rule;
3260
3261 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) {
3262 if (rule->set == dmsg->from_set)
3263 rule->set = dmsg->to_set;
3264 }
3265 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
3266 }
3267
3268 static int
3269 ipfw_alt_move_ruleset(uint8_t from_set, uint8_t to_set)
3270 {
3271 struct netmsg_del dmsg;
3272 struct netmsg *nmsg;
3273
3274 bzero(&dmsg, sizeof(dmsg));
3275 nmsg = &dmsg.nmsg;
3276 netmsg_init(nmsg, &curthread->td_msgport, 0,
3277 ipfw_alt_move_ruleset_dispatch);
3278 dmsg.from_set = from_set;
3279 dmsg.to_set = to_set;
3280
3281 ifnet_domsg(&nmsg->nm_lmsg, 0);
3282 return 0;
3283 }
3284
3285 static void
3286 ipfw_alt_swap_ruleset_dispatch(struct netmsg *nmsg)
3287 {
3288 struct netmsg_del *dmsg = (struct netmsg_del *)nmsg;
3289 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3290 struct ip_fw *rule;
3291
3292 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) {
3293 if (rule->set == dmsg->from_set)
3294 rule->set = dmsg->to_set;
3295 else if (rule->set == dmsg->to_set)
3296 rule->set = dmsg->from_set;
3297 }
3298 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
3299 }
3300
3301 static int
3302 ipfw_alt_swap_ruleset(uint8_t set1, uint8_t set2)
3303 {
3304 struct netmsg_del dmsg;
3305 struct netmsg *nmsg;
3306
3307 bzero(&dmsg, sizeof(dmsg));
3308 nmsg = &dmsg.nmsg;
3309 netmsg_init(nmsg, &curthread->td_msgport, 0,
3310 ipfw_alt_swap_ruleset_dispatch);
3311 dmsg.from_set = set1;
3312 dmsg.to_set = set2;
3313
3314 ifnet_domsg(&nmsg->nm_lmsg, 0);
3315 return 0;
3316 }
3317
3318 /**
3319 * Remove all rules with given number, and also do set manipulation.
3320 *
3321 * The argument is an uint32_t. The low 16 bit are the rule or set number,
3322 * the next 8 bits are the new set, the top 8 bits are the command:
3323 *
3324 * 0 delete rules with given number
3325 * 1 delete rules with given set number
3326 * 2 move rules with given number to new set
3327 * 3 move rules with given set number to new set
3328 * 4 swap sets with given numbers
3329 */
3330 static int
3331 ipfw_ctl_alter(uint32_t arg)
3332 {
3333 uint16_t rulenum;
3334 uint8_t cmd, new_set;
3335 int error = 0;
3336
3337 rulenum = arg & 0xffff;
3338 cmd = (arg >> 24) & 0xff;
3339 new_set = (arg >> 16) & 0xff;
3340
3341 if (cmd > 4)
3342 return EINVAL;
3343 if (new_set >= IPFW_DEFAULT_SET)
3344 return EINVAL;
3345 if (cmd == 0 || cmd == 2) {
3346 if (rulenum == IPFW_DEFAULT_RULE)
3347 return EINVAL;
3348 } else {
3349 if (rulenum >= IPFW_DEFAULT_SET)
3350 return EINVAL;
3351 }
3352
3353 switch (cmd) {
3354 case 0: /* delete rules with given number */
3355 error = ipfw_alt_delete_rule(rulenum);
3356 break;
3357
3358 case 1: /* delete all rules with given set number */
3359 error = ipfw_alt_delete_ruleset(rulenum);
3360 break;
3361
3362 case 2: /* move rules with given number to new set */
3363 error = ipfw_alt_move_rule(rulenum, new_set);
3364 break;
3365
3366 case 3: /* move rules with given set number to new set */
3367 error = ipfw_alt_move_ruleset(rulenum, new_set);
3368 break;
3369
3370 case 4: /* swap two sets */
3371 error = ipfw_alt_swap_ruleset(rulenum, new_set);
3372 break;
3373 }
3374 return error;
3375 }
3376
3377 /*
3378 * Clear counters for a specific rule.
3379 */
3380 static void
3381 clear_counters(struct ip_fw *rule, int log_only)
3382 {
3383 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
3384
3385 if (log_only == 0) {
3386 rule->bcnt = rule->pcnt = 0;
3387 rule->timestamp = 0;
3388 }
3389 if (l->o.opcode == O_LOG)
3390 l->log_left = l->max_log;
3391 }
3392
3393 static void
3394 ipfw_zero_entry_dispatch(struct netmsg *nmsg)
3395 {
3396 struct netmsg_zent *zmsg = (struct netmsg_zent *)nmsg;
3397 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3398 struct ip_fw *rule;
3399
3400 if (zmsg->rulenum == 0) {
3401 KKASSERT(zmsg->start_rule == NULL);
3402
3403 ctx->ipfw_norule_counter = 0;
3404 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next)
3405 clear_counters(rule, zmsg->log_only);
3406 } else {
3407 struct ip_fw *start = zmsg->start_rule;
3408
3409 KKASSERT(start->cpuid == mycpuid);
3410 KKASSERT(start->rulenum == zmsg->rulenum);
3411
3412 /*
3413 * We can have multiple rules with the same number, so we
3414 * need to clear them all.
3415 */
3416 for (rule = start; rule && rule->rulenum == zmsg->rulenum;
3417 rule = rule->next)
3418 clear_counters(rule, zmsg->log_only);
3419
3420 /*
3421 * Move to the position on the next CPU
3422 * before the msg is forwarded.
3423 */
3424 zmsg->start_rule = start->sibling;
3425 }
3426 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
3427 }
3428
3429 /**
3430 * Reset some or all counters on firewall rules.
3431 * @arg frwl is null to clear all entries, or contains a specific
3432 * rule number.
3433 * @arg log_only is 1 if we only want to reset logs, zero otherwise.
3434 */
3435 static int
3436 ipfw_ctl_zero_entry(int rulenum, int log_only)
3437 {
3438 struct netmsg_zent zmsg;
3439 struct netmsg *nmsg;
3440 const char *msg;
3441 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3442
3443 bzero(&zmsg, sizeof(zmsg));
3444 nmsg = &zmsg.nmsg;
3445 netmsg_init(nmsg, &curthread->td_msgport, 0, ipfw_zero_entry_dispatch);
3446 zmsg.log_only = log_only;
3447
3448 if (rulenum == 0) {
3449 msg = log_only ? "ipfw: All logging counts reset.\n"
3450 : "ipfw: Accounting cleared.\n";
3451 } else {
3452 struct ip_fw *rule;
3453
3454 /*
3455 * Locate the first rule with 'rulenum'
3456 */
3457 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next) {
3458 if (rule->rulenum == rulenum)
3459 break;
3460 }
3461 if (rule == NULL) /* we did not find any matching rules */
3462 return (EINVAL);
3463 zmsg.start_rule = rule;
3464 zmsg.rulenum = rulenum;
3465
3466 msg = log_only ? "ipfw: Entry %d logging count reset.\n"
3467 : "ipfw: Entry %d cleared.\n";
3468 }
3469 ifnet_domsg(&nmsg->nm_lmsg, 0);
3470 KKASSERT(zmsg.start_rule == NULL);
3471
3472 if (fw_verbose)
3473 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
3474 return (0);
3475 }
3476
3477 /*
3478 * Check validity of the structure before insert.
3479 * Fortunately rules are simple, so this mostly need to check rule sizes.
3480 */
3481 static int
3482 ipfw_check_ioc_rule(struct ipfw_ioc_rule *rule, int size, uint32_t *rule_flags)
3483 {
3484 int l, cmdlen = 0;
3485 int have_action = 0;
3486 ipfw_insn *cmd;
3487
3488 *rule_flags = 0;
3489
3490 /* Check for valid size */
3491 if (size < sizeof(*rule)) {
3492 kprintf("ipfw: rule too short\n");
3493 return EINVAL;
3494 }
3495 l = IOC_RULESIZE(rule);
3496 if (l != size) {
3497 kprintf("ipfw: size mismatch (have %d want %d)\n", size, l);
3498 return EINVAL;
3499 }
3500
3501 /* Check rule number */
3502 if (rule->rulenum == IPFW_DEFAULT_RULE) {
3503 kprintf("ipfw: invalid rule number\n");
3504 return EINVAL;
3505 }
3506
3507 /*
3508 * Now go for the individual checks. Very simple ones, basically only
3509 * instruction sizes.
3510 */
3511 for (l = rule->cmd_len, cmd = rule->cmd; l > 0;
3512 l -= cmdlen, cmd += cmdlen) {
3513 cmdlen = F_LEN(cmd);
3514 if (cmdlen > l) {
3515 kprintf("ipfw: opcode %d size truncated\n",
3516 cmd->opcode);
3517 return EINVAL;
3518 }
3519
3520 DPRINTF("ipfw: opcode %d\n", cmd->opcode);
3521
3522 if (cmd->opcode == O_KEEP_STATE || cmd->opcode == O_LIMIT) {
3523 /* This rule will create states */
3524 *rule_flags |= IPFW_RULE_F_STATE;
3525 }
3526
3527 switch (cmd->opcode) {
3528 case O_NOP:
3529 case O_PROBE_STATE:
3530 case O_KEEP_STATE:
3531 case O_PROTO:
3532 case O_IP_SRC_ME:
3533 case O_IP_DST_ME:
3534 case O_LAYER2:
3535 case O_IN:
3536 case O_FRAG:
3537 case O_IPOPT:
3538 case O_IPLEN:
3539 case O_IPID:
3540 case O_IPTOS:
3541 case O_IPPRECEDENCE:
3542 case O_IPTTL:
3543 case O_IPVER:
3544 case O_TCPWIN:
3545 case O_TCPFLAGS:
3546 case O_TCPOPTS:
3547 case O_ESTAB:
3548 if (cmdlen != F_INSN_SIZE(ipfw_insn))
3549 goto bad_size;
3550 break;
3551
3552 case O_UID:
3553 case O_GID:
3554 case O_IP_SRC:
3555 case O_IP_DST:
3556 case O_TCPSEQ:
3557 case O_TCPACK:
3558 case O_PROB:
3559 case O_ICMPTYPE:
3560 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
3561 goto bad_size;
3562 break;
3563
3564 case O_LIMIT:
3565 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
3566 goto bad_size;
3567 break;
3568
3569 case O_LOG:
3570 if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
3571 goto bad_size;
3572
3573 ((ipfw_insn_log *)cmd)->log_left =
3574 ((ipfw_insn_log *)cmd)->max_log;
3575
3576 break;
3577
3578 case O_IP_SRC_MASK:
3579 case O_IP_DST_MASK:
3580 if (cmdlen != F_INSN_SIZE(ipfw_insn_ip))
3581 goto bad_size;
3582 if (((ipfw_insn_ip *)cmd)->mask.s_addr == 0) {
3583 kprintf("ipfw: opcode %d, useless rule\n",
3584 cmd->opcode);
3585 return EINVAL;
3586 }
3587 break;
3588
3589 case O_IP_SRC_SET:
3590 case O_IP_DST_SET:
3591 if (cmd->arg1 == 0 || cmd->arg1 > 256) {
3592 kprintf("ipfw: invalid set size %d\n",
3593 cmd->arg1);
3594 return EINVAL;
3595 }
3596 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
3597 (cmd->arg1+31)/32 )
3598 goto bad_size;
3599 break;
3600
3601 case O_MACADDR2:
3602 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
3603 goto bad_size;
3604 break;
3605
3606 case O_MAC_TYPE:
3607 case O_IP_SRCPORT:
3608 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
3609 if (cmdlen < 2 || cmdlen > 31)
3610 goto bad_size;
3611 break;
3612
3613 case O_RECV:
3614 case O_XMIT:
3615 case O_VIA:
3616 if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
3617 goto bad_size;
3618 break;
3619
3620 case O_PIPE:
3621 case O_QUEUE:
3622 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
3623 goto bad_size;
3624 goto check_action;
3625
3626 case O_FORWARD_IP:
3627 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) {
3628 goto bad_size;
3629 } else {
3630 in_addr_t fwd_addr;
3631
3632 fwd_addr = ((ipfw_insn_sa *)cmd)->
3633 sa.sin_addr.s_addr;
3634 if (IN_MULTICAST(ntohl(fwd_addr))) {
3635 kprintf("ipfw: try forwarding to "
3636 "multicast address\n");
3637 return EINVAL;
3638 }
3639 }
3640 goto check_action;
3641
3642 case O_FORWARD_MAC: /* XXX not implemented yet */
3643 case O_CHECK_STATE:
3644 case O_COUNT:
3645 case O_ACCEPT:
3646 case O_DENY:
3647 case O_REJECT:
3648 case O_SKIPTO:
3649 case O_DIVERT:
3650 case O_TEE:
3651 if (cmdlen != F_INSN_SIZE(ipfw_insn))
3652 goto bad_size;
3653 check_action:
3654 if (have_action) {
3655 kprintf("ipfw: opcode %d, multiple actions"
3656 " not allowed\n",
3657 cmd->opcode);
3658 return EINVAL;
3659 }
3660 have_action = 1;
3661 if (l != cmdlen) {
3662 kprintf("ipfw: opcode %d, action must be"
3663 " last opcode\n",
3664 cmd->opcode);
3665 return EINVAL;
3666 }
3667 break;
3668 default:
3669 kprintf("ipfw: opcode %d, unknown opcode\n",
3670 cmd->opcode);
3671 return EINVAL;
3672 }
3673 }
3674 if (have_action == 0) {
3675 kprintf("ipfw: missing action\n");
3676 return EINVAL;
3677 }
3678 return 0;
3679
3680 bad_size:
3681 kprintf("ipfw: opcode %d size %d wrong\n",
3682 cmd->opcode, cmdlen);
3683 return EINVAL;
3684 }
3685
3686 static int
3687 ipfw_ctl_add_rule(struct sockopt *sopt)
3688 {
3689 struct ipfw_ioc_rule *ioc_rule;
3690 size_t size;
3691 uint32_t rule_flags;
3692 int error;
3693
3694 size = sopt->sopt_valsize;
3695 if (size > (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX) ||
3696 size < sizeof(*ioc_rule)) {
3697 return EINVAL;
3698 }
3699 if (size != (sizeof(uint32_t) * IPFW_RULE_SIZE_MAX)) {
3700 sopt->sopt_val = krealloc(sopt->sopt_val, sizeof(uint32_t) *
3701 IPFW_RULE_SIZE_MAX, M_TEMP, M_WAITOK);
3702 }
3703 ioc_rule = sopt->sopt_val;
3704
3705 error = ipfw_check_ioc_rule(ioc_rule, size, &rule_flags);
3706 if (error)
3707 return error;
3708
3709 ipfw_add_rule(ioc_rule, rule_flags);
3710
3711 if (sopt->sopt_dir == SOPT_GET)
3712 sopt->sopt_valsize = IOC_RULESIZE(ioc_rule);
3713 return 0;
3714 }
3715
3716 static void *
3717 ipfw_copy_rule(const struct ip_fw *rule, struct ipfw_ioc_rule *ioc_rule)
3718 {
3719 const struct ip_fw *sibling;
3720 #ifdef INVARIANTS
3721 int i;
3722 #endif
3723
3724 KKASSERT(rule->cpuid == IPFW_CFGCPUID);
3725
3726 ioc_rule->act_ofs = rule->act_ofs;
3727 ioc_rule->cmd_len = rule->cmd_len;
3728 ioc_rule->rulenum = rule->rulenum;
3729 ioc_rule->set = rule->set;
3730 ioc_rule->usr_flags = rule->usr_flags;
3731
3732 ioc_rule->set_disable = ipfw_ctx[mycpuid]->ipfw_set_disable;
3733 ioc_rule->static_count = static_count;
3734 ioc_rule->static_len = static_ioc_len;
3735
3736 /*
3737 * Visit (read-only) all of the rule's duplications to get
3738 * the necessary statistics
3739 */
3740 #ifdef INVARIANTS
3741 i = 0;
3742 #endif
3743 ioc_rule->pcnt = 0;
3744 ioc_rule->bcnt = 0;
3745 ioc_rule->timestamp = 0;
3746 for (sibling = rule; sibling != NULL; sibling = sibling->sibling) {
3747 ioc_rule->pcnt += sibling->pcnt;
3748 ioc_rule->bcnt += sibling->bcnt;
3749 if (sibling->timestamp > ioc_rule->timestamp)
3750 ioc_rule->timestamp = sibling->timestamp;
3751 #ifdef INVARIANTS
3752 ++i;
3753 #endif
3754 }
3755 KASSERT(i == ncpus, ("static rule is not duplicated on every cpu\n"));
3756
3757 bcopy(rule->cmd, ioc_rule->cmd, ioc_rule->cmd_len * 4 /* XXX */);
3758
3759 return ((uint8_t *)ioc_rule + IOC_RULESIZE(ioc_rule));
3760 }
3761
3762 static void
3763 ipfw_copy_state(const ipfw_dyn_rule *dyn_rule,
3764 struct ipfw_ioc_state *ioc_state)
3765 {
3766 const struct ipfw_flow_id *id;
3767 struct ipfw_ioc_flowid *ioc_id;
3768
3769 ioc_state->expire = TIME_LEQ(dyn_rule->expire, time_second) ?
3770 0 : dyn_rule->expire - time_second;
3771 ioc_state->pcnt = dyn_rule->pcnt;
3772 ioc_state->bcnt = dyn_rule->bcnt;
3773
3774 ioc_state->dyn_type = dyn_rule->dyn_type;
3775 ioc_state->count = dyn_rule->count;
3776
3777 ioc_state->rulenum = dyn_rule->stub->rule[mycpuid]->rulenum;
3778
3779 id = &dyn_rule->id;
3780 ioc_id = &ioc_state->id;
3781
3782 ioc_id->type = ETHERTYPE_IP;
3783 ioc_id->u.ip.dst_ip = id->dst_ip;
3784 ioc_id->u.ip.src_ip = id->src_ip;
3785 ioc_id->u.ip.dst_port = id->dst_port;
3786 ioc_id->u.ip.src_port = id->src_port;
3787 ioc_id->u.ip.proto = id->proto;
3788 }
3789
3790 static int
3791 ipfw_ctl_get_rules(struct sockopt *sopt)
3792 {
3793 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3794 struct ip_fw *rule;
3795 void *bp;
3796 size_t size;
3797 uint32_t dcount = 0;
3798
3799 /*
3800 * pass up a copy of the current rules. Static rules
3801 * come first (the last of which has number IPFW_DEFAULT_RULE),
3802 * followed by a possibly empty list of dynamic rule.
3803 */
3804
3805 size = static_ioc_len; /* size of static rules */
3806 if (ipfw_dyn_v) { /* add size of dyn.rules */
3807 dcount = dyn_count;
3808 size += dcount * sizeof(struct ipfw_ioc_state);
3809 }
3810
3811 if (sopt->sopt_valsize < size) {
3812 /* short length, no need to return incomplete rules */
3813 /* XXX: if superuser, no need to zero buffer */
3814 bzero(sopt->sopt_val, sopt->sopt_valsize);
3815 return 0;
3816 }
3817 bp = sopt->sopt_val;
3818
3819 for (rule = ctx->ipfw_layer3_chain; rule; rule = rule->next)
3820 bp = ipfw_copy_rule(rule, bp);
3821
3822 if (ipfw_dyn_v && dcount != 0) {
3823 struct ipfw_ioc_state *ioc_state = bp;
3824 uint32_t dcount2 = 0;
3825 #ifdef INVARIANTS
3826 size_t old_size = size;
3827 #endif
3828 int i;
3829
3830 lockmgr(&dyn_lock, LK_SHARED);
3831
3832 /* Check 'ipfw_dyn_v' again with lock held */
3833 if (ipfw_dyn_v == NULL)
3834 goto skip;
3835
3836 for (i = 0; i < curr_dyn_buckets; i++) {
3837 ipfw_dyn_rule *p;
3838
3839 /*
3840 * The # of dynamic rules may have grown after the
3841 * snapshot of 'dyn_count' was taken, so we will have
3842 * to check 'dcount' (snapshot of dyn_count) here to
3843 * make sure that we don't overflow the pre-allocated
3844 * buffer.
3845 */
3846 for (p = ipfw_dyn_v[i]; p != NULL && dcount != 0;
3847 p = p->next, ioc_state++, dcount--, dcount2++)
3848 ipfw_copy_state(p, ioc_state);
3849 }
3850 skip:
3851 lockmgr(&dyn_lock, LK_RELEASE);
3852
3853 /*
3854 * The # of dynamic rules may be shrinked after the
3855 * snapshot of 'dyn_count' was taken. To give user a
3856 * correct dynamic rule count, we use the 'dcount2'
3857 * calculated above (with shared lockmgr lock held).
3858 */
3859 size = static_ioc_len +
3860 (dcount2 * sizeof(struct ipfw_ioc_state));
3861 KKASSERT(size <= old_size);
3862 }
3863
3864 sopt->sopt_valsize = size;
3865 return 0;
3866 }
3867
3868 static void
3869 ipfw_set_disable_dispatch(struct netmsg *nmsg)
3870 {
3871 struct lwkt_msg *lmsg = &nmsg->nm_lmsg;
3872 struct ipfw_context *ctx = ipfw_ctx[mycpuid];
3873
3874 ctx->ipfw_gen++;
3875 ctx->ipfw_set_disable = lmsg->u.ms_result32;
3876
3877 ifnet_forwardmsg(lmsg, mycpuid + 1);
3878 }
3879
3880 static void
3881 ipfw_ctl_set_disable(uint32_t disable, uint32_t enable)
3882 {
3883 struct netmsg nmsg;
3884 struct lwkt_msg *lmsg;
3885 uint32_t set_disable;
3886
3887 /* IPFW_DEFAULT_SET is always enabled */
3888 enable |= (1 << IPFW_DEFAULT_SET);
3889 set_disable = (ipfw_ctx[mycpuid]->ipfw_set_disable | disable) & ~enable;
3890
3891 bzero(&nmsg, sizeof(nmsg));
3892 netmsg_init(&nmsg, &curthread->td_msgport, 0, ipfw_set_disable_dispatch);
3893 lmsg = &nmsg.nm_lmsg;
3894 lmsg->u.ms_result32 = set_disable;
3895
3896 ifnet_domsg(lmsg, 0);
3897 }
3898
3899 /**
3900 * {set|get}sockopt parser.
3901 */
3902 static int
3903 ipfw_ctl(struct sockopt *sopt)
3904 {
3905 int error, rulenum;
3906 uint32_t *masks;
3907 size_t size;
3908
3909 error = 0;
3910
3911 switch (sopt->sopt_name) {
3912 case IP_FW_GET:
3913 error = ipfw_ctl_get_rules(sopt);
3914 break;
3915
3916 case IP_FW_FLUSH:
3917 ipfw_flush(0 /* keep default rule */);
3918 break;
3919
3920 case IP_FW_ADD:
3921 error = ipfw_ctl_add_rule(sopt);
3922 break;
3923
3924 case IP_FW_DEL:
3925 /*
3926 * IP_FW_DEL is used for deleting single rules or sets,
3927 * and (ab)used to atomically manipulate sets.
3928 * Argument size is used to distinguish between the two:
3929 * sizeof(uint32_t)
3930 * delete single rule or set of rules,
3931 * or reassign rules (or sets) to a different set.
3932 * 2 * sizeof(uint32_t)
3933 * atomic disable/enable sets.
3934 * first uint32_t contains sets to be disabled,
3935 * second uint32_t contains sets to be enabled.
3936 */
3937 masks = sopt->sopt_val;
3938 size = sopt->sopt_valsize;
3939 if (size == sizeof(*masks)) {
3940 /*
3941 * Delete or reassign static rule
3942 */
3943 error = ipfw_ctl_alter(masks[0]);
3944 } else if (size == (2 * sizeof(*masks))) {
3945 /*
3946 * Set enable/disable
3947 */
3948 ipfw_ctl_set_disable(masks[0], masks[1]);
3949 } else {
3950 error = EINVAL;
3951 }
3952 break;
3953
3954 case IP_FW_ZERO:
3955 case IP_FW_RESETLOG: /* argument is an int, the rule number */
3956 rulenum = 0;
3957
3958 if (sopt->sopt_val != 0) {
3959 error = soopt_to_kbuf(sopt, &rulenum,
3960 sizeof(int), sizeof(int));
3961 if (error)
3962 break;
3963 }
3964 error = ipfw_ctl_zero_entry(rulenum,
3965 sopt->sopt_name == IP_FW_RESETLOG);
3966 break;
3967
3968 default:
3969 kprintf("ipfw_ctl invalid option %d\n", sopt->sopt_name);
3970 error = EINVAL;
3971 }
3972 return error;
3973 }
3974
3975 /*
3976 * This procedure is only used to handle keepalives. It is invoked
3977 * every dyn_keepalive_period
3978 */
3979 static void
3980 ipfw_tick_dispatch(struct netmsg *nmsg)
3981 {
3982 time_t keep_alive;
3983 uint32_t gen;
3984 int i;
3985
3986 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
3987 KKASSERT(IPFW_LOADED);
3988
3989 /* Reply ASAP */
3990 crit_enter();
3991 lwkt_replymsg(&nmsg->nm_lmsg, 0);
3992 crit_exit();
3993
3994 if (ipfw_dyn_v == NULL || dyn_count == 0)
3995 goto done;
3996
3997 keep_alive = time_second;
3998
3999 lockmgr(&dyn_lock, LK_EXCLUSIVE);
4000 again:
4001 if (ipfw_dyn_v == NULL || dyn_count == 0) {
4002 lockmgr(&dyn_lock, LK_RELEASE);
4003 goto done;
4004 }
4005 gen = dyn_buckets_gen;
4006
4007 for (i = 0; i < curr_dyn_buckets; i++) {
4008 ipfw_dyn_rule *q, *prev;
4009
4010 for (prev = NULL, q = ipfw_dyn_v[i]; q != NULL;) {
4011 uint32_t ack_rev, ack_fwd;
4012 struct ipfw_flow_id id;
4013
4014 if (q->dyn_type == O_LIMIT_PARENT)
4015 goto next;
4016
4017 if (TIME_LEQ(q->expire, time_second)) {
4018 /* State expired */
4019 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
4020 continue;
4021 }
4022
4023 /*
4024 * Keep alive processing
4025 */
4026
4027 if (!dyn_keepalive)
4028 goto next;
4029 if (q->id.proto != IPPROTO_TCP)
4030 goto next;
4031 if ((q->state & BOTH_SYN) != BOTH_SYN)
4032 goto next;
4033 if (TIME_LEQ(time_second + dyn_keepalive_interval,
4034 q->expire))
4035 goto next; /* too early */
4036 if (q->keep_alive == keep_alive)
4037 goto next; /* alreay done */
4038
4039 /*
4040 * Save necessary information, so that they could
4041 * survive after possible blocking in send_pkt()
4042 */
4043 id = q->id;
4044 ack_rev = q->ack_rev;
4045 ack_fwd = q->ack_fwd;
4046
4047 /* Sending has been started */
4048 q->keep_alive = keep_alive;
4049
4050 /* Release lock to avoid possible dead lock */
4051 lockmgr(&dyn_lock, LK_RELEASE);
4052 send_pkt(&id, ack_rev - 1, ack_fwd, TH_SYN);
4053 send_pkt(&id, ack_fwd - 1, ack_rev, 0);
4054 lockmgr(&dyn_lock, LK_EXCLUSIVE);
4055
4056 if (gen != dyn_buckets_gen) {
4057 /*
4058 * Dyn bucket array has been changed during
4059 * the above two sending; reiterate.
4060 */
4061 goto again;
4062 }
4063 next:
4064 prev = q;
4065 q = q->next;
4066 }
4067 }
4068 lockmgr(&dyn_lock, LK_RELEASE);
4069 done:
4070 callout_reset(&ipfw_timeout_h, dyn_keepalive_period * hz,
4071 ipfw_tick, NULL);
4072 }
4073
4074 /*
4075 * This procedure is only used to handle keepalives. It is invoked
4076 * every dyn_keepalive_period
4077 */
4078 static void
4079 ipfw_tick(void *dummy __unused)
4080 {
4081 struct lwkt_msg *lmsg = &ipfw_timeout_netmsg.nm_lmsg;
4082
4083 KKASSERT(mycpuid == IPFW_CFGCPUID);
4084
4085 crit_enter();
4086
4087 KKASSERT(lmsg->ms_flags & MSGF_DONE);
4088 if (IPFW_LOADED) {
4089 lwkt_sendmsg(IPFW_CFGPORT, lmsg);
4090 /* ipfw_timeout_netmsg's handler reset this callout */
4091 }
4092
4093 crit_exit();
4094 }
4095
4096 static int
4097 ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir)
4098 {
4099 struct ip_fw_args args;
4100 struct mbuf *m = *m0;
4101 struct m_tag *mtag;
4102 int tee = 0, error = 0, ret;
4103
4104 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
4105 /* Extract info from dummynet tag */
4106 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
4107 KKASSERT(mtag != NULL);
4108 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv;
4109 KKASSERT(args.rule != NULL);
4110
4111 m_tag_delete(m, mtag);
4112 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
4113 } else {
4114 args.rule = NULL;
4115 }
4116
4117 args.eh = NULL;
4118 args.oif = NULL;
4119 args.m = m;
4120 ret = ipfw_chk(&args);
4121 m = args.m;
4122
4123 if (m == NULL) {
4124 error = EACCES;
4125 goto back;
4126 }
4127
4128 switch (ret) {
4129 case IP_FW_PASS:
4130 break;
4131
4132 case IP_FW_DENY:
4133 m_freem(m);
4134 m = NULL;
4135 error = EACCES;
4136 break;
4137
4138 case IP_FW_DUMMYNET:
4139 /* Send packet to the appropriate pipe */
4140 ipfw_dummynet_io(m, args.cookie, DN_TO_IP_IN, &args);
4141 break;
4142
4143 case IP_FW_TEE:
4144 tee = 1;
4145 /* FALL THROUGH */
4146
4147 case IP_FW_DIVERT:
4148 if (ip_divert_p != NULL) {
4149 m = ip_divert_p(m, tee, 1);
4150 } else {
4151 m_freem(m);
4152 m = NULL;
4153 /* not sure this is the right error msg */
4154 error = EACCES;
4155 }
4156 break;
4157
4158 default:
4159 panic("unknown ipfw return value: %d\n", ret);
4160 }
4161 back:
4162 *m0 = m;
4163 return error;
4164 }
4165
4166 static int
4167 ipfw_check_out(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir)
4168 {
4169 struct ip_fw_args args;
4170 struct mbuf *m = *m0;
4171 struct m_tag *mtag;
4172 int tee = 0, error = 0, ret;
4173
4174 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
4175 /* Extract info from dummynet tag */
4176 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
4177 KKASSERT(mtag != NULL);
4178 args.rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv;
4179 KKASSERT(args.rule != NULL);
4180
4181 m_tag_delete(m, mtag);
4182 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
4183 } else {
4184 args.rule = NULL;
4185 }
4186
4187 args.eh = NULL;
4188 args.m = m;
4189 args.oif = ifp;
4190 ret = ipfw_chk(&args);
4191 m = args.m;
4192
4193 if (m == NULL) {
4194 error = EACCES;
4195 goto back;
4196 }
4197
4198 switch (ret) {
4199 case IP_FW_PASS:
4200 break;
4201
4202 case IP_FW_DENY:
4203 m_freem(m);
4204 m = NULL;
4205 error = EACCES;
4206 break;
4207
4208 case IP_FW_DUMMYNET:
4209 ipfw_dummynet_io(m, args.cookie, DN_TO_IP_OUT, &args);
4210 break;
4211
4212 case IP_FW_TEE:
4213 tee = 1;
4214 /* FALL THROUGH */
4215
4216 case IP_FW_DIVERT:
4217 if (ip_divert_p != NULL) {
4218 m = ip_divert_p(m, tee, 0);
4219 } else {
4220 m_freem(m);
4221 m = NULL;
4222 /* not sure this is the right error msg */
4223 error = EACCES;
4224 }
4225 break;
4226
4227 default:
4228 panic("unknown ipfw return value: %d\n", ret);
4229 }
4230 back:
4231 *m0 = m;
4232 return error;
4233 }
4234
4235 static void
4236 ipfw_hook(void)
4237 {
4238 struct pfil_head *pfh;
4239
4240 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
4241
4242 pfh = pfil_head_get(PFIL_TYPE_AF, AF_INET);
4243 if (pfh == NULL)
4244 return;
4245
4246 pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_MPSAFE, pfh);
4247 pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_MPSAFE, pfh);
4248 }
4249
4250 static void
4251 ipfw_dehook(void)
4252 {
4253 struct pfil_head *pfh;
4254
4255 IPFW_ASSERT_CFGPORT(&curthread->td_msgport);
4256
4257 pfh = pfil_head_get(PFIL_TYPE_AF, AF_INET);
4258 if (pfh == NULL)
4259 return;
4260
4261 pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN, pfh);
4262 pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT, pfh);
4263 }
4264
4265 static void
4266 ipfw_sysctl_enable_dispatch(struct netmsg *nmsg)
4267 {
4268 struct lwkt_msg *lmsg = &nmsg->nm_lmsg;
4269 int enable = lmsg->u.ms_result;
4270
4271 if (fw_enable == enable)
4272 goto reply;
4273
4274 fw_enable = enable;
4275 if (fw_enable)
4276 ipfw_hook();
4277 else
4278 ipfw_dehook();
4279 reply:
4280 lwkt_replymsg(lmsg, 0);
4281 }
4282
4283 static int
4284 ipfw_sysctl_enable(SYSCTL_HANDLER_ARGS)
4285 {
4286 struct netmsg nmsg;
4287 struct lwkt_msg *lmsg;
4288 int enable, error;
4289
4290 enable = fw_enable;
4291 error = sysctl_handle_int(oidp, &enable, 0, req);
4292 if (error || req->newptr == NULL)
4293 return error;
4294
4295 netmsg_init(&nmsg, &curthread->td_msgport, 0,
4296 ipfw_sysctl_enable_dispatch);
4297 lmsg = &nmsg.nm_lmsg;
4298 lmsg->u.ms_result = enable;
4299
4300 return lwkt_domsg(IPFW_CFGPORT, lmsg, 0);
4301 }
4302
4303 static int
4304 ipfw_sysctl_autoinc_step(SYSCTL_HANDLER_ARGS)
4305 {
4306 return sysctl_int_range(oidp, arg1, arg2, req,
4307 IPFW_AUTOINC_STEP_MIN, IPFW_AUTOINC_STEP_MAX);
4308 }
4309
4310 static int
4311 ipfw_sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS)
4312 {
4313 int error, value;
4314
4315 lockmgr(&dyn_lock, LK_EXCLUSIVE);
4316
4317 value = dyn_buckets;
4318 error = sysctl_handle_int(oidp, &value, 0, req);
4319 if (error || !req->newptr)
4320 goto back;
4321
4322 /*
4323 * Make sure we have a power of 2 and
4324 * do not allow more than 64k entries.
4325 */
4326 error = EINVAL;
4327 if (value <= 1 || value > 65536)
4328 goto back;
4329 if ((value & (value - 1)) != 0)
4330 goto back;
4331
4332 error = 0;
4333 dyn_buckets = value;
4334 back:
4335 lockmgr(&dyn_lock, LK_RELEASE);
4336 return error;
4337 }
4338
4339 static int
4340 ipfw_sysctl_dyn_fin(SYSCTL_HANDLER_ARGS)
4341 {
4342 return sysctl_int_range(oidp, arg1, arg2, req,
4343 1, dyn_keepalive_period - 1);
4344 }
4345
4346 static int
4347 ipfw_sysctl_dyn_rst(SYSCTL_HANDLER_ARGS)
4348 {
4349 return sysctl_int_range(oidp, arg1, arg2, req,
4350 1, dyn_keepalive_period - 1);
4351 }
4352
4353 static void
4354 ipfw_ctx_init_dispatch(struct netmsg *nmsg)
4355 {
4356 struct netmsg_ipfw *fwmsg = (struct netmsg_ipfw *)nmsg;
4357 struct ipfw_context *ctx;
4358 struct ip_fw *def_rule;
4359
4360 ctx = kmalloc(sizeof(*ctx), M_IPFW, M_WAITOK | M_ZERO);
4361 ipfw_ctx[mycpuid] = ctx;
4362
4363 def_rule = kmalloc(sizeof(*def_rule), M_IPFW, M_WAITOK | M_ZERO);
4364
4365 def_rule->act_ofs = 0;
4366 def_rule->rulenum = IPFW_DEFAULT_RULE;
4367 def_rule->cmd_len = 1;
4368 def_rule->set = IPFW_DEFAULT_SET;
4369
4370 def_rule->cmd[0].len = 1;
4371 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
4372 def_rule->cmd[0].opcode = O_ACCEPT;
4373 #else
4374 def_rule->cmd[0].opcode = O_DENY;
4375 #endif
4376
4377 def_rule->refcnt = 1;
4378 def_rule->cpuid = mycpuid;
4379
4380 /* Install the default rule */
4381 ctx->ipfw_default_rule = def_rule;
4382 ctx->ipfw_layer3_chain = def_rule;
4383
4384 /* Link rule CPU sibling */
4385 ipfw_link_sibling(fwmsg, def_rule);
4386
4387 /* Statistics only need to be updated once */
4388 if (mycpuid == 0)
4389 ipfw_inc_static_count(def_rule);
4390
4391 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
4392 }
4393
4394 static void
4395 ipfw_init_dispatch(struct netmsg *nmsg)
4396 {
4397 struct netmsg_ipfw fwmsg;
4398 int error = 0;
4399
4400 if (IPFW_LOADED) {
4401 kprintf("IP firewall already loaded\n");
4402 error = EEXIST;
4403 goto reply;
4404 }
4405
4406 bzero(&fwmsg, sizeof(fwmsg));
4407 netmsg_init(&fwmsg.nmsg, &curthread->td_msgport, 0,
4408 ipfw_ctx_init_dispatch);
4409 ifnet_domsg(&fwmsg.nmsg.nm_lmsg, 0);
4410
4411 ip_fw_chk_ptr = ipfw_chk;
4412 ip_fw_ctl_ptr = ipfw_ctl;
4413 ip_fw_dn_io_ptr = ipfw_dummynet_io;
4414
4415 kprintf("ipfw2 initialized, default to %s, logging ",
4416 ipfw_ctx[mycpuid]->ipfw_default_rule->cmd[0].opcode ==
4417 O_ACCEPT ? "accept" : "deny");
4418
4419 #ifdef IPFIREWALL_VERBOSE
4420 fw_verbose = 1;
4421 #endif
4422 #ifdef IPFIREWALL_VERBOSE_LIMIT
4423 verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
4424 #endif
4425 if (fw_verbose == 0) {
4426 kprintf("disabled\n");
4427 } else if (verbose_limit == 0) {
4428 kprintf("unlimited\n");
4429 } else {
4430 kprintf("limited to %d packets/entry by default\n",
4431 verbose_limit);
4432 }
4433
4434 callout_init_mp(&ipfw_timeout_h);
4435 netmsg_init(&ipfw_timeout_netmsg, &netisr_adone_rport,
4436 MSGF_MPSAFE | MSGF_DROPABLE | MSGF_PRIORITY,
4437 ipfw_tick_dispatch);
4438 lockinit(&dyn_lock, "ipfw_dyn", 0, 0);
4439
4440 ip_fw_loaded = 1;
4441 callout_reset(&ipfw_timeout_h, hz, ipfw_tick, NULL);
4442
4443 if (fw_enable)
4444 ipfw_hook();
4445 reply:
4446 lwkt_replymsg(&nmsg->nm_lmsg, error);
4447 }
4448
4449 static int
4450 ipfw_init(void)
4451 {
4452 struct netmsg smsg;
4453
4454 netmsg_init(&smsg, &curthread->td_msgport, 0, ipfw_init_dispatch);
4455 return lwkt_domsg(IPFW_CFGPORT, &smsg.nm_lmsg, 0);
4456 }
4457
4458 #ifdef KLD_MODULE
4459
4460 static void
4461 ipfw_fini_dispatch(struct netmsg *nmsg)
4462 {
4463 int error = 0, cpu;
4464
4465 if (ipfw_refcnt != 0) {
4466 error = EBUSY;
4467 goto reply;
4468 }
4469
4470 ip_fw_loaded = 0;
4471
4472 ipfw_dehook();
4473 callout_stop(&ipfw_timeout_h);
4474
4475 netmsg_service_sync();
4476
4477 crit_enter();
4478 if ((ipfw_timeout_netmsg.nm_lmsg.ms_flags & MSGF_DONE) == 0) {
4479 /*
4480 * Callout message is pending; drop it
4481 */
4482 lwkt_dropmsg(&ipfw_timeout_netmsg.nm_lmsg);
4483 }
4484 crit_exit();
4485
4486 ip_fw_chk_ptr = NULL;
4487 ip_fw_ctl_ptr = NULL;
4488 ip_fw_dn_io_ptr = NULL;
4489 ipfw_flush(1 /* kill default rule */);
4490
4491 /* Free pre-cpu context */
4492 for (cpu = 0; cpu < ncpus; ++cpu)
4493 kfree(ipfw_ctx[cpu], M_IPFW);
4494
4495 kprintf("IP firewall unloaded\n");
4496 reply:
4497 lwkt_replymsg(&nmsg->nm_lmsg, error);
4498 }
4499
4500 static int
4501 ipfw_fini(void)
4502 {
4503 struct netmsg smsg;
4504
4505 netmsg_init(&smsg, &curthread->td_msgport, 0, ipfw_fini_dispatch);
4506 return lwkt_domsg(IPFW_CFGPORT, &smsg.nm_lmsg, 0);
4507 }
4508
4509 #endif /* KLD_MODULE */
4510
4511 static int
4512 ipfw_modevent(module_t mod, int type, void *unused)
4513 {
4514 int err = 0;
4515
4516 switch (type) {
4517 case MOD_LOAD:
4518 err = ipfw_init();
4519 break;
4520
4521 case MOD_UNLOAD:
4522 #ifndef KLD_MODULE
4523 kprintf("ipfw statically compiled, cannot unload\n");
4524 err = EBUSY;
4525 #else
4526 err = ipfw_fini();
4527 #endif
4528 break;
4529 default:
4530 break;
4531 }
4532 return err;
4533 }
4534
4535 static moduledata_t ipfwmod = {
4536 "ipfw",
4537 ipfw_modevent,
4538 0
4539 };
4540 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_END, SI_ORDER_ANY);
4541 MODULE_VERSION(ipfw, 1);
DragonFly BSD