1 /* $FreeBSD$ */
2
3 /*
4 * Copyright (C) 2012 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 */
8 #if defined(KERNEL) || defined(_KERNEL)
9 # undef KERNEL
10 # undef _KERNEL
11 # define KERNEL 1
12 # define _KERNEL 1
13 #endif
14 #include <sys/errno.h>
15 #include <sys/types.h>
16 #include <sys/param.h>
17 #include <sys/time.h>
18 #include <sys/file.h>
19 #ifdef __hpux
20 # include <sys/timeout.h>
21 #endif
22 #if !defined(_KERNEL)
23 # include <stdio.h>
24 # include <string.h>
25 # include <stdlib.h>
26 # define _KERNEL
27 # ifdef __OpenBSD__
28 struct file;
29 # endif
30 # include <sys/uio.h>
31 # undef _KERNEL
32 #endif
33 #if defined(_KERNEL) && \
34 defined(__FreeBSD_version) && (__FreeBSD_version >= 220000)
35 # include <sys/filio.h>
36 # include <sys/fcntl.h>
37 #else
38 # include <sys/ioctl.h>
39 #endif
40 #if !defined(linux)
41 # include <sys/protosw.h>
42 #endif
43 #include <sys/socket.h>
44 #if defined(_KERNEL)
45 # include <sys/systm.h>
46 # if !defined(__SVR4) && !defined(__svr4__)
47 # include <sys/mbuf.h>
48 # endif
49 #endif
50 #if !defined(__SVR4) && !defined(__svr4__)
51 # if defined(_KERNEL) && !defined(__sgi) && !defined(AIX)
52 # include <sys/kernel.h>
53 # endif
54 #else
55 # include <sys/byteorder.h>
56 # ifdef _KERNEL
57 # include <sys/dditypes.h>
58 # endif
59 # include <sys/stream.h>
60 # include <sys/kmem.h>
61 #endif
62 #include <net/if.h>
63 #ifdef sun
64 # include <net/af.h>
65 #endif
66 #include <netinet/in.h>
67 #include <netinet/in_systm.h>
68 #include <netinet/ip.h>
69 #if !defined(linux)
70 # include <netinet/ip_var.h>
71 #endif
72 #include <netinet/tcp.h>
73 #include <netinet/udp.h>
74 #include <netinet/ip_icmp.h>
75 #include "netinet/ip_compat.h"
76 #include <netinet/tcpip.h>
77 #include "netinet/ip_fil.h"
78 #include "netinet/ip_nat.h"
79 #include "netinet/ip_frag.h"
80 #include "netinet/ip_state.h"
81 #include "netinet/ip_auth.h"
82 #include "netinet/ip_lookup.h"
83 #include "netinet/ip_proxy.h"
84 #include "netinet/ip_sync.h"
85 /* END OF INCLUDES */
86
87 #if !defined(lint)
88 static const char sccsid[] = "@(#)ip_frag.c 1.11 3/24/96 (C) 1993-2000 Darren Reed";
89 static const char rcsid[] = "@(#)$FreeBSD$";
90 /* static const char rcsid[] = "@(#)$Id: ip_frag.c,v 2.77.2.12 2007/09/20 12:51:51 darrenr Exp $"; */
91 #endif
92
93
94 #ifdef USE_MUTEXES
95 static ipfr_t *ipfr_frag_new __P((ipf_main_softc_t *, ipf_frag_softc_t *,
96 fr_info_t *, u_32_t, ipfr_t **,
97 ipfrwlock_t *));
98 static ipfr_t *ipf_frag_lookup __P((ipf_main_softc_t *, ipf_frag_softc_t *, fr_info_t *, ipfr_t **, ipfrwlock_t *));
99 static void ipf_frag_deref __P((void *, ipfr_t **, ipfrwlock_t *));
100 static int ipf_frag_next __P((ipf_main_softc_t *, ipftoken_t *, ipfgeniter_t *,
101 ipfr_t **, ipfrwlock_t *));
102 #else
103 static ipfr_t *ipfr_frag_new __P((ipf_main_softc_t *, ipf_frag_softc_t *,
104 fr_info_t *, u_32_t, ipfr_t **));
105 static ipfr_t *ipf_frag_lookup __P((ipf_main_softc_t *, ipf_frag_softc_t *, fr_info_t *, ipfr_t **));
106 static void ipf_frag_deref __P((void *, ipfr_t **));
107 static int ipf_frag_next __P((ipf_main_softc_t *, ipftoken_t *, ipfgeniter_t *,
108 ipfr_t **));
109 #endif
110 static void ipf_frag_delete __P((ipf_main_softc_t *, ipfr_t *, ipfr_t ***));
111 static void ipf_frag_free __P((ipf_frag_softc_t *, ipfr_t *));
112
113 static frentry_t ipfr_block;
114
115 const ipftuneable_t ipf_tuneables[] = {
116 { { (void *)offsetof(ipf_frag_softc_t, ipfr_size) },
117 "frag_size", 1, 0x7fffffff,
118 stsizeof(ipf_frag_softc_t, ipfr_size),
119 IPFT_WRDISABLED, NULL, NULL },
120 { { (void *)offsetof(ipf_frag_softc_t, ipfr_ttl) },
121 "frag_ttl", 1, 0x7fffffff,
122 stsizeof(ipf_frag_softc_t, ipfr_ttl),
123 0, NULL, NULL },
124 { { NULL },
125 NULL, 0, 0,
126 0,
127 0, NULL, NULL }
128 };
129
130 #define FBUMP(x) softf->ipfr_stats.x++
131 #define FBUMPD(x) do { softf->ipfr_stats.x++; DT(x); } while (0)
132
133
134 /* ------------------------------------------------------------------------ */
135 /* Function: ipf_frag_main_load */
136 /* Returns: int - 0 == success, -1 == error */
137 /* Parameters: Nil */
138 /* */
139 /* Initialise the filter rule associted with blocked packets - everyone can */
140 /* use it. */
141 /* ------------------------------------------------------------------------ */
142 int
ipf_frag_main_load()143 ipf_frag_main_load()
144 {
145 bzero((char *)&ipfr_block, sizeof(ipfr_block));
146 ipfr_block.fr_flags = FR_BLOCK|FR_QUICK;
147 ipfr_block.fr_ref = 1;
148
149 return 0;
150 }
151
152
153 /* ------------------------------------------------------------------------ */
154 /* Function: ipf_frag_main_unload */
155 /* Returns: int - 0 == success, -1 == error */
156 /* Parameters: Nil */
157 /* */
158 /* A null-op function that exists as a placeholder so that the flow in */
159 /* other functions is obvious. */
160 /* ------------------------------------------------------------------------ */
161 int
ipf_frag_main_unload()162 ipf_frag_main_unload()
163 {
164 return 0;
165 }
166
167
168 /* ------------------------------------------------------------------------ */
169 /* Function: ipf_frag_soft_create */
170 /* Returns: void * - NULL = failure, else pointer to local context */
171 /* Parameters: softc(I) - pointer to soft context main structure */
172 /* */
173 /* Allocate a new soft context structure to track fragment related info. */
174 /* ------------------------------------------------------------------------ */
175 /*ARGSUSED*/
176 void *
ipf_frag_soft_create(softc)177 ipf_frag_soft_create(softc)
178 ipf_main_softc_t *softc;
179 {
180 ipf_frag_softc_t *softf;
181
182 KMALLOC(softf, ipf_frag_softc_t *);
183 if (softf == NULL)
184 return NULL;
185
186 bzero((char *)softf, sizeof(*softf));
187
188 RWLOCK_INIT(&softf->ipfr_ipidfrag, "frag ipid lock");
189 RWLOCK_INIT(&softf->ipfr_frag, "ipf fragment rwlock");
190 RWLOCK_INIT(&softf->ipfr_natfrag, "ipf NAT fragment rwlock");
191
192 softf->ipfr_size = IPFT_SIZE;
193 softf->ipfr_ttl = IPF_TTLVAL(60);
194 softf->ipfr_lock = 1;
195 softf->ipfr_tail = &softf->ipfr_list;
196 softf->ipfr_nattail = &softf->ipfr_natlist;
197 softf->ipfr_ipidtail = &softf->ipfr_ipidlist;
198
199 return softf;
200 }
201
202
203 /* ------------------------------------------------------------------------ */
204 /* Function: ipf_frag_soft_destroy */
205 /* Returns: Nil */
206 /* Parameters: softc(I) - pointer to soft context main structure */
207 /* arg(I) - pointer to local context to use */
208 /* */
209 /* Initialise the hash tables for the fragment cache lookups. */
210 /* ------------------------------------------------------------------------ */
211 void
ipf_frag_soft_destroy(softc,arg)212 ipf_frag_soft_destroy(softc, arg)
213 ipf_main_softc_t *softc;
214 void *arg;
215 {
216 ipf_frag_softc_t *softf = arg;
217
218 RW_DESTROY(&softf->ipfr_ipidfrag);
219 RW_DESTROY(&softf->ipfr_frag);
220 RW_DESTROY(&softf->ipfr_natfrag);
221
222 KFREE(softf);
223 }
224
225
226 /* ------------------------------------------------------------------------ */
227 /* Function: ipf_frag_soft_init */
228 /* Returns: int - 0 == success, -1 == error */
229 /* Parameters: softc(I) - pointer to soft context main structure */
230 /* arg(I) - pointer to local context to use */
231 /* */
232 /* Initialise the hash tables for the fragment cache lookups. */
233 /* ------------------------------------------------------------------------ */
234 /*ARGSUSED*/
235 int
ipf_frag_soft_init(softc,arg)236 ipf_frag_soft_init(softc, arg)
237 ipf_main_softc_t *softc;
238 void *arg;
239 {
240 ipf_frag_softc_t *softf = arg;
241
242 KMALLOCS(softf->ipfr_heads, ipfr_t **,
243 softf->ipfr_size * sizeof(ipfr_t *));
244 if (softf->ipfr_heads == NULL)
245 return -1;
246
247 bzero((char *)softf->ipfr_heads, softf->ipfr_size * sizeof(ipfr_t *));
248
249 KMALLOCS(softf->ipfr_nattab, ipfr_t **,
250 softf->ipfr_size * sizeof(ipfr_t *));
251 if (softf->ipfr_nattab == NULL)
252 return -2;
253
254 bzero((char *)softf->ipfr_nattab, softf->ipfr_size * sizeof(ipfr_t *));
255
256 KMALLOCS(softf->ipfr_ipidtab, ipfr_t **,
257 softf->ipfr_size * sizeof(ipfr_t *));
258 if (softf->ipfr_ipidtab == NULL)
259 return -3;
260
261 bzero((char *)softf->ipfr_ipidtab,
262 softf->ipfr_size * sizeof(ipfr_t *));
263
264 softf->ipfr_lock = 0;
265 softf->ipfr_inited = 1;
266
267 return 0;
268 }
269
270
271 /* ------------------------------------------------------------------------ */
272 /* Function: ipf_frag_soft_fini */
273 /* Returns: int - 0 == success, -1 == error */
274 /* Parameters: softc(I) - pointer to soft context main structure */
275 /* arg(I) - pointer to local context to use */
276 /* */
277 /* Free all memory allocated whilst running and from initialisation. */
278 /* ------------------------------------------------------------------------ */
279 int
ipf_frag_soft_fini(softc,arg)280 ipf_frag_soft_fini(softc, arg)
281 ipf_main_softc_t *softc;
282 void *arg;
283 {
284 ipf_frag_softc_t *softf = arg;
285
286 softf->ipfr_lock = 1;
287
288 if (softf->ipfr_inited == 1) {
289 ipf_frag_clear(softc);
290
291 softf->ipfr_inited = 0;
292 }
293
294 if (softf->ipfr_heads != NULL)
295 KFREES(softf->ipfr_heads,
296 softf->ipfr_size * sizeof(ipfr_t *));
297 softf->ipfr_heads = NULL;
298
299 if (softf->ipfr_nattab != NULL)
300 KFREES(softf->ipfr_nattab,
301 softf->ipfr_size * sizeof(ipfr_t *));
302 softf->ipfr_nattab = NULL;
303
304 if (softf->ipfr_ipidtab != NULL)
305 KFREES(softf->ipfr_ipidtab,
306 softf->ipfr_size * sizeof(ipfr_t *));
307 softf->ipfr_ipidtab = NULL;
308
309 return 0;
310 }
311
312
313 /* ------------------------------------------------------------------------ */
314 /* Function: ipf_frag_set_lock */
315 /* Returns: Nil */
316 /* Parameters: arg(I) - pointer to local context to use */
317 /* tmp(I) - new value for lock */
318 /* */
319 /* Stub function that allows for external manipulation of ipfr_lock */
320 /* ------------------------------------------------------------------------ */
321 void
ipf_frag_setlock(arg,tmp)322 ipf_frag_setlock(arg, tmp)
323 void *arg;
324 int tmp;
325 {
326 ipf_frag_softc_t *softf = arg;
327
328 softf->ipfr_lock = tmp;
329 }
330
331
332 /* ------------------------------------------------------------------------ */
333 /* Function: ipf_frag_stats */
334 /* Returns: ipfrstat_t* - pointer to struct with current frag stats */
335 /* Parameters: arg(I) - pointer to local context to use */
336 /* */
337 /* Updates ipfr_stats with current information and returns a pointer to it */
338 /* ------------------------------------------------------------------------ */
339 ipfrstat_t *
ipf_frag_stats(arg)340 ipf_frag_stats(arg)
341 void *arg;
342 {
343 ipf_frag_softc_t *softf = arg;
344
345 softf->ipfr_stats.ifs_table = softf->ipfr_heads;
346 softf->ipfr_stats.ifs_nattab = softf->ipfr_nattab;
347 return &softf->ipfr_stats;
348 }
349
350
351 /* ------------------------------------------------------------------------ */
352 /* Function: ipfr_frag_new */
353 /* Returns: ipfr_t * - pointer to fragment cache state info or NULL */
354 /* Parameters: fin(I) - pointer to packet information */
355 /* table(I) - pointer to frag table to add to */
356 /* lock(I) - pointer to lock to get a write hold of */
357 /* */
358 /* Add a new entry to the fragment cache, registering it as having come */
359 /* through this box, with the result of the filter operation. */
360 /* */
361 /* If this function succeeds, it returns with a write lock held on "lock". */
362 /* If it fails, no lock is held on return. */
363 /* ------------------------------------------------------------------------ */
364 static ipfr_t *
ipfr_frag_new(softc,softf,fin,pass,table,lock)365 ipfr_frag_new(softc, softf, fin, pass, table
366 #ifdef USE_MUTEXES
367 , lock
368 #endif
369 )
370 ipf_main_softc_t *softc;
371 ipf_frag_softc_t *softf;
372 fr_info_t *fin;
373 u_32_t pass;
374 ipfr_t *table[];
375 #ifdef USE_MUTEXES
376 ipfrwlock_t *lock;
377 #endif
378 {
379 ipfr_t *fra, frag, *fran;
380 u_int idx, off;
381 frentry_t *fr;
382
383 if (softf->ipfr_stats.ifs_inuse >= softf->ipfr_size) {
384 FBUMPD(ifs_maximum);
385 return NULL;
386 }
387
388 if ((fin->fin_flx & (FI_FRAG|FI_BAD)) != FI_FRAG) {
389 FBUMPD(ifs_newbad);
390 return NULL;
391 }
392
393 if (pass & FR_FRSTRICT) {
394 if (fin->fin_off != 0) {
395 FBUMPD(ifs_newrestrictnot0);
396 return NULL;
397 }
398 }
399
400 frag.ipfr_v = fin->fin_v;
401 idx = fin->fin_v;
402 frag.ipfr_p = fin->fin_p;
403 idx += fin->fin_p;
404 frag.ipfr_id = fin->fin_id;
405 idx += fin->fin_id;
406 frag.ipfr_source = fin->fin_fi.fi_src;
407 idx += frag.ipfr_src.s_addr;
408 frag.ipfr_dest = fin->fin_fi.fi_dst;
409 idx += frag.ipfr_dst.s_addr;
410 frag.ipfr_ifp = fin->fin_ifp;
411 idx *= 127;
412 idx %= softf->ipfr_size;
413
414 frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY;
415 frag.ipfr_secmsk = fin->fin_fi.fi_secmsk;
416 frag.ipfr_auth = fin->fin_fi.fi_auth;
417
418 off = fin->fin_off >> 3;
419 if (off == 0) {
420 char *ptr;
421 int end;
422
423 #ifdef USE_INET6
424 if (fin->fin_v == 6) {
425
426 ptr = (char *)fin->fin_fraghdr +
427 sizeof(struct ip6_frag);
428 } else
429 #endif
430 {
431 ptr = fin->fin_dp;
432 }
433 end = fin->fin_plen - (ptr - (char *)fin->fin_ip);
434 frag.ipfr_firstend = end >> 3;
435 } else {
436 frag.ipfr_firstend = 0;
437 }
438
439 /*
440 * allocate some memory, if possible, if not, just record that we
441 * failed to do so.
442 */
443 KMALLOC(fran, ipfr_t *);
444 if (fran == NULL) {
445 FBUMPD(ifs_nomem);
446 return NULL;
447 }
448
449 WRITE_ENTER(lock);
450
451 /*
452 * first, make sure it isn't already there...
453 */
454 for (fra = table[idx]; (fra != NULL); fra = fra->ipfr_hnext)
455 if (!bcmp((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp,
456 IPFR_CMPSZ)) {
457 RWLOCK_EXIT(lock);
458 FBUMPD(ifs_exists);
459 KFREE(fra);
460 return NULL;
461 }
462
463 fra = fran;
464 fran = NULL;
465 fr = fin->fin_fr;
466 fra->ipfr_rule = fr;
467 if (fr != NULL) {
468 MUTEX_ENTER(&fr->fr_lock);
469 fr->fr_ref++;
470 MUTEX_EXIT(&fr->fr_lock);
471 }
472
473 /*
474 * Insert the fragment into the fragment table, copy the struct used
475 * in the search using bcopy rather than reassign each field.
476 * Set the ttl to the default.
477 */
478 if ((fra->ipfr_hnext = table[idx]) != NULL)
479 table[idx]->ipfr_hprev = &fra->ipfr_hnext;
480 fra->ipfr_hprev = table + idx;
481 fra->ipfr_data = NULL;
482 table[idx] = fra;
483 bcopy((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, IPFR_CMPSZ);
484 fra->ipfr_v = fin->fin_v;
485 fra->ipfr_ttl = softc->ipf_ticks + softf->ipfr_ttl;
486 fra->ipfr_firstend = frag.ipfr_firstend;
487
488 /*
489 * Compute the offset of the expected start of the next packet.
490 */
491 if (off == 0)
492 fra->ipfr_seen0 = 1;
493 fra->ipfr_off = off + (fin->fin_dlen >> 3);
494 fra->ipfr_pass = pass;
495 fra->ipfr_ref = 1;
496 fra->ipfr_pkts = 1;
497 fra->ipfr_bytes = fin->fin_plen;
498 FBUMP(ifs_inuse);
499 FBUMP(ifs_new);
500 return fra;
501 }
502
503
504 /* ------------------------------------------------------------------------ */
505 /* Function: ipf_frag_new */
506 /* Returns: int - 0 == success, -1 == error */
507 /* Parameters: fin(I) - pointer to packet information */
508 /* */
509 /* Add a new entry to the fragment cache table based on the current packet */
510 /* ------------------------------------------------------------------------ */
511 int
ipf_frag_new(softc,fin,pass)512 ipf_frag_new(softc, fin, pass)
513 ipf_main_softc_t *softc;
514 u_32_t pass;
515 fr_info_t *fin;
516 {
517 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
518 ipfr_t *fra;
519
520 if (softf->ipfr_lock != 0)
521 return -1;
522
523 #ifdef USE_MUTEXES
524 fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_heads, &softc->ipf_frag);
525 #else
526 fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_heads);
527 #endif
528 if (fra != NULL) {
529 *softf->ipfr_tail = fra;
530 fra->ipfr_prev = softf->ipfr_tail;
531 softf->ipfr_tail = &fra->ipfr_next;
532 fra->ipfr_next = NULL;
533 RWLOCK_EXIT(&softc->ipf_frag);
534 }
535 return fra ? 0 : -1;
536 }
537
538
539 /* ------------------------------------------------------------------------ */
540 /* Function: ipf_frag_natnew */
541 /* Returns: int - 0 == success, -1 == error */
542 /* Parameters: fin(I) - pointer to packet information */
543 /* nat(I) - pointer to NAT structure */
544 /* */
545 /* Create a new NAT fragment cache entry based on the current packet and */
546 /* the NAT structure for this "session". */
547 /* ------------------------------------------------------------------------ */
548 int
ipf_frag_natnew(softc,fin,pass,nat)549 ipf_frag_natnew(softc, fin, pass, nat)
550 ipf_main_softc_t *softc;
551 fr_info_t *fin;
552 u_32_t pass;
553 nat_t *nat;
554 {
555 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
556 ipfr_t *fra;
557
558 if (softf->ipfr_lock != 0)
559 return 0;
560
561 #ifdef USE_MUTEXES
562 fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_nattab,
563 &softf->ipfr_natfrag);
564 #else
565 fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_nattab);
566 #endif
567 if (fra != NULL) {
568 fra->ipfr_data = nat;
569 nat->nat_data = fra;
570 *softf->ipfr_nattail = fra;
571 fra->ipfr_prev = softf->ipfr_nattail;
572 softf->ipfr_nattail = &fra->ipfr_next;
573 fra->ipfr_next = NULL;
574 RWLOCK_EXIT(&softf->ipfr_natfrag);
575 return 0;
576 }
577 return -1;
578 }
579
580
581 /* ------------------------------------------------------------------------ */
582 /* Function: ipf_frag_ipidnew */
583 /* Returns: int - 0 == success, -1 == error */
584 /* Parameters: fin(I) - pointer to packet information */
585 /* ipid(I) - new IP ID for this fragmented packet */
586 /* */
587 /* Create a new fragment cache entry for this packet and store, as a data */
588 /* pointer, the new IP ID value. */
589 /* ------------------------------------------------------------------------ */
590 int
ipf_frag_ipidnew(fin,ipid)591 ipf_frag_ipidnew(fin, ipid)
592 fr_info_t *fin;
593 u_32_t ipid;
594 {
595 ipf_main_softc_t *softc = fin->fin_main_soft;
596 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
597 ipfr_t *fra;
598
599 if (softf->ipfr_lock)
600 return 0;
601
602 #ifdef USE_MUTEXES
603 fra = ipfr_frag_new(softc, softf, fin, 0, softf->ipfr_ipidtab, &softf->ipfr_ipidfrag);
604 #else
605 fra = ipfr_frag_new(softc, softf, fin, 0, softf->ipfr_ipidtab);
606 #endif
607 if (fra != NULL) {
608 fra->ipfr_data = (void *)(intptr_t)ipid;
609 *softf->ipfr_ipidtail = fra;
610 fra->ipfr_prev = softf->ipfr_ipidtail;
611 softf->ipfr_ipidtail = &fra->ipfr_next;
612 fra->ipfr_next = NULL;
613 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
614 }
615 return fra ? 0 : -1;
616 }
617
618
619 /* ------------------------------------------------------------------------ */
620 /* Function: ipf_frag_lookup */
621 /* Returns: ipfr_t * - pointer to ipfr_t structure if there's a */
622 /* matching entry in the frag table, else NULL */
623 /* Parameters: fin(I) - pointer to packet information */
624 /* table(I) - pointer to fragment cache table to search */
625 /* */
626 /* Check the fragment cache to see if there is already a record of this */
627 /* packet with its filter result known. */
628 /* */
629 /* If this function succeeds, it returns with a write lock held on "lock". */
630 /* If it fails, no lock is held on return. */
631 /* ------------------------------------------------------------------------ */
632 static ipfr_t *
ipf_frag_lookup(softc,softf,fin,table,lock)633 ipf_frag_lookup(softc, softf, fin, table
634 #ifdef USE_MUTEXES
635 , lock
636 #endif
637 )
638 ipf_main_softc_t *softc;
639 ipf_frag_softc_t *softf;
640 fr_info_t *fin;
641 ipfr_t *table[];
642 #ifdef USE_MUTEXES
643 ipfrwlock_t *lock;
644 #endif
645 {
646 ipfr_t *f, frag;
647 u_int idx;
648
649 /*
650 * We don't want to let short packets match because they could be
651 * compromising the security of other rules that want to match on
652 * layer 4 fields (and can't because they have been fragmented off.)
653 * Why do this check here? The counter acts as an indicator of this
654 * kind of attack, whereas if it was elsewhere, it wouldn't know if
655 * other matching packets had been seen.
656 */
657 if (fin->fin_flx & FI_SHORT) {
658 FBUMPD(ifs_short);
659 return NULL;
660 }
661
662 if ((fin->fin_flx & FI_BAD) != 0) {
663 FBUMPD(ifs_bad);
664 return NULL;
665 }
666
667 /*
668 * For fragments, we record protocol, packet id, TOS and both IP#'s
669 * (these should all be the same for all fragments of a packet).
670 *
671 * build up a hash value to index the table with.
672 */
673 frag.ipfr_v = fin->fin_v;
674 idx = fin->fin_v;
675 frag.ipfr_p = fin->fin_p;
676 idx += fin->fin_p;
677 frag.ipfr_id = fin->fin_id;
678 idx += fin->fin_id;
679 frag.ipfr_source = fin->fin_fi.fi_src;
680 idx += frag.ipfr_src.s_addr;
681 frag.ipfr_dest = fin->fin_fi.fi_dst;
682 idx += frag.ipfr_dst.s_addr;
683 frag.ipfr_ifp = fin->fin_ifp;
684 idx *= 127;
685 idx %= softf->ipfr_size;
686
687 frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY;
688 frag.ipfr_secmsk = fin->fin_fi.fi_secmsk;
689 frag.ipfr_auth = fin->fin_fi.fi_auth;
690
691 READ_ENTER(lock);
692
693 /*
694 * check the table, careful to only compare the right amount of data
695 */
696 for (f = table[idx]; f; f = f->ipfr_hnext) {
697 if (!bcmp((char *)&frag.ipfr_ifp, (char *)&f->ipfr_ifp,
698 IPFR_CMPSZ)) {
699 u_short off;
700
701 /*
702 * XXX - We really need to be guarding against the
703 * retransmission of (src,dst,id,offset-range) here
704 * because a fragmented packet is never resent with
705 * the same IP ID# (or shouldn't).
706 */
707 off = fin->fin_off >> 3;
708 if (f->ipfr_seen0) {
709 if (off == 0) {
710 FBUMPD(ifs_retrans0);
711 continue;
712 }
713
714 /*
715 * Case 3. See comment for frpr_fragment6.
716 */
717 if ((f->ipfr_firstend != 0) &&
718 (off < f->ipfr_firstend)) {
719 FBUMP(ifs_overlap);
720 DT2(ifs_overlap, u_short, off,
721 ipfr_t *, f);
722 fin->fin_flx |= FI_BAD;
723 break;
724 }
725 } else if (off == 0)
726 f->ipfr_seen0 = 1;
727
728 if (f != table[idx]) {
729 ipfr_t **fp;
730
731 /*
732 * Move fragment info. to the top of the list
733 * to speed up searches. First, delink...
734 */
735 fp = f->ipfr_hprev;
736 (*fp) = f->ipfr_hnext;
737 if (f->ipfr_hnext != NULL)
738 f->ipfr_hnext->ipfr_hprev = fp;
739 /*
740 * Then put back at the top of the chain.
741 */
742 f->ipfr_hnext = table[idx];
743 table[idx]->ipfr_hprev = &f->ipfr_hnext;
744 f->ipfr_hprev = table + idx;
745 table[idx] = f;
746 }
747
748 /*
749 * If we've follwed the fragments, and this is the
750 * last (in order), shrink expiration time.
751 */
752 if (off == f->ipfr_off) {
753 f->ipfr_off = (fin->fin_dlen >> 3) + off;
754
755 /*
756 * Well, we could shrink the expiration time
757 * but only if every fragment has been seen
758 * in order upto this, the last. ipfr_badorder
759 * is used here to count those out of order
760 * and if it equals 0 when we get to the last
761 * fragment then we can assume all of the
762 * fragments have been seen and in order.
763 */
764 #if 0
765 /*
766 * Doing this properly requires moving it to
767 * the head of the list which is infesible.
768 */
769 if ((more == 0) && (f->ipfr_badorder == 0))
770 f->ipfr_ttl = softc->ipf_ticks + 1;
771 #endif
772 } else {
773 f->ipfr_badorder++;
774 FBUMPD(ifs_unordered);
775 if (f->ipfr_pass & FR_FRSTRICT) {
776 FBUMPD(ifs_strict);
777 continue;
778 }
779 }
780 f->ipfr_pkts++;
781 f->ipfr_bytes += fin->fin_plen;
782 FBUMP(ifs_hits);
783 return f;
784 }
785 }
786
787 RWLOCK_EXIT(lock);
788 FBUMP(ifs_miss);
789 return NULL;
790 }
791
792
793 /* ------------------------------------------------------------------------ */
794 /* Function: ipf_frag_natknown */
795 /* Returns: nat_t* - pointer to 'parent' NAT structure if frag table */
796 /* match found, else NULL */
797 /* Parameters: fin(I) - pointer to packet information */
798 /* */
799 /* Functional interface for NAT lookups of the NAT fragment cache */
800 /* ------------------------------------------------------------------------ */
801 nat_t *
ipf_frag_natknown(fin)802 ipf_frag_natknown(fin)
803 fr_info_t *fin;
804 {
805 ipf_main_softc_t *softc = fin->fin_main_soft;
806 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
807 nat_t *nat;
808 ipfr_t *ipf;
809
810 if ((softf->ipfr_lock) || !softf->ipfr_natlist)
811 return NULL;
812 #ifdef USE_MUTEXES
813 ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_nattab,
814 &softf->ipfr_natfrag);
815 #else
816 ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_nattab);
817 #endif
818 if (ipf != NULL) {
819 nat = ipf->ipfr_data;
820 /*
821 * This is the last fragment for this packet.
822 */
823 if ((ipf->ipfr_ttl == softc->ipf_ticks + 1) && (nat != NULL)) {
824 nat->nat_data = NULL;
825 ipf->ipfr_data = NULL;
826 }
827 RWLOCK_EXIT(&softf->ipfr_natfrag);
828 } else
829 nat = NULL;
830 return nat;
831 }
832
833
834 /* ------------------------------------------------------------------------ */
835 /* Function: ipf_frag_ipidknown */
836 /* Returns: u_32_t - IPv4 ID for this packet if match found, else */
837 /* return 0xfffffff to indicate no match. */
838 /* Parameters: fin(I) - pointer to packet information */
839 /* */
840 /* Functional interface for IP ID lookups of the IP ID fragment cache */
841 /* ------------------------------------------------------------------------ */
842 u_32_t
ipf_frag_ipidknown(fin)843 ipf_frag_ipidknown(fin)
844 fr_info_t *fin;
845 {
846 ipf_main_softc_t *softc = fin->fin_main_soft;
847 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
848 ipfr_t *ipf;
849 u_32_t id;
850
851 if (softf->ipfr_lock || !softf->ipfr_ipidlist)
852 return 0xffffffff;
853
854 #ifdef USE_MUTEXES
855 ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_ipidtab,
856 &softf->ipfr_ipidfrag);
857 #else
858 ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_ipidtab);
859 #endif
860 if (ipf != NULL) {
861 id = (u_32_t)(intptr_t)ipf->ipfr_data;
862 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
863 } else
864 id = 0xffffffff;
865 return id;
866 }
867
868
869 /* ------------------------------------------------------------------------ */
870 /* Function: ipf_frag_known */
871 /* Returns: frentry_t* - pointer to filter rule if a match is found in */
872 /* the frag cache table, else NULL. */
873 /* Parameters: fin(I) - pointer to packet information */
874 /* passp(O) - pointer to where to store rule flags resturned */
875 /* */
876 /* Functional interface for normal lookups of the fragment cache. If a */
877 /* match is found, return the rule pointer and flags from the rule, except */
878 /* that if FR_LOGFIRST is set, reset FR_LOG. */
879 /* ------------------------------------------------------------------------ */
880 frentry_t *
ipf_frag_known(fin,passp)881 ipf_frag_known(fin, passp)
882 fr_info_t *fin;
883 u_32_t *passp;
884 {
885 ipf_main_softc_t *softc = fin->fin_main_soft;
886 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
887 frentry_t *fr = NULL;
888 ipfr_t *fra;
889 u_32_t pass;
890
891 if ((softf->ipfr_lock) || (softf->ipfr_list == NULL))
892 return NULL;
893
894 #ifdef USE_MUTEXES
895 fra = ipf_frag_lookup(softc, softf, fin, softf->ipfr_heads,
896 &softc->ipf_frag);
897 #else
898 fra = ipf_frag_lookup(softc, softf, fin, softf->ipfr_heads);
899 #endif
900 if (fra != NULL) {
901 if (fin->fin_flx & FI_BAD) {
902 fr = &ipfr_block;
903 fin->fin_reason = FRB_BADFRAG;
904 } else {
905 fr = fra->ipfr_rule;
906 }
907 fin->fin_fr = fr;
908 if (fr != NULL) {
909 pass = fr->fr_flags;
910 if ((pass & FR_KEEPSTATE) != 0) {
911 fin->fin_flx |= FI_STATE;
912 /*
913 * Reset the keep state flag here so that we
914 * don't try and add a new state entry because
915 * of a match here. That leads to blocking of
916 * the packet later because the add fails.
917 */
918 pass &= ~FR_KEEPSTATE;
919 }
920 if ((pass & FR_LOGFIRST) != 0)
921 pass &= ~(FR_LOGFIRST|FR_LOG);
922 *passp = pass;
923 }
924 RWLOCK_EXIT(&softc->ipf_frag);
925 }
926 return fr;
927 }
928
929
930 /* ------------------------------------------------------------------------ */
931 /* Function: ipf_frag_natforget */
932 /* Returns: Nil */
933 /* Parameters: softc(I) - pointer to soft context main structure */
934 /* ptr(I) - pointer to data structure */
935 /* */
936 /* Search through all of the fragment cache entries for NAT and wherever a */
937 /* pointer is found to match ptr, reset it to NULL. */
938 /* ------------------------------------------------------------------------ */
939 void
ipf_frag_natforget(softc,ptr)940 ipf_frag_natforget(softc, ptr)
941 ipf_main_softc_t *softc;
942 void *ptr;
943 {
944 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
945 ipfr_t *fr;
946
947 WRITE_ENTER(&softf->ipfr_natfrag);
948 for (fr = softf->ipfr_natlist; fr; fr = fr->ipfr_next)
949 if (fr->ipfr_data == ptr)
950 fr->ipfr_data = NULL;
951 RWLOCK_EXIT(&softf->ipfr_natfrag);
952 }
953
954
955 /* ------------------------------------------------------------------------ */
956 /* Function: ipf_frag_delete */
957 /* Returns: Nil */
958 /* Parameters: softc(I) - pointer to soft context main structure */
959 /* fra(I) - pointer to fragment structure to delete */
960 /* tail(IO) - pointer to the pointer to the tail of the frag */
961 /* list */
962 /* */
963 /* Remove a fragment cache table entry from the table & list. Also free */
964 /* the filter rule it is associated with it if it is no longer used as a */
965 /* result of decreasing the reference count. */
966 /* ------------------------------------------------------------------------ */
967 static void
ipf_frag_delete(softc,fra,tail)968 ipf_frag_delete(softc, fra, tail)
969 ipf_main_softc_t *softc;
970 ipfr_t *fra, ***tail;
971 {
972 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
973
974 if (fra->ipfr_next)
975 fra->ipfr_next->ipfr_prev = fra->ipfr_prev;
976 *fra->ipfr_prev = fra->ipfr_next;
977 if (*tail == &fra->ipfr_next)
978 *tail = fra->ipfr_prev;
979
980 if (fra->ipfr_hnext)
981 fra->ipfr_hnext->ipfr_hprev = fra->ipfr_hprev;
982 *fra->ipfr_hprev = fra->ipfr_hnext;
983
984 if (fra->ipfr_rule != NULL) {
985 (void) ipf_derefrule(softc, &fra->ipfr_rule);
986 }
987
988 if (fra->ipfr_ref <= 0)
989 ipf_frag_free(softf, fra);
990 }
991
992
993 /* ------------------------------------------------------------------------ */
994 /* Function: ipf_frag_free */
995 /* Returns: Nil */
996 /* Parameters: softf(I) - pointer to fragment context information */
997 /* fra(I) - pointer to fragment structure to free */
998 /* */
999 /* Free up a fragment cache entry and bump relevent statistics. */
1000 /* ------------------------------------------------------------------------ */
1001 static void
ipf_frag_free(softf,fra)1002 ipf_frag_free(softf, fra)
1003 ipf_frag_softc_t *softf;
1004 ipfr_t *fra;
1005 {
1006 KFREE(fra);
1007 FBUMP(ifs_expire);
1008 softf->ipfr_stats.ifs_inuse--;
1009 }
1010
1011
1012 /* ------------------------------------------------------------------------ */
1013 /* Function: ipf_frag_clear */
1014 /* Returns: Nil */
1015 /* Parameters: softc(I) - pointer to soft context main structure */
1016 /* */
1017 /* Free memory in use by fragment state information kept. Do the normal */
1018 /* fragment state stuff first and then the NAT-fragment table. */
1019 /* ------------------------------------------------------------------------ */
1020 void
ipf_frag_clear(softc)1021 ipf_frag_clear(softc)
1022 ipf_main_softc_t *softc;
1023 {
1024 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1025 ipfr_t *fra;
1026 nat_t *nat;
1027
1028 WRITE_ENTER(&softc->ipf_frag);
1029 while ((fra = softf->ipfr_list) != NULL) {
1030 fra->ipfr_ref--;
1031 ipf_frag_delete(softc, fra, &softf->ipfr_tail);
1032 }
1033 softf->ipfr_tail = &softf->ipfr_list;
1034 RWLOCK_EXIT(&softc->ipf_frag);
1035
1036 WRITE_ENTER(&softc->ipf_nat);
1037 WRITE_ENTER(&softf->ipfr_natfrag);
1038 while ((fra = softf->ipfr_natlist) != NULL) {
1039 nat = fra->ipfr_data;
1040 if (nat != NULL) {
1041 if (nat->nat_data == fra)
1042 nat->nat_data = NULL;
1043 }
1044 fra->ipfr_ref--;
1045 ipf_frag_delete(softc, fra, &softf->ipfr_nattail);
1046 }
1047 softf->ipfr_nattail = &softf->ipfr_natlist;
1048 RWLOCK_EXIT(&softf->ipfr_natfrag);
1049 RWLOCK_EXIT(&softc->ipf_nat);
1050 }
1051
1052
1053 /* ------------------------------------------------------------------------ */
1054 /* Function: ipf_frag_expire */
1055 /* Returns: Nil */
1056 /* Parameters: softc(I) - pointer to soft context main structure */
1057 /* */
1058 /* Expire entries in the fragment cache table that have been there too long */
1059 /* ------------------------------------------------------------------------ */
1060 void
ipf_frag_expire(softc)1061 ipf_frag_expire(softc)
1062 ipf_main_softc_t *softc;
1063 {
1064 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1065 ipfr_t **fp, *fra;
1066 nat_t *nat;
1067 SPL_INT(s);
1068
1069 if (softf->ipfr_lock)
1070 return;
1071
1072 SPL_NET(s);
1073 WRITE_ENTER(&softc->ipf_frag);
1074 /*
1075 * Go through the entire table, looking for entries to expire,
1076 * which is indicated by the ttl being less than or equal to ipf_ticks.
1077 */
1078 for (fp = &softf->ipfr_list; ((fra = *fp) != NULL); ) {
1079 if (fra->ipfr_ttl > softc->ipf_ticks)
1080 break;
1081 fra->ipfr_ref--;
1082 ipf_frag_delete(softc, fra, &softf->ipfr_tail);
1083 }
1084 RWLOCK_EXIT(&softc->ipf_frag);
1085
1086 WRITE_ENTER(&softf->ipfr_ipidfrag);
1087 for (fp = &softf->ipfr_ipidlist; ((fra = *fp) != NULL); ) {
1088 if (fra->ipfr_ttl > softc->ipf_ticks)
1089 break;
1090 fra->ipfr_ref--;
1091 ipf_frag_delete(softc, fra, &softf->ipfr_ipidtail);
1092 }
1093 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
1094
1095 /*
1096 * Same again for the NAT table, except that if the structure also
1097 * still points to a NAT structure, and the NAT structure points back
1098 * at the one to be free'd, NULL the reference from the NAT struct.
1099 * NOTE: We need to grab both mutex's early, and in this order so as
1100 * to prevent a deadlock if both try to expire at the same time.
1101 * The extra if() statement here is because it locks out all NAT
1102 * operations - no need to do that if there are no entries in this
1103 * list, right?
1104 */
1105 if (softf->ipfr_natlist != NULL) {
1106 WRITE_ENTER(&softc->ipf_nat);
1107 WRITE_ENTER(&softf->ipfr_natfrag);
1108 for (fp = &softf->ipfr_natlist; ((fra = *fp) != NULL); ) {
1109 if (fra->ipfr_ttl > softc->ipf_ticks)
1110 break;
1111 nat = fra->ipfr_data;
1112 if (nat != NULL) {
1113 if (nat->nat_data == fra)
1114 nat->nat_data = NULL;
1115 }
1116 fra->ipfr_ref--;
1117 ipf_frag_delete(softc, fra, &softf->ipfr_nattail);
1118 }
1119 RWLOCK_EXIT(&softf->ipfr_natfrag);
1120 RWLOCK_EXIT(&softc->ipf_nat);
1121 }
1122 SPL_X(s);
1123 }
1124
1125
1126 /* ------------------------------------------------------------------------ */
1127 /* Function: ipf_frag_pkt_next */
1128 /* Returns: int - 0 == success, else error */
1129 /* Parameters: softc(I) - pointer to soft context main structure */
1130 /* token(I) - pointer to token information for this caller */
1131 /* itp(I) - pointer to generic iterator from caller */
1132 /* */
1133 /* This function is used to step through the fragment cache list used for */
1134 /* filter rules. The hard work is done by the more generic ipf_frag_next. */
1135 /* ------------------------------------------------------------------------ */
1136 int
ipf_frag_pkt_next(softc,token,itp)1137 ipf_frag_pkt_next(softc, token, itp)
1138 ipf_main_softc_t *softc;
1139 ipftoken_t *token;
1140 ipfgeniter_t *itp;
1141 {
1142 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1143
1144 #ifdef USE_MUTEXES
1145 return ipf_frag_next(softc, token, itp, &softf->ipfr_list,
1146 &softf->ipfr_frag);
1147 #else
1148 return ipf_frag_next(softc, token, itp, &softf->ipfr_list);
1149 #endif
1150 }
1151
1152
1153 /* ------------------------------------------------------------------------ */
1154 /* Function: ipf_frag_nat_next */
1155 /* Returns: int - 0 == success, else error */
1156 /* Parameters: softc(I) - pointer to soft context main structure */
1157 /* token(I) - pointer to token information for this caller */
1158 /* itp(I) - pointer to generic iterator from caller */
1159 /* */
1160 /* This function is used to step through the fragment cache list used for */
1161 /* NAT. The hard work is done by the more generic ipf_frag_next. */
1162 /* ------------------------------------------------------------------------ */
1163 int
ipf_frag_nat_next(softc,token,itp)1164 ipf_frag_nat_next(softc, token, itp)
1165 ipf_main_softc_t *softc;
1166 ipftoken_t *token;
1167 ipfgeniter_t *itp;
1168 {
1169 ipf_frag_softc_t *softf = softc->ipf_frag_soft;;
1170
1171 #ifdef USE_MUTEXES
1172 return ipf_frag_next(softc, token, itp, &softf->ipfr_natlist,
1173 &softf->ipfr_natfrag);
1174 #else
1175 return ipf_frag_next(softc, token, itp, &softf->ipfr_natlist);
1176 #endif
1177 }
1178
1179 /* ------------------------------------------------------------------------ */
1180 /* Function: ipf_frag_next */
1181 /* Returns: int - 0 == success, else error */
1182 /* Parameters: softc(I) - pointer to soft context main structure */
1183 /* token(I) - pointer to token information for this caller */
1184 /* itp(I) - pointer to generic iterator from caller */
1185 /* top(I) - top of the fragment list */
1186 /* lock(I) - fragment cache lock */
1187 /* */
1188 /* This function is used to interate through the list of entries in the */
1189 /* fragment cache. It increases the reference count on the one currently */
1190 /* being returned so that the caller can come back and resume from it later.*/
1191 /* */
1192 /* This function is used for both the NAT fragment cache as well as the ipf */
1193 /* fragment cache - hence the reason for passing in top and lock. */
1194 /* ------------------------------------------------------------------------ */
1195 static int
ipf_frag_next(softc,token,itp,top,lock)1196 ipf_frag_next(softc, token, itp, top
1197 #ifdef USE_MUTEXES
1198 , lock
1199 #endif
1200 )
1201 ipf_main_softc_t *softc;
1202 ipftoken_t *token;
1203 ipfgeniter_t *itp;
1204 ipfr_t **top;
1205 #ifdef USE_MUTEXES
1206 ipfrwlock_t *lock;
1207 #endif
1208 {
1209 ipfr_t *frag, *next, zero;
1210 int error = 0;
1211
1212 if (itp->igi_data == NULL) {
1213 IPFERROR(20001);
1214 return EFAULT;
1215 }
1216
1217 if (itp->igi_nitems != 1) {
1218 IPFERROR(20003);
1219 return EFAULT;
1220 }
1221
1222 frag = token->ipt_data;
1223
1224 READ_ENTER(lock);
1225
1226 if (frag == NULL)
1227 next = *top;
1228 else
1229 next = frag->ipfr_next;
1230
1231 if (next != NULL) {
1232 ATOMIC_INC(next->ipfr_ref);
1233 token->ipt_data = next;
1234 } else {
1235 bzero(&zero, sizeof(zero));
1236 next = &zero;
1237 token->ipt_data = NULL;
1238 }
1239 if (next->ipfr_next == NULL)
1240 ipf_token_mark_complete(token);
1241
1242 RWLOCK_EXIT(lock);
1243
1244 error = COPYOUT(next, itp->igi_data, sizeof(*next));
1245 if (error != 0)
1246 IPFERROR(20002);
1247
1248 if (frag != NULL) {
1249 #ifdef USE_MUTEXES
1250 ipf_frag_deref(softc, &frag, lock);
1251 #else
1252 ipf_frag_deref(softc, &frag);
1253 #endif
1254 }
1255 return error;
1256 }
1257
1258
1259 /* ------------------------------------------------------------------------ */
1260 /* Function: ipf_frag_pkt_deref */
1261 /* Returns: Nil */
1262 /* Parameters: softc(I) - pointer to soft context main structure */
1263 /* data(I) - pointer to frag cache pointer */
1264 /* */
1265 /* This function is the external interface for dropping a reference to a */
1266 /* fragment cache entry used by filter rules. */
1267 /* ------------------------------------------------------------------------ */
1268 void
ipf_frag_pkt_deref(softc,data)1269 ipf_frag_pkt_deref(softc, data)
1270 ipf_main_softc_t *softc;
1271 void *data;
1272 {
1273 ipfr_t **frp = data;
1274
1275 #ifdef USE_MUTEXES
1276 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1277
1278 ipf_frag_deref(softc->ipf_frag_soft, frp, &softf->ipfr_frag);
1279 #else
1280 ipf_frag_deref(softc->ipf_frag_soft, frp);
1281 #endif
1282 }
1283
1284
1285 /* ------------------------------------------------------------------------ */
1286 /* Function: ipf_frag_nat_deref */
1287 /* Returns: Nil */
1288 /* Parameters: softc(I) - pointer to soft context main structure */
1289 /* data(I) - pointer to frag cache pointer */
1290 /* */
1291 /* This function is the external interface for dropping a reference to a */
1292 /* fragment cache entry used by NAT table entries. */
1293 /* ------------------------------------------------------------------------ */
1294 void
ipf_frag_nat_deref(softc,data)1295 ipf_frag_nat_deref(softc, data)
1296 ipf_main_softc_t *softc;
1297 void *data;
1298 {
1299 ipfr_t **frp = data;
1300
1301 #ifdef USE_MUTEXES
1302 ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1303
1304 ipf_frag_deref(softc->ipf_frag_soft, frp, &softf->ipfr_natfrag);
1305 #else
1306 ipf_frag_deref(softc->ipf_frag_soft, frp);
1307 #endif
1308 }
1309
1310
1311 /* ------------------------------------------------------------------------ */
1312 /* Function: ipf_frag_deref */
1313 /* Returns: Nil */
1314 /* Parameters: frp(IO) - pointer to fragment structure to deference */
1315 /* lock(I) - lock associated with the fragment */
1316 /* */
1317 /* This function dereferences a fragment structure (ipfr_t). The pointer */
1318 /* passed in will always be reset back to NULL, even if the structure is */
1319 /* not freed, to enforce the notion that the caller is no longer entitled */
1320 /* to use the pointer it is dropping the reference to. */
1321 /* ------------------------------------------------------------------------ */
1322 static void
ipf_frag_deref(arg,frp,lock)1323 ipf_frag_deref(arg, frp
1324 #ifdef USE_MUTEXES
1325 , lock
1326 #endif
1327 )
1328 void *arg;
1329 ipfr_t **frp;
1330 #ifdef USE_MUTEXES
1331 ipfrwlock_t *lock;
1332 #endif
1333 {
1334 ipf_frag_softc_t *softf = arg;
1335 ipfr_t *fra;
1336
1337 fra = *frp;
1338 *frp = NULL;
1339
1340 WRITE_ENTER(lock);
1341 fra->ipfr_ref--;
1342 if (fra->ipfr_ref <= 0)
1343 ipf_frag_free(softf, fra);
1344 RWLOCK_EXIT(lock);
1345 }
1346