sys/contrib/ipfilter/netinet/ip_frag.c

   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 #if !defined(_KERNEL)
  20 # include <stdio.h>
  21 # include <string.h>
  22 # include <stdlib.h>
  23 # define _KERNEL
  24 # include <sys/uio.h>
  25 # undef _KERNEL
  26 #endif
  27 #if defined(_KERNEL) && defined(__FreeBSD_version)
  28 # include <sys/filio.h>
  29 # include <sys/fcntl.h>
  30 #else
  31 # include <sys/ioctl.h>
  32 #endif
  33 # include <sys/protosw.h>
  34 #include <sys/socket.h>
  35 #if defined(_KERNEL)
  36 # include <sys/systm.h>
  37 # if !defined(__SVR4)
  38 #  include <sys/mbuf.h>
  39 # endif
  40 #endif
  41 #if !defined(__SVR4)
  42 # if defined(_KERNEL)
  43 #  include <sys/kernel.h>
  44 # endif
  45 #else
  46 # include <sys/byteorder.h>
  47 # ifdef _KERNEL
  48 #  include <sys/dditypes.h>
  49 # endif
  50 # include <sys/stream.h>
  51 # include <sys/kmem.h>
  52 #endif
  53 #include <net/if.h>
  54 #ifdef sun
  55 # include <net/af.h>
  56 #endif
  57 #include <netinet/in.h>
  58 #include <netinet/in_systm.h>
  59 #include <netinet/ip.h>
  60 # include <netinet/ip_var.h>
  61 #include <netinet/tcp.h>
  62 #include <netinet/udp.h>
  63 #include <netinet/ip_icmp.h>
  64 #include "netinet/ip_compat.h"
  65 #include <netinet/tcpip.h>
  66 #include "netinet/ip_fil.h"
  67 #include "netinet/ip_nat.h"
  68 #include "netinet/ip_frag.h"
  69 #include "netinet/ip_state.h"
  70 #include "netinet/ip_auth.h"
  71 #include "netinet/ip_lookup.h"
  72 #include "netinet/ip_proxy.h"
  73 #include "netinet/ip_sync.h"
  74 /* END OF INCLUDES */
  75
  76 #if !defined(lint)
  77 static const char sccsid[] = "@(#)ip_frag.c     1.11 3/24/96 (C) 1993-2000 Darren Reed";
  78 static const char rcsid[] = "@(#)$FreeBSD$";
  79 /* static const char rcsid[] = "@(#)$Id: ip_frag.c,v 2.77.2.12 2007/09/20 12:51:51 darrenr Exp $"; */
  80 #endif
  81
  82
  83 #ifdef USE_MUTEXES
  84 static ipfr_t *ipfr_frag_new __P((ipf_main_softc_t *, ipf_frag_softc_t *,
  85                                   fr_info_t *, u_32_t, ipfr_t **,
  86                                   ipfrwlock_t *));
  87 static ipfr_t *ipf_frag_lookup __P((ipf_main_softc_t *, ipf_frag_softc_t *, fr_info_t *, ipfr_t **, ipfrwlock_t *));
  88 static void ipf_frag_deref __P((void *, ipfr_t **, ipfrwlock_t *));
  89 static int ipf_frag_next __P((ipf_main_softc_t *, ipftoken_t *, ipfgeniter_t *,
  90                               ipfr_t **, ipfrwlock_t *));
  91 #else
  92 static ipfr_t *ipfr_frag_new __P((ipf_main_softc_t *, ipf_frag_softc_t *,
  93                                   fr_info_t *, u_32_t, ipfr_t **));
  94 static ipfr_t *ipf_frag_lookup __P((ipf_main_softc_t *, ipf_frag_softc_t *, fr_info_t *, ipfr_t **));
  95 static void ipf_frag_deref __P((void *, ipfr_t **));
  96 static int ipf_frag_next __P((ipf_main_softc_t *, ipftoken_t *, ipfgeniter_t *,
  97                               ipfr_t **));
  98 #endif
  99 static void ipf_frag_delete __P((ipf_main_softc_t *, ipfr_t *, ipfr_t ***));
 100 static void ipf_frag_free __P((ipf_frag_softc_t *, ipfr_t *));
 101
 102 static frentry_t ipfr_block;
 103
 104 static ipftuneable_t ipf_frag_tuneables[] = {
 105         { { (void *)offsetof(ipf_frag_softc_t, ipfr_size) },
 106                 "frag_size",            1,      0x7fffffff,
 107                 stsizeof(ipf_frag_softc_t, ipfr_size),
 108                 IPFT_WRDISABLED,        NULL,   NULL },
 109         { { (void *)offsetof(ipf_frag_softc_t, ipfr_ttl) },
 110                 "frag_ttl",             1,      0x7fffffff,
 111                 stsizeof(ipf_frag_softc_t, ipfr_ttl),
 112                 0,                      NULL,   NULL },
 113         { { NULL },
 114                 NULL,                   0,      0,
 115                 0,
 116                 0,                      NULL,   NULL }
 117 };
 118
 119 #define FBUMP(x)        softf->ipfr_stats.x++
 120 #define FBUMPD(x)       do { softf->ipfr_stats.x++; DT(x); } while (0)
 121
 122
 123 /* ------------------------------------------------------------------------ */
 124 /* Function:    ipf_frag_main_load                                          */
 125 /* Returns:     int - 0 == success, -1 == error                             */
 126 /* Parameters:  Nil                                                         */
 127 /*                                                                          */
 128 /* Initialise the filter rule associted with blocked packets - everyone can */
 129 /* use it.                                                                  */
 130 /* ------------------------------------------------------------------------ */
 131 int
 132 ipf_frag_main_load()
 133 {
 134         bzero((char *)&ipfr_block, sizeof(ipfr_block));
 135         ipfr_block.fr_flags = FR_BLOCK|FR_QUICK;
 136         ipfr_block.fr_ref = 1;
 137
 138         return 0;
 139 }
 140
 141
 142 /* ------------------------------------------------------------------------ */
 143 /* Function:    ipf_frag_main_unload                                        */
 144 /* Returns:     int - 0 == success, -1 == error                             */
 145 /* Parameters:  Nil                                                         */
 146 /*                                                                          */
 147 /* A null-op function that exists as a placeholder so that the flow in      */
 148 /* other functions is obvious.                                              */
 149 /* ------------------------------------------------------------------------ */
 150 int
 151 ipf_frag_main_unload()
 152 {
 153         return 0;
 154 }
 155
 156
 157 /* ------------------------------------------------------------------------ */
 158 /* Function:    ipf_frag_soft_create                                        */
 159 /* Returns:     void *   - NULL = failure, else pointer to local context    */
 160 /* Parameters:  softc(I) - pointer to soft context main structure           */
 161 /*                                                                          */
 162 /* Allocate a new soft context structure to track fragment related info.    */
 163 /* ------------------------------------------------------------------------ */
 164 /*ARGSUSED*/
 165 void *
 166 ipf_frag_soft_create(softc)
 167         ipf_main_softc_t *softc;
 168 {
 169         ipf_frag_softc_t *softf;
 170
 171         KMALLOC(softf, ipf_frag_softc_t *);
 172         if (softf == NULL)
 173                 return NULL;
 174
 175         bzero((char *)softf, sizeof(*softf));
 176
 177         RWLOCK_INIT(&softf->ipfr_ipidfrag, "frag ipid lock");
 178         RWLOCK_INIT(&softf->ipfr_frag, "ipf fragment rwlock");
 179         RWLOCK_INIT(&softf->ipfr_natfrag, "ipf NAT fragment rwlock");
 180
 181         softf->ipf_frag_tune = ipf_tune_array_copy(softf,
 182                                                    sizeof(ipf_frag_tuneables),
 183                                                    ipf_frag_tuneables);
 184         if (softf->ipf_frag_tune == NULL) {
 185                 ipf_frag_soft_destroy(softc, softf);
 186                 return NULL;
 187         }
 188         if (ipf_tune_array_link(softc, softf->ipf_frag_tune) == -1) {
 189                 ipf_frag_soft_destroy(softc, softf);
 190                 return NULL;
 191         }
 192
 193         softf->ipfr_size = IPFT_SIZE;
 194         softf->ipfr_ttl = IPF_TTLVAL(60);
 195         softf->ipfr_lock = 1;
 196         softf->ipfr_tail = &softf->ipfr_list;
 197         softf->ipfr_nattail = &softf->ipfr_natlist;
 198         softf->ipfr_ipidtail = &softf->ipfr_ipidlist;
 199
 200         return softf;
 201 }
 202
 203
 204 /* ------------------------------------------------------------------------ */
 205 /* Function:    ipf_frag_soft_destroy                                       */
 206 /* Returns:     Nil                                                         */
 207 /* Parameters:  softc(I) - pointer to soft context main structure           */
 208 /*              arg(I)   - pointer to local context to use                  */
 209 /*                                                                          */
 210 /* Initialise the hash tables for the fragment cache lookups.               */
 211 /* ------------------------------------------------------------------------ */
 212 void
 213 ipf_frag_soft_destroy(softc, arg)
 214         ipf_main_softc_t *softc;
 215         void *arg;
 216 {
 217         ipf_frag_softc_t *softf = arg;
 218
 219         RW_DESTROY(&softf->ipfr_ipidfrag);
 220         RW_DESTROY(&softf->ipfr_frag);
 221         RW_DESTROY(&softf->ipfr_natfrag);
 222
 223         if (softf->ipf_frag_tune != NULL) {
 224                 ipf_tune_array_unlink(softc, softf->ipf_frag_tune);
 225                 KFREES(softf->ipf_frag_tune, sizeof(ipf_frag_tuneables));
 226                 softf->ipf_frag_tune = NULL;
 227         }
 228
 229         KFREE(softf);
 230 }
 231
 232
 233 /* ------------------------------------------------------------------------ */
 234 /* Function:    ipf_frag_soft_init                                          */
 235 /* Returns:     int      - 0 == success, -1 == error                        */
 236 /* Parameters:  softc(I) - pointer to soft context main structure           */
 237 /*              arg(I)   - pointer to local context to use                  */
 238 /*                                                                          */
 239 /* Initialise the hash tables for the fragment cache lookups.               */
 240 /* ------------------------------------------------------------------------ */
 241 /*ARGSUSED*/
 242 int
 243 ipf_frag_soft_init(softc, arg)
 244         ipf_main_softc_t *softc;
 245         void *arg;
 246 {
 247         ipf_frag_softc_t *softf = arg;
 248
 249         KMALLOCS(softf->ipfr_heads, ipfr_t **,
 250                  softf->ipfr_size * sizeof(ipfr_t *));
 251         if (softf->ipfr_heads == NULL)
 252                 return -1;
 253
 254         bzero((char *)softf->ipfr_heads, softf->ipfr_size * sizeof(ipfr_t *));
 255
 256         KMALLOCS(softf->ipfr_nattab, ipfr_t **,
 257                  softf->ipfr_size * sizeof(ipfr_t *));
 258         if (softf->ipfr_nattab == NULL)
 259                 return -2;
 260
 261         bzero((char *)softf->ipfr_nattab, softf->ipfr_size * sizeof(ipfr_t *));
 262
 263         KMALLOCS(softf->ipfr_ipidtab, ipfr_t **,
 264                  softf->ipfr_size * sizeof(ipfr_t *));
 265         if (softf->ipfr_ipidtab == NULL)
 266                 return -3;
 267
 268         bzero((char *)softf->ipfr_ipidtab,
 269               softf->ipfr_size * sizeof(ipfr_t *));
 270
 271         softf->ipfr_lock = 0;
 272         softf->ipfr_inited = 1;
 273
 274         return 0;
 275 }
 276
 277
 278 /* ------------------------------------------------------------------------ */
 279 /* Function:    ipf_frag_soft_fini                                          */
 280 /* Returns:     int      - 0 == success, -1 == error                        */
 281 /* Parameters:  softc(I) - pointer to soft context main structure           */
 282 /*              arg(I)   - pointer to local context to use                  */
 283 /*                                                                          */
 284 /* Free all memory allocated whilst running and from initialisation.        */
 285 /* ------------------------------------------------------------------------ */
 286 int
 287 ipf_frag_soft_fini(softc, arg)
 288         ipf_main_softc_t *softc;
 289         void *arg;
 290 {
 291         ipf_frag_softc_t *softf = arg;
 292
 293         softf->ipfr_lock = 1;
 294
 295         if (softf->ipfr_inited == 1) {
 296                 ipf_frag_clear(softc);
 297
 298                 softf->ipfr_inited = 0;
 299         }
 300
 301         if (softf->ipfr_heads != NULL)
 302                 KFREES(softf->ipfr_heads,
 303                        softf->ipfr_size * sizeof(ipfr_t *));
 304         softf->ipfr_heads = NULL;
 305
 306         if (softf->ipfr_nattab != NULL)
 307                 KFREES(softf->ipfr_nattab,
 308                        softf->ipfr_size * sizeof(ipfr_t *));
 309         softf->ipfr_nattab = NULL;
 310
 311         if (softf->ipfr_ipidtab != NULL)
 312                 KFREES(softf->ipfr_ipidtab,
 313                        softf->ipfr_size * sizeof(ipfr_t *));
 314         softf->ipfr_ipidtab = NULL;
 315
 316         return 0;
 317 }
 318
 319
 320 /* ------------------------------------------------------------------------ */
 321 /* Function:    ipf_frag_set_lock                                           */
 322 /* Returns:     Nil                                                         */
 323 /* Parameters:  arg(I) - pointer to local context to use                    */
 324 /*              tmp(I) - new value for lock                                 */
 325 /*                                                                          */
 326 /* Stub function that allows for external manipulation of ipfr_lock         */
 327 /* ------------------------------------------------------------------------ */
 328 void
 329 ipf_frag_setlock(arg, tmp)
 330         void *arg;
 331         int tmp;
 332 {
 333         ipf_frag_softc_t *softf = arg;
 334
 335         softf->ipfr_lock = tmp;
 336 }
 337
 338
 339 /* ------------------------------------------------------------------------ */
 340 /* Function:    ipf_frag_stats                                              */
 341 /* Returns:     ipfrstat_t* - pointer to struct with current frag stats     */
 342 /* Parameters:  arg(I) - pointer to local context to use                    */
 343 /*                                                                          */
 344 /* Updates ipfr_stats with current information and returns a pointer to it  */
 345 /* ------------------------------------------------------------------------ */
 346 ipfrstat_t *
 347 ipf_frag_stats(arg)
 348         void *arg;
 349 {
 350         ipf_frag_softc_t *softf = arg;
 351
 352         softf->ipfr_stats.ifs_table = softf->ipfr_heads;
 353         softf->ipfr_stats.ifs_nattab = softf->ipfr_nattab;
 354         return &softf->ipfr_stats;
 355 }
 356
 357
 358 /* ------------------------------------------------------------------------ */
 359 /* Function:    ipfr_frag_new                                               */
 360 /* Returns:     ipfr_t * - pointer to fragment cache state info or NULL     */
 361 /* Parameters:  fin(I)   - pointer to packet information                    */
 362 /*              table(I) - pointer to frag table to add to                  */
 363 /*              lock(I)  - pointer to lock to get a write hold of           */
 364 /*                                                                          */
 365 /* Add a new entry to the fragment cache, registering it as having come     */
 366 /* through this box, with the result of the filter operation.               */
 367 /*                                                                          */
 368 /* If this function succeeds, it returns with a write lock held on "lock".  */
 369 /* If it fails, no lock is held on return.                                  */
 370 /* ------------------------------------------------------------------------ */
 371 static ipfr_t *
 372 ipfr_frag_new(softc, softf, fin, pass, table
 373 #ifdef USE_MUTEXES
 374 , lock
 375 #endif
 376 )
 377         ipf_main_softc_t *softc;
 378         ipf_frag_softc_t *softf;
 379         fr_info_t *fin;
 380         u_32_t pass;
 381         ipfr_t *table[];
 382 #ifdef USE_MUTEXES
 383         ipfrwlock_t *lock;
 384 #endif
 385 {
 386         ipfr_t *fra, frag, *fran;
 387         u_int idx, off;
 388         frentry_t *fr;
 389
 390         if (softf->ipfr_stats.ifs_inuse >= softf->ipfr_size) {
 391                 FBUMPD(ifs_maximum);
 392                 return NULL;
 393         }
 394
 395         if ((fin->fin_flx & (FI_FRAG|FI_BAD)) != FI_FRAG) {
 396                 FBUMPD(ifs_newbad);
 397                 return NULL;
 398         }
 399
 400         if (pass & FR_FRSTRICT) {
 401                 if (fin->fin_off != 0) {
 402                         FBUMPD(ifs_newrestrictnot0);
 403                         return NULL;
 404                 }
 405         }
 406
 407         memset(&frag, 0, sizeof(frag));
 408         frag.ipfr_v = fin->fin_v;
 409         idx = fin->fin_v;
 410         frag.ipfr_p = fin->fin_p;
 411         idx += fin->fin_p;
 412         frag.ipfr_id = fin->fin_id;
 413         idx += fin->fin_id;
 414         frag.ipfr_source = fin->fin_fi.fi_src;
 415         idx += frag.ipfr_src.s_addr;
 416         frag.ipfr_dest = fin->fin_fi.fi_dst;
 417         idx += frag.ipfr_dst.s_addr;
 418         frag.ipfr_ifp = fin->fin_ifp;
 419         idx *= 127;
 420         idx %= softf->ipfr_size;
 421
 422         frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY;
 423         frag.ipfr_secmsk = fin->fin_fi.fi_secmsk;
 424         frag.ipfr_auth = fin->fin_fi.fi_auth;
 425
 426         off = fin->fin_off >> 3;
 427         if (off == 0) {
 428                 char *ptr;
 429                 int end;
 430
 431 #ifdef USE_INET6
 432                 if (fin->fin_v == 6) {
 433
 434                         ptr = (char *)fin->fin_fraghdr +
 435                               sizeof(struct ip6_frag);
 436                 } else
 437 #endif
 438                 {
 439                         ptr = fin->fin_dp;
 440                 }
 441                 end = fin->fin_plen - (ptr - (char *)fin->fin_ip);
 442                 frag.ipfr_firstend = end >> 3;
 443         } else {
 444                 frag.ipfr_firstend = 0;
 445         }
 446
 447         /*
 448          * allocate some memory, if possible, if not, just record that we
 449          * failed to do so.
 450          */
 451         KMALLOC(fran, ipfr_t *);
 452         if (fran == NULL) {
 453                 FBUMPD(ifs_nomem);
 454                 return NULL;
 455         }
 456         memset(fran, 0, sizeof(*fran));
 457
 458         WRITE_ENTER(lock);
 459
 460         /*
 461          * first, make sure it isn't already there...
 462          */
 463         for (fra = table[idx]; (fra != NULL); fra = fra->ipfr_hnext)
 464                 if (!bcmp((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp,
 465                           IPFR_CMPSZ)) {
 466                         RWLOCK_EXIT(lock);
 467                         FBUMPD(ifs_exists);
 468                         KFREE(fran);
 469                         return NULL;
 470                 }
 471
 472         fra = fran;
 473         fran = NULL;
 474         fr = fin->fin_fr;
 475         fra->ipfr_rule = fr;
 476         if (fr != NULL) {
 477                 MUTEX_ENTER(&fr->fr_lock);
 478                 fr->fr_ref++;
 479                 MUTEX_EXIT(&fr->fr_lock);
 480         }
 481
 482         /*
 483          * Insert the fragment into the fragment table, copy the struct used
 484          * in the search using bcopy rather than reassign each field.
 485          * Set the ttl to the default.
 486          */
 487         if ((fra->ipfr_hnext = table[idx]) != NULL)
 488                 table[idx]->ipfr_hprev = &fra->ipfr_hnext;
 489         fra->ipfr_hprev = table + idx;
 490         fra->ipfr_data = NULL;
 491         table[idx] = fra;
 492         bcopy((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, IPFR_CMPSZ);
 493         fra->ipfr_v = fin->fin_v;
 494         fra->ipfr_p = fin->fin_p;
 495         fra->ipfr_ttl = softc->ipf_ticks + softf->ipfr_ttl;
 496         fra->ipfr_firstend = frag.ipfr_firstend;
 497
 498         /*
 499          * Compute the offset of the expected start of the next packet.
 500          */
 501         if (off == 0)
 502                 fra->ipfr_seen0 = 1;
 503         fra->ipfr_off = off + (fin->fin_dlen >> 3);
 504         fra->ipfr_pass = pass;
 505         fra->ipfr_ref = 1;
 506         fra->ipfr_pkts = 1;
 507         fra->ipfr_bytes = fin->fin_plen;
 508         FBUMP(ifs_inuse);
 509         FBUMP(ifs_new);
 510         return fra;
 511 }
 512
 513
 514 /* ------------------------------------------------------------------------ */
 515 /* Function:    ipf_frag_new                                                */
 516 /* Returns:     int - 0 == success, -1 == error                             */
 517 /* Parameters:  fin(I)  - pointer to packet information                     */
 518 /*                                                                          */
 519 /* Add a new entry to the fragment cache table based on the current packet  */
 520 /* ------------------------------------------------------------------------ */
 521 int
 522 ipf_frag_new(softc, fin, pass)
 523         ipf_main_softc_t *softc;
 524         u_32_t pass;
 525         fr_info_t *fin;
 526 {
 527         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 528         ipfr_t  *fra;
 529
 530         if (softf->ipfr_lock != 0)
 531                 return -1;
 532
 533 #ifdef USE_MUTEXES
 534         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_heads, &softc->ipf_frag);
 535 #else
 536         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_heads);
 537 #endif
 538         if (fra != NULL) {
 539                 *softf->ipfr_tail = fra;
 540                 fra->ipfr_prev = softf->ipfr_tail;
 541                 softf->ipfr_tail = &fra->ipfr_next;
 542                 fra->ipfr_next = NULL;
 543                 RWLOCK_EXIT(&softc->ipf_frag);
 544         }
 545         return fra ? 0 : -1;
 546 }
 547
 548
 549 /* ------------------------------------------------------------------------ */
 550 /* Function:    ipf_frag_natnew                                             */
 551 /* Returns:     int - 0 == success, -1 == error                             */
 552 /* Parameters:  fin(I)  - pointer to packet information                     */
 553 /*              nat(I)  - pointer to NAT structure                          */
 554 /*                                                                          */
 555 /* Create a new NAT fragment cache entry based on the current packet and    */
 556 /* the NAT structure for this "session".                                    */
 557 /* ------------------------------------------------------------------------ */
 558 int
 559 ipf_frag_natnew(softc, fin, pass, nat)
 560         ipf_main_softc_t *softc;
 561         fr_info_t *fin;
 562         u_32_t pass;
 563         nat_t *nat;
 564 {
 565         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 566         ipfr_t  *fra;
 567
 568         if (softf->ipfr_lock != 0)
 569                 return 0;
 570
 571 #ifdef USE_MUTEXES
 572         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_nattab,
 573                             &softf->ipfr_natfrag);
 574 #else
 575         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_nattab);
 576 #endif
 577         if (fra != NULL) {
 578                 fra->ipfr_data = nat;
 579                 nat->nat_data = fra;
 580                 *softf->ipfr_nattail = fra;
 581                 fra->ipfr_prev = softf->ipfr_nattail;
 582                 softf->ipfr_nattail = &fra->ipfr_next;
 583                 fra->ipfr_next = NULL;
 584                 RWLOCK_EXIT(&softf->ipfr_natfrag);
 585                 return 0;
 586         }
 587         return -1;
 588 }
 589
 590
 591 /* ------------------------------------------------------------------------ */
 592 /* Function:    ipf_frag_ipidnew                                            */
 593 /* Returns:     int - 0 == success, -1 == error                             */
 594 /* Parameters:  fin(I)  - pointer to packet information                     */
 595 /*              ipid(I) - new IP ID for this fragmented packet              */
 596 /*                                                                          */
 597 /* Create a new fragment cache entry for this packet and store, as a data   */
 598 /* pointer, the new IP ID value.                                            */
 599 /* ------------------------------------------------------------------------ */
 600 int
 601 ipf_frag_ipidnew(fin, ipid)
 602         fr_info_t *fin;
 603         u_32_t ipid;
 604 {
 605         ipf_main_softc_t *softc = fin->fin_main_soft;
 606         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 607         ipfr_t  *fra;
 608
 609         if (softf->ipfr_lock)
 610                 return 0;
 611
 612 #ifdef USE_MUTEXES
 613         fra = ipfr_frag_new(softc, softf, fin, 0, softf->ipfr_ipidtab, &softf->ipfr_ipidfrag);
 614 #else
 615         fra = ipfr_frag_new(softc, softf, fin, 0, softf->ipfr_ipidtab);
 616 #endif
 617         if (fra != NULL) {
 618                 fra->ipfr_data = (void *)(intptr_t)ipid;
 619                 *softf->ipfr_ipidtail = fra;
 620                 fra->ipfr_prev = softf->ipfr_ipidtail;
 621                 softf->ipfr_ipidtail = &fra->ipfr_next;
 622                 fra->ipfr_next = NULL;
 623                 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
 624         }
 625         return fra ? 0 : -1;
 626 }
 627
 628
 629 /* ------------------------------------------------------------------------ */
 630 /* Function:    ipf_frag_lookup                                             */
 631 /* Returns:     ipfr_t * - pointer to ipfr_t structure if there's a         */
 632 /*                         matching entry in the frag table, else NULL      */
 633 /* Parameters:  fin(I)   - pointer to packet information                    */
 634 /*              table(I) - pointer to fragment cache table to search        */
 635 /*                                                                          */
 636 /* Check the fragment cache to see if there is already a record of this     */
 637 /* packet with its filter result known.                                     */
 638 /*                                                                          */
 639 /* If this function succeeds, it returns with a write lock held on "lock".  */
 640 /* If it fails, no lock is held on return.                                  */
 641 /* ------------------------------------------------------------------------ */
 642 static ipfr_t *
 643 ipf_frag_lookup(softc, softf, fin, table
 644 #ifdef USE_MUTEXES
 645 , lock
 646 #endif
 647 )
 648         ipf_main_softc_t *softc;
 649         ipf_frag_softc_t *softf;
 650         fr_info_t *fin;
 651         ipfr_t *table[];
 652 #ifdef USE_MUTEXES
 653         ipfrwlock_t *lock;
 654 #endif
 655 {
 656         ipfr_t *f, frag;
 657         u_int idx;
 658
 659         /*
 660          * We don't want to let short packets match because they could be
 661          * compromising the security of other rules that want to match on
 662          * layer 4 fields (and can't because they have been fragmented off.)
 663          * Why do this check here?  The counter acts as an indicator of this
 664          * kind of attack, whereas if it was elsewhere, it wouldn't know if
 665          * other matching packets had been seen.
 666          */
 667         if (fin->fin_flx & FI_SHORT) {
 668                 FBUMPD(ifs_short);
 669                 return NULL;
 670         }
 671
 672         if ((fin->fin_flx & FI_BAD) != 0) {
 673                 FBUMPD(ifs_bad);
 674                 return NULL;
 675         }
 676
 677         /*
 678          * For fragments, we record protocol, packet id, TOS and both IP#'s
 679          * (these should all be the same for all fragments of a packet).
 680          *
 681          * build up a hash value to index the table with.
 682          */
 683         memset(&frag, 0, sizeof(frag));
 684         frag.ipfr_v = fin->fin_v;
 685         idx = fin->fin_v;
 686         frag.ipfr_p = fin->fin_p;
 687         idx += fin->fin_p;
 688         frag.ipfr_id = fin->fin_id;
 689         idx += fin->fin_id;
 690         frag.ipfr_source = fin->fin_fi.fi_src;
 691         idx += frag.ipfr_src.s_addr;
 692         frag.ipfr_dest = fin->fin_fi.fi_dst;
 693         idx += frag.ipfr_dst.s_addr;
 694         frag.ipfr_ifp = fin->fin_ifp;
 695         idx *= 127;
 696         idx %= softf->ipfr_size;
 697
 698         frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY;
 699         frag.ipfr_secmsk = fin->fin_fi.fi_secmsk;
 700         frag.ipfr_auth = fin->fin_fi.fi_auth;
 701
 702         READ_ENTER(lock);
 703
 704         /*
 705          * check the table, careful to only compare the right amount of data
 706          */
 707         for (f = table[idx]; f; f = f->ipfr_hnext) {
 708                 if (!bcmp((char *)&frag.ipfr_ifp, (char *)&f->ipfr_ifp,
 709                           IPFR_CMPSZ)) {
 710                         u_short off;
 711
 712                         /*
 713                          * XXX - We really need to be guarding against the
 714                          * retransmission of (src,dst,id,offset-range) here
 715                          * because a fragmented packet is never resent with
 716                          * the same IP ID# (or shouldn't).
 717                          */
 718                         off = fin->fin_off >> 3;
 719                         if (f->ipfr_seen0) {
 720                                 if (off == 0) {
 721                                         FBUMPD(ifs_retrans0);
 722                                         continue;
 723                                 }
 724
 725                                 /*
 726                                  * Case 3. See comment for frpr_fragment6.
 727                                  */
 728                                 if ((f->ipfr_firstend != 0) &&
 729                                     (off < f->ipfr_firstend)) {
 730                                         FBUMP(ifs_overlap);
 731                                         DT2(ifs_overlap, u_short, off,
 732                                             ipfr_t *, f);
 733                                         DT3(ipf_fi_bad_ifs_overlap, fr_info_t *, fin, u_short, off,
 734                                             ipfr_t *, f);
 735                                         fin->fin_flx |= FI_BAD;
 736                                         break;
 737                                 }
 738                         } else if (off == 0)
 739                                 f->ipfr_seen0 = 1;
 740
 741                         if (f != table[idx] && MUTEX_TRY_UPGRADE(lock)) {
 742                                 ipfr_t **fp;
 743
 744                                 /*
 745                                  * Move fragment info. to the top of the list
 746                                  * to speed up searches.  First, delink...
 747                                  */
 748                                 fp = f->ipfr_hprev;
 749                                 (*fp) = f->ipfr_hnext;
 750                                 if (f->ipfr_hnext != NULL)
 751                                         f->ipfr_hnext->ipfr_hprev = fp;
 752                                 /*
 753                                  * Then put back at the top of the chain.
 754                                  */
 755                                 f->ipfr_hnext = table[idx];
 756                                 table[idx]->ipfr_hprev = &f->ipfr_hnext;
 757                                 f->ipfr_hprev = table + idx;
 758                                 table[idx] = f;
 759                                 MUTEX_DOWNGRADE(lock);
 760                         }
 761
 762                         /*
 763                          * If we've follwed the fragments, and this is the
 764                          * last (in order), shrink expiration time.
 765                          */
 766                         if (off == f->ipfr_off) {
 767                                 f->ipfr_off = (fin->fin_dlen >> 3) + off;
 768
 769                                 /*
 770                                  * Well, we could shrink the expiration time
 771                                  * but only if every fragment has been seen
 772                                  * in order upto this, the last. ipfr_badorder
 773                                  * is used here to count those out of order
 774                                  * and if it equals 0 when we get to the last
 775                                  * fragment then we can assume all of the
 776                                  * fragments have been seen and in order.
 777                                  */
 778 #if 0
 779                                 /*
 780                                  * Doing this properly requires moving it to
 781                                  * the head of the list which is infesible.
 782                                  */
 783                                 if ((more == 0) && (f->ipfr_badorder == 0))
 784                                         f->ipfr_ttl = softc->ipf_ticks + 1;
 785 #endif
 786                         } else {
 787                                 f->ipfr_badorder++;
 788                                 FBUMPD(ifs_unordered);
 789                                 if (f->ipfr_pass & FR_FRSTRICT) {
 790                                         FBUMPD(ifs_strict);
 791                                         continue;
 792                                 }
 793                         }
 794                         f->ipfr_pkts++;
 795                         f->ipfr_bytes += fin->fin_plen;
 796                         FBUMP(ifs_hits);
 797                         return f;
 798                 }
 799         }
 800
 801         RWLOCK_EXIT(lock);
 802         FBUMP(ifs_miss);
 803         return NULL;
 804 }
 805
 806
 807 /* ------------------------------------------------------------------------ */
 808 /* Function:    ipf_frag_natknown                                           */
 809 /* Returns:     nat_t* - pointer to 'parent' NAT structure if frag table    */
 810 /*                       match found, else NULL                             */
 811 /* Parameters:  fin(I)  - pointer to packet information                     */
 812 /*                                                                          */
 813 /* Functional interface for NAT lookups of the NAT fragment cache           */
 814 /* ------------------------------------------------------------------------ */
 815 nat_t *
 816 ipf_frag_natknown(fin)
 817         fr_info_t *fin;
 818 {
 819         ipf_main_softc_t *softc = fin->fin_main_soft;
 820         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 821         nat_t   *nat;
 822         ipfr_t  *ipf;
 823
 824         if ((softf->ipfr_lock) || !softf->ipfr_natlist)
 825                 return NULL;
 826 #ifdef USE_MUTEXES
 827         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_nattab,
 828                               &softf->ipfr_natfrag);
 829 #else
 830         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_nattab);
 831 #endif
 832         if (ipf != NULL) {
 833                 nat = ipf->ipfr_data;
 834                 /*
 835                  * This is the last fragment for this packet.
 836                  */
 837                 if ((ipf->ipfr_ttl == softc->ipf_ticks + 1) && (nat != NULL)) {
 838                         nat->nat_data = NULL;
 839                         ipf->ipfr_data = NULL;
 840                 }
 841                 RWLOCK_EXIT(&softf->ipfr_natfrag);
 842         } else
 843                 nat = NULL;
 844         return nat;
 845 }
 846
 847
 848 /* ------------------------------------------------------------------------ */
 849 /* Function:    ipf_frag_ipidknown                                          */
 850 /* Returns:     u_32_t - IPv4 ID for this packet if match found, else       */
 851 /*                       return 0xfffffff to indicate no match.             */
 852 /* Parameters:  fin(I) - pointer to packet information                      */
 853 /*                                                                          */
 854 /* Functional interface for IP ID lookups of the IP ID fragment cache       */
 855 /* ------------------------------------------------------------------------ */
 856 u_32_t
 857 ipf_frag_ipidknown(fin)
 858         fr_info_t *fin;
 859 {
 860         ipf_main_softc_t *softc = fin->fin_main_soft;
 861         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 862         ipfr_t  *ipf;
 863         u_32_t  id;
 864
 865         if (softf->ipfr_lock || !softf->ipfr_ipidlist)
 866                 return 0xffffffff;
 867
 868 #ifdef USE_MUTEXES
 869         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_ipidtab,
 870                               &softf->ipfr_ipidfrag);
 871 #else
 872         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_ipidtab);
 873 #endif
 874         if (ipf != NULL) {
 875                 id = (u_32_t)(intptr_t)ipf->ipfr_data;
 876                 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
 877         } else
 878                 id = 0xffffffff;
 879         return id;
 880 }
 881
 882
 883 /* ------------------------------------------------------------------------ */
 884 /* Function:    ipf_frag_known                                              */
 885 /* Returns:     frentry_t* - pointer to filter rule if a match is found in  */
 886 /*                           the frag cache table, else NULL.               */
 887 /* Parameters:  fin(I)   - pointer to packet information                    */
 888 /*              passp(O) - pointer to where to store rule flags resturned   */
 889 /*                                                                          */
 890 /* Functional interface for normal lookups of the fragment cache.  If a     */
 891 /* match is found, return the rule pointer and flags from the rule, except  */
 892 /* that if FR_LOGFIRST is set, reset FR_LOG.                                */
 893 /* ------------------------------------------------------------------------ */
 894 frentry_t *
 895 ipf_frag_known(fin, passp)
 896         fr_info_t *fin;
 897         u_32_t *passp;
 898 {
 899         ipf_main_softc_t *softc = fin->fin_main_soft;
 900         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 901         frentry_t *fr = NULL;
 902         ipfr_t  *fra;
 903         u_32_t pass;
 904
 905         if ((softf->ipfr_lock) || (softf->ipfr_list == NULL))
 906                 return NULL;
 907
 908 #ifdef USE_MUTEXES
 909         fra = ipf_frag_lookup(softc, softf, fin, softf->ipfr_heads,
 910                               &softc->ipf_frag);
 911 #else
 912         fra = ipf_frag_lookup(softc, softf, fin, softf->ipfr_heads);
 913 #endif
 914         if (fra != NULL) {
 915                 if (fin->fin_flx & FI_BAD) {
 916                         fr = &ipfr_block;
 917                         fin->fin_reason = FRB_BADFRAG;
 918                         DT2(ipf_frb_badfrag, fr_info_t *, fin, uint, fra);
 919                 } else {
 920                         fr = fra->ipfr_rule;
 921                 }
 922                 fin->fin_fr = fr;
 923                 if (fr != NULL) {
 924                         pass = fr->fr_flags;
 925                         if ((pass & FR_KEEPSTATE) != 0) {
 926                                 fin->fin_flx |= FI_STATE;
 927                                 /*
 928                                  * Reset the keep state flag here so that we
 929                                  * don't try and add a new state entry because
 930                                  * of a match here. That leads to blocking of
 931                                  * the packet later because the add fails.
 932                                  */
 933                                 pass &= ~FR_KEEPSTATE;
 934                         }
 935                         if ((pass & FR_LOGFIRST) != 0)
 936                                 pass &= ~(FR_LOGFIRST|FR_LOG);
 937                         *passp = pass;
 938                 }
 939                 RWLOCK_EXIT(&softc->ipf_frag);
 940         }
 941         return fr;
 942 }
 943
 944
 945 /* ------------------------------------------------------------------------ */
 946 /* Function:    ipf_frag_natforget                                          */
 947 /* Returns:     Nil                                                         */
 948 /* Parameters:  softc(I) - pointer to soft context main structure           */
 949 /*              ptr(I) - pointer to data structure                          */
 950 /*                                                                          */
 951 /* Search through all of the fragment cache entries for NAT and wherever a  */
 952 /* pointer  is found to match ptr, reset it to NULL.                        */
 953 /* ------------------------------------------------------------------------ */
 954 void
 955 ipf_frag_natforget(softc, ptr)
 956         ipf_main_softc_t *softc;
 957         void *ptr;
 958 {
 959         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 960         ipfr_t  *fr;
 961
 962         WRITE_ENTER(&softf->ipfr_natfrag);
 963         for (fr = softf->ipfr_natlist; fr; fr = fr->ipfr_next)
 964                 if (fr->ipfr_data == ptr)
 965                         fr->ipfr_data = NULL;
 966         RWLOCK_EXIT(&softf->ipfr_natfrag);
 967 }
 968
 969
 970 /* ------------------------------------------------------------------------ */
 971 /* Function:    ipf_frag_delete                                             */
 972 /* Returns:     Nil                                                         */
 973 /* Parameters:  softc(I) - pointer to soft context main structure           */
 974 /*              fra(I)   - pointer to fragment structure to delete          */
 975 /*              tail(IO) - pointer to the pointer to the tail of the frag   */
 976 /*                         list                                             */
 977 /*                                                                          */
 978 /* Remove a fragment cache table entry from the table & list.  Also free    */
 979 /* the filter rule it is associated with it if it is no longer used as a    */
 980 /* result of decreasing the reference count.                                */
 981 /* ------------------------------------------------------------------------ */
 982 static void
 983 ipf_frag_delete(softc, fra, tail)
 984         ipf_main_softc_t *softc;
 985         ipfr_t *fra, ***tail;
 986 {
 987         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 988
 989         if (fra->ipfr_next)
 990                 fra->ipfr_next->ipfr_prev = fra->ipfr_prev;
 991         *fra->ipfr_prev = fra->ipfr_next;
 992         if (*tail == &fra->ipfr_next)
 993                 *tail = fra->ipfr_prev;
 994
 995         if (fra->ipfr_hnext)
 996                 fra->ipfr_hnext->ipfr_hprev = fra->ipfr_hprev;
 997         *fra->ipfr_hprev = fra->ipfr_hnext;
 998
 999         if (fra->ipfr_rule != NULL) {
1000                 (void) ipf_derefrule(softc, &fra->ipfr_rule);
1001         }
1002
1003         if (fra->ipfr_ref <= 0)
1004                 ipf_frag_free(softf, fra);
1005 }
1006
1007
1008 /* ------------------------------------------------------------------------ */
1009 /* Function:    ipf_frag_free                                               */
1010 /* Returns:     Nil                                                         */
1011 /* Parameters:  softf(I) - pointer to fragment context information          */
1012 /*              fra(I)   - pointer to fragment structure to free            */
1013 /*                                                                          */
1014 /* Free up a fragment cache entry and bump relevent statistics.             */
1015 /* ------------------------------------------------------------------------ */
1016 static void
1017 ipf_frag_free(softf, fra)
1018         ipf_frag_softc_t *softf;
1019         ipfr_t *fra;
1020 {
1021         KFREE(fra);
1022         FBUMP(ifs_expire);
1023         softf->ipfr_stats.ifs_inuse--;
1024 }
1025
1026
1027 /* ------------------------------------------------------------------------ */
1028 /* Function:    ipf_frag_clear                                              */
1029 /* Returns:     Nil                                                         */
1030 /* Parameters:  softc(I) - pointer to soft context main structure           */
1031 /*                                                                          */
1032 /* Free memory in use by fragment state information kept.  Do the normal    */
1033 /* fragment state stuff first and then the NAT-fragment table.              */
1034 /* ------------------------------------------------------------------------ */
1035 void
1036 ipf_frag_clear(softc)
1037         ipf_main_softc_t *softc;
1038 {
1039         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1040         ipfr_t  *fra;
1041         nat_t   *nat;
1042
1043         WRITE_ENTER(&softc->ipf_frag);
1044         while ((fra = softf->ipfr_list) != NULL) {
1045                 fra->ipfr_ref--;
1046                 ipf_frag_delete(softc, fra, &softf->ipfr_tail);
1047         }
1048         softf->ipfr_tail = &softf->ipfr_list;
1049         RWLOCK_EXIT(&softc->ipf_frag);
1050
1051         WRITE_ENTER(&softc->ipf_nat);
1052         WRITE_ENTER(&softf->ipfr_natfrag);
1053         while ((fra = softf->ipfr_natlist) != NULL) {
1054                 nat = fra->ipfr_data;
1055                 if (nat != NULL) {
1056                         if (nat->nat_data == fra)
1057                                 nat->nat_data = NULL;
1058                 }
1059                 fra->ipfr_ref--;
1060                 ipf_frag_delete(softc, fra, &softf->ipfr_nattail);
1061         }
1062         softf->ipfr_nattail = &softf->ipfr_natlist;
1063         RWLOCK_EXIT(&softf->ipfr_natfrag);
1064         RWLOCK_EXIT(&softc->ipf_nat);
1065 }
1066
1067
1068 /* ------------------------------------------------------------------------ */
1069 /* Function:    ipf_frag_expire                                             */
1070 /* Returns:     Nil                                                         */
1071 /* Parameters:  softc(I) - pointer to soft context main structure           */
1072 /*                                                                          */
1073 /* Expire entries in the fragment cache table that have been there too long */
1074 /* ------------------------------------------------------------------------ */
1075 void
1076 ipf_frag_expire(softc)
1077         ipf_main_softc_t *softc;
1078 {
1079         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1080         ipfr_t  **fp, *fra;
1081         nat_t   *nat;
1082         SPL_INT(s);
1083
1084         if (softf->ipfr_lock)
1085                 return;
1086
1087         SPL_NET(s);
1088         WRITE_ENTER(&softc->ipf_frag);
1089         /*
1090          * Go through the entire table, looking for entries to expire,
1091          * which is indicated by the ttl being less than or equal to ipf_ticks.
1092          */
1093         for (fp = &softf->ipfr_list; ((fra = *fp) != NULL); ) {
1094                 if (fra->ipfr_ttl > softc->ipf_ticks)
1095                         break;
1096                 fra->ipfr_ref--;
1097                 ipf_frag_delete(softc, fra, &softf->ipfr_tail);
1098         }
1099         RWLOCK_EXIT(&softc->ipf_frag);
1100
1101         WRITE_ENTER(&softf->ipfr_ipidfrag);
1102         for (fp = &softf->ipfr_ipidlist; ((fra = *fp) != NULL); ) {
1103                 if (fra->ipfr_ttl > softc->ipf_ticks)
1104                         break;
1105                 fra->ipfr_ref--;
1106                 ipf_frag_delete(softc, fra, &softf->ipfr_ipidtail);
1107         }
1108         RWLOCK_EXIT(&softf->ipfr_ipidfrag);
1109
1110         /*
1111          * Same again for the NAT table, except that if the structure also
1112          * still points to a NAT structure, and the NAT structure points back
1113          * at the one to be free'd, NULL the reference from the NAT struct.
1114          * NOTE: We need to grab both mutex's early, and in this order so as
1115          * to prevent a deadlock if both try to expire at the same time.
1116          * The extra if() statement here is because it locks out all NAT
1117          * operations - no need to do that if there are no entries in this
1118          * list, right?
1119          */
1120         if (softf->ipfr_natlist != NULL) {
1121                 WRITE_ENTER(&softc->ipf_nat);
1122                 WRITE_ENTER(&softf->ipfr_natfrag);
1123                 for (fp = &softf->ipfr_natlist; ((fra = *fp) != NULL); ) {
1124                         if (fra->ipfr_ttl > softc->ipf_ticks)
1125                                 break;
1126                         nat = fra->ipfr_data;
1127                         if (nat != NULL) {
1128                                 if (nat->nat_data == fra)
1129                                         nat->nat_data = NULL;
1130                         }
1131                         fra->ipfr_ref--;
1132                         ipf_frag_delete(softc, fra, &softf->ipfr_nattail);
1133                 }
1134                 RWLOCK_EXIT(&softf->ipfr_natfrag);
1135                 RWLOCK_EXIT(&softc->ipf_nat);
1136         }
1137         SPL_X(s);
1138 }
1139
1140
1141 /* ------------------------------------------------------------------------ */
1142 /* Function:    ipf_frag_pkt_next                                           */
1143 /* Returns:     int      - 0 == success, else error                         */
1144 /* Parameters:  softc(I) - pointer to soft context main structure           */
1145 /*              token(I) - pointer to token information for this caller     */
1146 /*              itp(I)   - pointer to generic iterator from caller          */
1147 /*                                                                          */
1148 /* This function is used to step through the fragment cache list used for   */
1149 /* filter rules. The hard work is done by the more generic ipf_frag_next.   */
1150 /* ------------------------------------------------------------------------ */
1151 int
1152 ipf_frag_pkt_next(softc, token, itp)
1153         ipf_main_softc_t *softc;
1154         ipftoken_t *token;
1155         ipfgeniter_t *itp;
1156 {
1157         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1158
1159 #ifdef USE_MUTEXES
1160         return ipf_frag_next(softc, token, itp, &softf->ipfr_list,
1161                              &softf->ipfr_frag);
1162 #else
1163         return ipf_frag_next(softc, token, itp, &softf->ipfr_list);
1164 #endif
1165 }
1166
1167
1168 /* ------------------------------------------------------------------------ */
1169 /* Function:    ipf_frag_nat_next                                           */
1170 /* Returns:     int      - 0 == success, else error                         */
1171 /* Parameters:  softc(I) - pointer to soft context main structure           */
1172 /*              token(I) - pointer to token information for this caller     */
1173 /*              itp(I)   - pointer to generic iterator from caller          */
1174 /*                                                                          */
1175 /* This function is used to step through the fragment cache list used for   */
1176 /* NAT. The hard work is done by the more generic ipf_frag_next.            */
1177 /* ------------------------------------------------------------------------ */
1178 int
1179 ipf_frag_nat_next(softc, token, itp)
1180         ipf_main_softc_t *softc;
1181         ipftoken_t *token;
1182         ipfgeniter_t *itp;
1183 {
1184         ipf_frag_softc_t *softf = softc->ipf_frag_soft;;
1185
1186 #ifdef USE_MUTEXES
1187         return ipf_frag_next(softc, token, itp, &softf->ipfr_natlist,
1188                              &softf->ipfr_natfrag);
1189 #else
1190         return ipf_frag_next(softc, token, itp, &softf->ipfr_natlist);
1191 #endif
1192 }
1193
1194 /* ------------------------------------------------------------------------ */
1195 /* Function:    ipf_frag_next                                               */
1196 /* Returns:     int      - 0 == success, else error                         */
1197 /* Parameters:  softc(I) - pointer to soft context main structure           */
1198 /*              token(I) - pointer to token information for this caller     */
1199 /*              itp(I)   - pointer to generic iterator from caller          */
1200 /*              top(I)   - top of the fragment list                         */
1201 /*              lock(I)  - fragment cache lock                              */
1202 /*                                                                          */
1203 /* This function is used to interate through the list of entries in the     */
1204 /* fragment cache.  It increases the reference count on the one currently   */
1205 /* being returned so that the caller can come back and resume from it later.*/
1206 /*                                                                          */
1207 /* This function is used for both the NAT fragment cache as well as the ipf */
1208 /* fragment cache - hence the reason for passing in top and lock.           */
1209 /* ------------------------------------------------------------------------ */
1210 static int
1211 ipf_frag_next(softc, token, itp, top
1212 #ifdef USE_MUTEXES
1213 , lock
1214 #endif
1215 )
1216         ipf_main_softc_t *softc;
1217         ipftoken_t *token;
1218         ipfgeniter_t *itp;
1219         ipfr_t **top;
1220 #ifdef USE_MUTEXES
1221         ipfrwlock_t *lock;
1222 #endif
1223 {
1224         ipfr_t *frag, *next, zero;
1225         int error = 0;
1226
1227         if (itp->igi_data == NULL) {
1228                 IPFERROR(20001);
1229                 return EFAULT;
1230         }
1231
1232         if (itp->igi_nitems != 1) {
1233                 IPFERROR(20003);
1234                 return EFAULT;
1235         }
1236
1237         frag = token->ipt_data;
1238
1239         READ_ENTER(lock);
1240
1241         if (frag == NULL)
1242                 next = *top;
1243         else
1244                 next = frag->ipfr_next;
1245
1246         if (next != NULL) {
1247                 ATOMIC_INC(next->ipfr_ref);
1248                 token->ipt_data = next;
1249         } else {
1250                 bzero(&zero, sizeof(zero));
1251                 next = &zero;
1252                 token->ipt_data = NULL;
1253         }
1254         if (next->ipfr_next == NULL)
1255                 ipf_token_mark_complete(token);
1256
1257         RWLOCK_EXIT(lock);
1258
1259         error = COPYOUT(next, itp->igi_data, sizeof(*next));
1260         if (error != 0)
1261                 IPFERROR(20002);
1262
1263         if (frag != NULL) {
1264 #ifdef USE_MUTEXES
1265                 ipf_frag_deref(softc, &frag, lock);
1266 #else
1267                 ipf_frag_deref(softc, &frag);
1268 #endif
1269         }
1270         return error;
1271 }
1272
1273
1274 /* ------------------------------------------------------------------------ */
1275 /* Function:    ipf_frag_pkt_deref                                          */
1276 /* Returns:     Nil                                                         */
1277 /* Parameters:  softc(I) - pointer to soft context main structure           */
1278 /*              data(I)  - pointer to frag cache pointer                    */
1279 /*                                                                          */
1280 /* This function is the external interface for dropping a reference to a    */
1281 /* fragment cache entry used by filter rules.                               */
1282 /* ------------------------------------------------------------------------ */
1283 void
1284 ipf_frag_pkt_deref(softc, data)
1285         ipf_main_softc_t *softc;
1286         void *data;
1287 {
1288         ipfr_t **frp = data;
1289
1290 #ifdef USE_MUTEXES
1291         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1292
1293         ipf_frag_deref(softc->ipf_frag_soft, frp, &softf->ipfr_frag);
1294 #else
1295         ipf_frag_deref(softc->ipf_frag_soft, frp);
1296 #endif
1297 }
1298
1299
1300 /* ------------------------------------------------------------------------ */
1301 /* Function:    ipf_frag_nat_deref                                          */
1302 /* Returns:     Nil                                                         */
1303 /* Parameters:  softc(I) - pointer to soft context main structure           */
1304 /*              data(I)  - pointer to frag cache pointer                    */
1305 /*                                                                          */
1306 /* This function is the external interface for dropping a reference to a    */
1307 /* fragment cache entry used by NAT table entries.                          */
1308 /* ------------------------------------------------------------------------ */
1309 void
1310 ipf_frag_nat_deref(softc, data)
1311         ipf_main_softc_t *softc;
1312         void *data;
1313 {
1314         ipfr_t **frp = data;
1315
1316 #ifdef USE_MUTEXES
1317         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1318
1319         ipf_frag_deref(softc->ipf_frag_soft, frp, &softf->ipfr_natfrag);
1320 #else
1321         ipf_frag_deref(softc->ipf_frag_soft, frp);
1322 #endif
1323 }
1324
1325
1326 /* ------------------------------------------------------------------------ */
1327 /* Function:    ipf_frag_deref                                              */
1328 /* Returns:     Nil                                                         */
1329 /* Parameters:  frp(IO) - pointer to fragment structure to deference        */
1330 /*              lock(I) - lock associated with the fragment                 */
1331 /*                                                                          */
1332 /* This function dereferences a fragment structure (ipfr_t).  The pointer   */
1333 /* passed in will always be reset back to NULL, even if the structure is    */
1334 /* not freed, to enforce the notion that the caller is no longer entitled   */
1335 /* to use the pointer it is dropping the reference to.                      */
1336 /* ------------------------------------------------------------------------ */
1337 static void
1338 ipf_frag_deref(arg, frp
1339 #ifdef USE_MUTEXES
1340 , lock
1341 #endif
1342 )
1343         void *arg;
1344         ipfr_t **frp;
1345 #ifdef USE_MUTEXES
1346         ipfrwlock_t *lock;
1347 #endif
1348 {
1349         ipf_frag_softc_t *softf = arg;
1350         ipfr_t *fra;
1351
1352         fra = *frp;
1353         *frp = NULL;
1354
1355         WRITE_ENTER(lock);
1356         fra->ipfr_ref--;
1357         if (fra->ipfr_ref <= 0)
1358                 ipf_frag_free(softf, fra);
1359         RWLOCK_EXIT(lock);
1360 }