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) && !defined(__svr4__)
  38 #  include <sys/mbuf.h>
  39 # endif
  40 #endif
  41 #if !defined(__SVR4) && !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         frag.ipfr_v = fin->fin_v;
 408         idx = fin->fin_v;
 409         frag.ipfr_p = fin->fin_p;
 410         idx += fin->fin_p;
 411         frag.ipfr_id = fin->fin_id;
 412         idx += fin->fin_id;
 413         frag.ipfr_source = fin->fin_fi.fi_src;
 414         idx += frag.ipfr_src.s_addr;
 415         frag.ipfr_dest = fin->fin_fi.fi_dst;
 416         idx += frag.ipfr_dst.s_addr;
 417         frag.ipfr_ifp = fin->fin_ifp;
 418         idx *= 127;
 419         idx %= softf->ipfr_size;
 420
 421         frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY;
 422         frag.ipfr_secmsk = fin->fin_fi.fi_secmsk;
 423         frag.ipfr_auth = fin->fin_fi.fi_auth;
 424
 425         off = fin->fin_off >> 3;
 426         if (off == 0) {
 427                 char *ptr;
 428                 int end;
 429
 430 #ifdef USE_INET6
 431                 if (fin->fin_v == 6) {
 432
 433                         ptr = (char *)fin->fin_fraghdr +
 434                               sizeof(struct ip6_frag);
 435                 } else
 436 #endif
 437                 {
 438                         ptr = fin->fin_dp;
 439                 }
 440                 end = fin->fin_plen - (ptr - (char *)fin->fin_ip);
 441                 frag.ipfr_firstend = end >> 3;
 442         } else {
 443                 frag.ipfr_firstend = 0;
 444         }
 445
 446         /*
 447          * allocate some memory, if possible, if not, just record that we
 448          * failed to do so.
 449          */
 450         KMALLOC(fran, ipfr_t *);
 451         if (fran == NULL) {
 452                 FBUMPD(ifs_nomem);
 453                 return NULL;
 454         }
 455
 456         WRITE_ENTER(lock);
 457
 458         /*
 459          * first, make sure it isn't already there...
 460          */
 461         for (fra = table[idx]; (fra != NULL); fra = fra->ipfr_hnext)
 462                 if (!bcmp((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp,
 463                           IPFR_CMPSZ)) {
 464                         RWLOCK_EXIT(lock);
 465                         FBUMPD(ifs_exists);
 466                         KFREE(fran);
 467                         return NULL;
 468                 }
 469
 470         fra = fran;
 471         fran = NULL;
 472         fr = fin->fin_fr;
 473         fra->ipfr_rule = fr;
 474         if (fr != NULL) {
 475                 MUTEX_ENTER(&fr->fr_lock);
 476                 fr->fr_ref++;
 477                 MUTEX_EXIT(&fr->fr_lock);
 478         }
 479
 480         /*
 481          * Insert the fragment into the fragment table, copy the struct used
 482          * in the search using bcopy rather than reassign each field.
 483          * Set the ttl to the default.
 484          */
 485         if ((fra->ipfr_hnext = table[idx]) != NULL)
 486                 table[idx]->ipfr_hprev = &fra->ipfr_hnext;
 487         fra->ipfr_hprev = table + idx;
 488         fra->ipfr_data = NULL;
 489         table[idx] = fra;
 490         bcopy((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, IPFR_CMPSZ);
 491         fra->ipfr_v = fin->fin_v;
 492         fra->ipfr_ttl = softc->ipf_ticks + softf->ipfr_ttl;
 493         fra->ipfr_firstend = frag.ipfr_firstend;
 494
 495         /*
 496          * Compute the offset of the expected start of the next packet.
 497          */
 498         if (off == 0)
 499                 fra->ipfr_seen0 = 1;
 500         fra->ipfr_off = off + (fin->fin_dlen >> 3);
 501         fra->ipfr_pass = pass;
 502         fra->ipfr_ref = 1;
 503         fra->ipfr_pkts = 1;
 504         fra->ipfr_bytes = fin->fin_plen;
 505         FBUMP(ifs_inuse);
 506         FBUMP(ifs_new);
 507         return fra;
 508 }
 509
 510
 511 /* ------------------------------------------------------------------------ */
 512 /* Function:    ipf_frag_new                                                */
 513 /* Returns:     int - 0 == success, -1 == error                             */
 514 /* Parameters:  fin(I)  - pointer to packet information                     */
 515 /*                                                                          */
 516 /* Add a new entry to the fragment cache table based on the current packet  */
 517 /* ------------------------------------------------------------------------ */
 518 int
 519 ipf_frag_new(softc, fin, pass)
 520         ipf_main_softc_t *softc;
 521         u_32_t pass;
 522         fr_info_t *fin;
 523 {
 524         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 525         ipfr_t  *fra;
 526
 527         if (softf->ipfr_lock != 0)
 528                 return -1;
 529
 530 #ifdef USE_MUTEXES
 531         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_heads, &softc->ipf_frag);
 532 #else
 533         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_heads);
 534 #endif
 535         if (fra != NULL) {
 536                 *softf->ipfr_tail = fra;
 537                 fra->ipfr_prev = softf->ipfr_tail;
 538                 softf->ipfr_tail = &fra->ipfr_next;
 539                 fra->ipfr_next = NULL;
 540                 RWLOCK_EXIT(&softc->ipf_frag);
 541         }
 542         return fra ? 0 : -1;
 543 }
 544
 545
 546 /* ------------------------------------------------------------------------ */
 547 /* Function:    ipf_frag_natnew                                             */
 548 /* Returns:     int - 0 == success, -1 == error                             */
 549 /* Parameters:  fin(I)  - pointer to packet information                     */
 550 /*              nat(I)  - pointer to NAT structure                          */
 551 /*                                                                          */
 552 /* Create a new NAT fragment cache entry based on the current packet and    */
 553 /* the NAT structure for this "session".                                    */
 554 /* ------------------------------------------------------------------------ */
 555 int
 556 ipf_frag_natnew(softc, fin, pass, nat)
 557         ipf_main_softc_t *softc;
 558         fr_info_t *fin;
 559         u_32_t pass;
 560         nat_t *nat;
 561 {
 562         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 563         ipfr_t  *fra;
 564
 565         if (softf->ipfr_lock != 0)
 566                 return 0;
 567
 568 #ifdef USE_MUTEXES
 569         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_nattab,
 570                             &softf->ipfr_natfrag);
 571 #else
 572         fra = ipfr_frag_new(softc, softf, fin, pass, softf->ipfr_nattab);
 573 #endif
 574         if (fra != NULL) {
 575                 fra->ipfr_data = nat;
 576                 nat->nat_data = fra;
 577                 *softf->ipfr_nattail = fra;
 578                 fra->ipfr_prev = softf->ipfr_nattail;
 579                 softf->ipfr_nattail = &fra->ipfr_next;
 580                 fra->ipfr_next = NULL;
 581                 RWLOCK_EXIT(&softf->ipfr_natfrag);
 582                 return 0;
 583         }
 584         return -1;
 585 }
 586
 587
 588 /* ------------------------------------------------------------------------ */
 589 /* Function:    ipf_frag_ipidnew                                            */
 590 /* Returns:     int - 0 == success, -1 == error                             */
 591 /* Parameters:  fin(I)  - pointer to packet information                     */
 592 /*              ipid(I) - new IP ID for this fragmented packet              */
 593 /*                                                                          */
 594 /* Create a new fragment cache entry for this packet and store, as a data   */
 595 /* pointer, the new IP ID value.                                            */
 596 /* ------------------------------------------------------------------------ */
 597 int
 598 ipf_frag_ipidnew(fin, ipid)
 599         fr_info_t *fin;
 600         u_32_t ipid;
 601 {
 602         ipf_main_softc_t *softc = fin->fin_main_soft;
 603         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 604         ipfr_t  *fra;
 605
 606         if (softf->ipfr_lock)
 607                 return 0;
 608
 609 #ifdef USE_MUTEXES
 610         fra = ipfr_frag_new(softc, softf, fin, 0, softf->ipfr_ipidtab, &softf->ipfr_ipidfrag);
 611 #else
 612         fra = ipfr_frag_new(softc, softf, fin, 0, softf->ipfr_ipidtab);
 613 #endif
 614         if (fra != NULL) {
 615                 fra->ipfr_data = (void *)(intptr_t)ipid;
 616                 *softf->ipfr_ipidtail = fra;
 617                 fra->ipfr_prev = softf->ipfr_ipidtail;
 618                 softf->ipfr_ipidtail = &fra->ipfr_next;
 619                 fra->ipfr_next = NULL;
 620                 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
 621         }
 622         return fra ? 0 : -1;
 623 }
 624
 625
 626 /* ------------------------------------------------------------------------ */
 627 /* Function:    ipf_frag_lookup                                             */
 628 /* Returns:     ipfr_t * - pointer to ipfr_t structure if there's a         */
 629 /*                         matching entry in the frag table, else NULL      */
 630 /* Parameters:  fin(I)   - pointer to packet information                    */
 631 /*              table(I) - pointer to fragment cache table to search        */
 632 /*                                                                          */
 633 /* Check the fragment cache to see if there is already a record of this     */
 634 /* packet with its filter result known.                                     */
 635 /*                                                                          */
 636 /* If this function succeeds, it returns with a write lock held on "lock".  */
 637 /* If it fails, no lock is held on return.                                  */
 638 /* ------------------------------------------------------------------------ */
 639 static ipfr_t *
 640 ipf_frag_lookup(softc, softf, fin, table
 641 #ifdef USE_MUTEXES
 642 , lock
 643 #endif
 644 )
 645         ipf_main_softc_t *softc;
 646         ipf_frag_softc_t *softf;
 647         fr_info_t *fin;
 648         ipfr_t *table[];
 649 #ifdef USE_MUTEXES
 650         ipfrwlock_t *lock;
 651 #endif
 652 {
 653         ipfr_t *f, frag;
 654         u_int idx;
 655
 656         /*
 657          * We don't want to let short packets match because they could be
 658          * compromising the security of other rules that want to match on
 659          * layer 4 fields (and can't because they have been fragmented off.)
 660          * Why do this check here?  The counter acts as an indicator of this
 661          * kind of attack, whereas if it was elsewhere, it wouldn't know if
 662          * other matching packets had been seen.
 663          */
 664         if (fin->fin_flx & FI_SHORT) {
 665                 FBUMPD(ifs_short);
 666                 return NULL;
 667         }
 668
 669         if ((fin->fin_flx & FI_BAD) != 0) {
 670                 FBUMPD(ifs_bad);
 671                 return NULL;
 672         }
 673
 674         /*
 675          * For fragments, we record protocol, packet id, TOS and both IP#'s
 676          * (these should all be the same for all fragments of a packet).
 677          *
 678          * build up a hash value to index the table with.
 679          */
 680         frag.ipfr_v = fin->fin_v;
 681         idx = fin->fin_v;
 682         frag.ipfr_p = fin->fin_p;
 683         idx += fin->fin_p;
 684         frag.ipfr_id = fin->fin_id;
 685         idx += fin->fin_id;
 686         frag.ipfr_source = fin->fin_fi.fi_src;
 687         idx += frag.ipfr_src.s_addr;
 688         frag.ipfr_dest = fin->fin_fi.fi_dst;
 689         idx += frag.ipfr_dst.s_addr;
 690         frag.ipfr_ifp = fin->fin_ifp;
 691         idx *= 127;
 692         idx %= softf->ipfr_size;
 693
 694         frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY;
 695         frag.ipfr_secmsk = fin->fin_fi.fi_secmsk;
 696         frag.ipfr_auth = fin->fin_fi.fi_auth;
 697
 698         READ_ENTER(lock);
 699
 700         /*
 701          * check the table, careful to only compare the right amount of data
 702          */
 703         for (f = table[idx]; f; f = f->ipfr_hnext) {
 704                 if (!bcmp((char *)&frag.ipfr_ifp, (char *)&f->ipfr_ifp,
 705                           IPFR_CMPSZ)) {
 706                         u_short off;
 707
 708                         /*
 709                          * XXX - We really need to be guarding against the
 710                          * retransmission of (src,dst,id,offset-range) here
 711                          * because a fragmented packet is never resent with
 712                          * the same IP ID# (or shouldn't).
 713                          */
 714                         off = fin->fin_off >> 3;
 715                         if (f->ipfr_seen0) {
 716                                 if (off == 0) {
 717                                         FBUMPD(ifs_retrans0);
 718                                         continue;
 719                                 }
 720
 721                                 /*
 722                                  * Case 3. See comment for frpr_fragment6.
 723                                  */
 724                                 if ((f->ipfr_firstend != 0) &&
 725                                     (off < f->ipfr_firstend)) {
 726                                         FBUMP(ifs_overlap);
 727                                         DT2(ifs_overlap, u_short, off,
 728                                             ipfr_t *, f);
 729                                         DT3(ipf_fi_bad_ifs_overlap, fr_info_t *, fin, u_short, off,
 730                                             ipfr_t *, f);
 731                                         fin->fin_flx |= FI_BAD;
 732                                         break;
 733                                 }
 734                         } else if (off == 0)
 735                                 f->ipfr_seen0 = 1;
 736
 737                         if (f != table[idx] && MUTEX_TRY_UPGRADE(lock)) {
 738                                 ipfr_t **fp;
 739
 740                                 /*
 741                                  * Move fragment info. to the top of the list
 742                                  * to speed up searches.  First, delink...
 743                                  */
 744                                 fp = f->ipfr_hprev;
 745                                 (*fp) = f->ipfr_hnext;
 746                                 if (f->ipfr_hnext != NULL)
 747                                         f->ipfr_hnext->ipfr_hprev = fp;
 748                                 /*
 749                                  * Then put back at the top of the chain.
 750                                  */
 751                                 f->ipfr_hnext = table[idx];
 752                                 table[idx]->ipfr_hprev = &f->ipfr_hnext;
 753                                 f->ipfr_hprev = table + idx;
 754                                 table[idx] = f;
 755                                 MUTEX_DOWNGRADE(lock);
 756                         }
 757
 758                         /*
 759                          * If we've follwed the fragments, and this is the
 760                          * last (in order), shrink expiration time.
 761                          */
 762                         if (off == f->ipfr_off) {
 763                                 f->ipfr_off = (fin->fin_dlen >> 3) + off;
 764
 765                                 /*
 766                                  * Well, we could shrink the expiration time
 767                                  * but only if every fragment has been seen
 768                                  * in order upto this, the last. ipfr_badorder
 769                                  * is used here to count those out of order
 770                                  * and if it equals 0 when we get to the last
 771                                  * fragment then we can assume all of the
 772                                  * fragments have been seen and in order.
 773                                  */
 774 #if 0
 775                                 /*
 776                                  * Doing this properly requires moving it to
 777                                  * the head of the list which is infesible.
 778                                  */
 779                                 if ((more == 0) && (f->ipfr_badorder == 0))
 780                                         f->ipfr_ttl = softc->ipf_ticks + 1;
 781 #endif
 782                         } else {
 783                                 f->ipfr_badorder++;
 784                                 FBUMPD(ifs_unordered);
 785                                 if (f->ipfr_pass & FR_FRSTRICT) {
 786                                         FBUMPD(ifs_strict);
 787                                         continue;
 788                                 }
 789                         }
 790                         f->ipfr_pkts++;
 791                         f->ipfr_bytes += fin->fin_plen;
 792                         FBUMP(ifs_hits);
 793                         return f;
 794                 }
 795         }
 796
 797         RWLOCK_EXIT(lock);
 798         FBUMP(ifs_miss);
 799         return NULL;
 800 }
 801
 802
 803 /* ------------------------------------------------------------------------ */
 804 /* Function:    ipf_frag_natknown                                           */
 805 /* Returns:     nat_t* - pointer to 'parent' NAT structure if frag table    */
 806 /*                       match found, else NULL                             */
 807 /* Parameters:  fin(I)  - pointer to packet information                     */
 808 /*                                                                          */
 809 /* Functional interface for NAT lookups of the NAT fragment cache           */
 810 /* ------------------------------------------------------------------------ */
 811 nat_t *
 812 ipf_frag_natknown(fin)
 813         fr_info_t *fin;
 814 {
 815         ipf_main_softc_t *softc = fin->fin_main_soft;
 816         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 817         nat_t   *nat;
 818         ipfr_t  *ipf;
 819
 820         if ((softf->ipfr_lock) || !softf->ipfr_natlist)
 821                 return NULL;
 822 #ifdef USE_MUTEXES
 823         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_nattab,
 824                               &softf->ipfr_natfrag);
 825 #else
 826         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_nattab);
 827 #endif
 828         if (ipf != NULL) {
 829                 nat = ipf->ipfr_data;
 830                 /*
 831                  * This is the last fragment for this packet.
 832                  */
 833                 if ((ipf->ipfr_ttl == softc->ipf_ticks + 1) && (nat != NULL)) {
 834                         nat->nat_data = NULL;
 835                         ipf->ipfr_data = NULL;
 836                 }
 837                 RWLOCK_EXIT(&softf->ipfr_natfrag);
 838         } else
 839                 nat = NULL;
 840         return nat;
 841 }
 842
 843
 844 /* ------------------------------------------------------------------------ */
 845 /* Function:    ipf_frag_ipidknown                                          */
 846 /* Returns:     u_32_t - IPv4 ID for this packet if match found, else       */
 847 /*                       return 0xfffffff to indicate no match.             */
 848 /* Parameters:  fin(I) - pointer to packet information                      */
 849 /*                                                                          */
 850 /* Functional interface for IP ID lookups of the IP ID fragment cache       */
 851 /* ------------------------------------------------------------------------ */
 852 u_32_t
 853 ipf_frag_ipidknown(fin)
 854         fr_info_t *fin;
 855 {
 856         ipf_main_softc_t *softc = fin->fin_main_soft;
 857         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 858         ipfr_t  *ipf;
 859         u_32_t  id;
 860
 861         if (softf->ipfr_lock || !softf->ipfr_ipidlist)
 862                 return 0xffffffff;
 863
 864 #ifdef USE_MUTEXES
 865         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_ipidtab,
 866                               &softf->ipfr_ipidfrag);
 867 #else
 868         ipf = ipf_frag_lookup(softc, softf, fin, softf->ipfr_ipidtab);
 869 #endif
 870         if (ipf != NULL) {
 871                 id = (u_32_t)(intptr_t)ipf->ipfr_data;
 872                 RWLOCK_EXIT(&softf->ipfr_ipidfrag);
 873         } else
 874                 id = 0xffffffff;
 875         return id;
 876 }
 877
 878
 879 /* ------------------------------------------------------------------------ */
 880 /* Function:    ipf_frag_known                                              */
 881 /* Returns:     frentry_t* - pointer to filter rule if a match is found in  */
 882 /*                           the frag cache table, else NULL.               */
 883 /* Parameters:  fin(I)   - pointer to packet information                    */
 884 /*              passp(O) - pointer to where to store rule flags resturned   */
 885 /*                                                                          */
 886 /* Functional interface for normal lookups of the fragment cache.  If a     */
 887 /* match is found, return the rule pointer and flags from the rule, except  */
 888 /* that if FR_LOGFIRST is set, reset FR_LOG.                                */
 889 /* ------------------------------------------------------------------------ */
 890 frentry_t *
 891 ipf_frag_known(fin, passp)
 892         fr_info_t *fin;
 893         u_32_t *passp;
 894 {
 895         ipf_main_softc_t *softc = fin->fin_main_soft;
 896         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 897         frentry_t *fr = NULL;
 898         ipfr_t  *fra;
 899         u_32_t pass;
 900
 901         if ((softf->ipfr_lock) || (softf->ipfr_list == NULL))
 902                 return NULL;
 903
 904 #ifdef USE_MUTEXES
 905         fra = ipf_frag_lookup(softc, softf, fin, softf->ipfr_heads,
 906                               &softc->ipf_frag);
 907 #else
 908         fra = ipf_frag_lookup(softc, softf, fin, softf->ipfr_heads);
 909 #endif
 910         if (fra != NULL) {
 911                 if (fin->fin_flx & FI_BAD) {
 912                         fr = &ipfr_block;
 913                         fin->fin_reason = FRB_BADFRAG;
 914                         DT2(ipf_frb_badfrag, fr_info_t *, fin, uint, fra);
 915                 } else {
 916                         fr = fra->ipfr_rule;
 917                 }
 918                 fin->fin_fr = fr;
 919                 if (fr != NULL) {
 920                         pass = fr->fr_flags;
 921                         if ((pass & FR_KEEPSTATE) != 0) {
 922                                 fin->fin_flx |= FI_STATE;
 923                                 /*
 924                                  * Reset the keep state flag here so that we
 925                                  * don't try and add a new state entry because
 926                                  * of a match here. That leads to blocking of
 927                                  * the packet later because the add fails.
 928                                  */
 929                                 pass &= ~FR_KEEPSTATE;
 930                         }
 931                         if ((pass & FR_LOGFIRST) != 0)
 932                                 pass &= ~(FR_LOGFIRST|FR_LOG);
 933                         *passp = pass;
 934                 }
 935                 RWLOCK_EXIT(&softc->ipf_frag);
 936         }
 937         return fr;
 938 }
 939
 940
 941 /* ------------------------------------------------------------------------ */
 942 /* Function:    ipf_frag_natforget                                          */
 943 /* Returns:     Nil                                                         */
 944 /* Parameters:  softc(I) - pointer to soft context main structure           */
 945 /*              ptr(I) - pointer to data structure                          */
 946 /*                                                                          */
 947 /* Search through all of the fragment cache entries for NAT and wherever a  */
 948 /* pointer  is found to match ptr, reset it to NULL.                        */
 949 /* ------------------------------------------------------------------------ */
 950 void
 951 ipf_frag_natforget(softc, ptr)
 952         ipf_main_softc_t *softc;
 953         void *ptr;
 954 {
 955         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 956         ipfr_t  *fr;
 957
 958         WRITE_ENTER(&softf->ipfr_natfrag);
 959         for (fr = softf->ipfr_natlist; fr; fr = fr->ipfr_next)
 960                 if (fr->ipfr_data == ptr)
 961                         fr->ipfr_data = NULL;
 962         RWLOCK_EXIT(&softf->ipfr_natfrag);
 963 }
 964
 965
 966 /* ------------------------------------------------------------------------ */
 967 /* Function:    ipf_frag_delete                                             */
 968 /* Returns:     Nil                                                         */
 969 /* Parameters:  softc(I) - pointer to soft context main structure           */
 970 /*              fra(I)   - pointer to fragment structure to delete          */
 971 /*              tail(IO) - pointer to the pointer to the tail of the frag   */
 972 /*                         list                                             */
 973 /*                                                                          */
 974 /* Remove a fragment cache table entry from the table & list.  Also free    */
 975 /* the filter rule it is associated with it if it is no longer used as a    */
 976 /* result of decreasing the reference count.                                */
 977 /* ------------------------------------------------------------------------ */
 978 static void
 979 ipf_frag_delete(softc, fra, tail)
 980         ipf_main_softc_t *softc;
 981         ipfr_t *fra, ***tail;
 982 {
 983         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
 984
 985         if (fra->ipfr_next)
 986                 fra->ipfr_next->ipfr_prev = fra->ipfr_prev;
 987         *fra->ipfr_prev = fra->ipfr_next;
 988         if (*tail == &fra->ipfr_next)
 989                 *tail = fra->ipfr_prev;
 990
 991         if (fra->ipfr_hnext)
 992                 fra->ipfr_hnext->ipfr_hprev = fra->ipfr_hprev;
 993         *fra->ipfr_hprev = fra->ipfr_hnext;
 994
 995         if (fra->ipfr_rule != NULL) {
 996                 (void) ipf_derefrule(softc, &fra->ipfr_rule);
 997         }
 998
 999         if (fra->ipfr_ref <= 0)
1000                 ipf_frag_free(softf, fra);
1001 }
1002
1003
1004 /* ------------------------------------------------------------------------ */
1005 /* Function:    ipf_frag_free                                               */
1006 /* Returns:     Nil                                                         */
1007 /* Parameters:  softf(I) - pointer to fragment context information          */
1008 /*              fra(I)   - pointer to fragment structure to free            */
1009 /*                                                                          */
1010 /* Free up a fragment cache entry and bump relevent statistics.             */
1011 /* ------------------------------------------------------------------------ */
1012 static void
1013 ipf_frag_free(softf, fra)
1014         ipf_frag_softc_t *softf;
1015         ipfr_t *fra;
1016 {
1017         KFREE(fra);
1018         FBUMP(ifs_expire);
1019         softf->ipfr_stats.ifs_inuse--;
1020 }
1021
1022
1023 /* ------------------------------------------------------------------------ */
1024 /* Function:    ipf_frag_clear                                              */
1025 /* Returns:     Nil                                                         */
1026 /* Parameters:  softc(I) - pointer to soft context main structure           */
1027 /*                                                                          */
1028 /* Free memory in use by fragment state information kept.  Do the normal    */
1029 /* fragment state stuff first and then the NAT-fragment table.              */
1030 /* ------------------------------------------------------------------------ */
1031 void
1032 ipf_frag_clear(softc)
1033         ipf_main_softc_t *softc;
1034 {
1035         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1036         ipfr_t  *fra;
1037         nat_t   *nat;
1038
1039         WRITE_ENTER(&softc->ipf_frag);
1040         while ((fra = softf->ipfr_list) != NULL) {
1041                 fra->ipfr_ref--;
1042                 ipf_frag_delete(softc, fra, &softf->ipfr_tail);
1043         }
1044         softf->ipfr_tail = &softf->ipfr_list;
1045         RWLOCK_EXIT(&softc->ipf_frag);
1046
1047         WRITE_ENTER(&softc->ipf_nat);
1048         WRITE_ENTER(&softf->ipfr_natfrag);
1049         while ((fra = softf->ipfr_natlist) != NULL) {
1050                 nat = fra->ipfr_data;
1051                 if (nat != NULL) {
1052                         if (nat->nat_data == fra)
1053                                 nat->nat_data = NULL;
1054                 }
1055                 fra->ipfr_ref--;
1056                 ipf_frag_delete(softc, fra, &softf->ipfr_nattail);
1057         }
1058         softf->ipfr_nattail = &softf->ipfr_natlist;
1059         RWLOCK_EXIT(&softf->ipfr_natfrag);
1060         RWLOCK_EXIT(&softc->ipf_nat);
1061 }
1062
1063
1064 /* ------------------------------------------------------------------------ */
1065 /* Function:    ipf_frag_expire                                             */
1066 /* Returns:     Nil                                                         */
1067 /* Parameters:  softc(I) - pointer to soft context main structure           */
1068 /*                                                                          */
1069 /* Expire entries in the fragment cache table that have been there too long */
1070 /* ------------------------------------------------------------------------ */
1071 void
1072 ipf_frag_expire(softc)
1073         ipf_main_softc_t *softc;
1074 {
1075         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1076         ipfr_t  **fp, *fra;
1077         nat_t   *nat;
1078         SPL_INT(s);
1079
1080         if (softf->ipfr_lock)
1081                 return;
1082
1083         SPL_NET(s);
1084         WRITE_ENTER(&softc->ipf_frag);
1085         /*
1086          * Go through the entire table, looking for entries to expire,
1087          * which is indicated by the ttl being less than or equal to ipf_ticks.
1088          */
1089         for (fp = &softf->ipfr_list; ((fra = *fp) != NULL); ) {
1090                 if (fra->ipfr_ttl > softc->ipf_ticks)
1091                         break;
1092                 fra->ipfr_ref--;
1093                 ipf_frag_delete(softc, fra, &softf->ipfr_tail);
1094         }
1095         RWLOCK_EXIT(&softc->ipf_frag);
1096
1097         WRITE_ENTER(&softf->ipfr_ipidfrag);
1098         for (fp = &softf->ipfr_ipidlist; ((fra = *fp) != NULL); ) {
1099                 if (fra->ipfr_ttl > softc->ipf_ticks)
1100                         break;
1101                 fra->ipfr_ref--;
1102                 ipf_frag_delete(softc, fra, &softf->ipfr_ipidtail);
1103         }
1104         RWLOCK_EXIT(&softf->ipfr_ipidfrag);
1105
1106         /*
1107          * Same again for the NAT table, except that if the structure also
1108          * still points to a NAT structure, and the NAT structure points back
1109          * at the one to be free'd, NULL the reference from the NAT struct.
1110          * NOTE: We need to grab both mutex's early, and in this order so as
1111          * to prevent a deadlock if both try to expire at the same time.
1112          * The extra if() statement here is because it locks out all NAT
1113          * operations - no need to do that if there are no entries in this
1114          * list, right?
1115          */
1116         if (softf->ipfr_natlist != NULL) {
1117                 WRITE_ENTER(&softc->ipf_nat);
1118                 WRITE_ENTER(&softf->ipfr_natfrag);
1119                 for (fp = &softf->ipfr_natlist; ((fra = *fp) != NULL); ) {
1120                         if (fra->ipfr_ttl > softc->ipf_ticks)
1121                                 break;
1122                         nat = fra->ipfr_data;
1123                         if (nat != NULL) {
1124                                 if (nat->nat_data == fra)
1125                                         nat->nat_data = NULL;
1126                         }
1127                         fra->ipfr_ref--;
1128                         ipf_frag_delete(softc, fra, &softf->ipfr_nattail);
1129                 }
1130                 RWLOCK_EXIT(&softf->ipfr_natfrag);
1131                 RWLOCK_EXIT(&softc->ipf_nat);
1132         }
1133         SPL_X(s);
1134 }
1135
1136
1137 /* ------------------------------------------------------------------------ */
1138 /* Function:    ipf_frag_pkt_next                                           */
1139 /* Returns:     int      - 0 == success, else error                         */
1140 /* Parameters:  softc(I) - pointer to soft context main structure           */
1141 /*              token(I) - pointer to token information for this caller     */
1142 /*              itp(I)   - pointer to generic iterator from caller          */
1143 /*                                                                          */
1144 /* This function is used to step through the fragment cache list used for   */
1145 /* filter rules. The hard work is done by the more generic ipf_frag_next.   */
1146 /* ------------------------------------------------------------------------ */
1147 int
1148 ipf_frag_pkt_next(softc, token, itp)
1149         ipf_main_softc_t *softc;
1150         ipftoken_t *token;
1151         ipfgeniter_t *itp;
1152 {
1153         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1154
1155 #ifdef USE_MUTEXES
1156         return ipf_frag_next(softc, token, itp, &softf->ipfr_list,
1157                              &softf->ipfr_frag);
1158 #else
1159         return ipf_frag_next(softc, token, itp, &softf->ipfr_list);
1160 #endif
1161 }
1162
1163
1164 /* ------------------------------------------------------------------------ */
1165 /* Function:    ipf_frag_nat_next                                           */
1166 /* Returns:     int      - 0 == success, else error                         */
1167 /* Parameters:  softc(I) - pointer to soft context main structure           */
1168 /*              token(I) - pointer to token information for this caller     */
1169 /*              itp(I)   - pointer to generic iterator from caller          */
1170 /*                                                                          */
1171 /* This function is used to step through the fragment cache list used for   */
1172 /* NAT. The hard work is done by the more generic ipf_frag_next.            */
1173 /* ------------------------------------------------------------------------ */
1174 int
1175 ipf_frag_nat_next(softc, token, itp)
1176         ipf_main_softc_t *softc;
1177         ipftoken_t *token;
1178         ipfgeniter_t *itp;
1179 {
1180         ipf_frag_softc_t *softf = softc->ipf_frag_soft;;
1181
1182 #ifdef USE_MUTEXES
1183         return ipf_frag_next(softc, token, itp, &softf->ipfr_natlist,
1184                              &softf->ipfr_natfrag);
1185 #else
1186         return ipf_frag_next(softc, token, itp, &softf->ipfr_natlist);
1187 #endif
1188 }
1189
1190 /* ------------------------------------------------------------------------ */
1191 /* Function:    ipf_frag_next                                               */
1192 /* Returns:     int      - 0 == success, else error                         */
1193 /* Parameters:  softc(I) - pointer to soft context main structure           */
1194 /*              token(I) - pointer to token information for this caller     */
1195 /*              itp(I)   - pointer to generic iterator from caller          */
1196 /*              top(I)   - top of the fragment list                         */
1197 /*              lock(I)  - fragment cache lock                              */
1198 /*                                                                          */
1199 /* This function is used to interate through the list of entries in the     */
1200 /* fragment cache.  It increases the reference count on the one currently   */
1201 /* being returned so that the caller can come back and resume from it later.*/
1202 /*                                                                          */
1203 /* This function is used for both the NAT fragment cache as well as the ipf */
1204 /* fragment cache - hence the reason for passing in top and lock.           */
1205 /* ------------------------------------------------------------------------ */
1206 static int
1207 ipf_frag_next(softc, token, itp, top
1208 #ifdef USE_MUTEXES
1209 , lock
1210 #endif
1211 )
1212         ipf_main_softc_t *softc;
1213         ipftoken_t *token;
1214         ipfgeniter_t *itp;
1215         ipfr_t **top;
1216 #ifdef USE_MUTEXES
1217         ipfrwlock_t *lock;
1218 #endif
1219 {
1220         ipfr_t *frag, *next, zero;
1221         int error = 0;
1222
1223         if (itp->igi_data == NULL) {
1224                 IPFERROR(20001);
1225                 return EFAULT;
1226         }
1227
1228         if (itp->igi_nitems != 1) {
1229                 IPFERROR(20003);
1230                 return EFAULT;
1231         }
1232
1233         frag = token->ipt_data;
1234
1235         READ_ENTER(lock);
1236
1237         if (frag == NULL)
1238                 next = *top;
1239         else
1240                 next = frag->ipfr_next;
1241
1242         if (next != NULL) {
1243                 ATOMIC_INC(next->ipfr_ref);
1244                 token->ipt_data = next;
1245         } else {
1246                 bzero(&zero, sizeof(zero));
1247                 next = &zero;
1248                 token->ipt_data = NULL;
1249         }
1250         if (next->ipfr_next == NULL)
1251                 ipf_token_mark_complete(token);
1252
1253         RWLOCK_EXIT(lock);
1254
1255         error = COPYOUT(next, itp->igi_data, sizeof(*next));
1256         if (error != 0)
1257                 IPFERROR(20002);
1258
1259         if (frag != NULL) {
1260 #ifdef USE_MUTEXES
1261                 ipf_frag_deref(softc, &frag, lock);
1262 #else
1263                 ipf_frag_deref(softc, &frag);
1264 #endif
1265         }
1266         return error;
1267 }
1268
1269
1270 /* ------------------------------------------------------------------------ */
1271 /* Function:    ipf_frag_pkt_deref                                          */
1272 /* Returns:     Nil                                                         */
1273 /* Parameters:  softc(I) - pointer to soft context main structure           */
1274 /*              data(I)  - pointer to frag cache pointer                    */
1275 /*                                                                          */
1276 /* This function is the external interface for dropping a reference to a    */
1277 /* fragment cache entry used by filter rules.                               */
1278 /* ------------------------------------------------------------------------ */
1279 void
1280 ipf_frag_pkt_deref(softc, data)
1281         ipf_main_softc_t *softc;
1282         void *data;
1283 {
1284         ipfr_t **frp = data;
1285
1286 #ifdef USE_MUTEXES
1287         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1288
1289         ipf_frag_deref(softc->ipf_frag_soft, frp, &softf->ipfr_frag);
1290 #else
1291         ipf_frag_deref(softc->ipf_frag_soft, frp);
1292 #endif
1293 }
1294
1295
1296 /* ------------------------------------------------------------------------ */
1297 /* Function:    ipf_frag_nat_deref                                          */
1298 /* Returns:     Nil                                                         */
1299 /* Parameters:  softc(I) - pointer to soft context main structure           */
1300 /*              data(I)  - pointer to frag cache pointer                    */
1301 /*                                                                          */
1302 /* This function is the external interface for dropping a reference to a    */
1303 /* fragment cache entry used by NAT table entries.                          */
1304 /* ------------------------------------------------------------------------ */
1305 void
1306 ipf_frag_nat_deref(softc, data)
1307         ipf_main_softc_t *softc;
1308         void *data;
1309 {
1310         ipfr_t **frp = data;
1311
1312 #ifdef USE_MUTEXES
1313         ipf_frag_softc_t *softf = softc->ipf_frag_soft;
1314
1315         ipf_frag_deref(softc->ipf_frag_soft, frp, &softf->ipfr_natfrag);
1316 #else
1317         ipf_frag_deref(softc->ipf_frag_soft, frp);
1318 #endif
1319 }
1320
1321
1322 /* ------------------------------------------------------------------------ */
1323 /* Function:    ipf_frag_deref                                              */
1324 /* Returns:     Nil                                                         */
1325 /* Parameters:  frp(IO) - pointer to fragment structure to deference        */
1326 /*              lock(I) - lock associated with the fragment                 */
1327 /*                                                                          */
1328 /* This function dereferences a fragment structure (ipfr_t).  The pointer   */
1329 /* passed in will always be reset back to NULL, even if the structure is    */
1330 /* not freed, to enforce the notion that the caller is no longer entitled   */
1331 /* to use the pointer it is dropping the reference to.                      */
1332 /* ------------------------------------------------------------------------ */
1333 static void
1334 ipf_frag_deref(arg, frp
1335 #ifdef USE_MUTEXES
1336 , lock
1337 #endif
1338 )
1339         void *arg;
1340         ipfr_t **frp;
1341 #ifdef USE_MUTEXES
1342         ipfrwlock_t *lock;
1343 #endif
1344 {
1345         ipf_frag_softc_t *softf = arg;
1346         ipfr_t *fra;
1347
1348         fra = *frp;
1349         *frp = NULL;
1350
1351         WRITE_ENTER(lock);
1352         fra->ipfr_ref--;
1353         if (fra->ipfr_ref <= 0)
1354                 ipf_frag_free(softf, fra);
1355         RWLOCK_EXIT(lock);
1356 }