sys/contrib/ipfilter/netinet/ip_auth.c

   1 /*
   2  * Copyright (C) 1998-2001 by Darren Reed & Guido van Rooij.
   3  *
   4  * See the IPFILTER.LICENCE file for details on licencing.
   5  */
   6 #include <sys/errno.h>
   7 #include <sys/types.h>
   8 #include <sys/param.h>
   9 #include <sys/time.h>
  10 #include <sys/file.h>
  11 #if !defined(_KERNEL) && !defined(KERNEL)
  12 # include <stdio.h>
  13 # include <stdlib.h>
  14 # include <string.h>
  15 #endif
  16 #if (defined(KERNEL) || defined(_KERNEL)) && (__FreeBSD_version >= 220000)
  17 # include <sys/filio.h>
  18 # include <sys/fcntl.h>
  19 #else
  20 # include <sys/ioctl.h>
  21 #endif
  22 #include <sys/uio.h>
  23 #ifndef linux
  24 # include <sys/protosw.h>
  25 #endif
  26 #include <sys/socket.h>
  27 #if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux)
  28 # include <sys/systm.h>
  29 #endif
  30 #if !defined(__SVR4) && !defined(__svr4__)
  31 # ifndef linux
  32 #  include <sys/mbuf.h>
  33 # endif
  34 #else
  35 # include <sys/filio.h>
  36 # include <sys/byteorder.h>
  37 # ifdef _KERNEL
  38 #  include <sys/dditypes.h>
  39 # endif
  40 # include <sys/stream.h>
  41 # include <sys/kmem.h>
  42 #endif
  43 #if (_BSDI_VERSION >= 199802) || (__FreeBSD_version >= 400000)
  44 # include <sys/queue.h>
  45 #endif
  46 #if defined(__NetBSD__) || defined(__OpenBSD__) || defined(bsdi)
  47 # include <machine/cpu.h>
  48 #endif
  49 #include <net/if.h>
  50 #ifdef sun
  51 # include <net/af.h>
  52 #endif
  53 #include <net/route.h>
  54 #include <netinet/in.h>
  55 #include <netinet/in_systm.h>
  56 #include <netinet/ip.h>
  57 #ifndef KERNEL
  58 # define        KERNEL
  59 # define        NOT_KERNEL
  60 #endif
  61 #ifndef linux
  62 # include <netinet/ip_var.h>
  63 #endif
  64 #ifdef  NOT_KERNEL
  65 # undef KERNEL
  66 #endif
  67 #ifdef __sgi
  68 # ifdef IFF_DRVRLOCK /* IRIX6 */
  69 #  include <sys/hashing.h>
  70 # endif
  71 #endif
  72 #include <netinet/tcp.h>
  73 #if defined(__sgi) && !defined(IFF_DRVRLOCK) /* IRIX < 6 */
  74 extern struct ifqueue   ipintrq;                /* ip packet input queue */
  75 #else
  76 # ifndef linux
  77 #  if __FreeBSD_version >= 300000
  78 #   include <net/if_var.h>
  79 #  endif
  80 #  include <netinet/in_var.h>
  81 #  include <netinet/tcp_fsm.h>
  82 # endif
  83 #endif
  84 #include <netinet/udp.h>
  85 #include <netinet/ip_icmp.h>
  86 #include "netinet/ip_compat.h"
  87 #include <netinet/tcpip.h>
  88 #include "netinet/ip_fil.h"
  89 #include "netinet/ip_auth.h"
  90 #if !SOLARIS && !defined(linux)
  91 # include <net/netisr.h>
  92 # ifdef __FreeBSD__
  93 #  include <machine/cpufunc.h>
  94 # endif
  95 #endif
  96 #if (__FreeBSD_version >= 300000)
  97 # include <sys/malloc.h>
  98 # if (defined(_KERNEL) || defined(KERNEL)) && !defined(IPFILTER_LKM)
  99 #  include <sys/libkern.h>
 100 #  include <sys/systm.h>
 101 # endif
 102 #endif
 103
 104 #if !defined(lint)
 105 /* static const char rcsid[] = "@(#)$Id: ip_auth.c,v 2.11.2.12 2001/07/18 14:57:08 darrenr Exp $"; */
 106 static const char rcsid[] = "@(#)$FreeBSD$";
 107 #endif
 108
 109
 110 #if (SOLARIS || defined(__sgi)) && defined(_KERNEL)
 111 extern KRWLOCK_T ipf_auth, ipf_mutex;
 112 extern kmutex_t ipf_authmx;
 113 # if SOLARIS
 114 extern kcondvar_t ipfauthwait;
 115 # endif
 116 #endif
 117 #ifdef linux
 118 static struct wait_queue *ipfauthwait = NULL;
 119 #endif
 120
 121 int     fr_authsize = FR_NUMAUTH;
 122 int     fr_authused = 0;
 123 int     fr_defaultauthage = 600;
 124 int     fr_auth_lock = 0;
 125 fr_authstat_t   fr_authstats;
 126 static frauth_t fr_auth[FR_NUMAUTH];
 127 mb_t    *fr_authpkts[FR_NUMAUTH];
 128 static int      fr_authstart = 0, fr_authend = 0, fr_authnext = 0;
 129 static frauthent_t      *fae_list = NULL;
 130 frentry_t       *ipauth = NULL,
 131                 *fr_authlist = NULL;
 132
 133
 134 /*
 135  * Check if a packet has authorization.  If the packet is found to match an
 136  * authorization result and that would result in a feedback loop (i.e. it
 137  * will end up returning FR_AUTH) then return FR_BLOCK instead.
 138  */
 139 u_32_t fr_checkauth(ip, fin)
 140 ip_t *ip;
 141 fr_info_t *fin;
 142 {
 143         u_short id = ip->ip_id;
 144         frentry_t *fr;
 145         frauth_t *fra;
 146         u_32_t pass;
 147         int i;
 148
 149         if (fr_auth_lock || !fr_authused)
 150                 return 0;
 151
 152         READ_ENTER(&ipf_auth);
 153         for (i = fr_authstart; i != fr_authend; ) {
 154                 /*
 155                  * index becomes -2 only after an SIOCAUTHW.  Check this in
 156                  * case the same packet gets sent again and it hasn't yet been
 157                  * auth'd.
 158                  */
 159                 fra = fr_auth + i;
 160                 if ((fra->fra_index == -2) && (id == fra->fra_info.fin_id) &&
 161                     !bcmp((char *)fin, (char *)&fra->fra_info, FI_CSIZE)) {
 162                         /*
 163                          * Avoid feedback loop.
 164                          */
 165                         if (!(pass = fra->fra_pass) || (pass & FR_AUTH))
 166                                 pass = FR_BLOCK;
 167                         /*
 168                          * Create a dummy rule for the stateful checking to
 169                          * use and return.  Zero out any values we don't
 170                          * trust from userland!
 171                          */
 172                         if ((pass & FR_KEEPSTATE) || ((pass & FR_KEEPFRAG) &&
 173                              (fin->fin_fi.fi_fl & FI_FRAG))) {
 174                                 KMALLOC(fr, frentry_t *);
 175                                 if (fr) {
 176                                         bcopy((char *)fra->fra_info.fin_fr,
 177                                               fr, sizeof(*fr));
 178                                         fr->fr_grp = NULL;
 179                                         fr->fr_ifa = fin->fin_ifp;
 180                                         fr->fr_func = NULL;
 181                                         fr->fr_ref = 1;
 182                                         fr->fr_flags = pass;
 183 #if BSD >= 199306
 184                                         fr->fr_oifa = NULL;
 185 #endif
 186                                 }
 187                         } else
 188                                 fr = fra->fra_info.fin_fr;
 189                         fin->fin_fr = fr;
 190                         RWLOCK_EXIT(&ipf_auth);
 191                         WRITE_ENTER(&ipf_auth);
 192                         if (fr && fr != fra->fra_info.fin_fr) {
 193                                 fr->fr_next = fr_authlist;
 194                                 fr_authlist = fr;
 195                         }
 196                         fr_authstats.fas_hits++;
 197                         fra->fra_index = -1;
 198                         fr_authused--;
 199                         if (i == fr_authstart) {
 200                                 while (fra->fra_index == -1) {
 201                                         i++;
 202                                         fra++;
 203                                         if (i == FR_NUMAUTH) {
 204                                                 i = 0;
 205                                                 fra = fr_auth;
 206                                         }
 207                                         fr_authstart = i;
 208                                         if (i == fr_authend)
 209                                                 break;
 210                                 }
 211                                 if (fr_authstart == fr_authend) {
 212                                         fr_authnext = 0;
 213                                         fr_authstart = fr_authend = 0;
 214                                 }
 215                         }
 216                         RWLOCK_EXIT(&ipf_auth);
 217                         return pass;
 218                 }
 219                 i++;
 220                 if (i == FR_NUMAUTH)
 221                         i = 0;
 222         }
 223         fr_authstats.fas_miss++;
 224         RWLOCK_EXIT(&ipf_auth);
 225         return 0;
 226 }
 227
 228
 229 /*
 230  * Check if we have room in the auth array to hold details for another packet.
 231  * If we do, store it and wake up any user programs which are waiting to
 232  * hear about these events.
 233  */
 234 int fr_newauth(m, fin, ip)
 235 mb_t *m;
 236 fr_info_t *fin;
 237 ip_t *ip;
 238 {
 239 #if defined(_KERNEL) && SOLARIS
 240         qif_t *qif = fin->fin_qif;
 241 #endif
 242         frauth_t *fra;
 243         int i;
 244
 245         if (fr_auth_lock)
 246                 return 0;
 247
 248         WRITE_ENTER(&ipf_auth);
 249         if (fr_authstart > fr_authend) {
 250                 fr_authstats.fas_nospace++;
 251                 RWLOCK_EXIT(&ipf_auth);
 252                 return 0;
 253         } else {
 254                 if (fr_authused == FR_NUMAUTH) {
 255                         fr_authstats.fas_nospace++;
 256                         RWLOCK_EXIT(&ipf_auth);
 257                         return 0;
 258                 }
 259         }
 260
 261         fr_authstats.fas_added++;
 262         fr_authused++;
 263         i = fr_authend++;
 264         if (fr_authend == FR_NUMAUTH)
 265                 fr_authend = 0;
 266         RWLOCK_EXIT(&ipf_auth);
 267         fra = fr_auth + i;
 268         fra->fra_index = i;
 269         fra->fra_pass = 0;
 270         fra->fra_age = fr_defaultauthage;
 271         bcopy((char *)fin, (char *)&fra->fra_info, sizeof(*fin));
 272 #if SOLARIS && defined(_KERNEL)
 273 # if !defined(sparc)
 274         /*
 275          * No need to copyback here as we want to undo the changes, not keep
 276          * them.
 277          */
 278         if ((ip == (ip_t *)m->b_rptr) && (ip->ip_v == 4))
 279         {
 280                 register u_short bo;
 281
 282                 bo = ip->ip_len;
 283                 ip->ip_len = htons(bo);
 284 # if !SOLARIS && !defined(__NetBSD__) && !defined(__FreeBSD__)
 285                 /* 4.4BSD converts this ip_input.c, but I don't in solaris.c */
 286                 bo = ip->ip_id;
 287                 ip->ip_id = htons(bo);
 288 # endif
 289                 bo = ip->ip_off;
 290                 ip->ip_off = htons(bo);
 291         }
 292 # endif
 293         m->b_rptr -= qif->qf_off;
 294         fr_authpkts[i] = *(mblk_t **)fin->fin_mp;
 295         fra->fra_q = qif->qf_q;
 296         cv_signal(&ipfauthwait);
 297 #else
 298 # if defined(BSD) && !defined(sparc) && (BSD >= 199306)
 299         if (!fin->fin_out) {
 300                 HTONS(ip->ip_len);
 301                 HTONS(ip->ip_off);
 302         }
 303 # endif
 304         fr_authpkts[i] = m;
 305         WAKEUP(&fr_authnext);
 306 #endif
 307         return 1;
 308 }
 309
 310
 311 int fr_auth_ioctl(data, mode, cmd, fr, frptr)
 312 caddr_t data;
 313 int mode;
 314 #if defined(__NetBSD__) || defined(__OpenBSD__) || (FreeBSD_version >= 300003)
 315 u_long cmd;
 316 #else
 317 int cmd;
 318 #endif
 319 frentry_t *fr, **frptr;
 320 {
 321         mb_t *m;
 322 #if defined(_KERNEL) && !SOLARIS
 323         struct ifqueue *ifq;
 324         int s;
 325 #endif
 326         frauth_t auth, *au = &auth, *fra;
 327         frauthent_t *fae, **faep;
 328         int i, error = 0;
 329
 330         switch (cmd)
 331         {
 332         case SIOCSTLCK :
 333                 error = fr_lock(data, &fr_auth_lock);
 334                 break;
 335         case SIOCINIFR :
 336         case SIOCRMIFR :
 337         case SIOCADIFR :
 338                 error = EINVAL;
 339                 break;
 340         case SIOCINAFR :
 341                 error = EINVAL;
 342                 break;
 343         case SIOCRMAFR :
 344         case SIOCADAFR :
 345                 for (faep = &fae_list; (fae = *faep); )
 346                         if (&fae->fae_fr == fr)
 347                                 break;
 348                         else
 349                                 faep = &fae->fae_next;
 350                 if (cmd == SIOCRMAFR) {
 351                         if (!fr || !frptr)
 352                                 error = EINVAL;
 353                         else if (!fae)
 354                                 error = ESRCH;
 355                         else {
 356                                 WRITE_ENTER(&ipf_auth);
 357                                 SPL_NET(s);
 358                                 *faep = fae->fae_next;
 359                                 *frptr = fr->fr_next;
 360                                 SPL_X(s);
 361                                 RWLOCK_EXIT(&ipf_auth);
 362                                 KFREE(fae);
 363                         }
 364                 } else if (fr && frptr) {
 365                         KMALLOC(fae, frauthent_t *);
 366                         if (fae != NULL) {
 367                                 bcopy((char *)fr, (char *)&fae->fae_fr,
 368                                       sizeof(*fr));
 369                                 WRITE_ENTER(&ipf_auth);
 370                                 SPL_NET(s);
 371                                 fae->fae_age = fr_defaultauthage;
 372                                 fae->fae_fr.fr_hits = 0;
 373                                 fae->fae_fr.fr_next = *frptr;
 374                                 *frptr = &fae->fae_fr;
 375                                 fae->fae_next = *faep;
 376                                 *faep = fae;
 377                                 ipauth = &fae_list->fae_fr;
 378                                 SPL_X(s);
 379                                 RWLOCK_EXIT(&ipf_auth);
 380                         } else
 381                                 error = ENOMEM;
 382                 } else
 383                         error = EINVAL;
 384                 break;
 385         case SIOCATHST:
 386                 READ_ENTER(&ipf_auth);
 387                 fr_authstats.fas_faelist = fae_list;
 388                 RWLOCK_EXIT(&ipf_auth);
 389                 error = IWCOPYPTR((char *)&fr_authstats, data,
 390                                    sizeof(fr_authstats));
 391                 break;
 392         case SIOCAUTHW:
 393                 if (!(mode & FWRITE)) {
 394                         error = EPERM;
 395                         break;
 396                 }
 397 fr_authioctlloop:
 398                 READ_ENTER(&ipf_auth);
 399                 if ((fr_authnext != fr_authend) && fr_authpkts[fr_authnext]) {
 400                         error = IWCOPYPTR((char *)&fr_auth[fr_authnext], data,
 401                                           sizeof(frauth_t));
 402                         RWLOCK_EXIT(&ipf_auth);
 403                         if (error)
 404                                 break;
 405                         WRITE_ENTER(&ipf_auth);
 406                         SPL_NET(s);
 407                         fr_authnext++;
 408                         if (fr_authnext == FR_NUMAUTH)
 409                                 fr_authnext = 0;
 410                         SPL_X(s);
 411                         RWLOCK_EXIT(&ipf_auth);
 412                         return 0;
 413                 }
 414 #ifdef  _KERNEL
 415 # if    SOLARIS
 416                 mutex_enter(&ipf_authmx);
 417                 if (!cv_wait_sig(&ipfauthwait, &ipf_authmx)) {
 418                         mutex_exit(&ipf_authmx);
 419                         return EINTR;
 420                 }
 421                 mutex_exit(&ipf_authmx);
 422 # else
 423                 error = SLEEP(&fr_authnext, "fr_authnext");
 424 # endif
 425 #endif
 426                 RWLOCK_EXIT(&ipf_auth);
 427                 if (!error)
 428                         goto fr_authioctlloop;
 429                 break;
 430         case SIOCAUTHR:
 431                 if (!(mode & FWRITE)) {
 432                         error = EPERM;
 433                         break;
 434                 }
 435                 error = IRCOPYPTR(data, (caddr_t)&auth, sizeof(auth));
 436                 if (error)
 437                         return error;
 438                 WRITE_ENTER(&ipf_auth);
 439                 SPL_NET(s);
 440                 i = au->fra_index;
 441                 fra = fr_auth + i;
 442                 if ((i < 0) || (i > FR_NUMAUTH) ||
 443                     (fra->fra_info.fin_id != au->fra_info.fin_id)) {
 444                         SPL_X(s);
 445                         RWLOCK_EXIT(&ipf_auth);
 446                         return EINVAL;
 447                 }
 448                 m = fr_authpkts[i];
 449                 fra->fra_index = -2;
 450                 fra->fra_pass = au->fra_pass;
 451                 fr_authpkts[i] = NULL;
 452                 RWLOCK_EXIT(&ipf_auth);
 453 #ifdef  _KERNEL
 454                 if (m && au->fra_info.fin_out) {
 455 # if SOLARIS
 456                         error = fr_qout(fra->fra_q, m);
 457 # else /* SOLARIS */
 458                         struct route ro;
 459
 460                         bzero((char *)&ro, sizeof(ro));
 461 #  if ((_BSDI_VERSION >= 199802) && (_BSDI_VERSION < 200005)) || \
 462        defined(__OpenBSD__)
 463                         error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL,
 464                                           NULL);
 465 #  else
 466                         error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL);
 467 #  endif
 468                         if (ro.ro_rt) {
 469                                 RTFREE(ro.ro_rt);
 470                         }
 471 # endif /* SOLARIS */
 472                         if (error)
 473                                 fr_authstats.fas_sendfail++;
 474                         else
 475                                 fr_authstats.fas_sendok++;
 476                 } else if (m) {
 477 # if SOLARIS
 478                         error = fr_qin(fra->fra_q, m);
 479 # else /* SOLARIS */
 480                         if (! IF_HANDOFF(&ipintrq, m, NULL))
 481                                 error = ENOBUFS;
 482                         else
 483                                 schednetisr(NETISR_IP);
 484 # endif /* SOLARIS */
 485                         if (error)
 486                                 fr_authstats.fas_quefail++;
 487                         else
 488                                 fr_authstats.fas_queok++;
 489                 } else
 490                         error = EINVAL;
 491 # if SOLARIS
 492                 if (error)
 493                         error = EINVAL;
 494 # else
 495                 /*
 496                  * If we experience an error which will result in the packet
 497                  * not being processed, make sure we advance to the next one.
 498                  */
 499                 if (error == ENOBUFS) {
 500                         fr_authused--;
 501                         fra->fra_index = -1;
 502                         fra->fra_pass = 0;
 503                         if (i == fr_authstart) {
 504                                 while (fra->fra_index == -1) {
 505                                         i++;
 506                                         if (i == FR_NUMAUTH)
 507                                                 i = 0;
 508                                         fr_authstart = i;
 509                                         if (i == fr_authend)
 510                                                 break;
 511                                 }
 512                                 if (fr_authstart == fr_authend) {
 513                                         fr_authnext = 0;
 514                                         fr_authstart = fr_authend = 0;
 515                                 }
 516                         }
 517                 }
 518 # endif
 519 #endif /* _KERNEL */
 520                 SPL_X(s);
 521                 break;
 522         default :
 523                 error = EINVAL;
 524                 break;
 525         }
 526         return error;
 527 }
 528
 529
 530 #ifdef  _KERNEL
 531 /*
 532  * Free all network buffer memory used to keep saved packets.
 533  */
 534 void fr_authunload()
 535 {
 536         register int i;
 537         register frauthent_t *fae, **faep;
 538         frentry_t *fr, **frp;
 539         mb_t *m;
 540
 541         WRITE_ENTER(&ipf_auth);
 542         for (i = 0; i < FR_NUMAUTH; i++) {
 543                 if ((m = fr_authpkts[i])) {
 544                         FREE_MB_T(m);
 545                         fr_authpkts[i] = NULL;
 546                         fr_auth[i].fra_index = -1;
 547                 }
 548         }
 549
 550
 551         for (faep = &fae_list; (fae = *faep); ) {
 552                 *faep = fae->fae_next;
 553                 KFREE(fae);
 554         }
 555         ipauth = NULL;
 556         RWLOCK_EXIT(&ipf_auth);
 557
 558         if (fr_authlist) {
 559                 /*
 560                  * We *MuST* reget ipf_auth because otherwise we won't get the
 561                  * locks in the right order and risk deadlock.
 562                  * We need ipf_mutex here to prevent a rule from using it
 563                  * inside fr_check().
 564                  */
 565                 WRITE_ENTER(&ipf_mutex);
 566                 WRITE_ENTER(&ipf_auth);
 567                 for (frp = &fr_authlist; (fr = *frp); ) {
 568                         if (fr->fr_ref == 1) {
 569                                 *frp = fr->fr_next;
 570                                 KFREE(fr);
 571                         } else
 572                                 frp = &fr->fr_next;
 573                 }
 574                 RWLOCK_EXIT(&ipf_auth);
 575                 RWLOCK_EXIT(&ipf_mutex);
 576         }
 577 }
 578
 579
 580 /*
 581  * Slowly expire held auth records.  Timeouts are set
 582  * in expectation of this being called twice per second.
 583  */
 584 void fr_authexpire()
 585 {
 586         register int i;
 587         register frauth_t *fra;
 588         register frauthent_t *fae, **faep;
 589         register frentry_t *fr, **frp;
 590         mb_t *m;
 591 #if !SOLARIS
 592         int s;
 593 #endif
 594
 595         if (fr_auth_lock)
 596                 return;
 597
 598         SPL_NET(s);
 599         WRITE_ENTER(&ipf_auth);
 600         for (i = 0, fra = fr_auth; i < FR_NUMAUTH; i++, fra++) {
 601                 if ((!--fra->fra_age) && (m = fr_authpkts[i])) {
 602                         FREE_MB_T(m);
 603                         fr_authpkts[i] = NULL;
 604                         fr_auth[i].fra_index = -1;
 605                         fr_authstats.fas_expire++;
 606                         fr_authused--;
 607                 }
 608         }
 609
 610         for (faep = &fae_list; (fae = *faep); ) {
 611                 if (!--fae->fae_age) {
 612                         *faep = fae->fae_next;
 613                         KFREE(fae);
 614                         fr_authstats.fas_expire++;
 615                 } else
 616                         faep = &fae->fae_next;
 617         }
 618         ipauth = &fae_list->fae_fr;
 619
 620         for (frp = &fr_authlist; (fr = *frp); ) {
 621                 if (fr->fr_ref == 1) {
 622                         *frp = fr->fr_next;
 623                         KFREE(fr);
 624                 } else
 625                         frp = &fr->fr_next;
 626         }
 627         RWLOCK_EXIT(&ipf_auth);
 628         SPL_X(s);
 629 }
 630 #endif