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  * @(#)$Id: ip_auth.c,v 2.11.2.20 2002/06/04 14:40:42 darrenr Exp $
   7  * $FreeBSD: src/sys/contrib/ipfilter/netinet/ip_auth.c,v 1.21.2.7 2003/03/01 03:55:54 darrenr Exp $
   8  * $DragonFly: src/sys/contrib/ipfilter/netinet/ip_auth.c,v 1.3 2003/07/26 14:07:18 rob Exp $
   9  */
  10 #if defined(__sgi) && (IRIX > 602)
  11 # include <sys/ptimers.h>
  12 #endif
  13 #include <sys/errno.h>
  14 #include <sys/types.h>
  15 #include <sys/param.h>
  16 #include <sys/time.h>
  17 #include <sys/file.h>
  18 #if !defined(_KERNEL) && !defined(KERNEL)
  19 # include <stdio.h>
  20 # include <stdlib.h>
  21 # include <string.h>
  22 #endif
  23 #if (defined(KERNEL) || defined(_KERNEL)) && (__FreeBSD_version >= 220000)
  24 # include <sys/filio.h>
  25 # include <sys/fcntl.h>
  26 #else
  27 # include <sys/ioctl.h>
  28 #endif
  29 #ifndef linux
  30 # include <sys/protosw.h>
  31 #endif
  32 #include <sys/socket.h>
  33 #if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux)
  34 # include <sys/systm.h>
  35 #endif
  36 #if !defined(__SVR4) && !defined(__svr4__)
  37 # ifndef linux
  38 #  include <sys/mbuf.h>
  39 # endif
  40 #else
  41 # include <sys/filio.h>
  42 # include <sys/byteorder.h>
  43 # ifdef _KERNEL
  44 #  include <sys/dditypes.h>
  45 # endif
  46 # include <sys/stream.h>
  47 # include <sys/kmem.h>
  48 #endif
  49 #if (_BSDI_VERSION >= 199802) || (__FreeBSD_version >= 400000)
  50 # include <sys/queue.h>
  51 #endif
  52 #if defined(__NetBSD__) || defined(__OpenBSD__) || defined(bsdi)
  53 # include <machine/cpu.h>
  54 #endif
  55 #include <net/if.h>
  56 #ifdef sun
  57 # include <net/af.h>
  58 #endif
  59 #include <net/route.h>
  60 #include <netinet/in.h>
  61 #include <netinet/in_systm.h>
  62 #include <netinet/ip.h>
  63 #ifndef KERNEL
  64 # define        KERNEL
  65 # define        NOT_KERNEL
  66 #endif
  67 #ifndef linux
  68 # include <netinet/ip_var.h>
  69 #endif
  70 #ifdef  NOT_KERNEL
  71 # undef KERNEL
  72 #endif
  73 #ifdef __sgi
  74 # ifdef IFF_DRVRLOCK /* IRIX6 */
  75 #  include <sys/hashing.h>
  76 # endif
  77 #endif
  78 #include <netinet/tcp.h>
  79 #if defined(__sgi) && !defined(IFF_DRVRLOCK) /* IRIX < 6 */
  80 extern struct ifqueue   ipintrq;                /* ip packet input queue */
  81 #else
  82 # ifndef linux
  83 #  if __FreeBSD_version >= 300000
  84 #   include <net/if_var.h>
  85 #  endif
  86 #  include <netinet/in_var.h>
  87 #  include <netinet/tcp_fsm.h>
  88 # endif
  89 #endif
  90 #include <netinet/udp.h>
  91 #include <netinet/ip_icmp.h>
  92 #include "netinet/ip_compat.h"
  93 #include <netinet/tcpip.h>
  94 #include "netinet/ip_fil.h"
  95 #include "netinet/ip_auth.h"
  96 #if !SOLARIS && !defined(linux)
  97 # include <net/netisr.h>
  98 # ifdef __FreeBSD__
  99 #  include <machine/cpufunc.h>
 100 # endif
 101 #endif
 102 #if (__FreeBSD_version >= 300000)
 103 # include <sys/malloc.h>
 104 # if (defined(_KERNEL) || defined(KERNEL)) && !defined(IPFILTER_LKM)
 105 #  include <sys/libkern.h>
 106 #  include <sys/systm.h>
 107 # endif
 108 #endif
 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                 u_short bo;
 281
 282                 bo = ip->ip_len;
 283                 ip->ip_len = htons(bo);
 284                 bo = ip->ip_off;
 285                 ip->ip_off = htons(bo);
 286         }
 287 # endif
 288         m->b_rptr -= qif->qf_off;
 289         fr_authpkts[i] = *(mblk_t **)fin->fin_mp;
 290         fra->fra_q = qif->qf_q;
 291         cv_signal(&ipfauthwait);
 292 #else
 293 # if defined(BSD) && !defined(sparc) && (BSD >= 199306)
 294         if (fin->fin_out == 0) {
 295                 ip->ip_len = htons(ip->ip_len);
 296                 ip->ip_off = htons(ip->ip_off);
 297         }
 298 # endif
 299         fr_authpkts[i] = m;
 300         WAKEUP(&fr_authnext);
 301 #endif
 302         return 1;
 303 }
 304
 305
 306 int fr_auth_ioctl(data, mode, cmd)
 307 caddr_t data;
 308 int mode;
 309 #if defined(__NetBSD__) || defined(__OpenBSD__) || (__FreeBSD_version >= 300003)
 310 u_long cmd;
 311 #else
 312 int cmd;
 313 #endif
 314 {
 315         mb_t *m;
 316 #if defined(_KERNEL) && !SOLARIS
 317         struct ifqueue *ifq;
 318         int s;
 319 #endif
 320         frauth_t auth, *au = &auth, *fra;
 321         int i, error = 0;
 322
 323         switch (cmd)
 324         {
 325         case SIOCSTLCK :
 326                 if (!(mode & FWRITE)) {
 327                         error = EPERM;
 328                         break;
 329                 }
 330                 error = fr_lock(data, &fr_auth_lock);
 331                 break;
 332         case SIOCINIFR :
 333         case SIOCRMIFR :
 334         case SIOCADIFR :
 335                 error = EINVAL;
 336                 break;
 337         case SIOCINAFR :
 338                 error = EINVAL;
 339                 break;
 340         case SIOCRMAFR :
 341         case SIOCADAFR :
 342                 /* These commands go via request to fr_preauthcmd */
 343                 error = EINVAL;
 344                 break;
 345         case SIOCATHST:
 346                 fr_authstats.fas_faelist = fae_list;
 347                 error = IWCOPYPTR((char *)&fr_authstats, data,
 348                                    sizeof(fr_authstats));
 349                 break;
 350         case SIOCAUTHW:
 351                 if (!(mode & FWRITE)) {
 352                         error = EPERM;
 353                         break;
 354                 }
 355 fr_authioctlloop:
 356                 READ_ENTER(&ipf_auth);
 357                 if ((fr_authnext != fr_authend) && fr_authpkts[fr_authnext]) {
 358                         error = IWCOPYPTR((char *)&fr_auth[fr_authnext], data,
 359                                           sizeof(frauth_t));
 360                         RWLOCK_EXIT(&ipf_auth);
 361                         if (error)
 362                                 break;
 363                         WRITE_ENTER(&ipf_auth);
 364                         SPL_NET(s);
 365                         fr_authnext++;
 366                         if (fr_authnext == FR_NUMAUTH)
 367                                 fr_authnext = 0;
 368                         SPL_X(s);
 369                         RWLOCK_EXIT(&ipf_auth);
 370                         return 0;
 371                 }
 372                 RWLOCK_EXIT(&ipf_auth);
 373 #ifdef  _KERNEL
 374 # if    SOLARIS
 375                 mutex_enter(&ipf_authmx);
 376                 if (!cv_wait_sig(&ipfauthwait, &ipf_authmx)) {
 377                         mutex_exit(&ipf_authmx);
 378                         return EINTR;
 379                 }
 380                 mutex_exit(&ipf_authmx);
 381 # else
 382                 error = SLEEP(&fr_authnext, "fr_authnext");
 383 # endif
 384 #endif
 385                 if (!error)
 386                         goto fr_authioctlloop;
 387                 break;
 388         case SIOCAUTHR:
 389                 if (!(mode & FWRITE)) {
 390                         error = EPERM;
 391                         break;
 392                 }
 393                 error = IRCOPYPTR(data, (caddr_t)&auth, sizeof(auth));
 394                 if (error)
 395                         return error;
 396                 WRITE_ENTER(&ipf_auth);
 397                 SPL_NET(s);
 398                 i = au->fra_index;
 399                 fra = fr_auth + i;
 400                 if ((i < 0) || (i > FR_NUMAUTH) ||
 401                     (fra->fra_info.fin_id != au->fra_info.fin_id)) {
 402                         SPL_X(s);
 403                         RWLOCK_EXIT(&ipf_auth);
 404                         return EINVAL;
 405                 }
 406                 m = fr_authpkts[i];
 407                 fra->fra_index = -2;
 408                 fra->fra_pass = au->fra_pass;
 409                 fr_authpkts[i] = NULL;
 410                 RWLOCK_EXIT(&ipf_auth);
 411 #ifdef  _KERNEL
 412                 if (m && au->fra_info.fin_out) {
 413 # if SOLARIS
 414                         error = (fr_qout(fra->fra_q, m) == 0) ? EINVAL : 0;
 415 # else /* SOLARIS */
 416                         struct route ro;
 417
 418                         bzero((char *)&ro, sizeof(ro));
 419 #  if ((_BSDI_VERSION >= 199802) && (_BSDI_VERSION < 200005)) || \
 420        defined(__OpenBSD__) || (defined(IRIX) && (IRIX >= 605)) || \
 421        (__FreeBSD_version >= 470102)
 422                         error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL,
 423                                           NULL);
 424 #  else
 425                         error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL);
 426 #  endif
 427                         if (ro.ro_rt) {
 428                                 RTFREE(ro.ro_rt);
 429                         }
 430 # endif /* SOLARIS */
 431                         if (error)
 432                                 fr_authstats.fas_sendfail++;
 433                         else
 434                                 fr_authstats.fas_sendok++;
 435                 } else if (m) {
 436 # if SOLARIS
 437                         error = (fr_qin(fra->fra_q, m) == 0) ? EINVAL : 0;
 438 # else /* SOLARIS */
 439                         ifq = &ipintrq;
 440                         if (IF_QFULL(ifq)) {
 441                                 IF_DROP(ifq);
 442                                 m_freem(m);
 443                                 error = ENOBUFS;
 444                         } else {
 445                                 IF_ENQUEUE(ifq, m);
 446 #  if IRIX < 605
 447                                 schednetisr(NETISR_IP);
 448 #  endif
 449                         }
 450 # endif /* SOLARIS */
 451                         if (error)
 452                                 fr_authstats.fas_quefail++;
 453                         else
 454                                 fr_authstats.fas_queok++;
 455                 } else
 456                         error = EINVAL;
 457 # if SOLARIS
 458                 if (error)
 459                         error = EINVAL;
 460 # else
 461                 /*
 462                  * If we experience an error which will result in the packet
 463                  * not being processed, make sure we advance to the next one.
 464                  */
 465                 if (error == ENOBUFS) {
 466                         fr_authused--;
 467                         fra->fra_index = -1;
 468                         fra->fra_pass = 0;
 469                         if (i == fr_authstart) {
 470                                 while (fra->fra_index == -1) {
 471                                         i++;
 472                                         if (i == FR_NUMAUTH)
 473                                                 i = 0;
 474                                         fr_authstart = i;
 475                                         if (i == fr_authend)
 476                                                 break;
 477                                 }
 478                                 if (fr_authstart == fr_authend) {
 479                                         fr_authnext = 0;
 480                                         fr_authstart = fr_authend = 0;
 481                                 }
 482                         }
 483                 }
 484 # endif
 485 #endif /* _KERNEL */
 486                 SPL_X(s);
 487                 break;
 488         default :
 489                 error = EINVAL;
 490                 break;
 491         }
 492         return error;
 493 }
 494
 495
 496 /*
 497  * Free all network buffer memory used to keep saved packets.
 498  */
 499 void fr_authunload()
 500 {
 501         int i;
 502         frauthent_t *fae, **faep;
 503         frentry_t *fr, **frp;
 504         mb_t *m;
 505
 506         WRITE_ENTER(&ipf_auth);
 507         for (i = 0; i < FR_NUMAUTH; i++) {
 508                 if ((m = fr_authpkts[i])) {
 509                         FREE_MB_T(m);
 510                         fr_authpkts[i] = NULL;
 511                         fr_auth[i].fra_index = -1;
 512                 }
 513         }
 514
 515
 516         for (faep = &fae_list; (fae = *faep); ) {
 517                 *faep = fae->fae_next;
 518                 KFREE(fae);
 519         }
 520         ipauth = NULL;
 521         RWLOCK_EXIT(&ipf_auth);
 522
 523         if (fr_authlist) {
 524                 /*
 525                  * We *MuST* reget ipf_auth because otherwise we won't get the
 526                  * locks in the right order and risk deadlock.
 527                  * We need ipf_mutex here to prevent a rule from using it
 528                  * inside fr_check().
 529                  */
 530                 WRITE_ENTER(&ipf_mutex);
 531                 WRITE_ENTER(&ipf_auth);
 532                 for (frp = &fr_authlist; (fr = *frp); ) {
 533                         if (fr->fr_ref == 1) {
 534                                 *frp = fr->fr_next;
 535                                 KFREE(fr);
 536                         } else
 537                                 frp = &fr->fr_next;
 538                 }
 539                 RWLOCK_EXIT(&ipf_auth);
 540                 RWLOCK_EXIT(&ipf_mutex);
 541         }
 542 }
 543
 544
 545 /*
 546  * Slowly expire held auth records.  Timeouts are set
 547  * in expectation of this being called twice per second.
 548  */
 549 void fr_authexpire()
 550 {
 551         int i;
 552         frauth_t *fra;
 553         frauthent_t *fae, **faep;
 554         frentry_t *fr, **frp;
 555         mb_t *m;
 556 #if !SOLARIS && defined(_KERNEL)
 557         int s;
 558 #endif
 559
 560         if (fr_auth_lock)
 561                 return;
 562
 563         SPL_NET(s);
 564         WRITE_ENTER(&ipf_auth);
 565         for (i = 0, fra = fr_auth; i < FR_NUMAUTH; i++, fra++) {
 566                 if ((!--fra->fra_age) && (m = fr_authpkts[i])) {
 567                         FREE_MB_T(m);
 568                         fr_authpkts[i] = NULL;
 569                         fr_auth[i].fra_index = -1;
 570                         fr_authstats.fas_expire++;
 571                         fr_authused--;
 572                 }
 573         }
 574
 575         for (faep = &fae_list; (fae = *faep); ) {
 576                 if (!--fae->fae_age) {
 577                         *faep = fae->fae_next;
 578                         KFREE(fae);
 579                         fr_authstats.fas_expire++;
 580                 } else
 581                         faep = &fae->fae_next;
 582         }
 583         if (fae_list != NULL)
 584                 ipauth = &fae_list->fae_fr;
 585         else
 586                 ipauth = NULL;
 587
 588         for (frp = &fr_authlist; (fr = *frp); ) {
 589                 if (fr->fr_ref == 1) {
 590                         *frp = fr->fr_next;
 591                         KFREE(fr);
 592                 } else
 593                         frp = &fr->fr_next;
 594         }
 595         RWLOCK_EXIT(&ipf_auth);
 596         SPL_X(s);
 597 }
 598
 599 int fr_preauthcmd(cmd, fr, frptr)
 600 #if defined(__NetBSD__) || defined(__OpenBSD__) || \
 601         (_BSDI_VERSION >= 199701) || (__FreeBSD_version >= 300000)
 602 u_long cmd;
 603 #else
 604 int cmd;
 605 #endif
 606 frentry_t *fr, **frptr;
 607 {
 608         frauthent_t *fae, **faep;
 609         int error = 0;
 610 #if defined(KERNEL) && !SOLARIS
 611         int s;
 612 #endif
 613
 614         if ((cmd != SIOCADAFR) && (cmd != SIOCRMAFR)) {
 615                 /* Should not happen */
 616                 printf("fr_preauthcmd called with bad cmd 0x%lx", (u_long)cmd);
 617                 return EIO;
 618         }
 619
 620         for (faep = &fae_list; (fae = *faep); )
 621                 if (&fae->fae_fr == fr)
 622                         break;
 623                 else
 624                         faep = &fae->fae_next;
 625         if (cmd == SIOCRMAFR) {
 626                 if (!fr || !frptr)
 627                         error = EINVAL;
 628                 else if (!fae)
 629                         error = ESRCH;
 630                 else {
 631                         WRITE_ENTER(&ipf_auth);
 632                         SPL_NET(s);
 633                         *faep = fae->fae_next;
 634                         *frptr = fr->fr_next;
 635                         SPL_X(s);
 636                         RWLOCK_EXIT(&ipf_auth);
 637                         KFREE(fae);
 638                 }
 639         } else if (fr && frptr) {
 640                 KMALLOC(fae, frauthent_t *);
 641                 if (fae != NULL) {
 642                         bcopy((char *)fr, (char *)&fae->fae_fr,
 643                               sizeof(*fr));
 644                         WRITE_ENTER(&ipf_auth);
 645                         SPL_NET(s);
 646                         fae->fae_age = fr_defaultauthage;
 647                         fae->fae_fr.fr_hits = 0;
 648                         fae->fae_fr.fr_next = *frptr;
 649                         *frptr = &fae->fae_fr;
 650                         fae->fae_next = *faep;
 651                         *faep = fae;
 652                         ipauth = &fae_list->fae_fr;
 653                         SPL_X(s);
 654                         RWLOCK_EXIT(&ipf_auth);
 655                 } else
 656                         error = ENOMEM;
 657         } else
 658                 error = EINVAL;
 659         return error;
 660 }