usr.sbin/rtadvd/rrenum.c

   1 /*
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/ioctl.h>
  34 #include <sys/socket.h>
  35 #include <sys/sysctl.h>
  36
  37 #include <net/if.h>
  38 #include <net/if_var.h>
  39 #include <net/route.h>
  40 #include <netinet/in.h>
  41 #include <netinet/in_var.h>
  42 #include <netinet/icmp6.h>
  43
  44 #include <arpa/inet.h>
  45
  46 #include <errno.h>
  47 #include <string.h>
  48 #include <stdlib.h>
  49 #include <syslog.h>
  50 #include "rrenum.h"
  51 #include "if.h"
  52
  53 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  54         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  55 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  56         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  57
  58 struct rr_operation {
  59         u_long  rro_seqnum;
  60         u_long  rro_segnum_bits[8];
  61 };
  62
  63 static struct   rr_operation rro;
  64 static int      rr_rcvifindex;
  65 static int      rrcmd2pco[4] = {0,
  66                            SIOCAIFPREFIX_IN6,
  67                            SIOCCIFPREFIX_IN6,
  68                            SIOCSGIFPREFIX_IN6
  69 };
  70 static int      s;
  71
  72 /*
  73  * Check validity of a Prefix Control Operation(PCO).
  74  * Return 0 on success, 1 on failure.
  75  */
  76 static int
  77 rr_pco_check(int len, struct rr_pco_match *rpm)
  78 {
  79         struct rr_pco_use *rpu, *rpulim;
  80         int checklen;
  81
  82         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  83         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  84             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  85                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  86                        __FUNCTION__, rpm->rpm_len);
  87                 return 1;
  88         }
  89         /* rpm->rpm_code must be valid value */
  90         switch(rpm->rpm_code) {
  91         case RPM_PCO_ADD:
  92         case RPM_PCO_CHANGE:
  93         case RPM_PCO_SETGLOBAL:
  94                 break;
  95         default:
  96                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __FUNCTION__,
  97                        rpm->rpm_code);
  98                 return 1;
  99         }
 100         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 101         if (rpm->rpm_matchlen > 128) {
 102                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 103                        __FUNCTION__, rpm->rpm_matchlen);
 104                 return 1;
 105         }
 106
 107         /*
 108          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 109          * between 0 and 128 inclusive
 110          */
 111         for (rpu = (struct rr_pco_use *)(rpm + 1),
 112              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 113              rpu < rpulim;
 114              rpu += 1) {
 115                 checklen = rpu->rpu_uselen;
 116                 checklen += rpu->rpu_keeplen;
 117                 /*
 118                  * omit these check, because either of rpu_uselen
 119                  * and rpu_keeplen is unsigned char
 120                  *  (128 > rpu_uselen > 0)
 121                  *  (128 > rpu_keeplen > 0)
 122                  *  (rpu_uselen + rpu_keeplen > 0)
 123                  */
 124                 if (checklen > 128) {
 125                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 126                                " rpu_keeplen %d is %d(over 128)",
 127                                __FUNCTION__, rpu->rpu_uselen,
 128                                rpu->rpu_keeplen,
 129                                rpu->rpu_uselen + rpu->rpu_keeplen);
 130                         return 1;
 131                 }
 132         }
 133         return 0;
 134 }
 135
 136 static void
 137 do_use_prefix(int len, struct rr_pco_match *rpm, struct in6_rrenumreq *irr) {
 138         struct rr_pco_use *rpu, *rpulim;
 139
 140         rpu = (struct rr_pco_use *)(rpm + 1);
 141         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 142
 143         if (rpu == rpulim) {
 144                 if (rpm->rpm_code == RPM_PCO_ADD)
 145                         return;
 146
 147                 irr->irr_u_uselen = 0;
 148                 irr->irr_u_keeplen = 0;
 149                 irr->irr_raf_mask_onlink = 0;
 150                 irr->irr_raf_mask_auto = 0;
 151                 irr->irr_vltime = 0;
 152                 irr->irr_pltime = 0;
 153                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 154                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 155                 irr->irr_useprefix.sin6_family = 0;
 156                 irr->irr_useprefix.sin6_addr = in6addr_any;
 157                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 158                     errno != EADDRNOTAVAIL)
 159                         syslog(LOG_ERR, "<%s> ioctl: %s", __FUNCTION__,
 160                                strerror(errno));
 161                 return;
 162         }
 163
 164         for (rpu = (struct rr_pco_use *)(rpm + 1),
 165              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 166              rpu < rpulim;
 167              rpu += 1) {
 168                 /* init in6_rrenumreq fields */
 169                 irr->irr_u_uselen = rpu->rpu_uselen;
 170                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 171                 irr->irr_raf_mask_onlink =
 172                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 173                 irr->irr_raf_mask_auto =
 174                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 175                 irr->irr_vltime = rpu->rpu_vltime;
 176                 irr->irr_pltime = rpu->rpu_pltime;
 177                 irr->irr_raf_onlink =
 178                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 179                 irr->irr_raf_auto =
 180                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 181                 irr->irr_rrf_decrvalid =
 182                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME);
 183                 irr->irr_rrf_decrprefd =
 184                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME);
 185                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 186                 irr->irr_useprefix.sin6_family = AF_INET6;
 187                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 188
 189                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 190                     errno != EADDRNOTAVAIL)
 191                         syslog(LOG_ERR, "<%s> ioctl: %s", __FUNCTION__,
 192                                strerror(errno));
 193         }
 194 }
 195
 196 /*
 197  * process a Prefix Control Operation(PCO).
 198  * return 0 on success, 1 on failure
 199  */
 200 static int
 201 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 202 {
 203         int ifindex = 0;
 204         struct in6_rrenumreq irr;
 205
 206         if ((rr_pco_check(len, rpm) != NULL))
 207                 return 1;
 208
 209         if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 210                 syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
 211                        strerror(errno));
 212                 exit(1);
 213         }
 214
 215         memset(&irr, 0, sizeof(irr));
 216         irr.irr_origin = PR_ORIG_RR;
 217         irr.irr_m_len = rpm->rpm_matchlen;
 218         irr.irr_m_minlen = rpm->rpm_minlen;
 219         irr.irr_m_maxlen = rpm->rpm_maxlen;
 220         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 221         irr.irr_matchprefix.sin6_family = AF_INET6;
 222         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 223
 224         while (if_indextoname(++ifindex, irr.irr_name)) {
 225                 /*
 226                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
 227                  * the interface is not applied
 228                  */
 229                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 230                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
 231                         continue;
 232                 /* TODO: interface scope check */
 233                 do_use_prefix(len, rpm, &irr);
 234         }
 235         if (errno == ENXIO)
 236                 return 0;
 237         else if (errno) {
 238                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __FUNCTION__,
 239                        strerror(errno));
 240                 return 1;
 241         }
 242         return 0;
 243 }
 244
 245 /*
 246  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 247  * Router Renumbering Command packet.
 248  * return 0 on success, 1 on failure
 249  */
 250 static int
 251 do_rr(int len, struct icmp6_router_renum *rr)
 252 {
 253         struct rr_pco_match *rpm;
 254         char *cp, *lim;
 255
 256         lim = (char *)rr + len;
 257         cp = (char *)(rr + 1);
 258         len -= sizeof(struct icmp6_router_renum);
 259
 260         /* get iflist block from kernel again, to get up-to-date information */
 261         init_iflist();
 262
 263         while (cp < lim) {
 264                 int rpmlen;
 265
 266                 rpm = (struct rr_pco_match *)cp;
 267                 if (len < sizeof(struct rr_pco_match)) {
 268                     tooshort:
 269                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 270                                "gabage at end of pkt?", __FUNCTION__, len);
 271                         return 1;
 272                 }
 273                 rpmlen = rpm->rpm_len << 3;
 274                 if (len < rpmlen)
 275                         goto tooshort;
 276
 277                 if (do_pco(rr, rpmlen, rpm)) {
 278                         syslog(LOG_WARNING, "<%s> invalid PCO", __FUNCTION__);
 279                         goto next;
 280                 }
 281
 282             next:
 283                 cp += rpmlen;
 284                 len -= rpmlen;
 285         }
 286
 287         return 0;
 288 }
 289
 290 /*
 291  * check validity of a router renumbering command packet
 292  * return 0 on success, 1 on failure
 293  */
 294 static int
 295 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 296                  struct in6_addr *dst)
 297 {
 298         u_char ntopbuf[INET6_ADDRSTRLEN];
 299
 300         /* omit rr minimal length check. hope kernel have done it. */
 301         /* rr_command length check */
 302         if (len < (sizeof(struct icmp6_router_renum) +
 303                    sizeof(struct rr_pco_match))) {
 304                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 305                        __FUNCTION__, len);
 306                 return 1;
 307         }
 308
 309         /* destination check. only for multicast. omit unicast check. */
 310         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 311             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 312                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 313                        __FUNCTION__,
 314                        inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
 315                 return 1;
 316         }
 317
 318         /* seqnum and segnum check */
 319         if (rro.rro_seqnum > rr->rr_seqnum) {
 320                 syslog(LOG_WARNING,
 321                        "<%s> rcvd old seqnum %d from %s",
 322                        __FUNCTION__, (u_int32_t)ntohl(rr->rr_seqnum),
 323                        inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
 324                 return 1;
 325         }
 326         if (rro.rro_seqnum == rr->rr_seqnum &&
 327             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 328             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 329                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 330                         syslog(LOG_WARNING,
 331                                "<%s> rcvd duped segnum %d from %s",
 332                                __FUNCTION__, rr->rr_segnum,
 333                                inet_ntop(AF_INET6, from, ntopbuf,
 334                                          INET6_ADDRSTRLEN));
 335                 return 0;
 336         }
 337
 338         /* update seqnum */
 339         if (rro.rro_seqnum != rr->rr_seqnum) {
 340                 /* then must be "<" */
 341
 342                 /* init rro_segnum_bits */
 343                 memset(rro.rro_segnum_bits, 0,
 344                        sizeof(rro.rro_segnum_bits));
 345         }
 346         rro.rro_seqnum = rr->rr_seqnum;
 347
 348         return 0;
 349 }
 350
 351 static void
 352 rr_command_input(int len, struct icmp6_router_renum *rr,
 353                  struct in6_addr *from, struct in6_addr *dst)
 354 {
 355         /* rr_command validity check */
 356         if (rr_command_check(len, rr, from, dst))
 357                 goto failed;
 358         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 359             ICMP6_RR_FLAGS_TEST)
 360                 return;
 361
 362         /* do router renumbering */
 363         if (do_rr(len, rr)) {
 364                 goto failed;
 365         }
 366
 367         /* update segnum */
 368         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 369
 370         return;
 371
 372     failed:
 373         syslog(LOG_ERR, "<%s> received RR was invalid", __FUNCTION__);
 374         return;
 375 }
 376
 377 void
 378 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 379          struct sockaddr_in6 *from, struct in6_addr *dst)
 380 {
 381         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 382
 383         syslog(LOG_DEBUG,
 384                "<%s> RR received from %s to %s on %s",
 385                __FUNCTION__,
 386                inet_ntop(AF_INET6, &from->sin6_addr,
 387                          ntopbuf[0], INET6_ADDRSTRLEN),
 388                inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 389                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 390
 391         rr_rcvifindex = pi->ipi6_ifindex;
 392
 393         /* TODO: some consistency check. */
 394
 395         switch (rr->rr_code) {
 396         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 397                 rr_command_input(len, rr, &from->sin6_addr, dst);
 398                 /* TODO: send reply msg */
 399                 break;
 400         case ICMP6_ROUTER_RENUMBERING_RESULT:
 401                 /* RESULT will be processed by rrenumd */
 402                 break;
 403         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 404                 /* TODO: sequence number reset */
 405                 break;
 406         default:
 407                 syslog(LOG_ERR, "<%s> received unknown code %d",
 408                        __FUNCTION__, rr->rr_code);
 409                 break;
 410
 411         }
 412
 413         return;
 414 }