usr.sbin/rtadvd/rrenum.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: rrenum.c,v 1.3 2000/05/16 13:34:14 itojun Exp $  */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/socket.h>
  36 #include <sys/sysctl.h>
  37
  38 #include <net/if.h>
  39 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
  40 #include <net/if_var.h>
  41 #endif /* __FreeBSD__ >= 3 */
  42 #include <net/route.h>
  43 #include <netinet/in.h>
  44 #include <netinet/in_var.h>
  45 #include <netinet/icmp6.h>
  46
  47 #include <arpa/inet.h>
  48
  49 #include <errno.h>
  50 #include <string.h>
  51 #include <stdlib.h>
  52 #include <syslog.h>
  53 #include "rrenum.h"
  54 #include "if.h"
  55
  56 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  57         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  58 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  59         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  60
  61 struct rr_operation {
  62         u_long  rro_seqnum;
  63         u_long  rro_segnum_bits[8];
  64 };
  65
  66 static struct rr_operation rro;
  67 static int rr_rcvifindex;
  68 static int rrcmd2pco[RPM_PCO_MAX] = {
  69         0,
  70         SIOCAIFPREFIX_IN6,
  71         SIOCCIFPREFIX_IN6,
  72         SIOCSGIFPREFIX_IN6
  73 };
  74 static int s = -1;
  75
  76 /*
  77  * Check validity of a Prefix Control Operation(PCO).
  78  * Return 0 on success, 1 on failure.
  79  */
  80 static int
  81 rr_pco_check(int len, struct rr_pco_match *rpm)
  82 {
  83         struct rr_pco_use *rpu, *rpulim;
  84         int checklen;
  85
  86         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  87         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  88             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  89                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  90                        __FUNCTION__, rpm->rpm_len);
  91                 return 1;
  92         }
  93         /* rpm->rpm_code must be valid value */
  94         switch(rpm->rpm_code) {
  95         case RPM_PCO_ADD:
  96         case RPM_PCO_CHANGE:
  97         case RPM_PCO_SETGLOBAL:
  98                 break;
  99         default:
 100                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __FUNCTION__,
 101                        rpm->rpm_code);
 102                 return 1;
 103         }
 104         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 105         if (rpm->rpm_matchlen > 128) {
 106                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 107                        __FUNCTION__, rpm->rpm_matchlen);
 108                 return 1;
 109         }
 110
 111         /*
 112          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 113          * between 0 and 128 inclusive
 114          */
 115         for (rpu = (struct rr_pco_use *)(rpm + 1),
 116              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 117              rpu < rpulim;
 118              rpu += 1) {
 119                 checklen = rpu->rpu_uselen;
 120                 checklen += rpu->rpu_keeplen;
 121                 /*
 122                  * omit these check, because either of rpu_uselen
 123                  * and rpu_keeplen is unsigned char
 124                  *  (128 > rpu_uselen > 0)
 125                  *  (128 > rpu_keeplen > 0)
 126                  *  (rpu_uselen + rpu_keeplen > 0)
 127                  */
 128                 if (checklen > 128) {
 129                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 130                                " rpu_keeplen %d is %d(over 128)",
 131                                __FUNCTION__, rpu->rpu_uselen,
 132                                rpu->rpu_keeplen,
 133                                rpu->rpu_uselen + rpu->rpu_keeplen);
 134                         return 1;
 135                 }
 136         }
 137         return 0;
 138 }
 139
 140 static void
 141 do_use_prefix(int len, struct rr_pco_match *rpm, struct in6_rrenumreq *irr) {
 142         struct rr_pco_use *rpu, *rpulim;
 143
 144         rpu = (struct rr_pco_use *)(rpm + 1);
 145         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 146
 147         if (rpu == rpulim) {
 148                 if (rpm->rpm_code == RPM_PCO_ADD)
 149                         return;
 150
 151                 irr->irr_u_uselen = 0;
 152                 irr->irr_u_keeplen = 0;
 153                 irr->irr_raf_mask_onlink = 0;
 154                 irr->irr_raf_mask_auto = 0;
 155                 irr->irr_vltime = 0;
 156                 irr->irr_pltime = 0;
 157                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 158                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 159                 irr->irr_useprefix.sin6_family = 0;
 160                 irr->irr_useprefix.sin6_addr = in6addr_any;
 161                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 162                     errno != EADDRNOTAVAIL)
 163                         syslog(LOG_ERR, "<%s> ioctl: %s", __FUNCTION__,
 164                                strerror(errno));
 165                 return;
 166         }
 167
 168         for (rpu = (struct rr_pco_use *)(rpm + 1),
 169              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 170              rpu < rpulim;
 171              rpu += 1) {
 172                 /* init in6_rrenumreq fields */
 173                 irr->irr_u_uselen = rpu->rpu_uselen;
 174                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 175                 irr->irr_raf_mask_onlink =
 176                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 177                 irr->irr_raf_mask_auto =
 178                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 179                 irr->irr_vltime = rpu->rpu_vltime;
 180                 irr->irr_pltime = rpu->rpu_pltime;
 181                 irr->irr_raf_onlink =
 182                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 183                 irr->irr_raf_auto =
 184                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 185                 irr->irr_rrf_decrvalid =
 186                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME);
 187                 irr->irr_rrf_decrprefd =
 188                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME);
 189                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 190                 irr->irr_useprefix.sin6_family = AF_INET6;
 191                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 192
 193                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 194                     errno != EADDRNOTAVAIL)
 195                         syslog(LOG_ERR, "<%s> ioctl: %s", __FUNCTION__,
 196                                strerror(errno));
 197         }
 198 }
 199
 200 /*
 201  * process a Prefix Control Operation(PCO).
 202  * return 0 on success, 1 on failure
 203  */
 204 static int
 205 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 206 {
 207         int ifindex = 0;
 208         struct in6_rrenumreq irr;
 209
 210         if ((rr_pco_check(len, rpm) != NULL))
 211                 return 1;
 212
 213         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 214                 syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
 215                        strerror(errno));
 216                 exit(1);
 217         }
 218
 219         memset(&irr, 0, sizeof(irr));
 220         irr.irr_origin = PR_ORIG_RR;
 221         irr.irr_m_len = rpm->rpm_matchlen;
 222         irr.irr_m_minlen = rpm->rpm_minlen;
 223         irr.irr_m_maxlen = rpm->rpm_maxlen;
 224         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 225         irr.irr_matchprefix.sin6_family = AF_INET6;
 226         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 227
 228         while (if_indextoname(++ifindex, irr.irr_name)) {
 229                 /*
 230                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
 231                  * the interface is not applied
 232                  */
 233                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 234                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
 235                         continue;
 236                 /* TODO: interface scope check */
 237                 do_use_prefix(len, rpm, &irr);
 238         }
 239         if (errno == ENXIO)
 240                 return 0;
 241         else if (errno) {
 242                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __FUNCTION__,
 243                        strerror(errno));
 244                 return 1;
 245         }
 246         return 0;
 247 }
 248
 249 /*
 250  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 251  * Router Renumbering Command packet.
 252  * return 0 on success, 1 on failure
 253  */
 254 static int
 255 do_rr(int len, struct icmp6_router_renum *rr)
 256 {
 257         struct rr_pco_match *rpm;
 258         char *cp, *lim;
 259
 260         lim = (char *)rr + len;
 261         cp = (char *)(rr + 1);
 262         len -= sizeof(struct icmp6_router_renum);
 263
 264         /* get iflist block from kernel again, to get up-to-date information */
 265         init_iflist();
 266
 267         while (cp < lim) {
 268                 int rpmlen;
 269
 270                 rpm = (struct rr_pco_match *)cp;
 271                 if (len < sizeof(struct rr_pco_match)) {
 272                     tooshort:
 273                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 274                                "gabage at end of pkt?", __FUNCTION__, len);
 275                         return 1;
 276                 }
 277                 rpmlen = rpm->rpm_len << 3;
 278                 if (len < rpmlen)
 279                         goto tooshort;
 280
 281                 if (do_pco(rr, rpmlen, rpm)) {
 282                         syslog(LOG_WARNING, "<%s> invalid PCO", __FUNCTION__);
 283                         goto next;
 284                 }
 285
 286             next:
 287                 cp += rpmlen;
 288                 len -= rpmlen;
 289         }
 290
 291         return 0;
 292 }
 293
 294 /*
 295  * check validity of a router renumbering command packet
 296  * return 0 on success, 1 on failure
 297  */
 298 static int
 299 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 300                  struct in6_addr *dst)
 301 {
 302         u_char ntopbuf[INET6_ADDRSTRLEN];
 303
 304         /* omit rr minimal length check. hope kernel have done it. */
 305         /* rr_command length check */
 306         if (len < (sizeof(struct icmp6_router_renum) +
 307                    sizeof(struct rr_pco_match))) {
 308                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 309                        __FUNCTION__, len);
 310                 return 1;
 311         }
 312
 313         /* destination check. only for multicast. omit unicast check. */
 314         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 315             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 316                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 317                        __FUNCTION__,
 318                        inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
 319                 return 1;
 320         }
 321
 322         /* seqnum and segnum check */
 323         if (rro.rro_seqnum > rr->rr_seqnum) {
 324                 syslog(LOG_WARNING,
 325                        "<%s> rcvd old seqnum %d from %s",
 326                        __FUNCTION__, (u_int32_t)ntohl(rr->rr_seqnum),
 327                        inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
 328                 return 1;
 329         }
 330         if (rro.rro_seqnum == rr->rr_seqnum &&
 331             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 332             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 333                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 334                         syslog(LOG_WARNING,
 335                                "<%s> rcvd duped segnum %d from %s",
 336                                __FUNCTION__, rr->rr_segnum,
 337                                inet_ntop(AF_INET6, from, ntopbuf,
 338                                          INET6_ADDRSTRLEN));
 339                 return 0;
 340         }
 341
 342         /* update seqnum */
 343         if (rro.rro_seqnum != rr->rr_seqnum) {
 344                 /* then must be "<" */
 345
 346                 /* init rro_segnum_bits */
 347                 memset(rro.rro_segnum_bits, 0,
 348                        sizeof(rro.rro_segnum_bits));
 349         }
 350         rro.rro_seqnum = rr->rr_seqnum;
 351
 352         return 0;
 353 }
 354
 355 static void
 356 rr_command_input(int len, struct icmp6_router_renum *rr,
 357                  struct in6_addr *from, struct in6_addr *dst)
 358 {
 359         /* rr_command validity check */
 360         if (rr_command_check(len, rr, from, dst))
 361                 goto failed;
 362         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 363             ICMP6_RR_FLAGS_TEST)
 364                 return;
 365
 366         /* do router renumbering */
 367         if (do_rr(len, rr)) {
 368                 goto failed;
 369         }
 370
 371         /* update segnum */
 372         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 373
 374         return;
 375
 376     failed:
 377         syslog(LOG_ERR, "<%s> received RR was invalid", __FUNCTION__);
 378         return;
 379 }
 380
 381 void
 382 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 383          struct sockaddr_in6 *from, struct in6_addr *dst)
 384 {
 385         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 386
 387         syslog(LOG_DEBUG,
 388                "<%s> RR received from %s to %s on %s",
 389                __FUNCTION__,
 390                inet_ntop(AF_INET6, &from->sin6_addr,
 391                          ntopbuf[0], INET6_ADDRSTRLEN),
 392                inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 393                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 394
 395         rr_rcvifindex = pi->ipi6_ifindex;
 396
 397         /* TODO: some consistency check. */
 398
 399         switch (rr->rr_code) {
 400         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 401                 rr_command_input(len, rr, &from->sin6_addr, dst);
 402                 /* TODO: send reply msg */
 403                 break;
 404         case ICMP6_ROUTER_RENUMBERING_RESULT:
 405                 /* RESULT will be processed by rrenumd */
 406                 break;
 407         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 408                 /* TODO: sequence number reset */
 409                 break;
 410         default:
 411                 syslog(LOG_ERR, "<%s> received unknown code %d",
 412                        __FUNCTION__, rr->rr_code);
 413                 break;
 414
 415         }
 416
 417         return;
 418 }