ifconfig.tproj/af_inet6.c

   1 /*
   2  * Copyright (c) 2009 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30  * Copyright (c) 1983, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58 #ifndef lint
  59 static const char rcsid[] =
  60   "$FreeBSD: src/sbin/ifconfig/af_inet6.c,v 1.6.6.1 2008/11/25 02:59:29 kensmith Exp $";
  61 #endif /* not lint */
  62
  63 #include <sys/param.h>
  64 #include <sys/ioctl.h>
  65 #include <sys/socket.h>
  66 #include <net/if.h>
  67
  68 #include <err.h>
  69 #include <stdio.h>
  70 #include <stdlib.h>
  71 #include <string.h>
  72 #include <unistd.h>
  73 #include <ifaddrs.h>
  74
  75 #include <arpa/inet.h>
  76
  77 #include <netinet/in.h>
  78 #include <net/if_var.h>         /* for struct ifaddr */
  79 #include <netinet/in_var.h>
  80 #include <arpa/inet.h>
  81 #include <netdb.h>
  82
  83 #include <netinet6/nd6.h>       /* Define ND6_INFINITE_LIFETIME */
  84
  85 #include "ifconfig.h"
  86
  87 static  struct in6_ifreq in6_ridreq;
  88 static  struct in6_aliasreq in6_addreq =
  89   { { 0 },
  90     { 0 },
  91     { 0 },
  92     { 0 },
  93     0,
  94     { 0, 0, ND6_INFINITE_LIFETIME, ND6_INFINITE_LIFETIME } };
  95 static  int ip6lifetime;
  96
  97 static  void in6_fillscopeid(struct sockaddr_in6 *sin6);
  98 static  int prefix(void *, int);
  99 static  char *sec2str(time_t);
 100 static  int explicit_prefix = 0;
 101
 102 static  char addr_buf[MAXHOSTNAMELEN *2 + 1];   /*for getnameinfo()*/
 103
 104 static void
 105 setifprefixlen(const char *addr, int dummy __unused, int s,
 106     const struct afswtch *afp)
 107 {
 108         if (afp->af_getprefix != NULL)
 109                 afp->af_getprefix(addr, MASK);
 110         explicit_prefix = 1;
 111 }
 112
 113 static void
 114 setip6flags(const char *dummyaddr __unused, int flag, int dummysoc __unused,
 115     const struct afswtch *afp)
 116 {
 117         if (afp->af_af != AF_INET6)
 118                 err(1, "address flags can be set only for inet6 addresses");
 119
 120         if (flag < 0)
 121                 in6_addreq.ifra_flags &= ~(-flag);
 122         else
 123                 in6_addreq.ifra_flags |= flag;
 124 }
 125
 126 static void
 127 setip6lifetime(const char *cmd, const char *val, int s,
 128     const struct afswtch *afp)
 129 {
 130         time_t newval, t;
 131         char *ep;
 132
 133         t = time(NULL);
 134         newval = (time_t)strtoul(val, &ep, 0);
 135         if (val == ep)
 136                 errx(1, "invalid %s", cmd);
 137         if (afp->af_af != AF_INET6)
 138                 errx(1, "%s not allowed for the AF", cmd);
 139         if (strcmp(cmd, "vltime") == 0) {
 140                 in6_addreq.ifra_lifetime.ia6t_expire = t + newval;
 141                 in6_addreq.ifra_lifetime.ia6t_vltime = newval;
 142         } else if (strcmp(cmd, "pltime") == 0) {
 143                 in6_addreq.ifra_lifetime.ia6t_preferred = t + newval;
 144                 in6_addreq.ifra_lifetime.ia6t_pltime = newval;
 145         }
 146 }
 147
 148 static void
 149 setip6pltime(const char *seconds, int dummy __unused, int s,
 150     const struct afswtch *afp)
 151 {
 152         setip6lifetime("pltime", seconds, s, afp);
 153 }
 154
 155 static void
 156 setip6vltime(const char *seconds, int dummy __unused, int s,
 157     const struct afswtch *afp)
 158 {
 159         setip6lifetime("vltime", seconds, s, afp);
 160 }
 161
 162 static void
 163 setip6eui64(const char *cmd, int dummy __unused, int s,
 164     const struct afswtch *afp)
 165 {
 166         struct ifaddrs *ifap, *ifa;
 167         const struct sockaddr_in6 *sin6 = NULL;
 168         const struct in6_addr *lladdr = NULL;
 169         struct in6_addr *in6;
 170
 171         if (afp->af_af != AF_INET6)
 172                 errx(EXIT_FAILURE, "%s not allowed for the AF", cmd);
 173         in6 = (struct in6_addr *)&in6_addreq.ifra_addr.sin6_addr;
 174         if (memcmp(&in6addr_any.s6_addr[8], &in6->s6_addr[8], 8) != 0)
 175                 errx(EXIT_FAILURE, "interface index is already filled");
 176         if (getifaddrs(&ifap) != 0)
 177                 err(EXIT_FAILURE, "getifaddrs");
 178         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 179                 if (ifa->ifa_addr->sa_family == AF_INET6 &&
 180                     strcmp(ifa->ifa_name, name) == 0) {
 181                         sin6 = (const struct sockaddr_in6 *)ifa->ifa_addr;
 182                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 183                                 lladdr = &sin6->sin6_addr;
 184                                 break;
 185                         }
 186                 }
 187         }
 188         if (!lladdr)
 189                 errx(EXIT_FAILURE, "could not determine link local address");
 190
 191         memcpy(&in6->s6_addr[8], &lladdr->s6_addr[8], 8);
 192
 193         freeifaddrs(ifap);
 194 }
 195
 196 static void
 197 in6_fillscopeid(struct sockaddr_in6 *sin6)
 198 {
 199 #if defined(__KAME__) && defined(KAME_SCOPEID)
 200         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 201                 sin6->sin6_scope_id =
 202                         ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]);
 203                 sin6->sin6_addr.s6_addr[2] = sin6->sin6_addr.s6_addr[3] = 0;
 204         }
 205 #endif
 206 }
 207
 208 static void
 209 in6_status(int s __unused, const struct ifaddrs *ifa)
 210 {
 211         struct sockaddr_in6 *sin, null_sin;
 212         struct in6_ifreq ifr6;
 213         int s6;
 214         u_int32_t flags6;
 215         struct in6_addrlifetime lifetime;
 216         time_t t = time(NULL);
 217         int error;
 218         u_int32_t scopeid;
 219
 220         memset(&null_sin, 0, sizeof(null_sin));
 221
 222         sin = (struct sockaddr_in6 *)ifa->ifa_addr;
 223         if (sin == NULL)
 224                 return;
 225
 226         strncpy(ifr6.ifr_name, ifr.ifr_name, sizeof(ifr.ifr_name));
 227         if ((s6 = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 228                 warn("socket(AF_INET6,SOCK_DGRAM)");
 229                 return;
 230         }
 231         ifr6.ifr_addr = *sin;
 232         if (ioctl(s6, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
 233                 warn("ioctl(SIOCGIFAFLAG_IN6)");
 234                 close(s6);
 235                 return;
 236         }
 237         flags6 = ifr6.ifr_ifru.ifru_flags6;
 238         memset(&lifetime, 0, sizeof(lifetime));
 239         ifr6.ifr_addr = *sin;
 240         if (ioctl(s6, SIOCGIFALIFETIME_IN6, &ifr6) < 0) {
 241                 warn("ioctl(SIOCGIFALIFETIME_IN6)");
 242                 close(s6);
 243                 return;
 244         }
 245         lifetime = ifr6.ifr_ifru.ifru_lifetime;
 246         close(s6);
 247
 248         /* XXX: embedded link local addr check */
 249         if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr) &&
 250             *(u_short *)&sin->sin6_addr.s6_addr[2] != 0) {
 251                 u_short index;
 252
 253                 index = *(u_short *)&sin->sin6_addr.s6_addr[2];
 254                 *(u_short *)&sin->sin6_addr.s6_addr[2] = 0;
 255                 if (sin->sin6_scope_id == 0)
 256                         sin->sin6_scope_id = ntohs(index);
 257         }
 258         scopeid = sin->sin6_scope_id;
 259
 260         error = getnameinfo((struct sockaddr *)sin, sin->sin6_len, addr_buf,
 261                             sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
 262         if (error != 0)
 263                 inet_ntop(AF_INET6, &sin->sin6_addr, addr_buf,
 264                           sizeof(addr_buf));
 265         printf("\tinet6 %s ", addr_buf);
 266
 267         if (ifa->ifa_flags & IFF_POINTOPOINT) {
 268                 sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr;
 269                 /*
 270                  * some of the interfaces do not have valid destination
 271                  * address.
 272                  */
 273                 if (sin != NULL && sin->sin6_family == AF_INET6) {
 274                         int error;
 275
 276                         /* XXX: embedded link local addr check */
 277                         if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr) &&
 278                             *(u_short *)&sin->sin6_addr.s6_addr[2] != 0) {
 279                                 u_short index;
 280
 281                                 index = *(u_short *)&sin->sin6_addr.s6_addr[2];
 282                                 *(u_short *)&sin->sin6_addr.s6_addr[2] = 0;
 283                                 if (sin->sin6_scope_id == 0)
 284                                         sin->sin6_scope_id = ntohs(index);
 285                         }
 286
 287                         error = getnameinfo((struct sockaddr *)sin,
 288                                             sin->sin6_len, addr_buf,
 289                                             sizeof(addr_buf), NULL, 0,
 290                                             NI_NUMERICHOST);
 291                         if (error != 0)
 292                                 inet_ntop(AF_INET6, &sin->sin6_addr, addr_buf,
 293                                           sizeof(addr_buf));
 294                         printf("--> %s ", addr_buf);
 295                 }
 296         }
 297
 298         sin = (struct sockaddr_in6 *)ifa->ifa_netmask;
 299         if (sin == NULL)
 300                 sin = &null_sin;
 301         printf("prefixlen %d ", prefix(&sin->sin6_addr,
 302                 sizeof(struct in6_addr)));
 303
 304         if ((flags6 & IN6_IFF_ANYCAST) != 0)
 305                 printf("anycast ");
 306         if ((flags6 & IN6_IFF_TENTATIVE) != 0)
 307                 printf("tentative ");
 308         if ((flags6 & IN6_IFF_DUPLICATED) != 0)
 309                 printf("duplicated ");
 310         if ((flags6 & IN6_IFF_DETACHED) != 0)
 311                 printf("detached ");
 312         if ((flags6 & IN6_IFF_DEPRECATED) != 0)
 313                 printf("deprecated ");
 314         if ((flags6 & IN6_IFF_AUTOCONF) != 0)
 315                 printf("autoconf ");
 316         if ((flags6 & IN6_IFF_TEMPORARY) != 0)
 317                 printf("temporary ");
 318
 319         if (scopeid)
 320                 printf("scopeid 0x%x ", scopeid);
 321
 322         if (ip6lifetime && (lifetime.ia6t_preferred || lifetime.ia6t_expire)) {
 323                 printf("pltime ");
 324                 if (lifetime.ia6t_preferred) {
 325                         printf("%s ", lifetime.ia6t_preferred < t
 326                                 ? "0" : sec2str(lifetime.ia6t_preferred - t));
 327                 } else
 328                         printf("infty ");
 329
 330                 printf("vltime ");
 331                 if (lifetime.ia6t_expire) {
 332                         printf("%s ", lifetime.ia6t_expire < t
 333                                 ? "0" : sec2str(lifetime.ia6t_expire - t));
 334                 } else
 335                         printf("infty ");
 336         }
 337
 338         putchar('\n');
 339 }
 340
 341 #define SIN6(x) ((struct sockaddr_in6 *) &(x))
 342 static struct   sockaddr_in6 *sin6tab[] = {
 343         SIN6(in6_ridreq.ifr_addr), SIN6(in6_addreq.ifra_addr),
 344         SIN6(in6_addreq.ifra_prefixmask), SIN6(in6_addreq.ifra_dstaddr)
 345 };
 346
 347 static void
 348 in6_getprefix(const char *plen, int which)
 349 {
 350         struct sockaddr_in6 *sin = sin6tab[which];
 351         u_char *cp;
 352         int len = atoi(plen);
 353
 354         if ((len < 0) || (len > 128))
 355                 errx(1, "%s: bad value", plen);
 356         sin->sin6_len = sizeof(*sin);
 357         if (which != MASK)
 358                 sin->sin6_family = AF_INET6;
 359         if ((len == 0) || (len == 128)) {
 360                 memset(&sin->sin6_addr, 0xff, sizeof(struct in6_addr));
 361                 return;
 362         }
 363         memset((void *)&sin->sin6_addr, 0x00, sizeof(sin->sin6_addr));
 364         for (cp = (u_char *)&sin->sin6_addr; len > 7; len -= 8)
 365                 *cp++ = 0xff;
 366         *cp = 0xff << (8 - len);
 367 }
 368
 369 static void
 370 in6_getaddr(const char *s, int which)
 371 {
 372         struct sockaddr_in6 *sin = sin6tab[which];
 373         struct addrinfo hints, *res;
 374         int error = -1;
 375
 376         newaddr &= 1;
 377
 378         sin->sin6_len = sizeof(*sin);
 379         if (which != MASK)
 380                 sin->sin6_family = AF_INET6;
 381
 382         if (which == ADDR) {
 383                 char *p = NULL;
 384                 if((p = strrchr(s, '/')) != NULL) {
 385                         *p = '\0';
 386                         in6_getprefix(p + 1, MASK);
 387                         explicit_prefix = 1;
 388                 }
 389         }
 390
 391         if (sin->sin6_family == AF_INET6) {
 392                 bzero(&hints, sizeof(struct addrinfo));
 393                 hints.ai_family = AF_INET6;
 394                 error = getaddrinfo(s, NULL, &hints, &res);
 395         }
 396         if (error != 0) {
 397                 if (inet_pton(AF_INET6, s, &sin->sin6_addr) != 1)
 398                         errx(1, "%s: bad value", s);
 399         } else
 400                 bcopy(res->ai_addr, sin, res->ai_addrlen);
 401 }
 402
 403 static int
 404 prefix(void *val, int size)
 405 {
 406         u_char *name = (u_char *)val;
 407         int byte, bit, plen = 0;
 408
 409         for (byte = 0; byte < size; byte++, plen += 8)
 410                 if (name[byte] != 0xff)
 411                         break;
 412         if (byte == size)
 413                 return (plen);
 414         for (bit = 7; bit != 0; bit--, plen++)
 415                 if (!(name[byte] & (1 << bit)))
 416                         break;
 417         for (; bit != 0; bit--)
 418                 if (name[byte] & (1 << bit))
 419                         return(0);
 420         byte++;
 421         for (; byte < size; byte++)
 422                 if (name[byte])
 423                         return(0);
 424         return (plen);
 425 }
 426
 427 static char *
 428 sec2str(time_t total)
 429 {
 430         static char result[256];
 431         int days, hours, mins, secs;
 432         int first = 1;
 433         char *p = result;
 434
 435         if (0) {
 436                 days = total / 3600 / 24;
 437                 hours = (total / 3600) % 24;
 438                 mins = (total / 60) % 60;
 439                 secs = total % 60;
 440
 441                 if (days) {
 442                         first = 0;
 443                         p += snprintf(p, sizeof(result) - (p - result), "%dd", days);
 444                 }
 445                 if (!first || hours) {
 446                         first = 0;
 447                         p += snprintf(p, sizeof(result) - (p - result), "%dh", hours);
 448                 }
 449                 if (!first || mins) {
 450                         first = 0;
 451                         p += snprintf(p, sizeof(result) - (p - result), "%dm", mins);
 452                 }
 453                 snprintf(p, sizeof(result) - (p - result), "%ds", secs);
 454         } else
 455                 snprintf(result, sizeof(result), "%lu", (unsigned long)total);
 456
 457         return(result);
 458 }
 459
 460 static void
 461 in6_postproc(int s, const struct afswtch *afp)
 462 {
 463         if (explicit_prefix == 0) {
 464                 /* Aggregatable address architecture defines all prefixes
 465                    are 64. So, it is convenient to set prefixlen to 64 if
 466                    it is not specified. */
 467                 setifprefixlen("64", 0, s, afp);
 468                 /* in6_getprefix("64", MASK) if MASK is available here... */
 469         }
 470 }
 471
 472 static void
 473 in6_status_tunnel(int s)
 474 {
 475         char src[NI_MAXHOST];
 476         char dst[NI_MAXHOST];
 477         struct in6_ifreq in6_ifr;
 478         const struct sockaddr *sa = (const struct sockaddr *) &in6_ifr.ifr_addr;
 479
 480         memset(&in6_ifr, 0, sizeof(in6_ifr));
 481         strncpy(in6_ifr.ifr_name, name, IFNAMSIZ);
 482
 483         if (ioctl(s, SIOCGIFPSRCADDR_IN6, (caddr_t)&in6_ifr) < 0)
 484                 return;
 485         if (sa->sa_family != AF_INET6)
 486                 return;
 487         in6_fillscopeid(&in6_ifr.ifr_addr);
 488         if (getnameinfo(sa, sa->sa_len, src, sizeof(src), 0, 0,
 489             NI_NUMERICHOST) != 0)
 490                 src[0] = '\0';
 491
 492         if (ioctl(s, SIOCGIFPDSTADDR_IN6, (caddr_t)&in6_ifr) < 0)
 493                 return;
 494         if (sa->sa_family != AF_INET6)
 495                 return;
 496         in6_fillscopeid(&in6_ifr.ifr_addr);
 497         if (getnameinfo(sa, sa->sa_len, dst, sizeof(dst), 0, 0,
 498             NI_NUMERICHOST) != 0)
 499                 dst[0] = '\0';
 500
 501         printf("\ttunnel inet6 %s --> %s\n", src, dst);
 502 }
 503
 504 static void
 505 in6_set_tunnel(int s, struct addrinfo *srcres, struct addrinfo *dstres)
 506 {
 507         struct in6_aliasreq in6_addreq;
 508
 509         memset(&in6_addreq, 0, sizeof(in6_addreq));
 510         strncpy(in6_addreq.ifra_name, name, IFNAMSIZ);
 511         memcpy(&in6_addreq.ifra_addr, srcres->ai_addr, srcres->ai_addr->sa_len);
 512         memcpy(&in6_addreq.ifra_dstaddr, dstres->ai_addr,
 513             dstres->ai_addr->sa_len);
 514
 515         if (ioctl(s, SIOCSIFPHYADDR_IN6, &in6_addreq) < 0)
 516                 warn("SIOCSIFPHYADDR_IN6");
 517 }
 518
 519 static struct cmd inet6_cmds[] = {
 520         DEF_CMD_ARG("prefixlen",                        setifprefixlen),
 521         DEF_CMD("anycast",      IN6_IFF_ANYCAST,        setip6flags),
 522         DEF_CMD("tentative",    IN6_IFF_TENTATIVE,      setip6flags),
 523         DEF_CMD("-tentative",   -IN6_IFF_TENTATIVE,     setip6flags),
 524         DEF_CMD("deprecated",   IN6_IFF_DEPRECATED,     setip6flags),
 525         DEF_CMD("-deprecated", -IN6_IFF_DEPRECATED,     setip6flags),
 526         DEF_CMD("autoconf",     IN6_IFF_AUTOCONF,       setip6flags),
 527         DEF_CMD("-autoconf",    -IN6_IFF_AUTOCONF,      setip6flags),
 528         DEF_CMD_ARG("pltime",                           setip6pltime),
 529         DEF_CMD_ARG("vltime",                           setip6vltime),
 530         DEF_CMD("eui64",        0,                      setip6eui64),
 531 };
 532
 533 static struct afswtch af_inet6 = {
 534         .af_name        = "inet6",
 535         .af_af          = AF_INET6,
 536         .af_status      = in6_status,
 537         .af_getaddr     = in6_getaddr,
 538         .af_getprefix   = in6_getprefix,
 539         .af_postproc    = in6_postproc,
 540         .af_status_tunnel = in6_status_tunnel,
 541         .af_settunnel   = in6_set_tunnel,
 542         .af_difaddr     = SIOCDIFADDR_IN6,
 543         .af_aifaddr     = SIOCAIFADDR_IN6,
 544         .af_ridreq      = &in6_addreq,
 545         .af_addreq      = &in6_addreq,
 546 };
 547
 548 static void
 549 in6_Lopt_cb(const char *optarg __unused)
 550 {
 551         ip6lifetime++;  /* print IPv6 address lifetime */
 552 }
 553 static struct option in6_Lopt = { "L", "[-L]", in6_Lopt_cb };
 554
 555 static __constructor void
 556 inet6_ctor(void)
 557 {
 558 #define N(a)    (sizeof(a) / sizeof(a[0]))
 559         int i;
 560
 561         for (i = 0; i < N(inet6_cmds);  i++)
 562                 cmd_register(&inet6_cmds[i]);
 563         af_register(&af_inet6);
 564         opt_register(&in6_Lopt);
 565 #undef N
 566 }