sbin/ifconfig/ifmedia.c

   1 /*      $NetBSD: ifconfig.c,v 1.34 1997/04/21 01:17:58 lukem Exp $      */
   2 /* $FreeBSD: src/sbin/ifconfig/ifmedia.c,v 1.6.2.3 2001/11/14 04:35:07 yar Exp $ */
   3
   4 /*
   5  * Copyright (c) 1997 Jason R. Thorpe.
   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. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed for the NetBSD Project
  19  *      by Jason R. Thorpe.
  20  * 4. The name of the author may not be used to endorse or promote products
  21  *    derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 /*
  37  * Copyright (c) 1983, 1993
  38  *      The Regents of the University of California.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. All advertising materials mentioning features or use of this software
  49  *    must display the following acknowledgement:
  50  *      This product includes software developed by the University of
  51  *      California, Berkeley and its contributors.
  52  * 4. Neither the name of the University nor the names of its contributors
  53  *    may be used to endorse or promote products derived from this software
  54  *    without specific prior written permission.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  */
  68
  69 #include <sys/param.h>
  70 #include <sys/ioctl.h>
  71 #include <sys/socket.h>
  72 #include <sys/sysctl.h>
  73 #include <sys/time.h>
  74
  75 #include <net/if.h>
  76 #include <net/if_dl.h>
  77 #include <net/if_types.h>
  78 #include <net/if_media.h>
  79 #include <net/route.h>
  80
  81 #include <ctype.h>
  82 #include <err.h>
  83 #include <errno.h>
  84 #include <fcntl.h>
  85 #include <stdio.h>
  86 #include <stdlib.h>
  87 #include <string.h>
  88 #include <unistd.h>
  89
  90 #include "ifconfig.h"
  91
  92 static void     domediaopt __P((const char *, int, int));
  93 static int      get_media_subtype __P((int, const char *));
  94 static int      get_media_options __P((int, const char *));
  95 static int      lookup_media_word __P((struct ifmedia_description *, const char *));
  96 static void     print_media_word __P((int, int));
  97 static void     print_media_word_ifconfig __P((int));
  98
  99 static struct ifmedia_description *get_toptype_desc __P((int));
 100 static struct ifmedia_type_to_subtype *get_toptype_ttos __P((int));
 101 static struct ifmedia_description *get_subtype_desc __P((int,
 102     struct ifmedia_type_to_subtype *ttos));
 103
 104 void
 105 media_status(s, info)
 106         int s;
 107         struct rt_addrinfo *info __unused;
 108 {
 109         struct ifmediareq ifmr;
 110         int *media_list, i;
 111
 112         (void) memset(&ifmr, 0, sizeof(ifmr));
 113         (void) strncpy(ifmr.ifm_name, name, sizeof(ifmr.ifm_name));
 114
 115         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
 116                 /*
 117                  * Interface doesn't support SIOC{G,S}IFMEDIA.
 118                  */
 119                 return;
 120         }
 121
 122         if (ifmr.ifm_count == 0) {
 123                 warnx("%s: no media types?", name);
 124                 return;
 125         }
 126
 127         media_list = (int *)malloc(ifmr.ifm_count * sizeof(int));
 128         if (media_list == NULL)
 129                 err(1, "malloc");
 130         ifmr.ifm_ulist = media_list;
 131
 132         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
 133                 err(1, "SIOCGIFMEDIA");
 134
 135         printf("\tmedia: ");
 136         print_media_word(ifmr.ifm_current, 1);
 137         if (ifmr.ifm_active != ifmr.ifm_current) {
 138                 putchar(' ');
 139                 putchar('(');
 140                 print_media_word(ifmr.ifm_active, 0);
 141                 putchar(')');
 142         }
 143
 144         putchar('\n');
 145
 146         if (ifmr.ifm_status & IFM_AVALID) {
 147                 printf("\tstatus: ");
 148                 switch (IFM_TYPE(ifmr.ifm_active)) {
 149                 case IFM_ETHER:
 150                         if (ifmr.ifm_status & IFM_ACTIVE)
 151                                 printf("active");
 152                         else
 153                                 printf("no carrier");
 154                         break;
 155
 156                 case IFM_FDDI:
 157                 case IFM_TOKEN:
 158                         if (ifmr.ifm_status & IFM_ACTIVE)
 159                                 printf("inserted");
 160                         else
 161                                 printf("no ring");
 162                         break;
 163                 case IFM_IEEE80211:
 164                         /* XXX: Different value for adhoc? */
 165                         if (ifmr.ifm_status & IFM_ACTIVE)
 166                                 printf("associated");
 167                         else
 168                                 printf("no carrier");
 169                         break;
 170                 }
 171                 putchar('\n');
 172         }
 173
 174         if (ifmr.ifm_count > 0 && supmedia) {
 175                 printf("\tsupported media:\n");
 176                 for (i = 0; i < ifmr.ifm_count; i++) {
 177                         printf("\t\t");
 178                         print_media_word_ifconfig(media_list[i]);
 179                         putchar('\n');
 180                 }
 181         }
 182
 183         free(media_list);
 184 }
 185
 186 void
 187 setmedia(val, d, s, afp)
 188         const char *val;
 189         int d;
 190         int s;
 191         const struct afswtch *afp;
 192 {
 193         struct ifmediareq ifmr;
 194         int first_type, subtype;
 195
 196         (void) memset(&ifmr, 0, sizeof(ifmr));
 197         (void) strncpy(ifmr.ifm_name, name, sizeof(ifmr.ifm_name));
 198
 199         ifmr.ifm_count = 1;
 200         ifmr.ifm_ulist = &first_type;
 201         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
 202                 /*
 203                  * If we get E2BIG, the kernel is telling us
 204                  * that there are more, so we can ignore it.
 205                  */
 206                 if (errno != E2BIG)
 207                         err(1, "SIOCGIFMEDIA");
 208         }
 209
 210         if (ifmr.ifm_count == 0)
 211                 errx(1, "%s: no media types?", name);
 212
 213         /*
 214          * We are primarily concerned with the top-level type.
 215          * However, "current" may be only IFM_NONE, so we just look
 216          * for the top-level type in the first "supported type"
 217          * entry.
 218          *
 219          * (I'm assuming that all supported media types for a given
 220          * interface will be the same top-level type..)
 221          */
 222         subtype = get_media_subtype(IFM_TYPE(first_type), val);
 223
 224         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
 225         ifr.ifr_media = (ifmr.ifm_current & ~(IFM_NMASK|IFM_TMASK)) |
 226             IFM_TYPE(first_type) | subtype;
 227
 228         if (ioctl(s, SIOCSIFMEDIA, (caddr_t)&ifr) < 0)
 229                 err(1, "SIOCSIFMEDIA");
 230 }
 231
 232 void
 233 setmediaopt(val, d, s, afp)
 234         const char *val;
 235         int d;
 236         int s;
 237         const struct afswtch *afp;
 238 {
 239
 240         domediaopt(val, 0, s);
 241 }
 242
 243 void
 244 unsetmediaopt(val, d, s, afp)
 245         const char *val;
 246         int d;
 247         int s;
 248         const struct afswtch *afp;
 249 {
 250
 251         domediaopt(val, 1, s);
 252 }
 253
 254 static void
 255 domediaopt(val, clear, s)
 256         const char *val;
 257         int clear;
 258         int s;
 259 {
 260         struct ifmediareq ifmr;
 261         int *mwords, options;
 262
 263         (void) memset(&ifmr, 0, sizeof(ifmr));
 264         (void) strncpy(ifmr.ifm_name, name, sizeof(ifmr.ifm_name));
 265
 266         /*
 267          * We must go through the motions of reading all
 268          * supported media because we need to know both
 269          * the current media type and the top-level type.
 270          */
 271
 272         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
 273                 err(1, "SIOCGIFMEDIA");
 274
 275         if (ifmr.ifm_count == 0)
 276                 errx(1, "%s: no media types?", name);
 277
 278         mwords = (int *)malloc(ifmr.ifm_count * sizeof(int));
 279         if (mwords == NULL)
 280                 err(1, "malloc");
 281
 282         ifmr.ifm_ulist = mwords;
 283         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
 284                 err(1, "SIOCGIFMEDIA");
 285
 286         options = get_media_options(IFM_TYPE(mwords[0]), val);
 287
 288         free(mwords);
 289
 290         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
 291         ifr.ifr_media = ifmr.ifm_current;
 292         if (clear)
 293                 ifr.ifr_media &= ~options;
 294         else
 295                 ifr.ifr_media |= options;
 296
 297         if (ioctl(s, SIOCSIFMEDIA, (caddr_t)&ifr) < 0)
 298                 err(1, "SIOCSIFMEDIA");
 299 }
 300
 301 /**********************************************************************
 302  * A good chunk of this is duplicated from sys/net/ifmedia.c
 303  **********************************************************************/
 304
 305 static struct ifmedia_description ifm_type_descriptions[] =
 306     IFM_TYPE_DESCRIPTIONS;
 307
 308 static struct ifmedia_description ifm_subtype_ethernet_descriptions[] =
 309     IFM_SUBTYPE_ETHERNET_DESCRIPTIONS;
 310
 311 static struct ifmedia_description ifm_subtype_ethernet_aliases[] =
 312     IFM_SUBTYPE_ETHERNET_ALIASES;
 313
 314 static struct ifmedia_description ifm_subtype_ethernet_option_descriptions[] =
 315     IFM_SUBTYPE_ETHERNET_OPTION_DESCRIPTIONS;
 316
 317 static struct ifmedia_description ifm_subtype_tokenring_descriptions[] =
 318     IFM_SUBTYPE_TOKENRING_DESCRIPTIONS;
 319
 320 static struct ifmedia_description ifm_subtype_tokenring_aliases[] =
 321     IFM_SUBTYPE_TOKENRING_ALIASES;
 322
 323 static struct ifmedia_description ifm_subtype_tokenring_option_descriptions[] =
 324     IFM_SUBTYPE_TOKENRING_OPTION_DESCRIPTIONS;
 325
 326 static struct ifmedia_description ifm_subtype_fddi_descriptions[] =
 327     IFM_SUBTYPE_FDDI_DESCRIPTIONS;
 328
 329 static struct ifmedia_description ifm_subtype_fddi_aliases[] =
 330     IFM_SUBTYPE_FDDI_ALIASES;
 331
 332 static struct ifmedia_description ifm_subtype_fddi_option_descriptions[] =
 333     IFM_SUBTYPE_FDDI_OPTION_DESCRIPTIONS;
 334
 335 static struct ifmedia_description ifm_subtype_ieee80211_descriptions[] =
 336     IFM_SUBTYPE_IEEE80211_DESCRIPTIONS;
 337
 338 static struct ifmedia_description ifm_subtype_ieee80211_aliases[] =
 339     IFM_SUBTYPE_IEEE80211_ALIASES;
 340
 341 static struct ifmedia_description ifm_subtype_ieee80211_option_descriptions[] =
 342     IFM_SUBTYPE_IEEE80211_OPTION_DESCRIPTIONS;
 343
 344 static struct ifmedia_description ifm_subtype_shared_descriptions[] =
 345     IFM_SUBTYPE_SHARED_DESCRIPTIONS;
 346
 347 static struct ifmedia_description ifm_subtype_shared_aliases[] =
 348     IFM_SUBTYPE_SHARED_ALIASES;
 349
 350 static struct ifmedia_description ifm_shared_option_descriptions[] =
 351     IFM_SHARED_OPTION_DESCRIPTIONS;
 352
 353 struct ifmedia_type_to_subtype {
 354         struct {
 355                 struct ifmedia_description *desc;
 356                 int alias;
 357         } subtypes[5];
 358         struct {
 359                 struct ifmedia_description *desc;
 360                 int alias;
 361         } options[3];
 362 };
 363
 364 /* must be in the same order as IFM_TYPE_DESCRIPTIONS */
 365 static struct ifmedia_type_to_subtype ifmedia_types_to_subtypes[] = {
 366         {
 367                 {
 368                         { &ifm_subtype_shared_descriptions[0], 0 },
 369                         { &ifm_subtype_shared_aliases[0], 1 },
 370                         { &ifm_subtype_ethernet_descriptions[0], 0 },
 371                         { &ifm_subtype_ethernet_aliases[0], 1 },
 372                         { NULL, 0 },
 373                 },
 374                 {
 375                         { &ifm_shared_option_descriptions[0], 0 },
 376                         { &ifm_subtype_ethernet_option_descriptions[0], 0 },
 377                         { NULL, 0 },
 378                 },
 379         },
 380         {
 381                 {
 382                         { &ifm_subtype_shared_descriptions[0], 0 },
 383                         { &ifm_subtype_shared_aliases[0], 1 },
 384                         { &ifm_subtype_tokenring_descriptions[0], 0 },
 385                         { &ifm_subtype_tokenring_aliases[0], 1 },
 386                         { NULL, 0 },
 387                 },
 388                 {
 389                         { &ifm_shared_option_descriptions[0], 0 },
 390                         { &ifm_subtype_tokenring_option_descriptions[0], 0 },
 391                         { NULL, 0 },
 392                 },
 393         },
 394         {
 395                 {
 396                         { &ifm_subtype_shared_descriptions[0], 0 },
 397                         { &ifm_subtype_shared_aliases[0], 1 },
 398                         { &ifm_subtype_fddi_descriptions[0], 0 },
 399                         { &ifm_subtype_fddi_aliases[0], 1 },
 400                         { NULL, 0 },
 401                 },
 402                 {
 403                         { &ifm_shared_option_descriptions[0], 0 },
 404                         { &ifm_subtype_fddi_option_descriptions[0], 0 },
 405                         { NULL, 0 },
 406                 },
 407         },
 408         {
 409                 {
 410                         { &ifm_subtype_shared_descriptions[0], 0 },
 411                         { &ifm_subtype_shared_aliases[0], 1 },
 412                         { &ifm_subtype_ieee80211_descriptions[0], 0 },
 413                         { &ifm_subtype_ieee80211_aliases[0], 1 },
 414                         { NULL, 0 },
 415                 },
 416                 {
 417                         { &ifm_shared_option_descriptions[0], 0 },
 418                         { &ifm_subtype_ieee80211_option_descriptions[0], 0 },
 419                         { NULL, 0 },
 420                 },
 421         },
 422 };
 423
 424 static int
 425 get_media_subtype(type, val)
 426         int type;
 427         const char *val;
 428 {
 429         struct ifmedia_description *desc;
 430         struct ifmedia_type_to_subtype *ttos;
 431         int rval, i;
 432
 433         /* Find the top-level interface type. */
 434         for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
 435             desc->ifmt_string != NULL; desc++, ttos++)
 436                 if (type == desc->ifmt_word)
 437                         break;
 438         if (desc->ifmt_string == NULL)
 439                 errx(1, "unknown media type 0x%x", type);
 440
 441         for (i = 0; ttos->subtypes[i].desc != NULL; i++) {
 442                 rval = lookup_media_word(ttos->subtypes[i].desc, val);
 443                 if (rval != -1)
 444                         return (rval);
 445         }
 446         errx(1, "unknown media subtype: %s", val);
 447         /* NOTREACHED */
 448 }
 449
 450 static int
 451 get_media_options(type, val)
 452         int type;
 453         const char *val;
 454 {
 455         struct ifmedia_description *desc;
 456         struct ifmedia_type_to_subtype *ttos;
 457         char *optlist, *optptr;
 458         int option = 0, i, rval = 0;
 459
 460         /* We muck with the string, so copy it. */
 461         optlist = strdup(val);
 462         if (optlist == NULL)
 463                 err(1, "strdup");
 464
 465         /* Find the top-level interface type. */
 466         for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
 467             desc->ifmt_string != NULL; desc++, ttos++)
 468                 if (type == desc->ifmt_word)
 469                         break;
 470         if (desc->ifmt_string == NULL)
 471                 errx(1, "unknown media type 0x%x", type);
 472
 473         /*
 474          * Look up the options in the user-provided comma-separated
 475          * list.
 476          */
 477         optptr = optlist;
 478         for (; (optptr = strtok(optptr, ",")) != NULL; optptr = NULL) {
 479                 for (i = 0; ttos->options[i].desc != NULL; i++) {
 480                         option = lookup_media_word(ttos->options[i].desc, optptr);
 481                         if (option != -1)
 482                                 break;
 483                 }
 484                 if (option == 0)
 485                         errx(1, "unknown option: %s", optptr);
 486                 rval |= option;
 487         }
 488
 489         free(optlist);
 490         return (rval);
 491 }
 492
 493 static int
 494 lookup_media_word(desc, val)
 495         struct ifmedia_description *desc;
 496         const char *val;
 497 {
 498
 499         for (; desc->ifmt_string != NULL; desc++)
 500                 if (strcasecmp(desc->ifmt_string, val) == 0)
 501                         return (desc->ifmt_word);
 502
 503         return (-1);
 504 }
 505
 506 static struct ifmedia_description *get_toptype_desc(ifmw)
 507         int ifmw;
 508 {
 509         struct ifmedia_description *desc;
 510
 511         for (desc = ifm_type_descriptions; desc->ifmt_string != NULL; desc++)
 512                 if (IFM_TYPE(ifmw) == desc->ifmt_word)
 513                         break;
 514
 515         return desc;
 516 }
 517
 518 static struct ifmedia_type_to_subtype *get_toptype_ttos(ifmw)
 519         int ifmw;
 520 {
 521         struct ifmedia_description *desc;
 522         struct ifmedia_type_to_subtype *ttos;
 523
 524         for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
 525             desc->ifmt_string != NULL; desc++, ttos++)
 526                 if (IFM_TYPE(ifmw) == desc->ifmt_word)
 527                         break;
 528
 529         return ttos;
 530 }
 531
 532 static struct ifmedia_description *get_subtype_desc(ifmw, ttos)
 533         int ifmw;
 534         struct ifmedia_type_to_subtype *ttos;
 535 {
 536         int i;
 537         struct ifmedia_description *desc;
 538
 539         for (i = 0; ttos->subtypes[i].desc != NULL; i++) {
 540                 if (ttos->subtypes[i].alias)
 541                         continue;
 542                 for (desc = ttos->subtypes[i].desc;
 543                     desc->ifmt_string != NULL; desc++) {
 544                         if (IFM_SUBTYPE(ifmw) == desc->ifmt_word)
 545                                 return desc;
 546                 }
 547         }
 548
 549         return NULL;
 550 }
 551
 552 static void
 553 print_media_word(ifmw, print_toptype)
 554         int ifmw;
 555         int print_toptype;
 556 {
 557         struct ifmedia_description *desc;
 558         struct ifmedia_type_to_subtype *ttos;
 559         int seen_option = 0, i;
 560
 561         /* Find the top-level interface type. */
 562         desc = get_toptype_desc(ifmw);
 563         ttos = get_toptype_ttos(ifmw);
 564         if (desc->ifmt_string == NULL) {
 565                 printf("<unknown type>");
 566                 return;
 567         } else if (print_toptype) {
 568                 printf("%s", desc->ifmt_string);
 569         }
 570
 571         /*
 572          * Don't print the top-level type; it's not like we can
 573          * change it, or anything.
 574          */
 575
 576         /* Find subtype. */
 577         desc = get_subtype_desc(ifmw, ttos);
 578         if (desc != NULL)
 579                 goto got_subtype;
 580
 581         /* Falling to here means unknown subtype. */
 582         printf("<unknown subtype>");
 583         return;
 584
 585  got_subtype:
 586         if (print_toptype)
 587                 putchar(' ');
 588
 589         printf("%s", desc->ifmt_string);
 590
 591         /* Find options. */
 592         for (i = 0; ttos->options[i].desc != NULL; i++) {
 593                 if (ttos->options[i].alias)
 594                         continue;
 595                 for (desc = ttos->options[i].desc;
 596                     desc->ifmt_string != NULL; desc++) {
 597                         if (ifmw & desc->ifmt_word) {
 598                                 if (seen_option == 0)
 599                                         printf(" <");
 600                                 printf("%s%s", seen_option++ ? "," : "",
 601                                     desc->ifmt_string);
 602                         }
 603                 }
 604         }
 605         printf("%s", seen_option ? ">" : "");
 606 }
 607
 608 static void
 609 print_media_word_ifconfig(ifmw)
 610         int ifmw;
 611 {
 612         struct ifmedia_description *desc;
 613         struct ifmedia_type_to_subtype *ttos;
 614         int i;
 615
 616         /* Find the top-level interface type. */
 617         desc = get_toptype_desc(ifmw);
 618         ttos = get_toptype_ttos(ifmw);
 619         if (desc->ifmt_string == NULL) {
 620                 printf("<unknown type>");
 621                 return;
 622         }
 623
 624         /*
 625          * Don't print the top-level type; it's not like we can
 626          * change it, or anything.
 627          */
 628
 629         /* Find subtype. */
 630         desc = get_subtype_desc(ifmw, ttos);
 631         if (desc != NULL)
 632                 goto got_subtype;
 633
 634         /* Falling to here means unknown subtype. */
 635         printf("<unknown subtype>");
 636         return;
 637
 638  got_subtype:
 639         printf("media %s", desc->ifmt_string);
 640
 641         /* Find options. */
 642         for (i = 0; ttos->options[i].desc != NULL; i++) {
 643                 if (ttos->options[i].alias)
 644                         continue;
 645                 for (desc = ttos->options[i].desc;
 646                     desc->ifmt_string != NULL; desc++) {
 647                         if (ifmw & desc->ifmt_word) {
 648                                 printf(" mediaopt %s", desc->ifmt_string);
 649                         }
 650                 }
 651         }
 652 }
 653
 654 /**********************************************************************
 655  * ...until here.
 656  **********************************************************************/